11244	----	A Project for Flying. In Earnest at Last! 1871 Price, TWENTY-FIVE CENTS. A Project for Flying. In Earnest At Last. The following appeared in one of our public journals of the date indicated _To the Editor of the Tribune._ SIR:--You rightly appreciate the interest with which the popular mind regards all efforts in the direction of navigating the air. One man of my acquaintance was deeply interested to know the results of the California Experiment, because he alone, as he believed, had questioned Nature and learned from her the great secret of aerial navigation. To-day's _Tribune_ brings us the full account of the machine, its performance and _modus operandi_; and without the authority of my friend, I can pronounce at once that the thing is simply ridiculous. It is the same old useless effort, with the same impossible agents. But to-day, within twenty miles of Trinity steeple, lives the man who can give to the world the secret of navigating the air, in calm or in storm, with the wind or against it; skimming the earth, or in the highest currents, just as he wills, with all the ease, and all the swiftness, and all the exactitude of a bird. My friend is only waiting for an opportunity to perfect his plan, when he will make it known. Yours truly, W.H.K. _New York; June 14th_, 1869. Two years have passed and no progress has been made in aerial navigation. The California Experiment failed. The great Airship "CITY OF NEW YORK," had previously escaped the same fate, only because more prudent than her successor she declined a trial. The promising and ambitious enterprise of Mr. Henson has hardly been spoken of for a quarter of a century. And notwithstanding the fact that the number of ascensions in balloons in the United States and Europe must be counted by thousands, and although the exigencies of recent wars have made them useful, yet it must be confessed that the art of navigating the air remains in much the same state in which the brothers Montgolfiers left it at the close of the last century. The reason for this want of progress in the art referred to, is not to be sought in any want of interest in the subject, or of enthusiasm in prosecuting experiments. Certainly not for want of interest in the subject because _to fly_, has been the great desideratum of the race since Adam. And we find in the literature of every age suggestions for means of achieving flight through the air, in imitation of birds; or for the construction of ingenious machines for aerial navigation. And if history and traditions are to be credited, it would be equally an error to suppose that our age alone had attempted to put theory into practice in reference to navigating the air. Even the fables of the ancients abound with stories about flying: that of Dedalus and his son Icarius, will occur to every reader. And the representations of the POETS, and the allusions in HOLY WRIT equally prove how natural and dear to the mind of man is the idea of possessing "wings like a dove." But it is safe enough to assert, that hitherto, all attempts at _navigating_ the air have been failures. Floating through the atmosphere in a balloon, at the mercy not only of every _wind_ but of every _breath_ of air, is in no adequate sense aerial navigation. And I do not hesitate to say, that balloons are absolutely incapable of being directed. All the analogies by which inventors have been encouraged in their expectations are false, the rudders of ships and the tails of birds are no exceptions. They will never be able to guide balloons as sailors do ships, by a rudder, because ships do not float suspended in the water as balloons float in the air; nor do birds _float_ through the air in any sense. They are not bouyant--lighter than the element in which they move, but immensely heavier; besides they do not guide themselves wholly by their tails. We may depend upon it, if we ever succeed in navigating the air, it will be by a strict adherence to the principles upon which birds fly, and a close imitation of the means which they employ to effect that object. It is true, that in respect to the means to be employed, animals designed by the Creator for flight, have greatly the advantage of us, but what natural deficiencies will not human ingenuity supply, and what obstacles will not human skill overcome? It has already triumphed over much greater than any that Nature has interposed between man and the pleasures of aerial communication. We have to a great extent, mastered the mysterious elements of nature. We have conquered the thunderbolt and learned to write with the burning fluid out of which it is forged. We have converted the boundless ocean into a vast highway, traversed for our use and on our errands, by the swift agent, and by great ships driven against wind and tide by the mighty power of steam. And yet a single generation ago, we knew nothing of all this, Our grand-sires would have given these achievements a prominent place in the list of impossible things. But, do you say, "the Creator never intended us to fly--_therefore_, it is impossible." For what did the Creator give us skill and boundless perseverance? Was it designed that we should _swim_, more than that we should furnish ourselves with wings and mount up as eagles? "We sink like lead in the mighty waters," we only fall a little faster through the air. Still, I grant that the problem of aerial navigation will only be solved when the principles of flight are clearly understood, and we recognize precisely what are the obstacles which prevent us from flying by artificial means. Will these obstacles prove insuperable? It is at present believed by the multitude that they will, but I entertain a different opinion, most decidedly. From my earliest youth this subject has occupied my thoughts. It has been the study of my life, and I modestly trust that I have not questioned nature and science in vain. In the first place, I undertook to make myself familiar with the obstacles to be overcome. I found the greatest of these to be gravity. I found, however, that heavy fowls, who were unable to rise _from the earth_, and only accomplished flight by taking advantage of an eminence, sustained themselves without difficulty when once fairly embarked. I also found that the best flyers were not equal to the feat of keeping me company, when walking at my usual pace; hence I inferred that _velocity_ was a necessary element in flight, and that gravity, so fatal to human attempts to fly, might be made a powerful auxiliary when rightly used. Acting upon this hint, I made experiments with heavy barn yard fowls, and finally constructed a light apparatus to be operated by myself, using, principally, my feet as a motive power, which I repeatedly tried with various and _constantly increasing_ degrees of success. Now I am satisfied that my system is right. It is my sober conviction that the time to realize the dream and hope of ages has come. Startling as the announcement may be, I propose not only to make short excursions through the air myself, but to teach others to do the same. Yet, knowing perfectly the obstacles in the way of flight, and knowing equally well how to overcome them, I am yet well aware that I must perfect my knowledge by practice before entire success can be achieved. This is only reasonable. How was it with the swimmer; how was it with the agile and dexterous skater; how with the acrobat, and what but practice has just enabled WESTON to walk one hundred and twelve miles in twenty-four hours, and four hundred miles in five days? For want of a better name, I will call the machine upon which I am to practice, the "Instructor." It is simple, but it gives the learner just what he wants--an endless series of _inclined planes_. It will prevent accidents, and until the student has mastered the mechanical movements necessary to flight, will supplement his efforts by partially balancing his weight. It consists of a beam fifty feet long, poised and attached by a universal joint to the top of a form post, say twenty feet or more in height. Upon one end of this beam the practitioner stands, arrayed in his wings. A movable weight at the other end completes the apparatus; and yet this simple machine, will form the entering wedge to aerial navigation. And now methinks I see you smile, but, my unbelieving friends, let me remind you that COPERNICUS, and GALILEO, and FRANKLIN, and FULTON, and MORSE,--all better men than your humble servant, were laughed at before me. _Their_ work is done. Their monuments stand in all lands, and yet _one_ of this band of truly great and worthy names still lives, and to him I am indebted for many kind and encouraging words. It is little besides this that I ask of _you_. The stock which you are solicited to take in this enterprise is small. But enable me by your patronage to devote myself for a time wholly to my project. See to it, that I do not fail for want of support. Buy my little pamphlet at its insignificant cost, ask your friends to do so; and should any of you wish to contribute anything more to this cause, which I have made my own, and which I am determined to push to a triumphant issue, he may be sure that he will receive the acknowledgments of a grateful and earnest man, who has himself devoted to it the aspirations and efforts of a long life, and who is still willing to take all the risks of failure upon himself. The undersigned would be pleased to have friends interested in this subject, call upon him, when the matter will be more fully described. ROBERT HARDLEY, 17 PERRY STREET, or 114 Sixth Ave., cor. 9th St. [Illustration: THE AERIAL MACHINE.] REMARKS ON THE ELLIPSOIDAL BALLOON, PROPELLED BY THE _Archimedean Screw_, DESCRIBED AS THE NEW AERIAL MACHINE, NOW EXHIBITING AT THE ROYAL ADELAIDE GALLERY, LOWTHER ARCADE, STRAND. REMARKS, &c. The object proposed in the construction of the Machine which is here presented to the public view, is simply to illustrate and establish the fact, that, by a proper disposition of parts and the application of a sufficient power, it is possible to effectuate the propulsion or guidance of a Balloon through the air, and thus to prepare the way for the more perfect accomplishment of this most interesting and desirable result. In the contrivance of this design, one of the first effects aimed at was to reduce the resistance experienced by the Balloon in its progress, which is greater or less according to the magnitude and shape of its opposing surface. To this intent is the peculiar _form_ of the Balloon, which is an _Ellipsoid_ or _prolate spheroid_, the axis of which is twice its minor diameter; in other words, twice as long as it is broad. By this construction the opposition to the progress of the Balloon in the direction of either end is only one _half_ of what it would be, had it been a Balloon of the ordinary spherical form and of the same diametrical magnitude. For the exact determination of this proportion we are more particularly indebted to the researches of Sir George Cayley, a distinguished patron of the art, who, a few years back, instituted a series of experiments with a view to ascertain the comparative amounts of resistance developed by bodies of different forms in passing through the air; the results of which he communicated to the world in an essay first published in the Mechanic's Magazine, and afterwards in a separate pamphlet. According to these experiments it appears, that the opposition which an ellipsoid or oval (of the nature of the Balloon, if we may so call it, in the model) is calculated to encounter in proceeding _endways_ through the atmosphere is only _one-sixth_ of what a _plane_ or _flat_ surface of equal area with its largest vertical section, would experience at the same rate; while the resistance to the progress of a globe, such as the usual Balloon, would be one third of that due to a similar circular plane of like diameter: shewing an advantage, in respect of diminished resistance, in favour of the former figure, to the extent we have above described; an advantage it enjoys along with an increased capacity for containing gas--the cubical contents of an ellipsoid of the proportions here observed, being exactly double of those of an ordinary Balloon of equal diameter, and consequently competent to the support of twice the weight. Independent of the advantage of reduced resistance in this form, there is another of nearly, if not quite, equal importance, in the facility it affords of directing its course; an object scarcely, if at all, attainable with a Balloon of the usual description however powerfully invested with the means of motion; as any one will readily perceive who has ever noticed or experienced the difficulty, or rather the impossibility, of guiding a tub afloat in the water, compared with the condition of a boat or other similarly constructed body, in the same element. The efficacy of this provision and its necessity will appear more forcibly when we observe that whenever the Balloon in the machine here described is thrown out of its direct bearing by the shifting of the net-work which connects it with the hoop, or by any other accident whereby its position is altered with respect to the propelling power, its course is immediately affected, and it ceases to progress in a straight line, following the direction of its major axis, unless corrected by the intervention of a sufficient rudder. The second object, after establishing a proper form for the floating body, was to contrive a disposition of striking surface that should be able to realise the greatest amount of propulsive re-action, in proportion to its magnitude and the force of its operation, which it is possible to accomplish. To shew by what steps and in consequence of what reasoning this point was determined as in the plan adopted, would occupy considerably more space than the few pages we have to spare would admit of our devoting to it. Suffice it to say that of all the means of creating a resistance in the atmosphere capable of being applied to the propulsion of the Balloon, the Archimedean Screw was ascertained to be undoubtedly the best. It is true that by a _direct_ impact or stroke upon the air, as for instance by the action of a fan, or the wafting of any _flat_ surface at _right angles_ to its own plane, the maximum effect is accomplished which such a surface is capable of producing with a given power. The mechanical difficulties, however, which attend the employment of such a mode of operation are more than sufficient to counterbalance any advantage in point of actual resistance which it may happen to possess; at least in any application of it which has hitherto been tried or proposed: so that here, as in the case of ships propelled by steam, the _oblique_ impact obtained by the rotation of the striking surface is found to be the most conducive to the desired result; and of these, that arrangement which is termed the Archimedean Screw is the most effective. The result aimed at, being the development of the greatest amount of re-action in the direction of the axis of revolution, it is not enough to have determined the _general_ character of the instrument to be employed; the proper disposition or inclination of its parts becomes a question of the first importance. According as the _turns_ of the screw are more or less oblique with respect to the air they strike or the axis on which they revolve, more or less of the resistance they generate by their rotation becomes _resolved_, as it is technically expressed, in the direction of the intended course: in other words, converted to the purpose in view, namely, the propulsion of the Balloon. Our limited space here again prevents us from entering into a detail of the experiments by means of which the true solution of this question has been arrived at, and the proper angle determined at which the superficial spiral exercises the greatest amount of propulsive force of which such an engine is capable. These experiments have been chiefly carried on by Mr. Smith, the ingenious and successful adapter of this instrument to the propulsion of steam vessels, for a series of years, with the greatest care, and at a very considerable expense; and the result of his experience gives an angle of about 67° or 68° for the outer circumference of the screw, as that productive of the maximum effect; a conclusion which is further verified by the experiments of Sir George Cayley, of Mr. Charles Green, the most celebrated of our practical aeronauts, and others who have employed their attention upon the subject. This conclusion requires only one modification, which ought to be noticed; namely, that in cases of extreme velocity, the number of the angle may be still further increased with advantage, until an inclination of about 73° be obtained; when it appears any further advance in that direction is attended with a loss of power. With these facts in view, the impinging surface of the Archimedean Screw, in the model under consideration, has been so disposed as to form, at its outer circumference, an angle of 68° with the axis of revolution, gradually diminishing as it approaches the centre, according to the essential character of such a form of structure. The novelty of the application of this instrument to the propulsion both of ships and balloons, suggests the propriety of a few more explanatory remarks to elucidate its nature and meet certain objections which those who are ignorant of its peculiar qualities are apt to raise in respect of it. Previous to the adoption of this particular instrument, various analogous contrivances had been resorted to in order to produce the same effects. Of these, examples are afforded in the sails of the windmill, the vane of the smoke jack, and of more modern introduction, the _propellers_ designed by Mr. Taylor for the equipment of steam-boats, and which Mr. Green has availed himself of to shew the effect of atmospheric re-action in directing the course of the balloon. Now all these and similar expedients are merely modifications of the same principle, more or less perfect as they more or less resemble the perfect screw, but all falling far short of the efficacy of that instrument in its primitive character and construction. The reason of this deficiency can be readily accounted for. All the modifications alluded to, which have hitherto been applied to the purposes of locomotion, are adaptations of _plane_ surfaces. Now it is the character of _plane_ surfaces to present the same angle, and consequently to impinge upon the air with the same condition of obliquity throughout. But the _rate_ of revolution, and consequently of impact, varies according to the distance from the axis; being greatest at the outer edge, and gradually diminishing as it approaches the centre of rotation, where it may be supposed to be altogether evanescent. Now it is by the re-action of the air against _one_ side of the impinging plane, that the progressive motion is determined in the opposite direction, which re-action is proportioned to the _rate_ of impact, the angle remaining the same. If then we suppose a re-action corresponding to the _greatest rate_ of revolution, which is that due to the _outermost_ portion of the impinging surface (that most removed from the axis of rotation) we shall have a _progressive_ motion in the whole apparatus greater than the rate of impact of the _innermost_ or more central portions of the revolving plane; and accordingly the re-action will be thereabouts transferred from the back to the front of the propulsive apparatus, and tend to retard instead of advancing the progress of the machine to which it is attached. This inconvenience is felt and acknowledged by all those who have employed this principle to obtain a progressive motion, and accordingly a provision has been made against it in the _removal_ or _reduction_ of the central portion of the revolving vanes, with a view to let the air escape or pass through as the instrument advances; a provision which is certainly effectual to that end, but at the cost of the _surface_, which is the ultimate source of the required re-action. All this is avoided in the use of the perfect screw. There, the rate of rotation and the angle of impact mutually corresponding, may be said to play into each other's hands; the spiral becoming more extended as the impact becomes less forcible, that is as it approaches the centre, where both altogether vanish or disappear; thus obviating the possibility of any interruption to the course of the machine from the contrarious impact of the air, however quick or however slow the motions, either of the screw itself or of the machine which is propelled by its operation. In attestation of this fact and as showing the immunity of the perfect screw from the disparaging effects experienced by the other modes of accomplishing the same object, I will only mention a circumstance related to me by Mr. Smith himself, to whom I am glad to acknowledge myself indebted for so much valuable information respecting this instrument, which, by the light he has thrown upon its use and the improvements he has introduced into its construction, he may be truly said to have made his own. Upon a late occasion, when trying one of the larger class of vessels which had just been furnished by him upon this principle, some persons not perceiving the true nature of the figure employed, contended that some opposition must be experienced by the central portion of the screw, which revolved so much less rapidly than the rate of the ship itself. In order to convince them of their error, Mr. Smith caused a portion of the surface in question, next the axis, to a certain distance, to be cut away, leaving an opening, by which, for the water to escape. The result was, immediately the loss of one mile an hour in the rate of the ship; thus shewing that even the most apparently feeble portion of the impinging surface of this instrument contributes, in its degree, to the constitution of the aggregate force of which it is productive. This peculiarity of construction is the main cause of the advantage which the Archimedean Screw possesses over all its types or imitations; but it is not the only one. The _entirety_ or _unbroken continuity_ of its surface is another, not much less influential. The value of this will be the more readily appreciated when we consider that air, unlike water and other non-elastic fluids, undergoes a rarefaction or impoverishment of density, and consequently of resisting power, accordingly as it is swept away by the rapid passage of impinging planes; the parts immediately _behind_, and to a considerable distance, being thereby relieved from the support they had previously experienced, and extending (and consequently becoming thinner) in order to fill up the space thus partially cleared away. Now it is evident that if other planes be brought into operation in the parts of the atmosphere thus impoverished, before they have had time to recover their pristine or natural density, they will of necessity act with diminished vigour; the resistance being ever proportioned to the density of the resisting medium. This is the condition into which, more or less, all systems of revolving planes are necessarily brought, that consist of more than one; and is a grand cause of the little real effect they have been made capable of producing, whenever tried. The nature of this objection, and the extent to which it operates, will appear most strikingly from the following fact. Mr. Henson's scheme of flight is founded upon the principle of an inclined plane, started from an eminence by an extrinsic force, applied and _continued_ by the revolution of impinging vanes, in form and number resembling the sails of a windmill. In the experiments which were made in this gallery with several models of this proposed construction, it was found that so far from _aiding_ the machine in its flight, the operation of these vanes actually _impeded_ its progress; inasmuch as it was always found to proceed to a greater distance by the mere force of acquired velocity (which is the only force it ever displayed), than when the vanes were set in motion to aid it--a simple fact, which it is unnecessary to dilate upon. It is to the agency of this cause, namely, the broken continuity of surface, that, I have no doubt, is also to be ascribed the failure of the attempt of Sir George Cayley to propel a Balloon of a somewhat similar shape to the present, which he made at the Polytechnic Institution a short while since, when he employed a series of revolving vanes, four in number, disposed at proper intervals around, but which were found ineffectual to move it. Had these separate surfaces been thrown into _one_, of the nature and form of the Archimedean Screw, there is little doubt that the experiment would have been attended with a different result. In accordance with the principles here illustrated, the Archimedean Screw properly consists of only _one_ turn; more than one being productive of no more resistance, and consequently superfluous. A single unbroken turn of the screw, however, when the diameter is of any magnitude, would require a considerable length of axis, which in its adaptation to the Balloon, would be practically objectionable; accordingly _two half turns_, nearly equivalent in power to one whole turn, has been preferred; as in most instances it has been by Mr. Smith, himself, in his application of it to the navigation of the seas, Indeed, in all other respects, except the nature of its material, the screw here represented is exactly analogous to that used by Mr. Smith in its most perfect form, having been, in fact, designed, and in part constructed under his own supervision.[A] The model upon which these principles have been now, for the first time, successfully, at least, tried in the air, is constructed upon the following scale. The Balloon is, as before stated, an ellipsoid or solid oval; in length, 13 feet 6 inches, and in height, 6 feet 8 inches. It contains, accordingly, a volume of gas equal to about 320 cubic feet, which, in pure hydrogen, would enable it to support a weight of twenty-one pounds, which is about its real power when recently inflated, and before the gas has had time to become deteriorated by the process of _endosmose_.[B] The whole weight of the machine and apparatus is seventeen pounds; consequently there is about four pounds to spare, in order to meet this contingency. [Footnote A: The frame was made at Mr. Smith's request, by Mr. Pilgrim, of the Archimedes; the original experimental vessel in which this mode of propulsion was first tried upon the large scale. Mr. Pilgrim has been long versed in all that relates to the mechanism of this instrument, and is indeed a most expert and ingenious artist.] [Footnote B: _Endosmose_ is that operation by which gases of different specific gravities are enabled, or rather forced to come together through the pores of any membranous or other flexible covering by which it is sought to restrain them. As above referred to, it is the introduction of atmospheric air into the body of the Balloon through the pores of the silk, however accurately varnished, by which the purity of the hydrogen gas is contaminated, and its buoyant power ultimately exhausted This it is impossible to prevent by any process, except the interposition of a _metallic_ covering; as for instance, by _gilding_ the Balloon, which would be effectual could it be contrived to endure the constant friction and bending of the material itself.] Beneath the centre of the Balloon, and about two-thirds of its length, is a frame of light wood, answering to the hoop of an ordinary Balloon; to which are attached the cords of the net which encloses the suspending vessel, and which serves to distribute the pressure of the appended weight equally over its whole surface, as well as to form an intermediate means of attachment for the rest of the apparatus. This consists of a car or basket in the centre; at one end the rudder, and at the other the Archimedean Screw. The car is about two feet long and eighteen inches broad, and is laced to the hoop by cords, which running through loops instead of being fastened individually, allow of unlimited play, and equalize the application of the weight of the car to the hoop, as of the whole to the Balloon above. The Archimedean Screw consists of an axis of hollow brass tube eighteen inches in length, through which, upon a semi-spiral of 15° of inclination, are passed a series of radii or spokes of steel wire, two feet long, (thus projecting a foot on either side) and which being connected at their outer extremities by two bands of flattened wire, form the frame work of the Screw, which is completed by a covering of oiled silk cut into gores, and tightly stretched, so as to present as nearly uniform a surface as the nature of the case will permit. This Screw is supported at either end of the axis by pillars of hollow brass tube descending from the hoop, in the lower extremities of which are the holes in which the pivots of the axis revolve. From the end of the axis which is next the car, proceeds a shaft of steel, which connects the Archimedean Screw with the pinion of a piece of spring machinery seated in the car; by the operation of which it is made to revolve, and a progressive motion communicated to the whole apparatus. This spring is of considerable power compared with its dimensions, being capable of raising about 45 pounds upon a barrel of four inches diameter after the first turn, and gradually increasing as it is wound up. It weighs altogether, eight pounds six ounces. The rudder is a light frame of cane covered with silk, somewhat of the form of an elongated battledoor, about three feet long, and one foot wide, where it is largest. It might be made considerably larger if required, being exceedingly light and yet sufficiently strong for any force to which it could be subjected. It weighs altogether only two ounces and a half. This instrument possesses a double character. Besides its proper purpose of guiding the horizontal course of the Balloon, it is capable of being applied in a novel manner to its elevation or depression, when driven by the propulsive power of the Screw. Being so contrived as to be capable of being turned _flat_, and also directed upwards or downwards as well as to the right or left, it enables the aeronaut to transfer the resistance of the air, which, in any inclined position, it must generate in its passage, to any side upon which he may desire to act, and thus give a determination to the course of the Balloon in the opposite direction. This will appear more clear as well as more certain when we consider, that the aerial vessel being in a state of perfect equipoise, as it ever must be when proceeding on the same level, the slightest alteration in its buoyancy is sufficient to send it to a considerable distance either up or down as the case may be: the rejection of a pound of ballast, or of an equivalent amount of gas, being enough to conduct the aeronaut to the extremest limits of his desires in either direction, whatever may be the size of his Balloon. Now a resistance equal to many pounds is attainable by an inclined plane of even moderate dimensions when propelled even with moderate velocity; and being readily governed by the mere inclination of the impinging plane at the will and by the hand of the aerial voyager, it will be in his power to vary the level of his machine with very considerable nicety; enabling him to approach the surface of the earth, or in a gentle curve to sweep away from its occasional irregularities, and proceed to a very considerable elevation without interrupting the progress of his course, and, what is of more importance, without sacrificing any part of his resources in gas or ballast, upon the preservation of which the duration of his career so entirely depends. These properties of the rudder it is not possible to display in the present exhibition, owing to the confined nature of the course which it is necessary to pursue; but they were sufficiently tested in the preliminary experiments at Willis's Rooms, where the space being larger, a circular motion was conferred upon the machine by connecting it with a fixed centre round which it was thus made to revolve, without the necessity of confining it to the one level. The rate of motion which the Balloon thus equipped is capable of accomplishing varies according to the circumstances of its propulsion. When the Archimedean Screw precedes, the velocity is less than when it is made to follow, owing to the reaction of the air in the former instance against the car, the under surface of the balloon, and other obstacles, by which its progress is retarded. Again, when the cord upon which it travels is most tense and free from vibration, the rate is found to be considerably accelerated, compared with what it is when the contrary conditions prevail. But chiefly is its speed affected by the proper _ballasting_ of the machine itself, upon which, depends the friction it encounters from the cord on which it travels. Under ordinary circumstances it proceeds at a rate of about four miles an hour, but when the conditions alluded to have been most favourable, it has accomplished a velocity of not less than five; and there is no doubt that were it altogether free from restraint, as it would be in the open air, with a hand to guide it, its progress would be upwards of six miles an hour. Having now, I trust, sufficiently explained the principles exemplified in the model here described, it may be expected that I should add a few words regarding their reduction into practice upon a larger scale and in the open air, with such difficulties to contend with as may be expected to be encountered in the prosecution of such a design. In the first place, however, it will be necessary to disabuse the public mind of some very prevailing misconceptions with respect to the conditions of a Balloon exposed to the action of the winds, pursuing its course under the exercise of an inherent propulsive power. These misconceptions, which, be it observed, are more or less equally participated in by the scientific as by the ignorant, when devoid of that practical experience which is the basis of all aeronautical proficiency, are of a very vague and general character, and consequently not very easy accurately to define. In order, therefore, to make sure of meeting all the objections and removing all the doubts to which they are calculated to give rise, it will be advisable, even at the risk of a little tediousness, to separate them into distinct questions and treat them accordingly. One of the most specious of these misconceptions regards the effects of the resistance of the atmosphere upon the figure of the Balloon when rapidly propelled through the air, whereby it is presumed its opposing front will be driven in, and more or less incapacitated from performing the part assigned to it; namely, to cleave its way with the reduced resistance due to its proper form. To obviate, this imagined result, various remedies have been proposed--such as, to construct that part of the machine of more solid materials than the rest, or else (as suggested by one of the most scientific and ingenious of those who have devoted their attention to the theory of aerial navigation), to subject the gaseous contents of the Balloon to such a degree of artificial condensation by compression, as shall supply from within a force equal to that from without; adopting, of course, materials of a stronger texture than those at present in use, for the construction of the balloon. Now the contingency against which it is here sought to provide, and which I grant is a very reasonable one to anticipate, has nevertheless no real existence in practice; at least in such a degree as to render it necessary to have recourse to any particular expedient for its prevention. Taking it for granted that the hypothesis in which it is involved is founded upon a presumed analogy with a Balloon exposed to the action of the wind while in a state of attachment to the earth, I would first observe that the cases in question, however apparently analogous, are in reality essentially dissimilar. In the one case (that where the Balloon is supposed to be attached to the earth) all the _motion_, and consequently all the _momentum_, is in the air; in the other case (where the Balloon is supposed to be progressive), it is in the constituent particles of the machine itself and of its gaseous contents. And this momentum, which is ever proportioned to the rate of its motion, and, consequently, to the amount of resistance it experiences, is amply sufficient to secure the preservation of the form of its opposing front, however partially distended, and whatever the velocity with which it might happen to be endowed. Independently, however, of this corrective principle, another, equally efficacious is afforded in the buoyant power of the included gas, which, occupying all the upper part of the Balloon so long as it is in a condition to sustain itself in the air, and generally extending to its whole capacity, presses from within with a force far greater than any it could experience from the external impact of the atmosphere, and sufficiently resists any impression from that quarter which might tend to impair its form. To what extent this is effective, will appear more clearly when we observe that in any balloon inflated, it is the _sides_ of the distended globe that bear out the weight of the appended cargo, through the intervention of the network; a weight only limited by the sustaining power of the machine itself, and in the case of the great Vauxhall or Nassau Balloon, amounting to more than two tons, and consequently pressing with a force far exceeding any that could arise from the impact of the air at any rate of motion it could ever be expected to accomplish. And this statement, which represents the theoretical view of the question, is fully borne out by the real circumstances of the case as they appear in practice. So far from justifying the apprehensions of those who conceive that the _front_ of the Balloon would be disfigured by its compulsory progression through the air, the result is exactly the reverse; the only tendency to derangement of form displaying itself in the part _behind_, where the rushing in of the atmospheric medium to fill the place of the advancing body (in the nature of an _eddy_, as it is termed in water), might and no doubt would, to some extent (though perhaps but slightly) affect the figure of that part, in a manner, however, calculated rather to aid than to impair the general design in view, Another error of more universal prevalency, because of a more superficial character, regards the condition of the Balloon as affected by the currents of air, in and through which it might have to be propelled. The arguments founded upon such a view of the case, generally assume some such form as the following--"It is true you can accomplish such or such a rate of motion; but that is only in a room, with a calm atmosphere, or with a favourable current of wind. In the open air, with the wind at the rate of twenty or thirty miles an hour, your feeble power would be of no avail. You could never expect to direct your course _against_ the wind, and if you were to attempt it and the wind were strong, you would inevitably be blown to pieces by the force of the current." Now this argument is equally nought with the preceding. The condition of the Balloon, as far as regards the exercise of its propulsive powers, is precisely the same whether the wind be strong or gentle, with it or against it. In neither case would the Balloon experience any opposition or resistance to its progress but what _itself_, by its _own_ independent motion, created; and that opposition or resistance would be exactly the same in whatever direction it might be sought to be established. The Balloon, passively suspended in the air, without the exercise of a propulsive power, experiences no effects whatever from the motion of the atmosphere in which it is carried, however violent; and the establishment of such a propulsive power could never subject it to more than the force itself, with which it was invested. The _way_ which the Balloon so provided would make through the air would always be the same, in whatever direction, or with whatever violence the wind might happen to blow; and the condition of the Balloon would always be the same that was due to its _own independent_ rate of motion, without regard to any other circumstances whatever. If it was furnished with the means of accomplishing a rate of motion equal to ten miles an hour, it would experience a certain amount of atmospheric resistance due to that rate; and this amount of resistance with all its concomitant consequences, neither more nor less, would it experience, whether it endeavoured to make this way _against_ a wind blowing at the rate of 100 miles an hour, or _with_ the same in its favour. The result, so far as regards its distance from the place of starting, would, I grant, be very different; but at present we are only considering the conditions of its motion through the _air_, and these, I repeat, would be the same whatever the rate or course of the wind; so that all speculations on this score must resolve themselves into questions of _quantity_, not of _quality_, in the effect sought to be accomplished: in other words, all consideration of the rate of the wind must be left out of the argument, except, in so far as it shall be taken to regulate the limit which shall be assigned to the rate of the aerial machine, as sufficient to justify its claims to the title of a successful mode of navigating the skies.[A] [Footnote A: The condition of a Balloon propelled by machinery is very analogous to that of a boat in the water driven by oars or paddles. Suppose such a boat to be rowing or paddling up a river against the stream, if a piece of cork be thrown overboard it appears to be carried away with the current. But this is delusive; it is the boat _alone_ which really moves away from the cork. For if the boat be left to its own course, both it and the cork will float down together; and if the use of the oars or paddles be resumed, the distance between the boat and the cork will proceed to develope itself exactly according to the rate of the _boat_, without any regard to that of the _stream_. If the stream be excessively rapid, the boatsmen will appear to be exercising very great force to enable them to stem the torrent and avoid being carried backward. Now the resistance which they experience and all its attendant effects are only those which they create for themselves, and which they would experience in exactly the same degree were they to endeavour to move _at the same rate_ in calm water or with the current in their favour. If the current be at the rate of ten miles an hour and they are just able to maintain their place, they are proceeding at the rate of ten miles an hour, and they experience the opposition due to that rate of motion; precisely the same as they would experience if they sought to accomplish the same rate of motion under any other circumstances. And if the current were 100 miles an hour, they would suffer no more from endeavouring to go against it, with the force just ascribed to them, than if they were to exercise the same force in any other direction, or in a water perfectly tranquil. Apply this reasoning to the case of a Balloon propelled by machinery, and much of the obscurity in which it is involved will disappear.] With these conditions established, it will now be seen that we have nothing to consider, in discussing the probable success of any scheme of aerial navigation with the aid of the Balloon (so far as its mere movements are concerned)[A] except the _actual rate of motion_ which it is competent to accomplish; whether or not it be sufficient to meet the exigencies of the case as they may happen to be estimated. That its capabilities in that respect, be displayed within a room, or in a calm atmosphere, or under what may be called the most favourable circumstances, has nothing in it to disparage or affect the general question. Whatever it can do _there_, it can do the same in a hurricane; and the only real question is, "whether, what it _can_ accomplish in respect of rate, is enough to answer the purpose in view." [Footnote A: I have said "so far as its mere movements are concerned;" because the complete success of the scheme, how far it is an available and satisfactory mode of transport, depends upon other conditions besides the accomplishment of a given rate of motion--as for instance, whether it be safe, or practicable, or consistent with a due preservation of the _buoyancy_ of the Balloon, so as to allow of its being employed in voyages of sufficient distance and duration, or capable of being worked at moderate cost, or whether it leave sufficient allowance for cargo; with many others of less striking importance, which the practical aeronaut will readily suggest for himself.] The model we have been just describing is capable as we have seen, of accomplishing a rate of about six miles an hour. Now the resistance to the progress of a Balloon varies as the squares of the velocities or rates of motion. Accordingly, for the same Balloon to accomplish twice the speed, or twelve miles an hour, it would be necessary to be provided with four times the power. Thus as the spring power employed in the model is equal to a weight of 45 pounds, upon a barrel of four inches in diameter, it would require one competent to raise 180 pounds on the same sized barrel, to enable it to propel the same Balloon at double the present rate. But with regard to Balloons of different sizes and of the same shape, the power required to produce the same rate of motion, would be as the squares of their respective diameters: for the power is as the resistance, the resistance as the surface, and the surface follows the proportion just assigned. In order, therefore to propel a Balloon of the same form and twice the diameter, at the same rate, it would require a force of four times the amount. Now to apply this to the consideration of a Balloon of superior magnitude, let us assume one of 100 feet in length, and fifty feet in height. The buoyant power of such a machine, or the weight it would carry, supposing it inflated with gas of the same specific gravity, compared with that of the model, would be as the cubes of their respective diameters; or in, about, the ratio of 420 to one. Such a Balloon, therefore, so inflated, would carry a weight of about 8700 pounds, or above three tons and three quarters. As, however, it would be very expensive to inflate such a vessel with pure hydrogen gas, it would be advisable to found our calculations upon the use of coal gas; under which circumstances the weight it would carry would be limited to about three tons. Deducting from this, one ton for the weight of the Balloon itself and its necessary equipments, there would remain two tons, or about 4500 pounds, to be devoted to the power, whatever it might be, by which the machinery was to be moved, and the living cargo it might have to carry. Nor let the reader be surprised at the magnitude of the figures we are here employing, as if it were something extraordinary or beyond the power of man to accomplish. The dimensions and power we have here assumed is very little greater than those of the great Vauxhall Balloon,[A] and considerably less than some of _Montgolfières_, or Fire-balloons, which were first employed. [Footnote A: The height of the Vauxhall Balloon is about eighty feet, its breadth about fifty. It contains 85000 cubic feet of gas, and supports a weight of upwards of two tons.] Now the resistance which such a Balloon as I have here described would experience in its passage through the air, and consequently the power it would require to establish that resistance compared with those of the model, we have said would be as the _squares_ of their respective diameters, or in, about, the ratio of only fifty-six to one; in other words, whatever force it would take to propel the model at any given rate, it would require just fifty-six times the power to accomplish the same result with the large Balloon we have been describing. In order to ascertain precisely what this power would be in any given instance, it only remains to find an expression for the spring power with which we have been hitherto dealing, that shall be more generally comprehensible. This we shall do by a comparison with the power of steam, according to the usual mode of estimating it; that is, reckoning a one-horse power to be equal to the traction or draught of 32,000 lbs. through the space of one foot in a minute. According to this scale, observing the corresponding conditions of the spring--namely, the weight it balances on the barrel, (answering to the force of traction) = 45 lbs., the circumference of the barrel (answering to the space traversed) = one foot, and the time of uncoiling for each turn, (answering to the rate of the operation) say, three seconds and a half--we find the power of the spring employed in the propulsion of the model, to be as nearly as possible the forty-second part of the power of one horse; from whence it is easy to deduce the conditions of flight assignable to the same, and to different sized Balloons of the same shape, at any other degree of speed. Assuming, for instance, a Balloon of 100 feet in length and 50 feet in height, and proposing a rate of motion equal to 20 miles an hour, we have, in the first instance, the power required to propel the model at that rate, compared with that already ascertained for a velocity of six miles an hour, in the ratio of the _squares of the two velocities_, as nearly ten to one; that is, ten forty-seconds, or about one-fourth of a horse power. To apply this to the larger Balloon, we must take the squares of their respective diameters; which being nearly in the ratio of 56 to 1, gives an amount of 56 times one-fourth or about 14 horses, as the sum of the power required. From what particular source the power to be employed in the propulsion of the Balloon should be deduced, is not indeed a question without some difficulties and doubts in the determination. To all the moving powers at present before the world some objections apply which disparage their application, or altogether exclude them from our consideration. The power of the coiled spring is too limited to be employed upon a larger scale. The use of the steam-engine is accompanied with a gradual consumption of the resources of the Balloon in ballast, and consequently in gas, the one being exactly answerable to the other, and is therefore not calculated for voyages of long duration. Human strength appears to be too feeble for great results, and moreover, requires repose; which reduces the amount assignable to each man to a fraction of its nominal value. Of electro-magnetism as yet we know too little to enable us to pronounce upon it with certainty. Of the remaining powers known only one is worth mentioning in connexion with this subject, namely, the elastic force of air; and this I only mention because it has been taken up by one whose authority in these matters is deservedly entitled to much weight, and who entertains great hopes of making it ultimately subservient to the purpose in view. But although none of these powers, in their present state, be so perfectly adapted to the propulsion of the Balloon as to leave nothing further to desire, yet are some of them so far applicable as, undoubtedly, to enable us to accomplish, by their means, a very large amount of success. A steam engine of the power required, namely, equal to fourteen horses, could be easily constructed, far within the limits of weight which we have at our disposal upon that account in the Balloon under consideration, or even in one much smaller; and recent improvements have so far reduced the amount of coal required for its maintenance, that perhaps as long a voyage could be made by means of it now, as would be expected or required. Even human strength, by a certain mode of applying it, might be made effectual to the accomplishment of a very sufficient rate of motion, say fourteen or fifteen miles an hour, for, continuously, as long a period as the natural strength of man, moderately taxed, could endure, and which we may reckon at twelve hours. It is true that neither the velocity here quoted, nor that before assumed is so great as to enable the aeronaut to compete with some of the modes of transit employed on the surface of the earth; as, for instance, the railroads, where 25 miles an hour is not an unusual speed. Yet is not the aerial machine which could command such a rate of motion to be despised, or set aside as inferior in actual accomplishments to what is already at our disposal; for it must not be lost sight of, that railroads, or terrestrial roads of every description, must ever be limited in their extent and direction, and travelling on them, however perfectly contrived, subject to deviations and interruptions, particularly in passing from one country to another beyond the seas, which if taken into account, would reduce the apparent estimate of their rates, considerably under the lowest of those assigned to the Balloon in the previous calculation; and at all events, by sea, much less, under the most favourable circumstances is the ordinary rate of ships. But, it may be observed, we are here counting upon a rate of motion as established, which is only effectual to that extent in the absence of contrary currents of wind. This is true; nevertheless it is no bar to the use which might be made of the aerial conveyance so furnished, nor any disparagement to the advantages which might be drawn from it; for not only does the aeronaut possess the means of choosing, within certain limits, the currents to which he may please to commit himself, and of which, abundance of every variety is sure to be met with at some elevation or other in the atmosphere, but, as in all general arguments, where the conditions are equally applicable to both sides of the question, they may be fairly left out as neutralising each other, so, here it must not be forgotten, that the currents in question, being altogether indeterminate, and equally to be expected from all quarters, an equal chance exists of advantages to be derived, as of disadvantages to be encountered from their occurrence; and that, even without the means of making a selection, the admitted laws of reasoning would justify us in considering the chances of the latter to be fully counterbalanced by those of the former. It is enough, for moderate success at least, if, possessing the power of avoiding the bad, and of availing himself of the good, the aeronaut be furnished with the means of making a sufficient progress for himself when the atmosphere is such as neither to favour nor to obstruct him; and in this condition I humbly conceive he would be placed, with even a less rate of motion than that which we have before assigned, and confidently reckon upon being able to accomplish. FINIS. 
12227	----	Child's First Picture Book [Illustration: Book Cover] [Illustration] CHILD'S FIRST PICTURE BOOK [Illustration] * * * * * [Illustration] THE FIRE HORSES stand ready in their stalls, and at the sound of the alarm gong the stall chains are let down and each horse goes quickly to his place at the engine, and the big iron collars are clamped around their necks and off they go to the fire, with the engine, at break-neck speed. * * * * * [Illustration: The Alarm] * * * * * [Illustration] THE AUTOMOBILE FIRE ENGINE can go to the fires very swiftly. Many times the saving of a few minutes by the firemen in reaching a fire means stopping the blaze before it becomes too great. * * * * * [Illustration: A Dangerous Fire] * * * * * [Illustration] THE BRAVE FIREMAN rescues many people who are caught in burning buildings, in this way risking his life that others may be saved from the smoke and flames. Many people owe their lives to the bravery of the firemen. * * * * * [Illustration] THE HOSE NOZZLE has been taken up to the roof of a building next the one afire and the firemen are sending the water into the upper floors of the burning building. The hose nozzle is very difficult for the firemen to hold. * * * * * [Illustration: Hook and Ladder Truck Going to the Fire] * * * * * [Illustration] THE FIRE ALARM is sounded by a big gong in the station from street alarm boxes near where the fire occurs. The firemen know these alarm stations so well that they seldom look for the address, but dash off quickly to the correct place. * * * * * [Illustration: A Water Tower] * * * * * [Illustration] THE FIREMEN'S DOG goes to every fire, running beside the horses, barking a command to hurry. He gets to the fire hydrant first and sits there panting until the Firemen come up to attach the hose and turn on the water. * * * * * [Illustration] THE ROUND HOUSE is the place where the railroad engines are kept when they are not working. The engines are turned around on a big turn table so each can be run on the different tracks which all lead to the turn-table in the center. * * * * * [Illustration: Passing a Signal Tower] * * * * * [Illustration] THE WATER TANK is seen frequently along the route of the railroads and plenty of water must be taken on and carried in the engine tender to make steam which is the power used to drive the big engines. * * * * * [Illustration] AN OBSERVATION TRAIN is often made up to follow the great college boat races, where the railroad runs along the river bank. Flat cars are used with seats fixed on them for the spectators. * * * * * [Illustration: The Circus is Coming to Town] * * * * * [Illustration] THE TRAIN FERRY carries entire trains across rivers where there are no bridges. Some of the largest train boats have several tracks and carry a train on each. The boats are tied in slips at the shore so that the tracks meet exactly those on the land. * * * * * [Illustration] THE STAGE COACH is used in the country where towns are few. The stages meet trains at the stations and take on passengers to be carried to their homes away from the railroad. Some of the stage routes are several hundred miles long. * * * * * [Illustration: Engineer and Fireman] * * * * * [Illustration] THE TUNNELS are passages for trains under mountains, hills and rivers. The tunnels are dark but the trains are well lighted. Electric motors are often used, this avoids the smoke of steam engines which is very unpleasant in the tunnels. * * * * * [Illustration: Field Artillery] * * * * * [Illustration: Whippet Tank] * * * * * [Illustration: Raising Gun Up Mountainside] * * * * * [Illustration: Dirigible Balloon] * * * * * [Illustration: A Swift-going Motor Cycle With Machine Gun] * * * * * [Illustration: A Battle Motor Car] * * * * * [Illustration: Anti-aircraft Gun] * * * * * [Illustration: Army Band] * * * * * [Illustration: Aeroplane] * * * * * [Illustration: Blanket Tossing] * * * * * [Illustration: Sailor Band] * * * * * [Illustration: Battleship And Giant Submarine] * * * * * [Illustration: A Sea Sled] * * * * * [Illustration: Laying Mines] * * * * * [Illustration: Troopship Homeward Bound] THE FLAGS OF THE ALLIES United in defense of Freedom in the great war in Europe. May we honor them forever, and always prove worthy of our flag which we love best. * * * * * [Illustration: Wooden Battleships Of Olden Days] THE FLAGS OF THE ALLIES These are truly the Flags of Freedom. The countries represented through bravery and sacrifice have made the world a safe place to live in. * * * * * [Illustration: A Fast-going Patrol Motor Boat] * * * * * [Illustration: Cutter Drill] * * * * * [Illustration: Seaplane Destroying Submarine] 
1445	----	None 
24570	----	None 
19911	----	Union Calendar No. 928 86th Congress, 2d Session House Report No. 2091 THE PRACTICAL VALUES OF SPACE EXPLORATION REPORT OF THE COMMITTEE ON SCIENCE AND ASTRONAUTICS U.S. HOUSE OF REPRESENTATIVES EIGHTY-SIXTH CONGRESS SECOND SESSION PURSUANT TO H. Res. 133 [Serial I] July 5, 1960.--Committed to the Committee of the Whole House on the State of the Union and ordered to be printed UNITED STATES GOVERNMENT PRINTING OFFICE 58231° WASHINGTON: 1960 COMMITTEE ON SCIENCE AND ASTRONAUTICS OVERTON BROOKS, Louisiana, _Chairman_ John W. McCormack, Massachusetts George P. Miller, California Olin E. Teague, Texas Victor L. Anfuso, New York B. F. Sisk, California Erwin Mitchell, Georgia James M. Quigley, Pennsylvania Leonard G. Wolf, Iowa Joseph E. Karth, Minnesota Ken Hechler, West Virginia Emilio Q. Daddario, Connecticut Walter H. Moeller, Ohio David S. King, Utah J. Edward Roush, Indiana Thomas G. Morris, New Mexico Joseph W. Martin, JR. Massachusetts James G. Fulton, Pennsylvania Gordon L. McDonough, California J. Edgar Chenoweth, Colorado Frank C. Osmers, JR. New Jersey William K. Van Pelt, Wisconsin A. D. Baumhart, JR. Ohio Perkins Bass, New Hampshire R. Walter Riehlman, New York CHARLES F. DUCANDER, _Executive Director and Chief Counsel_ DR. CHARLES S. SHELDON II, _Technical Director_ SPENCER M. BERESFORD, _Special Counsel_ PHILIP B. YEAGER, _Special Consultant_ JOHN A. CARSTARPHEN, Jr., _Chief Clerk_ FRANK R. HAMMILL, Jr., _Counsel_ RAYMOND WILCOVE, _Staff Consultant_ RICHARD P. HINES, _Staff Consultant_ Lt. Col. FRANCIS J. DILLON, Jr., _Staff Consultant_ Comdr. HOWARD J. SILBERSTEIN, _Staff Consultant_ LETTER OF TRANSMITTAL HOUSE OF REPRESENTATIVES, COMMITTEE ON SCIENCE AND ASTRONAUTICS, _Washington, D.C., July 1, 1960._ Hon. OVERTON BROOKS, _Chairman, Committee on Science and Astronautics._ DEAR MR. CHAIRMAN: I am forwarding herewith for your consideration a staff study, "The Practical Values of Space Exploration." This study was undertaken pursuant to your request for information covering the various utilities of the national space effort. The study has been prepared by Philip B. Yeager and reviewed by other members of the professional staff. CHARLES F. DUCANDER, _Executive Director and Chief Counsel._ LETTER OF SUBMITTAL HOUSE OF REPRESENTATIVES, COMMITTEE ON SCIENCE AND ASTRONAUTICS, _Washington, D.C., July 5, 1960._ Hon. SAM RAYBURN, _Speaker of the House of Representatives, Washington, D.C._ DEAR MR. SPEAKER: By direction of the Committee on Science and Astronautics, I submit the following report on "The Practical Values of Space Exploration" for the consideration of the 86th Congress. OVERTON BROOKS, _Chairman_. CONTENTS Introduction 1 I. The unseen values 3 Some examples of the unexpected 3 The ultimate values 5 Steering a middle road 6 The time for space 7 II. National security values 9 The military uses 9 Our position in the international community 12 Space as a substitute for war 15 III. The economic values 17 U.S. expenditures on space 17 The spread of economic benefits 18 Creation of new industries 19 Research 19 New power sources 20 New water sources and uses 21 Noise and human engineering 22 High speed-light weight computers 22 Solid state physics 23 Economic alliances 24 Private enterprise in space 24 Jobs 27 Automation and disarmament 28 IV. Values for everyday living 31 Technological benefits 31 Food and agriculture 35 Communications 36 Weather prediction and modification 37 Health benefits 39 Education benefits 42 The demand 42 V. Long-range values 45 Trouble spots 45 Population 45 Water shortage 46 Soil erosion 46 Added leisure 47 Intensified nationalism 48 Limitations on space research 48 Fundamental knowledge about life 51 Psychological and spiritual values 52 Maturing of the race 53 +---------------------------------------------------------------+ | 86TH CONGRESS | | _2d Session_ | | | | HOUSE OF REPRESENTATIVES | | | | REPORT | | NO. 2091 | | | | | | | | | |THE PRACTICAL VALUES OF SPACE EXPLORATION | | | | * * * * * | | | |JULY 5, 1960.--Committed to the Committee of the Whole House on| |the State of the Union and ordered to be printed | | | | * * * * * | | | |Mr. BROOKS of Louisiana, from the Committee on Science and | |Astronautics, submitted the following | | | | REPORT | | | | [Pursuant to H. Res. 133] | | | +---------------------------------------------------------------+ THE PRACTICAL VALUES OF SPACE EXPLORATION INTRODUCTION This report has been undertaken for a special reason. It is to explain to the taxpayer just why so many of his dollars are going into the American effort to explore space, and to indicate what he can expect in return which is of value to him. Such an explanation, even after 2 years of relatively high-geared activity in the space exploration field, appears to be warranted. There is still a segment of the U.S. population which has little, if any, notion of the values that the space program has for the average citizen. To these people the expenditure of billions of dollars on missiles, rockets, satellites, Moon probes, and other space activities remains something of a mystery--particularly when so many other worthy projects throughout the land may be slowed or stalled for lack of funds. If, therefore, the practical value of the American space program is being questioned, it is a question which needs to be answered. It is interesting to note that the problem is not unique to the United States. In the Soviet Union, which counts itself as the world's prime investigator of space, there is likewise an element of citizenry which finds itself puzzled over the U.S.S.R.'s penchant for the interplanetary reaches. "What do sputniks give to a person like me?" a Russian workman complained in a letter which _Pravda_ published on its front page. "So much money is spent on sputniks it makes people gasp. If there were no sputniks the Government could cut the cost of cloth for an overcoat in half and put a few electric flatirons in the stores. Rockets, rockets, rockets. Who needs them now?"[1] It goes without saying that the workman was severely chastised by the Soviet newspaper, but his point was made. No matter where taxpayers live they want to know--and are entitled to know--what good a program of space exploration is to them. During the 1960's it is expected that the U.S. Government will spend anywhere from $30 to $50 billion on space exploration for all purposes, civilian and military. It is the intent of this report to delineate in lay language, and in terms which will be meaningful to those who have not followed the American space program closely, the reasons for this great investment and the probable returns. [Illustration: FIGURE 1.--A single shot of the 8-barreled Saturn of the future will cost millions of dollars, maybe tens of millions. What makes it worthwhile for the taxpayer?] FOOTNOTES: [1] Associated Press dispatch, dateline Moscow, June 12, 1960. I. The Unseen Values The United States has not embarked upon its formidable program of space exploration in order to make or perpetuate a gigantic astronautic boondoggle. There are good reasons, hard reasons for this program. But, in essence, they all boil down to the fact that the program is expected to produce a number of highly valuable payoffs. It not only is expected to do so, it is doing so right now. Many of the beneficial results can be identified. Those already showing up are detailed in the sections of this report which follow. They include the most urgent and precious of all commodities--national security. Beyond that, they also include a strengthened national economy, new jobs and job categories, better living, fresh consumer goods, improved education, increased health, stimulated business enterprise and a host of long-range values which may ultimately make the immediate benefits pale into relative insignificance. Practical uses such as those just listed mean the taxpayer is more than getting his money's worth from American space exploration--and getting a sizable chunk of it today. Nevertheless, if we can depend on the history of scientific adventure and progress, on its consistent tendencies of the past, then we can be reasonably sure that the greatest, finest benefits to come from our ventures into space are yet unseen. These are the unpredictable values, the ones which none of us has yet thought of. Inevitably they lag behind the basic research discoveries needed to make them possible, and often the discoveries are slow to be put to work after they are made. Investors, even governments, are human, and before they invest in something they normally want to know: What good is it? We can be sure that many American taxpayers of the future will be asking "what good is it?" in regard to various phases of the space program. There was an occasion when the great Scottish physicist, James Clerk Maxwell, was asked this question concerning one of his classic discoveries in electromagnetism. Maxwell replied: "What good is a baby?" Now, as then, it takes time for new knowledge to develop and become useful after its conception and birth. SOME EXAMPLES OF THE UNEXPECTED A graphic illustration of "unseen" benefits in regard to atomic energy has been expressed by an experienced researcher in this way: I remember a conversation I had with one of our nuclear scientists when I was a member of the Weapons Systems Evaluations Group almost 10 years ago. We were talking about the possible peaceful applications of fission. We really could think of little that could be done with it other than making fissionable material into a form of destructive power. There had been some discussion about harnessing the power of fission, but this seemed to us to be quite remote. It seemed difficult to conceive of the atomic bomb as anything but sheer power used for destructive purposes. Yet today the products of fission applied to peaceful uses are many. The use of isotopes in industry, medicine, agriculture are well known. Food irradiation, nuclear power reactors, now reactors for shipboard use, are with us, and it is hardly the beginning. I frequently ask myself, of late, what 10 years from now will be the commercial, shall we call it, applications of our missile and rocket programs.[2] There are innumerable examples of the way in which invention or discovery, or sometimes just simple human curiosity, result in useful payoff. And frequently no one suspects the direction the payoff finally takes. The point, of course, is that _any_ knowledge eventually pays dividends. The things we learn from our national space program will produce benefits in ways entirely unrelated to missiles or interplanetary travel. (See secs. III and IV.) The reverse is also true; knowledge gained in areas quite remote from outer space can have genuine value for the advance of space exploration. Investigation into the skin of a fish provides a good case in point. A German inventor who migrated to California after World War II had long been interested in ways to reduce the drag of friction produced by air or water on the surface of objects passing through them. One day, while watching a group of porpoises cavort past a speeding ship with the greatest of ease, it occurred to him that the skin of these animals, if closely studied, might shed light on ways of cutting surface friction. It was many years before the inventor was able to enlist the aid of aquarium managers in securing porpoise skins for study. In 1955, however, he obtained the necessary skins and found that dolphins, in fact, owe much of their great speed to a unique skin which markedly reduces the effect of turbulence against it. From this knowledge has come the recent development of a diaphragm-damping fluid surface which has real potential not only for underwater high-speed bodies, such as submarines, torpedoes and underwater missiles, but for any vehicle where fast-moving gases or fluids may cause drag.[3] The implications of this knowledge for satellites near Earth or for reentering spacecraft are obvious. Sometimes a reverse twist in reasoning by a speculative mind will result in enormous practical utility. In Cambridge, Mass., a sanitary engineer teaching at the Massachusetts Institute of Technology began to wonder about the principles of adhesion--why things stick to each other. Do they only stick together because some sticky substance is holding them, or are there other reasons? "If a person is sick," he asked himself, "is it because a cause of sickness is present or because a cause of health is absent? We now know that in infectious diseases the first alternative is true; the patient is ill because he harbors pathogenic germs. The opposite case prevails in deficiency diseases, where necessary vitamins are absent from food and illness is brought about by this absence. To which of the classes does adhesion belong? When we cannot produce a dependable bond, are we dealing with the lack of some adhesive force or with existence of an obstacle to sticking?" Operating on the theory that adhesion might result not only from the presence of a sticky agent but from the removal of all impediments to sticking, this scientist has now managed to produce strong adhesion between the least sticky of substances--polyethylene plastics. He has done it by studying the molecular structure of polyethylenes and removing all impurities which normally find their way into the manufacture of such material. The next step: "We hope to prepare adhesive joints in which a noble gas acts as an adhesive. Noble gases are the least active substances known to chemistry; if they can adhere, it is clear that no specific forces are needed for adhesiveness."[4] No great imagination is required to perceive the meaning which this new knowledge, if proved out, will have for our everyday lives--to say nothing of its usefulness in the making of astronautic equipment. THE ULTIMATE VALUES In any event, it is apparent that where research is concerned--and especially space research with its broad scale of inquiry--we cannot always see the value of scientific endeavor on the basis of its beginning. We cannot always account for what we have purchased with each research dollar. The Government stated this proposition when it first undertook to put the space program on a priority basis: Scientific research has never been amenable to rigorous cost accounting in advance. Nor, for that matter, has exploration of any sort. But if we have learned one lesson, it is that research and exploration have a remarkable way of paying off--quite apart from the fact that they demonstrate that man is alive and insatiably curious. And we all feel richer for knowing what explorers and scientists have learned about the universe in which we live.[5] In this statement there is political support for what the historian, the anthropologist, the psychologist consider to be established fact--that some innate force in the human being makes him _know_, whatever his formal beliefs or whatever his unconscious philosophy, that he _must_ progress. Progress is the core of his destiny. This is a concept which, in connection with space exploration, has been recognized for many years. One of the earliest and most perceptive of the space "buffs" stated it before the British Interplanetary Society in 1946 in these words: "* * * our civilization is no more than the sum of all the dreams that earlier ages have brought to fulfillment. And so it must always be, for if men cease to dream, if they turn their backs upon the wonder of the universe, the story of our race will be coming to an end".[6] [Illustration: FIGURE 2.--In the years immediately ahead, the orbiting observatory or the manned satellite will uncover crucial information about the nature of the universe.] STEERING A MIDDLE ROAD In any endeavor which is as futuristic as space exploration it is not difficult to become lost in the land of the starry-eyed prognosticators. Conversely, it is also easy to find oneself lining up with the debunkers and the champions of the status quo, for their arguments and views give the impression of being hard-headed, sensible. If one must err in either direction, however, it is probably safer, where space is concerned, to err in the direction of the enthusiasts. This is because (and subsequent parts of this report will show it) the Nation cannot afford not to be in the vanguard of the space explorers. Events today move with facility and lightning rapidity. Today, more than ever, time is on the side of the expeditious. We can no longer take the risk of giving much support to the scoffers--to that breed of unimaginative souls who thought Robert Fulton was a fool for harnessing a paddlewheel to a boiler, who thought Henry Ford was a fool for putting an internal combustion engine on wheels, who thought Samuel Langley was a fool for designing a contraption to fly through the air. There are always those who will say it cannot be done. Even in this era of sophisticated flight there have been those who said the sound barrier would never be broken. It was. Others said later that space vehicles would never get through the heat barrier. They have. Now, some say men will never overcome the radiation barrier in space. But we can be sure they will. It is undoubtedly wise for the layman, in terms of the benefits he can expect from the space program in the foreseeable future, to steer a reasonable course between the two extremes. Yet one cannot help remembering that the secret of taking practical energy from the atom, a secret which the human race had been trying to learn for thousands of years, was accomplished in less than a decade from the moment when men first determined that it was possible to split an atom. It is difficult to forget that even after World War II some of our most respected scientists sold short the idea of developing long-range missiles. Impractical, they said; visionary. But 6 years after the United States went to work seriously on missiles, an operational ICBM with a 9,000-mile range was an accomplished fact. THE TIME FOR SPACE All of the glowing predictions being made on behalf of space exploration will not be here tomorrow or the next day. Yet this seems less important than that we recognize the significance of our moment of history. We may think of that moment as a new age--the age of space and the atom--to follow the historic ages of stone, bronze, and iron. We may think of it in terms of theories, of succeeding from those of Copernicus to those of Newton and thence to Freud and now Einstein. We may think of our time as the time of exploiting the new fourth state of matter: plasma, or the ion. Or we may think of it in terms of revolutions, as passing from the industrial cycle of steam through the railroad-steel cycle, through the electricity-automobile cycle, into the burgeoning technological revolution of today. However we think of it, it is a dawning period and one which--in its scope and potential--promises to dwarf much of what has gone before. Those who have given careful thought to the matter are convinced that while some caution is in order, the new era is not one to be approached with timidity, inhibited imagination or too much convention. Neither is there any point in trying to hold off the tempo of this oncoming age or, in any other way, to evade it. Mark Twain once listened to the complaints of an old riverboat pilot who was having trouble making the switch from sail to steam. The old pilot wanted no part of the newfangled steam contraptions. "Maybe so," replied Twain, "but when it's steamboat time, you steam."[7] Today is space time and man is going to explore it. [Illustration: FIGURE 3.--The versatile Atlas can be used either for launching man into space or to carry a nuclear warhead as far as 9,000 miles.] FOOTNOTES: [2] Gavin, Lt. Gen. James M., U.S. Army (retired), speech to the American Rocket Society, New York City, Nov. 19, 1958. [3] Kramer, Max O., "The Dolphins' Secret," New Scientist, May 5, 1960, pp. 1118-1120. [4] Bikerman, Dr. Jacob J., reported in New Scientist, Mar. 3, 1960, p. 535. [5] "Introduction to Outer Space," a statement by the President, the White House, Mar. 26, 1958. [6] Clarke, Arthur C., "The Challenge of the Spaceships," Harper & Bros., New York, 1955, p. 15. [7] Related by T. Keith Glennan, Administrator, National Aeronautics and Space Administration, in an address before the Worcester (Mass.) Economic Club, Feb. 15, 1960. II. NATIONAL SECURITY VALUES There is no longer doubt that space exploration holds genuine significance for the security and well-being of the United States as a nation. It does so in at least three ways. One results from the uses which our Armed Forces can make of the knowledge gained from space exploration. A second results from the influence and prestige which America can exert within the world community because of her prowess in space exploration. A third results from the possibility that space exploration, eventually, may prove so immense and important a challenge that it will channel the prime energies of powerful nations toward its own end and thus reduce the current emphasis on developing means of destruction. The first two values definitely exist. The third seems to be a reasonable hope. THE MILITARY USES From the beginning it has been recognized that space exploration, the research connected therewith, and the ability to operate therein is of more than passing interest to the military. Congress recognized the fact when it passed the National Aeronautics and Space Act of 1958 and directed that "activities peculiar to or primarily associated with the development of weapons systems, military operations, or the defense of the United States * * * shall be the responsibility of, and shall be directed by, the Department of Defense."[8] In the amendments to the Space Act proposed in 1960, this directive was strengthened: "The Department of Defense shall undertake such activities in space, and such research and development connected therewith, as may be necessary for the defense of the United States."[9] It is possible to argue, and indeed it has been argued, that ballistic missiles such as IRBM's and ICBM's are not really "space" weapons, that they are simply an extension of the traditional art of artillery. For the purposes of this report, however, the argument appears to be largely a semantic one. Such missiles do traverse space, they are guided through space, and they employ the same engines and principles which are presently used for purposes of scientific space exploration. While more advanced "space" weapons may evolve in the future, the missile as we know it today cannot very well be divorced from our thinking about space and its practical uses. Going on this assumption, and casting an eye in the direction of the Iron Curtain, it is obvious that the Soviet Union is going all-out to exploit space for military purposes. Military men have known for years that the tremendously powerful booster which the Soviets have been using to launch their massive sputniks was originally designed to carry the primitive heavy version of the A-bomb across continents. If there was ever doubt of the extent to which the Soviets intend to make space a selected medium for military purposes it was erased when Premier Khrushchev made his address to the Supreme Soviet early in 1960. He commented in part: Our state has at its disposal powerful rocket equipment. The military air force and navy have lost their previous importance in view of the modern development of military equipment. This type of armament is not being reduced but replaced. Almost the entire military air force is being replaced by rocket equipment. We have by now sharply cut, and it seems will continue sharply to cut and even discontinue the manufacture of bombers and other obsolete equipment. In the navy, the submarine fleet assumes great importance, while surface ships can no longer play the part they once did. In our country the armed forces have been to a considerable extent transferred to rocket and nuclear arms. These arms are being perfected and will continue to be perfected until they are banned.[10] While it is difficult to assess the actual extent of the Soviet preoccupation with missiles, it has been reported that the Russians are building upward of 100 IRBM and ICBM bases to be manned by about 200,000 men. Most of these, at least the intermediate range bases, are said to be along Russia's Baltic coast, in East Germany, in the southern Ukraine and in the Carpathian Mountains.[11] In any event, the space age is clearly "here" so far as the military are concerned, and U.S. forces--particularly since the development of the much lighter atomic warheads--have been likewise diligent in their space efforts. This is because many military minds are now agreed that: We are moving inevitably into a time of astropower. We face a threat beyond imagination, should events ever lead to open conflict in a world of hypersonic velocities and a raging atom chained as our slave. We must be strong, we must be able to change to meet change. What may come against our beloved America will not be signaled by one light from the North Church steeple, if they come by land, or two, if they come by sea. Never again. They will come through space, and their light of warning will be the blinding terror of a thermonuclear fireball.[12] It is important to note, in connection with military matters, that pure rocket power, is not the only avenue to success in space use. The American Atlas missile, for example, which can carry a nuclear warhead and which operates on considerably less thrust than the powerful Soviet boosters thus far demonstrated, has nevertheless shown the capability of negotiating a 9,000-mile trek and landing in the target area. This is about 1,500 miles farther than any Soviet shots revealed to the public in the 2-1/2-year period following the first sputnik. It is also a sufficient range to permit reaching almost any likely target on the globe. From the military point of view, the meaning thus brought out is that sophistication of missiles together with reliability and ease of handling is more important than pure power. When we begin to consider both the civil and military aspects of space use in the decades ahead, however, rocket power acquires fresh importance. It is, as one expert says, "the key to space supremacy."[13] Not only is much heavier thrust required for ventures farther out into space, but probably thrust developed by different means as well, such as atom, ion, or even photon power. This suggests the possibilities of weapons which today are considered to be "way out" or "blue sky"--in short, farfetched. Yet they include the ideas of men with solid scientific training as well as vision. For example, Germany's great rocket pioneer, Prof. Hermann Oberth, "has proposed that a giant mirror in space (some 60 miles in diameter) could be used militarily to burn an enemy country on Earth. For peaceful purposes, however, such a space mirror could be used to melt icebergs and alter temperatures."[14] Another reputable German scientist who has been working for a number of years on photon (electromagnetic ray) power as a source of propulsion, declares that if such power is possible so is "the idea of a 'death ray,' a weapon beam which burns or melts targets, such as enemy missiles, on which it is trained. The idea has been familiar in science fiction for a long time and has been scorned often enough. Yet, if the photon rocket is possible so is the ray gun."[15] Still another proposal, one made to the Congress, involves use of the Moon as a military base. "It could, at some future date, be used as a secure base to deter aggression. Lunar launching sites, perhaps located on the far side of the Moon, which could never be viewed directly from the Earth, could launch missiles earthward. They could be guided accurately during flight and to impact, and thus might serve peaceful ends by deterring any would-be aggressor."[16] In spite of the fact that ideas such as these are being sponsored by competent and responsible scientists, other scientists equally competent and responsible sometimes cry them down as impractical, impossible or even childish. One engineer, for instance, describes maneuverable manned space vehicles as having "no military value," bases on the Moon as having no military or communications use, and the idea of high velocity photon-power for space travel as "a fantasy strictly for immature science fiction." He also characterizes the reconnaissance satellite, which U.S. military authorities have long since programmed and even launched, as being "definitely submarginal * * *. A fraction of the cost of a reconnaissance satellite could accomplish wonders in conventional information gathering."[17] Controversies such as these are difficult for the person who is neither a scientist nor a military expert to judge. One is inclined to recall, though, the treatment received by General Billy Mitchell for his devotion to nonconventional bombing concepts; the fact that the utility of the rocket as developed by America's pioneer, Dr. Robert H. Goddard, was generally ignored during World War II; the fact that it took a personal letter from Albert Einstein to President Roosevelt to get the Manhattan Project underway. Yet today the bomber, the missile, and the nuclear weapon form the backbone of our military posture. In other words, history seems to support the proposition that no matter how remote or unlikely new discoveries and approaches may first appear, the military eventually finds a way to use them. Will it be any different with space exploration? OUR POSITION IN THE INTERNATIONAL COMMUNITY Like the military values of space research, the practical value of space exploration in terms of world prestige has also been acknowledged almost from the beginning of the satellite era. The White House, in its initial statement on the national space program, declared: It is useful to distinguish among (the) factors which give importance, urgency, and inevitability to the advancement of space technology (one of which) is the factor of national prestige. To be strong and bold in space technology will enhance the prestige of the United States among the peoples of the world and create added confidence in our scientific, technological, industrial, and military strength.[18] Only recently, however, has the full impact and meaning of this phase of our national space program come to be widely recognized. It has been stated, perhaps in its most forceful and succinct form, by an American official in a unique position to know. The Director of the U.S. Information Agency, part of whose job is to keep track of the esteem in which America is held abroad, has told Congress: Our space program may be considered as a measure of our vitality and our ability to compete with a formidable rival and as a criterion of our ability to maintain technological eminence worthy of emulation by other peoples.[19] This element of space exploration takes on particular significance in light of the current international struggle to influence the minds of men, in light of the rising tide of nationalism throughout the world, and in light of the intensification of the cold war as demonstrated by the now-famous U-2 incident and the hardening attitude of oriental communism. In the words of an influential newspaper: Wholly apart from the intellectual compulsions that now drive man to move higher and higher into the high heavens, it seems clear that our country can be niggardly in this field only at the risk of being completely and forever outclassed by Russia--a gamble that could have the most fearful political, economic, and military consequences.[20] Incidentally, there is another prestige factor to be considered. This is what might be called the chain-reaction factor: the likelihood that technological preeminence in the space field will attract top talent from other parts of the world to the banner of the country which develops it, and thus constantly nourish and replenish the efforts of that country. It is a consideration which has not received general attention, although it has been discussed before some of the world's leading space scientists.[21] Here again, as with the military situation, the Soviets are making every effort to exploit their dexterity in space. They are pursuing the prestige gambit directly and indirectly. In the first category, for example, they give top priority to space exhibits in important public forums--as their duplicate sputniks strategically placed at the world's fair and the United Nations attest. Premier Khrushchev's delight in making gifts to foreigners of miniature Soviet pennants similar to that carried in Lunik II--which hit the Moon--is another instance.[22] The indirect drive for prestige via space technology is far more important. It has been described by a congressional committee as follows: It is difficult to escape the conclusion that the Soviet Union in the last several years has demonstrated a great skill in coordinating its progress in missilery, its success in space missions, and its foreign policy and world image. Shots seem to have been timed to maximize the effects of visits of Soviet leaders and to punctuate Soviet statements and positions in international negotiations. This is not to equate their space activities with hollow propaganda. Empty claims do not have a positive effect for long. Nor is there any firm evidence that it has been possible for political policymakers to call their shots at times inconsistent with good scientific and technical needs. The conclusion is rather that the many elements of scientific, technical, military, political, and psychological policy are all weighed, and tests which make a full contribution to such a combined strategy are carried out and supported with appropriate publicity.[23] There is also evidence that scientific endeavor by the Russians for prestige purposes is having repercussions on internal policy. Great emphasis is currently being placed on the demonstrable usefulness of scientific effort--to the extent that Soviet colleges, research institutions, examining boards, and academies of science have been directed to be more exacting in conferring scientific degrees and titles. Newness and usefulness are requisite, but, at the same time, degrees may now be awarded for other than dissertations; inventions and textbooks of major importance may also earn a degree for their authors.[24] Within the prestige context, it is true that the United States must labor under certain handicaps because of the nature of its democratic system. No effort is made in the American space program to hide the failures which result from its highly complex character. Our burnups, misfires, explosions, fizzles, and lost or wayward vehicles are well publicized. Those of the Soviet Union rarely are. Even though most nations are well aware that the Russians must be having their troubles, too, the appearance of uniform success fostered by the U.S.S.R. inevitably contributes to an image of scientific superiority. In addition, the Soviets have developed a habit of striving for spectacular "firsts," most of which undoubtedly are undertaken almost as much for prestige reasons as for scientific ones. [Illustration: FIGURE 4.--Symbolic of the American effort in space is this Thor-Able rocket, shown here launching the Tiros weather satellite into a near-perfect orbit. This same vehicle, which launched the record-breaking 23 million-mile communication probe--Pioneer V--has contributed enormously to U.S. prestige abroad.] Still, the United States has not done badly from the prestige angle. So far as the world's scientific fraternity is concerned, it may even be well in the lead. In the first 30 or so months following the opening of the space age, as signaled by the launching of Sputnik I in October 1957, the United States put 21 satellites into orbit out of 42 attempts. Two out of five deep-space probes were successful. The degree of success for all major launchings ran better than 50 percent. The American effort has been based on a broad scope of inquiry and includes long-range communications, weather reporting, navigation and surveillance vehicles, as well as information-gathering satellites. During the same period the Soviets launched four Earth satellites, one deep-space probe, one lunar-impact probe and one satellite into a much elongated Earth orbit which circled and photographed the Moon. Most of their vehicles have been substantially heavier than those launched by the United States, although complete information on their scientific purposes and the result obtained has never been disclosed. The world political value of such programs cannot be discounted. To the extent that the welfare of the United States depends upon its stature in the eyes of the rest of the world (which is believed considerable) and to the extent that the scientific capability of the United States influences such stature (which is also believed considerable) our space venture has very marked practical utility. It may even mean the difference between freedom and dictatorship, between survival and oblivion. SPACE AS A SUBSTITUTE FOR WAR A natural outgrowth of the military and prestige facets of space exploration is the question of whether this activity, in time, will replace the forces which have historically driven nations into armed conflict. Any number of social scientists and historians have speculated that this might occur. The theory is that the conquest of space may prove to be the moral equivalent of war by substituting for certain material and psychological needs usually supplied through war; that the absorption of energies, resources, imagination, and aggressiveness in pursuit of the space adventure may become an effective way of maintaining peace. Put another way, nations might become "extroverted" to the point where their urge to overcome the unknown would dwarf their historic desires for power, wealth, and recognition--attributes which have so often led to war in the past. The fact that the United Nations, late in 1959, agreed to set up a permanent Committee on the Peaceful Uses of Outer Space attests to the hopes and potential of such a development. Of course, whether this condition will actually develop is anybody's guess. But in a world where brute force is becoming increasingly dangerous and catastrophic, the bare possibility of such a result should not be ignored by those who may be contemplating the values of space exploration. It could be the highest value of them all. [Illustration: FIGURE 5.--Today's assembly lines for automobiles and aircraft are being supplemented by the growing astronautics industry, here shown turning out capsules for manned space flight.] FOOTNOTES: [8] Public Law 85-568, 85th Cong. [9] H. Rept. 1633, 86th Cong., 2d sess., p. 6. [10] Speech to the Supreme Soviet, Jan. 14, 1960. [11] Associated Press dispatch, dateline London, Dec. 2, 1959. [12] Scott, Brig. Gen. Robert L., USAF (retired), Space Age, February 1959, p. 63. [13] Ostrander, Maj. Gen. Don R., USAF, before the American Rocket Society, Los Angeles, May 10, 1960. [14] Cox, Donald and Stoiko, Michael, Spacepower, John C. Winston Co., Philadelphia, 1958, p. 16. [15] Saenger, Dr. Eugen, New Scientist, Sept. 10, 1959, p. 383. [16] Boushey, Brig. Gen. H. A., USAF, Hearings before the House Select Committee on Astronautics and Space Exploration, Apr. 23, 1958. [17] Pierce, Dr. J. R., "The Dream World of Space," Industrial Research, December 1959, p. 58. [18] 5 supra. [19] Allen, George V, testimony before the House Committee on Science and Astronautics, Jan. 22, 1960. [20] Editorial in the Washington Evening Star, Apr. 4, 1960. [21] Remarks of Hon. Aubrey Jones, Minister of Supply, to the International Astronautical Federation, London, Sept. 1, 1959. [22] Associated Press dispatch, dateline Rangoon, Feb. 18, 1960. [23] "Space, Missiles, and the Nation," report of the House Committee on Science and Astronautics, May 18, 1960, p. 53. [24] The New Scientist, Mar. 3, 1960, p. 547. III. THE ECONOMIC VALUES We in the United States believe that we have the world's highest standard of living. Our current wealth, prosperity, consumer goods and gross national product are at a peak hitherto unreached by any country. Nevertheless, economists who see the steady preponderant outflow of goods and capital from the United States and who study the rising rate of economic capability in other countries can find little room for complacence in the present status of things. They are also well aware of the Soviet Union's announced intent of beating the United States at its own game: economic expansion. Military historians are likewise aware that even strong economies, when they become static, do not guarantee safety. On the contrary, they seem likely to induce a dangerous national apathy. This syndrome is familiar in history. Carthage suffered from it. Carthage enjoyed enormous prosperity and was flourishing when she was destroyed by her Roman competitor. Much later, Rome had a gross national product without precedence. Her wealth and splendor were unsurpassed when the Vandals and Visigoths began their onslaughts. Neither Rome's great engineering skills, its architectural grandeur, its great laws, nor, in the last analysis, its gross national product, could prevail against the barbarians. Their GNP was negligible; nevertheless they ransacked the mighty Roman Empire. The gross national product is no insurance of survival. It is not a sign of military strength, and indeed, it may not even be sufficient for the economic battle.[25] Thus from the point of view of economic stimulus and continued commercial dynamism, space exploration should be--and is proving to be--a godsend. U.S. EXPENDITURES ON SPACE It is impossible to arrive at accurate figures which might help indicate the extent of this effort in dollars and cents. But we do know that the U.S. Government is presently putting about $3.5 billion annually into the research and development phases. How much more may be going into the purchase of completed space hardware is difficult to say; certainly it is a higher figure still. The National Aeronautics and Space Administration, in presenting its 10-year plan to Congress recently, indicated that this agency alone expects to average between $1.5 and $2 billion a year during the next decade. The amount of effort going into space-related programs on the part of private industry, measured in dollars, again can only be roughly estimated. But it is a sizable figure and is known to be growing. It may amount to half the governmental research and development outlay. These figures add up to a very important segment of the national economy, and the fact that they represent a highly active and progressive segment is particularly heartening to the economic experts of the Nation. THE SPREAD OF ECONOMIC BENEFITS One of the most useful characteristics of the space program is that its needs "spread across the entire industrial spectrum--electronics, metals, fuels, ceramics, machinery, plastics, instruments, textiles, thermals, cryogenics, and a thousand other areas."[26] The benefits from space exploration thus have a way of filtering into almost every area of the American economy, either directly or indirectly. "Perhaps the greatest economic treasure is the advanced technology required for more and more difficult space missions. This new technology is advancing at a meteoric rate. Its benefits are spreading throughout our whole industrial and economic system."[27] A graphic example of the manner in which the technological and economic benefits from the space program can grow may be seen from the development of the X-15. This rocket craft, designed to "fly" beyond the Earth's atmosphere at altitudes up to 100 miles, is the product of 400 different firms and contractors. Inasmuch as other nations, those which generally have lagged behind the United States in technical know-how, are now rapidly bringing their technology up to date--this windfall from our space program is especially opportune. It is providing the incentive to American industry to remain in the world's technological van. And it is emphasizing that economic leadership is a dynamic thing, that U.S. mass-production techniques which have enabled the Nation to compete so well in foreign markets are no longer, of themselves, sufficient guarantee of superior economic position. While America's space exploration program, on a formal basis, came into being as recently as October 1958, its impact on the national economy has probably been sharper than that of any single new program ever conceived. For there are now at least 5,000 companies or research organizations engaged in the missile-space industry. And more than 3,200 different space-related products have been required and are being produced to date.[28] One can only speculate on the economic effect which the space program is having on investments or on investors who have no other connection with it. It seems significant, however, that the stock market pages in recent months have come to devote a good deal of attention to "space issues." Financially speaking, space has thus become a major category. That it has done so in such a short period would seem to have marked implications for the future. In brief, space exploration is becoming almost an industry in itself, and there are those who believe it destined to become the largest industrial spur in the Nation before too many years have gone by. One expert, an experienced hand not only in astronautics but in the business world as well, describes the outlook in this fashion: "A great industrial change is taking place in the United States. The aircraft industry, which long considered missiles as a small department, now finds itself becoming a part of the large missile and space flight industry. It is an elemental evolution. An industrial change is upon us comparable to the advent of mercantilism."[29] He has predicted that within a decade or so the astronautics industry will be larger than the automotive industry of the entire world. While such predictions may be overly optimistic, they can scarcely be dismissed as irresponsible in the light of what has already happened. [Illustration: FIGURE 6.--Booster engines of tomorrow, such as this mockup of the 1,500,000 pound thrust single engine, will place broad requirements on men and materials.] CREATION OF NEW INDUSTRIES Whether or not we think of the missile-space business as being a self-contained industry, the requirements and exigencies of space exploration can be expected to result in the creation of new or greatly strengthened industrial branches, for example: _Research_ This phase of the American economy is having a phenomenal growth. Not only have many established industries now placed research high on their organizational charts, but hundreds, perhaps thousands, of new businesses are springing up which are entirely devoted to research and development. R. & D., as it is called, is their stock in trade, their only product. And space exploration appears to have given them their greatest boost. One recent study on the subject regards research as the fourth major industrial revolution to take place in American history, following the advents of steam mechanization, steel, electricity-and-internal combustion engines. The fourth industrial revolution, ours, is unique in the number of people working on it, its complexity, and its power to push the economy at a rate previously impossible. Today between 5,000 and 50,000 _technical entrepreneurs_ (top R. & D. engineers, leading scientists, and highly effective technical managers) are directly analogous to an estimated 50 to 500 men in all of the first three periods. Thus about 100 times the effort in terms of qualitative (effective, creative, patent-producing) manpower is being spent on the fourth revolution as on the other three combined. Total manpower, of course, is much more than that: there are probably 700,000 engineers and industrially oriented scientists in the United States today, as against 2,000 even as late as Edison's first high voltage light bulb. Whereas Edison worked with 20 to 100 scientists in his laboratory, and Fulton labored alone, there are 5,000 industrial laboratories today employing from 20 to 7,300 technical men each.[30] _New power sources_ One of the greatest demands of spacecraft of the future will be for new sources of power. While rocket propulsion power is part of this picture, the power needed to operate space vehicles after launching may prove to be the larger and more important need. Progress has already been made in this direction by use of special kinds of batteries and solar cells which convert the sun's rays into electric current. But these will need supplementing or replacing eventually as greater power becomes necessary. It would be rash to predict the outcome of this complicated field, but certain very promising methods can be listed. One is the fuel cell, which converts fuel directly into electric power without the necessity for machinery or working parts. Much progress has been made on the fuel cell in recent months. In England a 40-cell unit has been used to drive a forklift truck and to do electric welding. It develops up to 5 kilowatts.[31] In the United States a 30-cell portable powerplant developing 200 watts has been delivered to the Army and Marine Corps,[32] while a 1,000-unit cell has been developed in the Midwest which provides 15 kilowatts and drives a tractor.[33] Another method is plasma power, or power generated through the use of hot ionized gas. Such gas acts as a conductor of electricity and when employed as a "magnetohydrodynamics" generator it can be used for a variety of purposes. It has the advantage of being simple, rugged, and efficient. Some day it may also prove very economical. Already 10 municipal areas along the Mason-Dixon line are preparing to experiment with electric power derived from this source.[34] It has been estimated that "as much as 1 million watts could be generated by shooting a stream of plasma at speeds three times that of sound through a magnetic field only 3 feet long and with the magnetic poles 6 inches apart."[35] [Illustration: FIGURE 7.--The possible power source for space ships of the future, the ion jet, has significant counterpart uses for the commercial world.] Another possible source is photoelectric power. While a number of very difficult problems block the practical generation of this kind of power, the astronautics research division of one American company has now succeeded in increasing the efficiency of photoelectric cells by a factor of more than 300.[36] So the possibilities in this area are looking up. As discussed in section II, photon power derived from the ejection of electromagnetic rays may someday prove a source for accelerating vehicles once they have escaped from Earth's gravity. Another possibility, of course, is atomic energy about which much has been said and written. If, as some scientists believe, extensive space exploration by manned crews will depend on harnessing this great source of energy--both for booster purposes and for operating spacecraft in the distant parts of our interplanetary system--this fact alone may assure that the obstacles to practical nuclear energy are overcome faster and more completely than would otherwise be the case. It is interesting to note that the science of controlling nuclear fusion (as opposed to fission) has come so far in the past several years that 11 private power companies are pooling their resources to advance this state of the art.[37] _New water sources and uses_ A look into the future indicates very strongly that water will become a major world problem, possibly by the beginning of the 1970's, which is likely to be another "dry" decade. Present water supplies, coupled with the increasing population and the many new uses for water, are barely adequate now. In another 10 years the situation could be critical. Part of our national space program includes studies on how to use and reuse water to the best advantage of the human in space. A number of avenues are being followed, including vaporization of volatiles in biological wastes.[38] From research of this kind it is more than possible that knowledge will evolve which will prove useful in the practical production of fresh water from other chemical compounds or mixtures, including seawater. More than that, it could lead to new ways for extracting much needed materials from the sea. Seawater contains 40 basic elements, 19 in relatively copious amounts. These elements run from 18,980 parts parts per million of chlorine to 0,0000002 part per billion of radium. Yet, so far, we have learned to extract only bromine and magnesium in useful amounts.[39] Conversely, the study of how marine animals extract rare elements from the seawater, such as the extraction of copper compounds by the octopus, could provide astronautic researchers with important clues for keeping man alive in space. _Noise and human engineering_ This is a field in which research has been going on seriously for only a few years. Most of it has developed since World War II. Human engineering is involved primarily with the reaction of people to their immediate surroundings and how to arrange those surroundings in order to permit the most comfortable and efficient functioning within them. The noise aspect of human engineering, as it may develop from the problems of astronauts operating in a silent world, could lead to a variety of innovations for improving the performance of workers or even the general attitude of people living in urban areas. In today's world, where humans are subjected to so many different kinds, degrees, and sources of noise, psychologists consider the matter to be of no small importance. _High speed-light weight computers_ Space vehicles now need electronic computers for determining the moment of launch, for fixing orbits, for navigation, and for processing collected data. Computers will precede man into space. They will take over guidance and decision functions beyond limits of human physiology, psychology, versatility, and reaction time.[40] The trend in this direction is marked and space exploration is accelerating it. Because of weight and size limitations, and due to the genius of research, the giant electronic brain of today will soon disappear and be replaced with an apparatus only a small fraction of its present size. The implications for the business and professional world are great. And a not inconsiderable side effect, according to many modern technicians, will be the flood of brainpower released from time-consuming chores and thus made available for more basic, creative thought. [Illustration: FIGURE 8.--The needs of tomorrow's spacemen will lead to marked advances in human engineering and psychology.] _Solid state physics_ Few areas of effort are advancing this extremely promising art faster than space exploration, which places a premium on light weight and small size. The miniaturization of equipment being placed in U.S. satellites, for example, has been one of the contemporary wonders of the world of science. A big part of this march toward tiny equipment is in the field of electronics, where the process is called microminiaturization, molecular electronics, micromodular engineering or a number of other terms. In essence it refers to the greatly reduced size of equipment through "integrated circuits," coupled functions, the building of complicated components into a single molecular design and so on. The art has proceeded to the point where complete radios can be reduced to the size of a lump of sugar. Clearly, this trend holds almost unlimited utility for the home, the factory, the marketplace, the highway, the hospital or just about any other arena one cares to name. So great is the promise that virtually every electronics company in the country is undertaking "to take the state of the art into fundamentally new areas" and there exploit its many possibilities.[41] ECONOMIC ALLIANCES It may be that our national space exploration program will also result in stronger economic alliances, not only within our own national borders but on an international basis. Interesting speculation to this effect has been advanced by a prominent official of the National Aeronautics and Space Administration: I think we may expect that the combined influence of jet aircraft and satellite communications systems will enable us to integrate the now somewhat distant States of Hawaii and Alaska with the rest of the States as thoroughly as the East and West are already integrated. Second, and in many ways a more intriguing possibility, is the prospect of developing a truly international economic organization. It is quite apparent that even today a large fraction of the economy of the United States is dependent upon foreign trade. Some nations of the world, such as England or Japan, are almost entirely dependent upon foreign trade for their basic standard of living; however, current foreign trade practices are necessarily based on a somewhat leisurely pattern enforced by our current communications capacity. Whether we will be able to increase the efficiency and effectiveness of our activities in foreign trade through the use of the new communications facilities now foreseen will of course depend upon our political ability to work out viable arrangements for our mutual benefit with our oversea friends. One of the lessons of history in the fields of communications is that an increase in capability has never gone unused. The capability of doing new things has always resulted in it being found profitable to use this capability in all fields, both commercial and governmental.[42] PRIVATE ENTERPRISE IN SPACE Up to now space exploration has been more or less the exclusive domain of the Federal Government. It seems likely that this situation will not change much in the near future. But the question finally arises: Is the nature of space such that the traditional American concept of private enterprise can have no place in it? On this score there is debate. Recently, however, there have been indications that businessmen feel they will be able to conduct certain business operations and services in space. The space frontier will inevitably increase the scale of thinking and risk taking by business. When we are dealing with space, we are dealing with a technology that requires a planetary scale to stage it; decades of time to develop it; and much bigger investments to get across the threshold of economic return than is customary in business today. Business must now think in international terms, and in terms of the next business generation. It must step up to the big risks with the same vision that enabled an earlier generation of builders to push railroad tracks out across the wilderness and lay the foundations of our modern economy.[43] Incidentally, it should be pointed out that space exploration is already encouraging the formation of business of all sizes. Myriads of small businesses have sprung up, many of them "suppliers of specialty equipment for the larger concerns that have responsibility for major components and systems."[44] To what extent will private enterprise become involved? Here is one view: As the years pass by, and space apparatus becomes more reliable, and the work of obtaining scientific data from space acquires a more routine character--certainly many of the necessary operating facilities could be put on a self-liquidating, private-industry basis. Probably the first opportunities for private investment will come in the commercial use of satellites. Looking even further into the future of space exploration, perhaps there would be economic justification for a privately owned launching service that would put objects into space for the peaceful purposes of friendly governments, international agencies, industry, and the universities. The base itself, from which the commercial launching service would operate, might be modeled after a port authority. Such a nonmilitary, international space port could develop as a center for many private enterprises related to space operations. These might include service and maintenance facilities; data-processing services; space communication centers; laboratory facilities; standardized equipment for satellites and other space vehicles; fuel supplies; medical services; biological services; and general supplies. Moving away from the idea of a commercial space port, must all future tracking stations, observatories, and data-processing stations be Government owned? How about experimental stations for the simulation of space environments? How about laboratories and stations actually constructed in space? Or will privately owned facilities one day offer these services on an international basis to governments, industries, universities, and international agencies? Most likely the first businesses suitable for commercial operation, using space technologies, will be worldwide communication by satellite, private weather forecasting, and high-speed Earth transport by rocket.[45] [Illustration: FIGURE 9.--The electric and electronic needs of the space program are requiring more and more skilled labor.] JOBS There probably is no reliable way to gage the number of Americans who are employed today because of the national space effort, nor to estimate accurately the number who are likely to be employed in the years ahead. This much can be said, though. They already number in the tens of thousands, probably in the hundreds of thousands. The Administrator of the National Aeronautics and Space Administration has reported that his agency presently employs 18,000 persons. And he adds "in spite of the size of this organization, we estimate that approximately 75 percent of our budget will be expended through contracts with industry, educational institutions, and other nongovernmental groups." Thus the number of persons privately employed who are working on NASA projects is, of itself, a high figure. The number employed in, by, or for the Department of Defense on missiles or space-related projects is undoubtedly higher. In addition to these must be added the men and women employed by private industry in a capacity not directly related to the space program but whose jobs have been created nonetheless by its stimulus. The fact is that the military and peaceful needs of the space program are already employing a significant percentage of the industrial work force, and will make up an even larger proportion of total employment and production of the country as the years go by. The aircraft industry, for example, is broadening its scope to include missile and space technologies. Much of the electronics industry is devoted to missile and space needs. The communications, chemical, and metallurgical industries are increasingly involved. These industries are already among the largest employers in the United States, and they are the major employers of the Nation's technical manpower. Hence we are not speaking of a minor element in the national economy, but of its leading growth industries.[46] This phase of the space program's value should not be eyed merely from the standpoint of scientists and the labor market. It has major significance for the professions--for doctors, lawyers, architects, teachers, and engineers. All of these will be vitally concerned with space exploration in the future. The doctor with space medicine and its results; the lawyer with business relations and a vastly increased need for knowledge in international law; the architect with the construction of spaceports and data and tracking facilities; the teacher with the booming demand for new types of space-engendered curricula. As for the engineer-- In this pyramid of scientific and engineering effort there will be found requirements for the services of almost every type of scientist and engineer to a greater or less degree. In the forefront, of course, are the aerospace and astronautical engineers but the development of the Saturn launching vehicle has also enlisted the cooperation of civil, mechanical, electrical, metallurgical, chemical, automotive, structural, radio, and electronics engineers. Much of their work relates to ground handling equipment, special automotive and barge equipment, checkout equipment, and all the other devices needed to support the design, construction, testing, launching, and data gathering.[47] AUTOMATION AND DISARMAMENT Finally, an economic value of extreme importance could be the ultimate role of the space program in modifying the threat to labor which is inherent in automation and disarmament. Space exploration, opening up new and profitable vistas, could take up much of the slack thus imposed and do it at a higher and more intellectual job level. Automation, as we know, is already in the process. In agriculture alone it has bitten deeply into the laboring force and yet produces greater crops than ever.[48] It is gathering strength in many other fields. Disarmament is a long way from being a reality. But all nations of the world are striving for it, or at least giving lipservice to its principles, so it may one day emerge as a reality. If this happens, space exploration again may be a most important element in taking up the slack which a prominent reduction in defense activity could not help but bring about. Indeed, there are some who already foresee a complete substitution of space for defense, and who prognosticate that in the 1990's "the economy of nations is now based on the astronautics industry, instead of war."[49] Certainly, some new economic force would be crucial to nations deprived of the need for devising and manufacturing weapons. [Illustration: FIGURE 10.--A host of new materials, skills, and engineering techniques are bound up in the construction of rocket engines such as this first stage booster.] FOOTNOTES: [25] Gavin, James M., address to the International Bankers Association, Bal Harbour, Fla., Dec. 2, 1958. [26] Mitchell, Hon. Erwin, in the House of Representatives, June 2, 1960. [27] Dryden, Dr. Hugh L., Deputy Administrator, NASA, Penrose lecture before the American Philosophical Society, Philadelphia, Apr. 21, 1960. [28] Missile-Space Directory, Missiles and Rockets, May 30, 1960, pp. 86-359. [29] Haley, Andrew G., general counsel and past president of the International Astronautical Federation, "Rocketry and Space Exploration." Van Nostrand Co., Princeton, N.J., 1958 p. 156. [30] Ruzic, Neil P., "The Technical Entrepreneur," Industrial Research, May 1980, p.10. [31] Bacon, F. T., "The Fuel Cell, Power Source of the Future," New Scientist, Aug. 17, 1959, p.272. [32] Science Service dispatch, dateline Lynn, Mass., Apr. 25, 1950. [33] Sharp, James M., "The Application of Fuel Cells in the Natural Gas Industry," Southwest Research Institute, San Antonio, Tex., Mar. 4, 1960, pp. 2-3. [34] Lear, John, "Towns To Be Lit by Plasma," New Scientist, Nov. 19, 1959, p. 1006. [35] Pursglove S. David, Industrial Research, March 1950 p. 19. [36] Ibid. [37] Ibid., p. 18. [38] Space Business Daily, June 13, 1960. [39] Cox, Dr. R. A., "The Chemistry of Seawater," New Scientist, Sept. 24, 19459, p. 518. [40] Hines, L. J., Space Age News, Apr. 25, 1960, p. 4. [41] Gaertner, W. W., "Functional Microelectronics," Missile Design and Development, March 1960, p. 34. [42] Stewart, Dr. Homer J., address to the American Bar Association, Miami Beach, Aug. 25, 1959. [43] Cordiner, Ralph J., "Competitive Private Enterprise in Space," lecture at U.C.L.A., May 4, 1960 [44] Ibid. [45] Ibid. [46] Ibid. [47] 27 supra. [48] See "The Problem of Plenty," U.S. News & World Report, Apr. 13, 1959, p. 97. [49] Markuwitz, Meyer M., and Gentieu, Norman P., "The Rocket, A Past and Future History," Industrial Research, December 1959, p. 78. IV. VALUES FOR EVERYDAY LIVING The so-called side effects of the space exploration program are showing a remarkable ability to produce innovations which, in turn, improve the quality of everyday work and everyday living throughout the United States. In setting forth specific ways and means in which the space program is producing practical uses, it must be kept in mind that no attempt is made here to separate uses resulting from the civil phases of the program from those developed by the military phases. Inasmuch as the two are closely intertwined, it would seem impractical to do so. And, in instances where the same or similar research is being conducted by a single contractor on behalf of both phases, it is usually impossible to do so. TECHNOLOGICAL BENEFITS This category of the practical uses of the space program is impressive indeed. Most of us are familiar with the plans which the United States has for using artificial satellites in ways which will be beneficial to all mankind. These include the satellite used for worldwide communications, for global television, for quick and accurate navigation, and for much improved weather prediction and weather understanding. Here, however, is a summary of space-related developments about which the American public has heard considerably less: First, there is the high-speed computer. Developed initially to meet military demands for faster calculation, the computer is an integral part of American industry, making it possible to do many operations with a high degree of efficiency and accuracy. Thermoelectric devices for heating and cooling, now adapted for commercial applications, were originally designed to provide energy sources for space vehicles. The glass industry, as a result of work done during and after the Second World War on lenses and plastics, promises substantial gains in the consumer fields of optics and foods. Pyroceram, developed for missile radomes, is now being used in the manufacture of pots and pans. Materials suitable for use in the nuclear preservation of food may make us even better fed than we already are. Medical research, and our health problems, can use such things as film resistance thermometers. Electronic equipment capable of measuring low-level electrical signals is being adapted to measure body temperature and blood flow. In a dramatic breakthrough, illustrating the unexpected benefits of research, it has been found that a derivative of hydrazine, developed as a liquid missile propellant, is useful in treating certain mental illnesses and tuberculosis. Of course, the aeronautics industry has benefited tremendously. Engines, automatic pilots, radar systems, flight equipment, capable of meeting the high standards required by space vehicles represent a great improvement over our already excellent aircraft. A plasma arc torch (has been) developed for fabricating ultrahard materials and coatings by mass production methods. The torch, an outgrowth of plasma technology, develops heats of 30,000 degrees and can work within tolerances of two-thousandths of an inch. Another application from the missile field, which shows real possibilities, is a reliable flow meter that has no packings or bearings. This was first developed for measuring liquefied gases and should have a very wide industrial usefulness. It may even lead to improvements in marine devices for measuring distance and velocity. Ground-to-air missiles that ride a beam to their targets must measure the distance to the target plane with an accuracy of a few feet in several miles. This principle, now being applied to surveying techniques, has revolutionized the surveying industry. The solenoid valve, which seats itself softly enough to eliminate vibration, has been applied very satisfactorily to home-heating systems. The use of the jet drilling for mining is another, and worthy of amplification. Missiles are already working the economically unminable taconite ore of the Mesabi Range, have helped build the St. Lawrence Seaway, and are bringing down costs in quarrying. It is estimated that taconite will be supplying about a third of our ores in less than 20 years. Until 1947 we were unable to mine this very hard rock, and then suitable rotary and churn drills were produced. Jet drilling, now available, cracks and crumbles stone layers by thermally induced expansion and is somewhere between 3 and 5 times faster than rotaries. Jet piercing can take us far deeper into the earth than we have been able to go so far, to new sources of ore and hydrocarbons. In stone quarrying, jet spalling and channeling are proven techniques. Stone quarrying has been expensive and wasteful heretofore. Rocket flame equipment allows cutting along the natural cleavage planes, or crystal boundaries--hence cuts stone thin without danger of cracking and, in addition, produces a fine finish that cannot be obtained when cutting by steel or abrasive tools. Scientific literature is beginning to contain speculations on using the principle of the missile engine to save unstable intermediate products of the chemical processes. The high heats achieved in the rocket engine can, perhaps, be utilized to produce desired products that would be lost by slow cooling. But the high rate of cooling accomplished by expanding gases through the engine nozzle, it is thought, would save these unstable compounds. Infrared has come into its own through missile electronics. Infrared--since it cannot be jammed--appears to be challenging radar for use in guidance devices, tracking systems, and reconnaissance vehicles. Infrared is being used industrially to measure the compositions of fluids in complex processes of chemical petroleum refining and distilling. Infrared cameras are used in analyzing metallurgical material processing operations, to aid in accuracy and quality control. The entire infrared field should be significantly assisted in its growth and application through our missile-space programs. Another very promising outcome from missile development is a computer converter that can quickly transform analogue signals--such as pressure measurements--into digital form. In the near future, when guidance devices permit soft landing, rocket cargo and passenger transport will become feasible. Mail may become almost as swift as telephone. We are making rapid progress in the economics of space travel: payload costs for Vanguard were about $1 billion a pound; for the near future launchings, payload cost should be about $1,000 per pound. When payload costs are about a hundred dollars a pound we may expect commercial space flight.[50] Hundreds of other examples of the space program's value for everyday living could be cited. One with wide possibilities is a new welding process by using a high-powered electron beam gun, developed for the fabrication of spaceships and other space vehicles. This method permits welding joints capable of withstanding temperatures up to 3,000° F.; it can be used on metals such as molybdenum and pure tungsten. And, its developers say, it results in welded joints that have deep penetration and narrow weld beads that are virtually free of contamination.[51] Another ingenius application, resulting from the Navy's space research program, has significant utility for medicine and surgery. This is a glass fiber device which, when placed in the mouth during dental work or in the area of surgical incision, permits a much magnified televising of the operation. It holds considerable promise for teaching techniques in many fields.[52] Another example is a finely woven stainless steel cloth designed for parachuting space vehicles back to Earth. The cloth is made of fine wire of great strength which can withstand tremendous temperatures and chemical contamination. The wire from which the cloth is woven is about one-fifth the thickness of a human hair and is believed to have marked potential for industry and consumers alike. Here is an additional list of examples:[53] Microminiature transmitters and receivers--used by police and doctors. Target drone autopilot--used as an inexpensive pilot assist and safety device for private aircraft. Inert thread sealing compound--- used by pump manufacturers serving process industries. Satellite scan devices--used in infrared appliances, e.g., lamps, roasters, switches, ovens. Automatic control components--used as proximity switches, plugs, valves, cylinders; other components already are an integral part of industrial conveyor systems. Missile accelerometers, torquemeters, strain gage equipment--used in auto crash tests, motor testing, shipbuilding and bridge construction. Space recording equipment automatically stopped and started by sound of voice--used widely as conference recorder. Armalite radar--used as proximity warning device for aircraft. Miniature electronics and bearings--used for portable radio and television; excessively small roller, needle and ball bearings used for such equipment as air-turbine dental drills. Epoxy missile resin--used for plastic tooling, metal bonding, adhesive, and casting and laminating applications. Silicones for motor insulation and subzero lubricants--used in new glassmaking techniques for myriad products. Ribbon glass for capacitors--used widely in electronics field. Radar bulbs--used in air traffic control equipment. Ribbon cable for missiles--used in the communications industry. Automatic gun cameras--used in banks, toll booths, etc. Fluxless aluminum soldering--used for kitchen utensil repair, gutters, flashings, antennas, electrical joints, auto repairing, farm machinery, etc. Lightweight hydraulic pumps--used in automated machinery and pneumatic control systems. Voice interruption priority system--used for assembly line production control. Examples such as the foregoing, it might be pointed out, do not generally emphasize an area in which space exploration is making one of its greatest contributions. This is the creation of new materials, metals, fabrics, alloys, and compounds that are finding their way rapidly into the commercial market. Less demonstrable but equally (and perhaps more) significant areas which may expect to benefit from space exploration are set out beginning on page 35. [Illustration. FIGURE 11.--Vital information about the forces which cause weather can be learned from meteorological satellites such as these. Even a slight increase in the accuracy of weather prediction will be worth millions of dollars annually.] FOOD AND AGRICULTURE An extremely difficult problem bound up with space travel of any duration is that of food. Astronauts will not be able to take large supplies of food on their voyages and probably will have to reuse what they do take. Learning how to do this is no easy matter. Some doubt if it can be done. Others are optimistic. The body of scientists now working directly on space feeding and nutrition is working effectively at a rate only attained by high motivation. But this motivation suffices and their efforts will ultimately provide at least a partially closed space feeding system by the time it is critically needed and, eventually, an ideal one for long voyages of man into the remoter reaches of outer space.[54] If the optimists are right, it is conceivable that the information gamed from this research will have profound influence on food and agricultural processes in the future. The use and growth of synthetics or new foods, and their effects on the soil, could prove invaluable as the worlds population climbs and the demand for food multiplies. Better understanding of weather processes, as provided through space exploration, will also be valuable in terms of agriculture. Long-range accurate weather prediction would be worth millions of dollars in proper crops planted and crop damage avoided. Meanwhile, as in other technological areas, space research is providing specific new tools for the food and agriculture industry. Infrared food blanching, for instance, is highly effective in preparing foods for canning or freezing. The development of a new forage harvester based on principles of aerodynamics uncovered by missile engineers is another example. COMMUNICATIONS This is a field of enormous promise, and its practicality has already been demonstrated to the extent of placing satellites into precise orbits, such as Tiros (weather) and Transit (navigation), and of communicating at long distances--23 million miles in the case of Pioneer V. As a result: Government and industry technicians are rapidly developing new Earth satellites to beam not only television programs but radio broadcasts and phone conversations to every spot on Earth that's equipped to receive them. Thus this space project, far more than most, will touch the ordinary citizen. The goal: a workable, worldwide communications system in space before this decade is over. It will be, declares one researcher, "the ultimate in communications."[55] Incidentally, the first worldwide communications system of this type, and whether it is conducted in English or Russian, may have crucial prestige and propaganda ramifications. Such facilities should be possible through a system of carefully placed satellites so that radio signals can be relayed to any part of the globe at any time. Moreover they appear to be essential when one considers that within the next 20 years existing techniques are apt to be stretched beyond reasonable economic limits by demands for long distance communications. It is difficult to see how transoceanic television will otherwise be possible when it is realized that there is presently a capacity of less than 100 telephone channels across the Atlantic and a single television channel is equivalent in band width to 1,000 telephone channels. It appears that a system utilizing satellites is the most promising solution to this problem.[56] More esoteric communications systems may also arise from space research. In some future year when a cruising space vehicle communicates with another space vehicle or its orbiting station, it may use a beam of light instead of conventional radio. Not that radio will be inoperative under the airless conditions of space--rather the reverse--but there is reason to believe that communication by sunlight not only will be cheaper but will entail carrying much simpler and lighter equipment for certain specialized space applications. (The Air Force) is developing an experimental system that will collect sun rays, run them through a modulator, direct the resultant light wave in a controlled beam to a receiver. There the wave will be put through a detector, transposed into an electrical impulse and be amplified to a speaker. Depending on the type of modulator used, either the digital (dot-dash) message or a voice message can be sent.[57] Might not such a system find practical usage on Earth, particularly in sunny, arid lands? WEATHER PREDICTION AND MODIFICATION Meteorological satellites should make possible weather observations over the entire globe. Today, only 20 percent of the globe is covered by any regular observational and reporting systems. If we can solve the problems of handling the vast amounts of data that will be received, develop methods for timely analysis of the data and the notification of weather bureaus throughout the world, we should be able to improve by a significant degree the accuracy of weather predictions. An improvement of only 10 percent in accuracy could result in savings totaling hundreds of millions of dollars annually to farmers, builders, airlines, shipping, the tourist trade, and many other enterprises. Perhaps even greater savings will come from warning systems devised for hurricanes and tornadoes. The slight knowledge which humans actually have of weather forces can be seen from the fact that at present we do not even know exactly how rain begins.[58] Learning to predict it and to modify it, through space application, might help slow down the soil erosion of arable land--that "geological inevitability * * * which man can only hasten or postpone."[59] It is noteworthy that the two leading nations in space research, the United States and the U.S.S.R., are among the most affected by soil erosion. The "leg up" which the United States has in this particular phase of space research is illustrated by the acute photographic talents of the Tiros satellite and their meaning to weather experts. The following description of some of the earliest pictures by the Director of the Office of Meteorological Research, U.S. Weather Bureau, is illuminating. This picture, labeled "No. 1," was the storm that was picked up in the early orbits of Tiros on the first day of launch, April 1. This shows the storm 120 miles east of Cape Cod, with dry continental air streaming off the United States, not shown by clouds, and off the coast the moist air streaming up to the north, counterclockwise around the center, producing widespread clouds and precipitation as far north as the Gulf of St. Lawrence. On that same day mention was made of a storm in the Midwest. That is illustrated by photograph No. 2. This was centered over southeast Nebraska, a rather extensive storm. Again, we have a clear air portion shown by a dark area, the ground underneath, which has less brightness than the clouds, the cold air from Canada streaming into that area, not characterized by clouds, and to the east the moist air from the Gulf of Mexico, in this general neighborhood, streaming around into that center and producing rather widespread rains. In this case near the Gulf of Mexico, where the cloud is extremely bright, indicating that the clouds are very high, thunderstorms were found in that area. [Illustration: FIGURE 12.--Storm center over Nebraska photographed by the first U.S. weather satellite, Tiros, on April 1, 1960. The extent of the picture can be seen from the accompanying weather map.] It is a sort of situation in which tornadoes are to be found in this very bright cloudy area, especially this time of year in the Midwest. A third vortex was observed, also April 1, in the Gulf of Alaska, 500 miles southeast of Kodiak Island. The vortex circulation is clearly evidenced by the clouds which form in a circular array, and the large clear area in the center of the storm. No. 4 picture refers to a very big storm 1,500 miles in diameter located 300 miles west of Ireland on April 2. This is a very old storm which was whirling around, had no fronts associated with it. It has long since wound up around the center. There is a rather well-marked structure to the clouds that you can see. It is quite different from the pictures in the first two. These are storms mostly over the continental area or just off the coast. The storms over the oceans seem to show more of a banded structure. By that I mean circular bands of clouds, of width perhaps ranging from 20 miles to a few hundred miles, spiraling around the center in a counterclockwise manner.[60] HEALTH BENEFITS Of all the problems contingent upon space flight it is doubtful if any are more perplexing than the biological ones. In fact, it now appears quite likely that the limiting factor on manned space exploration will be less the nature of physical laws or the shortcoming of space vehicle systems than the vulnerability of the human body. In order to place humans in space for any extended period, we must solve a host of highly complicated biological equations which demand intensive basic research. The other side of the coin, however, is that when scientific breakthroughs do occur in this area, they will probably be among the most beneficial to come from the space program. An idea of what is going on in the space medicine field can be obtained from this summary: Engineers already have equipped man with the vehicle for space travel. Medical researchers now are investigating many factors incident to the maintenance of space life--to make possible man's flight into the depths of space. Placing man in a wholly new environment requires knowledge far beyond our current grasp of human biology. Here are some of the problems under investigation: The determination of man's reactions; the necessity of operating in a completely closed system compatible with man's physiological requirements (oxygen and carbon dioxide content, food, barometric pressure, humidity and temperature control); explosive decompression; psychophysiological difficulties of spatial disorientation as a result of weightlessness; toxicology of metabolites and propellants; effects of cosmic, solar, and nuclear ionizing radiation and protective shielding and treatment; effects on man's circulatory system from accelerative and decelerative g. forces; the establishment of a thermoneutral range for man to exist through preflight, flight, and reentry; regeneration of water and food.[61] In addition, intensive efforts are being brought to bear on such problems as the effect on humans who are deprived of their sensory perceptions, or whose sensory systems are overloaded, or who are exposed to excessive boredom or anxiety or sense of unreality, or who must do their job under hypnosis or hypothermia (cooling of warm-blooded animals). A recent space medicine symposium heard this theory advanced by a prominent medical scholar: Attractive, indeed, for the space traveler would be the choice of hibernating during long periods when there was nothing he had to do. With the increase of speeds and the lowering of metabolism, consideration of flights running several hundred or even thousands of years cannot be offhandedly dismissed as mere fantasy. During prolonged flights of many months or years there will be very little to see and that of negligible interest. The most practical way of dealing with the problem might well be to have the pilot sleep 23 of the 24 hours.[62] Lowering the body temperature would be one way of inducing the necessary deep sleep. Another possibility of handling some of the biological problems of space flight, suggested by another physician, would be for astronauts to discard the 24-hour Earth day and establish a longer rhythm for their lives.[63] At any rate, and while we may not now see just how it will come about, knowledge gained from experiments such as these may result in important medical and psychological advances. In the drug and technological area of medicine, concrete benefits have already resulted from the national space program. These include, as already mentioned, a drug developed from a missile propellant to treat mental ills, a means of rapidly lowering blood temperature in operations, and a small efficient valve which could replace the valve in a human heart. Particularly gratifying, from the standpoint of medical value is the Army's work toward an anti-radiation drug which could be taken before exposure to reduce the biological effects of radiation.[64] Such a drug, which is of special interest to astronauts who might be required to subject themselves to varying belts of radiation, might be of even greater use in the cause of civil defense. A final and far-reaching phase of the health side of space exploration deals with the basic nature of biology itself--how and under what conditions life grows. Up to now biological science has been largely "the rationalization of particular facts and we have had all too limited a basis for the construction and testing of meaningful axioms to support a theory of life."[65] Through research made possible by the space program it may be possible to alter this condition. "The dynamics of celestial bodies, as can be observed from the Earth, is the richest inspiration for the generalization of our concepts of mass and energy throughout the universe. The spectra of the stars likewise testify to the universality of our concepts in chemistry. But biology has lacked tools of such extension, and life until now has meant only terrestrial life."[66] [Illustration: FIGURE 13.--Biological reactions uncovered in space medicine studies, such as this centrifuge experiment, may lead to important health discoveries.] The secrets which this research may divulge and their meaning for human health can only be imagined. But they certainly would not be minor. EDUCATION BENEFITS No enterprise has so stirred human imagination as the reach of man toward the exploration of space. New worlds to explore. New distances to travel--3,680 million miles to Pluto, the outermost planet of our solar system, 8 years journey at 50,000 miles per hour when we attain such a capability. Innumerable problems ahead. New knowledge needed in almost every branch of science and technology from magneto fluid dynamics to cosmology, from materials to biology and psychology.[67] "New knowledge needed" means better and stronger education is essential. And not only in the physical sciences. In the social sciences and the arts as well. Certainly man's space adventure can help profoundly to make a finer creature of him, but only if his adventures on Earth can do so as well. Essentially what this means to a social psychologist is that we must somehow raise our level of education to the point where most men most of the time can appreciate and actively absorb the implications of knowledge and developments in all areas sufficiently to let them enrich their personal philosophies. Obviously this kind of education is only in part a scientific one.[68] Moreover, the technical and management aspects of the space program involve collaboration with nonscientific persons such as businessmen, bankers, and public officials in assessing worthwhile objectives and in judging the technical and economic feasibility of projects designed to accomplish these objectives.[69] Consequently each type must educate the other in his own specialty if an effective, stepped-up space program is to be achieved. _The demand_ Apparently the demand for specific formal education in the science of astronautics is increasing faster than it is being supplied. Although many colleges and universities have been setting up courses dealing with astronautics, the state of the art does not seem to have crystallized to the extent that it permits fashioning a career in the field at the educational level. Of course, discontent is created. One publication has editorialized: We have received a surprising number of letters from young people who actually want to know how and where they can get started in a career in astronautics. These, for the most part, are high school students--and, evidently, they couldn't get the information they wanted from their own school. * * * Isn't the age of space yet important enough for all the high schools to sponsor interest in our space programs and to point out the need for a constant flow of young brains?[70] The answer undoubtedly is that such grassroots demand will bring about increased academic curricula in astronautics in direct proportion to its magnitude. Meanwhile, the availability of work for persons with a background in space-related subjects can be gaged to some extent by observing the variety of personnel requirements on major space exploration projects. A single American firm, for example, uses 49 different professional specialists in its work for the National Aeronautics and Space Administration and in its space work for the Department of Defense.[71] Multiplied by the thousands of companies which are doing similar work, the list gives an idea of the astronautic demand confronting the Nation's educational institutions: Acoustician Aerodynamicist Aeronautical engineer Agricultural engineer Astrodynamicist Astronomer Astrophysicist Biochemist Biophysicist Ceramics specialist Chemist Computer specialist Crystallographer Development engineer Doctor of medicine Electrical engineer Electronic engineer Experimental physicist Flight engineer Gyroscopics specialist Hydraulic engineer Information theory analyst Inorganic chemist Logical designer Magnetic device engineer Mathematician Mechanical applications engineer Mechanical engineer Mechanisms specialist Medical electronic engineer Metallurgical engineer Methods engineer Nuclear physicist Oceanographer Organic chemist Physical chemist Pneumatic engineer Process engineer Production engineer Project engineer Psychologist Reliability engineer Sociologist Solid state physicist Structural engineer System analyst Theoretical physicist Thermodynamicist Transducer engineer [Illustration: FIGURE 14.--Exploration within the solar system means a wealth of new knowledge which could lead to learning the secrets of life.] FOOTNOTES: [50] 25 supra. See also address to the American Bankers Association, Oct. 28, 1958. [51] Space Business Daily, June 17, 1960. [52] Feldman, George J., cited in a letter to the House Committee on Science and Astronautics, Apr. 29, 1960. [53] From Michelson, Edward J., "How Missile-Space Spending Enriches the Peacetime Economy," Missiles and Rockets, Sept. 14, 1959, pp. 13-17. [54] Tischer, R. G., "A Search for the Spaceman's Food," Space Journal, December 1959, p. 46. [55] Kraar, Louis, Wall Street Journal, May 4, 1960. [56] 7 supra. [57] Release No. 38-60, Air Research and Development Command, May 2, 1960. [58] Lear, John, "Where Does Rain Begin?" New Scientist, Mar. 24, 1960, p. 724. [59] "Wind and Soil," New Scientist, May 26, 1960, p. 1327. [60] Wexler, Dr. Harry. Press conference conducted by the National Aeronautics and Space Administration, Apr. 22, 1960. [61] Lockheed, Missiles and Space Division, medical research, Sunnyvale, Calif. [62] Lewis, Dr. F. J., before the Space Flight Symposium, San Antonio, Tex., May 28, 1960. [63] Kleitman, Prof. Nathaniel, before the Space Flight Symposium, San Antonio, Tex., May 26, 1960. [64] Taylor, Lt. Col. Richard R., USA (MC), testimony before the House Committee on Science and Astronautics, June 15, 1960. [65] Lederberg, Joshua, "Exobiology-Experimental Approaches to Life Beyond Earth," Science in Space, ch. IX, National Academy of Sciences, Washington, D.C., February 1960. [66] Ibid. [67] Dryden, Dr. Hugh L., speech before the Engineering Society of Cincinnati, Feb. 18, 1960. [68] Michael, Donald N., "Space Exploration and the Values of Man," Space Journal, September 1959, p. 15. [69] 67 supra. [70] Space Age, August 1959, p. 3. [71] Minneapolis-Honeywell, Military Products Group. V. LONG-RANGE VALUES In assessing the _practical_ values of space exploration it does not seem logical to limit considerations to those values which are immediate or near-future ones. The worth of a present activity may be doubled or trebled because of its long-range potential. Such values may not be practical within the context of today's usage, but they may be extremely practical if we are willing to concede that those of us living today have an interest in and a responsibility for what happens on Earth in the decades and centuries to come. TROUBLE SPOTS Thinking along these lines it is not difficult to conjure up a picture of some of the difficult physical and social problems which will be facing the Earth in the years which stretch ahead. The foregoing sections of this report, for example, have already indicated extensive difficulties inherent in at least five major categories. (1) Bursting population. (2) Acute water shortage. (3) Soil erosion and disappearance. (4) Too much leisure. (5) Intensified nationalism. In each area it is probable that space exploration will ultimately play an important role. _Population_ Social scientists have been warning for years of the drastic social upheavals which must inevitably accompany an "exploding" population. It is a problem the complexity of which grows in geometric progression as time goes on. In the United States nearly 300 years were required to produce 90 million people. In the past 60 years this number has doubled. The implications are obvious. They are only too plain to urban and suburban planners who endeavor to cope with the antlike construction and activity of the human race as it burgeons with each succeeding year. Of course, this is not a domestic matter but a global one. Its seriousness has been described as follows: "Projection of the post-World War II rate of increase gives a population of 50 billions (the highest estimate of the population-carrying capacity of the globe ever calculated by a responsible scholar) in less than 200 years."[72] A European professor of medicine adds that any surge in human longevity at this time is quite undesirable from the standpoint of making elderly persons useful or cared for. "The problems posed by the explosive growth of populations * * * are so great that it is quite reassuring to know that biologists and medical men have so far been unsuccessful in increasing the _maximum_ lifespan of the human species * * * and * * * it would be a calamity for the social and economic structure of a country if the mean lifespan were suddenly to increase from 65 to 85 years."[73] Some anthropologists pessimistically wonder if man is going to prove like the locust by populating himself into near extinction from time to time. Without subscribing to this view, one must nevertheless take notice of the difficulties posed by population increase, not merely those of food, shelter, education, and the like but also those resulting from cellular, cramped, close living. Whichever phase of the problem is studied, it seems not unreasonable to conclude that space research will help find a solution. New ways to produce food, new materials for better shelter, new stimuli for education--all of these are coming from our space program. As for the matter of adequate living room, space research may result in ways to permit an easy and efficient scattering of the population without hurting its mobility. This might result from the development of small subsidiary types of craft, or "gocarts," originally designed for local exploration on other planets. Such craft, whether they operated by air cushion, nuclear energy, gravitational force, power cell, or whatever, conceivably would permit Earth's population to spread out without the need for expensive new roads--which, by the way, take millions of acres of land out of productive use. A development of this sort, together with new power sources to replace the fossil fuels on which factory, home, and vehicle now depend, might also all but eliminate the growing smog and air-pollution blight. _Water shortage_ A direct result of the population increase, multiplied by the many new uses for which water is being used in home appliances, etc., and plus the greatly increased demand for standard uses such as indoor plumbing, irrigation, and factory processing, is the likelihood that water shortage will be high on the list of future problems. Ways to conserve and reuse water, together with economical desalting of sea water, will be essential in the decades ahead. Space research may provide part of the answer here, too. (See New Water Sources and Uses, sec. III.) _Soil erosion_ The Russian steppes of Kazakhstan are providing the world with a great contemporary dust bowl, reminiscent of the middle 1930's when dust from the Great Plains stretched from Texas to Saskatchewan. Questionable agriculture policies, drought, and strong easterly winds are among the forces blamed for the trials of southern Russia.[74] So great is the extent of this disturbance that the dust cloud has been identified in photographs taken by American weather satellites. Of course, "wind erosion is only one of the processes whereby the Earth's arable land is diminishing and the deserts increasing; erosion by water can also sweep away the soil."[75] But insofar as the current dust bowl of the Soviet steppes has "diminished food resources at a time when the number of mouths to feed is increasing so rapidly, the world is the poorer."[76] What can space research do about this vital trend, which again seems destined to accelerate in the future? While we cannot be sure, we can conjecture that improved soil conservation might turn out to be the greatest benefit of weather understanding and modification. Agriculture policies might be adapted to the long-range patterns uncovered by weather satellites and, eventually, through better understanding of the making of weather, it may be possible to modify weather forces in a manner which will preserve the soil. In a more remote vein, it may be that knowledge gained from a first-hand study of the Moon or other planets in the solar system will eventually contribute to the conservation of soil on Earth in ways as yet unimagined. _Added leisure_ Acquiring more time for leisure sounds good. Very much more leisure than most people now have, however, is apt to present trouble in itself. Since it appears that the time is not far away when those living in the highly developed countries will no longer have to concentrate their prime energies on the traditional quest for food, clothing, and shelter, a potentially dangerous vacuum may be the result. At least the psychologists seem agreed that people must feel a useful purpose in their lives and have ways to pursue it. Above all, leisure makes a challenge to the human spirit. Athens, in her Golden Age, displayed a genius for the creative use of leisure which can be seen as complementary, and indeed superior, to her genius for military and commercial ventures. There have also been such periods of all-pervasive inspiration in the history of other peoples * * *. The doubling of our standard of living will present a growing challenge to the human spirit and produce graver consequences, should we fail to meet it. We neglect the proper use of leisure at our peril.[77] In other words, the answer to the problem does not lie solely with the golf course, the yacht club, the theater, or the lengthened vacation. Much more will be required. The intellectual stimulus of space exploration and research, which undoubtedly will divide into numerous branches like capillary streaks from a bolt of lightning, should be markedly useful in helping to fill this vacuum. Space research would seem particularly applicable in this role since it deals with fundamental knowledge and concepts which are satisfying in terms of psychological needs and sense of purpose. _Intensified nationalism_ Ever since World War II the era of colonialism has been on the wane. Many nations have proclaimed, won, or wrested their independence during that period. Others appear to be on the verge of doing so. At any rate, it is clear that in the decades ahead the world is going to see the rise of even more independent nations with strong nationalistic feelings. History implies that developments of this sort are often accompanied by international unrest--because of the normal ebullience of national adolescence and the desire to be accepted by the world community, as well as a variety of concomitant political and economical upheavals. For whatever trials may lie ahead on this score, space exploration may prove to be much needed oil on rough water. Ambitious, advanced, sophisticated space exploration in the future is almost certain to require a high degree of international cooperation and perhaps even a pooling of resources and funds to some degree. Already America has found it expedient, in some cases mandatory, to depend on facilities in other countries for her ventures into space. A good example is the close cooperation between the United States and tracking bases located in Canada, Australia, South Africa, and elsewhere. An even better one is the important part played in U.S. efforts by England's giant radio telescope at Jodrell Bank. Most of our launches are followed by this equipment and much of the best scientific information gained from it. In the case of Pioneer V, Jodrell Bank was essential to keep in touch with the satellite at the longer distances and, moreover, was actually required to separate the fourth stage of the launch vehicle and direct the payload toward its Venus orbit. Mutual need and cooperation thus fostered by space exploration can be expected to siphon off some of the political tensions of the future, especially as more and more nations become interested in space and inaugurate complex programs of their own. LIMITATIONS ON SPACE RESEARCH There are some who are convinced that the exploration of space is rigidly limited and that the landing of men on extraterrestrial bodies other than the Moon is quite improbable. They are sure that extensive travel outside the solar system is impossible. Admittedly, the problems of such travel are enormous. But are they incapable of solution? Twenty-six million miles to Venus, 49 million miles to Mars, 3,680 million miles from the Sun to Pluto at the outer edge of the solar system. The nearest of the stars is 25 million, million miles away, and travel to it at 10 miles per second would require 80,000 years. Is the travel of man to the stars a futile dream? Each generation of man builds on the shoulders of the past. The exploration of space has begun; who now can set limits to its future accomplishments?[78] [Illustration: FIGURE 15.--Need for international cooperation in the U.S. space program is illustrated by this map showing the areas from which help must be procured for projects already planned or underway.] That is the thought of one of the Nation's most expert space scientists. _"Who now can set limits * * * ?"_ It seems to mesh curiously well with one of the most interesting phenomena of our day--the emergence of a breed of engineers, technicians, teachers, and scientists who do not recognize limits and who refuse to concede that something cannot be so because it fails to fit conventional patterns or conform to the physical laws of the universe as we now know them. Of this there is growing evidence. For many years it has been an accepted "fact," for instance, that the Moon is a dead world with no life upon it. The suggestion made by the great 16th century mathematician, Johannes Kepler, that some life might exist on the Moon was debunked into silence long since. Yet today a fellow of the British Royal Astronomical Society writes that the first men to arrive on the Moon may find not only plant life but possibly animal life. "The fact that terrestrial organisms may be unable to survive in the surroundings of another planet is by itself no more significant than that fishes and other marine animals die when exposed to the air. From their point of view air is uninhabitable because they have failed to equip themselves with lungs."[79] And he adds that his surmise "leaves out of account the possibilities of the Moon's underground world, which are incalculable, for there water, the vital gases, congenial temperatures, and increased pressures will all be present. Only sunlight is absent." Then there is Project Ozma, the search for life on other planets or in other star systems, which began in April 1960 at Green Bank, W. Va. It is being undertaken by the National Radio-Astronomy Observatory and consists of carefully directed listening by radio-telescope for signs of intelligent broadcasts originating outside Earth. At Stanford University another astronomer is concentrating the efforts of part of his laboratory on behalf of a similar idea. The chances are, he believes, "that the superior races of other planets in other galaxies have already developed a communications network among themselves, and have entered a joint program to scan all the other solar systems looking for signs of awakening civilization among the backward planets. Each of the advanced communities might pick as its probe assignment a single other solar system--and one such probe may well be circling our Sun right now on a routine check for life."[80] Unexplained delayed echoes of earthly radio transmissions received in the past, it is thought, could be evidence of such a scheme. Are goings-on such as these nonsense? Here is the answer given by one hard-headed science writer: Centuries may pass before there is any sign of intelligence outside the Earth. But the advantages of communication with another civilization that has survived our present dilemmas are far too great to permit the experiment to be abandoned.[81] The results of recent and more orthodox experiments have already done much to shake the complacency of scientists in regard to their concepts of space. Investigations have disclosed that, far from being a complete vacuum, space is relatively full of matter and energy. Hydrogen gas, radiation belts, cosmic particles, solar disturbances of unknown nature, micrometeorites--and, from Pioneer V, proof of a 5-million ampere electromagnetic ring centered about 40,000 miles away.[82] The director of the Smithsonian Astrophysical Laboratory in Cambridge, Mass.,[83] has said that more and more startling astrophysical information was gathered during the first few weeks of the space age than had been accumulated in the preceding century. In brief, it is becoming the vogue in science to refuse to say "impossible" to anything. On the contrary, the watchword for tomorrow is shaping up as "take _nothing_ for granted." FUNDAMENTAL KNOWLEDGE ABOUT LIFE Everything learned from space exploration thus far indicates that the knowledge lying in wait for those who manage to observe the universe from outside Earth's atmosphere will be far grander than anything uncovered to date. We may finally learn the origin of our universe and the method of its functioning. A good part of this knowledge may be no farther away than the next 3 to 5 years. Satellite telescopes now under construction are expected to elicit far more information than even the 200-inch giant at Mount Palomar. One such observatory satellite, to be launched in 1963 or before, "will permit a telescope of about 10 feet in length to point at heavenly bodies within a tenth of a second of arc for periods up to an hour. Present plans call for an orbit between 400 and 500 miles, as a lifetime of at least 6 months is required to observe the entire celestial field."[84] Perhaps, and sooner than we think, we shall find a clue to the destiny of all intelligent life. Perhaps the theory advanced by a noted eastern astronomer will turn out to be true--that biological evolution on the habitable planets of the universe may be the result of contamination left by space travelers arriving from (and leaving for) other worlds. In other words, the fruition of life on the various planets of the millions of solar systems might be the product of a wandering group of astronautic Johnny Appleseeds who leave the grains of life behind them. "Space travel between galaxies has to be possible for this, but of course this needs to be only quite a rare event. In a time of about 3.3 billion years, the most advanced form of life occurring in a galaxy must be able to reach a neighboring one."[85] The notion seems fantastic. But when we look clear to the end of Earth's road (and assuming the astrophysicists are right in their theories about the evolution and ultimate death of our solar system) we know that Earth will one day become uninhabitable. Life on Earth must then perish or move elsewhere. If we further assume that mankind will not want to die with his planet and if we acknowledge that other worlds may have been through this entire cycle in eons past--perhaps the notion is not so unreasonable after all. Whatever the truth is on this score, space exploration will certainly be of "practical" value to our descendants when that dim, far-off day arrives. PSYCHOLOGICAL AND SPIRITUAL VALUES Long before the arrival of that millennium, however, the knowledge and understanding awaiting us through the medium of space exploration is certain to have profound effects on the human race psychologically and spiritually. It already has had effects on humans of all ages. Adults, who are paying the taxes to support the space exploration program and reaping its practical values, are also thinking of themselves, their country, and their world in broader, more knowledgeable terms. In a sense, children may be even more deeply involved. There is a special group which may play a useful role in spreading the new values growing from the exploration of space, and this is the children who play at spaceman today. Whether or not they take this interest with them beyond childhood remains to be seen. However, the unique fact in the present situation is that never before have children rehearsed a role that really will not exist until they are adults. To be sure all of them will not fulfill this childhood role, but the fact that the reality lies ahead rather than in the past (as with cowboys and Indians) may stimulate them to retain a sensitivity for the various meanings man in space can have for our future.[86] Put it another way--if it is true, as a modern Chinese philosopher has said, that the search for knowledge is a form of play, "then the spaceship, when it comes, will be the ultimate toy that may lead mankind from its cloistered nursery out into the playground of the stars."[87] [Illustration: FIGURE 16.--Space vehicles of the future may look like this artist's drawing of an electrical propulsion craft. The nuclear reactor is located at the extreme left, followed by a neutron shield, heat exchanger, gamma-ray shield and propellant. The center tank houses turbogenerating equipment. Excessive heat is dissipated in the large radiator. At the extreme right are two crew cabins, landing vehicle and a ring-shaped accelerator.] MATURING OF THE RACE The psychological and spiritual changes necessitated by this evolution may be at a cost far beyond dollars--because many of us will be hard put to negotiate them, especially if they come too rapidly. Nevertheless, negotiating them must also be placed in the category of "practical" values--for in the long run it seems to be an essential part of the maturing of mankind. The years ahead will face us with many sputniks and thereby will require of our citizens stern, costly, and imaginative participation in programs to meet and surmount the many complex challenges with which our growing technology confronts us. To succeed in space and to succeed on Earth, we must somehow learn to make the larger world of ideas, so brilliantly exemplified by the satellites, the immediate environment of the individual. There is a race we must run--the race for an enlightened and involved public.[88] So if we can accept the wrenches which space exploration is apt to apply to our time, pocketbook, energy, and thinking, the values and rewards as outlined in this report should gather headway and grow continuously greater. Space technology is probably the fastest moving, typically free-enterprise and democratic industry yet created. It puts a premium not on salesmanship, but on what it needs most--intellectual production, the research payoff. Unlike any other existing industry, space functions on hope and future possibilities, conquest of real estate unseen, of near vacuum unexplored. At once it obliterates the economic reason for war, the threat of overpopulation, or cultural stagnation; it offers to replace guesswork with the scientific method for archeological, philosophical, and religious themes.[89] Such conclusions seem a bit rosy. But sober study indicates that they may not be too "far out" after all. FOOTNOTES: [72] Hauser, Philip M., "Demographic Dimensions of World Politics," Science, June 3, 1960, p. 1642. [73] Bacq, Prof. Z. M., "Medicine in the 1960's," New Scientist, Jan. 21, 1960, p. 130. [74] 59 supra. [75] Ibid. [76] Ibid. [77] "The Challenge of Leisure," M. G. Scott, Ltd., London, August 1959, p. 20. [78] 27 supra. [79] Firsoff, Dr. V. A., "The Strange World of the Moon," Basic Books, London, 1959. [80] Reported by David Perlman, San Francisco Chronicle, June 7, 1960. [81] Lear, John, "Is Anybody There?," New Scientist, Apr. 14, 1960, p. 933. [82] Aviation Week, May 9, 1960, p 32. [83] Whipple, Dr. Fred L. [84] Western Aviation, June 1960, p. 16. [85] Gold, Dr. Thomas, "Cosmic Garbage," address to the Space Scientists Symposium, Los Angeles, December 1959. [86] 68 supra, pp. 12, 13. [87] 6 supra, pp. 3, 4. [88] Michael, D. N., "Sputniks & Public Opinion," Air Force, June 1960, p. 75. [89] Industrial Research, December 1959, pp. 8, 9. 
25420	----	None 
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27298	----	MARVEL CARBURETER AND HEAT CONTROL AS USED ON SERIES 691 NASH SIXES BOOKLET S MARVEL CARBURETER CO. FLINT, MICHIGAN U.S.A. MODEL "S" CARBURETER Used on Series 691 Nash Sixes The carbureter measures the fuel charges for the engine and automatically mixes them with the proper amount of air to form a highly combustible gas. The Marvel Model "S" Carbureter is of the automatic air valve, heat controlled type. Its outstanding advantages are: 1. Simplicity of construction and operation. 2. Quick starting in any weather. 3. Automatically controlled heat application to ensure complete vaporization of fuels. 4. Economy in fuel consumption. 5. Ease of adjustment to meet varied driving and climatic conditions. CONSTRUCTION The construction embodies a main body or mixing chamber and a conventional float chamber bowl with fuel strainer attached at point of entrance of fuel to bowl. Within the mixing chamber are two nozzles which proportion the amount of gasoline used in the mixture. One of these nozzles, called the "low speed," is regulated by the gasoline adjustment screw at bottom of carbureter and the other, called the "high speed," is controlled by the automatic air valve. An air screw is provided which regulates the pressure of the air valve spring enclosed therein. Within this screw is also enclosed a plunger connected by a link to the air valve. The function of this plunger is to provide a resistance in addition to that of the air valve spring to assist in acceleration. This arrangement of plunger and air valve screw is termed the dash pot. A further control of the high speed jet is provided by the fuel metering valve operated by the carbureter throttle. This valve provides the maximum fuel feed to the "high speed" nozzle when the throttle is fully opened for high speeds and for quick "pick up." During the ordinary driving ranges this valve controls the amount of fuel being used, thus providing all the economy possible. This valve is entirely automatic and requires no adjustment. The passage-way from the mixing chamber to the intake manifold is controlled by a butterfly valve which is called the throttle-valve and is connected to the throttle-lever on the steering wheel as well as to the foot accelerator, its position determining the amount of gas and air or mixture being fed the engine. STARTING A choke button is provided on the instrument board to assist in starting. Pulling out this button closes a butterfly choker valve (see cut) in the air intake passage of carbureter which restricts the air opening of the carbureter, and consequently produces a richer mixture. To start engine, pull out choke button all the way. Advance spark lever about half way and throttle lever about one-quarter way and depress starter pedal. As soon as motor fires when starting, this control should be released part way, otherwise too much fuel will be drawn from carbureter, causing flooding of the motor and failure of the latter to continue to promptly fire. After starting, motor should be allowed to run "part choke" as stated for a few minutes while warming up, then the choker control should be fully released, or pushed in completely on the instrument board, and engine allowed to run normally for sometime until water in cylinder jackets is thoroughly warmed up before starting to make final carbureter adjustments. HEAT CONTROL--STOVE In the colder seasons warm air is fed to air intake of carbureter through the warm air elbow "F" (see cut). This elbow connects the carbureter with the warm air stove, which is a casting surrounding the two exhaust heat tubes which supply exhaust heat to the carbureter jackets as described below. The amount of heat required for proper carburation depends on the temperature of the outside air. The first means of control is in the warm air stove just described, which should be connected to the carbureter furnishing warm air to carbureter air intake in all seasons of the year when the outside air temperature is below 50° F., whenever the outside air temperature runs above this point cold air should be furnished to carbureter air intake. This can be done by loosening the wing nut holding the warm air elbow "F" on the stove and also loosening the set screw holding this elbow in the air intake of carbureter, after which slide elbow out of air intake and revolve it--180 degrees about an horizontal axis and re-insert in carbureter air intake and lock in place with set screw. The opening in the elbow now is turned down away from the stove and draws in only cold air. The above procedure, it must be understood, will vary somewhat due to differences in locality, altitude and fuels used, but it should be borne in mind that the best economy can be had with cold air passing to the carbureter, and the stove should not be connected until the acceleration and performance of the job requires the use of warm air for the best results. The adjustment of the carbureter should be made per the above description of the stove, as the latter is used for meeting weather conditions and should be set as described. HEAT CONTROL--CARBURETER JACKETS The carbureter and manifolds have been designed to utilize the exhaust gases of the engine to insure complete vaporization and a consequent minimum consumption of fuel. This is accomplished by surrounding the upper portion of the mixing chamber with a large heat jacket provided with an inlet and an outlet opening and connected by means of tubes to an exhaust manifold valve body in the exhaust pipe of the engine; this valve body, housing a large valve called the main-exhaust-heat-valve ("C" in cut) within the body itself, the return or outlet tube from the carbureter heat jacket entering the valve-body in the lower portion below the main-exhaust-heat-valve. The main-exhaust-heat-valve "C" is connected by means of a lever and long connecting rod to the throttle lever of the carbureter so that when the throttle valve is operated the main-exhaust-valve is operated simultaneously with it. The purpose of the carbureter heat jacket and valve in exhaust line with connections described, is to provide means for utilizing the heat of the exhaust gases of the motor for vaporization of the fuel supplied the engine by the carbureter and to do so automatically. The automatic feature of same is accomplished by setting the Main-Exhaust-Heat-Valve "C" by means of the long connecting rod, in closed position with the closed or idling position of the throttle valve, thus providing for and causing all of the exhaust gases of the engine to pass through the heat jacket of the carbureter when engine is idling and to regulate the volume of this heat as throttle is opened by automatically opening the Main-Exhaust-Heat-Valve, thus allowing the increasing volume of the exhaust gases to pass on out through the main exhaust pipe without being deflected and by-passed to the carbureter heat-jacket as the motor speed increases. [Illustration: HEAT SETTING No. 1] By referring to the cut shown (See Page 5) and noting "Heat Setting No. 1," it will be noted that valve "C" in main exhaust line is fully closed with the closed or idling position of the throttle valve. This adjustment is accomplished by having long connecting rod "R" from valve "C" Lever set in "Hole No. 1," in Throttle Lever "L," being sure that when throttle valve is standing in fully closed or idling position that valve "C" is also in closed position, proving out the latter feature by loosening connection of valve "C" lever holding long connecting rod; holding Throttle Lever "L" in closed or idling position and bringing up valve "C" lever on connecting rod "R" as far as it will go to the right toward the carbureter and tightening its connection on the connecting rod in that position. After having made the adjustment as just described, it is assured that "Heat Setting No. 1" has been properly made and that all of the heat possible from the exhaust has been secured. This "Heat Setting No. 1," provides as stated, for the most exhaust heat obtainable and should be used during the entire year, except in extremely hot seasons or hot climates or when high-test gasoline is being used in engine and even then unless engine is losing power due to excessive heat. If loss of power or mileage due to too much heat is experienced, first be sure that it is not due to driving on hot-air instead of cold-air. After making this observation, if there is still too much heat, refer to cut (See Page 7) describing "Heat Setting No. 2." It will be noted that connecting rod "R" from valve "C" is removed from "Hole No. 1," in Throttle Lever "L" and placed in "Hole No. 2," in Throttle Lever. This change is all that is necessary in order to reduce the amount of heat applied to carbureter. In "Heat Setting No. 2," when the throttle is in closed or idling position, valve "C" is quite aways off its seat. This adjustment provides for a great deal less heat than is provided by "Heat Setting No. 1" and is all that is required in the reduction of the volume of heat together with driving on "Cold" air for the main-air-supply, in the warmest weather or hottest climates. [Illustration: HEAT SETTING No. 2] NOTE--After original position of valve "C" is made as described in "Heat Setting No. 1" do not again readjust valve "C" on connecting rod but when changing from "Heat Setting No. 1" to "Heat Setting No. 2," merely change position of long connecting rod from "Hole No. 1" to "Hole No. 2" in throttle lever. ADJUSTMENT No change should be made in the carbureter adjustments until after an inspection has been made to determine if the trouble is in some other unit. It should be noted that the gasoline lines are clear, that there is gasoline in the vacuum tank, that there are no leaks at connections between carbureter and engine, that the ignition system is in proper condition, and that there is even compression in all cylinders. If it is necessary to test adjustment or to make a readjustment proceed as follows: Set air screw so that the end is flush with the end of ratchet set spring. Loosen packing nut on needle adjustment. Turn gasoline adjustment to the right very carefully so as not to injure the needle point, until the valve is closed gently against its seat. Then turn to left approximately one complete turn which will bring notch in the disc handle directly below the guide post above it. Tighten packing nut to hold needle firmly as set. The notch in disc handle of needle is put in handle after the needle has been carefully calibrated by a flow-meter at the factory, therefore the notch in handle should register with guide post above it. This setting of needle valve is absolutely essential to get the best results. The object in directing that needle be first turned to the right until closed is to insure against two or more turns open, as from closed position to notch (usually about one turn) is the normal setting. This being true it is not necessary to turn needle in to the right firmly but merely far enough to be sure that when turning back to the left, to the notch registering with guide post, that the needle is not more than once around or one turn from its seat. Set stove heat and damper heat as previously instructed above. Pull out choker to closed position and start engine in usual manner. As soon as engine has fired release choker three-fourths of way in. Run until engine has warmed up then push choker all the way in, remembering to never use choker longer than necessary, as when not needed it has a tendency to foul up engine and ruin the lubricating oil in the crank case. Next, set air screw for good idle by either turning to the right a little or backing out to the left as the needs of the engine require, remembering that first of all, the needle must be set as described. With the needle so set and the engine warmed up, the adjustment of the air screw for proper idling is easily accomplished by using a little care. If the air screw is turned in too tight, the motor will roll. If the air screw is not tight enough, the motor will hesitate and perhaps stop entirely. To make a nice clean adjustment for idle, first having set needle as described, turn air screw in quarter of a turn at a time until engine, does roll; then turn back to the left until engine hesitates, indicating that mixture has too much air and is too lean; next turn air screw in to the right three or four notches at a time until engine runs smoothly. This accomplished (and it is very easy to do by proceeding as directed above) the proper adjustment for the entire range of the engine will have been attained, thus insuring the best economy and power. MODEL "S" MARVEL CARBURETER [Illustration: STANDARD EQUIPMENT 1923-24 Series 691 Nash Sixes] If the engine idles too fast with throttle closed, the latter may be adjusted by means of the throttle lever adjusting screw. RICH MIXTURE An over-rich mixture will cause the engine speed to fluctuate through more or less regular periods from high to low speeds; the engine will seem to be mis-firing and there will be noticeable a strong odor, as well as, usually, a heavy black smoke from the exhaust. LEAN MIXTURE The best adjustment is obtained with the fuel and air valves set as described. It must be remembered that too lean a mixture as well as an over rich mixture causes over-heating and loss of power and is not as economical as an adjustment which provides just the proper proportion of gasoline and air. CAUTION It must be remembered that the low speed needle has been carefully calibrated to notch in disc handle and guide post above it, at the factory and that in making an adjustment that the needle must be so set and the rest of the adjusting done with the air screw as described, never varying from described needle setting unless in extreme cold weather, when a little more gas may be carried, or turning off a little when casing head gas is used in hot weather. MARVEL CARBURETER MODEL "S" [Illustration: Nash Series 691 Sixes Parts Price List] Part No. Name Price 10-80 Carbureter Body $ 6.00 10-580 Carbureter Assembly 22.00 11-537 Insert Assembly 7.00 12-77 Accelerator Lever .40 12-78 Throttle Lever .40 14-2 Throttle Fly .25 15-5 10×24×1/2 Insert Lock Screw .05 15-6 Bowl Support Screw .05 15-14 Ratchet Spring Screw .05 15-15 Bowl Cover Screw .05 15-23 Throttle and Choker Fly Screws .05 15-28 Throttle Stop Adjusting Screw .05 15-29 6-32×1/4" French Head Screw .05 15-32 Pilot Set Screw .05 15-43 Square Head Set Screw .05 16-5 Bowl Cover Gasket .05 16-14 Strainer Gasket (fibre) .05 16-16 Strainer Gasket (Copper) .10 16-35 Flange Gasket .10 16-48 Insert Gasket .10 21-519 Throttle Stop Damper Control and Shaft Assembly 22-1 Heater Jacket Plug .20 23-8 Air Screw Shell .50 24-6 Choker Spring .15 24-116 Air Valve Spring .30 24-28 Flusher Spring .15 24-50 Metering Pin Spring .15 24-51 Ratchet Spring .15 25-524 Choker Shaft and Spring Assembly .75 27-10 Choker Fly .25 30-504 Float and Lever Assembly .75 33-501 Float Shaft Assembly .20 35-501 Float Valve Assembly .45 36-4 Strainer Connection to Bowl .40 38-501 Insert Connection Screw .50 43-508 Gasoline Adjusting Needle Assembly .50 44-1 Gasoline Adjusting Needle Packing .10 45-1 Gasoline Adjusting Needle Packing Nut .15 49-56 High Speed Jet .30 56-508 Bowl Cover Assembly .75 58-501 Flusher Assembly .15 64-1 Bowl Support .10 65-1 Brass Bowl 2.50 65-502 Brass Bowl Assembly 6.00 66-3 Metering Pin Lock Wire .05 67-1 Strainer Body .30 67-502 Strainer Assembly 1.00 78-1 Throttle Shaft Washer .05 78-5 3/16 Lock Washer .05 79-8 Metering Pin Housing Space .20 80-3 Metering Pin Plug .15 81-16 Strainer Nut .15 82-1 Cotter Pin .05 83-2 Manifold Stud .05 84-3 Metering Pin Jet .35 95-1 Strainer Gauze .20 119-504 Dash Pot Plunger, Plunger Rod and Washer Assem. .80 125-2 Metering Pin Spring Seat .05 158-2 Metering Pin Housing .15 167-502 Metering Pin Stem and Wire Assembly .10 173-529 Metering Pin and Lock Wire Assembly .45 REPLACEMENT FOR PREVIOUS MODEL NASH SIXES The Model "S" Marvel Carbureter is interchangeable with the Model "K" Marvel Carbureter, which was standard equipment on the 1922 and 1923 Nash Sixes of the early 691 series. The previous series 681 Nash Sixes of 1921, 1920, and 1919, which were equipped with the Model "E" Marvel Carbureter as standard equipment, can be very greatly improved by the installation of the Model "S" carbureter, exhaust damper body assembly necessary for same, and the hot air stove assembly that goes with this installation. Following is the complete Parts Price List of the Model "S" carbureter, damper body assembly and stove parts for same. Notice is called to the fact again that the damper body and stove parts are not needed on the early 691 series of 1922 and 1923. REPLACEMENT PARTS PRICE LIST For 1919-1922 Series 681 Nash Sixes 10-579 Carbureter and Heat Equipment Complete $30.00 Consisting of the Following Parts: Part No. Name Price 10-580 Carbureter Assembly 1 22.00 128-506 Damper Body and Stove Assembly 8.00 15-16 10×24×3/8 F.H. Machine Screw 1 $ .05 15-43 1/4×20×1/2 Std. Square Head Set Screw 2 .05 15-53 5/16×18×2-1/2 Cap Screw 1 .05 15-54 3/8×16×1 Standard Square Head Set Screw 2 .05 17-14 Exhaust Shut-off Valve Connecting Rod 1 .10 17-15 Damper Connecting Rod (Main Damper) 1 .20 19-2 Exhaust Manifold Damper Fly 1.00 19-9 Warm Air Stove Damper Fly 1 20-31 Stove Damper Fly Shaft 1 .10 24-31 Damper Fly Shaft Spring 1 .10 24-43 Stove Damper Fly Spring 1 .15 28-4 Connecting Rod Swivel 1 .25 62-5 Escutcheon Pin 1 .05 74-3 Exhaust Shut-off Valve 1 .15 78-4 5/16 Plain Washer 1 .05 81-26 3/8×16 Check Nut 2 .05 82-1 1/16×1/2 Cotter Pin 2 .05 82-3 1/8×3/4 Cotter Pin 3 .05 100-16 Warm Air Stove 1 100-17 Warm Air Stove 1 100-520 Warm Air Stove Assembly 1 1.50 122-503 Damper Lever and Shaft Assembly 1 1.00 122-504 Exhaust Shut-off Lever and Shaft Assembly 1 .40 123-1 Heat Tube Support Ring 1 .10 123-3 Damper Body Packing Stop Ring 1 .10 123-4 Exhaust Damper Body Packing Ring 1 .10 124-1 Heat Tube Collar 4 .20 125-1 Damper Shaft Spring Seat 2 .10 126-2 Heat Tube Outlet 1 .50 126-12 Heat Tube Inlet 1 .50 127-1 Heat Tube Packing 4 .10 127-2 Exhaust Damper Body Packing, per foot 1 .10 128-3 Exhaust Damper Body 1 3.00 128-506 Exhaust Manifold Damper Body and Stove Assembly 1 8.00 163-1 Choker Rod Extension .10 MARVEL CARBURETER DISTRIBUTORS Distributors who carry a complete stock of Carbureters and Parts and who are prepared to overhaul and rebuild Carbureters: Marvel Carbureter Sales Co., 335 Newbury Street, Boston, Mass. Marvel Carbureter Sales Co., 242 West 69th Street, New York, N.Y. Marvel Carbureter Sales Co., 2120 Fourteenth Street, N.W., Washington, D.C. Marvel Carbureter Sales Co., 6520 Carnegie Avenue, Cleveland, Ohio. Marvel Carbureter Sales Co., 1406 McGee Street, Kansas City, Mo. Marvel Carbureter Sales Co., 2119 S. Michigan Avenue, Chicago, Ill. Marvel Carbureter Sales Co., 926-928 E. Washington Street, Indianapolis, Ind. Marvel Carbureter Sales Co., 1138 Broadway, Denver, Colo. Marvel Carbureter Sales Co., 1837 South Flower Street, Los Angeles, Calif. Edwards Warden Motor Parts Co., 309-315 E. Broadway, Salt Lake City, Utah. Fauver-Cavanagh Co., Inc., 46-52 Canfield Avenue E., Detroit, Michigan. McAlpin & Schreiner Co., 1520 Tenth Avenue, Seattle, Washington. Moloney Battery & Ignition Co., 108-110 Wyoming Street, El Paso, Texas. W.S. Nott Company, Second Ave. N. & 3rd Street, Minneapolis, Minn. Distributors who carry a complete stock of Carbureters and Parts: Auto Supply Co., Inc., 1107-1111 Broadway, Nashville, Tenn. Herrick Hardware Co., Waco, Texas. Joseph Schwartz Company, 729-735 St. Charles Street, New Orleans, La. Shelton Motor Company, Abeline, Texas. Wholesale Auto Supply House, 309-311 Washington Street, Tampa, Florida. Westbrook Motor Co., San Antonio, Texas. EXPORT BUSINESS All export business and shipments handled by Overseas Motor Service Corporation, 1760 Broadway, New York, N.Y. [Illustration: THE FLINT PRINTING CO.] 
16130	----	JUDGMENTS OF THE COURT OF APPEAL OF NEW ZEALAND ON PROCEEDINGS TO REVIEW ASPECTS OF THE REPORT OF THE ROYAL COMMISSION OF INQUIRY INTO THE MOUNT EREBUS AIRCRAFT DISASTER C.A. 95/81 In the Court of Appeal of New Zealand--Between Air New Zealand Limited, First Applicant, and Morrison Ritchie Davis, Second Applicant, and Ian Harding Gemmell, Third Applicant, and Peter Thomas Mahon, First Respondent, and the Attorney-General, Fourth Respondent, and New Zealand Airline Pilots Association, Fifth Respondent, and the Attorney-General, Sixth Respondent. _Coram_ Woodhouse P. Cooke J. Richardson J. McMullin J. Somers J. _Hearing_ 5, 6, 7, 8, 9 and 12 October 1981. _Counsel_ L.W. Brown Q.C. and R.J. McGrane for first and second applicants. D.A.R. Williams and L.L. Stevens for third applicant. G.P. Barton and R.S. Chambers for first respondent. C.J. McGuire for fourth respondent (Civil Aviation Division)--leave to withdraw. A.F. MacAlister and P.J. Davison for fifth respondent. W.D. Baragwanath and G.M. Harrison for sixth respondent. _Judgment_ 22nd December 1981. JUDGMENT OF COOKE, RICHARDSON and SOMERS JJ. On 5 August 1981, for reasons then given, this Court ordered that these proceedings be removed as a whole from the High Court to this Court for hearing and determination. They are proceedings, brought by way of application for judicial review, in which certain parts of the report of the Royal Commission on the Mount Erebus aircraft disaster are attacked. In summary the applicants claim that these parts are contrary to law, in excess of jurisdiction and in breach of natural justice. One of the reasons for ordering the removal was that it was important that the complaints be finally adjudicated on as soon as reasonably practicable. We had in mind that the magnitude of the disaster--257 lives were lost--made it a national and indeed international tragedy, so the early resolution of any doubts as to the validity of the report was a matter of great public concern. Also the report contained very severe criticism of certain senior officers of Air New Zealand. Naturally this criticism must have been having damaging and continuing effects, as evidenced for instance by the resignation of the chief executive, so it was right that the airline and the individuals should have at a reasonably early date a definite decision, one way or the other, on whether their complaints were justified. In the event the hearing in this Court was completed in less than six days. We had envisaged that some further days might be required for cross-examination, as there were applications for leave to cross-examine the airline personnel and the Royal Commissioner himself on affidavits that they had made in the proceedings. But ultimately the parties elected to have no cross-examination--and it should be made clear that this was by agreement reached between the parties, not by decision of the Court. With the benefit of the very full written and oral arguments submitted by counsel, the Court is now in a position to given judgment before the end of the year. We must begin by removing any possible misconception about the scope of these proceedings. They are not proceedings in which this Court can adjudicate on the causes of the disaster. The question of causation is obviously a difficult one, as shown by the fact that the Commissioner and the Chief Inspector of Air Accidents in his report came to different conclusions on it. But it is not this Court's concern now. This is not an appeal. Parties to hearings by Commissions of Inquiry have no rights of appeal against the reports. The reason is partly that the reports are, in a sense, inevitably inconclusive. Findings made by Commissioners are in the end only expressions of opinion. They would not even be admissible in evidence in legal proceedings as to the cause of a disaster. In themselves they do not alter the legal rights of the persons to whom they refer. Nevertheless they may greatly influence public and Government opinion and have a devastating effect on personal reputations; and in our judgment these are the major reasons why in appropriate proceedings the Courts must be ready if necessary, in relation to Commissions of Inquiry just as to other public bodies and officials, to ensure that they keep within the limits of their lawful powers and comply with any applicable rules of natural justice. Although this is not an appeal on causation or on any other aspect of the Commission's report, the issues with which this Court is properly concerned--the extent of the Commissioner's powers in this inquiry, and natural justice--cannot be considered without reference to the issues and evidence at the inquiry. We are very conscious that we have not had the advantage of seeing and hearing the witnesses. It can be very real, as all lawyers know. It is true that the kind of analytical argument we heard from counsel, with concentration focused on the passages of major importance in the report and the transcript of evidence, can bring matters into better perspective than long immersion in the details of a case. Necessarily this Court is more detached from the whole matter than was the Commissioner. And several different judicial minds may combine to produce a more balanced view than one can. But as against those advantages, which we have had, there is the advantage of months of direct exposure to the oral evidence, which he had. So we have to be very cautious in forming opinions on fact where there is any room for different interpretations of the evidence. Having stressed those limitations on the role of this Court, we think it best to state immediately in general terms the conclusions that we have reached in this case. Then we will go on to explain the background, the issues and our reasoning in more detail. Our general conclusion is that the paragraph in the report (377) in which the Commissioner purported to find that there had been 'a pre-determined plan of deception' and 'an orchestrated litany of lies' was outside his jurisdiction and contained findings made contrary of natural justice. For these reasons we hold that there is substance in the complaints made by the airline and the individuals. Because of those two basic defects, an injustice has been done, and to an extent that is obviously serious. It follows that the Court must quash the penal order for costs made by the Commissioner against Air New Zealand reflecting the same thinking as paragraph 377. The Disaster In 1977 Air New Zealand began a series of non-scheduled sightseeing flights to the Antarctic with DC10 aircraft. The flights left and returned to New Zealand within the day and without touching down en route. The southernmost point of the route, at which the aircraft turned round, was to be at about the latitude of the two scientific bases, Scott Base (New Zealand) and McMurdo Station (United States), which lie about two miles apart, south of Ross Island. On Ross Island there are four volcanic mountains, the highest being Mount Erebus, about 12,450 feet. To the west of Ross Island is McMurdo Sound, about 40 miles long by 32 miles wide at the widest point and covered by ice for most of the year. It was originally intended that the flight route south would be over Ross Island at a minimum of 16,000 feet. From October 1977, with the approval of the Civil Aviation Division, descent was permitted south of the Island to not lower than 6000 feet, subject to certain conditions concerning weather and other matters. However, the evidence is that the pilots were in practice left with a discretion to diverge from these route and height limitations in visual meteorological conditions; and they commonly did so, flying down McMurdo Sound and at times at levels lower than even 6000 feet. This had advantages both for sightseeing and also for radio and radar contact with McMurdo Station. Moreover from 1978 the flight plan, recording the various waypoints, stored in the Air New Zealand ground computer at Auckland actually showed the longitude of the southernmost waypoint as 164° 48' east, a point in the Sound approximately 25 miles to the west of McMurdo Station. The evidence of the member of the airline's navigation section who typed the figures into the computer was that he must have mistakenly typed 164° 48' instead of 166° 48' and failed to notice the error. Shortly before the fatal flight the navigation section became aware that there was some error, although their evidence was that they understood it to be only a matter of 10 minutes of longitude. In the ground computer the entry was altered to 166° 58' east, and this entry was among the many in the flight plan handed over to the crew for that flight for typing into the computerised device (AINS) on board the aircraft. The change was not expressly drawn to the attention of the crew. The AINS enables the pilot to fly automatically on the computer course ('nav' track) at such times as he wishes. The crash occurred at 12.50 pm on 28 November 1979. The aircraft struck the northern slopes of Mount Erebus, only about 1500 feet above sea level. There were no survivors. The evidence indicates that the weather was fine but overcast and that the plane had descended below the cloud base and was flying in clear air. The pilot, Captain Collins, had not been to the Antarctic before, and of the other four members of the flight crew only one, a flight engineer, had done so. The plane was on nav track. The Chief Inspector of Air Accidents, Mr R. Chippindale, carried out an investigation and made a report to the Minister, dated 31 May 1980, under reg. 16 of the Civil Aviation (Accident Investigation) Regulations 1978. It was approved by the Minister for release as a public document. The Chief Inspector concluded that 'The probable cause of the accident was the decision of the captain to continue the flight at low level toward an area of poor surface and horizon definition when the crew was not certain of their position and the subsequent inability to detect the rising terrain which intercepted the aircraft's flight path'. He adhered to this in evidence before the subsequent Royal Commission. The Royal Commission was appointed on 11 June 1980 to inquire into 'the causes and circumstances of the crash', an expression which was elaborated in terms of reference consisting of paragraphs (a) to (j). Mr. Justice Mahon was appointed sole Commissioner. In his report, transmitted to the Governor-General by letter dated 16 April 1981 and subsequently presented to the House of Representatives by Command of His Excellency and later printed for public sale, the Commissioner found that '... the single dominant and effective cause of the disaster was the mistake made by those airline officials who programmed the aircraft to fly directly at Mt. Erebus and omitted to tell the aircrew'. He exonerated the crew from any error contributing to the disaster. The Commissioner and the Chief Inspector were at one in concluding that the crash has occurred in a whiteout. The Commissioner gave this vivid reconstruction in the course of para. 40 of his report: I have already made it clear that the aircraft struck the lower slopes of Mt. Erebus whilst flying in clear air. The DC10 was at the time flying under a total cloud cover which extended forward until it met the mountain-side at an altitude of somewhere between 2000 and 2500 feet. The position of the sun at the time of impact was directly behind the aircraft, being in a position approximately to the true north of the mountain and shining at an inclination of 34°. The co-existence of these factors produced without doubt the classic 'whiteout' phenomenon which occurs from time to time in polar regions, or in any terrain totally covered by snow. Very extensive evidence was received by the Commission as to the occurrence and the consequences of this weather phenomenon. So long as the view ahead from the flight deck of an aircraft flying over snow under a solid overcast does not exhibit any rock, or tree, or other landmark which can offer a guide as to sloping or uneven ground, then the snow-covered terrain ahead of the aircraft will invariably appear to be flat. Slopes and ridges will disappear. The line of vision from the flight deck towards the horizon (if there is one) will actually portray a white even expanse which is uniformly level. What this air crew saw ahead of them as the aircraft levelled out at 3000 feet and then later at 1500 feet was a long vista of flat snow-covered terrain, extending ahead for miles. Similarly, the roof of the solid overcast extended forward for miles. In the far distance the flat white terrain would either have appeared to have reached the horizon many miles away or, more probably, merged imperceptibly with the overhead cloud thus producing no horizon at all. What the crew could see, therefore, was what appeared to be the distant stretch of flat white ground representing the flat long corridor of McMurdo Sound. In reality the flat ground ahead proceeded for only about 6 miles before it intercepted the low ice cliff which marked the commencement of the icy slope leading upwards to the mountain, and at that point the uniform white surface of the mountain slope proceeded upwards, first at an angle of 13°, and then with a gradually increasing upward angle as it merged with the ceiling of the cloud overhead. The only feature of the forward terrain which was not totally white consisted of two small and shallow strips of black rock at the very bottom of the ice cliff, and these could probably not be seen from the flight deck seats owing to the nose-up attitude of 5° at which the aircraft was travelling, or they were mistaken for thin strips of sea previously observed by the crew as separating blocks of pack ice. The aircraft had thus encountered, at a fateful coincidence in time, the insidious and unidentifiable terrain deception of a classic whiteout situation. They had encountered that type of visual illusion which makes rising white plateaux appear perfectly flat. This freak of polar weather is known and feared by every polar flier. In some Arctic regions in the Canadian and in the north European winter, it is responsible for numbers of light aircraft crashes every year. Aircraft fly, in clear air, directly into hills and mountains. But neither Captain Collins nor First Officer Cassin had ever flown at low altitude in polar regions before. Even Mr Mulgrew [the commentator for the passengers], with his antarctic experience, was completely deceived. The fact that not one of the five persons on the flight deck ever identified the rising terrain confirms the totality of this weird and dangerous ocular illusion as it existed on the approach to Mt. Erebus at 12.50 p.m. on 28 November 1979. Paragraph 165 of the Commissioner's report also merits quotation. We have underlined some of it, indicating that in this particular part of his report the Commissioner seems to accept that when they first heard of the crash the management of the airline must have been unaware of the true nature and danger of a whiteout. If so, they would have had no reason to suppose that the pilot would have elected to fly at such a low level without real visibility. That is an aspect which could well have been strongly relied on if, when giving evidence before the Commissioner, they had realised that they were being accused of trying to cover up the cause of the crash from an early stage: The term 'whiteout' has more than one meaning as being descriptive of weather conditions in snow-covered terrain. For aviation purposes it is often described as the cause of the visual difficulty which occurs when a aircraft is attempting to land during a snowstorm. As already stated, the United States Navy maintains a special whiteout landing area situated to the south of its normal landing strips near McMurdo Station. This area is used when an aircraft, which is committed to a landing, is required to land when visibility is obscured by a snowstorm. The snow in Antarctica is perfectly dry, and a wind of only 20 kilometres can sweep loose snow off the surface and fill the air with these fine white particles. A landing on the special whiteout landing field can be accomplished only by an aircraft equipped with skis or, in the case of an aircraft without skis, then it must make a belly-up landing on this snow-covered emergency airfield. Flying in a 'whiteout' of that description is no different from flying in thick cloud. The pilot cannot know where he is and must land in accordance with strict radio and radar directions. So far as I understand the evidence, I do not believe that either the airline or Civil Aviation Division ever understood the term 'whiteout' to mean anything else than a snowstorm. I do not believe that they were ever aware, until they read the chief inspector's report of the type of 'whiteout' which occurs in clear air, in calm conditions, and which creates this visual illusion which I have previously described and which is, without doubt, the most dangerous of all polar weather phenomena. While largely agreed about the whiteout conditions, the Commissioner and the Chief Inspector took quite different views as to whether the crew had been uncertain of their position and visibility. This disagreement is associated with a major difference as to the interpretation of the tape recovered from the cockpit voice recorder covering the conversation on the flight deck during the 30 minutes before the crash. Both the Commissioner and the Chief Inspector found difficulty in arriving at an opinion about what was said and by whom. Whereas the Chief Inspector thought that the two flight engineers had voiced mounting alarm at proceeding at a low level towards a cloud-covered area, the Commissioner thought that Captain Collins and First Officer Cassin had never expressed the slightest doubt as to where the aircraft was and that 'not one word' was ever addressed by either of the flight engineers to the pilots indicating any doubt. This is not a question on which the present proceedings call for any opinion from this Court, nor are we in any position to give one. A major point in the Commissioner's reasoning, and one that helps to explain the difference between the two reports, is that on the basis of evidence from the wife and two daughters of Captain Collins he accepted that, at home the night before the flight, the Captain had plotted on an atlas and two maps a route of the flight; and he drew the inference that Captain Collins must then have had with him a computer print-out. Any such print-out would have been made before the alteration and consequently would have shown the longitude of the southernmost waypoint as 164° 48' E. The Commissioner accordingly concluded that Captain Collins had plotted a route down the Sound. No doubt this tended to reinforce his view that the Captain, flying on nav track, had never doubted that he was in fact over the Sound. The Challenged Paragraphs The background already given is needed for an understanding of the case. But we repeat that the case is not an appeal from the Commissioner's findings on causation or other matters. The applicants acknowledge that they have no rights of appeal. What they attack are certain paragraphs in the Commission report which deal very largely, not with the causes and circumstances of the crash, but with what the Commissioner calls 'the stance' of the airline at the inquiry before him. The applicants say that in these paragraphs the Commissioner exceeded his powers or acted in breach of natural justice; and further that some of his conclusions were not supported by any evidence whatever of probative value. Their counsel submit that a finding made wholly without evidence capable of supporting it is contrary to natural justice. The arguments on the other side were presented chiefly by Mr Baragwanath and Mr Harrison, who had been counsel assisting the Commission and appeared in this Court for the Attorney-General, not to advance any view on behalf of the Government but to ensure that nothing that could possibly be said in answer to the contentions of Mr Brown and Mr Williams for the applicants was left unsaid before the Court. This was done because it has not been usual for a person in the position of the Commissioner to take an active part in litigation concerning his report. Mr Barton, who appeared for the Commissioner, did not present any argument, adopting a watching role. He indicated that he would only have played an active role if the Commissioner had been required for cross-examination. As already mentioned, it was agreed otherwise. At that stage the Commissioner, by his counsel, very properly stated that he would abide the decision of the Court. Mr Baragwanath's submissions were to the general effect that the Court had no jurisdiction to interfere with the opinions expressed in the Commission's report, which were not 'findings' and bound no one; and that in any event they were conclusions within the Commissioner's powers, open to him on the evidence and arrived at without any breach of natural justice. We now set out the various paragraphs under attack, bearing in mind that they cannot properly be considered in isolation from the context in the report. The paragraphs vary in importance, but it is convenient to take them in the numerical order of the report. We will indicate as regards each paragraph or set of paragraphs the essence of the complaint. After doing this we will state how we propose to deal with the complaints. Destruction of Documents Paragraphs 45 and 54, which affect particularly the chief executive at the time of the crash, Morrison Ritchie Davis, are as follows: 45. The reaction of the chief executive was immediate. He determined that no word of this incredible blunder was to become publicly known. He directed that all documents relating to antarctic flights, and to this flight in particular, were to be collected and impounded. They were all to be put on one single file which would remain in strict custody. Of these documents all those which were not directly relevant were to be destroyed. They were to be put forthwith through the company's shredder. 54. This was at the time the fourth worst disaster in aviation history, and it follows that this direction on the part of the chief executive for the destruction of 'irrelevant documents' was one of the most remarkable executive decisions ever to have been made in the corporate affairs of a large New Zealand company. There were personnel in the Flight Operations Division and in the Navigation Section who anxiously desired to be acquitted of any responsibility for the disaster. And yet, in consequence of the chief executive's instructions, it seems to have been left to these very same officials to determine what documents they would hand over to the Investigating Committee. These paragraphs occur in the context of a discussion of the change in the computer waypoint shortly before the flight and the failure to draw it to the attention of the flight crew. The reference to the chief executive having 'determined that no word of this incredible blunder was to become publicly known' is, taken by itself, at least an overstatement, because in paragraph 48 the Commissioner in effect qualifies it. He says there that it was inevitable that the facts would become known and 'perhaps' the chief executive had only decided to prevent adverse publicity in the meantime. Clearly the airline disclosed to the Chief Inspector that the change of more than two degrees of longitude had been made in the computer early on the day of the flight and not mentioned to the crew; these matters are referred to in paragraphs 1.17.7 and 2.5 of the Chief Inspector's report. They were matters which the Chief Inspector did not highlight; evidently he did not regard them as of major importance. For his part the Commissioner (in para. 48 of his report) states that the Chief Inspector did not make it clear that the computer flight path had been altered before the flight and the alteration not notified to the crew. We are not concerned with whether or not the Commissioner's implied criticism of the Chief Inspector's report is correct. The complaint made by the applicants is that the criticisms of Mr Davis in the two paragraphs that we have set out are based on mistake of fact, not on evidence of probative value. It is also said that he was not given a fair opportunity to put his case in relation to such findings, but what the applicants most stress is the way in which the Commissioner dealt with the evidence. In particular they point out that the evidence of Mr Davis, not contradicted by any other evidence and correctly summarised in paragraph 45 of the Commissioner's report, was that only copies of existing documents were to be destroyed; that he did not want any surplus document to remain at large in case its contents were released to the news media by some employee of the airline; and that his instructions were that all documents of relevance were to be retained on the single file. Their counsel submit in effect that in converting this direction for the preservation of all relevant documents into a direction for the destruction of 'irrelevant' documents--a word used by the Commissioner as if it were a quotation from Mr Davis--the Commissioner distorted the evidence. And it is said that the description 'one of the most remarkable executive decisions every to have been made in the corporate affairs of a large New Zealand company' is, to say the least, far-fetched. Counsel for the applicants point also to the fact that there is no evidence that any document of importance to the inquiry was destroyed in consequence of the instructions given by Mr Davis. The gist of the contrary argument presented by Mr Baragwanath was that Mr Davis was fully cross-examined about his instructions; and that 'it was open to the Royal Commissioner to find that there were in existence documents which never found their way to that file and that the procedures were tailor made for destruction of compromising documents'. Alteration of Flight Plan Paragraph 255 (e) and (f), in numerical order the next passages complained of, refer to the fact that when the co-ordinates in the Auckland computer were altered a symbol was used which had the effect of including in the information to be sent to the United States air traffic controller at McMurdo Station the word 'McMurdo' instead of the actual co-ordinates (latitude and longitude) of the southernmost waypoint. The Commissioner said: (e) When the TACAN position [a navigational aid at McMurdo Station enabling aircraft to ascertain their distance from it] was typed into the airline's ground computer in the early morning of 28 November 1979, there was also made the additional entry to which I have referred, which would result in the new co-ordinates not being transmitted to McMurdo with the Air Traffic Control flight plan for that day. It was urged upon me, on behalf of the airline, that McMurdo Air Traffic Control would consider the word 'McMurdo' as indicating a different position from that appearing on Air Traffic Control flight plans dispatched from Auckland during 1978 and 1979. I cannot for a moment accept that suggestion. First Officer Rhodes made a specific inquiry at McMurdo within a few days of the disaster and ascertained that the destination waypoint of the first Air Traffic Control flight plan for 1979 had been plotted by the United States Air Traffic Control personnel, and there was evidence from the United States witnesses that this would be normal practice. In my view the word 'McMurdo' would merely be regarded, and was indeed regarded, by McMurdo Air Traffic Control as referring to the same McMurdo waypoint which had always existed. In my opinion, the introduction of the word 'McMurdo' into the Air Traffic Control flight plan for the fatal flight was deliberately designed to conceal from the United States authorities that the flight path had been changed, and probably because it was known that the United States Air Traffic Control would lodge an objection to the new flight path. (f) I have reviewed the evidence in support of the allegation that the Navigation Section believed, by reason of a mistaken verbal communication, that the altered McMurdo waypoint only involved a change of 2.1 nautical miles. I am obliged to say that I do not accept that explanation. There were certainly grave deficiencies in communication within the Navigation Section, but the high professional skills of the Navigation Section's staff entirely preclude the possibility of such an error. In my opinion this explanation that the change in the waypoint was thought to be minimal in terms of distance is a concocted story designed to explain away the fundamental mistake, made by someone, in failing to ensure that Captain Collins was notified that his aircraft was now programmed to fly on a collision course with Mt. Erebus. These paragraphs are attacked on the grounds, in short, that the members of the navigation section said to be adversely affected by them--according to the applicants, Mr R. Brown as regards (e) and Messrs Amies, Brown, Hewitt and Lawton as regards (f)--were not given a fair opportunity of answering the findings or allegations. To understand this complaint one needs a clear picture of what it was that the Commission found or alleged against the navigation section. When studying the report as a whole we have encountered difficulties in this regard, difficulties not altogether removed when we explored them during the argument with Mr Baragwanath. But our understanding is that in essence the Commissioner suggests that the original change of the southernmost point to one in the Sound, 25 miles west of McMurdo Station, was probably deliberate on the part of the navigation section (although he refrained from a definite finding) and that in November 1979 they deliberately made a major change back to the vicinity of McMurdo Station but deliberately set out to conceal the change from the American personnel there. The motive for the 1979 change ascribed by the Commissioner to the navigation section appears to be that they considered that the New Zealand Civil Aviation Division had only approved a route over Mount Erebus, yet at the same time that the American 'authorities' would object to that route, regarding the route down the Sound as safer. In short the theory (if we understand it correctly) is that the navigation section were in a dilemma as there was no route approved by all concerned. Beyond argument, it would seem, there was slipshod work within the airline in the making of the change and the failure to expressly notify flight crews. But the allegations of deliberate concealment and a concocted story are another matter. The complaint is that they were never put squarely to the members of the navigation section. The Commissioner himself did put to the chief navigator, Mr Hewitt, that 'Someone may suggest before the inquiry is over' that the word 'McMurdo' was relayed to McMurdo to conceal a long-standing error in the co-ordinates. Mr Hewitt replied 'Certainly not, sir' and there, the applicants point out, the matter was left, without further questions to witnesses by anyone or any reference in counsel's final submissions. On the other hand Mr Baragwanath urged in substance that the witnesses from the navigation section must have understood that their evidence was under suspicion; that they had ample opportunities to explain how and why any mistakes occurred; and that it was for the Commissioner to assess their explanations, taking into account any impressions they made on him individually as witnesses. Captain Eden First Officer Rhodes, an accident inspector, had been one of the party who went to the Antarctica very shortly after the crash. He was representing the Air Line Pilots Association as well as working with others in the party. When he first gave evidence at the inquiry he was called by counsel for the association. Apparently concern was felt by the airline that some of his evidence might be taken to reflect on Captain Gemmell (the Flight Manager, Technical, and former Chief Pilot) so First Officer Rhodes was recalled as a witness by counsel for the airline. He said that he had 'no reason to doubt Captain Gemmell in any way shape or form'. There was some cross-examination by counsel for the association but no reference was made to Captain Eden in any of the questions. The Commissioner said in paragraph 348 of his report: 348. Captain Eden is at present the director of flight operations for the airline. He appeared in the witness box to be a strong-minded and aggressive official. It seemed clear from this further production of First Officer Rhodes as a witness that it had been suggested to him by Captain Eden that he should either make a direct allegation against Captain Gemmell or else make no allegation at all, and that since First Officer Rhodes seemed to have no direct evidence in his possession, he was therefore obliged to give the answer which Captain Eden had either suggested or directed. However, First Officer Rhodes was not entirely intimidated because as will be observed from the evidence just quoted, he insisted on saying that Captain Gemmell had brought an envelope containing documents back to Auckland. Exception is taken to that paragraph as making findings of intimidation against Captain Eden without any such allegation ever having been put to him. Captain Eden gave evidence later in the inquiry than First Officer Rhodes and the transcript shows that he was asked nothing by anyone about their discussion. Captain Gemmell The following paragraphs of the report are attacked for their references to this senior officer: 352. As to the ring-binder notebook, it had been returned to Mrs Collins by an employee of the airline, but all the pages of the notebook were missing. Captain Gemmell was asked about this in evidence. He suggested that, the pages might have been removed because they had been damaged by kerosene. However, the ring-binder notebook itself, which was produced at the hearing, was entirely undamaged. 353. After the evidence given before the Commission had concluded, I gave some thought to the matters just mentioned. I knew that the responsibility for recovering all property on the crash site lay exclusively with the New Zealand Police Force, and that they had grid-searched the entire site. All property recovered had been placed in a large store at McMurdo Base, which was padlocked, and access to the shed was only possible through a senior sergeant of Police. I asked counsel assisting the Commission to make inquiries about the flight bags which had been located on the site but which had not been returned to Mrs Collins or Mrs Cassin. 354. The Royal New Zealand Air Force helicopter pilot who flew the property from the crash site to McMurdo remembered either one or two crew flight bags being placed aboard his helicopter, and he said that they were then flown by him to McMurdo. This was independently confirmed by the loadmaster of the helicopter, who recollected seeing the flight bags. The senior sergeant of Police in charge of the McMurdo store was spoken to, and he recollected either one or two flight bags among other property awaiting packing for return to New Zealand. He said that personnel from Air New Zealand had access to the store, as well as the chief inspector, and the senior sergeant said that he thought that he had given the flight bags to the chief inspector and that the chief inspector was the sole person to whom he had released any property. The chief inspector was then interviewed on 11 December 1980 by telephone, being at that time in Australia, but he said that no flight bags were ever handed to him. ... 359. The following facts seemed to emerge: (1) The two flight bags were lodged in the Police store at McMurdo and would have been returned in due course to Mrs Collins and Mrs Cassin by the Police. But they were taken away from the store by someone and have not since been seen. ... These paragraphs followed a discussion by the Commissioner of a submission by counsel for the Pilots Association that a number of documents which would have tended to support the proposition that Captain Collins had relied upon the incorrect co-ordinates had not been located; and in that context the Commissioner recorded Captain Gemmell's denial that he had recovered any documents relevant to the flight which had not been handed over to the chief inspector. There was also a reference shortly afterwards in the report to Captain Gemmell having brought back some quantity of documents with him from Antarctica. On its own this would be innocuous, but it is part of a context which could lead to inferences adverse to Captain Gemmell being drawn from the paragraphs complained of. The applicants say that there was a mistake of fact, no evidence of probative value and no fair opportunity to answer the criticisms or findings which they claim to be implicit in these paragraphs. The last point, the natural justice one, has a special feature in the case of Captain Gemmell. The applicants say that the findings, apart from one made under mistake (paragraph 352), were based on information or evidence gathered by the Commissioner after the public hearings; and that, while an opportunity of meeting the new matter was given to the Chief Inspector of Air Accidents, none was given to Air New Zealand or Captain Gemmell. Another special feature is that the Commissioner himself ultimately concluded (paragraph 360) 'However, there is not sufficient evidence to justify any finding on my part that Captain Gemmell recovered documents from Antarctica which were relevant to the fatal flight, and which he did not account for to the proper authorities'. Alleged 'Orchestration' We now come to the most serious complaint. It concerns paragraph 377 of the report, a paragraph building up to a quotable phrase that has become well known in New Zealand and abroad: 377. No judicial officer ever wishes to be compelled to say that he has listened to evidence which is false. He always prefers to say, as I hope the hundreds of judgments which I have written will illustrate, that he cannot accept the relevant explanation, or that he prefers a contrary version set out in the evidence. But in this case, the palpably false sections of evidence which I heard could not have been the result of mistake, or faulty recollection. They originated, I am compelled to say, in a pre-determined plan of deception. They were very clearly part of an attempt to conceal a series of disastrous administrative blunders and so, in regard to the particular items of evidence to which I have referred, I am forced reluctantly to say that I had to listen to an orchestrated litany of lies. The applicants claim that these findings were not based on evidence of probative value and that the affected employees were not given a fair opportunity of answering such charges. The general allegation in the statement of claim that the findings attacked were made in excess of jurisdiction has in our view a special bearing on this paragraph. The applicants say that the paragraph affects a considerable number of employees--namely Mr Amies, Mr R. Brown, Mr Davis, Captain Eden, Captain Gemmell, Captain Grundy, Captain Hawkins, Mr Hewitt, Captain Johnson and Mr Lawton. These include all the employees affected by the other paragraphs under challenge. We accept that reasonable readers of the report would take from it that the conspiracy which the Commissioner appears to postulate in his references to 'a pre-determined plan of deception' and 'an orchestrated litany of lies' was seen by him as so wide as to cover all those persons. Paragraph 377 is the culmination of a series of paragraphs beginning with paragraph 373 and separately headed by the Commissioner 'The Stance adopted by the Airline before the Commission of Inquiry'. They include specific references to the chief executive, described as 'very able but evidently autocratic' in the context of an allusion to what 'controlled the ultimate course adopted by the witnesses called on behalf of the airline'. There are also specific references to the executive pilots and members of the navigation section. It is possible that some individual witnesses did give some false evidence during this inquiry. The applicants accept that this was for the Commissioner to consider and that it is not for us to interfere with his assessment of witnesses. But the complaint goes much further than that. It is that there is simply no evidence on which he could find a wholesale conspiracy to commit perjury, organised by the chief executive, which is what this part of the report appears to suggest. Our conclusion that here the Commissioner went beyond his jurisdiction and did not comply with natural justice--a conclusion to be explained more fully later in this judgment--makes it unnecessary for us to decide whether there was any evidence that could conceivably warrant such an extreme finding. It is only right to say, however, that if forced to decide the question we would find it at least difficult to see in the transcript any evidence of that kind. The language of paragraph 377 has evidently been carefully selected for maximum colour and bite, and the Commissioner has sought to reinforce its impact by bringing in his status and experience as a judicial officer. While unfortunate, it is no doubt that result of a search for sharp and striking expression in a report that would be widely read. He cannot have overstated the evidence deliberately. Similarly at senior management level in Air New Zealand there would have been a natural tendency to try to have the company's case put in as favourable a light as possible before the Commission; but it was adding a further and sinister dimension to their conduct to assert that they went as far as organised perjury. Costs The applicants ask for an order quashing one of the Commissioner's decisions as to costs. The decision in question and the reasons for it are stated in an appendix to the report: ... I asked the airline for its submissions on the question of costs. The general tenor of the submissions is that the establishment of this Royal Commission was directed by the New Zealand Government and that the airline should not be ordered to meet any part of the public expenditure so incurred. As a statement of general principle, this is correct. But there is specific statutory power to order that a party to the inquiry either pay or contribute towards the cost of the inquiry, and that the power should be exercised, in my opinion, whenever the conduct of that party at the hearing has materially and unnecessarily extended the duration of the hearing. This clearly occurred at the hearings which took place before me. In an inquiry of this kind, an airline can either place all its cards on the table at the outset, or it can adopt an adversary stance. In the present case, the latter course was decided upon. The management of the airline instructed its counsel to deny every allegation of fault, and to counter-attack by ascribing total culpability to the air crew, against whom there were alleged no less than 13 separate varieties of pilot error. All those allegations, in my opinion, were without foundation. Apart from that, there were material elements of information in the possession of the airline which were originally not disclosed, omissions for which counsel for the airline were in no way responsible, and which successively came to light at different stages of the Inquiry when the hearings had been going on for weeks, in some cases for months. I am not going to burden this recital with detailed particulars, but I should have been told at the outset that the flight path from Hallett to McMurdo was not binding on pilots, that Captain Wilson briefed pilots to maintain whatever altitudes were authorised by McMurdo Air Traffic Control, that documents were ordered by the chief executive to be destroyed, that an investigation committee had been set up by the airline in respect of which a file was held, and that one million copies of the Brizindine article had been printed, a fact never revealed by the airline at all. So it was not a question of the airline putting all its cards on the table. The cards were produced reluctantly, and at long intervals, and I have little doubt that there are one or two which still lie hidden in the pack. In such circumstances the airline must make a contribution towards the public cost of the Inquiry. ... 6. The costs incurred by the Government in respect of this Inquiry have been calculated by the Tribunals Division of the Department of Justice at $275,000. A substantial liability for the burden of such costs must lie upon the State but in my opinion the State ought to be in part reimbursed in respect of the cost to the public of the Inquiry, and I accordingly direct that Air New Zealand Limited pay to the Department of Justice the sum of $150,000 by way of contribution to the public cost of the Inquiry. The order is in any event invalid because the amount is far greater than the maximum allowed by the long out-of-date but apparently still extant scale prescribed in 1903 (1904 Gazette 491). It is only fair to the Commissioner to say that the scale seems never to have been drawn to his attention by any counsel, although he gave an opportunity to make submissions on costs. But there is a deeper objection to the validity of the order, to which we will come shortly. Conclusions Having set out the various complaints we now state our conclusions more specifically than in the earlier part of this judgment. As to the jurisdiction of the Court in the present proceedings, the application is made solely under the Judicature Amendment Act 1972. Under that Act a decision cannot be set aside unless it was made in exercise of a statutory power and _either_ it could have been quashed in certiorari proceedings at common law--that is the effect of s. 4 (1)--_or_ the applicant is entitled to a declaration that it was unauthorised or invalid, in which case s. 4 (2) empowers the Court to set aside the decision instead. The Erebus Commission, like others in the past in New Zealand when a Supreme Court Judge has been the Chairman or the sole Commissioner, was expressed to be appointed both under the Letters Patent delegating the relevant Royal Prerogative to the Governor-General and under the authority of and subject to the provisions of the Commissions of Inquiry Act 1908. Some of us have reservations on various legal questions--whether the Commission had statutory authority for its inquiry as well as Prerogative authority; whether the findings in the body of the report amounted to 'decisions', whether complete absence of evidence is relevant in considering natural justice or can be redressed in proceedings of this kind. These questions may be of more importance in cases concerning the Thomas Commission which are to come before this Court next year. Moreover, though most important in principle, they are highly technical. It seems to us preferable that the Court should not determine them now unless it is essential to do so. And we do not think it is essential, because we are agreed on what now follows and it enables substantial justice to be done in the present case. It is established in New Zealand that in appropriate proceedings the Courts may prevent a Commission of Inquiry--whether a Royal Commission, a statutory Commission or perhaps a combination of the two--from exceeding its powers by going outside the proper scope of its inquiry. That basic principle was clearly accepted by this Court in _Re Royal Commission on Licensing_ 1945 N.Z.L.R. 665. See especially the judgment of Myers C.J. at pp. 678 to 680. As he indicated, the principle is implicit in the judgment of the Privy Council in _Attorney-General for Commonwealth of Australia v. Colonial Sugar Company_ 1914 A.C. 237. It is also clear that in a broad sense the principles of natural justice apply to Commissions of Inquiry, although what those principles require varies with the subject-matter of the inquiry. The leading authority is the decision of this Court in _Re Royal Commission on State Services_ 1962 N.Z.L.R. 96. In recent times Parliament has shown an increasing concern that natural justice should be observed by Commissions. In 1958 s. 4A was inserted in the Commissions of Inquiry Act 1908, expressly giving any person interested in the inquiry, if he satisfied the Commission that he had an interest apart from any interest in common with the public, a right to appear and be heard as if he had been cited as a party. Then in 1980, just as the Erebus Commission was about to start, the section was replaced and strengthened. The main changes made are that any person who satisfies the Commission that any evidence given before it may adversely affect his interests must be given an opportunity to be heard in respect of the matter to which the evidence relates; and every person entitled to be heard may appear in person or by his counsel or agent. In giving this right to representation by counsel the Legislature has gone further than observations made in this Court in the _State Services_ case at pp. 105, 111 and 117. Some statements in the judgments in that case are very relevant to the present case. They are also entirely consistent with the spirit of the changes made by Parliament in 1980. Gresson P. at p. 105 and North J. at p. 111 both gave an inquiry into a disaster as an example of the kind of inquiry where the requirements of natural justice would be more extensive than in inquiries into a general field. Cleary J. stressed at p. 117 that, while Commissions have wide powers of regulating their own procedure, there is the one limitation that persons interested (i.e. apart from any interest in common with the public) must be afforded a fair opportunity of presenting their representations, adducing evidence, _and meeting prejudicial matter_. In both the _Licensing_ and the _State Services_ cases the Commissions were presided over by Supreme Court Judges. It is implicit in the judgments that this status on the part of the Chairman does not emancipate a Commission from judicial review on jurisdictional or natural justice grounds. We hold that the position can be no different when a High Court Judge is sole Commissioner. He will, however, have the powers, privileges and immunities mentioned in s. 13 (1) of the Commissions of Inquiry Act. For instance he will have immunity from defamation actions. A further important point, clear beyond argument, is that an order for costs made by a Commission under s. 11 of the Commissions of Inquiry Act is the exercise of a statutory power of decision within the meaning of the Judicature Amendment Act 1972. Accordingly it is subject to judicial review. The judgments in this Court in _Pilkington_ v. _Platts_ 1925 N.Z.L.R. 864 confirm that if an order for costs has been made by a Commission acting without jurisdiction or failing to comply with procedural requirements the Court will by writ or prohibition or other appropriate remedy prevent its enforcement. We add that, notwithstanding an argument by Mr Harrison to the contrary, we are satisfied that s. 11 was the only possible source of the Commissioner's power to award costs and s. 13 was not and could not have been invoked. The order for costs under challenge in the present case is the Commissioner's order that Air New Zealand pay $150,000 by way of contribution to the public cost of the inquiry. In our view there can be no doubt that this order is and was intended to be, in the words of Williams J. delivering the judgment of this Court in _Cock_ v. _Attorney-General_ (1909) 28 N.Z.L.R. 405. 421, '... in fact, though not in name, a punishment'. What is more important, although Mr Baragwanath argued otherwise we have no doubt that reasonable readers of the report would understand that this order is linked with and consequential upon the adverse conclusions stated by the Commissioner in the section of the report headed by him 'The Stance adopted by the Airline before the Commission of Inquiry'. It is true that the reasons for the costs order open with a proposition about unnecessarily extending the hearing. But the passage develops and the later reasons go further. The words chosen convey that the punishment was not simply for prolonging the hearing. In particular the statements about cards in the pack are a reversion to the theme of the 'Stance' section, with its exceedingly strong allegations in paragraph 377 of 'a pre-determined plan of deception' and 'an orchestrated litany of lies'. Applying the well-settled principles already mentioned, we think that if in making those statements the Commissioner exceeded his terms of reference or acted in violation of natural justice, the costs order is not realistically severable from that part of the report and should be quashed. For the purposes of the present case that is sufficient to dispose of the argument based on _Reynolds_ v. _Attorney-General_ (1909) 29 N.Z.L.R. 24 that after a Commission has reported it is functus officio and beyond the reach of certiorari or prohibition. Naturally the stance of the airline at the inquiry directed by the terms of reference was not included expressly in those terms. The argument presented in effect for the Commissioner on the question of jurisdiction is that comments, however severe, on the veracity and motives of witnesses were incidental to the carrying out of the express terms. We accept unhesitatingly that what is reasonably incidental is authorised (as was recognised in _Cock's_ case at p. 425) and also that to some degree any Commission of Inquiry has the right to express its opinion of the witnesses, much as a Court or statutory tribunal has that right. But we think that it is a matter of degree. For present purposes it is not necessary to decide whether the law of New Zealand is still, as held in _Cock's_ case, that a Commission of Inquiry cannot lawfully be constituted to inquire into allegations of crime. That issue may be raised more directly by the litigation regarding the Thomas Commission. The issue now to be decided is whether the Commissioner had powers, implied as being reasonably incidental to his legitimate functions of inquiry into the causes and circumstances of the crash, to make assertions amounting to charges of conspiracy to perjure at the inquiry itself. In considering that issue the importance of not unreasonably shackling a Commission of Inquiry has to be weighed. It is also material, however, that such a charge is calculated to attract the widest publicity, both national and international. It is scarcely distinguishable in the public mind from condemnation by a Court of law. Yet it is completely without the safeguards of rights to trial by jury and appeal. In other words, by mere implication any Commission of Inquiry, whatever its membership, would have authority publicly to condemn a group of citizens of a major crime without the safeguards that invariably go with express powers of condemnation. We are not prepared to hold that the Commissioner's implied powers went so far. We hold that he exceeded his jurisdiction in paragraph 377. If, contrary to the view just expressed, the Commissioner did have jurisdiction to consider allegations of organised perjury, natural justice would certainly have required that the allegations be stated plainly and put plainly to those accused. That was not done. If it had been done, what we have said earlier is enough to show that they could well have made effective answers. So we conclude that in making the findings or allegations stated in paragraph 377 of the report the Commission acted in excess of jurisdiction and contrary to natural justice. As previously mentioned, the conspiracy postulated in paragraph 377 is evidently intended to include as participants the chief executive of the airline, the executive pilots and members of the navigation section. If the order for $150,000 costs is quashed on the ground that the statements about a pre-determined plan of deception and an orchestrated litany of lies were made without jurisdiction and contrary to natural justice, we think that substantial justice will be done to the company and those individuals. In our opinion that costs order must be quashed on those grounds as well as on the ground that it was invalid as to amount. Further, during the proceedings in this Court there occurred developments which in themselves threw a different light on matters dealt with in the paragraphs under attack affecting Captain Gemmell particularly. These should be publicly recorded. It was acknowledged by all parties, including the Commissioner, that the reference to Captain Gemmell in paragraph 352, concerning a notebook belonging to Captain Collins, was a mistake. The Commissioner evidently had in mind some evidence given by Captain Crosbie, the welfare officer of the Air Line Pilots Association. This disposes of any inference against Captain Gemmell that might be taken from that paragraph. Much the same applies to the other paragraphs affecting him which are complained of. We have set them out in full and it will be seen that they all relate to two flight bags. It had seemed that paragraph 359 (1), in its context, might have conveyed the impression that Captain Gemmell had removed these bags from the McMurdo store and brought them or their contents back from Antarctica. At our hearing, however, Mr Davison, who was one of the counsel for the Pilots Association both before the Commission and in this court, made it clear responsibly and fairly that this is not suggested. As to Captain Eden, it has already been stated that the transcript shows that the allegation expressed or implied in paragraph 348 was never put to him. Having said so plainly, we need only add as regards this particular complaint that the allegation, although it would naturally have caused concern to Captain Eden and Air New Zealand, was not as serious as the others that are complained of. Whether the Court has jurisdiction to quash particular passages in the report in addition to the costs order is a difficult and technical question. We prefer not to lengthen this judgment with an unnecessary discussion of it. In modern administrative law, as a result of developments in both case and statute law, the power of the Courts to grant declarations and quash decisions is wider than was thought in the _Reynolds_ case in 1909 (29 N.Z.L.R. at 40). It may be that in a sufficiently clear-cut case the jurisdiction, either under the Act or at common law, will be found to extend to parts of Commission reports even when they are not linked with costs orders. But in the end that jurisdictional question does not have to be decided in this case, and we reserve our opinion on it. If the jurisdiction does go so far, it must be discretionary, as the grant of declarations always is. The Court would have to be satisfied that grounds so strong as to require it to act in that unusual way had been made out. In our opinion they would be made out clearly enough as regards paragraph 377, which stands out from the general body of the report. But the quashing of the costs order because of its association with that paragraph is enough to do justice there. The position is less clear as regards the other paragraphs complained of. For various reasons they are all in a marginal category. What has been said in this judgment may help to enable them to be seen in perspective. On balance we would not be prepared to hold that as to these other paragraphs the applicants have made out a sufficiently strong case to justify this Court in interfering, assuming that there is jurisdiction to do so. In the result, the application for review having succeeded on the main issue, we see no need to and are not prepared to go further in granting relief. Our decision is simply that the $150,000 costs order be quashed on the grounds already stated. As to the costs of the present proceedings, they should be reserved, as there has been no argument on the matter. _Solicitors_ Russell McVeagh McKenzie Bartleet & Co., Auckland, for First and Second Applicants. Sheffield Young & Ellis, Auckland, for Third Applicant. Crown Law Office, Wellington, for First, Fourth and Sixth Respondents. Keegan Alexander Tedcastle & Friedlander, Auckland, for Fifth Respondent. C.A. 95/81 In the Court of Appeal of New Zealand--Between Air New Zealand Limited. First Appellant, and Morrison Ritchie Davis, Second Appellant, and Ian Harding Gemmell, Third Appellant, and Peter Thomas Mahon, First Respondent, and the Attorney-General, Fourth Respondent, and New Zealand Airline Pilots Association, Fifth Respondent, and the Attorney-General, Sixth Respondent. _Coram_ Woodhouse P. Cooke J. Richardson J. McMullin J. Somers J. _Hearing_ 5th-12th October 1981. _Counsel_ L.W. Brown, Q.C., for first and second appellants, with R.J. McGrane. D.A.R. Williams for third appellant, with L.L. Stevens. G.P. Barton for first respondent, with R.S. Chambers. C.J. McGuire for fourth respondent (Civil Aviation Division)--leave to withdraw. A.F. MacAlister for fifth respondent, with P.J. Davison. W.D. Baragwanath for sixth respondent, with G.M. Harrison. _Judgment_ 22 December 1981 JUDGMENT OF WOODHOUSE P. AND McMULLIN J.--DELIVERED BY WOODHOUSE P. On 28th November 1979 a DC10-30 aircraft owned and operated by Air New Zealand Limited crashed during daylight hours at a point 1465 feet above mean sea level on the ice-covered lower slopes of Mount Erebus in the Antarctic. It was a tragedy in which 257 lives were lost. The magnitude of the disaster resulted in two separate investigations into the causes of and circumstances surrounding the accident. The second inquiry took the form of a Royal Commission appointed by Letters Patent and also pursuant to the provisions of the Commissions of Inquiry Act 1908. Mr Justice Mahon, a Judge of the High Court at Auckland, was appointed sole Commissioner on 11th June 1980. He prepared the Commission's Report and presented it on 16th April 1981. The case now before this Court is entirely concerned with that Report. But lest there be any misunderstanding it is necessary to emphasize at the outset that no attack can be or indeed has been made upon the conclusions it reaches as to the cause of the crash. Instead the proceedings are brought by way of judicial review under the Judicature Amendment Act 1972 in order to challenge statements in the Report about the conduct of certain officers of Air New Zealand. Senior officers of the airline are severely criticized in the Report and in one paragraph on the basis of "a pre-determined plan of deception ... to conceal a series of disastrous administrative blunders ... an orchestrated litany of lies". These findings are challenged on grounds that they were made unfairly, in disregard of basic principles of natural justice and without jurisdiction. We are satisfied that those complaints of the applicants are justified and that the statements should never have been made. It was done without authority of the terms of reference of the Commission and without any warning to the officers affected. Thus they were given no opportunity at all to answer and deny as they claim in affidavits now before this Court they were in a position to do. Because of the view we take of some aspects of the facts and of the law we would be prepared to go further than the other members of the Court in regard to the formal order to be made in this case. We also find it necessary to go further in our conclusions in regard to a number of matters of fact. We feel sure, however, that reputation can be vindicated and the interests of justice met by the formal decision of this Court which will have the effect of quashing a penal order of the Commissioner requiring Air New Zealand to pay the large sum of $150,000 as costs in the Royal Commission Inquiry. The Two Inquiries Before the Royal Commission was appointed and began its work a statutory investigation had already been carried out in terms of the Civil Aviation (Accident Investigation) Regulations 1978. Immediately it was known that the aircraft had crashed on Mount Erebus the standard procedures for aircraft accident investigation were invoked by the Chief Inspector of Air Accidents, Mr R. Chippindale. And he arrived in the Antarctic with a small team of experts on the day following the disaster. They included mountaineers, police, surveyors, the chief pilot of Air New Zealand (Captain Gemmell), and a representative of the Airline Pilots Association, named in the present proceedings as the fifth respondent (First Officer Rhodes). Mr Chippindale conducted intensive inquiries at the site of the crash and instructed that all reasonable steps were to be taken to recover equipment that would bear upon the cause of the accident and any documents which were still accessible before they were blown away into crevasses or covered with snow. Two important items were soon discovered: the cockpit voice recorder was found at once and after a period of systematic digging into the snow the digital flight data recorder was recovered as well. The first piece of equipment provided a tape recording of much that was said on the flight deck during a period of 30 minutes preceding the time of the collision with the ice slope. The second, often described as the "black box", provided conclusive information concerning course, altitude, and other data relating to the flight and functioning of the aircraft at the relevant period of time. Mr Chippindale continued his investigation in New Zealand where he inspected records gathered from the airline. He also interviewed pilots and other officers with relevant information. In addition he travelled overseas. At that point he prepared an interim report so that he could give notice of his tentative findings to all those whom he felt might have some degree of responsibility for the accident. Thus the airline and representatives of the deceased pilots and others were given an opportunity to provide any appropriate answer to the chief inspector before he completed his final report. All this was attended to and his report, which is dated 31st May 1980, was made available to the Minister of Transport on 3rd June 1980. The Minister then approved the report for release as a public document on 12th June 1980. As mentioned, the Royal Commission was appointed for the purpose of conducting a public inquiry at that same time. There is a difference in the two reports upon the cause of the accident. Mr Chippindale considered the probable cause to have been pilot error. On the other hand the Royal Commission exonerated the pilots completely and spoke instead of "incompetent administrative airline procedures". Since this case is concerned with allegations by the Commissioner that the affected officers of Air New Zealand had engaged "in a pre-determined plan of deception ... to conceal a series of disastrous administrative blunders" (administrative mistakes which he himself had found to be the real cause of the disaster) it is not unimportant to ask what relevant information the airline had actually been able to provide which was not supplied to Mr Chippindale. For that last reason the material made available for consideration by Mr Chippindale deserves some examination. An example concerns the change made to the final stage of the computer flight track to the Antarctic which the Commissioner regarded as a central reason for the accident. During a period of fourteen months prior to the fatal flight Air New Zealand's ground computer had contained an incorrect geographical reference to the southern waypoint of the journey at McMurdo. Accordingly, in that period it was shown incorrectly on any computer print-outs of the flight plan. But a few hours before departure of the DC10 an amendment was made and the flight crew was not informed that amended co-ordinates (since their briefing 19 days earlier) had thus been fed into the aircraft's computer. In paragraph 44 the Report explains that the chief executive of the airline was told of this matter on 30th November. Then in paragraph 45 it is said that the chief executive "determined that no word of this incredible blunder was to become publicly known". There follows a statement that a direction was thereupon given "that all documents relating to Antarctic flights, and to this flight in particular, were to be collected and impounded. They were all to be put on one single file which would remain in strict custody. Of these documents all those which were not directly relevant were to be destroyed". The reference in this context to the amendment to the co-ordinates invites the question as to whether Mr Chippindale had been given that particular information by the airline during his own investigation. It is made plain in his own report that this had been done immediately. He himself was not uncritical of the administrative work of the airline as it touched upon the fatal flight and concerning this matter he said: "3.5 The flight planned route entered in the company's base computer was varied after the crew's briefing in that the position for McMurdo on the computer printout used at the briefing, was incorrect by over 2 degrees of longitude and was subsequently corrected prior to this flight." The variation in the computer _after the crew of the DC10 had been briefed_ (as Mr Chippindale realized) is the matter which is mentioned by the Commissioner in paragraph 44 and which in paragraph 45 is offered as the motive for what is there described as an immediate decision by the chief executive that no word of the matter was to become publicly known, with documents to be impounded and others destroyed. This information was given into Mr Chippindale's hands by Air New Zealand in a written statement on the day following his return from the crash site in Antarctica. The Chippindale report then states in paragraph 3.6 that the computer error had remained in the flight plans for some fourteen months. Then it is said: "3.7 Some diagrams and maps issued at the route qualification briefing could have been misleading in that they depicted a track which passed to the true west of Ross Island over a sea level ice shelf, whereas the flight planned track passed to the east over high ground reaching to 12450 feet AMSL. 3.8 The briefing conducted by Air New Zealand Limited contained omissions and inaccuracies which had not been detected by either earlier participating aircrews or the supervising Airline Inspectors." So these various matters (also mentioned by the Commissioner) were well within Mr Chippindale's knowledge. However he came to a final conclusion that pilot error had been involved as a probable cause of the accident while the Commissioner (who decided this was an incorrect finding) was satisfied instead that the cause of the accident was not pilot error at all. He said: "393. In my opinion therefore, the single dominant and effective cause of the disaster was the mistake made by those airline officials who programmed the aircraft to fly directly at Mt. Erebus and omitted to tell the aircrew. That mistake is directly attributable, not so much to the persons who made it, but to the incompetent administrative airline procedures which made the mistake possible. 394. In my opinion, neither Captain Collins nor First Officer Cassin nor the flight engineers made any error which contributed to the disaster, and were not responsible for its occurrence." Jurisdiction to Review Several important questions arise in this case. Is there jurisdiction in the Courts to review in such a context as this taking into account the ambit of ss. 3 and 4 of the Judicature Amendment Act 1972? And if there is such power is it by reason of the award of costs in this case? Or on grounds relating to excess of jurisdiction on the part of the Commissioner? Or considerations of natural justice? Or by reference to all three of those matters? For the reasons that follow we are satisfied that the findings are reviewable and that each one of those three matters is properly within the scope of the Court's jurisdiction. As already mentioned, the proceedings are by way of application for review under the Judicature Amendment Act 1972 and are directed against certain findings in the Report, to which we have referred. The applicants claim that those findings are invalid, in excess of jurisdiction or made in circumstances involving unfairness or breach of natural justice. They seek declarations to that effect and orders setting aside the findings and quashing the order that Air New Zealand pay $150,000 as a contribution to the public cost of the inquiry. It is necessary to consider whether under the Act the Court has jurisdiction to grant such relief in this case. By ss. 3 and 4 of the Act relief may be granted only where a "statutory power" is involved. That term includes a "statutory power of decision". Since liberalizing amendments made in 1977, "statutory power" includes power conferred by or under any Act "to make any investigation or inquiry into the rights, powers, privileges, immunities, duties, or liabilities of any person" and "statutory power of decision" includes power conferred by or under any Act "to make a decision ... affecting" any such rights, powers, privileges, duties or liabilities. Generally the relief available is confined by s. 4 to that which the applicant would have been entitled to in any one or more of the proceedings for mandamus, prohibition, certiorari, declaration or injunction; but there is a relevant exception in s. 4 (2) whereby if the applicant is entitled to an order declaring that a decision made in the exercise of a statutory power of decision is unauthorized or otherwise invalid the Court may set aside the decision instead. The first question as to jurisdiction is therefore whether, apart from the 1972 Act, the applicants could have obtained relief by any of the proceedings mentioned. The Commission having ceased to exist, it would be too late to apply for prohibition or an injunction against the first respondent and mandamus would also be inappropriate. The decision of this Court in _Reynolds_ v. _Attorney-General_ (1909) 29 N.Z.L.R. 24, 37-38, suggests that once the report has been forwarded to the Governor-General it may be permanently beyond the reach of certiorari; this is perhaps a corollary of the view, to which we referred in the judgment concerning discovery in _Environmental Defence Society Inc._ v. _South Pacific Aluminium Limited_ (C.A. 59/81, judgment 15th June 1981), that a prerogative remedy may not lie against the Sovereign's representative. But we need not go further into the rather technical question of the scope of certiorari in this kind of case. As has been said in the _Environmental Defence Society_ case and _Ng_ v. _Minister of Immigration_ (C.A. 100/81, judgment 10th August 1981), a declaration may be granted in the discretion of the Court whether or not certiorari would have lain. That a declaration may be an appropriate remedy for both jurisdictional errors and closely analogous defects such as unfairness or breaches of natural justice is shown by such Privy Council and House of Lords decisions as _De Verteuil_ v. _Knaggs_ (1918) A.C. 557, _Pyx Granite Co. Ltd._ v. _Ministry of Housing_ (1960) A.C. 260, and _Ridge_ v. _Baldwin_ (1964) A.C. 40. The statement apparently to the contrary at the end of the _Reynolds_ judgment at p. 40 is obsolete. And if a declaration could have been granted that a decision made under a statutory power is invalid the Court has power under the 1972 Act to set the decision aside. The Order for Costs In argument in the present case it was common ground that if the order for $150,000 costs is invalid the Court can set it aside. That is clearly so. The order was made in reliance on s. 11 of the Commissions of Inquiry Act 1908 which (notwithstanding an argument to the contrary by Mr Harrison) is in our opinion undoubtedly the only source of any authority for a Royal Commission or a Commission of Inquiry to award costs. If valid it is enforceable by virtue of s. 12 of that Act as a final judgment of the High Court in its civil jurisdiction. Plainly it is the exercise of a statutory power of decision. The jurisdiction of the New Zealand Courts to determine the validity of orders for costs by Commissions is well established: _Hughes_ v. _Hanna_ (1909) 29 N.Z.L.R. 16; _Whangarei Co-operative Bacon-Curing Co._ v. _Whangarei Meat-Supply Co._ (1912) 31 N.Z.L.R. 1223; _Pilkington_ v. _Plaits_ (1925) N.Z.L.R. 864. What was in dispute in the argument in this connection was principally whether the order is so linked with the challenged findings in the Report that if those findings are invalid for excess of jurisdiction or breach of natural justice the order will fall with them. There was a subsidiary argument about whether the order was in any event invalid because the amount may greatly exceed the maximum allowed by the long out-of-date but still apparently extant scale prescribed in 1903 (1904 Gazette 491). We propose to consider the main argument, however, and in doing so to confine attention to whether there is a sufficient link between the order and the main findings complained of in the Report, those in paragraph 377. At the beginning of his reasons for ordering costs the Commissioner expressed the opinion that the power should be exercised whenever the conduct of a party at the hearing has materially and unnecessarily extended the duration of the hearing. His following reasons include criticisms of the management of the airline for prolonging the hearing, and it was contended before us by Mr Baragwanath that they go no further. We are unable to accept that contention. In reciting the circumstances leading to the orders for costs the Commissioner expressly includes the chief executive's order for documents to be destroyed and says, "The cards were produced reluctantly, and at long intervals, and I have little doubt that there are one or two which still lie hidden in the pack". We think that such language would naturally be understood by a reasonable reader to refer back to the matters more fully developed in the section of the Report headed "The stance adopted by the airline before the Commission of Inquiry", a section culminating in paragraph 377 with its references to "a pre-determined plan of deception ... an attempt to conceal a series of disastrous administrative blunders ... an orchestrated litany of lies". The impression almost inevitably created is that, to adapt words used by Williams J. delivering the judgment of this Court in _Cock_ v. _Attorney-General_ (1909) 28 N.Z.L.R. 405, 421, the judgment for costs was in fact, though not in name, a punishment. The reasons given for the costs orders have definite echoes of paragraph 377 and the immediately preceding paragraphs. The airline was being required to pay costs, and not for delaying tactics simply. A significant part of the reasons was that in the view of the Commissioner its chief witnesses had been organized to conceal the truth. It is true that, on purely verbal grounds, refined distinctions can be drawn between the sections of the Report dealing with the airline's stance at the inquiry and with costs; but we have no doubt that their overall effect is that most readers would understand them as closely associated. It follows, we think, that if the findings in paragraph 377 are invalid for excess of jurisdiction or breach of natural justice they should be seen as playing a material part in the order for $150,000 costs and as requiring the Court to set aside that order. Irrespective of the order for costs, we think that there are strong arguments to support the view that there is jurisdiction to review the findings in challenged paragraphs on grounds relating to jurisdiction and natural justice. There is a good deal of support in the authorities for excluding or strictly limiting judicial review of Commission findings and Mr Baragwanath carefully put the arguments forward. But, as we say, there are reasons why the Court ought not to adopt the facile approach of saying that the function of the Commission was merely to inquire and report and that as the Commission's findings bind no-one they can be disregarded entirely as having no legal effect. Scope of Royal Commission As has been the practice in New Zealand when a Commission of Inquiry consists only of or is chaired by a High Court Judge, the Erebus Commission was a Royal Commission in that the warrant was expressed to be issued under the authority of the Letters Patent of 1917 constituting the office of Governor-General. One of the powers delegated by the Letters Patent to the Governor-General is to "constitute and appoint, in Our name and on Our behalf, all such ... Commissioners ... as may be lawfully constituted or appointed by Us". The warrant was also expressed to be issued under the authority of and subject to the provisions of the Commissions of Inquiry Act 1908, and s. 15 of that Act extends and applies not only to inquiries under statutory Commissions appointed by the Governor-General or Governor-General in Council but also to inquiries under the Letters Patent. This means inter alia that statutory-powers of summoning witnesses and requiring the production of documents apply, that a Judge of the High Court acting as Commissioner has the ordinary judicial immunity, and that interested persons have statutory rights to be heard under s. 4A, inserted by an amendment made in 1980 shortly before the inquiry now in question began. Section 2 of the 1908 Act empowers the Governor-General by Order-in-Council to appoint any person to be a Commission to inquire into and report upon any question arising out of or concerning a range of matters. The relevant one is "(e) Any disaster or accident (whether due to natural causes or otherwise) in which members of the public were killed or injured ..." In giving statutory power to appoint Commissions and listing permissible subjects the Act differs from the Evidence Acts considered in Australian cases. The Australian Acts presuppose the existence of Commissions appointed under prerogative or inherent executive powers and merely confer ancillary powers of compelling evidence and the like. Under Acts of that type the validity of the Commission depends on the common law and the division of powers in the Australian Constitution. Under the New Zealand Act a Commission can be given a statutory source for its basic authority even if it is a Royal Commission and has a prerogative source as well. The Erebus Commission was appointed to inquire into the causes and circumstances of the crash. Among the particular questions referred to it was: (g) Whether the crash of the aircraft or the death of the passengers and crew was caused or contributed to by any person (whether or not that person was on board the aircraft) by an act or omission in respect of any function in relation to the operation, maintenance, servicing, flying, navigation, manoeuvring, or air traffic control of the aircraft, being a function which that person had a duty to perform or which good aviation practice required that person to perform? All the terms of reference fall well within s. 2 (e). The Commission was not appointed to inquire into allegations of crime so we are not now called upon to go into the question whether a Royal Commission can be appointed for such a purpose, on which New Zealand and Australian authorities diverge (see _In re The Royal Commission on Licensing_ (1945) N.Z.L.R. 665, 679; and D.R. Mummery "Due Process and Inquisitions", 97 L.Q.R. 287). Nevertheless paragraph 377 of the Royal Commission Report contains findings of organized perjury. The judgment in the leading New Zealand case, _Cock_ v. _Attorney-General_, while denying that the prerogative can authorize a Commission with the main object of inquiring into alleged crimes, recognizes at p. 425 that a Commissioner may investigate an alleged crime if to do so would be "merely incidental to a legitimate inquiry and necessary for the purpose of that inquiry". We think that the test must be what is reasonably incidental to valid terms of reference. In relation to paragraph 377 the allegation of excess of jurisdiction turns accordingly on whether the findings are reasonably incidental to an inquiry into the causes and circumstances of the crash. It is difficult to find reasons why the Court should refuse to entertain that question. While Commissions of mere inquiry and report are largely free from judicial control, there is strong authority indicating that the Courts have at least a duty to see that they keep within their terms of reference. We agree with the opinion of Myers C.J. in the _Royal Commission on Licensing_ case at p. 680 that it is implicit in all the judgments in the Privy Council and the High Court in _Attorney-General for the Commonwealth of Australia_ v. _Colonial Sugar Refining Co. Ltd_ (1914) A.C. 237, 15 C.L.R. 182, that if it can be said in advance that proposed questions are clearly outside the scope of the inquiry they are irrelevant and cannot be permitted. In the _Royal Commission on Licensing_ case that very principle was applied in this Court, it being held that certain matters were not within the ambit of the Commission's inquiry. That decision was given on a case stated by the Royal Commission under ss. 10 and 13 of the 1908 Act, but the _Sugar Company_ case was an action for declaration and injunctions and the procedure was expressly approved in the judgment of their Lordships delivered by Viscount Haldane L.C. ((1914) A.C. at 249-50). Similarly in _McGuinness_ v. _Attorney-General_ (1940) 63 C.L.R. 73 the High Court, on an appeal from a conviction for refusing to answer a question touching the subject matter of an inquiry by a Commissioner, accepted without any apparent difficulty that the Court had authority to determine whether the question was relevant. We do not overlook that the cases just cited were concerned with the scope of questions that might be put to witnesses under compulsory powers given by statute. They were not directly concerned with the scope of findings in reports. But if the Court has jurisdiction to determine the true scope of a Commission's inquiry and require the Commission to keep within that scope there are obvious arguments that it should have a corresponding jurisdiction in the matter of findings. A vital part of the constitutional role of the Courts is to ensure that all public authorities, whether they derive their powers from statute or the prerogative, act within the limits of those powers. A different view was taken by Stephen J. sitting at first instance in chambers in _R._ v. _Collins_ (1976) 8 A.L.R. 691, but we note the opinion expressed in several Canadian cases that the Court will intervene where a Commissioner has inquired or seeks to inquire into matters outside his terms of reference: _Re Sedlmayr_ (1978) 82 D.L.R. (3d.) 161; _Re Anderson_ (1978) 82 D.L.R. (3d.) 706; _Landreville_ v. _The Queen_ (1973) 41 D.L.R. (3d.) 574; _Landreville_ v. _The Queen_ (No. 2) (1977) 75 D.L.R. (3d.) 380, 400-402. In _Re Royal Commission on Thomas Case_ (1980) 1 N.Z.L.R. 602 a Full Court (Molier, Holland and Thorp JJ.) held inter alia that the Court may prohibit a Commission from acting in excess of its jurisdiction and that the creation of a Commission pursuant to the Letters Patent does not exempt it from the supervisory role of the Court. However part of the Full Court's decision in that case is the subject of a pending appeal to this Court and other proceedings relating to the Thomas Commission have been moved into this Court. So we refrain from expressing any final view upon it. For the foregoing reasons we think that if the applicants make out their claim that the findings of the Erebus Commission in paragraph 377 are outside the commissioner's terms of reference, they could be granted a declaration to that effect at common law. To obtain a setting aside of the findings under s. 4 (2) of the Judicature Amendment Act 1977 they have to show in addition that the findings were made in the exercise of a statutory power of decision. We think this requirement should not present final difficulty if regard is had to the evident intent and spirit of the 1972 Act and particularly the amendments made by Parliament in 1977. Judicature Amendment Act 1972 Was the statutory power one of _decision_? The 1977 Amendment Act brought statutory investigations or inquiries into rights or liabilities within the definition of "statutory power". An inquiry into whether any person caused or contributed to the crash by an act or omission in respect of his duties is an inquiry into liabilities. But that is less important for present purposes than the fact that the Amendment Act also extended the concept of statutory powers of decision to those "affecting" the rights of any person. The purpose was manifestly to make the ambit of review under the Act at least as wide as at common law. This point is dealt with in _Daemar_ v. _Gilliand_ (1981) 1 N.Z.L.R. 61. We think it would be very difficult to justify an argument that findings likely to affect individuals in their personal civil rights or to expose them to prosecution under the criminal law are decision "affecting" their rights within the meaning of the Act. In the present case, for example, it was virtually certain that the findings of the Erebus Commission would be published by the Government. The effect on the reputation of persons found guilty of the misconduct described in the Report was likely to be devastating, at common law every citizen has a right not to be defamed without justification. Severe criticism by a public officer made after a public inquiry and inevitably accompanied by the widest publicity affects that right especially when the officer has judicial status and none the less because he has judicial immunity. The present case is in many ways unique and, if the findings in paragraph 377 were made without jurisdiction or contrary to natural justice, it affords a striking instance of how contrary to the public interest it would be if the Courts were not prepared to protect the right to reputation. The magnitude of the disaster, bringing tragedy to many homes in New Zealand and overseas, and the fact that the national airline was involved meant that the national attention was focused on the inquiry. There are imputations of collective bad faith which had started from a high place in the company and all this was likely to receive the widest publicity, further, the findings in paragraph 377 amounted to public and official disclosures of alleged criminal conduct and led to investigation by the police to determine whether charges should be laid. In the event it was announced shortly before the hearing of the present case that there would be no such charges, but clearly the individuals concerned were in fact exposed to the hazard of prosecution as a natural consequence of the Report. In interpreting the 1977 legislation we think that a narrow conception of rights and of what affects rights would not be in accord with the general purposes of the Act. A broad, realistic and somewhat flexible approach would enable the Act to work most effectively as an aid to achieving justice in the modern community. Natural Justice This Court has had to examine and apply the principles concerning natural justice and fairness quite often in recent years. In translating the ideals of natural justice and fairness into current operation in New Zealand we have been influenced as to general principles mainly by decisions of the Privy Council and the House of Lords but, of course, we have had New Zealand conditions and practicalities very much in mind. The result has been a pragmatic approach. Some overseas Courts have held that if all that occurs is inquiry and report and the report is not in law a condition precedent to some further step the rules of natural justice are automatically excluded. That was the premise, for instance, of the High Court of Australia in _Testro Bros. Pty. Ltd._ v. _Tait_ (1963) 109 C.L.R. 353. A contrary approach is to be found in the judgement of Schroeder J.A. representing the view of the majority of the Ontario Court of Appeal in _Re Ontario Crime Commission_ (1962) 133 C.C.C. 116, although that case depends partly on Ontario statute law. There is little attraction in the idea of automatic exclusion. Commissions of Inquiry have compulsory statutory powers of insisting on evidence and their findings can affect rights in the ways already outlined. It seems to us highly unlikely that the New Zealand Parliament intended them to be wholly free of the elementary obligation to give persons whom they have in mind condemning a fair opportunity for correcting or contradicting any relevant allegation. Some reinforcement for the view that they are under that obligation is to be found in some added considerations. Section 4A of the Commissions of Inquiry Act, enacted in 1980 in place of briefer provisions and in time for the Erebus inquiry, provides: "4A. Persons entitled to be heard--(1) Any person shall, if he is party to the inquiry or satisfies the Commission that he has an interest in the inquiry apart from any interest in common with the public, be entitled to appear and be heard at the inquiry. (2) Any person who satisfies the Commission that any evidence given before it may adversely affect his interests shall be given an opportunity during the inquiry to be heard in respect of the matter to which the evidence relates. (3) Every person entitled, or given an opportunity, to be heard under this section may appear in person or by his counsel or agent." The section may be seen as a recognition by Parliament that natural justice should apply. It does not purport to enact a complete code of procedure or to cover the whole field of natural justice, which would not be easy in a statute of this general kind. The statute specifically requires an opportunity to be heard to be given to any person who shows that evidence may adversely affect his interests. In the parallel situation of the statutory investigation which must be undertaken following any aircraft accident considerations of fairness are carefully spelled out in Regulation 15 (1) of the Civil Aviation (Accident Investigation) Regulations 1978. There it is provided that "where it appears to an Inspector that any degree of responsibility for an accident may be attributable to any person, that person or, if he is dead, his legal personal representatives, shall, if practicable, be given notice that blame may be attributed to him, and that he or they may make a statement or give evidence, and produce witnesses, and examine any witnesses from whose evidence it appears that he may be blameworthy". In the case of the earlier investigation by Mr. Chippindale into the Erebus disaster that very step was taken. In his judgment in the Court in _Re the Royal Commission on the State Services_ (1962) N.Z.L.R. 96, 117, Cleary J. while stressing the wide discretion of Commissions to regulate their own procedure said plainly that the one limitation is that parties cited and persons interested must be afforded a fair opportunity of presenting their representations, adducing their evidence, and meeting prejudicial matter. That judgment was given with reference to the old s. 4A, now replaced by the section already quoted. What Cleary J. said, particularly about the general absence of a right to be represented by counsel, must now be read subject to the new provisions. But his expression "prejudicial matter" was a general one. It ought not, we think, to be read down in some way so as to exclude suggestions of conspiracy which may have evolved in the mind of a Commission without being specifically raised in evidence or submissions. A suggestion of an organized conspiracy to perjure is different from the possibility commonly faced by individual witnesses that their evidence may be disbelieved. Grave findings of concerted misconduct in connection with the inquiry ought not to be made without being specifically raised at the inquiry. Once the thesis of such a conspiracy had emerged in the Commissioner's thinking as something upon which he might report, he would have had power, if that question were indeed reasonably incidental to his terms of reference, to reconvene the hearing if necessary so that the alleged conspirators could be fairly confronted with the allegation. See the speech of Lord Russell of Killowen in _Fairmount Investments Ltd._ v. _Secretary of State for the Environment_ (1976) 2 All E.R. 865, and the judgement of Lord Parker C.J. in _Sheldon_ v. _Bromfield Justices_ (1964) 2 Q.B. 573, 578. In fact in the present case but for a far less significant reason the Commissioner himself actually considered the possible need to reconvene the hearing after certain enquiries had been made on his instructions following the taking of evidence in public. The matter is mentioned in paragraph 358 of the Report. _Landreville_ v. _The Queen_ (No. 2) (1977) 75 D.L.R. (3d.) 380, 402-405, was decided in the end on just such a ground. It was held that a Commissioner, who happened to be a distinguished Judge, had failed to put to the person whose conduct was expressly subjected to investigation by the terms of reference of the Commission a very serious allegation upon which a finding was made in the report; and that the Commission should have been reconvened for that purpose. There the relevant rule of natural justice was fully embodied in a statutory provision. We think that the position is the same under the New Zealand Commissions of Inquiry Act supplemented by the common law. All these considerations suggest that the Commission was bound by the broad requirements of natural justice. These included a reasonable opportunity of meeting the unformulated allegation of organized deception and concealment that was apparently passing through the Commission's mind. Some of the reasons why experience has shown the importance of this sort of opportunity were well put by Megarry J. in _John_ v. _Rees_ (1970) 1 Ch. 345, 402.: "It may be that there are some who would decry the importance which the courts attach to the observance of the rules of natural justice. 'When something is obvious,' they may say, 'why force everybody to go through the tiresome waste of time involved in framing charges and giving an opportunity to be heard? The result is obvious from the start.' Those who take this view do not, I think, do themselves justice. As everybody who has anything to do with the law well knows, the path of the law is strewn with examples of open and shut cases which, somehow, were not; of unanswerable charges which, in the event, were completely answered; of inexplicable conduct which was fully explained; of fixed and unalterable determinations that, by discussion, suffered a change. Nor are those with any knowledge of human nature who pause to think for a moment likely to underestimate the feelings of resentment of those who find that a decision against them has been made without their being afforded any opportunity to influence the course of events." In this particular case something more should be said. The applicants contend that this is not simply a case where the conspiracy suggestion could not have been rebutted. They plead in their statement of claim that the Commissioner's findings to that effect are not based on evidence of probative value. Elsewhere in the present judgment we deal with aspects of these arguments. Here, dealing with principles, we add that fairness is not necessarily confined to procedural matters. It can have wider range. Remedies in this field are discretionary and the law not inflexible. If a party seeks to show not only that he did not have an adequate hearing but also that the evidence on which he was condemned was insubstantial, the Court is not compelled to shut its eyes to the state of the evidence in deciding whether, looking at the whole case in perspective, he has been treated fairly. Factual Background In a written synopsis of argument presented before this Court by counsel for Air New Zealand it was said that background matters had to be understood as they were entirely relevant to the complaints made by the applicants in the present proceedings. But that "the Applicants do not propose to canvass any factual matters which fall outside the range of their specified allegations". In regard to that last matter we emphasize again that this case (as counsel well realized) cannot be used to attack the Royal Commission findings as to the cause of the crash. On behalf of the applicants it was made clear nonetheless that their acceptance of the jurisdictional bar to such a challenge in the Courts did not mean and should not be used to draw any inference that they accepted the causation findings themselves (at least in the unqualified form in which they are set down in the Report). It is simply that they do all readily accept as they must that in no sense can these proceedings become an appeal against those findings. It is right to add that throughout the hearing in this Court that attitude has very properly been reflected in the submissions we heard. Thus the conclusions as to the cause of the crash must and do stand. Late in 1976 Air New Zealand decided to commence a series of non-scheduled sightseeing journeys from New Zealand to the Ross Dependency region and return to this country without a touch-down at any intermediate point. They began with two flights in February 1977. There were four further journeys in October and November 1977, four in November 1978, and three more in November 1979--on 7th, 14th and 21st. The accident flight was to be the fourteenth of the series. In 1977 the designated route was one which used Cape Hallett on the north-eastern point of Victoria Land as the first southern waypoint on the continent itself en route further south either to a point adjacent to the Williams ice landing field (near Scott and McMurdo bases) or alternatively the south magnetic pole. One or other became the southernmost waypoint, the magnetic pole destination being used at the discretion of the pilot if weather conditions made the McMurdo area unsuitable for sightseeing. Scott and McMurdo bases are located close together at the south-western tip of Ross Island which forms the eastern coast of McMurdo Sound. On the island there are four volcanic mountains including Mt. Erebus, the highest, at 12,450 feet. The Sound itself, which is about 40 miles long by 32 miles wide at the narrowest point, lies between mainland Antarctica and Ross Island and for most of the year it is covered with flat sea ice. The first two flights in February 1977 took place with the necessary approval of the Civil Aviation Division of the Ministry of Transport and after clearance with the United States naval authorities who control the air space in the vicinity of McMurdo Station. Those flights followed a computer-controlled flight track to Cape Hallett thence directly over Ross Island and Mt. Erebus at the stipulated minimum height of 16,000 feet to the McMurdo waypoint. The co-ordinates of that waypoint had been written correctly into the flight plan as 77° 53' south latitude and 166° 48' east longitude. Three of the pilots who flew to the Antarctic in November 1977 were available to give evidence and, like the two earlier pilots, they agreed that at that time the flight plan followed a track from Cape Hallett to the McMurdo area which passed virtually overhead Mt. Erebus. However then and on subsequent occasions the sightseeing aircraft to the McMurdo area arrived in the general vicinity of Cape Hallett to find clear air further on and took the opportunity of visual meteorological conditions to veer laterally from the direct computer flight track from Cape Hallett by tracking to the west along the coast of Victoria Land and eventually down McMurdo Sound over the flat sea ice. Ross Island was thus left to the east while near the head of the Sound the aircraft would turn left in order to fly over Scott and McMurdo bases and in the vicinity of Ross Island so that a view would be obtained of Mt. Erebus and the other three mountains there. When the decision was made to operate the series of flights to take place at the end of 1977 a change was made with the approval of the Civil Aviation Division to permit flights below 16,000 feet down to 6,000 feet in a specified sector south of Ross Island and subject to such criteria as a cloud base no lower than 7,000 feet, clear visibility for at least 20 miles and descent under ground radar guidance. It has been mentioned that similar criteria applied, officially at least, until the time of the fatal crash. But the written directions were interpreted by some pilots as leaving them with a degree of discretion to go lower in ideal weather conditions. Then in September 1978 steps were taken to print a flight plan for each Antarctic journey from a record stored in the Air New Zealand ground based planning computer. And it is at this stage that the longitude co-ordinate for the southernmost waypoint was fed into the ground computer as 164° 48' E. The Flight Track The navigation system used by DC10 aircraft is a computerised device known as the area inertial navigation system (AINS). It enables the aircraft to be flown from one position to another with great accuracy. Prior to departure of a flight the AINS aboard the aircraft is programmed by inserting into its computers the co-ordinates of the departure and destination points (in degrees of latitude and longitude) together with those of specified waypoints en route. In the case of the Antarctic flights (which were engaged on what may be described as a return trip without touch-down) the southernmost waypoint, like each of the intermediate positions, was really a reference point to which the pilot knew the aircraft would be committed if it were left to follow the computer-directed flight track. And as mentioned the southern point for the preferred route to the McMurdo area was a ground installation at Williams Field. During 1977 the co-ordinates for each waypoint which comprised the Antarctic routes had not been stored on magnetic tape for automatic retrieval and insertion into the navigation computer units of the aircraft. Instead the flight plan was dealt with manually and upon issue to the aircrew at the time of departure was manually typed by the pilot concerned into the aircraft computer units. When the Air New Zealand ground based computer was used in 1978 to produce computerised Antarctic flight plans they followed the same format as those that had been produced earlier. But before the ground computer could be programmed it had been necessary for an officer of the navigation section to prepare a written worksheet containing all the waypoints and their respective latitude and longitude co-ordinates which then were transcribed from the worksheet. And by reference to the original flight plan used in February 1977 this was done by Mr Hewitt, one of the four members of the navigation section at airline headquarters. He said in evidence before the Royal Commission that when he went on to take from his written worksheet the longitude co-ordinates of the McMurdo waypoint he mistakenly transcribed the correct figures of 166° 48' as 164° 48' by inadvertently typing the figure "4" twice. This had the effect of moving the McMurdo waypoint 25 nautical miles to the west and once in the aircraft's system the navigation track which then it would follow from Cape Hallett when under automatic control would be over the[1] Sound rather than directly to Williams Field. At this point it should be mentioned that the print-out of a flight plan shows not merely the co-ordinate waypoints but also a finely calculated statement of the direction and distance between them. This last information is obtained independently from what is called the NV90 programme of the computer which is able automatically to calculate the rhumb line track and distance between each of the respective waypoints once the co-ordinates have been fed into it. This information forms the basis for the data required to produce the computerised flight plan. So that finally when a print-out of the plan is obtained it will disclose not merely the geographical co-ordinates for each waypoint but the true track direction and the distance in nautical miles from one to the next. That last information is needed prior to a flight departure in order to calculate tonnages of fuel during the prospective journey and accordingly as a flight proceeds it enables the quantity of fuel already consumed to be checked against the anticipated consumption in the flight plan print-out. Thus the precise track and distance is used for purposes of fuel calculations and has importance as a check in navigation. All this information is disclosed on page 96 of the Royal Commission Report where the print-out is shown for the flight plan with the co-ordinates for McMurdo showing the longitude as 164° 48' east. In the next column the track direction is given as 188.9° (grid) and the distance between Cape Hallett and McMurdo as 337 miles. On the facing page 97 there is a print-out of the flight plan actually used on the fatal flight which shows the correction made to the longitude, 166° 58' east. It will shortly be mentioned that when that correction was made the navigation section say it was thought to involve a minor movement of only 2.1 miles or 10 minutes of longitude. Despite the very small change that this could make to the track and distance between the two points a re-calculation was made and entered into the computer programme as 188.5° (grid) and the distance 336 miles. Compared with the other figures the difference seems minimal but it was still thought necessary to assess it and it was done. The Western Waypoint The circumstances surrounding the use of the 164° 48' E figures were in issue before the Royal Commission. It was suggested against the airline they had not been introduced accidentally: that the movement of the position 25 miles to the west had been deliberate. If that were so it would seem that a re-calculation of track and distance would have been needed and made both for the fuel plan and also as a check for purposes of navigation. However, no re-calculation of track and distance was made and entered with the 164° 48' co-ordinate. The figures which actually appear for track and distance to that point remain precisely the track and distance figures which were shown in the flight plan to the 166° 48' point for the first flight in February 1977. For purposes of comparison a calculation to the "false" waypoint was prepared and put before the Royal Commission. It showed that a direct track from Cape Hallett to that point is actually 191° and the distance 343 miles. The point is referred to in paragraph 230 of the Report within a section headed "The creation of the false McMurdo waypoint and how it came to be changed without the knowledge of Captain Collins". In paragraph 229 it is said that submissions had been put to the Commissioner that "the shifting of the McMurdo waypoint was done deliberately so as to conform" with a track used by military aircraft proceeding to Williams Field. Then in paragraph 230 there is a summary of contrary arguments advanced by members of the navigation section to support their claim of accident. They include-- "(c) It was pointed out that if the McMurdo waypoint had been intentionally moved 25 miles to the west, then the flight plan would have a corresponding change to the track and distance information which it previously contained. Instead of a true heading from Cape Hallett to the NDB of 188.9° and a distance of 337 nautical miles, there would have been required, in respect of the changed McMurdo waypoint, a true heading of 191° and 343 nautical miles. Similar alterations would have had to be made in respect of a return journey to the true north." That is the matter already outlined. Concerning it the Commissioner said in paragraph 234 that there was "considerable validity in this point" although then he added: "... the Navigation Section may have thought it not necessary to alter the track and distance criteria from Cape Hallett to McMurdo for the reason that the pilots were accustomed to flying on Heading Select down this sector and not by reference to the fixed heading programmed into the AINS." There is a further argument of the navigation section which is summarized in paragraph 230 (e)-- "It was submitted that an alteration to the McMurdo waypoint to facilitate better sightseeing was not valid because flight captains had a discretion to deviate horizontally from the flight plan track." The Commissioner accepted that point as "a valid objection" in answer to the suggestion that the move had been deliberate (paragraph 236). However when he came in paragraph 255 (a) to express his final conclusion upon this general question he initially said this-- "The first question is whether the programming of the McMurdo waypoint into the 'false' position before the commencement of the 1978 flights was the result of accident or design. On balance, it seems likely that this transposition of the McMurdo waypoint was deliberate." There is reference at that point to a track and distance diagram indicating a track down McMurdo Sound, and the sub-paragraph then continues-- "So as I say, I think it likely that the change of the McMurdo destination point was intended and was designed by the Navigation Section to give aircraft a nav track for the final leg of the journey which would keep the aircraft well clear of high ground." Then the final portion of paragraph 255 (a) leaves the matter in the following half-way situation-- "However, I propose to make no positive finding on this point. I must pay regard to the circumstance strongly urged upon me by counsel for the airline in their closing submissions, namely, that if the alteration was intentional then it was not accompanied by the normal realignment of the aircraft's heading so as to join up with the new waypoint. As I say, I think this latter omission is capable of explanation but it is a material fact in favour of the Navigation Section which I cannot disregard, and it is the single reason why I refrain from making a positive finding that the alteration of the waypoint was intentional." It may be that in speaking of a single reason in the last sentence of the extract the Commissioner put aside his earlier unqualified conclusion that the matter set out in paragraph 230 (e) was also "a valid objection" to the suggestion that the waypoint had been moved deliberately. In any event the eventual and significant finding concerning the matter is contained in the following sub-paragraph 255 (b): "I believe, however, that the error made by Mr Hewitt was ascertained long before Captain Simpson reported the cross-track distance of 27 miles between the TACAN and the McMurdo waypoint, and I am satisfied that because of the operational utility and logic of the altered waypoint it was thereafter maintained by the Navigation Section as an approved position." At this point it is necessary to explain the reference in that sub-paragraph to Captain Simpson; and then, if it be assumed that "the altered waypoint ... was thereafter maintained ... as an approved position", it is necessary to understand the reasons given by the Commissioner for the change back to Williams Field. If the altered waypoint had been adopted as a better position why was it then thought that it had to be discarded? Correction of co-ordinates It was not until 14th November 1979 that any question arose about the McMurdo waypoint. On that day Captain Simpson had taken the second November 1979 sightseeing flight to the Antarctic and something persuaded him to raise the matter of the southern waypoint with Captain Johnson, the Flight Manager Line Operations. There is a difference of opinion as to precisely what was said by Captain Simpson to Captain Johnson but according to the evidence of those in the navigation section they thought that when they checked up-to-date records of the co-ordinates at McMurdo Station against the original NV90 flight plan what had been brought forward for notice was the small difference of 10 minutes of longitude to which reference has been made. They said this represented the recent relocation of the tactical air navigation system (the TACAN) at Williams Field. Accordingly Mr Brown of the navigation section wrote into his worksheet a corrected position of 77° 52.7' S and 166° 58' E and entered those figures into the system on 16th November. But the amendment was not made in the live flight planning system until the early hours of 28th November. According to the members of the navigation section all this was done without knowledge that the effect of introducing the amended figures would be to override "164° 48'" and so alter the co-ordinate by 2° 10' rather than 10'. The Commissioner rejected the explanations he had heard to the effect that Captain Simpson's information seemed to point to quite a minor movement to the up-dated position of the TACAN. He stated that there appeared to have been clear advice by Captain Simpson that the "false" waypoint was 27 miles west of it. In addition he rejected the possible explanation that the advice had been misinterpreted by Captain Johnson to whom it had been given, and he adopted instead what in paragraph 245 he described as "the second explanation": "(b) The second explanation is that both Captain Johnston and the Navigation Section knew quite well that the McMurdo waypoint lay 27 miles to the west of the TACAN and that since his track had not officially been approved by the Civil Aviation Division it should therefore be realigned with the TACAN and then someone forgot to ensure that Captain Collins was told of the change. Such an interpretation means that the evidence as to the alleged belief of a displacement of only 2.1 miles is untrue." Then in paragraph 255 (d) he said this: "If, as I have held, the Navigation Section knew the actual position of the McMurdo waypoint as being 27 miles to the west of the TACAN, then why did they not submit to Captain Johnson, or to flight Operations Division, that the waypoint should remain where it was? One view is that the Flight Operations Division expected, in terms of Captain Johnson's letter to the Director of Civil Aviation dated 17 October 1979, that the next edition of the Ross Sea chart NZ-RNC4 would contain the official Air New Zealand flight path to McMurdo, and that the safest course would be to put the destination point back to the approximate location at which Civil Aviation Division had thought it had always been." That last suggestion was not put to any of the navigation witnesses at the Inquiry. It implies that although those in the navigation section believed the airline had been using a computer track to the west of Ross Island for the past year because it was the better route they nevertheless suddenly became uneasy lest knowledge of the matter would now reach the Civil Aviation Division which had not given its official blessing to the change. The idea apparently is that because the airline might receive an official rebuke the officers in the section made their own independent decision that the route must once again be directed back over Mt. Erebus. There was no evidence at all before the Royal Commission that the approval of the Civil Aviation Division was needed for a change from the direct Cape Hallett/McMurdo route. An affidavit in support of the present application for review indicates that if the matter had been raised at the Inquiry members of the navigation section would have wished to present evidence from the Civil Aviation Division that "a change of route from the direct route to the McMurdo Sound route would not have required CAD approval and therefore could have been lawfully accomplished by the airline without reference to CAD". That situation may have been anticipated by the Commissioner himself for by reference to the false waypoint and the earlier consequential movement of the computer flight track down McMurdo Sound to the west he said that although approval of the route by the Civil Aviation Division should have been obtained it "would have been automatic" (paragraph 150). In paragraph 255 (f) of the Report the explanation from all four members of the navigation section is described in the following way: "In my opinion this explanation that the change in the waypoint was thought to be minimal in terms of distance is a concocted story designed to explain away the fundamental mistake, made by someone, in failing to ensure that Captain Collins was notified that his aircraft was now programmed to fly on a collision course with Mt. Erebus." That finding is one of those directly challenged in the present proceedings. Advice of the Change A different matter was considered by the Commissioner in relation to the change made in November 1979 to move the waypoint back to the TACAN at Williams Field. As usual a signal was sent to the United States base at McMurdo with advice that the aircraft was to fly to the Antarctic on 28th November and the flight plan for the journey. And in the list of waypoints appears the word "McMurdo" in lieu of the geographical co-ordinates which had appeared in the equivalent signal for the flight three weeks earlier. The message had been prepared by Mr Brown, one of the four officers in the navigation section. The use of the word "McMurdo" was the subject of an idea put by the Commissioner to Mr Hewitt, who was the second of the witnesses from the navigation section. The Commissioner asked: "I know you have explained to me how that happened but someone may suggest to me before the enquiry is over that the object was to thats (sic) not to reveal there had been this long standing error in the co-ordinates and that is why the word McMurdo was relayed to them. I take you would not agree with that" Mr Hewitt said: "Certainly not sir." The suggestion had not been raised earlier at the Inquiry and it was not mentioned by anybody subsequently. In particular it was not put to Mr Brown himself when the latter was called to give evidence three months later. However the Commissioner expressed his view upon the matter in the following way. In paragraph 255 (e) he said this-- "In my opinion, the introduction of the word 'McMurdo' into the Air Traffic Control flight plan for the fatal flight was deliberately designed to conceal from the United States authorities that the flight path had been changed, and probably because it was known that the United States Air Traffic Control would lodge an objection to the new flight path." It will be observed that the last few words are qualified by "probably". It appears that the Commissioner was told during a visit to Antarctica that the United States authorities would not have approved a flight path over Ross Island. But there was no evidence that Air New Zealand had ever received an intimation from the United States authorities to that effect or that the navigation section had reason to think they would so object. The qualification seems to reflect that position. In the result, when the findings in the two sub-paragraphs 255 (e) and (f) are put together they reveal the theory that at one at the same time the navigation section felt obliged to conceal from officials in Wellington the use of a flight track down McMurdo Sound that was regarded favourably by officials at McMurdo Station and from officials at McMurdo Station a flight track over Ross Island that was regarded favourably by officials in Wellington. Whiteout In relation to the cover-up allegations that have been made against the executive officers some reference should be made to their knowledge or otherwise of the freak meteorological condition known as "the whiteout phenomenon". Did they know or suspect that such a condition must have been an explanation for what happened and yet still be determined as the Commissioner found, to promote pilot error as the cause of the crash? It is something that can be mentioned quite briefly. The Royal Commission Report has made it clear the phenomenon can result in a loss of horizon definition and depth perception and is a great hazard for those who fly in arctic or antarctic conditions. The Commissioner found that at the critical time "air crew had been deceived into believing that the rising white terrain ahead was in fact quite flat and that it extended on for many miles under the solid overcast". This danger is something well known to those who fly regularly in those areas. Unfortunately it is not so well known by others, and as the Commissioner stated in paragraph 165 it was not understood by any of those involved in this case. He said: "So far as I understand the evidence, I do not believe that either the airline or Civil Aviation Division ever understood the term 'whiteout' to mean anything else than a snowstorm. I do not believe that they were ever aware, until they read the chief inspector's report, of the type of 'whiteout' which occurs in clear air, in calm conditions, and which creates this visual illusion which I have previously described and which is, without doubt, the most dangerous of all polar weather phenomena." It would seem that if those at airline headquarters were unaware of the deceptive dangers of the whiteout phenomenon they could not have deliberately ignored it as a factor that should be taken into account in favour of the aircrew. Instructions of the Chief Executive In paragraph 41 and following paragraphs there is reference to "what happened at the airline headquarters at Auckland when the occurrence of the disaster became first suspected and then known". It is explained that the navigation section became aware of the fact that when the McMurdo waypoint co-ordinates were corrected in November 1979 the movement was not one of 2.1 miles within the vicinity of Williams Field but a distance of 27 miles from longitude 164° 48' E; and that "by 30 November the occurrence of this mistake over the co-ordinates was known not only to the Flight Operations Division but also to the management of the airline. In particular it had been reported to the Chief Executive of Air New Zealand, Mr. M.R. Davis". At that point there follows the serious allegation in paragraph 45 already cited-- "The reaction of the chief executive was immediate. He determined that no word of this incredible blunder was to become publicly known." On the face of it the unqualified idea expressed in that sentence is that Mr. Davis had decided to suppress from everybody outside the airline all information about the changed flight track. But if that meaning were intended it has been greatly modified in paragraph 48. There it is said-- "It was inevitable that these facts would become known. Perhaps the chief executive had only decided to prevent adverse publicity in the meantime, knowing that the mistake over the co-ordinates must in the end be discovered." Of course if the decision were merely "to prevent adverse publicity in the meantime" then such an attitude could not in any way be consistent with an attempt "orchestrated" by Mr. Davis to hid from official scrutiny what finally was held by the Commissioner in paragraph 393 to be "the single dominant and effective cause of the disaster". Despite that, paragraph 48 goes on to say this: "This silence over the changing of the co-ordinates and the failure to tell the air crew was a strategy which succeeded to a very considerable degree. The chief inspector discovered these facts after he had returned from Antarctica on or about 11 December 1979. In his report, which was published in June 1980, the chief inspector referred to what he termed the 'error' in the McMurdo destination point, and the fact that it had been corrected a matter of hours before the flight left Auckland." It is difficult to understand why the Commissioner considered "this silence over the changing of the co-ordinates and the failure to tell the air crew" had been "a strategy which succeeded to a very considerable degree". The information had been given to the chief inspector immediately on his return from Antarctica. That much is acknowledged in the two sentences that follow. It becomes apparent, however, that this was criticized not because the information had been kept away from those to whom it most certainly had to be given, those charged with the important responsibility of inquiring into the causes of the disaster. Mr. Davis was criticized for nothing more than his failure to release the material to the outside world. That is made plain by a subsequent statement towards the end of the Report which leads on to the very severe pronouncement in paragraph 377 that the Commissioner had been obliged to listen to "a predetermined plan of deception ... an orchestrated litany of lies". The relevant passage is in paragraph 374: "The fact that the navigation course of the aircraft had been altered in the computer had been disclosed by the chief inspector in his report dated 31 May 1980, 6 months after the disaster. But it was not until the Commission of Inquiry began sitting that the airline publicly admitted that this had occurred." The effect of the absence of general publicity that the information was given rather than its ready provision by the airline to Mr. Chippindale on the day after his return from the crash site is described in the remaining portion of paragraph 48 which continues in the following way: "Then the chief inspector went on to say in his report (paragraph 2.5): 'The error had been discovered two flights earlier but neither crew of the previous flight or that of the accident flight were advised of the error by the flight despatcher prior to their departure.' The chief inspector did not make it clear, however, that the computer flight path of TE 901 had been altered before the flight, and that the alteration had not been notified to the air crew. Had that fact been disclosed in the chief inspector's report then the publicity attending the report would undoubtedly have been differently aligned ... the news blackout imposed by the chief executive was very successful. It was not until the hearings of this Commission that the real magnitude of the mistake by Flight Operations was publicly revealed." Concerning that last part of paragraph 48 it seems that the Commissioner's remark immediately following the extract from paragraph 2.5 is inaccurate. It appears to suggest either that the chief inspector was unaware of the fact that the alteration to the co-ordinates "had not been notified to the air crew"; or that if he had been made aware of that fact then he had failed to bring it to public attention in his report as the next sentence suggests. But Mr. Chippindale was both aware of all this and he said so. In paragraph 1.17.1 he explicitly stated: "This error was not corrected in the computer until the day before the flight. Although it was intended that it be drawn to the attention of the previous crew, immediately prior to their departure this was not done, _nor was it mentioned during the pre-flight dispatch planning for the crew of the accident flight_". (Emphasis added.) The "pre-flight dispatch planning" mentioned in those last words was the occasion of final briefing of the aircrew immediately before the aircraft left Auckland on the morning of 28th November 1981. A different comment upon paragraph 48 is central in this part of the case. It is very hard to understand why the chief executive officer of this airline should have had any duty to pass on for debate and public prejudgment the same material that in accord with his responsibility had been properly and immediately placed before the appointed official required and well equipped to assess it. "Irrelevant" Documents At the beginning of this judgment a different aspect of paragraph 45 is explained by contrast with the following paragraph 46 which correctly summarizes instructions given by Mr Davis for the disposal of surplus copies of documents lest they be leaked to the news media. In paragraph 46 it is explained by the Commissioner that "his instructions were that _only copies of existing documents were to be destroyed_. He said that he did not want any surplus document to remain at large in case its contents were released to the news media by some employee of the airline. The chief executive insisted that his instructions were that all documents of relevance were to be retained on the single file" (emphasis added). There was no evidence before the Royal Commission to any contrary effect. But in the preceding paragraph a different impression is given. The relevant part of paragraph 45 reads-- "He directed that all documents relating to Antarctic flights, and to this flight in particular, were to be collected and impounded. They were all to be put on one single file which would remain in strict custody. Of these documents"-- that is, _all_ documents relating to the Antarctic flights--the sentence continues: "all those which were not directly relevant were to be destroyed. They were to be put forthwith through the company's shredder." Then in paragraph 54 the actual instruction is taken into a further dimension where it is described as "this direction on the part of the chief executive for the destruction of 'irrelevant documents'". And one serious complaint made by the applicants about the Royal Commission Report is that what could be an understandable direction for the _retention_ of one copy on a master file _of all relevant documents_ has become an unacceptable instruction that _irrelevant documents_ (related to the Antarctic flights nonetheless) _should be destroyed_. We think the complaint is justified. At the same early stage of the Report the Commissioner gave his attention to the question as to what if anything was done about the suppression of documentary evidence. He said in paragraph 52: "As will be explained later, there was at least one group of documents which certainly were in the possession of the airline as from the day following the disaster, and which have never been seen since. I am referring here to the flight briefing documents of First Officer Cassin.... (He) had left his briefing documents at home. They were recovered from his home on the day after the disaster by an employee of the airline. As I say, they have never been seen since." In the following paragraph 53 he observed--"If the explanation of the chief executive is to be accepted, then in the opinion of someone the briefing documents of First Officer Cassin, the co-pilot, were thought to be irrelevant to the disaster"; and in paragraph 54--"it follows that this direction on the part of the chief executive for the destruction of 'irrelevant documents' was one of the most remarkable executive decisions ever to have been made in the corporation affairs of a large New Zealand company". Those remarks require some brief comment. It must be explained that the "employee of the airline" mentioned at the end of paragraph 52 was Captain Crosbie. It is true that he was "an employee of the airline" but he did not go to the home of First Officer Cassin in that capacity. He had been asked by the Airline Pilots Association, the group which throughout the inquiry had very properly been concerned to protect the interests of the two deceased pilots, to act on their behalf for the purpose of bringing immediate aid and comfort to the two widows. His evidence was to the effect that he had gone to each of the homes for that purpose; that sometime later a member of Mrs Cassin's family had invited him to take away a box containing such items as flight manuals; and he said he had done no more than that. He flatly denied taking any flight documents. But even if he had, the alleged conspiracy has always been limited in the Royal Commission Report to the executive pilots and other officers in the management area. It has never been suggested that it had extended as well to the airline pilots. As may be expected, throughout both investigations they have done their conscientious best to protect the valued reputations of their deceased colleagues. There was documentary evidence before the Inquiry to the effect that on 30th November 1979 an in-house committee of Air New Zealand met on the instruction of Mr Davis for the purpose of deciding how to collect together all available information relevant to the accident. It seems that it began its practical work on Monday 3rd December. In that regard and as an example of the way in which the applicants say the cover-up allegation could have been answered by those affected they placed material before this Court which would suggest that the formation of such a committee is a conventional step taken by an airline when confronted with any serious disaster, that it was required by this company's Accident Investigation Procedures Manual, and that this committee was appointed accordingly. If it had been before the Inquiry it would have supported the view that Mr Davis had decided the chairman should not be associated with the flight operations side of Air New Zealand and for that reason he appointed Mr Watson who had charge of certain related companies. There is also an affidavit sworn by Captain Priest who was appointed by the Airline Pilots Association to sit as its representative on the committee. Taken at its face value it is to the effect that he took part in the committee's work from the meeting on 3rd December. In the affidavit he has explained: "My position on that Committee was an ALPA watchdog--there were two other independent members"; that as the inquiry progressed "it became apparent that the committee was amassing a large amount of papers"; and that Mr Watson then announced that he had been directed by the chief executive to get all the information onto one file and any surplus disposed of to avoid information getting into the wrong hands. The affidavit indicates that it was then agreed by the committee itself that this should be done on the basis that the master file was to be available to the committee members at any time and it appears that Captain Priest joined in that decision. It is not for us to decide what would have been the effect or significance of all this material if it had been placed before the Royal Commission but since the conspiracy to deceive theory that is developed in the Royal Commission Report apparently stems from the instruction given by Mr Davis clearly the officers so gravely affected were entitled to be warned in advance and so be given the opportunity to have such information fairly and properly considered. Search at Mt. Erebus The issue of documentary evidence is given extended attention in a section of the Report headed, "Post-accident conduct of Air New Zealand" which is exclusively concerned with suggestions of possible items that might have been withheld from the Inquiry. The discussion is introduced at paragraph 342 by a statement that "This instruction by the chief executive for the collection of all Antarctica documents had some unfortunate repercussions". The observation is then developed by reference in particular to the work of Captain Gemmell, the technical flight manager for Air New Zealand, while assisting Mr Chippindale at the crash site. Captain Gemmell had received instructions in the early hours of the morning of 29th November 1979 to travel to McMurdo in order to assist Mr Chippindale's investigation into the cause of the accident at the scene. However, by reason of weather conditions it was not possible for him to be taken by helicopter to the ice slope until 3 p.m. on 2nd December. Then, clad in protective clothing and roped to mountaineers, he assisted in a search for the in-flight recording equipment (consisting of the cockpit voice recorder and the "black box") and the recovery of any other equipment or documents which might indicate how the accident had happened. Three days earlier, at about 8.30 a.m. on the very morning after the accident, three mountaineer staff members at Scott Base had managed to get there in order to search for survivors. And Mr Woodford, who was one of them, has described the scene in a letter received by the Royal Commissioner during the public hearings. The letter, which is amplified in a affidavit put before this Court, is set out later in this judgment. Mr Woodford explained that when he got to the scene he found a black flight bag with Captain Collins' name printed on it. It was lying open on the snow and it was empty. Already material in the form of books and papers that had not been destroyed when the aircraft disintegrated on impact had been blown by winds over the ice-slope or into crevasses or covered by drifting snow. He pointed out that although the cockpit voice recorder had been located quite quickly when he was back at the crash site with the party from New Zealand on 2nd December the "black box" could not be found until later that evening after it had been decided to begin digging systematically for it. It was found buried under snow at a depth, he said, of 20 to 30 cms. But although the bag was empty it was suggested at the hearing that while at McMurdo Captain Gemmell might have "collected a quantity of documents from the crash site and brought them back to Auckland"; that only three of the flight documents carried on the aircraft had been produced to the Royal Commission; that it was "curious" to find that each favoured the case "which the airline was now attempting to advance"; and all this against counsel's theory that before Captain Gemmell had left Auckland on 29th November he was aware of possible problems associated with the amendment to the destination point co-ordinates. Captain Gemmell flatly denied having that knowledge while in the Antarctic; and he rejected totally any suggestion that he had recovered anything from the site which had not been passed across in terms of Mr Chippindale's instructions. In that regard he answered two propositions put to him by the Commissioner (at page 1834) in the following way: "Well the suggestion may be made to me in due course that because of the discovery that Capt Collins did not know of the alteration in the nav track consequently someone in the co. would have been instructed to locate whatever documents there were on the crash site and elsewhere that might throw light on that question. You say that no such instruction was given to you.... Certainly not. But it would have been a reasonable instruction would it not.... No it would not have." Intimidation of a Witness At this point it is necessary to mention a different suggestion which was also rejected by Captain Gemmell. It was put to him during cross-examination that he had carried back from McMurdo a blue plastic envelope containing personal property recovered from the accident site. In evidence given later by First Officer Rhodes the envelope was supposed to have been entrusted to Captain Gemmell by Mr Chippindale for delivery in New Zealand since Captain Gemmell was about to depart from the base several days before the others. First Officer Rhodes had himself been in Antarctica as a member of Mr Chippindale's investigation team, representing there the Airline Pilots Association. He appeared as a witness before the Royal Commission on two occasions. During his first appearance he was called by the Association. He did not refer then to a blue envelope; but because it was thought that the material may have been mentioned by him to the Association's counsel he was recalled to give evidence, this time by counsel for the airline. Before turning to the evidence given by First Officer Rhodes during his second appearance it is worthwhile making a preliminary comment. No complaint has ever been made by Mr Chippindale about a missing blue envelope or papers within it. If Captain Gemmell had been entrusted with such a mission which he had failed to discharge Mr Chippindale would seem to be the first person who would want to know why. He himself gave evidence before the Royal Commission for a period of ten days and during all that time he was never asked about this matter. Nor was he recalled to deal with it after it had been raised with Captain Gemmell or after First Officer Rhodes gave his further evidence. That fact alone might be thought sufficient to dispose of the matter. And in the end the Commissioner himself decided that neither this nor other evidence could justify a finding against Captain Gemmell that he "recovered documents from Antarctica which were relevant to the fatal flight, and which he did not account for to the proper authorities". It is necessary to describe all this because the second appearance of First Officer Rhodes resulted in a finding in paragraph 348 of the Royal Commission Report which reflects seriously upon the conduct of another executive officer of the airline, Captain Eden. The paragraph is another of those challenged in the present proceedings. It seems that First Officer Rhodes agreed to give evidence on the second occasion in order to remove any false impression that he himself doubted the integrity of Captain Gemmell. The following extract from the transcript explains the position (a condensed version appears in paragraph 347 of the Report): "You've already given evidence and stated your qualification. I think you have offered to give some supplementary evidence relating to activity at the Erebus crash site ... Our discussion with Capt. Eden last Friday indicated this would be appreciated. I think just as Capt. Gemmell was there representing the co. you were there as a rep. of ALPA.... Thats correct. May we take it that you worked in conjunction with Capt. Gemmell and other members of the team involved.... Correct. And in so doing you were present at the crash site with Capt. Gemmell.... No we had different tasks as I was in the area with Capt. Gemmell at some stages. So far as your observations are concerned what would you have to say regarding Capt. Gemmell's conduct and behaviour in the course of his duties there.... I have no reason to doubt Capt. Gemmell in any way shape or form. Have you ever suggested otherwise to anybody.... I have not." Then he was cross-examined by counsel for the Association whose witness he had been earlier. He was asked about Captain Gemmell's work at the actual scene of the disaster and his explanation about that matter is reflected in the following question and answer: "Did you see Capt. Gemmell at any time in the cockpit area or thereabouts working on his own.... I qualified that before. Working on your own is a relative term. At all stages there would be somebody adjacent for your own safety and well-being. I did not at any stage see Ian Gemmell Capt. Gemmell or Ian Wood or David Graham in total isolation in any part of the wreckage." Then there is mention of material that may have been returned by Captain Gemmell to New Zealand-- "You heard question the other day concerning Capt. Gemmell returning from McMurdo with an envelope containing property can you tell us about that.... At the stage that Capt. Gemmell was returning to N.Z. he was asked by the Chief Inspector of Accidents if he would return to N.Z. with one or more envelopes I cannot recall how many containing photos and perhaps other information to be used in the conduct of the inquiry at a later date but specifically at that early date the intention was for Capt. Gemmell to brief the Minister and the Dir. of CAD and senior execs, of Air N.Z. as to what had transpired at that early date in the investigation. As Mr Chippindale would be staying in the Ant. and the remainder of his team would be with him or else in the US. What about private property.... The envelopes which Capt. Gemmell return to N.Z. with may have contained some documentation from the crash site which was beginning to return in significant quantities from the various people on the crash site including the police." The following portion of the cross-examination then refers to documents described as "the technical crews flying records, the collection of log books, licences and other relevant documentation". He said that at first there was reluctance on the part of Air New Zealand to release this material "as it was not clear at that stage in many peoples minds what my duties were". It was not immediately appreciated that he was acting on Mr Chippindale's behalf. He was then asked-- "And Air N.Z. and Capt. Gemmell released to you the material which you'd previously sought.... Correct". Concerning all this evidence the Commissioner expressed the following conclusions in paragraph 348: "Captain Eden is at present the director of flight operations for the airline. He appeared in the witness box to be a strong-minded and aggressive official. It seemed clear from this further production of First Officer Rhodes as a witness that it had been suggested to him by Captain Eden that he should either make a direct allegation against Captain Gemmell or else make no allegation at all, and that since First Officer Rhodes seemed to have no direct evidence in his possession, he was therefore obliged to give the answer which Captain Eden had either suggested or directed. However, First Officer Rhodes was not entirely intimidated because as will be observed from the evidence just quoted, he insisted on saying that Captain Gemmell had brought an envelope containing documents back to Auckland." Those statements are in no way related to the assessment of Captain Eden's evidence or as Captain Eden as a witness. They are observations that Captain Eden had attempted to influence or direct the evidence to be given by First Officer Rhodes by a process of intimidation. Counsel for First Officer Rhodes' own association had made no suggestion to that effect. Nor is there any hint by First Officer Rhodes himself that he was present as anything but a voluntary witness. The answer he gave to the opening question would not seem to support suspicions of intimidation. And that answer is itself followed by quite a generous tribute to Captain Gemmell. But the reputation of Captain Eden and the support given Captain Gemmell is dismissed by a finding of intimidation. It should be said as well that although Captain Eden himself appeared to give evidence three days later not a word was said to him by anybody to suggest that earlier he had been guilty of attempting to intimidate a witness. Specific documents To the extent that the Royal Commission Report has pointed to any particular classes of documentary material that did not reach the Inquiry the list is not a long one. It comprises-- 1. Unidentified papers within the blue envelope--No complaint about this was ever made by Mr Chippindale as we have mentioned. 2. Papers given to First Officer Cassin as briefing material--It has been explained that if any complaint could be made about this matter it would affect Captain Crosbie, the unnamed "employee of the airline" referred to in paragraph 52. It was he who went to the Cassin home for compassionate reasons as the spokesman for the Airline Pilots Association. He denies ever receiving the material. Even if he had, the Report has not challenged the conduct of any of the line pilots. This matter would seem to be irrelevant. 3. Documents or papers that may have been shredded by Mr Oldfield following the decision of the in-house committee which met during the week beginning 3rd December 1979--This matter requires no further discussion. 4. Pages within the cover of a ring-binder notebook of Captain Collins--This matter too was handled by Captain Crosbie. However, it requires some specific mention because in paragraph 352 it has been associated with Captain Gemmell and as all counsel now acknowledge this has been done in error. The paragraph is one of the specific paragraphs challenged by these proceedings. 5. Briefing or other flight documents (including a New Zealand Atlas) taken onto the aircraft within Captain Collins' flight bag; and similar papers within a flight bag owned by First Officer Cassin--This matter also requires discussion. The Ring-binder Notebook The Commissioner found that Captain Collins carried with him on the fatal flight a small pocket diary usually kept in his breast pocket; and a ring-binder losse-leaf notebook carried in his flight bag. It is said in paragraph 351 "that the chief inspector had obtained possession of the small pocket diary, but it did not contain any particulars relating to Antarctica flights". At the hearing Mrs Collins described the diary and said that on 12th December 1979 Captain Crosbie had returned it to her together with certain other items of personal property belonging to her husband. She explained that there were no pages in the ring-binder when she received it "other than some loose papers which are still folded inside the front cover". The question arose as to what had happened, to the balance of the contents of the notebook. Captain Crosbie himself was called by counsel for the Airline Pilots Association to give evidence before the Commission. He explained that his involvement in all post-accident matters was as a welfare officer for the association; and in that capacity he had been given by the police personal property for distribution to next-of-kin. When asked about pages which normally would have been within the ring-binder covers he said that most of the recovered items had been damaged considerably by water and kerosene, and in answer to the Commissioner, who had asked "How could the ring-binder cover itself be intact and yet the pad of writing paper disappear?", he said, "I suggest the cover survived the water and kerosene but the paper contents didn't". He added in answer to questions by counsel-- "If papers were removed from the ring binder who would have done that.... I would have myself I presume. Do you recall doing that.... No not specifically. I was involved in destroying a lot of papers that were damaged and would have caused distress some because of that and some because it was the obvious thing to do." As a further sample of the kind of material that might have been provided by the criticized officers had they been given the opportunity we were referred to a signed statement by Captain Crosbie forwarded to the police (who by then were investigating the allegations of conspiracy) on 5th May 1981. In the statement he has said after he had given evidence before the Inquiry he recalled that because of the poor condition of the notebook and severely damaged paper inside it and "rather than present this to Mrs Collins" he had disposed of the pages himself. Then having cleaned the cover he dried it in the sun and returned it to Mrs Collins. It would seem to be an understandable reaction although once again the effect this kind of material might have had if it had been put forward is not for us to assess. In any event, concerning this matter the Commissioner said in paragraph 352-- "As to the ring-binder notebook, it had been returned to Mrs Collins by an employee of the airline, but all the pages of the notebook were missing. _Captain Gemmell_ was asked about this in evidence. He suggested that the pages might have been removed because they had been damaged by kerosene. However, the ring-binder notebook itself, which was produced at the hearing, was entirely undamaged." (Emphasis added.) It is clear that the Commissioner has wrongly attributed the explanation given by Captain Crosbie concerning the removal of missing pages to Captain Gemmell. The latter was never questioned at all about possible reasons for the missing pages. The fifth and sixth respondents have formally acknowledged that the reference to Captain Gemmell in that paragraph is wrong. Contents of Flight Bags It has been explained that the Commissioner was satisfied that Captain Collins had used the New Zealand Atlas to plot the last leg of the flight path from Cape Hallett to McMurdo and may have used a chart of his own for the same purpose. In addition there were his briefing documents and those received by First Officer Cassin. Those received by the latter have been discussed. The Commissioner held that they had not been taken aboard the aircraft. But he was concerned with whatever else may have been carried onto the DC10 by First Officer Cassin in his flight bag; and about the contents of Captain Collin's flight bag which he believed would include the atlas and briefing documents. In fact the only evidence concerning the possible survival of the first officer's flight bag, let alone its contents, was a name-tag which finally reached Mrs Cassin through Captain Crosbie, the welfare representative. Since there is no description of the contents and it has been held that the briefing material was left behind anyway, the fate of the bag itself would seem to be immaterial. On the other hand it is known that after the accident Captain Collins' bag was seen on Mt. Erebus. The matter has been mentioned. The bag did not reach his widow as it would normally have done if it had been received and returned to New Zealand and this fact is the focus of attention in the Royal Commission report. In order to examine the matter it will be remembered that the mountaineer, Mr Woodford, arrived by helicopter searching for survivors on the morning of 29th November. In the letter he sent to the Royal Commission he said he found the bag then and: "My recollection is that it was empty when I first inspected it. It certainly contained no diaries or briefing material." Apparently the bag had been thrown from the disintegrating aircraft at the time of impact and its contents lost in the snow or scattered by winds before the arrival of the mountaineers. But whatever the reason for their absence from the bag it is the contents that matter in this case--not the flight bag itself. And according to the letter they had already disappeared from the bag three days before the New Zealand party arrived there. So like the bag of First Officer Cassin it might be thought that this item too was immaterial. However, it is discussed by the Commissioner in the following way. First there is listed a series of documents "which clearly had been carried in the flight bag of Captain Collins" and which had not been recovered. The items comprise the New Zealand Atlas and a chart; the briefing documents; and the ring-binder notebook. Those three items have been mentioned. And finally a topographical map issued on the morning of the flight. The suggested significance of these various documents is explained by reference to the view of counsel for the Airline Pilots Association that they "would have tended to support the proposition that Captain Collins had relied upon the incorrect co-ordinates" (paragraph 344). There follows reference to the blue envelope and the matter of Captain Eden after which paragraph 349 speaks of the flight bag: "Then, as the Inquiry proceeded, there were other queries raised. It seemed that Captain Collins' flight bag had been discovered on the crash site. It was a bag in which he was known to have carried all his flight documents. It was said to have been empty when found, a fact which was incidentally confirmed by a mountaineer who had seen the flight bag before Captain Gemmell arrived at the crash site. The flight bag was rectangular, and constructed of either hard plastic or leather, and had the name of Captain Collins stamped on it in gold letters. It was evidently undamaged." There is mention as well of First Officer Cassin's flight bag and the ring-binder notebook (both of which matters have now been discussed) and then it is said in paragraph 353 that after the taking of evidence the Commissioner asked counsel assisting the Commission to make inquiries about the two flight bags "which had been located on the site but which had not been returned to Mrs Collins or Mrs Cassin". It appears from the following paragraph 354 that among others interviewed by counsel or asked for comment upon this matter were Mr Chippindale (the chief inspector of air accidents), and the senior sergeant of police who had been in charge of the property collected from the crash site when it was brought to McMurdo. It is said in that paragraph that the police officer-- "... recollected either one or two flight bags among other property awaiting packing for return to New Zealand. He said that personnel from Air New Zealand had access to the store, as well as the chief inspector, and the senior sergeant said that he thought that he had given the flight bags to the chief inspector and that the chief inspector was the sole person to whom he had released any property. The chief inspector was then interviewed on 11 December 1980 by telephone, being at that time in Australia, but he said that no flight bags were ever handed to him." Thus the inquiries that were made in this fashion were inconclusive. However, the Commissioner was satisfied that-- "The two flight bags were lodged in the Police store at McMurdo and would have been returned in due course to Mrs Collins and Mrs Cassin by the Police. But they were taken away from the store by someone and have not since been seen." (Paragraph 359 (1)) Then in the same context he said in sub-paragraph 359 (4): "Captain Gemmell had brought back some quantity of documents with him from Antarctica, and certain documents had been recovered from him by First Officer Rhodes on behalf of the chief inspector." And then-- "It therefore appears that there were sundry articles and perhaps documents which had been in possession of the aircrew which came back to New Zealand otherwise than in the custody of the Police or the chief inspector" (paragraph 360). In evidence Captain Gemmell had denied knowledge of the change that had been made to the McMurdo waypoint but the Commissioner did not accept that answer; and he is linked with the matters mentioned in paragraph 360 on the basis that he had known "about the changed co-ordinates before he went to Antarctica" and that because he-- "... plainly kept this significant fact to himself, (he) was to be the arbiter of which documents were relevant. The opportunity was plainly open for Captain Gemmell to comply with the chief executive's instructions to collect all documents relevant to this flight, wherever they might be found, and to hand them over to the airline management." The next sentence of that paragraph contains the finding already mentioned: "However, there is not sufficient evidence to justify any finding on my part that Captain Gemmell recovered documents from Antarctica which were relevant to the fatal flight, and which he did not account for to the proper authorities." At the conclusion of this section of the Report the Commissioner said that he could "quite understand the difficulty in recovering loose documents from this desolate mountain side, although the heavy atlas", he said, "was not in this category". But he stated that an opportunity had been "created for people in the airline to get rid of documents which might seem to implicate airline officials as being responsible for the disaster". And he spoke of all these matters in terms of "justifiable suspicion". The condition of Captain Collins' flight bag when it was first seen by Mr Woodford had already been mentioned. His letter dated 5th December 1980 was written immediately after some cross-examination of Captain Gemmell had been given widespread publicity and on Monday 8th December 1980 Captain Gemmell was still giving evidence. By then he was under cross-examination by counsel assisting the Commission and the latter proceeded to read into the record the text of the letter (Exhibit 266) which reads: "Dear Sir, At the time of the DC10 crash I was employed in Antarctica by D.S.I.R. as a survival instructor/mountaineer assistant. I was one of the three mountaineers who made the initial inspection of the site for survivors. I was also one of the three mountaineers who accompanied Messrs David Graham (Investigator) Ian Gemmell & Ian Wood (Air NZ) during their initial inspection of the aircraft. During the first six days after the accident I was at the crash site at all times when the site was occupied. In regard to evidence reported in the Christchurch Press today, 5 Dec 1980, I can state unequivocally that: (1) Captain Gemmell did not spend any time inspecting the aircraft without other people being present. (2) Captain Collins flight bag was found by me the day after the crash, this being three days before any Air N.Z. personnel or crash investigators reached the site. My recollection is that it was empty when I first inspected it. It certainly contained no diaries or briefing material. (3) Captain Gemmell did not remove any items from the persons of deceased lying in the area...." Counsel proceeded to read from the letter which goes on to refer to instructions concerning the crevassed area of the ice-slope. No challenge was made to the views expressed by Mr Woodford nor was he called to give evidence. And no evidence to any contrary effect was given by anybody. Yet apart from the passing reference to the matter in paragraph 349 of the Report the point of view Mr Woodford expressed seems to have been given no attention. The extent of the evidence which could have been given by Mr Woodford if he had been called as a witness is indicated by his affidavit now put before this Court. The importance of the letter seems obvious. The bag being empty when it was seen only 18 hours after the aircraft had crashed it is difficult to understand how it could have any significance when found in that same condition three days later. Yet in this part of the Report it is left as a central issue. Mr Woodford's own concern about all this is indicated in the lengthy affidavit which he prepared for the purpose of exonerating Captain Gemmell. It was sworn by him on 21st May 1981 not very long after the Report of the Royal Commission had been made public. A final comment should be made about Captain Gemmell's position. It concerns a submission made on his behalf to this Court that "In view of the 'not proven' verdict against Captain Gemmell and the various critical statements made about him it is a remarkable thing that he was given no opportunity for further comment when the Commissioner decided to make further enquiries of the police sergeant and Mr Chippindale at the conclusion of the hearing of evidence". If Captain Gemmell was to be left enveloped in "justifiable suspicion" this is something that certainly should have been done. Indeed if the post-hearing investigation had been sufficiently developed the Commissioner might have been satisfied (as now appears from the affidavit of Mr Stanton) that the police officer who gave information to counsel assisting the Commission about one or two flight bags was not even in Antarctica while Captain Gemmell was there. The affidavit indicates that the police officer arrived to take charge of the police store only on the evening of 6th December and by then Captain Gemmell had been back in New Zealand for two days. Airline's Attitude at Inquiry This matter requires brief comment. It involves the issue as to whether Air New Zealand adopted an uncompromising approach to the matters under consideration by the Royal Commission so that the proceedings were unnecessarily prolonged. Concerning the matter the Commissioner said this in the Appendix to the Report dealing with the awards of costs, which must be mentioned later: "In an inquiry of this kind, an airline can either place all its cards on the table at the outset, or it can adopt an adversary stance. In the present case, the latter course was decided upon. The management of the airline instructed its counsel to deny every allegation of fault, and to counter-attack by ascribing total culpability to the air crew, against whom there were alleged no less than 13 separate varieties of pilot error. All those allegations, in my opinion, were without foundation". The general complaint that Air New Zealand had adopted an adversary approach and withheld evidence until a late stage needs to be assessed against the control exercised by counsel assisting the Commission concerning the order in which witnesses were to be called and the way in which the Inquiry progressed. Before the initial hearing to settle questions of procedure he supplied the airline with a "Memorandum as to areas to be covered by Air New Zealand evidence". It is dated 13th June 1980 and specifies 21 topics. Then on 19th June he circulated a "Memorandum to counsel engaged in the DC10 Inquiry" advising that the parties were to prepare initial briefs which he would then put in sequence. And at the preliminary hearing on 23rd June it was arranged that a basically chronological order should be followed after Mr Chippindale had been called as the first witness. On the following day counsel for the Civil Aviation Division took issue with the requirement that its brief of evidence should be handed in before Mr Chippindale had appeared and the Commissioner ruled that briefs of evidence would be withheld until shortly before the witness was to be called. Mr Chippindale's evidence occupied the first fortnight of the inquiry and thereafter the actual order in which the witnesses were to be called was arranged by counsel assisting the Commission who stated in advance the days and times at which those concerned should come forward. Thus the first Air New Zealand witness to give evidence was the chief engineer who appeared before the Inquiry on 22nd July. It was said that the airline had not been invited through its counsel to make its position known by means of an opening address at the commencement of the public hearing. No doubt the Commissioner would have permitted such an address but the occasion for it did not seem to arise and he himself did not require the matter to be dealt with on this basis by any of the parties. And in the result witnesses were called from among the personnel of the airline in order to deal with various questions in an ordered fashion. Thus it was not until all evidence had been called that counsel for the various parties made submissions to the Commissioner. At the conclusion of the evidence counsel for the airline invited counsel assisting the Commission to inform him what were the main issues upon which closing submissions were requested. However the extended written answer to that enquiry includes no suggestion whatever that the conduct of airline witnesses or the post-accident conduct of the employees was in issue. And the Commissioner himself said this in paragraph 375 about the airline's submissions: "... counsel for the airline adopted, in the course of their detailed and exemplary final submissions, the very proper course of not attributing blame to any specific quarter but leaving it to me to assemble such contributing causes as I thought the evidence had revealed." In that regard some of the statements which were made on behalf of the airline are not unimportant. At one point counsel said-- "By now it should be apparent to the smallest mind that the Company has not espoused, and does not espouse, a proposition that the accident can be contributed to a sole cause, let alone a sole cause of pilot error. If from the evidence adduced, there emerges or is implicit a criticism of the Company's flight crew, that criticism has been moderate, informed and responsible." And in the same context-- "I would, with respect, also remind Your Honour that in the very nature of these proceedings there has not been an opportunity for a formal opening where one might have expected just that. But I would further suggest, Sir, that the evidence advanced by the Company, which has been in an attempt to bring every witness who can contribute something towards the causal factors and everything else has been done, not selectively, and there have been witnesses who have plainly, unequivocally, acknowledged their fault, their error. There has not in any way been a parade of witnesses all seeking to criticize the flight crew and thus, as it were, exonerate themselves. There has been an endeavour, without selection, to reveal all the evidence to reveal all the documents ...". This statement by senior counsel for the airline as to the manner in which he had attempted to handle his responsibilities should be enough to answer the complaint in the Appendix that "The management of the airline _instructed its counsel_ to deny every allegation of fault, and to counter-attack by ascribing total culpability to the air crew". The tribute the Commissioner paid counsel in paragraph 375 (the same counsel appeared in this Court for the applicants) is not altogether consistent with those last remarks. In any event the appendix continues-- "Apart from that, there were material elements of information in the possession of the airline which were originally not disclosed, omissions for which counsel for the airline were in no way responsible, and which successively came to light at different stages of the Inquiry when the hearings had been going on for weeks, in some cases for months." A final comment should be made about the criticisms of the airline concerning the position it adopted concerning pilot error as a cause of the accident. In the course of his evidence (at p. 272) Mr. Chippindale was asked by the Commissioner: "Was not the position Capt. Collins must have clearly have thought he was flying toward McMurdo over McMurdo Sound?" He said, "It is my belief that this could be the only possible reason for him to continue". That is an important answer. It means that in this respect Mr. Chippindale had reached the same conclusion as the Commissioner but for general reasons of logic whereas the latter was influenced by his finding that Captain Collins had made use of the New Zealand Atlas or a chart in order to plot the position of the waypoint and the route to be taken by the aircraft. But although this general conclusion about McMurdo Sound was shared it is at this point that the two investigations diverged in terms of pilot responsibility for the accident. The Commissioner was of the opinion that until the last moment the pilots believed they were flying in clear air; that they were deceived by a whiteout situation; and that it was understandable that they flew on at 2000 and then 1500 feet. Mr. Chippindale was aware of and spoke in his report about the whiteout phenomenon, but after giving evidence before the Royal Commission for eight days he still adhered to his conclusion of pilot error for reasons he expressed (at p. 274) in the following way: "I believe that the cause as it stands (in the Chief Inspector's report) is reasonable. As I attempted to clarify last time the pilot has descended to 2000 ft and evidently is unable to see anything ahead. I say 'evidently' because there is a snow slope leading to a mountain rising to 12 450 feet and that was directly in front of him. He 'popped down', to use his own words, another 500 feet and continued to progress towards an ice cliff which is 300 feet high, the lower 50 per cent of which is solid and bare rock. And still he didn't perceive anything to persuade him to divert from his track. To me this indicates it was an area of poor definition and as such he would not be able to discern what he could expect to see had he been, as various people suppose, believing that he was proceeding down the McMurdo Sound. The sea ice is by no means uniform in texture and during his descent he would have seen the nature of the sea ice--in fact the photos from the passengers indicate that it had large breaks in its surface and was quite easily discerned so therefore I believe at the end of his descent to 2000 ft he was confronted with a very vague area in front of him which he may or may not have believed was cloud, and when descending a further 500 feet the view ahead of him would have been of equally poor definition. Despite this, he continued to the point of 26 miles from destination as indicated presumably on the AINS." Mr. Chippindale's opinion has some background relevance in the present case. It is in no way relevant because it differs from that of the Commissioner upon the issue of causation. Already we have emphasized and we do so once again that what was said in the Royal Commission Report about the cause or causes of the accident must stand entirely unaffected by these proceedings. But the opinion has some relevance because although it was wrong, as the Royal Commission Report decided, the Commissioner certainly did not consider it to be anything other than a completely conscientious and honest attempt by Mr. Chippindale to analyse and draw a rational conclusion from all the available facts. He described Mr. Chippindale as a model witness. In the circumstances it is difficult to understand why the same point of view Mr. Chippindale expressed in his evidence could not be genuinely shared by other educated observers. We turn now to the relief sought by these various officers and the airline itself. The Claim for Relief The applicants seek relief in the form of an order that the findings be set aside or for a declaration that the various findings are invalid or made in excess of jurisdiction; or were made in circumstances involving unfairness and breaches of the rules of natural justice. In addition we are asked to make an order quashing the decision of the Commissioner that the airline should pay to the Department of Justice the sum of $150,000 by way of costs. Earlier in this judgment we have said that if the challenged findings were made without jurisdiction or contrary to natural justice then it would be possible for the Court to take steps by way of declaration to offer at least some form of redress. And we went on to explain why we think the Royal Commission was bound by the broad requirements of natural justice. As an example of what would be required to meet obligations of fairness we then referred to the need for a reasonable opportunity of meeting unformulated suspicions of deception and concealment that had been in the Commissioner's mind. However, before we turn to the natural justice part of the case it is convenient to consider the claim of excess jurisdiction, and that by confining our attention to the terms of reference. The submission of counsel for the sixth respondent is that the statements contained in each of the two paragraphs 348 and 377 are relevant to and justified by the following items of the terms of reference: (g) Whether the crash of the aircraft or the death of the passengers and crew was caused or contributed to by any person (whether or not that person was on board the aircraft) by an act or omission in respect of any function in relation to the operation, maintenance, servicing, flying, navigation, manoeuvring, or air traffic control of the aircraft, being a function which that person had a duty to perform or which good aviation practice required that person to perform? (j) And other facts or matters arising out of the crash that, in the interests of public safety, should be known to the authorities charged with the administration of civil aviation in order that appropriate measures may be taken for the safety of persons engaged in aviation or carried as passengers in aircraft. In its essentials the argument is that in order to answer the questions posed by paragraph (g) the Commissioner found it necessary or was entitled to explain the process by which he reached his final conclusions; that in doing so he was entitled to comment upon the quality of the evidence that was given in the course of the Royal Commission Inquiry; that the assessment of witnesses was a necessary part of the findings he reached as to the cause of the accident; that the assessment was not a part of the substantive findings of the Commission; and "whether having reached his conclusion he expresses himself vehemently or refrains from pungent comment is entirely a matter for him". Similar submissions were made in relation to the second cause of action and natural justice. In certain circumstances it is obvious enough that reasons for rejecting evidence would not merely be relevant but often a necessary part of a decision. But considerations of that kind are far removed from the conclusions expressed in paragraph 377. There it is said that the ten senior members of this airline had been involved in organized deception. "Palpably false sections of evidence ... a pre-determined plan of deception ... an attempt to conceal a series of disastrous administrative blunders ... an orchestrated litany of lies". These are unlikely phrases to associate with a mere assessment of the credibility of witnesses. In the Courts it is constantly necessary to indicate a preference for the evidence of one witness or to make a decision to put evidence completely to one side; sometimes it even seems necessary to describe evidence in terms of perjury. But in the Courts Judges always attempt to be most circumspect in handling issues of this kind, particularly if misconduct seems apparent which is not immediately associated with the central issues in the case. There can be no less reason for circumspection in the case of a Royal Commission at least where the terms of reference do not directly give rise to inquiries into criminal dealing. In _Re The Royal Commission on Licensing_ (1945) N.Z.L.R. 665 Sir Michael Myers C.J. dealt with the point in the following way (at p. 680): "A Commission of Inquiry under the statute and a Royal Commission under the Letters Patent are alike in this respect--each of them is an inquiry, not an inquisition. By that I mean that the Commission is not a roving Commission of a general character authorizing investigation into any matter that the members of the Commission may think fit to inquire into and that the ambit of the inquiry is limited by the terms of the instrument of appointment of the Commission." It must always be sensible for any Commission of Inquiry or other tribunal to keep those words in mind. We are satisfied that the findings contained in each of paragraphs 348 and 377 are collateral assessments of conduct made outside of and were not needed to answer any part of the terms of reference. The Commissioner had no authority or jurisdiction to deal with the affected officers in such a fashion and the findings themselves are a regrettable addition to the Report. Fairness The concept of natural justice does not rest upon carefully defined rules or standards that must always be applied in the same fixed way. Nor is it possible to find answers to issues which really depend on fairness and commonsense by legalistic or theoretical approaches. What is needed is a broad and balanced assessment of what has happened and been done in the general environment of the case under consideration. In the present case the expressed complaints turn upon the absence of warning that the affected officers were at risk and that the critical decisions taken against them were unsupported by any evidence of probative value. But in estimating the significance of these complaints it would be unreal to ignore the fact that the findings are not only very serious in themselves: they are made more potent by the way they have been so closely associated with one another. Furthermore, each of them is advanced in this Report as an overt manifestation of one general conspiracy. That last matter has special importance because for the reasons just explained we have held the conspiracy findings to be unjustified. They should never have been made. In saying that we do not overlook the fact that this Court is making an assessment in isolation from the viva voce evidence given at open hearings of the Inquiry. But the present issue is simply whether the affected officers were or were not deprived of the advantage of answering unformulated charges. In such a situation the advantage of actually hearing and seeing a witness is hardly a relevant consideration. In the course of the survey that has been made up to this point we have commented upon the nature and significance of the various challenged paragraphs in the Report. It is unnecessary to traverse the same subject matter once again and we simply remark that the applicants have justified their complaints concerning the way in which the findings have been reached. Award of Costs We have explained earlier in this judgment that an order for costs was made against Air New Zealand in favour of parties other than the Civil Aviation Division. As a matter of company policy the airline decided that it would comply with that order although in doing so it has made no admission that the order was validly made. In addition, however, the airline was ordered to pay the Department of Justice the large sum of $150,000 by way of contribution to the public cost of the inquiry. It is that last order which is challenged in the present proceedings on two grounds. The first is that the award involved a wrong exercise of the discretion provided by s. 11 of the Commissions of Inquiry Act 1908. The second ground is that in any event no award greater than $600 could be made by reason of Rule III of rules made in terms of the statute and gazetted on 11th February 1904. The reasons given by the Commissioner for making the respective orders against Air New Zealand are set out in a passage from the appendix to the Report which is mentioned in this judgment under the heading "Airline's attitude at Inquiry". And on behalf of the Attorney-General it is said that the discretion was properly exercised for reasons expressed to be related to "conduct at the hearing (which materially and unnecessarily extended the duration of the hearing)[2]". However, the reasons given[3] by the Commissioner do not stop there. The appendix goes on-- "The management of the airline instructed its counsel to deny every allegation of fault, and to counter-attack by ascribing total culpability to the air crew ... Apart from that, there were material elements of information in the possession of the airline which were originally not disclosed ... it was not a question of the airline putting all its cards on the table. The cards were produced reluctantly, and at long intervals, and I have little doubt that there are one or two which still lie hidden in the pack." When discussing the legal implications of the order for costs under that particular heading earlier in the judgment we stated that on purely verbal grounds it might be possible to draw refined distinctions between parts of the Report which are highly critical of the position taken up by the airline at the inquiry on the one hand and the effect this had on the duration of the hearing on the other. But there can be no doubt that in the context of this Report and the conclusions reached by the Commissioner concerning conspiracy and otherwise any ordinary reader would feel satisfied that the imposition of an order for costs in the sum of $150,000 was nothing less than the exaction of a penalty. In those circumstances and by reason of the conclusions we have reached concerning the invalidity of the challenged paragraphs we are satisfied that the order must be set aside. Concerning the second ground advanced on behalf of the airline it is sufficient to say that even if it had been appropriate to make an award of costs in this case the amount was limited to the modest sum of $600. At the beginning of this judgment we said that we had felt it necessary to go at some length into the facts. This we have done both in order to analyse the important questions raised in the areas of natural justice and excess of jurisdiction and also because we have thought it to be in the public interest to attempt to explain the factual issues that are involved in the proceedings. We now express our conclusion that for the reasons already given we are satisfied that the complaints of the applicants are justified. Against that finding we return to the beginning of this judgment where we said that we felt sure that reputation can be vindicated and the interests of justice met by a formal decision of this Court that will have the effect of quashing the order of the Commissioner requiring Air New Zealand to pay costs in the large sum of $150,000. We would make an order accordingly. The Court being unanimous as to the result there will be an order quashing the order of the Royal Commissioner that Air New Zealand pay to the Department of Justice the sum of $150,000 by way of contribution to the public cost of the Inquiry. There have been no submissions concerning the costs of the present proceedings and that matter is reserved. _Solicitors_ Messrs. Russell, McVeagh, McKenzie, Bartleet & Co. of Auckland for appellants. Crown Law Office, Wellington, for first, fourth and sixth respondents. Messrs. Keegan, Alexander, Tedcastle & Friedlander of Auckland for fifth respondent. P.D. HASSELBERG, GOVERNMENT PRINTER, WELLINGTON, NEW ZEALAND--1982 76534J--82PT TRANSCRIBER'S NOTES There were no footnotes in this text. The following correction have been made. [Transcriber note 1: The original has here a double "the" which seems superfluous in the context.] [Transcriber note 2: In the original, the closing bracket is missing.] [Transcriber note 3: In the original, the word "give" instead of "given" is used.] 
25244	----	None 
39714	----	[Illustration: Sears] =owners manual= D.C. POWERED TIMING LIGHT MODEL 161.2158 FOR 12 VOLT IGNITION SYSTEMS +--------------------------------------------------------------------+ | To achieve efficient and economical engine operation, the ignition | | system must be timed in accordance with the manufacturer's | | specifications. Since ignition timing is also affected by the | | dwell angle, it is necessary to use a dwell meter to set the dwell | | angle to the manufacturer's specification before using the timing | | light to time the engine. | | | | | | The information in this manual will serve as a general guide for | | engine timing. | | | | CONSULT THE OWNER'S MANUAL OF THE VEHICLE BEING TESTED | | FOR SPECIFIC INFORMATION ON DWELL ANGLE AND ENGINE TIMING. | +--------------------------------------------------------------------+ ---------------------------------------------------------------------- =SEARS, ROEBUCK AND CO. U.S.A.= CHICAGO, ILLINOIS 60684 ---------------------------------------------------------------------- PRINTED IN U.S.A. 2-1329 =RULES FOR SAFE OPERATION= 1. Set the parking brake and place the gear selector lever in Park position on automatic transmissions or in Neutral on manual transmissions. 2. Operate the vehicle in a well ventilated area to avoid danger of carbon monoxide poisoning. 3. Be careful when testing an operating engine--stay away from the fan blades, drive belts, high voltage spark plug wires and hot exhaust manifold. 4. Be careful when working near the battery. Do not short the Positive terminal to ground. DO NOT LOOK DIRECTLY AT THE LENS OF THE TIMING LIGHT WHEN IT IS OPERATING. =PRELIMINARY= 1. Consult the vehicle's service manual for instructions regarding vacuum connections and specific timing procedures. 2. With the engine stopped, clean the dirt from the timing marks. 3. Set the engine idle speed to the vehicle's specification with a tachometer. 4. Check the distributor dwell angle and adjust to the manufacturer's specifications, if necessary, before timing the engine. =HOW TO CONNECT= 1. With the engine off, connect the BLACK clip to the battery NEGATIVE (-) terminal. 2. Connect the RED clip to the battery POSITIVE (+) terminal. 3. Consult the vehicle's service manual for the location of the spark plug in number 1 cylinder. Disconnect spark plug wire and attach adapter to the spark plug. Connect the spark plug wire to the adapter. Fasten GREEN clip to the adapter. 4. Optional hookup: The adapter may be placed in the distributor tower for the number 1 cylinder. Attach the GREEN clip to the adapter and connect the spark plug wire to the adapter. [Illustration: Consult the vehicle's service ENGINE BLOCK manual for the location of No. 1 spark plug. NO. 1 CYLINDER / /---Adapter--=/= / / Sears GREEN / / Timing ---------/ / #1 Spark Plug Wire Light : / / \ : or / | | : / | | : | | | : | | | | | Other | | : | | | | | Spark Plug | | ADAPTER-=| | | | | Wires | | /---------\ / \ | | RED BLACK #1 Cylinder (+) (-) Distributor Tower +============+ | Auto | | Battery | | | +============+] =ENGINE TIMING= 1. Start the engine and allow it to warm up. 2. After the engine is warm, operate it at idling speed or the RPM specified in the vehicle manual. 3. Aim the timing light at the timing marks, press the switch to operate the timing light and observe the timing mark. The position of the timing mark must agree with the manufacturer's specification. If it does not, reset the timing as follows: 4. Stop the engine. Loosen distributor hold-down device (consult service manual for specific method). Distributor should be just loose enough to permit rotating the distributor body by hand. 5. Restart the engine. Slowly turn the distributor in the correct direction in order to line up the timing marks. 6. When the specified timing marks are in line, stop the engine and securely tighten the distributor hold-down device. 7. Restart the engine and recheck the timing. 8. Stop the engine, disconnect the timing light, remove the adapter from No. 1 spark plug or distributor tower and replace the spark plug wire securely. Transcriber's Notes The diagram showing how to hook up the Timing Light was reproduced. Although not officially a part of the original publication, the sales receipt was included and as the date and price information may be of interest, it was converted into an electronic version: +-------+ | Sears | SHIPPER COPY +-------+ SEARS, ROEBUCK AND CO. +------+------+----+------+------+----+----+--------------+-----------+ |S.R.C.|C.L.C.|S.C.|E.A.A.|M.C.A.|CASH|DIV.|SALES| DATE | 8340512 | | | | | | | X | 28 | 2568| 9/18/76| | +------+------+----+------+------+----+----+-----+--------+-----------+ |ACCOUNT | SELLING STORE NO. | |NUMBER +--------------------+ +------------------------------------------------+ | |NAME +--------------------+ |(PRINT) [Name Withheld] |No. Or Name Of Store| +------------------------------------------------+ Carrying Account | | +--------------------+ |ADDRESS | | +------------------------------------------------+--------------------+ | | APPROVAL | |CITY Emp # 03970 | | +------------------------------------------------+--------------------+ This purchase is made under my Sears Charge Security Agreement or my Sears Revolving Charge Account and Security Agreement for the credit sales price consisting of the cash price plus the finance charge. This order is subject to the approval of the Credit Sales Department of Sears, Roebuck and Co. Purchased By: [Name Withheld] ====================================================+================== DESCRIPTION | CASH PRICE ----------------------------------------------------+------------------ | | | 2568 EMP | CA 28 DIV | 2158 MDSE | 16.99+* | 16.99+S 10.000%DISC | 1.70- | 15.29+S 8.000%TAX | 1.22+ | 16.51+S 6241153244028 | 16.51+T 9 18 76 | | | | | [] FLOOR | [] DOCK | [] WHSE. | [] __________ Thank You for shopping at Sears PLEASE RETAIN THIS COPY FOR COMPARISON WITH YOUR MONTHLY STATEMENT, OR IN CASE OF RETURN, OR EXCHANGE. 16045 Rev. 6-72 (S.C.) PRINTED IN U.S.A. 
23581	----	* * * * * +-----------------------------------------------------------+ | Transcriber's Note: | | | | Inconsistent hyphenation in the original document has | | been preserved. | | | +-----------------------------------------------------------+ * * * * * OPPORTUNITIES IN AVIATION OPPORTUNITY BOOKS OPPORTUNITIES IN AVIATION BY LIEUT. GORDON LAMONT CAPTAIN ARTHUR SWEETSER OPPORTUNITIES IN THE NEWSPAPER BUSINESS BY JAMES MELVIN LEE OPPORTUNITIES IN CHEMISTRY BY ELLWOOD HENDRICK OPPORTUNITIES IN FARMING BY EDWARD OWEN DEAN OPPORTUNITIES IN MERCHANT SHIPS BY NELSON COLLINS HARPER & BROTHERS, NEW YORK ESTABLISHED 1817 [Illustration: At work on one of the F-5-L type of seaplane at the Naval Aircraft Factory, League Island, near Philadelphia. The F-5-L is one of the largest type of naval seaplane, and flew from Hampton Roads, Va., to Rockaway Naval Air Station, L.I.] OPPORTUNITIES IN AVIATION By Captain ARTHUR SWEETSER U.S. Air Service Author of "_The American Air Service_" and GORDON LAMONT, Late Lieutenant in the Royal Air Force, Canada Frontispiece [Illustration] HARPER & BROTHERS _Publishers_ New York and London Acknowledgement is made to the _New York Evening Post_ for some of the material which first appeared in its columns. OPPORTUNITIES IN AVIATION Copyright, 1920, by Harper & Brothers Printed in the United States of America Published, January, 1920 To that great new gift which is so soon to come to us, this little book is enthusiastically dedicated by the authors. CONTENTS CHAP. PAGE INTRODUCTION i I. WAR'S CONQUEST OF THE AIR 1 II. THE TRANSITION TO PEACE 11 III. TRAINING AN AIRPLANE PILOT 24 IV. SAFETY IN FLYING 39 V. QUALIFICATIONS OF AN AIRPLANE MECHANIC 52 VI. THE FIRST CROSSING OF THE ATLANTIC 63 VII. LANDING-FIELDS--THE IMMEDIATE NEED 76 VIII. THE AIRPLANE'S BROTHER 85 IX. THE CALL OF THE SKIES 96 ADDENDUM 107 INTRODUCTION Any ordinary, active man, provided he has reasonably good eyesight and nerve, can fly, and fly well. If he has nerve enough to drive an automobile through the streets of a large city, and perhaps argue with a policeman on the question of speed limits, he can take himself off the ground in an airplane, and also land--a thing vastly more difficult and dangerous. We hear a great deal about special tests for the flier--vacuum-chambers, spinning-chairs, co-ordination tests--there need be none of these. The average man in the street, the clerk, the laborer, the mechanic, the salesman, with proper training and interest can be made good, if not highly proficient pilots. If there may be one deduction drawn from the experience of instructors in the Royal Air Force, it is that it is the training, not the individual, that makes the pilot. Education is not the prime requisite. Good common sense and judgment are much more valuable. Above all, a sense of touch, such as a man can acquire playing the piano, swinging a pick, riding a bicycle, driving an automobile, or playing tennis, is important. A man should not be too sensitive to loss of balance, nor should he be lacking in a sense of balance. There are people who cannot sail a sail-boat or ride a bicycle--these people have no place in the air. But ninety-nine out of one hundred men, the ordinary normal men, can learn to fly. This has been the experience of the Royal Air Force in Canada. There will be as much difference between the civilian pilot, the man who owns an airplane of the future and drives it himself, and the army flier, as there is now between the man who drives his car on Sunday afternoons over country roads and the racing driver who is striving for new records on specially built tracks. If aeronautics is to be made popular, every one must be able to take part in it. It must cease to be a highly specialized business. It must be put on a basis where the ordinary person can snap the flying wires of a machine, listen to their twang, and know them to be true, just as any one now thumps his rear tire to see whether it is properly inflated. The book, in a large sense a labor of love, is the collaboration of an American officer of the United States Air Service and another American, a flying-officer in the Royal Air Force. If the Royal Air Force way of doing things seems to crowd itself to the fore in the discussion of the training of pilots, the authors crave indulgence. In a subject which lends itself dangerously to imagination, the authors have endeavored to base what they have written, not on prophecy, but on actual accomplishments to date. The latter are indeed so solid that there is no necessity for guesswork. Aviation has proved itself beyond peradventure to those who have followed it, but up to the present the general public has not sufficiently analyzed its demonstrated possibilities. The era of the air is undoubtedly at hand; it now remains to take the steps necessary to reap full advantages from it. ARTHUR SWEETSER, GORDON LAMONT. OPPORTUNITIES IN AVIATION I WAR'S CONQUEST OF THE AIR The World War opened to man the freedom of the skies. Amid all its anguish and suffering has come forth the conquest of the air. Scientists, manufacturers, dreamers, and the most hard-headed of men have united under the goad of its necessity to sweep away in a series of supreme efforts all the fears and doubts which had chained men to earth. True, years before, in fact, nearly a decade before, the Wright brothers had risen from the ground and flown about through the air in a machine which defied conventional rules and beliefs. The world had looked on in wonder, and then dropped back into an apathetic acceptance of the fact. Despite the actual demonstration and the field of imagination which was opened up, these early flights proved to be a world's wonder only for a moment. For years aviation dragged on. Daredevils and adventurers took it up to make money by hair-raising exploits at various meets and exhibits. Many died, and the general public, after satiating its lust for the sensational, turned its thought elsewhere. Flight was regarded as somewhat the plaything of those who cared not for life, and as a result the serious, sober thought of the community did not enter into its solution. Business men held aloof. Apart from circus performances there seemed no money to be made in aviation and consequently practically none was invested in it. What little manufacturing was done was by zealots and inventors. Workmanship was entirely by hand, slow, amateurish, and unreliable. Strangely enough, scientists were equally apathetic. It might have been expected that their imaginations would be fired by the unexplored realms of the air and by the incomparably new field of experiment opened to them; but they were not. The great question, that of flight itself, had been answered, and but few were interested in working out the less spectacular applications of its principles. Aviation remained very much of a poor sister in the scientific world, held back by all the discredit attaching to the early stunt-flying and by failure to break through the ancient belief in its impracticability for any purposes other than the sensational. So the science limped along, unsupported by either public interest or capital. Now and again some startling feat attracted the world's attention, as when the English Channel was first crossed by air and England was made to realize that her insularity was gone. For a moment this feat held public interest, but again without a true realization of its significance. There seemed nothing which would drive man to develop the gift which had been put within his reach. Up to that fatal moment in August, 1914, when the World War broke out, aviation had made but little progress. All nations had what passed as air services, but they were very small and ill-equipped and were regarded with doubt and suspicion by the military leaders of the various countries. Compared with what has since taken place, the experiments previous to the war were only the most rudimentary beginnings. Then came the war. Man's imagination was aroused to a feverish desire for the development of any device for causing destruction. Conventions, usages, and prejudices were laid aside and every possibility of inflicting damage on the enemy was examined on its merits. Sentiment or any regard for personal danger involved was thrown to the winds. Science was mobilized in all lines in the struggle to keep one step ahead of the enemy. Almost immediately aviation challenged the attention of the responsible leaders. The handful of French planes which in those early fateful days of August penetrated up into Belgium brought back the information of the German mobilization there, and this led to the rearrangement of French forces in preparation for the battle of the Marne. As a result aviation at once leaped into high repute for scouting purposes and the foundations were laid for its great development. But as aviation had proved itself in the warfare of movement leading down to the Marne and sweeping back later to the Aisne, so it proved itself in the French warfare which was so unexpectedly to follow. When the two opposing lines were so close together that they locked almost in a death grip, each side kept such strict watch that ground observation was greatly hampered. Apparently there was only one way to find out what was going on behind the enemy's lines. That was by looking from above. The first aviator, therefore, who sailed into the air and spied the enemy introduced one of the most important developments in the strategy of modern warfare. Thereupon began one of those silent battles of the rear, of which we see and hear so little, but which indeed decides sometimes far in advance of the actual test of battle just which side is going to win. Scientists, inventors, manufacturers, and practical fliers began coming together in increasing numbers to exact from this latest method of warfare its last degree of usefulness. In the studies and factories on both sides of the lines men dedicated themselves to the solution of the problem of flight. Stage by stage the difficulties were overcome. First it was the Germans who with their terrible Fokker planes harnessed the machine-gun to the airplane and made of it a weapon of offense. Then it was the Allies who added the radio and made of it an efficient method of observation and spotting of artillery fire. Increased engine-power began to be developed, and bombs were carried in ever-increasing numbers and size. The moment an enemy plane fell on either side of the line the victors gathered about their prey with a keenness which could come only of the hope that they might find in it some suggestion that would make their own flying more efficient. Each learned from the other, so that the different schools on either side of the line had all the advantage of watching the development of their rivals. Very shortly after an improvement appeared on one side it reappeared in the planes of the other side. It is doubtful if ever a more desperate scientific battle was fought than that which featured the development of the air services of the various belligerents during the war. Control of the air was so vital that neither could afford to overlook any possibility; and, as a result, the scientific evolution was truly astounding. No man was reserved on this subject of airplane improvement. All contributed their best skill and ability to the common reservoir of knowledge. Very soon man's conquest of the air became so complete that different types of planes were developed for different kinds of work. The plane of the early days which wandered off by itself wherever it saw fit, gathered what information it could, and returned to drop a note to the commander below, developed into a highly efficient two-seated plane equipped with machine-guns for protection against attack, wireless for sending back messages, and cameras for photographing the enemy's positions below. The plane which had earlier dropped an occasional bomb in a hit-or-miss fashion over the side now developed either into a powerful two-seater with a great weight-carrying capacity and a continually more efficient scientific method of aiming its missiles or into a huge machine for long-distance night-bombing work capable of carrying from two to a dozen men and from two to four tons of bombs. During this time the strictly fighting plane, usually a single-seater, increased in speed, "ceiling," and agility till it could dart, twist, and dive about, three to five miles above the trenches, protecting friendly bombing and observation planes below from enemy attack or swooping down to send enemy planes in flames to the ground. Vital though all this work was for the war, it had an incomparably greater value for the perpetual struggle which all mankind is waging against nature. While the various nations were seeking to destroy one another through the air, they were in reality destroying the chains which bound them to the ground and winning their freedom in a new element. The advance which the Allies or the Germans made over each other in scientific aerial development was a joint advance over the restrictions of gravitation. This, indeed, apart from the spread of democracy and internationalism, may well stand out in history as the war's richest heritage. Problems which had been considered insoluble were solved. The casting aside of all conventions, all restrictive habits of thought, all selfishnesses, and the focusing of the highest scientific ability in a struggle which might mean the life or death of the nation, had brought as a by-product a development beyond our wildest fancies. Aerial operations in any future war, however, will have at once a problem which has only recently and in very much smaller degree confronted the navy, namely, the assurance of attack not only on the front, in the rear, and on both flanks, but from above and below as well. Recently the navy has had to face that problem--submarines operating below and airplanes above; but the problem of attack upon a ship is not so serious as upon an airplane. Already, in order to meet this danger of attack from every possible direction, a most complete strategy and system of formations have been worked out. In this way the various types of planes operate in different air strata according to their missions, the upper planes echelon somewhat behind those below on the order of a flight of steps facing the enemy. This system provides a quick method of reception of an attack and the assurance of quick support, no matter where the attack may come. Obviously there would be nothing in all of warfare on either land or sea comparable to a collision between two such aerial fleets. The speed of the lighter planes, quick, life-taking duels in several different strata at once, would provide a clash of action, speed, and skill far more beautiful and yet in many ways far more terrible than anything ever recorded in the history of war. Fleets of the skies--who shall attempt at this day of the infancy of the science to limit their scope? Aerial battle-planes of colossal size and power are as certain to come in time, and in not a very long time, as the dreadnought of to-day was certain to follow the first armored ship of only a half-century ago. Never yet has man opened up a new avenue of war that he has not pursued it relentlessly to its final conclusion. It is certain that he will not fail to push aerial development with all the energy with which he has devoted himself to the science of destruction. The avenue of the seas has been up to now the world's greatest civilizer. Very shortly, without doubt, it will be replaced by the avenue of the skies. If we are to strive for freedom of the seas, what shall we say about freedom of this new element? The laws of aerial travel and aerial warfare open an unlimited field of speculation. II THE TRANSITION TO PEACE Developments during the war, despite their startling sensational character, had, however, been so overshadowed by human suffering and desperation that but few minds were awake to the changes that were to influence man's future. Amid the disasters, battles, and unprecedented movements in the politics of nations, the achievements of flight could command but a passing notice. People looked and wondered, but were distracted from following their thoughts through to the logical conclusion by the roar of a seventy-mile gun, the collapse of a nation, or the shock of battle on a one-hundred-mile front. Let us, however, weave together a few things that were done in those days of sensation, which may have a particular effect on the future of the science. Most conspicuous, perhaps, was the obliteration of distance and of all the customary limitations of travel. German airplanes in squadrons penetrated into snug little England when the German fleet stood locked in its harbor. The Italian poet D'Annunzio dropped leaflets over Vienna when his armies were held at bay at the Alps. French, British, and finally American planes brought the war home to cities of the Rhine which never even saw the Allied troops till Germany had surrendered. None of the conventional barriers stood in the way of these long trips. A new route of travel had been opened up along which men flew at will. The boundary-lines of states below, which look so formidable on the map, were passed over with the greatest ease, as well as such natural obstacles as the Alps and the English Channel. Tremendous saving in time was constantly being effected. Men were able to dart back and forth from the front to the rear and from England to France with a speed never dreamed of by other means of travel. To be sure, the front-line demands for planes were too severe to allow a very wide use in this way, but nevertheless the possibilities were there and were constantly availed of.[1] Indeed, the British early established a communication squadron for this specific purpose. In the last three months of the war 279 cross-country passenger flights were made to such places as Paris, Nancy, Dunkirk, and Manchester, all of them without a single accident! Moreover, a Channel ferry service was created which in seventy-one days of flying weather made 227 crossings, covered over 8,000 miles, and carried 1,843 passengers. With trains seldom going above 60 miles an hour, the slowest airplane went 80 and the average daylight plane on the front probably equaled 110. The fast fighters went up to 120, 130, and even 140 miles an hour, over twice as fast as any method of travel previously known. Just as the curtain closed on the war, there had been developed in the United States a plane credited with 162-2/3 miles an hour, and no one for a moment believed that the limit had been reached. Altitude likewise had been obliterated. The customary height for two-seated observation and bombing planes was between one and two miles, and of single-seated scouts between two and four miles. These altitudes were not the freakish heights occasionally obtained by adventurous fliers; on the contrary they were the customary levels at which the different kinds of duties were carried out. Many men, of course, went far higher. Since then an American, Roland Rohlfs, flying a Curtiss "Wasp" set the unofficial altitude record at 34,610 feet--higher than the world's highest mountain. Life at these altitudes was not possible, of course, under ordinary conditions. The temperature fell far below zero and the air became so thin that neither man nor engine could function unaided. As a result the fliers were kept from freezing by electrically heated clothing and from unconsciousness from lack of air by artificially supplied oxygen. Similarly the oil, water, and gasolene of the engine were kept working by special methods. The armistice threw the different nations into a dilemma as to their aviation plans. Obviously the huge war planes which were still in the building in all the belligerent countries were no longer necessary. Almost immediately, therefore, the placing of new contracts was halted by the various governments, enlistments stopped, and plans set in motion for the new requirements. Within a very short time the United States canceled several hundred million dollars' worth of contracts on which little actual expenditure had been made by the manufacturers. Shipments of men and planes overseas were of course brought to an end and at the same time arrangements were made for bringing back from France the great aerial equipment mobilized there. Indeed, the air service units were among the first to be returned, especially the labor and construction troops in England. Nevertheless, military aviation of the future was definitely safeguarded. A bill was presented to Congress for an aerial force of 4,000 officers and 22,000 men, a fitting contrast to the force of 65 officers and 1,120 men with which the country had entered the war. Certain flying fields and schools which had shown the greatest value in the past and promised most for the future were definitely designated for permanent use, and especial effort was made to keep in the service the best of the technical experts and designers who had helped to solve America's problems of the air. Abroad demobilization was less rapid, as it was in all other lines. The British, who had given particular thought to after-war aviation, immediately turned to converting all their valuable war material and experience into a national force which should assure England of the supremacy of the air as well as strength in her supremacy of the seas. France, the custodian of Germany's great aerial force, found more than enough work for all her men in taking care of the hundreds of surrendered machines. Both nations at the same time took long steps toward building up the civil machinery necessary for private, non-military flying. For several months, of course, there was a hiatus. Thought had been so concentrated on military aviation that the conversion to peace work proved slow. Only the most general plans had been made in any of the countries, and those by ardent supporters of aviation, who were forced to make the most earnest efforts to obtain consideration of the subject in the midst of all the vital problems of peace and reconstruction. Greatest of all the difficulties was that, as private flying had been prohibited during the war, there were, with the coming of peace, no rules and regulations ready for it. Also many great projects for international flights had to be postponed because of complete lack of international rules in this respect. Nevertheless, most spectacular and convincing flights followed one another in rapid succession. The most outstanding of these flights was, of course, the first crossing of the Atlantic by seaplane--a triumph of organized effort by the navy. At the same time all over the world flights took place with astounding frequency which illustrated, as little else could, the certain future of aviation. Seas, mountains, deserts, places otherwise almost impassable were traversed with ease and speed. Army fliers flew from the Atlantic to the Pacific within a few months of the signing of the armistice. It required but fifty hours of flying-time, just a fraction over two days. At that time no attempt was made to obtain speed, as the purpose of the trip had been to locate landing-fields and make aerial maps for future transcontinental flights. The four planes that made this trip might be considered as the pioneers of vast flocks of airplanes which within a short time will be winging their way from coast to coast. If, with machines built specifically for war purposes and with no special landing-fields or routes laid out, aviators could successfully travel from one coast to the other in fifty hours of flying-time, how much more rapidly will future trips be made when special touring-planes have been developed, routes and landing-fields are laid out, repair-shops are built, and the trip becomes a matter of routine rather than aerial experiments. The effect that this new method of travel will have on American life and development is staggering to the imagination. San Francisco and New York will be almost neighbors, while Chicago and New Orleans will be but a pleasant day's trip apart. The business man, the statesman, and even the courier can be transported from one end of the country to the other, independent of steel rails and other devices, in record time. Such experiments have already proved successful in Europe. The British Foreign Office in London, anxious to keep in close touch with the Peace Conference at Paris, turned to the airplane to assure quick transportation of men and documents. The slow train trip with the irksome transfer to and from the Channel steamer and the more irksome voyage across the Channel itself, were avoided by a special service through the air. Thus two great capitals were brought within a few hours' time of each other, which greatly facilitated the vital negotiations under way. Civilians were finally granted the right to make the trip under military supervision. Fourteen passengers were transported from Paris to London in two hours and forty minutes as against six hours and forty minutes, the fastest time ever made by any other means of travel. Each of them had twenty pounds of luggage, and luncheon of cold ham and champagne was served on board over the Channel, followed by a game of cards. It was easily demonstrated by the return trip that men could leave either capital after breakfast, have several hours in the other, and return home for dinner. Then a French flier with six passengers made the flight from Paris to Brussels. The time consumed between the two capitals was but two hours as against over five by the ordinary train travel. As an instance of some of the problems which this particular flight brought about, it was observed that a Belgian policeman approached the plane as it was about to leave and inquired for passports and papers. Everybody made excuses for not having them. The policeman refused to allow the airplane to leave. Finally the pilot, losing his patience and temper, started the motor and flew off before the angered official knew what had happened. Two other French aviators about the same time crossed the Mediterranean from France to Algiers and back in the same day. Though unequipped with seaplane devices, they started out with full confidence that their motors would carry them over the water. With only their navigating instruments and an occasional vessel to guide them, they reached their destination after a perfect trip and created a great sensation among the natives who came down to see the airplanes alight. Far more spectacular, however, was the flight made from London to Delhi. A Handley-Page machine, which had flown from London to Cairo during the war and taken part in the final military operations against the Turks, left Cairo, on November 30th, shortly after the armistice. Five and three-quarter hours later the airplane with five passengers reached Damascus, a trip practically impossible except through the air because of the ravages of the war. At 7.40 the next morning they set out again, flew northeast along the Jebel esh Shekh Range to Palmyra, then east to the Euphrates, down that river to Ramadi, and thence across to Bagdad, a flight of 510 miles made in six hours and fifty minutes without a single stop, part of it over country untrod even by the most primitive travelers. Thence they went on _via_ Bushire, Bander Abbas, Tcharbar, and Karachi to Delhi, where they received a tremendous ovation as the first fliers to arrive from the home country. From Delhi they continued on without mishap to Calcutta. This distance from Cairo to Karachi, 2,548 miles, was made in thirty-six hours' flying-time; from Karachi to Delhi the distance is 704 miles, and from Delhi to Calcutta 300, a total of 4,052 miles from the main city of Egypt to the greatest commercial port of India. No route had been surveyed, no landing-places obtained, no facilities provided. Territory inaccessible to ordinary travel, land where the white man is almost a stranger, was crossed. Yet it was all done as part of the day's work, in no sense as a record-breaking or spectacular trip. The certainty of flight from London to India was demonstrated. A bi-weekly service for both passengers and mails was at once planned. Almost immediately preparations for the route were worked out, twenty-five airdromes and landing-fields were designated, of which the main ones would be at Cairo and Basra on the Tigris, with subsidiary fields at Marseilles, Pisa, or Rome, Taranto, Sollum, Bushire, Damascus, Bagdad, Bander Abbas, Karachi, Hyderabad, and Jodhpur. It is estimated that the flight of 6,000 miles, at stages of about 350 each, would take seven or eight days as against the present train and steamer time of five or six weeks. At the same time another route far shorter than that which would be necessary by following the sea route lies over Germany, Russia, and the ideal flying-land along the Caspian Sea, Krasnovodsk, Askabad, Herat, Kandahar, and Multan. As with Asia Minor and Asia so with Africa, the British at once made plans for aerial routes. Only a few weeks after the armistice announcement was made of plans for an "All Red Air Route" from Cairo across the desert and the jungle to the Cape. This could all be done over British territory, with the part over Lakes Victoria Nyanza and Tanganyika covered by hydroplanes. The moment men were released from the war, surveying of this route was begun and tentative plans made for landing-fields every 200 miles over the 5,700-mile trip. The air is ours to do whatever we can with it. There must be developed a large interest in this country in the business of flying. We must make the air our third, fastest, and most reliable means of communication between points in a way to compete with transportation on land and sea. The airplane, instead of being the unusual thing, must become a customary sight over our cities and villages. The first step in the development is the training of airplane pilots and mechanics. FOOTNOTES: [1] Some of the British statesmen flew to and from the Peace Conference in Paris. III TRAINING AN AIRPLANE PILOT Any ordinary, active man can fly. That is to say, any man with nerve enough to take a cold bath or drive an automobile down Fifth Avenue can maintain himself in the air with an airplane, and turn into a good pilot with practice. In other words, the regular man who rides in the Subway, who puts on a straw hat on May 15th or 20th, as the case may be, has not only the right to be in the air, but owes it to himself to learn to fly. Any one with a reasonable amount of intelligence can be made a good pilot. He need not hold a college degree, or even a high-school diploma, tucked away in some forgotten place. If he has the sense of touch of the normal man, the sense of balance of a normal man, can skate, or ride a bicycle, he should be in the air, flying. There is a difference between the war or army pilot and the peace-time flier yet to be developed. War flying calls for highly trained men, a man who has proved himself fit for combat under all conditions, a man who can shoot straight, think quickly, and turn immediately. He must possess a little more than the average nerve, perhaps, or he must be trained to the point where shooting and maneuvering are the natural reactions to certain circumstances. He must be able to stand altitudes of 20,000 feet; he must be quick with his machine-gun, have a knowledge of artillery, and know, in fact, a little about everything on the front he is trying to cover. This requires training and aptitude. The day is coming for the man who wants to make a short pleasure flight, or go from town to town, touring by air. He need know nothing of machine-guns or warfare. He may never want to do anything more hazardous in the way of maneuver than a gentle turn. His maximum altitude would be perhaps 8,000 feet. He would in all probability be flying a machine whose "ceiling" was 10,000 feet, and he might never care to tour at a height higher than 2,000 feet. There is no reason why he should go high. One can have all the thrills in the world at 2,000 feet, follow the ground more easily, without wasting time or gasolene in attempts to fly high enough so that the earth looks like another planet below. Let us illustrate a bit from the Royal Air Force of Canada, which is as good as any other example. The experience of the flying service of one country has been essentially that of another country, and we Americans may yet learn of the air from the English. In England the air is just another medium of travel, as much a medium as the ground and water--but that is, of course, another story. In 1917 the Royal Flying Corps, later incorporated into the Royal Air Force, came to Canada to take up the instruction of Canadian boys for flying in France. Americans enlisted with the pick of the Canadian youth, and droves were sent overseas. Very soon the cream had been skimmed off and there came a time when material was scarce. Meanwhile the war raged, and there was no option but to take drafted men from all sections, Montreal in particular. Many could not speak intelligible English, and few had enjoyed any educational advantages. The men who came as cadets to be trained as pilots in 1918 graded much lower in personal and physical qualifications than the type of the previous year. And yet these same drafted men, who had withstood for three and a half years the call of their country, had more control over their machines at the end of their course than the men of the year before. At the end of four, five, or six hours' solo these men could do all the high maneuvers, commonly thought dangerous, such as the barrel roll, the loop, the stall turn, the Immelmann turn. An astounding showing compared to the boys of 1917, who were forbidden to stunt and who rarely disobeyed the orders. In our American service we had specially selected men. They were college men, tested, qualified, and picked. But our men--and it's no reflection on them--seldom did their higher maneuvers with less than fifty hours of solo flying. There is just one answer--it is a matter entirely of training. It might be said that the Canadian casualties on the Texas flying-fields near Fort Worth during the winter of 1917-18, when the Royal Air Force occupied two airdromes, were the cause of comment all over the country. There were fifty fatalities in twenty weeks of flying, and machine after machine came down in a fatal spinning-nose dive, or tail spin, as the Americans speak of the spin. Shortly after the Royal Air Force returned to its airdromes in Canada in the middle of April the Gosport system of flying training, which had been used successfully in England, was begun on the Curtiss J.N. 4B-type training-plane. The result was an immediate and material decrease in fatal accidents. In July, 1918, there was one fatality for every 1,760 hours of flying, and by October fatalities had been reduced to one in every 5,300 hours of flying. That is a remarkable achievement, as official data from other centers of training show one death in a flying accident for every 1,170 hours. Briefly, the Gosport system is a graduated method of flying instruction. The cadet is led by easy steps through the earlier part of the training, and only after he has passed aerial tests in the simpler methods of control is he allowed to continue with the rest of his course and "go solo." The scheme provides that before he goes solo he must have spun, and shown that he can take his instructor out of a spin. Only then is he considered fit to go on his own. "Dangerous" and "Safe" as terms to describe flying technique gave way to wrong and right. There was built up under sound instruction one of the best schools of flying in North America, the School of Special Flying, at Armour Heights, Ontario. There is no reason why there should not be established in this country a number of such schools, under men who have had army experience, to train great numbers of civilian fliers within the next few years. There is going to be a strong demand for the best flying instruction that can be given. It should be noted that only the most perfect system of flying instruction should be used, for the best is safest, and the safest, no matter how expensive, is comparatively cheap. There is no reason why there should be an extended period of ground instruction for the non-military pilot of the future. He should be taught the elementary principles of the theory of flight, should know something about the engine with which he is going to fly, and understand some things about the rigging of his airplane. The details could come to him in constant association with the airplane before, during, and after each flight. No time need be spent on such subjects as artillery observation, machine-gunnery, wireless, bombing, photography, patrol work, and other subjects of a purely military nature, on which so much stress has been laid in training army pilots. "What is an airplane?" Before going ahead with the method of Gosport instruction every pupil is given a lecture on the ground in which he is asked that question. One definition which was passed out to us in Canada was, "An airplane is a machine...." At this point the flight sergeant in charge of rigging would look dreamily into the distance. "An airplane is a machine...." he would begin again with an air of utter despondency. That was certainly no news to cadets. They had an idea that it might be a machine, and wanted to know more about it. "An airplane is a machine with lift-generating surfaces attached to a frame which carries an engine, fuel, aviator, and devices by which he steers, balances, and controls his craft," the mournful flight sergeant was finally able to convince them. Lift-generating surfaces--these are the bases of all flying. Every one knows, for instance, that a paper dart, instead of falling directly to the floor, sails in a gliding angle for some distance before crashing. Lift is generated under those plane surfaces moving through the air--and the lift keeps that paper dart gliding. Little eddies of air are compressed under its tiny wings. Imagine an engine in the dart, propelling it at some speed. Instead of having to nose down to get enough speed to generate lift under its wings, the dart would be able to fly on the level, or even climb a bit. Just so with an airplane. A gliding airplane about to land with power shut off is that paper dart on a large scale. The airplane flying is the dart with power. To make the airplane safe to fly, to give control to the pilot so that he may steer it where he wants to, there is a rudder, moved by a rudder-bar under the foot of the pilot. It is impossible to turn a swiftly moving airplane in the air by the rudder alone. It must be banked to prevent skidding, even as a race-track is banked high on the turns. On its side an airplane will cushion its own bank of proper degree by the use of ailerons. These ailerons are sections of the wing-tips which may be moved either up or down. They are counterbalanced so that movement of the left down gives you the right aileron up. With left aileron down, the lift of the left wing is increased, and it tips up; at the same time the lift of the right wing is decreased, and it sags down. In that way the airplane is tipped up for a bank. These ailerons, wing sections, really, are controlled by a device known as the joy-stick in the cockpit. We have seen how an airplane is made to tip and turn. Before a machine is under control we must be able to climb, or come down to the ground for a landing. Vertical control of an airplane is attained by the use of elevators, flaps on the tail plane acting as horizontal rudders. A pull-back on the joy-stick lifts the flaps, raises the nose of the machine, and causes it to gain height. Push the joy-stick forward, the elevators are turned down, and the machine goes into a dive for the ground. In making many maneuvers all three controls, rudder, ailerons, and elevators, are used at once and the pilot feels his way with the machine, guiding it with the stick and the rudder-bar. After the explanation of the use of these controls, and their demonstration on the machine as it awaits its turn in the air, the pupil is taken up for his first ride--strictly a joy ride, and not always joyous for those who take every chance to be seasick. After he has a glimpse of what the ground looks like from the air, and has recovered from his first breathless sweep off the ground, the pupil is given a lesson in the demonstration of controls. The instructor explains through a speaking-tube attached to his helmet the very simple principles. Forward with the stick to nose down, back to lift it up, left stick tilts the machine over on its left wing, and right stick banks it to the right. Right stick and right rudder, in proper proportions, turn the machine to the right, left stick and left rudder to take the machine out of the turn and fly it straight again. Then the wonderful moment when the instructor calls through the tube, "All right, now you take the stick." You clutch it as though it were the one straw in a great ocean. "Not so hard," comes the voice. "Now put your feet gently on the rudder-bar. Not so rough; easier, man, easier on that stick!" For a glorious moment she is yours, you hold her nose up, and you are flying an airplane tearing over the checkerboard country far below. Then, like the voice of doom: "Now, do a gentle turn to the left. Don't forget to give her rudder and stick at the same time. That's right. Begin the motion with your feet and hands at the same time." The world swings furiously, and down below that left wing-tip a little farm sways gently. "Now you are in a gentle turn--feel that breeze on your cheek? We are side-slipping; give her a touch more of left rudder. Not so much. Now your nose is dropping; pull back on the stick. Back! Not _forward_! _Back!_ Now your nose is too _high_; take us out, and don't forget that _opposite_ stick and rudder. "Now fly straight for a few minutes. Your right wing is low--bring it up. Your nose is too high. Now it is too low. Keep it so that the radiator cap is above the horizon. That's right." So goes the business of instruction through the lessons on straight flying, gentle turns, misuse of controls, side-slipping, and approach, take-off, and landing. The trips should average thirty-five or forty minutes, long enough to teach the lesson, but not long enough to weary the pupil. Here at take-off and landing the pupil finds himself up against the most difficult part of his training. He has the problem of stopping a large machine weighing a ton or more, traveling at a landing speed of forty to fifty miles an hour, with the center of gravity just balanced over the under-carriage. An error in judgment will pile the machine up on its nose with a crashed propeller, and perhaps two broken wings and damaged under-carriage. Not a dangerous accident for the pilot, but very humiliating. Army practice has shown that a pupil should have about sixty practice landings dual, that is to say, coached and helped by his instructor. By this time he has a total flying time of six to twelve hours. At this point, before he goes solo, the Gosport system provides that he shall be taken to a reasonably safe height for the practice of high maneuvers. At a height of say two thousand five hundred feet the instructor shows him how a stalled machine falls into a spin. The question of teaching higher maneuvers to civilian pilots is open to argument. As soon as the instructor shuts off the engine the machine rapidly loses flying speed. It reaches a point where there is not enough air passing over the wing surfaces to support the plane in the air. Her nose begins to drop, and he pulls the stick back. The stick is full back, she stalls, topples over on her side, and plunges nose first. The instructor kicks on full rudder, and the world whirls below like a top, and the air whistles, swish, swish, swish, in the wires at every turn. Stick forward, opposite rudder, and she comes out so fast that your head swims. That is the spin. "Now you try it," says the instructor. For there is nothing to a spin unless a machine does not come out of it--a rare thing if the plane is properly handled. The pupil is now ready to go solo, and for the first couple of hours' solo flying he does nothing but make circuits around the field, landing and taking off. Then his instructor takes him dual for forced-landing practice, business of getting down into a field within gliding range by gliding turns. Then the pupil tries it solo, throttling down for the practice, a most valuable experience which increases the confidence of the pilot. He learns to use his own judgment and to gauge height and ground distance as it appears from the air. After three or four hours of solo time the pupil is scheduled for another demonstration of higher maneuvers, spinning and the stall turn. For the stall turn the pilot noses the machine down to get an air speed of seventy-five miles an hour. A little bank, stick back, she rears into the air with her nose to the sky and propeller roaring. Full rudder and throttle off. In silence she drops over on her side into the empty air; blue sky and green fields flash by in a whirl. She hangs on her back while the passengers strain against the safety belts, and then her nose plunges. The air shrieks in the wires as the ground comes up at terrific speed. It is time for the pupil to go up for his solo spin under the plan adopted for army purposes. Up, up, up the pupil flies, three thousand feet, and the ground below looks soft and green. Would it be soft to hit in a spin from that height? It would not. Have people ever spun that far? he wonders. They have. Have machines ever failed to come out of a spin and killed the pilot? The answer is too obvious. With faith in nothing in particular, and with his mind made up that one can die but once in a spin, he stalls and spins her--and comes out. He is so surprised and exhilarated that he tries it again before he loses his nerve. Yet again. The pupil is a pilot, the air has no terrors, and he has learned the oldest truth of flying, that there is nothing to a spin unless you don't come out. The natural result of training a pupil along those lines is that he graduates rapidly into a good stunting pilot. He realizes that he cannot tempt the devil at three hundred feet and hope to live, but he takes a good altitude, throws his machine upside down, and knows that, given enough air, he must come out. He does come out unless he loses complete control of his mind and body. With fifteen hours of solo flying the pupil has really become a pilot. He is beginning to show that he can control his machine. From then on it is a question of the polishing of the nice points, making his forced landings perfect, not side-slipping a foot on his vertical banks, and coming out of spin so that he always faces the airdrome--all of which distinguish the good pilot from the poor pilot. IV SAFETY IN FLYING The fatalities on the training-fields of every country during the period of training in war, and before and after the war, testify only too surely that flying cannot be absolutely safe. It is no reflection on the future of flying to realize that it has not been safe, and that it can never, perhaps, be made fool-proof. One or two things must be remembered before we become despondent over the future safety of flying. When the United States entered the war the entire personnel of the Signal Corps numbered one hundred and sixty officers and men. At the time the armistice was signed more than thirty thousand pilots had been trained. They were trained in great numbers under high pressure. We did not have the machines to train them in or the instructors to fly with them. We had not the experience in wholesale training of flying-men, and yet we turned out vast numbers. It was a question of getting the men through their flying and getting them overseas as quickly as possible. We had no adequate methods of inspection of machines, and no laid-out course in flying-training. We had to learn by our own experience, in spite of the fact that England at all times gave unstinted aid. The wonder is really that we did not have more flying accidents. There were few men in the country who really understood what conditions tended toward a flying accident. There were few who had ever gone into a spin and lived to tell about it. At that time a spinning-nose dive was a manifestation of hard luck--like a German shell. If you once got into it, it was only the matter of waiting for the crash and hoping that the hospital might be able to pull you through. Toward the end, of course, this situation had been largely overcome, the Gosport system of flying had been tried out, and there was a vast increase in the knowledge of flying among the instructors and pupils. The spin had been conquered, training was on a sound basis, and accidents were being rapidly cut down. One of the most obvious ways to cut down crashes was by making sure that the pilot was in good condition physically. Flight surgeons assigned to every camp were detailed to make a study of the very delicate relationship between a sick and stale pilot and the crash. It was discovered, for instance, that a man who went up not in the best condition multiplied by many times the ordinary hazards in the air. It became the duty of these surgeons to conduct recreation and exercises so that pilots would always be in good trim. Flying for an early solo pupil is the greatest mental strain that a man can experience. Every moment the fact that he is up in the air, supported only by wood, wires, and fabric, may be on his mind. He is making desperate efforts to remember everything his instructor has told him since he started his dual. He tries to keep that nose on the horizon, the wings balanced, and the machine flying true. He is in fear of stalling and consequent loss of control. He goes into his turns, hardly knowing whether he is going to come out of them, and noses down for a landing, mentally giving prayer, perhaps, that he will come out all right. He can't possibly remember everything he has been told, but he tries to salvage as much knowledge as possible to make a decent landing. These experiences tend to bring about two conditions, aerophobia (fear of the air) and brain fatigue, both resulting in complete loss of head on the part of the pilot and inability to react to impulses. Nothing is more likely to produce immediate and fatal aerophobia than the sickening sight from the air of a crash, yellow wings flattened out against the green ground a thousand feet below. A comrade, a tentmate? The pupil looks at his machine, sees the wires throbbing, and watches with wonder the phenomenon of rushing through the air--he may let his imagination dwell too long. During his first hour's solo a swift stream of hundreds of impulses is borne along the nerve centers to the brain of a pupil. It is like the pounding of heavy seas against a light sea-wall. His brain reels under the repeated shocks and the pupil falls into a detached stupor. He waits while his engine throbs ahead, and lets the machine fly itself. He seems to take no active participation in the operation, and unless he recovers control of his brain and his machine it is a crash. Physicians then have the problem of learning from a dazed and perhaps badly injured man how it happened. He can recall nothing, and seldom knows when he lost control. These are the things that happened when this country was hastening fliers overseas. As a matter of national necessity it was essential that as many men as possible be put through their dual and solo flying and sent across to the other side. It was better for the country at large to turn out five hundred pilots a month, say, with 5 per cent. of casualties, than one hundred a month with one-half of 1 per cent. or less of accidents. These figures do not represent the actual conditions, but they picture the problem. Now the civilian who would take up flying has just as much time as he wants to spend in learning to fly. He is paying for his instruction, and he should continue it for perhaps fifteen to twenty hours of dual instruction. He should fly the machine with an instructor in it, and really get accustomed to the feel of the air. He should become sensitive enough so that he can differentiate between the tight, firm touch to a machine flying under complete control and the slack movement of stick and rudder of a plane very nearly out of control. He should recognize these danger signs and know how to correct his flying position. Dual flying should be continued up to the point where the pupil flies without thinking, when it becomes the natural thing for him to use both stick and rudder to correct a bump, and when he thinks no more of it than riding over a rut in a road. He should be able to tell by ear, when volplaning, whether or not he is maintaining sufficient speed to hold it in the air. He should be acquainted with the principle of spinning, and should have had some experience in taking a machine out of a spin. The treacherous thing about a spinning-nose dive is that, to come out of it, a pilot must put his stick forward, not hold it back, in spite of the fact that the machine is falling nose first and spinning at the same time. A spin is possible only from a stall, and only when the stick is back and rudder in either direction is given. The position is an easy one to get into from a steep turn. Air resistance against a machine turning becomes greater, it slows down the speed, decreases the lifting power of the planes. The result is that the nose falls slightly. The pilot moves the stick back to lift the nose, and in doing so pulls up his elevators, offering still more resistance to the air, and checking the speed. The effect becomes cumulative; he tries to hold up his machine, and he has stalled. In a last effort to check the spin he kicks on the rudder, and the thing is done. The rudder and elevators have formed a pocket in the tail plane, which is like the spoon on a trolling-hook. The pocket is off-center and the air rushes into it as the machine topples over and plunges down. It imparts a twisting motion, which in a turn or two develops into a throbbing spin. Picture the pilot, trying to lift the nose of his machine by holding his stick well back and wondering why the nose does not come up. The pathetic thing is that so many hundred men have thought their salvation was to hold the stick back. The only possible thing to do in this case is to break the pocket. Put the stick forward to neutral, or even farther if need be, and opposite rudder. The machine will come out in three-quarters of a turn with practice, into a straight-nose dive. Then ease the stick back, and this time the nose comes up and the machine flies on its course. Instructors who have taught their pupils this before they let them go solo have saved many, many lives. It is reasonable to say that there are no fatal accidents except those from a spin, but, like all general statements, that is open to contradiction. A nose-high side-slip may be fatal, but generally the pilot pulls himself out of it. There may have been men killed in landing accidents, but one seldom hears of them. Men have been killed trying to loop off the ground, and Vernon Castle was killed doing an Immelmann turn at fifty feet to avoid another machine. These are the exceptions. The common or garden variety of accident is from a spin. The spin once conquered, the air is conquered. One hears about stunting, and the accidents which result from taking chances in the air. There may be two opinions about whether for the flying of the future it should be necessary to loop, to roll, to half roll, and stall turn, or even to spin. As to looping and rolling, the question of the type of machine to be flown will determine that largely. There are many machines which cannot be looped. The large naval flying-boats, for instance, describe a circle two thousand feet in diameter for each turnover--it is almost obvious that not much stunting is done on these boats. A small scout or sporting plane can loop and come out higher than it went in. There is certain value in practising such maneuvers if the machine will permit it. In battle they are, of course, essential. In peace, however, they may be valuable for the very fact that it accustoms a pilot to unexpected changes in the air. He gets used to the idea that he can pull himself out of any position, given air enough, and he will never be afraid. He becomes orientated on his back, does not lose his head, and simply waits with confidence for his machine to come around. This means that if he is suddenly overturned by accident, or for a minute or two loses control, he knows that his condition is temporary and that he must simply "carry on." Army pilots who have had a good course in stunting would certainly recommend the same for civilian pilots. That does not mean that it would be necessary, or even advisable. There have been accidents due to stunting by both inexperienced and experienced pilots. Generally it is a matter of altitude, for with sufficient height the greenest pilot can come out of anything, if he does not lose his head. For the man who would be the pilot for a large commercial plane, such as the Glenn Martin bomber, the Super Handley-Page in England, or the Naval Curtiss flying-boats, no stunting is necessary. He may sit in the cockpit of his machine, and ramble off mile after mile with little motion, and with as little effort as the driver of a railroad locomotive. He has a large, steady machine, and there will be no obligation for him to spill his freight along the course by turning over in midair. Whatever opinions may be held regarding the advisability of teaching stunting to a civilian pilot, there can be no question that a civilian pilot must have a long and thorough course in the very gentle but essential art of making forced landings. The problem is that of controlling a machine with its engine cut off, to have complete control of it within the radius of its gliding distance. Again, the dart gliding to its uncertain landing. In the hands of an unskilled pilot, an airplane gliding without power is a very dangerous thing. He may pile up the machine against some farm-house, fence, haymow, or clump of woods, smashing it badly and injuring himself. Or he may, through inexperience, lose flying speed in the course of his descent and topple over into a spin. Even the best pilot may make a mess of his machine if his engine goes "dud" over a forest, city, swamp, or other impossible landing-place. It is his business more or less to keep clear of such tracts when flying. But one of the tests of a good pilot is whether or not he can shut off his engine in the air, pick out his particular field below, taking into account that he must land against the wind, then by a series of gliding turns find himself just coming out of the last turn in front of the fence. He may make a gentle little "zoom" over the fence, using every last bit of flying speed for the last kick, and settle down gently on the other side. One test of instructors in Canada, before they were allowed to take up pupils, was to make three perfect forced landings in succession--one of them as the pilot came out of the spin. With his head still reeling he must pick out his landing-place and make it. The difficulty is, of course, not to undershoot, to fall short. It must be remembered that in case of actual engine failure there is no motive power, and if a man calculates his distance too short, he has nothing left but to make his landing where he may be. He has lost his height and his chance to reach other fields. He may find himself rolling into the fence of the field he was trying for. Or, equally bad, he may overshoot. The distance was shorter than it looked, he has more height to lose than he thought. He can gain nothing by sticking the nose down, because in his plunge he gains speed which will carry him too far on the ground. He may bowl over the fence, or, if there is a field beyond, make the next field. More often he finds himself in a patch of woods with a broken airplane. It is possible that on a turn, a gliding turn with the engine shut off, the pilot may lose his flying speed. Unless he is experienced, he does not realize that on a turn the machine presents more surfaces to the air and greatly increases the air resistance. It is likely to stall unless a safe margin of speed is maintained. The dangerous part of this is that very often the machine will lose its speed when only a hundred feet from the ground, approaching the field. There is no chance to pull it out of a spin unless the pilot is alert and realizes that he has lost speed, and noses down before he spins. Often he spins, and a fall with an airplane from a hundred feet is just as nasty as it can be. For his own safety in the air the civilian who is about to take up instruction in flying should insist at his flying-school that he be taught thoroughly, to his own satisfaction, the control of his machine with the engine shut off for the moment. There is a certain feel, a sing in the wires, he must know. He should continue at the work of forced landings, going on his solo flights to various heights, pick out his field, shut off the motor, and get down into that field--no other. He should keep it up until he can make nine out of every ten absolutely perfect, and the tenth one, though not perfect, still a good landing. Then it may be said that a pilot is safe. When he knows in his own heart that nothing can happen to him which will throw him off his guard, or which will worry him, he can take the air without fear. V QUALIFICATIONS OF AN AIRPLANE MECHANIC What chance has a good automobile man who knows his engine thoroughly to become an airplane mechanic? There can be only one answer to this question which men ask themselves daily--there is every chance in the world. Commercial flying, in the day when the air is to become a medium of transportation, just as ground and water are at present, must draw to itself hundreds of thousands of mechanics. The only thing to which the future of flying may be compared is the automobile industry at present. And the only place from which the mechanics are to be recruited are from the men who are working in garages putting automobiles in order. An interesting comparison between the future for the automobile mechanic or airplane mechanic compared with the future for the pilot is afforded in the figures of a well-known flying-officer of great vision. He expects that the skilled mechanic, the man who has spent years at his trade, will command more for his services than a pilot. Any one can learn to fly an airplane in one or two months of proper training. A mechanic may work for years to learn his profession. It was estimated that it took ten mechanics of various kinds on the ground to keep one airplane pilot flying in the air, and the experience of the United States has shown that there must be a large force of trained men to keep up flying. The present leaders of the automobile world and the aeronautical world are men who got their first interest in mechanics in some little shop. Glenn H. Curtiss and Harry G. Hawker, the Australian pilot, both owned little bicycle-repair shops before they saw their opportunity in flying. Most essential of all, for the man who would become an airplane mechanic, is a thorough knowledge of gasolene-engines. This should include not only a knowledge of such fundamentals as the theory of the internal-combustion engine, carburetion, compression, ignition, and explosion, but also a keen insight into the whims of the human, and terribly inhuman, thing--the gasolene-motor. Nothing can be sweeter when it is sweet, and nothing more devilish when it is cranky, than an airplane engine. There are certain technical details which distinguish an airplane motor from an automobile motor, but a man who knows automobile engines can master the airplane motor in short order. Generally speaking, the airplane motor differs from the automobile motor in shape. The Liberty type of engine is V-shaped, with both sets of cylinders driving toward a common center, the crankshaft. Most airplane motors have special carbureters, and their oiling systems are extremely finely adjusted to take up any friction at their high speed. They will be found to be lighter in weight, with pistons, piston heads and other parts made of aluminium. They are, as a rule, more carefully made than most automobile motors, with especial attention to the fitting of all working parts. One advantage which an airplane mechanic has is standardization, which has reached a high point with Liberty, Hispano-Suiza, and Curtiss engines. Once a mechanic has learned his type he has learned practically every engine of that type. For a long time to come the 18,000 Liberty engines which this country had at the time the armistice was signed will be carrying commercial airplanes across broad stretches of the United States. If it had not been for the pressure of the war this engine might have been developed slowly, as the automobile engines were, with changes from year to year. The Liberty engine has reached a high standard of efficiency, and is likely to be the standard airplane engine in this country for several years to come. An airplane mechanic who knows his Liberty engine will be able to look after most of the airplanes with which he will come into contact. An engine which was not developed to the same high point in this country as the Liberty motor is the rotary engine, of which the Gnome Monosoupape or Clerget are perhaps the best-known types. These were favorites with airmen flying fighting scout-planes. They weighed practically nothing, for an engine. A one-hundred-horse-power motor weighed only two hundred and sixty pounds, and it was a splendid type for fast work. Briefly, the power generated by the explosions in the cylinders, operating against two centers of pressure, gave a rotary motion to the cylinders and crankcase, revolving around a stationary, hollow crankshaft. Cylinders and crankcase were bolted together, and the cylinders looked like the blades of an electric fan. There was always an odd number of cylinders, so that there would be no dead-centers, no point at which two opposing strains would be balanced, causing the engine to stop. The propeller was bolted on a nose cap which revolved with the engine. This type of engine is not likely to be used to any extent for commercial flying, or even flying for sport. It is expensive, very wasteful of gasolene and oil, and difficult to keep in repair. For men who may have had some experience in the assembly of airplanes at factories, or of rigging them at flying-fields, there is great opportunity. Expert riggers who know their craft are few and hard to get. They are invaluable for maintaining a machine in flying condition. The use of airplanes in this country will require men for rigging, for truing up the wires and struts. Each airplane must be overhauled after a few hours of flight to discover hidden weaknesses and to tighten sagging wires. Rigging an airplane has some resemblance to rigging a ship for sailing. The first requisite is to see that the machine is properly balanced in flying position. There is a number of minute measurements which come with the blue-print of every machine and which must be followed out to the letter to get the most successful results. An important detail is the pitch of the planes, or the angle of incidence, as it is called. This is the angle which a plane makes with the air in the direction of its motion. Too great a pitch will slow up the machine by offering too great a resistance to the air; too small an angle will not generate enough lift. The tail plane must be attached with special care for its position. Its angle of incidence must exactly balance the plane, and it must be bolted on so that there is no chance of it cracking off under strain. Radio operators will be in great demand for flying. Brig.-Gen. A.C. Critchley, the youngest general officer in the British service, who was a pilot in the Royal Air Force, said that the future development of the airplane must go hand in hand with the development of wireless communication. He added that the most difficult thing about flying, especially ocean flying, was to keep the course in heavy weather. There are no factors which will help a man on "dead" reckoning; and a shift in wind, unknown to the navigator of a plane, will carry him hundreds of miles from his objective. The wireless telephone was used to some extent during the war for communication between the ground and the air; it will be used to a greater extent in the next few years. Another development which is being used by the navigators flying the Atlantic is the radio compass. This instrument may be turned toward a land or sea wireless station, of which the call is known, and it will register the bearing from the flying-boat to this station. It may be turned upon another station, and this bearing also charted. The intersection of these two wireless compass bearings gives the position of the ship at sea. The radio compass is dependable day or night, and is said to be quite as reliable as a sextant or other navigating instruments. Sailmakers to repair airplane fabrics, to sew new covers for planes--these men must find an opportunity in flying. There are literally thousands of wings, as yet unmade, which will carry the air traffic of the future. It matters not whether men or women take up this branch of the work, it must be done, and done with a conscience. Like all other branches of the mechanical maintenance of an airplane, careless work on the part of a sailmaker may mean disaster for the pilot. One of the latest fatalities at a Long Island flying-field was due to careless stitching, or weakness of fabric, which gave way under great pressure due to high speed. The linen cover of an upper plane ripped off at a height of one hundred and fifty feet, and the pilot was killed in the fall of the machine. Photographers may yet take the place of surveyors, or work hand in hand with them in the making of aerial maps of the country. The map of the future must be an aerial map, a mosaic map such as was used by our army headquarters. Nothing can exceed the eye of the camera for accuracy. Cameras bolted to airplanes, such as were used by our army for reconnaissance, have already been used for mapping cities. The mapping of the entire country in such a manner is only a matter of time. One thing which an aviation mechanic of any sort must bear in mind is that he _must_ do his work with a conscience. True, he is handling mute metal engines, or dumb wires and struts--but in his work he holds the life of the pilot in his hand. It is not too much to say that hundreds of pilots' lives have been saved by the conscientious work of skilled mechanics who realized the danger of the air. I have seen mechanics rush from a hangar in a frenzy of excitement and agitation. "That machine must not go up; it has been repaired, but not inspected!" They have done their work with a will in the army; they have learned some of the dangers of flying and weak spots which must be watched. The civilian mechanic must be taught many things. First of all he must know the value of inspection. Every machine which has gone through a workshop must be inspected and checked over by a skilled mechanic before a pilot is allowed to fly it. The ideal thing would be to have legislation licensing the inspectors of aircraft and requiring that repairs on all machines be examined by a licensed inspector. The inspectors would be under civil service and would be selected by competitive examination. It may sound fantastic, but such precautions are as necessary for the preservation of life as legislation on sanitary matters. In the second place, there should be time limits placed by law covering the period of usefulness of various parts of an airplane. After fifty hours of flying there should be an inspection of certain working parts of the engine, certain wires in the body which may be strained by bad landings, and other wires in the rigging strained by flying in bad weather. New wires are always sagging and stretching a bit. Wings will "wash out," lose their usefulness by excessive flying, and must be replaced. There is a great volume of data on these matters which should be the basis for laws covering mechanical inspection of airplanes, and with which the airplane mechanic must become familiar. For the man who would like to work into the piloting of aircraft there is a very good opportunity by starting with the mechanical side. Too many pilots know next to nothing about the construction of their machines. When an engine goes bad they know that it won't run--that is all. The pilot who is a good mechanic is a gifted man in his profession. There are endless opportunities at flying-fields for mechanics who want to learn to fly. During the war it became customary to take mechanics up for flying at least once in two weeks on some fields. It gave the mechanic an interest in his work and an interest in the life of his pilot. Perhaps nothing stimulated accurate work by a mechanic more than the knowledge that at any time he might be called upon to ride in one of the planes he had helped make or repair. Some were taught flying by their officers, and later qualified as pilots. Others went through as cadets and became pilots after the regular course. The pilot of the future must learn the mechanical side, and the mechanic should be a good pilot. The two must go hand in hand to make flying a success. VI THE FIRST CROSSING OF THE ATLANTIC The story of the American triumph in being the first to fly from the New World to the Old World is a story of careful, painstaking, organized effort on the part of the American navy. With the flight of Lieut.-Commander Albert C. Read from Rockaway Naval Air Station to Plymouth, England, nearly four thousand five hundred land miles, the navy brought to fulfilment plans which had been maturing for two years. Since 1917 there have been naval flying-officers anxious to cross the ocean by air, and their plans have been cast and recast from time to time. At first there were many reasons why it was impossible to attempt such a thing while the United States was at war. Destroyers, busily hunting German submarines, could not be spared for a feat more spectacular than useful at the time. Pilots and mechanics could not be spared from the business at hand--training hundreds of seaplane pilots for service overseas. American efforts to cross the Atlantic by air date back to the spring of 1914 when the flying-boat _America_ was built to the order of Rodman Wanamaker. She was a large seaplane, a new departure in her time, and represented the combined effort of a number of the best seaplane designers in the world. Lieut. John C. Porte, of the Royal Navy, came over from England to be pilot of the boat, and after her tests in August she was to have made her flight. But Porte was recalled by his government at the outbreak of war and the project given up. In the latter half of 1918 the naval seaplane NC-1 was delivered to the Rockaway Naval Air Station--the largest seaplane ever built on this side of the water. She was originally planned, with three sister ships, as an aerial submarine-chaser. One hundred and twenty-six feet from wing-tip to wing-tip, she was equipped with three big Liberty motors--a monster seaplane, ideally suited to the purpose for which she was designed. The signing of the armistice interfered with her use as a submarine scout, and naval plans for crossing the ocean in the air were brought from their pigeonholes. The NC-1 and her sister ships under construction appeared to have been built for just such a flight. When the war ended, the navy as a whole, and the naval air service in particular, concentrated attention on the possibilities of using the NC planes for the flight. One of the first decisions made was to increase the engine power by adding a fourth engine, and to enlarge the gasolene-tanks for a long flight. Early in March of this year it became apparent that the spring or early summer would see several attempts to cross the ocean by air. On March 19th it was reported from England that the unfortunate Sopwith machine with its lucky team of Harry G. Hawker and Lieut.-Commander Mackenzie Grieve had started from England for Newfoundland. At the same time announcement was made that naval officers had been conferring over their Atlantic flight plans, and that a start would be attempted some time in May. As a matter of fact, a great deal of work had been done in secret by Commander John H. Towers, Lieut.-Commander Albert C. Read, and Lieut.-Commander Patrick N.L. Bellinger. As early as February 24th a conference was held in Washington and a date of May 15th or 16th for the flight from Newfoundland was set. This date coincided with a full moon over the North Atlantic, and the machines started May 16th from Trepassey. There were really only three routes open to pilots anxious to make the first crossing of the Atlantic. There was the flight straight from Newfoundland to Ireland, a matter of about one thousand nine hundred miles of straight flying, with the possibility of favoring winds. There was the Newfoundland-Azores route which the Americans took, and the route from Dakar, French Senegal, to Pernambuco, Brazil, which French fliers attempted. In addition there was the possibility of flight from Ireland to Newfoundland, given up by Major Woods, pilot of the Short biplane, after his forced landing in the Irish Sea. The great question of a flight straight across the Atlantic was that of fuel consumption. Could a machine be devised which would carry enough fuel to fly across one thousand nine hundred miles of water? The Sopwith Aviation Company designed their machine for such a flight, but sent it out to Newfoundland to catch and take advantage of the prevailing west winds across the North Atlantic. The story of the six weeks' wait for favorable weather, and the desperate take-off to beat the American plane, the NC-4, at the Azores, make it appear doubtful whether such winds are to be relied upon. The American planes took advantage of those winds in their flight to the Azores, that much is certain. But they were well protected with destroyers, were not pushing their planes to the limit, and did not depend upon favoring winds. That the NC-1 and the NC-3 reached the Azores, but did not make safe landings in the harbor after their long flight, is one of the fortunes of flying which must not reflect upon the American effort as a whole. The French route which Lieutenant Fontan, of the French army, tried twice, and on which he was twice forced to land because of engine trouble, was laid to take advantage of favoring winds. Across the South Atlantic the winds prevail in the spring of the year from east to west, contrary to the winds on the northern course. A twenty-mile wind at the back of a flier jumping the one thousand eight hundred miles across this bit of water would add just twenty miles an hour to the ground speed of the machine. Capt. John Alcock and Lieut. Arthur Whitten Brown startled the entire world on June 15, 1919, with the success of their straight flight from Newfoundland to Ireland, covering 1,960 land miles in 16 hours and 12 minutes, at an average speed of 120 miles an hour. Not only was this the longest non-stop flight over land or water on record, but the greatest international sporting event. As such, though credit for the first flight of the Atlantic belongs to the American NC-4, it eclipses for daring the flight of the American navy. The Vickers-Vimy plane left St. John's, Newfoundland, on June 14th, at 4.29 P.M., Greenwich mean time, and landed at Clifden, Ireland, on June 15th, at 8.40 A.M., Greenwich mean time. The machine was equipped with two 375-horse-power Rolls-Royce Eagle engines, and had a wing span of 67 feet and measured 42 feet 8 inches over all. The start of the American fliers was made after a series of tests of the seaplanes which covered a period of almost two months. At the outset it was decided to fly three out of the four NC planes, on the theory that one of the machines would probably prove to be weaker or less easy to handle than the others. The NC-2 proved to be the unfortunate sister in this case, and because of some defects in the arrangement of her engine-bearing struts she was dismantled and left behind. With the decision to start three planes simultaneously, the navy made it clear that, although it hoped all three seaplanes might complete the trip, allowance was made for one or two machines to give up the flight if they found themselves in trouble. The NC-1, and NC-3, and the NC-4 all proved to be up to expectations, and, with increased engine power, showed that they could take-off the water with a load of twenty-eight thousand five hundred pounds. After the necessary tests had been made on Jamaica Bay, Commander Towers said on May 4th that the start would be made a little after daybreak, May 6th. There remained only the task of filling their hulls with one thousand eight hundred gallons of gasolene. Early in the morning of May 5th, while mechanics were pumping gasolene into the tanks of the NC-1, a spark from an electric pump fell into a pool of gasolene and set fire to her whole right side. In a moment the heavily "doped" linen wings, with seasoned spruce spars, were a mass of hot flame. The sailors at work on the machine, with complete disregard of their personal safety, ran for fire-extinguishers, and with the fire burning around the mouth of the open tanks, confined it to the right wings of the machine and to the elevators of the NC-4 standing close by. No one believed that the NC-1 could be made ready in time for the flight twenty-four hours away. She was ready the next morning, with fresh wings from the discarded NC-2, but the flight was postponed on account of a heavy northeast wind, reported all the way to Halifax. The machines made their start from Rockaway on the morning of May 8th, at ten o'clock, and two of them, the NC-1, with Lieutenant-Commander Bellinger, and the NC-3, with Commander Towers, arrived at Halifax after nine hours' flying. The NC-4 proved to be the "lame duck" on the first leg of the flight, and came down at sea a hundred miles off Chatham, because of overheated bearings. Some alarm was felt during the night by the failure of destroyers to find her. She appeared the next morning off the Chatham breakwater, "taxi-ing" under her own power. While her sister ships, the NC-1 and the NC-3, were flying to Trepassey the NC-4 waited at Chatham. Even after the repairs were made, it seemed impossible for the NC-4 to catch up with the other two machines, and she was held stormbound for five days. On May 14th she finally got away from Chatham, and, with her new engines, made the fastest time over the short course to Halifax recorded since the beginning of the flight. Her average for the 320 miles was 85 nautical miles an hour, about 20 miles an hour faster time than either of the other two machines had made. Four days later she left Halifax for Trepassey in a last-minute effort to catch her sister planes. It seemed certain that she could not get there in time and would be forced to follow on the course a day later. Just as she flew into Trepassey Bay, on May 14th, the NC-1 and NC-3 were preparing to take-off. They postponed their start until the next day. In the mean while repairs were rushed and adjustments made, and she was ready to start the next afternoon, when all three planes started a little after six o'clock. From the beginning of the flight from Trepassey the NC-4, thought to be the "lame duck" of the squadron, ran away from the other two machines. She lost contact with them very quickly and plowed through the night alone, laying her course by the line of destroyers lying beneath her. She was about half an hour ahead of the NC-1 at daybreak the next day and within an easy run of Horta, Fayal. The half-hour lead gave the NC-4 a chance to get through a fog which was coming up over the Azores ahead of the other machines. She held a little above it until she thought she was in the right position. Then she came down through the mist. As it happened, she landed in the wrong harbor, but picked herself up and found Horta a few minutes later. She landed in Horta after fifteen hours and eighteen minutes of flying, in which she averaged 78.4 nautical miles an hour for the flight. The machine was nearly five hours ahead of the schedule laid down by the Navy Department. Both the other planes were forced to land at sea, the NC-3 after 1,250 miles of flight--the longest ever made over water up to that time--and the NC-1 after more than 1,100 miles in the air. The NC-1 with Bellinger and his crew was picked up on the morning of Saturday, May 17th, by a Greek steamer, the _Ionia_, and brought into Horta. Towers with the NC-3 tossed about for nearly sixty hours at sea and was not picked up until the following Monday, when the public had begun to fear for his safety. On Tuesday, May 20th, the NC-4 hopped off for the shortest leg of the flight, 150 miles from Horta to Ponta Delgada, where the fuel and supplies for the machines were. With favoring winds at her back, and with the lightest load she had carried, she covered the distance in one hour and forty-four minutes, an average speed of 86.7 nautical miles an hour, or more than 99 land miles. This was a new record for the seaplanes on the ocean flight. Meanwhile Harry G. Hawker and Lieut.-Commander Mackenzie Grieve, the Sopwith team waiting so long at St. John's for a chance to fly, stimulated in their daring attempt by reports of American successes at the Azores, took-off on their flight straight across on the afternoon of Sunday, May 18th. All through that night he flew, when his engine began to give signs of overheating, due to a clogged water-filter. Early the next morning, about half-way across, Hawker decided that there was no chance to make the land, and began looking through the fog for a chance for a safe landing. By zigzagging on the steamship courses for about two hours, with his engine hot but running well, he picked up the Danish steamer _Mary_, and pancaked on the water about two miles ahead of her. Because the little tramp steamer had no wireless, the world was kept waiting a week, before word was signaled to land that Hawker and Grieve were safe. With the Sopwith team out of the race, it became evident that Commander Read and the NC-4 would actually win the honors for the first flight. On the morning of May 27th he started over his well-patrolled course of eight hundred miles, and, after a little less than ten hours of flight, brought his machine into the harbor before Lisbon, Portugal. Americans had crossed the ocean in the air, and the enthusiastic Portuguese capital turned out to do them every honor. Read, however, rather than linger, pushed on again May 30th, in the midst of the celebration for his triumph on the last leg of his course to Plymouth, seven hundred and seventy-five nautical miles. Engine trouble, the first since the machine had left Chatham, developed, and at the end of two hours he was forced to land at the mouth of the Mondego River, about a hundred miles on his way. The trouble was a water leak. It was quickly repaired, and he started again, but decided to put up at Ferrol, Spain, two hundred miles farther on the course, for the night. Early in the morning of May 31st Commander Read started from Ferrol for Plymouth, and at the end of seven hours and six minutes of flight came down in the harbor, where a warm reception was waiting for him. The actual flying time since leaving the Rockaway Naval Air Station was fifty-seven hours and sixteen minutes, and the average rate of flight was at a speed of sixty-eight nautical miles an hour. VII LANDING-FIELDS--THE IMMEDIATE NEED The immediate need, to establish aviation throughout the entire country, is a series of landing-fields from the Atlantic to the Pacific coast. These landing-fields should not be designed primarily for transcontinental flying-stations, but for city-to-city flying. There is going to be a great amount of aerial traffic from New York to San Francisco, to be sure, but the future of flying is in the linking up of cities a few hundred miles apart. The War Department has already taken steps, and will establish thirty-two fields in the country to encourage flying. Many more are needed. Atlantic City is apparently the pioneer air port of the country, and for many reasons this is natural. There are political and social advantages which make Atlantic City ideal. Rules have been laid down for the coming and going of airships, and a field for land machines and water space for seaplanes have been laid out. A large aeronautical convention has already been held there. Every city in the United States will have a landing-field and hangars for airplanes, as well as mechanics to care for them. Whether this is to be a private or public enterprise lies in the hands of the people handling such things. Much could be said for either type of establishment. The thing must come; it is as logical as one, two, three. There are some, perhaps, who remember the roars of derision which went up when the first automobile garage was established in their town. Such a thing was visionary-there would never be enough machines to make it pay! There are many reasons why it is impossible to consider the use of city roofs, for the present, as suitable landing-places for airplanes. In fact, the first successful landing on a roof made by Jules Vedrines last January was hailed as a feat of almost unparalleled daring. He flew and landed on the roof of the Galeries Lafayette in Paris, and won a prize of $5,000 for doing it. The police of Paris refused to allow him to fly off the roof, and he was compelled to take his machine apart and lower it in an elevator. The theory of flight, the laws which make it possible apparently to defy all laws of gravitation, make it impossible for us to depend on the roofs of buildings in large cities and landing-places. It will be a long time before the dreams of men who would establish landing-places on hotel roofs can come true. The progress of aeronautical development has been great enough so that there is no need to overemphasize it--to set ridiculous tasks which cannot be accomplished. We shall not see the business man flying to his office in the city from his country estate--unless some landing-field is built on the lower end of Manhattan Island as has been proposed. The Chamber of Commerce of the State of New York has taken up the matter of legislation to make landing-fields possible, and it must go through. The business man ought, in the near future, to be able to use the airplane for quick trips to Albany. It would save hours over rail time, and here the airplane has a wonderful field of usefulness. Airplanes have made the trip from Washington to New York in very quick time, only to have to go on to Mineola to land on the airdrome there. It takes nearly an hour to come in from Mineola, but even at that the saving of time is still considerable. The speed and efficiency of airplane travel to and from New York and other cities is materially affected by the lack of landing-fields close to the business section of the city. There must be a large field, broad in every dimension, to permit the landing and taking-off of airplanes. A machine must get up flying speed running across the ground before it gets into the air. The flying speed varies with the type of machine, and it may be estimated that most machines take-off and land at a speed of from forty-five to sixty miles an hour. The air must be passing through their planes at this speed before they will begin to fly, and it takes a little run to get up flying speed. Similarly, when an airplane lands, it must lose its flying speed gradually. It may glide to within a few feet of the ground, and then "flatten out" just off the ground and run along until it loses its speed, the air no longer passes over its planes fast enough to support it, and it drops to the ground. Such are the limitations which the necessity for speed in airplane flight imposes. Compare the paper dart flying through the air. As long as it moves quickly it will fly. Or a kite, that will fly when the wind is strong enough. The airplane creates its own wind to support itself. There are four forces acting on an airplane in flight, and they must be properly overcome and balanced. There is lift, the upward force exerted on the planes by the passage of air over their surfaces; and drift, the resistance to the passing of an airplane, the retarding force acting opposite to the direction of motion. Then thrust, the forward effort of a machine exerted by a propeller pushing or pulling. And finally gravity. The primary conditions of flight are that lift made by the planes shall be equal to the force of gravity, and that the forward thrust must be equal to the drift. At that point a machine will sustain flight--a fairly simple thing on paper. But the times that machines have stalled in the air, with their motors full on because their pilots have failed to sustain flight, have let the force of gravity overcome lift, are too numerous to mention. That dart, if pointed at a proper angle and let loose, will fly; its lift will overcome the force of gravity, even though it has no motive power of its own. An airplane without an engine could be pushed off the Palisades at flying speed, and a skilful pilot could bring it to a reasonably safe landing at the foot. Flight does depend on motion, but motion does not depend on motive power. Given a sufficiently high altitude, the mere act of dropping through the air creates motion, and this motion will sustain flight. An airplane is in no particular danger in the air if the motor stops--provided it is in an open stretch of country with plenty of fields. Instinctively the pilot will nose down and glide, and on that glide he will find himself maintaining flying speed. He can turn and maneuver his machine, and pick out almost any field near at hand. The only limitations are that he cannot glide more than five times his height, and when he comes down to the ground he must stop gliding and land. He must land on anything that presents itself, a field if he has good judgment; if not, then a barn or swamp or woods. He must land when the end of his glide brings him to the ground. This is commonly termed a "forced landing," and in every sense of the word it is one. There is no pilot of any extensive flying experience who has not had to make a forced landing. Ninety out of a hundred are perfectly orderly safe landings; the odd ones are occasionally crashes. Incidentally it may be said that forced-landing practice by flying pupils is the most beneficial which may be imagined. It teaches control over a machine as nothing else will. It may be carried out from any height, shutting off the motor, picking out a field, gliding for it, turning and twisting to get into proper position as regards the wind, and "giving her the gun" just at the fence and flying on. A forced landing over the country is safe, but over a city it is the most deadly thing imaginable. For a machine caught with a "dud" engine over New York there is no escape but a terrific crash in the city streets, against the side of some building, with danger to the pilot and the people in the street below. There has been no motor made by the hand of man which would not let a pilot down at some unexpected time. The instance of Major Woods, starting on his flight across the Atlantic, and forced to come down to the Irish Sea is one example. The NC-4, American naval seaplane, had a forced landing at sea, a hundred miles from Chatham, Massachusetts, on the first leg of the Atlantic flight from this side. Its engines had been carefully cleaned and tested, and yet they failed. Harry G. Hawker's engine failed him half-way from Newfoundland to Ireland and let him down into the sea, from which he was picked up by the greatest good luck. That is one of the most exasperating and human things about a gasolene-engine. It is efficient, but not thoroughly dependable. The best of them are liable to break down at the most needed moment, due to a hundred causes outside of the control of a mechanic or pilot. Care and rigid inspection will reduce the possibilities, but engine failure cannot yet be eliminated. That is one of the principal reasons why the roofs of buildings around big cities are so dangerous. The sides of a building drop away from the roof. An error in judgment and the machine is over the edge. It is even more dangerous to take-off. An airplane motor is ten times as likely to develop a weakness while it is cold. A motor starting a flight is never well warmed up, and fifty feet from the edge of the roof it may give out, with awful consequences. As a practicable thing, roofs are at present impossible. There is not a flying-officer in the world who will not agree. An interesting series of experiments has been carried out in England on what has been known as the helicopter machine. This machine is not dependent upon speed to fly, but merely on engine power applied through a propeller of great pitch. The idea is not new, but is along the lines specified by Orville Wright when he said that a kitchen table could fly if it had a good enough engine. The effort is being made to make a machine which can hover, can hold itself in the air by brute force of its propeller blades beating the air. The thing sounds impossible to adapt, say some aeronautical engineers. Those who have seen the experiments, however, express great optimism. A machine of this sort would land and take-off in a very small space, and might be adapted to use around cities. It might even make flying over cities safe but for the human equation of the engine again. This machine is dependent on engine power. Apparently there would be two engines, or two driving mechanisms, one operating the lifting propeller and the other the pulling propeller. For the present the great need is for landing-fields as near the heart of most American cities as possible. There should be quick transportation to the business section provided, as well as hangars and mechanics. When that is done we may very well say that aerial transportation for passengers and freight is an accomplished fact. VIII THE AIRPLANE'S BROTHER At the end of 108 hours and 12 minutes of sustained flight, more than four days, the British dirigible R-34 swung into Roosevelt Field, came to anchor, and finished the first flight of the Atlantic by a lighter-than-air airship. To the wondering throngs which went down Long Island to see her huge gray bulk swinging lazily in the wind, with men clinging in bunches, like centipedes, to her anchor ropes, and her red, white, and blue-tipped rudder turning idly, she was more than a great big balloon, but a forerunner of times to come. She had come to us, a pioneer over the sea lanes which are to be thronged with the swift dirigibles of the future plying their easy way from America to Europe. The performance of the R-34, undertaken in the line of duty, has eclipsed all the previous records made by dirigibles and is, in fact, a promise of bigger things to come. There was that Zeppelin, which cruised for four days and nights down into German East Africa and out again, carrying twenty-five tons of ammunition and medicine for the Germans who were surrounded and obliged to surrender before help arrived. The R-34 started from East Fortune, Scotland, on Wednesday, July 2, 1919, at 2.48 o'clock in the morning, British summer time, and arrived, after an adventurous voyage, at Mineola, Sunday, July 6, at 9.54 A.M., American summer time. She had clear sailing until she hit the lower part of Nova Scotia on Saturday. Electrical storms, which the dirigible rode out, and also heavy head winds, kept her from making any progress, and used up the gasolene. About noon of Saturday the gasolene situation became acute, and Major G.H. Scott, her commander, sent a wireless message to the United States Navy Department at Washington, asking for destroyers to stand by in the Bay of Fundy in case the gasolene should run short and the airship get out of control. Destroyers were immediately despatched, but in the next few hours the weather improved, and the ship was able to continue on her journey. It was feared, however, she might run out of fuel before reaching Long Island, and mechanics were sent to Chatham and to Boston to pick her up in case of trouble. The big ship surprised everybody by appearing over Long Island about nine o'clock Sunday morning. The officer in charge of the landing party having gone to Boston, expecting her arrival there, Major John Pritchard "stepped down" in a parachute from the airship, and, landing lightly, took charge of the landing of the big machine. An approaching cyclone, which would have made it almost impossible to handle the airship at Mineola, was responsible for a rather hurried start back at midnight of Wednesday, July 9th. She visited Broadway in the midst of the midnight glare, turned over Forty-second Street a little after one o'clock in the morning, and put out to sea and her home airdrome. The voyage back was mostly with favoring winds, and she landed at Pulham, the airship station in Norfolk, after 75 hours and 3 minutes of flight. The voyage back was practically without incident except for the failure of one engine, which in no way held back the airship. She was turned off her course to East Fortune by reports that there were storms and head winds which might hold her back in case she kept on her way. The voyage was probably the most significant in the history of flying. It brought home to the public the possibilities of the airship for ocean commerce as nothing else could have done. The ship remained in the air longer than any previous airship, and pointed the way clear to commercial flying. It is, in fact, only considered a matter of time before companies are started to carry passengers and mails across the Atlantic at a price that would offer serious competition to the fastest steamships. The airship has been very much neglected by popular favor. Its physical clumsiness, its lack of sporting competition in comparison with the airplane which must fight to keep itself up in the air, its lack of romance as contrasted with that of the airplane in war, have all tended to cast somewhat of a shadow over the lighter-than-air vessel and cause the public to pass it by without interest. It is a very real fact, therefore, that very few people realize either the services of the airship in the war or its possibilities for the future. During the war the airship was invaluable in the ceaseless vigil for the submarine. England early stretched a cordon of airship guards all about her coasts and crippled the U-boats' work thereby. The airship had a greater range of vision and a better downward view than any sea-vessel; it could travel more slowly, watch more closely, stay out much longer, than any other vessel of the air. The British credit their airships with several successful attacks on submarines, but they give them a far greater place in causing a fear among the under-sea boats which drove them beneath the surface and greatly limited their efficiency. The German Zeppelins, on the other hand, stand out in public imagination as a failure in the war, especially because the British shortly established an airplane barrage which proved to be their masters. This view is correct only in so far as it applies to interior raiding, for which, indeed, the Zeppelin was not designed. How untrue it is of the Zeppelin as the outpost for the German fleet British officers will readily admit. Indeed, they credit them with the escape of the German fleet at Jutland, one of the deepest regrets in British naval history. As eyes for the German fleet in the North Sea, the Zeppelins, with their great cruising range and power of endurance, proved almost invaluable. Airships have, then, behind them a rich heritage and before them a bright future. Much work that the airplane can do they cannot do; while, on the other hand, much work that they can do the airplane cannot. The two services are essentially different and yet essentially complementary. Between them they offer nearly every facility and method of travel in the air which could be desired. Each must be equally developed in order to increase the efficiency and the value of the other. The great difference, of course, between the airplane and the airship is that the former sustains itself as a heavier-than-air vessel by the lifting power of the air in relation to a body driven hard against it by its powerful engines, while the latter sustains itself as a lighter-than-air body because of the large amount of air displaced by a huge envelop loaded with gas much lighter than the air itself. The contrast is obvious; one vessel is small, agile, and very fast; the other is slow and clumsy. The airship cannot attain anything like the speed of the airplane, nor can it go so high or maneuver so quickly, but on the other hand, at least for the immediate present, it can stay afloat very much longer and carry much greater weight. Moreover, the airship has certain other easily perceptible advantages over the airplane. Ordinarily an airship need not fly at much more than a thousand feet, which not only makes far less cold traveling than at higher altitudes, but also allows the passengers to enjoy the view far better than from an airplane, whence the world below looks like a dull contour map. An airship also flies on an even keel; it does not bank as an airplane does nor does it climb or descend so quickly. At present airship travel gives a greater feeling of comfort and security. Sleeping is a calm experience; moving about comparatively simple. Also there is less noise than in an airplane where the engines beat incessantly and the wind rushes through the wires and struts. An airship has no wires and can at the same time slow down and even shut off its engine, so that it need be no more noisy than a motor-car. Engine failure also is not so serious as in an airplane, for the gas-bag will always keep the ship up until there has been a chance for repairs. Up to the present, too, the airship is less of a fair-weather flier than the airplane. A surprising record has been attained in the war by British airships, as is shown by the fact that in 1918, a year of execrable weather, there where only nine days during which their vessels were not up. This is, of course, in considerable contrast to airplanes as at present developed, but it may reasonably be expected that the latter will very soon develop to the same point of independence of the weather. Of course, the great difficulty of airships has been their ungainly size and the difficulty of housing them. The sheds, particularly those for the Zeppelins, have been most costly, but the British have recently developed a system of mooring masts which make much of this expense unnecessary. If such a device can be successfully put into every-day use it will enormously increase the ease of loading and unloading passengers, which now makes for considerable discomfort and loss of time. Some of the plans for future airships are unbelievable to one who has not followed their development carefully. Already there is planned in England a monster ship known as the "ten million," for the reason that it will have a gas capacity of ten million cubic feet, over four times that of the largest Zeppelin. The length is placed at 1,100 feet, the speed at 95 miles an hour, the cruising range 20,000 miles, and the cost at about $1,000,000. As a matter of actual practice, however, the best division of the space and lifting power of this airship would be for it to carry a crew of about 20, a useful load of 200 passengers or 150 tons of merchandise, and 50 tons of petrol, which would give it a non-stop run of about 5,000 miles. Airship travel would undoubtedly be expensive. The gas alone to maintain such a vessel as described is expected to cost about $30 an hour, which, added to the original investment for the ship and its house and the wages of the crew and the 200 or more skilled men at each station, would come up to a high figure. At the same time, the airship would not afford the element of very high speed which is so certain to justify any expense which may have to be put into the airplane. Nevertheless, with the improvements that are sure to come, with the ability to reach places not touched by other methods of travel, the freedom from all the delays, inconveniences, and expense of trans-shipment, this preliminary charge will be largely compensated for. Those who sponsor the airship urge that it will be used almost exclusively for long-distance flights beyond the range of the ordinary airplane and very little for short local flights. For transatlantic travel, for instance, it is being particularly pressed, as ships even of to-day have all the capacity for such a voyage, without the dangers which might surround an airplane if its sustaining engine power were to give out. There are several records which would easily justify it. Besides the flight across the Atlantic by the R-34 and the four-day trip of the German airship from Bulgaria to Africa and back, a British airship during the war stayed up for 50 hours and 55 minutes, and another, just after the armistice, stayed up for 61 hours. An American naval dirigible a short time after the armistice made a flight from New York to Key West, 1,200 miles, at 40 miles an hour, for 29-1/2 hours, with one stop at Hampton Roads. As an example of some of the difficulties of airship travel, this landing was possible only after the ship had circled the town and dropped a message asking the people to go to a large field near by and catch the dirigible drag-net when it approached the ground. Even at that, however, the time of less than a day and a quarter for what is usually a very arduous train trip from New York down the coast to Florida gives some indication of the possibilities of this method of travel when properly developed. Practically all the new airships contemplated look to a much greater speed than the pre-war speed of about 40 miles an hour. It is not at all uncertain that they will not run up as high as 100 miles, though at the present time that figure is extreme. But granted that they no more than double the pre-war speed and reach the actual figure contemplated of about 75 miles an hour, they still would triple the best passenger-steamer speed, which would make them a matter of the utmost importance in all long ocean voyages. Just how the balance will be struck between airplanes and airships is a big question. It is interesting to note, however, that the supporters of the airship have worked out a general theory that the lighter-than-air vessel with its already demonstrated cruising and weight-carrying capacity will be used for all long routes, and for that almost exclusively, while the heavier-than-air vessel, with its great speed and facility for maneuvering, will be used for local flights. This, in their viewpoint, would mean that the world would be girded by great lanes of airships, fed from a few main centers by swift-scurrying airplanes radiating in from every direction. IX THE CALL OF THE SKIES The day of the air has undoubtedly come. The old order of the world has been entirely changed. A new life is breaking in over the near horizon. Almost in a moment the span of the world has shrunk to a quarter of its former size, so that where before we thought in terms of countries very soon we must think in terms of continents. The world is shortly to be linked up as it never has been before, till the great continents are brought as near as were the near-by nations of the past years. Any one who doubts the future of aviation should realize the helplessness of the science after the armistice because of the complete lack of international laws to make possible its application in Europe, where it was most highly developed. With men and machines ready, they had to hold to the ground largely because there was in force no treaties assuring them the right to cross frontiers. The broad plans for international routes were held up because aviation itself was so big in its expanse that it could not meet its just fulfilment within national lines. As a result a new law must be written. The law of the air will be one of the most intricate and the most fascinating in the world. It presents problems never before presented and covers a scope paralleled only by the laws of the sea. Very fortunately, however, aerial international law may be written at the very start of the science by a common international standard and practice, thus obviating the greatest part of the divergences which long years of habit have grafted into the maritime laws of the various nations. The slate is clean so that uniformity may be assured in a law which is soon to come into the most vital touch with the daily lives of the nations. Who, for instance, owns the air above the various nations? Obviously the individual landowner has rights, especially as to freedom from damage. The nation also has rights, especially for its protection and for police work. How high, however, does this jurisdiction go? Some assert that a maximum altitude should be set, say five thousand feet, above which the air would be as free as the seas; others that each nation must have unqualified control to the limit of the ether. Then comes the question of passports, customs, registration, safety precautions, and damages. As already shown, the man on the ground is helpless against the airplane which chooses to defy him. People and goods can cross national lines by the air without passports or customs. There will be no main ports of entry as in sea or train commerce, and it is too much to think that any nation can patrol its whole aerial frontier in all its various air strata. Undesirable immigrants or small precious freight can be smuggled in with the greatest ease through the route of the air. Obviously the most elaborate international rules are necessary. Planes must have some method of international registration and license, just as in a more limited sense ships on the seas have what amounts to an international status. Landing-fields must be established and open to foreign planes, each nation providing some kind of reciprocal landing rights to other nations. Arrangements must be made so that if a monkey-wrench drops out of a plane a mile or two up in the air proper damages can be collected. For such things there is to-day but little precedent in law. This but sketches the problems. It shows, however, how closely this new science will bind the world together and obliterate national lines and nationalistic feelings. As the sea has been the great civilizer of the past, so the air will be the great civilizer of the future. Through it men will be brought most intimately in touch with one another and forced to learn to live together as they have not been forced to live together before. The artificial barriers that have stood so firm between nations in the past are now swept away and a great common medium of intercommunication opened. Let it not be understood that all this will take place overnight. Far from it, for the experience of the war has taught only too well that the organization of an air force takes time and patience. Up to date the essential fact is that the science, the value, and the possibilities of flight have been proved in a thousand different ways. Vistas of travel and experience have been opened up which but a few months ago would have seemed fanciful. Everywhere men are dreaming dreams of the future which challenge one's deepest imagination. Already Caproni, the great Italian inventor, has signed a contract to carry mails from Genoa to Rio Janeiro. Now comes news of an airplane with room for ninety-two passengers. Engine power and wing space have gone on increasing in a dazzling way till one is almost afraid to guess what the future may hold. But, omitting all prophecy, the actual accomplishments to date are so stupendous that there is no need to speculate as to the future. If all technical development were to stop just where it stands, the factories and workshops of the world could well be occupied for years in turning out the machines necessary for the work awaiting them. Scientific development has gone so infinitely far ahead of actual production that as yet aviation is not being put to a fraction of its use. Even more serious, however, is the general public failure to realize the gift which is within their reach. Flying was first a circus stunt and later a war wonder. The solid practical accomplishments have been lost sight of in the weird or the spectacular. People who marveled when a British plane climbed up nearly six miles into the air, or 30,000 feet, where its engine refused to run and its observer fainted, failed generally to analyze what the invasion of this new element would mean in the future of mankind. What is now needed is a big, broad imagination to seize hold of this new thing and galvanize it into actual every-day use. There are many skeptics, of course, many who point out, for instance, that the element of cost is prohibitive. This is both fallacious in reasoning and untrue in fact. A modern two-seated airplane, even to-day, costs not over $5,000, or about the price of a good automobile. Very soon, with manufacturing costs standardized and the elements of newness worn off, this price will fall as sharply as it has already fallen during the war. But what, after all, is cost in comparison with time? Modern civilization will pay dearly for any invention which will increase ever so little its hours of effectiveness. The great German liners before the war lavished money without stint to save a day or two in crossing the Atlantic. The limited express trains between New York, Boston, Washington, and Chicago have for years made money by carrying busy men a few hours more quickly to their destination. What will not be paid if these times of travel can be reduced practically to half? The element of danger has been reduced to a minimum and will be still more reduced as emphasis is laid on safety rather than wartime agility. Many men, of course, will meet their death in the air, just as in the early days many men met their death in ships and in railroad trains, but this will not be a deterrent if the goal is worth attaining. There will be accidents in learning to fly, there will be accidents of foolhardiness and of collision or in landing, but they will decrease to the vanishing-point as experience grows. Already the air routes which have been established have a high record of success and freedom from fatalities. The great need of aviation to-day is faith--faith among the people, among the manufacturers, among the men who will give it its being. Its success is as inevitable as that day follows night, but the question of when that success is attained, now or generations from now, is dependent on the vision which men put into it. If they are apathetic and unreasonable, if they chafe at details or expect too much, it will be held back. If, on the other hand, they go to meet it with confidence, with coolness, and with a realization both of its difficulties and its potentialities, its success will be immediate. The task is one of the greatest, the most vital, and the most promising which mankind has ever faced. With the general theories proved and demonstrated, the great crisis of invention has passed, and the slow, unspectacular process of development and application has set in. Now has come the time for serious, sober thought, for careful, analytical planning, for vision combined with hopefulness. It is well in these early days, when flight is with the general public a very special and occasional event, to remember what has happened since Watt developed the steam-engine only a few generations ago, when Columbus set the first ship westward, or when America's first train ran over its rough tracks near the Quincy quarries. The development of aviation will be world-wide and will include all sorts and races of men. The nations all start pretty much abreast. Those which developed war air services have an advantage in material and experience, but this is a matter only for the moment. The main lines of progress are now pretty widely known and the field is wide open to those who have the imagination to enter it. There is practically no handicap at this early stage which cannot be overcome with ease. There is, of course, an element of individual gamble to those who enter this competition. Undoubtedly there will be many failures, as in all new fields; failures come to those who put in capital as well as those who contribute their scientific knowledge. But by the same token there will be great successes both financially and scientifically. The prize that is being striven for is one of the richest that have ever been offered and the rewards will be in accordance. This has been the case at the birth of every great development in human progress and will undoubtedly be the case with the science of flight. Until a field becomes standardized it offers extremes on both sides rather than a dull, dreary, but safe average. As aviation runs into every phase of activity it will require every kind of man--manufacturer, scientist, mechanic, and flier. It offers problems more interesting and more complex than almost any others in the world. The field is new and virgin, the demand world-wide, and the rewards great. For the flier there is all the joy of life in the air, above the chains of the earth, reaching out to new, unvisited regions, free to come and go for almost any distance at any level desired, a freedom unparalleled. For the manufacturer there is all the lure of a new product destined in a short time to be used as freely as the automobile of to-day; for the scientist there are problems of balance, meteorology, air pressure, engine power, wing spread, altitude effects, and the like in a bewildering variety; for the explorer, the geographer, the map-maker a wholly new field is laid open. The best men of every type are needed to give aviation its full fruition. In Europe this is realized to a supreme degree. England especially, and also France and Italy, have put their best genius at work to fulfil the conquest of the air. Their progress is astonishing and should be a challenge to the New World. After the natural hiatus which followed the armistice the leading men have set to work with redoubled vigor to take first place in the air. In twenty years' time our life of to-day will seem centuries old, just as to-day it is hard to realize that the automobile and motor-truck do not date back much over a generation. No change that has ever come in man's history will be so great as the change which takes him up off the ground and into the air. This swift and dazzling era that is so close upon us is hardly suspected by the great mass of people. The world will be both new and better for it. Less than the train or the motor-car will the airplane disturb its features. On the blue above white wings will glitter for a moment, a murmuring as of bees will be heard, and the traveler will be gone, the world unstained and pure. Meanwhile high in the clouds, perhaps lost to view of the earth, men will be speeding on at an unparalleled rate, guiding their course by the wireless which alone gives them connection with the world below. Has there ever in all history been an appeal such as this? ADDENDUM A PAGE IN THE DICTIONARY FOR AVIATORS What is to become of all the new words, some of them with new meanings, the old words with new meanings, and the new words with old meanings, coined by the aviators of the American and British flying services in the war? Are they to die an early death from lack of nourishment and lack of use, or will they go forward, full-throated into the dictionary, where they may belong? Here are just a few of them, making a blushing début, so that it may be seen at once just how bad they are: AEROBATICS--A newly coined word to describe aerial "stunting," which includes all forms of the sport of looping, spinning, and rolling. The term originated in the training schedule for pilots, and all pilots must take a course in aerobatics before being fully qualified. AEROFOIL--Any plane surface of an airplane designed to obtain reaction on its surfaces from the air through which it moves. This includes all wing surface and most of the tail-plane surface. AILERON--This is a movable plane, attached to the outer extremities of an airplane wing. The wing may be either raised or lowered by moving the ailerons. Raising the right wing, by depressing the right aileron, correspondingly lowers the left wing by raising the left aileron. They exercise lateral control of a machine. BLIMP--A non-rigid dirigible balloon. The dirigible holds its shape due to the fact that its gas is pumped into the envelop to a pressure greater than the atmosphere. It can move through the air at forty miles an hour, but high speed will cause it to buckle in the nose. BUMP--A rising or falling column of air which may be met while flying. A machine will be bumped up or bumped down on a bumpy day. A hot day over flat country, at noon, will generally be exceedingly bumpy. CRASH--Any airplane accident. It may be a complete wreck or the plane may only be slightly injured by a careless landing. Crashes are often classified by the extent of damage. A class A crash, for instance, is a complete washout. A class D crash is an undercarriage and propeller broken. DOPE--A varnish-like liquid applied to the linen or cotton wing fabrics. It is made chiefly of acetone, and shrinks the fabric around the wooden wing structure until it becomes as tight as a drum. The highly polished surface lessens friction of the plane through the air. DRIFT--Head resistance encountered by the machine moving through the air. This must be overcome by the power of the engine. The term is also used in aerial navigation in its ordinary sense, and a machine flying a long stretch over water may drift off the course, due to winds of which the pilot has no knowledge. DUD--A condition of being without life or energy. An engine may be dud; a day may be dud for flying. A shell which will not explode is a dud. A pilot may be a dud, without skill. It is almost a synonym for washout. FLATTEN Out--To come out of a gliding angle into a horizontal glide a few feet from the ground before making a landing. The machine loses flying speed on a flat glide, and settles to the ground. FLYING SPEED--Speed of a plane fast enough to create lift with its wing surfaces. This varies with the type of plane from forty-five miles an hour as a minimum to the faster scout machines which require seventy miles an hour to carry them through the air. When a machine loses flying speed, due to stalling, it is in a dangerous situation, and flying speed must be recovered by gliding, or the machine will fall into a spin and crash out of control. FORCED LANDING--Any landing for reasons beyond the control of a pilot is known as a forced landing. Engine failure is chiefly responsible. Once the machine loses its power it must go into a glide to maintain its stability, and at the end of the glide it must land on water, trees, fields, or roofs of houses in towns. FUSELAGE--This word, meaning the body of a machine, came over from the French. The cockpits, controls, and gasolene-tanks are usually carried in the fuselage. HOP--Any flight in an airplane or seaplane is a hop. A hop may last five minutes or fifteen hours. JOY-STICK--The control-stick of an airplane was invented by a man named Joyce, and for a while it was spoken of as the Joyce-stick, later being shortened to the present form. It operates the ailerons and elevators. LANDFALL--A sight of land by a seaplane or dirigible which has been flying over an ocean course. An aviator who has been regulating his flight by instruments will check up his navigation on the first landfall. PANCAKE--An extremely slow landing is known as a pancake landing. The machine almost comes to a stop about ten feet off the ground, and with the loss of her speed drops flat. There is little forward motion, and this kind of landing is used in coming down in plowed fields or standing grain. Jules Vedrines made his landing on the roof of the Galeries Lafayette in Paris by "pancaking." SIDE-SLIP--The side movement of a plane as it goes forward. On an improperly made turn a machine may side-slip out--that is, in the direction of its previous motion, like skidding. It may side-slip in, toward the center of the turn, due to the fact that it is turned too steeply for the degree of the turn. Side-slipping on a straight glide is a convenient method of losing height before a landing. STALL--A machine which has lost its flying speed has stalled. This does not mean that its engine has stopped, but in the flying sense of the word means that friction of the wing surfaces has overcome the power of the engine to drive the machine through the air. The only way out of a stall is to regain speed by nosing down. A machine which has lost its engine power will not stall if put into a glide, and it may be brought to a safe landing with care. STRUT--The upright braces between the upper and lower wings of a machine are called struts. They take the compression of the truss frame of the biplane or triplane. Each wing is divided into truss sections with struts. S-TURN--A gliding turn, made without the use of engine power. A machine forced to seek a landing will do a number of S-turns to maneuver itself into a good field. TAIL SPIN--This is the most dreaded of all airplane accidents, and the most likely to be fatal. A machine out of control, due often to stalling and falling through the air, spins slowly as it drops nose first toward the ground. This is caused by the locking of the rudder and elevator into a spin-pocket on the tail, which is off center, and which receives the rush of air. The air passing through it gives it a twisting motion, and the machine makes about one complete turn in two or three hundred feet of fall, depending upon how tight the spin maybe. The British speak of the spin as the spinning nose dive. TAKE-OFF--This is the start of the machine in its flight. After a short run over the ground the speed of the machine will create enough lift so that the plane leaves the ground. TAXI--To move an airplane or seaplane on land or water under its own power when picking out a starting-place, or coming in after a landing. This is not to be confused with the run for a start when the plane is getting up speed to fly, using all her power. The NC-4 "taxied" a hundred miles to Chatham after a forced landing, and the NC-3 came in two hundred and five miles to Ponta Delgada after she landed at sea. VERTICAL BANK--In this position the machine is making a turn with one wing pointing directly to the ground, and its lateral axis has become vertical. The machine turns very quickly in a short space of air, and the maneuver is sometimes spoken of as a splitting vertical bank. In a vertical bank the elevators of a machine act as the rudder and the rudder as an elevator. The controls are reversed. WASHOUT--Means anything which _was_ but is not now--anything useless, anything that has lost its usefulness, anything that never was useful. Flying may be washed out; that is, stopped; a day may be a washout, a vacation; a machine may be a washout, wrecked beyond repair; a pilot may be a washout, useless as a pilot. It has a variety of meanings, and each one is obvious in its connection. The term became familiar to American fliers with the Royal Air Force. ZOOM--To gain supernormal flying speed and then pull the machine up into the air at high speed. The rush of wind will zo-o-om in the ears of the pilot. It is a sport in the country to zoom on farmers, on houses and barns, nosing directly for the object on the ground and pulling up just in time to clear it with the undercarriage. THE END 
27557	----	images generously made available by The Internet Archive/American Libraries.) LEARNING TO FLY [Illustration: _Photo by Topical Press Agency._ A SCHOOL MACHINE WELL ALOFT.] LEARNING TO FLY A PRACTICAL MANUAL FOR BEGINNERS BY CLAUDE GRAHAME-WHITE AND HARRY HARPER _FULLY ILLUSTRATED_ NEW YORK THE MACMILLAN COMPANY PRINTED IN ENGLAND. CONTENTS I. THEORIES OF TUITION 9 II. TEMPERAMENT AND THE AIRMAN 20 III. FIRST EXPERIENCES WITH AN AEROPLANE 24 (AS DESCRIBED BY MR. GRAHAME-WHITE) IV. THE CONTROLLING OF LATEST-TYPE CRAFT 31 V. THE STAGES OF TUITION 38 VI. THE TEST FLIGHTS 53 VII. PERILS OF THE AIR 56 VIII. FACTORS THAT MAKE FOR SAFETY 76 IX. A STUDY OF THE METHODS OF GREAT PILOTS 82 X. CROSS-COUNTRY FLYING 92 XI. AVIATION AS A PROFESSION 99 XII. THE FUTURE OF FLIGHT 104 ILLUSTRATIONS A SCHOOL MACHINE WELL ALOFT _Frontispiece_ FACE PAGE GRAHAME-WHITE SCHOOL BIPLANE 34 THE CONTROLS OF A SCHOOL BIPLANE 36 REAR VIEW OF A SCHOOL BIPLANE 38 POWER-PLANT OF A SCHOOL BIPLANE 40 MOTOR AND OTHER GEAR--ANOTHER VIEW 42 PUPIL AND INSTRUCTOR READY FOR A FLIGHT 44 PUPIL AND INSTRUCTOR IN FLIGHT (1) 46 PUPIL AND INSTRUCTOR IN FLIGHT (2) 48 PUPIL AND INSTRUCTOR IN FLIGHT (3) 50 Authors' Note.--The photographs to illustrate this book, as set forth above, were taken at the Grahame-White Flying School, the London Aerodrome, Hendon, by operators of the Topical Press Agency, 10 and 11, Red Lion Court, Fleet Street, London, E.C. AUTHORS' NOTE This book is written for the novice--and for the novice who is completely a novice. We have assumed, in writing it, that it will come into the hands of men who, having determined to enter this great and growing industry of aviation, and having decided wisely to learn to fly as their preliminary step, feel they would like to gain beforehand--before, that is to say, they take the plunge of selecting and joining a flying school--all that can be imparted non-technically, and in such a brief manual as this, not only as to the stages of tuition and the tests to be undergone, but also in regard to such general questions as, having once turned their thoughts towards flying, they take a sudden and a very active interest. It has been our aim, bearing in mind this first and somewhat restless interest, to cover a wide rather than a restricted field; and this being so, and remembering also the limitations of space, we cannot pretend--and do not for a moment wish it to be assumed that we pretend--to cover exhaustively the various topics we discuss. Our endeavour, in the pages at our disposal, has not been to satisfy completely this first curiosity of the novice, but rather to stimulate and strengthen it, and guide it, so to say, on lines which will lead to a fuller and more detailed research. It is from this point of view, as a short yet comprehensive introduction, and particularly as an aid to the beginner in his choice of a school, and in what may be called his mental preparation for the stages of his tuition, that we desire our book to be regarded. C. G.-W. H. H. _April_, 1916. CHAPTER I THEORIES OF TUITION Only eight years ago, in 1908, it was declared impossible for one man to teach another to fly. Those few men who had risen from the ground in aeroplanes, notably the Wright brothers, were held to be endowed by nature in some very peculiar way; to be men who possessed some remarkable and hitherto unexplained sense of equilibrium. That these men would be able to take other men--ordinary members of the human race--and teach them in their turn to navigate the air, was a suggestion that was ridiculed. But Wilbur Wright, after a series of brilliant flights, began actually to instruct his first pupils; doing so with the same care and precision, and the same success, that had characterised all his pioneer work. And these first men who were taught to fly on strange machines--as apart from the pioneers who had taught themselves to fly with craft of their own construction--made progress which confounded the sceptics. They went in easy and leisurely fashion from stage to stage, and learned to become aviators without difficulty, and mainly without accident. After this, increasing in numbers from two or three to a dozen, and from a dozen to fifty and then a hundred, the army of airmen grew until it could be totalled in thousands. Instead of being haphazard, the teaching of men to fly became a business. Flying schools were established; courses of tuition were arranged; certain pilots specialised in the work of instruction. It was shown beyond doubt that, instead of its being necessary for an aviator to be a species of acrobat, any average man could learn to fly. Certainly a man who intends to fly should be constitutionally sound; this point is important. When in an aeroplane, one passes very quickly through the air, and such rapid movement--and also the effect of varying altitudes--entail a certain physical strain. A man with a weak heart might find himself affected adversely by flying; while one whose lungs were not sound might find that his breathing was impeded seriously by a swift passage through the air. More than one fatality, doubtful as to its exact cause, has been attributed to the collapse of a pilot who was not organically sound, or who ascended when in poor health. And here again is an important point. No man, even a normally healthy man, should attempt to pilot a machine in flight when he is feeling unwell. In such cases the strain of flying, and the effect of the swift motion through the air, may cause a temporary collapse; and in the air, when a man is alone in a machine, any slight attack of faintness may be sufficient to bring about a fatality. A fair judgment of speed, and an eye for distance, are very helpful to the man who would learn to fly, and it is here that a man who has motored a good deal, driving his own car, is at advantage at first over one who has not. But otherwise, and writing generally, any man of average quickness of movement, of average agility, can learn without difficulty to control an aeroplane in flight. It is wrong to imagine that exceptional men are required. An unusual facility, of course, marks the expert pilot; but we are writing of men who would attain an average skill. There has been discussion as to the age at which a man should learn to fly, or as to the introduction of age limits generally in the piloting of aircraft. But this introduces a difficult question; one which depends so entirely on the individual, and regarding which we need the data that will be provided by further experience. Some men retain from year to year, and to a remarkable extent, the faculties that are necessary; others lose them rapidly. The late Mr. S. F. Cody was flying constantly, and with a very conspicuous skill, at an age when he might have been thought unfit. But then he was a man of a rare vitality and a great enthusiasm--a man who, though he flew so often, declared that each of his flights was an "adventure." Taking men in the average one may say this: the younger a man is, when he learns to fly, the better for him. Much depends, naturally, on the sort of flying he intends to do after he has attained proficiency. If he is going to fly in war, or under conditions that impose a heavy strain, then he must be a young man. But if he intends to fly for his own pleasure, and under favourable conditions, then this factor of age loses much of its importance, and it is only necessary that a man should retain say, an ordinary activity, and a normal quickness of vision and of judgment. Flying is not difficult. It is in a sense too easy, and this is just where its hidden danger lies. If a pupil is carefully taught, and flies at first only when the weather conditions are suitable, he will find it surprisingly easy to pilot an aeroplane. That it is not dangerous to learn to fly is proved daily. Though hundreds and thousands of pupils have now passed through the schools, anything in the nature of a serious accident is very rarely chronicled. This immunity from accident is due largely to the care and experience of instructors, and also to the fact that all pupils pass through a very carefully graduated tuition, and that no hazardous flights are allowed; while another and an important element of safety lies in the fact that no flying is permitted at the schools unless weather conditions are favourable. It is now a fair contention that, provided a man exercises judgment, and ascends only in weather that is reasonably suitable, there is no more danger in flying an aeroplane than in driving a motor-car. Much depends of course on the dexterity of the pupil, and particularly on his manual dexterity--on what is known, colloquially, as "hands." Some men, even after they have been carefully taught, are apt to remain heavy and clumsy in their control. Others, though, seem to acquire the right touch almost by instinct; and these are the men who have in them the making of good pilots. Horsemen refer to "hands" when they speak of a man who rides well; and in flying, if a man is to handle a machine skilfully, there is need for that same instinctive delicacy of touch. Nowadays, when a pupil joins a well-established flying school, he finds that everything is made easy and pleasant for him. Most men enjoy very thoroughly the period of their tuition. A friendly regard springs up between the pupils and their instructors, and men who have learned to fly, and are now expert pilots, bear with them very pleasant reminiscences of their "school" days. But there were times, and it seems already in the dim and distant past, when learning to fly was a strange, haphazard, and hardly pleasant experience; though it had a sporting interest certainly, and offered such prospects of adventure as commended it to bold spirits who were prepared for hardship, and had a well-filled purse. The last requirement was very necessary. In the bad old days, amusing days though they were without doubt, no fixed charge was made to cover such breakages, or damage to an aeroplane, as a pupil might be guilty of during his period of instruction. These items of damage--broken propellers, planes, or landing gear--were all entered up very carefully on special bills, and presented from time to time to the dismayed novice; and a man who was clumsy or impetuous found learning to fly an expensive affair. There was a pupil who joined a school soon after Bleriot's crossing of the Channel by air. It was a monoplane school; and the monoplane, unless a man is careful and very patient, is not an easy machine to learn to fly. This beginner was not patient; he was indeed more than usually impetuous. His landings, in particular, were often abrupt. He broke propellers, frequently, to say nothing of wings and of alighting gear. And of all these breakages a note was made. Bills were handed to him--long and intricate bills, with each item amounting to so many hundreds of francs. Having a sense of humour, the pupil began to paper his shed with these formidable bills, allowing them to hang in festoons around the walls. What it cost him to learn to fly nobody except himself knew. He paid away certainly, in his bills for breakages, enough money to buy several aeroplanes. This was in the early days, when aviators were few and all flying schools experimental. To-day a pupil need not concern himself, even if he does damage a machine. Before beginning his tuition he pays his fee, one definite sum which covers all contingencies that may arise. It includes any and all damage that he may do to the aircraft of his instructors; it covers also any third-party claims that may be made against him--claims that is to say from any third person who might be injured in an accident for which he was responsible. This inclusive fee varies, in schools of repute, from £75 to £100. The modern aerodromes, or schools of flight, at which a pupil receives his tuition, have been evolved rapidly from the humblest of beginnings. The first flying grounds were, as a rule, nothing more than open tracts of land, such as offered a fairly smooth landing-place and an absence of dangerous wind-gusts. Then, as aviation developed, pilots came together at these grounds, and sheds were built to house their craft. And after this, quickly as a rule, an organisation was built up. Beginning from rough shelters, erected hastily on the brink of a stretch of open land, there grew row upon row of neatly-built sheds, with workshops near them in which aircraft could be constructed or repaired. And from this stage, not content with the provision made for them by nature, those in control of the aerodromes began to dig up trees, fill in ditches and hollows, and smooth away rough contours of the land, so as to obtain a huge, smooth expanse on which aircraft might alight and manoeuvre without accident. And after this came the building up of fences and entrance gates, the erection of executive offices and restaurants, the provision of telephone exchanges and other facilities--the creation in fact of a modern aerodrome. A pupil to-day, if he decides to learn to fly, finds he has an ample choice in the matter of a school. He may feel indeed that there is almost an embarrassment of facilities. But there are certain very definite requirements, in regard to any modern flying school; and if a novice bears these in mind, and thinks of them carefully when he is considering what school he shall join, he cannot go far wrong. First there is the question of the aerodrome on which, and above which, the pupil will undergo his instruction. This should be of ample size and of an adequately smooth surface; and it should be so situated, also, that it is free from wind eddies and gusts, such as are set up by hills, woods, or contours of the land, and are likely to inconvenience a novice when he makes his first flights. The best position for an aerodrome is in a valley, not abrupt but gently sloping. With a flying ground so placed, shielded well by nature on every hand, it may prove sufficiently calm for instruction even on days when there is a gusty wind blowing across more exposed points; and such a natural advantage is of importance for a pupil. It may mean that he is obtaining his tuition from day to day, when other pupils, learning to fly at grounds less favourably situated, have to remain compulsorily idle, waiting either for the wind to drop, or to veer to some quarter from which their aerodrome is sheltered. It is very necessary, of course, in the operation of a flying school, that there should be competent instructors; also a sufficient number of these to prevent them from being over-taxed, or having more pupils at any one time than they can handle conveniently. And it is greatly to the advantage of a pupil if these instructors have been chosen with an intelligent care. A man may be a capable pilot, and yet not have the temperament that will suit him for imparting his knowledge to others. The instructor who, besides being a fine flyer, has the patience and sympathy of a born teacher, is by no means easy to find. A school which does find such men, and retains their services, offers attractions for a pupil which--in any preliminary visit he pays to a school before joining it--he should look for keenly. And he should make certain, too, that the school has a staff of skilled and experienced mechanics. Another indispensable feature of a school is a sufficient number of aeroplanes, machines suited specially for the purposes of tuition, and maintained at a high efficiency. It has been no uncommon thing--though here again one is writing of the past--for the total resources of a school to comprise, say, two machines. Hence a couple of smashes would put such a school temporarily out of action, and leave the pupils with nothing to do but kick their heels, and wait until the machines had been repaired. It is certainly an advantage, from the pupil's point of view, if there are well-equipped workshops in connection with the school he joins; also if the proprietors of his school have an ample supply of engines. With facilities for repair work immediately at hand, and with a spare engine ready at once to put in a machine--while one that has been giving trouble is dealt with in the engine-shop--there should always be a full complement of craft for the work of instruction. When workshops are in operation in connection with a school an opportunity is usually provided, also, for a novice to gain some knowledge as to the mechanism and working of the aero-motor: and this of course will be useful to him. There has been discussion as to the type of aeroplane on which one should learn to fly; but in this question, as in that of an age limit for airmen, it is extremely difficult, besides being unwise, to attempt to frame a hard-and-fast rule. The monoplane, for instance, is not an easy machine to learn to fly: it is not easy, that is to say, compared with certain types of biplane. Yet numbers of pupils have been taught on monoplanes, and this without accident. There is also a question whether, among biplanes, it is best to learn on a tractor machine--one that is to say with the engine in front of the main planes--or on a "pusher" type of craft; this last mentioned having its motor behind the planes. Aeroplanes of both types are in use; and it would be advantageous, of course, for a novice to accustom himself to handle either. But from the point of view of those who operate large flying schools, and have to weigh one point against another, and eliminate so far as possible the elements of risk or difficulty, there are very distinct advantages in a "pusher" biplane, such as is illustrated facing page 34. The control of such a machine is simple, and can be grasped quite readily. It provides the novice, when he is seated in it, with a clear and unobstructed view of the ground immediately in front of and below him; and this, in the early stages of tuition, is an extremely important point. A craft of such a type, also, when built specially for instruction, can be given a very strong alighting gear, and this makes for safety when a pupil is in his first tests, and may be guilty of an abrupt or rough descent. Again, while such a school machine as this is engined adequately, it is at the same time comparatively slow in flight, and has the advantage also that it will alight at slow speeds. In the air, too, it has a large measure of stability, and is not too rapid in its response to its controls. It gives a pupil what is very necessary for him in his first flights, and that is a certain latitude for error. It is safe to say, indeed, without being dogmatic, that a "pusher" biplane of the type illustrated, if constructed specially for school work, offers a pupil two very clearly marked advantages. These are: (1) A craft which he can learn to fly quickly; and (2) A machine on which he can pass through his tuition with the least risk of accident. This last-mentioned point is, naturally, one of extreme importance. It is very necessary, apart from any question of personal injury, that a pupil should be protected during his tuition from anything in the nature of a bad smash. A man should start to learn to fly with full confidence; the more he has the better, provided it is tempered with caution. And if he can go through his training without accident, and preserve the steadily growing confidence that his proficiency will give him, he is on the high road to success as a pilot. But if he meets with an accident while he is learning--some sudden and quite unexpected fall--this may have a serious and a permanent influence on his nerves, even if he escapes without injury. It happened frequently in the early days that a promising pupil, a man who showed both confidence and skill, had his nerve ruined, and all his "dash" taken from him, by some unlucky accident while he was learning to fly. There are certain minor points a pupil should consider when he selects a flying school--points which have reference mainly to his own comfort and convenience. He will prefer, for instance, other things being equal, a school that is near some large town or city, and not buried away inaccessibly. It is a convenience also, and one that facilitates instruction, if a pupil can obtain, quite near the aerodrome, rooms where he can live temporarily while undergoing his instruction, and so be able to reach the flying ground in a minute or so, whenever and at any time the weather conditions are favourable. It is a convenience again if, either on the aerodrome itself or immediately adjacent, there is a canteen or restaurant where meals and other refreshments can be obtained. Dressing-rooms and reading rooms, when provided by the proprietors of a school, add to the comfort of the novice while he is in attendance on the aerodrome. In winter, particularly, such facilities are required. At a modern school, if it is well conducted, all heroics or exceptional feats are discouraged. Pupils who want to do wild things must be sternly repressed, even if only for the common good. The aim is to train a certain number of pupils, not hastening over the tuition but giving each man his full and complete course, and to do this with a minimum of risk. In the early days of flying there were remarkable exploits at the schools, and some very dangerous ones also. But nowadays the reckless, happy-go-lucky spirit has gone. Tuition is based on experience. Each pupil must submit to the routine, and listen attentively to the instructions given him. There are no short cuts--not at any rate with safety--in the art of learning to fly. The question is asked, often, how long it should take a man to learn to fly. It is almost impossible, though, to specify any fixed time. A very great deal must depend on the weather. A pupil who joins a school in the summer is more likely, naturally, to complete his tuition quickly than one who begins in the winter. In periods when there are high and gusty winds it may be necessary to suspend school work for several days. But at such times the pupil need not be completely idle. Lectures on aviation are organised sometimes by the schools; while a pupil should have opportunities also--as has been mentioned before--of going into the engine-shop and studying the repair and overhaul of motors and machines. It is on record that a pupil has learned to fly in a day, even in a few hours; but here the circumstances, and the men, were exceptional. Such an unusual facility represents one extreme; while as another, it may happen that a man, owing to a combination of adverse circumstances, is six months before he gains his certificate of proficiency. It may be taken, as a rule, that a pupil should set aside say a couple of months in order to undergo thoroughly, and without any haste, his full period of tuition. School records prove, as a rule, that the pilots who learn to fly abnormally quickly are apt to experience an abnormal number of accidents at a later date, due principally to a lack of real sound knowledge, which they should have gained during the period of their tuition. One must learn to walk before one can run, and this takes time; and the remark applies aptly to aviation. It is very necessary for the pupil to spend as much time as he can on the aerodrome. Much is to be learned, by an observant man, apart from the actual time during which he is engaged with his instructor. If he watches men who are highly skilled, he may gain many useful hints, though he himself is on the ground. CHAPTER II TEMPERAMENT AND THE AIRMAN As aviation passed from its earliest infancy, and a number of men began to fly, the temperament of the individual pupil, and the effect of this temperament on his progress as an aviator, began to reveal itself. And temperament does play a large part in flying; as it does in any sport in which a man is given control of a highly sensitive apparatus, errors of judgment in the handling of which may lead to disaster. It is not, as a rule, until he has passed through his early stages of tuition, and has begun to handle an aeroplane alone, and is beyond the direct control of his instructor, that the temperament of a pupil really plays its part. Up to this point he is one among many, conforming to certain rules, and obliged to mould himself to the routine of the school. But when he begins to fly by himself, and particularly when he has passed his tests for proficiency, and is embarking, say, on cross-country flights, then this question of temperament begins really to affect his flying. All men who learn to fly--numbering as they do thousands nowadays--cannot be endowed specially by nature for their task. There is indeed a wide latitude for temperamental differences--always provided that nothing more is required of a man than a certain average of skill. But if a man is to become a first-class pilot, one distinctly above the average, then the question of his temperament, as it influences his flying, is certainly important. A rough classification of the pupils at a school--just a preliminary sorting of types--shows as a rule the existence of two clearly-marked temperaments. One is that of the man who is deliberate, whose temperament guards him from doing anything perfunctorily or in a hurry; the other is that of a man--a type frequently encountered nowadays--who while being quick, keen, and intelligent, mars these good qualities by a temperamental impatience which he finds it difficult or impossible to control, and which makes him irritable and restless at any suggestion of delay. Now the first of these men need not to be wholly commended, nor the second entirely condemned. A capacity for deliberation, both in study and in practice, is very useful when learning to fly. It will protect a man from many errors, and render his progress sure, though it may be slow. But something more than deliberation is required in the aviator of distinction. There must be the vital spark of enterprise, the temperamental quality which is known as "dash," the quick action of the mind, in difficulty or peril, that will carry certain men to safety through many dangers. This imaginative power is possessed as a rule, though in ways that differ considerably, by the second type of pupil we have described--the restless, impatient man. But in his case this quality is, more often than not, marred by his instability; by the lack of that judgment which is so necessary to counterbalance imagination, but which is, unfortunately, not so often found. A man who decides to become an aviator, and particularly if he intends to fly professionally, should ask himself quite seriously if his temperament is likely to aid him, or whether perhaps it may not be a danger. This point is certainly one of importance, though it cannot be stated directly or decided in so many words. There is a vital question at least that the novice should ask himself; and this is whether his temperament, whatever its general tendency may be, includes a sufficient leavening of caution. In the navigation of the air caution is indispensable. A pupil must remind himself constantly that, though it appears easy--and is indeed easy--to learn to handle a machine in flight, no liberties must under any circumstances be taken with the air. Every instant a man is flying he needs to remember the value of caution. In the air one cannot afford to make mistakes. Naturally there is an ideal temperament for flying; but it is one which, owing to the combination of qualities that are required, is very rarely met with. The man who possesses it is gifted with courage, ambition, "dash," and with a readiness in an emergency that amounts to intuition. And yet these positive qualities are, in the ideal temperament, allied to, and tempered by, a strong vein of prudence and of caution. The pilot has absolute system, method, and thoroughness in everything he does. The average pupil cannot hope to be so luckily endowed. But he can study his personality, and seek to repress traits that may seem harmful. There is need in flying for a sound judgment, one that will enable a man to come to a decision quickly and yet accurately. Things happen rapidly in the air. It is one of the grim aspects of flying that, just at a moment when everything appears secure, a sudden disaster may threaten. So it is of vast importance to a pilot, if he has to fly regularly, that he should have an instinctive and dependable judgment; a capacity for deciding quickly and without panic; a capacity, when several ways present themselves of extricating himself from some quandary, of being able to choose the right one, and of not having to think long before doing so. This implies a combination really of judgment and resource. The man of confidence, the man of resource, is well endowed for flying. But he must not be over-confident. The over-confident man is a menace to himself and to others. It is not a proper spirit at all in which to approach aviation. We do not know enough about the navigation of the air to be in the least over-confident. The spirit, rather, should be one of humility--a determination to proceed warily, and to make very certain of what limited knowledge we do possess. Two of the worst traits in an aviator are impatience and irritability. A man who has these temperamental drawbacks in a form which is strongly marked, and who cannot control them, should not think of becoming an aviator. The man who is impatient and irritable finds himself out of harmony with the whole theory of aerial navigation. There is a long list of "don'ts" in flying; in the handling of one's machine, in the weather one flies in, in all the feats that one should attempt and leave alone. A number of details must be memorised, and must never be forgotten or overlooked, trivial though some of them may seem. The frame of mind of the man who flies must be alert, yet quiet and reposeful; he must be clear-headed, not hot-headed. The man who is in a hurry, who ignores details when he sets out on a flight, is the man who runs risks and is bound sooner or later to pay the penalty. The perils of recklessness in flying are very great. The man who "takes chances," who thinks he can do something when, as a matter of fact, he has neither sufficient knowledge or experience, runs a very grave and constant risk. It is the thoughtful, considering frame of mind, particularly in a pupil, which is the safe one; but this must not be taken to imply a type of man who lacks power of action. Initiative, and a quick capacity for action, are most necessary in aviation. New problems are being faced continually, and the brain succeeds which is the most active and original. CHAPTER III FIRST EXPERIENCES WITH AN AEROPLANE (AS DESCRIBED BY MR. GRAHAME-WHITE) After a period of ballooning, which offers experience for an aviator in the judging of heights and distances, and in growing accustomed to the sensation of being in the air, I devoted a good deal of time and attention--more indeed at the time, and in view of my other responsibilities, than I could reasonably spare--to a study of the theory of aeroplane construction, and to the making of models. This was prior to 1909; Bleriot had not yet flown the Channel in his monoplane. But when he did I put models aside, and determined to buy an aeroplane and learn to fly. At the end of August, 1909, so that I might inspect the various aeroplanes that were then available, and they were few enough, I went to Rheims, in France, and attended the first flying meeting the world had seen. At the aerodrome I met and talked with the great pioneers: with Bleriot, fresh from his cross-Channel triumph; with Levavasseur, the designer of the beautiful but ill-fated Antoinette monoplane, which had, through engine failure, let Hubert Latham twice into the Channel during his attempts to make the crossing; with Henry Farman who, fitting one of the first Gnome motors to a biplane of his own construction, flew for more than three hours at Rheims, and created a world's record; and also with M. Voisin, whose biplane was then being flown by a number of pilots. Finally, after careful consideration, I made a contract with M. Bleriot to purchase from him, at the end of the meeting, a monoplane of a type that appeared first at Rheims, and of which there was not another model then in existence. This machine differed considerably from the one with which M. Bleriot had flown the Channel. His cross-Channel monoplane was a single-seated craft fitted with an air-cooled motor of about 25 h.p. The machine I agreed to buy at Rheims, and which was known as Bleriot No. XII., would carry two people, pilot and passenger, while it had an 8-cylinder water-cooled motor developing 60 h.p.--an exceptional power in those days. The position of the occupants, as they sat in the machine, differed from the arrangement in the cross-Channel Bleriot. In the latter the pilot sat in a hull placed between the planes, and with his head and shoulders above them. But in this new and larger machine the pilot and passenger sat in seats which were placed below the planes. The craft was, as a matter of fact, an experiment, being built almost purely for speed; hence its powerful motor. M. Bleriot's idea, in constructing it, was to have a machine with which he might win the Gordon-Bennett international speed race at Rheims. But this hope he did not realise; nor did I obtain delivery of the craft I desired. Bleriot, flying alone in this big monoplane, started in a speed flight for the Gordon-Bennett; but he was only a quarter of the way round the course, on his second lap, when the machine was seen to break suddenly into flames and crash to the ground from a height of 100 feet. It was wrecked entirely, but Bleriot was fortunate enough to escape with nothing worse than burns about the face and hands, and a general shock. The cause of the accident was that an indiarubber tube, fixed temporarily to carry petrol from the tank to the carburettor, had been eaten through and had permitted petrol to leak out, and to ignite, on the hot exhaust pipes of the motor. The destruction of this monoplane was, to me, a great disappointment. No other machine of the type was in existence, and I learned that it would take three months to build one. M. Bleriot promised, however, to put a machine in hand at once; and, as a special concession, I obtained permission to go daily to the Bleriot factory and superintend the construction of my own machine. This I did for a full period of three months, working daily from 6 a.m. to 6 p.m., and gaining some valuable knowledge as to aeroplane construction. On November 6, 1909, after delays which had tried my patience sorely, I obtained delivery of the new machine--a replica of the craft that had been destroyed at Rheims. It was too late that day to begin any trials, so I and a friend who was with me arranged with M. Bleriot's mechanics that we would be at Issy-les-Moulineaux early next morning, and there put the craft through its preliminary tests. I can remember we went to bed early, but sleep was impossible; we were both too excited at the prospect that lay before us. So presently we got up--this was at 2 a.m.--and drove out to the flying ground. It was pitch dark when we arrived at the aerodrome, but the morning promised to be favourable. Foggy it was; but there was no wind, and the fog seemed likely to clear. We roused the caretaker, and, after lengthy explanations and considerable monetary persuasion, induced him to open the shed and allow us to prepare the machine for its first flight. Then we waited for the mechanics and the first rays of dawn. We felt a desire to get the big engine started up, but had been warned of the risk of doing this without the help of mechanics. Time passed and still the mechanics did not come. At last, there being now sufficient light, we tied the aeroplane with ropes to a fence, so as to prevent its leaping forward, and then started up the motor by ourselves. I swung the nine-foot propeller--the only way of starting the engine; and at the first quarter-turn the motor began to fire. Then, as is quite usual, there was an incident that had been unforeseen in our excitement. We had forgotten to take up the slack of the rope; and the consequence was that, as the engine started, the machine gave a bound forward that was sufficient to knock me down. But I was unhurt, and picked myself up quickly. Then I hurried round to the driving seat and took my place at the control levers, motioning to my friend, who was looking after the ropes, to cast these loose and jump into the seat beside me. This was easier said than done. Directly he released the ropes the machine began to move across the ground, gathering speed very quickly; but he managed somehow, before the machine was running too fast, to scramble into the seat beside me. Off we started across the aerodrome, the monoplane gaining a speed of 40 or 50 miles an hour. I did not attempt to rise from the ground, feeling it very necessary at first to grow familiar with the controls. So we sped along the ground for a distance of about a mile. Then, on nearing the far end, I slowed down the motor and our speed dropped to about 20 miles an hour. I wanted to turn the machine round on the ground and run back again towards our starting point. But such a manoeuvre, particularly for the novice, is far from easy. As the speed of the machine is reduced, the pressure of air on the rudder is lessened and so it loses its efficiency--in the same way that a ship is difficult to steer when she begins to lose way. We were faced also by another and a graver difficulty. Confused by the fog, which still hung over the aerodrome, I had misjudged our position. We found we were much nearer the end of the ground than I had imagined. In front of us there loomed suddenly a boundary wall, against which it seemed probable we should dash ourselves. There were no brakes on the machine; no way of checking it from the driving seat. Our position seemed critical. It was now that I shouted to my friend, telling him to jump out of the machine as best he could, and catch hold of the wooden framework behind the planes, allowing the machine to drag him along the ground, and so using the weight of his body as a brake. This, with great dexterity, he managed to do, and we came to a standstill not more than a foot or so from the wall. This proved a chastening experience; we pictured our aeroplane dashed against the wall, and reduced to a mass of wreckage. Very cautiously we lifted round the tail of the machine. It was impossible to switch off the motor and have a rest, because, if we had stopped it, we should not have been able to start it again without our gear, which was away on the other side of the ground. Now, having got the machine into position for a return trip across the aerodrome, I accelerated the engine, and we started off back. For about twenty minutes, without further incident, we ran to and fro; and now I felt that I had the machine well in control--on the ground at any rate. And so the next thing was to rise from the ground into the air. I told my friend my intention, calling to him above the noise of the motor; and I admired him for the calm way in which he received my news. I should not have been surprised if he had demanded that I should slow up the machine and let him scramble out. In those days it was thought dangerous to go up even with a skilled and more or less experienced pilot. How much greater, therefore, must have seemed the risk of making a trial flight with me--a complete novice in the control of a machine. But my friend nodded and sat still in his seat. So I accelerated the motor and raised very slightly our rear elevating plane. And then we felt we were off the ground! There was no longer any sensation of our contact with the earth--no jolting, no vibration. In a moment or so, it seemed, the monoplane was passing through the air at a height of about 30 feet. This, to our inexperienced eyes, appeared a very great altitude; and I made up my mind at once to descend. This manoeuvre, that of making contact with the ground after a flight, I had been told was the most difficult of all. It is not surprising that this should be so. Our speed through the air was, at the moment, about 50 miles an hour; and to bring a machine to the ground when it is moving so fast, without a violent shock or jar, is a manoeuvre needing considerable judgment. But, remembering that the main thing was to handle the control lever gently, I managed to get back again to the aerodrome without accident; and after this we turned the machine round again and made another flight. The fog had cleared by now, and we were surprised to see a number of people running across the ground towards us. First there came the tardy mechanics; and with them were a number of reporters and photographers representing the Paris newspapers. These latter had--though I only found this out afterwards--been brought by the mechanics in the expectation of being able to record, with their notebooks and cameras, some catastrophe in which we were expected to play the leading parts. Knowing the powerful type of monoplane I had acquired, a machine not suited for a novice, the mechanics had felt sure some disaster would overtake me. But, as it happened, their anticipations were not fulfilled. The journalists and photographers did not, however, have a fruitless journey. Though there was nothing gruesome to chronicle, they found ample material, when they learned of them, in the early morning adventures of myself and my friend with this 60 h.p. monoplane. Next day, in fact, our exploits were given prominence in the newspapers, and I received a number of congratulatory telegrams; not forgetting one of a slightly different character which came from M. Bleriot. He was flying at the time in Vienna, and he warned me of the dangers of such boldness as I had displayed--having regard to the speed and power of my machine--and pleaded with me for a greater caution. CHAPTER IV THE CONTROLLING OF LATEST-TYPE CRAFT People are puzzled, often, when they try to explain to themselves how it is that an aeroplane, which is so much heavier than air, manages to leave the ground and to soar in flight. When balloons or airships ascend, it is realised of course that the gas, imprisoned within their envelopes, draws them upward. But the aeroplane--weighing with pilot, passenger, and fuel perhaps several thousand pounds--rises without the aid of a gas-bag and with nothing to sustain it but narrow planes; and these do not beat, like the wings of a bird, but are fixed rigidly on either side of its body. How is the weight of machine and man borne through this element we cannot see, and which appears intangible? The secret is speed--the sheer pace at which an aeroplane passes through the air. As a craft stands on the ground, its planes are inoperative. Power lies dormant in the air, but only when it is in motion, or when some object or apparatus is propelled through it at high speed. Have you stood on a height, in a gale, and felt an air wave strike powerfully against your body? The blow is invisible; but you yield a step, gasping; and, had you wings at such a moment, you would not doubt the power of the wind to sweep you upward. This is the force the aeroplane utilises. If, on a calm day, you accelerate your motor-car to 60 miles an hour, the air sweeps past you in a powerful stream; just as it would if you were standing still, and there was a gale of wind. Instead of the wind possessing the speed, in this instance, it is you who provide it. The motor of an aeroplane, driving the propeller of the machine, turns this at 1000 or more revolutions a minute, and causes its curved blades to screw forward through the air as they turn, like those of a ship's propeller through water--or a gimlet into wood. The propeller, as it bores its way into the air, draws or pushes the aeroplane across the ground; and the speed grows rapidly until the air, sweeping with an increasing pressure beneath the planes, becomes sufficient to bear the craft in flight. But the wing of an aeroplane would not sustain its load unless designed specially to act upon the air. A man, if he is unlucky enough to fall from a tall building, passes through the air at a high speed. His body obtains no support from the air; so he crashes to the ground. This is because his body is heavy, and presents only a small surface to the air. To secure a lifting influence from the air, it must be struck swiftly with a large, light surface. Men go to Nature when building wings for aeroplanes, and imitate the birds. The wing of a bird arches upward from front to back, most of the curve occurring near the forward edge; and this shape, when applied to an aeroplane wing, is known as its camber. With an aeroplane wing, if its curve is adjusted precisely, the air not only thrusts up from below as a machine passes through it, but has a lifting influence also from above; an effect that is secured by the downward slope of the plane towards its rear edge. The air, sweeping above the raised front section of the plane, is deflected upward, and with such force that it cannot descend again immediately and follow the downward curve of the surface. So, between this swiftly-moving air stream, and the slope to the rear of the plane, a partial vacuum is formed, and this sucks powerfully upward. With a single wing, therefore, it is possible to gain a double lifting influence--one above and one below. The building of aeroplanes, once their wing lift is known, becomes a matter of precision. According to the speed at which they fly, and the size and curve of their planes, machines will sustain varying loads. In some machines, as a general illustration--craft which fly fast--the planes may bear a load equal to 10 lbs. per square foot. In others the loading may be less than 3 lbs. per square foot. Apart from raising a craft into the air, by the lifting power of its wings, there is the problem of controlling it when in flight. The air is treacherous, quickly moving. Gusts of abnormal strength, sweeping up as they do invisibly, may threaten to overturn a machine and dash it to earth. Eddies are formed between layers of warm and cold air. There are, as a craft flies, constant increases or lessenings of pressure in the air-stream that is sweeping under and over its wings; and all these fluctuations influence its equilibrium. Unless, therefore, a machine is automatically stable--and with craft of this type we shall deal later--the pilot must be ready, by a movement of the surfaces which govern the flight of the machine, to counteract quickly, with a suitable action of his levers, the overturning influence that may be exercised by a gust of wind. Here lies the art of flying. A man is given a machine which, by the action of its motor and propeller, will raise itself into the air; and it is his task, when the craft is once aloft, to manipulate it accurately and without accident, and to bring it to earth safely after he has made a flight. In the description of controlling movements which follows we shall, for the sake of convenience, and for the sake also of brevity, deal only with the type of "pusher" biplane to which reference has been made already, and on which large numbers of pupils have been, and are being, trained to fly. This casts no aspersion whatever on tractor machines or on monoplanes. On either, if he has an inclination, a pupil can undergo his instruction, and do so usually with success. But explanation is rendered more easy, and there is less likelihood of a dispersal of interest, if one machine is selected for illustration; and our reasons for the choice of a "pusher" biplane, regarded from the point of view of tuition, have been explained already. First, therefore, one may deal with raising the craft into the air, and causing it to descend. In the photograph of the school machine shown facing this page, it will be seen that the control surfaces are indicated by lettering. In front of the biplane, on outriggers, is the plane "A." This surface (aided in its action by a rear plane) governs the rise or descent of the machine. When the motor is started, and the propeller drives the biplane across the ground on its chassis B, the machine would, if this lifting plane was held in a negative position, continue to move forward on the earth and would make no attempt to rise. In order to leave the ground, when the speed of the machine is sufficient for its main-planes (C.C.) to become operative, and bear its weight through the air, the pilot draws back slightly towards him a lever, which is placed just to the right of his driving-seat and is held with the right hand. A photograph which shows this lever, and the other controls, appears facing page 36, the lever to which we are referring being indicated by the figure 1. The effect on the aircraft when the pilot draws back this lever--the motion being slight and made gently--is to tilt up the elevating plane A, and this in its turn, owing to the pressure of air upon it, raises the front of the machine. The result of this alteration in the angle of the craft is that it presents its main-planes at a steeper angle to the air. Their lifting influence is increased, with the result that--at an angle governed by the pilot with his movement of the elevating plane--they bear the machine from the ground into the air. [Illustration: GRAHAME-WHITE SCHOOL BIPLANE (TYPE XV.) _Photo by Topical Press Agency._ A.--The front elevating plane, which acts in conjunction with the rear-plane marked A1; B.--The landing-chassis; C.C.--The main-planes; D.D.--The ailerons; E.E.--The rudders; F.--Engine (a 60-h.p. Le Rhone) and propeller.] A reverse movement of the elevator reduces the lift of the main-planes; hence, when an aviator wishes to descend, he tilts down his elevator, bringing his machine at such an angle that it is inclined towards the ground. Then, switching off his engine so as to moderate the speed of his descent, and by such manipulations as may be necessary of his elevator, he pilots his craft to earth in a vol-plané, during which gravity takes the place of his motor, and he is able--by steadying his machine and bringing it into a horizontal position just at the right moment--to make a gentle contact with the ground. A pilot must be able to do more than cause his aeroplane to ascend and to alight: he must have means to check the lateral movements which, under the influence of wind gusts, may develop while the biplane is in flight. At the rear extremities of the main-planes as illustrated in the photograph facing page 34--and marked D.D.--are flaps, or ailerons, which are hinged so that they may be either raised or lowered. These ailerons are operated, through the medium of wires, by the same hand-lever which governs the movement of the elevator. This lever is mounted on a universal joint, and can be moved from side to side as well as to and fro. Should the biplane tilt, while flying, say towards the left, the pilot moves his hand-lever sideways towards the right. This is a natural movement, the instinct being to move the lever away from the direction in which the machine is heeling. This movement of the lever has the effect of drawing down the ailerons on the left-hand side of the machine; on the side, that is to say, which is tilted down; and the depression of these auxiliary surfaces, increasing suddenly as they do the lifting influence of the main-planes to which they are attached, tend to thrust up the down-tilted wings, and so restore the equilibrium of the machine. In the operation of his ailerons, combined with the use of his elevator, a pilot is given means to balance his craft while in flight. One should not gain the impression that an aeroplane is threatening ceaselessly to heel this way and that. This is not so. The machine has a large measure of stability, apart from any manipulation of its controls, and needs balancing only when some disturbance of the atmosphere affects its equilibrium. Under favourable conditions, such as a pupil will experience in his first flights, nothing more is necessary with the hand-lever than a very slight but fairly constant action; a similar motion, in a way, as is made by the driver of a motor-car when he maintains, by his "feel" on the wheel, his sense of control over the machine. In the controlling actions of an aeroplane--and this is a fact which tends sometimes to the confusion of the novice--nothing more is required, normally, than the most delicate of movements. The difference say between ascending, and skimming along the ground, is represented by a movement of the hand-lever of only a few inches. Delicate, sure, quick, and firm; such is the touch needed with an aeroplane. With the one hand-lever, as we have shown, it is possible for a pilot to control the rise and descent, and also the lateral movements of his machine; and there remains only the steering to be effected--the movement from side to side, from right to left, or vice-versa. At the rear of the biplane, as shown facing page 34, will be seen two vertical planes, E.E. These, being hinged, will swing from side to side; and they exercise a sufficient influence, when working in the strong current of air that blows upon them when a machine is in flight, to steer it accurately in any direction. The pilot, to operate this rudder, rests his feet on a conveniently-placed bar, which is mounted on a central swivel, and allows the bar to be swung by a pressure of either foot. When the pilot needs to make a turn say to the left, as he is flying, he presses his left foot forward. This swings the bar in same direction; and, by a simple connection of wires running to the tail of the machine, the rudders are made to swing over to the left also, and the machine turns in response to them. A similar movement to the right produces a right-hand turn. This foot rudder bar, being numbered 2, is shown in the picture facing page 36. [Illustration: THE CONTROLS OF A SCHOOL BIPLANE. _Photo by Topical Press Agency._ 1.--The upright lever which, working on a universal joint, operates the elevator and ailerons; 2.--The bar, actuated by the pilot's feet, which operates the rudders of the machine; 3.--The pilot's seat; 4.--The passenger's seat.] Apart from the movements we have described, which are extremely simple, a pilot needs also to maintain control over his motor. Near his left hand, fixed to the framework just at one side of his seat, are levers which govern the speed of the engine, also the petrol supply; while close to them is the switch by which the ignition can be switched on or off. A final word is necessary here, perhaps, and it is this: the glamour and mystery which, in the early days, clung to the handling of an aeroplane has now been dispelled almost entirely. A well-constructed machine, flying under favourable conditions, requires surprisingly little control; what it does, one may almost say, is to fly itself. CHAPTER V THE STAGES OF TUITION Flying schools--those which really can be described as such--have been in operation now for seven years; and during this time, with thousands of pupils going through their period of tuition, many very valuable lessons have naturally been learned. To-day, at a well-managed school, each stage in a pupil's instruction, mapped out as a result of experience, is arranged methodically and with care; the idea being that the novice should pass from one stage to another by a smoothly-graduated scale, facilitating his progress and reducing elements of risk. It is in the early morning, and again in the evening, that the flying schools are most busy as a rule. At such times--morning and evening--the wind blows with least violence; and it is very necessary that a pupil, when he is handling craft for the first time, should have weather conditions which are favourable. Summer and winter, as soon as it is light, and granted conditions appear suitable, mechanics wheel the aeroplanes from the sheds, and the instructors begin their work. Should there be any doubt as to the weather, or as to the existence, say, of difficult air currents, an instructor will fly first, circling above the aerodrome at various heights, and satisfying himself, by the behaviour of his machine, whether it will be safe for the novices to ascend. If he pronounces "all well," school work begins in earnest, and continues--provided the weather remains favourable--until all the pupils have had a spell of instruction. Towards the middle of the day, and in the afternoon, it is quite likely the wind may blow and school work be suspended. But in the evening again, when there is usually a lull, a second period of instruction will be carried out. In well-equipped schools, to meet such conditions as these, it is customary to provide two complete and distinct staffs, both of instructors and mechanics. One staff takes the morning spell of work, while the second is held in readiness for the evening. This ensures that, both morning and evening, there shall be available for instruction a fresh, alert, and unfatigued staff. [Illustration: REAR VIEW OF A SCHOOL BIPLANE. _Photo by Topical Press Agency._ This photograph shows clearly the hinged ailerons fixed at the extremities of the plane-ends for maintaining lateral stability: also the rear elevating plane (which acts in conjunction with the fore-plane mounted on outriggers at the front of the machine) and the twin rudders.] A pupil will find that, as the first stage of his tuition, he is given the task of familiarising himself with the controls of a school biplane. The system we have described already, and a pupil should find no difficulty in mastering it. Placing himself in the driving-seat of the machine, while it is at rest on the ground, the pupil takes the upright lever in his right hand, and rests his feet on the rudder-bar, making the various movements of control, again and again, until he finds he is growing accustomed to them, and can place his levers in a position for an ascent or descent, or for a turn, without having to wait while he thinks what it is necessary to do. In the next stage, a more interesting one, the pupil, occupying a seat immediately behind his instructor, is taken for a series of passenger flights. These accustom him to the sensation of being in the air, and also train his eye in judging heights and distances. A minor point the pupil should bear in mind, though his instructor will be quick to remind him, is not to wear any cap or scarf that may blow free in the rush of wind and become entangled with the propeller. Scarves need to be tightly wrapped; while it is usual, with a cap, to turn it with the peak to the back, and so prevent it from having a tendency to lift from the head. Many pupils provide themselves with a helmet designed to protect the head in case of an accident, and these are held firmly in position. Should a passenger's cap blow off, and come in contact with the propeller, it may be the cause of an accident. How carelessness may lead to trouble, in this regard, will be gathered from the following incident. Some slight repairs had been made one day to the lower plane of a machine while it stood out on the aerodrome, and one of the workmen, through inadvertence, had left lying on the plane, near its centre, a roll of tape. The pilot decided to make another flight, and the motor was started and the machine rose. Suddenly the aviator was startled by a sound like a loud report, which seemed to come from the rear of his machine. The craft trembled for a moment, and he feared a structural collapse. Nothing worse happened, however, and he was able to pilot his machine in safety to the aerodrome. What had happened, it was then ascertained, was that the roll of tape, sucked back in the rush of wind, had been drawn into the revolving propeller and had broken a piece out of it. Luckily the impact had not been heavy enough to damage the propeller seriously, or cause it to fly to pieces. A problem with which the pupil will be faced in his first flights, particularly if he is learning in winter, will be that of keeping himself warm. The speed at which an aeroplane travels, combined with the fact that it is at an elevation above the ground, renders the "bite" of the cold air all the more keen, and makes it difficult very frequently, even when one is warmly clad, to maintain a sufficient warmth in the body, and particularly in the hands and feet. The question of cold hands is, from a pilot's point of view, often a serious one. There is a case on record of an aviator who, his hands being so numbed that his fingers refused to move, found he could not switch off his motor when the time came to descend; and so he had to fly round above the aerodrome, several times, while he worked his numb fingers to and fro, and beat some life into them against his body. At last, having restored their circulation to some extent, he was able to operate the switch and make a landing. While on active service in winter, after flying several hours at high altitudes, and in bitter cold, the occupants of a machine have descended in such a numbed condition, despite their heavy garments, that it has been found necessary to lift them out of their seats. But a pupil need not face such hardships as these. He will be flying for short periods only, and at low altitudes; so if he makes a few wise purchases from among the selection of flying gear now available, and particularly if he equips himself with some good gloves, he should be able to keep sufficiently warm in the air, even if he is going through his training in winter. [Illustration: POWER-PLANT OF A SCHOOL BIPLANE. _Photo by Topical Press Agency._ Showing the 60-h.p. Le Rhone Motor, with its mounting on the machine, and the method of attaching the propeller. The fuel tank is also visible; and, forward at the front of the machine, the seats of passenger and pilot.] A pupil will feel curious, naturally, as to his sensations in the first flights he makes with his instructor. Of the exact moment when the machine leaves ground he will be unaware probably, save for the cessation of any jolting or vibration, such as may be caused by the contact of the running wheels with the surface of the aerodrome. His first clearly-marked sensation, when in actual flight, will occur most likely when the pilot rises a little sharply, so as to gain altitude. Then the pupil will have a feeling one might liken to the ascent, in a motor-car, of a steep and suddenly-encountered hill; though in this case the hill is invisible, and there is no earth contact to be felt. This sensation of climbing is exhilarating; and when the pilot makes a reverse movement, descending towards the ground, the feeling is pleasant enough also, provided the dive is not too steep. The pupil's chief sensation, probably, will be that of the rush of wind which beats against him. Some people feel this much more than others. There is sometimes a feeling--it is no more than temporary--of inconvenience and of shock. The pupil feels as though his breathing was being interfered with seriously; as though the pressure was so great he could not expel air from his lungs. But this sensation, even when it is experienced, is short-lived. In a second flight, quite often, the novice finds that this oppression diminishes very perceptibly; and soon he does not notice it at all. Motoring experience proves useful here, particularly high-speed driving on a track. Some confusion is felt by the pupil, as a rule, and this is only natural, in regard to the pace at which the aeroplane travels through the air, and at the way in which the ground seems to be tearing away below. Occasionally, in a first flight, this impression of speed, and of height, produce in the pupil a sensation of physical discomfort; but it is one again which, in the majority of cases, is quickly overcome. A few balloon trips are a useful preliminary to flights in an aeroplane. They familiarise one in a pleasant way with the sensation of height, and accustom the eye also to the look of the ground, as it passes away below. While he is making his first flights with the instructor, and apart from analysing his sensations, the pupil will observe the lever movements made by the pilot in controlling the machine; and the fact that will impress itself upon him, as he watches these movements, is that they are not made roughly or spasmodically, but are almost invariably gentle. During these flights as a passenger, and after he has accustomed himself to the novelty of being in the air, the pupil will be allowed by the instructor to lean forward and place his hand on the control lever; and in this way, by actually following and feeling for himself the control actions the pilot makes, he will gain an idea of just the extent to which the lever must be moved, to gain any specific result in the flight of the machine. [Illustration: MOTOR AND OTHER GEAR--ANOTHER VIEW. _Photo by Topical Press Agency._ This shows the constructional unit that is formed, on a suitably strong framework of wood, by the engine, propeller, and fuel tank, and also by the seats for the pilot and passenger.] The next stage of tuition is that in which a pupil is allowed to handle a biplane alone, not in flight though but only in "rolling" practice on the ground--driving the machine to and fro across the aerodrome. The motor is adjusted so that, while it gives sufficient power to drive the machine on the ground and render the control surfaces effective, it will not permit the craft to rise into the air. This stage, a very necessary one, teaches the pupil, from his own unaided experience just what movements he must make with his levers to influence the control surface of the machine, and to maintain it, say, on a straight path while it runs across the ground. One of the discoveries he will make is that the biplane, if left to itself, shows a tendency to swerve a little to the left--the way the propeller is turning; but this inclination may be corrected, easily, by a movement of the rudder. The pupil learns also to accustom himself, while in this stage, to the engine controls which have been explained already; and he is not likely to be guilty of the error of one excitable novice who, while driving his machine back on the ground towards the sheds at an aerodrome, after his first experience in "rolling" became so confused, as he saw the buildings looming before him, that he lost his head completely and forgot to switch off his motor. The result was that the aeroplane, unchecked in its course, crashed into some railings in front of the sheds and stood on its head. Not much damage was done however, and the novice was unhurt. He seemed as surprised as anyone at what had happened, and confessed that, for the moment, his mind had been an utter blank. A pupil continues his practice in "rolling" till he can drive his machine to and fro across the aerodrome on a straight course, and with its tail raised off the ground; the latter action being obtained by the pupil by means of a suitable movement of the vertical lever which operates his elevating planes. Now comes the time when a pupil, taking the pilot's seat, and with the instructor sitting behind him--so as to be ready, if necessary, to correct any error the novice may make--begins his first short flights across the aerodrome. He rises only a few feet to begin with, and flies on a straight course, alighting each time before he turns, and running his machine round on the ground. He repeats this test until his instructor feels he is sufficiently expert to take the machine into the air alone. When this stage is reached, the instructor leaves his position behind the pupil, and the latter goes on with his practice till he can fly the length of the aerodrome alone, landing neatly and bringing his machine round on the ground, and then flying back again to his starting point. In the early days of flying schools, before a pupil went through any regular system of instruction, there were remarkable incidents in regard to these first flights. In one case a pupil, having bought his own aeroplane from the proprietors of a school, insisted on having installed in it a motor of exceptional power. When the time came for him to make his first flight alone, and he opened the throttle of this engine and it began to give its full power, the aeroplane ran only a short distance across the ground, and then leapt into the air. The engine was in charge of the machine, in fact, and not the pupil. Away above the aerodrome, and beyond its limits, in a strange, erratic flight, the biplane made its way. As the pupil struggled valiantly with his engine switch, which appeared to have become jammed, he made unconscious and jerky movements of his control levers. One moment the machine would ascend a little, the next it would approach nearer the ground; then it would swing either right or left. Those watching from the aerodrome held their breath. But with the luck of the beginner, a luck which is proverbial and sometimes amazing, the pupil managed at length to stop his motor and land without accident--though by no means gracefully--in an abrupt gliding descent. [Illustration: PUPIL AND INSTRUCTOR READY FOR A FLIGHT. _Photo by Topical Press Agency._ The pupil, occupying in this case the driving seat, has in his right hand the lever controlling the elevator and ailerons, while his feet are on the bar which operates the rudder. The instructor (in the passenger's seat) is demonstrating how, when necessary, he can place his hand on the control lever, above that of the pupil, and correct any error in manipulation of which the latter may be guilty.] Another story concerns one of those temperamentally reckless, happy-go-lucky men who, though providence seems to watch over them, are an anxiety nevertheless to their instructors. This pupil, breaking the rules of a school, flew out on one of his first flights beyond the limits of the aerodrome, disappearing indeed from the view of those near the sheds. Not far from the aerodrome lay a main road, with tramway-lines along it. A tram, with passengers on top, happened to be passing down the road; and it was to the astonishment of these passengers, and to their perturbation as well, that they observed an aeroplane in full flight, moving very low across a neighbouring field, and bearing down straight towards them. The machine passed, indeed, unpleasantly close above their heads, and then vanished as dramatically as it had appeared. Its pilot, as may be guessed, was the pupil who had disobeyed orders, and was now on a wild and erratic flight. Presently, after swerves and wanderings over the surrounding country, he was discerned making his way back towards the aerodrome, still flying unreasonably low. Some trees bordered one end of the aerodrome; and towards these, as though he meant to finish his exploit by charging into them, the novice was seen to be steering an undeviating course. Nearer he came to them, and still he did not turn either right or left. The instructor, and those gathered with him, made up their minds that nothing could avert an accident. But it happened that there was, between two of the trees, a space only large enough for an aeroplane to pass through. A skilled pilot, a man of experience, would not have cared to risk his machine in an endeavour to creep between those trees. But this pupil, a complete novice, steered boldly towards the opening and slipped through it with a precision that would have aroused the envy of an accomplished pilot. Then he landed on the aerodrome and climbed in leisurely fashion from his machine--"not having turned a hair," as the saying goes. The remarks of the instructor when he neared the machine, and began to unburden himself, do not appear to be on record, and no doubt this is as well. Having shown his ability to make a succession of straight flights, taking his machine into the air with precision and landing without awkwardness, the pupil finds himself faced next with the problem of turning while in the air. On this stage, however, he is not allowed to embark alone. The instructor takes his place again in the passenger's seat, so as to be ready to help the novice should he become confused, or find himself in any difficulty. Turns to the left are attempted first; and the reason is that, the propeller of the aeroplane revolving to the left--and the motor too if it is a rotary one--the machine has a tendency which is natural to turn in this direction. Half turns only are tried at first, the pupil landing before he has completed the movement. In making these first turns a pupil finds that, apart from his action with the rudder-bar, it is necessary to employ the ailerons slightly, so as to prevent the biplane from tilting sideways. The outer plane-ends of the machine have indeed, when a turn is being made, a natural tendency to "bank" as it is called, or tilt upward; the reason being that, as the machine swings round, these outer plane-ends, moving faster for the moment than the wing-tips on the inside of the turn, exercise a greater lift, and have an inclination to rise. An experienced aviator, having learned what is a safe "banking" angle, makes a deliberate use of this tendency when he is turning, and may on occasion even exaggerate it, to facilitate the swing of his machine on a very rapid turn, and to prevent it skidding outwards. But with the novice, engrossed completely as he is with the mere problem of getting his machine round in the air, "banking" is an art that must be deferred for awhile. It is perilously easy, for a beginner, to overstep the danger-line between a safe "bank" and a side-slip. [Illustration: PUPIL AND INSTRUCTOR IN FLIGHT (1). _Photo by Topical Press Agency._ A school biplane is seen just after it has left the ground, with the pupil at the control levers, and the instructor seated behind him--ready, if necessary, to correct any error the novice may make.] It is not long before the pupil can make a full left-hand turn; and then he goes on to perfect himself in this movement, flying alone now, and repeating the turn till he feels he can make it with confidence, and at a fair height. And now he comes to his final evolutions. Having mastered the left-hand turn, he proceeds to make one to the right. It used to be the contention--a contention that is now disputed--that in this movement, if the pupil employed his rudder-bar only, he would find the biplane showed an inclination to rise; a tendency due to the gyroscopic influence of the engine and propeller which--assuming a rotary engine is used--are now revolving in the opposite direction to that on which the machine is turned. What the pupil was recommended to do, in order to counteract this rising movement, was to tilt down his elevator a little, as he would in making a descent. When right-hand turns can be made with the same facility as those to the left, the pupil begins to combine the two without descending, making left turns and right turns, and so achieving in the air a series of figures of eight. He learns also to fly a little higher, thus preparing himself for one of his certificate tests. There are now certain very important rules which, in the navigation of his craft, he must accustom himself to bear constantly in mind. Should the engine of his machine, for example, betray any signs of failing, he must tilt down his elevator very promptly, and place his craft in a position for a descent. If he does not do this, and should the motor stop before he has his biplane at an angle for descent, the machine may lose speed so quickly, and its tail-planes show such a tendency to droop--owing to the lessening of pressure on their surfaces, consequent upon the failure of the motor--that there is a risk of the craft coming to a standstill in the air and then either falling tail-first, or beginning a side-slip that may bring it crashing to the ground. The pupil must learn also, and this again is important, not to force his machine round on a turn while it is climbing. If he does so the power absorbed in the ascent, combined with the resistance of the turn, may so reduce the speed of the machine that it threatens to become "stalled," or reach a standstill in the air, with the result that it either side-slips or falls tail-first. The procedure the pupil is taught to follow is this: when he leaves the ground he climbs a little, then he allows his machine to move straight ahead; then he proceeds to ascend again for a spell, repeating afterwards the horizontal flight. In this way he ascends by a series of steps, like climbing a succession of hills in a car; and his turns should be made only during the spells when he is flying horizontally. In this stage of his tuition, the pupil must learn also to make a vol-plané, or descent with his engine stopped. The essential point to be borne in mind, here, is that an aeroplane will continue in flight, and remain under control, even when it is no longer propelled by its engine. But what the aviator must do, should his engine stop through a breakdown, or should he himself switch it off, is to bring the force of gravity to his aid, and maintain the flying speed of his craft by directing it in a glide towards the ground. Provided he does this, and keeps his machine at such an inclination that it is moving at a sufficient speed through the air, he will find that the craft maintains its stability and that he has full command over its control surfaces, being able to turn, say, right or left, or either increase or slightly decrease the steepness of his descent. But all the time, of course, seeing that it is gravity alone which is giving him his flying speed, he is obliged to plane downward. [Illustration: PUPIL AND INSTRUCTOR IN FLIGHT (2). _Photo by Topical Press Agency._ This shows clearly how the instructor, from his seat behind the pupil, can lean forward and, by placing his hand on the control lever, check the novice in an error of manipulation.] A vital point to remember, when a pupil is handling a "pusher" type of biplane, is to incline the machine well downward, by a use of the elevator, before switching off the motor. Unless this is done, and if the machine is, say, at its normal horizontal angle when the engine is stopped, the sudden removal of pressure from the tail-planes of the craft, brought about by the absence of the wind-draught from the propeller, may cause the tail so to droop as to render inoperative any subsequent action of the elevator. When the tail droops, the main-planes are set at a steep angle to the air, and this has a slowing-up influence on the whole machine. It threatens therefore to stand still in the air; its controls become useless; and the pupil is faced probably with the danger of a side-slip. A story will illustrate this point; and it is one that has a special significance, seeing that the error which might have cost him his life was made by an aviator of experience. He had learned to fly on a monoplane, and had devoted his subsequent flying, for many months, to this one type of machine. Then he found himself associated with an enterprise in which a number of "pusher" biplanes were employed, and he decided that it would be useful for him to become accustomed to this type of machine. His flying experience of course helped him, and he soon found himself passing to and fro above the aerodrome, the biplane well in hand. Then he thought he would make a vol-plané, with his motor stopped, as he had been in the habit of doing in a monoplane. He switched off his engine without further thought, and moved his elevator to a position for the descent. But it was here that he made the mistake. In a monoplane, which has the weight of the engine and other gear well forward in the machine, the bow has a natural tendency to tilt down when the motor is cut off--particularly as the propeller-draught ceases to sweep under the sustaining planes. Therefore one can, in such a machine, switch off safely without first shifting the elevator, and getting the bow down as a preliminary. What the pilot had forgotten, for the moment, was the essential difference between monoplane and biplane. When he had switched off the engine in the biplane, and moved his elevator as he was accustomed to do, he found to his dismay that the machine failed to respond. Instead of pointing its bow down, indeed, it began to tilt rearward. Also, and this fact was noted by the airman with even more dismay, the craft lost forward speed so rapidly that it became uncontrollable. The next moment, the pilot helpless in his seat, the machine began a side-slip towards the ground. One sweep it made sideways, falling till it was not far short of the surface of the aerodrome. It paused an instant, then began a side-slip in the opposite direction. But here good fortune came to the pilot's aid. In this second swing, the machine being near the ground, it came in contact with the surface of the aerodrome before the "slip" had time to develop any high rate of speed. The biplane took the ground sideways, breaking its landing-chassis and damaging the plane-ends which came first in contact with the earth. But the pilot emerged from the wreckage unhurt. The accident was a lesson to him, though, as it was to others, and as it should be to all pupils. A machine must be in a gliding position before the engine is switched off. The art of the accomplished pilot, granted there is no reason for him to reach earth quickly, is to glide at as fine an angle as is possible, consistent of course with maintaining the speed of the machine through the air, and so preserving his command over its controls. A beautifully-timed, fine glide, the machine stealing down gracefully, and touching the aerodrome light as a feather, at a precise spot the airman has decided on even when he was several thousand feet high, is a delightful spectacle for the onlooker, and a keen pleasure also--from the point of view of his manipulative skill--to the aviator himself. But a pupil, at any rate in his first attempts, must not concern himself too much with any idea of a fine or graceful glide. It is his business to get to the ground safely, and not trouble too much whether his method is accomplished, or merely effective. Once with the bow of his machine down, and his motor switched off, it must be his concern to maintain the forward speed of his machine, which can be done only by holding it well on its dive. For the novice, if he attempts any fine or fancy gliding, there is the very real danger that, in his inexperience, he may lose forward speed to such an extent that his controls become inoperative, and his machine threatens to side-slip. One's ear should, apart from the inclination of the machine, and the sensation of the descent, help one materially in judging the speed of a glide. There is a "swish" that comes to the ear, now the engine is no longer making its clamour, which gives a guide to the pace of one's downward movement. Aviators who are skilled, and have done a large amount of flying, are able to judge with accuracy, by the ear alone and without the aid of a mechanical indicator, what their speed is as they pass through the air. [Illustration: PUPIL AND INSTRUCTOR IN FLIGHT (3). _Photo by Topical Press Agency._ Here the pupil is descending in a glide with his engine stopped, the cylinders of the rotary motor being clearly visible.] Having held his machine firmly on its glide, till it is quite near the surface of the aerodrome, the pupil has next to think of making a neat contact with the ground. The art here is, at a moment which must be gauged accurately, to check the descent of the machine by a movement of the elevator--to "flatten out," as the expression goes. If the movement is made neatly the craft should, when only a few feet from the ground, change from a descent into horizontal flight, and continue on this horizontal flight for a short distance, losing speed naturally each moment--seeing that there is no driving power behind it--and so losing altitude also through its decrease in speed, until its wheels come lightly in contact with the ground, and it runs forward and then stands still. What the novice may do, if he is not careful, is to "flatten out" when he is too high above the ground. The result is that the machine slows up till it stands still in the air, robbed of its speed, and then makes what is called a "pancake" landing: it descends vertically, that is to say, instead of making contact with the ground at a fine angle and with its planes still supporting it; and the effect of such a "pancake," if the machine comes down with any force, may be that the landing-chassis is damaged, or perhaps wrecked. But as a rule, remembering that he has careful instruction to guide him before he attempts a gliding descent, the pupil masters the art of landing without difficulty, and without mishap. Now, after repeating perhaps certain of his evolutions, at the discretion of his instructor, in order to make sure that he can accomplish them with ease, the pupil is ready for the tests which will give him his certificate of proficiency. CHAPTER VI THE TEST FLIGHTS The sport of aviation is controlled throughout the world, and flying tests and events of a competitive character are governed, by the International Aeronautical Federation. To the deliberations of this central authority are sent delegates from the Aero Clubs of various countries; and to these Aero Clubs, each in its respective country, falls the task of governing flight, according to the rules and decisions of the central authority. In Britain, controlling aviation in the same way that the Jockey Club controls the Turf, we have the Royal Aero Club of the United Kingdom; and it is this body, acting in its official capacity, which grants to each new aviator, after he has passed certain prescribed tests, a certificate which proclaims him a pilot of proved capacity, and without which it is impossible for him to take part in any contests held under the auspices of the Club. The certificate, which is of a convenient size for carrying in the pocket, contains a photograph of the pilot for purposes of identification, and specifies also the rules under which the certificate is issued and held. The theory of these tests, as imposed by the Club before it grants its certificates, is that the novice should--so far as is possible in one or two flights, made over a restricted area, and in a limited space of time--be called on to show that he has a full control over a machine in what may be called the normal conditions of flight. He is asked to ascend, for instance, and gain a fair flying altitude; then to make such evolutions as will demonstrate his command over the control surfaces of the machine; and finally to show that he can, with his motor switched off, descend accurately in a vol-plané, and bring his machine to a halt within a specified distance of a mark. The tests are set forth, officially, as follows:-- _A and B._ Two distance flights, consisting of at least 5 kilometres (3 miles 185 yards) each in a closed circuit, without touching the ground; the distance to be measured as described below. _C._ One altitude flight, during which a height of at least 100 metres (328 feet) above the point of departure must be attained; the descent to be made from that height with the motor cut off. The landing must be made in view of the observers, without re-starting the motor. The rules drafted by the Club to govern these flights are set forth herewith:-- The candidate must be alone in the aircraft during the tests. The course on which the aviator accomplishes tests A and B must be marked out by two posts situated not more than 500 metres (547 yards) apart. The turns round the posts must be made alternately to the right and to the left, so that the flights will consist of an uninterrupted series of figures of eight. The distance flown will be reckoned as if in a straight line between the two posts. The alighting after the two distance flights in tests A and B shall be made:-- (_a_) By stopping the motor at or before the moment of touching the ground. (_b_) By bringing the aircraft to rest not more than 50 metres (164 feet) from a point indicated previously to the candidate. All alightings must be made in a normal manner, and the observers must report any irregularity. These flights as specified to-day, though they present no difficulty to the pupil who has been well trained, are more stringent than they were in the first scheme of tests as prescribed by the Club, and as enforced for several years. In those early rules the distances were the same as they are to-day, but in the altitude flight the height required was only 50 metres (164 feet)--just half the height specified to-day. It was not laid down, either, in the first rules, that the engine should be stopped in this altitude flight when at the maximum height, and that the descent should be made in a complete vol-plané, without once re-starting the motor. As originally framed, indeed, the rule as to the control of the engine in this altitude test was the same as in regard to the distance flights--_i.e._, that it should be stopped "at or before the moment of touching the ground." What the present rule means, in this respect, is that the pupil must be really proficient at making a vol-plané, without any aid at all from his engine, before he can hope to pass the test; and such a proved skill--say in the making of his first cross-country flight, should his engine fail suddenly--may spell the difference between a safe or a dangerous landing. The test flights for the certificate, undertaken only in such weather conditions as the pupil's instructor may think suitable, are watched by official observers appointed by the Royal Aero Club. It is the business of these observers, when the prescribed flights have been made, to send in a written report concerning them to the Club; and acting on this report, after it has been considered and shown to be in order, the Club issues to the pupil his numbered certificate. With the successful passing of his tests the pupil's tuition is at an end. He is regarded no longer as a novice, but as a qualified pilot. CHAPTER VII PERILS OF THE AIR There are people, very many people, who still regard flying as an undertaking of an unreasonable peril, essayed mainly by those who are in quest of money, notoriety, or sensation at any price. Such people--still to be met with--have one mental picture, and one only, of the flight of an aeroplane. They imagine a man in the air--and this mere idea of altitude makes them shudder; and they picture this man in a frail apparatus of wood and wire, capable of breaking to pieces at any moment; or even if it does not break, needing an incessant movement of levers to maintain it in a safe equilibrium; while they reckon also that, should the engine of the machine suffer any breakdown, the craft will drop to earth like a stone. Prejudice dies hard; harder no doubt in England than in other countries. There are still people, not few of them but many, who would be ready to declare, offhand, that one aeroplane flight in six ends in a disaster. It is a truism, but one that has a peculiar truth in aviation, to say that history repeats itself. To-day we find large numbers of people who still cherish the opinion that--save perhaps when on service in war--it is nothing less than criminal foolishness for men to ascend in aeroplanes. That attitude of mind persists; the growing safety of flight has not affected it to any appreciable degree. But those eager for the progress of aviation need not despair, or imagine that their particular industry is being treated with any exceptional disapprobation. They have only to look back a little in our history, no great distance, and read of the receptions that were accorded the first pioneers of our railways. Public meetings of protest have not been held to condemn aviation; yet they were frequent in the days when the first railways were projected. Vast indignation was indeed aroused; it was declared to be against all reason, and a matter of appalling risk, that people should be asked to travel from place to place in such "engines of destruction." But the railways managed to survive this storm. They were placed here and there about the country; they were improved rapidly; and it would be hard, to-day, to find a safer place than the compartment of a railway train. Motor-cars, when their turn came, had to go through a similar ordeal. There was the same indignation, the same chorus of protest; and when the first of the pioneers, greatly daring, began actually to drive their cars on the public highway, there were people who believed, and who declared forcibly, that to permit such machines on our roads was the crime of the century. Had not these pioneers struggled valiantly, sparing neither time nor money, it is possible that the motor-car might have been driven from the highway. But here again progress, though it was retarded, could not be checked. The motor-car triumphed. It grew rapidly more reliable, more silent, more pleasing to the eye; and to-day it glides in thousands along our roads, a pleasure to those who occupy it, a nuisance neither to pedestrians nor to other wheeled traffic; more under control when it is well driven, and more ready to stop quickly when required, than any horsed vehicle which it may have replaced. At one time the papers were full of such headlines as: "Another Motor-car Accident." Each small mishap received prominent attention: and to the majority of people it seemed the wildest folly to travel in such vehicles. Yet to-day--such is progress--these same people ride in a motor-car, or a motor-cab, quite as a matter of course and without a thought of risk. When one discusses flying and its dangers, it is essential to maintain an accurate sense of proportion. In the very earliest days, for instance, it must be realised that the few men who then flew--they could be numbered on the fingers of one hand--exercised the greatest caution. They did not fly in high winds; they treated the air, realising its unknown perils, with a very great and a very commendable respect. Thus it was that thousands of miles were flown, even with the crudest of these early machines, and with motors that were constantly giving trouble, without serious accident. But after this, and very quickly, the number of airmen grew. New aviators appeared every day; contests were organised extensively; there were large sums of money to be won, provided that one pilot could excel another. And the spirit of caution was abandoned. Even while they were still using purely experimental machines--craft of which neither the stability nor the structural strength had been tested adequately--there grew a tendency among airmen to fly in higher winds, to subject their machines to greater strains, and to attempt dangerous manoeuvres so as to please the crowds who paid to see them fly. It was not surprising, therefore, that flying entered upon an era of accidents. Such disasters were inevitable--inevitable, that is to say, in view of the tendencies that then prevailed; though it is a melancholy reflection that, had men been content to go ahead with the same slow sureness of the pioneers, many of those lives which were lost could have been saved. To the public, not aware exactly of all that was going on, it appeared as though the navigation of the air, instead of growing safer, was becoming more dangerous. There were suggestions, indeed, made quite seriously and in good faith, that these endeavours to fly should cease; that the law should step in, and prevent any more men from risking their lives. What people failed to realise, when they adopted this view, was that instead of one or two men flying there were now hundreds who navigated the air; that flights in large numbers were being made daily; that thousands of miles instead of hundreds were being traversed by air--and often under conditions the pioneers would have considered far too dangerous. These facts, had they been realised, would have shown people what was actually the true state of affairs; that, though accidents seemed numerous, and were indeed more frequent than they had been in the earliest days of flying, they were as a matter of proportion, reckoning the greater number of men who were flying, and the thousands of miles which were flown, growing steadily less frequent. There was this important fact to be reckoned with also. Each accident that happened taught its lesson, and so made for future safety. A considerable number of those early accidents can, for instance, be traced to some structural weakness in a machine. The need in an aircraft then, as now, was lightness; and in those days designers and builders, owing purely to their inexperience, had not learned the art, as they have to-day, of combining lightness with strength. So it was that, as more powerful motors began to be fitted to aeroplanes, and greater speeds were attained, it happened sometimes, when a machine was being driven fast through a wind, that a plane would collapse, and send the machine crashing to the ground; or in making a dive, perhaps, either of necessity or to show his skill, a pilot would subject his machine to such a strain that some part of it would break. From such disasters as a rule, greatly to be regretted though they were, the industry emerged so much the wiser. The strength of machines was increased; the engines which drove them were rendered more reliable; and gradually too, though none too rapidly, the airmen who piloted them grew in knowledge and skill. But all this time, while flying was being made more safe, there were accidents frequently for the papers to report; and this was due entirely to the fact that there were now thousands of men flying, where previously there had been fifties and hundreds. The public could not realise how rapidly the number of airmen had grown; that practically every day, at aerodromes scattered over Europe, flights were so frequent that they were becoming a commonplace. It was in 1912, as one of its many services to aviation that the Aero Club of France was able to show, by means of statistics which could not be questioned, that for every fatality which had occurred in France, during that particular year, a distance of nearly 100,000 miles had been flown in safety. The cause of many of the early accidents was, as we have suggested, the breakage of some part of a machine while in flight. In an analysis for instance of thirty-two such disasters, it was shown that fourteen were due to the collapse of sustaining planes, control-surfaces, or some other vital part of a machine. And this risk of breakage in the air was increased, in many cases, by the building of experimental machines by men who had no qualifications for their task, and who erred only too frequently, in their desire to attain lightness, on the side of a lack, rather than an excess, of structural strength. There are many cases, unfortunately, that might be cited; but one may be sufficient here. A man with an idea for a light type of biplane, a machine designed mainly for speed, had an experimental craft built--this was in the pioneer days of 1909--and insisted on fitting to it a motor of considerable power. It was pointed out to him that his construction was not sufficiently strong, in view of the speed at which his machine would pass through the air. But he was of the quiet, determined, self-opinionated type, who pursued his own way and said little. He did not strengthen his constructional, and he began a series of flying tests. In the first of these, which were short, the planes stood up to their work, and the fears of the critics seemed groundless. But a day came when, venturing to some height, the aviator encountered a strong and gusty wind; whereupon one of his main-planes broke, and he fell to his death. As a contrast to this tragedy, and a welcome one, there is a humorous story, that is true, told of one experimenter. His knowledge of construction was small, but what he lacked in this respect he made up for in confidence; and he built a monoplane. This was in the days just after the cross-Channel flight, and experimenters all over the world were building monoplanes, some of them machines of the weirdest description. The craft built by this enthusiast seemed all right in its appearance; nothing had been spared, for instance, in the way of varnish. When wheeled into the sun, for its first rolling test under power, it looked an imposing piece of work. Friends were in attendance, photographers also; and the would-be aviator was in faultless flying gear. Mounting a ladder, which had been placed beside the machine, he allowed his weight to bear upon the fusilage, and proceeded to settle himself in his seat. But he, and the onlookers, were startled as he did so by an ominous cracking of wood. It grew louder; something serious and very unexpected was happening to the machine. As a matter of fact, and just as it stood there without having moved a yard, the whole of the flimsy structure parted in the middle, and the machine settled down ignominiously upon the ground, its back broken, and with the discomfited inventor struggling in the _débris_. It was far from easy, in the early days, for even an expert constructor to calculate the strains encountered under various conditions of flight. In wind pressure, under certain states of the air, there are dangerous fluctuations--fluctuations which, even with the knowledge we possess to-day, and this is far from meagre, exhibit phenomena concerning which much more information is required. Machines have collapsed suddenly, while flying on a day when the wind has been uncertain, and have done so in a way which has suggested that they had encountered, suddenly, a gust of an altogether abnormal strength. Occasionally, though research work in this field is extremely difficult, it has been possible to gain data as to the existence of conditions, prevalent as a rule over a small area, which would spell grave risk for any aeroplane which encountered them. There is a strange case, verified beyond question, which occurred during some tests with man-lifting kites at Farnborough. These kites are strongly built, and withstand as a rule extremely high winds. On this particular day a kite, when it had reached a certain altitude, was seen to crumple up suddenly. The wind did not seem specially strong--not at any rate on the ground; and there appeared no reason for the breakage of the kite. Another was sent up; but the same thing happened, and at the same altitude. Then the officer who was in charge of the kites sent for a superior. A third kite was flown to see what would happen. This one broke exactly as the others had done, and at just the same height--about five hundred feet. Precise data could not be gained as to this phenomenon; but the breaking of these kites--which had withstood extremely high pressure in previous tests--was reckoned to be due to the fact that, when they reached a certain point in the air, they were subjected to the violent strain of a sudden and complete change in the direction of the wind. To the pilot of an aeroplane, entering without warning some such area of danger, the result might naturally be serious in the extreme. The air has been, and is still, an uncharted sea. It does not flow with uniformity over the surface of the earth. It is a constantly disturbed element, and one that has the disadvantage of being invisible. An aviator cannot see the dangerous currents and eddies into which he may be steering his craft; and so it was not surprising, in those days when aircraft were frailer than they should have been, and cross-country flights were first being made, that machines broke often while in flight and that the airman's enemy, the wind, claimed many victims. Wind fluctuations that are dangerous, those which possess for one reason or another an abnormal strength, are encountered frequently when a pilot is fairly near the earth; and his peril is all the greater in consequence. On a windy day, one on which there are heavy gusts followed by comparative lulls, it is when he is close to the ground, either in ascending or before alighting, that a pilot has most to fear. If he is well aloft, with plenty of air space beneath him, and particularly if he has a machine that is inherently stable, he has little to fear from the wind; save, perhaps, should his engine fail him, or should he find--as has been the case in war flying--that the force of the wind, blowing heavily against him, and reducing the speed of his machine, has prevented him from regaining his own lines before his petrol has become exhausted. The modern aeroplane, when its engine-power is ample, and it is at a suitable altitude, can wage battle successfully even with a gale. But it must rise from the earth when it begins a flight, and return to earth again when its journey is done; and here, in the areas of wind that are disturbed by hills, woods, and contours of the land, there are often grave dangers. The wind at these low altitudes blows flukily. Its direction may be affected, for instance, owing to the influence of a hill or ridge. A side gust, blowing powerfully and unexpectedly against a machine, just as it is nearing the ground before alighting, may cause it to tilt to such an angle that it begins a side-slip. If the craft was sufficiently high in the air, when this happened, the pilot would be able, probably, to convert the side-slip into a dive, and the dive into a renewal of his normal flight. But if such a side-slip begins near the ground, and there is an insufficient amount of clear space below the machine, it may strike the ground in its fall, and become a wreck, before there is time for the pilot, or for the machine itself, to exercise a righting influence. The fact that a craft may be forced temporarily from its equilibrium, say by a side-slip, is known now to represent no great risk for the airman, granted always that he has the advantage of altitude. The machine, in such circumstances, falls a certain distance. This is inevitable, and for the reason that it must regain forward speed--which it has lost temporarily in its side-slip--before its own inherent stability can become effective, or its pilot regain influence over his controls. And it is this unavoidable descent, this short period during which the machine is recovering its momentum, and during which the pilot has no power of control, that represents in a heavy wind the moments of peril, should a pilot enter an area of disturbance just as he nears the ground. An aeroplane, when it sets out to fly in bad weather, may be likened to a boat that is being launched from a beach upon a rough and stormy sea. It is the waves close inshore, which may raise his craft only to dash it to destruction, that the boatman has chiefly to fear; and for the aviator, when he leaves the land and embarks upon the aerial sea, or when he returns again from this element and must make his contact with the earth, there lurks a risk that, caught suddenly by an air wave, and with insufficient space beneath his machine, he may be forced into a damaging impact with the ground. But the skill of designers and constructors, to say nothing of the growing experience of aviators, is working constantly towards a greater safety. Of the risk attached to engine failure, when he is piloting a craft fitted with only one motor, an airman is reminded frequently, not only from his own experience, but from that of other flyers. With the aeroplane engine, even with types that have gained a high average of reliability, there are many possibilities of a slight mishap--each of them sufficient, for the moment, to put an engine out of action--that the pilot who is flying across country must, all the time he is in the air, have at the back of his mind the thought that at any moment, and perhaps without any warning, he may find that his motive power has gone. A magneto may fail temporarily; an ignition wire or a valve spring break. The aeroplane engine of to-day is, of course, an infinitely more reliable piece of apparatus than it was in those early days when Henry Farman, working with extraordinary patience at Issy-les-Moulineaux, was endeavouring--and for a long time without success--to make the motor in his Voisin biplane run for five consecutive minutes without breakdown. The war has shown us, and under working conditions which have been exceptionally trying, how reliable the aero-motor has become. But until duplicate plants have been perfected, and more than one motor is fitted to aircraft as a matter of course, there must always be this risk of failure. In the mere stoppage of a motor no great danger is implied. The pilot must descend; that is all. His power gone, he must glide earthward. But where the risk does lie, in engine failure, is that it may occur at a moment when the airman is in such a position, either above dangerous country or while over the sea, that he cannot during his glide reach a place of safety. A study of flying will show how awkward, and how perilous on many occasions, has been the stoppage of a motor while a machine is in the air. Two historic instances, though they did not, fortunately, end in a loss of the pilot's life, were the compulsory descents into the Channel made by the late Mr. Hubert Latham, during his attempts, in 1909, to fly from Calais to Dover. In both these cases--once when only a few miles from the French shore, and on the second occasion when the aeroplane was quite near its destination--the motor of the Antoinette monoplane failed suddenly, and the aviator could do nothing but plane down into the water. On the first occasion he alighted neatly, suffering no injury, and being rescued by a torpedo boat; but in the second descent, striking the water hard, he was thrown forward in his seat and his head injured by a strut. Less fortunate, in a case of presumed engine failure that will become historic, was Mr. Gustave Hamel. Eager to reach Hendon, so as to take part in the Aerial Derby on May 23rd, 1914, his great experience of Channel flying induced him to risk the crossing with a motor which, on his flight from Paris to the coast, had not been running well. His monoplane was a fast machine, and the flight across Channel would have taken him less than half an hour. But at some point during the crossing, it seems obvious, his engine failed him, and he was unable to prolong his glide either to gain the shore, or the vicinity of a passing ship. His monoplane was never recovered; but the body of the aviator--whose loss was mourned throughout the flying world and by the general public as well--was discovered by some fishermen while cruising off the French coast, and identified by means of a map, clothing, and an inflated motor-cycle tyre; the last-named being carried by the airman round his body to act as an improvised life-belt. Engine failure, though a fruitful cause of minor accidents, and of the breakage of machines, has led to few fatalities; and this has been due very largely to the fact that, though machines have descended under dangerous circumstances, and have been wrecked in a manner that would appear almost certain to kill their occupants, the pilots and passengers have, as a matter of fact, escaped often with no more than a shock or bruises. An aeroplane does not strike the ground with the impact of a hard, unyielding structure. It is essentially frail in its construction; and this frailness, though it spells destruction for the machine in a bad descent, provides at the same time an element of safety for its crew. Take the case for instance of a machine falling sideways, and striking the ground with one plane or planes. These planes, built of nothing stronger as a rule than wood, crumple under the impact. But in their collapse, which is telescopic and to a certain extent gradual, a large part of the shock is absorbed. By the time the fusilage which contains the pilot touches ground, the full force of the impact is gone. And it is the same, often, if a machine makes a bad landing, say on awkward ground, and strikes heavily bow-first. Granted that the occupants of the machine are well-placed, and prevented by retaining belts from being flung from the machine, they should escape injury from the fact that there is so much to be broken, in the way of landing-gear and other parts, before the shock of the impact can reach them in their seats. Had it not been for the capacity of the aeroplane to alight in awkward places without injury to its pilot, many lives might have been lost through descents in which motors have failed. Aviators have been obliged to land in most unsuitable places: on the roofs of houses, for instance, in small gardens, and frequently on the tops of trees. If he finds his engine fail him when he is over a wood or forest, and there is no chance save to descend upon the trees, a skilled pilot may save himself as a rule from injury. Planing down, till he is just above the tree-tops, he will then check suddenly, by a movement of his elevator, the forward speed of his machine. The craft will come to a standstill in the air; then, the support gone from its planes owing to the loss of forward speed, it will sink down almost vertically, and with very little violence, on to the tops of the trees. The machine itself will naturally be damaged, seeing that boughs will pierce its wings in many places, and that one or more of its planes may possibly collapse. But the net result of such a landing--and this is the point which is important for the pilot--is that the machine will be caught up and suspended on the trees, making a comparatively light and gradual contact, instead of there being any risk of its driving through the trees and making a heavy impact with the ground. Humour, sometimes, may be extracted from such a predicament as engine failure, though it needs an aviator with a very deeply ingrained sense of humour to do so. The story is told, however, of a pilot who, flying across difficult country with a passenger, found that his motor failed--as they often will--just at a moment when there seemed no possible landing-point below. Looking over the side of his machine, and glancing quickly here and there, the aviator saw no alternative but to bring his craft down in an orchard that lay below. Pointing downward, to acquaint his passenger with their unpleasant situation, and to call his attention also to the orchard, the pilot said with a smile: "I hope you're fond of apples!" There is a risk in engine failure which has been emphasised more than once; and it is that which may attend the pilot who, while prolonging a glide in order to reach some landing-point, may be struck by a gust, or enter some area of disturbed wind, just before he reaches the ground and while his machine, moving slowly, is not in a position to respond effectually to its controls. In one case an aviator, struggling back towards the aerodrome with a motor which was not giving its power, found that it stopped suddenly when he was not far from a wood. Beyond the wood, which stood on a ridge, there was a stretch of grassland. Endeavouring to reach this promised landing-point, and holding his machine on a long glide, the airman came across above the trees. He had almost reached his goal when his machine entered a sudden down-current of wind--occasioned, no doubt, by the proximity of the trees and ridge. Caught by this eddy, with no motive power to help him and very little speed on his machine, the pilot could not check its sudden dive; and the craft struck ground so heavily that both he and his passenger were killed. We have mentioned previously, as a fruitful cause of accident, that structural weakness of machines which has led, when conditions have been unfavourable, to a sudden collapse in the air. But apart from weakness in construction, and notably in accidents with early-type machines, there was the risk attached to mistakes in design, which produced machines which were unstable under certain conditions--and the dangers also which were due to inefficient controlling surfaces. It was no uncommon thing, in pioneer days, for a machine to be built which would not respond adequately to its elevator or rudder; though this unpleasant fact might not be discovered by the pilot until he was actually in flight, and perhaps at some distance from the earth. In one case, which is authenticated, a two-seated monoplane of a new type was tested at first in a series of straight flights, and found to be promising in its behaviour. A skilled pilot then took charge of it, and, carrying a passenger, proceeded to some more ambitious flights. Steering the machine away across the aerodrome, and flying at a low elevation, he approached a belt of woods. The machine was too near the ground to pass over the tops of the trees; so the aviator decided to make a turn, and fly parallel with the wood. But when he put his rudder over, so as to bring the machine round in a half-circle, he found to his dismay that there was no response. In the design of the machine, as it was found afterwards, the rudder had been made too small: it would not steer the machine at all. In the little space that was left him, and to avoid crashing into the trees, the pilot had to bring his craft to earth in such an abrupt dive that it was wrecked completely. He and the passenger, though, escaped unhurt. Carelessness has, fairly frequently, played its part in aeroplane disasters. Sometimes a pilot has been careless, or perhaps in a hurry, and has failed to locate some defect which, had it been seen and attended to, would have saved a disaster when a machine was in flight. Such inattention, which is sufficiently dangerous in the handling of any piece of mechanism, is deadly in its peril when those who are guilty of it navigate the air. A man who brings out a machine time after time, and ascends without examining it carefully, is adding vastly to the risks that may attend his flight; and the same remark will apply to the carelessness of mechanics; though as a class, in view of the arduous nature of their work, and of the long hours they have frequently to be on duty, with no more than hasty intervals for rest, their average of care and accuracy is very high. But there have been cases--mostly in the past though--in which a machine has developed a structural defect, or some defect say in its control gear, which ought to have been observed by its mechanics, but which has not been so detected, and has led to a catastrophe in flight. With machines built lightly, and subjected to heavy strains when at high speeds, it is vital that the inspection of such craft, that the examination of every detail of them, should be carried out in a spirit of the greatest care. The fraying through of a control wire, unnoticed by those in charge of a machine, has been sufficient to cause a disaster; while carelessness in overhauling a motor, a task of supreme importance, seeing that its engine is the heart of an aeroplane, has been another cause of accident. It is vital that, when an airman ascends, both his machine and his motor should be in perfect working trim. He himself, before he flies, and after his aeroplane has been wheeled from its shed, should make it a habit to look over the machine, so as to impose his own personal check upon the work his mechanics have done. Even when every care has been taken, and a machine ascends in perfect trim, there is the human factor, represented by the pilot, which must be considered always in a study of aeroplane accidents. There is often, when a catastrophe seems imminent, a choice of things that may be done. If an engine fails, for instance, under awkward circumstances, the pilot may have, say, three courses open to him in regard to his descent. Two may spell disaster and the third safety. It is here that the innate judgment of a pilot, combined with his experience, will tell its tale. But this personal element in flying, and particularly in regard to an accident, is often a very difficult one for which to make allowances. The whole problem of aeroplane disasters is, to the analyst, one of unusual complexity. Take for example the case of a pilot who is flying alone in his machine, and at an altitude of several thousand feet. Suddenly something happens; the machine is seen to fall and the pilot is killed. Experts come to examine the aircraft, but it is wrecked so completely that little which is reliable can be gathered from any inspection; while the man who could explain what has happened--the pilot of the machine--is dead. The statements of eyewitnesses, when taken on such occasions, are often misleading. One person heard a crash, and saw something fall away from the machine. Another declares the engine stopped suddenly and that the machine "fell like a stone." Another says he is sure he saw one of the wings fold upwards and the machine swing and fall. And so on. It is extremely difficult, even for a technical eye-witness, to be sure of what he sees when things happen quickly and at a distance from him; while the statements of non-technical people, who are not trained in observation, are generally so unreliable as to be useless. It has happened often therefore, far too often, in aeroplane fatalities that have happened from time to time, that the cause of such accidents has, even after the most careful investigation, had to be written down a mystery. But in more than a few cases, though the evidence has been far from conclusive, it has been considered that a pilot has been guilty of some error of judgment. There were puzzling instances, notably in the early days of flying, when airmen began first to make cross-country flights, of engines being heard to fail suddenly, and machines seen to fall to destruction. That engines should break down was not surprising; they were doing so constantly; but there was no reason why, even if they did fail, a machine should fall helplessly instead of gliding. But what was thought to have happened, in more than one of these cases, was that the pilot, through an error of judgment, had failed to get down the bow of his machine when his motor gave signs of stopping. The craft concerned were, it should be mentioned, "pusher" biplanes; and the same rule applied to them, in cases of engine failure, as has been explained in a previous chapter, and as is emphasised nowadays in the instruction of the novice. But in those days the beginner had frequently to learn, not from wise tuition, but from bitter experience; and he was lucky, often, if he learned his lesson and still retained his life. On certain early-type biplanes, for instance, machines with large tail-planes, and engined as a rule by a motor which was giving less than its proper amount of power, it was most dangerous for a pilot if, on observing any signs of failing in his engine, he sought to fly on in the hope that the motor would "pick up" again, and continue its work. Directly there was a tendency of the motor to miss-fire, or lessen in the number of its revolutions per minute, the consequent reduction of the propeller draught, as it acted on the tail of the machine, would cause this tail to droop, and the machine to assume very quickly a dangerous position. And when once it began to get tail-down, as pilots found to their cost, there was nothing to be done. The machine lost what little forward speed it had, and either fell tail-first, or slipped down sideways. Such risks as these, which were very real, were rendered worse owing to the fact that, in much of the cross country flying of the early days, pilots flew too low. They lacked the confidence of those who followed them, and were too prone to hug the earth, instead of attaining altitude. It was not realised clearly then, as it is now, that in height lies safety. And so when a machine lost headway through engine failure, and was not put quickly enough into a glide, it happened often that it had come in contact with the earth, and had been wrecked, before there was any chance for the pilot to regain control, or for the machine itself to exhaust its side-slip, and come back to anything like a normal position. But the failure of the human factor in flying, the lack of skill of a pilot that may lead to disaster, is shown by statistics to play no more than a small part, when accidents are studied in numbers and in detail. Some time before the war, in an analysis of the accidents that had befallen aviators in France--accidents concerning which there was adequate data--it was shown that only 15 per cent. of them could be attributed to a failure in judgment or skill on the part of the pilot. Apart from errors, however, in what may be called legitimate piloting, there have been regrettable accidents due to trick or fancy flying. Putting a machine through a series of evolutions, to interest and amuse spectators, is not of course in itself to be condemned. In such flying, and notably for instance in "looping the loop," facts were learnt concerning the navigation of the air, and as to the apparently hopeless positions from which an aeroplane would extricate itself, which were of very high value, from both a scientific and practical standpoint. Public interest in aviation was increased also by such displays; and it is very necessary that there should be public interest in flying, seeing that it is the public which is asked to pay for the development of our air-fleets. But the man who undertakes exhibition flying needs not only to be a highly-skilled pilot, but a man also of an exceptional temperament--a man whose familiarity with the air never leads him into a contempt for its hidden dangers; a man who will not, even though he is called on to repeat a feat time after time, abate in any way the precautions which may be necessary for his safety. In looping the loop, for instance, or in upside-down flying, it is necessary always that the aeroplane should be at a certain minimum height above the ground. Then, should anything unexpected happen, and the pilot lose command temporarily over his machine, he knows he has a certain distance which he may fall, before striking the ground; and during this fall the natural stability of his machine, aided by his own operation of the guiding surfaces, may bring it back again within control. But if he has been tempted to fly too near the ground, and has ignored for the moment this vital precaution, and if something happens for which he is not prepared, then the impact may come before he can do anything to save himself. In the early days of flying, when aviators attempted an acrobatic feat, they ran a far heavier risk than would be the case to-day; and for the simple reason that their machines, not having a strength sufficient to withstand any abnormal stresses, were likely to collapse in the air if they were made to dive too rapidly, or placed suddenly at any angle which threw a heavy strain on their planes. A machine for exhibition flying needs to be constructed specially; but this was not realised till accidents had taught their lesson. It is a regrettable fact, one which emerges directly from a study of aeroplane accidents, that many of them might have been avoided had men been content to follow warily in the footsteps of the pioneers, and not run heavy risks till they themselves, and the machines they controlled, had been prepared, by a long period of steady flying, to meet such greater dangers. The first men who flew realised fully the risks they ran. But when flying became more general, and men found machines ready to their hands, machines which it was a simple matter to learn to fly, this early spirit of caution was forsaken, and feats were attempted which brought fatalities in their train, and which seemed to emphasise the risks of aviation, and did it the very bad service that they fixed in the public mind a notion of its dangers, and prevented men from coming forward to take up flying as a sport. CHAPTER VIII FACTORS THAT MAKE FOR SAFETY It has been calculated that nearly half the aeroplane disasters of the early days were due to a structural weakness in machines, or to mistakes either in their design, or in such details as the position, shape, and size of their surfaces. To-day, thanks to science, and to the growing skill and experience of aeroplane designers and constructors, this risk of the collapse of a machine in the air, or of its failure to respond to its controls at some critical moment through an error in design, has been to a large extent eliminated. That such risks should be eliminated wholly is, as yet, too much to expect. One of the factors making for safety has been the steady growth in the general efficiency of aircraft: in the curve of their wings which, as a result largely of scientific research, has been made to yield a greater lift for a given surface and to offer a minimum of resistance to their passage through the air; in the power and reliability of their engines; in the efficiency of their propellers; and in the shaping of the fusilage of a machine, and in the placing and "stream-lining" of such parts as meet the air, so as to reduce the head resistance which is encountered at high speeds. Such gains in efficiency, which give constructors more latitude in the placing of weight and strength where experience show they are needed, have gone far to produce an airworthy machine. In the old days, when machines were inefficient, a few revolutions more or less per minute in the running of an engine meant all the difference between an ascent and merely passing along the ground. But nowadays, through the all-round increase in efficiency that has been obtained, a machine will still fly upon its course without losing altitude, and respond to its controls, even should the number of revolutions per minute of its engine be reduced considerably. When given a greater efficiency in lifting surfaces and power-plants--and profiting also from the lessons that had been learnt in the piloting of machines--constructors were able to devote their attention, and to do so with certainty instead of in a haphazard way, to the provision of factors of safety when a craft was in flight. With a machine of any given type, if driven through the air at a certain speed, it is possible to estimate with accuracy what the normal strains will be to which it is subjected. But even if such data are obtained, and the machine given the strength indicated, this factor of safety is insufficient. It is not so much the normal strains, as those which are abnormal, that must be guarded against in flight. A high-speed machine, if piloted on a day when the air is turbulent, may be subjected to extraordinarily heavy strains; rising many feet in the air one moment, falling again the next, and being met suddenly by vicious gusts of wind--in much the same way that a fast-moving ship, when fighting its way through a rough sea, is beaten and buffeted by the waves. Air waves have not of course the weight, when they deliver a blow, that lies behind a mass of water; but that these wind-waves attain sometimes an abnormal speed, and have a tremendous power of destruction, is shown in the havoc that is caused by hurricanes. It seems astonishing to many people that such a frail machine as the aeroplane, with its outspread wings containing nothing stronger often than wooden spars and ribs, covered by a cotton fabric, should be capable of being driven through the air at such a speed, say, as 100 miles an hour, encountering not only the pressure of the air, but resisting also the fluctuations to which it may be subjected. But, underlying the lightness and apparent frailty of such a wing, when one sees it in the workshop in its skeleton form, before it has been clothed in fabric, there is a skill in construction, and an experience in the choice, selection, and working of woods, that produces a structure which, for all its fragile appearance, is amazingly strong. And the same applies, nowadays, to all the other parts of an aeroplane. That it should have taken years to gain such strength, and to reduce so largely the risk of breakage, is not in itself surprising. Men had to devise new methods in construction--always with the knowledge that weight must be saved--and to create new factors of safety, before they could build an airworthy craft. To-day, when a man flies, he need have no lurking fear, as had the pioneers, that his craft may break in the air. Even when it is driven through a gale, plunging in the rushes of the wind, yet held straining to its task by the power of its motor, the modern aeroplane can be relied upon; and not in one detail of its construction, but in every part. Experience, the researches of science, and the growing skill with which aircraft are built, stand between the airman and many of his previous dangers. The aeroplane to-day, one of the structural triumphs of the world in its lightness and its strength, has a factor of safety which is sufficient to meet, and to withstand, not merely ordinary strains, but any such abnormal stresses as it may encounter--and which may be many times greater than the strains of normal flight. The aviator knows also that his engine, as it gives him power to combat successfully his treacherous enemy, the wind, represents the fruit of many tests and of many failures, and of the spending of hundreds of thousands of pounds. Many of its defects have revealed themselves, and been rectified; it is no longer light where it should have weight of metal, nor weak where it should be strong. So far as any piece of mechanism can be made reliable, consisting as it does of a large number of delicate parts, operating at high speed, the aeroplane motor has been made reliable. But, so long as one motor is used, there must always, as we have said, remain a risk of breakdown. It is for this reason that, thanks largely to the stimulus of the war--which has created a practical demand for such machines--aeroplanes are now being built, and flown with success, which are fitted with duplicate motors. With such machines, which give us a first insight as to the aircraft of the future, engine failure begins to lose its perils--particularly in regard to war. More than once during the great campaign, when flying a single-engine machine, an aviator has found his motor fail him, and has been obliged to land on hostile soil; with the result that he has been made prisoner. But with dual-engine machines it has been found that, when one motor has failed mechanically, or has been put out of action by shrapnel, the remaining unit has been sufficient--though the machine has flown naturally at a reduced rate--to enable the pilot to regain his own lines. In peace flying, too, as well as in war, the multiple-engined aeroplane brings a new factor of safety. If one of his motors fails, and he is over country which offers no suitable landing-place, the pilot with a duplicate power-plant need not be concerned. His remaining unit or units will carry him on. There are problems with duplicate engines which remain to be solved--problems of a technical nature--which involve general efficiency, transmission gear, and the number and the placing of propellers; but already, though this new stride in aviation is in its earliest infancy, results that are most promising have been obtained. To those who study aviation, and have done so constantly, say from the year 1909, one of the most striking signs of progress lies in the fact that, though unable at first to fly even in the lightest winds, the aviator of to-day will fight successfully against a 60 miles-an-hour wind, and will do battle if need be, once he is well aloft, with a gale which has a velocity of 90 miles an hour. He will ascend indeed, and fly, in any wind that permits him to take his machine from the ground into the air, or which the motor of his craft will allow it to make headway against. And here, though machines are still experimental, there is removed at one stroke the earliest and the most positive objection of those who criticised a man's power to fly. When the first aeroplanes flew the sceptics said: "You have still to conquer the wind, and that you will never do. Aeroplanes will be built to fly only in favourable weather, and this will limit their use so greatly that they will have no significance." But to-day the aviator has ceased, one might almost say, to be checked or hampered by the wind. If the need is urgent, as it often is in war, then it will be nothing less than a gale that will keep a pilot to the ground, provided he has a sufficiently powerful machine, and a suitable ground from which to rise--and granted also that he has no long distance to fly. Wind-flying resolves itself into a question of having ample engine-power, of being able to launch a machine without accident, and get it to earth again without mishap; and of being able to make a reasonable headway against the wind when once aloft; and these difficulties should solve themselves, as larger and heavier machines are built. Apart from the growing skill of the aviator, which has been bought dearly, science can now give him a machine, when he is in a wind, that needs no exhausting effort to hold it in flight. Craft are built, as a matter of certainty and routine, which have an automatic stability. Science has made it possible indeed, by a mere shaping and placing of surfaces, and without the aid of mechanical devices, to give an aeroplane such a natural and inherent stability that, when it is assailed by wind gusts in flight, it will exercise itself an adequate correcting influence. To understand what this means it should be realised that, when such a machine is in flight say in war on a strategical reconnaissance, and carries pilot and passenger, the former can take it to a suitable altitude and then set and lock his controls, and afterwards devote his time, in common with that of his passenger, to the making of observations or the writing of notes. The machine meanwhile flies itself, adapting itself automatically to all the differences of wind pressure which, if it had not this natural stability, would need a constant action of the pilot to overcome. All he need do is to maintain it on its course by an occasional movement of the rudder. With such a machine, even on a day when there is a rough and gusty wind, it is possible for an airman to fly for hours without fatigue; whereas with a machine which is not automatically stable, and needs a ceaseless operation of its controls, the physical exhaustion of a pilot, after hours of flight, is very severe. So, already, one sees these factors of safety emerge and take their place. There is no longer a grave peril of machines breaking in the air; there need be no longer, with duplicate power-plants, the constant risk of engine failing; while that implacable and treacherous foe, the wind, is being robbed daily of its perils. CHAPTER IX A STUDY OF THE METHODS OF GREAT PILOTS The masters of flying, and this is a fact the novice should ponder well, have been conspicuous almost invariably for their prudence. No matter how great has been their personal skill, they have never lost their respect for the air; and this is why so many of the great flyers, after running the heaviest of risks in their pioneer work, have managed to escape with their lives. What patience and sound judgment can accomplish, when pitted even against such dangers as must be faced by an experimenter when he seeks to fly, is shown by an incident from the early career of the Wright brothers. With one of their gliders, a necessarily frail machine, and in tests made when they were both complete novices, they managed to make nearly 1000 glides; and not once in all those flights, during which they were learning the rudiments of balance and control, did they have a mishap which damaged at all seriously their machine. These two brothers, Wilbur and Orville, offer to the student of flying, apart from the historical interest which is attached to their work, a temperamental study of the greatest interest. Wilbur, who was grave, judicial--a man of infinite patience and with an exceptional power of lucid thinking--found in his brother and co-worker, Orville, a disposition just such as was necessary to strengthen and support him in his great research; a disposition more vivacious and more enthusiastic than his, and one which acted as a balance to his own gravity. The method of these brothers in first attacking a mass of data, most of it contradictory--and a large amount of it of little intrinsic value--and then framing their own research on lines which they discussed and studied with methodical care, forms a model of sound judgment for workers in any complex field. Their kite experiments, their gliders, their refusal to hasten their steps unduly in the fitting of an engine to their machine, reveal again their discretion, and that judgment which never failed them. Perseveringly and unswervingly, exhibiting doggedness without obstinacy, and with their work illuminated always by the highest intelligence, they moved surely from stage to stage; and at last, when they fitted a motor to their machine, such was their knowledge of the air, and of the control of their craft when in flight, that they were able to make this crucial step, from a glider to a machine driven by power, without any breakage of their apparatus or injury to themselves. The same self-control marked them when, having demonstrated that men can ascend in a power-driven machine, and steer such a craft at will, they dismantled their apparatus and commenced their negotiations with foreign Governments. Wilbur Wright, too, when he came to France to give his first public demonstrations, provided by his methods a model for aviators, either present or future. He resisted all temptations to make injudicious flights. If he considered the weather conditions at all unsuitable he said that he would not ascend, no matter who might have come to see him fly, and that settled the question once and for all. He was deaf to all pleadings, to all proffered advice. When conditions were perfectly suitable, and then only, would he have his craft brought from its shed. The same meticulous care, in every flight he made, marked his preparation of his machine. Motor, controls, propeller-gearing, every vital part, received its due attention; and this attention was never relaxed, no matter how frequently he flew, nor how great was his success. An observer of one of his early flights at Le Mans has given us an impression that is typical of this unremitting care. There was a question of some small adjustment that Wilbur had instructed should be made to the machine. When the time came to fly, and he was in the driving-seat waiting for the motor to be started, he called a question as to whether this detail had been attended to. He was assured it had. But this was not enough for Wilbur Wright. Climbing from his seat and walking round the biplane, he made a careful examination for himself, and then returned quietly to the front of the machine. People who came to see him fly, and expected some picturesque hero, leaping lightly into his machine and sweeping through the air, found that reality disappointed them. This quiet, unassuming man, who slept in his shed near his aeroplane, and took his meals there also, refused to be fêted or made a fuss of; while his deliberation in regard to every flight, and his indifference to the wishes or convenience of those who were watching him, drove nearly frantic some of those influential people who, coming in motor-cars and with a patronising spirit, thought the aviator might be treated rather as a superior mountebank, who would be only too glad to come out and fly when a distinguished guest arrived. M. Louis Bleriot, whose name was next to become world-famous, after that of the Wrights, and who owed his distinction to his crossing of the English Channel by air, revealed in his character determination and courage, and imagination as well. And yet allied to these qualities--and here lay his temperamental strength--he had a spirit of quiet calculation and an eery considerable shrewdness. He knew, and was not afraid of showing that he knew, the full value of caution. And yet on occasion also--as in the cross-Channel flight--he was ready to put everything to the test, and to take promptly and with full knowledge the heaviest of risks. The motor in his cross-Channel monoplane was an experimental one of low power, air-cooled, and prone to over-heat and lose power after only a short period of running. To cross the Channel, even under the most favourable circumstances, he knew this engine must run without breakdown for thirty-five or forty minutes. This it had not done--at any rate in the air--before. There was a strong probability--and Bleriot knew this better than anyone else--that the motor would fail before he reached the English shore, and that he would have to glide down into the sea. It was arranged that a torpedo-boat-destroyer should follow him, and this afforded an element of safety. But Bleriot guessed--as was actually the case--that he would outdistance this vessel in his flight, and soon be lost to the view of those upon it. And he did not deceive himself as to what might happen, if his engine stopped and he fell into the water. His monoplane, as it lay on the surface of the water, would, he knew, prove a very difficult object to locate by any vessel searching for it; while it was so frail that it would not withstand for long the buffeting of the waves. He carried an air-bag fixed inside the fusilage, it is true; but, in spite of this precaution, Bleriot knew he ran a very grave peril of being drowned. There was, on the morning of his flight, another disturbing factor to be reckoned with. The wind, calm enough when he first determined to start, began very quickly to rise; and by the time he had motored from Calais to the spot where his aeroplane lay, and the machine itself was ready for flight, the wind out to sea was so strong that the waves had become white-capped. But Bleriot, aware of the value at such moments of decision, had made up his mind. He knew that, if his engine only served him, his flight would be quickly made. And so he reckoned that, even though the wind was rising, he would be able to complete his journey before it had become high enough seriously to inconvenience him; and in this calculation, as events proved, he was right. His motor did its work; and, though the wind tossed his machine dangerously when he came near the cliffs of the English coast, he succeeded in making a landing and in winning the £1000 prize. M. Hubert Latham, Bleriot's competitor in the cross-Channel flight, had that peculiar outlook on life, with its blend of positive and negative--puzzling often to its owner as well as to the onlooker--that is called, for the sake of calling it something, the artistic temperament. He was impulsive, yet impassive often to a disconcerting extent: extremely sensitive and reserved as a rule, yet on occasion almost boyishly frank and communicative. He lacked entirely ordinary shrewdness, or everyday commonsense. He was a man of a deeply romantic temperament, and this inclined him towards aviation and the conquest of the air; while in actual piloting he had such a quickness and delicacy of touch, and such a sure and instinctive judgment of distance and of speed, that he was undoubtedly a born aviator--one of, if not the, finest the world has seen. That he did not attain greater success, from a practical point of view, was due to the fact that he was without the level-headedness and the business ability which characterised others of the pioneers. When he was in flight in his Antoinette--Latham flew that machine and no other--he was a supreme artist. His machine was beautiful, and his handling of it was beautiful. M. Henri Farman, beyond question, of course, another of the great pioneers, is a man of imagination and of a highly nervous temperament, yet possessing at the same time a very pronounced vein of caution. No success has for an instant caused him to lose his head. At Rheims, in 1909, when he had created a world's record by flying for more than three hours without alighting, those who hastened to congratulate him, after his descent, found him absolutely normal and unmoved. Washing his hands at a little basin in the corner of the shed, he discussed very quietly and yet interestedly, and entirely without any affectation of nonchalance, the details of his flight and the behaviour of his motor. His attitude was that the flight was something, yet not a great deal, and that very much more remained to be done; a perfectly right and proper attitude, one which was just as it should be, yet one encountered very rarely under such circumstances--human nature being what it is. Farman's patience, his perseverance, were in the very early days what gave him his first success. With the biplane the Voisins built him, for example, nothing but his own determination, and his ceaseless work upon his engine, enabled him to do more with this type of machine than others had done. As the aeroplane increased in efficiency, and in the reliability of its engine, and was used in cross-country journeys, there came an era of flying contests, in which large prizes were offered, and in which airmen passed between cities and across frontiers, and traversed in their voyages the greater part of Europe. In the making of these flights, which needed an exceptional determination and skill, allied also to a perfect bodily fitness, there came into prominence certain aviators whose precision in their daily flights, passing across country with the speed and regularity of express trains, won admiration throughout the world. Prominent among these champions was the French naval officer, Lieut. J. Conneau, who adopted in his contests the flying name of "Beaumont." His success and his exactitude, when piloting a Bleriot monoplane for long distances above unknown country, guiding himself by map and compass, gave the public an indication, for the first time, of what might be accomplished by an expert airman when flying a reliable machine. Lieut. Conneau's success, winning as he did several of the great contests one after another, and the absence of error in his flying from stage to stage, and his accurate landings upon strange and often badly-surfaced aerodromes, should provide for the novice in aviation--when the secret of this success is understood--an object-lesson that is of value. This quiet, efficient airman, and his methods in making himself so competent, afford indeed an interesting study. Here was one who, suited already by temperament for the tasks he undertook, trained himself with such care, with such patience, that he attained as nearly to the ideal as is possible for living man. When he had asked for, and obtained, permission from the Minister of Marine to study aviation in all its aspects, he began his task in a spirit that was admirable. "I was convinced," he wrote afterwards, "that a perfect knowledge of machines and motors was necessary before one could use them." For nearly a year, on leaving the sea, he worked to obtain a certificate as a practical engineer. This gained, he went through a period of motor-cycling and motor-car driving, varied by flights in captive balloons and free balloons, and afterwards in airships. Following this he obtained leave to stay for a time at Argenteuil, and enter the works of the builders of the Gnome motor. Here he lived the life of a mechanic, and learned to understand completely the operation of this famous engine, which he was destined to drive afterwards in his great flights. Presently he went to Pau, in order to obtain his certificate as an aeroplane pilot. At first, taking his turn with a number of other pupils, he could only get a few minutes at a time in a machine. But being a keen observer he found that, by listening to the instructors, and watching the flights made, he could pick up useful information without being in the air; and this led him to the observation that "to learn to fly quickly, one must begin by staying on the ground." He secured in due course his certificate of proficiency, astonishing the instructors by his skill and sureness in the handling of his machine. Then followed what might be called an apprenticeship to cross-country flying. He made constant flights in all weathers, flying for instance from Pau to Paris, and studying closely not only the piloting of his machine and the aerial conditions he encountered, but also the art of using a map and compass, and in finding a path without deviation from point to point. Improving daily in confidence and skill, and learning practically all there was to be learned as to the handling of a Gnome-engined Bleriot, he was able soon to fly under weather conditions which would have seemed hopeless to a pilot of less experience; while engine failure and other troubles, which overtook him frequently on these long flights, taught him to alight without damaging his machine on the most unpromising ground. Now, feeling himself at last competent, he obtained permission to figure on the retired list, so that he might take part in the aviation races which were then being organised. Of these great contests Lieut. Conneau won three in succession--the Paris-Rome Race, in which he flew 928 miles in 21 hours 10 minutes; the European Circuit, in which he flew 1,060 miles in a total flying time of 24 hours 18 minutes; and the Circuit of Britain, in which he flew 1,006 miles in 22 hours 26 minutes. Lieut. Conneau's success, which appeared extraordinary, and his skill in finding his way across country, which seemed abnormal, were due as a matter of fact to his assiduous preparation, and to a temperament which, even under the heavy strains of constant flying, saved him from errors of judgment or ill-advised decisions. His temperament was, indeed, ideal for a racing airman. He was quiet and collected, with a natural tendency to resist excitement or confusion. His physique was admirable, and he had that elasticity of strength, both in body and nerve, which are invaluable to a pilot when on long flights. Also, and this was of importance, Lieut. Conneau had a natural cheerfulness of disposition which carried him without irritation or despondency through those ordeals of weather, and of mechanical breakdowns and delays, which are inseparable from such contests as those in which he was engaged. A contrast to Lieut. Conneau, both in temperament and method, was his rival Jules Vedrines--the aviator who, notably in the Circuit of Britain, flew doggedly against Lieut. Conneau from stage to stage. Vedrines, who had not had the advantages in tuition that had been enjoyed by Lieut. Conneau, nor his grounding in technique, was nevertheless a born aviator; a man of a natural and exceptional skill. In energy, courage, and determination he was unexcelled; but such qualities, though of extreme value in a long and trying contest, were marred by an impetuosity and an excitability which Vedrines could not master, and which more than once cost him dear. He had not, besides, as was shown in the Circuit of Britain, that skill in steering by map and compass which aided Lieut. Conneau so greatly in all his flying. A personality of unusual interest was that of the late Mr. S. F. Cody--a man of a great though untutored imagination, and of an extraordinary and ceaseless energy. A big man, and one whom it might be thought would have been clumsy in the handling of an aeroplane, he piloted the biplanes of his own construction with a remarkable skill. He flew no other, of course, and this was greatly to his advantage in actual manipulation. The great pilots who have excelled--one may instance again Lieut. Conneau--have concentrated their attention as a rule on one type of machine, learning all there is to be learned about this particular craft, and being prepared in consequence, through their knowledge both of its capacities and weaknesses, for any contingency that may arise in flight. Another instance of such specialisation was provided by Mr. Gustave Hamel. M. Bleriot--an admirable judge in this respect--singled out Mr. Hamel, while this young man was learning to fly in France, as an aviator of quite unusual promise; and his prediction was, of course, more than fulfilled. Devoting himself exclusively to the monoplane, Mr. Hamel became a pilot whose perfection of control, very wonderful to witness, was marked strongly by his own individuality. He had beautiful "hands"--a precision and delicacy on the controls which marked his flying from that of all others; while his judgment of speed and distance, which was remarkable, represented natural abilities which had been improved and strengthened by his constant flying. CHAPTER X CROSS-COUNTRY FLYING When a pupil has finished his flying school tests, and has received his certificate from the Royal Aero Club, he is in a stage of proficiency which means that he has learned to control an aeroplane when above an aerodrome and in conditions that are favourable, and that he may be relied on to make no elementary mistakes. But as to cross-country flying, with its greater hazards, he is still a novice, with everything to learn. And so it is to flights from point to point, generally between neighbouring aerodromes, that he next devotes himself. Aviators have been commiserated with, often, on what is thought to be the monotony of a cross-country flight. The pilot, raised to a lonely height above the earth, is pictured sitting more or less inertly in his seat, with nothing to do but retain his control on the levers, and look out occasionally so as to keep upon his course. But the beginner, when he first attempts cross-country flying, will have an impression not of inactivity, but of the necessity to be constantly on the alert. He will be engrossed completely by the manipulation of his machine, with no time to sit in idle speculation, or to analyse his feelings as the country passes away below. When preliminaries on the ground have been gone through, and the pilot is in the air, there will first be a need to gain a height of several thousand feet. Altitude is essential in cross-country flying. The higher a pilot flies, within reason and having regard to the state of the atmosphere, the better chance will he have of making a safe landing, should his motor fail suddenly and force him to descend. So the first concern is climbing--and in doing so the pilot must remember the teachings of his instructor, and not force his craft on too steep or rapid an ascent. He may prefer, in his early flights, to remain above the aerodrome while he is gaining altitude, watching his height recorder from moment to moment so as to note his progress upward. He will be occupied also with his engine, listening to its rhythm of sound, and keeping an eye on the indicator that tells him how many revolutions per minute the motor is actually making, and which will warn him at once should it begin to fail. Granted his motor is running well, a pilot should soon gain altitude. Then, assuming the air is clear--as it should be on his early flights--he will note some landmark, away on the line of his flight, and set off across country towards it. Fixed conveniently in front of him will be a map, of a kind devised specially for the use of aviators. A pilot's view, as he flies high above the ground, is bird-like. Landmarks fail to attract his attention, at this altitude, which would be clearly seen if he were on the ground. Hills, for example, unless they are high, are so dwarfed as he looks down on them that they scarcely catch his eye. What is done, by the designer of air maps, is to accentuate such details of a landscape as will prove conspicuous when seen from above. A river, or an expanse of water, is clearly seen; so also are railways and main roads; while factory chimneys, and large buildings which stand alone, may be identified from a distance when a pilot is in flight. So on an airman's map, made to stand out by various colourings in a way that catches the eye, are railways, roads, rivers, lakes and woods, with here and there a factory chimney or a church, should these be in a position rendering them visible easily from the air. That such maps should be bold in their design, and free from a mass of small details, is very necessary when it is remembered that the aviator, passing through the air at high speeds, has no time for a leisurely inspection of his map. With a good map, and aided when necessary by the compass that is placed in a position so that he can see it readily, a pilot has no difficulty as a rule, once he has acquired the facility that comes with practice, in steering accurately from point to point, even when on a long flight. On a favourable day, when the land below is clearly visible, he will glance ahead, or to one side, and after observing some landmark, look on his map to identify the position he has just seen. Under such conditions steering is easy, and the compass plays a subsidiary part. But it may happen that, while he is on a long flight and at a considerable altitude, the earth below may be obscured by clouds, or a low-lying mist, and all landmarks vanish from his view. Sometimes too, he may find himself flying through mist and cloud, with all signs of the earth gone from below. Whereupon, robbed for awhile of any direct guidance, he must fly by aid of his map and compass, holding his machine on its compass course, and noting carefully the needle of his height-recorder, so that he is sure of maintaining altitude. A risk exists under such conditions, when there is no visible object by which to judge a course, that an airman may make leeway, unconsciously, under the pressure of a side-wind; and so he must be ready to note carefully, immediately that a view of the earth is vouchsafed him, whether he has actually been making leeway, either to one hand or the other, even while the bow of his machine has been held on its compass course. There is a risk also, when a pilot is flying in fog or at night, that, having no visible horizon from which to gauge the inclination of his craft, it may assume gradually some abnormal angle, without his own sensations telling him what is taking place. The craft may, for the sake of illustration, incline sideways, imperceptibly to the pilot, till it begins to side-slip. But science can meet this danger by providing inclinometers, fitted within the hull so that the aviator can see them easily; and by means of these instruments, which are illuminated at night, it is possible for a pilot to tell, merely by a glance, at what angle his machine is moving forward through the air--whether it is up or down at the bow, or whether its position laterally is normal. The beginner, on his first cross-country flight, need not be troubled by such intricacies. He is flying, one assumes, on a fine day, with the land spread clearly below him. So as he moves through the air, listening always to the hum of his motor, he need have no fear, granted that his observation is ordinarily keen, of losing his way. Naturally, being a novice, he will feel the responsibility of his position. His eyes will rove constantly from one instrument to another; as indeed, from habit, do those of a practised flyer. He will glance at the height recorder; then at the engine revolution indicator; then at the dial which tells him what his speed is relative to the air. There is a dial, also, showing the pressure in his petrol-tank; while there will be a clock on his dashboard at which he will glance occasionally, after he has marked some position away on the land below, so as to determine what progress he is making from the point of view of time. Besides these preoccupations, and the ceaseless even if almost unconscious attention that he must pay to his engine, there is the need to bear constantly in his mind's eye the lie of the land. Should his motor fail suddenly, or something happen which necessitates an immediate descent, it is imperative that he should be able, without delay, to choose from the ground that is visible below him some field or open space that will provide a safe landing-point. And this is easier said than done. The earth, when viewed by a airman who looks down almost directly upon it, is apt to be deceptive as to its contour. A field that is selected say, from a height of several thousand feet, may not prove--as the aviator nears it in his glide--to be at all the haven he imagined it. More than once, seeking to alight on a field which appeared to him, as he was high above it, to be level as a billiard table, a pilot has found, when it is too late, that the ground has sloped so steeply that his machine, after landing, has run on downhill and ended by crashing into a fence or ditch. It is very necessary for an airman to learn to judge, by its appearance, the difference between an expanse, say, of pasture land, or a field which is in green corn or standing hay. It has happened often that a pilot, descending after engine failure towards what he has reckoned a grass field, has discovered--when too low to change his landing-point--that his pasture land is actually a field of green corn; and a landing under such conditions, with the corn binding on the running-gear of the machine, may end in the aircraft coming to an abrupt halt, and then pitching forward on its nose; with a broken propeller and perhaps other damages in consequence. In choosing a landing ground, as in other problems that face the novice in cross-country flying, experience will prove his safeguard. He will learn for instance that cattle or sheep, if they can be discerned below in a field, go to show that this field is one of pasture and not of crops. If no cattle are to be seen in a field, and the aviator is doubtful about it, and yet if it happens to be the only suitable one he can locate, then he may look closely at the gateway which leads into the field. If, in this gateway, he can detect such scars or markings on the ground as are caused by the feet of cattle as they walk daily in and out, he may feel satisfied the field is one of pasture. When cattle or sheep are seen standing in a field so that they face in the same direction, this may suggest either the existence of a slope, or the presence of a strong ground wind; while a stream or brook at the edge of a stretch of open land, or a belt of woods, may suggest a sloping of the ground. It is amusing for a pilot--or it was so, rather, in the days when few aeroplanes were in existence--to note the astonishment which his descent, made quite unexpectedly perhaps in some quiet and rural country, will occasion amongst the inhabitants. Sometimes, under the stress of such an excitement, people appear to lose for the time being their power of coherent speech. A pilot in a cross-country contest, not being sure whether he was on his right course, decided to make a landing and ask his way. He noticed, after a while, the figure of a man in a field below. Planing down, and alighting in the field, he shouted questions to this man, switching his engine off and on, while he did so, in order that his words, and those of the other, might be audible. But the man in the field, demoralised by the advent of this being from the air, and gazing at him and his machine with an expression of blank amazement, was unequal to the task of giving even the simplest directions. He waved his arms, it is true, but no words that could be understood issued from his lips. The pilot repeated his questions, but it was no good. The man waved and mouthed, and rolled his eyes, but when he tried to speak intelligibly he could not. So the aviator, loath to waste further time, accelerated his engine again and continued his flight. As a contrast to this, there was the experience of a pilot who, after a long flight from England to the Continent, landed at length near a small village. In the next field to that in which he alighted there was a labourer, digging patiently. The aviator expected that this man would fling down his spade in excitement, and run wildly towards the aeroplane. But such was not the case. This labourer, a marvel of placidity and unconcern, merely raised his head slowly and looked across at the aircraft, and then went on with his digging. In his first cross-country flights, being concerned chiefly as to the manipulation of his machine, and having so many things to think of, the novice may feel tired after even a short journey by air. His chief sensation, as he switches off his engine to descend towards the aerodrome he sees below him, will be one of relief that he has escaped engine failure, and that he has been able to find his way from point to point. The joy of flight, of passing swiftly thousands of feet above the earth, will have made but a small impression upon him--at any rate consciously. It will not be until the handling of his machine becomes less laborious, and he has time to accustom himself to his unique view-point, and the strangeness and beauty of the scene below him, that the novice will realise some of the fascinations of aerial travel; fascinations that it is difficult to describe. The sensation of having thrown off the bonds of earth-bound folk; of soaring above the noise and dust of highways; of being free from the obstructions of traffic; of sweeping forward smoothly, swiftly, and serenely--the land stretching below in an ever-changing panorama, with the drone of the motor in one's ears, and a wine-like exhilaration in the rush of the air: these, and others more obscure, are among the sensations of cross-country flying. CHAPTER XI AVIATION AS A PROFESSION Young men, and parents on their behalf, are seeking always some profession which will yield an adequate return for the enthusiasm which youth lavishes upon it. Too often, though, at any rate in the past, this search for a man's work in life has been narrowed into ruts; conducted on certain set lines which, though they have found employment for the beginner, have given him no scope for that enthusiasm with which he will attack the first tasks presented him. Aviation, till the coming of the war, was looked at askance by parents who had sons on their hands. Apart from the risks of flying, which appeared to them ceaseless and terrible, the actual industry of building aeroplanes, regarded as an industry, seemed so haphazard and objectless an affair--so much like playing at work--that they discouraged any wish that a youth might show to enter it. Many people, these people of intelligence, regarded the building and flying of aeroplanes as being no more than a passing phase, and a regrettable one, which it was hoped men would soon abandon, and turn their attention to tasks more serious and profitable. But that was before aircraft had proved their value as instruments of war. Now it is known that aeroplanes have the power, granted they are supplied in sufficient numbers, of altering the tenor of a great campaign, both by land and sea; and that in any future war of nations, should one come, a battle between the hostile flying fleets, fought to determine the command of the air, will determine also, to a very large extent, the fortunes of armies on the land and navies on the sea. It is clear indeed that, for any great nation that strives to maintain its place, a powerful air fleet has become a necessity; while for Britain, an island no longer from the military point of view, seeing that we must face seriously the question of invasions by air, there is a vital need to strive for command of the air, as we now hold command of the sea. The building up of our air fleet will be an arduous task, needing men, money, and time; but without it we cannot be secure. Therefore the work must be faced, the men and the money forthcoming. Aviation, as an industry, must prepare for years of strenuous work. A great air service must be created. Machines must be designed and built in thousands instead of hundreds, and men trained to fly them. Nor is this all. The aeroplane, though it has such significance as a weapon of war, is destined primarily and eventually to be an instrument of peace; a machine for the transport by air of passengers, mails, and goods, at speeds greater than will be feasible by land or water; and a craft also for the use of travellers and tourists, enabling them to make such journeys, with ease and pleasure, as will again prove impossible by land or sea. So aviation has two immense tasks ahead of it, instead of one. Not only must it create, by years of patient and determined effort, a flying service which will command the air, but craft must be designed and built also for the mail, goods, and passenger-carrying services, and to meet the needs of the aerial tourist. This new task that has been given to men, that of designing, building, and piloting aircraft, is still on the eve of its expansion. The opportunities it offers to young men--to men whose minds are quick to grasp a new idea and who have the powers of initiative and decision--are almost boundless. Flying will, as it develops, revolutionise the world's system of transport; while the developments even of the immediate future promise to be so great, and so important, that it is not easy to visualise them. But this at least is clear: now is the time for newcomers to enter the world of flight. Aviation needs men, is calling aloud for men; and they are needed for many kinds of work. First, of course, should be placed the flying services, naval and military, to join which during the war men have come forward so admirably. But it will need, in the expansion that must follow this campaign, a steady and a ceaseless growth in numbers, not only of the men who handle machines in flight, but of those who serve the squadrons by their work on land, and who build up the organisation which is vital to success. For skilled aviators, other than those who join the services, there is scope for remunerative work. A constant demand exists for men who will test and fly in their trials the new machines that are built by manufacturers; for men who will fly, in public exhibitions, the craft that are used at the various aerodromes; and for men who will qualify as instructors, and join the flying schools which are already in existence, or in process of formation. In countries oversea, too, there is the definite promise that aircraft will be needed, not only for survey work over wide tracts of land, and for maintaining communication and bearing mails over districts where land travel is difficult, but also for exploration; and this again means that pilots will be required. New aerodromes must come into existence also; not only to act as alighting points for touring craft, but to provide grounds for the training of pupils; and at these aerodromes pilots will be needed. Of other opportunities, apart from the piloting of aircraft, there are many--though it is desirable for a man to learn to fly, and obtain his certificate of proficiency, even if afterwards he does not intend continuing as a pilot. The practical experience he gains, while learning actually to handle an aircraft in flight, will prove extremely useful to him subsequently, even though the task he undertakes is one that keeps him on the ground. He may qualify, for instance, for a post in a aeroplane factory as a designer or draughtsman; or he may specialise in aero-motors, and seek a post in the engine-shops. At the aerodromes, too, there are openings which present themselves; as, for example, in the management of a flying school. It has been shown that the public will go in thousands to see sporting contests with aeroplanes, and here is another field for organisation and effort; while there is a constant demand for men of ability in the executive departments of firms which are established already in the industry, and are expanding steadily, or in those which are now being formed, or are joining aviation from day to day. The industry is at last on a footing that is practical and sound. It presents a new field for effort, and one that is unexploited; while for the man who enters it--and this should be the attraction for youth--there are occupations as fascinating as one's imagination could depict. But one thing must be understood clearly. Flying is, of exact sciences, surely the most exact. The man who is only half-trained, who is more or less slovenly in his work, who will not bend his whole energies to his task, will find no place in this new industry. A young man is wasting his time, if, after deciding to enter aviation, he acquires knowledge that is no more than haphazard. He who contemplates aviation as a profession must set himself the task of learning all there is to be learned, and in the right way. Individual opportunities and circumstances will, necessarily, play so large a part in the steps taken by a young man--or by his parents on his behalf--to launch him on a career in aviation that it is impossible, here, to do more than generalise. Certainly, as we have said, it is an excellent preliminary to learn to fly; and it may be stated also that it is now possible to place, with aviation companies of repute, premium pupils who will undergo instruction extending over a period of three years. A youth may, also, gain his knowledge of the industry by becoming an indentured apprentice. One may say, as a conclusion to this chapter, that a great, new, and potential industry is springing up in our midst, one which will prove to be equally if not more important and far-reaching than the British shipbuilding industry, and one which will employ thousands of skilled engineers and artisans. Ships are limited to one element, the water, which has very definite boundaries. Aircraft, too, are limited to one element, the air; but this element has no boundaries so far as the earth is concerned, and aircraft will be navigable to any and every part of the globe. CHAPTER XII THE FUTURE OF FLIGHT It is a hopeful augury, to those concerned with aviation, that public interest in flying should not only be keen, but should be growing. In the early days, even when aeroplanes were so great a novelty, it was difficult to induce people in any numbers to witness a flying display. The first meetings, though they were organised with enthusiasm, ended as a rule with a heavy financial loss; and this fact of course, when it became known, had a discouraging influence on those who might, had these early meetings proved a success, have been willing to finance aerodromes and the building of machines. But as it was, business men, who are quick to form conclusions, said that people would never be induced to pay to see aeroplanes fly. But here they failed to reckon with the fact that, though public interest in flying has been of very slow growth, yet at the same time it has been a steady and continuous growth. From month to month, and from year to year, as aeroplane constructors and pilots have continued at their tasks, overcoming technical difficulties and personal risks, the interest of ordinary people has grown perceptibly. Even before the war--which has done so much to focus attention on flying--the attitude of scepticism and apathy had been greatly changed. When the London Aerodrome at Hendon was established, there were shrewd men in the city, men who are ordinarily very sound in their conclusions, who declared the public would never go there in appreciable numbers. How wrong they were, how little they gauged the change that was taking place in the public mind, is shown by the fact that, on a popular day at this aerodrome, as many as 60,000 people have paid for admission. In the immediate future, as in the immediate past, aviation will be concerned largely with the building of naval and military craft. This will, so to say, be the foundation of its development in other directions. War for instance, notably in the fitting of craft with duplicate power-plants, will provide data that is invaluable in the building of commercial craft, and in machines also for the use of the tourist. In aerial touring there lies an important field for the development of aircraft--one which may serve to bridge the gap between a relatively small, purely pleasure-type machine, and a craft which has utility in the fields of commerce. The motor-car provides an enjoyable means of travelling from place to place; but in the aeroplane, once it is airworthy, reliable, and comfortable, the tourist has a vehicle which is distinctly more pleasurable and exhilarating. The day was dawning before the war, and will now be hastened, when, garaging his aircraft at the London Aerodrome as a convenient starting-point, an aerial traveller will tour regularly by air, using his flying machine as he would a motor. Already, dotted about England, are aerodromes he may use as halting-points on his flight, and at which he can house his machine and secure the attention of mechanics; and the number of these grounds should grow rapidly in the future. In the aeroplane for the tourist, for the man who buys a machine and flies for his own pleasure, it is necessary to combine comfort and safety. As regards comfort, though much remains to be done in the perfection of detail, the occupants of a machine are now more studied than they were in the pioneer days. Then a pilot sat out on a crude seat, exposed fully to the rush of wind as a machine moved through the air. Now he is placed within a covered-in hull, a screen to protect him from the wind. From this stage, as was the case with the motor-car, rapid progress should be made in a provision of comfort. When touring by air under favourable conditions, there should be no more risk with an aircraft than with a motor-car. One of the most frequent causes of accident, as we have shown, has been the structural weakness of a machine. Now, with the experience of the war on which to draw, and with many clever brains focussed on the development of the industry, this risk may be regarded as almost non-existent; as negligible a factor as it is possible to make it, remembering that aircraft, like other mechanism, have to be built by human hands. Another risk, that of engine failure, may, as we have explained, be eliminated by the use of more than one motor. In the application of such systems there is still much to be learned; but the obstacles are not insuperable. One advantage that can be offered the aerial tourist, reckoning him as a pilot of no more than average skill, who needs all the aid that science can give him, is that he can obtain a machine which, owing to its automatic stability, requires merely to be taken into the air and brought to earth again, and which will practically fly itself, once it is aloft. One of the needs with a touring machine, to which makers must devote their attention, is that it should be able to leave the ground quickly in its ascent, and so permit its pilot to rise even from a small starting ground. And it is equally necessary that, on occasion, a machine should be able to alight safely, and at a slow speed, in quite a small field. An aviator who had given up aviation temporarily, after a long spell of cross-country flying, was asked one day when he was going to fly again. "I shan't do so," he said, "till I can buy a machine with which I can alight in my own garden." Already there are craft which, provided high speeds are not expected of them, and they are given ample plane-surface, will alight at quite a moderate pace; but in the future, by the use of machines which have the power of increasing or reducing their wing-surfaces while in flight, it should be possible to descend in a space no larger, say, than a garden. In the construction of variable-surface machines, technical problems need to be faced which are unusually difficult. The theory with such craft is that their sustaining planes, either by a telescopic system, or by some process of reefing, are built so that they can be expanded or contracted at the will of the pilot. Thus in rising, when a machine is required to ascend with a minimum run forward across the ground, a large area of lifting surface would be exposed; and at the moment of alighting, also, when it was desired that a machine should make its contact with the ground at the slowest possible speed, a maximum of plane surface would be employed. But when aloft, and in full flight, the pilot would be able if he so desired to reduce the area of his lifting surface, and so increase materially his speed. With a machine of this type, when perfected, it should be possible to rise quickly, and descend slowly, and yet at the same time, when well aloft, attain a high speed with moderate engine-power. The commercial possibilities of aviation are vast and far-reaching: not for nothing, after centuries of striving, have men conquered the air. The aeroplane is destined, by the facilities it offers for communication between nations, to play a vital part in the growth of civilisation. The construction and perfection of a commercial aeroplane, a machine which can be used for the transport of passengers, mails, and goods, represents largely a question of time and of money. Technical problems still need to be solved. But none of them are insurmountable. All should be overcome by an expenditure of money and in the process of time--granted of course that research is directed upon the right lines. A sufficient amount of money for experimental work, which in aviation is very costly, was one of the prime difficulties before the war. Capitalists were chary of aviation; they had no faith in it. Now, after the work aircraft have done in war, and with the need to provide the world with air fleets, the industry need live no longer from hand to mouth. There should be funds available for experiments with commercial-type aeroplanes. As to the factor of time, this depends largely on the facilities that are obtained by the industry--apart from its work on naval and military craft--for test work with other machines. But in five years' time, granted progress continues on the lines now promised, we should have a service of passenger aeroplanes, each carrying fifty or more people, flying daily between London, the Midlands, and the North; while in ten years' time it should be possible to cross the Atlantic, from London to New York, by means of a regular service of aerial craft. The commercial aeroplane, even when perfected, would not be likely to compete successfully with other means of transit unless it could offer the advantages of a greater speed. Here, indeed, in the speeds they will attain, lies the future of aircraft. The air will be our highway because, in the air, speeds will be reached that are impossible on land or sea. As civilisation extends--this is of course a truism--there grows with it a need for speedier travel; and we have seen land and sea transit striving to meet this demand. But both have reached, or are rapidly reaching, a limit of speed--a limit imposed by the need to carry their passengers and goods on a remunerative basis. On the sea, by burning excessive quantities of coal, it is possible to add a few knots to the speed of a great liner. But then the problem becomes one of profit and loss; while with trains--so nearly under existing conditions have they reached a limit of speed--that a difficulty is experienced, even on long runs, and under favourable circumstances, in saving a minute here and there. It is not of course to be assumed, when the spur of a greater necessity comes, that land and sea transit will fail altogether to increase their existing speeds. There is the mono-rail system of land traction, electrically propelled, which has yet to be tested in a practical way; while on the sea, perhaps, under pressure of competition, and with an increasing demand for greater speeds, it may be possible to adapt with advantage, even on large craft, some principle of the hydroplane. But by way of the air, granted even a speeding-up on land and sea, should go the high-speed traffic of the future. By a greater efficiency in lifting surfaces and by reductions in the resistance a craft offers to its own passage through the air; by the provision of systems which will permit a pilot to reduce plane-area when his machine has gained altitude and he desires a maximum speed; by the equipping of craft with motors developing thousands of horse-power for a very low weight--by such means, and by a general improvement in design, it should be possible, eventually, to attain flying speeds of 150, 200, and even 250 miles an hour. From London to New York by air liner, in less than twenty hours; such, for instance, should be an attainment of the future. It seems probable, in the development of the commercial aeroplane, we shall have machines for touring and for pleasure flights--craft not of large size but in which efforts are made to obtain a greater reliability and comfort. Then it appears likely that aircraft may reach a practical use as carriers of mails and of light express goods; first of all in localities, and under conditions, which favour specially an aerial transit. And from this phase we should move to the passenger-carrying craft; to the days when we shall be able to spend a week-end in New York, as readily as it has been the habit to do in Paris; when we shall be able to reach any part of the world in a journey by air lasting, say, a week or ten days. Then, as a recompense for the lives that have been lost, and for a conquest that has been so dearly won, the world will enter upon an age of aerial transit--the age when frontiers and seas will act as barriers no longer, when journeys that now last weeks will be reduced to days, and those of days to hours; when first of all Europe, and then the world, will be linked by airway. THE END. INDEX AERODROMES, their evolution, 14 Age, its relation to flying, 11 Alighting, operation of, 51 BIPLANES and tuition, the "pusher" type, 16 Bleriot, Louis, study of his methods as a pilot, 84 CERTIFICATE of proficiency, tests for, 54 Cody, S. F., 90 Commercial possibilities of aviation, 107 Conneau, Lieut. J. ("Beaumont"), 87 Constructional weakness in aeroplanes, risks of, 60 Controllability of aeroplanes, problems of, 33 Cross-country flying, pupils' first experiences, 92 DUAL-ENGINE machines, 79 ENGINE failure, risks of, 65 Enjoyment of learning to fly, 12 FARMAN, Henri, pioneer work as an aviator, 86 Fees for tuition, 13 First flights, pupil as passenger, 39 HEALTH and flying, 10 Human factor in relation to accidents, 71 IMPROVEMENTS in aircraft which spell safety, 76 Industry of aviation, its expansion, 100 Instructors, qualifications necessary, 15 LATHAM, HUBERT, temperamental study, 86 Learning to fly not dangerous, 11 MANUAL dexterity, need of, 12 OPPORTUNITIES for the newcomer in aviation, 101 "ROLLING" (handling a machine on the ground), 43 SCHOOL aeroplanes, types of, 16 ---- aeroplanes, need for ample supply, 15 ---- biplane, its controls, 34 Schools, modern, their conveniences, 18 Sensations of flight, 41 Speed in its relation to flying, 31 Speed, promise of the future, 109 Straight flights, 44 Sustaining planes, their operation, 32 TEMPERAMENT, the ideal for flying, 22 Time required in learning to fly, 19 Touring by air, 105 Turning in the air, 46 VEDRINES, Jules, his piloting, 90 Vol-plané, the, 48 WEATHER, its effect on tuition, 38 Wind fluctuation, dangers of, 62 ---- flying, 80 Wrights, Wilbur and Orville, 82 BIBLIOGRAPHY _Some books selected as being likely to appeal to a man, without technical knowledge, who contemplates learning to fly._ "THE AIRMAN," by CAPTAIN C. MELLOR, R.E. Published by Mr. John Lane, the Bodley Head, London. (3s. 6d.) Describes the author's experiences, in France, while obtaining a brevet on a Maurice Farman biplane. "THE ESSAYS OF AN AVIATOR." Obtainable from "Aeronautics," 170, Fleet Street, London, E.C. (2s. 6d.) A series of admirable papers, written by a pilot and from a pilot's point of view. "THE AERONAUTICAL CLASSICS." A series of booklets issued at 1s. each by the Aeronautical Society, 11, Adam Street, Adelphi, London, W.C. Describe authoritatively, and very interestingly, the work of great pioneers. "FLIGHT WITHOUT FORMULÆ," by COMMANDANT DUCHENE, of the French Génie (translated from the French by John H. Ledeboer). Published by Longmans, Green & Co., 39, Paternoster Row, E.C. (7s. 6d.) Instructive discussions, clearly expressed, on the mechanics of the aeroplane. "PRINCIPLES OF FLIGHT," by A. E. BERRIMAN. Obtainable from "Flight" Offices, St. Martin's Lane, London, W.C. (2s.) "AERO ENGINES," by G. A. BURLS. Published by Charles Griffen & Co., 12, Exeter Street, Strand, London, W.C. (8s. 6d.). * * * * * AUTHORS' NOTE.--The above list does not, of course, pretend to be in any way complete. It is designed merely to act as a suggestion for the novice.--C. G.-W., H. H. * * * * * THE LONDON AND NORWICH PRESS LIMITED, LONDON AND NORWICH, ENGLAND 
31023	----	SMITHSONIAN ANNALS OF FLIGHT VOLUME 1 NUMBER 2 The First Airplane Diesel Engine: Packard Model DR-980 of 1928 _Robert B. Meyer_ SMITHSONIAN INSTITUTION NATIONAL AIR MUSEUM · WASHINGTON, D.C. [Illustration: Frontispiece--President Herbert Hoover (in front of microphones) presenting the Collier Trophy to Alvan Macauley (nearest engine), President of the Packard Motor Car Co., on March 31, 1932 (although the award was for 1931). Also present were Hiram Bingham, U.S. Senator from Connecticut (nearest pillar), Clarence M. Young, Director of Aeronautics, U.S. Department of Commerce (between Macauley and Hoover), and Amelia Earhart, first woman to fly across the Atlantic Ocean (between Macauley and the engine). In the foreground is a cutaway Packard diesel aeronautical engine and directly in front of Senator Bingham is the Collier Trophy, America's highest aviation award. (Smithsonian photo A48825.)] SMITHSONIAN ANNALS OF FLIGHT VOLUME 1 · NUMBER 2 The First Airplane Diesel Engine: Packard Model DR-980 of 1928 ROBERT B. MEYER _Curator of Flight Propulsion_ SMITHSONIAN INSTITUTION · NATIONAL AIR MUSEUM WASHINGTON, D.C. · 1964 The following microfilm prints are available at the Smithsonian Institution: "The Packard Diesel Aircraft Engine--A New Chapter in Transportation Progress." An advertising brochure produced by the Packard Motor Car Company in 1930, illustrated, 17 pages. Fifty-Hour Test of the Engine by the Packard Company, 1930. Text and charts, 14 pages. Fifty-Hour Test of the Engine by the U.S. Navy in 1931: Text and charts, 26 pages. Packard Instructional Manual, 1931. Illustrated, 74 pages. "The Packard Diesel Engine," Aviation Institute of U.S.A. Pamphlet No. 21-A, 1930. Illustrated, 32 pages. For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C., 20402--Price 60 cents Contents _Page_ ACKNOWLEDGMENTS vi FOREWORD vii INTRODUCTION 1 History 2 DESCRIPTION 11 Specifications 11 Operating Cycles 13 Weight-Saving Features 15 Diesel Cycle Features 20 Development 23 COMMENTS 27 ANALYSIS 33 Advantages 33 Disadvantages 35 APPENDIX 1. Agreement Between Hermann I. A. Dorner and Packard Motor Car Company 43 2. Packard to Begin Building Diesel Plane Engines Soon 46 3. Effect of Oxygen Boosting on Power and Weight 47 Acknowledgments It is difficult to acknowledge fully the assistance given by persons and museums for the preparation of this book. However, I wish especially to thank Hugo T. Byttebier, engine historian, Buenos Aires, Argentina; Dipl. Ing. Hermann I. A. Dorner, diesel designer, Hanover, Germany; Harold E. Morehouse, and C. H. Wiegman, Lycoming Engines, Williamsport, Pennsylvania; Barry Tully, Goodyear Aircraft, Akron, Ohio; Richard S. Allen, aviation author, Round Lake, New York; William H. Cramer, brother of Parker D. Cramer, Wantagh, New York; Erik Hildes-Heim, Early Bird and aviation historian, Fairfield, Connecticut. I am particularly grateful to curators of the following museums who have been so generous in their assistance: Deutsches Museum, Munich, Germany (Dipl. Ing. W. Jackle); Henry Ford Museum, Dearborn, Michigan (Leslie, R. Henry); U.S. Air Force Museum, Wright-Patterson Air Force Base, Dayton, Ohio (Maj. Robert L. Bryant, Jr., director); Science Museum, London, England (Lt. Comdr. (E) W. J. Tuck, Royal Navy). The preparation of this paper could not have been accomplished without the aid of the National Air Museum of the Smithsonian Institution and the help of Philip S. Hopkins, director, and Paul E. Garber, head curator and historian. Foreword In this second number of the _Smithsonian Annals of Flight_, Robert B. Meyer Jr., curator and head of the flight propulsion division, tells the story of the first oil-burning engine to power an airplane, the Packard diesel engine of 1928, now in the collections of the National Air Museum. The author's narrative, well illustrated with drawings and photographs, provides a historical background for the development of the engine, and a technical description that includes specifications and details of performance. It also contains comments from men and women who flew planes powered by the Packard diesel. The author concludes with an analysis of the engine's advantages and disadvantages. PHILIP S. HOPKINS _Director, National Air Museum_ 30 July 1964 Introduction On display in the National Air Museum, Smithsonian Institution, is the first oil-burning engine to power an airplane. Its label reads: "Packard Diesel Engine--1928--This first compression-ignition engine to power an airplane developed 225 hp at 1950 revolutions per minute. It was designed under the direction of L. M. Woolson. In 1931, a production example of this engine powered a Bellanca airplane to an 84 hour and 33 minute nonrefueled duration record which has never been equalled.--Weight/power ratio: 2.26 lb per hp--Gift of Packard Motor Car Co." [Illustration: Figure 1 (left).--Front view of first Packard diesel, 1928. Note hoop holding cylinders in place and absence of venturi throttles. This engine was equipped with an air pressure starting system. (Smithsonian photo A2388.)] [Illustration: Figure 2 (right).--Left side view of first Packard diesel, 1928. Heywood starter (air) fitting shown on the head of the next to lowest cylinder. (Smithsonian photo A2388C.)] This revolutionary engine was created in the short time of one year. Within two years of its introduction in 1928, airplane diesel engines were being tested in England by Rolls-Royce, in France by Panhard, in Germany by Junkers, in Italy by Fiat, and in the United States by Guiberson. Packard had demonstrated to the world the remarkable economy and safety of the airplane diesel engine, and the response was immediate and favorable. The novelty and performance of the Packard diesel assured it a large and attentive audience wherever it was exhibited. Yet in spite of its performance record the engine was doomed to failure by reason of its design, and it was further handicapped by having been rushed into production before it could be thoroughly tested. History The official beginning of the Packard diesel engine can be traced to a license agreement dated August 18, 1927, between Alvan Macauley, president of the Packard Motor Car Company of Detroit, Michigan, and Dipl. Ing. Hermann I. A. Dorner, a diesel engine inventor of Hanover, Germany.[1] Before the agreement was drawn up, Capt. Lionel M. Woolson, chief aeronautical engineer for Packard, tested an air-cooled and a water-cooled diesel that Dorner had designed and built in Germany.[2] Both engines attained the then high revolutions per minute of 2000 and proved efficient and durable. They demonstrated the practicability of Dorner's patented "solid" type of fuel injection which formed the basis of the Packard diesel's design.[3] Using elements from Dorner's engines, Woolson and Dorner designed the Packard diesel with the help of Packard engineers and Dorner's assistant, Adolph Widmann. Woolson was responsible for the weight-saving features, and Dorner for the combustion system. The historic first flight took place on September 19, 1928, at the Packard proving grounds in Utica, Michigan, just a year and a month from the day Dorner agreed to join the Packard team. Woolson and Walter E. Lees, Packard's chief test pilot, used a Stinson SM-1DX "Detroiter." The flight was so successful, and later tests were so encouraging, that Packard built a $650,000 plant during the first half of 1929 solely for the production of its diesel engine. The factory was designed to employ more than 600 men, and 500 engines a month were to have been manufactured by July 1929.[4] [Illustration: Figure 3.--Alvan Macauley (left), President of the Packard Motor Car Co. and Col. Charles A. Lindbergh with the original Packard diesel-powered Stinson "Detroiter" in the background, 1929. (Smithsonian photo A48319D.)] The engine's first cross-country flight was accomplished on May 13, 1929, when Lees flew the Stinson SM-1DX "Detroiter" from Detroit, Michigan, to Norfolk, Virginia, carrying Woolson to the annual field day of the National Advisory Committee for Aeronautics at Langley Field. The 700-mile trip was flown in 6-1/2 hours, and the cost of the fuel consumed was $4.68. Had the airplane been powered with a comparable gasoline engine, the fuel cost would have been about 5 times as great.[5] On March 9, 1930, using the same airplane and engine, Lees and Woolson flew from Detroit, Michigan, to Miami, Florida, a distance of 1100 miles in 10 hours and 15 minutes with a fuel cost of $8.50. The production engine, slightly refined from the original, received the first approved type certificate issued for any diesel aircraft engine on March 6, 1930. The Department of Commerce granted certificate no. 43 after the Packard Company had ground- and flight-tested this type of engine for approximately 338,000 hp hr, or about 1500 hr of operation.[6] [Illustration: Figure 4.--Dipl. Ing. Hermann I. A. Dorner, 1930. German diesel engine designer, was responsible for the Packard DR-980 aircraft engine. (Smithsonian photo A48645.)] [Illustration: Figure 5.--Capt. Lionel M. Woolson, 1931. Chief Aeronautical Engineer, Packard Motor Car Co. Designer of Packard DR-980 diesel engine. (Smithsonian photo A48645A.)] One of the early production versions powered a Bellanca "Pacemaker" which was piloted by Lees and his assistant Frederic A. Brossy to a world's nonrefueling heavier-than-air duration record. The flight lasted for 84 hours, 33 minutes from May 25 through 28, 1931, over Jacksonville, Florida. This event was so important that it was the basis of the following editorial, published in the July 1931 issue of _Aviation_,[7] which summarizes so well the progress made by the diesel engine over a 3-year period and the hope held for its future: A RECORD CROSSES THE ATLANTIC--The Diesel engine took its first step toward acceptance as a powerplant for heavier-than-air craft when, in the summer of 1928, a diesel-powered machine first flew. The second step was made at the 1930 Detroit show, when the engine went on commercial sale. The third was accomplished last month, when a plane with a compression-ignition engine using furnace oil as a fuel circled over the beaches around Jacksonville for 84 hours and inscribed its performance upon the books as a world's record--the longest flight ever made without intermediate refueling. With the passing of the refueling-duration excitement, and with the apparent decision to allow that record to stand permanently at its present level, trials for straight time in the air without replenishment of supplies begin to regain a proper degree of appreciation. No other record, unless it be some of those for speed with substantial dead loads, is of such importance as the non-stop distance and duration marks. No other has such bearing upon precisely those qualities of aerodynamic efficiency, fuel economy, and reliability of airplane and powerplant that most affect commercial usefulness. It is more than three years since the duration record left American shores, and it has been more than doubled in that time. Its return is very welcome. It is doubly welcome for being made with a fundamentally new type of engine. The diesel principle is not a commercial monopoly. It is open to anyone. Already two different designs in America, and one or two in Europe, have been in the air. For certain purposes, at least, it seems reasonable to expect that its special advantages will bring it into widespread use. Every practical demonstration of the progress of the diesel toward realizing its theoretical possibilities in the air as it has realized them on the land and at sea is a bit of progress toward better and more economical commercial flying, and so benefits the whole industry. The fourth, and next, main element in the demonstration will be provided when diesels go into regular service on some well-known transport line as standard equipment, and the accumulation of data on performance under normal service conditions begins. We believe that that will happen before the end of 1932. Many men, from Dr. Rudolf Diesel to Walter Lees and Frederic Brossy, have had direct or indirect hands in the making of this record. The greatest of all contributions was that of Lionel M. Woolson, who created the engine and flew with it in every test and brought it through its early troubles to the point of readiness for the commercial market. The flight that lasted four days and three nights is his memorial, quite as much as is the bronze plaque unveiled last April in the Detroit show hangar. [Illustration: Figure 6.--Stinson SM-1DX "Detroiter." This airplane, powered with original Packard DR-980 diesel engine, made the world's first diesel-powered flight on September 19, 1928. (Photo courtesy of Henry Ford Museum, Dearborn, Michigan.)] [Illustration: Figure 7.--Packard-Bellanca "Pacemaker." This airplane, powered by a Packard DR-980 diesel, holds the world's record for nonrefueling, heavier-than-air aircraft duration flight. The flight lasted 84 hours, 33 minutes, 1-1/4 seconds, and was completed on May 28, 1931, Jacksonville, Florida. (Smithsonian photo A48446B.)] [Illustration: Figure 8.--Verville "Air Coach," October 1930. (Smithsonian photo A48844.)] [Illustration: Figure 9.--Packard-Bellanca "Pacemaker" owned by Transamerican Airlines Corporation and used by Parker D. Cramer, pilot, and Oliver L. Paquette, radio operator, in their flight from Detroit, Michigan, to Lerwick, Shetland Islands, summer 1931. (Smithsonian photo A200.)] [Illustration: Figure 10.--Ford 11-AT-1 Trimotor, 1930, with 3 Packard 225-hp DR-980 diesel engines. Note special bracing for the outboard nacelles. (Smithsonian photo A48311B.)] [Illustration: Figure 11.--Towle TA-3 Flying Boat, 1930, with 2 Packard 225-hp DR-980 diesel engines. (Smithsonian photo A48319.)] [Illustration: Figure 12.--Stewart M-2 Monoplane, 1930, with 2 Packard 225-hp DR-980 diesel engines. (Smithsonian photo A48319C.)] [Illustration: Figure 13.--Consolidated XPT-8A, 1930. This is a Consolidated PT-3A powered by a DR-980 Packard diesel. (Smithsonian photo A48319E.)] The Robert J. Collier Trophy, America's highest aviation award, was won by the Packard Motor Car Company in 1931 for its development of the diesel engine. The formal presentation was made at the White House, March 31, 1932, by President Hoover on behalf of the National Aeronautic Association. Alvan Macauley, president of the Packard Motor Car Company, accepted the trophy, saying: "We do not claim, Mr. President, that we have reached the final development even though our diesel aircraft engine is an accomplished fact and we have the pioneer's joy of knowing that we have successfully accomplished what had not been done before...."[8] The amazing early success of the Packard diesel is illustrated by the following chronological summary: 1927--License agreement signed between Alvan Macauley and Hermann I. A. Dorner to permit designing of the engine. 1928--First flight of a diesel-powered airplane accomplished. 1929--First cross-country flights accomplished. 1930--Packard diesels were sold on the commercial market and were used to power airplanes manufactured by a dozen different American companies. 1931--World's official duration record for nonrefueled heavier-than-air flight. First flight across the Atlantic by a diesel-powered airplane. 1932--Packard diesels tested successfully in the Goodyear nonrigid airship _Defender_.[9] Official American altitude record for diesel-powered airplanes established (this record still stands). In spite of this promising record, the project died in 1933. The December 1950 issue of _Pegasus_ gave two reasons for the failure of the engine: "One blow had already been dealt the program through the accidental death of Capt. L. M. Woolson, Packard's chief engineer in charge of the Diesel development, on April 23, 1930. Then the Big Depression took its toll in research work everywhere and Packard was not excepted." [Illustration: Figure 14.--Walter E. Lees, Packard chief test pilot (in cabin) and Frederic A. Brossy, Packard test pilot, before taking off on their world's record, nonrefueling, heavier-than-air aircraft duration flight, which lasted 84 hours, 33 minutes, and 1-1/4 seconds. (Smithsonian photo A48446E.)] [Illustration: Figure 15.--Walter E. Lees, official timer, and Ray Collins, manager, 1930 National Air Tour, with their official airplane, a Packard diesel Waco "Taper Wing," at Packard proving grounds near Detroit. (Smithsonian photo A49449.)] [Illustration: Figure 16.--Capt. Karl Fickes, acting head of Goodyear's airship operations, pointing out features on one of the "Defender's" Packard diesel engines to Roland J. Blair, Goodyear airship pilot, Akron, Ohio. From "Aero Digest," February 1932. (Smithsonian photo A49674.)] The engine did not fail for the above mentioned reasons. Capt. Woolson's death was indeed unfortunate, but there were others connected with the project who carried on his work for three years after he passed away. The big depression was also unfortunate, but it did not stop aeronautical engine development. "It was a time when such an engine would have been most welcome if it had been produced in large enough numbers to bring the price down to compare favorably pricewise with gas engines of the same horsepower class."[10] The Packard diesel failed because it was not a good engine. It was an ingenious engine, and two of the several features it pioneered (the use of magnesium and of a dynamically balanced crankshaft) survive in modern reciprocating engine designs. In addition, when it was first introduced, no other engine could match it for economical fuel consumption and fuel safety. It also had other less important advantages, but its disadvantages outweighed all these advantages, as will be seen. Description Specifications The following specifications are for the production engine and its prototypes, known as the model DR-980:[11] Type 4-stroke cycle diesel Cylinders 9--static radial configuration Cooling Air Fuel injection Directly into cylinders at a pressure of 6000 psi Valves Poppet type, one per cylinder Ignition Compression--glow plugs for starting--air compression 500 psi at 1000° F. Fuel Distillate or "furnace oil" Horsepower 225 at 1950 rpm Bore and stroke 4-13/16 in. × 6 in. Compression ratio 16:1--maximum combustion pressure 1500 psi Displacement 982 cu in. Weight 510 lb without propeller hub Weight-horsepower ratio 2.26 lb hp Where manufactured U.S.A. Fuel consumption .46 lb per hp/hr at full power Fuel consumption .40 lb per hp/hr at cruising Oil consumption .04 lb per hp/hr Outside diameter 45-11/16 in. Overall length 36-3/4 in. Optional accessories Starter--Eclipse electric inertia; 6 volts. Special series no. 7 Generator--Eclipse type G-1; 6 volts [Illustration: Figure 17.--Longitudinal cross section, Packard diesel engine DR-980. (Smithsonian photo A48845.)] [Illustration: Figure 18.--Transverse cross section, Packard diesel engine DR-980. (Smithsonian photo A48847.)] [Illustration: Figure 19.--Right side view of engine, showing accessories; Packard Motor Car Co. 50-hour test, 1930. A, starter; B, oil filter. (Smithsonian photo A48323.)] [Illustration: Figure 20.--Rear left view of engine, showing accessories, U.S. Navy 50-hour test, 1931. Barrel valve type venturi throttles. A, starter; B, oil filter; C, fuel circulating pump; D, generator. (Smithsonian photo A48324C.)] Operating Cycles The sequences of operation of a Packard diesel engine compared with those of a 4-stroke cycle gasoline engine are illustrated in figure 21. [Illustration: =Brief Analysis of Action in a Four-Cycle Gasoline Engine= _Mixture of air and gasoline enters cylinder from carburetor._ _Mixture is compressed into smaller volume by piston moving upward._ _An electric spark ignites the compressed mixture causing it to explode._ _Combustion heat increases the cylinder pressure forcing piston downward._ _Momentum carries piston upward which pushes burnt gases out through the exhaust valve._ =Similar Action in the Packard-Diesel Aircraft Engine= _Atmospheric air only, enters cylinder through single valve._ _Air is so greatly compressed by upward moving piston that it reaches temperature of 1000° F._ _Just before piston is at dead center fuel oil is sprayed into cylinder and spontaneously ignited._ _Power of this explosion is passed to crankshaft in conventional manner._ _Piston forces out burnt gases through same single valve which is cooled by inrush of new air as cycle repeats._ Figure 21.--Operating cycles. (Smithsonian photo A48846.)] Although the size, weight, and general arrangement of the Packard diesel did not differ radically from conventional gasoline engines of a similar type, there were definite differences caused by the diesel cycle. In the words of Capt. Woolson:[12] As this engine operates on an entirely different principle than the gasoline engines used heretofore in aircraft, it is desirable before launching into a mechanical description to consider first in a general way the principles of operation of the Diesel cycle as opposed to the Otto cycle principle on which nearly all gasoline engines operate. The real point of departure between the two systems of operation is the ignition system involved. In the gasoline engine an electric spark is depended upon to fire a combustible mixture of gasoline vapor and air which mixture ratio must be maintained within rather narrow limits to be fired by this method.... In the Diesel engine, air alone is introduced into the cylinders, instead of a mixture of air and fuel as in the gasoline engine, and this air is compressed into much smaller space than is possible when using a mixture of gasoline and air, which would spontaneously and prematurely detonate if compressed to this degree. The temperature of the air in the cylinder at the end of the compression stroke of a Diesel engine operating with a compression ratio of about 16:1 is approximately 1000 degrees Fahr., which is far above the spontaneous-ignition temperature of the fuel used. Accordingly, when the fuel is injected in a highly atomized condition at some time previous to the piston reaching the end of its stroke, the fuel burns as it comes in contact with the highly heated air, and the greatly increased pressures resulting from the tremendous increase in temperature brought about by this combustion, acting on the pistons, drive the engine, as in the case of the gasoline engine. Summing up, the differences between the Diesel and gasoline engines start with the fact that the gasoline engine requires a complicated electrical ignition system in order to fire the combustible mixture, whereas the Diesel engine generates its own heat to start combustion by means of highly compressed air. This brings about the necessity for injecting the fuel in a well-atomized condition at the time that combustion is desired and the quantities of fuel injected at this time control the amount of heat generated; that is, an infinitesimally small quantity of fuel will be burned just as efficiently in the Diesel engine as a full charge of fuel, whereas in the gasoline engine the mixture ratio must be kept reasonably constant and, if the supply of fuel is to be cut down for throttling purposes, the supply of air must be correspondingly reduced. It is this requirement in a gasoline engine that necessitates an accurate and sensitive fuel-and-air metering device known as the carburetor. The fact that the air supply of a Diesel engine is compressed and its temperature raised to such a high degree permits the use of liquid fuels with a high ignition temperature. These fuels correspond more nearly to the crude petroleum oil as it issues from the wells and this fact accounts for the much lower cost of Diesel fuel as compared to the highly refined gasoline needed for aircraft engines. Weight-Saving Features In order to be successful in aviation use, the modern lightweight diesel of the time had to have its weight reduced from 25 lb/hp to 2.5 lb/hp. This required unusual design and construction methods, as follows: Crankcase: It weighed only 34 lb because of three factors: Magnesium alloy was used extensively in its construction, thus saving weight as compared with aluminum alloy, which was the conventional material at this time. It was a single casting. This saved weight because heavy flanges, nuts, and bolts were dispensed with. The cylinders, instead of being bolted to the crankcase, as was normal practice, were held in position by two circular hoops of alloy steel passing over the cylinder flanges. They were tightened to such an extent that at no time did the cylinders transfer any tension loads to the crankcase. This type of fastening actually strengthened the crankcase in contrast to the usual method. For this reason it could be built lighter. The hoops did not always function well. "The first job I ever did on the Towle was to patch the holes in the top and bottom of the hull when a cylinder blew off during run-up and nearly beheaded the pilot."[13] [Illustration: Figure 22.--Rear view of engine with rear crankcase cover removed, showing valve and injector rocker levers and injector control ring mounted on crankcase diaphram. U.S. Navy test, 1931. (Smithsonian photo A48323D.)] [Illustration: Figure 23.--Main crankcase. U.S. Navy test, 1931. (Smithsonian photo A48325B.)] [Illustration: Figure 24.--Rear crankcase cover and gear train: crankshaft gear drives B, which drives oil pump at F. A, integral with B, drives internal cam gear. B also drives C on fuel-circulating pump. D, driven by crankshaft gear, drives E on generator shaft. U.S. Navy test, 1931. (Smithsonian photo A48325C.)] [Illustration: Figure 25.--Master and link connecting rods. U.S. Navy test, 1931. (Smithsonian photo A48323A.)] [Illustration: Figure 26.--Crankshaft with automatic-timing retarding device on rear end of pivoted- and spring-mounted counterweights. U.S. Navy test, 1931. (Smithsonian photo A48323B.)] [Illustration: Figure 27.--Propeller hub and vibration damper. U.S. Navy test, 1931. (Smithsonian photo A48325A.)] Crankshaft: Since this engine developed the high maximum cylinder pressure of 1500 psi, it was necessary to protect the crankshaft from the resulting heavy stresses. Without such protection the crankshaft would be too large and heavy for practical aeronautical applications. Although the maximum cylinder pressures were 10 times as great as the average ones, they were of short duration. The method of protecting the crankshaft took full advantage of this fact. It consisted of having the counterweights flexibly mounted instead of being rigidly bolted, as was common practice. The counterweights were pivoted on the crank cheeks. Powerful compression springs absorbed the maximum impulses by permitting the counterweights to lag slightly, yet forced them to travel precisely with the crank cheeks at all other times. Propeller Hub: The propeller is, of course, subject to the same stresses as the crankshaft. Instead of being rigidly bolted to the shaft as was common practice, it was further protected from excessive acceleration forces by being mounted in a rubber-cushioned hub. This permitted the use of a lighter propeller and hub. Valves: A further weight saving resulted from the use of a single valve for each cylinder instead of two as in the case of conventional gasoline aircraft engines. (A diesel engine designed in this manner loses less efficiency than a gasoline one because only air is drawn in during the intake stroke.) In addition to the weight saving brought about by having fewer parts in the valve mechanism, there was an additional advantage since the cylinder heads could be made considerably lighter. [Illustration: Figure 28.--Cylinder disassembly, showing valve and fuel injector. U.S. Navy test, 1931. (Smithsonian photo A48324D.)] Diesel Cycle Features Although Woolson designed the ingenious weight-saving features, Dorner was responsible for the engine's diesel cycle which employed the "solid" type of fuel injection. In order to understand Dorner's contribution, a brief description of the type of diesel injection pioneered by Dr. Rudolf Diesel is necessary. His system injected the fuel into the cylinder head with a blast of air supplied by a special air reservoir at a pressure of 1000 psi or more. Known as the "air blast" type of injection it produced good turbulence, with the fuel and air thoroughly mixed before being ignited. Such mixing increases engine efficiency, but it involves the provision of bulky and costly air-compressing apparatus which can absorb more than 5 percent of the engine's power. Naturally the compressor also adds considerably to the engine's weight. In contrast to this, a "solid" type of fuel injection may be employed to eliminate the complications of the "air blast" system. It consists of injecting only fuel at a pressure of 1000 psi or more. Air is admitted by intake stroke, as with a gasoline engine. Turbulence is induced by designing the combustion chamber and piston so as to give a whirling motion to the air during the intake stroke. The following quotation from Dorner now becomes readily understandable. "Since 1922 my invention consisted in eliminating the highly complicated compressor and in injecting directly such a highly diffused fuel spray so that a quick first ignition could be depended upon. By means of rotating the air column around the cylinder axis, fresh air was constantly led along the fuel spray to achieve completely sootless burning-up.... In 1930 I sold my U.S.A. patents to Packard."[14] Valve Ports: The inlet port (which was also the exhaust port) was arranged tangentially to the cylinder. This design imparted a very rapid whirling motion to the incoming air, thereby aiding the combustion process. Engine efficiency and rpm were both increased. Fuel Injector Pumps: A combination fuel pump and nozzle was provided for each cylinder in contrast to the usual system of having a multiple pump unit remotely placed with regard to the nozzles. The former system was adopted after frequent fuel-line failures were experienced due to the engine's vibration. Woolson stated that his system prevented pressure waves, which interfered with the correct timing of the fuel injection, from forming in the tubing. Leigh M. Griffith, vice president of Emsco Aero, writing in the September 1930, _S.A.E. Journal_ stated: "Regarding the superiority claim for the simple combination of fuel pump and injection valve into one unit, without connecting piping, the author entirely overlooks the fact that the elasticity of a pipe and its contained fuel can be important aids in securing that extremely abrupt beginning and ending of injection which is so desirable." [Illustration: Figure 29.--Fuel-injector disassembly. U.S. Navy test, 1931. (Smithsonian photo A48323C.)] A major advantage obtained from combining the fuel pump and injection valve is the ability of an engine so equipped to burn a wide variety of fuels. The elimination of the above-mentioned type of high-pressure tubing reduces the possibility of a vapor lock occurring, thereby permitting more volatile fuels to be burned. This increases the range of hydrocarbon fuels the engine can utilize. It could run on any type of hydrocarbon from gasoline to melted butter.[15] Another reason for combining the fuel pump and injection valve is given by P. E. Biggar in _Diesel Engines_ (published in 1936 by the Macmillan Company of Canada Ltd., Toronto): "In the Dorner pump, for example, the stroke of the plunger is changed by using a lever-type lifter and moving the push-rod along the lever to vary its movement. Unfortunately, in all arrangements of this sort, the plunger comes to a reluctant and weary stop, as the roller of the lifter rounds the nose of the cam. When the movement does finally end, the injection does not necessarily stop, as the compressed fuel in the injection pipe is still left to dribble miserably into the combustion chamber. To minimize this defect, the designer has placed the pump and injector together in a single unit." [Illustration: Figure 30.--Mechanism for retarding valve and fuel-injection timing during starting (see also fig. 26). U.S. Navy test, 1931. (Smithsonian photo A48324E.)] [Illustration: Figure 31.--Upper--valve and fuel injector cam; lower--fuel-injector cam used for starting. U.S. Navy test, 1931. (Smithsonian photo A48325.)] Starting System: On November 1, 1961, C. H. Wiegman, vice president of engineering of the Lycoming Division of Avco Corporation wrote to the Museum in part as follows: Early in the development it became quite evident that cold starting was a problem. This was finally worked out by Packard through the use of glow plugs and speeding up the injectors during the cranking period. It had been felt that during the slow cranking process we were not vaporizing the fuel through the nozzles and that if we could speed up the injection pumps during this period of cranking a better vaporization could be obtained. Our tests showed that we were right, and that the engine could be started quite easily at minus 10° F through the use of glow plugs. The method used for speeding up the injection pumps was accomplished by utilizing a crankshaft cam during the cranking period. The starter would shift the running cam out of position allowing the crankshaft cam to take over. After the engine fired, the starter was disengaged and the running injector pump cam would assume its original position. The starting cam would be run at engine speed during cranking, and the running cam at 1/8 reverse engine speed during engine operation. The shifting was accomplished by a pin-in-slot and spring arrangement to change the indexing of the cams to starting position and return. An Eclipse electric starter with an oversized flywheel was used.... This was powered by a double-sized battery. Development Air Shutters: The first engines had no provision for throttling the intake air. This allowed the engine to run on its own lubricating oil when the throttle was in idle position. As a result the engine idled too fast, thereby causing either excessive taxiing speeds or rapid brake wear. This inability to idle slowly also caused high landing speeds since the propeller did not turn slowly enough to act as an airbrake. Figure 1 shows the first model. Note that the tubular air intakes on top of the cylinders have no valves. Figure 32 shows a later model. Note the butterfly valves in the U-shaped air intakes. Here they are shown fully opened. When the throttle was placed in idle position these valves automatically closed and prevented air from flowing past them. Air could then only enter from the back of the intakes. Since less air could flow into the cylinders, the force of their explosions was reduced, which, in turn, lowered the idling revolutions per minute. Figure 28 shows a cylinder from a more advanced model. Note the circular opening between the air intake and the intake/exhaust housing. A barrel type of valve fitted into this opening. One of these valves can be seen just below and to the left of the cylinder. When the throttle was placed in idle position this valve rotated to a position which cut off almost all of the airflow into its cylinder. This increased the vacuum formed toward the end of the intake stroke, thereby causing more resistance, which reduced the idling rpm to that of a gasoline engine.[16] [Illustration: Figure 32.--Front left view of engine from Packard Motor Car Co. 50-hour test, 1930, showing butterfly valve type venturi throttles. (Smithsonian photo A48325E.)] [Illustration: Figure 33.--Front left view of engine from U.S. Navy test, 1931, showing spiral oil cooler. (Smithsonian photo A48324A.)] Crankcase: It was strengthened by having external ribs added. Note the contrast between the first engine, figure 2, and a later model, figure 32. Oil Cooler: The drum-shaped honeycombed cooler was replaced by a spiral pipe type located between the engine cowl and the crankcase. Figure 3 shows an example of the former type of cooler located at the top of the engine between two of the cylinders. Figure 33 illustrates the latter type located between the cowling and the crankcase. Cylinder Fastening: Early models had their cylinders strapped and bolted to the crankcase. Later ones had them only strapped. Figure 2 shows a bolt-fastened clamp between two of the cylinders on the first engine. Figure 19 shows a later model without any bolts holding down the cylinders. Pistons: The pistons used in the 1929 engine had one compression ring and one oil scraper ring above the piston pin, and one oil scraper ring below it. There were three grooves, two above the piston pin, and one below it.[17] Pistons used in 1930 had two compression rings, one oil scraper ring above the piston pin, and one oil scraper ring below it. There were four grooves, three above the piston pin, and one below it.[18] The 1931 pistons had one compression ring above the piston pin, and one compression ring and four oil scraper rings below it. There were four grooves, one above the piston pin, and three below it.[19] [Illustration: Figure 34.--Modified pistons after endurance run. U.S. Navy test, 1931. (Smithsonian photo A48325D.)] Combustion Chamber: In 1931 the contour of the cylinder head was changed slightly. This improved the combustion efficiency to the extent that the stroke of the fuel pumps could be decreased about 15 percent. The specific fuel consumption then decreased about 10 percent. In addition the compression ratio was reduced from 16:1 to 14:1.[20] These changes were designed to eliminate smoke from the exhaust at cruising speed, and to reduce it at wide-open throttle. Valves: A two-valve-per-cylinder model was built, but not put into production. It featured more horsepower (300), a higher rate of revolutions per minute (2000), and a better specific fuel consumption (about .35 lb/hp/hr).[21] Capt. Woolson designed the production model with a single large valve for each cylinder. This was done in order to shorten the development period, for it is easier to design a single valve which serves both the intake and exhaust functions than one valve for each function. Not only are there fewer parts, but more important, there are no heat-dissipating problems. Although the single valve is heated when it releases the exhaust gases, it is immediately cooled by the incoming air of the next cycle. This cooling advantage is not shared by a valve which only passes exhaust gases.[22] Cylinder Head: Ribs were added to increase its rigidity (compare fig. 32 with fig. 33). Engine Size: A 400-hp model was developed in 1930. It was not put into production.[23] Comments Comments of Aeronautical Engineers: These comments appeared in _Aviation_ for February 15, 1930, just a month before the Packard diesel received its approved-type certificate. They were in answer to the question, "What is your opinion of the probable early future of the compression ignition type of engine in aircraft powerplants?" Most of the engineers were enthusiastic about the diesel engine's future in aviation; however, neither George J. Mead nor C. Fayette Taylor shared their colleagues' opinions. Mead's prophesy was accurate except for his discounting the diesel's role in lighter-than-air craft. Taylor was correct in implying that there was a future for the diesel in powering airships. George J. Mead (vice president and technical director, Pratt & Whitney Aircraft Company): Compared with the present Otto cycle engine, the Diesel powerplant weight, including fuel for a long-distance flight, would apparently be less. It is doubtful whether there would be any saving if the orthodox engine were operated on a more suitable fuel. Inherently the Diesel engine must stand higher pressures and therefore is heavier per horsepower. A partial solution of this difficulty is the two-cycle operation, which seems almost a requirement if the Diesel cycle is to be considered at all for aircraft. For any normal commercial operation in the United States there seems to be little or no improvement to be had from the Diesel. After all, it is not entirely a question of fuel cost but payloads carried for a given horsepower. It seemed at one time as though the Diesel was particularly desirable for Zeppelin work. Now that blau gas has been introduced, which obviates the need of valving precious lifting gas, the Diesel cycle seems much less interesting for this purpose. There may be a reduction in fire hazard and radio interference with the Diesel cycle, but it is doubtful whether it will be used in view of these considerations alone. C. Fayette Taylor (professor of aeronautical engineering, Massachusetts Institute of Technology): "I believe that the compression ignition engine will continue to remain in the experimental stage during the year 1930. I should expect its first really practical installation to be in lighter-than-air craft." P. B. Taylor (acting chief engineer, Wright Aeronautical Corporation): "I believe the compression ignition engine is probably the type which will eventually supersede the present electric ignition units. This development will come slowly and will not be a solid injection engine." Henry M. Mullinnix (former chief of powerplant section, Navy Bureau of Aeronautics): The advantages of compression-ignition, including reduced fire hazard, more efficient cycle, elimination of electrical apparatus and hence of radio interference, elimination of carburetion problems, and other benefits less evident, would seem to outweigh the difficulties encountered in metering and injecting minute quantities of fuel at the proper instant. Although the Diesel engine suffers upon comparison with the Otto cycle engine in flexibility there seems to be a definite field for employment of Diesels and a gradual extension of their use may be predicted. John H. Geisse (chief engineer, Comet Engine Corporation): "I am firmly convinced that the Diesel engine in the future will not only maintain the advantages of Diesel engines as they are now known, but will also be lighter in pounds per horsepower than the present Otto engines." Lt. Cdr. C. G. McCord (U.S. Navy, Naval Aircraft Factory): "The use of compression ignition in due time appears to be assured; but increase in weights above those of present Otto cycle engines, to insure reliability, must be expected." L. M. Woolson (aeronautical engineer, Packard Motor Car Company): "There is no question that the compression ignition aircraft engine will in time offer severe competition to the gasoline engine. There are, however, many basic problems to be solved for the solution of which there exists no precedent." N. N. Tilley (chief engineer, Kinner Airplane and Motor Corp.): Considerable development of the compression ignition type of engine for aircraft will be required before it is commonly available. It is believed that the weight per horsepower must be equal to, or less than, that of the present type of engines, in order to interest the public, since rapid take-off, rate of climb, and speed are desired, rather than low fuel consumption or high mileage. Most flights are of few hours duration. It is believed that flights must be of over five or six hours duration in order to show any advantage of Diesel engines (with low fuel consumption) if appreciably heavier than present engines. Also the difference between Otto cycle and Diesel becomes slight as the compression ratios come closer together. Comments of Flight Crews: The preceding comments were made by engineers thinking primarily of the commercial possibilities of the diesel. Following are comments by flight crewmembers about the operating characteristics of the Packard diesel. The former were largely optimistic. Most of them were only familiar with the aeronautical diesel as a design project and therefore did not have the practical experience necessary to understand all of its limitations. The latter were pessimistic, as they knew firsthand various shortcomings of the engine which only became apparent when it was operated. Clarence D. Chamberlin, pioneer pilot: My only experience with the Packard diesel was in a Lockheed "Vega" which I owned back about 1932. The Wright J-5 had been replaced with the 225 hp Packard Diesel. My main complaint was the excessive fumes. When I would come home at night my wife would greet me with, "You have been flying that oil burner again." It was so bad that passengers' clothing would smell like a smoky oil stove for hours after a flight. Looking backward, it is my guess that the Diesel would have had only a limited period of acceptance even if all mistakes had been avoided. It is easier and cheaper to get performance with lighter and more powerful engines and longer runways than by refining the airplane. Fuel economy of an engine has ceased to be the deciding factor. Higher utilization of a high speed Jet at least in part offsets the inefficient use of fuel. The only time the Diesel had a chance was from the middle 20's perhaps on thru WW-2 for certain things due to gasoline shortage. To sum it up, the thing that licked them worst was the use of a single valve for inlet and exhaust making it impossible to collect and keep the fumes out of the fuselage.[24] Ruth Nichols, prominent aviatrix: I was flying Chamberlin's diesel-powered Lockheed, in which a month before I had made an official altitude record for both men and women in aircraft powered by an engine of that type. The record, I believe, still holds. It was a rugged, dependable plane whose experimental oil-burning engine nevertheless had a number of bugs. For one thing, it was constantly blowing out glow-plugs used for warming the fuel mixture, and when that happened long white plumes of smoke would stream out, giving spectators the impression that the ship was on fire. For another, the vibration was so bad that out of 10 standard instruments on the plane, 7 were broken from the jarring before my return. The diesel fuel also produced a strong odor in the cockpit, the fumes so permeating my luggage and clothes that my public appearances during the tour always were highly and not very agreeably aromatic. Having a strong stomach, I soon became accustomed to the fumes, but another pilot who ferried the plane between cities for me on one occasion ... was almost overcome. On arrival he said, "I wouldn't fly that oil burner another mile."[25] [Illustration: Figure 35.--Ford 11-AT-1 Trimotor, 1930, with 3 Packard 225-hp DR-980 diesel engines, right side view of right engine nacelle. (Smithsonian photo A48311.)] Richard Totten,[26] airplane mechanic: The Ford Trimotor was the poorest of the lot. It was inherently noisy and slow, and with the Packards installed it was on the point of being underpowered. It was almost impossible to synchronize the three engines, and the beat was almost unbearable. It was not flown much but it made a fine conversation piece standing on the airport apron.... The Waco taperwing developed the unnerving habit of breaking flying and landing wires from the vibration, and most of the time sat on the hangar floor with its wings drooping like a sick pigeon. In flight the open cockpit filled with exhaust smoke and unburned fuel and the pilot would land after an hour's flight looking like an Indianapolis 500 Mile Race driver.... The Stinson "Detroiter," the Bellanca "Pacemaker" and the Buhl-Verville "Airsedan" were the most successful ships and were the most used. The "Airsedan," in which Woolson was killed, was his favorite ship, and the one I believe that was the most flown. The Towle TA-3 amphibian flew beautifully, but not for long. It never got a chance to do much as it was a victim of the depression. The Towle was powered by 2 Packard diesels on loan from the Packard Motor Car Company. It was built of corrugated aluminum exactly like the Ford Trimotor. As a matter of fact, Towle had been employed by Ford until Ford cancelled airplane building. Towle got his airplane built at the hangar on Grosse Isle in Detroit, and ran out of money during the flight testing program. He now looked for money to continue with and found a backer in the person of one Doctor Adams, a widely advertised "Painless Dentist" of Detroit. Adams wanted a quicker return on his money than the average backer and he insisted that Towle put the airplane in service so it could start earning some money. At this time the amphibian was beginning to become popular for intercity flying, especially around the Great Lakes region as all of the major cities were located on the waterfront. What was more natural than an airline flying passengers right into the downtown area of a city? Thompson was doing it between Detroit and Cleveland, Marquette was doing it between Detroit and Milwaukee, so Adams applied for permission to operate an airplane between Detroit and Cleveland and other cities on the lakes. In those days it was necessary to prove an airplane's reliability by flying a certain number of trips over the proposed route with a simulated payload. This payload was supposed to consist of sand bags, but usually consisted of any mechanic or pilot who happened to be loose at the moment, and who had nerve enough to go along. Mechanics were easier to load and unload than sand bags. The Towle was in the middle of the qualification flights, and the publicity began to appear about the new airline. Much newsprint was devoted to the fact that the Towle was powered by the new Packard diesel engine, and this, of course, made it the only safe airline since all its competitors were using the old-fashioned dangerous gasoline. On the last payload trip of the Towle the pilot asked me if I wanted to go along, and of course I was delighted. I neglected to mention that I had been hired by the Adams airline as a mechanic because of my experience in repairing the corrugated skin of the Ford Trimotor owned by my employer, the Knowles Flying Service. The mere fact that I did many repairs to the airframe did not preclude me from getting my share of the engine work too, and since I was already familiar with the Packard diesel, I was quickly hired by Dr. Adams. The last flight was indeed the last flight. We took off from the Detroit City Airport and when we crossed the Detroit river the pilot decided to land at the Solvay Coal Company docks and fuel up for the opening of the airline the next day. The Solvay Coal Company was the only place in Detroit where diesel fuel was obtainable at the time and all of the diesel powered yachts got fuel there. The pilot was not too experienced in the operation of amphibians, and he put the wheels down as we approached the river. When we hit the water the airplane went over on its back and sunk to the bottom. It came up to the surface again, and we all climbed out onto the keel, and waited for rescue. A police boat came over and took us to the dock. The police sent us to the hospital and then went back and towed the airplane over to the shipyard next door to Solvay. While we were at the hospital, the crane man hooked onto the Towle and lifted it out of the water and gently set it down on the dock. He was only trying to help, but he inadvertently set it down on its back instead of its wheels. That was the end of the Adams airline. The Packard Company took back their engines. I helped remove them the next day. We dismantled the airplane and trucked it back to the airport where it sat in a state of neglect for some time. The pilot was fired, I lost my job, and Towle lost his airplane. Analysis Advantages A Packard diesel advertisement which appeared in _Aero Digest_ for June 1930 stated that this engine had three major advantages over its gasoline rivals: Greater reliability because of extreme simplicity of design; greater economy because of lower fuel cost plus lower fuel consumption, permitting greater payloads with longer range of flight; and greater safety because of removal of the fire hazard through the use of fire-safe fuel and absence of electrical ignition equipment. These were the engine's principal advantages. Others are analyzed here by the author in order of their importance. At low altitudes the diesel uses an excess of air to eliminate a smoking exhaust; consequently at high altitudes, where the air is less dense, the diesel is still able to maintain much of its power. In contrast, the carburetored gasoline engine is sensitive to the fuel-air ratio and thus has no surplus air available at higher altitudes. A malfunctioning carburetor could cause a gasoline engine to cease operating, but an inoperative fuel injector would cause the Packard diesel to lose one ninth of its power, since each cylinder had its own independently operating injector. In practice, however, because of the excessive vibration, the engine was generally shut off immediately after a cylinder cut out.[27] Shielding was unnecessary because the diesel had no electrical ignition system. Carburetor icing was an impossibility because there was no carburetor. Any excess lubricating oil in a diesel engine's cylinder is consumed cleanly to produce power. By contrast, such oil in a gasoline engine's cylinder is only partly burned. As a result carbon deposits form that eventually cause malfunctioning of the spark plugs, valves, and combustion chambers. This advantage accrued to the diesel because it utilized an excess of air, and in addition its cylinder walls were hotter. The engine was very clean-running from the standpoint of oil leakage. This was a safety factor since it eliminated the possibility of a fire starting on the outside surfaces of the engine, and in addition it saved the time and money that was normally spent cleaning engines.[28] Since the diesel utilized its heat of combustion more efficiently than the gasoline engine, its cooling fin area could be reduced by 35 percent. This permitted better streamlining. Having less cooling fin area, it warmed up more rapidly than a gasoline engine. [Illustration: The PACKARD-DIESEL AIRCRAFT ENGINE Fire-Safe Fuel _Furnaces in many a home burn similar oil_ _A lighted match cannot ignite or explode it_ _Saturated cloth can burn only like a wick_ _And the oil itself will quench this fire_ _But only when property atomized the spray may be ignited_ Graphic Proof of fuel safety in the Packard-Diesel Aircraft Engine Figure 36.--Advertisement emphasizing the advantages of fire-safe fuel. (Smithsonian photo A48848.)] Due to the greater simplicity, it was more practical to build a large diesel than a large gasoline engine. Large airplanes would therefore need fewer engines if diesel powered. Smaller fuel tanks could be used because of the greater fuel economy of the diesel, and also because of the high specific gravity of fuel oil as compared to gasoline. Furthermore, these smaller tanks could be placed in more convenient locations. Not having a carburetor the engine could not backfire, further reducing the fire hazard. The exhaust note was lower because of the diesel's higher expansion ratio. The absence of an ignition system permitted the diesel to operate in the heaviest types of precipitation. Such conditions might cause the ignition system of a gasoline engine to malfunction. The Packard diesel was flown at times without exhaust stacks or manifolds; this was practical from a safety standpoint because of the diesel's lower exhaust temperature due to its higher expansion ratio. Elimination of these parts reduced the weight and cost of the engine installation. Finally, the engine was ideal for aerobatics, since the injectors, unlike carburetors, would work equally well whether right side up or upside down. An advantage peculiar to the Packard among aeronautical diesels was its light weight. The English Beardmore "Tornado III" weighed 6.9 lb/hp, and the German Junkers SL-1 (FO-4) weighed 3.1 lb/hp, while the Packard weighed but 2.3 lb/hp. In fairness to the Beardmore, it was the only one of the three engines designed for airship use, and part of its heaviness was due to the special requirements of lighter-than-air craft. A contemporary and comparable American gasoline engine, the Lycoming R-680, weighed 2.2 lb/hp. To have designed a diesel aircraft engine as light as a gasoline one was a remarkable achievement. Disadvantages There are four main reasons why the Packard diesel was not successful. First the Packard Motor Car Company put the engine into production a brief three years after it was created. The only successful airplane diesel, the German Junkers "Jumo," was in development more than three times as long (1912-1929). The following tests indicate that the Packard diesel was not ready for production, and hence was unreliable. Packard Motor Car Company 50-Hour Test (Feb. 15-18, 1930): This test was identical to the standard Army 50-hour test which was used for the granting of the Approved Type Certificate. The engine tested was numbered 100, and was the first to be made with production tools (approximately half a dozen engines had been handmade previously). It had to be stopped three times, twice due to failure of the fuel pump plunger springs and once due to the loosening of the oil connection ring. These failures were attributed to manufacturing discrepancies. In addition, 4 out of a total of 103 valve springs broke.[29] U.S. Navy 50-Hour Test (Jan. 22, 1931, to March 15, 1931): The engine used in the Navy test was numbered 120. (Apparently only 20 production engines had been built during the preceding 12 months; Dorner in a letter of March 3, 1962, states that the total number of Packard diesels produced was approximately 25.) The engine had to be stopped three times, twice due to valve-spring collar failures and once due to a valve head breaking. Because of these failures this test was not completed. The following significant quotations have been extracted from the test: "The engine is not recommended for service use.... Flight tests, until the durability of the engine is improved, be limited to a determination of the critical engine speeds, and to short hops in seaplanes.... It is believed that this size engine should be made suitable for service use before this type in a larger class is attempted." This latter statement probably refers to the 400-hp model. A year had passed between the making of engine 100 and 120, yet the reliability had not improved. Although unreliability was the immediate cause of failure, there were two design defects which would have doomed the engine even if it had been reliable. All the Packard diesels were of the 4-stroke cycle unblown type, yet the most successful airplane diesels were of the 2-stroke cycle blown type.[30] The advantages of the latter type for aeronautical use are that it is of a more compact engine, of lower weight and greater efficiency.[31] The engine was therefore built around the wrong cycle. The Packard diesel of 1928 was designed to compete with the Wright J-5 "Whirlwind" which powered Lindbergh's "Spirit of St. Louis" in 1927.[32] The specifications were within two percent of each other. The diesel engine's fuel consumption was far less although its price was considerably higher. _Packard Diesel_ _Wright J-5_ _DR-980_ _"Whirlwind"_ Diameter (in.) 45-11/16 45 Horsepower 225 225 Weight (lb) 510 510 Weight-horsepower ratio 2.26 2.26 Fuel consumption (lb per hp/hr at 0.40 0.60 cruising). Cost $4025 $3000 The advantages of lower fuel cost and greater cruising range offered by the diesel engine would be relatively unimportant to a private pilot flying for pleasure, but would be vital to the commercial operator using airplanes powered by engines having several times the horsepower of the Packard diesel. Its size, moreover, was too small for the technology of fuel injectors.[33] The Packard Company realized that the production engine was too small.[34] In 1930 a 400-hp version was built but was not put into production, probably because of the unreliability of the 225-hp model. The fourth principal reason why the engine failed is explained by the following quotation from _The Propulsion of Aircraft_, by M. J. B. Davy (published in 1936 by His Majesty's Stationery Office, London): Although the development and adoption for transport purposes of the relatively high-speed compression ignition engine has been rapid during the last few years, there has been no corresponding advance in its adoption for aircraft propulsion. A reason for this is the recent great advance in "take-off" power in the petrol (gasoline) engine due to the introduction of 87 octane fuel (which permits higher compression ratios) and the strong probability of 100 octane fuels in the near future, still further increasing this power. The need for increased take-off power results from the higher wing loading necessitated by the modern demand for commercial aircraft with higher cruising speeds with reasonable power expenditure. Production of the Packard diesel ceased in 1933. During that same year the Pratt & Whitney Aircraft Company and the Wright Aeronautical Corporation specified 87-octane fuel for certain of their engines. Less than 10 years later octane ratings had increased to over 100, putting the diesel at a further disadvantage.[35] Although the above disadvantages sealed the Packard diesel's fate, there were other minor reasons for its failure. The Packard diesel had the highest maximum cylinder pressure (up to 1500 psi at peak rpm) of any proven contemporary aircraft diesel engine. Leigh M. Griffith, vice president and general manager, Emsco Aero Engine Company, had this to say about the Packard diesel's high maximum cylinder pressure in the September 1930 _S.A.E. Journal_: The designers considered it necessary to adopt unusual but admittedly clever expedients to counteract the great torque irregularity caused by the excessive maximum pressure. The adoption of the lower pressure of 800 lbs. would have eliminated the necessity for the pivoted spring-mounted counterweights and the shock-absorbing rubber propeller-drive.... The use of such high pressures is in reality the quick and easy way to secure high-speed operation and can be justified only from this standpoint, although the resulting increased difficulty in keeping the engine light enough was a strong offsetting factor.[36] Insofar as the engine life was concerned it is true that 1,500-psi peak pressures were observed but the engine was so developed to withstand these pressures.... One of the most severe problems connected with the development of this engine was the piston ring sealing. Special compression rings were made with no gaps and further work in this respect could have been used to advantage had the engine been kept in production.[37] It is significant that in 1930 the Packard diesel had a compression ratio of 16:1, whereas in 1931 it has been reduced to 14:1. This was probably done to reduce vibration and the problem of piston-ring sealing.[38] The exhaust products had an unpleasant odor which was particularly objectionable during taxiing. Professor C. Fayette Taylor, writing in the January 1931 issue of _Aviation_, remarked about this fault: "One is inclined to question whether the disagreeable escaping of exhaust gas from the intake ports can be overcome, while still retaining the obvious advantages in weight and simplicity of the single valve." The engine exhaust deposited a black oily film. In fact some airplanes fitted with the Packard diesel engine were painted black, so that soot deposits from the exhaust would not be noticed.[39] Since the passengers' and pilots' compartments were generally located behind the engines, and were not airtight, damage to clothing resulted. This fault could have been eliminated by the use of separate valves for the intake and exhaust systems. It was not possible to start the engine when the temperature dropped much below 32° F unless glow plugs were used. These spark-plug-like devices, which were only used for starting, had resistance windings which glowed continuously when turned on. The additional heat glow plugs provided made starting an easy matter in the coldest weather; however, they complicated the design of an engine noted for its simplicity, and they used so much electricity that only a long flight would allow the generator to fully recharge the battery. H. R. Ricardo, writing in the June 4, 1930, issue of _The Aeroplane_ said: "Referring to the very fine achievement of the Packard Company of America in producing a small radial air-cooled heavy-oil engine, a petrol engine of similar design and with the same margin of safety would weigh less than 1-1/2 lbs. per hp." The important point made is that a gasoline engine designed along the same lines as the Packard diesel would weigh considerably less, but would then suffer from the Packard's reduced structural safety factor. It is significant that as the Packard developed, it became heavier.[40] Like other diesels, the Packard cost more to build than a comparable gasoline engine, because of the type of construction required for the diesel's higher maximum cylinder pressures and the difficulty of machining the fuel injectors. Having fuel injectors, the engine was more sensitive to dirt in the fuel system than a carburetor-equipped gasoline engine.[41] The fuel injectors were "a crude and deficient mechanism" subject to rapid wear, and often these injectors caused smoking exhausts and high fuel consumptions.[42] In the event of battery or starter failure, a comparable gasoline engine could be started by swinging the propeller. Because of the engine's high compression, it would have been impossible to have hand-started a Packard diesel this way. In a letter to the Air Museum, January 15, 1962, Dorner commented: "During my first demonstration (of high-speed diesel engines) in 1926 in California and later in Detroit I learned from Capt. Woolson that the large transport airlines were controlled by oil companies which were not interested in (supplying) two different kinds of aircraft fuel, and in savings of fuel." The May issue of _Aero Digest_ had a full-page illustrated advertisement titled "Announcing National Distribution for Texaco Aerodiesel Fuel." Although distribution was limited, the American oil industry did not prevent the airplane diesel from becoming a success in the civil market. However, it is significant that the advertisement was placed by Frank Hawks of the Texas Company largely as a gesture of friendship to Woolson.[43] The situation in the military market was different, however, as testified by this quotation from the same letter. "The military administration, having paid all of the expenses for the testing period to that date (1931), came after the tests to the conclusion that the advantages of the diesel as compared to its disadvantages did not justify the great risk to procure and distribute two different kinds of fuel in case of war." Two accidents, which received wide publicity and no doubt did considerable harm to the entire project, occurred to Packard diesel-powered airplanes. The following quotation is from the _Herald Tribune_ for April 23, 1930: "Attica, New York--Losing their bearings in a blinding snowstorm and mistaking the side of a snow-covered hill for a suitable landing place, three men, one of them Capt. Lionel M. Woolson, aeronautical engineer for the Packard Motor Company and adapter of the diesel engine to airplanes, were killed here today." [Illustration: Figure 37.--Interior of Bellanca, showing Parker D. Cramer, pilot (left), and Oliver L. Paquette, radio operator, just before taking off from Detroit, Michigan, on July 28, 1931. (Smithsonian photo A202.)] The second of these accidents is described in the September 1931 issue of _U.S. Air Services_: Columbus wanted to sail west beyond the limits set by the learned navigators of his time, and in much the same consuming fashion Parker D. Cramer wanted to show his generation and posterity that a subarctic air route to Europe via Canada, Greenland, Iceland, Norway, and Denmark was feasible.... On July 27, without any preliminary announcement, Cramer left Detroit in a Diesel-engined Bellanca, and following the course he took with Bert Hassel three years ago, he flew first to Cochrane, on Hudson Bay. His next stop was Great Whales and then Wakeham Bay. From there he flew to Pangnirtum, Baffin Land, and across the Hudson Straits to Holsteinborg, Greenland. He crossed the icecap at a point farther north than the routes that have been discussed heretofore, but almost on the most direct or Great Circle route from Detroit to Copenhagen. He was accompanied by Oliver Paquette, radio operator. They were on their way more than a week before they were discovered. To Iceland, to the Faroe Islands, to the Shetlands. They were taxiing across the little harbor of Lerwick, Shetland Islands, when a messenger from the bank waved a yellow paper. It was a warning of gales on the coast east to Copenhagen. Cramer apparently thought it was an enthusiastic bon voyage, and, after circling the town, flew away. A Swedish radio station reported a faint "Hello, Hello, Hello" in English, but the plane was not seen again. As the result of a personal conversation with his brother, William A. Cramer, in 1964, the author learned that the fuselage and floats of the airplane were found six weeks later. Since there was no indication of a heavy impact (not a single glass dial on the instrument panel was broken), a successful landing must have been made. Several weeks later, a package was found wrapped in a torn oilskin containing instruments, maps, and a personal letter, all substantiating the evidence that the landing was successful. It can only be surmised that there was engine failure, probably due to a clogged oil filter.[44] Once before during the trip a forced landing had been made due to engine malfunctioning, and a successful takeoff was accomplished in spite of a moderately rough sea. This time, however, storm conditions probably made the takeoff impossible. As a final summary of the author's analysis of the Packard diesel engine, it must be emphasized that although the engine burned a much cheaper and safer fuel more efficiently than any of its gasoline rivals, it was too unreliable to compete with them. Even if it had been reliable, it was too small to be useful to the large transport operators, to whom its fuel economy would have appealed. In addition, this mechanism operated on the wrong cycle: 4-stroke, rather than the lighter, more compact, and more efficient blown 2-stroke cycle. Lastly, it was doomed by the advent of high octane gasolines, first used while it was still in the development stage. These new fuels reduced the diesel's advantage resulting from low fuel consumption, and, in addition, gave the gasoline engine a definite advantage from the standpoint of performance. The Packard diesel was a daring design but, for the reasons analyzed in this chapter, it could not meet this competition, and therefore failed to survive. Appendix 1. Agreement between Hermann I. A. Dorner and Packard Motor Car Company THIS AGREEMENT made this 18th day of August 1927, by and between HERMANN DORNER, of Hanover, Germany, hereinafter referred to as "Licensor", and PACKARD MOTOR CAR COMPANY, a Corporation of the State of Michigan, United States of America, of Detroit, Michigan, hereinafter referred to as "Licensee"; WITNESSETH, that WHEREAS, Licensor owns certain Letters Patent of the United States and other countries relating to oil burning engines under which he desires to license the Licensee; WHEREAS, Licensee desires rights under said Letters Patent; NOW, THEREFORE, for the mutual considerations hereinafter set forth, the parties have agreed as follows: 1. Licensor warrants that he is the inventor of an oil burning engine, is the sole owner of United States patent Number 1,628,657, dated May 17, 1927, and United States patent applications, Serial Numbers 46,383 filed July 27, 1925, and 88,409 and 88,411, filed February 15, 1926, relating to such engines and is joint or sole owner of patents or patent rights relating to said engines in England, Germany and Sweden. 2. Licensor agrees to furnish the Licensee at cost price but not exceeding Thirty Dollars ($30.00) cash, as many pump and nozzle units as are needed for use in building one or more experimental engines. 3. Licensor hereby gives and grants unto Licensee an exclusive license for the manufacture, within the United States and its dependencies, and a non-exclusive license for the use and sale, of engines for aircraft, and a non-exclusive license for the manufacture, use, and sale of engines for motor vehicles and motor boats, under said United States patent Number 1,628,657, under all after-acquired patents and under all patents that may result from said patent applications, and from all other patent applications pertaining to his present oil burning engine or reasonable variations thereof, such licenses to extend for the full life and term of all such patents, provided however, that there is specially excepted from this grant--stationary engines, tractor engines, and engines for agricultural purposes. 4. Licensor further hereby permits said Licensee to export to all other countries and sell and use there, without further royalty, all engines made by Licensee in the United States under this license. 5. Licensor acknowledges receipt of One Thousand Dollars ($1,000.00) in payment of a portion of the expenses heretofore incurred by him and as one of the considerations for this agreement. 6. Licensor agrees to devote all time necessary from this date to November 1, 1928 to supervision of the design of an engine and construction thereof at the plant of the Licensee and will in his absence furnish the services of a competent assistant, the expenses of Licensor and assistant to be paid for by Licensee at the rate of One Thousand Dollars ($1,000.00) per month for the first three (3) months, and Five Hundred Dollars ($500.00) per month thereafter until the decision in paragraph eight has been made by Licensee. 7. Licensee agrees to build and test at least one experimental aircraft engine with special Dorner features, and to take all reasonable measures to reach the stage of final test. All Dorner feature engines made by Licensee will be marked "Licensed Under Dorner Patents." 8. Within one year after the completion of tests of the aircraft engine built by Licensee hereunder, or in any event not later than November 1, 1928, Licensee will decide whether it will proceed with the manufacture of engines hereunder, or not. If Licensee decides in the affirmative then it will pay Licensor forthwith the sum of Five Thousand Dollars ($5,000.00) as advance on royalties and as minimum royalty for the first production year. If Licensee decides in the negative for reasons which are under the influence of Licensor, then Licensee will give Licensor notice and sufficient time to try to correct possible imperfections, and the time for final decision will be correspondingly extended. If the reasons for the negative decision are under the influence of Licensee, then Licensee will grant to Licensor an oral conference at Detroit and explain the reasons in detail. In event a negative decision is finally rendered by Licensee this agreement may be terminated at any time thereafter upon sixty (60) days' notice in writing to Licensee and both parties released from all further obligations hereunder. 9. Licensee agrees that if after three (3) years from the date hereof Licensee is not manufacturing and does not contemplate the manufacture of, a certain size and type of aircraft engine which Licensor would like to grant another manufacturer the right to build and which would not reasonably compete with anything manufactured by Licensee, Licensee will release such size and type aircraft engine from the exclusiveness of this license and thereby permit Licensor to grant a license to such other manufacturer to make, use and sell such engine and such engine only. 10. Licensee agrees to pay royalty on all engines manufactured and sold or used under this agreement, based on effective brake horsepower under normal load, as follows: On each of the first Five Thousand (5,000) such engines produced and sold in any one calendar year, the royalty shall be at the rate of Twenty-five Cents ($.25) per horsepower; and on all over Five Thousand (5,000) in such calendar year, at the rate of Ten Cents ($.10) per horsepower; provided that, after a total of Fifty Thousand Dollars ($50,000.00) has been paid in royalties the royalties shall be reduced one-half (1/2). 11. After the beginning of the second year of production, Licensee agrees that if the royalties under the above schedule amount to less than Ten Thousand Dollars ($10,000.00) per year then the royalty shall be Ten Thousand Dollars ($10,000.00) per year payable in quarterly instalments of Two Thousand Five Hundred Dollars ($2,500.00) each, or in other words, the minimum royalty payable shall be Ten Thousand Dollars ($10,000.00) per year. 12. Royalties shall continue only during the life of said patent Number 1,628,657, and when a total of Two Hundred Fifty Thousand Dollars ($250,000.00) has been paid by Licensee to Licensor, all royalties shall cease and the license hereunder shall be free thereafter. 13. Licensor agrees that Licensee shall have the benefit of any more favorable royalty rates that may be hereafter granted to or enjoyed by any other manufacturer of engines other than aircraft engines. 14. Licensee agrees to keep proper books of account showing the number of engines manufactured and sold or used under this agreement and to report quarterly to Licensor. 15. In case of suit against the Licensee for infringement of patents by any of the Dorner features built under this license Licensor agrees to assist in the defense of any such suit and pay the expenses thereof up to an amount equal to Ten Percent (10%) of all royalties paid by Licensee to Licensor hereunder. 16. In event of default of the Licensee in the payment of any of the sums herein provided for, Licensor may terminate this license agreement by serving upon the Licensee Sixty (60) days' notice in writing of its desire and determination so to do and stating the default upon which the notice is based, and at the expiration of such Sixty (60) days this license shall thereupon be terminated, provided however that such termination shall not release the Licensee from obligations already accrued hereunder and not performed, and provided further that if, during said Sixty (60) days' notice period, the default named in said notice shall have been made good then this license to continue as if no default and notice had been made or given. 17. At the expiration of any one year from November 1, 1929, Licensee may terminate this agreement upon Sixty (60) days' notice in writing to Licensor of its desire and determination so to do, provided however, that such termination shall not release the Licensee from obligations already accrued hereunder and not performed. 18. In case of differences of opinion regarding any of the terms of this agreement, the dispute shall be submitted to arbitration. Each party shall select one arbitrator and if they, after five days, fail to agree upon a third, the United States Court for the Detroit District shall be asked to appoint such a third arbitrator, and the decision of a majority of the arbitrators shall be binding upon both parties. In witness whereof, we have hereto set our hands and seals at Detroit, Michigan, on the day and year first above written. Witnesses--(Signatures): Hermann Dorner L. A. Wright Adolf Widmann PACKARD MOTOR CAR COMPANY Alvan Macauley President (Seal) Attest: Milton Tibbetts Assistant Secretary 2. Packard to Begin Building Diesel Plane Engines Soon _Will Start Construction at Once on New Three Story Factory to Handle Work_ [From _Aviation_, March 2, 1929, vol. 26, no. 10] DETROIT, MICH.--Indications that the Diesel type airplane engine, recently developed by Capt. L. M. Woolson, chief aeronautical engineer of the Packard Motor Car Co., will become a commercial reality and possibly a revolutionary factor in airplane engine design, is seen here in the announcement of the concern that it will begin construction immediately of a $650,000 plant to produce the engines in large quantity for the commercial market. The new plant, according to the announcement by Hugh J. Ferry, treasurer of the Packard firm, will be completed and in operation within five weeks. Between 600 and 700 men will be employed and, according to expectations, production will be carried on at the rate of about 500 Diesel engines per month by July. The Packard Diesel was announced first in October, following experiments covering several years. The original engine was placed in a Stinson-Detroiter, which was flown successfully by Captain Woolson and Walter Lees, Packard pilot. Since that time Captain Woolson has built four of the engines, all of 200 hp. capacity, developing 1 hp. for every 2 lb. of weight. The Diesel, installed on the Stinson-Detroiter, it was said, now has had 200 hr. flying time, and gives not the slightest indication that it will need an overhauling for some time. The other three engines have been tested on the block in the company's research plant. It is claimed by the builders that the Packard Diesel will produce a saving of about 20 per cent. in fuel consumption as compared with engines using gasoline. It is claimed further that the Diesel will prove far more reliable in construction than any airplane engine yet developed. Evidence of this, it was pointed out, is seen in the performance of the initial Diesel. DETAILS NOT ANNOUNCED Although neither Mr. Ferry, nor Captain Woolson, would disclose any technical details as to the engine's construction in making it applicable to airplane use, the secret of its success was reported to be an especially designed pumping device creating high compression necessary for Diesel firing. Since announcement of the engine, the Packard factory has been literally a Mecca for engineers from many parts of the world wishing to see the engine. The Crown Prince of Spain, in Detroit last fall, was given a flight in the Diesel powered Stinson. None of the construction secrets, however, have been divulged, it was said. The Packard announcement set at rest rumors that the company planned construction of a plant costing several million dollars, as well as reports that the company was going into the production of airplanes. "Our efforts," Mr. Ferry said, "will be confined to the engine, or power plant end of the aircraft industry. We will continue to build the water-cooled type we have been producing for years." The new Diesel plant will be primarily an assembly plant, although some machine work will be done there. The bulk of the machine work, however, will be done in the present Packard machine shops. Although no approximation of selling price on the new Diesel was divulged, it was intimated that the engine will retail at a price competitive with or slightly under the price of present gasoline consuming air-cooled engines of that horsepower range. Captain Woolson will have complete charge of the Diesel plant, it was announced. 3. Effect of Oxygen Boosting on Power and Weight [From P. H. SCHWEITZER and E. R. KLINGE, "Oxygen-Boosting of Diesel Engines for Take-Off," _The Pennsylvania State College Bulletin_ (April 1, 1941), vol. 35, no. 14, p. 25.] _Practical Conclusions_ Airplanes require about one third more power during the take-off than in flight. In diesel-engined airplanes the size of the engine could be reduced by 25 percent by feeding oxygen into the intake air during the takeoff. Applying the results of the experiments to a transport plane, Fig. 31 shows the possible weight saving with various oxygen boosts. The curves are based on 6000 cruising horsepower and an estimated engine weight of 2 lb per hp. For the take-off 8000 hp are necessary. To supply the additional 2000 hp, 200 lb of oxygen are fed into the intake air during the take-off. The volume of 200 lb of liquid oxygen is approximately 20 gal. Standard liquid air containers of 55 litre capacity weigh 75 lb. Therefore the weight of the oxygen and container is 350 lb while the possible saving in engine weight is 4000 lb. The weight per take-off horsepower is thereby reduced from 2 to 1.54 lb. The calculation is shown in Table 1. [Illustration: Figure 38.--Effect of Oxygen Boost on Power and Weight. (Cruising horsepower 6000, takeoff horsepower 8000.)] Oxygen addition may be used for starting diesel engines. The raising of the oxygen concentration from the normal 21 per cent to 45 per cent was found to be equivalent to a raise of approximately 10 cetane numbers as far as starting is concerned. Five per cent increase in oxygen concentration eliminated exhaust smoke completely. TABLE 1 Normal horsepower 6000 Take-off horsepower 8000 Normal fuel consumption 0.4 lb per hp-hr, or 53.5 lb per min Normal air consumption 900 lb per min Normal oxygen consumption, 21 per cent oxygen 189 lb per min concentration Boosted oxygen consumption, 32 per cent oxygen 289 lb per min concentration Oxygen to be supplied 100 lb per min Weight of 8000-hp engine 16,000 lb Weight of boosted 6000-hp engine 12,000 lb Weight of oxygen for 2-min boost 200 lb Weight of container for 29 lb of liquid oxygen 150 lb Net weight saving by oxygen boost 3650 lb Weight per horsepower, nonboosted engine 2 lb Weight per horsepower, boosted engine 1.54 lb Footnotes: [1] Appendix, p. 43. [2] Letter, Hermann I. A. Dorner to National Air Museum, March 3, 1962. [3] See p. 20 ff. [4] Appendix, p. 46. [5] _Aeronautics_ (October 1929), vol. 5, no. 4, p. 32. [6] _The Packard Diesel Aircraft Engine--A New Chapter in Transportation Progress_ (Detroit: Packard Motor Car Co., 1930), p. 5. [7] A memorial to Woolson who was killed in the crash of a Packard diesel-powered Verville "Air Sedan" on April 23, 1930. [8] _Packard Inner Circle_ (April 18, 1932), vol. 17, no. 6, p. 1. [9] _Aero Digest_ (February 1932), vol. 20, no. 2, p. 54. [10] Letter, Richard Totten to National Air Museum, January 28, 1964. [11] _Instruction Book for the Packard-Diesel Aircraft Engine_ (Detroit: Packard Motor Car Company, 1931), p. 3. [12] _S.A.E. Journal_ (April 1930), vol. 24, no. 4, pp. 431 and 432. [13] Letter, Richard Totten to National Air Museum, January 28, 1964. [14] Letter, Hermann I. A. Dorner to National Air Museum, December 16, 1961. [15] _The National Aeronautic Magazine_ (April 1932), vol. 10, no. 4. p. 18. [16] _Aviation_ (May 1931), vol. 30, no. 5, p. 281. [17] _The Packard Diesel Aircraft Engine_, p. 5. [18] _Instruction Book for the Packard-Diesel Aircraft Engine_, p. 3. [19] "Test of Packard-Diesel radial air-cooled engine," Navy Department, Bureau of Aeronautics, Report AEL-335, July 13, 1931, Bu. Aer. Proj. 2265. [20] _Aviation_ (May 1931), vol. 30, no. 5, p. 281. [21] Letter, Clarence H. Wiegman to National Air Museum, November 1, 1961. [22] Letter, Dorner to National Air Museum, January 15, 1962. [23] Letter, Hugo T. Byttebier to National Air Museum, October 20, 1961. [24] Letter, Clarence D. Chamberlin to National Air Museum, February 8, 1964. [25] RUTH NICHOLS, _Wings For Life_ (Philadelphia and New York: J. B. Lippincott Co., 1957), p. 205. [26] Letter, Richard Totten to National Air Museum, January 28, 1964. [27] Letter, Richard Totten to National Air Museum, January 28, 1961. [28] _Aero Digest_ (February 1931), vol. 18, no. 2, p. 58. [29] "50-Hour Test of Packard Diesel Aircraft Engine," Packard Motor Car Company, Detroit, Michigan, serial no. 426, test no. 234-73, February 19, 1930. [30] Blower in this sense refers to a low-pressure air pump (supercharger) designed to increase cylinder scavenging efficiency by blowing out exhaust gasses. In doing this it also increases somewhat the amount of fresh air introduced into the cylinders. Woolson invented a 2-stroke cycle blown engine; the patent was issued in 1932 (patent 1853714) with rights assigned to the Packard Motor Car Company. (Woolson himself died in 1930.) [31] A 2-stroke cycle engine completes 360° of crankshaft rotation in what it takes a 4-stroke cycle engine 720° to accomplish. A 3-cylinder two-stroke cycle engine therefore has the same capacity to do work as a 6-cylinder four-stroke cycle engine. For this reason the former type of engine is both more compact and lighter than the latter type. The above advantages, plus the increased efficiency of the blown 2-cycle diesel, are discussed in _Flight--The Aeronautical Engineer Supplement_ (December 26, 1940), vol. 19, no. 11, pp. 545 and 552. [32] Packard advertisement--_Aero Digest_ (June 1930), vol. 16, no. 6, p. 23. [33] _Aviation_ (March 15, 1930), vol. 28, no. 11, p. 531. [34] _The National Aeronautic Magazine_ (April 1932), vol. 10, no. 4., p. 18. [35] Appendix, p. 47. [36] See Woolson's patent 1794047, issued in 1931 and assigned to the Packard Motor Car Company. "An object of my invention is to automatically regulate the compression ratio in an engine inversely to the speed...." See also his patent 1891321, issued in 1932 and assigned to the Packard Motor Car Company. It describes a similar but nonautomatic system. Woolson therefore fully realized the disadvantages of the high cylinder pressures his engine developed at high rpm's. [37] Letter, Clarence H. Wiegman to National Air Museum, November 1, 1961. [38] Ibid. [39] Major George E. A. Hallet, U.S. Air Service, former director of engineering division, McCook Field, Dayton, Ohio. [40] "Test of Packard-Diesel radial air-cooled engine," Navy Department, Bureau of Aeronautics, Report AEL-335, July 13, 1931, BuAer Proj. 2265. [41] _Aviation Week and Space Technology_ (February 19, 1962), vol. 76, no. 8, p. 101. [42] _Aeronautics_ (October 1929), vol. 5, no. 4, p. 31. [43] Letter, Richard Totten to National Air Museum, January 28, 1964. [44] According to Frederic E. Hatch of the National Air Museum, it is possible that the engine failed because the fuel injectors became clogged. He notes that the airplane refueled at several fishing ports, and therefore must have used diesel oil set aside for fishing boats. This oil was generally quite dirty. As a result it was routine for the fishermen to have to clean engine oil filters frequently enroute. The oil filters of the Packard diesel could not be cleaned in flight. Transcriber's Notes: Passages in italics are indicated by _underscore_. Passages in bold are indicated by =bold=. The following misprints have been corrected: "crackcase" corrected to "crankcase" (page 16) "is is" corrected to "it is" (page 36) Other than the corrections listed above, printer's inconsistencies in spelling, punctuation, and hyphenation usage have been retained. 
38109	----	LECTURE ON ARTIFICIAL FLIGHT GIVEN BY REQUEST AT THE ACADEMY OF NATURAL SCIENCES AT San Francisco, California, August 7th, 1876, BY WM. G. KRUEGER WITH REFERENCE TO A MODEL OF HIS OWN INVENTION. INDEX. No. Page. 1 Introduction 1 2 History and Fable 2 3 Discovery of the Balloon 7 4 Noted Air Voyages 8 5 Absence of Danger 11 6 Charm of Ærial Travel 12 7 Ærial Voyages Health Promoting 15 8 Parachutes 16 9 The Kite 17 10 Balloons Impracticable 18 11 Reasons why the Problem has remained Unsolved 21 12 Fundamental Principles in Flight 23 13 Weight 24 14 Surface 26 15 Power 28 16 Flying Creatures, their Proportions, Movements 31 17 Mechanical Practicability of Flight 34 18 Flying Machines of the Present, their defects 37 19 The Practical Air Ship of the near Future 43 20 What Ærostation will Accomplish 48 21 Closing Remarks 50 * * * * * ERRATA. Page 4, line 4, read "one from Koenigsberg," for "Koenigsberg." Page 4, line 18, read "afterward," for "ago." SAILING IN THE AIR. I.--INTRODUCTION. _Gentlemen of the Academy_: The problem of artificial flight is of such great importance to civilization; so interesting and fascinating, not only to the student, but to every one; and it allows us to indulge in such a wide field for speculation as to the great changes which will be wrought by the practical solution of it in the social, political and commercial world, that I must beg of you to consider only my good intentions in appearing before you, and pardon my shortcomings as a lecturer. It is my first attempt, and is simply undertaken to bring the subject more understandingly before the public, that they may assist, morally, and pecuniarily, the several inventors who are wrestling with it more or less successfully--some rather less. If only one inventor in a hundred should meet with flattering results, the attention bestowed upon all will be repaid a thousand fold by that one's success. The idea of sailing through the air in a flying machine is not new, nor such an absurd one as is generally supposed; and it is indeed important to investigate and lay it before the public more directly than has been done heretofore through the medium of great, musty and long-winded volumes. If found to seem practicable and feasible, it is for you, gentlemen, to see that the future great State of California shall also be ahead in this--one of the greatest and most important inventions of the age--as she is, and has been in many other things before. The subject has really been taken hold of in a thorough and scientific manner only the last few years; but with such earnestness and scientific knowledge and intelligence, not only by the foremost and principal society for the advancement of the art--the Aeronautic Society of Great Britain--to whom, really, the most credit must fall--but in every civilized country; and so much has been done already to prove, not only the possibility but the absolute certainty of an early practical solution of the problem, that soon we will see the air traversed in all directions, by aspiring man. Many seeming impossibilities of the present, need only time and effort to become realities in the near future. II.--HISTORY AND FABLE. In turning our thoughts to History, reaching back even into the mazy and wonderful ages of fable, we find that from time immemorial the great science of ærostation has occupied the minds of philosophers and inventors. There can be little doubt that it was known and made use of in olden times in isolated cases, but was again lost, like many other important inventions. We are furnished with many interesting proofs of this. Old Chinese, Arabian and Hindu fables give some beautiful descriptions of ærial chariots, in which wizards, princes and fairies sped over the fertile and populous plains of their native country, disbursing good or evil, according to their disposition, to the poor devils crawling in the dust beneath them. The Jews had their cherubim. The Assyrians have left us their winged bulls; the Greeks, their Sphinxes; while the Roman writers describe how that mythical personage, Daedalus, a famous Athenian artificer, and builder of the Cretan labyrinth, constructed wings with which he flew across the Ægian Sea, to escape the resentment of Minos. But his son, Icarus, undoubtedly of his strength giving out, fell into the water and was drowned. Their nation has bequeathed to us various bas-reliefs, illustrative of what appear well-proportioned wings. Archytos, the great geometrician, made a wooden dove that flew like a natural one, and the famous German astronomer, John Mueller, who died suddenly in Rome, at the age of forty, in 1476, and whose memory was celebrated last month in Germany, constructed an artificial eagle, which flew out to greet the Emperor, Charles V, when he visited Nuremberg. This Mueller was more widely known by the assumed name of "Regiomontanus,"--the "Kingshiller"--that is, "one from Koenigsberg," a small village in the heart of Germany; the custom of the times being for learned men to adopt the latin name of their birthplace. He invented the almanac, and prepared the first astronomical tables, by the aid of which mariners, who, up to that late day could only make coasting voyages, were enabled to trust themselves to the open sea, with some degree of assurance; and Columbus was among the earliest to use these tables, twenty years afterwards, on his first discovery voyage to America. * * * * * Another German, a young watchmaker's apprentice, constructed a flying machine, with which he, when showing the same to his ignorant townspeople, flew away to escape mobbing. His bones and pieces of the machine were found some years afterward in a wild and isolated part of the Black Forest. Towards the end of the fifteenth century Giovanni Battista Dantes, of Perugia, flew several times over the Thrasimenian Sea; he certainly must have been at a considerable elevation, for he fell on a church steeple and broke a leg. Another account, particularly noticed in history, is that of a man who flew high in the air in the City of Rome, under the reign of Nero, but lost his life in the descent. In "Astra Castra," we read that soon after Bacon's time, projects were instituted to train up children in the exercise of flying with artificial wings, and considerable progress was made; by the combined effort of running and flying they were enabled to skim over the surface, as it were, with incredible speed. This same Roger Bacon, an eminent philosopher of the thirteenth century, and possessed of the very highest genius and ability, whose ideas and knowledge, like Franklin's, were many hundred years ahead of his age, descants, in one of his works, in glowing language, on the practicability of constructing engines that could navigate the air. He accomplished wonderful things in his day, and was accused of holding communion with the devil, who was quite an important personage in those times. His writings were interdicted, and himself locked up to prevent closer acquaintanceship of his readers with the aforesaid friend. About the Confessor's time, a monk, Elmirus, in Spain, flew often, by means of a pair of wings, many miles from high elevations. Cuperus, in his treatise on "The Excellency of Man," contends that it is practicable for human beings to attain the faculty of flying. He asserts that Leonardo da Vinci, the great painter of the "Lord's Supper," and other highly prized works of art, practiced it successfully. The reasoning of the great John Wilkins, Lord Bishop of Chester, who died in 1672, embodies the sentiments and principles of all these on the subject even stronger. In his work on "Mechanical Motion," he treats expressly on artificial flight, and conceives, in the sixth chapter, the framing of such "volitant automata" very easy; and says that the time will come when men will call for their wings when about to make a journey, as they do now for their boots and spurs. Lastly, in the "Journal de Savans," of the 12th of September, 1678, an account is given of one Besnier, a locksmith of Sable, France, who succeeded in flying. But as his machine was extremely primitive--the wings consisting only of four rectangular surfaces, one at the end of each of two poles, which passed over the shoulder of the operator, and were worked alternately up and down--the inventor could only avail himself of their aid in progressively raising himself from one hight to another, until an elevated position was reached, when he could glide through the air a long distance. Many more cases could be cited. Some ended disastrously; others, because of the apathy, distrust, ignorance, and superstition of the people, were lost sight of again; while some, perhaps the most practical ones and of which we find many indications in old writings, were never made known for selfish reasons. Such has been the fate of this--one of the most interesting problems--almost up to the present time. We were, perhaps, not prepared sufficiently, to receive the great boon. We had to have the printing press, steam, and electricity first, before we could attempt this next great step towards a higher civilization. III.--DISCOVERY OF THE BALLOON. Although it is well understood now by most scientific men, that the principles upon which ballooning rests, will scarcely form any part in the solution of the problem of ærial navigation; yet, when, in 1782, the brothers, Mongolfier, in France, made the first successful experiments with small paper balloons, filled with heated air, it was thought that the key to that wonderful art had been found; many applied themselves to its improvement; and the next year already saw gas balloons on a much larger scale. The first passengers, who had the honor of being sent up into the realms of space, were a sheep, a cock and a duck; and as their safe descent proved highly satisfactory, the well-known French savan, Pilatre de Rozier, tried the same experiment shortly afterwards with great success, reaching a hight of nearly two miles. The glowing description of his experience raised the excitement of all classes to fever heat. Numerous day and night ascensions were made by diplomats, distinguished naturalists, professors of note, scientific women and gymnastic aspirants, and their journeys soon became more daring and extended to wider fields. IV.--NOTED AIR VOYAGES. Blanchard, the supposed inventor of the parachute, with the American, Dr. Jeffries, were the first to cross the channel from England to France. M. Charles, the inventor of the gas balloon, and one of the earliest and most enthusiastic advocates of ærostation, made extensive voyages. Madame Thible, of Lyons, was the first of her sex who trusted herself to the elastic element. Crosbie, who passed over the sea from Ireland to England, came near losing his life; for, the balloon, being struck with great force by an adverse current of air, and most of the gas escaping, tore over the raging waters at a fearful speed, until the courageous man was rescued, near the English coast, by a ship happening in his way. But the view which he had enjoyed, seeing both countries at once, was sublime beyond description, and compensated him for all the danger. He had been at such a hight that, although the July sun melted everything below, his ink was a lump of ice, and the quicksilver in the instruments had sunk almost out of sight. The battle of Fleurus, in 1794, was won by the French over the Austrians principally through the aid of balloon reconnoitering; and similar service was occasionally performed by the balloon in our own war. The favorably known Italian, Count Zambeccari, who added many improvements to this art, and created great interest in the principal countries of Europe, made an ascension, in 1803, with two friends, at Bologna. The three alighted in the Adriatic sea and were picked up by fishermen, while the balloon, free from weight, rose again and was carried by the wind to the Turkish fort Vihacz, where the commander, believing it a present "sent from heaven," had it cut up in small pieces and divided amongst his friends as amulets. But quite a "reverse opinion" was generally entertained by most of the ignorant Christian country people, when the huge monster happened to fall amongst them for the first time; and their comparison of it to the "evil one" is excusable when we consider the peculiar smell of the escaping gas, after their attack upon it with pitchforks and similar agricultural implements. Among other remarkable ascensions is that of Guy Lussac, who reached the prodigious hight of nearly four and a half miles. This was exceeded, though, by another scientific æronaut, James Glaisher, in 1862, who, with a companion, mounted the great altitude of seven miles--over 36,000 feet; but as he was insensible for some minutes after reaching the elevation of 29,000 feet, the highest ever attained by human beings, their calculations could only be approximated. The mercury in the hygrometer--a delicate instrument for measuring the moisture in the atmosphere--had fallen below the scale, while they were rising more than 1000 feet per minute. There are instances of balloons that have shot upwards at the rate of fifty feet per second, or much over half a mile per minute; but, generally, even twenty feet per second is a rare occurrence. And here might be mentioned that, since the late serious loss of several French scientists by asphyxia, or cold on their unfortunate ascension, the problem of maintaining life in the highest regions of the atmosphere has been solved in France. With a certain apparatus, man could manage to live comfortably nearly ten miles above the level of the sea, while, ordinarily, two miles is the most. As to horizontal speed, perhaps the fastest time on record was made by Garnerin and Snowdon, from London to Colchester, some eighty miles, in one hour, or about 110 feet per second, almost swifter than an eagle flies; and another balloon went from Paris across the Alps, to the vicinity of Rome, in twenty-two hours, making over fifty miles per hour, considering its zig-zag travel. The reason for such great speed is, that the different air currents travel far faster in the upper regions than below, where the velocity of the wind is seldom over twenty miles per hour; and yet, were it not for the continually changing scenery, the æronaut would imagine himself stationary. The shortest trip, perhaps, in the annals of this art, both as to hight and distance, was made, a few years ago, by a gymnast, at Woodward's Gardens, that most beautiful pleasure resort in this city. The little disobliging monster went lazily, and with great difficulty, over the fence and capsized promptly on the other side, leaving the trapeze-man hanging, by the seat of his unmentionables, on the top of it in an uncomfortable position, but no bones were broken. V.--ABSENCE OF DANGER. It is erroneous to suppose that ærial voyages are fraught with even ordinary danger; on the contrary, travel by sea and land is far more so; for, although thousands of assensions have been made, but very few persons have met with accidents, in fact, a less number by far comparatively, than by any other profession or mode of locomotion; and, whenever such has happened, gross carelessness or ignorance was often the cause. During the late Franco-German war, over sixty balloons, many but indifferently constructed, left Paris, during the siege, with some one hundred and eighty persons and nearly three millions of letters. All reached a point of safety. Professor Wise, the most noted American æronaut, has made, during the last forty years, nearly five hundred voyages, and one in particular, in 1859, of nearly 1200 miles--perhaps the longest on record--with three companions, from St. Louis, Mo., to New York State. This trip was made partly in the midst of a tornado, while above Lake Erie, during which time some twenty sailing crafts succumbed to the effects of the storm, yet the intrepid æronauts alighted in safety. M. Green, who was the first to use coal gas, instead of pure hydrogen, and has also made hundreds of successful ascensions, was carried from London to Weilburg, in the central part of Germany, about seven hundred miles in eight hours, without the slightest mishap. Lastly, Arban, crossed the Alps from Marseilles to Turin, four hundred miles, in stormy weather during the night. Mont Blanc to the left, on a level with the top of which he was, resembled an immense block of crystal--sparkling with a thousand fires; while the moon occasionally seemed to have borrowed the light of the sun. VI.--CHARM OF ÆRIAL TRAVEL. Nothing can equal the beauty of an ærial voyage, that most wonderful, easy and luxurious mode of locomotion, with its entire absence of dizziness--this sensation being lost with the separation from earth, as soon as the last cord, which unites us with the world below, is cut. In rising from the ground, the feelings are absorbed in the novelty and magnificence of the spectacle presented, while the ears are saluted with the buzz of distant sound until the clouds are reached, when all is still as death. The scene is sublime. Around and beneath, the clouds roll in magnificent grandeur. They form pyramids, castles, reefs, icebergs, ships and towers, and again dissolve into chaos. The half obscured sun shedding his mellow light upon the picture, gives it a rich and dazzling lustre. Reverence for the work of nature, the solemn stillness, an admiration indescribable, all combined, seem to make a sound of praise. The earth, which is never lost sight of at any hight, except clouds interfere or night sets in, seems to be concave, like the inside of a flattish hollow globe, instead of the outside, as would naturally be supposed. The reason for this optical delusion is, that the horizon appears on a level with the æronaut, while the distance downwards remains unaltered, making the surface below appear like a valley. The earth presents the panoramic view of an immense map, such as the enchanted Alladdin must have enjoyed. The coloring, designating the various products of the soil, is lively and exquisite. Variegated grass-plats, the golden tinge of waving grain fields, the more sombre foliage of the trees, the glossy surface of the water dazzling in the sunbeams, with occasional white specks for sailing craft; the innumerable villages, with tastefully decorated and tinny, toy-like houses, the numerous roads tortuously spreading over the surface and looking like chalk lines on a gaudy carpet, fairy-like carriages seemingly drawn by mice and guided by liliputian little things. Such is the beauty of this glorious earth. Yet, when mountains appear like ant hills, and Niagara a neat little cascade in a pleasure garden--instead of the raging grandeur, only a frothy bubble--man must be forcibly reminded that he is but the minutest animalcule, and not of so much importance as he presumes himself to be. No less impressive is the scene at night. The sublime exhibition in the vast solitude and darkness of night creates the most stupendous effect upon the lonely æronaut. The earth's surface, as far as the eye can reach, absolutely teems with the scattered fires of a watchful population, and exhibits a starry spectacle below, that rivals in brilliancy the lustre of the firmament above. A city looming up in the distant horizon gradually appears to blaze like a vast conflagration. On drawing near, every street is marked out by its particular line of fires; the forms and positions of the theatres, squares and markets are indicated by the presence of larger and more irregular accumulations of light, and the faint murmurs of a busy population still actively engaged in the pursuits of pleasure or the avocation of gain; all together combined form a picture, which, for beauty and effect, can not be conceived. Again, higher up, or when clouds intervene, the sky, at all times darker when viewed from an elevation, seems almost black with the intensity of night; while, by contrast, the stars redoubled in their lustre, shine like sparks of the whitest silver, scattered upon the jetty dome around. Nothing can exceed this density of night. Not a single object of terrestrial nature can anywhere be distinguished, and an unfathomable abyss of "darkness visible" encompasses one on every side. It seems like cleaving the way through an interminable mass of black marble, and a light lowered from these dizzy hights appears to absolutely melt its way down into the frozen bosom of the surrounding inkiness. The cold is here intense. VII.--ÆRIAL VOYAGES HEALTH PROMOTING. But while the charm of floating in the air is so fascinating these delightful ascensions will be even more beneficial in sanitary respects. Atmospheric pressure, exerting nearly 30,000 pounds upon a human being of full growth, has much to do with the mechanical functions of life. At a moderate elevation, one-tenth of this weight can be relieved, and at greater hights, even one-third, as balloon experiments have sufficiently proven. This pressure, then, diminishing upon the muscular system, allows it to expand. The lungs at once become more voluminous and breathing purer air; the freedom with which all the circulating fluids of the system are allowed to act in the rare atmosphere, intensely quicken the animal and mental faculties; the novelty of the voyage, and the most sublime grandeur opening to the eye and mind of the invalid; all assist to promote health, impart new life, inspire ideas and invigorate soul and body. VIII.--PARACHUTES. This simple contrivance often forms an adjunct to balloons. Its appearance is generally that of a huge family umbrella of revolutionary times. It is likewise concave underneath, because such form, above all others, condenses a column of atmosphere more rapidly and retards its velocity in the descent immensely. The ribs are generally of whale-bone or bamboo covered with strong domestic muslin, and a light wicker basket is fastened some twelve feet underneath for the æronaut, who may cut himself loose from the balloon with perfect safety at any hight, and descend slowly to the ground, if the parachute is strongly made and perhaps fourteen feet across when open. By giving it a slight inclination, it can be made to descend, sliding-like, a long distance from the vertical point; and some of the flying machines we read of have likely been only a modified form of the parachute. The nautilus on the ocean moves on the principle of it, the pollen of plants is carried from one place to another by this mode; so the flying squirrel moves in parabolic curves from tree to tree and even crosses rivers when the nut crop fails; as also the flying tree-frog slants down long distances from high trees. This animal has a considerable expansion of skin, connecting the toes only, and which looks as if on its four legs were fastened those short, broad and light snow-shoes, known as Webfeet, used in our northern Territories in winter. It is, therefore, called a "webfoot" frog, but from which must not be inferred that it is "an Oregonian," for it is encountered so far only in Borneo. IX.--THE KITE. Every one is undoubtedly acquainted with the exceedingly simple mechanism--invented when boys commenced to exist--for the enjoyment of one of the most pleasant pastimes--kite flying. It is indulged in mostly during the fall, and, perhaps, a trifle more so in the rural districts than in the cities, because of the greater freedom of room which stubble fields and meadows allow. But attention has also been given to the employment of this kind of ærostation as a means of support and conveyance; and kites have been made as much as thirty feet high, looking more like buoyant sails than boyish playthings, and exerting an immense power of waftage. Loaded wagons have been drawn over turnpikes; persons have frequently been carried up in the air by huge kites; and, in some parts of Europe, experiments have been made to signal and save shipwrecked people on dangerous coasts, proving sufficiently that the kite can be made, even in its present primitive state, to be quite useful. In this connection it may "not be amiss" to state that the first person known to have ascended--some eighty years ago, as the "History of Kite Carriage" informs us, "was a Miss"--a young lady of some one hundred and twenty-six pounds, avoirdupois. She was seated in a chair underneath the gigantic structure which weighed nearly thirty pounds, had a surface of about sixty square feet, and rose most majestically to a hight of six hundred feet--an incontrovertible instance of the superior courage of the gentler sex over man. The kite is maintained in the air by two opposing forces: the impelling power of the wind--lifting it by striking against it at an angle, and the restraining powers of the string--motive-force and gravitation combined; so that in the kite, above all, we possess in a crude form, the three principles requisite for artificial flight: the plain, weight and propelling force. By improving upon the kite, therefore, we will arrive at the practical solution of the problem of artificial flight. X.--BALLOONS IMPRACTICABLE. It is not creditable to the present age that the problem of ærial navigation has not been solved. But one of the causes has undoubtedly been the discovery of the balloon, which has retarded this science for nearly a century by misleading men's minds, and causing them to look for a solution of the problem by the aid of a machine lighter than air, and which has no analogue in nature. Weight is one of three essential factors in flight, for a light body cannot be propelled through a heavier one. Hence all attempts at driving and guiding the balloons have signally failed. This arises from the vast extent of surface which it necessarily presents, rendering it a fair conquest to every breeze that blows, and because the power which animates it is a mere lifting power, which acts in a vertical line. The balloon, consequently, rises through the air in opposition to the law of gravity, by which all flying creatures are governed, very much as a dead bird falls downward in accordance with it. Having no hold upon the air, this cannot be employed as a fulcrum for regulating its movements, and hence the cardinal difficulty of ballooning as an art of locomotion and its uncertainty, because the air-currents cannot be regulated. A balloon starting from San Francisco might be intended for New York, but, against the desire of the passengers, alight in China or the Canibal Islands, which would be rather disagreeable. It is simply astonishing to hear of people trying, year after year, to propel elongated or cigar-shaped balloons with a car underneath, and a screw-propeller, of course--an experiment which was tried, unsuccessfully, forty years ago. But this is generally the first conceived project of an aspirant for fame who commences to think on the subject, and soon fancies himself the happy possessor of the secret; yet what a very small amount of science is necessary to show its fallacy. In fact, all kinds of propositions for the propulsion of balloons have been advanced and experimented upon, but scarcely any improvements have been made since the first five years after its invention; proving, perhaps, more conclusively than anything else, that the practical propulsion of balloons is an impossibility. The most remarkable idea in this respect, was undoubtedly that of Teissol. He flattered himself to be able to train geese or other birds to pull a balloon by being hitched to it, while the conductor, in a car underneath, was to direct their movements by the aid of a long pole. Although the training of birds is not so ridiculous as it may seem, yet he found that geese, if not too tough, answer the purpose of a good roast much better. And another genius, still more unique, long before balloons were invented, conceived the idea that air, like water, must have a defined limit, and that it was possible to sail on its surface like ships on the ocean. He did not state how to get up there, but lost no time in inducing the King of Portugal to forbid everyone, under penalty of death, to use said invention. So far, no one has come in conflict with that law. Yet, although the balloon is impracticable as a means of transportation, it should by no means be discarded, for it can be made very useful for scientific and other observations, to give pleasure to thousands of people by fanciful ascensions, and not the least, to serve, as stated before, sanitary purposes, when captive and well secured. But instead of lowering and elevating it continually, as is being done at present, and which occasions danger and great loss of time and money, a contrivance should be made by which persons could safely, and without interruption, be carried up and down underneath parachutes. XI.--REASONS WHY THE PROBLEM HAS REMAINED UNSOLVED. The slow progress made, and the unsatisfactory state of the question, notwithstanding the large and universal share of attention bestowed upon the subject from earliest times, must be attributed to a variety of causes, the most prominent of which are-- "The great difficulty of the problem. "The incapacity on the one hand, or theoretical tendencies on the other, of those who have devoted themselves to its elucidation. "The lack of means of inventors generally, and the difficulty of obtaining the same to experiment and carry out their ideas even after the completion of their invention. Hence so many failures amongst this class, while men of genius in the literary or most other fields require but little pecuniary outlay to succeed. "The stolid indifference of an unthinking community, which so often proves the deathblow to the mind of the philosophical inquirer, and whose aim is condemned and pronounced as 'visionary,' absurd and incapable of realization, instead of receiving that support and encouragement which is so necessary to success." Flight has therefore been unusually unfortunate in its votaries. It has been cultivated on the one hand by profound thinkers, especially mathematicians, who have worked out innumerable theorems, but have never submitted them to test of experiment; and on the other by either uneducated charlatans who, despising the abstractions of science entirely, have made the most wild and ridiculous attempts at a practical solution of the problem; or inventors, who, desirous to triumph over some of the acknowledged difficulties of propulsion and navigation, but for want of organization or pecuniary support, or being unacquainted with preceding failures in the same direction, or ignorant of some one condition demanded by the peculiar nature of the experiment, but which is absolutely necessary to success, have also failed, thus causing still greater doubt in the public mind, and, consequently, less support to inventors in the same direction afterwards. A common error prevails, that models are essential to help the inventor. The province of the model is to explain the invention to others after it has been made, and not to assist the inventor. Except in very restricted limits they have been found to be almost useless, and most of our valuable discoveries have been made and carried out without their aid. Watt's first condensing engine had a cylinder of eighteen inches diameter, or about the average size now in use. It is so with agricultural and other practical inventions and applies particularly to flying machines. Models often signally prove failures on a small scale, yet would be successful on a larger. The problem is not an unphilosophical phantom, but a mathematically demonstrated truth, which needs only actual realization to revolutionize the world for the better. That the air is navigable can no longer be denied. XII.--FUNDAMENTAL PRINCIPLES OF FLIGHT. In contemplating the boundless atmosphere, we perceive it to be tenanted by a multitude of creatures of varied form and size, who move and direct themselves with marvellous ease and skill. These beings, so different in their nature, form and construction--from the proud eagle to the "blood-thirsty" mosquito--resemble one another in the possession of three important fundamental principles which constitute the power of flight. These are--weight or gravity, surface or resistance of the atmosphere against it, and force or power of projection. The medium in which the phenomenon of flight is produced--the air--is an invisible, impalpable, comparatively imponderable fluid, and its density is nearly 800 times less than that of water. Hence a movement through it can be made far more rapidly than through its sister medium. Nevertheless, if agitated, it is capable of exerting great pressure, as the tempestuous storms, overturning fences, unroofing houses, uprooting trees, and carrying even large animals into the air, teach us. Hereon then, that is, the proper manipulation principally in creating artificial currents of air, hinges the secret of flight, because this phenomenon is reproduced in a manner identical, if a surface is moved against it, as we see in the wings of flying creatures. XIII.--WEIGHT. Weight is absolutely indispensible in flight, it adds momentum and assists the propelling power--with greater force comparatively in heavier bodies. A wooden cannon ball can fly only a fraction of the distance of an iron one; and an equal weight of musket balls, propelled by the same charge of powder, will not reach near so far as the cannon ball, because of its consolidation in one body; and a feather or little toy balloon can not only not be propelled, but will actually recoil if attempted. Hence, all flying animals are many hundred times heavier than air, and the heaviest are generally the best flyers, yet require the least amount of surface and force in proportion. The sympathy existing between weight and power is very great. Weight acts in flight upon the oblique surfaces of the wings in conjunction with the power expended, and thereby husbanding the latter immensely. Thus only are the denizens of the air enabled to perform long journeys, while otherwise they could retain their position in the upper region but a very brief time, as their strength is no greater than that of other animals and would soon give out. Weight acts on flying creatures in a similar manner as we see it in the clock, where weight is the moving power, and the pendulum merely regulates its movements. Of course, the belief of many, that birds have large air cells in their interior, that those cavities contain heated air, and that this heated air in some mysterious manner contributes to, if it does not actually produce, flight, falls to the ground upon the least reflection. No argument could be more fallacious. The bird is a heavy, compact, by no means bulky body, and that trifle of heated air, or gas, if such were the case, but is not, which possibly might help elevation, would be but dust in the scale. A small balloon of two feet diameter--a larger body than any bird--can lift only about a quarter of a pound. But, besides, many admirable flyers, such as bats, have no air cells; while many animals, never intended to fly, are provided with them. It may, therefore, be reasonably concluded that flight is in no way connected with air cells, and the best proof that can be adduced is to be found in the fact that it can be performed to perfection in their absence. XIV.--SURFACE. The next of the three properties necessary for flight, is the extension of the locomotive organs in winged beings--the planes. Although the wings in the different animals differ much in their form, texture, construction, number, and the matter which composes them, yet they resemble one another in the expansion and development of their surfaces, being stretched on each side of the body, and playing the part of a parachute. The animal, therefore, cannot fall like a stone, in obedience to the accelerated force of gravity, but it descends with a slow velocity; constant regular, and considerably abated. This influence, then, exercised by the flat surface on the fall of masses, is seen in a sheet of paper of the same weight as a grain of lead, it will fall much more slowly. But if we make the paper a compact ball, and flatten the lead into a broad, thin sheet, the reverse result will be produced, and the paper reach the ground before the lead. Therefore, bodies in the air are light or heavy in proportion to their surfaces, and the heaviest may become light by an alteration of form. For successful flight, then, a just proportion of surface and weight is necessary; because, as stated, the air being elastic, its resistance is much more effectual with light bodies than heavy ones; and this proportion is such that the extent of surface is always in an inverse ratio to the weight of the winged animal. The principle in the fall of flat surfaces is strictly applicable to the bird. Its weight, tending downwards, and being situated below the plain of suspension, keeps it well balanced, so that it cannot fall head over heels, nor rapidly. If the wings are inclined at an angle with the horizon, the bird will not descend vertically, but glide along an inclined plane with much greater swiftness, because the vertical distance remains unaltered in the same space of time. Hence their immense horizontal velocity, without comparatively any effort. This is in obedience to two forces--gravity, or weight, and resistance of surface. XV.--POWER. But for actual flight a third force is required--the propelling power, the necessary amount of which has greatly been overrated by many mathematicians. Borelli estimated the power of a three pound bird to be over one hundred and thirty horses relatively. But, Navier, more reasonably, calculated a force of five horses sufficient for the flight of a pigeon. Coulomb, again, offset this "great liberality" by demonstrating that the surface to support a man must be two miles long and two hundred feet wide, with the power of a "Corliss engine" to propel such a "fifty acre ranch." Now, facts prove that man can, without danger, descend from an high elevation under a surface of much less than fifteen feet diameter; and the force to lift himself, as will be shown hereafter, is also comparatively small. He can walk up stairs, and likewise mount upon air, which, properly manipulated, becomes sufficiently solid. It has been demonstrated beyond a doubt, that the heaviest flying animals require the smallest amount of surface and power in proportion. The surface is less, because the resistance of the atmosphere is much greater toward one unbroken body than all the parts thereof if detached. Hence a stork, weighing eight times as much as a pigeon, needs only five square feet of surface, while the eight pigeons, with nearly one square foot each, possess together over seven square feet; and the common fly, if magnified to the size of the crane, would show a surface sixty times as large. The heaviest flyers require the least amount of power, because weight, as stated before, itself is power, which increases in a certain ratio. Hence we find the muscular force of the smaller beings, who possess little weight, to be enormous; this is particularly so with insects, who are the strongest in creation. A stag-beetle, of which two hundred weigh only one pound, can lift fourteen ounces; crickets leap eighty times their own length, and the "lively flea" can jump through space estimated at even two hundred times the length of its body--which accounts for the difficulty of catching it. If a mouse would simply reproduce the gait of a horse, its progress would be about twenty inches per minute only, and cats would soon find themselves out of employment. Nature has wisely established a compensation to make amends for the diminutiveness of organs by rapidity of movement, and has, consequently, furnished the animal with the necessary power to produce this rapidity. The force necessary for lifting in all winged beings is not near so great as is generally supposed. The fall of a body, continually accelerating, is seventeen feet per second, and a very great force would be necessary indeed to offset this gravitation, if that second were allowed to expire without a counter-movement; but when that body is provided with a parachute-like arrangement, there is no such rapid fall of seventeen feet per second; and when, besides, the force is applied constantly, thereby counteracting even a fraction of the fall, the power needed to accomplish this is but a trifle; it is the principle, to use a homely phrase, that "a stitch in time saves nine." What extra strength the animal possesses has to be used in pursuit or escape, from the powerful eagle to the minutest insect; they must be prepared to exert at a given moment all the strength that nature has given to them in store. Their strength is no greater than that of fishes or quadrupeds; all possess surplus power greatly above the need of their average use, and the strength exhibited therefore by flying creatures shows only that but a small portion of it is used for lifting and propelling purposes. Eagles have been known to carry off small deer, lambs, hares, and even young children. Many of the fishing birds, as pelicans and herons, can likewise carry considerable loads, while the smaller birds are capable of transporting comparatively large twigs for building purposes. A swallow can traverse 1000 miles at a single journey, and the swift, the fastest of all, is known to have made nearly 180 miles an hour. The albatross, despising compass and land-mark, trusts himself boldly for weeks together to the mercy or fury of the mighty ocean; and the huge condor of the Andes, as Humboldt, Darwin, Orton, and others inform us, lifts himself to a hight where no sound is heard, and from an unseen point surveys, in solitary grandeur, the wide range of plain and mountain below. He has been seen flying over the Chimborazo, and attains, on occasions, an altitude of six miles. XVI.--FLYING CREATURES, THEIR PROPORTIONS, MOVEMENTS. The great common characteristic of the different winged beings are the same throughout all the modifications of detail. These are, as stated, weight, extension of surface, and the mechanical application of the propelling force; so that the animal is a gliding plane, part of which is fixed and the other moveable, and the whole being maintained in stable equilibrium by the weight of the body, placed a little below the plane of suspension. By comparing the different species it is found, by M. de Lucy and others, that the extent of surface is in inverse ratio to the weight, the determination of this ratio being based upon certain considerations. The proof of this is overwhelming. Supposing all flying creatures of the same weight, say one pound, it is found that the: Gnat possesses 50 Common fly 22 Bee 5 Beetle 4 Sparrow 3 Pigeon 1-2/3 Stork nearly 1 Vulture 3/4 Crane nearly 1/2 Square feet of surface per pound. Thus we find the gnat, of which 160,000 make one pound, and which weighs four hundred and sixty times less than the beetle, has thirteen times more surface, comparatively. The sparrow weighs about ten times less than the pigeon, and has twice as much surface in proportion. The Australian crane--one of the heaviest birds, it weighs over twenty pounds, or almost three million times as much as the gnat--possesses the least surface--not quite ten square feet, or one hundred and twenty times less than that insignificant but formidable animal. Yet its flight is, gliding softly on the air, without effort or fatigue, with but little exertion, the longest maintained, and it can, with few exceptions, elevate itself the highest. In regard to the movements of the wings, there is a similar ratio; for, while the mosquito makes over two hundred wing strokes per second, the sparrow makes only thirteen, the buzzard three, and so on, continually decreasing with heavier bodies. A word about bats and flying fish. Although bats present no real resemblance whatever to birds or insects, but are much more like ourselves, they must be classed amongst the creatures of the air, because they are constantly moving in it, and governed by the same laws. Their flight, being somewhat fluttering, but otherwise powerful, true and perfect, is undoubtedly caused, particularly in the early part of the night, when feeding, by their darting right and left after the almost invisible numerous insects, which they devour at once. The wing of the bat is, like that of the bird, concavo-convex, and also more or less twisted upon itself, but it differs in so far that its arm is not covered with feathers, but a very delicate membrane, which forms the parachute-like wing. Their nocturnal, and therefore disreputable habits, with our dislike for the blood-sucking propensity of a large specie, the vampire, has kept our interest in these otherwise harmless and clean creatures at rather freezing point. But they can be tamed easily, and are capable of giving considerable pleasure. The flight of a shoal of flying-fish as they shoot forth from the dark green wave in a glittering throng, gleaming brightly in the sunshine, is a charming sight. But these fish can scarcely be classed with the creatures of the air, because true flight, that is the manipulation of the wings, is lacking. They are mentioned because they represent, like the kite, the first step toward that true flight which all other creatures in the air possess. They are capable of moving through the air from 500 to 600 feet, and as much as 20 feet above the water. The fish first acquires initial velocity by a preliminary rush through the water, when it throws itself suddenly into the air, and, at the same moment, spreads out, kite-like, at a slight inclination upwards, its extraordinarily large pectoral fins. It keeps up the great speed until its momentum is exhausted, when the same performance is repeated. The fact in favor of mechanical flight is certainly incontrovertible that less surface and less power is required and flight maintained the longest, in proportion to heavier bodies. It must be convincing, therefore, that it is possible for man to apply the laws of flight to industrial purposes in the same manner as he has been able, in these days, to apply all the other grand physical laws that he has taken the trouble to study and fathom. The law of surface and force reigns in the most absolute and exact manner over all flying animals. It does not stop here. Nature, whose laws are general and universal, has not created this one only for the restricted compass of the winged animate beings. The law which sustains on the water the leaf and the straw is the same for the gigantic Great Eastern; and the mechanical law of the forces which drives the wheelbarrow also conducts on its iron line the locomotive and its endless train. XVII.--MECHANICAL PRACTICABILITY OF ARTIFICIAL FLIGHT. Living beings have been, in every age, compared to machines, but it is only in the present day that the bearing and justice of this comparison are fully comprehensible. Modern engineers have created machines which execute more difficult and various operations than animate beings are capable of; yet it is always from nature first that man has to draw his inspirations. Of the different functions of animal mechanism, that of locomotion is certainly one of the most important and interesting; and as we have brought this art on land and water, by successfully imitating the natural movements of walking and swimming, to quite a high state of perfection, the next great problem, equally possible, because flight is a natural movement, remains to be solved. Of course, as different as the wheel of the locomotive is from the limb of the quadruped, and the screw of a steamship from the fin of a fish, so will the coming flying machine differ from the construction of bird, bat or insect. Walking, swimming and flying are modifications of, and merging into, each other by insensible gradations; and the modifications, resulting therefrom, are necessitated by the amount of support afforded on, and in the different mediums--earth, water, air. Although flight is, indisputably, the finest of the different animal movements, yet it does not essentially differ from the other two, as the material and forces employed are literally the same as those in walking and swimming. Flight is, therefore, a purely mechanical problem, and in compliance with the law of decrease, as stated before, the surface requisite to transport bodies in the air, is found to be about one-half, proportionately, to twelve times the weight. Applying this observation to an apparatus of, say 200 [lb]s., we find that the surface of a bird of 18 [lb]s.--about one-twelfth of said 200 [lb]s.--to be 10 square feet; multiplying this by twelve, its weight, we have 120 square feet of surface, and of which one-half accordingly, 60 square feet, is enough for the support of 200 pounds. Such a machine, although possessing much less surface than parachutes generally do, is in the form of inclined planes of proper construction, fully sufficient for man to slide down safely through the air, without exertion, from an elevation at least ten times the vertical distance, that is, from the top of the Palace Hotel to the foot of Baldwin's. As to the force required, although impossible to give datas, the law of decrease with greater weight reigns absolute here also. Man's muscular power for tolerably swift horizontal flight is far greater than necessary; and, with properly constructed contrivances, he will be able to travel, at an incline upwards of one in thirty, at least twenty miles an hour, by manual power alone. A carrier pigeon flies, for a short time, at the rate of one hundred miles an hour, and some birds much faster. But in employing any of the many excellent motive powers at command now, and with larger machines, we will be able to surpass the swiftest birds. As for the objection, that the fury of the wind will hinder artificial flight, it is refuted by observing that even a hurricane, which, traveling over eighty miles an hour, occurs but rarely, does hardly prevent the flight of fast birds, and still less would that of a compact and solid flying machine, because of its greater weight and momentum. And even if an occasional storm should be dangerous, the machine, by its greater swiftness, could be turned above, below or sideways, out of the path of destruction, or it need not travel at such rare times. Besides, the effect of the storm upon a body within its own medium is insignificant to what it is when that body offers resistance by being attached to another medium, as ships on the water, or houses and fences on land. XVIII.--FLYING MACHINES OF THE PRESENT, THEIR DEFECTS. When it was found that no marked improvements could be made in balloons, the more advanced thinkers, turning their attention in an opposite direction, commenced to justly regard the winged being as the true model for flying machines; and experiments are now being made, in different parts of the world, of which all go to prove that "_flight is far more a question of mechanical adaptation, construction and manipulation, than of enormous power_," which, of course, in any experiment, must prove unavailable, if improperly applied. Some of the motive engines, lately exhibited in England, produced such remarkable power as certainly no bird possesses. One of four-horse power weighed 40 pounds, and occupied but a few cubic feet; another of 13 pounds exerted over one-horse power; and, at some experiments in France last year, a steam engine of two and a half horse power weighed 80 [lb]s.; and, being applied to a machine with two vertical screw propellers of 12 ft. diameter each, it raised 120 [lb]s. of the whole weight of 160 [lb]s. But, as far as known, these different motive powers have been employed so far only to elevate and propel machines by vertical fan-like contrivances--helicopterics or by æroplanes, pushed forward and upward by screw propellers; either quite as irrational as ballooning, because the rigid plane, wedged forward and upward at a given angle, in a straight line, or in a circle, does not embody the principles carried out in nature. Hence, the several advocates of the æroplane and helicopteric have met with but indifferent success. Perhaps the best representative model of a flying machine on the principles of inclined planes, was that of Mr. Stringfellow, exhibited in London, in 1868, and which occasionally could rise. It had three æroplanes, superimposed as advocated by Wenham, the frames of which were made of light wood, with cloth drawn over it tightly, like rigid kites, fixed parallel one above the other, with a tail attached to the middle one. It had a small box underneath for the motive power, and a light screw propeller behind for pushing it forward. By giving the machine an upward angle, the planes strike continually upon new layers of air, and so cause a rise, like a kite pushed from behind. The whole structure had about thirty-six square feet of surface, and weighed, including the steam engine, which exerted nearly one-half horse power, under 12 pounds. It proved conclusively that, while the inclined plane, in a practical and different form, is necessary for ærostation, the secret of solving the problem lays far more in the mechanical application of certain laws governing the art of flight, than in enormous power. These kite-form machines did not succeed, in spite of their great motive power and lightness, because the supporting planes were not active and flexible, but presented passive or dead surfaces, without power to accommodate themselves to altered circumstances. These planes were made to strike the air at a given angle, instead of continually changing to suit the elastic medium, and in which respect the ordinary kite is a better flying machine. If not driven with great velocity, such a machine can not support itself in the atmosphere; besides, on account of its great surface exposed, a strong wind can easily capsize it; while natural wings, on the contrary, present small flying surfaces, and their great speed converts the space through which they are driven, into a solid basis for support. This arrangement enables wings to seize and utilize the air, and renders them superior to the adverse currents, not of their forming. In this respect they entirely differ from balloons, and all forms of fixed æroplanes. The different small helicopteric models, relying entirely on the aid of the screw, made from time to time, were also lacking, as stated before, in some of the true principles of flight; although some of these models could not only rise, but also carry a certain amount of freight, as was shown by the delicately constructed clockwork models of M. Nadar, a prominent French scientist, and others. One remarkable model, exhibited some years ago, was that of M. Phillips. It was made entirely of metal, weighed two pounds, had four two-bladed fans inclined to the horizon at an angle of twenty degrees, and made to revolve in opposite directions with immense energy. The motive power employed was obtained from the combustion of charcoal, nitre and gypsum, the products of combustion mixing with water in the boiler and forming gas-charged steam, which was delivered at a high pressure from the extremities of the arms of the fans, on the principle discovered by Hero, of Alexandria. The production of flight by artificial wings is the most ancient method proposed, and will, undoubtedly, in a greatly modified form, and in combination with other contrivances, solve the problem; but to exactly imitate natural wings will be found as impossible as the production by the other different methods proposed so far. Of the more recent attempts at the solution of the problem by means of artificial wings, worked by steam power, the perhaps most determined was that of Mr. Kauffman, of Glasgow. The machine had superimposed æroplanes, similar to those used by Stringfellow. The two wings were of great length, narrow, pointed towards the end, and were made to flap up and down somewhat like the wings of a bird. The model exhibited weighed, complete, 42 [lb]s., but the dimensions for a large machine were to be: length, about 30 ft.; hight, 5 ft.; width, 6 ft.; length of each wing, 60 ft.; surface of each, 400 ft.; total weight of machine, 8000 [lb]s.; nominal power, 120 horses; intended speed, 60 miles per hour; with water supply for five hours and oil as fuel for ten hours. Besides, a pendule, weighing 85 [lb]s., and 40 ft. in length, was attached, which could, telescope-like, be drawn up when necessary. The model was made exactly, to show the inventor's theory, and to ascertain if the connection to the wings could be made strong enough to withstand the violent twisting and bending strains to which they were exposed. When steam at a pressure of over 150 [lb]s. was turned on, the wings made a short series of furious flaps and broke. The experiment failed, because, to exactly imitate the movements of the long and delicate wings of fast-flying birds on a large scale, is impossible; the leverage to flap up and down 60 ft. long wings being simply enormous beyond computation, and no material can be found strong enough to withstand it. Another machine, the propulsion of which was also to be effected by means of artificial wings, was exhibited some years ago in England. It differed entirely from the other in this respect, that it was very light, weighing scarcely 30 [lb]s., and was intended for a man to fly by his own muscular power. It had about 70 square feet of surface, two short wings, and the ribs were made of paragon wire, such as is used in umbrellas, and covered with silk. By a preliminary quick run, the inventor could take short, jump-like flights of more than 100 feet; but this machine was also in a very crude state of perfection. These different practical experiments, although more or less unsuccessful, and others similar, but of which many models were far more ingenious than practical, have at least established the certain prospect and certainty of an early solution of the problem. And were it not that but very few, comparatively, of the great number of theories, which have been proposed from time to time for the accomplishment of this great object, have been submitted to anything resembling even the remotest approach to practical tests, and that the lack of means is generally the insurmountable barrier in experimenting, ærial navigation would to-day be an established fact. XIX.--THE PRACTICAL FLYING SHIP OF THE NEAR FUTURE. Possessing then, all the datas possible on the subject, it is, perhaps, not so very difficult as is generally supposed, to arrive at a satisfactory result; and, like other great inventions before, the coming air ship will also be a rather simple affair. While it will not likely possess such prodigious weight as 8000 to 10,000 pounds, with a hundred and twenty horse-power steam engine--sufficient almost for a man of war, it will neither be as light as a feather, comparatively, but hold the golden middle. The inclined planes, in a greatly modified form, will by no means be discarded, as in fact no flying machine could be built otherwise. But, as stated before, this is only one principle long recognized, the A B C, so to speak, towards the solution of the problem. These planes, in wedging forward, for certain reasons, should be _elastic_, in some manner, and which has not been attempted by any inventor yet. The frames and covering of all models, built so far, have been rigid and immoveable, and yet, even with these great defects, partial success has been obtained already. The fan or screw never will be used as the _only_ means in propelling, but will be very effective in doing service as a part of the whole, with other contrivances in driving and guiding. But their form and style must be considerably different from anything known at present. A modified and peculiar form and style of wings, as mentioned here before, must also be employed in combination with the planes and fans, to serve the double purpose of driving and lifting. By the manipulation of these wings the accumulating and compressed air is thrown underneath the machine, thereby urging the same in a forward and upward direction, and by which the planes in front are made to continually rise upon new layers of the elastic medium, like a kite when the boy runs forward. The planes must be fixed in such a manner that they can be set at different angles with the horizon, in order that the machine may rise sooner when the angle is greatest, because of the greater resistance of the air against a larger surface exposed; and to glide through the atmosphere swifter, after elevation has been attained, when the angle of the planes is most acute, thereby offering the least amount of surface to the horizontally opposing air. No flying creature rises in the air vertically, but ascends at an incline. A swallow, one of the very best flyers, lifts itself with difficulty from the ground. An eagle, particularly after eating, has to run some distance flapping its wings vigorously before it can rise. An insect, possessing considerable spring-power in its limbs, always takes a good jump at the moment its wings are spread out for elevation, at an upward angle forward. With similar contrivances for the purpose must a practical flying machine be provided. It should, in combination with a certain amount of spring power, to enable it to rise with greater ease at the final moment, and also to reduce the shock in alighting to a minimum, have wheels to run over the ground, until sufficient force and momentum has been attained to launch it into the boundless realms of space. To be thoroughly practical, the machine must be under perfect control, and be made to descend upon any spot desired with absolute safety and ease. This can be accomplished by the combined effort of the propellors and wings. By exerting the power of these contrivances in opposite directions the disturbed atmosphere is thrown in volumes underneath the machine, which, on account of its similarity to a parachute, although of a greatly different form, can be made to descend vertically and very slow. The doubt expressed by many, that the guidance of an air ship is possible, is easily refuted. All bodies, possessing the propelling force within them, can guide themselves in an elastic medium. Of this we have millions of examples before us in all flying creatures. Finally, a practical shape and proper size and weight will form one of the most essential elements in a successful flying machine, and which has been disregarded more or less so far. Of course, it is impossible to calculate already, before an actual machine has been built and datas can be fixed, the limits of these factors in the average ærial structure. My impressions are, that the weight of a single carriage will be from 400 to 500 lbs., inclusive; a motive force of 3 to 5 horse power. It will have a total length of from forty to fifty feet, by about the same in width, from tip to tip; and a surface of from 500 to 600 square feet will be more than sufficient to sustain a total weight of 1000 lbs.; for such a machine will be capable to carry from three to four persons, or its equivalent weight of express matter, letters, newspapers, and other light freight. Of course, free mail facilities for our wise solons will, perhaps, unfortunately have to be barred out. When the novelty and excitement of this style of travel will have subsided, we may take the next step in ærostation by carrying a much greater number of passengers and heavier freight; not in a single machine, but by making two or more to support inclined planes of certain construction between them. These planes, in swift horizontal flight, could be made to carry, in suitable cars underneath, much more than their own weight, because the power of support which the air affords to inclined planes at a great speed is simply enormous, amounting to 50 [lb]s. per square ft. in a pressure of 100 miles per hour. For this purpose, the manner of placing these æroplanes one above the other, as proposed by Mr. Wenham many years ago, would be practical to some extent. The great swiftness with which these machines are expected to travel, seems at first to rouse fear in us to trust our more or less valuable lives into such a wonderful structure; and it possibly staggers our belief that such great speed can be performed with any degree of safety to brittle bone and breathing valve. But all these objections are easily refuted. The ærial traveler sits securely inside the strong machine, in no danger of catching a cold from the strong air-current rushing by, very much like the passenger in a railroad car; and if of an inquisitive turn of mind for the beauty of the surrounding panorama, he has suitable windows for observation. If the air passenger suffers from gout, rheumatism, or is susceptible to sea-sickness, he will experience no inconvenience, because there is no jogging, no rumbling over cobble-stones or broken rails, or riding on a heavy sea; he will feel no motion at whatever hight he may be, but will glide voluptuously--without perception almost--like a summer cloud through the vast ocean of the ærial fluid. The machine being under perfect control, can be made to travel very slow when towards the point of destination, and may be stopped at any hight to remain stationary or leisurely descend. And lastly, speed appears greatly diminished when the object is viewed from a distance, as we can observe on a railroad train. A telegraph pole standing near the track will flit by like a flash of lightning, so to speak; but if any considerable distance off, it disappears very slow. But when an object is followed by the eye from a considerable elevation, this fact is still more striking. The eye can command at a glance almost hundreds of miles of country, and a city can be seen at a distance of at least fifty miles in advance, giving the æronaut ample time for preparing a descent, if so desired. Of course, he must be well acquainted with landmarks, to know what part of country he is in; but this knowledge will be acquired much easier than water navigation. Such about will be the coming flying-machine of the near future. The natural elements, so far from presenting barriers and obstacles, as they do to a great extent on land and ocean navigation, seem to be peculiarly inviting to ærostation. Previous to nearly every great discovery, difficulties have been thought to exist which its completion dissolved. In the days of stage-coaching, the expectations held out by those interested in steam transport were considered, even by most competent and intelligent men, as wholly chimerical; yet the locomotive far surpasses the race-horse in speed and endurance. When practice proved and datas could be fixed, that smooth tires met all the requirements on railroads--in place of cogwheels to gear into racks--how easy all calculations on adhesive force and friction then became. So with flight. XX.--WHAT THE CHANGES FOR THE BETTER WILL BE. It is impossible to overestimate the benefits which will accrue to mankind from such a creation. Flying will become a studied art, an amusement, an accomplishment, and inconvenience from sultry heat, or freezing cold, or deadly epidemics will no longer be suffered. Flying will become a business, a trade, and the advantages derived from it for industrial purposes will be wonderfully great. New channels of employment will be opened to thousands, yes, millions of starving fellow-beings. A new era will be inaugurated in history; and great as has been the destiny of our race, it will be quite outlustred by the grandeur and magnitude of coming events. Traveling at a speed of over one hundred miles an hour, distance will become comparatively annihilated. Cutting through the air from San Francisco to New York, for instance, in twenty-four hours, at one-sixth in cost and time; far safer, because of no irregulations nor obstructions of road, no snow-blockades or unnecessary delays; far cheaper, because of no great expense for outfit or maintenance, the ærial carriage will soon become the great means of travel throughout the world. The vast uninhabited but productive regions of this globe will be populated from overcrowded and impoverished communities, because of the extraordinary cheap, safe, and rapid travel by flying machines. New life will again be imparted to enterprise, speculation and labor; and lands will be cultivated and great cities be built in regions where the foot of human being has not trod for ages. The Andes and Rocky Mountains will become as familiar to us as the hills of our own city; and mining and other discoveries will follow each other with wonderful rapidity. The vexing and expensive explorations in the interiors of Africa and Australia, and towards the North Pole, will soon be brought to a speedy and satisfactory conclusion; and some of the wildest dreams of men be realized. XXI.--CONCLUDING REMARKS. The accomplishment of ærial navigation, then, is within reach; its practicability can no longer be denied. It will be one of the most glorious and fruitful conquests, and of the highest value and importance to civilized nations. But all inventions, and particularly an undertaking of such gigantic nature, require pecuniary assistance. This should not, in our age of progress, be lacking for a single moment; because, if for no other reason, the first promoters of it will reap such great financial benefits therefrom as must be beyond their calculation. Singer, Howe, Colt, McCormick, and hundreds of others, all, with thousands of friends so immensely wealthy, bear out this assertion. Let not this enlightened age look upon a great invention as was done in Robert Fulton's time, when he proposed the steamship to Napoleon in 1801. The plan was laid before a scientific commission, and these learned men reported it as "visionary" and impracticable. Such was the reception which steam navigation, that has achieved such immense results, first received at the hands of philosophy and capital; but France lost thereby, indirectly, the control of Europe, and Napoleon his crown; while another nation--America--more wise, ten years later commenced to reap the benefits emanating from Fulton's genius. Means, then, being necessary for the accomplishment of this great object, let them be forthcoming at once, that California may enjoy the honor and the first fruits of this great invention. In conclusion, let me thank you for the kind attention you have bestowed upon a weak exponent of a great subject. Transcriber Notes Passages in italics were indicated by _underscores_. Small caps were replaced with ALL CAPS. Throughout the document, the oe ligature was replaced with "oe". Errors in punctuations and inconsistent hyphenation were not corrected unless otherwise noted below: On page 4, Koenigsberg was replaced with "one from Koenigsberg", and "some days ago" was replaced with "some days afterward", both per the Errata page. On page 7, "gass" was replaced with "gas". On page 10, "nade" was replaced with "made". On page 12, the comma after "M" was replaced with a period. On page 13, "indiscribable" was replaced with "indescribable". On page 13 "aeronaut" was replaced with "æronaut". On page 14, the semicolon after "eye can reach" was replaced with a comma. On page 14, "posititons" was replaced with "positions" On page 15, "intensily" was replaced with "intensely". On page 16 "aeronaut" was replaced with "æronaut". On page 22, "charletans" was replaced with "charlatans". On page 25, "strenght" was replaced with "strength". On page 28, "XI" in the chapter title was replaced with "XV". On page 31, "XVI.--" was added in the chapter title. On page 31, "by" was replaced with "fly". On page 34, "opperations" was replaced with "operations". On page 35, "meahanism" was replaced with "mechanism". On page 36, the "lb bar symbol" (called the "pound sign") was replaced with [lb]. Sometimes, through the book, the author used the "lb bar symbol" and other times the author used "lbs." On page 39, "æorastation" was replaced with "ærostation". On page 44, "horrizontally" was replaced with "horizontally". On page 45, "air-ship" was replaced with "air ship". On page 49, "anihilated" was replaced with "annihilated". 
37863	----	ESSEX TERRAPLANE SIX 1933 Owner's Manual of Information Printed in U. S. A. Warranty "We warrant each new passenger automobile manufactured by us to be free from defects in material and workmanship under normal use and service, our obligation under this warranty being limited to making good at our factory any part or parts thereof, including all equipment or trade accessories (except tires) supplied by the Car Manufacturer, which shall, within ninety (90) days after making delivery of such vehicle to the original purchaser or before such vehicle has been driven 4000 miles, whichever event shall first occur, be returned to us with transportation charges prepaid, and which our examination shall disclose to our satisfaction to have been thus defective, this warranty being expressly in lieu of all other warranties expressed or implied and of all other obligations or liabilities on our part, and we neither assume nor authorize any other person to assume for us any other liability in connection with the sale of our vehicles. "This warranty shall not apply to any vehicle which shall have been repaired or altered by other than an authorized Hudson and Essex Distributor or Dealer in any way so as, in the judgment of the Manufacturer, to affect its stability or reliability nor which has been subject to misuse, negligence or accident." HUDSON MOTOR CAR COMPANY Detroit, Michigan, U. S. A. INDEX General Page BREAKING-IN INSTRUCTIONS, 3 CAPACITIES OF UNITS, 14 CARE OF FINISH, 15 LAMP BULB TYPES, 14 LICENSE DATA, 14 STARTING THE ENGINE, 4 WARRANTY, 1 Lubrication CHASSIS, 7 CLUTCH, 5 DISTRIBUTOR, 8 DOOR DOVETAILS, 8 DOOR LOCKS AND HINGES, 8 ENGINE, 5 FAN, 8 GENERATOR, 7 LUBRICATION SERVICE, 15 REAR AXLE, 6 STEERING GEAR, 7 TRANSMISSION, 6 WHEEL BEARINGS, 6 Adjustment ADJUST DISTRIBUTOR POINTS, 9 BATTERY, 14 BRAKES, 11 CARBURETOR (SEE ENGINE TUNING), 9 CLUTCH PEDAL, 11 ENGINE TUNING, 9 FAN AND GENERATOR BELT, 10 FRONT WHEEL ALIGNMENT, 15 FRONT WHEEL BEARINGS, 12 GENERATOR CHARGING RATE, 14 IGNITION TIMING, 9 RADIATOR (COOLING SYSTEM), 15 REAR WHEEL BEARINGS, 12 SHOCK ABSORBERS, 15 SPARK PLUGS, 14 SPRING CLIPS, 15 TAPPETS, 15 TIRES, 15 WHEELS (REMOVAL AND INSTALLATION), 12 WIRING DIAGRAM, 13 Operation Breaking-in Instructions Keep Radiator Full Keep Oil Reservoir Full Heat is a major consideration in a new engine. Do not allow the engine to overheat. Although the heat indicator on the instrument panel shows the general temperature of the engine, it will not show a sudden rise in temperature of an individual part. The pressure imposed on parts such as bearings and pistons due to rapid acceleration or hard pulling will cause them to overheat if the car has not been driven sufficiently to break them in. Avoid fast acceleration and hard pulling while breaking in. High speed also develops higher operating temperatures and to avoid damage the car speed should be kept within the following recommendations: 0-250 MILES Do not exceed 40 miles per hour in high gear or 20 miles per hour in second. Do not accelerate rapidly. Use second gear on steep grades. Keep motor temperature within "driving range" on dash heat indicator. 250-500 MILES Do not exceed 50 miles per hour in high gear or 25 miles per hour in second. 500-1000 MILES During this period the speed should not exceed 60 miles per hour. IMPORTANT Do not UNDER ANY CONSIDERATION attempt to maintain a high rate of speed unless the crankcase is full of good oil and until the engine is thoroughly warmed up. Cold oil is not able to flow freely into the small clearances between working parts so that damage may occur if sufficient time is not allowed for warming up before attempting high speeds. [Illustration: OIL SIGNAL, CLUTCH CONTROL, GENERATOR SIGNAL, STARTER, LIGHTS, IGNITION, CHOKE] Starting the Engine If the engine is cold, pull the choke knob out as far as possible, turn the ignition switch key to the right, depress the accelerator pedal slightly, and pull the starter knob out. When the engine "fires," push the choke knob in until the engine runs evenly. Return the choke knob gradually to the full in position as the engine warms up. The choke knob should never be out any farther than necessary to maintain even running of the engine. If the engine is warm from previous running, use the choke sparingly. In most instances the engine will start immediately without the use of the choke if the accelerator pedal is held in a slightly depressed position while the starter is used. Do not under any circumstances work the accelerator pedal rapidly when starting as the accelerator pump may flood the carburetor. =Oil Signal=--The red signal on the left hand indicates oil pressure and the functioning of the oiling system. It will glow when the ignition switch is turned on but will go out when the car is under way. Should it continue to burn or flash while the car is under way, it indicates that the oil supply is low or that the oiling system is not functioning properly. Do not run the engine until the oil supply has been replenished or trouble corrected. =Generator Signal=--The red signal on the right hand will light when the ignition switch is turned on and will be lighted at all times unless the engine is running at higher than idling speed. Should this signal glow at normal running speeds, it indicates that the generator is not charging and should be inspected immediately by an Essex dealer. Lubrication Engine Use High-Grade Oil--Medium Heavy Body (S.A.E. 30) [Illustration] If cold weather prevails, be sure the oil you use will flow at the temperatures encountered. Oil supply should be maintained at the full mark on the bayonet gauge at the oil filler. The frequency with which oil should be drained and replenished with new depends largely on the operation of the car. Consult your dealer for recommendations on your car. In any event the oil should be changed at least every 2500 miles. Clutch [Illustration] Use only a mixture composed of 1/2 kerosene and 1/2 engine oil. Turn starter shaft with wrench, moving wrench handle toward the engine until plug "A" is accessible through opening in rear engine plate. Remove plug "A," continue turning flywheel until opening is down and all clutch oil is drained. Then turn until opening is again accessible. Pour in by means of offset funnel no more than 1/3 pint of clutch mixture. Replace plug "A" and tighten securely. The clutch oil should be drained and replenished at least every 5000 miles. The clutch throwout bearing should be lubricated with one ounce of light viscous grease[A] every 500 miles. A pressure fitting is provided on the right side of the clutch bell housing. [Footnote A: _See page 7 for grease specifications._] Transmission [Illustration] The transmission lubricant should be maintained to the level of the filler plug "A." In warm climate or during summer months use transmission gear oil S.A.E. 110. In winter or when near-zero temperatures prevail use transmission gear oil S.A.E. 80. Remove drain plug "B" every 5000 miles, flush out with 1 pint of kerosene and refill with oil of proper type. Rear Axle [Illustration] The oil supply should be kept level with the lower edge of the filler plug opening "A." Use a good grade of heavy-bodied gear oil. S.A.E. 110 in warm climate (summer temperatures)--S.A.E. 90 when lower temperatures prevail (winter). During the winter months be sure the oil you are using will flow at the temperatures encountered. Wheel Bearings [Illustration] The front wheel bearings should be lubricated every 5000 miles with a good grade of cup grease. Remove hub and wash bearings and inside of hub with kerosene. Pack each bearing and hub with 3 ounces of No. 2 cup grease (see page 12 for adjusting wheel bearings). The rear wheel bearings should be lubricated every 5000 miles with No. 3 cup grease. Remove four nuts from bearing cap "A" and remove caps and shims. Pull bearing and after washing bearing and housing in kerosene repack each bearing housing with 1-1/2 ounces of cup grease. Then replace bearings, shims and caps, draw up wheel hub tight on shaft and install cotter pin. Steering Gear Summer S.A.E. 160 Winter S.A.E. 110 [Illustration] Remove plug "A" and pour a good heavy-bodied gear oil into the steering gear housing every 2000 miles. Do not use cup grease or you will experience hard steering in cold weather. Chassis [Illustration] All spring shackle fittings (12) should be lubricated every 1000 miles with a light viscous grease.[B] All pressure fittings on the front axle (4) and the steering gear drag link (2) should be lubricated every 1000 miles with pressure grease. The front universal joint sleeve splines should be supplied with a small amount of long fibre grease, through the plug provided, at 4000-mile intervals. [Footnote B: _Grease Specifications--4% Calcium Soap compounded with an oil of 400 seconds viscosity and a zero pour test._] Generator [Illustration] Supply three or four drops (no more) of engine oil to each oil cup "A" and "B" every 1000 miles. Do not attempt to supply more oil as it may interfere with the functioning of the generator. Distributor [Illustration] Fill distributor base with oil at cup "C" every 2000 miles. Coat rotor cam "A" with a thin film of vaseline every 2000 miles. Apply one drop (no more) of light oil to breaker arm pivot "B" every 2000 miles. Wipe excess oil and clean distributor head, removing oil or dust before returning to position. Be sure each high-tension terminal and wire on distributor head is pushed as far into its socket as it will go. Fan [Illustration] Fill fan shaft bearing with engine oil at oil cup "A" every 1000 miles. It is very important that the fan shaft has plenty of lubrication at all times. Miscellaneous =Throttle Control Rod=--Oil or grease all accelerator connections. Throttle linkage should work with a snap. Grease choke wire occasionally to eliminate sticking. =Door Locks=--Apply a drop of engine oil occasionally to latch bar. Work several times to spread oil, then wipe off excess. =Door Latch Striker Plate=--Saturate wick with motor oil. =Door Dovetails=--Saturate wick in male member with motor oil. =Door Hinges=--Open doors and drop light oil in each hinge oil hole, located under the top ledge of body portion of hinge. Wipe off excess. =Hood Locks=--Lubricate occasionally with motor oil. Adjustment Engine Tuning [Illustration] Do not attempt to adjust the carburetor alone. Perform all of the following operations in the order given: 1. Clean spark plugs and adjust gaps to .025" (.62 mm.). 2. Clean distributor breaker points and adjust to .020" (.50 mm.) maximum opening as described under Ignition Timing. 3. Check battery and ignition wiring, being sure _all distributor wires are pressed down in their sockets_. 4. Set ignition timing as described under Ignition Timing. 5. Adjust intake valve tappet clearance to .006" (.15 mm.) and exhaust tappet clearance to .008" (.20 mm.). 6. Turn carburetor idling screw "B" into its seat and back out exactly one turn. 7. Start engine. 8. Set carburetor throttle stop screw "A" so that engine idles at a speed equal to a car speed of 5 m.p.h. in high gear. 9. Adjust carburetor idling screw "B" for smooth engine idling. The final adjustment should be from 1/2 to 1 turn of the screw from its full in position. If the above operations, properly performed, do not give normal engine performance, the car should be taken to an Essex dealer for mechanical inspection. Ignition Timing [Illustration] Remove distributor cap and inspect points. High points can be removed by placing a breaker point file between points and letting them close against file under their normal spring pressure. Move file straight up and down, dressing both points at the same time. If the points are pitted, they should be ground or replaced. Crank engine, using wrench on starter shaft extension, until the breaker arm fibre block is on the highest point of the cam, giving the points their maximum opening. If necessary to adjust, loosen lock nut "D" and turn screw "E" until the gap is .020" (.50 mm.). Tighten lock nut. Remove the spark plug from number one cylinder. Crank the engine slowly by hand until air is forced out through the spark plug hole. Continue turning the engine slowly until the D.C. 1 and 6 mark is exactly in line with the pointer as shown at "A." [Illustration] Loosen distributor clamp screw "B" and turn distributor clockwise to the full limit permitted by the slot in the clamping plate "C." Turn the distributor counterclockwise until the points have just begun to open. Tighten lock screw "B." When the engine is in this position the rotor arm "F" will point directly to the sector in the distributor cap to which number one spark plug cable is connected. Following around the cap clockwise from this point the spark plug wires should be in the following order: 1-5-3-6-2-4. Fan and Generator Belt [Illustration] The fan and generator drive belt must be kept at sufficient tension to prevent slippage on the pulleys. Do not adjust too tightly or rapid wear on fan and generator bearings will result. To adjust belt tension, loosen nut "A" and swing generator away from engine to tighten. Then lock adjustment by thoroughly tightening nut "A." Clutch Pedal [Illustration] The clutch rod length should be adjusted so that the clutch pedal can be pushed down 1-1/2" before the clearance is taken up between the levers on the clutch cross shaft and the clutch throwout yoke shaft and further movement of the clutch pedal will begin to disengage the clutch. To adjust: Loosen lock nut "A," remove clevis pin "C" and turn yoke "B" to obtain proper length. Insert clevis pin and tighten lock nut "A." Brakes [Illustration] Unless you are an experienced mechanic, it is advisable to have your brakes adjusted by your Essex dealer. The following operation will, however, take care of normal brake shoe wear if done carefully: Jack up car, remove all four wheels and remove the inspection covers from the front of the brake drums. Disconnect the four brake cables from the cross shaft; turn the brake drum until the inspection hole is 1-1/2" from the adjusting screw end of the lining of the upper shoe (rear of front brakes--front of rear brakes). Insert a .014" (.35 mm.) feeler through the inspection hole. Loosen eccentric lock nut "A" and turn eccentric "B" in the direction the wheel rotates when the car is moving forward until the feeler is held snugly between the drum and the lining. Hold the eccentric in this position and tighten lock nut "A." Make this adjustment on all four brakes. Turn brake drum until inspection hole is 1-1/2" from adjusting screw end of the lining of the lower shoe (rear of front brakes--front of rear brakes). Insert a .008" (.15 mm.) feeler through inspection hole. Insert a screwdriver through opening "C" and turn star wheel until feeler is held snugly. Move the handle of the screwdriver toward the axle to tighten brakes. Make this adjustment on all four wheels. Reconnect the brake cables at the cross shaft, adjusting the position of the cable yoke so that the clevis pin can just be inserted in the yoke and cross shaft lever hole when the cable is held just taut enough to remove slack. If trial on road shows too much braking on one wheel, loosen that brake by turning star wheel with screwdriver one notch at a time until the brake is equal with the others. Always loosen the tight brake--do not tighten the loose brakes or the pedal travel will be restricted and may cause brake drag. Front Wheel Bearings [Illustration] After jacking up front axle and removing the hub cap, withdraw cotter key holding nut "A." Turn nut "A" to the right until a slight drag is felt when turning the wheel slightly by hand. Then loosen the nut just sufficiently to permit the wheel to turn freely. Insert cotter key. Rear Wheel Bearings [Illustration] To adjust rear wheel bearings, jack up rear axle and remove both rear wheels. Remove the four nuts from bearing cap "A" and remove cap. By removing shims "B" under the cap the end play of the axle shaft is decreased. Total play between axle shafts should be from .005" to .010" (.12 to .25 mm.) which is perceptible by pulling shaft in and out with the hand. It is necessary that the thickness of shims at each rear wheel be approximately the same, so when adjusting remove a thin shim from each side and repeat, if necessary, until only a slight amount of play is evident. Be sure the axle shafts turn freely before building up. Removing and Installing Wheels To remove a wheel, place a screwdriver between the hub cap and hub and pry off cap. Loosen the four cap screws "B" (illustration top of page) with the socket wrench provided. Remove one cap screw in the lowest position and insert the handle of the wrench through the screw hole into the hub. While holding the wheel in position with the wrench, remove the other cap screws and lift off the wheel. The wheels should be jacked up just sufficiently to clear the ground. When replacing the wheel, place the handle of the wrench through the lower cap screw hole, lift up on the wrench so that the wheel will clear the ground and push in place. Align by moving wrench back and forth. Then start two of the cap screws, remove the wrench and start the remaining two. Tighten every other cap screw until all are down enough to hold wheel in place, making sure it is square on the hub. Continue tightening every other screw until all are secure. [Illustration: OIL PRESSURE TELL TALE COIL DISTRIBUTOR IGNITION LOCK OIL CHECK VALVE TO STARTER TO COIL LIGHT DOME GENERATOR SWITCH LIGHT TELL TALE HORN HORN BUTTON TO DIMMER SWITCH TO TAIL AND FAN PULLEY INSTRUMENT RELAY LAMPS TO DOME LIGHT AND STOP LIGHT TO PARKING SWITCH STOP LAMP STARTER LIGHT SWITCH GENERATOR BATTERY TAIL LAMP DIMMER SWITCH SPEEDOMETER GASOLENE TANK GAUGE GAS & TEMP GAUGE WIRING DIAGRAM] General Information License Data CYLINDER BORE--2-15/16"--74.61 mm. STROKE--4-3/4"--120.65 mm. NUMBER OF CYLINDERS--6 N. A. C. C. HORSEPOWER RATING--20.7 H.P. PISTON DISPLACEMENT--193 cubic inches--3.15 liters CAR SERIAL NUMBER--Plate on dash under bonnet 106" Wheelbase--368,379 and up 113" Wheelbase-- 5,001 and up ENGINE SERIAL NUMBER--Stamped on left side (center) of cylinder block (25,131 and up) Capacities U. S. Imperial Metric RADIATOR AND COOLING SYSTEM 3 gals. 2.5 gals. 11.35 liters GASOLINE TANK, 106" Wheelbase 11.5 gals. 9.58 gals. 43.53 liters GASOLINE TANK, 113" Wheelbase 16 gals. 13.3 gals. 60.57 liters ENGINE CRANKCASE (REFILL) 6 qts. 5 qts. 5.68 liters CLUTCH 1/3 pint 1/3 pint 180 c.c. TRANSMISSION 3 pints 3 pints 1.4 liters REAR AXLE 3 pints 3 pints 1.4 liters Spark Plugs Size 14 mm. Set points at exactly .025" (.62 mm.). Replace after each 10,000 miles (16,000 kilometers) of service. Generator Charging Rate Generator is regulated by position of third brush. This should only be altered by competent service stations using accurate measuring instruments. Generator output { 17 amperes at 8 volts { 13 amperes at 6 volts Output to be measured at generator. Do not exceed the above rates. Battery Use only distilled water to cover plates. This should be done as frequently as found necessary. An average of every two weeks during the summer months (less frequently in cooler weather). Lamp Bulbs Candle Power Base Voltage HEADLAMP (DOUBLE FILAMENT) 21-21 Double Contact 6-8 PARKING (IN HEADLAMP OR ON FRONT FENDERS) 3 Single Contact 6-8 TELLTALES (ON INSTRUMENT BOARD) 3 Double Contact 6-8 INSTRUMENT BOARD 3 Single Contact 6-8 STOP AND TAIL LAMP (DOUBLE FILAMENT) 2-21 Double Contact 6-8 DOME 15 Single Contact 6-8 FUSE (AT LAMP 20 Amperes Engine _Firing order_ of cylinders--1-5-3-6-2-4. Tappets Adjust when engine is hot. Minimum clearances--inlet valves, .006" (.15 mm.); exhaust, .008" (.20 mm.). Counting from the front, intake tappets are 2-4-5-8-9-11 and exhaust tappets 1-3-6-7-10-12. Cooling System It is good practice to drain, flush and refill the cooling system occasionally. If freezing temperatures are encountered in your community, anti-freeze solution will be necessary during the winter months. Chassis Lubrication This book contains detailed information covering lubrication of all units. Spring shackles and steering connections equipped with pressure fittings should be lubricated every 1000 miles. Your Essex dealer will arrange to completely lubricate your car at regular intervals at small cost. Spring Clips The nuts on the clips holding springs to axles, front and rear, should be tightened every 5000 miles. Front Wheel Alignment The front wheels should have a toe-in of from 0" to a maximum of 1/8" (3.2 mm.) for 5.25 tires and 1/4" (6.4 mm.) for 6.00 tires. Have your dealer check the alignment occasionally and adjust if necessary. Shock Absorbers Shock Absorbers--Monroe. Have dealer fill with Monroe Cushion Oil every 2000 to 5000 miles. Tires Minimum Pressure Size Front Rear 17 x 5.25 28 lbs. 28 lbs. 16 x 6.00 21 lbs. 21 lbs. Care of Finish We recommend the use of Hudson-Essex Polish, which is procurable from your dealer. An occasional polishing will preserve the finish. A wax coating is recommended, providing the lacquer is thoroughly cleaned and prepared for the wax surface. Printed in U. S. A. S.H.--2500--7-33 * * * * * Transcriber's Notes All instances of S. A. E. have been changed to S.A.E. for consistency. Page 13: Retained spelling of gasolene in wiring diagram. 
49307	----	[Illustration: C. A. COEY'S SCHOOL OF MOTORING 1424-26 MICHIGAN AVE. CHICAGO] Our School is said to be the Greatest and Most Complete AUTO SCHOOL in the World and the only one ACTUALLY BUILDING AUTOMOBILES [Illustration] Lessons Compiled by C. A. COEY, President COPYRIGHTED 1912 [Illustration: Two Prominent Auto Racers BARNEY OLDFIELD to the left racing against C. A. COEY in Mr. Coey's famous Tornado on the St. Louis fair ground track. Mr. Oldfield won the race by the smallest margin that a motor car race was ever won, he being only six inches ahead at the finish.] To the Prospective Student If you are about to make your start in life, or not satisfied with your present line of work, or for the sake of your health are desirous of securing a change of employment which will take you out into the open air, it is worth your while to consider the matter of learning to be an expert automobile operator and to take up that line of work. The great growth and development of the automobile and its use needs no comment. The compensation of the chauffeur is good and the demand for his services so steady, and the standing of the profession is so high now, that it is more and more attractive to that class of individuals who are able and willing to combine mechanical skill with intellectual effort. It is for that class of men this course is intended and it is that class of men, who, by supplementing their natural mechanical genius with a little properly directed mental work, can qualify themselves to secure well paid positions, such as, to the proper persons, are certain to prove stepping stones to greater advancement. The great number of chauffeurs who enjoy the esteem and confidence of their wealthy employers is well known, and we could enumerate hundreds who have started in business for themselves and who are on the road to wealth through the assistance of their employer. The Object of Our School The object of our School is to prepare young men throughout the country to become expert chauffeurs, repairmen, demonstrators, salesmen, garage managers, etc. Our president, Mr. C. A. Coey, has been in the automobile business for twelve years, and he is one of the most prominent automobile men in America today. During this time he has sold thousands of automobiles, and his customers can be found in every state in the Union. He found that the only way he could supply the demands of the automobile dealers and manufacturers throughout the country, was to open a school of motoring, and it is for this reason that _C. A. COEY'S SCHOOL OF MOTORING_ was started. Mr. Coey commenced as a small farmer boy himself, and he knows that the country boys are even more ambitious than those in the city, but they do not have the opportunities like the city boys. And because he knew that there were plenty of such young men all over the country, who would be able to fill just such positions, if they could but prepare themselves, and at the same time to supply the demand from his customers throughout the country for good honest young men he founded this School. [Illustration] A Word About our President Mr. C. A. Coey Mr. Coey has been prominently identified with the automobile business in Chicago from its inception, in fact, he is the pioneer automobile man of Chicago. He constructed the first building ever erected in America for an automobile garage, which is now standing at the corner of Cottage Grove Avenue and 53rd St., Chicago, Illinois. [Illustration: The first building erected for an Automobile Garage--built by C. A. Coey.] He placed the first taxicabs on the streets of Chicago and now owns the best in the city. [Illustration: The first taxicab seen in Chicago--C. A. Coey, owner.] He is one of the few who made a success of the automobile livery business, beginning with one car and increasing to fifty. Commencing with practically nothing, he built up not only the largest automobile livery business in the country, but also the largest automobile sales business in America. The companies bearing his name now maintain a large garage and salesroom. Mr. Coey is intimately connected with some of the foremost men of this country and is well known as an automobile manufacturer and dealer throughout the country, and a _DIPLOMA_ with his name signed to it is the best thing you can have when looking for any kind of employment in the automobile industry. He has secured more good paying positions for his students and friends than all other auto schools in America combined, because he is so well known. [Illustration: At the left--C. A. Coey, next to him--Charles Bonaparte, grandson of the late Napoleon the Great.] [Illustration: Ex-Vice-President Fairbanks, C. A. Coey, and Judge Hanecy.] [Illustration: C. A. Coey, at the left, and U. S. Senator "Pitchfork" Tillman.] [Illustration: William Hoppe, the world's champion billiardist, in the front seat with C. A. Coey at the wheel.] [Illustration: C. A. Coey at the wheel and Rube Waddell, the famous ball player, by his side.] [Illustration: Packy McFarland, Chicago's star boxer, in one of Mr. Coey's machines.] [Illustration: Charles J. Glidden in his rail riding automobile and C. A. Coey in the rear to the right.] Mr. Coey has won more twenty-four hour races than any other man living and holds the world's record for twenty-four hours for a one-man driver, covering 990 miles without a minute's rest. [Illustration: Start of the 24 hour race at Chicago--won by C. A. Coey.] [Illustration: As seen on the back stretch of the 24 hour race--C. A. Coey passing other contestants.] [Illustration: The Finish--C. A. Coey at the wheel. The Winner.] Mr. Coey has also been widely known throughout the country in connection with ballooning, and he holds the world's speed record, having covered six hundred and seven miles in ten hours and fifty-five minutes, ascending at Quincy, Illinois, on the 2nd day of June, 1907, in the evening and sailing through the clouds all night, through thunder storms, and making a landing at Clear Lake, South Dakota, at five A. M. the next day. [Illustration: C. A. Coey, in balloon costume--ready for a trip to Cloudland.] [Illustration: The next morning on the way to the Railroad Station with Balloon and Basket.] [Illustration: The landing he made in a tree top in Illinois.] On the flight from Chicago on the 4th of July, 1908, at the meeting of the Aeronautique Club of Chicago, of which Mr. Coey was president, he crossed the Great Lake, landing in West Monkton, Canada, covering a distance of five hundred and fifty-six miles, having made the flight in a single night in his balloon, "Chicago," the largest balloon in the World. In this trip he sailed over seventy-five miles of water. [Illustration: The mammoth balloon "Chicago," the largest in the world--owned by C. A. Coey.] [Illustration: Barney Oldfield, Jerry Eller and C. A. Coey in Mr. Coey's racing car.] [Illustration: C. A. Coey's first six cylinder racing car, with which C. A. Coey gave Barney Oldfield close shaves on several occasions.] [Illustration: Mr. Coey's mother and sister watching him fly away.] [Illustration: C. A. Coey up in Cloudland.] [Illustration: Giving the girls who brought him his breakfast a ride.] [Illustration: How the earth looks from one mile high--taken by C. A. Coey.] [Illustration: How the clouds look from above--taken by C. A. Coey.] [Illustration: Bowling Green, Ky., taken by C. A. Coey at an altitude of 10,000 feet.] [Illustration: C. A. Coey after coming to earth for breakfast.] [Illustration: The basket of the Giant Balloon "Chicago" owned by C. A. Coey.] [Illustration: The way Mr. Coey sometimes landed--taken in California.] [Illustration: Barney Oldfield and C. A. Coey going for a balloon ride. Mr. Oldfield's first and last trip.] [Illustration: C. A. Coey and Frank Gotch, winner of first prize in Decorated Car parade.] [Illustration: A few cups won by C. A. Coey.] [Illustration: C. A. Coey's car winner of first prize in Floral parade.] Mr. Coey is President of the following Corporations: COEY-MITCHELL AUTOMOBILE COMPANY, Capital $250,000.00 AMERICAN TRAVELER COEY COMPANY, Capital $100,000.00 C. A. COEY'S SCHOOL OF MOTORING, Capital $50,000.00 And a member of the following clubs: Chicago Automobile Club (_life member_) Illinois Athletic Club (_life member_) South Shore Country Club Chicago Motor Club Chicago Auto Trade Association Chicago Commercial Association Our Correspondence Course For the benefit of those who cannot spare the time to come to our School, we have compiled a correspondence course, in which we will guarantee to teach you how to run, repair and demonstrate any automobile _in ten weeks_. This course consists of ten lessons all written plainly and in such an intelligent manner, that anyone who can read and write can master any automobile. They lead you step by step, on and on until you have reached the end, and then you will be surprised at your own knowledge of an automobile. We send you one lesson at a time, and as soon as you have answered all of the questions contained on the last page of the book correctly, we will send you the next lesson, and so on, until you have received the ten lessons. Some can master two and three a week--it all depends upon the person. We assist backward students by giving more time to them and answering any questions they wish to ask, as we desire above everything else to make every student a first class high grade automobile man, an honor to our School and a help to us and our customers. The cost of our correspondence course is $15.00. If, after you have finished our correspondence course, you wish to learn the manufacture of a motor car, you can come to our factory, and we will give you our practical course at our regular rates and deduct the amount you have paid for the correspondence course. Many who have decided to come to our factory and take our practical course wait until they have finished the correspondence course, where in the quiet of their homes they can get the principles fixed in their minds, and then when they come to our School they are ready for business. Description of the Ten Lessons INTRODUCTION--The method the students should employ in studying our course. LESSON ONE--_The Engine_--automobile engines in general; the four cycle engine, chart and working model of same; parts of an automobile engine, what they are made of and their uses; the two cycle motor and how it differs from others. LESSON TWO--_Cooling systems of Automobiles_--cooling the engine by water; the pump, showing different types; gravity circulation; fans; air cooled motors; causes of troubles and remedies for them; the carburetor, automatic and mechanical, charts of different standard makes. LESSON THREE--_Ignition_--different systems of; different currents used; the storage battery; dry cells; spark plugs; adjustment of spark coils; low and high tension magnetos; different systems of wiring ignition batteries; troubles and their remedies; charts and devices for standard ignition systems. LESSON FOUR--_Transmissions_--different types of, planetary, friction, sliding gear; bearings used on transmissions, how to adjust them; shifting levers and quadrants. LESSON FIVE--_Clutches_--internal and external cone clutch band and drum clutch, expanding ring clutch, multiple disc clutch; clutch coupling devices. LESSON SIX--_Operation_--how to drive a car; hints on saving transmission wear; things to be remembered when starting a car; emergency brake and its use; throttle control. LESSON SEVEN--_Tires_--pneumatic and solid, cause of unnecessary wear; the puncture and how to repair it; pinching innertubes, rim cutting, and prevention for same; how to determine the proper size tire for car. LESSON EIGHT--_Driving_--in the city; rules of the road; car signals. LESSON NINE--_The care of a car_--how to detect troubles and how to prevent and remedy same. LESSON TEN--_Overhauling_--the method used in taking a machine apart and putting same together; things to do and things not to do. Ten Weeks Sufficient There is no reason why one cannot finish our course in the allotted time of ten weeks, but no charge will be made if more time is required, as we desire above everything to give you such a course that your efficiency will make your work a pleasure. Your work can be done as well thousands of miles away as if you were on the ground at our School. If you contemplate purchasing a machine, you could not do better than to first take our course, when you will be able to judge better on your own account precisely what style of machine is peculiarly adapted to your needs and your particular section of the country. We can be of great service to you in choosing a machine. Some machines are better adapted to certain localities than others; for instance, a hilly or sandy country requires a low geared, light weight, high powered machine, and you can rest assured on getting our unbiased opinion. Our course has been taken by many ladies who own or contemplate owning a machine, and they are among those who are most emphatic in praising our method of teaching. [Illustration: Scene of a bull fight taken by C. A. Coey.] Remember It is a nice thing to understand a motor, whether you ever intend to drive one or not. * * * No one should purchase an automobile without first taking our course. * * * The man who buys a motor car without first learning one will live to regret the day. * * * Astonishing, but nevertheless true, not one-half of the machines manufactured are fit to be placed on the market. Do you know the reason why? * * * Never buy a car with the weak point, every other car has it, take our course and be able to select the right one. * * * Motoring is easy and pleasant, if you are its master, but if you are not, you had better stay at home. * * * Whether you spend most of your time under the car or on the car, depends on whether or not you understand it. * * * A thousand things can happen to a motor, any one of which is easily remedied if you know where to begin. * * * A Diploma is valuable when backed by one who is prominent in the automobile world, and with a _COEY DIPLOMA_ at your back, you are independent for life. Our Practical Course There is, perhaps, no place in this wide world where the student can get such thorough training as at our factory. We are the only ones in this country who have a factory where up-to-date automobiles are actually built by students. [Illustration: A few of our students getting actual experience.] [Illustration: Each student works alone--showing the separate apartments.] The average practical automobile school, and we might say every last one of them, instruct their students on old, worn-out, out-of-date machines, which are ready for the junk pile, and what they learn on those old relics will do them no good, in fact, they might better have taken no schooling at all, as such work only tends to confuse and mislead them. For if a person once learns to do a thing the wrong way, he usually keeps on doing it and it is hard to get out of the habit. And that is the reason why our students have been successful in filling fine, easy, and well paying positions, because they are instructed on up-to-date machines in an up-to-date manner. [Illustration: A view of our lecture room.] [Illustration: A corner in our machine shop.] In our factory we teach a student the art of automobile building, and teach him to drive the machine he himself has helped to build. [Illustration: A few of our students out driving in a car they helped to build.] He takes it from the ground up, under the very best trained and skilled mechanics and instructors in America, and when he has finished he can command big wages. [Illustration: One of our cars which students are instructed to operate.] It requires from three to eight weeks to go through our factory, all depending on the aptness of the student. We try to get our students through as quickly as possible, but we will not issue a Diploma until in our estimation he is qualified to fill any position in connection with an automobile. [Illustration: A Chauffeur's picnic with C. A. Coey's colored mascot in the foreground.] Since you have decided to take up the automobile business, the question naturally arises, "Where can I learn it the best? and after I have learned it, which school is in better shape to help me to get a good paying position?" Any school will tell you they will assist you, but what does that mean? It means simply nothing at all because there is nothing behind it. Assistance will do you no good unless you get the position. The President of the United States could give you any kind of a position you could ask for, because he has the influence, so could the Governor of your state--influence is what counts. You stand a far better chance of getting a good paying position through our School--yes, ten to one, better than in any other school in the world. Anyone with ordinary intelligence can write a book on automobile instruction--anyone can run an advertisement in the paper and get replies, and send out glowing literature, and get letters from prominent automobile men and dealers and manufacturers, but when it comes to getting you a position that is where they are weak. [Illustration: A view of Mr. Coey's automobile salesroom, where students get actual experience selling new cars.] [Illustration: C. A. Coey in his private office, the finest on "Automobile Row."] We could name one auto school owner in the middle West and one in the East, who were never in the automobile business, and who do not even now own one. They send out glowing advertisements and secure letters from auto manufacturers and dealers to help them get started, but if you can find where a single person has ever secured a position through these letters or through their influence, excepting a few whom they have paid themselves in order to get some recommendations, we will send you our course free. Do you know that Mr. Coey is the only one of any importance in the automobile world whatsoever who is connected with an automobile school? Do you know that he is the only one who is engaged in handling high grade motor cars? And last but not least, not another person in the world running an automobile school has any connection with an automobile factory. So what does it mean? Just this--that instead of a few ex-chauffeurs or ex-clerks banding together and calling themselves an auto school, we have as our head a _real automobile man_, one with vast interests and prominently connected in many branches of the business, and one who can secure you a position. Send your application in today and commence at once. Yours for success, C. A. COEY'S SCHOOL OF MOTORING, 1424-26 Michigan Avenue. CHICAGO, ILLINOIS, U. S. A. Our Diploma There is no better recommendation for anyone than a Diploma from _C. A. COEY'S SCHOOL OF MOTORING_, which stands the country over for _SUCCESS_. It is one thing to learn the automobile business, but quite another to get profitable employment. Forty diplomas will not help you unless the School is backed by someone well-known in the automobile world. It is not our policy to get your money and then rush you through. We are interested in you from the time you start until long after you have finished. We cannot conduct our business throughout the country without _you_, so _we must train you right_. The thousands of automobiles which Mr. Coey sold during the past ten years all need drivers, and our customers and agents in every territory look to us to keep them supplied. [Illustration: This is the thing that will insure you a job at any time and at any place.] Employment Department This department is maintained for the exclusive use of our students _free of charge_. We supply first class help for positions as: Chauffeurs, Racers, Auto Salesmen, Demonstrators, Garage Managers, Assemblers for factories, And all branches of the automobile business. [Illustration: One of Mr. Coey's drivers on one of his taxicabs, who made $105.55 in one week.] Terms of Tuition While our course is the most complete and thorough, yet our rates have been kept as low as possible. As we figure we might better have students in all walks of life, we have placed the price within reach of all. It is, however, subject to a raise without notice. (For rates see our Application Blank) City Examinations After you have spent your time in an Auto School then comes the city examination, which, if you do not pass, you might as well not have wasted your time. Do you know that over one-half who, after they have secured their diploma, are not able to pass the examinations for a City License? Well, it is true. _But not a single one of OUR students has ever failed to pass the examinations and secure a chauffeur's license._ The City Mechanician of Chicago, Mr. H. L. Hudson, who decides whether or not you are entitled to a license, commenced with Mr. Coey in the automobile business in 1900. He was Mr. Coey's private mechanician on his racing cars. Mr. Hudson is an automobile expert and that is the reason he holds a fine city position. He recently inspected our School, and this is what he said: "I wish to compliment you on the method you employ in your School of Motoring. The many years I spent as mechanician on your private racing cars certainly furnished us both information of a definite character, which is necessary for a man holding such an important position as Automobile School Instructor and Examiner of the Board of Public Motor Vehicle Register of the City of Chicago. You seem to have the proper system and your vast experience with chauffeurs in the ten years past fits you, as no one else is fitted, for a competent instructor. I believe you are on the right track and wish you success. Yours very truly, (Signed) H. L. HUDSON, City Mechanician." The following is what the Chicago Examiner has to say about our School. (This article appeared without our knowledge and shows our standing in the City of Chicago, which assures you of a square deal.) "SCHOOL IS OPENED TO INSTRUCT AUTO DRIVERS." "A motoring school for the purpose of instructing persons in the running of automobiles has just been opened by C. A. Coey. This school will be of national scope and owing to the fact that Chicago is centrally located and the great railroad and mail distributing center, it will enable persons desirous of availing themselves of the benefits of institutions of this sort, to be in direct communication with instructors. Mr. Coey is nationally recognized as one of America's pioneer motorists and he realizes, as do the manufacturers, that the failure of so many automobiles to perform their proper functions and the occurrence of so great a number of accidents are due to the inefficiency of persons handling them." A clipping from the Chicago Journal reads as follows: "Charles A. Coey is one of the pioneer automobile men of Chicago. He entered the business in 1900 and conducted a motor livery until 1902, when he became Chicago agent for the Thomas Flyer. He handled the Thomas line from 1902 until 1909, when he gave up the selling end to devote all his attention to his taxicab business. Last year he became Chicago agent for the American car, which he is handling under a ten-year contract. He is president of a company which is manufacturing the Coey Flyer in Chicago. Mr. Coey is well-known as an automobile racing driver and aeronaut. He won the Chicago Automobile Club's twenty-four-hour race at Harlem several years ago. He has made many long-distance flights in balloons." And the Live Stock Magazine has this to say: "Perhaps the oldest and most prominent person in the automobile business in Chicago is C. A. Coey, the pioneer automobile dealer. Mr. Coey started an automobile school in 1901 at 5311 Cottage Grove Ave., Chicago, and it was there that the first building ever erected for an Automobile Livery was built. While Mr. Coey did not at that time advertise his School of Motoring, yet he started on an extensive business in this line, and it was said that over one thousand are now holding good, steady, well-paying jobs, and drawing salaries up to $75 a week. Mr. Coey's system is different from the rest, as he believes that a student can learn the foundation principles in the quiet of his home, and then after he has mastered the principles he is given a practical road course. We recommend this School as a reliable institution." How to get an Automobile Absolutely Free As we told you in another part of this book--_WE ARE BUILDING AUTOMOBILES_--a machine of the highest quality and the very latest design, the specifications of which can be found on the last page of this book. _AGENTS WANTED_ We desire agents in every county in the United States and to those who take our course, either the correspondence or the practical course, we make this offer: First, as soon as you have commenced to take our course we give you the right to sell the _COEY FLYER_, and for every one you sell, we will send you $200.00 in gold, and then after you have sold ten machines, we will send you one _ABSOLUTELY FREE_, and prepay the freight on same to any part of the United States, so that it is delivered to you free from all cost. We will extend this offer to no one who has not taken a course in our School of Motoring, for we know that after you have taken this course, you are capable of operating _ANY MACHINE_ without any trouble, and it will be an advertisement for our School as well as for our machine. _EVERY STUDENT MADE AN AGENT_ Second, as soon as you have commenced to take our course, we will send you a quantity of circulars and a large poster which you can hang in some conspicuous place, with your name in bold type at the bottom, showing you as our agent. _NOW GET BUSY!_ The Automobile business has come to stay and there will be many machines sold in the next few months to people that you already know, and if you let them know that you are our agent, they will be glad to buy from you, as they will readily see that you can be of great help to them when they commence to learn to run their machine, and they can buy from you as cheaply as if they had come to Chicago and bought direct from us. We would suggest that in order to get a Coey Flyer in your locality at once, that you go to someone whom you know is going to buy a machine and tell him that if he will allow you to use his automobile occasionally you will give him your commission, and if he knows that he can save $200, he will be glad to do it. [Illustration: Three-quarter view of the Coey Flyer.] [Illustration: Rear view of the Coey Flyer.] [Illustration: Front view of the Coey Flyer.] This is the grandest offer ever made by anyone, and those who take advantage of it will thank us a thousand times. Just think--a chance to get rich for only $15.00. Have you ever had such an offer? Specifications of the Coey Flyer _Motor_--Bore, 4-inch; Stroke, 5-inch; Cylinders, 6; T-Head, grouped in triplets; Crank Shaft, 2 inch; 3 large bearings. _Valves_--Opposite sides. _Oiling_--Mechanical pump. _Cooling_--Water--force pump. _Radiator_--Honeycomb. _Fan_--Driven by belt. _Ignition_--High tension. Bosch. _Control_--Hand and Foot. _Carbureter_--Schebler Model L. _Fuel Feed_--Pressure from exhaust. _Clutch_--39 disc--polished saw metal. _Transmission_--Three speed forward, one reverse; Selective, on rear axle. _Ratio_--Three and one-fifth to one. _Rear Axle_--Semi-floating (The Stutz). We use the axle designed for a 7-passenger car. _Starter_--We furnish Presto Self Starter for $25 extra. _Depth of Rear Cushion_--20 inches. _Width of Rear Cushion_--43 inches. _Distance from Back of Front Seat to Rack of Rear Seat_--48 inches. _Front Axle_--I-Beam. _Wheel Base_--124 inches. _Tread_--56 inches. _Tires_--36x4 all around. _Rims_--Quick demountable; Baker bolted on. _Springs_--Front, semi-elliptic, 41 inches long. _Springs_--Rear, three-quarter elliptic, 40 inches long. _Brakes_--Foot and Emergency; both internal expanding. Diameter of drum, 14 inches; width, 4½ inches. _Frame_--Chrome nickel steel, 4-inch Kickup. _Equipment_--Top, Front Glass, Curtains, 5 Lamps, Prest-o-lite Tank, Tools, Jack, Pump. _Weight_--2,730 pounds (with tanks empty). _Speed_--2 to 68 on high gear. _Colors_--Bottle Green, Golden Brown, Coey White. Other colors no extra charge, but a delay of 30 days may be necessary. Now, in conclusion, Mr. Reader--above all, do not hesitate but start _today_. If not with us, then with some other School, for with them you can learn something about this mammoth rapid-growing, health-giving business. Now is the time to act--send us your application today. Yours for success, C. A. COEY'S SCHOOL OF MOTORING, 1424-26 Michigan Avenue. CHICAGO, ILLINOIS, U. S. A. HAMMOND PRESS W. B. CONKEY COMPANY CHICAGO * * * * * Transcriber's Notes: Italic text is denoted by _underscores_. Obvious printing mistakes have been corrected. Page 24, "recommnedations" changed to "recommendations." 
41217	----	Transcriber's Note: Bold text is denoted by =equal signs=. A more detailed note is located at the end of this book. Note de transcription: Le texte en gras est entouré par =le signe égal=. Une note plus détaillée se trouve à la fin du volume. ENGLISH-FRENCH AND FRENCH-ENGLISH DICTIONARY OF THE MOTOR CAR, CYCLE AND BOAT ENGLISH-FRENCH AND FRENCH-ENGLISH DICTIONARY OF THE MOTOR CAR, CYCLE, AND BOAT BY FREDERICK LUCAS NEW IMPRESSION [Illustration: Printer's logo] London E. & F. N. SPON, LIMITED, 67 HAYMARKET New York SPON & CHAMBERLAIN, 123 LIBERTY STREET 1915 ALL RIGHTS RESERVED PREFACE The object of this work is to assist those interested in the motor industry and pastime to read the foreign technical literature devoted to the subject. I have translated into the respective languages the technical terms used in the various journals and the catalogues of the leading English and French makers. The work embodies all the component parts of the vehicles and machinery at present on the market, and should therefore be of service to the user, the manufacturer, and the patent agent. The technical terms which are peculiar to cycles are printed in italics. FREDERICK LUCAS. 9 GRACECHURCH STREET, LONDON, E.C. CONTENTS PAGE ENGLISH-FRENCH 1 FRENCH-ENGLISH 95 DICTIONARY OF THE MOTOR CAR, CYCLE, AND BOAT. ENGLISH-FRENCH. Accelerator Accélérateur. Accelerator control gear Mouvement de commande d'accélérateur. Accelerator pedal Pédale d'accélérateur. Accelerator rod Tige d'accélérateur. Accelerator rod spring Ressort de tige d'accélérateur. Accelerator rod washer Rondelle de tige d'accélérateur. Accelerator sector, or quadrant Secteur d'accélérateur. Accelerator shaft Arbre d'accélérateur. Accessories Accessoires. Accident Accident. Accumulator Accumulateur. Accumulator cap Bouchon d'accumulateur. Acetylene gas Gaz acétylène. Acetylene lamp Lanterne à acétylène. Acetylite Acétylite. Active material Matière active. Adhesion Adhésion. Adjust the ball-bearings, to Ajuster les roulements à billes. Adjustable bearings Coussinets ajustables. Adjustable cone bearings Coussinets à cônes réglables. Adjustable cup bearings Coussinets à cuvettes réglables. Adjustable seat Siège ajustable. Adjusting cone Cône de réglage. Adjusting nut Ecrou de réglage. Adjustment Réglage. Advance, sparking Avance à l'allumage. Air chamber Chambre à air. Air chimney Tube de prise d'air; cheminée d'aspiration. Air inlet pipe Tube de prise d'air. Air lever Manette d'admission d'air. Air nozzle for carburetter Tuyère de carburateur. Air piston Piston à air. Air port Prise d'air. Air pump Pompe à air. Air tight Etanche à l'air. Air tube Chambre à air. Air valve Soupape à air. Alcohol Alcool. Alight, to Descendre. Aluminium Aluminium. Amateur Amateur. Ammeter Ampèremètre. Amperage Ampérage. Ampere Ampère. Angle bar Cornière. Angle plate Equerre. Anneal, to Recuire. Apply the brake, to Freiner; serrer le frein. Apron Tablier. Arbor shaft Cardan. Arbor shaft system of Transmission à Cardan. transmission. Arm sling Brassière. Armature Induit. Artillery wheel Roue d'artillerie. Ascent, steep Montée rapide. Asbestos Amiante. Asbestos cloth Toile d'amiante. Asbestos cord Corde d'amiante. Asbestos millboard Carton d'amiante. Asbestos paper Papier d'amiante. Asbestos washer Rondelle d'amiante. Ash Frêne. Automatic Automatique. Axle Essieu; axe. Axle arm Fusée d'essieu. Axle box Boîte à graisse. Axle seat Portée de calage. B Back balance, crank Contrepoids de vilebrequin. _Backbone_ _Corps._ Back fire Allumage prématuré; choc en arrière. _Back fork_ _Fourche arrière._ _Back fork stays_ _Tirants de la fourche arrière._ _Back forks, end of_ _Pattes arrière._ Back hub Moyeu arrière. _Back hub adjusting cone_ _Cône de réglage du moyeu arrière._ _Back hub chain ring_ _Pignon de roue arrière._ _Back hub fixed cone_ _Cône fixe du moyeu arrière._ Back kick Choc en arrière. Back mudguard Garde-boue arrière. _Back mudguard stays_ _Tirants du garde-boue arrière._ _Back pedal, to_ _Contre-pédaler._ _Back-pedalling brake_ _Frein à contre-pédalage._ Back pressure Contre-pression. Back rim Jante de la roue arrière. _Back stay_ _Tube montant arrière._ Back step Marchepied d'arrière. Back tyre { Bandage de la roue arrière. { Pneumatique de la roue arrière. Back wheel Roue arrière. _Back wheel spindle nuts_ _Ecrous de moyeu arrière._ Back wing Aile d'arrière. Badge Insigne. Baffle plate Contre-plaque. Baffles, arranged as En chicanes. Bag Sac. Balance gear Mouvement différentiel. Balance weight Contre-poids. Ball Bille. Ball bearing axle Essieu à billes. Ball bearing axle arm nut Ecrou d'essieu à billes. Ball bearing axle washer Rondelle d'essieu à billes. Ball bearing thrust Butée à billes. Ball bearings Coussinets à billes. Ball for axle arm Bille pour fusée d'essieu. Ball for carburetter Bille pour carburateur. Ball for oil pump Bille pour pompe à huile. Ball, governor Boule de régulateur. _Ball head_ _Tête à billes._ Ball joint Joint à rotule. Ball lever Levier à boule. Ball race Rangée de billes. Ball race cup Cuvette à billes. Ball race of back axle Cuvette arrière d'essieu à billes. Ball race of front axle Cuvette avant d'essieu à billes. Ball valve Soupape à bille. Band Collier; bande. Band brake Frein à bande; frein à collier; frein à enroulement. Bank up the corners of the track, Relever les virages de la piste. to Ball bearing axle Essieu à billes. Bar of iron Barre de fer. Base Socle; base. Battery Batterie. Beaded edge of tyre cover Talon; bourrelet. Beam Traverse; poutrelle. Beam (breadth of boat) Largeur au maître-bau. Bearing Coussinet. Bearing block Palier. Bearing keep Chapeau de palier. Bearing spring Ressort de suspension. Beech Hêtre. Bell Timbre; grelot; sonnette; clochette. Bell crank Manivelle à cloche. Bell, dome of Calotte de timbre. Belt Courroie. Belt butt Crupon pour courroie. Belt, cemented Courroie collée. Belt, edged Courroie à talon. Belt fastener Agrafe de courroie. Belt, flat Courroie plate. Belt grease Enduit pour courroies. Belt lace Lacet; lanière. Belt, round Courroie ronde. Belt, sewn Courroie cousue. Belt, slack Courroie lâche. Belt, slipping of Glissement de la courroie. Belt, stretching of Allongement de la courroie. Belt, tight Courroie tendue. Belt tightener Tendeur pour courroie. Belt, to lengthen the Allonger la courroie. Belt, to shorten the Raccourcir la courroie. Belt, to throw off the Débrayer la courroie. Belt, to tighten the Tendre la courroie. Belt, to untwist the Détordre la courroie. Belt, twist Courroie torse. Belt, twisted Courroie tordue. Belt, V Courroie en V. Bending strain Effort de flexion. _Bent handle bar_ _Guidon cintré._ Bevel gear Engrenage conique. Bevel pinion Pignon d'angle. Bevel wheel Roue d'angle. Bevelled Biseauté. _Bicycle_ _Bicyclette._ _Bicyclist_ _Bicycliste._ Billing spanner Clef américaine à molette "Billing." _Bike_ _Bécane._ Birchwood Bouleau. Blacklead Mine de plomb. Blacksmith Forgeron. Blade (coil) Lame de bobine. _Blades, fork_ _Fourreaux de fourche._ Bleriot lamp Phare Blériot. Blind flange Bride borgne. Blind nut Ecrou borgne. Block Bloc; cale; sabot. Block chain Chaîne à blocs. Blowpipe Chalumeau. Blow through tap Robinet de purge. Body Caisse. Body spring Ressort d'essieu. Boil (on cover) Hernie; gerçure. Boiler Chaudière. Boiler, flash Générateur à vaporisation instantanée. Bolt Boulon. Bolt (of door) Verrou. Bolt and nut Boulon et écrou. Bonnet Entourage; capot couvre-moteur. Bonnet door Porte d'entourage. Bore Alésage. Boss Moyeu. _Bottom bracket_ _Pédalier._ _Bottom head cone_ _Cône du raccord inférieur avant._ _Bottom head cup_ _Raccord inférieur avant._ _Bottom stay_ _Tube de la fourche arrière._ _Bottom tube_ _Tube inférieur._ Bowden wire Câble flexible Bowden. Box Boîte. Box spanner Clef à douille. Box-wood Buis. Bracket, lamp Porte-lanterne. Bracket seat Strapontin. Brad Clou à parquet. Bradawl Poinçon. Braid Tresse. Brake Frein. _Brake adjusting clip_ _Collier de tube de frein._ Brake band Collier de frein; bande de frein. _Brake detachable clip_ _Collier de levier de frein._ Brake guide Guide de frein. Brake holder Serre-frein. Brake horse-power Force en chevaux effectifs; puissance au frein. Brakeless Sans frein. Brake lever Levier de frein. Brake lever connecting rod Bielle de levier de frein. Brake lever catch Cliquet du levier de frein. Brake lever handle spring Ressort du cliquet de levier de frein. Brake pedal spring Ressort de rappel de pédale de frein. _Brake plunger_ _Tube de frein._ Brake pulley Poulie de frein. Brake rod Tige de frein. Brake rod end Chape de tige de frein. Brake rod fork Fourchette de tige de frein. Brake screw Boulon, vis de frein; vis de mécanique. Brake segment Segment de frein. Brake spoon, or shoe Patin, sabot de frein. Brake spring Ressort de frein. Brake, to apply the Serrer le frein. Brake tube Tube de frein. Brake and clutch lever connecting Bielle de commande de débrayage rod et de frein. Brass Cuivre jaune; laiton. Braze, to Braser. Breadth Largeur. Break-down Panne. Break down, to Rester en panne. Breaking strain Charge de rupture. Bridge Pont. _Bridge, back fork_ _Tirant de la fourche arrière._ Bridge piece Culotte. Bridge piece for exhaust Culotte d'échappement. Bridge piece for inlet valve Culotte d'aspiration. Bright parts Parties polies. Broad Large. Brougham Coupé. Brush, dynamo Balai. Bucket seat Baquet. Buckled wheel Roue voilée; roue tordue. Buffer Tampon. Buffer guide Boisseau de butoir. Buffer head Tête de butoir. Buffer spring Ressort de choc. Bulb (glass) for accumulator cap Ampoule verre pour bouchon d'accumulateur. Bulge (on cover) Hernie; gerçure. Bulb of horn Poire de cornette. Bulk, in En vrac. Bumpy road Route cahotante. Burn well, to Brûler bien. Burner Brûleur. Burner cage Lanterne. Burner case Monture des brûleurs. Burner cup Cuvette de brûleur. Burner for acetylene lamp Bec. Burner guard, or hood Capuchon de brûleur. Burner mount Monture de brûleur. Burner needle Aiguille pour brûleur. Burner nipple Bec de brûleur. Burner tank Lampe. Burst, to Eclater; crever. Burst (tyre) Crevaison. Bush Douille; bague. Bushed Fourré; garni. Butt-ended spokes Rayons renforcés. Butterfly nut Ecrou à oreilles; papillon. Butterfly valve Soupape à papillon; papillon. Button Bouton. Butt-welded Soudé par rapprochement. C Cab Cab. Cam Came. Cam, ignition Came d'allumage. Cam shaft Arbre à cames. Cam shaft cover Couvercle d'arbre à cames. Cam shaft roller Galet d'arbre à cames. Camel hair belt Courroie poil de chameau. Candle Bougie. Candle lamp Lanterne à bougie. Canopy, removable Ballon démontable; couvercle démontable. Canvas Toile. Canvas for repairing cover Toile dissolutionnée; toile gommée. Cap Chapeau; bouchon. Cap for oil hole Bouche-trou. Cap for steering connecting rod Bouchon de bielle de commande de direction. Cap for water tank Bouchon d'emplissage de réservoir d'eau. Cap of draw link Chapeau de tension. Capacity (of tank) Contenance. Car Voiture. Car wheel Roue de voiture. Carbide Carbure de calcium. Carburetter Carburateur. Carburetter connecting rod Bielle de commande de carburateur. Carburetter float Flotteur de carburateur. Carburetter float cap Bouchon de dessus de carburateur. Carburetter float needle Aiguille de carburateur. Carburetter float spindle Axe de flotteur de carburateur. Carburetter hand regulator Régulateur à main de carburateur. Carburetter lever spring Ressort de rappel de levier de carburateur. Carburetter nipple Bec de carburateur. Carburetter piston Piston de carburateur. Carburetter piston rod end Chape de piston de carburateur. Carburetter piston spring Ressort de piston de carburateur. Carburetter valve Soupape de carburateur. Carburetter valve spring Ressort de la soupape de carburateur. Cardan Cardan. Cardan joint Joint Cardan. Carpet Tapis. Carriage builder Carrossier. Carriage clock Horloge de voiture. Carriage road Route carrossable. Carriage work Carrosserie. Carrier, luggage Porte-bagage. _Carrier tricycle_ _Tricycle porteur._ Carrying axle Essieu porteur. Carter gear case Carter. Carvel built A franc bord. Case Gaine; caisse. Cased Blindé. Case harden, to Cémenter. Casing Blindage. Cash prizes Prix en espèces. Cast iron Fonte. Cast steel Acier fondu. Castor oil Huile de ricin. Catalytic Catalytique. Catalysis Catalyse. Catch Cliquet; verrou. Catch for bonnet door Verrou d'entourage. Catch for change speed lever Verrou de levier de changement de vitesse. Caulk, to Calfater. Cedar Cèdre. Cell Elément. Celluloid Celluloïd. Cement (for tyres) Colle; mastic. Centaur cylinder Cylindre-culasse. Centering gauge Trusquin à centrer. Centering ring Bague de centrage. _Central driving tricycle_ _Tricycle à chaîne centrale._ Centre to centre D'axe en axe. Centre bearing Palier central. Centrifugal pump Pompe centrifuge; pompe turbine. Chain Chaîne. Chain adjustment Tension de chaîne. Chain adjusting rod; long end; Bielle de tension de chaîne; small end grand côté; petit côté. Chain, block Chaîne à blocs. Chain block Bloc de chaîne. Chain bolt and nut Boulon et écrou de chaîne. Chain brush Brosse à chaîne. Chain, double roller Chaîne à doubles rouleaux. Chain guard Garde-chaîne; couvre-chaîne. Chain link Maillon. _Chain ring lock nut_ _Contre-écrou du pignon arrière._ _Chain ring, back hub_ _Pignon de la roue arrière._ Chain, roller Chaîne à rouleaux. Chain roller Rouleau de chaîne. Chain, single roller Chaîne à simples rouleaux. _Chain wheel_ _Grand pignon._ Chain wheel Roue de chaîne. Chamois leather Peau de chamois. Champion Champion. Championship Championnat. Change speed connecting rod Bielle de changement de vitesse. Change speed gear Changement de vitesse. Change speed lever Levier de changement de vitesse. Change speed lever catch Cliquet du levier de changement de vitesse. Change speed lever catch fork Chape du cliquet de levier de changement de vitesse. Change speed lever rod Tige de levier de changement de vitesse. Change speed lever spring Ressort de levier de changement de vitesse. Change speed rod Tringle de changement de vitesse. Change speed shaft Arbre de changement de vitesse. Channel iron Fer en U. Charge, to Charger. Chassis Châssis. Check valve Soupape de retenue. Checker (in a race) Pointeur. Cheek Flasque. Chestnut Châtaigner. Chinese lantern Lampion; lanterne vénitienne. Chrome leather Cuir chrome. Chronometer Chronomètre. Circuit Circuit. Circuit, primary Circuit primaire. Circuit, secondary Circuit secondaire. Circuit, short Court circuit. Circuit, to close a Fermer un circuit. Circulation pump Pompe de circulation. Clamp Bride; pièce d'attache; presse patte. Clamp for fastening motor Pièce d'attache du moteur. Clasp brake Frein à mâchoires. Clean Propre. Clean, to Nettoyer. Clear, in the Dans l'oeuvre. Clearance Jeu. Clinch of the rim Crochets de la jante. Clincher built A clin. Clip Collier de serrage. Clip brake Frein à mâchoires. Clip for spring Bride de ressort. Close the circuit, to Fermer le circuit. Closure tyres Caoutchoucs auto-réparables. Cloth for cleaning Torchon. Club Cercle; société; club. Club costume Costume social. _Club, cycling_ _Société vélocipédique._ Club run Sortie officielle. Clutch Embrayage. Clutch cone Cône d'embrayage. Clutch cone spring Ressort de cône d'embrayage. Clutch fork Fourchette de débrayage. Clutch lever Levier d'embrayage; yatagan. Clutch lever pedal Pédale à levier de débrayage. Clutch lever roller Galet de débrayage. Clutch shaft Arbre d'embrayage. Clutch shaft spring Ressort d'arbre d'embrayage. Clutch sleeve Manchon. Clutch spring Ressort d'embrayage. Coach, house Remise. Cobble stones Pavé. Coefficient of friction Coefficient de friction. Coil Bobine; serpentin. Coil, electric Bobine électrique. Cog Dent; denture. Cog wheel Roue dentée; pignon. Cog wheel, larger Grand pignon. Cog wheel, smaller Petit pignon. Collapse, to (of tyres) S'affaisser; crever. Collar Bague. Collar for digger Bague de biellette de rappel de tige. Collision Collision. Colour Couleur. Combustion chamber Chambre de combustion; chambre d'explosion. Come off, to Se détacher. Commutator Distributeur d'allumage; distributeur de courant; collecteur. Commutator brush Balai de distributeur d'allumage. Commutator brush spring Ressort de balai de distributeur. Commutator bush Bague pour corps de distributeur d'allumage. Commutator cam shaft Axe portant la came de distributeur d'allumage. Commutator glass Glace de couvercle de distributeur d'allumage. Compass Boussole. Compensating spring Ressort compensateur. Compression relief Décompression. Compression relief lever Manette de commande; manette de compression; décompresseur. Compression stroke Temps de compression. Compression tap Robinet de compression. Compression valve Soupape de compression. Compression valve spring Ressort de soupape de compression. Concealed hinge Charnière avec cache-fente. Condenser Condenseur. Conductor Conducteur. Cone Cône. Cone bearings Coussinets à cônes. Cone clutch Embrayage à cônes. Connecting plug Interrupteur à cheville. Connecting rod Bielle. Connecting rod end Tête de bielle. Consolation race Course de consolation. Constant level carburetter Carburateur à niveau constant. Contact Contact. Contact breaker Trembleur; allumeur; rupteur. Contact breaker spring Ressort de trembleur. Contact screw Vis de contact. Containing case Bac. Contour map Carte avec profils. Control Commande. Controlling lever Manette de commande. Controlling wheel Roue de commande de marche. Convex Bombé. Cool, to Rafraîchir; refroidir. Cooler Refroidisseur. Cooler, beehive Refroidisseur nid d'abeilles. Cooling Refroidissement. Cooling flanges Ailettes. Cooling surface Surface de refroidissement. Copper Cuivre rouge. Copper plated Cuivré. Copper wire Fil de cuivre. Cord Corde; cordon. Core, iron Noyau de fer. Cork float Flotteur en liége; macaron. Cork handle Poignée en liége. Corner Coin. Corner plate Gousset. Cost of the trip Frais de voyage. Cotter Clavette. Cotton waste Déchets de coton. Countershaft Arbre intermédiaire. Countersunk head Tête fraisée; tête noyée. Counterweight Contre-poids. Cover (lid) Couvercle. Cover (tyre) Enveloppe; bandage. Cover for oil hole Bouche-trou. Cover 80 miles in a day, to Couvrir 80 milles dans la journée. Cover of contact breaker Couvercle d'allumage. Covers wired on Pneumatiques à tringles. Covers with beaded edges Pneumatiques à talon. Cow hide Peau de vache. _Crack rider_ _Coureur de première force._ Crank Manivelle; vilebrequin. _Crank bracket_ _Pédalier._ _Crank bracket adjusting collar_ _Collier de réglage des cuvettes de pédalier._ _Crank bracket axle_ _Axe du pédalier._ _Crank bracket barrel_ _Cuvette de pédalier._ Chain bolt and nut Boulon et écrou de chaîne. _Crank bracket cotter pin_ _Clavette de pédalier._ Crank case Carter; bâti de moteur. Crank case lubricator Graisseur de bâti. Crank cotter Clavette de manivelle. Crank disc Plateau de manivelle. Crank, left Manivelle gauche. Crank lever Levier coudé. Crank pin Bouton de manivelle. Crank, right Manivelle droite. Crank shaft Vilebrequin; arbre à manivelle. Crank starting handle Manivelle de mise en marche. Crank washer and nut Rondelle et écrou de manivelle. Crate Caisse à claire-voie. Crate, folding Caisse pliante. _Cross frame_ _Cadre en croix._ Cross head Crosse. Cross section Coupe transversale. Cross shaft Croisillon. Crossways Carrefour. _Crown, front fork_ _Couronne de fourche._ _Cup, bottom head_ _Raccord inférieur avant._ Cup (of bearings) Cuvette. _Cup, top head_ _Raccord supérieur avant._ Cup valve Soupape en champignon renversé. Current Courant. Current, high tension Courant de haute tension. Current, low tension Courant de basse tension. Current, strength of Force du courant. Curtain Rideau. Curve Courbe. Curved frame Châssis cintré. Cushioned seat Siège à coussins. Custom house Douane. Custom house officer Douanier. Customs pass Passavant. Customs receipt Quittance douanière. Customs seal Plomb de la douane. Customs ticket Carte de douane. Cut off valve Soupape de détente. Cut out Coupe-circuit. _Cycle_ _Velocipède_; _vélo_. _Cycle, to_ _Monter à vélo._ _Cycling_ _Velocipédie._ _Cyclist_ _Vélocipédiste_; _cycliste_. _Cyclometer_ _Compteur_; _cyclomètre_. Cylinder Cylindre. Cylinder full (of mixture) Cylindrée. Cylinder head Culasse. Cylinder head cover Couvercle de culasse. Cylinder head stay end Chape de tige entretoise de culasse. D D shackle Menotte. D valve Tiroir à coquille. Damage Dommage. Damage, to Endommager. Danger board Poteau avertisseur. Dangerous hill Descente dangereuse. Dash board Planche pare-crotte. Day's stage Etape journalière. Dead centre Point mort. De-clutch, to Débrayer. Deflate, to Dégonfler. Delivery pipe Tuyau de refoulement. Densimeter Densimètre. Design, to Etudier. Detachable Démontable; détachable. Detachable crank Manivelle détachable. Detailed plan Plan de détail. Detour Détour. Devil Béquille. Diagonal Diagonal, -e. Diagonal tube Tube diagonal. Diagram Diagramme; schéma. Diagrammatic arrangement Disposition schématique. Diameter Diamètre. Diaphragm Diaphragme. Diaphragm piston Piston à air. Diaphragm spring Ressort de piston à air. Differential brake Frein de différentiel. Differential brake bolt Axe du levier de frein de différentiel. Differential brake lever end Chape de frein de différentiel. Differential brake pedal Pédale de frein de différentiel. Differential brake segment Segment de frein de différentiel. Differential brake spring Ressort de rappel de frein de différentiel. Differential gear Mouvement différentiel. Differential gear box Boîte de différentiel. Diffuser Diffuseur. Digger fork Fourchette de rappel de tige. Digger rod Tige de rappel; culbuteur. Digger spring Ressort de rappel de tige. Direct drive on top speed Grande vitesse en prise directe. Direct spokes Rayons directs. Disc Disque. Discharge, to Décharger. Disengage, to Débrayer. Disengaging lever Levier de débrayage. Dish, to Emboutir. Dismantling Démontage. Dismount, to Descendre. Distance Distance. Distance between axles Ecartement des essieux. Distance run Distance parcourue. Distance, to Distancer. Distributor Distributeur. Divided axle Essieu brisé. Dog clutch Embrayage à griffes; manchon à griffes. Dome of bell Calotte de timbre. Door Porte; portière. Door handle Bouton de porte. Door lock Loqueteau de portière; serrure de portière. Door pillar Montant de porte. Dotted line Ligne pointillée. Double ball bearings Coussinets à double filet. Double branch spanner Clef à deux branches. Double butted spokes Rayons renforcés aux deux bouts. Double driving gear Mouvement différentiel. Double ended spanner Clef double. Double helical gear Engrenage à chevrons. Double male screwed Filetage double mâle. Double roller chain Chaîne à doubles rouleaux. _Down tube_ _Tube diagonal._ Dragon tongue Dard. Drain tap Robinet de vidange. Draught Courant d'air. Draught of water when empty Tirant d'eau à vide. Draught of water when loaded Tirant d'eau en charge. _Drawlink (chain)_ _Tension de chaîne._ _Drawlink cap_ _Chapeau de tension._ Dray Camion. _Dress guard_ _Garde-chaîne_; _garde-jupe_. Dressing room Vestiaire. Drill Foret. Drill a hole, to Faire un trou. Drip feed lubricator Graisseur compte-gouttes. Drip tap Purgeur continu. Drive, to Faire marcher. Driver Chauffeur; conducteur. Driving axle Essieu moteur. Driving power Force motrice. Driving pulley Poulie de transmission; poulie motrice. _Driving shaft_ _Axe de volant_; _axe moteur_. Driving shaft Arbre moteur. Driving wheel Roue motrice. Drop counter Compte-gouttes. Drop shackle Huit. Drum Tambour. Drum brake Frein à tambour. Dry battery Pile sèche. Dust Poussière. Dust cap tube Tube pare-poussière. Dust guard Pare-poussière. Dust proof Etanche à la poussière. Dust-shield, gauze Grille métallique; grille anti-poussière. Duty free Exempt de douane; en franchise. Duty, to pay Payer les droits d'entrée. Dynamo Dynamo. Dynamo brush Balai de dynamo. Dynamo wheel Volant de dynamo. E Easy gradient Pente faible. Easy running Très roulant. Ebonite Ebonite. Ebony Ebène. Eccentric Excentrique. Eccentric rod Tige d'excentrique. Eccentric sheave Disque d'excentrique. Eccentric strap Collier d'excentrique. Efficiency of motor Rendement du moteur. Elbow Coude. Electric Electrique. Electric coil Bobine électrique. Electric ignition Allumage électrique. Electric wire Fil électrique. Elliptic spring Ressort elliptique; ressort à pincette. Elm Orme. Elm, grey Orme blanc. Elm, rock Orme noir. Emery cloth Toile d'émeri. Emery paper Papier d'émeri. Enamel Email. Enamel, to Emailler. Enamelled plate Plaque émaillée. End elevation Elévation de bout. End of back forks Pattes arrière. Endless Belt Courroie sans fin. Endurance Endurance; fond. Engine Moteur. Engine shaft Arbre de moteur. Entrance fee Droit d'entrée. Entrance for a race Inscription pour une course. Erratic steering Direction erratique. Exhaust Echappement. Exhaust box Réservoir d'échappement; pot d'échappement. Exhaust fork Fourchette d'échappement. Exhaust fork guide Guide de fourchette d'échappement. Exhaust fork roller Galet de fourchette d'échappement. Exhaust fork roller bolt Axe de fourchette porte-galet d'échappement. Exhaust fork roller spring Ressort de fourchette porte-galet d'échappement. Exhaust gas Gaz de la décharge; gaz brûlé; gaz d'échappement. Exhaust lift cam Came d'échappement. Exhaust pipe Tube d'échappement. Exhaust port Lumière d'échappement. Exhaust pot Pot d'échappement. Exhaust steam Vapeur de décharge. Exhaust stroke Temps d'échappement. Exhaust tubing Tuyauterie d'échappement. Exhaust valve Soupape d'échappement. Exhaust valve cap Bouchon de soupape d'échappement. Exhaust valve flange Bride d'échappement. Exhaust valve fork Fourchette d'échappement. Exhaust valve guide Guide de soupape d'échappement. Exhaust valve lift Taquet de soulèvement de soupape d'échappement. Exhaust valve lift rod Tige de soulèvement d'échappement. Exhaust valve spring Ressort de soupape d'échappement. Exhaust valve stem Tige de soupape d'échappement. Exhibition Exposition. Exhibitor Exposant. Expanding pulley Poulie extensible. Expansion brake Frein à expansion. Expansion of steam Détente de vapeur. Expired, the patent has Le brevet est dans le domaine public. Explosion Explosion. Explosion chamber Chambre d'explosion. Explosion stroke Temps d'explosion. Explosive mixture Mélange tonnant. Extinguisher Extincteur. Extra nuts Ecrous de rechange. Extra price Plus-value. Extra strong tube Tube renforcé. Eye bolt Piton. F Fabric (of tyre cover) Toile. Face of slide valve Glace du tiroir. Faced in the lathe Dressé au tour. Fall, to Tomber. Fan Ventilateur. Fast Rapide. Fasten, to Attacher. Fastener for bonnet Fermeture d'entourage. Fat spark Etincelle chaude. Feat Exploit. Feat of skill Tour d'adresse. Feat of strength Tour de force. Feather Clavette. Feed Alimentation; débit. Feed heater Réchauffeur. Feed pipe Tube d'alimentation. Female cone Cône femelle. Ferrule Frette; virole. Ferry Bac. Ferry, to cross the Passer le bac. Fibre Fibre. Fibre cam Came fibre. Fibre, insulation Fibre isolante. File Lime. File, to Limer. Fillet Congé. Filter Filtre. Finger post Poteau indicateur. Fir Sapin. Fire tube Carneau. Firing nipple Bouchon d'inflammateur. Fitting Montage; agencement. Fixed cone Cône fixe. Fixed seat Siège fixe. Flame guard Pare-flamme; capuchon de lanterne. Flange Bride; collerette. Flanged collar Bague à collerette. Flanged shaft Arbre à plateaux. Flap door Trappe. Flap valve Clapet. Flash boiler Générateur à vaporisation instantanée. Flask Flacon. Flat, on the En palier. Flexible wire Câble flexible. Float Flotteur. Float chamber Boîte du flotteur; réservoir à flotteur. Float wire Tige de flotteur. Flooder Déversoir. Flush head Tête affleurée. Fluted rubber pedal Pédale à caoutchouc cannelé. Flying start Départ lancé. Fly wheel Volant. Foil Clinquant. Fold, to Plier. _Folding bicycle_ _Bicyclette pliante._ Folding seat Strapontin. _Folding tricycle_ _Tricycle compressible._ Foot Pied. Footpath Sentier; trottoir. Foot pump Pompe à pied. Foot rest Appui-pieds; repose-pied. Foot warmer Chaufferette. Foot warmer (hot water) Bouillotte. Force the pace, to Forcer le pas. Fore-carriage Avant-train. Forge Forge. Forgings Ebauchés. Fork Fourche; fourchette. Fork (of a road) Bifurcation. Form, in good En bonne forme. Forward and reverse lever Levier de changement de marche. Forward and reverse lever rod pin Axe de levier de changement de marche. Forward movement Marche en avant. Four cycle gas motor Moteur à quatre temps. Four way coil Bobine quadruple. _Frame_ _Cadre._ Frame Châssis. Frames (boat) Membrures. _Frame switch_ _Interrupteur de cadre._ _Free wheel_ _Roue libre._ _Free wheel, ratchet and pawl _Roue libre à cliquet._ clutch_ _Free wheel, roller clutch_ _Roue libre à galet._ French chalk Talc. Friction Frottement. Friction clutch Embrayage à friction. Friction plate Plateau de friction. Friction roller Galet de friction. Friction, to reduce the Réduire le frottement. Front apron } Tablier d'avant. Front board } _Front driver_ _Machine à roue motrice devant._ Front elevation Elévation de face. _Front fork_ _Fourche avant._ _Front fork blades_ _Fourreaux de fourche avant._ _Front fork crown_ _Couronne de fourche._ Front hub Moyeu avant. _Front hub adjusting cone_ _Cône de réglage du moyeu avant._ _Front hub fixed cone_ _Cône fixe du moyeu avant._ Front mudguard Garde-boue avant. _Front mudguard stays_ _Tirants du garde-boue avant._ Front rim Jante de la roue avant. Front seat Siège d'avant. _Front steerer_ _Tricycle à roue directrice devant._ Front steering bar Barre d'accouplement de direction. Front tyre Pneumatique } Bandage } de la roue avant. Caoutchouc } Front view Vue de face. Front wheel Roue avant. _Front wheel spindle nuts_ _Ecrous du moyeu avant._ Front wing Aile d'avant. Full on, to put the brake Serrer le frein à bloc. Funnel Entonnoir. Funnel, with fine strainer Entonnoir avec toile métallique fine. Funnel, with strainer Entonnoir avec grille. G Gaiter, tyre Manchon guêtre pour pneu. Garage Garage. Gas Gaz. Gas bag Ballon; poche à gaz. Gas lever Manette d'admission de gaz. Gas pipe to motor Tube d'alimentation. Gas pliers Pinces à gaz. Gas-tight Etanche au gaz. Gasket Tresse; limande de garniture; garcette. Gauge, measuring Jauge Gauge, pressure Manomètre. Gauze dust shield Grille métallique. Gauze filter Diaphragme; filtre en toile métallique. Gear Multiplication; développement; engrenage. Gear box Boîte de mouvement; boîte d'engrenages. Gear box bearings Coussinets de boîte de mouvement. Gear case Garde-chaîne; Carter; couvre-engrenages. Gear, double-driving Mouvement différentiel. Gear, in Engrené. Gear shaft Arbre de transmission; arbre de mouvement. Gear, to throw into Embrayer. Gear, to throw out of Débrayer. Gear up, to Multiplier. _Geared bicycle, ordinary_ _Bicycle multiplié._ Gearing, high Multiplication forte. General plan Plan de l'ensemble. General view Ensemble. German silver Maillechort. Gib Contre-clavette. Gill Ailette. Gimlet Vrille. Gland Presse-étoupe. Glass Glace; cristal; verre. Globe joint Joint à rotule. Goal, to reach the Gagner le poteau. Goggles Lunettes de route. Governed Commandé. Governor Régulateur. Governor ball Boule de régulateur. Governor ball fork Chape de boule de régulateur. Governor cam Came de régulateur. Governor hammer Marteau de came de régulateur. Governor hammer shaft Arbre porte-marteau de régulateur de moteur. Governor lever Levier de régulateur. Governor spring Ressort de régulateur. Governor wheel Roue de régulateur; volant de régulateur. Gradient Rampe; pente. Gradometer Indicateur de pentes. Grasshopper spring Ressort demi-pincette. Gravel Gravier. Grease Graisse. Grease, Stauffer } Graisse consistante. Grease, thick } Grease injector Seringue de graissage. Green light Feu vert. Green sheet (for lantern) Lame verte. Grid Grillage. Grind, to Roder; meuler. Groove Cannelure; rainure. Grooved pulley Poulie à gorge. Grooved shaft Arbre à rainures. Grooved wheel Roue à gorge; volant à gorge. Grounds, petrol Lie; sédiment. Gudgeon pin Goujon. Guide Guide; toc; coulisseau. Guide for clutch cone Toc d'embrayage. Guide for governor lever Toc de levier de régulateur. Gun clip Porte-fusil. Gunwale Plat-bord. Gusset Gousset. Gutter Caniveau. H Hair seat Siège en crin. Half-section Demi-coupe. Half-speed shaft Arbre à cames. Half-time gear Mouvement de réduction à 1/2. Hammer Marteau. Hand control spring Ressort d'appareil de commande d'allumage. Hand lever Levier à main. Hand pump Pompe à main. Hand pump lubricator Coup de poing. Handicap Course proportionelle. Handle Manette; poignée; manche. _Handle bar_ _Guidon._ _Handle bar stem_ _Tube plongeur du guidon._ _Handle bar switch_ _Poignée d'allumage du guidon._ Handle of oil pump Poignée de la pompe à huile. Hard pumped (tyre) Gonflé à bloc. Hardened steel Acier trempé. _Head and handlebar clip_ _Collier de serrage du guidon._ _Head and handlebar clip bolt and _Boulon et écrou du collier du nut_ guidon._ Headlight Phare. _Headlock_ _Arrêt de direction._ _Head locking nut_ _Contre-écrou de direction._ Head prop Goujon de capote. _Head socket_ _Douille de direction._ Header (of tubular boiler) Collecteur. Heat, the final La preuve finale; la belle. Heat, the first La première épreuve. Heats, to run three Faire trois épreuves. Heavy car Voiture lourde. Heavy oil Pétrole lourd. Heavy road Route pénible. Height Hauteur. Hemlock Hemlock. Hemp cord Corde chanvre. Hexagon-head bolt Boulon à 6 pans. Hickory Hickory. High speed trembler Rupteur à grande vitesse. Hill climbing trial Course de côte. Hill, to mount a Gravir une côte. Hilly Accidenté; montueux. Hind wheel Roue de derrière. Hinge Charnière; gond; compas. Hire, to Louer. Hired car Voiture de louage. Hitch Accroc; anicroche. Holding down bolt Boulon d'ancrage. Hole Trou. Hollow Creux; creuse. Hollow rim Jante creuse. Hollow tyre Caoutchouc creux. Honeycomb radiator Radiateur nid d'abeilles. Hood Capote; capuchon. Hook Crochet. Hook bolt Boulon à mentonnet. Hooter Corne d'appel. Horn Corne. Horn bracket Porte-trompette. Horn, bulb of Poire de cornet. Horn handle Poignée en corne. Hot air inlet Prise d'air chaud. House, to Remiser. Hub Moyeu. Hub brake Frein au moyeu. I Igniter Allumoir; appareil d'allumage. Ignition Allumage. Ignition cam Came d'allumage. Ignition, electric Allumage électrique. Ignition lever Manette d'allumage. Ignition, magneto Allumage magnéto-électrique; allumage par magnéto. Incandescent ignition Allumage à incandescence. Inch Pouce. Inclined water outlet Rampe de sortie d'eau. Index (cursor) Curseur. India-rubber Caoutchouc; gomme. Induction coil Bobine d'induction. Induction pipe Tube d'admission. Induction valve Soupape d'admission. Inflate, to Gonfler. Injector Injecteur. Inlet, petrol Orifice de remplissage. Inlet valve Soupape d'admission; soupape d'aspiration. Inlet valve cap Chapeau de soupape d'admission. Inlet valve cotter Clavette de soupape d'admission. Inlet valve flange Bride d'aspiration. Inlet valve seat Siège de soupape d'admission. Inlet valve spring Ressort de soupape d'admission. Inlet valve stem Tige de soupape d'admission. Inlet valve union Raccord d'aspiration. Inn Auberge. Inner tube Chambre à air. Inspection plate Plaque de regard. Insulate, to Isoler. Insulation Isolation. Insulator Isolateur. Interchangeable parts Pièces interchangeables. Intermediate shaft Arbre intermédiaire. Interruptor plug Interrupteur à cheville. Introducer (of club member) Parrain. Inverted or spray cone Cône renversé; champignon. Iron Fer. Ironmonger Quincaillier. Iron tyred wheel Roue ferrée. Irregularities of the road Déformations de la route. J Jack Vérin; cric. Japan, to Vernir. Jersey Tricot de laine. Jet condenser Condenseur à jet. Jet, petrol Gicleur; bec. Jockey pulley Poulie de tension. Joint Joint. Journal (of shaft) Tourillon. K Keel Quille. Keep Chapeau. Kerbstone Pierre de rebord. Key Clavette; clef. Key, to Caler. Key way Mortaise de clavette. Kick back Choc en arrière. Knapsack Sac. Knife Couteau. Knock A-coup. L Label Etiquette. Laced spokes Rayons tangents. _Lady cyclist_ _Vélocipédiste._ _Lady's bicycle_ _Bicyclette de dame._ _Lady's machine_ _Machine de dame._ Lamp Lanterne. Lamp bracket Porte-lanterne; porte-phare. Lamp oil Huile à brûler. Lamp side-lights Verres latéraux de lanterne. Lamp stump or socket Douille de lanterne. Landau Landau. Landaulet Landaulet. Landing place Débarcadère. Lap (in a race) Tour de piste. Lap-welded Soudé par recouvrement. Larch Mélèze. Latch Loquet. Lattice girder Poutre en treillis. Lead Plomb. Leak, to Fuir. Leakage Fuite. Leather Cuir. Leather seat Siège de cuir. _Leather top of saddle_ _Cuir de selle._ Left crank Manivelle gauche. Left handed screw Vis à filet gauche. Left, to the A gauche. Length available for carriage work Tablier. Length between perpendiculars Longueur de tête en tête. Length, to win by a Gagner d'une longueur. Lens Lentille. Level crossing Passage à niveau. Lever Levier. Lever brake Frein à levier. Liable to duty Passible de droits. Lift, valve Soulèvement; poussoir. Lifting jack Cric. Light Lumière. Light (adj.) Léger, légère. Light railway Voie légère. Light vehicle Voiture légère. Lignum vitæ Gaïac. Limousine Limousine. Linch pin Clavette; esse. Link Maillon; chaînon. Linoleum Linoleum. Linseed oil, boiled Huile de lin cuite. Live axle Essieu moteur. Lock Serrure; loqueteau. Lock nut Contre-écrou. Locksmith Serrurier. Long commutator spring Ressort de rappel de distributeur. Long distance race Course de fond. Long frame Châssis long. Longitudinal section Coupe longitudinale. Loose nut Ecrou desserré; écrou lâche. Loose road Chemin défoncé. Loose spoke Rayon desserré; rayon lâche. Loose tyre Caoutchouc décollé. Loosen a nut, to Dévisser un écrou. Loosen a screw, to Desserrer une vis. Lorry Camion. Lubricant Lubrifiant. Lubricate, to Lubrifier; graisser. Lubricating oil Huile à graisser. Lubrication Graissage. Hire, to Louer. Lubricator Graisseur. Lubricator ball seat Siège pour bille de graisseur. Lubricator glass Glace de graisseur. Lubricator pulley Poulie de graisseur. Lubricator screw for wheel cap Vis graisseur pour chapeau d'essieu. Lubricator tap Robinet pour alimentation de graisseur. Lubricator wheel Roue de commande de graisseur. Lug Oreille. Luggage Bagage. _Luggage carrier, handle bar_ _Porte-bagage de guidon._ Luggage guard Galerie. Luggage top Couvercle et galerie. Luggage van Fourgon des bagages. M Macadam Macadam. Macadamised road Chaussée en empierrement. Machine Machine. Magnet Aimant. Mahogany Acajou. Main axle Essieu principal. Main road Grande route. Maker Fabricant. Male cone Cône mâle. _Man's bicycle_ _Bicyclette d'homme._ Map Carte; plan. Maple Erable. Maple, rock Erable dur. Mask Masque. Master patent Brevet principal. Measurement over body Dimensions de la caisse. Mechanically operated Commandé mécaniquement. Member (club) Sociétaire. Membrane Membrane. Mercury Mercure. Mesh, to Engrener. Metal Métal. Metal polish Pâte à polir. Metalled road Route en pierres concassées. Methylated spirits Alcool dénaturé. Mica Mica. Mile, English Un mille anglais. Milestone Borne. Milled Molleté. Milled edge nut Ecrou molleté. Misfire Raté d'allumage. Mixing Mélange. Mixing chamber Chambre de mélange; boîte de mélange. Mixing tube Tube mélangeur. Mixture Mélange. Morocco Maroquin. Motive power Force motrice. Motor Moteur. Motor and gear Groupe moteur. Motor bearings Coussinets de moteur. _Motor bicycle_ _Motocyclette_; _bicyclette à moteur_. Motor boat Bateau à moteur. Motor car Automobile. _Motor cycle_ _Motocycle._ _Motor cyclist_ _Motocycliste._ Motor house Garage. Motor in front Moteur à l'avant. Motor launch Canot automobile. Motor piston Piston de moteur. _Motor quadricycle_ _Quadricycle à moteur._ _Motor tandem_ _Tandem à moteur._ _Motor tricycle_ _Motocycle_; _tricycle à moteur_. Motor under the seat Moteur sous le siège. Mount, to Monter. Mud Boue; crotte. Mudguard Garde-boue; garde-crotte. _Mudguard bridge_ _Tirant des tubes montants arrière._ _Mudguard stay_ _Tirant de garde-boue._ Multiple lubricator Graisseur à départs multiples. Multitubular radiator Radiateur multitubulaire. Mushroom cap Bouchon à champignon. Mushroom valve Soupape en champignon. N Nail Clou. Nail catcher Arrache-clous. Name plate Plaque d'identité. _Narrow tread bracket_ _Pédalier étroit._ Nave hoop Frette. Neat's foot oil Huile de pieds de boeuf. Neck plate, 4 slat Eventail à 4 branches. Needle Aiguille. Needle valve Pointeau. Nip, to Pincer. Nipping Pinçage. Nipple Bec; tétine. Nipple, spoke Ecrou de rayon. Noise Bruit. Noiseless Silencieux. Non-deflatable Indégonflable. Non-side-slipping Anti-dérapant. Non-skidding Anti-dérapant. Non-skidding band Bande anti-dérapante. Non-skidding protecting cover Contre-enveloppe anti-dérapante. Non-stretching belt Courroie inextensible. Non-trembler coil Bobine sans trembleur. Notch Cran. Notched quadrant Secteur denté. Nozzle Tuyère. Number Numéro. Number plate Plaque numérotée. Nut Ecrou. O Oak Chêne. Oak, live Chêne vert; yeuse. Oak, white Chêne blanc. Odometer Odomètre. Offset reducing coupling Manchon excentrique de réduction. Oil Huile. Oil bath Bain d'huile. Oil can Burette. Oil cup Godet à huile. Oil funnel Entonnoir à huile. Oil hole Trou de graissage. Oil lamp Lanterne à huile. Oil, lubricating Huile à graisser. Oil pipe to crank case Tube de la pompe à huile au moteur. Oil pipe to pump Tube du réservoir à la pompe à huile. Oil pump Pompe à huile. Oil reservoir } Réservoir à huile. Oil tank } Oil, to Huiler; graisser. Oil way Gouttière de graissage; rampe d'huile. Oiling Huilage. Omnibus Omnibus. Opening, exhaust Orifice d'échappement. Operated Commandé. Option of purchase Faculté d'achat. Order, to get out of Se détraquer. Ordinary car Voiture courante. _Ordinary geared bicycle_ _Bicycle multiplié._ Otto cycle A quatre temps. Outer cover of tyre Enveloppe. Outlet Sortie; départ. Over all Hors oeuvre. Overflow pipe Tube de trop-plein. Overhanging shaft Arbre en porte à faux. Overheating Echauffement. Overtake, to Dépasser. Oxide of lead Oxide de plomb. Oxide of zinc Oxide de zinc. P Pace Allure. Pace, to go a good Aller bon train. Pace, to increase the Accélérer. Pace-maker Entraîneur. Pack, to Emballer; garnir. Packing Emballage; garniture. Packing collar for pump Bague de garniture pour pompe. Padlock Cadenas. Panel Panneau. Para rubber Gomme de Para. Parabolic reflector Réflecteur parabolique. Paraffin Pétrole lampant; paraffine. Parcels van Voiture de livraison. Passport Passeport. Patch for repairing tyre Pastille pour réparation de pneu. Patent Brevet d'invention. Path, cycle Accotement; trottoir cyclable. Pattern Modèle; échantillon. Paved road Route pavée. Pavement Pavé. Pawl Linguet. _Peak, saddle_ _Bec de selle._ Pedal Pédale. _Pedal adjusting cone_ _Cône de réglage de pédale._ _Pedal adjusting nut_ _Ecrou de réglage de pédale._ _Pedal dust cap_ _Couvercle anti-poussiéreux de pédale._ _Pedal fastening nut_ _Ecrou d'axe de pédale._ Pedal gear Pédalier. Pedal pin Axe de pédale. _Pedal rubber_ _Caoutchouc pour pédales._ Pedal shaft Arbre de pédale. _Pedal washer_ _Rondelle de pédale._ Performance Performance. Permit Permis de circulation. Petrol Essence; pétrole. Petrol, a supply of Une provision de pétrole. Petrol can Bidon. Petrol cup Godet à pétrole. Petrol inlet Orifice de remplissage. Petrol jet Gicleur. Petrol pipe tap Robinet de tuyauterie à essence. Petrol tank Réservoir à essence; réservoir à pétrole. Petrol tank tap Robinet de réservoir à essence. Petrol warmer Réchauffeur. Petroleum Paraffine; pétrole. Petroleum lamp Lanterne à pétrole. Phaeton Phaeton. Pin Goupille. Pincers Tenailles. Pinch, to (tyre) Pincer. Pinching Pinçage. Pine Pin. Pinion Pignon. _Pillar, seat_ _Tige de selle._ Pin driver Chasse-goupille. Pin extractor Tire-goupille. Pipe from carburetter to mixing Tube du carburateur à la boîte de chamber mélange. Piping Tuyauterie. Piston Piston. Piston connecting rod Bielle de moteur. Piston pin Axe de piston. Piston rings Segments de piston. Piston rod Tige de piston. Pitch (screw-thread) Pas de vis. Pitch pine Pitch-pin. Pivot Pivot; tourillon. Plan looking upwards Plan vu de dessous. Planet wheel Roue planétaire. Planetary member Satellite. Planking Bordé. Plate Plaque. Plate clutch Embrayage à plateaux. Plate, to Nickeler. Platinum Platine. Platinum contact Contact platine. Platinum contact on trembler Contact platine de ressort de spring trembleur. Platinum tipped Tête platinée. Platinum tipped screw Vis platinée de contact. Platinum tube Tube de platine. Play Jeu. Pliers Pinces. Plotting scale Echelle de réduction. Pneumatic Pneumatique. Pneumatic tyre Caoutchouc pneumatique. Points, sparking plug Points de la bougie. Pole finder Indicateur de pôles. Pole, negative Pôle négatif. Pole piece Pièce polaire. Pole, positive Pôle positif. Polish, to Polir; astiquer. Poncelet 1 H.P. = 3/4 Poncelet. Porcelain Porcelaine. Post road Route postale. Pouch, tool Sacoche. Press, the La presse. Pressed steel Acier embouti. Pressure gauge Manomètre. Pricker Aiguille. Primary shaft Arbre primaire. Prize, to win a Gagner un prix. Projecting shaft Arbre en porte-à-faux. Projector Projecteur. Prop Tirette; renfort. Prop, fork Contrefourche. Propelling power Force motrice. Propeller Propulseur; hélice. Protecting band for tyre Protecteur de bandage; croissant de protection. Protecting cover Contre-enveloppe. Protector Protecteur. Public carriage road Grande route. Pulley Poulie. Pump Pompe. Pump, air Pompe à air. Pump bracket Support de pompe. Pump bracket stud Goujon de support de pompe. Pump clip Porte-pompe. Pump connection Raccord de pompe. Pump fan Roue à ailettes pour pompe. Pump, foot Pompe à pied. Pump, rotary Pompe rotative. Pump, stirrup Pompe à étrier. Pump, to (inflate) Gonfler. Pump tube Tube de pompe. Pump, tyre Pompe pour pneumatique. Pump union Raccord de pompe. Pump washer Rondelle pour pompe. Pump with clapper valve Pompe à battant. Puncture Perforation. Puncture proof Imperforable. Puncture, to Se perforer. Punctured tyre Pneu perforé. Purlin Panne. Q Quadrant Secteur. _Quadricycle_ _Quadricycle._ Quadruple gear wheel Roue quadruple. Quadruplet Quadruplette. R Race Course. Racing car Voiture de course. _Racing machine_ _Machine de course._ Racing man Coureur. Rack Crémaillère. Radiating fin } Ailette. Radiating flange } Radiator Radiateur. Radiator stay Tirant de radiateur. Ratchet Encliquetage; cliquet. Ratchet wheel Roue à cliquet. Rattan Rotin. Rattle, to Claquer. Rat-trap pedal Pédale à scie. Raw hide Cuir vert. Reaction spring Ressort de rappel. Record, to make a Etablir un record. Red light Feu rouge. Reed (horn) Anche. Reference mark Point de repère. Refill Recharge. Reflector Réflecteur. Regulations Règlement de circulation. Regulator Régulateur. Relief valve Soupape de trop plein. Removable Détachable; démontable. Renew, to Renouveler. Repair box Boîte nécessaire. Repair outfit Nécessaire de réparations. Repair, to Réparer. Repairer Mécanicien. Repairs, to do Faire des réparations. Re-rubbering Recaoutchouture. Reservoir Réservoir. Resin Résine. Retard sparking Retard à l'allumage. Re-tyring Recaoutchouture. Reverse movement Marche arrière. Reverse shaft Arbre de changement de marche. Reverse shaft spring Ressort d'arbre de changement de marche. _Reversible handle bar_ _Guidon réversible._ Reversing gear Changement de marche. Reversing lever Levier de changement de marche. Reversing thrust Butée de changement de marche. Revolution Tour. Revolution counter Compte-tours. Revolving seat Siège tournant. Ribbon road Route en lacets. Rideable hill Côte praticable. Rideable road Route praticable. Rifle clip Porte-fusil. Right crank Manivelle droite. Right handed screw Vis à filet droit. Right, go to the Prendre à droite. Rim Jante; couronne. Rim brake Frein sur jante. Rimer Alésoir. Ring Couronne; bague; anneau. Rivet Rivet. Rivet, to River. Rivet, chain Tourillon de chaîne. Road Route; voie; chemin. Road, bad Mauvaise route; voie impraticable. Road book Routier. Road broken up by traffic Chemin défoncé par le roulage. Road, carriage Route carrossable. Road, good Bonne route. Road map Carte routière. Road mender Cantonnier. _Roadster_ _Bicyclette de route._ Roadway Chaussée. Rod Tige. Rod for brake lever Tige de levier de frein. Rod for carburetter piston Tige de piston de carburateur Rod for clutch pedal Tige de pédale d'embrayage. Rod for differential brake Tige de frein de différentiel. Rod for single cylinder Tige entretoise de culasse. Roller Galet; rouleau. Roller bearings Coussinets à rouleaux. Roller chain Chaîne à rouleaux. Roof board Planche de toiture. Rope Corde. Rosewood Palissandre. Rotary pump Pompe rotative. Rotary valve Soupape rotative. Rough (forging) Ebauché. Round (on a track) Tour de piste. Roundabout way Détour. Row (radiator) Etage. Rubber Caoutchouc. Rubber pedal Pédale à caoutchouc. Rubber sleeve of valve Tube caoutchouc de valve. Runabout Voiturette. Rust Rouille. Rust, to Rouiller; se rouiller. Rust, to remove Dérouiller. Rut Ornière. S Saddle Selle. _Saddle clip_ _Serrage de selle._ _Saddle cover_ _Couvre-selle._ _Saddle, cushion_ _Selle à coussins._ _Saddle frame_ _Cadre de selle._ _Saddle lug_ _Raccord du pilier de selle._ _Saddle, peakless_ _Selle sans bec._ _Saddle pillar_ _Pilier de selle._ _Saddle, pneumatic_ _Selle pneumatique._ _Safety bicycle_ _Bicyclette._ Safety bolt Boulon de sécurité. Safety valve Soupape de sûreté. Sal ammoniac Sel ammoniac. Sand paper Papier de verre. Satin wood Bois de satin. Saw Scie. Screen, rotary Ecran rotatif. Screw Vis. Screw brake Frein à vis. Screw-cut, to Tarauder; fileter. Screw driver Tournevis. Screw for fastening Vis de fixation de vis de contact. platinum-tipped screw Screw for governor cam Vis de came de régulateur. Screw for horn bracket Vis de collier de trompette. Screw for piston pin Vis d'axe de piston. Screw for starting bush Vis de clavetage de la douille de mise en marche. Screw for steering Vis pour direction. Screw tap for burner Vis pointeau de brûleur. Screw tap for burner tank Vis pointeau de lampe de brûleur. Screw, to Visser. Screw wrench Clef anglaise. Scroll iron Main de ressort. Seamless tube Tube sans soudure. Seat Siège; place. Seat board Planche du siège. _Seat pillar_ _Pilier de selle_; _tube de selle_. Secondary shaft Arbre secondaire. Section iron Fer profilé. Sectional radiator Radiateur cloisonné. Sector Secteur. Sector support Support de secteur. Security bolt with spring and cap Boulon de sécurité à ressort et à chapeau. Security stud with wing nut Boulon de sécurité à oreilles. Segment Segment. Seize, to Gripper. Seizing Grippement. Self-propelling Automobile. Self-sealing tyre Pneumatique auto-réparable. _Semi-racer_ _Machine demi-course._ Set of wires Série de fils. Set screw Vis de rappel. Shackle Menotte; esse. Shade lines Traits de force. Shaft Arbre. Shearing strain Travail de cisaillement. Sheet iron Tôle de fer. Sheeting Tôlerie. Shoe, brake Sabot de frein. Shop Atelier. Short frame Châssis court. Shoulder Embase; épaulement. Show Exposition. Shutter Persienne; volet. Side board Planche latérale. Side door Portière latérale. Side elevation Elévation de côté. Side entrance Entrée sur le côté. Side plate of link Lame de maillon. Side rail for folding seat Accotoir de strapontin. Side slip Dérapage. Side slip, to Déraper. Side step Marchepied de côté. Side thrust Poussée oblique. Side timbers Ridelles. Side view Vue de côté. Sight feed lubricator Graisseur à débit visible; compte-gouttes. Silencer Silencieux; pot d'échappement. Silver plated Plaqué argent. Single ended spanner Clef simple. Single roller chain Chaîne à simples rouleaux. Single tube tyre Pneumatique à tube simple; pneumatique collé. Skid, to Patiner; déraper. Slack tyre Pneumatique dégonflé. Sleeve Manchon; douille. Slide Coulisse; glissière. Slide rod Tige de distribution. Slide rod guide Coulisseau de tige de distribution. Slide valve Tiroir. Slipping Glissement. Small connecting rod Biellette. Small plate Lame. _Smaller cog wheel_ _Petit pignon._ Smear, to Enduire; barboter. Snug Ergot. Snug, with Ergoté. Socket Manchon; douille. _Socket, head_ _Douille de direction._ Soft soap Savon noir. Solder, to Souder. Sole bar Longeron. Sole piece Semelle. Solid D'une seule pièce. Solid tyre Caoutchouc plein; bandage plein. Solid wheel Roue pleine. Spanner Clef. Spanner for steering gear Clef pour rotules de direction. Spare parts Pièces de rechange. Spark Etincelle. Spark gap Espace d'étincelle. Sparking Allumage. Sparking advance Avance à l'allumage. Sparking advance lever Manette d'avance à l'allumage. Sparking plug Bougie; inflammateur; tampon d'allumage. Sparking plug stud Goujon d'inflammateur. Sparking retard Retard à l'allumage. Specific gravity Gravité spécifique. Speed Vitesse. Speed, at full A toute vitesse. Speed gear box Boîte de vitesse. Speed indicator Indicateur de vitesse. Spindle, pinion Axe de pignon. Spindle, valve Tige de soupape. Spiral spring Ressort à boudin. Spirit Essence. Spirit lamp Lampe à alcool. Splash board Planche pare-crotte. Split Fendu. Split pin Goupille fendue. Split pulley Poulie en deux pièces. Split washer Rondelle Grover. Spoke Rai; rayon. Spoke nipple Ecrou de rayon. Spoke tightener Serre-rayon. Spoke washer Rondelle pour rais. Sponge Eponge. Spoon block Sabot forme cuiller. Spoon brake Frein à sabot; frein à patin. Sport Sport. Sprag Béquille. Sprag bracket Chape de béquille. Sprag pulley Poulie de béquille. Spray carburetter Carburateur à pulvérisation. Spray chamber Chambre de pulvérisation; chambre de diffusion. Spray nipple or nozzle Gigleur; bec. Spray vaporiser Vaporisateur à pulvérisation. Sprayer Diffuseur; cône renversé; champignon de pulvérisation. Spring Ressort. Spring box Boîte à ressort. Spring clutch Embrayage à ressort. _Spring frame_ _Cadre antivibrateur._ Spring of burner valve Ressort de vis pointeau de brûleur. Spring of compression valve Ressort de soupape de compression. Spring of contact breaker Ressort de trembleur. Spring seat Siège à ressorts. Sprocket axle support Support d'arbre de pignon de chaîne. Sprocket bolt Colonnette. Sprocket shaft Arbre de pignon de chaîne. Sprocket wheel Pignon de chaîne. Sprocket wheel washer Rondelle de pignon de chaîne. Spruce Spruce. Spur gear Engrenage droit. Spurt, to Donner un coup de collier. Square coil Bobine carrée. Squared shaft Arbre à carré. Stack of tubes Faisceau tubulaire. Stage, day's Etape journalière. Staggered En quinconces. Stand Support. Stand (for spectators) Tribune. Staple Gâche; crampon. Start, to Démarrer; mettre en marche. Starting Mise en marche; démarrage. Starting catch or bolt Verrou de mise en marche. Starting handle Manivelle de mise en marche. Starting handle axle Axe de manivelle de mise en marche. Starting pin Goupille de mise en marche. Starting pinion Pignon de mise en marche. Starting pinion bush Douille de pignon de mise en marche. Stay Tirant; entretoise. Stay rod Tige entretoise. Stay tube Tube tirant. Steel Acier. Steel, cold drawn Acier étiré à froid. Steel cord Corde en acier. Steel rim Jante en acier. Steel wire Fil d'acier. Steep ascent Montée rapide. Steep descent Descente rapide. Steep gradient Forte rampe. Steer, to Diriger. Steering Direction. Steering axle Essieu directeur. Steering bar Barre de direction. Steering collar Emplanture pour direction. Steering column Tube de direction; barre verticale de direction. Steering gear box Boîte de direction. Steering lever Levier de direction. _Steering lock_ _Arrêt de direction._ _Steering post_ _Tube intérieur de direction._ Steering quadrant Secteur de direction. Steering rod Bielle de commande de direction; tige de direction. Steering rod bolt Axe de bielle de direction. Steering sector Secteur pour direction. Steering shaft Arbre de direction. _Steering wheel_ _Roue directrice._ Steering wheel, hand Volant de direction. Stem (boat) Etrave. _Stem, handle bar_ _Tube plongeur de guidon._ Stem, valve Tige de soupape. Step Marchepied. Step bearing Crapaudine. Step pulley Poulie étagée. Step tread Palette de marchepied. Stern frame Cadre d'hélice. Stern post Etambot. Stern tube Tube d'arbre de l'hélice. Sticking plaster Taffetas. Stirrup pump Pompe à étrier. Stop Butoir. Stop, to S'arrêter. Stop valve Soupape d'arrêt. Stoppage Arrêt. Stopping place Etape. Straighten, to Redresser. Strap Courroie. Street Rue. Stroke of piston Course du piston. Stud Goujon. Stud bolt Colonnette. Stud, security Boulon de sécurité. Stud with projection Goujon ergot. Studded tread band Protecteur antidérapant à rivets. Stuffed Rembourré Stuffing box Presse-étoupe; boîte à garniture. Subscription Abonnement; cotisation. Suction Aspiration. Suction stroke Temps d'aspiration. Suction tubing Tuyauterie d'aspiration. Suction valve cap Bouchon d'aspiration. Suction valve flange Bride d'aspiration. Sulphuric acid Acide sulfurique. Superheater Surchauffeur. Support Support. Support for spring Main de support. Surface carburetter Carburateur par surface. Surface condenser Condenseur par surface. Syringe Seringue. Switch Interrupteur. Switch block Sabot d'interrupteur. Switch off, to Couper le circuit. Switch on, to Fermer le circuit. Swivel Emerillon. T Tack Pointe. Tail-board Tablier d'arrière. Tail board fastening (wagon) Fermeture de hayon. Tail board hook Crochet de tablier. Tail end shaft Arbre porte-hélice. Tallow wood Arbre à suif. Tandem Tandem. _Tandem safety_ _Bicyclette-tandem._ _Tandem tricycle_ _Tricycle tandem._ Tangent spokes Rayons tangents. Take to pieces, to Démonter. Tank Réservoir. Tap Robinet. Tap, screwing Taraud. Taper pin Goupille conique. Tappet Toc; broche d'entraînement. Tarpaulin Bâche. Tax plate Plaque de contrôle. Teak Teck. Tee Té. Telescopic pump Pompe télescope. Template Gabarit. Tenon Tenon. Terminal Borne. Thimble Cosse. Thong Lanière. Thread, to Fileter. Threaded pin Goupille filetée. Three way tap Robinet à trois voies. Three way water tap Robinet à trois débits pour circulation d'eau. Thread (screw) Filet. Throttle valve Soupape à papillon; étrangleur. Throw out of gear, to Débrayer. Thrust Poussée; butée. Thrust bearing Palier de butée. Thrust block Butée. Thrust collar Bague de butée. Thrust rod Bielle de poussée. Thrust screw Vis de poussée. Ticket of membership Certificat de membre. Ticking for covering cushions Toile treillis pour coussins. Tighten, to Serrer; tendre. Tightener, belt Tendeur pour courroie. Tiller Barre. Timekeeper Chronométreur. Timing gear Appareil d'avance à l'allumage. Timing sector or quadrant Secteur pour avance à l'allumage. _Toe clip_ _Rattrape de pédale_; _calepieds_. Tool bag Sacoche. Tool pouch Sacoche. Tommy bar Broche. Tonneau Tonneau. Tongs Tenailles; pinces. _Top head cup_ _Raccord supérieur avant._ Top part of diaphragm Cuvette de piston à air. Top shaft Arbre supérieur. _Top tube_ _Tube supérieur_; _tube horizontal_. Torque Torque. Tour Voyage; tournée. Touring Le tourisme. Touring car Voiture de tourisme. Tourist Touriste. Tow, to Remorquer. Track, racing Piste. Tractive power Effort de traction. Tractor Tracteur. Trade, the Le commerce. Trade mark Marque de fabrique. Traffic, heavy Encombrement de voitures. Trailer Voiturette remorque. Tread Chape; bande de roulement; croissant de protection. Trembler Trembleur; rupteur. Trembler coil Bobine à trembleur. _Tricycle_ _Tricycle._ Trip Voyage de plaisir. Trip rod Culbuteur. Trip rod collar Bague de culbuteur. Trip rod collar pin Goupille de bague de culbuteur. Triple gear wheel Roue triple. Triple inlet valve seat Siège triple de soupape d'aspiration. Trouser clip Pince-pantalon. True, to Rectifier. True a wheel, to Centrer une roue. Tube Tube. Tube expander Sertisseur. Tubular box spanner Clef en tube concentrique. Tubular steel shaft Arbre tube acier. Turning handle Poignée tournante. Turnpike road Route de grande communication. Turpentine Térébenthine. Tyre Caoutchouc; pneumatique; bandage. Tyre cement Colle; mastic. Tyre cover Enveloppe. Tyre pump Pompe à pneumatique. Tyre remover Démonte-pneu; démonte-bandage. Tyre solution Dissolution. Twin tap Robinet de mélange. Twist belt Courroie torse. _Two speed machine_ _Machine à deux vitesses._ Two to one gear Mouvement de dédoublement. Two to one shaft Arbre à cames. Two way tap Robinet à deux voies. U Unattached Indépendant. Underframe Châssis inférieur. Under stem of carburetter Dessous de carburateur. Uniform, club Costume social. Union Raccord. Union, cycling Union vélocipédique. Universal joint Joint universel; joint à rotule. Universal shackle Jumelle. Unpuncturable Imperforable. Unrideable Impraticable. Unrivet, to Dériver. Unscrew, to Dévisser. Up hill, to go Monter une côte. Upholstered Garni; capitonné. Upholstering Garniture. V V belt Courroie trapézoïdale; courroie en V. V block on trembler Bloc en V du trembleur. Valve, petrol inlet Clapet d'alimentation; pointeau d'arrivée d'essence. Valve Valve; soupape; clapet. Valve chain Chaînette de valve. Valve chamber Chambre de soupapes. Valve chamber cap Bouchon de chambre des soupapes. Valve cone Cône de soupape. Valve dust cap Bouchon de soupape. Valve lifter Lève-soupape. Valve plug (tyre) Obus. Valve seat Siège de soupape. Valve spindle } Tige de soupape. Valve stem } Valve, to grind a Meuler une soupape. Van Voiture de livraison. Van, large Fourgon de livraison. Vapourising carburetter Carburateur à évaporation. Variable speed Vitesse variable. Vehicle Véhicule. Ventilator Ventilateur. Vertical section Coupe verticale. Vibration Trépidation. Vice Etau. Victoria Victoria. Voltage Voltage. Voltmeter Voltmètre. Vulcanised fibre Fibre vulcanisée. Vulcanised rubber Caoutchouc vulcanisé. W Wagonette Wagonnette. Wallet Sacoche. Walnut Noyer. Warmer Réchauffeur. Warming pipe Tube-réchauffeur. Wash-board Fargue. Washer Rondelle. Waste oil screw Vis de purge pour l'huile de graissage. Waste oil tap Robinet de purge pour l'huile de graissage. Waste petrol screw Vis de purge pour carburateur. Waste petrol tap Robinet de purge pour carburateur. Watch holder Porte-montre. Water Eau. Water cap Bouchon de réservoir. Water circulation Circulation d'eau. Water circulation connection Tubulure pour circulation d'eau. Water cooling Refroidissement à l'eau. Water gauge Niveau d'eau. Water gauge glass Tube de niveau d'eau. Water jacket Culasse à eau; enveloppe d'eau. Water receiver round exhaust valve Poche d'eau autour de la soupape d'échappement. Waterproof Imperméable; étanche à l'eau. Waterproof bag Sac en toile caoutchoutée. Waterproof cape Pèlerine. Water tank Réservoir à eau; caisse à eau. Water tube Bouilleur. Watering cart Arrosoir; tonneau d'arrosage. Wear and tear Usure. Web (of a beam) Ame. Wedge Coin; cale. Weighing machine Bascule. Weight Poids. Weld, to Souder. Weldless Sans soudure. Well seat Siège profond. Wheel Roue. Wheel base Empattement. Wheel cap Chapeau de roue. Wheel cap spanner Clef pour essieux de voitures. Wheel gauge Ecartement des roues. Wheel guard Couvre-roues. Wheel iron head Embrasure de ressort. Wheel pulley Poulie jante. Whip Cravache. Whistle Sifflet. White light Feu blanc. Wick Mèche. Wind Vent. Wind, head Vent contraire. Wind shield Contrevent. Winding road Route en lacets. Window blind Store. Wing Aile. Winged nut Ecrou à oreilles. Winning post Poteau d'arrivée. Wipe contact Distributeur d'allumage. Wire clamp Serre-fil. Wire clamp for commutator Serre-fil pour distributeur d'allumage. Wire clamp for timing sector Serre-fil pour secteur d'avance à l'allumage. Wire drawing of steam Laminage de la vapeur. Wire gauze Toile métallique. Wire, iron Fil de fer. Wire rope Câble métallique. Wire seat Siège à tissu métallique. Wired on cover Enveloppe à tringles. Wooden rim Jante en bois. Wooden seat Siège de bois. Working drawing Dessin d'exécution. Working load Charge utile. Working parts Pièces mécaniques. Working pressure Pression effective. Workmanship Main d'oeuvre. Works Ateliers; fabrique; usine. Worm Filet; vis sans fin. Wrench, adjustable Clef anglaise. Wrist pin Axe d'assemblage. Wrought iron Fer forgé. Y Yew If. Yoke Etrier. Z Zinc Zinc. FRENCH-ENGLISH. Abonnement Subscription. Acajou Mahogany. _Acatène_ _Chainless._ Accélérateur Accelerator. Accessoires Accessories. Accidenté Hilly. Accotement Cycle path. Accotoir de strapontin Side rail for folding seat. Accumulateur Accumulator; storage battery. Acétylène Acetylene. Acétylite Acetylite. Acier embouti Pressed steel. Acier trempé Hardened steel. A-coup Knock. Affaisser, s' To collapse (of tyres). Agencement Fitting. Agrafe de courroie Belt fastener. Aiguille Needle; pricker. Aile Wing. Aile d'arrière Back wing. Aile d'avant Front wing. Ailette Gill; flange; fin. Ajouré With an opening. Alcool dénaturé Methylated spirits. Alésage Bore. Alésoir Rimer. Allumage Ignition; sparking. Allumage à incandescence Tube ignition. Allumage électrique Electric ignition. Allumage magnéto-électrique Magneto-ignition. Allumage par magnéto Magneto-ignition. Allumage prématuré Back fire. Allumeur Contact breaker. Allumoir Lighter; igniter. Ame Web. Amiante Asbestos. Ampérage Amperage. Ampère Ampere. Ampèremètre Ammeter. Ampoule verre Glass bulb. Anche Reed. Anti-dérapant Non-skidding. Arbre à cames Cam shaft. Arbre à carré Squared shaft. Arbre à plateaux Flanged shaft. Arbre d'accélérateur Accelerator shaft. Arbre de changement de vitesse Change speed shaft. Arbre de différentiel Differential shaft. Arbre de direction Steering shaft. Arbre d'embrayage Clutch shaft. Arbre de moteur Engine shaft; motor shaft. Arbre de mouvement Gear shaft. Arbre de pédale Pedal shaft. Arbre de pignon de chaîne Sprocket shaft. Arbre de ralentisseur Accelerator shaft. Arbre de transmission Gear shaft; counter shaft. Arbre en porte-à-faux Overhanging or projecting shaft. Arbre inférieur Clutch shaft; bottom shaft. Arbre intermédiaire Reverse shaft; counter shaft; intermediate shaft. Arbre porte-hélice Tail end shaft. Arbre porte-marteau de régulateur Governor hammer shaft. de moteur Arbre primaire Primary shaft. Arbre secondaire Secondary shaft. Arbre supérieur Top shaft. Arrache-clous Nail catcher. _Arrêt de direction_ _Headlock_; _steering lock_. Arrière-train After carriage. Arrivée d'essence Petrol inlet. Aspiration Suction. Astiquer To polish. Atelier Workshop. Attache Clamp. Automobile Self-propelling; motorcar. Autoréparateur, -rice Self-sealing. Avance à l'allumage Sparking advance. Avance à l'allumage, appareil d' Timing gear. Avant-train Fore-carriage. Axe Axle; bolt; pin; spindle. Axe d'articulation de direction Steering rod bolt. Axe d'assemblage Wrist pin. Axe de bielle de direction Steering rod bolt. Axe des abscisses Datum line. Axe de flotteur de carburateur Carburetter float spindle. Axe de fourchette porte-galet Exhaust fork roller bolt. d'échappement Axe de frein Brake pin. Axe de galet du levier Exhaust fork roller bolt. porte-galet de moteur. Axe de levier de changement de Forward and reverse lever rod pin. marche Axe de manivelle de mise en marche Starting handle axle. Axe des mâchoires du frein de Differential brake bolt. différentiel. Axe de pédale Pedal pin. Axe de pignon Pinion spindle. Axe de piston Piston pin; gudgeon pin. _Axe de volant_ _Driving shaft._ _Axe du pédalier_ _Crank axle._ Axe en axe, d' Centre to centre. _Axe moteur_ _Driving shaft._ Axe principal Main axle. Axe supportant les distributeurs Commutator cam shaft. d'allumage. B Bac d'accumulateur Containing case. Bâche Tarpaulin. Bague Collar; bush. Bague à collerette Flanged collar. Bague de biellette de rappel de Collar for digger. tige Bague de butée Thrust collar. Bague de captation Thrust collar. Bague de culbuteur Trip rod collar. Bague de centrage Centering ring. Bague de corps de distributeur Commutator bush. d'allumage _Bague de réglage de direction_ _Steering head lock nut._ Bain d'huile Oil bath. Balai Brush. Balai des distributeurs d'allumage Commutator brush. Ballon Gas bag; canopy. Ballon démontable Removable canopy. Bandage Tyre. Bandage plein Solid tyre. Bande anti-dérapante Non-skidding band. Bande de roulement Tread. Baquet Bucket seat. Barbotage Smearing. Barboter To smear or daub. Barre d'accouplement de direction Front steering bar. Barre franche Tiller. Bascule Weighing machine. Basse tension Low tension. Bateau à moteur Motor boat. Bâti de moteur Crank case. Batterie Battery. Batterie de piles sèches Dry battery. Bec Nipple; burner. _Bec de selle_ _Peak of saddle._ _Bécane_ _Bike._ Béquille Sprag; devil. _Bicycle multiplié_ _Ordinary geared bicycle._ _Bicyclette_ _Safety bicycle._ _Bicyclette à moteur_ _Motor bicycle._ _Bicyclette de dame_ _Lady's bicycle._ _Bicyclette d'homme_ _Man's bicycle._ _Bicyclette pliante_ _Folding bicycle._ _Bicycliste_ _Bicyclist._ Bidon Petrol can; oilcan. Bielle Connecting rod; rod. Bielle de changement de vitesse Change speed connecting rod. Bielle de commande de débrayage Brake and clutch lever connecting et de frein rod. Bielle de commande de direction Steering rod. Bielle de commande de frein Brake lever connecting rod. Bielle de commande de piston de Carburetter connecting rod. carburateur Bielle de moteur Piston connecting rod. Bielle de poussée Thrust rod. Bielle de rappel de tige Digger connecting rod. Bielle de tension de chaîne Chain adjusting rod. Biellette Small connecting rod. Bille Ball. Bille de carburateur Carburetter ball or valve. Bille de graisseur Lubricator ball. Biseauté Bevelled. Blindage Casing. Blindé Cased. Bloc Block. Bloc de chaîne Chain block. Bloc du trembleur Trembler block. Bloc, gonflé à Hard pumped (tyre). Bloc, serrer le frein à To put the brake full on. Bobine à trembleur Trembler coil. Bobine carrée Square coil. Bobine d'induction Induction coil. Bobine quadruple 4-way coil. Bobine sans trembleur Non-trembler coil. Bois d'arbre à suif Tallow wood. Boisseau de butoir Buffer guide. Boîte Box. Boîte à garniture Stuffing box. Boîte à graisse Axle box. Boîte à ressort Spring box. Boîte de différentiel Differential gear box. Boîte de direction Steering gear box. Boîte d'engrenages Gear box. Boîte de mélange Mixing chamber. Boîte de mouvement Gear box. Boîte de vitesse Speed gear box. Boîte du flotteur Float chamber. Boîte nécessaire Repair box. Bombé Convex. Bordé Planking. Borgne Blind. Borne Terminal. Bouche-trou Cap for oil hole. Bouchon Cap; plug; nipple. Bouchon à champignon Mushroom cap. Bouchon d'accumulateur Accumulator cap. Bouchon d'aspiration Suction valve cap. Bouchon de dessus de carburateur Carburetter float cap. Bouchon d'échappement Exhaust valve cap. Bouchon d'emplissage de réservoir Cap for water pipe. d'eau Bouchon d'inflammateur Firing nipple. Bouchon de réservoir Water cap. Bouchon du regard d'échappement Exhaust valve inspection cap. Bouchon de valve Valve cap. Bouchon de vidange Blow off plug. Bouchon registre de prise d'air Carburetter air cap. pour carburateur Bougie Sparking plug. Bouilleur Water tube. Bouillotte Footwarmer (water). Boule de régulateur Governor ball. Bouleau Birch-wood. Boulon Bolt. Boulon à mentonnet Hook bolt. Boulon d'ancrage Holding down bolt. Boulon de frein Brake screw. Boulon de sécurité Safety bolt; security stud. Boulon de sécurité à oreilles Security stud with wing nut. Boulon de sécurité à ressort et à Security stud with spring and cap. chapeau _Boulon du collier de direction_ _Head and handle bar clip bolt._ Boulon, 6 pans Hexagon head bolt. Boulon et écrou Bolt and nut. Boulon et écrou de chaîne Chain bolt and nut. _Boulon et écrou de la tige de _Seat pillar bolt and nut._ selle_ Bourrelet Beaded edge of tyre cover. Bouton Button. Bouton d'arrêt Stop button. Bouton de manivelle Crank pin. Bouton de porte Door handle. Braser To braze. Brassière Arm sling. Brevet d'invention Patent. Brevet principal Master patent. Bride Clamp; flange. Bride d'aspiration Inlet valve flange. Bride d'échappement Exhaust valve flange. Bride de ressort Clip for spring. Briquet Clamp. Broche Tommy bar; drift; gudgeon pin. Broche d'entraînement Tappet. Brosse à chaîne Chain brush. Brûleur Burner. Buis Box-wood. Burette Oil can. Butée Thrust block. Butée à billes Ball bearing thrust. Butée de changement de marche Reversing thrust. Butoir Stop. C Cab Cab. Câble Wire; rope. Câble flexible Flexible wire. Cache-poussière Dust cap. _Cadre_ _Frame._ _Cadre à ressorts_ _Spring frame._ _Cadre antivibrateur_ _Spring frame._ _Cadre de selle_ _Saddle frame._ _Cadre en croix_ _Cross frame._ Cadre d'hélice Stern frame. Caisse Body. Caisse à eau Water tank. Caisse pliante Folding crate. Cale Block; wedge. _Calepieds_ _Toe clip._ Caler To key. Calfater To caulk. Calotte de soupape d'aspiration Inlet valve cap. Calotte de timbre Dome of bell. Came Cam. Came d'allumage Ignition cam. Came d'échappement Exhaust lift cam. Came de régulateur Governor cam. Came fibre Fibre cam. Camion Dray; lorry. Caniveau Gutter. Canot automobile Motor launch. Caoutchouc India rubber; tyre. _Caoutchouc cannelé pour pédales_ _Fluted pedal rubber._ Caoutchouc creux Hollow tyre. Caoutchouc plein Solid tyre. Caoutchouc pneumatique Pneumatic tyre. _Caoutchouc pour pédales_ _Pedal rubber._ Capitonné Upholstered. Capot couvre-moteur Bonnet. Capote Hood. Capuchon Hood. Capuchon de brûleur Burner guard. Capuchon de lanterne Flame guard. Carburateur Carburetter. Carburateur à évaporation Vapourising carburetter. Carburateur à niveau constant Constant level carburetter. Carburateur à pulvérisation Spray carburetter. Carburateur par surface Surface carburetter. Carbure de calcium Carbide. Cardan Cardan; arbor shaft. Carneau Fire-tube. Carrefour Crossways. Carrosserie Carriage work. Carrossier Carriage builder. Carter Crank case; gear case. Carton d'amiante Asbestos millboard. Catalytique Catalytic. Catalyse Catalysis. Cèdre Cedar. Celluloïd Celluloid. Cémenter To case-harden. Centrer une roue To true a wheel. Chaîne Chain. Chaîne à blocs Block chain. Chaîne à doubles rouleaux Double roller chain. Chaîne à rouleaux Roller chain. Chaîne à simples rouleaux Single roller chain. Chaînette de valve Valve chain. Chaînon Link of chain. Chambre à air Air tube; inner tube. Chambre de combustion Combustion chamber. Chambre d'explosion Explosion chamber. Chambre de diffusion Spray chamber. Chambre de mélange Mixing chamber. Chambre de pulvérisation Spray chamber. Chambre de soupapes Valve chamber. Champignon Inverted cone. Champignon de pulvérisation Sprayer. Chanfreiner To chamfer. Changement de marche Reversing gear. Changement de vitesse Change speed gear. Chape Tread of tyre; end; bracket; fork. Chape de béquille Sprag bracket. Chape de boule de régulateur Governor ball fork. Chape du cliquet de levier de Change speed lever catch fork. changement de vitesse Chape de levier de frein Brake lever end. Chape de piston du carburateur Carburetter piston rod end. Chape de tige de frein Brake rod end. Chape de tige entretoise de Cylinder head stay end. culasse Chapeau Cap; keep. Chapeau de palier Bearing keep. Chapeau de roue Wheel cap. Chapeau de soupape Valve cap. _Chapeau de tension_ _Cap of draw-link._ Charge de rupture Breaking strain. Charge utile Working load. Charger To charge. Charnière Hinge. Charnière avec cache-fente Concealed hinge. Chasse-clous Nail-catcher. Chasse-goupille Pin driver. Châssis Chassis; frame. Châssis cintré Curved frame. Châssis court Short frame. Châssis inférieur Under-frame. Châtaignier Chestnut. Chaudière Boiler. Chaudière à vaporisation Flash boiler. instantanée Chaufferette Footwarmer. Chaussée Roadway. Chaussée en empierrement Macadamised road. Chemin Road. Chemin forain Wide thoroughfare. Cheminée d'aspiration Air chimney. Chêne Oak. Chêne blanc White oak. Chêne vert Live oak. Chevaux effectifs, force en Brake horse-power. Cheville de l'interrupteur Connecting plug. Chicanes, en Arranged as baffles. Choc en arrière Back fire; back kick. Circulation d'eau Water circulation. Cisaillement, travail de Shearing strain. Clapet Flap valve; valve. Clapet d'alimentation Feed valve. Claquer To rattle. Clavette Key; cotter; linch-pin. _Clavette de pédalier_ _Bottom bracket cotter pin._ Clavette de soupape d'admission Inlet valve cotter. Clef Spanner. Clef américaine à molette Billing spanner. "Billing." Clef anglaise Screw wrench. Clef à deux branches Double branch spanner. Clef à douille Box spanner. Clef de serrage Spanner. Clef double Double ended spanner. Clef en tube concentrique Tubular box spanner. Clef pour essieux de voitures Wheel cap spanner. Clef pour rotules de direction Spanner for steering gear. Clef simple Single ended spanner. Clin, à Clincher built. Clinquant Foil. Cliquet Catch; ratchet. Cliquet de levier de changement Change speed lever catch. de vitesse Cliquet de levier de frein Brake lever catch. Clochette Bell. Cloison Partition. Clou à parquet Brad. Coefficient de friction Coefficient of friction. Coin Wedge. Colle Cement (for tyres). Collecteur Commutator; header (of boiler). Collet Collar. Collier Band; strap. Collier d'excentrique Eccentric strap. Collier de frein Brake band; brake clip. _Collier de levier de frein_ _Brake detachable clip._ _Collier de réglage des cuvettes _Bottom, bracket adjusting de pédalier_ collar._ Collier de serrage Clip. _Collier de serrage de direction_ _Head and handle bar clip._ Collier de trompette Horn bracket. _Collier de tube de frein_ _Brake adjusting clip._ Colonnette Sprocket bolt; stud bolt. Commandé Operated; governed. Compas Hinge. Compte-gouttes Drip feed lubricator. Compte-tours Revolution counter. Condenseur à jet Jet condenser. Condenseur à surface Surface condenser. Cône Cone. Cône d'embrayage Clutch cone. _Cône de moyeu arrière_ _Back hub cone._ _Cône de moyeu avant_ _Front hub cone._ _Cône de pédale_ _Pedal cone._ Cône de réglage Adjusting cone. _Cône du raccord inférieur avant_ _Bottom head cone._ Cône femelle Female cone. _Cône fixe du moyeu arrière_ _Rear hub fixed cone._ _Cône fixe du moyeu avant_ _Front hub fixed cone._ Cône mâle Male cone. Cône renversé Inverted or spray cone. Congé Fillet. Contact platine Platinum contact. Contour Outline. Contre-clavette Gib. Contre-écrou Lock-nut. _Contre-écrou de direction_ _Head locking nut._ _Contre-écrou du pignon arrière_ _Chain ring lock nut._ Contre-enveloppe Protecting cover. Contrefourche Fork prop. _Contrepédaler_ _To back-pedal._ Contre-plaque Baffle plate. Contrepoids Balance weight. Contrepoids de vilebrequin Crank back-balance. Contre-pression Back pressure. Contrevent Wind shield. Corde Cord. Corde d'amiante Asbestos cord. Corde de chanvre Hemp cord. Corde en acier Steel cord. Cornet d'alarme Horn; hooter. Cornière Angle bar. Cosse Thimble. Costume social Club costume. Côte praticable Navigable hill. Coude Elbow. Coulisse Slide. Coulisseau Block; guide. Coulisseau de tige de distribution Slide rod guide. Coup, à- Knock. Coup de collier Spurt. Coup de poing Hand pump. Coupe Section. Coupé Brougham. Coupe-circuit Cut-out. Coupe longitudinale Longitudinal section. Coupe transversale Cross section. Coupe verticale Vertical section. Couper le circuit To switch off. Courant Current. Couronne Ring; crown; rim. Couronne de billes Ball race. _Couronne de fourche avant_ _Front fork crown._ Courroie Belt; strap. Courroie à talon Edged belt. Courroie collée Cemented belt. Courroie cousue Sewn belt. Courroie en =V= =V= belt. Courroie inextensible Non-stretching belt. Courroie poil de chameau Camel hair belt. Courroie sans fin Endless belt. Courroie torse Twist belt. Courroie trapézoïdale =V=-belt. Course du piston Stroke of piston. Course de côte Hill climbing trial. Course de fond Long distance race. Coussin Cushion. Coussinet Bearing. Coussinets à billes Ball bearings. Coussinets à cônes réglables Adjustable cone bearings. Coussinets à cuvettes réglables Adjustable cup bearings. Coussinets à double filet Double ball bearings. Coussinets ajustables Adjustable bearings. Coussinets à rouleaux Roller bearings. Coussinets de boîte de mouvement Gear box bearings. Coussinets de moteur Motor bearings. Couvercle Cover; canopy; top. Couvercle antipoussiéreux Dust cap. Couvercle d'allumage Cover of contact breaker. Couvercle d'arbre à cames Cam shaft cover. Couvercle de culasse Cylinder head cover. Couvercle démontable Removable canopy. Couvercle et galerie Luggage top. Couvre-chaîne Chain guard. Couvre-engrenages Gear case. Couvre-roues Wheel guard. _Couvre-selle_ _Saddle cover._ Crampon Staple. Crapaudine Step bearing. Crémaillère Rack. Crevaison Burst (tyre). Crever To burst; to collapse. Cran Notch. Cric Lifting jack. Cristal Glass. Crochet Bell fastener; hook. Crochet de tablier Tailboard hook. Crochets de la jante Clinch of the rim. Croisillon Cross shaft. Croissant de protection Protecting band; tread. Crosse Cross head. Crupon pour courroie Belt-butt. Cuir Leather. Cuir chrome Chrome leather. _Cuir de selle_ _Leather top of saddle._ Cuir vert Raw hide. Cuivré Copper plated. Cuivre jaune Brass. Cuivre rouge Copper. Culasse Cylinder head. Culasse à eau Water jacket. Culbuteur Trip rod; digger. Culotte Bridge piece. Culotte d'aspiration Bridge piece for inlet valve. Culotte d'échappement Bridge piece for exhaust. Curseur Index; cursor. Cuvette Ball race; cup (of bearings). Cuvette arrière d'essieu à billes Ball race for back axle. Cuvette avant d'essieu à billes Ball race for front axle. Cuvette de brûleur Burner cup or pan. _Cuvette de pédalier_ _Bottom bracket barrel._ Cuvette de piston à air Top part of diaphragm. Cylindre Cylinder. Cylindre-culasse Centaur cylinder. D Dard Dragon tongue. Débit Feed. Débrayer To disengage; to de-clutch. Débrayer la courroie To throw off the belt. Déchets de coton Cotton waste. Décompression Compression relief. Déformations de la route Irregularities of the road. Dégonfler To deflate. Démarrage Starting. Démarrer To start. Demi-coupe Half section. Démontable Detachable. Démonte-bandage } Tyre remover. Démonte-pneu } Démonter To take to pieces. Démonteur de bandage Tyre remover. Densimètre Densimeter. Dent de roue Cog. Denture Tooth; cog. Départ Outlet. Dérapage Side slip. Déraper To side slip; to skid. Descente dangereuse Dangerous hill. Désengrener To throw out of gear. Dessin d'exécution Working drawing. Dessous de carburateur Under stem of carburetter. Détente de vapeur Expansion of steam. Détraquer To get out of order. Développement Gear. Déversoir Flooder. Diaphragme Diaphragm. Diffuseur Sprayer. Dimensions de la caisse Measurement over body. Direction Steering; _head of a bicycle_. Disposition schématique Diagrammatic arrangement. Disque Disc. Disque d'excentrique Eccentric sheave. Dissolution Tyre solution. Distance Distance. Distance parcourue Distance run. Distributeur d'allumage } Distributeur de courant pour } Commutator; wipe contact. allumage } Domaine public, le brevet est The patent has expired. dans le Douille Bush; sleeve. _Douille de direction_ _Head socket._ Douille de lanterne Lamp stump. Douille de mise en marche Starting pinion bush. Douille de régulateur Governor sleeve. Dressé au tour Faced in the lathe. Dynamo Dynamo. E Ebauché Rough; forging. Ebène Ebony. Ecartement des essieux Distance between axles. Ecartement des roues Wheel gauge. Echappement Exhaust. Echauffement Overheating. Echelle de réduction Plotting scale. Eclater To burst (tyre). Ecrou Nut. Ecrou à encoches } Castle nut. Ecrou à entailles } Ecrou à oreilles Butterfly nut. Ecrou borgne Cap nut. _Ecrou d'axe de pédale_ _Pedal fastening nut._ Ecrou d'essieu à billes Ball bearing axle arm nut. Ecrou de rayon Spoke nipple. _Ecrou de réglage de pédale_ _Pedal adjusting nut._ _Ecrou du collier de direction_ _Head and handle bar clip nut._ _Ecrou du moyeu arrière_ _Back hub spindle nut._ _Ecrou du moyeu avant_ _Front hub spindle nut._ Ecrou molleté Milled edge nut. Effort de flexion Bending strain. Effort de traction Tractive power. Elément Cell. Elévation de bout End elevation. Elévation de côté Side elevation. Elévation de face Front elevation. Email Enamel. Emailler To enamel. Embase Shoulder. Embouti Dished; pressed. Embrasure de ressort Wheel iron head. Embrayage Clutch. Embrayage à cônes Cone clutch. Embrayage à friction Friction clutch. Embrayage à griffes Dog clutch. Embrayage à plateaux Plate clutch. Embrayage à ressort Spring clutch. Embrayer To throw into gear; to clutch. Emérillon Swivel. Empattement Wheel base. Emplanture pour direction Steering collar. Encliquetage Ratchet. Enduire To smear. Enduit pour courroies Belt grease; belt dressing. Engrenage Gear. Engrenage à chevrons Double helical gear. Engrenage conique Bevel gear. Engrenage de dédoublement Two to one gear. Engrenage droit Spur gear. Engrené In gear. Engrener To mesh (of cog wheels). Ensemble General view. Entonnoir Funnel. Entonnoir avec grille Funnel with strainer. Entonnoir avec toile métallique Funnel with fine strainer. fine Entourage Bonnet. Entrée sur le côté Side entrance. Entretoise Stay. _Entretoise des tubes montants _Mudguard bridge._ arrière_ _Entretoise fourche arrière_ _Back fork bridge._ Enveloppe Cover; outer cover of tyre. Enveloppe d'eau Water jacket. Enveloppe du vilebrequin Crank case. Enveloppe protectrice Protecting cover. Epaulement Shoulder. Equerre Angle plate. Erable Maple. Erable dur Rock maple. Ergoté With snug. Esse Linch-pin; shackle. Essence Petrol; spirit. Essieu Axle. Essieu à billes Ball bearing axle. Essieu brisé Divided axle. Essieu directeur Steering axle. Essieu droit Straight axle. Essieu coudé Crank axle. Essieu moteur Driving axle; live axle. Essieu porteur Carrying axle. Essieu tournant Live axle. Etage (radiateur) Row. Etambot Stern post. Etanche à la poussière Dust proof. Etape Stopping place. Etape journalière Day's stage. Etincelle Spark. Etincelle chaude Fat spark. Etiquette Label. Etiré à froid Cold drawn. Etoquiau Detent pin. Etrangler To throttle. Etranglement Throttling. Etrave Stem. Etrier Yoke. Etudier To design. Eventail à 4 branches 4 slat neck plate. Explosion prématurée Back fire. Exposant Exhibitor. Exposition Exhibition; show. Extincteur Extinguisher. F Fabrique Factory. Faisceau tubulaire Stack of tubes. Fargue Wash-board. Fendu Split. Fer en U Channel iron. Fer forgé Wrought iron. Fer profilé Section iron. Fermer le circuit To close the circuit. Fermeture Closing; fastening. Fermeture de hayon Tailboard fastening. Feu blanc White light. Feu rouge Red light. Feu vert Green light. Fibre Fibre. Fibre isolante Insulation fibre. Fil d'acier Steel wire. Fil de fer Iron wire. Fil électrique Electric wire. Filet Thread of a screw. Filetage double mâle Double male screwed. Filtre Filter. Flasque Cheek. Flotteur Float. Flotteur de carburateur Carburetter float. Fonte Cast iron. Forte rampe Steep gradient. Fou, folle Loose. _Fourche arrière_ _Back fork._ _Fourche avant_ _Front fork._ Fourchette Fork. Fourchette d'échappement Exhaust valve fork. Fourchette de rappel de tige Digger fork. Fourchette de tirage de levier de Brake rod fork. frein Fourchette porte-galet Exhaust roller fork. d'échappement Fourgon de livraison Large van. Fourré Bushed. Fourreau de fourche Fork blade. Franc-bord, à Carvel built. Frein Brake. Frein à bande Band brake. Frein à collier Band brake. _Frein à contre-pédalage_ _Back-pedalling brake._ Frein à enroulement Band brake. Frein à expansion Expansion brake. Frein à levier Lever brake. Frein à mâchoires Clasp brake; clip brake. Frein à patin Spoon brake. Frein à sabot Spoon brake. Frein à tambour Drum brake. Frein à vis Screw brake. _Frein du moyeu_ _Hub brake._ Frein sur jante Rim brake. Frein du différentiel Differential brake. Freiner To apply the brake. Frêne Ash. Frette Ferrule; nave hoop. Frottement Friction. Frottements à cônes Cone bearings. Fuite d'air Leakage of air. Fusée d'essieu Axle arm. G Gabarit Template. Gâche Staple. Gaïac Lignum vitæ. Gaine Case; sheath. Galerie Luggage guard. Galet Roller. Galet d'arbre à cames Cam shaft roller. Galet de chaîne Chain roller. Galet de débrayage Clutch lever roller. Galet de fourchette d'échappement Exhaust fork roller. Galet de friction Friction roller. Garage Garage; motor house. Garcette Gasket. Garde-boue Mudguard. Garde-boue arrière Back mudguard. Garde-boue avant Front mudguard. Garde-chaîne Chain guard; gear case. Garde-crotte Mudguard. _Garde-jupe_ _Dress guard._ Garni Upholstered; bushed. Garniture Lining; upholstering; packing. Gaz acétylène Acetylene gas. Gaz brûlé Burnt gas. Gaz de décharge } Exhaust gas. Gaz d'échappement } Générateur à vaporisation Flash boiler. instantanée Gerçure Boil; bulge on cover. Gicleur; gigleur Petrol jet. Glace Glass; window. Glace de couvercle de Commutator glass. distributeur d'allumage Glace de graisseur Lubricator glass. Glace du tiroir Face of slide valve. Glissement Slipping. Glissière Slide. Godet à huile Oil cup. Godet à pétrole Petrol cup. Gomme de Para Para rubber. Gonfler To inflate; to pump (tyres). Goujon Stud. Goujon de capote Head prop. Goujon d'inflammateur Sparking plug stud. Goujon de support de pompe Pump bracket stud. Goujon ergot Stud with projection. Goupille Pin. Goupille conique Taper pin. Goupille de bague de culbuteur Trip rod collar pin. Goupille de mise en marche Starting gear pin. Goupille fendue Split pin. Goupille filetée Threaded pin. Gousset Corner plate; gusset. Gouttières de graissage Oil ways. Grain Thrust block. Graissage Lubricator. Graisse Grease. Graisse consistante Stauffer grease; thick grease. Graisser To lubricate. Graisseur Lubricator. Graisseur à débit visible Sight feed lubricator. Graisseur à départs multiples Multiple lubricator. Graisseur compte-gouttes Drip feed lubricator. Graisseur coup de poing Hand pump lubricator. Graisseur de bâti Crank case lubricator. _Grand pignon_ _Chain wheel._ Grande route Public carriage road. Gravier Gravel. Grelot Bell. Griffe Dog. Grillage Grid. Grille anti-poussière } Gauze dust shield. Grille métallique } Grippement Friction; seizing. Gripper To seize. Groupe moteur Motor and gear. Guichet de prise d'air Air inlet flap or valve. Guide Guide. Guide de fourchette d'échappement Exhaust fork guide. Guide de frein Brake guide. Guide de soupape d'échappement Exhaust valve guide. _Guidon_ _Handle bar._ _Guidon cintré_ _Bent handle bar._ _Guidon réversible_ _Reversible handle bar._ H Haute tension High tension. Hayon Front or tail board of a wagon. Hélice Propeller. Hemlock Hemlock. Hernie Boil; bulge on cover. Hêtre Beech. Hickory Hickory. Horloge de voiture Carriage clock. Huilage Oiling. Huile Oil. Huile à graisser Lubricating oil. Huile de lin cuite Boiled linseed oil. Huile de pieds de boeuf Neat's foot oil. Huileur Oil hole. Huit Drop shackle. I If Yew. Imperforable Puncture proof. Imperméable à l'air Air tight. Indégonflable Non-deflatable. Indicateur de pentes Gradometer. Indicateur de pôles Pole finder. Indicateur de vitesse Speed indicator. Induit Armature. Inflammateur Sparking plug. Injecteur Injector. Insigne Badge. Interrupteur Switch. Interrupteur à cheville Connecting plug. _Interrupteur de cadre_ _Frame switch._ Isolateur Insulator. J Jante Rim. Jante creuse Hollow rim. Jante de la roue arrière Back rim. Jante de la roue avant Front rim. Jante en acier Steel rim. Jante en bois Wooden rim. Jauge Gauge. Jeu Play; clearance. Joint Joint. Joint à rotule Ball joint. Joint de Cardan Cardan joint. Jumelle Universal shackle. L Lacet Belt lace. Lâche Slack. Laiton Brass. Lame Small plate; blade. Lame à talon du rupteur Carpentier High speed trembler top plate. Lame de collier de frein ordinaire Segment of ordinary brake. Lame de maillon Side plate of link. Lame verte Green sheet. Laminage de la vapeur Wire drawing of steam. Lampe de brûleur Burner tank. Lampion Chinese lantern. Landau Landau. Landaulet Landaulet. Lanière Belt lace. Lanterne Lamp; burner cage; diaphragm. Lanterne à acétylène Acetylene lamp. Lanterne à bougie Candle lamp. Lanterne à huile Oil lamp. Lanterne à pétrole Petroleum lamp. Lanterne de queue Tail light. Largeur au maître-bau Beam. Lentille Lens (of lamp). Levier Lever. Levier à boule Ball lever. Levier à main Hand lever. Levier coudé Crank lever. Levier de changement de marche. Reversing lever. Levier de changement de vitesse. Change speed lever. Levier de débrayage Disengaging lever; clutch lever. Levier de direction Steering lever. Levier de frein Brake lever. Levier de ralentisseur Accelerator lever. Levier de régulateur Governor lever. Levier de tirage de frein Brake lever. Limande de garniture Gasket. Lime File. Limousine Limousine. Linguet Pawl. Linoleum Linoleum. Longeron Sole bar. Longueur de tête en tête Length between perpendiculars. Loquet Catch; latch. Loqueteau de portière Door lock. Lubrifiant Lubricant. Lubrifier To lubricate. Lumière d'échappement Exhaust port. Lunettes de route Goggles. M Macadam Macadam. Macaron Cork float. _Machine de route_ _Roadster._ Maillechort German silver. Maillon Link. Main de ressort Scroll iron. Main de support Support for spring. Manche Handle. Manchon Sleeve; socket. Manchon à griffes Dog clutch. Manchon excentrique de réduction. Offset reducing coupling. Manchon guêtre pour pneu Tyre gaiter. Manette Handle; hand lever. Manette à ressort Spring handle. Manette d'admission d'air Air lever. Manette d'admission de gaz Gas lever. Manette d'allumage Ignition lever. Manette d'avance à l'allumage Sparking advance lever. Manette de commande Controlling lever. Manette de compression Compression lever. Manivelle Crank; starting handle. Manivelle à cloche Bell crank. Manivelle de mise en marche Starting handle. Manivelle détachable Detachable crank. Manivelle droite Right crank. Manivelle gauche Left crank. Manneton Crank. Manomètre Pressure gauge. Marche Movement; motion. Marche arrière Reverse movement. Marche en avant Forward movement. Marchepied Step. Marchepied d'arrière Back step. Marchepied de côté Side step. Maroquin Morocco. Marteau Hammer. Masque Mask. Matière active Active material. Mèche Wick. Mélange Mixture; mixing. Mélange tonnant Explosive mixture. Mélèze Larch. Membrane Membrane. Membrures Boat frames. Menotte Shackle; dee shackle. Mentonnet Flange. Meuler To grind. Mine de plomb Blacklead. Mise en marche Starting. Modérateur Governor; regulator. Molleté Milled. Montant de porte Door pillar. Montée rapide Steep ascent. Montueux Hilly. Monture de brûleur Burner mount. Moteur Motor. Moteur à l'avant Motor in front. Moteur à quatre temps Four cycle gas motor. Moteur sous le siège Motor under the seat. _Motocycle_ _Motor cycle._ _Motocyclette_ _Motor bicycle._ _Motocycliste_ _Motor cyclist._ Mouvement de commande de Accelerator control gear. ralentisseur Mouvement de différentiel Differential gear; balance gear. Mouvement de réduction à 1/2 Two to one gear; half time gear. Moyeu Hub; boss. Moyeu de la roue arrière Rear hub. Moyeu de la roue avant Front hub. Multiplication Gear. Multiplication forte High gearing. Multiplier To gear up. N Nécessaire de réparations Repair outfit. Nickeler To plate. Noyau de fer Iron core. Noyer Walnut. O Obturateur Cap for oil hole. Obus Valve plug (tyre). Odomètre Odometer. OEuvre, dans l' In the clear. OEuvre, hors Over all. Omnibus Omnibus. Oreille Lug. Orifice d'échappement Exhaust opening. Orifice de remplissage Petrol inlet. Orme Elm. Orme blanc Grey elm. Orme noir Rock elm. Ornière Rut. P Palette de marchepied Step tread. Palier Bearing block. Palier central Centre bearing. Palier de butée Thrust bearing. Palier, en On the flat. Palissandre Rosewood. Panne Purlin; break-down. Panne, rester en To break down. Panneau Panel. Papier d'amiante Asbestos paper. Papier d'émeri Emery paper. Papier de verre Sand paper. Papillon Throttle valve; butterfly nut. Paraffine Paraffin. Pare-crotte Dash-board. Pare-flamme Flame guard. Pare-poussière Dust-guard. Pas de vis Pitch; thread of screw. Pastille pour réparation de pneu. Patch for repairing tyre. Pâte à polir Metal polish. Patin de frein Brake spoon or shoe. Patiner To skid. Patte d'attache Clamp. _Pattes arrière_ _End of back forks._ Pavé Cobble stones. Peau de vache Cowhide. Pédale Pedal. _Pédale à caoutchouc_ _Rubber pedal._ _Pédale à dents de scie_ _Rat-trap pedal._ Pédale à levier de débrayage Clutch pedal. _Pédale à scie_ _Rat-trap pedal._ Pédale au yatagan Clutch pedal. Pédale d'accélérateur Accelerator pedal. Pédale de débrayage Clutch pedal. Pédale de débrayage et frein Disengaging and brake pedal. Pédale de frein Brake pedal. Pédale de secteur d'accélérateur. Accelerator sector pedal. _Pédalier_ _Crank bracket_; _bottom bracket_. Pédalier Pedal gear. _Pédalier étroit_ _Narrow tread bracket._ Peinture aluminium Aluminium paint. Pente dure } Pente forte } Steep gradient. Pente raide } Pente douce } Easy gradient. Pente faible } Perforation Puncture. Perforer, se To puncture. Persienne Shutter. Pétrole lampant Paraffin; heavy oil. Pétrole lourd Heavy oil. Phaëton Phaeton. Phare Headlight. Pièce d'attache Clamp. Pièces de rechange Spare parts. Pièces interchangeables Interchangeable parts. Pièces mécaniques Working parts. Pièce polaire Pole piece. Pierre de rebord Kerbstone. Pignon Pinion. Pignon conique } Bevel wheel. Pignon d'angle } Pignon de chaîne Sprocket wheel. Pignon de dédoublement Gear wheel. _Pignon de la roue motrice_ _Rear hub chain ring._ Pignon de mise en marche } Starting pinion. Pignon de mise en train } Pignon droit Spur pinion. _Pignon, grand_ _Chain wheel._ Pile sèche Dry battery. _Pilier de selle_ _Saddle pillar._ Pin Pine. Pince Pliers. Pinçage Pinching (of tyre). Pincer To pinch. Piston Piston. Piston à air Air piston. Piston de carburateur Carburetter piston. Piston de moteur Motor piston. Pitch-pin Pitch pine. Piton Eye bolt. Pivot Pivot. Place Seat. Plan de détail Detailed plan. Plan de l'ensemble General plan. Plan de niveau Datum line. Plan vu de dessous Plan looking upwards. Planche de toiture Roof board. Planche du bout End board. Planche du siège Seat board. Planche latérale Side board. Planche pare-crotte Dash board; splash board. Planétaire Planetary. Plaque Plate. Plaqué argent Silver plated. Plaque de contrôle Tax plate. Plaque d'identité Identification plate. Plaque émaillée Enamelled plate. Plaque numérotée Number plate. Plat bord Gunwale. Plateau de friction Friction plate. Plateau de manivelle Crank disc. Plus-value Extra price. Pneu-cuir Tread. Pneumatique Tyre; cover. Pneumatique à talons Cover with beaded edges. Pneumatique à tringles Cover wired on. Pneumatique à tube simple Single tube tyre. Pneumatique auto-réparable Self sealing tyre. Pneumatique collé Single tube tyre. Pneumatique dégonflé Slack tyre. Pneumatique de la roue arrière. Back tyre. Pneumatique de la roue avant Front tyre. Poche à gaz Gas bag. Poche d'eau autour de la soupape Water receiver round exhaust d'échappement valve. Poignée Handle. _Poignée d'allumage du guidon_ _Handle bar switch._ Poignée de la pompe à huile Handle of oil pump. Poignée en corne Horn handle. Poignée en liège Cork handle. _Poignée tournante_ _Turning handle._ Point de repère Reference mark. Point mort Dead centre. Pointeau Needle valve. Pointeau d'arrivée d'essence Petrol inlet valve. Pointes de la bougie Points of sparking plug. Poire de cornette Bulb of horn. Pompe Pump. Pompe à air Air pump. Pompe à battant Pump with clapper valve. Pompe à étrier Stirrup pump. Pompe à huile Oil pump. Pompe à pied Foot pump. Pompe centrifuge Centrifugal pump. Pompe de circulation Circulation pump. Pompe pneumatique Tyre pump. Pompe rotative Rotary pump. Pompe télescope Telescopic pump. Pompe turbine Centrifugal pump; turbine pump. Poncelet 1 H.P. = 3/4 Poncelet. Porte Door. Porte à coulisse Sliding door. Porte-à-faux, arbre en Overhanging or projecting shaft. Porte-bagage Luggage carrier. Porte d'entourage Bonnet door. Porte-fusil Gun clip. Porte-lanterne Lamp bracket. Porte-montre Watch holder. Porte-phare Lamp bracket. Porte-pompe Pump clip. Portée de calage Axle seat. Portière Door. Portière latérale Side door. Pot d'échappement Exhaust box; exhaust pot; silencer. Poteau avertisseur Caution board. Poteau d'arrivée Winning post. Poteau indicateur Finger post. Poulie Pulley. Poulie de béquille Sprag pulley. Poulie de commande Driving pulley. Poulie de frein Brake pulley. Poulie de graisseur Lubricator pulley. Poulie de tension Jockey pulley. Poulie de transmission Driving pulley. Poulie étagée Step pulley. Poulie extensible Expanding pulley. Poulie jante Wheel pulley. Poulie motrice Driving pulley. Poussée Thrust. Poussée oblique Side thrust. Poussière Dust. Poussoir de soupape d'échappement. Exhaust valve lift. Poutre à treillis Lattice girder. Presse Clamp. Presse-étoupe Gland; stuffing box. Pression effective Working pressure. Prise d'air Air port; air inlet. Prise directe Direct drive. Propulseur Propeller. Protecteur Protector. Protecteur antidérapant à rivets. Studded tread band. Protecteur de bandage Protecting band for tyre. Puissance au frein Brake horse power. Purge Blow off. Purgeur continu Drip tap. Q _Quadricycle à moteur_ _Motor quadricycle._ Quadruplette Quadruplet. Quille Keel. Quinconces, en Staggered. R Raccord Union; pipe connection. Raccord d'aspiration Inlet valve union. Raccord de pompe Pump union. _Raccord du pilier de selle_ _Saddle lug_; _seat lug_. _Raccord inférieur avant_ _Bottom head cup._ Radiateur Radiator. Radiateur à alvéoles Honeycomb radiator. Radiateur cloisonné Sectional radiator. Radiateur multitubulaire Multitubular radiator. Radiateur nid d'abeilles Honeycomb radiator. Rafraîchir To cool. Rai Spoke. Rainure Groove. Ralentisseur; accélérateur Accelerator. Rallonge Extension piece. Rampe Guard. Rampe d'huile Oil-way. Rampe de sortie d'eau Inclined water outlet. Rampe, en On a gradient. Rangée de billes Ball race. Rappel, tige de Digger rod. Raté d'allumage Misfire. _Rattrape de pédale_ _Toe clip._ Rayon Spoke. Rayons directs Direct spokes. Rayons renforcés Butt ended spokes. Rayons renforcés aux deux bouts Double butted spokes. Rayons tangents Tangent spokes. Rebord de la fusée Collar. Recaoutchouture Re-tyring; re-rubbering. Recharge Refill. Réchauffeur Petrol warmer; warming pipe; feed heater. Rectifier To true. Recuire To anneal. Recuit Annealed. Réflecteur parabolique Parabolic reflector. Refoulement, tuyau de Delivery pipe. Refroidir To cool. Refroidissement à l'eau Water cooling. Refroidisseur Cooler. Refroidisseur nid d'abeilles Beehive cooler. Regard Inspection plate or cover. Réglage Adjustment. Réglement de circulation Regulations. Régulateur Governor; regulator. Régulateur à main fixé sur le Carburetter hand regulator. carburateur Rembourré Stuffed. Remiser une voiture To house a car. Remorquer To tow; to haul. Rendement du moteur Efficiency of motor. Renfort de fourche Prop for fork. _Repose-pied_ _Foot rest._ Réservoir Tank. Réservoir à eau Water tank. Réservoir à essence Petrol tank. Réservoir à flotteur Float chamber. Réservoir à huile Oil reservoir. Réservoir d'échappement Exhaust box. Réservoir de pétrole Petrol tank. Ressort Spring. Ressort à boudin Spiral spring. Ressort à pincette Elliptic spring. Ressort compensateur Compensating spring. Ressort d'appareil de commande Hand control spring. d'allumage Ressort de choc Buffer spring. Ressort d'embrayage Clutch spring. Ressort d'essieu Body spring. Ressort demi-pincette Grasshopper spring. Ressort de piston à air Diaphragm spring. Ressort de rappel Reaction spring. Ressort de rappel de distributeur Long commutator spring. Ressort de rappel de frein Brake spring. Ressort de rappel de levier de Carburetter lever spring. carburateur Ressort de rappel de tige Digger spring. Ressort de régulateur Governor spring. Ressort de soupape de robinet Petrol tap spring. Ressort de suspension Bearing spring. Ressort de tige de ralentisseur Accelerator rod spring. Ressort de trembleur Contact breaker spring. Ressort de vis pointeau des Burner valve spring. brûleurs Ressort elliptique Elliptic spring. Retard à l'allumage Retard sparking. Rideau Curtain. Ridelles Side timbers. Rivet Rivet. Robinet Tap. Robinet à deux voies Two-way tap. Robinet à trois débits pour Three-way water tap. circulation d'eau Robinet à trois voies Three-way tap. Robinet de compression Compression tap. Robinet de mélange Twin tap; mixing tap. Robinet de purge Blow through tap. Robinet de purge pour carburateur Waste petrol tap. Robinet de purge pour l'huile de Waste oil tap. graissage Robinet de réservoir Petrol tank tap. Robinet de tuyauterie à essence Petrol pipe tap. Robinet de vidange Drain tap. Robinet pour alimentation de Lubricator tap. graisseur Roder To grind. Rondelle Washer. Rondelle d'amiante Asbestos washer. Rondelle de pignon Sprocket wheel washer. Rondelle de réglage de pompe Pump washer. Rondelle Grover Split washer. Rondelle pour bossage de rais Spoke washer. Rotin Rattan. Rotule, joint à Globe joint; universal joint. Roulements à billes Ball bearings. Roue Wheel. Roue à ailettes pour pompe Pump fan. Roue à cliquet Ratchet wheel. Roue à gorge Grooved wheel. Roue d'angle Bevel wheel. Roue d'arrière Back wheel. Roue d'artillerie Artillery wheel. Roue d'avant Front wheel. Roue de chaîne Chain wheel. Roue de commande de graisseur Lubricator wheel. Roue de commande de marche Controlling wheel. Roue de régulateur Governor wheel. Roue de voiture Car wheel. Roue dentée Cog wheel. Roue directrice Steering wheel. Roue ferrée Iron tyred wheel. _Roue folle_ _Free wheel._ _Roue libre_ _Free wheel._ _Roue libre à billes_ _Ball bearing free wheel._ _Roue libre à cliquets_ _Free wheel, ratchet clutch._ _Roue libre à galets_ _Free wheel, roller clutch._ Roue motrice Driving wheel. _Roue motrice_ _Rear wheel._ Roue planétaire Planet wheel. Roue pleine Solid wheel. Roue quadruple Quadruple gear wheel. Roue triple Triple gear wheel. Roulant, très Easy running. Rouleau de chaîne Chain roller. Route Road. Route cahotante Bumpy road. Route carrossable Navigable road. Route défoncée Loose road. Route défoncée par le roulage Road broken up by traffic. Route de grande communication Turnpike road. Route départementale High road. Route en lacets Ribbon road; winding road. Route en pierres concassées Metalled road. Route nationale Main road. Route pavée Paved road. Route praticable Rideable road. _Routière_ _Roadster._ Rupteur Trembler; contact breaker. S Sabot Block. Sabot bois pour interrupteur Wooden switch block. Sabot de frein Brake spoon or shoe. Sabot forme cuiller Spoon block. Sac Bag. Sac en toile caoutchoutée Waterproof bag. Sacoche Tool bag. Sans-chaîne Chainless. Sapin Fir. Satellite Planetary member. Satin, bois de Satin wood. Schéma Diagram. Secours, boîte de Repair box. Secteur Sector; quadrant. Secteur denté Notched quadrant. Secteur de levier de ralentisseur Accelerator sector. Secteur pour avance à l'allumage Timing sector. Secteur pour direction Steering quadrant. Segment Segment. Segment de piston Piston ring. Selle Saddle. Semelle Sole piece. Série de fils Set of wires. Seringue Syringe. Seringue de graissage Grease injector. Serpentin Coil. _Serrage de selle_ _Saddle clip._ Serre-fil Wire clamp. Serre-rayon Spoke tightener. Serrer le frein To apply the brake. Sertisseur Tube expander. Siège Seat. Siège à coussins Cushioned seat. Siège ajustable Adjustable seat. Siège à ressorts Spring seat. Siège à tissu métallique Wire seat. Siège d'avant Front seat. Siège de bois Wooden seat. Siège de cuir Leather seat. Siège de soupape Valve seating. Siège en crin Hair seat. Siège fixe Fixed seat. Siège profond Well seat. Siège rembourré Stuffed seat. Siège tournant Revolving seat. Siège triple de soupape Triple inlet valve seat. d'aspiration Silencieux Exhaust box; silencer. Société Club. Socle Base. Soie de manivelle Crank pin. Sonnette Bell. Sortie Outlet. Soudé par rapprochement Butt welded. Soudé par recouvrement Lap welded. Soulèvement Lift. Soupape Valve. Soupape à air Air valve. Soupape à bille Ball valve. Soupape à papillon Butterfly valve; throttle valve. Soupape d'admission Inlet valve; induction valve. Soupape d'arrêt Stop valve. Soupape d'aspiration Inlet valve. Soupape de détente Cut-off valve. Soupape d'échappement Exhaust valve. Soupape de retenue Check valve. Soupape de sûreté Safety valve. Soupape de trop-plein Relief valve. Soupape en champignon Mushroom valve. Soupape en champignon renversé Cup valve. Soupape rotative Rotary valve. Spruce Spruce. Store Window blind. Strapontin Bracket seat; folding seat. Support Support. Support de pompe Pump bracket. Surchauffeur Superheater. Surface de refroidissement Cooling surface. Surface de roulement Tread. T Tablier Apron; length available for carriage work. Tablier d'arrière Tail board. Tablier d'avant Front apron; front board. Talc French chalk. Talon Beaded edge of tyre cover. Tambour Drum. Tambour de frein Brake drum. Tampon Plug; buffer. Tampon d'allumage Sparking plug. Tandem Tandem. Tandem à moteur Motor tandem. Tapis Carpet. Taquet de soulèvement de soupape Exhaust valve lifter. d'échappement Taraud Tap. Tasseau de bois Wood clamp; block. Té Tee. Teck Teak. Temps, à quatre Otto cycle. Temps d'aspiration Suction stroke. Temps de compression Compression stroke. Temps d'échappement Exhaust stroke. Temps d'explosion Explosion stroke. Tendeur Jockey pulley. Tendeur pour courroie Belt tightener. Tendre To tighten. Tenon Tenon; stud. Tension de chaîne Chain adjustment; _draw-link_. Térébenthine Turpentine. Tête Head; crown. Tête affleurée Flush head. Tête de bielle Connecting rod end. Tête de butoir Buffer head. _Tête de fourche avant_ _Front fork crown._ Tête fraisée Countersunk head. Tête noyée Countersunk head. Tête platinée Platinum tipped. Tétine Nipple. Thermosiphon Thermo syphon. Tiers-point Triangular file. Tige Rod; stem; spindle. Tige à fourchette Fork rod. Tige d'accélérateur Accelerator rod. Tige de butée de débrayage Rod for end of clutch shaft. Tige du cliquet de levier de Change speed lever rod. changement de vitesse Tige de distribution Slide rod. Tige d'excentrique Eccentric rod. Tige de flotteur Float wire. Tige de frein Brake rod. Tige de levier de frein Rod for brake lever. Tige de la pédale au yatagan Rod for clutch pedal. Tige de la soupape de compression Stem of compression valve. Tige de la soupape d'échappement Exhaust valve stem. Tige de piston Piston rod. Tige de poussoir d'échappement Exhaust valve lift rod. Tige de ralentisseur Accelerator rod. Tige de rappel de soupape Digger rod for exhaust valve. d'échappement _Tige de selle_ _Seat pillar._ Tige de soupape Valve spindle or stem. Tige de tirage de frein Brake rod. Tige entretoise Stay rod. Tige entretoise de culasse Rod for single cylinder. Timbre Bell. Tirant Stay. Tirant d'eau à vide Draught of water when empty. Tirant d'eau en charge Draught of water when loaded. _Tirant de la fourche arrière_ _Back fork bridge._ Tirant de radiateur Radiator stay. _Tirant des tubes montants_ _Mudguard bridge._ Tire-goupille Pin extractor. Tirette Prop. Tiroir Slide valve. Tiroir à coquille D valve. Toc Guide; tappet. Toc d'embrayage Guide for clutch cone. Toc de levier de régulateur Guide for governor lever. Toile Fabric (of tyre cover). Toile d'amiante Asbestos cloth. Toile d'émeri Emery cloth. Toile dissolutionnée Canvas for repairing cover. Toile gommée Canvas for repairing cover. Toile métallique Wire gauze. Toile treillis Ticking. Tôle Sheet of metal; sheet iron. Tôle emboutie Dished plate. Tôlerie Sheeting. Tonnant Explosive. Tonneau Tonneau. Tordre une roue To buckle a wheel. Torque Torque. Touche Interrupter plug; contact. Toucheau Contact piece. Tour d'adresse Feat of skill. Tour de force Feat of strength. Tournée Tour. Tournevis Screwdriver. Tourillon Journal; pivot. Tourillon de chaîne Rivet of chain. Tracteur Tractor. Train balladeur Balladeur train. Traits de force Shade lines. Transmission à Cardan Arbor shaft system of transmission. Trappe Flap door. Travail de cisaillement Shearing strain. Traverse Sole bar; beam. Trembleur Contact breaker; trembler. Trépidation Vibration. Tresse Gasket; braid. Tribune Stand. _Tricycle à chaîne centrale_ _Central gear tricycle._ _Tricycle à moteur_ _Motor tricycle._ _Tricycle à roue directrice _Front steerer tricycle._ devant_ _Tricycle compressible_ _Collapsible tricycle._ _Tricycle porteur_ _Carrier tricycle._ _Tricycle tandem_ _Tandem tricycle._ Tringle de changement de vitesse Change speed rod. Tringle de garde-boue Mudguard stay. Tringle de relevage Drag link. Tringles, à Wired on. Trottoir Footpath. Trottoir cyclable Cycle Path. Trou graisseur Oil hole. Trusquin à centrer Centering gauge. Tube Tube. Tube d'admission Induction pipe. Tube caoutchouc Rubber tube. Tube caoutchouc de valve Rubber sleeve of valve. Tube d'alimentation Gaspipe to motor; feed pipe. Tube d'arbre de l'hélice Stern tube. Tube d'échappement Exhaust pipe. Tube d'entrée d'air Air chimney. Tube de direction Steering column; _head socket_. Tube de frein Brake tube. _Tube de fourche arrière_ _Bottom stay._ Tube de la pompe à huile au moteur Oil pipe to crank case. Tube de niveau d'eau Water gauge glass. Tube de platine Platinum tube. Tube de prise d'air Air inlet pipe. Tube de trop-plein Overflow pipe. _Tube diagonal_ _Diagonal tube._ Tube du carburateur à la boîte de Pipe from carburetter to mixing mélange chamber. _Tube inférieur_ _Bottom tube._ _Tube intérieur de direction_ _Steering post._ Tube mélangeur Mixing tube. _Tube montant arrière_ _Back stay._ Tube pare-poussière Dust cap tube. _Tube plongeur du guidon_ _Handle bar stem._ Tube renforcé Extra strong tube. Tube sans soudure Seamless tube. _Tube supérieur_ _Top tube._ Tube tirant Stay tube. Tubulure Nozzle; connection. Tuyau Pipe. Tuyauterie Tubing. Tuyauterie d'aspiration Suction tubing. Tuyauterie d'échappement Exhaust tubing. Tuyère Nozzle. Tuyère de carburateur Air nozzle for carburetter. U Usine Factory. Usure Wear and tear. V Valve Valve. Vapeur de décharge Exhaust steam. Vaporisateur à pulvérisation Spray vaporiser. Vaporisation Steam production. Véhicule Vehicle. _Vélocipède_; _vélo_ _Cycle._ Ventilateur Ventilator; fan. Vérin Jack. Vernir To japan. Verre Glass. Verrou Catch; bolt. Verrou d'entourage Catch for bonnet door. Verrou de levier de changement de Catch for change speed lever. vitesse Verrou de mise en marche Starting catch or bolt. Victoria Victoria. Vilebrequin Crank; crank shaft. Virole Ferrule. Vis Screw. Vis à filet droit Right handed screw. Vis à filet gauche Left handed screw. Vis bouchon de purge Run off screw. Vis d'axe de piston Screw for piston pin. Vis de butée du rupteur Carpentier Screw for high speed trembler blade. Vis de came de moteur Screw for governor cam. Vis de clavetage de la douille de Screw for starting pin or bush. mise en marche Vis de collier de trompette Screw for horn bracket. Vis de contact Contact screw. Vis de couvercle de carburateur Screw for carburetter cover. Vis de fixation Fixing screw. Vis de fixation de la vis de Screw for fastening platinum contact tipped screw. Vis de marteau de came Governor hammer screw. Vis de mécanique Brake screw. Vis de poussée Thrust screw. Vis de purge pour carburateur Waste petrol screw. Vis de purge pour l'huile de Waste oil screw. graissage Vis de rappel Setscrew. Vis de réglage Setscrew. Vis de sûreté Setscrew. Vis fixant la lame platinée à Screw for high speed trembler top talon du rupteur Carpentier plate. Vis graisseur pour chapeau Lubricator screw for wheel cap. d'essieu Vis platinée de contact Platinum tipped screw. Vis pointeau de lampe de brûleur Screw tap for burner tank. Vis pointeau de support de brûleur Screw tap for burner. Vis pour direction Screw for steering. Vis pour ralentisseur Screw for accelerator. Vis sans fin Worm. Visiter To examine. Visser To screw. Vitesse en prise directe, grande Direct drive on top speed. Voie Road. Voie impraticable Bad road. Voie légère Light railway. Voilée, roue Buckled wheel. Voiture Car. Voiture courante Ordinary car. Voiture de course Racing car. Voiture de livraison Parcels van. Voiture de tourisme Touring car. Voiture légère Light vehicle. Voiture lourde Heavy vehicle. Voiturette Runabout. Voiturette remorque Trailer. Volant Fly-wheel; hand wheel. Volant à gorge Grooved wheel. Volant de direction Steering wheel. Volant de dynamo Dynamo wheel. Volant de pompe Pump wheel. Volant de régulateur Governor wheel. Volet Shutter. Voltmètre Voltmeter. Vrac, en In bulk. W Wagonnette Wagonette. Y Yatagan Clutch lever. Yeuse Live oak. Z Zinc Zinc. LONDON: PRINTED BY WILLIAM CLOWES AND SONS, LIMITED, GREAT WINDMILL STREET, W., AND DUKE STREET, STAMFORD STREET, S.E. * * * * * _SHORT LIST_ _August 1912_ A SHORT LIST OF SCIENTIFIC BOOKS PUBLISHED BY E. & F. N. SPON, Limited, 57 Haymarket, London, S.W. SOLE ENGLISH AGENTS for the Books of-- MYRON C. CLARK, NEW YORK SPON & CHAMBERLAIN, NEW YORK PAGE AGRICULTURE 2 ARCHITECTURE 2 ARTILLERY 5 AVIATION 5 BRIDGES AND ROOFS 6 BUILDING 2 CEMENT AND CONCRETE 7 CIVIL ENGINEERING 9 CURVE TABLES 12 DICTIONARIES 13 DOMESTIC ECONOMY 13 DRAWING 14 EARTHWORK 15 ELECTRICAL ENGINEERING 15 FOREIGN EXCHANGE 21 GAS AND OIL ENGINES 21 GAS LIGHTING 22 HISTORICAL; BIOGRAPHICAL 23 HOROLOGY 23 HYDRAULICS 24 INDUSTRIAL CHEMISTRY 25 INSTITUTIONS 56 INTEREST TABLES 28 IRRIGATION 28 LOGARITHM TABLES 29 MANUFACTURES 25 MARINE ENGINEERING 29 MATERIALS 31 MATHEMATICS 32 MECHANICAL ENGINEERING 34 METALLURGY 37 METRIC TABLES 38 MINERALOGY AND MINING 39 MISCELLANEOUS 55 MODEL MAKING 41 MUNICIPAL ENGINEERING 46 NAVAL ARCHITECTURE 29 ORGANISATION 41 PHYSICS 42 PRICE BOOKS 43 RAILWAY ENGINEERING 44 SANITATION 46 STRUCTURAL DESIGN 6 TELEGRAPH CODES 48 USEFUL TABLES 53 WARMING; VENTILATION 48 WATER SUPPLY 49 WORKSHOP PRACTICE 50 ALL BOOKS ARE BOUND IN CLOTH UNLESS OTHERWISE STATED. _NOTE: The Prices in this Catalogue apply to books sold in the United Kingdom only._ AGRICULTURE. =Hemp.= A Practical Treatise on the Culture for Seed and Fibre. By S. S. BOYCE. 13 illus. 112 pp. crown 8vo. (_New York, 1900_) _net_ 2 0 =Farm Drainage.= By H. F. FRENCH. 100 illus. 284 pp. crown 8vo. (_New York, 1904_) _net_ 4 6 =Spices and How to Know Them.= By W. M. GIBBS. With 47 plates, including 14 in colours, 179 pp. 8vo. (_New York, 1909_) _net_ 15 0 =Talks on Manures.= By J. HARRIS. New edition, 366 pp. crown 8vo. (_New York, 1893_) _net_ 6 6 =Coffee=, its Culture and Commerce in all Countries. By C. G. W. LOCK. 11 plates, 274 pp. crown 8vo. (_1888_) 12 6 =Sugar, a Handbook for Planters and Refiners.= By the late J. A. R. NEWLANDS and B. E. R. NEWLANDS. 236 illus. 876 pp. demy 8vo. (_1909_) _net_ 1 5 0 =Hops=, their Cultivation, Commerce and Uses. By P. L. SIMMONDS. 143 pp. crown 8vo. (_1877_) 4 6 =Estate Fences=, their Choice, Construction and Cost. By A. VERNON. Re-issue, 150 illus. 420 pp. 8vo. (_1909_) _net_ 8 6 ARCHITECTURE AND BUILDING. =Engineering Work in Public Buildings.= By R. O. ALLSOP. 77 illus. 168 pp. demy 4to. (_1912_) _net_ 12 6 =The Hydropathic Establishment and its Baths.= By R. O. ALLSOP. 8 plates, 107 pp. demy 8vo. (_1891_) 5 0 =The Turkish Bath=, its Design and Construction. By R. O. ALLSOP. 27 illus. 152 pp. demy 8vo. (_1890_) 6 0 =Public Abattoirs=, their Planning, Design and Equipment. By R. S. AYLING. 33 plates, 100 pp. demy 4to. (_1908_) _net_ 8 6 =The Builder's Clerk.= By T. BALES. Second edition, 92 pp. fcap. 8vo. (_1904_) 1 6 =Glossary of Technical Terms= used in Architecture and the Building Trades. By G. J. BURNS. 136 pp. crown 8vo. (_1895_) 3 6 =Chimney Design and Theory.= By W. W. CHRISTIE. Second edition, 54 illus. 200 pp. crown 8vo. (_New York, 1902_) _net_ 12 6 =Approximate Estimates.= By T. E. COLEMAN. Third ed. 481 pp. ob. 32mo, leather. (_1907_) _net_ 5 0 =Stable Sanitation and Construction.= By T. E. COLEMAN. 183 illus. 226 pp. crown 8vo. (_1897_) 6 0 =House Plans= and Building Construction for General Contractors and House Builders. By M. M. DUSTMAN. 511 illus. 239 pp. oblong folio. (_New York, 1912_) _net_ 8 6 =Architectural Examples= in Brick, Stone, Wood and Iron. By W. FULLERTON. Third edition 245 plates, 254 pp. demy 4to. (_1908_) _net_ 15 0 =Bricklaying System.= By F. B. GILBRETH. 240 illus. 321 pp. 8vo. (_New York, 1909_) _net_ 12 6 =Field System.= By F. B. GILBRETH. 194 pp. 12mo. leather. (_New York, 1908_) _net_ 12 6 =The Building Trades Pocket Book.= Compiled by R. HALL. 12mo. With diary _net_ 1 0 =The Economics of Contracting.= By D. J. HAUER. 10 illus. viii. + 269 pp. crown 8vo. (_New York, 1911_) _net_ 12 0 =The Clerk of Works' Vade Mecum.= By G. G. HOSKINS. Seventh edition, 52 pp. fcap. 8vo. (_1901_) 1 6 =Paint and Colour Mixing.= By A. S. JENNINGS. Fourth ed. 14 col. plates, 190 pp. 8vo. (_1910_) _net_ 5 0 =A Handbook of Formulæ, Tables, and Memoranda for Architectural Surveyors.= By J. T. HURST. Fifteenth edition, 512 pp. royal 32mo, roan. (_1905_) _net_ 5 0 =Quantity Surveying.= By J. LEANING. Fifth ed. new impression, 936 pp. 8vo. (_1912_) _net_ 1 5 0 =Builders' Quantities.= By H. M. LEWIS. 6 illus. 44 pp. cr. 8vo. (S. & C. SERIES No. 40.) (_1911_) _net_ 1 6 =Obstruction to Light.= A Graphic Method of determining Problems of Ancient Lights. By H. B. MOLESWORTH. 9 folding plates, 4to. (_1902_) _net_ 6 0 =Suburban Houses.= A series of practical plans. By J. H. PEARSON. 46 plates and 12 pp. text, crown 4to. (_1905_) _net_ 7 6 =Solid Bitumens=, their Physical and Chemical Properties. By S. F. PECKHAM. 23 illus. 324 pp. 8vo. (_New York, 1909_) 1 1 0 =Roman Architecture, Sculpture and Ornament.= By G. B. PIRANESI. 200 plates, reproduced in facsimile from the original. 2 vols. imperial folio, in wrappers. (_1900_) _net_ 2 2 0 =The Seven Periods of English Architecture=, defined and illustrated. By E. SHARPE. Third edition, 20 steel plates, royal 8vo. (_1888_) 12 6 =Our Factories, Workshops and Warehouses=, their Sanitary and Fire-Resisting Arrangements. By B. H. THWAITE. 183 ill. 282 pp. cr. 8vo. (_1882_) 9 0 =Elementary Principles of Carpentry.= By T. TREDGOLD AND J. T. HURST. Eleventh edition, 48 plates, 517 pp. crown 8vo. (_1904_) 12 6 =Treatise on the Design and Construction of Mill Buildings.= By W. G. TYRRELL. 652 illus. 490 pp. demy 8vo. (_New York, 1911_) _net_ 17 0 =Practical Stair Building and Handrailing.= By W. H. WOOD. 32 plates, 91 pp. crown 4to. (_1894_) 10 6 =Spons' Architects' and Builders' Pocket Price-Book, Memoranda, Tables and Prices.= Edited by CLYDE YOUNG. Revised by STANFORD M. BROOKS. 16mo, leather cloth (size 6-1/2 in. by 3-3/4 in. by 1/2 in. thick). Issued annually in two Sections. =Prices and Diary=, in green cover, 239 pp. with Diary showing a week at an opening _net_ 2 6 =Memoranda and Tables=, in red cover. Illustrated, 372 pp. _net_ 2 6 ARTILLERY. =Guns and Gun Making Material.= By G. EDE. Crown 8vo. (_1889_) 6 0 =Treatise on Application of Wire to Construction of Ordnance.= By J. A. LONGRIDGE. 180 pp. 8vo. (_1884_) 1 5 0 =The Progress of Artillery: Naval Guns.= By J. A. LONGRIDGE. 8vo, sewed. (_1896_) 2 0 =The Field Gun of the Future.= By J. A. LONGRIDGE. 8vo, sewed. (_1892_) 2 6 AVIATION. =The Atmosphere=: its characteristics and dynamics. By F. J. B. CORDEIRO. 35 illus. 129 pp. small quarto. (_New York, 1910_) _net_ 10 6 =Theory and Practice of Model Aeroplaning.= By V. E. JOHNSON. 61 illus. 150 pp. crown 8vo. (_1910_) _net_ 3 6 =The Gyroscope, An Experimental Study.= By V. E. JOHNSON. 34 illus. 40 pp. crown 8vo. (S. & C. SERIES, No. 22.) (_1911_) _net_ 1 6 =Natural Stability and the Parachute Principle in Aeroplanes.= By W. LE MAITRE. 34 ill. 48 pp. cr. 8vo. (S. & C. SERIES No. 39.) (_1911_) _net_ 1 6 =How to Build a 20-ft. Bi-plane Glider.= By A. P. MORGAN. 31 illus. 60 pp. crown 8vo. (S. & C. SERIES, No. 14.) (_New York, 1909_) _net_ 1 6 =Flight-Velocity.= By A. SAMUELSON. 4 plates, 42 pp. 8vo, sewed. (_1906_) _net_ 2 0 =Resistance of Air and the Question of Flying.= By A. SAMUELSON. 23 illus. 36 pp. 8vo, sewed. (_1905_) _net_ 2 0 =Aeroplanes in Gusts, Soaring Flight and Aeroplane Stability.= By S. L. WALKDEN. Demy 8vo. (_In the Press._) BRIDGES, ARCHES, ROOFS, AND STRUCTURAL DESIGN. =Strains in Ironwork.= By HENRY ADAMS. Fourth edition, 8 plates, 65 pp. crown 8vo. (_1904_) 5 0 =Designing Ironwork.= By HENRY ADAMS. Second series. 8vo, sewed. Part I. A Steel Box Girder. (_1894_) _net_ 0 9 " II. Built-up Steel Stanchions. (_1901_) _net_ 1 3 " III. Cisterns and Tanks. (_1902_) _net_ 1 0 " IV. A Fireproof Floor. (_1903_) _net_ 1 0 =Columns and Struts.= Theory and Design. By WM. ALEXANDER. 101 illus. xii + 265 pp. demy 8vo. (_1912_) _net_ 10 6 =A Practical Treatise on Segmental and Elliptical Oblique or Skew Arches.= By G. J. BELL. Second edition, 17 plates, 125 pp. royal 8vo. (_1906_) _net_ 1 1 0 =Economics of Construction= in relation to Framed Structures. By R. H. BOW. Third thousand, 16 plates, 88 pp. 8vo. (_1873_) 5 0 =Theory of Voussoir Arches.= By Prof. W. CAIN. Third edition, 201 pp. 18mo, boards. (_New York, 1905_) _net_ 2 0 =New Formulæ for the Loads and Deflections= of Solid Beams and Girders. By W. DONALDSON. Second edition, 8vo. (_1872_) 4 6 =Plate Girder Railway Bridges.= By M. FITZMAURICE. 4 plates, 104 pp. 8vo. (_1895_) 6 0 =Pocket Book of Calculations= in Stresses. By E. M. GEORGE. 66 illus. 140 pp. royal 32mo, half roan. (_1895_) 3 6 =Strains on Braced Iron Arches= and Arched Iron Bridges. By A. S. HEAFORD. 39 pp. 8vo. (_1883_) 6 0 =Tables for Roof Framing.= By G. D. INSKIP. Second edition, 451 pp. 8vo, leather. (_New York, 1905_) _net_ 12 6 =Stresses in Girder and Roof Frames=, for both dead and live loads, by simple Multiplication, etc. By F. R. JOHNSON. 28 plates, 215 pp. crown 8vo. (_1894_) 6 0 =A Graphical Method for Swing Bridges.= By B. F. LA RUE. 4 plates, 104 pp. 18mo, boards. (_New York, 1892_) _net_ 2 0 =Bridge and Tunnel Centres.= By J. B. MCMASTERS. Illustrated, 106 pp. 18mo, boards. (_New York, 1893_) _net_ 2 0 =Notes on Cylinder Bridge Piers= and the Well System of Foundations. By J. NEWMAN. 144 pp. 8vo. (_1893_) 6 0 =Calculation of Columns.= By T. NIELSEN. 4 plates, 36 pp. 8vo. cloth. (_1911_) _net_ 4 6 =A New Method of Graphic Statics= applied in the Construction of Wrought Iron Girders. By E. OLANDER. 16 plates, small folio. (_1887_) 10 6 =Steel Bar and Plate Tables.= Giving Weight of a Lineal Foot of all sizes of =L= and =T= Bars, Flat Bars, Plates, Square and Round Bars. By E. READ. On large folding card. (_1911_) _net_ 1 0 =Reference Book for Statical Calculations.= By F. RUFF. With diagrams, 140 pp. crown 8vo. (_1906_) _net_ 5 0 =Suspension Bridges and Cantilevers.= By D. B. STEINMANN. vii. + 185 pp. 18mo, boards. (VAN NOSTRAND SERIES, No. 127.) (_New York, 1911_) _net_ 2 0 =The Strength and Proportion of Riveted Joints.= By B. B. STONEY. 87 pp. 8vo. (_1885_) 5 0 =The Anatomy of Bridgework.= By W. H. THORPE. 103 illus. 190 pp. crown 8vo. (_1906_) _net_ 6 0 CEMENT AND CONCRETE. =Portland Cement=: its Manufacture, Testing and Use, By D. B. BUTLER. Second edition, 97 illus. 396 pp. demy 8vo. (_1905_) _net_ 16 0 =Theory of Steel-Concrete Arches= and of Vaulted Structures. By W. CAIN. Fourth edition, 27 illus. 212 pp. 18mo, boards. (_New York, 1906_) _net_ 2 0 =Reinforced Concrete Construction. Elementary Course.= By M. T. CANTELL. 65 illus. 135 pp. crown 8vo. (_1911._) _net_ 4 6 =Reinforced Concrete Construction. Advanced Course.= By M. T. CANTELL. 242 illus. xvi + 240 pp. super-royal 8vo. (_1912_) _net_ 12 6 =Graphical Reinforced Concrete Design.= A series of Diagrams on sheets (measuring 17-1/2 in. by 22-1/2 in.) for Designing and Checking. With 48-page pamphlet. By J. A. DAVENPORT. Complete in roll. (_1911_) _net_ 5 0 =Cement Users' and Buyers' Guide.= By CALCARE. 115 pp. 32mo, cloth. (_1901_) _net_ 1 6 =Diagrams for Designing Reinforced Concrete Structures.= By G. F. DODGE. 31 illus. 104 pp. oblong folio. (_New York, 1910_) _net_ 17 0 =Cements, Mortars, and Concretes=; their Physical properties. By M. S. FALK. 78 illus. 176 pp. 8vo. (_New York, 1904_) _net_ 10 6 =Concrete Construction, Methods and Cost.= By H. P. GILLETTE and C. S. HILL. 310 illus. 690 pp. 8vo. (_New York, 1908_) _net_ 1 1 0 =Engineers' Pocket-Book of Reinforced Concrete.= By E. L. HEIDENREICH. 164 illus. 364 pp. crown 8vo, leather, gilt edges. (_New York, 1909_) _net_ 12 6 =Concrete Inspection.= By C. S. HILL. 15 illus. 179 pp. 12mo. (_New York, 1909_) _net_ 4 6 =Practical Silo Construction.= By A. A. HOUGHTON. 18 illus. 69 pp. crown 8vo. (S. & C. SERIES, No. 27.) (_New York, 1911_) _net_ 1 6 =Molding Concrete Chimneys, Slate and Roof Tiles.= By A. A. HOUGHTON. 15 illus. 61 pp. crown 8vo. (S. & C. SERIES, No. 28.) (_New York, 1911_) _net_ 1 6 =Molding and Curing Ornamental Concrete.= By A. A. HOUGHTON. 5 illus. 58 pp. crown 8vo. (S. & C. SERIES, No. 29.) (_New York, 1911_) _net_ 1 6 =Concrete Monuments, Mausoleums and Burial Vaults.= By A. A. HOUGHTON. 18 illus. 65 pp. crown 8vo. (S. & C. SERIES, No. 31.) (_New York, 1911_) _net_ 1 6 =Concrete Floors and Sidewalks.= By A. A. HOUGHTON. 8 illus. 63 pp. crown 8vo. (S. & C. SERIES, No. 32.) (_New York, 1911_) _net_ 1 6 =Molding Concrete Baths, Tubs, Aquariums and Natatoriums.= By A. A. HOUGHTON. 16 illus. 64 pp. crown 8vo. (S. & C. SERIES, No. 33.) (_New York, 1911_) _net_ 1 6 =Concrete Bridges, Culverts and Sewers.= By A. A. HOUGHTON. 14 illus. 58 pp. crown 8vo. (S. & C. SERIES, No. 34.) (_New York, 1912_) _net_ 1 6 =Constructing Concrete Porches.= By A. A. HOUGHTON. 18 illus. 62 pp. crown 8vo. (S. & C. SERIES, No. 35.) _net_ 1 6 =Molding Concrete Flower-Pots, Boxes, Jardinières=, etc. By A. A. HOUGHTON. 8 illus. 52 pp. crown 8vo. (S. & C. SERIES, No. 36.) (_New York, 1912_) _net_ 1 6 =Molding Concrete Fountains and Lawn Ornaments.= By A. A. HOUGHTON. 14 illus. 56 pp. crown 8vo. (S. & C. SERIES, No. 37). (_New York, 1912_) _net_ 1 6 =Reinforced Concrete.= By E. MCCULLOCH. 28 illus. 128 pp. crown 8vo. (_New York, 1908_) _net_ 6 6 =Concrete and Reinforced Concrete.= By H. A. REID. 715 illus. 884 pp. royal 8vo. (_New York, 1907_) _net_ 21 0 =Theory and Design of Reinforced Concrete Arches.= By A. REUTERDAHL. 41 illus. 126 pp. 8vo. (_New York, 1908_) _net_ 8 6 =Specification for Concrete Flags.= Issued by the INSTITUTION OF MUNICIPAL AND COUNTY ENGINEERS. Folio, sewed. (_1911_) _net_ 2 6 =Practical Cement Testing.= By W. P. TAYLOR. With 142 illus. 329 pp. demy 8vo. (_New York, 1906_) _net_ 12 6 =Concrete Bridges and Culverts.= By H. G. TYRRELL. 66 illus. 251 pp. cr. 8vo, leather. _net_ 12 6 CIVIL ENGINEERING. CANALS, SURVEYING. (_See also_ IRRIGATION _and_ WATER SUPPLY.) =Practical Hints to Young Engineers Employed on Indian Railways.= By A. W. C. ADDIS. With 14 illus. 154 pp. 12mo. (_1910_) _net_ 3 6 =Levelling=, Barometric, Trigonometric and Spirit. By I. O. BAKER. Second edition, 15 illus. 145 pp. 18mo, boards. (_New York, 1903_) _net_ 2 0 =Punjab Rivers and Works.= By E. S. BELLASIS. 47 illus. 85 pp. folio, cloth. (_1911_) _net_ 8 0 =Notes on Instruments= best suited for Engineering Field Work in India and the Colonies. By W. G. BLIGH. 65 illus. 218 pp. 8vo. (_1899_) 7 6 =Practical Designing of Retaining Walls.= By Prof. W. CAIN. Fifth edition, 14 illus. 172 pp. 18mo, boards. (_New York, 1908_) _net_ 2 0 =Land Area Tables.= By W. CODD. Sheet mounted on linen, in cloth case, with explanatory booklet 3 6 =The Maintenance of Macadamised Roads.= By T. CODRINGTON. Second ed., 186 pp. 8vo. (_1892_) 7 6 =The Civil Engineers' Cost Book.= By MAJOR T. E. COLEMAN, R.E. xii. + 289 pp. Pocket size (6-1/2 in. × 3-5/8 in.), leather cloth. (_1912_) _net_ 5 0 =Retaining Walls in Theory and Practice.= By T. E. COLEMAN. 104 ill. 160 pp. cr. 8vo. (_1909_) _net_ 5 0 =On Curved Masonry Dams.= By W. B. COVENTRY. 8vo, sewed. (_1894_) 2 0 =A Practical Method of Determining the Profile of a Masonry Dam.= By W. B. COVENTRY. 8vo, sewed. (_1894_) 2 6 =The Stresses on Masonry Dams= (oblique sections). By W. B. COVENTRY. 8vo, sewed. (_1894_) 2 0 =Handbook of Cost Data for Contractors and Engineers.= By H. P. GILLETTE. 1854 pp. crown 8vo, leather, gilt edges. (_New York, 1910_) _net_ 1 1 0 =Rock Excavation, Methods and Cost.= By H. P. GILLETTE. _New edition in preparation._ =High Masonry Dams.= By E. S. GOULD. With illus. 88 pp. 18mo, boards. (_New York, 1897_) _net_ 2 0 =Railway Tunnelling= in Heavy Ground. By C. GRIPPER. 3 plates, 66 pp. royal 8vo. (_1879_) 7 6 =Levelling and its General Application.= By T. HOLLOWAY. (_Third edition in preparation_) =Waterways and Water Transport.= By J. S. JEANS. 55 illus. 520 pp. 8vo. (_1890_) _net_ 9 0 =Table of Barometrical Heights to 20,000 Feet.= By LT.-COL. W. H. MACKESY. 1 plate, 24 pp. royal 32mo. (_1882_) 3 0 =Aid Book to Engineering Enterprise.= By E. MATHESON. Third edition, illustrated, 916 pp. medium 8vo, buckram. (_1898_) 1 4 0 =A Treatise on Surveying.= By R. E. MIDDLETON and O. CHADWICK. Third edition, royal 8vo. (_1911_) Part I. 11 plates 162 illus. 285 pp. 10 6 " II. 152 illus. and 2 plates, 340 pp. 10 6 =A Pocket Book of Useful Formulæ and Memoranda=, for Civil and Mechanical Engineers. By Sir G. L. MOLESWORTH and H. B. MOLESWORTH. With an Electrical Supplement by W. H. MOLESWORTH. Twenty-sixth edition, 760 illus. 901 pp. royal 32mo, French morocco, gilt edges. (_1908_) _net_ 5 0 =The Pocket Books of Sir G. L. Molesworth and J. T. Hurst=, printed on India paper and bound in one vol. Royal 32mo, russia, gilt edges _net_ 10 6 =Metallic Structures: Corrosion and Fouling and their Prevention.= By J. NEWMAN. Illustrated, 385 pp. crown 8vo. (_1896_) 9 0 =Scamping Tricks and Odd Knowledge= occasionally practised upon Public Works. By J. NEWMAN. New imp., 129 pp. cr. 8vo. (_1908_) _net_ 2 0 =Co-ordinate Geometry= applied to Land Surveying. By W. PILKINGTON. 5 illus. 44 pp. 12mo. (_1909_) _net_ 1 6 =Pioneering.= By F. SHELFORD. Illustrated, 88 pp. crown 8vo. (_1909_) _net_ 3 0 =Topographical Surveying.= By G. J. SPECHT. Second edition, 2 plates and 28 illus. 210 pp. 18mo, boards. (_New York, 1898_) _net_ 2 0 =Spons' Dictionary of Engineering=, Civil, Mechanical, Military and Naval. 10,000 illus. 4300 pp. super royal 8vo. (_1874, Supplement issued in 1881_). Complete, in 4 vols. _net_ 3 3 0 =Surveying and Levelling Instruments.= By W. F. STANLEY. (_Fourth edition in preparation_) =Surveyor's Handbook.= By T. U. TAYLOR. 116 illus. 310 pp. crown 8vo, leather, gilt edges. (_New York, 1908_) _net_ 8 6 =Logarithmic Land Measurement.= By J. WALLACE. 32 pp. royal 8vo. (_1910_) _net_ 5 0 =The Drainage of Fens and Low Lands= by Gravitation and Steam Power. By W. H. WHEELER. 8 plates, 175 pp. 8vo. (_1888_) 12 6 =Stadia Surveying=, the theory of Stadia Measurements. By A. WINSLOW. Fifth edition, 148 pp. 18mo, boards. (_New York, 1902_) _net_ 2 0 =Handbook on Tacheometrical Surveying.= By C. XYDIS. 55 illus. 3 plates, 63 pp. 8vo. (_1909_) _net_ 6 0 CURVE TABLES. =Grace's Tables for Curves=, with hints to young engineers. 8 figures, 43 pp. oblong 8vo. (_1908_) _net_ 5 0 =Railroad Curves and Earthwork.= By C. F. ALLEN. Third edition, 4 plates, 198 pp. 12mo, leather, gilt edges. (_New York, 1908_) _net_ 8 6 =Data relating to Railway Curves and Superelevations=, shown graphically. By J. H. HAISTE. On folding card for pocket use _net_ 0 6 =Tables for setting-out Railway Curves.= By C. P. HOGG. A series of cards in neat cloth case 4 6 =Tables for setting out Curves= for Railways, Roads, Canals, etc. By A. KENNEDY and R. W. HACKWOOD. 32mo _net_ 2 0 =Spiral Tables.= By J. G. SULLIVAN. 47 pp. 12mo, leather. (_New York, 1908_) _net_ 6 6 =Tables for Setting out Curves= from 101 to 5000 feet radius. By H. A. CUTLER and F. J. EDGE. Royal 32mo _net_ 2 0 =Tables of Parabolic Curves= for the use of Railway Engineers and others. By G. T. ALLEN. Fcap. 16mo 4 0 =Transition Curves.= By W. G. FOX. 18mo, boards. (_New York_) _net_ 2 0 DICTIONARIES. =Technological Dictionary in the English, Spanish, German and French Languages.= By D. CARLOS HUELIN Y ARSSU. Crown 8vo. Vol. I. ENGLISH-SPANISH-GERMAN-FRENCH. 609 pp. (_1906_) _net_ 10 6 Vol. II. GERMAN-ENGLISH-FRENCH-SPANISH. 720 pp. (_1908_) _net_ 10 6 Vol. III. FRENCH-GERMAN-SPANISH-ENGLISH. _In preparation._ Vol. IV. SPANISH-FRENCH-ENGLISH-GERMAN. 750 pp. (_1910_) _net_ 10 6 =Dictionary of English and Spanish Technical and Commercial Terms.= By W. JACKSON. 164 pp. fcap. 8vo. (_1911_) _net_ 2 6 =English-French and French-English Dictionary of the Motor-Car, Cycle and Boat.= By F. LUCAS. 171 pp. crown 8vo. (_1905_) _net_ 2 0 =Spanish-English Dictionary of Mining Terms.= By F. LUCAS. 78 pp. 8vo.(_1905_) _net_ 5 0 =English-Russian and Russian-English Engineering Dictionary.= By L. MEYCLIAR. 100 pp. 16mo. (_1909_) _net_ 2 6 DOMESTIC ECONOMY. =Food Adulteration and its Detection.= By J. P. BATTERSHALL. 12 plates, 328 pp. demy 8vo. (_New York, 1887_) 15 0 =Practical Hints on Taking a House.= By H. P. BOULNOIS. 71 pp. 18mo. (_1885_) 1 6 =The Cooking Range=, its Failings and Remedies. By F. DYE. 52 pp. fcap. 8vo, sewed. (_1888_) 0 6 =Spices and How to Know Them.= By W. M. GIBBS. With 47 plates, including 14 in colours, 179 pp. 8vo. (_New York, 1909_) _net_ 15 0 =The Kitchen Boiler and Water Pipes.= By H. GRIMSHAW. 8vo, sewed. (_1887_) _net_ 1 0 =Cookery and Domestic Management=, including economic and middle class Practical Cookery. By K. MELLISH. 56 coloured plates and 441 illus. 987 pp. super-royal 8vo. (_1901_) _net_ 16 0 =Spons' Household Manual.= 250 illus. 1043 pp. demy 8vo. (_1902_) 7 6 Ditto ditto half-bound French morocco 9 0 DRAWING. =The Ornamental Penman's=, Engraver's and Sign Writer's Pocket Book of Alphabets. By B. ALEXANDER. Oblong 12mo, sewed 0 6 =Slide Valve Diagrams=: a French Method for their Construction. By L. BANKSON. 18mo, boards. (_New York, 1892_) _net_ 2 0 =A System of Easy Lettering.= By J. H. CROMWELL. With Supplement by G. MARTIN. Eleventh edition, 36 pp. oblong 8vo. (_New York, 1911_) _net_ 2 0 =Key to the Theory and Methods of Linear Perspective=, By C. W. DYMOND, F.S.A. 6 plates, 32 pp. cr. 8vo. (S. & C. SERIES, No. 20.) (_1910_) _net_ 1 6 =Plane Geometrical Drawing.= By R. C. FAWDRY. Illustrated, 185 pp. crown 8vo. (_1901_) _net_ 3 0 =Twelve Plates on Projection Drawing.= By O. GUETH. Oblong 4to. (_New York, 1903_) _net_ 3 0 =Hints on Architectural Draughtsmanship.= By G. W. T. HALLATT. Fourth edition, 80 pp. 18mo. (_1906_) _net_ 1 6 =A First Course of Mechanical Drawing= (Tracing). By G. HALLIDAY. Oblong 4to, sewed 2 0 =A Text-Book of Graphic Statics.= By C. W. MALCOLM. 155 illus. 316 pp. 8vo. (_New York, 1909_) _net_ 12 6 =Drawings for Medium-sized Repetition Work.= By R. D. SPINNEY. With 47 illus. 130 pp. 8vo. (_1909_). _net_ 3 6 =Mathematical Drawing Instruments.= By W. F. STANLEY. Seventh edition, 265 illus. 370 pp. crown 8vo. (_1900_) 5 0 =The Backbone of Perspective.= By T. U. TAYLOR. 40 illus. 56 pp. 18mo cloth. (_New York, 1911_) _net_ 4 6 EARTHWORK. =Tables for Computing the Contents of Earthwork= in the Cuttings and Embankments of Railways. By W. MACGREGOR. Royal 8vo 6 0 =Tables for facilitating the Calculation of Earthworks.= By D. CUNNINGHAM. 120 pp. royal 8vo 10 6 =Grace's Earthwork Tables.= 36 double-page tables, 4to. (_1907_) _net_ 12 6 =Earthwork Slips and Subsidences= on Public Works. By J. NEWMAN. 240 pp. cr. 8vo. (_1890_) 7 6 =Diagrams for the Graphic Calculation of Earthwork Quantities.= By A. H. Roberts. Ten cards, fcap. in cloth case _net_ 10 6 ELECTRICAL ENGINEERING. =Practical Electric Bell Fitting.= By F. C. ALLSOP. Tenth edition, 186 illus. including 8 folding plates, 185 pp. crown 8vo. (_1903_) 3 6 =Telephones=: their Construction and Fitting. By F. C. ALLSOP. Eighth edition, new impression, 184 illus. 222 pp. crown 8vo. (_1912_) _net_ 3 6 =Auto-Transformer Design.= By A. H. AVERY. 25 illus. 60 pp. 8vo. (_1909_) _net_ 3 6 =Principles of Electric Power= (Continuous Current) for Mechanical Engineers. By A. H. BATE. 63 illus. 204 pp. crown 8vo. (_1905_) (FINSBURY TECHNICAL MANUAL) _net_ 4 6 =Practical Construction of Electric Tramways.= By W. R. BOWKER. 93 illus. 119 pp. 8vo. (_1903_) _net_ 6 0 =The Electric Motor and its Practical Operation.= By E. E. BURNS. 78 illus. vi + 91 pp. crown 8vo. (_New York, 1912_) _net_ 7 0 =Electrical Ignition for Internal Combustion Engines.= By M. A. CODD. 109 illus. 163 pp. crown 8vo. (_1911_) _net_ 3 0 =Design and Construction of Induction Coils.= By A. F. COLLINS. 155 illus. 272 pp. demy 8vo. (_New York, 1909_) _net_ 12 6 =Plans and Specification for Wireless Telegraph Sets.= By A. F. COLLINS. Crown 8vo. (S. & C. SERIES, NOS. 41 AND 42). (_New York, 1912_) _each net_ 1 6 PART I. An Experimental Set and a One to Five Miles Set. 37 illus. viii + 45 pp. PART II. A Five to Ten Mile Set and a Ten to Twenty Mile Set. 63 illus. viii + 72 pp. =Switchboard Measuring Instruments= for Continuous and Polyphase Currents. By J. C. CONNAN. 117 illus. 150 pp. 8vo. (_1908_) _net_ 5 0 =Electric Cables, their Construction and Cost.= By D. COYLE and F. J. O. HOWE. With many diagrams and 216 tables, 466 pp. crown 8vo, leather. (_1909_) _net_ 15 0 =Management of Electrical Machinery.= By F. B. CROCKER and S. S. WHEELER. Eighth edition, 131 illus. 223 pp. crown 8vo. (_New York, 1909_) _net_ 4 6 =Electric Lighting=: A Practical Exposition of the Art. By F. B. CROCKER. Royal 8vo. (_New York._) Vol. I. =The Generating Plant.= Sixth edition, 213 illus. 470 pp. (_1904_) _net_ 12 6 Vol. II. =Distributing Systems and Lamps.= Second edition, 391 illus. 505 pp. (_1905_) _net_ 12 6 =The Care and Management of Ignition Accumulators.= By H. H. U. CROSS. 12 illus. 74 pp. crown 8vo. (S. & C. SERIES, No. 19.) (_1910_) _net_ 1 6 =Elements of Telephony.= By A. CROTCH. 51 illus. 90 pp. cr. 8vo. (S. & C. SERIES, No. 21.) (_1911_) _net_ 1 6 =Elementary Telegraphy and Telephony.= By ARTHUR CROTCH. New impression, 238 illus. viii + 223 pp. 8vo. (FINSBURY TECHNICAL MANUAL.) (_1912_) _net_ 4 6 =Electricity and Magnetism in Telephone Maintenance.= By G. W. CUMMINGS. 45 illus. 137 pp. 8vo. (_New York, 1908_) _net_ 6 6 =Grouping of Electric Cells.= By W. F. DUNTON. 4 illus. 50 pp. fcap. 8vo. (_1906_) _net_ 1 6 =Wireless Telegraphy for Intending Operators.= By C. K. P. EDEN. 20 illus. 80 pp. crown 8vo. (S. & C. SERIES, No. 24.) _In preparation._ =Magnets and Electric Currents.= By Prof. J. A. FLEMING. Second edition, 136 illus. 417 pp. crown 8vo. (_1902_) _net_ 5 0 =Notes on Design of Small Dynamo.= By GEORGE HALLIDAY. Second edition, 8 plates, 8vo. (_1895_) 2 6 =Practical Alternating Currents and Power Transmission.= By N. HARRISON. 172 illus. 375 pp. crown 8vo. (_New York, 1906_) _net_ 10 6 =Making Wireless Outfits.= By N. HARRISON. 27 illus. 61 pp. crown 8vo. (S. & C. SERIES, No. 11.) (_New York, 1909_) _net_ 1 6 =Wireless Telephone Construction.= By N. HARRISON. 43 illus. 73 pp. crown 8vo. (S. & C. SERIES, No. 12.) (_New York, 1909_) _net_ 1 6 =Testing Telegraph Cables.= By Colonel V. HOSKIOER. Third edition, 11 illus. viii + 75 pp. crown 8vo. (_1889_) 4 6 =Long Distance Electric Power Transmission.= By R. W. HUTCHINSON. 136 illus. 345 pp. crown 8vo. (_New York, 1907_) _net_ 12 6 =Theory and Practice of Electric Wiring.= By W. S. IBBETSON. 119 ill. 366 pp. cr. 8vo. (_1909_) _net_ 5 0 =Practical Electrical Engineering for Elementary Students.= By W. S. IBBETSON. 61 illus. 155 pp. crown 8vo. (_1910_) _net_ 3 6 =Form of Model General Conditions= recommended by THE INSTITUTION OF ELECTRICAL ENGINEERS for use in connection with Electrical Contracts. _New edition in preparation._ =Telegraphy for Beginners.= By W. H. JONES. 19 illus. 58 pp. crown 8vo. (_New York, 1910_) _net_ 2 0 =A Handbook of Electrical Testing.= By H. R. KEMPE. Seventh edition, 285 illus. 706 pp. demy 8vo. (_1908_) _net_ 18 0 =Electromagnets=, their design and construction. By A. N. MANSFIELD. 36 illus. 155 pp. 18mo, boards. (_New York, 1901_) _net_ 2 0 =Telephone Construction, Methods and Cost.= By C. MAYER. With Appendices on the cost of materials and labour by J. C. SLIPPY. 103 illus. 284 pp. crown 8vo. (_New York, 1908_) _net_ 12 6 =Storage Batteries, Stationary and Portable.= By J. P. NIBLETT. 22 illus. 80 pp. crown 8vo. (_New York, 1911_) _net_ 2 6 =House Wiring.= By T. W. POPPE. 73 illus. 103 pp. 12mo, limp. (_New York, 1912_) _net_ 3 0 =Practical Electrics=: a Universal Handybook on Every Day Electrical Matters. Seventh edition, 126 illus. 135 pp. 8vo. (S. & C. SERIES, No. 13.) (_New York, 1902_) _net_ 1 6 =Electroplating.= By H. C. REETZ. 62 illus. 99 pp. crown 8vo. (NEW YORK, 1911) _net_ 2 0 =Wiring Houses for the Electric Light.= By N. H. SCHNEIDER. 40 illus. 85 pp. crown 8vo. (S. & C. SERIES, No. 25.) (_New York, 1911_) _net_ 1 6 =Induction Coils.= By N. H. SCHNEIDER. Second edition, 79 illus. 285 pp. crown 8vo. (_New York, 1901_) _net_ 4 6 =Electric Gas Lighting.= By N. H. SCHNEIDER. 57 illus. 101 pp. cr. 8vo. (S. & C. SERIES, No. 8). (_New York, 1901_) _net_ 1 6 =How to Install Electric Bells, Annunciators and Alarms.= By N. H. SCHNEIDER. 59 illus. 63 pp. crown 8vo, limp. (S. & C. SERIES, No. 2.) (_New York, 1905_) _net_ 1 6 =Modern Primary Batteries=, their construction, use and maintenance. By N. H. SCHNEIDER. 54 illus. 94 pp. crown 8vo. (S. & C. SERIES, No. 1.) (_New York, 1905_) _net_ 1 6 =Practical Engineers' Handbook on the Care and Management of Electric Power Plants.= By N. H. SCHNEIDER. 203 illus. 274 pp. crown 8vo. (_New York, 1906_) _net_ 5 0 =Electrical Circuits and Diagrams=, illustrated and explained. By N. H. SCHNEIDER. 8vo. (S. & C. SERIES, NOS. 3 AND 4.) (_New York_) No. 3, Part 1. _New edition in preparation._ No. 4, Part 2. 73 pp. (_1909_) _net_ 1 6 =Electrical Instruments and Testing.= By N. H. SCHNEIDER. Third edition. 133 illus. 239 pp. crown 8vo. (_New York, 1907_) _net_ 4 6 =Experimenting with Induction Coils.= By N. H. SCHNEIDER. 26 illus. 73 pp. crown 8vo. (S. & C. SERIES, No. 5.) (_New York, 1906_) _net_ 1 6 =Study of Electricity for Beginners.= By N. H. SCHNEIDER. 54 illus. 88 pp. crown 8vo. (S. & C. SERIES, No. 6.) (_New York, 1905_) _net_ 1 6 =Wiring Houses for the Electric Light=: Low Voltage Battery Systems. 44 illus. 86 pp. crown 8vo. (S. & C. SERIES, No. 25.) (_New York, 1911_) _net_ 1 6 =Low Voltage Electric Lighting with the Storage Battery.= By N. H. SCHNEIDER. 23 illus. 85 pp. crown 8vo. (S. & C. SERIES, No. 26.) (_New York, 1911_) _net_ 1 6 =Dry Batteries=: how to Make and Use them. By a DRY BATTERY EXPERT. With additional notes by N. H. SCHNEIDER. 30 illus. 59 pp. crown 8vo. (S. & C. SERIES, No. 7.) (_New York, 1905_) _net_ 1 6 =The Diseases of Electrical Machinery.= By E. SCHULZ. Edited, with a Preface, by Prof. S. P. THOMPSON. 42 illus. 84 pp. crown 8vo _net_ 2 0 =Electricity Simplified.= By T. O. SLOANE. Tenth edition, 29 illus. 158 pp. crown 8vo. (_New York, 1901_) _net_ 4 6 =How to become a Successful Electrician.= By T. O. SLOANE. Third edition, 4 illus. 202 pp. crown 8vo. (_New York, 1899_) _net_ 4 6 =Electricity=: its Theory, Sources and Applications. By J. T. SPRAGUE. Third edition, 109 illus. 658 pp. crown 8vo (_1892_) _net_ 7 6 =Telegraphic Connections.= By C. THOM and W. H. JONES. 20 plates, 59 pp. oblong 8vo. (_New York, 1892_) _net_ 3 6 =Dynamo Electric Machinery.= By Prof. S. P. THOMPSON. Seventh edition, demy 8vo. (FINSBURY TECHNICAL MANUAL.) Vol. I. =Continuous-Current Machinery.= With 4 coloured and 30 folding plates, 573 illus. 984 pp. (_1904_) _net_ 1 10 0 Vol. II. =Alternating Current Machinery.= 15 coloured and 24 folding plates, 546 illus. 900 pp. (_1905_) _net_ 1 10 0 =Design of Dynamos= (Continuous Currents). By Prof. S. P. THOMPSON. 4 coloured and 8 folding plates, 243 pp. demy 8vo. (_1903_) _net_ 12 0 =Schedule for Dynamo Design=, issued with the above. 6_d._ each, 4_s._ per doz., or 18_s._ per 100 _net_ =Curves of Magnetic Data for Various Materials.= A reprint on transparent paper for office use of Plate I from Dynamo Electric Machinery, and measuring 25 in. by 16 in. _net_ 0 7 =The Electromagnet.= By C. R. UNDERHILL. 67 illus. 159 pp. crown 8vo. (_New York, 1903_) _net_ 6 6 =Practical Guide to the Testing of Insulated Wires and Cables.= By H. L. WEBB. Fifth edition, 38 illus. 118 pp. crown 8vo. (_New York, 1902_) _net_ 4 6 =Wiring Rules.= With Extracts from the Board of Trade Regulations and the Home Office Regulations for Factories and Workshops. Issued by =The Institution of Electrical Engineers.= Sixth edition, 42 pp. 8vo, sewed. (_1911_) _net_ 0 6 FOREIGN EXCHANGE. =English Prices with Russian Equivalents= (at Fourteen Rates of Exchange). English prices per lb., with equivalents in roubles and kopecks per pood. By A. ADIASSEWICH. 182 pp. fcap. 32mo, roan. (_1908_) _net_ 1 0 =English Prices with German Equivalents= (at Seven Rates of Exchange). English prices per lb., with equivalents in marks per kilogramme. By ST. KOCZOROWSKI. 95 pp. fcap. 32mo, roan. (_1909_) _net_ 1 0 =English Prices with Spanish Equivalents.= At Seven Rates of Exchange. English prices per lb., with equivalents in pesetas per kilogramme. By S. LAMBERT. 95 pp. 32mo, roan. (_1910_) _net_ 1 0 =English Prices with French Equivalents= (at Seven Rates of Exchange). English prices per lb. to francs per kilogramme. By H. P. MCCARTNEY. 97 pp. 32mo, roan. (_1907_) _net_ 1 0 =Principles of Foreign Exchange.= By E. MATHESON. Fourth edition, 54 pp. 8vo, sewed. (_1905_) _net_ 0 3 GAS AND OIL ENGINES. =The Theory of the Gas Engine.= By D. CLERK. Edited by F. E. IDELL. Third edition, 19 illus. 180 pp. 18mo, boards. (_New York, 1903_) _net_ 2 0 =Electrical Ignition for Internal Combustion Engines.= By M. A. CODD. 109 illus. 163 pp. crown 8vo. (_1911_) _net_ 3 0 =The Design and Construction of Oil Engines.= By A. H. GOLDINGHAM. Third edition, 112 illus. 260 pp. crown 8vo. (_New York, 1910_) _net_ 10 6 =Gas Engine in Principle and Practice.= By A. H. GOLDINGHAM. New Impression. 107 illus. 195 pp. 8vo. (_New York, 1912_) _net_ 6 6 =Practical Hand-Book on the Care and Management of Gas Engines.= By G. LIECKFELD. Third edition, square 16mo. (_New York, 1896_) 3 6 =Elements of Gas Engine Design.= By S. A. MOSS. 197 pp. 18mo, boards. (_New York, 1907_) _net_ 2 0 =Gas and Petroleum Engines.= A Manual for Students and Engineers. By Prof. W. ROBINSON. (FINSBURY TECHNICAL MANUAL.) _Third edition in preparation_ GAS LIGHTING. =Gas Analyst's Manual= (incorporating Hartley's "Gas Analyst's Manual" and "Gas Measurement"). By J. ABADY. 102 illus. 576 pp. demy 8vo. (_1902_) _net_ 18 0 =Gas Works=: their Arrangement, Construction, Plant and Machinery. By F. COLYER. 31 folding plates, 134 pp. 8vo. (_1884_) _net_ 8 6 =Transactions of the Institution of Gas Engineers.= Edited by WALTER T. DUNN, _Secretary_. Published annually. 8vo _net_ 10 6 =Lighting by Acetylene.= By F. DYE. 75 illus. 200 pp. crown 8vo. (_1902_) _net_ 6 0 =A Comparison of the English and French Methods of Ascertaining the Illuminating Power of Coal Gas.= By A. J. VAN EIJNDHOVEN. Illustrated, crown 8vo. (_1897_) 4 0 =Gas Lighting and Gas Fitting.= By W. P. GERHARD. Second edition, 190 pp. 18mo, boards. (_New York, 1894_) _net_ 2 0 =A Treatise on the Comparative Commercial Values of Gas Coals and Cannels.= By D. A. GRAHAM. 3 plates, 100 pp. 8vo. (_1882_) 4 6 =The Gas Engineers Laboratory Handbook.= By J. HORNBY. Third edition, revised, 70 illus. 330 pp. crown 8vo. (_1911_) _net_ 6 0 HISTORICAL AND BIOGRAPHICAL. =Extracts from the Private Letters of the late Sir William Fothergill Cooke=, 1836-9, relating to the Invention and Development of the Electric Telegraph; also a Memoir by LATIMER CLARK. Edited by F. H. WEBB, Sec. Inst. E.E. 8vo. (_1895_) 3 0 =A Chronology of Inland Navigation= in Great Britain. By H. R. DE SALIS. Crown 8vo. (_1897_) 4 6 =A History of Electric Telegraphy= to the year 1837. By J. J. FAHIE. 35 illus. 542 pp. crown 8vo. (_1889_) 2 0 =History and Development of Steam Locomotion on Common Roads.= By W. FLETCHER. 109 illus. 288 pp. 8vo. 5 0 =Life as an Engineer=: its Lights, Shades, and Prospects. By J. W. C. HALDANE. New edition, 23 plates, 390 pp. crown 8vo. (_1910_) _net_ 5 0 =Philipp Reis=, Inventor of the Telephone: a Biographical Sketch. By Prof. S. P. THOMPSON. 8vo, cloth. (_1883_) 7 6 =The Development of the Mercurial Air Pump.= By Prof. S. P. THOMPSON. Illustrated, royal 8vo, sewed. (_1888_) 1 6 HOROLOGY. =Watch and Clock Maker's Handbook=, Dictionary and Guide. By F. J. BRITTEN. Tenth edition, 450 illus. 492 pp. crown 8vo. (_1902_) _net_ 5 0 =The Springing and Adjusting of Watches.= By F. J. BRITTEN. 75 illus. 152 pp. crown 8vo. (_1898_) _net_ 3 0 =Prize Essay on the Balance Spring= and its Isochronal Adjustments. By M. IMMISCH. 7 illus. 50 pp. crown 8vo. (_1872_) 2 6 HYDRAULICS AND HYDRAULIC MACHINERY. (_See also_ IRRIGATION _and_ WATER SUPPLY.) =The Suction Caused by Ships= explained in popular language. By E. S. BELLASIS. 2 plates, 26 pp. 8vo, sewed. (_1912_) _net_ 1 0 =Hydraulics with Working Tables.= By E. S. BELLASIS. Second edition, 160 illus. xii + 311 pp. 8vo. (_1911_) _net_ 12 0 =Pumps=: Historically, Theoretically and Practically Considered. By P. R. BJÖRLING. Second edition, 156 illus. 234 pp. crown 8vo. (_1895_) 7 6 =Pump Details.= By P. R. BJÖRLING. 278 illus. 211 pp. crown 8vo. (_1892_) 7 6 =Pumps and Pump Motors=: A Manual for the use of Hydraulic Engineers. By P. R. BJÖRLING. Two vols. 261 plates, 369 pp. royal 4to. (_1895_) _net_ 1 10 0 =Practical Handbook on Pump Construction.= By P. R. BJÖRLING. Second edition, 9 plates, 90 pp. crown 8vo. (_1904_) 5 0 =Water or Hydraulic Motors.= By P. R. BJÖRLING. 206 illus. 287 pp. crown 8vo. (_1903_) 9 0 =Hydraulic Machinery=, with an Introduction to Hydraulics. By R. G. BLAINE. Second edition, with 307 illus. 468 pp. 8vo. (FINSBURY TECHNICAL MANUAL.) (_1905_) _net_ 14 0 =Practical Hydraulics.= By T. BOX. Fifteenth edition, 8 plates, 88 pp. crown 8vo. (_1909_) _net_ 5 0 =Pumping and Water Power.= By F. A. BRADLEY. 51 illus., vii + 118 pp. demy 8vo. (_1912_) _net_ 4 6 =Hydraulic, Steam, and Hand Power Lifting and Pressing Machinery.= By F. COLYER. Second edition, 88 plates, 211 pp. imperial 8vo. (_1892_) _net_ 10 6 =Pumps and Pumping Machinery.= By F. COLYER. Vol. I. Second edition, 53 plates, 212 pp. 8vo (_1892_) _net_ 10 6 Vol. II. Second edition, 48 plates, 169 pp. 8vo. (_1900_) _net_ 10 6 =Construction of Horizontal and Vertical Waterwheels.= By W. CULLEN. Second edition, small 4to. (_1871_) 5 0 =Donaldson's Poncelet Turbine= and Water Pressure Engine and Pump. By W. DONALDSON. 2 plates, viii + 32 pp. demy 4to. (_1883_) 5 0 =Principles of Construction and Efficiency of Waterwheels.= By W. DONALDSON. 13 illus. 94 pp. 8vo. (_1876_) 5 0 =Practical Hydrostatics and Hydrostatic Formulæ.= By E. S. GOULD. 27 illus. 114 pp. 18mo, boards. (_New York, 1903_) _net_ 2 0 =Hydraulic and other Tables= for purposes of Sewerage and Water Supply. By T. HENNELL. Third edition, 70 pp. crown 8vo. (_1908_) _net_ 4 6 =Tables for Calculating the Discharge of Water= in Pipes for Water and Power Supplies. Indexed at side for ready reference. By A. E. SILK. 63 pp. crown 8vo. (_1899_) 5 0 =Simple Hydraulic Formulæ.= By T. W. STONE. 9 plates, 98 pp. crown 8vo. (_1881_) 4 0 =A B C of Hydrodynamics.= By LT.-COL. R. DE VILLAMIL, R.E. (retd.). 48 illus. xi + 135 pp. demy 8vo. (_1912_) _net_ 6 0 INDUSTRIAL CHEMISTRY AND MANUFACTURES. =Perfumes and their Preparation.= By G. W. ASKINSON. Translated from the Third German Edition by I. FUEST. Third edition, 32 illus. 312 pp. 8vo. (_New York, 1907_) _net_ 12 6 =Brewing Calculations=, Gauging and Tabulation. By C. H. BATER. 340 pp. 64mo, roan, gilt edges. (_1897_) _net_ 1 6 =A Pocket Book for Chemists=, Chemical Manufacturers, Metallurgists, Dyers, Distillers, etc. By T. BAYLEY. Seventh edition, new impression, 550 pp. royal 32mo, roan, gilt edges. (_1912_) _net_ 5 0 =Practical Receipts= for the Manufacturer, the Mechanic, and for Home use. By Dr. H. R. BERKELEY and W. M. WALKER. New impression, 250 pp. demy 8vo. (_1912_) _net_ 5 0 =A Treatise on the Manufacture of Soap and Candles=, Lubricants and Glycerine. By W. L. CARPENTER and H. LEASK. Second edition, 104 illus. 456 pp. crown 8vo. (_1895_) 12 6 =A Text Book of Paper Making.= By C. F. CROSS and E. J. BEVAN. Third edition, 97 illus. 411 pp. crown 8vo. (_1907_) _net_ 12 6 =C.B.S. Standard Units and Standard Paper Tests.= By C. F. CROSS, E. J. BEVAN, C. BEADLE and R. W. SINDALL. 25 pp. crown 4to. (_1903_) _net_ 2 6 =Pyrometry.= By C. R. DARLING. 60 illus. 200 pp. crown 8vo. (_1911_) _net_ 5 0 =Soda Fountain Requisites.= A Practical Receipt Book for Druggists, Chemists, etc. By G. H. DUBELLE. Third edition, 157 pp. crown 8vo. (_New York, 1905_) _net_ 4 6 =Spices and How to Know Them.= By W. M. GIBBS. 47 plates, including 14 in colours, 176 pp. 8vo. (_New York, 1909_) _net_ 15 0 =The Chemistry of Fire= and Fire Prevention. By H. and H. INGLE. 45 illus. 290 pp. crown 8vo. (_1900_) 9 0 =Ice-Making Machines.= By M. LEDOUX and others. Sixth edition, 190 pp. 18mo, boards. (_New York, 1906_) _net_ 2 0 =Brewing with Raw Grain.= By T. W. LOVIBOND. 75 pp. crown 8vo. (_1883_) 5 0 =The Chemistry, Properties, and Tests of Precious Stones.= By J. Mastin. 114 pp. fcap. 16mo, limp leather, gilt top. (_1911_) _net_ 2 6 =Sugar, a Handbook for Planters and Refiners.= By the late J. A. R. NEWLANDS and B. E. R. NEWLANDS. 236 illus. 876 pp. 8vo. (_1909_) _net_ 1 5 0 =Principles of Leather Manufacture.= By Prof. H. R. PROCTER. 101 illus. 520 pp. medium 8vo. (_1908_) _net_ 18 0 =Leather Industries Laboratory Handbook= of Analytical and Experimental methods. By H. R. PROCTER. Second edition, 4 plates, 46 illus. 450 pp. demy 8vo. (_1908_) _net_ 18 0 =Leather Chemists' Pocket Book.= A short compendium of Analytical Methods. By Prof. H. R. PROCTER. Assisted by Dr. E. STIASNY and H. BRUMWELL. (_In the Press_.) =Theoretical and Practical Ammonia Refrigeration.= By I. I. REDWOOD. Sixth thousand, 15 illus. 146 pp. square 16mo. (_New York, 1909_) _net_ 4 6 =Breweries and Maltings.= By G. SCAMMELL and F. COLYER. Second edition, 20 plates, 178 pp. 8vo. (_1880_) _net_ 6 0 =Factory Glazes for Ceramic Engineers.= By H. RUM-BELLOW. Folio. Series A, Leadless Sanitary Glazes. (_1908_) _net_ 2 2 0 =Spons' Encyclopædia of the Industrial Arts=, Manufactures and Commercial Products. 1500 illus. 2100 pp. super-royal 8vo. (_1882_) In 2 Vols, cloth _net_ 2 2 0 =The Absorption Refrigerating Machine.= By G. T. VOORHEES. 42 illus. 144 pp. narrow crown 8vo. (_New York, 1911_) _net_ 8 6 =Tables for the Quantitative Estimation of the Sugars.= By E. WEIN and W. FREW. Crown 8vo. (_1896_) 6 0 =The Puering, Bating and Drenching of Skins.= By J. T. WOOD. 33 illus. xv + 300 pp. demy 8vo. (_1912_) _net_ 12 6 =Workshop Receipts.= For the use of Manufacturers, Mechanics and Scientific Amateurs. NEW AND THOROUGHLY REVISED EDITION, crown 8vo. (_1909_) _each net_ 3 0 Vol. I. ACETYLENE LIGHTING _to_ DRYING. 223 illus. 532 pp. Vol. II. DYEING _to_ JAPANNING. 259 illus. 540 pp. Vol. III. JOINTING PIPES _to_ PUMPS. 256 illus. 528 pp. Vol. IV. RAINWATER SEPARATORS _to_ WIRE ROPE, SPLICING. 321 illus. 540 pp. =Practical Handbook on the Distillation of Alcohol from Farm Products.= By F. B. WRIGHT. Second edition, 60 illus. 271 pp. crown 8vo. (_New York, 1907_) _net_ 4 6 =The Manufacture of Chocolate= and other Cacao Preparations. By P. ZIPPERER. Second edition, 87 illus. 280 pp. royal 8vo. (_1902_) _net_ 16 0 INTEREST TABLES. =The Wide Range Dividend and Interest Calculator=, showing at a glance the Percentage on any sum from One Pound to Ten Thousand Pounds, at any Interest, from 1% to 12-1/2%, proceeding by 1/4%. By A. STEVENS. 100 pp. super royal 8vo, cloth _net_ 6 0 Quarter morocco, cloth sides _net_ 7 6 =The Wide Range Income Tax Calculator=, showing at a glance the Tax on any sum from One Shilling to Thousand Pounds, at the Rate of 9_d._, 1/- and 1/2 in the Pound. By A. STEVENS. On folding card, imperial 8vo _net_ 1 0 IRRIGATION. =Punjab Rivers and Works.= By E. S. BELLASIS. 47 illus. 65 pp. folio, cloth. (_1911_) _net_ 8 0 =Irrigation Pocket Book.= By R. B. BUCKLEY. 419 pp. crown 8vo, leather cloth with rounded corners. (_1911_) _net_ 12 6 =The Design of Channels for Irrigation and Drainage.= By R. B. BUCKLEY. 22 diagrams, 56 pp. crown 8vo. (_1911_) _net_ 2 0 =The Irrigation Works of India.= By R. B. BUCKLEY. Second edition, with coloured maps and plans. 336 pp. 4to, cloth. (_1905_) _net_ 2 2 0 =Irrigated India.= By Hon. ALFRED DEAKIN. With Map, 322 pp. 8vo. (_1893_) 8 6 =Indian Storage Reservoirs=, with Earthen Dams. By W. L. STRANGE. _Second edition in preparation_ =The Irrigation of Mesopotamia.= By Sir W. WILLCOCKS. 2 vols. 46 plates, 136 pp. (Text super-royal 8vo, plates folio). (_1911_) _net_ 1 0 0 =Egyptian Irrigation.= By Sir W. WILLCOCKS. _Third edition in preparation._ _A few copies of the First Edition (1889) are still to be had. Price_ 15_s. net._ =The Nile Reservoir Dam at Assuan=, and After. By Sir W. WILLCOCKS. Second edition, 13 plates, super-royal 8vo. (_1903_) _net_ 6 0 =The Assuân Reservoir and Lake Moeris.= By Sir W. WILLCOCKS. With text in English, French and Arabic. 5 plates, 116 pp. super-royal 8vo. (_1904_) _net_ 5 0 =The Nile in 1904.= By Sir W. WILLCOCKS. 30 plates, 200 pp. super-royal 8vo. (_1904_) _net_ 9 0 LOGARITHM TABLES. =Aldum's Pocket Folding Mathematical Tables.= Four-figure logarithms, and Anti-logarithms, Natural Sines, Tangents, Cotangents, Cosines, Chords and Radians for all angles from 1 to 90 degrees. And Decimaliser Table for Weights and Money. On folding card. _Net_ 4_d._ 20 copies, _net_ 6_s._ =Tables of Seven-figure Logarithms= of the Natural Numbers from 1 to 108,000. By C. BABBAGE. Stereotype edition, 8vo _net_ 5 0 =Four-Place Tables of Logarithms and Trigonometric Functions.= By E. V. HUNTINGTON. Ninth thousand, 34 pp. square 8vo, limp buckram, with cut lateral index. (_New York, 1911_) _net_ 3 0 =Short Logarithmic= and other Tables. By W. C. UNWIN. Fourth edition, small 4to 3 0 =Logarithmic Land Measurement.= By J. WALLACE. 32 pp. royal 8vo. (_1910_) _net_ 5 0 =A B C Five-figure Logarithms with Tables, for Chemists.= By C. J. WOODWARD. Crown 8vo _net_ 2 6 =A B C Five-figure Logarithms= for general use, with lateral index for ready reference. By C. J. WOODWARD. Second edition, with cut lateral Index, 116 pp. 12mo, limp leather _net_ 3 0 MARINE ENGINEERING AND NAVAL ARCHITECTURE. =Marine Propellers.= By S. W. BARNABY. Fifth edition, 5 plates, 56 illus. 185 pp. demy 8vo. (_1908_) _net_ 10 6 =Marine Engineer's Record Book=: Engines. By B. C. BARTLEY. 8vo, roan _net_ 5 0 =The Suction Caused by Ships and the Olympic-Hawke Collision.= By E. S. BELLASIS. 1 chart and 5 illus. in text, 26 pp. 8vo, sewed. (_1912_) _net_ 1 0 =Yachting Hints=, Tables and Memoranda. By A. C. FRANKLIN. Waistcoat pocket size, 103 pp. 64mo, roan, gilt edges _net_ 1 0 =Steamship Coefficients, Speeds and Powers.= By C. F. A. FYFE. 31 plates, 280 pp. fcap. 8vo, leather. (_1907_) _net_ 10 6 =Steamships and Their Machinery=, from first to last. By J. W. C. HALDANE. 120 illus. 532 pp. 8vo. (_1893_) 15 0 =Tables for Constructing Ships' Lines.= By A. HOGG. Third edition, 3 plates, 20 pp. 8vo, sewed (_1911_) _net_ 3 0 =Submarine Boats.= By G. W. HOVGAARD. 2 plates, 98 pp. crown 8vo. (_1887_) 5 0 =Tabulated Weights= of Angle, Tee, Bulb, Round, Square, and Flat Iron and Steel for the use of Naval Architects, Ship-builders, etc. By C. H. JORDAN. Sixth edition, 640 pp. royal 32mo, French morocco, gilt edges. (_1909_) _net_ 7 6 =Particulars of Dry Docks=, Wet Docks, Wharves, etc. on the River Thames. Compiled by C. H. JORDAN. Second edition, 7 coloured charts, 103 pp. oblong 8vo. (_1904_) _net_ 2 6 =Marine Transport of Petroleum.= By H. LITTLE. 66 illus. 263 pp. crown 8vo. (_1890_) 10 6 =Questions and Answers for Marine Engineers=, with a Practical Treatise on Breakdowns at Sea. By T. LUCAS. 12 folding plates, 515 pp. gilt edges, crown 8vo. (_New York, 1902_) _net_ 8 0 =Reed's Engineers' Handbook to the Board of Trade Examinations= for certificates of Competency as First and Second Class Engineers. Nineteenth edition, 37 plates, 358 illus. 696 pp. 8vo _net_ 14 0 =Key to Reed's Handbook= _net_ 7 6 =Reed's Marine Boilers.= Second edition, crown 8vo _net_ 4 6 =Reed's Useful Hints to Sea-going Engineers.= Fourth edition, 8 plates, 50 illus. 312 pp. crown 8vo. (_1903_) _net_ 3 6 MATERIALS. =Practical Treatise on the Strength of Materials.= By T. BOX. Fourth edition, 27 plates, 536 pp. 8vo. (_1902_) _net_ 12 6 =Treatise on the Origin, Progress, Prevention and Cure of Dry Rot in Timber.= By T. A. BRITTON. 10 plates, 519 pp. crown 8vo. (_1875_) 7 6 =Solid Bitumens.= By S. F. PECKHAM. 23 illus. 324 pp. 8vo. (_New York, 1909_) _net_ 1 1 0 =Lubricants, Oils and Greases.= By I. I. REDWOOD. 3 plates, ix + 54 pp. 8vo. (_1898_) _net_ 6 6 =Practical Treatise on Mineral Oils= and their By-Products. By I. I. REDWOOD. 67 illus. 336 pp. demy 8vo. (_1897_) 15 0 =Silico-Calcareous Sandstones=, or Building Stones from Quartz, Sand and Lime. By E. STOFFLER. 5 plates, 8vo, sewed. (_1901_) _net_ 4 0 =Proceedings of the Fifth Congress, International Association for Testing Materials.= English edition. 189 illus. 549 pp. demy 8vo. (_1910_). Paper _net_ 15 0 Cloth _net_ 18 0 MATHEMATICS. =Imaginary Quantities.= By M. ARGAND. Translated by PROF. HARDY. 18mo, boards. (_New York_) _net_ 2 0 =Text Book of Practical Solid Geometry.= By E. H. DE V. ATKINSON. Revised by MAJOR B. R. WARD, R.E. Second edition, 17 plates, 8vo. (_1901_) 7 6 =Quick and Easy Methods of Calculating=, and the Theory and Use of the Slide Rule. By R. G. BLAINE. Fourth edition, 6 illus. xii + 152 pp. 16mo, leather cloth. (_1912_) _net_ 2 6 =Symbolic Algebra=, or the Algebra of Algebraic Numbers. By W. CAIN. 18mo, boards. (_New York_) _net_ 2 0 =Nautical Astronomy.= By J. H. COLVIN. 127 pp. crown 8vo. (_1901_) _net_ 2 6 =Chemical Problems.= By J. C. FOYE. Fourth edition, 141 pp. 18mo, boards. (_New York, 1898_) _net_ 2 0 =Primer of the Calculus.= By E. S. GOULD. Second edition, 24 illus. 122 pp. 18mo, boards. (_New York, 1899_) _net_ 2 0 =Elementary Treatise on the Calculus= for Engineering Students. By J. GRAHAM. Third edition, 276 pp. crown 8vo. (FINSBURY TECHNICAL MANUAL.) (_1905_) 7 6 =Manual of the Slide Rule.= By F. A. HALSEY. Second edition, 31 illus. 84 pp. 18mo, boards. (_New York, 1901_) _net_ 2 0 =Reform in Chemical and Physical Calculations.= By C. J. T. HANSSEN. 4to. (_1897_) _net_ 6 6 =Algebra Self-Taught.= By P. HIGGS. Third edition, 104 pp. crown 8vo. (_1903_) 2 6 =A Text-book on Graphic Statics.= By C. W. MALCOLM. 155 illus. 316 pp. 8vo. (_New York, 1909_) _net_ 12 6 =Galvanic Circuit investigated Mathematically.= By G. S. OHM. Translated by WILLIAM FRANCIS. 269 pp. 18mo, boards. (_New York, 1891_) _net_ 2 0 =Elementary Practical Mathematics.= By M. T. ORMSBY. Second edition, 128 illus. xii + 410 pp. medium 8vo. (_1911_) _net_ 5 0 =Elements of Graphic Statics.= By K. VON OTT. Translated by G. S. CLARKE. 93 illus. 128 pp. crown 8vo. (_1901_) 5 0 =Figure of the Earth.= By F. C. ROBERTS. 18mo, boards. (_New York_) _net_ 2 0 =Arithmetic of Electricity.= By T. O'C. SLOANE. Thirteenth edition, 5 illus. 162 pp. crown 8vo. (_New York, 1901_) _net_ 4 6 =Graphic Method for Solving certain Questions in Arithmetic or Algebra.= By G. L. VOSE. Second edition with 28 illus. 62 pp. 18mo, boards. (_New York, 1902_) _net_ 2 0 =Problems in Electricity.= A Graduated Collection comprising all branches of Electrical Science. By R. WEBER. Translated from the French by E. A. O'KEEFE. 34 illus. 366 pp. crown 8vo. (_1902_) _net_ 7 6 MECHANICAL ENGINEERING. STEAM ENGINES AND BOILERS, ETC. =Engineers' Sketch Book of Mechanical Movements.= By T. W. BARBER. Fifth edition, 3000 illus. 355 pp. 8vo. (_1906_) _net_ 10 6 =The Repair and Maintenance of Machinery.= By T. W. BARBER. 417 illus. 476 pp. 8vo. (_1895_) 10 6 =Practical Treatise on Mill Gearing.= By T. BOX. Fifth edition, 11 plates, 128 pp. crown 8vo. (_1892_) 7 6 =The Mechanical Engineers' Price Book, 1912.= Edited by G. BROOKS. 176 pp. pocket size (6-1/2 in. by 3-3/4 in. by 1/2 in. thick), leather cloth, with rounded corners. (_1912_) _net_ 4 0 =Safety Valves.= By R. H. BUELL. Third edition, 20 illus. 100 pp. 18mo, boards. (_New York, 1898_) _net_ 2 0 =Machine Design.= By Prof. W. L. CATHCART. Part I. FASTENINGS. 123 illus. 291 pp. demy 8vo. (_New York, 1903_) _net_ 12 6 =Chimney Design and Theory.= By W. W. CHRISTIE. Second edition, 54 illus. 192 pp. crown 8vo. (_New York, 1902_) _net_ 12 6 =Furnace Draft=: its Production by Mechanical Methods. By W. W. CHRISTIE. 5 illus. 80 pp. 18mo, boards. (_New York, 1906_) _net_ 2 0 =The Stokers' Catechism.= By W. J. CONNOR. 63 pp. limp cloth. (_1906_) _net_ 1 0 =Treatise on the use of Belting= for the Transmission of Power. By J. H. COOPER. Fifth edition, 94 illus. 399 pp. demy 8vo. (_New York, 1901_) _net_ 12 6 =The Steam Engine considered as a Thermodynamic Machine.= By J. H. COTTERILL. Third edition, 39 diagrams, 444 pp. 8vo. (_1896_) 15 0 =Fireman's Guide=, a Handbook on the Care of Boilers. By K. P. DAHLSTROM. Eleventh edition, fcap. 8vo, limp. (S. & C. SERIES, No. 16.) (_New York, 1906_) _net_ 1 6 =Heat for Engineers.= By C. R. DARLING. Second edition, 110 illus. 430 pp. 8vo. (FINSBURY TECHNICAL MANUAL.) (_1912_) _net_ 12 6 =Diseases of a Gasolene Automobile=, and How to Cure Them. By A. L. DYKE. 127 illus. 201 pp. crown 8vo. (_New York, 1903_) _net_ 6 6 =Belt Driving.= By G. HALLIDAY. 3 folding plates, 100 pp. 8vo. (_1894_) 3 6 =Worm and Spiral Gearing.= By F. A. HALSEY. 13 plates, 85 pp. 18mo, boards. (_New York, 1903_) _net_ 2 0 =Commercial Efficiency of Steam Boilers.= By A. HANSSEN. Large 8vo, sewed. (_1898_) 0 6 =Corliss Engine.= By J. T. HENTHORN. Third edition, 23 illus. 95 pp. square 16mo. (S. & C. SERIES, No. 23.) (_New York, 1910_) _net_ 1 6 =Liquid Fuel= for Mechanical and Industrial Purposes. By E. A. BRAYLEY HODGETTS. 106 illus. 129 pp. 8vo. (_1890_) 5 0 =Elementary Text-Book on Steam Engines and Boilers.= By J. H. KINEALY. Fourth edition, 106 illus. 259 pp. 8vo. (_New York, 1903_) _net_ 8 6 =Centrifugal Fans.= By J. H. KINEALY. 33 illus. 206 pp. fcap. 8vo, leather. (_New York, 1905_) _net_ 12 6 =Mechanical Draft.= By J. H. KINEALY. 27 original tables and 13 plates, 142 pp. crown 8vo. (_New York, 1906_) _net_ 8 6 =The A B C of the Steam Engine=, with a description of the Automatic Governor. By J. P. LISK. 6 plates, crown 8vo. (S. & C. SERIES, No. 17.) (_New York, 1910_) _net_ 1 6 =Valve Setting Record Book.= By P. A. LOW. 8vo, boards 1 6 =The Lay-out of Corliss Valve Gears.= By S. A. MOSS. Second edition, 3 plates, 108 pp. 18mo, boards. (_New York, 1906_) _net_ 2 0 =Steam Boilers=, their Management and Working. By J. PEATTIE. Fifth edition, 35 illus. 230 pp. crown 8vo. (_1906_) _net_ 4 6 =Treatise on the Richards Steam Engine Indicator.= By C. T. PORTER. Sixth edition, 3 plates and 73 diagrams, 285 pp. 8vo. (_1902_) 9 0 =Practical Treatise on the Steam Engine.= By A. RIGG. Second edition, 103 plates, 378 pp. demy 4to. (_1894_) 15 0 =Power and its Transmission.= A Practical Handbook for the Factory and Works Manager. By T. A. SMITH. 76 pp. fcap. 8vo. (_1910_) _net_ 2 0 =Drawings for Medium Sized Repetition Work.= By R. D. SPINNEY. With 47 illus. 130 pp. 8vo. (_1909_) _net_ 3 6 =Slide Valve Simply Explained.= By W. J. TENNANT. Revised by J. H. KINEALY. 41 illus. 83 pp. crown 8vo. (_New York, 1899_) _net_ 4 6 =Shaft Governors.= By W. TRINKS and C. HOOSUM. 27 illus. 97 pp. 18mo, boards. (_New York, 1905_) _net_ 2 0 =Treatise on the Design and Construction of Mill Buildings.= By H. G. TYRRELL. 652 illus. 490 pp. 8vo. (_New York, 1911_) _net_ 17 0 =Slide and Piston Valve Geared Steam Engines.= By W. H. UHLAND. 47 plates and 314 illus. 155 pp. Two vols. folio, half morocco. (_1882_) 1 16 0 =How to run Engines and Boilers.= By E. P. WATSON. Fifth edition, 31 illus. 160 pp. crown 8vo. (_New York, 1904_) 3 6 =Position Diagram of Cylinder with Meyer Cut-off.= By W. H. WEIGHTMAN. On card. (_New York_) _net_ 1 0 =Practical Method of Designing Slide Valve Gearing.= By E. J. WELCH. 69 diagrams, 283 pp. crown 8vo. (_1890_) 6 0 =Elements of Mechanics.= By T. W. WRIGHT. Eighth edition, illustrated, 382 pp. 8vo. (_New York, 1909_) _net_ 10 6 METALLURGY. IRON AND STEEL MANUFACTURE. =Life of Railway Axles.= By T. ANDREWS. 8vo, sewed. (_1895_) 1 0 =Microscopic Internal Flaws in Steel Rails and Propeller Shafts.= By T. ANDREWS. 8vo, sewed. (_1896_) 1 0 =Microscopic Internal Flaws, Inducing Fracture in Steel.= By T. ANDREWS. 8vo, sewed. (_1896_) 2 0 =Practical Alloying.= A compendium of Alloys and Processes for Brassfounders, Metal Workers, and Engineers. By JOHN F. BUCHANAN. With 41 illus. 205 pp. 8vo, cloth. (_New York, 1911_) _net_ 10 6 =Brassfounders' Alloys.= By J. F. BUCHANAN. Illustrated, 129 pp. crown 8vo. (_1905_) _net_ 4 6 =The Moulder's Dictionary= (Foundry Nomenclature). A concise guide to Foundry Practice. By JOHN F. BUCHANAN. New impression, 26 illus. viii + 225 pp. crown 8vo. (_1912_) _net_ 3 0 =American Standard Specifications for Steel.= By A. L. COLBY. Second edition, revised, 103 pp. crown 8vo. (_New York, 1902_) _net_ 5 0 =Pyrometry.= By C. R. DARLING. 60 illus. 200 pp. crown 8vo. (_1911_) _net_ 5 0 =Galvanised Iron=: its Manufacture and Uses. By J. DAVIES. 139 pp. 8vo. (_1899_) _net_ 5 0 =Management of Steel.= By G. EDE. Seventh edition, 216 pp. crown 8vo. (_1903_) 5 0 =The Frodair Handbook for Ironfounders.= 160 pp. 12mo. (_1910_) _net_ 2 0 =Cupola Furnace.= A practical treatise on the Construction and Management of Foundry Cupolas. By E. KIRK. Third edition, 106 illus. 484 pp. demy 8vo. (_New York, 1910_) _net_ 15 0 =Practical Notes on Pipe Founding.= By J. W. MACFARLANE. 15 plates, 148 pp. 8vo. (_1888_) 12 6 =Atlas of Designs concerning Blast Furnace Practice.= By M. A. PAVLOFF. 127 plates, 14 in. by 10-1/2 in. oblong, sewed. (_1902_) _net_ 1 1 0 =Album of Drawings relating to the Manufacture of Open Hearth Steel.= By M. A. PAVLOFF. Part I. Open Hearth Furnaces. 52 plates, 14 in. by 10-1/2 in. oblong folio, in portfolio. (_1904_) _net_ 12 0 =Metallography Applied to Siderurgic Products.= By H. SAVOIA. Translated by R. G. CORBET. 94 illus. 180 pp. crown 8vo. (_1910_) _net_ 4 6 =Modern Foundry Practice.= Including revised subject matter and tables from SPRETSON'S "Casting and Founding." By J. SHARP. Second edition, New impression, 272 illus. 759 pp. 8vo. (_1911_) _net_ 1 1 0 =Roll Turning for Sections in Steel and Iron.= By A. SPENCER. Second edition, 78 plates, 4to. (_1894_) 1 10 0 METRIC TABLES. =French Measure and English Equivalents.= By J. BROOK. Second edition, 80 pp. fcap. 32mo, roan. (_1906_) _net_ 1 0 =A Dictionary of Metric and other useful Measures.= By L. CLARK. 113 pp. 8vo. (_1891_) 6 0 =English Weights, with their Equivalents in kilogrammes.= By F. W. A. LOGAN. 96 pp. fcap. 32mo, roan. (_1906_) _net_ 1 0 =Metric Weights with English Equivalents.= By H. P. MCCARTNEY. 84 pp. fcap. 32mo, roan. (_1907_) _net_ 1 0 =Metric Tables.= By Sir G. L. MOLESWORTH. Fourth edition, 95 pp. royal 32mo. (_1909_) _net_ 2 0 =Tables for Setting out Curves= from 200 metres to 4000 metres by tangential angles. By H. WILLIAMSON. 4 illus. 60 pp. 18mo. (_1908_) _net_ 2 0 MINERALOGY AND MINING. =Rock Blasting.= By G. G. ANDRE. 12 plates and 56 illus. in text, 202 pp. 8vo. (_1878_) 5 0 =Winding Plants for Great Depths.= By H. C. BEHR. In two parts. 8vo, sewed. (_1902_) _net_ 2 2 0 =Practical Treatise on Hydraulic Mining in California.= By A. J. BOWIE, Jun. Tenth edition, 73 illus. 313 pp. royal 8vo. (_New York, 1905_) _net_ 1 1 0 =Tables for the Determination of Common Rocks.= By O. BOWLES. 64 pp. 18mo, boards. (VAN NOSTRAND SERIES, No. 125.) (_New York, 1910_) _net_ 2 0 =Manual of Assaying Gold, Silver, Copper and Lead Ores.= By W. L. BROWN. Twelfth edition, 132 illus. 589 pp. crown 8vo. (_New York, 1907_) _net_ 10 6 =Fire Assaying.= By E. W. BUSKETT. 69 illus. 105 pp. crown 8vo. (_New York, 1907_) _net_ 4 6 =Tin=: Describing the Chief Methods of Mining, Dressing, etc. By A. G. CHARLETON. 15 plates, 83 pp. crown 8vo. (_1884_) 12 6 =Gold Mining and Milling= in Western Australia, with Notes upon Telluride Treatment, Costs and Mining Practice in other Fields. By A. G. CHARLETON. 82 illus. and numerous plans and tables, 648 pp. super-royal 8vo. (_1903_) _net_ 1 5 0 =Miners' Geology and Prospectors' Guide.= By G. A. CORDER. 29 plates, 224 pp. crown 8vo. (_1907_) _net_ 5 0 =Blasting of Rock in Mines, Quarries, Tunnels, etc.= By A. W. and Z. W. DAW. Second edition, 90 illus. 316 pp. demy 8vo. (_1909_) _net_ 15 0 =Handbook of Mineralogy=; determination and description of Minerals found in the United States. By J. C. FOYE. 180 pp. 18mo, boards. (_New York, 1886_) _net_ 2 0 =Our Coal Resources= at the End of the Nineteenth Century. By Prof. E. HULL. 157 pp. demy 8vo. (_1897_) 6 0 =Hydraulic Gold Miners' Manual.= By T. S. G. KIRKPATRICK, Second edition, 12 illus. 46 pp. crown 8vo. (_1897_) 4 0 =Economic Mining.= By C. G. W. LOCK. 175 illus. 680 pp. 8vo. (_1895_) _net_ 10 6 =Gold Milling=: Principles and Practice. By C. G. W. LOCK. 200 illus. 850 pp. demy 8vo. (_1901_) _net_ 1 1 0 =Mining and Ore-Dressing Machinery.= By C. G. W. LOCK. 639 illus. 466 pp. super-royal 4to. (_1890_) 1 5 0 =Miners' Pocket Book.= By C. G. W. LOCK. Fifth edition, 233 illus. 624 pp. fcap. 8vo, leather, gilt edges. (_1908_) _net_ 10 6 =Chemistry, Properties and Tests of Precious Stones.= By J. MASTIN. 114 pp. fcap. 16mo, limp leather, gilt top. (_1911_) _net_ 2 6 =Tests for Ores, Minerals and Metals of Commercial Value.= By R. L. MCMECHEN. 152 pp. 12mo. (_New York, 1907_) _net_ 5 6 =Practical Handbook for the Working Miner and Prospector=, and the Mining Investor. By J. A. MILLER. 34 illus. 234 pp. crown 8vo. (_1897_) 7 6 =Theory and Practice of Centrifugal Ventilating Machines.= By D. MURGUE. 7 illus. 81 pp. 8vo. (_1883_) 5 0 =Examples of Coal Mining Plant.= By J. POVEY-HARPER. Second edition, 40 plates, 26 in. by 20 in. (_1895_) _net_ 4 4 0 =Examples of Coal Mining Plant, Second Series.= By J. POVEY-HARPER. 10 plates, 26 in. by 20 in. (_1902_) _net_ 1 12 6 MODELS AND MODEL MAKING. =How to Build a Model Yacht.= By H. FISHER. Numerous illustrations, 50 pp. 4to. (_New York, 1902_) _net_ 4 6 =Model Engines and Small Boats.= By N. M. HOPKINS. 50 illus. viii + 74 pp. crown 8vo. (_New York, 1898_) _net_ 5 9 =The Gyroscope, an Experimental Study.= By V. E. JOHNSON. 34 illus. 40 pp. crown 8vo, limp. (S. & C. SERIES, No. 22.) (_1911_) _net_ 1 6 =The Model Vaudeville Theatre.= By N. H. SCHNEIDER. 34 illus. 90 pp. crown 8vo, limp. (S. & C. SERIES, No. 15.) (_New York, 1910_) 1 6 =Electric Toy-Making.= By T. O. SLOANE. Fifteenth edition, 70 illus. 183 pp. crown 8vo. (_New York, 1903_) _net_ 4 6 =Model Steam Engine Design.= By R. M. DE VIGNIER. 34 illus. 94 pp. crown 8vo, limp. (S. & C. SERIES, No. 9.) (_New York, 1907_) _net_ 1 6 =Small Engines and Boilers.= By E. P. WATSON. 33 illus. viii + 108 pp. crown 8vo. (_New York, 1899_) _net_ 5 6 ORGANISATION. ACCOUNTS, CONTRACTS AND MANAGEMENT. =Organisation of Gold Mining Business=, with Specimens of the Departmental Report Books and the Account Books. By NICOL BROWN. Second edition, 220 pp. fcap. folio. (_1903_) _net_ 1 5 0 =Cost Keeping and Management Engineering.= A Treatise for those engaged in Engineering Construction. By H. P. GILLETTE and R. T. DANA. 184 illus. 346 pp. 8vo. (_New York, 1909_) _net_ 15 0 =Manual of Engineering Specifications= and Contracts. By L. M. HAUPT. Eighth edition, 338 pp. 8vo. (_New York, 1900_) _net_ 12 6 =Handbook on Railway Stores Management.= By W. O. KEMPTHORNE. 268 pp. demy 8vo. (_1907_) _net_ 10 6 =Depreciation of Factories=, Municipal, and Industrial Undertakings, and their Valuation. By E. MATHESON. Fourth edition, 230 pp. 8vo. (_1910_) _net_ 10 6 =Aid Book to Engineering Enterprise.= By E. MATHESON. Third edition, 916 pp. 8vo, buckram. (_1898_) 1 4 0 =Office Management.= A handbook for Architects and Civil Engineers. By W. KAYE PARRY. New impression, 187 pp. medium 8vo. (_1908_) _net_ 5 0 =Commercial Organisation of Engineering Factories.= By H. SPENCER. 92 illus. 221 pp. 8vo. (_1907_) _net_ 10 6 PHYSICS. COLOUR, HEAT AND EXPERIMENTAL SCIENCE. =The Entropy Diagram= and its Applications. By M. J. BOULVIN. 38 illus. 82 pp. demy 8vo. (_1898_) 5 0 =Physical Problems and their Solution.= By A. BOURGOUGNON. 224 pp. 18mo, boards. (_New York, 1897_) _net_ 2 0 =Heat for Engineers.= By C. R. DARLING. Second edition, 110 illus. 430 pp. 8vo. (FINSBURY TECHNICAL MANUAL.) (_1912_) _net_ 12 6 =The Colourist.= A method of determining colour harmony. By J. A. H. HATT. 2 coloured plates, 80 pp. 8vo. (_New York, 1908_) _net_ 6 6 =Engineering Thermodynamics.= By C. F. HIRSCHFELD. 22 illus. 157 pp. 18mo, boards. (_New York, 1907_) _net_ 2 0 =Experimental Science=: Elementary, Practical and Experimental Physics. By G. M. HOPKINS. Twenty-third edition, 920 illus. 1100 pp. large 8vo. (_New York, 1902_) _net_ 1 1 0 =Reform in Chemical and Physical Calculations.= By C. J. T. HANSSEN. Demy 4to. (_1897_) _net_ 6 6 =Introduction to the Study of Colour Phenomena.= By J. W. LOVIBOND. 10 hand coloured plates, 48 pp. 8vo. (_1905_) _net_ 5 0 =Practical Laws and Data on the Condensation of Steam in Bare Pipes=; to which is added a Translation of PECLET'S Theory and Experiments on the Transmission of Heat through Insulating Materials. By C. P. PAULDING. 184 illus. 102 pp. demy 8vo. (_New York, 1904_) _net_ 8 6 =The Energy Chart.= Practical application to reciprocating steam-engines. By Captain H. R. SANKEY. 157 illus. 170 pp. 8vo. (_1907_) _net_ 7 6 PRICE BOOKS. =The Mechanical Engineers' Price Book, 1912.= By G. BROOKS. 176 pp. pocket size (6-1/2 in. by 3-3/4 in. by 1/2 in. thick), leather cloth, with rounded corners. (_1912_) _net_ 4 0 =Approximate Estimates.= By T. E. COLEMAN. Third edition, 481 pp. oblong 32mo, leather. (_1907_) _net_ 5 0 =The Civil Engineers' Cost Book.= By MAJOR T. E. COLEMAN. xii. + 289 pp. pocket size (6-1/2 in. by 3-3/4 in.), leather cloth. (_1912_) _net_ 5 0 =Railway Stores Price Book.= By W. O. KEMPTHORNE. 500 pp. demy 8vo. (_1909_) _net_ 10 6 =Handbook of Cost Data for Contractors and Engineers.= By H. P. GILLETTE. 1854 pp. cr. 8vo, leather, gilt edges. (_New York, 1910_) _net_ 1 1 0 =Spons' Architects' and Builders' Pocket Price-Book and Diary, 1912.= Edited by CLYDE YOUNG. Revised by STANFORD M. BROOKS. Illustrated, 239 pp. green leather cloth. With Diary showing a week at an opening. (Size 6-1/2 in. by 3-3/4 in. by 1/2 in. thick). Issued annually _net_ 2 6 RAILWAY ENGINEERING AND MANAGEMENT. =Practical Hints to Young Engineers Employed on Indian Railways.= By A. W. C. ADDIS. 14 illus. 154 pp. 12mo. (_1910_) _net_ 3 6 =Field and Office Tables=, specially applicable to Railroads. By C. F. ALLEN. 293 pp. 16mo, leather. (_New York, 1903_) _net_ 8 6 =Up-to-date Air Brake Catechism.= By R. H. BLACKALL. Twenty-third edit. 5 coloured plates, 96 illus. 305 pp. crown 8vo. (_New York, 1908_) _net_ 8 6 =Prevention of Railroad Accidents, or Safety in Railroading.= By GEO. BRADSHAW. 64 illus. 173 pp. square crown 8vo. (_New York, 1912_) _net_ 2 6 =Simple and Automatic Vacuum Brakes.= By C. BRIGGS, G.N.R. 11 plates, 8vo. (_1892_) 4 0 =Notes on Permanent-way Material=, Plate-laying, ad Points and Crossings. By W. H. COLE. Sixth edition, revised, 44 illus. in 39 plates, 203 pp. crown 8vo. (_1912_) _net_ 7 6 =Statistical Tables of the Working of Railways= in various countries up to the year 1904. By J. D. DIACOMIDIS. Second edition, 84 pp. small folio, sewed. (_1906_) _net_ 16 0 =Locomotive Breakdowns=, Emergencies and their Remedies. By GEO. L. FOWLER, M.E., and W. W. WOOD. Fifth edition, 92 illus. 266 pp. 12mo. (_New York, 1911_) _net_ 4 6 =Permanent-Way Diagrams.= By F. H. FRERE. Mounted on linen in cloth covers. (_1908_) _net_ 3 0 =Formulæ for Railway Crossings and Switches.= By J. GLOVER. 9 illus. 28 pp. royal 32mo. (_1896_) 2 6 =Setting out of Tube Railways.= By G. M. HALDEN. 9 plates, 46 illus. 68 pp. crown 4to. (_1907_) _net_ 10 6 =Railway Engineering, Mechanical and Electrical.= By J. W. C. HALDANE. New edition, 141 illus. xx + 583 pp. 8vo. (_1908_) 15 0 =The Construction of the Modern Locomotive.= By G. HUGHES. 300 illus. 261 pp. 8vo. (_1894_) 9 0 =Practical Hints for Light Railways= at Home and Abroad. By F. R. JOHNSON. 6 plates, 31 pp. crown 8vo. (_1896_) 2 6 =Handbook on Railway Stores Management.= By W. O. KEMPTHORNE. 268 pp. demy 8vo. (_1907_) _net_ 10 6 =Railway Stores Price Book.= By W. O. KEMPTHORNE. 487 pp. demy 8vo. (_1909_) _net_ 10 6 =Railroad Location Surveys and Estimates.= By F. LAVIS. 68 illus. 270 pp. 8vo. (_New York, 1906_) _net_ 12 6 =Pioneering.= By F. SHELFORD. Illustrated, 88 pp. crown 8vo. (_1909_) _net_ 3 0 =Handbook on Railway Surveying= for Students and Junior Engineers. By B. STEWART. 55 illus. 98 pp. crown 8vo. (_1909_) _net_ 2 6 =Modern British Locomotives.= By A. T. TAYLOR. 100 diagrams of principal dimensions, 118 pp. oblong 8vo. (_1907_) _net_ 4 6 =Locomotive Slide Valve Setting.= By C. E. TULLY. Illustrated, 18mo _net_ 1 0 =The Railway Goods Station.= By F. W. WEST. 23 illus., xv + 192 pp. crown 8vo. (_1912_) _net_ 4 6 =The Walschaert Locomotive Valve Gear.= By W. W. WOOD. 4 plates and set of movable cardboard working models of the valves, 193 pp. crown 8vo. (_New York, 1907_) _net_ 6 6 =The Westinghouse E.T. Air-Brake Instruction Pocket Book.= By W. W. WOOD. 48 illus. including many coloured plates, 242 pp. crown 8vo. (_New York, 1909_) _net_ 8 6 SANITATION, PUBLIC HEALTH AND MUNICIPAL ENGINEERING. =Sewers and Drains for Populous Districts.= By J. W. ADAMS. Ninth edition, 81 illus. 236 pp. 8vo. (_New York, 1902_) _net_ 10 6 =Engineering Work in Public Buildings.= By R. O. ALLSOP. 77 illus. ix + 158 pp. demy 4to. (_1912_) _net_ 12 6 =Public Abattoirs=, their Planning, Design and Equipment. By R. S. AYLING. 33 plates, 100 pp. demy 4to. (_1908_) _net_ 8 6 =Sewage Purification.= By E. BAILEY-DENTON. 8 plates, 44 pp. 8vo. (_1896_) 5 0 =Water Supply and Sewerage of Country Mansions= and Estates. By E. BAILEY-DENTON. 76 pp. crown 8vo. (_1901_) _net_ 2 6 =Sewerage and Sewage Purification.= By M. N. BAKER. Second edition, 144 pp. 18mo, boards. (_New York, 1905_) _net_ 2 0 =Sewage Irrigation by Farmers.= By R. W. P. BIRCH. 8vo, sewed. (_1878_) 2 6 =Sanitary House Drainage=, its Principles and Practice. By T. E. COLEMAN. 98 illus. 206 pp. crown 8vo. (_1896_) 6 0 =Stable Sanitation and Construction.= By T. E. COLEMAN. 183 illus. 226 pp. crown 8vo. (_1897_) 6 0 =Public Institutions=, their Engineering, Sanitary and other Appliances. By F. COLYER. 231 pp. 8vo. (_1889_) _net_ 2 0 =Discharge of Pipes and Culverts.= By P. M. CROSTHWAITE. Large folding sheet in case _net_ 2 6 =A Complete and Practical Treatise on Plumbing and Sanitation: Hot Water Supply, Warming and Ventilation=, Steam Cooking, Gas, Electric Light, Bells, etc., with a complete Schedule of Prices of Plumber's Work. By G. B. DAVIS and F. DYE. 2 vols. 637 illus. and 21 folding plates, 830 pp. 4to, cloth. (_1899_) _net_ 1 10 0 =Standard Practical Plumbing.= By P. J. DAVIES. Vol. I. Fourth edition, 768 illus. 355 pp. royal 8vo. (_1905_) _net_ 7 6 Vol. II. Second edition, 953 illus. 805 pp. (_1905_) _net_ 10 6 Vol. III. 313 illus. 204 pp. (_1905_) _net_ 5 0 =Conservancy, or Dry Sanitation versus Water Carriage.= By J. DONKIN. 7 plates, 33 pp. 8vo, sewed. (_1906_) _net_ 1 0 =Sewage Disposal Works=, their Design and Construction. By W. C. EASDALE. With 160 illus. 264 pp. demy 8vo. (_1910_) _net_ 10 6 =House Drainage and Sanitary Plumbing.= By W. P. GERHARD. Tenth edition, 6 illus. 231 pp. 18mo, boards. (_New York, 1902_) _net_ 2 0 =Central Station Heating.= By B. T. GIFFORD. 37 illus. 208 pp. 8vo, leather. (_New York, 1912_) _net_ 17 0 =Housing and Town Planning Conference.= Report of Conference held by the INSTITUTION OF MUNICIPAL AND COUNTY ENGINEERS. Edited by T. COLE, _Secretary_. 30 plates, 240 pp. demy 8vo. (_1911_) _net_ 10 6 =Engineering Work in Towns and Cities.= By E. MCCULLOCH. 44 illus. 502 pp. crown 8vo. (_New York, 1908_) _net_ 12 6 =The Treatment of Septic Sewage.= By G. W. RAFTER. 137 pp. 18mo, boards. (_New York, 1904_) _net_ 2 0 =Reports and Investigations on Sewer Air= and Sewer Ventilation. By R. H. REEVES. 8vo, sewed. (_1894_) 1 0 =The Law and Practice of Paving= Private Street Works. By W. SPINKS. Fourth edition, 256 pp. 8vo. (_1904_) _net_ 12 6 STRUCTURAL DESIGN. (_See_ BRIDGES AND ROOFS.) TELEGRAPH CODES. =New Business Code.= 320 pp. narrow 8vo. (Size 4-3/4 in. by 7-3/4 in. and 1/2 in. thick, and weight 10 oz.) (_New York, 1909_) _net_ 1 1 0 =Miners' and Smelters' Code= (formerly issued as the =Master Telegraph Code=). 448 pp. 8vo, limp leather, weight 14 oz. (_New York, 1899_) _net_ 2 10 0 =Billionaire Phrase Code=, containing over two million sentences coded in single words. 56 pp. 8vo, leather. (_New York, 1908_) _net_ 6 6 WARMING AND VENTILATION. =Heat for Engineers.= By C. R. DARLING. Second edition, 110 illus. 430 pp. 8vo. (FINSBURY TECHNICAL MANUAL.) (_1912_) _net_ 12 6 =Hot Water Supply.= By F. DYE. Fifth edition. New impression, 48 ill. 86 pp. cr. 8vo. (_1910_) _net_ 3 0 =A Practical Treatise upon Steam Heating.= By F. DYE. 129 illus. 246 pp. demy 8vo. (_1901_) _net_ 10 0 =Practical Treatise on Warming Buildings by Hot Water.= By F. DYE. 192 illus. 319 pp. 8vo. cloth. (_1905_) _net_ 8 6 =Central Station Heating.= By B. T. GIFFORD. 37 illus. 208 pp. demy 8vo, leather. (_New York, 1912_) _net_ 17 0 =Charts for Low Pressure Steam Heating.= By J. H. KINEALY. Small folio. (_New York_) 4 6 =Formulæ and Tables for Heating.= By J. H. KINEALY. 18 illus. 53 pp. 8vo. (_New York, 1899_) 3 6 =Centrifugal Fans.= By J. H. KINEALY. 33 illus. 206 pp. fcap. 8vo, leather. (_New York, 1905_) _net_ 12 6 =Mechanical Draft.= By J. H. KINEALY. 27 original tables and 13 plates, 142 pp. crown 8vo. (_New York, 1906_) _net_ 8 6 =Theory and Practice of Centrifugal Ventilating Machines.= By D. MURGUE. 7 illus. 81 pp. 8vo. (_1883_) 5 0 =Mechanics of Ventilation.= By G. W. RAFTER. Second edition, 143 pp. 18mo, boards. (_New York, 1896_) _net_ 2 0 =Principles of Heating.= By W. G. SNOW. 62 illus. 161 pp. 8vo. (_New York, 1907_) _net_ 8 6 =Furnace Heating.= By W. G. SNOW. Fourth edition, 52 illus. 216 pp. 8vo. (_New York, 1909_) _net_ 6 6 =Ventilation of Buildings.= By W. G. SNOW and T. NOLAN. 83 pp. 18mo, boards. (_New York, 1906_) _net_ 2 0 =Heating Engineers' Quantities.= By W. L. WHITE and G. M. WHITE. 4 plates, 33 pp. folio. (_1910_) _net_ 10 6 WATER SUPPLY. (_See also_ HYDRAULICS.) =Potable Water and Methods of Testing Impurities.= By M. N. BAKER. 97 pp. 18mo, boards. (_New York, 1905_) _net_ 2 0 =Manual of Hydrology.= By N. BEARDMORE. New impression, 18 plates, 384 pp. 8vo. (_1906_) _net_ 10 6 =Boiler Waters=, Scale, Corrosion and Fouling. By W. W. CHRISTIE. 77 illus. 235 pp. 8vo, cloth. (_New York, 1907_) _net_ 12 6 =Water Softening and Purification.= By H. COLLET. Second edition, 6 illus. 170 pp. crown 8vo. (_1908_) _net_ 5 0 =Treatise on Water Supply=, Drainage and Sanitary Appliances of Residences. By F. COLYER. 100 pp. crown 8vo. (_1899_) _net_ 1 6 =Purification of Public Water Supplies.= By J. W. HILL. 314 pp. 8vo. (_New York, 1898_) 10 6 =Well Boring= for Water, Brine and Oil. By C. ISLER. Second edition, 105 illus. 296 pp. 8vo. (_1911_) _net_ 10 6 =Method of Measuring Liquids Flowing through Pipes by means of Meters of Small Calibre.= By Prof. G. LANGE. 1 plate, 16 pp. 8vo, sewed _net_ 0 6 =On Artificial Underground Water.= By G. RICHERT. 16 illus. 33 pp. 8vo, sewed. (_1900_) _net_ 1 6 =Notes on Water Supply= in new Countries. By F. W. STONE. 18 plates, 42 pp. crown 8vo. (_1888_) 5 0 =The Principles of Waterworks Engineering.= By J. H. T. TUDSBERY and A. W. BRIGHTMORE. Third edition, 13 folding plates, 130 illus. 447 pp. demy 8vo. (_1905_) _net_ 11 0 WORKSHOP PRACTICE. FOR ART WORKERS AND MECHANICS. =A Handbook for Apprenticed Machinists.= By O. J. BEALE. Second edition, 89 illus., 141 pp. 16mo. (_New York, 1901_) _net_ 2 6 =Practice of Hand Turning.= By F. CAMPIN. Third edition, 99 illus. 307 pp. crown 8vo. (_1883_) 3 6 =Artistic Leather Work.= By E. ELLIN CARTER. 6 plates and 21 illus. in text, xii + 51 pp. crown 8vo. (_1912_) _net_ 2 6 =Calculation of Change Wheels for Screw Cutting on Lathes.= By D. DE VRIES. 46 illus. 83 pp. 8vo. (_1908_) _net_ 3 0 =Milling Machines and Milling Practice.= By D. DE VRIES. With 536 illus. 464 pp. medium 8vo. (_1910_) _net_ 14 0 =French-Polishers' Manual.= By a French-Polisher. New impression, 31 pp. royal 32mo, sewed. (_1912_) _net_ 0 6 =Art of Copper-Smithing.= By J. FULLER. Fourth edition, 483 illus. 319 pp. royal 8vo. (_New York, 1911_) _net_ 12 6 =Hand Forging and Wrought Iron Ornamental Ironwork.= By T. F. GOOGERTY. 122 illus. 197 pp. crown 8vo. (_New York, 1912_) _net_ 4 6 =Saw Filing and Management of Saws.= By R. GRIMSHAW. New edition, 81 illus. 16mo. (_New York, 1906_) _net_ 4 6 =Paint and Colour Mixing.= By A. S. JENNINGS. Fourth edition. 14 coloured plates, 190 pp. 8vo. (_1910_) _net_ 5 0 =The Mechanician=: a Treatise on the Construction and Manipulation of Tools. By C. KNIGHT. Fifth edition, 96 plates, 397 pp. 4to. (_1897_) 18 0 =Turner's and Fitter's Pocket Book.= By J. LA NICCA. 18mo, sewed 0 6 =Tables for Engineers and Mechanics=, giving the values of the different trains of wheels required to produce Screws of any pitch. By LORD LINDSAY. Second edition, royal 8vo, oblong. 2 0 =Screw-cutting Tables.= By W. A. MARTIN. Seventh edition, royal 8vo, oblong _net_ 1 0 =Metal Plate Work=, its Patterns and their Geometry, for the use of Tin, Iron and Zinc Plate Workers. By C. T. MILLIS. Fourth edition, 280 diagrams, 470 pp. crown 8vo. (_1906_) 9 0 =The Practical Handbook of Smithing and Forging.= Engineers' and General Smiths' Work. By T. MOORE. New impression, 401 illus. 248 pp. crown 8vo. (_1912_) _net_ 5 0 =Modern Machine Shop Construction=, equipment and management. By O. E. PERRIGO. 208 illus. 343 pp. crown 4to. (_New York, 1906_) _net_ 1 1 0 =Turner's Handbook on Screw-cutting=, Coning, etc. By W. PRICE. New impression, fcap. 8vo. (_1912_) _net_ 0 6 =Introduction to Eccentric Spiral Turning.= By H. C. ROBINSON. 12 plates, 23 illus. 48 pp. 8vo. (_1906_) _net_ 4 6 =Manual of Instruction in Hard Soldering.= By H. ROWELL. Sixth edition, 7 illus. 66 pp. crown 8vo. (_New York, 1910_) _net_ 3 0 =Forging, Stamping, and General Smithing.= By B. SAUNDERS. 728 illus. ix + 428 pp. demy 8vo. (_1912_) _net_ 11 0 =Pocket Book on Boilermaking, Shipbuilding=, and the Steel and Iron Trades in General. By M. J. SEXTON. Sixth edition, New impression, 85 illus. 319 pp. royal 32mo, roan, gilt edges. (_1912_) _net_ 5 0 =Power and its Transmission.= A Practical Handbook for the Factory and Works Manager. By T. A. SMITH. 76 pp. fcap. 8vo. (_1910_) _net_ 2 0 =Spons' Mechanics' Own Book=: A Manual for Handicraftsmen and Amateurs. Sixth edition, New impression, 1430 illus. 720 pp. demy 8vo. (_1912_) 6 0 Ditto ditto half French morocco 7 6 =Spons' Workshop Receipts for Manufacturers, Mechanics and Scientific Amateurs.= New and thoroughly revised edition, crown 8vo. (_1909_) _each net_ 3 0 Vol. I. ACETYLENE LIGHTING _to_ DRYING. 223 illus. 532 pp. Vol. II. DYEING _to_ JAPANNING. 259 illus. 540 pp. Vol. III. JOINTING PIPES _to_ PUMPS. 257 illus. 528 pp. Vol. IV. RAINWATER SEPARATORS _to_ WIRE ROPES. 321 illus. 540 pp. =Gauges at a Glance.= By T. TAYLOR. Second edition, post 8vo, oblong, with tape converter. (_1900_) _net_ 5 0 =Simple Soldering=, both Hard and Soft. By E. THATCHER. 52 illus. 76 pp. crown 8vo. (S. & C. SERIES, No. 18.) (_New York, 1910_) _net_ 1 6 =The Modern Machinist.= By J. T. USHER. Fifth edition. 257 illus. 322 pp. 8vo. (_New York, 1904_) _net_ 10 6 =Knots, Splices, and Rope-Work.= By A. H. VERRILL. 148 illus. 102 pp. 12mo. (_New York, 1912_) _net_ 3 0 =Practical Wood Carving.= By C. J. WOODSEND. 108 illus. 86 pp. 8vo. (_New York, 1897_) _net_ 4 6 =American Tool Making= and Interchangeable Manufacturing. By J. W. Woodworth. 600 illus. 544 pp. demy 8vo. (_New York, 1905_) _net_ 17 0 USEFUL TABLES. _See also_ CURVE TABLES, EARTHWORK, FOREIGN EXCHANGE, INTEREST TABLES, LOGARITHMS, _and_ METRIC TABLES. =Weights and Measurements of Sheet Lead.= By J. ALEXANDER. 32mo, roan _net_ 1 6 =Barlow's Tables of Squares=, Cubes, Square Roots, Cube Roots and Reciprocals, of all Integer Numbers from 1 to 10,000. Crown 8vo, leather cloth _net_ 4 0 =Tables of Squares.= Of every foot, inch and 1/16 of an inch from 1/16 of an inch to 50 feet. By E. E. BUCHANAN. Eleventh edition, 102 pp. 16mo, limp. (_New York, 1912_) _net_ 4 6 =Land Area Tables.= By W. CODD. On sheet mounted on linen, in cloth case with explanatory pamphlet. (_1910_) 3 6 =Tables of some of the Principal Speeds= occurring in Mechanical Engineering, expressed in Metres per second. By P. KEERAYEFF. 18mo, sewed _net_ 0 6 =Calculating Scale.= A Substitute for the Slide Rule. By W. KNOWLES. Crown 8vo, leather _net_ 1 0 =Planimeter Areas.= Multipliers for various scales. By H. B. MOLESWORTH. Folding sheet in cloth case _net_ 1 0 =Tables of Seamless Copper Tubes.= By I. O'TOOLE. 69 pp. oblong fcap. 8vo. (_1908_) _net_ 3 6 =Steel Bar and Plate Tables.= Giving Weight per Lineal Foot of all sizes of =L= and =T= Bars, Flat Bars, Plates, Square, and Round Bars. By E. READ. On large folding card. (_1911_) _net_ 1 0 =Rownson's Iron Merchants' Tables= and Memoranda, Weights and Measures. 86 pp. 32mo, leather 3 6 =Spons' Tables and Memoranda for Engineers.= By J. T. HURST, C.E. Twelfth edition, 278 pp. 64mo, roan, gilt edges. (_1907_) _net_ 1 0 Ditto ditto in celluloid case _net_ 1 6 =Optical Tables and Data=, for the use of Opticians. By Prof. S. P. THOMPSON. Second edition, 130 pp. oblong 8vo. 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38739	----	SERIAL PUBLICATIONS OF THE SMITHSONIAN INSTITUTION The emphasis upon publications as a means of diffusing knowledge was expressed by the first Secretary of the Smithsonian Institution. In his formal plan for the Institution, Joseph Henry articulated a program that included the following statement: "It is proposed to publish a series of reports, giving an account of the new discoveries in science, and of the changes made from year to year in all branches of knowledge not strictly professional." This keynote of basic research has been adhered to over the years in the issuance of thousands of titles in serial publications under the Smithsonian imprint, commencing with _Smithsonian Contributions to Knowledge_ in 1848 and continuing with the following active series: _Smithsonian Annals of Flight_ _Smithsonian Contributions to Anthropology_ _Smithsonian Contributions to Astrophysics_ _Smithsonian Contributions to Botany_ _Smithsonian Contributions to the Earth Sciences_ _Smithsonian Contributions to Paleobiology_ _Smithsonian Contributions to Zoology_ _Smithsonian Studies in History and Technology_ In these series, the Institution publishes original articles and monographs dealing with the research and collections of its several museums and offices and of professional colleagues at other institutions of learning. These papers report newly acquired facts, synoptic interpretations of data, or original theory in specialized fields. Each publication is distributed by mailing lists to libraries, laboratories, institutes, and interested specialists throughout the world. Individual copies may be obtained from the Smithsonian Institution Press as long as stocks are available. S. DILLON RIPLEY _Secretary_ Smithsonian Institution The Wright Brothers' Engines And Their Design [Illustration: Kitty Hawk Flyer with original Wright engine poised on launching rail at Kill Devil Hill, near Kitty Hawk, North Carolina, 24 November 1903, the month before the Wrights achieved man's first powered and controlled flight in a heavier-than-air craft.] [Illustration: Reproduction of the first engine, built by Pratt & Whitney, as displayed in Wright Brothers National Memorial at Kitty Hawk. Engine is mounted in a reproduction of the Wrights' Flyer built by the National Capital Section of the Institute of the Aeronautical Sciences (now the American Institute of Aeronautics and Astronautics). Engine and plane were donated in 1963 to the National Park Service Cape Hatteras National Seashore.] SMITHSONIAN ANNALS OF FLIGHT * NUMBER 5 SMITHSONIAN INSTITUTION * NATIONAL AIR AND SPACE MUSEUM The Wright Brothers' Engines And Their Design _Leonard S. Hobbs_ SMITHSONIAN INSTITUTION PRESS CITY OF WASHINGTON 1971 _Smithsonian Annals of Flight_ Numbers 1-4 constitute volume one of _Smithsonian Annals of Flight_. Subsequent numbers will bear no volume designation, which has been dropped. The following earlier numbers of _Smithsonian Annals of Flight_ are available from the Superintendent of Documents as indicated below: 1. The First Nonstop Coast-to-Coast Flight and the Historic T-2 Airplane, by Louis S. Casey. 1964. 90 pages, 43 figures, appendix, bibliography. Out of print. 2. The First Airplane Diesel Engine: Packard Model DR-980 of 1928, by Robert B. Meyer. 1964. 48 pages, 37 figures, appendix, bibliography. Price 60¢. 3. The Liberty Engine 1918-1942, by Philip S. Dickey. 1968. 110 pages, 20 figures, appendix, bibliography. Price 75¢. 4. Aircraft Propulsion: A Review of the Evolution of Aircraft Piston Engines, by C. Fayette Taylor. 1971 viii + 134 pages, 72 figures, appendix, bibliography of 601 items. Price $1.75. For sale by Superintendent of Documents, Government Printing Office Washington, D.C. 20402--Price 60 cents Foreword In this fifth number of _Smithsonian Annals of Flight_ Leonard S. Hobbs analyzes the original Wright _Kitty Hawk Flyer_ engine from the point of view of an aeronautical engineer whose long experience in the development of aircraft engines gives him unique insight into the problems confronting these remarkable brothers and the ingenious solutions they achieved. His review of these achievements also includes their later vertical 4-and 6-cylinder models designed and produced between 1903 and 1915. The career of Leonard S. (Luke) Hobbs spans the years that saw the maturing of the aircraft piston engine and then the transition from reciprocating power to the gas turbine engine. In 1920 he became a test engineer in the Power Plant Laboratory of the Army Air Service at McCook Field in Dayton, Ohio. There, and later as an engineer with the Stromberg Motor Devices Corporation, he specialized in aircraft engine carburetors and developed the basic float-type to the stage of utility where for the first time it provided normal operation during airplane evolutions, including inverted flight. Joining Pratt & Whitney Aircraft in 1927 as Research Engineer, Hobbs advanced to engineering manager in 1935 and in 1939 took over complete direction of its engineering. He was named vice president for engineering for all of United Aircraft in 1944, and was elected vice chairman of United Aircraft in 1956, serving in that capacity until his retirement in 1958. He remained a member of the board of directors until 1968. Those years saw the final development of Pratt & Whitney's extensive line of aircraft piston engines which were utilized by the United States and foreign air forces in large quantities and were prominent in the establishment of worldwide air transportation. In 1963 Hobbs was awarded the Collier Trophy for having directed the design and development of the J57 turbojet, the country's first such engine widely used in both military service and air transportation. He was an early fellow of the Institute of Aeronautical Sciences (later the American Institute of Aeronautics and Astronautics), served for many years on the Powerplant Committee of the National Advisory Committee for Aeronautics, and was the recipient of the Presidential Certificate of Merit. FRANK A. TAYLOR, _Acting Director_ _National Air and Space Museum_ _March 1970_ Contents Foreword v Acknowledgments ix The Beginnings 1 The Engine of the First Flight, 1903 9 The Engines With Which They Mastered the Art of Flying 29 The Four-Cylinder Vertical Demonstration Engine and the First Production Engine 34 The Eight-Cylinder Racing Engine 47 The Six-Cylinder Vertical Engine 49 Minor Design Details and Performance of the Wright Engines 57 Appendix 62 Characteristics of the Wright Flight Engines 62 The Wright Shop Engine 64 Bibliography 69 Index 71 Acknowledgments As is probably usual with most notes such as this, however short, before completion the author becomes indebted to so many people that it is not practical to record all the acknowledgments that should be made. This I regret extremely, for I am most appreciative of the assistance of the many who responded to my every request. The mere mention of the Wright name automatically opened almost every door and brought forth complete cooperation. I do not believe that in the history of the country there has been another scientist or engineer as admired and revered as they are. I must, however, name a few who gave substantially of their time and effort and without whose help this work would not be as complete as it is. Gilmoure N. Cole, A. L. Rockwell, and the late L. Morgan Porter were major contributors, the latter having made the calculations of the shaking forces, the volumetric efficiency, and the connecting rod characteristics of the 1903 engine. Louis P. Christman, who was responsible for the Smithsonian drawings of this engine and also supervised the reconstruction of the 1905 Wright airplane, supplied much information, including a great deal of the history of the early engines. Opie Chenoweth, one of the early students of the subject, was of much assistance; and I am indebted to R. V. Kerley for the major part of the data on the Wrights' shop engine. Also, I must express my great appreciation to the many organizations that cooperated so fully, and to all the people of these organizations and institutions who gave their assistance so freely. These include the following: Air Force Museum, Wright-Patterson Air Force Base, Ohio Carillon Park Museum, Dayton, Ohio Connecticut Aeronautical Historical Association, Hebron, Connecticut Fredrick C. Crawford Museum, Cleveland, Ohio Historical Department, Daimler Benz A. G., Stuttgart-Untertürkheim, West Germany Engineers Club, Dayton, Ohio Deutsches Museum, Munich, West Germany Educational and Musical Arts, Inc., Dayton, Ohio Henry Ford Museum, Dearborn, Michigan Franklin Institute, Philadelphia, Pennsylvania Howell Cheney Technical School, Manchester, Connecticut Library of Congress, Washington, D.C. Naval Air Systems Command, U.S. Navy, Washington, D.C. Science Museum, London, England Victoria and Albert Museum, London, England In particular, very extensive contributions were made by the Smithsonian Institution and by the United Aircraft Corporation through its Library, through the Pratt & Whitney Aircraft Division's entire Engineering Department and its Marketing and Product Support Departments, and through United Aircraft International. The Beginnings The general history of the flight engines used by the Wright Brothers is quite fascinating and fortunately rather well recorded.[1] The individual interested in obtaining a reasonably complete general story quickly is referred to three of the items listed in the short bibliography on page 69. The first, _The Papers of Wilbur and Orville Wright_, is a primary source edited by the authority on the Wright brothers, Marvin W. McFarland of the Library of Congress; a compact appendix to volume 2 of the _Papers_ contains most of the essential facts. This source is supplemented by the paper of Baker[2] and the accompanying comments by Chenoweth, presented at the National Aeronautics Meeting of the Society of Automotive Engineers on 17 April 1950. Aside from their excellence as history, these publications are outstanding for the manner in which those responsible demonstrate their competence and complete mastery of the sometimes complex technical part of the Wright story. [Footnote 1: An extensive bibliography, essentially as complete at this time as when it was compiled in the early 1950s, is given on pages 1240-1242 of volume 2 of _The Papers of Wilbur and Orville Wright_, 1953.] [Footnote 2: Max P. Baker was a technical adviser to the Wright estate and as such had complete access to all of the material it contained.] The consuming interest of the Wrights, of course, was in flight as such, and in their thinking the required power unit was of only secondary importance. However, regardless of their feeling about it, the unit was an integral part of their objective and, due to the prevailing circumstances, they very early found themselves in the aircraft engine business despite their inexperience. This business was carried on very successfully, against increasingly severe competition, until Orville Wright withdrew from commercial activity and dissolved the Wright Company. The time span covered approximately the twelve years from 1903 to 1915, during the first five years of which they designed and built for their own use several engines of three different experimental and demonstration designs. In the latter part of the period, they manufactured and sold engines commercially, and during this time they marketed three models, one of which was basically their last demonstration design. A special racing engine was also built and flown during this period. Accurate records are not available but altogether, they produced a total of something probably close to 200 engines of which they themselves took a small number for their various activities, including their school and flying exhibition work which at one time accounted for a very substantial part of their business. A similar lack of information concerning their competition, which expanded rapidly after the Wright's demonstrations, makes any comparisons a difficult task. The Wrights were meticulous about checking the actual performance of their engines but at that time ratings generally were seldom authenticated and even when different engines were tried in the same airplane the results usually were not measured with any accuracy or recorded with any permanency. There is evidence that the competition became effective enough to compel the complete redesign of their engine so that it was essentially a new model. For their initial experimentation the Wrights regarded gravity as not only their most reliable power source but also the one most economical and readily available, hence their concentration on gliding. They had correctly diagnosed the basic problem of flight to be that of control, the matter of the best wing shapes being inherently a simpler one which they would master by experiment, utilizing at first gravity and later a wind tunnel. Consequently, the acquisition of a powerplant intended for actual flight was considerably deferred. Nevertheless, they were continuously considering the power requirement and its problems. In his September 1901 lecture to the Western Society of Engineers, Wilbur Wright made two statements: "Men also know how to build engines and screws of sufficient lightness and power to drive these planes at sustaining speed"; and in conjunction with some figures he quoted of the required power and weight: "Such an engine is entirely practicable. Indeed, working motors of one-half this weight per horsepower [9 pounds per horsepower] have been constructed by several different builders." It is quite obvious that with their general knowledge and the experience they had acquired in designing and building a successful shop engine for their own use, they had no cause to doubt their ability to supply a suitable powerplant when the need arose. After the characteristics of the airframe had been settled, and the engine requirements delineated in rather detailed form, they had reached the point of decision on what they termed the motor problem. Only one major element had changed greatly since their previous consideration of the matter; they had arrived at the point where they not only needed a flight engine, they wanted it quickly. Nothing has been found that would indicate how much consideration they had given to forms of power for propulsion other than the choice they had apparently made quite early--the internal-combustion, four-stroke-cycle piston engine. Undoubtedly, steam was dismissed without being given much, if any, thought. On the face of it, the system was quite impractical for the size and kind of machine they planned; but it had been chosen by Maxim for his experiments,[3] and some thirty-five or forty years later a serious effort to produce an aviation engine utilizing steam was initiated by Lockheed. On the other hand internal-combustion two-stroke-cycle piston engines had been built and used successfully in a limited way. And since, at that time, it was probably not recognized that the maximum quantity of heat it is possible to dissipate imposed an inherent limitation on the power output of the internal-combustion engine, the two-stroke-cycle may have appeared to offer a higher output from a given engine size than the four-stroke-cycle could produce. Certainly, it would have seemed to promise much less torque variation for the same output, something that was of great importance to the Wrights. Against this, the poor scavenging efficiency of the two-stroke operation, and most probably its concurrent poor fuel economy, were always evident; and, moreover, at that time the majority of operating engines were four-stroke-cycle. Whatever their reasoning, they selected for their first powered flight the exact form of prime mover that continued to power the airplane until the advent of the aircraft gas turbine more than forty years later. [Footnote 3: In the 1890s the wealthy inventor Sir Hiram Stevens Maxim conducted an experiment of considerable magnitude with a flying machine that utilized a twin-cylinder compound steam powerplant. It was developed to the flight-test stage.] The indicated solution to their problem of obtaining the engine--and the engine that would seem by all odds most reliable--would have been to have a unit produced to their specifications by one of the best of the experienced engine builders, and to accomplish this, the most effective method would be to use the equivalent of a bid procedure. This they attempted, and sent out a letter of inquiry to a fairly large number of manufacturers. Although no copy of the letter is available, it is rather well established that it requested the price of an engine of certain limited specifications which would satisfy their flight requirements, but beyond this there is little in the record. A more thorough examination of the underlying fundamentals, however, discloses many weaknesses in the simple assumptions that made the choice of an experienced builder seem automatic. A maximum requirement limited to only one or two units offered little incentive to a manufacturer already successfully producing in his field, and the disadvantage of the limited quantity was only accentuated by the basic requirement for a technical performance in excess of any standard of the time. Certainly there was no promise of any future quantity business or any other substantial reward. Orville Wright many times stated that they had no desire to produce their own engine, but it is doubtful that they had any real faith in the buying procedure, for they made no attempt to follow up their first inquiries or to expand the original list. Whatever the reasoning, their judgment of the situation is obvious; they spent no time awaiting results from the letter but almost immediately started on the task of designing and building the engine themselves. Perhaps the generalities were not as governing as the two specific factors whose immediate importance were determining: cost and time. The Wrights no doubt realized that a specially designed, relatively high performance engine in very limited hand-built quantities would not only be an expensive purchased article but would also take considerable time to build, even under the most favorable circumstances. So the lack of response to their first approach did not have too much to do with their ultimate decision to undertake this task themselves. The question of the cost of the Wrights' powerplants is most intriguing, as is that of their entire accomplishment. No detailed figures of actual engine costs are in the record, and it is somewhat difficult to imagine just how they managed to conduct an operation requiring so much effort and such material resources, given the income available from their fairly small bicycle business. The only evidence bearing on this is a statement that the maximum income from this business averaged $3,000 a year,[4] which of course had to cover not only the airplane and engine but all personal and other expenses. Yet they always had spare engines and spare parts available; they seemingly had no trouble acquiring needed materials and supplies, both simple and complex; and they apparently never were hindered at any time by lack of cash or credit. The only mention of any concern about money is a statement by Wilbur Wright in a letter of 20 May 1908 when, about to sail for France for the first public demonstrations, he wrote: "This plan would put it to the touch quickly and also help ward off an approaching financial stringency which has worried me very much for several months." It is a remarkable record in the economical use of money, considering all they had done up to that time. The myth that they had been aided by the earnings of their sister Katherine as a school teacher was demolished long ago. [Footnote 4: Fred C. Kelly, _Miracle at Kitty Hawk_, 1951.] The decision to build the engine themselves added one more requirement, and possibly to some extent a restriction, to the design. They undoubtedly desired to machine as much of the engine as possible in their own shop, and the very limited equipment they had would affect the variety of features and constructions that could be utilized, although experienced machine shops with sophisticated equipment were available in Dayton and it is obvious that the Wrights intended to, and did, utilize these when necessary. The use of their own equipment, of course, guaranteed that the parts they could handle themselves would be more expeditiously produced. They commenced work on the design and construction shortly before Christmas in 1902. The subject of drawings of the engine is interesting, not only as history but also because it presents several mysteries. Taylor[5] stated, "We didn't make any drawings. One of us would sketch out the part we were talking about on a piece of scrap paper ..." Obviously somewhere in the operation some dimensions were added, for the design in many places required quite accurate machining. Orville Wright's diary of 1904 has the entry, "Took old engine apart to get measurements for making new engine." Finally, no Wright drawings of the original engine have been seen by anyone connected with the history or with the Wright estate. In the estate were two drawings (now at the Franklin Institute), on heavy brown wrapping paper, relating to one of the two very similar later engines built in 1904; one is of a cylinder and connecting rod, the other is an end view of the engine. Thus even if the very ingenious drafting board now in the Wright Museum at Carillon Park was available at the time there is no indication that it was used to produce what could properly be called drawings of the first engine. [Footnote 5: Charles E. Taylor (Charley Taylor to the many who knew him) was in effect the superintendent of and also the only employee to work in the original small machine shop. A most versatile and efficient mechanic and machine operator, he made many parts for all of the early engines, and in the manner of the experimental machinist, worked mainly from sketches. He also had charge of the bicycle shop and its business in the absence of the Wrights.] There are in existence, however, two complete sets of drawings, both of which purport to represent the 1903 flight engine. One set was made in England for the Science Museum in the two years 1928 and 1939. The 1928 drawings were made on receipt of the engine, which was not disassembled, but in 1939 the engine was removed from the airplane, disassembled, the original 1928 drawings were corrected and added to, and the whole was made into one very complete and usable set. The other set was prepared in Dayton, Ohio, for Educational and Musical Arts, Inc.,[6] and was donated to the Smithsonian Institution. This latter set was started under the direction of Orville Wright, who died shortly after the work had been commenced. [Footnote 6: This is a charitable agency set up by the late Colonel and Mrs. E. A. Deeds primarily for the purpose of building and supporting the Deeds Carillon and the Carillon Park Museum in Dayton, Ohio.] The two sets of drawings, that is, the one of the Science Museum and that made in Dayton for the Smithsonian Institution, cannot be reconciled in the matter of details. Hardly any single dimension is exactly the same and essentially every part differs in some respect. Many of the forms of construction differ and even the firing order of the two engines is not the same, so that in effect the drawings show two different engines. [Illustration: Figure 1.--First flight engine, 1903, valve side. (Photo courtesy Science Museum, London.)] The primary trouble is, of course, that the exact engine which flew in 1903 is no longer in existence, and since no original drawings of it exist, there is considerable doubt about its details. The engine had its crankcase broken in an accident to the airframe (this was caused by a strong wind gust immediately following the last of the first series of flights at Kitty Hawk), and when it was brought back to Dayton it was for some inexplicable reason completely laid aside, even though it presumably contained many usable parts. When the engine was disassembled to obtain measurements for constructing the 1904 engines, again apparently no drawings were made. In February 1906 Orville Wright wrote that all the parts of the engine were still in existence except the crankcase; but shortly after this the crankshaft and flywheel were loaned for exhibition purposes and were never recovered. In 1926 the engine was reassembled for an exhibition and in 1928 it was again reassembled for shipment to England. The only parts of this particular engine whose complete history is definitely known are the crankshaft and flywheel, which were taken from the 1904-1905 flight engine. This latter engine, now in the restored 1905 airplane in the Carillon Park Museum in Dayton, does not contain a crankshaft, and in its place incorporates a length of round bar stock. [Illustration: Figure 2.--First flight engine, 1903, underside and flywheel end. (Photo courtesy Science Museum, London.)] In late 1947 work on the Educational and Musical Arts drawings was initiated under the direction of Louis P. Christman and carried through to completion by him. Christman has stated that Orville Wright was critical of the Science Museum drawings but just what he thought incorrect is not known. Whatever his reasons, he did encourage Christman to undertake the major task of duplication. Christman worked directly with Orville Wright for a period of six weeks and had access to all the records and parts the Wrights had preserved. The resultant drawings are also very complete and, regardless of the differences between these two primary sets, both give a sufficiently accurate picture of the first engine for all purposes except that of exact reproduction in every detail. There exists a still unsolved puzzle in connection with what seems to be yet another set of drawings of the first engine. In December 1943, in writing to the Science Museum telling of his decision to have the airplane and engine brought back to the United States, Orville Wright stated, "I have complete and accurate drawings of the engine. I shall be glad to furnish them if you decide to make a replica."[7] No trace of these particular drawings can be found in any of the museums, institutions, or other repositories that normally should have acquired them and the executors of Orville Wright's estate have no record or knowledge of them. The date of his letter is four years before the Dayton drawings were commenced; and when Christman was working on these with Orville Wright they had copies of the Science Museum drawings, with complete knowledge of their origin, yet Christman has no knowledge of the drawings referred to in Orville's letter to the Museum. Finally, the evidence is quite conclusive that there were no reproducible or permanent drawings made at the time the first engine was constructed, and, of course, the reconstructed engine itself was sent to England in 1928 and not returned to this country until 1948.[8] [Footnote 7: The Science Museum expressed a desire to have these but never received them. There is a reference to them in a letter to the Museum from the executors of his estate dated 20 February 1948, but is seems rather obvious from the text that by this time the drawings mentioned by Orville Wright in his 1943 letter had become confused with those being prepared by Christman for the Smithsonian Institution. The Science Museum did have constructed from its own drawings a very fine replica which is completely operable at this time.] [Footnote 8: There is a third set of drawings prepared by the Ford Motor Company also marked as being of the 1903 engine and these are rather well distributed in various museums and institutions. What this set is based on has been impossible to determine but it is indicated from the existence of actual engines and parts and the probable date of their preparation (no date is given on the drawings themselves) that they were copied from drawings previously made, and therefore add nothing to them. The Orville Wright-Henry Ford friendship originated rather late, considering Ford's avid interest in history and mechanical things. This tardiness could possibly have been the result of Wright coolness--a coolness caused by a report, at the time the validity of the Wright patents was being so strongly contested, that Ford had advised some of those opposing the Wrights to persevere and to obtain the services of his patent counsel who had been successful in overturning the Selden automobile patent. If this barrier ever existed it was surmounted, and Ford spent much effort and went to considerable expense to collect the Wright home and machine shop for his Dearborn museum. The shop equipment apparently had been widely scattered and its retrieval was a major task. It is most likely that the drawings resulted from someone's effort to follow out an order to produce a set of Ford drawings of the original engine. A small scale model of the 1903 flight engine, constructed under the supervision of Charles Taylor, is contained in the Dearborn Museum.] The Engine of the First Flight, 1903 In commencing the design of the first engine, the first important decision arrived at was that of the number and size of the cylinders to be employed and the form in which they would be combined, although it is unlikely that this presented any serious problem. In a similar situation Manly, when he was working on the engine for the Langley Aerodrome,[9] was somewhat perturbed because he did not have access to the most advanced technical knowledge, since the automobile people who were at that time the leaders in the development of the internal combustion engine, tended for competitive reasons to be rather secretive about their latest advancements and designs. But although the standard textbooks may not have been very helpful to him, there were available such volumes as W. Worby Beaumont's _Motor Vehicles and Motors_ which contained in considerable detail descriptions and illustrations of the best of the current automobile engines. The situations of Manly and the Wrights differed, however, in that whereas the Wrights' objective was certainly a technical performance considerably above the existing average, Manly's goal was that of something so far beyond this average as to have been considered by many impossible. Importantly, the Wrights had their own experience with their shop engine and a good basic general knowledge of the size of engine that would be necessary to meet their requirements. [Footnote 9: Charles L. Manly was engaged in the development of the engine for the Langley Aerodrome. See also footnote to Table on page 62.] Engine roughness was of primary concern to them. In the 1902 description of the engine they sent to various manufacturers, they had stated: "... and the engine would be free from vibration." Even though their requirement for a smooth engine was much more urgent than merely to avoid the effect of roughness on the airplane frame, they were faced, before they made their first powered flight, with the basic problem with which the airplane has had to contend for over three-quarters of its present life span: that is, it was necessary to utilize an explosion engine in a structure which, because of weight limitations, had to be made the lightest and hence frailest that could possibly be devised and yet serve its primary purpose. However great the difficulty may have appeared, in the long view, the fault was certainly a relatively minor one in the overall development of the internal combustion engine--that wonderful invention without which their life work would probably never have been so completely successful while they lived, and which, even aside from its partnership with the airplane, has so profoundly affected the nature of the world in which we live. It seems quite obvious that to the Wrights vibration, or roughness, was predominantly if not entirely caused by the explosion forces, and they were either not completely aware of the effects of the other vibratory forces or they chose to neglect them. Although crankshaft counterweights had been in use as far back as the middle 1800s, the Wrights never incorporated them in any of their engines; and despite the inherent shaking force in the 4-inline arrangement, they continued to use it for many years. The choice of four cylinders was obviously made in order to get, for smoothness, what in that day was "a lot of small cylinders"; and this was sound judgment. Furthermore, although the majority of automobiles at that time had engines with fewer than four cylinders, for those that did the inline form was standard and well proven, and, in fact, Daimler was then operating engines of this general design at powers several times the minimum the Wrights had determined necessary for their purpose. What fixed the exact cylinder size, that is, the "square" 4×4-in. form, is not recorded, nor is it obvious by supposition. Baker says it was for high displacement and low weight, but these qualities are also greatly affected by many other factors. The total displacement of just over 200 cu in. was on the generous side, given the horsepower they had determined was necessary, but here again the Wrights were undoubtedly making the conservative allowances afterwards proven habitual, to be justified later by greatly increased power requirements and corresponding outputs. The Mean Effective Pressure (MEP), based on their indicated goal of 8 hp, would be a very modest 36 psi at the speed of 870 rpm at which they first tested the engine, and only 31 psi at the reasonably conservative speed of 1000 rpm. The 4×4-in. dimension would provide a cylinder large enough so that the engine was not penalized in the matter of weight and yet small enough to essentially guarantee its successful operation, as cylinders of considerably larger bore were being utilized in automobiles. That their original choice was an excellent one is rather well supported by the fact that in all the different models and sizes of engines they eventually designed and built, they never found it necessary to go to cylinders very much larger than this. [Illustration: _Figure 3._--First flight engine, 1903, installed in the Kitty Hawk airplane, as exhibited in the Science Museum. (Photo courtesy the Science Museum, London.)] A second basic determination which was made either concurrently or even possibly in advance of that of the general form and size was in the matter of the type of cylinder cooling to adopt. Based on current practice that had proven practical, there were three possibilities, all of which were in use in automobiles: air, water, or a combination of the two. It is an interesting commentary that Fernand Forest's[10] proposed 32-cylinder aircraft engine of 1888 was to be air-cooled, that Santos-Dumont utilized an air-cooled Clement engine in his dirigible flights of 1903, and that the Wrights had chosen air cooling for their shop engine. With the promise of simplicity and elimination of the radiator, water and piping, it would seem, offhand, that this would be the Wrights' choice for their airplane; but they were probably governed by the fact that not only was the water-cooled type predominant in automobile practice, but that the units giving the best and highest performance in general service were all water cooled. In their subsequent practice they never departed from this original decision, although Wilbur Wright's notebook of 1904-1907 contains an undated weight estimate by detailed parts for an 8-cylinder air-cooled engine. Unfortunately, the proposed power output is not recorded, so their conception of the relative weight of the air-cooled form is not disclosed. [Footnote 10: Fernand Forest, _Les Bateaux Automobiles_, 1906.] One of the most important decisions relating to the powerplant--one which was probably made long before they became committed to the design itself--was a determination of the method of transmission of power to the propeller, or propellers. A lingering impression exists that the utilization of a chain drive for this purpose was a natural inheritance from their bicycle background. No doubt this experience greatly simplified the task of adaptation but a merely cursory examination shows that even if they had never had any connection with bicycles, the chain drive was a logical solution, considering every important element of the problem. The vast majority of automobiles of the time were chain driven, and chains and sprockets capable of handling a wide range of power were completely developed and available. Further, at that time they had no accurate knowledge of desirable or limiting propeller and engine speeds. The chain drive offered a very simple and inexpensive method of providing for a completely flexible range of speed ratios. The other two possibilities were both undesirable: the first, a simple direct-driven single propeller connected to the crankshaft, provided essentially no flexibility whatsoever in experimentally varying engine or propeller speed ratios, it added an out-of-balance engine torque force to the problem of airplane control, and, finally, it dictated that the pilot would be in the propeller slipstream or the airflow to it; the second, drive shafts and gearing for dual propellers, would have been very heavy and expensive, and most probably would have required a long-time development, with every experimental change in speed ratios requiring a complete change in gears. Again, their original choice was so correct that it lasted them through essentially all their active flying years. The very substantial advantages of the chain drive were not, however, obtained at no cost. Torque variations in the engine would tend to cause a whipping action in the chain, so that it was vulnerable to rough running caused by misfiring cylinders and, with the right timing and magnitude of normal regular variations, the action could result in destructive forces in the transmission system. This was the basic reason for the Wrights' great fear of "engine vibration," which confined them to the use of small cylinders and made a fairly heavy flywheel necessary on all their engines. When they were requested to install an Austro-Daimler engine in one of their airplanes, they designed a flexible coupling which was interposed between the engine and the propeller drive and this was considered so successful that it was applied to the flywheel of some engines of their last model, the 6-70, "which had been giving trouble in this regard."[11] [Footnote 11: Grover Loening, letter of 10 April 1963, to the Smithsonian Institution.] Although flat, angled, and vertical engines had all been operated successfully, the best and most modern automotive engines of the time were vertical, so their choice of a horizontal position was probably dictated either by considerations of drag or their desire to provide a sizable mounting base for the engine, or both. There is no record of their ever having investigated the matter of the drag of the engine, either alone or in combination with the wing. The merit of a vertical versus a horizontal position of the engine was not analogous to that of the pilot, which they had studied, and where the prone position undoubtedly reduced the resistance. Having decided on the general makeup of their engine, the next major decision was that of just what form the principal parts should take, the most important of these being the cylinders and crankcase. Even at this fairly early date in the history of the internal combustion engine various successful arrangements and combinations were in existence. Individual cylinder construction was by far the most used, quite probably due to its case of manufacture and adaptability to change. Since 4-cylinder engines were just coming into general use (a few production engines of this type had been utilized as early as 1898), there were few examples of en-bloc or one-piece construction. The original German Daimler Company undoubtedly was at this time the leader in the development of high-output internal-combustion engines, and in 1902, as an example of what was possible, had placed in service one that possibly approximated 40 hp, which was an MEP of 70 psi. (Almost without exception, quoted power figures of this period were not demonstrated quantities but were based on a formula, of which the only two factors were displacement and rpm.) The cylinders of this Daimler engine were cast iron, the cylinder barrel, head, and water jacket being cast in one piece. The upper part of the barrel and the cylinder head were jacketed, but, surprisingly, the bottom 60 percent of the barrel had no cooling. The cylinders were cast in pairs and bolted to a two-piece aluminum case split at the line of the crankshaft. Ignition was make-and-break and the inlet valves were mechanically actuated. Displacement was 413 cu in. and the rpm was 1050. Although a few examples of integral crankcase and water jacket combinations were in use, the Wrights were being somewhat radical when they decided to incorporate all four cylinders in the one-piece construction, particularly since they also proposed to include the entire crankcase and not just one part of it. It was undoubtedly the most important decision that they were required to make on all the various construction details, and probably the one given the most study and investigation. Many factors were involved, but fundamentally everything went back to their three basic requirements: suitability, time, and cost. There was no obvious reason why the construction would not work, and it eliminated a very large number of individual parts and the required time for procuring, machining, and joining them. Probably one very strong argument was the advanced state of the casting art, one of the oldest of the mechanical arts in existence and one the Wrights used in many places, even though other processes were available. What no doubt weighed heavily was that Dayton had some first-class foundries. The casting, though intricate and not machinable in their own shop, could be easily handled in one that was well outfitted. The pattern was fairly complex but apparently not enough to delay the project or cause excessive cost. [Illustration: _Figure 4._--First flight engine, 1903, left side and rear views, with dimensions. (Drawing courtesy Howell Cheney Technical School.) LEFT SIDE VIEW.] [Illustration: REAR VIEW] The selection of aluminum for the material was an integral part of the basic design decision. Despite the excellence and accuracy of the castings that could be obtained, there was nevertheless a minimum dimension beyond which wall thickness could not be reduced; and the use of either one of the two other proven materials, cast iron or bronze, would have made the body, as they called it, prohibitively heavy. The use of aluminum was not entirely novel at this time, as it had been utilized in many automobile engine parts, particularly crankcases; but its incorporation in this rather uncommon combination represented a bold step. There was no choice in the matter of the alloy to be used, the only proven one available was an 8 percent copper 92 percent aluminum combination. By means of the proper webs, brackets and bosses, the crankcase would also carry the crankshaft, the rocker arms and bearings, and the intake manifold. The open section of the case at the top was covered with a screw-fastened thin sheet of cold-rolled steel. The main bearing bosses were split at a 45° angle for ease of assembly. The engine support and fastening were provided by four feet, or lugs, cast integral on the bottom corners of the case, and by accompanying bolts (Figure 2). Although the crankcase continued to be pretty much the "body" of the internal combustion aircraft engine throughout its life, the Wrights managed to incorporate in this original part a major portion of the overall engine, and certainly far more than had ever previously been included. The design of the cylinder barrel presented fairly simple problems involving not much more than those of keeping the sections as thin as possible and devising means of fastening it and of keeping the water jacket tight. They saved considerable weight by making the barrel quite short, so that in operation a large part of the piston extended below the bottom of it; but this could be accepted, as there were no rings below the piston pin (Figure 6). The barrel material, a good grade of cast iron, was an almost automatic choice. In connection with these seemingly predetermined decisions, however, it should be remembered that their goal was an engine which would work without long-time development, and that, with no previous experience in lightweight construction to guide them they were nevertheless compelled to meet a weight limit, so that the thickness of every wall and flange and the length of every thread was important. With the separate cylinder barrel they were now almost committed to a three-piece cylinder. It would have been possible to combine the barrel and head in a one-piece casting and then devise a method of attachment, but this would have been more complex and certainly heavier. For housing the valves, what was in effect a separate cylindrical, or tubular, box was decided upon. This would lie across the top of the cylinder proper at right angles to the cylinder axis, and the two valves would be carried in the two ends of this box. The cylinder barrel would be brought in at its head end to form a portion of the cylinder head and then extended along its axis in the form of a fairly large boss, a mating boss being provided on one side of the valve box. The cylinder barrel would then be threaded into the valve box and the whole tightened or fastened to the crankcase by means of two sets of threads, one at each end of the barrel proper. This meant that three joints had to be made tight with only two sets of threads. This was accomplished by accurate machining and possibly even hand fitting in combination with a rather thick gasket at the head end, one flat of which bore against two different surfaces. This can be seen in Figure 6, where the circular flange on the valve box contacts both the crankcase and the cylinder barrel. Altogether it was a simple, light, and ingenious solution to a rather complex problem. At this point the question arises: Why was the engine layout such that the exhaust took place close to the operator's ears? It would have been possible, starting with the original design, to turn the engine around so that the exhaust was on the other side. This would have little effect on the location of the center of gravity, and the two main drive chains would then have been of more equal length. However, of the many factors involved, probably one of the principal considerations in arriving at their final decision was the location of the spark-advance control, which was in effect the only control they had of engine output, except for complete shutoff. In their design this was immediately adjacent to the operator; with a turned-around engine, an extension control mechanism of some sort would have been required. The noise of the exhaust apparently became of some concern to them, as Orville's diary in early 1904 contains an entry with a sketch labeled "Design for Muffler for Engine," but there is no further comment. The problem of keeping joints tight, and for that matter the entire construction itself, were both greatly simplified by their decision to water-jacket only a part of the cylinder head proper, and the valve box not at all. This was undoubtedly the correct decision for their immediate purpose, as again they were effecting savings in time, cost, complexity, and weight. There is nothing in the record, however, to show why they continued this practice long after they had advanced to much greater power outputs and longer flight times. Their own statements show that they were well aware of the effect of the very hot cylinder head on power output and they must also have realized its influence on exhaust-valve temperature. The cylinder assembly was made somewhat more complicated by their desire to oil the piston and cylinder by means of holes near the crankshaft end in what was, with the engine in the horizontal position, the upper side of the cylinder barrel. This complication was no doubt taken care of by not drilling the holes until a tight assembly had been made by screwing the barrel into place, and by marking the desired location on the barrel. Since this position was determined by a metal-to-metal jam fit of the crankcase and cylinder barrel flange, the barrel would reassemble with the holes in very nearly the same relative position after disassembly. With the valve box, or housing, cylindrical, the task of locking and fastening the intake and exhaust valve guides and seats in place was easy. The guide was made integral with and in the center of one end of a circular cage, the other end of which contained the valve seat (see Figure 5). Four sections were cut out of the circular wall of the cage so that in effect the seat and guide were joined by four narrow legs, the spaces between which provided passages for the flow of the cylinder gases. These cages were then dropped into the ends of the valve boxes until they came up against machined shoulders and were held in place by internal ring nuts screwed into the valve box. The intake manifold or passage was placed over the intake valves so that the intake charge flowed directly into and through the valve cage around the open valve and into the cylinder. The exhaust gas, after flowing through the passages in the valve cage, was discharged directly to the atmosphere through a series of holes machined in one side of the valve box. [Illustration: _Figure 5._--First flight engine, 1903, assembly. (Phantom cutaway by J. H. Clark, with key, courtesy _Aeroplane_.) KEY 1 and 2. Bearing caps in one piece with plate 3. 3. Plated screwed over hole 4 in crankcase end. 4. Key-shaped hole as hole 5 in intermediate ribs. 6. Inter-bearings cap (white-metal lined) and screwed to inter-rib halves 7. 8. Splash-drip feed to bearings. 9. Return to pump from each compartment of crankcase base ("sump") via gallery 10 and pipe to pump 11 underneath jacket. 12. Oil feed from pump via rubber tube 13. 13. Drip feeds to cylinders and pistons. 14. Gear drive to pump. 15. Big-end nuts, lock-strip, and shims. 16. Gudgeon-pin lock. 17. Piston-ring retainer pegs. 18. Cylinder liner screwing into jacket. 19. Open-ended "can" admits air. 20. Fuel supply. 21. (Hot) side of water jacket makes surface carburetter. 22. Sparking plug (comprising positive electrode 23 and spark-producing make-and-break 24). 25. Lever attached to lever 26 via bearing 27 screwed into chamber neck 28. 26. Levers with mainspring 29 and inter-spring 30, and rocked by "cam" 31. 31. Cam with another alongside (for adjacent cylinder). 32. Positive busbar feed to all four cylinders. 33. Assembly retaining-rings. 34. Sealing disc. 35. Exhaust outlet ports. 36. Camshaft right along on underside of jacket and also driving oil pump 11 via 14. 37. Spring-loaded sliding pinion drives make-and-break shaft 38 through peg in inclined slot 39. 40. Cam to push pinion 37 along and so alter its angular relation with shaft 38 (to vary timing). 41. Exhaust-valve cams bear on rollers 42 mounted in end of rocker-arms 43. 44. Generator floating coils. 45. Friction-drive off flywheel. 46. Sight-feed lubricator (on stationary sleeve). 47. Hardwood chain tensioner.] The intake and exhaust valves were identical and of two-piece construction, with the stems screwed tightly into and through the heads and the protruding ends then peened over. This construction was not novel, having had much usage behind it, and it continued for a long time in both automobile and aircraft practice. One-piece cast and forged valves were available but here again it was a choice of the quick, cheap, and proven answer. The entire valve system, including guides and seats, was of cast iron, a favorite material of the Wrights, except for the valve stems, which were, at different times, of various carbon steels. Ordinary cold-rolled apparently was used in those of the original engine, but in later engines this was changed to a high-carbon steel. The piston design presented no difficulty. In some measure this was due to the remarkable similarity that seems to have existed among all the different engines of the time in the construction of this particular part, for, although there were some major variations, it was, in fact, almost as if some standard had been adopted. Pistons all were of cast iron and comparatively quite long (it was a number of years before they evolved into the short ones of modern practice); they were almost invariably equipped with three wide piston rings between the piston pin and the head; and, although there were in existence a few pistons with four rings, no oil wiper or other ring seems to have been placed below the piston pin. The Wrights' piston was typical of the time, with the rings pinned in the grooves to prevent turning and the piston pin locked in the piston with a setscrew. In designing this first engine they were, however, apparently somewhat unsure about this latter feature, as they provided the rod with a split little end and a clamping bolt (see Figure 6), so that the pin could be held in the rod if desired; but no examples of this use have been encountered. The Wrights' selection of an "automatic" or suction-operated inlet valve was entirely logical. Mechanically operated inlet valves were in use and their history went back many years, but the great majority of the engines of that time still had the automatic type, and with this construction one complete set of valve-operating mechanisms was eliminated. They were well aware of the loss of volumetric efficiency inherent in this valve, and apparently went to some pains to obtain from it the best performance possible. Speaking of the first engine, Orville Wright wrote, "Since putting in heavier springs to actuate the valves on our engine we have increased its power to nearly 16 hp and at the same time reduced the amount of gasoline consumed per hour to about one-half of what it was."[12] [Footnote 12: Assuming a rich mixture, consumption of all the air, and an airbrake thermal efficiency of 24.50% for the original engine, the approximate volumetric efficiency of the cylinder is calculated to have been just under 40%.] Why they continued with this form on their later engines is a question a little more difficult to answer, as they were then seeking more and more power and were building larger engines. The advantages of simplicity and a reduced number of parts still existed, but there also was a sizable power increase to be had which possibly would have more than balanced off the increased cost and weight. They did not utilize mechanical operation until after a major redesign of their last engine model. Very possibly the answer lies in the phenomenon of fuel detonation. This was only beginning to be understood in the late 1920s, and it is quite evident from their writings that they had little knowledge of what made a good fuel in this respect. It is fairly certain, however, that they did know of the existence of cylinder "knock," or detonation, and particularly that the compression ratio had a major effect on it. The ratios they utilized on their different engines varied considerably, ranging from what, for that time, was medium to what was relatively high. The original flight engine had a compression ratio of 4.4:1. The last of their service engines had a compression ratio about twenty percent under that of the previous series--a clear indication that they considered that they had previously gone too high. Quite possibly they concluded that increasing the amount of the cylinder charge seemed to bring on detonation, and that the complication of the mechanical inlet valve was therefore not warranted. [Illustration: _Figure 6._--First flight engine, 1903, cross section. (Drawing courtesy Science Museum, London.)] The camshaft for the exhaust valves (101, Figure 6), was chain driven from the crankshaft and was carried along the bottom of the crankcase in three babbit-lined bearings in bearing boxes or lugs cast integral with the case. Both the driving chain and the sprockets were standard bicycle parts, and a number of bicycle thread standards and other items of bicycle practice were incorporated in several places in the engine, easing their construction task. The shaft itself, of mild carbon steel, was hollow and on each side of an end bearing sweated-on washers provided shoulders to locate it longitudinally. Its location adjacent to the valves, with the cam operating directly on the rocker arm, eliminated push rods and attendant parts, a major economy. The cams were machined as separate parts and then sweated onto the shaft. Their shape shows the principal concern in the design to have been obtaining maximum valve capacity--that is, a quite rapid opening with a long dwell. This apparent desire to get rid of the exhaust gas quickly is manifested again in the alacrity with which they adopted a piston-controlled exhaust port immediately they had really mastered flight and were contemplating more powerful and more durable engines. This maximum-capacity theory of valve operation, with its neglect of acceleration forces and seating velocities, may well have been at least partially if not largely the cause of their exhaust-valve troubles and the seemingly disproportionate amount of development they devoted to this part, as reported by Chenoweth, although it is also true that the exhaust valve continued to present a problem in the aircraft piston engine for a great many years after, even with the most scientific of cam designs. The rocker arm (102, Figure 6) is probably the best example of a small part which met all of their many specific requirements with an extreme of simplicity. It consisted of two identical side pieces, or walls, of sheet steel shaped to the desired side contour of the assembly, in which were drilled three holes, one in each end, to carry the roller axles, and the third in the approximate middle for the rocker axle shaft proper. This consisted of a piece of solid rod positioned by cotter pins in each end outside the side walls (see Figure 5). The assembly was made by riveting over the ends of the roller axles so that the walls were held tightly against the shoulders on the axles, thus providing the correct clearance for the rollers. The construction was so light and serviceable that it was essentially carried over to the last engine the Wrights ever built. The basic intake manifold (see Figure 5) consisted of a very low flat box of sheet steel which ran across the tops of the valve boxes and was directly connected to the top of each of them so that the cages, and thus the valves, were open to the interior of the manifold. Through an opening in the side toward the engine the manifold was connected to a flat induction chamber (21, Figure 5) which served to vaporize the fuel and mix it with the incoming air. This chamber was formed by screw-fastening a piece of sheet steel to vertical ribs cast integral with the crankcase, the crankcase wall itself thus forming the bottom of the chamber. A beaded sheet-steel cylinder resembling a can (73, Figure 6) but open at both ends was fastened upright to the top of this chamber. In the absence of anything else, this can could be called the carburetor, as a fuel supply line entered the cylinder near the top and discharged the fuel into the incoming air stream, both the fuel and air then going directly into the mixing chamber. The can was attached near one corner of the chamber, and vertical baffles, also cast integral with the case, were so located that the incoming mixture was forced to circulate over the entire area of exposed crankcase inside the chamber before it reached the outlet to the manifold proper, the hot surface vaporizing that part of the fuel still liquid. [Illustration: _Figure 7._--First flight engine, 1903: cylinder, valve box, and gear mechanism; below, miscellaneous parts. (Photos courtesy Science Museum, London, and Louis P. Christman.)] Fuel was gravity fed to the can through copper and rubber tubing from a tank fastened to a strut, several feet above the engine. Of the two valves placed in the fuel line, one was a simple on-off shutoff cock and the other a type whose opening could be regulated. The latter was adjusted to supply the correct amount of fuel under the desired flight operating condition; the shutoff cock was used for starting and stopping. The rate of fuel supply to the engine would decrease as the level in the fuel tank dropped, but as the head being utilized was a matter of several feet and the height of the supply tank a matter of inches, the fuel-air ratio was still maintained well within the range that would ignite and burn properly in the contemplated one-power condition of their flight operation. This arrangement is one of the best of the many illustrations of how by the use of foresight and ingenuity the Wrights met the challenge of a complex requirement with a simple device, for while carburetors were not in the perfected stage later attained, quite good ones that would both control power output and supply a fairly constant fuel-air mixture over a range of operating conditions were available, but they were complex, heavy, and expensive. The arrangement, moreover, secured at no cost a good vaporizer, or modern "hot spot." In their subsequent engines they took the control of the fuel metering away from the regulating valve and gravity tank combination and substituted an engine-driven fuel pump which provided a fuel supply bearing a fairly close relationship to engine speed. The reasons behind selection of the type of ignition used, and the considerations entering into the decision, are open to speculation, as are those concerning many other elements that eventually made up the engine. Both the high-tension spark plug and low-tension make-and-break systems had been in wide use for many years, with the latter constituting the majority in 1902. Both were serviceable and therefore acceptable, and both required a "magneto". The art of the spark plug was in a sense esoteric (to a certain extent it so remains to this day), but the spark-plug system did involve a much simpler combination of parts: in addition to the plug and magneto there would be needed only a timer, or distributor, together with coils and points, or some substitute arrangement. The make-and-break system, on the other hand, required for each cylinder what was physically the equivalent of a spark plug, that is, a moving arm and contact point inside the cylinder, a spring-loaded snap mechanism to break the contact outside the cylinder, and a camshaft and cams to actuate the breaker mechanism at the proper time. Furthermore, as the Wrights applied it, the system required dry cells and a coil for starting, although these did not accompany the engine in flight. And finally there was the problem of keeping tight the joint where the oscillating shaft required to operate the moving point in the spark plug entered the cylinder. This is one of the few occasions, if not the only one, when the Wrights chose the more complex solution in connection with a major part--in this particular case, one with far more bits and pieces. However, it did carry with it some quite major advantages. The common spark plug, always subject to fouling or failure to function because of a decreased gap, was not very reliable over a lengthy period, and was undoubtedly much more so in those days when control of the amount of oil inside the cylinder was not at all exact. Make-and-break points, on the other hand, were unaffected by excess oil in the cylinder. Because of this resistance to fouling, the system was particularly suitable for use with the compression-release method of power control which they later utilized, although they probably could not have been looking that far ahead at the time they chose it. High-tension current has always, and rightfully so, been thought of as a troublemaker in service; in Beaumont's 1900 edition of _Motor Vehicles and Motors_, which seems to have been technically the best volume of its time, the editor predicted that low-tension make-and-break ignition would ultimately supersede all other methods. And finally, the large number of small parts required for the make-and-break system could all be made in the Wright Brothers' shop or easily procured, and in the end this was probably the factor, plus reliability, that determined the decision which, all things considered, was the correct one. There was nothing exceptional about the exact form the Wrights devised. It displayed the usual refined simplicity (the cams were made of a single small piece of strip steel bent to shape and clamped to the ignition camshaft with a simple self-locking screw), and lightness. The ignition camshaft (38, Figure 5), a piece of small-diameter bar stock, was located on the same side as the exhaust valve camshaft, approximately midway between it and the valve boxes, and was operated by the exhaust camshaft through spur gearing. That the Wrights were thinking of something beyond mere hops or short flights is shown by the fact that the ignition points were platinum-faced, whereas even soft iron would have been satisfactory for the duration of all their flying for many years. The control of the spark timing was effected by advancing or retarding the ignition camshaft in relation to the exhaust valve camshaft. The spur gear (37, Figure 5) driving the ignition camshaft had its hub on one side extended out to provide what was in effect a sleeve around the camshaft integral with the gear. The gear and integral sleeve were slidable on the shaft and the sleeve at one place (39, Figure 5) was completely slotted through to the shaft at an angle of 45° to the longitudinal axis of the shaft. The shaft was driven by a pin tightly fitted in it and extending into the slot. The fore-and-aft position of the sleeve on the shaft was determined by a lever-operated cam (40, Figure 5) on one side and a spring on the other. The movement of the sleeve along the shaft would cause the shaft to rotate in relation to it because of the angle of the slot, thus providing the desired variation in timing of the spark. The "magneto" was a purchased item driven by means of a friction wheel contacting the flywheel, and several different makes were used later, but the original is indicated to have been a Miller-Knoblock (see Figure 5). The connecting rod is another example of how, seemingly without trouble, they were able to meet the basic requirements they had set for themselves. It consisted of a piece of seamless steel tubing with each end fastened into a phosphor-bronze casting, these castings comprising the big and little ends, drilled through to make the bearings (See Figures 5 and 6). It was strong, stiff and light.[13] Forged rods were in rather wide use at the time and at least one existing engine even had a forged I-beam section design that was tapered down from big to little end. The Wrights' rod was obtained in little more time than it took to make the simple patterns for the two ends. The weight was easily controlled, no bearing liners were necessary, and a very minimum of machining was required. Concerning the big-end material, there exists a contradiction in the records: Baker, whose data are generally most accurate, states that these were babbited, but this must be in error, as the existing engine has straight bronze castings without babbiting, and there is no record, or drawing, or other indication of the bearings having been otherwise. [Footnote 13: A rather thorough stress analysis of the rod shows it to compare very favorably with modern practice. In the absence of an indicator card for the 1903 engine, if a maximum gas pressure of five times the MEP is assumed, the yield-tension factor of safety is measurably higher than that of two designs of piston engines still in wide service, and the column factor of safety only slightly less. The shear stresses in the brazed and threaded joints are so low as to be negligible.] Different methods of assembling the rod were used. At one time the tube ends were screwed into the bronze castings and pinned, and at another the ends were pinned and soldered. There is an indication that at one time soldering and threads were used in combination. One of the many conflicts between the two primary sets of drawings exists at this point. The Smithsonian drawings show the use at each end of adapters between the rod and end castings, the adapters being first screwed into the castings and pinned and then brazed to the inside of the tube. The Science Museum drawings show the tube section threaded and screwed into the castings. The direct screw assembly method called for accurate machining and hand fitting in order to make the ends of the tubing jam against the bottom of the threaded holes in the castings, and at the same time have the end bearings properly lined up. The weakness of the basic design patently lies in the joints. It is an attempt to utilize what was probably in the beginning a combination five-piece assembly and later three, in a very highly stressed part where the load was reversing. It gave them considerable trouble from time to time, particularly in the 4-cylinder vertical engines, and was abandoned for a forged I-beam section type in their last engine model; but it was nevertheless the ideal solution for their first engine. The crankshaft was made from a solid block of relatively high carbon steel which, aside from its bulk and the major amount of machining required, presented no special problems. It was heat-treated to a machinable hardness before being worked on, but was not further tempered. The design was an orthodox straight pin and cheek combination and, as previously noted, there were no counterweights to complicate the machining or assembly. A sizable bearing was provided on each side of each crank of the shaft, which helped reduce the stiffness requirement. Their only serious design consideration was to maintain the desired strength and still keep within weight limitations. A fundamental that every professional designer knows is that it is with this particular sort of part that weight gets out of control; even an additional 1/16 in., if added in a few places, can balloon the weight. With their usual foresight and planning, the Wrights carefully checked and recorded the weight of each part as it was finished, but even this does not quite explain how these two individuals, inexperienced in multicylinder engines--much less in extra-light construction--could, in two months, bring through an engine which was both operable and somewhat lighter than their specification. In one matter it would seem that they were quite fortunate. The records are not complete, but with one exception there is no indication of any chronic or even occasional crankshaft failure. This would seem to show that it apparently never happened that any of their designs came out such that the frequency of a vibrating force of any magnitude occurred at the natural frequency of the shaft. Much later, when this type of vibration became understood, it was found virtually impossible, with power outputs of any magnitude, to design an undampened shaft, within the space and weight limitations existing in an ordinary engine, strong enough to withstand the stress generated when the frequency of the imposed vibration approximated the natural frequency of the shaft. The vibratory forces were mostly relatively small in their engines, so that forced vibration probably was not encountered, and the operating speed range of the engines was so limited that the natural frequency always fell outside this range. The flywheel was about the least complex of any of their engine parts and required little studied consideration, although they did have to balance its weight against the magnitude of the explosion forces which would reach the power transmission chains, with their complete lack of rigidity, a problem about which they were particularly concerned. The flywheel was made of cast iron and was both keyed to and shrunk on the shaft. Some doubt still exists about the exact method of lubricating the first engine. The unit presently in the airplane has a gear-type oil pump driven by the crankshaft through a worm gear and cross shaft, and the Appendix to the _Papers_ states that it was lubricated by a small pump; nevertheless Baker says, after careful research, that despite this evidence, it was not. Also, the drawings prepared by Christman (they were commenced under the supervision of Orville Wright) do not show the oil pump. In March 1905 Wilbur Wright wrote to Chanute, "However we have added oiling and feeding devices to the engine ..."; but this could possibly have referred to something other than an oil pump. But even if a pump was not included originally, its presence in the present engine is easily explained. Breakage of the crankcase casting caused the retirement of this engine, which was not rebuilt until much later, and the pattern for this part had no doubt long since been altered to incorporate a pump. It was therefore easier in rebuilding to include than to omit the pump, even though this required the addition of a cross shaft and worm gear combination. On later engines, when the pump was used, oil was carried to a small pipe, running along the inside of the case, which had four small drill holes so located as to throw the oil in a jet on the higher, thrust-loaded side of each cylinder. The rods had a sharp scupper on the outside of the big end so placed as also to throw the oil on this same thrust face. Some scuppers were drilled through to carry oil to the rod bearing and some were not. The first engine was finished and assembled in February 1903 and given its first operating test on 22 February. The Wrights were quite pleased with its operation, and particularly with its smoothness. Their father, Bishop Wright, was the recorder of their satisfaction over its initial performance, but what he noted was probably the afterglow of the ineffable feeling of deep satisfaction that is the reward that comes to every maker of a new engine when it first comes to life and then throbs. They obtained 13 hp originally: later figures went as high as almost 16, but as different engine speeds were utilized it is rather difficult to settle on any single power figure. The most realistic is probably that given in the _Papers_ as having been attained later, after an accurate check had been made of the power required to turn a set of propellers at a given rpm. This came out at approximately 12 hp, the design goal having been 8. Following exactly the procedure that exists to this day, the engine went through an extended development period, and it was the end of September 1903 before it was taken, with the airplane, to Kitty Hawk where the historic flights, which have had such a profound effect on the lives of all men, were made on 17 December 1903. The Engines With Which They Mastered The Art of Flying Two more engines of this first general design were built but they differed somewhat from each other as well as from the original. Together with a third 8-cylinder engine these were begun right after the first of the year in 1904, shortly after the Wrights' return from Kitty Hawk. In planning the 8-cylinder engine they were again only being forehanded, but considerably so, in providing more power for increased airplane performance beyond that which might possibly be obtained from the 4-cylinder units. Progress with the 4-cylinder engines was such that they fairly quickly concluded that the 8-cylinder size would not be necessary, and it was abandoned before completion. Exactly how far it was carried is not known. The record contains only a single note covering the final scrapping of the parts that had been completed; and apparently there were no drawings, so that even its intended appearance is not known with any exactness. It was probably a 90° V-type using their original basic cylinder construction. The changes carried through in the two 4-cylinder engines were not major. The water-cooled area of the cylinder barrel was increased by nearly ten percent but the head remained only partially cooled. In hindsight, this consistent avoidance of complete cylinder-head cooling presents the one most inexplicable of the more important design decisions they made, as it does not appear logical. In the original engine, where the factors of time and simplicity were of paramount importance, this made sense, but now they were contemplating considerably increased power requirements, knowing the effect of temperature on both the cylinder and the weight of cylinder charge, and knowing that valve failure was one of their most troublesome service problems. Nor does it seem that they could have been avoiding complete cylinder cooling through fear of the slightly increased complexity or the difficulty of keeping the water connections and joints tight, for they had faced a much more severe problem in their first engine, where their basic design required that three joints be kept tight with only two sets of threads, and had rather easily mastered it; so there must have been some much more major but not easily discernible factor which governed, for they still continued to use the poorly cooled head, even carrying it over to their next engine series. Very probably they did not know the effect on detonation of a high-temperature fuel-charge. One of the new engines was intended for use in their future experimental flying and has become known as _No. 2._ It had a bore of 4-1/8 in., incorporated an oil pump, and at some time shortly after its construction a fuel pump was added. The fuel pump was undoubtedly intended to provide a metering system responsive to engine speed and possibly also to eliminate the small inherent variation in flow of the original gravity system. This engine incorporated a cylinder compression release device not on the original. The exact reason or reasons for the application of the compression release have not been determined, although the record shows it to have been utilized for several different purposes under different operating conditions. Whatever the motivation for its initial application, it was apparently useful, as it was retained in one form or another in subsequent engine models up to the last 6-cylinder design. Essentially it was a manually controlled mechanism whereby all the exhaust valves could be held open as long as desired, thus preventing any normal charge intake or compression in the cylinder. Its one certain and common use was to facilitate starting, the open exhaust valves easing the task of turning the engine over by hand and making priming easy. In flight, its operation had the effect of completely shutting off the power. The propellers would then "windmill" and keep the engine revolving. One advantage stated for this method of operation was that when power was required and the control released, the engine would be at fairly high speed, so that full power was delivered immediately fuel reached the engine. It is also reported to have been used both in making normal landings and in emergencies, when an instant power shutdown was desired. Although it is not clear whether the fuel shutoff cock was intended to be manipulated when the compression release was used for any of these reasons, over the many years of its availability, undoubtedly at one time or another every conceivable combination of operating conditions of the various elements was tried. Because of the pumping power required with at least one valve open during every stroke, the windmilling speed of the engine was probably less than with any other method of completely stopping power output, but whether this difference was large enough to be noticeable, or was even considered, is doubtful. Since a simple ignition switch was all that was required to stop the power output, regardless of whether a fuel-control valve or a spark-advance control was used, it must be concluded that the primary function of the compression release was to facilitate starting, and any other useful result was something obtained at no cost. The compression release was later generally abandoned, and until the advent of the mechanical starter during the 1920s, starting an engine by "pulling the propeller through" could be a difficult task. With the Wrights' demonstrated belief that frugality was a first principle of design, it is hardly conceivable that they would have accepted for any other reason the complication of the compression-release mechanism if a simple ignition switch would have sufficed. The compression-release mechanism was kept relatively simple, considering what it was required to accomplish. A small non-revolving shaft was located directly under the rocker arm rollers that actuated the exhaust valves. Four slidable stops were placed on this shaft, each in the proper location, so that at one extreme of their travel they would be directly underneath the rocker roller and at the other extreme completely in the clear. They were positioned along the shaft by a spring forcing them in one direction against a shoulder integral with the shaft, and the shaft was slidable in its bearings, its position being determined by a manually controlled lever. When the lever was moved in one direction the spring pressure then imposed on the stops would cause each of them to move under the corresponding rocker roller as the exhaust valve opened, thus holding the exhaust valve in the open position. When the shaft was moved in the other direction the collar on the shaft would mechanically move the stop from underneath the roller, allowing the valve to return to normal operation. [Illustration: _Figure 8._--Development engine No. 3, 1904-1906, showing auxiliary exhaust port, separate one-piece water-jacket block. (Photo by author.)] If the 1903 engine is the most significant of all that the Wrights built and flew, then certainly the _No. 2_ unit was the most useful, for it was their sole power source during all their flying of 1904 and 1905 and, as they affirmed, it was during this period that they perfected the art, progressing from a short straightaway flight of 59 seconds to a flight controllable in all directions with the duration limited only by the fuel supply. It is to be greatly regretted that no complete log or record was kept of this engine. The Wrights again exhibited their engineering mastery of a novel basic situation when, starting out to make flight a practical thing, they provided engine _No. 3_ to be used for experimental purposes. In so doing they initiated a system which continues to be fundamental in the art of providing serviceable aircraft engines to this day--one that is expensive and time consuming, but for which no substitute has yet been found. Their two objectives were: improvement in performance and improvement in reliability, and the engine was operated rather continuously from early 1904 until well into 1906. Unfortunately, again, no complete record exists of the many changes made and the ideas tested, although occasional notes are scattered through the diaries and notebooks. In its present form--it is on exhibition at the Engineers Club in Dayton, Ohio--the _No. 3_ engine embodies one feature which became standard construction on all the Wright 4-cylinder models. This was the addition of a number of holes in a line part way around the circumference of the cylinder barrel so that they were uncovered by the piston at the end of its stroke toward the shaft, thus becoming exhaust ports (see Figure 9). This arrangement, although not entirely novel, was just beginning to come into use, and in its original form the ports exhausted into a separate chamber, which in turn was evacuated by means of a mechanically operated valve, so that two exhaust valves were needed per cylinder. Elimination of this chamber and the valve arrangement is typical of the Wrights' simplifying procedure, and it would seem that they were among the very first to use this form.[14] [Footnote 14: Rankin Kennedy, _Flying Machines--Practice and Design_, 1909.] The primary purpose of the scheme was to reduce, by this early release and consequent pressure and temperature drop, the temperature of the exhaust gases passing the exhaust valve, this valve being one of their main sources of mechanical trouble. It is probable that with the automatic intake valves being used there was also a slight effect in the direction of increasing the inlet charge, although with the small area of the ports and the short time of opening, the amount of this was certainly minor. With the original one-piece crankcase and cylinder jacket construction, the incorporation of this auxiliary porting was not easy, but this difficulty was overcome in the development engine by making different castings for the crankcase itself and for the cylinder jacket and separating them by several inches, so that room was provided between the two for the ports. This engine demonstrated the most power of any of the flat 4s, eventually reaching an output of approximately 25 hp, which was even somewhat more than that developed by the slightly larger 4-1/8-in.-bore flight engine, with which 21 hp was not exceeded. Indicative of the development that had taken place, the performance of the _No. 3_ engine was twice the utilized output of the original engine of the same size, an increase that was accomplished in a period of less than three years. The Wrights were only twice charged with having plagiarized others' work, a somewhat unusual record in view of their successes, and both times apparently entirely without foundation. A statement was published that the 1903 flight engine was a reworked Pope Toledo automobile unit, and it was repeated in an English lecture on the Wright brothers. This was adequately refuted by McFarland but additionally, it must be noted, there was no Pope Toledo company or car when the Wright engine was built. This company, an outgrowth of another which had previously manufactured one-and two-cylinder automobiles, was formed, or reformed, and a Pope license arrangement entered into during the year 1903. The other incident was connected with Whitehead's activities and designs. Whitehead was an early experimenter in flying, about the time of the Wrights, whose rather extraordinary claims of successful flight were published in the 1901-1903 period but received little attention until very much later. His first engines were designed by a clever engineer, Anton Pruckner, who left at the end of 1901, after which Whitehead himself became solely responsible for them. It was stated that the Wrights visited the Whitehead plant in Bridgeport, Connecticut, and that Wilbur remained for several days, spending his time in their machine shop. This was not only categorically denied by Orville Wright when he heard of it but it is quite obvious that the 1903 or any other of the Wright engine designs bears little resemblance to Pruckner's work. In fact, its principal design features are just the opposite of Pruckner's, who utilized vertical cylinders, the 2-stroke cycle, and air-cooling, which Whitehead at some point changed to water-cooling.[15] [Footnote 15: Considerable doubt surrounds Whitehead's actual flight accomplishments, but Pruckner's engines were certainly used, as several were sold to early pioneers, including Charles Wittemann. It is probable that the specific power output was not very great, for the air-cooled art of this time was not very advanced and Pruckner had a rather poor fin design. But the change to water cooling eliminated this trouble, and the engines were most simple, should have been relatively quite light, and with enough development could probably have been made into sufficiently satisfactory flying units for that period.] The Four-Cylinder Vertical Demonstration Engine and the First Production Engine In 1906, while still doing general development work on the flat experimental engine, the Wrights started two new engines, and for the first time the brothers engaged in separate efforts. One was "a modification of the old ones" by Wilbur and the other, "an entirely new pattern" by Orville. There is no record of any of the features of Wilbur's project or what was done in connection with it. Two months after the experimental operation of the two designs began, an entry in Wilbur's diary gives some weight and performance figures for the "4" x 4" rebuilt horizontal," and since Orville's design was vertical the data clearly refer to Wilbur's; but since the output is given only in test-fan rpm it does not serve to indicate what had been accomplished and there is no further mention of it. Orville's design became the most used of any model they produced. It saw them through the years from 1906 to 1911 or 1912, which included the crucial European and United States Army demonstrations, and more engines of this model were manufactured than any of their others including their later 6-cylinder. Although its ancestry is traceable to the original 1903 engine, the design form, particularly the external configuration, was considerably altered. Along with many individual parts it retained the basic conception of four medium-size cylinders positioned in line and driving the propellers through two sprocket wheels. From the general tenor of the record it would seem, despite there being no specific indication, that from this time on Orville served as the leader in engine design, although this occurred with no effect whatsoever on their finely balanced, exactly equal partnership which endured until Wilbur's death in 1912. The first major change from the 1903 design, putting the engine in an upright instead of flat position, was probably done primarily to provide for a minimum variation in the location of the center of gravity with and without a passenger. Whether or not it had any influence, the vertical cylinder arrangement was becoming predominant in automobile powerplants by this time, and the Wright engines now began to resemble this prevailing form of the internal combustion engine--a basic form that, in a wide variety of uses, was to endure for a long time. Over the years, the Wrights seem to have made many changes in the engine: the bore was varied at different times, rod assembly methods were altered, and rod ends were changed from bronze to steel. Chenoweth states that on later engines an oil-control ring was added on the bottom of the piston, necessitating a considerable increase in the length of the cylinder barrel. This arrangement could not have been considered successful, as it apparently was applied to only a limited number of units and was not carried over to the later 6-cylinder engine model. There was much experimentation with cam shapes and most probably variations of these got into production. With the crankcase, they did not go all the way to the modern two-piece form but instead retained the one-piece construction. Assembly was effected through the ends and a detachable plate was provided on one side for access to the interior. It is clear that they regarded this ability to get at the interior of the case without major disassembly as a valuable characteristic, and later featured it in their sales literature. They were apparently willing to accept the resultant weakening of the case and continued the construction through their last engine model. The integrally cast cylinder water jackets were abandoned and the top of the crankcase was machined flat to provide a mounting deck for individual cylinders. The use of aluminum alloy was continued, and the interior of the case was provided with strengthening webs of considerable thickness, together with supporting ribs. The cam shaft was supported directly in the case. The individual cylinder design was of extreme simplicity, a single iron casting embodying everything except the water jacket. The valves seated directly on the cast-iron cylinder head and the guides and ports were all contained in an integral boss on top of the head. The exhaust valve location on the side of the engine opposite the pilot was a decided advantage over that of the 1903 design, where the exhaust was toward the pilot. A four-cornered flange near the bottom of the cylinder provided for fastening it to the crankcase, and a threaded hole in the top of the head received a vertical eyebolt which served as the rocker-arm support. The cylinder was machined all over; two flanges, one at the bottom and the other about two-thirds of the way down provided the surfaces against which the water jacket was shrunk. The jacket was an aluminum casting incorporating the necessary bosses and double shrunk on the barrel; that is, the jacket itself was shrunk on the cylinder-barrel flanges and then steel rings were shrunk on the ends of the jacket over the flanges. The jacket thickness was reduced by machining at the ends, making a semigroove into which the steel shrink rings fitted. These rings insured the maintenance of a tight joint despite the tendency of the aluminum jacket to expand away from the cast-iron barrel. [Illustration: _Figure 9._--4-Cylinder vertical engine: a, magneto side; b, valve port side with intake manifold removed; c, flywheel end of engine at Carillon Park Museum, Dayton, Ohio; d, magneto side with crankcase cover removed. (Photos: a, Smithsonian A-3773; b, d, Pratt & Whitney D-15003, 15007; c, by A. L. Rockwell.)] Why the one-piece crankcase and cylinder jacket combination of the 1903 engine was abandoned for the individual cylinder construction can only be surmised. The difference in weight was probably slight, as the inherent weight advantage of the original crankcase casting was largely offset by the relatively heavy valve boxes, and the difference in the total amount of machining required, because of the separate valve boxes, cages, and attaching parts, also was probably slight. Although the crankcase had shown itself to be structurally weak, this could have been cared for by proper strengthening. The 1903 design did have some fundamental disadvantages: it required a fairly complex pattern and expensive casting, plus some difficult machining, part of which had to be very accurate in order to maintain both gas and water joints tight; and the failure of any one cylinder that affected the jacket meant a complete crankcase replacement. It seems probable that a change was initially made mandatory by their intention to utilize the ported exhaust feature, the value of which they had proved in the experimental engine. The separate one-piece water jacket construction they had arrived at in this engine was available, but once the decision to change was made, the individual cylinder with its shrunk-on jacket had much to commend it--simplicity, cost, ease of manufacture and assembly and attachment, and serviceability. The advantages of the auxiliary, or ported, exhaust were not obtained without cost, however, as the water jacket around the barrel could not very easily be extended below the ports. Thus, even though the water was carried as high as possible on the upper end, a large portion of the barrel was left uncooled, and the lack of cooling at the lower end, in conjunction with the uncooled portion of the head, meant that only approximately half the entire cylinder surface was cooled directly. The piston was generally the same as in the 1903 engine, except that six radial ribs were added on the under side of the head, tapering from maximum thickness at the center to nothing near the wall. They were probably incorporated as an added path for heat to flow from the center of the piston toward the outside, as their shape was not the best use of material for strength. The piston pin was locked in the piston by the usual set screw, but here no provision was made for the alternate practice of clamping the rod on the pin. This piston-pin setscrew construction had become a standard arrangement in automobile practice. The piston rings were the normal wide design of that time, with what would now be considered a low unit pressure. Quite early in the life of this engine model the practice was initiated of incorporating shallow grooves in the surface of the more highly loaded thrust face of the piston below the piston pin to provide additional lubrication. This development apparently proceeded haphazardly. Figure 10c shows three of the pistons from an engine of low serial number--the first of this model to be delivered to the U.S. Navy--and it will be noted that one has no grooves, another has one, and the other has three. The eventual standardized arrangement provided three of these grooves, approximately 1/16 in. wide, extending halfway around the piston, and, although the depth was only a few thousandths of an inch, the amount of oil carried in them was apparently sufficient to assist in the lubrication of the face, as they were used in both the 4-and 6-cylinder engines. Each cylinder was fastened to the crankcase by four nuts on studs driven into the aluminum case. Valves and rocker arms were similar to those of the early engines, the automatic inlet valve being retained. The continued use of the two-piece valve is not notable, even though one-piece forgings were available and in use at this time; the automobile continued for many years to use this construction. The camshaft was placed at the bottom of the engine, inside the crankcase, and the rocker arms were actuated by pushrods which were operated by hinged cam followers. The pushrod was fastened in the rocker by a pin, about which it operated, through its upper end and was positioned near the bottom by a guide in the crankcase deck. The lower end of the rod bore directly on the flat upper surface of the cam follower, and valve clearance adjustment was obtained by grinding this end. The camshaft and magneto were driven by the crankshaft through a three-member train of spur gears (see Figures 9, 10 and 11). The built-up construction of the connecting rod was carried over from the first engine, and in the beginning apparently the same materials were used, except that the big end was babbited. Later the rod ends were changed from bronze to steel. The big end incorporated a small pointed scupper on one side for lubrication, as with the original, and this was sometimes drilled to feed a groove which carried oil to the rod bearing, but where the drilling was omitted, the only function the scupper then could perform was, as in the original engine, to throw a small amount of oil on the cylinder wall. The crankshaft and flywheel were similar in design to those on the 1903 engine, except that the sharp corners at the top and bottom of the crank cheeks were machined off to save weight (see Figure 10f). An oil pump and a fuel pump were mounted side by side in bosses cast on the valve side of the crankcase; they were driven from the camshaft by worm gears and small shafts crossing the case. [Illustration: _Figure 10._--4-Cylinder vertical engine: a, cylinder assembly with valve mechanism parts; b, cylinder disassembled, and parts; c, pistons and connecting rods; d, bottom side of piston; e, crankshaft, flywheel and crankcase end closure; f, crankcase, with compression release parts. (Pratt & Whitney photos D-14996, 15001, 14998, 14994, 14999, 14989, respectively.)] The camshaft construction was considerably altered from the 1903 design. Although the reason is not entirely clear, one indication suggests that breakage or distortion of the shaft may have been encountered: whereas in the 1903 engine there had been no relationship between the location of the cams and the camshaft bearings, in this engine the exhaust valves were carefully positioned so that all cams were located very close to the supporting bearings in the crankcase. Also, the camshaft was solid, although it would seem that the original hollow shaft construction could have provided equal stiffness with less weight. The final decision was possibly determined by the practicality that there existed no standard tubing even approximating the size and wall thickness desired. There still was no carburetor, a gear pump metering the fuel in the same manner as on the 1904-1905 engine. Basically, the intake charge was fed to the cylinders by a round gallery manifold running alongside the engine. This was split internally by a baffle extending almost from end to end, so that the fuel mixture entering the manifold on one side of the baffle was compelled to travel to the two ends before it could return to the inside cylinder, this feature being a copy of their 1903 general intake arrangement. Apparently various shapes and positions of entrance pipes with which to spray the fuel into the manifold were used; and the injection arrangement seems also to have been varied at different times. The fuel pump was not necessarily always used, as the engine in some of the illustrations did not incorporate one, the fuel apparently being fed by gravity, as on the original engine. Chenoweth describes an arrangement in which exhaust heat was applied to the inlet manifold to assist the fuel vaporization process, but it is believed that this was one of the many changes made in the engine during its lifetime and not necessarily a standard feature. A water circulation pump was provided, driven directly by the crankshaft through a two-arm universal joint intended to care for any misalignment between the shaft and the pump. The water was piped to a horizontal manifold running along the cylinders just below the intake manifold, and a similar manifold on the other side of the engine collected it for delivery to the radiator. It is a little difficult to understand why it was not introduced at the bottom of the water jackets. The crankcase was a relatively strong and well proportioned structure with three heavy strengthening ribs running from side to side, its only weakness being the one open side. A sheet-iron sump was fastened to the bottom by screws and it would appear from its design, method of attachment, and location of the engine mounting pads that this was added some time after the crankcase had been designed; but if so it was apparently retrofitted, as engines with quite low serial numbers have this part. The ignition was by high-tension magneto and spark plug and this decision to change from the make-and-break system was undoubtedly the correct one, just as adoption of the other form originally was logical under the circumstances that existed then. The high-tension system was simpler and had now collected more service experience. The magneto was driven through the camshaft gear, and a shelf, or bracket, cast as an integral part of the case, was provided for mounting it. The spark advance control was in the magneto and, since spark timing was the only means of regulating the engine power and speed, a wide range of adjustment was provided. The engine had the controllable compression release which had been added to the _No. 2_ and _No. 3_ flat engines, although mechanically it was considerably altered from the original design. Instead of the movable stop operating directly on the rocker roller to hold the exhaust valve open, it was located underneath a collar on the pushrod. This stop was hinged to the crankcase and actuated by a small rod running along and supported by the crankcase deck. Longitudinal movement of this rod in one direction would, by spring pressure on each stop, push them underneath the collars as the exhaust valves were successively opened. A reverse movement of the rod would release them (see Figure 10f). Why they retained the method of manually operating the compression release, which was the same as had been used in the 1904-1905 engine, is not quite clear. That is, the mechanism was put into operation by pulling a wire running from the pilot to a lever actuating the cam which moved the control rod. When normal valve operation was subsequently desired, the pilot was compelled to reach with his hand and operate the lever manually, whereas a second wire or push-pull mechanism would have obviated the necessity for both the awkward manual operation of the lever and the gear guard which was added to protect the pilot's hand, the lever being located close to the camshaft gear. The 4-cylinder vertical engine was a considerable improvement over the previous designs. They had obtained a power increase of about 40 percent, with a weight decrease of 10 percent, and now had an engine whose design was almost standard form for good internal combustion engines for years to come. In fact, had they split the crankcase at the crankshaft center line and operated the inlet valves mechanically, they would have had what could be termed a truly modern design. They needed more cylinder cooling, both barrel and head, particularly the latter, and an opened-up induction system for maximum power output, but this was not what they were yet striving for. They had directly stated that they were much more interested in reliability than light weight. This engine model was the only one of the Wright designs to be licensed and produced abroad, being manufactured in Germany by the Neue Automobil-Gesellschaft and by Bariquand et Marré in France. The latter was much more prominent and their engines were used in several early European airplanes. [Illustration: _Figure 11._--4-Cylinder vertical engine assembly, Bariquand et Marré version. (Drawing courtesy Bristol Siddeley Engines, Ltd.)] [Illustration: THE WRIGHT BROTHERS AERO ENGINE] The French manufacturer, without altering the basic design, made a number of changes of detail which seem to have greatly annoyed Wilbur Wright, although some of them could probably be listed as improvements, based on several features of later standard design. One consisted of an alteration in the position of the fuel and oil pumps, the latter being lowered to the level of the sump. The crankcase was drilled to provide forced-feed lubrication to the connecting rod big end and crankshaft main bearings. Strengthening ribs were added to the pistons running from the upper side of the pin bosses to the piston wall, and the crankcase studs holding down the cylinders were replaced with bolts having their heads inside the case. The hinged cam follower was omitted and the pushrod bore directly on the cam through a roller in its end. The magneto was moved toward the rear of the engine a considerable distance and an ignition timing control device was introduced between it and its driving gear. Instead of the magneto being mounted directly on the special bracket integral with the crankcase, a wooden board running from front to rear of the engine was used and this was fastened to the two engine support pads, the magneto bracket being omitted entirely. Despite his criticism of the French motor and the quality of its manufacture, Wilbur was compelled to install one in his own exhibition airplane during his early French demonstrations at Le Mans after rod failure had broken his spare crankcase, and much of his subsequent demonstration flying was made with the French product. The Eight-Cylinder Racing Engine By 1909 regular and special air meets and races were being held and various competitions for trophies conducted. Among these the Gordon Bennett Cup Race for many years was considered a major event. For the 1910 competition it was decided to enter a Wright machine and, since this was a race with speed the sole objective, the available 4-cylinder engine, even in a version pushed to its maximum output, was deemed too small. They built for it a special 8-cylinder unit in a 90°V form. They were thus resorting to one of their 1904 concepts--modifying and enlarging a version known and proved in use--as the proper method of most quickly increasing output. Unfortunately again, there are essentially no detailed drawings available, so that the design cannot be studied.[16] [Footnote 16: A drawing of the camshaft is held by The Franklin Institute.] Only one engine is historically recorded as having been built, although in view of the Wrights' record of foresight and preparation it is almost certain that at least one spare unit, assembled or in parts, was provided. In any case, the airplane--it was called the _Baby Grand Racer_--and engine were wrecked just before the race, and no physical parts were retained, so that the sole descriptions come from external photographs, memory, and hearsay. McFarland thinks that possibly Orville Wright, particularly, was somewhat discomfited over the accident that eliminated the machine, as he had previously flown it quite successfully at a speed substantially higher than that of the ultimate winner, and he wanted to get it out of sight and mind as quickly as possible. The Air Force Museum at Wright Field, Dayton, Ohio, has an incomplete set of drawings of a 90°V, 8-cylinder Wright engine, but it is quite obvious from the basic design and individual features, as well as from at least one date on the drawings, that this conception is of a considerably later vintage than that of the _Baby Grand Racer_. The racing engine was in essence a combination of two of the standard 4s on a redesigned crankcase utilizing as many of the 4-cylinder engine parts as possible. The rods were reported to have been placed side by side, and the regular 4-cylinder crankshaft, with alterations to accommodate the rods, was utilized. A single cam operated all the exhaust valves. It was compact and light, its only fundamental disadvantage being the inherent unbalance of the 90°V-8. The arrangement provided a much higher powered unit in the cheapest and quickest manner, and one that could be expected to operate satisfactorily with the least development. The Six-Cylinder Vertical Engines Shortly after the construction of the 8-cylinder engine the Wrights were again faced with the ever-recurrent problem of providing a higher powered standard production engine for their airplanes, which were now being produced in some numbers. By this time, 1911, there had been a relatively tremendous growth in both flying and automotive use of the internal combustion engine and as a result many kinds and sizes had been produced and utilized, so that numerous choices were presented to them. But if they were both to make use of their past experience and retain the simplicity they had always striven for, the more practical possibilities narrowed down to three: they could increase the cylinder size in the 4-cylinder combination, or they could go either to 6 or 8 cylinders in the approximate size they had previously used. [Illustration: _Figure 12._--Original 6-cylinder engine: a, push-rod side; b, valve-port side; c, crankcase with sump removed. (Photos: Smithsonian A-3773A, 45598; Pratt & Whitney D-15015, respectively.)] The 4-in. cylinder in combination with a 5-in. stroke would provide in four cylinders about the displacement they wanted. Strokes of 6 in. were not uncommon and cylinders of 6-in. bore had been very successfully utilized in high-output automobile racing engines many years before this, so there was seemingly no reason to doubt that the 5-in. cylinder could be made to operate satisfactorily, but it is not difficult to imagine the Wrights' thoughts concerning the roughness of an engine with cylinders of this diameter. The question of the grade of available fuel may possibly have entered into their decision to some extent, but it seems far more likely that roughness, their perennial concern, was the predominant reason for not staying with the more simple 4-cylinder form (as we have seen, roughness to them meant the effect of the cylinder explosion forces). Actually, of course, they never went larger than a 4-3/8-in. cylinder bore, and later aircraft engine experience would seem generally to confirm their judgment, for with the piston engine it has always been much more difficult to make the larger bores operate satisfactorily at any given specific output. While the 90°V, 8-cylinder arrangement would have enabled them to utilize a great number of the 4-cylinder-engine parts, it would have given them a somewhat larger engine than was their apparent desire, unless they reduced the cylinder size. And while they had had some limited experience in building and operating this kind of engine, and twice had chosen it when seeking more power, both of these choices were greatly influenced by the desire to obtain quickly an engine of higher power. It is also possible that something in their experience with the V-8 moved them away from it; the unbalanced shaking force inherent in the arrangement may well have become evident to them. What probably also helped them to their final conclusion was the fundamental consideration that the V-8 provided two extra cylinders which were not really needed. The eventual selection of the 6-cylinder was a slight compromise. In order to get the desired output the cylinder displacement was increased, but this was done by lengthening the stroke--the first time this had been altered since the original design. The increase (from 4 to 4-1/2 in.) was only 1/2 in., and the bore, the more important influence on fuel performance, was kept the same. Overall, the choice was quite logical. They were utilizing the in-line construction upon which almost all of their now considerable experience had been based, and the sizes of and requirements for parts also conformed to this experience. They could, in fact, use many of the same parts. The natural balance of the 6-cylinder arrangement gave them a very smooth engine, and had they stiffened the shaft and counter-weighted the cranks, they would have produced the smoothest engine that could have been built at that time. In the literature are two references to a Wright 6-cylinder engine constructed around the cylinders of the vertical 4. One of these is in Angle's _Airplane Engine Encyclopedia_, published in 1921, and the other is in _Aerosphere 1939_, published in 1940. The wording of the latter is essentially identical with that of the former; it seems a reasonable conclusion that it is a copy. Although it is possible that such an engine was built at some time, just as the 8-cylinder racing engine was cobbled up out of parts from the 4-cylinder vertical, no other record, no engines, and no illustrations have been found. It is thus quite certain that no significant quantity was ever manufactured or utilized. The crankcase was considerably changed from that of the vertical 4, and was now in two pieces, with the split on the crankshaft center line. However, the shaft was not supported by the lower half of the case, as eventually became standard practice, but by bearing caps bolted to the ends of the upper case and, in between, to heavy ribs running across the upper case between the cylinders. The lower half of the case thus received none of the dynamic or explosion loads, and, serving only to support the engine and to provide for its mounting, was lightly ribbed. In it were incorporated integral-boss standpipe oil drains which discharged into a bolted-on sump. The upper half of the case was again left open on one side, giving the desired access to the interior, and, additionally, the design was altered to provide a method of camshaft assembly that was much simpler than that of the vertical 4 (see p. 42). The cylinder was also greatly altered from that of the vertical 4. It was made in three parts, a piece of seamless steel tubing being shrunk on a cast-iron barrel to form the water jacket, with a cast-iron cylinder head shrunk on the upper end of the barrel. This construction compelled the use of long studs running from the cylinder head to the case for fastening down the cylinder (see Figures 12a-c). For the first time the cylinder heads were water-cooled, cored passages being provided, and more barrel surface was jacketed than previously, although a considerable area at the bottom was still left uncooled, obviously by direct intent, as the ported exhaust arrangement was no longer employed. Also for the first time one-piece forged valves were used, but just when these were incorporated is not certain and, surprisingly, they were applied to the inlet only, the exhaust valve being continued in the previous two-piece screwed and riveted construction. The reasoning behind this is not evident. If a satisfactory two-piece exhaust valve had finally been developed it would be logical to carry it over to the new design; but exhaust valves normally being much more troublesome, it would seem that a good exhaust valve would make an even better inlet valve and, in the quantities utilized, the two-piece design should have been much cheaper. In the original 6-cylinder engine the inlet valves operated automatically as in all previous models, but at the time of a later extensive redesign (1913) this was changed to mechanical actuation, and the succeeding engines incorporated this feature. All the valve-actuating mechanism was similar to that of the vertical 4, and the engine had the usual compression-release mechanism, the detail design being carried over directly from the 4-cylinder. Design of the piston followed their previous practice, with wide rings above the pin and shallow grooves below the pin on the thrust face, and with the pin fastened in the piston by a set screw. The piston had four ribs underneath the head (see Figure 13b) radiating from the center and with the two over the pin bosses incorporating strengthening webs running down and joining the bosses. The piston length was reduced by 1 in., thus giving a much less clumsy appearance and, with other minor alterations, a weight saving of 40 percent (see Figures 13b and c). The rods were for the first time made of I-section forgings, a major departure, machined on the sides and hand finished at the ends, with a babbit lining in the big end, the piston pin bearing remaining steel on steel. [Illustration: _Figure 13._--Original 6-cylinder engine: a, cylinder assembly and valve parts; b, bottom side of piston; c, piston, piston pin and connecting rod; d, valve mechanism; e, crankshaft and flywheel. (Pratt & Whitney photos D-15012, 15017, 15013, 15018, respectively.)] At least two different general carburetion and induction systems were utilized, possibly three. One, and most probably the original, consisted of a duplicate of the injection pump of the 4-cylinder fitted to a manifold which ran the length of the engine, with three takeoffs, each of which then split into two, one for each cylinder. Of this arrangement they tried at least two variations involving changes in the location and method of injecting the fuel into the manifold; and there seems to have been an intermediate manifold arrangement, using fuel-pump injection at the middle of the straight side, or gallery, manifold, which was fed additional air at both ends through short auxiliary inlet pipes. This would indicate that with the original arrangement, the end cylinders were receiving too rich a mixture, when the fuel in the manifold was not properly vaporized. Although the exhaust was on the same side of the engine as the inlet system, no attempt was made to heat the incoming charge at any point in its travel. An entirely different system adopted at the time of the complete redesign in 1913 consisted of two float-feed Zenith carburetors each feeding a conventional three-outlet manifold. This carburetor was one of the first of the plain-tube type, that is, with the airflow through a straight venturi without any spring-loaded or auxiliary air valves, and was the simplest that could be devised. When properly fitted to the engine, it gave a quite good approximation of the correct fuel and air mixture ratio over the speed-load running range, although it is considerably more than doubtful that this was maintained at altitude, as is stated in one of the best descriptions of the engine published at the time the carburetors were applied. The compression ratio of this engine was lowered by almost 20 percent from that of the vertical 4. This, in combination with the low bore-to-stroke ratio, the unheated charge, and the later mechanically operated inlet valve, indicates that the Wrights were now attempting for the first time to secure from an engine something approaching the maximum output of which it was capable. As the engine originally came out, it continued to utilize only one spark plug in each cylinder. The high-tension magneto had a wide range of spark advance adjustment, which again provided the only control of the engine when equipped with the original fuel pump injection. The location of the valves and pushrods was similar to that in the 4, so that the cams were immediately adjacent to the camshaft bearings, which were carried in the crankcase ends and in the heavy webs. The camshaft was gear-driven and the cam shape was similar to that of the last 4s, with a quite rapid opening and closing and a long dwell, leaving the valve opening accelerations and seating velocities still quite high. The crankshaft was a continuation of their basic design of rather light construction, particularly in the webs. The cheeks were even thinner (by 1/4 in.) than those of the 4 although the width was increased by 1/8 in. (see Figure 13e). For the first time they went to a forging, the rough contour type of the time, and utilized a chrome-nickel alloy steel. Lubrication was by means of the usual gear pump, and the piston and rod bearings continued to be splash-fed. The rod big-end bearing carried a small sharp undrilled boss at the point where, on the other engines, had been located scuppers whose purpose was apparently still to throw lubricating oil on the cylinder wall carrying the more highly loaded side of the piston. The rod big-end bearing was lubricated by a hole on the top of the big-end boss catching some of the crankcase splash, which was then carried to the bearing by a groove. When the 6-cylinder engine was completely redesigned in 1913 this led to the introduction in late fall of that year of a new model called the 6-60, the 60 designating the rating in horsepower. There is little in the Wright records to show why such a radical revision was thought necessary, but the general history of the period gives a rather clear indication. The competition had caught up to the Wrights in powerplants. Other engines were being installed in Wright airplanes, and Navy log books show these other engines being used interchangeably with those of the Wrights. Most of the descriptions of the new model published at the time it was introduced concentrate on the addition of the two carburetors and the mechanical operation of the inlet valves, but these were only two of many major changes. The cylinder was completely revised, the intake being moved to the camshaft side of the engine from its position adjacent to the exhaust, so that the two ports were now on opposite sides of the cylinder. By proper positioning of the rocker-arm supports and choice of their length and angles, all valves were made operable from a single camshaft. The shrunk-on steel water jacket cylinder was retained, but the water connections were repositioned so that the water entered at the bottom and came out at the top of the cylinder. Over the life of the 6-cylinder engine several different valve types were used but the published specifications for the model 6-60 called for "cast iron heads"--the old two-piece construction. The piston pins were case hardened and ground and the crankshaft pins and journals were heat treated and ground. The fuel and oil pumps were removed from the side of the crankcase and a different ignition system was applied, although still of the high-tension spark-plug type which by this time had become general practice on all so-called high-speed internal-combustion engines. A second threaded spark-plug hole was provided in the cylinder head and despite its more common use for other purposes, it is evident that the intention was to provide two-plug ignition. It is doubtful that at the specific output of this engine any power difference would be found between one-and two-plug operation, so that the objective was clearly to provide a reserve unit in case of plug failure. However, it was also used for the installation of a priming cock for starting and because of the prevalence of single-wire ignition systems on existing and illustrated engines, it seems to have been used mostly in this manner, even though dual-ignition systems later became an unvarying standard for aircraft engines. Viewed externally, the only part of the engine that appears the same as the original 6 is the small lower portion of the crankcase; but what is more visually striking is the beauty of the new lines and extreme cleanness of the exterior design (see Figures 14 and 15). Many of their individual parts had shown the beauty of the sparse design of pure utility but it was now in evidence in the whole. Despite the proven practical value of their other models, this is the only one that can be called a good-looking engine, instantly appealing to the aesthetic sense, even though the vertical 4 is not an ugly engine. The appearance of their final effort, in a field they were originally reluctant to enter and concerning which they always deprecated the results of their own work, was a thing of which a technically trained professional engine designer could be proud. The 6-60 was continued in production and development until it became the 6-70, and indications are that it eventually approached an output of 80 horsepower. [Illustration: _Figure 14._--6-Cylinder 6-60 and 6-70 engine, right rear intake side. (Pratt & Whitney photo.)] [Illustration: _Figure 15._--6-Cylinder 6-70 engine, incorporating flexible flywheel drive, exhaust side. (Smithsonian photo A-54381.)] Minor Design Details and Performance of the Wright Engines In the Wright brothers' various models were many minor design items which altogether required a great deal of consideration, but which did not materially affect overall engine performance. The results generally could all be classed as good practice; however, one of these utilized in the 4-cylinder vertical engine was rather unorthodox and consisted of offsetting the cylinders with relation to the crankshaft. This arrangement, which can be seen in the drawing (Figure 11) was apparently an attempt to reduce the maximum side load on the piston during the power stroke, but since the peak gas loading usually occurs at about 10 to 15 percent of the power stroke, this probably did not have much effect, and it was not carried over to the 6-cylinder design. All engine bearings were of the plain sleeve type and, except for the bronze and steel bearings in the connecting rod, were of babbit. The advantages of babbit for bearings were discovered very early in the development of the mechanical arts, and apparently the Wrights never encountered a bearing loading sufficiently high to cause a structural breakdown in this relatively weak material. Valve openings show no variation through the successive production engines, although the Wrights most probably experimented with different amounts. The 1903 engine and the vertical 4-and 6-cylinder all had lifts of 5/16 in., but the valve-seat angles varied somewhat; the records show included angles of 110° to 90°--not a large difference. The valve-operating mechanism was the same from the first vertical 4 onward. The high side thrust caused by the cam shape required for the very rapid valve opening they chose was, no doubt, the reason for the use of the hinged cam follower, and since the same general cam design was used in their last engine, the 6-cylinder, the same method of operation which had apparently proved very serviceable was continued. How satisfactory was the considerably simpler substitute used in the Bariquand et Marré version of the 4-cylinder engine is not known. Possibly it was one of the alterations in the Wrights' design that Wilbur Wright objected to, although in principle it more closely conforms to the later fairly standard combination valve tappet and roller construction: The available drawings do indicate, however, that the cam of the Bariquand et Marré engine was also altered to give a considerably less abrupt valve opening than the Wright design, so that there was less side thrust. For the Wright 6-cylinder engine their 4-cylinder cam was slightly altered to provide a rounding off near the top of the lobe, thus providing some reduction in the velocity before maximum opening was reached. All their cam designs indicate a somewhat greater fear of the effect of seating velocities than of opening accelerations. Since the range of cylinder diameters utilized did not vary greatly, the valve sizes were correspondingly fairly uniform. The diameter of the valves for the original 4-in.-bore cylinder was 2 in., while that for the 4-3/8-in. bore used in the 6-cylinder engine was actually slightly smaller, 1-7/8 in. Possibly the Wrights clung too long to the automatic inlet valve, although it did serve them well; but possibly, as has been previously noted, there were valid reasons for continuing its use despite the inherently low volumetric efficiency this entailed. The inherent weakness in the joints of the three-piece connecting rod has been pointed out, but aside from this, the design was excellent, for all the materials and manufacturing methods required were readily available, and structurally it was very sound. Tubular rods were still in use in aircraft engines in the 1920s. The Wrights had a surprisingly thorough grasp of the metallurgy of the time, and their choice of materials could hardly have been improved upon. Generally they relied upon the more simple and commonly used metals even though more sophisticated and technically better alloys and combinations were available.[17] Case hardening was in widespread use in this period but their only utilization of it was in some parts of the drive chains purchased completely assembled and in the piston pins of their last engine. The treatment of the crankshafts of all their engines except the final 6-cylinder was typical of their uncomplicated procedure: the particular material was chosen on the basis of many years of experience with it, hardening was a very simple process, and the expedient of carrying this to a point just below the non-machinable range gave them bearing surfaces that were sufficiently hard, yet at the same time it eliminated the possibility--present in a heat-treating operation--of warping the finished piece. [Footnote 17: Baker states that the first crankshaft was made from a slab of armor plate and if this is correct the alloy was a rather complex one of approximately .30-.35 carbon, .30-.80 manganese, .10 silicon, .04 phosphorus, .02 sulphur, 3.25-3.50 nickel, 0.00-1.90 chromium; however, all the rest of the evidence, including Orville Wright's statement to Dr. Gough, would seem to show that it was made of what was called tool steel (approximately 1.0 carbon).] In the entire 1903 engine only five basic materials--excepting those in the purchased "magneto" and the platinum facing on the ignition-system firing points--were used: steel, cast iron, aluminum, phosphor bronze, and babbit. The steels were all plain carbon types with the exception of the sheet manifold, which contained manganese, and no doubt this was used because the sheet available came in a standard alloy of the time. Overall, the Wright engines performed well, and in every case met or exceeded the existing requirements. Even though aircraft engines then were simpler than they became later and the design-development time much shorter, their performance stands as remarkable. As a result, the Wrights never lacked for a suitable powerplant despite the rapid growth in airplane size and performance, and the continual demand for increased power and endurance. Few service records dating from before 1911, when the military services started keeping log books, have been found. Some of those for the period toward the end of their active era have been preserved, but for that momentous period spanning the first few years when the Wrights had the only engines in actual continuous flight operation, there seems to be essentially nothing--perhaps because there were no standard development methods or routines to follow, no requirements to be met with respect to pre-flight demonstrations or the keeping of service records. Beginning in 1904, however, and continuing as long as they were actively in business, they apparently had in progress work on one or more developmental or experimental engines. This policy, in combination with the basic simplicity of design of these engines, accounted in large measure for their ability to conduct both demonstrations and routine flying essentially whenever they chose. Time between engine overhauls obviously varied. In mid 1906 an engine was "rebuilt after running about 12 hours." This is comparatively quite a good performance, particularly when it is remembered that essentially all the "running" was at full power output. It was considerably after 1920 before the Liberty engine was redesigned and developed to the stage where it was capable of operating 100 hours between overhauls, even though it was being used at cruising, or less than full, power for most of this time. The Wrights of course met with troubles and failures, but it is difficult, from the limited information available, to evaluate these and judge their relative severity. Lubrication seems to have been a rather constant problem, particularly in the early years. Although some bearing lubrication troubles were encountered from time to time, this was not of major proportions, and they never had to resort to force-feed lubrication of the main or rod big-end bearings. The piston and cylinder-barrel bearing surfaces seem to have given them the most trouble by far, and examination of almost any used early Wright engine will usually show one or more pistons with evidence of scuffing in varying degrees, and this is also apparent in the photographs in the record. This is a little difficult to understand inasmuch as most of the time they had the very favorable operating condition of cast iron on cast iron. Many references to piston seizure or incipient seizure, indicated by a loss of power, occur, and this trouble may have been aggravated by the very small piston clearances utilized. Why these small clearances were continued is also not readily explainable, except that with no combination of true oil-scraper rings, which was the basic reason why the final form of aviation piston engine was able to reach its unbelievably low oil consumptions, their large and rather weak compression rings were probably not doing an adequate job of oil control, and they were attempting to overcome this with a quite tight piston fit.[18] In any event, they did encounter scuffing or seizing pistons and cylinder over-oiling at the same time. As late as 4 May 1908 in the Wright _Papers_ there appears the notation: "The only important change has been in the oiling. The engine now feeds entirely by splash...." [Footnote 18: Their intended piston ring tension is not known. Measurements of samples from the 4-and 6-cylinder vertical engines vary greatly, ranging from less than 1/2 lb per sq in. to almost 1-1/4 lb. The validity of these data is very questionable as they apply to parts with unknown length of service and amount of wear. It seems quite certain, however, that even when new the unit tension figure with their wide rings was only a small fraction of that of the modern aircraft piston engine.] Their troubles tended to concentrate in the cylinder-piston combination, as has been true of almost all piston engines. References to broken cylinders are frequent. These were quite obviously cylinder barrels, as replacement was common, and this again is not readily explainable. The material itself, according to Orville Wright, had a very high tensile strength, and in the 1903 engine more than ample material was provided, as the barrel all the way down to well below the attachment to the case was 7/32 in. thick. The exact location of the point of failure was never recorded, but in its design are many square corners serving as points of stress concentration. Also, of course, no method was then available for determining a faulty casting, except by visual observation of imperfections on the surface, and this was probably the more common cause. It is interesting, however, that the engine finally assembled in 1928 for installation in the 1903 airplane sent to England has a cracked cylinder barrel, the crack originating at a sharp corner in the slot provided at the bottom of the barrel for screwing it in place. Valve failures were also a continuing problem, and Chenoweth reports that a large proportion of the operating time of the 1904-1906 development engine was concentrated on attempts to remedy this trouble. None of their cams, including those of the 6-cylinder engine, evidence any attempt to effect a major reduction in seating velocities. United States Navy log books of 1912 and 1913 record many instances of inlet valves "broken at the weld," indicating that some of the earlier 6-cylinder engines were fitted with valves of welded construction. For the engineer particularly, the fascination of the Wrights' engine story lies in its delineation of the essentially perfect engineering achievement by the classic definition of engineering--to utilize the available art and science to accomplish the desired end with a minimum expenditure of time, energy, and material. Light weight and operability were the guiding considerations; these could be obtained only through constant striving for the utmost simplicity. Always modest, the Wrights seem to have been even more so in connection with their engine accomplishments. Although the analogy is somewhat inexact, the situation is reminiscent of the truism often heard in the aircraft propulsion business--few people know the name of Paul Revere's horse. Yet, as McFarland has pointed out, "The engine was in fact far from their meanest achievement." With hardly any experience in this field and only a meagerly equipped machine shop, they designed and assembled an internal combustion engine that exceeded the specifications they had laid down as necessary for flight and had it operating in a period of about two months elapsed time. The basic form they evolved during this unequalled performance carried them through two years of such successful evolutionary flight development that their flying progressed from a hop to mastery of the art. And the overall record of their powerplants shows them to have been remarkably reliable in view of the state of the internal combustion engine at that time. Appendix Characteristics of the Wright Flight Engines ------------------------------------------------------------------------- _1903 _1904-1905 _1908-1911 _1911-1915 First flight Experimental Demonstrations service_ engine[a]_ flights_ and service_ ------------------------------------------------------------------------- Cyl./Form 4/flat 4/flat 4/vertical 6/vertical Bore and stroke (in.) 4×4 4-1/8×4 4-3/8×4 4-3/8×4-1/2 Displacement (cu. in.) 201 214 240 406 Horsepower 8.25-16 15-21 28-42 50-75 RPM 670-1200 1070-1360 1325-1500 1400-1560 MEP 49-53 52-57 70-87 70-94 Weight (lb) 140-180 160-170 160-180 265-300 ------------------------------------------------------------------------- [Footnote a: Concurrently with the Wrights' first engine work, Manly was developing the engine for the Langley Aerodrome, and a comparison of the Wrights' engine development with that of Manly is immediately suggested, but no meaningful comparison of the two efforts can be drawn. Beyond the objective of producing a power unit to accomplish human flight and the fact that all three individuals were superb mechanics, the two efforts had nothing in common. The Wrights' goal was an operable and reasonably lightweight unit to be obtained quickly and cheaply. Manly's task was to obtain what was for the time an inordinately light engine and, although the originally specified power was considerably greater than that of the Wrights, it was still reasonable even though Manly himself apparently increased it on the assumption that Langley would need more power than he thought. The cost and time required were very much greater than the Wrights expended. He ended up with an engine of extraordinary performance for its time, containing many features utilized in much later important service engines. His weight per horsepower was not improved upon for many years. The Wrights' engine proved its practicability in actual service. The Manly engine never had this opportunity but its successful ground tests indicated an equal potential in this respect. A description of the Langley-Manly engine and the history of its development is contained in _Smithsonian Annals of Flight_ number 6, "Langley's Aero Engine of 1903," by Robert B. Meyer (xi+193 pages, 44 figures; Smithsonian Institution Press, 1971)] It is not possible to state the exact quantities of each engine that the Wrights produced up to the time that their factory ceased operation in 1915. Chenoweth gives an estimate, based on the recollection of their test foreman, of 100 vertical 4s and 50 6s. My estimate (see page 2) places the total of all engines at close to 200. Original Wright-built engines of all four of these basic designs are in existence, although they are rather widely scattered. The Smithsonian's National Air and Space Museum has examples of them all, including, of course, the unique first-flight engine. Their condition varies, but many are operable, or could easily be made so. Among the best are the first-flight engine and the last vertical 6, at the Smithsonian, the first vertical 6, at the United States Air Force Museum, and the vertical 4, at the Carillon Park Museum. The Wrights were constantly experimenting and altering, and this in connection with the lack of complete records makes it almost impossible to state with any certainty specific performances of individual engines at given times. Weights sometimes included accessories and at others did not. Often they were of the complete powerplant unit, including radiator and water and fuel, with no clarification. In the table, performance is given in ranges which are thought to be the most representative of those actually utilized. Occasionally performances were attained even beyond the ranges given. For example, the 4×4-in. flat development engine eventually demonstrated 25 hp at an MEP of approximately 65 psi. One important figure--the horsepower actually utilized during the first flight--is quite accurately known. In 1904 the 1904-1905 flight engine, after having been calibrated by their prony-brake test-fan method, was used to turn the 1903 flight propellers, and Orville Wright calculated this power to be 12.05 bhp by comparing the calibrated engine results with those obtained with the flight engine at Kitty Hawk when tested under similar conditions. However, since the tests were conducted in still air with the engine stationary, this did not exactly represent the flight condition. No doubt the rotational speed of the engine and propellers increased somewhat with the forward velocity of the airplane so that unless the power-rpm curve of the engine was flat, the actual horsepower utilized was probably a small amount greater than Orville's figures. The lowest power figure shown for this engine is that of its first operation. No fuel consumption figures are given, primarily because no comprehensive data have been found. This is most probably because in the early flight years, when the Wrights were so meticulously measuring and recording technical information on the important factors affecting their work, the flights were of such short duration that fuel economy was of very minor importance. After success had been achieved, they ceased to keep detailed records on very much except their first interest--the flying machine itself--and when the time of longer flights arrived, the fuel consumption that resulted from their best engine design efforts was simply accepted. The range obtained became mostly a matter of aerodynamic design and weight carried. Orville Wright quotes an early figure of brake thermal efficiency for the 1903 engine that gives a specific fuel consumption of .580 lb of fuel per bhp/hr based on an estimate of the heating value of the fuel they had. This seems low, considering the compression ratio and probable leakage past their rather weak piston rings, but it is possible. In an undated entry, presumably in 1905, Orville Wright's notebook covered fuel consumption in terms of miles of flight; one of the stated assumptions in the entry is, "One horsepower consumes .60 pounds per horsepower hour"--still quite good for the existing conditions. Published figures for the 6-60 engine centered around .67 lb/hp hr for combined fuel and oil consumption. The Wright Shop Engine Despite the fact that the Wright shop engine was not a flight unit, it is interesting both because it was a well designed stationary powerplant with several exceedingly ingenious features, and because its complete success was doubtless a major factor in the Wrights' decision to design and build their own first flight engine. Put in service in their small shop in the fall of 1901, it was utilized in the construction of engine and airframe parts during the vital years from 1902 through 1908 and, in addition, it provided the sole means of determining the power output of all of their early flight engines. By means of a prony brake, its power output was carefully measured and from this the amount of power required for it to turn certain fans or test clubs was determined. These were then fitted to the flight engines and the power developed calculated from the speed at which the engines under test would turn the calibrated clubs. Although a somewhat complex method of using power per explosion of the shop engine was made necessary by the basic governor control of the engine, the final figures calculated by means of the propeller cube law seem to have been surprisingly accurate.[19] Restored under the personal direction of Charles Taylor, it is in the Henry Ford Museum in Dearborn, Michigan, together with the shop machinery it operated. [Footnote 19: _The Papers of Wilbur and Orville Wright_, volume 2, Appendix.] The engine was a single cylinder, 4-stroke-cycle "hot-tube" ignition type. The cylinder, of cast iron quite finely and completely finned for its day, was air-cooled, or rather, air-radiated, as there was no forced circulation of air over it, the atmosphere surrounding the engine simply soaking up the dissipated heat. Although this was possibly a desirable adjunct in winter, inside the small shop in Dayton, the temperature there in summer must have been quite high at times. The operating fuel was city illuminating gas, which was also utilized to heat, by means of a burner, the ignition tube. This part was of copper, with one completely closed end positioned directly in the burner flame; the other end was open and connected the interior of the tube to the combustion chamber. The inlet valve was of the usual automatic type while the exhaust valve was mechanically operated. The fuel gas flow was controlled by a separate valve mechanically connected to the inlet valve so that the opening of the inlet valve also opened the gas valve, and gas and air were carried into the cylinder together. [Illustration: _Figure 16._--Shop engine, 1901, showing governor and exhaust valve cam. (Photo courtesy R. V. Kerley.)] The engine was of normal stationary powerplant design, having a heavy base and two heavy flywheels, one on each side of the crank. These were necessary to ensure reasonably uniform rotational speed, as, in addition to having only one cylinder, the governing was of the hit-and-miss type. It had a 6×7-in. bore and stroke and would develop slightly over 3 hp at what was apparently its normal operating speed of 447 rpm, which gives an MEP of 27 psi. The engine is noteworthy not only for its very successful operation but also because it incorporated two quite ingenious features. One was the speed-governing mechanism. As in the usual hit-and-miss operation, the engine speed was maintained at a constant value, the output then being determined by the number of power strokes necessary to accomplish this. The governor proper was a cylindrical weight free to slide along its axis on a shaft fastened longitudinally to a spoke of one of the flywheels. A spring forced it toward the center of the wheel, while centrifugal force pulled it toward the rim against the spring pressure. After each opening of the valve the exhaust-valve actuating lever was automatically locked in the valve-open position by a spring-loaded pawl, or catch. The lever had attached to it a small side extension, or bar, which, when properly forced, would release the catch and free the actuating lever. This bar was so positioned as to be contacted by the governor weight when the engine speed was of the desired value or lower, thus maintaining regular valve operation; but an excessive speed would move the governor weight toward the rim and the exhaust valve would then be held in the open position during the inlet stroke, so no cylinder charge would be ingested. Since the ignition was not mechanically timed, the firing of the charge was dependent only on the compression of the inlet charge in the cylinder, so it made no difference whether the governor caused the engine to cease firing for an odd or even number of revolutions, even though the engine was operating on a 4-stroke cycle at all times. [Illustration: _Figure 17._--Shop engine, 1901, showing operation of exhaust valve cam. (Pratt & Whitney drawing.)] The exhaust valve operating cam was even more ingenious. To obtain operation on a 4-stroke cycle and still avoid the addition of a half-speed camshaft, a cam traveling at crankshaft speed was made to operate the exhaust valve every other revolution (see Figure 17). It consisted of a very slim quarter-moon outline fastened to a disc on the crankshaft by a single bearing bolt through its middle which served as the pivot about which it moved. Just enough clearance was provided between the inside of the quarter-moon and the crankshaft to allow the passage of the cam-follower roller. The quarter-moon, statically balanced and free to move about its pivot, basically had two positions. In one the leading edge was touching the shaft (Figure 17b), so that when the cam came to the cam follower, the follower was forced to go over the top of the cam, thus opening the exhaust valve. When the cam pivot point had passed the roller, the pressure of the exhaust valve spring forced the following edge of the cam into contact with the shaft and this movement, which separated the leading edge of the cam from the shaft, provided sufficient space between it and the shaft for the roller to enter (Figure 17c). Thus, when the leading edge of the cam next reached the roller, the roller, being held against the crankshaft by the valve spring pressure (Figure 17d), entered the space between the cam and the shaft and there was no actuation of the valve. In exiting from the space, it raised the trailing edge of the cam, forcing the leading edge against the shaft (Figure 17a) so that at the next meeting a normal valve opening would take place. The cam was maintained by friction alone in the position in which it was set by the roller, but since the amount of this could be adjusted to any value, it could be easily maintained sufficient to offset the small centrifugal force tending to put the cam in a neutral position.[20] [Footnote 20: The Wrights apparently never applied for an engine patent of any kind. This no doubt grew out of their attitude of regarding the engine as an accessory and deprecating their work in this field. A reasonably complete patent search indicates that this particular cam device has never been patented, although a much more complex arrangement accomplishing the same purpose was patented in 1900, and a patent application on a cam-actuating mechanism substantially identical to that of the Wrights and intended for use in a golf practice apparatus is pending at the present time.] Bibliography ANGLE, GLENN D. Wright. Pages 521-523 in _Airplane Engine Encyclopedia, an Alphabetically Arranged Compilation of All Available Data on the World's Airplane Engines_. Dayton, Ohio: The Otterbein Press, 1921. BAKER, MAX P. The Wright Brothers as Aeronautical Engineers. _Annual Report of ... the Smithsonian Institution ... for the Year Ended June 30, 1950_, pages 209-223, 4 figures, 9 plates. BEAUMOUNT, WILLIAM WORBY. _Motor Vehicles and Motors: Their Design, Construction, and Working by Steam, Oil, and Electricity._ 2 volumes. Philadelphia: J. B. Lippincott, 1901-1902. CHENOWETH, OPIE. Power Plants Built by the Wright Brothers. _S.A.E. Quarterly Transactions_ (January 1951), 5:14-17. FOREST, FERNAND. _Les Bateaux automobiles._ Paris: H. Dunod et E. Pinat, Éditeurs, 1906. GOUGH, DR. H. J. Materials of Aircraft Construction. _Journal of the Royal Aeronautical Society_ (November 1938), 42:922-1032. Illustrated. KELLY, FRED C. _Miracle at Kitty Hawk; the Letters of Wilbur and Orville Wright._ New York: Farrar, Straus and Young, 1951. ---------- _The Wright Brothers, a Biography Authorized by Orville Wright._ New York: Harcourt, Brace & Co., 1943. KENNEDY, RANKIN. _Flying Machines: Practice and Design. Their Principles, Construction and Working._ 158 pages. London: Technical Publishing Co., Ltd., 1909. LAWRANCE, CHARLES L. _The Development of the Aeroplane Engine in the United States._ Pages 409-429 in International Civil Aeronautics Conference, Washington, D.C., 12-14 December 1928, Papers Submitted by the Delegates for Consideration by the Conference. Washington: Government Printing Office, 1928. MCFARLAND, MARVIN W. _The Papers of Wilbur and Orville Wright._ 2 volumes. New York: McGraw Hill Book Co., 1953. RENSTROM, ARTHUR G. Wilbur and Orville Wright: A Bibliography Commemorating the Hundredth Anniversary of the Birth of Wilbur Wright, April 16, 1867. Washington, D.C.: The Library of Congress [Government Printing Office], 1968. Contains 2055 entries. The 6-Cylinder 60-Horsepower Wright Motor. _Aeronautics_ (November 1913), 13(5):177-179. Wright Brothers. Pages 829-830 in _Aerosphere 1939, Including World's Aircraft Engines, with Aircraft Directory_, Glenn D. Angle, editor. New York: Aircraft Publishers, 1940. Index Angle, Glenn D., 51 _Baby Grand Racer_, 47 Baker, Max P. 1, 10, 26, 28 Bariquand et Marré, 43, 44-45, 57-58 Beaumount, William Worby, 9, 25 Bristol Siddeley Engines, Ltd., 44-45 Carillon Park Museum, Dayton, Ohio, ix, 5n, 7, 37 Chanute, Octave, 28 Chenoweth, Opie, ix, 22, 35, 42, 63 Christman, Louis P., ix, 7, 8, 28 Cole, Gilmoure N., ix Clarke, J. H., 18 Daimler-Benz A. G., ix, 10, 13 Engineers Club, Dayton, Ohio, ix, 32 Ford, Henry, 8 Ford, Henry, Museum, Dearborn, Michigan, 8, 64 Forest, Fernand, 11 Franklin Institute, Philadelphia, Pennsylvania, ix, 47 Gough, Dr. H. J., 58n Howell Cheney Technical School, Manchester, Connecticut, x, 14, 15 Kelly, Fred C, 4n Kerley, R. V., ix, 65 _Kitty Hawk Flyer_, ii, 3 Langley [Samuel P.] Aerodrome, 9, 62 Loening, Grover C, 13n Manly, Charles L., 9, 62 Maxim, Sir Hiram Stevens, 3 McFarland, Marvin W., 1, 33, 47, 61 Miller-Knoblock Manufacturing Co., South Bend, Indiana, 26 National Park Service, Cape Hatteras National Seashore, ii, ix Neue Automobil-Gesellschaft, 43 Porter, L. Morgan, ix Pratt & Whitney Aircraft Corp., v, x, 37, 40-41, 49, 52, 53, 67 Pruckner, Anton, 33 Rockwell, A. L., ix, 37 Santos-Dumont, Alberto, 11 Science Museum, London, x, 5, 6, 7, 8, 11, 21, 23, 26 Taylor, Charles E., 5, 64 United Aircraft Corp., v, x Western Society of Engineers, 2 Whitehead, Gustave, 33 Wittemann, Charles, 33n Wright, Bishop Milton (father), 28 Wright, Katherine (sister), 4 Zenith carburetor, 52 *U.S. GOVERNMENT PRINTING OFFICE: 1971--397-764 Publication in Smithsonian Annals of Flight _Manuscript_ for serial publications are accepted by the Smithsonian Institution Press, subject to substantive review, only through departments of the various Smithsonian museums. Non-Smithsonian authors should address inquiries to the appropriate department. If submission is invited, the following format requirements of the Press will govern the preparation of copy. _Copy_ must be typewritten, double-spaced, on one side of standard white bond paper, with 1-1/2" top and left margins, submitted in ribbon copy with a carbon or duplicate, and accompanied by the original artwork. Duplicate copies of all material, including illustrations, should be retained by the author. There may be several paragraphs to a page, but each page should begin with a new paragraph. Number all pages consecutively, including title page, abstract, text, literature cited, legends, and tables. A manuscript should consist of at least thirty pages, including typescript and illustrations. The _title_ should be complete and clear for easy indexing by abstracting services. Include an _abstract_ as an introductory part of the text, followed by an identification of the _author_ that includes his professional mailing address. A _table of contents_ is optional. An _index_, if required, may be supplied by the author when he returns page proof. _Headings_ are to be used discriminately and must be typed with extra space above and below. For matters of general style (including bibliography and footnotes or notes) follow _A Manual of Style_, 12th edition, University of Chicago Press, 1969. 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51481	----	FLYING MACHINES TODAY "Hitherto aviation has been almost monopolized by that much-overpraised and much-overtrusted person, 'the practical man.' It is much in need of the services of the theorist--the engineer with his mathematical calculations of how a flying machine ought to be built and of how the material used in its construction should be distributed to give the greatest possible amount of strength and efficiency." --From the _New York Times_, January 16, 1911. [Illustration: THE FALL OF ICARUS] FLYING MACHINES TODAY BY WILLIAM DUANE ENNIS _Professor of Mechanical Engineering in the Polytechnic Institute of Brooklyn_ _123 ILLUSTRATIONS_ [Illustration: VAN NOSTRAND LOGO] NEW YORK D. VAN NOSTRAND COMPANY 23 MURRAY AND 1911 27 WARREN STS. _Copyright, 1911, by_ D. VAN NOSTRAND COMPANY THE · PLIMPTON · PRESS · NORWOOD · MASS · U · S · A To MY MOTHER PREFACE Speaking with some experience, the writer has found that instruction in the principles underlying the science and sport of aviation must be vitalized by some contemporaneous study of what is being accomplished in the air. No one of the revolutionizing inventions of man has progressed as rapidly as aerial navigation. The "truths" of today are the absurdities of tomorrow. The suggestion that some grasp of the principles and a very fair knowledge of the current practices in aeronautics may be had without special technical knowledge came almost automatically. If this book is comprehensible to the lay reader, and if it conveys to him even a small proportion of the writer's conviction that flying machines are to profoundly influence our living in the next generation, it will have accomplished its author's purpose. POLYTECHNIC INSTITUTE OF BROOKLYN, NEW YORK, April, 1911. CONTENTS PAGE THE DELIGHTS AND DANGERS OF FLYING.--Dangers of Aviation.--What it is Like to Fly 1 SOARING FLIGHT BY MAN.--What Holds it Up?--Lifting Power.--Why so Many Sails?--Steering 17 TURNING CORNERS.--What Happens when Making a Turn.-- Lateral Stability.--Wing Warping.--Automatic Control.-- The Gyroscope.--Wind Gusts 33 AIR AND THE WIND.--Sailing Balloons.--Field and Speed 43 GAS AND BALLAST.--Buoyancy in Air.--Ascending and Descending.--The Ballonet.--The Equilibrator 57 DIRIGIBLE BALLOONS AND OTHER KINDS.--Shapes.-- Dimensions.--Fabrics.--Framing.--Keeping the Keel Horizontal.--Stability.--Rudders and Planes.--Arrangement and Accessories.--Amateur Dirigibles.--The Fort Omaha Plant.--Balloon Progress 71 THE QUESTION OF POWER.--Resistance of Aeroplanes.-- Resistance of Dirigibles.--Independent Speed and Time-Table.--The Cost of Speed.--The Propeller 101 GETTING UP AND DOWN; MODELS AND GLIDERS; AEROPLANE DETAILS.--Launching.--Descending.-- Gliders.--Models.--Balancing.--Weights.-- Miscellaneous.--Things to Look After 121 SOME AEROPLANES.--SOME ACCOMPLISHMENTS 143 THE POSSIBILITIES IN AVIATION.--The Case of the Dirigible.--The Orthopter.--The Helicopter.--Composite Types.--What is Promised 170 AERIAL WARFARE 189 LIST OF ILLUSTRATIONS PAGE The Fall of Icarus _Frontispiece_ The Aviator 3 The Santos-Dumont "_Demoiselle_" 4 View from a Balloon 9 Anatomy of a Bird's Wing 10 Flight of a Bird 11 In a Meteoric Shower 13 How a Boat Tacks 15 Octave Chanute 18 Pressure of the Wind 19 Forces Acting on a Kite 20 Sustaining Force in the Aeroplane 23 Direct Lifting and Resisting Forces 24 Shapes of Planes 26 Balancing Sail 28 Roe's Triplane at Wembley 30 Action of the Steering Rudder 31 Recent Type of Wright Biplane 31 Circular Flight 33 The Aileron 35 Wing Tipping 36 Wing Warping 37 The Gyroscope 39 Diurnal Temperatures at Different Heights 45 Seasonal Variation in Wind Velocities 47 The Wind Rose for Mt. Weather, Va. 49 Diagram of Parts of a Drifting Balloon 51 Glidden and Stevens Getting Away in the "_Boston_" 52 Relative and Absolute Balloon Velocities 53 Field and Speed 53 Influence of Wind on Possible Course 54 Count Zeppelin 55 Buoyant Power of Wood 57 One Cubic Foot of Wood Loaded in Water 58 Buoyant Power of Hydrogen 59 Lebaudy's "_Jaune_" 60 Air Balloon 62 Screw Propeller for Altitude Control 66 Balloon with Ballonets 67 Construction of the Zeppelin Balloon 68 The Equilibrator 69 Henry Giffard's Dirigible 71 Dirigible of Dupuy de Lome 72 Tissandier Brothers' Dirigible Balloon 73 The "_Baldwin_" 74 The "_Zeppelin_" on Lake Constance 75 The "_Patrie_" 77 Manufacturing the Envelope of a Balloon 79 Andrée's Balloon, "_L'Oernen_" 80 Wreck of the "_Zeppelin_" 82 Car of the "_Zeppelin_" 84 Stern View of the "_Zeppelin_" 86 The "_Clément-Bayard_" 87 The "_Ville de Paris_" 88 Car of the "_Liberté_" 89 The "_Zodiac No. 2_" 92 United States Signal Corps Balloon Plant at Fort Omaha 93 The "_Caroline_" 94 The Ascent at Versailles, 1783 95 Proposed Dirigible 96 The "_République_" 97 The First Flight for the Gordon-Bennett Cup 99 The Gnome Motor 102 Screw Propeller 103 One of the Motors of the "_Zeppelin_" 104 The Four-Cycle Engine 105 Action of Two-Cycle Engine 106 Motor and Propeller 108 Two-Cylinder Opposed Engine 110 Four-Cylinder Vertical Engine 110 Head End Shapes 113 The Santos-Dumont Dirigible No. 2 115 In the Bay of Monaco: Santos-Dumont 117 Wright Biplane on Starting Rail 121 Launching System for Wright Aeroplane 122 The Nieuport Monoplane 124 A Biplane 125 Ely at Los Angeles 126 Trajectory During Descent 127 Descending 128 The Witteman Glider 130 French Monoplane 132 A Problem in Steering 133 Lejeune Biplane 134 Tellier Monoplane 135 A Monoplane 137 Cars and Framework 139 Some Details 139 Recent French Machines 141 Orville Wright at Fort Myer 143 The First Flight Across the Channel 144 Wright Motor 145 Voisin-Farman Biplane 147 The Champagne Grand Prize Flight 148 Farman's First Biplane 149 The "_June Bug_" 150 Curtiss Biplane 151 Curtiss' Hydro-Aeroplane at San Diego Bay 152 Flying Over the Water 153 Blériot-Voisin Cellular Biplane with Pontoons 154 Latham's "_Antoinette_" 155 James J. Ward at Lewiston Fair 156 Marcel Penot in the "_Mohawk_" 157 Santos-Dumont's "_Demoiselle_" 159 Blériot Monoplane 160 Latham's Fall into the Channel 161 De Lesseps Crossing the Channel 163 The Maxim Aeroplane 164 Langley's Aeroplane 165 Robart Monoplane 166 Vina Monoplane 167 Blanc Monoplane 170 Melvin Vaniman Triplane 171 Jean de Crawhez Triplane 171 A Triplane 172 Giraudon's Wheel Aeroplane 175 Bréguet Gyroplane (Helicopter) 177 Wellman's "_America_" 181 The German Emperor Watching the Progress of Aviation 189 Automatic Gun for Attacking Airships 193 Gun for Shooting at Aeroplanes 197 Santos-Dumont Circling the Eiffel Tower 199 Latham, Farman and Paulhan 202 FLYING MACHINES TODAY THE DELIGHTS AND DANGERS OF FLYING Few things have more charm for man than flight. The soaring of a bird is beautiful and the gliding of a yacht before the wind has something of the same beauty. The child's swing; the exercise of skating on good ice; a sixty-mile-an-hour spurt on a smooth road in a motor car; even the slightly passé bicycle: these things have all in their time appealed to us because they produce the illusion of flight--of progress through the intangible air with all but separation from the prosaic earth. But these sensations have been only illusions. To actually leave the earth and wander at will in aerial space--this has been, scarcely a hope, perhaps rarely even a distinct dream. From the days of Dædalus and Icarus, of Oriental flying horses and magic carpets, down to "Darius Green and his flying machine," free flight and frenzy were not far apart. We were learnedly told, only a few years since, that sustention by heavier-than-air machines was impossible without the discovery, first, of some new matter or some new force. It is now (1911) only eight years since Wilbur Wright at Kitty Hawk, with the aid of the new (?) matter--aluminum--and the "new" force--the gasoline engine--in three successive flights proved that a man could travel through the air and safely descend, in a machine weighing many times as much as the air it displaced. It is only five years since two designers--Surcouf and Lebaudy--built dirigible balloons approximating present forms, the _Ville de Paris_ and _La Patrie_. It is only now that we average people may confidently contemplate the prospect of an aerial voyage for ourselves before we die. A contemplation not without its shudder, perhaps; but yet not altogether more daring than that of our grandsires who first rode on steel rails behind a steam locomotive. The Dangers of Aviation We are very sure to be informed of the fact when an aviator is killed. Comparatively little stir is made nowadays over an automobile fatality, and the ordinary railroad accident receives bare mention. For instruction and warning, accidents to air craft cannot be given too much publicity; but if we wish any accurate conception of the danger we must pay regard to factors of proportion. There are perhaps a thousand aeroplanes and about sixty dirigible balloons in the world. About 500 men--amateurs and professionals--are continuously engaged in aviation. The Aero Club of France has issued in that country nearly 300 licenses. In the United States, licenses are held by about thirty individuals. We can form no intelligent estimate as to the number of unlicensed amateurs of all ages who are constantly experimenting with gliders at more or less peril to life and limb. A French authority has ascertained the death rate among air-men to have been--to date--about 6%. This is equivalent to about one life for 4000 miles of flight: but we must remember that accidents will vary rather with the number of ascents and descents than with the mileage. Four thousand miles in 100 flights would be much less perilous, under present conditions, than 4000 miles in 1000 flights. [Illustration: THE AVIATOR] There were 26 fatal aeroplane accidents between September 17, 1908, and December 3, 1910. Yet in that period there were many thousands of ascents: 1300 were made in one week at the Rheims tournament alone. Of the 26 accidents, 1 was due to a wind squall, 3 to collision, 6 (apparently) to confusion of the aviator, and 12 to mechanical breakage. An analysis of 40 British accidents shows 13 to have been due to engine failures, 10 to alighting on bad ground, 6 to wind gusts, 5 to breakage of the propeller, and 6 to fire and miscellaneous causes. These casualties were not all fatal, although the percentage of fatalities in aeronautic accidents is high. The most serious results were those due to alighting on bad ground; long grass and standing grain being very likely to trip the machine and throw the occupant. French aviators are now strapping themselves to their seats in order to avoid this last danger. [Illustration: THE SANTOS-DUMONT "DEMOISELLE" (From _The Aeroplane_, by Hubbard, Ledeboer and Turner)] Practically all of the accidents occur to those who are flying; but spectators may endanger themselves. During one of the flights of Mauvais at Madrid, in March of the present year, the bystanders rushed through the barriers and out on the field before the machine had well started. A woman was decapitated by the propeller, and four other persons were seriously injured. Nearly all accidents result from one of three causes: bad design, inferior mechanical construction, and the taking of unnecessary risks by the operator. Scientific design at the present writing is perhaps impossible. Our knowledge of the laws of air resistance and sustention is neither accurate nor complete. Much additional study and experiment must be carried on; and some better method of experimenting must be devised than that which sends a man up in the air and waits to see what happens. A thorough scientific analysis will not only make aviation safer, it will aid toward making it commercially important. Further data on propeller proportions and efficiencies, and on strains in the material of screws under aerial conditions, will do much to standardize power plant equipment. The excessive number of engine breakdowns is obviously related to the extremely light weight of the engines employed: better design may actually increase these weights over those customary at present. Great weight reduction is no longer regarded as essential at present speeds in aerial navigation: we have perhaps already gone too far in this respect. Bad workmanship has been more or less unavoidable, since no one has yet had ten years' experience in building aeroplanes. The men who have developed the art have usually been sportsmen rather than mechanics, and only time is necessary to show the impropriety of using "safety pins" and bent wire nails for connections. The taking of risks has been an essential feature. When one man earns $100,000 in a year by dare-devil flights, when the public flocks in hordes--and pays good prices--to see a man risk his neck, he will usually aim to satisfy it. This is not developing aerial navigation: this is circus riding--looping-the-loop performances which appeal to some savage instinct in us but lead us nowhere. Men have climbed two miles into the clouds, for no good purpose whatever. All that we need to know of high altitude conditions is already known or may be learned by ascents in anchored balloons. Records up to heights of sixteen miles have been obtained by sounding balloons. If these high altitudes may under certain conditions be desirable for particular types of balloon, they are essentially undesirable for the aeroplane. The supporting power of a heavier-than-air machine decreases in precisely inverse ratio with the altitude. To fly high will then involve either more supporting surface and therefore a structurally weaker machine, or greater speed and consequently a larger motor. It is true that the resistance to propulsion decreases at high altitudes, just as the supporting power decreases: and on this account, given only a sufficient margin of supporting power, we might expect a standard machine to work about as well at a two-mile elevation as at a height of 200 feet; but rarefaction of the air at the higher altitudes decreases the weight of carbureted mixture drawn into the motor, and consequently its output. Any air-man who attempts to reach great heights in a machine not built for such purpose is courting disaster. Flights over cities, spectacular as they are, and popular as they are likely to remain, are doubly dangerous on account of the irregular air currents and absence of safe landing places. They have at last been officially discountenanced as not likely to advance the sport. All flights are exhibition flights. The day of a quiet, mind-your-own-business type of aerial journey has not yet arrived. Exhibition performances of any sort are generally hazardous. There were nine men killed in one recent automobile meet. If the automobile were used exclusively for races and contests, the percentage of fatalities might easily exceed that in aviation. It is claimed that no inexperienced aviator has ever been killed. This may not be true, but there is no doubt that the larger number of accidents has occurred to the better-known men from whom the public expects something daring. Probably the best summing up of the danger of aviation may be obtained from the insurance companies. The courts have decided that an individual does not forfeit his life insurance by making an occasional balloon trip. Regular classified rates for aeroplane and balloon operators are in force in France and Germany. It is reported that Mr. Grahame-White carries a life insurance policy at 35% premium--about the same rate as that paid by a "crowned head." Another aviator of a less professional type has been refused insurance even at 40% premium. Policies of insurance may be obtained covering damage to machines by fire or during transportation and by collisions with other machines; and covering liability for injuries to persons other than the aviator. On the whole, flying is an ultra-hazardous _occupation_; but an _occasional_ flight by a competent person or by a passenger with a careful pilot is simply a thrilling experience, practically no more dangerous than many things we do without hesitation. Nearly all accidents have been due to preventable causes; and it is simply a matter of science, skill, perseverance, and determination to make an aerial excursion under proper conditions as safe as a journey in a motor car. Men who for valuable prizes undertake spectacular feats will be killed as frequently in aviation as in bicycle or even in automobile racing; but probably not very much more frequently, after design and workmanship in flying machines shall have been perfected. The total number of deaths in aviation up to February 9, 1911, is stated to have been forty-two. What It Is Like to Fly We are fond of comparing flying machines with birds, with fish, and with ships: and there are useful analogies with all three. A drifting balloon is like a becalmed ship or a dead fish. It moves at the speed of the aerial fluid about it and the occupants perceive no movement whatever. The earth's surface below appears to move in the opposite direction to that in which the wind carries the balloon. With a dirigible balloon or flying machine, the sensation is that of being exposed to a violent wind, against which (by observation of landmarks) we find that we progress. It is the same experience as that obtained when standing in an exposed position on a steamship, and we wonder if a bird or a fish gradually gets so accustomed to the opposing current as to be unconscious of it. But in spite of jar of motors and machinery, there is a freedom of movement, a detachment from earth-associations, in air flight, that distinguishes it absolutely from the churning of a powerful vessel through the waves. [Illustration: VIEW FROM A BALLOON] [Illustration: ANATOMY OF A BIRD'S WING (From Walker's _Aerial Navigation_)] [Illustration: FLIGHT OF A BIRD] Birds fly in one of three ways. The most familiar bird flight is by a rapid wing movement which has been called oar-like, but which is precisely equivalent to the usual movement of the arms of a man in swimming. The edge of the wing moves forward, cutting the air; on the return stroke the leading edge is depressed so as to present a nearly flat surface to the air and thus propel the bird forward. A slight downward direction of this stroke serves to impel the flight sufficiently upward to offset the effect of gravity. Any man can learn to swim, but no man can fly, because neither in his muscular frame nor by any device which he can attach thereto can he exert a sufficient pressure to overcome his own weight against as imponderable a fluid as air. If air were as heavy as water, instead of 700 times lighter, it would be as easy to fly as to swim. The bird can fly because of the great surface, powerful construction, and rapid movement of its wings, in proportion to the weight of its body. But compared with the rest of the animal kingdom, flying birds are all of small size. Helmholz considered that the vulture represented the heaviest body that could possibly be raised and kept aloft by the exercise of muscular power, and it is understood that vultures have considerable difficulty in ascending; so much so that unless in a position to take a short preliminary run they are easily captured. Every one has noticed a second type of bird flight--soaring. It is this flight which is exactly imitated in a glider. An aeroplane differs from a soaring bird only in that it carries with it a producer of forward impetus--the propeller--so that the soaring flight may last indefinitely: whereas a soaring bird gradually loses speed and descends. [Illustration: IN A METEORIC SHOWER] A third and rare type of bird flight has been called _sailing_. The bird faces the wind, and with wings outspread and their forward edge elevated rises while being forced backward under the action of the breeze. As soon as the wind somewhat subsides, the bird turns and _soars_ in the desired direction. Flight is thus accomplished without muscular effort other than that necessary to properly incline the wings and to make the turns. It is practicable only in squally winds, and the birds which practice "sailing"--the albatross and frigate bird--are those which live in the lower and more disturbed regions of the atmosphere. This form of flight has been approximately imitated in the man[oe]uvering of aeroplanes. Comparison of flying machines and ships suggests many points of difference. Water is a fluid of great density, with a definite upper surface, on which marine structures naturally rest. A vessel in the air may be at any elevation in the surrounding rarefied fluid, and great attention is necessary to keep it at the elevation desired. The air has no surface. The air ship is like a submarine--the dirigible balloon of the sea--and perhaps rather more safe. An ordinary ship is only partially immersed; the resistance of the fluid medium is exerted over a portion only of its head end: but the submarine or the flying machine is wholly exposed to this resistance. The submarine is subjected to ocean currents of a very few miles per hour, at most; the currents to which the flying machine may be exposed exceed a mile a minute. Put a submarine in the Whirlpool Rapids at Niagara and you will have possible air ship conditions. A marine vessel may _tack_, _i.e._, may sail partially against the wind that propels it, by skillful utilization of the resistance to sidewise movement of the ship through the water: but the flying machine is wholly immersed in a single fluid, and a head wind is nothing else than a head wind, producing an absolute subtraction from the proper speed of the vessel. [Illustration: HOW A BOAT TACKS The wind always exerts a pressure, perpendicular to the sail, which tends to drift the boat sidewise (R) and also to propel it forward (L). Sidewise movement is resisted by the hull. An air ship cannot tack because there is no such resistance to drift.] Aerial navigation is thus a new art, particularly when heavier-than-air machines are used. We have no heavier-than-water _ships_. The flying machine must work out its own salvation. SOARING FLIGHT BY MAN Flying machines have been classified as follows:-- Lighter than Air Fixed balloon, Drifting balloon, Sailing balloon, Dirigible balloon rigid (Zeppelin), ballonetted. Heavier than Air Orthopter, Helicopter, Aeroplane monoplane, multiplane. We will fall in with the present current of popular interest and consider the aeroplane--that mechanical grasshopper--first. What Holds It Up? [Illustration: OCTAVE CHANUTE (DIED 1910)] To the researches of Chanute and Langley must be ascribed much of American progress in aviation. When a flat surface like the side of a house is exposed to the breeze, the velocity of the wind exerts a force or pressure directly against the surface. This principle is taken into account in the design of buildings, bridges, and other structures. The pressure exerted per square foot of surface is equal (approximately) to the square of the wind velocity in miles per hour, divided by 300. Thus, if the wind velocity is thirty miles, the pressure against a house wall on which it acts directly is 30 × 30 ÷ 300 = 3 pounds per square foot: if the wind velocity is sixty miles, the pressure is 60 × 60 ÷ 300 = 12 pounds: if the velocity is ninety miles, the pressure is 90 × 90 ÷ 300 = 27 pounds, and so on. [Illustration: PRESSURE OF THE WIND] If the wind blows obliquely toward the surface, instead of directly, the pressure at any given velocity is reduced, but may still be considerable. Thus, in the sketch, let _ab_ represent a wall, toward which we are looking downward, and let the arrow _V_ represent the direction of the wind. The air particles will follow some such paths as those indicated, being deflected so as to finally escape around the ends of the wall. The result is that a pressure is produced which may be considered to act along the dotted line _P_, perpendicular to the wall. This is the invariable law: that no matter how oblique the surface may be, with reference to the direction of the wind, there is always a pressure produced against the surface by the wind, and this pressure always acts _in a direction perpendicular to the surface_. The amount of pressure will depend upon the wind velocity and the obliquity or inclination of the surface (_ab_) with the wind (_V_). Now let us consider a kite--the "immediate ancestor" of the aeroplane. The surface _ab_ is that of the kite itself, held by its string _cd_. We are standing at one side and looking at the _edge_ of the kite. The wind is moving horizontally against the face of the kite, and produces a pressure _P_ directly against the latter. The pressure tends both to move it toward the left and to lift it. If the tendency to move toward the left be overcome by the string, then the tendency toward lifting may be offset--and in practice _is_ offset--by the weight of the kite and tail. [Illustration: FORCES ACTING ON A KITE] We may represent the two tendencies to movement produced by the force _P_, by drawing additional dotted lines, one horizontally to the left (_R_) and the other vertically (_L_); and it is known that if we let the length of the line _P_ represent to some convenient scale the amount of direct pressure, then the lengths of _R_ and _L_ will also represent to the same scale the amounts of horizontal and vertical force due to the pressure. If the weight of kite and tail exceeds the vertical force _L_, the kite will descend: if these weights are less than that force, the kite will ascend. If they are precisely equal to it, the kite will neither ascend nor descend. The ratio of _L_ to _R_ is determined by the slope of _P_; and this is fixed by the slope of _ab_; so that we have the most important conclusion: _not only does the amount of direct pressure (P) depend upon the obliquity of the surface with the breeze (as has already been shown), but the relation of vertical force (which sustains the kite) to horizontal force also depends on the same obliquity_. For example, if the kite were flying almost directly above the boy who held the string, so that _ab_ became almost horizontal, _P_ would be nearly vertical and _L_ would be much greater than _R_. On the other hand, if _ab_ were nearly vertical, the kite flying at low elevation, the string and the direct pressure would be nearly horizontal and _L_ would be much less than _R_. The force _L_ which lifts the kite seems to increase while _R_ decreases, as the kite ascends: but _L_ may not actually increase, because it depends upon the amount of direct pressure, _P_, as well as upon the direction of this pressure; and the amount of direct pressure steadily decreases during ascent, on account of the increasing obliquity of _ab_ with _V_. All of this is of course dependent on the assumption that the kite always has the same inclination to the string, and the described resolution of the forces, although answering for illustrative purposes, is technically incorrect. It seems to be the wind velocity, then, which holds up the kite: but in reality the string is just as necessary as the wind. If there is no string, and the wind blows the kite with it, the kite comes down, because the pressure is wholly due to a relative velocity as between kite and wind. The wind exerts a pressure against the rear of a railway train, if it happens to be blowing in that direction, and if we stood on the rear platform of a stationary train we should feel that pressure: but if the train is started up and caused to move at the same speed as the wind there would be no pressure whatever. One of the very first heavier-than-air flights ever recorded is said to have been made by a Japanese who dropped bombs from an immense man-carrying kite during the Satsuma rebellion of 1869. The kite as a flying machine has, however, two drawbacks: it needs the wind--it cannot fly in a calm--and it stands still. One early effort to improve on this situation was made in 1856, when a man was towed in a sort of kite which was hauled by a vehicle moving on the ground. In February of the present year, Lieut. John Rodgers, U.S.N., was lifted 400 feet from the deck of the cruiser _Pennsylvania_ by a train of eleven large kites, the vessel steaming at twelve knots against an eight-knot breeze. The aviator made observations and took photographs for about fifteen minutes, while suspended from a tail cable about 100 feet astern. In the absence of a sufficient natural breeze, an artificial wind was thus produced by the motion imparted to the kite; and the device permitted of reaching some destination. The next step was obviously to get rid of the tractive vehicle and tow rope by carrying propelling machinery on the kite. This had been accomplished by Langley in 1896, who flew a thirty-pound model nearly a mile, using a steam engine for power. The gasoline engine, first employed by Santos-Dumont (in a dirigible balloon) in 1901, has made possible the present day _aeroplane_. [Illustration: SUSTAINING FORCE IN THE AEROPLANE] What "keeps it up", in the case of this device, is likewise its velocity. Looking from the side, _ab_ is the sail of the aeroplane, which is moving toward the right at such speed as to produce the equivalent of an air velocity _V_ to the left. This velocity causes the direct pressure _P_, equivalent to a lifting force _L_ and a retarding force _R_. The latter is the force which must be overcome by the motor: the former must suffice to overcome the whole weight of the apparatus. Travel in an aeroplane is like skating rapidly over very thin ice: the air literally "doesn't have time to get away from underneath." [Illustration: DIRECT, LIFTING, AND RESISTING FORCES If the pressure is 10 lbs. when the wind blows directly toward the surface (at an angle of 90 degrees), then the forces for other angles of direction are as shown on the diagram. The _amounts_ of all forces depend upon the wind velocity: that assumed in drawing the diagram was about 55 miles per hour. But the _relations_ of the forces are the same for the various angles, no matter what the velocity.] If we designate the angle made by the wings (_ab_) with the horizontal (_V_) as _B_, then _P_ increases as _B_ increases, while (as has been stated) the ratio of _L_ to _R_ decreases. When the angle _B_ is a right angle, the wings being in the position _a´b´_, _P_ has its maximum value for direct wind--1/300 of the square of the velocity, in pounds per square foot; but _L_ is zero and _R_ is equal to _P_. The plane would have no lifting power. When the angle _B_ becomes zero, position _a´´b´´_, wings being horizontal, _P_ becomes zero and (so far as we can now judge) the plane has neither lifting power nor retarding force. At some intermediate position, like _ab_, there will be appreciable lifting and retarding forces. The chart shows the approximate lifting force, in pounds per square foot, for various angles. This force becomes a maximum at an angle of 45° (half a right angle). We are not yet prepared to consider why in all actual aeroplanes the angle of inclination is much less than this. The reason will be shown presently. At this stage of the discussion we may note that the lifting power per square foot of sail area varies with the square of the velocity, _and_ the angle of inclination. The total lifting power of the whole plane will also vary with its area. As we do not wish this whole lifting power to be consumed in overcoming the dead weight of the machine itself, we must keep the parts light, and in particular must use for the wings a fabric of light weight per unit of surface. These fabrics are frequently the same as those used for the envelopes of balloons. Since the total supporting power varies both with the sail area and with the velocity, we may attain a given capacity either by employing large sails or by using high speed. The size of sails for a given machine varies inversely as the square of the speed. The original Wright machine had 500 square feet of wings and a speed of forty miles per hour. At eighty miles per hour the necessary sail area for this machine would be only 125 square feet; and at 160 miles per hour it would be only 31-1/4 square feet: while if we attempted to run the machine at ten miles per hour we should need a sail area of 8000 square feet. This explains why the aeroplane cannot go slowly. It would seem as if when two or more superposed sails were used, as in biplanes, the full effect of the air would not be realized, one sail becalming the other. Experiments have shown this to be the case; but there is no great reduction in lifting power unless the distance apart is considerably less than the width of the planes. In all present aeroplanes the sails are concaved on the under side. This serves to keep the air from escaping from underneath as rapidly as it otherwise would, and increases the lifting power from one-fourth to one-half over that given by our 1/300 rule: the divisor becoming roughly about 230 instead of 300. [Illustration: SHAPES OF PLANES] Why are the wings placed crosswise of the machine, when the other arrangement--the greatest dimension in the line of flight--would seem to be stronger? This is also done in order to "keep the air from escaping from underneath." The sketch shows how much less easily the air will get away from below a wing of the bird-like spread-out form than from one relatively long and narrow but of the same area. A sustaining force of two pounds per square foot of area has been common in ordinary aeroplanes and is perhaps comparable with the results of bird studies: but this figure is steadily increasing as velocities increase. Why so Many Sails? Thus far a single wing or pair of wings would seem to fully answer for practicable flight: yet every actual aeroplane has several small wings at various points. The necessity for one of these had already been discovered in the kite, which is built with a balancing tail. In the sketch on page 18 it appears that the particles of air which are near the upper edge of the surface are more obstructed in their effort to get around and past than those near the lower edge. They have to turn almost completely about, while the others are merely deflected. This means that on the whole the upper air particles will exert more pressure than the lower particles and that the "center of pressure" (the point where the entire force of the wind may be assumed to act) will be, not at the center of the surface, but at a point some distance _above_ this center. This action is described as the "displacement of the center of pressure." It is known that the displacement is greatest for least inclinations of surface (as might be surmised from the sketch already referred to), and that it is always proportional to the dimension of the surface in the direction of movement; _i.e._, to the length of the line _ab_. [Illustration: BALANCING SAIL] If the weight _W_ of the aeroplane acts downward at the center of the wing (at _o_ in the accompanying sketch), while the direct pressure _P_ acts at some point _c_ farther along toward the upper edge of the wing, the two forces _W_ and _P_ tend to revolve the whole wing in the direction indicated by the curved arrow. This rotation, in an aeroplane, is resisted by the use of a tail plane or planes, such as _mn_. The velocity produces a direct pressure _P´_ on the tail plane, which opposes, like a lever, any rotation due to the action of _P_. It may be considered a matter of rather nice calculation to get the area and location of the tail plane just right: but we must remember that the amount of pressure _P´_ can be greatly varied by changing the inclination of the surface _mn_. This change of inclination is effected by the operator, who has access to wires which are attached to the pivoted tail plane. It is of course permissible to place the tail plane _in front_ of the main planes--as in the original Wright machine illustrated: but in this case, with the relative positions of _W_ and _P_ already shown, the forward edge of the tail plane would have to be depressed instead of elevated. The illustration shows the tail built as a biplane, just as are the principal wings (page 141). Suppose the machine to be started with the tail plane in a horizontal position. As its speed increases, it rises and at the same time (if the weight is suspended from the center of the main planes) tilts backward. The tilting can be stopped by swinging the tail plane on its pivot so as to oppose the rotative tendency. If this control is not carried too far, the main planes will be allowed to maintain some of their excessive inclination and ascent will continue. When the desired altitude has been attained, the inclination of the main planes will, by further swinging of the tail plane, be reduced to the normal amount, at which the supporting power is precisely equal to the load; and the machine will be in vertical equilibrium: an equilibrium which demands at every moment, however, the attention of the operator. In many machines, ascent and tilting are separately controlled by using two sets of transverse planes, one set placed forward, and the other set aft, of the main planes. In any case, quick ascent can be produced only by an increase in the lifting force _L_ (see sketch, page 24) of the main planes: and this force is increased by enlarging the angle of inclination of the main planes, that is, by a controlled and partial tilting. The forward transverse wing which produces this tilting is therefore called the _elevating rudder_ or elevating plane. The rear transverse plane which checks the tilting and steadies the machine is often described as the _stabilizing plane_. _Descent_ is of course produced by _decreasing_ the angle of inclination of the main planes. [Illustration: ROE'S TRIPLANE AT WEMBLEY (From Brewer's _Art of Aviation_)] Steering If we need extra sails for stability and ascent or descent, we need them also for changes of horizontal direction. Let _ab_ be the top view of the main plane of a machine, following the course _xy_. At _rs_ is a vertical plane called the _steering rudder_. This is pivoted, and controlled by the operator by means of the wires _t_, _u_. Let the rudder be suddenly shifted to the position _r´s´_. It will then be subjected to a pressure _P´_ which will swing the whole machine into the new position shown by the dotted lines, its course becoming _x´y´_. The steering rudder may of course be double, forming a vertical biplane, as in the Wright machine shown below. [Illustration: ACTION OF THE STEERING RUDDER] Successful steering necessitates lateral resistance to drift, _i.e._, a fulcrum. This is provided, to some extent, by the stays and frame of the machine; and in a much more ample way by the vertical planes of the original Voisin cellular biplane. A recent Wright machine had vertical planes forward probably intended for this purpose. [Illustration: RECENT TYPE OF WRIGHT BIPLANE] It now begins to appear that the aviator has a great many things to look after. There are many more things requiring his attention than have yet been suggested. No one has any business to attempt flying unless he is superlatively cool-headed and has the happy faculty of instinctively doing the right thing in an emergency. Give a chauffeur a high power automobile running at maximum speed on a rough and unfamiliar road, and you have some conception of the position of the operator of an aeroplane. It is perhaps not too much to say that to make the two positions fairly comparable we should _blindfold_ the chauffeur. Broadly speaking, designers may be classed in one of two groups--those who, like the Wrights, believe in training the aviator so as to qualify him to properly handle his complicated machine; and those who aim to simplify the whole question of control so that to acquire the necessary ability will not be impossible for the average man. If aviation is to become a popular sport, the latter ideal must prevail. The machines must be more automatic and the aviator must have time to enjoy the scenery. In France, where amateur aviation is of some importance, progress has already been made in this direction. The universal steering head, for example, which not only revolves like that of an automobile, but is hinged to permit of additional movements, provides for simultaneous control of the steering rudder and the main plane warping, while scarcely demanding the conscious thought of the operator. TURNING CORNERS A year elapsed after the first successful flight at Kitty Hawk before the aviator became able to describe a circle in the air. A later date, 1907, is recorded for the first European half-circular flight: and the first complete circuit, on the other side of the water, was made a year after that; by both biplane and monoplane. It was in the same year that Louis Blériot made the pioneer cross-country trip of twenty-one miles, stopping at will _en route_ and returning to his starting point. What Happens When Making a Turn [Illustration: CIRCULAR FLIGHT] We are looking downward on an aeroplane _ab_ which has been moving along the straight path _cd_. At _d_ it begins to describe the circle _de_, the radius of which is _od_, around the center _o_. The outer portion of the plane, at the edge _b_, must then move faster than the inner edge _a_. We have seen that the direct air pressure on the plane is proportional to the square of the velocity. The direct pressure _P_ (see sketch on page 22) will then be greater at the outer than at the inner limb; the lifting force _L_ will also be greater and the outer limb will tend to rise, so that the plane (viewed from the rear) will take the inclined position shown in the lower view: and this inclination will increase as long as the outer limb travels faster than the inner limb; that is, as long as the orbit continues to be curved. Very soon, then, the plane will be completely tipped over. Necessarily, the two velocities have the ratio _om_:_om´_; the respective lifting forces must then be proportional to the squares of these distances. The difference of lifting forces, and the tendency to overturn, will be more important as the distances most greatly differ: which is the case when the distance _om_ is small as compared with _mm´_. The shorter the radius of curvature, the more dangerous, for a given machine, is a circling flight: and in rounding a curve of given radius the most danger is attached to the machine of greatest spread of wing. Lateral Stability This particular difficulty has considerably delayed the development of the aeroplane. It may, however, be overcome by very simple methods--simple, at least as far as their mechanical features are concerned. If the outer limb of the plane is tilted upward, it is because the wind pressure is greater there. The wind pressure is greater because the velocity is greater. We have only to increase the wind pressure at the inner limb, in order to restore equilibrium. This cannot be done by adjusting the velocity, because the velocity is fixed by the curvature of path required: but the total wind pressure depends upon the _sail area_ as well as the velocity; so that by increasing the surface at the inner limb we may equalize the value of _L_, the lifting force, at the two ends of the plane. This increase of surface must be a temporary affair, to be discontinued when moving along a straight course. [Illustration: THE AILERON] Let us stand in the rear of an aeroplane, the main wing of which is represented by _ab_. Let the small fan-shaped wings _c_ and _d_ be attached near the ends, and let the control wires, _e_, _f_, passing to the operator at _g_, be employed to close and unclasp the fans. If these fans are given a forward inclination at the top, as indicated in the end view, they will when spread out exert an extra lifting force. A fan will be placed at each end. They will be ordinarily folded up: but when rounding a curve the aviator will open the fan on the inner or more slowly moving limb of the main plane. This represents one of the first forms of the _aileron_ or wing-tip for lateral control. The more common present form of aileron is that shown in the lower sketch, at _s_ and _t_. The method of control is the same. [Illustration: WING TIPPING] The cellular Voisin biplanes illustrate an attempt at self-sufficing control, without the interposition of the aviator. Between the upper and lower sails of the machine there were fore and aft vertical partitions. The idea was that when the machine started to revolve, the velocity of rotation would produce a pressure against these partitions which would obstruct the tipping. But rotation may take place slowly, so as to produce an insufficient pressure for control, and yet be amply sufficient to wreck the apparatus. The use of extra vertical rudder planes, hinged on a horizontal longitudinal axis, is open to the same objection. Wing Warping In some monoplanes with the inverted _V_ wing arrangement, a dipping of one wing answers, so to speak, to increase its concavity and thus to augment the lifting force on that side. The sketch shows the normal and distorted arrangement of wings: the inner limb being the one bent down in rounding a curve. An equivalent plan was to change the angle of inclination of one-half the sail by swinging it about a horizontal pivot at the center or at the rear edge: some machines have been built with sails divided in the center. The obvious objection to both of these plans is that too much mechanism is necessary in order to distort what amounts to nearly half the whole machine. They remind one of Charles Lamb's story of the discovery of roast pig. [Illustration: WING WARPING] The distinctive feature of the Wright machines lies in the warping or distorting of the _ends only_ of the main planes. This is made possible, not by hinging the wings in halves, but by the flexibility of the framework, which is sufficiently pliable to permit of a considerable bending without danger. The operator, by pulling on a stout wire linkage, may tip up (or down) the corners _cc´_ of the sails at one limb, thus decreasing or increasing the effective surface acted on by the wind, as the case may require. The only objection is that the scheme provides one more thing for the aviator to think about and manipulate. Automatic Control Let us consider again the condition of things when rounding a curve, as in the sketch on page 32. As long as the machine is moving forward in a straight line, the operator sits upright. When it begins to tip, he will unconsciously tip himself the other way, as represented by the line _xy_ in the rear view. Any bicyclist will recognize this as plausible. Why not take advantage of this involuntary movement to provide a stabilizing force? If operating wires are attached to the aviator's belt and from thence connected with ailerons or wing-warping devices, then by a proper proportioning of levers and surfaces to the probable swaying of the man, the control may become automatic. The idea is not new; it has even been made the subject of a patent. The Gyroscope [Illustration: THE GYROSCOPE] This device for automatic control is being steadily developed and may ultimately supersede all others. It uses the inertia of a fast-moving fly wheel for control, in a manner not unlike that contemplated in proposed methods of automatic balancing by the action of a suspended pendulum. Every one has seen the toy gyroscope and perhaps has wondered at its mysterious ways. The mathematical analysis of its action fills volumes: but some idea of what it does, and why, may perhaps be gathered at the expense of a very small amount of careful attention. The wheel _acbd_, a thin disc, is spinning rapidly about the axle _o_. In the side view, _ab_ shows the edge of the wheel, and _oo´_ the axle. This axle is not fixed, but may be conceived as held in some one's fingers. Now suppose the right-hand end of the axle (_o´_) to be suddenly moved toward us (away from the paper) and the left-hand (_o_) to be moved away. The wheel will now appear in both views as an ellipse, and it has been so represented, as _afbe_. Now, any particle, like _x_, on the rim of the wheel, will have been regularly moving in the circular orbit _cb_. The tendency of any body in motion is to move indefinitely in a straight line. The cohesion of the metal of the disc prevents the particle _x_ from flying off at a straight line tangent, _xy_, and it is constrained, therefore, to move in a circular orbit. Unless some additional constraint is imposed, it will at least remain in this orbit and will try to remain in its plane of rotation. When the disc is tipped, the plane of rotation is changed, and the particle is required, instead of (so to speak) remaining in the plane of the paper--in the side view--to approach and pass through that plane at _b_ and afterward to continue receding from us. Under ordinary circumstances, this is just what it would do: but if, as in the gyroscope, the axle _oo´_ is perfectly free to move in any direction, the particle _x_ will refuse to change its direction of rotation. Its position has been shifted: it no longer lies in the plane of the paper: but it will at least persist in rotating in a parallel plane: and this persistence forces the revolving disc to swing into the new position indicated by the curve _hg_, the axis being tipped into the position _pq_. The whole effect of all particles like _x_ in the entire wheel will be found to produce precisely this condition of things: if we undertake to change the plane of rotation by shifting the axle in a horizontal plane, the device itself will (if not prevented) make a further change in the plane of rotation by shifting the axle in a vertical plane. A revolving disc mounted on the gyroscopic framework therefore resists influences tending to change its plane of rotation. If the device is placed on a steamship, so that when the vessel rolls a change of rotative plane is produced, the action of the gyroscope will resist the rolling tendency of the vessel. All that is necessary is to have the wheel revolving in a fore and aft plane on the center line of the vessel, the axle being transverse and firmly attached to the vessel itself. A small amount of power (consumed in revolving the wheel) gives a marked steadying effect. The same location and arrangement on an aeroplane will suffice to overcome tendencies to transverse rotation when rounding curves. The device itself is automatic, and requires no attention, but it does unfortunately require power to drive it and it adds some weight. The gyroscope is being tested at the present time on some of the aeroplanes at the temporary army camps near San Antonio, Texas. Wind Gusts This feature of aeronautics is particularly important, because any device which will give automatic stability when turning corners will go far toward making aviation a safe amusement. Inequalities of velocity exist not only on curves, but also when the wind is blowing at anything but uniform velocity across the whole front of the machine. The slightest "flaw" in the wind means an at least temporary variation in lifting force of the two arms. Here is a pregnant source of danger, and one which cannot be left for the aviator to meet by conscious thought and action. It is this, then, that blindfolds him: he cannot see the wind conditions in advance. The conditions are upon him, and may have done their destructive work, before he can prepare to control them. We must now study what these conditions are and what their influence may be on various forms of aerial navigation: after which, a return to our present subject will be possible. AIR AND THE WIND The air that surrounds us weighs about one-thirteenth of a pound per cubic foot and exerts a pressure, at sea level, of nearly fifteen pounds per square inch. Its temperature varies from 30° below to 100° above the Fahrenheit zero. The pressure of the air decreases about one-half pound for each thousand feet of altitude; at the top of Mt. Blanc it would be, therefore, only about six pounds per square inch. The temperature also decreases with the altitude. The weight of a cubic foot, or _density_, which, as has been stated, is one-thirteenth of a pound ordinarily, varies with the pressure and with the temperature. The variation with pressure may be described by saying that the _quotient_ of the pressure by the density is constant: one varies in the same ratio as the other. Thus, at the top of Mt. Blanc (if the temperature were the same as at sea level), the density of air would be about 6/15 × 1/13 = 2/65: less than half what it is at sea level. As to temperature, if we call our Fahrenheit zero 460°, and correspondingly describe other temperatures--for instance, say that water boils at 672°--then (pressure being unchanged) the _product_ of the density and the temperature is constant. If the density at sea level and zero temperature is one-thirteenth pound, then that at sea level and 460° Fahrenheit would be (0 + 460)/(460 + 460) × 1/13 = 1/26. These relations are particularly important in the design of all balloons, and in computations relating to aeroplane flight at high altitudes. We shall be prepared to appreciate some of their applications presently. Generally speaking, the atmosphere is always in motion, and moving air is called wind. Our meteorologists first studied winds near the surface of the ground: it is only of late years that high altitude measurements have been considered practically desirable. Now, records are obtained by the aid of kites up to a height of nearly four miles: estimates of cloud movements have given data on wind velocities at heights above six miles: and much greater heights have been obtained by free balloons equipped with instruments for recording temperatures, pressures, altitude, time, and other data. When the Eiffel Tower was completed, it was found that the average wind velocity at its summit was about four times that at the base. Since that time, much attention has been given to the contrasting conditions of surface and upper breezes as to direction and velocity. Air is easily impeded in its movement, and the well-known uncertainties of the weather are closely related to local variations in atmospheric pressure and temperature. When near the surface of the ground, impingement against irregularities therein--hills, cliffs, and buildings--makes the atmospheric currents turbulent and irregular. Where there are no surface irregularities, as on a smooth plain or over water, the friction of the air particles passing over the surface still results in a stratification of velocities. Even on a mountain top, the direction and speed of the wind are less steady than in the open where measured by a captive balloon. The stronger the wind, the greater, relatively, is the irregularity produced by surface conditions. Further, the earth's surface and its features form a vast sponge for sun heat, which they transfer in turn to the air in an irregular way, producing those convectional currents peculiar to low altitudes, the upper limit of which is marked by the elevation of the cumulus clouds. Near the surface, therefore, wind velocities are lowest in the early morning, rising to a maximum in the afternoon. [Illustration: DIURNAL TEMPERATURES AT DIFFERENT HEIGHTS (From Rotch's _The Conquest of the Air_)] Every locality has its so-called "prevailing winds." Considering the compass as having eight points, one of those points may describe as many as 40% of all the winds at a given place. The direction of prevalence varies with the season. The range of wind velocities is also a matter of local peculiarity. In Paris, the wind speed exceeds thirty-four miles per hour on only sixty-eight days in the average year, and exceeds fifty-four miles on only fifteen days. Observations at Boston show that the velocity of the wind exceeds twenty miles per hour on half the days in winter and on only one-sixth the days in summer. Our largest present dirigible balloons have independent speeds of about thirty-four miles per hour and are therefore available (at some degree of effectiveness) for nearly ten months of the year, in the vicinity of Paris. In a region of low wind velocities--like western Washington, in this country--they would be available a much greater proportion of the time. To make the dirigible able to at least move nearly every day in the average year--in Paris--it must be given a speed of about fifty-five miles per hour. Figures as to wind velocity mean little to one unaccustomed to using them. A five-mile breeze is just "pleasant." Twelve miles means a brisk gale. Thirty miles is a high wind: fifty miles a serious storm (these are the winds the aviator constantly meets): one hundred miles is perhaps about the maximum hurricane velocity. As we ascend from the surface of the earth, the wind velocity steadily increases; and the excess velocity of winter winds over summer winds is as steadily augmented. Thus, Professor Rotch found the following variations: Altitude in Feet Annual Average Wind Velocity, Feet per Second 656 23.15 1,800 32.10 3,280 35. 8,190 41. 11,440 50.8 17,680 81.7 20,970 89. 31,100 117.5 Average Wind Velocities, Altitude in Feet Feet per Second Summer Winter 656 to 3,280 24.55 28.80 3,280 to 9,810 26.85 48.17 9,810 to 16,400 34.65 71.00 16,400 to 22,950 62.60 161.5 22,950 to 29,500 77.00 177.0 [Illustration: DIURNAL TEMPERATURES AT DIFFERENT HEIGHTS] These results are shown in a more striking way by the chart. At a five or six mile height, double-barreled hurricanes at speeds exceeding 200 miles per hour are not merely possible; they are part of the regular order of things, during the winter months. The winds of the upper air, though vastly more powerful, are far less irregular than those near the surface: and the directions of prevailing winds are changed. If 50% of the winds, at a given location on the surface, are from the southwest, then at as moderate an elevation as even 1000 feet, the prevailing direction will cease to be from southwest; it may become from west-southwest; and the proportion of total winds coming from this direction will not be 50%. These factors are represented in meteorological papers by what is known as the _wind rose_. From the samples shown, we may note that 40% of the surface winds at Mount Weather are from the northwest; while at some elevation not stated the most prevalent of the winds (22% of the total) are westerly. The direction of prevalence has changed through one-eighth of the possible circle, and in a _counter-clockwise_ direction. This is contrary to the usual variation described by the so-called Broun's Law, which asserts that as we ascend the direction of prevalence rotates around the circle like the hands of a watch; being, say, from northwest at the surface, from north at some elevation, from northeast at a still higher elevation, and so on. At a great height, the change in direction may become total: that is, the high altitude winds blow in the exactly opposite direction to that of the surface winds. In the temperate regions, most of the high altitude winds are from the west: in the tropics, the surface winds blow _toward_ the west and toward the equator; being northeasterly in the northern hemisphere and southeasterly in the southern: and there are undoubtedly equally prevalent high-altitude counter-trades. [Illustration: THE WIND ROSE FOR MOUNT WEATHER, VA. (From the _Bulletin_ of the Mount Weather Observatory, II, 6)] The best flying height for an aeroplane over a flat field out in the country is perhaps quite low--200 or 300 feet: but for cross-country trips, where hills, rivers, and buildings disturb the air currents, a much higher elevation is necessary; perhaps 2000 or 3000 feet, but in no case more than a mile. The same altitude is suitable for dirigible balloons. At these elevations we have the conditions of reasonable warmth, dryness, and moderate wind velocities. Sailing Balloons In classifying air craft, the sailing balloon was mentioned as a type intermediate between the drifting balloon and the dirigible. No such type has before been recognized: but it may prove to have its field, just as the sailing vessel on the sea has bridged the gap between the raft and the steamship. It is true that tacking is impossible, so that our sailing balloons must always run before the wind: but they possess this great advantage over marine sailing craft, that by varying their altitude they may always be able to find a favorable wind. This implies adequate altitude control, which is one of the problems not yet solved for lighter-than-air flying machines: but when it has been solved we shall go far toward attaining a dirigible balloon without motor or propeller; a true sailing craft. [Illustration: DIAGRAM OF PARTS OF A DRIFTING BALLOON] This means more study and careful utilization of stratified atmospheric currents. Professor Rotch suggests the utilization of the upper westerly wind drift across the American continent and the Atlantic Ocean, which would carry a balloon from San Francisco to southern Europe at a speed of about fifty feet per second--thirty-four miles per hour. Then by transporting the balloon to northern Africa, the northeast surface trade wind would drive it back to the West Indies at twenty-five miles per hour. This without any motive power: and since present day dirigibles are all short of motive power for complete dirigibility, we must either make them much more powerful or else adopt the sailing principle, which will permit of actually decreasing present sizes of motors, or even possibly of omitting them altogether. Our next study is, then, logically, one of altitude control in balloons. [Illustration: GLIDDEN AND STEVENS GETTING AWAY IN THE "BOSTON" (Leo Stevens, N.Y.)] Field and Speed [Illustration: RELATIVE AND ABSOLUTE BALLOON VELOCITIES] [Illustration: FIELD AND SPEED] An _aerostat_ (non-dirigible balloon), unless anchored, drifts at the speed of the wind. To the occupants, it seems to stand still, while the surface of the earth below appears to move in a direction opposite to that of the wind. In the sketch, if the independent velocity of a _dirigible_ balloon be _PB_, the wind velocity _PV_, then the actual course pursued is _PR_, although the balloon always points in the direction _PB_, as shown at 1 and 2. If the speed of the wind exceed that of the balloon, there will be some directions in which the latter cannot progress. Thus, let _PV_ be the wind velocity and _TV_ the independent speed of the balloon. The tangents _PX_, _PX´_, include the whole "field of action" possible. The wind direction may change during flight, so that the initial objective point may become unattainable, or an initially unattainable point may be brought within the field. The present need is to increase independent speeds from thirty or forty to fifty or sixty miles per hour, so that the balloon will be truly dirigible (even if at low effectiveness) during practically the whole year. [Illustration: INFLUENCE OF WIND ON POSSIBLE COURSE] Suppose a dirigible to start on a trip from New York to Albany, 150 miles away. Let the wind be a twenty-five mile breeze from the southwest. The wind alone tends to carry the balloon from New York to the point _d_ in four hours. If the balloon meanwhile be headed due west, it would need an independent velocity of its own having the same ratio to that of the wind as that of _de_ to _fd_, or about seventeen and one-half miles per hour. Suppose its independent speed to be only twelve and one-half miles; then after four hours it will be at the position _b_, assuming it to have been continually headed due west, as indicated at _a_. It will have traveled northward the distance _fe_, apparently about sixty-nine miles. [Illustration: COUNT ZEPPELIN] After this four hours of flight, the wind suddenly changes to south-southwest. It now tends to carry the balloon to _g_ in the next four hours. Meanwhile the balloon, heading west, overcomes the easterly drift, and the balloon actually lands at _c_. Unless there is some further favorable shift of the wind it cannot reach Albany. If, during the second four hours, its independent speed could have been increased to about fifteen and a half miles it would have just made it. The actual course has been _fbc_: a drifting balloon would have followed the course _fdh_, _dh_ being a course parallel to _bg_. GAS AND BALLAST A cubical block of wood measuring twelve inches on a side floats on water because it is lighter than water; it weighs, if yellow pine, thirty-eight pounds, whereas the same volume of water weighs about sixty-two pounds. Any substance weighing more than sixty-two pounds to the cubic foot would sink in water. [Illustration: BUOYANT POWER OF WOOD] If our block of wood be drilled, and _lead_ poured in the hole, the total size of wood-and-lead block being kept constantly at one cubic foot, the block will sink as soon as its whole weight exceeds sixty-two pounds. Ignoring the wood removed by boring (as, compared with the lead which replaces it, an insignificant amount), the weight of lead plugged in may reach twenty-four pounds before the block will sink. This figure, twenty-four pounds, the difference between sixty-two and thirty-eight pounds, then represents the maximum buoyant power of a cubic foot of wood in water. It is the difference between the weight of the wood block and the weight of the water it displaces. If any weight less than this is added to that of the wood, the block will float, projecting above the water's surface more or less, according to the amount of weight buoyed up. It will not rise entirely from the water, because to do this it would need to be lighter, not only than water, but than air. [Illustration: ONE CUBIC FOOT OF WOOD LOADED IN WATER] Buoyancy in Air There are _gases_, if not woods, lighter than air: among them, coal gas and hydrogen. A "bubble" of any of these gases, if isolated from the surrounding atmosphere, cannot sink but must rise. At the same pressure and temperature, hydrogen weighs about one-fifteenth as much as air; coal gas, about one-third as much. If a bubble of either of these gases be isolated in the atmosphere, it must continually rise, just as wood immersed in water will rise when liberated. But the wood will stop when it reaches the surface of the water, while there is no reason to suppose that the hydrogen or coal gas bubbles will ever stop. The hydrogen bubble can be made to remain stationary if it is weighted down with something of about fourteen times its own weight (thirteen and one-half times, accurately). Perhaps it would be better to say that it would still continue to rise slowly because that additional something would itself displace some additional air; but if the added weight is a solid body, its own buoyancy in air is negligible. [Illustration: BUOYANT POWER OF HYDROGEN] Our first principle is, then, that at the same pressure and temperature, any gas lighter than air, if properly confined, will exert a net lifting power of (_n_-1) times its own weight, where _n_ is the ratio of weights of air and gas per cubic foot. [Illustration: LEBAUDY'S "JAUNE"] If the pressures and temperatures are different, this principle is modified. In a balloon, the gas is under a pressure slightly in excess of that of the external atmosphere: this decreases its lifting power, because the weight of a given volume of gas is greater as the pressure to which it is subjected is increased. The weight of a given volume we have called the _density_: and, as has been stated, if the temperature be unchanged, the density varies directly as the pressure. The pressure in a balloon is only about 1% greater than that of the atmosphere at sea level, so that this factor has only a slight influence on the lifting power. That it leads to certain difficulties in economy of gas will, however, soon be seen. The temperature of the gas in a balloon, one might think, would naturally be the same as that of the air outside: but the surface of the balloon envelope has an absorbing capacity for heat, and on a bright sunny day the gas may be considerably warmed thereby. This action increases the lifting power, since increase of temperature (the pressure remaining fixed) decreases the density of a gas. To avoid this possibly objectionable increase in lifting power, balloons are sometimes painted with a non-absorbent color. One of the first Lebaudy balloons received a popular nickname in Paris on account of the yellow hue of its envelope. Suppose we wish a balloon to carry a total weight, including that of the envelope itself, of a ton. If of hydrogen, it will have to contain one fifteenth of this weight or about 133 pounds of that gas, occupying a space of about 23,000 cubic feet. If coal gas is used, the size of the balloon would have to be much greater. If hot air is used--as has sometimes been the case--let us assume the temperature of the air inside the envelope such that the density is just half that of the outside air. This would require a temperature probably about 500°. The air needed would be just a ton, and the balloon would be of about 52,000 cubic feet. It would soon lose its lifting power as the air cooled; and such a balloon would be useful only for short flights. [Illustration: AIR BALLOON (Photo by Paul Thompson, N.Y.) Built by some Germans in the backwoods of South Africa] The 23,000 cubic foot hydrogen balloon, designed to carry a ton, would just answer to sustain the weight. If anchored at sea level, it would neither fall to the ground nor tug upward on its holding-down ropes. In order to ascend, something more is necessary. This "something more" might be some addition to the size and to the amount of hydrogen. Let us assume that we, instead, drop one hundred pounds of our load. Thus relieved of so much ballast, the balloon starts upward, under the net lifting force of one hundred pounds. It is easy to calculate how far it will go. It will not ascend indefinitely, because, as the altitude increases, the pressure (and consequently the density) of the external atmosphere decreases. At about a 2000-foot elevation, this decrease in density will have been sufficient to decrease the buoyant power of the hydrogen to about 1900 pounds, and the balloon will cease to rise, remaining at this level while it moves before the wind. There are several factors to complicate any calculations. Any expansion of the gas bag--stretching due to an increase in internal pressure--would be one; but the envelope fabrics do not stretch much; there is indeed a very good reason why they must not be allowed to stretch. The pressure in the gas bag is a factor. If there is no stretching of the bag, this pressure will vary directly with the temperature of the gas, and might easily become excessive when the sun shines on the envelope. A more serious matter is the increased difference between the internal pressure of the gas and the external pressure of the atmosphere at high altitudes. Atmospheric pressure decreases as we ascend. The difference between gas pressure and air pressure thus increases, and it is this difference of pressure which tends to burst the envelope. Suppose the difference of pressure at sea level to have been two-tenths of a pound. For a balloon of twenty feet diameter, this would give a stress on the fabric, per lineal inch, of twenty-four pounds. At an altitude of 2000 feet, the atmospheric pressure would decrease by one pound, the difference of pressures would become one and two-tenths pounds, and the stress on the fabric would be 144 pounds per lineal inch--an absolutely unpermissible strain. There is only one remedy: to allow some of the gas to escape through the safety valve; and this will decrease our altitude. Ascending and Descending To ascend, then, we must discard ballast: and we cannot ascend beyond a certain limit on account of the limit of allowable pressure on the envelope fabric. To again descend, we must discharge some of the gas which gives us lifting power. Every change of altitude thus involves a loss either of gas or of ballast. Our vertical field of control may then be represented by a series of oscillations of gradually decreasing magnitude until finally all power to ascend is gone. And even this situation, serious as it is, is made worse by the gradual but steady leakage of gas through the envelope fabric. Here, in a word, is the whole problem of altitude regulation. Air has no surface of equilibrium like water. Some device supplementary to ballast and the safety valve is absolutely necessary for practicable flight in any balloon not staked to the ground. A writer of romance has equipped his aeronautic heroes with a complete gas-generating plant so that all losses might be made up; and in addition, heating arrangements were provided so that when the gas supply had been partially expended its lifting power could be augmented by warming it so as to decrease its density below even the normal. There might be something to say in favor of this latter device, if used in connection with a collapsible gas envelope. Methods of mechanically varying the size of the balloon, so as by compressing the gas to cause descent and by giving it more room to increase its lifting power and produce ascent, have been at least suggested. The idea of a vacuum balloon, in which a rigid hollow shell would be exhausted of its contents by a continually working pump, may appear commendable. Such a balloon would have maximum lifting power for its size; but the weight of any rigid shell would be considerable, and the pressure tending to rupture it would be about 100 times that in ordinary gas balloons. It has been proposed to carry stored gas at high pressure (perhaps in the liquefied condition) as a supplementary method of prolonging the voyage while facilitating vertical movements: but hydrogen gas at a pressure of a ton to the square inch in steel cylinders would give an ultimate lifting power of only about one-tenth the weight of the cylinders which contain it. These cylinders might be regarded as somewhat better than ordinary ballast: but to throw them away, with their gas charge, as ballast, would seem too tragic. Liquefied gas might possibly appear rather more desirable, but would be altogether too expensive. [Illustration: SCREW PROPELLER FOR ALTITUDE CONTROL] If a screw propeller can be used on a steamship, a dirigible balloon, or an aeroplane to produce forward motion, there is no reason why it could not also be used to produce upward motion in any balloon; and the propeller with its operating machinery would be a substitute for twice its equivalent in ballast, since it could produce motion either upward or downward. Weight for weight, however, the propeller and engine give only (in one computed case) about half the lifting power of hydrogen. If we are to use the screw for ascent, we might well use a helicopter, heavier than air, rather than a balloon. The Ballonet The present standard method of improving altitude regulation involves the use of the ballonet, or compartment air bag, inside the main envelope. For stability and effective propulsion, it is important that the balloon preserve its shape, no matter how much gas be allowed to escape. Dirigible balloons are divided into two types, according to the method employed for maintaining the shape. In the Zeppelin type, a rigid internal metal framework supports the gas envelope. This forms a series of seventeen compartments, each isolated from the others. No matter what the pressure of gas, the shape of the balloon is unchanged. In the more common form of balloon, the internal air ballonet is empty, or nearly so, when the main envelope is full. As gas is vented from the latter, air is pumped into the former. This compresses the remaining gas and thus preserves the normal form of the balloon outline. [Illustration: BALLOON WITH BALLONETS] But the air ballonet does more than this. It provides an opportunity for keeping the balloon on a level keel, for by using a number of compartments the air can be circulated from one to another as the case may require, thus altering the distribution of weights. Besides this, if the pressure in the air ballonet be initially somewhat greater than that of the external atmosphere, a considerable ascent may be produced by merely venting this air ballonet. This involves no loss of gas; and when it is again desired to descend, air may be pumped into the ballonet. If any considerable amount of gas should be vented, to produce quick and rapid descent, the pumping of air into the ballonet maintains the shape of the balloon and also facilitates the descent. [Illustration: CONSTRUCTION OF THE ZEPPELIN BALLOON] The Equilibrator [Illustration: THE EQUILIBRATOR IN NEUTRAL POSITION] Suppose a timber block of one square foot area, ten feet long, weighing 380 pounds, to be suspended from the balloon in the ocean, and let mechanism be provided by which this block may be raised or lowered at pleasure. When completely immersed in water it exerts an upward pressure (lifting force) of 240 pounds, which may be used to supplement the lifting power of the balloon. If wholly withdrawn from the water, it pulls down the balloon with its weight of 380 pounds. It seems to be equivalent, therefore, to about 620 pounds of ballast. When immersed a little over six feet--the upper four feet being out of the water--it exerts neither lifting nor depressing effect. The amount of either may be perfectly adjusted between the limits stated by varying the immersion. In the Wellman-Vaniman equilibrator attached to the balloon _America_, which last year carried six men (and a cat) a thousand miles in three days over the Atlantic Ocean, a string of tanks partly filled with fuel was used in place of the timber block. As the tanks were emptied, the degree of control was increased; and this should apparently have given ideal results, equilibration being augmented as the gas supply was lost by leakage: but the unsailorlike disregard of conditions resulting from the strains transferred from a choppy sea to the delicate gas bag led to disaster, and it is doubtful whether this method of control can ever be made practicable. The _America's_ trip was largely one of a drifting rather than of a dirigible balloon. The equilibrator could be used only in flights over water in any case: and if we are to look to water for our buoyancy, why not look wholly to water and build a ship instead of a balloon? DIRIGIBLE BALLOONS AND OTHER KINDS Shapes [Illustration: HENRY GIFFARD'S DIRIGIBLE (The first with steam power)] The cylindrical Zeppelin balloon with approximately conical ends has already been shown (page 68). Those balloons in which the shape is maintained by internal pressure of air are usually _pisciform_, that is, fish-shaped. Studies have actually been made of the contour lines of various fishes and equivalent symmetrical forms derived, the outline of the balloon being formed by a pair of approximately parabolic curves. [Illustration: DIRIGIBLE OF DUPUY DE LOME (Man Power)] The first flight in a power driven balloon was made by Giffard in 1852. This balloon had an independent speed of about ten feet per second, but was without appliances for steering. A ballonetted balloon of 120,000 cubic feet capacity was directed by man power in 1872: eight men turned a screw thirty feet in diameter which gave a speed of about seven miles per hour. Electric motors and storage batteries were used for dirigible balloons in 1883-'84: in the latter year, Renard and Krebs built the first fish-shaped balloon. The first dirigible driven by an internal combustion motor was used by Santos-Dumont in 1901. [Illustration: TISSANDIER BROTHERS' DIRIGIBLE BALLOON (Electric Motor)] Dimensions The displacements of present dirigibles vary from 20,000 cubic feet (in the United States Signal Corps airship) up to 460,000 cubic feet (in the Zeppelin). The former balloon has a carrying capacity only about equivalent to that of a Wright biplane. While anchored or drifting balloons are usually spherical, all dirigibles are elongated, with a length of from four to eleven diameters. The Zeppelin represents an extreme elongation, the length being 450 feet and the diameter forty-two feet. At the other extreme, some of the English military dirigibles are thirty-one feet in diameter and only 112 feet long. Ballonet capacities may run up to one-fifth the gas volume. All present dirigibles have gasoline engines driving propellers from eight to twenty feet in diameter. The larger propellers are connected with the motors by gearing, and make from 250 to 700 turns per minute. The smaller propellers are direct connected and make about 1200 revolutions. Speeds are usually from fifteen to thirty miles per hour. [Illustration: THE BALDWIN Dirigible of the United States Signal Corps] The present-day elongated shape is the result of the effort to decrease the proportion of propulsion resistance due to the pressure of the air against the head of the balloon. This has led also to the pointed ends now universal; and to avoid eddy resistance about the rear it is just as important to point the stern as the bow. As far as head end resistance alone is concerned, the longer the balloon the better: but the friction of the air along the side of the envelope also produces resistance, so that the balloon must not be too much elongated. Excessive elongation also produces structural weakness. From the standpoint of stress on the fabric of the envelope, the greatest strain is that which tends to break the material along a longitudinal line, and this is true no matter what the length, as long as the seams are equally strong in both directions and the load is so suspended as not to produce excessive bending strain on the whole balloon. In the _Patrie_ (page 77), some distortion due to loading is apparent. The stress per lineal inch of fabric is obtained by multiplying the net pressure by half the diameter of the envelope (in inches). [Illustration: THE ZEPPELIN ENTERING ITS HANGAR ON LAKE CONSTANCE] Ample steering power (provided by vertical planes, as in heavier-than-air machines) is absolutely necessary in dirigibles: else the head could not be held up to the wind and the propelling machinery would become ineffective. Fabrics The material for the envelope and ballonets should be light, strong, unaffected by moisture or the atmosphere, non-cracking, non-stretching, and not acted upon by variations in temperature. The same specifications apply to the material for the wings of an aeroplane. In addition, for use in dirigible balloons, fabrics must be impermeable, resistent to chemical action of the gas, and not subject to spontaneous combustion. The materials used are vulcanized silk, gold beater's skin, Japanese silk and rubber, and cotton and rubber compositions. In many French balloons, a middle layer of rubber has layers of cotton on each side, the whole thickness being the two hundred and fiftieth part of an inch. In the _Patrie_, this was supplemented by an outside non-heat-absorbent layer of lead chromate and an inside coating of rubber, all rubber being vulcanized. The inner rubber layer was intended to protect the fabric against the destructive action of impurities in the gas. [Illustration: THE "PATRIE." DESTROYED BY A STORM] Fabrics are obtainable in various colors, painted, varnished, or wholly uncoated. The rubber and cotton mixtures are regularly woven in France and Germany for aeroplanes and balloons. The cars and machinery are frequently shielded by a fabricated wall. Weights of envelope materials range from one twenty-third to one-fourteenth pound per square foot, and breaking stresses from twenty-eight to one hundred and thirty pounds. Pressures (net) in the main envelope are from three-fifths to one and a quarter _ounces_ per square inch, those in the ballonets being somewhat less. The _Patrie_ of 1907 had an envelope guaranteed not to allow the leakage of more than half a cubic inch of hydrogen per square foot of surface per twenty-four hours. [Illustration: MANUFACTURING THE ENVELOPE OF A BALLOON] [Illustration: INSPECTING THE ENVELOPE OF ANDRÉE'S BALLOON "L'OERNEN"] The best method of cutting the fabric is to arrange for building up the envelope by a series of strips about the circumference, the seams being at the bottom. The two warps of the cloth should cross at an angle so as to localize a rip or tear. Bands of cloth are usually pasted over the seams, inside and out, with a rubber solution; this is to prevent leakage at the stitches. Framing In the _Zeppelin_, the rigid aluminum frame is braced every forty-five feet by transverse diametral rods which make the cross-sections resemble a bicycle wheel (page 68). This cross-section is not circular, but sixteen-sided. The pressure is resisted by the framework itself, the envelope being required to be impervious only. The seventeen compartments are separated by partitions of sheet aluminum. There is a system of complete longitudinal bracing between these partitions. Under the main framework, the cars and machinery are carried by a truss about six feet deep which runs the entire length. The cars are boat-shaped, twenty feet long and six feet wide, three and one-half feet high, enclosed in aluminum sheathing. These cars, placed about one hundred feet from the ends, are for the operating force and machinery. The third car, carrying passengers, is built into the keel. [Illustration: WRECK OF THE "ZEPPELIN"] In non-rigid balloons like the _Patrie_, the connecting frame must be carefully attached to the envelope. In this particular machine, cloth flaps were sewed to the bag, and nickel steel tubes then laced in the flaps. With these tubes as a base, a light framework of tubes and wires, covered with a laced-on waterproof cloth, was built up for supporting the load. Braces ran between the various stabilizing and controlling surfaces and the gas bag; these were for the most part very fine wire cables. The weight of the car was concentrated on about seventy feet of the total length of 200 feet. This accounts for the deformation of the envelope shown in the illustration (page 77). The frame and car of this balloon were readily dismantled for transportation. In some of the English dirigibles the cars were suspended by network passing over the top of the balloon. Keeping the Keel Horizontal In the _Zeppelin_, a sliding weight could be moved along the keel so as to cause the center of gravity to coincide with the center of upward pressure in spite of variations in weight and position of gas, fuel, and ballast. In the German balloon _Parseval_, the car itself was movable on a longitudinal suspending cable which carried supporting sheaves. This balloon has figured in recent press notices. It was somewhat damaged by a collision with its shed in March: the sixteen passengers escaped unharmed. A few days later, emergency deflation by the rip-strip was made necessary during a severe storm. In the ordinary non-rigid balloon, the pumping of air between the ballonets aids in controlling longitudinal equilibrium. The pump may be arranged for either hand or motor operation: that in the _Clément-Bayard_ had a capacity of 1800 liters per minute against the pressure of a little over three-fifths of an ounce. The _Parseval_ has two ballonets. Into the rear of these air is pumped at starting. This raises the bow and facilitates ascent on the principle of the inclined surface of an aeroplane. After some elevation is attained, the forward ballonet is also filled. [Illustration: CAR OF THE ZEPPELIN (From the _Transactions_ of the American Society of Mechanical Engineers)] Stability Besides proper distribution of the loads, correct vertical location of the propeller is important if the balloon is to travel on a level keel. In some early balloons, two envelopes side by side had the propeller at the height of the axes of the gas bags and midway between them. The modern forms carry the car, motor, and propeller below the balloon proper. The air resistance is mostly that of the bow of the envelope: but there is some resistance due to the car, and the propeller shaft should properly be at the equivalent center of all resistance, which will be between car and axis of gas bag and nearer the latter than the former. With a single envelope and propeller, this arrangement is impracticable. By using four (or even two) propellers, as in the _Zeppelin_ machine (page 68), it can be accomplished. If only one propeller is employed, horizontal rudder planes must be disposed at such angles and in such positions as to compensate for the improper position of the tractive force. Even on the _Zeppelin_, such planes were employed with advantage (pages 66 and 73). Perfect stability also involves freedom from rolling. This is usually inherent in a balloon, because the center of mass is well below the center of buoyancy: but in machines of the non-rigid type the absence of a ballonet might lead to both rolling and pitching when the gas was partially exhausted. [Illustration: STERN VIEW OF THE ZEPPELIN] What is called "route stability" describes the condition of straight flight. The balloon must point directly in its (independent) course. This involves the use of a steering rudder, and, in addition, of fixed vertical planes, which, on the principle of the vertical partitions of Voisin, probably give some automatic steadiness to the course. To avoid the difficulty or impossibility of holding the head up to the wind at high speeds, an _empennage_ or feathering tail is a feature of all present balloons. The empennage of the _Patrie_ (page 77) consisted of pairs of vertical and horizontal planes at the extreme stern. In the _France_, thirty-two feet in maximum diameter and nearly 200 feet long, empennage planes aggregating about 400 square feet were placed somewhat forward of the stern. In the _Clément-Bayard_, the empennage consisted of cylindro-conical ballonets projecting aft from the stern. A rather peculiar grouping of such ballonets was used about the prolonged stern of the _Ville de Paris_. [Illustration: THE "CLÉMENT-BAYARD"] [Illustration: THE "VILLE DE PARIS"] Rudders and Planes The dirigible has thus several air-resisting or gliding surfaces. The approximately "horizontal" (actually somewhat inclined) planes permit of considerable ascent and descent by the expenditure of power rather than gas, and thus somewhat influence the problem of altitude control. Each of the four sets of horizontal rudder planes on the _Zeppelin_, for example, has, at thirty-five miles per hour, with an inclination equal to one-sixth a right angle, a lifting power of nearly a ton; about equal to that of all of the gas in one of the sixteen compartments. [Illustration: CAR OF THE "LIBERTÉ"] Movable rudders may be either hand or motor-operated. The double vertical steering rudder of the _Ville de Paris_ had an area of 150 square feet. The horizontally pivoted rudders for vertical direction had an area of 130 square feet. Arrangement and Accessories The motor in the _Ville de Paris_ was at the front of the car, the operator behind it. This car had the excessive weight of nearly 700 pounds. The _Patrie_ employed a non-combustible shield over the motor, for the protection of the envelope: its steering wheel was in front and the motor about in the middle of the car. The gasoline tank was under the car, compressed air being used to force the fuel up to the motor, which discharged its exhaust downward at the rear through a spark arrester. Motors have battery and magneto ignition and decompression cocks, and are often carried on a spring-supported chassis. The interesting _Parseval_ propeller has four cloth blades which hang limp when not revolving. When the motor is running, these blades, which are weighted with lead at the proper points, assume the desired form. Balloons usually carry guide ropes at head and stern, the aggregate weight of which may easily exceed a hundred pounds. In descending, the bow rope is first made fast, and the airship then stands with its head to the wind, to be hauled in by the stern rope. For the large French military balloons, this requires a force of about thirty men. The _Zeppelin_ descends in water, being lowered until the cars float, when it is docked like a ship (see page 84). Landing skids are sometimes used, as with aeroplanes. The balloon must have escape valves in the main envelope and ballonets. In addition it has a "rip-strip" at the bottom by which a large cut can be made and the gas quickly vented for the purpose of an emergency descent. Common equipment includes a siren, megaphone, anchor pins, fire extinguisher, acetylene search light, telephotographic apparatus, registering and indicating gages and other instruments, anemometer, possibly carrier pigeons; besides fuel, oil and water for the motor, and the necessary supplies for the crew. The glycerine floated compass of Moisant must now also be included if we are to contemplate genuine navigation without constant recourse to landmarks. Amateur Dirigibles The French Zodiac types of "aerial runabout" displace 700 cubic meters, carrying one passenger with coal gas or two passengers with a mixture of coal gas and hydrogen. The motor is four-cylinder, sixteen horse-power, water-cooled. The stern screw, of seven feet diameter, makes 600 turns per minute, giving an independent speed of nineteen miles per hour. The machine can remain aloft three hours with 165 pounds of supplies. It costs $5000. Hydrogen costs not far from a cent per cubic foot (twenty cents per cubic meter) so that the question of gas leakage may be at least as important as the tire question with automobiles. [Illustration: THE ZODIAC NO. 2 May be deflated and easily transported] The Fort Omaha Plant The Signal Corps post at Fort Omaha has a plant comprising a steel balloon house of size sufficient to house one of the largest dirigibles built, an electrolytic plant for generating hydrogen gas, having a capacity of 3000 cubic feet per hour, a 50,000 cubic foot gas storage tank, and the compressing and carrying equipment involved in preparing gas for shipment at high pressure in steel cylinders. [Illustration: UNITED STATES SIGNAL CORPS BALLOON PLANT AT FORT OMAHA, NEB. (From the _Transactions_ of the American Society of Mechanical Engineers)] Balloon Progress [Illustration: THE "CAROLINE" OF ROBERT BROTHERS, 1784 The ascent terminated tragically] The first aerial buoy of Montgolfier brothers, in 1783, led to the suggestion of Meussier that two envelopes be used; the inner of an impervious material to prevent gas leakage, and the outer for strength. There was perhaps a foreshadowing of the Zeppelin idea. Captive and drifting balloons were used during the wars of the French Revolution: they became a part of standard equipment in our own War of Secession and in the Franco-Prussian conflict. The years 1906 to 1908 recorded rapid progress in the development of the dirigible: the record-breaking _Zeppelin_ trip was in 1909 and Wellman's _America_ exploit in October, 1910. Unfortunately, dirigibles have had a bad record for stanchness: the _Patrie_, _République_, _Zeppelin_ (_I_ and _II_), _Deutschland_, _Clément-Bayard_--all have gone to that bourne whence no balloon returns. [Illustration: THE ASCENT AT VERSAILLES, 1783 The first balloon carrying living beings in the air] [Illustration: PROPOSED DIRIGIBLE Investors were lacking to bring about the realization of this project] It is gratifying to record that Count Zeppelin's latest machine, the _Deutschland II_, is now in operation. During the present month (April, 1911), flights have been made covering 90 miles and upward at speeds exceeding 20 miles per hour with the wind unfavorable. This balloon is intended for use as a passenger excursion vehicle during the coming summer, under contract with the municipality of Düsseldorf. [Illustration: THE "RÉPUBLIQUE"] At the present moment, Neale, in England, is reported to be building a dirigible for a speed of a hundred miles per hour. The Siemens-Schuckart non-rigid machine, nearly 400 feet long and of 500 horse-power, is being tried out at Berlin: it is said to carry fifty passengers.[A] Fabrice, of Munich, is experimenting with the _Inchard_, with a view to crossing the Atlantic at an early date. Mr. Vaniman, partner of Wellman on the _America_ expedition, is planning a new dirigible which it is proposed to fly across the ocean before July 4. The engine, according to press reports, will develop 200 horse-power, and the envelope will be more elongated than that of the _America_. And meanwhile a Chicago despatch describes a projected fifty-passenger machine, to have a gross lifting power of twenty-five tons! [Illustration: THE FIRST FLIGHT FOR THE GORDON-BENNET CUP. Won by Lieut. Frank P. Lahm, U.S.A., 1906. Figures on the map denote distances in kilometers. The cup has been offered annually by Mr. James Gordon-Bennet for international competition under such conditions as may be prescribed by the International Aeronautic Federation.] Germany has a slight lead in number of dirigible balloons--sixteen in commission and ten building. France follows closely with fourteen active and eleven authorized. This accounts for two-thirds of all the dirigible balloons in the world. Great Britain, Italy, and Russia rank in the order named. The United States has one balloon of the smallest size. Spain has, or had, one dirigible. As to aeroplanes, however, the United States and England rank equally, having each about one-fourth as many machines as France (which seems, therefore, to maintain a "four-power standard"). Germany, Russia, and Italy follow, in order, the United States. These figures include all machines, whether privately or nationally owned. Until lately, our own government operated but one aeroplane. A recent appropriation by Congress of $125,000 has led to arrangements for the purchase of a few additional biplanes of the Wright and Curtiss types; and a training school for army officers has been regularly conducted at San Diego, Cal., during the past winter. The Curtiss machine to be purchased is said to carry 700 pounds of dead weight with a sail area of 500 square feet. It is completely demountable and equipped with pontoons. THE QUESTION OF POWER In the year 1810, a steam engine weighed something over a ton to the horse-power. This was reduced to about 200 pounds in 1880. The steam-driven dirigible balloon of Giffard, in 1852, carried a complete power plant weighing a little over 100 pounds per horse-power; about the weight of a modern locomotive. The unsuccessful Maxim flying machine of 1894 brought this weight down to less than 20 pounds. The gasoline engine on the original Wright machines weighed about 5 pounds to the horse-power; those on some recent French machines not far from 2 pounds. Pig iron is worth perhaps a cent a pound. An ordinary steam or gas engine may cost eight cents a pound; a steam turbine, perhaps forty cents. A high grade automobile or a piano may sell for a dollar a pound; the Gnome aeroplane motor is priced at about twenty dollars a pound. This is considerably more than the price of silver. The motor and accessories account for from two-thirds to nine-tenths of the total cost of an aeroplane. A man weighing 150 pounds can develop at the outside about one-eighth of a horse-power. It would require 1200 pounds of man to exert one horse-power. Considered as an engine, then, a man is (weight for weight) only one six-hundredth as effective as a Gnome motor. In the original Wright aeroplane, a weight of half a ton was sustained at the expenditure of about twenty-five horse-power. The motor weight was about one-eighth of the total weight. If traction had been produced by man-power, 30,000 pounds of man would have been necessary: thirty times the whole weight supported. [Illustration: THE GNOME MOTOR (Aeromotion Company of America)] Under the most favorable conditions, to support his own weight of 150 pounds (at very high gliding velocity and a slight angle of inclination, disregarding the weight of sails necessary), a man would need to have the strength of about fifteen men. No such thing as an aerial bicycle, therefore, appears possible. The man can not emulate the bird. [Illustration: SCREW PROPELLER (American Propeller Company)] The power plant of an air craft includes motor, water and water tank, radiator and piping, shaft and bearings, propeller, controlling wheels and levers, carbureter, fuel, lubricating oil and tanks therefor. Some of the weight may eventually be eliminated by employing a two-cycle motor (which gives more power for its size) or by using rotary air-cooled cylinders. Propellers are made light by employing wood or skeleton construction. One eight-foot screw of white oak and spruce, weighing from twelve to sixteen pounds, is claimed to give over 400 pounds of propelling force at a thousand turns per minute. [Illustration: ONE OF THE MOTORS OF THE ZEPPELIN] The cut shows the action of the so-called "four-cycle" motor. Four strokes are required to produce an impulse on the piston and return the parts to their original positions. On the first, or suction stroke, the combustible mixture is drawn into the cylinder, the inlet valve being open and the outlet valve closed. On the second stroke, both valves are closed and the mixture is highly compressed. At about the end of this stroke, a spark ignites the charge, a still greater pressure is produced in consequence, and the energy of the gas now forces the piston outward on its third or "working" stroke, the valves remaining closed. Finally, the outlet valve is opened and a fourth stroke sweeps the burnt gas out of the cylinder. [Illustration: ACTION OF THE FOUR-CYCLE ENGINE] In the "two-cycle" engine, the piston first moves to the left, compressing a charge already present in the cylinder at _F_, and meanwhile drawing a fresh supply through the valve _A_ and passages _C_ to the space _D_. On the return stroke, the exploded gas in _F_ expands, doing its work, while that in _D_ is slightly compressed, the valve _A_ being now closed. When the piston, moving toward the right, opens the passage _E_, the burnt gas rushes out. A little later, when the passage _I_ is exposed, the fresh compressed gas in _D_ rushes through _C_, _B_, and _I_ to _F_. The operation may now be repeated. Only two strokes have been necessary. The cylinder develops power twice as rapidly as before: but at the cost of some waste of gas, since the inlet (_I_) and outlet (_E_) passages are for a brief interval _both open at once_: a condition not altogether remedied by the use of a deflector at _G_. A two-cycle cylinder should give nearly twice the power of a four-cycle cylinder of the same size, and the two-cycle engine should weigh less, per horse-power; but it requires from 10 to 30% more fuel, and fuel also counts in the total weight. [Illustration: ACTION OF TWO-CYCLE ENGINE] The high temperatures in the cylinder would soon make the cast-iron walls red-hot, unless the latter where artificially cooled. The usual method of cooling is to make the walls hollow and circulate water through them. This involves a pump, a quantity of water, and a "radiator" (cooling machine) so that the water can be used over and over again. To cool by air blowing over the surface of the cylinder is relatively ineffective: but has been made possible in automobiles by building fins on the cylinders so as to increase the amount of cooling surface. When the motors are worked at high capacity, or when two-cycle motors are used, the heat is generated so rapidly that this method of cooling is regarded as inapplicable. By rapidly rotating the cylinders themselves through the air, as in motors like the Gnome, air cooling is made sufficiently adequate, but the expenditure of power in producing this rotation has perhaps not been sufficiently regarded. [Illustration: MOTOR AND PROPELLER (Detroit Aeronautic Construction Co.)] Possible progress in weight economy is destined to be limited by the necessity for reserve motor equipment. The engine used is usually the four-cycle, single-acting, four-cylinder gasoline motor of the automobile, designed for great lightness. The power from each cylinder of such a motor is approximately that obtained by dividing the square of the diameter in inches by the figure 2-1/2. Thus a five-inch cylinder should give ten horse-power--at normal piston speed. On account of friction losses and the wastefulness of a screw propeller, not more than half this power is actually available for propulsion. The whole power plant of the _Clément-Bayard_ weighed about eleven pounds to the horse-power. This balloon was 184 feet long and 35 feet in maximum diameter, displacing about 100,000 cubic feet. It carried six passengers, about seventy gallons of fuel, four gallons of lubricating oil, fifteen gallons of water, 600 pounds of ballast, and 130 pounds of ropes. The motor developed 100 horse-power at a thousand revolutions per minute. About eight gallons of fuel and one gallon of oil were consumed per hour when running at the full independent speed of thirty-seven miles per hour. The Wellman balloon _America_ is said to have consumed half a ton of gasoline per twenty-four hours: an eight days' supply was carried. The gas leakage in this balloon was estimated to have been equivalent to a loss of 500 pounds of lifting power per day. The largest of dirigibles, the _Zeppelin_, had two motors of 170 horse-power each. It made, in 1909, a trip of over 800 miles in thirty-eight hours. The engine of the original Voisin cellular biplanes was an eight-cylinder Antoinette of fifty horse-power, set near the rear edge of the lower of the main planes. The Wright motors are placed near the front edge. A twenty-five horse-power motor at 1400 revolutions propelled the Fort Myer machine, which was built to carry two passengers, with fuel for a 125 mile flight: the total weight of the whole flying apparatus being about half a ton. [Illustration: TWO-CYLINDER OPPOSED ENGINE. (From _Aircraft_)] [Illustration: FOUR-CYLINDER VERTICAL ENGINE (The Dean Manufacturing Co.)] The eight-cylinder Antoinette motor on a Farman biplane, weighing 175 pounds, developed thirty-eight horse-power at 1050 revolutions. The total weight of the machine was nearly 1200 pounds, and its speed twenty-eight miles per hour. The eight-cylinder Curtiss motor on the _June Bug_ was air cooled. This aeroplane weighed 650 pounds and made thirty-nine miles per hour, the engine developing twenty-five horse-power at 1200 turns. Resistance of Aeroplanes The chart on page 24 (see also the diagram of page 23) shows that the lifting power of an aeroplane increases as the angle of inclination increases, up to a certain limit. The resistance to propulsion also increases, however: and the ratio of lifting power to resistance is greatest at a very small angle--about five or six degrees. Since the motor power and weight are ruling factors in design, it is important to fly at about this angle. The supporting force is then about two pounds, and the resistance about three-tenths of a pound, per square foot of sail area, if the velocity is that assumed in plotting the chart: namely, about fifty-five miles per hour. But the resistance _R_ indicated on pages 23 and 24 is not the only resistance to propulsion. In addition, we have the frictional resistance of the air sliding along the sail surface. The amount of this resistance is independent of the angle of inclination: it depends directly upon the area of the planes, and in an indirect way on their dimensions in the direction of movement. It also varies nearly with the square of the velocity. At any velocity, then, the addition of this frictional resistance, which does not depend on the angle of inclination, modifies our views as to the desirable angle: and the total resistance reaches a minimum (in proportion to the weight supported) when the angle is about three degrees and the velocity about fifty miles per hour. This is not quite the best condition, however. The skin friction does not vary exactly with the square of the velocity: and when the true law of variation is taken into account, it is found that the _horse-power_ is a minimum at an angle of about five degrees and a speed of about forty miles per hour. The weight supported per horse-power may then be theoretically nearly a hundred pounds: and the frictional resistance is about one-third the direct pressure resistance. This must be regarded as the approximate condition of best effectiveness: not the exact condition, because in arriving at this result we have regarded the sails as square flat planes whereas in reality they are arched and of rectangular form. At the most effective condition, the resistance to propulsion is only about one-tenth the weight supported. Evidently the air is helping the motor. Resistance of Dirigibles If the bow of a balloon were cut off square, its head end resistance would be that given by the rule already cited (page 19): one three-hundredth pound per square foot, multiplied by the square of the velocity. But by pointing the bow an enormous reduction of this pressure is possible. If the head end is a hemisphere (as in the English military dirigible), the reduction is about one-third. If it is a sharp cone, the reduction may be as much as four-fifths. Unless the stern is also tapered, however, there will be a considerable eddy resistance at that point. [Illustration: HEAD END SHAPES] If head end resistance were the only consideration, then for a balloon of given diameter and end shape it would be independent of the length and capacity. The longer the balloon, the better. Again, since the volume of any solid body increases more rapidly than its surface (as the linear dimensions are increased), large balloons would have a distinct advantage over small ones. The smallest dirigible ever built was that of Santos-Dumont, of about 5000 cubic feet. Large balloons, however, are structurally weak: and more is lost by the extra bracing necessary than is gained by reduction of head end resistance. It is probable that the Zeppelin represents the limit of progress in this direction; and even in that balloon, if it had not been that the adoption of a rigid type necessitated great structural strength, it is doubtful if as great a length would have been fixed upon, in proportion to the diameter. The frictional resistance of the air gliding along the surface of the envelope, moreover, invalidates any too arbitrary conclusions. This, as in the aeroplane, varies nearly as the square of the velocity, and is usually considerably greater than the direct head end resistance. Should the steering gear break, however, and the wind strike the _side_ of the balloon, the pressure of the wind against this greatly increased area would absolutely deprive it of dirigibility. A stationary, drifting, or "sailing" balloon may as well have the spherical as well as any other shape: it makes the wind a friend instead of a foe and requires nothing in the way of control other than regulation of altitude. Independent Speed and Time Table The air pressure, direct and frictional resistances, and power depend upon the _relative_ velocity of flying machine and air. It is this relative velocity, not the velocity of the balloon as compared with a point on the earth's surface, that marks the limit of progression. Hence the speed of the wind is an overwhelming factor to be reckoned with in developing an aerial time table. If we wish to travel east at an effective speed of thirty miles per hour, while the wind is blowing due west at a speed of ten miles, our machine must have an independent speed of forty miles. On the other hand, if we wish to travel west, an independent speed of twenty miles per hour will answer. [Illustration: THE SANTOS-DUMONT DIRIGIBLE NO. 2 (1909)] Again, if the wind is blowing north at thirty miles per hour, and the minimum (relative) velocity at which an aeroplane will sustain its load is forty miles per hour, we cannot progress northward any more slowly than at seventy miles' speed. And we have this peculiar condition of things: suppose the wind to be blowing north at fifty miles per hour. The aeroplane designed for a forty mile speed may then face this wind and sustain itself while actually moving backward at an absolute speed (as seen from the earth) of ten miles per hour. We are at the mercy of the wind, and wind velocities may reach a hundred miles an hour. The inherent disadvantage of aerial flight is in what engineers call its "low load factor." That is, the ratio of normal performance required to possible abnormal performance necessary under adverse conditions is extremely low. To make a balloon truly dirigible throughout the year involves, at Paris, for example, as we have seen, a speed exceeding fifty-four miles per hour: and even then, during one-tenth the year, the _effective_ speed would not exceed twenty miles per hour. A time table which required a schedule speed reduction of 60% on one day out of ten would be obviously unsatisfactory. [Illustration: IN THE BAY OF MONACO SANTOS-DUMONT'S NO. 6 The flights terminated with a fall into the sea, happily without injury to the operator] Further, if we aim at excessively high independent speeds for our dirigible balloons, in order to become independent of wind conditions, we soon reach velocities at which the gas bag is unnecessary: that is, a simple wing surface would at those speeds give ample support. The increased difficulty of maintaining rigidity of the envelope, and of steering, at the great pressures which would accompany these high velocities would also operate against the dirigible type. With the aeroplane, higher speed means less sail area for a given weight and a stronger machine. Much higher speeds are probable. We have already a safe margin as to weight per horse-power of motor, and many aeroplane motors are for stanchness purposely made heavier than they absolutely need to be. The Cost of Speed Since the whole resistance, in either type of flying machine, is approximately proportional to the square of the velocity; and since horse-power (work) is the product of resistance and velocity, the horse-power of an air craft of any sort varies about as the cube of the speed. To increase present speeds of dirigible balloons from thirty to sixty miles per hour would then mean eight times as much horse-power, eight times as much motor weight, eight times as rapid a rate of fuel consumption, and (since the speed has been doubled) four times as rapid a consumption of fuel in proportion to the distance traveled. Either the radius of action must be decreased, or the weight of fuel carried must be greatly increased, if higher velocities are to be attained. Present (independent) aeroplane speeds are usually about fifty miles per hour, and there is not the necessity for a great increase which exists with the lighter-than-air machines. We have already succeeded in carrying and propelling fifty pounds of total load or fifteen pounds of passenger load per horse-power of motor, with aeroplanes; the ratio of net load to horse-power in the dirigible is considerably lower; but the question of weight in relation to power is of relatively smaller importance in the latter machine, where support is afforded by the gas and not by the engine. The Propeller Very little effort has been made to utilize paddle wheels for aerial propulsion; the screw is almost universally employed. Every one knows that when a bolt turns in a stationary nut, it moves forward a distance equal to the _pitch_ (lengthwise distance between two adjacent threads) at every revolution. A screw propeller is a bolt partly cut away for lightness, and the "nut" in which it works is water or air. It does not move forward quite as much as its pitch, at each revolution, because any fluid is more or less slippery as compared with a nut of solid metal. The difference between the pitch and the actual forward movement of the vessel at each revolution is called the "slip," or "slip ratio." It is never less than ten or twelve per cent in marine work, and with aerial screws is much greater. Within certain limits, the less the slip, the greater the efficiency of the propeller. Small screws have relatively greater slips and less efficiency, but are lighter. The maximum efficiency of a screw propeller in water is under 80%. According to Langley's experiments, the usual efficiency in air is only about 50%. This means that only half the power of the motor will be actually available for producing forward movement--a conclusion already foreshadowed. In common practice, the pitch of aerial screws is not far from equal to the diameter. The rate of forward movement, if there were no slip, would be proportional to the pitch and the number of revolutions per minute. If the latter be increased, the former may be decreased. Screws direct-connected to the motors and running at high speeds will therefore be of smaller pitch and diameter than those run at reduced speed by gearing, as in the machine illustrated on page 134. The number of blades is usually two, although this gives less perfect balance than would a larger number. The propeller is in many monoplanes placed in _front_: this interferes, unfortunately, with the air currents against the supporting surfaces. There is always some loss of power in the bearings and power-transmitting devices between the motor and propeller. This may decrease the power usefully exerted even to _less_ than half that developed by the motor. GETTING UP AND DOWN: MODELS AND GLIDERS: AEROPLANE DETAILS Launching The Wright machines (at least in their original form) have usually been started by the impetus of a falling weight, which propels them along skids until the velocity suffices to produce ascent. The preferred designs among French machines have contemplated self-starting equipment. This involves mounting the machine on pneumatic-tired bicycle wheels so that it can run along the ground. If a fairly long stretch of good, wide, straight road is available, it is usually possible to ascend. The effect of altitude and atmospheric density on sustaining power is forcibly illustrated by the fact that at Salt Lake City one of the aviators was unable to rise from the ground. [Illustration: WRIGHT BIPLANE ON STARTING RAIL, SHOWING PYLON AND WEIGHT] To accelerate a machine from rest to a given velocity in a given time or distance involves the use of propulsive force additional to that necessary to maintain the velocity attained. Apparently, therefore, any self-starting machine must have not only the extra weight of framework and wheels but also extra motor power. [Illustration: LAUNCHING SYSTEM FOR WRIGHT AEROPLANE (From Brewer's _Art of Aviation_)] Upon closer examination of the matter, we may find a particularly fortunate condition of things in the aeroplane. Both sustaining power and resistance vary with the inclination of the planes, as indicated by the chart on page 24. It is entirely possible to start with no such inclination, so that the direct wind resistance is eliminated. The motor must then overcome only air friction, in addition to providing an accelerating force. The machine runs along the ground, its velocity rapidly increasing. As soon as the necessary speed (or one somewhat greater) is attained, the planes are tilted and the aeroplane rises from the ground. [Illustration: THE NIEUPORT MONOPLANE Self-Starting with an 18 hp. motor (From _The Air Scout_)] The velocity necessary to just sustain the load at a given angle of inclination is called the _critical_ or _soaring_ velocity. For a given machine, there is an angle of inclination (about half a right angle) at which the minimum speed is necessary. This speed is called the "least soaring velocity." If the velocity is now increased, the angle of inclination may be reduced and the planes will soar through the air almost edgewise, apparently with diminished resistance and power consumption. This decrease in power as the speed increases is called _Langley's Paradox_, from its discoverer, who, however, pointed out that the rule does not hold in practice when frictional resistances are included. We cannot expect to actually save power by moving more rapidly than at present; but we should have to provide much more power if we tried to move much more slowly. [Illustration: A BIPLANE (From _Aircraft_)] [Illustration: ELY AT LOS ANGELES (Photo by American Press Association)] Economical and practicable starting of an aeroplane thus requires a free launching space, along which the machine may accelerate with nearly flat planes: a downward slope would be an aid. When the planes are tilted for ascent, after attaining full speed, quick control is necessary to avoid the possibility of a back-somersault. A fairly wide launching platform of 200 feet length would ordinarily suffice. The flight made by Ely in January of this year, from San Francisco to the deck of the cruiser _Pennsylvania_ and back, demonstrated the possibility of starting from a limited area. The wooden platform built over the after deck of the warship was 130 feet long, and sloped. On the return trip, the aeroplane ran down this slope, dropped somewhat, and then ascended successfully. If the effort is made to ascend at low velocities, then the motor power must be sufficient to propel the machine at an extreme angle of inclination--perhaps the third of a right angle, approximating to the angle of least velocity for a given load. According to Chatley, this method of starting by Farman at Issy-les-Moulineaux involved the use of a motor of fifty horse-power: while Roe's machine at Brooklands rose, it is said, with only a six horse-power motor. Descending [Illustration: TRAJECTORY DURING DESCENT] What happens when the motor stops? The velocity of the machine gradually decreases: the resistance to forward movement stops its forward movement and the excess of weight over upward pressure due to velocity causes it to descend. It behaves like a projectile, but the details of behavior are seriously complicated by the variation in head resistance and sustaining force due to changes in the angle of the planes. The "angle of inclination" is now not the angle made by the planes with the horizontal, but the angle which they make with the path of flight. Theory indicates that this should be about two-thirds the angle which the path itself makes with the horizontal: that is, the planes themselves are inclined downward toward the front. The forces which determine the descent are fixed by the velocity and the angle between the planes and the path of flight. Manipulation of the rudders and main planes or even the motor may be practised to ensure lancing to best advantage; but in spite of these (or perhaps on account of these) scarcely any part of aviation offers more dangers, demands more genius on the part of the operator, and has been less satisfactorily analyzed than the question of "getting down." It is easy to stay up and not very hard to "get up," weather conditions being favorable; but it is an "all-sufficient job" to _come down_. Under the new rules of the International Aeronautic Federation, a test flight for a pilot's license must terminate with a descent (motor stopped) in which the aviator is to land within fifty yards of the observers and come to a full stop inside of fifty yards therefrom. The elevation at the beginning of descent must be at least 150 feet. [Illustration: DESCENDING] Gliders If the motor and its appurtenances, and some of the purely auxiliary planes, be omitted, we have a _glider_. The glider is not a toy; some of the most important problems of balancing may perhaps be some day solved by its aid. Any boy may build one and fly therewith, although a large kite promises greater interest. The cost is trifling, if the framework is of bamboo and the surfaces are cotton. Areas of glider surfaces frequently exceed 100 square feet. This amount of surface is about right for a person of moderate weight if the machine itself does not weigh over fifty pounds. By running down a slope, sufficient velocity may be attained to cause ascent; or in a favorable wind (up the slope) a considerable backward flight may be experienced. Excessive heights have led to fatal accidents in gliding experiments. [Illustration: THE WITTEMAN GLIDER] Models The building of flying models has become of commercial importance. It is not difficult to attain a high ratio of surface to weight, but it is almost impossible to get motor power in the small units necessary without exceeding the permissible limit of motor weight. No gasoline engine or electric motor can be made sufficiently light for a toy model. Clockwork springs, if especially designed, may give the necessary power for short flights, but no better form of power is known just now than the twisted rubber band. For the small boy, a biplane with sails about eighteen inches by four feet, eighteen inches apart, anchored under his shoulders by six-foot cords while he rides his bicycle, will give no small amount of experience in balancing and will support enough of a load to make the experiment interesting. Some Details: Balancing [Illustration: FRENCH MONOPLANE (From _Aircraft_)] It is easily possible to compute the areas, angles, and positions of auxiliary planes to give desired controlling or stabilizing effects; but the computation involves the use of accurate data as to positions of the various weights, and on the whole it is simpler to correct preliminary calculations by actually supporting the machine at suitable points and observing its balance. Stability is especially uncertain at very small angles of inclination, and such angles are to be avoided whether in ordinary operation or in descent. The necessity for rotating main planes in order to produce ascent is disadvantageous on this ground; but the proposed use of sliding or jockey weights for supplementary balancing appears to be open to objections no less serious. Steering may be perceptibly assisted, in as delicately a balanced device as the aeroplane, by the inclination of the body of the operator, just as in a bicycle. The direction of the wind in relation to the required course may seriously influence the steering power. Suppose the course to be northeast, the wind east, the independent speed of the machine and that of the wind being the same. The car will head due north. By bringing the rudder in position (_a_), the course may be changed to north, or nearly so, the wind exerting a powerful pressure on the rudder; but if a more easterly or east-northeast course be desired, and the rudder be thrown into the usual position therefor (_b_), it will exert no influence whatever, because it is moving before the wind and precisely at the speed of the wind. [Illustration: A PROBLEM IN STEERING] It might be thought that, following analogies of marine engineering, the center of gravity of an aeroplane should be kept low. The effect of any unbalanced pressure or force against the widely extended sails of the machine is to rotate the whole apparatus about its center of gravity. The further the force from the center of gravity, the more powerful is the force in producing rotation. The defect in most aeroplanes (especially biplanes) is that the center of gravity is _too_ low. If it could be made to coincide with the center of disturbing pressure, there would be no unbalancing effect from the latter. It is claimed that the steadiest machines are those having a high center of gravity; and the claim, from these considerations, appears reasonable. [Illustration: LEJEUNE BIPLANE (385 LBS., 10-12 HP.)] Weights It has been found not difficult to keep down the weight of framework and supporting surfaces to about a pound per square foot. The most common ratio of surface to total weight is about one to two: so that the machinery and operator will require one square foot of surface for each pound of their weight. On this basis, the smallest possible man-carrying aeroplane would have a surface scarcely below 250 square feet. Most biplanes have twice this surface: a thousand square feet seems to be the limit without structural weakness. Some recent French machines, designed for high speeds, show a greatly increased ratio of weight to surface. The _Hanriot_, a monoplane with wings upwardly inclined toward the outer edge, carries over 800 pounds on less than 300 square feet. The Farman monoplane of only 180 square feet sustains over 600 pounds. The same aviator's racing biplane is stated to support nearly 900 pounds on less than 400 square feet. [Illustration: THE TELLIER TWO-SEAT SIX-CYLINDER MONOPLANE AT THE PARIS SHOW One of this type has been sold to the Russian Government (From _Aircraft_)] Motor weights can be brought down to about two pounds per horse-power, but such extreme lightness is not always needed and may lead to unreliability of operation. The effect of an accumulation of ice, sleet, snow, rain, or dew might be serious in connection with flights in high altitudes or during bad weather. After one of his last year's flights at Étampes Mr. Farman is said to have descended with an extra load of nearly 200 pounds on this account. With ample motor power, great flexibility in weight sustention is made possible by varying the inclination of the planes. In January of this year, Sommer at Douzy carried six passengers in a large biplane on a cross-country flight: and within the week afterward a monoplane operated by Le Martin flew for five minutes with the aeronaut and seven passengers, at Pau. The total weight lifted was about half a ton, and some of the passengers must have been rather light. The two-passenger Fort Myer biplane of the Wright brothers is understood to have carried about this total weight. These records have, however, been surpassed since they were noted. Bréguet, at Douai, in a deeply-arched biplane of new design, carried eleven passengers, the total load being 2602 pounds, and that of aeronaut and passengers alone 1390 pounds. The flight was a short one, at low altitude; but the same aviator last year made a long flight with five passengers, and carried a load of 1262 pounds at 62 miles per hour. And as if in reply to this feat, Sommer carried a live load of 1436 pounds (13 passengers) for nearly a mile, a day or two later, at Mouzon. One feels less certain than formerly, now, in the snap judgment that the heavier-than-air machine will never develop the capacity for heavy loads. [Illustration: A MONOPLANE (From _Aircraft_)] Miscellaneous French aviators are fond of employing a carefully designed car for the operator and control mechanism. The Wright designs practically ignore the car: the aviator sits on the forward edge of the lower plane with his legs hanging over. It has been found that auxiliary planes must not be too close to the main wings: a gap of a distance about 50% greater than the width of the widest adjacent plane must be maintained if interference with the supporting air currents is to be avoided. Main planes are now always arched; auxiliary planes, not as universally. The concave under surface of supporting wings has its analogy in the wing of the bird and had long years since been applied in the parachute. [Illustration: CARS AND FRAMEWORK] The car (if used) and all parts of the framework should be of "wind splitter" construction, if useless resistance is to be avoided. The ribs and braces of the frame are of course stronger, weight for weight, in this shape, since a narrow deep beam is always relatively stronger than one of square or round section. Excessive frictional resistance is to be avoided by using a smoothly finished fabric for the wings, and the method of attaching this fabric to the frame should be one that keeps it as flat as possible at all joints. [Illustration: SOME DETAILS] The sketches give the novel details of some machines recently exhibited at the Grand Central Palace in New York. The stabilizing planes were invariably found in the rear, in all machines exhibited. The Things to Look After The operator of an aeroplane has to do the work of at least two men. No vessel in water would be allowed to attain such speeds as are common with air craft, unless provided with both pilot and engineer. The aviator is his own pilot and his own engineer. He must both manage his propelling machinery and steer. Separate control for vertical rudders, elevating rudders and ailerons, for starting the engine; the adjustment of the carbureter, the spark, and the throttle to get the best results from the motor; attention to lubrication and constant watchfulness of the water-circulating system: these are a few of the things for him to consider; to say nothing of the laying of his course and the necessary anticipation of wind and altitude conditions. These things demand great resourcefulness, but--for their best control--involve also no small amount of scientific knowledge. For example, certain adjustments at the motor may considerably increase its power, a possibly necessary increase under critical conditions: but if such adjustments also decrease the motor efficiency there must be a nice analysis of the two effects so that extra power may not be gained at too great a cost in radius of action. [Illustration: SOME RECENT FRENCH MACHINES (From _Aircraft_)] The whole matter of flight involves both sportsman's and engineers problems. Wind gusts produce the same effects as "turning corners"; or worse--rapidly changing the whole balance of the machines and requiring immediate action at two or three points of control. Both ascent and descent are influenced by complicated laws and are scarcely rendered safe--under present conditions--by the most ample experience. A lateral air current bewilders the steering and also demands special promptness and skill. To avoid disturbing surface winds, even over open country, a minimum flying height of 300 feet is considered necessary. This height, furthermore, gives more choice in the matter of landing ground than a lower elevation. When complete and automatic balance shall have been attained--as it must be attained--we may expect to see small amateur aeroplanes flying along country roads at low elevations--perhaps with a guiding wheel actually in contact with the ground. They will cost far less than even a small automobile, and the expense for upkeep will be infinitely less. The grasshopper will have become a water-spider. SOME AEROPLANES--SOME ACCOMPLISHMENTS [Illustration: ORVILLE WRIGHT AT FORT MYER, VA., 1908] [Illustration: THE FIRST BALLOON FLIGHT ACROSS THE BRITISH CHANNEL More than a century before Blériot's feat, Blanchard crossed from Dover to Calais] The Wright biplane has already been shown (see pages 31, 37, 121, 122). It was distinguished by the absence of a wheel frame or car and by the wing-warping method of stabilizing. Later Wright machines have the spring frame and wheels for self-starting. The best known aeroplane of this design was built to meet specifications of the United States Signal Corps issued in 1907. It was tried out during 1908 at Fort Myer, Va., while one of the Wright brothers was breaking all records in Europe: making over a hundred flights in all, first carrying a passenger and attaining the then highest altitude (360 feet) and greatest distance of flight (seventy-seven miles). [Illustration: WRIGHT MOTOR. DIMENSIONS IN MILLIMETERS (From Petit's _How to Build an Aeroplane_)] The ownership of the Wrights in the wing-warping method of control is still the subject of litigation. The French infringers, it is stated, concede priority of application to the Wright firm, but maintain that such publicity was given the device that it was in general use before it was patented. The Fort Myer machine had sails of forty feet spread, six and one-half feet deep, with front elevating planes three by sixteen feet. It made about forty miles per hour with two passengers. The apparatus was specified to carry a passenger weight of 350 pounds, with fuel for a 125-mile flight. The main planes were six feet apart. The steering rudder (double) was of planes one foot deep and nearly six feet high. The four-cylinder-four-cycle, water-cooled motor developed twenty-five horse-power at 1400 revolutions. The two propellers, eight and one-half feet in diameter, made 400 revolutions. The flight by Mr. Wilbur Wright from the Statue of Liberty to the tomb of General Grant, in New York, 1909, and the exploits of his brother in the same year, when a new altitude record of 1600 feet was made and H.R.H. the Crown Prince of Germany was taken up as a passenger, are only specimens of the later work done by these pioneers in aerial navigation. Like the Wrights, the Voisin firm from the beginning adhered firmly to the biplane type of machine. The sketch gives dimensions of one of the early cellular forms built for H. Farman (see illustration, page 147). The metal screw makes about a thousand revolutions. The wings are of india rubber sheeting on an ash frame, the whole frame and car body being of wood, the latter covered with canvas and thirty inches wide by ten feet long. The engine weighed 175 pounds. The whole weight of this machine was nearly 1200 pounds; that built later for Delagrange was brought under a thousand pounds. The ratio of weight to main surface in the Farman aeroplane was about 2-3/4 to 1. A modified cellular biplane also built for Farman had a main wing area of 560 square feet, the planes being seventy-nine inches wide and only fifty-nine inches apart. The tail was an open box, seventy-nine inches wide and of about ten feet spread. The cellular partitions in this tail were pivoted along the vertical front edges so as to serve as steering rudders. The elevating rudder was in front. The total weight was about the same as that of the first machine and the usual speed twenty-eight miles per hour. [Illustration: VOISIN-FARMAN BIPLANE] Henry Farman has been flying publicly since 1907. He made the first circular flight of one kilometer, and attained a speed of about a mile a minute, in the year following. In 1909 he accomplished a trip of nearly 150 miles, remaining four hours in the air. Farman was probably the first man to ascend with two passengers. [Illustration: THE CHAMPAGNE GRAND PRIZE WON BY HENRY FARMAN 80 Kilometers in 3 hours] [Illustration: FARMAN'S FIRST BIPLANE AT ISSY-LES-MOULINEAUX Returning to the Hangar After a Flight] The _June Bug_, one of the first Curtiss machines, is shown below. This was one of the lightest of biplanes, having a wing spread of forty-two feet and an area of 370 square feet. The wings were transversely arched, being furthest apart at the center: an arrangement which has not been continued. It had a box tail, with a steering rudder of about six square feet area, _above_ the tail. The horizontal rudder, in front, had a surface of twenty square feet. Four triangular ailerons were used for stability. The machine had a landing frame and wheels, made about forty miles per hour, and weighed, in operation, 650 pounds. [Illustration: THE "JUNE BUG"] Mr. Curtiss first attained prominence in aviation circles by winning the _Scientific American_ cup by his flight at the speed of fifty-seven miles per hour, in 1908. In the following year he exhibited intricate curved flights at Mineola, and circled Governor's Island in New York harbor. In 1910 he made his famous flight from Albany to New York, stopping _en route_, as prearranged. At Atlantic City he flew fifty miles over salt water. A flight of seventy miles over Lake Erie was accomplished in September of the same year, the return trip being made the following day. On January 26, 1911, Curtiss repeatedly ascended and descended, with the aid of hydroplanes, in San Diego bay, California: perhaps one of the most important of recent achievements. It is understood that Mr. Curtiss is now attempting to duplicate some of these performances under the high-altitude conditions of Great Salt Lake. According to press reports, he has been invited to give a similar demonstration before the German naval authorities at Kiel. [Illustration: CURTIS BIPLANE (Photo by Levick, N.Y.)] [Illustration: CURTISS' HYDRO-AEROPLANE AT SAN DIEGO GETTING UNDER WAY (From the _Columbian Magazine_)] The _aeroscaphe_ of Ravard was a machine designed to move either on water or in air. It was an aeroplane with pontoons or floaters. The supporting surface aggregated 400 square feet, and the gross weight was about 1100 pounds. A fifty horse-power Gnome seven-cylinder motor at 1200 revolutions drove two propellers of eight and ten and one-half feet diameter respectively: the propellers being mounted one behind the other on the same shaft. [Illustration: FLYING OVER THE WATER AT FIFTY MILES PER HOUR Curtiss at San Diego Bay (From the _Columbian Magazine_)] Ely's great shore-to-warship flight was made without the aid of the pontoons which he carried. Ropes were stretched across the landing platform, running over sheaves and made fast to heavy sand bags. As a further precaution, a canvas barrier was stretched across the forward end of the platform. The descent brought the machine to the platform at a distance of forty feet from the upper end: grappling hooks hanging from the framework of the aeroplane then caught the weighted ropes, and the speed was checked (within about sixty feet) so gradually that "not a wire or bolt of the biplane was injured." [Illustration: BLÉRIOT-VOISIN CELLULAR BIPLANE WITH PONTOONS Hauled by a Motor Boat] [Illustration: LATHAM'S "ANTOINETTE"] [Illustration: JAMES J. WARD AT LEWISTON FAIR, IDAHO (Photo copyright 1910 by Burns) Flying Machine Mfg. Co. Biplane (30 hp. Motor)] [Illustration: MARCEL PENOT IN THE MOHAWK BIPLANE, Mineola to Hicksville, L. I. 26 miles cross-country in 30 minutes (50 hp. Harriman Engine)] Recent combinations of aeroplane and automobile, and aeroplane with motor boat, have been exhibited. One of the latter devices is like any monoplane, except that the lower part is a water-tight aluminum boat body carrying three passengers. It is expected to start of itself from the water and to fly at a low height like a flying fish at a speed of about seventy-five miles per hour. Should anything go wrong, it is capable of floating on the water. In the San Diego Curtiss flights, the machine skimmed along the surface of the bay, then rose to a height of a hundred feet, moved about two miles through the air in a circular course, and finally alighted close to its starting-point in the water. Turns were made in water as well as in air, a speed of forty miles per hour being attained while "skimming." The "hydroplanes" used are rigid flat surfaces which utilize the pressure of the water for sustention, just as the main wings utilize air pressure. On account of the great density of water, no great amount of surface is required: but it must be so distributed as to balance the machine. The use of pontoons makes it possible to rest upon the water and to start from rest. A trip like Ely's could be made without a landing platform, with this type of machine; the aeroplane could either remain alongside the war vessel or be hoisted aboard until ready to venture away again. There are various other biplanes attracting public attention in this country. In France the tendency is all toward the monoplane form, and many of the "records" have, during the past couple of years, passed from the former to the latter type of machine. The monoplane is simpler and usually cheaper. The biplane may be designed for greater economy in weight and power. Farman has lately experimented with the monoplane type of machine: the large number of French designs in this class discourages any attempt at complete description. [Illustration: SANTOS-DUMONT'S "DEMOISELLE"] The smallest of aeroplanes is the Santos-Dumont _Demoiselle_. The original machine is said to have supported 260 pounds on 100 square feet of area, making a speed of sixty miles per hour. Its proprietor was the first aviator in Europe of the heavier-than-air class. After having done pioneer work with dirigible balloons, he won the Deutsch prize for a hundred meter aeroplane flight (the first outside of the United States) in 1906; the speed being twenty-three miles per hour. His first flight, of 400 feet, in a monoplane was made in 1907. [Illustration: BLÉRIOT MONOPLANE] The master of the monoplane has been Louis Blériot. Starting in 1907 with short flights in a Langley type of machine, he made his celebrated cross-country run, and the first circling flights ever achieved in a monoplane, the following year. On July 25, 1909, he crossed the British Channel, thirty-two miles, in thirty-seven minutes. [Illustration: LATHAM'S FALL INTO THE CHANNEL] The Channel crossing has become a favorite feat. Mr. Latham, only two days after Blériot, all but completed it in his Antoinette monoplane. De Lesseps, in a Blériot machine, was more fortunate. Sopwith, last year, won the de Forest prize of $20,000 by a flight of 174 miles from England into Belgium. The ill-fated Rolls made the round trip between England and France. Grace, contesting for the same prize, reached Belgium, was driven back to Calais, started on the return voyage, and vanished--all save some few doubtful relics lately found. Moisant reached London from Paris--the first trip on record between these cities without change of conveyance: and one which has just been duplicated by Pierre Prier, who, on April 12, made the London to Paris journey, 290 miles, in 236 minutes, without a stop. This does not, however, make the record for a continuous flight: which was attained by Tabuteau, who at Buc, on Dec. 30, 1910, flew around the aerodrome for 465 minutes at the speed of 48-1/2 miles per hour. Other famous crossings include those of the Irish Sea, 52 miles, by Loraine; Long Island Sound, 25 miles, by Harmon; and Lake Geneva, 40 miles, by Defaux. It was just about a century ago that Cayley first described a soaring machine, heavier than air, of a form remarkably similar to that of the modern aeroplane. Aside from Henson's unsuccessful attempt to build such a machine, in 1842, and Wenham's first gliding experiments with a triplane in 1857, soaring flight made no real progress until Langley's experiments. That investigator, with Maxim and others, ascertained those laws of aerial sustention the application of which led to success in 1903. [Illustration: DE LESSEPS IN A BLÉRIOT CROSSING THE CHANNEL (Photo by Levick, N.Y.)] The eight years since have held the crowded hours of aviation. Before this book is printed, it may be rendered obsolete by new developments. The exploits of Paulhan, of R. E. Peltèrie since 1907, Bell's work with his tetrahedral kites--all have been either stimulating or directly fruitful. Delagrange began to break speed records in 1908. A year later he attained a speed of fifty miles. The first woman to enjoy an aeroplane voyage was Mme. Delagrange, in Turin, in 1908. [Illustration: THE MAXIM AEROPLANE] [Illustration: LANGLEY'S AEROPLANE (1896) Steam driven] The first flight in England by an English-built machine was made in January, 1909. That year, Count de Lambert flew over Paris, and in 1910 Grahame-White circled his machine over the city of Boston. The year 1910 surpassed all its predecessors in increasing the range and control of aeroplanes; over 1500 ascents were made by Wright machines alone; but 1911 promises to show even greater results. Three men made cross-country flights from Belmont Park to the Statue of Liberty and back, in New York;[B] at least five men attained altitudes exceeding 9,000 feet. Hamilton made the run from New York to Philadelphia and return, in June. The unfortunate Chavez all but abolished the fames of Hannibal and Napoleon by crossing the icy barrier of the Alps, from Switzerland to Italy--in forty minutes! [Illustration: ROBART MONOPLANE.] Tabuteau, almost on New Year's eve, broke all distance records by a flight of 363 miles in less than eight hours; while Barrier at Memphis probably reached a speed of eighty-eight miles per hour (timing unofficial). With the new year came reports of inconceivable speeds by a machine skidding along the ice of Lake Erie; the successful receipt by Willard and McCurdy of wireless messages from the earth to their aeroplanes; and the proposal by the United States Signal Corps for the use of flying machines for carrying Alaskan mails. [Illustration: VINA MONOPLANE.] McCurdy all but succeeded in his attempt to fly from Key West to Havana, surpassing previous records by remaining aloft above salt water while traveling eighty miles. Lieutenant Bague, in March, started from Antibes, near Nice, for Corsica. After a 124-mile flight, breaking all records for sea journeys by air, he reached the islet of Gorgona, near Leghorn, Italy, landing on bad ground and badly damaging his machine. The time of flight was 5-1/2 hours. Bellinger completed the 500-mile "accommodation train" flight from Vincennes to Pau; Vedrine, on April 12, by making the same journey in 415 minutes of actual flying time, won the Béarn prize of $4000; Say attained a speed of 74 miles per hour in circular flights at Issy-les-Moulineaux. Aeroplane flights have been made in Japan, India, Peru, and China. One of the most spectacular of recent achievements is that of Renaux, competing for the Michelin Grand Prize. A purse of $20,000 was offered in 1909 by M. Michelin, the French tire manufacturer, for the first successful flight from Paris to Clermont-Ferrand--260 miles--in less than six hours. The prize was to stand for ten years. It was prescribed that the aviator must, at the end of the journey, circle the tower of the Cathedral and alight on the summit of the Puy de Dome--elevation 4500 feet--on a landing place measuring only 40 by 100 yards, surrounded by broken and rugged ground and usually obscured by fog. The flight was attempted last year by Weymann, who fell short of the goal by only a few miles. Leon Morane met with a serious accident, a little later, while attempting the trip with his brother as a passenger. Renaux completed the journey with ease in his Farman biplane, carrying a passenger, his time being 308 minutes. This Michelin Grand Prize is not to be confused with the Michelin Trophy of $4000 offered yearly for the longest flight in a closed circuit. Speeds have increased 50% during the past year; even with passengers, machines have moved more than a mile a minute: average motor capacities have been doubled or tripled. The French men and machines hold the records for speed, duration, distance, and (perhaps) altitude. The highest altitude claimed is probably that attained by Garros at Mexico City, early this year--12,052 feet above sea level. The world's speed record for a two-man flight appears to be that of Foulois and Parmalee, made at Laredo, Texas, March 3, 1911: 106 miles, cross-country, in 127 minutes. Three-fourths of all flights made up to this time have been made in France--a fair proportion, however, in American machines. NOTE The rapidity with which history is made in aeronautics is forcibly suggested by the revision of text made necessary by recent news. The new _Deutschland_ has met the fate of its predecessors; the Paris-Rome-Turin flight is at this moment under way; and Lieutenant Bayne, attempting once more his France-to-Corsica flight, has--for the time being at least--disappeared. THE POSSIBILITIES IN AVIATION Men now fly and will probably keep on flying; but aviation is still too hazardous to become the popular sport of the average man. The overwhelmingly important problem with the aeroplane is that of stability. These machines must have a better lateral balance when turning corners or when subjected to wind gusts: and the balance must be automatically, not manually, produced. [Illustration: BLANC MONOPLANE] Other necessary improvements are of minor urgency and in some cases will be easy to accomplish. Better mechanical construction, especially in the details of attachments, needs only persistence and common sense. Structural strength will be increased; the wide spread of wing presents difficulties here, which may be solved either by increasing the number of superimposed surfaces, as in triplanes, or in some other manner. Greater carrying capacity--two men instead of one--may be insisted upon: and this leads to the difficult question of motor weights. The revolving air-cooled motor may offer further possibilities: the two-cycle idea will help if a short radius of action is permissible: but a weight of less than two pounds to the horse-power seems to imply, almost essentially, a lack of ruggedness and surety of operation. A promising field for investigation is in the direction of increasing propeller efficiencies. If such an increase can be effected, the whole of the power difficulty will be greatly simplified. [Illustration: MELVIN VANIMAN TRIPLANE] [Illustration: JEAN DE CRAWHEZ TRIPLANE] [Illustration: A TRIPLANE] This same motor question controls the proposal for increased speed. The use of a reserve motor would again increase weights; though not necessarily in proportion to the aggregate engine capacity. Perhaps something may be accomplished with a gasoline turbine, when one is developed. In any case, no sudden increase in speeds seems to be probable; any further lightening of motors must be undertaken with deliberation and science. If much higher maximum speeds are attained, there will be an opportunity to vary the speed to suit the requirements. Then clutches, gears, brakes, and speed-changing devices of various sorts will become necessary, and the problem of weights of journal bearings--already no small matter--will be made still more serious. And with variable speed must probably come variable sail area--in preference to tilting--so that the fabric must be reefed on its frame. Certainly two men, it would seem, will be needed! Better methods for starting are required. The hydroplane idea promises much in this respect. With a better understanding and control of the conditions associated with successful and safe descent--perhaps with improved appliances therefor--the problem of ascent will also be partly solved. If such result can be achieved, these measures of control must be made automatic. The building of complete aeroplanes to standard designs would be extremely profitable at present prices, which range from $2500 to $5000. Perhaps the most profitable part would be in the building of the motor. The framing and fabric of an ordinary monoplane could easily be constructed at a cost below $300. The propeller may cost $50 more. The expense for wires, ropes, etc., is trifling; and unless special scientific instruments and accessories are required, all of the rest of the value lies in the motor and its accessories. Within reasonable limits, present costs of motors vary about with the horse-power. The amateur designer must therefore be careful to keep down weight and power unless he proposes to spend money quite freely. The Case of the Dirigible Not very much is being heard of performances of dirigible balloons just at present. They have shown themselves to be lacking in stanchness and effectiveness under reasonable variations of weather. We must have fabrics that are stronger for their weight and more impervious. Envelopes must be so built structurally as to resist deformation at high speeds, without having any greatly increased weight. A cheap way of preparing pure hydrogen gas is to be desired. Most important of all, the balloon must have a higher speed, to make it truly dirigible. This, with sufficient steering power, will protect it against the destructive accidents that have terminated so many balloon careers. Here again arises the whole question of power in relation to motor weight, though not as formidably as is the case with the aeroplane. The required higher speeds are possible now, at the cost merely of careful structural design, reduced radius of action, and reduced passenger carrying capacity. Better altitude control will be attained with better fabrics and the use of plane fin surfaces at high speeds. The employment of a vertically-acting propeller as a somewhat wasteful but perhaps finally necessary measure of safety may also be regarded as probable. [Illustration: GIRAUDON'S WHEEL AEROPLANE] The Orthopter The _aviplane_, _ornithoptère_ or _orthopter_ is a flying machine with bird-like flapping wings, which has received occasional attention from time to time, as the result of a too blind adherence to Nature's analogies. Every mechanical principle is in favor of the screw as compared with any reciprocating method of propulsion. There have been few actual examples of this type: a model was exhibited at the Grand Central Palace in New York in January of this year. The mechanism of an orthopter would be relatively complex, and the flapping wings would have to "feather" on their return stroke. The flapping speed would have to be very high or the surface area very great. This last requirement would lead to structural difficulties. Propulsion would not be uniform, unless additional complications were introduced. The machine would be the most difficult of any type to balance. The motion of a bird's wing is extremely complicated in its details--one that it would be as difficult to imitate in a mechanical device as it would be for us to obtain the structural strength of an eagle's wing in fabric and metal, with anything like the same extent of surface and limit of weight. According to Pettigrew, the efficiency of bird and insect flight depends largely upon the elasticity of the wing. Chatley gives the ratio of area to weight as varying from fifty (gnat) to one-half (Australian crane) square feet per pound. The usual ratio in aeroplanes is from one-third to one-half. About the only advantages perceptible with the orthopter type of machine would be, first, the ability "to start from rest without a preliminary surface glide"; and second, more independence of irregularity in air currents, since the propulsive force is exerted over a greater extent than is that of a screw propeller. The Helicopter The _gyroplane_ or _helicopter_ was the type of flying machine regarded by Lord Kelvin as alone likely to survive. It lifts itself by screw propellers acting vertically. This form was suggested in 1852. When only a single screw was used, the whole machine rotated about its vertical axis. It was attempted to offset this by the use of vertical fin-planes: but these led to instability in the presence of irregular air currents. One early form had two oppositely-pitched screws driven by a complete steam engine and boiler plant. One of the Cornu helicopters had adjustable inclined planes under the two large vertically propelling screws. The air which slipped past the screws imposed a pressure on the inclined planes which was utilized to produce horizontal movement in any desired direction--if the wind was not too adverse. A gasoline engine was carried in a sort of well between the screws. [Illustration: BRÉGUET GYROPLANE DURING CONSTRUCTION (Helicopter type)] The helicopter may be regarded as the limiting type of aeroplane, the sail area being reduced nearly to zero; the wings becoming mere fins, the smaller the better. It therefore requires maximum motor power and is particularly dependent upon the development of an excessively light motor. It is launched and descends under perfect control, without regard to horizontal velocity. It has very little exposed surface and is therefore both easy to steer and independent of wind conditions. By properly arranging the screws it can be amply balanced: but it must have a particularly stout and strong frame. The development of this machine hinges largely on the propeller. It is not only necessary to develop _power_ (which means force multiplied by velocity) but actual propulsive vertical _force_: and this must exceed or at least equal the whole weight of the machine. From ten to forty pounds of lifting force per horse-power have been actually attained: and with motors weighing less than five pounds there is evidently some margin. The propellers are of special design, usually with very large blades. Four are commonly used: one, so to speak, at each "corner" of the machine. The helicopter is absolutely dependent upon its motors. It cannot descend safely if the power fails. If it is to do anything but ascend and descend it must have additional propulsive machinery for producing horizontal movement. Composite Types The aeroplane is thus particularly weak as to stability, launching, and descending: but it is economical in power because it uses the air to hold itself up. The dirigible balloon is lacking in power and speed, but can ascend and descend safely, even if only by wasteful methods; and it can carry heavy weights, which are impossible with the structurally fragile aeroplane. The helicopter is wasteful in power, but is stable and sure in ascending and descending, providing only that the motor power does not fail. Why, then, not combine the types? An aeroplane-dirigible would be open to only one objection: on the ground of stability. The dirigible-helicopter would have as its only disadvantage a certain wastefulness of power, while the aeroplane-helicopter would seem to have no drawback whatever. All three combinations have been, or are being, tried. An Italian engineer officer has designed a balloon-aeroplane. The balloon is greatly flattened, or lens-shaped, and floats on its side, presenting its edge to the horizon--if inclination be disregarded. With some inclination, the machine acts like an aeroplane and is partially self-sustaining at any reasonable velocity. The use of a vertically-acting screw on a dirigible combines the features of that type and the helicopter. This arrangement has also been the subject of design (as in Captain Miller's flexible balloon) if not of construction. The combination of helicopter and aeroplane seems especially promising: the vertical propellers being employed for starting and descending, as an emergency safety feature and perhaps for aid in stabilizing. The fact that composite types of flying machine have been suggested is perhaps, however, an indication that the ultimate type has not yet been established. What is Promised The flying machine will probably become the vehicle of the explorer. If Stanley had been able to use a small high-powered dirigible in the search for Livingstone, the journey would have been one of hours as compared with months, the food and general comfort of the party would have been equal in quality to those attainable at home, and the expense in money and in human life would have been relatively trifling. [Illustration: WELLMAN'S AMERICA (From Wellman's _Aerial Age_)] Most readers will remember the fate of Andrée, and the projected polar expeditions of Wellman in 1907 and 1909. Misfortune accompanied both attempts; but one has only to read Peary's story of the dogged tramp over the Greenland ice blink to realize that danger and misfortune in no less degree have accompanied other plans of Arctic pioneering. With proper design and the right men, it does not seem unreasonable to expect that a hundred flying machines may soar above Earth's invisible axial points during the next dozen years.[C] The report of Count Zeppelin's Spitzbergen expedition of last year has just been made public. This was undertaken to ascertain the adaptability of flying machines for Arctic navigation. Besides speed and radius of action, the conclusive factors include that of freedom from such breakdowns as cannot be made good on the road. For exploration in other regions, the balloon or the aeroplane is sure to be employed. Rapidity of progress without fatigue or danger will replace the floundering through swamps, shivering with ague, and bickering with hostile natives now associated with tropical and other expeditions. The stereoscopic camera with its scientific adjuncts will permit of almost automatic map-making, more comprehensive and accurate than any now attempted in other than the most settled sections. It is not too much to expect that arrangements will be perfected for conducting complete topographical surveys without more than occasional descents. If extremely high altitudes must be attained--over a mile--the machines will be of special design; but as far as can now be anticipated, there will be no insurmountable difficulties. The virgin peaks of Ruwenzori and the Himalayas may become easily accessible--even to women and children if they desire it. We may obtain direct evidence as to the contested ascent of Mt. McKinley. A report has been current that a Blériot monoplane has been purchased for use in the inspection of construction work for an oil pipe line across the Persian desert; the aeroplane being regarded as "more expeditious and effectual" than an automobile. The flying machine is the only land vehicle which requires no "permanent way." Trains must have rails, bicycles and automobiles must have good roads. Even the pedestrian gets along better on a path. The ships of the air and the sea demand no improvement of the fluids in which they float. To carry mails, parcels, persons, and even light freight--these applications, if made commercially practicable tomorrow,[D] would surprise no one; their possibility has already been amply demonstrated. With the dirigible as the transatlantic liner and the aeroplane as the naphtha launch of the air, the whole range of applications is commanded. Hangars and landing stages--the latter perhaps on the roofs of buildings, revolutionizing our domestic architecture--may spring up as rapidly as garages have done. And the aeroplane is potentially (with the exception of the motorcycle) the cheapest of self-propelled vehicles. Governments have already considered the possibilities of aerial smuggling. Perhaps our custom-house officers will soon have to watch a fence instead of a line: to barricade in two dimensions instead of one. They will need to be provided with United States Revenue aeroplanes. But how are aerial frontiers to be marked? And does a nation own the air above it, or is this, like the high seas, "by natural right, common to all"? Can a flying-machine blockade-runner above the three-mile height claim extraterritoriality? The flying machine is no longer the delusion of the "crank," because it has developed a great industry. A now antiquated statement put the capitalization of aeroplane manufactories in France at a million dollars, and the development expenditure to date at six millions. There are dozens of builders, in New York City alone, of monoplanes, biplanes, gliders, and models. A permanent exhibition of air craft is just being inaugurated. We have now even an aeronautic "trust," since the million-dollar capitalization of the Maxim, Blériot, Grahame-White firm. According to the New York _Sun_, over $500,000 has been subscribed for aviation prizes in 1911. The most valuable prizes are for new records in cross-country flights. The Paris _Journal_ has offered $70,000 for the best speed in a circling race from Paris to Berlin, Brussels, London, and back to Paris--1500 miles. Supplementary prizes from other sources have increased the total stake in this race to $100,000. A purse of $50,000 is offered by the London _Daily Mail_ for the "Circuit of Britain" race, from London up the east coast to Edinburgh, across to Glasgow, and home by way of the west coast, Exeter, and the Isle of Wight; a thousand miles, to be completed in two weeks, beginning July 22, with descents only at predetermined points. This contest will be open (at an entrance fee of $500) to any licensee of the International Federation. A German circuit, from Berlin to Bremen, Magdeburg, Düsseldorf, Aix-la-Chapelle, Dresden, and back to the starting point, is proposed by the _Zeitung am Mittag_ of Berlin, a prize of $25,000 having been offered. In this country, a comparatively small prize has been established for a run from San Francisco to New York, _via_ Chicago. Besides a meet at Bridgeport, May 18-20, together with those to be held by several of the colleges and the ones at Bennings and Chicago, there will be, it is still hoped, a national tournament at Belmont Park at the end of the same month. Here probably a dozen aviators will contest in qualification for the international meet in England, to which three American representatives should be sent as competitors for the championship trophy now held by Mr. Grahame-White. It is anticipated that the chances in the international races favor the French aviators, some of whom--in particular, Leblanc--have been making sensational records at Pau. Flights between aviation fields in different cities are the leading feature in the American program for the year. A trip is proposed from Washington to Belmont Park, _via_ Atlantic City, the New Jersey coast, and lower New York bay. The distance is 250 miles and the time will probably be less than that of the best passenger trains between Washington and New York. If held, this race will probably take place late in May. It is wisely concluded that the advancement of aviation depends upon cross-country runs under good control and at reasonable speeds and heights rather than upon exhibition flights in enclosures. It is to be hoped that commercial interests will not be sufficiently powerful to hinder this development. We shall of course have the usual international championship balloon race, preceded by elimination contests. From present indications Omaha is likely to be chosen as the point of departure. The need for scientific study of aerial problems is recognized. The sum of $350,000 has been offered the University of Paris to found an aeronautic institute. In Germany, the university at Göttingen has for years maintained an aerodynamic laboratory. Lord Rayleigh, in England, is at the head of a committee of ten eminent scientists and engineers which has, under the authority of Parliament, prepared a program of necessary theoretical and experimental investigations in aerostatics and aerodynamics. Our American colleges have organized student aviation societies and in some of them systematic instruction is given in the principles underlying the art. A permanent aeronautic laboratory, to be located at Washington, D.C., is being promoted. Aviation as a sport is under the control of the International Aeronautic Federation, having its headquarters at Paris. Bodies like the Royal Aero Club of England and the Aero Club of America are subsidiaries to the Federation. In addition, we have in this country other clubs, like the Aeronautic Society, the United States Aeronautical Reserve, etc. The National Council of the Aero Clubs of America is a sort of supreme court for all of these, having control of meets and contests; but it has no affiliation with the International body, which is represented here by the Aero Club of America. The Canadian Auto and Aero Club supervises aviation in the Dominion. Aviation has developed new legal problems: problems of liability for accidents to others; the matter of supervision of airship operators. Bills to license and regulate air craft have been introduced in at least two state legislatures. Schools for instruction in flying as an art or sport are being promoted. It is understood that the Wright firm is prepared to organize classes of about a dozen men, supplying an aeroplane for their instruction. Each man pays a small fee, which is remitted should he afterward purchase a machine. Mr. Grahame-White, at Pau, in the south of France, conducts a school of aviation, and the arrangements are now being duplicated in England. Instruction is given on Blériot monoplanes and Farman biplanes, at a cost of a hundred guineas for either. The pupil is coached until he can make a three-mile flight; meanwhile, he is held partially responsible for damage and is required to take out a "third-party" insurance policy. There is no lack of aeronautic literature. Major Squier's paper in the _Transactions_ of the American Society of Mechanical Engineers, 1908, gave an eighteen-page list of books and magazine articles of fair completeness up to its date; Professor Chatley's book, _Aeroplanes_, 1911, discusses some recent publications; the Brooklyn Public Library in New York issued in 1910 (misdated 1909) a manual of fourteen pages critically referring to the then available literature, and itself containing a list of some dozen bibliographies. Aerial Warfare [Illustration: THE GERMAN EMPEROR WATCHING THE PROGRESS OF AVIATION] The use of air craft as military auxiliaries is not new. As early as 1812 the Russians, before retreating from Moscow, attempted to drop bombs from balloons: an attempt carried to success by Austrian engineers in 1849. Both contestants in our own War of Secession employed captive and drifting balloons. President Lincoln organized a regular aeronautic auxiliary staff in which one Lowe held the official rank of chief aeronaut. This same gentleman (who had accomplished a reconnaissance of 350 miles in eight hours in a 25,000 cubic foot drifting balloon) was subjected to adverse criticism on account of a weakness for making ascents while wearing the formal "Prince Albert" coat and silk hat! A portable gas-generating plant was employed by the Union army. We are told that General Stoneman, in 1862, directed artillery fire from a balloon, which was repeatedly fired at by the enemy, but not once hit. The Confederates were less amply equipped. Their balloon was a patchwork of silk skirts contributed (one doubts not, with patriotic alacrity) by the daughters of the Confederacy. It is not forgotten that communication between besieged Paris and the external world was kept up for some months during 1870-71 by balloons exclusively. Mail was carried on a truly commercial scale: pet animals and--the anticlimax is unintended--164 persons, including M. Gambetta, escaped in some sixty-five flights. Balloons were frequently employed in the Franco-Prussian contest; and they were seldom put _hors de combat_ by the enemy. During our war with Spain, aerial craft were employed in at least one instance, namely, at San Juan, Porto Rico, for reconnoitering entrenchments. Frequent ascents were made from Ladysmith, during the Boer war. The balloons were often fired at, but never badly damaged. Cronje's army was on one occasion located by the aid of a British scout-balloon. Artillery fire was frequently directed from aerial observations. Both sides employed balloons in the epic conflict between Russia and Japan. A declaration introduced at the second international peace conference at the Hague proposed to prohibit, for a limited period, the discharge of projectiles or explosives from flying machines of any sort. The United States was the only first-class power which endorsed the declaration. It does not appear likely, therefore, that international law will discountenance the employment of aerial craft in international disputes. The building of airships goes on with increasing eagerness. Last year the Italian chamber appropriated $5,000,000 for the construction and maintenance of flying machines. A press report dated February 4 stated that a German aeronaut had been spending some weeks at Panama, studying the air currents of the Canal Zone. No flying machine may in Germany approach more closely than within six miles of a fort, unless specially licensed. At the Krupp works in Essen there are being tested two new guns for shooting at aeroplanes and dirigibles. One is mounted on an armored motor truck. The other is a swivel-mounted gun on a flat-topped four-wheeled carriage. The United States battleship _Connecticut_ cost $9,000,000. It displaces 18,000 tons, uses 17,000 horse-power and 1000 men, and makes twenty miles an hour. An aeroplane of unusual size with nearly three times this speed, employing from one to three men with an engine of 100 horse-power, would weigh one ton and might cost $5000. A Dreadnought costs $16,000,000, complete, and may last--it is difficult to say, but few claim more than ten years. It depreciates, perhaps, at the rate of $2,000,000 a year. Aeroplanes built to standard designs in large quantities would cost certainly not over $1000 each. The ratio of cost is 16,000 to 1. Would the largest Dreadnought, exposed unaided to the attack of 16,000 flying machines, be in an entirely enviable situation? An aeroplane is a fragile and costly thing to hazard at one blow: but not more fragile or costly than a Whitehead torpedo. The aeroplane soldier takes tremendous risks; but perhaps not greater risks than those taken by the crew of a submarine. There is never any lack of daring men when daring is the thing needed. All experience goes to show that an object in the air is hard to hit. The flying machine is safer from attack where it works than it is on the ground. The aim necessary to impart a crippling blow to an aeroplane must be one of unprecedented accuracy. The dirigible balloon gives a larger mark, but could not be immediately crippled by almost any projectile. It could take a good pounding and still get away. Interesting speculations might be made as to the outcome of an aerial battle between the two types of craft. The aeroplane might have a sharp cutting beak with which to ram its more cumbersome adversary, but this would involve some risk to its own stability: and the balloon could easily escape by a quick ascent. It has been suggested that each dirigible would need an aeroplane escort force for its defense against ramming. Any collision between two opposing heavier-than-air machines could not, it would seem, be other than disastrous: but perhaps the dirigible could rescue the wrecks. Possibly gas-inflated life buoys might be attached to the individual combatants. In the French man[oe]uvers, a small aeroplane circled the dirigible with ease, flying not only around it, but in vertical circles over and under it. [Illustration: 7.5 CENTIMETER GERMAN AUTOMATIC GUN FOR ATTACKING AIRSHIPS (From Brewer's _Art of Aviation_)] The French war office has exploited both types of machine. In Germany, the dirigible has until recently received nearly all the attention of strategists: but the results of a recent aerial war game have apparently suggested a change in policy, and the Germans are now, without neglecting the balloon, actively developing its heavier-than-air competitor. England seems to be muddled as to its aerial policy, while the United States has been waiting and for the most part doing nothing. Now, however, the mobilizations in Texas have been associated with a considerable amount of aeroplane enthusiasm. A half-dozen machines, it is expected, will soon be housed in the aerodrome at San Antonio. Experiments are anticipated in the carrying of light ammunition and emergency supplies, and one of the promised man[oe]uvers is to be the locating of concealed bodies of troops by air scouts. Thirty army officers are to be detailed for aeroplane service this year; five training schools are to be established. If flying machines are relatively unsusceptible to attack, there is also some question as to their effectiveness _in_ attack. Rifles have been discharged from moving balloons with some degree of accuracy in aim; but long-range marksmanship with any but hand weapons involves the mastery of several difficult factors additional to those present in gunnery at sea. The recoil of guns might endanger stability; and it is difficult to estimate the possible effects of a powerful concussion, with its resulting surges of air, in the immediate vicinity of a delicately balanced aerial vessel. But aside from purely combative functions, air craft may be superlatively useful as messengers. To send despatches rapidly and without interference, or to carry a general 100 miles in as many minutes--these accomplishments would render impossible the romance of a "Sheridan's Ride," but might have a romance of their own. With the new sense added to human equipment by wireless communication, the results of observations may be signaled to friends over miles of distance without intervening permanent connections of however fragile a nature. Flying machines would seem to be the safest of scouts. They could pass over the enemy's country with as little direct danger--perhaps as unobserved--as a spy in disguise; yet their occupants would scarcely be subjected to the penalty accompanying discovery of a spy. They could easily study the movements of an opposing armed force: a study now frequently associated with great loss of life and hampering of effective handling of troops. They could watch for hostile fleets with relatively high effectiveness (under usual conditions), commanding distant approaches to a long coast line at slight cost. From their elevated position, they could most readily detect hostile submarines threatening their own naval fleet. Maximum effective reconnaissance in minimum time would be their chief characteristic: in fact, the high speeds might actually constitute an objection, if they interfered with thorough observation. But if air craft had been available at Santiago in 1898, Lieutenant Blue's expedition would have been unnecessary, and there would have been for no moment any doubt that Admiral Cervera's fleet was actually bottled up behind the Morro. No besieged fortress need any longer be deprived of communication with--or even some medical or other supplies from--its friends. Suppose that Napoleon had been provided with a flying machine at Elba--or even at St. Helena! The applications to rapid surveying of unknown ground that have been suggested as possible in civil life would be equally possible in time of war. Even if the scene of conflict were in an unmapped portion of the enemy's territory, the map could be quickly made, the location of temporary defenses and entrenchments ascertained, and the advantage of superior knowledge of the ground completely overcome prior to an engagement. The searchlight and the compass for true navigation on long flights over unknown country would be the indispensable aids in such applications. During the current mobilization of the United States Army at Texas, a dispatch was carried 21 miles on a map-and-compass flight, the round trip occupying less than two hours and being made without incident. The machine flew at a height of 1500 feet and was sighted several miles off. A dirigible balloon, it has been suggested, is comparatively safe while moving in the air, but is subjected to severe strains when anchored to the ground, if exposed. It must have either safe harbors of refuge or actual shelter buildings--dry docks, so to speak. In an enemy's country a ravine or even a deep railway cut might answer in an emergency, but the greatest reliance would have to be placed on quick return trips from a suitable base. The balloon would be, perhaps, a more effective weapon in defense than in attack. Major Squier regards a flying height of one mile as giving reasonable security against hostile projectiles in the daytime. A lower elevation would be sufficient at night. Given a suitable telephotographic apparatus, all necessary observations could easily be made from this altitude. Even in the enemy's territory, descent to the earth might be possible at night under reasonably favorable conditions. Two sizes of balloon would seem to be indicated: the scouting work described would be done by a small machine having the greatest possible radius of action. Frontiers would be no barrier to it. Sent from England in the night it could hover over a Kiel canal or an island of Heligoland at sunrise, there to observe in most leisurely fashion an enemy's mobilizations. [Illustration: GERMAN GUN FOR SHOOTING AT AEROPLANES (From Brewer's _Art of Aviation_)] At the London meeting of the Institute of Naval Architects, in April, 1911, the opinion was expressed that the only effective way of meeting attack from a flying machine at sea would be by a counter-attack from the same type of craft. The ship designers concluded that the aeroplane would no more limit the sizes of battleships than the torpedo has limited them. For the more serious work of fighting, larger balloons would be needed, with net carrying capacities perhaps upward from one ton. Such a machine could launch explosives and combustibles against the enemy's forts, dry docks, arsenals, magazines, and battleships. It could easily and completely destroy his railroads and bridges; perhaps even his capital itself, including the buildings housing his chief executive and war office staff. Nothing--it would seem--could effectually combat it save air craft of its own kind. The battles of the future may be battles of the air. There are of course difficulties in the way of dropping missiles of any great size from flying machines. Curtiss and others have shown that accuracy of aim is possible. Eight-pound shrapnel shells have been dropped from an aeroplane with measurably good effect, without upsetting the vessel; but at best the sudden liberation of a considerable weight will introduce stabilizing and controlling difficulties. The passengers who made junketing trips about Paris on the _Clément-Bayard_ complained that they were not allowed to throw even a chicken-bone overboard! But it does not seem too much to expect that these purely mechanical difficulties will be overcome by purely mechanical remedies. An automatic venting of a gas ballonet of just sufficient size to compensate for the weight of the dropped shell would answer in a balloon: a similar automatic change in propeller speed and angle of planes would suffice with the aeroplane. There is no doubt but that air craft may be made efficient agents of destruction on a colossal scale. [Illustration: SANTOS-DUMONT CIRCLING THE EIFFEL TOWER (From Walker's _Aerial Navigation_)] A Swedish engineer officer has invented an aerial torpedo, automatically propelled and balanced like an ordinary submarine torpedo. It is stated to have an effective radius of three miles while carrying two and one-half pounds of explosive at the speed of a bullet. One can see no reason why such torpedoes of the largest size are not entirely practicable: though much lower speeds than that stated should be sufficient. According to press reports, the Krupps have developed a non-recoiling torpedo, having a range exceeding 5000 yards. The percussion device is locked at the start, to prevent premature explosion: unlocking occurs only after a certain velocity has been attained. Major Squier apparently contends that the prohibition of offensive aerial operations is unfair, unless with it there goes the reciprocal provision that a war balloon shall not be fired at from below. Again, there seems to be no good reason why aerial mines dropped from above should be forbidden, while submarine mines--the most dangerous naval weapons--are allowed. Modern strategy aims to capture rather than to destroy: the man[oe]uvering of the enemy into untenable situations by the rapid mobilization of troops being the end of present-day highly organized staffs. Whether the dirigible (certainly not the aeroplane) will ever become an effective vehicle for transport of large bodies of troops cannot yet be foreseen. Differences in national temper and tradition, and the conflict of commercial enterprise, perhaps the very recentness of the growth of a spirit of national unity on the one hand, are rapidly bringing the two foremost powers of Europe into keen competition: a competition which is resulting in a bloodless revolution in England, necessitated by the financial requirements of its naval program. Germany, by its strategic geographical position, its dominating military organization, and the enforced frugality, resourcefulness, and efficiency of its people, possesses what must be regarded as the most invincible army in the world. Its avowed purpose is an equally invincible navy. Whether the Gibraltar-Power can keep its ascendancy may well be doubted. The one doubtful--and at the same time perhaps hopeful--factor lies in the possibilities of aerial navigation. [Illustration: LATHAM, FARMAN, AND PAULHAN] If one battleship, in terms of dollars, represents 16,000 airships, and if one or a dozen of the latter can destroy the former--a feat not perhaps beyond the bounds of possibility--if the fortress that represents the skill and labor of generations may be razed by twoscore men operating from aloft, then the nations may beat their spears into pruning-hooks and their swords into plowshares: then the battle ceases to hinge on the power of the purse. Let war be made so costly that nations can no more afford it than sane men can wrestle on the brink of a precipice. Let armed international strife be viewed as it really is--senseless as the now dying duello. Let the navy that represents the wealth, the best engineering, the highest courage and skill, of our age, be powerless at the attack of a swarm of trifling gnats like Gulliver bound by Lilliputians--what happens then? It is a _reductio ad absurdum_. Destructive war becomes so superlatively destructive as to destroy itself. There is only one other way. Let the two rival Powers on whom the peace of the world depends settle their difficulties--surely the earth must be big enough for both!--and then as one would gently but firmly take away from a small boy his too destructive toy rifle, spike the guns and scuttle the ships, their own and all the rest, leaving to some unambitious and neutral power the prosaic task of policing the world. Here is a work for red blood and national self-consciousness. If war were ever needed for man's best development, other things will answer now. The torn bodies and desolated homes of millions of men have paid the price demanded. No imaged hell can surpass the unnamed horrors that our fathers braved. "Enforced disarmament!" Why not? Force (and public opinion) have abolished private duels. Why not national duels as well? Civilization's control of savagery always begins with compulsion. For a generation, no first-class power has had home experience in a serious armed conflict. We should not willingly contemplate such experience now. We have too much to do in the world to fight. * * * * * The writer has felt some hesitancy in letting these words stand as the conclusion of a book on flying machines: but as with the old Roman who terminated every oration with a defiance of Carthage, the conviction prevails that no other question of the day is of comparable importance; and on a matter of overwhelming consequence like this no word can ever be out of place. The five chief powers spent for war purposes (officially, as Professor Johnson puts it, for the "preservation of peace") about $1,000,000,000 in the year 1908. In the worst period of the Napoleonic operations the French military and naval budget was less than $100,000,000 annually. Great Britain, on the present peace footing, is spending for armament more rapidly than from 1793 to 1815. The gigantic "War of the Spanish Succession" (which changed the map of Europe) cost England less than a present year's military expenditure. Since the types for these pages have been set, the promise of international peace has been distinctly strengthened. President Taft has suggested that as, first, questions of individual privilege, and, finally, even those of individual honor, have been by common consent submitted to adjudication, so also may those so-called "issues involving national honor" be disposed of without dishonor by international arbitration. Sir Edward Grey, who does not hesitate to say that increase of armaments may end in the destruction of civilization unless stopped by revolt of the masses against the increasing burdens of taxation, has electrified Europe by his reception of the Taft pronouncement. England and the United States rule one-third the inhabitants of the earth. It is true that a defensive alliance might be more advantageous to the former and disagreeably entangling to the latter; but a binding treaty of arbitration between these powers would nevertheless be a worthy climax to our present era. And if it led to alliance against a third nation which had refused to arbitrate (led--as Sir Edward Grey suggests--by the logic of events and not by subterranean device) would not such be the fitting and conclusive outcome? The Taft-Grey program--one would wish to call it that--has had all reputable endorsement; in England, no factional opposition may be expected. Our own jingoes are strangely silent. Mr. Dillon's fear that compulsory disarmament would militate against the weaker nations is offset by the hearty adherence of Denmark. A resolution in favor of the establishment of an international police force has passed the House of Commons by a heavy majority. It looks now as if we might hope before long to re-date our centuries. We have had Olympiads and Years of Rome, B.C. and A.D. Perhaps next the dream of thoughtful men may find its realization in the new (and, we may hope, English) prefix, Y.P.--Year of Peace. FOOTNOTES [A] According to press reports, temporary water ballast will be taken on during the daytime, to offset the ascensional effect of the hot sun on the envelope. [B] The contestants for the Ryan prize of $10,000 were Moisant, Count de Lesseps, and Grahame-White. Owing to bad weather, there was no general participation in the preliminary qualifying events, and some question exists as to whether such qualification was not tacitly waived; particularly in view of the fact that the prize was awarded to the technically unqualified competitor, Mr. Moisant, who made the fastest time. This award was challenged by Mr. Grahame-White, and upon review by the International Aeronautic Federation the prize was given to de Lesseps, the slowest of the contestants, Grahame-White being disqualified for having fouled a pylon at the start. This gentleman has again appealed the case, and a final decision cannot be expected before the meeting of the Federation in October, 1911. [C] The high wind velocities of the southern circumpolar regions may be an insurmountable obstacle in the Antarctic. Yet Mawson expects to take with him a 2-passenger monoplane having a 180-mile radius of action on the expedition proposed for this year. [D] It seems that tomorrow has come; for an aeroplane is being regularly used (according to a reported interview with Dr. Alexander Graham Bell) for carrying mails in India. Books on Aeronautics =FLYING MACHINES TO-DAY.= By WILLIAM D. ENNIS, M. E., Professor of Mechanical Engineering, Polytechnic Institute, Brooklyn. 12mo., cloth, 218 pp., 123 illustrations =$1.50 net= =CONTENTS=: THE DELIGHTS AND DANGERS OF FLYING--Dangers of Aviation--What it is Like to Fly. SOARING FLIGHT BY MAN--What Holds it Up. Lifting Power. Why so Many Sails. Steering. TURNING CORNERS--What Happens When Making a Turn. Lateral Stability. Wing Warping. Automatic Control. The Gyroscope. Wind Gusts. AIR AND THE WIND--Sailing Balloons. Field and Speed. GAS AND BALLAST--Buoyancy in Air. Ascending and Descending. The Ballonet. The Equilibrator. DIRIGIBLE BALLOONS AND OTHER KINDS--Shapes. Dimensions. Fabrics. Framing. Keeping the Keel Horizontal. Stability. Rudders and Planes. Arrangement and Accessories. Amateur Dirigibles. Fort Omaha Plant. Balloon Progress. QUESTION OF POWER--Resistance of Aeroplanes. Resistance of Dirigibles. Independent Speed and Timetable. Cost of Speed. Propeller. GETTING UP AND DOWN; MODELS AND GLIDERS; AEROPLANE DETAILS--Launching. Descending. Gliders. Models. Balancing. Weights. Miscellaneous. Things to Look After. SOME AEROPLANES--SOME ACCOMPLISHMENTS. THE POSSIBILITIES IN AVIATION--Case of the Dirigible. The Orthopter. The Helicopter. Composite Types. What is Promised. AERIAL WARFARE. =AERIAL FLIGHT. Vol. 1. Aerodynamics.= By F. W. LANCHESTER. 8vo., cloth, 438 pp., 162 illustrations =$6.00 net= =CONTENTS=: Fluid Resistance and Its Associated Phenomena. Viscosity and Skin Friction. The Hydrodynamics of Analytical Theory. Wing Form and Motion in the Periphery. The Aeroplane. The Normal Plane. The Inclined Aeroplane. The Economics of Flight. The Aerofoil. On Propulsion, the Screw Propeller, and the Power Expended in Flight. Experimental Aerodynamics. Glossary. Appendices. =Vol. II. Aerodonetics.= By F. W. LANCHESTER. 8vo., cloth, 433 pp., 208 illustrations =$6.00 net= =CONTENTS=: Free Flight. General Principles and Phenomena. The Phugoid Theory--The Equations of the Flight Path. The Phugoid 1852-1872. Dirigible Balloons from 1883-1897; 1898-1906. Flying Machine Theory--The Flight Path Plotted. Elementary Deductions from the Phugoid Theory. Stability of the Flight Path as Affected by Resistance and Moment of Inertia. Experimental Evidence and Verification of the Phugoid Theory. Lateral and Directional Stability. Review of Chapters I to VII and General Conclusions. Soaring. Experimental. Aerodonetics. =AERIAL NAVIGATION. A practical handbook on the construction of dirigible balloons, aerostats, aeroplanes and aeromotors=, by FREDERICK WALKER. 12mo., cloth, 151 pp., 100 illustrations =$3.00 net.= =CONTENTS=: Laws of Flight. Aerostatics. Aerostats. Aerodynamics. Screw Propulsion. Paddles and Aeroplanes. Motive Power. Structure of Airships and Materials. Airships. Appendix. =AEROPLANE PATENTS.= By ROBERT M. NEILSON. 8vo., cloth, 101 pp., 77 illustrations =$2.00 net= =CONTENTS=: Advice to Inventors. Review of British Patents. British Patents and Applications for Patents from 1860 to 1910, arranged in Order of Application. British Patentees, arranged alphabetically. United States Patents from 1896 to 1909, arranged in order of issue. United States Patentees, arranged alphabetically. =THE PRINCIPLES OF AEROPLANE CONSTRUCTION.= By RANKIN KENNEDY, C. E. 8vo., cloth, 145 pp., 51 diagrams =$1.50 net= =CONTENTS=: Elementary Mechanics and Physics. Principles of Inclined Planes. Air and Its Properties. Principles of the Aeroplane. The Curves of the Aeroplane. Centers of Gravity: Balancing; Steering. The Propeller. The Hélicoptère. The Wing Propeller. The Engine. The Future of the Aeroplane. =HOW TO DESIGN AN AEROPLANE.= By HERBERT CHATLEY. 16mo., boards, 109 pp., illustrated (Van Nostrand's Science Series) =50 cents= =CONTENTS=: The Aeroplane. Air Pressure. Weight. Propellers and Motors. Balancing. Construction. Difficulties. Future Developments. Cost. Other Flying-Machines (Gyroplane and Orinthoptere). =HOW TO BUILD AN AEROPLANE.= By ROBERT PETIT. Translated from the French by T. O'B. Hubbard and J. H. Ledeboer. 8vo., cloth, 131 pp., 93 illustrations =$1.50 net= =CONTENTS=: General Principles of Aeroplane Design. Theory and Calculation. Resistance, Lift, Power, Calculations for the Design of an Aeroplane, Application of Power, Design of Propeller, Arrangements of Surfaces, Stability, Center of Gravity, etc. Materials. Construction of Propellers. Arrangements for Starting and Landing. Controls. Placing Motor. The Planes. Curvatures. Motors. =AIRSHIPS, PAST AND PRESENT. Together with chapters on the use of balloons in connection with meteorology, photography, and the carrier pigeon.= By A. HILDEBRANDT, Captain and Instructor in the Prussian Balloon Corps. Translated by W. H. Story. 8vo., cloth, 361 pp., 222 illustrations =$3.50 net= =CONTENTS=: Early History of the Art. Invention of the Air Balloon. Montgolfieres, Charlieres, and Rozieres. Theory of the Balloon. Development of the Dirigible Balloon. History of the Dirigible Balloon, 1852-1872. Dirigible Balloons from 1883-1897; 1898-1906. Flying Machines. Kites. Parachutes. Development of Military Ballooning. Ballooning in Franco-Prussian War. Modern Organization of Military Ballooning in France, Germany, England and Russia. Military Ballooning in Other Countries. Balloon Construction and the Preparation of the Gas. Instruments. Ballooning as a Sport. Scientific Ballooning. Balloon Photography. Photographic Outfit for Balloon Work. Interpretation of Photographs. Hectography by Means of Kites and Rockets. Carrier Pigeons for Balloons. Balloon Law. [Illustration: VAN NOSTRAND LOGO] D. VAN NOSTRAND CO., Publishers 23 MURRAY and 27 WARREN STREETS, NEW YORK Transcriber's Note: Italics are delimited by underscores; bold by equal signs. Four occurrences of the oe-ligature in the word man[oe]uver are left as [oe]. The four footnotes have been moved to the end of the book. A few words were judged to be printer errors and were changed. These include two occurrences of horse-power in the unhyphenated form, the spelling of Tabuteau as Tabuteaw on p. 162, and the spelling of hélicoptère as helicoptéré on p.208. On a few of the figure captions, missing accents were added to some French names. 
44466	----	https://archive.org/details/firstmancarrying00zahm THE FIRST MAN-CARRYING AEROPLANE CAPABLE OF SUSTAINED FREE FLIGHT: LANGLEY'S SUCCESS AS A PIONEER IN AVIATION by A. F. ZAHM, Ph. D. From the Smithsonian Report for 1914, pages 217-222 (WITH 8 PLATES) [Illustration] (Publication 2329) Washington Government Printing Office 1915 THE FIRST MAN-CARRYING AEROPLANE CAPABLE OF SUSTAINED FREE FLIGHT--LANGLEY'S SUCCESS AS A PIONEER IN AVIATION. By A. F. ZAHM, Ph. D. [With 8 plates.] It is doubtful whether any person of the present generation will be able to appraise correctly the contributions thus far made to the development of the practical flying machine. The aeroplane as it stands to-day is the creation not of any one man, but rather of three generations of men. It was the invention of the nineteenth century; it will be the fruition, if not the perfection, of the twentieth century. During the long decades succeeding the time of Sir George Cayley, builder of aerial gliders and sagacious exponent of the laws of flight, continuous progress has been made in every department of theoretical and practical aviation--progress in accumulating the data of aeromechanics, in discovering the principles of this science, in improving the instruments of aerotechnic research, in devising the organs and perfecting the structural details of the present-day dynamic flying machine. From time to time numerous aerial craftsmen have flourished in the world's eye, only to pass presently into comparative obscurity, while others too neglected or too poorly appreciated in their own day subsequently have risen to high estimation and permanent honor in the minds of men. Something of this latter fortune was fated to the late Secretary of the Smithsonian Institution. For a decade and a half Dr. Langley had toiled unremittingly to build up the basic science of mechanical flight, and finally to apply it to practical use. He had made numerous model aeroplanes propelled by various agencies--by India rubber, by steam, by gasoline--all operative and inherently stable. Then with great confidence he had constructed for the War Department a man flier which was the duplicate, on a fourfold scale, of his successful gasoline model. But on that luckless day in December, 1903, when he expected to inaugurate the era of substantial aviation, an untoward accident to his launching gear badly crippled his carefully and adequately designed machine. The aeroplane was repaired, but not again tested until the spring of 1914--seven years after Langley's death. Such an accident, occurring now, would be regarded as a passing mishap; but at that time it seemed to most people to demonstrate the futility of all aviation experiments. The press overwhelmed the inventor with ridicule; the great scientist himself referred to the accident as having frustrated the best work of his life. Although he felt confident of the final success of his experiments, further financial support was not granted and he was forced to suspend operations. Scarcely could he anticipate that a decade later, in a far away little hamlet, workmen who had never known him would with keenest enthusiasm rehabilitate that same tandem monoplane, and launch it again and again in successful flight, and that afterwards in the National Capital it should be assigned the place of honor among the pioneer vehicles of the air. When in March, 1914, Mr. Glenn H. Curtiss was invited to send a flying boat to Washington to participate in celebrating "Langley Day,"[1] he replied, "I would like to put the Langley aeroplane itself in the air." Learning of this remark Secretary Walcott, of the Smithsonian Institution, soon authorized Mr. Curtiss to recanvas the original Langley aeroplane and launch it either under its own propulsive power or with a more recent engine and propeller. Early in April, therefore, the machine was taken from the Langley Laboratory and shipped in a box car to the Curtiss Aviation Field, beside Lake Keuka, Hammondsport, N. Y. In the following month it was ready for its first trial since the unfortunate accident of 1903. [1] May 6, the anniversary of the famous flight of Langley's steam model aeroplane in 1896, is known in Washington as "Langley Day," and has been celebrated with aerial maneuvers over land and water. The main objects of these renewed trials were, first, to show whether the original Langley machine was capable of sustained free flight with a pilot, and, secondly, to determine more fully the advantages of the tandem type of aeroplane. The work seemed a proper part of the general program of experiments planned for the recently reopened Langley Aerodynamical Laboratory. It was, indeed, for just such experimentation that the aeroplane had been given to the Smithsonian Institution by the War Department, at whose expense it had been developed and brought to completion prior to 1903. After some successful flights at Hammondsport the famous craft could, at the discretion of the Smithsonian Institution, either be preserved for exhibition or used for further scientific study. To achieve the two main objects above mentioned, the aeroplane would first be flown as nearly as possible in its original condition, then with such modifications as might seem desirable for technical or other reasons. Various ways of launching were considered. In 1903 the Langley aeroplane was launched from the top of a houseboat. A car supporting it and drawn by lengthy spiral springs ran swiftly along a track, then suddenly dropped away, leaving the craft afloat in midair with its propellers whirring and its pilot supplementing, with manual control, if need be, the automatic stability of the machine. This method of launching, as shown by subsequent experimentalists, is a practical one and was favorably entertained by Mr. Curtiss. He also thought of starting from the ground with wheels, from the ice with skates, from the water with floats. Having at hand neither a first rate smooth field nor a sheet of ice, he chose to start from the water. [Illustration: Smithsonian Report, 1914.--Zahm. PLATE 1. LANGLEY AEROPLANE (BUILT 1898-1903) READY FOR LAUNCHING AT HAMMONDSPORT, N. Y., MAY 28, 1914.] [Illustration: Smithsonian Report, 1914.--Zahm. PLATE 2. LANGLEY AEROPLANE JUST RISING FROM WATER, JUNE 2, 1914, PILOTED BY CURTISS.] [Illustration: FLIGHT OF LANGLEY AEROPLANE WITH ITS OWN POWER PLANT OVER LAKE KEUKA, JUNE 2, 1914, PILOTED BY CURTISS.] [Illustration: Smithsonian Report, 1914.--Zahm. PLATE 3. CURTISS 80-HORSEPOWER MOTOR AND TRACTOR SCREW MOUNTED ON LANGLEY AEROPLANE.] [Illustration: Smithsonian Report, 1914.--Zahm. PLATE 4. ELWOOD DOHERTY CLEARING THE WATER SEPTEMBER 17, 1914, IN THE LANGLEY AEROPLANE DRIVEN BY A CURTISS 80-HORSEPOWER MOTOR AND TRACTOR SCREW.] In the accompanying illustrations, plates 1 and 2 show the appearance of the Langley flying machine after Mr. Curtiss had provided it with hydroaeroplane floats and their connecting truss work. The steel main frame, the wings, the rudders, the engine and propellers all were substantially as they had been in 1903. The pilot had the same seat under the main frame, and the same general system of control as in 1903. He could raise or lower the craft by moving the big rear rudder up and down; he could steer right and left by turning the vertical rudder. He had no ailerons nor wing-warping mechanism, but for lateral balance depended upon the dihedral angle of the wings and upon suitable movements of his weight or of the vertical rudder. And here it may be noted that Langley had placed the vertical steering rudder under and to the rear of the center of gravity. So placed, it served as a fairly good aileron by exerting a turning movement about the longitudinal axis of the machine. After the adjustments for actual flight had been made in the Curtiss factory, according to the minute descriptions contained in the Langley Memoir on Mechanical Flight, the aeroplane was taken to the shore of Lake Keuka, beside the Curtiss hangars, and assembled for launching. On a clear morning (May 28), and in a mild breeze, the craft was lifted onto the water by a dozen men and set going, with Mr. Curtiss at the steering wheel, ensconced in the little boat-shaped car under the forward part of the frame. Many eager witnesses and camera men were at hand, on shore and in boats. The four-winged craft, pointed somewhat across the wind, went skimming over the wavelets, then automatically headed into the wind, rose in level poise, soared gracefully for 150 feet, and landed softly on the water near the shore. Mr. Curtiss asserted that he could have flown farther, but, being unused to the machine, imagined the left wings had more resistance than the right. The truth is that the aeroplane was perfectly balanced in wing resistance, but turned on the water like a weather vane owing to the lateral pressure on its big rear rudder. Hence in future experiments this rudder was made turnable about a vertical axis, as well as about the horizontal axis used by Langley. Henceforth the little vertical rudder under the frame was kept fixed and inactive. After a few more flights with the Langley aeroplane, kept as nearly as possible in its original condition, its engine and twin propellers were replaced by a Curtiss 80-horse motor and direct-connected tractor propeller mounted on the steel frame, well forward, as shown in the photographs. It was hoped in this way to spare the original engine and propeller bearings, which were none too strong for the unusual burden added by the floats. In 1903 the total weight of pilot and machine had been 830 pounds; with the floats lately added it was 1,170 pounds; with the Curtiss motor and all ready for flight it was 1,520 pounds. But notwithstanding these surplus additions of 40 per cent and 85 per cent above the original weight of the craft, the delicate wing spars and ribs were not broken, nor was any part of the machine excessively overstrained. Owing to the pressure of other work at the factory, the aeroplane equipped with the Curtiss motor was not ready for further flights till September. In the absence of Mr. Curtiss, who had gone to California in August, a pupil of his aviation school, Mr. Elwood Doherty, volunteered to act as pilot. During some trials for adjusting the aeroplane controls and the center of gravity, Mr. Doherty, on the afternoon of September 17, planed easily over the water, rose on level wing, and flew about 450 feet, at an elevation of 2 or 3 yards, as shown by the accompanying photographs of that date. Presently two other like flights were made. Mr. Doherty found that with the forewings at 10° incidence, the rear ones at 12°, and the pilot's seat on the main frame about midway between the wings, the flier responded nicely to the movements of the pilot wheel. A slight turn of the wheel steered the craft easily to right or left, a slight pull or push raised or lowered it. The big double tail, or rudder, which responded to these movements, was the only steering or control surface used. The breaking of the 8-foot tractor screw terminated these trials for the day. The waves indicate the strength of the wind during the flights. On September 19, using a 9-foot screw, Mr. Doherty began to make longer flights. A pleasant off-shore breeze rippled the water, but without raising whitecaps. A dozen workmen, lifting the great tandem monoplane from the shore, with the pilot in his seat, waded into the lake and set it gently on the water. A crowd of witnesses near at hand, and many scattered about the shores, and on the lofty vine-clad hills, stood watching expectantly. When some of the official observers and photographers, in a motor boat, were well out in the lake, a man in high-top boots, standing in the water, started the propeller, and stepped quickly out of the way. Then with its great yellow wings beautifully arched and distended, the imposing craft ran swiftly out from the shore, gleaming brilliantly in the afternoon sun. At first the floats and lower edges of the rudders broke the water to a white surge, then as the speed increased they rose more and more from the surface. Presently the rear floats and the rudders cleared the water, the front floats still skipping on their heels, white with foam. The whole craft was now in soaring poise. It quickly approached the photographers, bearing on its back the alert pilot, who seemed to be scrutinizing every part of it and well satisfied to let it race. Then it rose majestically and sailed on even wing 1,000 feet; sank softly, skimmed the water, and soared another 1,000 feet; grazed the water again, rose and sailed 3,000 feet; turned on the water and came back in the same manner; and, as it passed the photographers, soared again nearly half a mile. The flights were repeated a few minutes later, then, owing to squally weather, were discontinued for 11 days. [Illustration: Smithsonian Report, 1914.--Zahm. PLATE 5. FLIGHT OF LANGLEY AEROPLANE ABOVE LAKE KEUKA SEPTEMBER 17, 1914, PILOTED BY E. DOHERTY AND DRIVEN BY A CURTISS MOTOR AND TRACTOR SCREW.] [Illustration: Smithsonian Report, 1914.--Zahm. PLATE 6. LANGLEY AEROPLANE IN FLIGHT SEPTEMBER 19, 1914; CLIMBING.] [Illustration: Smithsonian Report, 1914.--Zahm. PLATE 7. LANGLEY AEROPLANE IN FLIGHT OCTOBER 1, 1914; NATURAL POISE.] [Illustration: Smithsonian Report, 1914.--Zahm. PLATE 8. LANGLEY AEROPLANE IN FLIGHT OCTOBER 1, 1914. HAMMONDSPORT, N. Y., IN BACKGROUND.] On October 1, 1914, the aeroplane was launched at 11 a. m. in an off-shore breeze strong enough to raise whitecaps. Hovering within 30 feet of the water, and without material loss of speed, it made in quick succession flights of the following duration, as observed by four of us in a motor boat and timed by myself: 20 seconds, 20 seconds, 65 seconds, 20 seconds, 40 seconds, 45 seconds. As the speed through air averaged about 50 feet per second, the through air lengths of these flights were, respectively, 1,000 feet, 1,000 feet, 3,250 feet, 1,000 feet, 2,000 feet, 2,250 feet. As the aeroplane was now well out from shore among the heavy billows and white caps, Mr. Doherty landed it upon the water and turned it half about for the homeward flight. Thereupon the propeller tips struck the waves and were broken off, one casting a splinter through the center of the left wing. The pilot stopped the engine, rested in his seat, and was towed home by our motor boat. The flights were witnessed and have been attested by many competent observers. As to the performance of the aeroplane during these trials, the pilot, Mr. E. Doherty, reports, and we observed, that the inherent lateral stability was excellent, the fore-and-aft control was satisfactory, and the movement of the craft both on the water and in the air was steady and suitable for practical flying in such weather. Apparently the machine could have flown much higher, and thus avoided touching the water during the lulls in the breeze; but higher flying did not seem advisable with the frail trussing of wings designed to carry 830 pounds instead of the 1,520 pounds actual weight. At the present writing the Langley aeroplane is in perfect condition and ready for any further tests that may be deemed useful. But it has already fulfilled the purpose for which it was designed. It has demonstrated that, with its original structure and power, it is capable of flying with a pilot and several hundred pounds of useful load. It is the first aeroplane in the history of the world of which this can be truthfully said. If the experiments be continued under more painstaking technical direction, longer flights can easily be accomplished. Mr. Manly, who designed the Langley engine and screws and who directed the construction and tests of the large aeroplane up to December 8, 1903, reports that he obtained from the propulsion plant a static thrust of 450 pounds, and that he once ran the engine under full load for 10 hours consecutively. This thrust is nearly 100 pounds more than that commonly obtained at Hammondsport with the same plant, and 20 pounds more than the static thrust obtained with the Curtiss motor on the day when it flew the aeroplane with 1,520 pounds aggregate weight. Hence, by restoring the engine and propellers to their original normal working condition they should be able to drive the aeroplane in successful flight with an aggregate weight of nearly 1,600 pounds, even when hampered with the floats and their sustaining truss work. With a thrust of 450 pounds, the Langley aeroplane, without floats, restored to its original condition and provided with stronger bearings, should be able to carry a man and sufficient supplies for a voyage lasting practically the whole day. Dr. Langley's aerotechnic work may be briefly summarized as follows: 1. His aerodynamic experiments, some published and some as yet unpublished, were complete enough to form a basis for practical pioneer aviation. 2. He built and launched, in 1896, the first steam model aeroplane capable of prolonged free flight, and possessing good inherent stability. 3. He built the first internal-combustion motor suitable for a practical man-carrying aeroplane. 4. He developed and successfully launched the first gasoline model aeroplane capable of sustained free flight. 5. He developed and built the first man-carrying aeroplane capable of sustained free flight. [Illustration] * * * * * * Transcriber's note: This e-text follows the text of the original publication. Some minor punctuation inconsistencies have been regularised. Small-capitals in the original publication have been changed to CAPITALS. 
43809	----	Benjamin Franklin and the First Balloons BY ABBOTT LAWRENCE ROTCH Reprinted from the Proceedings of the American Antiquarian Society Volume XVIII WORCESTER, MASSACHUSETTS THE DAVIS PRESS 1907 BENJAMIN FRANKLIN AND THE FIRST BALLOONS. BY ABBOTT LAWRENCE ROTCH. The recent bi-centenary of Franklin's birth, which coincided with the revival of interest in balloons, makes this a timely topic, especially since Franklin's descriptions of the first balloon ascensions are almost unknown and do not appear among his philosophical papers. The five letters which I have the honor to present were written to Sir Joseph Banks, President of the Royal Society of London, in 1783, when Franklin was Minister to the Court of France and, with the collateral documents, they give perhaps the most complete and accurate account of the beginning of aerial navigation, enlivened with the humor and speculation characteristic of the writer. It is certainly remarkable that Franklin, in the midst of diplomatic and social duties, could have found time to investigate personally this new invention of which he at once appreciated the possibilities. The documents which I publish are copies of Franklin's letters, made on thin paper in a copying press (probably the rotary machine invented by Franklin), and all but one bear his signature in ink. They have corrections in the author's hand-writing and, except for a few words, are quite legible. They were purchased by me from Dodd, Mead & Co., in December, 1905, and previously had belonged to G. M. Williamson, of Grandview-on-the-Hudson, to whom they had come from Vienna. None of the letters appear in Sparks' edition of Franklin's Works, and while all but one are included in the collections compiled by Bigelow and Smyth, there are numerous inaccuracies, some of which will be specified hereafter. Drafts of three of the letters are deposited in the University of Pennsylvania, but the existence of one letter and the whereabouts of another were unknown to the late Mr. Smyth, the editor of the last and most complete edition of Franklin's Works,[1] who made careful search for the original documents. Although the American owners of these copies did not allow them to be transcribed, Mr. Smyth states that he printed one letter from my copy, and he noted how the other copies differed from the drafts in the University of Pennsylvania. In general it may be said that, whereas Bigelow gives the text without paragraphs, capital letters or the old spelling,[2] Smyth follows the originals more closely. In view of the historic and scientific interest of these letters, they are now printed exactly according to the press-copies. The letter dated November 30, appears never to have been printed and whereas Smyth reproduced the letter of November 21 from the University of Pennsylvania draft, this or another draft (or possibly this copy) was in the possession of the French aeronaut, Gaston Tissandier, about 1887.[3] [1] The Writings of Benjamin Franklin, collected and edited by Albert Henry Smyth, Volume IX, New York, 1906. [2] Complete Works of Benjamin Franklin, compiled and edited by John Bigelow, Volume VIII, New York, 1888. [3] Histoire des Ballons, Paris, 1887, Volume I, page 29. (THE FIRST HYDROGEN BALLOON.) PASSY, Aug. 30, 1783. Sir, On Wednesday, the 27th Instant the new aerostatic Experiment, invented by Mess^rs. Montgolfier, of Annonay, was repeated by M. Charles, Professor of experimental Philosophy at Paris. A hollow Globe 12 feet Diameter was formed of what is called in England Oiled Silk, here _Taffetas gommé_, the Silk being impregnated with a Solution of Gum elastic in Lintseed Oil, as is said. The Parts were sewed together while wet with the Gum, and some of it was afterwards passed over the Seams, to render it as tight as possible. It was afterwards filled with the inflammable Air that is produced by pouring Oil of Vitriol upon Filings of Iron, when it was found to have a tendency upwards so strong as to be capable of lifting a Weight of 39 Pounds, exclusive of its own Weight which was 25 lbs. and the Weight of the Air contain'd. It was brought early in the morning to the _Champ de Mars_, a Field in which Reviews are sometimes made, lying between the Military School and the River. There it was held down by a Cord till 5 in the afternoon, when it was to be let loose. Care was taken before the Hour to replace what Portion had been lost, of the inflammable Air, or of its Force, by injecting more. It is supposed that not less than 50,000 People were assembled to see the Experiment. The Champ de Mars being surrounded by Multitudes, and vast Numbers on the opposite Side of the River. At 5 aClock Notice was given to the Spectators by the Firing of two Cannon, that the Cord was about to be cut. And presently the Globe was seen to rise, and that as fast as a Body of 12 feet Diameter, with a force only of 39 Pounds, could be suppos'd to move the resisting Air out of its Way. There was some Wind, but not very strong. A little Rain had wet it, so that it shone, and made an agreeable Appearance. It diminished in Apparent Magnitude as it rose, till it enter'd the Clouds, when it seem'd to me scarce bigger than an Orange, and soon after became invisible, the Clouds concealing it. The Multitude separated, all well satisfied and delighted with the Success of the Experiment, and amusing one another with discourses of the various uses it may possibly be apply'd to, among which many were very extravagant. But possibly it may pave the Way to some Discoveries in Natural Philosophy of which at present we have no Conception. A Note secur'd from the Weather had been affix'd to the Globe, signifying the Time & Place of its Departure, and praying those who might happen to find it, to send an account of its State to certain Persons at Paris. No News was heard of it till the next Day, when Information was receiv'd, that it fell a little after 6 aClock, at Gonesse, a Place about 4 Leagues Distance, and that it was rent open, and some say had Ice in it. It is suppos'd to have burst by the Elasticity of the contain'd Air when no longer compress'd by so heavy an Atmosphere. One of 38 feet Diameter is preparing by Mr. Montgolfier himself, at the Expence of the Academy, which is to go up in a few Days. I am told it is constructed of Linen & Paper, and is to be filled with a different Air, not yet made Public, but cheaper than that produc'd by the Oil of Vitriol, of which 200 Paris Pints were consum'd in filling the other. It is said that for some Days after its being filled, the Ball was found to lose an eighth Part of its Force of Levity in 24 Hours; Whether this was from Imperfection in the Tightness of the Ball, or a Change in the Nature of the Air, Experiments may easily discover. I thought it my Duty, Sir, to send an early Account of this extraordinary Fact, to the Society which does me the honour to reckon me among its Members; and I will endeavour to make it more perfect, as I receive farther Information. With great Respect, I am, Sir, Your most obedient and most humble Servant B. FRANKLIN SIR JOSEPH BANKS, Bar^t. P. S. Since writing the above, I am favour'd with your kind Letter of the 25th. I am much obliged to you for the Care you have taken to forward the Transactions, as well as to the Council for so readily ordering them on Application. Please to accept and present my Thanks. I just now learn, that some observers say, the Ball was 150 Seconds in rising, from the Cutting of the Cord till hid in the Clouds; that its height was then about 500 Toises, but, being moved out of the Perpendicular by the Wind, it had made a Slant so as to form a Triangle, whose Base on the Earth was about 200 Toises. It is said the Country People who saw it fall were frightned, conceiv'd from its bounding a little, when it touched the Ground, that there was some living Animal in it, and attack'd it with Stones and Knives, so that it was much mangled; but it is now brought to Town and will be repaired. The great one of M. Montgolfier, is to go up, as is said, from Versailles, in about 8 or 10 Days; It is not a Globe but of a different Form, more convenient for penetrating the Air. It contains 50,000 cubic Feet, and is supposed to have Force of Levity equal to 1500 pounds weight. A Philosopher here, M. Pilatre du Rozier has seriously apply'd to the Academy for leave to go up with it, in order to make some Experiments. He was complimented on his Zeal and Courage for the Promotion of Science, but advis'd to wait till the management of these Balls was made by Experience more certain & safe. They say the filling of it in M. Montgolfier's Way will not cost more than half a Crown. One is talk'd of to be 110 feet Diameter. Several Gentlemen have ordered small ones to be made for their Amusement. One has ordered four of 15 feet Diameter each; I know not with what Purpose; But such is the present Enthusiasm for promoting and improving this Discovery, that probably we shall soon make considerable Progress in the art of constructing and using the Machines. Among the Pleasanteries Conversation produces on this Subject, some suppose Flying to be now invented, and that since Men may be supported in the Air, nothing is wanted but some light handy Instruments to give and direct Motion. Some think Progressive Motion on the Earth may be advanc'd by it, and that a Running Footman or a Horse slung and suspended under such a Globe so as to have no more of Weight pressing the Earth with their Feet, than Perhaps 8 or 10 Pounds, might with a fair Wind run in a straight Line across Countries as fast as that Wind, and over Hedges, Ditches & even Waters. It has been even fancied that in time People will keep such Globes anchored in the Air, to which by Pullies they may draw up Game to be preserved in the Cool & Water to be frozen when Ice is wanted. And that to get Money, it will be contrived to give People an extensive View of the Country, by running them up in an Elbow Chair a Mile high for a Guinea &c. &c. B. F. (A HOT AIR BALLOON CARRYING ANIMALS.) PASSY, Oct. 8, 1783. Sir, The Publick were promised a printed particular Account of the Rise & Progress of the Balloon Invention, to be published about the End of last month. I waited for it to send it to you, expecting it would be more satisfactory than anything I could write; but it does not appear. We have only at present the enclosed Pamphlet, which does not answer the expectation given us. I send you with it some prints. That of the Balloon raised at Versailles is said to be an exact representation. I was not present, but am told it was filled in about ten minutes by means of burning Straw. Some say water was thrown into the flame, others that it was Spirits of Sal Volatile. It was supposed to have risen about 200 Toises: But did not continue long at that height, was carried horizontally by the Wind, and descended gently as the Air within grew cooler. So vast a Bulk when it began to rise so majestically in the Air struck the spectators with surprise and Admiration. The Basket contained a sheep, a duck, and a Cock, who, except the Cock, received no hurt by the fall. The Duke de Crillon made a feast last week in the Bois de Boulogne, just by my habitation, on occasion of the Birth of two Spanish Princes; after the Fireworks we had a Balloon of about 5 feet Diameter filled with permanent inflammable Air. It was dismissed about One aClock in the Morning. It carried under it a large Lanthorn with inscriptions on its sides. The Night was quite calm and clear, so that it went right up. The appearance of the light diminished gradually till it appeared no bigger than one of the Stars, and in about twenty minutes I lost sight of it entirely. It fell the next Day on the other side of the same Wood near the Village Boulogne, about half after twelve, having been suspended in the Air eleven hours and a half. It lodged in a tree, and was torn in getting it down; so that it cannot be ascertained whether it burst when above, or not, tho' that is supposed. Smaller Repetitions of the Experiment are making every day in all quarters. Some of the larger Balloons that have been up are preparing to be sent up again in a few Days; but I do not hear of any material improvements yet made either in the mechanical or Chemical parts of the Operation. Most is expected from the new one undertaken upon subscription by Messieurs Charles and Robert, who are Men of Science and mechanic Dexterity. It is to carry up a Man. I send you enclosed the Proposals, which it is said are already subscribed to by a considerable number and likely to be carried into execution. If I am well at the Time, I purpose to be present, being a subscriber myself, and shall send you an exact Account of Particulars. With great esteem and respect, for yourself and the Society; I have the honour to be, Sir, Your most obedient & most humble Servant, B. FRANKLIN SIR JOSEPH BANKS, Bar^t. (THE FIRST AERIAL VOYAGE BY MAN.) PASSY, Nov^r 21st, 1783 Dear Sir, I received your friendly Letter of the 7th Inst. I am glad my Letters respecting the Aerostatic Experiment were not unacceptable. But as more perfect Accounts of the Construction and Management of that Machine have been and will be published before your Transactions, and from which Extracts may be made that will be more particular and therefore more satisfactory, I think it best not to print those Letters. I say this in answer to your Question; for I did not indeed write them with a view of their being inserted. Mr. Faujas de St. Fond acquainted me yesterday that a Book on the Subject which has been long expected, will be publish'd in a few Days, and I shall send you one of them. Enclosed is a Copy of the _Procès verbal_ taken of the Experiment made yesterday in the Garden of the Queen's Palace la Muette where the Dauphin now resides which being near my House I was present. This Paper was drawn up hastily, and may in some Places appear to you obscure; therefore I shall add a few explanatory Observations. This Balloon was larger than that which went up from Versailles and carried the Sheep, &c. Its bottom was open, and in the middle of the Opening was fixed a kind of Basket Grate in which Faggots and Sheaves of Straw were burnt. The Air rarified in passing thro' this Flame rose in the Balloon, swell'd out its sides, and fill'd it. The Persons who were plac'd in the Gallery made of Wicker, and attached to the Outside near the Bottom, had each of them a Port thro' which they could pass Sheaves of Straw into the Grate to keep up the Flame, & thereby keep the Balloon full. When it went over our Heads, we could see the Fire which was very considerable. As the Flame slackens, the rarified Air cools and condenses, the Bulk of the Balloon diminishes and it begins to descend. If those in the Gallery see it likely to descend in an improper Place, they can by throwing on more Straw, & renewing the Flame, make it rise again, and the Wind carries it farther. _La Machine poussée par le Vent s'est dirigée sur une des Allées du Jardin._ That is against the Trees of one of the Walks. The Gallery hitched among the top Boughs of those Trees which had been cut and were stiff while the Body of the Balloon lean'd beyond and seemed likely to overset. I was then in great Pain for the Men, thinking them in danger of being thrown out, or burnt for I expected that the Balloon being no longer upright the Flame would have laid hold of the inside that leaned over it. But by means of some Cords that were still attach'd to it, it was soon brought upright again, made to descend, & carried back to its place. It was however much damaged. _Planant sur l'Horizon._ When they were as high as they chose to be, they made less Flame and suffered the Machine to drive Horizontally with the Wind, of which however they felt very little, as they went with it, and as fast. They say they had a charming View of Paris & its Environs, the Course of the River, &c but that they were once lost, not knowing what Part they were over, till they saw the Dome of the Invalids, which rectified their Ideas. Probably while they were employed in keeping up the Fire, the Machine might turn, and by that means they were _desorientés_ as the French call it. There was a vast Concourse of Gentry in the Garden, who had great Pleasure in seeing the Adventurers go off so chearfully, & applauded them by clapping &c. but there was at the same time a good deal of Anxiety for their Safety. Multitudes in Paris saw the Balloon passing; but did not know there were Men with it, it being then so high that they could not see them. _Développant du Gaz._ That is, in plain English, _burning more straw_; for tho' there is a little Mystery made, concerning the kind of Air with which the Balloon is filled, I conceive it to be nothing more than hot Smoke or common Air rarify'd, tho' in this I may be mistaken. _Aiant encor dans leur Galerie les deux tiers de leur Approvisionement._ That is their Provision of Straw; of which they carried up a great Quantity. It was well that in the hurry of so hazardous an Experiment, the Flame did not happen by any accidental Mismanagement to lay hold of this Straw; tho' each had a Bucket of Water by him, by Way of Precaution. One of these courageous Philosophers, the Marquis d'Arlandes, did me the honour to call upon me in the Evening after the Experiment, with Mr. Montgolfier the very ingenious Inventor. I was happy to see him safe. He informed me that they lit gently without the least Shock, and the Balloon was very little damaged. This Method of filling the Balloon with hot Air is cheap and expeditious, and it is supposed may be sufficient for certain purposes, such as elevating an Engineer to take a View of an Enemy's Army, Works, &c. conveying Intelligence into, or out of a besieged Town, giving Signals to distant Places, or the like. The other Method of filling a Balloon with permanently elastic inflammable Air, and then closing it is a tedious Operation, and very expensive; Yet we are to have one of that kind sent up in a few Days. It is a Globe of 26 feet diameter. The Gores that compose it are red and white Silk, so that it makes a beautiful appearance. A very handsome triumphal Car will be suspended to it, in which Mess^rs. Robert, two Brothers, very ingenious Men, who have made it in concert with Mr. Charles propose to go up. There is room in this Car for a little Table to be placed between them, on which they can write and keep their Journal, that is take Notes of every thing they observe, the State of their Thermometer, Barometer, Hygrometer, &c which they will have more Leisure to do than the others, having no fire to take Care of. They say they have a contrivance which will enable them to descend at Pleasure. I know not what it is. But the Expence of this Machine, Filling included, will exceed, it is said, 10,000 Livres. This Balloon of only 26 feet diameter being filled with Air ten times lighter than common Air, will carry up a greater Weight than the other, which tho' vastly bigger was filled with an Air that could scarcely be more than twice as light. Thus the great Bulk of one of these Machines, with the short duration of its Power, & the great Expence of filling the other will prevent the Inventions being of so much Use, as some may expect, till Chemistry can invent a cheaper light Air producible with more Expedition. But the Emulation between the two Parties running high, the Improvement in the Construction and Management of the Balloons has already made a rapid Progress; and one cannot say how far it may go. A few Months since the Idea of Witches riding thro' the Air upon a Broomstick, and that of Philosophers upon a Bag of Smoke, would have appeared equally impossible and ridiculous. These Machines must always be subject to be driven by the Winds. Perhaps Mechanic Art may find easy means to give them progressive Motion in a Calm, and to slant them a little in the Wind. I am sorry this Experiment is totally neglected in England where mechanic Genius is so strong. I wish I could see the same Emulation between the two Nations as I see between the two Parties here. Your Philosophy seems to be too bashful. In this Country we are not so much afraid of being laught at. If we do a foolish thing, we are the first to laugh at it ourselves, and are almost as much pleased with a _Bon Mot_ or a good _Chanson_, that ridicules well the Disappointment of a Project, as we might have been with its Success. It does not seem to me a good reason to decline prosecuting a new Experiment which apparently increases the Power of Man over Matter, till we can see to what Use that Power may be applied. When we have learnt to manage it, we may hope some time or other to find Uses for it, as Men have done for Magnetism and Electricity of which the first Experiments were mere Matters of Amusement. This Experience is by no means a trifling one. It may be attended with important Consequences that no one can foresee. We should not suffer Pride to prevent our progress in Science. Beings of a Rank and Nature far superior to ours have not disdained to amuse themselves with making and launching Balloons, otherwise we should never have enjoyed the Light of those glorious objects that rule our Day & Night, nor have had the Pleasure of riding round the Sun ourselves upon the Balloon we now inhabit. With great and sincere Esteem, I am, Dear Sir, Your most obed^t & most humble Servant, B. FRANKLIN Sir JOSEPH BANKS. (POSTPONEMENT OF CHARLES' AND ROBERT'S ASCENSION.) PASSY, Nov. 30, 1783 Dear Sir, I did myself the honour of writing to you the Beginning of last Week, and I sent you by the Courier, M. Faujas's Book upon the Balloons, which I hope you have receiv'd. I did hope to have given you to day an Account of Mr. Charles's grand Balloon, which was to have gone up yesterday; but the filling it with inflammable Air having taken more time than had been calculated, it is deferr'd till to-morrow. I send you herewith a Paper in which you will see what was proposed by Mess^rs Robert who constructed the Machine; and some other Papers relative to the same Subject, the last of which is curious, as containing the Journal of the first Aerial Voyage performed by Man.--I purpose being present to-morrow at the Experiment, and shall give you an Acc^t of it by the Wednesday's Post. With sincere & great Esteem, I have the honour to be, Sir, Your most obed^t humble Serv^t B. FRANKLIN Sir JOS. BANKS, Bar^t. (THE SECOND AERIAL VOYAGE BY MAN.) PASSY, Dec. 1, 1783. Dear Sir, In mine of yesterday, I promis'd to give you an Account of Mess^rs. Charles & Robert's Experiment, which was to have been made at this Day, and at which I intended to be present. Being a little indispos'd, & the Air cool, and the Ground damp, I declin'd going into the Garden of the Tuilleries where the Balloon was plac'd, not knowing how long I might be oblig'd to wait there before it was ready to depart; and chose to stay in my Carriage near the Statue of Louis XV. from whence I could well see it rise, & have an extensive View of the Region of Air thro' which, as the Wind sat, it was likely to pass. The Morning was foggy, but about one aClock, the Air became tolerably clear, to the great Satisfaction of the Spectators, who were infinite, Notice having been given of the intended Experiment several Days before in the Papers, so that all Paris was out, either about the Tuilleries, on the Quays & Bridges, in the Fields, the Streets, at the Windows, or on the Tops of Houses, besides the Inhabitants of all the Towns & Villages of the Environs. Never before was a philosophical Experiment so magnificently attended. Some Guns were fired to give Notice, that the Departure of the great Balloon was near, and a small one was discharg'd which went to an amazing Height, there being but little Wind to make it deviate from its perpendicular Course, and at length the Sight of it was lost. Means were used, I am told, to prevent the great Balloon's rising so high as might indanger its Bursting. Several Bags of Sand were taken on board before the Cord that held it down was cut, and the whole Weight being then too much to be lifted, such a Quantity was discharg'd as to permit its Rising slowly. Thus it would sooner arrive at that Region where it would be in Equilibrio with the surrounding Air, and by discharging more Sand afterwards, it might go higher if desired. Between One & Two aClock, all Eyes were gratified with seeing it rise majestically from among the Trees, and ascend gradually above the Buildings, a most beautiful Spectacle! When it was about 200 feet high, the brave Adventurers held out and wav'd a little white Pennant, on both Sides their Car, to salute the Spectators, who return'd loud Claps of Applause. The Wind was very little, so that the Object, tho' moving to the Northward, continued long in View; and it was a great while before the admiring People began to disperse. The Persons embark'd were Mr. Charles, Professor of Experimental Philosophy, & a zealous Promoter of that Science; and one of the Messieurs Robert, the very ingenious Constructors of the Machine. When it arrived at its height, which I suppose might be 3 or 400 Toises, it appeared to have only horizontal Motion. I had a Pocket Glass, with which I follow'd it, till I lost Sight, first of the Men, then of the Car, and when I last saw the Balloon, it appear'd no bigger than a Walnut. I write this at 7 in the Evening. What became of them is not yet known here. I hope they descended by Day-light, so as to see & avoid falling among Trees or on Houses, and that the Experiment was completed without any mischievous Accident which the Novelty of it & the want of Experience might well occasion. I am the more anxious for the Event, because I am not well inform'd of the Means provided for letting themselves gently down, and the Loss of these very ingenious Men would not only be a Discouragement to the Progress of the Art, but be a sensible Loss to Science and Society. I shall inclose one of the Tickets of Admission, on which the Globe was represented, as originally intended, but is altered by the Pen to show its real State when it went off. When the Tickets were engraved, the Car was to have been hung to the Neck of the Globe, as represented by a little Drawing I have made in the Corner A. I suppose it may have been an Apprehension of Danger in straining too much the Balloon or tearing the Silk, that induc'd the Constructors to throw a Net over it, fix'd to a Hoop which went round its Middle, and to hang the Car to that Hoop, as you see in Fig. B. Tuesday Morning, Dec. 2. I am reliev'd from my Anxiety, by hearing that the Adventurers descended well near l'Isle Adam, before Sunset. This Place is near 7 Leagues from Paris. Had the Wind blown fresh, they might have gone much farther. If I receive any farther Particulars of Importance I shall communicate them hereafter. With great Esteem, I am, Dear Sir, Your most obedient & most humble servant, B. FRANKLIN P. S. Tuesday Evening. Since writing the above, I have receiv'd the printed Paper & the Manuscript, containing some Particulars of the Experiment, which I enclose.--I hear farther, that the Travellers had perfect Command of their Carriage, descending as they pleas'd by letting some of the inflammable Air escape, and rising again by discharging some Sand; that they descended over a Field so low as to talk with Labourers in passing and mounted again to pass a Hill. The little Balloon falling at Vincennes, shows that mounting higher it met with a Current of Air in a contrary Direction: An Observation that may be of use to future aerial Voyagers. Sir JOSEPH BANKS, Bar^t. (SOME PARTICULARS OF THE SECOND VOYAGE.) Mr. Le Chevalier de Cubière qui a suivi la marche du Globe est arrivé chez M. Charles hier à 10 heures 1/4 du Soir et a dit, Que les Voyageurs étoient descendus lentement et volontairement à trois heures 3/4 dans les Marais de Nesle et d'Hebouville, une lieue et demie après l'Isle Adam. Ils y ont été accueillis par Mrs. le Duc de Chartre et Fitz James, qui après les avoir embrassés, ont signé le Procès verbal de lieu et d'heure. Beaucoup d'habitants de la campagne et le curé de Nesle et d'Hebouville se sont aussi trouvés à leur arrivée. Les Voyageurs ont assuré n'avoir éprouvé que des Sensations agréables dans leur traversée. Mr. Robert étant sorti du Char, et aidé de quelques Paysans, se disposoit à remplacer sa Pesanteur avec de la Terre; mais M. Charles voulant profiter du peu de Jour qui lui restoit, pour faire encore quelques observations, impatienté de la Lenteur de cette operation, a repris son Vol à 4 heures et 1/4, avec un excédant de Légèreté d'environ 100 Livres par une Ascension droite et une rapidité telle qu'en peu de tems le Globe s'est trouvé hors de vue. La Chute du Jour l'a déterminé à redescendre une lieue et 1/2 plus loin, aux environs de Fouroy. La Machine n'a éprouvé aucun Accident. Elle perdoit légèrement par une petite ouverture qui existoit dejà quelques heures avant son Depart auprès de l'appendice, et dont le Morceau de Taffetas que l'on y avoit appliqué au moment de l'expérience, s'étoit detaché. * * * * * Le petit Ballon est tombé dans la Cour du Dongeon à Vincennes. Il a été ramassé par des Enfans et vendu 6_d._ au nommé Bertrand. Il avoit perdu son air inflammable par le Robinet qu'on avoit laissé ouvert exprès pour empêcher l'explosion à trop grande hauteur. On évalue qu'il a été 50 minutes en l'air. Le Taffetas étoit roussi aux deux Extremités. NOTES CONCERNING THE LETTERS. _Letter of August 30._ The hand-writing is in a more flowing style than the subsequent letters. Bigelow omits paragraph ten beginning "It is said." Both Bigelow and Smyth give another paragraph in the Postscript, beyond the signature "B. F." in my copy; also a note dated Sept. 2^d, which contains calculations in French relating to the balloon. Smyth says that these additions are not in the University of Pennsylvania draft but that they occur in this press-copy, which is obviously a mistake. In paragraph two of the Postscript "mov'd out," in Smyth, should read "being moved out," and in the last line but one "upon" should read "up in." _Letter of October 8._ In the eighth line after the word "Balloon" Smyth inserts "lately." Part of the valedictory and the signature are omitted by Bigelow and Smyth, but the former gives an "Extract of the Proposals" for the balloon of which I have no copy. _Letter of November 21._ This should be dated Nov. 22, since the ascension of d'Arlandes and de Rozier which, according to the letter, took place the previous day is known to have been on the 21st. The orthography of the French words in Bigelow and Smyth does not always agree with the copy. In paragraph three, for "Post," in Smyth, read "Port;" in paragraph six for "Adventures," in Smyth, read "Adventurers;" in paragraph thirteen for "By the emulation," in Smyth, read "But the Emulation;" in paragraph fifteen for the phrase, in Smyth and Bigelow, beginning, "I wish I could see the same emulation," correct to end, "between the two Nations as I see between the two Parties here;" in paragraph sixteen, in both Bigelow and Smyth, for "Experiment," read "Experience;" and for the unintelligible phrase in both Bigelow and Smyth, "Beings of a frank and [sic] nature," read "Beings of a Rank and Nature." Minor discrepancies between this and the other press-copies and the letters as printed by Bigelow and Smyth also occur. The signature is in pencil in this copy. A "P. S. Nov. 25th" is not in the press-copy, contrary to Smyth's statement, but I have a press-copy of the French _Procès-Verbal_, therein referred to, in Franklin's handwriting with his name and eight others affixed as witnesses. Neither Bigelow nor Smyth print this document, which was first reproduced in the book mentioned by Franklin in the first paragraph of his letter, viz: "Description des Expériences de la Machine Aérostatique par M. Faujas de Saint-Fond, Paris, 1783." Since Franklin's copy of the _Procès-Verbal_ differs only in his spelling the word "_sang-froid_" instead of "_sens-froid_," I do not print it. However, other changes were introduced in the _Procès-Verbal_ when reprinted in the second volume of M. Faujas' work, published in 1784. The plate forming the frontispiece to this volume shows the balloon as seen from Mr. Franklin's terrace at Passy. _Letter of November 30._ This has never been published so far as I know. "The Journal of the first Aerial Voyage," here mentioned, was written by the Marquis d'Arlandes to M. Faujas de Saint-Fond on Nov. 28th and first printed in the _Journal de Paris_ but was republished by Faujas de Saint-Fond in his second volume. _Letter of December 1._ Smyth states that he reproduced this letter from my press-copy but he omits the capital letters and the contractions in spelling, as well as the references "A" and "B," which are given by Bigelow with the remark that the drawings were not found. "The Manuscript, containing some Particulars of the Experiment, which I enclose," mentioned in the Postscript, is a two-page account in French, in Franklin's handwriting, by an eye-witness of the voyage, M. le Chevalier de Cubière. As this interesting document has never been published, to my knowledge, I have given it here _literatim_ from my press-copy. --Transcriber's note-- A caret (^) indicates the following character or characters were printed in superscript. Some superscripts were silently converted to regular characters (i.e. 27th instead of 27^th). Except for the following corrections, the original text and punctuation remain unchanged: p. 7, Added a missing comma after "Sir" at the beginning of the letter "A hot air balloon carrying animals", as there is one in every other letter; p. 7, added missing "t" to "than" in "more satisfactory than anything"; p. 9, "Procés verbal" corrected to "Procès verbal"; p. 11, added a missing comma after "Robert" in "Mess^rs. Robert, two Brothers,"; p. 11, "Aiant encor dans leur Galerie le deux tiers de leur Approvissonement." was corrected to "... les deux tiers de leur Approvisionement." "Aiant encor" might be "Ayant encore", as printed in the "Journal des sçavans" of January 1784, but was not corrected here; p. 14, "Carr" corrected to "Car" in "on both Sides their Car,"; p. 16, removed a space after "d'" in "Beaucoup d'habitants"; p. 16, "Bart." corrected to "Bar^t." in "Sir JOSEPH BANKS, Bar^t."; p. 17, "Sept. 2d" corrected to "Sept. 2^d", for 2nd. The following possible mispellings have been retained: p. 6, "M. Pilatre du Rozier" should be "M. Pilâtre de Rozier"; p. 10, "chearfully" is possibly an older spelling for "cheerfully"; p. 16, there are several missing accents that might have been in the original French document, in "desorientés", "operation", "dejà", "depart", "detaché" and "extremités". There are two occurences of "&c" for "&c." 
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41135	----	[Illustration: THE MOST IMPORTANT "TOOL" IN THE BUILDING OF MODEL AEROPLANES. [_Illustration by permission from_ MESSRS. A. GALLENKAMP & CO'S. CHEMICAL CATALOGUE.]] THE THEORY AND PRACTICE OF MODEL AEROPLANING BY V.E. JOHNSON, M.A. AUTHOR OF 'THE BEST SHAPE FOR AN AIRSHIP,' 'SOARING FLIGHT,' 'HOW TO ADVANCE THE SCIENCE OF AERONAUTICS,' 'HOW TO BUILD A MODEL AEROPLANE,' ETC. "Model Aeroplaning is an Art in itself" [Illustration] London E. & F.N. SPON, LTD., 57 HAYMARKET New York SPON & CHAMBERLAIN, 123 LIBERTY STREET 1910 PREFACE The object of this little book is not to describe how to construct some particular kind of aeroplane; this has been done elsewhere: but to narrate in plain language the general practice and principles of model aeroplaning. There is a _science_ of model aeroplaning--just as there is a science of model yachting and model steam and electric traction, and an endeavour is made in the following pages to do in some measure for model aeroplanes what has already been done for model yachts and locomotives. To achieve the best results, theory and practice must go hand in hand. From a series of carefully conducted experiments empirical formulæ can be obtained which, combined later with mathematical induction and deduction, may lead, not only to a more accurate and generalized law than that contained in the empirical formula, but to valuable deductions of a totally new type, embodying some general law hitherto quite unknown by experimentalists, which in its turn may serve as a foundation or stepping stone for suggesting other experiments and empirical formulæ which may be of especial importance, to be treated in _their_ turn like their predecessor. By "especial importance," I mean not only to "model," but "Aeroplaning" generally. As to the value of experiments on or with models with respect to full-sized machines, fifteen years ago I held the opinion that they were a very doubtful factor. I have since considerably modified that view, and now consider that experiments with models--if properly carried out, and given due, not _undue_, weight--both can and will be of as much use to the science of Aeronautics as they have already proved themselves to be in that of marine engineering. The subject of model propellers and motors has been somewhat fully dealt with, as but little has been published (in book form, at any rate) on these all-important departments. On similar grounds the reasons why and how a model aeroplane flies have been practically omitted, because these have been dealt with more or less in every book on heavier-than-air machines. Great care has been exercised in the selection of matter, and in the various facts stated herein; in most cases I have personally verified them; great pains have also been exercised to exclude not only misleading, but also doubtful matter. I have no personal axe to grind whatever, nor am I connected either directly or indirectly with any firm of aeroplane builders, model or otherwise. The statements contained in these pages are absolutely free from bias of any kind, and for them I am prepared to accept full responsibility. I have to thank Messrs. A.W. GAMAGE (Holborn) for the use of various model parts for testing purposes, and also for the use of various electros from their modern Aviation Catalogue; also Messrs. T.W.K. CLARKE & CO., of Kingston-on-Thames. For the further use of electros, and for permission to reproduce illustrations which have previously appeared in their papers, I must express my acknowledgment and thanks to the publishers of the "Model Engineer," "Flight," and the "Aero." Corrections and suggestions of any kind will be gratefully received, and duly acknowledged. V.E. JOHNSON. CONTENTS INTRODUCTION. PAGE §§ 1-5. The two classes of models--First requisite of a model aeroplane. § 6. An art in itself. § 7. The leading principle 1 CHAPTER I. THE QUESTION OF WEIGHT. §§ 1-2. Its primary importance both in rubber and power-driven models--Professor Langley's experiences. § 3. Theoretical aspect of the question. § 4. Means whereby more weight can be carried--How to obtain maximum strength with minimum weight. § 5. Heavy models versus light ones 4 CHAPTER II. THE QUESTION OF RESISTANCE. § 1. The chief function of a model in the medium in which it travels. § 2. Resistance considered as load percentage. § 3. How made up. § 4. The shape of minimum resistance. § 5. The case of rubber-driven models. § 6. The aerofoil surface--Shape and material as affecting this question. § 7. Skin friction--Its coefficient. § 8. Experimental proofs of its existence and importance 7 CHAPTER III. THE QUESTION OF BALANCE. § 1. automatic stability essential in a flying model. § 2. theoretical researches on this question. §§ 3-6. a brief summary of the chief conclusions arrived at--remarks on and deductions from the same--conditions for automatic stability. § 7. theory and practice--stringfellow--pénaud--tatin--the question of fins--clarke's models--some further considerations. § 8. longitudinal stability. § 9. transverse stability. § 10. the dihedral angle. § 11. different forms of the latter. § 12. the "upturned" tip. § 13. the most efficient section 13 CHAPTER IV. THE MOTIVE POWER. SECTION I.--RUBBER MOTORS. § 1. Some experiments with rubber cord. § 2. Its extension under various weights. § 3. The laws of elongation (stretching)--Permanent set. § 4. Effects of elongation on its volume. § 5. "Stretched-twisted" rubber cord--Torque experiments with rubber strands of varying length and number. § 6. Results plotted as graphs--Deductions--Various relations--How to obtain the most efficient results--Relations between the torque and the number of strands, and between the length of the strands and their number. § 7. Analogy between rubber and "spring" motors--Where it fails to hold. § 8. Some further practical deductions. § 9. The number of revolutions that can be given to rubber motors. § 10. The maximum number of turns. § 11. "Lubricants" for rubber. § 12. Action of copper upon rubber. § 12A. Action of water, etc. § 12B. How to preserve rubber. § 13. To test rubber. § 14. The shape of the section. § 15. Size of section. § 16. Geared rubber motors. § 17. The only system worth consideration--Its practical difficulties. § 18. Its advantages 24 SECTION II.--OTHER FORMS OF MOTORS. § 18A. _Spring motors_; their inferiority to rubber. § 18B. The most efficient form of spring motor. § 18C. _Compressed air motors_--A fascinating form of motor, "on paper." § 18D. The pneumatic drill--Application to a model aeroplane--Length of possible flight. § 18E. The pressure in motor-car tyres. § 19. Hargraves' compressed air models--The best results compared with rubber motors. § 20. The effect of heating the air in its passage from the reservoir to the motor--The great gain in efficiency thereby attained--Liquid air--Practical drawbacks to the compressed-air motor. § 21. Reducing valves--Lowest working pressure. § 22. The inferiority of this motor compared with the steam engine. § 22A. Tatin's air-compressed motor. § 23. _Steam engine_--Steam engine model--Professor Langley's models--His experiment with various forms of motive power--Conclusions arrived at. § 24. His steam engine models--Difficulties and failures--and final success--The "boiler" the great difficulty--His model described. § 25. The use of spirit or some very volatile hydrocarbon in the place of water. § 26. Steam turbines. § 27. Relation between "difficulty in construction" and the "size of the model." § 28. Experiments in France. § 29. _Petrol motors._--But few successful models. § 30. Limit to size. § 31. Stanger's successful model described and illustrated. § 32. One-cylinder petrol motors. § 33. _Electric motors_ 39 CHAPTER V. PROPELLERS OR SCREWS. § 1. The position of the propeller. § 2. The number of blades. § 3. Fan _versus_ propeller. § 4. The function of a propeller. § 5. The pitch. § 6. Slip. § 7. Thrust. § 8. Pitch coefficient (or ratio). § 9. Diameter. § 10. Theoretical pitch. § 11. Uniform pitch. § 12. How to ascertain the pitch of a propeller. § 13. Hollow-faced blades. § 14. Blade area. § 15. Rate of rotation. § 16. Shrouding. § 17. General design. § 18. The shape of the blades. § 19. Their general contour--Propeller design--How to design a propeller. § 20. Experiments with propellers--Havilland's design for experiments--The author experiments on dynamic thrust and model propellers generally. § 21. Fabric-covered screws. § 22. Experiments with twin propellers. § 23. The Fleming Williams propeller. § 24. Built-up _v._ twisted wooden propellers 52 CHAPTER VI. THE QUESTION OF SUSTENTATION. THE CENTRE OF PRESSURE. § 1. The centre of pressure--Automatic stability. § 2. Oscillations. § 3. Arched surfaces and movements of the centre of pressure--Reversal. § 4. The centre of gravity and the centre of pressure. § 5. Camber. § 6. Dipping front edge--Camber--The angle of incidence and camber--Attitude of the Wright machine. § 7. The most efficient form of camber. § 8. The instability of a deeply cambered surface. § 9. Aspect ratio. § 10. Constant or varying camber. § 11. Centre of pressure on arched surfaces 78 CHAPTER VII. MATERIALS FOR AEROPLANE CONSTRUCTION. § 1. The choice strictly limited. § 2. Bamboo. § 3. Ash--spruce-- whitewood--poplar. § 4. Steel. § 5. Umbrella section steel. § 6. Steel wire. § 7. Silk. § 8. Aluminium and magnalium. § 9. Alloys. § 10. Sheet ebonite--Vulcanized fibre--Sheet celluloid--Mica 86 CHAPTER VIII. HINTS ON THE BUILDING OF MODEL AEROPLANES. § 1. The chief difficulty to overcome. § 2. General design--The principle of continuity. § 3. Simple monoplane. § 4. Importance of soldering. § 5. Things to avoid. § 6. Aerofoil of metal--wood--or fabric. § 7. Shape of aerofoil. § 8. How to camber an aerocurve without ribs. § 9. Flexible joints. § 10. Single surfaces. § 11. The rod or tube carrying the rubber motor. § 12. Position of the rubber. § 13. The position of the centre of pressure. § 14. Elevators and tails. § 15. Skids _versus_ wheels--Materials for skids. § 16. Shock absorbers, how to attach--Relation between the "gap" and the "chord" 93 CHAPTER IX. THE STEERING OF THE MODEL. § 1. A problem of great difficulty--Effects of propeller torque. § 2. How obviated. § 3. The two-propeller solution--The reason why it is only a partial success. § 4. The _speed_ solution. § 5. Vertical fins. § 6. Balancing tips or ailerons. § 7. Weighting. § 8. By means of transversely canting the elevator. § 9. The necessity for some form of "keel" 105 CHAPTER X. THE LAUNCHING OF THE MODEL. § 1. The direction in which to launch them. § 2. The velocity--wooden aerofoils and fabric-covered aerofoils--Poynter's launching apparatus. § 3. The launching of very light models. § 4. Large size and power-driven models. § 5. Models designed to rise from the ground--Paulhan's prize model. § 6. The setting of the elevator. § 7. The most suitable propeller for this form of model. § 8. Professor Kress' method of launching. § 9. How to launch a twin screw model. § 10. A prior revolution of the propellers. § 11. The best angle at which to launch a model 109 CHAPTER XI. HELICOPTER MODELS. § 1. Models quite easy to make. § 2. Sir George Cayley's helicopter model. § 3. Phillips' successful power-driven model. § 4. Toy helicopters. § 5. Incorrect and correct way of arranging the propellers. § 6. Fabric covered screws. § 7. A design to obviate weight. § 8. The question of a fin or keel. 113 CHAPTER XII. EXPERIMENTAL RECORDS 116 CHAPTER XIII. MODEL FLYING COMPETITIONS. § 1. A few general details concerning such. § 2. Aero Models Association's classification, etc. § 3. Various points to be kept in mind when competing 119 CHAPTER XIV. USEFUL NOTES, TABLES, FORMULÆ, ETC. § 1. Comparative velocities. § 2. Conversions. § 3. Areas of various shaped surfaces. § 4. French and English measures. § 5. Useful data. § 6. Table of equivalent inclinations. § 7. Table of skin friction. § 8. Table I. (metals). § 9. Table II. (wind pressures). § 10. Wind pressure on various shaped bodies. § 11. Table III. (lift and drift) on a cambered surface. § 12. Table IV. (lift and drift)--On a plane aerofoil--Deductions. § 13. Table V. (timber). § 14. Formula connecting weight lifted and velocity. § 15. Formula connecting models of similar design but different weights. § 16. Formula connecting power and speed. § 17. Propeller thrust. § 18. To determine experimentally the static thrust of a propeller. § 19. Horse-power and the number of revolutions. § 20. To compare one model with another. § 21. Work done by a clockwork spring motor. § 22. To ascertain the horse-power of a rubber motor. § 23. Foot-pounds of energy in a given weight of rubber--Experimental determination of. § 24. Theoretical length of flight. § 25. To test different motors. § 26. Efficiency of a model. § 27. Efficiency of design. § 28. Naphtha engines. § 29. Horse-power and weight of model petrol motors. § 30. Formula for rating the same. § 30A. Relation between static thrust of propeller and total weight of model. § 31. How to find the height of an inaccessible object (kite, balloon, etc.). § 32. Formula for I.H.P. of model steam engines 125 APPENDIX A. Some models which have won medals at open competitions 143 GLOSSARY OF TERMS USED IN MODEL AEROPLANING. _Aeroplane._ A motor-driven flying machine which relies upon surfaces for its support in the air. _Monoplane_ (single). An aeroplane with one pair of outstretched wings. _Aerofoil._ These outstretched wings are often called aerofoil surfaces. One pair of wings forming one aerofoil surface. _Monoplane_ (double). An aeroplane with two aerofoils, one behind the other or two main planes, tandem-wise. _Biplane._ An aeroplane with two aerofoils, one below the other, or having two main planes superposed. _Triplane._ An aeroplane having three such aerofoils or three such main planes. _Multiplane._ Any such machine having more than three of the above. _Glider._ A motorless aeroplane. _Helicopter._ A flying machine in which propellers are employed to raise the machine in the air by their own unaided efforts. _Dihedral Angle._ A dihedral angle is an angle made by two surfaces that do not lie in the same plane, i.e. when the aerofoils are arranged V-shaped. It is better, however, to somewhat extend this definition, and not to consider it as necessary that the two surfaces _do_ actually meet, but would do so if produced thus in figure. BA and CD are still dihedrals, sometimes termed "upturned tips." [Illustration: Dihedrals.] _Span_ is the distance from tip to tip of the main supporting surface measured transversely (across) the line of flight. _Camber_ (a slight arching or convexity upwards). This term denotes that the aerofoil has such a curved transverse section. _Chord_ is the distance between the entering (or leading) edge of the main supporting surface (aerofoil) and the trailing edge of the same; also defined as the fore and aft dimension of the main planes measured in a straight line between the leading and trailing edges. span _Aspect Ratio_ is ----- chord _Gap_ is the vertical distance between one aerofoil and the one which is immediately above it. (The gap is usually made equal to the chord). _Angle of Incidence._ The angle of incidence is the angle made by the chord with the line of flight. [Illustration: AB = chord. AB = cambered surface. SP = line of flight. ASP = {alpha} = L of incidence.] _Width._ The width of an aerofoil is the distance from the front to the rear edge, allowing for camber. _Length._ This term is usually applied to the machine as a whole, from the front leading edge of elevator (or supports) to tip of tail. _Arched._ This term is usually applied to aerofoil surfaces which dip downwards like the wings of a bird. The curve in this case being at right angles to "camber." A surface can, of course, be both cambered and arched. _Propeller._ A device for propelling or pushing an aeroplane forward or for raising it vertically (lifting screw). _Tractor Screw._ A device for pulling the machine (used when the propeller is placed in the front of the machine). _Keel._ A vertical plane or planes (usually termed "fins") arranged longitudinally for the purposes of stability and steering. _Tail._ The plane, or group of planes, at the rear end of an aeroplane for the purpose chiefly of giving longitudinal stability. In such cases the tail is normally (approx.) horizontal, but not unfrequently vertical tail-pieces are fitted as well for steering (transversely) to the right or left, or the entire tail may be twisted for the purpose of transverse stability (vide _Elevator_). Such appendages are being used less and less with the idea of giving actual support. _Rudder_ is the term used for the vertical plane, or planes, which are used to steer the aeroplane sideways. _Warping._ The flexing or bending of an aerofoil out of its normal shape. The rear edges near the tips of the aerofoil being dipped or tilted respectively, in order to create a temporary difference in their inclinations to the line of flight. Performed in conjunction with rudder movements, to counteract the excessive action of the latter. _Ailerons_ (also called "righting-tips," "balancing-planes," etc.). Small aeroplanes in the vicinity of the tips of the main aerofoil for the purpose of assisting in the maintenance of equilibrium or for steering purposes either with or without the assistance of the rudder. _Elevator._ The plane, or planes, in front of the main aerofoil used for the purpose of keeping the aeroplane on an even keel, or which cause (by being tilted or dipped) the aeroplane to rise or fall (vide _Tail_). MODEL AEROPLANING INTRODUCTION. § 1. Model Aeroplanes are primarily divided into two classes: first, models intended before all else to be ones that shall _fly_; secondly, _models_, using the word in its proper sense of full-sized machines. Herein model aeroplanes differ from model yachts and model locomotives. An extremely small model locomotive _built to scale_ will still _work_, just as a very small yacht built to scale will _sail_; but when you try to build a scale model of an "Antoinette" monoplane, _including engine_, it cannot be made to fly unless the scale be a very large one. If, for instance, you endeavoured to make a 1/10 scale model, your model petrol motor would be compelled to have eight cylinders, each 0·52 bore, and your magneto of such size as easily to pass through a ring half an inch in diameter. Such a model could not possibly work.[1] _Note._--Readers will find in the "Model Engineer" of June 16, 1910, some really very fine working drawings of a prize-winning Antoinette monoplane model. § 2. Again, although the motor constitutes the _chief_, it is by no means the sole difficulty in _scale_ model aeroplane building. To reproduce to scale at _scale weight_, or indeed anything approaching it, _all_ the _necessary_--in the case of a full-sized machine--framework is not possible in a less than 1/5 scale. § 3. Special difficulties occur in the case of any prototype taken. For instance, in the case of model Blériots it is extremely difficult to get the centre of gravity sufficiently forward. § 4. Scale models of actual flying machines _that will fly_ mean models _at least_ 10 or 12 feet across, and every other dimension in like proportion; and it must always be carefully borne in mind that the smaller the scale the greater the difficulties, but not in the same proportion--it would not be _twice_ as difficult to build a ¼-in. scale model as a ½-in., but _four_, _five_ or _six_ times as difficult. § 5. Now, the _first_ requirement of a model aeroplane, or flying machine, is that it shall FLY. As will be seen later on--unless the machine be of large size, 10 feet and more spread--the only motor at our disposal is the motor of twisted rubber strands, and this to be efficient requires to be long, and is of practically uniform weight throughout; this alone alters the entire _distribution of weight_ on the machine and makes: § 6. "=Model Aeroplaning an Art in itself=," and as such we propose to consider it in the following pages. We have said that the first requisite of a model aeroplane is that it shall fly, but there is no necessity, nor is it indeed always to be desired, that this should be its only one, unless it be built with the express purpose of obtaining a record length of flight. For ordinary flights and scientific study what is required is a machine in which minute detail is of secondary importance, but which does along its main lines "_approximate_ to the real thing." § 7. Simplicity should be the first thing aimed at--simplicity means efficiency, it means it in full-sized machines, still more does it mean it in models--and this very question of simplicity brings us to that most important question of all, namely, the question of _weight_. FOOTNOTE: [1] The smallest working steam engine that the writer has ever heard of has a net weight of 4 grains. One hundred such engines would be required to weigh one ounce. The bore being 0·03 in., and stroke 1/32 of an inch, r.p.m. 6000 per min., h.p. developed 1/489000 ("Model Engineer," July 7, 1910). When working it hums like a bee. CHAPTER I. THE QUESTION OF WEIGHT. § 1. The following is an extract from a letter that appeared in the correspondence columns of "The Aero."[2] "To give you some idea how slight a thing will make a model behave badly, I fitted a skid to protect the propeller underneath the aeroplane, and the result in retarding flight could be seen very quickly, although the weight of the skid was almost nil.[3] To all model makers who wish to make a success I would say, strip all that useless and heavy chassis off, cut down the 'good, honest stick' that you have for a backbone to half its thickness, stay it with wire if it bends under the strain of the rubber, put light silk on the planes, and use an aluminium[4] propeller. The result will surpass all expectations." § 2. The above refers, of course, to a rubber-motor driven model. Let us turn to a steam-driven prototype. I take the best known example of all, Professor Langley's famous model. Here is what the professor has to say on the question[5]:-- "Every bit of the machinery had to be constructed with scientific accuracy. It had to be tested again and again. The difficulty of getting the machine light enough was such that every part of it had to be remade several times. It would be in full working order when something would give way, and this part would have to be strengthened. This caused additional weight, and necessitated cutting off so much weight from some other part of the machinery. At times the difficulty seemed almost heartbreaking; but I went on, piece by piece and atom by atom, until I at last succeeded in getting all the parts of the right strength and proportion." How to obtain the maximum strength with the minimum of weight is one of the, if not the most, difficult problems which the student has to solve. § 3. The theoretical reason why _weight_ is such an all-important item in model aeroplaning, much more so than in the case of full-size machines, is that, generally speaking, such models do not fly fast enough to possess a high weight carrying capacity. If you increase the area of the supporting surface you increase also the resistance, and thereby diminish the speed, and are no better off than before. The only way to increase the weight carrying capacity of a model is to increase its speed. This point will be recurred to later on. One of Mr. T.W.K. Clarke's well-known models, surface area 1¼ sq. ft., weight 1¼ lb., is stated to have made a flight of 300 yards carrying 6 oz. of lead. This works out approximately at 21 oz. per sq. ft. The velocity (speed) is not stated, but some earlier models by the same designer, weight 1½ lb., supporting area 1½ sq. ft., i.e., at rate of 16 oz. per sq. ft., travelled at a rate of 37 ft. per second, or 25 miles an hour. The velocity of the former, therefore, would certainly not be less than 30 miles an hour. § 4. Generally speaking, however, models do not travel at anything like this velocity, or carry anything like this weight per sq. ft. An average assumption of 13 to 15 miles an hour does nor err on the minimum side. Some very light fabric covered models have a speed of less than even 10 miles an hour. Such, of course, cannot be termed efficient models, and carry only about 3 oz. per sq. ft. Between these two types--these two extremes--somewhere lies the "Ideal Model." The maximum of strength with the minimum of weight can be obtained only:-- 1. By a knowledge of materials. 2. Of how to combine those materials in a most efficient and skilful manner. 3. By a constant use of the balance or a pair of scales, and noting (in writing) the weight and result of every trial and every experiment in the alteration and change of material used. WEIGH EVERYTHING. § 5. The reader must not be misled by what has been said, and think that a model must not weigh anything if it is to fly well. A heavy model will fly much better against the wind than a light one, provided that the former _will_ fly. To do this it must fly _fast_. To do this again it must be well powered, and offer the minimum of resistance to the medium through which it moves. This means its aerofoil (supporting) surfaces must be of polished wood or metal. This point brings us to the question of Resistance, which we will now consider. FOOTNOTES: [2] "Aero," May 3, 1910. [3] Part of this retardation was, of course, "increased resistance." [4] Personally I do not recommend aluminium.--V.E.J. [5] "Aeronautical Journal," January 1897, p. 7. CHAPTER II. THE QUESTION OF RESISTANCE. § 1. It is, or should be, the function of an aeroplane--model or otherwise--to pass through the medium in which it travels in such a manner as to leave that medium in as motionless a state as possible, since all motion of the surrounding air represents so much power wasted. Every part of the machine should be so constructed as to move through the air with the minimum of disturbance and resistance. § 2. The resistance, considered as a percentage of the load itself, that has to be overcome in moving a load from one place to another, is, according to Mr. F.W. Lanchester, 12½ per cent. in the case of a flying machine, and 0·1 per cent. in the case of a cargo boat, and of a solid tyre motor car 3 per cent., a locomotive 1 per cent. Four times at least the resistance in the case of aerial locomotion has to be overcome to that obtained from ordinary locomotion on land. The above refer, of course, to full-sized machines; for a model the resistance is probably nearer 14 or 15 per cent. § 3. This resistance is made up of-- 1. Aerodynamic resistance. 2. Head resistance. 3. Skin-friction (surface resistance). The first results from the necessity of air supporting the model during flight. The second is the resistance offered by the framework, wires, edges of aerofoils, etc. The third, skin-friction or surface resistance, is very small at low velocities, but increases as the square of the velocity. To reduce the resistance which it sets up, all surfaces used should be as smooth as possible. To reduce the second, contours of ichthyoid, or fish-like, form should be used, so that the resultant stream-line flow of the medium shall keep in touch with the surface of the body. § 4. As long ago as 1894 a series of experiments were made by the writer[6] to solve the following problem: given a certain length and breadth, to find the shape which will offer the least resistance. The experiments were made with a whirling table 40 ft. in diameter, which could be rotated so that the extremity of the arm rotated up to a speed of 45 miles an hour. The method of experimenting was as follows: The bodies (diam. 4 in.) were balanced against one another at the extremity of the arm, being so balanced that their motions forward and backward were parallel. Provision was made for accurately balancing the parallel scales on which the bodies were suspended without altering the resistance offered by the apparatus to the air. Two experiments at least (to avoid error) were made in each case, the bodies being reversed in the second experiment, the top one being put at the bottom, and _vice versa_. The conclusions arrived at were:-- For minimum (head) resistance a body should have-- 1. Its greatest diameter two-fifths of its entire length from its head. 2. Its breadth and its depth in the proportion of four to three. 3. Its length at least from five to nine times its greatest breadth (nine being better than five). 4. A very tapering form of stern, the actual stern only being of just sufficient size to allow of the propeller shaft passing through. In the case of twin propellers some slight modification of the stern would be necessary. 5. Every portion of the body in contact with the fluid to be made as smooth as possible. 6. A body of such shape gives at most only _one-twentieth_ the resistance offered by a flat disk of similar maximum sectional area. _Results since fully confirmed._ [Illustration: FIG. 1.--SHAPE OF LEAST RESISTANCE.] The design in Fig. 2 is interesting, not only because of its probable origin, but because of the shape of the body and arrangement of the propellers; no rudder is shown, and the long steel vertical mast extending both upwards and downwards through the centre would render it suitable only for landing on water. § 5. In the case of a rubber-driven model, there is no containing body part, so to speak, a long thin stick, or tubular construction if preferred, being all that is necessary. The long skein of elastic, vibrating as well as untwisting as it travels with the machine through the air, offers some appreciable resistance, and several experimenters have _enclosed_ it in a light tube made of _very thin_ veneer wood rolled and glued, or paper even may be used; such tubes can be made very light, and possess considerable rigidity, especially longitudinally. If the model be a biplane, then all the upright struts between the two aerofoils should be given a shape, a vertical section of which is shown in Fig. 3. § 6. In considering this question of resistance, the substance of which the aerofoil surface is made plays a very important part, as well as whether that surface be plane or curved. For some reason not altogether easy to determine, fabric-covered planes offer _considerably_ more resistance than wooden or metal ones. That they should offer _more_ resistance is what common sense would lead one to expect, but hardly to the extent met with in actual practice. [Illustration: FIG. 2.--DESIGN FOR AN AEROPLANE MODEL (POWER DRIVEN). This design is attributed to Professor Langley.] _Built up fabric-covered aeroplanes[7] gain in lightness, but lose in resistance._ In the case of curved surfaces this difference is considerably more; one reason, undoubtedly, is that in a built up model surface there is nearly always a tendency to make this curvature excessive, and much more than it should be. Having called attention to this under the head of resistance, we will leave it now to recur to it later when considering the aerofoil proper. [Illustration: FIG. 3.--HORIZONTAL SECTION OF VERTICAL STRUT (ENLARGED.)] § 7. Allusion has been made in this chapter to skin friction, but no value given for its coefficient.[8] Lanchester's value for planes from ½ to 1½ sq. ft. in area, moving about 20 to 30 ft. per second, is 0·009 to 0·015. Professor Zahm (Washington) gives 0·0026 lb. per sq. ft. at 25 ft. per second, and at 37 ft. per second, 0·005, and the formula _f_ = 0·00000778_l_^{·93}_v_^{1·85} _f_ being the average friction in lb. per sq. in., _l_ the length in feet, and _v_ the velocity in ft. per second. He also experimented with various kinds of surfaces, some rough, some smooth, etc. His conclusion is:--"All even surfaces have approximately the same coefficient of skin friction. Uneven surfaces have a greater coefficient." All formulæ on skin friction must at present be accepted with reserve. § 8. The following three experiments, however, clearly prove its _existence_, and _that it has considerable effect_:-- 1. A light, hollow celluloid ball, supported on a stream of air projected upwards from a jet, rotates in one direction or the other as the jet is inclined to the left or to the right. (F.W. Lanchester.) 2. When a golf ball (which is rough) is hit so as to have considerable underspin, its range is increased from 135 to 180 yards, due entirely to the greater frictional resistance to the air on that side on which the whirl and the progressive motion combine. (Prof. Tait.) 3. By means of a (weak) bow a golf ball can be made to move point blank to a mark 30 yards off, provided the string be so adjusted as to give a good underspin; adjust the string to the centre of the ball, instead of catching it below, and the drop will be about 8 ft. (Prof. Tait.) FOOTNOTES: [6] _Vide_ "Invention," Feb. 15, 22, and 29, 1896. [7] Really aerofoils, since we are considering only the supporting surface. [8] I.e., to express it as a decimal fraction of the resistance, encountered by the same plane when moving "face" instead of "edge" on. CHAPTER III. THE QUESTION OF BALANCE. § 1. It is perfectly obvious for successful flight that any model flying machine (in the absence of a pilot) must possess a high degree of automatic stability. The model must be so constructed as to be naturally stable, _in the medium through which it is proposed to drive it_. The last remark is of the greatest importance, as we shall see. § 2. In connexion with this same question of automatic stability, the question must be considered from the theoretical as well as from the practical side, and the labours and researches of such men as Professors Brian and Chatley, F.W. Lanchester, Captain Ferber, Mouillard and others must receive due weight. Their work cannot yet be fully assessed, but already results have been arrived at far more important than are generally supposed. The following are a few of the results arrived at from theoretical considerations; they cannot be too widely known. (A) Surfaces concave on the under side are not stable unless some form of balancing device (such as a tail, etc.) is used. (B) If an aeroplane is in equilibrium and moving uniformly, it is necessary for stability that it shall tend towards a condition of equilibrium. (C) In the case of "oscillations" it is absolutely necessary for stability that these oscillations shall decrease in amplitude, in other words, be damped out. (D) In aeroplanes in which the dihedral angle is excessive or the centre of gravity very low down, a dangerous pitching motion is quite likely to be set up. [Analogy in shipbuilding--an increase in the metacentre height while increasing the stability in a statical sense causes the ship to do the same.] (E) The propeller shaft should pass through the centre of gravity of the machine. (F) The front planes should be at a greater angle of inclination than the rear ones. (G) The longitudinal stability of an aeroplane grows much less when the aeroplane commences to rise, a monoplane becoming unstable when the angle of ascent is greater than the inclination of the main aerofoil to the horizon. (H) Head resistance increases stability. (I) Three planes are more stable than two. [Elevator--main aerofoil--horizontal rudder behind.] (J) When an aeroplane is gliding (downwards) stability is greater than in horizontal flight. (K) A large moment of inertia is inimical (opposed) to stability. (M) Aeroplanes (naturally) stable up to a certain velocity (speed) may become unstable when moving beyond that speed. [Possible explanation. The motion of the air over the edges of the aerofoil becomes turbulent, and the form of the stream lines suddenly changes. Aeroplane also probably becomes deformed.] (N) In a balanced glider for stability a separate surface at a negative angle to the line of flight is essential. [Compare F.] (O) A keel surface should be situated well above and behind the centre of gravity. (P) An aeroplane is a conservative system, and stability is greatest when the kinetic energy is a maximum. [Illustration, the pendulum.] § 3. Referring to A. Models with a plane or flat surface are not unstable, and will fly well without a tail; such a machine is called a simple monoplane. [Illustration: FIG. 4.--ONE OF MR. BURGE WEBB'S SIMPLE MONOPLANES. Showing balance weight A (movable), and also his winding-up gear--a very handy device.] § 4. Referring to D. Many model builders make this mistake, i.e., the mistake of getting as low a centre of gravity as possible under the quite erroneous idea that they are thereby increasing the stability of the machine. Theoretically the _centre of gravity should be the centre of head resistance, as also the centre of pressure_. In practice some prefer to put the centre of gravity in models _slightly_ above the centre of head resistance, the reason being that, generally speaking, wind gusts have a "lifting" action on the machine. It must be carefully borne in mind, however, that if the centre of wind pressure on the aerofoil surface and the centre of gravity do not coincide, no matter at what point propulsive action be applied, it can be proved by quite elementary mechanics that such an arrangement, known as "acentric," produces a couple tending to upset the machine. This action is the probable cause of many failures. [Illustration: FIG. 5.--THE STRINGFELLOW MODEL MONOPLANE OF 1848.] § 5. Referring to E. If the propulsive action does not pass through the centre of gravity the system again becomes "acentric." Even supposing condition D fulfilled, and we arrive at the following most important result, viz., that for stability:-- THE CENTRES OF GRAVITY, OF PRESSURE, OF HEAD RESISTANCE, SHOULD BE COINCIDENT, AND THE PROPULSIVE ACTION OF THE PROPELLER PASS THROUGH THIS SAME POINT. [Illustration: FIG. 6.--THE STRINGFELLOW MODEL TRIPLANE OF 1868.] § 6. Referring to F and N--the problem of longitudinal stability. There is one absolutely essential feature not mentioned in F or N, and that is for automatic longitudinal stability _the two surfaces, the aerofoil proper and the balancer_ (elevator or tail, or both), _must be separated by some considerable distance, a distance not less than four times the width of the main aerofoil_.[9] More is better. [Illustration: FIG. 7. _PÉNAUD 1871_] § 7. With one exception (Pénaud) early experimenters with model aeroplanes had not grasped this all-important fact, and their models would not fly, only make a series of jumps, because they failed to balance longitudinally. In Stringfellow's and Tatin's models the main aerofoil and balancer (tail) are practically contiguous. Pénaud in his rubber-motored models appears to have fully realised this (_vide_ Fig. 7), and also the necessity for using long strands of rubber. Some of his models flew 150 ft., and showed considerable stability. [Illustration: FIG. 8.--TATIN'S AEROPLANE (1879). Surface 0·7 sq. metres, total weight 1·75 kilogrammes, velocity of sustentation 8 metres a second. Motor, compressed air (for description see § 23, ch. iv). Revolved round and round a track tethered to a post at the centre. In one of its jumps it cleared the head of a spectator.] With three surfaces one would set the elevator at a slight plus angle, main aerofoil horizontal (neither positive nor negative), and the tail at a corresponding negative angle to the positive one of the elevator. Referring to O.[10] One would naturally be inclined to put a keel surface--or, in other words, vertical fins--beneath the centre of gravity, but D shows us this may have the opposite effect to what we might expect. In full-sized machines, those in which the distance between the main aerofoil and balancers is considerable (like the Farman) show considerable automatic longitudinal stability, and those in which it is short (like the Wright) are purposely made so with the idea of doing away with it, and rendering the machine quicker and more sensitive to personal control. In the case of the Stringfellow and Tatin models we have the extreme case--practically the bird entirely volitional and personal--which is the opposite in every way to what we desire on a model under no personal or volitional control at all. [Illustration: FIG. 9.--CLARK'S MODEL FLYER. Main aerofoil set at a slight negative angle. Dihedral angles on both aerofoils.] The theoretical conditions stated in F and N are fully borne out in practice. And since a curved aerofoil even when set at a _slight_ negative angle has still considerable powers of sustentation, it is possible to give the main aerofoil a slight negative angle and the elevator a slight positive one. This fact is of the greatest importance, since it enables us to counteract the effect of the travel of the "centre of pressure."[11] [Illustration: FIG. 10.--LARGE MODEL MONOPLANE. Designed and constructed by the author, with vertical fin (no dihedral angle). With a larger and more efficient propeller than the one here shown some excellent flights were obtained. Constructed of bamboo and nainsook. Stayed with steel wire.] § 8. Referring to I. This, again, is of primary importance in longitudinal stability. The Farman machine has three such planes--elevator, main aerofoil, tail the Wright originally had _not_, but is now being fitted with a tail, and experiments on the Short-Wright biplane have quite proved its stabilising efficiency. The three plane (triple monoplane) in the case of models has been tried, but possesses no advantage so far over the double monoplane type. The writer has made many experiments with vertical fins, and has found the machine very stable, even when the fin or vertical keel is placed some distance above the centre of gravity. § 9. The question of transverse (side to side) stability at once brings us to the question of the dihedral angle, practically similar in its action to a flat plane with vertical fins. [Illustration: FIG. 11.--SIR GEORGE CAYLEY'S FLYING MACHINE. Eight feathers, two corks, a thin rod, a piece of whalebone, and a piece of thread.] § 10. The setting up of the front surface at an angle to the rear, or the setting of these at corresponding compensatory angles already dealt with, is nothing more nor less than the principle of the dihedral angle for longitudinal stability. [Illustration: FIG. 12.--VARIOUS FORMS OF DIHEDRALS.] As early as the commencement of last century Sir George Cayley (a man more than a hundred years ahead of his times) was the first to point out that two planes at a dihedral angle constitute a basis of stability. For, on the machine heeling over, the side which is required to rise gains resistance by its new position, and that which is required to sink loses it. § 11. The dihedral angle principle may take many forms. As in Fig. 12 _a_ is a monoplane, the rest biplanes. The angles and curves are somewhat exaggerated. It is quite a mistake to make the angle excessive, the "lift" being thereby diminished. A few degrees should suffice. Whilst it is evident enough that transverse stability is promoted by making the sustaining surface trough-shaped, it is not so evident what form of cross section is the most efficient for sustentation and equilibrium combined. [Illustration: FIG. 13.] It is evident that the righting moment of a unit of surface of an aeroplane is greater at the outer edge than elsewhere, owing to the greater lever arm. § 12. The "upturned tip" dihedral certainly appears to have the advantage. _The outer edges of the aerofoil then should be turned upward for the purpose of transverse stability, while the inner surface should remain flat or concave for greater support._ § 13. The exact most favourable outline of transverse section for stability, steadiness and buoyancy has not yet been found; but the writer has found the section given in Fig. 13, a very efficient one. FOOTNOTES: [9] If the width be not uniform the mean width should be taken. [10] This refers, of course, to transverse stability. [11] See ch. vi. CHAPTER IV. THE MOTIVE POWER. SECTION I.--RUBBER MOTORS. § 1. Some forty years have elapsed since Pénaud first used elastic (rubber) for model aeroplanes, and during that time no better substitute (in spite of innumerable experiments) has been found. Nor for the smaller and lighter class of models is there any likelihood of rubber being displaced. Such being the case, a brief account of some experiments on this substance as a motive power for the same may not be without interest. The word _elastic_ (in science) denotes: _the tendency which a body has when distorted to return to its original shape_. Glass and ivory (within certain limits) are two of the most elastic bodies known. But the limits within which most bodies can be distorted (twisted or stretched, or both) without either fracture or a LARGE _permanent_ alteration of shape is very small. Not so rubber--it far surpasses in this respect even steel springs. § 2. Let us take a piece of elastic (rubber) cord, and stretch it with known weights and observe carefully what happens. We shall find that, first of all: _the extension is proportional to the weight suspended_--but soon we have an _increasing_ increase of extension. In one experiment made by the writer, when the weights were removed the rubber cord remained 1/8 of an inch longer, and at the end of an hour recovered itself to the extent of 1/16, remaining finally permanently 1/16 of an inch longer. Length of elastic cord used in this experiment 8-1/8 inches, 3/16 of an inch thick. Suspended weights, 1 oz. up to 64 oz. Extension from ¼ inch up to 24-5/8 inches. Graph drawn in Fig. 14, No. B abscissæ extension in eighths of an inch, ordinates weights in ounces. So long as the graph is a straight line it shows the extension is proportional to the suspended weight; afterwards in excess. [Illustration: FIG. 14.--WEIGHT AND EXTENSION. B, rubber 3/16 in. thick; C, 2/16 in. thick; D, 1/16 in. thick. A, theoretical line if extension were proportional to weight.] In this experiment we have been able to stretch (distort) a piece of rubber to more than three times its original length, and afterwards it finally returns to almost its original length: not only so, a piece of rubber cord can be stretched to eight or nine times its original length without fracture. Herein lies its supreme advantage over steel or other springs. Weight for weight more energy can be got or more work be done by stretched (or twisted, or, to speak more correctly, by stretched-twisted) rubber cord than from any form of steel spring.[12] It is true it is stretched--twisted--far beyond what is called the "elastic limit," and its efficiency falls off, but with care not nearly so quickly as is commonly supposed, but in spite of this and other drawbacks its advantages far more than counterbalance these. § 3. Experimenting with cords of varying thickness we find that: _the extension is inversely proportional to the thickness_. If we leave a weight hanging on a piece of rubber cord (stretched, of course, beyond its "elastic limit") we find that: _the cord continues to elongate as long as the weight is left on_. For example: a 1 lb. weight hung on a piece of rubber cord, 8-1/8 inches long and 1/8 of an inch thick, stretched it--at first--6¼ inches; after two minutes this had increased to 6-5/8 (3/8 of an inch more). One hour later 1/8 of an inch more, and sixteen hours later 1/8 of an inch more, i.e. a sixteen hours' hang produced an additional extension of ¾ of an inch. On a thinner cord (half the thickness) same weight produced _an additional extension_ (_after_ 14 _hours_) _of _10-3/8 _in_. N.B.--An elastic cord or spring balance should never have a weight left permanently on it--or be subjected to a distorting force for a longer time than necessary, or it will take a "permanent set," and not return to even approximately its original length or form. In a rubber cord the extension is _directly proportional to the length_ as well as _inversely proportional to the thickness and to the weight suspended_--true only within the limits of elasticity. [Illustration: FIG. 15.--EXTENSION AND INCREASE IN VOLUME.] § 4. =When a Rubber Cord is stretched there is an Increase of Volume.=--On stretching a piece of rubber cord to _twice_ its original (natural) length, we should perhaps expect to find that the string would only be _half_ as thick, as would be the case if the volume remained the same. Performing the experiment, and measuring the cord as accurately as possible with a micrometer, measuring to the one-thousandth of an inch, we at once perceive that this is not the case, being about _two-thirds_ of its former volume. § 5. In the case of rubber cord used for a motive power on model aeroplanes, the rubber is _both_ twisted and stretched, but chiefly the latter. Thirty-six strands of rubber, weight about 56 grammes, at 150 turns give a torque of 4 oz. on a 5-in. arm, but an end thrust, or end pull, of about 3½ lb. (Ball bearings, or some such device, can be used to obviate this end thrust when desirable.) A series of experiments undertaken by the writer on the torque produced by twisted rubber strands, varying in number, length, etc., and afterwards carefully plotted out in graph form, have led to some very interesting and instructive results. Ball bearings were used, and the torque, measured in eighths of an ounce, was taken (in each case) from an arm 5 in. in length. The following are the principal results arrived at. For graphs, see Fig. 16. § 6. A. Increasing the number of (rubber) strands by _one-half_ (length and thickness of rubber remaining constant) increases the torque (unwinding tendency) _twofold_, i.e., doubles the motive power. B. _Doubling_ the number of strands increases the torque _more than three times_--about 3-1/3 times, 3 times up to 100 turns, 3½ times from 100 to 250 turns. C. _Trebling_ the number of strands increases the torque at least _seven times_. The increased _size_ of the coils, and thereby _increased_ extension, explains this result. As we increase the number of strands, the _number_ of twists or turns that can be given it becomes less. D. _Doubling_ the number of strands (length, etc., remaining constant) _diminishes_ the number of turns by _one-third to one-half_. (In few strands one-third, in 30 and over one-half.) [Illustration: FIG. 16.--TORQUE GRAPHS OF RUBBER MOTORS. Abscissæ = Turns. Ordinates = Torque measured in 1/16 of an oz. Length of arm, 5 in. A. 38 strands of new rubber, 2 ft. 6 in. long; 58 grammes weight. B. 36 strands, 2 ft. 6 in. long; end thrust at 150 turns, 3½ lb. C. 32 strands, 2 ft. 6 in. long. D. 24 " " " E. 18 " " " weight 28 grammes. F. 12 " 1 ft. 3 in. long G. 12 " 2 ft. 6 in. long.] E. If we halve the length of the rubber strands, keeping the _number_ of strands the same, the torque is but slightly increased for the first 100 turns; at 240 turns it is double. But the greater number of turns--in ratio of about 2:1--that can be given the longer strand much more than compensates for this. F. No arrangement of the strands, _per se_, gets more energy (more motive power) out of them than any other, but there are special reasons for making the strands-- G. As long and as few in number as possible. 1. More turns can be given it. 2. It gives a far more even torque. Twelve strands 2 ft. 6 in. long give practically a line of small constant angle. Thirty-six strands same length a much steeper angle, with considerable variations. A very good result, which the writer has verified in practice, paying due regard to _both_ propeller and motor, is to make-- H. _The length of the rubber strands twice[13] in feet the number of the strands in inches_,[14] e.g., if the number of strands is 12 their length should be 2 ft., if 18, 3 ft., and so on. § 7. Experiments with 32 to 38 strands 2 ft. 6 in. long give a torque curve almost precisely similar to that obtained from experiments made with flat spiral steel springs, similar to those used in watches and clocks; and, as we know, the torque given by such springs is very uneven, and has to be equalised by use of a fusee, or some such device. In the case of such springs it must not be forgotten that the turning moment (unwinding tendency) is NOT proportional to the amount of winding up, this being true only in the "balance" springs of watches, etc., where _both_ ends of the spring are rigidly fastened. In the case of SPRING MOTORS.[15] I. The turning moment (unwinding tendency) is proportional to the difference between the angle of winding and yielding, proportional to the moment of inertia of its section, i.e., to the breadth and the cube of its thickness, also proportional to the modulus of elasticity of the substance used, and inversely proportional to the length of the strip. § 8. Referring back to A, B, C, there are one or two practical deductions which should be carefully noted. Supposing we have a model with one propeller and 36 strands of elastic. If we decide to fit it with twin screws, then, other reasons apart, we shall require two sets of strands of more than 18 in number each to have the same motive power (27 if the same torque be required).[16] This is an important point, and one not to be lost sight of when thinking of using two propellers. Experiments on-- §9. =The Number of Revolutions= (turns) =that can be given to Rubber Motors= led to interesting results, e.g., the number of turns to produce a double knot in the cord from end to end were, in the case of rubber, one yard long:-- No. of Strands. No. of Turns. No. of Strands. No. of Turns. 4 440 16 200 8 310 28 170 12 250 It will be at once noticed that the greater the number of rubber strands used in a given length, the fewer turns will it stand in proportion. For instance, 8 strands double knot at 310, and 4 at 440 (and not at 620), 16 at 200, and 8 at 310 (and not 400), and so on. The reason, of course, is the more the strands the greater the distance they have to travel round themselves. § 10. =The Maximum Number of Turns.=--As to the maximum number of permissible turns, rubber has rupture stress of 330 lb. per sq. in., _but a very high permissible stress_, as much as 80 per cent. The resilience (power of recovery after distortion) in tension of rubber is in considerable excess of any other substance, silk being the only other substance which at all approaches it in this respect, the ratio being about 11 : 9. The resilience of steel spiral spring is very slight in comparison. A rubber motor in which the double knot is not exceeded by more than 100 turns (rubber one yard in length) should last a good time. When trying for a record flight, using new elastic, as many as even 500 or 600 or even more turns have been given in the case of 32-36 strands a yard in length; but such a severe strain soon spoils the rubber. § 11. =On the Use of "Lubricants."=--One of the drawbacks to rubber is that if it be excessively strained it soon begins to break up. One of the chief causes of this is that the strands stick together--they should always be carefully separated, if necessary, after a flight--and an undue strain is thereby cast on certain parts. Apart also from this the various strands are not subject to the same tension. It has been suggested that if some means could be devised to prevent this, and allow the strands to slip over one another, a considerable increase of power might result. It must, however, be carefully borne in mind that anything of an oily or greasy nature has an injurious effect on the rubber, and must be avoided at all costs. Benzol, petroleum, ether, volatile oils, turpentine, chloroform, naphtha, vaseline, soap, and all kinds of oil must be carefully avoided, as they soften the rubber, and reduce it more or less to the consistence of a sticky mass. The only oil which is said to have no action on rubber, or practically none, is castor oil; all the same, I do not advise its use as a lubricant. There are three only which we need consider:-- 1. Soda and water. 2. French chalk. 3. Pure redistilled glycerine. The first is perfectly satisfactory when freshly applied, but soon dries up and evaporates. The second falls off; and unless the chalk be of the softest kind, free from all grit and hard particles, it will soon do more harm than good. The third, glycerine, is for ordinary purposes by far the best, and has a beneficial rather than a deleterious effect on the rubber; but it must be _pure_. The redistilled kind, free from all traces of arsenic, grease, etc., is the only kind permissible. It does not evaporate, and a few drops, comparatively speaking, will lubricate fifty or sixty yards of rubber. Being of a sticky or tacky nature it naturally gathers up dust and particles of dirt in course of time. To prevent these grinding into the rubber, wash it from time to time in warm soda, and warm and apply fresh glycerine when required. Glycerine, unlike vaseline (a product of petroleum), is not a grease; it is formed from fats by a process known as _saponification_, or treatment of the oil with caustic alkali, which decomposes the compound, forming an alkaline stearate (soap), and liberating the glycerine which remains in solution when the soap is separated by throwing in common salt. In order to obtain pure glycerine, the fat can be decomposed by lead oxide, the glycerine remaining in solution, and the lead soap or plaster being precipitated. By using glycerine as a lubricant the number of turns that can be given a rubber motor is greatly increased, and the coils slip over one another freely and easily, and prevent the throwing of undue strain on some particular portion, and absolutely prevent the strands from sticking together. § 12. =The Action of Copper upon Rubber.=--Copper, whether in the form of the metal, the oxides, or the soluble salts, has a marked injurious action upon rubber. In the case of metallic copper this action has been attributed to oxidation induced by the dissolved oxygen in the copper. In working drawings for model aeroplanes I have noticed designs in which the hooks on which the rubber strands were to be stretched were made of _copper_. In no case should the strands be placed upon bare metal. I always cover mine with a piece of valve tubing, which can easily be renewed from time to time. § 12A. =The Action of Water, etc., on Rubber.=--Rubber is quite insoluble in water; but it must not be forgotten that it will absorb about 25 per cent. into its pores after soaking for some time. Ether, chloroform, carbon-tetrachloride, turpentine, carbon bi-sulphide, petroleum spirit, benzene and its homologues found in coal-tar naphtha, dissolve rubber readily. Alcohol is absorbed by rubber, but is not a solvent of it. § 12B. =How to Preserve Rubber.=--In the first place, in order that it shall be _possible_ to preserve and keep rubber in the best condition of efficiency, it is absolutely essential that the rubber shall be, when obtained, fresh and of the best kind. Only the best Para rubber should be bought; to obtain it fresh it should be got in as large quantities as possible direct from a manufacturer or reliable rubber shop. The composition of the best Para rubber is as follows:--Carbon, 87·46 per cent.; hydrogen, 12·00 per cent.; oxygen and ash, 0·54 per cent. In order to increase its elasticity the pure rubber has to be vulcanised before being made into the sheet some sixty or eighty yards in length, from which the rubber threads are cut; after vulcanization the substance consists of rubber plus about 3 per cent. of sulphur. Now, unfortunately, the presence of the sulphur makes the rubber more prone to atmospheric oxidation. Vulcanized rubber, compared to pure rubber, has then but a limited life. It is to this process of oxidation that the more or less rapid deterioration of rubber is due. To preserve rubber it should be kept from the sun's rays, or, indeed, any actinic rays, in a cool, airy place, and subjected to as even a temperature as possible. Great extremes of temperature have a very injurious effect on rubber, and it should be washed from time to time in warm soda water. It should be subjected to no tension or compression. Deteriorated rubber is absolutely useless for model aeroplanes. § 13. =To Test Rubber.=--Good elastic thread composed of pure Para rubber and sulphur should, if properly made, stretch to seven times its length, and then return to its original length. It should also possess a stretching limit at least ten times its original length. As already stated, the threads or strands are cut from sheets; these threads can now be cut fifty to the inch. For rubber motors a very great deal so far as length of life depends on the accuracy and skill with which the strands are cut. When examined under a microscope (not too powerful) the strands having the least ragged edge, i.e., the best cut, are to be preferred. § 14. =The Section--Strip or Ribbon versus Square.=--In section the square and not the ribbon or strip should be used. The edge of the strip I have always found more ragged under the microscope than the square. I have also found it less efficient. Theoretically no doubt a round section would be best, but none such (in small sizes) is on the market. Models have been fitted with a tubular section, but such should on no account be used. § 15. =Size of the Section.=--One-sixteenth or one-twelfth is the best size for ordinary models; personally, I prefer the thinner. If more than a certain number of strands are required to provide the necessary power, a larger size should be used. It is not easy to say _what_ this number is, but fifty may probably be taken as an outside limit. Remember the size increases by area section; twice the _sectional_ height and breadth means four times the rubber. § 16. =Geared Rubber Motors.=--It is quite a mistake to suppose that any advantage can be obtained by using a four to one gearing, say; all that you do obtain is one-fourth of the power minus the increased friction, minus the added weight. This presumes, of course, you make no alteration in your rubber strands. Gearing such as this means _short_ rubber strands, and such are not to be desired; in any case, there is the difficulty of increased friction and added weight to overcome. It is true by splitting up your rubber motor into two sets of strands instead of one you can obtain more turns, but, as we have seen, you must increase the number of strands to get the same thrust, and you have this to counteract any advantage you gain as well as added weight and friction. § 17. The writer has tried endless experiments with all kinds of geared rubber motors, and the only one worth a moment's consideration is the following, viz., one in which two gear wheels--same size, weight, and number of teeth--are made use of, the propeller being attached to the axle of one of them, and the same number of strands are used on each axle. The success or non-success of this motor depends entirely on the method used in its construction. At first sight it may appear that no great skill is required in the construction of such a simple piece of apparatus. No greater mistake could be made. It is absolutely necessary that _the friction and weight be reduced to a minimum_, and the strength be a maximum. The torque of the rubber strands on so short an arm is very great. Ordinary light brass cogwheels will not stand the strain. A. The cogwheels should be of steel[17] and accurately cut of diameter sufficient to separate the two strands the requisite distance, _but no more_. B. The weight must be a minimum. This is best attained by using solid wheels, and lightening by drilling and turning. C. The friction must be a minimum. Use the lightest ball bearings obtainable (these weigh only 0·3 gramme), adjust the wheels so that they run with the greatest freedom, but see that the teeth overlap sufficiently to stand the strain and slight variations in direction without fear of slipping. Shallow teeth are useless. D. Use vaseline on the cogs to make them run as easily as possible. [Illustration: FIG. 17.--GEARED RUBBER MOTOR. Designed and constructed by the writer. For description of the model, etc., see Appendix.] E. The material of the containing framework must be of maximum strength and minimum lightness. Construct it of minimum size, box shaped, use the thinnest tin (really tinned sheet-iron) procurable, and lighten by drilling holes, not too large, all over it. Do not use aluminium or magnalium. Steel, could it be procured thin enough, would be better still. F. Use steel pianoforte wire for the spindles, and hooks for the rubber strands, using as thin wire as will stand the strain. Unless these directions are carefully carried out no advantage will be gained--the writer speaks from experience. The requisite number of rubber strands to give the best result must be determined by experiment. § 18. One advantage in using such a motor as this is that the two equal strands untwisting in opposite directions have a decided steadying effect on the model, similar almost to the case in which two propellers are used. The "best" model flights that the writer has achieved have been obtained with a motor of this description.[18] In the case of twin screws two such gearings can be used, and the rubber split up into four strands. The containing framework in this case can be simply light pieces of tubing let into the wooden framework, or very light iron pieces fastened thereto. Do not attempt to split up the rubber into more than two strands to each propeller. SECTION II.--OTHER FORMS OF MOTORS. § 18A. =Spring Motors.=--This question has already been dealt with more or less whilst dealing with rubber motors, and the superiority of the latter over the former pointed out. Rubber has a much greater superiority over steel or other springs, because in stretch-twisted rubber far more energy can be stored up weight for weight. One pound weight of elastic can be made to store up some 320 ft.-lb. of energy, and steel only some 65 lb. And in addition to this there is the question of gearing, involving extra weight and friction; that is, if flat steel springs similar to those used in clockwork mechanism be made use of, as is generally the case. The only instance in which such springs are of use is for the purpose of studying the effects of different distributions of weight on the model, and its effect on the balance of the machine; but effects such as this can be brought about without a change of motor. § 18B. A more efficient form of spring motor, doing away with gearing troubles, is to use a long spiral spring (as long as the rubber strands) made of medium-sized piano wire, similar in principle to those used in some roller-blinds, but longer and of thinner steel. The writer has experimented with such, as well as scores of other forms of spring motors, but none can compare with rubber. The long spiral form of steel spring is, however, much the best. § 18C. =Compressed Air Motors.=--This is a very fascinating form of motor, on paper, and appears at first sight the ideal form. It is so easy to write: "Its weight is negligible, and it can be provided free of cost; all that is necessary is to work a bicycle pump for as many minutes as the motor is desired to run. This stored-up energy can be contained in a mere tube, of aluminium or magnalium, forming the central rib of the machine, and the engine mechanism necessary for conveying this stored-up energy to the revolving propeller need weigh only a few ounces." Another writer recommends "a pressure of 300 lb." § 18D. A pneumatic drill generally works at about 80 lb. pressure, and when developing 1 horse-power, uses about 55 cubic ft. of free air per minute. Now if we apply this to a model aeroplane of average size, taking a reservoir 3 ft. long by 1½ in. internal diameter, made of magnalium, say--steel would, of course, be much better--the weight of which would certainly not be less than 4 oz., we find that at 80 lb. pressure such a motor would use 55/Horse Power (H.P.) cub. ft. per minute. Now 80 lb. is about 5½ atmospheres, and the cubical contents of the above motor some 63 cub. in. The time during which such a model would fly depends on the H.P. necessary for flight; but a fair allowance gives a flight of from 10 to 30 sec. I take 80 lb. pressure as a fair practical limit. § 18E. The pressure in a motor-car tyre runs from 40 to 80 lb., usually about 70 lb. Now 260 strokes are required with an ordinary inflator to obtain so low a pressure as 70 lb., and it is no easy job, as those who have done it know. § 19. Prior to 1893 Mr. Hargraves (of cellular kite fame) studied the question of compressed-air motors for model flying machines. His motor was described as a marvel of simplicity and lightness, its cylinder was made like a common tin can, the cylinder covers cut from sheet tin and pressed to shape, the piston and junk rings of ebonite. One of his receivers was 23-3/8 in. long, and 5·5 in. diameter, of aluminium plate 0·2 in. thick, 3/8 in. by 1/8 in. riveting strips were insufficient to make tight joints; it weighed 26 oz., and at 80 lb. water pressure one of the ends blew out, the fracture occurring at the bend of the flange, and not along the line of rivets. The receiver which was successful being apparently a tin-iron one; steel tubing was not to be had at that date in Sydney. With a receiver of this character, and the engine referred to above, a flight of 343 ft. was obtained, this flight being the best. (The models constructed by him were not on the aeroplane, but ornithoptere, or wing-flapping principle.) The time of flight was 23 _seconds_, with 54½ double vibrations of the engines. The efficiency of this motor was estimated to be 29 per cent. § 20. By using compressed air, and heating it in its passage to the cylinder, far greater efficiency can be obtained. Steel cylinders can be obtained containing air under the enormous pressure of 120 atmospheres.[19] This is practically liquid air. A 20-ft. cylinder weighs empty 23 lb. The smaller the cylinder the less the proportionate pressure that it will stand; and supposing a small steel cylinder, produced of suitable form and weight, and capable of withstanding with safety a pressure of from 300 to 600 lb. per sq. in., or from 20 to 40 atmospheres. The most economical way of working would be to admit the air from the reservoir directly to the motor cylinders; but this would mean a very great range in the initial working pressure, entailing not-to-be-thought-of weight in the form of multi-cylinder compound engines, variable expansion gear, etc. § 21. This means relinquishing the advantages of the high initial pressure, and the passing of the air through a reducing valve, whereby a constant pressure, say, of 90 to 150, according to circumstances, could be maintained. By a variation in the ratio of expansion the air could be worked down to, say, 30 lb. The initial loss entailed by the use of a reducing valve may be in a great measure restored by heating the air before using it in the motor cylinders; by heating it to a temperature of only 320°F., by means of a suitable burner, the volume of air is increased by one half, the consumption being reduced in the same proportion; the consumption of air used in this way being 24 lb. per indicated horse-power per hour. But this means extra weight in the form of fuel and burners, and what we gain in one way we lose in another. It is, of course, desirable that the motor should work at as low a pressure as possible, since as the store of air is used up the pressure in the reservoir falls, until it reaches a limit below which it cannot usefully be employed. The air then remaining is dead and useless, adding only to the weight of the aeroplane. § 22. From calculations made by the writer the _entire_ weight of a compressed-air model motor plant would be at least _one-third_ the weight of the aeroplane, and on a small scale probably one-half, and cannot therefore hold comparison with the _steam engine_ discussed in the next paragraph. In concluding these remarks on compressed-air motors, I do not wish to dissuade anyone from trying this form of motor; but they must not embark on experiments with the idea that anything useful or anything superior to results obtained with infinitely less expense by means of rubber can be brought to pass with a bicycle pump, a bit of magnalium tube, and 60 lb. pressure. § 22A. In Tatin's air-compressed motor the reservoir weighed 700 grammes, and had a capacity of 8 litres. It was tested to withstand a pressure of 20 atmospheres, but was worked only up to seven. The little engine attached thereto weighed 300 grammes, and developed a motive power of 2 kilogram-metres per second (_see_ ch. iii.). § 23. =Steam-Driven Motors.=--Several successful steam-engined model aeroplanes have been constructed, the most famous being those of Professor Langley. Having constructed over 30 modifications of rubber-driven models, and experimented with compressed air, carbonic-acid gas, electricity, and other methods of obtaining energy, he finally settled upon the steam engine (the petrol motor was not available at that time, 1893). After many months' work it was found that the weight could not be reduced below 40 lb., whilst the engine would only develop ½ H.P., and finally the model was condemned. A second apparatus to be worked by compressed air was tried, but the power proved insufficient. Then came another with a carbonic-acid gas engine. Then others with various applications of electricity and gas, etc., but the steam engine was found most suitable; yet it seemed to become more and more doubtful whether it could ever be made sufficiently light, and whether the desired end could be attained at all. The chief obstacle proved not to be with the engines, which were made surprisingly light after sufficient experiment. _The great difficulty was to make a boiler of almost no weight which would give steam enough._ § 24. At last a satisfactory boiler and engine were produced. The engine was of 1 to 1½ H.P., total weight (including moving parts) 26 oz. The cylinders, two in number, had each a diameter of 1¼ in., and piston stroke 2 in. The boiler, with its firegrate, weighed a little over 5 lb. It consisted of a continuous helix of copper tubing, 3/8 in. external diameter, the diameter of the coil being 3 in. altogether. Through the centre of this was driven the blast from an "Ælopile," a modification of the naphtha blow-torch used by plumbers, the flame of which is about 2000° F.[20] The pressure of steam issuing into the engines varied from 100 to 150 lb. per sq. in.; 4 lb. weight of water and about 10 oz. of naphtha could be carried. The boiler evaporated 1 lb. of water per minute. The twin propellers, 39 in. in diam., pitch 1¼, revolved from 800 to 1000 a minute. The entire aeroplane was 15 ft. in length, the aerofoils from tip to tip about 14 ft., and the total weight slightly less than 30 lb., of which _one-fourth was contained in the machinery_. Its flight was a little over half a mile in length, and of 1½ minutes' duration. Another model flew for about three-quarters of a mile, at a rate of about 30 miles an hour. It will be noted that engine, generator, etc., work out at about 7 lb. per H.P. Considerable advance has been made in the construction of light and powerful model steam engines since Langley's time, chiefly in connexion with model hydroplanes, and a pressure of from 500 to 600 lb. per sq. in. has been employed; the steam turbine has been brought to a high state of perfection, and it is now possible to make a model De Laval turbine of considerable power weighing almost next to nothing,[21] the real trouble, in fact the only one, being the steam generator. An economization of weight means a waste of steam, of which models can easily spend their only weight in five minutes. § 25. One way to economize without increased weight in the shape of a condenser is to use spirit (methylated spirit, for instance) for both fuel and boiler, and cause the exhaust from the engines to be ejected on to the burning spirit, where it itself serves as fuel. By using spirit, or some very volatile hydrocarbon, instead of water, we have a further advantage from the fact that such vaporize at a much lower temperature than water. § 26. When experimenting with an engine of the turbine type we must use a propeller of small diameter and pitch, owing to the very high velocity at which such engines run. Anyone, however, who is not an expert on such matters would do well to leave such motors alone, as the very highest technical skill, combined with many preliminary disappointments and trials, are sure to be encountered before success is attained. § 27. And the smaller the model the more difficult the problem--halve your aeroplane, and your difficulties increase anything from fourfold to tenfold. The boiler would in any case be of the flash type of either copper or steel tubing (the former for safety), with a magnalium container for the spirit, and a working pressure of from 150 to 200 lb. per sq. in. Anything less than this would not be worth consideration. § 28. Some ten months after Professor Langley's successful model flights (1896), experiments were made in France at Carquenez, near Toulon. The total weight of the model aeroplane in this case was 70 lb.; the engine power a little more than 1 H.P. Twin screws were used--_one in front and one behind_. The maximum velocity obtained was 40 miles per hour; but the length of run only 154 yards, and duration of flight only a few seconds. This result compares very poorly with Langley's distance (of best flight), nearly one mile, duration 1 min. 45 sec. The maximum velocity was greater--30 to 40 miles per hour. The total breadth of this large model was rather more than 6 metres, and the surface a little more than 8 sq. metres. § 29. =Petrol Motors.=--Here it would appear at first thought is the true solution of the problem of the model aeroplane motor. Such a motor has solved the problem of aerial locomotion, as the steam engine solved that of terrestrial and marine travel, both full sized and model; and if in the case of full sized machines, then why not models. [Illustration: FIG. 18.--MR. STANGER'S MODEL IN FULL FLIGHT.] [Illustration: FIG. 19.--MR. STANGER'S PETROL-DRIVEN MODEL AEROPLANE. (_Illustrations by permission from electros supplied by the "Aero."_)] § 30. The exact size of the smallest _working_ model steam engine that has been made I do not know,[22] but it is or could be surprisingly small; not so the petrol motor--not one, that is, that would _work_. The number of petrol motor-driven model aeroplanes that have actually flown is very small. Personally I only know of one, viz., Mr. D. Stanger's, exhibited at the aero exhibition at the Agricultural Hall in 1908. [Illustration: FIG. 20.--MR. STANGER'S MODEL PETROL ENGINE.] [Illustration: FIG. 21.--MR. STANGER'S MODEL PETROL ENGINE.] In Fig. 21 the motor is in position on the aeroplane. Note small carburettor. In Fig. 20 an idea of the size of engine may be gathered by comparing it with the ordinary sparking-plug seen by the side, whilst to the left of this is one of the special plugs used on this motor. (_Illustrations by permission from electros supplied by the "Aero."_) § 31. The following are the chief particulars of this interesting machine:--The engine is a four-cylinder one, and weighs (complete with double carburetter and petrol tank) 5½ lb., and develops 1¼ H.P. at 1300 revolutions per minute. [Illustration: FIG. 22.--ONE-CYLINDER PETROL MOTOR. (_Electro from Messrs. A.W. Gamage's Aviation Catalogue._)] The propeller, 29 in. in diam. and 36 in. in pitch, gives a static thrust of about 7 lb. The machine has a spread of 8 ft. 2 in., and is 6 ft. 10 in. in length. Total weight 21 lb. Rises from the ground when a speed of about 16 miles an hour is attained. A clockwork arrangement automatically stops the engine. The engine air-cooled. The cylinder of steel, cast-iron heads, aluminium crank-case, double float feed carburetter, ignition by single coil and distributor. The aeroplane being 7 ft. 6 in. long, and having a span 8 ft. § 32. =One-cylinder Petrol Motors.=--So far as the writer is aware no success has as yet attended the use of a single-cylinder petrol motor on a model aeroplane. Undoubtedly the vibration is excessive; but this should not be an insuperable difficulty. It is true it is heavier in proportion than a two-cylinder one, and not so efficient; and so far has not proved successful. The question of vibration on a model aeroplane is one of considerable importance. A badly balanced propeller even will seriously interfere with and often greatly curtail the length of flight. § 33. =Electric Motors.=--No attempt should on any account be made to use electric motors for model aeroplanes. They are altogether too heavy, apart even from the accumulator or source of electric energy, for the power derivable from them. To take an extreme case, and supposing we use a 2-oz. electric motor capable of driving a propeller giving a static thrust of 3 oz.,[23] on weighing one of the smallest size accumulators without case, etc., I find its weight is 4½ oz. One would, of course, be of no use; at least three would be required, and they would require practically short circuiting to give sufficient amperage (running them down, that is, in some 10 to 15 seconds). Total weight, 1 lb. nearly. Now from a _pound_ weight of rubber one could obtain a thrust of _pounds_, not ounces. For scale models not intended for actual flight, of course, electric motors have their uses. FOOTNOTES: [12] Also there is no necessity for gearing. [13] In his latest models the writer uses strands even three times and not twice as long, viz. fourteen strands 43 in. long. [14] This refers to 1/16 in. square sectioned rubber. [15] Of uniform breadth and thickness. [16] In practice I find not quite so high a proportion as this is always necessary. [17] Steel pinion wire is very suitable. [18] See Appendix. [19] As high a pressure as 250 atmospheres has been used. [20] There was a special pump keeping the water circulating rapidly through the boiler, the intense heat converting some of it into steam as it flowed. The making of this boiler alone consumed months of work; the entire machine taking a year to construct, with the best mechanical help available. [21] Model Steam Turbines. "Model Engineer" Series, No. 13, price 6_d._ [22] See Introduction, note to § 1. [23] The voltage, etc., is not stated. CHAPTER V. PROPELLERS OR SCREWS. § 1. The design and construction of propellers, more especially the former, is without doubt one of the most difficult parts of model aeroplaning. With elastic or spring driven models the problem is more complicated than for models driven by petrol or some vaporized form of liquid fuel; and less reliable information is to hand. The problem of _weight_, unfortunately, is of primary importance. We will deal with these points in due course; to begin with let us take:-- THE POSITION OF THE PROPELLER. In model aeroplanes the propeller is usually situated either in front or in the rear of the model; in the former case it is called a TRACTOR SCREW, i.e., it pulls instead of pushes. As to the merits of the two systems with respect to the tractor, there is, we know, in the case of models moving through water a distinct advantage in placing the propeller behind, and using a pushing or propulsive action, on account of the frictional "wake" created behind the boat, and which causes the water to flow after the vessel, but at a lesser velocity. In placing the propeller behind, we place it in such a position as to act upon and make use of this phenomenon, the effect of the propeller being to bring this following wake to rest. Theoretically a boat, model or otherwise, can be propelled with less horse-power than it can be towed. But with respect to aeroplanes, apart altogether from the difference of medium, there is _at present_ a very considerable difference of _form_, an aeroplane, model or otherwise, bearing at present but little resemblance to the hull of a boat. Undoubtedly there is a frictional wake in the case of aeroplanes, possibly quite as much in proportion as in the case of a boat, allowing for difference of medium. Admitting, then, that this wake does exist, it follows that a propulsive screw is better than a tractor. In a matter of this kind constructional considerations, or "ease of launching," and "ability to land without damage," must be given due weight. In the case of model aeroplanes constructional details incline the balance neither one way nor the other; but "ease in launching" and "ability to land without damage" weigh the balance down most decidedly in favour of a driving or propulsive screw. In the case of full-sized monoplanes constructional details had most to do with the use of tractors; but monoplanes are now being built with propulsive screws.[24] In the case of models, not models of full-sized machines, but actual model flyers, the writer considers propulsive screws much the best.[25] In no case should the propeller be placed in the centre of the model, or in such a position as to _shorten the strands of the elastic motor_, if good flights are desired. In the case of petrol or similar driven models the position of the propeller can be safely copied from actual well-recognised and successful full-sized machines. § 2. =The Number of Blades.=--Theoretically the number of blades does not enter into consideration. The mass of air dealt with by the propeller is represented by a cylinder of indefinite length, whose diameter is the same as that of the screw, and the rate at which this cylinder is projected to the rear depends theoretically upon the pitch and revolutions (per minute, say) of the propeller and not the number of blades. Theoretically one blade (helix incomplete) would be sufficient, but such a screw would not "balance," and balance is of primary importance; the minimum number of blades which can be used is therefore _two_. In marine models three blades are considered best, as giving a better balance. In the case of their aerial prototypes the question of _weight_ has again to be considered, and two blades is practically the invariable custom.[26] Here, again, constructional considerations again come to the fore, and in the case of wooden propellers one of two blades is of far more easy construction than one of three. By increasing the number of blades the "thrust" is, of course, more evenly distributed over a larger area, but the weight is considerably increased, and in models a greater advantage is gained by keeping down the weight than might follow from the use of more blades. § 3. =Fan versus Propeller.=--It must always be most carefully borne in mind that a fan (ventilating) and a propeller are not the same thing. Because many blades are found in practice to be efficient in the case of the former, it is quite wrong to assume that the same conclusion holds in the case of the latter. By increasing the number of blades the skin friction due to the resistance that has to be overcome in rotating the propeller through the air is added to. Moreover a fan is stationary, whilst a propeller is constantly _advancing_ as well as _rotating_ through the air. The action of a fan blower is to move a small quantity of air at a high velocity; whereas the action of a propeller is, or should be, to move _a large quantity of air at a small velocity_, for the function of a screw is to create thrust. Operating on a yielding fluid medium this thrust will evidently be in proportion to the mass of fluid moved, and also to the velocity at which it is put in motion. But the power consumed in putting this mass of fluid in motion is proportional to the mass and to the _square_ of the velocity at which it moves. From this it follows, as stated above, that in order to obtain a given thrust with the least loss of power, the mass of fluid acted on should be as large as possible, and the velocity imparted to it as little as possible. A fan requires to be so designed as to create a thrust when stationary (static thrust), and a propeller whilst moving through the air (dynamic thrust). § 4. =The Function of a Propeller= is to produce dynamic thrust; and the great advantage of the use of a propeller as a thrusting or propulsive agent is that its surface is always active. It has no _dead_ points, and its motion is continuous and not reciprocating, and it requires no special machinery or moving parts in its construction and operation. § 5. =The Pitch= of a propeller or screw is the linear distance a screw moves, backwards or forwards, in one complete revolution. This distance is purely a theoretical one. When, for instance, a screw is said to have a pitch of 1 ft., or 12 in., it means that the model would advance 1 ft. through the air for each revolution of the screw, provided that the propeller blade were mounted in _solid_ guides, like a nut on a bolt with one thread per foot. In a yielding fluid such as water or air it does not practically advance this distance, and hence occurs what is known as-- § 6. =Slip=, which may be defined as the distance which ought to be traversed, but which is lost through imperfections in the propelling mechanism; or it may be considered as power which should have been used in driving the model forward. In the case of a locomotive running on dry rails nothing is lost in slip, there being none. In the case of a steamer moored and her engines set going, or of an aeroplane held back prior to starting, all the power is used in slip, i.e. in putting the fluid in motion, and none is used in propulsion. Supposing the propeller on our model has a pitch of 1 ft., and we give the elastic motor 100 turns, theoretically the model should travel 100 ft. in calm air before the propeller is run down; no propeller yet designed will do this. Supposing the actual length 77 ft., 23 per cent. has been lost in "slip." For this to be actually correct the propeller must stop at the precise instant when the machine comes to ground. Taking "slip" into account, then-- _The speed of the model in feet per minute = pitch (in feet) × revolutions per minute -- slip (feet per minute)._ This slip wants to be made small--just how small is not yet known. If made too small then the propeller will not be so efficient, or, at any rate, such is the conclusion come to in marine propulsion, where it is found for the most economical results to be obtained that the slip should be from 10 to 20 per cent. In the case of aerial propellers a slip of 25 per cent. is quite good, 40 per cent. bad; and there are certain reasons for assuming that possibly about 15 per cent. may be the best. § 7. It is true that slip represents energy lost; but some slip is essential, because without slip there could be no "thrust," this same thrust being derived from the reaction of the volume of air driven backwards. The thrust is equal to-- _Weight of mass of air acted on per second × slip velocity in feet per second._ In the case of an aeroplane advancing through the air it might be thought that the thrust would be less. Sir Hiram Maxim found, however, as the result of his experiments that the thrust with a propeller travelling through the air at a velocity of 40 miles an hour was the same as when stationary, the r.p.m. remaining constant throughout. The explanation is that when travelling the propeller is continually advancing on to "undisturbed" air, the "slip" velocity is reduced, but the undisturbed air is equivalent to acting upon a greater mass of air. § 8. =Pitch Coefficient or Pitch Ratio.=--If we divide the pitch of a screw by its diameter we obtain what is known as pitch coefficient or ratio. The mean value of eighteen pitch coefficients of well-known full-sized machines works out at 0·62, which, as it so happens, is exactly the same as the case of the Farman machine propeller considered alone, this ratio varying from 0·4 to 1·2; in the case of the Wright's machine it is (probably) 1. The efficiency of their propeller is admitted on all hands. Their propeller is, of course, a slow-speed propeller, 450 r.p.m. The one on the Blériot monoplane (Blériot XI.) pitch ratio 0·4, r.p.m. 1350. In marine propulsion the pitch ratio is generally 1·3 for a slow-speed propeller, decreasing to 0·9 for a high-speed one. In the case of rubber-driven model aeroplanes the pitch ratio is often carried much higher, even to over 3. Mr. T.W.K. Clarke recommends a pitch angle of 45°, or less, at the tips, and a pitch ratio of 3-1/7 (with an angle of 45°). Within limits the higher the pitch ratio the better the efficiency. The higher the pitch ratio the slower may be the rate of revolution. Now in a rubber motor we do not want the rubber to untwist (run out) too quickly; with too fine a pitch the propeller "races," or does something remarkably like it. It certainly revolves with an abnormally high percentage of slip. And for efficiency it is certainly desirable to push this ratio to its limit; but there is also the question of the § 9. =Diameter.=--"The diameter (says Mr. T.W.K. Clarke) should be equal to one-quarter the span of the machine." If we increase the diameter we shall decrease the pitch ratio. From experiments which the writer has made he prefers a lower pitch ratio and increased diameter, viz. a pitch ratio of 1·5, and a diameter of one-third to even one-half the span, or even more.[27] Certainly not less than one-third. Some model makers indulge in a large pitch ratio, angle, diameter, and blade area as well, but such a course is not to be recommended. § 10. =Theoretical Pitch.=--Theoretically the pitch (from boss to tip) should at all points be the same; the boss or centre of the blade at right angles to the plane of rotation, and the angle decreasing as one approaches the tips. This is obvious when one considers that the whole blade has to move forward the same amount. In the diagrams Figs. 23 and 24 the tip A of the propeller travels a distance = 2 {pi} R every revolution. At a point D on the blade, distant _r_ from the centre, the distance is 2 {pi} _r_. In both instances the two points must advance a distance equal to the pitch, i.e. the distance represented by P O. [Illustration: FIG. 23.] [Illustration: FIG. 24. A O = 2 {pi} R; D O = 2 {pi} _r_.] A will move along A P, B along B P, and so on. The angles at the points A, B, C ... (Fig. 24), showing the angles at which the corresponding parts of the blade at A, B, C ... in Fig. 23 must be set in order that a uniform pitch may be obtained. § 11. If the pitch be not uniform then there will be some portions of the blade which will drag through the air instead of affording useful thrust, and others which will be doing more than they ought, putting air in motion which had better be left quiet. This uniform total pitch for all parts of the propeller is (as already stated) a decreasing rate of pitch from the centre to the edge. With a total pitch of 5 ft., and a radius of 4 ft., and an angle at the circumference of 6°, then the angle of pitch at a point midway between centre and circumference should be 12°, in order that the total pitch may be the same at all parts. § 12. =To Ascertain the Pitch of a Propeller.=--Take any point on one of the blades, and carefully measure the inclination of the blade at that point to the plane of rotation. If the angle so formed be about 19° (19·45),[28] i.e., 1 in 3, and the point 5 in. from the centre, then every revolution this point will travel a distance 2 {pi} _r_ = 2 × 22/7 × 5 = 31·34. Now since the inclination is 1 in 3,[29] the propeller will travel forward theoretically one-third of this distance, or 31·43/3 = 10·48 = 10½ in. approx. Similarly any other case may be dealt with. If the propeller have a uniform _constant angle_ instead of a uniform pitch, then the pitch may be calculated at a point about one-third the length of the blade from the tip. § 13. =Hollow-Faced Blades.=[30]--It must always be carefully borne in mind that a propeller is nothing more nor less than a particular form of aeroplane specially designed to travel a helical path. It should, therefore, be hollow faced and partake of the "stream line" form, a condition not fulfilled if the face of the blade be flat--such a surface cutting into the air with considerable shock, and by no means creating as little undesirable motion in the surrounding medium as possible. It must not be forgotten that a curved face blade has of necessity an increasing pitch from the cutting to the trailing edge (considering, of course, any particular section). In such a case the pitch is the _mean effective pitch_. § 14. =Blade Area.=--We have already referred to the fact that the function of a propeller is to produce dynamic thrust--to drive the aeroplane forward by driving the air backwards. At the same time it is most desirable for efficiency that the air should be set in motion as little as possible, this being so much power wasted; to obtain the greatest reaction or thrust the greatest possible volume of air should be accelerated to the smallest velocity. In marine engineering in slow-speed propellers (where cavitation[31] does not come in) narrow blades are usually used. In high-speed marine propellers (where cavitation is liable to occur) the projected area of the blades is sometimes as much as 0·6 of the total disk area. In the case of aerial propellers, where cavitation does not occur, or not unless the velocity be a very high one (1500 or more a minute), narrow blades are the best. Experiments in marine propulsion also show that the thrust depends more on the disk area than on the width of the blades. All the facts tend to show that for efficiency the blades of the propeller should be narrow, in order that the air may not be acted on for too long a time, and so put too much in motion, and the blades be so separated that one blade does not disturb the molecules of air upon which the next following one must act. Both in the case of marine and aerial propellers multiplicity of blades (i.e. increased blade area) tends to inefficiency of action, apart altogether from the question of weight and constructional difficulties. The question of increasing pitch in the case of hollow-faced blades, considered in the last paragraph, has a very important bearing on the point we are considering. To make a wide blade under such circumstances would be to soon obtain an excessive angle. In the case of a flat blade the same result holds, because the air has by the contact of its molecules with the "initial minimum width" been already accelerated up to its final velocity, and further area is not only wasted, but inimical to good flights, being our old bugbear "weight in excess." Requisite strength and stiffness, of course, set a limit on the final narrowness of the blades, apart from other considerations. § 15. The velocity with which the propeller is rotated has also an important bearing on this point; but a higher speed than 900 r.p.m. does not appear desirable, and even 700 or less is generally preferable.[32] In case of twin-screw propellers, with an angle at the tips of 40° to 45°, as low a velocity of 500 or even less would be still better.[33] § 16. =Shrouding.=--No improvement whatever is obtained by the use of any kind of shrouding or ring round the propeller tips, or by corrugating the surface of the propeller, or by using cylindrical or cone-shaped propeller chamber or any kind of air guide either before or after the propeller; allow it to revolve in as free an air-feed as possible, the air does not fly off under centrifugal force, but is powerfully sucked inwards in a well-designed propeller. [Illustration: FIG. 25. A TUBE OF AIR.] [Illustration: FIG. 26. A CYLINDER OF AIR.] § 17. =General Design.=--The propeller should be so constructed as to act upon a tube and not a "cylinder" of air. Many flying toys (especially the French ones) are constructed with propellers of the cylinder type. Ease of manufacture and the contention that those portions of the blades adjacent to the boss do little work, and a slight saving in weight, are arguments that can be urged in their favour. But all the central cut away part offers resistance in the line of travel, instead of exerting its proportionate propulsive power, and their efficiency is affected by such a practice. § 18. A good =Shape= for the blades[34] is rectangular with rounded corners; the radius of the circle for rounding off the corners may be taken as about one-quarter of the width of the blade. The shape is not _truly rectangular, for the width of this rectangular at (near) the boss should be one-half the width at the tip_. The thickness should diminish uniformly from the boss to the tip. (In models the thickness should be as little as is consistent with strength to keep down the weight). _The pitch uniform and large._ [Illustration: FIG. 27.--O T = 1/3 O P.] § 19. =The Blades, two in number=, and hollow faced--the maximum concavity being one-third the distance from the entering to the trailing edge; the ratio of A T to O P (the width) being 0·048 or 1 : 21, these latter considerations being founded on the analogy between a propeller and the aerofoil surface. (If the thickness be varied from the entering to the trailing edge the greatest thickness should be towards the former.) The convex surface of the propeller must be taken into account, in fact, it is no less important than the concave, and the entire surface must be given a true "stream line" form. [Illustration: FIG. 28.] [Illustration: FIG. 29.] If the entering and trailing edge be not both straight, but one be curved as in Fig. 28, then the straight edge must be made the _trailing_ edge. And if both be curved as in Fig. 29, then the _concave_ edge must be the trailing edge. § 19. =Propeller Design.=--To design a propeller, proceed as follows. Suppose the diameter 14 in. and the pitch three times the diameter, i.e. 52 in. (See Fig. 30.) Take one-quarter scale, say. Draw a centre line A B of convenient length, set of half the pitch 52 in. -- ¼ scale = 5¼ in. = C - D. Draw lines through C and D at right angles to C D. With a radius equal to half the diameter (i.e. in this case 1¾ in.) of the propeller, describe a semicircle E B F and complete the parallelogram F H G E. Divide the semicircle into a number of equal parts; twelve is a convenient number to take, then each division subtends an angle of 15° at the centre D. Divide one of the sides E G into the same number of equal parts (twelve) as shown. Through these points draw lines parallel to F E or H G. And through the twelve points of division on the semicircle draw lines parallel to F H or E G as shown. The line drawn through the successive intersections of these lines is the path of the tip of the blade through half a revolution, viz. the line H S O T E. S O T X gives the angle at the tip of the blades = 44°. Let the shape of the blade be rectangular with rounded corners, and let the breadth at the tip be twice that at the boss. Then the area (neglecting the rounded off corners) is 10½ sq. in. [Illustration: FIG. 30.--PROPELLER DESIGN. One quarter scale. Diameter 14 in. Pitch 52 in. Angle at tip 44°.] The area being that of a rectangle 7 in. × 1 in. = 7 sq. in. plus area of two triangles, base ½ in., height 7 in. Now area of triangle = half base × height. Therefore area of both triangles = ½ in. × 7 in. = 3½ sq. in. Now the area of the disc swept out by the propeller is {pi}/4 × (diam.)² ({pi} = 22/7) [Illustration: FIG. 31.--PROPELLER DESIGN. Scale one-eighth for A B and B C; but sections of blade are full-sized.] And if _d_ A _r_ = the "disc area ratio" we have (_d_ A _r_) × {pi}/4 × (14)² = area of blade = 10½, whence _d_ A _r_ = 0·07 about. [Illustration: FIG. 32.] [Illustration: FIG. 33.] In Fig. 31 set off A B equal to the pitch of the propeller (42 in.), one-eighth scale. Set off B C at right angles to A B and equal to {pi} × diameter = 22/7 × 14 = 44 in. to scale 5½ in. Divide B C into a convenient number of equal parts in the figure; five only are taken, D, E, F, G, H; join A D, A E, A F, A G, A H and produce them; mark off distances P O, S R, Y T ... equal to the width of the blade at these points (H P = H O; G S = G R ...) and sketch in the sections of blade as desired. In the figure the greatest concavity of the blade is supposed to be one-third the distances P O, S R ... from PS.... The concavity is somewhat exaggerated. The angles A H B, A G B, A F B ... represent the pitch angle at the points H, G, F ... of the blade. Similarly any other design may be dealt with; in a propeller of 14 in. diameter the diameter of the "boss" should not be more than 10/16 in. § 20. =Experiments with Propellers.=--The propeller design shown in Figs. 32 and 33, due to Mr. G. de Havilland,[35] is one very suitable for experimental purposes. A single tube passing through a T-shaped boss forms the arms. On the back of the metal blade are riveted four metallic clips; these clips being tightened round the arm by countersunk screws in the face of the blade. The tube and clips, etc., are all contained with the back covering of the blade, as shown in Fig. 35, if desired, the blade then practically resembling a wooden propeller. The construction, it will be noticed, allows of the blade being set at any angle, constant or otherwise; also the pitch can be constant or variable as desired, and any "shape" of propeller can be fitted. The advantage of being able to _twist_ the blade (within limits) on the axis is one not to be underestimated in experimental work. [Illustration: FIG. 34.--THE AUTHOR'S PROPELLER TESTING APPARATUS.] With a view to ascertain some practical and reliable data with respect to the _dynamic_, or actual thrust given when moving through free air at the velocity of actual travel, the author experimented with the apparatus illustrated in Figs. 34 and 35, which is so simple and obvious as to require scarcely any explanation. The wires were of steel, length not quite 150 ft., fitted with wire strainers for equalising tension, and absolutely free from "kinks." As shown most plainly in Fig. 35, there were two parallel wires sufficiently far apart for the action of one propeller not to affect the other. Calling these two wires A and B, and two propellers _x_ and _y_, then _x_ is first tried on A and _y_ on B. Results carefully noted. [Illustration: FIG. 35.--PROPELLER TESTING. Showing distance separating the two wires.] Then _x_ is tried on B and _y_ on A, and the results again carefully noted. If the results confirm one another, the power used in both cases being the same, well and good; if not, adjustments, etc., are made in the apparatus until satisfactory results are obtained. This was done when the propellers "raced" one against the other. At other times one wire only was made use of, and the time and distance traversed was noted in each case. Propellers were driven through smoke, and with silk threads tied to a light framework slightly larger than their disc area circumference. Results of great interest were arrived at. These results have been assumed in much that has been said in the foregoing paragraphs. [Illustration: FIG. 36.--ONE GROUP OF PROPELLERS TESTED BY THE AUTHOR.] Briefly put, these results showed:-- 1. The inefficiency of a propeller of the fan blower or of the static thrust type. 2. The advantage of using propellers having hollow-faced blades and large diameter. 3. That diameter was more useful than blade area, i.e. given a certain quantity (weight) of wood, make a long thin blade and not a shorter one of more blade area--blade area, i.e., as proportionate to its corresponding disc area. 4. That the propeller surface should be of true stream-line form. 5. That it should act on a cylinder and not tubes of air. 6. That a correctly designed and proportioned propeller was just as efficacious in a small size of 9 in. to 28 in. as a full-sized propeller on a full-sized machine. [Illustration: FIG. 37.--AN EFFICIENT PROPELLER, BUT RATHER HEAVY. Ball bearings, old and new. Note difference in sizes and weights. Propeller, 14 in. diam.; weight 36 grammes.] A propeller of the static-thrust type was, of course, "first off," sometimes 10 ft. or 12 ft. ahead, or even more; but the correctly designed propeller gradually gathered up speed and acceleration, just as the other fell off and lost it, and finally the "dynamic" finished along its corresponding wire far ahead of the "static," sometimes twice as far, sometimes six times. "Freak" propellers were simply not in it. [Illustration: FIG. 38.--"VENNA" PROPELLER. A 20 per cent. more efficient propeller than that shown in Fig. 41; 14 per cent. lighter; 6 per cent. better in dynamic thrust--14 in. diam.; weight 31 grammes.] Metal propellers of constant angle, as well as wooden ones of uniform (constant) pitch, were tested; the former gave good results, but not so good as the latter. The best angle of pitch (at the tip) was found to be from 20° to 30°. In all cases when the slip was as low as 25 per cent., or even somewhat less, nearly 20 per cent., a distinct "back current" of air was given out by the screw. This "slip stream," as it is caused, is absolutely necessary for efficiency. § 21. =Fabric-covered= screws did not give very efficient results; the only point in their use on model aeroplanes is their extreme lightness. Two such propellers of 6 in. diameter can be made to weigh less than 1/5 oz. the pair; but wooden propellers (built-up principle) have been made 5 in. diameter and 1/12 oz. in weight. § 22. Further experiments were made with twin screws mounted on model aeroplanes. In one case two propellers, both turning in the _same_ direction, were mounted (without any compensatory adjustment for torque) on a model, total weight 1½ lb. Diameter of each propeller 14 in.; angle of blade at tip 25°. The result was several good flights--the model (_see_ Fig. 49c) was slightly unsteady across the wind, that was all. In another experiment two propellers of same diameter, pitch, etc., but of shape similar to those shown in Figs. 28 and 29, were tried as twin propellers on the same machine. The rubber motors were of equal weight and strength. The model described circled to the right or left according to the position of the curved-shaped propeller, whether on the left or right hand, thereby showing its superiority in dynamic thrust. Various alterations were made, but always with the same result. These experiments have since been confirmed, and there seems no doubt that the double-curved shaped blade _is_ superior. (See Fig. 39.) § 23. =The Fleming-Williams Propeller.=--A chapter on propellers would scarcely be complete without a reference to the propeller used on a machine claiming a record of over a quarter of a mile. This form of propeller, shown in the group in Fig. 36 (top right hand), was found by the writer to be extremely deficient in dynamic thrust, giving the worst result of any shown there. [Illustration: FIG. 39.--CURVED DOUBLE PROPELLER. The most efficient type yet tested by the writer, when the blade is made hollow-faced. When given to the writer to test it was flat-faced on one side.] [Illustration: FIG. 40.--THE FLEMING-WILLIAMS MODEL.] It possesses large blade area, large pitch angle--more than 45° at the tip--and large diameter. These do not combine to propeller efficiency or to efficient dynamic thrust; but they do, of course, combine to give the propeller a very slow rotational velocity. Provided they give _sufficient_ thrust to cause the model to move through the air at a velocity capable of sustaining it, a long flight may result, not really owing to true efficiency on the part of the propellers,[36] but owing to the check placed on their revolutions per minute by their abnormal pitch angle, etc. The amount of rubber used is very great for a 10 oz. model, namely, 34 strands of 1/16 in. square rubber to each propeller, i.e. 68 strands in all. [Illustration: FIG. 41.--THE SAME IN FLIGHT. (_Reproduced by permission from "The Aero."_)] On the score of efficiency, when it is desired to make a limited number of turns give the longest flight (which is the problem one always has to face when using a rubber motor) it is better to make use of an abnormal diameter, say, more than half the span, and using a tip pitch angle of 25°, than to make use of an abnormal tip pitch 45° and more, and large blade area. In a large pitch angle so much energy is wasted, not in dynamic thrust, but in transverse upsetting torque. On no propeller out of dozens and dozens that I have tested have I ever found a tip-pitch of more than 35° give a good dynamic thrust; and for length of flight velocity due to dynamic thrust must be given due weight, as well as the duration of running down of the rubber motor. § 24. Of built up or carved out and twisted wooden propellers, the former give the better result; the latter have an advantage, however, in sometimes weighing less. FOOTNOTES: [24] _Note._--Since the above was written some really remarkable flights have been obtained with a 1 oz. model having two screws, one in front and the other behind. Equally good flights have also been obtained with the two propellers behind, one revolving in the immediate rear of the other. Flying, of course, with the wind, _weight_ is of paramount importance in these little models, and in both these cases the "single stick" can be made use of. _See also_ ch. iv., § 28. [25] _See also_ ch. viii., § 5. [26] Save in case of some models with fabric-covered propellers. Some dirigibles are now being fitted with four-bladed wooden screws. [27] Vide Appendix. [28] Vide Equivalent Inclinations--Table of. [29] One in 3 or 0·333 is the _sine_ of the angle; similarly if the angle were 30° the sine would be 0·5 or ½, and the theoretical distance travelled one-half. [30] _Flat-Faced Blades._--If the blade be not hollow-faced--and we consider the screw as an inclined plane and apply the Duchemin formula to it--the velocity remaining the same, the angle of maximum thrust is 35¼°. Experiments made with such screws confirm this. [31] Cavitation is when the high speed of the screw causes it to carry round a certain amount of the medium with it, so that the blades strike no undisturbed, or "solid," air at all, with a proportionate decrease in thrust. [32] In the Wright machine r.p.m. = 450; in Blériot XI. r.p.m. = 1350. [33] Such propellers, however, require a considerable amount of rubber. [34] But _see also_ § 22. [35] "Flight," March 10, 1910. (Illustration reproduced by permission.) [36] According to the author's views on the subject. CHAPTER VI. THE QUESTION OF SUSTENTATION THE CENTRE OF PRESSURE. § 1. Passing on now to the study of an aeroplane actually in the air, there are two forces acting on it, the upward lift due to the air (i.e. to the movement of the aeroplane supposed to be continually advancing on to fresh, undisturbed _virgin_ air), and the force due to the weight acting vertically downwards. We can consider the resultant of all the upward sustaining forces as acting at a single point--that point is called the "Centre of Pressure." Suppose A B a vertical section of a flat aerofoil, inclined at a small angle _a_ to the horizon C, the point of application of the resultant upward 'lift,' D the point through which the weight acts vertically downwards. Omitting for the moment the action of propulsion, if these two forces balance there will be equilibrium; but to do this they must pass through the same point, but as the angle of inclination varies, so does the centre of pressure, and some means must be employed whereby if C and D coincide at a certain angle the aeroplane will come back to the correct angle of balance if the latter be altered. In a model the means must be automatic. Automatic stability depends for its action upon the movement of the centre of pressure when the angle of incidence varies. When the angle of incidence increases the centre of pressure moves backwards towards the rear of the aerofoil, and vice versa. Let us take the case when steady flight is in progress and C and D are coincident, suppose the velocity of the wind suddenly to increase--increased lifting effect is at once the result, and the fore part of the machine rises, i.e. the angle of incidence increases and the centre of pressure moves back to some point in the rear of C D. The weight is now clearly trying to pull the nose of the aeroplane down, and the "lift" tending to raise the tail. The result being an alteration of the angle of incidence, or angle of attack as it is called, until it resumes its original position of equilibrium. A drop in the wind causes exactly an opposite effect. [Illustration: FIG. 42.] § 2. The danger lies in "oscillations" being set up in the line of flight due to changes in the position of the centre of pressure. Hence the device of an elevator or horizontal tail for the purpose of damping out such oscillations. § 3. But the aerofoil surface is not flat, owing to the increased "lift" given by arched surfaces, and a much more complicated set of phenomena then takes place, the centre of pressure moving forward until a certain critical angle of incidence is reached, and after this a reversal takes place, the centre of pressure then actually moving backwards. The problem then consists in ascertaining the most efficient aerocurve to give the greatest "lift" with the least "drift," and, having found it, to investigate again experimentally the movements of the centre of pressure at varying angles, and especially to determine at what angle (about) this "reversal" takes place. [Illustration: FIG. 43.] § 4. Natural automatic stability (the only one possible so far as models are concerned) necessitates permanent or a permanently recurring coincidence (to coin a phrase) of the centre of gravity and the centre of pressure: the former is, of course, totally unaffected by the vagaries of the latter, any shifting of which produces a couple tending to destroy equilibrium. § 5. As to the best form of camber (for full sized machine) possibly more is known on this point than on any other in the whole of aeronautics. In Figs. 44 and 45 are given two very efficient forms of cambered surfaces for models. [Illustration: FIG. 44.--AN EFFICIENT FORM OF CAMBER. B D Maximum Altitude. A C Chord. Ratio of B D: A C :: 1:17. A D 1/3 of A C.] [Illustration: FIG. 45.--ANOTHER EFFICIENT FORM. Ratio of B D to A C 1 to 17. AD rather more than ¼ of A C.] The next question, after having decided the question of aerocurve, or curvature of the planes, is at what angle to set the cambered surface to the line of flight. This brings us to the question of the-- § 6. =Dipping Front Edge.=--The leading or front edge is not tangential to the line of flight, but to a relative upward wind. It is what is known as the "cyclic up-current," which exists in the neighbourhood of the entering edge. Now, as we have stated before, it is of paramount importance that the aerofoil should receive the air with as little shock as possible, and since this up-current does really exist to do this, it must travel through the air with a dipping front edge. The "relative wind" (the only one with which we are concerned) _is_ thereby met tangentially, and as it moves onward through the air the cambered surface (or aerocurve) gradually transforms this upward trend into a downward wake, and since by Newton's law, "Action and reaction are equal and opposite," we have an equal and opposite upward reaction. We now know that the top (or convex side) of the cambered surface is practically almost as important as the underneath or concave side in bringing this result about. The exact amount of "dipping edge," and the exact angle at which the chord of the aerocurve, or cambered surface, should be set to the line of flight--whether at a positive angle, at no angle, or at a negative angle--is one best determined by experiment on the model in question. [Illustration: FIG. 46.] But _if at any angle, that angle either way should be a very small one_. If you wish to be very scientific you can give the underside of the front edge a negative angle of 5° to 7° for about one-eighth of the total length of the section, after that a positive angle, gradually increasing until you finally finish up at the trailing edge with one of 4°. Also, the form of cambered surface should be a paraboloid--not arc or arc of circles. The writer does not recommend such an angle, but prefers an attitude similar to that adopted in the Wright machine, as in Fig. 47. § 7. Apart from the attitude of the aerocurve: _the greatest depth of the camber should be at one-third of the length of the section from the front edge, and the total depth measured from the top surface to the chord at this point should not be more than one-seventeenth of the length of section_. § 8. It is the greatest mistake in model aeroplanes to make the camber otherwise than very slight (in the case of surfaced aerofoils the resistance is much increased), and aerofoils with anything but a _very slight_ arch are liable to be very unstable, for the aerocurve has always a decided tendency to "follow its own curve." [Illustration: FIG. 47.--ATTITUDE OF WRIGHT MACHINE.] The nature of the aerocurve, its area, the angle of inclination of its chord to the line of flight, its altitude, etc., are not the only important matters one must consider in the case of the aerofoil, we must also consider-- § 9. Its =Aspect Ratio=, i.e. the ratio of the span (length) of the aerofoil to the chord--usually expressed by span/chord. In the Farman machine this ratio is 5·4; Blériot, 4·3; Short, 6 to 7·5; Roe triplane, 7·5; a Clark flyer, 9·6. Now the higher the aspect ratio the greater should be the efficiency. Air escaping by the sides represents loss, and the length of the sides should be kept short. A broader aerofoil means a steeper angle of inclination, less stability, unnecessary waste of power, and is totally unsuited for a model--to say nothing of a full-sized machine. In models this aspect ratio may with advantage be given a higher value than in full-sized machines, where it is well known a practical safe constructional limit is reached long before theory suggests the limit. The difficulty consists in constructing models having a very high aspect ratio, and yet possessing sufficient strength and lightness for successful flight. It is in such a case as this where the skill and ingenuity of the designer and builder come in. It is this very question of aspect ratio which has given us the monoplane, the biplane, and the triplane. A biplane has a higher aspect ratio than a monoplane, and a triplane (see above) a higher ratio still. It will be noticed the Clark model given has a considerably higher aspect ratio, viz. 9·6. And even this can be exceeded. _An aspect ratio of_ 10:1 _or even_ 12:1 _should be used if possible._[37] § 10. =Constant or Varying Camber.=--Some model makers vary the camber of their aerofoils, making them almost flat in some parts, with considerable camber in others; the tendency in some cases being to flatten the central portions of the aerofoil, and with increasing camber towards the tips. In others the opposite is done. The writer has made a number of experiments on this subject, but cannot say he has arrived at any very decisive results, save that the camber should in all cases be (as stated before) very slight, and so far as his experiments do show anything, they incline towards the further flattening of the camber in the end portions of the aerofoil. It must not be forgotten that a flat-surfaced aerofoil, constructed as it is of more or less elastic materials, assumes a natural camber, more or less, when driven horizontally through the air. Reference has been made to a reversal of the-- § 11. =Centre of Pressure on Arched Surfaces.=--Wilbur Wright in his explanation of this reversal says: "This phenomenon is due to the fact that at small angles the wind strikes the forward part of the aerofoil surface on the upper side instead of the lower, and thus this part altogether ceases to lift, instead of being the most effective part of all." The whole question hangs on the value of the critical angle at which this reversal takes place; some experiments made by Mr. M.B. Sellers in 1906 (published in "Flight," May 14, 1910) place this angle between 16° and 20°. This angle is much above that used in model aeroplanes, as well as in actual full-sized machines. But the equilibrium of the model might be upset, not by a change of attitude on its part, but on that of the wind, or both combined. By giving (as already advised) the aerofoil a high aspect ratio we limit the travel of the centre of pressure, for a high aspect ratio means, as we have seen, a short chord; and this is an additional reason for making the aspect ratio as high as practically possible. The question is, is the critical angle really as high as Mr. Seller's experiments would show. Further experiments are much needed. FOOTNOTES: [37] Nevertheless some models with a very low aspect ratio make good flyers, owing to their extreme lightness. CHAPTER VII. MATERIALS FOR AEROPLANE CONSTRUCTION. § 1. The choice of materials for model aeroplane construction is more or less limited, if the best results are to be obtained. The lightness absolutely essential to success necessitates--in addition to skilful building and best disposition of the materials--materials of no undue weight relative to their strength, of great elasticity, and especially of great resilience (capacity to absorb shock without injury). § 2. =Bamboo.=--Bamboo has per pound weight a greater resilience than any other suitable substance (silk and rubber are obviously useless as parts of the _framework_ of an aeroplane). On full-sized machines the difficulty of making sufficiently strong connections and a liability to split, in the larger sizes, are sufficient reasons for its not being made more use of; but it makes an almost ideal material for model construction. The best part to use (split out from the centrepiece) is the strip of tough wood immediately below the hard glazed surface. For struts, spars, and ribs it can be used in this manner, and for the long strut supporting the rubber motor an entire tube piece should be used of the requisite strength required; for an ordinary rubber motor (one yard long), 30 to 50 strands, this should be a piece 3/8 in. in diameter, and weight about 5/8 oz. per ft. _Bamboo may be bent_ by either the "dry" heat from a spirit lamp or stove, or it may be steamed, the latter for preference, as there is no danger of "scorching" the fibres on the inside of the bend. When bent (as in the case of other woods) it should be bound on to a "former" having a somewhat greater curvature than the curve required, because when cool and dry it will be sure to "go back" slightly. It must be left on the former till quite dry. When bending the "tube" entire, and not split portions thereof, it should be immersed in very hot, or even boiling, water for some time before steaming. The really successful bending of the tube _en bloc_ requires considerable patience and care. Bamboo is inclined to split at the ends, and some care is required in making "joints." The ribs can be attached to the spars by lashing them to thin T strips of light metal, such as aluminium. Thin thread, or silk, is preferable to very thin wire for lashing purpose, as the latter "gives" too much, and cuts into the fibres of the wood as well. § 3. =Ash=, =Spruce=, =Whitewood= are woods that are also much used by model makers. Many prefer the last named owing to its uniform freedom from knots and ease with which it can be worked. It is stated 15 per cent. additional strength can be imparted by using hot size and allowing it to soak into the wood at an increase only of 3·7 per cent. of weight. It is less than half the weight of bamboo, but has a transverse rupture of only 7,900 lb. per sq. in. compared to 22,500 in the case of bamboo tubing (thickness one-eighth diameter) and a resilience per lb. weight of slightly more than one half. Some model makers advocate the use of =poplar= owing to its extreme lightness (about the same as whitewood), but its strength is less in the ratio of about 4:3; its resilience is very slightly more. It must be remembered that wood of the same kind can differ much as to its strength, etc., owing to what part of the tree it may have been cut from, the manner in which it may have been seasoned, etc. For model aeroplanes all wood used should have been at least a year in seasoning, and should be so treated when in the structure that it cannot absorb moisture. If we take the resilience of ash as 1, then (according to Haswell) relative resilience of beech is 0·86, and spruce 0·64. The strongest of woods has a weight when well seasoned of about 40 lb. per cub. ft. and a tenacity of about 10,000 lb. per sq. in. [Illustration: FIG. 47A.--"AEROPLANE ALMA." A very effective French Toy Monoplane.] § 4. =Steel.=--Ash has a transverse rupture of 14,300 lb. per sq. in., steel tubing (thickness = 1/30 its diameter) 100,000 lb. per sq. in. Ash weighs per cub. ft. 47 lb., steel 490. Steel being more than ten times as heavy as ash--but a transverse rupture stress seven times as high. Bamboo in tube form, thickness one-third of diameter, has a transverse rupture of 22,500 lb. per sq. in., and a weight of 55 lb. per cub. ft. Steel then is nine times as heavy as bamboo--and has a transverse rupture stress 4·4 times as great. In comparing these three substances it must be carefully borne in mind that lightness and strength are not the only things that have to be provided for in model aeroplane building; there is the question of _resistance_--we must offer as small a cross-section to moving through the air as possible. Now while ash or bamboo and certain other timbers may carry a higher load per unit of weight than steel, they will present about three to three and a half times the cross-section, and this produces a serious obstacle, while otherwise meeting certain requirements that are most desirable. Steel tubing of sufficiently small bore is not, so far as the writer knows, yet on the market in England. In France very thin steel tubes are made of round, oval, hexagon, etc., shape, and of accurate thickness throughout, the price being about 18s. a lb. Although suitable steel tubing is not yet procurable under ordinary circumstances, umbrella steel is. § 5. =Umbrella Section Steel= is a section 5/32 in. by 1/8 in. deep, 6 ft. long weighing 2·1 oz., and a section 3/32 in. across the base by 1/8 in. deep, 6 ft. long weighing 1·95 oz. It is often stated that umbrella ribs are too heavy--but this entirely depends on the length you make use of, in lengths of 25 in. for small aerofoils made from such lengths it is so; but in lengths of 48 in. (two such lengths joined together) the writer has used it with great success; often making use of it now in his larger models; the particular size used by him weighs 13½ grammes, to a length of 25 in. He has never had one of these aerofoils break or become kinked--thin piano wire is used to stay them and also for spars when employed--the front and ends of the aerofoil are of umbrella steel, the trailing edge of steel wire, comparatively thin, kept taut by steel wire stays. § 6. =Steel Wire.=--Tensile strength about 300,000 lb. per sq. in. For the aerofoil framework of small models and for all purposes of staying, or where a very strong and light tension is required, this substance is invaluable. Also for framework of light fabric covered propellers as well as for skids and shock absorber--also for hooks to hold the rubber motor strands, etc. No model is complete without it in some form or another. § 7. =Silk.=--This again is a _sine qua non_. Silk is the strongest of all organic substances for certain parts of aeroplane construction. It has, in its best form, a specific gravity of 1·3, and is three times as strong as linen, and twice as strong in the thread as hemp. Its finest fibres have a section of from 0·0010 to 0·0015 in diameter. It will sustain about 35,000 lb. per sq. in. of its cross section; and its suspended fibre should carry about 150,000 ft. of its own material. This is six times the same figure for aluminium, and equals about 75,000 lb. steel tenacity, and 50 more than is obtained with steel in the form of watch springs or wire. For aerofoil surface no substance can compare with it. But it must be used in the form of an "oiled" or specially treated silk. Several such are on the market. Hart's "fabric" and "radium" silk are perhaps the best known. Silk weighs 62 lb. per cub. ft., steel has, we have seen, 490 lb., thus paying due regard to this and to its very high tensile strength it is superior to even steel wire stays. § 8. =Aluminium and Magnalium.=--Two substances about which a great deal has been heard in connection with model aeroplaning; but the writer does not recommend their use save in the case of fittings for scale models, not actual flyers, unless especially light ones meant to fly with the wind. Neither can compare with steel. Steel, it is true, is three times as heavy as aluminium, but it has four or five times its strength; and whereas aluminium and magnalium may with safety be given a permissible breaking strength of 60 per cent. and 80 per cent. respectively, steel can easily be given 80 per cent. Being also less in section, resistance to air travel is again less as in the case of wood. In fact, steel scores all round. Weight of magnalium : weight of aluminium :: 8:9. § 9. =Alloys.=--During recent years scores, hundreds, possibly thousands of different alloys have been tried and experimented on, but steel still easily holds its own. It is no use a substance being lighter than another volume for volume, it must be _lighter and stronger weight for weight_, to be superior for aeronautical purpose, and if the difference be but slight, question of _bulk_ may decide it as offering _less resistance_. § 10. =Sheet Ebonite.=--This substance is sometimes useful for experiments with small propellers, for it can be bent and moulded in hot water, and when cold sets and keeps its shape. _Vulcanized fibre_ can be used for same purpose. _Sheet celluloid_ can be used in the same way, but in time it becomes brittle and shrinks. _Mica_ should be avoided. _Jointless cane_ in various sizes is a very useful material--the main aerofoil can be built of it, and it is useful for skids, and might be made more use of than it is.[38] _Three ply wood_, from 1/50 in. in thickness, is now on the market. Four or five ply wood can also be obtained. To those desiring to build models having wooden aerofoils such woods offer the advantage of great strength and extreme lightness. Referring to Table V. (Timber) at the end of the book, apparently the most suitable wood is Lombardy poplar; but its light weight means increased bulk, i.e. additional air resistance. Honduras mahogany is really a better all-round wood, and beech is not far behind. Resilience is an important factor. Ash heads the list; but mahogany's factor is also good, and in other respects superior. Lombardy poplar ought to be a very good wood for propellers, owing to its lightness and the ease with which it can be worked. _Hollow reeds_, and even _porcupine quills_, have been pressed into the service of the model maker, and owing to their great strength and extreme lightness, more especially the latter, are not without their uses. FOOTNOTES: [38] The chief advantage of cane--its want of stiffness, or facility in bending--is for some parts of the machine its chief disadvantage, where stiffness with resilience is most required. CHAPTER VIII. HINTS ON THE BUILDING OF MODEL AEROPLANES. § 1. The chief difficulty in the designing and building of model aeroplanes is to successfully combat the conflicting interests contained therein. Weight gives stability, but requires extra supporting surface or a higher speed, i.e. more power, i.e. more weight. Inefficiency in one part has a terrible manner of repeating itself; for instance, suppose the aerofoil surface inefficient--badly designed--this means more resistance; more resistance means more power, i.e. weight, i.e. more surface, and so on _ad infinitum_. It is because of circumstances like the above that it is so difficult to _design_ really good and efficient flying models; the actual building of them is not so difficult, but few tools are required, none that are expensive or difficult to use. In the making of any particular model there are special points that require special attention; but there are certain general rules and features which if not adhered to and carefully carried out, or as carefully avoided, will cause endless trouble and failure. § 2. In constructing a model aeroplane, or, indeed, any piece of aerial apparatus, it is very important not to interrupt the continuity of any rib, tube, spar, etc., by drilling holes or making too thinned down holding places; if such be done, additional strength by binding (with thread, not wire), or by slipping a small piece of slightly larger tube over the other, must be imparted to the apparatus. § 3. Begin by making a simple monoplane, and afterwards as you gain skill and experience proceed to construct more elaborate and scientific models. § 4. Learn to solder--if you do not know how to--it is absolutely essential. § 5. Do not construct models (intended for actual flight) with a tractor screw-main plane in front and tail (behind). Avoid them as you would the plague. Allusion has already been made in the Introduction to the difficulty of getting the centre of gravity sufficiently forward in the case of Blériot models; again with the main aerofoil in front, it is this aerofoil and not the balancing elevator, or tail, that _first_ encounters the upsetting gust, and the effect of such a gust acting first on the larger surface is often more than the balancer can rectify in time to avert disaster. The proper place for the propeller is behind, in the wake of the machine. If the screw be in front the backwash from it strikes the machine and has a decidedly retarding action. It is often contended that it drives the air at an increased velocity under (and over) the main aerofoil, and so gives a greater lifting effect. But for proper lifting effect which it can turn without effort into air columns of proper stream line form what the aerofoil requires is undisturbed air--not propeller backwash. The rear of the model is the proper place for the propeller, in the centre of greatest air disturbance; in such a position it will recover a portion of the energy lost in imparting a forward movement to the air, caused by the resistance, the model generally running in such air--the slip of the screw is reduced to a corresponding degree--may even vanish altogether, and what is known as negative slip occur. § 6. Wooden or metal aerofoils are more efficient than fabric covered ones. But they are only satisfactory in the smaller sizes, owing, for one thing, to the smash with which they come to the ground. This being due to the high speed necessary to sustain their weight. For larger-sized models fabric covered aerofoils should be used. § 7. As to the shape of such, only three need be considered--the (_a_) rectangular, (_b_) the elongated ellipse, (_c_) the chamfered rear edge. [Illustration: FIG. 48.--(_a_), (_b_), (_c_).] § 8. The stretching of the fabric on the aerofoil framework requires considerable care, especially when using silk. It is quite possible, even in models of 3 ft. to 4 ft. spread, to do without "ribs," and still obtain a fairly correct aerocurve, if the material be stretched on in a certain way. It consists in getting a correct longitudinal and transverse tension. We will illustrate it by a simple case. Take a piece of thickish steel pianoforte wire, say, 18 in. long, bend it round into a circle, allowing ½ in. to 1 in. to overlap, tin and solder, bind this with soft very thin iron wire, and again solder (always use as little solder as possible). Now stitch on to this a piece of nainsook or silk, deforming the circle as you do so until it has the accompanying elliptical shape. The result is one of double curvature; the transverse curve (dihedral angle) can be regulated by cross threads or wires going from A to B and C to D. [Illustration: FIG. 49.] [Illustration: FIG. 49A.--MR. T.W.K. CLARKE'S 1 OZ. MODEL.] The longitudinal curve on the camber can be regulated by the original tension given to it, and by the manner of its fixing to the main framework. Suitable wire projections or loops should be bound to it by wire, and these fastened to the main framework by binding with _thin_ rubber cord, a very useful method of fastening, since it acts as an excellent shock absorber, and "gives" when required, and yet possesses quite sufficient practical rigidity. § 9. Flexible joints are an advantage in a biplane; these can be made by fixing wire hooks and eyes to the ends of the "struts," and holding them in position by binding with silk or thread. Rigidity is obtained by use of steel wire stays or thin silk cord. [Illustration: FIG. 49B.--MR. T.W.K. CLARKE'S 1 OZ. MODEL. Showing the position of C. of G., or point of support.] § 10. Owing to the extra weight and difficulties of construction on so small a scale it is not desirable to use "double surface" aerofoils except on large size power-driven models. § 11. It is a good plan not to have the rod or tube carrying the rubber motor connected with the outrigger carrying the elevator, because the torque of the rubber tends to twist the carrying framework, and interferes with the proper and correct action of the elevator. If it be so connected the rod must be stayed with piano wire, both longitudinally (to overcome the pull which we know is very great), and also laterally, to overcome the torque. [Illustration: FIG. 49C.--A LARGE MODEL AEROPLANE. Shown without rubber or propellers. Designed and constructed by the writer. As a test it was fitted with two 14 in. propellers revolving in the _same_ direction, and made some excellent flights under these conditions, rolling slightly across the wind, but otherwise keeping quite steady. Total weight, 1½ lb.; length, 6 ft.; span of main aerofoil, 5 ft. Constructed of bamboo, cane, and steel wire. Front skids steel wire. Back skids cane. Aerofoil covering nainsook.] § 12. Some builders place the rubber motor above the rod, or bow frame carrying the aerofoils, etc., the idea being that the pull of the rubber distorts the frame in such a manner as to "lift" the elevator, and so cause the machine to rise rapidly in the air. This it does; but the model naturally drops badly at the finish and spoils the effect. It is not a principle that should be copied. [Illustration: FIG. 49D.--A VERY LIGHT WEIGHT MODEL. Constructed by the author. Provided with twin propellers of a modified Fleming-Williams type. This machine flew well when provided with an abnormal amount of rubber, owing to the poor dynamic thrust given by the propellers.] § 13. In the Clarke models with the small front plane, the centre of pressure is slightly in front of the main plane. The balancing point of most models is generally slightly in front, or just within the front edge of the main aerofoil. The best plan is to adjust the rod carrying the rubber motor and propeller until the best balance is obtained, then hang up the machine to ascertain the centre of gravity, and you will have (approximately) the centre of pressure. [Illustration: FIG. 49E.--USEFUL FITTINGS FOR MODELS. 1. Rubber tyred wheels. 2. Ball-bearing steel axle shafts. 3. Brass wire strainers with steel screws; breaking strain 200 lb. 4. Magnalium tubing. 5. Steel eyebolt. 6. Aluminium "T" joint. 7. Aluminium "L" piece. 8. Brass brazed fittings. 9. Ball-bearing thrust. 10. Flat aluminium "L" piece. (_The above illustrations taken (by permission) from Messrs. Gamage's catalogue on Model Aviation._)] § 14. The elevator (or tail) should be of the non-lifting type--in other words, the entire weight should be carried by the main aerofoil or aerofoils; the elevator being used simply as a balancer.[39] If the machine be so constructed that part of the weight be carried by the elevator, then either it must be large (in proportion) or set up at a large angle to carry it. Both mean considerably more resistance--which is to be avoided. In practice this means the propeller being some little distance in rear of the main supporting surface. [Illustration: FIG. 49F.--USEFUL FITTINGS FOR MODELS. 11. Aluminium ball thrust and racket. 12. Ball-bearing propeller, thrust, and stay. (_The above illustrations taken (by permission) from Messrs. Gamage's catalogue on Model Aviation._)] § 15. In actual flying models "skids" should be used and not "wheels"; the latter to be of any real use must be of large diameter, and the weight is prohibitive. Skids can be constructed of cane, imitation whalebone, steel watch or clock-spring, steel pianoforte wire. Steel mainsprings are better than imitation whalebone, but steel pianoforte wire best of all. For larger sized models bamboo is also suitable, as also ash or strong cane. § 16. Apart from or in conjunction with skids we have what are termed "shock absorbers" to lessen the shock on landing--the same substances can be used--steel wire in the form of a loop is very effectual; whalebone and steel springs have a knack of snapping. These shock absorbers should be so attached as to "give all ways" for a part side and part front landing as well as a direct front landing. For this purpose they should be lashed to the main frame by thin indiarubber cord. § 17. In the case of a biplane model the "gap" must not be less than the "chord"--preferably greater. In a double monoplane (of the Langley type) there is considerable "interference," i.e. the rear plane is moving in air already acted on by the front one, and therefore moving in a downward direction. This means decreased efficiency. It can be overcome, more or less, by varying the dihedral angle at which the two planes are set; but cannot be got rid of altogether, or by placing them far apart. In biplanes not possessing a dihedral angle--the propeller can be placed _slightly_ to one side--in order to neutralise the torque of the propeller--the best portion should be found by experiment--unless the pitch be very large; with a well designed propeller this is not by any means essential. If the propeller revolve clockwise, place it towards the right hand of the machine, and vice versa. § 18. In designing a model to fly the longest possible distance the monoplane type should be chosen, and when desiring to build one that shall remain the longest time in the air the biplane or triplane type should be adopted.[40] For the longest possible flight twin propellers revolving in opposite directions[41] are essential. To take a concrete case--one of the writer's models weighed complete with a single propeller 8½ oz. It was then altered and fitted with two propellers (same diameter and weight); this complete with double rubber weighed 10¼ oz. The advantage double the power. Weight increased only 20 per cent., resistance about 10 per cent., total 30 per cent. Gain 70 per cent. Or if the method of gearing advocated (see Geared Motors) be adopted then we shall have four bunches of rubber instead of two, and can thereby obtain so many more turns.[42] The length of the strands should be such as to render possible at least a thousand turns. The propellers should be of large diameter and pitch (not less than 35° at the tips), of curved shape, as advocated in § 22 ch. v.; the aerofoil surface of as high an aspect ratio as possible, and but slight camber if any; this is a very difficult question, the question of camber, and the writer feels bound to admit he has obtained as long flights with surfaces practically flat, but which do, of course, camber slightly in a suitable wind, as with stiffer cambered surfaces. Wind cambered surfaces are, however, totally unsuitable in gusty weather, when the wind has frequently a downward trend, which has the effect of cambering the surface the wrong way about, and placing the machine flat on the ground. Oiled or specially prepared silk of the lightest kind should be used for surfacing the aerofoils. Some form of keel, or fin, is essential to assist in keeping the machine in a straight course, combined with a rudder and universally jointed elevator. The manner of winding up the propellers has already been referred to (_see_ chap. iii., § 9). A winder is essential. Another form of aerofoil is one of wood (as in Clarke's flyers) or metal, such a machine relying more on the swiftness of its flight than on its duration. In this the gearing would possibly not be so advantageous--but experiment alone could decide. The weight of the machine would require to be an absolute minimum, and everything not absolutely essential omitted. It is quite possible to build a twin-screw model on one central stick alone; but the isosceles triangular form of framework, with two propellers at the base corners, and the rubber motors running along the two sides and terminating at the vertex, is preferred by most model makers. It entails, of course, extra weight. A light form of skid, made of steel pianoforte wire, should be used. As to the weight and size of the model, the now famous "one-ouncers" have made some long flights of over 300 yards[43]; but the machine claiming the record, half a mile,[44] weighs about 10 oz. And apart from this latter consideration altogether the writer is inclined to think that from 5 oz. to 10 oz. is likely to prove the most suitable. It is not too large to experiment with without difficulty, nor is it so small as to require the skill of a jeweller almost to build the necessary mechanism. The propeller speed has already been discussed (_see_ ch. v., § 15). The model will, of course, be flown with the wind. The _total_ length of the model should be at least twice the span of the main aerofoil. FOOTNOTES: [39] This is a good plan--not a rule. Good flying models can, of course, be made in which this does not hold. [40] This is in theory only: in practice the monoplane holds both records. [41] The best position for the propellers appears to be one in front and one behind, when extreme lightness is the chief thing desired. [42] Because the number of strands of rubber in each bunch will be much less. [43] Mr. Burge Webb claims a record of 500 yards for one of his. [44] Flying, of course, with the wind. _Note._--In the "Model Engineer" of July 7, 1910, will be found an interesting account (with illustrations) of Mr. W.G. Aston's 1 oz. model, which has remained in the air for over a minute. CHAPTER IX. THE STEERING OF THE MODEL. § 1. Of all the various sections of model aeroplaning that which is the least satisfactory is the above. The torque of the propeller naturally exerts a twisting or tilting effect upon the model as a whole, the effect of which is to cause it to fly in (roughly speaking) a circular course, the direction depending on whether the pitch of the screw be a right or left handed one. There are various devices by which the torque may be (approximately) got rid of. § 2. In the case of a monoplane, by not placing the rod carrying the rubber motor in the exact centre of the main aerofoil, but slightly to one side, the exact position to be determined by experiment. In a biplane the same result is obtained by keeping the rod in the centre, but placing the bracket carrying the bearing in which the propeller shaft runs at right angles horizontally to the rod to obtain the same effect. § 3. The most obvious solution of the problem is to use _two_ equal propellers (as in the Wright biplane) of equal and opposite pitch, driven by two rubber motors of equal strength. Theoretically this idea is perfect. In practice it is not so. It is quite possible, of course, to use two rubber motors of an equal number of strands (equality should be first tested by _weighing_). It should be possible to obtain two propellers of equal and opposite pitch, etc., and it is also possible to give the rubber motors the same number of turns. In practice one is always wound up before the other. This is the first mistake. They should be wound up _at the same time_, using a double winder made for the purpose. The fact that this is _not_ done is quite sufficient to give an unequal torsion. The friction in both cases must also be exactly equal. Both propellers must be released at exactly the same instant. Supposing _all_ these conditions fulfilled (in practice they never are), supposing also the propellers connected by gearing (prohibitive on account of the weight), and the air quite calm (which it never is), then the machine should and undoubtedly would _fly straight_. For steering purposes by winding up one propeller _many more times_ than the other, the aeroplane can generally speaking be steered to the right or left; but from what I have both seen and tried twin-screw model aeroplanes are _not_ the success they are often made out to be, and they are much more troublesome to deal with, in spite of what some say to the contrary. The solution of the problem of steering by the use of two propellers is only partially satisfactory and reliable, in fact, it is no solution at all.[45] The torque of the propeller and consequent tilting of the aeroplane is not the only cause at work diverting the machine from its course. § 4. As it progresses through the air it is constantly meeting air currents of varying velocity and direction, all tending to make the model deviate more or less from its course; the best way, in fact, the only way, to successfully overcome such is by means of _speed_, by giving the aeroplane a high velocity, not of ten or twelve to fifteen miles an hour, as is usual in built up fabric-covered aerofoils, but a velocity of twenty to thirty miles an hour, attainable only in models (petrol or steam driven) or by means of wooden or metal aerofoils. § 5. Amongst devices used for horizontal steering are vertical "FINS." These should be placed in the rear above the centre of gravity. They should not be large, and can be made of fabric tightly stretched over a wire frame, or of a piece of sheet magnalium or aluminium, turning on a pivot at the front edge, adjustment being made by simply twisting the fin round to the desired angle. As to the size, think of rudder and the size of a boat, but allow for the difference of medium. The frame carrying the pivot and fin should be made to slide along the rod or backbone of the model in order to find the most efficient position. § 6. Steering may also be attempted by means of little balancing tips, or ailerons, fixed to or near the main aerofoil, and pivoted (either centrally or otherwise) in such a manner that they can be rotated one in one direction (tilted) and the other in the other (dipped), so as to raise one side and depress the other. § 7. The model can also be steered by giving it a cant to one side by weighting the tip of the aerofoil on that side on which it is desired it should turn, but this method is both clumsy and "weighty." § 8. Another way is by means of the elevator; and this method, since it entails no additional surfaces entailing extra resistance and weight, is perhaps the most satisfactory of all. It is necessary that the elevator be mounted on some kind of universal joint, in order that it may not only be "tipped" or "dipped," but also canted sideways for horizontal steering. § 9. A vertical fin in the rear, or something in the nature of a "keel," i.e. a vertical fin running down the backbone of the machine, greatly assists this movement. If the model be of the tractor screw and tail (Blériot) type, then the above remarks _re_ elevator apply _mutatis mutandis_ to the tail. § 10. It is of the most vital importance that the propeller torque should be, as far as possible, correctly balanced. This can be tested by balancing the model transversely on a knife edge, winding up the propeller, and allowing it to run down, and adjusting matters until the torque and compensatory apparatus balance. As the torque varies the mean should be used. In the case of twin propellers, suspend the model by its centre of gravity, wind up the propellers, and when running down if the model is drawn forward without rotation the thrust is equal; if not adjustment must be made till it does. The easiest way to do this _may_ be by placing one propeller, the one giving the greater thrust, slightly nearer the centre. In the case of two propellers rotating in opposite directions (by suitable gearing) on the common centre of two axes, one of the axes being, of course, hollow, and turning on the other--the rear propeller working in air already driven back by the other will require a coarser pitch or larger diameter to be equally efficient. FOOTNOTE: [45] These remarks apply to rubber driven motors. In the case of two-power driven propellers in which the power was automatically adjusted, say, by a gyroscope as in the case of a torpedo--and the _speed_ of each propeller varied accordingly--the machine could, of course, be easily steered by such means; but the model to carry such power and appliances would certainly weigh from 40 lb. to 60 lb. CHAPTER X. THE LAUNCHING OF THE MODEL. § 1. Generally speaking, the model should be launched into the air _against the wind_. § 2. It should (theoretically) be launched into the air with a velocity equal to that with which it flies. If it launch with a velocity in excess of that it becomes at once unstable and has to "settle down" before assuming its normal line of flight. If the velocity be insufficient, it may be unable to "pick up" its requisite velocity in time to prevent its falling to the ground. Models with wooden aerofoils and a high aspect ratio designed for swift flying, such as the well-known Clarke flyers, require to be practically "hurled" into the air. Other fabric-covered models capable of sustentation at a velocity of 8 to 10 miles an hour, may just be "released." § 3. Light "featherweight" models designed for long flights when travelling with the wind should be launched with it. They will not advance into it--if there be anything of a breeze--but, if well designed, just "hover," finally sinking to earth on an even keel. Many ingenious pieces of apparatus have been designed to mechanically launch the model into the air. Fig. 50 is an illustration of a very simple but effective one. § 4. For large size power-driven models, unless provided with a chassis and wheels to enable them to run along and rise from the ground under their own power, the launching is a problem of considerable difficulty. § 5. In the case of rubber-driven models desired to run along and rise from the ground under their own power, this rising must be accomplished quickly and in a short space. A model requiring a 50 ft. run is useless, as the motor would be practically run out by that time. Ten or twelve feet is the limit; now, in order to rise quickly the machine must be light and carry considerable surface, or, in other words, its velocity of sustentation must be a low one. [Illustration: FIG. 50.--MR. POYNTER'S LAUNCHING APPARATUS. (_Reproduced by permission from the "Model Engineer."_)] § 6. It will not do to tip up the elevator to a large angle to make it rise quickly, because when once off the ground the angle of the elevator is wrong for actual flight and the model will probably turn a somersault and land on its back. I have often seen this happen. If the elevator be set at an increased angle to get it to rise quickly, then what is required is a little mechanical device which sets the elevator at its proper flight angle when it leaves the ground. Such a device does not present any great mechanical difficulties; and I leave it to the mechanical ingenuity of my readers to devise a simple little device which shall maintain the elevator at a comparatively large angle while the model is on the ground, but allowing of this angle being reduced when free flight is commenced. § 7. The propeller most suitable to "get the machine off the ground" is one giving considerable statical thrust. A small propeller of fine pitch quickly starts a machine, but is not, of course, so efficient when the model is in actual flight. A rubber motor is not at all well adapted for the purpose just discussed. § 8. Professor Kress uses a polished plank (down which the models slip on cane skids) to launch his models. § 9. When launching a twin-screw model the model should be held by each propeller, or to speak more correctly, the two brackets holding the bearings in which the propeller shafts run should be held one in each hand in such a way, of course, as to prevent the propellers from revolving. Hold the machine vertically downwards, or, if too large for this, allow the nose to rest slightly on the ground; raise (or swing) the machine up into the air until a little more than horizontal position is attained, and boldly push the machine into the air (moving forward if necessary) and release both brackets and screws simultaneously.[46] § 10. In launching a model some prefer to allow the propellers to revolve for a few moments (a second, say) _before_ actually launching, contending that this gives a steadier initial flight. This is undoubtedly the case, see note on page 111. § 11. In any case, unless trying for a height prize, do not point the nose of the machine right up into the air with the idea that you will thereby obtain a better flight. Launch it horizontally, or at a very small angle of inclination. When requiring a model to run along a field or a lawn and rise therefrom this is much facilitated by using a little strip of smooth oilcloth on which it can run. Remember that swift flying wooden and metal models require a high initial velocity, particularly if of large size and weight. If thrown steadily and at the proper angle they can scarcely be overthrown. FOOTNOTE: [46] Another and better way--supposing the model constructed with a central rod, or some suitable holdfast (this should be situated at the centre of gravity of the machine) by which it can be held in one hand--is to hold the machine with both hands above the head, the right hand grasping it ready to launch it, and the left holding the two propellers. Release the propellers and allow them a brief interval (about half a second) to start. Then launch boldly into the air. The writer has easily launched 1½ lb. models by this means, even in a high wind. Never launch a model by one hand only. CHAPTER XI. HELICOPTER MODELS. § 1. There is no difficulty whatever about making successful model helicopters, whatever there may be about full-sized machines. § 2. The earliest flying models were helicopters. As early as 1796 Sir George Cayley constructed a perfectly successful helicopter model (see ch. iii.); it should be noticed the screws were superimposed and rotated in opposite directions. § 3. In 1842 a Mr. Phillips constructed a successful power-driven model helicopter. The model was made entirely of metal, and when complete and charged weighed 2 lb. It consisted of a boiler or steam generator and four fans supported between eight arms. The fans had an inclination to the horizon of 20°, and through the arms the steam rushed on the principle of Hero's engines (Barker's Mill Principle probably). By the escape of steam from the arms the fans were caused to revolve with immense energy, so much so that the model rose to an immense altitude and flew across two fields before it alighted. The motive power employed was obtained from the combustion of charcoal, nitre and gypsum, as used in the original fire annihilator; the products of combustion mixing with water in the boiler and forming gas-charged steam, which was delivered at high pressure from the extremities of the eight arms.[47] This model and its flight (fully authenticated) is full of interest and should not be lost sight of, as in all probability being the first model actuated by steam which actually flew. The helicopter is but a particular phase of the aeroplane. § 4. The simplest form of helicopter is that in which the torque of the propeller is resisted by a vertical loose fabric plane, so designed as itself to form a propeller, rotating in the opposite direction. These little toys can be bought at any good toy shop from about 6_d._ to 1_s._ Supposing we desire to construct a helicopter of a more ambitious and scientific character, possessing a vertically rotating propeller or propellers for horizontal propulsion, as well as horizontally rotating propellers for lifting purposes. [Illustration: FIG. 51.--INCORRECT WAY OF ARRANGING SCREWS.] § 5. There is one essential point that must be carefully attended to, and that is, _that the horizontal propulsive thrust must be in the same plane as the vertical lift_, or the only effect will be to cause our model to turn somersaults. I speak from experience. When the horizontally revolving propellers are driven in a horizontal direction their "lifting" powers will be materially increased, as they will (like an ordinary aeroplane) be advancing on to fresh undisturbed air. § 6. I have not for ordinary purposes advocated very light weight wire framework fabric-covered screws, but in a case like this where the thrust from the propeller has to be more than the total weight of the machine, these might possibly be used with advantage. § 7. Instead of using two long vertical rods as well as one long horizontal one for the rubber strands, we might dispense with the two vertical ones altogether and use light gearing to turn the torque action through a right angle for the lifting screws, and use three separate horizontal rubber strands for the three propellers on a suitable light horizontal framework. Such should result in a considerable saving of weight. [Illustration: FIG. 52.--CORRECT MANNER. A, B, C = Screws.] § 8. The model would require something in the nature of a vertical fin or keel to give the sense of direction. Four propellers, two for "lift" and two for "drift," would undoubtedly be a better arrangement. FOOTNOTE: [47] Report on First Exhibition of Aeronautical Society of Great Britain, held at Crystal Palace, June 1868. CHAPTER XII. EXPERIMENTAL RECORDS. A model flying machine being a scientific invention and not a toy, every devotee to the science should make it his or her business to keep, as far as they are able, accurate and scientific records. For by such means as this, and the making known of the same, can a _science_ of model aeroplaning be finally evolved. The following experimental entry forms, left purposely blank to be filled in by the reader, are intended as suggestions only, and can, of course, be varied at the reader's discretion. When you _have_ obtained carefully established data, do not keep them to yourself, send them along to one of the aeronautical journals. Do not think them valueless; if carefully arranged they cannot be that, and may be very valuable. EXPERIMENTAL DATA. FORM I. Column Headings: A: Model B: Weight C: Area of Supporting Surface D: Aspect Ratio E: Average Length of Flight in Feet F: Maximum Flight G: Time of Flight, A. average H: M. maximum I: Kind and Direction of Wind J: Camber K: Angle of Inclination of Main Aerofoil to Line of Flight -----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- A | B | C | D | E | F | G | H | I | J | K -----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- | | | | | | A | M | | | 1 | | | | | | | | | | 2 | | | | | | | | | | 3 | | | | | | | | | | 4 | | | | | | | | | | 5 | | | | | | | | | | 6 | | | | | | | | | | 7 | | | | | | | | | | 8 | | | | | | | | | | 9 | | | | | | | | | | 10 | | | | | | | | | | 11 | | | | | | | | | | 12 | | | | | | | | | | | | | | | | | | | | -----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- FORM I.--_continued_. Column Headings: A: Model B: Weight of (Rubber) Motor C: Kind of Rubber, Flat, Square or Round D: Lenght in Inches and Number of Strands E: Number of Turns F: Condition at End of Flight G: Number of Propellers (No.) and Diameter (Diam.) H: Number of Blades I: Disc Area (DiscA.) and Pitch (Pitch) J: Percentage of Slip K: Thrust L: Torque in Inche-Ounces ----+----+----+-----+----+----+-----+----+-----+----+----+----+ A | B | C | D | E | F | G | H | I | J | K | L | ----+----+----+-----+----+----+-----+----+-----+----+----+----+ | | | | | | | | | | | | | | | 1 | | | | | | | | | | | | | | | 2 | | | | | | | | | | | | | | | 3 | | | | | | | | | | | | | | | 4 | | | | | | | | | | | | | | | 5 | | | | | | | | | | | | | | | 6 | | | | | | | | | | | | | | | 7 | | | | | | | | | | | | | | | 8 | | | | | | | | | | | | | | | 9 | | | | | | | | | | | | | | | 10 | | | | | | | | | | | | | | | 11 | | | | | | | | | | | | | | | 12 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ----+----+----+-----+----+----+-----+----+-----+----+----+----+ CHAPTER XIII. MODEL FLYING COMPETITIONS. § 1. From time to time flying competitions are arranged for model aeroplanes. Sometimes these competitions are entirely open, but more generally they are arranged by local clubs with both closed and open events. No two programmes are probably exactly alike, but the following may be taken as fairly representative:-- 1. Longest flight measured in a straight line (sometimes both with and against the wind).[48] 2. Stability (both longitudinal and transverse). 3. Longest glide when launched from a given height without power, but with motor and propeller attached. 4. Steering. 5. Greatest height. 6. The best all-round model, including, in addition to the above, excellence in building. Generally so many "points" or marks are given for each test, and the model whose aggregate of points makes the largest total wins the prize; or more than one prize may be offered-- One for the longest flight. One for the swiftest flight over a measured distance. One for the greatest height. One for stability and steering. And one for the best all-round model. The models are divided into classes:-- § 2. _Aero Models Association's Classification, etc._ A. Models of 1 sq. ft. surface and under. B. " 2 sq. ft. " " C. " 4 sq. ft. " " D. " 8 sq. ft. " " E. " over 8 sq. ft. All surfaces, whether vertical, horizontal, or otherwise, to be calculated together for the above classification. All round efficiency--marks or points as percentages:-- Distance 40 per cent. Stability 35 " Directional control 15 " Gliding angle 10 "[49] Two prizes:-- One for length of flight. One for all-round efficiency (marked as above). Every competitor to be allowed three trials in each competition, the best only to count. All flights to be measured in a straight line from the starting to the landing point. Repairs may be made during the competition at the direction of the judges.[50] There are one or two other points where flights are _not_ made with and against the wind. The competitors are usually requested to start their models from within a given circle of (say) six feet diameter, and fly them _in any direction_ they please. "Gliding angle" means that the model is allowed to fall from a height (say) of 20 ft. [Illustration: FIG. 53.--MODEL DESIGNED AND CONSTRUCTED BY THE AUTHOR FOR "GREATEST HEIGHT." A very lightly built model with a very low aspect ratio, and screw giving a very powerful dynamic thrust, and carrying rather a large amount of rubber. Climbs in left-handed spirals.] "Directional control," that the model is launched in some specified direction, and must pass as near as possible over some indicated point. The models are practically always launched by hand. § 3. Those who desire to win prizes at such competitions would do well to keep the following points well in mind. 1. The distance is always measured in a straight line. It is absolutely essential that your model should be capable of flying (approximately) straight. To see, as I have done, model after model fly quite 150 to 200 yards and finish within 50 yards of the starting-point (credited flight 50 yards) is useless, and a severe strain on one's temper and patience. [Illustration: FIG. 54.--THE GAMAGE CHALLENGE CUP. Open Competition for longest flight. Crystal Palace, July 27. Won by Mr. E.W. Twining.] [Illustration: FIG. 55.--MEDAL WON BY THE AUTHOR IN THE SAME COMPETITION.] 2. Always enter more than one model, there nearly always is an entrance fee; never mind the extra shilling or so. Go in to win. 3. It is not necessary that these models should be replicas of one another. On some days a light fabric-covered model might stand the best chance; on another day, a swift flying wooden or metal aerofoil. Against the wind the latter have an immense advantage; also if the day be a "gusty" one.[51] 4. Always make it a point of arriving early on the ground, so that you can make some trial flights beforehand. Every ground has its local peculiarities of air currents, etc. 5. Always be ready in time, or you may be disqualified. If you are flying a twin-screw model use a special winder, so that both propellers are wound up at the same time, and take a competent friend with you as assistant. 6. For all-round efficiency nothing but a good all-round model, which can be absolutely relied on to make a dozen (approximately) equivalent flights, is any good. 7. In an open distance competition, unless you have a model which you can rely on to make a _minimum_ flight of 200 yards, do not enter unless you know for certain that none of the "crack" flyers will be present. 8. Do not neglect the smallest detail likely to lead to success; be prepared with spare parts, extra rubber, one or two handy tools, wire, thread, etc. Before a lecture, that prince of experimentalists, Faraday, was always careful to see that the stoppers of all the bottles were loose, so that there should be no delay or mishap. 9. If the rating of the model be by "weight" (1 oz., 2 oz., 4 oz., etc.) and not area, use a model weighing from 10 oz. to a pound. 10. If there is a greatest height prize, a helicopter model should win it.[52] (The writer has attained an altitude of between three and four hundred feet with such.) The altitude was arrived at by observation, not guesswork. 11. It is most important that your model should be able to "land" without damage, and, as far as possible, on an even keel; do not omit some form of "skid" or "shock-absorber" with the idea of saving weight, more especially if your model be a biplane, or the number of flights may be restricted to the number "one." 12. Since the best "gliding" angle and "flying" angle are not the same, being, say, 7° in the former case and 1°-3°, say, in the latter, an adjustable angle might in some cases be advantageous. 13. Never turn up at a competition with a model only just finished and practically untested which you have flown only on the morning of the competition, using old rubber and winding to 500 turns; result, a flight of 250 yards, say. Arrived on the competition ground you put on new rubber and wind to 750 turns, and expect a flight of a quarter of a mile at least; result 70 yards, _measured in a straight line_ from the starting-point. 14. Directional control is the most difficult problem to overcome with any degree of success under all adverse conditions, and 15 per cent., in the writer's opinion, is far too low a percentage; by directional I include flying in a straight line; personally I would mark for all-round efficiency: (A) distance and stability, 50 per cent.; (B) directional control, 30 per cent.; (C) duration of flight, 20 per cent. In A the competitor would launch his model _in any direction_; in B as directed by the judges. No separate flights required for C. FOOTNOTES: [48] The better way, undoubtedly, is to allow the competitor to choose his direction, the starting "circle" only to be fixed. [49] Or 10 per cent. for duration of flight. [50] In another competition, held under the rules and regulations of the Kite and Model Aeroplane Association for the best all-round model, open to the world, for machines not under 2 sq. ft. of surface, the tests (50 marks for each) were:--A. Longest flight in a straight line. B. Circular flight to the right. C. Circular flight to the left. D. Stability and landing after a flight. E. Excellence in building of the model. [51] On the assumption that the model will fly straight. [52] If permitted to enter; if not see Fig. 53. CHAPTER XIV. USEFUL NOTES, TABLES, FORMULÆ, ETC. § 1. COMPARATIVE VELOCITIES. Miles per hr. Feet per sec. Metres per sec. 10 = 14·7 = 4·470 15 = 22 = 6·705 20 = 29·4 = 8·940 25 = 36·7 = 11·176 30 = 44 = 13·411 35 = 51·3 = 15·646 § 2. A metre = 39·37079 inches. _In order to convert_:-- Metres into inches multiply by 39·37 " feet " 3·28 " yards " 1·09 " miles " 0·0006214 Miles per hour into ft. per min. multiply by 88·0 " min. " sec. " 88·0 " hr. into kilometres per hr. " 1·6093 " " metres per sec. " 0·44702 Pounds into grammes multiply by 453·593 " kilogrammes " 0·4536 § 8. Total surface of a cylinder = circumference of base × height + 2 area of base. Area of a circle = square of diameter × 0·7854. Area of a circle = square of rad. × 3·14159. Area of an ellipse = product of axes × 0·7854. Circumference of a circle = diameter × 3·14159. Solidity of a cylinder = height × area of base. Area of a circular ring = sum of diameters × difference of diameters × 0·7854. For the area of a sector of a circle the rule is:--As 360 : number of degrees in the angle of the sector :: area of the sector : area of circle. To find the area of a segment less than a semicircle:--Find the area of the sector which has the same arc, and subtract the area of the triangle formed by the radii and the chord. The areas of corresponding figures are as the squares of corresponding lengths. § 4. 1 mile = 1·609 kilometres. 1 kilometre = 1093 yards. 1 oz. = 28·35 grammes. 1 lb. = 453·59 " 1 lb. = 0·453 kilogrammes. 28 lb. = 12·7 " 112 lb. = 50·8 " 2240 lb. = 1016 " 1 kilogram = 2·2046 lb. 1 gram = 0·0022 lb. 1 sq. in. = 645 sq. millimetres. 1 sq. ft. = 0·0929 sq. metres. 1 sq. yard = 0·836 " 1 sq. metre = 10·764 sq. ft. § 5. One atmosphere = 14·7 lb. per sq. in. = 2116 lb. per sq. ft. = 760 millimetres of mercury. A column of water 2·3 ft. high corresponds to a pressure of 1 lb. per sq. in. 1 H.P. = 33,000 ft.-lb. per min. = 746 watts. Volts × amperes = watts. {pi} = 3·1416. _g_ = 32·182 ft. per sec. at London. § 6. TABLE OF EQUIVALENT INCLINATIONS. Rise. Angle in Degs. 1 in 30 1·91 1 " 25 2·29 1 " 20 2·87 1 " 18 3·18 1 " 16 3·58 1 " 14 4·09 1 " 12 4·78 1 " 10 5·73 1 " 9 6·38 1 " 8 7·18 1 " 7 8·22 1 " 6 9·6 1 " 5 11·53 1 " 4 14·48 1 " 3 19·45 1 " 2 30·00 1 " {square root}2 45·00 § 7. TABLE OF SKIN FRICTION. Per sq. ft. for various speeds and surface lengths. -----------------+-------------+-------------+-------------+------------ Velocity of Wind | 1 ft. Plane | 2 ft. Plane | 4 ft. Plane | 8 ft. Plane -----------------+-------------+-------------+-------------+------------ 10 | ·00112 | ·00105 | ·00101 | ·000967 15 | ·00237 | ·00226 | ·00215 | ·00205 20 | ·00402 | ·00384 | ·00365 | ·00349 25 | ·00606 | ·00579 | ·00551 | ·00527 30 | ·00850 | ·00810 | ·00772 | ·00736 35 | ·01130 | ·0108 | ·0103 | ·0098 -----------------+-------------+-------------+-------------+------------ This table is based on Dr. Zahm's experiments and the equation _f_ = 0·00000778_l_^{-0·07}_v_^{1·85} Where _f_ = skin friction per sq. ft.; _l_ = length of surface; _v_ = velocity in feet per second. In a biplane model the head resistance is probably from twelve to fourteen times the skin friction; in a racing monoplane from six to eight times. § 8. TABLE I.--(METALS). --------------+------------+-----------------+------------- Material | Specific | Elasticity E[A] | Tenacity | Gravity | | per sq. in. --------------+------------+-----------------+------------- Magnesium | 1·74 | | {22,000- | | | {32,000 Magnalium[B] | 2·4-2·57 | 10·2 | Aluminium- } | | | Copper[C]} | 2·82 | | 54,773 Aluminium | 2·6 | 11·1 | 26,535 Iron | 7·7 (about)| 29 | 54,000 Steel | 7·8 (about)| 32 | 100,000 Brass | 7·8-8·4 | 15 | 17,500 Copper | 8·8 | 36 | 33,000 Mild Steel | 7·8 | 30 | 60,000 | | | --------------+------------+-----------------+------------- [A] E in millions of lb. per sq. in. [B] Magnalium is an alloy of magnesium and aluminium. [C] Aluminium 94 per cent., copper 6 per cent. (the best percentage), a 6 per cent. alloy thereby doubles the tenacity of pure aluminium with but 5 per cent. increase of density. --------------+------------+-----------------+------------- § 9. TABLE II.--WIND PRESSURES. _p_ = _kv²_. _k_ coefficient (mean value taken) ·003 (miles per hour) = 0·0016 ft. per second. _p_ = pressure in lb. per sq. ft. _v_ = velocity of wind. Miles per hr. Ft. per sec. Lb. per sq. ft. 10 14·7 0·300 12 17·6 0·432 14 20·5 0·588 16 23·5 0·768 18 26·4 0·972 20 29·35 1·200 25 36·7 1·875 30 43·9 2·700 35 51·3 3·675 § 10. Representing normal pressure on a plane surface by 1; pressure on a rod (round section) is 0·6; on a symmetrical elliptic cross section (axes 2:1) is 0·2 (approx.). Similar shape, but axes 6:1, and edges sharpened (_see_ ch. ii., § 5), is only 0·05, or 1/20, and for the body of minimum resistance (_see_ ch. ii., § 4) about 1/24. § 11. TABLE III.--LIFT AND DRIFT. On a well shaped aerocurve or correctly designed cambered surface. Aspect ratio 4·5. Inclination. Ratio Lift to Drift. 0° 19:1 2·87° 15:1 3·58° 16:1 4·09° 14:1 4·78° 12:1 5·73° 9·6:1 7·18° 7·9:1 Wind velocity 40 miles per hour. (The above deduced from some experiments of Sir Hiram Maxim.) At a velocity of 30 miles an hour a good aerocurve should lift 21 oz. to 24 oz. per sq. ft. § 12. TABLE IV.--LIFT AND DRIFT. On a plane aerofoil. N = P(2 sin {alpha}/1 + sin² {alpha}) Inclination. Ratio Lift to Drift. 1° 58·3:1 2° 29·2:1 3° 19·3:1 4° 14·3:1 5° 11·4:1 6° 9·5:1 7° 8·0:1 8° 7·0:1 9° 6·3:1 10° 5·7:1 P = 2_kd_ AV² sin {alpha}. A useful formula for a single plane surface. P = pressure supporting the plane in pounds per square foot, _k_ a constant = 0·003 in miles per hour, _d_ = the density of the air. A = the area of the plane, V relative velocity of translation through the air, and {alpha} the angle of flight. Transposing we have AV² = P/(2_kd_ sin {alpha}) If P and {alpha} are constants; then AV² = a constant or area is inversely as velocity squared. Increase of velocity meaning diminished supporting surface (_and so far as supporting surface goes_), diminished resistance and skin friction. It must be remembered, however, that while the work of sustentation diminishes with the speed, the work of penetration varies as the cube of the speed. § 13. TABLE V.--TIMBER. Column Headings: A. Material B. Specific Gravity C. Weight per Cub. Ft. in Lb. D. Strength per Sq. In. in Lb. E. Ultimate Breaking Load (Lb.) span 1' x 1" x 1" F. Relative Resilience in Bending G. Modulus of Elasticity in millions of Lb. per Sq. In. for Bending H. Relative Value. Bending Strength compared with Weight ---------------+-----+-------+-------------+-------+-----+-----+---- A |B | C | D |E |F |G | H ---------------+-----+-------+-------------+-------+-----+-----+---- Ash | ·79 | 43-52 |14,000-17,000| 622 |4·69 |1·55 |13·0 Bamboo | | 25[A]| 6300[53] | |3·07 |3·20 | Beech | ·69 | 43 |10,000-12,000| 850 | |1·65 |19·8 Birch | ·71 | 45 | 15,000 | 550 | |3·28 |12·2 Box |1·28 | 80 |20,000-23,000| 815 | | |10·2 Cork | ·24 | 15 | | | | | Fir (Norway | | | | | | | Spruce) | ·51 | 32 | 9,000-11,000| 450 |3·01 |1·70 |14·0 American | | | | | | | Hickory | | 49 | 11,000 | 800 |3·47 |2·40 |16·3 Honduras | | | | | | | Mahogany | ·56 | 35 | 20,000 | 750 |3·40 |1·60 |21·4 Maple | ·68 | 44 | 10,600 | 750 | | |17·0 American White | | | | | | | Pine | ·42 | 25 | 11,800 | 450 |2·37 |1·39 |18·0 Lombardy Poplar| | 24 | 7,000 | 550 |2·89 | 0·77|22·9 American Yellow| | | | | | | Poplar | | 44 | 10,000 | |3·63 |1·40 | Satinwood | ·96 | 60 | |1,033 | | |17·2 Spruce | ·50 | 31 | 12,400 | 450 | | |14·5 Tubular Ash, | | | | | | | _t_ = 1/8 _d_ | | 47 | | |3·50 |1·55 | ---------------+-----+-------+-------------+-------+-----+-----+---- _t_ = thickness: _d_ = diameter. [A] Given elsewhere as 55 and 22,500 (_t_ = 1/3_d_), evidently regarded as solid. § 14.--=Formula connecting the Weight Lifted in Pounds per Square Foot and the Velocity.=--The empirical formula W = (V²C)/_g_ Where W = weight lifted in lb. per sq. ft. V = velocity in ft. per sec. C = a constant = 0·025. _g_ = 32·2, or 32 approx. may be used for a thoroughly efficient model. This gives (approximately) 1 lb. per sq. ft. lift at 25 miles an hour. 21 oz. " " 30 " 6 oz. " " 15 " 4 oz. " " 12 " 2·7 oz. " " 10 " Remember the results work out in feet per second. To convert (approximately) into miles per hour multiply by 2/3. § 15. =Formula connecting Models of Similar Design, but Different Weights.= D {proportional to} {square root}W. or in models of _similar design_ the distances flown are proportional to the square roots of the weights. (Derived from data obtained from Clarke's flyers.) For models from 1 oz. to 24-30 oz. the formula appears to hold very well. For heavier models it appears to give the heavier model rather too great a distance. Since this was deduced a 1 oz. Clarke model of somewhat similar design but longer rubber motor has flown 750 ft. at least; it is true the design is not, strictly speaking, similar, but not too much reliance must be placed on the above. The record for a 1 oz. model to date is over 300 yards (with the wind, of course), say 750 ft. in calm air. § 16. =Power and Speed.=--The following formula, given by Mr. L. Blin Desbleds, between these is-- W/W{0} = (3_v{0}_)/(4_v_) + ¼(_v_/_v{0}_)³. Where _v{0}_ = speed of minimum power W{0} = work done at speed _v{0}_. W = work done at speed _v_. Making _v_ = 2_v{0}_, i.e. doubling the speed of minimum power, and substituting, we have finally W = (2-3/8)W{0} i.e. the speed of an aeroplane can be doubled by using a power 2-3/8 times as great as the original one. The "speed of minimum power" being the speed at which the aeroplane must travel for the minimum expenditure of power. § 17. The thrust of the propeller has evidently to balance the Aerodynamic resistance = R The head resistance (including skin friction) = S Now according to Renard's theorem, the power absorbed by R + S is a minimum when S = R/3. Having built a model, then, in which the total resistance = (4/3)R. This is the thrust which the propeller should be designed to give. Now supposing the propeller's efficiency to be 80 per cent., then P--the minimum propulsion power = (4/3)R × 100/80 × 100/75 × _v_. Where 25 per cent. is the slip of the screw, _v_ the velocity of the aeroplane. § 18. =To determine experimentally the Static Thrust of a Propeller.=--Useful for models intended to raise themselves from the ground under their own power, and for helicopters. The easiest way to do this is as follows: Mount the propeller on the shaft of an electric motor, of sufficient power to give the propeller 1000 to 1500 revolutions per minute; a suitable accumulator or other source of electric energy will be required, a speedometer or speed counter, also a voltmeter and ammeter. Place the motor in a pair of scales or on a suitable spring balance (the former is preferable), the axis of the motor vertical, with the propeller attached. Rotate the propeller so that the air current is driven _upwards_. When the correct speed (as indicated by the speed counter) has been attained, notice the difference in the readings if a spring balance be used, or, if a pair of scales, place weights in the scale pan until the downward thrust of the propeller is exactly balanced. This gives you the thrust in ounces or pounds. Note carefully the voltage and amperage, supposing it is 8 volts and 10 amperes = 80 watts. Remove the propeller and note the volts and amperes consumed to run the motor alone, i.e. to excite itself, and overcome friction and air resistance; suppose this to be 8 volts and 2 amperes = 16; the increased load when the propeller is on is therefore 80 - 16 = 64 watts. All this increased power is not, however, expended on the propeller. The lost power in the motor increases as C²R. R = resistance of armature and C = current. If we deduct 10 per cent. for this then the propeller is actually driven by 56 watts. Now 746 watts = 1 h.p. {therefore} 56/746 = 1/13 h.p. approx. at the observed number of revolutions per minute. § 19. N.B.--The h.p. required to drive a propeller varies as the cube of the revolutions. _Proof._--Double the speed of the screw, then it strikes the air twice as hard; it also strikes twice as much air, and the motor has to go twice as fast to do it. § 20. To compare one model with another the formula Weight × velocity (in ft. per sec.)/horse-power is sometimes useful. § 21. =A Horse-power= is 33,000 lb. raised one foot in one minute, or 550 lb. one foot in one second. A clockwork spring raised 1 lb. through 4½ ft. in 3 seconds. What is its h.p.? 1 lb. through 4½ ft. in 3 seconds is 1 lb. " 90 ft. " 1 minute. {therefore} Work done is 90 ft.-lb. = 90/33000 = 0·002727 h.p. The weight of the spring was 6¾ oz. (this is taken from an actual experiment), i.e. this motor develops power at the rate of 0·002727 h.p. for 3½ seconds only. § 22. =To Ascertain the H.P. of a Rubber Motor.= Supposing a propeller wound up to 250 turns to run down in 15 seconds, i.e. at a mean speed of 1200 revolutions per minute or 20 per second. Suppose the mean thrust to be 2 oz., and let the pitch of the propeller be 1 foot. Then the number of foot-pounds of energy developed = (2 oz. × 1200 revols. × 1 ft. (pitch)) / 16 oz. = 150 ft.-lb. per minute. But the rubber motor runs down in 15 seconds. {therefore} Energy really developed is = (150 × 15) / 60 = 37·5 ft.-lb. The motor develops power at rate of 150/33000 = 0·004545 h.p., but for 15 seconds only. § 23. =Foot-pounds of Energy in a Given Weight of Rubber= (experimental determination of). Length of rubber 36 yds. Weight " 2-7/16 oz. Number of turns = 200. 12 oz. were raised 19 ft. in 5 seconds. i.e. ¾ lb. was raised 19 × 12 ft. in 1 minute. i.e. 1 lb. was raised 19 × 3 × 3 ft. in 1 minute. = 171 ft. in 1 minute. i.e. 171 ft.-lb. of energy per minute. But actual time was 5 seconds. {therefore} Actual energy developed by 2-7/16 oz. of rubber of 36 yards, i.e. 36 strands 1 yard each at 200 turns is = 171/12 ft.-lb. = 14¼ ft.-lb. This allows nothing for friction or turning the axle on which the cord was wound. Ball bearings were used; but the rubber was not new and twenty turns were still unwound at the end of the experiment. Now allowing for friction, etc. being the same as on an actual model, we can take ¾ of a ft.-lb. for the unwound amount and estimate the total energy as 15 ft.-lb. as a minimum. The energy actually developed being at the rate of 0·0055 h.p., or 1/200 of a h.p. if supposed uniform. § 24. The actual energy derivable from 1 lb. weight of rubber is stated to be 300 ft.-lb. On this basis 2-7/16 oz. should be capable of giving 45·7 ft.-lb. of energy, i.e. three times the amount given above. Now the motor-rubber not lubricated was only given 200 turns--lubricated 400 could have been given it, 600 probably before rupture--and the energy then derivable would certainly have been approximating to 45 ft.-lb., i.e. 36·25. Now on the basis of 300 ft.-lb. per lb. a weight of ½ oz. (the amount of rubber carried in "one-ouncers") gives 9 ft.-lb. of energy. Now assuming the gliding angle (including weight of propellers) to be 1 in 8; a perfectly efficient model should be capable of flying eight times as great a distance in a horizontal direction as the energy in the rubber motor would lift it vertically. Now 9 ft.-lb. of energy will lift 1 oz. 154 ft. Therefore theoretically it will drive it a distance (in yards) of (8 × 154)/3 = 410·6 yards. Now the greatest distance that a 1 oz. model has flown in perfectly calm air (which never exists) is not known. Flying with the wind 500 yards is claimed. Admitting this what allowance shall we make for the wind; supposing we deduct half this, viz. 250 yards. Then, on this assumption, the efficiency of this "one ouncer" works out (in perfectly still air) at 61 per cent. The gliding angle assumption of 1 in 8 is rather a high one, possibly too high; all the writer desires to show is the method of working out. Mr. T.W.K. Clarke informs me that in his one-ouncers the gliding angle is about 1 in 5. § 25. =To Test Different Motors or Different Powers of the Same Kind of Motor.=--Test them on the same machine, and do not use different motors or different powers on different machines. § 26. =Efficiency of a Model.=--The efficiency of a model depends on the weight carried per h.p. § 27. =Efficiency of Design.=--The efficiency of some particular design depends on the amount of supporting surface necessary at a given speed. § 28. =Naphtha Engines=, that is, engines made on the principle of the steam engine, but which use a light spirit of petrol or similar agent in their generator instead of water with the same amount of heat, will develop twice as much energy as in the case of the ordinary steam engine. § 29.=Petrol Motors.= Horse-power. No. of Cylinders. Weight. ¼ Single 4½ lb. ½ to ¾ " 6½ " 1½ Double 9 " § 30. =The Horse-power of Model Petrol Motors.=--Formula for rating of the above. (R.P.M. = revolutions per minute.) H.P. = ((Bore)² × stroke × no. of cylinders × R.P.M.)/12,000 If the right-hand side of the equation gives a less h.p. than that stated for some particular motor, then it follows that the h.p. of the motor has been over-estimated. [Illustration: FIG. 56.] § 30A. =Relation between Static Thrust of Propeller and Total Weight of Model.=--The thrust should be approx. = ¼ of the weight. § 31. =How to find the Height of an Inaccessible Object by Means of Three Observations taken on the Ground (supposed flat) in the same Straight Line.=--Let A, C, B be the angular elevations of the object D, as seen from these points, taken in the same straight line. Let the distances B C, C A and A B be _a_, _b_, _c_ respectively. And let required height P D = _h_; then by trigonometry we have (see Fig. 56) _h²_ = _abc_/(_a_ cot²A - _c_ cot²C + _b_ cot²B). § 32. =Formula= for calculating the I.H.P. (indicated horse-power) of a single-cylinder double-acting steam-engine. Indicated h.p. means the h.p. actually exerted by the steam in the cylinder without taking into account engine friction. Brake h.p. or effective h.p. is the actual h.p. delivered by the crank shaft of the engine. I.H.P. = (2 × S × R × A × P)/33,000. Where S = stroke in feet. R = revolutions per minute. A = area of piston in inches. P = mean pressure in lb. exerted per sq. in. on the piston. The only difficulty is the mean effective pressure; this can be found approximately by the following rule and accompanying table. TABLE VI. ---------+----------+---------+----------+---------+--------- Cut-off | Constant | Cut-off | Constant | Cut-off | Constant ---------+----------+---------+----------+---------+--------- 1/6 | ·566 | 3/8 | ·771 | 2/3 | ·917 1/5 | ·603 | ·4 | ·789 | ·7 | ·926 1/4 | ·659 | 1/2 | ·847 | 3/4 | ·937 ·3 | ·708 | ·6 | ·895 | ·8 | ·944 1/3 | ·743 | 5/8 | ·904 | 7/8 | ·951 ---------+----------+---------+----------+---------+--------- Rule.--"Add 14·7 to gauge pressure of boiler, this giving 'absolute steam pressure,' multiply this sum by the number opposite the fraction representing the point of cut-off in the cylinder in accompanying table. Subtract 17 from the product and multiply the remainder by 0·9. The result will be very nearly the M.E.P." (R.M. de Vignier.) FOOTNOTE: [53] Given elsewhere as 55 and 22,500 (_t_ = 1/3 _d_), evidently regarded as solid. APPENDIX A. SOME MODELS WHICH HAVE WON MEDALS AT OPEN COMPETITIONS. [Illustration: FIG. 57.--THE G.P.B. SMITH MODEL.] The model shown in Fig. 57 has won more competition medals than any other. It is a thoroughly well designed[54] and well constructed model. Originally a very slow flyer, the design has been simplified, and although by no means a fast flyer, its speed has been much accelerated. Originally a one-propeller machine, it has latterly been fitted with twin propellers, with the idea of obtaining more directional control; but in the writer's opinion, speaking from personal observation, with but little, if any, success. The steering of the model is effected by canting the elevator. Originally the machine had ailerons for the purpose, but these were removed owing, I understand, to their retarding the speed of the machine. In every competition in which this machine has been entered it has always gained very high marks for stability. [Illustration: FIG. 58.--THE GORDON-JONES DIHEDRAL BIPLANE.] Up to the time of writing it has not been provided with anything in the nature of fins or rudder. Fig. 58 is a biplane very much after the type of the model just alluded to, but the one straight and one curved aerofoil surfaces are here replaced by two parallel aerofoils set on a dihedral angle. The large size of the propeller should be noted; with this the writer is in complete agreement. He has not unfortunately seen this model in actual flight. The scientifically designed and beautifully made models illustrated in Fig. 59 are so well known that any remarks on them appear superfluous. Their efficiency, so far as their supporting area goes, is of the highest, as much as 21 oz. per square foot having been carried. [Illustration: FIG. 59.--MESSRS. T.W.K. CLARKE AND CO.'S MODEL FLYERS.] For illustrations, etc., of the Fleming-Williams model, _see_ ch. v., § 23. (Fig. 60.) This is another well-constructed and efficient model, the shape and character of the aerofoil surfaces much resembling those of the French toy monoplane AL-MA (see § 4, ch. vii.), but they are supported and held in position by quite a different method, a neat little device enabling the front plane to become partly detached on collision with any obstacle. The model is provided with a keel (below the centre of gravity), and rudder for steering; in fact, this machine especially claims certainty of directional control. The writer has seen a number of flights by this model, but it experiences, like other models, the greatest difficulty in keeping straight if the conditions be adverse. The model which will do this is, in his opinion, yet to be evolved. The small size of the propellers is, of course, in total disagreement with the author's ideas. All the same, the model is in many respects an excellent one, and has flown over 300 yards at the time of writing. [Illustration: FIG. 60.--THE DING SAYERS MONOPLANE.] More than a year ago the author made a number of models with triangular-shaped aerofoils, using umbrella ribs for the leading edge and steel piano wire for the trailing, but has latterly used aerofoils of the elongated ellipse shape. Fig. 61 is an illustration of one of the author's latest models which won a Bronze Medal at the Long Distance Open Competition, held at the Crystal Palace on July 27, 1910, the largest and most keenly contested competition held up to that date. The best and straightest flight against the wind was made by this model. On the morning of the competition a flight of about 320 yards (measured in a straight line) was made on Mitcham Common, the model being launched against the wind so as to gain altitude, and then flying away with the breeze behind the writer. Duration of flight 50 seconds. The following are the chief particulars of the model:--Weight, 7½ oz. Area of supporting surface, 1-1/3 sq. ft. Total length, 4 ft. Span of main aerofoil, 25 in. Aspect ratio, 4 : 1. Diameter of propeller, 14 in. Two strand geared rubber motor, carrying altogether 28 strands of 1/16 square rubber cord 43 in. long. The propeller was originally a Venna, but with the weight reduced by one-third, and considerable alteration made in its central contours. The front skid of steel pianoforte wire, the rear of jointless cane wire tipped; the rear skid was a necessity in order to protect the delicate gearing mechanism, the weight of which was reduced to a minimum. [Illustration: FIG. 61.--THE AUTHOR'S "GRASSHOPPER" MODEL.] The very large diameter of the propeller should be noted, being 56 per cent. of the span. The fin, high above the centre of gravity, was so placed for transverse stability and direction. At the rear of the fin was a rudder. The small amount of rubber carried (for a long distance machine) should also be noted, especially when allowing for friction in gearing, etc. The central rod was a penny bamboo cane, the large aerofoil of jointless cane and Hart's fabric, and the front aerofoil of steel wire surfaced with the same material. LONDON: PRINTED BY WILLIAM CLOWES AND SONS, LIMITED, GREAT WINDMILL STREET, W., AND DUKE STREET, STAMFORD STREET, S.E. FOOTNOTE: [54] The design is patented. _October, 1910_ A SHORT LIST OF SCIENTIFIC BOOKS PUBLISHED AND SOLD BY E. & F.N. SPON, Limited, 57 Haymarket, London, S.W. SOLE ENGLISH AGENTS for the Books of-- MYRON C. CLARK, NEW YORK THE BUSINESS CODE COMPANY, CHICAGO SPON & CHAMBERLAIN, NEW YORK PAGE AERONAUTICS 2 AGRICULTURE 2 ARCHITECTURE 3 ARTILLERY 5 BRIDGES AND ROOFS 5 BUILDING 3 CEMENT AND CONCRETE 7 CIVIL ENGINEERING 8 DICTIONARIES 11 DOMESTIC ECONOMY 12 DRAWING 13 ELECTRICAL ENGINEERING 14 FOREIGN EXCHANGE 19 GAS AND OIL ENGINES 20 GAS LIGHTING 20 HISTORICAL; BIOGRAPHICAL 21 HOROLOGY 22 HYDRAULICS 22 INDUSTRIAL CHEMISTRY 24 IRRIGATION 27 LOGARITHM TABLES 28 MANUFACTURES 24 MARINE ENGINEERING 28 MATERIALS 30 MATHEMATICS 31 MECHANICAL ENGINEERING 33 METALLURGY 36 METRIC TABLES 38 MINERALOGY AND MINING 38 MUNICIPAL ENGINEERING 45 NAVAL ARCHITECTURE 28 ORGANISATION 40 PHYSICS 41 PRICE BOOKS 42 RAILWAY ENGINEERING 43 SANITATION 45 STRUCTURAL DESIGN 45 TELEGRAPH CODES 47 WARMING; VENTILATION 47 WATER SUPPLY 48 WORKSHOP PRACTICE 49 USEFUL TABLES 52 MISCELLANEOUS 53 _Full particulars post free on application. 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(_1896_) 9 0 =Scamping Tricks and Odd Knowledge= occasionally practised upon Public Works. By J. NEWMAN. New impression, 129 pp. crown 8vo. (_1908_) _net_ 2 0 =Earthwork Slips and Subsidences= on Public Works. By J. NEWMAN. 240 pp. crown 8vo. (_1890_) 7 6 =Co-ordinate Geometry= as applied to Land Surveying. By W. PILKINGTON. 5 illus. 44 pp. 12mo. (_1909_) _net_ 1 6 =Diagrams for the Graphic Calculation of Earthwork Quantities.= By A.H. ROBERTS. Ten cards, fcap. in cloth case _net_ 10 6 =Pioneering.= By F. SHELFORD, illustrated. 88 pp. crown 8vo. (_1909_) _net_ 3 0 =Topographical Surveying.= By G.J. SPECHT. Second edition, 2 plates and 28 illus. 210 pp. 18mo, boards. (_New York, 1898_) _net_ 2 0 =Spons' Dictionary of Engineering,= Civil, Mechanical, Military and Naval. 10,000 illus. 4300 pp. super royal 8vo. (_1874, Supplement issued in 1881_). Complete with Supplement, in 11 divisions _net_ 3 10 0 Ditto ditto in 4 vols. _net_ 3 3 0 =Surveying and Levelling Instruments.= By W.F. STANLEY. Third edition, 372 illus. 562 pp. crown 8vo. (_1901_) 7 6 =Surveyor's Handbook.= By T.U. TAYLOR. 116 illus. 310 pp. crown 8vo, leather, gilt edges. (_New York, 1908_) _net_ 8 6 =Logarithmic Land Measurement.= By J. WALLACE. 32 pp. royal 8vo. (_1910_) _net_ 5 0 =Hints on Levelling Operations.= By W.H. WELLS. Second edition, 8vo, sewed. (_1890_) _net_ 1 0 =The Drainage of Fens and Low Lands= by Gravitation and Steam Power. By W.H. WHEELER. 8 plates, 175 pp. 8vo. (_1888_) 12 6 =Stadia Surveying,= the theory of Stadia Measurements. By A. WINSLOW. Fifth edition, 148 pp. 18mo, boards. (_New York, 1902_) _net_ 2 0 =Handbook on Tacheometrical Surveying.= By C. XYDIS. 55 illus. 3 plates, 63 pp. 8vo. (_1909_) _net_ 6 0 DICTIONARIES. =Technological Dictionary in the English, Spanish, German and French Languages.= By D. CARLOS HUELIN Y ARSSU. Crown 8vo. Vol. I. ENGLISH-SPANISH-GERMAN-FRENCH. 609 pp. (_1906_) _net_ 10 6 Vol. II. GERMAN-ENGLISH-FRENCH-SPANISH. 720 pp. (_1908_) _net_ 10 6 Vol. III. FRENCH-GERMAN-SPANISH-ENGLISH. In preparation. Vol. IV. SPANISH-FRENCH-ENGLISH-GERMAN. 750 pp. (_1910_) _net_ 10 6 =English-French and French-English Dictionary of the Motor-Car, Cycle and Boat.= By F. LUCAS. 171 pp. crown 8vo. (_1905_) _net_ 5 0 =Spanish-English Dictionary of Mining Terms.= By F. LUCAS. 78 pp. 8vo. (_1905_) _net_ 5 0 =English-Russian and Russian-English Engineering Dictionary.= By L. MEYCLIAR. 100 pp. 16mo. (_1909_) _net_ 2 6 =Reed's Polyglot Guide to the Marine Engine,= in English, French, German and Norsk. Second edition, oblong 8vo. (_1900_). _net_ 6 0 DOMESTIC ECONOMY. =Food Adulteration and its Detection.= By J.P. BATTERSHALL. 12 plates, 328 pp. demy 8vo. (_New York, 1887_) 15 0 =How to Check Electricity Bills.= By S.W. BORDEN. 41 illus. 54 pp. crown 8vo. (_New York, 1907_) _net_ 2 0 =Practical Hints on Taking a House.= By H.P. BOULNOIS. 71 pp. 18mo. (_1885_) 1 6 =The Cooking Range,= its Failings and Remedies. By F. DYE. 52 pp. fcap. 8vo, sewed. (_1888_) 0 6 =The Kitchen Boiler and Water Pipes.= By H. GRIMSHAW. 8vo, sewed. (_1887_) _net_ 1 0 =Cookery and Domestic Management,= including economic and middle class Practical Cookery. By K. MELLISH. 56 coloured plates and 441 illus. 987 pp. super-royal 8vo. (_1901_) _net_ 16 0 =Spons' Household Manual.= 250 illus. 1043 pp. demy 8vo. (_1902_) 7 6 Ditto ditto half-bound French morocco 9 0 =Handbook of Sanitary Information= for Householders. By R.S. TRACY. 33 illus. 114 pp. 18mo. (_New York, 1900_) 2 6 DRAWING. =The Ornamental Penman's,= Engraver's and Sign Writer's Pocket Book of Alphabets. By B. ALEXANDER. Oblong 12mo, sewed 0 6 =The Draughtsman's Handbook= of Plan and Map Drawing. By G.G. ANDRE. 87 illus. and 34 plain and coloured plates, 162 pp. crown 4to. (_1891_) 9 0 =Slide Valve Diagrams:= a French Method for their Construction. By L. BANKSON. 18mo, boards. (_New York, 1892_) . . . _net_ 2 0 =A System of Easy Lettering.= By J.H. CROMWELL. With Supplement by G. MARTIN. Sixth thousand, oblong 8vo. (_New York, 1900_) _net_ 2 0 =Plane Geometrical Drawing.= BY R.C. FAWDRY. Illustrated, 185 pp. crown 8vo. (_1901_) _net_ 3 0 =Twelve Plates on Projection Drawing.= By O. GUETH. Oblong 4to. (_New York, 1903_) _net_ 3 0 =Hints on Architectural Draughtsmanship.= By G.W.T. HALLATT. Fourth edition, 80 pp. 18mo. (_1906_) _net_ 1 6 =A First Course of Mechanical Drawing= (Tracing). By G. HALLIDAY. Oblong 4to, sewed 2 0 =Drawings for Medium-sized Repetition Work.= By R.D. SPINNEY. With 47 illus. 130 pp. 8vo. (_1909_) _net_ 3 6 =Mathematical Drawing Instruments.= By W.F. STANLEY. Seventh edition, 265 illus. 370 pp. crown 8vo. (_1900_) 5 0 ELECTRICAL ENGINEERING. =Practical Electric Bell Fitting.= By F.C. ALLSOP. Tenth edition, 186 illus. including 8 folding plates, 185 pp. crown 8vo. (_1903_) 3 6 =Telephones:= their Construction and Fitting. By F.C. ALLSOP. Eighth edition, 184 illus. 222 pp. crown 8vo. (_1909_) 3 6 =Thermo-electric Reactions= and Currents between Metals in Fused Salts. By T. ANDREWS. 8vo, sewed. (_1896_) 1 0 =Auto-Transformer Design.= By A.H. AVERY. 25 illus. 60 pp. 8vo. (_1909_) _net_ 3 6 =Principles of Electric Power= (Continuous Current) for Mechanical Engineers. By A.H. BATE. 63 illus. 204 pp. crown 8vo. (_1905_) (FINSBURY TECHNICAL MANUAL) _net_ 4 6 =Practical Construction of Electric Tramways.= By WILLIAM R. BOWKER. 93 illus. 119 pp. 8vo. (_1903_) _net_ 6 0 =Design and Construction of Induction Coils.= By A.F. COLLINS. 155 illus. 272 pp. demy 8vo. (_New York, 1909_) _net_ 12 6 =Switchboard Measuring Instruments= for Continuous and Polyphase Currents. By J.C. CONNAN. 117 illus. 150 pp. 8vo, cloth. (_1908_) _net_ 5 0 =Electric Cables, their Construction and Cost.= By D. COYLE and F.J. O. HOWE. With many diagrams and 216 tables, 467 pp. crown 8vo, leather. (_1909_) _net_ 15 0 =Management of Electrical Machinery.= By F.B. CROCKER and S.S. WHEELER. Eighth edition, 131 illus. 223 pp. crown 8vo. (_New York, 1909_) _net_ 4 6 =Electric Lighting:= A Practical Exposition of the Art. By F.B. CROCKER. Royal 8vo. (_New York._) Vol. I. =The Generating Plant.= Sixth edition, 213 illus. 470 pp. (_1904_) _net_ 12 6 Vol. II. =Distributing Systems and Lamps.= Second edition, 391 illus. 505 pp. (_1905_) _net_ 12 6 =The Care and Management of Ignition Accumulators.= By H.H.U. CROSS. 12 illus. 74 pp. crown 8vo, limp. (S. & C. SERIES, NO. 19.) (_1910_) _net_ 1 6 =Elementary Telegraphy and Telephony.= By ARTHUR CROTCH. 238 illus. 223 pp. 8vo. (_1903._) (FINSBURY TECHNICAL MANUAL) _net_ 4 6 =Electricity and Magnetism in Telephone Maintenance.= By G.W. CUMMINGS. 45 illus. 137 pp. 8vo. (_New York, 1908_) . .. _net_ 6 6 =Grouping of Electric Cells.= By W.F. DUNTON. 4 illus. 50 pp. fcap. 8vo. (1906) _net_ 1 6 MAGNETS AND ELECTRIC CURRENTS. By Prof. J.A. FLEMING. Second edition, 136 illus. 417 pp. crown 8vo (_1902_) _net_ 5 0 =Notes on Design of Small Dynamo.= By GEORGE HALLIDAY. Second edition, 8 plates, 8vo. (_1895_) 2 6 =Practical Alternating Currents and Power Transmission.= By N. HARRISON. 172 illus. 375 pp. crown 8vo. (_New York, 1906_) 10 6 =Making Wireless Outfits.= By N. HARRISON. 27 illus. 61 pp. crown 8vo, limp. (S. & C. SERIES, NO. 11.) (_New York, 1909_) _net_ 1 6 =Wireless Telephone Construction.= By N. HARRISON. 43 illus. 73 pp. crown 8vo, limp. (S. & C. Series, No. 12.) (_New York, 1909_) _net_ 1 6 =The Phoenix Fire Office Rules= for Electric Light and Electrical Power Installations. By M. HEAPHY. Thirty-seventh edition, 8vo, sewed. (_1908_) 0 6 =Testing Telegraph Cables.= By Colonel V. HOSKIOER. Third edition, crown 8vo. (_1889_) 4 6 =Long Distance Electric Power Transmission.= By R.W. HUTCHINSON. 136 illus. 345 pp. crown 8vo. (_New York, 1907_) _net_ 12 6 =Theory and Practice of Electric Wiring.= By W.S. IBBETSON. 119 illus. 366 pp. crown 8vo. (_1909_) _net_ 5 0 =Practical Electrical Engineering for Elementary Students.= By W.S. IBBETSON. With 61 illus. 155 pp. crown 8vo. (_1910_) _net_ 3 0 =General Rules recommended for Wiring= for the Supply of Electrical Energy. Issued by THE INSTITUTION OF ELECTRICAL ENGINEERS. 8vo, sewed. (_Revised, April 1907_) _net_ 0 6 =Form of Model General Conditions= recommended by THE INSTITUTION OF ELECTRICAL ENGINEERS for use in connection with Electrical Contracts. 8vo, sewed. (_1906_) _net_ 1 0 =A Handbook of Electrical Testing.= By H.R. KEMPE. Seventh edition, 285 illus. 706 pp. demy 8vo. (_1908_) _net_ 18 0 =Application of Electricity to Railway Working.= By W.E. LANGDON. 142 illus. and 5 plates, 347 pp. 8vo. (_1897_) 10 6 =How to Become a Competent Motorman.= By V.B. LIVERMORE and J. WILLIAMS. 45 illus. 252 pp. 12mo. (_New York, 1903_) _net_ 4 6 =Electromagnets,= their design and construction. By A.N. MANSFIELD. 36 illus. 155 pp. 18mo, boards. (_New York, 1901_) _net_ 2 0 =Telephone Construction, Methods and Cost.= By C. MAYER. With Appendices on the cost of materials and labour by J.C. SLIPPY. 103 illus. 284 pp. crown 8vo. (_New York, 1908_) _net_ 12 6 =Induction Coils.= By N.H. SCHNEIDER. Second edition, 79 illus. 285 pp. crown 8vo. (_New York, 1901_) _net_ 4 6 =Electric Gas Lighting.= By N.H. SCHNEIDER. 57 illus. 101 pp. 12mo. (S. & C. SERIES, NO. 8.) (_New York, 1901_) _net_ 2 0 =How to Install Electric Bells, Annunciators and Alarms.= By N.H. SCHNEIDER. 59 illus. 63 pp. crown 8vo, limp. (S. & C. SERIES, NO. 2.) (_New York, 1905_) _net_ 1 6 =Modern Primary Batteries,= their construction, use and maintenance. By N.H. SCHNEIDER. 54 illus. 94 pp. crown 8vo, limp. (S. & C. SERIES, NO. 1.) (_New York, 1905_) _net_ 1 6 =Practical Engineers' Handbook on the Care and Management of Electric Power Plants.= By N.H. SCHNEIDER. 203 illus. 274 pp. crown 8vo. (_New York, 1906_) _net_ 5 0 =Electrical Circuits and Diagrams,= illustrated and explained. By N.H. SCHNEIDER. 8vo, limp. (S. & C. SERIES, NOS. 3 AND 4.) (_New York_) Part 1. 217 illus. 72 pp. (_1905_) _net_ 1 6 Part 2. 73 pp. (_1909_) _net_ 1 6 =Electrical Instruments and Testing.= By N.H. SCHNEIDER. Third edition. 133 illus. 239 pp. crown 8vo. (_New York, 1907_) _net_ 4 6 =Experimenting with Induction Coils.= By N.H. SCHNEIDER. 26 illus. 73 pp. crown 8vo, limp. (S. & C. SERIES, NO. 5.) (_New York, 1906_) _net_ 1 6 =Study of Electricity for Beginners.= By N.H. SCHNEIDER. 54 illus. 88 pp. crown 8vo, limp. (S. & C. SERIES, NO. 6.) (_New York, 1905_) _net_ 1 6 =Practical Electrics:= a Universal Handybook on Every Day Electrical Matters. Seventh edition, 126 illus. 135 pp. 8vo. (S. & C. SERIES, NO. 13.) (_New York, 1902_) _net_ 1 6 =The Voltaic Accumulator:= an elementary treatise. By E. REYNIER. Translated from the French by J.A. BERLY. 62 illus. 202 pp. 8vo 9 0 =Dry Batteries:= how to Make and Use them. By a DRY BATTERY EXPERT. With additional notes by N.H. SCHNEIDER. 30 illus. 59 pp. crown 8vo, sewed. (S. & C. SERIES, NO. 7.) (_New York, 1905_) _net_ 1 6 =The Diseases of Electrical Machinery.= By E. SCHULZ. Edited, with a Preface, by Prof. S.P. THOMPSON. 42 illus. 84 pp. crown 8vo _net_ 2 0 =Electric Toy-Making.= By T.O. SLOANE. Fifteenth edition, 70 illus. 183 pp. crown 8vo. (_New York, 1903_) _net_ 4 6 =Electricity Simplified.= By T.O. SLOANE. Tenth edition, 29 illus. 158 pp. crown 8vo. (_New York, 1901_) _net_ 4 6 =How to become a Successful Electrician.= By T.O. SLOANE. Third edition, illustrated, crown 8vo. (_New York, 1899_) _net_ 4 6 =Electricity:= its Theory, Sources and Applications. By J.T. SPRAGUE. Third edition, 109 illus. 658 pp. crown 8vo. (_1892_) _net_ 7 6 =Telegraphic Connections.= By C. THOM and W.H. JONES. 20 plates, 59 pp. oblong 8vo. (_New York, 1892_) _net_ 3 6 =Röntgen Rays= and Phenomena of the Anode and Cathode. By E.P. THOMPSON and W.A. ANTHONY. 105 illus. 204 pp. 8vo. (_New York, 1896_) _net_ 4 6 =Dynamo Electric Machinery.= By Prof. S.P. THOMPSON. Seventh edition, demy 8vo. (FINSBURY TECHNICAL MANUAL.) Vol. I. =Continuous-Current Machinery.= With 4 coloured and 30 folding plates, 573 illus. 984 pp. (_1904_) _net_ 1 10 0 Vol. II. =Alternating Current Machinery.= 15 coloured and 24 folding plates, 546 illus. 900 pp. (_1905_) _net_ 1 10 0 =Design of Dynamos= (Continuous Currents). By Prof. S.P. THOMPSON. 4 coloured and 8 folding plates, 243 pp. demy 8vo. (_1903_) _net_ 12 0 =Schedule for Dynamo Design,= issued with the above. 6_d_. each, 4_s_. per doz., or 18_s_. per 100 _net_ =Curves of Magnetic Data for Various Materials.= A reprint on transparent paper for office use of Plate L from Dynamo Electric Machinery, and measuring 25 in. by 16 in. _net_ 0 7 =The Electromagnet.= By C.R. UNDERHILL. 67 illus. 159 pp. crown 8vo. (_New York, 1903_) _net_ 6 6 =Practical Guide to the Testing of Insulated Wires and Cables.= By H.L. WEBB. Fifth edition, 38 illus. 118 pp. crown 8vo. (_New York, 1902_) _net_ 4 6 FOREIGN EXCHANGE. =English Prices with Russian Equivalents= (at Fourteen Rates of Exchange). English prices per lb., with equivalents in roubles and kopecks per pood. By A. ADIASSEWICH. 182 pp. fcap. 32mo, roan. (_1908_) _net_ 1 0 =English Prices with German Equivalents= (at Seven Rates of Exchange). English prices per lb., with equivalents in marks per kilogramme. By St. KOCZOROWSKI. 95 pp. fcap. 32mo, roan. (_1909_) _net_ 1 0 =English Prices with Spanish Equivalents.= At Seven Rates of Exchange. English prices per lb., with equivalents in pesetas per kilogramme. By S. LAMBERT. 95 pp. 32mo, roan. (_1910_) _net_ 1 0 =English Prices with French Equivalents= (at Seven Rates of Exchange). English prices per lb. to francs per kilogramme. By H.P. MCCARTNEY. 97 pp. 32mo, roan. (_1907_) _net_ 1 0 =Principles of Foreign Exchange.= By E. MATHESON. Fourth edition, 54 pp. 8vo, sewed. (_1905_) _net_ 0 3 GAS AND OIL ENGINES. =The Theory of the Gas Engine.= By D. CLERK. Edited by F.E. IDELL. Third edition, 19 illus. 180 pp. 18mo, boards. (_New York, 1903_) _net_ 2 0 =The Design and Construction of Oil Engines.= By A.H. GOLDINGHAM. Third edition, 112 illus. 260 pp. crown 8vo. (_New York, 1910_) _net_ 10 6 =Gas Engine in Principle and Practice.= By A.H. GOLDINGHAM. 107 illus. 195 pp. 8vo, cloth. (_New York, 1907_) _net_ 6 6 =Practical Hand-Book on the Care and Management of Gas Engines.= By G. LIECKFELD. Third edition, square 16mo. (_New York, 1896_) 3 6 =Elements of Gas Engine Design.= By S.A. MOSS. 197 pp. 18mo, boards. (_New York, 1907_) _net_ 2 0 =Gas and Petroleum Engines.= A Manual for Students and Engineers. (FINSBURY TECHNICAL MANUAL.) By Prof. W. ROBINSON. _Third edition in preparation_ GAS LIGHTING. =Gas Analyst's Manual= (incorporating Hartley's "Gas Analyst's Manual" and "Gas Measurement"). By J. ABADY. 102 illustrations, 576 pp. demy 8vo. (_1902_) _net_ 18 0 =Gas Works:= their Arrangement, Construction, Plant and Machinery. By F. COLYER. 31 folding plates, 134 pp. 8vo. (_1884_) _net_ 8 6 =Transactions of the Institution of Gas Engineers.= Edited by WALTER T. DUNN, _Secretary_. Published annually. 8vo _net_ 10 6 =Lighting by Acetylene.= By F. DYE. 75 illus. 200 pp. crown 8vo. (_1902_) _net_ 6 0 =A Comparison of the English and French Methods of Ascertaining the Illuminating Power of Coal Gas.= By A.J. VAN EIJNDHOVEN. Illustrated, crown 8vo. (_1897_) 4 0 =Gas Lighting and Gas Fitting.= By W.P. GERHARD. Second edition, 190 pp. 18mo, boards. (_New York, 1894_) _net_ 2 0 =A Treatise on the Comparative Commercial Values of Gas Coals and Cannels.= By D.A. GRAHAM. 3 plates, 100 pp. 8vo. (_1882_) 4 6 =The Gas Engineer's Laboratory Handbook.= By J. HORNBY. Third edition, revised, 70 illus. 330 pp. crown 8vo. (_1910_) _net_ 6 0 HISTORICAL AND BIOGRAPHICAL. =Extracts from the Private Letters of the late Sir William Fothergill Cooke,= 1836-9, relating to the Invention and Development of the Electric Telegraph; also a Memoir by LATIMER CLARK. Edited by F.H. WEBB. Sec. Inst.E.E. 8vo. (_1895_) 3 0 =A Chronology of Inland Navigation= in Great Britain. By H.R. DE SALIS. Crown 8vo. (1897) 4 6 =A History of Electric Telegraphy= to the year 1837. By J.J. FAHIE. 35 illus. 542 pp. crown 8vo. (_1889_) 2 0 =History and Development of Steam Locomotion on Common Roads.= By W. FLETCHER. 109 illus. 288 pp. 8vo 5 0 =Life as an Engineer:= its Lights, Shades, and Prospects. By J.W.C. HALDANE. 23 plates, 338 pp. crown 8vo. (_1905_) _net_ 5 0 =Philipp Reis,= Inventor of the Telephone: a Biographical Sketch. By Prof. S.P. THOMPSON. 8vo, cloth. (_1883_) 7 6 =The Development of the Mercurial Air Pump.= By Prof. S.P. THOMPSON. Illustrated, royal 8vo, sewed. (_1888_) 1 6 HOROLOGY. =Watch and Clock Maker's Handbook,= Dictionary and Guide. By F.J. BRITTEN. Tenth edition, 450 illus. 492 pp. crown 8vo. (_1902_) _net_ 5 0 =The Springing and Adjusting of Watches.= By F.J. BRITTEN. 75 illus. 152 pp. crown 8vo. (_1898_) _net_ 3 0 =Prize Essay on the Balance Spring= and its Isochronal Adjustments. By M. IMMISCH. 7 illus. 50 pp. crown 8vo. (_1872_) 2 6 HYDRAULICS AND HYDRAULIC MACHINERY. (_See also_ WATER SUPPLY.) =Pumps:= Historically, Theoretically and Practically Considered. By P.R. BJÖRLING. Second edition, 156 illus. 234 pp. crown 8vo. (_1895_) 7 6 =Pump Details.= By P.R. BJÖRLING. 278 illus. 211 pp. crown 8vo. (_1892_) 7 6 =Pumps and Pump Motors:= A Manual for the use of Hydraulic Engineers. By P.R. BJÖRLING. Two vols. 261 plates, 369 pp. royal 4to. (_1895_). _net_ 1 10 0 =Practical Handbook on Pump Construction.= By P.R. BJÖRLING. Second edition, 9 plates, 90 pp. crown 8vo. (_1904_) 5 0 =Water or Hydraulic Motors.= By P.R. BJÖRLING. 206 illus. 287 pp. crown 8vo. (_1903_) 9 0 =Hydraulic Machinery,= with an Introduction to Hydraulics. By R.G. BLAINE. Second edition with 307 illus. 468 pp. 8vo. (FINSBURY TECHNICAL MANUAL). (_1905_) _net_ 14 0 =Practical Hydraulics.= By T. BOX. Fifteenth edition, 8 plates, 88 pp. crown 8vo. (_1909_) _net_ 5 0 =Hydraulic, Steam, and Hand Power Lifting and Pressing Machinery.= By F. COLYER. Second edition, 88 plates, 211 pp. imperial 8vo. (_1892_) _net_ 10 6 =Pumps and Pumping Machinery.= By F. COLYER. Vol. I. Second edition, 53 plates, 212 pp. 8vo (_1892_) _net_ 10 6 Vol. II. Second edition, 48 plates, 169 pp. 8vo. (_1900_) _net_ 10 6 =Construction of Horizontal and Vertical Water-wheels.= By W. CULLEN. Second edition, small 4to. (_1871_) 5 0 =Donaldson's Poncelet Turbine= and Water Pressure Engine and Pump. By W. DONALDSON. 4to. (_1883_) 5 0 =Principles of Construction and Efficiency of Water-wheels.= By W. DONALDSON. 13 illus. 94 pp. 8vo. (_1876_) 5 0 =Practical Hydrostatics and Hydrostatic Formulæ.= By E.S. GOULD. 27 illus. 114 pp. 18mo, boards. (_New York, 1903_) _net_ 2 0 =Hydraulic and other Tables= for purposes of Sewerage and Water Supply. By T. HENNELL. Third edition, 70 pp. crown 8vo. (_1908_) _net_ 4 6 =Hydraulic Tables= for finding the Mean Velocity and Discharge in Open Channels. By T. HIGHAM. Second edition, 90 pp. super-royal 8vo. (_1898_) 7 6 =Tables for Calculating the Discharge of Water= in Pipes for Water and Power Supplies. Indexed at side for ready reference. By A.E. SILK. 63 pp. crown 8vo. (_1899_) 5 0 =Simple Hydraulic Formulæ.= By T.W. STONE. 9 plates, 98 pp. crown 8vo. (_1881_) 4 0 INDUSTRIAL CHEMISTRY AND MANUFACTURES. =Perfumes and their Preparation.= By G.W. ASKINSON. Translated from the Third German Edition by I. FUEST. Third edition, 32 illus. 312 pp. 8vo. (_New York, 1907_) _net_ 12 6 =Brewing Calculations,= Gauging and Tabulation. By C.H. BATER. 340 pp. 64mo, roan, gilt edges. (_1897_) _net_ 1 6 =A Pocket Book for Chemists,= Chemical Manufacturers, Metallurgists, Dyers, Distillers, etc. By T. BAYLEY. Seventh edition, 550 pp. royal 32mo, roan, gilt edges. (_1905_) _net_ 5 0 =Practical Receipts= for the Manufacturer, the Mechanic, and for Home use. By Dr. H.R. BERKELEY and W.M. WALKER. 250 pp. demy 8vo. (_1902_) _net_ 7 6 =A Treatise on the Manufacture of Soap and Candles,= Lubricants and Glycerine. By W.L. CARPENTER and H. LEASK. Second edition, 104 illus. 456 pp. crown 8vo. (_1895_) 12 6 =A Text Book of Paper Making.= By C.F. CROSS and E.J. BEVAN. Third edition, 97 illus. 411 pp. crown 8vo. (_1907_) _net_ 12 6 =C.B.S. Standard Units and Standard Paper Tests.= By C.F. CROSS, E.J. BEVAN, C. BEADLE and R.W. SINDALL. 25 pp. crown 4to. (_1903_) _net_ 2 6 =Soda Fountain Requisites.= A Practical Receipt Book for Druggists, Chemists, etc. By G.H. DUBELLE. Third edition, 157 pp. crown 8vo. (_New York, 1905_) _net_ 4 6 =The Chemistry of Fire= and Fire Prevention. By H. and H. INGLE. 45 illus. 290 pp. crown 8vo. (_1900_) 9 0 =Ice-Making Machines.= By M. Ledoux and others. Sixth edition. 190 pp. 18mo, boards. (_New York, 1906_) _net_ 2 0 =Brewing with Raw Grain.= By T.W. Lovibond. 75 pp. crown 8vo. (1883) 5 0 =Sugar, a Handbook for Planters and Refiners.= By the late J.A.R. NEWLANDS and B.E.R. NEWLANDS. 236 illus. 876 pp. demy 8vo. (_London, 1909_) _net_ 1 5 0 =Principles of Leather Manufacture.= By Prof. H.R. PROCTER. 101 illus. 520 pp. medium 8vo. (_1908_) _net_ 18 0 =Leather Industries Laboratory Handbook= of Analytical and Experimental methods. By H.R. PROCTER. Second edition, 4 plates, 46 illus. 450 pp. demy 8vo. (_1908_) _net_ 18 0 =Theoretical and Practical Ammonia Refrigeration.= By I.I. REDWOOD. Sixth thousand, 15 illus. 146 pp. square 16mo. (_New York, 1909_) _net_ 4 6 =Breweries and Maltings.= By G. SCAMMELL and F. COLYER. Second edition, 20 plates, 178 pp. 8vo. (_1880_) _net_ 6 0 =Factory Glazes for Ceramic Engineers.= By H. RUM-BELLOW. Folio. Series A, Leadless Sanitary Glazes. (_1908_) _net_ 2 2 0 =Text Book of Physical Chemistry.= By C.L. SPEYERS. 224 pp. demy 8vo. (_New York, 1898_) 9 0 =Spons' Encyclopædia of the Industrial Arts,= Manufactures and Commercial Products. 1500 illus. 2100 pp. super-royal 8vo. (_1882_) In 2 Vols. cloth _net_ 2 2 0 =Pigments, Paints and Painting.= By G. TERRY. 49 illus. 392 pp. crown 8vo. (_1893_) 7 6 =Tables for the Quantitative Estimation of the Sugars.= By E. WEIN and W. FREW. Crown 8vo. (_1896_) 6 0 =Workshop Receipts.= For the use of Manufacturers, Mechanics and Scientific Amateurs. New and thoroughly revised edition, crown 8vo. (_1909_) each _each net_ 3 0 Vol. I. ACETYLENE LIGHTING _to_ DRYING. 223 illus. 532 pp. Vol. II. DYEING _to_ JAPANNING. 259 illus. 540 pp. Vol. III. JOINTING PIPES _to_ PUMPS. 256 illus. 528 pp. Vol. IV. RAINWATER SEPARATORS _to_ WINES. 250 illus. 520 pp. =Practical Handbook on the Distillation of Alcohol from Farm Products.= By F.B. WRIGHT. Second edition, 60 illus. 271 pp. crown 8vo. (_New York, 1907_) ... ... _net_ 4 6 =The Manufacture of Chocolate= and other Cacao Preparations. By P. ZIPPERER. Second edition, 87 illus. 280 pp. royal 8vo. (_1902_) _net_ 16 0 IRRIGATION. =The Irrigation Works of India.= By R.B. BUCKLEY. Second edition, with coloured maps and plans. 336 pp. 4to, cloth. (_1905_) _net_ 2 2 0 =Facts, Figures, and Formulæ for Irrigation Engineers.= By R.B. BUCKLEY. With illus. 239 pp. large 8vo. (_1908_) _net_ 10 6 =Irrigated India.= By Hon. ALFRED DEAKIN. With Map, 322 pp. 8vo. (_1893_) 8 6 =Indian Storage Reservoirs,= with Earthen Dams. By W.L. STRANGE. 14 plates and 53 illus. 379 pp. demy 8vo. (_1904_) _net_ 1 1 0 =Irrigation Farming.= By L.M. WILCOX. Revised edition, 113 illus. 494 pp. crown 8vo. (_New York_) _net_ 8 6 =Egyptian Irrigation.= By Sir W. WILLCOCKS. Second edition out of Print. _A few copies of the First Edition (_1889_) are still to be had. Price 15s. net._ =The Nile Reservoir Dam at Assuan,= and After. By Sir _W. WILLCOCKS._ Second edition, 13 plates, super-royal 8vo. (_1903_) _net_ 6 0 =The Assuan Reservoir and Lake Moeris.= By Sir W. WILLCOCKS. With text in English, French and Arabic. 5 plates, 116 pp. super-royal 8vo. (_1904_) _net_ 5 0 =The Nile in 1904.= By Sir W. Willcocks. 30 plates, 200 pp. super-royal 8vo. (_1904_) _net_ 9 0 LOGARITHM TABLES. =Aldum's Pocket Folding Mathematical Tables.= Four-figure logarithms, and Anti-logarithms, Natural Sines, Tangents, Cotangents, Cosines, Chords and Radians for all angles from 1 to 90 degrees. On folding card. _Net_ 4_d._ 20 copies, _net_ 6_s._ =Tables of Seven-figure Logarithms= of the Natural Numbers from 1 to 108,000. By C. BABBAGE. Stereotype edition, 8vo 7 6 =Short Logarithmic= and other Tables. By W.C. UNWIN. Fourth edition, small 4to 3 0 =Logarithmic Land Measurement.= By J. WALLACE. 32 pp. royal 8vo. (_1910_) _net_ 5 0 =A.B.C. Five-figure Logarithms with Tables, for Chemists.= By C.J. WOODWARD. Crown 8vo _net_ 2 6 =A.B.C. Five-figure Logarithms= for general use, with lateral index for ready reference. By C.J. WOODWARD. Second edition, with cut lateral Index, 116 pp. 12mo, limp leather _net_ 3 0 MARINE ENGINEERING AND NAVAL ARCHITECTURE. =Marine Propellers.= By S.W. BARNABY. Fifth edition, 5 plates, 56 illus. 185 pp. demy 8vo. (_1908_) _net_ 10 6 =Marine Engineer's Record Book:= Engines. By B.C. BARTLEY. 8vo, roan _net_ 5 0 =The Engineer's and Draughtsman's Data Book= for Workshop and Office Use. Third edition, crown 8vo, roan 3 0 =Yachting Hints,= Tables and Memoranda. By A.C. FRANKLIN. Waistcoat pocket size, 103 pp. 64mo, roan, gilt edges _net_ 1 0 =Steamship Coefficients, Speeds and Powers.= By C.F.A. FYFE. 31 plates, 280 pp. fcap. 8vo, leather. (_1907_) _net_ 10 6 =Steamships and Their Machinery,= from first to last. By J.W.C. HALDANE. 120 illus. 532 pp. 8vo. (_1893_) 15 0 =Tables for Constructing Ships' Lines.= By A. HOGG. Second edition, 8vo 7 0 =Submarine Boats.= By G.W. HOVGAARD. 2 plates, 98 pp. crown 8vo. (_1887_) 5 0 =Tabulated Weights= of Angle, Tee, Bulb, Round, Square, and Flat Iron and Steel for the use of Naval Architects, Ship-builders, etc. By C.H. JORDAN. Sixth edition, 640 pp. royal 32mo, French morocco, gilt edges. (_1909_) _net_ 7 6 =Particulars of Dry Docks,= Wet Docks, Wharves, etc. on the River Thames. Compiled by C.H. JORDAN. Second edition, 7 coloured charts, 103 pp. oblong 8vo. (_1904_) _net_ 2 6 =Marine Transport of Petroleum.= By H. LITTLE. 66 illus. 263 pp. crown 8vo. (_1890_) 10 6 =Questions and Answers for Marine Engineers,= with a Practical Treatise on Breakdowns at Sea. By T. LUCAS. 12 folding plates, 515 pp. gilt edges, crown 8vo. (_New York, 1902_) _net_ 8 0 =Reed's Examination Papers for Extra First Class Engineers=. Fourth edition, 14 plates and 188 illus. 550 pp. 8vo. (_1902_) _net_ 18 0 =Reed's Engineers' Handbook to the Board of Trade Examinations= for certificates of Competency as First and Second Class Engineers. Nineteenth edition, 37 plates, 358 illus. 696 pp. 8vo _net_ 14 0 =Reed's Marine Boilers.= Second edition, crown 8vo _net_ 4 6 =Reed's Useful Hints to Sea-going Engineers.= Fourth edition, 8 plates, 50 illus. 312 pp. crown 8vo. (_1903_) _net_ 3 6 MATERIALS. =Practical Treatise on the Strength of Materials.= By T. BOX. Fourth edition, 27 plates, 536 pp. 8vo. (_1902_) _net_ 12 6 =Treatise on the Origin, Progress, Prevention and Cure of Dry Rot in Timber.= By T.A. BRITTON. 10 plates, 519 pp. crown 8vo. (_1875_) 7 6 =Twenty Years' Practical Experience of Natural Asphalt= and Mineral Bitumen. By W.H. DELANO. 33 illus. 73 pp. crown 8vo, parchment. (_1893_) 2 0 =Stone:= how to get it and how to use it. By Major-Gen. C.E. LUARD, R.E. 8vo, sewed. (_1890_) 2 0 =Testing of Pipes= and Pipe-joints in the Open Trenches. By M.M. PATERSON. 8vo, sewed (_1879_) 2 0 =Solid Bitumens.= By S.F. PECKHAM. 23 illus. 324 pp. 8vo. (_New York, 1909_) _net_ 1 1 0 =Lubricants, Oils and Greases.= By I.I. REDWOOD. 3 plates, 8vo. (_1898_) _net_ 6 6 =Practical Treatise on Mineral Oils= and their By-Products. By I.I. REDWOOD. 67 illus. 336 pp. demy 8vo. (_1897_) 15 0 =Silico-Calcareous Sandstones,= or Building Stones from Quartz, Sand and Lime. By E. STOFFLER. 5 plates, 8vo, sewed. (_1901_) _net_ 4 0 =Proceedings of the Fifth Congress, International Association for Testing Materials.= English edition. 189 illus. 549 pp. demy 8vo. (_1910_). Paper _net_ 15 0 Cloth _net_ 18 0 MATHEMATICS. =Imaginary Quantities.= By M. ARGAND. Translated by PROF. HARDY. 18mo, boards. (_New York_) _net_ 2 0 =Text Book of Practical Solid Geometry.= By E.H. DE V. ATKINSON. Revised by MAJOR B.R. WARD, R.E. Second edition, 17 plates, 8vo. (_1901_) 7 6 =Quick and Easy Methods of Calculating,= and the Theory and Use of the Slide Rule. By R.G. BLAINE. Third edition, 6 illus. 152 pp. 16mo, leather cloth. (_1907_) 2 6 =Symbolic Algebra,= or the Algebra of Algebraic Numbers. By W. CAIN. 18mo, boards. (_New York_) _net_ 2 0 =Nautical Astronomy.= By J.H. COLVIN. 127 pp. crown, 8vo. (_1901_) _net_ 2 6 =Chemical Problems.= By J.C. FOYE. Fourth edition, 141 pp. 18mo, boards. (_New York, 1898_) _net_ 2 0 =Primer of the Calculus.= By E.S. GOULD. Second edition, 24 illus. 122 pp. 18mo, boards. (_New York, 1899_) _net_ 2 0 =Elementary Treatise on the Calculus= for Engineering Students. By J. GRAHAM. Third edition, 276 pp. crown 8vo. (_1905_). (FINSBURY TECHNICAL MANUAL) 7 6 =Manual of the Slide Rule.= By F.A. HALSEY. Second edition, 31 illus. 84 pp. 18mo, boards. (_New York, 1901_) _net_ 2 0 =Reform in Chemical and Physical Calculations.= By C.J.T. HANSSEN. 4to. (_1897_) _net_ 6 6 =Algebra Self-Taught.= By P. HIGGS. Third edition, 104 pp. crown 8vo. (_1903_) 2 6 =Galvanic Circuit investigated Mathematically.= By G.S. OHM. Translated by WILLIAM FRANCIS. 269 pp. 18mo, boards. (_New York, 1891_) _net_ 2 0 =Elementary Practical Mathematics.= By M.T. ORMSBY. 420 pp. demy 8vo. (_1900_) _net_ 7 6 =Elements of Graphic Statics.= By K. VON OTT. Translated by G.S. CLARKE. 93 illus. 128 pp. crown 8vo. (_1901_) 5 0 =Figure of the Earth.= By F.C. ROBERTS. 18mo, boards. (_New York_) _net_ 2 0 =Arithmetic of Electricity.= By T. O'C. SLOANE. Thirteenth edition, crown 8vo. (_New York, 1901_) _net_ 4 6 =Graphic Method for Solving certain Questions in Arithmetic or Algebra.= By G.L. VOSE. Second edition with 28 illus. 62 pp. 18mo, boards. (_New York, 1902_) _net_ 2 0 =Problems in Electricity.= A Graduated Collection comprising all branches of Electrical Science. By R. WEBER. Translated from the French by E.A. O'KEEFE. 34 illus. 366 pp. crown 8vo. (_1902_). _net_ 7 6 MECHANICAL ENGINEERING. STEAM ENGINES AND BOILERS, ETC. =Handbook for Mechanical Engineers.= By HY. ADAMS. Fourth edition, 426 pp. crown 8vo. (_1897_) _net_ 4 6 =Appleby's Handbooks of Machinery.= Many illustrations, 8vo. Sections 2, 3, 4 and 6 _each_ 3 6 Section 5 5 0 Section 1.--Prime Movers. _Out of Print._ Section 2.--Hoisting Machinery, Winding Engines, etc. Section 3.--_Out of print._ Section 4.--Machine Tools and Accessories. Section 5.--Contractors' Plant and Railway Materials. Section 6.--Mining, Colonial and Manufacturing Machinery. =Engineers' Sketch Book of Mechanical Movements.= By T.W. BARBER. Fifth edition, 3000 illus. 355 pp. 8vo. (_1906_) _net_ 10 6 =The Repair and Maintenance of Machinery.= By T.W. BARBER. 417 illus. 476 pp. 8vo. (_1895_) 10 6 =Slide Valve and its Functions=, with special reference to Modern Practice in the United States. By J. BEGTRUP. 90 diagrams, 146 pp. medium 8vo. (_New York, 1902_) _net_ 8 0 =Practical Treatise on Mill Gearing.= By T. BOX. Fifth edition, 11 plates, 128 pp. crown 8vo. (_1892_) 7 6 =Safety Valves.= By R.H. BUELL. Third edition, 20 illus. 100 pp. 18mo, boards. (_New York, 1898_) _net_ 2 0 =Machine Design.= By Prof. W.L. CATHCART. Part I. FASTENINGS. 123 illus. 291 pp. demy 8vo. (_New York, 1903_) _net_ 12 6 =Chimney Design and Theory.= By W.W. CHRISTIE. Second edition, 54 illus. 192 pp. crown 8vo. (_New York, 1902_) _net_ 12 6 =Furnace Draft:= its Production by Mechanical Methods. By W.W. CHRISTIE. 5 illus. 80 pp. 18mo, boards. (_New York, 1906_) _net_ 2 0 =Working and Management of Steam Boilers and Engines.= By F. COLYER. Second edition, 108 pp. crown 8vo. (_1902_) 3 6 =The Stokers' Catechism.= By W.J. CONNOR. 63 pp. limp cloth. (_1906_) _net_ 1 0 =Treatise on the use of Belting for the Transmission of Power.= By J.H. COOPER. Fifth edition, 94 illus. 399 pp. demy 8vo. (_New York, 1901_) _net_ 12 6 =The Steam Engine considered as a Thermodynamic Machine.= By J.H. COTTERILL. Third edition, 39 diagrams, 444 pp. 8vo. (_1896_) 15 0 =Fireman's Guide=, a Handbook on the Care of Boilers. By K.P. DAHLSTROM. Ninth edition fcap. 8vo. (_New York, 1902_) _net_ 1 6 =Heat for Engineers.= By C.R. DARLING. 110 illus. 430 pp. 8vo. (_1908._) (FINSBURY TECHNICAL MANUAL.) _net_ 12 6 =Diseases of a Gasolene Automobile=, and How to Cure Them. By A.L. DYKE and G.P. DORRIS. 127 illus. 201 pp. crown 8vo. (_New York, 1903_) _net_ 6 6 =Belt Driving.= By G. HALLIDAY. 3 folding plates, 100 pp. 8vo. (_1894_) 3 6 =Worm and Spiral Gearing.= By F.A. HALSEY. 13 plates, 85 pp. 18mo, boards. (_New York, 1903_) _net_ 2 0 =Commercial Efficiency of Steam Boilers.= By A. HANSSEN. Large 8vo, sewed. (1898) 0 6 =Corliss Engine.= By J.T. HENTHORN. Third edition, 23 illus. 95 pp. square 16mo. (S. & C. SERIES, No. 20.) (_New York, 1910_) _net_ 1 6 =Liquid Fuel= for Mechanical and Industrial Purposes. By E.A. BRAYLEY HODGETTS. 106 illus. 129 pp. 8vo. (_1890_) 5 0 =Elementary Text-Book on Steam Engines and Boilers.= By J.H. KINEALY. Fourth edition, 106 illus. 259 pp. 8vo. (_New York, 1903_) _net_ 8 6 =Centrifugal Fans.= By J.H. KINEALY. 33 illus. 206 pp. fcap. 8vo, leather. (_New York, 1905_) _net_ 12 6 =Mechanical Draft.= By J.H. KINEALY. 27 original tables and 13 plates, 142 pp. crown 8vo. (_New York, 1906_) _net_ 8 6 =The A.B.C. of the Steam Engine=, with a description of the Automatic Governor. By J.P. LISK. 6 plates, 12mo. (S. & C. SERIES, No. 17.) (_New York, 1910_) _net_ 1 6 =Valve Setting Record Book.= By P.A. LOW. 8vo, boards. 1 6 =The Lay-out of Corliss Valve Gears.= By S.A. MOSS. Second edition, 3 plates, 108 pp. 18mo, boards. (_New York, 1906_) _net_ 2 0 =Steam Boilers=, their Management and Working. By J. PEATTIE. Fifth edition, 35 illus. 230 pp. crown 8vo. (_1906_) _net_ 4 6 =Treatise on the Richards Steam Engine Indicator.= By C.T. PORTER. Sixth edition, 3 plates and 73 diagrams, 285 pp. 8vo. (_1902_) 9 0 =Practical Treatise on the Steam Engine.= By A. RIGG. Second edition, 103 plates, 378 pp. demy 4to. (_1894_) 1 5 0 =Power and its Transmission.= A Practical Handbook for the Factory and Works Manager. By T.A. SMITH. 76 pp. fcap. 8vo. (_1910_) _net_ 2 0 =Drawings for Medium Sized Repetition Work.= By R.D. SPINNEY. With 47 illus. 130 pp. 8vo. (_1909_) _net_ 3 6 =Slide Valve Simply Explained.= By W.J. TENNANT. Revised by J.H. KINEALY. 41 illus. 83 pp. crown 8vo. (_New York, 1899_) _net_ 4 6 =Shaft Governors.= By W. TRINKS and C. HOOSUM. 27 illus. 97 pp. 18mo, boards. (_New York, 1905_) _net_ 2 0 =Slide and Piston Valve Geared Steam Engines.= By W.H. UHLAND. 47 plates and 314 illus. 155 pp. Two vols. folio, half morocco. (_1882_) 1 16 0 =How to run Engines and Boilers.= By E.P. WATSON. Fifth edition, 31 illus. 160 pp. crown 8vo. (_New York, 1904_) 3 6 =Position Diagram of Cylinder with Meyer Cut-off.= By W.H. WEIGHTMAN. On card. (_New York_) _net_ 1 0 =Practical Method of Designing Slide Valve Gearing.= By E.J. WELCH. 69 diagrams, 283 pp. Crown 8vo. (_1890_) 6 0 =Elements of Mechanics.= By T.W. WRIGHT. Eighth edition, illustrated, 382 pp. 8vo. (_New York, 1909_) _net_ 10 6 METALLURGY. IRON AND STEEL MANUFACTURE. =Life of Railway Axles.= By T. ANDREWS. 8vo, sewed. (_1895_) 1 0 =Microscopic Internal Flaws in Steel Rails and Propeller Shafts.= By T. ANDREWS. 8vo, sewed. (_1896_) 1 0 =Microscopic Internal Flaws, Inducing Fracture in Steel.= By T. ANDREWS. 8vo, sewed. (_1896_) 2 0 =Relations between the Effects of Stresses= slowly applied and of Stresses suddenly applied in the case of Iron and Steel: Comparative Tests with Notched and Plain Bars. By P. BREUIL. 23 plates and 60 illus. 151 pp. 8vo. (_1904_) _net_ 8 0 =Brassfounders' Alloys.= By J.F. BUCHANAN. Illustrated, 129 pp. crown 8vo. (_1905_) _net_ 4 6 =Foundry Nomenclature.= The Moulder's Pocket Dictionary and concise guide to Foundry Practice. By JOHN F. BUCHANAN. Illustrated, 225 pp. crown 8vo. (_1903_) _net_ 5 0 =American Standard Specifications for Steel.= By A.L. COLBY. Second edition, revised, 103 pp. crown 8vo. (_New York, 1902_) _net_ 5 0 =Galvanised Iron=: its Manufacture and Uses. By J. DAVIES. 139 pp. 8vo. (_1899_) _net_ 5 0 =Management of Steel.= By G. EDE. Seventh edition, 216 pp. crown 8vo. (_1903_) 5 0 =Galvanising and Tinning=, with a special Chapter on Tinning Grey Iron Castings. By W.T. FLANDERS. 8vo. (_New York_) _net_ 8 6 =Cupola Furnace.= A practical treatise on the Construction and Management of Foundry Cupolas. By E. KIRK. Third edition, 78 illus. 450 pp. demy 8vo. (_New York, 1910_) _net_ 15 0 =Practical Notes on Pipe Founding.= By J.W. MACFARLANE. 15 plates, 148 pp. 8vo 12 6 =Atlas of Designs concerning Blast Furnace Practice.= By M.A. PAVLOFF. 127 plates, 14 in. by 10½ in. oblong, sewed. (_1902_) _net_ 1 1 0 =Album of Drawings relating to the Manufacture of Open Hearth Steel.= By M.A. PAVLOFF. Part I. Open Hearth Furnaces. 52 plates, 14 in. by 10½ in. oblong folio in portfolio. (_1904_) _net_ 12 0 =Metallography Applied to Siderurgic Products.= By H. SAVOIA. Translated by R.G. CORBET. With 94 illus. 180 pp. crown 8vo. (_1910_) _net_ 4 6 =Modern Foundry Practice.= Including revised subject matter and tables from SPRETSON'S "Casting and Founding." By J. SHARP. Second edition, 272 illus. 759 pp. 8vo. (_1905_) _net_ 1 1 0 =Roll Turning for Sections in Steel and Iron.= By A. SPENCER. Second edition, 78 plates, 4to. (_1894_) 1 10 0 METRIC TABLES. =French Measure and English Equivalents.= By J. BROOK. Second edition, 80 pp. fcap. 32mo, roan. (_1906_) _net_ 1 0 =A Dictionary of Metric and other useful Measures.= By L. CLARK. 113 pp. 8vo. (_1891_) 6 0 =English Weights, with their Equivalents in kilogrammes per cent.= By F.W.A. LOGAN. 96 pp. fcap. 32mo, roan. (_1906_) _net_ 1 0 =Metric Weights with English Equivalents.= By H.P. MCCARTNEY. 84 pp. fcap. 32mo. (_1907_) _net_ 1 0 =Metric Tables.= By Sir G.L. MOLESWORTH. Fourth edition, 95 pp. royal 32mo. (_1909_) _net_ 2 0 =Tables for Setting out Curves= from 200 metres to 4000 metres by tangential angles. By H. WILLIAMSON. 4 illus. 60 pp. 18mo. (_1908_) _net_ 2 0 MINERALOGY AND MINING. =Rock Blasting.= By G.G. ANDRE. 12 plates and 56 illus. in text, 202 pp. 8vo. (_1878_) 5 0 =Winding Plants for Great Depth.= By H.C. BEHR. In two parts. 8vo, sewed. (_1902_) _net_ 2 2 0 =Practical Treatise on Hydraulic Mining in California.= By A.J. BOWIE, Jun. Tenth edition, 73 illus. 313 pp. royal 8vo. (_New York, 1905_) _net_ 1 1 0 =Manual of Assaying Gold, Silver, Copper and Lead Ores.= By W.L. BROWN. Twelfth edition, 132 illus. 589 pp. crown 8vo. (_New York, 1907_) _net_ 10 6 =Fire Assaying.= By E.W. BUSKETT. 69 illus. 105 pp. crown 8vo. (_New York, 1907_) _net_ 4 6 =Tin=: Describing the Chief Methods of Mining, Dressing, etc. By A.G. CHARLETON. 15 plates, 83 pp. crown 8vo. (_1884_) 12 6 =Gold Mining and Milling= in Western Australia, with Notes upon Telluride Treatment, Costs and Mining Practice in other Fields. By A.G. CHARLETON. 82 illus. and numerous plans and tables, 648 pp. super-royal 8vo. (_1903_) _net_ 1 5 0 =Miners' Geology and Prospectors' Guide.= By G.A. CORDER. 29 plates, 224 pp. crown 8vo. (_1907_) _net_ 5 0 =Blasting of Rock in Mines, Quarries, Tunnels, etc.= By A.W. and Z.W. DAW. Second edition, 90 illus. 316 pp. demy 8vo. (_1909_) _net_ 15 0 =Handbook of Mineralogy=; determination and description of Minerals found in the United States. By J.C. FOYE. 18mo, boards. (_New York, 1886_) _net_ 2 0 =Conversations on Mines.= By W. HOPTON. Ninth edition, 33 illus. 356 pp. crown 8vo. (_1891_) 4 6 =Our Coal Resources= at the End of the Nineteenth Century. By Prof. E. HULL. 157 pp. demy 8vo. (_1897_) 6 0 =Hydraulic Gold Miners' Manual.= By T.S.G. KIRKPATRICK. Second edition, 12 illus. 46 pp. crown 8vo. (_1897_) 4 0 =Economic Mining.= By C.G.W. LOCK. 175 illus. 680 pp. 8vo. (_1895_) _net_ 10 6 =Gold Milling=: Principles and Practice. By C.G.W. LOCK. 200 illus. 850 pp. demy 8vo. (_1901_) _net_ 1 1 0 =Mining and Ore-Dressing Machinery.= By C.G.W. LOCK. 639 illus. 466 pp. super-royal 4to. (_1890_) 1 5 0 =Miners' Pocket Book.= By C.G.W. LOCK. Fifth edition, 233 illus. 624 pp. fcap. 8vo, roan, gilt edges. (_1908_) _net_ 10 6 =Tests for Ores, Minerals and Metals of Commercial Value.= By R.L. MCMECHEN. 152 pp. 12mo. (_New York, 1907_) _net_ 5 6 =Practical Handbook for the Working Miner and Prospector=, and the Mining Investor. By J.A. MILLER. 34 illus. 234 pp. crown 8vo. (_1897_) 7 6 =Theory and Practice of Centrifugal Ventilating Machines.= By D. MURGUE. 7 illus. 81 pp. 8vo. (_1883_) 5 0 =Examples of Coal Mining Plant.= By J. POVEY-HARPER. Second edition, 40 plates, 26 in. by 20 in. (_1895_) _net_ 4 4 0 =Examples of Coal Mining Plant, Second Series.= By J. POVEY-HARPER. 10 plates, 26 in. by 20 in. (_1902_) _net_ 1 12 6 ORGANISATION. ACCOUNTS, CONTRACTS AND MANAGEMENT. =Organisation of Gold Mining Business=, with Specimens of the Departmental Report Books and the Account Books. By NICOL BROWN. Second edition, 220 pp. fcap. folio. (_1903_) _net_ 1 5 0 =Manual of Engineering Specifications= and Contracts. By L.M. HAUPT. Eighth edition, 338 pp. 8vo. (_New York, 1900_) _net_ 12 6 =Depreciation of Factories=, Municipal, and Industrial Undertakings, and their Valuation. By E. MATHESON. Fourth edition, 230 pp. 8vo, cloth. (_1910_) _net_ 10 6 =Aid Book to Engineering Enterprise.= By E. MATHESON. Third edition, 916 pp. 8vo, buckram. (_1898_) 1 4 0 =Office Management.= A handbook for Architects and Civil Engineers. By W. KAYE PARRY. New impression, 187 pp. medium 8vo. (_1908_) _net_ 5 0 =Commercial Organisation of Engineering Factories.= By H. SPENCER. 92 illus. 221 pp. 8vo. (_1907_) _net_ 10 6 PHYSICS. COLOUR, HEAT AND EXPERIMENTAL SCIENCE. =The Entropy Diagram= and its Applications. By M.J. BOULVIN. 38 illus. 82 pp. demy 8vo. (_1898_) 5 0 =Physical Problems and their Solution.= By A. BOURGOUGNON. 224 pp. 18mo, boards. (_New York, 1897_) _net_ 2 0 =Heat for Engineers.= By C.R. DARLING. 110 illus. 430 pp. 8vo. (_1908_) (FINSBURY TECHNICAL MANUAL) _net_ 12 6 =The Colourist.= A method of determining colour harmony. By J.A.H. HATT. 2 coloured plates, 80 pp. 8vo. (_New York, 1908_) _net_ 6 6 =Engineering Thermodynamics.= By C.F. HIRSCHFELD. 22 illus. 157 pp. 18mo, boards. (_New York, 1907_) _net_ 2 0 =Experimental Science=: Elementary, Practical and Experimental Physics. By G.M. HOPKINS. Twenty-third edition, 920 illus. 1100 pp. large 8vo. (_New York, 1902_) _net_ 1 1 0 =Reform in Chemical and Physical Calculations.= By C.J.T. HANSSEN. Demy 4to. (_1897_) _net_ 6 6 =Introduction to the Study of Colour Phenomena.= By J.W. LOVIBOND. 10 hand coloured plates, 48 pp. 8vo. (_1905_) _net_ 5 0 =Practical Laws and Data on the Condensation of Steam in Bare Pipes=; to which is added a Translation of PECLET'S Theory and Experiments on the Transmission of Heat through Insulating Materials. By C.P. PAULDING. 184 illus. 102 pp. demy 8vo. (_New York, 1904_) _net_ 8 6 =The Energy Chart.= Practical application to reciprocating steam-engines. By Captain H.R. SANKEY. 157 illus. 170 pp. 8vo. (_1907_) _net_ 7 6 PRICE BOOKS. =Approximate Estimates.= By T.E. COLEMAN. Third edition, 481 pp. oblong 32mo, leather. (_1907_) _net_ 5 0 =Railway Stores Price Book.= By W.O. KEMPTHORNE. 500 pp. demy 8vo. (_1909_) _net_ 10 6 =Spons' Engineers' Price Book.= A Synopsis of Current Prices and Rates for Engineering Materials and Products. Edited by T.G. MARLOW. 650 pp. folio. (_1904_) _net_ 7 6 =Spons' Architects' and Builders' Pocket Price Book=, Memoranda, Tables and Prices. Edited by CLYDE YOUNG. Revised by STANFORD M. BROOKS. Illustrated, 552 pp. 16mo, leather cloth (size 6½ in. by 3¾ in. by ½ in. thick). Issued annually _net_ 3 0 RAILWAY ENGINEERING. =Practical Hints to Young Engineers Employed on Indian Railways.= By A.W.C. ADDIS. With 14 illus. 154 pp. 12mo. (_1910_) _net_ 3 6 =Railroad Curves and Earthwork.= By C.F. ALLEN. Third edition, 4 plates, 198 pp. 12mo, leather, gilt edges. (_New York, 1903_) _net_ 8 6 =Field and Office Tables=, specially applicable to Railroads. By C.F. ALLEN. 293 pp. 16mo, leather. (_New York, 1903_) _net_ 8 6 _The two above combined in one vol. limp leather_ _net_ 12 6 =Up-to-date Air Brake Catechism.= By R.H. BLACKALL. Twenty-third edit. 5 coloured plates, 96 illus. 305 pp. crown 8vo. (_New York, 1908_) _net_ 8 6 =Simple and Automatic Vacuum Brakes.= By C. BRIGGS, G.N.R. 11 plates, 8vo. (_1892_) 4 0 =Notes on Permanent-way Material=, Plate-laying, and Points and Crossings. By W.H. COLE. Fifth edition, 32 plates, 176 pp. crown 8vo. (_1905_) _net_ 7 6 =Statistical Tables of the Working of Railways= in various countries up to the year 1904. By J.D. DIACOMIDIS. Second edition, 84 pp. small folio, sewed. (_1906_) _net_ 16 0 =Locomotive Breakdowns=, Emergencies and their Remedies. By GEO. L. FOWLER, M.E. and W.W. WOOD. Fifth edition, 92 illus. 266 pp. 12mo. (_New York, 1908_) _net_ 4 6 =Permanent-Way Diagrams.= By F.H. FRERE. Mounted on linen in cloth covers. (_1908_) _net_ 3 0 =Formulæ for Railway Crossings and Switches.= By J. GLOVER. 9 illus. 28 pp. royal 32mo. (_1896_) 2 6 =Data relating to Railway Curves and Super elevations=, shown graphically. By J.H. HAISTE. On folding card for pocket use _net_ 0 6 =Setting out of Tube Railways.= By G.M. HALDEN. 9 plates, 46 illus. 68 pp. crown 4to. (_1907_) _net_ 10 6 =Railway Engineering, Mechanical and Electrical.= By J.W.C. HALDANE, 141 illus. 563 pp. 8vo. (_1897_) 15 0 =Tables for setting-out Railway Curves.= By C.P. HOGG. A series of cards in neat cloth case 4 6 =The Construction of the Modern Locomotive.= By G. HUGHES. 300 illus. 261 pp. 8vo. (_1894_) 9 0 =Practical Hints for Light Railways= at Home and Abroad. By F.R. JOHNSON. 6 plates, 31 pp. crown 8vo. (_1896_) 2 6 =Handbook on Railway Stores Management.= By W.O. KEMPTHORNE. 268 pp. demy 8vo. (_1907_) _net_ 10 6 =Railway Stores Price Book.= By W.O. KEMPTHORNE. 487 pp. demy 8vo. (_1909_) _net_ 10 6 =Tables for setting out Curves= for Railways, Roads, Canals, etc. By A. KENNEDY and R.W. HACKWOOD. 32mo _net_ 2 0 =Railroad Location Surveys and Estimates.= By F. LAVIS. 68 illus. 270 pp. 8vo. (_New York, 1906_) _net_ 12 6 =Tables for Computing the Contents of Earthwork= in the Cuttings and Embankments of Railways. By W. MACGREGOR. Royal 8vo 6 0 =Bridge and Tunnel Centres.= By J.B. MCMASTERS. Illustrated, 106 pp. 18mo, boards. (_New York, 1893_) _net_ 2 0 =Pioneering.= By F. SHELFORD. Illustrated, 88 pp. crown 8vo. (_1909_) _net_ 3 0 =Handbook on Railway Surveying= for Students and Junior Engineers. By B. STEWART. 55 illus. 98 pp. crown 8vo. (_1909_) _net_ 2 6 =Spiral Tables.= By J.G. SULLIVAN. 47 pp. 12mo, leather. (_New York, 1908_) _net_ 6 6 =Modern British Locomotives.= By A.T. TAYLOR. 100 diagrams of principal dimensions, 118 pp. oblong 8vo. (_1907_) _net_ 4 6 =Locomotive Slide Valve Setting.= By C.E. TULLY. Illustrated, 18mo _net_ 1 0 =The Walschaert Locomotive Valve Gear.= By W.W. WOOD. 4 plates and set of movable cardboard working models of the valves, 193 pp. crown 8vo. (_New York, 1907_) _net_ 6 6 =The Westinghouse E.T. Air-Brake Instruction Pocket Book.= By W.W. WOOD. 48 illus. including many coloured plates, 242 pp. crown 8vo. (_New York, 1909_) _net_ 8 6 SANITATION, PUBLIC HEALTH AND MUNICIPAL ENGINEERING. =Sewers and Drains for Populous Districts.= By J.W. ADAMS. Ninth edition, 81 illus. 236 pp. 8vo. (_New York, 1902_) _net_ 10 6 =Public Abattoirs=, their Planning, Design and Equipment. By R.S. AYLING. 33 plates, 100 pp. demy 4to. (_1908_) _net_ 8 6 =Sewage Purification.= By E. BAILEY-DENTON. 8 plates, 44 pp. 8vo. (_1896_) 5 0 =Water Supply and Sewerage of Country Mansions= and Estates. By E. BAILEY-DENTON. 76 pp. crown 8vo. (_1901_) _net_ 2 6 =Sewerage and Sewage Purification.= By M.N. BAKER. Second edition, 144 pp. 18mo, boards. (_New York, 1905_) _net_ 2 0 =Sewage Irrigation by Farmers.= By R.W.P. BIRCH. 8vo, sewed. (_1878_) 2 6 =Sanitary House Drainage=, its Principles and Practice. By T.E. COLEMAN. 98 illus. 206 pp. crown 8vo. (_1896_) 6 0 =Stable Sanitation and Construction.= By T.E. COLEMAN. 183 illus. 226 pp. crown 8vo. (_1897_) 6 0 =Public Institutions=, their Engineering, Sanitary and other Appliances. By F. COLYER. 231 pp. 8vo. (_1889_) _net_ 2 0 =Discharge of Pipes and Culverts.= By P.M. CROSTHWAITE. Large folding sheet in case. _net_ 2 6 =A Complete and Practical Treatise on Plumbing and Sanitation: Hot Water Supply, Warming and Ventilation=, Steam Cooking, Gas, Electric Light, Bells, etc., with a complete Schedule of Prices of Plumber's Work. By G.B. DAVIS and F. DYE. 2 vols. 637 illus. and 21 folding plates, 830 pp. 4to, cloth. (_1899_) _net_ 1 10 0 =Standard Practical Plumbing.= By P.J. DAVIES. Vol. I. Fourth edition, 768 illus. 355 pp. royal 8vo. (_1905_) _net_ 7 6 Vol. II. Second edition, 953 illus. 805 pp. (_1905_) _net_ 10 6 Vol. III. 313 illus. 204 pp. (_1905_) _net_ 5 0 =Conservancy, or Dry Sanitation versus Water Carriage.= By J. DONKIN. 7 plates, 33 pp. 8vo, sewed. (_1906_) _net_ 1 0 =Sewage Disposal Works=, their Design and Construction. By W.C. EASDALE. With 160 illus. 264 pp. demy 8vo. (_1910_) _net_ 10 6 =House Drainage and Sanitary Plumbing.= By W.P. GERHARD. Tenth edition, 6 illus. 231 pp. 18mo, boards. (_New York, 1902_) _net_ 2 0 =Engineering Work in Towns and Cities.= By E. MCCULLOCH. 44 illus. 502 pp. crown 8vo. (_New York, 1908_) _net_ 12 6 =The Treatment of Septic Sewage.= By G.W. RAFTER. 137 pp. 18mo, boards. (_New York, 1904_) _net_ 2 0 =Reports and Investigations on Sewer Air= and Sewer Ventilation. By R.H. REEVES. 8vo, sewed. (_1894_) 1 0 =The Law and Practice of Paving= Private Street Works. By W. SPINKS. Fourth edition, 256 pp. 8vo. (_1904_) _net_ 12 6 STRUCTURAL DESIGN. (_See_ BRIDGES AND ROOFS.) TELEGRAPH CODES. =New Business Code.= 320 pp. narrow 8vo. (Size 4¾ in. by 7¾ in. and ½ in. thick, and weight 10 oz.) (_New York, 1909_) _net_ 1 10 0 =Miners' and Smelters' Code= (formerly issued as the =Master Telegraph Code=). 448 pp. 8vo, limp leather, weight 14 oz. (_New York, 1899_) _net_ 2 10 0 =Billionaire Phrase Code=, containing over two million sentences coded in single words. 56 pp. 8vo, leather. (_New York, 1908_) _net_ 6 6 WARMING AND VENTILATION. =Hot Water Supply.= By F. DYE. Fifth edition, 48 illus. 86 pp. crown 8vo. (_1902_) _net_ 3 0 =A Practical Treatise upon Steam Heating.= By F. DYE. 129 illus. 246 pp. demy 8vo. (_1901_) _net_ 10 0 =Practical Treatise on Warming Buildings by Hot Water.= By F. DYE. 192 illus. 319 pp. 8vo. cloth. (_1905_) _net_ 8 6 =Charts for Low Pressure Steam Heating.= By J.H. KINEALY. Small folio. (_New York_) 4 6 =Formulæ and Tables for Heating.= By J.H. KINEALY. 18 illus. 53 pp. 8vo. (_New York, 1899_) 3 6 =Mechanics of Ventilation.= By G.W. RAFTER. Second edition, 18mo, boards. (_New York, 1896_) _net_ 2 0 =Principles of Heating.= By W.G. SNOW. 62 illus. 161 pp. 8vo. (_New York, 1907_) _net_ 8 6 =Furnace Heating.= By W.G. SNOW. Fourth edition, 52 illus. 216 pp. 8vo. (_New York, 1909_) _net_ 6 6 =Ventilation of Buildings.= By W.G. SNOW and T. NOLAN. 83 pp. 18mo, boards. (_New York, 1906_) _net_ 2 0 =Heating Engineers' Quantities.= By W.L. WHITE and G.M. WHITE. 4 plates, 33 pp. folio. (_1910_) _net_ 10 6 WATER SUPPLY. (_See also_ HYDRAULICS.) =Potable Water and Methods of Testing Impurities.= By M.N. BAKER. 97 pp. 18mo, boards. (_New York, 1905_) _net_ 2 0 =Manual of Hydrology.= By N. BEARDMORE. New impression, 18 plates, 384 pp. 8vo. (_1906_) _net_ 10 6 =Boiler Waters=, Scale, Corrosion and Fouling. By W.W. CHRISTIE. 77 illus. 235 pp. 8vo, cloth. (_New York, 1907_) _net_ 12 6 =Water Softening and Purification.= By H. COLLET. Second edition, 6 illus. 170 pp. crown 8vo. (_1908_) _net_ 5 0 =Treatise on Water Supply=, Drainage and Sanitary Appliances of Residences. By F. COLYER. 100 pp. crown 8vo. (_1899_) _net_ 1 6 =Report on the Investigations into the Purification of the Ohio River Water= at Louisville, Kentucky. By G.W. FULLER. 8 plates, 4to, cloth. (_New York, 1898_) _net_ 2 2 0 =Purification of Public Water Supplies.= By J.W. HILL. 314 pp. 8vo. (_New York, 1898_) 10 6 =Well Boring for Water, Brine and Oil.= By C. ISLER. _New edition in the Press._ =Method of Measuring Liquids Flowing through Pipes by means of Meters of Small Calibre.= By Prof. G. LANGE. 1 plate, 16 pp. 8vo, sewed _net_ 0 6 =On Artificial Underground Water.= By G. RICHERT. 16 illus. 33 pp. 8vo, sewed. (_1900_) _net_ 1 6 =Notes on Water Supply= in new Countries. By F.W. STONE. 18 plates, 42 pp. crown 8vo. (_1888_) 5 0 =The Principles of Waterworks Engineering.= By J.H.T. TUDSBERY and A.W. BRIGHTMORE. Third edition, 13 folding plates, 130 illus. 447 pp. demy 8vo. (_1905_) _net_ 1 1 0 WORKSHOP PRACTICE. =A Handbook for Apprenticed Machinists.= By O.J. BEALE. Second edition, 89 illus., 141 pp. 16mo. (_New York, 1901_) _net_ 2 6 =Bicycle Repairing.= By S.D.V. BURR. Sixth edition, 200 illus. 208 pp. 8vo. (_New York, 1903_) _net_ 4 6 =Practice of Hand Turning.= By F. CAMPIN. Third edition, 99 illus. 307 pp. crown 8vo. (_1883_) 3 6 =Calculation of Change Wheels for Screw Cutting on Lathes.= By D. DE VRIES. 46 illus. 83 pp. 8vo. (_1908_) _net_ 3 0 =Milling Machines and Milling Practice.= By D. DE VRIES. With 536 illus. 464 pp. medium 8vo. (_1910_) _net_ 14 0 =French-Polishers' Manual.= By a French-Polisher. 31 pp. royal 32mo, sewed. (_1902_) _net_ 0 6 =Art of Copper Smithing.= By J. FULLER. Third edition, 475 illus. 325 pp. royal 8vo. (_New York, 1901_) _net_ 12 6 =Saw Filing and Management of Saws.= By R. GRIMSHAW. New edition, 81 illus. 16mo. (_New York, 1906_) _net_ 3 6 =Paint and Colour Mixing.= By A.S. JENNINGS. Fourth edition. 14 coloured plates, 190 pp. 8vo. (_1910_) _net_ 5 0 =The Mechanician=: a Treatise on the Construction and Manipulation of Tools. By C. KNIGHT. Fifth edition, 96 plates, 397 pp. 4to. (_1897_) 18 0 =Turner's and Fitter's Pocket Book.= By J. LA NICCA. 18mo, sewed 0 6 =Tables for Engineers and Mechanics=, giving the values of the different trains of wheels required to produce Screws of any pitch. By LORD LINDSAY. Second edition, royal 8vo, oblong 2 0 =Screw-cutting Tables.= By W.A. 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Sixth edition, 85 illus. 319 pp. royal 32mo, roan, gilt edges. (_1909_) _net_ 5 0 =Power and its Transmission.= A Practical Handbook for the Factory and Works Manager. By T.A. SMITH. 76 pp. fcap. 8vo. (_1910_) _net_ 2 0 =Spons' Mechanics' Own Book=: A Manual for Handicraftsmen and Amateurs. Sixth edition, 1430 illus. 720 pp. demy 8vo. (_1903_) 6 0 Ditto ditto half morocco 7 6 =Spons' Workshop Receipts for Manufacturers, Mechanics and Scientific Amateurs.= New and thoroughly revised edition, crown 8vo. (_1909_) _each net_ 3 0 Vol. I. ACETYLENE LIGHTING _to_ DRYING. 223 illus. 532 pp. Vol. II. DYEING _to_ JAPANNING. 259 illus. 540 pp. Vol. III. JOINTING PIPES _to_ PUMPS. 256 illus. 528 pp. Vol. IV. RAINWATER SEPARATORS _to_ WINES. 250 illus. 520 pp. =Gauges at a Glance.= By T. TAYLOR. Second edition, post 8vo, oblong, with tape converter. (_1900_) _net_ 5 0 =Simple Soldering=, both Hard and Soft. By E. THATCHER. 52 illus. 76 pp. crown 8vo, limp. (S. & C. SERIES, NO. 18.) (_New York, 1910_) _net_ 1 6 =The Modern Machinist.= By J.T. USHER. Fifth edition. 257 illus. 322 pp. 8vo. (_New York, 1904_) _net_ 10 6 =Practical Wood Carving.= By C.J. WOODSEND. 108 illus. 86 pp. 8vo. (_New York, 1897_) _net_ 4 6 =American Tool Making= and Interchangeable Manufacturing. By J.W. WOODWORTH. 600 illus. 544 pp. demy 8vo. (_New York, 1905_) _net_ 17 0 USEFUL TABLES. =Weights and Measurements of Sheet Lead.= By J. ALEXANDER. 32mo, roan _net_ 1 6 =Tables of Parabolic Curves= for the use of Railway Engineers and others. By G.T. ALLEN. Fcap. 16mo 4 0 =Barlow's Tables of Squares=, Cubes, Square Roots, Cube Roots and Reciprocals. Crown 8vo 6 0 =Tables of Squares.= By E.E. BUCHANAN. Ninth edition, 12mo _net_ 4 6 =Land Area Tables.= By W. CODD. Square 16mo, on a sheet mounted on linen and bound in cloth 3 6 =Tables for Setting out Curves= from 101 to 5000 feet radius. By H.A. CUTLER and F.J. EDGE. Royal 32mo _net_ 2 6 =Transition Curves.= By W.G. FOX. 18mo, boards. 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SPON & CHAMBERLAIN PUBLISHERS OF TECHNICAL BOOKS 123-5 Liberty Street,--New York [Illustration] The Percy Pierce Flyer A FAMOUS PRIZE WINNER A Large Scale Drawing of this famous model, with all measurements and details showing a front elevation, a side elevation and a top plan, with full descriptive matter. Anybody can make an =EXACT DUPLICATE= of this Prize Winner for himself at small cost. DO IT NOW Complete set of materials in the rough with drawing and instructions, Postpaid, $1.15 The drawing and instructions 15c postpaid Make Your Own GLIDER How to make a 20 ft. Biplane Gliding Machine That will carry an ordinary man PracticaI handbook on the construction of a Biplane Gliding Machine enabling an intelligent reader to make his first step in the field of aviation with a comprehensive understanding of some of the principals involved. By Alfred Powell Morgan. Contents of Chapters: 1. The Framework, Assembling and finishing the wood. 2. 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A set of 5 full-size scale drawings for three different models with descriptive illustrated book explaining how to make and fly them. Postpaid : : : : 55c =No. 2 Model.= Complete set of parts in the rough to make up this model. (Without drawings), Postpaid : : 65c [Illustration: No. 3 Model] =No. 3 Model.= Complete set of parts in the rough (without drawings). This makes up into a beautiful little model. Postpaid : : : : $1.15 =Model Gliders, Birds, Butterflies and Aeroplanes.= How to make and fly them, by E.W. Twining. Consisting of one large sheet of 12 butterflies and two birds printed in bright colors. One small cardboard Model Glider with descriptive illustrated book showing how to make and fly them. Postpaid : : : : 55c * * * * * Transcriber's Notes Obvious punctuation and spelling errors and inconsistent hyphenation have been corrected. Italic text is denoted by _underscores_ and bold text by =equal signs=. The OE ligature has been replaced by the separate characters. The fractions ¼, ½ and ¾ are represented using the Latin-1 characters, but other fractions use the / and - symbols, e.g. 3/8 or 2-5/8. The exponents 2 and 3 are represented using ² and ³ respectively, but other exponents are indicated by the caret character, for example, v^{1·85} Subscripts are simply enclosed in braces, e.g. W{0}. Other symbols that cannot be represented have been replaced by words in braces: {alpha}, {pi}, {therefore}, {square root} and {proportional to}. The skin friction formulæ given on pages 11 and 128 have been corrected by comparison with other sources. Respectively, the formulæ were originally printed as _f_ = 0·00000778_l_^{9·3}_v_^{1·85} and _f_ = 0·00000778_l_ - ^{00·7}_v_^{1·85} In ambiguous cases, the text has been left as it appears in the original book. 
41891	----	AUTOMOBILE BIOGRAPHIES An Account of the Lives and the Work of Those Who Have Been Identified with the Invention and Development of Self-Propelled Vehicles on the Common Roads Illustrated New York The Monograph Press Copyright, 1904 by the Monograph Press All Rights Reserved FOREWORD In a large sense the history of the rise of the automobile has been a history of some of the foremost inventors, mechanical engineers, manufacturers and active business men of more than a full century. The subject of self-propelled vehicles on the common roads has enlisted the faculties of many men whose minds have been engrossed with the study and the solution of mechanical and engineering problems, purely from an absorbing love of science; it has had the financial support of those whose energies are constantly and forcefully exerted in the industrial and commercial activities of the age; it has received the merited consideration of those who regard as of paramount importance any addition to the sum of successful human endeavor and any influence that contributes to the further advance of modern civilization. Along these lines of thought this book of AUTOMOBILE BIOGRAPHIES has been prepared. On its pages are sketches of the lives and the work of those who have been most active in planning, inventing and perfecting the modern horseless highway vehicle, in adapting it to the public needs for pleasure or business and in promoting its usefulness and broadening the field of its utility. Included herein are accounts of the pioneer inventors, the noted investigators and the contemporaneous workers who have helped to make the automobile in its many forms the most remarkable mechanical success of to-day and the most valuable and epoch-making addition to the conveniences of modern social, industrial and commercial life. These sketches have been carefully prepared from the best sources of information, works of reference, personal papers and so on, and are believed to be thoroughly accurate and reliable. Much of the information contained in them has been derived from exceedingly rare old volumes and papers that are not generally accessible, and it comes with a full flavor of newness. Much also has been acquired from original sources and has never before been given to the public. The investigator into this subject will find, doubtless, to his very great surprise, that the story of the pioneer inventors, who, in the early part of the nineteenth century, experimented with the problems of the steam road carriage, has been recorded voluminously and with much detail. It was a notable movement, that absorbed the abundant attention of inventors, manufacturers and the public at large at that time. Writers of that day recorded with a great deal of particularity the experimenting with boilers, engines, machinery and carriages, and the promoting of companies for the transportation of passengers and the hauling of goods. Modern students and historians of this subject find themselves greatly indebted to the writers of that epoch, like Gordon, Herbert and others, who preserved, with such painstaking care, for future generations, as well as for their own time, the account of the lives and labors of such men as Watt, Trevithick, Maceroni, Hancock and others. Every modern work upon this subject draws generously from those sources. Concerning the later period from the middle of the century that has just ended, down to the present time, there is less concrete information, readily available. With the cessation of public interest in the matter and its general relegation into the background, by inventors, engineers and those who had previously been financial backers of the experimenting, writers ceased to give the subject the enthusiastic attention that they had before bestowed upon it. Records of that period are scant, partly because there was so little to record and partly because no one cared to record even that little. Until comparatively recent times the historian of the self-propelled vehicle, who was so much in evidence seventy-five years ago, had not reappeared. Even now his work is generally of a desultory character, voluminous, but largely ephemeral. It is widely scattered, not easily accessible and already considerably forgotten from day to day. Especially of the men of the last half century, who have made the present-day automobile possible and are now contributing to its greater future, the following pages present much that has never been brought together in this form. It is both history and the material for history. It is believed that these sketches will be found peculiarly interesting and permanently valuable. Individually they are clear presentations of the achievements of some of the most distinguished engineers and inventors of the last hundred years. Collectively they present a complete story of the inception and gradual development of the automobile from the first clumsy steam wagons of Cugnot, Trevithick, Evans and others to the perfected carriage of to-day. The chapter on The Origin and Development of the Automobile is a careful study and review of the conditions that attended the attempts to install the first common road steam carriages, the tentative experimenting with bicycles, tricycles and other vehicles in the middle of the last century and the renaissance of the last two decades. Several of the illustrations are from old and rare prints, and others are from photographs. It is not possible to set down here all the authorities that have been consulted in the preparation of this work. Special acknowledgment, however, must be made to The Engineering Magazine for permission to use text and photographs, and to J. G. Pangborn for permission to use a great deal of interesting information regarding the early steam inventors contained in his work, The World's Railway, and to reproduce portrait sketches of Trevithick, Murdoch, and Read, from the same valuable volume. LYMAN HORACE WEEKS. NEW YORK, January, 1905. ORIGIN AND DEVELOPMENT OF THE AUTOMOBILE STRANGE EARLY VEHICLES He who would fully acquaint himself with the history of the inception and growth of the idea of travel by self-propelled vehicles on the public highways must go further back in the annals of the past than he is likely first to anticipate. Nearly three centuries ago men of mechanical and scientific turns of mind were giving attention to the subject, although their thoughts at that time were mostly confined to the realms of imaginative speculation. Even before that philosophers occasionally dreamed of what might be in some far off time. Roger Bacon, in the thirteenth century, looking into the distant future, made this prediction: "It will be possible to construct chariots so that without animals they may be moved with incalculable speed." It was several hundred years before men were ready to give practical attention to this idea, and about 1740 good Bishop Berkeley could only make this as a prediction and not a realization: "Mark me, ere long we shall see a pan of coals brought to use in place of a feed of oats." But the ancients, in a way, anticipated even Roger Bacon and Bishop Berkeley, for Heliodorus refers to a triumphal chariot at Athens that was moved by slaves who worked the machinery, and Pancirollus also alludes to such chariots. HORSELESS WAGONS IN CHINA Approaching the seventeenth century the investigator finds that definite examples are becoming more numerous, even if as yet not very practical. China, which, like Egypt, seems to have known and buried many ideas centuries before the rest of the world achieved them, had horseless vehicles before 1600. These merit, at least, passing attention even though they were not propelled by an engine, for the present automobile is the outgrowth of that old idea to eliminate the horse as the means of travel. Matthieu Ricci, 1552-1610, a Jesuit missionary in China, told how in that country a wagon not drawn by horses or other animals was in common use. In an early collection of travels this vehicle was described as follows: "This river is so cloyed with ships because it is not frozen in winter that the way is stopped with multitude; which made Ricius exchange his way by water into another (more strange to us) by waggon, if we may so call it, which had but one wheel, so built that one might sit in the middle as 'twere on horseback, and on each side another, the waggoner putting 't swiftly and safely forwards with levers or barres of wood (those waggons driven by wind and gayle he mentions not.)" It was somewhat later than this that China was indebted to that other famous Jesuit missionary, Verbiest, for his steam carriage, which, however, was not much more than a toy. MANUALLY PROPELLED VEHICLES But in the seventeenth century most attention seems to have been given to devising carriages that should be moved by the hand or foot power of man. The auto car that was run in the streets of Nuremberg, Germany, by Johann Hautsch, in 1649, was of this description, and that of Elié Richard, the physician, of La Rochelle, France, about the same time, was of the same class. Not long after this Potter, of England, came along in 1663 with a mechanical cart designed to travel on legs, and in the same year the celebrated Hooke presented to the Royal Society of England a plan for some sort of a machine by which one could "walk upon the land or water with swiftness, after the manner of a crane." It does not quite appear what that cart and that machine were. One authority thinks that the Hooke patent was for a one-wheel vehicle supposed to be propelled by a person inside the wheel. Then, also, there was Beza, another French physician, with a mechanical vehicle in 1710. OTHER FRENCH AND ENGLISH EXPERIMENTS In fact, the interest in carriages worked by man power extended from the seventeenth well into the nineteenth century. Soon after the time of Beza, mechanical chariots, modeled after the Richard coach, were advertised to be run in London, but it does not appear that they met with public favor. Scientists and others gave much thought to the subject, both in England and in France. John Vevers, master of the boarding-school at Ryegate, Surrey, came out with a carriage that was evidently copied from that of Richard. Other forms of carriages worked by hand or foot power of man were described in the periodicals of the time. George Black, of Berwick-on-the-Tweed, built a wagon to be run by hand power in 1768. In England, John Ladd, of Trowbridge, Wilts, in 1757; John Beaumont, of Ayrshire, in 1788, and in France, Thomas in 1703, Gerard in 1711, Ferry in 1770, and Maillard, Blanchard and Meurice, in 1779, and others, were most active during this period. It was well into the nineteenth century before this idea was wholly abandoned. Edmund Cartwright, inventor of the hand loom, contributed to the experimenting, and the 1831 patent to Sir James C. Anderson was for a very imposing vehicle rowed by twenty-four men. COMPRESSED AIR POWER At the same time that the steam engineers in England were bringing out their vehicles, 1800-35, others were at work on the problem of compressed air carriages. Among these was W. Mann, of Brixton, who, in 1830, published in London a pamphlet, entitled A Description of a New Method of Propelling Locomotive Machines, and of Communicating Power and Motion to All Other Kinds of Machinery, and it contained a lithograph of the proposed carriage. Sir George Medhurst, of England, about 1800, with his proposed regular line of coaches run by compressed air was, perhaps, the most conspicuous experimenter into this method of propulsion. SAILING CARRIAGES ON LAND Many men long speculated upon the possibility of wind propulsion on land as well as upon the sea. The most ambitious attempt in that line was the sailing chariot of Simon Stevin, of The Hague, in 1600. Vehicles of this kind were built by others, and in 1695 Sir Humphrey Mackworth applied sails to wagons on the tramways at his colliery at Neath, South Wales. The Frenchman, Du Quet, in 1714, and the Swiss clergyman, Genevois, proposed to get power from windmills mounted on their wagons. More curious even than these was the carriage drawn by kites, the invention of George Pocock, in 1826. THE STEAM CARRIAGE PREDICTED But all these and other fantastic devices never got beyond the experimental stage, and nothing of a substantial, practical character was ever evolved from them. It remained for the latter part of the eighteenth century to see the subject taken up seriously and considered in a way that promised definite results. And it was steam that then brought the matter strongly to the front. It is true that Sir Isaac Newton tentatively suggested the possibility of carriage propulsion by steam about 1680, but his suggestion lay dormant for nearly a century. Then the growing knowledge of the power of steam and the possibilities in the new element turned men's thoughts again very forcibly to this theme. The stationary engine had shown its usefulness, and the consideration of making this stationary machine movable, and therefore available for transportation, naturally followed. Dr. Erasmus Darwin is said to have urged James Watt and Matthew Boulton to build a fiery chariot as early as 1765. In his poem, The Botanic Garden, famous in that day, Dr. Darwin, like a prophet crying in the wilderness, sang of the future of steam in these lines: "Soon shall thy arm, unconquered steam, afar Drag the slow barge, or drive the rapid car; On, on wide waving wings, expanded bear The flying chariot through the field of air; Fair crews triumphant, leaning from above, Shall wave their fluttering 'kerchiefs as they move, Or warrior bands alarm the gaping crowds, And armies shrink beneath the shadowy clouds." These lines may indeed be fairly interpreted as anticipating in prophetic prediction the modern motor airship, as well as the motor car. THE FIRST STEAM VEHICLES It was considerably later than this that the dream of Dr. Darwin approached to realization at the hands of the steam engine inventors and builders. Aside from Nicholas Joseph Cugnot, the French army officer who, about 1769, constructed an artillery wagon propelled by a high-pressure engine, those who first built successful self-propelled vehicles for highway travel were the famous engineers of England and Scotland, who harnessed steam and developed the high-pressure engine in the last half of the eighteenth century and the first half of the nineteenth. James Watt patented, in 1782, a double-acting engine, which he planned might be "applied to give motion to wheel carriages," the engine to be portable; but he never put the patent to trial. He was followed by George Stephenson, Richard Trevithick, Walter Hancock, Goldsworthy Gurney, David Gordon, William Brunton and others in England, and Oliver Evans, Nathan Read and Thomas Blanchard in the United States, with two score or more contemporaries. For more than half a century steam vehicles of various types were invented by these engineers and many of them were brought into practical use. Soon after the end of the first quarter of the nineteenth century the interest in steam carriages had assumed large proportions in England. In 1833 there were no less than twenty such vehicles, either completed or in hand, around London, and a dozen corporations had been organized to build and run them over stated routes. Alexander Gordon, the eminent engineer, wrote a book, entitled Treatise Upon Elemental Locomotion, that went into three editions inside of four years. He also brought out two special journals covering this field of mechanics. The Mechanic's Magazine, and other publications, also gave much attention to the subject, and the steam-carriage literature of the period became very voluminous. POPULAR PREJUDICE AROUSED For a time it looked as though the new vehicle was destined to a permanency and to accomplish a revolution in the methods of travel on the high-roads. But several things arose to determine otherwise. There sprang up an unreasoning senseless hostility to any substitute for the horse as the agent of vehicular traffic. The stage-coach drivers were afraid that they would be thrown out of work. Breeders of horses foresaw the destruction of their business, when horses should no longer be in demand. Farmers were sure that with horses superseded by steam, they would never be able to sell any more oats. This public animosity manifested itself wherever the steam carriages went. The coaches were hooted at and stoned amid cries of "down with machinery." Stones and other obstacles were placed in the roads, trenches were dug to trap the unsuspicious driver and stretches of roadway were dug up and made into quagmires to stall the machines. Parliament was called upon and enacted excessive highway tolls, especially directed at steam carriages. Another law that stood on the statute books of Great Britain until within comparatively recent times compelled every self-propelled vehicle moving on the highway to be preceded by a man walking and carrying a red flag. THE BEGINNING OF RAILROADS All this was undoubtedly due, in a large measure, if not wholly, to what was then known as the Turn Pike Trusts, which, in conjunction with the stage-line companies, in many cases, were owners of a thousand and more horses. The latter, quite naturally, objected to the introduction of the mechanical vehicle, while the former had such relations to them that both their interests were identical. But above all things, the great art of railroading had already grown from infant existence to a condition of great possibilities, which were now to be finally determined by a success, not alone mechanical and in the eyes of the inventor, but measured by the balance sheets of the companies of individuals who had made possible the construction of the various experimental locomotives or experimental lines then being operated in England and elsewhere. Just at this time, in the thirties of the nineteenth century, seems to have been the crucial point. The arguments of the engineers on the question of sufficient traction of the iron-shod wheels on iron or other hard railways, while given due consideration, were not wholly convincing, at least to the people investing their money in the enterprises; the profits were to tell in the final conclusion, and it would seem that the great era of railroading might be considered to have had its actual birth at this time, because: The first dividend was paid on one of the great railroad enterprises. INFLUENCE OF THE FIRST DIVIDEND For the time being that seemed to sound the death knell of the common road steam-propelled vehicle. The engineers so strongly advocating the railroad had proven their various propositions in the eyes of those who had the financial powers to engage in the extensive introduction and development of the new means of transportation. Further demonstration, extensively exploited, was also made to the satisfaction of those investors, that vehicles could be pulled with less power on a hard roadbed such as a railway, than on an uneven and sometimes soft path such as common roads. It seems clear that these and various other arguments, heartily urged at that time, and, in some cases, unquestionable from a technical standpoint, were really decided by that first dividend. And the common road vehicle with the support and enthusiasm of its backers largely withdrawn from it dropped to a position greatly subordinate to the other branch of transportation. THE STEAM ROAD VEHICLE AGAIN On the other hand, the development which came in the next few decades in the railroad department brought also a renewed demand for common road vehicles for certain classes of work or for certain localities. The steam vehicle for stationary purposes, and also for the locomotive, were being rapidly developed and refined. The railroad settled down to the idea of a power unit drawing numerous wagons. That has been consistently adhered to to the present day, and only in the past decade have we gone back to the old and first principles of embodying the mechanical propelling means in the same vehicle that transports the passengers or goods. So, while Hancock and his worthy contemporaries passed into history, other common road steam advocates continued their isolated attempts up to and past the middle of the nineteenth century, although without any such general enthusiasm as prevailed in the twenties and early thirties. NEW GENERATION OF INVENTORS Many attempts in America, such as those of Fisher, Dudgeon, and others, and the work in England by numerous inventors and machine manufacturers, such as Tangye, Hilditch, Snowden, F. Hill, Jr., aided by the engineers, Macadam, Telford and M'Neil, who were improving the common roads so that they might approach the advantageous conditions of the railroad, assume prominence in connection with that period of the history. Rickett's carriage, in 1858; Carrett's, in 1862; Boulton's, in 1867; Catley's, in 1869, and others, were among the finger-posts of that time, pointing to more notable achievements of the future. But in England the Act of Parliament, passed in 1836 and in force almost to to-day, known as the Locomotive Act, was the deterrent to progress in common road steam locomotion. This condition even continued after the select committee of Parliament, in 1873, endeavored to remove some of the restrictions, but succeeded only in producing the Act of 1878, which in no way improved the position of the common road vehicle. In France and on the Continent political conditions doubtless mitigated against any general advance, and though this period included the great development of machinery and construction which paved the way for the future, it is not of prominence in this history. A PERIOD OF EXPERIMENTING A new era may be said to have commenced in the early part of the seventies when we find Amédèe Bollèe exhibiting a steam machine at the Vienna Exposition. In the seventies were also experiments on modified forms of power on vehicle propelling motors other than steam, but it still seemed to be the steam vehicle that characterized the new period of activity which blossomed out in the early eighties with many ardent advocates, and exhibited a type of light vehicle with efficient strong boiler and light engine. America should not be overlooked, however, when we consider the one small vehicle of Austin, which was constructed in Massachusetts, and attracted great attention at the shows of the Ocean Circus, in the early seventies, or thereabout. Bouton, of France, came to the fore in the early eighties, and the light steam vehicle seemed on the high road to a great development and a monopoly of the common roads vehicle industry, until its competitor appeared in what is now popularly known as the gasoline vehicle in the middle eighties. THE SELDEN PATENT From this time on the great industry of to-day advanced in strides and jumps, but while the future had been anticipated in some suggestions and experiments in Europe, at last one great mind had delved into the problem and anticipated the great future of the new type of vehicle in America. Selden, after a decade or more of study and work, and well-directed experiments, had made his own deductions, and with clear discerning had concluded what, to his mind, would be _the_ vehicle in the future. The result of his labors and the subsequent filing, in 1879, of a patent application, when considered in connection with his persistent work from that time on, even to the present day, would seem to justly mark him as the pioneer in this type of vehicle; in fact, he was so called by the Commissioner of Patents of the United States when publishing his annual report, immediately after the issue of Selden's patent. ADVENT OF THE HYDRO-CARBON ENGINE Then followed the work on carbureters and ignition devices and details of construction adapting the liquid hydro-carbons of uncertain quality to more satisfactory use. Details became and still are numerous, and optional to a great extent, but the liquid hydro-carbon engine of the compression type distinguished the new epoch. The development of the stationary engine operated with gas from receivers also proceeded rapidly in those days, though it was well into the eighties before the gas engine of the compression type involved a commercially successful industry to any extent; not for several years did the principal manufacturers take up commercially the proposition of the liquid hydrocarbon application. The development of the small engine using liquid hydro-carbons received attention from Marcus, in Austria, and the persistent attention of Benz and of Daimler, in Germany. The two latter, furthermore, adapted their engines to vehicles, and enthusiasm was great when Benz ran his three-wheeler, with explosive engine, through the streets of his native town. PROGRESS IN FRANCE AND AMERICA England was still shackled; but in France many were inspired to change from steam to the hydro-carbon engine. About 1890 we find several French manufacturers procuring engines, or the right to manufacture the small explosive engines developed by the Germans, and promptly adapting them to their vehicle construction, already well developed for steam propulsion. Panhard & Levassor; Bouton, with his backer, DeDion; Bollèe, now Leon, the nephew; Delahaye and Peugeot, were among the earliest Frenchmen to appreciate the commercial possibilities of the new type. Then the large manufacturers, already experienced in other lines, and particularly in cycle manufacture, entered the field in 1893, 1894 and 1895; among them such old concerns as DeDetrich, manufacturers for one hundred and more years, grasped the opportunity. America was not idle, and while road conditions in this country militated largely against the early attempts in the industry, the efforts of the Duryeas and of Haynes, and various other experimenters, who have since retired, were heard from. It was difficult, however, with the obstacles then existing in America, for these early workers to secure encouragement, and progress was slow, just as the endeavors of Selden and some of the early steam vehicle people had received nothing but discouragement at the hands of those whom they endeavored to lead to the success of large manufacturing undertakings. However, the Times-Herald race, in Chicago, near the close of 1895, brought forth a large number of inventors and several starters, including electric, steam and gasoline vehicles, and the showing was such as to practically satisfy the doubting that these were the beginning of the industry in this country. THE ENGLISH REVIVAL Abroad, the leaders in the automobile movement organized the now historic races from Paris in different directions. With the runs of 1894, 1895 and 1896, and in each successive year thereafter, and with the road and other conditions improved, the industry rapidly developed. England also was at last reached. The restraints that had existed there for more than half a century could no more be endured. The burden was finally thrown off, for which great credit is due to Sir David Salomon, and the offensive Locomotive Act was at last repealed in August, 1896. The subsequent Locomotive Act which came into effect November 14, 1896, marked a red-letter day in motoring history for England, and was justly celebrated by a procession of vehicles from London to Brighton. Salomon had previously organized an exhibition in England, and had imported a French car, and as a prominent member of scientific and technical societies, in which he presented many papers on the subject, had done, possibly, more than any other individual to influence public sentiment and to secure this new enactment. English manufacturers were not entirely unprepared for the change, and a great wave of interest and activity swept the country. Naturally this was followed by a reaction, but since then a counter-reaction has set in, resulting in the present grand development of that class of manufacturing in the British Isles. The small steam vehicle of Whitney, and his contemporaries, the Stanleys in the United States, then came to the fore. Under energetic promotion thousands of small vehicles of that type were manufactured and put into use. These, in no small measure, became to the public at large the convincing object lesson of the practicability and possibilities of the small automobile for every-day use. MODERN CONDITIONS The Paris show of 1900 revealed a great forward step in the development of constructions, and the offer immediately thereafter of the James Gordon Bennett trophy of international racing gave to the automobile industry such an impetus as has seldom been the good fortune of any other art to receive. To-day the automobile has reached that stage of perfection where the question is no longer whether or not the vehicle will carry you to a certain place and back. Now it is only a question of the speed, absence of vibration, and sweetness of running the engine, absence of all noise, and other details of refinement. Vehicles are now of the Pullman type, luxurious to the extent of prices ranging into the thirties of thousands of dollars, while on the other hand, thousands of small vehicles, costing between five hundred and one thousand dollars, are annually made and sold. The steam machine, after being practically succeeded by the gasoline, was again improved by the flash boiler. The main development of this new power was carried on by Serpollet, of France, and later, by Rollin T. White, in the United States, both whom have become most able competitors of manufacturers of machines of other classes. THE INDUSTRY TO-DAY The beginning of 1905 finds us with the annual shows, which have been consecutive for many years, while the census of vehicles now in use, or made in the last ten years, will aggregate several hundred thousand. The annual production is estimated as probably approximating one hundred thousand in a few of the principal countries. The value of the electrical vehicle, particularly as the town vehicle for anything except speeding, is now well established, and reports from Paris as well as New York indicate the lack of facilities of factories in this line for producing these carriages as rapidly as demanded. Heavy 'buses and individual vehicles alike are also popular. PIONEER INVENTORS NICHOLAS JOSEPH CUGNOT, WILLIAM MURDOCK, OLIVER EVANS, WILLIAM SYMINGTON, NATHAN READ, RICHARD TREVITHICK, DAVID GORDON, W. H. JAMES, GOLDSWORTHY GURNEY, THOMAS BLANCHARD, M. JOHNSON, WALTER HANCOCK, W. T. JAMES, FRANCIS MACERONI, RICHARD ROBERTS, J. SCOTT RUSSELL, W. H. CHURCH, ETIENNE LENOIR, AMÉDÈE BOLLÈE, GEORGE B. SELDEN, SIEGFRIED MARCUS, CARL BENZ, GOTTLIEB DAIMLER, M. LEVASSOR, LEON SERPOLLET. NICHOLAS JOSEPH CUGNOT Born at Void, Lorraine, France, September 25, 1725. Died in Paris, October 2, 1804. Concerning the early life of Cugnot, little is known. He was educated for the engineering service of the French army, and gained distinction as a military and mechanical engineer. He also served as a military engineer in Germany. Soon afterward he entered the service of Prince Charles of Lorraine, and for a time resided at Brussels, where he gave lessons in the military art. He did not return to his native land until 1763, and then invented a new gun, with which the cavalry were equipped. This brought him to the attention of the Compte de Saxe, and under the patronage of that nobleman, he constructed in 1765 his first locomotive. This was a small wagon. On its first run it carried four persons, and traveled at the rate of two and a quarter miles an hour. The boiler, however, being too small, the carriage could go only for fifteen or twenty minutes before the steam was exhausted, and it was necessary to stop the engine for nearly the same time, to enable the boiler to raise the steam to the maximum pressure, before it could proceed on its journey. This machine was a disappointment, in consequence of the inefficiency of the feed pumps. It has been stated that while in Brussels he had made a smaller vehicle, which, if so, was soon after 1760. Several small accidents happened during the trial, for the machine could not be completely controlled, but it was considered on the whole to be fairly successful and worthy of further attention. The suggestion was made that provided it could be made more powerful, and its mechanism improved, it might be used to drag cannon into the field instead of using horses for that purpose. Consequently, Cugnot was ordered by the Duc de Choiseul, Minister of War, to proceed with the construction of an improved and more powerful machine. This vehicle, which was finished in 1770, cost twenty thousand livres. It was in two parts, a wagon and an engine. The wagon was carried on two wheels and had a seat for the steersman; the engine and boiler were supported on a single driving-wheel in front of the wagon. The two parts were united by a movable pin. A toothed quadrant, fixed on the framing of the fore part, was actuated by spur gearing on the upright steersman's shaft in close proximity to the seat, by means of which the conductor could cause the carriage to turn in either direction, at an angle of from fifteen to twenty degrees. In front was a round copper boiler, having a furnace inside, two small chimneys, two single-acting brass cylinders communicating with the boiler by the steam pipe, and other machinery. On each side of the driving-wheel, ratchet wheels were fixed, and as one of the pistons descended, the piston-rod drew a crank, the pawl of which, working into the ratchet-wheel, caused the driving-wheel to make a quarter of a revolution. By gearing, the same movement placed the piston on the other side in a position for making a stroke, and turned the four-way cock, so as to open the second cylinder to the steam and the first cylinder to the atmosphere. The second piston then descended, causing the leading wheel to make another quarter of a revolution, and restoring the first piston to its original position. In order to run the vehicle backwards, the pawl was made to act on the upper side, changing the position of the spring which pressed upon it; then, when the engine was started, the pawl caused the driving-wheel to turn a quarter of a revolution in the opposite direction with every stroke of the piston. This machine was first tried in 1770 in the presence of a distinguished assembly, that included the Duc de Choiseul; General Gribeauval, First Inspector-General of Artillery; the Compte de Saxe, and others. Subsequently, other trials of it were made, with satisfactory results generally. The heavy over-balancing weight of the engine and boiler in front rendered it difficult to control. On one of its trips it ran into a wall in turning a corner and was partly wrecked. Further experiments with it were abandoned, and in 1800 it was deposited in the Conservatoire des Arts et Metier, Paris, where it still remains. At a later period of his life, having lost his means of support, Cugnot's public services were considered to entitle him to a reward from the State. Louis Fifteenth gave him a pension of six hundred livres, but the French Revolution coming on, he was deprived even of that pittance, and he lived in abject misery in Brussels. His carriage was then in the arsenal, and a revolutionary committee, during the reign of terror, tried to take it out and reduce it to scrap, but was driven off. When Napoleon came to the throne, he restored the pension and increased it to one thousand livres. In addition to his inventions, Cugnot wrote several works on military art and fortification. WILLIAM MURDOCK Born in Bellow Mill, near Old Cumnock, Ayrshire, Scotland, August 21, 1754. Died at Sycamore Hill, November 15, 1839. Murdock was the son of John Murdoch, a millwright. He was modestly educated, and brought up to his father's trade, helping to build and put up mill machinery. A curious production of the father and son, at this period, was a wooden horse, worked by mechanical power, on which young Murdock traveled about the country. When he was twenty-three years of age he entered the employment of the famous engineering firm of Boulton & Watt, at Soho, and there remained throughout his active life. Watt recognized in him a valuable assistant, and his services were jealously regarded. On his part he devoted himself unreservedly to the interests of his employers. In 1777 he was sent to Cornwall to look after the pumps and engines set up by the firm in the mines, and for a long period he lived at Redruth. For some five years after 1800 he was engineer and superintendent at the Soho foundry. While living at Redruth, in 1792, he began a series of experiments on the illuminating properties of the gases of coal, wood, peat, and other substances, and in 1799 put up a gas-making apparatus at Soho. In 1803 he fitted the Soho factory with a gas-lighting system. Other inventions that are credited to him are models for an oscillating engine and a rotary engine, a method of making steam pipes, an apparatus for utilizing the force of compressed air, and a steam gun. [Illustration: WILLIAM MURDOCK] His early training and all his surroundings naturally and inevitably interested Murdock in the subject of steam locomotion, and before 1784 he began to experiment on these lines. That he made definite progress is shown in a letter that Thomas Wilson, agent in Cornwall of Boulton & Watt, wrote to his employers in August, 1786, saying, "William Murdock desires me to inform you that he has made a small engine of three-quarter-inch diameter and one and one-half inch stroke, that he has applied to a small carriage, which answers amazingly." He had made and run this model in 1784, and it is still in existence, and in the possession of the Messrs. Richard and George Tangye, England. This model was on the high-pressure principle, and ran on three wheels, the single front one for steering. The vertical boiler, nearly over the rear axle, was heated by a spirit-lamp, and the machine stood only a little more than a foot high. The axle was cranked in the middle and turned by a rod connected to a beam moved up and down by the piston-rod projecting from the top of the cylinder. Yet it developed considerable speed. It is interesting to note that the use of the crank for converting the reciprocating motion of the steam engine into rotary was patented by Pickard in 1780, and Murdock's was probably its first application to self-propelled carriages. The first experiment with this little engine was made in Murdock's house at Redruth, when the locomotive successfully hauled a wagon round the room, the single wheel, placed in front of the engine, fixed in such a position as to enable it to run round a circle. Dr. Smiles, in his work on inventors, tells an amusing story concerning this machine. He says: "Another experiment was made out of doors, on which occasion, small though the engine was, it fairly outran the speed of its inventor. One night, after returning from his duties at the mine at Redruth, Murdock went with his model locomotive to the avenue leading to the church, about a mile from the town. The walk was narrow, straight and level. Having lit the lamp, the water soon boiled, and off started the engine with the inventor after it. Shortly after he heard distant shouts of terror. It was too dark to perceive objects, but he found, on following up the machine, that the cries had proceeded from the worthy vicar, who, while going along the walk, had met the hissing and fiery little monster, which he declared he took to be the Evil One in propria persona!" But Murdock was too useful a man to Boulton & Watt to be allowed to have free rein, and his inclination toward steam locomotion invention was apparently curbed, though it would appear Watt thought the roads of that time an insurmountable obstacle to the development of road vehicles, and wanted Murdock to devote his time to mechanical matters more ripe for success. Boulton, writing to Watt from Truro, in September, 1796, tells how he met Murdock on his way to London to get a patent on a new model, and how he persuaded him to turn back. This model was for a steam carriage that was afterward shown as able to travel freely around a room with a light load of shovel, poker and tongs upon it. His was probably the first high-pressure steam-engine vehicle run in England. Though only a small model, it did its proportionate work well. Watt continued to oppose Murdock's scheme, but on one occasion suggested that he should be allowed an advance of five hundred dollars to enable him to prosecute his experiments, and if he succeeded within a year in making an engine capable of drawing a post chaise, carrying two passengers and the driver, at four miles an hour, it was suggested that he should be taken as partner into the locomotive business, for which Boulton and Watt were to provide the necessary capital. This proposition was never carried out. Again, in 1786, Watt said: "I wish William could be brought to do as we do, to mind the business in hand, and let such as Symington and Sadler throw away their time and money in hunting shadows." Murdock continued to speculate about steam locomotion on common roads, but never carried his ideas further. He retired from the employment of Boulton & Watt in 1830, and practically retired from all work at the same time. Murdock seems to have had a very clear idea of the possibilities of steam propulsion on the common roads. Had circumstances permitted he might well have been expected to have solved the problem in 1796 quite as completely as his successors did in 1835. But he was a quarter of a century ahead of the time. Even the moderate public interest that existed later on had not manifested itself at all in his day and the condition of the English highways offered almost insuperable obstacles to steam vehicular travel. Personally his lack of self-assertiveness and his feeling of dependence upon Boulton and Watt also held him back. So he remained simply one of the pioneer investigators pointing the way for others. OLIVER EVANS Born in 1755 or 1756, in Newport, Del. Died in Philadelphia, April 21, 1819. Little has been preserved respecting the early history of Oliver Evans, who has been aptly styled "The Watt of America." His parents were farming people, and he had only an ordinary common-school education. At the age of fourteen he was apprenticed to a wheelwright or wagonmaker, and continued his meager education by studying at night time by the light that he made by burning chips and shavings in the fireplace. While yet an apprentice his attention was turned to the subject of propelling land carriages without animal power. But the lack of definite knowledge in regard to steam power compelled him to abandon his plans, although his experiments were continued for a long time. Soon after attaining his majority he was engaged in making card-teeth by hand, and in connection therewith developed several labor-saving improvements. He also invented improvements in the construction of machinery of flour mills that effected a complete revolution in the manufacture of flour. These improvements consisted of the elevator, the conveyor, the hopper-boy, the drill and the descender, which various machines were applied in different mills so as to perform mechanically every necessary movement of the grain and meal from one part of the mill to the other, causing a saving of fully one-half in the labor of mill attendance and manufacturing the flour better. These improvements were not accepted by the mill owners at the outset, and Evans spent many discouraging years before he could finally persuade the manufacturers of the utility of his inventions. In the end, however, he lived to see his inventions generally introduced, and he profited largely thereby. [Illustration: OLIVER EVANS] In the year 1786, Evans petitioned the Legislature of Pennsylvania for the exclusive right to use his improvements in flour mills and steam carriages in that State, and in the year following presented a similar petition to the Legislature of Maryland. In the former instance he was only successful so far as to obtain the privilege of the mill improvements, his representations concerning steam carriages being considered as savoring too much of insanity to deserve notice. He was more fortunate in Maryland, for, although the steam project was laughed at, yet one of his friends, a member, very judiciously observed that the grant could injure no one, for he did not think that any man in the world had thought of such a thing before, and therefore he wished the encouragement might be afforded, as there was a prospect that it would produce something useful. This kind of argument had its effect, and Evans received all that he asked for, and from that period considered himself bound in honor to the State of Maryland to produce a steam carriage, as soon as his means would allow him. For several years succeeding the granting of his petition by the Legislature of Maryland, Evans endeavored to obtain some person of pecuniary resources to join with him in his plans; and for this purpose explained his views by drafts, and otherwise, to some of the first mechanics in the country. Although the persons addressed appeared, in several instances, to understand them, they declined any assistance from a fear of the expense and difficulty of their execution. In the year 1800, or 1801, Evans, never having found anyone willing to contribute to the expense, or even to encourage him in his efforts, determined to construct a steam carriage at his own expense. Previous to commencing he explained his views to Robert Patterson, Professor of Mathematics in the University of Pennsylvania, and to an eminent English engineer. They both declared the principles new to them, and advised the plan as highly worthy of a fair experiment. They were the only persons who had any confidence, or afforded encouraging advice. He also communicated his plans to B. F. Latrobe, the scientist, who publicly pronounced them as chimerical, and attempted to demonstrate the absurdity of Evans' principles in his report to the Philosophical Society of Pennsylvania on steam engines. In this he also endeavored to show the impossibility of making steamboats useful. Evans commenced and had made considerable progress in the construction of a steam carriage, when the idea occurred to him that as his steam engine was altogether different in form, as well as in principle, from any other in use, a patent could be obtained for it, and then applied to mills more profitably than to carriages. The steam carriage was accordingly laid aside for a season of more leisure, and the construction of a small engine was commenced, with a cylinder six inches in diameter and a piston of eighteen inches stroke, for a mill to grind plaster of paris. The expense of its construction far exceeded Evans' calculation, and before the engine was finished he found it cost him all he was worth. He had then to begin the world anew, at the age of forty-eight, with a large family to support, and that, too, with a knowledge that if the trial failed his credit would be entirely ruined, and his prospects for the remainder of life dark and gloomy. But fortune favored him, and his success was complete. In a brief account, given by himself, of his experiments in steam, he says: "I could break and grind three hundred bushels of plaster of paris, or twelve tons, in twenty-four hours; and to show its operations more fully to the public, I applied it to saw stone, on the side of Market Street, where the driving of twelve saws in heavy frames, sawing at the rate of one hundred feet of marble in twelve hours, made a great show and excited much attention. I thought this was sufficient to convince the thousands of spectators of the utility of my discovery, but I frequently heard them inquire if the power could be applied to saw timber as well as stone, to grind grain, propel boats, etc., and though I answered in the affirmative, they still doubted. I therefore determined to apply my engine to all new uses; to introduce it and them to the public. This experiment completely tested the correctness of my principles. The power of my engine rises in a geometrical proportion, while the consumption of the fuel has only an arithmetical ratio; in such proportion that every time I added one-fourth more to the consumption of the fuel, its powers were doubled; and that twice the quantity of fuel required to drive one saw, would drive sixteen saws at least; for when I drove two saws the consumption was eight bushels of coal in twelve hours, but when twelve saws were driven, the consumption was not more than ten bushels, so that the more we resist the steam, the greater is the effect of the engine. On these principles very light but powerful engines can be made suitable for propelling boats and land carriages without the great encumbrance of their weight as mentioned in Latrobe's demonstration." In the year 1840, Evans, by order of the Board of Health of Philadelphia, constructed at his works, situated a mile and a half from the water, a machine for cleaning docks. It consisted of a large flat or scow, with a steam engine of five horse-power on board, to work the machinery to raise the mud into the scows. This was considered a fine opportunity to show the public that his engine could propel both land and water conveyances. When the machine was finished, he fixed, in a rough and temporary manner, wheels with wooden axletrees, and, of course, under the influence of great friction. Although the whole weight was equal to two hundred barrels of flour, yet his small engine propelled it up Market Street and round the circle to the waterworks, where it was launched into the Schuylkill River. A paddle-wheel was then applied to its stern, and it thus moved down that river to the Delaware, a distance of sixteen miles, leaving behind all vessels that were under sail. This demonstration was in the presence of thousands of spectators, which he supposed would have convinced them of the practicability of steamboats and steam carriages. But no allowance was made by the public for the disproportion of the engine to its load, nor for the rough manner in which the machinery was fixed, or the great friction and ill form of the boat, and it was supposed that this was the utmost it could perform. Some individuals undertook to ridicule the experiment of driving so great a weight on land, because the motion was too slow to be useful. The inventor silenced them by answering that he would make a carriage propelled by steam, for a wager of three thousand dollars, to run upon a level road, against the swiftest horse that could be produced. This machine Evans named the Oructor Amphibolis. On the 25th of September, 1804, Evans submitted to the consideration of the Lancaster Turnpike Company a statement of the costs and profits of a steam carriage to carry one hundred barrels of flour, fifty miles in twenty-four hours; tending to show that one such steam carriage would make more net profits than ten wagons, drawn by five horses each, on a good turnpike road, and offering to build one at a very low price. His address closed as follows: "It is too much for an individual to put in operation every improvement which he may invent. I have no doubt but that my engines will propel boats against the current of the Mississippi, and wagons on turnpike roads, with great profit. I now call upon those whose interest it is to carry this invention into effect. All of which is respectfully submitted to your consideration." Little or no attention was paid to this offer, for it was difficult at that day to interest anyone in steam locomotion. Evans' interest in the steam carriage forthwith ceased, but in his writings, published about that time, he remarked: "The time will come when people will travel in stages moved by steam engines from one city to another, almost as fast as birds fly, fifteen or twenty miles an hour. Passing through the air with such velocity, changing the scene in such rapid succession, will be the most rapid exhilarating exercise. A carriage (steam) will set out from Washington in the morning, the passengers will breakfast at Baltimore, dine at Philadelphia, and sup at New York in the same day." To accomplish this he suggested railways of wood or iron, or smooth paths of broken stone or gravel, and predicted that engines would soon drive boats ten or twelve miles an hour. In the latter years of his life, Evans established a large iron foundry in Philadelphia. Although Evans' distinct contribution to the problem of steam locomotion on the common roads was not particularly practical it was at least important as being the first suggestion of anything of the kind in the United States. Road conditions in this country at that time were worse than they were in England and yet under more discouraging circumstances he was as far advanced in ideas and plans as his great contemporaries, Trevithick and others across the water. To Evans must be given the credit of perfecting the high-pressure, non-condensing engine, and even Trevithick, "the father of the locomotive," was largely indebted to him for his progress in the lines he was working on in England, his plans and specifications having been sent abroad for the English engineers to inspect in 1784. WILLIAM SYMINGTON Born at Leadhills, Scotland, October, 1783. Died in London, March 22, 1831. More fortunate than most of the English inventors of the seventeenth and eighteenth centuries, with whom he was associated, William Symington came of a family that was able to give him a good education. His father was a mechanic who had charge of the engines and machinery at the Warlockhead lead mines, and the son gained his first knowledge of mechanics and engineering in the shops with his father. Intended for the ministry, he was sent to the University of Glasgow and the University of Dublin to pursue his studies. But the ministry had slight attractions for him, and when the time came for him to choose a profession, he adopted that of civil engineering. In 1786 he worked out a model for a steam road-car. This was regarded very highly by all who saw it. It is said that Mr. Meason, manager of the lead mines at Warlockhead, was so pleased with the model, the merit of which principally belonged to young Symington, that he sent him into Edinburgh for the purpose of exhibiting it before the professors of the University, and other scientific gentlemen of the city, in the hope that it might lead in some way to his future advancement in life. Mr. Meason became the patron and friend of Symington, allowed the model to be exhibited at his own house, and invited many persons of distinction to inspect it. The carriage supported on four wheels had a locomotive behind, the front wheels being arranged with steering-gear. A cylindrical boiler was used for generating steam, which communicated by a steam-pipe with the two horizontal cylinders, one on each side of the firebox of the boiler. When steam was turned into the cylinder, the piston made an outward stroke; a vacuum was then formed, the steam being condensed in a cold water tank placed beneath the cylinders, and the piston was forced back by the pressure of the atmosphere. The piston rods communicated their motion to the driving-axle and wheels through rack rods, which worked toothed wheels placed on the hind axle on both sides of the engine, and the alternate action of the rack rods upon the tooth and ratchet wheels, with which the drums were provided, produced the rotary motion. The boiler was fitted with a lever and weight safety valve. Symington's locomotive was abandoned, the inventor considering that the scheme of steam travel on the common roads was impracticable. Henceforth, Symington gave his attention to the study of boat propulsion by steam. In 1787 he got out a patent for an improved form of steam engine, in which he obtained rotary action by chains and ratchet-wheels. This engine, with a four-inch cylinder, was used to work the paddles of a pleasure boat on Dalswinton Loch, in 1788, the boat steaming at the rate of five miles an hour. This boat is now in the South Kensington Museum, and it has been termed "the parent engine of steam navigation." The experiment with this method of boat propulsion was so successful that a year later larger engines, with eighteen-inch cylinders, were fitted to another boat, which attained a speed of seven miles an hour. In 1801, Symington took out a patent for an engine with a piston rod guided by rollers in a straight path and connected by a rod with a crank attached directly to the paddle-wheel shaft--the system that has been in use ever since. Although the perfect practicability of this method of boat propulsion was fully demonstrated by a trial on the tugboat Charlotte Dundas, in March, 1802, the plan for steam power on canals and lakes was not carried further. The Forth and Clyde Company, and the Duke of Bridgewater, who were backing Symington, gave up the project and he could get help from no other sources. His inventions and experiments are generally regarded as marking the beginning of steam navigation. It is interesting to note that among those who were guests on the Charlotte Dundas, on the occasion of this trial trip, was Robert Fulton, who wrote a treatise on steam navigation in 1793, tried a small steamboat on the river Seine, in France, in 1803, and in 1807 launched his famous steamship, the Clermont, on the Hudson River. Symington, disappointed and discouraged, gave up his work and went to London. The rest of his life was for the most part thrown away, and he became one of the waifs and strays of London. In 1825 he received a grant of one hundred pounds from the privy purse, and later on fifty pounds more, in recognition of his services for steam navigation. He died in obscurity and although he was unquestionably the pioneer in his country of the successful application of steam to navigation on inland waters his name is only a bare memory. NATHAN READ Born in Warren, Mass., July 2, 1759. Died near Belfast, Me., January 20, 1849. Graduated from Harvard College in 1781, Read was a tutor at Harvard for four years. In 1788 he began experimenting to discover some way of utilizing the steam engine for propelling boats and carriages. His efforts were mainly directed toward devising lighter, more compact machinery than then generally in use. His greatest invention at that time was a substitute for the large working-beam. This was a cross-head beam which ran in guides and had a connecting-rod with which motion was communicated. The new cylinder that he invented to attach to this working-frame was double-acting. In order to make the boiler more portable he invented a multi-tubular form, and this he patented, together with the cylinder, chain-wheel, and other appliances. The boiler was cylindrical and was placed upright or horizontal, and the furnace was carried within it. A double cylinder formed a water-jacket, connected with a water and steam chamber above, and a water-chamber below. Numerous small straight tubes connected these two chambers. Read also invented another boiler in which the fire went through small spiral tubes, very much as it does in the present-day locomotives, and this was a smoke-consuming engine. For the purpose of acquiring motion he first used paddle-wheels, but afterward adopted a chain-wheel of his own invention. [Illustration: NATHAN READ] Read planned a steam-car to be run with his tubular boiler, and it is said that this vehicle, when laden with fifty tons weight, could make five miles per hour. The model which was completed in 1790 had four wheels, the front pair being pivoted at the center and controlled by a horizontal sheave and rope. The sheave was located back near the boiler, and in guiding the machine it was operated by a hand-wheel placed above the platform, within easy reach of the engineer. A square boiler with Read's multi-tubular system, overhung at the rear of the carriage. Two driving-wheels were forward of the boiler, and in front of these were two horizontal cylinders on each side of the engine. On the inside of each wheel were ratched teeth that fitted into corresponding teeth on horizontal racks above and below the hub. The piston, moving back and forth from the cylinder, engaged these teeth and caused a revolution of the wheel. There were two steam valves and two exhaust valves to each cylinder, the exhaust being into the atmosphere. Although this was the first conception of propulsion by steam on land in America, Read went no further in creating this model, inasmuch as he received no encouragement from financial sources. In 1796, Read established at Salem, Mass., the Salem Iron Foundry, where he manufactured anchors, chain cables, and other machinery. In January, 1798, he invented a machine to cut and head nails at one operation. He also invented a method of equalizing the action of windmills by accumulating the force of the wind through winding up a weight; and a plan for harnessing the force of the tides by means of reservoirs which, by being alternately filled up and emptied, created a constant stream of water. Among his other inventions were a pumping engine and a threshing machine. RICHARD TREVITHICK Born in Illogan, in the west of Cornwall, England, April 13, 1771. Died in Dartford, Kent, April 22, 1833. Richard Trevithick had meager educational advantages. His father was manager of the Dolcoath and other mines, and shortly after the birth of his son moved to Penponds, near Camborne, where the boy was sent to school to learn reading, writing and arithmetic, which were the limits of his attainments. Early in life he showed the dawning of remarkable inventive genius, was quick at figures and clever in drawing. He developed into a young man of notable physique, being six feet two inches high, and having the frame and the strength of an athlete. He was one of the most powerful wrestlers in the west country, and it is related of him that he could easily lift a thousand-weight mandril. At the age of eighteen young Trevithick began to assist his father as mine manager, and at once proceeded to put his inventive faculty to practical test. His initial success, in 1795, was an improvement upon an engine at the Wheal Treasury mine, which accomplished a great saving in fuel and in power, and won for him his first royalty. Before his father died, in 1797, he had attained to the position of engineer at the Ding Dong mine, near Penzance, and had already set up at the Herland mine the engine built by William Bull, with improvements of his own. His earliest invention of importance was in 1797, when he made an improved plunger pump, which, in the following year, he developed into a double-acting water-pressure engine. One of these engines, set up in 1804, at the Alport mine, in Derbyshire, was run until 1850. [Illustration: RICHARD TREVITHICK] In 1780 he built a double-acting high-pressure engine with a crank, for Cook's Kitchen mine. This was known as the Puffer, from the noise that it made, and it soon came into general use in Cornwall and South Wales, a successful rival of the low-pressure steam vacuum engine of Watt. As early as 1796 Trevithick began to give attention to the subject of steam locomotion, and a model constructed by him before 1800 is now in the South Kensington Museum. He busied himself in designing and building a steam vehicle to travel upon the common highways. The work was done in a workshop at Camborne, and some of it in the shop of Captain Andrew Vivian. It was Christmas Eve of 1801 when this steam locomotive was completed and was brought out for trial. The following account of the first trial was made by one who was present: "I knew Captain Dick Trevithick very well. I was a cooper by trade, and when Trevithick was making his steam carriage I used to go every day into John Tyack's shop at the Weith, close by here, where they put her together. In the year 1801, upon Christmas Eve, towards night, Trevithick got up steam, out on the high road, just outside the shop. When we saw that Trevithick was going to turn on steam, we jumped up, as many as could, maybe seven or eight of us. 'Twas a stiffish hill going up to Camborne Beacon, but she went off like a little bird. When she had gone about a quarter of a mile there was a rough piece of road covered with loose stones. She didn't go quite so fast, and as it was a flood of rain, and we were very much squeezed together, I jumped off. She was going faster than I could walk, and went up the hill about half a mile further, when they turned her and came back again to the shop." The next day the engine steamed to Captain Vivian's house, and a few days subsequently, Trevithick and Vivian started off for Tehidy House, where Lord Dedunstanville lived, some two or three miles from Camborne. On this journey they met with an accident, the engine being overturned in going around a curve; but they got back safely. This carriage presented the appearance of an ordinary stage coach on four wheels. The engine had one horizontal cylinder which, together with the boiler and the furnace-box, was placed in the rear of the hind axle. The-motion of the piston was transmitted to a separate crank-axle, from which, through the medium of spur-gear, the axle of the driving-wheel, which was mounted with a fly-wheel, derived its motion. The steam cocks and the force-pump, as also the bellows used for the purpose of quickening combustion in the furnace, were worked off the same crank axle. This was one of the first successful high-pressure engines constructed on the principle of moving a piston by the elasticity of steam against the pressure only of the outside atmosphere. In the following year Trevithick went to London with his cousin, Andrew Vivian, and secured a patent. Early in 1803 he made his second steam carriage. This was built at Camborne and taken to London, via Plymouth, for exhibition. Its journey along the highways thoroughly alarmed the country people. Coleridge relates that a toll-gate keeper was so frightened at the appearance of the sputtering, smoke-spitting thing of fearsome mien that, trembling in every limb and with teeth chattering, he threw aside the toll-gate with the scared exclamation, "No--noth--nothing to pay. My de--dear Mr. Devil, do drive on as fast as you can. Nothing to pay!" The engine in this carriage had a cylinder five and one-half inches in diameter, with a stroke of two and one-half feet, and with thirty pounds of steam it worked five strokes per minute. In every way it was superior to its predecessor. It was not so heavy; and the horizontal cylinder, instead of the vertical, added very much to its steadiness of motion; while wheels of a larger diameter enabled it the more easily to pass over rough roads which had brought the Camborne one to a standstill. The boiler was made entirely of wrought iron, and the cylinder was inserted horizontally, close behind the driving axle. A forked piston-rod was used, the ends working in guides, so that the crank axle might be brought near to the cylinder. Spur gearing and couplings were used on each side of the carriage for communicating motion from the crank shaft to the main driving axle. The driving-wheels were about ten feet diameter, and made of wood. The framing was of wrought iron. The coach was intended to seat eight or ten persons, and the greater part of the weight came on the driving axle. The coach was suspended upon springs. The London steam carriage was put together at Felton's carriage shop, in Leather Lane, and after its completion, Vivian one day ran the locomotive from Leather Lane, Gray's Inn Lane, on to Lords' Cricket Ground, to Paddington, and home again by way of Islington, a journey of ten miles through the streets of London. Several trips were made in Tottenham Court Road and Euston Square, and only once did they meet with accident. Finally, however, the frame of the carriage got twisted, and the engine was detached and set to driving a mill. Trevithick's next experiment was made in 1803-4, while he was engineer of the Pen-y-darran iron works, near Merthyr Tydvil, where he built and ran on a railway a locomotive that was fairly successful. In 1808 he built a locomotive for a circular railway or steam circus that he and Andrew Vivian set up in London, near Euston Square. This ran for several weeks, carrying passengers at the rate of twelve or fifteen miles an hour around curves of fifty or one hundred feet radius. One day a rail broke and the engine was overturned, which ended the exhibition. Subsequently, Trevithick applied his high-pressure engine to rock-boring and breaking, and dredging. He laid out a system of dredging the Thames River, planned a tunnel under the Thames, invented a high-pressure steam threshing engine in 1812, constructed iron tanks and buoys, and modeled an iron ship. He was one of the first to conceive the practical use of steam in agriculture, declaring that the use of the steam engine for this purpose would "double the population of the kingdom and make our markets the cheapest in the world." In 1814, Trevithick became interested in a plan to work the silver mines of Peru by Cornish methods, and nine of his high-pressure engines were sent to South America in charge of Henry Vivian and other engineers. He himself followed in 1816, and remained in that country ten years, making and losing several fortunes during that time. Finally, in a revolution, the mining plants were destroyed, and he was forced to leave the country, penniless. For a time he was prospecting in Costa Rica, where he planned a railroad across the Isthmus from the Atlantic to the Pacific. In 1827 he returned to England, still a poor man, and settling in Dartford, Kent, devoted himself to new inventions, unsuccessfully endeavoring to secure the help of the government in his work. His later years were spent in poverty, and when he died, the expense of his burial was borne by his fellow-workmen of Dartford. Undoubtedly, Trevithick was one of the foremost English engineers of his day, a period that was rich with strong men of distinction in his profession. By many he has been considered as having contributed more even than James Watt to the development of the steam engine and its broader adaptation to practical uses. In his early years he was restrained in putting his ideas and experiments to practical test by the restrictions of Watt's patents. Finally when that difficulty was removed he at once took a leading position in his profession. Especially in the development of the high pressure engine he is entitled to at least as much credit as any man of his day. His genius was fully recognized in his generation and his impoverished old age was the result of financial reverses in business operations and not from the lack of substantial rewards for his inventive achievements. DAVID GORDON The first experiments of David Gordon, who in 1819 was working with William Murdock, in Soho, were for the purpose of using compressed air for common road locomotives. He also invented a portable gas apparatus, and originated a society of gentlemen, with the intention of forming a company for the purpose of running a mail coach and other carriages by means of a high-pressure engine, or of a gas vacuum or pneumatic engine, supplied with portable gas. Alexander Gordon, his son, states that "the committee of the society had only a limited sum at their disposal, nor were there to be more funds until a carriage had been propelled for a considerable distance at the rate of ten miles an hour." David Gordon then tried to prevail upon the committee to make use of a steam engine, but evidently without success. In 1821 he took out a patent for improvements in wheel carriages, and his locomotive is fully described in the interesting Treatise on Elemental Locomotion, by Mr. Alexander Gordon. The machine consisted of a large hollow cylinder about nine feet in diameter and five long, having its internal circumference provided with a continuous series of cogged teeth, into which were made to work the cogged running wheels of a locomotive steam engine, similar to that of Trevithick. The steam power being communicated to the wheels of the carriage, caused them to revolve, and to climb up the internal rack of the large cylinder. The center of gravity of the engine being thus constantly made to change its position, and to throw its chief weight on the forward side of the axis of the cylinder, the latter was compelled to roll forward, propelling the vehicle before it, and whatever train might be added. Gordon's next attempt to construct locomotive carriages for the common road was in 1824. The means proposed was a modification of the method invented by William Brunton. But instead of the propellers being operated upon by the alternating motion of the piston-rod, as in Brunton's vehicle, Gordon contrived to give them a continuous rotatory action and to apply the force of the engines in a more direct manner. The carriage ran upon three wheels, one in the front to steer by, and two behind to bear the chief weight. Each of the wheels had a separate axle, the ends of which had their bearings upon parallel bars, the wheels rolling in a perpendicular position. This arrangement, by avoiding the usual cross-axle, afforded an increased uninterrupted space in the body of the vehicle. In the fore part of the carriage were placed the steam engines, consisting of two brass cylinders, in a horizontal position, but vibrating upon trunnions. The piston-rods of these engines gave motion to an eight-throw crank, two in the middle for the cylinders, and three on each side, to which were attached the propellers; by the revolution of the crank, these propellers or legs were successively forced outwards, with the feet of each against the ground in a backward direction, and were immediately afterwards lifted from the ground by the revolution of another crank, parallel to the former, and situated at a proper distance from it on the same frame. The propelling-rods were formed of iron gas-tubes, filled with wood, to combine lightness with strength. To the lower ends of these propelling-rods were attached the feet, in the form of segments of circles, and made on their under side like a short and very stiff brush of whalebone, supported by intermixed iron teeth, to take effect in case the whalebone failed. These feet pressed against the ground in regular succession, by a kind of rolling, circular motion, without digging it up. The guide had the power of lifting these legs off the ground at pleasure, so that in going down hill, when the gravity was sufficient for propulsion, nothing but a brake was put into requisition to retard the motion, if necessary. If the carriage was proceeding upon a level, the lifting of the propellers was equivalent to the subtraction of the power, and soon brought it to a full stop. When making turns in a road the guide had only to lift the propellers on one side of the carriage and allow the others to operate alone, until the curve was traversed. Gordon got fair results from this locomotive, but the speed was not satisfactory. In his first trials he found the power insufficient. He afterwards fitted one of Gurney's light boilers in the hinder part of the carriage, though even after this improvement had been added the experiments were disappointing. Gordon was convinced that the application of the power to the wheels was the proper mode of propulsion, and his project was abandoned after six or seven years had been spent in inventing, constructing, and carrying out experiments with four distinct carriages. WILLIAM HENRY JAMES Born at Henley, England, March, 1776. Died at Dulwich College Alms House, December 16, 1873. The father of William Henry James was William James, of Warwickshire, the great railway projector of his time. He was a solicitor in early life, but became wealthy, worked a colliery in South Staffordshire, and in 1815 removed to London, where he had a large land agency business. He became interested in tramways in 1806, and from that date on devoted most of his energies and fortune to projecting railways in the United Kingdom. He had an interest in one of George Stephenson's patents, made numerous railway surveys, and by many has been considered to have done more than any single individual in laying the foundations of the English railroad system. William Henry James assisted his father in his railway surveys in early life, and then began business independently as an engineer, in Birmingham. He made experiments in steam locomotion on common roads, and took out patents for locomotive steam engines, boilers, driving apparatus, and so on. His patent for a water-tube boiler for road locomotives was secured in 1823, and his first car was built in 1824. This was a twenty-passenger steam coach. Each rear wheel had a double-cylinder engine, and the pistons were worked at a pressure of two hundred pounds per square inch. Separate engines to each driver gave each wheel an independent motion, so that power and speed might be varied for turning corners, the outer wheel travelling over a much greater space than the inner wheel. When the front wheels were so placed that the carriage proceeded in a straight line an equal amount of steam was admitted to each pair of cylinders, but when the front wheel was in the lock the engine driving the outer wheel received a greater amount of steam and thus developed more power and traveled faster than the inner wheel. This arrangement was said to be so efficient that the carriage could be made to describe every variety of curve, repeatedly making turns of less than ten feet radius. The whole of the machinery was mounted upon laminated carriage springs. This arrangement caused the engines and their framework to vibrate altogether upon the crank-shaft as a center, at the same time connecting these engines to the boiler by means of hollow axles moving in stuffing boxes. Each engine had two cylinders of small diameter and long stroke; to these separate engines steam was supplied from the boiler by means of the main pipe, which moved through steam-tight stuffing boxes to the slide valve-boxes by small pipes. The locomotive was entirely distinct from the passenger carriage. Sir James C. Anderson became associated with James, and in 1829 they built another carriage. This weighed nearly three tons, and the first trials were made round a circle of one hundred and sixty feet in diameter. When it was finally ready to be brought out it was loaded with fifteen passengers and driven several miles on a rough gravel road across Epping Forest, with a speed varying from twelve to fifteen miles an hour. Steam was supplied by two tubular boilers, each forming a hollow cylinder four feet six inches long. The tubes of which the boilers were composed were common gas pipe, one of which split on one of the trips, thus letting the water out of one of the boilers and extinguishing its fire. Under these circumstances, with only one boiler in operation, the carriage returned home at the rate of about seven miles an hour, carrying more than twenty passengers--at one period, indeed, it is said, a much greater number; showing that sufficient steam could be generated in such a boiler to be equal to the propulsion of between five and six tons weight. In consequence of this demonstration that the most brilliant success was attainable, the proprietors dismantled the carriage and commenced the construction of superior tubular boilers with much stronger tubes. Shortly after Anderson and James commenced to build another steam carriage, which was ready for use in November, 1829. This engine was not intended to carry passengers, but to be employed for drawing carriages behind. Four tubular boilers were used, the total number of tubes being nearly two hundred. These boilers were enclosed in a space four feet wide, three feet long, and two feet deep. The steam from each boiler was conducted into one main steam pipe one and one-half inches in diameter, and the communication from any one of the boilers could be cut off in case of leakage. Four cylinders, each two and one-quarter inch bore and nine inch stroke, were arranged vertically in the hind part of the locomotive, and two of them acted upon each crank-shaft as before, giving a separate motion to each driving wheel. The exhaust steam was conducted through two copper tanks for heating the feed water to a high temperature, and thence passed to the chimney. The steering-gear consisted of an external pillar containing a vertical shaft, at the upper end of which small bevel-gearing was used, giving motion to the vertical shaft, whose bottom end carried a pinion gearing into a sector attached to the fore axle. The motion of the crank-shafts was communicated to the separate axles of the driving-wheels by spur-gearing with two speeds. In experiments made with this carriage, the greatest speed obtained upon a level, on a very indifferent road, was at the rate of fifteen miles an hour, and it never ran more than three or four miles without breaking some of the steam joints. The Mechanic's Magazine, reporting one of these trials, said: "A series of interesting experiments were made throughout the whole of yesterday with a new steam carriage belonging to Sir James Anderson, Bart., and W. H. James, Esq., on the Vauxhall, Kensington, and Clapham roads, with the view of ascertaining the practical advantages of some perfectly novel apparatus attached to the engines, the results of which were so satisfactory that the proprietors intend immediately establishing several stage coaches on the principle. The writer was favored with a ride during the last experiment, when the machine proceeded from Vauxhall Bridge to the Swan at Clapham, a distance of two and a half miles, which was run at the rate of fifteen miles an hour. From what I had the pleasure of witnessing, I am confident that this carriage is far superior to every other locomotive carriage hitherto brought before the public, and that she will easily perform fifteen miles an hour throughout a long journey. The body of the carriage, if not elegant, is neat, being the figure of a parallelogram. It is a very small and compact machine, and runs upon four wheels." W. H. James patented another steam carriage in August, 1832. This varied much from his earlier engines in the working parts, and it was not generally considered to be as satisfactory as the others. Sir James Anderson was not able, for pecuniary reasons, to continue to back James in his experimenting, and it does not appear that these plans of 1832 were ever consummated in a completed vehicle. James was a man of strong mind, an original thinker and thoroughly well-trained by his apprenticeship with his father. He spent a good part of his life in experimenting with common-road steam propulsion, but he had not monetary resources or financial ability commensurate with his mechanical genius. When the support of Anderson was withdrawn from him he seems to have been compelled to give up. Little has been recorded concerning the latter years of his life, and his death in the almshouse sufficiently indicates the poverty in which his last years were spent. His father also sacrificed his life to the cause of railroad advancement, losing his entire fortune and dying a poor man. GOLDSWORTHY GURNEY Born at Treator, near Padstow, Cornwall, England, February 14, 1793. Died at Reeds, near Bade, February 28, 1875. The son of John Gurney, Goldsworthy Gurney received a good elementary education at the Truro Grammar School, and then studied medicine. He settled at Wadebridge as a surgeon, but although very successful, gradually turned his attention to scientific and mechanical investigations. He constructed an organ, studied chemistry and mechanical science, and removing to London in 1820, delivered a series of lectures on heat, electricity and gases at the Surrey Institute. His investigations resulted in the invention of the oxy-hydrogen blowpipe, and the discovery of the powerful lime-light known as the Drummond light, and he engaged in other experiments in this field of research. In 1804, while on a holiday at Camborne, he saw a Trevithick engine on wheels. Recalling this in after years he began experimenting on steam locomotion in 1823, and soon abandoned his surgical and medical practice for this new pursuit. His first efforts were toward the construction of an engine to travel on the common roads. The weight of the steam engines that were then being built seemed to him to offer great objections to their use for this purpose, but he succeeded, with his first machine, in reducing weight from four tons to thirty hundredweight. Then he secured a sufficiency of power by the invention of the high-pressure steam jet. This invention differed from those of Stephenson and Trevithick, who sent their waste steam up through the chimney instead of utilizing it. The Gurney jet was applied to the Stephenson Rocket engine on the Liverpool and Manchester Railway, in October, 1829, and also to steamboats and steam carriages. In 1823, Gurney made his first experiments with a model steam carriage, on which propellers or feet were used. Two years later, in 1825, he completed a full-size carriage on the same plan, and in May of that year he took out his first patent for this vehicle. The carriage was impelled by these legs being alternately drawn forwards and pressed backwards by a steam engine acting upon them through movable oblong blocks, to which they were attached. As a first experiment this carriage was driven up Windmill Hill, near Kilburn. Another trip, between London and Edgeware, demonstrated the inefficiency of these propellers, and led to the discovery that there was sufficient friction between wheels and the ground to insure propulsion. In 1826 he constructed a coach about twenty feet long, which would accommodate six inside and fifteen outside passengers, besides the engineer. The driving-wheels were five feet diameter, and the leading wheels three feet nine inches diameter. Two propellers were used, which could be put in motion when the carriage was climbing hills. Gurney's patent boiler was used for supplying steam to the twelve horse-power engine. The total weight of the carriage was about a ton and a half. In front of the coach was a capacious boot, while behind, that which had the appearance of a boot, was the case for the boiler and the furnace, from which it was calculated that no inconvenience would be experienced by the outside passenger, although in cold weather a certain degree of heat might be obtained, if required. In descending a hill, there was a brake fixed on the hind wheel, to increase the friction; but, independently of this, the guide had the power of lessening the force of the steam to any extent by means of the lever at his right hand, which operated upon the throttle valve, and by which he could stop the action of the steam altogether and effect a counter vacuum in the cylinders. By this means also he regulated the rate of progress on the road. There was another lever by which he could stop the vehicle instantly, and in a moment reverse the motion of the wheels. This carriage traveled up Highgate Hill to Edgeware, and also to Stanmore, and went up both Stanmore Hill and Brockley Hill. In ascending these hills the driving-wheels did not slip, so that the legs were not needed. After these experiments the propellers were removed. Gurney obtained another patent in 1827, and under this worked a steam carriage resembling the common stage coach, with the boiler in the hind boot. This carriage was run experimentally to Barnet, Edgeware, Finchley, and other places, and in 1828 it was said that a trip was made from London to Melksham, thirteen miles from Bath, a distance of nearly two hundred miles. On the return trip the rate of speed was about twelve miles an hour. Gurney's carriage so fully established its practicability, that in 1830, Sir Charles Dance contracted for several, and ran them successfully from London to Holyhead, and from Birmingham to Bristol. In the following year he ran over the turnpike road between Gloucester and Cheltenham for four months in succession, four times a day, without an accident or delay of consequence. The distance of nine miles was regularly covered in from forty-five to fifty-five minutes. Nearly three thousand persons were carried, and nearly four thousand miles traveled. A strong public sentiment against the use of the common roads by these vehicles sprang up, and Parliament was prevailed upon to impose upon steam carriages heavy highway tolls that were in effect prohibitory. Sir Charles Dance suspended his operations. Gurney petitioned the House of Commons for relief. Several committees in 1831, 1834 and 1835 investigated the subject and reported strongly in favor of steam carriages, but no legislation could be secured, and Gurney was forced to give up further introduction of steam carriages. He continued his experimenting in other directions, invented the stove that bore his name, introduced new methods of lighting and ventilating the Houses of Parliament, and was otherwise active in scientific pursuits. He was a magistrate for Cornwall and Devonshire, and in 1863 was knighted in recognition of his discoveries and inventions. By writers of that period Gurney received a great deal of credit and an abundance of advertising for his work. He was especially conspicuous in the Parliamentary investigations regarding steam carriages. On the whole, however, it is generally considered that he was proclaimed far beyond his merits, especially in comparison with such rivals as Hancock, Maceroni and others. THOMAS BLANCHARD Born in Sutton, Mass., June 24, 1788. Died, April 16, 1864. Blanchard received a common school education, and before he had entered his teens his mechanical genius began to show itself. At thirteen years of age he invented a machine for paring apples, and shortly after, a machine for making tacks. His great work was the invention of a machine for turning out articles of irregular form from wood and metals. His lathes for this purpose were put in operation by the United States Government in the armories at Harper's Ferry, Va., and Springfield, Mass. Becoming interested in the subject of steam propulsion he made, in 1826, a steamboat that was successfully tried on the Connecticut River, running from Hartford, Conn., to Springfield, Mass. Afterward, he built a boat of larger size, that drew eighteen inches of water, and ran this up the Connecticut River, from Springfield, Mass., to Vermont. He also built other boats for use on the Alleghany River. The subjects of railroads and locomotive power on land interested him for a short time, and in 1825, after he had completed his engagement with the United States armories, he built, at Springfield, Mass., a carriage driven by steam for use on the common road. This was the first real steam carriage constructed in this country, the Philadelphia machine of Evans being but a rude affair, although it involved the essential principles of steam propulsion. The Blanchard carriage was perfectly manageable, could turn corners and go backwards and forwards with all the readiness of a well-trained horse, and on ascending a hill the power could be increased. Its performance on the highway was altogether satisfactory, and a patent was issued to its inventor. [Illustration: THOMAS BLANCHARD] Blanchard endeavored to secure support to build a railroad in Massachusetts, and the joint committee on roads and canals of the Massachusetts Legislature, in January, 1826, endorsed the model of his railway and steam carriage, and recommended them "to all the friends of internal improvements." Notwithstanding this report, capitalists viewed the project as visionary, and Blanchard met with no greater success when he subsequently applied to the Legislature of New York. Giving up his plans he thenceforward devoted his attention to the subject of steam navigation. Blanchard was a prolific inventor, having taken out no less than thirty or forty patents for as many different inventions. He did not reap great benefit from his labors, for many of his inventions scarcely paid the cost of getting them up, while others were appropriated without payment to him, or even giving him credit. His machine for turning irregular forms was his most notable work, and even of that, others sought to defraud him. To defend himself he was forced to go to the courts and even to Congress, before he succeeded in establishing his rights. After the success of this machine he made other improvements in the manufacture of arms, constructing thirteen different machines that were operated in the government armories. JOHNSON Two brothers Johnson had a small engineering establishment in Philadelphia, in 1828. They put upon the streets in that year a vehicle that J. G. Pangborn, in his The World's Rail Way, says was "the first steam wagon built, and actually operated as such, in the United States." The same writer, describing this wagon, says that it had a single cylinder set horizontally, with a connecting-rod attachment with a single crank at the middle of the driving-axle. Its two driving-wheels were eight feet in diameter and made of wood, the same as those on an ordinary road wagon. The two forward or guiding wheels were much smaller than the others, and were arranged in the usual manner of a common wagon. It had an upright boiler hung up behind, shaped like a huge bottle, the smoke-stack coming out through the center of the top. The safety-valve was held down by a weight and lever, and the horses in the neighborhood did not take at all kindly to the puffing of the machine as it jolted over the rough streets. Generally it ran well, and could take without difficulty reasonable grades in the streets and roadways. During its existence, however, it knocked down a number of awning-posts, ran into and broke several window fronts, and sometimes was altogether unmanageable. Like all others of their day, however, the Johnsons were ahead of their time. There was no demand for their steam wagon, road conditions made it unavailable and the machine itself was, despite much merit, really not much more than a suggestion of better things three-quarters of a century later. WALTER HANCOCK Born in Marlborough, Wiltshire, England, June 16, 1799. Died May 14, 1852. The father of Walter Hancock was James Hancock, a timber merchant and cabinet maker. Walter received a common school education, and then was apprenticed to a watchmaker and jeweler in London. The bent of his inclination, however, was toward engineering, and he turned his attention to experimenting along the lines that were at that time absorbing the thoughts and efforts of those men of England interested in mechanical and scientific subjects. He was foremost among those who in the early part of the nineteenth century were engaged in trying to solve the problem of steam carriage locomotion on the common highways. The story of his work in this direction is fully told by himself in his Narrative of Twelve Years' Experiments, 1824-36, Demonstrative of the Practicability and Advantage of Employing Steam Carriages on Common Roads, a book published in London, in 1838. This volume contains a full account of his labors, and descriptions of all the carriages that he built and ran. The following extract from the introduction of the book shows in what esteem Hancock regarded himself and what estimate he placed upon the value of his work: "The author of these pages believes he should offend alike against truth and genuine modesty were he to yield to any of the steam carriage inventors who have appeared in his day, in a single particular of desert; he began earlier (with one abortive exception) and has persevered longer and more unceasingly than any of them. He was the first to run a steam carriage for hire on a common road, and is still the only person who has ventured in a steam vehicle to traverse the most crowded streets of the metropolis at the busiest periods of the day; he has built a greater number of steam carriages (if not better) than anyone else, and has been thus enabled to try a greater variety of forms of construction, out of which to choose the best." In 1824, Hancock invented a steam engine in which the ordinary cylinder and piston were replaced by two flexible steam receivers, composed of several layers of canvas firmly united together by coatings of dissolved caoutchouc, or india-rubber, and thus enabled to resist a pressure of steam of sixty pounds upon the square inch. This engine he tried to adapt to steam carriages, but found that he could not get the requisite degree of power for locomotion, although it worked very well as a stationary engine of four horse-power at his factory in Stratford. Next he invented a tubular boiler with sixteen horizontal tubes, each connected with each other by lesser tubes, so that the water or steam might circulate through the entire series. This boiler was subsequently changed by arranging the tubes vertically, and a patent was taken out in 1825. After further experiments and improvements, Hancock finally made a vehicle to travel on three wheels, getting power from a pair of vibrating or trunnion engines fixed upon the crank-axle of the fore wheels. Experimental trips of this carriage were made from the Stratford shop to Epping Forest, Paddington, Hounslow, Croydon, Fulham, and elsewhere. Some changes were made in the vehicle, and finally the trunnion engines were put aside and fixed ones substituted. This improved carriage, the first in a long series built by Hancock, was named the Infant. The body was in the form of a double-body coach, or omnibus, with seats for passengers inside and out. The bulk of the machinery was placed in the rear of the carriage, a boiler and a fire being beneath it. Between the boiler and the passengers' seats was the engine and a place for the engineer. A pair of inverted fixed engines working vertically on a crank-shaft furnished the power. The steering apparatus was in front. The whole carriage was on one frame supported by four springs on the axle of each wheel. The carriage was capable of carrying sixteen passengers besides the engineer and guide. Its total weight, including coke and water, but exclusive of attendants and passengers, was about three and one-half tons. The wheel tires were three and one-half inches wide, and the diameter of the hind wheels four feet. In February, 1831, the Infant began to run on regular trips between Stratford and London. In 1832 a second carriage, similar to the Infant, was built, and called the Era. It was constructed for the London and Brighton Steam Carriage Company, to ply between London and Greenwich. The following year a third carriage, the Enterprise, was completed, for the London and Paddington Steam Car Company, and was run between London and Paddington. Hancock took the Infant on a long trip from Stratford to London and Brighton, in October, 1832. Eleven passengers were carried, and the carriage kept a speed of nine miles an hour on the level, and six to eight miles an hour up grade. On the return one mile up hill was made at the rate of seventeen miles an hour. Another trip to Brighton was made in September of the next year at an average speed of twelve miles an hour actual traveling. At Brighton the new carriage attracted much attention, and was exhibited for several days on trips in and around the town. After the Enterprise, the Autopsy came from the Hancock shops, in September, 1833. This carriage was run on trial about Brighton and in London streets, and for about a month was run for hire between Finsbury Square and Pentonville. A small steam drag or tug to draw an attached coach or omnibus was the next production of the Hancock establishment, which had already attained more than local fame. This was built for a Herr Voigtlander, of Vienna, and on one of its trial trips it carried ten persons and an attached four-wheeled carriage with six persons in it. With this load a speed of fourteen miles an hour on the level was attained, and eight to nine miles an hour on up grades. Beginning in August, 1834, the Era and the Autopsy were run daily in London between the City, Moorgate and Paddington. During the ensuing four months over four thousand passengers were carried. Each coach carried from ten to twelve passengers, and the trip from Moorgate to Paddington, five miles, was made in a half hour, including stops. On the trial trip a speed of twelve miles an hour, exclusive of stops, was maintained. Later in the same year the Era, with its name changed to the Erin, was sent to Dublin, Ireland, where it was exhibited and run in and about the city, by Hancock, for eight days, before it was reshipped to Stratford. Next in turn came a drag of larger size than any before built, with an engine of greater capacity. On the trial trip this drew, on a level road, at a speed of ten miles an hour, three omnibuses and one stage coach with fifty passengers. In July, 1835, the trip to Reading, a distance of thirty-eight miles, was made in three hours forty minutes twenty-five seconds; actual running time, exclusive of stops, three hours eight minutes ten seconds, at a moving rate of over twelve miles an hour. Subsequently, this drag was made over into a carriage, like the others of the Hancock type, fitted for eighteen passengers, and named the Automaton. In August, 1835, the Erin ran from London to Marlborough, a distance of seventy-eight miles, in seven hours forty-nine minutes, exclusive of stops, averaging nine and six-tenths miles an hour. The return from Marlborough to London was accomplished in seven hours thirty-six minutes, exclusive of stops, an average of nine and eight-tenths miles an hour. In the same month the Erin made the run from London to Birmingham at the rate of ten miles an hour. In 1836, Hancock ran all his carriages on a regular route on the Stratford and Islington roads for a period of twenty weeks, making in that time seven hundred and twelve trips, covering four thousand two hundred miles, and carrying twelve thousand seven hundred and sixty-one passengers. After running his carriages for several years dissensions in the companies that were promoting the new means of travel, and the increasing efficiency of railways, led to the discontinuance of Hancock's energy in this direction. Thereafter he built only a steam phaeton for his personal use; this had seats for three, and was used about the City, Hyde Park and the London suburbs. Hancock's steam vehicles were ten in number--the experimental three-wheeler, the trunnion-engine Infant, the fixed engine Infant, the Era, afterward the Erin, the Enterprise, the Autopsy, the Austrian drag, the Irish drag, the Automaton, and the phaeton. Hancock turned his attention in the later years of his life to developing the use of india-rubber, in connection with his brother, Thomas Hancock, who was one of the foremost rubber manufacturers of England. He secured several patents for improvements in manufacturing rubber. At the time when Hancock was at work upon his steam carriages, Gurney was also in the front and there was considerable jealousy between the two. Dr. Lardner and others were active in exploiting Gurney, while Hancock was supported in controversies by Alexander Gordon, Luke Hebert and others. That Hancock achieved most in the way of definite results and that his experimenting and accomplishments were more markedly along thoroughly intelligent and conservatively practical mechanical lines than any of his rivals is now generally conceded. His carriages were admirable productions as road vehicles, well-built, attractive and comfortable. WILLIAM T. JAMES An engineer of New York, who was engaged in experimenting about 1829 James made, in his shop in Eldridge Court, several small models of vehicles that proved sufficiently satisfactory. His first engine had two-inch cylinders and four-inch stroke. This ran around a track on the floor of his shop, and drew a train of four cars, carrying an apprentice boy on each car. James' second locomotive was mounted on three wheels, two drivers in the rear and a steering wheel, and it ran on the floor or sidewalk. In 1829, James, satisfied with his experimenting, built a steam carriage capable of carrying passengers, and with this he made very good time over the streets and roadways in and about the metropolis. He then adopted the rotary cylinders instead of the reciprocating, in his engine, which had two six-inch cylinders, and was supported on three wheels. On each cylinder were two fixed eccentrics, one for the forward and one for the backing motion. The slide valve of one cylinder had a half-inch lap at each end, and exhausted its steam into the other. In 1830, James made his fourth full-size steam carriage. This was a three-wheeled vehicle, the rear wheels being drivers three feet in diameter, and the third the front or steering wheel. In 1831, in a competition for the best locomotive engine adapted to the Baltimore and Ohio Railroad Company, James built his fifth locomotive, and the first one to run on rails. His engine did not secure the prize, but the company, thinking his machine contained valuable ideas, entered into an arrangement with him for further experimenting. FRANCIS MACERONI Born in Manchester, England, in 1788. Died in London, July 25, 1846. The father of Francis Maceroni was Peter Augustus Maceroni who, with two brothers, served in a French regiment in the American Revolution. After that conflict was ended he went to England and settled in Manchester, where he was Italian agent for British manufacturers. Francis Maceroni was educated in the Roman Catholic school, in Hampshire; at the Dominican Academy, in Surrey, and at the college at Old Hall Green, near Puckerbridge, Hertfordshire. During a period of ten years, from 1803 to 1813, he lived in Rome and Naples as a young gentleman of elegant leisure. In 1813 he began the study of anatomy and medicine, but had not gone far in those pursuits before his vagrom disposition took him in another direction. He became aide-de-camp to Murat, King of Naples, with the rank of Colonel of Cavalry. His service with Murat took him on missions to England and France, and for a time he was a prisoner of the French authorities. After two years of this military service, he returned to England, and retained his residence there for the rest of his life. He did not remain at home long, however, for he was with Sir George MacGregor at Porto Bello, in 1819; became a brigadier-general of the new republic of Colombia, and in 1821 saw service in Spain with General Pepe. Returning again to England, he came before the public as an advocate of a ship canal across the Isthmus, between the Atlantic and Pacific oceans, and also promoted a company, called The Atlantic and Pacific Junction and South American Mining and Trading Company, with a capital of one million pounds sterling. The company collapsed in the commercial panic of 1825, and this soldier of fortune in 1829 went to Constantinople to assist the Turks against the Russians. In London again in 1831, Maceroni was engaged for the rest of his life in the cause of highway steam locomotion, in which he accomplished a great deal. Maceroni was second only to Walter Hancock as an inventor and builder of steam road carriages and as a promoter of travel by those vehicles. From 1825 to 1828 he was with Goldsworthy Gurney in London, but his real activity did not begin until 1831, when he became associated with John Squire. In 1833, Maceroni and Squire took out a patent for a multi-tubular boiler, which they applied to a steam carriage that one writer of that day described as "a fine specimen of indomitable perseverance." It often traveled at the rate of from eighteen to twenty miles an hour. The engines were placed horizontally underneath the carriage body, the boiler was arranged at the back, and a fan was used to urge the combustion of the fuel, the supply of which was regulated by the engineman, who had a seat behind. The passengers were placed in the open carriage body, and their seats were upon the tops of the water tanks. There were two cylinders seven and one-half inches in diameter, the stroke being fifteen and three-quarter inches. The diameter of the steam pipe was two and one-quarter inches, and that of the exhaust pipe was two and three-quarter inches. The carriage attracted a great deal of attention, and much was written about it in the newspapers of the time. Once the trip was taken to Harrow-on-the-Hill, a distance of nine miles, in fifty-eight minutes, without the full power of steam being on at any time. For several weeks in the early part of 1834 the carriage was running daily from Oxford Street to Edgeware. Several trips were made to Uxbridge, when the roads were in very bad condition, but the journey from the Regent's Circus, Oxford Street, a distance of sixteen miles, was often performed in a little over an hour. A trip to Watford was made, and one of the passengers thus described the experience from Bushby Heath into the village of Watford: "We set off from the starting place amid the cheers of the villagers. The motion was so steady that we could have read with ease, and the noise was no worse than that produced by a common vehicle. On arriving at the summit of Clay Hill, the local and inexperienced attendant neglected to clog the wheel until it became impossible. We went thundering down the hill at the rate of thirty miles an hour. Mr. Squire was steersman, and never lost his presence of mind. It may be conceived what amazement a thing of this kind, flashing through the village of Bushy, occasioned among the inhabitants. The people seemed petrified on seeing a carriage without horses. In the busy and populous town of Watford the sensation was similar--the men gazed in speechless wonder; the women clapped their hands. We turned round at the end of the street in magnificent style, and ascended Clay Hill at the same rate as the stage coaches drawn by five horses." Maceroni made two steam carriages, but in 1834 he separated from Squire, and becoming short of funds fell into the clutches of Asda, an Italian Jew, who persuaded him to let the two carriages go to the Continent. One was sent to Brussels, where it ran successfully, and the other went to Paris. The performance of the latter was thus described in the columns of a Paris journal: "The steam carriage brought to perfection in England by Colonel Maceroni, ran along the Boulevards as far as the Rue Faubourg du Temple. It turned with the greatest facility, ran the whole length of the Boulevards back again, and along the Rue Royale, to the Place Louis XV. This carriage is very elegant, much lighter, and by no means so noisy as the one we saw here some months ago, and it excited along its way the surprise and applause of the astonished spectators. All the hills on the paved Boulevard were ascended with astonishing rapidity. One of our colleagues was in this carriage the whole of its running above described, and he declares that there is not the least heat felt inside from the fire, and that conversation can be kept up so as to be heard at a much lower tone than in most ordinary carriages." Asda sold the carriage and the patent for a large sum of money, and swindled Maceroni out of all his share. For years the inventor was in the direst extremes of poverty. In 1841 he succeeded in securing the support of The General Steam Carriage Company to construct and run carriages under his patent. Disagreement between the directors and the manufacturing engineer again brought to Maceroni disaster, from which he was never able to recover. RICHARD ROBERTS Born in 1789. Died in March, 1864. Roberts was best known as a Manchester, England, engineer, of the firm of Sharp, Roberts & Co. He built a steam road locomotive that was first tried in December, 1833. Three months later the machine was subjected to a second trial. The carriage went out under the guidance of Mr. Roberts, with forty passengers. It proceeded about a mile and a half, made a difficult turn where the road was narrow, and returned to the works without accident. The maximum speed on the level was nearly twenty miles an hour. Hills were mounted easily. No doubt existed of the engine being speedily put in complete and effective condition for actual service. During another experimental trip in April of the same year, the locomotive met with an accident caused by some of the boiler tubes giving way, allowing the steam to escape and the fuel to be scattered about. No one was seriously injured, and none of the passengers was hurt. Roberts invented the compensating gear that he first used on his steam carriage. This gear superseded claw clutches, friction bands, ratchet-wheels, and other arrangements for obtaining the full power of both the driving-wheels, and at the same time allowing for the engine to turn the sharpest corner. In 1839, Roberts invented an arrangement for communicating power to both driving-wheels at all times, whether turning to the right or left. During the latter years of his life this famous engineer lived in exceedingly straitened circumstances, and he died in poverty. JOHN SCOTT RUSSELL Born at Parkhead, near Glasgow, Scotland, May 8, 1808. Died June 8, 1882, at Ventnor. The father of John Scott Russell was David Russell, a Scottish clergyman, and the son was originally intended for the church. His mind was more inclined toward mechanics than theology, and he entered a workshop in order to learn the trade of engineering. Studying at the Universities of Edinburgh, St. Andrews and Glasgow, he was graduated from Glasgow when he was sixteen years of age. In 1832, upon the death of Sir John Leslie, Professor of Natural Philosophy at Edinburgh University, Russell was elected to fill the vacancy temporarily. Shortly after that he began his celebrated investigations into the nature of the sea waves, as a preliminary study to improving the forms of ships. As a result of these researches he developed the wave-line system for the construction of vessels. In 1837 he received a gold medal of the Royal Society of Engineers, and was elected a member of the Council of that Society for a paper that he read "on the laws by which water opposes resistance to the motion of floating bodies." At that time he was manager of the shipbuilding words at Greenock, and under his supervision and according to his designs several ships were built with lines based on his wave system. Among these were four of the new fleet of the West India Mail Company. Russell removed to London in 1844, and became a Fellow of the Royal Society in 1847. He was vice-president of the Institute of Civil Engineers and secretary of the Society of Arts. For many years he was a shipbuilder on the Thames, and supervised the construction of the celebrated steamship Great Eastern. He was one of the promoters and vice-president of the Institute of Naval Architects, and a pioneer in advocating the construction of iron-clad men-of-war. He published many papers, principally upon naval architecture. It was while he was residing in Edinburgh that he took out a patent for a steam locomotive to be used on the common roads. The boiler that he invented was multi-tubular, with the furnace and the return tubes on the same level, and similar to a marine boiler. The boiler everywhere consisted of opposite and parallel surfaces, and these surfaces were connected by stays of small diameter. The copper plates of the boiler were only one-tenth of an inch thick. When put to actual test the weakness of the boiler thus constructed was fully demonstrated. The engine had two vertical cylinders, twelve inches in diameter and with twelve inches stroke. The engine was mounted upon laminated springs, arranged so that each spring in its flexure described, at a particular point, such a circle as was also described by the main axle in its motion round the crank shaft. This arrangement was intended to correct any irregularities in the road so that they would not interfere with the proper working of the spur gearing. Exhaust steam was turned into the chimney to create a blast. Water and coke were carried on a separate tender on two wheels, coupled to the rear of the engine. Spare tenders, filled, were kept in readiness at different stations on the road. These tenders, mounted upon springs, had seats back and front for passengers. To work the locomotive three persons were required, a steersman on the front seat, an engineer on the back seat outside above the engines, and a fireman stationed on the footplate in front of the boiler. On the order of the Steam Carriage Company, of Scotland, six of these coaches were built by the Grove House Engine Works, of Edinburgh. They were substantially constructed and very elaborately fitted up. As was said at the time, they were "in the style and with all the comfort and elegance of the most costly gentleman's carriage." They ran very successfully for some time, during 1834, between St. George's Square, Glasgow, and Paisley. There was a service of six coaches once an hour. Each carriage accommodated six passengers inside and twenty outside, and sometimes drew, in addition, a dogcart laden with six passengers, and the necessary fuel and water. These dogcarts were used as relays on the road, being kept ready constantly. Public opposition to these coaches developed here as it had done in London about the same period. Road trustees objected to them on the ground that they wore out the roads too rapidly. Obstructions of stones, logs of wood, and other things were placed in their way, but the coaches generally went on in spite of these. Ordinary horse-drawn road carriages were more damaged and hindered than the Russell coaches, and even heavy carts were compelled to abandon travel on the obstructed roads and take roundabout courses, greatly to the discomfiture of the drivers. One day, however, a heavy strain, unusually severe, caused by jolting over the rough road, broke a wheel, and the weight of the coach falling on the boiler caused an explosion. Five persons were killed, and as a result of this accident the Court of Session interdicted the further travel of these carriages in Scotland. The Steam Carriage Company brought an action for damages against the trustees of the turnpike road for having compelled them to withdraw the carriages from the Glasgow and Paisley road by "wantonly, wrongfully and maliciously accumulating masses of metal, stones and rubbish on the said road, in order to create such annoyance and obstruction as might impede, overturn, or destroy the steam coaches belonging to the plaintiffs," but nothing seems to have come of this action. No longer used in Scotland, two of Russell's coaches were sent to London. There they were engaged in running with passengers between London and Greenwich, or Kew Bridge. Several trips were made to Windsor. After about a year they were offered for sale, and, on exhibition preparatory to sale, they started every day from Hyde Park Corner to make a journey to Hammersmith. But they remained unsold, and were shortly forgotten. Had conditions been more encouraging Russell might have achieved as great success in his land as in his water vehicles. He was a man of rare scientific attainments, and his work in ship designing and building put him in the front rank of naval architects and builders of his day. In addition to his work, already mentioned, he built a big steamer to transport railway trains across Lake Constance. W. H. CHURCH A physician of Birmingham, England, Dr. W. H. Church gave many years to the study of steam locomotion. Several patents were secured by him between 1832 and 1835, and in the latter year a common road carriage, built according to his plans, was brought out. The Church vehicle had a framework of united iron plates or bars, bolted on each side of the woodwork to obtain strength. Well trussed and braced, this framework enclosed a space between a hind and fore body of the carriage, and of the same height as the latter, and contained the engine, boiler, and other machinery. The boiler consisted of a series of vertical tubes, placed side by side, through each of which a pipe passed, and was secured at the bottom of the boiler tube; the interior pipe constituted the flue, which first passed in through a boiler tube, and was then bent like a syphon, and passed down another until it reached as low or lower than the bottom of the fireplace, whence it passed off into a general flue in communication with an exhausting apparatus. Two fans were employed, one to blow in air, and the other to draw it out; they were worked by straps from the crank shaft. The wheels of the carriage were constructed with the view to rendering them elastic, to a certain degree, in two different ways: First, the felloes were made of several successive layers of broad wooden hoops, covered with a thin iron tire, having lateral straps to bind the hoops together; second, these binding straps were connected by hinge joints to a kind of flat steel springs, somewhat curved, which formed the spokes of the wheels. These spring spokes were intended to obviate the necessity, in a great measure, of the ordinary springs, and the elasticity of the periphery was designed so that the yielding of the circle should prevent the wheel from turning without propelling. Church also proposed, in addition to spring felloes, spring spokes, and the ordinary springs, to employ air springs, and for that purpose provided two or more cylinders, made fast to the body of the carriage, in a vertical position, closed at top, and furnished with a piston, with packing similar to the cap-leather packing of the hydraulic press. This piston was kept covered with oil, to preserve it in good order, and a piston rod connected it with the supporting frame of the carriage. Motion was communicated by two oscillating steam cylinders suspended on the steam and exhaust pipes over the crank shaft. The crank shaft and driving-wheel axle were connected by means of chains passing about pitched pulleys. To introduce the Church coach, the London and Birmingham Steam Carriage Company was organized. The first carriage built for the company was an imposing vehicle, something like a big circus van, elaborately ornamented and with a large spheroidal wheel in front. It carried about forty passengers on top, in omnibus fashion, and the driver sat on a raised seat near the roof. A fair rate of speed was maintained, fifteen miles on the level, but the boiler was damaged, and horses hauled the engine back to the factory. Other carriages were subsequently brought out, but they all failed to meet the requirements of travel on the rough roads that existed at that time in England. JEAN JOSEPH ETIENNE LENOIR Born at Mussy-la-Ville, Luxembourg, January 12, 1822. Died, July, 1900, at La Varnne Chemevieves, near Paris. When Lenoir came to Paris in 1838 he had but an ordinary education and was without resources. For a time he served as a waiter in order to earn money to become an enameler and decorator. In 1847, he invented a new white enamel and four years after invented a galvano plastic process for raised work. Many other inventions were made by him, among them being an electric motor in 1856, a water meter in 1857, an automatic regulator for dynamos, the well-known gas motor that bears his name, and a system of autographic telegraphing. It is claimed that in September, 1863, Lenoir put a gas engine of his non-compressor type, of one and a half horse-power, on wheels and made an experimental run to Joinville-le-Paris and back. The motor, running at one hundred revolutions, it is said, took them there in one and a half hours. He thereupon abandoned such trials, and tried his engines in a boat, and in 1865 put a six horse-power in one, but the insignificant speed possible with his engine caused him to abandon that also. The Academy of Science of Paris decorated M. Lenoir and the Society of Encouragement gave him the grand prize of Argenteuil, amounting to twelve thousand francs. For his patriotic services at the siege of Paris, during the Franco-Prussian war, he was made a naturalized Frenchman. In 1880, he published in Paris a work treating of his researches into the tanning of leather. AMEDÈE BOLLÈE In April, 1873, Amedèe Bollèe, of Le Mans, France, the noted French engineer, filed a patent for a steam road vehicle and two years later he built the steam stage that he named Obeissante. Toward the end of that year this stage was run in and about Paris, where it created something of a sensation. It was even chronicled in the songs of the day and was made a topic of amusement at the variety theatres. This steam omnibus made twenty-eight kilometers in an hour. It is claimed to have been the first creation of the man to whose family much credit is due for the modern French automobile. Between 1873 and 1875, Bollèe made several carriages. In 1876, he worked with Dalifol and made a tram-car that would carry fifty passengers. This vehicle was put into the steam omnibus service in Rouen. Two years later he made another steam omnibus that he called La Mancelle. This vehicle, in June of that year, was run from Paris to Vienna and developed a speed on level roads of twenty-two miles an hour. In Vienna this vehicle was the subject of much talk and was largely caricatured. In 1880, Bollèe built another omnibus, La Nouvelle. This vehicle was entered in the Paris-Bordeaux competition in 1895, and was the only steam carriage that covered the course in that race. Bollèe has been a conspicuous exponent of the steam carriage in France from the time he commenced as far back as 1873. The vehicles that he has built were in many instances pioneers in their class, and have been exceedingly serviceable and successful. They have made the name of Bollèe notable. GEORGE B. SELDEN Born in the fifties, George B. Selden came of a family of jurists, whose ancestors were early Connecticut settlers. Among them were several eminent scientific men. His father, Henry Rogers Selden, was born in Lyme, Conn., October 14, 1805, and died in Rochester, N. Y., September 18, 1885; was Judge of the Supreme Court of the State of New York, and is still remembered by men of that generation as one of the most accomplished lawyers and jurists who occupied that bench in the last century. George B. Selden attended Yale University, and while equipping himself for his legal career, following in the footsteps of his father, indulged his natural predilection for scientific work. While practicing law in Rochester, N. Y., he devoted much time to the problem of self-propelled vehicles on common roads, in which, as early as the sixties, he was then interested. The study of this art led to a very full analysis of the possibilities of different means of propulsion, with, as a result, the conclusion that the light, liquid hydro-carbon concussion engine must eventually fill the exacting requirements of road vehicles. His further experimenting that was carried on during the seventies, and the actual constructing, so convinced him in his deductions that the record is found in the United States Patent Office of his filing an application for patent in May, 1879, with a Patent Office model of his gasoline vehicle. For more details, reference must be made to his patent, No. 549160, subsequently issued in November, 1895. Thereafter in a general report treating of important and leading inventions in various fields this was referred to by the Commissioner of Patents as the pioneer patent in its class. Of Selden's voluminous and persistent work and his many engines and models more detailed information cannot be here given. His fundamental patent at present is involved in extensive litigation, although it is recognized by manufacturers of gasoline vehicles who, to-day, are producing from eighty to ninety per cent of the output of the United States. Of his work along the lines of improvements in details of his main invention, the gasoline automobile _per se_, and kindred matters all of which have or will have a great bearing upon automobile construction and operation, it is not at this time possible to dwell at length. Selden is known as an exceedingly able attorney in his specialty, while his active connection with the extensive reaper and binder litigation, in all of which he appeared prominently, established for him an enviable reputation. Those who have had the privilege of a closer personal acquaintance know of his great fund of scientific knowledge in various arts, as well as his most interesting accumulations of data as a result of his personal researches. Selden is a patentee in other fields beside that of the gasoline automobile and his achievements have been numerous and of exceeding importance. He is also a chemist of more than ordinary ability and has applied himself as a close student to this line of scientific investigation. As a result he has made notable discoveries that, although not yet given to the world, will, it is confidently believed by those acquainted with them, prove to be of the greatest scientific value. SIEGFRIED MARCUS Marcus was an ingenious mechanic. In early life he made dental instruments and apparatus for a magician in Vienna. For his construction of a thermopile he received a prize and to his further credit as an inventor are placed an arc lamp, Rhumkoff coil carbureter, a high candle-power petroleum lamp, magneto-electro machines, a microphone and various other things in many branches of science. [Illustration: SIEGFRIED MARCUS] It is claimed that about the middle seventies of the last century he carried on experiments with a gas engine that had a spring-connected piston rod. He mounted this vertically on an ordinary horse vehicle and connected it directly with a cranked rear axle, carrying two flywheels in place of the regular road wheels. He is said to have made trials of this vehicle at night in Vienna. If this was so he was apparently trying to keep his plan secret and succeeded very well. Aside from general references nothing of importance revealed itself concerning this vehicle and Marcus' experiments with it, until very recently when interest in the historic development of the automobile has stimulated anew investigation into the endeavors of the early inventors. In 1882 the motor work of Marcus was principally preparatory to his new engine construction. It included experimenting with an Otto engine run with petroleum and a vaporizer and electric ignition with magneto. In 1883 he constructed a closed or two-cycled motor and thereafter had engines made in Budapest and elsewhere. One of these motors he put on wheels, but this was abandoned for other ideas that came from his fertile mind. CARL BENZ Born, November 26, 1844, at Karlsruhe, Baden, Germany. The early education of Carl Benz was acquired at the Lyceum until his seventeenth year and then at the Technical High School of his native city for four more years. This was followed by three years of practical work in the shops of the Karlsruhe Machine Works. When he was twenty-eight years of age, in 1872, after further experience in Mannheim, Pforzheim and Vienna, he opened workshops of his own in Mannheim. In 1880 he began to commercialize a two-cycle stationary engine. In 1883 he organized his business as Benz & Co., and produced his first vehicle in 1884. In the beginning of 1885 his three-wheeled vehicle ran through the streets of Mannheim, Germany, attracting much attention with its noisy exhaust. This was the subject of his patent dated January 29, 1886, claimed by him to be the first German patent on a light oil motor vehicle. This embodied a horizontal flywheel belt transmission through a differential and two chains to the wheels; but it is noteworthy primarily as having embodied a four-cycle, water jacketed, three-quarter horse-power engine, with electric ignition. In 1888, the Benz Company exhibited their vehicles at the Munich Exposition, where they attracted wide attention. This was followed by the exhibition at the Paris show in 1889, by the engineer Roger, of another vehicle made under license that Roger had acquired from Benz and constructed by Panhard and Levassor. [Illustration: CARL BENZ] While in 1899 the firm was converted into a stock company of three million marks capital, and then employed three hundred men, Carl Benz remained the leading spirit of the concern, technically, while the commercial work came under the direction of Julius Ganz. The able co-operation of these two has established the world-famous automobile enterprise looked upon by many as the pioneer producing works of its kind in Germany. Of late years motor boats have also been made by them, but their automobiles and those of their affiliated companies or licensees in other countries still stand in the first rank. GOTTLIEB DAIMLER Born at Schorndorf, Wurtemburg, March 17, 1834. Died at Cannstadt, near Stuttgart, March 6, 1899. After receiving a technical and scientific training at the Polytechnic School at Stuttgart, 1852-59, Daimler spent two years, 1861-63, as an engineer in the Karlsruhe Machine Works, becoming foreman there. In 1872 he entered the Gas Engine Works at Deutz, near Cologne, and became director of that establishment. Within ten years that shop, better known as the Otto Engine Works, grew from a small place into a large, well-organized and famous establishment. In 1882 he removed to Cannstadt to give his entire attention to the light-weight internal-combustion auto motor, with which his career was so completely identified, and the successful application of which earned for him the title, "the father of the automobile," in Germany, though that is, in fact, contested by those familiar with the work of Benz. Instead of using the uncertain-acting flame with the inconvenient speed limitations, Daimler invented and introduced in 1883 the so-called hot-tube ignition. This consisted of a metal or porcelain tube attached to the compression space of the cylinder in such a manner that the interior of the tube was in continual communication with the compression space. A gas flame, continually burning under the tube, maintained it at a glowing red heat, so that the mixed charge of air and gas, when compressed into the tube, became fully and effectively ignited. Experience showed that by a proper regulation of the temperature of the hot tube the ignition could be made to take place at any desired point in the compression, and thus the complicated, slow and uncertain slide flame ignition was replaced by a simple device, without moving parts, altogether satisfactory and reliable. The especial feature of the hot-tube ignition, however, was soon found to be the increased speed which it permitted. By its use the rotative speed could be increased eight to ten times over the older motor, and hence the weight could be reduced in nearly the same proportion. [Illustration: GOTTLIEB DAIMLER] This fact at once showed Daimler that the application of the internal-combustion motor to mechanically propelled vehicles had become a possibility, and that, with the use of hydro-carbon vapor as fuel, and the high-speed hot-tube motor, the petroleum automobile might become a practical possibility. He therefore severed his connection with the Otto Engine Works at Deutz, and returning to Cannstadt, near Stuttgart, his early home, he devoted his entire time and attention to the design of a light petroleum motor and motor vehicle. The result was the production, in 1885, of a motor-bicycle, in which the motor was placed directly under the seat, between the legs of the rider. The petroleum was drawn from a tank, the supply being regulated by the valve. The motor was first set in motion by lighting a lamp and turning the crank a few times, the discharge passing through the chamber into an exhaust-pipe. After the motor had been fully started, the vehicle was set in motion by moving a lever, which drew a tightening pulley against the belt, and so caused the power to be transmitted from the shaft pulley to the wheel pulley. Changes of speed were attained by using pulleys of different sizes, similar to the cone pulleys on a lathe. This machine was put into successful action at Cannstadt on November 10, 1885. An interesting feature in connection with the Daimler motor is the arrangement of the cooling-water circulation for the cylinder jacket. The water is contained in a tank, from which it is circulated in the cylinder jacket by means of a small rotary pump. From the jacket it passes to the cooler. This consists of a system of several hundred small tubes over which a blast of air is driven by a fan operated from the motor shaft. Since the speed of the fan increases with the speed of the motor, the cooling is proportional to the production of heat in the cylinder. In addition to gas, which is applicable for stationary motors only, the fuel may be benzine of a specific gravity of sixty-eight or seventy one-hundredths, or ordinary lamp petroleum. The consumption varies according to the size of the motor, ranging from thirty-six to forty-five one-hundredths kilograms per horse-power hour for vehicles, or somewhat less for boats. He adapted these light motors to vehicles of many styles, and his persistent work in this connection has made the world-wide reputation of the Daimler Motoren Gesellschaft, now flourishing at Cannstadt, Germany. In 1888-89 the French interest in the light motors led to their adoption by Panhard and Levassor. The type then developed and known as Phenix motors, were soon copied in part at least by many other French makers, resulting in a modified form there known as the Pygmée. Work at Cannstadt progressed steadily, however, and many pleasure vehicles were made as well as small boats. The able assistance of William Maybach brought further credit to the company, particularly in view of the aspirating carbureter which, with such details as clutch and transmission mechanism, helped to perfect the Cannstadt automobiles. In the latter nineties the prominence of the Daimler Works as vehicle makers, distinguished from motor makers, again began to be noticed and soon their now famous Mercedes cars appeared. In recent years these machines have made remarkable records in races and all other branches of the sport. With a magnificent refinement of details in construction they are to-day looked upon as the pleasure vehicles _par excellence_. They have had a large vogue in all parts of Europe and are accepted there as among the most satisfactory vehicles in their class that are now made. Many of them have been brought to the United States, where they have been and still are in great demand. LEVASSOR Born at Marolles, in Hurepoix (Seine and Oise), January 21, 1843. Died, April 14, 1897. Levassor was graduated from the Central School of Arts and Manufactures, Paris, in 1864. He was employed as an engineer at the Cockerill Works at Seriang, Belgium, and also with Durenne at Courbevoie, near Paris. In 1872 he entered the firm of Perrin & Panhard, the name of the concern being changed to Perrin, Panhard & Co. Upon the death of M. Perrin, he became the junior partner and the name of Panhard & Levassor was adopted. When Levassor died in 1897, the corporation of Panhard & Levassor was formed. [Illustration: LEVASSOR] Levassor made many improvements in the machinery and output of Panhard & Levassor. Especially he perfected machines for wood-working and made important changes in the processes used for the cold cutting of hard metals. On the first appearance of gas motors he undertook their construction in France. It was in the establishment of Panhard & Levassor that the first motors were constructed under the system of Otto and Langen with atmospheric pressure, then the four-cycle engine of Otto and finally the two-cycle system of Benz and Ravell. In 1886, when the Daimler petroleum motor appeared, he recognized the great part that it would play in practical application to the propulsion of vehicles and boats. He acquired the right to use it in France, and in 1887 exhibited, in Paris, a boat thus propelled. After several years he put forth the first automobile vehicle with motor in front. LEON SERPOLLET Serpollet is noted in France to-day as the champion of the steam automobile. In 1887, he appeared in Paris with his three-wheeler, two rear drive and one front steering wheel. With its light and safe generator his machine attracted much attention, but its use in the streets of the capital was temporarily prohibited, until the granting to him in 1891 of the first unrestricted license for such use resulted from his initiation of the prefect of police by driving that important personage in the steamer. His generator, known as the "flash boiler," has been developed to a high state of perfection. The tubes of his boiler were heavy, flattened tubing, strengthened in that form by being transversally bent or grooved. He was helped doubtless to no small extent, in his work, by his association, about 1897, with a wealthy American, F. L. Gardner, who made possible the development of the large Gardner-Serpollet establishment in the Rue Stendhal, Paris. While Serpollet has achieved a brilliant and well-deserved reputation in his native land, he is also recognized in other countries as one of the greatest living promoters of the steam branch of the automobile industry. His adherence to steam as the motive power in self-propelled road vehicles has been unremitting and energetic. Few men have done more than he to improve carriages in this class. In 1900, Serpollet was made a Chevalier of the Legion of Honor. His sales to that date of five machines for the Shah of Persia and landaulets for the Maharajah of Mysore and other notables had given him much prominence at that time. [Illustration: LEON SERPOLLET] LOUIS AND MARCEL RENAULT Born in Boulogne, France, the Renault Brothers, with general technical education, perseverance and ability, entered the field of automobile manufacturing only some six years ago, although they earlier gave to the subject much attention and study. Having appreciated through personal experience the shortcomings of the gasoline tricycle, Louis Renault in October, 1898, manufactured, in his private shop, a small two-passenger vehicle, with a one and three-quarters horse-power motor, which eliminated the pedalling for starting, but was otherwise small and light as a tricycle. In January, 1899, he brought out a small four-wheeler with one and three-quarters horse-power motor in front, three speeds and chainless, or as now called propeller drive. The demand was immediate and large and resulted in the establishment of the works of Renault Frères, who began to make the first lot of these small vehicles in March of the same year. These won prizes in the Paris-Trouville, the Ostende and the Rambouillet runs, and one completed a three thousand six hundred kilometer tour through different parts of Europe and over the Alps. The new model of 1900 had a three and one-half horse-power motor and thermo-syphon cooling system. Many honors were won with these, and notably that of Louis Renault's most successful use of one in the grand army maneuvers. But the output of three hundred and fifty showed the necessity for larger works. With the increased facilities of 1901, the product was doubled and the model increased to four and one-half horse-power, while eight and nine horse-power were winners in the Paris-Bordeaux and Paris-Berlin races. In 1902 came another addition to the Billancourt works of Cloise to four thousand square meters area, and the Renault Brothers then changed their models to voiture légère, six to eight horse-power, steel tube frame and wood wheels--a full-fledged vehicle. They succeeded in the Circuit du Nord, organized by the Minister of Agriculture, for alcohol-motored vehicles. Then came the triumph of their twenty horse-power four-cylinder type in the great Paris-Vienna race, where it was pitted against forty and even seventy horse-power vehicles. The result was a great impetus commercially, and new shops accommodating a thousand workmen and covering thirteen thousand square meters, which produced one thousand four hundred vehicles in the following year. Both brothers, who had always been at the wheel of their own cars in the years of racing, entered the memorable "race-of-death," Paris-Madrid, in May, 1903. Louis arrived first at Bordeaux, but his unfortunate brother Marcel, while close to victory, was killed with the overturning of his machine only a few kilometers from the goal. In memory of Marcel Renault a simple monument was unveiled at Billancourt May 26, 1904, on ground contributed by the municipal council; a bronze plate on one side of this perpetuates his triumphant entry into Vienna, showing his arrival at the finish. Louis Renault, since continuing the business, has now produced larger machines, including the sixty to ninety horse-power made for the Vanderbilt race in America, October, 1904. [Illustration: MARCEL RENAULT] NOTED INVESTIGATORS SIMON STEVIN, THOMAS WILDGOSSE, DAVID RAMSEY, JOHANN HAUTSCH, CHRISTIAAN HUYGENS, STEPHEN FARFLEUR, FERNANDO VERBIEST, ISAAC NEWTON, VEGELIUS, ELIÉ RICHARD, GOTTFRIED WILHELM VON LEIBNITZ, HUMPHREY MACKWORTH, DENIS PAPIN, VAUCAUSON, ROBINSON, ERASMUS DARWIN, RICHARD LOVELL EDGEWORTH, FRANCIS MOORE, PLANTA, J. S. KESTLER, BLANCHARD, THOMAS CHARLES AUGUSTE DALLERY, JAMES WATT, ROBERT FOURNESS, GEORGE MEDHURST, ANDREW VIVIAN, DU QUET, J. H. GENEVOIS, JOHN DUMBELL, WILLIAM BRUNTON, THOMAS TINDALL, JOHN BAYNES, JULIUS GRIFFITHS, EDMUND CARTWRIGHT, T. BURTSALL, T. W. PARKER, GEORGE POCOCK, SAMUEL BROWN, JAMES NEVILLE, T. S. HOLLAND, JAMES NASMYTH, F. ANDREWS, HARLAND, PECQUEUR, JAMES VINEY, CHEVALIER BORDINO, CLIVE, SUMMERS AND OGLE, GIBBS, CHARLES DANCE, JOSHUA FIELD, DIETZ, YATES, G. MILLICHAP, JAMES CALEB ANDERSON, ROBERT DAVIDSON, W. G. HEATON, F. HILL, GOODMAN, NORRGBER, J. K. FISHER, R. W. THOMPSON, ANTHONY BERNHARD, BATTIN, RICHARD DUDGEON, LOUGH AND MESSENGER, THOMAS RICKETT, DANIEL ADAMSON, STIRLING, W. O. CARRETT, RICHARD TANGYE, T. W. COWAN, CHARLES T. HAYBALL, ISAAC W. BOULTON, ARMSTRONG, PIERRE RAVEL, L. T. PYOTT, A. RICHTER, RAFFARD, CHARLES JEANTEAUD, SYLVESTER HAYWOOD ROPER, COPELAND, G. BOUTON, COUNT A. DE DION, ARMAND PEUGEOT, RADCLIFFE WARD, MORS, MAGNUS VOLK, BUTLER, LE BLANT, EMILE DELAHAYE, ROGER, GEORGES RICHARD, POCHAIN, LOUIS KRIEGER, DE DETRICH, DAVID SALOMONS, LEON BOLLÈE, JOSEPH GUEDON, RENE DE KNYFF, ADOLF CLEMENT, A. DARRACQ, JAMES GORDON BENNETT. SIMON STEVIN Born in Bruges, Holland, in 1548. Died in 1620. Stevin was a noted mathematician, and also experimented in the construction of wheel vehicles about 1600. He built in his workshop at The Hague a wheeled vehicle that was propelled by sails. This was simply a tray or boat of wood, which hung close to the ground. It was borne on four wooden wheels, each one of which was five feet in diameter, and the after-axle was pivoted to form a rudder. A tall mast was carried amidships, and there was a small foremast that was stayed aft. Large square sails were carried on these masts. A trial trip of this sailing ship on land was made in 1600, when the journey from Scheveningen to Petten, a distance of forty-two miles, was made in about two hours. On this occasion some twenty-two passengers were carried. Prince Maurice of Holland steered, and among the passengers were Grotius, and the Spanish Admiral, Mendoza, who was then a prisoner of war in Holland. Stevin also built a smaller sail vehicle, similar to the one just described, that carried from five to eight persons. Both carriages were used a great deal, running many miles on the Dutch coast. The smaller one was to be seen at Scheveningen as late as 1802. Grotius wrote a poem on these carriages. Bishop Wilkens, in England, also wrote about them in 1648, and showed a drawing that was made from a description given to him by those who had seen the car at work. Howell, a writer of the period, thus quaintly described the Stevin carriage: "This engine, that hath wheels and sails, will hold above twenty people, and goes with the wind, being drawn or moved by nothing else, and will run, the wind being good and the sails hois'd up, about fifteen miles an hour upon the even hard sands." THOMAS WILDGOSSE In 1618, Thomas Wildgosse got out a patent for "newe, apte, of compendious formes or kinds of engines or instruments to ploughe grounds without horse or oxen; and to make boates for the carryage of burthens and passengers runn upon the water as swifte in calmes, and more safe in stormes, than boats full sayled in great wynnes." It is agreed by the best authorities that these vehicles were set in motion by gear worked by the hand of a driver, although Fletcher thinks that steam engines were intended. Additional patents were granted to Wildgosse in 1625. DAVID RAMSEY Associated with Thomas Wildgosse in his experimenting and patenting, in 1618, was David Ramsey, who at that time was Page of the Bed Chamber to James I. of England, and afterwards was Groom of the Privy Chamber to the same monarch. In 1644, Ramsey was again a partner in the grant of a patent for "a farre more easie and better waye for soweing of corne and grayne, and alsoe for the carrying of coaches, carts, drayes, and other things goeing on wheels, than ever yet was used and discovered." This may have been a manually or a steam propelled vehicle. It is most reasonable to suppose that it was the former. JOHANN HAUTSCH Born in 1595. Died in 1670. Hautsch was a noted mathematician, and, experimenting in the construction of road vehicles, he built a mechanical carriage for use on common roads. This carriage was successfully run in Nuremberg, Germany, in 1649, and thereafter attracted a great deal of attention. It was propelled by a train of gears that turned the axle, being operated by two men who, secreted in the interior of the body, worked cranks. The finish of the body of this coach was very elaborate, being heavily carved and having fashioned in front the figure of a dragon, arranged to roll its eyes and spout steam and water, in order to terrify the populace and clear the way. On each side of the body were carved angels holding trumpets, which were constantly blown, the precursors, perhaps, of the automobile horns of to-day. The Hautsch coach was said to have gone as rapidly as one thousand paces an hour. One of the carriages which he built was sold to the Crown Prince of Sweden, and another to the King of Denmark. Not much more is known of the Hautsch vehicles, but it is a matter of record that the inventor was preceded by one whose name is unknown, but who ran a coach, mechanically propelled somewhat like this car, in January, 1447, near Nuremberg. CHRISTIAAN HUYGENS Born at The Hague, Holland, April 14, 1629. Died at The Hague, June 8, 1695. Huygens received a good education, and at early age showed a singular aptitude for mathematics. Soon after he was sixteen years of age he prepared papers on mathematical subjects that gave him pre-eminent distinction. He became noted as a physicist, astronomer and mathematician. He devoted some time to the consideration of improvements in road vehicular travel. STEPHEN FARFLUER Born in 1663. Farfluer was a contemporary of Johann Hautsch, and was a skillful mechanician of Altderfanar, Nuremberg, Germany. About 1650 he made a dirigible vehicle propelled by man power, but as distinguished from that of his rival, Hautsch, this was a small carriage, being calculated only for one person. Being crippled, Farfluer used the wagon as his only means of getting about alone. It had hand cranks that drove the single front wheel by gears. FERNANDO VERBIEST Born near Courtrai, Belgium, 1623. Died in China in 1688. Verbiest became a Jesuit missionary, and was a man of marked ability. After going to China he acquired a thorough knowledge of the language of that country, where he spent the greater part of his life. Under his Chinese name he wrote scientific and theological works in Chinese. He was appointed astronomer at the Pekin observatory, undertook the reformation of the Chinese calendar, superintended the cannon foundries, and was a great favorite of the Emperor. About 1655 he made a small model of a steam carriage. This is described in the English edition of Huc's Christianity in China, in Muirhead's Life of James Watt, and in the Astronomia Europia, a work that is attributed to Verbiest, but was probably compiled from his works by another Jesuit priest and was published in Europe in 1689. The Verbiest model was for a four-wheeled carriage, on which an aeolipile was mounted with a pan of burning coals beneath it. A jet of steam from the aeolipile impinged upon the vanes of a wheel on a vertical axle, the lower end of the spindle being geared to the front axle. An additional wheel, larger than the supporting wheels, was mounted on an adjustable arm in a manner to adapt the vehicle to moving in a circular path. Another orifice in the aeolipile was fitted with a reed, so that the steam going through it imitated the song of a bird. ISAAC NEWTON Born at Woolsthorpe, Lincolnshire, England, December 25, 1642. Died at Kensington, March 20, 1727. Isaac Newton, who became one of the greatest mathematicians that the world ever knew, was the son of a farmer. He was educated at Trinity College, Cambridge, and in his early youth he mastered the principles of mathematics, as then known, and began original investigations to discover new methods. His great achievement was the discovery of the law of universal gravitation, but his genius was active in other directions, as the investigation of the nature of light, the construction of improved telescopes, and so on. He was a Member of Parliament in 1689 and 1701, and master of the mint, a lucrative position, from 1696 until the time of his death. In 1671 he was elected a member of the Royal Society, and was annually chosen to be its president, from 1703 until his death. Newton was one of the first Englishmen to conceive the idea of the propulsion of vehicles by the power of steam. Taking up for consideration Hero's hollow ball filled with water from which steam was generated by the outward application of heat, he added these conclusions: "We have a more sensible effect of the elasticity of vapors if the hole be made bigger and stopped, and then the ball be laid upon the fire till the water boils violently; after this, if the ball be set upon little wheels, so as to move easily upon a horizontal plane, and the hole be opened, the vapors will rush out violently one way, and the wheels and the ball at the same time will be carried the contrary way." Beyond this philosophical suggestion, however, Newton never went. The steam carriage attributed to him by some writers is merely an imaginative creation, by writer or artist, based upon the above proposition. VEGELIUS A professor at Jena, Saxony, in the seventeenth century, Vegelius constructed, in 1679, a mechanical horse, which was propelled by springs and cased in the skin of a real horse. This machine is said to have traveled four German miles an hour. ELIÉ RICHARD Born on the Island of Ré in 1645. A physician of La Rochelle, France, Elié Richard was a man of science, and a considerable celebrity in his day. He had built, in 1690, a dirigible vehicle that he used to travel about in on his professional work. The carriage was propelled by mechanism operated by a man-servant by means of a treadle. The operator was placed on the rear of the carriage, and the occupant, seated in front, steered by a winch attached to a small wheel. This construction was frequently referred to by contemporaries of Richard, and even later on, and was copied by others during the following hundred years or so. GOTTFRIED WILHELM VON LEIBNITZ Born at Leipsic, Germany, July 6, 1646. Died at Hanover, November 14, 1716. Leibnitz, in addition to his work as a philosopher and mathematician, was also interested in mechanics. He gave some attention to the study of the possibility of making improvements in common road vehicles, and he endeavored to encourage, though without results, his contemporary, Denis Papin. HUMPHREY MACKWORTH Born in 1647. Died in 1727. A celebrated English politician and capitalist, Sir Humphrey Mackworth matriculated at Magdalene College, Oxford, December 11, 1674. He was entered at the Middle Temple, in June, 1675, and called to the bar in 1682. In 1695 he was engaged in developing collieries and copper and smelting works at Melencryddan, near Neath, Wales, and the improvements introduced by him there were of the greatest value. Among other improvements he constructed a wagon-way from the mines, and propelled his coal-carrying cars by sails. DENIS PAPIN Born at Bloys, France, August 22, 1647. Died in England, 1712. Papin was a son and nephew of a physician. He studied medicine in Paris and practiced for some time, attaining distinction in his profession. A passion for the sciences, mathematics and physics drew him away from medical practice and he became skillful in other lines. He followed assiduously the footsteps of Huygens and in some respects became a rival of his master in original thought and experimenting and in professional attainments. Papin invented in 1698 a carriage that was fitted with a steam engine as such is now understood; that is, a cylinder and a piston. This was probably the first vehicle of its kind known in Europe. The construction was a model merely, a toy which ran around the room, but it is said to have worked well. Concerning this invention, Papin said: "I believe that one might use this invention for other things besides raising water. I have made a little model of a carriage that is propelled by this force. I have in mind what I can do, but I believe that the unevenness and turns of the highway will make this invention very difficult to perfect for carriages or road use." Although encouraged to prosecute his work by the Baron Gottfried Wilhelm von Leibnitz, his doubts could not be overcome in regard to the practicability of his proposed carriage. He still claimed, however, that by the aid of such vehicles, infantry could probably be moved as quickly as cavalry and without the necessity of heavy impedimenta of food and other supplies. VAUCAUSON A celebrated French mechanician, Vaucauson, in April, 1740, built a vehicle "to go without horses." He was visited at his palace in Rue Charonne, Paris, by King Louis Fifteenth, and the exhibition of this vehicle, which, according to reports, was propelled by a "simple watch spring," was reviewed in a journal of the time as follows: "Yesterday, at 3 P.M. His Majesty, accompanied by several officers and high court functionaries, repaired to the palace of M. Vaucauson and took his seat on a species of throne specially prepared for his reception on a raised platform, whence he could clearly discern all the mechanism of the carriage in its gyrations through the avenues and alleys. The vehicle would seat two persons, and was painted scarlet, bordered in blue, ornamented with much gilding; the axle trees of the wheels were provided with brakes and set in motion by a fifth wheel, likewise well braked and bound with long ribbons of indented steel. Two chains communicated with a revolving lever in the hands of the conductor, who could at will start or stop the carriage without need of horses. His Majesty congratulated the skillful mechanician, ordering from him for his own use a similar vehicle to grace the royal stables. The Duke of Montemar, the Baron of Avenac and the Count of Bauzun, who had witnessed the trial, were unable to credit their own vision, so marvelous did the invention appear to them. Nevertheless, several members of the French Academy united in declaring that such a piece of mechanism could never circulate freely through the streets of any city." Either from royal forgetfulness or thanks to the customary court intrigues to turn His Majesty from his purpose, or possibly because of the somewhat crude nature of the invention itself, the fact is that from that time forth not the slightest mention is to be found in history of the motor carriage of Vaucauson. ROBINSON It is on the authority of James Watt that Dr. Robinson is credited with having conceived the idea of driving carriages by steam power. Watt wrote as follows: "My attention was first directed to the subject of steam engines by the late Dr. Robinson, then a student in the University of Glasgow, afterwards Professor of Natural Philosophy in the University of Edinburgh. He, in 1759, threw out the idea of applying the power of the steam engine to the moving of wheel carriages, and to other purposes, but the scheme was soon abandoned on his going abroad." ERASMUS DARWIN Born at Elton, Nottinghamshire, England, December 12, 1731. Died at Derby, April 18, 1802. Having studied at St. John's College, Cambridge, and at Edinburgh, Darwin settled as a physician at Litchfield and gained a large practice. In 1781 he moved to Derby. He was a man of remarkable scientific attainments and a voluminous writer of poetry that was pervaded by enthusiasm and love of nature, but had little poetic quality. Darwin, wrote most of his poetry and evolved most of his ideas as he drove about the country in a doctor's covered sulky that was piled high with books and writing materials. He was in correspondence with Benjamin Franklin and Matthew Boulton about 1765 in regard to steam, and writing to Boulton, said: "As I was riding home yesterday I considered the scheme of the fiery chariot, and the longer I contemplated this favorite idea, the more practicable it appeared to me. I shall lay my thoughts before you, crude and undigested as they appeared to me, and by these hints you may be led into various trains of thinking upon this subject, and by that means (if any hints can assist your genius, which, without hints, is above all others I am acquainted with) be more likely to approve or disapprove. And as I am quite mad of the scheme, I hope you will not show this paper to anyone. These things are required: (1) a rotary motion; (2) easily altering its direction to any other direction; (3) to be accelerated, retarded, destroyed, revived, instantly and easily; (4) the bulk, the weight, the expense of the machine to be as small as possible in proportion to its weight." Darwin gave sketches and suggested that the steam carriage should have three or four wheels, and be driven by an engine having two cylinders open at the top, and the steam condensed in the bottom of the cylinder, on Newcomen's principle. The steam was to be admitted into the cylinders by cocks worked by the person in charge of the steering wheel, the injection cock being actuated by the engine. The "fiery chariot" never went beyond this suggestion, however. RICHARD LOVELL EDGEWORTH An English gentleman of fortune, and much interested in mechanics, Richard Lovell Edgeworth was influenced by Dr. Erasmus Darwin to take up the subject of steam locomotion. In 1768, Dr. Small, in correspondence with James Watt, spoke of Edgeworth and his experiments in the problem of moving land and water carriages by steam. Two years later Edgeworth patented a portable railway system and then spent nearly forty years on that one idea. When an old man of seventy, Edgeworth wrote to James Watt: "I have always thought that steam would become the universal lord, and that in time we should scorn the post horses." Dr. Smiles says: "Four years later he died, and left the problem which he had nearly all his life been trying ineffectually to solve, to be worked out by younger men." FRANCIS MOORE In 1769, Francis Moore, of London, a linen draper, invented a machine which he described as made of wood, iron, brass, copper, or other metals, and constructed upon peculiar principles, and capable of being wrought or put in motion by fire, water, or air, without being drawn by horses or any other beast or cattle; and which machines, or engines, upon repeated trials, he has discovered would be very useful in agriculture, carriage of persons and goods, either in coaches, chariots, chaises, carts, wagons, or other conveyances, and likewise in navigation, by causing ships, boats, barges, and other vessels to move, sail, or proceed, with more swiftness or despatch. It was said that, so confident was the inventor of the success of his machine, he sold all his own horses, and by his advice many of his friends did the same, expecting that the price of that animal would be so affected by the invention, that it would not be again one-fourth of what it was then. Moore made several trials with his steam carriage, and took out three patents for it. Like many others of that time, however, Moore's carriages never got into use. PLANTA A Swiss army officer who was contemporary with Cugnot in the seventeenth century. He was engaged upon the problem of a steam road wagon at about the same time that Cugnot conceived and executed his vehicle in 1769. General Gribeauval, to whom Cugnot's plan had been referred, engaged Planta to pass upon it and to examine the new vehicle. The Swiss officer found it in all respects so much better than his own that he so reported to the French Ministry of War and abandoned further endeavors on that line. J. S. KESTLER In 1680 a description was published of a carriage designed by J. S. Kestler. This was merely a toy, set in motion by mercury in a tube heated by a candle. BLANCHARD In connection with his partner, Masurier, Blanchard brought out in Paris, in 1779, a vehicle that was somewhat patterned after the man-propelled carriage of Elié Richard. It was very successful and attracted a great deal of attention. THOMAS CHARLES AUGUSTE DALLERY Born at Amiens, France, September 4, 1754. Died at Jouy, near Versailles, in June, 1835. About 1780, Dallery made a steam vehicle with a multi-tubular boiler which he claimed was an original invention of his own. This vehicle was run in Amiens and in 1790 was seen on the streets of Paris. In March, 1803, he secured a patent on the tubular boiler for use on his steamboat, or on his steam carriage. This vehicle was a boat-shaped wagon, driven by a steam engine. JAMES WATT Born at Greenock, Scotland, January 19, 1736. Died at Birmingham, Staffordshire, England, August 25, 1819. Watt came of a respectable and industrious family. His grandfather was a professor of mathematics, while his father was an instrument maker, councillor and manufacturer. After a limited education young Watt went to London, in 1755, and became a mathematical and nautical instrument maker. In that capacity he became connected with Glasgow University, and there made his discoveries that resulted in the practical improvements in the steam engine which made him famous. He was associated with Matthew Boulton, under the firm name of Boulton & Watt, from 1774 to 1800, and the Watt engines that were built by that concern at Soho revolutionized England's mining industries. His steam engines represented a great step beyond the Newcomen engines, though still using low-pressure steam. Watt's connection with steam carriages for use on the common roads, a subject that was of much moment in his day, was limited to a single patent and generally to discouraging the plans of others in that direction, owing to his fear that the introduction of high-pressure steam use would harm the engine business. In the patent granted to him in 1784 he proposed that the boiler of his carriage should be made of wooden staves, fastened with iron hoops, like a cask, and the furnace to be of iron, and placed in the inside of the boiler, surrounded with water. Watt, however, never built the steam carriage. He retained the deepest prejudices against the use of high-pressure steam, saying: "I soon relinquished the idea of constructing an engine on this principle; from being sensible it would be liable to some of the objections against Savery's engine, viz., the danger of bursting the boiler, and also that a great part of the power of the steam would be lost, because no vacuum was formed to assist the descent of the piston." ROBERT FOURNESS Born in Otley, Yorkshire, England. Died at an early age. Fourness became a practical engineer and invented several labor-saving machines. One of his first inventions was for a machine to split hides, that was set up and operated in the establishment of his father. Later in life he established works for himself in Sheffield, and afterwards in Gainsborough. In 1788, he was a resident of Elland, Halifax, and there made a steam carriage that was run by a three-cylinder inverted engine. Spur-gearing transmitted the driving power from the crank shaft to the axle. His patent was taken out in conjunction with James Ashworth. This vehicle was mounted on two driving wheels and had a smaller steering wheel in front. GEORGE MEDHURST Born at Shoreham, Kent, England, in February, 1759. Died in September, 1827. Medhurst was educated as a clock maker, but in 1789 started as an engineer. In the same year he secured a patent for a windmill and pumps for compressing air to obtain motive power. One of the first investigators in this direction, the idea on which he worked and which continued to absorb his energy throughout life, was to make use of the wind when it served in order to compress large bodies of air for use when needed. In 1800, he took out a patent on an aeolian engine and demonstrated how carriages could be driven upon the common roads by compressed air stored in reservoirs underneath the body of the vehicle. He also contemplated applying this engine to other useful purposes and calculated that small carriages could be worked by a rotary engine and larger ones by reciprocating engines with special gear for varying power. In describing his inventions and explaining his ideas regarding compressed air, Medhurst said: "The power applied to the machinery is compressed air, and the power to compress the air I obtain generally by wind, assisted and improved by machinery described in this specification, and in order to render my invention universally useful I propose to adapt my machinery and magazine so that it may be charged by hand, by a fall of water, by a vacuum obtained by wind and also by explosive and effervescent substances, for the rapid conveyance of passengers, mails, dispatches, artillery, military stores, etc., and to establish regular stage coaches and wagons throughout the kingdom, to convey goods and passengers, for public accommodation, by erecting windmills, water-mills, etc., at proper intervals upon the roads, to be employed in charging large magazines at these stations with compressed air, or in raising large magazines of water by wind, etc., by the power of which portable magazines may be charged when required by machinery for that purpose." Medhurst contemplated establishing regular lines of coaches, with pumping stations at regular stopping places. He endeavored to form a company to work his inventions and develop his plans and published a pamphlet on the subject of compressed air. About 1800, he established himself as a machinist and ironmaster in Denmark street, Soho, and about ten years later was the first to suggest pneumatic tubes for the carriage of parcels or passengers. Some two years later he brought out the proposition for what has come to be known as the atmospheric railway, an appliance for conveying goods and passengers by the power of a piston in a continuous tube laid between the rails. ANDREW VIVIAN A resident of Cornwall, England, Andrew Vivian, a cousin of Richard Trevithick, became much interested in the engineering experiments of his famous relative. He worked with his cousin and particularly assisted him in experiments on steam engines for propelling road carriages. In 1802, he was a joint patentee with Trevithick, in the early steam vehicle that was taken to London and was exhibited in that city, where for a short time it occasioned a great deal of public curiosity. DU QUET A Frenchman who, in 1714, designed a small windmill to give motion to the wheels of his carriages. J. H. GENEVOIS A Swiss clergyman, of the early part of the eighteenth century. He proposed to use windmills or sails on his wagon and by a system of springs to store the energy thus obtained until such time as it should be needed for driving purposes. JOHN DUMBELL In 1808, John Dumbell secured a patent for an engine that had many peculiar features. He planned to have the steam act on a series of vanes, or fliers, within a cylinder, "like the sails of a windmill," causing them to rotate together with the shaft to which they were fixed. Gearing transmitted the motion of this shaft to the driving wheels. The inventor proposed to raise steam by permitting water to drop upon a metal plate, kept at an intense heat by means of a strong fire, which was stimulated by a pair of bellows. WILLIAM BRUNTON Born at Dalkeith, Scotland, May 26, 1777. Died at Camborne, Cornwall, England, October 5, 1857. The eldest son of Robert Brunton, a watch and clock maker, William Brunton studied mechanics first in his father's shop and then in England, under the guidance of his grandfather, who was a colliery viewer. When he was thirteen years of age, in 1790, he began work in the fitting shops of the New Lanark cotton mills of David Dale and Richard Arkwright. Remaining in that establishment for six years he then went to the Boulton & Watt shops, at Soho, where he was gradually promoted, until he finally became the foreman and superintendent of engine manufacturing. In 1813, he went to the Jessop's Butterley Works, but remained there only three years, when he became a partner and mechanical manager of the Eagle Foundry, at Birmingham, a connection that he maintained for ten years. From 1825 to 1835, he was engaged in the practice of civil engineering in London. In the last-mentioned year, he became a share owner in the Cwm Avom tin works in Glamorganshire, Wales, where he superintended the erection of copper-smelting furnaces and rolling mills. He was also connected with the Maesteg Works in the same county and a brewery at Neath. Through the failure of these enterprises he lost the savings of his lifetime and was never again engaged actively in business. He invented many ingenious modes of reducing and manufacturing metals; made some of the original engines used on the Humber and the Trent and also some of the earliest that were seen on the Mersey, including those four vessels first operated on the Liverpool ferries in 1814. He also invented the calciner that was put in use in the tin mines at Cornwall and the silver ore works in Mexico. Like nearly all the other engineers of his day, Brunton planned a steam carriage. This was built when he was at the Butterley Works, in 1813, and was called "the mechanical traveller." Although a peculiar machine it worked with some degree of success, at a gradient of one in thirty-six, all the winter of 1814, at the Newbottle Colliery. The machine was a steam horse rather than a steam carriage. It consisted of a curious combination of levers, the action of which nearly resembled that of the legs of a man in walking, with feet alternately made to press against the ground of the road or railway, and in such a manner as to adapt themselves to the various inclinations or inequalities of the surface. The feet were of various forms, the great object being to prevent them from injuring the road, and to obtain a firm footing, so that no jerks should take place at the return of the stroke, when the action of the engine came upon them; for this purpose they were made broad, with short spikes to lay hold of the ground. The boiler was a cylinder of wrought iron, five feet six inches long, three feet in diameter, and of such strength as to be capable of sustaining a pressure of upwards of four hundred pounds per square inch. The working cylinder was six inches in diameter, and the piston had a stroke of twenty-four inches; the step of the feet was twenty-six inches, and the whole machine, including water, weighed about forty-five hundredweight. In 1815, the engine of this carriage exploded and killed thirteen persons. THOMAS TINDALL A steam engine was patented, in 1814, by Thomas Tindall, of Scarborough. The inventor proposed to use this for an infinitude of purposes, such as driving carriages for the conveyance of passengers, ploughing land, mowing grass and corn, or working thrashing machines. The carriage had three wheels--one for steering. The steam engine drove, by spur gearing, four legs, which, pushing against the ground, moved the carriage. The engine could also be made to act upon the two hind wheels for ascending hills, or for drawing heavy loads. A windmill, driven partly by the action of the wind, and partly by the exhaust steam from the engine, was used as adjunct power. JOHN BAYNES A very ingenious modification of William Brunton's mechanical traveler, was the subject of a patent granted to John Baynes, a cutler, of Sheffield, England, in September, 1819. The mechanism was designed to be attached to carriages for the purpose of giving them motion by means of manual labor, or by other suitable power, and consisted of a peculiar combination of levers and rods. The patentee also stated that there might be several sets of the machinery above described for working each set with a treadle, or even only one set and treadle. Then he added: "I prefer two for ordinary purposes, particularly when only a single person is intended to be conveyed in the carriage, who may work the same by placing one foot on each treadle, in which the action will be alternate. The lower parts of the leg should be so formed or shod as not to slip upon the ground. This machinery may be variously applied to carriages, according to circumstances, so as that the treadles may be worked either behind or before the carriage, still producing a forward motion; in some cases it may be advantageous to joint the front end of the treadles to the carriage and press the feet on the hind ends." JULIUS GRIFFITHS Among those who came to the front with plans for steam carriages for the public highways, soon after the roads began to be improved, was Julius Griffiths, of Brompton Crescent. In 1821, he patented a steam carriage that was built by Joseph Bramhah, a celebrated engineer and manufacturer. It is said that part of the mechanism was designed by Arzberger, a foreigner. The carriage has been termed by some English authorities "the first steam coach constructed in this country, expressly for the conveyance of passengers on common roads." It was repeatedly tested during a period of three or four years, but failed on account of boiler deficiencies. Alexander Gordon said of it: "The engines, pumps, and connections were all in the best style of mechanical execution, and had Mr. Griffiths' boiler been of such a kind as to generate regularly the required quantity of steam, a perfect steam carriage must have been the consequence." The carriage moved easily and answered very readily to guidance. The vehicle was a double coach and could carry eight passengers. This locomotive had two vertical working steam cylinders, which with the boiler, condenser, and other details were suspended to a wood frame at the rear of the carriage. The engineer was seated behind and did his own firing. The boiler was a series of horizontal water tubes, one and one-half inches in diameter and two feet long; at each end the flanges were bolted to the vertical tubes forming the sides of the furnace. Attached to the wood frame in front of the driving wheels, was a small water tank, and a force pump supplied the boiler with water. The steam, passing through the cylinder, went into an air condenser. The power of the engines was communicated from the piston rods to the driving wheels of the carriage by sweep rods, the lower ends of which were provided with driving pinions and detents, which operated upon toothed gear fixed to the hind carriage axle. The object of this mechanism was to keep the driving pinions always in gear with the toothed wheels, however the engine and other machinery might vibrate or the wheels be jolted upon uneven ground. The boiler, engine, and other working parts were suspended to the wood frame by chain slings, having strong spiral springs so as to reduce the vibration from rough roads. EDMUND CARTWRIGHT Born at Marnham, Nottinghamshire, England, April 24, 1743. Died at Hastings, October 30, 1823. Cartwright was educated at Oxford and secured a living in the English church. He devoted himself to the ministry and to literature until 1784, when he became interested in machinery and in the following year invented the power loom. He took out other patents and also gave some attention to devising a mechanical carriage propelled by man power. In 1822, he made a vehicle that was moved by a pair of treadles and cranks worked by the driver. Even the steam engine engaged his attention. Some improvements which he proposed in it are recorded in works on mechanics. While residing at Eltham, in Lincolnshire, he used frequently to tell his son that, if he lived to be a man, he would see both ships and land-carriages impelled by steam. At that early period he constructed a model of a steam engine attached to a barge, which he explained, about the year 1793, to Robert Fulton. It appears that even in his old age, only a year before his death, he was actively engaged in endeavoring to contrive a plan of propelling land-carriages by steam. T. BURTSALL An engineer, of Edinburgh, Scotland, T. Burtsall, in conjunction with J. Hill, of London, got out, in 1824, a patent for flash or instantaneous generation boilers. His aim was to make the metal of the boiler store heat instead of a mass of water, and he accomplished this by heating the boiler to anywhere from two hundred and fifty degrees to six hundred degrees Fahrenheit, keeping the water in a separate vessel and pumping it into the boiler as steam was required. A coach that he built to run with this boiler weighed eight tons, and it was a failure, simply because the boiler could not make steam fast enough. T. W. PARKER A working model of a light steam carriage was made by T. W. Parker, of Illinois, in 1825. Three wheels supported the carriage, the two hind wheels being eight feet in diameter. The double-cylinder engine was used. GEORGE POCOCK One of the most curious of the wind vehicle productions that held the fancy of scientists to a slight extent in the early part of the nineteenth century was the charvolant or kite carriage that was devised by George Pocock in 1826, and built by Pocock and his partner, Colonel Viney. This was a very light one-seated carriage, drawn by a string of kites harnessed tandem. With a good wind these kites developed great power and it is said that the carriage whirled along, even on heavy roads, at the rate of a mile in three or even two and one-half minutes. Once Viney and Pocock made the trip from Bristol to London, and they often ran their carriage around Hyde Park and the suburbs of London. As the wind could not always be depended upon the charvolant was provided with a rear platform, upon which a pony was carried for emergencies. SAMUEL BROWN In 1826, Samuel Brown applied his gas-vacuum engine to the propulsion of a carriage, which was effectively worked along the public roads in England. It even ascended the very steep acclivity of Shooter's Hill, in Kent, to the astonishment of numerous spectators. The expense of working this machine was, however, said far to exceed that of steam, and this formed a barrier to its introduction. Experiments with this engine for the propulsion of vessels on canals or rivers were also made by the Canal Gas Engine Company. Brown patented a locomotive for common roads in 1823. JAMES NEVILLE In January, 1827, James Neville, an engineer of London, took out a patent for a "new-invented improved carriage," to be worked by steam, the chief object of which appears to have been to provide wheels adapted to take a firm hold of the ground. He proposed to make each of the spokes of the wheels by means of two rods of iron, coming nearly together at the nave, but diverging considerably apart to their other ends, where they were fastened to an iron felly-ring of the breadth of the tire, and this tire was to be so provided with numerous pointed studs about half an inch long as to stick into the ground to prevent the wheel from slipping round. A second method of preventing this effect was to fasten upon the tire a series of flat springing plates, each of them forming a tangent to the circumference, so that as the wheels rolled forward each plate should be bent against the tire and recover its tangential position as it left the ground in its revolution. It was considered that the increased bearing surface of the plate, and the resistance of its farthest edge, would infallibly prevent slipping. For propelling the carriage Neville proposed to use a horizontal vibrating cylinder to give motion direct to the crank axis by means of the compound motion of the piston rod, as invented by Trevithick, the motion to the running wheels to be communicated through gear of different velocities. T. S. HOLLAND Among the singular propositions for producing a locomotive action that were brought out early in the eighteenth century was that invented by T. S. Holland, of London, for which he took out a patent in December, 1827. The invention consisted in the application of an arrangement of levers, similar to that commonly known by the name of lazy-tongs, for the purpose of propelling carriages. The objects appeared to be to derive from the reciprocating motion of a short lever a considerable degree of speed, and to obtain an abutment against which the propellers should act horizontally, in the direction of the motion of the carriage, instead of obliquely to that motion, as is the case when carriages are impelled by levers striking the earth. JAMES NASMYTH Born in Edinburgh, Scotland, August 19, 1808. Died in South Kensington, England, May 6, 1890. While yet in his teens James Nasmyth showed great mechanical ability and constructed a small steam engine. In 1821, he became a student at the Edinburgh School of Arts. Six years later he had made a very substantial advance in his experiments. The story of what he endeavored to accomplish is best told by himself. In later life he wrote: "About the year 1827, when I was nineteen years old, the subject of steam carriages to run upon common roads occupied considerable attention. Several engineers and mechanical schemers had tried their hands, but as yet no substantial results had come of their attempts to solve the problem. Like others, I tried my hand. Having made a small working model of a steam carriage, I exhibited it before the members of the Scottish Society of Arts. The performance of this active little machine was so gratifying to the Society, that they requested me to construct one of such power as to enable four or six persons to be conveyed along the ordinary roads. The members of the Society, in their individual capacity, subscribed three hundred dollars, which they placed in my hands as the means for carrying out their project. I accordingly set to work at once, and completed the carriage in about four months, when it was exhibited before the members of the Society of Arts. Many successful trials were made with it on the Queensferry Road, near Edinburgh. The runs were generally of four or five miles, with a load of eight passengers sitting on benches about three feet from the ground. The experiments were continued for nearly three months, to the great satisfaction of the members. "I may mention that in my steam carriage I employed the waste steam to create a blast or draught, by discharging it into the short chimney of the boiler at its lowest part; and I found it most effective. I was not at that time aware that George Stephenson and others had adopted the same method; but it was afterwards gratifying to me to find that I had been correct as regards the important uses of the steam blast in the chimney. In fact, it is to this use of the waste steam that we owe the practical success of the locomotive engine as a tractive power on railways, especially at high speeds. "The Society of Arts did not attach any commercial value to my road carriage. It was merely as a matter of experiment that they had invited me to construct it. When it proved successful they made me a present of the entire apparatus. As I was anxious to get on with my studies, and to prepare for the work of practical engineering, I proceeded no further. I broke up the steam carriage, and sold the two small high-pressure engines, provided with a strong boiler, for three hundred and thirty-five dollars, a sum which more than defrayed all the expenses of the construction and working of the machine." F. ANDREWS It is said that F. Andrews, of Stamford Rivers, Essex, England, was the inventor of the pilot steering wheel which was used by Gurney and has been often used since then. He also made other improvements in steam carriages in 1826. One of his patents was for the oscillating cylinders that were used by James Neville in his steam carriage. Andrews' steam carriage was a failure, like many others of that period, on account of imperfect working of the boiler. HARLAND Dr. Harland, of Scarborough, in 1827 invented and patented a steam carriage for running on common roads. A working model of the steam coach was perfected, embracing a multi-tubular boiler for quickly raising high-pressure steam, with a revolving surface condenser for reducing the steam to water again by means of its exposure to the cold draught of the atmosphere through the interstices of extremely thin laminations of copper plates. The entire machinery placed under the bottom of the carriage, was borne on springs; the whole being of an elegant form. This model steam carriage ascended with ease the steepest roads. Its success was so complete that Harland designed a full-sized carriage; but the demands upon his professional skill were so great that he was prevented going further than constructing a pair of engines, the wheels, and a part of the boiler. Harland spent his leisure time in inventions and in that work was associated with Sir George Cayley. He was Mayor of Scarborough three times. He died in 1866. PECQUEUR Chief of shops at the Conservatoire des Arts et Metier, Paris, Pecqueur made a steam wagon in 1828. His vehicle had two drive wheels keyed to two pairs of axles. His planet gearing was the origin of the balance gear. JAMES VINEY Colonel James Viney, Royal Engineers, in 1829 patented a boiler intended for steam carriages. His plan was to have two, three, four, or six concentric hollow cylinders containing water, between which the fire from below passed up. An annular space for water, and an annular space or flue for the ascending fire, were placed alternately, the water being between two fires. CHEVALIER BORDINO An Italian officer of engineers, Bordino devised and constructed a steam carriage for the diversion of his little daughter. It was a carriage à la Dumont, and for forty years was used regularly in the carnival festivities of Turin in the early part of the nineteenth century. It is still preserved as donated by the widow of Bordino to the Industrial Museum of Turin. CLIVE Best known as a writer of articles on the steam carriage, over the signature of Saxula, in the Mechanic's Magazine, Clive, of Cecil House, Staffordshire, England, also engaged in experimenting with steam. In 1830, he secured patents for two improvements in locomotives, one increasing the diameter of the wheels and the other increasing the throw of the cranks. After a time he seems to have lost faith in the steam carriage, for in 1843 he wrote: "I am an old common road steam carriage projector, but gave it up as impracticable ten years ago, and I am a warm admirer of Colonel Maceroni's inventions. My opinion for years has been, and often so expressed, that it is impossible to build an engine sufficiently strong to run even without a load on a common road, year by year, at the rate of fifteen to twenty miles an hour. It would break down. Cold iron at that speed cannot stand the shock of the momentum of a constant fall from stones and ruts of even an inch high." SUMMERS AND OGLE Two steam carriages built by Summers and Ogle, in 1831, were among the most successful vehicles of their kind in that day. One of these carriages had two steam cylinders, each seven and one-half inches in diameter and with eighteen-inch stroke. It was mounted on three wheels and its boiler would work at a pressure of two hundred and fifty pounds per square inch. Passengers were carried in the front and the middle of the coach, while the tank and the boiler were behind. The second carriage had three steam cylinders, each four inches in diameter, with a twelve-inch stroke. When the committee of the House of Commons was investigating the subject of steam locomotion on the common roads Summers and Ogle appeared and gave interesting particulars concerning their vehicles. The greatest velocity ever obtained was thirty-two miles an hour. They went from the turnpike gate at Southampton to the four-mile stone on the London road, a continued elevation, with one slight descent, at the rate of twenty-four and a half miles per hour, loaded with people; twenty passengers were often carried. Their first steam carriage ran from Cable Street, Wellclose Square, to within two miles and a half of Basingstoke, when the crank shaft broke, and they were obliged to put the whole machine into a barge on the canal and send it back to London. This same machine had previously run in various directions about the streets and outskirts of London. With their improved carriage they went from Southampton to Birmingham, Liverpool and London, with the greatest success. The Saturday Magazine, of October 6, 1832, gave an account of one of their trials as follows: "I have just returned from witnessing the triumph of science in mechanics, by traveling along a hilly and crooked road from Oxford to Birmingham in a steam carriage. This truly wonderful machine is the invention of Captain Ogle, of the Royal Navy, and Mr. Summers, his partner, and is the first and only one that has accomplished so long a journey over chance roads, and without rails. Its rate of traveling may be called twelve miles an hour, but twenty or perhaps thirty down hill if not checked by the brake, a contrivance which places the whole of the machinery under complete control. Away went the splendid vehicle through that beauteous city (Oxford) at the rate of ten miles an hour, which, when clear of the houses, was accelerated to fourteen. Just as the steam carriage was entering the town of Birmingham, the supply of coke being exhausted, the steam dropped; and the good people, on learning the cause, flew to the frame, and dragged it into the inn yard." GIBBS An English engineer, Gibbs made a special study of the steam carriage of Sir Charles Dance in 1831. As a result of his investigations he built a steam drag in 1832. This was intended to draw passenger carriages and it had a boiler with spirally descending flue placed behind the driving wheels. In 1832, in conjunction with his partner, Applegate, he patented a steam carriage with a tubular boiler and oscillating engine cylinders. The power from the axle was transmitted to the driving wheels through friction bands, arranged in the bases of the wheels so that one or both wheels could be coupled to the axles. CHARLES DANCE An enthusiastic motorist, Sir Charles Dance, of London, in the first third of the ninteenth century did a great deal to encourage the engineers who were inventing steam road vehicles. He was financially interested in several of the companies that were organized to run steam coaches over the common roads. He was the backer of Goldsworthy Gurney, and was also engaged in building for himself. His most famous car was a coach that ran every day from the Strand, London, to Brighton. This was an engine mounted on four wheels with a tall rectangular funnel that narrowed toward the top. Above the engine were seats for six or seven persons besides the driver. Behind the engine was a vehicle like a boxcar low hung on wheels. On the side of this box was emblazoned the coat of arms of its owner. On the roof seat in front were places for four passengers. On a big foot-board behind, stood the footman. This carriage was one of the spectacular sights of London at that time and great crowds gathered in the Strand every day to witness its departure. Dance ran Gurney's coaches on the Cheltenham and Gloucester Road until public opposition compelled his withdrawal, but after that he was a joint patentee with Joshua Field, of an improved boiler. This was applied to the road carriage above mentioned and the first trips were made in September, 1833, with a drag and omnibus attached, a speed of sixteen miles an hour being attained. On the first trip from London to Brighton, fifteen passengers were carried and the distance of fifty-two miles was covered in five and a half hours, the return journey being performed in less than five hours. About the middle of October the steam drag and omnibus were put upon the road between Wellington Street, Waterloo Bridge, and Greenwich, where it continued to run for a fortnight, with a view of showing the public in London what could be done in this direction. The proprietor had no intention of making it a permanent mode of conveyance, and therefore kept the company as select as he could by charging half a crown for tickets each way. JOSHUA FIELD Born in 1786. Died in 1863. A member of the well-known firm of Maudsley, Sons & Field, marine engineers, of London, England, Joshua Field took out a patent for an improved boiler, in conjunction with Sir Charles Dance. The firm made an improved vehicle for Dance, and in 1835 Field constructed for himself a steam carriage that made a trip in July with a party of guests. The carriage was driven up Denmark Hill, and did the distance, nine miles, in forty-four minutes. It also ran several times to Reading and back, at the rate of twelve miles an hour. One of the subscribers towards the building of this carriage, said that it was a success mechanically, but not economical. Field was one of the six founders of the Institution of Civil Engineers. DIETZ Previous to the time that the carriage of Francis Maceroni was taken to France, an engine designed by Dietz was run in the streets of Paris. In the reports of the Academy of Sciences and Academy of Industry in Paris, in 1840, this vehicle was described. The carriage had eight wheels, two of which were large and gave the impulsion. The six smaller wheels rose and fell according to the irregularity of the road, and at the same time assisted in bearing the weight of the carriages. The wheels were bound with wood tires, having cork underneath. The locomotive was a drag, drawing a carriage for passengers. The engine was of thirty horse-power, and a speed of ten miles an hour was made. YATES A steam carriage was built by Messrs. Yates & Smith, London, in 1834. It had a trial in July of that year, running from the factory in Whitechapel, along High and several other streets, at the rate of ten to twelve miles an hour. Vibrating engines, working on horizontal framing, were used. The coach resembled an ordinary stage-coach. G. MILLICHAP In a letter to an English engineering paper in 1837, G. Millichap, of Birmingham, claimed to have a locomotive carriage building. He wrote: "If your correspondent will take the trouble to call at my house I shall be happy to show him a locomotive carriage in a state of great forwardness, intended decidedly for common roads." JAMES CALEB ANDERSON Born in Cork, Ireland, July 21, 1782. Died in London, April 4, 1861. The father of Sir James Caleb Anderson, of Buttevant Castle, Ireland, was John Anderson, a celebrated merchant of Ireland, famous as the founder of the town of Fermoy. The son gave much attention to the subject of steam and steam propulsion, and made many experiments, taking out several patents. In 1831, he lodged a specification for improvements in machinery for propelling vessels on water; in 1837, for improvements in locomotive engines, and in 1846, for improvements in obtaining motive power and applying it to the propulsion of cars and vessels and the driving of machinery. His 1831 patent was for a manually-propelled vehicle, a carriage in which twenty-four men were arranged on seats, like rowers in a boat, but in two tiers, one above the other. The action was nearly the same as the pulling of oars, the only difference being that all the men sitting on one seat pulled at one horizontal cross-bar, each extremity of which was furnished with an anti-friction roller that ran between guide rails on the opposite sides of the carriage. The ends of each of these horizontal bars were connected to reciprocating rods that gave motion to a crank shaft, on which were mounted spur gear that actuated similar gear on the axis of the running wheels of the carriage; so that by sliding the gear on the axis of the latter any required velocity could be communicated to the carriage, or a sudden stop made. It was proposed to employ this as a drag, to draw one or more carriages containing passengers after it. The patentee had chiefly in view the movement of troops by this method. Anderson gave financial support to W. H. James, in 1827, until he fell into pecuniary difficulties. Ten years later he re-engaged in steam carriage construction on his own account, and according to his own reports he expended over one hundred and fifty thousand dollars on experiments. It was said that he failed in twenty-nine carriages before he succeeded in the last. He patented a boiler that was said to be a poor copy of Walter Hancock's boiler. Then he organized a joint-stock company, the Steam Carriage and Wagon Company, which proposed to construct steam drags in Dublin and in Manchester, which, when completed, were to convey goods and passengers at double the speed and at half the cost of horse carriages. Anderson said: "I produce and prove my steam drags before I am paid for them, and I keep them in repair; consequently, neither the public nor the company runs any risk. The first steam carriage built for the company is nearly completed. It will speak for itself." In the Mechanic's Magazine, June, 1839, a Dublin correspondent writes: "I was fortunate enough to get a sight of Sir James Anderson's steam carriage, with which I was much pleased. It had just arrived from the country, and was destined for London in about three weeks. The engine weighs ten tons, and will, I dare say, act very well. I shall have an opportunity of judging that, as the tender is at Cork. It has a sort of diligence, not joined, but to be attached to the tender, making in all three carriages. I talked a great deal about it to one of his principal men, who was most lavish in its praises, especially as regards the boiler." In August, 1839, the carriage arrived in London. In 1840, a report said: "Several steam carriages are being built at Manchester and Dublin, under Sir James Anderson's patents, and one has been completed at each place. At Manchester the steam drag had been frequently running between Cross Street and Altrincham, and the last run was made at the rate of twenty miles an hour, with four tons on the tender, in the presence of Mr. Sharp, of the firm of Sharp, Roberts and Company, of Manchester, and others." A newspaper of the same year reported that an experimental trip of Anderson's steam drag for common roads took place on the Howth Road, Dublin. It ran about two hours, backing, and turning about in every direction--the object being chiefly to try the various parts in detail. It repeatedly turned the corners of the avenues at a speed of twelve miles an hour, the steam pressure required being only forty-six pounds per square inch. No smoke was seen, and little steam was observed. The whole machinery was ornamentally boxed in, so that none of the moving parts was exposed to view, and it was found that the horses did not shy at this carriage. The company had great plans for travel communication by means of these drags between the chief towns in Ireland, as soon as a few of the steam carriages were finished. An even more pretentious scheme involved a service in conjunction with the railway trains from London, carriages to be run from Birmingham to Holyhead, whence passengers were to be conveyed to Dublin by steamer; from Dublin to Galway the steam drags were to be employed; and thence to New York per vessel touching at Halifax; thus making Ireland the stepping-stone between England, Nova Scotia, and the United States of America. But all these plans came to naught. Anderson continued to take out patents down to as late as 1858. He devoted more than thirty years of his life to the promotion of steam locomotion on common roads. ROBERT DAVIDSON Robert Davidson, of Aberdeen, was probably the first to make an electrically propelled carriage large enough to carry passengers. This he did in 1839. His carriage could carry two persons when traveling over a fairly rough road, and though the prospects were enticing enough to cause investment in the enterprise, Davidson's subsequent work was on rail vehicles. W. G. HEATON W. G. and R. Heaton, of Birmingham, England, built several steam carriages which operated with various degrees of success in their neighborhood. Their patent was dated in October, 1830. The patent aimed particularly at the guidance of a locomotive carriage, and the management of the steam apparatus so that the power and speed might be accommodated to the nature of the road, the quantity of the load, and so on. For the purpose of steering the carriage, a vertical spindle was placed at some distance before the axle of the front wheels and on its lower end a small drum was fixed. Around this drum was coiled a chain with its middle fixed upon the drum, and its ends made secure to the front axle formed a triangle with the drum, situated at the angle opposite the longest side. The other end of the vertical spindle was connected with a frame situated in front of the coachman's or rather the steersman's seat and here on the spindle was a horizontal beveled-toothed wheel. Over this wheel an axis extended, terminating in two crank handles proceeding from the axes in different directions, so that one was down when the other was up. Upon this axis was fixed another beveled-toothed wheel taking into the first. When these wheels were turned in one direction the right-hand fore wheel of the carriage advanced and the coach turned towards the left, while when they were turned in the other direction the left-hand wheel advanced and the carriage turned towards the right. The driving wheels were connected with the axle by means of a pair of ratchets furnished with a double set of ratchet teeth and a reversing pall. By this one wheel could be advanced or backed while the other remained stationary, or moving in a contrary direction, an arrangement necessary for turning and backing. The steersman controlled the reversing pall by connecting rods and lever. Motion was communicated to the driving wheels by a double set of spur wheel gear, arranged to give different powers or velocities, by having both a large and a small wheel fixed on the driving as well as the driven axis. By shifting the large wheel on the driving axis into gear with the small wheel on the driven axis speed was obtained, and by shifting their relative position till the small wheel on the driving axis came into gear with the large wheel on the driven axis, power was obtained at the expense of speed. These two axes were kept at the same distance from each other by means of connecting rods, although the relative positions might be changed by the motion of the carriage on rough roads. In August, 1833, the Heatons placed a steam drag on the road between Worcester and Birmingham. A slight accident occurred at the start, but after repairs were made the trial was a success. Attached to the engine was a stage-coach, carrying twenty passengers, the load weighing nearly two tons. Lickey Hill was ascended, a rise of one in nine, and even one in eight in some places. Many parts of the hill were very soft, but by putting both wheels in gear they ascended to the summit, seven hundred yards in nine minutes. A company was formed in Birmingham to construct and run these carriages, subject to the condition of keeping up an average speed of ten miles an hour. A new carriage was built and tried in 1834, but after trials, the Messrs. Heaton dissolved their contract, as they were unable to do more than seven or eight miles an hour. After spending upwards of ten thousand dollars in endeavors to effect steam traveling, they retired from the field, stating that the wear and tear were excessive at ten miles an hour, and that the carriage was heavy, and wasteful in steam. F. HILL An English engineer, connected with the Deptford Chemical Works, Hill was among the first to be interested in steam-road locomotion. He was familiar with Hancock's experiments and made a carriage of his own that was tried in 1840. He journeyed to Sevenoaks and elsewhere and ran up steep hills with the carriage, fully loaded, at twelve miles an hour, and on the level at sixteen miles an hour. He adopted the compensating gear that was invented by Richard Roberts and that by some writers has been credited to him. To put Hill's patents to practical use The General Steam Carriage Company was formed in 1843. The probable success of the company was based upon the belief that there was a demand for additional road accommodations in order that road locomotion should counteract the exorbitant charges made by the gigantic railway monopoly for conveying goods short distances. The company stated in its prospectus "that while they confidently believe the improved steam coach which they have engaged and propose to employ in the first instance to be the most perfect now known in England, they do not bind themselves to adhere to any particular invention, but will avail themselves of every discovery to promote steam coach conveyance." Trial trips were made on the Windsor, Brighton, Hastings, and similar roads, and with success. Once the carriage made a trip to Hastings and back, a distance of one hundred and twenty-eight miles, in one day, half the time occupied by the stage coaches. The Mechanic's Magazine said: "We accompanied Hill, about a year ago, in a short run up and down the hills about Blackheath, Bromley, and neighborhood; and we had again the pleasure of accompanying him in a delightful trip, on the Hastings Road, as far as Tunbridge and back. The manner in which his carriage took all the hills, both in the ascent and the descent, proved how completely every difficulty on this head had been surmounted." In the Hill carriage, both the coach and the machinery were erected upon a strong frame mounted upon substantial springs. In the rear were the boiler, furnace, and water tanks, with a place for the engineer and fireman. In front was a coach body with seats for six inside, three on the box, and the conductor in front. The front part of the carriage was also suspended upon springs. The carriage was propelled by a pair of ten-inch cylinders and pistons, horizontally placed beneath the carriage. These acted upon two nine-inch cranks, coupled to the main axle through compensating gear; the two six-foot six-inch diameter driving wheels had the full power of the engines passed through them. The weight of the boiler when empty was two thousand three hundred pounds, and it had a capacity of about sixty gallons of water, while one hundred gallons more were contained in the tanks. The total weight of the carriage, including water, coke, and twelve passengers, was less than four tons. On heavy and rough roads the steam pressure was seventy pounds per square inch, but on good roads only sixty pounds. The average speed was sixteen miles an hour, but on a level twenty miles an hour was reached. As late as 1843, Hill's carriages were running from London to Birmingham, having been in operation four or five years. Smooth in motion, they carried their passengers comfortably, but soon went out of use. GOODMAN Early in the forties a small road locomotive was made by Goodman, of Southwark, London. It was worked by a pair of direct-acting engines, coupled to the crank shaft. A chain pinion on the crank shaft transmitted motion to the main axle through an endless pitch chain working over a chain wheel of larger diameter on the driving shaft. The smoke from the boiler was conducted by a flue placed beneath the carriage. The vehicle had a speed of from ten to twelve miles an hour. NORRGBER A correspondent of The Mechanic's Magazine, of London, wrote in 1843: "Norrgber, of Sweden, a locksmith and an ingenious mechanic, made a steam carriage which ran between Copenhagen and Corsoer, carrying thirty passengers, the engine being of eight horse-power." J. K. FISHER A small steam carriage, that in general character was like a railroad locomotive, was designed by J. K. Fisher, of New York, in 1840. It was not until 1853, however, that he went beyond this. Then he built another carriage, with driving wheels five feet in diameter, and two steam cylinders four inches in diameter, with ten-inch stroke. This carriage attained a speed of fifteen miles an hour on good pavements. During the next two years, Fisher made many trips, sometimes running twelve miles an hour without excessive wear. In his later engines he introduced several novelties, among them being parallel connections between the crank shaft and the driving axle. In the steering gear a screw was placed across the front part of the carriage carrying a nut, to which the end of an elongated reverted pole was jointed. The screw was turned by bevel gearing, one wheel being keyed to the end of the screw, and the other to the steerage rod, the opposite end of this rod having a lever placed within easy access of the footplate. Fisher's carriages were driven by direct-acting engines, one cylinder on each side of the smoke-box. R. W. THOMPSON Born in Stonehaven, England, in 1822. Died, March 8, 1873. R. W. Thompson came to the United States in early life, but returned to England and engaged in scientific experimenting and studying, and in engineering at Aberdeen and Dundee. He invented a rotary engine during this period of his life. In 1846, being then in business for himself, he conceived the idea of india-rubber tires and perfected this in 1876. In December of that year he made a small road locomotive to draw an omnibus and this was sent to the Island of Ceylon. Other road steamers of Thompson's design were manufactured and sent to India and elsewhere. ANTHONY BERNHARD In 1848, a compressed-air carriage invented by Anthony Bernhard, Baron von Rathen, was built in England. It weighed three tons, and on its first trip was driven at a speed of eight miles an hour. Upon one occasion it made twelve miles an hour on a trip from Putney to Wandsworth, carrying twenty passengers. Until near 1870, Baron von Rathen was engaged in inventing compressed-air engines. BATTIN In 1856, Joseph Battin, of Newark, N. J., constructed a steam carriage with a vertical boiler and oscillating engines. RICHARD DUDGEON A small locomotive for the common roads was built in 1857, Dy Richard Dudgeon, an engineer, of New York. It had two steam cylinders, each three inches in diameter and with sixteen-inch stroke, and drew a light carriage at ten miles an hour on gravel roads. The carriage was destroyed by fire at the New York Crystal Palace in 1858. Dudgeon is said to have afterward built another carriage, which was larger and more clumsy than the other. A few years ago this was discovered in an old barn in Locust Valley, L. I. It was fixed up and started out and demonstrated that, old as it was, it could go at a speed of more than ten miles an hour. LOUGH AND MESSENGER In 1858, Messrs. Lough and Messenger, of Swindon, England, designed and erected a steam-road locomotive which for two years ran at fifteen miles an hour on level roads, and six miles an hour up grades of one in twenty. The engine had two cylinders, each three and one-half inches in diameter and with five-inch stroke, working direct on to the crank axle. The driving wheels were three and one-half feet in diameter, and the leading wheels two feet in diameter. The vertical boiler fixed on the frame was worked at one-hundred-and-twenty-pound pressure. The tanks held forty gallons of feed water. The total weight of the locomotive was eight hundred pounds. THOMAS RICKETT When the revival of interest in the common-road steam locomotive began in England, about 1857, Thomas Rickett, of Castle Foundry, Buckingham, was one of the first to give attention to the subject. He built a road locomotive in 1858 for the Marquis of Stafford. This engine had two driving wheels and a steering wheel. The boiler was at the back with the steam cylinders horizontally on each side of it. Three passengers were carried. The carriage was steered by means of a lever connected with the fork of the front wheel. The cylinders were three inches in diameter, with nine-inch stroke; the working steam pressure was one hundred pounds per square inch. The driving wheels were three feet in diameter. The weight of the carriage when fully loaded was only three thousand pounds. On level roads the speed was about twelve miles an hour. An account of one of the trips in 1859 was as follows in the columns of The Engineer: "Lord Stafford and party made another trip with the steam carriage from Buckingham to Wolverton. His lordship drove and steered, and although the roads were very heavy, they were not more than an hour in running the nine miles to Old Wolverton. His lordship has repeatedly said that it is guided with the greatest ease and precision. It was designed by Mr. Rickett to run ten miles an hour. One mile in five minutes has been attained, at which it was perfectly steady, the centre of gravity being not more than two feet from the ground. A few days afterwards this little engine started from Messrs. Hayes' Works, Stoney Stratford, with a party consisting of the Marquis of Stafford, Lord Alfred Paget, and two Hungarian noblemen. They proceeded through the town of Stoney Stratford at a rapid pace, and after a short trip returned to the Wolverton railway station. The trip was in all respects successful, and shows beyond a doubt that steam locomotion for common roads is practicable." Two other engines were built by Rickett, one of them for the Earl of Caithness. Some improvements were installed in this carriage, which was intended to carry three passengers. The weight of the carriage, fully loaded, was five thousand pounds. In this carriage, the Earl of Caithness traveled from Inverness to his seat, Borrogill Castle, within a few miles of John o' Groat's House. He describes his trip as follows: "I may state that such a feat as going over the Ord of Caithness has never before been accomplished by steam, as I believe we rose one thousand feet in about five miles. The Ord is one of the largest and steepest hills in Scotland. The turns in the road are very sharp. All this I got over without trouble. There is, I am confident, no difficulty in driving a steam carriage on a common road. It is cheap, and on a level I got as much as nineteen miles an hour." The Earl of Caithness brought the trial to a successful result, and some expert authorities jumped to the conclusion that at once steam traveling upon the high roads of England would be availed of to a large extent; but that did not happen. In 1864, Mr. Rickett furnished an engine for working a passenger and light goods service in Spain, intended to carry thirty passengers up an incline of one in twelve, at ten miles an hour. The steam cylinders were eight inches in diameter, and the driving wheels four feet in diameter. The boiler would sustain a pressure of two hundred pounds. Rickett's later engines had spur wheels; but his last engines were direct-acting. In November, 1864, he says: "The direct-acting engines mount inclines of one in ten easily; whether at eight, four, two, or one mile an hour, on inclines with five tons behind them, they stick to their work better than geared engines." DANIEL ADAMSON In 1858 the firm of Daniel Adamson & Co., of Dukinfield, near Manchester, England, built a common-road locomotive for a Mr. Schmidt. A multi-tubular boiler was used, two and one-half feet in diameter and five and one-half feet long, with a working pressure of one hundred and fifty pounds per square inch. The engine, which weighed five thousand six hundred pounds and was borne on three wheels, was calculated to run at eight miles an hour. A steam cylinder of six-inch diameter was attached to each side of the locomotive, and these cylinders actuated a pair of driving wheels three feet six inches in diameter. Mr. Schmidt gave this vehicle a thorough trying out and especially raced it with several competitors. On one of these races, in 1867, with a Boulton steam carriage, the start was made from Ashton-under-Lyne, for the show ground at Old Trafford, a distance of over eight miles. Although the Adamson engine was the larger, the smaller one easily passed it during the first mile, and kept a good lead all the way, arriving at Old Trafford under the hour. Mr. Schmidt sent his road locomotive to the Havre Exhibition, in 1868, and a trial of its powers was made by French engineers, and M. Nicole, director of the exhibition. Mr. Schmidt conducted the engine himself, and to it was attached an omnibus containing the commissioners. The engine and carriage traversed several streets of Havre and mounted a sharp incline. Other trips were made to several villages in the neighborhood of the exhibition, and the engine behaved very satisfactorily. STIRLING In a road steamer designed by Stirling, of Kilmarnock, in 1859, the five traveling wheels were mounted upon springs. A single wheel was used as a driver, and more or less weight was thrown upon this wheel. The leading and trailing wheels swiveled in concert, in opposite directions, by means of right and left hand worms and worm wheels. The carriage was thus made to move in a curve of comparatively short radius. W. O. CARRETT In 1860, George Salt, of Saltshire, England, employed W. O. Carrett, of the firm of Carrett, Marshall & Co., proprietors of the Gun Foundry at Leeds, to design and build a steam pleasure carriage for him. The carriage was first shown and exhibited at the Royal Show held in Leeds, 1861, and likewise at the London Exhibition, 1862. It had two steam cylinders, six inches in diameter and with eight-inch stroke. The boiler was of the locomotive multi-tubular type, two feet six inches in diameter, and five feet three inches long. It had a working pressure of one hundred and fifty pounds per square inch, the test pressure being three hundred pounds. The locomotive was mounted upon two driving wheels, each four feet in diameter, made of steel, and a leading wheel was three feet in diameter. Seats were provided for nine persons, including the steerer and the fireman. The traveling speed was fifteen miles an hour; and the weight of the carriage, fully loaded, was five tons. Motion was communicated from the crank shaft to the driving axle through spur gearing. The English magazine, Engineering, in an article in June, 1866, said: "This steam carriage, made by Carrett, Marshall & Co., was probably the most remarkable locomotive ever made. True, it did little good for itself as a steam carriage, and its owner at last made a present of it--much as an Eastern prince might send a friend a white elephant--to that enthusiastic amateur, Mr. Frederick Hodges, who christened it the Fly-by-Night, and who did fly, and no mistake, through the Kentish villages when most honest people were in their beds. Its enterprising owner was repeatedly pulled up and fined, and to this day his exploits are remembered against him." Hodges ran the engine eight hundred miles; he had six summonses in six weeks, and one was for running the engine thirty miles an hour. It was afterwards altered to resemble a fire engine and the passengers were equipped like firemen, wearing brass helmets. The device did not deceive the police, and finally the carriage was made over into a real self-moving fire engine. RICHARD TANGYE The steam carriage built by the Tangye Brothers, of England, about 1852, was a simple affair. It had seating capacity in the body for six or eight persons, while three or four more could be accommodated in front. The driver who sat in front had full control of the stop valve and reversing lever, so that the engine could be stopped or reversed by him as occasion required. The speed of twenty miles an hour could be attained, and the engine with its load easily ascended the steepest gradients. Richard Tangye, in his autobiography, speaks of his experience with this carriage in the following terms: "Great interest was manifested in our experiment, and it soon became evident that there was an opening for a considerable business in these engines, and we made our preparations accordingly, but the 'wisdom' of Parliament made it impossible. The squires became alarmed lest their horses should take fright; and although a judge ruled that a horse that would not stand the sight or sound of a locomotive, in these days of steam, constituted a public danger, and that its owner should be punished and not the owner of the locomotive, an act was passed providing that no engine should travel more than four miles an hour on the public roads. Thus was the trade in quick-speed locomotives strangled in its cradle; and the inhabitants of country districts left unprovided with improved facilities for traveling." The Tangye carriage thus driven out of England was sent to India, where it continued to give good service. T. W. COWAN At the London Exhibition of 1862, the Messrs. Yarrow and Hilditch, of Barnsbury, near London, exhibited a steam carriage, designed and made by T. W. Cowan, of Greenwich. Eleven passengers, besides the driver and the fireman, were carried and the vehicle with full load weighed two tons and a half. The boiler, of steel, was a vertical multitubular two feet in diameter and three feet nine inches high. The frame of the carriage was of ash, lined with wrought-iron plates, and to the outside of the bottom sill were two iron foundation plates, to which the cylinders and other parts were attached. The cylinders were five inches in diameter and had nine-inch stroke. CHARLES T. HAYBALL A quick-speed road locomotive was made by Charles T. Hayball, of Lymington, Hants, England, in 1864. The machinery was mounted upon a wrought-iron frame, that was carried upon three wheels. The two driving wheels had an inner and an outer tire, and the space between was filled with wood to reduce noise and lessen the concussion. The two steam cylinders were each four and one-half inches in diameter and with six-inch stroke. Hayball used a vertical boiler, two feet two inches in diameter, and four feet high, working at a pressure of one hundred and fifty pounds. The carriage ran up an incline of one in twelve at sixteen miles an hour, and traveled four miles an hour in fourteen minutes, up hill and down, with ten passengers on board. ISAAC W. BOULTON In August, 1867, Thomas Boulton says: "I ran a small road locomotive constructed by Isaac W. Boulton, of Ashton-under-Lyne, from here through Manchester, Eccles, Warrington, Preston Brook, to Chester, paraded the principal streets of Chester, and returned home, the distance being over ninety miles in one day without a stoppage except for water." Boulton's engine had one cylinder four and one-half inches in diameter, and with nine-inch stroke. The boiler worked at one hundred and thirty pounds pressure per square inch. The driving wheels were five feet in diameter. Two speeds were obtained by means of spur gearing between the crank shaft and the counter shaft. On the Chester trip six persons, and sometimes eight and ten passengers, were carried. ARMSTRONG The virtues of the horseless vehicle early penetrated to India. Many English manufacturers sent carriages there. Some time in 1868, a steam carriage, with two steam cylinders, each three inches in diameter, and with six-inch stroke, was made by Armstrong, of Rawilpindee, Punjab. A separate stop valve was fitted to each cylinder. The boiler was fifteen inches in diameter and three feet high, and worked steam pressure of one hundred pounds per square inch. Twelve miles an hour on the level, and six miles an hour up grade of one in twenty, were made. The driving wheels were three feet in diameter. PIERRE RAVEL Ravel, of France, planned in 1868 a steam vehicle, and about 1870 completed the construction of one at the barracks at Saint-Owen. Then came the declaration of war with Prussia, and the barracks, being within the zone of fortification, the vehicle was lost or destroyed. There is no certainty that it was ever unearthed after peace was declared. L. T. PYOTT Before 1876, a motor vehicle was invented by L. T. Pyott, who was then a foreman with the Baldwin Locomotive Works in Philadelphia. The carriage, which could carry seven persons at the rate of twenty miles an hour, cost about two thousand two hundred dollars, and weighed nearly two tons. It was shown at the Centennial Exposition in Philadelphia in 1876, but was not allowed to run on the streets. A. RICHTER An engineer and mechanician of Neider-Bielan, Oberlaneitz, Germany, Richter secured in 1877 a patent for a vehicle that was propelled by a motor consisting of a stack or battery of elliptic springs horizontally disposed, which were compressed by a charge of powerful powder exploded in what was practically a cannon. The subsequent expansion transmitted the driving effort to the wheels by a rack of gears. The success of this vehicle is not generally known. RAFFARD In 1881, Raffard, a French engineer, made a tricycle and a tram-car that is said to have been the first electric automobile which ran satisfactorily. CHARLES JEANTEAUD It is claimed for Jeanteaud that he built a four-wheeled electric vehicle about 1881, which was changed in 1887 by the addition of an Immisch motor. In 1890 he constructed a three-wheeled steam vehicle for five persons, having the advice and interest of Archdeacon. In June, 1895, at the Paris-Bordeaux race, he entered an electric automobile and established battery relays every twenty-five kilometers, but without success so far as speed was involved in comparison with the gasoline cars. In 1897 he constructed a gasoline phaeton, but his subsequent work has been primarily confined to the electric. SYLVESTER HAYWOOD ROPER As early as 1850, Sylvester Haywood Roper, of Roxbury, Mass., began experimenting with steam for street-vehicle propulsion. In 1882, when he was seventy-three years of age, he fitted a Columbia bicycle with a miniature engine, and with this he could run seventy miles on one charge of fuel. His bicycle weighed one hundred and sixty-five pounds. He engaged in many track events and his record for three runs of one-third of a mile each, was forty-two, thirty-nine and thirty-seven seconds. COPELAND A tandem tricycle with a vertical boiler and a two-cylinder vertical engine was built by Copeland, of Philadelphia, in 1882. Kerosene was used to fire the boiler. It is said that over two hundred of these machines were built. G. BOUTON An ingenious and practical engineer, Bouton made various mechanical devices, but it is claimed that from a clever toy came the associations which have resulted in the now famous firm, DeDion-Bouton, with which he is connected. It is said Compte DeDion saw this toy and on asking for the maker, met Bouton. Thus came the partnership, in 1882, with Bouton and Trepardoux. Bouton made a steam tricycle in 1884, containing the remarkable light and efficient boiler of his invention, which for years remained the most important contribution of the firm to this art. In 1885 a quadricycle was made, and the success attending the runs made with this, in which Merrelle co-operated, was such as to bring forth the personal ideas of DeDion in so strong a manner that Trepardoux and Merrelle severed their connections with the firm. The real beginning of the work of this firm was in 1884, and the several years following saw the production of numerous steam machines, including phaetons, dog carts, and a variety of other types. Even as late as 1897 heavy steam chars-bancs were made by them, and that year also saw their well-known thirty-five-passenger, six-wheeled coach, Pauline, on the streets of Paris--a vehicle which cost over twenty-six thousand francs, and had a thirty-five horse-power steam tractor. This vehicle had been preceded by a somewhat similar one constructed in 1893 on the old idea of a mechanical horse attached to an ordinary 'bus body from which the front wheels had been removed. In 1895, DeDion-Bouton produced their first liquid hydro-carbon engine vehicle--a tricycle with air-cooled motor and dry-battery ignition, which is so well known to everyone in the industry to-day. These were manufactured in large numbers, and were followed by larger gasoline vehicles into which they introduced their engine, namely, a vertical position. In 1899, their three-passenger, four-wheeled vehicle, and in 1900 a six-passenger vehicle, made good reputations. Since then their large factory at Putaux, France, well known under the name of DeDion-Bouton et Cie, has been continually crowded with work on vehicles, and with the manufacture of their motors which are still sold independently to other makers in France, as well as in other countries. In fact the manufacture of engines and parts might be said to be now their main work. COUNT A. DEDION Count DeDion's interest in an ingenious mechanical device constructed by Bouton, led to his backing the enterprise now so well known under his name. His activity in the Automobile Club of France, and in all the sporting events in the past ten years, has in fact brought him into far more prominence than his associate, Bouton. His interest and energy in connection with his company are well known, and though the credit for the mechanical work must undoubtedly be given to Bouton, DeDion is largely responsible for the great success and general prominence of the company. ARMAND PEUGEOT In 1885, and again in 1889, Armand Peugeot, a French inventor and manufacturer, brought up the subject of automobiles, and in 1889 he began to manufacture, using the Daimler motor. His first attention having been given to the motor, he brought out very soon his famous two-parallel cylinder mounted horizontally on the body frame. Originally of the firm of Fils de Peugeot, he severed his connection with that firm, and in 1876 formed the Society of Artisans. In 1898, additional factories were erected at Fives-Lille, and now the concern has works also at Audincourt. The latter works is claimed to be the most extensive automobile manufacturing establishment in the world. Peugeot is a member of many learned societies, was elected an officer of the Academie in 1881, and a Chevalier of the Legion of Honor in 1889. RADCLIFFE WARD Ward commenced his experiments in England about 1886, and built a cab in 1887, which he ran in Brighton with more or less success. A second vehicle, an omnibus, was built by him and run on the streets in London in 1888, and actually covered, all told, five thousand miles. MORS A manufacturer of electrical apparatus, the Mors establishment made a steam vehicle in 1886, and some ten years later began to manufacture gasoline vehicles. MAGNUS VOLK In 1887, Volk built an electrical dog cart which, like that of Ward, was seen on the streets of Brighton. The next year he associated himself with Immisch & Co., and built for the Sultan of Turkey an electrical dog cart. This was claimed to have a radius of fifty miles at ten miles an hour, with seven hundred pounds of battery in twenty-four cells, driving the vehicle by means of a one horse-power motor. BUTLER About the same time that Daimler and Benz were at work, Butler, an Englishman, was studying to make a hydro-carbon engine. He had drawings in 1884 and got out a patent in 1887. He built a tricycle soon after that date. This had two front wheels as steering wheels and a rear wheel driven by a two-cylinder engine. But Butler did not carry his plans further, for, as he wrote in 1890, "the authorities do not countenance its use on roads, and I have abandoned in consequence any further development of it." LE BLANT The steam carriage that Le Blant, of France, built carried nine passengers, and its weight, fuel and water included, was three and one-half tons. The engine was three-cylinder horizontal, and the boiler, a Serpollet instantaneous generator, was placed behind the carriage, the fireman beside it and the driver in front. EMILE DELAHAYE Delahaye, of Tours, associated himself with the firm of Cail in 1870, spending some years in Belgium, but in 1890 the automobile so attracted him as to lead him to the construction of his first vehicle. For ten years he practically adhered to the horizontal engine under the seat, which construction we find him using in 1900. It is worthy of note that to Delahaye is given credit for the practical adaptation of the radiator in the arrangement now generally used in the cooling system. ROGER Roger, of Paris, was the French licensee for Benz, taking up that motor much in the same manner as Panhard & Levassor took up the Daimler. In fact he had such close relations with Benz as to guide the further development of both. To this extent he was doubtless largely responsible for converting Benz to the four-cycle instead of the two-cycle construction, and he is also credited with having brought about the change from the vertical crank shaft to the horizontal in the Benz cars. Making good headway in 1894, he had produced fifty or more machines by 1895, and ran one in the Paris-Bordeaux race of that year. He brought a car to New York in 1896, and took part in the Cosmopolitan race, from New York to Ardsley and return. GEORGES RICHARD In 1893, Georges Richard began cycle manufacturing in a small shop and two years later turned his business into a limited corporation. In 1897, he began the manufacture of automobiles. His motor is a development of the Benz, with ignition improvement. POCHAIN Pochain, in France, built in 1893 a six-seated phaeton with fifty-four cells of battery, which would seem to have been practically the first satisfactory vehicle of its kind. LOUIS KRIEGER Early in the nineties of the last century Krieger made an electric vehicle. About 1894, he introduced his four-passenger hack, converted by substituting an electric fore carriage for the front axle of an ordinary vehicle. He has since developed his electric vehicles in the class of city carriages. A touring car, built for England, called the Powerful, made in 1901 notable records in that country in a long tour through the Isles. The principal work of Krieger, however, has been in the development of front drive and steer construction. DEDETRICH Baron DeDetrich is of the well-known house that claims to have been founded more than one hundred years ago in Luneville, Alsace, and has grown to be one of the greatest works for the manufacture of locomotives and other machinery. In 1880 the concern is said to have employed four thousand men. Its connection with the automobile industry began practically in 1895, when the construction of automobiles on the system of Amédèe Bollèe & Sons was undertaken. With large resources and ability development was naturally rapid, resulting in the production to-day of one of the first-class French makes. DAVID SALOMONS Sir David Salomons, Bart., was born in England, in 1851. He was educated for a short period at University College, London, and afterwards at Caius College, Cambridge, where he was graduated with natural science honors. He is a member of the Institution of Electrical Engineers, where he took leading part for many years on the Council, and served in the positions of honorary treasurer and vice-president. He is a fellow of the Royal Astronomical Society, of the Physical Society of London, and of the Royal Microscopical Society, and an associate of the Institution of Civil Engineers. [Illustration: SIR DAVID SALOMONS] Sir David was one of the first in England to adopt the electric light. This was about the year 1874, when he found it necessary to make the lamps, switches and other apparatus himself, as those were unobtainable at the time; much of the apparatus in general use to-day has been copied from his models. About 1874-5, he constructed a small electrical road carriage, which was in use a short time only, owing to the trouble of re-charging batteries, as no accumulators existed at that period. Devoting himself largely to scientific investigation he is the author of various works on scientific subjects, such as photographic optical formulæ, photography and electrical subjects, his chief work being his three-volume Electric Light Installations, now entering its ninth edition. Of this work, the first volume on Accumulators was for a great many years the only practical work on the subject. He is also the author of many papers read before scientific societies, including the Royal Society and Royal Institution. He is an original member of the Automobile Club of France and of the Automobile Club of Great Britain, being a member of the committee of the former and member of committee and a vice-president of the latter, and is also an ordinary or honorary member of most of the Continental automobile clubs. He was Mayor of Tunbridge Wells, 1894-5, and High Sheriff of Kent in 1881, and is a Magistrate for Kent, Sussex, Middlesex, Westminster and London. The connection of Sir David Salomons with the encouragement and development of self-propelled traffic in the United Kingdom, constitutes one of the most important chapters in the contemporaneous history of the automobile. His first step to secure a favorable public opinion for the legislative measures that he proposed was to have an exhibition of vehicles, which took place at Tunbridge Wells, in October, 1895. As a result of this exhibition and a voluminous correspondence thereafter, the newspapers of Great Britain and many of the members of the Houses of Lords and Commons were brought to see the justice of the measures asked for. Next, the Self-Propelled Traffic Association was organized. Sir David Salomons was elected president and the campaign for Parliamentary action was inaugurated and brilliantly and energetically prosecuted. When the bill came before the Commons and the Lords it was substantially supported, but its provisions received a great deal of discussion. Some amendments, particularly relating to the questions of smoke and petroleum use, were attached to it. In the end, however, the act that was passed was generally satisfactory to all interested in the promotion and protection of self-propelled traffic. It has been said that "there has hardly been an act passed containing more liberal clauses and with more unity of action." Its provisions allow of reasonable travel of all kinds of self-propelled vehicles throughout the Kingdom and the act as a whole is regarded as one of the most notable advances made in this matter during the present generation. LEON BOLLÈE A brother of Amédèe Bollèe, Leon Bollèe has been long interested in the business that bears the family name. In 1896, he brought out a motor cycle that was a type between a cycle and a vehicle. It had two front steering wheels and one front driver. The same type of vehicle has been adopted for light work, such as parcel delivery. JOSEPH GUEDON Guedon made his appearance at Bordeaux, in October, 1897, with a four-wheeled wagonette, which he made under the name of the Decauville. His special construction was claimed to very largely eliminate the vibration of the vehicle, and his success can be fairly judged from the results in the past few years. The Decauville cars have been developed and refined to such a point as to be among the best of the French makes, and now have an international reputation. RENE DE KNYFF De Knyff became an enthusiastic automobilist, and with other gentlemen, sportsmen of the nobility, became a great amateur. He was and is still known as the King of Chauffeurs, having won several of the most important races, driving the Panhard cars to victory. ADOLF CLEMENT Born in 1855. Entirely a self-made man, Clement had experience as a locksmith and served an apprenticeship as a tinsmith. He started and built up a bicycle manufacturing establishment which, in 1894, was considered one of the finest in France. In time this developed into the finest cycle manufactory in that country. It is situated in Levallois, near Paris. In 1899, Clement contracted with Panhard & Levassor to manufacture under their patents, and in 1900 he made a most successful light vehicle of four horse-power. Since then he has developed his automobile factory, and in the past few years has produced competitors for honors in the first class, which are known at home and abroad as the Bayard or Clement-Bayard cars. A. DARRACQ About fifty years of age, Darracq has had an energetic and successful career. He is now president of the Society of Engineers, Paris, and a member of the Legion of Honor. He is best known as an inventor in connection with the automobile industry. Among his inventions are a shaft drive and a beveled gear drive which are now universally used. He originated the idea of placing the operating lever on the steering post and made the first moderate priced automobile in France. He is now the engineer and manager of one of the biggest factories in the world. [Illustration: A. DARRACQ] JAMES GORDON BENNETT So interesting was the sporting side of the automobile movement that it early attracted the attention of James Gordon Bennett. The great runs, or tours, or races commenced in 1891, and continued annually from 1894 on, resulted in the offering of the Bennett trophy for international competition under conditions which may have been suggested by the America yacht cup races. In January, 1900, this was announced in Paris, and the custody of the trophy initially given to the Automobile Club of France as the first and foremost champions of automobiling. Elaborate and excellent rules govern the annual competition for the trophy, and the races are held in the country whose representative has won in the previous year. In this way the first race was in France, as well as the second, and the 1903 race in Ireland, while that of 1904 was held in Germany, but was won by a Frenchman, so that the 1905 race will again be held in the land of the original custodians of the trophy. INDEX Adamson, Daniel, 158 Anderson, James Caleb, 145 Andrews, F., 137 Armstrong, 163 Automobile, Origin and Development of the, 11 Battin, 155 Baynes, John, 129 Bennett, James Gordon, 176 Benz, Carl, 94 Bernhard, Anthony, 154 Blanchard, 121 Blanchard, Thomas, 68 Bollèe, Amedèe, 90 Bollèe, Leon, 174 Bordino, Chevalier, 139 Boulton, Isaac W., 163 Bouton, G., 166 Brown, Samuel, 133 Brunton, William, 127 Burtsall, T., 132 Butler, 169 Carrett, W. O., 159 Cartwright, Edmund, 131 Church, W. H., 87 Clement Adolf, 175 Clive, 139 Copeland, 166 Cowan, T. W., 162 Cugnot, Nicholas Joseph, 31 Daimler, Gottlieb, 95 Dallery, Thomas Charles Auguste, 122 Dance, Charles, 142 Darracq, A., 175 Darwin, Erasmus, 118 Davidson, Robert, 148 Decauville, 174 De Detrich, 171 De Dion, Count A., 167 De Knyff, René, 175 Delahaye, Emile, 170 Dietz, 144 Dudgeon, Richard, 155 Dumbell, John, 126 Du Quet, 126 Edgeworth, Richard Lovell, 120 Evans, Oliver, 38 Farfleur, Stephen, 112 Field, Joshua, 143 Fisher, J. K., 153 Foreword, 5 Fourness, Robert, 123 Genevois, J. H., 126 Gibbs, 141 Goodman, 153 Gordon, David, 56 Griffiths, Julius, 130 Guedon, Joseph, 174 Gurney, Goldsworthy, 64 Hancock, Walter, 71 Harland, 137 Hautsch, Johann, 111 Hayball, Charles T., 162 Heaton, W. G., 148 Hill, F., 150 Holland, T. S., 135 Huygens, Christiaan, 111 Inventors, Pioneer, 29 Investigators, Noted, 105 James, William Henry, 59 James, William T., 77 Jeanteaud, Charles, 165 Johnson, 70 Kestler, J. S., 121 Krieger, Louis, 171 Knyff, René de, 175 Le Blant, 169 Leibnitz, Gottfried Wilhelm von, 115 Lenoir, Jean Joseph Etienne, 89 Levassor, 99 Lough and Messenger, 155 Maceroni, Francis, 78 Mackworth, Humphrey, 115 Marcus, Siegfried, 93 Masurier, 121 Medhurst, George, 124 Messenger, 155 Millichap, G., 144 Moore, Francis, 120 Mors, 169 Murdock, William, 34 Nasmyth, James, 135 Neville, James, 134 Newton, Isaac, 113 Norrgber, 153 Noted Investigators, 105 Ogle, Summers and, 140 Origin and Development of the Automobile, 11 Papin, Denis, 116 Parker, T. W., 133 Pecqueur, 138 Peugeot, Armand, 168 Pioneer Inventors, 29 Planta, 121 Pochain, 171 Pocock, George, 133 Pyott, L. T., 164 Raffard, 165 Ramsey, David, 110 Ravel, Pierre, 164 Read, Nathan, 48 Renault, Louis, 101 Renault, Marcel, 101 Richard, Elié, 114 Richard, Georges, 171 Richter, A., 164 Rickett, Thomas, 156 Roberts, Richard, 82 Robinson, 118 Roger, 170 Roper, Sylvester Haywood, 165 Russell, John Scott, 83 Salomons, Sir David, 172 Selden, George B., 91 Serpollet, Leon, 100 Stirling, 159 Stevin, Simon, 109 Summers and Ogle, 140 Symington, William, 45 Tangye, Richard, 161 Tindall, Thomas, 129 Thompson, R. W., 154 Trevithick, Richard, 50 Vaucauson, 117 Vegelius, 114 Verbiest, Fernando, 112 Viney, James, 138 Vivian, Andrew, 125 Volk, Magnus, 169 Von Leibnitz, Gottfried Wilhelm, 115 Ward, Radcliffe, 168 Watt, James, 122 Wildgosse, Thomas, 110 Yates, 144 
762	----	British Airships: Past, Present and Future by George Whale (Late Major, R.A.F.) CHAPTER I INTRODUCTION CHAPTER II EARLY AIRSHIPS AND THEIR DEVELOPMENT TO THE PRESENT DAY CHAPTER III BRITISH AIRSHIPS BUILT BY PRIVATE FIRMS CHAPTER IV BRITISH ARMY AIRSHIPS CHAPTER V EARLY DAYS OF THE NAVAL AIRSHIP SECTION--PARSEVAL AIRSHIPS, ASTRA-TORRES TYPE, ETC. CHAPTER VI NAVAL AIRSHIPS: THE NON-RIGIDS-- S.S. TYPE COASTAL AND C STAR AIRSHIPS THE NORTH SEA AIRSHIP CHAPTER VII NAVAL AIRSHIPS: THE RIGIDS RIGID AIRSHIP NO. 1 RIGID AIRSHIP NO. 9 RIGID AIRSHIP NO. 23 CLASS RIGID AIRSHIP NO. 23 X CLASS RIGID AIRSHIP NO. 31 CLASS RIGID AIRSHIP NO. 33 CLASS CHAPTER VIII THE WORK OF THE AIRSHIP IN THE WORLD WAR CHAPTER IX THE FUTURE OF AIRSHIPS CHAPTER I INTRODUCTION Lighter-than-air craft consist of three distinct types: Airships, which are by far the most important, Free Balloons, and Kite Balloons, which are attached to the ground or to a ship by a cable. They derive their appellation from the fact that when charged with hydrogen, or some other form of gas, they are lighter than the air which they displace. Of these three types the free balloon is by far the oldest and the simplest, but it is entirely at the mercy of the wind and other elements, and cannot be controlled for direction, but must drift whithersoever the wind or air currents take it. On the other hand, the airship, being provided with engines to propel it through the air, and with rudders and elevators to control it for direction and height, can be steered in whatever direction is desired, and voyages can be made from one place to another--always provided that the force of the wind is not sufficiently strong to overcome the power of the engines. The airship is, therefore, nothing else than a dirigible balloon, for the engines and other weights connected with the structure are supported in the air by an envelope or balloon, or a series of such chambers, according to design, filled with hydrogen or gas of some other nature. It is not proposed, in this book, to embark upon a lengthy and highly technical dissertation on aerostatics, although it is an intricate science which must be thoroughly grasped by anyone who wishes to possess a full knowledge of airships and the various problems which occur in their design. Certain technical expressions and terms are, however, bound to occur, even in the most rudimentary work on airships, and the main principles underlying airship construction will be described as briefly and as simply as is possible. The term "lift" will appear many times in the following pages, and it is necessary to understand what it really means. The difference between the weight of air displaced and the weight of gas in a balloon or airship is called the "gross lift." The term "disposable," or "nett" lift, is obtained by deducting the weight of the structure, cars, machinery and other fixed weights from the gross lift. The resultant weight obtained by this calculation determines the crew, ballast, fuel and other necessities which can be carried by the balloon or airship. The amount of air displaced by an airship can be accurately weighed, and varies according to barometric pressure and the temperature; but for the purposes of this example we may take it that under normal conditions air weighs 75 lb. per 1,000 cubic feet. Therefore, if a balloon of 1,000 cubic feet volume is charged with air, this air contained will weigh 75 lb. It is then manifest that a balloon filled with air would not lift, because the air is not displaced with a lighter gas. Hydrogen is the lightest gas known to science, and is used in airships to displace the air and raise them from the ground. Hydrogen weighs about one-fifteenth as much as air, and under normal conditions 1,000 cubic feet weighs 5 lb. Pursuing our analogy, if we fill our balloon of 1,000 cubic feet with hydrogen we find the gross lift is as follows: 1,000 cubic feet of air weighs 75 lb. 1,000 cubic feet of hydrogen weighs 5 lb. ------ The balance is the gross lift of the balloon 70 lb. It follows, then, that apart from the weight of the structure itself the balloon is 70 lb. lighter than the air it displaces, and provided that it weighs less than 70 lb. it will ascend into the air. As the balloon or airship ascends the density of the air decreases as the height is increased. As an illustration of this the barometer falls, as everyone knows, the higher it is taken, and it is accurate to say that up to an elevation of 10,000 feet it falls one inch for every 1,000 feet rise. It follows that as the pressure of the air decreases, the volume of the gas contained expands at a corresponding rate. It has been shown that a balloon filled with 1,000 feet of hydrogen has a lift of 70 lb. under normal conditions, that is to say, at a barometric pressure of 80 inches. Taking the barometric pressure at 2 inches lower, namely 28, we get the following figures: 1,000 cubic feet of air weighs 70 lb. 1,000 cubic feet of hydrogen weighs 4.67 " --------- 65.33 lb. It is therefore seen that the very considerable loss of lift, 4.67 lb. per 1,000 cubic feet, takes place with the barometric pressure 2 inches lower, from which it may be taken approximately that 1/30 of the volume gross lift and weight is lost for every 1,000 feet rise. From this example it is obvious that the greater the pressure of the atmosphere, as indicated by the barometer, the greater will be the lift of the airship or balloon. Temperature is another factor which must be considered while discussing lift. The volume of gas is affected by temperature, as gases expand or contract about 1/500 part for every degree Fahrenheit rise or fall in temperature. In the case of the 1,000 cubic feet balloon, the air at 30 inches barometric pressure and 60 degrees Fahrenheit weighs 75 lb., and the hydrogen weighs 5 lb. At the same pressure, but with the temperature increased to 90 degrees Fahrenheit, the air will be expanded and 1,000 cubic feet of air will weigh only 70.9 lb., while 1,000 cubic feet of hydrogen will weigh 4.7 lb. The lift being the difference between the weight of the volume of air and the weight of the hydrogen contained in the balloon, it will be seen that with the temperature at 60 degrees Fahrenheit the lift is 75 lb. - 5 lb. = 70 lb., while the temperature, having risen to 90 degrees, the lift now becomes 70.9 lb. - 4.7 lb. = 66.2 lb. Conversely, with a fall in the temperature the lift is increased. We accordingly find from the foregoing observations that at the start of a voyage the lift of an airship may be expected to be greater when the temperature is colder, and the greater the barometric pressure so will also the lift be greater. To put this into other words, the most favourable conditions for the lift of an airship are when the weather is cold and the barometer is high. It must be mentioned that the air and hydrogen are not subject in the same way to changes of temperature. Important variations in lift may occur when the temperature of the gas inside the envelope becomes higher, owing to the action of the sun, than the air which surrounds it. A difference of some 20 degrees Fahrenheit may result between the gas and the air temperatures; this renders it highly necessary that the pilot should by able to tell at any moment the relative temperatures of gas and air, as otherwise a false impression will be gained of the lifting capacity of the airship. The lift of an airship is also affected by flying through snow and rain. A considerable amount of moisture can be taken up by the fabric and suspensions of a large airship which, however, may be largely neutralized by the waterproofing of the envelope. Snow, as a rule, is brushed off the surface by the passage of the ship through the air, though in the event of its freezing suddenly, while in a melting state, a very considerable addition of weight might be caused. There have been many instances of airships flying through snow, and as far as is known no serious difficulty has been encountered through the adhesion of this substance. The humidity of the air may also cause slight variations in lift, but for rough calculations it may be ignored, as the difference in lift is not likely to amount to more than 0.3 lb. per 1,000 cubic feet of gas. The purity of hydrogen has an important effect upon the lift of an airship. One of the greatest difficulties to be contended with is maintaining the hydrogen pure in the envelope or gasbags for any length of time. Owing to diffusion gas escapes with extraordinary rapidity, and if the fabric used is not absolutely gastight the air finds its way in where the gas has escaped. The maximum purity of gas in an airship never exceeds 98 per cent by volume, and the following example shows how greatly lift can be reduced: Under mean atmospheric conditions, which are taken at a temperature of 55 degrees Fahrenheit, and the barometer at 29.5 inches, the lift of 1,000 cubic feet of hydrogen at 98 per cent purity is 69.6 lb. Under same conditions at 80 per cent purity the lift of 1,000 cubic feet of hydrogen is 56.9 lb., a resultant loss of 12.9 lb. per 1,000 cubic feet. The whole of this statement on "lift" can now be condensed into three absolute laws: 1. Lift is directly proportional to barometric pressure. 2. Lift is inversely proportional to absolute temperature. 3. Lift is directly proportional to purity. AIRSHIP DESIGN The design of airships has been developed under three distinct types, the Rigid, the Semi-Rigid, and the Non-Rigid. The rigid, of which the German Zeppelin is the leading example, consists of a framework, or hull composed of aluminium, wood, or other materials from which are suspended the cars, machinery and other weights, and which of itself is sufficiently strong to support its own weight. Enclosed within this structure are a number of gas chambers or bags filled with hydrogen, which provide the necessary buoyancy. The hull is completely encased within a fabric outer cover to protect the hull framework and bags from the effects of weather, and also to temper the rays of the sun. The semi-rigid, which has been exploited principally by the Italians with their Forlanini airships, and in France by Lebaudy, has an envelope, in some cases divided into separate compartments, to which is attached close underneath a long girder or keel. This supports the car and other weights and prevents the whole ship from buckling in the event of losing gas. The semi-rigid type has been practically undeveloped in this country. The non-rigid, of which we may now claim to be the leading builders, is of many varieties, and has been developed in several countries. In Germany the chief production has been that of Major von Parseval, and of which one ship was purchased by the Navy shortly before the outbreak of war. In the earliest examples of this type the car was slung a long way from the envelope and was supported by wires from all parts. This necessitated a lofty shed for its accommodation as the ship was of great overall height; but this difficulty was overcome by the employment of the elliptical and trajectory bands, and is described in the chapter dealing with No. 4. A second system is that of the Astra-Torres. This envelope is trilobe in section, with internal rigging, which enables the car to be slung very close up to the envelope. The inventor of these envelopes was a Spaniard, Senor Torres Quevedo, who manufactured them in conjunction with the Astra Company in Paris. This type of envelope has been employed in this country in the Coastal, C Star, and North Sea airships, and has been found on the whole to give good results. It is questionable if an envelope of streamline shape would not be easier to handle, both in the air and on the landing ground, and at present there are partisans of both types. Thirdly, there is the streamline envelope with tangential suspensions, which has been adopted for all classes of the S.S. airship, and which has proved for its purpose in every way highly satisfactory. Of these three types the rigid has the inherent disadvantage of not being able to be dismantled, if it should become compelled to make a forced landing away from its base. Even if it were so fortunate as to escape damage in the actual landing, there is the practical certainty that it would be completely wrecked immediately any increase occurred in the force of the wind. On the other hand, for military purposes, it possesses the advantage of having several gas compartments, and is in consequence less susceptible to damage from shell fire and other causes. Both the semi-rigid and the non-rigid have the very great advantage of being easily deflated and packed up. In addition to the valves, these ships have a ripping panel incorporated in the envelope which can easily be torn away and allows the gas to escape with considerable rapidity. Innumerable instances have occurred of ships being compelled to land in out-of-the-way places owing to engine failure or other reasons; they have been ripped and deflated and brought back to the station without incurring any but the most trifling damage. Experience in the war has proved that for military purposes the large rigid, capable of long hours of endurances and the small non-rigid made thoroughly reliable, are the most valuable types for future development. The larger non-rigids, with the possible exception of the North Sea, do not appear to be likely to fulfil any very useful function. Airship design introduces so many problems which are not met with in the ordinary theory of structures, that a whole volume could easily be devoted to the subject, and even then much valuable information would have to be omitted from lack of space. It is, therefore, impossible, in only a section of a chapter, to do more than indicate in the briefest manner a few salient features concerning these problems. The suspension of weights from the lightest possible gas compartment must be based on the ordinary principles of calculating the distribution loads as in ships and other structures. In the non-rigid, the envelope being made of flexible fabric has, in itself, no rigidity whatsoever, and its shape must be maintained by the internal pressure kept slightly in excess of the pressure outside. Fabric is capable of resisting tension, but is naturally not able to resist compression. If the car was rigged beneath the centre of the envelope with vertical suspensions it would tend to produce compression in the underside of the envelope, owing to the load not being fully distributed. This would cause, in practice, the centre portion of the envelope to sag downwards, while the ends would have a tendency to rise. The principle which has been found to be most satisfactory is to fix the points of suspension distributed over the greatest length of envelope possible proportional to the lift of gas at each section thus formed. From these points the wires are led to the car. If the car is placed close to the envelope it will be seen that the suspensions of necessity lie at a very flat angle and exert a serious longitudinal compression. This must be resisted by a high internal pressure, which demands a stouter fabric for the envelope and, therefore, increased weight. It follows that the tendency of the envelope to deform is decreased as the distance of the car from the gas compartment is increased. One method of overcoming this difficulty is found by using the Astra-Torres design. As will be seen from the diagram of the North Sea airship, the loads are excellently distributed by the several fans of internal rigging, while external head resistance is reduced to a minimum, as the car can be slung close underneath the envelope. Moreover, the direct longitudinal compression due to the rigging is applied to a point considerably above the axis of the ship. In a large non-rigid many of these difficulties can be overcome by distributing the weight into separate cars along the envelope itself. We have seen that as an airship rises the gas contained in the envelope expands. If the envelope were hermetically sealed, the higher the ship rose the greater would become the internal pressure, until the envelope finally burst. To avoid this difficulty in a balloon, a valve is provided through which the gas can escape. In a balloon, therefore, which ascends from the ground full, gas is lost throughout its upward journey, and when it comes down again it is partially empty or flabby. This would be an impossible situation in the case of the airship, for she would become unmanageable, owing to the buckling of the envelope and the sagging of the planes. Ballonets are therefore fitted to prevent this happening. Ballonets are internal balloons or air compartments fitted inside the main envelope, and were originally filled with air by a blower driven either by the main engines or an auxiliary motor. These blowers were a continual source of trouble, and at the present day it has been arranged to collect air from the slip-stream of the propeller through a metal air scoop or blower-pipe and discharge it into an air duct which distributes it to the ballonets. The following example will explain their functions: An airship ascends from the ground full to 1,000 feet. The ballonets are empty, and remain so throughout the ascent. By the time the airship reaches 1,000 feet it will have lost 1/30th of its volume of gas which will have escaped through the valves. If the ship has a capacity of 300,000 cubic feet it will have lost 10,000 cubic feet of gas. The airship now commences to descend; as it descends the gas within contracts and air is blown into the ballonets. By the time the ground is reached 10,000 cubic feet of air will have been blown into the ballonets and the airship will have retained its shape and not be flabby. On making a second ascent, as the airship rises the air must be let out of the ballonet instead of gas from the envelope, and by the time 1,000 feet is reached the ballonets will be empty. To ensure that this is always done the ballonet valves are set to open at less pressure than the gas valves. It therefore follows in the example under consideration that it will not be necessary to lose gas during flight, provided that an ascent is not made over 1,000 feet. Valves are provided to prevent the pressure in the envelope from exceeding a certain determined maximum and are fitted both to ballonets and the gaschamber. They are automatic in action, and, as we have said, the gas valve is set to blow off at a pressure in excess of that for the air valve. In rigid airships ballonets are not provided for the gasbags, and as a consequence a long flight results in a considerable expenditure of gas. If great heights are required to be reached, it is obvious that the wastage of gas would be enormous, and it is understood that the Germans on starting for a raid on England, where the highest altitudes were necessary, commenced the flight with the gasbags only about 60 per cent full. To stabilize the ship in flight, fins or planes are fitted to the after end of the envelope or hull. Without the horizontal planes the ship will continually pitch up and down, and without the vertical planes it will be found impossible to keep the ship on a straight course. The planes are composed of a framework covered with fabric and are attached to the envelope by means of stay wires fixed to suitable points, in the case of non-rigid ships skids being employed to prevent the edge of the plane forcing its way through the surface of the fabric. The rudder and elevator flaps in modern practice are hinged to the after edges of the planes. The airship car contains all instruments and controls required for navigating the ship and also provides a housing for the engines. In the early days swivelling propellers were considered a great adjunct, as with their upward and downward thrust they proved of great value in landing. Nowadays, owing to greater experience, landing does not possess the same difficulty as in the past, and swivelling propellers have been abandoned except in rigid airships, and even in the later types of these they have been dispensed with. Owing to the great range of an airship a thoroughly reliable engine is a paramount necessity. The main requirements are--firstly, that it must be capable of running for long periods without a breakdown; secondly, that it must be so arranged that minor repairs can be effected in the air; and thirdly, that economy of oil and fuel is of far greater importance to an airship than the initial weight of the engine itself. HANDLING AND FLYING OF AIRSHIPS The arrangements made for handling airships on the ground and while landing, and also for moving them in the open, provide scope for great ingenuity. An airship when about to land is brought over the aerodrome and is "ballasted up" so that she becomes considerably lighter than the air which she displaces. The handling party needs considerable training, as in gusty weather the safety of the ship depends to a great extent upon its skill in handling her. The ship approaches the handling party head to wind and the trail rope is dropped; it is taken by the handling party and led through a block secured to the ground and the ship is slowly hauled down. When near the ground the handling party seize the guys which are attached to the ship at suitable points, other detachments also support the car or cars, as the case may be, and the ship can then be taken into the shed. In the case of large airships the size of the handling party has to be increased and mechanical traction is also at times employed. As long as the airship is kept head to wind, handling on the ground presents little difficulty; on many occasions, however, unless the shed is revolving, as is the case on certain stations in Germany, the wind will be found to be blowing across the entrance to the shed. The ship will then have to be turned, and during this operation, unless great discretion is used, serious trouble may be experienced. Many experiments have been and are still being conducted to determine the best method of mooring airships in the open. These will be described and discussed at some length in the chapter devoted to the airship of the future. During flight certain details require attention, and carelessness on the pilot's part, even on the calmest of days, may lead to disaster. The valves and especially the gas valves should be continually tested, as on occasions they have been known to jam, and the loss of gas has not been discovered until the ship had become unduly heavy. Pressure should be kept as constant as possible. Most airships work up to 30 millimetres as a maximum and 15 millimetres as a minimum flying pressure. During a descent the pressure should be watched continuously, as it may fall so low as to cause the nose to blow in. This will right itself when the speed is reduced or the pressure is raised, but there is always the danger of the envelope becoming punctured by the bow stiffeners when this occurs. HOUSING ACCOMMODATION FOR AIRSHIPS, ETC. During the early days of the war, when stations were being equipped, the small type of airship was the only one we possessed. The sheds to accommodate them were constructed of wood both for cheapness and speed of construction and erection. These early sheds were all of very similar design, and were composed of trestles with some ordinary form of roof-truss. They were covered externally with corrugated sheeting. The doors have always been a source of difficulty, as they are compelled to open for the full width of the shed and have to stand alone without support. They are fitted with wheels which run on guide rails, and are opened by means of winches and winding gear. The later sheds built to accommodate the rigid airship are of much greater dimensions, and are constructed of steel, but otherwise are of much the same design. The sheds are always constructed with sliding doors at either end, to enable the ship to be taken out of the lee end according to the direction of the wind. It has been the practice in this country to erect windscreens in order to break the force of the wind at the mouth of the shed. These screens are covered with corrugated sheeting, but it is a debatable point as to whether the comparative shelter found at the actual opening of the shed is compensated for by the eddies and air currents which are found between the screens themselves. Experiments have been carried out to reduce these disturbances, in some cases by removing alternate bays of the sheeting and in other cases by substituting expanded metal for the original corrugated sheets. It must be acknowledged that where this has been done, the airships have been found easier to handle. At the outbreak of war, with the exception of a silicol plant at Kingsnorth, now of obsolete type, and a small electrolytic plant at Farnborough, there was no facility for the production of hydrogen in this country for the airship service. When the new stations were being equipped, small portable silicol plants were supplied capable of a small output of hydrogen. These were replaced at a later date by larger plants of a fixed type, and a permanent gas plant, complete with gasholders and high pressure storage tanks was erected at each station, the capacity being 5,000 or 10,000 cubic feet per hour according to the needs of the station. With the development of the rigid building programme, and the consequent large requirements of gas, it was necessary to reconsider the whole hydrogen situation, and after preliminary experimental work it was decided to adopt the water gas contact process, and plants of this kind with a large capacity of production were erected at most of the larger stations. At others electrolytic plants were put down. Hydrogen was also found to be the bye-product of certain industries, and considerable supplies were obtained from commercial firms, the hydrogen being compressed into steel cylinders and dispatched to the various stations. Before concluding this chapter, certain words must be written on parachutes. A considerable controversy raged in the press and elsewhere a few months before the cessation of hostilities on the subject of equipping the aeroplane with parachutes as a life-saving device. In the airship service this had been done for two years. The best type of parachute available was selected, and these were fitted according to circumstances in each type of ship. The usual method is to insert the parachute, properly folded for use, in a containing case which is fastened either in the car or on the side of the envelope as is most convenient. In a small ship the crew are all the time attached to their parachutes and in the event of the ship catching fire have only to jump overboard and possess an excellent chance of being saved. In rigid airships where members of the crew have to move from one end of the ship to the other, the harness is worn and parachutes are disposed in the keel and cars as are lifebuoys in seagoing vessels. Should an emergency arise, the nearest parachute can be attached to the harness by means of a spring hook, which is the work of a second, and a descent can be made. It is worthy of note that there has never been a fatal accident or any case of a parachute failing to open properly with a man attached. The material embodied in this chapter, brief and inadequate as it is, should enable the process of the development of the airship to be easily followed. Much has been omitted that ought by right to have been included, but, on the other hand, intricate calculations are apt to be tedious except to mathematicians, and these have been avoided as far as possible in the following pages. CHAPTER II EARLY AIRSHIPS AND THEIR DEVELOPMENT TO THE PRESENT DAY The science of ballooning had reached quite an advanced stage by the middle of the eighteenth century, but the construction of an airship was at that time beyond the range of possibility. Discussions had taken place at various times as to the practicability of rendering a balloon navigable, but no attempts had been made to put these points of argument to a practical test. Airship history may be said to date from January 24th, 1784. On that day Brisson, a member of the Academy in Paris, read before that Society a paper on airships and the methods to be utilized in propelling them. He stated that the balloon, or envelope as it is now called, must be cylindrical in shape with conical ends, the ratio of diameter to length should be one to five or one to six and that the smallest cross-sectional area should face the wind. He proposed that the method of propulsion should be by oars, although he appeared to be by no means sanguine if human strength would be sufficient to move them. Finally, he referred to the use of different currents of the atmosphere lying one above the other. This paper caused a great amount of interest to be taken in aeronautics, with the result that various Frenchmen turned their attention to airship design and production. To France must be due the acknowledgment that she was the pioneer in airship construction and to her belongs the chief credit for early experiments. At a later date Germany entered the lists and tackled the problems presented with that thoroughness so characteristic of the nation. It is just twenty-one years ago since Count Zeppelin, regardless of public ridicule, commenced building his rigid airships, and in that time such enormous strides were made that Germany, at the outbreak of the war, was ahead of any other country in building the large airship. In 1908 Italy joined the pioneers, and as regards the semi-rigid is in that type still pre-eminent. Great Britain, it is rather sad to say, adopted the policy of "wait and see," and, with the exception of a few small ships described in the two succeeding chapters, had produced nothing worthy of mention before the outbreak of the great European war. She then bestirred herself, and we shall see later that she has produced the largest fleet of airships built by any country and, while pre-eminent with the non-rigid, is seriously challenging Germany for the right to say that she has now built the finest rigid airship. FRANCE To revert to early history, in the same year in which Brisson read his paper before the Academy, the Duke of Chartres gave the order for an airship to the brothers Robert, who were mechanics in Paris. This ship was shaped like a fish, on the supposition that an airship would swim through the air like a fish through water. The gas-chamber was provided with a double envelope, in order that it might travel for a long distance without loss of gas. The airship was built in St. Cloud Park; in length it was 52 feet with a diameter of 82 feet, and was ellipsoidal in shape with a capacity of 30,000 cubic feet. Oars were provided to propel it through the air, experiments having proved that with two oars of six feet diameter a back pressure of 90 lb. was obtained and with four oars 140 lb. On July 6th in the same year the first ascent was made from St. Cloud. The passengers were the Duke of Chartres, the two brothers Robert and Colin-Hulin. No valves having been fitted, there was no outlet for the expansion of gas and the envelope was on the point of bursting, when the Duke of Chartres, with great presence of mind, seized a pole and forced an opening through both the envelopes. The ship descended in the Park of Meudon. On September 19th the airship made a second ascent with the same passengers as before, with the exception of the Duke. According to the report of the brothers Robert, they succeeded in completing an ellipse and then travelled further in the direction of the wind without using the oars or steering arrangements. They then deviated their course somewhat by the use of these implements and landed at Bethune, about 180 miles distant from Paris. In those days it was considered possible that a balloon could be rendered navigable by oars, wings, millwheels, etc., and it was not until the last decades of the nineteenth century, when light and powerful motors had been constructed, that the problem became really practical of solution. During the nineteenth century several airships were built in France and innumerable experiments were carried out, but the vessels produced were of little real value except in so far as they stimulated their designers to make further efforts. Two of these only will be mentioned, and that because the illustrations show how totally different they were from the airship of to-day. In 1834 the Compte de Lennox built an airship of 98,700 cubic feet capacity. It was cylindrical in form with conical ends, and is of interest because a small balloon or ballonet, 7,050 cubic feet contents, was placed inside the larger one for an air filling. A car 66 feet in length was rigged beneath the envelope by means of ropes eighteen inches long. Above the car the envelope was provided with a long air cushion in connection with a valve. The intention was by compression of the air in the cushion and the inner balloon, to alter the height of the airship, in order to travel with the most favourable air currents. The motive power was 20 oar propellers worked by men. This airship proved to be too heavy on completion to lift its own weight, and was destroyed by the onlookers. The next airship, the Dupuy de Lome, is of interest because the experiments were carried out at the cost of the State by the French Government. This ship consisted of a spindle-shaped balloon with a length of 112 feet, diameter of 48 1/2 feet and a volume of 121,800 cubic feet. An inner air balloon of 6,000 cubic feet volume was contained in the envelope. The method of suspension was by means of diagonal ropes with a net covering. A rudder in the form of a triangular sail was fitted beneath the envelope and at the after part of the ship. The motive power was double-winged screws 29 feet 6 inches diameter, to be worked by four to eight men. On her trials the ship became practically a free balloon, an independent velocity of about six miles per hour being achieved and deviation from the direction of the wind of ten degrees. At the close of the nineteenth century Santos-Dumont turned his attention to airships. The experiments which he carried out marked a new epoch and there arose the nucleus of the airship as we know it to-day. Between the years 1898 and 1905 he had in all built fourteen airships, and they were continually improved as each succeeding one made its appearance. In the last one he made a circular flight; starting from the aerodrome of the aero club, he flew round the Eiffel Tower and back to the starting point in thirty-one minutes on October 19th, 1902. For this feat the Deutsch prize was awarded to him. The envelopes he used were in design much nearer approach to a streamline form than those previously adopted, but tapered to an extremely fine point both at the both and stem. For rigging he employed a long nacelle, in the centre of which was supported the car, and unusually long suspensions distributed the weight throughout practically the entire length of the envelope. To the name of Santos-Dumont much credit is due. He may be regarded as the originator of the airship for pleasure purposes, and by his success did much to popularize them. He also was responsible to a large extent for the development and expansion of the airship industry in Paris. At a little later date, in 1902 to be precise, the Lebaudy brothers, in conjunction with Julliot, an engineer, and Surcoup, an aeronaut, commenced building an airship of a new type. This ship was a semirigid and was of a new shape, the envelope resembling in external appearance a cigar. In length it was 178 feet with a diameter of 30 feet and the total capacity was 64,800 cubic feet. This envelope was attached to a rigid elliptical keel-shaped girder made of steel tubes, which was about a third of the length of the ship. The girder was covered with a shirting and intended to prevent the ship pitching and rolling while in flight. A horizontal rudder was attached to the under side of this girder, while right aft a large vertical rudder was fixed. A small car was suspended by steel rods at a distance of 17 feet 9 inches from the girder, with a framework built up underneath to absorb the shock on landing. A 35 horse-power Daimler-Mercedes motor, weighing some 800 lb. without cooling water and fuel, drove two twin-bladed propellers on either side of the car. In the year 1903 a number of experimental flights were made with this ship and various details in the construction were continually introduced. The longest flight was 2 hours 46 minutes. Towards the end of that year, while a voyage was being made from Paris to Chalais Meudon, the airship came in contact with a tree and the envelope was badly torn. In the following year it was rebuilt, and the volume was slightly increased with fixed and movable planes added to increase the stability. After several trips had been made, the airship again on landing came in contact with a tree and was burst. The ship was rebuilt and after carrying out trials was purchased by the French Army. The Lebaudy airship had at that time been a distinct success, and in 1910 one was purchased for the British Government by the readers of the Morning Post. In the ten-ton Lebaudy the length of the keel framework was greatly extended, and ran for very nearly the full length of the envelope. The disadvantage of this ship was its slowness, considering its size and power, and was due to the enormous resistance offered by the framework and rigging. Airships known as the "Clement-Bayard" were also built about this time. They were manufactured by the Astra Company in conjunction with Monsieur Clement, a motor engineer. In later days vessels were built by the Astra Company of the peculiar design introduced by Senor Torres. These ships, some of which were of considerable size, were highly successful, and we became purchasers at a later date of several. The Zodiac Company also constructed a number of small ships which were utilized during the war for anti-submarine patrol. It cannot be said, however, that the French have fulfilled their early promise as airship designers, the chief reason for this being that the airship is peculiarly suitable for work at sea and the French relied on us to maintain the commerce routes on the high seas and concentrated their main efforts on defeating the Germans in the field, in which as all the world acknowledges they were singularly successful and hold us under an eternal obligation. GERMANY The progress and development of the airship in Germany must now be considered; it will be seen that, although the production of satisfactory ships was in very few hands, considerable success attended their efforts in the early days of the twentieth century. In 1812, Leppig built an airship at the cost of the State at Woronzowo in Russia. This was of the shape of a fish with a rigid framework beginning at the height of the longitudinal axis. The lower keel-shaped part of the same formed the car. Two fans were attached to the sides and a tail piece was provided behind to act as a rudder. The ship was inflated, but structural damage occurred during this operation and rendered it incapable of flight. In 1836, Georg Rebenstein, of Nurnburg, was considering the use of the fall of inclined planes to obtain horizontal motion. Nothing of importance was produced until a much later date, when in 1885 M. Wolf constructed an envelope of 26,500 cubic feet. An engine and propeller were fixed in a triangular framework in front of the airship, supported by the steam pipe of a steam engine fixed under the body of the envelope. The framework lacked rigidity, and the envelope tore during inflation and the airship failed to ascend. In the following year Dr. Woelfert, of Berlin, produced a cigar-shaped envelope, to which was attached rigidly a long bamboo framework containing the car. An 8 horse-power benzine Daimler motor drove a twin-bladed aluminium propeller, and another propeller for vertical movement was provided beneath the car. Four trial flights were attempted, but on each occasion the motor gave unsatisfactory results, and Woelfert sought to improve it with a benzine vaporizer of his own pattern. This improvement was not a success, as during the last flight an explosion took place and both Woelfert and an aeronaut named Knabe, who was accompanying him, were killed. In 1906, Major von Parseval experimented, in Berlin, with a non-rigid type of airship. His first ship had a volume of 65,200 cubic feet, but owing to his system of suspensions, the car hung 27 feet 6 inches below the envelope. A Daimler engine was used, driving a four-bladed propeller. Owing to the great overall height of this ship, experiments were made to determine a system of rigging, enabling the car to be slung closer to the envelope, and in later types the elliptical rigging girdle was adopted. His later ships were of large dimensions and proved very satisfactory. About the same time Major Gross also built airships for the German aeronautical battalion. It is, however, the rigid airship that has made Germany famous, and we must now glance at the evolution of these ships with which we became so familiar during the war. The first rigid airship bearing any resemblance to those of the present day was designed by David Schwartz, and was built in St. Petersburg in 1893. It was composed of aluminium plates riveted to an aluminium framework. On inflation, the frame-work collapsed and the ship was unusable. In 1895 he designed a second rigid airship, which was built in Berlin by Messrs. Weisspfennig and Watzesch. The hull framework was composed of aluminium and was 155 feet long, elliptical in cross section, giving a volume of 130,500 cubic feet. It was pointed in front and rounded off aft. The car, also constructed of the same material, was rigidly attached to the hull by a lattice framework, and the whole hull structure was covered in with aluminium sheeting. A 12 horse-power Daimler benzine motor was installed in the car, driving through the medium of a belt twin aluminium screw propellers; no rudders were supplied, the steering being arranged by means of a steering screw placed centrally to the ship above the top of the car. Inflation took place at the end of 1897 by a method of pressing out air-filled fabric cells which were previously introduced into the hull. This operation took three and a half hours. On the day of the first flight trials there was a fresh wind of about 17 miles per hour. The airship ascended into the air, but, apparently, could make little headway against the wind. During the trip the driving-belt became disengaged from the propellers and the ship drifted at the mercy of the wind, but sustained little damage on landing. After being deflated, the hull began to break up under the pressure of the wind and was completely destroyed by the vandalism of the spectators. In 1898 Graf F. von Zeppelin, inspired by the example of Schwartz, and assisted by the engineers Kober and Kubler, conceived the idea of constructing a rigid airship of considerable dimensions. For this purpose a floating shed was built on Lake Constance, near to Friedrichshafen. The hull was built of aluminium lattice-work girders, and had the form of a prism of twenty-four surfaces with arch-shaped ends. In length it was 420 feet, with a diameter of 38 feet 6 inches, and its capacity was 400,000 cubic feet. The longitudinal framework was divided by a series of rings, called transverse frames, into seventeen compartments containing fabric gasbags. The transverse frames were fitted with steel wire bracings, both radial and chord, and to strengthen the whole a triangular aluminium keel of lattice work was used. A vertical and horizontal rudder were fitted to the forward portion of the ship, and aft another vertical rudder. The whole exterior of the ship was fitted with a fabric outer cover. Two aluminium cars, each about 20 feet long, were rigidly attached to the framework of the hull. Each car was furnished with a 16 horse-power Daimler engine, driving two four-bladed screw propellers of aluminium sheeting. These propellers were situated on the side of the hull at the centre of resistance. The transmission was supplied by steel tubes with universal cross joints through the medium of bevel gears. Reversible driving arrangements were installed in the cars in order that the ship could be driven backwards and forwards. Electric bells, telegraphs, and speaking tubes were also fitted, and it can be seen that for general arrangements this airship was a long way ahead of any built at that date. The first flight was made on July 2nd, 1900. The ship attained a speed of 17 per hour, and the numerous technical details stood the tests well. The stability was considered sufficient, and the height of flight could be altered by the horizontal rudder. The landing on the water was accomplished without difficulty, and could be regarded as free from danger. The faults requiring remedy were, firstly, the upper cross stays, which buckled in flight owing to insufficient strength for the length of the hull; secondly, the gasbags were not sufficiently gastight and, thirdly, the power of the engines were not sufficient for such a heavy ship. This airship was broken up in 1902. In 1905 the second ship of the series was completed. She was of nearly the same size as the previous ship, but the workmanship was much superior. Increased engine-power was also supplied, as in this instance two 85 horse-power Mercedes engines were fitted. This ship was destroyed by a storm while landing during the next year. The third ship, which was completed in 1906, was the first Zeppelin airship acquired by the Government, and lasted for a considerable time, being rebuilt twice, first in 1908 and again in 1911. She was slightly larger than the previous two. The building was continued, and up to the outbreak of war no fewer than twenty-five had been completed. It is impossible, in the space at our disposal, to trace the career of all of them. Several came to an untimely end, but as the years went by each succeeding ship proved more efficient, and the first ship which was delivered to the Navy performed the notable flight of thirty-one hours. To revert, for a moment, once more to the earlier ships--the fourth was wrecked and burned at Echterdingen in the same year in which she was completed. The fifth, which was the second military airship, was fitted with two 110 horse-power engines and also came to a tragic end, being destroyed by wind at Weilberg in 1910, and the following ship was burnt at Baden in the same year. The seventh ship was the first passenger airship of the series, and was known as the Deutschland. By this time the capacity had increased to 536,000 cubic feet, and she was propelled by three 120 horse-power engines. She also fell a victim to the wind, and was wrecked in the Teutoberg Forest in 1910; and yet another was destroyed in the following year at Dusseldorf. The tenth ship to be completed was the passenger ship Schwaben; her capacity was 636,500 cubic feet, and she had three 150 horse-power engines. This ship carried out her first flight in June, 1911, and was followed four months later by the Victoria Luise. The fourth passenger airship was known as the Hansa. These three ships were all in commission at the outbreak of war. The first naval airship, L 1, mentioned above, was larger than any of these. The total length was 525 feet, diameter 50 feet, and cubic contents 776,000 cubic feet. Her hull framework in section formed a regular polygon of seventeen sides, and was built up of triangular aluminium girders. The gasbags were eighteen in number. This ship was fitted with three 170 horse-power Maybach engines, which were disposed as follows--one in the forward car, driving two two-bladed propellers; two in the after car, each driving a single four-bladed propeller. For steering purposes she had six vertical and eight horizontal planes. The total lift was 27 tons, with a disposable lift of 7 tons. Her speed was about 50 miles per hour, and she could carry fuel for about 48 hours. Her normal crew consisted of fourteen persons, including officers. It will probably be remembered that the military Zeppelin Z III was compelled to make a forced landing in France. This ship was of similar construction to L 1, but of smaller volume, her capacity being 620,000 cubic feet. A trial flight was being carried out, and while above the clouds the crew lost their bearings. Descending they saw some French troops and rose again immediately. After flying for four hours they thought they must be safely over the frontier and, running short of petrol, made a landing--not knowing that they were still in France until too late. The airship was taken over by the French authorities. Until the year 1916 the Zeppelin may be considered to have passed through three stages of design. Of the twenty-five ships constructed before the war, twenty-four were of the first type and one of the second. Each type possessed certain salient features, which, for simplicity, will be set out in the form of a tabulated statement, and may be useful for comparison when our own rigid airships are reviewed. Stage 1. Long parallel portion of hull with bluff nose and tail. External keel with walking way. Box rudders and elevators. Two cars. Four wing propellers. Stage 2. Long parallel portion of hull with bluff nose, tail portion finer than in Stage I Internal keel walking way. Box rudders and elevators. Three cars, foremost for control only. Four wing propellers. Stage 3. Shorter parallel portion of hull framework, bluff nose and tapering tail. Internal keel walking way. Balanced monoplane rudders and elevators. Three cars, foremost for control only. Two foremost cars close together and connected by a canvas joint to look like one car. Four engines and four propellers. One engine in forward car driving pusher propeller. Three engines in after car driving two wing and one pusher propeller. To the second stage belongs naval airship L 2, which was destroyed by fire a month after completion in 1913. In 1916 a fourth stage made its appearance, of which the first ship was L 30, completed in May, and to which the ill-fated L 33 belonged. This type is known as the super-Zeppelin, and has been developed through various stage until L 70, the latest product before the armistice. In this stage the following are its main features: Stage 4. Short parallel portion of hull, long rounded bow and long tapering stern. In all respects a good streamline shape. Internal keel walking way. Balanced monoplane rudders and elevators. Five cars. Two forward (combined as in Stage 3), one aft, and two amidships abreast. Six engines and six propellers. The after one of the forecar and the sidecars each contain one engine driving direct a pusher propeller. The after car contains three engines, two of which drive two wing propellers; the third, placed aft, drives direct a pusher propeller. In this stage the type of girders was greatly altered. A company known as the Schutte-Lanz Company was also responsible for the production of rigid airships. They introduced a design, which was a distinct departure from Zeppelin or anyone else. The hull framework was composed of wood, the girders being built up of wooden sections. The shape of these ships was much more of a true streamline than had been the Zeppelin practice, and it was on this model that the shape of the super-Zeppelin was based. These ships proved of use and took part in raids on this country, but the Company was taken over by the Government and the personnel was amalgamated with that engaged on Zeppelin construction during the war. ITALY In 1908, Italy, stimulated by the progress made by other continental nations, commenced experimental work. Three types were considered for a commencement, the P type or Piccolo was the first effort, then followed the M type, which signifies "medium sized," and also the semirigid Forlanini. In the Forlanini type the envelope is divided into several compartments with an internal rigid keel and to-day these ships are of considerable size, the most modern being over 600,000 cubic feet capacity. During the war, Italian airships were developed on entirely dissimilar lines to those in other countries. Both we and our Allies, and to a great extent the Germans, employed airships exclusively for naval operations; on the other hand, the Italian ships were utilized for bombing raids in conjunction with military evolutions. For this reason height was of primary importance and speed was quite a secondary consideration, owing to the low velocity of prevailing winds in that country. Flights were never of long duration compared with those carried out by our airships. Height was always of the utmost importance, as the Italian ships were used for bombing enemy towns and must evade hostile gunfire. For this reason weight was saved in every possible manner, to increase the height of the "ceiling." In addition to the types already mentioned, three other varieties have been constructed since the war--the Usuelli D.E. type and G class. The G class was a rigid design which has not been proceeded with, and, with this single exception, all are of a semirigid type in which an essentially non-rigid envelope is reinforced by a metal keel. In the Forlanini and Usuelli types the keel is completely rigid and assists in maintaining the shape of the envelopes, and in the Forlanini is enclosed within the envelope. In the other types the keel is in reality a chain of rigid links similar to that of a bicycle. The form of the envelope is maintained by the internal pressure and not by the keel, but the resistance of the latter to compression enables a lower pressure to be maintained than would be possible in a purely non-rigid ship. The M type ship is of considerable size, the P smaller, while the D.E. is a small ship comparable to our own S.S. design. The review of these three countries brings the early history of airships to a conclusion. Little of importance was done elsewhere before the war, though Baldwin's airship is perhaps worthy of mention. It was built in America in 1908 by Charles Baldwin for the American Government. The capacity of the envelope was 20,000 cubic feet, she carried a crew of two, and her speed was 16 miles per hour. She carried out her trial flight in August, 1908, and was accepted by the American military authorities. During the war both the naval and military authorities became greatly interested in airships, and purchased several from the French and English. In addition to this a ship in design closely resembling the S.S. was built in America, but suffered from the same lack of experience which we did in the early days of airship construction. We must now see what had been happening in this country in those fateful years before the bombshell of war exploded in our midst. CHAPTER III BRITISH AIRSHIPS BUILT BY PRIVATE FIRMS It has been shown in the previous chapter that the development of the airship had been practically neglected in England prior to the twentieth century. Ballooning had been carried out both as a form of sport and also by the showman as a Saturday afternoon's sensational entertainment, with a parachute descent as the piece de resistance. The experiments in adapting the balloon into the dirigible had, however, been left to the pioneers on the Continent. PARTRIDGE'S AIRSHIP It appears that in the nineteenth century only one airship was constructed in this country, which proved to be capable of ascending into the air and being propelled by its own machinery. This airship made its appearance in the year 1848, and was built to the designs of a man named Partridge. Very little information is available concerning this ship. The envelope was cylindrical in shape, tapering at each end, and was composed of a light rigid framework covered with fabric. The envelope itself was covered with a light wire net, from which the car was suspended. The envelope contained a single ballonet for regulating the pressure of the gas. Planes, which in design more nearly resembled sails, were used for steering purposes. In the car, at the after end, were fitted three propellers which were driven by compressed air. Several trips of short duration were carried out in this airship, but steering was never successfully accomplished owing to difficulties encountered with the planes, and, except in weather of the calmest description, she may be said to have been practically uncontrollable. HUGH BELL'S AIRSHIP In the same year, 1848, Bell's airship was constructed. The envelope of this ship was also cylindrical in shape, tapering at each end to a point, the length of which was 56 feet and the diameter 21 feet 4 inches. A keel composed of metal tubes was attached to the underside of the envelope from which the car was suspended. On either side of the car screw propellers were fitted to be worked by hand. A rudder was attached behind the car. It was arranged that trials should be carried out in the Vauxhall Gardens in London, but these proved fruitless. BARTON'S AIRSHIP In the closing years of the nineteenth century appeared the forerunners of airships as they are to-day, and interest was aroused in this country by the performances of the ships designed by Santos-Dumont and Count Zeppelin. From now onwards we find various British firms turning their attention to the conquest of the air. In 1903 Dr. Barton commenced the construction of a large non-rigid airship. The envelope was 176 feet long with a height of 43 feet and a capacity of 235,000 cubic feet; it was cylindrical in shape, tapering to a point at each end. Beneath the whole length of the cylindrical portion was suspended a bamboo framework which served as a car for the crew, and a housing for the motors supplying the motive power of the ship. This framework was suspended from the envelope by means of steel cables. Installed in the car were two 50 horse-power Buchet engines which were mounted at the forward and after ends of the framework. The propellers in themselves were of singular design, as they consisted of three pairs of blades mounted one behind the other. The were situated on each side of the car, two forward and two aft. The drive also include large friction clutches, and each engine was under separate control. To enable the ship to be trimmed horizontally, water tanks were fitted at either end of the framework, the water being transferred from one to the other as was found necessary. A series of planes was mounted at intervals along the framework to control the elevation of the ship. This ship was completed in 1905 and was tried at the Alexandra Palace in the July of that year. She, unfortunately, did not come up to expectations, owing to the difficulty in controlling her, and during the trial flight she drifted away and was destroyed in landing. WILLOWS No. 1 From the year 1905 until the outbreak of war Messrs. Willows & Co. were engaged on the construction of airships of a small type, and considerable success attended their efforts. Each succeeding ship was an improvement on its predecessor, and flights were made which, in their day, created a considerable amount of interest. In 1905 their first ship was completed. This was a very small non-rigid of only 12,500 cubic feet capacity. The envelope was made of Japanese silk, cylindrical in shape, with rather blunt conical ends. A long nacelle or framework, triangular in section and built up of light steel tubes, was suspended beneath the envelope by means of diagonally crossed suspensions. A 7 horse-power Peugeot engine was fitted at the after end of the nacelle which drove a 10-feet diameter propeller. In front were a pair of swivelling tractor screws for steering the ship in the vertical and horizontal plane. No elevators or rudders were fixed to the ship. WILLOWS No. 2 The second ship was practically a semi-rigid. The envelope was over twice the capacity of the earlier ship, being of 29,000 cubic feet capacity. This envelope was attached to a keel of bamboo and steel, from which was suspended by steel cables a small car. At the after end of the keel was mounted a small rudder for the horizontal steering. For steering in the vertical plane two propellers were mounted on each side of the car, swivelling to give an upward or downward thrust. A 30 horse-power J.A.P. engine was fitted in this case. Several successful flights were carried out by this ship, of which the most noteworthy was from Cardiff to London. WILLOWS No. 3 No. 2, having been rebuilt and both enlarged and improved, became known as No. 3. The capacity of the envelope, which was composed of rubber and cotton, was increased to 32,000 cubic feet, and contained two ballonets. The gross lift amounted to about half a ton. As before, a 30 horse-power J.A.P. engine was installed, driving the swivelling propellers. These propellers were two-bladed with a diameter of 61 feet. The maximum speed was supposed to be 25 miles per hour, but it is questionable if this was ever attained. This ship flew from London to Paris, and was the first British-built airship to fly across the Channel. WILLOWS No. 4 The fourth ship constructed by this firm was completed in 1912, and was slightly smaller than the two preceding ships. The capacity of the envelope in this instance was reduced to 24,000 cubic feet, but was a much better shape, having a diameter of 20 feet, which was gradually tapered towards the stern. A different material was also used, varnished silk being tried as an experiment. The envelope was attached to a keel on which was mounted the engine, a 35 horse-power Anzani, driving two swivelling four-bladed propellers. From the keel was suspended a torpedo-shaped boat car in which a crew of two was accommodated. Originally a vertical fin and rudder were mounted at the stern end of the keel, but these were later replaced by fins on the stern of the envelope. This ship was purchased by the naval authorities, and after purchase was more or less reconstructed, but carried out little flying. At the outbreak of war she was lying deflated in the shed at Farnborough. As will be seen later, this was the envelope which was rigged to the original experimental S.S. airship in the early days of 1915, and is for this reason, if for no other, particularly interesting. WILLOWS No. 5 This ship was of similar design, but of greater capacity. The envelope, which was composed of rubber-proofed fabric, gave a volume of 50,000 cubic feet, and contained two ballonets. A 60 horsepower engine drove two swivelling propellers at an estimated speed of 38 miles per hour. She was constructed at Hendon, from where she made several short trips. MARSHALL FOX'S AIRSHIP In the early days of the war an airship was constructed by Mr. Marshall Fox which is worthy of mention, although it never flew. It was claimed that this ship was a rigid airship, although from its construction it could only be looked upon as a non-rigid ship, having a wooden net-work around its envelope. The hull was composed of wooden transverse frames forming a polygon of sixteen sides, with radial wiring fitted to each transverse frame. The longitudinal members were spiral in form and were built up of three-ply lathes. A keel of similar construction ran along the under side of the hull which carried the control position and compartments for two Green engines, one of 40 horse-power, the other of 80 horse-power, together with the petrol, bombs, etc. In the hull were fitted fourteen gasbags giving a total capacity of 100,000 cubic feet. The propeller drive was obtained by means of a wire rope. The gross lift of the ship was 4,276 lb., and the weight of the structure, complete with engines, exceeded this. It became apparent that the ship could never fly, and work was suspended. She was afterwards used for carrying out certain experiments and at a later date was broken up. Apart from the various airships built under contract for the Government there do not appear to be any other ships built by private firms which were completed and actually flew. It is impossible to view this lack of enterprise with any other feelings than those of regret, and it was entirely due to this want of foresight that Great Britain entered upon the World War worse equipped, as regards airships, than the Central Empires or any of the greater Allied Powers. CHAPTER IV BRITISH ARMY AIRSHIPS The French and German military authorities began to consider airships as an arm of the Service in the closing years of the nineteenth century, and devoted both time and considerable sums of money in the attempt to bring them to perfection. Their appearance in the British Army was delayed for many years on account of the expense that would be incurred in carrying out experiments. In 1902, Colonel Templer, at that time head of the Balloon Section, obtained the necessary sanction to commence experiments, and two envelopes of gold-beaters skin of 50,000 cubic feet capacity were built. With their completion the funds were exhausted, and nothing further done until 1907. NULLI SECUNDUS I In 1907 the first complete military airship in England was built, which bore the grandiloquent title of Nulli Secundus. One of the envelopes constructed by Colonel Templer was used: it was cylindrical in shape with spherical ends. Suspended beneath the envelope by means of a net and four broad silk bands was a triangular steel framework or keel from which was slung a small car. A 50 horsepower Antoinette engine was situated in the forward part of the car which drove two metal-bladed propellers by belts. At the after part of the keel were fitted a rudder and small elevators, and two pairs of movable horizontal planes were also fitted forward. It is remarkable that no stabilizing surfaces whatsoever were mounted. The envelope was so exceedingly strong that a high pressure of gas could be sustained, and ballonets were considered unnecessary, but relief valves were employed. The first flight took place in September and was fairly successful. Several were made afterwards, and in October she was flown over London and landed at the Crystal Palace. The flight lasted 3 hours and 25 minutes, which constituted at the time a world's record. Three days later, owing to heavy winds, the ship had to be deflated and was taken back to Farnborough. NULLI SECUNDUS II In 1908 the old ship was rebuilt with several modifications. The envelope was increased in length and was united to the keel by means of a covering of silk fabric in place of the net, four suspension bands being again used. A large bow elevator was mounted which made the ship rather unstable. A few flights were accomplished, but the ship proved of little value and was broken up. BABY This little airship made its first appearance in the spring of 1909. The envelope was fish-shaped and composed of gold-beater's skin, with a volume of 21,000 cubic feet. One ballonet was contained in the envelope which, at first, had three inflated fins to act as stabilizers. These proved unsatisfactory as they lacked rigidity, and were replaced after the first inflation by the ordinary type. Two 8 horse-power 3-cylinder Berliet engines were mounted in a long car driving a simple propeller, and at a later date were substituted by a R.E.P. engine which proved most unsatisfactory. During the autumn permission was obtained to enlarge the envelope and fit a more powerful engine. BETA Beta was completed in May, 1910. The envelope was that of the Baby enlarged, and now had a volume of 35,000 cubic feet. The car was composed of a long frame, having a centre compartment for the crew and engines, which was the standard practice at that time for ships designed by the Astra Company. A 35 horse-power Green engine drove two wooden two-bladed propellers by chains. The ship was fitted with an unbalanced rudder, while the elevators were in the front of the frame. This ship was successful, and in June flew to London and back, and in September took part in the Army manoeuvres, on one occasion being in the air for 7 3/4 hours without landing, carrying a crew of three. Trouble was experienced in the steering, the elevators being situated too near the centre of the ship to be really efficient and were altogether too small. In 1912, Beta, having been employed regularly during the previous year, was provided with a new car having a Clerget engine of 45 horse-power. In 1913 she was inflated for over three months and made innumerable flights, on one occasion carrying H.R.H. the Prince of Wales as passenger. She had at that time a maximum speed of 35 miles per hour, and could carry fuel for about eight hours with a crew of three. GAMMA In 1910 the Gamma was also completed. This was a much bigger ship with an envelope of 75,000 cubic feet capacity, which, though designed in England, had been built by the Astra Company in Paris. The car, as in Beta, was carried in a long framework suspended from the envelope. This portion of the ship was manufactured in England, together with the machinery. This consisted of an 80 horse-power Green engine driving swivelling propellers, the gears and shafts of which were made by Rolls Royce. The engine drove the propeller shafts direct, one from each end of the crankshaft. Originally the envelope was fitted with inflated streamline stabilizers on either side, but at a later date these were replaced by fixed stabilizing planes. At the same time the Green engine was removed and two Iris engines of 45 horse-power were installed, each driving a single propeller. There were two pairs of elevators, each situated in the framework, one forward, the other aft. In 1912, having been rigged to a new envelope of 101,000 cubic feet capacity, the ship took part in the autumn manoeuvres, and considerable use was made of wireless telegraphy. In a height reconnaissance the pilot lost his way, and running out of petrol drifted all night, but was safely landed. When returning to Farnborough the rudder controls were broken and the ship was ripped. In this operation the framework was considerably damaged. When repairs were being carried out the elevators were removed from the car framework and attached to the stabilizing fins in accordance with the method in use to-day. CLEMENT-BAYARD In 1910 it was arranged by a committee of Members of Parliament that the Clement-Bayard firm should send over to England a large airship on approval, with a view to its ultimate purchase by the War Office, and a shed was erected at Wormwood Scrubs for its accommodation. This ship arrived safely in October, but was very slow and difficult to control. The envelope, moreover, was of exceedingly poor quality and consumed so much gas that it was decided to deflate it. She was taken to pieces and never rebuilt. LEBAUDY About the same time, interest having been aroused in this country by the success of airships on the Continent, the readers of the Morning Post subscribed a large sum to purchase an airship for presentation to the Government. This was a large ship of 350,000 cubic feet capacity and was of semi-rigid design, a long framework being suspended from the envelope which supported the weight of the car. It had two engines of 150 horse-power which developed a speed of about 32 miles per hour. The War Office built a shed at Farnborough to house it, and in accordance with dimensions given by the firm a clearance of 10 feet was allowed between the top of the ship and the roof of the shed. Inconceivable as it may sound, the overall height of the ship was increased by practically 10 feet without the War Office being informed. The ship flew over and was landed safely, but on being taken into the shed the envelope caught on the roof girders, owing to lack of headroom, and was ripped from end to end. The Government agreed to increase the height of the shed and the firm to rebuild the ship. This was completed in March, 1911, and the ship was inflated again. On carrying out a trial flight, having made several circuits at 600 feet, she attempted to land, but collided with a house and was completely wrecked. This was the end of a most unfortunate ship, and her loss was not regretted. DELTA Towards the end Of 1910 the design was commenced of the ship to be known as the Delta, and in 1911 the work was put in hand. The first envelope was made of waterproofed silk. This proved a failure, as whenever the envelope was put up to pressure it invariably burst. Experiments were continued, but no good resulting, the idea was abandoned and a rubber-proofed fabric envelope was constructed of 173,000 cubic feet volume. This ship was inflated in 1912. The first idea was to make the ship a semi-rigid by lacing two flat girders to the sides of the envelope to take the weight of the car. This idea had to be abandoned, as in practice, when the weight of the car was applied, the girders buckled. The ship was then rigged as a non-rigid. A novelty was introduced by attaching a rudder flap to the top stabilizing fin, but as it worked somewhat stiffly it was later on removed. This ship took part in the manoeuvres of 1912 and carried out several flights. She proved to be exceedingly fast, being capable of a speed of 44 miles per hour. In 1913 she was completely re-rigged and exhibited at the Aero Show, but the re-designed rigging revealed various faults and it was not until late in the year that she carried out her flight trials. Two rather interesting experiments were made during these flights. In one a parachute descent was successfully accomplished; and in another the equivalent weight of a man was picked up from the ground without assistance or landing the ship. ETA The Eta was somewhat smaller than the Delta, containing only 118,000 cubic feet of hydrogen, and was first inflated in 1913. The envelope was composed of rubber-proofed fabric and a long tapering car was suspended, this being in the nature of a compromise between the short car of the, Delta and the long framework gear of the Gamma. Her engines were two 80 horse-power Canton-Unne, each driving one propeller by a chain. This ship proved to be a good design and completed an eight-hour trial flight in September. On her fourth trial she succeeded in towing the disabled naval airship No. 2 a distance of fifteen miles. Her speed was 42 miles per hour, and she could carry a crew of five with fuel for ten hours. On January 1st, 1914, the Army disbanded their Airship Section, and the airships Beta, Gamma, Delta and Eta were handed over to the Navy together with a number of officers and men. CHAPTER V EARLY DAYS OF THE NAVAL AIRSHIP SECTION--PARSEVAL AIRSHIPS, ASTRA-TORRES TYPE, ETC. The rapid development of the rigid airships in Germany began to create a considerable amount of interest in official circles. It was realized that those large airships in the future would be invaluable to a fleet for scouting purposes. It was manifest that our fleet, in the event of war, would be gravely handicapped by the absence of such aerial scouts, and that Germany would hold an enormous advantage if her fleet went to sea preceded by a squadron of Zeppelin airships. The Imperial Committee, therefore, decided that the development of the rigid airship should be allotted to the Navy, and a design for Rigid Airship No. 1 was prepared by Messrs. Vickers in conjunction with certain naval officers in the early part of 1909. As will be seen later this ship was completed in 1911, but broke in two in September of that year and nothing more was done with her. In February, 1912, the construction of rigid airships was discontinued, and in March the Naval Airship section was disbanded. In September, 1912, the Naval Airship section was once more reconstituted and was stationed at Farnborough. The first requirements were airships, and owing to the fact that airship construction was so behindhand in this country, in comparison with the Continent, it was determined that purchases should be made abroad until sufficient experience had been gained by British firms to enable them to compete with any chance of success against foreign rivals. First a small non-rigid, built by Messrs. Willows, was bought by the Navy to be used for the training of airship pilots. In addition an Astra-Torres airship was ordered from France. This was a ship of 229,450 cubic feet capacity and was driven by twin Chenu engines of 210 horse-power each. She carried a crew of six, and was equipped with wireless and machine guns. The car could be moved fore and aft for trimming purposes, either by power or by hand. This was, however, not satisfactory, and was abandoned. In April 1918, Messrs. Vickers were asked to forward proposals for a rigid airship which afterwards became e known as No. 9. Full details of the vicissitudes connected with this ship will be given in the chapter devoted to Rigid Airships. In July, approval was granted for the construction of six non-rigid ships. Three of these were to be of the German design of Major von Parseval and three of the Forlanini type, which was a semi-rigid design manufactured in Italy. The order for the Parsevals was placed with Messrs. Vickers and for the Forlaninis with Messrs. Armstrong. The Parseval airship was delivered to this country and became known as No. 4; a second ship of the same type was also building when war broke out; needless to say this ship was never delivered. At a later date Messrs. Vickers, who had obtained the patent rights of the Parseval envelope, completed the other two ships of the order. The Forlanini ship was completing in Italy on the declaration of war and was taken over by the Italians; Messrs. Armstrong had not commenced work on the other two. These ships, although allocated numbers, never actually came into being. PARSEVAL AIRSHIP No. 4 This airship deserves special consideration for two reasons; firstly, on account of the active-service flying carried out by it during the first three years of the war, and, secondly, for its great value in training of the officers and men who later on became the captains and crews of rigid airships. The Parseval envelope is of streamline shape which tapers to a point at the tail, and in this ship was of 300,000 cubic feet capacity. The system of rigging being patented, can only be described in very general terms. The suspensions carrying the car are attached to a large elliptical rigging band which is formed under the central portion of the envelope. To this rigging band are attached the trajectory bands which pass up the sides and over the top of the envelope, sloping away from the centre at the bottom towards the nose and tail at the top. The object of this is to distribute the load fore and aft over the envelope. These bands, particularly at the after end of the ship, follow a curved path, so that they become more nearly vertical as they approach the upper surface of the envelope. This has the effect of bringing the vertical load on the top of the envelope; but a greater portion of the compressive force comes on the lower half, where it helps to resist the bending moment due to the unusually short suspensions. A single rudder plane and the ordinary elevator planes were fitted to the envelope. A roomy open car was provided for this ship, composed of a duralumin framework and covered with duralumin sheeting. Two 170 horse-power Maybach engines were mounted at the after end of the car, which drove two metal-bladed reversible propellers. These propellers were later replaced by standard four-bladed wooden ones and a notable increase of speed was obtained. Two officers and a crew of seven men were carried, together with a wireless installation and armament. This airship, together with No. 3, took part in the great naval review at Spithead, shortly before the commencement of the war, and in addition to the duties performed by her in the autumn of 1914, which are mentioned later, carried out long hours of patrol duty from an east coast station in the summer of 1917. In all respects she must be accounted a most valuable purchase. PARSEVAL AIRSHIPS 5, 6 and 7 Parseval No. 5 was not delivered by Germany owing to the war, so three envelopes and two cars were built by Messrs. Vickers on the design of the original ship. These were delivered somewhat late in the war, and on account of the production of the North Sea airship with its greater speed were not persevered with. The dimensions of the envelopes were somewhat increased, giving a cubic capacity of 325,000 cubic feet. Twin Maybach engines driving swivelling propellers were installed in the car, which was completely covered in, but these ships were slow in comparison with later designs, and were only used for the instruction of officers and men destined for the crews of rigid airships then building. An experimental ship was made in 1917 which was known as Parseval 5; a car of a modified coastal pattern with two 240 horse-power Renault engines was rigged to one of envelopes. During a speed trial, this ship was calculated to have a ground speed of 50 to 53 miles per hour. The envelope, however, consumed an enormous amount gas and for this reason the ship was deflated and struck off the list of active ships. This digression on Parseval airships has anticipated events somewhat, and a return must now be made to earlier days. Two more Astra-Torres were ordered from France, one known as No. 8, being a large ship of 4,00,000 cubic feet capacity. She was fitted with two Chenu engines of 240 horse-power, driving swivelling propellers. This ship was delivered towards the end of the year 1914. The second Astra was of smaller capacity and was delivered, but as will be seen later, was never rigged, the envelope being used for the original coastal ship and the car slung to the envelope of the ex-army airship Eta. On January 1st, 1914, an important event took place: the Army disbanded their airship service, and the military ships together with certain officers and men were transferred to the Naval Air Service. Before proceeding further, it may be helpful to explain the system by which the naval airships have been given numbers. These craft are always known by the numbers which they bear, and the public is completely mystified as to their significance whenever they fly over London or any large town. It must be admitted that the method is extremely confusing, but the table which follows should help to elucidate the matter. The original intention was to designate each airship owned by the Navy by a successive number. The original airship, the rigid Mayfly, was known as No. 1, the Willows airship No. 2, and so on. These numbers were allocated regardless of type and as each airship was ordered, consequently some of these ships, for example the Forlaninis, never existed. That did not matter, however, and these numbers were not utilized for ships which actually were commissioned. On the transfer of the army airships, four of these, the Beta, Gamma, Delta and Eta, were given their numbers as they were taken over, together with two ships of the Epsilon class which were ordered from Messrs. Rolls Royce, but never completed. In this way it will be seen that numbers 1 to 22 are accounted for. In 1915 it was decided to build a large number of small ships for anti-submarine patrol, which were called S.S.'s or Submarine Scouts. It was felt that it would only make confusion worse confounded if these ships bore the original system of successive numbering and were mixed up with those of later classes which it was known would be produced as soon as the designs were completed. Each of these ships was accordingly numbered in its own class, S.S., S.S.P., S.S. Zero, Coastal, C Star and North Sea, from 1 onwards as they were completed. In the case of the rigids, however, for some occult reason the old system of numbering was persisted in. The letter R is prefixed before the number to show that the ship is a rigid. Hence we have No. 1 a rigid, the second rigid constructed is No. 9, or R 9, and the third becomes R 23. From this number onwards all are rigids and are numbered in sequence as they are ordered, with the exception of the last on the list, which is a ship in a class of itself. This ship the authorities, in their wisdom, have called R 80--why, nobody knows. With this somewhat lengthy and tedious explanation the following table may be understood: No. Type. Remarks. 1. Rigid Wrecked, Sept. 24, 1911. 2. Willows Became S.S. 1. 3. Astra-Torres Deleted, May 1916. 4. Parseval Deleted, July, 1917. 5. Parseval Never delivered from Germany. (Substitute ship built by Messrs. Vickers). 6. Parseval Built by Messrs. Vickers. 7. Parseval Built by Messrs. Vickers. 8. Astra-Torres Deleted, May, 1916. 9. Rigid Deleted, June, 1918. 10. Astra-Torres Envelope used for C 1. 11. Forlanini Never delivered owing to war. 12. Forlanini Never delivered owing to war. 13. Forlanini Never delivered owing to war. 14. Rigid Never built. 15. Rigid Never built. 16. Astra-Torres See No. 8. 17. Beta Transferred from Army. Deleted, May, 1916. 18. Gamma Deleted, May, 1916. 19. Delta Deleted, May, 1916. 20. Eta Transferred from the Army. Fitted with car from No. 10. Deleted May, 1916. 21. Epsilon Construction cancelled May, 1916. 22. Epsilon Construction cancelled May, 1916. 23. Rigid 23 Class. 24. Rigid 23 Class. 25. Rigid 23 Class. 26. Rigid 23 Class. 27. Rigid 23x Class. 28. Rigid 23x Class. Never completed. 29. Rigid 23x Class. 30. Rigid 23x Class. Never completed. 31. Rigid 31 Class. 32. Rigid 31 Class, building. 33. Rigid 33 Class. 34. Rigid 33 Class. 35. Rigid Cancelled. 36. Rigid Building. 37. Rigid Building. 38. Rigid Building. 39. Rigid Building. 40. Rigid Building. 80. Rigid Building. In August, 1914, Europe, which had been in a state of diplomatic tension for several years, was plunged into the world war. The naval airship service at the time was in possession of two stations, Farnborough and Kingsnorth, the latter in a half-finished condition. Seven airships were possessed, Nos. 2, 3 and 4, and the four ex-army ships--Beta, Gamma, Delta and Eta--and of these only three, Nos. 3, 4 and the Beta, were in any condition for flying. Notwithstanding this, the utmost use was made of the ships which were available. On the very first night of the war, Nos. 3 and 4 carried out a reconnaissance flight over the southern portion of the North Sea, and No. 4 came under the fire of territorial detachments at the mouth of the Thames on her return to her station. These zealous soldiers imagined that she was a German ship bent on observation of the dockyard at Chatham. No. 3 and No. 4 rendered most noteworthy service in escorting the original Expeditionary Force across the Channel, and in addition to this No. 4 carried out long patrols over the channel throughout the following winter. No. 17 (Beta) also saw active service, as she was based for a short period early in 1915 at Dunkirk, and was employed in spotting duties with the Belgian artillery near Ostend. The Gamma and the Delta were both lying deflated at Farnborough at the outbreak of the war, and in the case of the latter the car was found to be beyond repair, and she was accordingly deleted. The Gamma was inflated in January, 1915, and was used for mooring experiments. The Eta, having been inflated and deflated several times owing to the poor quality of the envelope, attempted to fly to Dunkirk in November, 1914. She encountered a snowstorm near Redhill and was compelled to make a forced landing. In doing this she was so badly damaged as to be incapable of repair, and at a later date was deleted. No. 8, which was delivered towards the end of 1914, was also moored out in the open for a short time near Dunkirk, and carried out patrol in the war zone of the Belgian coast. So ends the story of the Naval Airship Service before the war. With the submarine campaign ruthlessly waged by the Germans from the spring of 1915 and onwards, came the airship's opportunity, and the authorities grasped the fact that, with development, here was the weapon to defeat the most dangerous enemy of the Empire. The method of development and the success attending it the following chapters will show. CHAPTER VI NAVAL AIRSHIPS.--THE NON-RIGIDS--S.S. TYPE The development of the British airships of to-day may be said to date from February 28th, 1915. On that day approval was given for the construction of the original S.S. airship. At this time the Germans had embarked upon their submarine campaign, realizing, with the failure of their great assaults on the British troops in Flanders, that their main hope of victory lay in starving Great Britain into surrender. There is no doubt that the wholesale sinking of our merchant shipping was sufficient to cause grave alarm, and the authorities were much concerned to devise means of minimizing, even if they could not completely eliminate the danger. One proposal which was adopted, and which chiefly concerns the interests of this book, was the establishment of airship stations round the coasts of Great Britain. These stations were to be equipped with airships capable of patrolling the main shipping routes, whose functions were to search for submarines and mines and to escort shipping through the danger zones in conjunction with surface craft. Airship construction in this country at the time was, practically speaking, non-existent. There was no time to be wasted in carrying out long and expensive experiments, for the demand for airships which could fulfil these requirements was terribly urgent, and speed of construction was of primary importance. The non-rigid design having been selected for simplicity in construction, the expedient was tried of slinging the fuselage of an ordinary B.E. 2C aeroplane, minus the wings, rudder and elevators and one or two other minor fittings, beneath an envelope with tangential suspensions, as considerable experience had been gained already in a design of this type. For this purpose the envelope of airship No. 2, which was lying deflated in the shed at Farnborough, was rushed post haste to Kingsnorth, inflated and rigged to the fuselage prepared for it. The work was completed with such despatch that the airship carried out her trial flight in less than a fortnight from approval being granted to the scheme. The trials were in every way most satisfactory, and a large number of ships of this design was ordered immediately. At the same time two private firms were invited to submit designs of their own to fulfil the Admiralty requirements. One firm's design, S.S. 2, did not fulfil the conditions laid down and was put out of commission; the other, designed by Messrs. Armstrong, was sufficiently successful for them to receive further orders. In addition to these a car was designed by Messrs. Airships Ltd., which somewhat resembled a Maurice Farman aeroplane body, and as it appeared to be suitable for the purpose, a certain number of these was also ordered. About this period the station at Farnborough was abandoned by the Naval Airship Service to make room for the expansion of the military aeroplane squadrons. The personnel and airships were transferred to Kingsnorth, which became the airship headquarters. The greatest energy was displayed in preparing the new stations, which were selected as bases for the airships building for this anti-submarine patrol. Small sheds, composed of wood, were erected with almost incredible rapidity, additional personnel was recruited, stores were collected, huts built for their accommodation and that of the men, and by the end of the summer the organization was so complete that operations were enabled to commence. The S.S., or submarine scout, airship proved itself a great success. Beginning originally with a small programme the type passed through various developments until, at the conclusion of the war, no fewer than 150 ships of various kinds had been constructed. The alterations which took place and the improvements effected thereby will be considered at some length in the following pages. S.S.B.E. 2C The envelope of the experimental ship S.S. 1 was only of 20,500 cubic feet capacity; for the active-service ships, envelopes of similar shape of 60,000 cubic feet capacity were built. The shape was streamline, that is to say, somewhat blunt at the nose and tapering towards the tail, the total length being 143 feet 6 inches, with a maximum diameter of 27 feet 9 inches. The gross lift of these ships with 98% pure gas at a temperature of 60 degrees Fahrenheit and barometer 30 inches, is 4,180 lb. The net lift available for crew, fuel, ballast, armament, etc., 1,434 lb., and the disposable lift still remaining with crew of two on board and full tanks, 659 lb. The theoretical endurance at full speed as regards petrol consumption is a little over 8 hours, but in practice it is probable that the oil would run short before this time had been reached. At cruising speed, running the engine at 1,250 revolutions, the consumption is at the rate of 3.6 gallons per hour, which corresponds to an endurance of 16 1/2 hours. With the engine running at 1,800 revolutions, a speed of 50.6 miles per hour has been reached by one of these ships, but actually very few attained a greater speed than 40 miles per hour. The envelopes of S.S. airships are composed of rubber-proofed fabric, two fabrics being used with rubber interposed between and also on the inner or gas surface. To render them completely gastight and as impervious to the action of the weather, sun, etc., as possible, five coats of dope are applied externally, two coats of Delta dope, two of aluminium dope and one of aluminium varnish applied in that order. One ripping panel is fitted, which is situated on the top of the envelope towards the nose. It has a length of 14 feet 5 inches and a breadth of about 8 inches. The actual fabric which has to be torn away overlaps the edge of the opening on each side. This overlap is sewn and taped on to the envelope and forms a seam as strong and gastight as any other portion of the envelope. Stuck on this fabric is a length of biased fabric 8 1/4 inches wide. These two strips overlap the opening at the forward end by about three feet. At this end the two strips are loose and have a toggle inserted at the end to which the ripping cord is tied. The ripping cord is operated from the car. It is led aft from the ripping panel to a pulley fixed centrally over the centre of the car, from the pulley the cord passes round the side of the envelope and through a gland immediately below the pulley. The nose of the envelope is stiffened to prevent it blowing in. For this purpose 24 canes are fitted in fabric pockets around the nose and meet at a point 2 1/4 inches in front of the nose. An aluminium conical cap is fitted over the canes and a fabric nose cap over the whole. Two ballonets are provided, one forward and one aft, the capacity of each being 6,375 cubic feet. The supply of air for filling these is taken from the propeller draught by a slanting aluminium tube to the underside of the envelope, where it meets a longitudinal fabric hose which connects the two ballonet air inlets. Non-return fabric valves known as crab-pots are fitted in this fabric hose on either side of their junction with the air scoop. Two automatic air valves are fitted to the underside of the envelope, one for each ballonet. The air pressure tends to open the valve instead of keeping it shut and to counteract this the spring of the valve is inside the envelope. The springs are set to open at a pressure of 25 to 28 mm. Two gas valves are also fitted, one on the top of the envelope, the other at the bottom. The bottom gas valve spring is set to open at 30 to 35 mm. pressure, the top valve is hand controlled only. These valves are all very similar in design. They consist of two wooden rings, between which the envelope is gripped, and which are secured to each other by studs and butterfly nuts. The valve disc, or moving portion of the valve, is made of aluminium and takes a seating on a thin india rubber ring stretched between a metal rod bent into a circle of smaller diameter than the valve opening and the wooden ring of the valve. When it passes over the wooden ring it is in contact with the envelope fabric and makes the junction gastight. The disc is held against the rubber by a compressed spring. The valve cords are led to the pilot's seat through eyes attached to the envelope. The system of rigging or car suspension is simplicity itself and is tangential to the envelope. On either side there are six main suspensions of 25 cwt. stranded steel cable known as "C" suspensions. Each "C" cable branches into two halves known as the "B" bridles, which in turn are supported at each end by the bridles known as "A." The ends of the "A" bridles are attached to the envelope by means of Eta patches. These consist of a metal D-shaped fitting round which the rigging is spliced and through which a number of webbing bands are passed which are spread out fanwise and solutioned to the envelope. It will thus be seen that the total load on each main suspension is proportionally taken up by each of the four "A" bridles, and that the whole weight of the car is equally distributed over the greater part of the length of the envelope. Four handling guys for manoeuvering the ship on the ground are provided under the bow and under the stem. A group of four Eta patches are placed close together, which form the point of attachment for two guys in each case. The forward of these groups of Eta patches forms the anchoring point. The bridle, consisting of 25 cwt. steel cable, is attached here and connected to the forepart of the skids of the car. The junction of this bridle with the two cables from the skids forms the mooring point and there the main trail rope is attached. This is 120 feet long and composed of 2-inch manilla. This is attached, properly coiled, to the side of the car and is dropped by a release gear. It is so designed that when the airship is held in a wind by the trail rope the strain is evenly divided between the envelope and the car. The grapnel carried is fitted to a short length of rope. The other end of the rope has an eye, and is fitted to slide down the main trail rope and catch on a knot at the end. For steering and stabilizing purposes the S.S. airship was originally designed with four fins and rudders, which were to be set exactly radial to the envelope. In some cases the two lower fins and rudders were abandoned, and a single vertical fin and rudder fitted centrally under the envelope were substituted. The three planes are identical in size and measure 16 feet by 8 feet 6 inches, having a gross stabilizing area of 402 1/2 square feet. They are composed of spruce and aluminium and steel tubing braced with wire and covered by linen doped and varnished when in position. The original rudders measured 3 feet by 8 feet 6 inches. In the case, however, of the single plane being fitted, 4-feet rudders are invariably employed. Two kingposts of steel tube are fitted to each plane and braced with wire to stiffen the whole structure. The planes are attached to the envelope by means of skids and stay wires. The skids, composed of spruce, are fastened to the envelope by eight lacing patches. The car, it will be remembered, is a B.E. 2C fuselage stripped of its wings, rudders and elevators, with certain other fittings added to render it suitable for airship work. The undercarriage is formed of two ash skids, each supported by three struts. The aeroplane landing wheels, axle and suspensions are abandoned. In the forward end of the fuselage was installed a 75 horse-power air cooled Renault engine driving a single four-bladed tractor propeller through a reduction gear of 2 to 1. The engine is of the 8-cylinder V type, weighing 438 lb. with a bore of 96 mm. and a stroke of 120 mm. The Claudel-Hobson type of carburettor is employed with this engine. The type of magneto used is the Bosch D.V.4, there being one magneto for each line of cylinders. In the older French Renaults the Bosch H.L.8 is used, one magneto supplying the current to all the plugs. Petrol is carried in three tanks, a gravity and intermediate tank as fitted to the original aeroplane, and a bottom tank placed underneath the front seat of the car. The petrol is forced by air pressure from the two lower tanks into the gravity tank and is obtained by a hand pump fitted outside the car alongside the pilot's seat. The oil tank is fitted inside the car in front of the observer. The observer's seat is fitted abaft the engine and the pilot's seat is aft of the observer. The observer, who is also the wireless operator, has the wireless apparatus fitted about his seat. This consists of a receiver and transmitter fitted inside the car, which derives power from accumulator batteries. The aerial reel is fitted outside the car. During patrols signals can be sent and received up to and between 50 and 60 miles. The pilot is responsible for the steering and the running of the engine, and the controls utilized are the fittings supplied with the aeroplane. Steering is operated by the feet and elevating by a vertical wheel mounted in a fore and aft direction across the seat. The control wires are led aft inside the fairing of the fuselage to the extreme end, whence they pass to the elevators and rudders. The instrument board is mounted in front of the pilot. The instruments comprise a watch, an air-speed indicator graduated in knots, an aneroid reading to 10,000 feet, an Elliott revolution counter, a Clift inclinometer reading up to 20 degrees depression or elevation, a map case with celluloid front. There are in addition an oil pressure gauge, a petrol pressure gauge, a glass petrol level and two concentric glass pressure gauges for gas pressure. The steering compass is mounted on a small wooden pedestal on the floor between the pilot's legs. The water-ballast tank is situated immediately behind the pilot's seat and contains 14 gallons of water weighing 140 lbs. The armament consists of a Lewis gun and bombs. The bombs are carried in frames suspended about the centre of the undercarriage. The bomb sight is fitted near the bomb releasing gear outside the car on the starboard side adjacent to the pilot's seat. The Lewis gun, although not always carried on the early S.S. airships, was mounted on a post alongside the pilot's seat. S.S. MAURICE FARMAN For this type of S.S. the cars were built by Messrs. Airships Ltd. In general appearance they resemble the Maurice Farman aeroplane and were of the pusher type; 60,000 and in later cases 70,000 cubic feet envelopes were rigged to these ships, which proved to be slightly slower than the B.E. 2C type, but this was compensated for owing to the increased comfort provided for the crew, the cars being more roomy and suitable for airship work in every way. The system of rigging to all intents and purposes is the same in all types of S.S. ships, the suspensions being adjusted to suit the different makes of car. In these ships the pilot sits in front, and behind him is the wireless telegraphy operator; in several cases a third seat was fitted to accommodate a passenger or engineer; dual rudder and elevator controls are provided for the pilot and observer. The engine is mounted aft, driving a four-bladed pusher propeller, with the petrol tanks situated in front feeding the carburettors by gravity. The engines used are Rolls Royce Renaults, although in one instance a 75 horse-power Rolls Royce Hawk engine was fitted, which assisted in making an exceedingly useful ship. S.S. ARMSTRONG WHITWORTH The car designed by Messrs. Armstrong Whitworth is of the tractor type and is in all ways generally similar to the B.E. 2C. The single-skid landing chassis with buffers is the outstanding difference. These cars had to be rigged to 70,000 cubic feet envelopes otherwise the margin of lift was decidedly small. A water-cooled 100 horse-power Green engine propelled the ship, and a new feature was the disposition of petrol, which was carried in two aluminium tanks slung from the envelope and fed through flexible pipes to a two-way cock and thence to the carburettors. These tanks, which were supported in a fabric sling, showed a saving in weight of 100 lb. compared with those fitted in the B.E. 2C. For over two years these three types of S.S. ships performed a great part of our airship patrol and gave most excellent results. Owing to the constant patrol which was maintained whenever weather conditions were suitable, the hostile submarine hardly dared to show her periscope in the waters which were under observation. In addition to this, practically the whole of the airship personnel now filling the higher positions, such as Captains of Rigids and North Seas, graduated as pilots in this type of airship. From these they passed to the Coastal and onwards to the larger vessels. As far as is known the height record for a British airship is still held by an S.S.B.E. 2C, one of these ships reaching the altitude of 10,300 feet in the summer of 1916. The Maurice Farman previously mentioned as being fitted with the Hawk engine, carried out a patrol one day of 18 hours 20 minutes. In the summer of 1916 one of the Armstrong ships was rigged to an envelope doped black and sent over to France. While there she carried out certain operations at night which were attended with success, proving that under certain circumstances the airship can be of value in operating with the military forces over land. S.S.P. In 1916 the design was commenced for an S.S. ship which should have a more comfortable car and be not merely an adaptation of an aeroplane body. These cars, which were of rectangular shape with a blunt nose, were fitted with a single landing skid aft, and contained seats for three persons. The engine, a 100 horse-power water-cooled Green, was mounted on bearers aft and drove a four-bladed pusher propeller. The petrol was carried in aluminium tanks attached by fabric slings to the axis of the envelope. Six of these ships were completed in the spring of 1917 and were quite satisfactory, but owing to the success achieved by the experimental S.S. Zero it was decided to make this the standard type of S.S. ship, and with the completion of the sixth the programme of the S.S.P's was brought to a close. These ships enjoyed more than, perhaps, was a fair share of misfortune, one was wrecked on proceeding to its patrol station and was found to be beyond repair, and another was lost in a snowstorm in the far north. The remainder, fitted at a later date with 75 horse-power Rolls Royce engines, proved to be a most valuable asset to our fleet of small airships. S.S. ZERO The original S.S. Zero was built at a south-coast station by Air Service labour, and to the design of three officers stationed there. The design of the car shows a radical departure from anything that had been previously attempted, and as a model an ordinary boat was taken. In shape it is as nearly streamline as is practicable, having a keel and ribs of wood with curved longitudinal members, the strut ends being housed in steel sockets. The whole frame is braced with piano wire set diagonally between the struts. The car is floored from end to end, and the sides are enclosed with 8-ply wood covered with fabric. Accommodation is provided for a wireless telegraphy operator, who is also a gunner, his compartment being situated forward, amidships is the pilot and abaft this seat is a compartment for the engineer. The engine selected was the 75 horse-power water-cooled Rolls Royce, it being considered to be the most efficient for the purpose. The engine is mounted upon bearers above the level of the top of the car, and drives a four-bladed pusher propeller. The car is suspended from an envelope of 70,000 cubic feet capacity, and the system of rigging is similar to that in use on all S.S. ships. The petrol is carried in aluminium tanks slung on the axis of the envelope, identically with the system in use on the S.S.P's. The usual elevator planes are adopted with a single long rudder plane. The speed of the Zero is about 45 miles per hour and the ship has a theoretical endurance of seventeen hours; but this has been largely exceeded in practice. The original ship proved an immediate success, and a large number was shortly afterwards ordered. As time went on the stations expanded and sub-stations were added, while the Zero airship was turned out as fast as it could be built, until upwards of seventy had been commissioned. The work these ships were capable of exceeded the most sanguine expectations. Owing to their greater stability in flight and longer hours of endurance, they flew in weather never previously attempted by the earlier ships. With experience gained it was shown that a large fleet of airships of comparatively small capacity is of far more value for an anti-submarine campaign than a lesser fleet of ships of infinitely greater capacity. The average length of patrol was eight hours, but some wonderful duration flights were accomplished in the summer of 1918, as the following figures will show. The record is held by S.S.Z. 39, with 50 hours 55 minutes; another is 30 hours 20 minutes; while three more vary from 25 1/2 hours to 26 1/4. Although small, the Zero airship has been one of the successes of the war, and we can claim proudly that she is entirely a British product. S.S. TWIN During the year 1917, designs were submitted for a twin-engined S.S. airship, the idea being to render the small type of airship less liable to loss from engine failure. The first design proved to be a failure, but the second was considered more promising, and several were built. Its capacity is 100,000 cubic feet, with a length of 164 feet 6 inches, and the greatest diameter 32 feet. The car is built to carry five, with the engines disposed on gantries on the port and starboard side, driving pusher propellers. This type, although in the experimental stage, is being persevered with, and the intention is that it will gradually supplant the other S.S. classes. It is calculated that it will equal if not surpass the C Star ship in endurance, besides being easier to handle and certainly cheaper to build. "COASTAL" AND "C STAR" AIRSHIPS The urgent need for a non-rigid airship to carry out anti-submarine patrol having been satisfied for the time with the production of the S.S. B.E. 2C type, the airship designers of the Royal Naval Air Service turned their attention to the production of an airship which would have greater lift and speed than the S.S. type, and, consequently, an augmented radius of action, together with a higher degree of reliability. As the name "Coastal" or "Coast Patrol" implies, this ship was intended to carry out extended sea patrols. To obtain these main requirements the capacity of the envelope for this type was fixed at 170,000 cubic feet, as compared with the 60,000 cubic feet and, later, the 70,000 cubic feet envelopes adopted for the S.S. ships. Greater speed was aimed at by fitting two engines of 150 horse-power each, and it was hoped that the chances of loss owing to engine failure would be considerably minimized. The Astra-Torres type of envelope, with its system of internal rigging, was selected for this class of airship; in the original ship the envelope used was that manufactured by the French Astra-Torres Company, and to which it had been intended to rig a small enclosed car. The ship in question was to be known as No. 10. This plan was, however, departed from, and the car was subsequently rigged to the envelope of the Eta, and a special car was designed and constructed for the original Coastal. Coastal airship No. 1 was commissioned towards the end of 1915 and was retained solely for experimental and training purposes. Approximately thirty of these airships were constructed during the year 1916, and were allocated to the various stations for patrol duties. The work carried out by these ships during the two and a half years in which they were in commission, is worthy of the highest commendation. Before the advent of later and more reliable ships, the bulk of anti-submarine patrol on the east coast and south-west coast of England was maintained by the Coastal. On the east coast, with the prevailing westerly and south-westerly winds, these airships had many long and arduous voyages on their return from patrol, and in the bitterness of winter their difficulties were increased ten-fold. To the whole-hearted efforts of Coastal pilots and crews is due, to a great extent, the recognition which somewhat tardily was granted to the Airship Service. The envelope of the Coastal airship has been shown to be of 170,000 cubic feet capacity. It is trilobe in section to employ the Astra-Torres system of internal and external rigging. The great feature of this principle is that it enables the car to be slung much closer to the envelope than would be possible with the tangential system on an envelope of this size. As a natural consequence there is far less head resistance, owing to the much shorter rigging, between the envelope and the car. The shape of the envelope is not all that could have been desired, for it is by no means a true streamline, but has the same cross section for the greater part of its length, which tapers at either end to a point which is slightly more accentuated aft. Owing to the shape, these ships, in the early days until experience had been gained, were extremely difficult to handle, both on the landing ground and also in the air. They were extremely unstable both in a vertical and horizontal plane, and were slow in answering to their rudders and elevators. The envelope is composed of rubber-proofed fabric doped to hold the gas and resist the effects of weather. Four ballonets are situated in the envelope, two in each of the lower lobes, air being conveyed to them by means of a fabric air duct, which is parallel to the longitudinal centre line of the envelope, with transverse ducts connecting each pair of ballonets. In earlier types of the Coastal, the air scoop supplying air to the air duct was fitted in the slip stream of the forward engine, but later this was fitted aft of the after engine. Six valves in all are used, four air valves, one fitted to each ballonet, and two gas valves. These are situated well aft, one to each of the lower lobes, and are fitted on either side of the rudder plane. A top valve is dispensed with because in practice when an Astra-Torres envelope loses shape, the tendency is for the tail to be pulled upwards by the rigging, with the result that the two gas valves always remain operative. Crabpots and non-return valves are employed in a similar manner to S.S. airships. The Astra-Torres system of internal rigging must now be described in some detail. The envelope is made up of three longitudinal lobes, one above and two below, which when viewed end on gives it a trefoil appearance. The internal rigging is attached to the ridges formed on either side of the upper lobe, where it meets the two side lobes. From here it forms a V, when viewed cross sectionally, converging at he ridge formed by the two lobes on the underside of the envelope which is known as the lower ridge. To the whole length of the top ridges are attached the internal rigging girdles and also the lacing girdles to which are secured the top and side curtains. These curtains are composed of ordinary unproofed fabric and their object is to make the envelope keep its trilobe shape. They do not, however, divide the ship into separate gas compartments. The rigging girdle consists of a number of fabric scallops through which run strands of Italian hemp. These strands, of which there are a large number, are led towards the bottom ridge, where they are drawn together and secured to a rigging sector. To these sectors the main external rigging cables are attached. The diagram shows better than any description this rigging system. Ten main suspensions are incorporated in the Coastal envelope, of which three take the handling guys, the remaining seven support the weight of the car. The horizontal fins with the elevator flaps, and the vertical fin with the rudder flap, are fixed to the ridges of the envelope. The car was evolved in the first instance by cutting away the tail portion of two Avro seaplane fuselages and joining the forward portions end on, the resulting car, therefore, had engines at either end with seating accommodation for four. The landing chassis were altered, single skids being substituted for the wider landing chassis employed in the seaplane. The car consists of four longerons with struts vertical and cross, and stiffened with vertical and cross bracing wires. The sides are covered with fabric and the flooring and fairing on the top of the car are composed of three-ply wood. In the later cars five seats were provided to enable a second officer to be carried. The engines are mounted on bearers at each end of the car, and the petrol and oil tanks were originally placed adjoining the engines in the car. At a later date various methods of carrying the petrol tanks were adopted, in some cases they were slung from the envelope and in others mounted on bearers above the engines. Wireless telegraphy is fitted as is the case with all airships. In the Coastal a gun is mounted on the top of the envelope, which is reached by a climbing shaft passing through the envelope, another mounting being provided on the car itself. Bombs are also carried on frames attached to the car. Sunbeam engines originally supplied the motive power, but at a later date a 220 horse-power Renault was fitted aft and a 100 horse-power, Berliet forward. With the greater engine power the ship's capabilities were considerably increased. Exceedingly long flights were achieved by this type of ship, and those exceeding ten hours are far too numerous to mention. The most noteworthy of all gave a total of 24 1/4 hours, which, at the time, had only once been surpassed by any British airship. Towards the end of 1917, these ships, having been in commission for over two years, were in many cases in need of a complete refit. Several were put in order, but it was decided that this policy should not be continued, and that as each ship was no longer fit for flying it should be replaced by the more modern Coastal known as the C Star. The record of one of these ships so deleted is surely worthy of special mention. She was in commission for 2 years 75 days, and averaged for each day of this period 3 hours 6 minutes flying. During this time she covered upwards of 66,000 miles. From this it will be seen that she did not pass her life by any means in idleness. "C STAR" AIRSHIP After considerable experience had been gained with the Coastal, it became obvious that a ship was required of greater capabilities to maintain the long hours of escort duty and also anti-submarine patrols. To meet these requirements it was felt that a ship could be constructed, not departing to any extent from the Coastal, with which many pilots were now quite familiar, but which would show appreciable improvement over its predecessor. The design which was ultimately adopted was known as the C Star, and provided an envelope of 210,000 cubic feet, which secured an extra ton and a quarter in lifting capacity. This envelope, although of the Astra-Torres type, was of streamline form, and in that respect was a great advance on the early shape as used in the Coastal. It is to all intents and purposes the same envelope as is used on the North Sea ships, but on a smaller scale. An entirely new type of fabric was employed for this purpose. The same model of car was employed, but was made more comfortable, the canvas covering for the sides being replaced by three-ply wood. In all other details the car remained entirely the same. The standard power units were a 100 horse-power Berliet forward and a Fiat of 260 horse-power aft. The petrol tanks in this design were carried inside the envelope, which was quite a new departure. These airships may be considered to have been successful, though not perhaps to the extent which was expected by their most ardent admirers. With the advent of the S.S. Twin it was resolved not to embark on a large constructional programme, and when the numbers reached double figures they were no longer proceeded with. Notwithstanding this the ships which were commissioned carried out most valuable work, and, like their prototypes, many fine flights were recorded to their credit. Thirty-four and a half hours was the record flight for this type of ship, and another but little inferior was thirty hours ten minutes. These flights speak well for the endurance of the crews, as it must be borne in mind that no sleeping accommodation is possible in so small a car. The Coastal airship played no small part in the defeat of the submarine, but its task was onerous and the enemy and the elements unfortunately exacted a heavy toll. A German wireless message received in this country testified to the valiant manner in which one of these ships met with destruction. THE "NORTH SEA" AIRSHIP The North Sea or N.S. airship was originally designed to act as a substitute for the Rigid, which, in 1916, was still a long way from being available for work of practical utility. From experience gained at this time with airships of the Coastal type it was thought possible to construct a large Non-Rigid capable of carrying out flights of twenty-four hours' duration, with a speed of 55 to 60 knots, with sufficient accommodation for a double crew. The main requirements fall under four headings: 1. Capability to carry out flights of considerable duration. 2. Great reliability. 3. The necessary lift to carry an ample supply of fuel. 4. Adequate arrangements to accommodate the crew in comfort. If these could be fulfilled the authorities were satisfied that ships possessing these qualifications would be of value to the Fleet and would prove efficient substitutes until rigid airships were available. The North Sea, as may be gathered from its name, was intended to operate on the east coasts of these islands. The first ship, when completed and put through her trials, was voted a success, and the others building were rapidly pushed on with. When several were finished and experience had been gained, after long flights had been carried out, the North Sea airship suffered a partial eclipse and people were inclined to reconsider their favourable opinion. Thus it was that for many months the North Sea airship was decidedly unpopular, and it was quite a common matter to hear her described as a complete failure. The main cause of the prejudice was the unsatisfactory design of the propelling machinery, which it will be seen later was modified altogether, and coupled with other improvements turned a ship of doubtful value into one that can only be commended. The envelope is of 360,000 cubic feet capacity, and is designed on the Astra-Torres principle for the same reasons as held good in the cases of the Coastal and C Star. All the improvements which had been suggested by the ships of that class were incorporated in the new design, which was of streamline shape throughout, and looked at in elevation resembled in shape that of the S.S. airship. Six ballonets are fitted, of which the total capacity is 128,000 cubic feet, equivalent to 35.5 per cent of the total volume. They are fitted with crabpots and non-return valves in the usual manner. The rigging is of the Astra-Torres system, and in no way differs from that explained in the previous chapter. Nine fans of the internal rigging support the main suspensions of the car, while similar fans both fore and aft provide attachment for the handling guys. Auxiliary fans on the same principle support the petrol tanks and ballast bag. Four gas and six air valves in all are fitted, all of which are automatic. Two ripping panels are embodied in the top lobe of the envelope. The N.S. ship carries four fins, to three of which are attached the elevator and rudder flaps. The fourth, the top fin, is merely for stabilizing purposes, the other three being identical in design, and are fitted with the ordinary system of wiring and kingposts to prevent warping. The petrol was originally carried in aluminium tanks disposed above the top ridges of the envelope, but this system was abandoned owing to the aluminium supply pipes becoming fractured as the envelope changed shape at different pressures. They were then placed inside the envelope, and this rearrangement has given every satisfaction. To the envelope of the N.S. is rigged a long covered-in car. The framework of this is built up of light steel tubes, the rectangular transverse frames of which are connected by longitudinal tubes, the whole structure being braced by diagonal wires. The car, which tapers towards the stern, has a length of 85 feet, with a height of 6 feet. The forward portion is covered with duralumin sheeting, and the remainder with fabric laced to the framework. Windows and portholes afford the crew both light and space to see all that is required. In the forward portion of the car are disposed all the controls and navigating instruments, together with engine-telegraphs and voice pipes. Aft is the wireless telegraphy cabin and sleeping accommodation for the crew. A complete electrical installation is carried of two dynamos and batteries for lights, signalling lamps, telephones, etc. The engines are mounted in a power unit structure separate from the car and reached by a wooden gangway supported by wire cables. This structure consists of two V-shaped frameworks connected by a central frame and by an under-structure to which floats are attached. The mechanics' compartment is built upon the central frame, and the engine controls are operated from this cabin. In the original power units two 250 horse-power Rolls Royce engines were fitted, driving propellers on independent shafts through an elaborate system of transmission. This proved to be a great source of weakness, as continual trouble was experienced with this method, and a fracture sooner or later occurred at the universal joint nearest to the propeller. When the modified form of ship was built the whole system of transmission was changed, and the propellers were fitted directly on to the engine crankshafts. At a later date 240 horse-power Fiat engines were installed, and the engineers' cabin was modified and an auxiliary blower was fitted to supply air to the ballonets for use if the engines are not running. In the N.S. ship as modified the car has been raised to the same level as the engineers' cabin, and all excrescences on the envelope were placed inside. This, added to the improvement effected by the abolition of the transmission shafts, increased the reliability and speed of the ship, and also caused a reduction in weight. The leading dimensions of the ship are as follows: length, 262 feet; width, 56 feet 9 inches; height, 69 feet 3 inches. The gross lift is 24,300 lb.; the disposable lift, without crew, petrol, oil, and ballast, 8,500 lb. The normal crew carried when on patrol is ten, which includes officers. As in the case of the Coastal, a gun is mounted on the top of the envelope, which is approached by a similar climbing shaft, and guns and bombs are carried on the car. These ships have become notorious for breaking all flying records for non-rigid airships. Even the first ship of the class, despite the unsatisfactory power units, so long ago as in the summer of 1917 completed a flight of 49 hours 22 minutes, which at the time was the record flight of any British airship. Since that date numerous flights of quite unprecedented duration have been achieved, one of 61 1/2 hours being particularly noteworthy, and those of upwards of 30 hours have become quite commonplace. Since the Armistice one of these ships completed the unparalleled total of 101 hours, which at that date was the world's record flight, and afforded considerable evidence as to the utility of the non-rigid type for overseas patrol, and even opens up the possibility of employing ships of similar or slightly greater dimensions for commercial purposes. N.S. 6 appeared several times over London in the summer months of 1918, and one could not help being struck by the ease with which she was steered and her power to remain almost stationary over such a small area as Trafalgar Square for a quite considerable period. The flights referred to above were not in any way stunt performances to pile up a handsome aggregate of hours, but were the ordinary flying routine of the station to which the ships were attached, and most of the hours were spent in escorting convoys and hunting for submarines. In addition to these duties, manoeuvres were carried out on occasions with the Fleet or units thereof. From the foregoing observations it must be manifest that this type of ship, in its present modified state, is a signal success, and is probably the best large non-rigid airship that has been produced in any country. For the purposes of comparison it will be interesting to tabulate the performances of the standard types of non-rigid airships. The leading dimensions are also included in this summary: Type S.S. Zero S.S. Twin Coastal North Star Sea Length 143' 0" 165' 0" 218' 0" 262' 0" Overall width 32' 0" 35' 6" 49' 3" 56' 9" Overall height 46' 0" 49' 0" 57' 6" 69' 3" Hydrogen capacity (cubic feet) 70,000 100,000 210,000 360,000 Gross lift (lb.) 4,900 7,000 14,500 24,300 Disposable lift (lb.) 1,850 2,200 4,850 8,500 Crew 3 4 5 10 Lift available for fuel and freight (lb.) 1,370 1,540 4,050 6,900 Petrol consumption at full speed (lb. per hour) 3.6 7.2 18.4 29.8 Gals. per hour 0.36 0.72 2.05 3 CHAPTER VII NAVAL AIRSHIPS.--THE RIGIDS--RIGID AIRSHIP No. 1 The responsibility for the development the Rigid airship having been allotted to the Navy, with this object in view, in the years 1908 and 1909 a design was prepared by Messrs. Vickers Ltd., in conjunction with certain naval officers, for a purely experimental airship which should be as cheap as possible. The ship was to be known as Naval Airship No. 1, and though popularly called the Mayfly, this title was in no way official. In design the following main objects were aimed at: 1. The airship was to be capable of carrying out the duties of an aerial scout. 2. She was to be able to maintain a speed of 40 knots for twenty-four hours, if possible. 3. She was to be so designed that mooring to a mast on the water was to be feasible, to enable her to be independent of her shed except for docking purposes, as in the case with surface vessels. 4. She was to be fitted with wireless telegraphy. 5. Arrangements were to be made for the accommodation of the crew in reasonable comfort. 6. She was to be capable of ascending to a height of not less than 1,500 feet. These conditions rendered it necessary that the airship should be of greater dimensions than any built at the time, together with larger horse-power, etc. These stipulations having been settled by the Admiralty, the Admiralty officials, in conjunction with Messrs. Vickers Ltd., determined the size, shape, and materials for the airship required. The length of the ship was fixed at approximately 500 feet, with a diameter of 48 feet. Various shapes were considered, and the one adopted was that recommended by an American professor named Zahm. In this shape, a great proportion of the longitudinal huff framework is parallel sided with curved bow and stern portions, the radius of these curved portions being, in the case of the bow, twice the diameter of the hull, and in the case of the stern nine times the same diameter. Experiments proved that the resistance of a ship of this shape was only two-fifths of the resistance of a ship of the same dimensions, having the 1 1/2 calibre bow and stern of the Zeppelin airships at that time constructed. A considerable difference of opinion existed as to the material to be chosen for the construction of the hull. Bamboo, wood, aluminium, or one of its alloys, were all considered. The first was rejected as unreliable. The second would have been much stronger than aluminium, and was urged by Messrs. Vickers. The Admiralty, however, considered that there was a certainty of better alloys being produced, and as the ship was regarded as an experiment and its value would be largely negatived if later ships were constructed of a totally different material, aluminium or an alloy was selected. The various alloys then in existence showed little advantage over the pure metal, so pure aluminium was specified and ordered. This metal was expected to have a strength of ten tons per square inch, but that which arrived was found to be very unreliable, and many sections had, on test, only half the strength required. The aluminium wire intended for the mesh wiring of the framework was also found to be extremely brittle. A section of the framework was, however, erected, and also one of wood, as a test for providing comparisons. In the tests, the wooden sections proved, beyond all comparison, the better, but the Admiralty persisted in their decision to adopt the metal. Towards the end of 1909 a new aluminium alloy was discovered, known as duralumin. Tests were made which proved that this new metal possessed a strength of twenty-five tons per square inch, which was over twice as strong as the nominal strength of aluminium, and in practice was really five times stronger. The specific gravity of the new metal varied from 2.75 to 2.86, as opposed to the 2.56 of aluminium. As the weights were not much different it was possible to double the strength of the ship and save one ton in weight. Duralumin was therefore at once adopted. The hull structure was composed of twelve longitudinal duralumin girders which ran fore and aft the length of the ship and followed the external shape. The girders were secured to a steel nose-piece at the bow and a pointed stern-piece aft. These girders, built of duralumin sections, were additionally braced wherever the greatest weights occurred. To support these girders in a thwartship direction a series of transverse frames were placed at 12 feet 6 inches centres throughout the length of the ship, and formed, when viewed cross-sectionally, a universal polygon of twelve sides. For bracing purposes mesh wiring stiffened each bay longitudinally, so formed by the junction of the running girder and the transverse frames, while the transverse frames between the gasbags were stiffened with radial wiring which formed structure similar to a wheel with its spokes. The frames where the gondolas occurred were strengthened to take the addition weight, while the longitudinals were also stiffened at the bow and stern. Communication was provided between the gondolas by means of an external keel which was suspended from extra keel longitudinals. In this design the keel was provided for accommodation purposes only, and in no way increased the structural stability of the ship as in No. 9 and later ships. This keel, triangular in section, widened out amidships to form a space for a cabin and the wireless compartment. The fins and rudders, which were adopted, were based entirely on submarine experience, and the Zeppelin method was ignored. The fins were fitted at the stern of the ship only, and comprised port and starboard horizontal fins, which followed approximately the shape of the hull, and an upper and lower vertical fin. Attached to these fins were box rudders and elevators, instead of the balanced rudders first proposed. Auxiliary rudders were also fitted in case of a breakdown of the main steering gear abaft the after gondola. Elevators and rudders were controlled from the forward gondola and the auxiliary rudders from the after gondola. The gasbags were seventeen in number and were twelve-sided in section, giving approximately a volume of 663,000 cubic feet when completely full. Continental fabric, as in use on the Zeppelin airships, was adopted, although the original intention was to use gold-beater's skin, but this was abandoned owing to shortage of material. These bags were fitted with the Parseval type of valve, which is situated at the top, contrary to the current Zeppelin practice, which had automatic valves at the bottom of the bags, and hand-operated valves on the top of a few bags for control purposes. Nets were laced to the framework to prevent the bags bulging through the girders. The whole exterior of the hull was fitted with an outer cover; Zeppelin at this time used a plain light rubber-proofed fabric, but this was not considered suitable for a ship which was required to be moored in the open, as in wet weather the material would get saturated and water-logged. Various experiments were carried out with cotton, silk and ramie, and, as a result, silk treated with Ioco was finally selected. This cover was laced with cords to the girder work, and cover-strips rendered the whole impervious to wet. Fire-proofed fabric was fitted in wake of the gondolas for safety from the heat of the engines. Two gondolas, each comprising a control compartment and engine-room, were suspended from the main framework of the hull. They were shaped to afford the least resistance possible to the air, and were made of Honduras mahogany, three-ply where the ballast tanks occurred, and two-ply elsewhere. The plies were sewn together with copper wire. The gondolas were designed to have sufficient strength to withstand the strain of alighting on the water. They were suspended from the hull by wooden struts streamline in shape, and fitted with internal steel-wire ropes; additional wire suspensions were also fitted to distribute the load over a greater length of the ship. The engines were carried in the gondolas on four hollow wooden struts, also fitted internally with wire. The wires were intended to support the gondolas in the event of the struts being broken in making a heavy landing. Two engines were mounted, one in each gondola, the type used being the 8-cylinder vertical water-cooled Wolseley developing a horse-power of 160. The forward engine drove two wing propellers through the medium of bevel gearing, while the after engine drove a single large propeller aft through 4 gear box to reduce the propeller revolutions to half that of the engine. The estimated speed of the ship was calculated to be 42 miles per hour, petrol was carried in tanks, fitted in the keel, and the water ballast tanks were placed close to the keel and connected together by means of a pipe. No. 1 was completed in May, 1911. She had been built at Barrow in a shed erected on the edge of Cavendish Dock. Arrangements were made that she should be towed out of the shed to test her efficiency at a mooring post which had been prepared in the middle of the dock. She was launched on May 22nd in a flat calm and was warped out of the shed and hauled to the post where she was secured without incident. The ship rode at the mooring post in a steady wind, which at one time increased to 36 miles per hour, until the afternoon of May 25th, and sustained no damage whatever. Various engine trials were carried out, but no attempt was made to fly, as owing to various reasons the ship was short of lift. Valuable information was, however, gained in handling the ship, and much was learnt of her behaviour at the mast. More trouble was experienced in getting her back into the shed, but she was eventually housed without sustaining any damage of importance. Owing to the lack of disposable lift, the bags were deflated and various modifications were carried out to lighten the ship, of which the principal were the removal of the keel and cabin entirely, and the removal of the water-trimming services. Other minor alterations were made which gave the ship, on completion, a disposable lift of 3.21 tons. The transverse frames between the gasbags were strengthened, and a number of broken wires were replaced. On September 22nd the ship was again completed, and on the 24th she was again to be taken out and tested at the mooring post. Unfortunately, while being hauled across the dock, the framework of the ship collapsed, and she was got back into the shed the same day. Examination showed that it was hopeless to attempt to reconstruct her, and she was broken up at a later date. The failure of this ship was a most regrettable incident, and increased the prejudice against the rigid airship to such an extent that for some time the Navy refused to entertain any idea of attempting a second experiment. RIGID AIRSHIP No. 9 Rigid Airship No. 1 having met with such a calamitous end, the authorities became rather dubious as to the wisdom of continuing such costly experiments. Most unfortunately, as the future showed and as was the opinion of many at the time, rigid construction in the following year 1912 was ordered to be discontinued. This decision coincided with the disbanding of the Naval Air Service, and for a time rigid airships in this country were consigned to the limbo of forgetfulness. After the Naval Air Service had been reconstituted, the success which attended the Zeppelin airships in Germany could no longer be overlooked, and it was decided to make another attempt to build a rigid airship in conformity with existing Zeppelin construction. The first proposals were put forward in 1913, and, finally, after eleven months delay, the contract was signed. This airship, it has been seen, was designated No. 9. No. 9 experienced numerous vicissitudes, during the process of design and later when construction was in progress. The contract having been signed in March, 1914, work on the ship was suspended in the following February, and was not recommenced until July of the same year. From that date onwards construction was carried forward; but so many alterations were made that it was fully eighteen months before the ship was completed and finally accepted by the Admiralty. The ship as designed was intended "to be generally in conformity with existing Zeppelin construction," with the following main requirements stipulated for in the specification: 1. She was to attain a speed of at least 45 miles per hour at the full power of the engines. 2. A minimum disposable lift of five tons was to be available for movable weights. 3. She was to be capable of rising to a height of 2,000 feet during flight. The design of this ship was prepared by Messrs. Vickers, Ltd., and as it was considered likely that owing to inexperience the ship would probably be roughly handled and that heavy landings might be made, it was considered that the keel structure and also the cars should be made very strong in case of accidents occurring. This, while materially increasing the strength of the ship, added to its weight, and coupled with the fact that modifications were made in the design, rendered the lift somewhat disappointing. The hull structure was of the "Zahm" shape as in No. 1, a considerable portion being parallel sided, while in transverse section it formed a 17-sided polygon. In length it was 526 feet with a maximum diameter of 53 feet. The hull framework was composed of triangular duralumin girders, both in the longitudinal and transverse frames, while the bracing was carried out by means of high tensile steel wires and duralumin tubes. Attached to the hull was a V-shaped keel composed of tubes with suitable wire bracings, and in it a greater part of the strength of the structure lay. It was designed to withstand the vertical forces and bending moments which resulted from the lift given by the gasbags and the weights of the car and the cabin. The keel also provided the walking way from end to end of the ship, and amidships was widened out to form a cabin and wireless compartment. The wiring of the transverse frames was radial and performed similar functions to the spokes of a bicycle wheel. These wires could be tightened up at the centre at a steel ring through which they were threaded and secured by nuts. In addition to the radial wires were the lift wires, which were led to the two points on the transverse frames which were attached to the keel; on the inflation of the gasbags, the bags themselves pressed upon the longitudinal girders on the top of the ship, which pressure was transferred to the transverse frames and thence by means of the several lift wires to the keel. In this way all the stresses set up by the gas were brought finally to the keel in which we have already said lay the main strength of the ship. The hull was divided by the transverse frames into seventeen compartments each containing a single gasbag. The bags were composed of rubber-proofed fabric lined with gold-beater's skin to reduce permeability, and when completely full gave a total volume of 890,000 cubic feet. Two types of valve were fitted to each bag, one the Parseval type of valve with the pressure cone as fitted in No. 1, the other automatic but also controlled by hand. To distribute the pressure evenly throughout the upper longitudinal frames, and also to prevent the gasbags bulging between the girders, nets were fitted throughout the whole structure of the hull. The whole exterior of the ship was fitted with an outer cover, to protect the gasbags and hull framework from weather and to render the outer surface of the ship symmetrical and reduce "skin friction" and resistance to the air to a minimum. To enable this cover to be easily removed it was made in two sections, a port and starboard side for each gasbag. The covers were laced to the hull framework and the connections were covered over with sealing strips to render the whole weathertight. The system of fins for stabilizing purposes on No. 9 were two--vertical and horizontal. The vertical fin was composed of two parts, one above and the other below the centre line of the ship. They were constructed of a framework of duralumin girders, covered over with fabric. The fins were attached on one edge to the hull structure and wire braced from the other edge to various positions on the hull. The horizontal fins were of similar design and attached in a like manner to the hull. Triplane rudders and biplane elevators of the box type were fitted in accordance with the German practice of the time. Auxiliary biplane rudders were fitted originally abaft the after car, but during the first two trial flights they proved so very unsatisfactory that it was decided to remove them. Two cars or gondolas were provided to act as navigating compartments and a housing for the engines, and in design were calculated to offer the least amount of head resistance to the wind. The cars were composed of duralumin girders, which formed a flooring, a main girder running the full length of the car with a series of transverse girders spaced in accordance with the main loads. From each of these transverse girders vertical standards with a connecting piece on top were taken and the whole exterior was covered with duralumin plating. The cars were suspended in the following manner. Two steel tubes fitting into a junction piece at each end were bolted to brackets at the floor level at each end of the transverse girders. They met at an apex above the roof level and were connected to the tubing of the keel. In addition, to distribute the weight and prevent the cars from rocking, steel wire suspensions were led to certain fixed points in the hull. Each car was divided into two parts by a bulkhead, the forward portion being the control compartment in which were disposed all instruments, valve and ballast controls, and all the steering and elevating arrangements. Engine-room telegraphs, voice pipes and telephones were fitted up for communication from one part of the ship to the other. The keel could be reached by a ladder from each car, thus providing with the climbing shaft through the hull access to all parts of the ship. The original engine equipment of No. 9 was composed of four Wolseley-Maybach engines of 180 horse-power each, two being installed in the forward car and two in the after car. As the ship was deficient in lift after the initial flight trials had been carried out, it was decided to remove the two engines from the after car and replace them with a single engine of 250 horse-power; secondly, to remove the swivelling propeller gear from the after car and substitute one directly-driven propeller astern of the car. This as anticipated reduced the weight very considerably and in no way lessened the speed of the ship. The forward engines drove two four-bladed swivelling propellers through gear boxes and transmission shafts, the whole system being somewhat complicated, and was opposed to the Zeppelin practice at the time which employed fixed propellers. The after engine drove a large two-bladed propeller direct off the main shaft. The petrol and water ballast were carried in tanks situated in the keel and the oil was carried in tanks beneath the floors of the cars. The wireless cabin was situated as before mentioned in a cabin in the keel of the ship, and the plant comprised a main transmitter, an auxiliary transmitter and receiver and the necessary aerial for radiating and receiving. No. 9 was inflated in the closing days of 1916, and the disposal lift was found to be 2.1 tons under the specification conditions, namely, barometer 29.5 inches and temperature 55 degrees Fahrenheit. The contract requirements had been dropped to 3.1 tons, which showed that the ship was short by one ton of the lift demanded. The flight trials were, however, carried out, which showed that the ship had a speed of about 42 1/2 miles per hour. The alterations previously mentioned were afterwards made, the bags of the ship were changed and another lift and trim trial was held in March, 1917, when it was found that these had had the satisfactory result of increasing the disposable lift to 3.8 tons or .7 ton above the contract requirements, and with the bags 100 per cent full gave a total disposable lift of 5.1 tons. Additional trials were then carried out, which showed that the speed of the ship had not been impaired. For reference purposes the performances of the ship are tabulated below. Speed: Full 45 miles per hour Normal = 2/3 38 " " " Cruising = 1/3 32 " " " Endurance: Full 18 hours = 800 miles Normal 26 " = 1,000 " Cruising 50 " = 1,600 " No. 9 having finished her trials was accepted by the Admiralty in Mar. 1917, and left Barrow, where she had been built, for a patrol station. In many ways she was an excellent ship, for it must be remembered that when completed she was some years out-of-date judged by Zeppelin standards. Apart from the patrol and convoy work which she accomplished, she proved simply invaluable for the training of officers and men selected to be the crews of future rigid airships. Many of these received their initial training in her, and there were few officers or men in the airship service who were not filled with regret when orders were issued that she was to be broken up. The general feeling was that she should have been preserved as a lasting exhibition of the infancy of the airship service, but unfortunately rigid airships occupy so much space that there is no museum in the country which could have accommodated her. So she passed, and, except for minor trophies, remains merely a recollection. RIGID AIRSHIP No. 23 CLASS After the decision had been made in 1915 that work on No. 9 should be restarted, the Admiralty determined that a programme of rigid airships should be embarked upon, and design was commenced. Several ships of the same class were, ordered, and the type was to be known as the 23 class. Progress on these ships, although slow, was more rapid than had been the case with No. 9, and by the end of 1917 three were completed and a fourth was rapidly approaching that state. The specification, always ambitious, laid down the following main stipulations. (1) The ship is to attain a speed of at least 55 miles per hour for the main power of the engines. (2) A minimum of 8 tons is to be available for disposable weights when full. (3) The ship must be capable of rising at an average rate of not less than 1,000 feet per minute, through a height of 3,000 feet starting from nearly sea level. As will be seen later this class of ship, although marking a certain advance on No. 9 both as regards workmanship and design, proved on the whole somewhat disappointing, and it became more evident every day that we had allowed the Germans to obtain such a start in the race of airship construction as we could ill afford to concede. We may here state that all of the ships of this class which had been ordered were not completed, the later numbers being modified into what was known as the 23 X class; four in all of the 23 class were built, of which two--Nos. 23 and 26--were built by Messrs. Vickers, Ltd., at Barrow, No. 24 by Messrs. Wm. Beardmore and Co., at Glasgow, and No. 25 by Messrs. Armstrong, Whitworth and Co., at Selby, Yorkshire. In many respects the closest similarity of design exists between No. 9 and No. 23, especially in the hull, but it will be of interest to mention the salient differences between the two ships. The length of the hull, which in No. 9 was 520 feet, was increased in No. 23 to 535 feet, and the number of gasbags from seventeen to eighteen. This gave a total volume of 997,500 cubic feet compared with 890,000 cubic feet in No. 9, with a disposable lift under specification conditions of 5.7 tons as opposed to 3.8 tons. The longitudinal shape of No. 23 is a modified form of "Zahm" shape, the radius of the bow portion being twice the diameter of the parallel portion, while the stern radius is three times the same diameter. In design the hull framework is almost a repetition of No. 9, particularly in the parallel portion, the same longitudinal and transverse frames dividing the hull into compartments, with tubes completely encircling the section between each main transverse frame. The system of wiring the hull is precisely the same in both the ships, and nets are employed in the same way. The triangular section of keel is adhered to, but its functions in No. 23 are somewhat different. In No. 9 it was intended to be sufficiently strong to support all the main vertical bending moments and shearing forces, but in No. 23 it was primarily intended to support the distributed weights of water ballast, petrol tanks, etc., between the main transverse frames. Unlike No. 9, the keel is attached to the main transverse frames only. The cabin and wireless cabin are disposed in the keel in the same manner, and it also furnishes a walking way for the total length of the ship. The stabilizing fins, both vertical and horizontal, are similar to those attached to No. 9, but the system of rudders and elevators is totally different. In place of the box rudders and elevators in No. 9, single balanced rudders and elevators are attached to the fins; they have their bearing on the outboard side on the external girders of the fins, which are extended for the purpose. The elevators and rudders are composed of a duralumin framework, stiffened by a kingpost on either side with bracing wires. The bags, eighteen in number, are made of rubber-proofed fabric lined with gold-beater's skin. It is interesting to note that the number of skins used for the bags of a ship of this class is approximately 350,000. The system of valves is entirely different from that in No. 9. The Parseval type of valve with the pressure cone at the bottom of the bag is omitted, and in the place of the two top valves in the former ship are a side valve of the Zeppelin type entirely automatic and a top valve entirely hand controlled. The side valve is set to blow off at a pressure of from 3 to 5 millimetres. The outer cover was fitted in the same manner as in No. 9. Two cars or gondolas, one forward, the other aft, each carry one engine provided with swivelling propellers and gears. They are enclosed with sides and a fireproof roof, and are divided into two compartments, one the navigating compartment, the other the engine room. The cars are in all respects very similar to those of No. 9, and are suspended from the hull in a similar manner. The remaining two engines are carried in a small streamline car situated amidships, which has just sufficient room in it for the mechanics to attend to them. Originally this car was open at the top, but it was found that the engineers suffered from exposure, and it was afterwards roofed in. The engine arrangements in this ship were totally different to those of No. 9, four 250 horse-power Rolls Royce engines being installed in the following order. Single engines are fitted in both the forward and after cars, each driving two swivelling four-bladed propellers. In the centre car two similar engines are placed transversely, which drive single fixed propellers mounted on steel tube outriggers through suitable gearing. The engines are the standard 12 cylinder V-type Rolls Royce which will develop over 300 brake horse-power at full throttle opening. The engine is water cooled, and in the case of those in the forward and after cars the original system consisted of an internal radiator supplied by an auxiliary water tank carried in the keel. It was found on the flight trials that the cooling was insufficient, and external radiators were fitted, the internal radiator and fan being removed. In the case of the centre car no alteration was necessary, as external radiators were fitted in the first instance. The engines are supported by two steel tubes held by four brackets bolted to the crank case, these being carried by twelve duralumin tubes bolted to the bearers and transverse frames of the car respectively. The drive from the engine is transmitted through a universal joint to a short longitudinal shaft, running on ball bearings. This shaft gears into two transverse shafts, which drive the propellers through the medium of a gear box to the propeller shafts, making five shafts in all. The engines in the centre car being placed transversely the transmission is more direct, the engines driving the propellers through two gear wheels only. The propeller gear box is supported by steel tube outriggers attached by brackets to the framework of the car. The petrol is carried in a series of tanks situated beneath the keel walking way, and are interconnected so that any tank either forward or aft can supply any engine, by this means affording assistance for the trimming of the ship. Four-bladed propellers are used throughout the ship. Water ballast is carried in fabric bags also situated beneath the keel walking way, and a certain amount is also carried beneath the floor of the car. Engine-room telegraphs, swivelling propeller telegraphs, speaking tubes and telephones, with a lighting set for the illumination of the cars and keel, were all fitted in accordance with the practice standard in all rigid airships. The lift and trim trials taken before the initial flight trials showed that the ship possessed a disposable lift under standard conditions of 5.7 tons. The original disposable lift demanded by the specification was 3 tons but this was reduced by 2 tons owing to the machinery weights being 2 tons in excess of the estimate. Since then these weights had been increased by another half-ton, making a total of 2 1/2 tons over the original estimate. It was evident that with so small a margin of lift these ships would never be of real use, and it was decided to remove various weights to increase the lift and to substitute a wing car of a similar type to those manufactured for the R 33 class for the heavy after car at present in use. R 23 carried out her trials without the alteration to the car, which was effected at a later date, and the same procedure was adopted with R 24 and R 25. In the case of R 26, however, she had not reached the same stage of completion as the other two ships, and the alterations proposed for them were embodied in her during construction. The gasbags were of lighter composition, all cabin furniture was omitted and the wing car was fitted in place of the original after car. This wing car is of streamline shape with a rounded bow and tapered stern. The lower portion is plated with duralumin sheets and the upper part is covered with canvas attached to light wooden battens to give the necessary shape. This effected a very considerable reduction in weight. The original 250 horse-power Rolls Royce engine was installed, now driving a single large two-bladed propeller astern. A test having been taken, it was found that the disposable lift under standard conditions was 6.28 tons. It was therefore decided that all the ships of the class should be modified to this design when circumstances permitted. Speed trials were carried out under various conditions of running, when it was found that the ship possessed a speed of 54 1/4 miles per hour with the engines running full out. To summarize the performances of these ships as we did in the case of No. 9, we find: Speed: Full 54 miles per hour Normal =2/3 48 " " " Cruising =1/3 33 " " " Endurance: Full 18 hours = 1,000 miles Normal 26 " = 1,250 " Cruising 50 " = 1,900 " The production of the rigid airship during the war was always surrounded with a cloak of impenetrable mystery. Few people, except those employed on their construction or who happened to live in the immediate vicinity of where they were built, even knew of their existence, and such ignorance prevailed concerning airships of every description that the man in the street hailed a small non-rigid as "the British Zeppelin" or admired the appearance of R 23 as "the Silver Queen." The authorities no doubt knew their own business in fostering this ignorance, although for many reasons it was unfortunate that public interest was not stimulated to a greater degree. In the summer months of 1918, however, they relented to a certain extent, and R 23 and one of her sister ships were permitted to make several flights over London to the intense delight of thousands of its inhabitants, and a certain amount of descriptive matter appeared in the Press. From that time onwards these large airships have completely captured the popular imagination, and many absurd rumours and exaggerations have been circulated regarding their capabilities. It has been gravely stated that these airships could accomplish the circuit of the globe and perform other feats of the imagination. It must be confessed that their merits do not warrant these extravagant assertions. The fact remains, however, that R 23 and her sister ship R 26 have each carried out patrols of upwards of 40 hours duration and that, similarly to No. 9, they have proved of the greatest value for training airship crews and providing experience and data for the building programme of the future. At the present time highly interesting experiments are being carried out with them to determine the most efficient system of mooring in the open, which will be discussed at some length in the chapter dealing with the airship of the future. RIGID AIRSHIP 23 X CLASS During the early days of building the airships of the 23 class, further information was obtained relating to rigid airship construction in Germany, which caused our designers to modify their views. It was considered a wrong policy to continue the production of a fleet of ships the design of which was becoming obsolete, and accordingly within ten months of placing the order for this class a decision was reached that the last four ships were to be altered to a modified design known as the 23 X class. As was the case with the ships of the preceding class when nearing completion, they were realized to be out of date, and special efforts being required to complete the ships of the 33 class and to release building space for additional larger ships, the construction of the second pair was abandoned. The main modification in design was the abolition of the external keel, and in this the later Zeppelin principles were adopted. This secured a very considerable reduction in structural weight with a corresponding large expansion of the effective capabilities of the ship. It has been seen that the purpose of the keel in No. 9 was to provide a structure sufficiently strong to support all the main vertical bending moments and shearing forces, and that in No. 23 this principle was somewhat different, in that the keel in this ship was primarily intended to support the distributed weights of petrol, water, ballast, etc., between the transverse frames. In this later design, namely, the 23 X class, it was considered that the weights could be concentrated and suspended from the radial wiring of the transverse frames and that the keel, incorporated in the design of the former ships, could be dispensed with. For all practical purposes, apart from the absence of the keel, the 23 X class of airship may be regarded as a slightly varied model of the 23 class. The main dimensions are nearly the same, and the general arrangement of the ship is but little changed. The loss of space owing to the introduction of the internal corridor is compensated by a modification of the shape of the bow, which was redesigned with a deeper curve. The hull structure was also strengthened by utilizing a stronger type of girder wherever the greatest weights occur. In these strengthened transverse frames the girders, while still remaining of the triangular section, familiar in the other ships, are placed the opposite way round, that is, with the apex pointing outwards. The walking way is situated at the base of the hull passing through the gas chambers, which are specially shaped for the purpose. The corridor is formed of a light construction of hollow wooden struts and duralumin arches covered with netting. In all other leading features the design of the 23 class is adhered to; the gasbags are the same, except for the alteration due to the internal corridor, and the system of valves and the various controls are all highly similar. The arrangement of gondolas and the fitting of engines in all ways corresponds to the original arrangement of R 23, with the exception that they were suspended closer to the hull owing to the absence of the external keel. The substitution of the wing car of the 33 class for the original after gondola, carried out in the modifications undergone by the ships of the 23 class, was not adopted in these ships, as the wireless compartment installed in the keel in the former was fitted in the after gondola in the latter. The disposable lift of these ships under standard conditions is 7 1/2 tons, which shows considerable improvement on the ships of the former classes. Summarizing as before, the performances appear as under-- Speed: Full 56 1/2 miles per hour Normal 53 " " " Cruising 45 " " " Endurance: Normal 19 hours = 1,015 miles Cruising 23 1/2 " = 1,050 " The two ships of this class, which were commissioned, must be regarded within certain limits as most satisfactory, and are the most successful of those that appeared and were employed during the war. Escort of convoys and extended anti-submarine patrols were carried out, and certain valuable experiments will be attempted now that peace has arrived. In spite of the grave misgivings of many critics, the structure without the keel has proved amply strong, and no mishap attended this radical departure on the part of the designers. RIGID AIRSHIP No. 31 CLASS The airship known as R 81 was a complete deviation from any rigid airship previously built in this country. In this case the experiment was tried of constructing it in wood in accordance with the practice adopted by the Schutte-Lanz Company in Germany. It must be frankly acknowledged that this experiment resulted in failure. The ship when completed showed great improvement both in shape, speed and lifting capacity over any airship commissioned in this country, and as a whole the workmanship exhibited in her construction was exquisite. Unfortunately, under the conditions to which it was subjected, the hull structure did not prove durable, and to those conditions the failure is attributed. Under different circumstances it may be hoped that the second ship, when completed, will prove more fortunate. In length R 31 was 615 feet, with a diameter of 66 feet, and the capacity was 1 1/2 million cubic feet. In shape the hull was similar to the later types of Zeppelin, having a rounded bow and a long, tapering stern. The longitudinal and transverse frames were composed of girders built up of three-ply wood, the whole structure being braced in the usual manner with wire bracings. It had been found in practice with rigid airships that, if for any reason one gasbag becomes much less inflated than those adjacent to it, there is considerable pressure having the effect of forcing the radial wires of the transverse frames towards the empty bag. The tension resulting in these wires may produce very serious compressive strain in the members of the transverse frames, and to counteract this action an axial wire is led along the axis of the ship and secured to the centre point of the radial wiring. This method, now current practice in rigid airship construction, was introduced for the first time in this ship. As will be seen from the photograph, the control and navigating compartment of the ship is contained in the hull, the cars in each case being merely small engine rooms. These small cars were beautifully made of wood of a shape to afford the least resistance to the air, and in number were five, each housing a single 250 horse-power Rolls Royce engine driving a single fixed propeller. Here we see another decided departure from our previous methods of rigid airship construction, in that for the first time swivelling propellers were abandoned. R 31 when completed carried out her trials, and it was evident that she was much faster than previous ships. The trials were on the whole satisfactory and, except for a few minor accidents to the hull framework and fins, nothing untoward occurred. At a later date the whole ship was through fortuitous circumstances exposed to certain disadvantageous conditions which rendered her incapable of further use. R 33 CLASS September 24th, 1916, is one of the most important days in the history of rigid airship design in this country; on this date the German Zeppelin airship L 33 was damaged by gunfire over London, and being hit in the after gasbags attempted to return to Germany. Owing to lack of buoyancy she was forced to land at Little Wigborough, in Essex, where the crew, having set fire to the ship, gave themselves up. Although practically the entire fabric of the ship was destroyed, the hull structure most fortunately remained to all intents and purposes intact, and was of inestimable value to the design staff of the Admiralty, who measured up the whole ship and made working drawings of every part available. During this year other German rigid airships had been brought down, namely L 15, which was destroyed at the mouth of the Thames in April, but which was of an old type, and from which little useful information was obtained; and also the Army airship L.Z. 85, which was destroyed at Salonica in the month of May. A Schutte-Lanz airship was also brought down at Cuffley, on September 2nd, and afforded certain valuable details. All these ships were, however, becoming out of date; but L 33 was of the latest design, familiarly called the super-Zeppelin, and had only been completed about six weeks before she encountered disaster. In view of the fact that the rigid airships building in this country at this date, with the exception of the wooden Schutte-Lanz ships were all based on pre-war designs of Zeppelin airships, it can be readily understood that this latest capture revolutionized all previous ideas, and to a greater extent than might be imagined, owing to the immense advance, both in design and construction, which had taken place in Germany since 1914. All possible information having been obtained, both from the wreck of the airship itself and from interrogation of the captured crew, approval was obtained, in November of the same year, for two ships of the L 33 design to be built; and in January, 1917, this number was increased to five. It was intended originally that these ships should be an exact facsimile of L 33; but owing to the length of time occupied in construction later information was obtained before they were completed, both from ships of a more modern design, which were subsequently brought down, and also from other sources. Acting on this information, various improvements were embodied in R 33 and R 34, which were in a more advanced state; but in the case of the three other ships the size was increased, and the ships, when completed, will bear resemblance to a later type altogether. As a comment on the slowness of construction before mentioned, the fact that while we in this country were building two ships on two slips, Germany had constructed no fewer than thirty on four slips, certainly affords considerable food for reflection. The two airships of this class having only just reached a state of completion, a detailed description cannot be given without making public much information which must necessarily remain secret for the present. Various descriptions have, however, been given in the daily and weekly Press, but it is not intended in the present edition of this book to attempt to elaborate on anything which has not been already revealed through these channels. It is regrettable that so much that would be of the utmost interest has to be omitted; but the particulars which follow will at any rate give sonic idea of the magnitude of the ship and show that it marks a decided departure from previous experiments and a great advance on any airship before constructed in Great Britain. It is also a matter for regret that these two ships were not completed before the termination of hostilities, as their capabilities would appear to be sufficient to warrant the expectations which have been based on their practical utility as scouting agents for the Grand Fleet. In all its main features the hull structure of R 33 and R 34 follows the design of the wrecked German Zeppelin airship L 33. The hull follows more nearly a true streamline shape than in the previous ships constructed of duralumin, in which a great proportion of the total length was parallel-sided. The Germans adopted this new shape from the Schutte-Lanz design and have not departed from this practice. This consists of a short parallel body with a long rounded bow and a long tapering stem culminating in a point. The overall length of the ship is 643 feet with a diameter of 79 feet and an extreme height of 92 feet. The type of girders in this class has been much altered from those in previous ships. The hull is fitted with an internal triangular keel throughout practically the entire length. This forms the main corridor of the ship, and is fitted with a footway down the centre for its entire length. It contains water ballast and petrol tanks, bomb stowage and crew accommodation and the various control wires, petrol pipes and electric leads are carried along the lower part. Throughout this internal corridor runs a bridge girder, from which the petrol and water ballast tanks are supported. These tanks are so arranged that they can be dropped clear of the ship. Amidships is the cabin space with sufficient room for a crew of twenty-five. Hammocks can be slung from the bridge girder before mentioned. In accordance with the latest Zeppelin practice, monoplane rudders and elevators are fitted to the horizontal and vertical fins. The ship is supported in the air by nineteen gasbags which give a total capacity of approximately two million cubic feet of gas. The gross lift works out at approximately 59 1/2 tons, of which the total fixed weight is 33 tons, giving a disposable lift of 26 1/2 tons. The arrangement of cars is as follows: At the forward end the control car is slung, which contains all navigating instruments and the various controls. Adjoining this is the wireless cabin, which is also fitted for wireless telephony. Immediately aft of this is the forward power car containing one engine, which gives the appearance that the whole is one large car. Amidships are two wing cars each containing a single engine. These are small and just accommodate the engine with sufficient room for mechanics to attend to them. Further aft is another larger car which contains an auxiliary control position and two engines. It will thus be seen that five engines are installed in the ship; these are all of the same type and horse-power, namely, 250 horse-power Sunbeam. R 33 was constructed by Messrs. Armstrong Whitworth Ltd., while her sister ship R 34 was built by Messrs. Beardmore on the Clyde. In the spring of 1918, R 33 and R 34 carried out several flight trials, and though various difficulties were encountered both with the engines and also with the elevator and rudder controls, it was evident that, with these defects remedied, each of these ships would prove to be singularly reliable. On one of these trials made by R 34, exceedingly bad weather was encountered, and the airship passed through several blinding snowstorms; nevertheless the proposed flight of some seventeen hours was completed, and though at times progress was practically nil owing to the extreme force of the wind, the station was reached in safety and the ship landed without any contretemps. This trial run having been accomplished in weather such as would never have been chosen in the earlier days of rigid trial flights, those connected with the airship felt that their confidence in the vessel's capabilities was by no means exaggerated. The lift of the ship warranted a greater supply of petrol being carried than there was accommodation for, and the engines by now had been "tuned up" to a high standard of efficiency. Accordingly it was considered that the ship possessed the necessary qualifications for a transatlantic flight. It was, moreover, the opinion of the leading officers of the airship service that such an enterprise would be of inestimable value to the airship itself, as demonstrating its utility in the future for commercial purposes. Efforts were made to obtain permission for the flight to be attempted, and although at first the naval authorities were disinclined to risk such a valuable ship on what appeared to be an adventure of doubtful outcome, eventually all opposition was overcome and it was agreed that for the purposes of this voyage the ship was to be taken over by the Air Ministry from the Admiralty. Work was started immediately to fit out the ship for a journey of this description. Extra petrol tanks were disposed in the hull structure to enable a greater supply of fuel to be carried, a new and improved type of outer cover was fitted, and by May 29th, R 34 was completed to the satisfaction of the Admiralty and was accepted. On the evening of the same day she left for her station, East Fortune, on the Firth of Forth. This short passage from the Clyde to the Forth was not devoid of incident, as soon after leaving the ground a low-lying fog enveloped the whole country and it was found impossible to land with any degree of safety. It having been resolved not to land until the fog lifted, the airship cruised about the north-east coast of England and even came as far south as York. Returning to Scotland, she found the fog had cleared, and was landed safely, having been in the air for 21 hours. The original intention was that the Atlantic flight should be made at the beginning of June, but the apparent unwillingness of the Germans to sign the Peace Treaty caused the Admiralty to retain the ship for a time and commission her on a war footing. During this period she went for an extended cruise over Denmark, along the north coast of Germany and over the Baltic. This flight was accomplished in 56 hours, during which extremely bad weather conditions were experienced at times. On its conclusion captain and crew of the ship expressed their opinion that the crossing of the Atlantic was with ordinary luck a moral certainty. Peace having been signed, the ship was overhauled once more and made ready for the flight, and the day selected some three weeks before was July 2nd. A selected party of air-service ratings, together with two officers, were sent over to America to make all the necessary arrangements, and the American authorities afforded every conceivable facility to render the flight successful. As there is no shed in America capable of housing a big rigid, there was no alternative but to moor her out in the open, replenish supplies of gas and fuel and make the return journey as quickly as possible. On July 2nd, at 2.38 a.m. (British summer time), R 34 left the ground at East Fortune, carrying a total number of 30 persons. The route followed was a somewhat northerly one, the north coast of Ireland being skirted and a more or less direct course was kept to Newfoundland. From thence the south-east coast of Nova Scotia was followed and the mainland was picked up near Cape Cod. From Cape Cod the airship proceeded to Mineola, the landing place on Long Island. All went well until Newfoundland was reached. Over this island fog was encountered, and later electrical storms became a disturbing element when over Nova Scotia and the Bay of Fundy. The course had to be altered to avoid these storms, and owing to this the petrol began to run short. No anxiety was occasioned until on Saturday, July 5th, a wireless signal was sent at 3.59 p.m. asking for assistance, and destroyers were dispatched immediately to the scene. Later messages were received indicating that the position was very acute, as head winds were being encountered and petrol was running short. The airship, however, struggled on, and though at one time the possibility of landing at Montauk, at the northern end of Long Island, was considered, she managed after a night of considerable anxiety to reach Mineola and land there in safety on July 6th at 9.55 a.m. (British summer time). The total duration of the outward voyage was 108 hours 12 minutes, and during this time some 3,136 sea miles were covered. R 34 remained at Mineola until midnight of July 9th according to American time. During the four days in which she was moored out variable weather was experienced, and in a gale of wind the mooring point was torn out, but fortunately, another trail rope was dropped and made fast, and the airship did not break away. It was intended that the return should be delayed until daylight, in order that spectators in New York should obtain a good view of the airship, but an approaching storm was reported and the preparations were advanced for her immediate departure. During the last half-hour great difficulty was experienced in holding the ship while gassing was completed. At 5.57 a.m. (British summer time) R 34 set out on her return voyage, steering for New York, to fly over the city before heading out into the Atlantic. She was picked up by the searchlights and was distinctly visible to an enormous concourse of spectators. During the early part of the flight a strong following wind was of great assistance, and for a short period an air speed of 83 miles per hour was attained. On the morning of July 11th the foremost of the two engines in the after car broke down and was found to be beyond repair. The remainder of the voyage was accomplished without further incident. On July 12th at noon, a signal was sent telling R 34 to proceed to the airship station at Pulham in Norfolk as the weather was unfavourable for landing in Scotland. On the same day at 8.25 p.m., land was first sighted and the coast line was crossed near Clifden, county Galway, at 9 p.m. On the following morning, July 13th, at 7.57 a.m. (British summer time), the long voyage was completed and R 34 was safely housed in the shed, having been in the air 75 hours 3 minutes. Thus a most remarkable undertaking was brought to a successful conclusion. The weather experienced was by no means abnormally good. This was not an opportunity waited for for weeks and then hurriedly snatched, but on the preordained date the flight was commenced. The airship enthusiast had always declared that the crossing of the Atlantic presented no insuperable difficulty, and when the moment arrived the sceptics found that he was correct. We may therefore assume that this flight is a very important landmark in the history of aerial transport, and has demonstrated that the airship is to be the medium for long-distance travel. We may rest assured that such flights, although creating universal wonder to-day, will of a surety be accepted as everyday occurrences before the world is many years older. CHAPTER VIII THE WORK OF THE AIRSHIP IN THE WORLD WAR The outbreak of war found us, as we have seen, practically without airships of any military value. For this unfortunate circumstance there were many contributory causes. The development of aeronautics generally in this country was behind that of the Continent, and the airship had suffered to a greater extent than either the seaplane or the aeroplane. Our attitude in fact towards the air had not altered so very greatly from that of the man who remarked, on reading in his paper that some pioneer of aviation had met with destruction, "If we had been meant to fly, God would have given us wings." Absurd as this sounds nowadays, it was the opinion of most people in this country, with the exception of a few enthusiasts, until only a few years before we were plunged into war. The year 1909 saw the vindication of the enthusiasts, for in this summer Bleriot crossed the Channel in an aeroplane, and the first passenger-carrying Zeppelin airship was completed. Those who had previously scoffed came to the conclusion that flying was not only possible but an accomplished fact, and the next two years with their great aerial cross-country circuits revealed the vast potentialities of aircraft in assisting in military operations. We, therefore, began to study aeronautics as the science of the future, and aircraft as an adjunct to the sea and land forces of the empire. The airship, unfortunately, suffered for many reasons from the lack of encouragement afforded generally to the development of aeronautics. The airship undoubtedly is expensive, and one airship of size costs more to build than many aeroplanes. In addition, everything connected with the airship is a source of considerable outlay. The shed to house an airship is a most costly undertaking, and takes time and an expenditure of material to erect, and bears no comparison with the cheap hangar which can be run up in a moment to accommodate the aeroplane. The gas to lift the airship is by no means a cheap commodity. If it is to be made on the station where the airship is based, it necessitates the provision of an expensive and elaborate plant. If, on the other hand, it is to be manufactured at a factory, the question of transport comes in, which is a further source of expense with costly hydrogen tubes for its conveyance. Another drawback is the large tract of ground required for an aerodrome, and the big airship needs a large number of highly-trained personnel to handle it. A further point always, raised when the policy of developing the airship was mooted is its vulnerability. It cannot be denied that it presents a large target to artillery or to the aeroplane attacking it, and owing to the highly inflammable nature of hydrogen when mixed with air there can be no escape if the gas containers are pierced by incendiary bullets or shells. Another contributing factor to the slow development of the airship was the lack of private enterprise. Rivalry existed between private firms for aeroplane contracts which consequently produced improvements in design; airships could not be produced in this way owing to the high initial cost, and if the resulting ships ended in failure, as many were bound to do, there would be no return for a large outlay of capital. The only way by which private firms could be encouraged to embark on airship building was by subsidies from the Government, and at this time the prevalent idea of the doubtful value of the airship was too strong for money to be voted for this purpose. To strengthen this argument no demand had either been made from those in command of the Fleet or from commanders of our Armies for airships to act as auxiliaries to our forces. The disasters experienced by all early airships and most particularly by the Zeppelins were always seized upon by those who desired to convince the country what unstable craft they were, and however safe in the air they might be were always liable to be wrecked when landing in anything but fine weather. Those who might have sunk their money in airship building thereupon patted themselves upon the back and rejoiced that they had been so far-seeing as to avoid being engaged upon such a profitless industry. Finally, all in authority were agreed to adopt the policy of letting other countries buy their experience and to profit from it at a later date. Had the war been postponed for another twenty years all might have been well, and we should have reaped the benefit, but most calamitously for ourselves it arrived when we were utterly unprepared, and having, as we repeat, only three airships of any military value. With these three ships, Astra-Torres (No. 3), Parseval (No. 4) and Beta, the Navy did all that was possible. At the very outbreak of war scouting trips were made out into the North Sea beyond the mouth of the Thames by the Astra and Parseval, and both these ships patrolled the Channel during the passage of the Expeditionary Force. The Astra was also employed off the Belgian coast to assist the naval landing party at Ostend, and together with the Parseval assisted in patrolling the Channel during the first winter of the war. The Beta was also sent over to Dunkirk to assist in spotting for artillery fire and locating German batteries on the Belgian coast. Our airships were also employed for aerial inspection of London and other large towns by night to examine the effects of lighting restrictions and obtain information for our anti-aircraft batteries. With the single exception of the S.S. ship, which carried out certain manoeuvres in France in the summer of 1916, our airships were confined to operations over the sea; but if we had possessed ships of greater reliability in the early days of the war, it is conceivable that they would have been of value for certain purposes to the Army. The Germans employed their Zeppelins at the bombardment of Antwerp, Warsaw, Nancy and Libau, and their raids on England are too well remembered to need description. The French also used airships for the observation of troops mobilizing and for the destruction of railway depots. The Italians relied entirely at the beginning of the war on airships, constructed to fly at great heights, for the bombing of Austrian troops and territory, and met with a considerable measure of success. When it was decided, early in 1915, to develop the airship for anti-submarine work difficulties which appeared almost insuperable were encountered at first. To begin with, there were practically no firms in the country capable of airship production. The construction of envelopes was a great problem; as rubber-proofed fabric had been found by experiment to yield the best results for the holding of gas, various waterproofing firms were invited to make envelopes, and by whole-hearted efforts and untiring industry they at last provided very excellent samples. Fins, rudder planes, and cars were also entrusted to firms which had had no previous experience of this class of work, and it is rather curious to reflect that envelopes were produced by the makers of mackintoshes and that cars and planes were constructed by a shop-window furnisher. This was a sure sign that all classes of the community were pulling together for the good of the common cause. Among other difficulties was the shortage of hydrogen tubes, plants, and the silicol for making gas. Sufficient sheds and aerodromes were also lacking, and the airships themselves were completed more quickly than the sheds which were to house them. The lack of airship personnel to meet the expansion of the service presented a further obstacle. To overcome this the system of direct entry into the R.N.A.S. was instituted, which enabled pilots to be enrolled from civil life in addition to the midshipmen who were drafted from the Fleet. The majority of the ratings were recruited from civil life and given instruction in rigging and aero-engines as quickly as possible, while technical officers were nearly all civilians and granted commissions in the R.N.V.R. A tremendous drawback was the absence of rigid airships and the lack of duralumin with which to construct them. Few men were also experienced in airship work at this time, and there was no central airship training establishment as was afterwards instituted. Pilots were instructed as occasion permitted at the various patrol stations, having passed a balloon course and undergone a rudimentary training at various places. To conclude, the greatest of all difficulties was the shortage of money voted for airship development, and this was a disadvantage under which airships laboured even until the conclusion of hostilities. We have seen previously how the other difficulties were surmounted and how our airships were evolved, type by type, and the measure of success which attended them. It is interesting to recall that five years ago we only possessed three ships capable of flying, and that during the war we built upwards of two hundred, of which no fewer than 103 were actually in commission on the date of the signing of the Armistice. The work carried out by our airships during the war falls under three main headings: 1. Operations with the fleet or with various units. 2. Anti-submarine patrol and searching for mines. 3. Escort of shipping and examination duties. With regard to the first heading it is only permissible at present to say very little; certain manoeuvres were carried out in connection with the fleet, but the slow development of our rigid airships prohibited anything on a large scale being attempted. The Germans, on the other hand, made the fullest use of their Zeppelins for scouting purposes with the high seas fleet. Responsible people were guilty of a grave mistake when speaking in public in denouncing the Zeppelin as a useless monster every time one was destroyed in a raid on this country. The main function of the Zeppelin airship was to act as an aerial scout, and it carried out these duties with the utmost efficiency during the war. It is acknowledged that the German fleet owed its escape after the Battle of Jutland to the information received from their airships, while again the Zeppelin was instrumental in effecting the escape of the flotilla which bombarded Scarborough in 1916. Very probably, also, the large airship was responsible for the success which attended the U boats during their attack on the cruisers Nottingham and Falmouth, and also at the Hogue disaster. Various experiments were carried out in towing airships by cruisers, in refuelling while in tow and changing crews, all of which would have borne good fruit had the war lasted longer. An exceedingly interesting experiment was carried out during the closing stages of the war by an airship of the S.S. Zero type. At this period the German submarines were gradually extending their operations at a greater distance from our coasts, and the authorities became concerned at the prospect that the small type of airship would not possess sufficient endurance to carry out patrol over these increased distances. The possibility was considered of carrying a small airship on board a ship which should carry out patrol and return to the ship for refuelling purposes, to replenish gas, and change her crew. To test the feasibility of this idea S.S. Z 57 carried out landing experiments on the deck of H.M.S. Furious, which had been adapted as an aeroplane carrier. S.S. Z 57 came over the deck and dropped her trail rope, which was passed through a block secured to the deck, and was hauled down without difficulty. These experiments were continued while the ship was under weigh and were highly successful. No great difficulty was encountered in making fast the trail rope, and the airship proved quite easy to handle. The car was also lowered into the hangar below the upper deck, the envelope only remaining on the upper level, and everything worked smoothly. If the war had continued there is no doubt that some attempt would have been made to test the practical efficiency of the problem. Anti-submarine patrol was the chief work of the airship during the war, and, like everything else, underwent most striking changes. Submarine hunting probably had more clever brains concentrated upon it than anything else in the war, and the part allotted to the airship in conjunction with the hunting flotillas of surface craft was carefully thought out. In the case of a suspected submarine in a certain spot, all surface and air craft were concentrated by means of wireless signals at the appointed rendezvous. It is in operations of this kind that the airship is so superior to the seaplane or aeroplane, as she can hover over a fixed point for an indefinite period with engines shut off. If the submarine was located from the air, signals were given and depth charges dropped in the position pointed out. Incidents of this kind were of frequent occurrence, and in them the value of the airship was fully recognized. The most monotonous and arduous of the airship's duties was the routine patrol. The ship would leave her shed before dawn and be at the appointed place many miles away from land. She then would carry out patrol, closely scanning the sea all round, and investigating any suspicious object. For hours this might last with nothing seen, and then in the gathering darkness the ship would make her way home often against a rising wind, and in the winter through hail and snow. Bombs were always carried, and on many occasions direct hits were observed on enemy submarines. A sharp look-out was always kept for mines, and many were destroyed, either by gunfire from the airship herself or through the agency of patrol boats in the vicinity. This was the chief work of the S.S. ships, and was brought to a high pitch of perfection by the S.S. Zero. These ships proved so handy that they could circle round an object without ever losing sight of it, and yet could be taken in and out of sheds in weather too bad to handle bigger ships. The hunting of the submarine has been likened to big-game hunting, and certainly no one ever set out to destroy a bigger quarry. It needs the same amount of patience and the same vigilance. Days may pass without the opportunity, and that will only be a fleeting one: the psychological moment must be seized and it will not brook a moment's delay. The eye must be trained to pick up the minutest detail, and must be capable of doing this for hour after hour. For those on submarine patrol in a small ship there is not one second's rest. As is well known, the submarine campaign reached its climax in April, 1917. In that month British and Allied shipping sustained its greatest losses. The value of the airship in combating this menace was now fully recognized, and with the big building programme of Zero airships approved, the housing accommodation again reached an acute stage. Shortage of steel and timber for shed building, and the lack of labour to erect these materials had they been available, rendered other methods necessary. It was resolved to try the experiment of mooring airships in clearings cut into belts of trees or small woods. A suitable site was selected and the trees were felled by service labour. The ships were then taken into the gaps thus formed and were moored by steel wires to the adjacent trees. Screens of brushwood were then built up between the trees, and the whole scheme proved so successful that even in winter, when the trees were stripped of their foliage, airships rode out gales of over 60 miles per hour. The personnel were housed either in tents or billeted in cottages or houses in the neighbourhood, and gas was supplied in tubes as in the earlier days of the stations before the gas plants had been erected. This method having succeeded beyond the most sanguine expectations, every station had one or more of these sub-stations based on it, the airships allocated to them making a periodical visit to the parent station for overhaul as required. Engineering repairs were effected by workshop lorries, provided that extensive work was not required. In this way a large fleet of small airships was maintained around our coasts, leaving the bigger types of ships on the parent stations, and the operations were enabled to be considerably extended. Of course, certain ships were wrecked when gales of unprecedented violence sprung up; but the output of envelopes, planes and cars was by this time so good that a ship could be replaced at a few hours' notice, and the cost compared with building of additional sheds was so small as to be negligible. From the month of April, 1917, the convoy system was introduced, by which all ships on entering the danger zones were collected at an appointed rendezvous and escorted by destroyers and patrolboats. The airship was singularly suitable to assist in these duties. Owing to her power of reducing her speed to whatever was required, she could keep her station ahead or abeam of the convoy as was necessary, and from her altitude was able to exercise an outlook for a far greater distance than was possible from the bridge of a destroyer. She could also sweep the surface ahead of the approaching convoy, and warn it by wireless or by flash-lamp of the presence of submarines or mines. By these timely warnings many vessels were saved. Owing to the position of the stations it was possible for a convoy to be met by airships west of the Scilly Isles and escorted by the airships of the succeeding stations right up the Channel. In a similar manner, the main shipping routes on the east coast and also in the Irish Sea were under constant observation. The mail steamers between England and Ireland and transports between England and France were always escorted whenever flying conditions were possible. For escort duties involving long hours of flying, the Coastal and C Star types were peculiarly suitable, and at a later date the North Sea, which could accompany a convoy for the length of Scotland. Airships have often proved of value in summoning help to torpedoed vessels, and on occasions survivors in open boats have been rescued through the agency of patrolling airships. Examination duties are reckoned among the many obligations of the airship. Suspicious-looking vessels were always carefully scrutinized, and if unable to give a satisfactory answer to signals made, were reported to vessels of the auxiliary patrol for closer examination. Isolated fishing vessels always were kept under close observation, for one of the many ruses of the submarine was to adopt the disguise of a harmless fishing boat with masts and sails. The large transports, conveying American troops who passed through England on their way to France, were always provided with escorting airships whenever possible, and their officers have extolled their merits in most laudatory terms. Our rigid airships also contributed their share in convoy work, although their appearance as active units was delayed owing to slowness in construction. A disturbing feature to the advocate of the large airship, has been the destruction of raiding Zeppelins by heavier-than-air machines, and the Jeremiahs have not lost this opportunity of declaring that for war purposes the huge rigid is now useless and will always be at the complete mercy of the fast scouting aeroplane. There is never any obstacle in this world that cannot be surmounted by some means or other. On the one hand there is helium, a non-inflammable gas which would render airships almost immune to such attacks. On the other hand, one opinion of thought is that the rigid airship in the future will proceed to sea escorted by a squadron of scouting aeroplanes for its defence, in the same way that the capital ship is escorted at sea by destroyers and torpedo boats. This latter idea has been even further developed by those who look into the future, and have conceived the possibility of a gigantic airship carrying its own aeroplanes for its protection. To test the possibility of this innovation, a small aeroplane was attached to one of our rigid airships beneath the keel. Attachments were made to the top of the wings and were carried to the main framework of the hull. The release gear was tested on the ground to preclude the possibility of any accident, and on the day appointed the airship was got ready for flight. While the airship was flying, the pilot of the aeroplane was in his position with his engine just ticking over. The bows of the airship were then inclined upwards and the release gear was put into operation. The pilot afterwards said that he had no notion that anything had been done until he noticed that the airship was some considerable height above him. The machine made a circuit of the aerodrome and landed in perfect safety, while no trouble was experienced in any way in the airship. Whether this satisfactory experiment will have any practical outcome the future alone can say, but this achievement would have been considered, beyond all the possibilities of attainment only a few years ago. Since the Armistice several notable endurance flights were accomplished by ships of the North Sea class, several voyages being made to the coast of Norway, and quite recently a trip was carried out all round the North Sea. The weather has ceased to be the deterrent of the early days. Many will no doubt remember seeing the North Sea airship over London on a day of squalls and snow showers, and R 34 encountered heavy snow storms on the occasion of one of her flight trials, which goes to prove that the airship is scarcely the fair-weather aircraft as maintained by her opponents. Throughout the war our airships flew for approximately 89,000 hours and covered a distance of upwards of two and a quarter million miles. The Germans attempted to win the war by the wholesale sinking of our merchant shipping, bringing supplies and food to these islands, and by torpedoing our transports and ships carrying guns and munitions of war. They were, perhaps, nearer to success than we thought at the time, but we were saved by the defeat of the submarine. In the victory won over the underseas craft the airship certainly played a prominent part and we, who never suffered the pinch of hunger, should gratefully remember those who never lost heart, but in spite of all difficulties and discouragement, designed, built, maintained and flew our fleet of airships. CHAPTER IX THE FUTURE OF AIRSHIPS With the signing of the Armistice on November 11th, 1918, the airship's work in the war was practically completed and peace reigned on the stations which for so many months had been centres of feverish activity. The enemy submarines were withdrawn from our shipping routes and merchant ships could traverse the sea in safety except for the occasional danger of drifting mines. "What is to be the future of the airship?" is the question which is agitating the minds of innumerable people at the present moment. During the war we have built the largest fleet of airships in the world, in non-rigids we have reached a stage in design which is unsurpassed by any country, and in rigid airships we are second only to the Germans, who have declared that, with the signing of the peace terms, their aircraft industry will be destroyed. Such is our position at the present moment, a position almost incredible if we look back to the closing days of the year 1914. Are we now to allow ourselves to drift gradually back to our old policy of supineness and negligence as existed before the war? Surely such a thought is inconceivable; as we have organized our airship production for the purposes of war, so shall we have to redouble our efforts for its development in peace, if we intend to maintain our supremacy in the air. Unless all war is from henceforth to cease, a most improbable supposition when the violence of human nature is considered, aircraft will be in the future almost the most important arm. Owing to its speed, there will not be that period of waiting for the concentration and marching of the armies of the past, but the nation resolved on war will be able to strike its blow, and that a very powerful and terrible one, within a few hours of the rupture of negotiations. Every nation to be prepared to counter such a blow must be possessed of adequate resources, and unless the enormous expense is incurred of maintaining in peace a huge establishment of aircraft and personnel, other methods must be adopted of possessing both of these available for war while employed in peace for other purposes. From the war two new methods of transportation have emerged--the aeroplane and the airship. To the business man neither of these is at the present juncture likely to commend itself on the basis of cost per ton mile. When, however, it is considered that the aeroplane is faster than the express train and the airship's speed is double that of the fastest merchant ship, it will be appreciated that for certain commercial purposes both these mediums for transport have their possibilities. The future may prove that in the time to come both the airship and the aeroplane will become self-supporting, but for the present, if assisted by the Government, a fair return may be given for the capital laid out, and a large fleet of aircraft together with the necessary personnel will always be available for military purposes should the emergency arise. The present war has shown that the merchant service provided a valuable addition both of highly-trained personnel and of vessels readily adapted for war purposes, and it appears that a similar organization can be effected to reinforce our aerial navies in future times of danger. In discussions relative to the commercial possibilities of aircraft, a heated controversy always rages between advocates of the airship and those of the heavier-than-air machine, but into this it is not proposed to plunge the reader of this volume. The aeroplane is eminently adapted for certain purposes, and the greatest bigot in favour of the airship can hardly dispute the claims of this machine to remain predominant for short-distance travel, where high speed is essential and the load to be carried is light. For long distance voyages over the oceans or broken or unpopulated country, where large loads are to be carried, the airship should be found to be the more suitable. The demand for airships for commercial purposes falls under three main headings, which will be considered in some detail. It will be shown to what extent the present types will fill this demand, and how they can be developed in the future to render the proposed undertakings successful. 1. Pleasure. 2. A quick and safe means of transport for passengers. 3. A quick commercial service for delivering goods of reasonable weight from one country to another. 1. Pleasure.--In the past, men have kept mechanically-driven means of transport such as yachts, motor cars, and motor boats for their amusement, and to a limited extent have taken recreation in the air by means of balloons. For short cruises about this country and round the coast a small airship, somewhat similar to the S.S. Zero, would be an ideal craft. In cost it would be considerably less than a small yacht, and as it would only be required in the summer months, it would be inflated and moored out in the open in a park or grounds and the expense of providing a shed need not be incurred. For longer distances, a ship of 150,000 cubic feet capacity, with a covered-in car and driven by two engines, would have an endurance of 25 hours at a cruising speed of 45 miles per hour. With such a ship voyages could easily be made from the south coast to the Riviera or Spain, and mooring out would still be possible under the lee of a small wood or to a buoy on the water. Possibilities also exist for an enterprising firm to start a series of short pleasure trips at various fashionable seaside resorts, and until the novelty had worn off the demand for such excursions will probably be far in excess of the supply. 2. Passenger transport.--In the re-organization of the world after this devastating war the business man's time will be of even more value than it was before. This country is largely bound up with the United States of America in business interests which necessitate continual visits between the two countries. The time occupied by steamer in completing this journey is at present about five days. If this time can be cut down to two and a half days, no doubt a large number of passengers will be only too anxious to avail themselves of this means of travel, providing that it will be accomplished in reasonable safety and comfort. The requirements for this purpose are an aerial liner capable of carrying a hundred passengers with a certain quantity of luggage and sufficient provisions for a voyage which may be extended over the specified time owing to weather conditions. The transatlantic service if successful could then be extended until regular passenger routes are established encircling the globe. 3. Quick commercial service for certain types of goods.--Certain mails and parcels are largely enhanced in value by the rapidity of transport, and here, as in the passenger service outlined above, the airship offers undoubted facilities. As we have said before, it is mainly over long distances that the airship will score, and for long distances on the amount carried the success of the enterprise will be secured. For this purpose the rigid airship will be essential. There are certain instances in which the non-rigid may possibly be profitably utilized, and one such is suggested by a mail service between this country and Scandinavia. A service is feasible between Newcastle and Norway by airships of a capacity of the S.S. Twin type. These ships would carry 700 lb. of mails each trip at about 4d. per ounce, which would reduce the time of delivering letters from about two and a half to three days to twenty-four hours. A commercial airship company is regarded in this country as a new and highly hazardous undertaking, and it seems to be somewhat overlooked that it is not quite the novel idea so many people imagine. Before the war, in the years 1910 to 1914, the Deutsche Luftfahrt Actien Gesellschaft successfully ran a commercial Zeppelin service in which four airships were used, namely, Schwaben, Victoria Luise, Hansa and Sachsan. During this period over 17,000 passengers were carried a total distance of over 100,000 miles without incurring a single fatal accident. Numerous English people made trips in these airships, including Viscount Jellicoe, but the success of the company has apparently been forgotten. We have endeavoured to show that the non-rigid airship has potentialities even for commercial purposes, but there is no doubt whatever that the future of the airship in the commercial world rests entirely with the rigid type, and the airships of this type moreover must be of infinitely greater capacity than those at present in existence, if a return is to be expected for the capital invested in them. General Sykes stated, in the paper which he read before the London Chamber of Commerce, "that for commercial purposes the airship is eminently adapted for long-distance journeys involving non-stop flights. It has this inherent advantage over the aeroplane, that while there appears to be a limit to the range of the aeroplane as at present constructed, there is practically no limit whatever to that of the airship, as this can be overcome by merely increasing the size. It thus appears that for such journeys as crossing the Atlantic, or crossing the Pacific from the west coast of America to Australia or Japan, the airship will be peculiarly suitable." He also remarked that, "it having been conceded that the scope of the airship is long-distance travel, the only type which need be considered for this purpose is the rigid. The rigid airship is still in an embryonic state, but sufficient has already been accomplished in this country, and more particularly in Germany, to show that with increased capacity there is no reason why, within a few years' time, airships should not be built capable of completing the circuit of the globe and of conveying sufficient passengers and merchandise to render such an undertaking a paying proposition." The report of the Civil Aerial Transport Committee also states that, "airships are the most suitable aircraft for the carrying of passengers where safety, comfort and reliability are essential." When we consider the rapid development of the rigid airship since 1914, it should not be insuperable to construct an airship with the capabilities suggested by General Sykes. In 1914, the average endurance of the Zeppelin at cruising speed was under one day and the maximum full speed about 50 miles per hour. In 1918, the German L 70, which is of 2,195,000 cubic feet capacity, the endurance at 45 miles per hour has risen to 7.4 days and the maximum full speed to 77 miles per hour. The "ceiling" has correspondingly increased from 6,000 feet to 23,000 feet. The British R 38 class, at present building, with a capacity of approximately 2 3/4 million cubic feet has an estimated endurance at 45 miles per hour of 211 hours or 8.8 days, which is 34 hours greater than the German L 70 class. It is evident that for a ship of this calibre the crossing of the Atlantic will possess no difficulty, and as an instance of what has already been accomplished in the way of a long-distance flight the exploit of a Zeppelin airship based in Bulgaria during the war is sufficiently remarkable. This airship in the autumn of 1917 left the station at Jamboli to carry twelve tons of ammunition for the relief of a force operating in German East Africa. Having crossed the Mediterranean, she proceeded up the course of the Nile until she had reached the upper waters of this river. Information was then received by wireless of the surrender of the force, and that its commander, Von Lettow, was a fugitive in the bush. She thereupon set out for home and reached her station in safety, having been in the air 96 hours, or four days, without landing. It is therefore patent that in R 33 and R 34 we possess two airships which can cross to America to-morrow as far as actual distance is concerned, but various other conditions are necessary before such voyages can be undertaken with any prospects of commercial success. The distance between England and America must be roughly taken as 3,000 miles. It is not reasonable for airship stations to be situated either in the inaccessible extreme west of Ireland or among the prevailing fogs of Newfoundland. Weather conditions must also be taken into account; head winds may prevail, rendering the forward speed of the ship to be small even with the engines running full out. In calculations it is considered that the following assumptions should be made: 1. At least 75 per cent additional petrol to be carried as would be necessary for the passage in calm air, should unfavourable weather conditions be met. This amount could be reduced to 50 per cent in future airships with a speed of upwards of 80 miles per hour. 2. About a quarter of the total discharge able lift of the ship should be in the form of merchandise or passengers to render the project a reasonable commercial proposition. We will consider the commercial loads that can be carried by the German airship L 70 and our airships R 33 and R 38 under the conditions given above. Two speeds will be taken for the purposes of this comparison: normal full speed, or about 60 miles per hour, and cruising speed of 45 miles per hour. L 70.--At 60 miles per hour a distance of 3,000 miles will be accomplished in 50 hours. Fuel consumption about 13 tons + 9.75 tons (additional for safety) = 22.75 tons. Available lift for fuel and freight = 27.8 tons. Fuel carried = 22.75 " ------------ Balance for freight = 5 " about. ----------- At 45 miles per hour, distance will be accomplished in 66.6 hours. Fuel consumption about 10 tons + 7.5 tons additional = 17.5 tons. Available lift = 27.8 tons Fuel carried = 17.5 " ------------ Balance for freight = 10 " about. ------------ R. 33.--At 60 miles per hour. Fuel consumption 14.25 tons + 10.68 tons additional = 24.93 tons. Lift available for fuel and freight = 21.5 tons. Fuel carried = 24.93 " ------------ Minus balance = 3. 43 " ------------ At 45 miles per hour. Fuel consumption 9.66 tons + 7.23 tons (17 tons approx.) Lift available for fuel and freight = 21.5 tons. Fuel carried = 17 " ------------ Balance for freight = 4.5 " ------------ R. 38.-Estimated only. At 60 miles per hour. Fuel consumption 20 tons + 15 tons additional = 35 tons. Lift available for fuel and freight = 42 tons. Fuel carried = 35 " ------------ Balance for freight = 7 " ------------ At 45 miles per hour. Fuel consumption 12 tons + 9 tons additional = 21 tons. Lift available for fuel and freight = 42 " Fuel carried = 21 " ------------ Balance for freight = 21 " ------------ It will thus be seen that at the faster speed small commercial loads can be carried by L 70 and R 38 and not at all in the case of R 33, that is assuming, of course, that the extra fuel is carried, of which 75 per cent of the total does not appear at all excessive in view of the weather continually experienced over the Atlantic. At the cruising speed the loads naturally increase but still, in L 70, and more particularly in R 33, they are too small to be considered commercially. In R 38, however, the load that can be carried at cruising speed is sufficient to become a commercial proposition. From this short statement it is evident that, by a comparatively small increase in volume, the lifting capacity of an airship is enormously increased, and it is in this subject that the airship possesses such undoubted advantage over the aeroplane. In the heavier-than-air machine there is no automatic improvement in efficiency resulting from greater dimensions. In the airship, however, this automatic improvement takes place in a very marked degree; for example, an airship of 10,000,000 cubic feet capacity has five times the lift of the present 2,000,000 cubic feet capacity rigid, but the length of the former is only 1.7 times greater, and therefore the weight of the structure only five times greater (1.7); that is, the weight of the structure is directly proportional to the total lift. Having seen that the total lift varies as the cube of the linear dimensions while air resistance, B.H.P.--other things being equal--vary as the square of the linear dimensions, it follows that the ratio "weight of machinery/total lift" decreases automatically. In comparing the different methods of transport for efficiency, the resistance or thrust required is compared as a percentage of the total weight. The result obtained is known as the "co-efficient of tractive resistance." Experiments have shown that as the size of the airship increases, the co-efficient of tractive resistance decreases to a marked extent; with a proportionate increase in horse-power it is proportionally more economical for a 10,000,000 cubic feet capacity rigid to fly at 80 miles per hour than for a 2,000,000 cubic feet capacity to fly at 60 miles per hour. As the ratio "weight structure/total lift" is in airships fairly constant, it follows that the ratio "disposable lift/total lift" increases with the dimensions. It is therefore obvious that increased benefits are obtained by building airships of a larger size, and that the bigger the ship the greater will be its efficiency, providing, of course, that it is kept within such limits that it can be handled on the ground and manoeuvred in the air. The proportion of the useful lift in a large rigid, that is the lift available for fuel, crew, passengers, and merchandise, is well over 50 per cent when compared with the gross lift. When the accompanying table is studied it will be seen that with airships of large capacity the available lift will be such that considerable weights of merchandise or passengers can be carried. Capacity in Gross Lift Length Diameter cubic feet in tons in feet in feet 2,000,000 60.7 643 79 3,000,000 91.1 736 90.4 4,000,000 121.4 810 99.5 5,000,000 151.8 872 107.2 6,000,000 182.2 927 113.9 7,000,000 212.5 976 119.9 8,000,000 242.8 1,021 125.5 9,000,000 273.3 1,061 130.4 10,000,000 303.6 1,100 135.1 In airships of their present capacity, in order to obtain the greatest amount of lift possible, lightness of construction has been of paramount importance. With this object in view duralumin has been used, and complicated girders built up to obtain strength without increase of weight. In a large ship with a considerable gain in lift, steel will probably be employed with a simpler form of girder work. In that way cheapness of construction will be effected together with increased rapidity of output, and in addition the strength of the whole structure should be increased. The rigid airship of 10,000,000 cubic feet capacity will have a disposable lift of over 200 tons available for fuel, crew, passengers, and merchandise in such proportions as are desired. The endurance of such a ship at a cruising speed of 45 miles per hour will be in the neighbourhood of three weeks, with a maximum speed of 70 to 80 miles per hour, and a "ceiling" of some 30,000 feet can be reached. This will give a range of over 20,000 miles, or very nearly a complete circuit of the globe. For commercial purposes the possibilities of such a craft are enormous, and the uses to which it could be put are manifestly of great importance. Urgent mails and passengers could be transported from England to America in under half the time at present taken by the steamship routes, and any city in the world could be reached from London in a fortnight. In the event of war in the future, which may be waged with a nation situated at a greater distance from this country than was Germany, aircraft Of long endurance will be necessary both for scouting in conjunction with our fleets and convoy duties. The British Empire is widely scattered, and large tracts of ocean lie between the various colonies, all of which will require protection for the safe-guarding of our merchant shipping. The provision of a force of these large airships will greatly add to the security of our out-lying dominions. We have now reached a point where it is incumbent on us to face certain difficulties which beset the airship of large dimensions, and which are always magnified by its detractors. Firstly, there is the expense of sheds in which to house it; secondly, the large number of trained personnel to assist in landing and handling it when on the ground; thirdly, the risks attendant on the weather--for the airship is still considered the general public as a fair-weather craft; and fourthly, though this is principally in connection with its efficiency for military purposes, its vulnerability. We will deal with the four difficulties enumerated under these headings seriatim, and endeavour to show to what extent they may be surmounted if not entirely removed. The solution of the first two problems may be summed up in two words: "mooring out"; on the success of this it is considered that the whole future of airships for commercial purposes rests. It will be essential that in every country which the airship visits on its voyages, one large central station is established for housing and repairs. The position of such a station is dependent on good weather conditions and the best railway facilities possible. In all respects this station will be comparable to a dry dock for surface vessels. The airship will be taken into the shed for overhaul of hull structure, renewing of gasbags or outer cover, and in short to undergo a periodical refit. The cost of a shed capable of housing two rigid airships, even at the present time, should not greatly exceed L500,000. This sum, though considerable, is but a small item compared with the cost of constructing docks to accommodate the Atlantic liner, and when once completed the cost of maintenance is small when weighed against the amount annually expended in dredging and making good the wear and tear of a dock. Apart from these occasional visits to a shed, the airship, in the ordinary way at the end of a voyage, will pick up its moorings as does the big steamer, and land its passengers and cargo, at the same time replenishing its supplies of fuel, gas, provisions, etc., while minor repairs to the machinery can be carried out as she rides in the air. A completely satisfactory solution of the mooring problem for the rigid airship has yet to reach its consummation. We saw in the previous chapter how, in the case of small non-rigids, they were sheltered in berths cut into woods or belts of trees, but for the rigid airship something more secure and less at the mercy of the elements is required. At the present moment three systems of mooring are in an experimental stage: one, known as "the single-wire system," is now practically acknowledged to fall short of perfection; the second, "the three-wire system," and the third, "mooring to a mast," both have their champions, but it is probable that the last will be the one finally chosen, and when thoroughly tried out with its imperfections eliminated will satisfy the most exacting critics. The single-wire system is at the same time the simplest and most obvious method which suggests itself, and means that the ship is secured by a wire cable attached to a suitable point in the ship and led to some fixed point on the ground. It has been found that an airship secured in this way requires constant attention, and that steering is always necessary to render her steady in the air. Considerable improvement is obtained if a dragging weight is added to the wire, as it tends to check to a considerable extent lateral motion of the bow of the ship. The three-wire system is an adaptation and an improvement on the one previously mentioned. In this case the mooring point of the ship is attached to three long wire cables, which, when raised in the air, form a pyramid to the head of which the ship is attached. These wires are led to bollards which form in plan an equilateral triangle. The lift of the ship raises these wires off the ground, and if the ship is trimmed up by the bows she will be found to resist the action of the wind. A rigid airship moored out by this method remained in the open for a considerable time and rendered the future of this experiment most hopeful. It was resolved to continue these experiments by adding a subsidiary system of wires with running blocks, the whole wiring to form a polygon revolving round a fixed centre. The disadvantages of this method appear to be rather serious. It seems that great difficulty will always be found in picking up these moorings in a high wind, and though this also applies to the method with the mast, the initial obstacles do not appear to be so great. A powerful engine driving a winch will be necessary to raise these heavy wires from the ground, although of course the lift of the airship will assist in this. Secondly, the lowering of passengers and cargo will not be easy as the ship will not be rigidly secured. This, however, can probably be managed when experiments have reached a further stage, and at present the system may be said to present distinct possibilities. The third system, that of mooring to a mast, possesses several features peculiar to itself, and not embraced by the other two, which should secure it prolonged investigations. The system is by no means new and has been tried from time to time for several years, but since the question of mooring in the open has been so ventilated and is now considered of such vital importance, these experiments have been continued, and in less spasmodic fashion than in the past. In a trial with a small non-rigid airship some months ago a signal success was achieved. The ship remained attached to a mast in open country with no protection whatsoever for six weeks in two of the worst months of the year. During this period two men only were required to look after the ship, which experienced gales in which the force of the wind rose to 52 miles per hour, and not the slightest damage was sustained. Two or three methods of attaching the airship to the mast have been proposed, but the one which appears to be most practical is to attach the extreme bow point of the ship to some form of cap, in which the nose of the ship will fit, and will revolve round the top of the mast in accordance with the direction of the wind. For large airships, employed as passenger and commerce carriers, we can imagine the mast advanced a stage further, and transformed into a tower with a revolving head. Incorporated in this tower will be a lift for passengers and luggage, pipes also will be led to the summit through which both gas and water can be pumped into the ship. With the airship rigidly held at the head of such a structure all the difficulties of changing crews, embarking and disembarking passengers, shipping and discharging cargo and also refuelling, vanish at once. Assuming the mooring problem solved with success, and we feel correct in this assumption, the first two of our difficulties automatically disappear. Sheds will only be necessary as repair depots and will not be extensively required, all intermediate stopping places being provided with masts and necessary arrangements for taking in gas, etc. At these intermediate stations the number of men employed will be comparatively speaking few. At the depots or repair stations the number must, of course, be considerably increased, but the provision of an enormous handling party will not be necessary. At present large numbers of men are only required to take a large airship in or out of a shed when the wind is blowing in a direction across the shed; when these conditions prevail the airship will, unless compelled by accident or other unforeseen circumstances, remain moored out in the open until the direction of the wind has changed. Mechanical traction will also help effectually in handling airships on the ground, and the difficulty of taking them in and out of sheds has always been unduly magnified. The provision of track rails and travellers to which the guys of the ship can be attached, as is the practice in Germany, will tend to eliminate the source of trouble. We must now consider the effect that weather will have on the big airship. In the past it has been a great handicap owing to the short hours of endurance, with the resulting probability of the ship having to land before the wind dropped and being wrecked in consequence. Bad weather will not endanger the big airship in flight, and its endurance will be such that, should it encounter bad weather, it will be able to wait for a lull to land. Meteorological forecasts have now reached a high state of efficiency, and it should be possible for ample warnings to be received of depressions to be met with during a voyage, and these will be avoided by the airship flying round them. In the northern hemisphere, depressions generally travel from west to east and invariably rotate in a counter-clockwise direction with the wind on the south side blowing from the west and on the north side blowing from the east. Going west, the airship would fly to the north of a depression to take advantage of the wind circulating round the edge, and going east the southern course would be taken. Lastly, the vulnerability of the airship must be taken into account. Hydrogen is, as everyone knows, most highly inflammable when mixed with air. The public still feels uncomfortable misgivings at the close proximity of an immense volume of gas to a number of running engines. It may be said that the danger of disaster due to the gas catching fire is for peace flying to all intents and purposes negligible. At the risk of being thought hackneyed we must point out a fact which has appeared in every discussion of the kind, namely, that British airships flew during the war some 21 million miles, and there is only one case of an airship catching fire in the air. This was during a trial flight in a purely experimental ship, and the cause which was afterwards discovered has been completely eliminated. For airships employed for military purposes this danger, due to the use of incendiary bullets, rockets and various other munitions evolved for their destruction, still exists. Owing to its ceiling, rate of climb and speed, which we take to be from 70 to 80 miles per hour in the airship of the future, the airship may be regarded as comparatively safe against attack from the ordinary type of seaplane. The chief danger to be apprehended is attack from small scouting seaplanes, possessing great speed and the power to climb to a great height, or from aeroplanes launched from the decks of ships. If, however, the airship is fitted to carry several small scout aeroplanes of high efficiency in the manner described in the previous chapter, it will probably be able to defend itself sufficiently to enable it to climb to a great height and thus make good its escape. The airship, moreover, will be more or less immune from such dangers if the non-inflamable gas, known as "C" gas, becomes sufficiently cheap to be used for inflating airships. In the past the expense of this gas has rendered its use absolutely prohibitive, but it is believed that it can be produced in the United States for such a figure as will make it compare favourably with hydrogen. The navigation of an airship during these long voyages proposed will present no difficulty whatever. The airship, as opposed to the aeroplane, is reasonably steady in the air and the ordinary naval instruments can be used. In addition, "directional" wireless telegraphy will prove of immense assistance. The method at present in use is to call up simultaneously two land stations which, knowing their own distance apart, and reading the direction of the call, plot a triangle on a chart which fixes the position of the airship. This position is then transmitted by wireless to the airship. In the future the airship itself will carry its own directional apparatus, with which it will be able to judge the direction of a call received from a single land station and plot its own position on a chart. We have so far confined our attention to the utilization of airships for transport of passengers, mails and goods, but there appear to be other fields of activity which can be exploited in times of peace. The photographic work carried out by aeroplanes during the war on the western front and in Syria and Mesopotamia has shown the value of aerial photography for map making and preliminary surveys of virgin country. Photography of broken country and vast tracks of forest can be much more easily undertaken from an airship than an aeroplane, on account of its power to hover for prolonged periods over any given area and its greater powers of endurance. For exploring the unmapped regions of the Amazon or the upper reaches of the Chinese rivers the airship offers unbounded facilities. Another scope suggested by the above is searching for pearl-oyster beds, sunken treasure, and assisting in salvage operations. Owing to the clearness of the water in tropical regions, objects can be located at a great depth when viewed from the air, and it is imagined that an airship will be of great assistance in searching for likely places. Sponges and coral are also obtained by diving, and here the airship's co-operation will be of value. Small ships such as the S.S. Zero would be ideal craft for these and similar operations. The mine patrol, as maintained by airships during the war, encourages the opinion that a systematic search for icebergs in the northern Atlantic might be carried out by airships during certain months of the year. As is well known, icebergs are a source of great danger to shipping in these waters during the late spring and summer; if the situation becomes bad the main shipping routes are altered and a southerly course is taken which adds considerably to the length of the voyage. The proposal put forward is that during these months as continuous a patrol as possible should be carried out over these waters. The airship employed could be based in Newfoundland and the method of working would be very similar to anti-submarine patrol. Fixes could be obtained from D.F. stations and warnings issued by wireless telegraphy. Ice is chiefly found within five hundred miles of the coast of Newfoundland, so that this work would come within the scope of the N.S. airship. The knowledge that reliable information concerning the presence of ice will always be to hand would prove of inestimable value to the captains of Atlantic liners, and would also relieve the shipping companies and the public of great anxiety. There are possibly many other uses to which airships can be put such as the policing of wide stretches of desert country as in Arabia and the Soudan. The merits of all of these will doubtless be considered in due course and there for the present we must leave them. Finally, a few words must be written regarding the means to be adopted in introducing the airship into the realms of commerce. As we said at the beginning of the chapter it is not likely that the formation of a company to exploit airships only will at the present moment appeal to business men. Airships are very costly and are still in their infancy, which means that the premiums demanded for their insurance must of necessity be enormous. One suggestion is to place a reasonable scheme before the great shipping companies in case they will care to find the necessary capital and form subsidiary companies. Another suggestion is that the Government should make arrangements to subsidize commercial airships. The subsidy might take the form of insuring them. If the burden of insurance is taken off their shoulders, it is considered feasible to promote companies which will give an adequate return for capital invested. The Government could also give a financial guarantee if mails are carried, in the same manner as is done by shipping companies. In return for this the Government could at the outbreak of hostilities commandeer all or any of the airships for war purposes and so save the number to be kept in commission. By this means the Government will have a large number of highly-trained and efficient personnel to call upon when the emergency arises, in the same way as the fleet can call upon the R.N.R. This system appears to be the best in every respect, and it cannot be denied that in the long run it would be the most economical for the country. The airship has now arrived at the parting of the ways, and at this point we must leave it. The flying in war has been concluded, the flying in peace has not yet commenced. It seems a far cry to the dark days of 1914, when we only possessed two airships of utility, the one manufactured in France, the other in Germany, while to-day we have built the mighty airship which can fly to America and back. We are now at the dawn of a new period of reconstruction and progress, and during this period many wonderful things will happen. Not the least of these will be the development of the airship. 
5883	----	This eBook was supplied by John B. Hare and Sacred-Texts.com. The Flying Saucers Are Real by Donald Keyhoe Preface from Sacred-Text.com This was one of the first books published about the UFO phenomena. We are fortunate that it ended up in the public domain. It is a template for much of what would follow: the paranoia, the government disinformation, the inescapable conclusion that the saucers are not of this earth. Keyhoe, with his spare, matter of fact writing style, which also conveys a profound sense of wonder, has to be the prototype for the deadpan Fox Mulder of the X-Files. On one hand we can see the birth of a key modern mythology. On the other, there is a body of almost naive evidence in this text unpolluted by that very mythology. The case studies are real. The witnesses were highly reliable. These cases are still unexplained. THE FLYING SAUCERS ARE REAL by Donald Keyhoe New York To Helen, with love Donald E. Keyhoe, who relates here his investigation of the flying saucers, writes with twenty-five years of experience in observing aeronautical developments. He is a graduate of the U.S. Naval Academy at Annapolis. He flew in active service with the Marine Corps, managed the tour of the historic plane in which Bennett and Byrd made their North Pole flight, was aide to Charles Lindbergh after the famous Paris flight, and was chief of information for the Aeronautics Branch, Department of Commerce. Author's Note ON APRIL 27, 1949, the U.S. Air Force stated: "The mere existence of some yet unidentified flying objects necessitates a constant vigilance on the part of Project 'Saucer' personnel, and on the part of the civilian population. "Answers have been--and will be--drawn from such factors as guided missile research activity, balloons, astronomical phenomena. . . . But there are still question marks. "Possibilities that the saucers are foreign aircraft have also been considered. . . . But observations based on nuclear power plant research in this country label as 'highly improbable' the existence on Earth of engines small enough to have Powered the saucers. "Intelligent life on Mars . . . is not impossible but is completely unproven. The possibility of intelligent life on the Planet Venus is not considered completely unreasonable by astronomers. "The saucers are not jokes. Neither are they cause for alarm." [1] On December 27, 1949, the Air Force denied the existence of flying saucers.[2] On December 30, 1949, the Air Force revealed part of a secret Project "Saucer" report to members of the press at Washington. The official report stated: "It will never be possible to say with certainty that any individual did not see a space ship, an enemy missile, or some other object." Discussing the motives of possible visitors from space, the report also stated: "Such a civilization might observe that on Earth we now have atomic bombs and are fast developing rockets. In view of the past history of mankind, they should be [1. Project "Saucer" Preliminary Study of Flying Saucers. 2. Air Force Press Release 629-49.' {p. 6} alarmed. We should therefore expect at this time above all to behold such visitations." (In its April 22 report, Project "Saucer" stated that space travel outside the solar system is almost a certainty.) On February 22, 1950, the Air Force again denied the existence of flying saucers. On this same date, two saucers reported above Key West Naval Air Station were tracked by radar; they were described as maneuvering at high speed fifty miles above the earth. The Air Force refused to comment. On March 9, 1950, a large metallic disk was pursued by F-51 and jet fighters and observed by scores of Air Force officers at Wright Field, Ohio. On March 18, an Air Force spokesman again denied that saucers exist and specifically stated that they were not American guided missiles or space-exploration devices. I have carefully examined all Air Force saucer reports made in the last three years. For the past year, I have taken part in a special investigation of the flying-saucer riddle. I believe that the Air Force statements, contradictory as they appear, are part of an intricate program to prepare America--and the world--for the secret of the disks. {p. 7} CHAPTER I IT WAS A strange assignment. I picked up the telegram from my desk and read it a third time. NEW YORK, N. Y., MAY 9, 1949 HAVE BEEN INVESTIGATING FLYING SAUCER MYSTERY. FIRST TIP HINTED GIGANTIC HOAX TO COVER UP OFFICIAL SECRET. BELIEVE IT MAY HAVE BEEN PLANTED TO HIDE REAL ANSWER. LOOKS LIKE TERRIFIC STORY. CAN YOU TAKE OVER WASHINGTON END? KEN W. PURDY, EDITOR, TRUE MAGAZINE I glanced out at the Potomac, recalling the first saucer story. As a pilot, I'd been skeptical of flying disks. Then reports had begun to pour in from Air Force and airline pilots. Apparently alarmed, the Air Force had ordered fighters to pursue the fast-flying saucers. In one mysterious chase, a pilot had been killed, and his death was unexplained. That had been seventeen months ago. Since then, the whole flying-saucer riddle had been hidden behind a curtain of Air Force secrecy. And now, an assignment from True magazine on flying saucers. Twenty-four hours later, I was in Ken Purdy's office. "I've had men on this for two months," he told me. "I might as well warn you, it's a tough story to crack." "You think it's a Russian missile?" I asked him. "Or an Air Force secret?" "We've had several answers. None of them stacks up. But I'm positive one was deliberately planted when they found we were checking." He told me the whole story of the work that had been done by the staff of True and of the reports sent in by competent writers. The deeper he delved into the mystery, the tougher the assignment got. The more I learned about flying saucers, the less I knew. "There's one angle I want rechecked," Purdy said. "You've heard of the Mantell case?" {p. 8} I nodded. "O.K. Try to get the details of Mantell's radio report to Godman Tower. Before he was killed, he described the thing he was chasing--we know that much. Project 'Saucer' gave out a hint, but they've never released the transcript. Here's another lead. See if you can find anything about a secret picture, taken at Harmon Field, Newfoundland--it was around July 1947. I'll send you other ideas as I get them." Before I left, Purdy wished me hick and told me that he would work in closest harmony with me. "But watch out for fake tips," he said. "You'll probably run into some people at the Pentagon who'll talk to you 'off the record.' That handcuffs a writer. Look out they don't lead you into a blind alley. Even the Air Force statements and the Project 'Saucer' report contradict each other." For six months, I worked with other investigators to solve the mystery of the disks. We checked a hundred sighting reports, frequently crossing the trail of Project "Saucer" teams and F.B.I. agents. Old records gave fantastic leads. So did Air Force plans for exploring space. Rocket experts, astronomers, Air Force officials and pilot gave us clues pointing to a startling solution. Many intelligent persons--including scientists--believe that the saucers contain spies from another planet. When this first phase was ended, we were faced with a hard decision. We had uncovered important facts, We knew the saucers were real. If it was handled carefully, we believed the story would be in line with a secret Air Force policy. It was finally decided to publish certain alternate conclusions. The Air Force was informed of True's intentions; no attempt was made to block publication. In the January 1950 issue of True, I reported that we had reached the following conclusions: 1 The earth has been observed periodically by visitors from another planet. 2. This observation has increased markedly in the past two years. "The only other possible explanation," I wrote, "is that, {p. 9} the saucers are extremely high-speed, long-range devices developed here on earth. Such an advance (which the Air Force has denied) would require an almost incredible leap in technical progress even for American scientists and designers." Nation-wide press and radio comment followed the appearance of the article. This publicity was obviously greater than the Air Force had expected. Within twenty-four hours the Pentagon was deluged with telegrams, letters, and long-distance calls. Apparently fearing a panic, the Air Force hastily stated that flying-saucer reports--even those made by its own pilots and high-ranking officers--were mistakes or were caused by hysteria.[1] But three days later, when it was plain that many Americans calmly accepted True's disclosures, the Air Force released a secret project "Saucer" file containing this significant statement: "It will never be possible to say with certainty that any individual did not see a space ship, an enemy missile or other object." In this same document there appears a confidential analysis of Air intelligence reports.[2] It is this summary that contains the official suggestion Of. space visitors' motives. After stating that such a civilization would obviously be far ahead of our own, the report adds: "Since the acts of mankind most easily observed from a distance are A-bomb explosions, we should expect some relation to obtain between the time of the A-bomb explosions, the time at which the space ships are seen, and the time required for such ships to arrive from and return to home base." (In a previous report, which alternately warned and reassured the public, the Air Force stated that space travel outside the solar system is almost a certainty.[3]) Since 1949 there has been a steady increase in saucer sightings. Most of them have been authentic reports, which Air Force denials cannot disprove. In January, mystery [1. Air Force press release 629-49, December 27, 1949. 2. Air Force Project "Saucer" December 30, 1949. 3. Air Force report M-26-49, Preliminary Studies on Flying saucers, April 27, 1949.] {p. 10} disks were reported over Kentucky, Indiana, Texas, Pennsylvania, and several other states. On the Seattle Anchorage route, an air freighter was paced for five minutes by a night-flying saucer. When the pilots tried to close in, the strange craft zoomed at terrific speed. Later, the airline head reported that Intelligence officers had quizzed the pilots for hours. "From their questions," he said, "I could tell they had a good idea of what the saucers are. One officer admitted they did, but he wouldn't say any more." Another peculiar incident occurred at Tucson, Arizona, on February 1. Just at dusk, a weird, fiery object raced westward over the city, astonishing hundreds in the streets below. The Tucson Daily Citizen ran the story next day with a double-banner headline: FLYING SAUCER OVER TUCSON? B-29 FAILS TO CATCH OBJECT Flying saucer? Secret experimental plane? Or perhaps a scout craft from Mars? Certainly the strange aircraft that blazed a smoke trail over Tucson at dusk last night defies logical explanation. It was as mystifying to experienced pilots as to groundlings who have trouble in identifying conventional planes. Cannonballing through the sky, some 30,000 feet aloft, was a fiery object shooting westward so fast it was impossible to gain any clear impression of its shape or size. . . . At what must have been top speed the object spewed out light colored smoke, but almost directly over Tucson it appeared to hover for a few seconds. The smoke puffed out an angry black and then be came lighter as the strange missile appeared to gain speed" The radio operator in the Davis-Monthan air force base control tower contacted First Lt. Roy L. Jones, taking off for a cross-country flight in a B-29, and asked him to investigate. Jones revved up his swift aerial tanker and still the unknown aircraft steadily pulled away toward California. Dr. Edwin F. Carpenter, head of the University of {p. 11} Arizona department of astronomy, said he was certain that the object was not a meteor or other natural phenomenon. . . . Switchboards Swamped Switchboards at the Pima county sheriff's office and Tucson police station were jammed with inquiries. Hundreds saw the object. Tom Bailey, 1411 E. 10th Street, thought it was a large airplane on fire. [A later check showed no planes missing.] He said it wavered from left to right as it passed over the mountains. Bailey also noticed that the craft appeared to slow perceptibly over Tucson. He said the smoke apparently came out in a thin, almost invisible stream, gaining substance within a few seconds. This incident had an odd sequel the following day. Its significance was not lost on the Daily Citizen. It ran another front-page story, headlined: WHAT DO YOU MEAN ONLY VAPOR TRAIL? As though to prove itself blameless for tilting hundreds of Tucson heads skyward, the U.S. Air Force yesterday afternoon spent hours etching vapor trails through the skies over the city. The demonstration proved conclusively to the satisfaction of most that the strange path of dark smoke blazed across the evening sky at dusk Wednesday was no vapor trail and did not emanate from any conventional airplane. The Wednesday night spectacle was entirely dissimilar. Then, heavy smoke boiled and swirled in a broad, dark ribbon fanning out at least a mile in width and stretching across the sky in a straight line. Since there was no proof as to what caused the strange predark manifestation, and because even expert witnesses were unable to explain the appearance, the matter remains a subject for interesting speculation. There is strong evidence that this story was deliberately kept off the press wires. The Associated Press and other wire services in Washington had no report. Requests for details by Frank Edwards, Mutual newscaster, and other {p. 12} radio commentators ran into a blank wall. At the Pentagon I was told that the Air Force had no knowledge of the sighting or the vapor-trail maneuvers. On February 22 two similar glowing objects were seen above Boca Chica Naval Air Station at Key West. A plane sent tip to investigate was hopelessly outdistanced; it was obvious the things were at a great height. Back at the station, radarmen tracked the objects as they hovered for a moment above Key West. They were found to be at least fifty miles above the earth. After a few seconds, they accelerated at high speed and streaked out of sight. On the following day Commander Augusto Orrego, a Chilean naval officer, reported that saucers had flown above his antarctic base. "During the bright antarctic night," be said, "we saw flying saucers, one above the other, turning at tremendous speeds. We have photographs to prove what we saw." Early in March, Ken Purdy phoned the latest development in the investigation. He had just received a tip predicting a flurry of saucer publicity during March. It had come from an important source in Washington. "You know what it probably means," he said. "The same thing we talked about last month. But why were we tipped off in advance?" "It's one more piece in the pattern," I said. "If the tip's on the level, then they're stepping up the program." Within three days, reports began to pour in--from Peru, Cuba, Mexico, Turkey, and other parts of the world. Then on March 9 a gleaming metallic disk was sighted over Dayton, Ohio. Observers at Vandalia Airport phoned Wright-Patterson Field. Scores of Air Force pilots and groundmen watched the disk, as fighters raced up in pursuit. The mysterious object streaked vertically skyward, hovered for a while miles above the earth, and then disappeared. A secret report was rushed to the Civil Aeronautics Authority in Washington, then turned over to Air Force Intelligence. Soon after this Dr. Craig Hunter, director of a medical supply firm, reported a huge elliptical saucer flying at a low altitude in Pennsylvania. He described it as metallic, with a slotted outer rim and a rotating ring just inside. {p. 13} On top of this sighting, thousands of people at Farmington, New Mexico, watched a large formation of disks pass high above the city. Throughout all these reports, the Air Force refused to admit the existence of flying saucers. On March 18 it flatly denied they were Air Force secret missiles or space-exploration devices. Three days later, a Chicago and Southern airliner crew saw a fast-flying disk near Stuttgart, Arkansas. The circular craft, blinking a strange blue-white light, pulled up in an arc at terrific speed. The two pilots said they glimpsed lighted ports on the lower side as the saucer zoomed above them. The lights had a soft fluorescence, unlike anything they had seen. There was one peculiar angle in the Arkansas incident. There was no apparent attempt to muzzle the two pilots, as in earlier airline cases. Instead, a United Press interview was quickly arranged, for nation-wide publication. In this wire story Captain Jack Adams and First Officer G. W. Anderson made two statements: "We firmly believe that the flying saucer we saw over Arkansas was a secret experimental type aircraft--not a visitor from outer space. . . "We know the Air Force has denied there is anything to this flying-saucer business, but we're both experienced pilots and we're not easily fooled." The day after this story appeared, I was discussing it with an airline official in Washington. "That's an odd thing," he said. "The Air Force could have persuaded those pilots--or the line president--to hush the thing up. It looks as if they wanted that story broadcast." "You mean the whole thing was planted?" "I won't say that, though it could have been. Probably they did see something. But they might have been told what to say about it." "Any idea why?" He looked at me sharply. "You and Purdy probably know the answer. At a guess, I'd say it might have been planned to offset that Navy commander's report--the one on the White Sands sightings." {p. 14} The White Sands case had puzzled many skeptics, because the Pentagon had cleared the published report. The author, Commander R. B. McLaughlin, was a regular Navy officer. As a Navy rocket expert, he had been stationed at the White Sands Rocket Proving Ground in New Mexico. In his published article he described three disk sightings at White Sands. One of the disks, a huge elliptical craft, was tracked by scientists with precision instruments at five miles per second. That's 18,000 miles per hour. It was found to be flying fifty-six miles above the earth. Two other disks, smaller types, were watched from five observation posts on hills at the proving ground. Circling at incredible speed, the two disks paced an Army high-altitude rocket that had just been launched, then speeded up and swiftly outclimbed the projectile. Commander McLaughlin's report, giving dates and factual details, was cleared by the Department of Defense. So was a later nation-wide broadcast. Then the Air Force made its routine denial. Why was McLaughlin, a regular Navy officer subject to security screening, permitted to give out this story? Was it an incredible slip-up? Or was it part of some carefully thought-out plan? I believe it was part of an elaborate program to prepare the American people for a dramatic disclosure. For almost a year I have watched the behind-the-scenes maneuvers of those who guide this program. In the following chapters I have tried to show the strange developments in our search for the answer; the carefully misleading tips, the blind alleys we entered, the unexpected assistance, the confidential leads, and the stunning contradictions. It has been a complicated jigsaw puzzle. Only by seeing all parts of this intricate picture can you begin to glimpse the reasons for this stubbornly hidden secret. The official explanation may be imminent. When it is finally revealed, I believe the elaborate preparation--even the wide deceit involved--will be fully justified in the minds of the American people. {p. 15} CHAPTER II IT HAS BEEN over two years since the puzzling death of Captain Thomas Mantell. Mantell died mysteriously in the skies south of Fort Knox. But before his radio went silent, he sent a strange message to Godman Air Force Base. The men who heard it will never forget it. It was January 7, 1948. Crowded into the Godman Field Tower, a group of Air Force officers stared up at the afternoon sky. For just an instant, something gleamed through the broken clouds south of the base. High above the field, three P-51 fighters climbed with swift urgency. Heading south, they quickly vanished. The clock in the tower read 2:45. Colonel Guy Hix, the C.O., slowly put down his binoculars. If the thing was still there, the clouds now hid it. All they could do was wait. The first alarm had come from Fort Knox, when Army M.P.'s had relayed a state police warning. A huge gleaming object had been seen in the sky, moving toward Godman Field. Hundreds of startled people had seen it at Madisonville, ninety miles away. Thirty minutes later, it had zoomed up over the base. Colonel Hix glanced around at the rest of the men in the tower. They all had a dazed look. Every man there had seen the thing, as it barreled south of the field. Even through the thin clouds, its intermittent red glow had hinted at some mysterious source of power. Something outside their understanding. It was Woods, the exec, who had estimated its size. Hix shook his head. That was unbelievable. But something had hung over Godman Field for almost an hour. The C.O. turned quickly as the loud-speaker, tuned to the P-51's, suddenly came to life. "Captain Mantell to Godman . . . Tower Mantell to Godman Tower . . ." {p. 16} The flight leader's voice had a strained tone. "I've sighted the thing!" he said. "It looks metallic--and it's tremendous in size!" The C.O. and Woods stared at each other. No one spoke. "The thing's starting to climb," Mantell said swiftly. "It's at twelve o'clock high, making half my speed. I'll try to close in." In five minutes, Mantell reported again. The strange metallic object had speeded up, was now making 360 or more. At 3:08, Mantell's wingman called in. Both he and the other pilot had seen the weird object. But Mantell had outclimbed them and was lost in the clouds. Seven minutes dragged by. The men in the tower sweated out the silence. Then, at 3:15, Mantell made a hasty contact. "It's still above me, making my speed or better. I'm going up to twenty thousand feet. If I'm no closer, I'll abandon chase." It was his last report. Minutes later, his fighter disintegrated with terrific force. The falling wreckage was scattered for thousands of feet. When Mantell failed to answer the tower, one of his pilots began a search. Climbing to 33,000 feet, he flew a hundred miles to the south. But the thing that lured Mantell to his death had vanished from the sky. Ten days after Mantell was killed, I learned of a curious sequel to the Godman affair. An A.P. account in the New York Times had caught my attention. The story, released at Fort Knox, admitted Mantell had died while chasing a flying saucer. Colonel Hix was quoted as having watched the object, which was still unidentified. But there was no mention of Mantell's radio messages--no hint of the thing's tremendous size. Though I knew the lid was probably on, I went to the Pentagon. When the scare had first broken, in the summer of '47, I had talked with Captain Tom Brown, who was handling saucer inquiries. But by now Brown had been {p. 17} shifted, and no one in the Press Branch would admit knowing the details of the Mantell saucer chase. "We just don't know the answer," a security officer told me. "There's a rumor," I said, "it's a secret Air Force missile that sometimes goes out of control." "Good God, man!" he exploded. "If it was, do you think we'd be ordering pilots to chase the damned things?" "No--and I didn't say I believed it." I waited until he cooled down. "This order you mentioned--is it for all Air Force pilots, or special fighter units?" "I didn't say it was a special order," he answered quickly. "All pilots have routine instructions to report unusual items." "They had fighters alerted on the Coast, when the scare first broke," I reminded him. "Are those orders still in force?" He shook his head. "No, not that I know of." After a moment he added, "All I can tell you is that the Air Force is still investigating. We honestly don't know the answer." As I went out the Mall entrance, I ran into Jack Daly, one of Washington's veteran newsmen. Before the war, Jack and I had done magazine pieces together, usually on Axis espionage and communist activity. I told him I was trying to find the answer to Mantell's death. "You heard anything?" I asked him. "Only what was in the A.P. story," said Jack. "But an I.N.S. man told me they had a saucer story from Columbus, Ohio--and it might have been the same one they saw at Fort Knox." "I missed that. What was it?" "They sighted the thing at the Air Force field outside of Columbus. It was around sundown, about two hours after that pilot was killed in Kentucky." "Anybody chase it?" I asked. "No. They didn't have time to take off, I guess. This I.N.S. guy said it was going like hell. Fast as a jet, anyway." "Did he say what it looked like?" {p. 18} "The Air Force boys said it was as big as a C-47," said Jack. "Maybe bigger. It had a reddish-orange exhaust streaming out behind. They could see it for miles." "If you hear any more, let me know," I said. Jack promised he would. "What do you think they are?" he asked me. "It's got me stumped. Russia wouldn't be testing missiles over here. Anyway, I can't believe they've got anything like that. And I can't see the Air Force letting pilots get killed to hide something we've got." One week later, I heard that a top-secret unit had been set up at Wright Field to investigate all saucer reports. When I called the Pentagon, they admitted this much, and that was all. In the next few months, other flying-disk stories hit the front pages. Two Eastern Airline pilots reported a double-decked mystery ship sighted near Montgomery, Alabama. I learned of two other sightings, one over the Pacific Ocean and one in California. The second one, seen through field glasses, was described as rocket-shaped, as large as a B-29. There were also rumors of disks being tracked by radar, but it was almost a year before I confirmed these reports. When Purdy wired me, early in May of '49, I had half forgotten the disks. It had been months since any important sightings had been reported. But his message quickly revived my curiosity. If he thought the subject was hot, I knew he must have reasons. When I walked into his office at 67 West 44th, Purdy stubbed out his cigarette and shook hands. He looked at me through his glasses for a moment. Then he said abruptly: "You know anything about the disks?" "If you mean what they are--no." He motioned for me to sit down. Then he swiveled his chair around, his shoulders hunched forward, and frowned out the window. "Have you seen the Post this week?" I told him no. "There's something damned queer going on. For fifteen months, Project 'Saucer' is buttoned up tight. Top secret. Then suddenly, Forrestal gets the Saturday Evening Post {p. 19} to run two articles, brushing the whole thing off. The first piece hits the stands--and then what happens?" Purdy swung around, jabbed his finger at a document on. his desk. "That same day, the Air Force rushes out this Project 'Saucer' report. It admits they haven't identified the disks in any important cases. They say it's still serious enough--wait a minute--"he thumbed through the stapled papers--" 'to require constant vigilance by Project "Saucer" personnel and the civilian population.'" "You'd think the Post would make a public kick," I said. "I don't mean it's an out-and-out denial," said Purdy. "It doesn't mention the Post--just contradicts it. In fact, the report contradicts itself. It looks as if they're trying to warn people and yet they're scared to say too much." I looked at the title on the report: "A Digest of Preliminary Studies by the Air Materiel Command, Wright Field, Dayton, Ohio, on 'Flying Saucers.'" "Have the papers caught it yet?" I asked Purdy. "You mean its contradicting the Post?" He shook his head. "No, the Pentagon press release didn't get much space. How many editors would wade through a six-thousand-word government report? Even if they did, they'd have to compare it, item for item, with the Post piece." "Who wrote the Post story?" Purdy lit a cigarette and frowned out again at the skyscrapers. "Sidney Shallett--and he's careful. He had Forrestal's backing. The Air Force flew him around, arranged interviews, supposedly gave him inside stuff. He spent two months on it. They O.K.'d his script, which practically says the saucers are bunk. Then they reneged on it." "Maybe some top brass suddenly decided it was the wrong policy to brush it off," I suggested. "Why the quick change?" demanded Purdy. "Let's say they sold the Post on covering up the truth, in the interests of security. It's possible, though I don't believe it. Or they could simply have fed them a fake story. Either {p. 20} Way, why did they rush this contradiction the minute the Post hit the stands?" "Something serious happened," I said, "after the Post went to press." "Yes, but what?" Purdy said impatiently. "That's what we've got to find out." "Does Shallett's first piece mention Mantell's death?" "Explains it perfectly. You know what Mantell was chasing? The planet Venus!" "That's the Post's answer?" I said, incredulously. "It's what the Air Force contract astronomer told Shallett. I've checked with two astronomers here. They say that even when Venus is at full magnitude you can barely see it in the daytime even when you're looking for it. It was only half magnitude that day, so it was practically invisible." "How'd the Air Force expect anybody to believe that answer?" I said. Purdy shrugged. "They deny it was Venus in this report. But that's what they told Shallett--that all those Air Force officers, the pilots, the Kentucky state police, and several hundred people at Madisonville mistook Venus for a metallic disk several hundred feet in diameter." "It's a wonder Shallett believed it." "I don't think he did. He says if it wasn't Venus, it must have been a balloon." "What's the Air Force answer?" I asked Purdy. "Look in the report. They say whatever Mantell chased--they call it a 'mysterious object'--is still unidentified." I glanced through the case report, on page five. It quoted Mantell's radio report that the thing was metallic and tremendous in size. Linked with the death of Mantell was the Lockbourne, Ohio, report, which tied in with what Jack Daly had told me, over a year before. I read the report: "On the same day, about two hours later, a sky phenomenon was observed by several watchers over Lockbourne Air Force Base, Columbus, Ohio. It was described as 'round or oval, larger than a C-47, and traveling in level {p. 21} flight faster than 500 miles per hour.' The object was followed from the Lockbourne observation tower for more than 20 minutes. Observers said it glowed from white to amber, leaving an amber exhaust trail five times its own length. It made motions like an elevator and at one time appeared to touch the ground. No sound was heard. Finally, the object faded and lowered toward the horizon." Purdy buzzed for his secretary, and she brought me a copy of the first Post article. "You can get a copy of this Air Force report in Washington," Purdy told me. "This is the only one I have. But you'll find the same answer for most of the important cases--the sightings at Muroc Air Base, the airline pilots' reports, the disks Kenneth Arnold saw--they're all unidentified." "I remember the Arnold case. That was the first sighting." "You've got contacts in Washington," Purdy went on. "Start at the Pentagon first. They know we're working on it. Sam Boal, the first man on this job, was down there for a day or two." "What did he find out?" "Symington told him the saucers were bunk. Secretary Johnson admitted they had some pictures--we'd heard about a secret photograph taken at Harmon Field, Newfoundland. The tip said this saucer scared hell out of some pilots and Air Force men up there. "A major took Boal to some Air Force colonel and Boal asked to see the pictures. The colonel said they didn't have any. He turned red when the major said Symington had told Boal about the pictures." "Did Boal get to see them?" I said. "No," grunted Purdy, "and I'll bet twenty bucks you won't, either. But try, anyway. And check on a rumor that they've tracked some disks with radar. One case was supposed to be at an Air Force base in Japan." As I was leaving, Purdy gave me a summary of sighting reports. "Some of these were published, some we dug up ourselves," he said. "We got some confidential stuff from {p. 22} airline pilots. It's pretty obvious the Air Force has tried to keep them quiet." "All right," I said. "I'll get started. Maybe things aren't sewed up so tightly, now this report is out." "We've found out some things about Project 'Saucer,' said Purdy. "Whether it's a cover-up or a real investigation, there's a lot of hush-hush business to it. They've got astronomers and astrophysicists working for them, also rocket expects, technical analysts, and Air Force Special Intelligence. We've been told they can call on any government agency for help--and I know they're using the F.B.I." It was building up bigger than I had thought. "If national security is involved," I told Purdy, "they can shut us up in a hurry." "If they tell me so, O.K.," said Purdy. He added grimly, "But I think they're making a bad mistake. They probably think they're doing what's right. But the truth might come out the wrong way." "It is possible," I thought, "that the saucers belong to Russia." "If it turns out to be a Soviet missile, count me out," I said. "We'd have the Pentagon and the F.B.I. on our necks." "All right, if that's the answer." He chuckled. "But you may be in for a jolt." {p. 23} CHAPTER III JUST THE idea of gigantic flying disks was incredible enough. It was almost as hard to believe that such missiles could have been developed without something leaking out. Yet we had produced the A-bomb in comparative secrecy, and I knew we were working on long-range guided missiles. There was already a plan for a three-thousand-mile test range. Our supersonic planes had hit around two thousand miles an hour. Our two-stage rockets had gone over two hundred miles high, according to reports. If an atomic engine had been secretly developed, it could explain the speed and range of the saucers. But I kept coming back to Mantell's death and the Air Force orders for pilots to chase the saucers. If the disks were American missiles, that didn't jibe. When I reached the lobby, I found it was ten after four. I caught a taxi and made the Congressional Limited with just one minute to spare. In the club car, I settled down to look at Purdy's summary. Skipping through the pages, I saw several familiar cases. Here and there, Purdy had scrawled brief comments or suggestions. Beside the Eastern Airline report of a double-decked saucer, he had written: "Check rumor same type seen over Holland about this date. Also, similar Philippine Islands report--date unknown." I went back to the beginning. The first case listed was that of Kenneth Arnold, a Boise businessman, who had set off the saucer scare. Arnold was flying his private plane from Chehalis to Yakima, Washington, when he saw a bright flash on his wing. Looking toward Mount Rainier, he saw nine gleaming disks outlined against the snow, each one about the size of a C-54. "They flew close to the mountaintops, in a diagonal chainlike line," he said later. "It was as if they were linked together." The disks appeared to be twenty to twenty-five miles {p. 24} away, he said, and moving at fantastic speed. Arnold's estimate was twelve hundred miles an hour. "I watched them about three minutes," he said. "They were swerving in and out around the high mountain peaks. They were flat, like a pie pan, and so shiny they reflected the sun like a mirror. I never saw anything so fast." The date was June 24, 1947. On this same day there was another saucer report. which received very little notice. A Portland prospector named Fred Johnson, who was working up in the Cascade Mountains, spotted five or six disks banking in the sun. He watched them through his telescope several seconds. then he suddenly noticed that the compass hand on his special watch was weaving wildly from side to side. Johnson insisted he had not heard of the Arnold report, which was not broadcast until early evening. Kenneth Arnold's story was generally received with amusement. Most Americans were unaware that the Pentagon had been receiving disk reports as early as January. The news and radio comments on Arnold's report brought several other incidents to light, which observers had kept to themselves for fear of ridicule. At Oklahoma City, a private pilot told Air Force investigators he had seen a huge round object in the sky during the latter part of May. It was flying three times faster than a jet, he said, and without any sound. Citizens of Weiser, Idaho, described two strange fast-moving objects they had seen on June 12. The saucers were heading southeast, now and then dropping to a lower altitude, then swiftly climbing again. Several mysterious objects were reported flying at great speed near Spokane, just three days before Arnold's experience. And four days after his encounter, an Air Force pilot flying near Lake Meade, Nevada, was startled to see half a dozen saucers flash by his plane. Even at this early point in the scare, official reports were contradicting each other. just after Arnold's story broke, the Air Force admitted it was checking on the mystery disks. On July 4 the Air Force stated that no further investigation was needed; it was all {p. 25} hallucination. That same day, Wright Field told the Associated Press that the Air Materiel Command was trying to find the answer. The Fourth of July was a red-letter day in the flying-saucer mystery. At Portland, Oregon, hundreds of citizens, including former Air Force pilots, police, harbor pilots, and deputy sheriffs, saw dozens of gleaming disks flying at high speed. The things; appeared to be at least forty thousand feet in the air--perhaps much higher. That same day, disks were sighted at Seattle, Vancouver, and other northwest cities. The rapidly growing reports were met with mixed ridicule and alarm. One of the skeptical group was Captain E. J. Smith, of United Airlines. "I'll believe them when I see them," he told airline employees, before taking off from Boise the afternoon of the Fourth. Just about sunset, his airliner was flying over Emmett, Idaho, when Captain Smith and his copilot, Ralph Stevens, saw five queer objects in the sky ahead. Smith rang for the stewardess, Marty Morrow, and the three of them watched the saucers for several minutes. Then four more of the disks came into sight. Though it was impossible to tell their size, because their altitude was unknown, the crew was sure they were bigger than the plane they were in. After about ten minutes the disks disappeared. The Air Force quickly denied having anything resembling the! objects Captain Smith described. "We have no experimental craft of that nature in Idaho--or anywhere else," an official said in Washington. "We're completely mystified." The Navy said it had made an investigation, and had no answers. There had been rumors that the disks were "souped-up" versions of the Navy's "Flying Flapjack," a twin-engined circular craft known technically as the XF-5-U-1. But the Navy insisted that only one model had been built, and that it was now out of service. In Chicago, two astronomers spiked guesses that the disks might be meteors. Dr. Girard Kieuper, director of the University of Chicago observatory, said flatly that they couldn't be meteors. {p. 26} "They're probably man-made," he told the A.P. Dr. Oliver Lee, director of Northwestern's observatory, agreed with Kieuper. "The Army, Navy, and Air Force are working secretly on all sorts of things," he said. "Remember the A-bomb secrecy--and the radar signals to the moon." As I went through Purdy's summary, I recalled my own reaction after the United Airlines report. After seeing the Pentagon comment, I had called up Captain Tom Brown, at Air Force Public Relations. "Are you really taking this seriously?" I asked him. "Well, we can't just ignore it," he said. "There are too many reliable pilots telling the same story--flat, round objects able to outmaneuver ordinary planes, and faster than anything we have. Too many stories tally." I told him I'd heard that the Civil Air Patrol in Wisconsin and other states was starting a sky search. "We've got a jet at Muroc, and six fighters standing by at Portland right now," Brown said. "Armed?" "I've no report on that. But I know some of them carry photographic equipment." Two days later an airline pilot from the Coast told me that some fighters had been armed and the pilots ordered to bring down the disks if humanly possible. That same day, Wright Field admitted it was checking stories of disk-shaped missiles seen recently in the Pacific northwest and in Texas. Following this was an A.P. story, dated July 7, quoting an unnamed Air Force official in Washington: "The flying saucers may be one of three things: "1. Solar reflection on low-hanging clouds. [A Washington scientist, asked for comment, said this was hardly possible.] "2. Small meteors which break up, their crystals catching the rays of the sun. But it would seem that they would have been spotted falling and fragments would have been found. "3. Icing conditions could have formed large hailstones, and they might have flattened out and glided a bit, giving {p. 27} the impression of horizontal movement even though falling vertically." By this time everyone was getting into the act. "The disks are caused by the transmutation of atomic energy," said an anonymous scientist, supposed to be on the staff of California Tech. The college quickly denied it. Dr. Vannevar Bush, world-famous scientist, and Dr. Merle Tuve, inventor of the proximity fuse, both declared they would know of any secret American missiles--and didn't. At Syracuse, New York, Dr. Harry Steckel, Veterans Administration psychiatrist, scoffed at the suggestion of mass hysteria. "Too many sane people are seeing the things. The government is probably conducting some revolutionary experiments." On July 8 more disks were reported. Out at Muroc Air Force Base, where top-secret planes and devices are tested, six fast-moving silvery-white saucers were seen by pilots and ground officers. That afternoon the Air Force revealed it was working on a case involving a Navy rocket expert named C. T. Zohm. While on a secret Navy mission to New Mexico, in connection with rocket tests, Zohm had seen a bright silvery disk flying above the desert. He was crossing the desert with three other scientists when he saw the strange object flashing northward at an altitude of about ten thousand feet. "I'm sure it was not a meteor," said Zohm. "It could have been a guided missile, but I never heard of anything like it." By this time, saucer reports had come in from almost forty states. Alarm was increasing, and there were demands that radar be used to track the disks. The Air Force replied that there was not enough radar equipment to blanket the nation, but that its pilots were on the lookout for the saucers. One report mentioned a curious report from Twin Falls, Idaho. The disk sighted there was said to have flown so low that the treetops whirled as if in a violent storm. Someone had phoned Purdy about a disk tracked {p. 28} by weather-balloon observers at Richmond, Virginia. There was another note on a sighting at Hickam Field, Honolulu, and two reports of unidentified objects seen near Anchorage, Alaska. A typed list of world-wide sightings had been made up by the staff at True. It contained many cases that were new to me, reports from Paraguay, Belgium, Turkey, Holland, Germany, and the Scandinavian countries. At the bottom of this memo Purdy had written: "Keep checking on rumor that the Soviet has a Project Saucer, too. Could be planted." From the mass of reports, John DuBarry, the aviation editor of True, had methodically worked out an average picture of the disks: "The general report is that they are round or oval (this could be an elliptical object seen end-on), metallic looking, very bright--either shining white or silvery colored. They can move at extremely high speed, hover, accelerate rapidly, and outmaneuver ordinary aircraft. "The lights are usually seen singly--very few formations reported. They seem to have the same speed, acceleration, and ability to maneuver. In several cases, they have been able to evade Air Force planes in night encounters." Going over the cases, I realized that Purdy and his staff had dug up at least fifty reports that had not appeared in the papers. (A few of these proved incorrect, but a check with the Air Force case reports released on December 30, 1949, showed that True's files contained all the important items.) These cases included sightings at eleven Air Force bases and fourteen American airports, reports from ships at sea, and a score of encounters by airline and private pilots. Witnesses included Army, Navy, Marine Corps, and Air Force officers; state and city police; F.B.I. agents; weather observers, shipmasters, astronomers, and thousands of good solid American citizens. I learned later that many witnesses had been investigated by the F.B.I. to weed out crackpot reports. I ended up badly puzzled. The evidence was more impressive than I had suspected. It was plain that many {p. 29} reports had been entirely suppressed, or at least kept out of the papers. There was something ominous about it. No matter what the answer, it was serious enough to be kept carefully hidden. If it were a Soviet missile, I thought, God help us. They'd scooped up a lot of Nazi scientists and war secrets. And the Germans had been far ahead of us on guided missiles. But why would they give us a two-year warning, testing the things openly over America? It didn't make sense. {p. 30} CHAPTER IV I WENT to the Pentagon the next morning. I didn't expect to learn much, but I wanted to make sure we weren't tangling with security. I'd worked with Al Scholin and Orville Splitt, in the magazine section of Public Relations, and I thought they'd tell me as much as anyone. When I walked in, I sprang it on them cold. "What's the chance of seeing your Project 'Saucer' files?" Al Scholin took it more or less dead-pan. Splitt looked at me a moment and then grinned. "Don't tell me you believe the things are real?" "Maybe," I said. "How about clearing me with Project 'Saucer'?" Al shook his head. "It's still classified secret." "'Look, Don," said Splitt, "why do you want to fool with that saucer business? There's nothing to it." '"That's a big change from what the Air Force was saying; in 1947," I told him. He shrugged that off. "The Air Force has spent two years checking into it. Everybody from Symington down will tell you the saucers are bunk." "That's not what Project 'Saucer' says in that April report." "That report was made up a long time ago," said Splitt. "They just got around to releasing it." "Then they've got all the answers now?" "They know there's nothing to it," Splitt repeated. "In that case," I said, "Project 'Saucer' shouldn't object to my seeing their files and pictures." "What pictures?" "That one taken at Harmon Field, Newfoundland, for a starter." "Oh, that thing," said Splitt. "It wasn't anything--just a shadow on a cloud. Somebody's been kidding you." "If it's just a cloud shadow, why can't I see it?" Splitt was getting a little nettled. {p. 31} "Look, you know how long it takes to declassify stuff. They just haven't got around to it. Take my word for it, the flying saucers are bunk. I went around with Sid Shallett on some of his interviews. What he's got in the Post is the absolute gospel." "It's funny about that April twenty-seventh report," I said, "the way it contradicts the Post." "I tell you that was an old report--" "I wouldn't say that," Al Scholin put in. "The Air Force doesn't claim it has all the answers. But they've proved a lot of the reports were hoaxes or mistakes." "Just the same," I said, "the Air Force is on record, as of April twenty-seventh, that it's serious enough for everybody to be vigilant. And they admit most of the things, in the important cases, are still unidentified. Including the saucer Mantell was chasing." "That business at Godman Field was some kind of hallucination," insisted Splitt. "I suppose all those pilots and Godman Field officers were hypnotized? Not to mention several thousand people at Madisonville and Fort Knox?" "Take it easy, you guys," said Al Scholin. "You've both got a right to your opinions." "Oh, sure," said Splitt. He looked at me, with his grin back. "I don't care if you think they're men from Mars." "Let's not go off the deep end," I said. "Tell me this: Did Shallett get to see any secret files at Wright Field?" "Absolutely not." "Then he had to take the Air Force word for everything?" "Not entirely. We set up some interviews for him." "One more thing--and don't get mad. If it's all bunk, why haven't they closed Project 'Saucer'?" "How do I know? Probably no one wants to take the responsibility." "Then somebody high up must not think it's bunk," I said. Splitt laughed. "Have it your own way." Before I left, I told them I was working with True. "I want to be on record," I said, "as having told you {p. 32} this. If there's any security involved--if you tell me it's something you're working on--naturally I'll lay off." Al Scholin said emphatically, "It's not an Air Force device, if that's what you mean." "Some people think it's Russian." "If it is, I don't know it," said Al, "and neither does the Air Force." After I left the magazine section, I tried several officers I knew. Two of them agreed with Splitt. The third didn't. "I've been told it's all bunk," he said, "but you get the feeling they've trying to convince themselves. They act like people near a haunted house. They'll swear it isn't haunted--but they won't go near it." Later, I asked a security major for a copy of the Project "Saucer" report. "We're out of copies right now," he said. "I'll send you one next week." I asked him bluntly what he thought the saucers were. "I doubt if anybody has the full answer," he said seriously. "There's been some hysteria--also a few mistakes. But many reports have been made by reliable pilots, including our own. You can't laugh those off." As I drove home, I thought over what I'd heard. All I had learned was that the Air Force seemed divided. But that could be a smoke screen. In less than twenty-four hours, I received my first suspicious tip. It was about ten A.M. when my phone rang. "Mr. Keyhoe? This is John Steele," said the voice at the other end. (Because of the peculiar role he played, then and later, I have not used his real name.) "I'm a former Air Force Intelligence officer. I was in the European theater during the war." I waited. He hesitated a moment. "I heard you're working on the flying-saucer problem," he said quickly. "I may have some information that would interest you." "Mind telling me who told you I was on it?" I asked. "No one, directly. I just happened to hear it mentioned at the Press Club. Frankly, I've been curious about the flying saucers ever since '45." That startled me, but I didn't tell him so. {p. 53} "Do you have any idea what they are?" Mr. Steele said. "No, I've just begun checking. But I'd be glad to hear what you've got." "I may be way off," said Steele. "But I've always wondered about the 'foo fighters' our pilots saw over Europe near the end of the war." I thought for a second. "Wasn't that some kind of antiaircraft missile fired from the ground?" "No. Intelligence never did get any real answer, so far as I know. They were some kind of circular gadgets, and they actually chased our planes a number of times. We thought they were something the Nazis had invented--and I still think so." "Then who's launching them now?" "Well, it's obviously either Russia or us. If it is the Soviet--well, that's what's worried me. I don't think it should be treated like a joke, the way some people in the Pentagon take it." I stared at the phone, trying to figure him out. "I'd like to talk it over with you," I said. "Maybe you've got something." "I've given you about all I know," Steele answered. "There was an Intelligence report you might try to see--the Eighth Air Force files should have it." "Wait a minute," I said. "Give me your number, in case I find anything." He gave it to me without apparent hesitation. I thanked him and hung up, still wondering. If it was an attempt at a plant, it was certainly crude. The mention of his former Air Force connection would be enough to arouse suspicion, unless he counted on his apparent frankness to offset it. And what about the Press Club angle? That would indicate Steele was a newspaperman. Could this be merely an attempt to pump me and get a lead on True's investigation? But that would be just as crude as the other idea. Of course, he might be sincere. But regardless of his motives, it looked bad. Arid who had told him about me? I thought about that for a minute. Then I picked up the phone and dialed Jack Daly's number. {p. 34} "Jack, do you know anyone named John Steele?" I asked him. "I think he's a newspaperman." "Nobody I know," said Jack. "Why, what's up?" I explained, and added, "I thought maybe you knew him, and he'd heard about it from you." "Hell, no," said Jack. "You ought to know I wouldn't leak any tip like that." "It wouldn't be a tip--I don't know anything about this deal yet. By the way, when you were on the Star did you handle anything on 'foo fighters'?" "No, that was after I left there. Bill Shippen would have covered that, anyway." I told him I would look it up in the Star's morgue. Jack said he would meet me there at three o'clock; in the meantime he would see what he could find out about Steele. Jack was a little late, and I went over the Star's file on the foo fighters. Most of the facts were covered in a story dated July 6, 1947, which had been inspired by the outbreak of the saucer scare. I copied it for later use: During the latter part of World War Two, fighter pilots in England were convinced that Hitler had a new secret weapon. Yanks dubbed these devices "foo fighters" or "Kraut fireballs." One of the Air Force Intelligence men now assigned to check on the saucer scare was an officer who investigated statements of military airmen that circular foo fighters were seen over Europe and also on the bombing route to Japan. It was reported that Intelligence officers have never obtained satisfactory explanation of reports of flying silver balls and disks over Nazi-occupied Europe in the winter of 1944-45. Later, crews of B-29'S on bombing runs to Japan reported seeing somewhat similar objects. In Europe, some foo fighters danced just off the Allied fighters' wingtips and played tag with them in power dives. Others appeared in precise formations and on one occasion a whole bomber crew {p. 35} saw about 15 following at a distance, their strange glow flashing on and off. One foo fighter chased Lieutenant Meiers of Chicago some 20 miles down the Rhine Valley, at 300 m.p.h., an A.P. war correspondent reported. Intelligence officers believed at that time that the balls might be radar-controlled objects sent up to foul ignition systems or baffle Allied radar networks. There is no explanation of their appearance here, unless the objects could have been imported for secret tests in this country. I read the last paragraph twice. This looked like a strong lead to the answer, in spite of the Air Force denials. There was another, less pleasant possibility. The Russians could have seized the device and developed it secretly, using Nazi scientists to help them. Perhaps the Nazis had been close to an atomic engine, even if they did fail to produce the bomb. Jack Daly came in while I was reading the story again. "I got the dope on Steele," he said. "He does pieces for a small syndicate, and I found out he was in the Air Force. I think he was a captain. People who know him say he's O.K.--a straight shooter." "That still wouldn't keep him from giving me a fake tip, if somebody told him it was the right thing to do." "Maybe not," said Jack, "but why would they want to plant this foo-fighter idea?" I showed him the clipping. He read it over and shook his head. "That's a lot different from disks three hundred feet in diameter." "If we got the principle--or Russia did-building big ones might not be too hard." "I still can't swallow it," said Jack. "These things have been seen all over the world. How could they control them that far away--and be sure they wouldn't crash, where somebody could get a look and dope out the secret?" We argued it back and forth without getting anywhere. {p. 36} "I'd give a lot to know Steele's angle," I said. "If you hear anything more on him, give me a buzz." Jack nodded. "I'll see what I can do. But I can't dig too hard, or he'll hear about it." On the way out, I found a phone booth and called Splitt. "Foo fighters?" he said. "Sure, I remember those stories. You think those are your flying saucers?" I could hear him snicker. "Just checking angles," I said. "Didn't the Eighth Air Force investigate the foo fighters?" "Yes, and they found nothing to back up the pilots' yarns. just war nerves, apparently." "How about a look at the Intelligence report?" I asked. "Wait a minute." Splitt was gone for twice that time, then he carne back. "Sorry, it's classified." "If all this stuff is bunk, why keep the lid on it?" I demanded. I was getting sore again. "Look, Don," said Splitt, "I don't make the rules." "Sure, I know--sorry," I said. I had a notion to ask him if he knew John Steele, but hung up instead. There was no use in banging my head against the Air Force wall. The next day I decided to analyze the Mantell case from beginning to end. It looked like the key to one angle: the question of an Air Force secret missile. Unless there was some slip-up, so that Mantell and his pilots had been ordered to chase the disk by mistake, then it would be cold murder. I couldn't believe any Air Force officer would give such an order, no matter how tremendous the secret to be hidden. But I was going to find out, if possible. {p. 37} CHAPTER V FOR MORE than two weeks, I checked on the Godman Field tragedy. One fact stood out at the start: The death of Mantell had had a profound effect on many in the Air Force. A dozen times I was told: "I thought the saucers were a joke-until Mantell was killed chasing that thing at Fort Knox." Many ranking officers who had laughed at the saucer scare stopped scoffing. One of these was General Sory Smith, now Deputy Director of Air Force Public Relations. Later in my investigation, General Smith told me: "It was the Mantell case that got me. I knew Tommy Mantell. very well--also Colonel Hix, the C.O. at Godman. I knew they were both intelligent men--not the kind to be imagining things." For fifteen months, the Air Force kept a tight-lipped silence. Meantime, rumors began to spread. One report said that Mantell had been shot, his body riddled with bullets; his P-51, also riddled, had simply disintegrated. Another rumor reported Mantell as having been killed by some mysterious force; this same force had also destroyed his fighter. The Air Force, the rumors said, had covered up the truth by telling Mantell's family he had blacked out from lack of oxygen. Checking the last angle, I found that this was the explanation given to Mantell's mother, just after his death, she was told by Standiford Field officers that he had flown too high in chasing the strange object. Shallet, in the Saturday Evening Post articles, described Project "Saucer's" reconstruction of the case. Mantell was said to have climbed up to 25,000 feet, despite his firm decision to end the chase at 20,000, since he carried no oxygen. Around 25,000 feet, Shallett quoted the Air Force investigators, Mantell must have lost consciousness. After this, his pilotless plane climbed on up to some 30,000 feet, then dived. Between 20,000 and 10,000 feet, Shallett suggested, the P-51 began to disintegrate, obviously from excessive speed. The gleaming object that {p. 38} hypnotized Mantell into this fatal climb was, Shallett said, either the planet Venus or a Navy cosmic-ray research balloon. The Air Force Project "Saucer" report of April 27, 1949, released just after the first Post article, makes these statements: "Five minutes after Mantell disappeared from his formation, the two remaining planes returned to Godman. A few minutes later, one resumed the search, covering territory 100 miles to the south as high as 33,000 feet, but found nothing. "Subsequent investigation revealed that Mantell had probably blacked out at 20,000 feet from lack of oxygen and had died of suffocation before the crash. "The mysterious object which the flyer chased to his death was first identified as the Planet Venus. However, further probing showed the elevation and azimuth readings of Venus and the object at specified time intervals did not coincide. "It is still considered 'Unidentified.' The Venus explanation, even though now denied, puzzled me. It was plain that the Air Force had seriously considered offering it as the answer then abandoned it. Apparently someone had got his signals mixed and let Shallett use the discarded answer. And for some unknown reason, the Air Force had found it imperative to deny the Venus story at once. In these first weeks of checking, I had run onto the Venus explanation in other cases. Several Air Force officers repeated it so quickly that it had the sound of a stock alibi. But in the daytime cases this was almost ridiculous. I knew of a few instances in World War II when bomber crews and antiaircraft gunners had loosed a few bursts at Venus. But this was mostly at night, when the planet was at peak brilliance. And more than one gunner later admitted firing to relieve long hours of boredom. Since enemy planes did not carry lights, there was no authentic case, to my knowledge, where plane or ground gunners actually believed Venus was an enemy aircraft. {p. 39} Checking the astronomer's report, I read over the concluding statement: "It simply could not have been Venus. They must have been desperate even to suggest it in the first place." Months later, in the secret Project "Saucer" report released December 30, 1949, I found official confirmation of this astronomer's opinions. Since it has a peculiar bearing on the Mantell case, I am quoting it now: When Venus is at its greatest brilliance, it is possible to see it during daytime when one knows exactly where to look. But on January 7, 1948, Venus was less than half as bright as its peak brilliance. However, under exceptionally good atmospheric conditions, and with the eye shielded from direct rays of the sun, Venus might be seen as an exceedingly tiny bright point of light. . . . However, the chances of looking at just the right spot are very few. It has been unofficially reported that the object was a Navy cosmic-ray research balloon. If this can be established, it Is to be preferred as an explanation. However, if one accepts the assumption that reports from various other localities refer to the same object, any such device must have been a good many miles high--25 to 50--in order to have been seen clearly, almost simultaneously, from places 175 miles apart. If all reports were of a single object, in the knowledge of this investigator no man-made object could have been large enough and far enough away for the approximate simultaneous sightings. It is most unlikely, however, that so many separated persons should at that time have chanced on Venus in the daylight sky. It seems therefore much more probable that more than one object was involved. The sighting might have included two or more balloons (or aircraft) or they might have included Venus and balloons. For reasons given above, the latter explanation seems more likely. {p. 40} Two things stand out in his report: 1. The obvious determination to fit some explanation, no matter how farfetched, to the Mantell sighting. 2. The impossibility that Venus--a tiny point of light, seen only with difficulty--was the tremendous metallic object described by Mantell and seen by Godman Field officers. With Venus eliminated, I went to work on the balloon theory. Since I had been a balloon pilot before learning to fly planes, this was fairly familiar ground. Shallett's alternate theory that Mantell had chased a Navy research balloon was widely repeated by readers unfamiliar with balloon operation. Few thought to check the speeds, heights, and distances involved. Cosmic-ray research balloons are not powered; they are set free to drift with the wind. This particular Navy type is released at a base near Minneapolis. The gas bag is filled with only a small per cent of its helium capacity before the take-off. In a routine flight, the balloon ascends rapidly to a very high altitude-as high as 100,000 feet. By this time the gas bag has swelled to full size, about l00 feet high and 70 feet in diameter. At a set time, a device releases the case of instruments under the balloon. The instruments descend by parachute, and the balloon, rising quickly, explodes from the sudden expansion. Occasionally a balloon starts leaking, and it then remains relatively low. At first glance, this might seem the answer to the Kentucky sightings. If the balloon were low enough, it would loom up as a large circular object, as seen from directly below. Some witnesses might estimate its diameter as 250 feet or more, instead of its actual 70 feet. But this failure to recognize a balloon would require incredibly poor vision on the part of trained observers--state police, Army M.P.'s, the Godman Field officers, Mantell and his pilots. Captain Mantell was a wartime pilot, with over three thousand hours in the air. He was trained to identify a distant enemy plane in a split second. His vision was perfect, and so was that of his pilots. In broad daylight {p. 41} they could not fail to recognize a balloon during their thirty-minute chase. Colonel Hix and the other Godman officers watched the object with high-powered glasses for long periods. It is incredible that they would not identify it as a balloon. Before its appearance over Godman Field, the leaking balloon would have drifted, at a low altitude, over several hundred miles. (A leak large enough to bring it down from high altitude would have caused it to land and be found.) Drifting at a low altitude, it would have been seen by several hundred thousand people, at the very least. Many would have reported it as a balloon. But even if this angle is ignored it still could not possibly have been a balloon at low altitude. The fast flight from Madisonville, the abrupt stop and hour-long hovering at Godman Field, the quick bursts of speed Mantell reported make it impossible. To fly the go miles from Madisonville to Fort Knox in 30 minutes, a balloon would require a wind of 180 m.p.h. After traveling at this hurricane speed, it would then have had to come to a dead stop above Godman Field. As the P-51's approached, it would have had to speed tip again to 180, then to more than 360 to keep ahead of Mantell. The three fighter pilots chased the mysterious object for half an hour. (I have several times chased balloons with a plane, overtaking them in seconds.) In a straight chase, Mantell would have been closing in at 360; the tail wind acting on his fighter would nullify the balloon's forward drift. But even if you accept these improbable factors, there is one final fact that nullifies the balloon explanation. The strange object had disappeared when Mantell's wingman searched the sky, just after the leader's death. If it had been a balloon held stationary for an hour at a high altitude, and glowing brightly enough to be seen through clouds, it would have remained visible in the same general position. Seen from 33,000 feet, it would have been even brighter, because of the clearer air. But the mysterious object had completely vanished in {p. 42} those few minutes. A search covering a hundred miles failed to reveal a trace. Whether at a high or low altitude, a balloon could not have escaped the pilot's eyes. It would also have continued to be seen at Godman Field and other points, through occasional breaks in the clouds. I pointed out these facts to one Air Force officer at the Pentagon. Next day he phoned me: "I figured it out. The timing device went off and the balloon exploded. That's why the pilot didn't see it." "It's an odd coincidence," I said, "that it exploded in those five minutes after Mantell's last report." "Even so, it's obviously the answer," he said. Checking on this angle, I found: 1. No one in the Kentucky area had reported a descending parachute. 2. No cosmic-ray research instrument case or parachute was found in the area. 3. No instruments were returned to the Navy from this region. And all balloons and instruments released at that time were fully accounted for. Even if it had been a balloon, it would not explain the later January 7th reports--the simultaneous sightings mentioned by Professor Hynek in the Project "Saucer" report. This includes the thing seen at Lockbourne Air Force Base two hours after Mantell's death. Obviously, the saucer seen flying at 500 m.p.h. over Lockbourne Field could not have been a balloon. Even if there had been several balloons in this area (and there were not, by official record), they could not have covered the courses reported. In some cases, they would have been flying against the wind, at terrific speed. Then what was the mysterious object? And what killed Mantell? Both the Air Force and the Post articles speculate that Mantell carelessly let himself black out. Since some explanation had to be given, this might seem a good answer. But Mantell was known for coolheaded judgment. As a wartime pilot, he was familiar with signs of anoxia (oxygen starvation). That he knew his tolerance for altitude is proved by his firmly declared {p. 43} intention to abandon the chase at 20,000 feet, since he had no oxygen equipment. Mantell had his altimeter to warn him. From experience, he would recognize the first vague blurring, narrowing of vision, and other signs of anoxia. Despite this, the "blackout" explanation was accepted as plausible by many Americans. While investigating the Mantell case, I talked with several pilots and aeronautical engineers. Several questioned that a P-51 starting a dive from 20,000 feet would have disintegrated so thoroughly. "From thirty thousand feet, yes," said one engineer. "If the idea was to explain it away, I'd pick a high altitude to start from. But a pilotless plane doesn't necessarily dive, as you know. "It might slip off and spin, or spiral down, and a few have even landed themselves. Also, if the plane started down from twenty thousand, the pilot wouldn't be too far blacked out. The odds are he'd come to when he got into thicker air--admitting he did blur out, which is only an Air Force guess. I don't see why they're so positive Mantell died before he hit the ground--unless they know something we don't." One of the pilot group put it more bluntly. "It looks like a cover-up to me. I think Mantell did just what he said he would--close in on the thing. I think he either collided with it, or more likely they knocked him out of the air. They'd think he was trying to bring them down, barging in like that." Even if you accept the blackout answer, it still does not explain what Mantell was chasing. it is possible that, excited by the huge, mysterious object, he recklessly climbed beyond the danger level, though such an act was completely at odds with his character. But the identity of the thing remains--officially--a mystery. If it was some weird experimental craft or a guided missile, then whose was it? Air Force officers had repeatedly told me they had no such device. General Carl Touhy Spaatz, former Air Force chief, had publicly insisted that no such weapon had been developed in his regime. Secretary Symington and General Hoyt Vandenberg, {p. 44} present Air Force chief, had been equally emphatic. Of course, official denials could be expected if it were a top-level secret. But if it were a secret device, would it be tested so publicly that thousands would see it? If it were an Air Force device, then I could see only one answer for the Godman Field incident: The thing was such a closely guarded secret that even Colonel Hix hadn't known. That would mean that most or all Air Force Base C.O.'s were also in ignorance of the secret device. Could it be a Navy experiment, kept secret from the Air Force? I did a little checking. Admiral Calvin Bolster, chief of aeronautics research experimental craft, was an Annapolis classmate of mine. So was Captain Delmer S. Fahrney, head of the Navy guided-missile program. Fahrney was at Point Mugu, missile-testing base in California, and I wasn't able to see him. But I knew him as a careful, conscientious officer; I can't believe he would let such a device, piloted or not, hover over an Air Force base with no warning to its C.O. I saw Admiral Bolster. His denial seemed genuine; unless he'd got to be a dead-pan poker player since our earlier days, I was sure he was telling the truth. The only other alternate was Russia. It was incredible that they would develop such a device and then expose it to the gaze of U.S. Air Force officers. It could be photographed, its speed and maneuverability checked; it might crash, or antiaircraft fire might bring it down, The secret might be lost in one such test flight. There was one other explanation: The thing was not intended to be seen; it had got out of control. In this event; the long hovering period at Godman Field was caused by the need for repairs inside the flying saucer, or repairs to remote-control apparatus. If it were Air Force or Navy, that would explain official concern; even if completely free of negligence, the service responsible would be blamed for Mantell's death. If it were Russian, the Air Force would of course try to conceal the fact for fear of public hysteria. But if the device was American, it meant that Project {p. 45} "Saucer" was a cover-up unit. While pretending to investigate, it would actually hush up reports, make false explanations, and safeguard the secret in every possible way. Also, the reported order for Air Force pilots to pursue the disks would have to be a fake. Instead, there would be a secret order telling them to avoid strange objects in the sky. By the time I finished my check-up, I was sure of one thing: This particular saucer had been real. I was almost positive of one other point-that the thing had been over 30 miles high during part of its flight. I found that after Mantell's death it was reported simultaneously from Madisonville, Elizabethtown, and Lexington--over a distance of 175 miles. (Professor Hynek's analysis later confirmed this.) How low it had been while hovering over Godman, and during Mantell's chase, there was no way to determine. But all the evidence pointed to a swift ascent after Mantell's last report. Had Mantell told Godman Tower more than the Air Force admitted? I went back to the Pentagon and asked for a full transcript of the flight leader's radio messages. I got a quick turn-down. The reports, I was told, were still classified as secret. Requests for pictures of the P-51 wreckage, and for a report on the condition of Mantell's body, also drew a blank. I had heard that some photographs were taken of the Godman Field saucer from outside the tower. But the Air Force denied knowledge of any such pictures. Puzzling over the riddle, I remembered John Steele, the former Intelligence captain. If by any chance he was a plant, it would be interesting to suggest the various answers and watch his reaction. When I phoned him to suggest luncheon, Steele accepted at once. We met at the Occidental, on Pennsylvania Avenue. Steele was younger than I had expected--not over twenty-five. He was a tall man, with a crew haircut and the build of a football player. Looking at him the first time, I expected a certain breeziness. instead, he was almost solemn. "I owe you an apology," he said in a careful voice after {p. 46} we'd ordered. "You probably know I'm a syndicate writer?" I wondered if he'd found out Jack Daly was checking on him. "When you mentioned the Press Club," I said, "I gathered you were in the business." "I'm afraid you thought I was fishing for a lead." Steele looked at me earnestly. "I'm not working on the story--I'm tied up on other stuff." "Forget it," I told him. He seemed anxious to reassure me. "I'd been worried for some time about the saucers. I called you that night on an impulse." "Glad you did," I said. "I need every tip I can get." "Did it help you any?" "Yes, though it still doesn't fit together. But I can tell you this: The saucers are real, or at least one of them." "Which one?" "The thing Captain Mantell was chasing near Fort Knox, before he died." "Oh, that one." Steele looked down at the roll he was buttering. "I thought that case was fully explained. Wasn't he chasing a balloon?" "The Air Force says it's still unidentified." I told him what I had learned. "Apparently you're right--it's either an American or a Soviet missile." "After what you've told me," said Steele, "I can't believe it's ours. It must be Russian." "They'd be pretty stupid to test it over here." "You said it was probably out of control." "That particular one, maybe. But there have been several hundred seen over here. If they found their controls were haywire, they wouldn't keep testing the things until they'd corrected that." The waiter came with the soup, and Steele was silent until he left. "I still can't believe it's our weapon," he said slowly. "They wouldn't have Air Force pilots alerted to chase the things. And I happen to how they do." "There's something queer about this missile angle," I said. "That saucer was seen at the same time by people a {p. 47} hundred and seventy-five miles apart. To be that high in the sky, and still look more than two hundred and fifty feet in diameter, it must have been enormous." Steele didn't answer for a moment. "Obviously, that was an illusion," he finally answered. "I'd discount those estimates." "Even Mantell's? And the Godman Field officers'?" "Not knowing the thing's height, how could they judge accurately?" "To be seen at points that far apart, it had to be over thirty miles high," I told him. "It would have to be huge to show up at all." He shook his head. "I can't believe those reports are right. It must have been sighted at different times." I let it drop. "What are you working on now?" Steele asked, after a minute or two. I said I hadn't decided. Actually, I planned a trip to the coast, to interview pilots who had sighted flying disks. "What would you do if you found it wasn't a Soviet missile?" said Steele. He sounded almost too casual. "If security was involved, I'd keep still. But the Air Force and the Navy swear they haven't any such things." Steele looked at me thoughtfully. "You know, True might force something into the open that would be better left secret." He smiled ironically. "I realize that sounds peculiar, since I suggested the Russian angle. But if it isn't Russian--though I still think it is--then we have nothing to worry about." I was almost sure now that he was a plant. During the rest of the luncheon, I tried to draw him out, but Steele was through talking. When we parted, he gave me a sober warning. "You and True should consider your moral responsibility, no matter what you find. Even if it's not actual security, there may be reasons to keep still." After he left me, I tried to figure it out. If the Air Force was back of this, they must not think much of my intelligence. Or else they had been in such a hurry to get a line on True's investigation that they had no choice but {p. 48} to use Steele. Of course, it was still possible he was doing this on his own, Either way, his purpose was obvious. He hoped to have us swallow the Soviet-missile answer. If we did, then we would have to keep still, even though we found absolute proof. Obviously, it would be dangerous to print that story. Thinking back, I recalled Steele's apparent attempt to dismiss the Mantell case. I was convinced now. The Godman Field affair must hold an important clue that I had overlooked. It might even be the key to the whole flying saucer riddle. {p. 49} CHAPTER VI SHORTLY after my talk with Steele, I flew to the Coast. For three weeks I investigated sightings that had been reported by airline and private pilots and other competent witnesses. At first, the airline pilots were reluctant to talk. Most of them remembered the ridicule that had followed published accounts by other airline men. One pilot told me he had been ordered to keep still about his experience--whether by the company or the Air Force, he would not say. But most of them finally agreed to talk, if I kept their names out of print. One airline captain--I'll call him Blake--had encountered a saucer at night. He and his copilot had sighted the object, gleaming, in the moonlight, half a mile to their left. "We were at about twelve thousand feet," he said, when we saw this thing pacing us. It didn't have any running lights, but we could see the moonlight reflecting from something like bright metal. There was a glow along the side, like some kind of light, or exhaust." "Could you make out the shape?" I asked. Blake grinned crookedly. "You think we didn't try? I cut in toward it. It turned in the same direction. I pulled up about three hundred feet, and it did the same. Finally, I opened my throttles and cut in fast, intending to pull tip if we got too close. I needn't have worried. The thing let out a burst of reddish flame and streaked up out of sight. It was gone in a few seconds." "Then it must have been piloted," I said. "If not, it had some kind of radar-responder unit to make it veer off when anything got near it. It matched every move I made, until the last one." I asked him what he thought the saucer was. Blake hesitated, then he gave me a slow grin. "Well, my copilot thinks it was a space ship. He says no pilot here on earth could take that many G's, when the thing zoomed." {p. 50} I'd heard some "men from Mars" opinions about the saucers, but this was an experienced pilot. "You don't believe that?" I said. "No," Blake said. "I figure it was some new type of guided missile. If it took as many G's as Chuck, my copilot, thinks, then it must have been on a beam and remote-controlled." Later, I found two other pilots who had the same idea as Chuck. One captain was afraid the flying saucers were Russian; his copilot thought they were Air Force or Navy. I met one airline official who was indignant about testing such missiles near the airways. "Even if they do have some device to make them veer off," he said, "I think it's a risk. There'll be hell to pay if one ever hits an airliner." "They've been flying around for two years," a line pilot pointed out. "Nobody's had a close call yet. I don't think there's much danger." When I left the Coast, I flew to New York. Ken Purdy called in John DuBarry, True's aviation editor, to hear the details. Purdy called him "John the Skeptic." After I told them what I had learned Purdy nodded. "What do you think the saucers are?" asked DuBarry. "They must be guided missiles," I said, "but it leaves some queer gaps in the picture." I had made up a list of possible answers, and I read it to them: "One, the saucers don't exist. They're caused by mistakes, hysteria, and so on. Two, they're Russian guided missiles. Three, they're American guided missiles. Four, the whole thing is a hoax, a psychological-warfare trick." "You mean a trick of ours?" said Purdy. "Sure, to make the Soviets think we could reach them with a guided missile. But I don't think that's the answer--I just listed it as a possibility." DuBarry considered this thoughtfully. "In the first place, you'd have to bring thousands of people into the scheme, so the disks would be reported often enough to get publicity. You'd have to have some kind of device, maybe something launched from highflying bombers, to give the rumors substance. They'd {p. 51} certainly do a better job than this, to put it over. And it wouldn't explain the world-wide sightings. Also, Captain Mantell wouldn't kill himself just to carry out an official hoax." "John's right," said Purdy. "Anyway, it's too ponderous. It would leak like a sieve, and the dumbest Soviet agent would see through it." He looked back at my list. "Cross off Number One, There's too much competent testimony, beside the obvious fact that something's being covered up." "That leaves Russian or American missiles," I said, "as Steele first suggested. But there are some points that just won't fit the missile theory." "You've left out one answer," said Purdy. "What's that?" "Interplanetary." "You're kidding!" I said. "I didn't say I believed it," said Purdy. "I just say it's possible." DuBarry was watching me. "I know how you feel. That's how it hit me when Ken first said it," "I've heard it before," I said. "But I never took it seriously." "Maybe this will interest you," Purdy said. He gave me a note from Sam Boal: "Just talked with D-------," the note ran. (D------- is a prominent aeronautical engineer, the designer of a world-famous plane.) "He believes the disks may be interplanetary and that the Air Force knows it--or at least suspects it. I'm enclosing sketches showing how he thinks the disks operate." "He's not the first one who told us that," said Purdy. "We've heard the same thing from other engineers. Over a dozen airline pilots think they're coining from out in space. And there's a rocket expert at Wright Field who's warned Project 'Saucer' that the things are interplanetary. That's why I'm not writing it off." "Have you read the Project 'Saucer' ideas on space travel?" DuBarry asked me. I told him my copy hadn't reached me. He read me some marked paragraphs in his copy of the preliminary report: {p. 52} "'There has been speculation that the aerial phenomena might actually be some form of penetration from another planet . . . the existence of intelligent life on Mars is not impossible but is completely unproven . . . the possibility of intelligent life on the Planet Venus is not considered completely unreasonable by astronomers . . . Scientists concede that living organisms might develop in chemical environments which are strange to us . . . in the next fifty years we will almost certainly start exploring space . . . the chance of space travelers existing at planets attached to neighboring stars is very much greater than the chance of space-traveling Martians. The one can be viewed as almost a certainty . . .'" DuBarry handed me the report. "Here--I practically know it by heart. Take it with you. You can send it back later." "I know the space-travel idea sounds silly at first," said Purdy, "but it's the only answer that explains all the sightings-especially those in the last century." He asked DuBarry to give me their file of historic reports. While John was getting it, Purdy went on: "Be careful about this man Steele. After what he said about 'moral responsibility' I'm sure he's planted." I thought back to Steele's warning. I told Purdy: "If he had the space thing in mind, maybe he's right. It could set off a panic that would make that Orson Welles thing look like a picnic." "Certainly it could," Purdy said. "We'd have to handle it carefully-if it turned out to be the truth. But I think the Air Force is making a mistake, if that's what they're hiding. It could break the wrong way and be serious." John DuBarry came back with the file of old reports. "It might interest you to know," he said, "that the Air Force checked all these old sightings too." The idea was still a difficult one for me to believe. "Those space-travel suggestions might be a trick," I said. "The Air Force may be hinting at that to hide the guided-missile secret." "Yes, but later on they deny the space thing," said Purdy. "It looks as if they're trying to put people on guard and then play it down, so they won't get scared." {p. 53} As I put the historic reports file in my brief case, Purdy handed me a letter from an investigator named Hilton, who had been working in the Southwest. I skimmed over his letter. Hilton had heard of some unusual night sightings in New Mexico. The story had been hushed up, but he had learned some details from a pilot at Albuquerque. One of these mysterious "flying lights" had been seen at Las Vegas, on December 8, 1948--just one month before Mantell was killed in Kentucky. It was too dark to make out the shape behind the light, but all witnesses had agreed on its performance. The thing had climbed at tremendous speed, its upward motion shown by a bright green light. Though the green glow was much brighter than a plane's running light, all plane schedules were carefully checked. "I think they were trying to pin it on a jet fighter," the Albuquerque pilot told Hilton. "But there weren't any jets near there. Anyway, the thing climbed too fast. It must have been making close to nine hundred miles an hour." The Air Force had also checked balloon release times--apparently just for the record, since no balloon could even approach the saucer's terrific ascent. Again, they drew a blank. "From the way this was hushed up," Hilton commented, "they seem to be worried about this group of sightings. I've heard two reports that the F.B.I. is tied into the deal somehow, but that's as far as I can get." "See if you can get any lead on that," Purdy told me. "That F.B.I. business puzzles me. Where would they come in?" I said I would try to find out. But it was almost four months before we learned the answer: The F.B.I. men had been witnesses. (This was later admitted in an obscure cross-reference in the final Project "Saucer" report. But all official answers to the strange green-light sightings had been carefully omitted. The cases concerned were 223, 224, 225, 226, 227, 230, and 231, which will be discussed later.) {p. 54} "When you go back to Washington," said Purdy, "see what reaction you get to the interplanetary idea." I had a pretty good idea what the reaction would be, but I nodded. "O.K. I'll go flag a space ship and be on my way." "O.K.--gag it up," said Purdy. "But don't sell it short, If by any chance it's true, it'll be the biggest story since the birth of Christ." {p. 55} CHAPTER VII IT WAS DARK when the airliner limousine reached La Guardia Field. I had intended taking an earlier plane, but DuBarry persuaded me to stay over for dinner. We dropped into the Algonquin, next door to True's office building. Halfway through dinner, I asked John what he thought of the space-travel answer. "Oh, it's possible," he said cautiously. "The time and space angles make it hard to take, but if we're planning to explore space within fifty years, there's no reason some other planet people couldn't do it. Of course, if they've been observing us for over a century, as those old sightings seem to indicate, they must be far ahead of us, at least in technical progress." Later on, he said thoughtfully, "Even though it's possible, I hate to think it's the answer. just imagine the impact on the world. We'd have to reorient our whole lives--and things are complicated enough already." Standing at the gate, waiting for my plane to be called, I thought over that angle. Assuming that space travel was the solution--which I still couldn't believe-what would be the effect on the world? It was a hard thing to picture. So much depended on the visitors from space. What would their purpose be? Would they be peaceful or hostile? Why had they been observing the earth so intensively in the past few years? I could think of a hundred questions. What would the space people be like? Would they be similar to men and women on earth, or some fearsome Buck Rogerish creatures who would terrify the average American--including myself? It was obvious they would be far superior to us in many ways. But their civilization might be entirely different. Evolution might have developed their minds, and possibly their bodies, along lines we couldn't even grasp. Perhaps we couldn't even communicate with them. What would be the net effect of making contact with beings from a distant planet? Would earthlings be terrified, {p. 56} or, if it seemed a peaceful exploration, would we bc intrigued by the thought of a great adventure? It would depend entirely on the space visitors' motives, and how the world was prepared for such a revelation. The more I thought about it, the more fantastic thc thing seemed. And yet it hadn't been too long since airplane flight was considered an idiot's dream. This scene here at La Guardia would have seemed pure fantasy in 1900--thc huge Constellations and DC-6's; the double-decked Stratocruisers, sweeping in from all over the country; the big ships at Pan-American, taking off for points all over the globe. We'd come a long way in the forty-six years since the Wright brothers' first flight. But space travel! The gateman checked my ticket, and I went out to the Washington plane. It was a luxury ship, a fifty-two-passenger, four-engined DC-6, scheduled to be in the capital one hour after take-off. By morning this plane, the Aztec, would be in Mexico City. The couple going up the gangway ahead of me were in their late sixties. Fifty years ago, what would they have said if someone had predicted this flight? The answer to that was easy; at that time, high-school songbooks featured a well-known piece entitled "Darius Green and His Flying Machine." Darius, it seems, was a simple-minded lad who actually thought he could fly. Fifty years. That was the time the Air Force had estimated it would take us to start exploring space. Would Americans come to accept space travel as matter-of-factly as the people now boarding this plane? The youngsters would, probably; the older ones, as a rule, would be a little more cautious. In the oval lounge at the rear of the plane, I took out the file of old sighting reports. Glancing through it, I, saw excerpts from nineteenth-century astronomical and scientific journals and extracts from official gazettes. Most of the early sightings had been in Great Britain and on the Continent, with a few reports scattered around the world. The American reports did not begin until the latter part of the century. {p. 57} The DC-6 rolled out and took off. For a few minutes I watched the lights of Manhattan and Greater New York twinkling below. The Empire State Building tower was still above us, as the plane banked over the East River. We climbed quickly, and the familiar outline of Manhattan took shape like a map pin-pointed with millions of lights. Any large city seen from the air at night has a certain magic, New York most of all. Looking down, I thought: What would a spaceman think, seeing this brilliantly lighted city, the towering skyscrapers? Would other planets have such cities, or would it be something new and puzzling to a visitor from space? Turning back to the old reports, I skipped through until I found the American sightings. One of the first was an incident at Bonham, Texas, in the summer of 1873. It was broad daylight when a strange, fast-moving object appeared in the sky, southwest of the town. For a moment, the people of Bonham stared at the thing, not believing their eves. The only flying device then known was the drifting balloon. But this thing was tremendous, and speeding so fast its outlines were almost a blur. Terrified farmers dived under their wagons. Townspeople fled indoors. Only a few hardy souls remained in the streets. The mysterious object circled Bonham twice, then raced off to the cast and vanished. Descriptions of the strange machine varied from round or oval to cigar-shaped. (The details of the Bonham sighting were later confirmed for me by Frank Edwards, Mutual network newscaster, who investigated this case.) Twenty-four hours after the Bonham incident, a device of the same description appeared at Fort Scott, Kansas. Panic-stricken soldiers fled the parade ground as the thing flashed overhead. In a few seconds it disappeared, circling toward the north. Until now, I had supposed that the term "saucer" was original with Kenneth Arnold. Actually, the first to compare a flying object with a saucer was John Martin, a farmer who lived near Denison, Texas. The Denison Daily News of January 25, 1878, gives the following account: {p. 58} From Mr. John Martin, a farmer who lives some six miles south of this city, we learn the following strange story: Tuesday morning while out hunting, his attention was directed to a dark object high up in the southern sky. The peculiar shape and velocity with which the object seemed to approach riveted his attention and he strained his eves to discover its character. When first noticed, it appeared to be about the size of an orange, which continued to grow in size. After gazing at it for some time Mr. Martin became blind from long looking and left off viewing it for a time in order to rest his eyes. On resuming his view, the object was almost overhead and had increased considerably in size, and appeared to be going through space at wonderful speed. When directly over him it was about the size of a large saucer and was evidently at great height. Mr. Martin thought it resembled, as well as he could judge, a balloon. It went as rapidly as it had come and was soon lost to sight in the heavenly skies. Mr. Martin is a gentleman of undoubted veracity and this strange occurrence, if it was not a balloon, deserves the attention of our scientists. In the file, I saw a memo DuBarry had written: "I would take the very early reports with caution. For instance, the one on August 9, 1762, which describes an odd, spindle-shaped body traveling at high speed toward the sun. I recall that Charles Fort accepted this, along with other early sightings, as evidence of space ships. But this particular thing might have been a meteor--meteors as such were almost unknown then. The later reports are more convincing, and it is also easier to check the sources, especially those from 1870 on." From 1762 to 1870, the reports were meager. Some described mysterious lights in the sky; a few mentioned round objects seen in daylight. Even though they were not so fully documented as later ones, one point struck me. In those days, there was no telegraph, telephone, or radio to spread news rapidly and start a flood of rumors. {p. 59} A sighting in Scotland could not be the cause of a similar one two days later in the south of France. Beginning in 870, there was a series of reports that went on to the turn of the century. In the London Times, September 26, 1870, there was a description of a queer object that was seen crossing the moon. It was reported as elliptical, with some kind of tail, and it took almost thirty seconds to complete its passage of the moon. Then in 1871, a large, round body was sighted above Marseilles, France. This was on August 1. It moved slowly across the sky, apparently at great height, and was visible about fifteen minutes. On March 22, 1880, several brilliantly luminous objects were reported seen at Kattenau, Germany. Sighted just before sunrise, they were described as rising from the horizon and moving from east to west. The account was published in the British Nature Magazine, Volume 22, page 64. The next report in the file mentioned briefly a strange round object seen in the skies over Bermuda. The source for this account was the Bermuda Royal Gazette. This was in 1885. That same year, an astronomer and other witnesses reported a gigantic aerial object at Adrianople, Turkey. On November 1, the weird apparition was seen moving across the sky. Observers described it as round and four to five times the size of the moon. This estimate is similar to the Denison, Texas, comparison with an orange. The object would actually be huge to be seen at any great height. But unless the true height were known, any estimate of size would be guesswork. On March 19, 1887, two strange objects fell into the sea near a Dutch barkentine. As described by the skipper, Captain C. D. Sweet, one of the objects was dark, the other brightly luminous. The glowing object fell with a loud roaring sound; the shipmaster was positive it was not a meteor. In New Zealand, a year later, an oval-shaped disk was reported speeding high overhead. This was on May 4, 1888. About two years after this, several large aerial bodies were sighted hovering over the Dutch East Indies. {p. 60} Most accounts described them as roughly triangular, about one hundred feet on the base and two hundred feet on the sides. But some observers thought they might be longer and narrower, with a rounded base; this would make them agree with more recent stories of cone-shaped objects with rounded tops seen in American skies. On August 26, 1894, a British admiral reported sighting a large disk with a projection like a tail. And a year after this, both England and Scotland buzzed with stories of triangular-shaped objects like those seen in the Dutch East Indies. Although many officials scoffed at the stories, more than one astronomer stuck to his belief that the mysterious things might be coming from outer space. Since planes and dirigibles were then unknown, there was no one on earth who could have been responsible for them. In 1897, sightings in the United States began to be more frequent. One of the strangest reports describes an incident that began on April 9. Flying at a great height, a huge cigar-shaped device was seen in the Midwest. Short wings projected from the sides of the object, according to reports of astronomers who watched it through telescopes. For almost a week, the aerial visitor was sighted around the Midwest, as far south as St. Louis and as far west as Colorado. Several times, red, green, and white lights were seen to flash in the sky; some witnesses thought the crew of this strange craft might be trying to signal the earth. On April 16, the thing, whatever it was, disappeared from the Midwest. But on April 19, the same object--or else a similar one--appeared over West Virginia. Early that morning the town of Sisterville was awakened by blasts of the sawmill whistle. Those who went outside their homes saw a strange sight. From a torpedo-shaped object overhead, dazzling searchlights were pointing downward, sweeping the countryside. The thing appeared to be about two hundred feet long, some thirty feet in diameter, with stubby wings and red and green lights along the sides. For almost ten minutes the aerial visitor circled the town, then it swung eastward and vanished. The next report was published in the U.S. Weather Bureau's monthly Weather Review. On page 115 in the {p. 61} March 1904 issue, there is an account of an odd sighting at sea. On February 24, 1904, a mysterious light had been seen above the Atlantic by crew members of the U.S.S. Supply. It was moving swiftly, and evidently at high altitude. The report was attested by Lieutenant Frank H. Schofield, U.S.N. On July 2, 1907, a mysterious explosion occurred, in the heavens near Burlington, Vermont. Some witnesses described a strange, torpedo-shaped device circling above. Shortly after it was seen, a round, luminous object flashed down from the sky, then exploded, (Weather Review, 1907, page 310.) Another cigar-shaped craft was reported at a low altitude over Bridgewater, Massachusetts, in 1905. Like the one at Sisterville, it carried searchlights, which swept back and forth across the countryside. After a few moments, the visitor rose in a steep climb, and the searchlights blinked out. There was no report for 1909 in America, though an odd aerial object was sighted near the Galapagos Islands. But in 1910, one January morning, a large silvery cigar-shaped device startled Chattanooga. After about five minutes, the thing sped away, appearing over Huntsville, Alabama, shortly afterward. It made a second appearance over Chattanooga the next day, then headed east and was never seen again. In Popular Astronomy, January 27, 1012, a Dr. F. B. Harris described an intensely black object that he saw crossing the moon. As nearly as he could tell, it was gigantic in size--though again there was no way to be sure of its distance from him or the moon. With careful understatement, Dr. Harris said, "I think a very interesting and curious phenomenon happened that night." A strange shadow was noted on the clouds at Fort Worth, Texas, on April 8, 19, 3. It appeared to be caused by some large body hovering motionless above the clouds. As the cloud layer moved, the shadow remained in the same position. Then it changed size, diminishing, and quickly disappeared, as if it had risen vertically. A report on this was given in the Weather Bureau Review of that year, Number 4-599 {p. 62} By 1919, dirigibles were of course well known to most of the world. When a dirigible-shaped object appeared over Huntington, West Virginia, in July of that year, there was no great alarm. It was believed to be an American blimp, though the darkness--it was eleven at night--prevented observers from being sure. But a later check-up proved it was not an American ship, nor was it from any country possessing such craft. For some time after this, there were few authentic reports. Then in 1934, Nicholas Roerich, head of the American-Roerich expedition into Tibet, had a remarkable experience that bears on the saucer riddle. On pages 361 and 362 of his book Altai Himalaya, Roerich describes the incident. The expedition party was in the wilds of Tibet one morning when a porter noticed the peculiar actions of a buzzard overhead. He called Roerich's attention to it; then they all saw something high in the sky, moving at great speed from north to south. Watching it through binoculars, Roerich saw it was oval-shaped, obviously of huge size, and reflecting the sun's rays like brightly polished metal. While he trailed it with his glasses, the object suddenly changed direction, from south to southwest. It was gone in a few moments. This was the last sighting listed before World War II. When I had finished, I stared out the plane window, curiously disturbed. Like most people, I had grown up believing the earth was the center of everything--life, intelligence, and religion. Now, for the first time in my life, that belief was shaken. It was a curious thing. I could accept the idea that we would eventually explore space, land on the moon, and go on to distant planets. I had read of the plans, and I knew our engineers and scientists would somehow find a way. It did not disturb my belief in our superiority. But faced with this evidence of a superior race in the universe, my mind rebelled. For years, I had been accustomed to thinking in comic-strip terms of any possible spacemen--Buck Rogers stuff, with weird-looking space ships and green-faced Martians. But now, if these sightings were true, the shoe was on the other foot. We would be faced with a race of beings {p. 63} at least two hundred years ahead of our civilization--perhaps thousands. In their eyes, we might look like primitives. My conjectures before the take-off had just been idle thinking; I had not really believed this could be the answer. But now the question came back sharply. How would we react to a sudden appearance of space ships, bringing that higher race to the earth? If we were fully prepared, educated to this tremendous adventure, it might come off without trouble. Unprepared, we would be thrown into panic. The lights of Philadelphia showed up ahead, and a thought struck me. What would Philadelphians of 1776 have thought to see this DC-6 flying across their city at three hundred miles an hour? What would the sentries at Valley Forge have done, a year later, if this lighted airliner had streaked over their heads? Madness. Stampede. Those were the plain answers. But there was a difference now. We had had modern miracles, radio, television, supersonic planes, and the promise of still more miracles. We could be educated, or at least partly prepared, to accept space visitors. In fifty years we had learned to fly. In fifty years more, we would be exploring space. Why should we believe such creative intelligence was limited to the earth? It would be incredible if the earth, out of all the millions of planets, proved the only inhabited spot in the whole universe. But, instinctively, I still fought against believing that the flying saucers were space ships. Eventually, we would make contact with races on other planets; they undoubtedly would someday visit the earth. But if it could be put off . . . a problem for later generations to handle . . . If the disks proved American guided missiles, it would be an easier answer. Looking through the Project "Saucer" report DuBarry had loaned me, I read the space-travel items, hoping to find some hint that this was a smoke screen. On page 18, in a discussion on Mars, I found this comment: "Reports of strange objects seen in the skies have been handed down through the generations. However, scientists believe that if Martians were now visiting the earth {p. 64} without establishing contact, it could be assumed that they have just recently succeeded in space travel, and that their civilization would be practically abreast of ours. This because they find it hard to believe that any technically established race would come here, flaunt its ability in mysterious ways over the years, but each time simply go way without ever establishing contact." There could be several answers to that. The Martians might not be able to live in our atmosphere, except in their sealed space ships. They, or some other planet race, could have observed us periodically to check on our slow progress. Until we began to approach their level of civilization, or in some way caused them concern, they would probably see no reason for trying to make contact. But somehow I found a vague comfort in the argument, full of holes though it was. Searching further, I found other space-travel comments. On one page, the Air Force admitted it was almost a certainty that space travelers would be operating from planets outside the solar system. But on the following page, I discovered this sentence: "Thus, although visits from outer space are believed to be possible, they are thought to be highly improbable." What was the answer? Was this just a wandering discussion of possibilities, badly put together, or was it a hint of the truth? it could be the first step in preparing America for a revelation. It could also be a carefully thought-out trick. This whole report might be designed to conceal a secret weapon. If the Air Force or the Navy did have a secret missile, what better way to distract attention? The old sighting reports could have been seized on as a buildup for space travel hints. Then suddenly it hit me. Even if it were a smoke screen, what of those old reports? They still remained to be answered. There was only one possible explanation, unless you discarded the sightings as lies. That meant discrediting many reliable witnesses--naval officers, merchant shipmasters, explorers, astronomers, ministers, and responsible public officials. {p. 65} Besides all these, there had been thousands of other witnesses, where large groups had seen the objects. The answer seemed inevitable, but I held it off. I didn't want to believe it, with all the changes it might bring, the unpredictable effect upon our civilization. If I kept on checking I might find evidence that would bring a different explanation for the present saucers. DuBarry had put another group of reports in the envelope; this series covered the World War II phase and on up to the outbreak of the saucer scare in the United States. Some of it, about the foo fighters, I already knew. This was tied in with the mystery rockets reported over Sweden. The first Swedish sightings had occurred during the early part of the war. Most of the so-called "ghost rockets" were seen at night, moving at tremendous speed. Since they came from the direction of Germany, most Swedes believed that guided rockets were the answer. During the summer of 1946, after the Russians had taken over Peenemunde, the Nazi missile test base, ghost rockets again were reported flying over Sweden. Some were said to double back and fly into Soviet areas. Practically all were seen at night, and therefore none had been described as a flying disk. Instead, they were said to be colored lights, red, green, blue, and orange, often blurred from their high speed. But there was a puzzling complication. Mystery lights, and sometimes flying disks, were simultaneously reported over Greece, Portugal, Turkey, Spain, and even French Morocco. Either there were two answers, or some nation had developed missiles with an incredibly long range. By January 1947, ghost-rocket sightings in Europe had diminished to less than one a month. Oddly enough, the first disk report admitted by Project "Saucer" was in this same month. The first '47 case detailed by Project "Saucer" occurred at Richmond, Virginia. It was about the middle of April. A Richmond weather observer had released a balloon and was tracking it with a theodolite when a strange object crossed his field of vision. He swung the theodolite and managed to track the thing, despite its high speed. (The actual speed and altitude--the latter determined by a comparison of the balloon's height at {p. 66} various times--have never been released. Nor has the Air Force released this observer's report on the object's size, which Project "Saucer" admitted was more accurate than most witnesses' estimates.) About the seventeenth of May 1947, a huge oval-shaped saucer ten times longer than its diameter was sighted by Byron Savage, an Oklahoma City pilot. Two days later, another fast-flying saucer was reported at Manitou Springs, Colorado. In the short time it was observed, it was seen to change direction twice, maneuvering at an unbelievable speed. Then on June 24 came Kenneth Arnold's famous report, which set off the saucer scare. The rest of the story I now knew almost by heart. When the DC-6 landed at Washington, I had made one decision. Since it was impossible to check up on most of the old sightings, I would concentrate on certain recent reports--cases in which the objects had been described as space ships. As I waited for a taxi, I looked up at the sky. It was a clear summer night, without a single cloud. Beyond the low hill to the west I could see the stars. I can still remember thinking, If it's true, then the stars will never again seem the same. {p. 67} CHAPTER VIII NEXT MORNING, in the broad light of day, the idea of space visitors somehow had lost its menace. If the disks were space ships, at least they had shown no sign of hostility, so far as I knew. Of course, there was Mantell; but if he had been downed by some weapon on the disk, it could have been self-defense. In most cases, the saucers retreated at the first sign of pursuit. My mind was still reluctant to accept the space-travel answer, in spite of the old reports. But I kept thinking of the famous aircraft designer who thought the disks were space craft; the airline pilots Purdy had mentioned; Blake's copilot, Chuck. . . . Now that I recalled it, Blake had been more embarrassed than seemed called for when he told about Chuck. Perhaps he had been the one who believed the saucers were space ships, instead of his absent copilot. After breakfast, I went over the list of sightings since June 1947. There were several saucers that actually had been described as projectile-like ships. The most famous of all was the Eastern Airlines case. It was 8:30 P.M., July 23, 1948, when an Eastern Airlines DC-3 took off from Houston, Texas, on a flight to Atlanta and Boston. The airliner captain was Clarence S. Chiles. During the war, he had been in the Air Transport Command, with the rank of lieutenant colonel. He had 8,500 flying hours. His first officer was John B. Whitted, a wartime pilot on B-29's. Both men were known in Eastern as careful, conservative pilots. It was a bright, moonlit night, with scattered clouds overhead. The DC-3 was twenty miles west of Montgomery, at 2:45 A.M., when a brilliant projectile-like craft came hurtling along the airway. Chiles saw it first and took it to be a jet plane. But the next instant both pilots saw that this was no jet fighter. "It was heading southwest," Chiles said later, "exactly opposite to our course. Whatever it was, it flashed down toward us at terrific speed. We veered to the left. It veered {p. 68} sharply, too, and passed us about seven hundred feet to the right. I saw then that it had no wings." The mystery ship passed on Whitted's side, and he had a fairly close look. "The thing was about one hundred feet long, cigar-shaped, and wingless," he described it. "It was about twice the diameter of a B-twenty-nine, with no protruding fins." Captain Chiles said the cabin appeared like a pilot compartment, except for its eerie brilliance. Both he and Whitted agreed it was as bright as a magnesium flare. They saw no occupants, but at their speed this was not. surprising. "An intense dark-blue glow came from the side of the ship," Chiles reported. (It was later suggested by engineers that the strange glare could have come from a power plant of unusual type.) "It ran the entire length of the fuselage--like a blue fluorescent light. The exhaust was a red-orange flame, with a lighter color predominant around the outer edges." Both pilots said the flame extended thirty to fifty feet behind the ship. As it passed, Chiles noted a snout like a radar pole. Both he and Whitted glimpsed two rows of windows. "Just as it went by," said Chiles, "the pilot pulled up as if he had seen the DC-three and wanted to avoid its. There was a tremendous burst of flame from the rear. It zoomed into the clouds, its jet wash rocking our DC-three." Chiles's estimate of the mystery ship's speed was between five hundred and seven hundred miles an hour. As the object vanished, Chiles went back into the cabin to check with the passengers. Most had been asleep or were drowsing. But one man confirmed that they were in their right senses. This passenger, Clarence McKelvie of Columbus, Ohio, told them (and a Project "Saucer" team later) that he had seen a brilliant streak of light flash past his window. It had gone too swiftly for him to catch any details. The A.P. interviewed Mr. McKelvie soon after he landed, and ran the following story: {p. 69} "Kennett Square, Pa., July 24 (AP) . Clarence L. McKelvie, assistant managing editor of the American Education Press, said he was the only passenger on the EAL Houston-Boston plane who was not asleep when the phantom craft was sighted. "'I saw no shape or form,' Mr. McKelvie said. 'I was on the right side of the plane, and suddenly I saw this strange eerie streak out of my window. It was very intense, not like lightning or anything I had ever seen.' "The Columbus man said he was too startled and the object moved too quickly for him to adjust his eyes to it." In Washington, Air Force officials insisted they could shed no light on the mystery. Out in Santa Monica, General George C. Kenney, then chief of the Strategic Air Command, declared the Air Force had nothing remotely like the ship described. "I wish we did," General Kenney told reporters. "I'd sure like to see that." The publicized story of this "space ship" set off another scare--also the usual cracks about screwball pilots. But Chiles and Whitted were not screwballs; they were highly respected pilots. The passenger's confirmation added weight. But even if all three had been considered deluded, the Air Force investigators could not get around the reports from Robbins Air Force Base. Just about one hour before the DC-3 incident, a strange flaming object came racing southward through the night skies over Robbins Field, at Macon, Georgia. Observers at the air base were astounded to see what appeared to be a huge, wingless craft streak overhead, trailing a varicolored exhaust. (The witnesses' description tallied with those of Chiles and Whitted.) The mystery ship vanished swiftly; all observers agreed that it disappeared from the line of sight just like a normal aircraft. While I was working on this case, a contact in Washington gave me an interesting tip. "Within forty-eight hours after that Eastern sighting, Air Force engineers rushed out blueprint plans and elevations of the 'space ship,' based on what the two pilots told them." Whether or not this was true, I found that the Air {p. 70} Force engineers did compute the probable speed and lift of the mystery craft. The ship was found to be within the bounds of aerodynamic laws for operations in our atmosphere. Here is the Air Force statement: "Application of the Prandtl theory of lift indicated that a fuselage of the dimensions reported by Chiles and Whitted could support a load comparable to the weight of an aircraft of this size, at flying speeds in the sub-sonic range." (This supports Chiles's estimate of 500-700 m.p.h.) Four days after the space-ship story was published, a Navy spokesman was quoted as hinting it might have been a high-atmosphere rocket gone astray from the proving grounds in New Mexico. The brief report appeared on the editorial page of the Washington Star on July 28, 1947. It ran as follows: "The Navy says that naval technicians have been testing a 3,000-mile-per-hour rocket in New Mexico. If one went astray, it could travel across our continent in a short time." At first glance I thought this might be the real answer to the Chiles-Whitted case. But after a few minutes I saw it was almost impossible. First, rockets at White Sands are launched and controlled with utmost care. There have been no reported cases of such a long-distance runaway. Second, if such a rocket had gone astray, it would certainly have caused wild confusion at White Sands until they found where it landed. Hundreds of people would have known about it; the story would be certain to leak out. Third, such a rocket would have had to travel from White Sands to Macon, Georgia, then circle around south of this city for over forty minutes. (If it had kept on at the speed observed at Robbins Field, it would have passed Montgomery long before the DC-3 reached the area.) In addition, the rocket would have had to veer sharply away from the airliner, as both pilots testified, and then zoom into the clouds. No high-atmosphere test rocket has automatic controls such as this would require. {p. 71} And if it had gone astray from White Sands, the station's remote control would no longer be guiding it. The Eastern Airlines "space ship," then, was not just a fugitive rocket. But it could be a new type of aircraft, something revolutionary, developed in absolute secrecy. Other airline pilots had reported flying disks racing along the airways, though none that I knew of had described projectile-like objects. Chiles and Whitted insisted the mystery ship was not a disk, and the report from Robbins Field agreed on this point. Man-made devices or not, it seemed fairly certain there was more than one type of saucer. The more I studied the evidence, the harder it was to believe that this was an earth-made ship. Such a wingless rocket ship would require tremendous jet power to keep it in the air. Even our latest jet bombers could not begin to approach its performance. Going back over the Project "Saucer" preliminary report, I found strong evidence that the Air Force was worried. In their investigation, Project teams had screened 225 military and civilian flight schedules. After nine months, they reported that the mysterious object was no conventional aircraft. On April 27, 1949, the Air Force admitted that Project "Saucer" had failed to find the answer. The "space ship" was officially listed as unidentified. "But Wright Field is still working on it," an Air Force officer told me. "Both Chiles and Whitted are responsible pilots, and McKelvie has a reputation for making careful statements. Even without the Robbins Field confirmation, no one could doubt that they saw something." The Chiles-Whitted "space ship" was not the first of this type to be reported. Another wingless aircraft was sighted in August 1947, by two pilots for an Alabama flying service. It was at Bethel, Alabama, just after sunset, when a huge black wingless craft swept across their course. Silhouetted against the evening sky, it loomed larger than a C-54. The pilots saw no wings, motors, or jet exhausts. Swinging in behind the mystery ship, they attempted to follow. But at their speed of 170 m.p.h. they were quickly outdistanced. Careful checking showed there were no {p. 72} other planes nearby that could have been mistaken for this strange craft. On New Year's Day, 1948, a similar rocket-shaped object was sighted at Jackson, Mississippi. It was first seen by a former Air Force pilot and his passenger, and later by witnesses on the ground. Before the pilot could begin to close in, the odd wingless ship pulled away. Speeding up from 200 to 500 m.p.h., it swiftly disappeared. Besides these two cases, already on record, I had the tips Purdy had given me. One wingless ship was supposed to have been seen three or four days before the Chiles-Whitted sighting; like the thing they reported, the unidentified craft was a double-decked "space ship" but moving at even higher speed. At first I ran into a stone wall trying to check this story. Then I found a lead conforming that this was a foreign report. It finally proved to be from The Hague. The tip had been right. This double-decked, wingless ship had been sighted on July 20, 1948--four days before the Eastern case. Witnesses had reported it at a high altitude, moving at fantastic speed. While working on this report, I verified another tip. We had heard a rumor of a space-ship sighting at Clark Field, in the Philippine Islands. Although I didn't learn the date, I found that there was such a record. (In the final Project "Saucer" report, the attempt to explain away this sighting was painfully evident. Analyzing this case, Number 206, the Air Force said: "If the facts are correct, there is no astronomical explanation. A few points favor the daytime meteor hypothesis--snow-white color, speed faster than a jet, the roar, similarity to sky-writing and the time of day. But the tactics, if really performed, oppose it strenuously: the maneuvers in and out of cloud banks, turns of 180 degrees or more, Possibly these were illusions, caused by seeing the object intermittently through clouds. The impression of a fuselage with windows could even more easily have been a sign of imagination." (With this conjecture, Project "Saucer" listed the sighting as officially answered. The Hague space-ship case was unexplained.) {p. 73} In following up the Jackson and Bethel reports, I talked with two officials in the Civil Aeronautics Administration. One of these was Charley Planck, who handled public relations. I found that the pilots concerned had good records; C.A.A. men who knew them discounted the hoax theory. "Charley, there's a rumor that airline pilots have been ordered not to talk," I told Planck. "You know anything about it?" "You mean ordered by the Air Force or the companies?" he said. "The Air Force and the C.A.A." "If the C.A.A.'s in on it, it's a top-level deal," said Charley. "I think it's more likely the companies--with or without a nudge from the Air Force." While we were talking, an official from another agency came in. Because the lead he gave me was off the record, I'll call him Steve Barrett. I knew Steve fairly well. We were both pilots with service training; our paths had crossed during the war, and I saw him now and then at airports around Washington. When the saucer scare first broke, Steve had been disgusted. "Damn fools trying to get publicity," he snorted. "The way Americans fall for a gag! Even the Air Force has got the jitters." So I was a little surprised to find he now thought the disks were real. "What sold you?" I asked. "The radar reports," said Steve. "I know of half a dozen cases where they've tracked the things. One was in Japan. The thing was climbing so fast no one believed the radarmen at first. Then they got some more reports. One was up in Canada. There was a case in New Mexico, and I think a Navy destroyer tracked a saucer up in the North Atlantic." "What did they find out?" said Charley Planck. Steve shrugged. "I don't know all the answers. Whatever they are, the things can go like hell." I had a hunch he was holding back. I waited until he had finished with Charley, and then went, down the hall with him. {p. 74} "You think the saucers are guided missiles?" I said. "If I thought so, I wouldn't be talking," he said flatly, "That's not a dig at you. But I was cleared last year for some secret electronics work, and it might be used in some way with guided missiles." "I didn't know that, Steve." "It's O.K.," he said. "I don't mind talking, because can't believe the saucers are guided missiles. Maybe few of the things sighted out in the Southwest have beer our test rockets, but that doesn't explain the radar reports in Canada and Japan." "I'd already heard about a radar case in Labrador," I told Steve. He looked at me quickly. "Where'd you pick that up;" "True passed it on to me," I said. "They've had some trouble tracking the things, they maneuver so fast," said Steve. "It sounds crazy, but I've been told they hit more than ten thousand miles an hour." "You believe it.?" "Well, it's not impossible. Those saucers were tracked about fifty miles up, where there's not much resistance." The elevator door opened. Steve waited until we were outside of the Commerce Building. "There's one other thing that gets me," he said. "Unless the radar boys are way off, some of those saucers are enormous. I just can't see a guided missile five hundred feet in diameter." He stopped for a moment. "I suppose this will sound screwy to you--" "You think they're interplanetary," I said. Steve was quickly on the defensive. "I haven't bought it yet, but it's not as crazy as it sounds." Without mentioning names, I told him about the aircraft designer and the airline pilots. "They're in good company," said Steve. "You know the Air Institute?" "Sure--the Air Force school down at Montgomery." "Six months ago, I was talking with an officer who'd been instructing there." Steve looked at me, deadly serious. "He told me they are now teaching that the saucers are probably space ships." {p. 75} CHAPTER IX THREE DAYS after my meeting with Steve Barrett, I was on a Mainliner 300, starting, a new phase of the saucer investigation. By the time I returned, I hoped to know the truth about Project "Saucer." As the ship droned westward, fourteen thousand feet above the Alleghenies, I thought of what Steve had told me. I believed, that he had told me about the radar tracking. And I was fairly sure he believed the Air Institute story. But I wasn't so certain the story itself was true. It would hardly be a gag; Steve wasn't easily taken in. It was more likely that one Institute officer, or perhaps several, believed the saucers were space craft and aired their personal opinions. The Institute wasn't likely to give an official answer to something that Project "Saucer" still declared unsolved. If it were possible to get an inside look at Project "Saucer" operations, I could soon tell whether it was an actual investigation or a deliberate cover-up for something else. Whichever it was, the wall of official. secrecy still hid it. As a formality, I had called the Pentagon again and asked to talk with some of the Project officers. As I expected, I was turned down. The only alternative was to dig out the story by talking with pilots and others who had been. quizzed by Project teams. I had several leads, and True had arranged some interviews for me. My first stop was Chicago, where I met an airline official and two commercial pilots. I saw the pilots first. Since they both talked in confidence, I will not use their right names. One, a Midwesterner I already knew, I'll call Pete Farrell; the other, a wartime instructor, Art Green. Pete was about thirty-one, stocky, blue-eyed, with a pleasant, intelligent face. Art Green was a little older, a lean, sunburned, restless man with an emphatic voice. Pete had served with the Air Force during the war; he {p. 76} was now part owner of a flying school, also a pilot in the Air National Guard. Green was working for an air charter service We met at the Palmer House. Art Green didn't need much prompting to talk about Project "Saucer." After reporting a disk, seen during a West Coast Right, he had been thoroughly grilled by a Project "Saucer" team. "They practically took me apart," he said irritably. "They've got a lot of trick questions. Some of 'em are figured out to trip up anybody faking a story. The way they worked on me, you'd think I committed a murder. "Then they tried to sell me on the idea I'd seen a balloon, or maybe a plane, with the sun shining on it when it banked. I told them to go to the devil--I knew what I saw. After seventeen years, I've got enough sense to tell a ship or a balloon when I see it." "Did they believe you?" I asked him. "If they did, they didn't let on. Two of 'em acted as if they thought I was nuts. The other guy-I think he was Air Force Intelligence--acted decent. He said not to get steamed up about the Aero-Medical boys; it was their job to screen out the crackpots. "And on top of that, I found out later the F.B.I. had checked up on me to find out if I was a liar or a screwball. They went around to my boss, people in my neighborhood--even the pilots in my outfit. My outfit's still razzing me. I wouldn't report another saucer if one flew through my cockpit." Pete Farrell hadn't encountered any Project "Saucer" teams personally, but he had some interesting angles. Some of the information had come from commercial and private pilots in the Midwest, part of it through National Guard contacts. "I can tell you one thing," Pete said. "Guard pilots got the same order as the Air Force. If we saw anything peculiar flying around, we were to do our damnedest to identify it." "What about trying to bring one down? I've heard that was in one order." Pete hesitated for a second. "Look, I told you that much because it's been in the papers. But I'm still in the {p. 77} Guard. I can't tell you the order itself. It was confidential." "Well, I'm not in the Guard," said Art Green. He lit a cigarette, blew out the match. "Why don't you look into the Gorman case? Get thc dope on that court-martial angle." I'd heard of the Gorman case, but the court-martial thing was new to me. Gorman, I recalled, was a fighter pilot in the North Dakota Air National Guard. He had a mystifying encounter with a strange, fast-moving "light" over Fargo Airport in the fall of 1948. "That case is on my list," I told Green. "But I don't remember anything about a court-martial." "It wasn't in the papers. But all the pilots up that way know about it. In his report, Gorman said something about trying to ram the thing. The idea got around that Air Force orders had said to try this. Anyway, it got into the papers and Gorman almost got court-martialed. If his family hadn't had some influence in the state, the Air Force probably would have pushed it." "Are you sure about this?" I said. "You know how those things build up." "Ask Gorman," he said. "Or ask some of the pilots at Fargo." Before I left them, Green double-checked my report on his sighting, which Hilton had forwarded. As in the majority of cases, he had seen just one disk. It had hovered at a very high altitude, gleaming in the sun, then had suddenly accelerated and raced off to the north. "I couldn't tell its size or speed," said Green. "But if it was as high as I think, it must have been pretty big." Pete told me later that Green believed the disk had been at least twenty miles high, because it was well above clouds at thirty thousand feet. "It's kind of hard to believe," said Pete. "The thing would have to be a lot bigger than a B-twenty-nine, and the speed over two thousand miles an hour." "You know what they said about the Mantell saucer," I reminded him. "Some of the Godman Field people said it was at least three hundred feet in diameter." "I've heard it was twice that," said Pete. {p. 78} "You know any Kentucky National Guard pilots?" I asked. "One or two," said Pete. "But they couldn't tell me anything. It was hushed up too fast." That evening I talked with the airline official, whom I knew well enough to call by his first name. I put it to him bluntly. "Dick, if you're under orders not to talk, just tell me. Fm trying to find out whether Project 'Saucer' has muzzled airline pilots." "You mean the ones who've sighted things? Perhaps, in a few cases. But most of the pilots know what happened to Captain Emil Smith, on United, and those Eastern pilots. They keep still so they won't be laughed at. Also the airlines don't like their pilots to talk for publication." "I've heard of several cases," I said, "where Air Force Intelligence is supposed to have warned pilots to keep mum. Two of the reports come pretty straight." He made a gesture. "That could be. I'm not denying that airline pilots--and that includes ours--see these things all the time. They've been sighted on the Seattle-Alaska route, and between Anchorage and Japan. I know of several saucers that pilots have seen between Honolulu and the mainland. Check with Pan-American--you'll find their pilots have seen them, too." "What happens to those reports?" "They go to Operations," said Dick. "Of course, if something really important happens, the pilot may radio the tower before he lands. Then the C.A.A. gets word to the Air Force, and they rush some Intelligence officers to quiz the pilots. if it's not too hot, they'd come from Wright Field--regular Project 'Saucer' teams. Otherwise, they'd send the nearest Intelligence officers to take over temporarily." I asked him if he had ever been in on one of thee sessions. Dick said he hadn't. "But a couple of pilots talked to me later. They said these Air Force men seemed quite upset about it; they pounced on everything these boys said about the thing's appearance--how it maneuvered and so on." {p. 79} "What do your pilots think the saucers are?" Dick gave me a slightly ironic grin. "Why ask me? Captain Blake says you've been getting it firsthand." "I wasn't pulling a fast one," I protested. "We're not going to quote actual names or sources, unless people. O.K. it." "Sure, I know that," said Dick. "But you've got thc answer already. Some pilots say interplanetary, some say guided missiles. A few--a very few--still think it's all nonsense, because they haven't seen any." "What do you think?" "I don't know the answer," said Dick, "but I'm positive of one thing. Either the Air Force is sitting on a big secret, or they're badly scared because they don't know the answer." During the next week or so, I covered several northwest and mountain states. Although I was chiefly trying to find out about Project "Saucer," I ran onto two sightings that were not on my list. One of these had occurred in California, at Fairfield Suisan Air Force Base. A Seattle man who had been stationed there gave me the details. It was on the night of December 1918, with unusually high winds sweeping across the airfield. At times the gusts reached almost seventy miles an hour. Suddenly a weird ball of light flashed into view, at a height of a thousand feet. As the men on the base watched it, astonished, the mysterious light abruptly shot skyward. In an incredibly short time, it reached an altitude of twenty thousand feet and vanished. "Was there any shape outlined behind the light?" I asked the Seattle man. "Nobody saw any," he replied. "It looked just like I said--a ball of light, going like a streak." "Did it leave any smoke behind it?" "You mean like an engine, or a jet?" He shook his head. "Not a thing. And it didn't make a sound--even when it shot up like that." "Did you hear any guesses about it, or reports later on?" "Some major who didn't see it said it must have been {p. 80} a balloon. Anybody with brains could see that was screwy. No balloon ever went up that fast--and besides, the thing was going against the wind." The second incident occurred at Salmon Dam, Idaho, on August 13, 1947. When I heard the date, it sounded familiar. I checked my sightings file and saw it was the same day as the strange affair at Twin Falls, Idaho. In the Twin Falls case, the disk was sighted by observers in a canyon. There was one interesting difference from the usual description. This disk was sky-blue, or else its gleaming surface somehow reflected the sky because of the angle of vision. Although it was not close to the treetops, the observers were amazed to see the trees whip violently when the disk raced overhead, as though the air was boiling from the object's swift passage. At Salmon Dam, that same day, two miners heard an odd roaring sound and stared into the sky. Several miles away, two brightly gleaming disks were circling at high speed. "It was like two round mirrors whirling around the sky," one of the men was later quoted as saying. "They couldn't have been any ordinary planes; not round like that. And they were going too fast." During this part of my trip, I also was told that one saucer had fallen into a mountain lake. This came to me secondhand. The lone witness was said to have rushed over to his car to get his camera as the disk approached. When it plunged toward the lake, he was so startled that he failed to snap the picture until the moment it struck. This story sounded so flimsy that I didn't bother to list it. Months later, a Washington newsman confirmed at least part of the lake story. When he first related it, I thought he had fallen for a gag. "I heard that yarn," I said. "Don't tell me you believe it?" "I come from Idaho," he told me. "And I happen to know the fellow who took the picture. Maybe it wasn't a disk, but something fell into that lake." "Did you see the picture?" "Yes, at the Pentagon." At my surprised look, he added, {p. 81} "That was long before they clamped down. I was talking to an Air Force officer about this lake thing, and he showed me the picture." "What did it look like?" "You couldn't tell much about it-just a big splash and a blur where something went under. Maybe a magnifying glass would bring it out, but I didn't get a chance to try it." It was early in 1950 when he told me this. I asked at the Pentagon if this picture was in the Wright Field files, and if so whether I could see it. My inquiries drew blank looks. No one remembered such a photograph. And even if it were in the Project "Saucer" files, I couldn't see it. This was more than two months after Project "Saucer" had been officially closed and its secrets presumably all revealed. The rest of my interviews during this 1949 trip helped to round out my picture of Project "Saucer" operations. Some witnesses seemed afraid to talk; a few flatly refused. I found no proof of official pressure, but I frequently had the feeling that strong hints had been dropped. Though one or two witnesses showed resentment at investigators' methods, most of them seemed more annoyed at the loss of time involved. One man had been checked first by the police, then by the sheriff's office; an Air Force team had spent hours questioning him, returning the next day, and finally the F.B.I. had made a character check. What he told me about the Air Force interrogation confirmed one of Art Green's statements. "One Intelligence captain tried to tell me I'd seen a weather balloon. I called up the airport and had them check on release schedules. They said next day it didn't fit any schedules around this area. Anyway, the wind wasn't right, because the thing I saw was cutting into the wind at a forty-five-degree angle." Other witnesses told me that investigators had suggested birds, meteors, reflections on clouds, shooting stars, and starshells as probable explanations of what they had seen. I learned of one pilot who had been {p. 82} startled by seeing a group of disks racing past his plane. Air Force investigators later suggested that he had flown through a flock of birds, or perhaps a cluster of balloons, On the flight back to Washington, I reread all the information the Air Force had released on Project "Saucer." Suddenly a familiar phrase caught my eye. I read over the paragraph again: "Preliminary study of the more than 240 domestic and thirty foreign incidents by Astro-Physicist Hynek indicates that an over-all total of about 30% can probably be explained away as astronomical phenomena." Explained away . I went through the report line by line. On page 17 I found this: "Available preliminary reports now indicate that a great number of sightings can be explained away as ordinary occurrences which have been misrepresented as a result of human errors." On page 22 I ran onto another use of the phrase: "The obvious explanation for most of the spherical-shaped objects reported, as already mentioned, is that they are meteorological or similar type balloons. This, however, does not explain reports that they travel at high speed or maneuver rapidly. But 'Saucer' men point out that the movement could be explained away as an optical illusion or actual acceleration of the balloon caused by a gas leak and later exaggerated by observers. . . . There are scores of possible explanations for the scores of different type sightings reported." Explained away . . . It might not mean anything. It could be just an unfortunate choice of words. But suppose that the real mission of Project "Saucer" was to cover up something. Or that its purpose was to investigate something serious, at the same time covering it up, step by step. The Project "Saucer" teams, then, would check on reports and simultaneously try to divert attention from the truth, suggesting various answers to explain the sightings. Back at Wright Field, analysts and Intelligence officers would go over the general picture and try to work up plausible explanations, which, if necessary, could even be published. {p. 83} "Explaining away" would be one of the main purposes of Project personnel. These words would probably be used in discussions of ways and means; they would undoubtedly would be used in secret official papers. And since this published preliminary report had been made up from censored secret files, the use of those familiar words might have been overlooked, since, read casually, they would appear harmless. If the report had been thrown together hastily, the use of these telltale words could be easily understood, and so could the report's strange contradictions. As an experiment, I fixed the idea firmly in mind that Project "Saucer" was a cover-up unit. Then I went back once more and read the items quoted above. The effect was almost startling. It was as though I were reading confidential suggestions for diverting attention and explaining away the sightings; suggestions made by Project members and probably circulated for comment. "Now, wait a minute," I said to myself. "You may be dreaming up this whole thing." Trying to get back to a neutral viewpoint, I skimmed through the other details of Project operations, as described in the report. The order creating Project "Saucer" was signed on December 30, 1947. (The actual code name was not "Saucer," but since for some reason the Air Force still has not published the name, I have followed their usage of "Saucer" in its place.) On January 22, 1948, two weeks after Captain Mantell's death, the project officially began operations. (Preliminary investigation at Godman Field had been done by local Intelligence officers.) Project "Saucer" was set up under the Air Materiel Command at Wright Field. Contracts were made with an astrophysicist (Professor Joseph Hynek), also a prominent scientist (still unidentified), and a group of evaluation experts (Rand Corporation). Arrangements were made for services by the Air Weather Service, Andrews Field; the U. S. Weather Bureau; the Electronics Laboratory, Cambridge Field Station; the A.M.C. Aero-Medical Laboratory; the Army {p. 84} and Navy Departments; the F.B.I.; the Department of Commerce, Civil Aeronautics Administration; and various other government and private agencies. In addition, the services of rocket experts, guided-missile authorities, space-travel planners, and others (in the defense services or assigned to them) were made available as desired. Under the heading "How Incidents Are Investigated," the Project "Saucer" report says: But the hoaxes and crank letters in reality play a small part in Project "Saucer." Actually, it is a serious, scientific business of constant investigation, analysis and evaluation which thus far has yielded evidence pointing to the conclusion that much of the saucer scare is no scare at all, but can be attributed to astronomical phenomena, to conventional aerial objects, to hallucinations and to mass psychology. But the mere existence of some yet unidentified flying objects necessitates a constant vigilance on the part of Project "Saucer" personnel and the civilian population. Investigation is greatly stepped up when observers report incidents as soon as possible to the nearest military installation or to Headquarters, A.M.C., direct. A standard questionnaire is filled out under the guidance of interrogators. In each case, time, location, size and shape of object, approximate altitude, speed, maneuvers, color, length of time in sight, sound, etc., are carefully noted. This information is sent in its entirety, together with any fragments, soil photographs, drawings, etc., to Headquarters, A.M.C. Here, highly trained evaluation teams take over. The information is broken down and filed on summary sheets, plotted on maps and graphs and integrated with the rest of the material, giving an easily comprehended over-all picture. Duplicate copies on each incident arc sent to other investigating agencies, including technical labs within the Air Materiel Command. These are studied in relation to many factors such as guided missile research {p. 85} activity, weather, and many others, atmospheric sounding balloon launchings, commercial and military aircraft flights, flights of migratory birds and a myriad of other considerations which might furnish explanations. Generally, the flying objects are divided into four groups: Flying disks, torpedo or cigar-shaped bodies with no wings or fins visible in flight, spherical or balloon-shaped objects and balls of light. The first three groups are capable of flight by aerodynamic or aerostatic means and can be propelled and controlled by methods known to aeronautical engineers. As for the lights, their actions--unless they were suspended from a higher object or were the product of hallucination--remain unexplained. Eventually, reports are sent back to Project "Saucer" headquarters, often marking incidents closed. The project, however, is a young one-much of its investigation is still under way. Currently, a psychological analysis is being made by A.M.C.'s Aero-Medical laboratory to determine what percentage of incidents are probably based on errors of the human mind and senses. Available preliminary reports now indicate that a great number can be explained away as ordinary occurrences which have been misrepresented as a result of these human errors. Near the end of the last page, a paragraph summed tip the report. "The 'Saucers' are not a joke. Neither are they cause for alarm to the population. Many of the incidents already have answers. Meteors. Balloons. Falling stars. Birds in flight. Testing devices, etc. Some of them still end in question marks." From what I had learned on this trip, I strongly doubted the answer suggested. All but the "testing devices." What did they mean by that? It could be a hint at guided missiles; they had already mentioned guided-missile research activity in another spot. But if that was what lay behind this elaborate project, {p. 86} they would hardly be hinting at it. If the answer was space travel, then such hints made sense, They would be part of the cover-up plan. Everyone--including the Soviet Union--knew we were working on guided missiles. It would do no harm to use this as one of the "myriad explanations" for the flying saucers. I was still trying to figure it out when my plane let down for the landing at Washington. I had hoped by this time to know the truth about Project "Saucer." Instead, it was a deeper mystery than ever. True, I had found out how they operated--outside of Wright Field. Some of the incidents had been enlightening. By now, I was certain that Project "Saucer" was trying hard to explain away the sightings and hide the real answer. {p. 87} CHAPTER X WHEN I reached home, I found a brief letter from Ken Purdy. Dear Don: The Mantell and Eastern cases both look good. I don't see how they can brush them off. It looks more like the interplanetary answer to me, but we won't decide on treatment until we're sure. [I had suggested two or three angles, if this proved the real answer.] Who would be the best authority to check our disk operation theory and give us more details on directional control? I'd like to have it checked by two more engineers. KEN Next day, I dug out my copy of Boal's interview with D------, the famous aircraft designer. "Certainly the flying saucers are possible," the designer had told Boal. "Give me enough money and I'll build you one. It might have to be a model because the fuel would be a problem. If the saucers that have been seen came from other worlds, which isn't at all Buck Rogerish, they may be powered with atomic energy or by the energy that produces cosmic rays--which is many times more powerful--or by some other fuel or natural force that our research hasn't yet discovered. But the circular airfoil is quite feasible. "It wouldn't have the stability of the conventional airplane, but it would have enormous maneuverability--it could rise vertically, hover, descend vertically, and fly at extremely high speed, with the proper power. Don't take my word for it. Check with other engineers." Before looking up a private engineer I had in mind, I went to the National Advisory Committee for Aeronautics. The N.A.C.A. {the predecessor of NASA--jbh} is America's most authoritative source of aerodynamic knowledge. I knew they had already tried {p. 88} out disk-shaped airfoils, and I asked about this first. I found that two official N.A.C.A. reports, Technical Note 539 and Report 431, discuss tests on circular and elliptical Clark Y airfoils. Both reports state that these designs were found practical. Later, I talked with one of the top engineers in the N.A.C.A. Without showing him D------'s sketch, I asked how a disk might operate. "It could be built with variable-direction jet or rocket nozzles," be said. "The nozzles would be placed around the rim, and by changing their direction the disk could be made to rise and descend vertically. It could hover, fly straight ahead, and make sharp turns. "Its direction and velocity would be governed by the number of nozzles operating, the power applied, and the angle at which they were tilted. They could be pointed toward the ground, rearward, in a lateral direction, or in various combinations. "A disk flying level, straight ahead, could be turned swiftly to right or left by shifting the angles of the nozzles or cutting off power from part of the group. This method of control would operate in the earth's atmosphere and also, using rocket power, in free space, where conventional controls would be useless." The method he had described was not the one which D------ had outlined. "What about a rotating disk?" I asked the N.A.C.A. man. "Suppose you had one with a stationary center, and a large circular section rotating around it? The rotating part would have a camber built into it, or it would have slotted vanes." He gave me a curious look, "Where'd you get that idea about the camber?" I told him it had come to me from True. "It could be done," he said. "The slotted-vanes method has already been tried. There's an engineer in Glendale, California, who's built a model. His name's E. W. Kay." He gave me a few details on how a cambered or slotted-vane rotating disk might operate, then interrupted himself to ask me what I thought the saucers were. {p. 89} "They're either interplanetary or some secret development," I said. 'What do you think?" "The N.A.C.A. has no proof they even exist," he answered. When I left the building a few minutes later, I was still weighing that statement. If the Air Force or the Navy had a secret disk device, the N.A.C.A. would almost certainly know about it. The chances were that any disk-shaped missile or new type of circular aircraft would first have been tested in the N.A.C.A. wind tunnels at Langley Field. If the saucers were interplanetary, the N.A.C.A.--at least top officials--would probably have been in on any discussion of the disks' performance. Either way, the N.A.C.A.'s official attitude could be expected to match the Pentagon's. After lunch, I took a taxi to the office of the private engineer. Like D------, he has asked that he not be quoted by name. The name I am using, Paul Redell, will serve that purpose. Redell is a well-known aeronautical engineer. He has worked with major aircraft companies and served as a special consultant to government agencies and the industries. He is also a competent pilot. Although I had known him several years, he refused at first to talk about the saucers. Then I realized he thought I meant to quote him. I showed him some of the material I had roughed out, in which names were omitted or changed as requested. "All right," Redell said finally. "What do you want to know?" "Anything you can tell us. But first, your ideas on these sketches." I showed him D------'s drawings and then gave him the high points of the investigation. When I mentioned the mystery-light incident at Fairfield Suisan Air Force Base, Redell sat up quickly. "The Gorman case again!" "We heard about some other 'light' cases," I said. "One was at Las Vegas." "I know about that one. That is, it you mean the green light--wait a minute!" Redell frowned into space for a few seconds, "You say that Fairfield Suisan sighting {p. 90} was on December third? Then the Las Vegas sighting was only a few days later. It was the first week of the month, I'm positive." "Those light reports have got me stumped," I said. "A light just can't fly around by itself. And those two-foot disks--" "You haven't worked on the Gorman case?" asked Redell. I told him I hadn't thought it was coming up on my schedule. "Leave these sketches here," he said. "Look into that Gorman sighting. Then check on our plans for space exploration. I'll give you some sources. When you get through, come on back and we'll talk it over." The Gorman "saucer dogfight" had been described in newspapers; the pilot had reported chasing a swiftly maneuvering white light, which had finally escaped him. Judging from the Project "Saucer" preliminary report, this case had baffled all the Air Force investigators. When I met George Gorman, I found him to be intelligent, coolheaded, and very firmly convinced of every detail in his story. I had learned something about his background. He had had college training. During the war, he had been an Air Force instructor, training French student pilots. In Fargo, his home, he had a good reputation, not only for veracity but as a businessman. Only twenty-six, he was part owner of a construction company, and also the Fargo representative for a hardware-store chain. Even knowing all this, I found it hard at first to believe some of the dogfight details. But the ground observers confirmed them. It was about nine o'clock in the evening, October 1, 1948. Gorman, now an Air National Guard lieutenant, had been on a practice flight in an F-51 fighter. The other pilots on this practice patrol had already landed. Gorman had just been cleared by the C.A.A. operator in the Fargo Airport tower when he saw a fast-moving light below his circling fighter. From his altitude, 4,500 feet, it appeared to be the tail light of a swiftly flying plane. As nearly as he could tell, it was 1,000 feet high, moving at about 250 m.p.h. {p. 91} Gorman called the tower to recheck his clearance. He was told the only other plane in the area was a Piper Cub. Gorman Could see the Cub plainly outlined below him. There was a night football game going on, and the field was brightly lighted. But the Cub was nowhere near the strange light. As the mystery light raced above the football field. Gorman noticed an odd phenomenon. Instead of seeing the silhouette of a plane, he saw no shape at all around the light. By contrast, he could see the Cub's outline clearly. Meantime, the airport traffic controller, L. D. Jensen, had also spotted the queer light. Concerned with the danger of collision--he said later that he, too, thought it a plane's tail light--he trained his binoculars on it. Like Gorman, he was unable to distinguish a shape near the light. Neither could another C.A.A. man who was with him in the tower, a Fargo resident named Manuel E. Johnson. Up in the F-51, Gorman dived on the light, which was steadily blinking on and off. "As I closed in," he told Project "Saucer" men later, "it suddenly became steady and pulled up into a sharp left turn. It was a clear white and completely roundabout six to eight inches in diameter. "I thought it was making a pass at the tower. I dived after it and brought my manifold pressure up to sixty, but I couldn't catch the thing." Gorman reported his speed at full power as 350 to 400 miles per hour. During the maneuvers that followed, both the C.A.A. men watched from the tower. Jensen was using powerful night glasses, but still no shape was visible near the mysterious light. The fantastic dogfight continued for twenty minutes. Gorman described it in detail. "When I attempted to turn with the light, I blacked out temporarily, owing to excessive speed. I am in fairly good physical condition, and I don't believe there are many, if any, pilots who could withstand the turn and speed effected by the light and remain conscious." {p. 92} During these sharp maneuvers, the light climbed quickly, then made another left bank. "I put my fifty-one into a sharp turn and tried to cut it off," said Gorman. "By then we were at about seven thousand feet, Suddenly it made a sharp right turn and we headed straight at each other. Just when we were about to collide I guess I lost my nerve. I went into a dive and the light passed over my canopy at about five hundred feet. Then it made a left circle about one thousand feet above and I gave chase again." When collision seemed imminent a second time, the object shot straight into the air. Gorman climbed after it at full throttle. Just about this time, two. other witnesses, a private pilot and his passenger, saw the fast-moving light. The pilot was Dr. A. D. Cannon, an oculist; his passenger was Einar Nelson. Dr. Cannon later told investigators the light was moving at high speed. He thought it might be a Canadian jet fighter from over the border. (A careful check with Canadian air officials ruled out this answer.) After landing at the airport, Dr. Cannon and Mr. Nelson again watched the light, saw it change direction and disappear. Meanwhile, Gorman was making desperate efforts to catch the thing. He was now determined to ram it, since there seemed nothing solid behind it to cause a dangerous crash. If his fighter was disabled, or if it caught fire, he could bail out. But despite the F-51's fast climb, the light still outdistanced him. At 14,000 feet, Gorman's plane went into a power stall, He made one last try, climbing up to 17,000 feet. A few moments later, the light turned in a north-northwest direction and quickly disappeared. Throughout the dogfight, Gorman noticed no deviation on his instruments, according to the Project "Saucer" report. Gorman did not confirm or deny this when I talked with him. But he did agree with the rest of the Project statement. He did not notice any sound, odor, or exhaust trail. Gorman's remarks about ramming the light reminded me of what Art Green had said. When I asked Gorman {p. 93} about the court-martial rumor, he gave me a searching glance. "Where did you hear that?" "Several places," I told him. "At Chicago, in Salt Lake City--in fact, we've been hearing it all over." "Well, there's nothing to it," Gorman declared. He changed the subject. Some time afterward, a Fargo pilot told me there had been trouble over the ramming story. "But it wasn't Gorman's fault. Somebody else released that report to the A. P. The news story didn't actually say there was an Air Force order to ram it, but the idea got around, and we heard that Washington squawked. Gorman had a pretty rough time of it for a while. Some of the newspapers razzed his story. And the Project 'Saucer' teams really worked on him. I guess they were trying to scare him into saying he was mistaken, and it was a balloon." When I asked Gorman about this, he denied he'd had rough treatment by the Project teams. "Sure, they asked about a thousand questions, and I could tell they thought it might be a hoax at first. But that was before they quizzed the others who saw it." "Anybody suggest it was a balloon?" I said casually. "At first, they were sure that's what it was," answered Gorman. "You see, there was a weather balloon released here. You know the kind, it has a lighted candle on it. The Project teams said I'd chased after that candle and just imagined the light's maneuvers--confused it with my own movement, because of the dark." Gorman grinned. "They had it just about wrapped up--until they talked to George Sanderson. He's the weather observer. He was tracking the balloon with a theodolite, and he showed them his records. The time and altitudes didn't fit, and the wind direction was wrong. The balloon was drifting in the opposite direction. Both the tower men backed him up. So that killed the weather-balloon idea." The next step by Project "Saucer" investigators had been to look for some unidentified aircraft. This failed, too. Obviously, it was only routine; the outline of a conventional {p. 94} plane would certainly have been seen by Gorman and the men in the tower. An astronomical check by Professor Hynek ruled out stars, fireballs, and comets--a vain hope, to begin with. The only other conventional answer, as the Project report later stated, was hallucination. In view of all the testimony, hallucination had to he ruled out. Finally, the investigators admitted they had no solution. The first Project "Saucer" report, on April 27, 1949, left the Gorman "mystery light" unidentified. In the Saturday Evening Post of May 7, 1949, Sidney Shallett analyzed the Gorman case, in the second of his articles on flying saucers. Shallet suggested this solution: that Gorman had chased one of the Navy's giant cosmic-ray research balloons. Each of these huge balloons is lighted, so that night-flying planes will not collide with the gas bag or the instrument case suspended below. Shallett concluded that Gorman was suffering from a combination of vertigo and confusion with the light on the balloon. As already mentioned, these huge Navy balloons are filled with only a small amount of helium before their release at Minneapolis. They then rise swiftly to very high altitudes, unless a leak develops. In Shallett's words, "These balloons travel high and fast. . . ." Fargo is about two hundred miles from Minneapolis. Normally, a cosmic-ray research balloon would have reached a very high altitude by the time it had drifted this far. The only possible answer to its low-altitude sighting would be a serious leak. If a leaking balloon had come down to one thousand feet at Fargo, it would either have remained at that height or kept on descending. The mystery light was observed at this altitude moving at high speed. If a Cub's outline was visible against the lighted football field, the massive shape of even a partly deflated balloon would have stood out like an elephant. Even before release, the partially inflated gas bags are almost a hundred feet tall. The crowd at the football game would certainly have seen such a monstrous shape above the glare of the floodlights, for the plastic balloons gleam brightly {p. 95} in any light rays. The two C.A.A. men, watching with binoculars, could not possibly have missed it. For the cosmic-balloon answer to be correct, this leaking gas bag would have had to rise swiftly to seventeen thousand feet--after a loss of helium had forced it down to one thousand. As a balloon pilot, I know this is impossible. The Project "Saucer" report said unequivocally: "The object could outturn and outspeed the F-51, and was able to attain a much steeper climb and to maintain a constant rate of climb far in excess of the Air Force fighter." A leaking balloon? More and more, I became convinced that Secretary Forrestal had persuaded some editors that it was their patriotic duty to conceal the answer, whatever it was. That thought had begun to worry me, because of my part in this investigation. Perhaps John Steele had been right, and we shouldn't be trying to dig out the answer. But I had already told Purdy, and he had agreed, that if national security was involved, we would drop the thing completely. By the time I had proved the balloon answer wrong, I was badly puzzled. The idea of a disembodied light was the hardest thing to swallow that I'd come across so far. And yet there were the other light reports--the strange sighting at Fairfield Suisan Field, the weird green lights at Las Vegas and Albuquerque. And there was the encounter that Lieutenant H. G. Combs had had one night above Andrews Field, near Washington, D. C. This incident had occurred on November 18, 1948, six weeks after Gorman's experience. Combs, flying with another lieutenant named Jackson, was about to land his T-6, at 9:45 P.M., when a strange object loomed up near him. It looked like a grayish globe, and it gave off an odd, fuzzy light. Combs chased the weird object for over ten minutes, during which it appeared to evade every move he made. Once, its speed was nearly six hundred miles an hour, as closely as he could estimate. In a final attempt to identify it, Combs zoomed the T-6 up at a steep angle {p. 96} and flashed his landing lights on it. Before he could get a good look, the globe light whirled off to the east and vanished. Since Combs's story had been in the newspapers, Project "Saucer" evidently had felt in wise to give some explanation. When I read it, in the preliminary report, I was amazed. Here was the concluding sentence: "The mystery was cleared up when the object was identified positively as a cluster of cosmic-ray research balloons." Even one of the giant balloons would have been hard to take as the explanation. Combs was almost sure to have collided with it in his head-on passes. But an entire cluster! I tried to picture the T-6 zooming and twisting through the night sky, with several huge balloons in its path. It would be a miracle if Combs got through without hitting one of them, even if each balloon was lighted. But he had seen only one light; so had Lieutenant Jackson. That would mean all the rest of the balloons were unlighted--an unbelievable coincidence. It was not until months afterward that I found Project "Saucer" had withdrawn this "solution." In its final report, this case, Number 207, was listed in the "Unidentified" group. How the balloon-cluster explanation ever got into the first report is still a mystery. When I talked with Gorman, I told him I was baffled by the idea of a light maneuvering through the skies with no airfoil to support it. "I know," he said. "It got me, too, at first." "You mean you know the answer?" I demanded. "It's just my personal opinion," said Gorman. "But I'd rather not have it printed. You see, I got some ideas from all the questions those Project teams asked me. If my hunch turns out to be right, I might be talking about an official secret." I tried to pry some hint out of him, but Gorman just smiled and shook his head. "I can tell you this much," he said, "because it's been mentioned in print. There was thought behind every move the light made. It wasn't any radar-responder gadget making it veer away from my ship." {p. 97} "How do you know that?" "Because it reacted differently at different times. If it had been a mechanical control, it would have turned or climbed the same way each time I got near it. Instead, it was as if some intelligent mind was directing every turn like a game of chess, and always one move ahead of me. Maybe you can figure out the rest." That was all I could get out of him. It bothered me, because Combs's report indicated the same thing. I had a strong temptation to skip the space-plans research and tell Redell what Gorman had told me. But Redell had an orderly mind, and he didn't like to be pushed. Reluctantly, I gave up the idea. I had a feeling Redell knew the answer to the mystery lights, and it wasn't easy to put off the solution. The letter that came from Art Green, while I was working on the space plans, didn't make it easier: Dear Keyhoe: Just heard about your Seattle visit. That Fairfield Suisan thing is on the level; several Air Force pilots have told me about it. When you get to Fargo, ask Gorman what they found when they checked his ship with a Geiger counter. If he says it was negative, then he must be under orders. I happen to know better. Yours, ART GREEN {p. 98} CHAPTER XI MY FIRST STEP, in checking on our space plans, was to look up official announcements. I found that on December 29, 1948, Defense Secretary James Forrestal had released this official statement: "The Earth Satellite Vehicle Program, which is being carried out independently by each military service, has been assigned to the Committee on Guided Missiles for co-ordination. "To provide an integrated program, the Committee has recommended that current efforts be limited to studies and component design. Well-defined areas of such research have been allocated to each of the three military departments." Appropriation bills had already provided funds for space exploration plans. The Air Force research was indicated by General Curtis E. LeMay, who was then Deputy Chief of Air Staff for Research and Development. In outlining plans for an Air Engineering Design Center at Wright Field, General LeMay included these space-exploration requisites: "Flight and survival equipment for ultra-atmospheric operations, including space vehicles, space bases, and devices for use therein." The idea of exploring space is, of course, nothing new. For many years, writers of imaginative fiction have described trips to the moon and distant planets. More recently, comic books and strips have gone in heavily for space-travel adventures. As a natural result of this, the first serious rocket experiments in this country were labeled screwball stunts, about on a par with efforts to break through the sonic barrier. The latter had been "proved" impossible by aeronautical engineers; as for rocket flight, it was too silly for serious consideration. Pendray, Goddard, and other rocket pioneers took some vicious ridicule before America woke up to the possibilities. Meantime, German scientists had gone far ahead. {p. 98} Their buzz bomb, a low-altitude semi-guided missile, was just the beginning. Even the devastating V-2, which soared high into the stratosphere before falling on England, was just a step in their tremendous space program. If the Nazis could have hung on a year or two more, the war might have had a grimly different ending. When the Allies seized Nazi secrets, some of the German plans were revealed. Among them was one for a huge earth satellite. From this base, which would circle the earth some five hundred miles away, enormous mirrors would focus the sun's rays on any desired spot. The result: swift, fiery destruction of any city or base refusing to surrender. First publication of this scheme brought the usual jeers. Many people, including some reputable scientists, believed it had been just a propaganda plan that even Goebbels had discarded as hopeless. Then the Pentagon announced the U.S. Earth Satellite Vehicle Program, along with plans for a moon rocket, The artificial satellite is to be a large rocket-propelled projectile. In its upward flight, it will have to reach a speed of 23,000 miles an hour, to escape the earth's pull of gravity. At a height of about 500 miles, special controls will turn the projectile and cause it to circle the earth. These controls will be either automatic or operated from the ground, by radar. Theoretically, once such a vehicle is beyond gravity's magnetism, it can coast along in the sky forever. Its rocket power will be shut off; the only need for such power would be if the satellite veered off course. A momentary burst from the jets would be sufficient to bring it back to its orbit. Circling the earth in about two hours, this first satellite is expected to be used as a testing station. Instruments will record and transmit vital information to the earth--the effect of cosmic rays, solar radiation, fuel required for course corrections, and many other items. A second space base farther out will probably be the next step. It may be manned, or it may be under remote control like the first. Perhaps the first satellite vehicle will be followed by a compartmented operating base, a sort of aerial aircraft carrier, with other rocket {p. 100} ships operating to and fro on the earth shuttle. The moon rocket is expected to add to our information about space, so that finally we will emerge with an interplanetary space craft. The first attempts may fail. The first satellite may fall back and have to be guided to an ocean landing. Or its controls might not bring it into the planned orbit. In this case, it could coast on out into space and be lost. But sooner or later, effective controls will be found. Then the manned space ships will follow. Once in free space, there will be no gravitational pull to offset. The space ship and everything in it will be weightless. Shielding is expected to prevent danger from cosmic rays and solar radiation. The danger from meteorites has been partly discounted in one scientific study. ("Probability that a meteorite will hit or penetrate a body situated in the vicinity of the earth," by G. Grimminger, Journal of Applied Physics, Vol. 19, No. 10, pp. 947-956, October 1948) In this study, it is stated that a meteorite is unlikely to penetrate the thick shell our space vehicles will undoubtedly have. However, this applies only to the earth's atmosphere. Longer studies, using remote-controlled vehicles in space, may take years before it will be safe to launch a manned space ship. Radar or other devices may have to be developed to detect approaching meteorites at a distance and automatically change a space ship's course. The change required would be infinitesimal, using power for only a fraction of a second. But before we are ready for interplanetary travel, we will have to harness atomic power or some other force not now available, such as cosmic rays. Navigation at such tremendous speeds is another great problem, on which special groups are now at work. A Navy scientific project recently found that strange radio signals are constantly being sent out from a "hot spot" in the Milky Way; other nebulae or "hot" stars may be similarly identified by some peculiarity in their radio emanations. If so, these could be used as check points in long-range space travel. Escape from the earth's gravity is possible even now, {p. 101} according to Francis H. Clauser, an authority on space travel plans. But the cost would be prohibitive, with our present rocket motors, and practical operations must wait for higher velocity rocket power, atomic or otherwise. ("Flight beyond the Earth's Atmosphere, "S.A.E. Quarterly Transactions, Vol. 2, No, 4, October 1948.) Already, a two-stage rocket has gone more than 250 miles above the earth. This is the V-2-Wac Corporal combination. The V-2 rocket is used to power the first part of the flight, dropping off when its fuel is exhausted. The Wac Corporal then proceeds on its own fuel, reaching a fantastic speed in the thin air higher up. Hundreds of technical problems must be licked before the first satellite vehicle can be launched successfully. Records on our V-2 rockets indicate some of the obstacles. On the take-off, their present swift acceleration would undoubtedly kill anyone inside. When re-entering the earth's atmosphere the nose of a V-2 gets red-hot. Both the acceleration and deceleration must be controlled before the first volunteers will be allowed to hazard their lives in manned rockets. Willi Ley, noted authority on space-travel problems, believes that pilots may have to accept temporary blackout as a necessity on the take-off. (Two of his books, Rockets and Space Travel and Outer Space, give fascinating and well-thought-out pictures of what we may expect in years to come.) Some authorities believe that our space travel will be confined to our own solar system for a long time, perhaps forever. The trip to the moon, though now a tremendous project, would be relatively simple compared with a journey outside our system. Escape from the moon, for the return trip, would be easier than leaving the earth; because of its smaller mass, to escape the moon's gravitational pull would take a speed of about 5,000 miles an hour, against 23,000 for the earth. Navigation would be much simpler. Our globe would loom up in the heavens, much larger and brighter than the moon appears to us. Radar beams would also be a guide. The greatest obstacle to reaching far-distant planet is the time required. In the Project "Saucer" study of {p. 102} space travel, Wolf 359 was named as the nearest star likely to have possibly inhabited areas. Wolf 359 is eight light-years from the earth. The limiting speed in space, according to Einstein's law, would be just under the speed of light--186,000 miles per second. At this speed, Einstein states, matter is converted into energy. It is a ridiculous assumption, but even if atomic power, or some force such as cosmic rays, made an approach to that speed possible, it would still take eight years to reach Wolf 359. The round trip would take sixteen. There have been a few scientists who dispute Einstein's law, though no one has disproved it. If the speed of light is not an absolute limit for space ships, then travel to remote parts of the universe may someday be possible. Otherwise, a trip outside our solar system could be a lifetime expedition. Most space travel would probably be limited to the planets of our sun--the moon, Mars, Venus, Jupiter, and the others. Although it may be many years before the first manned space ship leaves the earth, we are already at work on the problems the crews would face. I learned some of the details from a Navy flight surgeon with whom I had talked about take-off problems. "They're a lot further than that" he told me. "Down at Randolph Field, the Aero-Medical research lab has run into some mighty queer things. Ever hear of 'dead distance'?" "No, that's a new one." "Well, it sounds crazy, but they've figured out that a space ship would be going faster than anyone could think." "But you think instantaneously," I objected. "Oh, no. It takes a fraction of a second, even for the fastest thinker. Let's say the ship was making a hundred miles a second--and that's slow compared with what they expect eventually. Everything would happen faster than your nerve impulses could register it. Your comprehension would always be lagging a split second behind the space ship's operation." "I don't see why that's so serious," I said. {p. 103} "Suppose radar or some other device warned you a meteorite was coming toward you head-on. Or maybe some instrument indicated an error in navigation. By the time your mind registered the thought, the situation would have changed." "Then all the controls would have to be automatic," I said. I told him that I had heard about plans for avoiding meteorites. "Electronic controls would be faster than thought." "That's probably the answer," he agreed. "Of course, at a hundred miles a second it might not be too serious. But if they ever get up to speeds like a thousand miles a second, that mental lag could make an enormous difference, whether it was a meteorite heading toward you or a matter of navigation." One of the problems he mentioned was the lack of gravity. I had already learned about this. Once away from the earth's pull, objects in the space ship would have no weight. The slightest push could send crewmen floating around the sealed compartment. "Suppose you spilled a cup of coffee," said the flight surgeon. "What would happen?" I said I hadn't thought it out. "The Randolph Field lab can tell you," he said. "The coffee would stay right there in the air. So would the cup, if you let go of it. But there's a more serious angle--your breath." "You'd have artificial air," I began. "Yes, they've already worked that out. But what about the breath you exhale? It contains carbon dioxide, and if you let it stay right there in front of your face you'd be sucking it back into your lungs. After a while, it would asphyxiate you. So the air has to be kept in motion, and besides that the ventilating system has to remove the carbon dioxide." "What about eating?" I asked. "Swallowing is partly gravity, isn't it?" He nodded. "Same as drinking, though the throat muscles help force the food down. I don't know the answer to that. In fact, everything about the human body presents a problem. Take the blood circulation. The {p. 104} amount of energy required to pump blood through the veins would be almost negligible. What would that do to your heart?" "I couldn't even guess," I said. "Well, that's all the Aero-Medical lab can do--guess at it. They've been trying to work out some way of duplicating the effect of zero gravity, but there's just no answer. If you could build a machine to neutralize gravity, you could get all the answers, except to the 'dead distance' question. "For instance, there's the matter of whether the human body would even function without gravity. All down through the stages of evolution, man's organs have been used to that downward pull. Take away gravity, and your whole body might stop working. Some of the Aero-Medical men I've talked with don't believe that, but they admit that long trips outside of gravity might have odd effects. "Then there's the question of orientation. Here on earth, orienting yourself depends on the feeling you get from the pull of gravity, plus your vision. just being blindfolded is enough to disorient some people. Taking away the pull of gravity might be a lot worse. And of course out in space your only reference points would be distant stars and planets. We've been used to locating stars from points on the earth, where we know their position. But how about locating them from out in space, with a ship moving at great speed? Inside the space ship, it would be something like being in a submarine. Probably only the pilot compartment would have glass ports, and those would be covered except in landing--maybe even then. Outside vision might be by television, so you couldn't break a glass port and let out your pressure. "But to go back to the submarine idea. It would be like a sub, with this big difference: In the submarine you can generally tell which way is down, except maybe in a crash dive when you may lose your equilibrium for a moment. But in the space ship, you could be standing with your feet on one spot, and another crewman might be--relative to you--standing upside down. You might be floating horizontally, the other man vertically. {p. 105} The more you think about it, the crazier it gets. But they've got to solve all those problems before we can tackle space." To make sure I had the details right, I checked on the Air Force research. I found that the Randolph Field laboratory is working on all these problems, and many more. Although plans arc not far enough advanced to make it certain, probably animals will be sent up in research rockets to determine the effect of no gravity before any human beings make such flights. The results could be televised back to the earth. All through my check-up on space exploration plans, one thing struck me: I met no resistance. There was no official reticence about the program; on the contrary, nothing about it seemed secret. Even though it was peacetime, this was a little curious, because of the potential war value of an earth satellite vehicle. Even if the Nazi scheme for destruction proved just a dream, an orbiting space base could be used for other purposes. In its two-hour swing around the earth, practically all of the globe could be observed-directly, by powerful telescopes, or indirectly, by a combination of radar and television. Long-range missiles could be guided to targets, after being launched from some point on the earth. As the missiles climbed high into the stratosphere, the satellite's radar could pick them up and keep them on course by remote control. There were other possibilities for both attack and defense. Ordinarily, projects with wartime value are kept under wraps, or at least not widely publicized. Of course, the explanation might be very simple: The completion of the satellite vehicle was so remote that there seemed no need for secrecy. But in that case, why had the program been announced at all? If the purpose had been propaganda, it looked like a weak gesture. The Soviets would not be greatly worried by a dream weapon forty or fifty years off. Besides that, the Pentagon, as a rule, doesn't go for such propaganda. There was only one conventional answer that made any sense. If we had heard that the Soviets were about {p. 106} to announce such a program, as a propaganda trick, it would be smart to beat them to it. But I had no proof of, any such Russian intention. The date on Secretary Forrestal's co-ordination announcement was December 30, 1948. One day later, the order creating Project "Saucer" had been signed. That didn't prove anything; winding up the year, Forrestal could have signed a hundred orders. I was getting too suspicious. At any rate, I had now analyzed the Gorman case and checked on our space plans. Tomorrow I would see Redell and find out what he knew. {p. 107} CHAPTER XII 'WHEN I called Redell's office I found he had flown to Dallas and would not be back for two days. By the time he returned, I had written a draft of the Gorman case, with my answer to the balloon explanation. When I saw him, the next morning, I asked him to look it over. Redell lighted his pipe and then read the draft, nodding to himself now and then. "I think that's correct analysis," he said when he finished. "That was a very curious case. You know, Project 'Saucer' even had psychiatrists out there. If Gorman had been the only witness, I think they'd have called it a hallucination. As it was, they took a crack at him and the C.A.A. men in their preliminary report." Though I recalled that there had been a comment, I didn't remember the wording. Redell looked it up and read it aloud: "'From a psychological aspect, the Gorman incident raised the question, "Is it possible for an object without appreciable shape or known aeronautical configuration to appear to travel at variable speeds and maneuver intelligently?"'" "Hallucination might sound like a logical answer," I said, "until you check all the testimony. But there are just too many witnesses who confirm Gorman's report. Also, he seems like a pretty level-headed chap." Redell filled his pipe again. "But you still can't quite accept it?" "I'm positive they saw the light--but what the devil was it? How could it fly without some kind of airfoil?" "Maybe it didn't. You remember Gorman described an odd fuzziness around the edge of the light? It's in this Air Force report. That could have been a reflection from the airfoil." "Yes, but Gorman would have seen any solid--" I stopped, as Redell made a negative gesture. "It could be solid and still not show up," he said. "You mean it was transparent? Sure, that would do it!" {p. 108} "Let's say the airfoil was a rotating plastic disk, absolutely transparent. The blurred, fuzzy look could have been caused by the whirling disk. Neither Gorman nor the C.A.A. men in the tower could possibly see the disk itself." "Paul, I think you've hit it," I said. "I can see thc rest of it--the thing was under remote control, radio or radar. And from the way it flew rings around Gorman, whoever controlled it must have been able to see the F-51, either with a television 'eye' or by radar," "Or by some means we don't understand," said Redell. He went on carefully, "In all these saucer cases, keep this in mind: We may be dealing with some totally unknown principle--something completely beyond our comprehension." For a moment, I thought he was hunting at some radical discovery by Soviet--captured Nazi scientists. Then I realized what he meant. "You think they're interplanetary," I murmured. "Why not?" Redell looked surprised. "Isn't that your idea? I got that impression." "Yes, but I didn't think you believed it. When you said to check on our space plans, I thought you had some secret missile in mind." "No, I had another reason. I wanted you to see all the problems involved in space travel. If you accept the interplanetary answer, you have to accept this, too--whoever is looking us over has licked all those problems years ago. Technically, they'd be hundreds of years ahead of us--maybe thousands. It has a lot to do with what they'd be up to here." When I mentioned the old sighting reports, I found that Redell already knew about them. He was convinced that the earth had been under observation a long time, probably even before the first recorded sightings. "I know some of those reports aren't authentic," he admitted. "But if you accept even one report of a flying disk or rocket-shaped object before the twentieth century, then you have to accept the basic idea. In the last forty years, you might blame the reports on planes and dirigibles. But there was no propelled aircraft until 1903. {p. 109} Either all those early sightings were wrong, or some kind of fast aerial machine has been flying periodically over the earth for at least two centuries. I told him I was pretty well convinced, but that True faced a problem. There was some conflicting evidence, and part of it seemed linked with guided missiles. I felt sure we could prove the space-travel answer, but we had to stay clear of discussing any weapons that were still a secret. "I can't believe that guided missiles are the answer to the Godman Field saucer and the Chiles-Whitted case, or this business at Fargo. But we're got to be absolutely sure before we print anything." "Well, let's analyze it," said Redell. "Let's see if all the saucers could be explained as something launched from the earth." He reached for a pad and a pencil. "First, let's take your rotating disk. That would be a lot simpler to build than the stationary disk with variable jet nozzles. With a disk rotated at high speed you get a tremendous lift, whether it's slotted or cambered, as long as there's enough air to work on." "The helicopter principle," I said. Redell nodded. "The most practical propulsion would be with two or more jets out on the rim, to spin your rotating section. But to get up enough speed for the jets to be efficient, you'd have to whirl the disk mechanically before the take-off. Here's one way. You could have a square hole in the center; then the disk launching device would have a square shaft, rotated by an engine or a motor. As the speed built up, the cambered disk would ride up the shaft and free itself, rising vertically, with the jets taking over the job of whirling the cambered section. "The lift would be terrific, far more than any normal aircraft. I don't believe any human being could take the G's involved in a maximum power climb; they'd have to use remote control. When it got to the desired altitude, your disk could be flown in any direction by tilting it that way. The forward component from that tremendous {p. 110} lift would result in a very high speed. The disk could also hover, and descend vertically." "What about maneuvering?" I asked, thinking of Gorman's experience. "It could turn faster than any pilot could stand," said Redell. "Of course, a pilot's cockpit could be built into a large disk; but there'd have to be some way of holding down the speed, to avoid too many G's in tight maneuvers." "Most of the disks don't make any noise," I said. "At least, that's the general report. You'd hear ordinary jets for miles." "Right, and here's another angle. Ram jets take a lot of fuel. Even with some highly efficient new jet, I can't see the long ranges reported. Some of these saucers have been seen all over the world. No matter which hemisphere they were launched from, they'd need an eight-thousand-mile range, at least, to explain all of the sightings. The only apparent answer would be some new kind of power, probably atomic. We certainly didn't have atomic engines for aircraft in 1947, when the first disks were seen here. And we don't have them now, though we're working on it. Even if we had such an engine, it wouldn't be tiny enough to power the small disks." "Anyway," I said, "we'd hardly be flying them all over everywhere. The cost would be enormous, and there'd always be a danger of somebody getting the secret if a disk landed." "Plus the risk of injuring people by radiation. just imagine an atomic-powered disk dropping into a city. The whole idea's ridiculous." "That seems to rule out the guided-missile answer," I began. But Redell shook his head. "Disk-shaped missiles are quite feasible. I'm talking about range, speed, and performance. Imagine for a moment that we have disk-type missiles using the latest jet or rocket propulsion--either piloted or remote-controlled. The question is, could such disks fit specific sightings like the one at Godman Field and the case at Fargo?" Redell paused as if some new thought had struck him. "Wait a minute, here's an even better test. I happen to {p. 111} know about this case personally. Marvin Miles--he's an aviation writer in Los Angeles--was down at White Sands Proving Ground some time ago. He talked with a Navy rocket expert who was in charge of naval guided-missile projects. This Navy man--he's a commander in the regular service--told Miles they'd seen four saucers down in that area." "You're sure he wasn't kidding Miles?" I said. Then I remembered Purdy's tip about a White Sands case. "I told you I checked on this myself," Redell said, a little annoyed. "After Miles told me about it, I asked an engineer who'd been down there if it was true. He gave me the same story, figures and all. The first saucer was tracked by White Sands observers with a theodolite. Then they worked out its performance with ballistics formulas." Redell looked at me grimly. "The thing was about fifty miles up. And it was making over fifteen thousand miles an hour!" One of the witnesses, said Redell, was a well-known scientist from the General Mills aeronautical research laboratory in Minneapolis, which was working with the Navy. (A few days later, I verified this fact and the basic details of Redell's account. But it was not until early in January 1950 that I finally identified the officer as Commander Robert B. McLaughlin and got his dramatic story.) "Here are two more items Miles told me," Redell went on. "This Navy expert said the saucer actually looked elliptical, or egg-shaped. And while it was being tracked it suddenly made a steep climb--so steep no human being could have lived through it." "One thing is certain," I said. "That fifty-mile altitude knocks out the rotating disk. Up in that thin air it wouldn't have any lift." "Right," said Redell. "And the variable jet type would require an enormous amount of fuel. Regardless, those G's mean it couldn't have had any pilot born on this earth." According to Marvin Miles, this White Sands saucer had been over a hundred feet long. (Later, Commander {p. 112} McLaughlin stated that it was 105 feet.) If this were an American device, then it meant that we had already licked many of the problems on which the Earth Satellite Vehicle designers were supposed to be just starting. Their statements, then, would have to be false--part of an elaborate cover-up. "If we had such an advanced design," said Redell, "and I just don't believe it possible--would we gamble on a remote-control system? No such system is perfect. Suppose it went wrong. At that speed, over fifteen thousand miles an hour, your precious missile or strato ship could be halfway around the globe in about forty-five minutes. That is, if the fuel held out. Before you could regain control, you might lose it in the sea. Or it might come down behind the Iron Curtain. Even if it were I smashed to bits, it would tip off the Soviets. They might claim it was a guided-missile attack. Almost anything could hap pen." "It could have a time bomb in it," I suggested. "if it got off course or out of control, it would blow itself up." Redell emphatically shook his head. "I've heard that idea before, but it won't hold up. What if your ship's controls went haywire and the thing blew up over a crowded city? Imagine the panic, even if no actual damage was done. No, sir--nobody in his right mind is going to let a huge ship like that go barging around unpiloted. It would be criminal negligence. "If the White Sands calculations were correct, then this particular saucer was no earth-made device. Perhaps in coming years, we could produce such a ship, with atomic power to drive it. But not now." Redell went over several other cases. "Take the Godman Field saucer. At one time, it was seen at places one hundred and seventy-five miles apart, as you know. Even to have been seen at all from both places, it would. have to have been huge--much larger than two hundred and fifty feet in diameter. The human eye wouldn't resolve an object that size, at such a distance and height." It was an odd thing; I had, gone over the Mantell case {p. 113} a dozen times. I knew the object was huge. But I had never tried to figure out the object's exact size. "How big do you think it was?" I asked quickly. This could be the key I had tried to find. "I haven't worked it out," said Redell. "But I can give you a rough idea. The human eye can't resolve any object that subtends less than three minutes of arc. For instance, a plane with a hundred-foot wing span would only be a speck twenty miles away, if you saw it at all." "But this thing was seen clearly eighty-seven miles away--or even more, if it wasn't midway between the two cities. Why, it would have to be a thousand feet in diameter." "Even larger." Redell was silent a moment. "What was the word Mantell used--'tremendous'?" I tried to visualize the thing, but my mind balked. One thing was certain now. It was utterly impossible that any nation on earth could have built such an enormous airborne machine. just to think of the force required to hold it in the sky was enough to stagger any engineer. We were years away--perhaps centuries--from any such possibility. As if he had read my thoughts, Redell said soberly, "There's no other possible answer. It was a huge space ship--perhaps the largest ever to come into our atmosphere." It was clear now why such desperate efforts had been made to explain away the object Mantell had chased. "What about that Eastern Airlines sighting?" I asked. "Well, first," said Redell, "it wasn't any remote-control guided missile. I'll say it again; it would be sheer insanity. Suppose that thing had crashed in Macon. At that speed it could have plowed its way for blocks, right through the buildings. It could have killed hundreds of people, burned the heart out of the city. "If it was a missile, or some hush-hush experimental job, then it was piloted. But they don't test a job like that on any commercial airways. And they don't fool around at five thousand feet where people will see the thing streaking by and call the newspapers. "To power a hundred-foot wingless ship, especially at those speeds, would take enormous force. Not as much {p. 114} as a V-two rocket, but tremendous power. The fuel load would be terrific. Certainly, the pilot wouldn't be circling around Georgia and Alabama for an hour, buzzing airliners. I'll stake everything that we couldn't duplicate that space ship's performance for less than fifty million dollars. It would take something brand-new in jets." Redell paused. He looked at me grimly. "And the way I'd have to soup it up, it would be a damned dangerous ship to fly. No pilot would deliberately fly it that low. He'd stay up where he'd have a chance to bail out." I told him what I had heard about the blueprints the Air Force was said to have rushed. "Of course they were worried," said Redell. "And probably they still are. But I don't think they need be; so far, there's been nothing menacing about these space ships." When I got him back to the Gorman case, Redell drew a sketch on his pad, showing me his idea of the disk light. He estimated the transparent rim as not more than five feet in diameter. "Possibly smaller," he said. "You recall that Gorman said the light was between six and eight inches in diameter. He also said it seemed to have depth--that was in the Air Force report." "You think all the mechanism was hidden by the light?" "Only possible answer," said Redell. "But just try to imagine crowding a motor, or jet controls for rim jets, along with remote controls and a television device, in that small space. Plus your fuel supply. I don't know any engineer who would even attempt it. To carry that much gear, it would take a fair-sized plane. You could make a disk large enough, but the mechanism and fuel section would be two or three feet across, at least. So Gorman's light must have been powered and controlled by some unique means. The same principle applies to all the other light reports I've heard. No shape behind them, high speed, and intelligent maneuvers. That thing was guided from some interplanetary ship, hovering at a high altitude," Redell declared. "But I haven't any idea what source of power it used." {p. 115} Until then, I had forgotten about Art Green's letter. I told Redell what Art had said about the Geiger counter. "I knew they went over Gorman's fighter with a Geiger counter," Redell commented. "But they said the reaction was negative. If Green is right, it's interesting. It would mean they have built incredibly small atomic engines. But with a race so many years ahead of us, it shouldn't be surprising. Of course, they may also be using some other kind of power our scientists say is impossible." I was about to ask him what he meant when his secretary came in. "Mr. Carson is waiting," she told Redell. "He had a four-o'clock appointment." As I started to leave, Redell looked at his calendar. "I hate to break this up; it's a fascinating business What about coming in Friday? I'd like to see the rest of those case reports." "Fine," I said. "I've got a few more questions, too." Going out, I made a mental note of the Friday date. Then the figure clicked; it was just three months since I'd started on this assignment. Three months ago. At that time I'd only been half sure that the saucers were real. If anyone had said I'd soon believe they were space ships, I'd have told him he was crazy. {p. 116} CHAPTER XIII BEFORE my date with Redell, I went over all the material I had, hoping to find some clue to the space visitors' planet. It was possible, of course, that there was more than one planet involved. Project "Saucer" had discussed the possibilities in it! report of April 27, 1949. I read over this section again: Since flying saucers first hit the headlines almost two years ago, there has been wide speculation that the aerial phenomena might actually be some form of penetration from another planet. Actually, astronomers are largely in agreement that only one member of the solar system beside Earth is capable of supporting life. That is Mars. Even Mars, however, appears to be relatively desolate and inhospitable, so that a Martian race would be more occupied with survival than we are on Earth. On Mars, there exists an excessively slow loss of atmosphere, oxygen and water, against which intelligent beings, if they do exist there, may have protected themselves by scientific control of physical conditions. This might have been done, scientists speculate, by the construction of homes and cities underground where the atmospheric pressure would be greater and thus temperature extremes reduced. The other possibilities exist, of course, that evolution may have developed a being who can withstand the rigors of the Martian climate, or that the race--if it ever did exist--has perished. In other words, the existence of intelligent life on Mars, where the rare atmosphere is nearly devoid of oxygen and water and where the nights are much colder than our Arctic winters, is not impossible but is completely unproven. The possibility of intelligent life also existing on the planet Venus is not considered completely unreasonable {p. 117} by astronomers. The atmosphere of Venus apparently consists mostly of carbon dioxide with deep clouds of formaldehyde droplets, and there seems to be little or no water. Yet, scientists concede that living organisms might develop in chemical environments which are strange to us. Venus, however, has two handicaps. Her mass and gravity are nearly as large as the Earth (Mars is smaller) and her cloudy atmosphere would discourage astronomy, hence space travel. The last argument, I thought, did not have too much weight. We were planning to escape the earth's gravity; Martians could do the same, with their planet. As for the cloudy atmosphere, they could have developed some system of radio or radar investigation of the universe. The Navy research units, I knew, were probing the far-off Crab nebula in the Milky Way with special radio devices. This same method, or something far superior, could have been developed on Venus, or other planets surrounded by constant clouds. After the discussion of solar-system planets, the Project "Saucer" report went on to other star systems: Outside the solar system other stars--22 in number--have satellite planets. Our sun has nine. One of these, the Earth, is ideal for existence of intelligent life. On two others there is a possibility of life. Therefore, astronomers believe reasonable the thesis that there could be at least one ideally habitable planet for each of the 22 other eligible stars. (After publication of our findings in True, several astronomers said that many planets may be inhabited. One of these was Dr. Carl F. von Weizacker, noted University of Chicago physicist. On January 10, 1950, Dr. von Weizacker stated: "Billions upon billions of stars found in the heavens may each have their own planets revolving about them. It is possible that these planets would have plant and animal life on them similar to the earth's.") {p. 118} After narrowing the eligible stars down to twenty-two the Project "Saucer" report goes on: The theory is also employed that man represents the average in advancement and development. Therefore, one-half the other habitable planets would be behind man in development, and the other half ahead. It is also assumed that any visiting race could be expected to be far in advance of man. Thus, the chance of space travelers existing at planets attached to neighboring stars is very much greater than the chance of space-traveling Martians. The one can be viewed as almost a certainty (if you accept the thesis that the number of inhabited planets is equal to those that are suitable for life and that intelligent life is not peculiar to the Earth) ." The most likely star was Wolf 359--eight light-years away. I thought for a minute about traveling that vast distance. It was almost appalling, considered in terms of man's life span. Of course, dwellers on other planets might live much longer. If the speed of light was not an absolute limit, almost any space journey would then be possible. Since there would be no resistance in outer space, it would be simply a matter of using rocket power in the first stages to accelerate to the maximum speed desired. In the latter phase, the rocket's drive would have to be reversed, to decelerate for the landing. The night before my appointment with Redell, I was checking a case report when the phone rang. It was John Steele. "Are you still working on the saucers?" he asked. "If you are, I have a suggestion--something that might be a real lead." "I could use a lead right now," I told him. "I can't give you the source, but it's one I consider reliable," said Steele. "This man says the disks are British developments." This was a new one. I hadn't considered the British. Steele talked for over half an hour, expanding the idea. {p. 119} The saucers, his informant said, were rotating disks with cambered surfaces--originally a Nazi device. Near the end of the war, the British had seized all the models, along with the German technicians and scientists who had worked on the project. The first British types had been developed secretly in England, according to this account. But the first tests showed a dangerous lack of control; the disks streaked up to high altitudes, hurtling without direction. Some had been seen over the Atlantic, some in Turkey, Spain, and other parts of Europe. The British then had shifted operations to Australia, where a guided-missile test range had been set up. (This part, I knew, could be true; there was such a range.) After improving their remote-control system, which used both radio and radar, they had built disks up to a hundred feet in diameter. These were launched out over the Pacific, the first ones straight eastward over open sea. British destroyers were stationed at 100-mile and later 500-mile intervals, to track the missiles by radar and correct their courses. At a set time, when their fuel was almost exhausted, the disks came down vertically and landed in the ocean. Since part of the device was sealed, the disks would float; then a special launching ship would hoist them abroad, refuel them, and launch them back toward a remote base in Australia, where they were landed by remote control. Since then, Steele said, the disks' range and speed had been greatly increased. The first tests of the new disks was in the spring of 1947, his informant had told him. The British had rushed the project, because of Soviet Russia's menacing attitude. Their only defense in England, the British knew, would be some powerful guided missile that could destroy Soviet bases after the first attack. In order to check the range and speeds accurately, it was necessary to have observers in the Western Hemisphere--the disks were now traversing the Pacific. The ideal test range, the British decided, was one extending over Canada, where the disks could be tracked and even landed, {p. 120} If the account was right, said Steele, a base had been set up in the desolate Hudson Bay country. Special radar-tracking stations had also been established, to guide the missiles toward Australia and vessels at sea. These stations also helped to bring in missiles from Australia. Some of the disk missiles were supposed to have been launched from a British island in the South Pacific; others came all the way from Australia. Still others were believed to have been launched by a mother ship stationed between the Galapagos Islands and Pitcairn. It was these new disks that had been seen in the United States, Alaska, Canada, and Latin America, Steele's informant had told him. At first, the sightings were due to imperfect controls; the disks sometimes failed to keep their altitude, partly because of conflicting radio and radar beams from the countries below. Responding to some of these mixed signals, Steele said, the disks had been known to reverse course, hover or descend over radar and radio stations, or circle around at high speeds until their own control system picked them up again. For this reason, the British had arranged a simple detonator system, operated either by remote control or automatically under certain conditions. In this way, no disk would crash over land, with the danger of hitting a populated area. If it descended below a certain altitude, the disk would automatically speed up its rotation, then explode at a high altitude. When radar trackers saw that a disk was off course and could not be realigned, the nearest station then sent a special signal to activate the detonator system. This was always done, Steele had been told, when a disk headed toward Siberia; there had previously been a few cases when Australian-launched disks had got away from controllers and appeared over Europe. I listened to Steele's account with mixed astonishment and suspicion. It sounded like a pipe dream; but if it was, it had been carefully thought out, especially the details that followed. At first, Steele said, American defense officials had been completely baffled by the disk reports. Then the British, learning about the sightings, had hastily explained to top-level American officials. An agreement had been {p. 121} worked out. We were to have the benefit of their research and testing and working models, in return for helping to conceal the secret. We were also to aid in tracking and controlling the missiles when they passed over this country. "And I gather we paid in other ways," Steele said. "My source says this played a big part in increasing our aid to Britain, including certain atomic secrets." That could make sense. Sharing such a secret would be worth all the money and supplies we had poured into England. If America and Great Britain both had a superior long-range missile, it would be the biggest factor I knew for holding off war. But the long ranges involved in Steele's explanation made the thing incredible. "How are they powered? What fuel do they use?" I asked him. "That's the one thing I couldn't get," said Steele. "This man told me it was the most carefully guarded secret of all. They've tapped a new source of power." "If he means atomic engines," I said, "I don't believe it. I don't think anyone is that far along." "No, no," Steele said earnestly, "he said it wasn't that. And the rest of the story hangs together." Privately, I thought of two or three holes, but I let that go. "If it's British," I said, "do you think we should even hint at it?" "I don't see any harm," Steele answered. "The Russians undoubtedly know the truth. They have agents everywhere. It might do a lot of good for American-British relations. Anyway, it would offset any fear that the saucers are Soviet weapons." "Then you're not worried about that angle any more?" Steele laughed. "No, but it had me going for a while. It was a big relief to find out the disks are British." "What's the disks' ceiling?" I asked, abruptly. "Oh--sixty thousand feet, at least," said Steele. After a moment he added quickly, "That's just a guess--they probably operate much higher. I didn't think to ask." Before I hung up, he asked me what I thought, of the British explanation. {p. 122} "It's certainly more plausible than the Soviet idea," I said. I thanked him for calling me, and put down the phone. I was tempted to point out the flaws in his story. But I didn't. If he was sincere, it would be poor thanks for what he had told me. If he was trying to plant a fake explanation, it wouldn't hurt to let him think I'd swallowed it. When I saw Redell, I told him about Steele. "It does look like an attempt to steer you away from the interplanetary answer," Redell agreed, "though he may be passing on a tip he believes." "You think there could be any truth in the British story?" "Would the British risk a hundred-foot disk crashing in some American city?" said Redell. "No remote control is perfect, and neither is a detonator system. By some freak accident, a disk might come down in a place like Chicago, and then blow up. I just can't see the British--any more than ourselves--letting huge unpiloted missiles go barging around the world, flying along airways and over cities. Certainly, they could have automatic devices to make them veer away from airliners--but what if a circuit failed?" "I go along with that," I said. "I don't say the British don't have some long-range missiles," Redell broke in. "Every big nation has a guided-missile project. But no guided missile on earth can explain the Mantell case and the others we've discussed." I showed him the material I had on the Nazi disk experiments. Redell skimmed through it and nodded. "I can tell you a little more," he said. "Some top Nazi scientists were convinced we were being observed by space visitors. They'd searched all the old reports. Some sighting over Germany set them off about 1940. That's what I was told. I think that's where they first got the idea of trying out oval and circular airfoils. "Up to then, nobody was interested. The rotation idea uses the same principle as the helicopter, but nobody had even followed that through. The Nazis went to work on the disks. They also began to rush space-exploration plans--the orbiting satellite idea. I think they realized these {p. 123} space ships were using some great source of power we hadn't discovered on earth. I believe that's what they were after--that power secret. If they'd succeeded, they'd have owned the world. As it was, that space project caused them to leap ahead of everybody with rockets." When I asked Redell how he thought the space ships were powered, he shrugged. "Probably cosmic rays hold the answer. Their power would be even greater than atomic power. There's another source I've heard mentioned, but most people scoff at it. That's the use of electromagnetic fields in space. The earth has its magnetic field, of course, and so does the sun. Probably all planets do. "There's a man named Fernand Roussel who wrote a book called The Unifying Principle of Physical Phenomena, about 1943. He goes into the electromagnetic-field theory. If he's right, then there must be some way to tap this force and go from one planet to another without using any fuel. You'd use your first planet's magnetic field to start you off and then coast through space until you got into the field of the next planet. At least, that's how I understand it. But you'd be safer sticking to atomic power. That's been proved." Most of our conversations had been keyed to the technical side of the flying-saucer problem. But before I left this time, I asked Redell how the thought of space visitors affected him. "Oh, at first I had a queer feeling about it," he answered. "But once you accept it, it's like anything else. You get used to the idea." "One thing bothers me," I said. "When I try to picture them, I keep remembering the crazy-looking things in some of the comics. What do you suppose they're really like?" "I've thought about it for months." Redell slowly shook his head. "I haven't the slightest idea." {p. 124} CHAPTER XIV THAT EVENING, after my talk with Redell, the question kept coming back in my mind. What were they like? And what were they doing here? From the long record of sightings, it was possible to get an answer to the second question. Observation of the earth followed a general pattern. According to the reports, Europe, the most populated area, had been more closely observed than the rest of the globe until about 1870. By this time, the United States, beginning to rival Europe in industrial progress, had evidently become of interest to the space-ship crews. From then on, Europe and the Western Hemisphere, chiefly North America, shared the observers' attention. The few sightings reported at other points around the world indicate an occasional check-up on the earth in general. Apparently World War I had not greatly concerned the space observers. One reason might be that our aerial operations were still at a relatively low altitude. But World War II had drawn more attention, and this had obviously increased from 1947 up to the present time. Our atomic-bomb explosions and the V-2 high-altitude experiments might be only coincidence, but I could think of no other development that might seriously concern dwellers on other planets. It was a strange thing to think of some far-off race keeping track of the earth's progress. If Redell was right, it might even have started in prehistoric time; a brief survey, perhaps once a century or even further spaced, then gradually more frequent observation as cities appeared on the earth. Somewhere on a distant planet there would be records of that long survey. I wondered how our development would appear to that far-advanced race. They would have seen the slow sailing ships, the first steamships, the lines of steel tracks that carried our first trains. Watching for our first aircraft, they would see the drifting balloons that seemed an aerial miracle when the {p. 125} Montgolfiers first succeeded. More than a century later, they would have noted the slow, clumsy airplanes of the early 1900's. From our gradual progress to the big planes and bombers of today, they could probably chart our next steps toward the stratosphere--and then space. During the last two centuries, they would have watched a dozen wars, each one fiercer than the last, spreading over the globe. Adding up all the things they had seen, they could draw an accurate picture of man, the earth creature, and the increasingly fierce struggle between the earth races. The long survey held no sign of menace. If there had been a guiding purpose of attack and destruction, it could have been carried out years ago. It was almost certain that any planet race able to traverse space would have the means for attack. More than once, during this investigation, I had been asked: "If the saucers are interplanetary, why haven't they landed here? Why haven't their crews tried to make contact with us?" There was always the possibility that the planet race or races could not survive on earth, or that their communications did not include the methods that we used. But I found that hard to believe. Such a superior race would certainly be able to master our radio operations, or anything else that we had developed, in a fairly short time. And it should be equally simple to devise some means of survival on earth, just as we were already planning special suits and helmets for existence on the moon. During a talk with a former Intelligence officer, I got a key to the probable explanation. "Why don't you just reverse it--list what we intend to do when we start exploring space? That'll give you the approximate picture of what visitors to the earth would be doing." Naturally, all the details of space plans have not been worked out, but the general plan is clear. After the first successful earth satellites, we will either attempt a space base farther out or else launch a moon rocket. Probably many round trips to the moon will be made before going farther in space. {p. 126} Which planet will be explored first, after the moon? According to Air Force reports, it is almost a certainty that planets outside the solar system are inhabited. But because of the vast distances involved, expeditions to our neighboring planets may be tried before the more formidable journeys. More than one prominent astronomer believes that life, entirely different from our own, may exist on some solar planets. Besides Mars, Jupiter, and Venus, there are five more that, like the earth, revolve around the sun. One of the prominent authorities is Dr. H. Spencer Jones, Astronomer Royal. In his book Life on Other Worlds, Dr. Jones points out that everything about us is the result of changing processes, begun millenniums ago and still going on. We cannot define life solely in our own terms; it can exist in unfamiliar forms. "It is conceivable," Dr. Jones states in his book, "that we could have beings, the cells of whose bodies contained silicon instead of the carbon which is an essential constituent of our cells and of all other living cells on the earth. And that because of this essential difference between the constitution of those cells and the cells of which animal and plant life on the earth are built up, they might be able to exist at temperatures so high that no terrestrial types of life could survive." According to Dr. Jones, then, life could be possible on worlds hotter and drier than ours; it could also exist on a very much colder one, such as Mars. Even if a survey of the sun's planets proved fruitless, it would decide the question of their being populated. Also, it would provide valuable experience for the much longer journeys into space. No one expects such a survey until we have a space vehicle able to make the round trip. One-way trips would tell us nothing, even if volunteers offered to make such suicidal journeys. The most probable step will be to launch a space vehicle equipped with supplies for a long time, perhaps a year or two, within the solar system. Since Mars has been frequently mentioned as a source of the flying {p. 127} saucers, let's assume it would be the first solar-system planet to be explored from the earth. As the space ship neared Mars, it could be turned to circle the planet in an orbit, just like our planned earth satellite vehicle. Once in this orbit, it could circle indefinitely without using fuel except to correct its course. From this space base, unmanned remote-control "observer" units with television "eyes" or other transmitters would be sent down to survey the planet at close range. If it then seemed fairly safe, a manned unit could be released to make a more thorough check-up. Such preliminary caution would be imperative. Our explorers would have no idea of what awaited them. The planet might be uninhabited. It might be peopled by a fiercely barbarous race unaware of civilization as we know it. Or it might have a civilization far in advance of ours. The explorers would first try to get a general idea of the whole planet. Then they would attempt to examine the most densely populated areas, types of armature, any aircraft likely to attack them. Combing the radio spectrum, they would pick up and record sounds and signals in order to decipher the language. As on earth, they might hear a hodgepodge of tongues. The next step would be to select the most technically advanced nation, listen in, and try to learn its language, or record it for deciphering afterward on earth. Our astronomers already have analyzed Mars's atmosphere, but the explorers would have to confirm their reports, to find out whether the atmosphere at the surface would support their lungs if they landed. The easiest way would be to send down manned or unmanned units with special apparatus to scoop in atmosphere samples. Later analysis would tell whether earthlings would need oxygen-helmet suits such as we plan to use on the moon. But before risking flight at such low altitudes, the explorers would first learn everything possible about the planet's aircraft, if any. They would try to determine their top ceiling, maximum speed, maneuverability, and if possible their weapons. Mitch of this could be done by sending down remote-control "observer" disks, or {p. 128} whatever type we decide to use. A manned unit might make a survey at night, or in daytime with clouds nearby to shield it. By hovering over the planet's aircraft bases, the explorers could get most of the picture, and also decide whether the bases were suitable for their own use later. It might even be necessary to lure some Martian aircraft into pursuit of our units, to find out their performance. But our explorers would above all avoid any sign of hostility; they would hastily. withdraw to show they had no warlike intentions. If the appearance of our observer units and manned craft caused too violent reactions on the planet, the explorers would withdraw to their orbiting space vehicle and either wait for a lull or else start the long trip back home. Another interplanetary craft from the earth might take its place later to resume periodic surveys. In this way, a vast amount of information could be collected without once making contact with the strange race. If they seemed belligerent or uncivilized, we would probably end our survey and check on the next possibly inhabited planet. If we found they were highly civilized, we would undoubtedly attempt later contact. But it might take a long time, decades of observation and analysis, before we were ready for that final step. We might find a civilization not quite so advanced as ours. It might not yet have developed radio and television. We would then have no way of getting a detailed picture, learning the languages, or communicating with. the Martians. Analysis of their atmosphere might show a great hazard to earthlings, one making it impossible to land or requiring years of research to overcome. There might be other obstacles beyond our present understanding. This same procedure would apply to the rest of the solar-system planets and to more distant systems. Since Wolf 359 is the nearest star outside our system that is likely to have inhabited planets, one of these planets would probably be listed as the first to explore in far-distant space. It would be a tremendous undertaking, unless the speed of light can be exceeded in space. Since {p. 129} Wolf 359 is eight light-years from the earth, even if a space ship traveled at the theoretical maximum--just under 186,00 miles a second--it would take over sixteen years for the round trip. Detailed observation of the planet would add to this period. If we assume half that speed--which would still be an incredible attainment with our present knowledge--our space explorers would have to dedicate at least thirty-two years to the hazardous, lonely round trip. However, there has never been a lack of volunteers for grand undertakings in the history of man. It is quite possible that in our survey of the solar-system planets we would find some inhabited, but not advanced enough to be of interest to us. Periodically, we might make return visits to note their progress. Meantime, our astronomers would watch these planets, probably developing new, higher powered telescopes for the purpose, to detect any signs of unusual activity. Any tremendous explosion on a planet would immediately concern us. Such an explosion, on Mars, was reported by astronomers on January 16, 1950. The cause and general effects are still being debated. Sadao Saeki, the Japanese astronomer who first reported it at Osaka, believes it was of volcanic nature. The explosion created a cloud over an area about seven hundred miles in diameter and forty miles high. It was dull gray with a yellowish tinge and a different color from the atmospheric phenomena customarily seen near Mars. Saeki believes the blast might have destroyed any form of life existing on the planet, but even though the telescopic camera recorded a violent explosion, other authorities do not believe the planet was wrecked. The canals first discovered on Mars by Giovanni Schiaparelli, about 1877, are still apparent on photographs. Mars is now being carefully watched by astronomers. If there are more of the strange explosions, the planet will be scanned constantly for some clue to their nature. If a mysterious explosion on Mars, or any other planet, were found of atomic origin, it would cause serious concern on earth. Suppose for a moment that it happened many years from now, when we will have succeeded in {p. 130} space explorations. At this time, let us assume our explorers have found that Mars is experimenting with high-altitude rockets; some of them have been seen, rising at tremendous speed, in the upper atmosphere of Mars. Then comes this violent explosion. A scientific analysis of the cloud by astrophysicists here on earth proves it was of atomic origin. The first reaction would undoubtedly be an immediate resurvey of Mars. As quickly as possible, we would establish an orbiting space base--out of range of Martian rockets--and try to find how far they had advanced with atomic bombs. Samples of the Martian atmosphere would be collected and analyzed for telltale radiation. Observer units would be flown over the planet, with instruments to locate atom-bomb plants and possibly uranium deposits. The rocket-launching bases would also come under close observation. We would try to learn how close the scientists were to escaping the pull of gravity. Since Mars's gravity is much less than the earth's, the Martians would not have so far to progress before succeeding in space travel. The detailed survey by our space-base observers would probably show that there was no immediate danger to the earth. It might take one hundred years--perhaps five hundred--before the Martians could be a problem. Eventually, the time would come when Mars would send out space-ship explorers. They would undoubtedly discover that the earth was populated with a technically advanced civilization. Any warlike ideas they had in mind could be quickly ended by a show of our superior space craft and our own atomic weapons--probably far superior to any on Mars. It might even be possible that by then we would have finally outlawed war; if so, a promise to share the peaceful benefits of our technical knowledge might be enough to bring Martian leaders into line. Regardless of our final decision, we would certainly keep a lose watch on Mars--or any other planet that seemed a possible threat. Now, if our space-exploration program is just reversed, it will give a reasonable picture of how visitors from {p. 131} space might go about investigating the earth. Such an investigation would tie in with the general pattern of authentic flying-saucer reports: 1. World-wide sightings at long intervals up to the middle of the nineteenth century. 2. Concentration on Europe, as the most advanced section of the globe, until late in the nineteenth century. 3. Frequent surveys of America in the latter part of the nineteenth century, as we began to develop industrially, with cities springing up across the land. 4. Periodic surveys of both America and Europe during the gradual development of aircraft, from the early 1900's up to World War II. 5. An increase of observation during World War II, after German V-2's were launched up into the stratosphere. 6. A steadily increasing survey after our atomic-bomb explosions in New Mexico, Japan, Bikini, and Eniwetok. 7. A second spurt of observations following atom-bomb explosions in Soviet Russia. 8. Continuing observations of the earth at regular intervals, with most attention concentrated on the United States, the present leader in atomic weapons. (Saucers have been reported seen over the Soviet Union, but the number is unknown. There is some evidence that Russia has an investigative unit similar to Project "Saucer.") There are other points of similarity to the program of American space exploration that I have outlined. Most of the extremely large saucers have been at high altitudes, some of them many miles above the earth. At that height, a space ship would be in no danger from our planes and antiaircraft guns and rockets. The smaller disks and the mystery lights have been seen at low altitudes. Occasionally a larger saucer has been seen to approach the earth briefly, as at Lockbourne Air Force Base, at Bethel, Alabama, at Macon and Montgomery, and other places. It has been suggested that this was for the purpose of securing atmospheric samples. It could also be to afford personal observation by the crews. The numerous small disks seen in the first part of {p. 132} the scare, in 1947, fit the pattern for preliminary and close observation by remote-controlled observer units. As the scare increased, the daytime sightings decreased for a while, and mystery lights began to be seen more often. This apparent desire to avoid unfavorable attention could have been caused by our pilots' repeated attempts to chase the strange flying objects. Authentic reports have described sightings; over the following Air Force bases: Chanute, Newark, Andrews, Hickam, Robbins, Godman, Clark, Fairfield Suisan, Davis-Monthan, Harmon, Wright-Patterson, Holloman, Clinton County Air Force Base, and air bases in Alaska, Germany, and the Azores. Saucers have also been sighted over naval air stations at Dallas, Alameda, and Key West, and from the station at Seattle. They have been reported maneuvering over the White Sands Proving Ground, over areas containing atomic developments, above the Muroc Air Base testing area, and over the super-secret research base near Albuquerque. Several times saucers have paced both military and civil aircraft; their actions strongly indicate deliberate encounters to learn our planes' speed and performance. It seems obvious that both the planes and the bases were being observed, and in some cases photographed by remote-control units or manned space ships. Although I thought it improbable that the location of our uranium deposits would be of interest to space men, a Washington official told me it would be relatively simple to detect the ore areas with airborne instruments. "The Geological Survey has already developed special Geiger counters for planes," he told me. "They had a little trouble from cosmic-ray noise. They finally had to cover the Geigers with lead shields. Whenever an important amount of radiation is present in the ground, the plane crew gets a signal, and they spot the place on their map. It's a quick way of locating valuable deposits." When I told him what I had in mind, he suggested an angle I had not considered. "Mind you," he said, "I'm not completely sold on the interplanetary answer. But assuming it's correct that we're being observed, I can think of a stronger reason {p. 133} than fear of some distant attack. Some atomic scientists say that a super-atomic bomb, or several set off at once, could knock the earth out of its orbit. It sounds fantastic, but so is the A-bomb. It's just possible that some solar-planet race discovered the dangers long ago. They would have good reason to worry if they found we were on that same track. There may be some other atomic weapon we don't suspect, even worse than the A-bomb, one that could destroy the earth and seriously affect other planets." At the time, I thought this was just idle speculation. But since then, several atomic scientists have confirmed this official's suggestion. One of these was Dr. Paul Elliott, a nuclear physicist who worked on the A-bomb during the war. According to Dr. Elliott, if several hydrogen bombs were exploded simultaneously at a high altitude, it could speed up the earth's rotation or change its orbit. He based his statement on the rate of energy the earth receives from the sun, a rate equal to some four pounds of hydrogen exploded every second. Still other atomic scientists have said that H-bomb explosions might even knock a large chunk out of the earth, with unpredictable results. A dramatic picture of what might happen if the earth were forced far out of its orbit is indicated in the much-discussed book Worlds in Collision, by Dr. Immanuel Velikovsky, recently published by Macmillan. After many years of research, Dr. Velikovsky presents strong evidence that the planet Venus, when still a comet resulting from eruption from a larger planet, moved erratically about the sky and violently disturbed both the earth and Mars. When the comet approached the earth, our planet was forced out of its orbit, according to Worlds in Collision. For a time, the world was on the brink of destruction. Quoting many authentic ancient records, including the Quiché manuscript of the Mayas, the Ipuwer papyrus of the Egyptians, and the Visiddhi-Magga of the Buddhists, Dr. Velikovsky describes the cataclysm that took place. "The face of the earth changed," he writes in his book. The details, reinforced by the Zend-Avesta of the Persians, tell of tremendous hurricanes, of a major upheaval {p. 134} in the earth's surface, of oceans rushing over many parts of the land, while rivers were driven from their beds. Some of the events in this period are mentioned in the Bible. Professor Horace M. Kallen, former dean of the New School of Social Research, strongly endorses Dr. Velikovsky's statements: "It is my belief that Velikovsky has supported his theses with substantial evidence and made an effective and persuasive argument." Many other authorities endorse this work, which is documented with impressive references. But even if this particular account is not accepted, all astronomers agree that the effect of a comet passing near the earth would be appalling. Worlds in Collision states that Mars, like the earth, was pulled out of its orbit by the comet's erratic passage. It may be that this near disaster to the earth and Mars is known on other solar planets, or remembered on Mars itself, if the planet is inhabited. The possibility of super-bomb explosions on the earth understandably disturb any dwellers on other solar-system planets. This may be what was back of the Project "Saucer" statement on the probable motives of any visitors from space. I mentioned this Air Force statement in an earlier chapter, but it may be of interest to repeat it at this time. The comment appeared in a confidential analysis of Intelligence reports, in the formerly secret Project "Saucer" document, "Report on Unidentified Aerial and Celestial Objects." It reads as follows: "Such a civilization might observe that on earth we now have atomic bombs and are fast developing rockets. In view of the past history of mankind, they should be alarmed. We should therefore expect at this time above all to behold such visitations. "Since the acts of mankind most easily observed from a distance are A-bomb explosions, we should expect some relation to obtain between the time of the A-bomb explosions, the time at which the space ships are seen, and the time required for such ships to arrive from and return to home base." {p. 135} CHAPTER XV IT was early in October 1949 when I finished the reversal of our space-exploration plans. I spent the next two days running down a sighting report from a town in Pennsylvania. Like three or four other tips that had seemed important at first, it turned out to be a dud. When I got back home, I found Ken Purdy had been trying to reach me. I phoned him at True, and he asked me to fly up to New York the next day. "I've just heard there's another magazine working on the saucer story," he told me. "Who is it?" I said. "I don't know yet. It may be just a rumor, but we can't take a chance. We've got to get this in the January book." That night I gathered up all the material. It looked hopeless to condense it into one article, and I knew that Purdy had even more investigators' reports waiting for me in New York. Flying up the next morning, I suddenly thought of a talk I'd had with an air transport official. It was in Washington; I had just told him about the investigation. "If they are spacemen," he said, "they'd probably have a hard time figuring out this country by listening to our broadcasts. Imagine tuning in soap operas, 'The Lone Ranger,' and a couple of crime yarns, along with newscasts about strikes and murders and the cold war. They might pick up some of those kid programs about rocket ships. A few days of listening to that stuff--well, it would give them one hell of a picture." Except for some hoax reports, this was the first funny suggestion I'd had about the spacemen. But now, thinking seriously about it, I realized he had an important point. It was possible that men from another planet might have to reorient even their way of thinking to understand the earth's ways. It would not be automatic, despite their superior technical progress. Evolution might have produced basic differences in their understanding of life. Humor, for instance, might be totally lacking in their make-up. {p. 136} What would they be like? I'd tried to imagine how they might look, without getting anywhere. Dr. H. Spencer Jones hadn't helped much with his Life on Other Worlds. I couldn't begin to visualize beings with totally different cells, perhaps able to take terrific heat or bitter cold as merely normal weather. There were all kinds of possibilities. If they lived on Mars, for instance, perhaps they couldn't take the heavier gravity of the earth. They might be easily subject to our diseases, especially if they had destroyed disease germs on their planet--a natural step for an advanced race. It was possible, I knew, that the spacemen might look grotesque to us. But I clung to a Stubborn feeling that they would resemble man. That came, of course, from an inborn feeling of man's superiority over all living things. It carried over into a feeling that any thinking, intelligent being, whether on Mars or Wolf 359's planets, should have evolved in the same form. I gave up trying to imagine how the spacemen might look. There was simply nothing to go on. But there were strong indications of how they thought and reacted. Certain qualities were plainly evident. Intelligence . No one could dispute that. It took a high order of mentality to construct and operate a space ship. Courage . It would take brave men to face the hazards of space. Curiosity . Without this quality, they would never have thought to explore far-distant planets. There were other qualities that seemed almost equally certain. These spacemen apparently lacked belligerence; there had been no sign of hostility through all the years. They were seemingly painstaking and extremely methodical. It was still not much of a picture. But somehow, it was encouraging. Glancing down from the plane's window, I thought: How does this look to them? Our farms, our cities, the railroads there below; the highways, with the speeding cars and trucks; the winding river, and far off to the right, the broad stretch of the Atlantic. {p. 137} What would they think of America? Manhattan came into sight, as the pilot let down for the landing. An odd thought popped into my mind. How would a spaceman react if he saw a Broadway show? Not long before, I had seen South Pacific. I could still hear Ezio Pinza's magnificent voice as he sang "Some Enchanted Evening." Was music a part of spacemen's lives, or would it be something new and strange, perhaps completely distasteful? They might live and think on a coldly intelligent level, without a touch of what we know as emotion. To them, our lives might seem meaningless and dull. We ourselves might appear grotesque in form. But in their progress, there must have been struggle, trial and error, some feeling of triumph at success. Surely these would be emotional forces, bound to reflect in the planet races. Perhaps, in spite of some differences, we would find a common bond--the bond of thinking, intelligent creatures trying to better themselves. The airliner landed and taxied in to unload. As I went down the gangway I suddenly realized something. My last vague fear was gone. It had not been a personal fear of the visitors from space. It had been a selfish fear of the impact on my life. I realized that now. It might be a long time before they would try to make contact. But I had a conviction that when it came, it would be a peaceful mission, not an ultimatum. It could even be the means of ending wars on earth. But I had been conditioned to this thing. I had had six months of preparation, six months to go from complete skepticism to slow, final acceptance. What if it had been thrown at me in black headlines? Even a peaceful contact by beings from another planet would profoundly affect the world. The story in True might play an important part in that final effect. Carefully done, it could help prepare Americans for the official disclosure. But if it weren't done right, we might be opening a Pandora's box. {p. 138} CHAPTER XVI THAT MORNING, at True, we made the final decisions on how to handle the story. Using the evidence of the Mantell case, the Chiles-Whitted report, Gorman's mystery-light encounter, and other authentic cases, along with the records of early sightings, we would state our main conclusion: that the flying saucers were interplanetary. In going over the mass of reports, Purdy and I both realized that a few sightings did not fit the space-observer pattern. Most of these reports came from the southwest states, where guided-missile experiments were going on. Purdy agreed with Paul Redell that any long-range tests would be made over the sea or unpopulated areas, with every attempt at secrecy. "They might make short-range tests down there in New Mexico and Arizona-maybe over Texas," he said. "But they'd never risk killing people by shooting the things all over the country." "They've already set up a three-thousand-mile range for the longer runs," I added. "It runs from Florida into the South Atlantic. And the Navy missiles at Point Mugu are launched out over the Pacific. Any guided missiles coming down over settled areas would certainly be an accident. Besides all that, no missile on earth can explain these major cases." Purdy was emphatic about speculating on our guided-missile research. "Suppose you analyzed these minor cases that look like missile tests. You might accidentally give away something important, like their range and speeds. Look what the Russians did with the A-bomb hints Washington let out." It was finally decided that we would briefly mention the guided missiles, along with the fact that the armed services had flatly denied any link with the saucers. "After all, interplanetary travel is the main story," said Purdy. "And the Mantell case alone proves we've {p. 139} been observed from space ships, even without the old records." The question of the story's impact worried both of us. public acceptance of intelligent life on other planets would affect almost every phase of our existence-business, defense planning, philosophy, even religion. Of course, the immediate effect was more important. Personally, I thought that most Americans could take even an official announcement without too much trouble. But I could be wrong. "The only yardstick--and that's not much good--is that 'little men' story," said Purdy. "A lot of people have got excited about it, but they seem more interested than scared." The story of the "little men from Venus" had been circulating for some time. In the usual version, two flying saucers had come down near our southwest border. In the space craft were several oddly dressed men, three feet high. All of them were dead; the cause was usually given as inability to stand our atmosphere. The Air Force was said to have hushed up the story, so that the public could be educated gradually to the truth. Though it had all the earmarks of a well-thought-out hoax, many newspapers had repeated the story. It had even been broadcast as fact on several radio newscasts. But there had been no signs of public alarm. "It looks as if people have come a long way since that Orson Welles scare," I said to Purdy. "But there isn't any menace in this story," he objected. "The crews were reported dead, so everybody got the idea that spacemen couldn't live if they landed. What if a space ship should suddenly come down over a big city--say New York--low enough for millions of people to see it?" "it might cause a stampede," I said, Purdy snorted. "it would be a miracle if it didn't, unless people had been fully prepared. if we do a straight fact piece, just giving the evidence, it will start the ball rolling. People at least will be thinking about it." Before I left for Washington, I told Purdy of my last visit to the Pentagon. I had informed Air Force press {p. 140} relations officials of True's intention to publish the space-travel answer. There had been no attempt to dissuade me. And I had been told once again that there was no security involved; that Project "Saucer" had found nothing threatening the safety of America. At this time I had also asked if Project "Saucer" files were now available. The Wright Field unit, I was told, still was a classified project, both its files and its photographs secret. This had been the first week in October. When I asked if there was any other information on published cases, the answer again was negative. The April 27th report, according to Press Branch officials, was still an accurate statement of Air Force opinions and policies. So far as they knew, no other explanations had be n found for the unidentified saucers. 'I in absolutely convinced now," I told Purdy, "that here's an official policy to let the thing leak out. It explains why Forrestal announced our Earth Satellite Vehicle program, years before we could even start to build it. It also would explain those Project 'Saucer' hints in the April report." "I think we're being used as a trial balloon," Purdy said thoughtfully. "We've let them know what we're doing. If they'd wanted to stop us, the Air Force could easily have done it. All they'd have to do would be call us in, give us the dope off the record, and tell us it was a patriotic duty to keep still. Just the way they did about uranium and atomic experiments during the war." He still did not have the name of the other magazine supposed to be working on the saucers. But it seemed a reliable tip (it later proved to be true), and from then on we worked under high pressure. In writing the article, I used only the most authentic recent sightings; all of the cases were in the Air Force reports. When it came to the Mantell case, I stuck to published estimates of the strange object's size; a mysterious ship 250 to 300 feet in diameter was startling enough. At first, I chose Mars to illustrate our space explorations. But Mars had been associated with the Orson Welles stampede. Most discussions of the planet had a menacing note, perhaps because of its warlike name. {p. 141} In the end, I switched to a planet of Wolf 359. The thought of those eight light-years would have a comforting effect on any nervous readers. The chance of any mass visitation would seem remote, if not impossible. But it would still put across the space-travel story. As finally revised, the article, written under my byline, stated the following points as the conclusions reached by True: 1. For the past 175 years, the earth has been under systematic close-range examination by living, intelligent observers from another planet. 2. The intensity of this observation, and the frequency of the visits to the earth's atmosphere, have increased markedly during the past two years. 3. The vehicles used for this observation and for interplanetary transport by the explorers have been classed as follows: Type I, a small, nonpilot-carrying disk-shaped craft equipped with some form of television or impulse transmitter; Type II, a very large, metallic, disk-shaped aircraft operating on the helicopter principle; Type III, a dirigible-shaped, wingless aircraft that, in the Earth's atmosphere, operates in conformance with the Prandtl theory of lift. 4. The discernible patterns of observation and exploration shown by the so-called flying disks varies in no important particular from well-developed American plans for the exploration of space, expected to come to fruition within the next fifty years. There is reason to believe, however, that some other race of thinking beings is a matter of two and a quarter centuries ahead of us. Following these points, I added a brief comment on the possibility of guided missiles, adding that the Air Force had convincingly denied this as an explanation of any sightings. As Purdy had suggested, I carefully omitted ten minor cases that I thought might be linked with guided-missile research. If disclosing the facts about space travel helped to divert attention from any secret tests, so much the better. "True accepts the official denial of any secret device," I stated, "because the weight of the evidence, especially the world-wide sightings, does not support such a belief." {p. 142} Most readers, of course, would know that some guided-missile experiments were going on, and that True was fully aware of it. But our main purpose would be achieved. The fact that the earth had been observed by beings from another planet would be fully presented. Some readers, of course, would reject even the fact that the saucers existed. Others would cling to the idea that they were of earthly origin. But the mass of evidence would make most readers think. At the very least, it would plant one strong suggestion: that we, men and women of the earth, are not the only intelligent species in the universe. When the article was finished, it was tried out on True's staff, then on a picked group that had not known about the investigation. One editor summed up the average opinion: "It will cause a lot of discussion, but the way it's written, it shouldn't start any panic." The January issue, in which the story ran, was due on the stands shortly after Christmas. With my family, I had gone to Ottumwa, Iowa, to spend the holidays with my mother and sister. While I was there, the story broke unexpectedly on radio networks. Frank Edwards, Mutual network newscaster, led off the radio comment. He was followed by Walter Winchell, Lowell Thomas, Morgan Beatty, and most of the other radio commentators. The wire services quickly picked it up; some papers ran front-page stories. The publicity was far more than I had expected. I phoned a reporter in Washington whose beat includes the Pentagon. "The Air Force is running around in circles," he told me. "They knew your story was due, but nobody thought it would raise such a fuss. I think they're scared of hysteria. They're getting a barrage of wires and telephone calls." That night, as I was packing to rush back east, he called with the latest news. "They're going to deny the whole thing," he said. "But' I heard one Press Branch guy say it might not be enough {p. 143} --they're trying to figure some way to knock it down fast." Next day, while changing trains at Chicago, I saw the Air Force statement. The press release was dated December 27, 1949. Without mentioning True, the Air Force flatly denied having any evidence that flying saucers exist. After examining 375 reports, the release said, Project "Saucer" had found that they were caused by: 1. Misinterpretation of various conventional objects. 2. A mild form of mass hysteria or "war nerves." 3. Individuals who fabricate such reports to perpetrate a hoax or to seek publicity. Evaluation of the reports of unidentified flying objects, said the Air Force, demonstrates that they constitute no direct threat to the national security of the United States. Then came the clincher: Project "Saucer," said the Air Force, had been discontinued, now that all the reports had been explained. It was plain that the release had been hastily prepared. It completely contradicted the detailed Project "Saucer" report, issued eight months before, that had called for constant vigilance, after admitting that most important cases were unsolved. Anyone familiar with the situation would see the discrepancy at once. From Washington I flew to New York, where I found True in a turmoil. Long-distance calls were pouring in. Letters on flying saucers had swamped the mail room. Reporters were hounding Purdy for more information. A hurried analysis of the first hundred letters showed a trend that later mail confirmed. Less than 5 per cent of the readers ridiculed the article. Between 15 and 20 per cent said they were not convinced; a few of these admitted they could not refute the evidence. About half the readers accepted the possibility; most of these said they saw no reason why other planets should not be inhabited. The remainder, between 25 and 30 per cent, said they were completely convinced. Even the disbelievers asked for more information. The intelligence level of the average letter was gratifyingly high. Comments came from scientists, engineers, airline and private pilots, college professors, officers of the armed {p. 144} services, and a wide variety of others--including far more women than True's readership usually includes. Several confidential tips had come in when I arrived. Most of them were from usually reputable sources. We were given evidence that Project "Saucer" was still in operation; since its true code name was not "Saucer," it could be continued without violating the Air Force press release. This same information was received from a dozen sources within the next two weeks. We were also told that there had been 722 cases, instead of 375. Meantime, a number of astronomers had come out with statements, pro and con. One of these was Dr. Dean B. McLaughlin, of the University of Michigan. "No one knows what the saucers are as yet," Dr. McLaughlin said. "They could be anything, and I'm willing to be convinced once the evidence is presented." Dr. Bart J. Bok of Harvard was on the fence: "After all," he said, "all sort of things float around in space. But I'm not convinced the saucers are anything apart from the earth." Another Harvard astronomer, Dr. Armin J. Deutsch, took an oblique poke at True and me. "I don't think anyone--and that includes astronomers--knows enough about them to reach any conclusions." After this came the comment of Dr. Carl F. von Weizacker--that billions of stars may have planets, and many could be inhabited. Within a few days we had a huge stack of clippings, some supporting True, some deriding us. In the midst of all this, I read scientists' comments on Einstein's new unified-field theory, which had been printed about the time True appeared on the stands. A discussion by Lincoln Barnett, author of The Universe and Dr. Einstein, explained the basic premise--that gravitation and electromagnetic force are inseparable. As I read it, I thought of what Redell had said. If gravitation were a manifestation of electromagnetic force, was it possible that an advanced race had found a way--as unique as splitting the atom--to offset gravity and utilize that force? It was during these first tense days that we ran down the White Sands story. This also ended another puzzle-- {p. 145} the identity of the magazine that we had feared might scoop us. The race had been closer than we knew. The editors of a national magazine had learned of Commander McLaughlin and the sightings at White Sands. Two of the staff had carefully investigated the details. Convinced that the report was accurate, they had planned to run the story in an early issue. Since True had appeared first with the space-travel story, the editors agreed to release the McLaughlin report for use in our March issue. The basic facts were in close agreement with what Redell had told me. The ellipsoid-shaped saucer had been tracked at a height of 56 miles, its speed 5 miles per second. This was 18,000 miles per hour, even faster than Redell had said. The strange craft, 105 feet in length, had climbed as swiftly as Marvin Miles had described it--an increase in altitude of about 25 miles in 10 seconds. Commander McLaughlin stated in his article that he was convinced the object was a space ship from another planet, operated by animate, intelligent beings. He also described two small circular objects, about twenty inches in diameter, that streaked up beside a Navy high-altitude missile. After maneuvering around it for a moment, both disks accelerated, passed the fast-moving Navy missile, and disappeared. It is Commander McLaughlin's opinion that the saucers come from Mars. Pointing out that Mars was in a good position to see our surface on July 16, 1945, he believes that the flash of the first A-bomb, at Alamogordo Base, a point not far from White Sands, was caught by powerful telescopes. During the first week of January, I appeared on "We, the People," with Lieutenant George Gorman. When I saw Gorman, before rehearsals, he seemed oddly constrained. I had a feeling that he had been warned about talking freely. During rehearsals, he changed his lines in the script. When the writers argued over a point, Gorman told them: "I can say only what was in my published report--nothing else." {p. 146} The day before the broadcast, a program official told me they had been told to include the Air Force denial in the script. That afternoon I learned that the Air Force planned to monitor the broadcast. Meantime, an A.P. story carried a new Air Force announcement. Formerly secret Project "Saucer" files would be opened to newsmen at the Pentagon, giving the answers to all the saucer reports. Just after my return to Washington, I saw an I.N.S. story that was widely printed. It was an interview with Major Jerry Boggs, a Project "Saucer" Intelligence officer who served as liaison man between Wright Field and the Pentagon. Major Boggs had been asked for specific answers to the Mantell, Chiles-Whitted, and Gorman cases. The answers he gave amazed me. I picked up the phone and called the Air Force Press Branch. After some delay, I was told that Major Boggs was being briefed for assignment to Germany. An interview would be almost impossible. "He wasn't too busy to talk with I.N.S.," I said. "All I want is thirty minutes." Later, Jack Shea, a civilian press official I had known for some time, arranged for the meeting. I was also to talk with General Sory Smith, Deputy Director for Air Information. Major Jesse Stay, a Press Branch officer, took me to General Smith's office for the interview. Both Jesse and Jack Shea, pleasant, obliging chaps who had helped me in the past, tried earnestly to convince me the saucers didn't exist. Jesse was still trying when Major Boggs came in. Boggs looked to be in his twenties, younger than I had expected. He was trim, well built, with a quietly alert face. Two rows of ribbons testified to his wartime service. When Jesse Stay introduced me, Boggs gave me a curiously searching look. It could have been merely his usual way of appraising people he met. But all through our talk, I had a strong feeling that he was on his guard. I had written out some questions, but first I mentioned the I.N.S. story. {p. 147} "Were you quoted correctly on the Mantell case?" I asked. "Yes, I was." Major Boggs looked me squarely in the eye. "Captain Mantell was chasing the planet Venus." It was so incredible that I shook my head. "Major, Venus; was practically invisible that day. We've checked with astronomers. Is that the official Air Force answer?" "Yes, it is," Boggs said. His eyes never left my face. I glanced across at General Sory Smith, then back at the intelligence major. "That's a flat contradiction of Project 'Saucer's' report. Last April, after they had checked for fifteen months, they said positively it was not Venus. It was still unidentified." Boggs said, in a slow, unruffled voice, "They rechecked after that report." "Why did they recheck, after fifteen months?" I asked him. "'They must have gone over those figures long before that, for errors." If my question annoyed him, Boggs gave no sign. There's no other possible answer," he said. "Mantell was chasing Venus." {p. 148} CHAPTER XVII FOR A MOMENT after Boggs's last answer, I had an impulse to end the interview. I had a feeling I was facing a sphinx--a quiet, courteous sphinx in an Air Force uniform. I was sure now why Major Jerry Boggs had been chosen for his job, the all-important connecting link with the project at Wright Field. No one would ever catch this man off guard, no matter what secret was given him to conceal. And it was more than the result of Air Force Intelligence training. His manner, his voice carried conviction. He would have convinced anyone who had not carefully analyzed the Godman Field tragedy. I made one more attempt. "Do the Godman Field witnesses--Colonel Hix and the rest--believe the Venus answer?" "I haven't asked them," said Boggs, "so I couldn't say." "What about the Chiles-Whitted case?" I asked. "You were quoted as saying they saw a meteor--a bolide that exploded in a shower of sparks." "That's right," said Boggs. "And Gorman was chasing a lighted balloon?" Again the Intelligence major nodded. I pointed, out that all three of the cases mentioned had been listed as unidentified in the April report. "They'd had those cases for months," I said. "What new facts did they learn?" Boggs said calmly, "They just made a final analysis, and those were the answers." We looked at each other a moment. Major Boggs patiently waited. I began to realize how a lawyer must feel with an imperturbable witness. And Boggs's unfailing courtesy began to make me embarrassed. "Major," I said, "I hope you'll realize this is not a personal matter. As an Intelligence officer, if you're told to give certain answers--" He smiled for the first time. "That's all right--but I'm {p. 149} not hiding a thing. There's just no such thing as a flying saucer, so far as we've found out." "We've been told," I said, "that Project 'Saucer' isn't closed--that you just changed its code name." "That's not so," Boggs said emphatically. "The contracts are ended, and all personnel transferred to other duty." "Then the announcement wasn't caused by True's article?" Both General Smith and Major Jesse Stay shook their heads quickly. Boggs leaned forward, eyeing me earnestly. "As a matter of fact, we'd finished the investigation months ago--around the end of August, or early in September. We just hadn't got around to announcing it." "Last October," I said, "I was told the investigation was still going on. They said there were no new answers to the cases just mentioned." "The Press Branch hadn't been informed yet," Boggs explained simply. "It seems very strange to me," I said. "In April, the Air Force called for vigilance by the civilian population. It said the project was young, much of its work still under way." Jesse Stay interrupted before Boggs could reply. "Don, the Press Branch will have to take the blame for that. The report wasn't carefully checked. There were several loose statements in it." This was an incredible statement. I was sure Jesse knew it. "But the case reports you quoted came from Wright Field. As of April twenty-seventh, 1949, all the major cases were officially unsolved. Then in August or early September, the whole thing's cleaned up, from what Major Boggs says. That's pretty hard to believe." No one answered that one. Major Boggs was waiting politely for the next question. I picked up my list. The rest of the interview was in straight question-and-answer style: Q. Do you know about the White Sands sightings in April 1948? The ones Commander R. B. McLaughlin has written up? {p. 150} A. Yes, we checked the reports. We just don't believe them. Q. One of the witnesses was Charles B. Moore, the director of the Navy cosmic-ray project at Minneapolis, He's considered a very reputable engineer. Did you know he confirms the first report--the one about the saucer 56 miles up, at a speed of eighteen thousand miles per hour. A. Yes, I knew about him. We think he was mistaken, like the others. Q. Mr. Moore says it was absolutely sure it was not hallucination. He says it should be carefully investigated. A. We did investigate. We just don't believe they saw anything. Q. Could I see the complete file on that case? Also on Mantell, Gorman, and the Eastern Airlines cases? A. That's out of my province. Q. If Project "Saucer" is ended, then all the files should be opened. A. Well, the summaries have been cleared, and you can see them. Q. No, I mean the actual files. Is there any reason I shouldn't see them? A. There'd be a lot of material to search through. Each case has a separate book, and some of them are pretty bulky. Q. There were 722 cases in all, weren't there? A. No, nowhere near that. Q. Then 375 is the total figure--I mean the number of cases Project "Saucer" listed? A. There were a few more--something over four hundred. I don't know the exact figure. Q. I've been told that Project "Saucer" had the Air Force put out a special order for pilots to chase flying saucers. Is that right? A. Yes, that's right. Q. Did that include National Guard pilots? A. Yes, it did. When the project first started checking on saucers we were naturally anxious to get hold of one of the things. We told the pilots to do practically anything in reason, even if they had to grab one by the tail. Q. Were any of those planes armed? {p. 151} A. Only if they happened to have guns for some other mission, like gunnery practice. Q. We've heard of one case where fighters chased a saucer to a high altitude. One of them emptied his guns at it. A. You must mean that New Jersey affair. The plane was armed for another reason. Q. No, I meant a case reported out at Luke Field. Three fighters took off, if the story sent us is correct. Apparently it made quite a commotion. That was back in 1945. A. It might have happened. I don't know. Q. What was this New Jersey case? A. I'd rather not discuss any more cases without having the books here. Q. Has Project "Saucer" released its secret pictures? A. What pictures? There weren't any that amounted to anything. Maybe half a dozen. They didn't show anything, just spots on film or weather balloons at a distance. Q. In the Kenneth Arnold case, didn't some forest rangers verify his report? A. Well, there were some people who claimed they saw the same disks. But we found out later they'd heard about it on the radio. Q. Didn't they draw some sketches that matched Arnold's? A. I never heard about it. Q. I'd like to go back to the Mantell case a second. If Venus was so bright--remember Mantell thought it was a huge metallic object--why didn't the pilot who made the search later on-- A. Well, it was Venus, that's positive. But I can't remember all the details without the case books. Q. One more question, Major. Have any reports been received at Wright Field since Project "Saucer" closed? There was a case after that date, an airliner crew-- At this point, Major Jesse Stay broke in. "It's all up to the local commanders now. If they want to receive reports of anything unusual, all right. And if they want to investigate them, that's up to each {p. 152} commander. But no Project 'Saucer' teams will check on reports. That's all ended." There at the last, it had been a little. like a courtroom scene, and I was glad the interview was over. Major Boggs was unruffled as ever. I apologized for the barrage of questions, and thanked him for being so decent about it. "It was interesting, getting your viewpoint," he said. He smiled, still the courteous sphinx, and went on out. After Bogs had left, I talked with General Smith alone. I told him I was not convinced, "I'd like to see the complete files on these cases I mentioned," I explained. "Also, I'd like to talk with the last commanding officer or senior Intelligence officer attached to Project 'Saucer.'" "I'm not sure about the senior officer," General Smith answered. "He may have been detached already. But I don't see any reason why you can't see those files. I'll phone Wright Field and call you." I was about to leave, but he motioned for me to sit down. "I can understand how you feel about the Mantell report," General Smith said earnestly. "I knew Tommy Mantell very well. And Colonel Hix is a classmate of mine. I knew neither one was the kind to have hallucinations. That case got me, at first." "You believe Venus is the true answer?" I asked him. He seemed surprised. "It must be, if Wright Field says so." When I went back to the Press Branch, I asked Jack Shea for the case-report summaries that Boggs had mentioned, He got them for me--two collections of loose-leaf mimeographed sheets enclosed in black binders. So these were the "secret files"! Across the hall, in the press room, I opened one book at random. The first thing I saw was this: "A meteorologist should compute the approximate energy required to evaporate as much cloud as shown in the incident 26 photographs." Photographs. {p. 153} Major Boggs had said there were no important pictures. I tucked the binders under my arm and went out to my car. Perhaps these books hinted at more than Boggs had realized. But that didn't seem likely. As liaison man, he should know all the answers. I was almost positive that he did. But I was equally sure they weren't the answers he had given me. {p. 154} CHAPTER XVIII THAT NIGHT I went through the Project "Saucer" summary of cases. It was a strange experience. The first report I checked was the Mantell case. Nothing that Boggs had said had changed my firm opinion. I knew the answer was not Venus, and I was certain Boggs knew it, too. The Godman Field incident was listed as Case 33. The report also touches on the Lockbourne Air Base sighting. As already described, the same mysterious object, or a similar one, was seen moving at five hundred miles an hour over Lockbourne Field. It was also sighted at other points in Ohio. The very first sentence in Case 33 showed a determined attempt to explain away the object that Mantell chased: "Detailed attention should be given to any possible astronomical body or phenomenon which might serve to identify the object or objects." (Some of the final Project report on Mantell has been given in an earlier chapter. I am repeating a few paragraphs below, to help in weighing Major Boggs's answer.) These are official statements of the Project astronomer: "On January 7, 1948, Venus was less than half its full brilliance. However, under exceptionally good atmospheric conditions, and with the eye shielded from the direct rays of the sun, Venus might be seen as an exceedingly tiny bright point of light. It is possible to see it in daytime when one knows exactly where to look. Of course, the chances of looking at the right spot are very few. "It has been unofficially reported that the object was a Navy cosmic ray balloon. If this can be established it is to be preferred as an explanation. However, if reports from other localities refer to the same object, any such device must have been a good many miles high--25 to 50--in order to have been seen clearly, almost simultaneously, from places 175 miles apart." {p. 155} This absolutely ruled out the balloon possibility, as the investigator fully realized. That he must have considered the space-ship answer at this point is strongly indicated in the following sentence: "If all reports were of a single object, in the knowledge of this investigator no man-made object could have been large enough and far enough away for the approximate simultaneous sightings." The next paragraph of this Project "Saucer" report practically nullified Major Boggs's statement that Venus was the sole explanation: "It is most unlikely, however, that so many separate persons should at that time have chanced on Venus in the daylight sky. It seems therefore much more probable that more than one object was involved. The sighting might have included two or more balloons (or aircraft) or they might have included Venus (in the fatal chase) and balloons. . . . Such a hypothesis, however, does still necessitate the inclusion of at least two other objects than Venus, and it certainly is coincidental that so many people would have chosen this one day to be confused (to the extent of reporting the matter) by normal airborne objects. . . ." Farther on in the summaries, I found a report that has an extremely significant bearing on the Mantell case. This was Case 175, in which the same consultant attempts to explain a strange daylight sighting at Santa Fe, New Mexico. One of the Santa Fe observers described the mysterious aerial object as round and extremely bright, "like a dime in the sky." Here is what the Project "Saucer" investigator had to say: "The magnitude of Venus was -3.8 (approximately the same as on January 7, 1948). it could have been visible in the daylight sky. It would have appeared, however, more like a pinpoint of brilliant light than 'like a dime in the sky.' It seems unlikely that it would be noticed at all. . . . Considering discrepancies in the two reports, I suggest the moon in a gibbous phase; in daytime this is unusual and most people are not used to it, so that they fail to identify it. While this hypothesis {p. 156} has little to correspond to either report, it is worth mentioning. "It seems far more probable that some type of balloon was the object in this case." Both the Godman Field and the Santa Fe cases were almost identical, so far as the visibility of Venus was concerned. In the Santa Fe case, which had very little publicity, Project "Saucer" dropped the Venus explanation as a practically impossible answer. But in Case 33, it had tried desperately to make Venus loom up as a huge gleaming object during Mantell's fatal chase. There was only one explanation: Project "Saucer" must have known the truth from the start-that Mantell had pursued a tremendous space ship. That fact alone, if it had exploded in the headlines at that time, might have caused dangerous panic. To make it worse, Captain Mantell had been killed. Even if he had actually died from blacking out while trying to follow the swiftly ascending space ship, few would have believed it. The story would spread like wildfire: Spacemen kill an American Air Force Pilot! This explained the tight lid that had been clamped down at once on the Mantell case. It was more than a year before that policy had been changed; then the first official discussions of possible space visitors had begun to appear. True's plans to announce the interplanetary answer would have fitted a program of preparing the people. But the Air Force had not expected such nation-wide reaction from True's article; that much I knew. Evidently, they had not suspected such a detailed analysis of the Godman Field case, in particular. I could see now why Boggs, Jesse Stay, and the others had tried so hard to convince me that we had made a mistake. It was quite possible that we had revived that first Air Force fear of dangerous publicity. But Mantell had been dead for two years. News stories would not have the same impact now, even if they did report that spacemen had downed the pilot. And I doubted that there would be headlines. Unless the Air Force supplied some {p. 157} convincing details, the manner of his death would still be speculation. Apparently I had been right; this case was the key to the riddle. It had been the first major sighting in 1948. Project "Saucer" had been started immediately afterward. In searching for a plausible answer, which could be published if needed, officials had probably set the pattern for handling all other reports, "Explaining away" would be a logical program, until the public could be prepared for an official announcement. As I went through other case reports, I found increasing evidence to back up this belief. Case 1, the Muroc Air Base sightings, had plainly baffled Project men seeking a plausible answer. Because of the Air Force witnesses, they could not ignore the reports. Highly trained Air Force test pilots and ground officers had seen two fast-moving silver-colored disks circling over the base. Flying at speeds of from three to four hundred miles an hour, the disks whirled in amazingly tight maneuvers. Since they were only eight thousand feet above the field, these turns could be clearly seen. "It is tempting to explain the object as ordinary aircraft observed under unusual light conditions," the case report reads. "But the evidence of tight circles, if maintained, is strongly contradictory." Although Case 1 was technically in the "unexplained" group, Wright Field had made a final effort to explain away the reports. Said the Air Materiel Command: "The sightings were the result of misinterpretation of real stimuli, probably research balloons." In all the world's history, there is no record of a three-hundred-mile-an-hour wind. To cover the distance involved, the drifting balloons would have had to move at this speed, or faster. If a three-hundred-mile wind had been blowing at eight thousand feet, nothing on earth could have stood it, Muroc Air Base would have been blown off the map. What did the Muroc test pilots really see that day? While searching for the Chiles-Whitted report, ran across the Fairfield Suisan mystery-light case, which I {p. 158} had learned about in Seattle. This was Case 215. The Project "Saucer" comment reads: "If the observations were exactly as stated by the witnesses, the ball of light could not be a fireball. . . . A fireball would not have come into view at 1,000 feet and risen to 20,000. If correct, there is no astronomical explanation. Under unusual conditions, a fireball might appear to rise somewhat as a result of perspective. The absence of trail and sound definitely does not favor the meteor hypothesis, but . . . does not rule it out finally. It does not seem likely any meteor or auroral phenomenon could be as bright as this." Then came one of the most revealing lines in all the case reports: "In the almost hopeless absence of any other natural explanation, one must consider the possibility of the object's having been a meteor, even though the description does not fit very well." One air-base officer, I recalled, had insisted that the object had been a lighted balloon. Checking the secret report from the Air Weather Service, I found this: "Case 2 15. Very high winds, 60-70 miles per hour from southwest, all levels. Definitely prohibits any balloon from southerly motion." This case is officially listed as answered . In Case 19, where a cigar-shaped object was seen at Dayton, Ohio, the Project investigator made a valiant attempt to fit an answer: "Possibly a close pair of fireballs, but it seems unlikely. If one were to stretch the description to its very limits and make allowances for untrained observers, he could say that the cigar-like shape might have been illusion caused by rapid motion, and that the bright sunlight might have made both the objects and the trails nearly invisible. "This investigator does not prefer that interpolation, and it should he resorted to only if all other possible explanations fail." This case, too, is officially listed as answered . Case 24, which occurred June 12, 1947, twelve days before the Arnold sighting, shows the same determined {p. 159} attempt to find an explanation, no matter how farfetched. In this case, two fast-moving objects were seen at Weiser, Idaho, Twice they approached the earth, then swiftly circled upward. The Project investigator tried hard to prove that these might have been parts of a double fireball. But at the end, he said, "In spite of all this, this investigator would prefer a terrestrial explanation for the incident." It was plain that this report had not been planned originally for release to the public. No Project investigator would have been so frank. With each new report, I was more and more convinced that these had been confidential discussions of various possible answers, circulated between Project "Saucer" officials. Why they had been released now was still a puzzle, though I began to see a glimmer of the answer. The Chiles-Whitted sighting was listed as Case 144. As I started on the report, I wondered if Major Boggs's "bolide" answer would have any more foundation than these other "astronomical" cases. The report began with these words: "There is no astronomical explanation, if we accept the report at face value. But the sheer improbability of the facts as stated, particularly in the absence of any known aircraft in the vicinity, makes it necessary to see whether any other explanation, even though farfetched, can be considered." After this candid admission of his intentions, the Project consultant earnestly attempts to fit the two pilots' space ship description to a slow-moving meteor. "It will have to be left to the psychologists," he goes on, "to tell us whether the immediate trail of a bright meteor could produce the subjective impression of a ship with lighted windows. Considering only the Chiles-Whitted sighting, the hypothesis seems very improbable." As I mentioned in an earlier chapter, observers at Robbins Air Force Base, Macon, Georgia, saw the same mysterious object streak overhead, trailing varicolored {p. 160} flames. This was about one hour before Chiles and Whitted saw the onrushing space ship. To bolster up the meteor theory, the Project consultant suggests a one-hour error in time. The explanation: The airliner would be on daylight-saving time. "If there is no time difference," he proceeds, "the. object must have been an extraordinary meteor. . . . in which case it would have covered the distance from Macon to Montgomery in a minute or two." Having checked the time angle before, I knew this was incorrect. Both reports were given in eastern standard time. And in a later part of the Project report, the consultant admits this fact. But he has an alternate answer: "If the difference in time is real, the object was some form of known aircraft, regardless of its bizarre nature." The "bizarre nature" is not specified. Nor does the Project "Saucer" report try to fit the Robbins Field description to any earth-made aircraft. The air-base observers were struck by the object's huge size, its projectile-like shape, and the weird flames trailing behind. Except for the double-deck windows, the air-base men's description tallied with the pilots'. With the ship at five thousand feet or higher, its windows would not have been visible from the ground. All the observers agreed on the object's very high speed. Neither of the Project "Saucer" alternate answers will fit the facts. 1. The one-hour interval has been proved correct. Therefore, as the Project consultant admits, it could not be a meteor. 2. The Robbins Field witnesses have flatly denied it was a conventional plane. The Air Force screened 225 airplane schedules, and proved there was no such plane in the area. No ordinary aircraft would have caused the brilliant streak that startled the DC-3 passenger and both of the pilots. Major Boggs's bolide answer had gone the way of his Venus explanation. I wondered if the Gorman light-balloon solution would fade out the same way. But the Project report on Gorman (Case 172) merely {p. 161} hinted at the balloon answer. In the Appendix, there was a brief comment: "Note that standard 30 inch and 65 inch weather balloons have vertical speeds of 600 and 1100 feet per minute, respectively." In all the reports I have mentioned, and on through both the case books, one thing was immediately obvious. All the testimony, all the actual evidence was missing. These were only the declared conclusions of Project "Saucer." Whether they matched the actual conclusions in Wright Field secret files there was no way of knowing. But even in these sketch reports, I found some odd hints, clues to what Project officials might really be thinking. After an analysis of two Indianapolis cases, one investigator reports: "Barring hallucination, these two incidents and 17, 75 and 84 seem the most tangible from the standpoint of description, of all those reported, and the most difficult to explain away as sheer nonsense." Case 17, I found, was that of Kenneth Arnold. But in spite of the above admission that this case cannot be explained away, it is officially listed as answered. Case 75 struck a familiar note. This was the strange occurrence at Twin Falls, Idaho, on which True had had a tip months before. A disk moving through a canyon at tremendous speed had whipped the treetops as if by a violent hurricane. The report was brief, but one sentence stood out with a startling effect: "Twin Falls, Idaho, August 13, 1847," the report began. "There is clearly nothing astronomical in this incident. . . . Two points stand out, the sky-blue color, and the fact that the trees 'spun around on top as if they were in a vacuum.'" Then came the sentence that made me sit up in my chair. "Apparently it must be classed with the other bona fide disk sightings." The other bona fide sightings! Was this a slip? Or had the Air Force deliberately left this report in the file? If they had, what was back of it {p. 162} --what was back of releasing all of these telltale case summaries? I skimmed through the rest as quickly as possible looking for other clues. Here are a few of the things that. caught my eye: Case 10. United Airlines report . . . despite conjectures, no logical explanation seems possible. . . . Case 122. Holloman Air Force Base, April 6, 1948. [This was the Commander McLaughlin White Sands report.] No logical explanation. . . . Case 124. North Atlantic, April 18, 1948 . . . radar sighting . . . no astronomical explanation. . . . Case 127. Yugoslav-Greek frontier, May 7, 1948 . . . information too limited. . . . Case 168. Arnheim, The Hague, July 20, 1948 . . . object seen four times . . . had two decks and no wings . . . very high speed comparable to a V-2. . . . Case 183. Japan, October 15, 1948. Radar experts should determine acceleration rates. . . . Case 188. Goose Bay, Labrador, October 29, 1948. Not astronomical . . . picked up by radar . . . radar experts should evaluate the sightings . . . . Case 189. Goose Bay, Labrador, October 31, 1948 . . . not astronomical . . . observed on radarscope. . . . Case 196. Radarscope observation . . . object traveling directly into the wind. . . . Case 198. Radar blimp moving at high speed and continuously changing direction. . . . Case 222. Furstenfeldbruck, Germany, November 23, 1948 . . . object plotted by radar DF at 27,000 feet . . . short time later circling at 40,000 feet . . . speed estimated 200-500 m.p.h. . . . Case 223 . . . seventeen individuals saw and reported object . . . green flare . . . all commercial and government airfield questioned . . . no success. . . . Case 224. Las Vegas, New Mexico, December 8, 1948 . . . description exactly as in 223 . . . flare {p. 163} reported traveling very high speed . . . very accurate observation made by two F.B.I. agents. . . . Case 231 . . . another glowing green flare just as described above. . . . Case 233 . . . definitely no balloon . . . made turns . . . accelerated from 200 to 500 miles per hour . . . . Going back over this group of cases, I made an incredible discovery: All but three of these unsolved cases were officially listed as answered. The three were the United Airlines case, the White Sands sightings, and the double-decked space-ship report from The Hague. Going back to the first report, I checked all the summaries. Nine times out of ten, the explanations were pure conjecture. Sometimes no answer was even attempted. Although 375 cases were mentioned, the summaries ended with Case 244. Several cases were omitted. I found clues to some of these in the secret Air Weather Service report, including the mysterious "green light" sightings at Las Vegas and Albuquerque. Of the remaining 228 cases, Project "Saucer" lists all but 34 as explained. These unsolved cases are brought up again for a final attempt at explaining them away. In the appendix, the Air Materiel Command carefully states: "It is not the intent to discredit the character of observers, but each case has undesirable elements and these can't be disregarded." After this perfunctory gesture, the A.M.C. proceeds to discredit completely the testimony of highly trained Air Force test pilots and officers at Muroc. (The 300-400 m.p.h. research balloon explanation.) The A.M.C. then brushes off the report of Captain Emil Smith and the crew of a United Airline plane. On July 4, 1947, nine huge flying disks were counted by Captain Smith and his crew. The strange objects were in sight for about twelve minutes; the crew watched them for the entire period and described them in detail later. Despite Project "Saucer's" admission that it had no {p. 164} answer, the A.M.C. contrived one. Ignoring the evidence of veteran airline pilots, it said: "Since the sighting occurred at sunset, when illusory effect are most likely, the objects could have been ordinary aircraft, balloons, birds, or pure illusion." In only three cases did the A.M.C. admit it had no answer. Even here, it was implied that the witnesses were either confused or incompetent. In its press release of December 27, 1949, the Air Force had mentioned 375 cases. It implied that all of these were answered. The truth was just the reverse, as was proved by these case books. Almost two hundred cases still were shown to be unsolved-although the real answers might be hidden in Wright Field files. These two black books puzzled me. Why had the Air Force lifted its secrecy on these case summaries? Why had Major Boggs given me those answers, when these books would flatly refute them? I thought I new the reason now but there was only one way to make sure. The actual Wright Field files should tell the answer. When I phoned General Sory Smith, his voice sounded a little peculiar. "I called Wright Field," he said. "But they said you wouldn't find anything of value out there." "You mean they refused to let me see their files?" "No, I didn't say that. But they're short of personnel. They don't want to take people off other jobs to look up the records." "I won't need any help," I said. "Major Boggs said each case had a separate book. If they'd just show me the shelves, I could do the job in two days." There was a long silence. "I'll ask them again," the General said finally. "Call me sometime next week." I said I would, and hung up. The message from Wright Field hadn't surprised me. But Smith's changed manner did. He had sounded oddly disturbed. While I was waiting for Wright Field's answer, Ken Purdy phoned. He told me that staff men from Time and Life magazines were seriously checking on the "little men" story. Both Purdy and I were sure this was a {p. 165} colossal hoax, but there was just a faint chance that someone had been on the fringe of a real happening and had made up the rest of the story. They key man in the story seemed to be one George Koehler, of Denver, Colorado. The morning after Purdy called, I took a plane to Denver. During the flight I went over the "little men" story again. It had been printed in over a hundred papers. According to the usual version, George Koehler had accidentally learned of two crashed saucers at a radar station on our southwest border. The ships were made of some strange metal. The cabin was stationary, placed within a large rotating ring. Here is the story as it was told in the Kansas City Star: In flight, the ring revolved at a high rate of speed, while the cabin remained stationary like the center of a gyroscope. Each of the two ships seen by Koehler were occupied by a crew of two. In the badly damaged ship, these bodies were charred so badly that little could be learned from them. The occupants of the other ship, while dead when they were found, were not burned or disfigured, and, when Koehler saw them, were in a perfect state of preservation. Medical reports, according to Koehler, showed that these men were almost identical with earth-dwelling humans, except for a few minor differences. They were of a uniform height of three feet, were uniformly blond, beardless, and their teeth were completely free of fillings or cavities. They did not wear undergarments, but had their bodies taped. The ships seemed to be magnetically controlled and powered. In addition to a piece of metal, Koehler had a clock or automatic calendar taken from one of the crafts. Koehler said that the best assumption as to the source of the ships was the planet Venus. When I arrived at Denver, I went to the radio station {p. 166} where Koehler worked. I told him that if he had proof that we could print, we would buy the story. As the first substantial proof, I asked to see the piece of strange metal he was supposed to have. Koehler said it had been sent to another city to be analyzed. I asked to see pictures of the crashed saucers. These, too, proved to be somewhere else. So did the queer "space clock" that Koehler was said to have. By this time I was sure it was all a gag. I had the feeling that Koehler, back of his manner of seeming indignation at my demands, was hugely enjoying himself. I cut the interview short and called Ken Purdy in New York. "Well, thank God that's laid to rest," he said when I told him. But even though the "little men" story had turned out-as expected--a dud, Koehler had done me a good turn. An old friend, William E. Barrett, well-known fiction writer, now lived in Denver. Thanks to Koehler's gag, I had a pleasant visit with Bill and his family. On the trip back, I bought a paper at the Chicago airport. On an inside page I ran across Koehler's name. According to the A.P., he had just admitted the whole thing was a big joke. But in spite of this, the "little men" story goes on and on. Apparently not even Koehler can stop it now. {p. 167} CHAPTER XIX FOR TWO WEEKS after my return to Washington, General Sory Smith held off a final answer about my trip to Wright Field. Meantime, Ken Purdy had called him backing my request to see the Project files. It was obvious to me that Wright Field was determined not to open the files. But the General was trying to avoid making it official. "Why can't you accept my word there's nothing to the saucers?" he asked me one day. "You're impeaching my personal veracity." But finally he saw there was no other way out. He told me I had been officially refused permission to see the Wright Field files. Some time later, Ken Purdy phoned General Smith. "General, if the Air Force wants to talk to us off the record, we'll play ball. True will either handle it from then on whatever way you think best or we'll keep still." Whether this offer was relayed higher up, I don't know. But nothing came of it. Meantime, saucer reports had begun to come in from all over the country. Some even came from abroad. Some of these 1950 sightings have already been mentioned in early chapters. Besides the strange affair at Tucson on February 1, there were several other cases in February. Three of these were in South America. One saucer was reported near the naval air station at Alameda, California. Some were sighted in Texas, New Mexico, and other parts of the Southwest. In March, the wave of sightings reached such a height that the Air Force again denied the saucers' existence. This followed a report that a flying disk had crashed near Mexico City and that the wreckage had been viewed by U. S. Air Force officials. Scores of Orangeburg, South Carolina, residents watched a disk that hovered over that city on March 10. It was described as silver-bright, turning slowly in the air before it disappeared. The day before this, residents {p. 168} of Van Nuys, California, saw a bright disk moving swiftly four hundred feet in the air. Seen through a telescope, it appeared to be fifty feet in diameter. Disks were reported at numerous places in Mexico, including Guadalajara, Juárez, Mazatlán, and Durango. On the twelfth of March, the crew and passengers of an American Airlines ship saw a large gleaming disk high above Monterrey airport in Mexico. Captain W. R. Hunt, the senior airline pilot, watched the disk through a theodolite at the airport. This disk and most of the others seen in Mexico were similar in description to the one sighted at Dayton, Ohio, on March 8. This was the large metallic saucer that hovered high over Vandalia Airport, until Air Force and National Guard fighters raced up after it. The disk rose vertically into the sky at incredible speed, hovered a while longer, and then vanished. Within twenty-four hours this mystery disk had been "identified" as the planet Venus. (It was broad daylight.) Newspapers quoted "trained astronomical officials in Dayton" as the source for this explanation. Meanwhile the Mexican government newspaper, El Nacional, quoted "a famous and reputable astronomer" as saying the numerous disks reported over Mexico "carry visitors from Mars." One of the strangest reports came from the naval air station at Dallas, Texas. It was about 11:30 A.M. on March 16 when CPO Charles Lewis saw a disk streak up at a B-36 bomber. The disk appeared about twenty to twenty-five feet in diameter, Lewis reported. Racing at incredible speed, it shot up under the bomber, hung there for a second, then broke away at a 45-degree angle. Following this, it shot straight up into the air and disappeared. Captain M. A. Nation, C. O. of the station, said it was "I the second report in ten days. On March 7, said Captain Nation, a tower control operator named C. E. Edmundson saw a similar disk flying so fast it was almost a blur. "He estimated its speed at three thousand to four thousand miles per hour," Captain Nation stated. "Of {p. 169} course, he had no instruments to compute the speed, so that's a pure estimate." It was some time before this when I heard the first crazy rumor about the guided-missile display. This story, which had new details every time I heard it described the Air Force as refusing to let the Navy announce a new type of missile. According to the rumors, the Air Force was trying to prove its own missile far superior, to keep the Navy from invading its long-range bombing domain. Then the Army joined the pitched battle with still a third guided missile, according to the rumors. And the flying disks? Army, Navy, and Air Force missiles, launched in droves all over the country to prove whose was the best? A public missile race, with the joint Chiefs of Staff to decide the winner! It seems fantastic that this theory would be believed by any intelligent person. In effect, it accuses the armed services of deliberate, criminal negligence, of endangering millions in the cities below. I am convinced that some of these rumors led to at least one of the published guesses about our missile program. One widely publicized story stated that the flying saucers seen hurtling through our skies are actually two types of secret weapons. One, according to radio and newspaper accounts, is a disk that whizzes through space, halts suspended in the air, soars to thirty thousand feet, drops to one thousand feet, and then usually disintegrates in the air. These saucers, it was said, ranged from 20 inches to 250 feet in diameter. They were supposed to be pilotless--and harmless. The second type was said to be a jet version of the Navy's circular airfoil "Flying Flapjack." It was credited with fantastic speed. The "true disks," however, were mainly Air Force devices, according to the report. "Some are guided, others are not," said the radio commentator who released this story. "They can stay stationary, dash off to right or left, and move like lightning. But they are utterly harmless." In these "harmless" disks there was supposed to be an {p. 170} explosive charge that destroyed them in mid-air at a predetermined time. Within a few days after this story was broadcast, the United States News and World Report declared that the saucers are real, and identified them as jet models of Navy "Flying Flapjacks." This magazine, which is not an official publication despite its name, mentioned the variable-direction jet principle that I had previously described in the True article. These two flying-saucer "explanations" brought denials from the White House, the Navy, and the Air Force. The Air Force flatly declared that: 1. None of the armed forces is conducting secret experiments with disk-shaped flying objects that could be a basis for the reported phenomena. 2. There is no evidence that the latter stem from the activities of any foreign nation. Before this, President Truman stated he knew nothing of any such objects being developed by the United States or any other nation. The Navy denial came immediately after the first broadcast story. It ran: "The Navy is not engaged in research or in flying any jet-powered, circular-shaped aircraft." The Navy added that one model of a pancake-shaped aircraft, called the Zimmerman Skimmer, was built but was never flown. However, a small, three-thousand-pound scale model did fly and was under radio control during flight. This last device is now being rumored as the Navy's unpiloted "missile," said to have been launched over the country like the so-called "harmless" disks. Even though all these accounts have been officially denied, many Americans may still believe they are true. I have no desire to criticize the authors of these stories; I believe that in following up certain guided-missile leads they were misled into accepting the conclusions they gave. But these stories, particularly the accounts of huge unpiloted disks, may have planted certain fears in the public mind-fears that are completely unwarranted. For {p. 171} this reason, I have personally checked at Washington in regard to the dangers of unpiloted missiles. Here aye the facts I learned: 1. Neither the Army, Navy, nor Air Force has at any time staged any guided-missile competition as rumored. 2. No unpiloted missiles or remote-controlled experimental craft have been tested over American cities or heavily populated areas. 3. No unpiloted missile carrying dangerous explosives, whether for destruction of the device or other purposes, has been deliberately launched or tested over heavily populated areas. In regard to the so-called jet-propelled "Flying Flapjack," I have been assured by Admiral Calvin Bolster, of the Navy Bureau of Aeronautics, that this type of plane has never been produced. I concede that he might make this statement to conceal a secret development, but there is one fact of which every American can be certain: Neither this type, nor the radio-controlled smaller model, has been or will be flown or launched over areas where people would be endangered. The three armed services are working on guided missiles. They are not risking American lives by launching such missiles at random across the United States, Although most of our guided-missile projects are secret, it is possible to give certain facts about guided-missile developments in general. The first successful long-range missiles were produced by the Germans. These were the buzz-bomb and. the V-2 rocket. But research in various other types was carried on during the war. Some of this was with oval and round types of airfoils. As already stated by Paul Redell, there is strong evidence that the disk-shaped foil resulted from German observations of either space ships or remote-control disk-shaped "observer units." All the Nazi space-exploration plans followed this discovery that we were being observed by a race from another planet. After the end of World War II, the international guided-missile race began, with the British, Russians, and ourselves as the chief contenders. Numerous types have been developed-winged bombs, small radar-guided {p. 172} projectiles launched from planes, and ground-to-plane plane-to-ground, and plane-to-plane missiles, equipped with target homing devices. In certain recent types, the range can be stated as several hundred miles. So far as I have learned, after weeks of rechecking this point, not a single long-range missile has been identified as Russian. Since this country is working closely with Great Britain on global defense problems, it is no violation of security to say that we have probably exchanged certain guided-missile information. In regard to the British long-range missile picture outlined to me by John Steele, I can state two major facts: 1. The British have categorically denied testing such long-range missiles over American territory, where they might endanger American citizens. There is convincing evidence that they are telling the truth. 2. There is no British missile now built, or planned, that could explain the objects seen by Captain Mantell, Chiles and Whitted, and witnesses in most of the major sightings. The preceding statement applies equally to American-built missiles. There is no experimental craft or guided missile even remotely considered in this country that would begin to approach the dimensions and performance of the space ships seen in these cases. There is concrete evidence that the United States is as well advanced as any other nation in guided-missile development. Certain recent advances should place us in the lead, unless confidential reports on Soviet progress are completely wrong. If American scientists and engineers can learn the source of the space ships' power and adapt it to our use, it may well be the means for ending the threat of war. The Soviet scientists are well aware of this; their research into cosmic rays and other natural forces has been redoubled since the flying-saucer reports of 1947. The secret of the space ships' power is more important than even the hydrogen bomb. It may someday be the key to the fate of the world. CHAPTER XX AFTER one year's investigation of the flying saucers and Air Force operations, I have come to the following conclusions: 1. The Air Force was puzzled, and badly worried when the disks first were sighted in 1947. 2. The Air Force began to suspect the truth soon after Mantell's death--perhaps even before. 3. Project "Saucer" was set up to investigate and at the same time conceal from the public the truth about the saucers. 4. During the spring of 1949 this policy, which had been strictly maintained by Forrestal, underwent an abrupt change. On top-level orders, it was decided to let the facts gradually leak out, in order to prepare the American people. 5. This was the reason for the April 27, 1949, report, with its suggestions about space visitors. 6. While I was preparing the article for the January 1950 issue of True, it had been considered in line with the general education program. But the unexpected public reaction was mistaken by the Air Force for hysteria, resulting in their hasty denial that the saucers existed. 7. Because the Air Force feared any closer analysis of the Mantell case, Major Boggs was instructed to publicize the Venus explanation. Although it had been denied, the Air Force knew that most people had forgotten this or had never known it. 8. Major Boggs, having stated this answer publicly (along with the other Chiles-Whitted and Gorman answers), was forced to stick to it, though he knew it was wrong and that the case summaries would prove it. 9. The case summaries were released to a small number of Washington newsmen, to continue planting the space-travel thought; this decision being made after True's reception proved to the Air Force that the public was better prepared than had been thought. In regard to the flying saucers themselves, I believe {p. 174} that in the majority of cases, space ships are the answer: 1. The earth has been under periodic observation from another planet, or other planets, for at least two centuries. 2. This observation suddenly increased in 1947, following, the series of A-bomb explosions begun in 1945. 3. The observation, now intermittent, is part of a long-range survey and will continue indefinitely. No immediate attempt to contact the earth seems evident. There may be some unknown block to making contact, but it is more probable that the spacemen's plans are not complete. I believe that the Air Force is still investigating the saucer sightings, either through the Air Materiel Command or some other headquarters. It is possible that some Air Force officials still fear a panic when the truth is officially revealed. In that case, we may continue for a long time to see routine denials alternating with new suggestions of interplanetary travel. The education problem is complicated by two imperative needs. We must try to learn as much as we can about the space ships' source of power, and at the same time try to prevent clues to this information from reaching an enemy on earth, If censorship is suddenly imposed on all flying-saucer reports, this will be the chief reason. This would also help solve a minor problem where partial censorship now exists. A few test missiles launched from a southwest base have been seen by citizens at a distance from the proving grounds. In some cases, their reports have got into local papers, though the wire services did not carry them. These missile tests are peculiarly different from the general run of flying-saucer reports. Contrasted with the Chiles-Whitted, Mantell, and other space-ship sightings, they stand out with a certain pattern, easy to recognize. News or radio reports of these tests might accidentally give an enemy clues to the type, speed, and range of this particular missile, once he learned the pattern. Periodic censorship, or even a complete blackout of sighting reports, may be enforced during the next year or so. For the purposes mentioned, such action would be {p. 175} justified. But whenever such censorship is lifted, the complete truth about space visitors should be told at the same time: the full details of all the major cases, the size of the Godman Field space ship, any attempted landings or other efforts at contact by interplanetary visitors, and all other details that now are official secrets. I also believe that a certain group of disk sightings in this country is linked with our guided missiles. Official announcements, of course, may be delayed a long time. With this exception, I believe that Americans should be told the truth, now. When the announcement of our guided missiles is made, some Americans not familiar with the facts may accept it as a full answer. If officials are not yet ready to reveal the space-travel facts, the Mantell evidence and other key cases may be deliberately glossed over. But even if all the evidence--the world-wide sightings, the old records, the Chiles-Whitted and other cases--should be completely ignored, Americans cannot escape eventual contact with dwellers on other planets. Even though space visitors never attempt contact with us, sooner or later earthlings will be traveling to distant planets--planets that scientists have said are almost surely inhabited. The American people have proved their ability to take incredible things. We have survived the stunning impact of the Atomic Age. We should be able to take the Interplanetary Age, when it comes, without hysteria. 
34815	----	[Transcriber's Notes: An underscore (_) is used to denote _italic_ text. A tilde (~) is used to denote ~bold~ text. A equals (=) is used to denote =underlined= text. Several illustrations are either blank or have only text in them. Those were rendered as fully as possible in plain text. Other illustrations are noted with an [Illustration] tag and the caption, if there is one. The advertisements which were originally at the front of the book have been moved to the back. ] JANE'S ALL THE WORLD'S AIRCRAFT 1913 A Reprint of the 1913 Edition of All The World's Air-craft Edited by FRED T. JANE ARCO PUBLISHING COMPANY, INC. New York First published by Sampson Low Marston in 1913 This edition published 1969 by ARCO PUBLISHING COMPANY, INC. 219 Park Avenue South, New York, N. Y. 10003 Library of Congress Catalog Number 69-14964 ARCO Book Number 668-01880-1 Printed in Great Britain _Published Annually._ All the World's AIR=CRAFT. (ORIGINALLY KNOWN AS "ALL THE WORLD'S AIRSHIPS.") (WAR FLYING ANNUAL.) FOUNDED AND EDITED BY FRED T. JANE, Founder and Editor of "FIGHTING SHIPS" (Naval Annual), Etc. PART A.--AEROPLANES AND DIRIGIBLES OF THE WORLD. PART B.--HISTORICAL AEROPLANES OF THE LAST SIX YEARS. PART C.--THE WORLD'S AERIAL ENGINES. PART D.--AERIAL "WHO'S WHO" AND DIRECTORY. FIFTH YEAR OF ISSUE. (Founded 1909.) LONDON: SAMPSON LOW, MARSTON & CO., Ltd. 1913. Printed by Netherwood, Dalton & Co., Phoenix Works, Rashcliffe, Huddersfield. CONTENTS PAGE Preface 7 Glossary of Technical Terms 9 ~PART A.~ Argentine (~J. Schiere~) 15 Austrian (~Special Austrian Editor~) 16 Aeroplanes 17 Dirigibles 22 Belgian (~J. Bracke~) 26 Aeroplanes 27 Dirigibles 29 Brazilian 31 British 32 Aeroplanes 37 Dirigibles 60 British Colonies, Etc. 63 Bulgarian 66 Central American Republics 67 Chilian 68 Chinese 69 Danish 70 Dutch (~J. Schiere~) 71 French (~Special French Editor~) Aeroplanes 73 Dirigibles 109 German (~Special German Editor~) 126 Aeroplanes 131 Dirigibles 151 Greek 168 Italian (~Special Italian Editor~) 169 Aeroplanes 172 Dirigibles 176 Japanese (~Partly Official~) 180 Aeroplanes 181 Dirigibles 182 Mexican 183 Norwegian 184 Peruvian 185 Portuguese (~J. Schiere~) 186 Roumanian 187 Russian 188 Aeroplanes 190 Dirigibles 191 Servian 193 Spanish 195 Swedish (~Lieut. Dahlbeck~) 196 Swiss (~Special Swiss Editor~) 198 Turkish 200 Uruguay 200 United States (~W.L. Jones~) 201 Aeroplanes 202 Dirigibles 220 ~PART B.~ Historical Aeroplanes of the Last Six Years 1B et seq. ~PART C.~ Principal Aeroplane Engines 1C Austrian (~W. Isendahl~) 2C Belgian 2C British 3C French 4C German (~W. Isendahl~) 8C Italian 11C Swiss 12C U.S.A. 13C ~PART D.~ Aerial "Who's Who" 1D Classified Aerial Directory 12D Alphabetical Index--Aeroplanes end of " " Dirigibles book PREFACE. As conjectured last year, considerable further changes have been produced in this edition. When, some five years ago, work on this annual was first commenced, the military aviator was an idle dream. Fighting men in dirigibles were a bare possibility; but nothing more than that. Every amateur building an aeroplane (or even merely intending to build one) in his back garden was a possible "conqueror of the air." The aeroplane was going to oust the motor car as a sporting vehicle--everyone was quite certain about that! Beyond that, nothing! To-day everything is completely changed and except as a war machine the aeroplane is of little interest or use to anyone. A few civilian aviators are still flying, but in practically every case they are doing so in connection with the business aspect of the question. There is no "sport of aviation" such as the prophets foretold a few years ago. An increasing number of people obtain their pilot certificates and lists of these are still given, although the title of "aviator" is in the bulk of cases somewhat of a courtesy one, since so few keep on flying once they have secured their brevets. It is as a _war machine_ that the aeroplane has come into its own. The Italian aeroplanes over and over again proved their utility in Tripoli. Although in the Balkan War aircraft were less in evidence than many expected, this may be attributed to the peculiar circumstances of the campaign and also to the scarcity of available machines. Every country is now engaged in forming its aerial fleets. How far the naval and military branches will coalesce, or how far they will differentiate remains to be seen. The probabilities, at present, all point in the latter direction, and that just as an army is made up of cavalry, infantry, artillery, etc., and a navy of battleships, cruisers, torpedo craft and submarines, so the sky fleets seem destined to consist of groups of different types of machines, each type designed for some special purpose. The increased war utility of aircraft has necessitated an extension of the pages devoted to organisation of military aviation, etc. The details given are by no means as full as I could wish; but all organisations are being so continually changed owing to increased experience that satisfactory data are not very easy to come by. During the past twelve months or so we have learned at least one or two important things. The mere fact of the possession of aeroplanes by a nation is a military factor of comparatively little importance. A nation possessing next to no aeroplanes can easily acquire a few hundreds in case of emergency _if she has the people to build them_. The real problem is two-fold. First, of course, is the possession of trained and efficient aviators to fly the machines. Naval and military officers who have merely secured their brevets at a flying school are of no immediate value; civilians of the same kind are of still less utility. Second to this is the productive capacity of any country; which may roughly be gauged from the number and importance of its firms engaged in construction. These points cannot too strongly be enforced. The air strength of any nation in case of war resides in its efficient flying men and in its own productive capacity. The next war will see aircraft quite as much "contraband" as warships, and the nation which relies upon aerial imports will be foredoomed at once. One month is probably the utmost effective life of an aeroplane on hard active service and it may well be a good deal less. And firms capable of building efficient machines cannot be improvised. A remarkable feature of the last twelve months has been the recrudescence of the dirigible, which is now in far greater esteem than it was a year ago, or for that matter, ever before. In the past there is no doubt that progress was hampered by arguments between the advocates of "heavier than air" and "lighter than air," and a curious notion that the one could only exist at the expense of the other. Such ideas are now dead, and it is recognised that for war purposes both have their uses and that both are interdependent. It is not quite yet realised how intense this interdependence is likely to be. Briefly the present situation may be summed up as follows: the dirigible has enormous potentialities for attack on fortified bases and the like, but its powers of defence, guns or no guns, are very slight. A single aeroplane should be able to disable or destroy without very great difficulty the finest dirigible yet built (supposing it able to find the airship in the vastness of the air). The damage that a single aeroplane can do to land defences or ships is, however, entirely trivial--at any rate at present. Hence the aerial war unit already formed in Germany, and likely to be in existence everywhere else ere another year or so has passed. This unit is a dirigible of great offensive powers, associated with a number of aeroplanes presumably intended to defend it and ward off and defeat attack by hostile aeroplanes. This is merely the crude beginning, it seems reasonably safe to prophecy that in the early future the aerial war-unit will be made up somewhat as follows:-- (_a_) An offensive dirigible, carrying the maximum of bombs, etc. (_b_) One or two dirigibles carrying oil and petrol for the aeroplanes--possibly capable of dealing with all minor repairs and of carrying a certain number of aeroplanes on board. (_c_) A number of war aeroplanes specially designed for fighting other aeroplanes and attacking hostile dirigibles as chances may occur. (_d_) A few very swift one man aeroplanes which will be the eyes of the unit. This seems an early certainty. After all it merely reproduces for the air what centuries of experience have shewn to be essential for fleets and armies. The matter is a fascinating subject for speculation; but in connection with a work that exists merely to deal with things as they are at present, is perhaps, better not now pursued further. One point, however, may perhaps be mentioned, and that is that victory or defeat in aerial warfare seems likely to depend upon which side can first destroy the other's bases. A base-less dirigible will not live long. This is likely to lead to very great attention being paid at an early date to anti-aircraft guns and other devices for the defence of aerial bases. Reverting to the arrangement of the present edition, a few words may be said about some of the changes. As stated last year the clumsy old system of grouping monoplanes, biplanes, etc., separately has been abolished. So many firms specialise in both that any such grouping could only lead to confusion. A tabular system has been generally adopted for most new matter. This will be found far more convenient for reference, and of course, saves a great deal of space. The effective age of aeroplanes is somewhat of a vexed question, for while one year probably represents the really effective war utility endurance, even in peace time, school life is more or less indefinite and so is ordinary private life. Consequently--although "dead machines" are excluded it has not been possible to draw an exactly uniform age limit line beyond that. Speaking generally modern machines represent as a rule detail improvements rather than the complete changes of the past. For example, the gap between 1911 and 1913, is far less than the gap between 1909 and 1911. This fact is beginning to make itself felt in war machines. In Part B an attempt has been made to collect illustrations of aeroplanes of the past which for one reason or another possess an historical interest. This section is remarkable for two totally different things (1) the early anticipations of some modern practice, and (2) the past prevalence of certain other ideas which are now totally extinct. Part C deals with aero-engines. It is mainly remarkable--in comparison with past issues--for the large number of engines which have ceased to exist. It is probably still too ample; as a year hence quite half the makers still recorded are likely to disappear. The mere ability to construct motor car engines is no longer of value. The aeroplane engine designer needs to be a specialist. The absolutely ideal aero-engine no doubt yet remains to be produced; but meanwhile the tendency of users to concentrate upon fewer makes is increasingly evident, despite the fact that the best engine for one particular type of machine is not necessarily the best for some other type. In conclusion I tender my most grateful thanks to all those who have so kindly collaborated with or for me in the various sections. The book is still some way from being near my ideal, but I have every hope that this edition will be generally considered a very considerable improvement upon previous issues. FRED T. JANE. _Bedhampton,_ _Hants.,_ _England._ GLOSSARY OF TECHNICAL TERMS, Etc. ENGLISH. | DUTCH. | FRENCH. | GERMAN. | ITALIAN. ----------------------------------------------------------------------------------------- Abaft | Achterste deel | Arrière | Hinter | A poppa Accessories | Onderdeelen | Accessoires | Zubehör | Accessori Accumulator | Accumulator | Accumulateur | Akkumulator | Accumulatore ~AEROPLANE~ | Dekvlieger | Aéroplane | Drachenflieger | Aereoplano Aeronaut | Luchtvaarder | Aéronaute | Luftschiffer | Aereonauta | | Aviateur | | Aerostat | Luchtbal | Aérostat | Freiballon | Aereostato Aft | Achterdeel | Arrière | Hinten | Addietro After (rear) | Achter | Arrière | Hinterer | Poppa Air-cooled | Luchtgekoeld | Refroidit par | Luftgekuhlt | Raffredda ad | | Pair | | aria Angleiron | Hoekÿzer | Cornière | Eck Schiene | Ferro ad angolo Anti-friction | Wit metaal | Métal | Lagermetall | Metallo beanco metal | | anti friction | | (anti frizione) | | on regule | | Aviation | Vliegtechniek | Aviation | Flugtechnik | Aviazione Babbit Metal | Babbits metaal | Métal Babbitt | Lagermetall | Metallo Babbitt | | on regule | | Balance | Evenwicht | Equilibre | Gleichgewicht | Equilibrio Ball bearings | Kogellagers | Coussinets à | Kugel Lager | Cuscinetti a | | billes | | sfere Ballonet | Luchtzak | Ballonet | Ballonet | Palloncino | | | | compensatore Battery | Batterÿ | Batterie | Batterie | Pila a secco Bearing metal | Kussenmetaal | Métal pour les | Lager metall | Metallo par | | coussinets on | | cuscinette | | regule | | Behind | Achter | Derrière | Hinter | Di dietro Bevel geared | Kegelraderwerk | Engrenage | Konischer | Ingranaggio | | Conique | Antrieb | conico Biplane | Tweedekker | Biplan | Zwei decker | Biplano Blades | Bladen | Pales | Flügel | Pale (of propeller)| (der schroef) | | | delt'elica Body | Romp | Fuselage | Körper | Telaio o | | | | chassis Bolt | Bout | Bonlon | Bolzen | Bollone Box-kite | Kabel-vlieger | Cerf-volant | Drachen | Aquilone a celle Bracket | Klamp | Tasseau | Stütze | Sostegno Brake | Rem | Frein | Bremse | Freno Breadth | Breedte | Largeur | Breite | Larghezza Canvas | Doek | Toile | Leinwand | Tela Car | Gondel | Nacelle | Gondel | Navicella Carburetter | Vergasser | Carburateur | Vergaser | Carburatore Casting | Gietstuk | Moulage | Guss Stück | Getto Centre of | Zwaartepunt | Centre de | Schwerpunkt | Centro di Gravity | | Gravité | | gravità Chain driven | Door ketting | Transmission | Ketten antrieb | Trasmissione a | gedreven | par chaine | | catena Chassis | Gestel | Chassis | Motor Rahmen | Chassis Circumference | Omtrek | Circonférance | Umfang | Cuconferenza Clutch | Haak | Embrayage | Kupplung | Innesto Connection | Schakeling | Couplage | Kupplung | Connessione Control | Stuurinrichting | Direction | Lenk | Meccanismo di | | | Ubersetsung | direzione Coupled | Gekoppeld | Jumelé | Paarweise | Accoppiato Crank shaft | Krukas | Arbre à | Kurbelwelle | Albero delle | | manivelle | | manovelle Cylinder | Cÿlinder | Cylindre | Zylinder | Cilindro Die cast | Ondermetaallager | Coussinets | Schalenguss | Cuscinette fusi Bearings | | moutés | Lager | in conchiglia | | encogiulles | | ~DIRIGIBLE~ | Motorballon | Dirigeable: | Motorluftschiff | Dirigibile | | Aéronat | | Diameter | Middellÿn | Diamètre | Durchmesser | Diametro Direct driven | Direct | Prise directe | Direkter | Presa diretta | gekoppeld | | Antrieb | Electric | Electrische | Soudure | Elektrisches | Soldatura welding | Lassching | électrique | Schweissen | elettrica Elevator | Hoogtestuur | Gouvernail de | Hohensteuer | Timone (horizontal | | profondeur | | orizzontale rudder) | | | | Engine | Motor | Moteur | Motor | Motore Fan | Ventilator | Ventilateur | Ventilator | Ventilatore Fittings | Fittings | Garniture | Garnitur | Armamento Flight | Vlucht | Vol | Flug | Volo Flown | Gevlogen | Volé | Geflogen | Volato Fore | Voor | Avant | Vorderer | Ouvanti Forward | Van Voren | En avant | Vor | Davanti (in front) | | | | Frame | Romp | Fuselage | Rahm | Telais Framework | Geraamte | Fuselage | Gerüste | Intelaiatura Gas bag | Gaszak | Enveloppe | Luftballon (Hülle) | Involucro Geared to | Vertand | Multiplié à | Uebersetst auf | Moltiplicato a Gear driven | Met tandrad- | | durch Zahnrädern | Trasmissione | overbrenging | | getrieben | a ingranaggi Girder | Balk | Poutre | Balken | Longarin Glider | Glÿdvlieger | Planeur | Gleitflieger | Apparecehio a | | | | planare Gondola | Gondel | Nacelle | Gondel | Navicella Helices | Schroeven | Helices | Schranben | Eliché Helicopter | Schroefvlieger | Helicoptère | Schraubenflieger | Elicoplano | | | | Elicottero Horizontal | Horizontaalvlak | Plan horizontal| Horizontal fläche | Piano plane (in a) | (in een) | | | orizzontale Horse power | Paardekracht | Puissance en | Pferdekraft | Forza cavalli | | chevaux | | Hydrogen | Waterstof | Hydrogène | Wasserstoff | Idrogens Ignition | Ontsteking | Allumage | Zündung | Accensione Inch | Duim | 25.39 m/m. | 25.39 m/m. | Pollice = | | | | 25.39 m/m. Inclination | Helling | Inclination | Schrägstellung | Inclinazione Keel | Kiel | Carène | Kiel | Chiglia K.P.M. | K.P.U. (kilom. | Kilometres par | Kilometre pro | Chilometre (kilometres | per uur) | heure | Stunde | all'ora per hour) | | | | Kite | Vlieger | Cerf volant | Drachen | Aquilone Length | Lengte | Longueur | Länge | Lunghezza Lining metal | Lagermetaal | Métal pour | Lagermetall | Metallo per | | garnir less | | bronzine dei | | coussinets ou | | cuscinetti | | régule | | Lower (planes)| Onder (vlakken) | Inferieur | Untere Flächen | Piani inferiori | | (plans) | | Magneto | Magneet | Magneto | Magnet | Magneto ~Maximum~ | Maximum | Maximum | Maximum | Massimo Middle (plane)| Midden (vlak) | (Plan)au | Mittel Deck | Piano medio | | milieu | | Mile | Mÿl | Mile | Meile | Miglio Military | Militair | Militaire | Militärische | Militare Miscellaneous | Verschillend | General | Verschiedenes | Diversi | (allerlei) | | | ~Monoplane~ | Eendekker | Monoplan | Ein decker | Monoplano ~Motor~ | Motor | Moteur | Motor | Motore M.P.H. | M.P.U. | Vitesse | M.P.S. | Miglia all'ora (miles per | (mÿl per uur) | | | hour) | | | | Multiplane | Veeldekker | Multiplan | Vieldecker | Multiplano Nacelle | Schuitje | Nacelle | Gondel | Navicella ~Non-rigid~ | Slap | Souple | Unstarr | Non-rigido-- | | | | flessibile Petrol | Benzine | Essence | Benzin | Benzina gasoline) | | | | Pilot (driver)| Bestuurder | Flyer: Aviateur| Führer | Aviatore Pivot | Tap | Pivot | Gewinde Zapfen | Perno Planes | Vlakken | Plans | Flächen | Piani Plug | Kaars, stop | Bougie | Zünd Kerze | Candela Pound (lb.) | Eng pond = | 0.453 kg. | 0.453 kg. | Libbra = | 0,453 K.G. | | | 0.453 kg. Pressure | Druk | Pression | Druck | Pressione Propeller | Schroef | Helice | Schraube | Eliche Quadruplane | Vierdekker | Quadruplan | Vier decker | Qudruplani Quintuplane | Vÿfdekker | Quintuplan | Fünf decker | Quintuplani Radiator | Koeler | Radiateur | Kühler | Radiatore Rear (in) | Achterkant | En arrière | Hinten | Indictro | (aan de) | | | Reduction | Reductie- |Engrenage de | Ubersetzung | Ingranaggi di gearing | overbrenging |demultiplication| | ridugione R.P.M. | Omw. per minuut | Tours | Umlauf | Giri al minuto (revolutions | | | | per minute) | | | | ~Rigid~ | Stÿf | Rigide | Starr | Rigido Rises | Stÿgt | S'eléve | Hebt sich | Si eleva Rubber | Gummi | Caoutchouc | Gummi | Gomma Rudder | Roer, Stuur | Gouvernail | Steuer | Timone Section | Doorsnede | Section | Durchschnitt | Regione ~Semi-rigid~ | Halfstÿf | Demi-rigide | Halb Starr | Semi-rigido Span | Spanwÿdte | Envergure | Spanweite | Apertura ~Speed~ | Snelheid | Vitesse | Geschwindigkeit | Velocita Stability | Evenwicht | Stabilité | Gleichgewicht | Stabilità Stabilising | Evenwichtsvlakken| Ailerons | Gleichgwichtsflächen| Piani fins | | | | stabilizzaton Steel | Staal | Acier | Stahl | Acciaio ~Steering | Stuurtoestel | Direction | Steuerung | Meccanismo Gear~ | | | | | | | | di direzione Steering Wheel| Stuurwiel | Volant | Steuerrad | Volante di | | | | direzione ~Supporting~ | Draagvlak | Surface | Tragfläche | Superficio ~surface~ | | | | di sostegno Surfaces | Oppervlakken | Surfaces | Flächen | Superfici Suspension | Ophanging | Suspension | Aufhängung | Sospensioni Switch | Omschakelaar | Interrupteur | Schalter | Interruttore | | | | Tail | Staart | Queu | Schwanz | Coda ~Total weight~| Totaal gewicht | Poids totale | Gesamtlast | Peso totale Transmission | Overbrengingsas | Arbre de | Transmissions Welle | Albero di Shaft | | transmission | | trasmissione Trial | Proef | Essai | Probe | Prova ~Triplane~ | Driedekker | Triplan | Drei decker | Triplano | | | | Universal | Kogelgewricht | Joint | Kardan | Guinta Joint | | | | | | universel | | universale Unladen | Onbelast, leeg | à vide | Leerlaufend | Upper (planes)| Boven (vlakken) | Superior | Ob ere | Piani Superior ~Useful lift~ | Nuttier last | Poids utile | Outlast | Forza utile di | | | | elevation Valve | Kelp | Soup ape | Lentil | Valvular Vertical plane| Vertical vlak | Plan vertical | (in der) | Neal piano (in the) | (in heat) | | Vertikalfläche | verticale Vertical | Zÿstuur | Gouvernail | Seitensteuer | Timone rudder | | | | | | verticale | | verticale ~Volume~ | Inhoud | Volume | Inhalt | Volume | | | | Water-cooled | Watergekoeld | Refroidissement| Wasserkühlung | Raffreddata | | par eau | | ad acqua ~Weight~ | Gewicht | Poids | Gewicht | Peso Wheels | Wielen | Roues | Raeder | Ruote ~Wings~ | Vleugels | Ailes | Flügel | Ali Wood | Hout | Bois | Holz | Legno | | | | Yard (measure)| Yard (maat)= | 0.914 mètres | 0.914 meter | Jarda=0.914 m. | 0,914 M | | | Part A. AEROPLANES & DIRIGIBLES. ARRANGED BY NATIONALITIES IN ALPHABETICAL ORDER. Note.--Every nation is given in the following fixed order:-- List of Aerial Societies and Clubs, with addresses and Secretaries where possible. List of Aerial Journals, with addresses, price, and dates of publication. List of Flying Grounds for aeroplanes, and hangars for dirigibles (if any). List of Military and Naval Machines and aviators. List of Private Aviators, total of machines, etc. AEROPLANES in alphabetical order, _uniform scale_ plans, and particulars. DIRIGIBLES: Military and private _uniform scale_ plans, and particulars. Note.--The uniform scale of dirigible plans is a smaller scale than that used for aeroplanes. ARGENTINE. (Revised by J. SCHIERE, Aeronautical Engineer and Librarian, Dutch R. Ae. C.) ~Aerial Societies~:-- Ae.C., Argentino, 561, S. Martin, Buenos Ayres. ~Aerial Journals~:-- Boletin del Ae.C., Argentino (Monthly). ~Flying Grounds~:-- ~Aerodromo Villa Lugano~. (P. Castabert, Director.) ~Aerodromo del Palomar~. (Military). ~Military Aviation.~ At the end of 1912 there were 6 military aeroplanes (3 _Bleriot_, 1 _Castaibert_, 1 _Nieuport_, and 1 _H Farman_)--all 1912 models. Marcel Paillette is director of the military flying ground at the Palomar Aerodrome. More machines will be added and by the end of the present year it is probable that a very considerable air force will exist. ~Private Aviators.~ Bregi, Henri (A.C.F. 26) de Bruyn, A. (3) Castaibert, B. (1) Fels, T. (9) England, Gordon F.C. (British p.) Goffre, C.A. (4) Hentsch, H. (5) Mascias, A.R. (8) Melchior, E. (11) Newbury, G. (6) Origone, M.F. (10) Paillette, Marcel (French p.) Parravicini, F. (7) Roth, J.A. (2) Valleton A. (French p.) PABLO CASTAIBERT. Monoplane. | ~1911.~ | ~1912.~ | Type | _Bleriot-Hanriot_ type. | _Bleriot_ type. | ________________|__________________________|_________________________| | | | Length | 26-1/2 feet (8.15 m.) | 28 feet (8.47 m.) | Span | 29 feet (8.80 m.) | 30 feet (9.35 m.) | Area | 206 sq. ft. (19-20 m².) | 194 sq. ft. (18 m².) | Weight (total) | 705 lbs. (320 kgs.) | 617 lbs. (280 kgs.) | Motor (h.p.) | 25 Anzani | 50 Gnome | Speed (p.h.) | 46-1/2 m. (75 km.) | 50 m. (80 km.) | Note. Both fly well. Description in _Boletin de Ae.C. Argentino_. AUSTRO-HUNGARIAN. (By our Austrian Editor.) ~Aerial Societies:--~ Cesky Club Automobilistn. Aviatische Sektion. (Prague.) Deutscher Luftfahrt-Verein in Boehmen (Teplitz-Schoenau). Flugtechnischer Verein für Mähren (Brunn.). Flugtechnischer Verein in Schlesien (Troppau). Flugtechnischer Verein in Steiermark (Graz, Schmiedgasse 31). K.k. Oesterreichischer Flugtechnischer Verein (Wienstrasse 31, Vienna). Kärtner Automobil Club (Klagenfürt.) Klub Awiata (Obertynska Str. 8, Lemburg, Galicia). Magyar Automobil Club (Budapest). Magyar Athletikai Club (Abt. fur Aviatik) Budapest. Oberösterreichischer Verein f.L. in Linz (Landstr. 119, Linz). Oesterreichischer Aero Club (St. Annahoff, Vienna) (_formerly Wiener Aero Club_). Oesterreichischer Flugsport Club (Breitegasse 7, Vienna VII). K.k. Oesterreichischer Flugtechnischer Verein (Weinstrasse 31, Vienna). Oesterreichischer Luftflotten-Verein (Vienna). Oesterreichischer Wintersportklub (Vienna). _Glider club._ Verein für L. in Tirol (Innsbruck). ~Aerial Journals:--~ _Allgemeine Automobil Zeitung._ (Fleischmarkt 5, Vienna) weekly. _Allgemeine Sport Zeitung._ (St. Annhoff, Vienna) weekly. _H.P. Fachzeitung für Automobilismus und Flugtechnik._ (Vienna) weekly. _Oesterreichische Flugzeitschrift._ (Aspernplatz, Wien I) fortnightly. _Wiener Luftschiffer-Zeitung._ (St. Annahof, Vienna) fortnightly. ~Flying Grounds:--~ _Military._ ~Fischamend~ (Principal Army). ~Goerz.~ ~Zaule b. Triest.~ _Naval._ ~Pola.~ _Private._ ~Aspern bei Wien~, Vienna. ~Rakos bei Budapest.~ ~Wiener Neustadt.~ AUSTRO-HUNGARIAN AEROPLANES. ~Military Aviation: General.~ In June, 1912, a central aeronautical committee was created, under the presidency of Prince Fürstenberg, to deal with the creation of a national aerial fleet. One of the objects is the perfection of the Austrian machines and factories. About the same date, Pola was selected as a naval aviation school, and two _Paulhan-Curtiss_ hydro-avions purchased. In August the record making _Lohner_ was purchased for the Army. During September Captain Odolek tested before the military authorities a parachute of his invention; and a number were ordered. In October very strict regulations were issued as to aircraft flying over prohibited areas, a rule that any offenders would be shot at was subsequently modified. In November a _Donnet-Lerêque_ was purchased for the Navy and another ordered at the Whitehead Works, Fiume. ~Army Section.~ At the end of 1911 the Army possessed 4 monoplanes and one biplane (a _Lohner_), now available for school work. During 1912 there were acquired:-- ~20 monoplanes.~--1 _Bleriot_, 2 _Nieuport_, 15 _Etrich-Taube_, 1 _Etrich_ limousine, 1 _Deperdussin_. ~6 biplanes.~--4 _Lohner-Daimler_, 1 _Mars_, 1 _Klobucar_, (of the above the 2 _Nieuports_, 1 _Etrich_ limousine and the 4 _Lohners_ were the only ones built in Austria). ~Naval Section.~ ~4 hydro-avions~ were acquired during 1912; 2 _Donnet-Levêque_ and 2 _Paulhan-Curtiss_. ~Military Pilots.~ Banfield, Ob. Leut. Blaschke, v. Ob. Leut. Eyb, Ob. Leut. Flassig, Leut. Holeka, Ob. Leut. Kenese, Ob. Leut. Klobucar, Ob. Leut. Miller, Ob. Leut. (5) Oelwein, Ob. Leut. Perini, Leut. Petroczy, Haupt. von. Riedlinger, Ob. Leut. von. Schindler, Leut. Schünzel, Leut. Stohanzl, Ob. Leut. K (14) Umlauff, Major von. (10) Uzelac, Ob. Leut. Venczel, Leut. Welhelm, Ob. Leut. von The military centre is at Goerz, the naval one at Pola. Flying officers receive each a grant of 1,600 crowns; also 15 crowns a month for upkeep. Special certificate brings 2,000 crowns extra grant. ~Private Aviators.~ * = Superior brevet. + = Killed. Auer, J. (6) Baar, R. Baboncse, K. Banfield, K. Bauer, Dr. V.R. von. Bernat, M. *Brier, H. (18) Blaschke von. Z.R. Booms, W. (9) Bratmann, J. Buchstätter, A. Cejnek, J. Cihak, E. Ciszek, J. Czermak, J. Dworak, W. *Economo, C.F. von. (7) Fiedler, P. (19) *Flesch, J. (11) Friedmann, W. Haner, E. Hesse, M. Heyrowski, A. Hieronimus, O. Hinter, K. Hold, Hermann Huss, H. *Illner, K. Javor, J. Kaiserfeld, R. von. Kasulakow, W. Keck, Z. Kenese, W. Király, K. Klobucar, V. Knirsch, A. Kolowrat, A. Graf. (15) Kreiner, E. Lagler, B.V. Latzel, J. Lettis, A. Libowitzky, A. Mandl. Mazuranic, B. +Mosen. Nemec, H.E. von. Nittner, E. Ockermüller, H. +Petrovics, A. von. (13) Pischof. A.R. von. (2) Rabis, M. Reisner, H. Riedlinger, E. v. Kastrenberg. Rosenthal, F. +Russjan. Sablatnig, J. (12) Schartner, H. Schindler, A. Schonowsky, B. Schönpflug, F. Seidl, Franz. Simon, R. (4) Stanger, R. Steiner-Göltl, E. v. A. Stiploschek, M. *Székely, M. Tauszig, A. Teufl von. Ferland, R. Umlauff von F. Vlaicu, A. *Warchalowski, A. (1) Warchalowski, K. (8) Weiner, T. Widmer, J. +Wiesenbach, V. Woseçek, W. ~Private Aeroplanes.~ At the end of March, 1913, the total number of private aeroplanes in the country was about twenty. ETRICH Monoplanes. Etrich Flieger Werke, Wiener Neustadt. Igo Etrich was a very early experimenter in conjunction with Wels. In 1909 he produced on his own account the first _Etrich_ monoplane, a characteristic machine, which except for detail improvement, varying dimensions, etc., has not been appreciably altered since. (See Historical Section.) [Illustration: _Photo, C. Maleuit._] -----------------------------+---------------+-----------------+---------------------+ | | ~VIII 1911-12.~ | ~1912-13.~ | Model and date. | ~VII 1911.~ | 2-seater | Limousine 2-seater. | -----------------------------+---------------+-----------------+---------------------+ ~Length~ feet (m.) | 37 (11.30) | 30-3/4 (9.30) | 26-1/4 (8) | ~Span~ feet (m.) | 48 (14.60) | 42 (12.80) | 31-1/4 (9.50) | ~Area~ sq. feet (m².) | 380 (35) | 323 (30) | 280 (26) | {total lbs. (kgs.)| ... | ... | ... | ~Weight~ { | | | | {useful lbs. (kgs.)| ... | ... | ... | ~Motor~ h.p. | 120 Daimler | 100 | 60 Daimler | ~Speed~ m.p.h. (km.) | ... | ... | ... | Number built during 1912 | 5 | 2 | 2 | -----------------------------+---------------+-----------------+---------------------+ Remarks.--A number of _VII_ & _VIII_ have been sold for military purposes to the Austrian, Russian, German, and other governments. [Illustration: Etrich VIII. UAS.] [Illustration: Etrich. Limousine. _Photo, Guld._] LOHNER-DAIMLER. This firm is now amalgamated with Etrich. [Illustration] ----------------------------------+------------------+-------------------- | | ~1912-13.~ | ~1911.~ | Lohner Daimler | | Pfeilflieger. ----------------------------------+------------------+-------------------- ~Length~ feet (m.) | ... | 32 (9.70) ~Span~ feet (m.) | ... | 44-1/4 (13.50) ~Area~ sq. feet (m².) | ... | 450 (42) {total lbs. (kgs.) | ... | 926 (420) ~Weight~ { | | {useful lbs.(kgs.) | ... | ... ~Motor~ h.p. | 60 Aust. Daimler | 125 Aust. Daimler ~Speed~ m.p.h. (km.) | 50 (80) | 62 (100) Number built during 1912 | ? | 4 ----------------------------------+------------------+-------------------- Remarks.--Staggered and ~V~ shape. Late in 1911 one was purchased for the Austrian Army. In 1912 made a world's altitude. Passenger record, 4,530 metres (14,862 feet.) MERCEP Monoplanes. Mihalis Mercep, Aeroplanwerkstatte, Agram, Hungary. Russjan was connected with this firm, which built 2 biplanes to his designs in 1909. Russjan was killed in the second of these. In 1911, a _Mercep_ was built. ----------------------------------------+-----------------+----------------- | ~1911.~ | ~1912-13.~ ----------------------------------------+-----------------+----------------- ~Length~ feet (m.) | 29-1/2 (9) | 23 (7) ~Span~ feet (m.) | 34-1/3 (10.50) | 32-1/2 (10) ~Area~ sq. feet (m²) | ... | 204 (19) {machine, etc. lbs. (kgs.) | ... | 617 (280) ~Weight~ { | | {useful lbs. (kgs.) | ... | 661 (300) ~Motor~ h.p. | ... | 50 Gnome Number built | 1 | 1 ----------------------------------------+-----------------+----------------- [Illustration: Mercep. 1912-13.] WARCHALOWSKI, Biplane. Karl Warchalowski, Autoplan Werke, Odoakergasse 35, Vienna XVI. [Illustration] A machine generally on _M. Farman_ lines, but with different shaped ailerons and corners of the leading edge rounded. WHITEHEAD. Whitehead & Co., Fiume, Austria. The Whitehead Torpedo Co. has laid down plant for the production of hydro-aeroplanes. ZIEGLER Monoplane. Flugzengwerke Johann Ziegler, Vienna. --------------------------------+----------------- | ~1912-13.~ --------------------------------+----------------- ~Length~ feet (m.) | 59 (18) ~Span~ feet (m.) | 42-3/4 (13) ~Area~ sq. feet (m².) | 586 (55) { total | 1656 (750) ~Weight~ { | { useful | ... ~Motor~ h.p. | 100 Mercedes ~Speed~ m.p.h. (k.m.) | 50 (80) Number built during 1912 | 2 --------------------------------+----------------- AUSTRO-HUNGARIAN DIRIGIBLES. ~Military.~ -------+------------+-------------------+-------+----------+-------+-----------------+------------- Date | | | | Capacity | | Speed. | of | Name. | Make. | Type. | in m³. | H.P. | m.p.h. (k.p.h.) | Remarks. order. | | | | | | | -------+------------+-------------------+-------+----------+-------+-----------------+------------- | | | | | | | 1909 | ~M 1~ | Parseval P.L. 4 | n.r. | 2300 | 70 | 27 (45) | 1909 | ~M 2~ | Lebaudy-Juillot 6 | s.r. | 4800 | 100 | 23 (37) | Wrecked 1911 | | | | | | | but repaired 1910 | ~M 3~ | Körting (K.W. 1) | n.r. | 3600 | 150 | 30-1/2 (49) | 1912 | ~M 4~ | Zeppelin | | 22,000 | 450 | 47 (75) | _Building._ -------+------------+-------------------+-------+----------+-------+-----------------+------------- Military Dirigible Pilots. Cajanek, V. Grebenz, K. Hauswirth, J. Heller, S. Hofstätter, E. Macher, M. Tauber, F. Tepser, G.E. von. Weiss, H. ~Private.~ ------------------+-------------------------+-------------+-------+----------+------+------------------+---------- Date of | | | | Capacity | | Speed. | commencement. | Name. | Make. | Type. | in m³. | H.P. | m.p.h. (k.p.h.) | Remarks. ------------------+-------------------------+-------------+-------+----------+------+------------------+---------- 1910 | ~MANNSBARTH-STAGL~ | Mann-Sl. | n.r. | 8200 | 300 | 40 (65) | 1912 | ~BOEMCHER II~ | Boemcher II | | 2750 | | 25 (40) | ------------------+-------------------------+-------------+-------+----------+------+------------------+---------- Two _Renners_ and a _Boemcher I_ have ceased to exist. Private Dirigible Pilots. Adrario, K. Baumann, F. Becker, T. Berlepsch, F.F. von. Cassinone, A. Fürst, A. Hoffory, W. Hinterstoisser, F. Kaiser, K. Mannsbarth, F. Nowy, V. Richter, von. B. Stagel, H. Stratmann, W. Wagner, E. von. F. Zborowski, J. BOEMCHER II. (1912-13.) Non-rigid. +------------------+ | | | _Building._ | | | +------------------+ ~Length~, ? feet ( ? m.) ~diameter~, ? feet ( ? m.) ~volume~, 77,000 c. feet (2,750 m³.) ~Gas bags.~-- ~Motor.~-- ~Speed.~--25 m.p.h. (40 k.p.h.) ~Propeller.~-- LEBAUDY-JUILLOT 6=Military M II. (1910.) Semi-rigid. [Illustration] ~Length,~ 229-3/4 feet (70 m.) ~diameter,~ 36 feet (11 m.) ~volume,~ 170,000 c. feet (4,800 m³.) ~Gas bags.~--Austro-American Rubber Co. ~Motor.~--100 h.p. Mercedes. ~Speed.~--27 m.p.h. (45 km.) ~Propellers.~--Two 2-bladed. Remarks.--Built by the Austrian Daimler works to _Lebaudy-J._ designs. Sister to the Russian _Lebed_. KÖRTING-WIMPASSING (K-WI). Non-rigid=Military. M III. (1911.) [Illustration] ~Maximum length~, 213-1/4 feet (65 m.) ~maximum diameter,~ 34-1/2 feet (10.50 m.) ~volume,~ 127,150 c. feet (3,600 m³.) ~Total lift.~-- lbs. ( kgs.) ~Useful lift,~ lbs. ( kgs.) ~Gas bags.~--2 ballonets of 15,900 c. feet (450 m³.) ~Motors.~--2 Körting, of 75 h.p. each (= 150 h.p.) ~Speed.~--30-1/2 m.p.h. (49 km.) Made on trials March, 1911. ~Propellers.~--Two 4-bladed. Diameter, 9-3/4 feet (3 m.) ~Steering.~--_Parseval_ style. This ship is generally an adaptation of the _Parseval_ type. Accommodates 8 people. Completed 1911. Military airship. Remarks.-- [Illustration: UDS.] MANNSBARTH. Non-rigid (1911). _(Alias ~STAGL MANNSBARTH.~)_ [Illustration] ~Maximum length,~ ? feet ( ? m.) ~maximum diameter,~ ? feet ( ? m.) ~volume,~ 289,600 c. feet (8,200 m³.) ~Total lift.~-- ? lbs. ( ? kgs.) ~Useful lift,~ ? lbs. ( ? kgs.) ~Gas bags.~--Divided into 4 compartments. Ballonet in each. ~Motors.~--2 of 150 h.p. each (= 300 h.p.) ~Speed.~--40 m.p.h. (65 k.p.h.) ~Propellers.~--3. Diameter, 13 feet (4 m.) Also 1 helice. ~Steering.~--Helice used as elevator. Rudder aft. Forward and after ballonets also used as elevators, _Parseval_ style. Completed 1911. Remarks.--Built for Government, but not taken over. PARSEVAL P.L. 4. Non-rigid. = MILITARY M I. (1909.) [Illustration] ~Maximum length,~ 164 feet (50 m.) ~approx. diameter,~ 28-1/4 feet (8.60 m.) ~volume,~ ? c. feet (2,300 m³.) ~Total lift.~--5,730 lbs. (2,600 kgs.) ~Gas bags.~--Rubbered fabric by Austrian American Rubber Co. ~Motor.~--70-100 h.p. Mercedes Daimler. 1,200 r.p.m. at 70 h.p. ~Speed.~--27 m.p.h. (45 km.) made on trials. ~Propellers.~--_Parseval_ type, semi-rigid, chain driven, 3-bladed. Diameter, 11-1/2 feet (3.50 m.) ~Steering.~--_Parseval_ system. Remarks.--Built by the Austrian Motorluftschiff Gesellschaft to the _Parseval_ type C design (see Germany). Taken over by the Austro-Hungarian Army, December, 1909. Has flown 6-1/2 hours. Has risen to 1,150 metres and subsequently flown 1-1/2 hours. Carries 4 persons, _about_ 400 lbs. (180 kgs.) ballast, and fuel for 12 hours. _Station_: Fischamend. BELGIAN. (Revised by M. BRACKE, Aeronautical Engineer & Editor of "L'Aero Mécanique.") ~Aerial Societies:~-- Aero Club Belgique. Aero Club of Hainault. La Ligue Nationale Belgique. Delta Club (Kites). Ae. C. de Flanders. Ae. C. du Littoral. Ae. C. de Liege-Spa. ~Aerial Journals:~-- _La Conquête de l'Air._ (214 Rue Royale, Brussels) bimonthly, 5 francs p.a. _L'Aero Mécanique_ (Brussels edition). Chemin de St. Denis, Casteau, Mons., Belgium, 2.50 f. _L'Aviation Industrielle et Commerciale_ (monthly), Chemin de St. Denis, Casteau, Mons., 1.50 f. ~Flying Grounds:~-- Berchem. Brasschaet (Military). Camp de Casteau. (Aviation Industrielle & Commerciale). Etterbeek, near Brussels. Kiewit. St. Job (private property Baron de Caters.). BELGIAN AEROPLANES. ~Military Aeroplanes.~ At the end of 1912 the military air force consisted of three 50 h.p. Gnome _H. Farman_ 1911 military, used for instructional purposes, and twenty-four 70 h.p. Gnome _H. Farmans_ (model 1912 military), for war work: The military school is at Brasschaet, near Antwerp. Major Campion in command. The course is as follows: 1. _Theoretical course._--Lectures on meteorology, structure of aeroplanes, aviation motors, etc. 2. _Practical._--This, in addition to flight, consists of dismounting and replacing parts of aeroplanes and aerial motors, all general repairs, erecting hangars and aerial photography. The school possesses nine hangars, of which three are Bessonneau type, three wooden, and three metal. For 1913 the sum of £20,000 is to be expended for purchase of aeroplanes and the establishment of aerial squadrons at Antwerp, Liege, and Brasschaet. These are organised into six squadrons of four units each. The full complement of each squadron is eight aviators, fifteen to 20 mechanics, etc., and six citizen soldiers. The question of hydro-avions for the Congo is under consideration. ~AVIATORS.~ (The number against any name is, unless otherwise stated, the Ae. C. Belgique pilot certificate number.) Military. Broune, Lieut. (37) Cozic, R. (23) Dhanis, Lieut. (35) Heinter Poorten (47) Lebon, Lieut. (36) Moulin, E. (45) Movtens, Lieut. (19) Nelis, Lieut, (in command) (28) Robert, V. (47) Sarteel, Lieut. (26) Sournoy, J. (46) Tocy, Lieut. Private. Allard, E. (4) Armand, C. (22) Baugniet, Edmond (18) Boel Bracke, A. Camille, Amand (22) Christiaens, Joseph (7) Crombez (25) De Caters, Baron (1) De Heel, Emile (24) D'Hespel, Comte Joseph (15) De la Hault, Adhemar De Laet, E. (31) De Laminne, Chev (9) De Jonckeer (44) Depireux, Isidore (20) De Petrovsky, Alexandre (11) De Ridder, Alphonse (13) De Roy, W. (41) Descommines Deudeuner, A. (43) Dolphyn (40) Doneryos, J. (33) Duray, A. (3) Dutrieu, Mdlle. H. (27) Fischer, Jules (12) Frenay, Fernand (21) Hanciau, P. (34) Hanouilleo, P. (42) Hasen Lamblotte, F. (29) Lanser, Alfred (16) Lescart, F. (30) Mestagh, G. (39) Michez, S.R. (32) Olieslagers, Jan (5) Olieslagers, Max Orta, José Peeters Pickard Stellingwerff, J. (49) Tyck, Jules (8) Van den Born, Chas. (6) Verschaeve, Fernand (17) Verstraeten, Léon (14) The following Belgian aviators have been killed:-- +---------------------+ | Kinet, Daniel (2) | | Kinet, Nicolas (10) | | Verrept, John (38) | +---------------------+ BEHUEGHE (Bron), in Herseun. Built in 1912. A monoplane that flew very well at camp of Casteau Aerodrome during May--October. ~Motor.~--25. h.p. type Morane. New designs in wing construction, landing chassis, etc. A. BRACKE (formerly Bracke, Missyon & Co.), Casteau, Mons. In 1910, constructed the first aeroplane built by a Belgium firm--a monoplane with planes at 120. This machine has not been duplicated: but the firm have since built machines to private specifications. The only firm which has in Belgium the speciality of aeronautical patents. DE BROUCKERE, 23 rue Joardens, Brussels. Biplane. H. Farman. type. Built in 1911, modified in 1912. DE LA HAULT Adhémar de la Hault, 214 rue Royale, Brussels. In 1906, built a flapper of novel design. This was followed in 1910, by a machine on monoplane lines with one fixed plane and two flapping wings. This failed to fly, and in August, 1911, was altered into a biplane. It did not succeed, however. M. Hault is still pursuing the ornithopter question. HAREL I. Biplane. ~Length.~--49-1/4 feet (15 m.) ~Surface.~--344-1/2 sq. feet (32 m².) ~Weight.~--771 lbs. (350 kgs.), flying order. Warping wings. Monoplane tail. ~Motor.~--50 h.p. Gnome, mounted just under and forward of the upper wing. ~Tractor.~--1 Chauviere. Elevator placed 1 in front and 1 in rear, _H. Farman_ style. Rudders, 2 in rear. Completed May, 1911. For further details see _Conquete de l'Air_, July 1st, 1911. Property of M. Van der Stegen. WILLIAMS. Biplane. ~Motor.~--70 h.p. E.N.V. Generally of headless _Voisin_ type on a _Farman_ body. Completed 1911. Has flown fairly well. BELGIAN DIRIGIBLES. Military. ~1910.~ 1. LA BELGIQUE II~ (late ~I~)_ 4,000 m³. ~1911.~ 2. LA BELGIQUE III Note.--_La Belgique I_ was built in 1909 and re-built 1910. Private. VILLE DE BRUXELLES 6,000 m³. LA BELGIQUE II. (No. 1 rebuilt.) Military. [Illustration] ~Length,~ 226 feet (64.8 m.) ~maximum diameter,~ 35 feet (10.75 m.) ~capacity,~ 141,300 cubic feet (4,000 m³.) ~total lift,~ 9,921 lbs. (4,500 kgs.) ~Gas bag.~--Rubber proofed Continental fabric. Ballonet, filled by a separate motor giving 7.5 inches of water pressure. Warm air can be pumped in if required. Ballonet, 28,250 c. feet (800 m³.) ~Motors.~--2, each of 60 h.p., Vivinus, 4-cylinder, 112×130. ~Propellers.~--1 in front of the car. 285 revolutions per minute. Wood construction. ~Speed.~--25 miles per hour. 40 km. per hour. ~Planes.~--Horizontal: a gas tube bent horizontally round the tail. Vertical: vertical fins on the tail, and a long vertical keel under the gas bag. ~Car.~--A girder, square in section, tapered at both ends. Built of tubular steel. Length, 82 feet (25 m.) ~Miscellaneous.~--Built by L. Godard, France, 1909. Crew, 3 men. Accommodation for 1 passenger. Fuel for 10 hours. Greatest height attainable, 3,280 feet (1,000 m.) ~Table of weights.~-- Gas bag, complete with ballonet, valves, planes, lbs. kgs. suspension, etc 1,951 885 Propellers (2) 275-1/2 125 Blower 33 15 3 h.p. motor for blower 33 15 Motors (2) complete with gearing and shafting 1,410 640 Car 992 450 Fuel for 10 hours 738-1/2 335 Ballast 826-3/4 375 1 passenger (or ballast) 154 70 Crew (3) 463 210 Guide ropes, etc 220 100 Miscellaneous 88 40 ----- ----- _About_ 7,165 3,250 Remarks.--Reconstructed in the winter of 1909. There are two noteworthy innovations in connection with the ballonet. (1) The ballonet can be warmed by the motor. (2) In case of real emergency air can be pumped direct into the gas bag. Experiments of the utmost importance to all airships are in progress with a view to ridding the gas of this air cheaply and quickly. LA BELGIQUE III. Military. Presented 1910 to the Belgian Government by H.M. the King of the Belgians. 4,500 m³. Practically same as II, but has 3 propellers. ~Motors.~--Two 100 h.p. Germain. VILLE DE BRUXELLES. (Formerly known as LA FLANDRE.) (Astra type.) [Illustration] ~Maximum length,~ 256 feet (78 m.) ~maximum diameter,~ 41 feet (12.4 m.) ~volume,~ 212,000 c. feet (6,000 m³.) ~Total lift.~--15,763 lbs. (7,150 kgs.) ~Useful lift,~ lbs. ( kgs.) ~Gas bags.~--Continental rubbered fabric, yellow. Ballonet, 16,146 c. feet (1,500 m³.) ~Motors.~--2 Pipe motors of 100 h.p. each, placed in line with each other in the fore and aft line, and with clutches and the necessary gearing in between them. ~Speed.~--35 m.p.h. ~Propellers.~--3, namely: one at the fore end, driven by the two motors when coupled together, and two placed above and on either side of the centre of the car, for use when only one motor is running. Chauvière propellers. ~Steering.~--Vertical steering by means of a large double aeroplane fixed above the car, about a third from the front. Horizontal steering by means of a double vertical rudder above the rear end of the car. Stability is secured by the usual Astra pear shaped stabilising gas bags, with fins of rubbered cloth spread between the inner edges of these shapes. Remarks.--The distinctive feature of this ship is the arrangement of the propellers. Both motors can be coupled either on to the front propeller or on to the two rear propellers, or on to all three together, but they are actually intended only to drive the front one. On stopping either motor the other is connected to the two rear propellers, which are designed for a slower speed of translation than the front one, with the result that the running motor does not find itself overloaded as it would if the same propeller had to serve both for one and for two motors. BRAZILIAN. ~AVIATORS.~ Garos, Queiroz, Robert, Henri, Santos-Dumont, Versepuiz. There are possibly one to two aeroplanes in Brazil, but the well-known aviators live in France. Little or nothing seems doing in Brazil as yet. BRITISH. ~Aerial Societies:~-- Royal Aero Club. Aerial League. Aeronautical Society. (Premier Society, founded 1866.) Brooklands Aero Club. There were once a great many local aero clubs, but the majority of these have ceased to exist and with one or two possible exceptions all the rest are moribund. ~Aerial Journals, etc.:~-- _Aeronautical Journal._ Quarterly. 53, Victoria St., London, S.W. _Aeronautics._ 3d. monthly. 27, Chancery Lane, London, W.C. _The Aero._ 6d. monthly. 20, Tudor St., London, E.C. _Flight._ 3d. every Saturday. 44, St. Martins Lane, London, W.C. (Official organ of the R. Ae. C.) _The Aeroplane._ 1d. weekly, 166, Piccadilly, London. _All the World's Aircraft._ 21/-. Annual. 100, Southwark Street, London, S.E. and 5, Queen Victoria Street, London, E.C. In addition, the _Car Illustrated_ and the _Motor_ devote considerable space to aerial matters. ~Principal Flying Grounds:~-- ~Aldershot.~--Army school. ~Brighton,~ Shoreham Aerodrome. Aero school. ~Brooklands.~--Bristol school. ~Camber Sands,~ Rye, Sussex.--At low tide moderately hard sand and soft places. Area two miles by one mile. ~Dagenham~ (Aeronautical Society). ~Dartford Marsh.~--Vickers school. ~Dunstall Park,~ Wolverhampton. ~Eastbourne.~ Aerodrome School. ~Eastchurch,~ Sheppey.--(R. Ae. C.) 350 acres. Sheds. Members only. R. Naval school. ~Filey.~--Blackburn school. ~Hendon.~--Grahame-White, Blackburn, Bleriot, Deperdussin, Temple and Ewen schools. ~Lanark.~--Deperdussin school. ~Liverpool~ (Melly school). ~Llandudno & North Wales.~--Aerodrome. ~Mapplin Sands,~ Essex.--(Foulness). Very hard sand at low tide. Area ten miles by four miles. Property of War Office. Flying forbidden in winter. ~Salisbury Plain.~--Bristol school. Vast space available. Plenty of fairly smooth ground. Army school. ~Shoreham.~--(See Brighton). ~Upavon.~ Central flying school (R. Flying Corps.) ~BRITISH MILITARY AVIATION.~ ~Royal Flying Corps.~ In 1912 the Royal Flying Corps was instituted. It consists of two wings, navy and army, with a central flying school at Upavon, Salisbury Plain. The staff is as follows:-- _Commandant_: Paine, Capt. G.M., M.V.O., R.N. _Secretary_: Lidderdale, Asst. Paymaster J.H., R.N. _Medical Officer_: Lithgow, Capt. E.G.R., R.A.M.C. _Quarter-Master_: Kirby, Hon. Lieut. (Qr.-Mr.), V.C. _Instructor in Theory and Construction_: Cook, Lieut.-Col. H. R., R.A. _Instructor in Meteorology_: Dobson, G., Esq. _Instructors in Flying_: Fulton, Capt. J. D. B., R.A. Gerrard, Capt. E. L., R.M. Shepherd, Lieut. P. A., R.N. Trenchard, Mt. Maj. H. M., D.S.O., R. Sc. Fus. Salmond, Capt. J. M., R. Lanc. R. _Inspector of Engines:_ Randall, Eng.-Lieut. C. R. J., R.N. ~Royal Aircraft Factory.~ This is situated at Farnborough. Mervyn O'Gorman is superintendent. There are large sheds. Some _B E_ biplanes have been built here, but the principal object of the factory is understood to be repairs and maintenance. ~Naval Wing Royal Flying Corps, Aeroplane Section.~ There is a special Air Department at the Admiralty with Captain M. F. Sueter, as Director, Commander O. Schwann and Lieut. C. L'Estrange-Malone, as Assistants, Eng. Lieut. G. W. S. Aldwell, as Eng. Inspector. Officers are graded Flying Officers, then Flight Commanders, thence to Squadron Commanders. The flying school is at Eastchurch, Sheppey. Commander Sampson, S.C., in command. There are at present four air stations: (1) Isle of Grain, (2) Calshot, (3) Harwich, (4) Yarmouth. At the end of March, 1913, the total number of aeroplanes including those on order, school machines, etc., was about 32; of which about 16 were effective for war purposes or available at short notice. These machines were as follows:-- 7 monoplanes (= 1 Bleriot, 2 Deperdussin, 1 Etrich, 1 Nieuport, 2 Short). 15 biplanes (= 1 Avro, 2 Bristol, 1 Breguet, 1 Caudron, 2 H. Farman, 1 M. Farman, 5 Short, 2 Sopwith). 10 hydro-avions (= 1 Astra, 1 Avro, 2 Borel, 1 Donnet-Leveque, 1 H. Farman, 1 M. Farman, 3 Short). The _personnel_ is as follows (number after names is the R. Ae. C. brevet number):-- ~Squadron Commanders.~ Gerrard, Capt. F. L., R. M. (76) Gordon, Capt., R. M. (161) Gregory, Lieut. (75) L'Estrange-Malone, Lieut. C. (195) Longmore, Lieut. Sampson, Com. C. R. (71) Shepherd, Lieut. P. A. (215) ~Flight Commanders.~ Courtney, Lieut. I. T. (R. M.) Grey, Lieut. Spencer (117) Risk, Capt. C. E., R. M. (303) Seddon, Lieut. J. W. (296) ~Flying Officers.~ Those marked * are under instruction, not yet graded. *Agar, Lieut. A.W.S. Babington, Lieut. J.T. (408) Bigsworth, Lieut. A.W. (390) *Bobbett, Boatswain H.C. (334) Bowhill, Lieut. F.W. (397) *Brodribb, Lieut. F.G. (481) Courtney, Lieut. I.T., R.M. Courtney, Lieut. C.L. (328) *Davies, Lieut. R.B. (90) *Edmonds, Lieut. G.H.K. *Fawcett, Capt. H., R.M. *Gaskell, Lieut. A.B. *Hathorn, Lieut. G.H.V., R.M. Hewlett, Sub. Lieut., F.E.J. Kennedy, Lieut. J.B. *Maude, Lieut. C.E. *Noyes, Asst. Paymaster, C.R.F. Oliver, Lieut. E.A. (425) *Parker, Asst. Paymaster E.B. (415) Rathbone, Lieut., C.E., R.M. Ross, Lieut. R.P. (422) *Sitwell, Lieut. W.G. Travers, Lieut. J.L. Vernon, Lieut. H.D. (404) Wildman-Lushington, Lt. G.V., R.M.A. The following R.N. officers and men are aviators employed in various duties at the Admiralty, at the Central Flying School or at Eastchurch:-- Aldwell, Eng. Lieut. G.W.S. Andrews, J.C. (372) Ashton, Ldg. Seaman Batemad, Able Seaman P.E. (446) Briggs, Eng. Lieut. E.F. Brownridge, Carp. Collins, Art. Eng. J.V. Cresswell, Lieut. T.S., R.M. (420) Deakin, A. (333) Gerrard, Capt., R.M. (76) L'Estrange-Malone, Lieut. C. (195) Lidderdale, Asst. Paymaster H.J. (402) O'Connor, Art. Eng. T. (280) Paine, Capt. G.M. (217) Randall, Eng. Lieut. (81) Schwann, Com. O. (203) Scarff, Art. Eng. F.W. Shaw, Shipwright D. (465) Shepherd, Lieut. P. (288) Susans, F. (380) Wells, Staff. Surg. H.V. The following have privately secured pilot certificates in the years mentioned but are not employed in the R.F.C. for aeroplane work. Some of them, however (D), are employed in the airship section:-- ~1911.~ Bower, Lieut. J.A. (161) Clark-Hall, Lieut. (127) Leveson-Gower, Com. Williamson, Lieut. (150) Williamson, Lieut. H.A. (160) ~Naval. 1912.~ Blatherwick, Lieut. G. (450) Brown, Com. A M.T. (345) Edwards, Lieut. C.H.H. D Freeman Williams, Lt. F.A.P.(202) Head, Lieut, G.G.W. (191) Hooper, Sub. Lt. C.W.W. (382) Johnson, Capt. C.D. D Masterman, Com. E.A.D. (Ae.C.F.) Prickett, Lieut. C.B. (381) Trewin, Asst. Paymaster (294) D Usborne, Lieut. N.F. (449) Wheeler, Mid. N.F. (370) ~Naval. 1913.~ D Boothby, Lieut. F.L.M. (Ae.C.F.) Brady, B.J.W. (394) Brown, Lieut. A.C.G. (398) Dobie, Lieut. W.F.R. (448) Fitzmaurice, Lieut. R. (447) Freeman, S.T. (393) Littleton, Sub. Lieut. H.A. (405) Picton-Warlow, Lieut. W. (451) Ross, Lieut. R.P. (422) ~Army Wing Royal Flying Corps, Aeroplane Section.~ The Army wing has its headquarters at S. Farnborough, its constitution being as follows:-- 1st squadron (airships or kites) see Dirigible Section. 2nd " (aeroplanes) base at Montrose. 3rd " " " " Salisbury Plain. 4th " " " " S. Farnborough. (Four more aeroplane squadrons _pro._) An aeroplane squadron nominally consists of 18 aeroplanes (9 in service, 9 remounts). At the end of March, 1913, the total number of aeroplanes, including those on order, school machines, etc., was about 110, of which about 50 (including some monoplanes not in use) were effective for war purposes or available at short notice. The total of 110 was thus made up:-- 22 monoplanes (= 2 Bleriot, 4 Bristol, 5 Deperdussin, 4 Howard-Flanders, 1 Martinsyde, 6 Nieuport). 86 biplanes (= 4 Avro, 22 B.E. type,[A] various makers), 2 Breguet, 2 Caudrons, 30 Farman (various types), 6 Short--and about 20 Avro or Farman or Short not delivered. ~Squadron Commanders.~ Brooke-Popham, Capt. H.R.M. (108) Burke, Capt, C.J. (46) (Ae.C.F. 260) Carden, Lt. A. D. (239) Cook, Lt.-Col. H. R. (42) Fulton, Major J. D. B. (27) Raleigh, Capt. G. H. (196) Trenchard, Major H. M. (270) ~Flight Commanders.~ Allen, Capt. C. R. W. (159) Beor, Lt. B. R. W. (R.A.) (185) Becke, Capt. J. H. W. (236) Connor, Lt. D. G. (54) Fox, Lt. A. G. (176) Higgins, Major J. F. A. (R.A.) (264) Longcroft, Lt. C. A. H. (192) Reynolds, Lt. H. R. P. (R.E.) Salmond, Capt. J. M. Webb-Bowen, Capt. T. I. (242) ~Flying Officers.~ Abercromby, 2nd Lt. R. O. (134) Allen, Lt. D. L. (318) Anderson, Lt. E. V. (247) Atkinson, Lt. K. P. (267) Barrington-Kennett, Lt. B. H. (Adjutant) (43) Beatty, Capt. W. D. (89) *Birch, Lt. W. C. K. (375) Board, Capt. A. G. S. (36) Boyle, Lt. the Hon. D. G. Burchardt-Ashton, Lt. A. E. Burroughs, Lt. J. E. G. Carmichael, Lt. G. I. (316) *Chinnery, Lt. E. F. (211) Cholmondeley, Lt. R. (271) *Christie, Lt. A. (R.A.) (245) Conran, Lt. E. L. (342) *Corbalis, Lt. E. R. L. Darbyshire, Capt. C. (257) Dawes, Lt. L. (228) Dawes, Capt. G. W. P. (17) *Gill, Lt. N. J. (174) Glanville, Lt. H. F. (307) Gould, 2nd Lt. C. G. S. (282) Harvey, Lt. E. G. *Harvey-Kelley, Lt. H. D. Herbert, Capt. P. L. W. (244) Holt, Lt. A. V. (312) Hubbard, 2nd Lt. T. O. B. (202) Hynes, Lt. G. B. (R.A.) (40) James, Lt. B. T. Joubert, de la F. Lt. P. B. (280) Lawrence, Lt. W. MacDonnell, Capt. H. C. (273) MacClean, Lt. A. C. H. *Mapplebeck, Lt. G. W. C. (386) Martyn, Lt. R. B. Mead, Sergt. J. (475) Mellor, Capt. C. (155) *Mills, Lt. R. P. (377) Moss, Bt.-Major L. B. (241) *Musgrave, Capt. H. (R.E.) *Mulcahy-Morgan, Lt. T. W. *Noel, Lt. M. W. (416) Pepper, Lt. J. W. (98) *Picton-Warlow, Lt. W. (451) Playfair, 2nd Lt. P. H. L. (283) *Pretyman, Lt. G. F. (341) Porter, Lt. G. T. (R.A.) (169) Pryce, Hon. Lt. W. J. D. (Qr.-mr.) *Read, Lt. A. M. (336) *Rodwell, Lt. R. M. Roupell, 2nd Lt N. S. (237) Shepherd, Capt. G. S. (215) Soames, Lt. A. H. L. Small, Lt. F. G. D. (429) *Small, Lt. R. G. (343) Smith-Barry, 2nd Lt. R. R. (161) Stopford. Lt. G. B. *Todd, Lt. E. (185) Thompson, Lt. A. B. Tucker, Capt. F. St. G. *Vaughan, 2nd Lt. R. M. Wadham, 2nd Lt. V. H. N. (243) Waldron, Lt. F. F. (260) Wanklyn, Lt. F. A. (284) ~Reserve.~ Ashmore, Major E. B. (281) Bell, 2nd Lt. C. G. (100) De Havilland, 2nd Lt. G. (53) Hartree. 2nd Lt. A. (214) Henderson, Col. D. (118) Marks, Lt. C. H. (83) Pizey, 2nd Lt. C. P. (61) Salmond, Capt. W. G. H. Smith, Lt. S. C. W. Unwin, Lt. E. F. Warter, 2nd Lt. H. de V. (107) ~Special Reserve.~ (_2nd Lieuts. on probation._) Biard, H. C., de la F. (218) Busteed, H. R. (194) Charteris, R. L. (197) Cutler, H. D. (189) Davies, E. K. (22) *Fuller, E. N. (325) Fuller, H. C. (Ae. C. F.) Gibson. W. E. (129) Hammond, J. J. (32) Humphreys, G. N. (390) Lerwill, F. W. H. Metford, L. S. (146) Perry, E. W. C. (130) Rickards, G. B. (400) Sippe, S. V. (172) Spratt, N. C. (339) Ware, D. C. Wilson, C. D. (Ae. C. F. 136) *Wilson, C. W. (329) Young, D. G. (207) The following have qualified privately, R. Ae. C. brevets, but are not at present employed in the Aeroplane Section:-- ~1910.~ Gibb, Lt. (10) Snowden Smith, Lt. (29) Watkins, Lt. H. E. (25) Wood, Capt. H. F. (37) ~1911.~ Blacker, Lt. (12) Cross, Lt. (151) Dickson, Capt. (Ae. C. F. 260) Harford, Lt. (152) Harrison, Capt. (158) Hoare, Capt. (126) Hooper, Lt. (149) Hutchinson, Capt. Steele (143) Manisty, Lt. G. (135) Pitcher, Capt. (125) Sebag-Montefiore, Lt. (93) Smeaton, Lt.-Col. (115) Strover, Lt. E. J. (145) ~1912.~ Agnew, Capt. C. H. (240) Alston, Capt. R. C. W. (255) Ashton, Lt. A. E. B. (201) Bannerman, Major Sir A. (213) Boger, Capt. R. (335) Borton, Lt. A. E. (170) Boyle, Capt. M. (241) Brodigan, Lt. F. J. (200) Broke-Smith, Capt. D. W. (204) Bulkeley, Lt. H. T. (246) Carfrae, Lt. G. T. (188) Chamier, Capt. J. A. (340) Cordner, Capt. R. H. L. (277) Ellington, Capt. E. L. (305) Empsom, Lt. J. (387) Fielding, L. H. C. (212) Fletcher, Lt. (229) Hanlon, Lt. D. R. (311) Jones, Lt. B. T. (230) Lewis, Lt. D. (216) Mackay, Lt. M. E. (177) Mackworth, Lt. J. D. (209) Martin-Barry, Lt. (Ae. C. F.) McCudden, Capt. J. H. (269) Miller, Capt. G. R. (313) Murray, Lt. R. G. H. (320) Nicholas, Capt. C. P. (266) Penn-Gaskell, Lt. L. de C. (308) Percival, Lt. D. (226) Pollok, Lt. R. V. (379) Powell, Capt. D. W. (389) Price, Capt. C. L. (299) Rawson, Lt. K. (249) Reilly, Lt. H. L. (252) Ridd, Corporal F. (227) Roger, Capt. R. (335) Stott, Capt. J. N. J. (373) Styles, Lt. F. E. (338) Thomas, Staff-Sergt. (276) Trevenon, Lt. B. J. (230) Weeding, Capt. (182) Winfield-Smith, Lt. S. G. (187) Worthington-Wilmer, Lt. F. M. (254) ~1913.~ Archer, Lt. R. H. (434) Bayly, Lt. C. G. G. (441) Bruce, Sergt. W. R. (467) Bourke, Lt. U. J. D. (479) Cameron, Major N. J. (478) Chidson, Lt. M. R. (471) Crogan, Lt. F. J. L. (460) Harrison, Lt. Hawker, Lt. L. G. (435) Hordern, Lt. L. C. (440) Hosking, Lt. C. G. (472) Hunter, Sergt. Kemper, Sergt. K. (444) Lee, Lt. C. F. (431) Maclean, Lt. L. L. (427) Marshall, Lt. R. (470) McMullern, Lt. J. D. (436) Merrick, Major G. C. (484) Mitchell, Lt. W. G. S. (483) Read, Lt. W. R. (463) Rees, Lt. Col. W. B. (392) Stafford, Sergt. W. G. (438) Street, Sergt. E. J. (439) Thomas, Sergt. Major Vagg, Sergt. H. R. (443) The above figures are mainly taken from _The Aeroplane,_ 1st May, 1913. * = under instruction; not yet graded. PRIVATE AVIATORS. (The number against any name is, unless otherwise stated, the R. Ae. C. pilot certificate number). _To end of_ ~1911.~ Abbott, C. R. (101) Aitken, A. H. (56) Anderson, J. A. (164) Archer, Ernest (Ae. C. F. 214) Ballard, F. M. (151) Barber, H. (30) Barnes, G. A. (16) Blackburn, H. (79) Bowens, R. G. (39) Boyle, Hon. Alan (13) Bretherton, John (136) Breton, J. (136) Brown, H. B. (109) Chataway, J. D. (167) Challenger, G. H. (58) Chambers, C. F. M. (168) Cockburn, G. B. (5) Cockerell, P. (132) Cody, S. F. (9) Conway-Jenkins, F. (74) Crawshay, R. (133) Colmore, G. C. (15) Dacre, G. B. (162) Darroch, G. R. S. (59) Dolphin, W. H. (82) Dunkinfield-Jones (138) Ducroq, M. (23) Dyott, G. M. (114) Driver, E. F. (110) Egerton, M. Hon. (11) England, Gordon (68) Esterre, C. R. (Ae. C. F. 259) Ewen, W. H. (63) Fleming, H. R. (69) George, A. E. (19) Graham-White, Claud (6) (Ae. C. F. 30) Gresswell, C. H. (26) Grey, W. H. de (107) Halse, E. (131) Hamel, Gustav (64) (Ae. C. F. 358) Harding, Howard (Ae. C. F. 213) Harrison, Eric (131) Hewlett, Mrs. (122) Higginbotham, Gerald (96) Hilliard, W. M. (102) Hubert, Charles (57) Hotchkiss, E. (87) Houdini, Harry Hucks, B. G. (91) Hunter, A. (137) Johnston, St. Croix, P. G. (41) Johnstone, W. Barnley (103) Kemp, R. C. (80) Keith-Davies, E. King Knight, Archibald (60) Lawrence, W. (113) Longstaffe, J. L. (140) Loraine, Robert (Ae. C. F. 126) Low, A. R. (34) Macdonald, L. F. (28) Maron, Louis (62) Martin, J. V. Mrs. (55) Macfie, R. (49) McArdle, W. E. (Ae. C. F.) M'Clean, F. K. (21) Mellersh, O. S. (155) Melly, H. G. (Ae. C. F.) Moorhouse, W. B. R. (147) Morrison, O. C. (46) Moore-Brabazon, J. (1) Noel, Louis (116) Ogilvie, A. (7) Pashley, Cecil L. (106) Pashley, E. C. (139) Paterson, C. E. (38) Paul, E. A. (Ae. C. F.) Percival, N. S. (111) Petre, H. A. (128) Philpott, R. W. (81) Pixton, H. (50) Prentice, W. R. (67) Radley, J. (12) Rawlinson, A. (3) Raynham, F. P. (85) Roe, A. V. (18) Salmet, H. (99) Sassoon, E. V. (52) Santoni, L. Singer, A. M. (8) (Ae. C. F. 24) Slack, R. B. (157) Smith, S. E. (33) Smith, W. W. (Ae. C. F.) Spencer, H. (124) Somers-Somerset (Ae. C. F. 151) Sopwith, T. (31) Stanley-Adams, H. (97) Stark (Ae. C. F. 110) Stocks, Mrs. C. de B. (153) Thomas, J. H. (51) Travers, J. L. (86) Turner, C. C. (70) Turner, L. W. F. (66) Valentine, J. (47) Watt, W. O. (112) Weir, J. D. (24) Weston, John (Ae. C. F.) Wickham, R. F. (20) Woodward, G. A. T. (A _To end of_ ~1912.~ Barnwell, R. H. (278) Beech, A. C. (Ae. C. F.) Bendall, W. (180) Bettington, A. V. (326) Birch, E. (322) Brock, W. L. (285) Cheeseman, W. E. (293) Featherstone, W. (384) Fowler, F. H. (221) Gates, R. T. (225) Garne, T. (173) Geere, A. E. (310) Gill, R. W. R. (258) Hall, H. W. (332) Hall, J. L. (291) Hardman, W. L. (323) Harrison, W. J. (275) Hawker, H. G. (297) Hedley, W. S. (274) Hewitt, V. (302) Higginbotham, V. C. (317) Holyoake, R. G. (268) James, J. H. (315) James, H. H. (344) Kershaw, R. H. (248) Lister, R. A. (250) Nesham, H. P. (219) Nevill, M. R. (223) Manton, M. D. (231) Meredith, C. W. (193) Merriam, F. W. (179) Parr, S. (184) Payze, Arthur (337) Potet, A. (224) Prensiel, G. (198) Simms, R. H. (261) Stodart, Dr. D. E. (321) Summerfield, S. (292) Sutton, E. F. (295) Sweetman-Powell, H. (251) Taylor, V. P. (376) Tremlett, L. A. (208) Wood, V. G. (171) Wynne, A. M. (314) Wright, H. S. (331) Yates, V. (306) ~1913~ (Brevets from 400 onward). Andreas, F. G. (477) Barron, J. C. (480) Hodgson, W. P. (433) Kehrmann, J. C. (420) King, R. A. (482) Lane, H. T. G. (418) Lawford, E. H. (442) Macandrew, H. E. W. (401) Macneill, W. (Ae. C. F.) McNamara, J. C. (445) Minchin, F. R. (419) Muller, P. M. (432) Temple, G. L. (424) Thompson, A. B. A. (452) Tower, H. C. (466) Rainey, T. H. (474) Russell, A. L. (406) Stewart, H. (473) Strain, L. H. (476) The following British aviators have been killed: +-------------------------------------+ | 1910. | | Rolls, Hon. C. (2) | | | | 1911. | | Benson, R. | | Cammell, Lieut. (45) | | Grace, Cecil (4) | | Napier (104) | | Oxley, H. (78) | | Ridge, T. (119) | | Smith, V.[B] | | | | 1912. | | Allen, D. L. (183) | | Astley, J. H. D. (48) | | Bettington, Lt. C. A. (256) | | Campbell, Lindsay (220) | | Clark, Miss J. | | Fenwick, R. C. (35) | | Fisher, E. V. B. (77) | | Gilmour, Graham (Ae. C. F.) | | Hardwick, A. | | Hamilton, Capt. P. (194) | | Hotchkiss, Lieut. | | Loraine, Capt. (154) | | Petre, Edward (259) | | Parke, Lieut. W. (73) | | Wilson, St. Serg. (232) | | Wyness-Stuart, Lt. A. | | | | 1913. | | Arthur, Lt. Desmond (233) | | Berne, Paym'st'r (R.N.) | | England, G. (301) | | Macdonald, L. F. | | Rogers-Harrison, Lieut. L. C. (205) | +-------------------------------------+ BRITISH AEROPLANES ~A~ AIRCRAFT FACTORY. Royal Aircraft Factory, Farnborough, near Aldershot. For a long time this establishment had been engaged in dirigible construction and repairs. In 1911 it was decided to expand it in connection with the Royal Flying Corps. Its precise functions are somewhat uncertain. Its nominal main purpose is the repair, etc., of Service Aircraft. During 1912, however, it turned out several machines to a design of its own, known as the _"B.E."_ This design was at one time regarded as confidential; but subsequently duplicates were built by private contractors, and the design illustrated below, published by the Advisory Committee for Aeronautics. [Illustration: B.E. type. R.A.F. UAS.] ~Length,~ 29-1/2 feet (9 m.) ~Span.~--36-3/4 feet (11.20 m.) ~Area.~--374 sq. feet (34-3/4 m².) ~Weight.~-- ~Motor.~--75 h.p. Renault and others. ~Speed.~-- AERO'S Ltd. St. James' Street, Norwich Union Buildings, Piccadilly, London, S.W. Established 1912 for the sale of all parts and accessories; also for the sale of second hand aeroplanes and motors of all makes. Does not construct at present. AIRCRAFT MANUFACTURING Co., Ltd. 47, Victoria Street, London, S.W. Works: Hendon, London, N.W. This company established in 1912, holds all the British rights for the _H. & M. Farman_ types. It constructs in England all _Farman_ types at its own works. (See _Farman_, French). AVRO. Aeroplanes. A. V. Roe & Co., Clifton Street, Miles Platting, Manchester; also Shoreham, Sussex. A. V. Roe designed his first machine, a biplane, in 1906. It was the first British machine to leave the ground. He then experimented with triplanes in Lea Marshes, where he managed to fly with only 9 h.p. in 1908-9. In August, 1910, built _Roe III_, and in September, _Roe IV_, also triplanes (see 1911 edition for full details). In 1911 he abandoned triplanes for the _Avro_ biplane. School: Shoreham. [Illustration: Type D (1911). _Photo, Alan H. Burgoyne, Esq., M.P._] ----------------------------------------+-------------------+----------------+----------------+-------------------+-------------------- | ~D 1911-12.~ | ~E 1912.~ | ~F 1912.~ | ~G 1912-13.~ | ~E 1912-13.~ Model. | 2-seater | 2-seater | Totally | Totally | Hydro-biplane. | biplane. | biplane. | enclosed | enclosed | | | | mono. | biplane. | ----------------------------------------+-------------------+----------------+----------------+-------------------+-------------------- ~Length~ feet (m.) | 31 (9.45) | 29 (8.84) | 23 (7) | 29 (8.84) | 33 (10) ~Span~ feet (m.) | 31 (9.45) | 36 (11) | 28 (8.50) | 36 (11) | 47-1/2 (14.50) ~Area~ sq. ft. (m².) | 279 (26) | 335 (32) | 158 (14-1/2) | 335 (32) | 478 (34-1/2) {empty lbs. (kgs.) | 800 (363) | 900 (482) | 550 (249) | 1191 (540) | 1740 (789) ~Weight~ { | | | | | {fully loaded, lbs. (kgs.) | ... | 1300 (589) | 800 (363) | 1700 (771) | 2700 (1224) ~Motor~ h.p. | 35, any make | 50 Gnome | 40 Viale | 60 Green | 100 Gnome ~Speed~ m.p.h. (km.) | 48 (78) | 61 (97) | 65 (105) | 61.8 (100) | 55 (90) Number built during 1912 | several | 6 | 1 | 1 | 1 ----------------------------------------+-------------------+----------------+----------------+-------------------+-------------------- Remarks.--Of the above, 4 of the 50 Gnome E type were purchased by the British Royal Flying Corps, and one by the Portuguese Government; the other went to Windermere on January, 1913, for hydro experiments. Climbing speed of this type is 440 feet per min. (134 m.) Dual control fitted. D type are no longer being built. Climbing speed of F type, 300 feet per min. (91.5 m.) Gliding angle, 1 in 6. G has a gliding angle 1 in 6.5. On October 24th, 1912, made British record to date, 7'31-1/2" (=450 miles). The hydro. was delivered to the British R.F.C. naval wing early in 1913. [Illustration: Avro. Type D (1911-12). U.A.S.] [Illustration: E type Standard 50 h.p. Avro Biplane.] +----------------------------------------------------------------------+ | | | _No suitable photo available._ | | The machine is on usual lines. The first had a single float, but now | | two floats are used. | | | +----------------------------------------------------------------------+ E type 100 h.p. Avro Hydro-biplane. [Illustration: F type Enclosed Avro Mono.] [Illustration: G type Enclosed Avro Biplane.] ~B~ BLACKBURN Aeroplanes. Blackburn Aeroplane Co., Balm Road, Leeds. Blackburn produced his first machine early in 1910 (see 1911 edition for details). In the latter part of that year he designed the machine which ultimately developed into the _Blackburn_ military. In 1911 other types were produced, all being fitted with the patent Blackburn triple control. School at Filey Hucks has been the principal _Blackburn_ flyer. The type has also been very successfully flown by naval officers. Capacity of works: about 24 a year. ------------------+------------------------+------------------------+------------------------------- | ~1912-13.~ | ~1912-13.~ | ~1913.~ | Military. 2-seater. | Military. 1-seater | Hydro-biplane. | | | 2-seater ------------------+------------------------+------------------------+------------------------------- ~Length~ | 32 feet (9.75 m.) | 25 feet (7.60 m.) | 33 feet (10 km.) ~Span~ | 40 feet (12.20 m.) | 32 feet (9.75 m.) | 44 & 36 ft. (13.40 & 11 km.) ~Area~ | 276 sq. ft. (26 m².) | 195 sq. ft. (18 m².) | 410 sq. ft. (38 m².) ~Weight~ (total) | ... | 750 lbs. (340 kgs.) | 1250 lbs. (507 kgs.) ~Motor~ h.p.| ... | 50 Gnome. | 80 Gnome or 100 Anzani ~Speed~ | 55-65 m. (90-105 km.) | 60 m. (97 km.) | 65 m. (105 km.) ------------------+------------------------+------------------------+------------------------------- Notes.--Petrol for 5 hours (higher endurances can be fitted). Specially designed for military work--all steel construction. All parts unwelded to admit of rapid displacement. Clear observation provided for. ~Fuselage.~--The fuselage is ~V~ shaped and constructed of weldless steel tubing in the form of a lattice girder. The main longitudinals are of round section; cross members, oval section. Connections are not welded but made with strong steel clips so that should any member become damaged a new one can be readily arranged. The front portion is covered with sheet metal giving additional strength and reducing the head resistance. Stream line form tapering towards the rear which is covered with fabric. ~Chassis.~--Two long skids connected up to fuselage by metal struts. Each skid borne by a pair of wheels, axle held down by elastic shock absorbers. On the axle of the wheels are fitted steel springs which take side thrust. Each pair of wheels held by radius rods forming a bogie. ~Control.~--Patent Blackburn triple, independent or simultaneous on hand wheel, but special foot control for rudder is fitted if desired. In 1912, five machines were built, of which two were of the mil. model. Others, non-military models (see last edition.) [Illustration: Military monoplane.] [Illustration: BLACKBURN. Military Type. Two-seater. UAS] [Illustration: BLACKBURN. Naval Type.] BRISTOL. The British & Colonial Aeroplane Co., Ltd., Filton House, Bristol. Founded 1910. Capital (1913), ?. Have very extensive works (area. ? sq. feet) on the outskirts of Bristol, employing over 300 men, where they manufacture to their own designs practically every type of flying machine. Flying grounds: Salisbury Plain, Brooklands. 105 Royal Aero Club certificates won on _Bristol_ machines during 1912 (of which 86 were officers of His Majesty's Forces). ----------------------------------+-----------------+-----------------+-----------------+----------------- | ~Military~ | ~Military~ | | | ~mono.~ | ~mono.~ | ~Tractor~ | ~School~ | 2-seater. | 2-seater. | ~biplane~ | ~mono.~ | 80 h.p. | 50 h.p. | ~1913.~ | Side by side. | ~1912-13.~ | ~1912-13.~ | | ----------------------------------+-----------------+-----------------+-----------------+----------------- ~Length~ feet (m.) | 28-1/4 (8.60) | 23-2/3 (7.20) | 27-3/4 (8.47) | ~Span~ feet (m.) | 42-1/3 (12.90) | 39-1/3 (12) | 34-1/3 (10.44) | ~Area~ sq. feet (m².) | 221 (20.6) | 226 (22) | 370 (34.4) | ~Total~ {machine, lbs. (kgs.) | 1719 (771) | 1323 (600) | 1764 (800) | ~weight~ {useful lbs. (kgs.) | 710 (322) | 551 (250) | 1200 (544) | ~Motor~ h.p. | 80 Gnome | 50 Gnome | 70 Renault | 50 Gnome ~Speed~ {max. m.p.h. (km.) | 73 (118) | 62 (100) | 70 (112) | {min. m.p.h. (km.) | ... | ... | ... | ~Endurance~ hrs. | 4 | 3-4 | ... | Number built during 1912 | ... | ... | ... | ----------------------------------+-----------------+-----------------+-----------------+----------------- Notes.--~Monoplane:~ Box section fuselage convex on bottom side to minimise resistance. Mounted on 2 wheels and 2 skids with smaller wheels attached at the forward end. Bristol tractor. ~Biplane:~ Box section fuselage, convex on top and bottom sides. Mounted as monoplane. Bristol tractor. This machine is the latest production of the Bristol Co., and has proved an exceptionally successful flyer. Designed by M. Coanda. [Illustration: 80 h.p. monoplane.] [Illustration: 70 h.p. biplane. UAS.] BLERIOT Aeronautics. Belfast Chambers, 156, Regent Street, London, W. School: Hendon. British office of the _Bleriot_ firm (see France). BRITISH BREGUET CO., 1, Albemarle Street, Piccadilly, London, W. Works and offices: 5, Hythe Road, Cumberland Park, Willesden, London, N.W. Established 1912. Constructs in England _Breguet_ models, some of which are beginning to vary in detail from the originals (see France). BRITISH CAUDRON. (See _Ewen_.) BRITISH DEPERDUSSINS. British Deperdussin Aeroplane Co., Ltd., 39, Victoria Street, Westminster, London, S.W. School: Hendon. Chairman: Admiral The Hon. Sir E. R. Freemantle, G.C.B., C.M.G. Managing Directors: Lieut. J. C. Porte, R.N., D. Laurence Santoni. Secretary: N. D. Thompson. This firm handles the French models of _Deperdussins_, but has in addition a special hydro-aeroplane of its own, of which one was built in 1912. Details of this special machine are:--~Length,~ 27 feet 10 inches (8.50 m.) ~Span,~ 42 feet (12.80 m.) ~Area,~ 290 sq. feet (27 m².) ~Weight,~ total, 1,800 lbs. (816 kg.); useful, 1,250 lbs. (566 kg.) ~Motor,~ 100 h.p. Anzani. ~Speed,~ 67 m.p.h. (110 k.m.) Other models sold by the firm are of French type exactly (see France). BRITISH DONNET-LEVEQUE. Handled by Aeros, Ltd., 39, St. James' Street, Piccadilly, London, S.W. Company forming March, 1913 (see France). Works and school at Shoreham. BRITISH FARMANS. (See _Aircraft Co._) BRITISH HANRIOTS. Hewlett & Blondeau, Omnia Works, Vardens Road, Clapham Junction, London, S.W. Construct all types of _Hanriot_ machines (see France), also build to private specifications, and deal in accessories generally. BRITISH NIEUPORTS. Company forming 1913. Representative: M. Bonnier, 2, Goulders Green Crescent, London, N.W. ~C~ CODY. Cody flying school, Farnborough. Cody commenced experiments with kites in very early days on behalf of the British Admiralty. Subsequently built the first British Army dirigible, and an experimental Army aeroplane. In 1909, his direct connection with the Army ceased. A _Cody I_ was built in 1908. A _Cody II_ was completed June 1910. The _special features_ of both were: very strong construction, great size (_II_ had area of 857 sq. feet), ailerons. Later types, except that warping is substituted for ailerons, do not differ very materially except in minor details. All wood construction. ---------------------------------+-----------------+-------------------+------------------- | ~1911.~ | ~1913.~ | Model. | 4-seater | 4-seater | May, ~1912.~ | biplane. | biplane. | Monoplane. ---------------------------------+-----------------+-------------------+------------------- ~Length~ feet (m.)| 38 (11.60) | 38 (11.60) | 38 (11.60) ~Span~ feet (m.)| 43 (13) | 43 (13) | 43-1/2 (13.25) ~Area~ sq. feet (m².)| 484 (44-3/4) | 483 (44-3/4) | 260 (19) {total lbs. (kgs.)| 1900 (862) | 1900 (862) | 2400 (1088) ~Weight~ { | | | {useful lbs. (kgs.)| 1000 (453) | 1000 (453) | 700 ~Motor~ | 60 Green, later | 120 Aust. Daimler | 120 Aust. Daimler | a 100 Green | | {max m.p.h. (km.)| 70 (115) | 75 (120) | 83 (135) ~Speed~ { | | | {min m.p.h. (km.)| 47 (75) | 47 (75) | 58 (95) Number built to end of last year | 1 | 1 | 1 ---------------------------------+-----------------+-------------------+-------------------- Remarks.--The 1911 is the famous _Cody_, which, as a 60 h.p., won both Michelin 1911 prizes, and completed the _Daily Mail_ circuit. As a 100 h.p. it won the 1912 Michelin cross-country. By the end of 1912 it is said to have flown a total of 7000 miles. The 1913 is practically a duplicate with a more powerful engine. _Special features_ of the biplanes, maximum camber to lower plane. Both planes equal span. Very strong landing gear. Propeller chain driven: 1-3/4 to 1 gearing. In February, 1913, four biplanes were ordered for the British Army. Cody lists a mono. for 1913 a trifle longer than the above; also five variations on the biplane of from 35 to 160 h.p., which can be built if required. [Illustration: Biplane.] COVENTRY ORDNANCE. The Coventry Ordnance Works, Ltd., Coventry. London office: 28, Broadway, Westminster, S.W. Established 1912. Capacity: 50 machines a year without difficulty. ----------------------------+--------------+ | ~1912.~ | | Model 10. | ----------------------------+--------------+ ~Length~ feet (m.)| 29 (8.80) | ~Span~ feet (m.)| 56 (17) | ~Area~ sq. feet (m².)| 630 (58) | {total lbs. (kgs.)| 1900 (861) | ~Weight~ { | | {useful lbs. (kgs.)| 800 (362) | ~Motor~ h.p.| 100 Gnome | {max. m.p.h. (km.)| 60 (97) | ~Speed~ { | | {min. m.p.h. (km.)| ... | ~Endurance~ hrs.| ... | Number Built during 1912 | 2 | ----------------------------+--------------+ Remarks.--Experimental machines. [Illustration] ~D~ DUNNE. The Blair Atholl Aeroplane Syndicate, Ltd., 1, Queen Victoria Street, London, E.C. School: Eastchurch. In 1906 Lieut. Dunne was employed by the British Army authorities for secret aeroplane experiments. He had at that time patented a monoplane of < type. In 1907 _Dunne I_ was tried on the Duke of Atholl's estate in Scotland, but failed to fly, being smashed on the starting apparatus. _Dunne III_, a glider, 1908, was experimented with successfully by Lieut. Gibbs. In the same year _Dunne IV_, a larger power driven edition made hops of 50 yards or so. Early in 1910 the War Office abandoned the experiments. _Dunne II_, a triplane of 1906 design, was, by consent of the War Office, assigned to Prof. Huntingdon, who made one or two short flights with it at Eastchurch in 1910. At the same time the above syndicate was formed, and _Dunne V_, built by Short Bros., was completed in June, 1910. In 1912-13 the Huntingdon, modified, was flying well. [Illustration] -----------------------------+------------------+------------------+------------------+------------------ | 50 Gnome. | | | | ~1912-13~ | ~1912-13~ | ~1912-13~ | ~1912-13~ Model and Date. | single-seat | 2-seater | biplane. | biplane. | mono. | mono. | ~D 8.~ | ~D 9.~ | ~D 7.~ | ~D 7~ _bis._ | | -----------------------------+------------------+------------------+------------------+------------------ ~Length~ feet (m.)| _not given_ | ... | ... | ... ~Span~ feet (m.)| 35 (10.66) | 35 (10.66) | 46 (14) | 45 (13.70) ~Area~ sq. feet (m².)| 200 (18.5) | 200 (18.5) | 552 (51) | 448 (42) {total lbs. (kgs.)|1050 (476) | 1200 (544) | 1700 (771) | 1693 (768) ~Weight~ { | | | | {useful lbs. (kgs.)| 359 (161) | 528 (239) | 414 (187) | 509 (231) ~Motor~ h.p.| 50 Gnome | 70 Gnome | 60 Green | 80 Gnome ~Speed~ m.p.h. (km.)| 60 (95) | 60 (95) | 45 (70) | 50 (80) Number built during 1912 | 1 | 1 | 1 | 5 b'lding ('13) -----------------------------+------------------+------------------+------------------+------------------ Notes.--Biplane _D 3_ is identical with the original pattern _Dunne V_, except that it has only one propeller instead of two. It has been flown completely uncontrolled in a 20 m.p.h. wind, carrying a R. Ae. C. observer as passenger. [Illustration: DUNNE. Original Dunne biplane D5.] ~E~ EWEN. The W. H. Ewen Aviation Co., London Aerodrome: Hendon. Also works at Lanark, Scotland (opened February, 1913). Hold the British rights for and construct at their works _Caudron_ aeroplanes (see France). ~F~ FERGUSON. J. B. Ferguson, Ltd., Belfast. [Illustration] This machine first appeared in 1910. Owing to an accident to Mr. Ferguson it was laid up for a long time. About the end of 1912 it re-appeared. Principal details:-- ~Span.~--40 feet (12.20 m.) ~Area.~--230 sq. feet (21 m².) H.P. 40. ~G~ GRAHAME-WHITE. The Grahame-White Aviation Co., Ltd., 166 Piccadilly, London, W. Works and Flying Ground: Hendon. Founded by C. Grahame-White, the well-known aviator, who in 1909 commenced operations with a school at Pau. Later this was removed to England, and a general agency for the sale of aeroplanes, etc., established. This developed, and early in 1911 the firm was handling a special British agency for the U.S. _Burgess_ type known as "The Baby." The Hendon Aerodrome was acquired, and a factory established, which has grown continually ever since. In April, 1912, a monoplane to special design was completed. By the close of the same year biplanes of advanced design were constructed. Capacity of the works, March, 1913, was equal to 150 machines a year if necessary. ----------------------------------+--------------------+---------------+---------------+---------------+----------------- | ~1913.~ | ~1913.~ | ~1913.~ | ~1913.~ | ~1913.~ | Military | "Popular" | "Popular" | Tractor | Monoplane. | biplane. | biplane. | biplane. | hydro-biplane | Type IX. | Type VI. | Type VII. | Type VII. | Type VIII | single-seat. | 2-seater. | 1-seater. | 2-seater. | 2-seater. | | | | | | ----------------------------------+--------------------+---------------+---------------+---------------+----------------- ~Length~ feet (m.)| 33-1/4 (10.10) | 20-5/6 (6.40) | 26-5/6 (8.22) | 25 (7.60) | 21 (6.40) ~Span~ feet (m.)| 42 (12.80) | 29-1/6 (8.85) | 38 (11.60) | 42-1/2 (13) | 32 (9.75) ~Area~ sq. feet (m².)| 435 (40-1/2) | 230 (21) | 475 (44) | 380 (35) | 208 (19) {total lbs. (kgs.)| 2200 (997) | | | 850 (385) | ... ~Weight~ { | | ... | ... | | {useful lbs. (kgs.)| 750 (340) | | | 450 (204) | ... ~Motor~ | 120 Aust. Daimler | 50 Gnome | 50 Gnome | 80 Gnome | 50 Gnome {max. m.p.h (k.p.h.)| 70 (110) | 60 (95) | 50 (80) | 65 (105) | 65 (105) ~Speed~ { | | | | | {min. m.p.h (k.p.h.)| 55 (90) | 50 (80) | 40 (65) | 50 (80) | ... ~Endurance~ hrs.| 6 | 4 | 4 | 4 | 4 Number built during 1912 | 1 | ... | ... | 1 | ... ----------------------------------+--------------------+---------------+---------------+---------------+----------------- | Also built with a | Also built | | Also built | Also built with | 90 Aust. Daimler. | with a 35 | | with a 60 | a 35 Anzani. | | | | | | Designed to carry | | | | Two main floats | a gun on the bow. | | | | with 12-1/2 ft. track. | | | | | Floats are 15 ft. | Very good view. | | | | long, 2 ft. wide, | | | | | 1 ft. 3 in. deep. | Very strong landing| | | | | carriage. | | | | ----------------------------------+--------------------+---------------+---------------+---------------+----------------- [Illustration: Military Type VI. UAS.] [Illustration: "Popular" biplane. Type VII. UAS] [Illustration: Hydro-biplane. Type VIII. UAS.] ~H~ HOWARD-FLANDERS. L. Howard-Flanders, Ltd., 31, Townsend Terrace, Richmond, Surrey. School: Brooklands. Established February, 1912, by Howard-Flanders, whose connection with aviation dates from the pioneer days. Richmond Works opened April, 1912. Capacity of the works at end of 1912 was sufficient to turn out from 25 to 35 machines a year. -----------------------------+------------------+------------------+------------------+------------------+------------------ | ~F 4 1912.~ | ~B 2 1912.~ | ~S 2 1913.~ | ~F 5 1913.~ | ~B 3 1913.~ | 2-seater | 2-seater | single-seat | 2-seater | 2-seater | military | biplane. | monoplane. | monoplane. | biplane. | monoplane. | | | | -----------------------------+------------------+------------------+------------------+------------------+------------------ ~Length~ feet (m.)| 31-1/2 (9.50) | 31-1/2 (9.50) | 28 (8.50) | 31 (9.45) | 31 (9.45) ~Span~ feet (m.)| 40 (12) | 40 (12) | 35 (10.70) | 39 (11.90) | 40 (12) ~Area~ sq. feet (m²)| 240 (22) | 390 (36) | 190 (17-3/4) | 250 (23) | 390 (36) {total lbs. (kgs.)| 1850 (839) | 1500 (680) | 1180 (535) | 1600 (726) | 1650 (748) ~Weight~ { | | | | | {useful lbs. (kgs.)| 500 (227) | 450 (204) | 350 (159) | 600 (272) | 600 (272) ~Motor~ h.p.| 70 Renault | 40 A.B.C. | 80 Gnome | 80 Gnome | 80 Gnome {max m.p.h. (km.)| 67 (108) | 56 (90) | 82 (132) | 70 (115) | 68 (110) ~Speed~ { | | | | | {min m.p.h. (km.)| 41 (66) | 38 (61) | 45 (73) | 42 (68) | 40 (65) Number built during 1912 | 4 | 1 | | | -----------------------------+------------------+------------------+------------------+------------------+------------------ Remarks.--_F 4_ climbing speed 1000 feet (305 m.) in 3-1/2 minutes, 1500 in 5-1/2 mins., 2000 in 8 mins. _B 2_ climbing speed 200 feet (61 m.) per minute. The four _F 4_ type were bought by the British Army during 1912. [Illustration: Monoplane.] [Illustration: Biplane.] [Illustration: FLANDERS. UAS.] [Illustration: FLANDERS. UAS.] HANDLEY-PAGE Monoplanes. Handley Page, 72, Victoria Street, S.W. Works: 110, Cricklewood Lane, N.W. Flying ground: Hendon. Established at the end of 1908. In June, 1909, it was turned into a Limited Liability Co. Since then it has been busily employed in producing its own machines, also others to inventor's specifications. About the end of 1911 the firm bought up and sold all the machines of the Aeronautical Syndicate--_Valkyrie_ and _Viking_ types. It is doubtful whether any of these V type still exist--in any case it does not matter. Four were presented to the R. Flying Corps. Of these one was smashed up, the others, one army and two navy, were used to teach mechanics to take down and re-assemble engines, etc. Handley-Page also bought up the _Radley-Moorhouse_ machines (Bleriot copies), and disposed of them. The 1912-13 _Handley-Page_ type is as follows--a development along regular lines of the original H.P. machine:-- [Illustration: Handley-Page V.] ~Length,~ 27-1/2 feet (8.40 m.) ~span,~ 42-1/2 feet (12.95 m.) ~area,~ 240 sq. feet. (22-1/4 m².) ~Weight.~--Total, 1300 lbs. (590 kgs.) Empty, 800 lbs. (363 kgs.) ~Motor.~--50 h.p. Gnome. ~Speed.~ 55 m.p.h. (90 km.) Remarks.--The fixed tail area is 32 sq. feet. Body is entirely enclosed, stream line form. The passenger sits behind the pilot. Mounted on wheels and one long skid forward. Full description and details, _Flight_, 26th October, 1912. Principal pilots have been the late E. Petre (who made in it the only flight through London), the late Lieut. Parke, R.N., S. Pickles, and L. R. Whitehouse. The machine has been flown with two passengers, in addition to the pilot. ~Military work.~--During 1912 five biplanes of the _B.E._ type were ordered by the British War Office. Several monoplanes were ordered by foreign governments. [Illustration: HANDLEY PAGE. UAS.] ~L~ LAKE FLYING Co. Windermere. Established 1911, by E. W. Wakefield, with a view to hydro-aeroplane experiments. The first machine was a _Curtiss_ type built by A. V. Roe, which flew in November, 1911. In 1912, a special biplane generally of _Farman_ type but with more camber to the planes, was built. [Illustration: WATER HEN.] ~Length.~--36-1/2 feet (11 m.) ~Span.~--42 feet (12.80 m.) ~Area.~--270 sq. feet (25 m.²) ~Motor.~--Gnome. ~Speed.~--45.33 m.p.h. (72.54 k.p.h.) The single float is 6 feet wide, flexibly connected. Balancers mounted on a spring board. Water rudders for steering at slow speed. Fuller details see _Flight_, December 7th, 1912. Early in 1913, an _Avro_ was purchased for further experiments. ~M~ MARTINSYDE. Messrs. Martin & Handasyde, Brooklands, Weybridge, Surrey. Output capacity: about 20 per annum. ----------------------------------+-----------------+-----------------+ | ~1912.~ | ~1913.~ | Model and date. | Mono. 2-seater. | Mono. 2-seater. | ----------------------------------+-----------------+-----------------+ ~Length~ feet. (m.)| 35-1/2 (10.75) | 35 (10.65) | ~Span~ feet. (m.)| 42-1/2 (12.95) | 42-3/4 (13) | ~Area~ sq. feet (m².)| 290 (27) | 285 (26-1/2) | {total lbs. (kgs.)| ... | 1212 (550) | ~Weight~ { | | | {useful lbs. (kgs.)| ... | 551 (250) | ~Motor~ h.p.| 65 Antoinette | 80 Laviator | {max m.p.h. (km.)| 63 (102) | 78 (125) | ~Speed~ { | | | {min m.p.h. (km.)| ... | ... | Number built during 1912 | ... | ... | ----------------------------------+-----------------+-----------------+ Notes.--Wood construction. Landing: wheels and one skid. _Controls_: warping wings and rear elevator. Triangular body. The two models are very nearly identical. [Illustration: MARTIN-HANDASYDE. UAS.] ~P~ PIGGOTT. Piggott Bros. & Co., Ltd., 220, 222 & 224, Bishopsgate, London, E.C. This well-known firm of shed makers built a novel biplane in May, 1910 (details _Flight_, May 21st, 1910), and in 1911 a monoplane with enclosed body (_Flight_, April 1st, 1911). In 1912, both were disposed of, and the firm is not proceeding with its experiments. It has, however, a staff of skilled mechanics and a great deal of floor space for the construction of aeroplanes to specifications. PLANES. Planes, Ltd., 6, Lord Street, Liverpool. Works: Duke Street & Cleveland Street, Birkenhead. Not building at present. In October, 1910, the firm produced a biplane, designed by W. P. Thompson, fitted with a special pendulum stabilising device. This was followed a year or so later by a monoplane. ~R~ RADLEY-ENGLAND. This is not an aeroplane firm, but a special hydro built by two well-known aviators for the _Daily Mail_ competition. ~Length,~ 22 feet. ~Span,~ 50 feet. 2 floats, 15 feet long by 1 foot 5 inches wide. Pilot in starboard float. ~Weight,~ with petrol for 12 hours, 1,380 lbs. ~Motor,~ 150 h.p., made up of 3--50 h.p. Gnomes, but two Greens to be fitted for competition. One 4-bladed propeller in rear. ~Speed,~ 60 m.p.h., with 100 h.p. ~S~ SANDERS. This firm appears to have ceased to exist. SHORT BROS. Works and flying grounds: Eastchurch, Isle of Sheppey, Kent. London office: Queen's Circus, Battersea Park. Took up construction at a very early date. _Wright_ agents in 1909. Have built numerous biplanes and monoplanes to specifications. Produced their own first machine (see 1911 edition) in 1910. ----------------------------------+--------------------------------------------------+--------------------------------------------------+---------------------------------+-------------------------------------+-----------------+------------------ | ~S 41. 1913. Hydro Biplane.~ | ~S 45. 1913. Military Tractor~ | ~S 38. 1913.~ | ~S 34. Standard School.~ | ~1911-12.~ | ~1911-12.~ | | ~Biplane.~ | ~Military Nacelle Biplane.~ | | 1-seater, | Tandem +----------------+----------------+----------------|----------------+----------------+----------------+----------------+----------------+------------------+------------------+ mono. | tractor | 80 h.p. | 100 h.p. | 160 h.p. | 70 h.p. | 80 h.p. | 160 h.p. | 50 h.p. | 80 h.p. | 50 h.p. | 70 h.p. | | biplane. | 2-seater. | 2-seater. | 4-seater. | 2-seater. | 2-seater. | 4-seater. | 2-seater. | 3-seater. | 2-seater. | 2-seater. | | ----------------------------------+----------------+----------------+----------------|----------------+----------------+----------------+----------------+----------------+------------------+------------------+-----------------+------------------ ~Length~ feet (m.)| 35 (10.67) | 39 (11.90) | 45 (13.70) | 35-1/2 (10.80) | 35-1/2 (10.80) | 40 (13.70) | 35-1/2 (10.80) | 35-1/2 (10.80) | 42 (12.85) | 42 (12.85) | 25 (7.60) | 35-1/2 (10.80) ~Span~ feet (m.)| 40 (13.70) | 50 (15.25) | 50 (15.25) | 42 (12.90) | 45 (13.70) | 50 (15.25) | 52 (15.85) | 52 (15.85) | 46-1/2 (14.20) | 46-1/2 (14.20) | 29-1/2 (9) | 42 (12.90) ~Area~ sq. feet (m².)| 390 (36) | ... | ... | ... | ... | ... | ... | ... | ... | ... | 186 (17) | ... {Machine lbs. (kg.)| 1200 (545) | 1700 (764) | 2000 (909) |1080 (490) | 1100 (500) | 1890 (860) | 950 (432) | 1050 (480) | 1100 (500) | 1150 (523) | ... | 850 (385) ~Weight~ { | | | | | | | | | | | | {Useful lbs. (kg.)| 771 (350) | ... | ... | ... | ... | ... | ... | ... | ... | ... | ... | ... ~Motor~ h.p.| 80 Gnome | 100 Gnome | 160 Gnome | 70 Gnome | 80 Gnome | 160 Gnome | 50 Gnome | 80 Gnome | 50 Gnome | 70 Gnome | 50 Gnome. | 70 Gnome. {max (m.p.h.)| 65 (105) | 60 (97) | 74 (120) | 60 (97) | 70 (113) | 74 (120) | 42 (68) | 58 (94) | 39 (63) | 48 (78) | ... | 58 (94) ~Speed~ { | | | | | | | | | | | | {min (m.p.h.)| 50 (80) | 50 (80) | 56 (90) | 50 (80) | 50 (80) | 56 (90) | 35 (57) | 39 (63) | 34 (55) | 38 (61) | ... | ... ~Endurance~ hrs.| 4 | 5 | 6 | 5 | 5 | 6 | 4 | 5 | 4 | 5 | 5 | 5 Number built during 1912 | ... | ... | ... | ... | ... | ... | ... | ... | ... | ... | ... | ... | | | | | | | | | | | | ----------------------------------+----------------+----------------+----------------+----------------+----------------+----------------+---------------------------------+------------------+------------------+-----------------+------------------ Remarks.--Floats are two long pontoons. Subsidiary floats at tips of |Tandem seats, pilot in front. |Specially designed for |Solely designed for |No longer built, but still lower plane. Small tail float with water rudder. W.-t. compartments |Fittings for maps, etc. |reconnaissance. Tandem |school work. |in existence. to floats. Tandem seated, pilot in front. The observer's seat can | |seats, pilot in front. An |Seats side by side. | accommodate two if necessary. | |extra passenger can be | | | |accommodated. | | -------------------------------------------------------------------------------------+--------------------------------------------------+---------------------------------+-------------------------------------+------------------------------------ [Illustration: Old 1911-12 Tractor biplane.] [Illustration: Old 1911-12 mono.] [Illustration: Short. Hydro. "Short" Hydro-Aeroplane type s 41. 100 FP TRACTOR BI-PLANE UAS.] [Illustration: Short. S. 45 type. UAS.] [Illustration: Short. S. 38 military. UAS.] SOPWITH. Sopwith Aviation Co. Works: Canbury Park Road, Kingston-on-Thames. School: at Brooklands. Established by T. O. M. Sopwith, the well known aviator at Brooklands, Autumn of 1911, where during 1912, a 70 h.p. tractor biplane and a 40 h.p. biplane was turned out. Floor area of the Kingston works in March, 1913, was 30,000 sq. feet with electric power plant. Works manager: F. Sigrist. General manager: R. O. Cary. Output capacity: at full pressure about 50 machines a year. ----------------------------------+-------------------+-------------------+-------------------+------------------- | ~1913.~ | ~1913.~ | ~1913.~ | ~1913.~ Model and Date. | Bat boat | Tractor | School | Armoured | hydro | biplane | biplane. | warplane. | biplane. | 3-seater. | | ----------------------------------+-------------------+-------------------+-------------------+------------------- ~Length~ feet (m.)| 30-1/3 (9.20) | 29 (8.85) | 29 (8.85) | 29' 7-1/2" (9) ~Span~ feet (m.)| 41 (12.50) | 40 (12.20) | 40 (12.20) | 50 (15.25) ~Area~ sq. feet (m².)| 422 (39) | 365 (34) | 400 (37) | 552 (51) {total lbs. (kgs.)| 1700 (771) | 1750 (794) | 1200 (544) | 2000 (907) ~Weight~ { | | | | {useful lbs. (kgs.)| 500 (227) | 750 (340) | 400 (181) | 800 (362) ~Motor~ h.p.| 90 Austro-Daimler | 80 Gnome | 50 Gnome | 90 Austro-Daimler {max. m.p.h. (km.)| 65 (105) | 74 (125) | 48 (78) | 65 (105) ~Speed~ { | | | | {min. m.p.h. (km.)| 42 (68) | 40 (65) | 35 (60) | 38 (61) ~Endurance~ hrs.| ... | ... | ... | ... ----------------------------------+-------------------+-------------------+-------------------+------------------- Notes.--Wood construction. Carriage wheels and skids. _Control:_ balanced ailerons. [Illustration: Sopwith. Flying boat.] [Illustration: 1913. Tractor biplane.] ~V~ VICKERS. Vickers, Ltd., Vickers House, Broadway, Westminster. School: Brooklands. Seven pupils qualified during 1912. -----------------------------------+-----------------+------------------+ | Monoplane. | Military | Model and date. | ~1912-13.~ | biplane. | | 2-seater. | ~1913.~ | -----------------------------------+-----------------+------------------+ ~Length~ feet (m.)| 25 (7.60) | ... | ~Span~ feet (m.)| 34-1/2 (10.50) | 40 (12.20) | ~Area~ sq. feet (m².)| 220 (20) | 385 (35) | {total, lbs. (kgs.)| 730 (331) | ... | ~Weight~ { | | | {useful, lbs. (kgs.)| ... | ... | ~Motor~ h.p.| 80 Gnome | 80 Wolseley | ~Speed~ m.p.h. (km.)| 70 (115) | ... | ~Endurance~ hrs.| 3 | ... | Number built during 1912 | ... | ... | -----------------------------------+-----------------+------------------+ Notes.--Steel construction. Landing shock absorbing: 2 wheels and 1 skid. Rectangular enclosed body. _Controls_: warping and rear elevator. ~Monoplane~ climbs 300 feet a minute fully loaded. ~Biplane~ is armed with a Vickers R.C. automatic gun in the bow. [Illustration: VICKERS. UAS.] [Illustration: Vickers. Monoplane.] +------------------------------+ | | | | | | +------------------------------+ Vickers. Armed biplane. ~W~ WHITE. J. Samuel White & Co., Ltd., shipbuilders and engineers, East Cowes, Isle of Wight. London office: 28, Victoria Street, S.W. This well-known firm of torpedo craft builders, etc., formally opened an aviation department on 1st January, 1913, with Howard T. Wright as general manager and designer. ----------------------------------+----------------+ | ~1913.~ | | Navy 'plane. | ----------------------------------+----------------+ ~Length~ feet (m.)| 30 (9.15) | ~Span~ feet (m.)| 44 (13.40) | ~Area~ sq. feet (m².)| 500 (46-1/2) | {total lbs. (kgs.)| 2000 (907) | ~Weight~ { | | {useful lbs. (kgs.)| 650 (295) | ~Motor~ h.p.| 160 Gnome | {max. m.p.h. (km.)| 70 (115) | ~Speed~ { | | {min. m.p.h. (km.)| 35 (57) | Number built | ... | ----------------------------------+----------------+ Remarks.--Hydro-biplane, with Howard T. Wright patent aeroplanes to give wide range of speed. Two patent hydro floats, 21 feet (m.) long, three steps on each. [Illustration: UAS.] BRITISH DIRIGIBLES. ~Navy.~ ~Army.~ /-------------------------^----------------------------------\ /------------------^--------------------\ --------------------------------+----------------+---------------------+-----------------------+-------------------+--------------------- | | | | | ~III, & IV & V~ Name and date. | ~II Willows 3.~|~III Astra Torres 2.~| ~IV Parseval 18.~ | ~II BETA.~ | ~GAMMA, DELTA,~ | ~1911.~ | ~1913.~ | ~1913.~ | ~1909 (1910.)~ | ~EPSILON.~ | | | | | ~1910, 1912, 1913.~ --------------------------------+----------------+---------------------+-----------------------+-------------------+--------------------- ~Volume~ c. feet (m³.)| 31,800 (900) | 222,500 (6,500) | 311,000 (8,800) | 21,000 (594) | 70,600 (2,000) ~Length~ feet (m.)| 120 (36.50) | ... | 276 (84) | 104 (31.70) | 152 (46) ~Diameter~ feet (m.)| 40 (12.20) | ... | 49-1/4 (15) | 25 (7.60) | 30 (9.10) {fabric | Spencer | Continental | Metzler | Gold beater skin | Continental ~Gasbags~ {compartments | _nil_ | 3 | _nil_ | _nil_ | _nil_ {ballonets | 1 | 1 | 2 | 1 | 2 {total tons| about 1/2 | about 7 | about 10 | _about_ 3/4 | 2-1/5 ~Lift~ { | | | | | {useful, tons| ... | ... | ... | ... | ... ~Motors~ h.p.| 30 (=30) | 2--120 Chenu (=240) | 2--180 Maybach (=360) | 1--30 Green (=30) | 2--50 Green (=100) {number | 2 (swivel) | 2 | 2 (s.r.) steel | 1 | 2 (swivel) ~Propellers~ {blades | 2 | 2 | 4 | 2 | 2 {diameter feet (m.)| ... | ... | ... | 6 (1.82) | 8-5/6 ~Speed~ max. m.p.h. (km.)| ... | 38 (63) | 42 (68) | 18 (29) | 28 (45) ~Endurance~ full speed| ... | ... | ... | ... | 4 hours ~Max. complement~ | 2 | 15-18 | 10-12 | 3 | 5 ~Station~ | Farnborough | ... | ... | Farnborough | Farnborough --------------------------------+----------------+---------------------+-----------------------+-------------------+--------------------- Notes.--All the above are non-rigid. The military ones were all built at the Royal Aircraft Factory. ~Navy Dirigible Pilots.~ Boothby, Lieut. F. L. M. (_F.C._) Everett, Gunner F. Masterman, Comdr. E. A. D. (in command) Usborne, Lieut. N. F. (squad comdr.) Woodcock, Lieut. H. (_F.C._) Undergoing Naval Aircraft Course: Crocker, Lieut. W. R. Hicks, Lieut. W. C. Wilson, Lieut. R. A. ~Military Dirigible Pilots.~ ~Squadron Commanders.~ Maitland, Capt. E. M. ~Flight Commanders.~ Waterlow, Lieut. C. M. ~Flying Officers.~ Brabazon, Capt. Honble. C. M. P. Fletcher, Lieut. J. N. (R.E.) Hetherington, Lieut. T. G. Mackworth, Lieut. J. D. Pigot, Capt. R. The following hold dirigible pilot certificates, but are not at present employed:-- Broke Smith, Capt. P. Capper, Col. J. E. Fox, Lieut. A. G. ~Private Dirigibles.~ There are one _Willows_ (1912) (sister to the naval one) and a couple of _Spencers_ about the size of _Beta_. ~Private Dirigible Pilots.~ Willows, E. T. (24-32, Villa Rd. Handsworth, Birmingham). ~BRITISH NAVAL DIRIGIBLES.~ [Illustration: Willows. The naval one is fitted with a boat-shaped car.] [Illustration: Parseval. (photo of a sister ship.)] +-------------------------------------------------------------------+ | | | ~New Construction.~ | | | | Messrs. Vickers have acquired the Parseval rights for the British | | Empire, and several airships of this type are likely to be put in | | hand by them shortly. | | | | Also reported that a big rigid is projected. | | | +-------------------------------------------------------------------+ ~BRITISH MILITARY DIRIGIBLES.~ [Illustration: Beta.] [Illustration: BETA.] [Illustration: Gamma (Delta the same, but a smaller and enclosed car).] [Illustration: GAMMA.] BRITISH COLONIAL AIRCRAFT. ~AUSTRALIAN.~ ~Military Aviation.~ In January, 1913, the Australian Flying Corps was instituted, as a part of the citizen forces. During 1913, about £5,600 is to be spent. The force is to consist ultimately of 4 officers, 7 warrant officers and sergeants, 32 mechanics. The school is at Duntroon. Course includes--mechanics of the aeroplane, aerial motors, meteorology, aerial navigation by compass, aerial photography, signalling, etc. Mr. Harrison is in command with Lieut. H. Petre as assistant. ~Australian Aviators.~ Banks, R. C. Busteed, H. Duigan, J. R. Hammond, J. J. Harrison +Hart +Lindsay, C. Petre, H. Pickles Watts +=killed. ~Private Aeroplanes.~ J. R. Duigan has built an aeroplane of his own design. ~NEW ZEALAND.~ Nothing doing worth mention. One _Bleriot,_ 80 h.p., presented 1913 by the _Standard,_ London. ~CANADIAN.~ ~Aerial Societies.~ Aeronautical Society of Canada, c/o. M. P. Logan, 99 Gloucester Street, Toronto McGill Aviation Club, McGill University, Montreal Oshawa, Ontario Ae. C. Note.--Owing to the fact that the late Aerial Experiment Association was half Canadian and half U.S.A., it is difficult to draw a very clear dividing line between Canadian and U.S. aviators or machines. Thus, one given here is partly U.S.A., while at least one U.S. machine may be claimed as "partially Canadian." ~AVIATORS.--Private.~ Bell, Dr. Graham McCurdy, J. A. D. (U.S.A. Ae. C. 18) McHardy Symonds, E. F. St. Henry R. ~Canadian Aeroplanes.~ GRAHAM-BELL II. Flights were made by Dr. Graham-Bell in a tetrahedal type, similar to one described in the 1911 edition. McCURDY-WILLARD. Biplane. ~Maximum length,~ 26-1/4 feet (8 m.) ~maximum breadth,~ 31-1/3 feet (9.50 m.) ~supporting surface,~ ? sq. feet (? m².) ~Total weight.~-- ~Body.~--Central skid in combination with 4 wheels. Triangular body, base of triangle on top. Fuselage entirely enclosed. ~Planes.~--Maximum span, 31-1/3 feet (9.50 m.) Chord, 3-1/2 feet (1 m.) Gap, 5 feet (1.50 m.) Ailerons at trailing edge of wing tips, 6 feet x 2 feet (1.80×0.60 m.) ~Motor.~-- ~Speed.~-- ~Tractor.~--Diameter, 7-3/4 feet (2.40 m.) Pitch, 6 feet (1.82 m.) ~Steering.~--Double elevator placed in rear of tail. _Control_, push and pull wheel. Rudder in rear. _Control_, wheel. Ailerons. _Control_, turning steering-wheel left or right. Remarks.--See _Aeronautics_, U.S.A., August, 1911. There has been also the _Baddeck_ and other early machines (see 1911 edition), but none of them seem to be in existence at the present time. ~INDIAN.~ ~Military Aviation.~--A certain number of officers belonging to the Indian Army have qualified as pilots when home on leave, but there is no organised force. One is, however, proposed. ~Private Aviation.~--In the past two or three home-made machines appeared, and one or two were imported, but most or all are now extinct. ~SOUTH AFRICA.~ ~Military Aviation.~--Non-existent. ~Private Aviation.~--J. Weston is a qualified pilot, but at the outside there are not more than two effective machines in the country. BULGARIAN. In the Balkan War, 1912-13, Bulgaria hastily organised an aviation corps. This, though necessarily lacking in military organisation, proved very useful on several occasions. At the end of March, 1913, the aeroplanes effective included 6 _Bristol_ monos.; one 70 h.p. _Bleriot XXI_; 2 _Bleriot XI bis_ (captured from the Turks); also some half-dozen or more miscellaneous machines temporarily hired. ~Military Aviators.~--The principal are Lieuts. Milkoff, Taraxchieff and Petroff. A number of other officers in various stages of training. CENTRAL AMERICAN. ~General Note.~--Nicaragua and S. Domingo have both purchased one or two aeroplanes for their military forces: but nothing appears to have been done with them. CHILIAN. ~Aviator.~--Edwards, Emilio. Sanchez Besa is a Chilian, but resides in Paris (see France). ~Military Aviation.~--In 1912, a commencement was made and one 80 h.p. _Deperdussin_ purchased. Other machines are now on order. CHINESE. ~AVIATORS.~ Lee, Y. L. (British Ae.C. 148) Tsai Tao Prince ~Military Aviation.~ In March, 1913, orders were placed for six 80 h.p. _Caudrons_, also for six 50 h.p., and a decision arrived at gradually to acquire a force of 700 aeroplanes, but very little has actually been done to date. DANISH. ~Aerial Societies~:-- Danske Aeronautiske Selskab, 34 Amaliegade, Copenhagen. ~Aerial Journals~:-- None; but Motor (3 Bredgade, Mezz, Copenhagen) deals with aerial matters. ~Flying Grounds~:-- Klampenburg, Copenhagen. Skandinarisk Aërodrom. ~Army Aeroplanes.~ In 1911 there was an Antoinette. Nothing done since. ~AVIATORS.~ Military. Ullitkz, Kapt. Private. Arntzen, Dr. Christiansen, S. Ellerhammer Folmes, Hansen Maltke, Count Nervoe, A. Svendsen, R. Thorup, K. DUTCH. (Revised by I. SCHIERE, Aeronautical Engineer and Librarian of the Dutch Ae. C.) ~Aerial Societies:--~ Haagsche Proefvliegtuig Club (3e V.d. Boschstreet 20, The Hague). Nederlandsche Vereeniging voor Luchtvaart (Nassau Zuilensteintraat, 10, The Hague). (Ae. C.) Rotterdamsche Model Aero Club (Rochussenstreet 229b, Rotterdam). _Colonial:_ Nederlandsche Indische Vereeniging voor Luchtvaart. ~Aerial Journals:--~ _De Luchtvaart_ (Ged Onde-Gracht, 141, Haarlem). Fortnightly. _Avia_, Wynbrugstraat 13, Rotterdam. Fortnightly. ~Flying Grounds:--~ ~Breda-Gilske-Rijen.~--6 hangars. ~Soesterberg.~--20 hangars. ~Army Aeroplanes.~ Up to the end of 1911 there were none, though some officers had their own private ones (_H. Farman's_ mostly). At end of 1912. 2 monos. _Deperdussin_ (for Java). 1 biplane. _De Brouchére_ (for Java). ~AVIATORS.~ (The number against any name is, unless otherwise stated the Ae. C. Nederlandsche pilot certificate number.) To end of ~1911~. Military. Bakker, H. Yandrig Labouchere, Lieut. J. Meel, Lieut. Van Poorton, Lieut. H. ter Versreegh, Lt, W. C. J. Private. Bahle, F. K. Boerlage, M. Burgh, Van der Fokker, A. H. G. Hilgers, J. W. E. L. Konings, L. Koolhoven (1) Küller, G. P. (2) Lutge, F. (4) (323, F.) Mulder, A. Riemsdyk, Van F. (5) Ryk, Madame Bde. Wynmalen, H. (6) (208, F.) The following Dutch aviator has been killed: +------------------+ | 1911. | | Van Maasdyck, C. | | (130, Ae. C. F.) | +------------------+ DUTCH AEROPLANES. DE BROUCKERE. Biplane. _H. Farman_ type. Details, _De Luchtvaart_, No. 8, 1911. FOKKER. Monoplane. Anthony Fokker, of Haarlem. In early 1912 flew at Breda. MONNIER-HARPER. Monoplane. (O.P.I.I.) Generally _Bleriot_ type. Built 1911. VAN DEN BURG. Monoplane. Early in 1912 was flying at Johannisthal, Germany. VREEDENBURGH. Monoplane. (O.P.I.I.) Blend of _Bleriot_ and _Antoinette_. Motor, 75 h.p. Miesse. Completed December, 1909. [Illustration] FOKKER. Monoplane. (See Germany for details.) Firm now established in Germany. DUTCH DIRIGIBLES. ~Military.~ DUINDIGT. Non-rigid. (Zodiac make.) ~Length~, 111-1/2 feet (34 m.) ~diameter~, 22-1/2 feet (60.80 m.) ~capacity~, 31,785 c. feet (900 m³.) ~Motor~.--18 h.p. Remarks.--Small edition of _Zodiac III_. (See France.) FRENCH. (Special French Editor.) ~Aerial Societies:--~ Aero Club de France. Academie Aeronautique de France. Aeronautique Club de France. Société des Aëronautes du Siège. Aero Club du Sud Ouest. Aero Club du Rhone. Aero Club du Nord. La Ligue Aerienne du Sud. Société Francaise de Navigation Aérienne. Société d'encouragement à l'Aviation. (_Full list of clubs next page._) ~Aerial Journals:--~ _L'Aerophile._ _L'Aero._ _L'Aeronaute._ _Aerostat (Bulletin Aeronautique)._ _Aerostat (Academie d'Aerostation)._ _Revue de l'Aerostation._ _Le Ballon._ _L'Aerostation._ _L'Aeronautique._ _Bulletin Aeronautique._ _Encyclopediede l'Aviation._ _La Ligue Nationale Aerienne._ _Revue de l'Aviation._ _L'Aeromécanique._ ~Principal Flying Grounds:~ ~Antibes.~--Hanriot school. ~Beauce.~ ~Betheny.~--Sommer school. ~Deperdussin School.~ ~Buc.~--M. Farman school. ~Buoy.~ ~Chalons.~--Sommer school. ~Chalais-Mendon.~ (Military) ~Chatres.~--Savary school. ~Cran~, Marseilles. ~Crotoy.~--Caudron school. ~Croix d'Hins~, Bordeaux (Aer. Lig. du Sud.) Area 6 km. Track. Free sheds. ~Corbeaulieu~ pres. Compregne.--Doutre school. ~Etampes.~--Bleriot school. Farman school. ~Grand Camp, Lyons.~ ~Issy les Moulineaux.~--Astra school ~Juan-le-Pias.~--Paulhan aquaplane school. ~Juvissy~, near Paris.--Aerodrome. Caudron school. Goupy school. ~La Brayelle~, Douai.--Breguet school. ~Da motte Brueil dans L'Oise.~ ~Le Bourget~, Paris.--100 sheds. ~Le Mans.~ ~Moisson.~ ~Mourmelon.~--Voisin school. ~Napante.~ ~Nice.~--Small and rough surface. ~Pau.~--Bleriot school. ~Reims.~--Aerodrome. ~St. Cyr.~ ~Villacoublay~, Paris.--Breguet, Nieuport and Astra schools. FRENCH AEROPLANES. ~Military Aviation.~ In February, 1912, the then total of 208 effective aeroplanes were divided into "squadrillas" consisting of eight aeroplanes; attached to these eleven or twelve motor cars, one traction car and one fast car, also a repairing car and repairing van. It was then estimated that at the end of 1912, ~344~ aeroplanes would be available for service. The estimated _personnel_ was provisionally fixed at 234 officer pilots, 210 scouts, 42 mechanics, 110 officers, 1,600 corporals or sappers and 550 privates. Approximately £880,000 was spent in aviation during 1912, and £1,000,000 was estimated for future years. The French military aviation centres are all upon somewhat the same footing as fortresses, and the greater part of the work comes under the head of "confidential." The principal school is at St. Cyr, which was specially selected because the ground is rough and mostly covered with small shrubs: it being held important to train officers from the first to rise and land on ground similar to that most likely to be found in war time. Each station is supplied with large portable wooden-framed hangars covered with canvas. These can be rapidly taken to pieces and re-erected. Each station is supplied with its own special motor transport. All military machines are provided with a compass and map case in front of the pilot and sketching apparatus in front of the observer. Although a few non-commissioned officers have been taught flying, the organization only contemplates the employment of commissioned officers as pilots. The age limit is 38. On April 16th, 1913, the flying corps was modified. The principal features of the corps as now existing are as follows:-- ~Establishments.~ 1. Schools. 2. Special establishments, dealing with purchase, construction, and big repairs. 3. _Directions._ Administration of _material_. 4. Depots. A species of dockyards dealing with minor repairs, etc. ~Administration.~ There are three main groups, each commanded by a colonel. Each group consists of dirigibles and aeroplane "escadrilles," and is fully equipped with establishments, etc. The three centres are:-- 1. Versailles. 2. Reims. 3. Lyon. ~General.~ All squadron units are made up of machines of the same make and power. Pilots are detailed as required to any particular unit, and liable to transfer from one to another, though in practice such transfers are rare. ~Army Aeroplanes.~ During 1912 nearly 500 machines were delivered to the Army, but a great many old machines have been scrapped. At the end of March, 1913, the force stood at 421 effective for war machines, plus an uncertain number of school machines and obsoletes. About one-third or more of the effective aeroplanes were _Farmans_. The rest consisted of all leading French types, proportionated more or less to the productive capacity of these firms. Also certain other makes experimental. ~Navy Aviation.~ The Navy section of French military aviation is still in the "being formed" process. No data are yet available as to the ultimate force to be provided. At present the number of effective war machines is small. It is made up of hydro-avions of the following types:--_Astra_, _Borel_, _Breguet_, _Caudron_, _Deperdussin_, _Donnet-Leveque_, _Farman_, _Paulhan-Curtiss_, _Sanchez-Besa_, the total at end of March, 1913, being well under 20. There are also two special _Bleriot_ type fitted with floats, which carry 330 lbs of explosive, are fitted with wireless, have a speed of 140 km.p.h. (85 m.p.h.), and a radius of about 600 miles (1,000 km.) ~PRINCIPAL FRENCH ARMY AND NAVY AVIATORS.~ (In each case the number against each name is, unless otherwise stated, the Ae. C. French certificate pilot number.) Army. Abadie, Sous Officier Acevedo, Lieut. (740) Acquaviva, Lieut. Paul V. (68) Aiguillon, Lt. R.d' (308) Aubry, Lieut. Balensi, Capt. Albert (173) Bares, Capt. (543) Basset, Lieut. Paul (145) Battini, Lieut. G. (508) Baugnies, Lt. J. B. E. (193) Beatrix, Sous Officier Bellemois, Lieut. G. (546) Bellenger, Capt. M. (45) Berni, Lieut. (760) Biard, Capt. G. M. (261) Bihan, Lieut. Binda, Lieut. Louis (232) Blard, Lieut. (460) Bobillier, Lieut. Boerner, Lieut. Boissonas, Lieut. (443) Bon, Lieut. Boncour, Lieut. (478) Bonnier, Lieut. (478) Bonnier, General (137) Boucher, Lieut. Bousnuet, Lieut. P. (295) Breley, Lieut. Brenot, Capt. Brouchard, Lieut. Brugiere, Lt. Brule, Lieut. (436) Bruncher, Lieut. Burgeat, Capt. M. (44) Camerman, Lieut. F. (33) Camine, Capt. Campagne, Lieut. (782) Casse, Capt. (415) Chabert, Lieut. Charoux, Sous Officier Chavenac, Lieut. E. (551) Cheutin, Lt. E. J. (233) Chevreau, Lieut. R. (132) Clavenad, Lieut. P. (294) Clerc, Lieut. (465) Clolus, Commdt. G. (97) Couret, Lieut. Coville, Capt. D'Abrantes, Lieut. D'Aquillon, Lieut. De Beruis, Lieut. De Caumont, Capt. De Chanac Lanzac, Capt. De Geyer, Lieut. De Gorge, Lieut. (805) De Goys, Capt. De Lafargue (417) De L'Estrade, Lieut. De Rose, Lieut. P. (477) Destace, Capt. Destouches, Capt. Devarenne, Lieut. Devaulx, Lieut. R. (158) De Ville d'Avray, Lieut. Didier, Sous Officier (765) Do-Ird, Lieut. Drevet, Sous Officier (753) Duparquet, Capt. Duperron, Capt. (196) Dupin, Lieut. Eteve, Capt. A. (89) Erstorac, Capt. Felix, Capt. J. (270) Fequant, Lieut. A. (63) Fequant, Lieut. P. (340) Fierstein, Sous Officier Francezon, E. (410) Foirelline, Lieut. Garnier, Lieut. (305) Garnier, Lt. (826) Gastringer, Lieut. Gaubert, Lieut. E. (313) Germain, Lieut. Girard, Lieut. J. (197) Gironde, Lt. A. de Godefroy, Sous Officier (583) Gouin, Lt. M. E. R. (348) Gourlez, Lieut. (521) Grezaud, S.-Lt. P. (265) Grailly, Lieut. (399) Gronier, Lieut. J. (138) Grandjean, Sapper Guibart, Lieut. Guiton, Sous Officier Hable, Sous-Lt. A. L. (257) Hugoni, Capt. E. (165) Hanouille, Lieut. Henequin, Lieut. Henri, Lieut. (497) Herli, S.-Lt. (257) Hurard, Sous Officier Issartier (531) Jacquet, Lieut. Joly, Lieut. F. (341) Jost, Lieut. R. G. (264) Kass, Capt. Langardt, Lieut. Laurent, Sous Officier (246) Le Beau, Capt. Le Bleu, Lieut. Lelievre, Lieut. E. (522) Lemasson, Lieut. (506) Le Mauget, Capt. Letheux, Lieut. G. (142) Letort, Sapper (170) Letourneur, Lieut. Lucca, Lieut. D. (154) Ludmann, Lieut. G. (255) Lussigny, Lieut. Machin, Lieut. Mailfert, Lieut. F. (146) Maillois, Lieut. J. (131) Malherbe, Lt. de (334) Maneyrol, Lieut. Manoha, Lt. Marc, Lt. Marconnet, Capt. (90) Marie, Capt. Felix (80) Marlin, Lieut. Marmies, Lieut. Marty, Sous Officier (816) Massol, Lieut. Mauger, Lieut. Maurice, Lieut. Mazac, Lieut. (592) Migaud, Lieut. G. (501) Morel, Sous-Lt. P. (262) Morlaye, Lieut. la Mouchard, Lieut. Negre, Capt. Nicaud, Lieut. Nogues, Capt. (114) Normand, Lieut. F. (314) Pelloux, Sous-Lt. M. (346) Peraldi, Lieut. Peretti, Sous Officier Pierre, Lieut. Ponchet, Lieut. Prat, Lieut. Precardin, Lieut. Princetau, Lieut. Postulat, Sergt. Quennehen, Sous Officier Ragot, Lieut. Remy, Lieut. H. C. (143) Reynard, Lieut. (668) Rimbert, Lieut. Rocca-Serra, Lieut. Rochette, Lieut. J. (564) Rolland, Lieut. M. E. (545) Ronin, Lieut. Rougerie, Lieut. Sauleillon, Lt. A. (674) Saunier, Lieut. G. (153) Seguin, Sapper (528) Sevelle, Lieut. (747) Silvestre, Lieut. (599) Sido, Capt. Marie (65) Sourdeau, Lieut. A. (474) Soulielani, Lieut. Thomas, Lieut. (846) Thomas, R. (116) Touzet, E. (485) Tretane, Lieut. Tricornot de Rose, Lt. de (330) Vandamone, Lieut. (535) Van de Vaero, Lt. (491) Vandine, Lieut. Varcin, Lieut. Vaudein, Lieut. Verdier, Sous Officier (538) Vibra, Lieut. Vigne, Lt. Henri (315) Vinda, Lieut. Vitra-Rougerie, Lieut. Vocayeau, Lieut. Vogoya, Capt. Vuilliereme, Lt. L. (174) Watteau, Lieut. Willemenz, Lieut. (759) Yence, Lieut. R, (220) Naval. Byasson, Lt. de V. (175) Cayla, Lieut. (458) Conneau, Lieut. (322) "Beaumont" Davelny, Comdt. Delage, Lieut. G. (219) Fournier, Lieut. Hautefille, Lieut. (247) Lafon, Lt. (194) Leve, Lieut. (243) Parasa, Lieut. (179) Reymond, Lieut. (206) ~FRENCH AEROPLANES--PRIVATE.~ ~Private Aeroplanes.~ The total number of machines built in France during 1912 has been estimated at about 1,500. This includes military as well as private machines, also machines exported, and appears to be unduly generous even so. The actual total of machines commenced and completed in 1912 is nearer 1,000. The number of private aeroplanes--excluding demonstration and school machines is small. ~PRIVATE AVIATORS~ (brevets to end of 1911). (In each case the number against each name is, unless otherwise stated, the Ae. C. French certificate pilot number.) Algrin, Rene (252) Allard, M. (480) Alincourt (488) Andre, C. (192) Aubrun (21) Bachot, A. (271) Baeder, F. de (107) Bague, E. (337) Balliod, Louis (236) Balaye, A. (275) Balsan, Jacques (22) Baratoux, Marcel (49) Barbotte, Ernest (268) Barra, Franck (171) Barrier, A. (64) Banier, Rene (64) Bathiat, Georges (237) Bathiat, Leon (110) Beard, Pierre (276) Beaud, Edouard (150) Becue, Jean F. (263) Bellier, Albert (297) Bellot, Andre (317) Benoist, Jean (369) Bergognie, Charles (373) Bernard, A. (505) Berlot, Henri J. (450) Biard, Desire J. (460) Bielovucic, Jean (87) Bill, Henri (205) Blanchet, Georges (244) Bleriot, Louis (1) Blondeau, Gustave (101) Bobba, Andre (309) Boillot, Geo. (395) Boissounas, L. (443) Boise de Courcenay, Comte (283) Boivin, Albert (248) Bonzon, Maurice (355) Bouvier, Andre (120) Boyer, Louis (303) Bregi, Henry (26) Breguet, Louis (52) Bresson, Georges (280) Briancon, Lucien (277) Briey, F. de (492) Brindejonc des Moulinais (449) Bruneau de Laborie, E. (67) Bunau-Varilla, E. (16) Busson, Guillaume (121) Caille, Albert (200) Caramanlaki, A. (761) Carles, Fernand (362) Carlin, L. V. (554) Caudron, Rene (180) Cayla, P. (458) Chailliey, Henri (63) Challe, M. J. (523) Champel, Florentin (94) Chanteloup, P. (549) Chapelle, J. (547) Charpentier, Louis (286) Chassagne, Jean (160) Chausse, P. (519) Chaussier, Piere (384) Chatain, Marius L. (267) Chatain, L. M. L. (296) Chateau, Edouard (135) Chaunac-Lenzac de (394) Chemet, Geo. (159) Cheuret, Leon (62) Cherent, L. (62) Chevalier, J. (515) Chevalier, Louis (333) Chevillard, Maurice (385) Chioni, Basile (250) Clerc, Paul A. L. (465) Clement, M. (108) Collardeau, Geo. (393) Collieux, M. (85) Collin, Georges (279) Conard (647) Contard, Paul (351) Contenet, Henri (447) Contour, Ernest (371) Contre (657) Cordonnier, Robert (221) Corso, E. (529) Crochon, Andre (43) Cronier, Andre M. H. (352) Cugnet, Gaston (140) Cure, Gaston M. (242) Daillens, Jean (119) Dancourt, P. H. (520) Debener, M. (562) Deletang, Fernand (42) Delacroix, Maurice (452) Delagrange, Robert (366) De La Roche, Mde. (36) Deloche, R. D. (526) Denis, Auguste (380) Deroy, Francis (374) Derry, Leon (254) Deruissy, Andre (376) Despres, E. M. L. (527) Deschamps de Bois, Hébert (461) Didier, A. (77) Divetain, Pierre (466) Driancourt, M. L. (525) Dubonnet, Emile (47) Ducoweneau (456) Dufour, Jean M. R. (457) Dufour, Jean (96) Dufour, Louis (185) Duval, E. (118) Duval, Emile (118) Echeman, P. M. (466) Esnault-Pelterie, R. (4) Espanet, Dr. G. (532) Farman, Henry (5) Farman, Maurice (6) Fiorellimo, Louis (369) Florencie, Jean (201) Fournie, J. P. S. (502) Frantz, Joseph (363) Francq, Baron de (481) Frey, Alfred (48) Frey, Andre (93) Froussart, Ernest (350) Frugier, Leon (378) Gaget, Joseph (335) Gaillard, J. O. C. (504) Gallie, Fernand (343) Gardey, M. (482) Garros, Roland (147) Garsonnin, L. (555) Gastinger, Edouard M. (455) Gassnier, René (39) Gassier, Marcel (392) Gasnier, Pierre (391) Gaudart, Louis (228) Gaulard, Charles (302) Gautheron, Louis (449) Gaye, Georges (251) Gibert, Louis (92) Gilbert, Eugene (240) Giraud, Etienne (493) Glorieux, Leon (188) Gobe, Armand (102) Gobron, Jean (7) Goffin, Marcel (284) Gouguenheim, P. (388) Goux, Jules (398) Gournay, Henri (186) Goys de Mereyrac, Louis (354) Grandjean, E. C. H. (469) Grandseigne, R. (360) Granel, Marcel (117) Grellet, Alexis (370) Gressard, M. (725) Gue, Albert (216) Guerre, Henri (444) Guidard, V. P. (487) Guilband, C. J. (518) Guillemard, T. (445) Guillaume, C. (651) Hainaux, Marcel R. (239) Hanriot, Marcel R. (239) Hanriot, Rene (368) Herbster, Maurice (41) Herveu, Mlle. Jane (318) Hesne, Paul (113) Houlette, Andre (367) Jacquemart, G. C. (464) Jamblez, Paul A. (266) Janoir, L. (553) Joliot, André (202) Joly, C. E. M. (530) Julleriot, Henry (61) Junod, Auguste (253) Kauffman, Paul (198) Kergariou, Engard de (503) Kieffer, C. E. (372) Kummerling, A. (291) Koechlin, Jean P. (203) Kuhling, Paul L. (136) Labouchere, Rene (86) Labouret, Rene (222) Lacombe, P. (534) Ladougne, Emile (81) Lafarge, Henri (278) Lajous, Francois, A. (463) Lambert, Comte de (8) Langhe, Armand de (204) Lastours, H. R. de (552) Larfinty-Tholosan, Marquis Jules (468) Laroche, Mme. Raymonde (36) Latzel, J. (700) Leblanc, Alfred (17) Lecomte, Henri (320) Legagneux, Georges (55) Le Lasseur de Ranzay, G. (479) Lemartin, Theodore (249) Lenfant, Louis (386) Leouet, B. L. (485) Leprince, P. (494) Lesire, Eugene (176) Lesseps, Jacques de (27) Leyat, Marcel (364) Lieutard, H. (497) Liger, A. (573) Lombardi, Henri (241) Loridan, Marcel (224) Magnan, Leon (379) Magneval, Gabriel (359) Mahieu, Georges E. (123) Mallet, J. A. P. (490) Mamet, Julien (18) Marchal, Anselem (328) Maron, P. H. (495) Marquezy, Rene (238) Martin, Edouard (365) Martin, Xavier (162) Martinet, Robert (78) Marvingt, Marie (281) Mauvais, Jean (144) Metrot, Rene (19) Meyer, Jules M. (229) Mignot, Robert (76) Miltgen, Paul (339) Moineau, R. L. (554) Molla, Henri (172) Montalent, O. de (509) Montjou, Guy de (446) Mollien, Elie A. (57) Molon, Leon (25) Molon, Louis (234) Molon, Lucien (235) Montigny, Alfred de (69) Morane, Leon F. (54) Morelle, Edmond (35) Morel, P. F. (524) Morin, Roger (306) Mouthier, Louis (157) Mousnier, Yvon (454) Niel, Albert (104) Niel, Mme. Marthe (226) Nissole, Edouard (383) Noe, A. G. M. (498) Noel, Andre (122) Obre, Emile (148) Ors, Jean (382) Orus, Maurice (256) Osmon, Geo. (361) Paillette, Marcel (99) Paillole, E. C. L. (556) Palade, Antoine (387) Pallier, Mdlle. Parent, Francois (189) Paris-Leclerc, Max (190) Partiot, G. (516) Pascal, Ferdinand (301) Paul, Ernest (91) Paulhan, Louis (10) Pequet, Henri (88) Perin, Albert (161) Perreyon, Edmond (311) Perrigot, J. (499) Picard, Pierre (174) Planchet, Edmond (319) Poillot (182) Pommier, Martin (400) Porcheron, L. A. (471) Pouleriguen, F. (349) Poumet (576) Pourpe, Marc Pourpe, M. M. E. A. (560) Prevost, M. (475) Prevoteau, G. (507) Prier, Pierre (169) Raoblt, Jean (386) Reimbert, Ernest (375) Reichert, Henri (377) Renaux, Eugene (139) Renaud de la Fregeoliere (396) Rey, P. A. P. (517) Reymond, Senator Richet, A. (537) Rigal, Victor (60) Rivolier, Jean (381) Robillard, G. de (184) Robinet, J. (476) Romance, F. de (288) Rougier, Henry (11) Ruby, F. L. (514) Ruchonnet (127) Sallard, H. (794) Sallenave, Henru (66) Savary, Robert (112) Schlumberger, M. (316) Sée, Raymond (187) Servies, Jules (218) Simon, Rene (177) Sommer, Roger (29) Tabateau, Maurice (128) Taurin, Andre (84) Tetard, Maurice (79) Thieulin, Joseph (459) Tissandier, Paul (13) Tixier, Henri (397) Toussin, Rene (56) Train, Emile Louis (167) Vallier, Edmond P. (269) Vallon, Rene (109) Van Gaver, Paul (338) Vasseur, Narcisse (282) Vedrines, Jules (312) Vendrines, E. (536) Verliac, Adrien (129) Vergmault, O. (561) Verrier, Pierre (390) Versepuy, Leon (149) Vialard, Charles (342) Vidart, Rene (133) Villeneuve Trans, Louis de (285) Vimard, E. (484) Visseaux, Henri (217) Vittoz-Gallet, G. (500) Wagner, Louis (83) Walleton, Louis (304) Weiss, H. (73) Wintrebert, Henri (300) Zens, Ernest (28) The following French aviators have been killed:-- +-------------------------+ | 1909. | | Ferber, Capt. | | Lefebvre, E. | | | | 1910. | | Blanchard (215) | | Delagrange, Leon (3) | | Le Blon (38) | | Poillot (182) | | | | 1911. | | Byasson, Lt. | | Camine, Capt. | | Caumont, Lieut. (156) | | Carron, Capt. | | Chotard, Lieut. | | De Grailly, Lieut. | | Desparmet, J. (451) | | Dupuis, Lieut. | | Gaubert (59) | | Laffont, A. (111) | | Lautheaume, Lt. | | Level | | Liere, Louis | | Loder, Lt. | | Madiot, Capt. (106) | | Mommlin | | Nieuport, E. (105) | | Noel | | Princeteau, Lt. (331) | | Ruchonnet | | Tarron, Capt. | | Vallon, Rene | | Wachter, C. L. (53) | +-------------------------| ~FRENCH PRIVATE AVIATORS, 1912.~ Adam-Gironne (818) Arondel, P. (827) Andenis, C. (788) Badet (622) Balighant, G. (588) Barbarou, M. (702) Basano, F. (828) Baudrin, E. (609) Bedel, R. (668) Beatrix, C. (781) Benoit, O. (771) Benoist, G. (667) Bertin, L. (801) Blaignan (633) Bleu, Le (643) Boiteau, G. (833) Boerlage (666) Bordage, A. (650) Boncour (678) Boucher, F. (600) Borie, A. (803) Brocard, A. (770) Brodin, E. (838) Brouard, E. (807) Bruginere, A. (813) Cailleaux, A. (617) Carreard, G. (779) Castellan, E. (639) Cavalier, M. (764) Caye, M. (672) Cerantes, F. (611) Chabert, V. (631) Chandenier, L. (804) Coblyn, L. (735) Contre (657) Corsini, A. (654) Cornier, R. (605) Coville, F. (594) Couffin, L. (619) Dambricourt, J. (773) De Beausire de Seyssel (756) Debroutelle, P. (806) De Chabot, P. (783) De Gensac, A. (836) De Lareinty Tholozan, H. (822) Delacour, J. (602) Delaunay, P. M. (635) Deleraye, M. (790) De l'Escaille (791) Delmas, M. (837) De Marmies, R. (663) De Mazurkiewicz, W. C. (707) Denhaut, F. (690) Des Pres de la Morlais (636) De Pontac (596) De Reals, R. (686) De Ryk (Mme. B.) (652) De Segonac, R. (669) Desille, L. (581) De Vergnette, C. (792) De Villepin, O. (832) Do Huu, T. (649) Drouhet, F. (727) Dussot, A. (733) Dutertre, C. (748) Ecomand, G. (714) Ehrmann, L. (646) Escot, P. (624) Eymien, S. (726) Fassin, F. (844) Faucompre, L. (814) Fleiche, L. (729) Foudre, R. (808) Foulquier, M. (772) Francois, A. (665) Galon, S. (613) Garros, R. (811) Glaize, F. (845) Godot, J. (815) Grazzioli, A. (687) Grasset, A. (800) Greppo, J. (676) Guerre, P. (730) Guillaux, E. (749) Hanne, A. (681) Helen, E. (586) Hembert (662) Hurard, J. (757) Hustinx, C. (716) Irate, G. (655) Jacquin, A. (582) Jailler, L. (682) Jeannerod, H. (696) Jeansoulin, L. (703) Joachim, H. (610) Jourjon, R. (841) Junquet, P. (621) Kormann (789) Lambert, A. (618) Lanier, P. (684) Lantheaume, C. (616) Latzel, J. (700) Le Bleu, P. (643) Leclerc, P. (593) Lefebvre, L. (691) Lecontellec, H. (810) Lenfant, P. (731) Lemoine, A. (632) Leroy, J. (638) Lesne, M. (796) Levasseur, J. (743) Le Vassor, J. (704) Lewis, J. (642) Loubignac, L. (793) Lumiere, G. (840) Madon, G. (595) Magnin, L. (648) Maicon, A. (695) Mandelli, P. (762) Mauger, D. (750) Malecaze, J. (776) Mancarot (710) Mazier, L. (634) Melin, E. (699) Metairie, A. (689) Mouroux, J. (724) Navarre, A. (584) Noel, L. (656) Nove-Josseraud (825) Olivier, L. (556) Pasquier, Baron R. (728) Penet, H. (809) Pia, G. (829) Picard, F. (601) Poulet, E. (709) Radisson, V. (834) Raulet, F. (658) Richer, H. (607) Ridont, R. (817) Roussel, L. (659) Roux, H. (715) Saint-Michel Rivet (604) Sallard, H. (794) Sauson de Sausal (812) Schneegaus, C. (712) Senart, J. (661) Sensever, H. (580) Senougue, A. (823) Serant, L. (679) Seyrat, J. (830) Shigeno, K. (744) Soularis, M. (698) Soyer, H. (671) Testulat, P. (821) Thierry de Ville d'Avray (579) Thoret, J. (708) Tierch, M. (645) Tournier, A. (677) Trescartes, L. (842) Vallet, C. (734) Vaudelle, R. (785) Vandinck, A. (787) Vandal, P. (598) Ventre, L. (585) Vidal Soler, E. (686) Vogoyeau, A. (755) Whitehouse, W. (589) Zens, P. (675) Zorra, L. (653) ~Killed.~ +---------------------------------+ | 1912. | | Barillon (307) | | Bedell, R. | | Bernard, Suzanne | | Boerner, Lieut. | | Boncour, Lieut. | | Bressand, Lieut. | | Chanteriers, Lieut. | | Dubois, Capt. | | Ducourneau, Lieut. | | Etienne, Lieut. | | Faure, Capt. | | Lacour | | Madiot, Capt. (106) | | Maguet, Capt. le | | Nieuport, C. | | Olivers, G. | | Peignan, Lieut. A. | | Poutrin, Lieut. | | Sevelle, Lieut. H. P. | | Thiery de Ville d'Avray, Lieut. | | Thomas, Lieut. | | Wagner, A. | | | | 1913. | | Bresson, Lieut. | +---------------------------------+ FRENCH AEROPLANES. ~A~ AERIENNE. L'Aerienne, 25 Quai des Grands Agustins, Paris. Builds to specifications and supplies all parts. ANTOINETTE. Company has ceased to exist. ASTRA. "Astra" Soc. de Constructions Aéronautiques, (Anciens Etabs. Surcouf) Soc. An'yme 13 Rue Couchat, Billancourt (Seine). Works: 121-123 Rue de Bellevue, Billancourt. Flying grounds: Issy-les-Molineux Villacoublay (S-&-O). This old established balloon and dirigible firm first took up aviation as French agents for the _Wrights_ in 1909. For a time they built _Wrights_ with certain modifications, but by 1912, little save the Wright system of warping remained. Capacity: about 100 machines a year. +------------------------------+-----------------+-----------------+-----------------+-----------------+----------------- | Biplane, | Military | Biplane, | Mil. biplane, | Hydro-biplane, | type C. | biplane | Type C. | type C.M. | type C.M. | ~1912-13.~ | type C.M. | ~1913.~ | ~1913.~ | ~1913.~ | Wood. | ~1912-13.~ | Wood & steel. | Wood & steel. | Wood & steel | | Wood | | | -------------------------------+-----------------+-----------------+-----------------+-----------------+----------------- ~Length~ feet (m.)| 34 (10.40) | 36 (10.97) | 34 (10.40) | 36 (10.97) | 32-3/4 (10) ~Span~ feet (m.)| 41 (12.50) | 40-1/2 (12.32) | 41 (12.50) | 40-1/2 (12.32) | 39-1/2 (12) ~Area.~ sq. feet (m²)| 519 (48.2) | 519 (48.2) | 519 (48.2) | 519 (48.2) | 519 (48.2) {machine lbs. (kgs.)| 1764 (800) | 2365 (1073) | ... | 1411 (640) | 1763 (800) ~Weight~ { | | | | | (unladen) {useful lbs. (kgs.)| 661 (300) | 882 (400) | ... | ... | ... ~Motor~ h.p.| 50 Renault | 75 Renault | 50 Renault | 75 Renault | 100 Renault | | or 75 Chenu | | | {max. m.p.h. (km.)| 56 (90) | 56 (90) | 56 (90) | 56 (90) | 56 (90) ~Speed~ { | | | | | {min. m.p.h. (km.)| ... | ... | ... | ... | ... ~Endurance~ hrs.| ... | ... | ... | ... | ... Number built during 1912 | ... | ... | ... | ... | ... -------------------------------+-----------------+-----------------+-----------------+-----------------+----------------- Remarks.--The 1912-13 and 1913 types differ only in the adoption of metal in the 1913 models, which are consequently considerably lighter. General features.--Warping wings. Fixed tail planes with two elevators in rear. Single rudder. Single tractor geared down 1 to 2. Type C carries 85 litres petrol; type C.M., 137 litres. [Illustration: Astra. Military "C.M." 1913.] [Illustration: Astra. Hydro-avion, 1913.] ~B~ BERTIN. L. Bertin, 23 rue de Rocroy, Paris. About 1908 Bertin began building helicopters. The machine below was exhibited in the 1913 Paris Salon. [Illustration: Bertin. UAS.] ------------------------------+-------------+ | ~1913.~ | | Monoplane. | | 2-seater. | ------------------------------+-------------+ ~Length~ feet (m.)| 29 (8.80) | ~Span~ feet (m.)| 34 (10.40) | ~Area~ sq. feet (m².)| 226 (21) | {machine, lbs. (kgs.)| 770 (350) | ~Weight~ { | | {useful lbs. (kgs.)| ... | ~Motor~ h.p.| 100 Bertin | ~Speed~ {max m.p.h. (km.)| 71 (115) | Number built during 1912 | 1 | ------------------------------+-------------+ Remarks.--Wood and steel construction. On wheels only. _Controls:_ warping and rear elevator. BESSON. Marcel Besson, 24 rue Marbeuf, Paris. Capacity: small. Besson first appeared in 1911 with a tail-first mono. In the Paris Salon, 1913, he exhibited an improved machine along similar lines. ------------------------------+-------------+ | ~1913~ | | _Canard_ | | 2-seater. | ------------------------------+-------------+ ~Length~ feet (m.)| 22 (6.70) | ~Span~ feet (m.)| 44 (13.40) | ~Area~ sq. feet (m².)| 323 (30) | {machine, lbs. (kgs.)| 730 (331.2) | ~Weight~ { | | {useful lbs. (kgs.)| ... | ~Motor~ h.p.| 70 Gnome | ~Speed~ m.p.h.(km.)| 59 (95) | Number built during 1912 | 1 | ------------------------------+-------------+ Remarks.--All steel construction. On wheels and 2 skids. _Control:_ ailerons and front elevator. BLERIOT Monoplanes. L. Bleriot, "Bleriot-Aeronautique," 39, Route de la Révolte, Paris-Levallois. Flying grounds: Buc Etampes and Pau. L. Bleriot began to experiment in 1906, along Langley lines. By 1909 he was one of the leading French firms; and the first cross Channel flight was made by him. Details of standard types:-- -----------------------------+----------------+----------------+---------------+---------------+---------------+------------ | | ~XXI.~ | ~XXVII.~ | | | | ~XI~ _bis._ | Military | Single seat | ~XXVIII.~ | ~XXVIII.~ | Monocoque | 2-seater mono. | side by side | mono. | Single seater | 2-seater | 2-seater |(~1911~ onward) | 2-seater mono. | ~1912.~ | ~1913.~ | ~1913.~ | ~1913.~ | | ~1912.~ | | | | -----------------------------+----------------+----------------+---------------+---------------+---------------+------------ ~Length~ feet (m)| 27-1/3 (8.40) | 27-1/4 (8.24) | 28 (8.50) | 25 (7.60) | 27 (8.20) | ... ~Span~ feet (m)| 36 (11) | 36 (11) | 29-1/2 (9) | 29 (8.80) | 32 (9.75) | 40 (12.25) ~Area~ sq. ft. (m².)| 349 (33) | 268 (25) | 129 (12) | 162 (15) | 215 (20) | 270 (25) {unladen, lbs. (kgs)| ... | 727 (330) | 529 (240) | 530 (240) | 660 (300) | 830 (375) ~Weight~ { | | | | | | {useful lbs. (kgs.)| ... | ... | ... | 286 (129) | 550 (250) | ... ~Motor~ h.p.| 50 Gnome | 70 Gnome | 70 Gnome | 50 Gnome | 70 Gnome | 80 Gnome {max. m.p.h. (km.)| 56 (90) | 56 (90) | 78 (125) | 62 (100) | 71 (115) | 75 (120) ~Speed~ { | | | | | | {min. m.p.h. (km.)| ... | ... | ... | ... | ... | ... ~Endurance~ hrs.| ... | ... | ... | ... | ... | ... Number built during 1912 | ... | ... | ... | ... | ... | ... -----------------------------+----------------+----------------+---------------+---------------+---------------+------------ Note.--The monos., as usual, are of wood construction; wheels only for landing. Rectangular section bodies. Warping wings, elevator in rear. Chauviere propeller. The monocoque has wood, steel and cork construction. Coque body. Skids to landing chassis. Levasseur propeller. Otherwise as the other monos. Principal _Bleriot_ flyers are or have been:--Aubrun, Balsan, Bleriot, Busson, Chavez, Cordonnier, Delagrange, Drexel, Efimoff, Gibbs, Hubert, Hamel, Moissant, Paulhan, Prevetau, Prevot, Prier, Radley, Thorup, Tyck, Wienzciers, and many others. [Illustration: Bleriot XI _bis._] [Illustration: 1913 type of XI _bis._ UAS.] [Illustration: Bleriot XXVII.] [Illustration: BLÉRIOT XXI. UAS. General standard type of _Bleriot_ 1912 & 1913.] ~Special types of Bleriots.~--In addition to the standard machines, Bleriot from time to time produces special machines, of which the best known is the _Limousine_, built for M. Deutsch de la Meurthe, built 1911 and still existing. One or two Canards have also been built, including an armoured military. [Illustration: BLERIOT-LIMOUSINE. UAS.] Early in 1913 a special experimental military machine was produced with considerable secrecy. [Illustration: BLERIOT MILITARY. Special 1913 military. UAS.] BOREL. G. Borel & Cie, 25 rue Brunel, Paris. Established 1910. Capacity: about 25 machines a year. -----------------+----------------------+----------------------+--------------------- Model. | ~1913.~ | ~1913.~ | ~1913.~ | Monoplane. | Monocoque Racer. | Hydro-mono. | | | 2-seater. -----------------+----------------------+----------------------+--------------------- ~Length~ | 22 feet (6.70 m.) | 19 feet (5.80 m.) | 27 feet (8.30 m.) ~Span~ | 30 feet (9.15 m.) | 26 feet (8.00 m.) | 37 feet (11.25 m.) ~Area~ | 152 sq. ft. (14 m².) | 116 sq. ft. (11 m².) | 237 sq. ft. (22 m².) {total | 530 lbs. (240 kgs.) | 608 lbs. (276 kgs.) | 880 lbs. (399 kgs.) ~Weight~ { | | | {useful | 287 lbs. (130 kgs.) | ... | ... ~Motor~ | 50 Gnome | 80 Gnome | 80 Gnome ~Speed~ (p.h.)| 71 m. (115 km.) | 94 m. (150 km.) | 62 m. (100 km.) -----------------+----------------------+----------------------+--------------------- Note.--The monocoque is of wood and steel construction, the others wood only. The monocoque has coque body, the others ordinary rectangular section. Floats of the hydro as illustrated. For the rest the ordinary mono. is practically on the same lines as the 1912. The racer is somewhat on _Deperdussin_ lines, but the body is built up inside. No fixed tail. The hydro. is an enlarged edition of the mono. Floats display nothing very original, except that a float under tail is interconnected with the rudder, and that the two front floats are fitted for being rowed. Fitted with a self-starter. [Illustration: 1913 Borel. Hydro-avion. _By favour of "Flight."_ UAS.] [Illustration: Hydro-avion.] There is also a Denhaut design, 1913, about the same as a _Donnet-Leveque_. [Illustration: Borel. Monocoque. UAS.] BREGUET. Soc. Anonyme des ateliers d'aviation, Louis Breguet, 16 Boulevard Vauban, Donai (Nord). Capacity: about 200 machines a year. Paris office: 25, Boulevard Jules Sandeau. Schools at La Brayelle, pris Douai, Vélisy-Villacoublay, pris Paris. ----------------------------------+------------------+------------------+-------------------+------------------+------------------ | | | | | Aérhydroplane | ~G2~ bis. | ~G3.~ | ~C-U1.~ | ~C-U2.~ | tandem ~1913 models.~ | 2 or 3-seater | 3-seater | 2-seater | 2-seater | mono. | biplane. | biplane. | biplane. | biplane. | 2-seater, | | | | | side by side. ----------------------------------+------------------+------------------+-------------------+------------------+------------------ ~Length~ feet (m)| 33 (10) | 29 (8.75) | 29 (8.75) | 29 (8.75) | 29 (8.75) ~Span~ feet (m)| 49 (15) | 45 (13.65) | 45 (13.65) | 45 (13.65) | 42 (12.80) ~Area~ sq. feet (m²)| 376 (35) | 377 (36) | 387 (36) | 387 (36) | 387 (36) {empty, lbs. (kgs.)| 1323 (600) | 1212 (550) | 1430 (649) | 1160 (522) | 1760 (798) ~Weight~ { | | | | | {useful lbs. (kgs.)| 662 (300) | 882 (400) | 662 (300) | 882 (400) | 662 (300) ~Motor~ h.p.| 80 Gnome | 100 Gnome | 80 Canton Unmé. | 110 Canton Unmé. | 110 Canton Unmé. {max. m.p.h. (km.)| 62 (100) | 69 (110) | 62 (100) | 71 (115) | 87 (140) ~Speed~ { | | | | | {min. m.p.h. (km.)| ... | ... | ... | ... | 62 (100) ~Endurance~ hrs.| 3-1/2 | 4 | 7 | 7 | 7 Number built during 1912 |A total of 41 sold| during 1912 for| military purposes.| | ... ----------------------------------+------------------+------------------+-------------------+------------------+------------------ _In each case._-- ~Construction.~--All steel. ~Landing chassis.~--C consists of three wheels each protected by skids. The two main wheels, placed on either side of the centre of gravity, are fitted with patent "Oleopneumatic" shock absorbers. The steering wheel and the front skid have a spring suspension. ~Military machines.~--The 1912 sales of these were:--32 to France; 5 British; 3 Italian; 1 Swedish. ~Steering.~--The patented control system consists of a wheel mounted on a pivoted lever. The backward and forward movement of the entire system operates the elevator: the sideway movement warps the rear edge of the upper wings, and the rotation of the wheel steers the machine. The latter operation also governs the front wheel of the landing chassis, so that when on the ground the machine can be steered like a motor car. ~Portability.~--The main planes can be folded alongside of the fuselage. The machine can then be towed on any ordinary road, or be housed in places such as farm buildings, stables, &c. [Illustration: Aerhydroplane, 1913-14.] [Illustration: BREGUET. Hydro. UAS] [Illustration: BREGUET. Biplane. UAS] [Illustration: BRÉGUET. 1912-13, G3 type 3-seater military. UAS] C CAUDRON. Caudron Fréres, Rue (Somme). Schools: Crotoy and Juvissy. Capacity: about 100-250 a year. -----------------------------------+--------------------+--------------------+--------------------+--------------------++--------------------+--------------------++--------------------+------------------------ | ~M2~ | ~N.~ | ~G.D.~ | || ~B.~ | ~E.~ || Monaco type, | Model and Date. | 1912-13 | 1912-13 | 1912-13 | ~1913~ || 1912-13 | 1912-13 || 1912 | ~1913~ | mono. | mono. | mono. | mono. || biplane. | biplane. || hydro-biplane. | hydro-biplane. -----------------------------------+--------------------+--------------------+--------------------+--------------------++--------------------+--------------------++--------------------+------------------------ ~Length~ feet (m.)| 20 (6.10) | 19-3/4 (6) | 22 (6.75) | 19-1/4 (5.80) || 26-1/4 (8) | 23-1/2 (7.15) || 22 (6.75) | 32-3/4 (10) ~Span~ feet (m.)| 31 (9.40) | 26-1/3 (8) | 34 (10.30) | 27-1/3 (8.50) || 32-3/4 (10) | 35-1/2 (10.80) || 33 (10.10) | 46 (14) ~Area~ sq. feet (m².)| 151 (14) | 108 (10) | 268 (25) | 118 (11) || 431 (40) | 301 (28) || 268 (25) | 376 (35) ~Weight~ machine, lbs. (kgs.)| 518 (235) | 496 (225) | 386 (175) | 490 (225) || 683 (310) | 640 (295) || 772 (350) | 882 (400) ~Motor~ h.p.| 50 Anzani or Gnome | 50 Anzani | Anzani or Gnome | 50 Gnome. || Anzani or Gnome | Gnome || Gnome | 70 Gnome ~Speed~ m.p.h. (km.)| 71 (115) | 84 (135) | 75 (120) | 84 || 56 (90) | 56 (90) || 50 (80) | 50 (80) Number built during 1912 | ... | ... | ... | ... || ... | ... || ... | ... -----------------------------------+--------------------+--------------------+--------------------+--------------------++--------------------+--------------------++--------------------+------------------------ || Lateral control, warping. Wood construction. Notes.--Lateral control, warping. Wood construction. On wheels. Enclosed body. || On wheels as well as || floats. (Special Caudron patent.) ------------------------------------------------------------------------------------------------------------------------------------------------------------------++--------------------------------------------- [Illustration: 1912 hydro. _By favour of "Aeronautics," U.S.A._ UAS] [Illustration: CAUDRON. UAS] [Illustration: 1913 hydro. UAS] [Illustration: CAUDRON. Mono. _By favour of "Flight."_ UAS] CLEMENT-BAYARD. Usines Clement-Bayard, 33 quai Michelet, Levallois-Perret (Seine). [Illustration] ----------------------------------+------------------------+------------------------+ | ~1913.~ | ~1913.~ | | Military 3-seater | Military single seater | | biplane. | monoplane. | ----------------------------------+------------------------+------------------------+ ~Length~ feet (m)| 37 (11.20) | 24-2/3 (7.50) | {upper feet (m)| 52 (16) | 30 (9.20) | ~Span~ { | | | {lower feet (m)| 36 (11) | ... | ~Area~ sq. feet (m².)| 533 (50) | 172 (16) | {total lbs. (kgs.)| 2425 (1100) | 1146 (520) | ~Weight~ { | | | {useful lbs. (kgs.)| 1014 (460) | 441 (200) | ~Motor~ h.p.| 100 Gnome | 70 Gnome | {max. m.p.h. (km.)| 53 (85) | 75 (120) | ~Speed~ { | | | {min. m.p.h. (km.)| ... | ... | ~Endurance~ hrs.| ... | ... | ----------------------------------+------------------------+------------------------+ Notes.--_Control_: lateral, warping. D D'ARTOIS. Soc. Anonyme des Anciens Chantiers Tellier, Longuenesse, pres St. Omer. Re-established 1912. Capacity: small. ---------------------------------+--------------------+--------------------+ | ~1913~ model. | ~1913~ | Model and date. | "Aero torpille" | "Aero torpille" | | hydro-biplane. | biplane. | ---------------------------------+--------------------+--------------------+ ~Length~ feet (m.)| 23 (7) | 24-3/4 (7.50) | {| 36 (11) | 36 (11) | ~Span~ feet (m.){| | | {| 20 (6) | 20 (6) | ~Area~ sq. feet (m².)| 280 (26) | 280 (26) | ~Weight~ empty, lbs. (kgs.)| 772 (350) | 551 (250) | ~Motor~ h.p.| 50 Gnome | 50 Gnome | ~Speed~ m.p.h. (km.)| 56 (90) | 84 (135) | ~Endurance~ hrs.| ... | ... | Number built during 1912 | ... | ... | ---------------------------------+--------------------+--------------------+ Notes.--Single long boat body, canoe-shape. [Illustration: _By favour of "Aeronautics," U.S.A._ UAS] DEPERDUSSIN. Armand Deperdussin, 19 rue des Entrepreneurs, Paris. School: Courey-Betheny (Marne). Established 1910. Capacity: about 150-200 machines a year. ----------------------------------+--------------------+--------------------+--------------------+--------------------+--------------------+-------------------- | ~E 1912-13.~ | ~P 1912-13.~ | ~T 1912-13.~ | ~H 1912-13.~ | Monocoque | Mono. | school mono. | single seater | 2-seater | 3-seater | ~1913.~ | ~1913.~ | | mono. | mono. | mono. | 2-seater. | 2-seater. ----------------------------------+--------------------+--------------------+--------------------+--------------------+--------------------+-------------------- ~Length~ feet (m)| 24 (7.30) | 24 (7.30) | 24 (7.30) | 29 (8.80) | 19 (5.75) | ... ~Span~ feet (m)| 29 (8.85) | 28 (8.50) | 35 (10.65) | 41 (12.50) | 29-1/2 (8.95) | 36 (11) ~Area~ sq. feet (m².)| ... | 162 (15) | ... | 310 (28) | 97 (9) | ... {total lbs. (kgs.)| 661 (300) | 782 (355) | 1212 (550) | 2050 (930) | 882 (400) | ... ~Weight~ { | | | | | | {useful lbs. (kgs.)| ... | ... | ... | ... | ... | ... ~Motor~ h.p.| 30 Anzani | 50 Gnome | 70 Gnome | 100 Gnome | 50 Gnome | 80 Gnome {max. m.p.h. (km.)| 50 (80) | 69 (110) | 65 (105) | 69 (110) | 113 (180) | 105 (170) ~Speed~ { | | | | | | {min. m.p.h. (km.)| ... | ... | ... | ... | 81 (130) | ... ~Endurance~ hrs.| ... | ... | ... | ... | ... | ... Number built during 1912 | 2 | 5 | 27 | 3 | 2 | 1 ----------------------------------+--------------------+--------------------+--------------------+--------------------+--------------------+-------------------- Notes.--Wood construction. Lateral control by warping. Mounted on wheels without skids. Fabric: "Aviator" Ramie. Principal _Deperdussin_ records: 1912 Gordon Bennett (Vedrines) and a number of world records for speed and distance. Principal pilots include: Busson, Prévost, Vedrines, Vidart. [Illustration: 50 h.p. monocoque.] [Illustration: DEPERDUSSIN. 80 h.p. UAS] [Illustration: The 80 h.p. mounted on floats as a hydro.] DONNET-LEVEQUE. ---------------------------+--------------------+--------------------+--------------------+-------------------- | ~A 1912.~ | ~B 1912.~ | ~C 1912.~ | ~1913.~ | 2-seater | 2-seater | 3-seater | 2-seater | hydro-biplane | hydro-biplane | hydro-biplane | hydro-biplane ---------------------------+--------------------+--------------------+--------------------+-------------------- ~Length~ feet (m)| 26 (7.80) | 27 (8.30) | 27 (8.30) | 34-1/2 (10.50) ~Span~ feet (m)| 29-1/2 (9) | 32-3/4 (10) | 34-1/2 (10.50) | 29-1/2 (9) ~Area~ sq. feet (m².)| 194 (18) | 215 (20) | 237 (22) | 194 (18) ~Weight~ lbs. (kgs.)| 683 (310) | 772 (350) | 888 (380) | 888 (380) ~Motor~ h.p.| 50 Gnome | 70 Gnome | 80 Gnome | 50 Gnome ~Speed~ m.p.h. (km.)| 69 (110) | 75 (120) | ... | 50 (80) ~Endurance~ hrs.| ... | ... | ... | ... Number built during 1912 | ... | ... | ... | ... ---------------------------+--------------------+--------------------+--------------------+-------------------- Notes.--Lateral control by warping ailerons. Motor in gap just below upper plane: propeller in rear, direct driven. Fabric: "Aviator" Ramie. Floats.--One large central boat 27 feet (8.20 m.) long--two small ones at each extremity of lower plane. [Illustration: _By favour of "Aeronautics," U.S.A._] [Illustration: UAS] DOUTRE. Soc. Anonyme Doutre, 58, rue Talbot, Paris. -----------------------------------+--------------------+--------------------+ Type. | Biplane 3-seater, | Biplane 2-seater, | | ~1912-13.~ | ~1912-13.~ | -----------------------------------+--------------------+--------------------+ ~Length~ feet (m.)| 40 (12.25) | ... | {| 53 (16.10) | ... | ~Span~ feet (m.){| | | {| 43 (13) | ... | ~Area~ sq. feet (m².)| 533 (50) | ... | {machine lbs. (kgs.)| 1323 (600) | 1323 (600) | ~Weight~ { | | | {useful lbs. (kgs.)| 992 (450) | 992 (450) | ~Motor~ h.p.| 70 Renault | 50 Renault | ~Speed~ max. m.p.h (km.)| 56 (90) | 56 (90) | Number built during 1912 | 1 | ? | -----------------------------------+--------------------+--------------------+ Notes.--Fabric: "Aviator" Ramie. Both types fitted with the Doutre patent stabiliser, which automatically and instantaneously counteracts troubles due to sudden gusts or partial motor failures. Weight of the 1913 model stabiliser is only 44 lbs. (20 kgs.) [Illustration: Model 1913 stabiliser.] [Illustration: DOUTRE. UAS] F FARMAN. Henry and Maurice Farman, 167, Rue de Silly, Billancourt (Seine) Aerodromes: Buc, pres Versailles and Etampes. Depots: Camp de Chalons--Reims. Established by H. Farman in 1908. M. Farman established works a little later. In 1912 the two brothers combined. The present works were opened in January, 1912, and had an output capacity of at least 300 machines a year in March, 1913. ---------------------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+-------------------- | _H. Farman._ | _H. Farman._ | _H. Farman._ | _H. Farman._ | _M. Farman._ | _M. Farman._ | _M. Farman._ | Military. | Single-seater. | 2-seater | 2-seater special | Military biplane. | Big military | Staggered | 2 or 3-seater. | Military. | monoplane. | hydro-biplane. | | biplane. | biplane. | ~1912-13.~ | ~1913.~ | | ~1913.~ | | | | Biplane. | Biplane. | | | | | ---------------------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+-------------------- ~Length~ feet (m.)| 26-1/4 (8) | 24 (7.35) | 24-1/2 (7.50) | 26 (7.90) | 39-1/3 (12) | 46 (14) | 39 (11.90) ~Span~ feet (m.)| 42-3/4 (13.25) | 31-1/8 (9.50) | 32-3/4 (10) | 45 (13.70) | 50-3/4 (15.50) | 65-3/4 (20) | 36 (11) ~Area~ sq. feet (m².)| 376 (35) | 161 (15) | 204 (19) | 344 (32) | 646 (60) | 861 (80) | 323 (30) {total lbs. (kgs.)| 793 (360) | 640 (295) | 628 (285) | 950 (431) | 1102 (500) | 1433 (650) | 882 (400) ~Weight~ { | | | | | | | {useful lbs. (kgs.)| 661 (300) | 386 (175) | ... | ... | 617 (280) | 882 (400) | 551 (250) {| | | Designed for | | | | ~Motor~ h.p.{| 70-80 Gnome | 70-80 Gnome | Gnomes from | 50 Gnome | 70 Renault | 70 Renault | 70 Renault {| | | 40 up to 160 h.p. | | | | {max. m.p.h. (km)| 65 (105) | 71 (15) | ... | 52 (100) | 56 (90) | 44 (70) | 69 (110) ~Speed~ { | | | | | | | {min. m.p.h. (km)| ... | ... | ... | ... | ... | ... | ... ~Endurance~ hrs.| 3 | ... | ... | ... | ... | ... | ... Number built during 1912 | ... | ... | ... | ... | ... | ... | ... ---------------------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+-------------------- Remarks.--The whole of the above can easily be converted into hydro-avions--two long narrow floats without steps. _H. Farmans_ are of wood and steel construction; _M. Farman_, wood. In all 1913 biplanes the ailerons are inter-connected. All 1913 machines designed to carry one or in some cases two mitrailleuse, and special attention is paid to facility for taking down for transport and re-assembling. The 1911-12 _H. Farmans_ had elevators forward, were a good deal longer, and had more surface than 1913 models. Ailerons not inter-connected. The _M. Farmans_ generally as now, except that all planes, etc., had rounded edges. On September 11th, 1912, Foury, in an _M. Farman_ military, made world's endurance record to date, 13 hrs. 22 min., covering 631 miles (1,017 km.) All models of this type, also the "big military," are fitted with the Doutre stabiliser. Fabric: "Aviator" Ramie. ~Latest Hydro.~--In March, 1913, a new hydro was produced experimentally. There is a boat body, without steps, carrying the motor which is chain connected with the propeller. Machine is fitted with wheels and skids as well. [Illustration: H. Farman. 1912-13 military biplane.] [Illustration: H. Farman. 1913 latest type military biplane.] [Illustration: M. Farman. 1912-13 military biplane.] [Illustration: M. Farman. 1912-13 staggered biplane. This is the type which has done best as a hydro-aeroplane.] G GOUPY. A. Goupy, 50, Avenue Marceau, Paris. School: Juvissy (Port Aviation). Capacity: about 30 machines a year. -----------------------------------+--------------------+--------------------+-------------------- | | | ~1913.~ Model and date. | ~1913 A.~ | ~1913 B.~ | Hydro-staggered | Staggered biplane. | Staggered biplane. | biplane. -----------------------------------+--------------------+--------------------+-------------------- ~Length~ feet (m.)| 25 (7.50) | 26-1/4 (8) | 33 (10) ~Span~ feet (m.)| 26-1/4 (8) | 42-3/4 (13) | 42 (12.70) ~Area~ sq. feet (m²)| ... | ... | 480 (45) {machine lbs. (kgs.)| ... | ... | 992 (450) ~Weight~ { | | | {useful lbs. (kgs.)| ... | ... | 661 (300) ~Motor~ h.p.| 50 Gnome | 80 or 100 Gnome | 80 Gnome {max. m.p.h. (km.)| 62 (100) | 75 (120) | 75 (120) ~Speed~ { | | | {min. m.p.h. (km.)| ... | ... | ... ~Endurance~ hrs.| ... | ... | ... Number built during 1912 | ... | 12 | 1 -----------------------------------+--------------------+--------------------+-------------------- Fabric: "Aviator" Ramie. [Illustration: Goupy. Hydro. _From "Flight."_ UAS] [Illustration: Goupy. Hydro. _By favour of "Aeronautics," U.S.A._ UAS] H HANRIOT. Aeroplanes Hanriot & Cie., 145 rue de Neufchatel, Reims. Paris office: 69 boulevard Berthier, Paris. School: Antibes, Reims. ------------------------------+--------------------+--------------------+--------------------+--------------------+-------------------- ~1913~ models. | ~D I.~ | ~D II.~ | ~D III.~ | ~D IV.~ | ~D VII.~ ~Monoplanes.~ | Single seater. | 2 or 3-seater. | Racer. | Steel. | ------------------------------+--------------------+--------------------+--------------------+--------------------+-------------------- ~Length~ feet (m.)| 23 (7) | 26-1/3 (8) | 21-3/4 (6.65) | 23 (7) | 23 (7) ~Span~ feet (m.)| 28-1/3 (8.70) | 42-3/4 (13) | 24 (7.30) | 28-1/3 (8.65) | 36 (10.95) ~Area~ sq. feet (m²)| 161 (15) | 226 (21) | 91 (8.50) | 161 (15) | 194 (18) {machine lbs. (kgs.)| 661 (300) | 937 (425) | 661 (300) | 661 (300) | 771 (350) ~Weight~ { | | | | | {useful lbs. (kgs.)| ... | 616 (280) | ... | 396 (180) | 364 (165) ~Motor~ h.p.| 50 Anzani | 100 Gnome | 100 Gnome | 50 R. Peugeot | 80 Gnome {max. m.p.h. (km.)| 69 (110) | 78 (125) | 106 (170) | 71 (115) | 71 (115) ~Speed~ { | | | | | {min. m.p.h. (km.)| ... | ... | ... | ... | ... ~Endurance~ hrs.| ... | ... | ... | ... | ... Number built during 1912 | ... | ... | ... | ... | ... ------------------------------+--------------------+--------------------+--------------------+--------------------+-------------------- Notes.--There are also two school types 35 and 45 h.p. Records include 1912 world record for speed with passengers. None of the above machines represent any very particular divergence from recognised _Hanriot_ practice. _D IV_ is all steel construction, the others wood and steel. [Illustration] M MORANE-SAULNIER. Soc. de constructions aéronautiques, Morane-Saulnier. 206 Boulevard Pereire. Capital: 1,500,000 francs. School: Villacoublay. Output capacity: about 50 machines a year. ----------------------------------+--------------------+-------------------- | ~Military, 1913.~ | ~2 places.~ | | ~Tandem.~ ----------------------------------+--------------------+-------------------- ~Length~ feet (m.)| 21 (6.38) | 21 (6.38) ~Span~ feet (m.)| 30-1/5 (9.20) | 33-1/2 (10.20) ~Surface~ sq. feet (m².)| 151 (14) | 172 (16) {total lbs. (kgs.)| 595 (270) | 617 (280) ~Weight~ { | | {useful lbs. (kgs.)| ... | ... ~Motor~ h.p.| 50 h.p. | 80 h.p. ~Speed~ m.p.h. (km.)| 75 (120) | 75 (120) Number built during 1912 | ... | ... ----------------------------------+--------------------+---------------------- In each case ~body~ is of rectangular section, wood, mounted on wheels only, except for the ~military~ type which has skids also. Fabric: "Aviator" Ramie. In all there is a rear elevator and a Chauvière tractor. Note.--Flown in the European Circuit, 1911, by Vedrines, Gajet, Lesire, Morisson, Verept, Frey, Garnier and Dalgier. [Illustration] [Illustration: 1913. 100 h.p. Gnome engined.] MOREAU. Moreau fréres, Combs-la-Ville. -----------------------------------+--------------------+ | ~1913.~ | Model and date. | 2-seater. | -----------------------------------+--------------------+ ~Length~ feet (m.)| 31 (9.50) | ~Span~ feet (m.)| 39-1/3 (12) | ~Area~ sq. feet (m².)| 258 (24) | {machine lbs. (kgs.)| 992 (450) | ~Weight~ { | | {useful lbs. (kgs.)| ... | ~Motor~ h.p.| 70 Gnome | ~Speed~ max. m.p.h. (km.)| 62 (100) | Number built during 1912 | 2 | -----------------------------------+--------------------+ Notes.--Fitted with a special stabilising device. [Illustration: MOREAU. UAS] N NIEUPORT. Etablissements Nieuport, 9 rue de Seine, Suresnes (Seine). Established 1910 by the late Edouard Nieuport. Approximate capacity of works: about 100 machines a year. Chief designer during 1911 was Pagny, who has now joined the Hanriot firm. ----------------------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+-------------------- Model and date. | ~II N,~ | ~II G,~ | ~IV G, 1912-13.~ | ~IV M, 1912-13.~ | ~1913.~ | ~1913.~ | ~1913.~ | ~1913.~ ~Monoplanes.~ | ~1912.~ | ~1912.~ | 2-seater. | 3-seater. | 2-seater. | 1-seater. | 1-seater. | Hydro 3-seater. ----------------------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+-------------------- ~Length~ feet (m.)| 23-2/3 (7.20) | 23-2/3 (7.20) | 25-2/3 (7.80) | 25-2/3 (7.80) | 26-1/4 (8) | 21-3/4 (6.60) | 23 (7) | 29 (8.80) ~Span~ feet (m.)| 28-1/3 (8.65) | 28-1/3 (8.65) | 36 (10.90) | 39-1/3 (12.10) | 36 (11) | 28-1/3 (8.70) | 27-2/3 (8.40) | 40 (12.20) ~Area~ sq. feet (m².)| ... | ... | ... | ... | 231 (21-1/2) | 140 (13) | 156 (14-1/2) | 242 (22-1/2) {machine lbs. (kgs.)| 529 (240) | 683 (310) | 771 (350) | 1058 (480) | 771 (350) | 573 (260) | 573 (260) | 1230 (558) ~Weight~ { | | | | | | | | {useful lbs. (kgs.)| ... | ... | ... | ... | ... | ... | ... | ... ~Motor~ h.p.| 30 Nieuport | Gnome | Gnome | Gnome | Gnome | 50 Gnome | 30 Nieuport | 100 Gnome {max. m.p.h. (km.)| 75 (120) | 87 (140) | 72 (117) | 72 (117) | 69 (110) | 78 (125) | 69 (110) | 72 (117) ~Speed~ { | | | | | | | | {min. m.p.h. (km.)| ... | 75 (120) | 69 (110) | ... | ... | ... | ... | ... Number built during 1912 | ... | ... | ... | ... | ... | ... | ... | ... ----------------------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+-------------------- Notes.--Early types had a _Hanriot_ style landing carriage; the 1913 models revert to a _Bleriot_ type. Warping wings. Fuselage entirely enclosed, rectilineal with rounded nose. [Illustration: Nieuport. Hydro. _By favour of "Flight."_ UAS] P PAULHAN-CURTISS. Soc. anonyme d'aviation Paulhan, (S.A.P.) 71 boulevard Berthier, Paris. Flying ground: Bois d'Arcy par St. Ayr (S. et O.) Hydro school: Juan-les-Pins, par Antibes (Alpes Maritimes). Founded by the well-known aviator, L. Paulhan. He first produced biplanes, then triplanes and finally a monoplane type, the _Tatin-Paulhan_ (1911). These are now all abandoned, and the firm devotes itself to building hydro-aeroplanes under Curtiss (U.S.A.) license. Principal type built are:-- ------------------------------------+------------------+------------------+ Model and date. | Flying boat. | Flying boat. | ~Biplanes.~ | Single-seater. | 2-seater. | ------------------------------------+------------------+------------------+ ~Length~ feet (m.)| ... | 27 (8.30) | ~Span~ feet (m.)| 35-1/2 (10.80) | 37 (11.30) | ~Area~ sq. feet (m².)| ... | 290 (26-3/4) | {machine lbs. (kgs.)| ... | 948 (430) | ~Weight~ { | | | {useful lbs. (kgs.)| ... | ... | ~Motor~ h.p.| 75 Curtiss | 85 Curtiss | ~Speed~ m.p.h. (km.)| ... | ... | Number built during 1912 | 2 | 8 | ------------------------------------+------------------+------------------+ PISCHOFF. Établissements Autoplan, 4 rue Beranger, Boulogne sur Seine (Seine). This firm has produced various types in the past, but at present, appears confined to constructing to specifications (See _Pischoff-Werner_ last edition). [Illustration: Paulhan-Curtiss. Flying boat.] R R.E.P. Robert Esnault-Pelterie, Billancourt. School: Bue. One of the earliest established French firms. The first to go in for steel construction. Reported to have amalgamated with _Breguet_ in 1912, but this fell through. -----------------------------------+------------------+------------------+------------------+------------------+------------------+ Model. | ~1912.~ | ~1912.~ | ~1912.~ | ~1913.~ | ~1913.~ | ~Steel monoplanes.~ | 1-seater. | 2-seater. | Military. | 2-seater. | Hydro-mono. | | | | 3-seater. | | 2-seater. | -----------------------------------+------------------+------------------+------------------+------------------+------------------+ ~Length~ feet (m.)| 25-1/3 (7.70) | 25-1/3 (7.70) | 25-1/3 (7.70) | 23 (7) | 25 (7.50) | ~Span~ feet (m.)| 35 (10.70) | 38-1/3 (11.70) | 38-1/3 (11.70) | 36 (11) | 38-1/4 (11.60) | ~Area~ sq. feet (m².)| 215 (20) | 237 (22) | 323 (30) | 237 (22) | 323 (20) | {machine lbs. (kgs.)| 882 (400) | 661 (300) | 882 (400) | 595 (270) | ... | ~Weight~ { | | | | | | {useful lbs. (kgs.)| ... | ... | ... | ... | ... | ~Motor~ make and h.p.| 60 Rep. | 66 Rep. | 90 Rep. | 95 Rep. | 80 Rep. | {max. mph. (km.)| 69 (110) | 69 (110) | 69 (110) | 78 (125) | 78 (125) | ~Speed~ { | | | | | | {min. mph. (km.)| ... | ... | ... | 62 (100) | 62 (100) | Number built during 1912 | ... | ... | ... | ... | ... | -----------------------------------+------------------+------------------+------------------+------------------+------------------+ Remarks.--Steel construction. Pentagonal and triangular body. Mounted on wheels and skids. The hydro is on one very large central float. [Illustration: _Flight._ UAS] S SANCHEZ BESA. 2 avenue de Villiers, Paris. ----------------------------------+------------------+------------------+------------------+ Model and date. | ~1912.~ | ~1912.~ | ~1913.~ | | Hydro-biplane. | Hydro-biplane. | Hydro-biplane. | | | | (amphibious) | ----------------------------------+------------------+------------------+------------------+ ~Length~ feet (m.)| 34 (10.40) | ... | 32-3/4 (10) | ~Span~ feet (m.)| 54 (16.40) | 55-3/4 (17) | 54-3/4 (16.60) | ~Area~ sq. feet (m².)| 646 (60) | ... | 646 (60) | {àvide lbs. (kgs.)| 1984 (900) | ... | 1102 (500) | ~Weight~ { | | | | {useful lbs. (kgs.)| ... | ... | ... | ~Motor~ h.p.| 100 Renault | 70 Renault | 70 Renault | ~Speed~ max. m.p.h. (km.)| 56 (90) | ... | 50 (80) | ~Endurance~ hrs.| 5 | 5 | 6 | Number built during 1912 | 3 | 1 | 1 | ----------------------------------+------------------+------------------+------------------+ Notes.--Wood and steel construction. Controls.--Ailerons and rear elevators. Floats: The first has two and the second three floats. The 1913 model has a single boat body mounted on wheels. [Illustration: 1913 hydro.] SAVARY. Soc. anonyme des aeroplanes. Robert Savary, 31 rue Dunois, Paris. School: Chartres. Output capacity: 100 to 150 machines a year. -----------------------------------+--------------------+--------------------+-------------------- Model and date. | ~1912.~ | ~1912.~ | ~1913.~ | Biplane. |Military (3-seater.)| Biplane. -----------------------------------+--------------------+--------------------+-------------------- ~Length~ feet (m.)| 36 (11) | 33-1/2 (10.15) | 38-1/2 (11.70) ~Span~ {feet (m.)| 46 (14) | 49 (14.90) | 49-1/4 (15) {feet (m.)| 33 (10) | 37 (11.20) | 33 (10) ~Area~ sq. feet (m².)| 510 (48) | 533 (50) | 550 (52) {machine lbs. (kgs.)| 1132 (600) | ... | 1132 (600) ~Weight~ { | | | {useful lbs. (kgs.)| ... | ... | ... ~Motor~ h.p.| various | 70 Labor | 75 Renault | | | (Gnome or Labor) {max m.p.h. (km.)| 56 (90) | ... | 59 (96) ~Speed~ { | | | {min m.p.h. (km.)| 50 (80) | ... | ... Number built during 1912 | ... | 47 | ... -----------------------------------+--------------------+--------------------+-------------------- Notes.--Wood and steel construction. _Control_: ailerons and rear elevator. Landing gear: wheels and skids. _Special features_: There are 4 rudders in the gap, and 2 tractors, chain driven. Aeroplatte fabric. [Illustration: SAVARY. 1913. UAS] SLOAN. "Bicurve." Sloan & Cie, 17 rue de Louvre, Paris. Works: 9 rue Victor Hugo, Charenton. Flying ground: Port Aviation. Output capacity: small. ------------------------------+------------------+------------------+ Model and date. | ~1912.~ | ~1913.~ | ------------------------------+------------------+------------------+ ~Length~ feet (m.)| 31-1/3 (9.50) | 29 (8.70) | ~Span~ feet (m.)| 42-3/4 (13) | 42-1/2 (12.90) | ~Area~ sq. feet (m²)| 527 (49) | 473 (44) | {machine lbs. (kgs.)| 1100 (500) | 662 (300) | ~Weight~ { | | | {useful lbs. (kgs.)| ... | ... | ~Motor~ h.p.| 100 Gnome | 120 Laviator | ~Speed~ {max. m.p.h. (km.)| 59 (95) | 65 (105) | Number built during 1912 | ... | ... | ------------------------------+------------------+------------------+ Notes.--Wood construction. Wheels and skids landing gear. _Control_: ailerons and rear elevator. [Illustration: Sloan.] SOMMER. Ateliers Roger Sommer, Mouzon, Ardennes. Flying grounds: Douzy, Mourmelon, Vidammé. ~Monoplanes.~ ~Biplanes.~ /-----------------^-----------------\ /-------------------------------------------^------------------------------------------------\ -----------------------------------+------------------+------------------+------------------+------------------+------------------+------------------+------------------ Model and date. | ~E 1912.~ | ~1913.~ | ~K 1912.~ | ~R 1912.~ | ~S 1912.~ | ~L 1912.~ | ~R3 1913.~ | | | Single seater. | 2 or 3-seater | | | 2 or 3-seater -----------------------------------+------------------+------------------+------------------+------------------+------------------+------------------+------------------ ~Length~ feet (m.)| 22 (6.70) | 23 (7) | 39-1/4 (12) | 36 (11) | 31 (9.50) | 29-1/2 (9) | 38-2/3 (11.70) ~Span~ feet (m.)| 28-1/2 (8.70) | 26-1/4 (8) | 39-1/4 (12) | 51 (15.50) | 42 (12.80) | 39-1/4 (12) | 46 (14) ~Area~ sq. feet (m².)| 172 (16) | 172 (16) | 215 (20) | 533 (50) | 350 (32) | ... | 575 (54) {machine lbs. (kgs.)| 595 (270) | 617 (280) | 617 (280) | 992 (450) | 597 (275) | 639 (290) | 882 (400) ~Weight~ { | | | | | | | {useful lbs. (kgs.)| ... | ... | ... | ... | ... | ... | ... ~Motor~ h.p.| 50 Anzani | 50 Gnome | Various | Various | Various | Various | 70 Renault | or Gnome | | | | | | {max. m.p.h. (km.)| 84 (135) | 84 (135) | 61 (98) | 50 (80) | 57 (92) | 56 (90) | 56 (90) ~Speed~ { | | | | | | | {min. m.p.h. (km.)| 67 (108) | 65 (105) | 53 (85) | ... | 53 (84) | ... | ... ~Endurance~ hrs.| 4 | 4 | ... | ... | ... | ... | ... Number built during 1912 | ... | ... | ... | ... | ... | ... | ... -----------------------------------+------------------+------------------+------------------+------------------+------------------+------------------+------------------ Wood and steel construction. Landing: carriage |Wood and steel construction. Landing: wheels and skids. wheels. _Control_: warping and rear elevator. |_Control_: ailerons and front rear elevator. Rectangular body. | -------------------------------------------------------------------------+---------------------------------------------------------------------------------------------- [Illustration: SOMMER. UAS] T TRAIN. E. Train, Buoy, Camp de Chalons (Marne). -----------------------------------+------------------+------------------+------------------+ Model and date. | 1-seater. | 2-seater. | Hydro-mono. | ~Monoplanes.~ | | | | -----------------------------------+------------------+------------------+------------------+ ~Length~ feet (m.)| 26-1/4 (8) | 26-1/4 (8) | 26-1/4 (8) | ~Span~ feet (m.)| 30-3/4 (9.30) | 35 (10.66) | 42-1/2 (12.94) | ~Area~ sq. feet (m².)| 172 (16) | 215 (20) | ... | {machine lbs. (kgs.)| 573 (260) | 617 (280) | ... | ~Weight~ { | | | | {useful lbs. (kgs.)| ... | ... | ... | ~Motor~ h.p.| 30/60 Anzani | 70 Gnome | 80 Gnome | {max. m.p.h. (km.)| 59 (95) | 65 (105) | ... | ~Speed~ { | | | | {min. m.p.h. (km.)| 47 (75) | ... | ... | Number built during 1912 | ... | ... | ... | -----------------------------------+------------------+------------------+------------------+ Notes.--Steel construction. Landing: carriage wheels and skids. _Control_: warping and rear elevator. The hydro has one very large float which extends a considerable distance ahead of the tractor. [Illustration: TRAIN. UAS] TUBAVION. Ponche & Primaud, Long. -----------------------------------+------------------+ Model and date. | Monoplane. | | ~1913.~ | -----------------------------------+------------------+ ~Length~ feet (m.)| 29 (8.85) | ~Span~ feet (m.)| 29-1/2 (9) | ~Area~ sq. feet (m².)| 194 (18) | {machine lbs. (kgs.)| 772 (350) | ~Weight~ { | | {useful lbs. (kgs.)| ... | ~Motor~ h.p.| 70 Gnome | ~Speed~ max. m.p.h. (km.)| 65 (105) | Number built during 1912 | 1 | -----------------------------------+------------------+ Notes.--Tubular steel construction. Landing: wheels and 2 very long skids. Propeller: amidships. [Illustration: TUBAVION. UAS] V VINET. Gaston Vinet, 41-47 quai de Seine, Courbevoie: also 2-8 rue Larnac. Established for automobile work, 1893. Aeroplane output capacity: small. -----------------------------------+--------------------+--------------------+ Model and date. | Type ~D~ | ~1913.~ | | ~1912~ mono. | Mono. | -----------------------------------+--------------------+--------------------+ ~Length~ feet (m.)| 21-1/2 (6.60) | 21 (6.40) | ~Span~ feet (m.)| 28-1/2 (8.60) | 28 (8.50) | ~Area~ sq. feet (m².)| 162 (15) | 162 (15) | {machine lbs. (kgs.)| 550 (250) | 440 (200) | ~Weight~ { | | | {useful lbs. (kgs.)| ... | ... | ~Motor~ h.p.| 50 Gnome | 50 Gnome | ~Speed~ max m.p.h. (km.)| 56 (90) | 60 (95) | Number built during 1912 | 6 | ... | -----------------------------------+--------------------+--------------------+ Notes.--Wood construction. Landing wheels and skids. _Control_: warping and rear elevator. Rectangular body. The two types are practically identical. [Illustration: VINET. Type D. UAS] VOISIN. Voisin Aéroplanes, Boulevard Gambetta, Issy le Molineux, (Seine). School: Mourmelon. Capital 1,000,000 francs. The oldest aeroplane firm in the world, founded by the Brothers Voisin in 1905. (See past editions). Latest models are: ----------------------------------+--------------------+--------------------+--------------------+ | Military | | Military | Model and date. | biplane. | Hydro-biplane. | biplane. | | Model ~1912.~ | Model ~1912.~ | Model ~1913.~ | ----------------------------------+--------------------+--------------------+--------------------+ ~Length~ feet (m.)| 37-3/4 (11.50) | 36 (11) | 32-3/4 (10) | ~Span~ feet (m.)| 55-3/4 (17) | 43-1/4 (13.50) | 45-1/3 (13.80) | ~Area~ sq. feet (m².)| 387 (36) | 376 (35) | 398 (37) | {total lbs. (kgs.)| 1367 (620) | 1212 (550) | 1102 (500) | ~Weight~ { | | | | {useful lbs. (kgs.)| 772 (350) | 661 (300) | 794 (360) | ~Motor~ h.p.| 70 Renault | 100 Gnome | 80 Gnome | {max. m.p.h. (km.)| 62 (100) | 62 (100) | 65 (105) | ~Speed~ { | | | | {min. m.p.h. (km.)| ... | ... | ... | Number built during 1912 | 47 | 8 | ... | ----------------------------------+--------------------+--------------------+--------------------+ [Illustration: Canard with floats. _By favour of "Aeronautics," U.S.A._] Z ZODIAC. Société Zodiac, 10 route du Havre, Puteaux _pres_ Paris (Seine). Aero park: St. Cyr l'Ecole _pres_ Versailles. Established 1896. Capital 850,000 francs. -----------------------------------+------------------+ Model and date. | ~S2.~ | | ~1913.~ | -----------------------------------+------------------+ ~Length~ feet (m.)| 38-3/4 (11.75) | {feet (m.)| 49 (15) | ~Span~ { | | {feet (m.)| 36 (11) | ~Area~ sq. feet (m².)| 350 (32) | {machine lbs. (kgs.)| 1010 (460) | ~Weight~ { | | {useful lbs. (kgs.)| 551 (250) | ~Motor~ h.p.| 50 Gnome | ~Speed~ max. m.p.h. (km.)| 59 (95) | Number built during 1912 | ... | -----------------------------------+------------------+ Notes.--Wood construction. _Control_: Ailerons and 1 rear elevator. Upper planes staggered 30 in advance of lower. Quadrilateral fuselage. Piloted passenger side by side. Landing carriage: 2 wheels and 1 skid. Aeroplatte fabric. The 1912 model was practically the same. [Illustration: ZODIAC. UAS] [Illustration] FRENCH DIRIGIBLES. ~Military.~ ---------------+----------------------+-------------+-------+----------+------+-------------+------------------ | | | | Capacity | | Speed. | Date. | Name. | Make. | Type. | in m³. | H.P. | m.p.h. (K) | Notes. ---------------+----------------------+-------------+-------+----------+------+-------------+------------------ 1909 | ~LIBERTÉ~ | Lebaudy | s.r. | 4800 | 120 | 28 (45) | | | | | | | | 1910 | ~COL. RENARD~ | Astra | n.r. | 4100 | 100 | 30 (50) | | | | | | | | 1911 | ~ADJUTANT REAU~ | Astra 10 | n.r. | 8950 | 220 | 32 (53) | " | ~LIEUT. CHAURE~ | Astra 11 | n.r. | 8950 | 220 | 32 (53) | " | ~ADJ. VINCENNOT~ | C. Bayard 4 | n.r. | 7500 | 75 | 29 (48) | " | ~SELLE DE BEAUCHAMP~ | Lebaudy | s.r. | 8000 | 75 | 30 (50) | " | ~CAPT. MARÉCHAL~ | Lebaudy | s.r. | 7500 | 160 | | " | ~LE TEMPS~ | Zodiac 9 | n.r. | 2500 | 75 | 29 (48) | " | ~CAPT. FERBER~ | Zodiac 10 | n.r. | 6000 | 180 | 33 (54) | " | ~COMDT. COUTELLE~ | Zodiac 11 | n.r. | 9000 | 380 | 37 (60) | | | | | | | | 1912 | ~SPIESS~ | Zodiac 12 | r. | 11000 | 400 | 40 (65) | " | ~FLEURUS~ | C. Bayard 5 | n.r. | 6500 | 150 | 36 (58) | " | ~ECLAIREUR CONTÉ~ | Astra 12 | n.r. | 6640 | 75 | 28 (46) | " | ~DUPUY DE LÔME~ | C. Bayard 6 | n.r. | 9700 | 244 | 35-1/2 (58) | | | | | | | | _Building_ | _A_ | Astra |} | | | | | _B_ | C. Bayard 7 |} | | | | | _C_ | Lebaudy |} | 17000 | 1000 | 43-1/2 (70) | | _D_ | Zodiac 13 |} ? | | | | | | |} | | | | _Pro._ | _7 new_ 20,000 c.m. | |} | | | | ---------------+----------------------+-------------+-------+----------+------+-------------+------------------ ~Military sheds~ at Belfert, Epinal, Maubenge, Reims, Toul, Verdun (2). --Total 7. During the year 1912 the principal work done was as follows:-- -----------------+------------+---------------------+------------ | Hours out. | Distance travelled. | Gas used. Name. | | m. (km.) | m³ -----------------+------------+---------------------+------------ _C. Ferber_ | 152 | 3540 (5900) | 45,500 _Adj. Reau_ | 105-1/2 | 2310 (3845) | 81,000 _Dupuy de Lôme_ | 100 | 2655 (4424) | 66,500 _Adj. Vincennot_ | 55 | 1340 (2235) | 50,000 _Le Temps_ | 23 | 440 (700) | 9,000 _Fleurus_ | 3-3/4 | 100 (159) | 19,000 -----------------+------------+---------------------+------------ ~Army Dirigible Pilots.~ Airault, F. Balny D'Avricourt Baudry, A. Bayard de Mendoca Clerget, P. Cohen, A. Herbster, M. Hirschaner, Col. Juchmès, G. Mugnier, Capt. Noe, Martial Périssé, Y. Renard, Col. P. Roussel, A. Schelcher, A. Note.--There are no dirigibles attached to the Navy. ~Private.~ ------+--------------------+----------+-------+----------+------+-----------------+---------------- | | | | Capacity | | Speed. | Date. | Name. | Make. | Type. | in m³. | H.P. | m.p.h. (k.p.h.) | Remarks. ------+--------------------+----------+-------+----------+------+-----------------+---------------- 1909 | ~ASTRA~ | Astra 7 | n.r. | 4475 | 100 | 27 (43) | | | | | | | | 1909 | ~ZODIAC III~ | Zodiac 3 | n.r. | 1400 | 40 | 28 (45) | | | | | | | | 1911 | ~ASTRA TORRES~ | Astra | n.r. | 1930 | 55 | 34 (56) | | | | | | | | 1912 | ~TRANSAERIENNE II~ | Astra 13 | n.r. | 9000 | 350 | 34 (56) | ------+--------------------+----------+-------+----------+------+-----------------+---------------- ~Private sheds~ at Chalons-s-Marre, Issy (2), Lamotte-Breuil, Meaux, Melun, Mousson, Reims, Pau, St. Cyr (2).--Total 11. 32 sheds are building or projected by the National Aviation Committee. ~Private Dirigible Pilots.~ Capazza, Louis Godart, Louis Julliott, Henri Kapferer, Henri La Vaulx (de) Compte Santo-Dumont, Albert Surcouf, Edward =ASTRA CLASS.= Astra Societe de Constructions Aeronautique, 13, Rue Couchot, and 121, Rue de Bellevue, Billancourt. This Society was founded by Surcouf for the production of ordinary balloons. The first dirigible work was building part of the old _Lebaudy_ in 1903, followed in 1906 by the _Ville de Paris_. The total number of dirigibles of this type completed by the end of 1912 stood at 14, one very large dirigible in hand for the French Army, and one small one for the British Navy, and another for the Russian Army. Owing to changes in names, or owing to two names getting supplied to one ship, confusion frequently exists as to the names of the Astra dirigibles. The correct list is as follows:-- 1. Part of the LEBAUDY 1903 2. VILLE DE PARIS 1906 3. VILLE DE BORDEAUX 1908 4. VILLE DE NANCY 1909 5. Russian Military dirigible, KOMMISSIONNY,} originally known as CLEMENT-BAYARD I} 1909 6. COLONEL RENARD 1909 7. ASTRA-TRANSAERIENNE-VILLE DE PAU-VILLE} DE LUCERNE[C] } 1909 8. ESPANA (Spanish Military) 1909 9. VILLE DE BRUXELLES 1910 10. LIEUT. CHAURE (French Military) 1911 11. ADJUTANT RÉAU (French Military) 1911 12. ECLAIREUR CONTÉ (French Military) 1912 13. TRANSAERIENNE II 1912 14. ASTRA-TORRES I 1911 The general features of the _Astra_ class are: Non-rigid, weights distributed by means of a long girder hung under the gas bags, a long nacelle, and inflated stabilising shapes at the rear end of the balloon. The _Astra-Torres_ type are also non-rigid, but of trefoil section with a short nacelle. The Compagnie Generale Transaerienne was first established in 1909 with _Transaerienne I_, and during the summers 1909, 1910 and 1911, this ship made a total of 273 ascents, carried 2590 passengers, and voyaged 7990 kilometres. The Astra firm has dirigible hangers at Issy, Pau, Meaux, and Reims. Its constructional capacity is sufficient to build six dirigibles at any one time. "ASTRA I-TRANSAERIEN-VILLE DE PAU-VILLE DE LUCERNE" (1909). [Illustration] ~Maximum length,~ 197 feet (60 m.) ~maximum diameter,~ 40 feet (12.20 m.) ~volume,~ 158,000 c. feet (4,475 m³.) ~Total lift.~--Just over 7 tons=15,763 lbs. (7,150 kgs.) ~Useful lift,~ lbs. ( kgs.) ~Gas bags.~--Continental rubbered fabric, yellow. ~Motor.~--One 90-100 C. Bayard. ~Speed.~--27 m.p.h. (43 k.p.h.) ~Propellers.~--One. [Illustration: SIDE ELEVATION] COLONEL RENARD. Military (1909). [Illustration] ~Maximum length,~ 213 feet (65 m.) ~maximum diameter,~ 35 feet (10.50 m.) ~volume,~ 145,000 c. feet (4,200 m³.) ~Total lift.~--9,921 lbs. (4,500 kgs.)=about 4-1/2 tons. ~Gas bags.~--Yellow coloured rubber proofed Continental fabric. ~Motor.~--One 110 h.p. 4-cylinder Panhard. ~Speed.~--29 m.p.h. ~Propellers.~--1, at the front end of the car. "Integrale." ~Steering.~--Elevators. Remarks.--The two side stabilising shapes are duplicated, as they were in the _Ville de Paris_. A webbing stretched on steel tubes is introduced between the inner edges of the 4 main stabilising shapes to provide extra stabilising surface. [Illustration: COLONEL RENARD. UDS Note.--An elevator aft has since been added.] Improved _Col. Renard's_ are:-- LIEUT. CHAURE. Military (1911). ADJUTANT RÉAU. Military (1911) TRANSAERIEN II (1911). Particulars of these are as follows:-- --------------------+-----------------------------+----------------------------+----------------------------- | _Lieut. Chaure._ | _Adjutant Reau._ | _Transaerien II._ --------------------+-----------------------------+----------------------------+----------------------------- ~Length~ | 275-1/2 feet (83.8 m.) | 285 feet (86.78 m.) | 250 feet (76.25 m.) ~Diameter~ | 46 feet (14 m.) | 46 feet (14 m.) | 46 feet (14 m.) ~Volume~ | 312,550 c. ft. (8,850 m³.) | 314,000 c. ft. (8950 m³.) | 318,000 c. ft. (9,000 m³.) ~Motors~ | 2 Panhard, each 110 h.p. | 2 Brasier, each 110 h.p. | 2 of 175 h.p. each ~Speed~ (p.h.) | 32 m. (53 km.) | 32 m. (53 km.) | 34 m. (56 km.) --------------------+-----------------------------+----------------------------+----------------------------- Notes.--All have 1 propeller forward of 6 m. diameter, and 2 aft of 3.70 m. The _Lieut. Chaure's_ empeunage is by ballonets; in the other two a cellular system and automatic stabilisation are the special feature. +----------------------------------------------------------+ | | | Appearance practically the same as for _Colonel Renard_. | | | +----------------------------------------------------------+ ÉCLAIREUR CONTÉ. Military. (1912) Nominal volume, 6,500 m³. [Illustration] ~Length,~ 213 feet (65 m.) ~diameter,~ 46 feet (14 m.) ~volume,~ 234,500 c. feet (6,640 m³.) ~Ballonets.~--Volume, 71,770 c. feet (2,032 m³) empeunage: cellular. ~Nacelle.~--Length, 115 feet (35 m.) Breadth, 5-1/2 feet (1.60 m.) Height _about_ 6 feet (2-1.50 m.) ~Motor.~--2 Chenu, 80 h.p. Hele-Shaw clutch. ~Speed.~--_About_ 28 m.p.h. (43-45 km.p.h.) ~Propellers.~--2 central aft, each of 4 m. (13 feet) diameter. 650 r.p.m. ~Empeunage.~--Cellular, Stabilisation automatic. Notes.--In this type the usual Astra style, rear of gas bag, is entirely done away with. Surface of each elevator is 18m², of the rudder 33m². There are 2 petrol reservoirs, each of 180 litre capacity. ~Weights.~ lbs. (kgs.) Crew 838 (380) Details 1367 (620) Tools, etc. 220 (100) "Lest d'altitude" 2205 (1000) " securité 661 (300) ---- ------ Total 5291 (2400) ASTRA-TORRES I. [Illustration] ~Length,~ 157 feet (47.72 m.) ~diameter,~ 33 feet (10 m.) ~volume,~ 68,150 c. feet (1,930 m³.) ~Ballonets.~--Volume, 11,300 c. feet (320 m³.) ~Nacelle.~--Length, 18 feet (5.50 m.) Breadth, 5 feet (1.50 m.) Height, 6-1/2 feet (2 m.) ~Useful lift.~--1,219 lbs. (553 kgs.) ~Motor.~--1 Chenu, 55 h.p., at 1,380 r.p.m. Clutch, Ruban. ~Speed.~--31 m.p.h. (50 km.) ~Endurance~ _about_ 5 hours. ~Propeller.~--1 in rear of nacelle. Diameter, 14-3/4 feet (4.50 m.) Notes.--The special feature of this type is that it is constructed in three lobes, two below and one above. This particular ship is merely experimental, and is known as a "Vedette." Three models of it are to be obtained, (1) this 55 h.p. of 1,930 m³. volume. (2) a 75 h.p. of 2,000 m³. nominal volume. (3) a 110 h.p. of from 3,000-3,500 m³. volume. This latter is designed to have two propellers instead of one. Larger editions of the type are also projected as follows:-- ~"Scouts:"~ 4500-6300 m³. of 200 h.p. (2 motors.) ~"Transaeriens:"~ 7,000-8,000 m³. of 400 h.p. (2 motors.) ~"Dreadnoughts:"~ 12,000 m³. or so, of 750 h.p. (4 motors.) [Illustration: UDS] =CLEMENT-BAYARD CLASS.= Usines Clement-Bayard, 33, quai Michelet, Levallois-Perret (Seine). These dirigibles closely resemble the _Astra_ class in some main particulars; but (excepting _I_) differ from them in the sharp sterns and absence of stabilisers on stern. The ships of this class are:-- 1 CLEMENT-BAYARD I (Kommissionny) Russian Military 2 " II British Military (wrecked) 3 " 4 " IV (_Adjutant Vincennot_) French Military 5 " V (_Fleurus_) " 6 " VI Private 7 " VII French Military (_building_), To be of 17,000 m³. ADJUTANT VINCENNOT. Military. (1911.) (Clement-Bayard IV.) [Illustration] ~Maximum length,~ 251 feet (76.50 m.) ~maximum diameter,~ 43 feet (13.22 m.) ~volume,~ 7,500 m³. ~Total lift.~--Nearly 8 tons (8,000 kgs.) ~Useful lift,~ 2-3/4 tons (2717 kgs.) ~Gasbags.~--Continental rubbered fabric. Weight, 380 grammes per m². Strength 1,000 kg. per metre. Leakage under 10 litres per m² per 24 hours. ~Motors.~--2 Clement motors, 4-cylinder, of 130 h.p., each placed on either side of the motor space. ~Speed.~--35 m.p.h. (56 km.) ~Propellers.~--2 Chauvière. Diameter, 19-3/4 feet (6 m.) Placed one on either side of the motors, well above the level. ~Steering.~--Vertical steering by means of a treble horizontal rudder over the rear end of the car. Horizontal steering by means of 2 vertical rudders placed one on each side of the rear horizontal rudder. Remarks.--The feature of this _C.B._ type, which distinguishes it from the Astra ships of about the same size, is the arrangement of the propellers and the use of a 2 speed gear in connection with these. Normally each motor drives its own propeller through two sets of gearing connected by a Cardan shaft. On stopping one motor, the stopped motor is unclutched from its propeller shaft, which is then connected up by chain drive to the opposite shaft. The running motor is then put on to a "low gear," so that it can make the revolutions necessary for obtaining full power, while the propellers run slower than before. The ratio of "low gear" to "high" is 2 to 1, so that a single motor will be running under its best conditions when well throttled down. A sister, _C. Bayard II_ was sold to the British Army, and wrecked or dismantled, 1911. LIST OF WEIGHTS. kgs. Gas bag 1,350 Valves (4) 45 Suspension 195 Girder (complete with fittings) Bow portion (6 m. long.) 128 Engine room (2.5 m.) 1,390 Bridge and passenger space (12 m.) 957 After part (18 m.) 182 Raised tail (4.5 m.) 63 2 Propeller brackets 378 2 Propellers 230 Rudders 150 Water 140 Trail ropes 75 ----- Total 5,283 Lift 8,000 ----- Balance, for ballast fuel, oil, crew 2,717 FLEURUS. Military. (C.B. V.) (1912.) C. BAYARD VI. (Private.) (1913.) These two are slightly smaller sisters of the _Adjutant Vincennot_. =LEBAUDY CLASS.= Ateliers Lebaudy Frères, Moisson, par La Roche-Guyon (Seine-et-Oise). ~DISTINCTIVE CHARACTERISTICS:~ The cars are short and suspended from a long keel which is suspended close up to the gas bag, and is mostly covered in with fireproof canvas. The rear end of the keel is expanded into fixed vertical and horizontal fins, and carries a vertical and a horizontal rudder. The rear end of the gas bag is fitted with thin fixed planes (compare with the pear shaped or tubular fins of the "Astra" class). The cars are provided underneath with an extraordinarily strong conical structure, which takes the shock of striking the ground and distributes it over the whole car. Aeroplanes are now fitted, one each side of the keel, well forward. Ships of this class which have been built:-- ~LEBAUDY I~ ~French Military Airship.~ Rebuilt 1909 into _Lebaudy II_. } now 1. ~LEBAUDY II~ " " Original _Lebaudy I_ rebuilt. ~Known as~ _Le Jaune_.} discarded 2. ~PATRIE~ Lost in a storm. 3. ~REPUBLIQUE~ ~French Military Airship.~ Wrecked Autumn, 1909. 4. ~LA RUSSIE~ ~Sold to Russian Government.~ Now _Lebed_. 5. ~LIBERTÉ~ ~French Military Airship.~ 6. ~CAPITAINE MARECHAL~ " " 7. ~"MORNING POST"~ ~British Military.~ (_Lebaudy III._) Wrecked 1911 8. ~LIEUT. SELLE DE BEAUCHAMP.~ ~French Military Airship.~ 9. New ship of 17,000 m³ building. " " To Lebaudy designs:-- ~ONE~ ~Austrian Military Airship.~ ----------------------------------+------------------+------------------+------------------+------------------ | | ~CAPITAINE~ | ~SELLE DE~ | New ship. Name | ~LIBERTÉ~ | ~MARÉCHAL.~ |~BEAUCHAMP.~ | _Building._ Date | ~1909.~ | ~1911.~ | ~1911.~ | ~1913-14.~ Service | Military. | Military. | Military. | Military. ----------------------------------+------------------+------------------+------------------+------------------ ~Volume~ c. feet (m³)| 4800 | 7500 | 8000 | 17,000 ~Length~ feet (m.)| 220 (67) | 279 (85) | 292 (89) | ~Diameter~ feet (m.)| 35-1/2 (10.80) | 42 (12.80) | 48 (14.00) | {fabric | Lebaudy | Lebaudy | Lebaudy | ~Gasbags~ { | | | | {ballonets | 1 | ... | ... | {total tons| 4-1/2 | ... | 9 | ~Lift~ { | | | | {useful tons| ... | ... | ... | ~Motors~ h.p.| 1--135 Panhard | 2--80 Panhard | 2--80 Panhard | {number | 2 wood | 2 wood | 2 wood | ~Propellers~ {blades | 2 | 2 | 2 | {diam. feet (m.)| ... | 16-1/2 (5) | 16-1/2 (5) | ~Speed~ max. m.p.h. (km.)| 31 (50) | 28 (45) | 28 (45) | ~Endurance~ hrs.| ... | ... | ... | ~Complement~ | ... | ... | 5 | ----------------------------------+------------------+------------------+------------------+------------------ [Illustration] [Illustration: LIBERTE.] [Illustration] =ZODIAC CLASS.= Société française de ballons dirigeables et d'aviation, Zodiac, 10 route du Havre, Puteaux (Seine). These dirigibles were intended primarily for private pleasure purposes. Consequently they are designed to fly when filled with coal gas if necessary. Every effort is made to render them easily transportable; the long girder frame by which the weight is distributed is made to take to pieces. It is held in France that numbers of this class of vessel would form an invaluable asset in time of war, as each could be transported in a single cart, filled with a very few bottles of hydrogen, and when so filled could man[oe]uvre for some 6 hours at a speed which compares favourably with that of the standard types. When the service of reconnaissance was performed, the vessel could be packed up and sent out of harm's way in an hour, whereas this could scarcely be done with a larger vessel on account of the quantity of hydrogen that would be required if it had to be filled afresh for each service. The mooring of an airship in the open during war requires such an amount of preparation and attention as to be a serious drawback to the alternative plan of keeping such vessels unfilled, while the sending of an airship back to its distant shed on each occasion means doubling the work that the ship is called upon to perform. Ships of class are:-- 1. ZODIAC I (_Petit Journal_) 2. " II (_De la Vaulx_) 3 " III 4 " IV Dutch Military 5. " V South American (private) 6. " VI Sold to United States 7 " VII Sold to Russian Army 8. " VIII " " 9. " IX (_Le Temps_) French Army 10. " X (_Capitaine Ferber_) " 11. " XI (_Commandant Coutelle_) " 12. " XII (_Spiess_) " (rigid) ZODIAC III. [Illustration] ~Maximum length,~ 134 feet (40.8 m.) ~maximum diameter,~ 28 feet (8.5 m.) ~volume,~ 1,400 m³. ~Total lift.~--1-1/2 tons (1,540 kgs.) ~Useful lift,~ lbs. ( kgs.) ~Gas bags.~--Light continental rubbered fabric. ~Motor.~--Ballot, 4-cylinder, 40-45 h.p., 1,200 r.p.m. ~Speed.~-- m.p.h. (45 km.p.h.) ~Propellers.~--Driven at 600 r.p.m. Integral type, 12-1/4 feet (3.75 m.) in diameter. Pitch, 6-1/2 feet (2 m.) in rear of the car. ~Steering.~--Vertical balanced rudder in rear of the vertical fin, under the rear of the gas bag. Double elevator above the fore end of the car. Horizontal fins of material spread on iron frames on either side of the rear end of the car. Remarks.--The car consists of a 130 feet (40 m.) long wooden girder, which can be divided into 4 separate parts of 13 feet (4 m.) each. The suspension is by steel wires fitted with adjusting screws at the lower ends and toggles at the upper ends, by which they connect to the crows' feet which are sewn to the suspension strips. [Illustration: ZODIAC III.] DETAILED WEIGHTS OF _ZODIAC III._ kgs. lbs. Gas bag (_including_ ballonet) 330 727-1/2 Valves 12 26-1/2 Suspension wires and gear 15 33 Tail fins 24 53 Horizontal rudder 10 22 Vertical rudder 10 22 Girder car 168 370-1/4 Motor (_including_ pump, magneto, lubricating gear, etc.) 275 606-1/4 Motor bearer and gear 22 48-1/2 Petrol tank 10 22 Radiator 25 55 Reduction gearing 12 26-1/2 Shafting 15 33 Fan 9 20 Steering gear 5 11 Water 8 17-3/4 Petrol 20 44 Miscellaneous: 4 men 300 661 --- --- Total 1,270 2,800 _about_ Ballast 270 595 ----- ----- Total weight 1,540 Total lift 3,395 LE TEMPS. Military. (_Alias ~ZODIAC IX.) [Illustration] ~Maximum length~, 164 feet (50.25 m.) ~maximum diameter~, 29-1/2 feet (9 m.) ~volume~, 81,250 cubic feet (2,300 m³.) ~Total lift.~-- ~Gas bag, etc.~--2 ballonets, each of 257 m³. ~Motor~.--Dansette-Gillet. 60 h.p. ~Propellers~.--2, chain driven, one on either side of car. ~Speed.~-- ~Steering.~--Elevator in _nacelle_ amidships. Rudder aft. Remarks.-- [Illustration: LE TEMPS. UDS.] CAPITAINE FERBER. Military. (_Alias ~ZODIAC X.) ~Maximum length,~ 249-1/3 feet (76 m.) ~maximum diameter,~ 40-1/2 feet (12.36 m.) ~volume,~ 6,000 m³. This ship has 2 ballonets of 650 m³. each, and a car 35×13×2 m., made up of 5 sections. 2 ~motors~. Dansette-Gillette, 90 h.p., each actuating 2 propellers (4-bladed), geared to 500 r.p.m. Carries petrol for 15 hours work. Completed 1911. [Illustration: _Photo, Branger._] [Illustration: CAPITAINE FERBER. UDS.] COMMANDANT COUTELLE. Military. (ZODIAC XI.) +-------------------------------+ | | | (Enlarged _Captaine Ferber_.) | | _Building._ | | | +-------------------------------+ ~Maximum length,~ 292 feet (89 m.) ~maximum diameter,~ 46 feet (14 m.) ~volume,~ 9,000 m³. ~Gas bags, etc.~--2 ballonnets, each 45,900 c. feet (1,300 m³.) ~Nacelle.~--Nickel steel in 5 sections. Length, 131-1/4 (40 m.) Width, 4-1/2 feet (1.30 m.) Hung 16-1/2 feet (5 m.) below the balloon. Pilot in centre. Carries a total crew of six, petrol and oil for 15 hours' continuous work at full power. ~Motors.~--2, each of 190 h.p.=total of 380 h.p. Placed one at either end of the nacelle. ~Propellers.~--4, of 15 feet (4.50 m.) diameter. Two geared to each motor to half engine speed. ~Speed~ (expected).--37 m.p.h. (60 k.p.h.) ZODIAC XII. Rigid. Military. (SPIESS.) [Illustration: Spiess. _Building._ _Photo, Branger._] ~Maximum length,~ 341 feet (104 m.) ~maximum diameter,~ 42-3/4 feet (13 m.) ~volume,~ 11,000 m³. ~Gas bags.~--Sections 11. Number of cylindrical sections 8. Number of sides to polygon 14. ~Motors.~--Two 6-cylinder 200 h.p. in each nacelle, each driving 2 propellers of 15 feet (4.50 m.) diameter. ~Speed.~ (expected)--40 m.p.h. (65 k.p.h.) [Illustration] GERMAN. (By our special German editor.) ~Aerial Journals:--~ _Deutsche Luftfahrer Zeitschrift fur Luftschffahr_ Berlin, W. (Fortnightly). _Allgemeine Automobil Zeitung_, Berlin (Weekly). _Automobil Welt_, Berlin (Thrice Weekly). _Das Deutsche Auto_, Munich (Weekly). _Die Luftflotte_, Berlin (Monthly). _Internationale Revue für Autowesen & Aviatik_, Leipzig (Fortnightly). _Flugsport_, Frankfurt (Fortnightly). _Motor_, Berlin (Monthly). _Der Motorwagen_, Berlin (Thrice Monthly). _Monatshefte der Reichsfliegerstiftung_, Charlottenburg (Monthly). _Zeitschrift für Flugtechnik & Motorluftschiffahrt,_ Berlin (Fortnightly). ~Private Flying Grounds~ (Military see further on):-- ~Adlershof,~ Teil des Flugfeldes Johannisthal (_Wright_ School). ~Bork,~ Post Brück in der Mark (_Mars_ School). ~Burg bei Magdeburg~ (_Schulze_ School). ~Darmstadt~ (Truppenübungsplatz). ~Dotzheim bei Wiesbaden.~ ~Frankfurt a.M.~ (_August Euler_). ~Fühlungen bei Köln~ (Kölner Club für Flugsport). ~Garching b. München~ (_Hoffman-Harlan_). ~Griesheim b. Frankfurt a.M.~ (Frankfurter Flugsport-Club & Flugtechn. Verein). ~Habsheim b. Mülhausen i.E.~ (_Aviatik_). ~Hainberg b. Nürnberg~ (Flugtechn. Ges. Nürnberg-Fürth). ~Hamburg~ (_Grade_). ~Holten. Niederrh. Verein f.L.~ (_Hilsmann_). ~Johannisthal b. Berlin~ Flugschule _Albatros, Dorner, Harlan, Fokker, Luftverkehrs-ges. m.b.H., _Rumpler & Wright_. ~Kitzingen in Bayern,~ 1911 (Hildebrand & Schroth). ~Lindenthal b. Leipzig.~ (School for Deutschen Flugzengwerke). ~Loddenheide b. Münster.~ ~Meerheimb b. Köln.~ ~Milbertshofen b. München~ (Dr. Wittenstein). ~Neuenlande b. Bremen~ (_Müller-Aviatik_, Bremer v.t.L.) ~Niederwalluf,~ 1911 (_Goedecker_). ~Oberwiesenfeld bei München~ (_Gustav Otto_). ~Puchheim b. München.~ ~Reichenberg-Boxdorf b. Dresden.~ ~Schneverdingen~ (_Oertz_). ~Schulzendorf b. Berlin~ (_A.E.G._) ~Strassburg i.E.,~ "Polygon" (E.E.C. _Mathis_). ~Suechteln.~ ~Teltow bei Berlin.~ ~Velten bei Berlin~ (_A.E.G._) ~Wandsbek,~ Exerzierplatz, 1911 (_Rumpler_ und Jordan). ~Weimar~ (_Wright_). ~Wustenbrand b. Chemnitz~ (Flugtechn. Ges. in Chemnitz). ~Zahlbach b. Mainz~ (School for Aut. & Flugtechnik). ~Aerial Societies:--~ Aachener V. f. L. Aix la Chapelle. Aero Club (Imperial), 3, Nollenderfplatz, Berlin. Sec.: H. Von Frankenberg und Ludwigsdorf. Akademie für Aviatik, Munich. Allgemeiner Deutscher Automobil Club, Munich. Anhaltischer V. f. L. (E. U.) M. Antoineatten str. 22a, Dessau. Augsburger Verein für Luftschiffahrt, Augsburg. Automobil-und Flugtechnische-Gesellschaft (E. V.) Nurnberger Platz 5, Haupyverein Berlin, Hochster Str. 1, Bezirksverein Frankfurt a. M, Neuer Wall 44, II, Hamburg. Bayerischer A. K. Munich. Berliner V. f. L., Berlin. Bilterfeldt V. f. L., Bilterfeld. Braunschweigische V. f. L. Breisgau V. f. L., Freiburg. Bremer V. f. L. (E. V.) N. W., Obernstr, 52/54 I, Bremen. Bromberger V. f. L. (E. V.) O, Gasanstalt, Bromberg, Stadt. Chemnitzner V. f. L. Deutsche Touring Club, Munich. Deutscher Luftflotten Verein, Mannheim. Dusseldorfer Luftdahrer-Klub (E. V.) W. Dusseldorf, Breite Str. 25, I. Erfurter V. f. L. (E. V.) M. Dalversweg 24, Erfurt. Flugverein Neustadt a. d. Haardt, S. W., Neustadt, I. Flugzeugkonvention des V. D. M. L., Potsdamer Str. 121 H, III, Berlin W. Frankfürter Flugsport-Club (E. V.) Neue Mainzer Str. 76, Frankfurt a. M. Frankfurter Flugtechn, Verein (E. V.) Bahnhofplatz 8, Frankfurt a. M. Frankfurter V. f. L. (E. V.) S. W. Kettenhofweg 136, Frankfurt, a. M. Frankischer V. f. L. (E. V.) S. Kurschnerhof 6, Wursburg. Hamburger V. f. L. (E. V.) N. W., 36, Colonnaden 17-19, Hamburg. Hannoverscher V. f. L. (E. V.) N. W., Lortzingstr. 6, Hannover. Hereforder Verein fur Lufthahrt, Bahnhofplatz, Alfermann, Herford. Hildesheimer V. f. L., Hilkesheim, Lucienvorder str. 22. Kaiserlicher Aero-Club, K. Nollendorfplatz 3, Berlin W. Kaiserlicher Automobil-Club, K, 9 Leipzigerplatz 16, Berlin W. Karlsruher Luftfahrt-Verein (E. V.) S. W., Bachstr, 28, Karlsruhe. Kolner Club, f. L. (E. V.) W. Bischofsgartenstr. 22, Koln. Koniglich Bayerischer Automobil-Club, B. Brienner str. 5 I, Munchen. Koniglicher Sachsischer V. f. L. (E. V.) Sa, Ferdinandstr. I, Dresden. Kurhessischer V. f. L. (E. V.) S. W., Physikalisches Institut, Marburg ad Lahn; Cassel Sektion, Kolnische str. 84, Cassel. Leipziger V. f. L. (E. V.) Sa, Markt 1, Leipzig. Lubecker V. f. L. (E. V.) N. W., Israeldorfer Allee 13a, Lubeck. Luftshrverein Gotha (fruther Reichsflugverein Gotha), Gotha, I. Luftfahrtverein Touring-Club, Pranner str. 24, I. Munchen. Luftschiffahrt-Verein Munster fur Munster und das Munsterland (E. V.) N. W., Munster i. W, Klosterstr. 31-32. Magdeburger V. f. L. (E. V.) M, Wetterwarte, Bahnhofstr. 17, Magdeburg. Mannheimer V. f. L. "Zahringen" (E. V.) S. W., 7-8 Hansa-Haus, Mannheim. Mecklenburgerischer Aero-Club, Kaiser-Wilhelm-Str. 85, II, I, Schwerin i. M. Mindener Verein fur Luftfahrt, N. W., Grosser Domhof 1, L, Minden i. W. Mitterheinischer V. f. L., S. W., Weisenauer, Str. 15, Mainz. Munchener V. f. L. (E. V.) Residentzstr. 27 III, Munchen. Niederrheinischer V. f. L. (E. V.) Wilhemstr. 11, Bonn, Wupperthal Sektion, Hauptfeuerwache, Barmen; Essen Sektion, Bachstr. 21, Essen-Ruhr; Bonn Sektion, Wilhelmstr. 11, Bonn. Niedersachachsischer V. f. L. (E. V.) Hildesheimer Bank, Filiale Gottingen, Gottingen. Niederschlesisch-Markischer Verein fur Luftfahrt, Grunberg i. Schl, I. Nordmark-Verein fur Motorluftfahrt (E. V.) Dusternbrooker Weg 38, Kiel. Obererzgebirgischer V. f. L. (E. V.) Sa, Geschaftsstelle, Schwarzenberg i. S., Erla im Erzgebirge. Oberrheimischer V. f. L. (E. V.) S. W., Blauwolkengasse 21, Strassburg i. Els. Oberschwabischer V. f. L. (E. V.) S, Promenade 17, Ulm a. D. Osnabrucker V. f. L. (E. V.) N. W., Wittekindstr. 4, Osnabruck. Ostdeutscher V. f. L. (E. V.) O, Courbierestr. 34, II. Graudenz. Ostpreusischer V. f. L. (E. V.) O, Kneiphofische Langgasse 8 I, Konigsberg i. Pr. Pfalzischer Luftfahrtverein Speyer, S. W., Speyer a. Rh. I. Pommerscher V. f. L. (E. V.) Pasewalk (Stettin) F. 65. Posener Luftfahrer-V. (E. V.) O, Posen, Kronprinzenstr, 101a. Reichsflugverein (E. V.) Motztrs, 76, Berlin. Rheinisch-Westfalische Motorluftschaff-Gesellsch. (E. V.) Bachstr. 21, Essen-Ruhr. Saarbrucker Verein fur Luftfahrt, S. W. Saarbrucken, I. Sachsisch-Thuringischer V. f. L. Belvedere-Allee 5, Weimar; Halle a. S. Sektion (E. V.) Halle a. Muhlweg 10 und Poststr. 6; Thuringische Sektion, Staaten; Belvederealle, 5, Weimar. Schlesischer Aero-Club (E. V.) O, Schweidnitzerstr. 16-18 Breslau. Schlesischer V. f. L. (E. V.) O, Schweidnitzerstr. 16-18 Breslau. Schleswig-Holstein. Flieger-Club, N. W., Niemannsweg 81b, Kiel. Seeoffizier-Luftclub (S.L.C.W.) N. W., Peterstr. 80 II, Wilhelmshaven. Trierer Club. f. L. (E. V.) W., Nagelstr. 10, Trier. V. D. Luftchiff-Industrieller, Kleiststr. 8, III, Berlin, W. V. D. Motorfahrzeug-Industrieller, Potsdamerstr. 121b, Berlin, W. V. f. Flugwesen in Mannheim, S. W., Lange Rotterstr. 106, I. Mannheim. V. f. L. am Bodensee (E. V.) S. W., Zummsteinstr. 11, Schwedenchanze 3a, Konstanz. V. f. L. Darmstadt, S. W., Darmstadt, I. V. f. L. Gieben, S. W., Seltersweg 56, I., Gieben. V. f. L. Kolmar (Posen), (E. V.) O. Privinzialbank, Kommanditgesellschaft a. A., Kolmar i. Pos. V. f. L. Limbach (Sa, u. Umgegend) (E. V.) Postr. 5, Limbach (Sachsen). V. f. L. in Mainz (E. V.) S. W., Grosse Bleiche 48, Mainz. V. f. L. in Worms, S. W., Worms, I. V. f. L. und Flugtechnik Nurnberg-Furth, Klaragasse 2 I, Nurnberg. V. f. L. in Weimar (E. V.) Erfurter Str. 9, Weimar. Vogtlandischer V. f. L. (E. V.) Sa, Plauen i. V, Furstenstr. 89. Westfalisch-Lippischer Luftfahrverein (E. V.) N. W., Kavalleriestr, Petri, Bielefeld. Westfalish-Markischer Luftfahrer-Verein, Herne, I. Westpreussicher V. f. L. (E. V.) O., Dr. Waldmann, Abte-inng Schiffbau, Technische Hochschule, Danzig-Langfuhr. Wissenschaftliche Gesellschaft fur Flugtechnik, Nollendorfplatz 3, Berlin W. 30. Wurttenbergischer Flugsport-Club, S. Hegelstr. 4b, Stuttgart. Wurtembergischer V. f. L. (E. V.) S. am Salzmannsweg 21, Stuttgart. Zwickauer V. f. L. (E. V.) Sa, Hauptmarkt 20, Zwickau i. S. ~GERMAN MILITARY AVIATION.~ ~Army General.~ The new Army law provides £400,000 (80 million marks) for Army aviation (including dirigibles), in addition to a considerable share of the £4,000,000 which is being spread over a period of five years. The Army aerial force will be commanded by 2 inspector generals. The aviation force is put at 4 batallions. _Headquarters_: Berlin. _Stations_: Aachen, Allenstein, Cologne, Darmstadt, Doebritz, Freiburg, Graudenz, Hannover, Insterburg, Jüterbog, Koenigsberg, Metz, Posen, Strassburg, Zeithain. The scheme will be complete by the end of the year. ~Army Flying Schools.~ ~Diedenhofen.~ ~Doeberitz.~ ~Metz.~ ~Oberwiesenfeld~ bei München (Bavarian). ~Saarburg.~ ~Sperenberg~ bei Jüterbog. ~Army Aeroplanes.~ At the end of 1912 the aeroplane force was as follows:-- Bought in 1911 10 monoplanes (2 Grade, 1 Schultze, 5 Rumpler). 25 biplanes (3 Albatross, 22 Farman type.) Bought in 1912 91 monoplanes (20 Bristol, 1 Dorner, 2 Etrich Taube, 2 Grade, 6 Harlan, 20 Mars, 40 Rumpler Taube). 144 biplanes (50 Albatros, 12 Aviatik, 30 Euler, 10 Otto, 2 L.V.G., 10 Mars, 6 Wrights). ---- Making a total of ~270~ of which number about 200 were war-effectives. For ~1913~ there are ~200~ new aeroplanes building or provided for. Under the new regulations, military machines must comply with the following conditions:-- 1. Must be of entirely German manufacture, with ample and comfortable seating accommodation for pilot and passenger. 2. Design must permit of fitting bomb droppers and photographic apparatus. 3. Speed capabilities must not be less than 90 kilometres (56 m.p.h.) 4. Dimensions must not exceed 49 feet span (14.50 m.), 39 feet long (12 m.), 13 feet high (3.50 m.), and the motor not more than 100 h.p. 5. Minimum endurance, 4 hours. ~Army Aviators.~ Ackermann, Lt. K. Albrecht, Ob-Lt. K. Altrichter, Lt. K. v. Apell, Lt. K. Barends, Lt. von Beaulieu, Ob-Lt. W. Berlin, Ob-Lt. E. Blume, Lt. W. Boeder, Lt. O. Braun, Lt. Busch, Lt. H. v. Buttlar, Lt. W. Canter, Lt. Cipa, T. Coerper, W. Lt. von Detten, Lt. G. Demmel, Lt. M. Dransfield, Lt. E. Eich, H. von Eickstedt, Ob-Lt. V. Erhardt, Ob-Lt, R. (119) von Falkenhayn, Lt. F. E. Graf Finck von Finckenstein, Lt. L. Fisch, Lt. W. (107) von Freyberg-Eisenberg-Allmendingen, Lt. F. E. Funck, Lt. W. Geerdtz, F. H. (133) von Gersdorff, Ob-Lt. E. Geyer, Lt. H. Goebel, Ob-Lt. W. Grade, W. H. St. (20) von Hadeln, Lt. F. v. Hammacher, Lt. (49) von Hammerstein Gesmold, Ob-Lt. F.A. Hantelmann, Ob-Lt. M. von Helldorf, Ob-Lt. v. Hiddessen, F. Lt. (47) Hildebrand, Ob-Lt. F. Hofer, Ob-Lt. W. Höpker, Lt. A. von Jagwitz, Lt. F. Joly, Lt. A. Justi, Lt. K. Kahl, H. Kastner, Lt. H. Keim, Lt. J. (127) Keller, Lt. G. Koch, Lt. W Kohr, Lt. R. Lauer, Lt. R. Lauterbach, Ob-Lt. F. von Lichtenfels, Lt. S. (51) von Liusingen, Lt. L. Ludewig, F. Ob-Lt. Meyer, Lt. W. (136) von Minkwitz, Lt. H. von Mirbach, Lt. K. Mudra, Lt. H. (95) Neumann, Ob-Lt. H. von Obernitz, Ob-Lt. W. Oelsner, Lt. W. von Oertzen, Ob-Lt. J. von Osterroht, Lt. P-H. Petri, Ob-Lt. F. (120) Pfeifer, Lt. L. Pirner, Lt. H. K. von Poser und Gross-Nädlitz, Ob-Lt. F. Püschel, Ob-Lt. K. Rapmund, Lt. M. Reiche, Lt. A. v. Reichenberg-Wolfskeel, Graf. (93) Reinhardt, Lt. S. Reuss, Lt. W. Ritter, Lt. K. (121) Roser, H. H. (83) Schäfer, Ob-Lt. L. v. Scheele, Lt. A. Schlegel, Lt. O. Schneider, Lt. H. Schreyer, F. Schulz, Lt. J. Schwartzkopff, Lt. H. Serno, Lt. E. Sieber, Lt. H. Solmitz, F. Lt. Sommer, Lt. P. Steindorf, H. Steger, O. Lt. von Stoephasius, Lt. M. Striper, Lt. F. Suren, Lt. E. Suren, Lt. G. Suren, Lt. H. Taeufert, Lt. W. v. Tiedemann, Ob-Lt. R. (17) von Trotha, Ob-Lt. Vogt, Lt. v. Wedemeyer, Ob-Lt. E. Wendler, Lt. W. Weyer, Lt. G. Wiegandt, Lt. W. Wilberg, Ob-Lt. H. (26) Wildt, Lt. K. (43) Wirth, Ob-Lt. W. (92) Wulff, Lt. A. Zwickau, Lt. K. ~Navy General.~ The 1913 expenditure on naval aviation (including dirigibles) is £250,000 (50 million marks), plus a portion of the special expenditure. ~Naval Flying Schools.~ ~Holminsel~ b. Danzig. ~Putzig~ b. Danzig. ~Naval Stations.~ ~North Sea.~--Cuxhaven (staff to be 5 officers and 192 under officers and men), Emden and Hamburg. ~Baltic.~--Kiel, Putzig and Konigsberg. ~General Headquarters.~--Berlin. Each station will ultimately consist of one dirigible and a number of hydro-aeroplanes. ~Navy Aeroplanes.~ At the end of 1912 the total effective force was:-- ~4 monoplanes~ (_Rumpler_ hydro.) ~10 biplanes~ (4 _Albatros_ hydro., 2 _Curtiss_ hydro., 4 _Euler_). -- Total ~14~ The _Curtiss_ were purchased towards the end of 1911, all the others in 1912. All are or can be fitted with wireless, range 50 miles. 1913. Others on order, including _Ottos_ on floats (_A.G.O._), of which one was delivered in April. ~Navy Aviators.~ Bertram, Ob-Lt. (123) Coulmann, W. Francke, Ob-Lt. C. (142) Goltz, Kap-Lt. K. von Gorrissen, Lt. (4) Hartmann, R. Ob-Lt. (96) Hering, Kap-Lt. M. Janetzky, Kap-Lt. W. Langfield, Ob-Lt. W. Prinz Heinrich von Preussen (38) Schroeter, Ob-Lt. W. Stemmler, B. ~GERMAN PRIVATE AVIATION.~ To end of March, 1913. ~Private Aeroplanes.~ At end of March, 1913, the number of private aeroplanes in Germany was about 80, of which most were school, etc., machines. Abelmann, Carl Abramowitch, Wasewolod Albers, Wilhelm Alig, Ernst. Arntzen, Orla, Dr. jur. Schirrmeister, Hans Badowski, Ludwig Baierlein, Anton Basser, Gustav Beck, Otto Becker, Reinhold Beese, Frl. Behrend, Adolf Berliner, Rudolf v. Bieber, Harald, Dr. jur. Birkmaier, August Blattmann, Ernst Bohlig, Edmund Bosenius, Rudolf Bossin, Fritz Boutard, Charles Braselmann, Karl Breton, Raymond Arthur Brociner, Marco Brunnhuber, Simon Büchner, Bruno Charlett, Willi Clauberg, Fritz Cremer, Fritz Curdts, Carl De Waal, Bernard Dick, Fritz Donnevert, Willy Dorner, Hermann Dücker, Werner Eberhardt, Alfred Eckardt, Willy Eckelmann, Frank Engelhard, Paul Erblich, Heinz Euler, August Evers, Heinrich Eyring, Raymund (Dr. Huth) Falderbaum, Heinz Faller, Artur Faller, Otto Flégier, Th. v. Fokker, Anthony Fremery, Hemmann Friedrich, Alfred Gasser, Hermann Geiss, Franz Georgi, Johannes v. Gorrissen, Ellery Grade, Hans Griebel, Otto, Leutnant a D. Grulich, Karl Grünberg, Arthur Haas, Heinrich Hansen, Hans Hanuschke, Bruno Hartmann, Alfred Hasenkamp, Emil Häusler, Hugo Heim, Oskar Heirler, Paul Hennig, Alfred Hess, Robert Heydenreich, Fritz Hild, Luc. Hintner, Cornelius Hirrlinger, Albert Hirth, Helmuth Hoff, Wilhelm Hoffmann, Siegfr. Hoos, Josef, Dr. jur. Hormel, Walter Horn, Albin Hoesli, Gordian Ingold, Karl Jablonski, Bruno Jahnow, Reinhold, Leutn. d. Landw. Jänisch, M. Jeannin, Emil Kahnt, Oswald Kammerer, K. F. Ludwig Kaniss, Gustav Kanitz, Willy Karsten, Otto Kaspar, Referendar Katzian, Artemy Keidel, Fridolin Kern, Willy Kiepert, Rudolf Kleinle, Josef Kober, Theodor Köhler, Erich Kohnert, Herbert König, Benno König, Martin Krastel, Heinz, Reimar Krieg, Friedrich Krieger, Karl Krüger, Leutnant a. D. Krüger, Arthur Krumsiek, Wilhelm Kühne, Ernst Herbert Kunze, Ernst Kurtscheid, Nicolaus Ladewig, Heinz. Ladewig, Herbert, Leutnant, Inf.-Regt. Lagler, Fräulein Bozena Laitsch, Felix Laemmlin, Charles Lange, Paul Langer, Bruno Lecomte, Ingenieur Lenk, Willy Lichte, Carl Lie, Christian Lindpaintner, Otto E. Linnekogel, Otto Lissauer, Walter Lochner, Erich Loew, Karl Lübbe, Fluglehrer Manhardt, Alfred Willy Mente, Willy, Oberleutnant a. D. Meybaum, Theodor Michaelis, G. A. Mischewsky, Bernard Mohns, Karl Möhring, Charlotte v. Mossner, Robert, Oberleutnant a. D. Mügge, Wilhelm, Kapitan d. Handelsmarine Müller, B. C. Oscar Müller, Friedrich Müller, Karl Müller, Kurt Munkelt, Kurt Mürau, Georg Netzow, Georg Niemela, Edmund, Leutnant a. D. Noelle, Max Oelerich, Heinrick Oster, Franz Ottenbacher, Ernst Otto, Gustav Paul, Alfred Pentz, Hermann Pietschker, Alfred Placzikowski, Udo von Platen, Horst Plochmann, Ernst Pokristev, Penn, Oberleutnant Poulain, Gabriel Reeb, Alfred Reichhardt, Otto Rentzel, Adolf Rode, Franz de le Roi, Wolfram Roempler, Oskar Rosenstein, Willy Roessler, Fritz Rost, Gottlieb v. Rottenburg, Otto Roever, Hans Rupp, Albert Rütgers, August Schadt, Karl Schäfer, Otto Schakowskoy, Fürstin Eugenie Schall, Karl Schauenburg, Theodor Schendel, Georg Scherff, Mauricio Schiedeck, Hermann v. Schimpf, Ernst, Dr. jur Schirrmeister, Hans Schlatter, Joseph Schlegel, Ernst Schlüter, Fritz Schmidt, Erich Schmidt, Richard Schmigulski, Hans Schöner, Georg Schultze, Gustav Schüpphaus, Heinrich Ernst Schwandt, Paul Schwarz, Erwin Sedlmayer, Gerhard Senge, Paul Seydler, Frank Siewert, Lotherm Steffen, Bruno Steinbeck, Hans Stiefvater, Otto Stöffler, Victor Stoldt Stoephasius, Curt von Strack, Karl Strack, Peter Stüber, Joachim, Leutnant d. R. Suvelack, Josef Thelen, Robert Thiele, Erich Toepfer, Otto Trautwein, Max Treitschke, Friedrich Tybelski, Franz Tweer, Gustav Vollmöller, Hans Wecsler, Rubin Weickert, Julius Artur Weinaug, Ernst Werntgen, Bruno Wertheim, Paul Weyl, Richard Wiencziers, Eugen Wieting, Werner Wirtz, Reinerm Witte, Gustav Wittenstein, Oskar, Dr. Witterstätter, E. W. Wolter, Richard von Zastrow, Alexanderm Note.--Abramowitch was a Russian by birth (killed April, 1913). The following German aviators have been killed:-- +-------------------------------+ | 1896. | | Lilienthal | | | | 1910. | | Haas, Lieut. | | Mente, Lieut. | | Plochmann | | Robl, Thaddeus | | | | 1911. | | Bockmüller | | Bournique ("Pierre Marie") | | Choendel | | Dax | | Englehardt, Kapt. | | Eyring, R. | | Frh. v. Freytag-Loringhoven | | Laemmlin | | Lecomte | | Neumann, Lieut. | | Reeb | | Pietschker | | Schendel, G. | | Stein, Lieut. | | Tachs | | Voss | | | | 1912. | | Alig | | Altrichter | | Beissbarth | | Berger | | Birkymayer | | Buchstätter | | v. Falkenhayn | | Frh. v. Schlichting | | Fischer | | Hamburger | | Hofer | | Hösli | | Junghans | | König | | Kugler | | Lachmann | | Lang | | Libau | | Meyer | | Preusser | | Pochmeyer | | Rheinle | | Rost | | Schmidt | | Schmigulski | | Stille | | Werntgen | | Witte | | | | 1913 | | Held | | Schlegel | +-------------------------------+ GERMAN AEROPLANES. ~A~ ALBATROS. Albatroswerke G.m.b. H, Flugzeugfabr. u. Fliegerschule, Johannisthal bei Berlin. Established 1910. One of the largest constructors in Germany. Capacity: 150 machines a year. [Illustration] ----------------------------------+------------------+------------------+------------------+------------------+------------------ | ~1911-12.~ | ~1912.~ | ~1912-13.~ | | | 2-seat tractor | Military tractor | Military tractor | Hydro. | Mono. | biplane. | biplane. | | | ----------------------------------+------------------+------------------+------------------+------------------+------------------ ~Length~ feet (m.)| 35-1/2 (10.70) | 34-1/2 (10.5) | 42-1/2 (12.8) | ... | ... ~Span~ feet (m.)| 43-2/3 (13.30) | 52-1/2 (16) | 65-3/4 (20) | ... | ... ~Area~ sq. feet (m².)| 430 (40) | 576 (54) | 624 (58.5) | ... | ... {total lbs. (kgs.)| 1058 (480) | 1543 (700) | 1874 (850) | ... | ... ~Weight~ { | | | | | {useful lbs. (kgs.)| 661 (300) | ... | ... | ... | ... ~Motor~ h.p.| 100 Argus | 90 Mercedes or | 120 N.A.G. or | ... | ... | | 100 Argus | Aust. Daimler | | {max. m.p.h. (km.)| 56 (90) | 59 (95) | 46 (75) | ... | ... ~Speed~ { | | | | | {min. m.p.h. (km.)| ... | ... | ... | ... | ... ~Endurance~ hrs.| 6 | 6 | 7-5 | ... | ... Number built during 1912 | about 40 | 70 | 30 | 4 | 2 ----------------------------------+------------------+------------------+------------------+------------------+------------------ Remarks.--In all the upper plane is slightly staggered. In all the control is duplicated. [Illustration: ALBATROS. UAS.] [Illustration: Albatros. Military hydro-biplane.] [Illustration: Albatros. Monoplane.] AVIATIK. Autemobil & Aviatik A.G., Mülhausen i.E. Established 1910. Capacity: 100 a year. [Illustration: 1912 biplane.] ----------------------------------+------------------+------------------+------------------+------------------ | ~1912.~ | ~1912.~ | ~1913.~ | ~1912-13.~ | Monoplane. | Biplane. | Racing biplane. | Hydro-biplane. ----------------------------------+------------------+------------------+------------------+------------------ ~Length~ feet (m.)| 26-1/2 (8) | 36 (11) | 29-1/2 (9) | 36 (11) ~Span~ feet (m.)| 39 (11.80) | 52-1/2 (16) | 52-1/2 (16) | 62-1/3 (19) ~Area~ sq. feet (m².)| 258 (.24) | 517 (48) | 517 (48) | 597 (56) {total lbs. (kgs.)| 1146 (520) | 1323 (600) | 1234 (560) |1653 (750) ~Weight~ { | | | | {useful lbs. (kgs.)| 661 (300) | 882 (400) | 882 (400) | 661 (300) ~Motor~ h.p.| 100 Argus | 100 Argus | 100 Argus | 100 Argus {max. m.p.h. (km.)| 68-1/2 (110) | 56 (90) | 62 (100) | 52 (80) ~Speed~ { | | | | {min. m.p.h. (km.)| ... | ... | ... | ... ~Endurance~ hrs.| 5 | 6-8 | 7-8 | 4-5 Number built during 1912 | 6 | 20 | 4 | 3 ----------------------------------+------------------+------------------+------------------+------------------ Remarks.--The monoplanes are constructed under _Hanriot_ license. [Illustration: 1913 tractor-biplane (racer).] [Illustration: Monoplane.] ~D~ DELFOSSE. Ceased to construct. [Illustration: Dorner] DORNER III. Monoplane. ~Length.~--34-1/2 feet (10.50 m.) ~Span.~--39-1/3 feet (12 m.) ~Surface.~--280 sq. feet (126 m².) ~Weight.~--882 lbs. (400 kgs.) Type II: ~Length.~--32-3/4 feet (10 m.) ~Span.~--38 feet (11.60 m.) ~Surface.~--268-1/2 sq. feet (25 m².) ~Weight.~--661 lbs. (300 kgs.) See _Flugsport_, No. 5, 1911. ~E~ ETRICH. Etrich Fliegerwerke, G.m.b. H, Dittersbach b. Liebau (Schlesien). Capacity: 50 a year. [Illustration] ------------------------------+------------------------------- | ~1913.~ | ~Etrich~ (original) _Taube._ | monoplane. ------------------------------+------------------------------- ~Length~ feet (m.)| 31 (9.5) ~Span~ feet (m.)| 47-1/2 (14.4) ~Area~ sq. feet (m².)| 301 (28) {Total lbs. (kgs.)| 1323 (600) ~Weight~ { | {Useful lbs. (kgs.)| ... ~Motor~ h.p.| 100 Mercedes or Argus { max. m.p.h. (km.)| 71 to 75 (115 to 120) ~Speed~ { | { min. m.p.h. (km.)| ... ~Endurance~ hrs.| 6 ------------------------------+------------------------------- Remarks.-- EULER. August Euler, Frankfurt a.M. In 1908 Euler secured _Voisin_ rights for Germany. In 1910 he took out a patent for a design of his own. In the summer of 1911 he built a successful monoplane, in the autumn of the same year a triplane. Existing models are as follows:-- ----------------------------+------------------+------------------+---------------------- | ~1912.~ | ~1912.~ | | Triplane. | Monoplane. | Military biplane. ----------------------------+------------------+------------------+---------------------- ~Length~ feet (m.)| 23 (7) | | ~Span~ feet (m.)| 23 (7) | | ~Area~ sq. feet (m².)| ... | | {total lbs. (kgs.)| ... | no data | no data ~Weight~ { | | | {useful lbs. (kgs.)| ... | | ~Motor~ h.p.| Gnome | | {max. m.p.h. (km.)| 56 (90) | | ~Speed~ { | | | {min. m.p.h. (km.)| ... | | ~Endurance~ hrs.| 3-4 | | Number built during 1912 | _about_ 70 | of various types | ----------------------------+------------------+------------------+---------------------- [Illustration: Euler. Triplane.] [Illustration: Euler. Monoplane, 1912.] [Illustration: Euler. Military biplane.] ~F~ FOKKER. Monoplanes. Fokker-Aeroplanbau, G. m. b. H., 18 Parkstrasse, Johannisthal bei Berlin. Capacity: 40. ---------------------------------+------------------+------------------+------------------+------------------+--------------------+------------------ | ~1912.~ | ~1912.~ | ~1912-13.~ | ~1912-13.~ | ~1912-13.~ | ~1913.~ | ~A.~ | ~B.~ | ~A.~ | ~B.~ | ~C.~ | Hydro-aeroplane. ---------------------------------+------------------+------------------+------------------+------------------+--------------------+------------------ ~Length~ feet (m.)| 26-1/4 (8) | 26-3/4 (8.25) | 29-1/2 (9) | 29-1/2 (9) | 29-1/2 (9) | 31 (9.50) ~Span~ feet (m.)| 37-3/4 (11.50) | 39-1/3 (12) | 42-3/4 (13.20) | 42-3/4 (13.20) | 42-3/4 (13.20) | 52-1/2 (16.20) ~Area~ sq. feet (m².)| 226 (21) | 242 (22.50) | 280 (26) | 280 (26) | 280 (26) | ... {total lbs. (kgs.)| 838 (380) | 1036 (470) | 970 (440) | 1146 (520) | 1190 (540) | ... ~Weight~ { | | | | | | {useful lbs. (kgs.)| ... | ... | ... | ... | ... | ... ~Motor~ h.p.{| 70 Argus | 100 Argus | 70 Argus | 100 Argus | 70 Renault | 100 Renault {| | | or Dixi | | | or Mercedes {max. m.p.h. (km.)| 56 (90) | 68 (108) | 52 (83) | 60 (96) | 53 (85) | 59 (95) ~Speed~ { | | | | | | {min. m.p.h. (km.)| ... | ... | 43 (70) | ... | ... | ... ~Endurance~ hrs.| 4-6 | 4-6 | 5-8 | 5-8 | 4-6 | 4 Number built during 1912 | 3 | 2 | 6 | 5 | 2 | ... ---------------------------------+------------------+------------------+------------------+------------------+--------------------+------------------ Remarks.--The _Fokker_ is a machine of Dutch origin. (See Dutch). [Illustration: 1912-13 model.] [Illustration: Hydro.] FOHN. This firm ceased to exist January, 1913. ~G~ GRADE. Hans Grade Fliegerwerke, Bork, Post Bruck (Mark). Founded 1910 by H. Grade, who was the first man in Germany to fly with a German machine. During 1911 _Grades_ had a considerable vogue, but since then have not been prominent. [Illustration: 1912 racer.] -----------------------------------+----------------------+----------------------+---------------------- Model and date. | Racer, ~1911.~ | Racer, ~1912.~ | Racer, ~1912.~ | ~C.~ | ~D.~ | ~E.~ -----------------------------------+----------------------+----------------------+---------------------- ~Length~ feet (m.)| 33 (10) | 21 (6.50) | 26-1/4 (8) ~Span~ feet (m.)| 39-1/4 (12) | 34-1/2 (10.50) | 41 (12.50) ~Area~ sq. feet (m².)| 480 (45) | 240 (22) | 360 (33) {machine, lbs. (kgs.)| 375 (170) | 408 (185) | 595 (270) ~Weight~ { | | | {useful lbs. (kgs.)| ... ... | ... ... | ... ... ~Motor~ h.p.| various | ... ... | ... ... ~Speed~ m.p.h. (km.)| 56 (90) | 71 (115) | 71 (115) Number built during 1912 | ? | 1 or 2 | ? -----------------------------------+----------------------+----------------------+---------------------- [Illustration: GRADE. UAS.] GOEDECKER. J. Goedecker, Flugmaschinen-Werke, Niederwalluf a. Rh. Flying School: Flugplatz Grosser Sand bei Mainz. [Illustration: GOEDECKER.] ----------------------------------+------------------+------------------ | ~1912.~ | ~1911.~ | Monoplane | Monoplane | "Sturmvogel." | "Sturmvogel." ----------------------------------+------------------+------------------ ~Length~ feet (m.)| 32-3/4 (10) | 29-1/2 (9) ~Span~ feet (m.)| 47-3/4 (14.5) | 47-3/4 (14.5) ~Area~ sq. feet (m².)| 387 (36) | ... {total lbs. (kgs.)| 992 (459) | 827 (375) ~Weight~ { | | {useful lbs. (kgs.)| ... | ... ~Motor~ h.p.| 100 Dixi | 70 Argus ~Speed~ m.p.h. (km.)| 56 (90) | ... Number built during 1912 | 8 | 2 ----------------------------------+------------------+------------------ ~H~ HANSA-TAUBE. Heinrich Heitmann, Aviatik und Konstructions Werkstätten, Altona. [Illustration] ----------------------------------+----------------------+---------------------- | ~1912.~ | ~1913.~ | Monoplane. | Monoplane. ----------------------------------+----------------------+---------------------- ~Length~ feet (m.)| 24-3/4 (7.5) | 24-3/4 (7.5) ~Span~ feet (m.)| 36-3/4 (11.2) | 36-3/4 (11.2) ~Area~ sq. feet (m².)| 237 (22) | 237 (22) {total lbs. (kgs.)| 617 (280) | 573 (260) ~Weight~ { | | {useful lbs. (kgs.)| ... | ... ~Motor~ h.p.| 75 or 100 Argus | 100 Argus ~Speed~ m.p.h. (km.)| 56 to 62 (95 to 100)| 62 (100) Number built during 1912 | 2 | 2 ----------------------------------+----------------------+---------------------- Remarks.-- HARLAN. Harlan Werke, G. m. b. H., 21 Moltkestrasse, Johannisthal bei Berlin. Established 1909, turned into present Company, 1911. Output capacity about 50 machines a year. [Illustration] ----------------------------+-----------------------+---------------------- | ~1912.~ | ~1912-13.~ | Military monoplane. | Military monoplane. ----------------------------+-----------------------+---------------------- ~Length~ feet (m.)| 26-1/4 (8) | 30 (9.10) ~Span~ feet (m.)| 39-1/3 (12) | 45-1/2 (13.80) ~Area~ sq. feet (m².)| 312 (29) | 312 (29) {total lbs. (kgs.)| ... | 1984 (900) ~Weight~{ | | {useful lbs. (kgs.)| ... | 1323 (600) ~Motor~ h.p.| 100 Argus or Mercedes | 100 Argus ~Speed~ m.p.h. (km.)| 69 (110) | 69 (110) ~Endurance~ hrs.| 7-8 | 7-8 Number built during 1912 | 20 | 15 ----------------------------+-----------------------+---------------------- HANUSCHKE. Bruno Hanuschke, Flugzeugbau, Johannisthal b. Berlin. Capacity: small. [Illustration] -----------------------------+------------------+------------------ | ~1912.~ | ~1913.~ | "Typ populaire" | Typ II. -----------------------------+------------------+------------------ ~Length~ feet (m.)| 24-3/4 (7.50) | 21 (6.50) ~Span~ feet (m.)| 27 (8.25) | 26-1/4 (8) ~Area~ sq. feet (m².)| 183 (17) | 172 (16) {total lbs. (kgs.)| 716 (325) | 1102 (500) ~Weight~ { | | {useful lbs. (kgs.)| 385 (175) | 600 (275) ~Motor~ h.p.| 35 Anzani | 50 Gnome ~Speed~ m.p.h. (km.)| 56 (90) | 62 (100) ~Endurance~ hrs.| 2 | 2 Number built during 1912 | 2 | 2 -----------------------------+------------------+------------------ Remarks.-- ~J~ JATHO. Jatho Flugzeugwerke, G. m. b. H., Stader Chaussee 32, Hannover. Karl Jatho built his first aeroplane in 1899, and has produced machines at intervals ever since. Capacity: small. [Illustration] -----------------------------+------------------ | ~1913.~ -----------------------------+------------------ ~Length~ feet (m.)| 29-1/2 (9) ~Span~ feet (m.)| 49-1/4 (15) ~Area~ sq. feet (m².)| 345 (32) {total lbs. (kgs.)| 2116 (960) ~Weight~ { | {useful lbs. (kgs.)| 992 (450) ~Motor~ h.p.| 100 N.A.G. ~Speed~ m.p.h. (km.)| 75 (120) ~Endurance~ hrs.| 3 Number built during 1912 | 2 -----------------------------+------------------ Remarks.-- JEANNIN. Emile Jeannin, Flugzeugbau, G. m. b. H., Stahltauben & Renneindecker Fabrik, Johannisthal b. Berlin. Capacity: small. [Illustration: 1912 "Taube."] -----------------------------+--------------------+-------------------- | ~1912.~ | ~1913.~ | "Taube" monoplane. | Racing monoplane. -----------------------------+--------------------+-------------------- ~Length~ feet (m.)| 29-1/2 (9) | ... ~Span~ feet (m.)| 42-3/4 (13) | ... ~Area~ sq. feet (m².)| ... | ... {total lbs. (kgs.)| ... | ... ~Weight~ { | | {useful lbs. (kgs.)| ... | ... ~Motor~ h.p.| 100-150 Argus | 150 Argus ~Speed~ m.p.h. (km.)| 68 (110) | 87 (140) ~Endurance~ hrs.| 5-8 | 4-7 Number built during 1912 | 2 | 3 -----------------------------+--------------------+------------------ Remarks.--The 1913 was building only in March. ~K~ KAHNT. Oswald Kahnt, Flugzeugbau, Leipzig. Capacity: small. [Illustration] -----------------------------+------------------ | ~K. F. 1913.~ | "Falke." -----------------------------+------------------ ~Length~ feet (m.)| 27-3/4 (8.50) ~Span~ feet (m.)| 42-3/4 (13) ~Area~ sq. feet (m².)| 291 (27) {total lbs. (kgs.)| ... ~Weight~ { | {useful lbs. (kgs.)| ... ~Motor~ h.p.| 50-70 ~Speed~ m.p.h. (km.)| 62 (100) Number built during 1912 | new firm -----------------------------+------------------ KONDOR. Kondor Flugzeugwerke G. m. b. H., Essen, Ruhr. Fabrik auf dem Flugplatz. Rotthausen. Capacity: 30 or so a year. [Illustration: 1913 model. (1912 same appearance.)] -----------------------------+------------------+------------------ | ~1912.~ | ~1913.~ -----------------------------+------------------+------------------ ~Length~ feet (m.)| 33-3/4 (10.30) | 27 (8.20) ~Span~ feet (m.)| 48-3/4 (14.80) | 46 (14) ~Area~ sq. feet (m².)| 258 (24) | 280 (26) {total lbs. (kgs.)| 1543 (700) | 1328 (600) ~Weight~ { | | {useful lbs. (kgs.)| ... | ... ~Motor~ h.p.| 100 Argus | 100 Argus ~Speed~ m.p.h. (km.)| 65 (105) | 70 (112) Number built during 1912 | 2 | ... -----------------------------+------------------+------------------ Remarks.--Both models torpedo body, on 4 skids. Planes dart ~V~ form. Constructor: J. Suwelack. KÜHLSTEIN. Kühlstein Wagenbau, Karosseriefabrik, Salzufer 4, Charlottenburg. This old-established motor car firm commenced to build aeroplanes in 1911. Capacity: 20 a year. [Illustration: 96 h.p.] -----------------------------+--------------------+-------------------- | ~1912.~ | ~1912.~ | Torpedo monoplane. | Torpedo monoplane. | I. | II. -----------------------------+--------------------+-------------------- ~Length~ feet (m.)| 29-3/4 (9.10) | 27 (8.2) ~Span~ feet (m.)| 40-3/4 (12.4) | 35-1/2 (10.8) ~Area~ sq. feet (m².)| 291 (27) | 215 (20) {total lbs. (kgs.)| 1984 (900) | 2204 (1000) ~Weight~ { | | {useful lbs. (kgs.)| 1322 (600) | 1543 (700) ~Motor~ h.p.| 100 Argus | 96 Mercedes {max. m.p.h. (km.)| ... | ... ~Speed~ { | | {min. m.p.h. (km.)| 84 (135) | 87 (140) ~Endurance~ hrs.| 3 | 3 Number built during 1912 | 2 | 2 -----------------------------+--------------------+-------------------- Remarks.-- ~M~ MARS. Deutsche Flugzeugwerke G. m. b. H., Lindenthal bei Leipzig. Established 1911. This is one of the most important and successful aviation works in Germany. Capacity: from 80 to 100 machines a year. [Illustration: Mars. Monoplane.] -----------------------------+------------------+------------------+------------------ | ~1912-13.~ | ~1912-13.~ | ~1913.~ | Monoplane. | Biplane. | Hydro-aeroplane. -----------------------------+------------------+------------------+------------------ ~Length~ feet (m.)| 31 (9.7) | 31 (9.7) | ~Span~ feet (m.)| 55-1/4 (16.8) | 57 (17.8) | ~Area~ sq. feet (m².)| 376 (35) | 495 (46) | {total lbs. (kgs.)| 1234 (560) | 1434 (650) | ~Weight~ { | | | {useful lbs. (kgs.)| 1808 (820) | 2006 (910) | _Building._ ~Motor~ h.p.| 95 N.A.G. | 95 Mercedes | {max. m.p.h. (km.)| 120 (75) | 115 (71) | ~Speed~ { | | | {min. m.p.h. (km.)| ... | ... | ~Endurance~ hrs.| 5-6 | 4-6 | Number built during 1912 | 6 | 16 | -----------------------------+------------------+------------------+------------------ Remarks.-- [Illustration: Mars. Biplane.] MROZINSKI. Bernard Mrozinski, Berlin-Wilmersdorf. Established 1912. [Illustration] ~Length~, 23 feet (7 m.) ~span~, 32-3/4 feet (10 m.) ~area~, 215 sq. feet (20 m².) ~Weight.~--661 lbs. (300 kgs.) ~Motor.~--20 h.p. Anzani. ~Speed.~--50 m.p.h. (80 km.) Remarks.--One machine only built in 1912. ~O~ OERTZ. Max Oertz, Yachtwerft, Reiherstieg b. Hamburg. Famous yacht builder. Commenced aeroplane construction in 1911. Existing models as below. Capacity about 25 machines a year. [Illustration: 1912-13 model.] -----------------------------+--------------------+-------------------- | ~M 1911-12.~ | ~M 1912-13.~ | Monoplane. | Monoplane. -----------------------------+--------------------+-------------------- ~Length~ feet (m.)| 29-1/2 (9) | 30-1/4 (9.2) ~Span~ feet (m.)| 41-3/4 (12.75) | 41-3/4 (12.75) ~Area~ sq. feet (m².)| 247 (23) | 263 (24.5) {total lbs. (kgs.)| 948 (430) | 1212 (550) ~Weight~ { | | {useful lbs. (kgs.)| ... | ... ~Motor~ h.p.| 70 Gnome | 70 Gnome {max. m.p.h. (km.)| 69 (110) | 75 (120) ~Speed~ { | | {min. m.p.h. (km.)| ... | ... ~Endurance~ hrs.| 3 | 4 Number built during 1912 | 3 | 1 -----------------------------+--------------------+-------------------- OTTO. Gustav Otto, Flugmaschinenwerke, Schleissheimer Str. 135, Munich. Started building in 1911. Present max. capacity about 30 machines a year. [Illustration] ------------------------------+----------------- | ~M 1912.~ | Biplane. ------------------------------+----------------- ~Length~ feet (m.)| ... ~Span~ feet (m.)| ... ~Area~ sq. feet (m².)| ... {total lbs. (kgs.)| ... ~Weight~ { | {useful lbs. (kgs.)| ... ~Motor~ h.p.| 100 A. G. Otto. {max. m.p.h. (km.)| 69 (110) ~Speed~ { | {min. m.p.h. (km.)| ... ~Endurance~ hrs.| 6-8 Number built during 1912 | 6 ------------------------------+------------------ Remarks.--All 1912 machines purchased for German Army. ~P~ PEGA-EMICH. Flugtechnische und mechanische Werke vorm. Pega & Emich, Falterstrasse 13-15, Griesheim, Frankurt-a-M. Commenced building with a 6-decker in 1910. Capacity: small. [Illustration] ----------------------------+-------------------- | ~1913.~ | Buteno monoplane. ----------------------------+-------------------- ~Length~ feet (m.)| 39-1/4 (12) ~Span~ feet (m.)| 46 (14) ~Area~ sq. feet (m².)| 355 (33) {total lbs. (kg.)| 838 (380) ~Weight~ { | {useful lbs. (kg.)| 1102 (500) ~Motor~ h.p.| 70 Argus {max. m.p.h. (km.)| 62 (100) ~Speed~ { | {min. m.p.h. (km.)| ... ~Endurance~ hrs.| 2 Number built during 1912. | ... ----------------------------+-------------------- PIPPART-NOLL. Pippart-Noll-Flugzeugbau, Mannheim. [Illustration] ------------------------------+------------------+------------------+-------------------- | P. N. 1 | P. N. 2. | P. N. 3. Type. | Sporting. | "Uberland" | Military. | ~1912.~ | ~1912.~ | ~1913.~ ------------------------------+------------------+------------------+-------------------- ~Length~ feet (m.)| 31 (9.50) | 28 (8.50) | 28 (8.50 also 7) ~Span~ feet (m.)| 34-1/2 (10.50) | 39-1/3 (12) | 45 (13.70) ~Area~ sq. feet (m².)| 215 (20) | 280 (26) | 300 (28) {machine lbs. (kgs.)| 617 (280) | 838 (380) | 1234 (560) ~Weight~ { | | | {useful lbs. (kgs.)| 330 (150) | 463 (210) | 441 (200) ~Motor~ h.p.| 70 Argus | 70 Argus | 70 Argus {max. m.p.h. (km.)| 59 (95) | 62 (100) | 68 (110) ~Speed~ { | | | {min. m.p.h. (km.)| ... | ... | 50 (80) ~Endurance~ hrs.| ... | ... | ... Number built during 1912 | 1 | 1 | 1 ------------------------------+------------------+------------------+-------------------- ~R~ RUMPLER. E. Rumpler, Luftfahrzeugbau G. m. b. H., Siegfriedstrasse 202, Berlin-Lichtenberg, also Johannisthal b. Berlin. Established 1909 by E. Rumpler and R. Haessner for the construction in Germany of _Etrich_ (see Austria) monoplanes. These now vary considerably from the original _Etrich_. Capacity at present about 200 to 300 machines a year. Standard models are as follows:-- -----------------------------+------------------+------------------+------------------ | ~1912.~ | ~1912.~ | ~1913.~ | Monoplane. | "Taube." | Hydro. -----------------------------+------------------+------------------+------------------ ~Length~ feet (m.)| 29-3/4 (9.50) | 34 (10.30) | 33 (10) ~Span~ feet (m.)| 41-1/2 (12.65) | 46 (14) | 49-1/4 (15) ~Area~ sq. feet (m².)| 247 (23) | 336 (32) | 387 (36) {total lbs. (kgs.)| 1398 (630) | 1190 (540) | 1328 (600) ~Weight~ { | | | {useful lbs. (kgs.)| 771 (350) | 551 (230) | 485 (220) ~Motor~ h.p.| 95 Mercedes | 100 Argus | 100 Argus {max. m.p.h. (km.)| 81 (130) | 59 (95) | 56 (90) ~Speed~ { | | | {min. m.p.h. (km.)| ... | ... | ... ~Endurance~ hrs.| 6-7 | 4-6 | ... Number built during 1912 | 1 | 60 | 3 -----------------------------+------------------+------------------+------------------ [Illustration: Rumpler. Hydro-aeroplane.] [Illustration: Rumpler. Monoplane.] [Illustration: Rumpler. "Taube." With limousine body.] RUTH-ROHDE. Ruth-Rohde, Motorgleitflieger, G. m. b. H., Wandsbeck. Established 1912. Capacity: small. [Illustration] -----------------------------+------------------+------------------ | ~1912.~ | ~1912.~ | Biplane I. | Biplane II. -----------------------------+------------------+------------------ ~Length~ feet (m.)| 26-1/4 (8) | 26-1/4 (8) ~Span~ feet (m.)| 36 (11) | 45 (14) ~Area~ sq. feet (m².)| 590 (55) | 700 (65) {total lbs. (kgs.)| 1653 (750) | 1764 (800) ~Weight~ { | | {useful lbs. (kgs.)| ... | ... ~Motor~ h.p.| 75 Argus | 75 Argus {max. m.p.h. (km.)| 55 (90) | 55 (90) ~Speed~ { | | {min. m.p.h.(km.)| ... | ... ~Endurance~ hrs.| 3 | 3-4 Number built during 1912. | 1 | 1 -----------------------------+------------------+------------------ ~S~ SCHELIES. Richard Schelies, Conventstrasse 5 und 5b, Hamburg 23. Flying Station, etc.: Dockenhuden a/Elbe. [Illustration] -----------------------------+-------------------- | ~1913.~ | Hydro-monoplane. -----------------------------+-------------------- ~Length~ feet (m.)| 23 (7) ~Span~ feet (m.)| 29-1/2 (9) ~Area~ sq. feet (m².)| 323 (30) {total lbs. (kgs.)| 705 (320) ~Weight~ { | {useful lbs. (kgs.)| 220 (100) ~Motor~ h.p.| Rheinische Aero 35 ~Speed~ m.p.h. (km.)| ... -----------------------------+-------------------- SCHULZE. Gustav Schulze, Flugzeug Werke, Burg b. Magdeburg. Schulze began to build in 1910 light monoplanes, generally along _Santos-Dumont_ lines. Maximum present capacity about 12 machines a year. [Illustration] -----------------------------+------------------+------------------+------------------+------------------ | ~1912.~ | ~1912.~ | ~1912.~ | ~1913.~ | I. | II. | III (2-seater). | I (2-seater). -----------------------------+------------------+------------------+------------------+------------------ ~Length~ feet (m.)| 19-3/4 (6) | 26-1/4 (8) | 21-1/3 (6.50) | 23 (7) ~Span~ feet (m.)| 26-1/4 (8) | 34-1/2 (10.50) | 28 (8.50) | 29-1/2 (9) ~Area~ sq. feet (m².)| 172 (16) | 215 (20) | 172 (16) | 194 (18) {total lbs. (kgs.)| 330 (150) | 441 (200) | 441 (200) | 551 (250) ~Weight~ { | | | | {useful lbs. (kgs.)| | ... | ... | ... ~Motor~ h.p.| 24-30 Hilz | 24-30 Hilz | 35 Haacke | 35 Haacke {max. m.p.h. (km.)| 48 (77) | 53 (85) | 56 (90) | 53 (85) ~Speed~ { | | | | {min. m.p.h. (km.)| ... | 43 (70) | 50 (80) | 46 (75) Number built during 1912. | 1 | 3 | 1 | _Building._ -----------------------------+------------------+------------------+------------------+------------------ SIGISMUND. Prinz Sigismund von Preussen, Berlin. [Illustration] -----------------------------+------------------+------------------ Model and date. | Monoplane. | -----------------------------+------------------+------------------ ~Length~ feet (m.)| 29-1/2 (9) | ~Span~ feet (m.)| 42-3/4 (13) | ~Area~ sq. feet (m².)| 323 (30) | {total lbs. (kgs.)| 950 (430) | ~Weight~ { | | {useful lbs. (kgs.)| 395 (180) | ~Motor~ | Argus, 100 | ~Speed~ max. m.p.h. (km.)| 56 (90) | Number built during 1912 | 2 | -----------------------------+------------------+------------------ ~U~ UNION FLUGZEUGWERKE. Union Flugzeugwerke G. m. b. H. Elsenstrasse 106 & 107, Berlin s. o. 36. Established 1913. Capital 500,000 marks. Capacity of works: 20 machines a year. [Illustration] -----------------------------+------------------+ | ~Bomhard.~ | Model and date. | Pfeilflieger, | | ~1913.~ | -----------------------------+------------------+ ~Length~ feet (m.)| 32-3/4 (10) | ~Span~ feet (m.)| 59 (18) | ~Area~ sq. feet (m².)| 450 (42) | {total lbs. (kgs.)| 1235 (560) | ~Weight~ { | | {useful lbs. (kgs.)| 617 (280) | ~Motor~ | 100 Argus | {max. m.p.h. (km.)| 69 (110) | ~Speed~ { | | {min. m.p.h. (km.)| 62 (100) | Number built during 1912 | New firm | -----------------------------+------------------+ ~W~ WRIGHT. Flugmaschine Wright, G. m. b. H., Adlershof, bei Berlin. Company formed to trade in German rights for the Wright Bros.' patents. Considerable departures have been made from the U.S. pattern, and some have been built with a single propeller only. Capacity of works 100-150 a year. [Illustration: Armoured war aeroplane.] -----------------------------+------------------+------------------+------------------+------------------ | ~1912.~ | ~1913.~ | ~1913.~ | ~1913.~ | Military. | Sporting. | Military. | Military. | | | | 4-seater. -----------------------------+------------------+------------------+------------------+------------------ ~Length~ feet (m.)| 28 (8.50) | 26-1/2 (8.20) | 31-1/2 (9.65) | ... ~Span~ feet (m.)| 39-1/2 (12.20) | 31 (9.60) | 40-1/2 (12.50) | 44-1/4 (13.50) ~Area~ sq. feet (m².)| 452 (42) | 323 (30) | 463 (43) | 463 (43) {total lbs. (kgs.)| 992 (450) | 837 (380) | 1433 (650) | 1653 (750) ~Weight~ { | | | | {useful lbs. (kgs.)| ... | ... | ... | 882 (400) ~Motor~ h.p.| 55 N.A.G. | 55 N.A.G. | 100 Argus or | 100 | | | Mercedes | {max. m.p.h. (km.)| 50 (80) | 60 (95) | 60 (95) | 60 (95) ~Speed~ { | | | | {min. m.p.h. (km.)| ... | ... | ... | ... Number built during 1912 | 10 | ? | ... | ... -----------------------------+------------------+------------------+------------------+------------------ ~Z~ ZIEGLER. Ziegler, Potsdam. Established late in 1912. [Illustration] -----------------------------+------------------ | ~1912-13.~ | Monoplane. -----------------------------+------------------ ~Length~ feet (m.)| 31 (9.50) ~Span~ feet (m.)| 39-1/3 (12) ~Area~ sq. feet (m².)| 344 (32) {total lbs. (kgs.)| 881 (400) ~Weight~ { | {useful lbs. (kgs.)| 992 (450) ~Motor~ h.p.| 100 N.A.G. {max. m.p.h. (km.)| 60 (90) ~Speed~ { | {min. m.p.h. (km.)| ... ~Endurance~ hrs.| 2 Number built in 1912 | 1 -----------------------------+------------------ GERMAN DIRIGIBLES. (Approximately 1000 m³=35,000 c. feet.) ~Military.~ ----------+--------------------------+--------------+-------+--------+------+-------------+---------------------- Date. | Name. | Make. | Type. |Capacity| Total| Speed. | Remarks. | | | | in m³. | H.P. | m.p.h. (km.)| ----------+--------------------------+--------------+-------+--------+------+-------------+---------------------- 1908 | ~Z I~ | Zeppelin 3b | r. | 12100 | 190 | 29 (46) | as _rebuilt_ | | | | | | | 1910 | ~Z II~ | Zeppelin 9b | r. | 18000 | 345 | 35 (56) | as _rebuilt_ " | ~L. S I~ |Schütte Lanz 1| r. | 20000 | 540 | 40 (62) | | | | | | | | 1912 | ~Z III~ | Zeppelin 12 | r. | 17800 | 450 | 49 (79) |was _Schwaben L. Z 10_ " | ~L I~ | Zeppelin 14 | r. | 22000 | 450 | 48 (77-1/2) | Naval: 1 gun | | | | | | | 1913 | ~Z IV~ (Z I _Ersatz_) | Zeppelin 15 | r. | 21000 | 450 | 48 (77-1/2) | 4 guns Building. | ~L II~ | Zeppelin 16 | r. | 21000 | 450 | 48 (77-1/2) | Naval: _bldg._ 4 guns | ~S. L II~ |Schütte Lanz 2| r. | 26000 | 450 | 48 (77-1/2) | _Building_ | | | | | | | ----------+--------------------------+--------------+-------+--------+------+-------------+---------------------- | | | | | | | 1908 | ~P I~ | Parseval 2 | n.r. | 3800 | 85 | 33-1/2 (54) | | | | | | | | 1911 | ~P III~ | Parseval 11 | n.r. | 11000 | 400 | 42-1/2 (67) | | | | | | | | 1912 | ~M I~ | Gross-Bas 2 | s.r. | 6000 | 150 | 28 (45) | old 1908 _rebuilt_ " | ~M II~ | Gross-Bas 3 | s.r. | 6000 | 150 | 28 (45) | old 1909 _rebuilt_ " | ~M III~ | Gross-Bas 4 | s.r. | 9000 | 300 | 42-1/2 (67) | old 1910 _rebuilt_ | | | | | | | 1913 | ~M IV~ | Gross-Bas 5 | s.r. | 12000 | 400 | 44-1/2 (70) | old 1911 _rebuilt_ " | ~P II~ ersatz | Parseval 8 | n.r. | 8250 | 300 | 41 (66) | _Building_ " | ~P IV~ | Parseval 16 | n.r. | 10000 | 360 | 45 (72) | _Building_ ----------+--------------------------+--------------+-------+--------+------+-------------+---------------------- ~Private.~[D] ------------+------------------------+--------------+-------+--------+------+-------------+---------------------- Date. | Name. | Make. | Type. |Capacity| Total| Speed | Remarks. | | | | in m³. | H.P. | m.p.h (km.) | ------------+------------------------+--------------+-------+--------+------+-------------+---------------------- 1910 | ~DEUTCHLAND 2~ | Zeppelin 6a | r. | 15000 | 345 | 36 (58) | Deutschland _Ersatz_ | | | | | | | Delag | | | | | | | 1912 | ~V. LUISE~ | Zeppelin 11 | r. | 17000 | 450 | 40 (62) | Delag " | ~HANSA~ | Zeppelin 13 | r. | 17000 | 450 | 40 (62) | Delag | | | | | | | 1913 | ~SACHSEN~ | Zeppelin 17 | r. | 21000 | | 48 (77-1/2) | _Building._ Delag _Bldg._ | | | | | | | | | | | | | | ------------+------------------------+--------------+-------+--------+------+-------------+---------------------- | | | | | | | 1908 | ~P. L 1~ | Parseval 1 | n.r. | 3200 | 185 | 20 (32) | | | | | | | | 1910 | ~STOLLWERCK~ | Parseval 6 | n.r. | 9000 | 220 | 31 (50) | | | | | | | | 1911 | ~P. L 9~ | Parseval 9 | n.r. | 2200 | 50 | 25 (40) | Sporting[E] " | ~R 2~ | Ruthenberg 2| n.r. | 1700 | | | Experimental | | | | | | | 1912 | ~SUCHARD~ |Suchard reb'lt| n.r. | 6730 | 200 | 17 (28) | to be _rebuilt_ 1913 " | ~P. L XII~ | Parseval 12 | n.r. | 8800 | 220 | 33-1/2 (54) | | | | | | | | 1913 | ~P. L 10~ | Parseval 10 | n.r. | 2200 | 50 | 25 (40) | _Building_: delayed " | ~R 3~ | Ruthenberg 3 | n.r. | 2700 | | | _Building_ ------------+------------------------+--------------+-------+--------+------+-------------+---------------------- ~Dirigible Sheds.~ (_See Note._) Bickendorf bei Köln. Biesdorf bei Berlin. *Bitterfeld (_Parseval Co._) Breslau. Cuxhaven. Düsseldorf (_Delag_) Frankfurt a/m. Friedrichshafen (_Zeppelin Co._) Gotha. Hamburg (_Delag_). *Johannisthal (_L.V.G._) Kiel (_private_). Köln. Königsberg i/Pr. Leichlingen. Manzell (_Zeppelin Co._) Metz. *München (_private_). Oos bei Baden-Baden (_Delag_). Potsdam (_Delag_) Reinickendorf bei Berlin. Rheinau. Strassburg. Stuttgart. Thorn. Note.--Unless otherwise stated the above are military sheds. All private ones capable of holding _Zeppelins_ are subsidised. *=not large enough for _Zeppelins_. ~Dirigible Pilots.~ For M. dirigibles. Geerdtz, Oblt. George, Hptm. v. Jena, Hptm. Kirchner, Oberltn. Lohmuller, Hptm. Masius, Oberltn. v. Muller, Hptm. Nichisch v. Rosenegk, Oberltn. Schlutter, Obltn. Sperling, Major. von Zech, Obltn. ~Dirigible Pilots.~ Z=Zeppelin. S=Schutte-Lanz. P=Parseval _pilot_. (The number after each name is the Imperial Ae. C. certificate number.) Z Abercron, H. v. Major (1) Z Bassus, K. v. (28) Z Bentheim, Kapt. Lt. a. D. v. (34) Z Blew (25) Clouth, R. (8) P Dinglinger, F. (2) Z Dorr, W. E. (21) Z Durr (9) Z Eckener, Dr. (10) P Forsbeck, Ob. Lt. A. D. (11) Z Glund, F. (23) Z Hacker, (12) P Hackstetter, Reg. B. a. D. (13) Z Hanne, G. (32) Z Heinen, A. (22) Z Holzmann, Ob. Lt. A. (26) S Honold, R. (29) P Hormel, Kap. Lt. (14) P Jordens, W. (19) P Kehler, R. v. (6) P Kiefer, T. (5) Kleist, Hptm. a. D. v. (15) PZ Krogh, Hptm. a. D. v. (16) Z Lange, K. (30) Z Lau (17) Z Lempertz, E. (33) Z Mechlenburg, W. C. (35) Z Meyer, Ob. Lt. E. (27) P Parseval, A. v. (4) Z Stahl, K. (31) P Stelling, A. (3) Z Sticker, J. (24) P Thewaldt, C. H. (20) Z Zeppelin, Graf. v. (7) Z Zeppelin, Graf. F. v. junr. (18) =GERMAN MILITARY CLASS--GROSS-BASENACH. (Semi-rigid)= Up to date, these vessels have been designed by Major Gross and Oberingenieur Basenach. The utmost secrecy is observed as to their details. The system of employing 2 ballonets has been borrowed from the _Parseval_ type, and presumably the _Parseval_ system of working the automatic valves has also been adopted. In all other features, these ships appear to resemble the French _Lebaudy_ type, the shape of the hulls being rather better. List of ships built, re-built and re-building of this type:-- 1 = Aeronautical Society. (1,800 m³) _non-effective._ 2 (reconstructed) = M 1, Military. (6,000 m³) 3 " = M 2 " (6,000 m³) 4 " = M 3 " (9,000 m³) 5 " = M 4 " (12,000 m³) M I (re-built 1912), & M II (re-built 1912). Military. [Illustration] ~Length,~ 242-3/4 feet} ~maximum diameter,~ 36 feet (11 m.) ~capacity~, 212,000 c. feet (6,050 kg.) ~total lift~, 13,338 lbs. (6,000 m³) _about_ 6 tons ~Useful lift.~--2,756 lbs. (1,250 kgs.)=about 1-1/4 tons. ~Gas bag.~--Continental rubber cloth, diagonal thread. Tapering shape. ~Ballonet.~--One-fifth of total volume. ~Motors.~--2-75 h.p. Daimler. 2 propellers, with 3 aluminium blades. ~Speed.~--About 28 m.p.h. (45 km.). _Remarks.--M I_ was originally built in 1908, re-built and enlarged 1910 and again in 1912. _M II_ built 1909, re-constructed 1912. [Illustration] M III (re-built 1912). Military. [Illustration] ~Length~, 295-1/4 feet (90 m.) ~diameter~, 39-1/3 feet (12 m.) ~volume~, 317,800 c. feet (9,000 m³.) ~Motors.~--4 Körting of 75 h.p. each = 300 h.p. total. ~Speed.~--19 metres per second = 42 m.p.h. (68-1/2 k.p.h.) ~Propellers.~--2, on outriggers from car, chain-driven. Remarks.--Built 1910. Burned 13th September, 1911. Rebuilt 1912. M IV (re-built 1913). Military. +---------------------+ | | +---------------------+ ~Maximum length~, 334-3/4 feet (102 m.) ~maximum diameter~, 44-1/2 feet (13.5 m.) ~volume~, 423,800 c. feet (12,000 m³.) ~Total lift.~-- lbs. ( kgs.) ~Useful lift~, lbs. ( kgs.) ~Gas bags.~--Continental. ~Motors.~--2 Körting, 100 h.p. each = total 200 h.p. ~Speed.~--44-1/2 m.p.h. (70-1/2 k.p.h.) ~Propellers.~--4 (two for each motor.) Carried on outriggers projecting from the car. Remarks.--Departs from previous practice in having two separate cars, each of which contains one motor. Originally built in 1911 of 7,500 m³. Re-built 1912-1913 to details as above. =PARSEVAL CLASS (Non-rigid).= Luftfahrzeug-Gesellschaft m.b.H, Berlin, W. 62. When the "Motorluftschiff Studien Gesellschaft" was formed at the instigation of the German Emperor, a committee was formed to acquire an experimental airship of the most promising type. Major Von Parseval's first airship was selected, and since that time the above company has confined itself to improving this type, and to making exhaustive and costly researches, all of which have been embodied in successive ships. The characteristic feature of every one of these craft is its unequalled portability. Almost all other so-called Non-rigid vessels distribute the load by means of a long girder which also serves as a car. This girder is awkward to pack up and transport. Parseval uses a comparatively small car, and distributes the weight by hanging it further below the balloon than usual, and also by using 2 ballonets which are placed one near each end of the gas bag. These 2 ballonets enable the ship to be trimmed by merely pumping air into either at the expense of the other. Another essential feature of the type is the system by which the valves are worked automatically. At the present time there is no other system of valve working so reliable as this. A third essential feature of the class is the use of a swinging car, in such a manner that pitching, due to alterations of propeller thrust, is automatically checked by an alteration of the position of the centre of gravity. A fourth feature is the use of limp propeller blades. A propeller of this type is very easily packed up. The shape of these vessels is in accordance with the experiments of Professor Prandtl. Ships of this class built or building (figures supplied by the Parseval Co.):-- EXPERIMENTAL PARSEVAL 2,300 m³. P. L. 1 Kals. Ae. C 3,200 m³. MILITARY P I 4,000 m³. MILITARY P II 6,600 m³. P. L. 4 Austrian Military 2,300 m³. P. L. 5 Luftverkehrs Gesellschaft 1,450 m³. P. L. 6 " " 9,000 m³. P. L. 7 Russian Army 7,600 m³. P. L. 8 MILITARY P II Ersatz 8,250 m³. P. L. 9 Luftverkehrs Gesellschaft 2,200 m³. P. L. 10 Motorluftschiff Studien Gesellschaft 2,200 m³. MILITARY P III 11,000 m³. P. L. 12 Luftverkehrs Gesellschaft 8,800 m³. P. L. 13 Japanese Army 8,500 m³. P. L. 14 Russian Army 9,500 m³. P. L. 15 Italian Army 10,000 m³. P. L. 16 MILITARY P IV, Prussian Army 10,000 m³. P. L. 17 Italian Army 10,000 m³. P. L. 18 British Navy 8,800 m³. (Of the above, the Experimental is no longer in existence, _P. 2_ is out of service, and _P. L. 3_ has been burned and destroyed). PARSEVAL (P.L. 1). (1908.) (Belongs to the Kaiserl. Aero Club.) (Parseval class.) [Illustration] ~Length,~ 197 feet (60 m.) ~max. diam.~ 31 feet (9.4 m) ~capacity,~ 113,000 c. feet (3,200m³) ~lifting power,~ 7,800 lbs. (3,583 kgs.) ~Gas bag.~--Cylindrical, with semi-conical front. Of rubber-proofed material in longitudinal strips. Pressure in ballonets and gas bag, 30 mm. of water. ~Motor.~--One 85 h.p. Daimler. ~Fuel.~--700 lbs. (325 kg.) 88 gallons (400 litres) ~Speed.~--20 m.p.h. (32 k.p.h.) ~Propeller.~--One 4-bladed. Semi-rigid Parseval. This vessel was somewhat altered on being bought by the Society. Her essential principle is that she can be taken to pieces in a few minutes, and carried in a truck. Her main feature is that she has a ballonet at each end. This is described in the case of type A (_P.L. 2_). This class rise with the forward ballonet empty, and inclined up by the bow. The propeller is similar to that of _P.L. 2_. The car also is mounted on wire runners. She was originally 4,000 m³. capacity. Built 1908. Station: Bitterfeld. The car is at present in Deutsches Museum, Munich. PARSEVAL P.L. 2 = P. I. Military. (1908.) [Illustration] Built by the "Society for the Study of Motor Air Ships," and taken over by the German War Office. ~Length,~ 197 feet (60 m.) ~maximum diameter,~ 34 feet (10.40 m.) ~capacity,~ 111,270 cubic feet (4,000 cubic m.) ~lifting power,~ 9,200 lbs. (4,180 kgs.) ~Gas bag.~--Front end semi-ellipsoidal with semi-axes 15.4 feet (4.7 m.) and 11.8 feet (3.6 m.), from which it increases to its maximum diameter. This is maintained for about two-thirds of its length, when it begins to taper to a point at the stern. Made of 2 layers of transverse strips of rubber proofed material, crossing each other diagonally. Fitted with a tearing strip. ~Ballonets.~--One at each end, together amounting to about one-quarter of the total capacity. Owing to this disposition, the trim can be altered, and steering effected in the vertical plane by filling either more than the other. Pressure in the ballonets and gas bag, 20 mm. of water pressure. ~Motor.~--4-cylinder 85 h.p. Daimler placed at one side of the car to give more room. 1,000 to 1,200 r.p.m. ~Propellers.~--12-1/3 feet (3.75 m.) diameter, 250 to 300 r.p.m. 4-bladed, the blades being of peculiar construction. When stopped, the fabric of which they are made hangs down limply; when running, these flaps fly out under centrifugal force. ~Speed.~--27 miles per hour. 43 kilometers per hour. ~Car.--Length~, 22-1/3 feet (6.8 m.) Width 4.1 feet (1.22 m.) Made of nickel steel, U bars, screwed together so as to take the pieces rapidly. The sides are lattice girders. The whole is boat shaped and covered with canvas. Contains motor, chart table; trail rope 480 feet (146 m.) long, weighing 220 lbs. (100 kg.) Wheel for horizontal steering at the bow. 110 gal. (500 litre) cask of petrol on the girders at the after point. 41 feet (12-1/2 m.) below the gas bag. It is capable of swinging horizontally on wires running over rollers. Whereas without this device a forward swing of the car would lift the nose to a possibly dangerous extent, the free motion of the car shifts the centre of the gravity forward and so preserves stability. ~Steering.~--In vertical plane, by altering the trim. In horizontal plane, by a rudder of 80.7 sq. feet (7-1/2 m²) immediately behind the vertical plane. Two fixed horizontal planes are placed at the rear end of the gas bag above the central line. [Illustration: PARSEVAL II.] ~Table of weights~:-- Gas bag 1,653 lbs. Cordage 220.5 " Trail rope 220 " Car and motor 529 " Fuel 770 " Oil 160 " Oil and fuel tanks, instruments, miscellaneous 1,637 " Crew, passengers, ballast 1,654 " --------- Total 6,834 lbs. Note.--This remarkably successful ship has performed a continuous flight of 11-1/2 hours. She also remained at a height of 4,800 feet (1,500 m.) for 1 hour. She can be transported in 1 railway truck or 2 pair horse wagons, and be assembled and filled ready for ascent within 3 hours of arrival by train. Built 1908. Station: Metz. PARSEVAL P.L. 6. "Stollwerck." (1910.) [Illustration] ~Length~, 229-3/4 feet (70 m.) ~Diameter~, 49-1/4 feet (15 m.) ~Volume~, 318,000 c. feet (9,000 m³) ~Gas bags.~--Riedinger. ~Motors.~--2 N.A.G. of 110 h.p. each = 220 h.p. ~Speed.~--31 m.p.h. (50 k.p.h.) ~Propellers.~--Two 4-bladed. Semi-rigid material. Remarks.--Station, Johannisthal. PARSEVAL P.L. 8. = P II. Ersatz. Military. (1913.) [Illustration] ~Maximum length~, 252-3/4 feet (77 m.) ~maximum diameter~, 50-3/4 feet (15.50 m.) ~volume~, 290,000 c. feet (8,250 m³.) ~Total lift.~--5-1/2 tons=12,125 lbs. (5,500 kgs.) ~Gas bags.~--2 ballonets, usual arrangement. ~Motors.~--300 h.p. made up of two 150 h.p. Daimler motors, placed one behind the other. ~Speed.~--41 m.p.h. (66 km.) ~Propellers.~--2 Parseval, 4-bladed, semi-rigid steel. ~Steering.~--As in others. Remarks.--Station, Cologne, (Cöln). PARSEVAL P.L. 9 (1910), & 10. (Building 1913.) [Illustration] ~Maximum length~, 164 feet (50m.) ~maximum diameter~, 26-1/4 feet (8m.) ~volume~, 77,700 c. feet (2,200m³.) ~Total lift.~--2,910 lbs. (1,320 kgs.) ~Gas bag.~--Continental fabric. One central ballonet instead of the usual two. ~Motors.~--1 N.A.G. of 50 h.p. ~Speed.~--25 m.p.h. (40 k.p.h.) ~Propellers.~--One 2-bladed, wooden. Diameter, 9-3/4 feet (3 m.) ~Steering.~--Differs from other standard types, in that only one ballonet being fitted, an elevator is introduced under the bow. Remarks.--Small ships for sporting purposes. A remarkably successful type of small dirigible. A small _P.L. 5_, burned 1912. _P.L. 10_ delayed owing to press of other work. [Illustration: PARSEVAL TYPE D.] PARSEVAL P.L. 11. = P. III. Military. (1911.) [Illustration] ~Maximum length~, 272-1/3 feet (83 m.) ~maximum diameter~, 53 feet (16.20 m.) ~volume~, 388,450 c. feet (11,000 m³.) ~Total lift.~-- ~Gas bags.~-- ~Motors.~--2 Körting, each of 200 h.p.=400 total. ~Speed.~--42 m.p.h. (67 k.p.h.) (18.3 metres p. sec.) ~Propellers.~--Two 4-bladed Parseval. Remarks.--Built 1911. Station, Koenigsberg. PARSEVAL P.L. 12. "Charlotte." (1912.) [Illustration] ~Maximum length~, 259 feet (79 m.) ~maximum diameter~, 49-3/4 feet (15.20 m.) ~volume~, 300,750 c. feet (8,800 m³.) ~Total lift.~-- ~Gas bags.~-- ~Motors.~--2 N.A.G. of 110 h.p. each=220 total. ~Speed.~--33-1/2 m.p.h.=54 k.p.h. (15 m. per sec.) ~Propellers.~--2 Parseval. ~Steering.~--Usual. Remarks.--Built 1911. Station: Wanne. PARSEVAL P.L. 16 = P. IV. Military. (1913.) +---------------+ | | | _Completing._ | | | +---------------+ ~Maximum length~, 308-1/2 feet (94 m.) ~maximum diameter~, 51-1/2 feet (15.50 m.) ~volume~, 353,000 c. feet (10,000 m³.) ~Gas bags.~--Metzler. ~Motors.~--2 Maybach, of 180 each=360 h.p. ~Speed.~--45 m.p.h.=72 k.p.h. (20 m. per sec.) ~Propellers.~--Two 4-bladed, wooden (on trial). Remarks.--For the Prussian Army. Station: Berlin. RUTHENBERG II. (1911). H. Ruthenberg, Lehderstrasse 16/19, Weissensee bei Berlin: also Luftfahrzeug-Ges, Ruthenberg, Krefeld. +-----------------------------------+ | | | _Small ships on Parseval lines. | | Still existing, but stored away._ | | | +-----------------------------------+ ~Maximum length,~ 151 feet (46 m.) ~diameter~, 24-1/4 feet 7.40 (m.) ~volume~, 60,000 c. feet (1,700 m³.) ~Gas bags.~-- ~Motor.~-- ~Speed.~-- ~Propellers.~--2 Ruthenberg. Remarks.-- RUTHENBERG III. (1913). +---------------+ | | | _Building._ | | | +---------------+ ~Length~, feet (m.) ~diameter~, feet (m.) ~volume~, 95,000 c. feet (2,700 m³) ~Gas bags.~-- ~Motor.~-- ~Speed.~-- ~Propeller.~--Ruthenberg. Remarks.-- SUCHARD. Non-rigid (Trans-Atlantic). (Re-constructed 1912). [Illustration] ~Maximum length~, 198-1/2 feet (60/5 m.) ~maximum diameter~, 56-1/4 feet (17.11 m.) ~volume~, 237,681 cubic feet (6,730 m³.) ~Total weight.~--About 2 tons (2,130 kgs.) ~Gas bags.~--Metzeler fabric. One ballonet. ~Motors.~--2 of 100 h.p. (one a N.A.G., the other an Escher). Placed one behind the other. A 4 h.p. motor carried for auxiliary purposes. Petrol carried, (1700 kil.) Oil, (300 kil.) ~Speed.~--17 m.p.h. (28 k.p.h). ~Propellers.~--Two 2-bladed Zeise. Diameter, 9-3/4 feet (3 m.) Chain driven. ~Steering.~--Elevation by moving weight slung on cable under body. Rudder aft. Remarks.--Built March, 1911, with a view to crossing the Atlantic from the Canaries to the Antilles. Re-constructed 1912. Proposed further re-construction in 1913. SCHÜTTE-LANZ 1. Military. S.L. I. (1911.) H. Heinrich Lanz, Rheinau bei Mannheim. [Illustration] ~Maximum length,~ 426 feet (130 m.) ~maximum diameter~, 60-1/2 feet (18.40 m.) ~volume~, 706,000 c. feet (20,000 m³.) ~Total lift.~--About 20 tons (20,000 kgs.) ~Useful lift.~--About 5 tons (5,000 kgs.) ~Gas bags.~--These are of great strength and of unusual shapes, made to fit the interior, which is encumbered with cross stays. All but two of the bags are always full, and when the gas expands it flows into the remaining two, which are nearly empty at sea level, and full at 6500 feet (2,000 m.) A centrifugal pump is used for distributing the gas. There are 14 gas bags. ~Motors.~--2 Maybach of 270 h.p. each. The propellers are at the ends of the car, driven through 1 set of reduction gear. ~Speed.~--38-43 m.p.h. About 59-64 k.p.h. ~Propellers.~--2 aft. Also 1 with its axis vertical. ~Steering.~--Vertical and horizontal rudders at both ends of the ship. Also see Propellers. Remarks.--Two of these ships were under construction, and one was to be presented and one sold to the German government. The hull is built of special 3-ply wood made of Russian white fir; this wood is pressed into channel bars, angle bars, and all other requisite shapes. The strength of the hull is such that it can be supported at the ends without damage; its lightness is such that although the ship is nearly half as large again as _Zeppelin II_, yet the hull weighs about 3 tons less. Designed by Prof. Schütte. In 1910, structural defects were found in _Schütte I_ when the loads were applied. This has necessitated extensive alterations and much delay. In 1911 it was completed, and sold for £25,000 to the German Army. SCHÜTTE-LANZ 2. Military. S.L. II. (1913.) +------------------------------+ | | | _Building._ | | Enlarged edition of above. | | 918,000 c. feet (26,000 m³.) | | | +------------------------------+ ZEPPELIN type. Rigid. Graf von Zeppelin, Friedrichshafen. The features of this type are--A rigid framework of aluminium, a number of drum-shaped gas bags, and a thin outer cover. [Illustration] At the end of March, 1913, the total of _Zeppelins_, limit and building was 16, including one (number 18) for Austria. Of these several had come to grief in various ways, and the actual total at the date mentioned, was:-- ~8 effective~ = 4 Army (of which one _Z4_ was still on trials), 1 naval and 3 private. 3 completing or building = 1 naval, 1 private and 1 for Austria. Others projected but not actually in hand. All are on the lines of the above plan, differing only in minor details, such as the provision of a cabin amidships, etc., and in dimensions. Details see the following pages. ----------------------------+------------------+-------------------+------------------+-------------------+--------------------+------------------+------------------+--------------------+------------------+------------------ | | _Ersatz._ | | | ~Z III.~ | | | _(Ersatz Z I.)_ | | Name | ~Z I.~ | ~DEUTSCHLAND.~ | ~Z II.~ | ~VICT. LUISE.~ | _(ex Schwaben)_ | ~HANSA.~ | ~L I.~ | ~Z IV.~ | ~L II.~ | ~SACHSEN.~ ~Zeppelin~ No. | ~3b.~ | ~6a.~ | ~9b.~ | ~11.~ | ~12.~ | ~13.~ | ~14.~ | ~15.~ | ~16.~ | ~17.~ Date | ~1908.~ | ~1910.~ | ~1911.~ | ~1912.~ | ~1912.~ | ~1912.~ | ~1912.~ | ~1913.~ | ~1913.~ | ~1913.~ Service | ~Army.~ | "Delag." | ~Army.~ | "Delag." | ~Army.~ | "Delag." | ~Navy.~ | ~Army.~ | ~Navy.~ | "Delag." ----------------------------+------------------+-------------------+------------------+-------------------+--------------------+------------------+------------------+--------------------+------------------+------------------ {c. feet| 424,000 | 682,000 | 635,000 | 667,000 | 629,000 | 660,000 | 776,000 | 742,000 | 742,000 | 742,000 ~Volume~ { | | | | | | | | | | { (m³.)| ~12,000~ | ~19,000~ | ~18,000~ | ~18,700~ | ~17,800~ | ~18,700~ | ~22,000~ | ~21,000~ | ~21,000~ | ~21,000~ ~Length~ feet (m.)| 446 (136) | 479 (136) | 459 (140) | 485-1/2 (148) | 459 (140) | 485-1/2 (148) | 518 (158) | 492 (150) | 492 (150) | 492 (150) ~Diameter~ feet (m.)| 38-1/2 (11.66) | 46 (14) | 46 (14) | 46 (14) | 46 (14) | 46 (14) | 47-1/2 (14.5) | 47-1/2 (14.5) | 47-1/2 (14.5) | 47-1/2 (14.5) ~Envelope~ | Pegamoid | ... | ... | ... | ... | ... | ... | ... | ... | ... {fabric| Continental | Continental | ... | ... | Continental | ... | ... | ... | ... | ... ~Gas Bags~ { | | | | | | | | | | {number| 17 | 16 | 16 | 18 | 16 | 18 | ... | 18 | ... | ... {total tons| 12-1/2 | 16-1/2 | 17 | 19 | 17 | 19 | 22 | 21 | 21 | 21 ~Lift~ { | | | | | | | | | | {useful tons| 3-1/2 | 5 | 4-1/2 | ... | 4-1/2 | ... | 6 | ... | ... | ... ~Motors~ h.p.| 2--85 Daimler | 3--115 Daimler | 3--120 Maybach | 3--150 Maybach | 3--150 Maybach | 3--150 Maybach | 3--150 Maybach | 3--150 Maybach | | | (= 170) | (= 345) | (= 360) | (= 450) | (= 450) | (= 450) | (= 450) | (= 450) | (= 450) | (= 450) {number | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | ... | ... ~Propellers~ {blades | 2 | 2 | 2 | 2 | 2 | ... | 2 forward} | 2 forward} | ... | ... { | | | | | | | 4 aft } | 4 aft } | | {diam feet (m.)| ... | 12 (3.60) | ... | ... | ... | ... | ... | ... | ... | ... ~Max. Speed~ m.p.h. (km.)| 29 (46) | 36 (57.5) | 35 (56) | 40 (62) | 49 (79) | 40 (62) | 48 (77) | 48 (77) | 48 (77) | 48 (77) ~Full speed endurance~ hrs.| 15 | 20 | 20 | 40 | 25 | 40 | 35 | ... | ... | ... ~Complement~ | ... | ... | ... |{8 crew | ... | ... | 21 | ... | ... | ... | | | |{25 passengers | | | | | | ~Station~ | Metz | Oos | Cologne | Wechselnd | Cologne | Weschselnd | Hamburg | ... | Johannisthal | Leipsig ----------------------------+------------------+-------------------+------------------+-------------------+--------------------+------------------+------------------+--------------------+------------------+------------------ [Illustration: Z1 Military. (1908.) _Obsolete._ Shortly to be struck off list.] [Illustration: ERSATZ DEUTSCHLAND. (Private.) (1910.)] [Illustration: Z II. Military. (1911.)] [Illustration: VIKTORIA LUISE. (Private.) (1912).] [Illustration: Z III. Military. (1912.)] [Illustration: Zeppelin dirigible. Sachsen.] [Illustration: HANSA. (Private). (1912.)] L I. Naval. (1912.) Armament: 1 gun on top. +-----------------------------+ | | | No photo procurable. | | Generally resembles _Z IV._ | | | +-----------------------------+ [Illustration: _Photo. Deliius._ Z IV. Military. (1913). Armament: 1 gun on top, 1 in each gondola, 1 can be lowered from central cabin] GREEK. ~Aerial Societies:~-- _None._ ~Aerial Journals:~-- _None._ ~Military Aeroplanes:~-- At end of March, 1913, these included:--1 _Astra_ hydro. (fitted with Scott's bomb dropper), 2 or 3 _Nieuports_, 1--100 h.p. _M. Farman_, and probably some others. Owing to the war, details are unobtainable. 3 _Bleriots_ reported captured from the Turks, and 15 _Farmans_ on order. ~Military Aviators:~-- Adamis (824 Ae. C. F.) Kamberos (744 Ae. C. F.) Montoussis (839 Ae. C. F.) Mutassas, Sub-lt., naval. Savoff, Lt. ~Flying Grounds~:-- ~Phaleron.~ +------------------+ | Killed 1913. | | Argyropulus, Lt. | | | | | +------------------+ ITALIAN. ~Aerial Societies:~-- Ae. C. d'Italia (Ae.C.I.), 62 via Colonna, Rome. Ae. Club di Roma (Ae.C.I.), 183, via del Triton, Rome. Circolo, Aeronautico Napoletano, 295 v. Roma, Naples. Lega Aerea Nazionale (L.A.N.), 6 via della Signora, Milan. Societa Aeronautica Italiana (S.A.I.), 4 via Boccaccio, Milan. Societa Aeronautica Italiana (S.A.I.), 6, via Cernaia, Turin. Societa Aviazone, di Torino (S.A.T.), 28 via Roma, Turin. Societa Ital. di Aviazone, (S.I.A.), 14 v. Monte Napoleone, Milan. ~Aerial Journals:~-- (3 times a week.) _Gazzetta dello Sport_, 15 v. della Signora, Milan. L--.05 (=1/2d.) (Weekly): _Italia Sportiva_, Rome. L--.05 per no. (=1/2d.) _Lettura Sportiva_, 17 corso Porta Romana, Milan. L--.10 (=1d.) _Sports (Gli)._ 46 and dei Prefretti, Rome. L--.05 (=1/2d.) _Stampa Sportiva_, 3 v. Davide Bertolotti, Turin. L--.10 (=1d.) _Tribuna Sport_, 22 via S. Giacomo, Naples. L--.10 (=1d.) (Monthly): _Rivista della L.A.N._ (Lega Aerea Nazionale), Milan. _Rivista del T.C.I._ (Touring Club Italiano), 14 v. Monte Napoleone, Milan. L--.40 (=4d.) _La Navigazione Aerea_ (Bolletino dell' Ae. C. d'Italia). L--1.80 (=1/6.) (Annual): _Annuario dell' Aeronautica_ (Touring Club Italiano), 14 v. Monte Napoleone, Milan. L--6.00 (=5/-) ~Flying Grounds~ (Military see next page):-- ~Cameri~, Novara.--15 hangars (Thouvenot school). ~Mirafiore~, Turin.--17 hangars (Asteria and Chiribiri schools). ~S. Giusto~, Pisa.--4 hangars (Antoni school). ~Taliedo~, Milan.--26 hangars. ~Vizzola Ticino.~--7 hangars (Caproni school). ~Dirigible Headquarters~ (with hangars, etc., etc.):-- Bracciano. Milan. Rome. Venice. Verona. ~ITALIAN MILITARY AVIATION.~ ~ORGANISATION, etc.~ The _Battaglione Aviatori_ has its headquarters at Turin. In July, 1912, it was re-organised along the following lines:-- 1 command at Turin. 1 flying work. 1 technical work. 2 troop duty. 6 at the aviation schools, with a certain number of mobile squadrillos. The recognised grades are:-- _a.a.p._ aspirante allievo (learners). _a.p._ allievo pilota (certificated pilots). _p._ pilota militare (superior military brevet). In flying work the superior pilots are mostly using _Bleriots_; the ordinary pilots _Bleriot-Caproni_, _Bristol_, _Antonis_, _Deperdussins_ and _Voisins_. The technical section chiefly supervises the theoretical instruction of the _a.a.p._ The 2 companies on troop duty practical work, preparation for the schools. ~FLYING SCHOOLS.~ The military schools are:-- ~Aviano.~--Central school. Size about 5×2 kilometres. Sheltered from all winds except westerly, by banks of trees. Numerous hangers. ~Mirafiori (Turin).~--Mixed military and civil school. Hangers. School machines confined to _Asteria_, _Bleriot_, _Nieuport_ and _Savary_ types. ~Pordenone.~--School for superior brevets. Treeless plain. Principal school machines _Breguets_ and _Farmans_; but some _Bleriots_ and _Caproni_. ~S. Francesco al Campo.~--_M. Farman_ machines. At present for officers trained in France. ~Somma Lombarda.~--Camp school for _Nieuports_. ~Venaria Reale.~--Formed late in 1912. _Bristol_ monos for certificated pilots. ~GENERAL TRAINING.~ 50 officers in training during the first quarter of 1913. Aspirants commence with instruction in the theory of heavier than air machines, resistance of material and particular instruction in the various type of aero motors in use. They are taken for flights as passengers. All then go to the training camp about 80% for monoplane work, the remainder for biplanes. Monoplanes. Special attention paid to teaching _Gauchis Dessent_. Biplanes. Much shorter course. Principal feature: _Vol Plané_. For the _military brevet_ the examination is most comprehensive, special attention is paid to flying in wind, manoeuvring, climbing, good landings without inconvenience to passengers, cross country flights, etc. The course is generally modelled on war experiences. ~TOTAL FLYING STRENGTH.~ No particular distinction between naval and military aviators. Total by end of June, 1913, to be about 225 certificated aviators of whom a fair percentage hold the superior brevet. In addition all the best civilian aviators are held at disposal. ~Military Aeroplanes.~ At the end of 1911 there were about 20 machines, mostly _Bleriots_ and _Farmans_. The majority of these are still in use for school purposes. At the end of March, 1913, the machines effective for war purposes were roughly as follows:-- _Bleriot._ } _Bristol_ (mono.) } _Caproni._ } _Deperdussin._ } Total _about_ 50, plus a number _Farman._ } of school machines. _Hanriot._ } _Nieuport._ } _Savary._ } About 40 machines were on order, including 12 _Bristol-Capronies_. ~Naval Aeroplanes.~ Effective at end of March, 1913. 1 _Calderara_. 1 _Guidoni-Farman_. 4 or 5 others. ~ITALIAN AVIATORS.~ Military. Agostoni, Capt. V. (45) Bailo, Lieut. (71) *Bolla, Capt. (89) Cannonieri, Lieut. (22) +Cammarotta, Lieut. (15F) De Filippi, Com. (5) *De Rada, Lieut. (38) *Falchi, Capt. (55) Garassini. (29) *Gavotti, Lieut. (25) Gazzera, Lieut. (20) Guidoni, Capt. (58) *Lampugnani, Lieut. (33) +Manazini, Lieut. (98) Moizo, Capt. (40) Neri, Lieut. (345-Ae. C. F.) (106) *Palmadi, Cesnola Lieut. (75) *Piazza, Major (44) Pizzagalli, Capt. (49) Poggi, Lieut. (82) Prandoni, Capt. (69) *Pulvirenti, Lieut. (50) Raffaelli, Lieut. A. (108) Ravelli (453, Ae. C. F.) Roberti, Lieut. (47) Rossi, Capt. (27) +Saghetti, Lieut. (16) Savoia, Lieut. T. U. (4) Surdi, Lieut. (32) *Vece, Lieut. F. (74) +Vivaldi, Lieut. (31) _Brevets in 1912._ Andriani, Capt. O. (137) Antonini, Capt. L. (91) Almerigi, F. (159) Alvisi, Lieut. A. (172) Baglione, Lieut. A. (129) Baracca, F. (167) Bonamici, L. (101) Bongiovanni, Lieut. E. (115) Bongiovanni, c. L. (124) Bonuti, R. (135) Brach, Lieut. F. (146) Buzzi, Lieut. M. (156) Calderara, Lieut. A. (134) Calori, S. (136) Capuzzo (143) Casabella, Lieut, G. (121) Clerici, Lieut. U. (110) Cuzzo, Capt. A. (166) De Giovanni, Lieut. G. (101) De Riso, Lieut. G. (153) Della Chiesaconte, Lieut. A. (109) Ercole, Lieut. E. (117) Franceschini, Lieut. E. (112) Gallotti, Lieut. A. (150) Garino ing. G. (134) Girotti, Lieut. M. (100) Gordesco, Lieut. M. (151) *Graziani, Lieut, C. (92) Jacoponi, Lieut. A. (171) Kerbaker, Lieut. E. (99) Laureati, Lieut. G. Leffi dott. sott. med. A. (169) *Mareno, M. A. (90) Moreno, Capt. G. (78) Nosari, G. (142) *Novellis di Coarazze, Capt. A. (94) Oddo, A. (147) Pagano, P. (158) Palpacelli, A. (164) Perrucca, D. (162) Poggioli, Q. (107) Pongelli, R. (60) Porta, Capt. E. (145) Prandoni, Capt. E. (69) Resio, Lieut. (120) Rosetti, A. (157) Russi, Lieut. S. (152) Suglia, Lieut. C. (118) Torelli, F. (165) Valdimiro, Lieut. F. (170) Venanzi, U. (155) Zanuso, Lieut. G. (149) Naval. (_To end of 1911_). Calderara, Lieut. (1) Ginnochio, Lieut. (18) *Rossi, Sub. Lieut. (31) Strobin, Lieut. (39) (_During 1912_). De Muro, Lieut. (119) Frigerio, Lieut. (154) Scelsi, Capt. difreg. G. Private. (_To end of 1911_). Akachew, C. (61) Amerigo (3) Barigiola, G. (51) Battagli, B. (34) Bianchi, P. (6) Biego, C. (56) Bigliani, A. (63) Borgotti, G. (43) Brilli, D. G. (48) Brociner, M. (87) Cagno, U. (10) Cagliani, A. (23) Cannoniere, Umberto (22) Cattaneo, Bartelomo (2) Cavaglia, Pietro (30) Cavalieri, Alfredo (17) Cei, J. (53, Ae. C. F.) Casaroni, A. (77) +Cirri, Ciro (11) Cobianchi, Mariot (24) Darioli, Ernesto (9) Da Zara, Leonino (7) De Agostina, A. (53) De Antonis, A. (67) Faccioli, Mario (21) Franzoni, R. (62) Garassini, G. G. (29) Gianfelice (59) Ginnochio, T. (18) Graziani, nob. Ettere (28) Lusetti, A. (19) Maffeis, C. (36) Maggiora, C. (72) Manissero, R. (37) +Marra, R. (35) Marro, E. (52) Mogafico, Mario (26) Mosca, Francesco (47) Pasquali, R. (66) Picollo, G. (32) Poggioli, Quinto (117) Porro, A. (113) Ramasotto, M. M. (148) Ravetto, Clemento (12) Ré, Umberto (86) Ruggerone, G. (14) Sabelli, G. (93) Santoni, L. (114) Stucchi, Federico (8) Verona, A. (54) (_Brevets in 1912_). Amour, ing. E. Arista, A. (131) Ballerini, M. (132) Bergonzi, P. C. (78) Berni, L. (95) +Bertoletti, R. (79) Borsalino, G. M. (102) Brunetta D'Usseaux, G. (125) Carabelli, C. (104) +Caramanlaki, A. (97) Caramanlaki, G. (168) Carminati di, B. N. (163) Colucci, G. (80) Corsini, J. C. (133) Corsini, A. E. (85) Dalla, N. C. (126) Dal Mistro, C. A. (127) De Campo conte, S. (103) Fabri, A. (165) Facchini, E. (141) Garino, G. (134) Gelmetti, A. (83) Grassi, conte A. (88) Leonardi, G. (122) Mandelli, P. (96) Marazzi, E. (140) Nardini, G. (128) Paolucci, G. (144) Piceller, G. (105) Sacerdoti, C. (116) Salengo, R. (138) Vallet, C. (86) Zorra, L. (84) ~Private Aeroplanes.~ At the end of March, 1913, there were about 45 machines in use at the various private schools, and about 6 privately owned aeroplanes. ITALIAN AEROPLANES ~A~ ANTONI. Soc. di aviazione Antoni, via Vitt. Emanuele, 46, Pisa. School: S. Guisto, Pisa. Output capacity: about 20 machines a year. ----------------------------+-------------------+-------------------+ | ~1912-13.~ | ~1912-13.~ | | Single seat mono. | 2-seater military | | | mono. | ----------------------------+-------------------+-------------------+ ~Length~ feet (m.)| 33 (10) | 36 (11) | ~Span~ feet (m.)| 28 (8.50) | 28 (8.50) | ~Area~ sq. feet (m².)| 172 (16) | 237 (22) | {machine lbs. (kg.)| 660 (300) | 770 (350) | ~Weight~ { | | | {useful lbs. (kg.)| ... | ... | ~Motor~ h.p.| Gnome or Anzani | Gnome and Anzani | {max. m.p.h. (km.)| ... | ... | ~Speed~ { | | | {min. m.p.h. (km.)| ... | ... | ~Endurance~ hrs.| ... | ... | Number built during 1912 | ... | ... | ----------------------------+-------------------+-------------------+ ASTERIA. Fabbr. Ital. Aeroplani ing. Darbesio e. C., via Salbertrand, 12, Torino (Turin). School: Mirafiori. Capacity: small. -----------------------------+-----------------+-----------------+ | ~1912-13.~ | ~1912-13.~ | | Monoplane. | Biplane. | -----------------------------+-----------------+-----------------+ ~Length~ feet (m.)| 21-3/4 (6.50) | 29-1/2 (9) | {| 26-1/2 (8.10) | 44 (13.50) | ~Span~ feet (m.){| | | {| ... | 24-1/2 (7.50) | ~Area~ sq. feet (m².)| 162 (15) | 431 (40) | {machine lbs. (kgs.)| 530 (240) | 110 (500) | ~Weight~ { | | | {useful lbs. (kgs.)| ... | ... | ~Motor~ h.p.| 50 Gnome | 70 Renault | {max. m.p.h. (km.)| ... | ... | ~Speed~ { | | | {min. m.p.h. (km.)| ... | ... | ~Endurance~ hrs.| ... | ... | Number built during 1912 | ... | ... | -----------------------------+-----------------+-----------------+ ~C~ CALDERARA. Navy hydro-monoplane. ----------------------------+-------------------- Model ~1912-13.~ | "Hydro vol." ----------------------------+-------------------- ~Length~ feet (m.)| 54 (16.50) ~Span~ feet (m.)| 61 (18.50) ~Area~ sq. feet (m².)| 753 (70) {total lbs. (kgs.)| 2644 (1200) ~Weight~ { | {useful lbs. (kgs.)| ... ~Motor~ h.p.{| 150 (formerly 100 {| Gnome) {max. m.p.h. (km.)| 62 (100) ~Speed~ { | {min. m.p.h. (km.)| 50 (80) ~Endurance~ hrs.| 6-1/2 Number Built during 1912 | 1 ----------------------------+-------------------- Lieut. Calderara's floats consist of a plurality of w.t. compartments with internal lattice frame, well braced. Hull is formed of three skins of wood, sail-cloth between each. Distance between outer floats, 21 feet (6.30 m.) Centre of gravity is only 4-1/2 feet (1.40 m.) above water. If necessary wings can be cut away and the central hull used as a boat with emergency sail. [Illustration: CALDERARA. UAS.] CAPRONI. Soc. di Aviazione Ingg, Caproni e Faccanoni, Vizzola Ticino. School: Vizzola Ticino. -----------------------------+------------------+------------------+------------------+------------------ Models ~1912-13.~ | Single Seat | Single Seat | 2-seater mono. | 3-seater mono. | mono. A. | mono. B. | | -----------------------------+------------------+------------------+------------------+------------------ ~Length~ feet (m.)| 26-1/4 (8) | 26-1/4 (8) | ... | ... ~Span~ feet (m.)| 29 (8.80) | 29 (8.80) | ... | ... ~Area~ sq. ft. (m².)| 162 (15) | 162 (15) | 172 (16) | 226 (21) {machine lbs. (kgs.)| 485 (220) | 660 (300) | 750 (340) | 760 (345) ~Weight~ { | | | | {useful lbs. (kgs.)| ... | ... | ... | ... ~Motor~ h.p.| 35 Anzani | 50 Gnome | 60 Anzani | 80 Gnome {max. m.p.h. (km.)| 56 (90) | 75 (120) | 75 (120) | 87 (140) ~Speed~ { | | | | {min. m.p.h. (km.)| ... | ... | ... | ... ~Endurance~ hrs.| 3-1/2 | ... | ... | 4 Number built during 1912 | ... | ... | ... | ... -----------------------------+------------------+------------------+------------------+------------------ Remarks.--At the end of 1912, held Italian record for speed, 200-300 k.m. Flown by Cobioni. CAPRONI-BRISTOL. Caproni also builds under Bristol license. CHIRIBIRI. A Chiribiri e. C, via Lamarmora 28, and via Don Bosco 68-73. Torino (Turin). [Illustration: CHIRIBIRI.] -----------------------------+------------------+------------------+------------------+------------------ Models ~1912-13.~ | 45 h.p. mono. | 50 h.p. mono. | Racing mono. | 80 h.p. mono. -----------------------------+------------------+------------------+------------------+------------------ ~Length~ feet (m.)| 23 (7) | 23 (7) | 24-3/4 (7.50) | 25-3/4 (7.80) ~Span~ feet (m.)| 29-1/2 (9) | 29-1/2 (9) | 31 (9.30) | 39-2/3 (12.10) ~Area~ sq. ft. (m².)| 204 (19) | 204 (19) | 226 (21) | 258 (24) {machine lbs. (kgs.)| 595 (270) | 683 (310) | 772 (350) | 595 (270) ~Weight~{ | | | | {useful lbs. (kgs.)| ... | ... | ... | ... ~Motor~ h.p.| 45 Chiribiri | 50 Chiribiri | 60 Chiribiri | 80 Chiribiri {max. m.p.h. (km.)| 44 (70) | 56 (90) | 103 (165) | 65 (105) ~Speed~ { | | | | {min. m.p.h. (km.)| ... | ... | ... | ... ~Endurance~ hrs.| ... | ... | ... | ... Number built during 1912 | ... | ... | 2 | ... -----------------------------+------------------+------------------+------------------+------------------ ~F~ FRIULI. E. Pensuti e E. Calligaro, Pordenone. School: Pordenone. A 30-35 h.p. Anzani motor monoplane. Area, 150 sq. feet. (14 m²). Generally of _Bleriot_ type, but _Hanriot_ type landing carriage. ~G~ GUIDONI. Naval Hydroavions. Either a _Farman_ biplane or a _Nieuport_ mono. is used, mounted on special floats designed by Capitano del Genio navale Guidoni. There are two long floats, each of which is fitted with parallel fins. ~FOREIGN AGENCIES.~ Foreign types of machines are constructed in Italy under licenses as follows:-- BLERIOT. Soc. Ital. Transaerea, corso Peschiera 25, Torino (Turin). BRISTOL. (British), by Caproni. DEPERDUSSIN. Soc. Ital. degli Aeroplani, via Giulini 7b, Milan. NIEUPORT. Carrozzeria Macchi. Varese. ITALIAN DIRIGIBLES. ~ITALIAN MILITARY DIRIGIBLES.~ ~Army.~ ~Navy.~ /----------------------------------------------^--------------------------------------------------\ /-----------------^-----------------\ --------------------------------+------------------+------------------+------------------+----------------------+------------------+------------------+------------------ Name and Date. | ~P1.~ | ~P2 & P3.~ | ~P4 & P5.~ | ~Citta di Milano~ | ~Parseval.~ | ~M1.~ | ~M2 & M3.~ | 1909. | 1910 & 1911. | both 1912. | 1912. | (P.L. 17). | 1912. | 1912 & 1913. | | | | | 1912-13. | | --------------------------------+------------------+------------------+------------------+----------------------+------------------+------------------+------------------ { c. feet| 148,000 | 155,000 | 166,000 | 424,000 | 353,000 | 424,000 | 424,000 ~Volume~ { | | | | | | | { (m³.)| (~4200~) | (~4400~) | (~4700~) | (~12000~) | (~10000~) | (~12000~) | (~12000~) ~Length~ feet (m.)| 197 (60) | 207 (63) | 207 (63) | 233 (72) | 279 (85) | 272-1/3 (83) | 272-1/3 (83) ~Diameter~ feet (m.)| 38 (11.60) | 38 (11.60) | 39-1/3 (12) | 59 (18) | 52-1/2 (16) | 56 (17) | 56 (17) {fabric | Silk | Continental | Continental | ... | Riedinger | Metzeler | Metzeler ~Gas bags~ {compartments | 7 | 8 | 8 | ... | 0 | ... | ... {ballonets | 1 | 1 | 1 | ... | 2 | ... | ... {total tons | 3.50 | 3.50 | 3.75 | ... | ... | 9.50 | 9.50 ~Lift~ {useful tons | 1.10 | 1.35 | 1.50 | ... | 3.00 | 3.80 | 3.80 ~Motor~ h.p. {| 1-100 C. Bayard | 1-120 C. Bayard | 2-80 Fiat | 2-85/100 Isotta | 2-170 Maybach | 2-250 Fiat | 4-125 Wolseley {| (=100) | (=120) | (=160) | (=170/200) | (=340) | (=500) | (=500) {number | 2 | 2 | 2 | 2 | 2 Parseval | 2 | 2 ~Propellers~{blades | 2 | 2 | 2 | 3 | 4 | 4 | 4 {diameter feet (m.)| 10 (3) | 10 (3) | 10 (3) | 14 (4.20) | ... | 12-1/2 (3.80) | 12-1/2 (3.80) ~Max. speed~ m.p.h. (km.)| 32 (52) | 35 (56) | 37 (60) | 45 (72) | 40 (65) | 44 (70) | 44 (70) ~Full speed endurance~ hrs.| ... | ... | ... | ... | 20 | 12 | 12 ~Max. complement~ | 5 | 5 | 5 | ... | ... | 14 | 14 ~Station~ | Bracciano | Tripoli | Vigna di Valle | Baggio | Venice | Bracciano | --------------------------------+------------------+------------------+------------------+----------------------+------------------+------------------+------------------ Notes: All the above are semi-rigid. The _P_ and _M_ are all of the same general type. Principal features of these ships, which were designed by Captains Crocci and Ricaldoni, are the shape of the envelope, (maximum diameter very far forward), keel and the box kite tail. The _Citta di Milano_ (semi-rigid) is an enlarged _Leonardo da Vinci_ (which see). _Special feature_ is the keel built into the envelope. This serves as a nacelle. Building.--One _Parseval_ (P.L. 15) about the same size as the other (P.L. 17), which was completed first. ~Army Dirigible Pilots.~ Agostoni, Capt. Biffi, Ten. Bosio, Ten. Crocco, Capt. G. Dal Fabbro, Capt. C. Denti di Piraino, March, Capt. Gallotti, Ten. Longo, Ten. Manni, Ten. Menenti, S. Ten. Merzari, Capt. Messina, Ten. Munari, Capt. E. Pastina, Capt. Ricaldoni, Capt. A. Scelso, Ten L. Seymandi, Capt. G. Stabarin, Ten. Tagliasacchi, Ten. ~Navy Dirigible Pilots.~ Carniglia, Ten. d. vas. Gravina, Ten. d. v. Conte M. Penco, Ten. d. v., A. Ponzio, Ten. d. v., E. Scelsi, Capt. di f., G. Valerio, Sot. V. Valli, Ten. d. v., G. [Illustration: P.I.] Elevation of P. I. The later ships only differ in dimensions, and the fact that the middle rudder is done away with. [Illustration] [Illustration: Dirigibles M1 & M2.] [Illustration: Citta di Milano.] [Illustration: Parseval (P.L. 17). First Italian _Parseval_.] ~ITALIAN PRIVATE DIRIGIBLES.~ ----------------------------------+--------------------+------------------+------------------+----------------------+------------------+ Name and date. | ~Ausonia bis.~ | ~Italia I.~ | ~Italia II.~ | ~Leonardo da Vinci.~ | ~Usuelli.~ | | Reconstructed 1910.| 1905. | 1913. | 1909. | 1909. | ----------------------------------+--------------------+------------------+------------------+----------------------+------------------+ ~Volume~ (m³.)| (~1500~) | (~1500~) | (~2600~) | (~3265~) | (~3870~) | ~Length~ feet (m.)| 121 (37) | 128 (39) | 164 (50) | 131-1/4 (40) | 167-1/3 (51) | ~Diameter~ feet (m.)| 27 (8.25) | 19-3/4 (6) | 32-3/4 (10) | 46 (14) | 32 (9.80) | {fabric | ... | ... | ... | ... | ... | ~Gas bags~ {compartments | nil. | nil. | nil. | 7 | 6 | {ballonets | 1 | nil. | nil. | 1 | 1 | {total tons| ... | 1.35 | 2.20 | 3.00 | ... | ~Lift~ { | | | | | | {useful tons| 0.80 | ... | ... | ... | ... | ~Motor~ h.p.| 1-55 h.p. S.P.A. |1-40/50 Antoinette| 1-50 h.p. | 1-40 Antoinette | 1-80 h.p. S.P.A. | {number | 1 | 1 | 2 | 2 | 2 | ~Propellers~ {blades | 2 | 2 | 2 | 5 | 2 | {diameter, feet (m.)| 10-3/4 (3.20) | 15 (4.50) | 10 (3) | 9 (2.70) | ... | ~Max. speed~ m.p.h (k.m.)| 25 (40) | 25 (40) | ... | ... | 30 (50) | ~Full speed endurance~ hrs.| ... | ... | ... | ... | 6 | ~Max. complement~ | ... | ... | ... | ... | ... | ~Station~ | Bosco Mantico | Schio | building | Laid up at Baggio | Turin | | | | | near Milan | | ----------------------------------+--------------------+------------------+------------------+----------------------+------------------+ Notes: ~Ausonia.~ Nico Piccoli, via Accademia 12, Padova (Padua). Works: Magré, Vicenza (Schio). Semi-rigid. ~Italia.~ Cont Almerico da Schio, Schio. Non-rigid. _Special features_ is a "belly" of Para rubber in lieu of a ballonet. ~Leonardo da Vinci.~ Ing. Enrico Forlanini, via Boccaccio 21, Milan. Works: Baggio. Semi-rigid, keel and nacelle, incorporated in envelope. ~Usuelli.~ Usuelli and Borsalini, Torino (Turin). Non-rigid. ~Private Dirigible Pilots.~ Forlanini, ing. E. Piccoli, D. Usuelli, C. [Illustration: Italia.] [Illustration: Usuelli.] [Illustration: ~FORLANINI.~ UDS.] [Illustration: Leonardo da Vinci.] JAPANESE. (Naval Aviation data. Official). ~Aerial Societies~:-- Tokio, Ae. Co. Aeroplane Assoc., 1, Yayesu Cho, I-Chome, Kojimachi, Tokio. (Sec.: Dr. Fujioka). Kikyu Kinkyu Kai (connected with War Office). ~Flying Grounds~:-- Near ~Yokohama~. ~Saitama~, Tokorozawa (Government).--Dirigible shed and hangars. ~Port Arthur~, (Government). ~General Military Aviation.~ This was originally formed as one body without distinction between army and navy. It was subsequently re-modelled on lines somewhat similar to the British Royal Flying Corps with naval and military wings. ~Navy.~ The naval section is superintended by Capt. K. Yamaji, I.J.N. The naval headquarters are at Oihama (near Yokosuka). The naval force at the end of 1912 consisted of 4 hydro-aeroplanes (2 _Curtiss_ and 2 _Farman_). The available total of qualified naval aviators was 5. ~Finance.~ The total amount granted for aviation of the navy in 1912 (fiscal year) was 100,000 yen (£10,000). For the year 1913 the estimates amount was 100,000 yen (but not approved yet). ~Pay of Flying Officers.~ The special pay for officers employed in aerial work is undecided. ~Army.~ The army wing is responsible for the dirigible. Aeroplanes are one or two _Bleriots_, a _Grade_, 2 _Tokogawa_, and a _Farman_. ~AVIATORS.~ Military. Hino, Major Saigom, Capt. Tokogawa, Capt. Tokogama, Lieut. Naval. Narahara, Naval Constr. Kaneko, Lieut. Kono, Lieut. Obama, Eng. Lieut. Umikita, Lieut. Usuioku, Naval Constr. Private. Doig, S. Iga, Baron Shigeno, Baron Tsuzuki, Yamada, Isaburo The following have been killed:-- +----------------+ | 1912. | | Aibata, Lieut. | | | | 1913. | | Kimura, Lieut. | | Tokuda, Lieut. | | Takeishi. | +----------------+ ~Private Aviation.~ There are some private aeroplanes being regularly flown in Japan. A number of aeroplanes have from time to time been invented by naval and military officers and private individuals, and some of them are in use. Inventors include Major Hino, naval constructor Narahara and Ushioki, Baron Iga, Baron Shigeno and Mr. Tsuzuki. JAPANESE AEROPLANES. [Illustration: Bleriot (since wrecked). Tokogawa. Wright. Grade. Army Flying School ground.] [Illustration: Narahara.] [Illustration: Tokogawa II. Type I the same except for minor details.] JAPANESE DIRIGIBLES. PARSEVAL type. Military. (P.L. 13.) [Illustration] ~Length~ 259 feet (19 m.) ~maximum diameter~ 47-3/4 feet (14.50 m.) ~capacity,~ 8,500 m³. ~Gas bag.~--2 ballonets. Usual Parseval. ~Motors.~--Total, 300 h.p., made up of two 150 h.p. Maybach. ~Speed.~--42 m.p.h. (65 km.) ~Propellers.~--Two 4-bladed. Parseval. ~Steering.~--Usual Parseval (see German). Remarks.--Of _Parseval P.L. 12_ type (see German). Built 1911. YAMADA. Non-rigid. (Private.) [Illustration: _Photo by favour of M. Samuro Kuki._] ~Maximum length~, feet ( m.) ~maximum diameter~, feet ( m.) ~volume,~ 700 m³. (_about_) ~Gas bag.~-- ~Motor.~--American make. ~Speed.~-- ~Propeller.~--One. ~Steering.~--Biplane elevator forward. Triangular rudder in rear under gas bag. Remarks.--Generally of American type. MEXICAN. ~Army Aeroplanes.~ There are 2 old pattern _H. Farman_; also one or more _Curtiss_ and _Wright_ machines. Nothing seems doing with them. ~AVIATORS.~ Military. Martinez, N. (Ae. C. F. 462) Mendia, (Ae. C. F. 680) Private. Duval, Raoul Lebrija, Miguel Morales Noriega Ramsey, E. L. Saavedra, Alfonso Probably 2 others (The above are mostly amateur builders.) NORWEGIAN. ~Aerial Societies:~-- Aero Club, Norsk Flyveselskad (Christiana). Secretary, D. Barth. Norsk Luftseilads Forening (Christiana). President, H. Mohn. ~Aerial Journals:~-- _None._ ~Flying Grounds:~-- ~Military Aviation.~ At the end of 1912 the Army possessed two 70 h.p. _M. Farmans_ (Renault motors), and the Navy a 100 h.p. N.A.G. _Rumpler_. For 1913 the purchase of further machines is contemplated for both arms. ~Private Aeroplanes.~ Total at end of ~1911~ 1 At end of 1912 there were in existence 2--a _Grade_ and a _Deperdussin_. ~AVIATORS.~ ~Military.~ Dichi, Lieut. Jacobsen, Lieut. ~Private.~ Hansen. St. Dons. PERUVIAN. ~Military Aeroplanes.~ The Peruvian Government has made a special grant for aviation students, and war machines are projected. Actual order to end of 1912 was one _Avro_ mono. ~Private Aeroplanes.~ Total at end of ~1910~ 3 " ~1911~ 2 " ~1912~ _none_ probably. ~AVIATORS.~ Bielovucic, J. Chavez, J. Monterc (766 A. C. F.) Peruvian aviators killed: +------------+ | 1910. | | Chavez, G. | | | | 1911. | | Tenaud, C. | | | +------------+ PORTUGUESE. (Revised by J. SCHIERE, Aeronautical Engineer.) ~Aerial Societies:~-- Ae. C. de Portugal (R. Nova docklaemada d. ISL.) ~Aerial Journals:~-- Rivista Aeronautica (Ae. C. Journal.) ~Flying Grounds:~-- Campo do Seigcal. Mounchãvo da Povoa. ~Private Aeroplanes.~ Total at end of ~1910~ 1 " ~1911~ 2 " ~1912~ 2 ~Private Aviators.~ De Castro, Sanchez De Silva, Gomez ~Military Aviation.~ In 1912 a military corps was formed. At the end of 1912 it possessed _Avro_ (1--50 h.p.), _Voisin_ (1--80 h.p.), and _M. Farman_ (1--80 h.p.) (since wrecked). 1 _Deperdussin_. ~Private Aviation.~ In 1911 the _Gouveia_ mono. was built, span 9 metres, but it failed to fly. Also the _Avante_ biplane, which also failed. First flight in Portugal by a Portuguese was De Castro in September, 1912, with an old _Bleriot_. ROUMANIAN. ~Army Aeroplanes.~ At end of March, 1913, there were several 80 h.p. _Bristol_ monos., 2 _Bleriots_, 1 _Nieuport_, 1 _Morane_, 2 _Vlaiclu_, and several _H. Farman_ biplanes. Government school is at Bucharest. ~AVIATORS.~ Military. Capsa, Lieut. Negrescu, Lieut. Protpopscu, Lieut. Vacas, Lieut. Poly Zorileann, Lieut. (Ae. F. 587) Private. Bibesco, Prince (Ae. C. F. 20) Oznoth VLAICLU Monoplane. Designed by Ouvret Vlaiclu. First shewn at the Vienna Exhibition, 1911. Modified; it flew very well indeed at Aspern, June, 1912. The 1912 model is of entirely novel type, a tail first monoplane with a propeller either end of the main planes, and a triangular tail aft. Principal details are:--~Length~, 34-2/3 feet (10.50 m.) ~Span~, 30 feet (9.15 m.) ~Height~, 12 feet (3.65 m.) Wing frame in three sections with gap between. ~Motor~, 50 h.p., Gnome chain driven. ~Fuselage~, old style; landing chassis on three wheels only, with a single ash skid in front. Covered in engine driving the 31 foot propeller shaft for the 2 propellers. Rear tail consists of 2 fixed planes, a triangular damping plane and a triangular keel plane. Forward, an elevator and two semi-circular rudders (double faced). From this combination remarkable results are achieved, and all gyrostatic effect from the propellers eliminated. _Control_, horizontal wheel on column. Elevator depressed or otherwise by action on column. Note.--At Vienna, 1912, this machine took first prize for the smallest circle and also for accurate bomb-dropping. The original machine was purchased by the Roumanian Army. RUSSIAN. ~General Note.~--In the number of military machines and general attention to aviation Russia is only second to France. There are no effective machines of Russian design, but the Aviataka, Dux & Lomatuk firms build at home under foreign license, and there is also the Kennedy school (Anglo-Russian). ~Aerial Societies:~-- (Imperial) Aero Club. 1. Odessa branch. 2. Rostow and Don branch. 3. St. Petersburg " Finland Ae. C., Helsingfors. Kieff University Ae. C., Kieff. Moscow Ae. C., Moscow. Moscow Imp. Tech. College (Aviation Section). Riga Ae. C., Riga. Russian Aeronautical Society, St. Petersburg. Sevastopol Ae. C. Students' Aviation Club. Tomsk Ae. C., Tomsk. Volunteer Aerial Fleet. ~Aerial Journals:~-- _Aeronautical Journal of St. Petersburg._ _Aero_ (6, Liteiny, St. Petersburg). Weekly. _Dans l'Empire des Airs_ (7, Rota 26, Petersburg). Fortnightly. _Revue de Navigation Aérienne_ (7 rue Stremmiannaya, Petersburg). Weekly. _Sport_ (25, Ekaterineska, Odessa). _Wozdookhoplavatel_ (St. Petersburg). Monthly. _Wosduchoplawanie y Sport_ (Moscow). Monthly. ~Flying Grounds:~-- ~Gatchina Park.~-- Flying here under restrictions. V.F. school. ~Kieff.~--School for pilots. ~Kolomiaggi.~--Racecourse. ~Novo Therkask.~ ~Odessa.~ ~St. Petersburg.~--Kennedy school. ~Sevastopol.~--Volunteer Fleet school. ~Warsaw.~ ~RUSSIAN MILITARY AVIATION.~ ~Army Aviation.~ Early in 1912, under the presidency of the Grand Duke Alexander, the special school of the Volunteer Aerial Association was finally formed at Sevastopol for the winter and Gatchina for the summer. June 1912. Vote for 150 aeroplanes (140 to be built at home). Vote 1,050,000 roubles for new school at Tauride. November, 1912. Military trials results. (1) Sikorsky in a _Sikorsky_. (2) Haber in a _M. Farman_. (3) Boutmy in a _Nieuport_. December, 1912. Aeronautical school re-organised. Put under control of one commandant, one assistant, and four juniors. Course made seven months--15 pupils per school at a time. A one month course in aeroplanes, aerial motors, etc. Of the pupils, 10 will be selected for aeroplanes. New flying school established at Taskend in Turkestan. March, 1913. New schools established at Moscow, Odessa and Omsk. At the end of 1911 the total number of military aeroplanes was about 100. At the end of March, 1913, the total number was about 250, of which about 150 were modern. Principal types: _Albatross_, _Aviatik_, _Bristol_, _Deperdussin_, _Farman_, _Nieuport_, _Rumpler_, there being an average of 20 of each. The majority built under Russian license in Russia. The number of actual military pilots was 72. There is, however, a special volunteer corps of about 36 private aviators, bringing the available total to 108 or thereabouts. ~Navy Aviation.~ July, 1912. Lieut. Andreadi, 50 h.p. _Nieuport_, did a flight with stops from Sevastopol to St. Petersburg. September, 1912. Special naval aerodrome for hydro-avions ordered for Golodai Island, near Petersburg, bringing total of military and naval aerodromes to 6. _Sikorsky_ hydro-avion acquired. Also an _M. Farman_ ditto. New naval station projected at Libau. October, 1912. Naval purchase of several _Curtiss_ hydro-avions after trials at Sevastopol. At the end of March, 1913, the approximate effective force was as follows (all hydros, or capable of being so fitted): 1 _Astra_, 1 _Breguet_, 2 _Donnet-Leveque_, 1 _Farman_, 4 _Paulhan Curtiss_, 2 _Nieuport_ (50 h.p.), 1 _Sikorsky_. (A number of others on order.) Early in 1913 experiments were carried out with a combination of floats and skids, invented by M. Lobanoff, of Moscow. This proved equally effective on land or water. ~AVIATORS.~ The following are army, navy or volunteer aviators. The number is the Russian Ae. C., unless otherwise stated. F = French. Prefix + = killed. n = navy. Abramowitch Wissewold (14) Agababa, N. (668 F.) Agofonoff (20) Aleknovitch, G. (29) Alexandroff, D. (472 F.) n Andreadi, Lt. Artsgouloff (44) Avinass, J. (60) Badowski, L. Bakhmoutoff, N. (6) Berdchenko, V. (7) Bistritsky, V. (8) Boukshevden, Bar. G. (10) Boutmy (de), E. Campo, Scipio (211 F.) Childovski (67) Chioni, B. (250) Chimansky (27) Choudinoff (46) Dmitrieff, J. (9) Dorogouski (125 F.) Dougowezky, A. (1) n Dybovski, V. (12) Efimoff, M. (31 F.) Efimoff, T. Erdeli, G. (45) Eristov, Prince (524 F.) Evsukoff, P. (21) Firstemberg Flegfier, von. Gelgar (33) Glouchenko, S. (48) Godoulsky, A. (59) Gorghkoff, G. (626 F.) Goumberto-Dros, B. (58) Grekoff G. (5.) Grigoraschirilly (577 F.) Houeninsey, A. (227 F.) Husarenko (22) Illin, A. (16) Iougmeister (52) Jankovsky, G. (24) Joukoff (37) Kaidenoff (42) Kamensky, V. (66) Katzian, A. + Kauzminski (228 F.) Kebouroff, V. (210 F.) Kirchstern Kolchin, F. (28) Komaroff, M. (245 F.) Kostine, N. (223 F.) Kauznezoff, P. Kreiner, E. Kroumm, A. Lachtionoff, G. (57) Lambert (de) C. (8 F.) Lebedeff, V. (98 F.) Lerche, M. (25) Lewkowicz, H. (327 F.) Linno, G. (15) Lipowski, H. (330 F.) Kokteff (61) Makaroff, D. (13) Makeef, P. (5) Matyevitch, Matzevitch (152 F.) n+Matyevitch, Capt. (178 F.) Meybaum, T. Miller (35) Monakoff, (565 F.) Naidenoff, G. Naslennikoff, B. Nikiforoff (18) Nikolaieff (49) Nikolsky, P. (17) Oulianine, S. (181 F.) Pehanovsky, B. (401 F.) + Pietrowsky, G. (195 F.) Porcheron, J. (640 F.) Popoff, N. (50 F.) Poliakoff, A. (50) Poplavko (34) Pongolowski, W. (4) Pristchepoff (38) Raevsky, A. (F.) Raygorodsky, A. (207 F.) Rossinsky (68) n Rouaroff, M. (245 F.) Rynin, N. (23) Sakoff, N. de (627 F.) Salesky (41) Samoilo (11) Samouiloff, P. (51) Séméniovitch (226 F.) Semenko-Slavorossoff, H. (40) Semitan (36) Seversky-Prokofieff, N. (47) Sewkowicz, L. Shidloovsky, M. Shimansky, K. Shimkevitch, V. Sikorsky, I. (63) Skarginsky, A. (43) Slusarenko, W. + Smith, V. (231 F.) Sobansky Graf. (3) Soechnikoff, A. Soupnevsky, C. (26) Springuefeld Sredinsky, A. Strelmkoff (71) Tchemiakoff (72) Tkatcheff, V. (64) Tounochensky (32) Tselary, I. (54) Wassilieff, A. (225 F.) Zaikine (191 F.) Zelinsky, Col. (273 F.) + Zolotouchin, M. (31) ~CIVILIAN AVIATORS.~ There are very few purely civilian aviators in Russia. Russians who have obtained brevets include Mdlles Anarta (52), Golantchikova (55), Zvereva (30), Count de Lambert, (8 F.) and Count Malynski (209 F.) and one or two others. Few or none do any flying now. RUSSIAN AEROPLANES. ~A-Z~ AVIATIK. St. Petersburger Aviatik Gesellschaft, Petersburg. Construct Aviatiks. (See Germany.) BRONISLAWSKI. Experimental biplane with special stabilising features. DUX. Fabrica Moscovita Tneerskaja "Dux," Lastawa, Moscow. Construct under license. GELTOUCHOW. W. G. Geltouchow and A. W. Preiss, 4 Piasnitzkajai, Moscow. Constructs. GILBERT. C. Gilbert, 195 Twerskaja, Moscow. Constructs. KENNEDY. Soc. d. Dirigibles and Aeroplanes Kennedy, St. Petersburg. MOTOR. Riga-Sassenhof. RODJESTVEISKY. Built a triplane in 1911. RUSSIAN MILITARY DIRIGIBLES (13). -----------------------+------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+-------------------- | (1) | (2) | (3 & 4) | (5, 6, 7) | (8) | (9) | (10) | (11) | (12) | (13) Name | ~LEBEDJ.~ | ~KOMMISSIONY.~ | ~JASTREB~ and | ~ZODIAC VII,~ | ~PARSEVAL.~ | ~FORSZMANN I.~ | ~FORSZMANN II.~ | ~ASTRA 13.~ | ~PARSEVAL 14.~ | ~C. BAYARD 6,~ | | | ~GOLOUBJ.~ | ~VIII & IX.~ | | | | | | _bis._ Make | Lebaudy. | C. Bayard I. | Outchebny I & II. | | Parseval 7. | Forszmann. | Forszmann. | | | Date | ~1910.~ | ~1910.~ | ~1910-11.~ | ~1910-11.~ | ~1911.~ | ~1911.~ | ~1912.~ | ~1913.~ | ~1913.~ | ~1913.~ System | Semi-rigid. | Non-rigid. | Semi-rigid. | Non-rigid. | Non-rigid. | Non-rigid. | Non-rigid. | Non-rigid. | Non-rigid. | Non-rigid. -----------------------+------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+-------------------- ~Volume~ c. feet (m³.)| ~3700~ | ~3000~ | ~1500~ | ~2140~ | ~7600~ | ~800~ | ~600~ | ~9800~ | ~10,000~ | ~6200~ ~Length~ feet (m.)| 200 (61) | 184 (56.25) | ... | 164 (50) | 236 (72) | 121-1/2 (37) | ... | 259 (77.80) | 279 (85) | 250 (77.60) ~Diameter~ feet (m.)| 35-1/2 (10.80) | 34-3/4 (10.58) | ... | 29-1/2 (9) | 46 (14) | 19-3/4 (6) | ... | 49 (14.90) | 52-1/2 (16) | 42-3/4 (13) {fabric | Continental | Continental | ... | Continental | Continental | ... | ... | Continental | Reidinger | Continental ~Gas Bags~{ballonets | 1 | 1 | ... | 1 | 2 | ... | ... | 2 (3100 m³.) | 2 | 2 {compartments| 3 | 2 | 2 | ... | ... | ... | ... | ... | ... | ... ~Lift~ {total tons | 4 | 3-3/4 | ... | 2 | 7 | 1/2 | 1/3 | ... | ... | 7-1/2 {useful tons | 1-1/4 | 1 | ... | ... | ... | ... | ... | nearly 4 | about 3-1/2 | 2-3/4 ~Motor~ h.p.| 1-70 Panhard | 1-105 Clement B. | 1-75 E.N.V. | 1-60 Labor | 2-110 N.A.G. | 1-24 (=24) | ... | 2-150 Chenu | 2-180 Maybach | 2-130 Clement B. | (=70) | (=105) | (=75) | (=60) | (=220) | | | (=300) | (=360) | (=260) ~Propellers~ number| 2 | 1 | 1 | 1 | two 4-bladed | 1 | 1 | 3 | two 4-bladed | 2 ~Speed~ m.p.h. (km.)| 30 (49) | 33-1/2 (54) | 13 (21) | 33-1/2 (54) | 37 (59) | 23 (37) | ... | 36 (60) | 43 (68) | ... -----------------------+------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+-------------------- _Notes_ | _ex La Russie._ | _Jastreb_ reported | | | Carries 500 | | One-man | Carries 740 litres | | Special 2 speed | | wrecked, March, | | | litres of petrol. | | dirigible. | petrol. Crew 6. | | gear to propellers. | | 1913. | | | Has done 6-1/3 | | | Weights: | | | | | | | hours at 1500 | | |Crew: 1044 lbs. | | | | | | | metres, with 9 | | |Tools, &c. 220 " | | | | | | | on board. | | |Petrol, oil, &c. | | | | | | | | | | 7307 " | | | | | | | | | | ---- | | | | | | | | | | 8541 " | | | | | | | | | | ---- | | | | | | | | | |Forward propeller | | | | | | | | | |6m. diameter; the | | | | | | | | | |two after ones 3 m. | | | | | | | | | | each. | | -----------------------+------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+--------------------+-------------------- Note.--Illustrations see next page. [Illustration: Lebedj. UDS.] [Illustration: Jastreb (Outchebny).] [Illustration: Kommissiony. UDS.] [Illustration: FURSZMANN.] Note.--The other dirigibles are of usual type. See France and Germany. SERVIA. ~Military Aviation.~ At end of March, 1913, there were 7 aeroplanes, and 3 more (_Bleriots_) on order. SPANISH. ~Aerial Societies:~-- El Real Aëro Club de España (70 rue Alcala, Madrid). La Asociacion de Locomocion Aérea (20 Plaza de Cataluna, Barcelona). Real Aero Club d'Espana. Cataluna Ae. C. ~Aerial Journals:~-- _Boletin Oficial de la Asociacion de Locomocion Aérea_, 20, Plaza de Cataluna, Barcelona (monthly). _España Automovil_, 5, plaza de Isabel II, Madrid. Official organ, Spanish R. Ae. C. _Revista de Locomotion Aerea_, 20, Plaza de Cataluna, Barcelona (monthly). ~Flying Grounds:~-- ~Carbouchelle~ Military School. ~Army Aeroplanes.~ There are 9 old _Farmans_ (1910-11 model), and one or two more modern monoplanes: but little is doing. Some hydro-aeroplanes are on order for the Navy. ~AVIATORS.~ Military. Adaro, Lt. J. Alfaro, Lt. H. Arridaga, Capt. Berron, Lt. E. Echevarria, J. Gonzales, Capt. C. J. Granche Kindelan, Capt. A. Menendez, M. Ortiz, So. Lt. J. Penas, M. de las Pujo, Capt. (467 F) Private. Campano Dras, J. F. Jezzi, R. G. L. (British Ae. C. 44)[F] Lailhacar, de Pascal, Ferdinand Pimentel, B. L. Prince Alphonse d'Orleans (1) The following Spanish aviators have been killed:-- +---------------+ | 1909. | | Fernandez, A. | | | | 1911. | | Pola, M. | | Mauvais | | | | 1912. | | Bayo, Capt. | +---------------+ ~Military Dirigible Pilots.~ Herrera, Lt. E. Kindelan y Duany, Capt. A. Vives y Vich, Col. SPANISH DIRIGIBLES (Non-rigid). ESPANA. Military. (ASTRA class.) [Illustration] ~Maximum length~, 197 feet (60 m.) ~maximum diameter~, 35-1/3 feet (10.75 m.) ~volume,~ 43,057 c. feet4,000 m³. ~Total lift.~--9,700 lbs. (4,400 kgs.) ~Useful lift~, ? lbs. ( ? kgs.) ~Gas bags.~--Yellow coloured rubber proofed Continental fabric. ~Motor.~--One 100 h.p. 4-cylinder Panhard. ~Speed.~--29 m.p.h. ~Propellers.~--1, at the front end of the car, of wood, "Integrale" type. ~Steering.~--As in _Clement Bayard I_ and _Ville de Nancy_. Remarks.--The two side stabilising shapes are duplicated, as they are in the _Ville de Paris_. A webbing stretched on steel tubes is introduced between the inner edges of the 4 main stabilising shapes to provide extra stabilising surface. TORRES-QUEVEDO II. Military. +------------------+ | | | | +------------------+ ~Maximum length~, 147-3/4 feet (45 m.) ~maximum diameter~, 32-3/4 feet (10 m.) ~volume,~ 56,700 c. feet (1,600 m³.) ~Total lift.~-- ? lbs. ( ? kgs.) ~Useful lift~, ? lbs. ( ? kgs.) ~Gas bags.~-- ~Motor.~--60 h.p. Chenu. ~Speed.~-- ~Propellers.~-- ~Steering.~-- Remarks.--Designed by Captain Kindelan and Engineer Torres Quevedo. SWEDISH. ~(Revised by Lieut. DAHLBECK, R. Swedish Navy.)~ ~Aerial Societies:~-- Svenska Aëronautiska Sällskapet (Stockholm). Kungl. Automobil klubben: (Fenixpalatset, Stockholm). Svenska Motor-klubben: Aero sektion (Stockholm). ~Aerial Journals:~-- _Svensk Motor-Tidning_ (Fenixpalatset, Stockholm) Fortnightly. ~Flying Grounds:~-- ~Ljungbyhed~ (Skåne), sheds. ~Malmsl[~a]tt~, sheds. ~Military Aeroplanes.~ At the end of March, 1913, the Army possessed 1 monoplane, 1 biplane, and 2 biplanes building. The Navy had 1 _Bleriot_ type monoplane and 3 building. At the end of 1912 there were 9 privately owned aeroplanes. ~AVIATORS.~ (The number against any name is, unless otherwise stated, the Ae. C. Swedish pilot certificate.) Military. von Porat, Lieut. (6) Ljungner, Lieut. (7) Hamilton, Capt. (2) Naval. Dahlbeck, Lieut. (3) (British Ae. C. 120) Werner, Lieut. (9) Private. Cedarstr[~o]m, Baron C. (1) Fj[~a]llb[~a]ck (4) Ångstr[~o]m (5) Sundstedt (8) Thulin, M.A. (10) SWEDISH AEROPLANES. ASK. Monoplane. [Illustration: _Harlan_ type. Built by Ask, 1911.] NYROP. Naval Monoplane. [Illustration: _Bleriot_ 2-seater. Built in Sweden by Nyrop, 1911. ~Motor~, 50 h.p. Gnome.] DAHLBECK. [Illustration: _Farman_ type. Built by Lieut. Dahlbeck. 1913.] SWISS. (By our special Swiss editor.) ~Aerial Societies:~-- Aero Club Suisse (3, Hirschengraben, Berne). Sec.: F. Filliot. a Ostschweizerischer V. für L. (Zürich). b Sektion Mittelschwerz (Bern). c Sektion Westschweiz (Romande) (Lausanne). d Club Suisse d'Aviation (Geneva). Club Genêvois d'Aviation (Geneva). Sec.: P. Brasier. Flügsport Klub (Rorschach). Sec.: A. Zürn. ~Aerial Journals:~-- _Bulletin de l'Aero Club Suisse_ (Berne). Monthly. _La Suisse Sportive_ (16, Rue de Hesse, Geneva). Weekly. _Sport_ (35, Boulevard Exterieur, Berne). _Automobil Revue_ (Berne). Weekly. _Le Sport Suisse_ (Geneva). Weekly. _L'Auto Sport_ (Geneva). Weekly. _A.C.S._ (Swiss Aut. Clubs) (Geneva). Fortnightly. _Das Illustrierte Programm_ (Zurich). Fortnightly. _Revue Weinfelden._ Monthly. ~Flying Grounds:~-- ~Avenches.~ ~Collex-Versoix.~ (Club Suisse d'Aviation). ~Lucerne.~--60 acre park. Sheds. ~Petit Lancy.~ Geneva (Geneva Club). ~Dübendorf bei Zurich.~ ~Dirigible Station~ (with hangars):-- ~Lucerne.~ ~Army Aeroplanes.~ At the end of March, 1913, there were no army aeroplanes, a _Farman_ bought in 1911 having ceased to exist. ~Private Aeroplanes.~ Total at end of ~1910~ _about_ 10 " ~1911~ " 15 At the end of March, 1913, there were about ~15~ privately owned aeroplanes. ~AVIATORS.~ (The number against any name is, unless otherwise stated, the Ae. C. Suisse pilot certificate number.) + = killed. Military. Real, Lieut. T. (4) + Schmidt, Capt. J. Private. Audemars, E. (7) Bianchi, P. (6) Bider, O. (32) + Blane, M. (17) Bucher, M. (11) Burkard, H. (20) Burri, E. (24) Casser, E. (28) + Cobioni, E. (15) Domenjoz, J. (10) Durafour, F. (3) Failloubaz, E. (1) Grandjean, R. (2l) Gsell, R. (12) + Hösli, G. (25) Hug, M. (18) Ingold, K. E. (35) Jucker, A. (13) Kramer, H. (31) Mallei, A. (23) Parmelin, A. (22) + Primavesi, E. (34) Rech, E. (29) Rettig, J. J. (27) Reynold, M. (19) Ruchonnet, E. (5) Rupp, A. (9) Salvioni, C. (16) + Schmid, H. (14) Schumacher, J. (26) Taddoli, E. (2) Trepp, M. (30) Wyss P. A. (8) Züst, B. (33) SWISS AEROPLANES. [Illustration: Grandjean.] [Illustration: Taddeoli.] [Illustration: Wetterwald.] -----------------------------+-------------------+-----------------+------------------+ | ~GRANDJEAN.~ | ~TADDEOLI.~ | ~WETTERWALD.~ | Model and date. | Hydro-monoplane. | Monoplane. | Monoplane. | | ~1911-12.~ | ~1911-12.~ | ~1912.~ | -----------------------------+------------------ +-----------------+------------------+ ~Length~ feet (m.)| 33 (10) | 19-3/4 (6) | 24-1/2 (7.50) | ~Span~ feet (m.)| 33 (10) | 29-1/2 (9) | 33 (10) | ~Area~ sq. feet (m².)| 191 (18) | 151 (14) | 215 (20) | { total lbs. (kgs.)| 750 (340) | 880 (400) | 705 (320) | ~Weight~ { | | | | {useful, lbs. (kgs.)| 310 (140) | 330 (150) | ... | ~Motor~ h.p.| 50 Oerlikon | 50 Gnome | 40 E.N.V. | {max. m.p.h. (km.)| 62 (100) | 69 (110) | ... | ~Speed~ { | | | | {min. m.p.h. (km.)| 56 (90) | ... | ... | Number built during 1912 | 2 | 1 | 1 | -----------------------------+-------------------+-----------------+------------------+ TURKISH. ~Army Aeroplanes.~ There is a military aerodrome at S. Stefano, with Amerigo, Renzel and Thanlau as instructors. In March, 1913, there were about 12 monoplanes (_Harlans & Reps_), and one or two biplanes. Only one seems actually to have been used. Several other aeroplanes were captured during the war--generally in their packing cases unopened. In April, 50 machines were reported ordered in Germany. ~AVIATORS.~ Military. Fessa, Bey (780, F.) Kienan, Lt. (797, F.) Nouri, Lt. Ratzian Refik, Capt. Sismanoglou, J. URUGUAY. ~Aeroplanes in the country.~ _None._ ~AVIATOR:~ Cameo, M. Garcia U.S.A. (Edited by E. L. JONES, Editor of "Aeronautics," U.S.A.) ~General Note.~--In the early nineties, Professor Langley and the Bros. Wright were experimenting with heavier-than-air machines, but general interest in the subject is quite recent. Though some small dirigibles exist, American attention is mainly devoted to aeroplanes. Ballooning was quite the thing in 1907-11, but has languished. It is stated that there are certainly no less than _two thousand_ people in the U. S. A. who have built flying machines. The greater percentage of these have been home-made copies of standard machines. Individual builders of copies and freaks have diminished greatly in numbers, and there remains a few well-established manufacturers. Although inventors are still prolific in the Patent Office and clubs numerous, the general public takes very slight intelligent interest in aviation. The majority of clubs are inactive. In the year 1912 commercial development seemed to have great possibilities. The copyists were being weeded out and competent aeronautical constructors financed by adequate means began operations on systematic business lines. The latter half of the year saw a great slump. In the spring of 1913 prospects looked greatly improved, and there was generally increased activity. ~Aerial Journals:~-- ~Aeronautics.~--122, East 25th Street, New York. Monthly. ~Aircraft.~--37, East 28th Street, New York. Monthly. ~Fly.~--1701, Chestnut, Philadelphia, Pa. Monthly. ~Aero.~--Chicago, Ills. Weekly. ~Flying Grounds:~-- ~Belmont Park, N.Y.~--Old race track. Not very good. Scene of 1910 meet. 30 sheds occupied by few experimenters. ~Dayton.~--_Wright_ school private field. ~Chicago, Ills.~--Two fine fields. ~Fort Myer, Va.~--Government and private sheds. ~Hammondsport, N.Y.~--_Curtiss_ factory. Field (small) and lake for water planes. ~Los Angeles, Calif.~--Several fields in vicinity. Used for _Eaton_ school and private flyers. ~Marblehead, Mass.~--Poor field. Home of Burgess C. Fine for hydro-aeroplanes. ~Mineola, N.Y.~--_Moisant, Sloane_ and another school, and individuals. About 1 by 10 miles level field, without obstructions. ~Oakwood Heights, Staten I., N.Y.~--The Aeronautical Soc. grounds, on bay for use of hydro-aeroplanes. ~San Diego, Calif.~--Winter quarters _Curtiss_ camp; also used by army flyers. ~San Francisco~ (near).--Good. ~St. Louis, Mo.~--Kinloch Park. _Benoist_ school and private owners. ~U. S. A. AERO CLUBS.~ An attempt has been made here to give the name of every aero club that has been formed recently in the United States, or has been in existence for a long time. It is believed this list covers every club in the United States. Many of these clubs are nothing but a name. They were formed to conduct meets or exhibitions, given by the various aeroplane concerns engaged in this business. Many clubs are not incorporated. Others have no organisation, being run by principals of boys' schools or classes. Clubs even affiliated with the Aero Club of America have no members' meetings, nor have they in many cases even meeting rooms. There are but a half-dozen live aero clubs worthy the name in America. Three clubs own balloons, which are rented to members for ascensions. Little attempt is made by more than one or two associations to popularise aeronautics, to encourage experimenters, or to indulge in scientific work. The Aero Club of America, the Aeronautical Society and Aero Club of Illinois, are the principal organisations. The Ae. C. represents the F.A.I., and has a beautiful club house. The Aeronautical Society has rooms in the United Engineering Building, conducts well-attended lectures twice a month, and has grounds on Straten Island (for hydro-aeroplanes and aeroplanes). Clubs affiliated with the Ae. C. of America are marked * ~CALIFORNIA.~ New Orleans Aero Club, Wm. Allen, Sec., New Orleans *Aero Club of California, Prof. H. La V. Twining, Pres., 1308 Calumet St. Los Angeles. *Pacific Aero Club, Pacific Buildings, 331 Octavia Street, San Francisco Postal Aero Club, 305 W. Santa Clara Street, San Jose University of California Aero Club, T. W. Veitch, Sec., Berkeley Oakland Aero Club, Oakland *Aero Club of Colorado, 36 West Colfax Avenue, Denver, Col. Aero Club of Blackstonehill, Oakland, Calif, c/o W. R. Davis, Jr., 474 Prospect Street Curtiss Amateur Aviation Club, Harold Scott, Secretary, Los Angeles Santa Clara Valley Aero Club, Chamber of Commerce, San Jose Aero Club of San Diego, San Diego, Colonel C. C. Collier, Pres. Aero Club of Pasedena, W. J. Hogan, Pres., 635 Chamber of Commerce, Box 1054 ~CONNECTICUT.~ *Aero Club of Connecticut, Pres., A. Holland Forbes, at Fairfield Yale University Aero Club, New Haven Aero Club of Hartford, Hiram Percy Maxim, Pres., Hartford ~CUBA.~ *Aero Club de Cuba, Ignario 5, Havana ~DELAWARE.~ Aero Club of Delaware, Wilmington ~DISTRICT OF COLUMBIA.~ Washington Aero Scientific Club, F. L. Rice, Sec., c/o Y.M.C.A., Washington *Aero Club of Washington, Dr. Albert F. Zahm, Sec., Cosmos Club, Washington ~FLORIDA.~ Aeronautic Society of Florida, Davenport and Kerrison, Secs., 2014 Main Street, Jacksonville ~ILLINOIS.~ *Aero Club of Illinois, F. McCormick, Pres., 240 Michigan Avenue, Chicago Aeroplane and Kite Club, E. E. Harbert, Pres., 2852 N. Clark Street, Chicago University of Chicago Aero Club, Chicago *Aircraft Club of Peoria, c/o Leslie Lord, 505 E. Armstrong Street, Peoria Aeronautical Society of the University of Illinois, Urbana, R. Watts, Sec., 507 E. John Street, Champaigne ~INDIANA.~ Purdue Aero Club, Purdue University, Lafayette South Bend Aero Club, South Bend. *Aero Club of Indiana, Indianapolis ~KANSAS.~ Aero Club of Topeka, Topeka *Western Aero Association, E. S. Cole, Sec., Topeka Kansas State Aero Club, C. H. Lyons, Sec., Overland Park ~KENTUCKY.~ Continental Aero Club, Richmond ~LOUISIANA.~ Southern Aero Club, 809 Canal Street, New Orleans New Orleans Aero Club, Wm. Allen, Sec., New Orleans ~MARYLAND.~ *Aero Club of Baltimore, Col. Jerome H. Joyce, Pres., Baltimore ~MASSACHUSETTS.~ Aero Club of North Adams, North Adams *Aero Club of New England, A. R. Shrigley, Sec., 26 Trement St., Boston Amherst Aero Club, Amherst *Pittsfield Aero Club, L. J. Minahan, Pres., Pittsfield Springfield Aero Club, c/o Charles T. Shean, Pres., 3 John Street, Springfield Tufts College Aero Club, Tufts College *Harvard Aeronautical Society, Prof. A. Lawrence Rotch, Pres., Blue Hill Observatory Mass. Inst. of Technology Aero Club, John S. Selfridgem, Sec., Inst. of Technology, Boston Dartmouth Aero Club, Richard F. Paul, Sec., Dartmouth First Assn. of Licensed Pilots, Chas. J. Glidden, Pres., Hotel Somerset, Boston Williams Aeronautical Society, Williams College, Robert O. Starret, Sec., Williamstown ~MICHIGAN.~ *Aero Club of Michigan, C. B. du Charme, Sec., Detroit University of Michigan Aero Club, Ann Arbor ~MINNESOTA.~ Minneapolis Junior Aero Club, Stillman Chase, Sec., 3047 5th Avenue, S., Minneapolis St. Louis Experimental Ass'n., 5346 Zealand Street, St. Louis *Kansas City Aero Club, George M. Myers, Pres., Convention Hall, Kansas City ~MISSOURI.~ *Aero Club of St. Louis, 1429 Pine Street, St. Louis ~MONTANA.~ Aero Club of St. Charles College, Helena ~NEBRASKA.~ Aero Club of Nebraska, Col. Wm. H. Glassford, Pres., Fort Omaha Junior Aero Club or the Y.M.C.A., c/o Y.M.C.A., Omaha Lincoln Aero Club, Lincoln, c/o G. R. Brownfield, 1234 "O" Street Aviation Club of Nebraska, Arthur Frenzer, Sec., 2778 California Street, Omaha ~NEW JERSEY.~ Princeton University Aero Club, Princeton Aeronautic Society of New Jersey, c/o N.J. Automobile & Motor Club, Broad Street, Newark Aero Club of New Jersey, c/o James K. Duffy, Sec., 315 Madison Avenue, New York New Jersey Aeronautical League, W. A. Kraus, Sec., Guttenberg Aero and Motor Club, Asbury Park Atlantic City Aero Club, Col. Walter E. Edge, Sec., Atlantic City Model School Aero Club, Trenton, R. G. Teavitt, Sec. Trenton Aero Club, James Fenton, Sec., Trenton ~NEW YORK.~ *Aero Club of America, 297 Madison Avenue, Chas. Walsh, Sec. The Aeronautical Society, 250 W. 54th Street, Arnold Kruckman, Gen. Sec. Aeronautic Alumni Ass'n., c/o West Side Y.M.C.A., West 57th Street New York Model Aero Club, Adrien Lacroix, Sec., 141 Lexington Avenue National Model Aero Club, c/o A. Leo Stevens, 282 9th Avenue Stuyvesant Aeronautic Society, 345 East 15th Street, Percey W. Pierce, Sec. Columbia Aero Club, Columbia University, 116th Street Dewitt Clinton High School Aero Club, 58th Street and 10th Avenue *Aero Club of Buffalo, Lafayette Hotel, Buffalo, N.Y. Thousand Islands Aero Club, c/o Dr. J. M. Gibbons, 168 Montague Street, Ithaca Aeronautic Section, Technology Club, Syracuse Boys' High School Aero Club, Henry St. Pieless, Sec., 815 Avenue, J., Brooklyn *Rochester Aero Club, c/o L. J. Seely, 10 Culver Road, Rochester Aero Club of the Y.M.C.A., Harold C. Carpenter, Pres., White Plains Aero Club, Haliano, U.S.A., 135, West 12th Street, N.Y. Seventy-two members. C. Chiantelli, Sec. Junior Aero Club, c/o A. E. Horn, Public School, 77 Park Avenue and 84th Street Aero Club of Long Island, c/o Hohn H. Lisle, Alen Cove Commerce Aero Club, 65 West 117th Street *Aero Club of New York, Garden City. Mechanics Aeronautical Ass'n., c/o H. H. Simms, 304 Cutler Building, Rochester Aeronautical Research Club of the Y.M.C.A., H. C. Myers, Sec., Buffalo Aero Club Italiano, Saverio A. Mascia, 403 Park Avenue Aeronautical Society of Women, Miss Dorothy E. Ball, Sec., 250 West 54th Street ~OHIO.~ *Aero Club of Ohio, Canton *Aero Club of Dayton, Dayton International Aeroplane Club, Dayton Cleveland Aero Club, C. J. Forbes, Sec., Hollanden Hotel, Cleveland *Aero Club of Cincinnati, c/o P. L. Mitchell, Traction Buildings, Cincinnati ~OREGON.~ Portland Aero Club, E. Henry Wemme, Pres., Portland ~PENNSYLVANIA.~ Aviation Section, Professional Chauffeurs Ass'n. of America, 1933 Spring Gardens, Phil. *Aero Club of Pennsylvania, Rev. Geo. S. Gassner, Sec., Betz Buildings, Phil. Ben Franklin Aeronautical Ass'n., c/o Dr. T. Chalmers Fulton, 6th and Diamond Street, Phil. Philadelphia Aeronautical Recreation Society, Dr. Thos. E. Eldridge, Pres., 1639 N. Broad Street, Phil. Haverford College Aero Club, Haverford, Pa. Swartmore College Aero Club, Swartmore, Pa. Univ. of Penn. Aero Club, Univ. of Penn., Phil., Pa. Aero Club of Carnegie, Tech. Schools, Pittsburg, Pa. Intercollegiate Aeronautical Ass'n., Geo. A. Richardson, Pres., Univ. of Penn., Phil. Pittsburg Aero Club, H. P. Haas, Sec., Magel Buildings, Pittsburg, Pa. ~RHODE ISLAND.~ Pawtucket Aero Club, Pawtucket Rhode Island Aeronautical Society, Providence, John J. Long, Sec., c/o Brown University ~TENNESSE.~ Nashville Aero Club, Nashville, E. Fisher Coles, Sec. ~TEXAS.~ Dallas Aero Club, c/o Chamber of Commerce San Antonio Aero Club, c/o Dr. Fred J. Fielding, 423 Hick's Buildings, San Antonio South Western Aero Club, P.O. Box 821, Fort Worth Texas Junior Aeronautical Ass'n., Hugh Dumas, Pres., Fort Worth ~UTAH.~ Aero Club of Utah, c/o L. R. Culver, 11 Eagle Block, Salt Lake City Salt Lake City Aero Club, c/o Mr. Campbell, Walker Bank Buildings, Salt Lake City ~VERMONT.~ Aero Club of Vermont, Chas. T. Fairfield, Pres., c/o Rutland News, Rutland ~VIRGINIA.~ University of Virginia Aero Club, Stanford Swin, Sec., University of Virginia Virginia-Tennesse Aero Club, Bristol, Va-Tenn, C. W. Morey, Sec. ~WASHINGTON.~ Aero Club of Washington, 415 Union Trust Buildings, Washington, D.C. Aero Club of Seattle, c/o M. Robert Guggenheim, 511 Lonan Buildings, Seattle Walla Walla Aero Club, Walla Walla ~WISCONSIN.~ *Milwaukee Aero Club, Milwaukee, c/o Major Henry B. Hersey, Chief of the Weather Bureau, Milwaukee Milwaukee Aeronautic Society, Pres., Sherman Brown, Manager of Davidson Theatre, Milwaukee ~U.S.A. MILITARY AVIATION.~ ~U. S. ARMY AEROPLANE SPECIFICATIONS. (1912).~ ~SPEED SCOUT MILITARY AEROPLANE.~ (1) Carry one person with the seat located to permit of the largest possible field of observation. (2) Ascend at the rate of 1500 feet in three minutes, while carrying fuel for one hour's flight. (3) Carry fuel for a three hours' flight. (4) Must be easily transportable by road, rail, etc., and easily and rapidly assembled and adjusted. (5) The starting and landing devices must be part of the machine itself, and it must be able to start without outside assistance. (6) The engine must be capable of throttling. (7) The engine will be subject to endurance test in the air of two hours' continuous flight. (8) Speed in the air of at least 65 miles an hour. (9) Capable of landing on and arising from ploughed fields. (10) The supporting surfaces must be of sufficient size to insure safe gliding in case the engine stops. (11) The efficiency and reliability of the system of control must have been demonstrated before the purchase order is placed. The aeroplane must be capable of executing a figure eight within a rectangle 500 yards by 250 yards, and without decreasing its altitude more than 100 feet at the completion of the figure eight. This test to be made by aviator alone without carrying extra weight. (12) The extreme width of the aeroplane supporting surfaces must not exceed 40 feet. ~SCOUT MILITARY AEROPLANE.~ (1) The aeroplane must carry two persons with seats located to permit of the largest possible field of observation for both. (2) The control must be capable of use by either operator from either seat. (3) The machine must be able to ascend at least 2000 feet in ten minutes while carrying a weight of 600 lbs. including the aviator and passenger, 150 lbs. of gasoline, and extra weight to make 600 lbs. All of the extra weight must be carried on the engine section and not distributed over the wings. (4) The fuel and oil capacity must be sufficient for at least four hours continuous flight. This will be determined by a trial flight of at least one half-hour, measuring the consumption of gasoline while carrying the passenger and weight stated in paragraph 3. (5) Same as No. 4 above. (6) Same as No. 5 above. (7) The engine must be of American manufacture and capable of throttling to run at reduced speed. (8) Same as No. 7 above. This test will be made with aviator and passenger, extra weight and fuel enumerated in paragraphs 3 and 4. (9) The aeroplane must develop a speed in the air of at least forty miles an hour. This test will be made with aviator and passenger, extra weight and fuel enumerated in paragraphs 3 and 4. The maximum speed must not exceed sixty-five miles per hour. (10) Same as No. 9 above. This test will be made with aviator, passenger, extra weight and fuel enumerated in paragraphs 3 and 4. (11) Same as No. 10 above. (12) Same as No. 11 above. (13) Same as No. 12 above. In ~1913~ additional requirements specified enclosed body, bullet-proof armour, .75 chrome steel, for engine and aviator, provision of necessary instruments and wireless, with, as desirable features, silencer and cut-out, self-starter and an efficient stabilising device. At end of March, 1913, the effective Army aeroplanes consisted of three 50 h.p. _Wrights_, one _Wright-Burgess_, several old machines. The Navy had two _Wright-Burgess_ hydros and a few nondescripts. A _Burgess_ flying boat since added. The estimate for Army effectives at end of the present year (1913) is 21 (5 _Burgess_, 6 _Curtiss_, 10 _Wright_). ~AVIATORS.~ (The numbers after any name is the number of the U. S. Aero Club certificate.) Army. Arnold, Lieut. H. H. (29) Beck, P. Capt. (39) Brereton, Lt. L. H. (211) Burge, Corp. V. S. (154) Chandler, C. de F. Capt. (59) Foulois, Lieut. (140) Geiger, Lieut. H. (166) Goodier, Lt. L. E. (200) Graham, Lieut. H. (152) Hennessy, Capt. F. B. (153) Humphreys, Lieut. Kirtland, Lieut. R.C. (45) Lahm, Lieut. F. P. (2) Love, Lieut. M. L. (155) McClaskey, Lieut. J. W. (90) McKay, Capt. G. W. (67) McLeary, Lieut. S. H. (210) McManus, Lieut. Milling, Lieut. (30) Rodgers, J. Lieut. (48) Sherman, Lieut. W. C. (151) Winder, Lieut.-Col. C.B. (130) Navy. Herbster, Ens. (103) Ellyson, Lieut. T. G. (28) Rodgers, John, Lieut. Towers, Lieut. J. H. (62) ~U.S.A. PRIVATE AVIATORS (to end of 1911).~ (The number against any name is, unless otherwise stated, the Ae. C. America pilot certificate number. Only a few American aviators have bothered to obtain the Ae. Certificate. America produces a large number of aviators who fly for pleasure or exhibitions only and have not gone into competitions under International Rules. These consequently do not bother about certificates; but most of those recorded could easily obtain them, if they cared to try.) Adams, Clarence Adams, A. S. (215) Alvarez, F. Ambrose, Charles Andrews, Thornwell Apto, H. J. Arndt, Edw. F. Atwater, Mrs. L. J. Atwater, W. B. (98) Atwood, H. N. (33) Baker, G. H. Baldwin, Ivy Baldwin, Capt. T. S. (7) Barnett, A. E. Barton, Sam Bates, M. F. (66) Beachey, Hillery (89) Beachey, Lincoln (27) Beatty, G. W. (41) Beckly, Wm. A. Beers, W. C. (40) Benoist, T. W. Bergdoll, Louis, J. Betton, Kaid Bishop, Cortland Bleakley, W. H. Boandette, A. B. Bonner, G. T. Bonette, C. C. Bonney, L. W. (47) Brackett, A. J. Brewer, Roy Brindley, O. A. (46) Brinker, H. S. Brodie, O. W. (135) Brookins, W. R. (19) Brown, H. H. (58) Bumbaugh, Capt. G. L. Burgess, W. Starling (136) Burligh, Chas. Bush, J. F. Butler, P. J. Callon, J. L. (102) Champion, Frank (86) Christmas, Wm. Cannon, Jack Cline, W. F. Coffyn, F. C. (26) Cole, R. Coleman, R. F. Cook, W. B. (95) Cooke, Henry C. Cooke, F. G. (26) Cooper, John D. (60) Costello, A. B. Coutourier, C. (79) Crewelson, W. H. Cross, Redmond W. (35) Crosby, R. W. Cummings, J. A. Curtiss, Glenn H. (1) & (Ae. C. F. 1) Curzon, J. W. DeGiers, C. De Hart, D. C. De Kor, F. (72) Dennis, D. L. Dixon, S. D. Dougherty, E. S. (87) Doyle, H. Drew, A. (50) Drexel, J. A. (8) Durgan, W. E. Dyott, G. M. Eaton, Warren Ecot, Robert G. Eells, Fred. Elton, Albert (75) Engel, A. J. Erickson, Louis, G. Eshoo, D. Evans, W. Ey, G. Fish, Farnam (85) Fortney, Lewis Fowler, R. G. Freeman, A. (84) Fuchs, Joseph Funk, T. B. Gallaudet, E. F. (32) Games, A. B. Gantz, Saxe P. Gardener, Hubbard G. Garner, R. W. Gaskell, Bud Gratz, H. F. Gray, George Green, William, Dr. Gregory, Donald Greider, C. Greider, J. Gressier, Romaine Guey, Fung Joe Hadley, C. O. Hall, Hamilton, C. K. (12) Hamilton, J. W. Hamilton, Thos. W. Hammond, Lee (34) Harper Harkness, H. S. (16) Harmon, C. B. (6) Hartman, A. Haupt, Willie Havens, Beckwith (127) Hendrian, A. Henning, J. C. Henningsen, Fred Heth, Eugene Henry, R. St. Hilliard, W. M. (Brit. Ae. C. 102) Hills, H. V. Hofer, W. Hoff, Wm. H. (91) Hoflake, Charles Holden, J. J. Holt, L. E. (63) Hoover, Fred. (100) Hoover, H. H. Huddleston, E. D. James, Stanley Janicke, W. Jannus, Anthony (80) Jennings, J. C. Jerwan, S. S. (54) Johnson, Frank H. Johnson, Walter E. (164) Jumel, August Kantner, H. (65) Kellrey, H. Kemmerle, Horace Kennedy, F. M. (97) Kiley, J. E. Kimball, Wilbur R. Klein, H. H. Klockles, J. G. Korn, Edward Krasting, Theodore La Chapelle, Duval Lambert, A. B. (61) Lambreath, C. E. Lapadat, N. Laser, G. F. Le Van, Howard Lewis, S. C. (92) Lewkowicz, Ladis Lidstone, Ed. S. Lillie, M. T. (73) Lockwood, Chas. Longfellow, H. W. Loose, Geo. H. Lougheed, A. Longo, T. Ludwig, Vandy Maier Manners, George Mars, J. C. (11) Martin, J. B. Martin, G. L. (56) Martin, J. V. Massar, A. M. Masson Matalach, S. H. Mattingley, O. A. Maynard, Arthur Mayo, Albert (99) McCally, J. B. (94) McCarty, James McClellam McCollum, W. C. McCurdy, J. A. D. (18) McGoey, Thomas McNamara, Geo. E. McManus, L. McMahon, A. J. Medrick, F. H. Meyerhoffer, Orvar Miller, Clinton R. Moisant, Miss M. E. (44) Morok, Chas. B. Mourfield, Carl Murias, De E. F. (38) Murphy, T. Murphy, Wm. Neidmiller, Ed. Nelson, N. B. Nelson, Nels. T. Ovington, E. L. Page, P. W. (68) Paine, N. B. Paridon, Michael Park, Henry Paulding, Dwight Paulhan, L. (3) Pfiel, P. Post, Augustus Powers, H. W. Prince, Norman (55) Prentice, Prospect, Louis Prowse, C. O. Raiche, Mrs. F. Ragot, Louis Reichert, H. D. W. (82) Remington, Earle Reynolds, Dr. Percy, L. Richter, J. (81) Riggs, E. Roat, Arthur R. Robinson, H. (42) Roehrig, B. F. Rowe, F. E. Russell, Geo. Sackett, Harry Sands, H. Hayden (Ae. C. F. 70) Schafer, G. E. Schmidt, G. S. Schneider, Fred, P. Schulz, G. C. Schwartz, A. Schwister, John Scott, Miss B. Seeman, J. R. Seignor, H. A. Seligman, J. (64) Seymour, Joseph Sellers, M. B. Shelton, T. Sherwood, Oliver, B. Shneider, Fred. Shoemaker, Chas. W. (93) Sill, F. Simmonds, O. G. (145) Skinner, S. R. Slaik, E. Slavin, J. J. Smith, A. Smith, Kyle Smith, R. M. Sommerville, W. E. Soreusen, Prof. Sparling, J. N. Steitz, F. M. (88) Stewart, J. G. Stone, A. (Ae. C. F. 15) Summer, Gill. Suppe, Talmage, M. P. Takisow, Tarbox, J. Thomas, W. T. Thomas, O. W. Thompson, George Tickell, Sam Timothy, S. R. Troxey Turpin, J. C. (22) Tuttle, T. T. Vanderbilt, W. K. Vaughan, Stanley Vogt, Jesse S. Walden, Dr. H. W. (74) Walker, Clarence Ward, J. J. (52) Warner, A. P. Webster, C. L. (69) Weeks, F. W. Wells, G. Wetzig, H. H. Weymann, Charles (14) Wilcox Wildman, Dock Willard, C. F. (10) Williams, Beryl (71) Williams, B. J. Willoughby, Capt. Hugh L. Wilson, Edward Wiseman, Fred. E. Witmer, C. C. (53) Worden, John H. (76) Wright, Orville (4) (Ae. C. F. 14) Wright, Wilbur (5) (Ae. C. F. 15) Young, C. M. Yan, J. The following American aviators have been killed:-- +-----------------------+ | 1908. | | Selfridge, Lt. (Army) | | | | 1910. | | Johnstone, R. (20) | | Moisant, J. B. (13) | | | | 1911. | | Badger, Wm. R. (36) | | Castellane, Tony | | Clark, C. B., Dr. | | Dixon, Cromwell (43) | | Ely, Eugene | | Frisbie, J. J. (24) | | Hoxsey, Arch. (21) | | Johnston, St. Croix | | Kelly, Lieut. (Army) | | Kreamer, Dan. A. | | Miller, F. H. | | Oxley | | Penot, Marcel | | Purvis, Wm. G. | | Rosenbaum, Louis | | Schriver, Tod (9) | +-----------------------+ ~U.S.A. PRIVATE AVIATORS. (Brevets, 1912.)~ Aldasoro, J. P. (217) Aldasaro, E. A. (218) Andrews, W. D. (124) Arnold, G. (198) Barlow, F. E. (139) Beckwith, S. F. (137) Beech, A. C. (168) Belcher, O. T. (158) Bell, Dr. F. J. (196) Bell, G. E. (201) Bergdoll, G. C. (169) Berlin, C. A. (109) Bleakley, W. H. (206) Bouldin, W. (157) Boysdorfer, C. (193) Brown, R. M. (185) Bryant, G. M. (208) Burnside, F. H. (212) Carlstrom, O. G. (145) Colovon, P. (160) Crossley, S. J. (187) Dalwigk, G. B. (190) De Hart, D. C. (129) Eaton, W. S. (128) Edelman, D. (191) Elliott, R. (178) Figyelmessy, H. (203) Fritts, E. V. (213) Gilpatric, J. G. (171) Gray, G. A. (142) Gray, J. F. (150) Gunn, T. (131) Hattemer, H. L. (147) Hemstraught, W. H. (146) Hetlick, W. A., jr. (197) Hild, F. C. (216) Hunt, E. N. (163) Holmes, H. (204) Johnson, R. R. (205) Kabitzke, W. (126) Kammski, J. G. (121) Kemper, F. W. (119) Klockler, J. G. (125) Korn, E. (171) Lamkey, W. A. (183) Law, R. B. (188) Maroney, T. T. (106) Masson, D. (202) McMillen, R. E. (111) Meyer, C. (176) Miller, B. A. (173) Niles, C. F. (181) Park, H. (113) Peoli, C. (141) Piceller, W. (116) Prodgers, C. B. (159) Reid, M. E. (114) Reid, P. H. (179) Remer, L. H., de (115) Richardson, R. H. C. (174) Robinson, R. W. C. (162) Ruiz, H. (182) Russell, R. B. (132) Salinas, A. (170) Salinas, G. (172) Schaeffer, J. S. (177) Scholovinck, E. (195) Schuman, F. J. (143) Singh, M. M. (123) Sjolander, C. T. (138) Smith, J. F. (207) Spaulding, J. D. (107) Stark, W. M. (110) Stinson, K. (148) Sverkerson, J. S. (180) Tait, G. M. (184) Takeiski, K. (122) Terrill, F. J. (108) Thomson, C. (112) Thompson, De L. (134) Twombly, W. I. (149) Vought, C. M. (156) Waite, H. R. (186) Weeks, E. O. (214) Weiner, T. (167) Wiggins, C. L. (175) Wood, C. M. (209) U.S. Aviators killed: _Continued._ +---------------------------+ | In ~1912.~ | | | | Blair, R. | | Chambers, W. B. | | Clarke, J. (133) | | Gill, H. W. (31) | | Hazelhurst, Lieut. | | Kearney, H. F. (83) | | Kondo, M. (120) | | Lawrence, C. | | Longstaffe, J. L. | | Mitchell, L. (51) | | Page, R. (96) | | Parmelee (25) | | Peck, P. (57) | | Quimby, Miss H. (37) | | Rodgers, C. P. (49) | | Rockwell, Lt. L. C. (165) | | Scott, Corp. F. | | Southard, F. J. | | Stevenson, J. | | Turner, H. | | Underwood, G. | | Walsh, C. F. | | Welsh, A. L. (23) | | | | In ~1913.~ | | | | Boland, F. E. | | Chandler, Lieut. R. | | Park, Lieut. T. D. (223) | +---------------------------+ U.S.A. AEROPLANES. ~A~ AERIAL EXHIBITION Co. (Biplane), 1777, Broadway, New York. Built a _Curtiss_ type with Kirkham motor, 1911. 2 skids, with wheel between, and usual _Farman_ rubber shock absorbers. AERIAL YACHT CO., San Francisco. Inc. 1913. Capital, $25,000. AERONAUTICAL SUPPLY CO. See _Cordeaux-Etter_. AMERICAN AEROPLANE SUPPLY HOUSE (Monoplane), 266, Main Street, Hempstead, N.Y. Builders of monoplanes after the _Bleriot_ type. Half-a-dozen machines were built and sold during 1911. Fitted with Gnomes or American engines. ~B~ BALDWIN Biplanes. Captain Thos. S. Baldwin, PO Box, 78, Madison Square, N.Y. About half-a-dozen steel biplanes have been produced in 1911 by Captain Baldwin, and he and other aviators, Badger, Hammond, Miss Scott Mass, etc., have flown these at various exhibitions and meets, and are classed with well-known successful American biplanes. [Illustration: _Photo, Edwin Levick, N.Y._] Details of _Baldwin_ ("Red Devil"). ~Length.~--28-1/4 feet (8.60 m.) ~Span.~--28-3/4 feet (8.75 m.) ~Motor.~--50-60 h.p. Hall-Scott ~Propeller.~--One Requa-Gibson in rear of main planes. Diameter, 7 feet (2.13 m.) Pitch, 6 feet (1.82 m.) ~Speed.~--60 m.p.h. (97 k.p.h.) [Illustration: BALDWIN. RED DEVIL. UAS.] BENOIST. Benoist Aircraft Co., 6628, Delmar Boulevard, St. Louis, Mo. (formerly Aeronautic Supply Co.) -----------------------------+------------------+------------------+ | ~1912-13.~ | ~1913.~ | Model and date. | "Headless." | Flying boat. | | | Tandem biplane. | -----------------------------+------------------+------------------+ ~Length~ feet (m.)| 22-1/2 (6.85) | 27 | ~Span~ feet (m.)| 30 (9.15) | 42-1/6 (12.80) | ~Area~ sq. feet (m².)| ... | ... | {total lbs. (kgs.)| ... | 1004 (455) | ~Weight~ { | | | {useful lbs. (kgs.)| ... | ... | ~Motor~ h.p.| ... | 75 Roberts | {max. m.p.h. (km.)| 68 (110) | ... | ~Speed~ { | | | {min. m.p.h. (km.)| 31 (50) | ... | ~Endurance~ hrs.| 3 | | -----------------------------+------------------+------------------+ Notes.--The boat of the flying boat is 23-5/6 feet long, by 2 feet 2-1/2 inches wide. Shipable wheels. See _Aeronautics_, January, 1913. [Illustration: BENOIST. Flying boat. UAS.] BOLAND. Boland Aeroplane & Motor Co., 1821, Broadway, New York. Works: Ft. Center St. Newark, N.J. [Illustration] ----------------------------+------------------+ Model and date. | ~1913.~ | | "Tailless." | ----------------------------+------------------+ ~Length~ feet (m.)| 21-1/6 (6.45) | ~Span~ feet (m.)| 35-1/2 (10.80) | ~Area~ sq. feet (m².)| ... | {total lbs. (kgs.)| 900 (408) | ~Weight~ { | | {useful lbs. (kgs.)| ... | ~Motor~ h.p.| 60 Boland | ~Speed~ m.p.h. (km.)| 60 (95) | Number built during 1912 | 1 | ----------------------------+------------------+ A refinement of the original machine of the late F. E. Boland, which first flew in 1911. _Control_ by two special jibs which work inward. Designed to be used also as a hydro, with three step floats. No rudder or ailerons. Full details, etc., see _Aeronautics_, U.S.A., May, 1913, and _Aircraft_, U.S.A., May, 1913. BURGESS. Burgess Co. & Curtis, Marblehead, Mass. Built _Wright_ types under license, also machines of their own. ----------------------------+----------------------------+----------------------------+---------------------------- Model and date. | Military tractor. | Coast defence hydro. | Naval flying boat. | ~1912-13.~ | ~1913.~ | ~1913.~ ----------------------------+----------------------------+----------------------------+---------------------------- ~Length~ feet (m.)| 37-3/4 (8.50) | 33-1/3 (9.55) | 31 (9.45) ~Span~ feet (m.)| 34-1/2 (10.50) | 37-3/4 (12) | 43 (13.10) | | | -- ----- | | | 36 (10.97) ~Area~ sq. feet (m².)| ... | ... | 397 (37) {total lbs. (kgs.)| ... | ... | ... ~Weight~ { | | | {useful lbs. (kgs.)| ... | 775 (352) | ... ~Motor~ h.p.| 70 Renault | 60 Sturtevant | 70 Renault | | _muffled_ | ~Speed~ m.p.h. (km.)| 45 (70) | 59 (95) | ... ~Endurance~ hrs.| 4-1/2 | 4-1/2 | ... Number built during 1912 | ... | ... | ... ----------------------------+----------------------------+----------------------------+---------------------------- Remarks.-- | Lumina fabric. | Special clear view | Boat 29-1/2 feet long. | Single screw. | for observation. | 2--2 step floats. | Details, _Aeronautics_, | 2--1 step mahogany | Petrol, 48 gallons. | (U.S.A.), May-June, | and copper floats. | Details, _Aeronautics_, | 1912. | Useful weight | (U.S.A.), May, 1913. | | includes floats. | | | Details, _Aeronautics_, | | | (U.S.A.), Feb., 1913. | ----------------------------+----------------------------+----------------------------+---------------------------- [Illustration: Burgess-Wright.] [Illustration: Burgess-Wright as a hydro (the U.S. Navy has two of these).] [Illustration: Military tractor. _By favour of "Aeronautics," U.S.A._ UAS.] [Illustration: "Coast defense" hydro. _From "Aeronautics."_] [Illustration: Burgess-Curtis. 1913 Naval flying boat.] ~C~ CHRISTMAS. Durham Christmas Aeroplane Sales & Exhibition Corporation, Inc. 1913. Capital: $10,000 to $50,000. Claims for it are that it is "automatically balanced." This is attained by the shape of the machine, not through the agency of any auxiliary apparatus. [Illustration] CORDEAUX-ETTER. Cordeaux-Etter Mfg. Corporation, Brooklyn, N.Y. Capital: $10,000. Took over, 1913, the Aeronautical Supply Co., of N.Y. COOKE. Weldon B. Cooke Aeroplane Co., Sandusky, Ohio. Founded 1913 by the well-known aviator, W. B. Cooke. [Illustration] ---------------------------+------------------+ Model and date. | ~1913.~ | ---------------------------+------------------+ ~Length~ feet (m.)| 25 (7.60) | ~Span~ feet (m.)| 24 (7.30) | ~Area~ sq. feet (m².)| 240 (22) | {total lbs. (kgs.)| 750 (340) | ~Weight~ { | | {usefullbs. (kgs.)| ... | ~Motor~ h.p.{|75 Roberts 2 cycle| {| _upside down_ | ~Speed~ m.p.h. (km.)| ... | Number built during 1912 | new firm | ---------------------------+------------------+ Details, _Aeronautics_, U.S.A., February, 1913. [Illustration: COOKE. UAS] CURTISS. Curtiss Aeroplane Co., Hammondsport, N.Y. Glenn H. Curtiss in 1907 and 1908 was a member of the Aerial Experiment Association, formed by Dr. and Mrs. Alexander Graham Bell. This Association built four machines, each along the lines of one of the four engineers belong to the Association, F. W. Baldwin, Lieut. T. E. Selfridge, G. H. Curtiss and J. A. D. McCurdy. The last built was the _June Bug_, designed by Curtiss and was the most successful. In the spring of 1908, the Association was disbanded and The Aeronautical Society gave Curtiss an order for an aeroplane with _carte blanche_ as to design. He produced a 4 cyl. machine, Curtiss engine, and flew it. A duplicate was hurriedly built, 8 cyl. engine installed, and taken to Europe for the first Gordon Bennett, which he won. Returning, the same type was continued with minor improvements. Later the front elevator was brought closer in, finally discarded, and the fan tail adopted and this remains the standard land machine to-day. In April, a military tractor was built and flown. On January 26th, 1911, first successful flights were made with a hydroaeroplane, at the Winter camp at San Diego, Calif. This had two floats tandem. One was finally adopted and great success was achieved, and remains standard at the present time. With this machine various experiments were made. It was altered in a tractor for one occasion, it was lifted on board warships; made into triplane, etc. In 1912 he brought out his present type of flying boat. This is being rapidly developed and minor changes in details are made in practically every machine put out. In May, 1913, he produced a special 4-passenger flying boat for a customer on special order. Note.--In addition to those tabulated, special small racing machines have been built, as well as similar machines with extra sections simply added either side for Army use. ---------------------------+--------------------+----------------------+-------------------- Model and date. | ~Type D.~ | ~Type E.~ | ~Type F.~ | ~1913.~ | ~1913.~ | ~1913.~ ---------------------------+--------------------+----------------------+-------------------- ~Length~ feet (m.)| 26-2/3 (8.10) | 27-1/3 (8.33) | 27-1/3 (8.33) ~Span~ feet (m.)| 26-1/4 (8) | 31-1/4 (9.50) | 38-1/3 (11.70) ~Overall~ feet (m.)| 33-1/12 (10) | 36-1/4 (11) | 41-2/3 (12.70) ~Area~ sq. feet (m².)| 214 (19-1/2) | 288 (26-1/4) | 421-1/2 (39) {total lbs. (kgs)| ... | 1700 (771) | ... ~Weight~ { | | | {useful lbs. (kgs)| ... | 500 (227) | ... ~Motor~ h.p.| Curtiss | 80 Curtiss | Curtiss ~Speed~ m.p.h. (km.)| ... | 59 (95) | ... ---------------------------+--------------------+----------------------+-------------------- Remarks.-- | Land service, but | Fitted either with |Used to date only |is also made fitted | wheels, pontons, or |as military tractor | with floats. | boat. |or heavy flying boat. | Panels. | _Vilas boat._ | _McCormick boat._ | | Boat 24 ft. long. |Boat 25 ft. long 4 ft. | |Beam 54-1/2 ft. long. |wide. Freeboard 46 | |Height 41 ins. long. |ins. Cockpit 84 ins. | |Cockpit 3 ft. long by |long by 46 ins. wide. | | 4 ft. 2 ins. wide. |Length of tail, incl. | | | elevator 12 feet. ---------------------------+--------------------+----------------------+------------------ For full details of the tractor (F) see _Aeronautics_, U.S.A., February, 1913. [Illustration: 1913 Tractor. Type F.] [Illustration: 1912 flying boat. _By favor of "Aeronautics," U.S.A._] [Illustration: Curtiss. 1913 flying boat. UAS.] ~G~ GALLAUDET. Gallaudet Eng. Co., Norwich Ct. [Illustration] In 1912 produced a special racer as above. ~Span~, 32 feet (9.75 m.) ~Area~, 200 sq. feet (18-1/2 m².) ~Speed~, 100 m.p.h. (160 k.p.h.) ~Motor~, 100 Gnome. ~K~ KIRKHAM Biplanes. Chas. B. Kirkham, Motor Manufacturers, Savona, N.Y. Began to manufacture aeroplanes in 1912, after previous experiments and flights near his factory. ~Length~, ? feet ( ? m.) ~span~, 34 feet (10.40 m.) ~surface~, ? sq. feet ( ? m².) ~Weight.~--Complete, _without pilot_, 980 lbs. (445 kgs.) ~Motor.~--50 h.p. Kirkham, located in front under bonnet. 70 h.p. also fitted. ~Speed.~--56-62 m.p.h. (90-100 k.p.h.) Remarks.--Rises easily at under 35 m.p.h., and has a full speed radius of 5-1/2 hours. Full details in _Aeronautics_, U.S.A., January, 1912. 1913, no changes. [Illustration] ~L-S~ LOENING. Monoplane aero boat, with one very deep step. See _Aeronautics_, U.S.A., May-June, 1912. SELLERS. Quadruplane. Matthew B. Sellers, R.F., D2, Norwood, Ga. Has been successfully experimenting for a number of years with a staggered quadruplane, and has given the aviation world a number of valuable papers. His aim is to fly successfully with the least possible horse power. For several years he has been making flights with various engines delivering from 5 to 6 h.p. on careful test. The actual thrust has been measured and recorded in late 1911 experiments. Details in _Aeronautics_, June, 1909; October, 1909; November, 1910; January, 1911; January, 1912. No actual details of the machine are available, but it follows closely the patent drawings (see references). He is one of the few real scientific flying men in the U.S.A. The original machine with slight changes was still flying at end of 1912 with only 5 h.p. B.H.P. The flying speed is 20 m.p.h. [Illustration] SLOANE. Sloane Aeroplane Co., 1733, Broadway, New York. Established 1911. Agents for _Caudrons_ and _Deperdussins_. Run a school for these. ~T-V~ THOMAS Biplanes. Thomas Bros., Bath, N.Y., O.W., and W.T. Thomas began experimenting and flying in 1908 with a machine on the order of a _Curtiss_. In the winter of 1909-10, a type of their own was produced and was flown during 1911 by Walter Johnson in exhibitions. In 1912 they continued the same type, with refinements. In 1913 they adopted the overhanging top plane type, but of the same general high order of construction. ----------------------------+------------------+------------------+------------------+------------------+------------------ | ~1912.~ | | ~1913.~ | ~1913.~ | ~1913.~ Model and date. | Tractor | ~1913.~ | Standard | Special | Flying boat. | biplane. | Monoplane. | biplane. | biplane. | ----------------------------+------------------+------------------+------------------+------------------+------------------- ~Length~ ft.(m.)| ... | 30 (9.15) | ... | 25 (7.62) | ... ~Span~ ft.(m.)| 37 (11.27) | 32 (9.75) | 37 (11.27) | 33 (10) | 33 (10) | 27 (8.23) | ... | 27 (8.23) | 23 (7) | 23 (7) ~Area~ sq. ft.(m².)| ... | ... | ... | ... | ... {total lbs. (kgs.)| 900 (408) | 750 (340) | 900 (408) | 850 (385) | ... ~Weight~ { | | | | | {useful lbs. (kgs.)| ... | ... | ... | 400 (181) | ... ~Motor~ h.p.| 65 Kirkham | 70 Kirkham | 65 Kirkham | 65 Kirkham | 100 | | _muffled_ | | | Maximotor ~Speed~ m.p.h.(km)| 58 (94) | ... | 58 (94) | 60 (97) | ... ~Endurance~ hrs.| 2 | ... | 2 | 2-1/4 | ... Number built during 1912 | 1 | _building_ | ... | ... | _building_ ----------------------------+------------------+------------------+------------------+------------------+------------------- Remarks. Control in all: Ailerons, 4 rudders. Elevator operated by rocking post on which wheel is mounted. The 1912 tractor was given up as less efficient than the Standard 1913. Special: full description _Aeronautics_, U.S.A., May, 1913. The move was evolved 1912, but not built till well into 1913. [Illustration: 1913 Standard biplane. UAS.] ~W~ WASHINGTON. Washington Aeroplane Co., Washington, D.C. In 1913 built a flying boat to private order. ~Length~, 29 feet (8.83 m.) ~Maximum span~, 38 feet (11.85 m.) ~Motor~, 80 h.p. Gyro. Boat with eight compartments and one 3 inch step. [Illustration: Miss Columbia. UAS.] [Illustration: Latest Thomas.] WITTEMAN. Witteman Bros., 17, Ocean Terrace and Little Clare Road, Staton Island, N.Y. These people do a considerable business building Curtiss type machines or machines to special designs for others. They built the _Baldwin_ biplanes for Captain Baldwin, to his design, using steel tubing throughout. See _Aeronautics_, December, 1911, for a _Witteman_ of special design shown by them at the Aero Show. [Illustration: Witteman. 1912-13.] WRIGHT BROS. Biplanes. The Wright Co., Dayton, Ohio. The original type of _Wright_ machine was mounted on skids only, and started along a rail. Its special features were a biplane elevator forward, main planes with warpable tips to trailing edge, small keel in gap, 2 propellers, chain driven in rear of planes, double rudder in rear and no tail. Wilbur Wright flew a machine of this type for 2 h. 20 m. 23-1/2 s. in 1908. (Details of early _Wrights_ see previous editions of this book.) ----------------------------+------------------+------------------+------------------+------------------ Model and date. | ~B.~ | ~C.~ | ~EX.~ | ~E.~ ----------------------------+------------------+------------------+------------------+------------------ ~Length~ feet (m.)| 31 (9.45) | 29-3/4 (9) | ... | ... ~Span~ feet (m.)| 39 (11.90) | 38 (11.58) | 32 (9.75) | 32 (9.75) ~Area~ sq. feet (m².)| 500 (47) | 500 (47) | ... | ... {total lbs. (kgs.)| 1250 (567) | ... | ... | ... ~Weight~ { | | | | {useful lbs. (kgs.)| ... | ... | ... | ... ~Motor~ h.p.| 30-35 Wright | 30-35 Wright | 30 or 50 Wright | 30 or 50 Wright ~Speed~ m.p.h. (km.)| 45 (75) | 45 (75) | ... | ... ----------------------------+------------------+------------------+------------------+------------------ | | 1913 standard. | For exhibition | 1913 | | This machine as | work only. | for exhibition | | a hydro is fitted| Single seater | work only. | | with two 3 step | small duplicate | Single seater | | floats. | of B. | duplicate of EX | | Mea magneto. | |except fitted with | | | |a single propeller | | | | only. ----------------------------+------------------+------------------+------------------+------------------ [Illustration: Wright. Model B. UAS] [Illustration: Wright. Model C. _From "Aeronautics," U.S.A._ UAS.] U.S.A. DIRIGIBLES. There are a few small dirigibles in the U.S.A., but they are in no way to be compared to French and German productions. Up-to-date, they have only been used as attractions at fairs about the country. In the past several larger ones of poor design have been built and found failures. ~Military.~ BALDWIN (1908) 20,000 c. feet (560 m³) Part B. HISTORICAL AIRCRAFT. In the following pages an attempt has been made to include photographs of all aeroplanes of the past six years, which, for one reason or another, "made history" in their own day. While many are merely freak machines, which in the light of present knowledge seem ridiculous, the germ of modern practice is to be found in many other aircraft illustrated in this cemetery of dead ideals; and it is worth noting that at least one constructor, who is one of the first in the field to-day, commenced operations with machines which were entirely "freaks." ~AUSTRIAN.~ [Illustration: WELS & ETRICH (1908). Original form of the modern _Etrich_ (q.v.).] [Illustration: HIPSSICH (1908). Tandem mono. with one propeller before and another in rear of rear plane.] [Illustration: NEMETHY (1908). The first "Aviette."] [Illustration: SOLTAU (1910). An ornithopter based on the earlier ideas of _Adehmar de la Hault_ (see Belgium).] ~BELGIAN.~ [Illustration: DE LA HAULT (1907). One of the earliest attempts at an ornithopter. No flights.] [Illustration: DE LA HAULT II. (1910-11). The ornithopter principle applied to a monoplane. No success met with.] [Illustration: D'HESPEL (1909-10). Single plane and suspended body. Early example of enclosed body. No flights.] ~BRAZIL.~ [Illustration: SANTOS-DUMONT XIX. This little machine, surface only 9 m². made an extraordinary sensation in France in 1909. It flew at the then incredible speed of 65 m.p.h. (100 k.p.h.) Santos-Dumont presented all rights to the world soon afterwards, and a large number were built before it was realised that only an extremely light weight pilot could fly in one. Few of the copies ever left the ground.] ~BRITISH.~ [Illustration: AVRO (1906). This 24 h.p. biplane, designed by A. V. Roe, was the first British machine to leave the ground.] [Illustration: AVRO (1907). Tractor triplane of only 9 h.p. This flew in Lea Marshes--the lowest horse power yet flown in Europe to the present day.] [Illustration: CODY (1909). Development of a much earlier machine. This one was a general laughing stock for a long time; but it was the direct predecessor of the machine (not very materially different) which was an easy first in the British Army aeroplane trials, 1912.] [Illustration: DE HAVILLAND (1909). The performances of this machine secured a Government appointment for its aviator-designer.] [Illustration: HOWARD WRIGHT (1908-09). The first machine in the world in which special attention was paid to securing a stream line body and minimised wind resistance.] [Illustration: HUMPHREY (1908-09). Earliest British attempt at a hydro-aeroplane; possibly the earliest design ever produced anywhere.] [Illustration: HUNTINGDON (DUNNE II) (1910). One of the earliest aeroplanes in existence--designed by Captain Dunne about 1905-06, previous to the secret experiments of the British War Office in Scotland, on the Duke of Atholl's estate. Assigned to Prof. Huntingdon in 1910. Made a few short flights.] [Illustration: PORTE (1908). Designed by Lieut. Porte, R.N., in conjunction with Lieut. Pirrie, R.N. This machine, on which the former well known aviator commenced his flying career, was smashed up in preliminary trials as a glider on Portsdown Hill, Portsmouth. Its design apparently preceded the _Goupy_ in the use of staggered planes.] [Illustration: "SAFETY" (1909-10).] [Illustration: SEDDON. (1910). Designed by Lieut. Seddon, R.N.] [Illustration: SHORT (1910). The first machine to Short's own design. (The tail here shown is a specially large one fitted by Moore-Brabazon).] [Illustration: VALKYRIE (1910). This was one of the first "tail first" machines to be designed. The experimental machine (also known as the _A.S.L._), was completed in Feb., 1910.] ~DANISH.~ [Illustration: ELLEHAMMER (1905). On 12th September, 1906, this machine made the first free flight in Europe. On 28th June, 1908, it won the prize at Kiel for the first flight in Germany (distance, 47 m.) It was a tractor biplane with a revolving Ellehammer motor. It also had a pendulum seat as a stabilising device.] ~FRENCH.~ [Illustration: ANTOINETTE IV (1909). In this machine Latham made the first attempt to fly the Channel, 19th July, 1909.] [Illustration: BLERIOT IV (1907-8).] In 1909 the famous _Bleriot XI_ was built. This did very well at Reims, 1909. On 25th July, 1909, Bleriot made the first Cross-Channel flight in the machine illustrated below. [Illustration: Bleriot XI.] This machine had ~length~, 23 feet (7 m.) ~Span~, 25-3/4 feet (7.80 m.) ~Area~, 167 sq. feet (15-1/2 m².) Aspect ratio 4-1/2 to 1. ~Motor~, 22-25, 3 cylinder Anzani. ~Speed~, _about_ 45 m.p.h. (73 k.m.) _Special features_: Fixed wings with rounded edges. Twin elevator and fixed surface tail. [Illustration: BOUSSON-BORGNIS (1907-08).] [Illustration: BREGUET (1906). The first Breguet, known as _Breguet Gyroplane I_. Made a flight in October, 1906, being the first helicopter to leave the ground.] [Illustration: BREGUET-RICHET II bis. (1909). A large and unsuccessful development of the gyroplane.] [Illustration: BREGUET IV (1910). On its appearance, this machine was generally laughed at and nicknamed the "Coffee Pot," till in Aug., 1910, it made a world's record by carrying six, and later proved itself superior in stability to anything then existing.] [Illustration: CHAUVIÉRE (1909-10). Attempt to develop a monoplane with propellers in rear. The idea has been resuscitated for some 1913 military monoplanes.] [Illustration: COLLOMB (1907-09). Ornithopter, from which great things were once expected.] [Illustration: CORNU (1908). An early helicopter for which flights were claimed, but have also been denied.] [Illustration: D'EQUIVELLY (1907-08). Interesting example of the strange machines devised by pioneers.] [Illustration: H. FARMAN (1907). This famous machine is the first _Voisin_, and the one on which H. Farman taught himself to fly. It was the first machine to make a turn in the air. Won the Deutsh-Archdeacon Grand Prix, 13th January, 1908, with a flight of 1 minute, 28 seconds. The extra third plane was added later. An Austrian Syndicate subsequently bought the machine.] [Illustration: H. FARMAN (1908). Farman's first idea of a monoplane. It proved too heavy to fly with the power provided. Was eventually sold to a German officer. Three sets of wings and entirely enclosed body.] [Illustration: GABARDINI (1909-10). Very early hydro-aeroplane, antedating the _Fabre_.] [Illustration: GIVAUDIN (1908-09). Built by the Vermorel Co. The first conception of an idea which has since attracted a certain class of inventor in Germany, Italy and the U.S.A.] [Illustration: MILITARY (1909). The first special military aeroplane ever built. It was specially designed by Capt. Dorand, for what were then held to be the aerial necessities of the French Army. The planes were placed well above the body, giving the pilot a very clear uninterrupted view.] [Illustration: PISCHOFF-KOECHLIN (1906 or earlier). Dates from the days when a box-kite was the elementary idea in design, and the accepted position of the aviator lying prone.] [Illustration: PISCHOFF-KOECHLIN (1908). Very early example of a tractor biplane. The extra span of the upper plane is also of interest. The machine had twin mono-elevators aft and also twin rudders.] [Illustration: R.E.P. (1908). Early example of enclosed stream line body. Apparently the first machine in which steel construction appeared.] [Illustration: VOISIN (1908). The first European aeroplanes to fly with any real success.] [Illustration: VUITTON-HUBER (1908). Early helicopter.] [Illustration: VUIA (1908). Earliest known machine with folding wings.] [Illustration: WITZIG-LIORE-DUTILLUEL (1908-09). First or one of the first appearances of the idea of a series of staggered planes, with which Sellers has ever since experimented in the U.S.A.] ~GERMAN.~ [Illustration: BEILHARZ. (1909). First design in which a completely closed in body figured.] [Illustration: GEISLER (1908).] [Illustration: GRADE (1908). The first German built machine to fly.] [Illustration: LORENZEN (1908-09).] [Illustration: PARSEVAL (1909). Early hydro-aeroplane. Specially designed for military purposes by Major Parseval.] [Illustration: SCHOLTZ (1908). Never left the ground.] ~ITALIAN.~ [Illustration: MILLER (1908-09). First aeroplane to be designed and constructed by Italians.] ~SWISS.~ [Illustration: DUFAUX (1908-09). First Swiss machine.] ~U.S.A.~ [Illustration: BOKOR (1909). The third American machine to leave the ground; the second purely U.S. one.] [Illustration: CALL II (1909).] [Illustration: CYGNET II (1908). Designed by Dr. Graham Bell, of the Aeronautical Society of America. Bell (Canadian), Glen Curtis (U.S.), Herring (U.S.), and Burgess (Canadian). It made short flights.] [Illustration: ENGLISH (1909). In 1909 extraordinary claims were made for this machine and great things expected. On a full power trial in its shed it broke loose, and smashed itself against the roof. No recorded outdoor results.] [Illustration: HERRING-BURGESS (1910).] [Illustration: HULBERT (1910). This strange machine built in Switzerland by Dr. Dane Hulbert, achieved several flights. The planes were placed longitudinally instead of in the usual way.] [Illustration: JUNE BUG (1908-09). Famous machine of its era. Built by the Aeronautical Society of America (see _Cygnet II_). Second machine to fly in the U.S.A. Did 2000 miles before being broken up.] [Illustration: KIMBALL (1909). First machine in which a large number of propellers was attempted. Failed.] [Illustration: LOOSE (1910).] [Illustration: LUYTIES OTTO (1908).] [Illustration: MOISSANT (1910). Built entirely of aluminium. Designed by the late John Moissant. Failed.] [Illustration: RICKMAN (1908).] [Illustration: ROSHON (1908).] [Illustration: WILLIAMS (1908).] [Illustration: ZERBE (1909).] [Illustration] [Illustration: WRIGHT (1908). Two views of the machine with which Wilbur Wright startled all Europe from August, 1908 to April, 1909. First U.S. machine to fly.] Part C. AERO ENGINES, ALPHABETICALLY ARRANGED IN ORDER OF COUNTRY OF ORIGIN. ~AUSTRIAN, BELGIAN, BRITISH, FRENCH, GERMAN, ITALIAN, U.S.A.~ ~Note.~--So far as possible this is a complete list of all the aero engines of any importance. Data are confined to what is now being made or actually in use; untested "show novelties" are ignored. In the case of some engines it has for various reasons proved impossible to obtain full data in time for inclusion in this edition. In a general way these lists are confined to aeroplane engines. ~AUSTRIAN.~ ~Revised by Herr Ing. W. Isendahl.~ ----------------------------------------------------+----------------------------------------------------+ ~AUSTRO-DAIMLER.~ | ~KÖRTING.~ | ----------------------------------------------------+----------------------------------------------------+ 35-40 h.p., 4 cyl., 100×120 (1450 r.p.m.) 165 lbs. | [Illustration] | 65-70 h.p., 4 cyl., 120×140 (1350 r.p.m.) 232 lbs. | | 120 h.p., 6 cyl., 130×175 (1200 r.p.m.) 419 lbs. | Note.--This engine is no longer made, but it is to | | be found still in some dirigibles. | Vertical water-cooled. | | | | H.T. Magneto. | | All Valves overhead. Rocking levers and piston | | rods. | | Forced lubrication. | | | | Pressed steel pistons. | | Nickel-chrome crank shaft, hollow and closed. | + White-metal bearings. | | Cast-iron single cylinders (copper jackets). | | Single camshaft. | | | | [Illustration: 120 h.p.] | | | | The 120 has 2 carburetters and 2 H.T. magnetos. | | ----------------------------------------------------+----------------------------------------------------+ ~BELGIAN.~ +-------------------------------------------------+---------------------------------------------------- | ~METALLURGIQUE.~ | ~PIPE.~ +-------------------------------------------------+---------------------------------------------------- | 40 h.p., 4 cyl., 85×130 (1850 r.p.m.) | 50-70 h.p., 8 cyl., 100×100 (1950 r.p.m.) 239 lbs. | 60 h.p., 4 cyl., 100×150 (1850 r.p.m.) 300 lbs. | 110 h.p., 8 cyl. | 90 h.p., 4 cyl., 125×150 (1600 r.p.m.) 550 lbs. | | | Vertical, air-cooled (fan). | Vertical, water-cooled. | | | H.T. magneto. | H.T. magneto. | Mechanical inlets. | Mechanical inlets. | Pump lubrication. | Pump lubrication. | | | | | | | +-------------------------------------------------+---------------------------------------------------- | <b>MIESSE.</b> | <b>VIVINUS.</b> | | |50-60 h.p., 4 cyl. lbs. | 50 h.p., 4 cyl., 106×120 (1600 r.p.m.) 205 lbs. |100 h.p., 8 cyl., 130×140 245 lbs. | 60 h.p., 4 cyl., 112×130 (1600 r.p.m.) 236 lbs | | 70 h.p., 4 cyl., 115×130 (1800 r.p.m.) 280 lbs. |Horizontal opposed, air-cooled (fan). | | | Vertical, water-cooled. |H.T. magneto | |Mechanical inlets. | H.T. magneto. |Pump lubrication. | Mechanical inlets. | | Pump lubrication. |<i>Features.</i>-- | | | |Air cooling is carried out by fans which drive | |air through air jackets on cylinders. | |All valves in cylinder heads, rocker operated. | |Vertical crank shaft. | +-------------------------------------------------+---------------------------------------------------- ~BRITISH.~ --------------------------------------------------+----------------------------------------------------+-----------------------------------------------------------+---------------------------------------------------- ~A.B.C.~ | ~GREEN.~ | ~N.E.C.~ | ~WOLSELEY.~ All British Engine Co., Ltd., Brooklands, Surrey.| Green Engine Co., Ltd., 455, Berners Street, | New Engine (Motor) Co. Ltd., 9, Grafton Street, | Wolseley Tool & Motor Car Co., Ltd., | London, W. | Bond Street, London, W. | Adderley Park, Birmingham. --------------------------------------------------+----------------------------------------------------+-----------------------------------------------------------+---------------------------------------------------- 30 h.p., 4 cyl., 95×80 (1450 r.p.m.) 155 lbs. | 30-35 h.p., 4 cyl., 105×120 158 lbs. | 50 h.p., 4 cyl., 95×115 (1250 r.p.m.) 205 lbs. | 60-80 h.p., 8 cyl., 95×140, type A 325 lbs. 45 h.p., 6 cyl., 95×80 (1450 r.p.m.) 225 lbs. | 50-60 h.p., 4 cyl., 140×146 263 lbs. | 90 h.p., 6 cyl., 96×115 (1250 r.p.m.) 405 lbs. | " " " " B 345 lbs. 60 h.p., 8 cyl., 95×80 (1450 r.p.m.) 231 lbs. | 90-100 h.p., 6 cyl., 140×152 298 lbs. | | " " " " C 315 lbs. 85 h.p., 6 cyl., 125×105 (1700 r.p.m.) 290 lbs. | Vertical, water-cooled (pump). H.T. magneto. | Two stroke vertical for the 90 h.p. ~V~ for the 50. | " " " " D 335 lbs. 115 h.p., 8 cyl., 125×105 (1400 r.p.m.) 380 lbs. | Mechanical inlets. Forced lubrication.| | 120 h.p., 8 cyl., 125×175 (1150 r.p.m.) 630 lbs. 170 h.p., 12 cyl., 125×105 (1400 r.p.m.) 520 lbs. | | H.T. magneto. | ~V~ type. Types A and B of the 60-80 air-cooled 225 h.p., 16 cyl., 125×105 (1400 r.p.m.) 640 lbs. | _Features._-- | Valveless. | (water-cooled exhausts). The others water-cooled. | Cast-iron cylinders. Overhead cam shaft. | Forced lubrication. | Types A and C of the 60-80 are for direct coupling ~V~ type, water-cooled (pump). | Copper jackets. Nickel chrome crank shaft.| | of propeller, with double thrust ball bearings. | Overhead valves. White metal bearings. | _Features._-- | Types B and D geared to half crank shaft speed. H.T. magneto. | | | Bosch dual ignition. Mechanical inlets. | [Illustration] | Pistons after uncovering exhaust ports open | Mechanical inlets. Forced lubrication. | | the inlet ports. Air from blowers | Forced lubrication. | | scavenges. Strong mixture enters | _Features._-- _Features._-- | | immediately on compression stroke. | Steel cylinders (single). | | This is effected by a central mechanism. | Overhead valves (removable seats). Steel cylinders (steel and copper jackets). | | | Carburettor between cylinders. Overhead vertical valves. | | (N.B. Older types see previous editions.) | Nickel chrome crank shaft, on 3 bearings. Cast-steel crank case. | | | Nickel chrome crank shaft, white metal | | [Illustration] | [Illustration] bearings. | | | --------------------------------------------------+----------------------------------------------------+-----------------------------------------------------------+---------------------------------------------------- ~FRENCH.~ ---------------------------------------------------------------+--------------------------------------------------+----------------------------------------------------+-------------------------------------------------- ~ANZANI.~ | ~BERTIN.~ | ~CANTON-UNNÈ (SALMSON).~ | ~CLEMENT BAYARD.~ 71, _bis_ Quai d'Asinières (Seine). | 8, rue Garancier, Paris. | E. Salmson, 55, rue Grange aux Belles, Paris. | Usineo Clement Bayard, 33 quai Michelet, | | | Levallois-Perret, (Seine). ---------------------------------------------------------------+--------------------------------------------------+----------------------------------------------------+-------------------------------------------------- 30 h.p., 3 cyl., 105×130 (1575 r.p.m.) 154 lbs. | 50 h.p., 4 cyl., 116×150 (1100 r.p.m,) 132 lbs. | 60 h.p., 7 cyl., 75×260 (1300 r.p.m.) 220 lbs. | 40 h.p., 4 cyl., 100×120 242 lbs. 30 h.p., 3 cyl., 105×120 (1300 r.p.m.) 121 lbs. | 100 h.p., 8 cyl., 116×150 (1100 r.p.m.) 209 lbs. | 80 h.p., 7 cyl., 120×140 (1250 r.p.m.) 298 lbs. | 100 h.p., 4 cyl., 135×160 (1500 rp.m.) 463 lbs. 40-45 h.p., 6 cyl., 90×120 (1300 r.p.m.) 154 lbs. | | 110 h.p., 9 cyl., 120×140 (1300 r.p.m.) 353 lbs. | 130 h.p., 4 cyl., 155×185 50-60 h.p., 6 cyl., 105×120 (1300 r.p.m.) 200 lbs. | ~X~ type air cooled. | | 180 h.p., 6 cyl., 155×185 (1200 r.p.m.) 80 h.p., 10 cyl., 90×130 (1250 r.p.m.) 238 lbs. | | The 60 h.p. has parallel a.c. cylinders, the other | 200 h.p., 4 cyl., 190×230 (1200 r.p.m.) 1100 lbs. 100 h.p., 10 cyl., 105×140 (1100 r.p.m.) 308 lbs. | | two are radial w.c. | | | | H.T. magneto. Radial type, air-cooled (but water-cooling is occasionally | | There is also a horizontal radial engine (w.c.) | G.A. carburetter. Forced lubrication. fitted). | | 300 h.p., 9 cyl., 150×210 (1200 r.p.m.) 990 lbs. | | | | Overhead valves worked by two cams only. H.T. magneto. | | H.T. magneto. | Exhausts opened and closed by spring on tappet. Mechanical inlets. | | Mechanical inlets. | Forced lubrication. | | Forced lubrication. | _40 h.p._, vertical, _en bloc_, water-cooled, copper, | | Steel cylinders, copper jackets. | jacket, all valves same side, single cam shaft, _Features._-- | | Overhead Valves. | splash lubrication. Special carburetter, jet in | | Single special steel crank shaft on ball bearings. | centre of float chamber. Extremely simple construction. | | Aluminium alloy or steel crank case. | Mainshaft single crank. | | | _130 and 180 h.p._ (for dirigibles), cylinders in pairs, Flywheel specially balanced to compensate. | | [Illustration] | water-cooled. Overhead valves, single over-head Zenith carburetter. +--------------------------------------------------+ | cam shaft. Two ignitions. Expanding | ~BURLAT.~ | | clutch. | 289 Avenue de Saxe, Lyon (Rhone). | | | | | [Illustration: Dirigible engine.] | 35 h.p., 8 cyl., 95×120 (956 r.p.m.) 187 lbs. | | | 60 h.p., 8 cyl., 120×120 (940 r.p.m.) 264 lbs. | | | 75 h.p., 8 cyl., 120×170 (940 r.p.m.) 308 lbs. | | | 120 h.p., 16 cyl., 120×120 (900 r.p.m.) 495 lbs. | | | | | | Rotary, air-cooled. | | ------------------------------------------------------+------------------------------------------------------+------------------------------------------------------+------------------------------------------------------ ~CHENU.~ | ~CLERGET.~ | ~DANSETTE GILLET (LAVIATOR).~ | ~DE DION.~ Chenu, 10 Rue Fontaine-Saint-Georges, Paris. | Clerget & Cie, 11 rue Leon-Cogniet, Paris. | Dansette Gillet & Cie., 36 quai de. | Établissements de Dion-Bouton, 52 avenue des | | Suresnes, Suresnes (Seine). | Champs-Élysées, Paris. ------------------------------------------------------+------------------------------------------------------+------------------------------------------------------+------------------------------------------------------ 50 h.p., 4 cyl., 110×130 (1300 r.p.m.) 253-1/2 lbs. | 43 h.p., 4 cyl., 100×120 (1600 r.p.m.) | 80 h.p., 8 cyl., 100×130 (1200 r.p.m,) 418 lbs. | 80 h.p., 8 cyl., 100×120 (1700 r.p.m.) 484 lbs. 75 h.p., 6 cyl., 110×130 (1300 r.p.m.) 375 lbs. | 50 h.p., 4 cyl., 110×120 (1500 r.p.m.) 172 lbs. | 110 h.p., 6 cyl., 130×160 (1100 r.p.m.) 616 lbs. | 150 h.p., 8 cyl., 125×150 (1600 r.p.m.) 968 lbs. 200 h.p., 6 cyl., 150×200 860 lbs. | 100 h.p., 4 cyl., 140×160 (1250 r.p.m.) 342 lbs. | 120 h.p., 4 cyl., 145×175 (1200 r.p.m.) 484 lbs. | ~V~ type, air-cooled for the 80; water-cooled for the | 50-60 h.p., 7 cyl., 120×120 (1200 r.p.m.) 198 lbs. | 120 h.p., 8 cyl., 114×160 (1200 r.p.m.) 418 lbs. | 150. Vertical, water-cooled (thermo syphon). | 200 h.p., 8 cyl., 140×160 (1275 r.p.m.) 495 lbs. | 200 h.p., 8 cyl., 147×175 (1100 r.p.m.) 715 lbs. | | | 250 h.p., 6 cyl., 180×200 (1050 r.p.m.) 1210 lbs. | H.T. magneto. H.T. magneto. | The 43 h.p. 50 and 100 vertical engines, w.c. | | Pump lubrication. Automatic lubrication. | | The 110, 120 (4 cyl.) and 250 are vertical, the | Forced lubrication. | The 50-60 h.p. is a radial, rotary. | others are ~V~ type. | Cylinders in pairs. | | | [Illustration: De Dion.] | The 200 h.p. has 2 carburetters and 2 magnetos, | | | and is ~V~ type. | | | | | | [Illustration: 200 h.p. Clerget.] | | | | | ------------------------------------------------------+------------------------------------------------------+------------------------------------------------------+------------------------------------------------------ ~DUTHEIL CHALMERS (EOLE).~ | ~GNOME~ | ~LABOR AVIATION.~ | ~PANHARD.~ Dutheil Chalmers & Cie., 81-83 avenue d'italie, Paris.| Société des moleurs Gnome, 3 rue La Boëtie, Paris. | Soc. anonyme des moteurs Labor Aviation, 29 rue de | Société Panhard & Levassor, avenue d'Ivry, Paris. | | la Révolte, Levallois Perret (Seine). | ------------------------------------------------------+------------------------------------------------------+------------------------------------------------------+------------------------------------------------------ 40 h.p., 4 cyl., 125×120 250 lbs. | 50 h.p., 7 cyl., 11$1×$220 (1200 r.p.m.) 165 lbs. | 42 h p., 4 cyl., 90×150 (1200 r.p.m.) 221 lbs. | 35-40 h.p., 4 cyl., 110×140 210 lbs. 60 h.p., 6 cyl., 125×120 350 lbs. | 70 h.p., 7 cyl., 13$1×$220 (1300 r.p.m.) 183 lbs. | 72 h.p., 4 cyl., 100×210 (1200 r.p.m.) 353 lbs. | 55 h.p., 6 cyl., 110×140 341 lbs. | 80 h.p., 7 cyl., 124×140 (1200 r.p.m.) 191 lbs. | 120 h.p., 4 cyl., 120×250 419 lbs. | 100 h.p., 8 cyl., 110×140 (1500 r.p.m.) 440 lbs. Opposed horizontal, water-cooled. | 100 h.p., 14 cyl., 110×120 (1200 r.p.m.) 220 lbs. | | | 140 h.p., 14 cyl., 130×120 (1200 r.p.m.) 286 lbs. | Vertical water-cooled (pump). | Vertical, water-cooled. H.T. magneto. | 160 h.p., 14 cyl., 124×140 (1200 r.p.m.) 308 lbs. | | Automatic inlets. | | H.T. magneto. | H.T. magneto. Pump lubrication. | Radial rotary, air-cooled. | Mechanical inlets. | Mechanical inlets. | | Forced lubrication. | Pump lubrication. also | H.T. magneto. | | | Automatic inlets. | _Features:_-- | _Features._-- ~EOLE.~ (Dutheil Chalmers.) | Forced lubrication. | | | | Automatic carburetter. | Cast-iron cylinders, jackets in casting. 40 h.p., 4 cyl., 130×130 198 lbs. | _Features._-- | | Valves at side. | | [Illustration] | Cam shaft in crank case. Horizontal w.c., with central crank shaft over | Single crank pin +------------------------------------------------------+ Nickel chrome crank shaft; white metal head valves. | Steel cylinders turned from solid. | ~LA RHONE~ | bearings. | Single ignition point. | | 100 h.p., 8 cyl. | Gas admitted through hollow crank shaft to | 50 h.p., 7 cyl., 105×140 176 lbs. | [Illustration] | crank case, thence to pistons; oil enters | 80 h.p., 9 cyl., 105×140 242 lbs. | Crank shaft at either end, all valves in centre. | in a similar way. | 100 h.p., 14 cyl., 105×140 308 lbs. | There is also a 120 h.p. 4 cylinder for dirigibles. | Nickel chrome crank shaft, ball bearings. | 160 h.p., 18 cyl., 105×140 374 lbs. | [Illustration] | Steel crank case. | (1200 r.p.m. in all.) | | The 100 h.p. has seven cylinders behind seven | | | others. Larger sizes ditto. | Rotary, air-cooled. | | Older engines of 50-100 h.p. do not differ in | | | general details. | | | | | | [Illustration: 50 h.p. Gnome.] | | | | | ------------------------------------------------------+------------------------------------------------------+------------------------------------------------------+------------------------------------------------------ ~RENAULT~ | ~R.E.P.~ | ~ROSSEL-PEUGEOT.~ | ~VIALE.~ Automobiles Louis Renault, 15 rue Gustav-Sandoz, | Établissement Robert Ésnault Pelterie, 149 rue de |Soc. anonyme de constructions aerienne Rossel-Peugeot,| Viale & Cie. 19 rue de la Mairie, Boulogne-sur-Seine Billancourt (Seine). | Silly, Billancourt (Seine). | rue de Longchamp, à Suresnes (Seine). | (Seine). ------------------------------------------------------+------------------------------------------------------+------------------------------------------------------+------------------------------------------------------ 25 h.p., 4 cyl., 90×120 243 lbs. | 45 h.p., 5 cyl., 100×140 243 lbs. | 30-40 h.p., 7 cyl., 105×110 (1100 r.p.m.) 165 lbs. | 30 h.p., 3 cyl., 105×130 (1250 r.p.m.) 165 lbs. 35 h.p., 8 cyl., 75×120 243 lbs. | 60 h.p., 5 cyl., 110×160 (1100 r.p.m.) 330 lbs. | 40-50 h.p., 7 cyl., 110×110 (1100 r.p.m.) 172 lbs. | 50 h.p., 5 cyl., 105×130 (1250 r.p.m.) 199 lbs. 50 h.p., 8 cyl., 90×120 375 lbs. | 90 h.p., 7 cyl., 110×160 (1100 r.p.m.) 463 lbs. | 50-55 h.p., 7 cyl., 110×110 (1150 r.p.m.) 165 lbs. | 70 h.p., 7 cyl., 105×130 (1250 r.p.m.) 254 lbs. 70 h.p., 8 cyl., 96×140 397 lbs. | | | 100 h.p., 10 cyl., 105×130 (1250 r.p.m.) 320 lbs. 90 h.p., 12 cyl., 96×140 640 lbs. | Radial, air-cooled. | Rotary, air-cooled. | (All at 1800 r.p.m.) | | | Radial, air-cooled. | H.T. magneto and accumulators. | H.T. magneto. | Cylinders at 90°. | Mechanical inlets. | Mechanical inlets. | [Illustration: VIALE.] ~V~ type, air-cooled. | Forced lubrication. | Forced lubrication. | | | +------------------------------------------------------ H.T. magneto. | _Features._-- | [Illustration: ROSSEL-PEUGEOT.] | Mechanical inlets. | | | ~VERDET.~ Pump lubrication. | In the 7 cyl. the cylinders are in two planes, | There is also a vertical water-cooled motor (1913). | | four being in front of the others. | 100 h.p., 140×140 (1300 r.p.m.) 352 lbs. | 55 h.p., 7 cyl., 112×140 (1100 r.p.m.) 176 lbs. _Features._-- | | | | The 5 cyl. engines are fan shape in one plane. | | Rotary, air-cooled. Two to one shaft, made specially strong to | | | admit of the direct coupling of a propeller. | [Illustration: 7 cylinder.] | | | | | Inlet valves operated from below, exhausts | | | placed above them at the side. | | | | | | Plain bearings. | | | | | | Special cooling. | | | | | | [Illustration] | | | | | | ------------------------------------------------------+------------------------------------------------------+------------------------------------------------------+------------------------------------------------------ ~GERMAN.~ ~Revised by Herr Ing. W. Isendahl.~ ------------------------------------------------------+----------------------------------------------------+----------------------------------------------------+---------------------------------------------------- ~ARGUS.~ | ~BENZ.~ | | Argus-Motoren G.m.b.H., Flottenstrasse 39 and 40, | Benz & Cie, Mannheim. | ~DELFOSSE (radial.)~ | ~DELFOSSE (rotary.)~ Reinickendorf bei Berlin. Established 1900. | | | ------------------------------------------------------+----------------------------------------------------+----------------------------------------------------+---------------------------------------------------- 70 h.p., 4 cyl., 124×130 (1400 r.p.m.) 254 lbs. | 100 h.p., 4 cyl., 130×180 (1250 r.p.m.) 337 lbs. | 24-30 h.p., 3 cyl., 110×130 (1500 r.p.m.) 100 lbs. | 30 h.p., 3 cyl. (1500 r.p.m.) 121 lbs. 100 h.p., 4 cyl., 140×140 (1250 r.p.m.) 290 lbs. | Vertical, water-cooled (pump). | 30-40 h.p., 3 cyl., 120×140 (1400 r.p.m.) 120 lbs. | 50 h.p., 5 cyl., 110×130 (1400 r.p.m.) 176 lbs. 150 h.p., 6 cyl., 140×140 (1250 r.p.m.) 353 lbs. | 2 H.T. magneto (Bosch). | 35-45 h.p., 4 cyl., 110×130 (1500 r.p.m.) | 70 h.p., 7 cyl., 110×138 (1200 r.p.m.) | Mechanical inlets. | 50-70 h.p., 4 cyl., 120×140 (1500 r.p.m.) | Vertical, water-cooled (pump). | Forced lubrication. | 50-60 h.p., 6 cyl., 110×130 (1500 r.p.m.) | Rotary air-cooled. | _Features._-- |80-100 h.p., 6 cyl., 120×140 (1500 r.p.m.) | H.T. magneto (Bosch). H.T. magneto (Bosch). | | | Overhead valves. Mechanical inlets. | Cast-iron cylinder, steel jackets. | Radial air-cooled. | Automatic inlets. _Features._-- | Single cylinders. | H.T. magneto (or 6 volt accumulator). | Steel cylinders. | All valves overhead (single cam shaft). | Automatic inlets. | Crank shaft on ball bearings. Cast-iron cylinders. | Crank shaft hollow oil 5 metal bearings. | Forced lubrication. | Cylinders in pairs. | | | [Illustration: DELFOSSE] Valves one side (single cam shaft). | [Illustration] | _Features._-- | Crank shaft on ball bearings, closed and hollow. | | | | This engine won the Kaiser's prize of 50,000 marks.| Special metal cylinders. | [Illustration: 100 h.p.] | | Very large valve chambers. | | | Chrome nickel crankshaft and big ends. | | | Water-cooling fitted if required at a 10% increase | | | of weight. | | | | | | [Illustration: DELFOSSE RADIAL.] | ------------------------------------------------------+----------------------------------------------------+----------------------------------------------------+---------------------------------------------------- ~DIXI.~ | ~HILZ.~ | ~MERCEDES-DAIMLER.~ | Dixi Luftfahrt-u-Bootsmotoren-Verkaufsgesellschaft | Hilz Motorenfabrik G.m.b.H., Fürstenwallstr. 189, | Daimler Motoren G.m.b.H., Stuttgart-Unterturkheim. | m.b.H., Bulowstr. 11, Berlin W. 25. Established 1911.| Düsseldorf. | | ------------------------------------------------------+----------------------------------------------------+----------------------------------------------------+---------------------------------------------------- 50 h.p., 4 cyl., 100×140 (1400 r.p.m.) 198 lbs. | 25-30 h.p., 3 cyl., 105×130 (1400 r.p.m.) ? | 70 h.p., 4 cyl., 120×140 (1400 r.p.m.) 276 lbs. | 75 h.p., 4 cyl., 120×170 (1300 r.p.m.) 308 lbs. | 50 h.p., 5 cyl., 105×130 (1400 r.p.m.) ? | 70 h.p. (as above, but _inverted_) 298 lbs. | [Illustration: 70 h.p. Mercedes-Daimler.] 100 h.p., 4 cyl., 140×200 (1200 r.p.m.) 452 lbs. | | 90 h.p., 6 cyl., 105×140 (1350 r.p.m.) 309 lbs. | | Radial, air-cooled. | | Vertical, water-cooled (pump). | H.T. magneto (Bosch). | Vertical, water-cooled (pump). | | Automatic inlets. | H.T. magneto (Eismann in the 70, two Bosch in | H.T. magneto (Bosch). | Splash and forced lubrication. | the 90). | Mechanical inlets. | Steel cylinders. | Mechanical inlets. | Forced lubrication. | Crank shaft, hollow, on white metal bearings. | Forced lubrication. | | | | _Features._-- | [Illustration] | _Features_ of the 70's-- | | | | Cast-iron cylinders, copper jackets. | | Cast-iron cylinders (in pairs). | Single cylinders. | | Overhead valves. | Overhead inlets (single cam shaft). | | Single cam shaft. | Crank shaft, hollow, on 3 metal bearings. | | Crank shaft, hollow, on metal bearings. | | | | [Illustration: 100 h.p.] | | _Features_ of the 90.-- | | | | | | Steel cylinders, with steel jackets. | | | 2 carburetters (Mercedes-Daimler), _otherwise | | | as the 70's_. | | | | | | [Illustration: 90 h.p.] | ------------------------------------------------------+----------------------------------------------------+----------------------------------------------------+---------------------------------------------------- ~N.A.G.~ | ~OTTO ("A.G.O.")~ | ~ROTOR.~ | ~SYLPHE.~ Neue Automobile Ges. m.b.H., Berlin-Oberschoneweide. | Gustav Otto, G.m.b.H., Karlstrasse 72, Munich. | | ------------------------------------------------------+----------------------------------------------------+----------------------------------------------------+---------------------------------------------------- 60 h.p., 4 cyl., 118×100 (1400 r.p.m.) 254 lbs. | 50 h.p., 4 cyl., 110×150 (1400 r.p.m.) 199 lbs. | 70 h.p., 7 cyl., 110×150 (1100 r.p.m.) 199 lbs. | 40 h.p., 5 cyl., 110×130 (1200 r.p.m.) ? lbs. 95 h.p., 4 cyl., 135×165 (1350 r.p.m.) 353 lbs. | 70 h.p., 6 cyl., 110×150 (1400 r.p.m.) 287 lbs. | 90 h.p., 9 cyl., 110×150 (1100 r.p.m.) 243 lbs. | | 100 h.p., 4 cyl., 140×150 (1300 r.p.m.) 353 lbs. | | Rotary, air-cooled. Vertical, water-cooled (pump). | | Rotary, air-cooled. | | Vertical, water-cooled (pump). | | H.T. magneto (Eismann). H.T. magneto (Bosch), 2 in the 95 h.p. | | H.T. magneto. | Automatic inlets. Mechanical inlets. | H.T. magneto (Bosch). | Automatic inlets. | Forced lubrication (fresh oil). Forced lubrication. | Mechanical inlets. | Forced lubrication (fresh oil). | | Forced lubrication. | | _Features._-- _Features._-- | | _Features._-- | | _Features._-- | | Chrome nickel steel cylinders. Cast-iron cylinders, copper jackets. | | Steel cylinders. | Single cylinders. Cylinders in pairs. | Cast-iron cylinders. | Single cylinders. | Overhead valves. Single cam shaft. | Single cylinders, all connected by long bolts | Overhead valves. | Crank shaft, hollow, on metal bearings. Overhead valves. | and nuts. | Crank shaft, hollow, on ball bearings. | Crank shaft, hollow, on 5 metal bearings. | Overhead valves in the 100 h.p. Side valves | | [Illustration: 30-40 h.p.] | in the 50 and 70. | | [Illustration: 95 h.p.] | Single cam shaft. | | | Crank shaft hollow, on metal bearings. | | | | | | [Illustration] | | ------------------------------------------------------+----------------------------------------------------+----------------------------------------------------+---------------------------------------------------- ~ITALIAN.~ ----------------------------------------------------+----------------------------------------------------+----------------------------------------------------+----------------------------------------------------- ~CAPRONI & FACCANONI.~ | (_Dirigibles only._) ~FIAT.~ | (_Dirigibles only._) ~ISOTTA-FRASCHINI.~ | ~ITALA.~ Soc. di Aviazione Ing^{ri} Caproni & Faccanoni, | Fabbrica Italiano Automobile Torino, 30-35 | Fabbrica Automobili Isotta-Fraschini, 79 Via | Itala Fabbrica Automobili, Barriera Orbassano, Vizzola Ticino. | Corso Dante, Turin (Torino). | Monte Rosa, Milan. | Turin (Torino). ----------------------------------------------------+----------------------------------------------------+----------------------------------------------------+----------------------------------------------------- 60 h.p., 6 cyl., 105×130 176 lbs | 60 h.p., 4 cyl., 150×200 (1200 r.p.m.) 220 lbs. | 100 h.p., 4 cyl., 130×180 ( r.p.m.) 662 lbs. | 50-55 h.p., 4 cyl., 115×140 (1500 r.p.m.) 397 lbs. 120 h.p., 12 cyl., 105×130 lbs. | 200 h.p., 4 cyl., 170×250 (1200 r.p.m.) 1443 lbs. | 500 h.p., 8 cyl., 150×200 ( r.p.m.) 1543 lbs. | | | | Vertical, water-cooled (pump). Radial, air-cooled. | Vertical. | Vertical. | | | | H.T. magneto. H.T. magneto. | H.T. magneto and accumulators. | H.T. magneto. | Mechanical inlets. Mechanical inlets. | Mechanical inlets. | Mechanical inlets. | Forced lubrication. Forced lubrication. | Forced lubrication. | Forced lubrication (pump). | | | | _Features._-- | _Features._-- | _Features._-- | | | | Cylinders in pairs. | Enclosed valves. | Overhead inlets. | Overhead inlets. | Single cast-iron cylinders. | Horizontal exhausts. | Automatic carburetter. | | Special radiation. | +----------------------------------------------------+ Zenith carburetter. | [Illustration] | ~GNOME.~ | | | Fab. Italiana Mot. Gnome, 73 Strada Venaria, | | | Turin (Torino). | | +----------------------------------------------------+ | | Works of the Italian built Gnome engines. | | | | | ----------------------------------------------------+----------------------------------------------------+ ~L. U. C. T.~ | ~S. P. A.~ | Ladetto-Ubertalli & Cavalchini, Via Cavalli.-Angolo| Società Ligure Piemontese Automobili, Barriera | Via Circonvallazione Turin (Torino). | Crocetta, Turin. | ----------------------------------------------------+----------------------------------------------------+ 50 h.p., 7 cyl., 110×120 lbs. | 40-50 h.p., 4 cyl., 95×150 (1200 r.p.m.) 199 lbs. | 80 h.p., 9 cyl., 110×120 lbs. | | 100 h.p., 9 cyl., 122×150 lbs. | Horizontal, water-cooled (pump). | | | Rotary, air-cooled. | H.T. magneto and accumulators. | | Mechanical inlets. | H.T. magneto. | Forced lubrication. | Mechanical inlets. | | Forced lubrication. | _Features._-- | | | | Two pistons per cylinder. | | Ball bearings throughout. | | | | [Illustration: _Dirigible engine._] | | There is also a vertical 160 h.p. dirigible engine.| | | | | | | | | | | ----------------------------------------------------+----------------------------------------------------+ ~SWISS.~ +---------------------------------------------------- | <b>OERLIKON.</b> |Société Oerlikon Suisse de Machines Outils, Oerlikon. | +---------------------------------------------------- | 55 h.p., 4 cyl., 100×200 (1200 r.p.m.) 176 lbs. | | Horizontal opposed, water-cooled (pump). | | H.T. magneto (2 circuits for 2 sets of plugs). | Mechanical inlets. | Forced lubrication. | | <i>Features.</i>-- | | Steel cylinders (copper jackets). | Single cylinders. | Overhead valves. | Single cam shaft. | 2 carburetters (one for each pair of cylinders). | Crank shaft, solid, on ball bearings. | Open crank case. | | [Illustration] | +---------------------------------------------------- ~U.S.A.~ ------------------------------------------------------+----------------------------------------------------+----------------------------------------------------+---------------------------------------------------- ~ADAMS-FARWELL.~ | ~ALBATROSS.~ | ~CALL.~ | ~CURTISS.~ 21, Athol Street, Dubuque, Iowa. | Albatross Co., Detroit, Mich. | Aerial Navigation Co. of America, Girard, Kansas. | Curtis Aeroplane Co., Hammondsport, N.Y. ------------------------------------------------------+----------------------------------------------------+----------------------------------------------------+---------------------------------------------------- 36 h.p., 5 cyl., 102× 88 (1200 r.p.m.) 97 lbs. | 50 h.p., 6 cyl., 113×125 (1230 r.p.m.) 250 lbs. | 50 h.p., 2 cyl., 150×131 185 lbs. | 40 h.p., 4 cyl., (1100 r.p.m.) lbs. 63 h.p., 5 cyl., 142×127 (1200 r.p.m.) 250 lbs. | 100 h.p., 6 cyl., 137×125 275 lbs. | 100 h.p., 4 cyl. 325 lbs. | 75 h.p., 8 cyl., 100×100 (1100 r.p.m.) 250 lbs. 72 h.p., 5 cyl., 152×152 285 lbs. | | | also | Radial. The 50 is air-cooled, the 100 water-cooled.| | 60 h.p., 6 cyl., (1350 r.p.m.) lbs. Rotary horizontal. | | Horizontal opposed, water-cooled. | | | | 40 and 75, ~V~ shape, water-cooled (pump). H.T. magneto. | | | 60, vertical water-cooled (pump). Special valves. | | Mechanical inlets. | | | Magneto ignition (Bosch). | H.T. magneto (Bosch dual). _Features._-- | | Special silencer. | Mechanical inlets. | | Vanadium iron cylinders. | Splash and forced lubrication. No flywheel. | | Forced lubrication. | All valves in cylinder head, actuated by a | | | _Features._-- single push and pull lever worked by a | | | single cam. Valves close outwardly and | | _Features._-- | Single cylinders, copper jackets. are held shut by centrifugal force. | | | All valves in cylinder heads, actuated by rocking Variable lift. | | [Illustration] | levers from single cam shaft. Exhaust ports. | | | Mechanical oil feed. | | | [Illustration] | | | Engine weights are "fully complete." | | | | | | [Illustration] | | | ------------------------------------------------------+----------------------------------------------------+----------------------------------------------------+---------------------------------------------------- ~DETROIT AEROPLANE CO.~ | ~ELBRIDGE.~ | ~HALL-SCOTT.~ | ~KEMP (GREY EAGLE).~ Detroit Aeroplane Co., Detroit, Mich. | Elbridge Engine Co., 10, Culver Road, Rochester, | Hall-Scott Motor Car Co., San Francisco, Cal. | Kemp Machine Works, Muncie, Ind. | N.Y. | | ------------------------------------------------------+----------------------------------------------------+----------------------------------------------------+---------------------------------------------------- 30-40 h.p., 2 cyl., 127×127 (1200 r.p.m.) 110 lbs. | 40 h.p., 4 cyl., 123×114 198 lbs. | 30 h.p., 4 cyl., 100×100 142 lbs. | 1912 _models_: | 60 h.p., 6 cyl., 123×114 257 lbs. | 40 h.p., 4 cyl., 100×125 150 lbs. | 2 cycle horizontal, air-cooled. | | 60 h.p., 8 cyl., 100×100 235 lbs. | 35 h.p., D 4 cyl., 100×113 lbs. | Vertical, water-cooled. Valveless. Oil in gas. | 80 h.p., 8 cyl., 100×125 270 lbs. | 50 h.p., E 6 cyl., 100×113 260 lbs. H.T. magneto. | | 100 h.p. lbs. | Automatic inlets. | _Features._--Extra large bearings. | | 1913 _models_: Splash lubrication. | | First two are vertical, the others | | [Illustration] | V type, water-cooled (pump). | 16 h.p., G 2 cyl. lbs. _Features._-- | | H.T. magneto (Bosch). | 35 h.p., I 4 cyl. lbs. | | Mechanical inlets. | 55 h.p., H 6 cyl. lbs. All valves in cylinder heads operated by a | | Pump lubrication. | 75 h.p., J 8 cyl. lbs. single cam. | | | Valves easily detached. | | Cast-iron cylinders. | Vertical, air-cooled. Very large valves. | | All valves overhead. | Schebler carburetter | | Copper jacketted. | H.T. magneto. | | Special Stromberg carburetter. | Mechanical inlets. | | Special radiators. | Pump lubrication. | | | [Illustration: Over-all length of the 30/40 is 19 in.]| | [Illustration] | _Features._-- | | | | | | Overhead valves. | | | Extra large exhausts in centre of cylinders. | | | Special semi-steel (grey iron) cylinders. | | | Designed to work at 350°-400° Faht. | | | | | | [Illustration] ------------------------------------------------------+----------------------------------------------------+----------------------------------------------------+---------------------------------------------------- ~KIRKHAM.~ | ~MAXIMOTOR.~ | ~ROBERTS.~ | ~STURTEVANT.~ C. Kirkham, Savona, N.Y. | Maximotor Makers, Detroit, Mich. | Roberts Motor Co., Sandusky, Ohio. | B. F. Sturtevant Co., Hyde Park, Boston, Mass. ------------------------------------------------------+----------------------------------------------------+----------------------------------------------------+---------------------------------------------------- 45 h.p., 4 cyl., 105×120 (1400 r.p.m.) 180 lbs. | 50 h.p., 4 cyl., 113×127 ( r.p.m.) 200 lbs. | 50 h.p., 4 cyl., 113×125 165 lbs. | 40 h.p., 4 cyl., 113×113 (1300 r.p.m.) 200 lbs. 65 h.p., 6 cyl., 105×120 (1300 r.p.m.) 235 lbs. | 60-70 h.p., 4 cyl., 127×127 ( r.p.m.) lbs. | 75 h.p., 6 cyl., 113×125 (1100 r.p.m.) 240 lbs. | 60 h.p., 6 cyl., 113×113 ( r.p.m.) 285 lbs. 75 h.p., 6 cyl., × (1300 r.p.m.) 255 lbs. | 70-80 h.p., 6 cyl., 157×127 ( r.p.m.) lbs. | | 110 h.p., 8 cyl., 105×120 (1200 r.p.m.) 310 lbs. | 80-100 h.p., 6 cyl., ( r.p.m.) lbs. | Vertical, 2 cycle, water-cooled (pump). | H.T. magneto (Mea). | 100 h.p., 4 cyl., 150×150 ( r.p.m.) lbs. | | Mechanical inlets. Vertical, water-cooled (pump). | 150 h.p., 6 cyl., 150×150 ( r.p.m.) lbs. | H.T. magneto. | Pressure feed lubrication. | | Rotary inlets. | H.T. magneto (Bosch, 2 spark). | Vertical, water-cooled (pump). | Forced lubrication. | _Features._-- Forced lubrication. | | | | H.T. magneto (Bosch or Mea). | _Features._-- | Semi-steel cylinders (jackets cast with them). _Features._-- | Mechanical inlets (automatic in the 50 and 70.) | | Single cylinders. | Forced lubrication. | 2 carburetters. | Single cam shaft. Cast iron cylinders and pistons. | | Special magneto advance. | No overhead valves. Patent poppet-sleeve valves. | _Features._-- | Babbit bearings. | Exhaust valve lifters. | | Very large hollow crank shaft. | Nickel steel hollow crank shaft (5 bearings in [Illustration] | Started from aviator's seat. | Special metal cylinders (aerolite). | the 4 cyl., 7 in the 6 cyl.) | Double plugs. | Special by-pass. | | Half compression fitted. | Rotary inlets. | | Crank shaft, hollow, on 3 ball bearings. | | | | [Illustration] | ------------------------------------------------------+----------------------------------------------------+---------------------------------------------------------------------------------------------------- ~WELLES & ADAMS.~ | ~WRIGHT.~ | Wells & Adams, Bath, N.Y. | The Wright Co., Dayton, Ohio. | ------------------------------------------------------+----------------------------------------------------+ 50 h.p., 4 cyl. 200 lbs. | 30 h.p., 4 cyl., 112×100 (1650 r.p.m.) 190 lbs. | | 50 h.p., 6 cyl., 112×100 (1150 r.p.m.) 230 lbs. | Vertical, water-cooled (pump). | | | Vertical, water-cooled (pump). | H.T. magneto. | | Mechanical inlets (overhead). | H.T. magneto. | Forced lubrication. | Rotary valves. | | Pump lubrication. | ~Note.~ _Features._-- | Silencer fitted. | | | There are a good many other U.S. engines of Single cylinders (large brass jackets). | | little or no account. The majority of these are Double plugs. | | merely more or less accurate copies of well-known No valve cages. | | European engines, and none of them have any Chrome nickel crank shaft, on 5 bearings. | | vogue. | | ------------------------------------------------------+----------------------------------------------------+---------------------------------------------------- ~Part D.~ AERIAL "WHO'S WHO," DIRECTORY & INDICES. ~Note.~--So far as possible the directory lists are exhaustive for the entire world. Anyone accidentally omitted is requested to communicate with the Manager, _All the World's Air-craft_, 5, Queen Victoria Street, London, E.C. SUB-HEADS OF THIS SECTION. "WHO'S WHO" IN AVIATION. ~DIRECTORY:~ CARBURETTERS. FABRICS. GARMENTS FOR AVIATION. HANGAR AND SHED BUILDERS. INSURANCE. LUBRICANTS. MAGNETOS. MISCELLANEOUS ACCESSORIES. PACKERS AND SHIPPERS. PATENT AGENTS. PETROL. PROPELLERS. RADIATORS. ~INDICES:~ ALPHABETICAL AEROPLANES. " DIRIGIBLE TYPES. "WHO'S WHO" IN AVIATION. ADER (Clement), Chateau de Ribonnet, Beaumont-sur-Leze (Haute-Garonne, France). Born 1841. Officer Leg. d'Hon. Experimented from 1892. His _Avion_ flew 300 metres at Satory, 12th October, 1897. This was the first flight ever made by a power machine in Europe. One of his early machines is in the _Arts et Metiers_ Museum, Paris. ALEXANDER (H. I. H. Grand Duke), Michailovitch of Russia, Xenia Palace, St. Petersburg. Born 1866. Admiral of the Russian Navy. Prime mover in anything having to do with aviation in Russia. ALEXANDER (Patrick Y.), 2 Whitehall Court, London, S.W. Donor of the £1000 Patrick Alexander prize for British Aerial engines. Founder and supporter of various aerial clubs and societies. ANDRE (Ing. A.), 82 Rue d'Amsterdam, Paris. Editor _Revue Francaise de Construction Automobile et Aeronautique_. Writer on aviation. Experimenter. ARBUTHNOT (C. B.) (Major General H. T.) Chairman of the Aerial League of the British Empire. ARCHDEACON (Ernest), 77 Rue de Prony, Paris. Born 1863. Chev. Legion d'honneur. Vice-President _Ligue Nat. Aerienne_. Barrister. From 1884 made balloon ascents. In 1904 made glider experiments with Gabriel Voisin. Giver of the Archdeacon Cup, won by Santos Dumont, 29th October, 1906. Also part giver with Deutsch of the Deutsch-Archdeacon prize, for a Kilometre flight, closed circuit, won by Henry Farman, 13th January, 1908. ARNOUX (Réne), 45 Rue du Ranelagh, Paris. Born 1858. Vice-President Tech. Com. A.C.F. Designer of the electric motor of the _Tissandier_ dirigible, 1882. Member Soc. Civil Eng. and Soc. Internat. Elec. Contributor to _Omnia_, etc. Inventor of the _Arnoux_ biplane. ATTWOOD (Harry). Well-known American aviator. In August, 1911, covered 1,435 miles in eight days. AUFFM-ORDT. (Swiss). 2 Avenue Hoche, Paris. Pioneer Aviator. AVERY, American pioneer aviator, associated with Herring, Chanute, and others. BACON (_late_ Rev.), British prominent aeronaut and lecturer. BACON (Miss), daughter of the above. Aeronaut and lecturer. BADEN-POWELL (Major, B.), F.R.A.S., F.R. Met. Soc., late Scots Guards. 32 Prince's Gate, London, S.W. Inventor of the Baden-Powell Box Kite. President of the Aeronautical Society from 1902 to 1909. Early experimenter and investigator with aeroplanes. Lecturer. Editor of _Aeronautics_. BALDWIN (Capt. Thomas S.), 78 Maddison Square, New York. Well known U.S. Aeronaut of many years standing. Invented the _Baldwin_ dirigible. BALSAN (Jacques), 52 Quai Debilly, Paris. Born 1868. Aeronaut from 1905. Made an altitude record of 8,558 metres. In 1906 went by balloon, Paris to England. Vice-President _Aero Club de France_. BANNERMAN (Major Sir Alexander, Bart.) In command of the British Army Air Battalion, 1911. BARBER. British. Aeronautical Syndicate, 1909-12. _Valkyrie_ type, etc., etc. BARNWELL. British. Instructor 1912, Vicker's School. BARRA. Well known French aviator. BASENACH. German. Associated with Major Gross in producing the _M_ type German dirigibles. BARTON (Dr.) Built the first British dirigible in 1904. Capacity, 235,000 c.f. BATHIAT (Georges). Frenchman. After only one hour's tuition at the Hanriot School, secured his certificate at Rheims, October, 1910. Brother of the Bathiat who flew a _Breguet_. BAUMANN (Otto), Berlin. Second German to fly. BAUMANN. French. Instructor at the Ewen School in 1912. BEACHEY (Lincoln). American subject. In August, 1911, reached 11,578 feet (3,527 m.)--world's record to that date. Flew Niagara, 27th June, 1911, in a _Curtiss_. BEATTY (George W.) American aviator. At the Chicago meet, August, 1911, he made the world's passenger flight duration trip in 3 hours, 42 minutes, 22 seconds. Also made American records for 2 man altitude 3080 feet and 3 man duration on a _Wright_. BECKE (Captain). British Army. In December, 1912, made a (to that date) record flight--Flamborough to Plymouth, and later back again--4-1/2 hours out; 2 hours back, excluding landings en route. BEESE (Nellie). First German lady to get her pilot certificate, which she did on a _Rumpler_. BELL (Dr. Alexander Graham Bell). Canadian. One of the founders of the Aerial Exp. Assoc. in U.S.A. Began experiments 1894. Inventor of the Tetratedal, etc. BENDALL. British. Instructor Bristol School at Brooklands, 1912. BERGET (Alphonse). French subject. Professor Inst. Oceanographique. Past President Soc. Francoise de Nav. Ae. Author of _La Conquete de L'Air_. BERNARD. French. Tester for _Farmans_ 1912-13. BERRIMAN (A. E.) British. 44, St. Martin's Lane, London, W.C. Technical editor of _Flight_. Author of _Principles of Flight_, etc., etc. BERSON (Prof. Arthur), Haupstrasse 9, Lehlendorp, Germany. Born 1859. Austrian. Well-known author on meteorological and similar subjects affecting aviation. BESANCON (Georges), 35 Rue Francois I., Paris. Born 1866. Chev. Leg. d'Hon. Editor of _L'Aerophile_. Secretary Ae. C.F. Experimented with balloons from 1886 onward. BESSONNEAU (J. B. Lieut. de reserve), 29 rue de Louvre, Paris. French. Born 1880. Pioneer aviation helper. Produced special steel cables of high resistance; also the well known Bessonneau _hangars demontables_. Organised the first town-to-town flights, 1910; also first Grand Prix, 1912. BEZOLD (Professor Wilhelm Von), Director of the Meteorological Institute, Berlin, etc. Author of several works on aeronautics, etc. BISS (Gerald), British, 1, Melina Place, Grove End Road, London, N.W. Automobile correspondent of the _Standard_. Aviation expert. BLANCHARD. Frenchman. 1753-1809. First man to cross the English Channel in a balloon (1781). BLAND (Lillian E., Miss), Carnmoney, Belfast, Ireland. First woman aviator to design and build her own machine, _The Mayfly_. Has since ceased. BLERIOT (Louis), 56 Boulevard Maillot, Paris. Chev. Legion d'Honneur. Inventor of the _Bleriot_ monoplane. Pioneer. Experimented from 1906. Has had more falls than any other aviators. First man to fly the Channel, which he did in _Bleriot XI._, 25th July, 1909. Member, Com. d'Aviation of the Ae. C.F. BIELOVUCIC. Peruvian. Flew the Alps, 1912. Well known aviator. BISS (Gerald). 1, Melina Place, Grove End Road, London, N.W. Well-known writer on automobile and aviation. BOCKLIN. Swiss. 1827-1901. In 1850 became interested in aviation. In 1881 built gliders and a model aeroplane. Triplane, 1881. Biplanes, 1882-1887. In 1888 a monoplane with electric motor. BOLOTOFF (Prince), Reigate Priory, Reigate, England. Russian subject. Pioneer aviator. BOOM (J. A.) Editor of the _De Luchtvaart_, Ged. Aude gracht 144, Haarlem. BORGNIS (Achille), 48 Rue d'Université, Paris. Early experimenter and inventor. Vice-President of the Com. d'Aviation Aeronautiques Club de France. Member Ae. C.F. (See aviators.) BOOTHBY (Lieut. F. L. M.) British Navy. Served on board the _Hermione_ when she was mother ship for aviation and aeronautics. Holds certificates for both aeroplanes and dirigibles. BOSQUET (Chev. du), 8 Place de la Concorde, Paris. Chev. de l'Ordre de Leopold. Sec. Commission auto-aérienne. BOUTTIEAUX (Col.) In command French military aviation, 1911-13. BRACKE (Albert), 11 Chemin de Saint-Denis, Casteau-Mons, Belgium. Engineer. Editor _L'Aero Mecanique_. Inventor of the _Bracke_ and _Misson_ monoplane. Author on aerial matters. BREGUET (Louis Charles), 31 Rue Morel, Donai (Nord), France. Born 1880. Began experimenting June, 1906, and in July, 1908, his gyroplane flew 20 yards at a height of 14 feet. President de la Section du Nord de la Ligue Nat. Aérienne. BRERETON (J.). British. Instructor at British Deperdussin School, 1912. BREWER (W.). Author of a standard technical work, _The Art of Aviation_. Formerly manager of Grahame-White & Co. Writer on aerial matters. BRINDLEY (Oscar). American citizen. In August, 1911, he made 11,726 feet, at Chicago. These figures were afterwards stated to be incorrect, so the record was not allowed. BROOKINS, U.S.A. Up to August, 1910, held world's height record, 6,338 feet (1,922 m.), made in a _Wright_ at Atlantic City, U.S.A. Badly injured in an accident, August, 1910. BUIST (A. Massac). Well-known British writer on aviation subjects. Technical contributor to _Morning Post_, _Country Life_, etc., etc. BURGEAT (Captain). The first French Officer after Captain Ferber to take up flying. He purchased _Antoinette VI_.--the first _Antoinette_ sold to the public. BUSTEED (Harry). Australian. _Bristol_ pilot in the British Military Competition, 1912. BUTLER (Frank Hedges). F.R.G.S., 155 Regent Street, London, W. Founder of the R. Ae. C. Crossed the Channel in a Balloon 1905. Member Ae. C. F. BUTTENSTEDT (Carl). 95a, Friedrichshaven Str, Berlin. Born 1845. Author of aviation works and early experimenter over many years. Designer of aeroplanes, etc. CAILLETET (Louis Paul), 75 Boulevard S. Michel, Paris. Officer Leg. d'Hon. Doctor. President Ae. C. F. CALDERARA (Lieut.). Italian Navy. Sent to France to study aviation in 1908. Has made many good flights ever since. In 1912-13 produced a naval hydro-aeroplane of his own design. CAPAZZA (Louis). Frenchman. Born 1862. Head of the Clement-Bayard Works. CAPPER (Col.). Formerly in command of British Army aviation headquarters, Farnborough, 1909-10. CASSINONE (Alexander), Nordpolstr. 2, Vienna. Leading Figure in Austrian aeronautical circles. CASTAGNIERIS (Capt. Guido), 70 via della Muratte, Rome. Founder and secretary leading Italian aero clubs, etc. CASTILLON DE SAINT-VICTOR (Comte G. de), 74 Avenue Marceau, Paris. Born 1870. Aeronaut since 1898. Did a trip, Paris to Sweden. Treasurer Ae. C. F., 1911. CATERS (Baron de), Berchem-les-Anvers, Belgium. Born 1875. Motorist of renown in the early days. Early aviator pioneer. CATTANEO. Italian. Well-known aviator since 1910. CARDEN (Capt.). Experimental officer, appointed 1911, to British Army Air Battalion. CAUMONT (_late_ Lieut.). French aviator. Killed in a _Nieuport_ monoplane, December 30th, 1910. CAYLEY (George, Sir). Experimented about a hundred years ago with models and man-carrying gliders. Also wrote on Aviation, and is known as "the Father of Aviation." CHANDLER (Capt. C. de F.) Commanding Signal Aviation School, U.S.A. CHANUTE (Octave), U.S.A. Frequently alluded to as "the father of aviation." In company with Herring he joined Langley in 1905. He did much work with gliders. He propounded the theory that little was to be learned from studying birds. Discovered that the greatest lift was obtained from a plane flat in front and arched from the side. Died November, 1910. Aged 78. CHATLEY (Professor H.), B.Sc, Imperial Eng. Col. Tientsin, China. Britisher. Author of _The Force of the Wind_ (Griffin & Co.), and an authority on aviation matters in general. CHAVEZ (Georges). Peruvian aviator, resident in France. Maker of many records. First aviator to fly the Alps, 22nd September, 1910. Fatally injured on that occasion. CHEREAU. Frenchman. London manager of the Bleriot Co. and Bleriot School at Hendon. CHOENDEL (_late_). German aviator, who made an altitude record of 1680 metres with a passenger. Killed on alighting. CLEMENT (Gustave Adolphus), 33 Quai Michelet, Levallois-Perret (Seine), France. Born 1855. Officer Leg. d'Hon. Creator of the _Clement-Bayard_ dirigibles, etc. COCKBURN (Geo. B.), Gloucester, England. One of the first Englishmen to take up aviation. CODY. American; naturalised British, 1909. Inventor of the Cody kite. Employed by the British War Office for aviation work, 1905-1909. Inventor of Cody biplanes. Won Michelin prize 1910 and 1911. One of the best-known British aviators. In August 1912, made a biplane speed record of 72.4 m.p.h. Constructor. COLLOMB. Frenchman. Early experimenter with flappers, etc. COLMORE (Cyril). British. Ae.C. Pilot 15. Flying partner with the late Cecil Grace. Now given up flying. COLSMAN (Alfred), Friedrichshaven, Germany. Director of the Zeppelin Co., etc. CONNEAU (Lieut.) French Navy. Winner of the _Daily Mail_ £10,000 prize, 1911, with a _Bleriot_. Winner of the Paris to Rome and the Circuit of Europe races, 1911. Flies under the name of "Beaumont." CORNU (Paul), 24 Rue de la Gare, Lisieux, France. Pioneer experimenter with helicopters. In 1908 one of his inventions rose 16 inches. CROCCO (Lieut.) Italian. Had a good deal to do with the designing of the _Ricaldoni_ dirigible. CROOKSHANK (Major C. de W.), R.E. Prominent supporter of aviation. Member of the R. Ae. C. Committee, 1910-11. CURTISS (Glen. H.), Hammondsport, N.Y., U.S.A. Won the Gordon Bennett in 1909 on the _Curtiss_. Formerly a member of the Aerial Experiment Association, out of which the _Curtiss_ was evolved. Is Ae. C.F. Pilot 2. Head of the Curtiss Aeroplane Co. DAHLBECK (Lieut.). First Swedish naval aviator. Trained in England. DAVELNY. Commandant French Navy. Appointed 1911, to take command of French naval aviation. DAUCOURT. Frenchman. First pilot to fly from Paris to Berlin, 16th April, 1913. Average speed 100 k.p.h. Time 12 hours, 32 minutes, including two stops. DE BAEDAR (F.), 7 Rue Rameau, Paris. Editor _Revue Sportive de l'Aviation et de l'Automobile_. DE DION (Marqus), 104 Avenue des Champs Elysées, Paris. Born 1856. Principal founder and Hon. President Ae. C. F. DE HAVILAND (G.) British aviator. Designer of a biplane and a motor purchased by the War Office, in December, 1910. He was subsequently engaged by the Government for work on Salisbury Plain. In August, 1912, made the British altitude record to date of 9,500 feet with a passenger. DELAGRANGE (the _late_ Leon). Born 1872. French sculptor. Took up aviation early in 1907. He purchased _Voisin No. I._, which made its first trials 28th February, 1907. Subsequently engaged in experiments with Archdeacon. In 1908 bought a _Voisin No. III._ Later on got a _Bleriot_. Killed 4th January, 1910, at Croix d'Hins, Bordeaux, in a _Bleriot_. Was Ae. C. F. pilot 3. DEMANEST (Rene). French. 25, rue d'Orleans, Neuilly sur Seine. Began flying an _Antoinette_ in 1909. Won the Ae. C. F. prize. DEPERDUSSIN. (See machines). DEPREZ (Marcel). Frenchman. Writer on Aerial subjects. DESBLEDS (L. Bein). Lecturer on Aeronautical Engineering, Polytechnic, London. DEUTSCH (Henri de la Meurth), 4 Place des Etats-Unis, Paris. Officer Leg. d'Hon. Founder member of the Ae. C.F. Donor of the prize of 100,000 francs won by Santos Dumont, 19th October, 1901. Owner of the dirigible _Ville de Paris_. Vice-Pres. Legue Nat. Aérienne. Donor in part of the Deutsch Archdeacon prize. Offered 1909 to found a Technical Institute of Aviation, Paris University. DICKSON (Captain). Ex-British Army officer. The first British aviator to distinguish himself at an International flying meet. DOUTRE. French lawyer, interested in aviation. Invented a stabilising device in which Maurice Farman was interested. DREXEL (A.) Scotland. American citizen. Made world's record at Lanark, 12th August, 1910, in a _Bleriot_, 6,750 feet (2,057 m.), beating previous record of Brookins. DRIVER. British aviator. Flew in first aerial post, 1911. DRZEWIECKI (Stefan), 62 Rue Boileau, Paris. Russian. Born 1844. Chev. Leg. d'Hon. In 1885 investigated aviation in connection with bird flight. Well known otherwise as an inventor of submarines, torpedo tubes, etc. DU CROS (Harvey), M.P., 14 Regent Street, London, S.W. Born 1876. Takes considerable interest in aviation. Member of the Parliamentary Committee thereon. DUFAUX (Armand). Swiss. He and his brother Henry were interested in aviation in 1903, and in 1904 built an helicopter. In 1909 the first Swiss aeroplane built by them appeared. DUNNE (Lieut.), Eastchurch, Sheppey, Kent, England. Ex-British Army officer. Engaged by British War Office to carry out heavier than air experiments immediately after the aeroplane had been demonstrated a possibility. (See _Dunne_ in part I.) DUPUY DE LOME. Frenchman. Made a hand-propelled dirigible in 1870-72. DÜRR (Ludwig). German. Born 1878. Chief engineer Zeppelin works. DUTRIEU (Mdlle. Hélène). Belgian. Second woman to take up aviation. EFIMOFF (Michael). Russian. Made his first appearance in France early in 1910. (Ae. C. F. pilot 31). Distinguished himself on _H. Farmans_ and _Sommers_. On his return to Russia he was made chief instructor of the special school of the Volunteer Aerial Association. ELLEHAMMER (J. C. H.), Istedgade 119, Copenhagen. Commenced aviation studies in 1905. On 12th Sept., 1906, he made a flight--the first in Europe since Ader. ELLYSON (Lieut. T. G.) U.S. Navy. In company with Lieut. Towers made the first flights ever made in a hydro-aeroplane. ELY (Eugene B.) American. Was the first to fly successfully off a warship, which he did in a _Curtiss_ biplane on January 19th, 1911, from the U.S. cruiser _Pennsylvania_. Killed 1911. ENGLEHARDT (Kapitan). Prominent figure in German aeronautical and aviation circles. Writer on aerial subjects. Began flying in 1910, in which year he won several prizes. Killed 1911. EQUIVELLY (Marquis d'), 2 Place Wagram, Paris. Pioneer aviator, with a queer multiplane, 1907. ERBSLOCH (the _late_ Oscar). Well known aeronaut. Inventor of a German dirigible, the _R. M. W. G._, afterwards named after him. He was killed in it with four others, July, 1910. ESDAILE. British. Pioneered aviation displays in India, 1912. ESNAULT-PELTERIE (Robert), 149 Rue de Silly, Billancourt (Seine), France. Early experimenter with aeroplanes. Flew the first _R.E.P._, October, 1907. Designer of the _R.E.P._ engine. ESPITALLIER (Georges), 25 Rue St. Petersburg, Paris. Associated with the late Col. Renard in early dirigible experiments. Author of many aeronautical works. ETRICH (Igo), Rotunde, Vienna II. Pioneer aviator with Wels. Designer of the _Etrich_ monoplane--the first Austrian machine to fly. EVANS (William Evans), 1428, Charlotte Street, Kansas City, Mo. Purchased a biplane built by Dr. William Greene, who has since given up aeroplane building. Evans made a number of exhibitions in the middle West, but had given up flying by summer of 1911. EWEN (W. H.) British. Head of the School for British _Caudron_. "F. A. I." Federation of the leading Aero Clubs of all countries, for control of International Aviation Meets, Pilot certificates, etc., etc. The bulk of certificates were first obtained in France, but in 1910 they were made obtainable in any country from its own Ae. C., under identical rules. No aviator may compete in any International event without a certificate. Aviation has now more or less outgrown the F.A.I, on account of the virtual disappearance of private aviation events before military interests; but it did excellent service in its time and is still of considerable indirect value. FARMAN (Henri), 22 Avenue de la Grande Armée, Paris. Born in Paris, 1874, but is of English descent. Chev. Leg. d'Hon. First a racing cyclist, then racing motorist. Took up aviation. Bought _Voison No. II_ (known as "_Farman I._"). On January 13th, 1908, he won the Deutsch-Archdeacon prize for covering a triangular course of one kilometre. In 1909 designed and built his own machine. Won the Michelin cup in 1909, making the record of 4 h. 17 min. 35 2.5s. in the air. Ae. C. F. pilot 5. In 1910, did 8 h. 12 mins. in the air, covering 288-3/4 m. (463 km.) FARMAN (Maurice), 3 Rue Villaret de Joyeuse, Paris. Brother of above. Went in for aeronautics and motor racing. Bought _Voisin No. IV_ at an early stage of aviation. He fitted this with alterations of his own, and subsequently evolved the _M. Farman_ biplane. Ae. C. F. pilot 6. FAURE (Jacques), 32 Rue Washington, Paris. Born 1873. Has long been prominent in aeronautical circles. Has crossed the Channel five times in gas bag balloons. Owns the _Faure_ dirigible. Member of Committee Ae. C. F. FELIX (Capt.) In 1911 in charge of the Bleriot Military School at Etampes. FERBER (the _late_ Capitane), flew as "De Rue." Born 1862 at Lyon. Commenced experiments with gliders in 1899 on Lilieuthal lines. In 1903 he built a power-driven machine. He taught Gabriel Voisin how to fly gliders. In 1908 was very active and flew several machines. Killed in a _Voisin_, 22nd September, 1909. FERNANDEZ (the _late_). A Spanish tailor, resident in Paris, killed in 1909 in a machine of his own design. FISHER (E. U. B.) First flew on a _Hanriot_, early in 1911. August, 1911, engaged as pilot by Messrs. Vickers. FOKKER (Antony), Haarlem, Holland. Born in Java, 1890. Designed a monoplane in 1911 with special stabilising device. He flew this at Johannisthal. Subsequently started a company. FOURNY. French. On September 11th, 1912, broke all previous distance and duration records by flying, non-stop, 13 hours, 22 minutes in _M. Farman_. Renault motor. Distance 1,017 km. (631 miles) at Etampes, France. FRISBIE (J. J.) American aviator. Killed in a _Curtiss_ at Norton, Kan., having been driven to fly in unsuitable weather by the jeers of a hostile crowd. FÜRSTENBERG (Prince). Austrian. President of the Centre Aeronautical Committee, formed in June, 1912. GALANSCHIKOFF (Mdlle.) Russian. On November 22nd at Johannisthal, made world's altitude record for lady fliers with 2,400 meteres. GARROS. French aviator. Came in second in Paris to Rome and the Circuit of Europe races, 1911. Up to November, 1911, held world's height record (13,000 feet). Made in a _Bleriot_. GASNIER (René), 1 Rue Scribe, Paris. Winner of many prizes in balloon events. French champion for the 1907 Gordon-Bennett. On Committee of Ae. C. F. Hon. President Ae. C. d'l'Ouest. Inventor of an aeroplane, 1908. GAST (Madame C. Crespin du), 12 Rue Levoux, Paris. Well-known in aeronautical circles. GASTAMBIDE (Robert), 27 Boulevard de Courcelles, Paris. Born 1882. Civil engineer. Took great interest in aviation at the start. Designed the _Gastambide-Mengin_ from which _Antoinettes_ were evolved. This was the first monoplane to carry a passenger (September, 1908.) GELEYNS (C.) Editor of the _Avia_, Wynbrugstreet 13, Rotterdam. GERRARD (Lieut.), R.M.L.I. British. August 17th, 1911, made world's passenger record to date, 4 hours, 13 minutes, on _Short_ No. 34. GIFFARD (H.) Britisher, resident in France. In 1850 built the first practical dirigible. It had a steam motor. In 1852 it made a controlled speed of about 5 m.p.h. GILBERT. French. On March 28th, 1913, flew from Lyons to Villacoublay in 3 hours, 10 minutes, a world's record to date from town to town non-stop. GILL (Howard). U.S.A. aviator. In October, 1911, flew for 4 hours 16 minutes 35 seconds in a _Wright_. American record to that date. GILMOUR (Graham). British. Pilot Ae. C.F., April, 1910. In 1911, flying a _Bristol_: with which many of his flights have been directly or indirectly of a highly sensational nature. These have included a flight alleged to be over London (reported to R. Ae. C.--case dismissed), flying low over Henley Regatta (certificate suspended, with subsequent litigation). Won second prize in the Brooklands-Brighton Race, May, 1911. Killed February, 1912. GIBERT. French aviator who made records, 1911. GLAZEBROOK (Dr. R. T.), C.B., F.R.S. Director of the British National Physical Laboratory. GLIDDEN (Charles J.) The well-known American motorist. Founder of many of the U.S.A. Ae. clubs. GODARD (Louis), 170 Rue Legendre, Paris. Builder of the _America_ Wellman Arctic Airship; inventor of the Godard Kite-Balloon; designer and builder of the _La Belgique_, etc., etc. GORDON-BENNETT (James), 104 Avenue des Champs Elysees, Paris. American citizen. Owner of the _New York Herald_. Giver of the Gordon-Bennet aviation Prize. Previous to this he had instituted a similar event for motor cars, and few, if any, have done so much to advance the International sporting side of automobilism. GOUPY (Ambrose), 59 Avenue Marceau, Paris. An early pioneer in aviation experiments--had the first triplane built for him by _Voisins_. Now a well known constructor. GRACE (_late_ Cecil). Naturalised British subject, ex-Chilian. Lost at sea while competing for the Baron de Forest prize, December, 1910. GRADE (H.), Magdeburg, Germany. First man to fly in Germany. He did this on a Grade triplane early in 1909. Now a well known German constructor. GRAHAME-WHITE (Claude), 1 Albemarle Street, Piccadilly, London. Pilot 30 Ae. C. F. on a _H. Farman_. Attempted to win the _Daily Mail_ £10,000 London-Manchester prize, 1910. Gordon Bennett, 1911. Now constructor. GREENE (Dr. W.), Treasurer, Aeronautic Society, U.S.A. Has done a great deal to advance aviation in the U.S.A. Designer of the _Greene_ biplane--a machine which in no way infringed the Wright patents. GRESWELL. British aviator. Flew in first aerial post, 1911. GREY (Chas. G.), 166 Piccadilly, London, W. Editor of the _Aeroplane_. Well-known writer on aerial matters, formerly as "Aero-Amateur," later under his own name. By 1912, had come to occupy a unique position of his own by an uncompromising statement of facts without regard to other circumstances. GROSS (Major). In command of the German war dirigibles. Designer of the _M_ type. (_Gross_). GRUBB (Capt. A. H. W.) D.S.O., R.E. Prominent supporter of aviation. Member of R. Ae. C. Committee, 1910-11. GUILLEMEAU (R.), 82 Rue d'Amsterdam, Paris. Editor _Revue Francaise, de Const. Autble et Aeronautique._ HAENLEIN (Paul). German, 1835-1905. Early experimenter with dirigibles. Inventor of the "semi-rigid" system. HAMEL (Gustav). British. Well-known aviator. Winner of Brooklands-Brighton Race, May, 1911. Flew the first British aerial mail, 1911. In April, 1913, on behalf of the London _Standard_, made a non-stop flight with a passenger London to Cologne in a _Bleriot_. Many other famous flights. HAMMOND (J. J.) Australian. Pilot 258, Ae. C. F., on a _Sanchis Besa_, 4th October, 1910. In 1911, visited Australia with a _Bristol_, when he made many sensational flights. HARGRAVE (Lawrence), Sydney, N.S.W., Australia. A pioneer in aviation, 1890-95. Experimenter with and inventor of box kites. HARKNESS (Harry). American aviator. Has made various records. HARMON, (Clifford B.) One of the best-known U.S.A. amateur aviators. Made U.S.A. time record (2h. 3m.), 2nd July, 1910. HARRISON (Eric). Australian subject. Instructor of the Bristol school at Lark Hill, Salisbury Plain, 1912. HARRISON (Lieut. L. C. R.) British R. F. C. Killed 28th April, 1913, in the famous _Cody_ which won the British Military Aeroplane competition. HAULT (Adhemar de la), 214 Rue Royale, Brussels. Editor of _La Conqûete de l'air_. Well-known aviation pioneer. Interested in Ornithopters. HAWKER (H. G.) Australian subject. On October 24th made British duration record to date--8 hours 23 mins. in _Sopwith_ biplane. Awarded the Michelin Cup, 1912. HEKKING (R.) Frenchman. In September, 1909, carried out experiments with a biplane glider of 7 m. span and 25 m². surface. He rose to a height of 25 m., and is stated to have remained stationary for 5 minutes. Not confirmed, however. HELEN. French aviator. Has appeared in various competitions since early in 1911. HENDERSON (Brig. Gen.) British Army. First general to obtain British R. Ae. C. aviator certificate. Flying under the name of "Davidson" he obtained his certificate on a _Bristol_, at Brooklands, after seven days' training. HENRY, Prince of Prussia. Well known for practical interest in motoring and aviation. Has driven his own car in races, and is a certificated aerial pilot for Germany. HENSON. Died 1842. Projected a steam-driven monoplane early in the XIX century. HERRING (A. M.), Freeport, Long Island, U.S.A. Started the study of aviation 1894. With Langley, 1895. With Chanute, 1896. Joined Ae. Exp. Assoc. and associated with Curtiss in the _Herring-Curtiss_. Subsequently (1910) with Burgess in the _Herring-Burgess_. HERVE (Henri), 1 Rue Hautefeuille, Paris. Well-known authority on matters aeronautical. Author, etc. HEWLETT (Mrs. Maurice) ("Madame Franck"). First lady aviator to obtain a British R. Ae. C. certificate. HILDEBRAND (Kapitan Alfred), 10 Martin-Lutherstrasse, Berlin W. 30. Retired from German Army. A very well-known aeronaut. Owner of a Baldwin dirigible. Author of many works on aeronautics and aviation--the best known German writer on these subjects. HINTERSTOISSER (Hauptmann Franz), Luisenstrasse 35, Vienna V. Commanding Austro-Hungarian Aeronautical service. 1911-12. HIRTH (Helmuth). German. Made German passenger altitude record to date, at Johannistal, September-October, 1911. Height 2475 metres. Many other records. The best known of all German aviators. HOFFMAN (Joseph). German. Built a steam-driven aeroplane in 1906. HOLDEN (Col. H. C. L.) R.A.F.R.S. Prominent supporter of aviation. Member of the R. Ae. C. Committee, 1910-11. HOWARD-FLANDERS. See British Aeroplanes, Part A. HOWARD-WRIGHT. British. Early designer (_see_ Part B). In January, 1913, became manager of S. White & Co., of Cowes. HOUDINI (Harry). British. The famous "Handcuff King" flew a _Voisin_ so long ago as November 2nd, 1909. He took it to Australia and won the first aeroplane flight prize there. He is the first to have taken out a "third party" insurance, which he did with the Albingia-Versicherungs-Aktien-gesellschaft, Hamburg, Germany, on November 29th, 1909. The policy was for 150,000 marks. HUBERT. French aviator. Flew in the first British aerial post and was badly injured. HUCKS (B. B.) British aviator. Has made several fine exhibition flights on a _Blackburn_. First man to make the double journey across the Bristol Channel, also to carry out wireless telephone experiments with aeroplane. HUNTINGDON (Prof. A. K.), 14 Buckingham St., Charing Cross, London, W.C. Born 1856. Balloon expert, 1906-1908. Connected with the _Dunne_ machines. Member of the R. Ae. C. Committee, 1910-11. HURLBERT (Dr. Dane), Vermont, Lucerne, Switzerland. U.S.A. citizen. Experimenter in original types of aeroplanes, 1909-11 ILLNER. First man to fly in Austria, which he did on an _Etrich_. ISSATIER. French private soldier who obtained three weeks' leave and secured his flying certificate at Betheny after fourteen days, in a _Deperdussin_. ISENDAHL (Walther). German. Holsteinstrasse 21, Berlin-Wilmersdorf. Leading authority on aerial and boat motors. JANE (Fred T.), The Hill, Bedhampton, Hants, England. Naval author, founder and editor of _All the World's Air-craft_. JANNUS (Antony). American. Well-known aviator. JATHO (Karl), Stader Chausse 22, Hanover, Germany. Born 1873. Pioneer aviator from 1893. Has built various machines--none very satisfactory. JEANNIN (Emil), Berlin. Prominent German aviator. JEFFERIES (Dr. John). 1760-1820 _about_. American. Accompanied Blanchard in the first balloon voyage across the English Channel, 1784. JENKINS (F. Conway). In May, 1911, obtained his certificate (74) after only four flights on a _Roe_ biplane. JOHNSTONE (St. Croix). American aviator. 27th July, 1911, beat American duration records in a flight of 4 hours, 1 minute, 54 seconds. Distance 176 miles. Killed 1911. JONES (Ernest L.), 250 West 54 Street, New York. Editor of _Aeronautics_ (U.S.A.) JOSEF FERDINAND (Grand Duke of Austria). Enthusiastic aeronaut and moving spirit in aviatory matters in Austria. JOYNSON-HICKS. British M.P. who has specialised in endeavouring to advance aviation. JULLIOT (Henri), 3 Rue de Flandre, Paris. Born 1855. Chev. Leg. d'Hon. Technical director of the _Lebaudy_ works. Originator of the _Lebaudy_ type of dirigibles. Designer of _Lebaudy_ aeroplane. Member of Committee Ae. C. F. KAPFERER (Henry), 26 Rue de Clichy, Paris. Chev. Leg. d'Hon. Director of the _Astra_ Cie, and the Cie Gen. Transaerienne. Part designer of the Clement-Bayard dirigibles. Took an early interest in the aeroplane movement, and had a biplane built to his own design by Voisins in 1907. Also had an early monoplane about the same date or a little later. On Committee Ae. C. F. KASSNER (Carl), Wilhelmstr. 10, Berlin. Professor, German writer on technical aviation matters. KENNEDY (Rankin), British authority on aviation subjects. KENNEDY. St. Petersburg. British subject. Engineer who has studied aviation for many years. In 1911, was an honorary aerial adviser to the Russian Government on matters aerial. KINDELAN (Captain), Guadalajara, Spain. Born 1879. Interested in balloons since 1906. Designer of the Spanish military airship _Torres Quevedos_. KNIGHT. British. Instructor 1912, Vickers School. KOENIG. German aviator. Won the 1st prize given by the Berliner _Zeitung am Mittag_. 1,182-1/2 kilos. KRAUSS. Well-known German aviation engineer. Author of many articles. KRESS (Wilhelm), Waaggasse 13, Vienna. Born 1836. Flew a model ornithopter in 1888. Author. KRIEGER (Hans). German. Formerly chauffeur to the Kaiser. Built a monoplane of his own design, and on September 5th, 1911, obtained his certificate on it. LAFFONT (_late_ A.) Killed in an _Antoinette_, December 28th, 1910. LAHM (Frank), Washington D.C., U.S.A. Well-known aeronaut. LAMBERT (Albert B.) President of Ae. C. of St. Louis, U.S.A. Flies a _Wright_. LAMBERT (Count Charles), 74 Rue Charles-Lafitte, Neuilly-sur-seine, Paris. Russian subject. Born 1865. Interested in aviation 1893 onward. First pupil of Wilbur Wright. LAMMLIN. German. Killed at Strasburg, May 23rd, 1911. LANA (Francisco), (1631-1687), (Italian). Jesuit who projected flying machines. LANCHESTER. Author of well-known aerial classic. LANE (Howard), 50, Parliament Street, Westminster, London, S.W. British citizen. Mechanical and Chemical Engineer. Born 1852 at Warwick. Government Contractor; Birmingham City Councillor, 1895-1900. Honours, South Kensington, 1873. Inventions, the Seamless Steel Gas Cylinder, 1882; Multiple Stage Gas Compressor, 1884; Roller method of Skin Balloon Construction, 1887; Regenerative Hydrogen Producing Plant, 1903; Turbine Aero-Motor, 1909, etc., etc. LANGLEY (Samuel Pierpont). Born 1834. Died 1906. American pioneer from 1887. Commenced work in 1893 with Dr. Graham Bell, and later, Herring and Chanute. In May, 1896, he flew a large steam-driven model tandem monoplane--the _Langley_ type. Author of _Experiments in Aero Dynamics_ and other aerial classics. LANZ (Karl), Lachnerstrasse 18, Mannheim, Germany. Wealthy patron of aviation in Germany. Giver of the £2000 Lanz prize won by Grade. Financed the _Schütte_ dirigible. LAROCHE (Madame la Baronne Raymonde de). The first lady aviator. Pilot Ae. C. F. 36. Purchased a _Voisin_ in the summer of 1909 and entered for International events. Badly injured in an accident at Reims, July, 1910. In 1913, took up flying again. LATHAM (Hubert), 7 Rue Rembrandt, Paris. Of English descent one side. Pilot 9 Ae. C. F. Director of the _Antoinette Cie_. Attempted to fly the Channel, 1909. (1) in _Antoinette IV_. (2) in _Antoinette VII_. (3) in August, 1910. Maker of many records. Killed by a buffalo, 1912. LA VAULX (Comte Henri de), 2 Rue Gaston de St. Paul, Paris. Born 1870. Chev. Leg. d'Hon. Vice-President Ae. C. F., and one of its promoters. Founder and Vice-Pres. of the F.A.I. Took up aeronautics in 1900, since when he had made over 250 ascents. Record holder for "gas bags." Owner of a _Zodiac_ dirigible in 1909-10. LEBAUDY (Robert), 12 Rue de Lubeck, Paris. Sugar refiner. Member Ae. C. F. Founder of the _Lebaudy Dirigible Cie_. LE BLANC (Alfred), 17 Rue Lakanal, Paris. Born 1869. Aeronaut in 1904. Winner of the _Circuit d' l'Est._, Aug., 1910. LE BLON (_late_). Frenchman. Born 1875. Killed in a _Bleriot_ at S. Sebastien, 2nd April, 1910. LEFÈBVRE (Eugene). French aviator. Killed on a _Wright_, 7th September, 1909, at Juvissy. LEGAGNEUX. In December, 1910, made a flight of nearly 6 hours, at Pau, (322 mile--53 m.p.h.) average, in a _Bleriot_. LESSEPS (Comte Jacques de), 11 Avenue Montaigne, Paris. Well-known aviator in the early days. LEVAVASSEUR. Known in France as "Pére Levavasseur." Chief engineer of the Antoinette Works and _deus ex machina_ of the type. He severed his connection early in 1910, but rejoined in June, 1910, and remained as long as the company existed. LEVE (Pierre), 17 Rue Cassette, Paris. Editor of _La Revue Aérienne_, official organ of _La Ligue Nat. Aérienne_. LILIEUTHAL (Gustav), 5 Marthastrasse, Gross-Lichterfelde, Germany. Brother of the late Otto Lilieuthal, whose work he has carried on. Author. LILIEUTHAL (Otto, the _late_). German subject. Began his interest in aviation when 15 years old. In 1889 published his _Bird Flight as a Basis of the Flying Art_, the result of 25 years observation of sea-gulls and storks. In 1891 he made glider flights. In 1895 he produced a biplane glider. On 12th Aug., 1896, he was killed while experimenting. Lilieuthal was the fountain head of modern aviation. LINKE (Dr. Franz), Kettenhofweg 181, Frankfurt, Germany, Scientist. Born 1878. Author of _Moderne Luftschiffahrt_ and other works. LIORE (F.), 4 bis Rue de Corneille, Levallois-Perret, France. Early pioneer with the _Witzig-Liore-Duthileuil_. Since then evolved a monoplane. LÔME (Dupuy de). See DUPUY DE LÔME. LORIDAN. In July, 1910, in a _H. Farman_ racer broke the existing altitude record by making 3,280 m. (10,758ft). Did 702 km., July, 1911. MALONE (Lieut. Cecil J. L'Estrange). R.N. Navy Wing of British R. F. C. Assistant to director of Flying at Admiralty, end of 1912. MAHIEU. In September, 1911, made the world's passenger record of 2460 metres (7981 feet) in a _Voisin_, at Issy. Duration of flight 3-1/2 hours. MANNING (H.) British. Aeroplane designer. MAREY (Professor). Inventor of the Whirling table, 1870. MARIE (Capitaine). French Army. On staff of Inspector General of Aeronautics. MARIE (Pierre). Alsatian. Real name was Bournique. He made his name on a _R.E.P.'s_. In May, 1911, he was trying a 100 h.p. _Deperdussin_ when the machine capsized and fell. He was taken to hospital and died a few hours later. His passenger, Lieut. Depuis, was burned to death. MARS ("Bud"). Well-known American aviator. Has more than once been reported killed; but always appears again. MARTIN (Glen L.) Santa Ana, California, U.S.A. Flying _Curtiss_ types. Obtained a considerable reputation, and local amateur record at Los Angeles meet, end of 1910. MASSAC BUIST. (See BUIST). MATSIEVITCH (Kapitan). Russian Army. Was Instructor of the Military Aviation School at Sevastopol. Killed at Sevastopol, 1911. MAXIM (Sir Hiram), Baldwyn's Park, Kent. Inventor of the Maxim gun, etc. American by birth, naturalised British subject. Began experiments with propellers, etc., in 1889. In 1890 to 1893 he experimented with a full-sized aeroplane, steam propelled. Abandoned the experiments after spending £20,000 on them. Resumed work 1909, without success. Author of _Artificial and Natural Flight_. McCLEAN. British aviator. Towards the end of 1910, he loaned two _Short_ biplanes to Eastchurch flying ground for the training of naval officer in aviation, and himself acted as instructor. These were the first machines used by the British naval officers, consequently Mr. McClean may be regarded as the founder of the British Naval Aeroplane Division. Member of the R. Ae. C. Committee. MENGIN (L.), 2 Rue Debrousse, Paris. Born 1881. Early experimenter. Flew in 1908 in the _Gastambide-Mengin_, from which the _Antoinette_ was evolved. Director of the late _Antoinette Cie_. MERRIMAN. British. Expert Bristol flyer at Brooklands, etc., 1912. Instructor. MESSNER (Haupt. E.), Claridenstr. 36, Zurich. In command Swiss military aviation section, 1911-12. MICHELIN (A. J.), 105 Boulevard Periére, Paris. Born 1853. Chev. Leg. d'Hon. Director of the well-known tyre manufacturers. Donor of the Michelin prize for aviation. Founder member Ae. C. F. MOEDEBECK (Hermann W. L.) Born 1857. Died 1910. German author on aerial matters. MOEDEBECK (Lieut. Col.). German subject. Author of _Fliegen de Menschen_ (Salle), a very useful work on aviation. Also of a _Pocket Book of Aeronautics_, etc. MOINEAU. Frenchman. In August, 1911, with two passengers made a record on a _Breguet_, of reaching 900 metres in twenty minutes at Douai. MOISANT (Miss Matilda). Sister of the late J. M. Moisant. Second American lady to obtain certificate. Used a _Moisant_. MOISANT (John). Architect. American citizen, resident in Paris. Invented two monoplanes. In Aug., 1910, flew the Channel with a passenger in a _Bleriot_. This was the first cross-Channel passenger trip. Killed 1911. MONTAGU (Lord), of Beaulieu. Editor of _The Car Illustrated_. Prominent in arousing British interest in aviation. MONTGOLFIER (Joseph Michael and Jacques Etienne). Frenchmen, who about the year 1780 invented hot air balloons. In 1783, one such, of 35 feet diameter, rose to a height of about 1,500 feet. MONTGOMERY (John Professor), U.S.A. citizen. Began experiments with gliders in 1884, which he continued till his death by accident with one, on 31st October, 1911, at Evergreen, Santa Clare, California. MOORE BRABAZON (J. T. C.), 29 Chesham St., London, S.W. Born 1884. Originally sporting motorist; winner Circuit des Ardennes, 1907. Took up aviation at an early stage. Bought an early _Voisin_ which he named _Bird of Passage_. This machine was later sold to A. George, who had a smash in it, and sold it later to Grace. Moore Brabazon was the first Britisher to fly. Pilot I, R. Ae C. MOORHOUSE (W. B. R.), Portholme Aerodrome, Huntingdon. British. Has done a good deal of cross country flying, 1911. Part inventor of the _Radley-Moorhouse_ (R. M.) monoplane, 1911. MORANE (Leon). Frenchman. Well-known _Bleriot_ pilot. Subsequently built the _Morane_ monoplane. Very badly injured in an accident, Autumn, 1910. MOREAU. French amateur. Inventor of a special stabilised aeroplane. MORIS (Colonel). Commanding Italian air battalion, 1911-13. NEMETHY (Emil), Arad, Hungary. Born 1867. Built his first effort, a helicopter, in 1899. Has experimented ever since, but without much success. Inventor of the _Aviette_. NEUMANN. Germany. Author of various very reliable works on dirigibles. NICKEL (Hugo Ludwig), Kahlenbergerstrasse 97, Vienna. Born 1867. Aerial author and journalist. NIMFÜHR (Dr. Raimund), Lerchengasse 15, Vienna. Born 1874. Experimentalist 1900 onward. Author. NORTHCLIFFE (Alfred Charles Harmsworth) Lord. British subject. Founder and proprietor of the "Daily Mail." Donor of many important aviation prizes, including the £10,000 London-to-Manchester prize. OERTZ (Max), Holzdamm 40, Hamburg, Germany. Interested in gliders. Connected with German North Pole Dirigible Expedition. Designer of various aeroplanes. OGILVIE (A.) Represented Great Britain in both the 1910 and 1911 Gordon Bennetts. Took fourth place in 1911. Average speed, 51 miles per hour. Flew a _Wright_. In December, 1910, flew for nearly 4 hours on a _Wright_ over the Camber sands; distance being 139-3/4 miles. Associated with the Wright Brothers experiments at Kitty Hawk, October, 1911. O'GORMAN (Mervyn). Well-known authority on aviation matters, and Superintendent of the Royal Aircraft Factory. OSMONT. Frenchman. Formerly racing cyclist. Did some fine flights at Chalons in 1910. In February, 1911, appointed chief aviation instructor to the Spanish Army. OTTO (Fried), Hohenstaufeurstrasse 35, Berlin. W. 30. Aerial journalist, etc. OVINGTON (Earle). U.S.A. aviator. Carried first U.S.A. aerial post, Sept 1911. Winner of many prizes in America. OXLEY. Instructor to the Blackburn School, at Filey, 1911. PAINE (Capt. G. M.) M.V.O., R.N. Commandant of the British Central Flying School at Upavon, Salisbury Plain. Appointed early in 1912. PARKE (Lieut. Wilfred, R. N.) Started flying in 1910, and made a large number of meritorious performances. Killed in a monoplane at Wembley, December 15th, 1912. PARSEVAL (Major Von), _late_ German Army. Inventor of the _Parseval_ type dirigibles and the _Parseval_ monoplane. Leading figure in all aerial matters in Germany. (See Part A.) PATERSON (Compton). British aviator. Liverpool Motor House, Ltd., Liverpool. Designed a successful machine in 1909. Also flies _Farmans_. Designed new machine 1911. PATIALA (Maharajah of). In December, 1910, purchased a _Bleriot_ and a _Voisin_. Member of the R. Ae. C. PAGNY. French. Designer of _Hanriots_, 1913. PAULHAN (Louis). Frenchman. Born 1883. Served afloat as a boy. Later served with the _late_ Col. Renard; also with the _late_ Captain Ferber. In 1907 was with Surcouf. In his spare time he made models. In 1909 he won a _Voisin_ biplane, given as prize for the best model in France, and rapidly came to the front. In 1910 he won the _Daily Mail_ £10,000 prize for the London to Manchester flight. Numerous other prizes have been won by him. Took up construction in 1911 without much success till in 1912 he took over French, etc., agency for _Curtiss_ hydros. PEQUET (H.) Frenchman. Certificated June, 1910. Flew a _Humber-Sommer_ in India, where he conveyed the first officially recognised aerial post at Allahabad. PERRIN (H.) British. Secretary of the R. Aero Club. PERRY (Ida), Metropol Theater, Berlin. German actress, who has gone in for aviation. PFITZNER (_late_ Lieut. Alexander L.) Hungarian. Born 1875. Served in the Austro-Hungarian Artillery. Leaving the Army he went to the U.S.A. and became connected with the Herring-Curtiss work, designing the novel Pfitzner monoplane. He met many mishaps with this, which depressed him. He returned to Hungary early in 1910, but meeting no success there came back to America. Drowned in Marblehead Harbour, 12th July, 1910. PHILLIPS (Horatio F.), Wealdstone, Harrow. Pioneer experimenter. Discoverer of the "dipping front edge," patented by him 1884 and 1891. ("Philips' entry.") Leading authority on aviation subjects. PICKLES (Sydney). Australian. Chief pilot at the Ewen school at Hendon, 1912. PICHAN (Court). Early French experimenter. Flew a flapper model 1889. PICOLLO (_late_ Jules). Brazilian aviator. Killed December 28th, 1910. PIERRE (Petit). Frenchman. The _late_ secretary of Bleriot School at Hendon. Assassinated at Hendon, August, 1911, by a Swiss pupil named Hanot, who went insane at not learning to fly so quickly as he had expected. PILCHER (_late_ Percy S.) Born 1866. British naval engineer. Commenced glider experiments, 1895, on Lilieuthal lines. Designed a power machine in 1899, but was killed in glider experiments before it was completed. PIXTON (H.) British R. Ae. C. pilot 50. Qualified at Brooklands, January, 1911, on a triplane. Has since done some very fine flights on an _Avro_, taking various prizes. PISCHOFF (Alfred de), 12 Rue Amiral de Joinville, Paris. In conjunction with Koechlin was a pioneer of French aviation. In December, 1907, he flew a kilometre on a biplane. His earliest machine was practically a large box kite with a motor fitted. In 1910 produced a monoplane of his own design. He is an Austrian resident in France. POPPER (Josef). Austrian. Concerned with aviation, etc., ever since 1872. POLLOCK (C. F.) Prominent supporter of aviation. Member of the R. Ae. C. Committee, 1910-11. PONNIER. Frenchman. Director of the Hanriot Company. PRANDTL (Dr. Ludwig). Prinz Albertstrasse 20, Göttinger, Germany. Born 1875. Leading Figure in German aerial circles. Connected with the _Parseval_ design. PREVOST (M.) French. Created world's record on December 2nd, 1911, by reaching a height of 9,800 feet at Rheims. PRIER (Pierre). Made London-Paris in 3 hours, 56 minutes, 12th April, 1911. Designer to the _Bristol_ Co., 1911. QUEROZ (the _late_). Brazilian. Killed at S. Paulo, June, 1911, in a monoplane of his own design. QUIMBY (Miss Harriet). Mineola, U.S.A. First American lady to qualify for aviator certificate, 1st August, 1911. Used a _Moisant_. Killed 1912. QUOIKA (Haupt. Emanuel), Margarethenstrasse 16, Vienna. Aeronaut from 1904. Now aviator and writer on subject. RADLEY (James). Well-known British aviator, flying a _Bleriot_. Patented a special wing. Represented Great Britain in the 1910 Gordon Bennett. At Lanark, 1910, broke the world's then speed record, and did 75 miles per hour. Pilot R. Ae. C. 12, June 14th, 1910. August, 1911, flew the Channel in 22 minutes; Calais to Folkestone. Subsequently embarked on construction. RAYNHAM (F. R.) British subject. Flew 7 hours, 30 mins. competing for the Michelin Cup. Used an _Avro_ fitted with a 60 horse Green. REISSNER (Dr. Ing. Hans), Lutticherstrasse 166, Aachen. Born 1874. Professor on matters aerial. RELTICH. French. Cyclist who succeeded in getting an avietter to fly one metre, October, 1912. Won the Dubos prize. RENARD (_late_ Colonel). In association with Krebs built a dirigible in 1884, with electric motor. Killed. RENARD (Commandant Paul), 41 Rue Madame, Paris. Born 1854. Officer Leg. d'Hon. Brother of late Col. Renard, with whom he worked. Vice-President, _Ligue Nat. Aerienne_. Professor _Ecole Sup. d'Aeronautique_. Has written a good deal on aerial subjects. RENAUX. Did 12 hours 12 minutes on a _M. Farman_, 7th August, 1911. (690 k.m.) Won the Quentin Bauchart Prize, 1911. RENAUX. French aviator. Winner of the Grand Prix Michelin, March, 1911, Paris, to top of the Puy de Dome. Machine, _Maurice Farman_. RICHET. French patron of early aviation experiments, 1896. Tatin built a large model machine for him in those days, which after a 150 yard flight fell into the sea and was lost. RIDGE (Theodore). Assistant Superintendent of the Army Aircraft Factory. Killed on August 21st, 1911. ROBINSON (Hugh). Well-known U.S.A. aviator. ROBL (_late_ Thaddeus). German aviator. Killed on a _Farman_, 1910, through attempting to fly in unpropitious weather in order to allay the complaints of sightseers. Has been designated the "first martyr of aviation"--not without some cause. RODGERS (C. P.) U.S.A. aviator. _Wright._ In September-October, 1911, he flew across America, distance 4,321 miles. He started to win the Hirst prize of £10,000, but having taken longer than 30 days was disqualified. ROE (A. V.) Clifton St., Miles Platting, Manchester. Was the first man to fly in England, and also the first to fly an all-British machine. Is a persistent experimenter on original lines. Has flown with as little as 9 h.p. in one of his triplanes. Now builds mono. and biplanes (_Avro_). ROEHRIG (B. F.) U.S.A. aviator. Obtained wide reputation with _Curtiss_ types on Pacific Coast. ROGER, 8 Rue Grange-Batelière, Paris. Founder and editor of _Revue de l'Aviation_. ROGUES (General). French Army. Inspector General Military Aeronautics, 1911. ROLLS (_late_ Hon. C.) Well-known British sportsman, motorist, and aviator. First Englishman to order an aeroplane--a _Wright_. Flew the Channel both ways early in 1910 (first record). Killed at Bournemouth, July, 1910, in a _Wright_. RUCK (Major-General), C.B., R.E. Chairman of the Aeronautical Society of Great Britain. RUSSIJAN. Austrian aviator. Killed January 9th, 1911. SALMET (Henri). French. Born 1878. Made British height record, 8,070 feet, November, 1911. Made record London-Paris flight, March, 1912. Time: 3 hours, 14 minutes. SAMPSON (Lieut.) British Navy. On August 17th, 1911, made British flight duration record to date, 4 hours 58-1/2 minutes, at Eastchurch on a _Short_ 38. Now Acting-Commander. Employed by Naval Wing, R.F.C. SAMUELSON (Arnold), Hamburg Waterworks, Germany. Born 1837. Writer on aerial matters. SANTOS-DUMONT (Alberto), 150 Avenue des Champs-Elysees, Paris. Brazilian, of French descent. Born 1873. Officer Leg. d'Hon. Took up ballooning at an early age. He was the first to use a petrol motor in a balloon. In 1900 the fifth dirigible constructed by him crossed the Seine. On Oct. 19th, 1901, in No. 6, he circled the Eiffel Tower and won the 100,000 franc Deutsch prize. In 1906 he became interested in heavier than air machines, and began on a helicopter. Abandoning this he built a box kite type of aeroplane, and on October 23rd, 1906, won the Archdeacon prize for a heavier than air flight of not less than 25 metres. Thereafter, comparatively little was heard of him, except that he was experimenting with the _Demoiselle_, till in 1909 he made a record on this type--the designs of which he presented to the world. Has not been prominent since. SCHABSKY (Athanasius Ivanovitch). Russian. Builder of the _Outchebny_ type dirigible. SCHIERE, J. Aeronautical engineer. Stephonsonstraat 41, The Hague, Holland. Librarian Dutch Ae. C. SCHÜTTE (Prof. Johann), Jäschkenthal 47b, Danzig-Langfukr, Danzig, Germany. Born 1873. Designer of the _Schütte_ dirigible. SCHWANN (Commander Oliver). British Navy. Navy Air Dept., 1912-13. In 1911, conducted a number of hydro-aeroplane experiments. SCRAGG (Geo. H.), American citizen, 19-21, Great Queen Street, Kingsway, London, W.C. European correspondent of American _Aeronautics_. SELLERS (M.B.) (See U.S. aeroplanes) SELLS (Chas. de Grave), La Colombara, Cornigliano-Ligure, Italy. British. A leading authority on all matters having to do with engineering. Also a writer on these subjects. Authority on matters having to do with aviation in Italy. SHAFFER (Cleve T.) American citizen. West Coast correspondent to _Aeronautics_ (U.S.A.) Writer on aerial subjects generally. SIMON (Rene). August 18th, 1911, tied with Sopwith for the world's Climbing speed at Chicago; 500 metres in 3' 35". SMITH (H. White). British. Secretary to the Bristol Co. SOMMER (Roger) Mouzon, Ardennes, France. Born 1877. Early interested in aviation. In 1908 built a machine of his own design. This was a failure. He then bought one of the first _Farman's_, on which he rapidly achieved success. Towards the end of 1909 he produced the _Sommer_ biplane. SOPWITH (T.) British. Won the Baron de Forest prize on a _Howard Wright_, 1910. Also won many other prizes in England and America. 19th August, 1911, tied with Simon, world's climbing speed--500 metres in 3' 35"--at Chicago. Now a constructor. SPENCER (Stanley). Early British dirigible builder (1902). Died 1913. SPOONER (Stanley), 41 St. Martin's Lane, W.C. Editor of _Flight_. Prominent supporter of aviation. Member of R. Ae. C. Committee. STEIN (Lieut.) German aviator. Killed at Doerlitz, February 6th, 1911. STRINGFELLOW. British. A very early experimenter. In 1868 he evolved a triplane model. SUETER (Capt. R. N.) British. In command of British Navy dirigible section, 1911. Admiralty Air Dept., 1912-13. SURCOUF (Edward Louis), 33 Boulevard Lannes, Paris. Born 1862. Chev. Leg. d'Hon. Secretary Com. Sport Ae. C. F. Sec. Com. Aerienne Mixte. Director of the _Astra_ Societé. Constructor of the majority of French dirigibles. SWANN (Rev. Sydney), The Vicarage, Crosby Ravensworth, Westmoreland, England. First clerical aviator. Ceased. SYKES (Major F. H.) Officer Commandant in Charge of Records, Royal Flying Corps, Military Wing. TABUTEAU. French aviator. Winner of the Michelin Trophy. TADDEOLI. Swiss. First Swiss to obtain an aviator's certificate, which he did on a _Dufaux_, October, 1910. Badly injured at Lausanne, June, 1911, during exhibition flights. 1912, built a hydro-aeroplane. TATIN (Victor), 14 Rue de la Folie-Reynault, Paris. Chev Leg. d'Hon. Born 1843. Commenced heavier than air experiments so long ago as 1879, when he made an aeroplane driven by compressed air. Designed the _Ville de Paris_. Had a good deal to do with the _Bleriot_ in its early days. In 1909 designed the _Clement-Bayard_ monoplane. Associated with Paulhan in 1911. Writes on all aerial subjects. TAYLOR (Vincent P.) Australian subject. Well-known aeronaut, using the _nom de plume_ of Capt. Penfold. In 1912 went in for aeroplaning, using a _Bristol_. TISSANDIER (Gaston). French Pioneer aeronaut. Made an electrically-propelled dirigible in 1881. Born 1843. Died 1899. TISSANDIER (Paul), 17 Avenue Victor Hugo, Paris. Son of Gaston Tissandier. Born 1881. Instructor of aviation. Taught many of the best known aviators. TURNBULL (W. R.) American Engineer. In the year 1906 commenced to experiment with hydro-aeroplanes; and may be regarded as the originator of all experiments in this direction. The French _Gabardine_ of much later date did not differ materially from his early models, while the more recent _Fabre_ and the successful _Curtiss Triad_ embodied similar ideas. TURNER (Charles E.) Authority on aviation matters, special aerial correspondent of the _Observer_, etc. TURNER (Lewis W. F.) British. Chief pilot of the Ewen School, 1912. TWINING (S. Frisco). Cal. U.S.A. Experimenter with flappers, man propelled, from 1910 onward. USBORNE (Lieut. Neville F.), R.N. First British naval officer detailed for aerial work. Was appointed to _Clement-Bayard II_ in 1909, and subsequently to the first Naval Dirigible. 1912, Naval Wing, R.F.C. VANNIMAN (Melvin). Built the gondola of the first _Wellman_ airship, and intimately concerned with _Wellman II_. Also designed a triplane 1908. Designed _Akron_, 1911. Killed 1911. VEDRINES. French. Second in the _Daily Mail_ £10,000 prize, 1911, in a _Morane_. Won Paris-Madrid, 1911. One of the best known aviators. Began life as a mechanic. VIVALDI (_late_ Lieut.) Italian naval officer. Killed in a _M. Farman_, August, 1910. VOISIN (Charles), 34 Quai du Point du Tour, Billancourt (Seine), France. Born 1882. Director of _Voisin Freres_. Flew the _Delagrange I._ in 1906. Induced H. Farman to be interested in aviation. VOISIN (Gabriel). Brother of above. Born 1880. Chev. Leg. d'Hon. Director of _Voisin Freres_. Commenced to study aviation in 1902 with Archdeacon. Experimented with gliders. Founded _Voisin Freres_ in 1903. Designer of the _Voisin_ biplane. Killed 1912 in a motor accident. VUIA. French pioneer, who with a machine somewhat like a _Demoiselle_, flew 6 yards in 1906 and 60 yards in 1907. WALDEN (Dr.). U.S. citizen. Badly hurt, 1910, in a machine of his own design, but not killed as reported. (See U.S. aeroplanes.) WALSH (C.F.) American aviator. Winner of various trophies on a _Curtiss_. WARCHOLOWSKY. Austrian aviator. On October 30th, 1911, made world's record to date by flying 45 minutes with three passengers. WEILLER (Lazare), 36 Rue de la Bienfaisance, Paris. Officer Leg. d'Hon. Head of the syndicate which in 1908 was responsible for Wilbur Wright coming to France. WEISS (José). British subject. Pioneer experimenter in aviation. The starting stage used by him for early glider experiments is still to be seen near Arundel Castle, Sussex. Much of our knowledge as to the distribution of weights is due to him. WELLMAN. An American who hoped to reach the North Pole by dirigible. His first ship came to grief at Spitzbergen. In Oct., he attempted a cross-Atlantic voyage, but failed. (See Vanniman). WEYMANN (C). American. Won the 1911 Gordon Bennett on a _Nieuport_. Average speed, 78 miles per hour. WHEELER (R.F.) British Navy. As naval cadet at the age of 15 he obtained his pilot certificate at the Bristol School. WHITE (Sir George, Bart. LL.D. J.P.) Founder and Chairman of the British and Colonial Aeroplane Co., Ltd. President of the Bristol and West of England Ae. C. WIDMER. Austrian aviator. In October, 1911, made a flight over the Adriatic, Venice to Triest. WILLOWS (E.T.) Cardiff, Wales. British Airship pilot 4. Inventor of the _Willows_ airship. Patentee swivelling propellers. Started a dirigible school, 1913. WISEMAN (Fred T.) American aviator. Flies his own type machine. Has made sensational flights delivering newspapers at farmhouses, April, 1911, also letters. WRIGHT (Howard). See HOWARD WRIGHT. WRIGHTS (the) (Orville and Wilbur), 7 Hawthorn Street, Dayton, Ohio, U.S.A. Chevs. Leg. d'Hon. In 1896 the Brothers Wright began to study aerial flight. In 1900 they were making glides. In 1903 they first fitted a motor, and on December 17th of that year made a power flight of about 250 yards. Reports of this were received with incredulity, and right up to July, 1908, when Wilbur Wright appeared in France, many people still regarded the Wrights as a myth. Wilbur Wright easily beat the French machines in circling, etc. He won the Michelin Cup, being up 2 h. 20 m. 23-1/3 sec. Distance 76-1/2 miles official record. Actual, estimated at 93 miles. The exploits of Wilbur Wright put aviation on quite a new footing. Since 1908 the _Wright_ type has been surpassed by others; but to the Wrights will always belong the credit of having made a decided step in the science. Wilbur died of typhoid, 1911. WYNMALEN (Henri). Dutch. Reached 9,121 feet in a _Farman_ in 1910, and was then compelled to descend because after 8,000 feet blood oozed from his finger nails and lips. Ae.C.F. pilot 208, 27th August, 1910. Has made many famous flights. ZENS (Ernest), 3 Rue la Boétie, Paris. Born 1878. Pioneer aviator. On committee of Ae. C. F. First passenger in an aeroplane (carried by Wilbur Wright, 6th September, 1908). Built a monoplane, 1912. ZEPPELIN (Count). The first Zeppelin dirigible was tried in 1900 on Lake Constance. It made a small speed against a 12-16 m.p.h. wind. It also circled. The experiments exhausted the Count's resources until 1905. Details of this and later _Zeppelins_ will be found on the German dirigible pages in Part A. ~CARBURETTERS.~ ~AUSTRIAN-HUNGARIAN.~ DENES FRIEDMANN, 11 Mitterbergasse, Vienna, XVIII. ~BELGIAN.~ DASSE (G.), 49 Rue David, Verviers FAGARD (J.) & Cie, 7 Rue Bouille, Liege, (_Sthénos_). ~BRITISH.~ BROWN & BARLOW, Ltd., 16 Loveday Street, Birmingham BURGESS (W. H. M.), 40 Glasshouse Street, London, W. (_White & Poppe_). CARBURATION, Ltd., 85 Fleet Street, London, E.C. CLAUDEL-HOBSON, 29 Vauxhall Bridge Rd., London, S.W. DAVIS PARAFFIN CARBURETTER Co., London FENESTRE, CADISCHE & Co., 17 Harp Lane, London, E.C. MOSELEY MOTOR WORKS, Birmingham SCOTT, ROBINSON, 3 Great Winchester St., London, E.C. TRIER & MARTIN, Ltd., Trinity Works, New Church Road, Camberwell, London, S.E. (_T.M._) WAILES (George) & Co., 386-8, Euston Road, London, N.W. (_S.U._) ~WHITE & POPPE, Ltd.~, Lockhurst Lane, Coventry WOODNUTT & Co., St. Helens, I.W. ~FRENCH.~ AMOUDRUZ, 24 Rue d' Armaillé, Paris. (Carburateurs "R.V." et "l' Econome"). ASTER (Société de Construction Mécaniques (L')), 74, Rue de la Victoire, Paris AUFIERE (Ch.), 95 Rue de Flandre, Paris BARIQUAND & MARRE (Société), 127 de Oberkampf, Paris BELLAN ET FRANTZ, 137 Avenue de Villiers, Paris. ("Le Va-Partout.") BOURRIENNE, 18 Impasse Amelot, Paris BREUZIN (Ed.) FILS, 26-28 Rue Morand, Paris BRIEST, 119 Rue de Rennes, Nantes BROUSSET (F.), 5 Rue Leprince, Nogent-sur-Marne. ("Normal" & "Lion"). CAILLETTE ET NARÇON, 29 Rue de la Plaine, Paris CHARRON, Ltd., 7 Rue Ampère, Puteaux CLAUDEL (Henri), 41 Rue des Arts, Levallois-Perret CLERC & QUANTIN, 21 Rue Tandou, Paris COTTIN & DESGOUTTES, Place de Bachut, Lyon EMMEL (A.), 278 Boulevard Raspail, Paris EVENS, NOLO & Cie, 150, Avenue St-Ouen, Paris FILTZ (J.), 13 Avenue du Roule, Neuilly-sur-Seine GAUTREAU Fréres, Dourdan GOUBERT, 15 Rue du Pont, Arles GRIANOLI (Étabs. L.), 26 Boulevard Magenta, Paris GROUVELLE (J.) H. ARGUEMBOURG & Cie, 71 Rue du Moulin-Vert, Paris. ("_G. A._") HARDING (H. J.), 7 _bis_, Rue du Débarcadere, Paris. (_J.A.P._) JANVIER (V.), 44 Rue d'Alésia, Paris. ("_Véji._") JANGEY (P.) et Cie, 26 _bis_, Rue Saint-Didier, Paris JOLY FRÉRES, 244 Rue Marcadet, Paris JULLIAN FRÉRES & HERAULT, Beziers LAURENT FRÉRES, Plandher-Les-Mines LONGUEMARE (F. & G.) FRERES, 12 Rue du Buisson-St-Louis, Paris MARTHA (L.), 24 Rue du Champ-Les-Mines, Paris MENEVEAU & Cie, 15 Rue des Trois-Bornes, Paris MERIOT (L.), 22 _bis_, Rue de' Taillandiers, Paris PANHARD-LEVASSOR (Etablissements), 19 Avenue d'Ivry, Paris PASCAUD, 144 Boulevard Magento, Paris PILAIN (Soc.), 17 Chemin de Monplasir à Grange-Rouge, Lyon POUDEROUX (L.), 9 Rue Waldeck-Rousseau, Paris PROGRESSA (Soc.), 3 Passage Moitrier, Levallois-Perret SCHMITZ (J.) & Cie, 17 Rue Saussier-Leroy, Paris STORR & Cie, 17 Rue Saussier-Leroy, Paris STROMBERG MOTOR DEVICES MANUFACTURING Co., 1253 Michigan Avenue, Chicago, U.S.A. TOLLET & Cie, 7 Rue de la Charité, Lyon VAURS, 38 Rue Brunel, Paris VAUTRIAN (L.), 35 Rue Brunel, Paris. ("_Claudet._") VITU (P.), Villa Aline, Rue des Soupirs, Epinal WAGNER, 7 Galeme de la Madeleine, Paris ZENITH (Soc. du Carburateur)-- 55 Chemin Feuillat, Lyon-Monplasir 2 Rue Denis-Poission, Plancher-les-Mines ~GERMAN.~ DULONG, 11 Lingstrasse, Berlin ESCHER (B.), Sachsische Werkzeug Maschinenfabrik, Chemnitz "IDEAL" METALLWARENFABRIK, Opladen (_Ideal A.G._) NEUE VERGASER GESELLSCHAFT, 63 Urbanstrasse, Berlin ~SWISS.~ WAGNER (Soc. d' Ind., Suisse d'Outillage), Bate ~U.S.A.~ BECKLY RALSDON. 178 Lake Street, Chicago BREEZE CARBURETTER Co., 276 Halsey Street, Newark, N.Y. BUFFALO CARBURATOR Co., 887 Main Street, Buffalo, New York BYRNE, KINGSTONE & Co., Kokomo, Ind. GOLDBERG MOTOR CAR DEVICES MFG. Co., 1253 Michigan Avenue, Chicago HEITGER CARBURETTER Co., 205 West South Street, Indianopolis HOLLEY Bros. Co., 661 Beaubien Street, Detroit, Mich. KALAMAZOO CARBURETTER Co., Kalamazoo, Mich. MARVEL MANUFACTURING Co., 410 S. Meridion Street, Indianopolis MYERS (A. J.), 244 West 49th Street, New York. (_G. & A._) SPEED CHANGING PULLEY Co., 758 Washington St., Indianopolis. (_Speed_). STROMBERG MOTOR DEVICES MANUFACTURING Co., 1253 Michigan Avenue, Chicago, London, D.E. (_T.M._) WESTERN MOTOR Co., Logansport, Ind. WHEELER & SCHEBLER, Indianopolis ~FABRICS FOR AEROPLANES AND DIRIGIBLES.~ ~AUSTRIAN-HUNGARIAN.~ METZELER & Cie, 6 Konigstrasse (Gummihof), Vienna VI. ~BELGIAN.~ DUPT (A. D.), 11 Avenue de Keyser, Antwerp ENGLEBERT FILS & Cie, 29 Rue des Vennes, Liege ~BRITISH.~ ACCORDION BOAT Co., 32 Tufton St., Westminster, London, S.W. "AEROPLATTE." (See Rogers Bros.) AUTOMOBILE & AERIAL SUPPLY Co., Norwich Union Buildings, Piccadilly, London, W. AVON INDIA RUBBER Co., Ltd., Melksham, Wilts BENETFINK & Co., Ltd., Cheapside, London, E.C. BENEY (R.) & Co., 7 Carlisle St., Oxford St., London, W. CLARKE (T. W. K.) & Co., Kingston-on-Thames ~CONTINENTAL TYRE & RUBBER Co., (GREAT BRITAIN) Ltd.~, 102 Clerkenwell Road, London, E.C. DUNLOP RUBBER Co., Ltd., Manor Mills, Aston, Birmingham FRANKENBURG & Sons, Ltd., Salford, Lancashire "HARTS," 21 Liverpool Street, E.C. HUTCHINSON AERO CLOTHS, 70 Basinghall Street, London, E.C. IOCO PROOFING Co., Ltd., 50, Fraser Street, Bridgeton, Glasgow IMPERIAL TYRE & RUBBER Co., Brook St., Holborn, London, W.C. ~JONES (Bros., Ltd.)~, 12 York Street, Manchester. MCLEAN, MCLEAN & Co., 79-1/2 Gracechurch St., London, E.C. NEW MOTOR & GENERAL RUBBER Co., Ltd., 374 Euston Road, London, W.C. NORTH BRITISH RUBBER Co., Ltd.:-- 1 Long Acre, London, W.C. Castle Mills, Edinburgh PEGAMOID (NEW) Ltd., 144 Queen Victoria Street, London, E.C. ROE (A. V.) & Co., Brownsfield Mills, Manchester ~ROGERS (Bros.),~ 1 Mitre Court, Milk Street, London, E.C. ("_Aviator_" _Ramie_), (_Aeroplatte_). SPENCER (C. G.) & Sons, 56a, Highbury Grove, London, N. ~DANISH.~ CONTINENTAL CAOUTOUCHOUC & GUTTA PERCHA Co., 28 Amaliegade, Copenhagen ~DUTCH.~ CONTINENTAL CAOUTOUCHOUC & GUTTA PERCHA Co., 1077 Prinsengracht, Amsterdam ~FRENCH.~ ALBERTI (L.) (_Harburg-Wien_), 12 Rue d'Enghien, Paris ~BARBET-MASSIN~, Popelin & Cie., 5-7 Rue St. Fiacre, Paris ~BESSONNEAU~, 21 Rue Louis Gain, Angers CAOUTCHOUC Manufacture (Soc. du.), 86 Rue Notre Dame-de-Nazareth, Paris CONTINENTAL CAOUTOUCHOUC & GUTTER PERCHA Co., 144 Avenue Malakoff, Paris DEVILLE (J.), 42 Rue des Jeuneurs, Paris FALCONNET-PERODEAND (Étabs.), 4 Place Carnot, Choisy-le-Roi (Seine). GODARD (Louis) (Etabls. Aeronautiques de Paris), 170 Rue Legendre, Paris HUTCHINGSON (Etablts.) 60, Rue Saint-Lazare, Paris METZELER & Cie, 1 Rue Villaret-de-Joyeuse, Paris MICHELIN & Cie, Clermont-Ferrand, Puy de Dôme OPPENHEIMER NEVEU, 28 Rue Bergere, Paris PETER (Louis), 107 Rue de Courcelles, Paris RUSSIAN-AMERICAN INDIA RUBBER Co., 47 Rue St. Ferdinand, Paris SULFIMATE (Service du), 200 Boulevard Victor Hugo, Clichy (Seine). TELEPHONES (Soc. Indle. Des), 25 Rue de Quatre Septembre, Paris TORRILHON (Soc. An. des Anciens Etab. J. B.), Chamaliéres Puy de Dôme ~VALDENAIRE~ (~H.~) Adenet & Cie., 21 Rue des Jeuneurs, Paris ~GERMAN.~ CLOUTH (Franz) (Rheinische Gummiwaarenfabrik, Cologne-Nippes) CONTINENTAL CAOUTOUCHOUC & GUTTA PERCHA Co., 100 Fahrenwalderstrasse, Hamburg MICHELIN & Cie, Frankenalle 4, Frankfort RIEDINGER (August), Augsburg, Bavaria SCHUCKERT & Co. (Elektrizitats A.G.), Nuremburg ~ITALIAN.~ CONTINENTAL CAOUTOUCHOUC & GUTTA PERCHA Co., 36 Via Bersaglio, Milan MICHELIN & Cie:-- 117 Via Livorno, gia via Schina, Turin 14 via Toro, Milan ~RUSSIAN.~ CONTINENTAL CAOUTOUCHOUC & GUTTA PERCHA Co., 11 Boiscbaja Dmitrovka RUSSIAN-AMERICAN INDIA RUBBER Co., Tregolnik, 138, Canal Abovdny, St. Petersburg ~SPANISH.~ CONTINENTAL CAOUTOUCHOUC & GUTTA PERCHA Co., 5 Calle Fernando el Santo, Madrid MICHELIN & Cie, 21-23 Calle Sagasta, Madrid ~SWEDISH.~ CONTINENTAL CAOUTOUCHOUC & GUTTA PERCHA Co., Riddoregatan 15, Stockholm ~SWISS.~ CONTINENTAL CAOUTOUCHOUC & GUTTA PERCHA Co., 9 Lowenstrasse, Zurich ~U.S.A.~ BALDWIN (Captain Thos. S.), Box 78 Madison Square, New York CONOVER (C. E.) & Co. (_Naiad_), 101 Franklin Street, New York CONTINENTAL CAOUTOUCHOUC & GUTTER PERCHA Co, Muskegon, Mich. FRENCH AMERICAN BALLOON Co., 4460 Chouteau Avenue, St. Louis GOODYEAR TIRE & RUBBER Co., Akron, Ohio MICHELIN & Cie, Milltown (N. T.). "NAIAD," 101 Franklin Street, New York STEVENS (Aeronaut Leo), Box 181, Madison Square, New York ~GARMENTS FOR AVIATION.~ ~AUSTRIAN.~ BAUR (R.), 4 Rudolfstrasse, Innsbruck GOLDMAN & SALATSCH, 20 Graben, Vienna I. MAKOVSKY & Co., 9 Baumannstrasse, Vienna ~BELGIAN.~ DEPART (Au), 8 Boulevard Anspach, Brussels GAUSSET (F.), 5 Rue du Jardin Botanique, Liege HOEBER & Cie, 48 Chemin de Hall, Forest-les-Brus REEKIE (A.), 17 Rue Royale, Brussels ~BRITISH.~ AEROPLANE SUPPLY Co., Ltd., 111 Piccadilly, London, W. BAKER & Co., Ltd., 137 Tottenham Court Road, London, W.C. ~BURBERYS~ 30-33 Haymarket, London, S.W. Basingstoke DUNHILL (A.), Ltd., 359 Euston Road, London, N.W. GAMAGE (A. W.), Ltd., 126 Holborn, London, E.C. HARROD'S STORES, Ltd., Brompton Road, London, S.W. JOHNSTON (G.) & Co., 110 Cannon Street, London, E.C. NICOLL (H. J.) & Co., Ltd., 114 Regent Street, London, W. NORTH BRITISH RUBBER Co., Ltd., Castle Mills, Edinburgh PENTON (E.) & Son, 11 Mortimer Street, London, W. PIGGOTT (J.), Ltd., 117 Cheapside, London, E.C. ~ROGERS~ (~Bros.~), 1 Mitre Court, Milk Street, London, E.C. (_Mascot_ vests), (_Aeromac_) SAMUEL (Bros.), Ltd., 65 Ludgate Hill, London, E.C. SMEE (E.), 403 Oxford Street, London, E.C. ~FRENCH.~ ABERDEEN, 1 Rue Auber, Paris ARNOUX, 63 Boulevard Malesherbes, Paris AUDOUARD, 3 Rue du Commandant, Rivière, Paris AUX MARINS, 7 Avenue de la Grande-Armée, Paris BARBAN, 67 Rue Rambuteau, Paris BAZAR de L'Hotel de Ville, 54 Rue de Rivoli, Paris BELLE FERNIERE (La), Rue Saint-Pierre, Caon BELLE JARDINIERE (La), 2 Rue du Pont-Neuf, Paris BERNARD, 153 Rue du Faubourg, Saint-Honoré, Paris BINET (E.), 6 Boulevard Diderot, Paris BLUET, 154 Boulevard Haussmann, Paris BOILLAU (M.), 5 Rue d'Tory, Lyon BOINET (G.) & Cie, Saint-Quentin BON MARCHE (Le), Rue de Sèvres, Paris BONNET (G.), 4 Rue de la Bastille, Paris BONNIOL, 10 Rue Turbigo, Paris BOROWSKY, 32 Rue d'Argout, Paris BOURSIN, 61 Rue la Boéthe, Paris BRUNSCHWIG (Ch.), 39 Rue des Bourdounais, Paris BURBERYS, 10 Boulevard Malesherbes, Paris BUSSEY (Geo. C.) & Cie, 25 Rue Tronchet, Paris BUSVINE & Cie, 4 Rue Marbeuf, Paris CAOUTOUCHOUC MANUFACTURE (Société du), 86 Rue Notre Dame de-Nazareth, Paris CARNAVAL de VENISE (Au), 5 Boulevard de la Madeleine, Paris CHAMANSKI & BLOCH, 6 Place des Victoires, Paris CHOCQUENET (V.), 31 Rue des Jeûneurs, Paris CHOTIN (G.), 34 Rue des Archives, Paris CIRET (F.) & Cie, 140 Rue Rivoli, Paris COOK & Cie, 23 Rue Auber, Paris CRABETTE, 54 Faubourg Saint-Honoré, Paris DAMERVAL (A.), 9 Rue Réamur, Paris DAROLES-VINCENT, 22 Rue de Faubourg-du-Temple, Paris DAY, 162 Rue du Faubourg-Saint-Martin, Paris DEITZ (E.), 56 Rue d'Aboukir, Paris DENIAU & Cie, 86 _bis_, Rue de Rome, Paris DEWACHTER, 53 Boulevard Voltaire, Paris DUGAS, Freres, 10 Boulevard Sébastopol, Paris DUROT & LERY, 25 Rue des Trois-Cailloux, Amiens DUBESSY (J.), Villefranche DUBREUIL & PARMENTIER, 34 Rue Montorqueil, Paris EGGER & Cie, 2 Rue de la Vrillière, Paris ESDERS (Maison Henri), 115 Rue Montmartre, Paris FASHIONABLE HOUSE, 16 Boulevard Montmartre, Paris FELDSTEIN, 91 Rue des Marais, Paris FRAENKEL (H.), 28 Rue du Quartre-Septembre, Paris GALERIES LAFAYETTE, 40 Boulevard Haussmann, Paris GRANDE MAISON (A La), 7 Rue Croix-des-Petits-Champs, Paris HALIMBOURG-AKAR (Etablissements), 1 Places des Victoires, Paris HENRY-TREILLE, Marcigny HIGH-LIFE, 112 Rue de Richelieu, Paris HUTCHINSON (Etablissements), 60 Rue Saint-Lazare, Paris KRIEGCK & Co., 23 Rue Royale, Paris LACHASSAGNE (E.), Saint-Etienne LAMBLIN (A.), 15 Rue Tiquetonne, Paris LAMARTINE, 24 Rue des Bons-Enfants, Paris LECONGE & WILLMANN, 2 Rue du Renard, Paris LEON, 21 Rue Daunou, Paris LOUVRE (Grande Magazines du), 164 Rue de Rivoli, Paris LYON (Grand Bazaar de), 31 Rue de la République, Lyon MAGNANT & Cie, 117 Rue Réaumur MAGNE (A.), Moulins, France MANBY, _les_ 19 Rue Auber, Paris MARCHAL (M.), 30 Rue le Peletier, Paris MARECHAL (A.), Nevers MAX-AUSPITZ, 374 Rue Saint-Honoré, Paris MICHEL JACKSON (A.), 92 Rue Richelieu, Paris MICHEL JACKSON (E.), Halluin MENAGERE (À la), 20 Boulevard Bonne-Nouvelle, Paris METTEZ (Maison), 5 Place de l'Hotel de Ville, Paris MOLAY (Jacques), 181 Rue du Temple, Paris MATHAN (G.), 27 Rue Saint-Sabin, Paris NICOLLE, 29 Rue Tronchet, Paris OLD ENGLAND-- 12 Boulevard des Capucines, Paris 114 Via Nazionale, Milan, Italy OLIVIERI & Co., 101 Rue Claude-Decaen, Paris PAGUIN (J.) BERTHOLLE & Cie, 43 Boulevard des Capucines, Paris PARIS-TAILLEUR, 3 Rue du Louvre, Paris PAYEN (Maison G.), 7 Rue de la République, Lyon PETIT MATELOT (Au), 41 quai d'Anjou, Paris PFEIFFR-BRUNET, 17 Rue de l'Ancienne-Comedie, Paris PRINTEMPS (Magasius du), 70 Boulevard Haussmann, Paris RAGEUNEAU, 25 Avenue de la Grande-Armée RÉAUMUR (A.), 82 Rue Réaumur, Paris REVILLON, Freres, 77 Rue de Rivoli, Paris RIBBY, 16 Boulevard Poissonière, Paris RICOUR, 26 Rue du Bouloi, Paris RODDY, 2 Boulevard des Italiens, Paris ROFFY, 2 bis, Rue du Bouloi, Paris ROUSSEAU, 61 Passage du Havre, Paris ROYAL TAYLOR, 41 Avenue de Wagram, Paris RUSSIAN AMERICAN INDIA RUBBER Co., 47 Rue Saint Ferdinand, Paris SAINT, Freres, 34 Rue du Louvre, Paris SAMARITAINE, Rue du Pont-Neuf, Paris SEYNOHA (F.), 249 Rue Saint-Honoré, Paris "SIEG," 19 Avenue de la Grande-Armée, Paris SORIN & MARZETTIER, 2 Rue Haudaudine, Nantes, Paris SPORT (The), 17 Boulevard Montmartre, Paris STEINMETZ, Freres, 16 Rue Cambronne, Paris STROM (D. SCHNEIDER & Cie)-- 16 Rue de la Chaussee-d'Antin, Paris 33 Avenue de la Gare, Nice TELEPHONE (Société Industrielle des), 25 Rue du Quartre Septembre, Paris THIERY & SIGRAND, 18 Boulevard Sébastopol, Paris TORRILHON (J. B.), Chamalieres TROIS-QUARTIERS (Aux), 17 Boulevard de la Madeleine, Paris TUNMER (A.) & Co., 27 Rue du Quartre-Septembre, Paris VELOCE-CLUB (Au), 21 Avenue de la Grande-Armée, Paris VINCENE, 148 Rue du Temple, Paris VOLLANT (A.), 34 Boulevard Sébastopol, Paris WEST END TAILORS, 10 Rue Auber, Paris WILLIAMS & Cie, 1 Rue Caumartin, Paris ~GERMAN.~ ANWANDER (A.), 22 Sonnenstrasse, Munich HERTZOG (R.), 15 Breiterstrasse, Berlin ~ITALIAN.~ MARTINY (Manufacture), 5 Via Pietro Micca, Turin SANGUINETTI (Frat), 8 Corso Vittorie Emanuele, Milan ~SPANISH~ SANCHA (M.), 12 Calle de la Cruz, Madrid ~SWISS.~ GEISTDORFER & Co., 4 Paradeplatz, Zurich ~U.S.A.~ SCANDINAVIAN FUR & LEATHER Co., 16 West 33rd Street, New York ~HANGAR AND SHED BUILDERS.~ ~BRITISH.~ AEROPLANE SUPPLY Co., Ltd., 111 Piccadilly, London, W. HARBROW (W.), South Bermondsey Station, London, S.E. HARRISON, SMITH Buildings, Ltd., Vauxhall Works, Dollinan Street, Birmingham. HUMPHREYS Ltd., Knightsbridge, London, W. MORTON, FRANCIS & Co., Ltd., Hamilton Ironworks, Garston, Liverpool. ~PIGGOTT, Bros. & Co., Ltd.~, 220, 222, 224, Bishopsgate, London, E.C. SMITH (F.) & Co., Carpenters Road, Stratford, London, E. WIRE-WOVE ROOFING Co. & PORTABLE BUILDINGS Co., 108 Queen Victoria St., London, E.C. ~FRENCH.~ ~BESSONNEAU~-- 29 Rue du Louvre, Paris 21 Rue Louis Gain, Angers COMPAGNIE AERIENNE, 63, Avenue des Champs, Elysees, Paris CONSTRUCTIONS DEMONTABLES (Compagnie des), 54 Rue Lafayette, Paris CONSTRUCTIONS ECONOMIQUES (Société de), 11 Avenue de l'Opera, Paris DUBOIS et Cie, 7 Rue Saint-Amand, Paris LAPEYRERE (L.), 44 Rue de l'Eglise, Paris OFFICE d'AVIATION, 3 Avenue de l'Opera, Paris RUBEROID (Societe du), 82 Boulevard Beaumarchais, Paris SAINTE-BEUVE (A.), 196 Quai Jemmapes, Paris ~GERMAN.~ MULLER (A.), 27 Fritcherstrasse, Berlin-Charlottenburg ~HYDROGEN SUPPLIES.~ ~BRITISH.~ BRITISH HYDROGEN Co. (Lane's System), 49-50 Parliament Street, London, S.W. BRITISH OXYGEN Co., Ltd.:-- Elverton St., Westminster, London, S.W. Saltley Works, Birmingham Great Marlborough St., Manchester Boyd St., Newcastle-on-Tyne Rosehill Works, Polmadis, Glasgow ~KNOWLES' OXYGEN Co., Ltd.~, Wolverhampton. WOLF (J.), 15 Seething Lane, London, E.C. ~FRENCH.~ ELECTROLYSE FRANCAISE (L'), 4 Rue des Ecluses, Saint Martin, Paris HYDROGÈNE pour l'Aerostation et l'Industrie (Soc. Francaise de l') (Lane's System), Boulevard Sénart, St. Cloud (Seine et Soise). HYDROXGENE PUR (L') 22 Rue de Douai, Paris Marais de Lomme, Lille (Nord) OXYDRIQUE FRANCAISE (L'), 2 Rue Nouvelle, Paris ~INSURANCE (AVIATION).~ ~BELGIAN.~ MONET (Alfred), 3 Avenue de Cortambert, Bruxelles, Belgium ~BRITISH.~ AEROPLANE SUPPLY Co., Ltd., 111 Piccadilly, London, W. ~BRAY, GIBB & Co., Ltd.~, 14 Sherborne Lane, King William Street, London, E.C. ~CAR & GENERAL INSURANCE CORPORATION, Ltd.~, 1 Queen Victoria Street, London, E.C. DOLAMORE (W. T.), AVIATION INSURANCE BROKER, 199 Piccadilly, W. FORBES (M. W.) & Co., 15 Queen Street, London, E.C. GLASGOW ASSURANCE CORPORATION, Ltd., 10 Queen Street, Cheapside, London, E.C. GOLD (Guy), 1 Cornhill, London, E.C. KINLOCH (D. A.), 13 Leadenhall Street, London, E.C. PLANCHE, HEARN & Co., 12 Newgate Street, London, E.C. WHITE CROSS INSURANCE ASSOC., 1 Cornhill, London, E.C. ~FRENCH.~ ASSURANCE SPECIALES d'AUTOMOBILES (Les) 20 Rue Taitbout (Seine), Paris BANDU DE CHANTPIE (Ch.), 8 Rue Blanche, Paris (Seine) CAPRON & HAREL, 10 Rue Viollet-le-Duc, Paris CASANIVA ET GRIBAUMONT, 50 Boulevard Maesherbes, Paris CAUBERT ET GARNIA (E.), 5 Rue Moreau, Paris FASTINGER (L.), 8 Rue du Sentier, Paris HANCIAN (G.), Omnium des Assurance Terrestries, 59 Rue de Chateaudun HURET (G.), 56 Rue d'Amsterdam, Paris LAURIERS (Des) et DUMONT, 43 Rue Lafitte, Paris LAW-CAR, 42 Rue Pergotese, Paris LE CHARTIR ET DARDONVILLE, 12 Avenue Moatespan, Paris LEFEVRE (P.), 7 Rue Villaret-de-Joyeuse, Paris LLOYD (Continental), 17 Rue Druout, Paris MULLER & DESPIERRES (G.), 26 Rue Etienne-Marcel, France NICOLLEAU (Auguste), 36 Rue de la Chapelle, Paris PIEFR (G.), 92 Boulevard Richard-Lenoir, Paris STEVENS (Pierre), 26 Rue Bergere, Paris TERRIER (V.), Courtier d'Assurances, 81 Boulevard Sébastopol, Paris TROLLET (H.), 131 Rue de Rome, Paris ~LUBRICANTS.~ ~AUSTRIAN.~ GERSON BOEHN & ROSENTHAL, 20 Donaueschingenstrasse, Vienna XX. ~BELGIAN.~ BENZO-BELGE (la), 11 Boulevard du Régent, Brussels GUELETTE & Cie, Hug. (_Diamond-Running Oil._) ~BRITISH.~ ADAMS BRITISH OIL Co., Ltd., Plough Bridge, Deptford, London, S.E. ~ANGLO-AMERICAN OIL CO., Ltd.~, 22 Billiter Street, London, E.C. ANGLO-BOSPHORUS OIL Co., Ltd., Bristol BOWRING PETROLEUM Co., Ltd., Finsbury Court, London, E.C. BRITISH MONOGRAM OIL Co., Ltd., 177 The Vale, Acton, London, W. BUTTERWORTHS, Ltd., 5 Roscoe Chambers, Liverpool BRITISH PETROLEUM Co., Ltd., 22 Fenchurch Street, London, E.C. CARLESS, CAPEL & LEONARD, Hope Chemical Works, Hackney Wick, London, N.E. COUNTY CHEMICAL Co., Ltd., Chemico Works, Bradford Street, Birmingham DICK & Co,, Ltd., 33 Eastcheap, London, E.C. ENGLEBERT & Co., 119 Finsbury Pavement, London, E.C. GRINDLEY & Co., Ltd., Poplar, London, E. KAYE (J.) & Sons, Ltd., 93 High Holborn, London, W.C. MONOVO Co., Mono Works, Stewart's Road, London, S.W. O'BRIEN (H.F.) & Co., Broadheath Oil Works, Manchester PETROLEUM Co., Ltd. (The British), 22 Fenchurch Street, London, E.C. PRICE'S PATENT CANDLE Co., Ltd., Belmont Works, Battersea, London, S.W. ROSE (Sir W. & Co.), 66 Upper Thames Street, London, E.C. STERN-SONNEBORN (A. G.), Royal London House, Finsbury Square, London, E.C. VACUUM OIL Co., Ltd., Caxton House, Westminster, London, S.W. WAKEFIELD (C. C.) & Co., 27 Cannon Street, London, E.C. WHITE, 47 Curtain Road, London, E.C. WILCOX & Co., Ltd., 23 Southwark Street, London, S.E. ~DANISH.~ BEAUVAL (de) Saxlund, 18 Kobmagergade, Copenhagen MEYER & HENCKEL, 60 Kobmagergade, Copenhagen ~FRENCH.~ ACKER, 7 Rue de Bac, Ivry Port (_Auto Victoire._) ANDRÉE (A.) Fils (Societe Anonyme), 8 Rue de la Tour-des-Dames, Paris (_Volgaline & Spidoléine._) AMELIN & RENAUD, 37 Rue Jean-Jacques-Rosseau, Paris AMERICAN OIL Co., 42 Rue Lepeletier, Paris BADIN, 3 Rue de la Mare, Paris BAILLY, 8 Rue de la Michodiére, Paris BANTEGNIE & NEVU, 10 Rue Bateau, Aubervilliers BARBAT (C.), Charenton BAUD, 24 Rue Saint-Roch, Paris BAUDOUIN, 32 Quai Saint-Vincent, Lyon BEDFORD PETROLEUM Co., 67 Boulevard Hausmann, Paris BÉSANCON (E.), Saint-Denis BONIFACE, Frères, Sotteville-L-Rouen BONNEVILLE, ROUILLY & Cie, 27 Rue du Landy, Saint-Denis BORREL & Fils, 58 Rue de Vincennes, Bagnolet BOUCHON & BERTRAND, 17 Rue des Bateliers, Clichy BOUGAULT & Cie, 32 Boulevard Ornano, Paris BOURGEOIS-OUDRY, 18 Rue de la Paix, Vincennes BUISINE & Cie, 35 Rue de Viarmes, Paris BURCKHARDT, 18 Rue Poliveau, Paris (_Auto-Gazoline._) (_Auto-Moto._) CABANNE-NIROUET, 124 Route de Joinville, Champigny-s-Marne CALISCH-ORESTE, 4 Avenue du Cog, Paris CAMUS, 5 _bis_, Rue des Rosiers, Paris CAPET, 61 Rue de la Verrerie, Paris CATHALIFAUD, 120 Boulevard Magenta, Paris CAUÊT, 18 Boulevard Pagel, Saint-Denis CAYEUX, Place de Marche-aux-Herbes, Compiegne CHAILLY, 15 Rue Catulienne, Saint-Denis CHATELET, 30 Rue de Fontenay, Nogent-sur-Marne CHAUDIN & Cie, 132 Faubourg, Saint-Denis, Paris CHEMET, 143 Route de Versailles, Boulogne CHEMIN (A.), 10 Rue Gresset, Amiens (_Lubrifa._) CHICHIGNAUD Au CORNILLON, Saint-Denis CHOUILLOU, 14 Rue Duphot, Paris CLAUDY, 92 Rue Neuve-des-Charpennes, Lyon COLMET & Cie, 70 Rue de Rivoli, Paris COLUMBRIA (Soc. des Prod. & Pub.), 48 Rue de Paris, Saint-Denis COSTADAU, 13 Rue Vendome, Lyon (_Golden Oil._) DANIEL, 4. Rue Villedo, Paris. DÉGREMONT, 21 Rue Gudot-de Mauroi, Paris (_Lion_.) DEGUEANT, Avenue Lagache, Villemonble DELAGE, Quai d'Issy, 37 Issy-les-Moulineaux DELETTREZ. 7 Rue Gide, Levallois-Perret (_G.D._) DELIGNY, 3 Rue de Buisson-Saint, Louis, Paris DESCROIX (P.) & LESAGE, 18 Rue de Normande Asnières DESSALLE, 39 Rue de Paradis, Paris DEUTSCHE (Les Fils de), 50 Rue de Châteaudun, Paris (_A.D._) (_Jupiter._) (_Viscositas._) DION BOUTON (De), 36 Quai National, Puteaux DOMONT, 36 Boulevard Ornano, Paris DROUOT, 172 Faubourg Saint-Martin, Paris FAUCHER, 106 Boulevard Sebastopol, Paris FEIGEL, 14 Rae Barbette, Paris FERRANDON, 164 Avenue de Valmy, Paris FERRON, 59 Boulevard Saint-Denis, Courbevoie FIRBACH, 16 Rue Violet, Paris FLOQUET, 36 Rue de la Haie-Cog., Paris FOURNIER, Frères, 12 Rue Castérès, Clichy FRANCO-RUSSE, Cie, 10 Rue Thimonier, Paris (_Newoléine._) GAGNEPIAN, GONNOT & Cie, 109 Rue Victor-Hugo, Levallois-Perret GALENA OIL Co., Paris GAMARD & LAFLÈCHE, 8 Rue de Thorigny, Paris GARDAIR, 71 Rue de Vaugirard, Paris GAUBERT, 40 Avenue de la Grande-Armée, Paris GÉNÉRAL INDUSTRIELLE (La), 5 Boulevard Voltaire, Paris GEORGIER (A.), 8 Route de Flandre, Bourget GIRARD, 102 Rue du Gazometre, Montreuil (_La Becanine_) GONNOT, 33 Boulevard de la Chapelle, Paris GUILLAUD & VALLAT, 36 Chemin, Saint-Matthieu, Lyon GUILLET-PUSARD, Fils et Cie, 4 Rue Poccard, Levallois-Perret (_Royal Oil._) GUYENOT (J.), 1 Rue du Printemps, Paris (_Motoléine._) HACHARD, 43 Boulevard, Richard-Lenoir, Paris HAMELIN, 65 Rue Rivay, Levallois-Perret HAMELLE, 21 Quai de Valmy, Paris (_Valvoline_). HARMIGNIES, 105 Rue de Paris, Ivry Port HERZEMBERG, 60 Rue Saint-Mandé, Saint-Ouen HUILES & GRAISSES INDUSTRIELLES DE, 18 Rue Gambetta, Nice (_Omnia._) HUILES-VITESSE (Soc. An. des.), Rue des Minimes, Courbevoie INDUSTRIELLE GENERALE (L'), 27 Rue la Bruyère, Paris LACARRIÈRE & GRAVELIN, 11 Rue de Neuilly, Clichy (_La Preferee._) LAGET, 181 Rue Lafayette, Paris LAMPE, Freres, 32 Rue Saint-Lazarre, Paris LA SELVE & BOURGEON, 54 Chemin des Cures, Lyon (_Auto Oil_) LAVOIX, Le Bourget LEBRASSEUR & Cie, 155 Rue de Paris, Saint-Denis LEBRASSEUR, 11 Rue de la Vega, Paris LECLERC (C.), 33 Rue Auger, Pantin LENOIR, 24 Rue Michelet, Pantin LENORMAND, 18 Avenue Saint-Germain, Puteaux LÉONHARD, 14 Rue Coypel, Paris L'HERITIER & Cie, 86 Rue de Paris, Saint-Denis LILLE & BONNIÈRES, 10 Rue des Pyramides, Paris LUBIN, 47 Rue du Liégat, Ivry-Port LUBRICATING Oil Co., Route de Sartrouville, Pecg. LYNDALI & Cie, 80 Rue Taitbout, Paris MACKAY, 2 Cité Trévise, Paris MAILLET, 9 Rue Alfred Condre, Abbeville MALICET & BLIN, 103 Avenue de la Republique, Aubervilliers (_Mab._) MANÇEAU, 60 Rue de Flanders, Pantin MARÉCHAL, 75 Avenue du Chemin-de-Fer, Le Vestinet MARTIN (V.), 50 Boulevard de Strasbourg, Paris MARVILLE & Cie, Rueil MAUPRÉ, 112 Rue de la Chapelle, Paris MICHEL, 15 Rue Ferragus, Aubervilliers MORIN, 48 Rue de l'Aqueduc, Paris NANTERRE, 18 Rue Gambetta, Nice (_Omnia._) NASSOY & RIBAUD, 78 Rue Charles-Nodier, Pantin (_Colzarine_) NICKMILDER, 82 Rue Daquerre, Paris NOBLET, 1 Rue Pastuer, Ivry-Port NORTZ, 29 Boulevard Sébastopol, Paris OLEO, 30 Rue Perrier, Levallois-Perret (_Oleomoto_) OLEONNAPHTES (Societé Anoyme), 164 Avenue de Paris, Saint-Denis OLÉONNAPHTES ÉMULSIONNES (Societé Anonyme), 3 Avenue Victor-Hugo ORANGE & Cie, 432 Avenue de Paris, Saint-Denis PELON, 76 Avenue de la Republique, Paris PENNSYLVANIA OIL Co., 39 Rue Sainte-Cécile, Marseilles PETROLES OIL Co., 2 Rue Fongate, Marseilles (_Onctua._) PEUGEOT, Freres, 71 Avenue de la Grande-Armée, Paris Valentigney PIETRATERRA (A.), 10 Rue des Augustins, Argenteuil POURCHEIROUX, 41 Rue Saint-Ferdinand, Paris POULET & TAYART, 108 Avenue de la Republique, Aubervilliers PRADERE & Cie, 16 Rue du 14-Juillet, Pre-Saint-Gervais (_Virginia_) QUERVEL, 35 Rue du Port, Aubervilliers (_Kervoline_) RASTIT (H.), 38 Rue Bicolas, Marseilles RECORD, 27 Quai Gailleton, Lyon REGNIER, Fils & RODDE, 11 Rue Etienne-Dolet, Paris RENAUD-LEVEQUE & Cie, 37 Rue Jean-Jacques-Rosseau, Paris RENAULT (V.), 145 Avenue, Parmentier, Paris REVAUX, 63 Boulevard Thiers, Amiens RICBOURG, 19 Quai aux, Fleurs, Paris RINCK, Fils, 66 Rue de Rivoli, Paris ROBERT, 25 Rue Drouot, Paris RONDEL, 101 Rue Marceau, Montreuil RONDEL (Ch.), 57 Rue de Saint-Mandé, Montreuil SAUTET, Freres, 99 Route d'Orléans, Montrouge SIMONET (L.), 45 Rue Gambetta, Nancy SIMON-ROCHE, 17 bis, Avenue du Mans, Tours (_Auto Sims_) SIVAN, 8 Place de l'Evêsché Marques, Fréjus (_Record, Aeroline, Motord_) STANDARD OIL Works, 69 Rue d'Hauteville, Paris STORACE (B.), 15 Rue de Paris, Nice SYLVESTER (E.), 6 Rue Nationale, Rouen (_W.S._) TESSE, 15 Rue de Surène, Paris TORRE & Cie, 112 bis, Rue de Paris, Vincennes TOURNEL, 18 Avenue d'Italie, Paris TRABET (L.), 1 Rue Amelot, Paris (_Trabeoline_) VACUUM OIL Co., Ltd., 34 Rue de Louvre, Paris VILLENEUVE (A.), 1 Boulevard Saint-Jacques, Paris WALLACH & Cie, 60 Avenue de la Republique, Aubervilliers WALLET, 12 Rue Rennequin, Paris WILSNER (G.), 29 Rue de Neuilly, Clichy ZEMMER, 91 Rue Petit, Paris ~GERMAN.~ DEPAUW & Cie, 6 Rue de la Linère, Brussels DEUTSCHE [OE]LVERKE, 1 Prinz-Louis, Ferdinandstrasse, Berlin PETROLEUM RAFFINERIE, Breme (_Veloscol_) SPILCKE, 94 Chausseestrasse, Berlin STERN-SONNEBORN (A. G.), 21 Ritterstrasse, Berlin S. 42 SÜDDEUTSCHE OELWERKE, Fribourg-en-Brisgau VALVOLINE OIL Co., 7 Hobzbrücke, Hambourg VOGT & Cie, Görlitz (_Vostol_) ~ITALIAN.~ ARNOLDI & Cie, 37 Via Paolo do Cannobio, Milan CECCARELLI, TEDESCHI & Cie, Corso XXII., Marso, 34, Milan (_Teuff_) CORLIÈ RE, 8 Via Santa-Azata, Boulogne FOLTZER (E.), Rivarolo-Lugure, Genes KOCH (O.), 50 Via Abbadesse, Milan MIRAGOLI & PETSATORI, 67 Foro Bonaparte, Milan OLEUM, Galleria Nazionala, Turin PETROLIO, 76 Piazza Cinque Lampade, Genes REINACH & Cie, 90 Via Lario, Milan (_Oleoblitz_) VOLPATO & Cie, 11 Via Santa-Maria-Fulcornia, Milan ~ROUMANIAN.~ TRAJON, Bucharest, Roumania ~RUSSIAN.~ CHABANIAN (R.), Batoum-Bakou KAISER (R.), Baku MALLARD, Caucase, Batoum NOBEL, Freres, St. Petersburg PITOEFF & Cie, Tiflis SCHIBAEFF & Cie, Bakau TER AKOPOFF, 3 Place Isaac, St. Petersburg ~SPANISH.~ FONTAGUD, 6 Fuentes, Madrid OLEON Co., 13 Asalto, Saragossa USERA (De), 47 Legdnitos, Madrid VACUUM OIL Co., 598 Cortes, Barcelona ~SWISS.~ GRISARD (G.), 302 Route de Greuzach, Bâle HALLER, 8 Splugenstrasse, Zurich HEUMANN (A.) & Cie, Winterthur HUILES MINERALES, Route de Frontenex, Geneva LAMBERCIER (J.) & Cie, Geneva LUMINA (S. A.), Geneva-Vollandes MOEBIUS (H.) & Fils, Bâle OMNIA (Maison), Chêne-Bourg, Geneva SCHMID, 133 Murtenstrasse, Berne ~U.S.A.~ DIXON (J.) CRUCIBLE Co., Jersey-City, New York, (_Graphite_) KEYSTONE LUBRICATING Co., Philadelphia WHITE & BAGLEY Co., Worcester (_Oilzum_) ~MAGNETOS.~ ~AUSTRIAN.~ DENES & DRIEDMAN, 11 Mitterbergasse, Vienna XVIII. ERBEN (S.) & ARNOLD FRIEDMANN, 14 Stubenring, Vienna I. ~BELGIAN.~ BOSCH MAGNETOS, 121 Rue de l'Instruction, Brussels PERNSTEIN (Ateliers), 8 Rue Laporte, Liege-Nord ~BRITISH.~ BOSCH MAGNETOS-- 40-42 Newman Street, London, W.C. 28 Store Street, Tottenham Court Road, London, W.C. BRITISH TELLIER Co., 10 Coburg Place, Hyde Park, London, W. ~EISEMANN MAGNETO Co.~, 43 Berners Street, London, W. FULLER (J. C.) & Son, Woodland Works, Wick Lane, Bow, London, E. ~MEA MAGNETO Co.~, Gresse Buildings, Stephen Street, Tottenham Court Road, London, W. NILMELIOR (Société d'Electricité), 36-37 Alfred Place, Tottenham Court Road, London, W.C. RICHES (G. T.) & Co., 19 Store Street, Tottenham Court Road, London, W.C. SIMMS MAGNETO Co., Ltd., Welbeck Works, Kilburn, London, N.W. VAN RADEN & Co., Ltd., Great Heath, Coventry. ~DUTCH.~ BOSCH MAGNETOS, Willem Van Rijm, Keizergracht 181, Amsterdam ~FRENCH.~ BARDON (L.), 61 Boulevard National, Clichy BAUDOT ET PAZ, 22 Avenue de la Grande-Armée, Paris (_Simms._) BOIN, 33 Rue du Four, Paris BOSCH MAGNETOS-- Depôt 295 Avenue de Saxe, Lyon 17 Rue Theophile-Gautier BREGUET (Maison), 19 Rue Didot, Paris DEBEAUVE, 68 Rue de Sevres, Paris (_Vestale_) ~EISEMANN & Co.~, Lavalette & Cie., 175 Avenue le Choisy, Paris EXTRA. (_See_ Giffard.) GIANOLI, 28 Boulevard Magenta, Paris GIBAUD, 309 Rue de Faubourg, Saint-Antoine, Paris GIFFARD, 283 Rue des Pyrénées, Paris (_L'Extra_) GIRARDEAU (A.), 7 Rue Scribe, Paris GUENET. 5 Rue Montmorency, Paris GUILLOU, 41 Rue de Bagneux, Montrouge HENRIQUE, 54 Quai de Courbevois, Courbevois HERDTLE & BRUNEAU, 93 Rue Pelleport, Paris HOMMEN (H.), 38 Rue de Turenne, Saint-Etienne HYDRA (Société de le Magneto), 11 Rue Charcot, Neuilly-sur-Seine ILIYNE-Berline, 8 Rue des Dunes, Paris INVICTA (Société) (Hamille et Cie), 5 Rue Deves, Neuilly-sur-Seine JUSTON & Cie, 62 Rue du Chemin-Vert, Paris ~MEA MAGNETO~, Feld-Dengen, 157 av. Malakoff, Paris MONTBARBON (Société), 147 bis, Rue de Villiers, Neuilly-sur-Seine (_S.A.M._) NIEUPORT (Société Anonyme des Appareils Electriques), 9 Rue de Seine, Suresnes NILMELIOR (Société), 49 Rue Lacordaire, Paris SIMMS MAGNETO Co., Ltd., 12 Rue de Courcelles, Levallois-Perret STUART & STICHTER, 18 Avenue des Ternes, Paris (_Splitdorf_) UNTERBERG & HELME, 166 Rue Lafayette, Paris (_U.H._) ~GERMAN.~ BERGMANN'S INDUSTRIEWERKE, Gaggneau (_G.m.b.H._) BOSCH MAGNETOS, 11 Hopperlaustrasse, Stuggart ~EISEMANN & CO.~, 61 Rosenbergstrasse, Stuttgart FIELDER (W.), Eisenach (_Ruthardt_) HAENDLER (A.), 52 Heidestrasse, Berlin ~MEA~ (_G.m.b.H._), Stuttgart RAPID ACCUMULATOREN & MOTOREN WERKE, 149 Haupstrasse, Schoneberg-Berlin RUTHARDT & Co., 77 Olachstrasse, Stuttgart SCHOELLER (A.), Frankfort TAUNUS ZUNDERFABRIK (_G.m.b.H._), Frankfort UNTERBERG & HELME, Durlach, Baden WECKERLEIN & STOCKER, 7 Wodanstrasse, Nuremberg (_Moris_) ~ITALIAN.~ BOSCH MAGNETOS, 18 Via San Vittore, Milan ~EISEMANN & Co.~, Ditta Secondo Pratti, 32 Carlo-Alberto, Milan LUCINI (Enrico), 3 Via Petrarca, Milan ~SWEDISH.~ BOSCH MAGNETOS, Fritz Egnall, Norra Bantorget 29, Stockholm ~SWISS.~ KESSERLING (F.) & Cie, Schaffhouse KOMET, 95 Brunaustrasse, Zurich ~U.S.A.~ BOSCH MAGNETOS:-- 160 West St., 56th Street, New York. 223 & 225 West 46th Street, New York. 1253 Michigan Avenue, Chicago 357 Van Ness Avenue, San Francisco DAYTON ELECTRIC MANUFACTURING Co., 98 St. Clair Street, Dayton, Ohio DOW MANUFACTURING Co., Braintree FAWN RIVER MFTG. Co., Constantine, M. FISCH (Geo. L.), 1451 Michigan Avenue, Chicago HEINZE ELECTRIC Co., Lowelle, Mass. HOLTZER, CABOT ELECTRIC Co., Boston (_H.C._) K.W. IGNITION Co., 30 Power Avenue, Cleveland, Ohio ~MEA MAGNETOS~, Marburg Bros., Inc., U.S. Rubber Buildings, New York. Also Detroit and Chicago. MOTSINGER DEVICE MFTG. Co., Pendleton, Ind. PITTSFIELD SPARK OIL Co., Dayton REMY ELECTRIC Co., Anderson, Ind. SPLITDORF Co.-- 261-265 Walton Avenue, New York. 138th Street, New York. ~MISCELLANEOUS ACCESSORIES.~ ~BELGIUM.~ WANSON (Maurice), 10 Rue Jean Stas, Brussels ~BRITISH.~ AEROS, Ltd., 139 St. James's Street, Piccadilly, London. AEROPLANE SUPPLY Co., Ltd., 111 Piccadilly, London, W. BRITISH AMERICAN Co., 300-33 Widdrington Road, Coventry BRITANNIA ENGINEERING Co. (1910), Ltd., Britannia Works, Colchester BRITISH EMALLITE Co., Ltd., 30 Regent Street, London, S.W. BRITISH INSULATED & HELSBY CABLES, Ltd., Warrington BRITISH LOW ACCESSORIES Co., Ltd., 15 Great St. Helen's, London, E.C. BONN (J.) & Co., Ltd., 97 New Oxford Street, London, W.C. BOWDEN PATENTS, Ltd., Baldwin Gardens, London, W.C. BROOKS (J.B.) & Co., Ltd., Criterion Works, Birmingham BROWN (Bros.), Ltd., Birmingham BRAMPTON (Bros.), Ltd., Birmingham ~BURBERRYS~, The Haymarket, London, S.W. (_Aviation Garments_) CENTRAL NOVELTY Co., 99 Snow Hill, Birmingham CHATER, LEA, Ltd., 114 Golden Lane, London, E.C. CLARK (T. W. R.) & Co., Crown Works, High Street, Kingston-on-Thames ~COAN~ (~Robt. W.)~, 219 Goswell Road, London, E.C. (_Aluminium Castings._) COWEY ENGINEERING Co., Ltd., 1 Albemarle Street, London, W. CRAMPTON & Co., 73 Queen Victoria Street, London, E.C. ~CROSLEY, LOCKWOOD & SON~, 7 Stationer's Hall Court, London, E.C. (_Publishers_) DING, SAYERS & Co., Elm Gardens, Mitcham, Surrey DOBBIE McINNES, Ltd., Glasgow, N.B. DRESSER & GARLE, Regent House, Regent Street, London, W. ~DRUMMOND BROS., Ltd.~, Ryde's Hill, Guildford ~EISEMANN MAGNETO Co.~, 43 Berners Street, London, W. ESSEX ACCUMULATOR Co., 499 Grove Green Road, Leytonstone, London, N.E. EVANS (Geo.) & Co., 94 Albany Street, Regent's Park, London, N.W. FLATHER (W. T.), Ltd., Standard Steel Works, Sheffield FRASER BEGG & Co., Ilford. FONTEYN & Sons, 76 Newman Street. London, W. FOULIS (Wilfred), Ltd., Sunbury News, Belford Road, Edinburgh GENERAL AVIATION CONTRACTORS, Ltd., 30 Regent Street, London, S.W. ~GEOGRAPHIA DESIGNING & PUBLISHING Co., Ltd.~, 33 Strand, London, E.C. (_Maps, etc._) HAIM (N. S.), 69 Mark Lane, London, E.C. HANDLEY PAGE, Ltd., 72 Victoria Street, London, S.W. HARRIS & SAMUEL, 10 Dean Street, Oxford Street, London, W. ~HASLER TELEGRAPH WORKS~, 26 Victoria Street, London, S.W. (_Indicators_) HELLEKEN, Ltd., 133 Upper Thames Street, London, E.C. HILL (ROWLAND) & Sons, Ltd., Albion Foundry, Coventry HOBSON (H. H.), Ltd., 29 Vauxhall Bridge Road, London, S.W. HORA (E. & H.), Ltd., 36-38, Peckham Road, London, S.E. ~HOYT METAL Co. OF GT. BRITAIN, Ltd.~, 26 Billiter Street, London, E.C. HUNTSMAN (B.), Attercliffe, Sheffield HURLIN (J.) & Son, 191 Cambridge Road, London, E. JENNINGS, GUILDING & Co., 60 Southgate Street, Gloucester ~JONES Bros., Ltd.~, 12 York Street, Manchester (_Fabrics, etc._) KALKER (E.) & Co., Much Park Street, Coventry KEMPSHALL TYRE Co., 1 Trafalgar Buildings, London, W.C. KIRKBY BANKS SCREW Co., Ltd., Meadow Lane, Leeds LAMPLOUGH & Sons, Ltd., Albion Works, Cumberland Park, London, N.W. ~MALLINSON (Wm.) & Sons~, 130-138 Hackney Road, London, N.E. MARSH (Bros.) & Co., Ltd., Ponds Steel Works, Sheffield MARKT & Co., 6 City Road, London, E.C. ~MEA MAGNETO Co.~, Gresse Buildings, Stephen Street, Tottenham Court Road, London, W. MELHUISH (R.), Ltd., 50 Fetter Lane, London, E.C. MELLIN (F.) & Co., Salisbury Road, Kilburn, London M. P. G. Co., 98 Tollington Park, London, N. MOGUL TYRE Co., Ltd., 15 Carlton House, Regent Street, London, W. MOTOR ACCESSORIES Co., 55 Great Marlborough Street, London, W. MOTOR AVIATION Co., Ltd., 628 Martin's Lane, London, W.C. NOBLES & HOARE, Ltd., Cornwall Road, Stamford Street, London, S.E. NORTH BRITISH RUBBER Co., Ltd., Castle Mills, Edinburgh ~OWEN (Joseph) & Sons, Ltd.~, 199a Borough High Street, London, S.E. (_Aeroplane Woods_) PALMER (L. N.), 9a Trevelyan Road, Tooting, London, S.W. PALMER TYRE Co., Ltd., Shaftesbury Avenue, London, W.C. ~PIGGOTT Bros. & Co., Ltd.~, 220, 222, 224, Bishopsgate, London, E.C. POLDI STEEL Works, Napier Street, Sheffield RANDALL (J. H.) & Co., Green Street Works, Paddington Green, London, W. REASON MNFTG. Co., Ltd., Lewes Road, Brighton RENOLD (Hans), Ltd., Progress Works, Brook Street, Manchester ROE (A.V.), Gt. Ancoats Street, Manchester ~ROGERS Bros.~, 33 Aldermanbury, London, E.C. (_Fabrics, etc._) ROLLETT (H.) & Co., "Avia Works," Coldbath Square, Rosebery Avenue, London, E.C. ROSS, COURTNEY & Co., Ltd., Ashbrook Road, Upper Holloway, London, N. RUBERY, OWEN & Co., Darlaston, Staffs. RUTT (A.) 85 Cannon Road, Bromley SCHAFFER & BUDENBERG, Whitworth Street, Manchester SEEBOHM & DUCKSTAHL, Ltd., Dannemora Steel Works, Sheffield SHORT (Bros.), Eastchurch, Sheppey SMITH (F.) & Co., Ltd., Wire Manufacturers, Caledonia Works, Halifax SNOWDEN & Sons, 427 Norwood Road, London, S.E. SPEAR & JACKSON, Ltd., Aetna Works, Sheffield SPIRAL TUBE & COMPONENTS Co., Caledonian Street, King's Cross, London, N. SPENCER MOULTON (G.) & Co., Ltd., 77-9 Cannon Street, London, E.C. STEWART & CLARKE MFTG. Co., 11 Denmark Street, Charing Cross, London, W. ~THORN & HODDLE ACETYLENE Co., Ltd.~, 151 Victoria Street, London, S.W. TIMPERLEY (Chas. B.), 86b Snow Hill, Birmingham TORMO MFTG. Co., 67 Bunhill Row, London, E.C. UNITED MOTOR INDUSTRIES, Ltd., 45-6 Poland Street, London, W. UNIVERSAL AVIATION Co., 166 Piccadilly, London, W. VAN DE RADEN & Co., Ltd., Great Heath, Coventry ~VANDERVELL (C. A.) & Co.~, Warple Way, Acton Vale, London, W. VENESTA, Ltd., 20 Eastcheap, London, E.C. WARWICK WRIGHT, Ltd., 110 High Street, Manchester Square, London, W. WEBSTER & BENNETT, Ltd., Atlas Works, Coventry WEST LONDON SCIENTIFIC APPARATUS Co., Ltd., Premier Place, High Street, Putney, London, W. WHITELEY EXERCISER Ltd., 35-37 Southwark Bridge Road, London, S.E. ~WHITEMAN & MOSS~, 8 Moor Street, Cambridge Circus, London, W.C. ~FRENCH.~ ACIERIES DE FIRMINY, Firminy, Loire BARDOU, CLERGET & Cie, 12 Boulevard Sebastopol, Paris ~BESSONEAU~, 29 Rue du Louvre, Paris BLOT-GARNIER & CHEVALIER, 9 Rue Beudant, Paris BORDE (I.), 99 Boulevard, Haussmann, Paris BOREL et Cie, 11 Chemin de Pré-Gaudry, Paris CARPENTIER (J.), 20 Rue Delamore, Paris CHAPMAN (H.), Rue Laffitte, Paris CACATRE, 35 Boulevard Saint-Jacques, Paris ~DOUTRE (La Ste. An des Appareils d'Aviation)~, 58 Rue Tait bout, Paris DUCOMET, 11 Rue d'Abbeville, Paris GAUDET (A.), 7 Avenue de Montreuille Fontenay-sous-Bois, Seine GIRAUD (Ainé), 49 Rue Greffulhe, Levallois-Perret GODARD (Louis), 170 Rue Legendre, Paris GOMES (A. C.) & Cie, 63 Boulevard Haussmann, Paris GROSSIORD (A.), Saint-Maurice, Seine HANNOYER (F.), 69 Avenue Parmentier, Paris HUE (E.), 63 Rue des Archives, Paris LADIS LEWKOWICZ, Ervauville, Loviet LEFEBVRE & Cie, 76 Avenue de la République, Paris LEVESQUES, Rue des Haudriettes, Paris LUNKEN VALVE Co., 24 Boulevard Voltaire, Paris MAXANT, 38 Rue Belgrand, Paris MAZELLIER ET CARPENTIER, 20 Rue Delambre, Paris PAREME (J.), 203 Rue Lafayette, Paris PELON, 76 Avenue de la République, Paris PELTRET & LAFAGE, 4 Rue des Rigoles, Paris PERE (J.), 46 Boulevard Magenta, Paris POIRELLE (Vve) & DOURDE, 4 Place Thorigny, Paris PROTAIS, 12 Rue Montbrun, Paris RICHARD (J.)-- 25 Rue Melingue, Paris 10 Rue Halevy, Paris ROEBLING'S (J. A.) & Sons Co., Trenton, New Jersey SCHAEFFER & BUDENBERG, 105 Boulevard Richard-Lenoir, Paris SEEBOHM & DIECKSTAHL, 4 Rue Sanite-Ann, Paris SOCIETE GENERALE D'APPAREILS DE CONTROLE, 105 Rue de la Convention, Paris ~VALDENAIRE (H.), ADENET & Cie~, 21, rue des Jeûneurs, Paris (_Fabrics_). ~GERMAN.~ BAMBERG (Carl), Berlin-Friedenau BASSE & SELVE, Altena BUNGE (B.), Oranienstrasse, 20 Berlin, So. 26 DEUTCHEN WAFFEN-V-MUNITIONSFABRIKEN, Dorotheenstrasse 43-41, Berlin N.W. 41 ~EISEMAN MAGNETO Co.~, 61 Rosenbergstrasse, Nuremberg. FUESS (R.), Steglitz HACKENSCHMIDT (Ch.), 7 Kramergasse, Strasbourg ~MEA MAGNETO~, S. Union Werke G.m.b.H. Feurbach-Stuttgart SPINDLER & HOYER, Goettingue ~U.S.A.~ BRETZ (J. S.), & Co., Times Buildings, Byrant BROWN & Co., 1070 Clinton St., Syracuse, New York CALIFORNIA AERO MFTG. & SUPPLY Co., 441-3 Golden Gate Avenue, San Francisco CHURCH AEROPLANE Co., Brooklyn, New York DELTOUR (J.), Inc., 496th Avenue, New York FRASSE (Peter A.) & Co., 408 Commerce Street, Philadelphia PEDERSEN MANUFACTURING Co., 636-644, First Avenue, New York PENNSYLVANIA RUBBER Co., Jeannette, Pa. RUBEL (R. O.), Louisville, Ky. RUDOLPH (W. F.), Broad Street, Pa. SCOTT, Bros., Cadiz, Ohio STUPAR, 9626 Erie Avenue, Chicago WEAVER-EBLING AUTOMOBILE Co., 2230 Broadway 79th Street, New York WITTEMANN (C. & A.), 17-19 Ocean Terrace, Staten, 1st, New York WILLIS (E. J.) & Co., 85 Chambers Street, New York WILSON & SILSBY, Yacht Sailmakers, Rowe's Wharf, Boston, Mass. ~PACKERS AND SHIPPERS.~ ~BRITISH.~ AEROPLANE SUPPLY Co., Ltd., 111 Piccadilly, London, W. CARBURINE. (See Gas Lighting Improvement Co.) DRESSER & GARLE, Regent House, Regent Street, London, W. MOUNT (J. C.) & Co., 101, Grosvenor Road, London, S.W. ~FRENCH.~ BRAVARD, 40 Rue de l'Arbre-Sec Lyon, Rhone GERFAUD (C.), 26 Rue du Chateau-d-Eau, Paris LANGSTAFF, EHRENBERG & POLLACK, 12 Rue d'Enghien, Paris PAYSSE & Cie, 22 Rue Amperé, Paris ~ITALIAN.~ AMBROSSETTI (G.), 32 Via Nizza, Turin ~U.S.A.~ BRINE (B. S.), Transportation Co. ~PATENT AGENTS (Aerial Specialists).~ ~BELGIAN.~ HAMEL (J.), Liege WUNDERLICH & Cie., Brussels. ~BRITISH.~ BREWER & SONS, 35 Chancery Lane, London, W.C. CHATWIN, HERSCHELL & Co., 253 Grays Inn Road, London, W.C. EDWARDS (ARTHUR) & Co., Chancery Lane Station Chambers, Holborn, London, W.C. MARKHAM & FRANCE, Dudley House, Southampton ROGERS (F. M.) & Co., 21 Finsbury Pavement, London, E.C. ROOTS (J. D.) & Co., Thanet House, Temple Bar, London, E.C. ~STANLEY POPPLEWELL & Co.~, 38 Chancery Lane, London, W.C. THOMPSON (W. P.) & Co., 285 High Holborn, London, W.C., and 6 Lord Street, Liverpool WITHERS (J. S.) & SPOONER, 323 High Holborn, London, W.C. ~FRENCH.~ ARMENGAUD, Paris BLETRY (C.), 2 Boulevard de Strasbourg, Paris BRANDON FRÉRES, Paris DUPONT & ELLUIN, 42 Bd. Bonne-Norwelle, Paris JOUVE (Ad), Marseilles MESTRAL & HARLÉ, 21 rue de la Rochefoucault, Paris PICARD, 97 Rue St. Lazare, Paris. WEISMANN & MARX, 90 rue d'Amsterdam, Paris ~GERMAN.~ ANSBERT VERREITER, Berlin W. 57 BEZUGSQUELLEN-AUSKUNFTEI, Berlin. ~ITALIAN.~ BARZANO & ZANARDO, via Bagutta 24, Milan ~SPANISH.~ BOLIBAR (G.), Barcelona. ~U.S.A.~ EVANS (Victor J.) & Co., 724-726, Ninth St. N.W. Washington, D.C. OWEN (Richard B.), Dept. 5, Owen Building, Washington, D.C. PARKER (C. L.), 30 McGill Building, Washington, D.C. ~PETROL.~ ~AUSTRIAN.~ LEDERER (W.) (_Galizche Karpathen Petroleum A.G._), Galicia NAPHTE UNGARISCHE, 33 Vaczi-Korut, Budapest, Hungary RUSSIAN-AMERICAN OIL Co., 42 Zozsef, Budapest VIII., Hungary ~BELGIAN.~ BELGIAN BENZINE Co. (_Motogazolin_), Haren-Nord MOTTAY & PISCART (_Motocarline_), Haren-Nord-lez-Brussels ~BRITISH.~ ~ANGLO-AMERICAN OIL Co., Ltd.~, 36-38 Queen Anne's Gate, Westminster, London, S.W. (_Pratt's_) BOWLEYS & Son, Wellington Works, Battersea, London, S.W. BOWRING PETROLEUM Co., Ltd., 5, Billiter Avenue, E.C. BRITISH PETROLEUM Co., 22 Fenchurch Street, London, E.C. (_Shell_) CARLESS, CAPEL & LEONARD, Hope Chemical Works, Hackney Wick, London, N.E. GAS LIGHTING IMPROVEMENT Co., Ltd. (_Carburine._)-- 7 Bishopsgate Street Without, London, E.C. Royston Castle, Shore Road, Granton, Edinburgh PETROLES DE GROSNYI (Russie) (P.G.R.), 101 Leadenhall Street, London, E.C. ~BRITISH COLONIES, etc.~ WILSON (J.), 119 Rue Common, Montreal, Canada ~DANISH.~ BEAUVAL & SAXLUND, 18 Kobmagergade, Copenhagen MEYER & HENCKEL, 60 Kobmagergade, Copenhagen ~FRENCH.~ DEUTSCH (Les de) (_Moto-Naptha_), 50 Rue de Chateaudun, Paris FANTO (Cie Des Petroles), 74 Rue St. Lazare, Paris FENAILLE & DESPEAUX (_Benzo Moteur_), 11 Rue de Conservatoire, Paris FIRBACK (E.), 16 Rue Violet, Paris GERFAUD (C.), 26 Rue du Chateau-d-Eau, Paris GRAMMONT (Raffineries) (_Lesourd_), Tours GUILLAND & VALLET, 36 Chemin St. Mathieu, Lyon LANGSTAFF, EHRENBERG & POLLACK, 12 Rue d'Enghien, Paris LASSAILLY (L.), 12 Rue d'Oney, Vitry, Seine LILLE, BONNIERES ET COLOMBES (Soc. Anym.) (_Vaporine & Spiritol_), 10 Rue des Pyramides, Paris NAPHTE CASPIEBBE ET DE LA MER NOIRE (Société), 26 Rue Lafitte, Paris PETROLES (Cie Generale des) (_Naphtacycle_), 2 Rue Fongate, Marseilles PETROLES (Cie Industrielle des), 12 Rue Blanc, Paris PETROLES DE BINAGADI BAKOU (Soc. des), 11 Place des Vosges, Paris RAFFINERIE DE PETROLE DU DUNQUERQUE (ENERGIE) (_Touriste_), 24 Rue Joubert, Paris RAFFINERIE DE PETROLE DU NORD, 26 Rue d'Enghien, Paris (_Eoline_). ~ITALIAN.~ ARNOLDIE (G.) & Cie, 37 Via Pavlo da Cannobis, Milan PETROLI D'ITALIA (Soc.) (_Italia_), 12 Via Andegari, Milan PETROLIO (Soc. Ital. Americana), 76 Piazzi Cinque Lampa, Genoa ~ROUMANIAN.~ AQUILA, Franco-Romana, Bucharest ETOILE ROUMAINE, Bucharest ~RUSSIAN.~ KAISER (B.), Baku NANOYAN & Cie, Batum PITOEFF & Cie, Taflis SCHIBAEFF & Cie, Baku TER-AKOPOFF, 3 Place Isaac, St. Petersburg ~SPANISH.~ CATASUS & Co., 1 Colon, Barcelona DESMARIS FRERES, 8 Rue Claire, Madrid FOURCADEY PROVOT, 8 Calle de Fernaflor, Madrid VILELLA, Tarragona ~SWISS.~ HUILES MINERALES (SOCIETE SUISSE POUR LE COMMERCE DE), Route de Frontenex, Geneva ~U.S.A.~ ELLIS & Co., 11 Broadway, New York PETROLEUM OIL TRUST, 27 William Street, New York PURE OIL Co., 11 William Street, New York ~PROPELLERS.~ ~BELGIAN.~ WANSON (Maurice), 10 Rue Jean Spas, Brussels ~BRITISH.~ AVRO. (See Roe (A.V.) & Co.) BENEY (R.) & Co., 7 Carlisle Street, Oxford Street, London, W. ~BLACKBURN~ (~B.~), Balm Road, Leeds ~BRITISH & COLONIAL AEROPLANE Co., Ltd.~, Bristol BROWN Bros., Ltd., 22-34 Great Eastern Street, London, E.C. CLARKE (T. W. K.) & Co., 26 Clarges Street, London, W. DOVER AVIATION Co., Ltd., Dover (_Normale_) GENERAL AVIATION CONTRACTORS Ltd., 30 Regent Street, London, S.W. (_Rapid_) GRAHAME-WHITE (C.) & Co., Ltd., 1 Albemarle Street, Piccadilly, London, W. HANDLEY PAGE, Ltd., 72 Victoria Street, London, S.W. HARRIS & SAMUELS, 10 Dean Street, Oxford Street, London, W. HOLLAND & HOLLAND, 479-483 Oxford Street, London, W. LUDWIG LOEWE & Co., Ltd., 30-32 Farringdon Road, London, E.C. MADISON DYNAMO ELECTRIC Co., Littleover, Derby MACFIE (R.F.) &. Co., Norwich Union Chambers, St. James' Street, London, W. MOTOR ACCESSORIES Co., 55 Great Marlborough Street, London, W. ~PIGGOTT~ (~Bros.~) ~& Co., Ltd.~, 220-222-224 Bishopsgate, London, E.C. ROE (A. V.) & Co., Brownsfield Mills, Manchester SMITH & DOREY (G. H. & W. H.), Ltd., 14a Great Marlborough Street, London, W. SPENCER & SONS (C. G.), 56a, Highbury Grove, London, N. TWINING AEROPLANE Co., 29b Grosvenor Road, Hanwell, London, W. WEBB, PEET & Co., Gloucester W.B.G. (See Wilson, Bros. & Gibson) WILSON (Bros.) & GIBSON, Twickenham (_W. B. G._) WRIGHT (Howard T.) (See Howard Wright) WOOD (T.B.), Littleover Works, Derby ~FRENCH.~ APPAREILS AÉRIENS (Société de Construction D'), 36 Rue du Bois, Levallois-Perret AVIA (Société Générale D'Industrie Aéronautique), 62 Rue de Provence, Paris BAUDOT & PAZ, 22 Avenue de la Grande Armée, Paris BAUJARD (Claude), 309, Faubourg Sainte-Antoine, Paris (_Eola_) BREQUET (Louis), Boulevard Vauban, Douai CHAUVIÈRE (L.), 52 Rue Servan, Paris (_Integrale_) CHERVILLE (M.), 6 Place de l'Odéon, Paris. DOREY (W.H.), 14 Rue Torricelli, Paris DURVILLE (P. N. G.), 38 Rue Jouffroy, Paris. EOLA (_See_ Baugard) ESNAULT-PELTERIE (ETABLISSEMENTS), 149 Rue de Silly, Billancourt (_R.E.P._) GODARD (Louis), 170 Rue Legendre, Paris HELICE (E.T.M.), PARIS INGENIEUR, 17 Rue Cassette, Paris KAPFERER (M.), 2 Avenue de Messine, Paris (_Aero-propulser_). (_A.P._) KOECHLIN (P.), 45 Rue Denfert-Rochereau, Boulogne, S. LABANHIE ET RUTHER, 2 Rue de Seine, Suresnes LETORD & NIEPCE, 15 Rue Paira et 23 Terre-Neuve, Mendon _(Dargent)_ LIORE, 4 _bis_, Rue de Cormeille, Levallois-Perret PANHARD & LEVASSOR (Société Des Anciens Établissements), 19 Avenue D,'Ivry, Paris PASSERAT & RADIQUET (Établissements), 127 Rue Michel-Bigot, Paris _(Progressive)_ PELLIAT (L.), 15 Grand Rue, Asnières (_Rationnelle_) PEYZARET-PARANT, 4 _bis_, Rue Louis-Philippe, Neuilly-sur-Seine, Paris RATMANOFF, 9 Rue Eugène-Eichenberger, Piteaux _(Normale)_ RÉGY FRERES (Les Fils de), 120 et 122 Rue de Javel, Paris R. E. P. (_See_ Esnault-Pelterie) ROSSEL-PEUGOT, Sochaux, près Montbéliard (Doubs) (Société Anonyme des Constructions Aériennes) TELLIER (CHANTIERS), Juvissy THOMAS, 5 Rue des Tanneries, Paris VINOGRADOW (MICHEL), 83 Quai d'Issy, Issy-les-Moutisn VOISIN, 34 Quai du Point-du-Jour, Billancourt VUITTON (LOUIS), 1 Rue Scribe, Paris ~GERMAN.~ ERSTE-DEUTSCHE AUTOMOBIL-FACHSCHULE, Mainz FICHTEL & SACHS, Schweinfurt A.M. PARSEVAL, Bitterfield SCHLOTTER (G.A.), Dresden-A. 16 ~U.S.A.~ AERIAL PROPELLER Co., White Plains, New York AMERICAN PROPELLER Co., Washington, D.C. (_Paragon_) BRAUNER (P.) & Co., 335-339 East 102nd Street, New York CRAFTSMAN PERFECT PROPELLERS, 626 Erie Avenue, Chicago DETROIT AERONAUTIC CONSTRUCTION Co., 306 Holcomb Avenue, Detroit, Michigan DUQUET (L. G), 107 W. 36th Street, New York GREEN (Rurl. H.), 515 Delta Buildings, Los Angeles, Cal. HOLBROOK AERO. SUPPLY Co., Joplin, Mo. REQUA-GIBSON, 225 West 49th Street, New York STUPAR (M.), 9626 Erie Avenue, Chicago WILCOX PROPELLER, Box 181 Madison Square, New York ~RADIATORS.~ ~BELGIAN.~ TOLÉRIE AUTOMOBILE BELGE, 17 Rue des Boyards, Liège ~BRITISH.~ ALBANY MANUFACTURING Co., Willesden Junction, London, N.W. COVENTRY MOTOR FITTING Co., Far Gasford Street, Coventry DOHERTY MOTOR COMPONENTS, Ltd., Coventry LAMPLOUGH & Son, Ltd., Willesden Junction, London, N.W. (_Lamplough-Albany_) MOTOR RADIATOR MANUFACTURING Co.:-- Parkside, Coventry 23 Tanner Street, Bermondsey, London, S.E. SPIRAL TUBE & COMPONENTS Co., Caledonia Street, King's Cross, London, N. ~FRENCH.~ ARQUEMBOURG (Louis), 157 Faubourg, Saint-Denis, Paris BANNEVILLE, 119 Rue Saint-Maur, Paris BARDOU (E.), 150 Rue Victor-Hugo, Levallois-Perret BAUDIER (Ch.), 30-32 Rue Baudin, Levallois-Perret BISIAUX, 11 Rue Petit, Paris BONFILS, 37 Avenue de Saint-Mandé, Paris BRACHTEN ET GALLAY, Bellegarde CHAMPESME, 5 Rue La Vieuville, Paris CHAROY (G.) Et Cie, 5 Boulevard Voltaire, Paris CHAUSSON Frères, 27 Rue Malakoff, Asnieres CHIROL & Cie, 53 Rue de Lorraine, Levallois-Perret CHOUBERSKY (Société Anonyme des Etablissements), 20 Rue Félicien-David, Paris COCHAUX (Emile), Deville DARBILLY (J.), 198 Boulevard Pereire, Paris DESNOYERS Freres, 116 Boulevard Richard-Lenoir, Paris DURAND, GIROUX & Cie, 5 Rue Saint-Marri, Paris ELECTRIC ACETYLENE (L.), 52 Rue Balay, Saint-Etienne ELOY (Lucien), Rue Louis Soyer, Villemonble ENTREPOT METALLURGIGUE (L.), 5 Passage de l'Industrie, Paris ESTABLIE Freres et Louis Establie, 11 Quai de Valmy, Paris FREES (De), 19 Rue de Recroy, Paris FUREST (G.) et Cie, 32 Boulevard Henri-IV., Paris GAY ET BOURGOENS, 53 Rue Louis-Blanc, Lyon GOUDARD MENNESSON, 119 Rue de Montreuil, Paris GRIMMEISEN (Ch. & G.), 5 et 7 Passage Piver, 92 Faubourg du Temple, Paris GRENIER & MERCIER (SOCIETÉ ANONYME DES ETABLISSEMENTS), 8 Avenue de Bouvines, Paris GROUVELLE, ARQUEMBOURG ET Cie, Rue du Moulin-Vert, Paris (_Arécal_) LAEIS & Cie, 86 Rue de Villiers, Levallois-Perret LAMBERT (P.) et Cie-- 109 Rue de Paris, Puteaux 36 Rue Vitruve, Paris LE BRUN ET LECOMTE, 14 Rue Victor-Hugo, Puteaux LIOTARD Freres, 22 Rue de Lorraine, Paris LORTHIOY (E.), 9 Avenue du Clos, St. Maur-les-Fosses MARCHAL (A.), 9 Rue de l'Hotel-de-Ville, Neuilly-sur-Seine MONTBARBON (Société Anonyme), 47 _bis_, Rue de Villiers, Neuilly-sur-Seine (_Loziano_) MONNET & MOYNE, 11 Rue Torricelli, Paris MOREUX (G.) & Cie, 24 Rue Fromont, Lyon (_G.M._) OSSANT Freres, 29 Rue Arago, Puteaux PRINI ET BERTHAUD, 23 Rue Servan, Paris PROUX, Boulevard Pont-Ochard, Poitiers RADIATORS ET RÉFRIGÉRATUERS (Société des), 54 Rue de la Chapelle, Saint-Ouen (_Sans Soudure_) SCHLEY (A.) Et Cie, 204 Rue Saint-Maur (_Loyal_) SERROVAL (De) Et MASSE, 17 Rue David, Lyon TOPOLSKI, 53 Boulevard de Belleville, Paris VIGNEAUX, 5 Rue Bacon, Paris ~ITALIAN.~ ALGOSTINO, BALAGNA, MAGNINO & Cia, 107 Madama Cristina, Turin BONO & Co. (Societa Italiana), 54 Corso Porta, Vittoria, Milan GALIMBERTI, 20 Via Senato, Milan ~SPANISH.~ COROMINAS (Ricardo), 45 Torrente de la Olla, Barcelona ~SWISS.~ HENNEBERG & DEY, à la Jonction, Geneve-Frontenex ~U.S.A.~ AERIAL NAVIGATION Co., of AMERICA, Girard, Kansas (_Call._) EL. ARCO Co., 6 East 31st Street, New York KINSEY MFTG. Co., Dayton, Ohio LIVINGSTONE RADIATOR Co., 6 East 31st Street, New York LONG MFTG. Co., 1430 Michigan Avenue, Chicago MAYO RADIATOR Co., New Haven, Con. McCORD & Co., 1400 and 1440 Old Colony Buildings, Chicago MOTOR COMPONENTS MFTG. Co., 119 E. Walnut Street, Desmoines, Iowa ROME-TURNEY RADIATOR Co., East 31st Street, New York WOLVERINE RADIATOR Co., 124 Sidney Avenue, Detroit, Mich. ~ALPHABETICAL INDEX OF AEROPLANES.~ Abbreviations:--Aust=Austro-Hungarian; Bel=Belgian; Brit.=British; Ger.=German; Ital.=Italian; Jap.=Japanese; Rou.=Roumanian; Rus.=Russian. ~A~ Aeros., Brit., 37 Aerial Exhibition Co., U.S.A., 207 Aerial Yacht Co., U.S.A., 207 Aircraft Factory "B. E." Brit., 37 Aircraft Manufacturing Co., Brit., 37 Albatross, Ger., 131 American Aeroplane Supply House, U.S.A., 207 Antoni, Ital., 172 Ask, Swede, 197 Asteria, Ital., 172 Aviatik, Ger., 133 Avro, Brit., 38 ~B~ Baldwin, U.S.A., 208 Bayard-Clement, 87 Behueghe, Bel., 28 Benoist, U.S.A., 209 Blackburn, Brit., 40 Blair Atholl, Brit., 42 Bleriot, French, 81 Boland, U.S.A., 209 Borel, French, 83 Bracke, A. Bel., 28 Breguet, French, 84 Bristol, Brit., 42 Bronislawski, Rus., 190 Burgess, U.S.A., 210 Burgess-Curtis, U.S.A., 211 Burgess-Wright, U.S.A., 210 ~C~ Calderara, Ital., 173 Caproni, Ital., 174 Caudron, French, 66 Chiribiri, Ital., 174 Christmas, U.S.A., 212 Clement Bayard, French, 87 Cody, Brit., 45 Cooke, U.S.A., 212 Coventry Ordnance Co., Brit., 46 Curtiss, U.S.A., 213 ~D~ Dahlbeck, Swede., 197 D'Artois, French, 88 De Brouckere, Dutch, 28 De la Hault, Bel., 28 Deperdussin, French, 89 Donnet-Leveque, French, 90 Doutre, French, 91 Dorner, Ger., 134 Dunne, Brit., 47 Dux, Rus., 190 ~E~ Etrich, Ger., 134 Etrich, Aust., 18 Euler, Ger., 135 Ewen, Brit., 48 ~F~ Farman, H., French, 92 Farman, M., French, 92 Ferguson, Brit., 48 Fokker, Dutch, 72 Fokker, Ger., 136 Friuli, Ital., 175 ~G~ Gallaudet, U.S.A., 214 Geltouchow, Rus., 190 Goedecker, Ger., 138 Goupy, French, 94 Grade, Ger., 138 Grahame-White, Brit., 49 Grandjean, Swiss., 199 Guidoni, Ital., 175 ~H~ Handley Page, Brit., 50 Hanriot, French, 95 Hansa Taube, Ger., 138 Hanuschke, Ger., 140 Harlan, Ger., 139 Harel, Bel., 28 Howard-Flanders, Brit., 51 ~I~ Internat. Ae. Con. Co., U.S.A., 217 ~J~ Jatho, Ger., 140 Jeannin, Ger., 141 ~K~ Kahnt, Ger., 141 Kennedy, Rus., 190 Kirkham, U.S.A., 215 Kondor, Ger., 142 Kuhlstein, Ger., 142 ~L~ Lake Flying Co., Brit., 53 Loening, U.S.A., 215 Lohner-Daimler, Aust., 19 ~M~ Mars, Ger., 143 Martinsyde, Brit., 53 McCurdy, Canada, 64 Mercep, Aust., 20 Monnier-Harper, Dutch, 72 Morane-Saulnier, French, 96 Moreau, French, 97 Mrozinski, Ger., 143 ~N~ Narahara, Jap., 181 Nieuport, French, 98 Nyrop, Swede, 197 ~O~ Oertz, Ger., 144 Otto, Ger., 144 ~P~ Paulhan-Curtiss, French, 99 Pega-Emich, Ger., 145 Piggott, Brit., 54 Pippart-Noll, Ger., 145 Pischoff, French, 99 ~R~ Radley-England, Brit., 54 Rep, French, 100 Rodjestveisky, Rus., 190 Rumpler, Ger., 146 Ruth-Rohde, Ger., 147 ~S~ Sanchez Besa, French, 101 Savary, French, 102 Schelies, Ger., 147 Schultze, Ger., 148 Sellers, U.S.A., 215 Short, Brit., 54 Sigismund, Ger., 148 Sloan, French, 103 Sloane, U.S.A., 215 Sommer, French, 104 Sopwith, Brit., 57 ~T~ Taddeoli, Swiss, 199 Thomas, U.S.A., 216 Tokogawa, Jap., 181 Train, French, 105 Tubavion, French, 105 ~U~ Union Flugzeugwerke, Ger., 149 ~V~ Van den Burg, Dutch, 72 Vickers, Brit., 58 Vinet, French, 106 Vlaiclu, Rou., 187 Voisin, French, 107 Vreedenburgh, Dutch, 72 ~W~ Warchalowski, Aust., 21 Washington Co., U.S.A., 217 Wetterwald, Swiss, 199 White, Brit., 59 Whitehead, Aust., 21 Williams, Bel., 28 Wittemann, U.S.A., 217 Wright, Ger., 150 Wright, U.S.A., 218-219 ~Z~ Ziegler, Ger., 150 Ziegler, Aust., 21 Zodiac, French, 108 ~ALPHABETICAL INDEX OF DIRIGIBLES.~ Adjutant Reau, French, 109, 113 Adjutant Re Vincennot, French, 109, 113 Astra, French, 111 Astra Torres, British, 60 Astra Torres, French, 115 Astra III, Russian, 193 Astra Transaerien-Ville de Pau-Ville de Lucerne, French, 111 Astra Ville de Pau, French, 111 Ausonia, Italian, 179 Beta, British, 60 Boemcher II, Austrian, 23 Capitaine Ferber, French, 109 Capitan Maréchal, French, 109 Citta di Milano, Italian, 177 Clement Bayard VI. French, 109 Clement Bayard, Russian, 191 Colonel Renard, French, 109, 112 Commandant Coutelle, French, 109 Delta, British, 60 Deutschland, German, 151 Dupuy-de-Lôme, French, 117 Eclaireur Conté, French, 109, 114 Epsilon, British, 60 Ersatz Deutschland, German, 166 Espana, Spanish, 195 Fleurus, French, 109 Forszmann, Russian, 271 Gamma, British, 60 Hausa, German, 167 Italia, Italian, 179 Jastreb, Russian, 191 Kommissiony, Russian, 191 Korting-Wimpassing, Austrian, 24 La Belgique II & III, Belgian, 29, 30 Lebaudy-Juillot 6, Austrian, 23 Lebedj, Russian, 191 Leonardo da Vinci, Italian, 179 Le Temps, French, 109 Liberté, French, 109 Lieut. Chaure, French, 109, 113 L I, German, 151 L II, German, 151 Le Temps, French, 122 Liberte, French, 109 M I, German, 154 M II, German, 154 M III, German, 154 M IV, German, 155 Mannsbarth, Austrian, 24 P I, German, 151 P II _Ersatz_, German, 151 P III, German, 151 P IV, German, 151 P. L I, German, 151 P. L 9, German, 151 P. L XII, German, 151 P. L 10, German, 151 Parseval, Austrian, 25 Parseval, British, 160 Parseval, German, 157, 158, 159, 160, 161 Parseval, Italian, 177 Parseval, Japanese, 182 Ruthenberg II, III, German, 162 Sachsen, German, 151 Schütte-Lanz I & II, German, 163 S. L I, German, 151 S. L II, German, 151 Selle de Beauchamp, French, 109 Spiess, French, 109 Stollwerck, German, 151 Suchard, German, 163 S. I. II, German, 151 Suchard, German, 151 Torres-Quevedo II, Spanish, 195 Transaerienne II, French, 113 Usuelli, Italian, 179 Vanniman, 329 Viktoria Luise, German, 166 Ville de Bruxelles, Belgian, 330 Ville de Lucerne, French, 111 Ville de Paris, French, 110 Willows, British, 60 Yamada, Japanese, 182 Z I, German, 151 Z II, German, 151 Z III, German, 151 Z IV, German, 151 Zeppelin, German, 164, 165, 166 Zodiac III, French, 120 Zodiac XII, French, 125 The Celebrated "Bristol" Aeroplanes. Contractors to the majority of leading governments of the world. Contractors to h. m. war office and admiralty. =LEARN TO FLY= AT THE _"BRISTOL SCHOOLS"_ AT SALISBURY PLAIN and BROOKLANDS. =TUITION= _is given on all the latest type "BRISTOL" MACHINES, including:_ _80 H.P. MILITARY MONOPLANES._ _50 H.P. MILITARY MONOPLANES._ _50 H.P. SIDE-BY-SIDE SCHOOL MONOPLANES._ _TRACTOR BIPLANES & SCHOOL BIPLANES._ SPECIAL FACILITIES AND REDUCED FEES TO SERVICE OFFICERS. WRITE FOR INFORMATION: THE BRITISH & COLONIAL AEROPLANE Co., Ltd., FILTON, BRISTOL, ENG. "EMPYREAN" POLICY _INSURING PILOTS OF AEROPLANES AGAINST_ FIRE & EXPLOSION. ACCIDENTAL DAMAGE. DAMAGE DURING TRANSIT. THIRD PARTY CLAIMS. INJURY TO PILOTS. INJURY TO EMPLOYEES. [Illustration] CAR & GENERAL INSURANCE CORPORATION, LIMITED. HEAD OFFICE: 1, QUEEN VICTORIA STREET (BANK), LONDON, E.C. NET INCOME, £290,000. LIQUID ASSETS nearly £200,000. _BRANCH OFFICES._ ~ABERDEEN~--245, Union Street ~BEDFORD~--17, St. Paul's Square ~BIRMINGHAM~--Prince's Chambers, 6 Corporation Street ~BRADFORD~--Prudential Buildings, Ivegate ~BRIGHTON~--18, Queen's Road ~BRISTOL~--West India House, Bristol Bridge ~CARDIFF~--1, Bank Buildings (Ground Floor), St. Mary St. ~CROYDON~--52, North End ~DUBLIN~--33, Dawson Street ~DUNDEE~--14, Barrack Street ~EALING~--19, The Broadway ~EDINBURGH~--87, Shandwick Place ~EXETER~--28, Gandy Street ~GLASGOW~--163, West George Street ~HANLEY~--P.O. Chambers, Crown Bank ~HULL~--Walton Chambers, 48 Jameson Street ~IPSWICH~--St Mildred's Chambers, Cornhill ~KENT~--137-138, High Street, Bromley ~LEEDS~--Yorkshire Post Chambers, Albion Street ~LEICESTER~--1, Horsefair Street ~LIVERPOOL~--2, South John Street (Lord Street Corner) ~LONDON, N.E.~--124, High Street, Shoreditch ~" MID.~--379, Strand, W.C. ~" S.~--222, Great Dover Street, S.E. ~" S.W.~--222, Great Dover Street, S.E. ~" W.~--1, Albemarle Street, Piccadilly ~MANCHESTER~--1, Princess Street, Albert Square ~NEWCASTLE~--Pearl Buildings, Northumberland Street ~NORTHAMPTON~--Market Square ~NOTTINGHAM~--Westminster Buildings, Theatre Square ~PLYMOUTH~--90, Old Town Street ~READING~--Broadway Buildings, Station Road ~RICHMOND~--26, Hill Street ~SHEFFIELD~--King's Chambers, Angel St. ~SOUTHAMPTON~--Blenheim Chambers, Above Bar (the Junction) _WE ARE THE PIONEERS AND LEADERS IN ALL INSURANCE FACILITIES FOR MOTORISTS._ MORE THAN MONEY INDEMNITY. Our ~35~ Branch Offices in charge of skilled Salaried Official, our Engineering Staff wholly in the service of the Corporation, our expert Claims Staff everywhere, and the fact that we are the Pioneers and Originators of all the Insurance Facilities now enjoyed by Motorists, enable us to offer something more than money indemnity; we can, and do, protect a motorist in a thousand ways, unobtainable elsewhere, by means of our experience and splendid organisation, and yet we only charge ~competitive rates of Premiums~. ALPHABETICAL LIST OF ADVERTISERS. PAGE Anglo-American Oil Co., Ltd. xii Barbet-Massin, Popelin & Cie (_France_) xi Blackburn Aeroplane Co. vii Branger (_France_) xiii Bray, Gibb & Co., Ltd. ix British & Colonial Aeroplane Co., Lt inside front cover Burberrys' vii Car & General Insurance Corporation, Ltd. ii Coan, Robert W. vi Continental Tyre & Rubber Co., (Gt. Britain) Ltd. vii Cox, G.H. & Co., Ltd. vi Crosby Lockwood & Son vi Doutre, Appareils d'Aviation (_France_) v Drummond Bros., Ltd. viii Eisemann Magneto Co. xii _Fighting Ships_ xiv "Geographia," Ltd. vi Hasler Co., The viii Howard-Flanders, L., Ltd. xi Hoyt Metal Company of Great Britain, Ltd. vi Jones Brothers, Ltd. xi Kemp Machine Works (_U.S.A._) xiii Knowles Oxygen Co., Ltd. vii Mallinson, Wm. & Sons, Ltd. ix Martin & Handasyde x Mea Magneto Co., Ltd. xiii Owen, Joseph & Sons, Ltd. xi Piggott Bros. & Co., Ltd. xi Pratt's Motor Spirit xii Rogers Brothers xi & xiv Sampson Low, Marston & Co., Ltd. xiv Sopwith Aviation Co. ix Stanley, Popplewell & Co. vii Thorn & Hoddle Acetylene Co., Ltd. viii Valdenaire, H., Adenet & Cie (_France_). xiii Vandervell, C.A. & Co. viii Vickers, Ltd. xv White & Poppe, Ltd. vii Whiteman & Moss, Ltd. viii Wolseley Tool & Motor Car Co., Ltd. vi CLASSIFIED INDEX OF ADVERTISERS. ~Accessories.~ PAGE Anglo-American Oil Co., Ltd. xii Barbet-Massin, Popelin & Cie (_France_) xi Coan, Robert W. vi Eisemann Magneto Co. xii "Geographia," Ltd. vi Hasler Co., The viii Jones Brothers, Ltd. xi Mallinson, Wm. & Sons, Ltd. ix Mea Magneto Co., Ltd. xiii Owen, Joseph & Sons, Ltd. xi Piggott Brothers & Co., Ltd. xi Pratt's Motor Spirit xii Rogers Brothers xi & xiv Valdenaire, H., Adenet & Cie (_France_) xiii Vandervell, C.A., & Co. viii White & Poppe, Ltd. vii Whiteman & Moss, Ltd. viii ~Aeroplane Builders.~ Blackburn Aeroplane Co. vii British & Colonial Aeroplane Co. Ltd., inside front cover Doutre, Appareils d'Aviation (_France_) v Howard-Flanders, L., Ltd. xi Martin & Handasyde x Sopwith Aviation Co. ix Vickers, Ltd. xv ~Aluminium.~ Coan, Robert W. vi ~Aviation Garments.~ Burberrys' vii ~Bearings.~ Hoyt Metal Co., Ltd. vi ~Castings.~ Coan, Robert W. vi ~Carburettors.~ White & Poppe, Ltd. vii ~Dynamos.~ Eisemann Magneto Co. xii ~Electric Lighting.~ Vandervell, C.A., & Co. viii ~Engines.~ Kemp Machine Works (_U.S.A._) xiii Wolseley Tool & Motor Car Co., Ltd. vi ~Fabrics.~ Barbet-Massin, Poplin & Cie (_France_) xi Continental Tyre & Rubber Co. (Gt. Britain) Ltd. vii Jones Brothers, Ltd. xi Rogers Brothers xi & xiv Valdenaire, H., Adenet & Cie (_France_) xiii ~Flying Schools.~ Blackburn Aeroplane Co. vii British & Colonial Aeroplane Co. Ltd., inside front cover Doutre, Appareils d'Aviation (_France_) v Howard-Flanders, L., Ltd. xi Martin & Handasyde x Sopwith Aviation Co. ix Vickers, Ltd. xv ~Garage.~ Cox, G.H. & Co., Ltd. vi ~Hangar and Shed Builders.~ Piggott Bros. & Co., Ltd. xi ~Hardwoods.~ Mallinson, William & Sons ix Owen, Joseph & Sons, Ltd. xi ~Hydrogen.~ Knowles Oxygen Co. vii ~Indicators.~ Hasler Co., The viii ~Insurance.~ Bray, Gibb & Co., Ltd. ix Car & General Insurance Corporation, Ltd. ii ~Life Saving Vests.~ Rogers Brothers xi & xiv ~Machine Tools.~ Drummond Bros. Ltd. viii ~Magnetos.~ Eisemann Magneto Co. xii Mea Magneto Co., Ltd. xiii ~Maps (specially designed).~ "Geographia," Ltd. vi ~Motor Spirit.~ Anglo-American Oil Co., Ltd. xii Pratt's Motor Spirit xii ~Patent Agents.~ Stanley, Popplewell & Co. vii ~Photographer.~ Branger (_France_) xiii ~Publishers.~ Crosby Lockwood & Son vi "Geographia," Ltd. vi Sampson Low, Marston & Co., Ltd. xiv ~Stabilisateurs.~ Doutre, Appareils d'Aviation v ~Tuition.~ Blackburn Aeroplane Co. vii British & Colonial Aeroplane Co. Ltd., inside front cover Doutre, Appareils d'Aviation (_France_) v Howard-Flanders, L., Ltd. xi Martin & Handasyde x Sopwith Aviation Co. ix Vickers, Ltd. xv ~Welding.~ Thorn & Hoddle Acetylene Co., Ltd. viii [Illustration: _ECOLE MILITAIRE DE CORBEAULIEU._] [Illustration: _STABILISATEUR DOUTRE._] [Illustration: _AÉROPLANE DOUTRE._] _BIPLANS TRIPLACES_ _les mieux construits, les plus surs et automatiquement stabilisés_ _ECOLE CIVILE ET MILITAIRE_ _Aerodrome de Corbeaulieu près Compiègne France._ _S^{té} des APPAREILS d'AVIATION DOUTRE_ _Fournisseurs des armées Françaises et Etrangires._ _LE SUEL_ _STABILISATEUR_ _AUTOMATIQUE PESANT_ _TOUT ÉQUIPÉ DOUZE À QUINZE_ _KILOGS ET AYANT FAIT SES PREUVES_ _PAR PLUS DE DEUX MILLE VOLS SANS ACCIDENT._ _APPLICABLE À TOUS LES AÉROPLANES ET HYDROAÉROPLANES._ _SÉCURITÉ ABSOLUE, VOL PAR TOUS LES TEMPS._ CATALOGUE FRANCO SUR DEMANDE - FETTERER DIRECTEUR GÉNÉRAL. 58 RUE TAITBOUT. PARIS. TÉLÉPH CENTRAL 37-53. Aluminium Castings FOR MOTORS OF EVERY DESCRIPTION, 2 H.P. to 200 H.P. CAST ALUMINIUM MOTOR NUMBER PLATES (Regulation Size). LA.1742 R·5077 BRIGHT POLISHED FIGURES AND BEADED EDGES, WITH DEAD BLACK BACK GROUND. Send for particulars of my new COMBINED TOURING PLATE (Reg.) Telegrams: "KRANKASES," ISLING, LONDON. Telephones: 3846 City. 4879 Central. Coan Casts Clean Crank Cases ON ADMIRALTY AND WAR OFFICE LISTS. ROBERT W. COAN, _THE ALUMINIUM FOUNDRY,_ 219, GOSWELL ROAD, E.C. [Illustration: THE SOCIETY OF MOTOR MANUFACTURERS & TRADERS] WOLSELEY LIGHT Aero Motors 60 H.P. and 120 H.P. (water cooled). 60-80 H.P. (combined air and water cooled.) Catalogue free on application to THE WOLSELEY TOOL AND MOTOR CAR Co., Ltd. Proprietors: VICKERS, Limited, ADDERLEY PARK, BIRMINGHAM. "Geographia," Ltd. 33, STRAND, W.C. SPECIALISTS IN AVIATION ACCESSORIES. Alexander Cross - ANTI-DRIFT COMPASS " " - BEARING FINDER " " - MAP CASE "GEOGRAPHIA" BAROGRAPHS and HEIGHT RECORDERS. MAPS FOR AVIATORS DRAWN TO ORDER. AVIATION MAPS FROM AERODROME TO AERODROME ALWAYS IN STOCK. ASK FOR ILLUSTRATED PRICE LIST. Telegraphic Address:--"Geografo, London." Telephone 4965 City. =G. H. Cox & Co., Ltd.= CASTLE ROAD, SOUTHSEA, :: HANTS. :: LARGEST GARAGE IN :: THE SOUTH OF ENGLAND. [Illustration: HOYT METAL CO. LONDON THE FORMER UNREGISTERABLE BRAND ICE - INTERNAL COMBUSTION ENGINE REG. LINING METAL HOYT METAL CO. COPPER HARDENED. HAS BEEN ABANDONED TO IMITATORS.] TRIAL INGOTS CHEERFULLY SUPPLIED. RECENT||RECORDS: A.B.C. (AERO) 45 H.P. ENGINE--8 HRS. 23 MIN. TALBOT 25 H.P. CAR--103-3/4 MILES IN 1 HOUR. PEUGEOT 30 H.P. CAR--106-1/5 MILES IN 1 HOUR. DIE-CAST BEARINGS FOR REPETITION WORK. THE HOYT METAL CO. OF GREAT BRITAIN, LIMITED. 26, BILLITER STREET, LONDON, E.C. TWO IMPORTANT BOOKS ON AVIATION. 180 Pages, with Diagrams. Crown 8vo. ~3s. 6d.~ net. THE AVIATION POCKET BOOK for 1913. Containing amongst other valuable information, the Theory and Design of the Aeroplane, Structural Material, Examples of Actual Machines, &c., &c. By R. BORLASE MATTHEWS, A.M.I.C.E., M.I.E.E., _Member of the Royal Aero Club_. CONTENTS: Air Pressure and Resistance--Aeroplane Theory and Design--Structural Materials--Engines--Examples of Actual Machines--Piloting and Aerial Navigation--Meteorological Data--Military Information and Signalling--Aero Clubs and Societies--Glossary of Terms used in Flying. Extract from Reviews: "_... a large amount of information is included in these various chapters and the diagrams and curves used to illustrate the texture some of the plainest and most easily understood that we have ever seen in a book of this class ... generally speaking the data given would appear just such as are not contained in other books of reference._"--Engineer. "_The Book is one which we are sure many will find useful and convenient._"--Engineering. Popular Edition. 294 pages. 95 Illustrations and Dimensioned Drawings. Demy 8vo. cloth 5s. net. THE ART OF AVIATION. A Handbook upon Aeroplanes and their Engines, with Notes upon Propellers. By R. W. A. BREWER, A.M.I.C.E., M.I.M.E., &c. "_... Those who for the present have no intention of trusting themselves on the wings of an aeroplane will still find the book of value; those who already are engrossed in the study of aeronautics cannot afford to ignore it._"--Engineering. _Complete List, Post Free, from_ London: CROSBY LOCKWOOD & SON, 7, Stationer's Hall Court, E.C., & 5, Broadway, Westminster, S.W. _Dependability_ In carburettors there is no greater essential than dependability, and-- The dependability of the White & Poppe is such as ensures a never-failing and invariable efficiency. That's why it is the favourite with many of the leading Airmen of the day. Our Booklet describes it fully, and we shall be delighted to send you copy. WHITE & POPPE, LTD., COVENTRY, ENG. _White & Poppe Carburettor_ BURBERRY AEROPLANE EQUIPMENT. ~DESIGNED BY EXPERTS~ is workmanlike both in design and detail, and permits absolute freedom for arms and limbs. Made in wind and weatherproof Gabardine, lined throughout with Camel Fleece or Quilted Eiderdown, it maintains phenomenal warmth under the severest conditions. ~BURBERRY GABARDINE~ is remarkably airylight, yet affords perfect protection against wind, cold or rain, and is so strong that broken stays cannot penetrate its dense texture. ~Mr. C. Grahame-White~:--"_I take this opportunity of thanking you for the suit I wore on my memorable flight and feel I cannot recommend the material too highly where warmth and comfort are required._" BURBERRYS Haymarket, S.W., LONDON; Boulevard Malesherbes, PARIS; Basingstoke and appointed Agents in Provincial Towns. [Illustration: Burberry Aeroplane Outfit.] SPECIFY "Continental" RUBBER-PROOFED MATERIAL. IT COMBINES MAXIMUM RESISTANCE WITH ENORMOUS STRENGTH, AND IS UNAFFECTED BY ATMOSPHERIC CONDITIONS. WRITE FOR LIST, FREE ON REQUEST. Continental Tyre & Rubber Co. (Gt. Britain) Ld. 3/4, THURLOE PLACE, LONDON, S.W. BLACKBURN AEROPLANES, HYDROPLANES AND PROPELLERS. Write for Prices and Particulars to THE BLACKBURN AEROPLANE Co., BALM RD., LEEDS. 'Phone, 2822 Central. Telegrams: "PROPELLERS," Leeds. HYDROGEN GUARANTEED 99% PURE. LIFTS 70-1/2 LBS. PER 1000 CUBIC FT. THE KNOWLES OXYGEN Co. LIMITED, WOLVERHAMPTON AND BROMBOROUGH (CHESHIRE). PATENTS. Stanley, Popplewell & Co., =INTERNATIONAL AND - - CHARTERED PATENT AGENTS.= _38, CHANCERY LANE, LONDON, W.C._ _Aero and Motor Patents a Specialty._ Instructive leaflet free to any address. Telephone, 1763 Central Telegrams: "NOTIONS, London." Estab. 1879. [Illustration] We specialise in Light Machine Tools for use in portable workshops, such as are used in connection with aircraft. The above is a photograph of a Travelling Workshop equipped with our 5 in. lathe and Radial Drill, both of which tools are fitted with treadle and electric motor drive. Full particulars of machines and installations furnished on application. [Illustration: 5 in. Centre Screw Cutting, Surfacing and Boring Lathe here shewn, with counter shaft for power. With counter shaft or treadle drive. Price £44.] [Illustration: Light treadle driven Radial Drill, taking up to 1 in. drills (1/2 in. shank.) This machine is of special design, a patented form of high speed drive giving ample power for drilling by foot. With treadle and fast and loose pulley. Price £24 15s.] Also 4 in., 3-1/2 in., 6 in., 7-1/2 in., 9 in. lathes, etc. _DRUMMOND BROS. LTD., REDE WORKS,_ GUILDFORD, SURREY. 'Phone 153, Guildford. Telegrams: "Lathes, Stoughton." "TEL" REVOLUTION SPEED INDICATORS. Approved and used by the British Admiralty. Owing to its conjugate movement it is accurate, possesses a uniform graduated dial and is not affected by vibration or variation of temperature. Indicates with the same accuracy high and low speeds. Independent of variable strains, friction. Not damaged should maximum speed of dial be exceeded. Rain and dust-proof. Requires no upkeep or adjustment of mechanism. [Illustration] Tel. 431 Victoria. THE HASLER COMPANY, 26, Victoria St., Westminster, LONDON, S.W. C·A·V· is the ~proved~ system of electric Lighting for Cars. The consistent reliability and efficiency of the C.A.V. Lighting Sets is vouched for by the owners of the 15,000 cars on which the system has been adopted. It is essentially the "no trouble" system; simple, safe and certain. Send for our illustrated Blue Book, fully explanatory and free. _C. A. VANDERVELL & Co._, WARPLE WAY, ACTON VALE, LONDON, W. Telephones: 1234 {Chiswick {(5 LINES) Telegrams: "Vanteria," London. Whiteman & Moss, Ltd. 15, BATEMAN STREET, DEAN STREET, W., LONDON, England. Telephone Gerrard 6824. Telegrams: Whitomoss {Premier. Codes {Lieber. {A.B.C. 5th Edition. =Speciality=: WIRE STRAINERS, EYEBOLTS, FERRULES, ETC. SCREWED WORK FOR ALL PURPOSES. Accuracy & Promptitude SPÉCIALITÉ de Passoires en toile métallique. de tire-fonds, de Viroles, etc. Objets filetés en tous genres. PRÉCISION et RAPIDITÉ. THE LEADING AIRCRAFT BUILDERS ALL use the "INCANTO" (LOW PRESSURE) OXY-ACETYLENE WELDING APPLIANCES. SOLE MANUFACTURERS THORN & HODDLE ACETYLENE CO. L^{TD}. 151 VICTORIA S^T. LONDON, S.W. INSURANCE. The Primus Aviation Policy at Lloyd's OFFICIALLY APPROVED BY THE ROYAL AERO CLUB. For Advice on:-- AVIATION, LIFE, PERSONAL ACCIDENT, 3rd PARTY, EMPLOYERS' LIABILITY, MOTOR, and all Classes of Insurance communicate with _BRAY, GIBB & Co., Ltd.,_ 166, PICCADILLY, LONDON, W. Telegrams--"SOPWITH KINGSTON." Telephone--1177, KINGSTON. _SOPWITH AVIATION Co._ THE SOPWITH MACHINES hold the British RECORDS for: _DURATION_ _8 hours 23 minutes._ _ALTITUDE_ _11,450 feet._ Undergoing War Office Tests, the SOPWITH 80 h.p. TRACTOR BIPLANE gave better results than any aeroplane of whatever nationality previously tested. _OFFICES AND WORKS:_ CANBURY PARK ROAD, KINGSTON ON THAMES. CONTRACTORS TO THE ADMIRALTY. MANUFACTURERS OF AEROPLANES AND HYDRO-AEROPLANES HARDWOODS FOR AEROPLANES. UNEQUALLED FACILITIES FOR SUPPLYING PERFECT TIMBER. SPECIAL SKILL AND GREAT EXPERIENCE DEVOTED TO ORDERS FOR AEROPLANE WOODS. ALL KINDS OF HARDWOODS IN PLANKS, OR CUT AND PLANED TO SIZE. Testimonials from successful Aviators. WILLIAM MALLINSON & SONS, Limited, TIMBER & VENEER MERCHANTS (Direct Importers & Exporters), 130-138, Hackney Road, LONDON, N.E. Telegrams: "ALMONER," LONDON. Telephone: 4770 LONDON WALL (2 Lines) P.O. 3845 CENTRAL. CORRESPONDENCE IN ANY LANGUAGE. PARIS: 7, Rue Titon. ROTTERDAM: 22 Westzeeddijh. [Illustration] =_THE "MARTINSYDE"_= _120 H.P. TWO-SEATER, MILITARY TYPE MONOPLANE. Fuel Capacity for 6 HOURS' FLIGHT, at 85 miles per hour._ _Messrs. Martin & Handasyde, BROOKLAND AVIATION GROUND, WEYBRIDGE, SURREY, ENGLAND._ _Telegraphic & Cable Address: "MARTINSYDE, WEYBRIDGE."_ CONTRACTORS TO THE WAR OFFICE. _Telephone No. 171 BYFLEET._ "AVIATOR" RAMIE FABRICS FOR AEROPLANES AND DIRIGIBLE BALLOONS. Indisputably the ~strongest~, ~most durable~ and ~efficient~ of all known fabrics, and consequently adopted by H.M. War Office, and the leading ~Aircraft Constructors~ of the ~Universe~. Manufactured from China Grass by La Maison Esnault-Pelterie (Paris) Barbet-Massin, Popelin & Cie, Succrs. Contractors to the French Government. Sole agents for the United kingdom, British Colonies, and United States of America-- =_ROGERS BROTHERS,_= _33, ALDERMANBURY,_ _LONDON, E.C._ Telephone: CENTRAL, 12164. Telegrams and Cables: "EGYPTILLO, LONDON." A.B.C. Code Used, 5th Edition. Write for Patterns and Particulars. Cables and Telegrams: "PIGGOTT, LONDON." A.B.C. Code. 5th Edition. Telephone No. London Wall 4850 (Private Exchange). PIGGOTT BROTHERS & CO., LIMITED. Portable Canvas Aeroplane Sheds on Hire, for Prize Contests, Flying Meetings, etc. As used for the Gordon Bennett and "Daily Mail" Contests, Military Man[oe]vres, 1911, and the Flying Meetings at Doncaster, Burton-on-Trent, Folkestone, etc., etc. [Illustration: Photo showing row of Canvas Sheds as erected at Brooklands for the Royal Aero Club, July, 1911.] Large Stock of Goods for Hire at Prize Contests, Flying Meetings, etc., Judges' Boxes, Pylons, Ropes and Stakes for course, Canvas Fencing, Signal Masts, etc., etc. 220, 222, 224, BISHOPSGATE, LONDON, E.C. _Telephone 3811 HOP. Telegrams: "BUCHERON."_ Joseph Owen & Sons, L^{imited,} SUPPLY EVERY DESCRIPTION OF TIMBER FOR Aeroplanes, Hydroplanes, Airships. SEND YOUR ENQUIRIES TO 199a, BOROUGH HIGH STREET, LONDON, SE. FLANDERS MONOPLANES & BIPLANES For Land or Water. L. HOWARD-FLANDERS, LIMITED, 31, Townshend Terrace, RICHMOND, Surrey. [Illustration] EISEMANN DYNAMO Although designed for use with accumulators--=gives results without= damaging filaments =without the use of accumulators=. Perfectly automatic in action. Used on the =Zeppelin=. =Types= 8 volts 9 amps. 12 volts 15-20 amps. Eisemann Automatic Advance Magneto Used on the Mercedes--Gnome--Schutte Lanz--Dixi, etc., etc. Entirely weatherproof--advances and retards the spark periodicity according to engine revolutions. Latest models as used on above engines both single and dual. Fullest Particulars on hearing from you. THE EISEMANN MAGNETO Co. 43, Berners Street, W. Telegrams:-- Roussillon-ox, London. Telephone 4601 City. A.B.C. Code 5th Edition. C. D. C. [Illustration] _The_ Aircraft of the World perform best on the best Spirit. The rapidly growing [Illustration: _Preference for_ PRATT'S Perfection Motor Spirit among airmen is a repetition of history. In Motoring, on the Road, the consistent Purity and Reliability--the sheer, hard, practical Service of "Miles to the Gallon" has long established PRATT'S as the premier Motor Spirit. "_In Earth and Skie and Sea"--PRATT'S first shall be!_ [Illustration: _By Appointment_] _In the Air, as on the Road, PRATT'S is "THE MOVING SPIRIT OF THE AGE!"_ Telegraphic Address: "JONBRO," MANCHESTER. JONES BROTHERS LIMITED, =Spinners & Manufacturers,= 12, YORK STREET, Manchester. [Illustration: BEDFORD NEW MILLS, LEIGH, LANCASHIRE.] _THE "AERO" Cotton Fabrics for Aeroplanes._ H. VALDENAIRE, ADENET & Cie. PARIS--21, Rue des Jeuneurs--PARIS. TISSUS DE GRANDE RÉSISTANCE FOURNISSEURS HABITUELS des PRINCIPALES MARQUES d'AVIATION et d'AEROSTATION KEMP MOTORS [Illustration] Are air cooled and are the most efficient, economical and reliable power plants on the market sold at reasonable prices. Built in four sizes to meet all requirements from experimental purposes to commercial use. ~FULL PARTICULARS ON REQUEST.~ KEMP MACHINE WORKS, MUNCIE, INDIANA, U.S.A. "AFTER 13 HOURS UNDER WATER" the MEA (_The Magneto with the Bell-shaped Magnet_) RAN PERFECTLY. "One of your Magnetos delivered to us last year has had a severe test, proving it to be absolutely water-proof. It was fitted to an engine in a motor boat, which towards 7 p.m. ran full of water: next morning about 9 a.m. we pumped her dry, and, after your magneto had been about 13 hours under water, it was found to be in perfect working order, and the engine started up without a hitch." MEA MAGNETO CO., LTD., Telephone: 2580 Regent. Telegrams: "Meabermet, Ox. London" GRESSE BUILDINGS, STEPHEN STREET, TOTTENHAM COURT RD., LONDON, W. LONDON AGENTS: B. M. FAIR & CO., 3. GREAT WINCHESTER STREET, E.C. C.D.C. BRANGER, Aerial Photographer, 5, Rue Cambon, 5 PARIS. "Fighting Ships" NAVAL ANNUAL FOR 1913. Founded and Edited by FRED T. JANE, _Founder & Editor "ALL THE WORLD'S AIRCRAFT."_ PLANS, PHOTOGRAPHS, AND ALL DETAILS OF EVERY WARSHIP IN THE WORLD. The details of ~13~ Navies are officially revised by order of their respective Ministers of Marine; ~3~ others semi-official. SPECIAL ARTICLE ON "MARINE ENGINEERING IN ALL ITS BRANCHES," by C. de GRAVE SELLS, M. Inst. C.E. LONDON: SAMPSON LOW, MARSTON & Co., Ltd. THE "MASCOT" RAMIE-FIBRE, ROT-PROOF [Illustration] LIFE-SAVING VEST Stocked by the Leading Stores in all Countries, or can be purchased direct from the Inventors and Sole Manufacturers-- ROGERS BROTHERS, Manufacturers of "Aeroplatte" All-British Aircraft Fabrics, and the "Aeromac" Water-proof Garments 33, ALDERMANBURY, LONDON, E.C. _Send post-card for full particulars._ Telephone, Central, 12164 Telegrams & Cables: "EGYPTILLO, London." A B C Code used. 5th Edition. VICKERS LIMITED. AVIATION SCHOOL: Brooklands. Thorough Tuition from slow Biplanes to fast Monoplanes. Special Terms to Naval and Military Officers. "VICKERS-LEVASSEUR" Air Screws. Built up in superposed layers, of the finest quality of thoroughly seasoned hardwoods, pegged & glued together. [Illustration] AEROPLANES. All steel-framed Monoplanes, Biplanes & Hydro-planes. AVIATION DEPARTMENT: VICKERS HOUSE, BROADWAY, WESTMINSTER, S.W. Aviation School: Brooklands. Testing Ground: Joyce Green, Nr. Dartford. FOOTNOTES: [Footnote A: Twelve of these _B.E._ were held up pending some special steel wire strainers which had been specified.] [Footnote B: Killed in Russia.] [Footnote C: This ship has frequently figured as four different dirigibles.] [Footnote D: P.L 9 reported sold to Turkey, April, 1913.] [Footnote E: Three other dirigibles, _Unger_, _Veeh_, and _Siemens-Schuckert_, are generally credited to Germany. Of these _Unger_ is merely a project. _Veeh_ has been talked about for four years, but has never reached completion. _Siemens-S._ has ceased to exist.] [Footnote F: Jezzi lives in England where he is a well known amateur constructor.] 
42344	----	MY AIRSHIPS [Illustration: ALBERTO SANTOS-DUMONT] MY AIRSHIPS The Story of My Life BY ALBERTO SANTOS-DUMONT ILLUSTRATED LONDON GRANT RICHARDS 1904 THE RIVERSIDE PRESS LIMITED, EDINBURGH CONTENTS PAGE INTRODUCTORY FABLE 1 CHAPTER I. THE COFFEE PLANTATION 10 II. PARIS--PROFESSIONAL BALLOONISTS--AUTOMOBILES 24 III. MY FIRST BALLOON ASCENT 33 IV. MY "BRAZIL"--SMALLEST OF SPHERICAL BALLOONS 42 V. THE REAL AND THE IMAGINARY DANGERS OF BALLOONING 51 VI. I YIELD TO THE STEERABLE BALLOON IDEA 63 VII. MY FIRST AIR-SHIP CRUISES (1898) 74 VIII. HOW IT FEELS TO NAVIGATE THE AIR 82 IX. EXPLOSIVE ENGINES AND INFLAMMABLE GASES 100 X. I GO IN FOR AIR-SHIP BUILDING 114 XI. THE EXPOSITION SUMMER 133 XII. THE DEUTSCH PRIZE AND ITS PROBLEMS 153 XIII. A FALL BEFORE A RISE 164 XIV. THE BUILDING OF MY "NO. 6" 180 XV. WINNING THE DEUTSCH PRIZE 190 XVI. A GLANCE BACKWARD AND FORWARD 205 XVII. MONACO AND THE MARITIME GUIDE ROPE 217 XVIII. FLIGHTS IN MEDITERRANEAN WINDS 232 XIX. SPEED 243 XX. AN ACCIDENT AND ITS LESSONS 256 XXI. THE FIRST OF THE WORLD'S AIR-SHIP STATIONS 264 XXII. MY "NO. 9," THE LITTLE RUNABOUT 282 XXIII. THE AIR-SHIP IN WAR 303 XXIV. PARIS AS A CENTRE OF AIR-SHIP EXPERIMENTS 318 CONCLUDING FABLE 327 LIST OF ILLUSTRATIONS PAGE Alberto Santos-Dumont _Frontispiece_ Santos-Dumont Coffee Plantation--Railway 11 Santos-Dumont Coffee Plantation--The Works 15 Henriques Santos-Dumont 25 The "Brazil"--Smallest of Spherical Balloons 43 Motor of "No. 1" 62 The "Santos-Dumont No. 1"--First Start 75 "No. 4"--Free Diagonal Movement up 83 "No. 6"--Free Diagonal Movement down 86 "The Housetops look so Dangerous" 94 Over the Bois de Boulogne. "An Ocean of Greenery soft and safe" 97 The Question of Physical Danger 101 "No. 9" catches Fire over the Ile de Puteaux 111 Accident to "No. 2," May 11, 1899 (First Phase) 115 Accident to "No. 2," May 11, 1899 (Second Phase) 119 Accident to "No. 2," May 11, 1899 (Third Phase) 123 Accident to "No. 2," May 11, 1899 (Finale) 127 Start of "No. 3," November 13, 1899 131 "No. 4" 135 Motor of "No. 4" 139 Visit of Professor Langley 143 "No. 4"--Flight before Professor Langley 147 "Santos-Dumont No. 5" 152 "No. 5" leaving Aëro Club Grounds, July 12, 1901 158 "No. 5" returning from the Eiffel Tower 161 "No. 5"--Accident in the Park of M. Edmond de Rothschild 165 An Accident 170 Phase of an Accident 175 "No. 6"--First Trip 181 An Accident to "No. 6" 187 Scientific Commission of Aëro Club at the Winning of the Deutsch Prize 191 "No. 6" making for Eiffel Tower--Altitude 1000 feet 195 Round Eiffel Tower 199 Rounding Eiffel Tower 203 Returning to Aëro Club Grounds above Aqueduct 207 Medal awarded by the Brazilian Government 211 "No. 9"--Showing Captain leaving Basket for Motor 215 In the Bay of Monaco 219 From the Balloon House of La Condamine at Monaco, February 12, 1902 227 Wind A. Wind B 237 "Santos-Dumont No. 7" 249 "My present Aids understand my present Airships"--Motor of "No. 6" 261 "Santos-Dumont No. 5"--Showing how Aëro Club Grounds were cut up 267 First of the World's Airship Stations (Neuilly St James) 271 "No. 7" 275 "No. 10"--without Passenger Keel 279 "Santos-Dumont No. 9" 283 "No. 9"--Showing relative Size 287 "No. 9"--Jumping my Wall 291 "No. 9"--Guide-roping on a Level with the Housetops 295 "No. 9"--M. Santos-Dumont lands at his own Door 299 "No. 9" over Bois de Boulogne 305 "No. 9" at Military Review, July 14, 1903 309 "No. 9" seen from Captive Balloon, June 11, 1903 325 MY AIRSHIPS INTRODUCTORY FABLE THE REASONING OF CHILDREN Two young Brazilian boys strolled in the shade, conversing. They were simple youths of the interior, knowing only the plenty of the primitive plantation where, undisturbed by labour-saving devices, Nature yielded man her fruits at the price of the sweat of his brow. They were ignorant of machines to the extent that they had never seen a waggon or a wheelbarrow. Horses and oxen bore the burdens of plantation life on their backs, and placid Indian labourers wielded the spade and the hoe. Yet they were thoughtful boys. At this moment they discussed things beyond all that they had seen or heard. "Why not devise a better means of transport than the backs of horses and of oxen?" Luis argued. "Last summer I hitched horses to a barn door, loaded it with sacks of maize, and hauled in one load what ten horses could not have brought on their backs. True, it required seven horses to drag it, while five men had to sit around its edges and hold the load from falling off." "What would you have?" answered Pedro. "Nature demands compensations. You cannot get something from nothing or more from less!" "If we could put rollers under the drag, less pulling power would be needed." "Bah! the force saved would be used up in the labour of shifting the rollers." "The rollers might be attached to the drag at fixed points by means of holes running through their centres," mused Luis. "Or why should not circular blocks of wood be fixed at the four corners of the drag?... Look, Pedro, yonder along the road. What is coming? The very thing I imagined, only better! One horse is pulling it at a good trot!" The first waggon to appear in that region of the interior stopped, and its driver spoke with the boys. "These round things?" he answered to their questions; "they are called wheels." Pedro accepted his explanation of the principle slowly. "There must be some hidden defect in the device," he insisted. "Look around us. Nowhere does Nature employ the device you call the wheel. Observe the mechanism of the human body; observe the horse's frame; observe...." "Observe that horse and man and waggon with its wheels are speeding from us," replied Luis, laughing. "Cannot you yield to accomplished facts? You tire me with your appeals to Nature. Has man ever accomplished anything worth having except by combating Nature? We do violence to her when we chop down a tree! I would go further than this invention of the waggon. Conceive a more powerful motive force than that horse...." "Attach two horses to the waggon." "I mean a machine," said Luis. "A mechanical horse with powerful iron legs!" suggested Pedro. "No; I would have a motor waggon. If I could find an artificial force I would cause it to act on a point in the circumference of each wheel. Then the waggon could carry its own puller!" "You might as well attempt to lift yourself from the ground by pulling at your boot straps!" laughed Pedro. "Listen, Luis. Man is subject to certain natural laws. The horse, it is true, carries more than his own weight, but by a device of Natures own--his legs. Had you the artificial force you dream of you would have to apply it naturally. I have it! It would have to be applied to poles to push your waggon from behind!" "I hold to applying the force to the wheels," insisted Luis. "By the nature of things you would lose power," said Pedro. "A wheel is harder to force on from a point inside its circumference than when the motive power is applied to that circumference directly, as by pushing or pulling the waggon." "To relieve friction I would run my power waggon on smooth iron rails, then the loss in power would be gained in speed." "Smooth iron rails!" laughed Pedro. "Why, the wheels would slip on them. You would have to put notches all round their circumference and corresponding notches in the rails. And what would there be to prevent the power waggon slipping off the rails even then?" The boys had been walking briskly. Now a shrieking noise startled them. Before them stretched in long lines a railway in course of construction, and from among the hills came toward them, at what seemed immense speed, a construction train. "It is an avalanche!" cried Pedro. "It is the very thing that I was dreaming of!" said Luis. The train stopped. A gang of labourers emerged from it and began working on the road-bed, while the locomotive engineer answered the boys' questions and explained the mechanism of his engine. The boys discussed this later wonder as they wended their way homeward. "Could it be adapted to the river men might become lords of the water as of the land," said Luis. "It would be only necessary to devise wheels capable of taking hold of the water. Fix them to a great frame like that waggon body and the steam-engine could propel it along the surface of the river!" "Now you talk folly," exclaimed Pedro. "Does a fish float on the surface? In the water we must travel as the fish does--in it, not over it! Your waggon body, being filled with light air, would upset at your first movement. And your wheels--do you imagine they would take hold of so liquid a thing as water?" "What would you suggest?" "I would suggest that your water waggon be jointed in half-a-dozen places, so that it could be made to squirm through the water like a fish. Listen! A fish navigates the water. You desire to navigate the water. Then study the fish! There are fish that use propeller fins and flippers too. So you might devise broad boards to strike the water, as our hands and feet strike it in swimming. But do not talk about waggon wheels in the water!" They were now beside the broad river. The first steamer to navigate it was seen approaching from the distance. The boys could not yet well distinguish it. "It is evidently a whale," said Pedro. "What navigates the water? Fish. What is the fish that sometimes is seen swimming with its body half way above the surface? The whale. See, it is spouting water!" "That is not water, but steam or smoke," said Luis. "Then it is a dead whale, and the steam is the vapour of putrefaction. That is why it stays so high in the water--a dead whale rises high on its back!" "No," said Luis; "it is really a steam water waggon." "With smoke coming from fire in it, as from the locomotive?" "Yes." "But the fire would burn it up...." "The body is doubtless iron, like the locomotive." "Iron would sink. Throw your hatchet in the river and see." The steam-boat came to shore, close to the boys. Running to it, to their joy, they perceived on its deck an old friend of their family, a neighbouring planter. "Come, boys!" he said, "and I will show you round this steam-boat." After a long inspection of the machinery the two boys sat with their old friend on the foredeck in the shade of an awning. "Pedro," said Luis, "will not men some day invent a ship to sail in the sky?" The common-sense old planter glanced with apprehension at the youth's face, flushed with ardour. "Have you been much in the sun, Luis?" he asked. "Oh, he is always talking in that flighty way," Pedro reassured him. "He takes pleasure in it." "No, my boy," said the planter; "man will never navigate a ship in the sky." "But on St John's Eve, when we all make bonfires, we also send up little tissue-paper spheres with hot air in them," insisted Luis. "If we could construct a very great one, big enough to lift a man, a light car, and a motor, might not the whole system be propelled through the air, as a steam-boat is propelled through the water?" "Boys, never talk foolishness!" exclaimed the old friend of the family hurriedly as the captain of the boat approached. It was too late. The captain had heard the boy's observation; instead of calling it folly he excused him. "The great balloon which you imagine has existed since 1783," he said; "but, though capable of carrying a man or several men, it cannot be controlled--it is at the mercy of the slightest breeze. As long ago as 1852 a French engineer named Giffard made a brilliant failure with what he called a 'dirigible balloon,' furnished with the motor and propeller Luis has dreamed of. All he did was to demonstrate the impossibility of directing a balloon through the air." "The only way would be to build a flying machine on the model of the bird," spoke up Pedro with authority. "Pedro is a very sensible boy," observed the old planter. "It is a pity Luis is not more like him and less visionary. Tell me, Pedro, how did you come to decide in favour of the bird as against the balloon?" "Easily," replied Pedro glibly. "It is the most ordinary-common sense. Does man fly? No. Does the bird fly? Yes. Then if man would fly let him imitate the bird. Nature has made the bird, and Nature never goes wrong. Had the bird been furnished with a great air bag I might have suggested a balloon." "Exactly!" exclaimed both captain and planter. But Luis, sitting in his corner, muttered, unconvinced as Galileo: "It will move!" CHAPTER I THE COFFEE PLANTATION From the way in which the partisans of Nature have fallen on me I might well be the uninformed and visionary Luis of the fable, for has it not been taken for granted that I began my experiments ignorant alike of mechanics and ballooning? And before my experiments succeeded, were they not all called impossible? Does not the final condemnation of the common-sense Pedro continue to weigh on me? After steering my ship through the sky at will I am still told that flying creatures are heavier than the air. A little more and I should be made responsible for the tragic accidents of others who had not my experience of mechanics and aeronautics. On the whole, therefore, I think it is best to begin at the coffee plantation where I was born in the year 1873. [Illustration: PLANTATION RAILWAY SANTOS-DUMONT COFFEE PLANTATION IN BRAZIL] Inhabitants of Europe comically figure those Brazilian plantations to themselves as primitive stations of the boundless pampas, as innocent of the cart and the wheelbarrow as of the electric light and the telephone. There are such stations far in the interior. I have been through them on hunting trips, but they are not the coffee plantations of Sao-Paulo. I can hardly imagine a more stimulating environment for a boy dreaming over mechanical inventions. At the age of seven I was permitted to drive our "locomobiles" of the epoch--steam traction-engines of the fields with great broad wheels. At the age of twelve I had conquered my place in the cabs of the Baldwin locomotive engines hauling train-loads of green coffee over the sixty miles of our plantation railway. When my father and brothers would take pleasure in making horseback trips far and near, to see if the trees were clean, if the crops were coming up, if the rains had done damage, I preferred to slip down to the Works and play with the coffee-engines. I think it is not generally understood how scientifically a Brazilian coffee plantation may be operated. From the moment when a railway train has brought the green berries to the Works to the moment when the finished and assorted product is loaded on the transatlantic ships, no human hand touches the coffee. You know that the berries of black coffee are red when they are green. Though it may complicate the statement, they look like cherries. Car loads of them are unloaded at the central works and thrown into great tanks, where the water is continually renewed and agitated. Mud that has clung to the berries from the rains, and little stones which have got mixed up with them in the loading of the cars, go to the bottom, while the berries and the little sticks and bits of leaves float on the surface and are carried from the tank by means of an inclined trough, whose bottom is pierced with innumerable little holes. Through these holes falls some of the water with the berries, while the little sticks and pieces of leaves float on. [Illustration: THE WORKS] [Illustration: "LOCOMOBILE" THE SANTOS-DUMONT COFFEE PLANTATION IN BRAZIL] The fallen coffee berries are now clean. They are still red, about the size and look of cherries. The red exterior is a hard pod or _polpa_. Inside of each pod are two beans, each of which is covered with a skin of its own. The water which has fallen with the berries carries them on to the machine called the _despolpador_, which breaks the outside pod and frees the beans. Long tubes, called "dryers," now receive the beans, still wet, and with their skins still on them. In these dryers the beans are continually agitated in hot air. Coffee is very delicate. It must be handled delicately. Therefore the dried beans are lifted by the cups of an endless-chain elevator to a height, whence they slide down an inclined trough to another building because of the danger of fire. This is the coffee machine house. The first machine is a ventilator, in which sieves, shaken back and forth, are so combined that only the coffee beans can pass through them. No coffee is lost in them and no dirt is kept by them, for one little stone or stick that may still have been carried with the beans would be enough to break the next machine. Another endless-chain elevator carries the beans to a height, whence they fall through an inclined trough into this _descascador_ or "skinner." It is a highly delicate machine; if the spaces between are a trifle too big the coffee passes without being skinned, while if they are too small they break the beans. Another elevator carries the skinned beans with their skins to another ventilator, in which the skins are blown away. Still another elevator takes the now clean beans up and throws them into the "separator," a great copper tube two yards in diameter and about seven yards long, resting at a slight incline. Through the separator tube the coffee slides. As it is pierced at first with little holes the smaller beans fall through them. Farther along it is pierced with larger holes, and through these the medium-sized beans fall, and still farther along are still larger holes, for the large round beans called "Moka." The machine is a separator because it separates the beans into their conventional grades by size. Each grade falls into its hopper, beneath which are stationed weighing scales and men with coffee sacks. As the sacks fill up to the required weight they are replaced by empty ones, and the tied and labelled sacks are shipped to Europe. As a boy I played with this machinery and the driving engines that furnished its motive force, and before long familiarity had taught me how to repair any part of it. As I have said, it is delicate machinery. In particular, the moving sieves would be continually getting out of order. While they were not heavy, they moved back and forth horizontally at great speed and took an enormous amount of motive power. The belts were always being changed, and I remember the fruitless efforts of all of us to remedy the mechanical defects of the device. Now is it not curious that those troublesome shifting sieves were the only machines at the coffee works that were not rotary? They were not rotary, and they were bad. I think this put me as a boy against all _agitating_ devices in mechanics and in favour of the more easily-handled and more serviceable rotary movement. It may be that half-a-century from now man will assume mastery of the air by means of flying machines heavier than the medium in which they move. I look forward to the time with hope, and at the present moment I have gone further to meet it than any other, because my own air-ships (which have been so reproached on this head) are slightly heavier than the air. But I am prejudiced enough to think that when the time comes the conquering device will not be flapping wings or any substitute of an agitating nature. I cannot say at what age I made my first kites, but I remember how my comrades used to tease me at our game of "Pigeon flies!" All the children gather round a table, and the leader calls out: "Pigeon flies!" "Hen flies!" "Crow flies!" "Bee flies!" and so on, and at each call we were supposed to raise our fingers. Sometimes, however, he would call out "Dog flies!" "Fox flies!" or some other like impossibility, to catch us. If anyone raised a finger he was made to pay a forfeit. Now my playmates never failed to wink and smile mockingly at me when one of them called "Man flies!" for at the word I would always lift my finger very high, as a sign of absolute conviction, and I refused with energy to pay the forfeit. Among the thousands of letters which I received after winning the Deutsch prize there was one that gave me particular pleasure. I quote from it as a matter of curiosity: "... Do you remember the time, my dear Alberto, when we played together 'Pigeon flies!'? It came back to me suddenly the day when the news of your success reached Rio. "'Man flies!' old fellow! You were right to raise your finger, and you have just proved it by flying round the Eiffel Tower. "You were right not to pay the forfeit; it is M. Deutsch who has paid it in your stead. Bravo! you well deserve the 100,000 franc prize. "They play the old game now more than ever at home, but the name has been changed and the rules modified--since October 19, 1901. They call it now 'Man flies!' and he who does not raise his finger at the word pays his forfeit.-- Your friend, PEDRO." This letter brings back to me the happiest days of my life, when I exercised myself in making light aeroplanes with bits of straw, moved by screw propellers driven by springs of twisted rubber, or ephemeral silk-paper balloons. Each year, on June 24th, over the St John bonfires, which are customary in Brazil from long tradition, I inflated whole fleets of these little Montgolfiers, and watched in ecstasy their ascension to the skies. In those days, I confess, my favourite author was Jules Verne. The wholesome imagination of this truly great writer, working magically with the immutable laws of matter, fascinated me from childhood. In its daring conceptions I saw, never doubting, the mechanics and the science of the coming ages, when man should by his unaided genius rise to the height of a demigod. With Captain Nemo and his shipwrecked guests I explored the depths of the sea in that first of all submarines, the _Nautilus_. With Phineas Fogg I went round the world in eighty days. In "Screw Island" and "The Steam House" my boyish faith leaped out to welcome the ultimate triumphs of an automobilism that in those days had not as yet a name. With Hector Servadoc I navigated the air. I saw my first balloon in 1888, when I was about fifteen years old. There was a fair or celebration of some sort at the town of Sao-Paulo, and a professional made the ascent, letting himself down afterwards in a parachute. By this time I was perfectly familiar with the history of Montgolfier and the balloon craze, which, following on his courageous and brilliant experiments, so significantly marked the last years of the eighteenth, and the first years of the nineteenth, centuries. In my heart I had an admiring worship for the four men of genius--Montgolfier, and the physicist, Charles, and Pilâtre de Rozier, and the engineer, Henry Giffard--who have attached their names for ever to great steps forward in aerial navigation. I, too, desired to go ballooning. In the long, sun-bathed Brazilian afternoons, when the hum of insects, punctuated by the far-off cry of some bird, lulled me, I would lie in the shade of the verandah and gaze into the fair sky of Brazil, where the birds fly so high and soar with such ease on their great outstretched wings, where the clouds mount so gaily in the pure light of day, and you have only to raise your eyes to fall in love with space and freedom. So, musing on the exploration of the vast aerial ocean, I, too, devised air-ships and flying machines in my imagination. These imaginations I kept to myself. In those days, in Brazil, to talk of inventing a flying machine or dirigible balloon would have been to mark oneself off as unbalanced and visionary. Spherical balloonists were looked on as daring professionals, not differing greatly from acrobats; and for the son of a planter to dream of emulating them would have been almost a social sin. CHAPTER II PARIS--PROFESSIONAL BALLOONISTS--AUTOMOBILES In 1891 it was decided that our family should make a trip to Paris, and I rejoiced doubly at the prospect. All good Americans are said to go to Paris when they die. But to me, with the bias of my reading, France--the land of my father's ancestors and of his own education as an engineer at the École Centrale--represented everything that is powerful and progressive. In France the first hydrogen balloon had been let loose and the first air-ship had been made to navigate the air with its steam-engine, screw propeller, and rudder. Naturally I figured to myself that the problem had made marked progress since Henry Giffard in 1852, with a courage equal to his science, gave his masterly demonstration of the problem of directing balloons. I said to myself: "I am going to Paris to see the new things--steerable balloons and automobiles!" [Illustration: HENRIQUES SANTOS-DUMONT FATHER OF A. SANTOS-DUMONT AND FOUNDER OF THE COFFEE PLANTATIONS IN BRAZIL] On one of my first free afternoons, therefore, I slipped away from the family on a tour of exploration. To my immense astonishment I learned that there were no steerable balloons--that there were only spherical balloons, like that of Charles in 1783! In fact, no one had continued the trials of an elongated balloon driven by a thermic motor begun by Henry Giffard. The trials of such balloons with an electric motor, undertaken by the Tissandier brothers in 1883, had been repeated by two constructors in the following year, but had been finally given up in 1885. For years no "cigar-shaped" balloon had been seen in the air. This threw me back on spherical ballooning. Consulting the Paris city directory I had noted the address of a professional aeronaut. To him I explained my desires. "You want to make an ascent?" he asked gravely. "Hum! hum! Are you sure you have the courage? A balloon ascent is no small thing, and you seem too young." I assured him both of my purpose and my courage. Little by little he yielded to my arguments. Finally he consented to take me "for a short ascent." It must be on a calm, sunny afternoon, and not last more than two hours. "My honorarium will be 1200 francs," he added, "and you must sign me a contract to hold yourself responsible for all damages we may do to your own life and limbs and to mine, to the property of third parties, and to the balloon and its accessories. Furthermore, you agree to pay out railway fares and transportation for the balloon and its basket back to Paris from the point at which we come to the ground." I asked time for reflection. To a youth eighteen years of age 1200 francs was a large sum. How could I justify the spending of it to my parents? Then I reflected: "If I risk 1200 francs for an afternoon's pleasure I shall find it either good or bad. If it is bad the money will be lost. If it is good I shall want to repeat it and I shall not have the means." This decided me. Regretfully I gave up ballooning and took refuge in automobiling. Automobiles were still rare in Paris in 1891, and I had to go to the works at Valentigny to buy my first machine, a Peugeot three-and-a-half horse-power roadster. It was a curiosity. In those days there were no automobile licenses, no "chauffeurs'" examinations. We drove our new inventions through the streets of the capital at our own risks and perils. Such was the curiosity they aroused that I was not allowed to stop in public places like the Place de l'Opéra for fear of attracting multitudes and obstructing traffic. Immediately I became an enthusiastic automobilist. I took pleasure in understanding the parts and their proper interworking; I learned to care for my machine and to repair it; and when, at the end of some seven months, our whole family returned to Brazil I took the Peugeot roadster with me. Returning to Paris in 1892, with the balloon idea still obsessing me, I looked up a number of other professional aeronauts. Like the first, all wanted extravagant sums to take me up with them on the most trivial kind of ascent. All took the same attitude. They made a danger and a difficulty of ballooning, enlarging on its risks to life and property. Even in presence of the great prices they proposed to charge me they did not encourage me to close with them. Obviously they were determined to keep ballooning to themselves as a professional mystery. Therefore I bought a new automobile. I should add that this condition of things has changed wonderfully since the foundation of the Paris Aéro Club. Automobile tricycles were just then coming to the fore. I chose one, and rejoiced in its freedom from breakdowns. In my new enthusiasm for the type, I was the first to introduce motor-tricycle races in Paris. Renting the bicycle track of the Parc des Princes for an afternoon I organised the race and offered the prizes. "Common-sense" people declared that the event would end disastrously; they proved to their own satisfaction that the tricycles, going round the short curves of a bicycle track, would overturn and wreck themselves. If they did not do this the inclination would certainly cause the carburator to stop or not to work so well, and the stoppage of the carburator round the sharp curve would upset the tricycles. The directors of the Vélodrome, while accepting my money, refused to let me have the track for a Sunday afternoon, fearing a fiasco! They were disappointed when the race proved to be a great success. Returning again to Brazil I regretted bitterly that I had not persevered in my attempt to make a balloon ascent. At that distance, far from ballooning possibilities, even the high prices demanded by the aeronauts seemed to me of secondary importance. Finally, one day in 1897, in a Rio book-shop, when making my purchases of reading matter for a new voyage to Paris, I came on a volume of MM. Lachambre and Machuron, "Andrée--Au Pôle Nord en Ballon." The reading of this book during the long sea voyage proved a revelation to me, and I finished by studying it like a text-book. Its description of materials and prices opened my eyes. At last I saw clearly. Andrée's immense balloon--a reproduction of whose photograph on the book cover showed how those who gave it the final varnishing climbed up its sides and over its summit like a mountain--cost only 40,000 francs to fully construct and equip! I determined that on arriving in Paris I would cease consulting professional aeronauts and would make the acquaintance of constructors. I was particularly anxious to meet M. Lachambre, the builder of the Andrée balloon, and M. Machuron, who was his associate and the writer of the book. In these men I will say frankly that I found all I had hoped for. When I asked M. Lachambre how much it would cost me to take a short trip in one of his balloons his reply so astonished me that I asked him to repeat it. "For a long trip of three or four hours," he said, "it will cost you 250 francs, all expenses and return of balloon by rail included." "And the damages?" I asked. "We shall not do any damage!" he replied, laughing. I closed with him on the spot, and M. Machuron agreed to take me up the next day. CHAPTER III MY FIRST BALLOON ASCENT I have kept the clearest remembrance of the delightful sensations I experienced in this my first trial in the air. I arrived early at the Parc d'Aerostation of Vaugirard so as to lose nothing of the preparations. The balloon, of a capacity of 750 cubic metres, was lying a flat mass on the grass. At a signal from M. Lachambre the workmen turned on the gas, and soon the formless thing rounded up into a great sphere and rose into the air. At 11 A.M. all was ready. The basket rocked prettily beneath the balloon, which a mild, fresh breeze was caressing. Impatient to be off, I stood in my corner of the narrow wicker basket with a bag of ballast in my hand. In the other corner M. Machuron gave the word: "Let go all!" Suddenly the wind ceased. The air seemed motionless around us. We were off, going at the speed of the air current in which we now lived and moved. Indeed, for us, there was no more wind; and this is the first great fact of all spherical ballooning. Infinitely gentle is this unfelt movement forward and upward. The illusion is complete: it seems not to be the balloon that moves but the earth that sinks down and away. At the bottom of the abyss, which already opened 1500 yards below us, the earth, instead of appearing round like a ball, shows concave like a bowl by a peculiar phenomenon of refraction whose effect is to lift up constantly to the aeronaut's eyes the circle of the horizon. Villages and woods, meadows and chateaux, pass across the moving scene, out of which the whistling of locomotives throws sharp notes. These faint, piercing sounds, together with the yelping and barking of dogs, are the only noises that reach one through the depths of the upper air. The human voice cannot mount up into these boundless solitudes. Human beings look like ants along the white lines that are highways, and the rows of houses look like children's playthings. While my gaze was still held fascinated on the scene a cloud passed before the sun. Its shadow cooled the gas in the balloon, which wrinkled and began descending, gently at first, and then with accelerated speed, against which we strove by throwing out ballast. This is the second great fact of spherical ballooning--we are masters of our altitude by the possession of a few pounds of sand! Regaining our equilibrium above a plateau of clouds at about 3000 yards we enjoyed a wonderful sight. The sun cast the shadow of the balloon on this screen of dazzling whiteness, while our own profiles, magnified to giant size, appeared in the centre of a triple rainbow! As we could no longer see the earth all sensation of movement ceased. We might be going at storm speed and not know it. We could not even know the direction we were taking save by descending below the clouds to regain our bearings. A joyous peal of bells mounted up to us. It was the noonday Angelus ringing from some village belfry. I had brought up with us a substantial lunch of hard-boiled eggs, cold roast beef and chicken, cheese, ice-cream, fruits and cakes, champagne, coffee, and Chartreuse. Nothing is more delicious than lunching like this above the clouds in a spherical balloon. No dining-room can be so marvellous in its decoration. The sun sets the clouds in ebullition, making them throw up rainbow jets of frozen vapour like great sheaves of fireworks all around the table. Lovely white spangles of the most delicate ice formation scatter here and there by magic; while flakes of snow form, moment by moment, out of nothingness, beneath our very eyes, and in our very drinking-glasses. I was finishing my little glass of liqueur when the curtain suddenly fell on this wonderful stage setting of sunlight, cloud billows, and azure. The barometer rose rapidly 5 millimetres, showing a sudden rupture of equilibrium and a swift descent. Probably the balloon had become loaded down with several pounds of snow, and it was falling into a cloud. We passed into the half darkness of the fog. We could still see our basket, our instruments, and the parts of the rigging nearest us, but the netting that held us to the balloon was visible only to a certain height, and the balloon itself had completely disappeared. So we had for a moment the strange and delightful sensation of hanging in the void without support, of having lost our last ounce of weight in a limbo of nothingness, sombre and portentous. After a few minutes of fall, slackened by throwing out more ballast, we found ourselves under the clouds at a distance of about 300 yards from the ground. A village fled away from us below. We took our bearings with the compass, and compared our route map with the immense natural map that unfolded below. Soon we could identify roads, railways, villages, and forests, all hastening toward us from the horizon with the swiftness of the wind itself. The storm which had sent us downward marked a change of weather. Now little gusts began to push the balloon from right to left, up and down. From time to time the guide rope--a great rope dangling 100 yards below our basket--would touch earth, and soon the basket, too, began to graze the tops of trees. What is called "guide-roping" thus began for me under conditions peculiarly instructive. We had a sack of ballast at hand, and when some special obstacle rose in our path, like a tree or a house, we threw out a few handfuls of sand to leap up and pass over it. More than 50 yards of the guide rope dragged behind us on the ground; and this was more than enough to keep our equilibrium under the altitude of 100 yards, above which we decided not to rise for the rest of the trip. This first ascent allowed me to appreciate fully the utility of this simple part of the spherical balloon's rigging, without which its landing would usually present grave difficulties. When, for one reason or another--humidity gathering on the surface of the balloon, a downward stroke of wind, accidental loss of gas, or, more frequently, the passing of a cloud before the face of the sun--the balloon came back to earth with disquieting speed, the guide rope would come to rest in part on the ground, and so, unballasting the whole system by so much of its weight, stopped, or at least eased, the fall. Under contrary conditions any too rapid upward tendency of the balloon was counterbalanced by the lifting of the guide rope off the ground, so that a little more of its weight became added to the weight of the floating system of the moment before. Like all human devices, however, the guide rope, along with its advantages, has its inconveniences. Its rubbing along the uneven surfaces of the ground--over fields and meadows, hills and valleys, roads and houses, hedges and telegraph wires--gives violent shocks to the balloon. Or it may happen that the guide rope, rapidly unravelling the snarl in which it has twisted itself, catches hold of some asperity of the surface or winds itself around the trunk or branches of a tree. Such an incident was alone lacking to complete my instruction. As we passed a little group of trees a shock stronger than any hitherto felt threw us backward in the basket. The balloon had stopped short, and was swaying in the wind gusts at the end of its guide rope, which had curled itself around the head of an oak. For a quarter of an hour it kept us shaking like a salad-basket, and it was only by throwing out a quantity of ballast that we finally got ourselves loose. The lightened balloon made a tremendous leap upward and pierced the clouds like a cannon-ball. Indeed, it threatened to reach dangerous heights, considering the little ballast we had remaining in store for use in descending. It was time to have recourse to effective means, to open the manoeuvre valve and let out a portion of our gas. It was the work of a moment. The balloon began descending to earth again, and soon the guide rope again rested on the ground. There was nothing to do but to bring the trip to an end, because only a few handfuls of sand remained to us. He who wishes to navigate an air-ship should first practise a good many landings in a spherical balloon--that is, if he wishes to land without breaking balloon, keel, motor, rudder, propeller, water-ballast cylinders, and fuel holders. The wind being rather strong, it was necessary to seek shelter for this last manoeuvre. At the end of the plain a corner of the forest of Fontainebleau was hurrying toward us. In a few moments we had turned the extremity of the wood, sacrificing our last handful of ballast. The trees now protected us from the violence of the wind, and we cast anchor, at the same time opening wide the emergency valve for the wholesale escape of the gas. The twofold manoeuvre landed us without the least dragging. We set foot on solid ground, and stood there watching the balloon die. Stretched out in the field, it was losing the remains of its gas in convulsive agitations, like a great bird that dies in beating its wings. After taking a dozen instantaneous photographs of the dying balloon we folded it and packed it in the basket with its netting folded alongside. The little chosen corner in which we had landed formed part of the grounds of the Chateau de la Ferrière, belonging to M. Alphonse de Rothschild. Labourers from a neighbouring field were sent for a conveyance to the village of La Ferrière itself, and half-an-hour later a brake came. Putting everything into it we set off to the railway station, which was some 4 kilometres (2-1/2 miles) distant. There we had some work to lift the basket with its contents to the ground, as it weighed 200 kilogrammes (440 pounds). At 6.30 we were back at Paris, after a journey of 100 kilometres (more than 60 miles), and nearly two hours passed in the air. CHAPTER IV MY "BRAZIL"--SMALLEST OF SPHERICAL BALLOONS I liked ballooning so much that, coming back from my first trip with M. Machuron, I told him that I wanted a balloon built for myself. He liked the idea. He thought that I wanted an ordinary-sized spherical balloon, between 500 and 2000 cubic metres in volume. No one would think of making one smaller. It is only a short time ago, but it is curious how constructors still clung to heavy materials. The smallest balloon basket had to weigh 30 kilogrammes (66 lbs.). Nothing was light--neither envelope, rigging, nor accessories. I gave M. Machuron my ideas. He cried out against it when I told him I wanted a balloon of the lightest and toughest Japanese silk, 100 cubic metres (about 3500 cubic feet) in volume. At the works both he and M. Lachambre tried to prove to me that the thing was impossible. [Illustration: "THE BRAZIL" SMALLEST OF SPHERICAL BALLOONS] How often have things been proved to me impossible! Now I am used to it I expect it. But in those days it troubled me. Still I persevered. They showed me that for a balloon to have "stability" it must have a certain weight. Again, a balloon of 100 cubic metres, they said, would be affected by the movements of the aeronaut in his basket much more than a large balloon of regulation size. [Illustration: Fig. 1.] [Illustration: Fig. 2.] With a large balloon the centre of gravity in the weight of the aeronaut is as in Fig. 1, _a_. When the aeronaut moves, say, to the right in his basket, Fig. 1, _b_, the centre of gravity of the whole system is not shifted appreciably. In a very small balloon the centre of gravity, Fig. 2, _a_, is undisturbed only so long as the aeronaut sits straight in the centre of his basket. When he moves to the right the centre of gravity, Fig. 2, _b_, is shifted beyond the vertical line of the balloon's circumference, causing the balloon to swing in the same direction. Therefore, they said, your necessary movements in the basket will cause your little balloon to roll and swing continually. "We shall make the suspension tackle longer in proportion," I replied. It was done, and the "Brazil" proved remarkably stable. When I brought my light Japanese silk to M. Lachambre he looked at it and said: "It will be too weak." But when we came to try it with the dynamometer it surprised us. Tested thus, Chinese silk stands over 1000 kilogrammes (or 2200 lbs.) strain to the linear metre (3·3 feet). The thin Japanese silk stood a strain of 700 kilogrammes (1540 lbs.)--that is, it proved to be thirty times stronger than necessary according to the theory of strains. This is astonishing when you consider that it weighs only 30 grammes (a little more than one ounce) per square metre. To show how experts may be mistaken in their merely off-hand judgments I have been building my air-ship balloons of this same material; yet the inside pressure they have to stand is enormous, while all spherical balloons have a great hole in the bottom to relieve it. As the proportions finally adopted for the "Brazil" were 113 cubic metres (4104 cubic feet), corresponding to about 113 square metres (135 square yards) of silk surface, the whole envelope weighed scarcely 3-1/2 kilogrammes (less than 8 lbs.). But the weight of the varnish, three coats, brought it up to 14 kilogrammes (about 31 lbs.). The net, which often weighs into the hundreds of lbs., weighed 1800 grammes, or nearly 4 lbs. The basket, which usually weighs 30 kilogrammes (66 lbs.) at a minimum, weighed 6 kilogrammes (13 lbs.); the basket which I now have with my little "No. 9" weighs less than 5 kilogrammes (11 lbs.). My guide rope, small, but very long--100 yards--weighed at most 8 kilogrammes (17-1/2 lbs.); its length gave the "Brazil" a good spring. Instead of an anchor I put in a little grappling-iron of 3 kilogrammes (6-1/2 lbs.). Making everything light in this way I found that, in spite of the smallness of the balloon, it would have ascensional force to take up my own weight of 50 kilogrammes (110 lbs.) and 30 kilogrammes (66 lbs.) of ballast. As a fact, I took up that amount on my first trip. On another occasion, when a French Cabinet Minister was present, anxious to see the smallest spherical balloon ever made, I had practically no ballast at all, only 4 or 5 kilogrammes (10 or 11 lbs.). Nevertheless, causing the balloon to be weighed, I went up, and made a good ascent. The "Brazil" was very handy in the air--easy to control. It was easy to pack also on descending, and the story that I carried it in a valise is true. Before starting out in my little "Brazil" I made from twenty-five to thirty ascents in ordinary spherical balloons, quite alone, as my own captain and sole passenger. M. Lachambre had many public ascents, and allowed me to do some of them for him. Thus I made ascents in many parts of France and Belgium. As I got the pleasure and the experience, and as I saved him the labour and paid all my own expenses and damages, it was a mutually advantageous arrangement. I do not believe that, without such previous study and experience with a spherical balloon, a man can be capable of succeeding with an elongated dirigible balloon, whose handling is so much more delicate. Before attempting to direct an air-ship it is necessary to have learned in an ordinary balloon the conditions of the atmospheric medium, to have become acquainted with the caprices of the wind, and to have gone thoroughly into the difficulties of the ballast problem from the triple point of view of starting, of equilibrium in the air, and of landing at the end of the trip. To have been oneself the captain of an ordinary balloon at the very least a dozen times seems to me an indispensable preliminary to acquiring an exact notion of the requisites for constructing and handling an elongated balloon furnished with its motor and propeller. Naturally, I am filled with amazement when I see inventors, who have never set a foot in the basket, drawing up on paper--and even executing in whole or in part--fantastic air-ships, whose balloons are to have a capacity of thousands of cubic metres, loaded down with enormous motors which they do not succeed in raising from the ground, and furnished with machinery so complicated that nothing works! Such inventors are afraid of nothing, because they have no idea of the difficulties of the problem. Had they previously journeyed through the air at the wind's will, and amid all the disturbing influences of atmospheric phenomena, they would understand that a dirigible balloon, to be practical, requires first of all to have the utmost extreme of simplicity in all its mechanism. Some of the unhappy constructors who have paid with their lives the forfeit of their rashness had never made a single responsible ascent as captain of a spherical balloon! And the majority of their emulators, now so devotedly labouring, are in the same inexperienced condition. This is my explanation of their lack of success. They are in the condition in which the first-comer would find himself were he to agree to build and steer a transatlantic liner without having ever quitted land or set foot in a boat! CHAPTER V THE REAL AND THE IMAGINARY DANGERS OF BALLOONING One of the most astonishing adventures I had during this period of spherical ballooning took place directly over Paris. I had started from Vaugirard with four invited guests in a large balloon constructed for me after I had tired of making solitary trips in the little "Brazil." From the start there seemed to be very little wind. I rose slowly, seeking an air current. At 1000 metres (3/5 of a mile high) I found nothing. At 1500 metres (one mile) we still remained almost stationary. Throwing out more ballast we rose to 2000 metres (1-1/4 mile), when a vagrant breeze started to take us over the centre of Paris. When we had arrived at a point over the Louvre ... it left us! We descended ... and found nothing! Then happened the ludicrous thing. In a blue sky without a cloud, bathed in sunlight, and with the faint yelps of all the dogs of Paris mounting to our ears, we lay becalmed! Up we went again, hunting an air current. Down we went again, hunting an air current. Up and down, up and down! Hour after hour passed, and we remained always hanging, always over Paris! At first we laughed. Then we grew tired. Then almost alarmed. At one time I had even the idea of landing in Paris itself, near the Gare de Lyon, where I perceived an open space. Yet the attempt would have been dangerous, because my four companions could not be depended on for coolness in an emergency. They had not the ballooning habit. Worst of all, we were now losing gas. Drifting slowly eastward hour after hour one by one the sacks of ballast had been emptied. By the time that we had reached the Vincennes wood we had begun to throw out miscellaneous objects--ballast-sacks, the luncheon-baskets, two light camp-stools, two kodaks, and a case of photographic plates! All during this latter period we were quite low--not over 300 yards above the tree-tops. Now, as we sank lower, we had a real fright. Would not the guide rope at least curl itself around some tree and hold us there for hours? So we struggled to maintain our altitude above the tree-tops, until all at once a queer little wind gust took us over the Vincennes racecourse. "Now is our time!" I exclaimed to my companions. "Hold fast!" With this I pulled on the valve rope, and we came down with celerity but scarcely any shock. Personally, I have felt not only fear but also pain and real despair in a spherical balloon. It has not been often, because no sport is more regularly safe and mild and pleasurable. Such real dangers as it has are confined usually to the landing, and the balloonist of experience knows how to meet them; while from its imaginary dangers in the air one is regularly very safe. Therefore the particular adventure, full of pain and fear, that I recall to mind was all the more remarkable in that it occurred in high altitude. It happened at Nice in 1900, when I went up from the Place Masséna in a good-sized spherical balloon, alone, and intending to drift a few hours only amid the enchanting scenery of the mountains and the sea. The weather was fine, but the barometer soon fell, indicating storm. For a time the wind took me in the direction of Cimiez, but as I rose it threatened to carry me out to sea. I threw out ballast, abandoned the current, and mounted to the height of about a mile. Shortly after this I let the balloon go down again, hoping to find a safe air current, but when within 300 yards of the ground, near the Var, I noticed that I had ceased descending. As I had determined to land soon in any case I pulled on the valve rope and let out more gas. And here the terrible experience began. I could not go down. I glanced at the barometer, and found, indeed, that I was going up. Yet I ought to be descending, and I felt--by the wind and everything--that I must be descending. Had I not let out gas? To my great uneasiness I discovered only too soon what was wrong. In spite of my continuous apparent descent I was, nevertheless, being lifted by an enormous column of air rushing upward. While I fell in it I rose rapidly higher with it. I opened the valve again; it was useless. The barometer showed that I had reached a still greater altitude, and I could now take account of the fact by the way in which the land was disappearing under me. I now closed the valve to save my gas. There was nothing but to wait and see what would happen. The upward-rushing column of air continued to take me to a height of 3000 metres (almost 2 miles). I could do nothing but watch the barometer. Then, after what seemed a long time, it showed that I had begun descending. When I began to see land I threw out ballast, not to strike the earth too quickly. Now I could perceive the storm beating the trees and shrubbery. Up in the storm itself I had felt nothing. Now, too, as I continued falling lower, I could see how swiftly I was being carried laterally. By the time I perceived the coming danger I was in it. Carried along at a terrific rate, knocking against the tops of trees, and continually threatened with a painful death, I threw out my anchor. It caught in trees and shrubs and broke away. Had it been heavy timber all would have been over with me. As it chanced, I was dragged through the small trees and yielding shrubbery, my face a mass of cuts and bruises, my clothes torn from my back, in pain and strain, fearing the worst, and able to do nothing to save myself. Just as I had given myself up for lost the guide rope wound itself around a tree and held. I was precipitated from the basket, and fell unconscious. When I came to I had to walk some distance until I met some peasants. They helped me back to Nice, where I went to bed, and had the doctors sew me up. During the early period when I was glad to make public ascents for my balloon constructor I had undergone a somewhat similar experience, and that by night. The ascent took place at Péronne, in the north of France, one stormy afternoon, quite late. Indeed, I started in spite of thunder threatening in the distance, a gloomy semi-twilight all around me, and the remonstrances of the public, among whom it was known that I was not an aeronaut by trade. They feared my inexperience, and wished me either to renounce the ascent or else to oblige me to take up the balloon constructor with me, he being the responsible organiser of the _fête_. I would listen to nothing, and started off as I had planned. Soon I had cause to regret my rashness. I was alone, lost in the clouds, amid flashes of lightning and claps of thunder, in the rapidly-approaching darkness of the night! On, on I went tearing in the blackness. I knew that I must be going with great speed, yet felt no motion. I heard and felt the storm. I formed a part of the storm. I felt myself in great danger, yet the danger was not tangible. With it there was a fierce kind of joy. What shall I say? How shall I describe it? Up there in the black solitude, amid the lightning flashes and the thunderclaps, I was a part of the storm. When I landed the next morning--long after I had sought a higher altitude and let the storm pass on beneath me--I found that I was well into Belgium. The dawn was peaceful, so that my landing took place without difficulty. I mention this adventure because it was made account of in the papers of the time, and to show that night ballooning, even in a storm, may be more dangerous in appearance than reality. Indeed, night ballooning has a charm that is all its own. One is alone in the black void--true, in a murky limbo, where one seems to float without weight, without a surrounding world--a soul freed from the weight of matter. Yet now and again there are the lights of earth to cheer one. We see a point of light far on ahead. Slowly it expands. Then where there was one blaze there are countless bright spots. They run in lines, with here and there a brighter cluster. We know that it is a city. Then, again, it is out into the lone land, with only a faint glow here and there. When the moon rises we see, perhaps, a faint curling line of grey. It is a river, with the moonlight falling on its waters. There is a flash upward and a faint roar. It is a railway train, the locomotive's fires, maybe, illuminating for a moment its smoke as it rises. Then for safety we throw out more ballast, and rise through the black solitudes of the clouds into a soul-lifting burst of splendid starlight. There, alone with the constellations, we await the dawn. And when the dawn comes, red and gold and purple in its glory, one is almost loth to seek the earth again, although the novelty of landing in who knows what part of Europe affords still another unique pleasure. For many the great charm of all ballooning lies here. The balloonist becomes an explorer. Say that you are a young man who would roam, who would enjoy adventures, who would penetrate the unknown and deal with the unexpected--but say that you are tied down at home by family and business. I advise you to take to spherical ballooning. At noon you lunch peaceably amid your family. At 2 P.M. you mount. Ten minutes later you are no longer a commonplace citizen--you are an explorer, an adventurer of the unknown as truly as they who freeze on Greenland's icy mountains or melt on India's coral strand. You know but vaguely where you are and cannot know where you are going. Yet much may depend upon your choice as well as your skill and experience. The choice of altitude is yours--whether to accept this current or mount higher and go with another. You may mount above the clouds, where one breathes oxygen from tubes, while the earth, in the last glimpse you had of it, seems to spin beneath you, and you lose all bearings; or you may descend and scud along the surface, aided by your guide rope and a dipperful of ballast to leap over trees and houses--giant leaps made without effort. Then when the time comes to land there is the true explorer's zest of coming on unknown peoples like a god from a machine. "What country is this?" Will the answer come in German, Russian, or Norwegian? Paris Aéro Club members have been shot at when crossing European frontiers. Others, landing, have been taken prisoners to the burgomeister or the military governor, to languish as spies while the telegraph clicked to the far-off capital, and then to end the evening over champagne at an officers' enthusiastic mess. Still others have had to strive with the dangerous ignorance and superstition even of some remote little peasant population. These are the chances of the winds. [Illustration: MOTOR OF "No. 1"] CHAPTER VI I YIELD TO THE STEERABLE BALLOON IDEA During my ascent with M. Machuron, while our guide rope was wrapped around the tree and the wind was shaking us so outrageously, he improved the occasion to discourage me against all steerable ballooning. "Observe the treachery and vindictiveness of the wind," he cried between shocks. "We are tied to the tree, yet see with what force it tries to jerk us loose." (Here I was thrown again to the bottom of the basket.) "What screw propeller could hold a course against it? What elongated balloon would not double up and take you flying to destruction?" It was discouraging. Returning to Paris by rail I gave up the ambition to continue Giffard's trials, and this state of mind lasted with me for weeks. I would have argued fluently against the dirigibility of balloons. Then came a new period of temptation, for a long-cherished idea dies hard. When I took account of its practical difficulties I found my mind working automatically to convince itself that they were not. I caught myself saying: "If I make a cylindrical balloon long enough and thin enough it will cut the air ..." and, with respect to the wind, "shall I not be as a sailing yachtsman who is not criticised for refusing to go out in a squall?" At last an accident decided me. I have always been charmed by simplicity, while complications, be they never so ingenious, repel me. Automobile tricycle motors happened to be very much perfected at the moment. I delighted in their simplicity, and, illogically enough, their merits had the effect of deciding my mind against all other objections to steerable ballooning. "I will use this light and powerful motor," I said. "Giffard had no such opportunity." Giffard's primitive steam-engine, weak in proportion to its weight, spitting red-hot sparks from its coal fuel, had afforded that courageous innovator no fair chance, I argued. I did not dally a single moment with the idea of an electric motor, which promises little danger, it is true, but which has the capital ballooning defect of being the heaviest known engine, counting the weight of its battery. Indeed, I have so little patience with the idea that I shall say no more about it except to repeat what Mr Edison said to me on this head in April 1902: "You have done well," he said, "to choose the petroleum motor. It is the only one of which an aeronaut can dream in the present state of the industry; and steerable balloons with electric motors, especially as they were fifteen or twenty years ago, could have led to no result. That is why the Tissandier brothers gave them up." In spite of the recent immense improvements made in the steam-engine it would not have been able to decide me in favour of steerable ballooning. Motor for motor it is, perhaps, better than the petroleum motor, but when you compare the boiler with the carburator the latter weighs grammes per horse-power while the boiler weighs kilogrammes. In certain light steam-motors, that are lighter even than petroleum motors, the boiler always ruins the proportion. With one pound of petroleum you can exert one horse-power during one hour. To get this same energy from the most improved steam-engine you will want many kilogrammes of water and of fuel, be it petroleum or other. Even condensing the water, you cannot have less than several kilogrammes per horse-power. Then if one uses coal fuel with the steam-motor there are the burning sparks; while if one uses petroleum with burners you have a great amount of fire. We must do the petroleum motor the justice to admit that it makes neither flame nor burning sparks. At the present moment I have a Clement petroleum motor that weighs but 2 kilogrammes (4-1/2 lbs.) per horse-power. This is my 60 horse-power "No. 7," whose total weight is but 120 kilogrammes (264 lbs.). Compare this with the new steel-and-nickel battery of Mr Edison, which promises to weigh 18 kilogrammes (40 lbs.) per horse-power. The light weight and the simplicity of the little tricycle motor of 1897 are, therefore, responsible for all my trials. I started from this principle: To make any kind of success it would be necessary to economise weight, and so comply with the pecuniary, as well as the mechanical, conditions of the problem. Nowadays I build air-ships in a large way. I am in it as a kind of lifework. Then I was but a half-decided beginner, unwilling to spend large sums of money in a doubtful project. Therefore I resolved to build an elongated balloon just large enough to raise, along with my own 50 kilogrammes (110 lbs.) of weight, as much more as might be necessary for the basket and rigging, motor, fuel, and absolutely indispensable ballast. In reality I was building an air-ship to fit my little tricycle motor. I looked for the workshop of some small mechanic near my residence in the centre of residential Paris where I could have my plans executed under my own eyes and could apply my own hands to the task. I found such an one in the Rue du Colisée. There I first worked out a tandem of two cylinders of a tricycle motor--that is, their prolongation, one after the other, to work the same connecting-rod while fed by a single carburator. To bring everything down to a minimum weight, I cut out from every part of the motor whatever was not strictly necessary to solidity. In this way I realised something that was interesting in those days--a 3-1/2 horse-power motor that weighed 30 kilogrammes (66 lbs.). I soon had an opportunity to test my tandem motor. The great series of automobile road-races, which seems to have had its climax in Paris-Madrid in 1903, was raising the power of these wonderful engines by leaps and bounds year after year. Paris-Bordeaux in 1895 was won with a 4 horse-power machine at an average speed of 25 kilometres (15-1/2 miles) per hour. In 1896 Paris-Marseilles-and-return was accomplished at the rate of 30 kilometres (18-1/2 miles) per hour. Now, in 1897, it was Paris-Amsterdam. Although not entered for the race it occurred to me to try my tandem motor attached to its original tricycle. I started, and to my contentment found that I could keep well up with the pace. Indeed, I might have won a good place in the finish--my vehicle was the most powerful of the lot in proportion to its weight, and the average speed of the winner was only 40 kilometres (25 miles) per hour--had I not begun to fear that the jarring of my motor in so strenuous an effort might in the long run derange it, and I imagined I had more important work for it to do. For that matter, my automobiling experience has stood me in good stead with my air-ships. The petroleum motor is still a delicate and capricious thing, and there are sounds in its spitting rumble that are intelligible only to the long-experienced ear. Should the time come in some future flight of mine when the motor of my air-ship threatens danger I am convinced that my ear will hear, and I shall heed, the warning. This almost instinctive faculty I owe only to experience. Having broken up the tricycle for the sake of its motor I purchased at about this time an up-to-date 6 horse-power Panhard, with which I went from Paris to Nice in 54 hours--night and day, without stop--and had I not taken up dirigible ballooning I must have become a road-racing automobile enthusiast, continually exchanging one type for another, continually in search of greater speed, keeping pace with the progress of the industry, as so many others do, to the glory of French mechanics and the new Parisian sporting spirit. But my air-ships stopped me. While experimenting I was tied down to Paris. I could take no long trips, and the petroleum automobile, with its wonderful facility for finding fuel in every hamlet, lost its greatest use in my eyes. In 1898 I happened to see what was to me an unknown make of light American electric buggy. It appealed alike to my eye, my needs, and my reason, and I bought it. I have never had cause to regret the purchase. It serves me for running about Paris, and it goes lightly, noiselessly, and without odour. I had already handed the plan of my balloon envelope to the constructors. It was that of a cylindrical balloon terminating fore and aft in cones, 25 metres (82-1/2 feet) long, with a diameter of 3·5 metres (11-1/2 feet) and a gas capacity of 180 cubic metres (6354 cubic feet). My calculations had left me only 30 kilogrammes (66 lbs.) for both the balloon material and its varnish. Therefore I gave up the usual network and _chemise_, or outer cover; indeed, I considered this second envelope, holding the balloon proper within it, to be not only superfluous but harmful, if not dangerous. Instead I attached the suspension cords of my basket directly to the balloon envelope by means of small wooden rods introduced into long horizontal hems sewed on both sides to its stuff for a great part of the balloon's length. Again, in order not to pass my 30 kilogrammes (66 lbs.), including varnish, I was obliged to have recourse to my Japanese silk, which had proved so staunch in the "Brazil." After glancing at this order for the balloon envelope M. Lachambre at first refused it plumply. He would not make himself a party to such rashness. But when I recalled to his memory how he had said the same thing with respect to the "Brazil," and went on to assure him that, if necessary, I would cut and sew the balloon with my own hands, he gave way to me and undertook the job. He would cut and sew and varnish the balloon according to my plans. The balloon envelope being thus put under way I prepared my basket, motor, propeller, rudder, and machinery. When they were completed I made many trials with them, suspending the whole system by a cord from the rafters of the workshop, starting the motor, and measuring the force of the forward swing caused by the propeller working on the atmosphere behind it. Holding back this forward movement by means of a horizontal rope attached to a dynamometer, I found that the traction power developed by the motor in my propeller with two arms, each measuring one metre across, was as high as 11·4 kilogrammes (25 lbs.). This was a figure that promised good speed to a cylindrical balloon of my dimensions, whose length was equal to nearly seven times its diameter. With 1200 turns to the minute the propeller, which was attached directly to the motor shaft, might easily, if all went well, give the air-ship a speed of not less than 8 metres (26-1/2 feet) per second. [Illustration: Fig. 3.] The rudder I made of silk, stretched over a triangular steel frame. There now remained nothing to devise but a system of shifting weights, which from the very first I saw would be indispensable. For this purpose I placed two bags of ballast, one fore and one aft, suspended from the balloon envelope by cords. By means of lighter cords each of these two weights could be drawn into the basket (see Fig. 3), thus shifting the centre of gravity of the whole system. Pulling in the fore weight would cause the stem of the balloon to point diagonally upward; pulling in the aft weight would have just the opposite effect. Besides these I had a guide rope some 60 metres (200 feet) long, which could also be used, at need, as shifting ballast. All this occupied several months, and the work was all carried on in the little machine-shop of the Rue du Colisée, only a few steps from the place where later the Paris Aéro Club was to have its first offices. CHAPTER VII MY FIRST AIR-SHIP CRUISES (1898) In the middle of September 1898 I was ready to begin in the open air. The rumour had spread among the aeronauts of Paris, who formed the nucleus of the Aéro Club, that I was going to carry up a petroleum motor in my basket. They were sincerely disquieted by what they called my temerity, and some of them made friendly efforts to show me the permanent danger of such a motor under a balloon filled with a highly inflammable gas. They begged me instead to use the electric motor--"which is infinitely less dangerous." I had arranged to inflate the balloon at the Jardin d'Acclimatation, where a captive balloon was already installed and furnished with everything needful daily. This gave me facilities for obtaining, at one franc per cubic metre, the 180 cubic metres (6354 cubic feet) of hydrogen which I needed. [Illustration: THE "SANTOS-DUMONT No. 1" FIRST START] On September 18th my first air-ship--the "Santos-Dumont No. 1," as it has since been called to distinguish it from those which followed--lay stretched out on the turf amid the trees of the beautiful Jardin d'Acclimatation, the new Zoological Garden of the west of Paris. To understand what happened I must explain the starting of spherical balloons from such places where groups of trees and other obstructions surround the open space. When the weighing and balancing of the balloon are finished and the aeronauts have taken their place in the basket the balloon is ready to quit the ground with a certain ascensional force. Thereupon aids carry it toward an extremity of the open space in the direction from which the wind happens to be blowing, and it is there that the order: "Let go all!" is given. In this way the balloon has the entire open space to cross before reaching the trees or other obstructions which may be opposite and toward which the wind would naturally carry it. So it has space and time to rise high enough to pass over them. Moreover, the ascensional force of the balloon is regulated accordingly: it is very little if the wind be light; it is more if the wind be stronger. I had thought that my air-ship would be able to go against the wind that was then blowing, therefore I had intended to place it for the start at precisely the other end of the open space from that which I have described--that is, down stream, and not up stream in the air current with relation to the open space surrounded by trees. I would thus move out of the open space without difficulty, having the wind against me--for under such conditions the relative speed of the air-ship ought to be the difference between its absolute speed and the velocity of the wind--and so by going against the air current I should have plenty of time to rise and pass over the trees. Evidently it would be a mistake to place the air-ship at a point suitable for an ordinary balloon without motor and propeller. And yet it was there that I did place it, not by my own will, but by the will of the professional aeronauts who came in the crowd to be present at my experiment. In vain I explained that by placing myself "up stream" in the wind with relation to the centre of the open space I should inevitably risk precipitating the air-ship against the trees before I would have time to rise above them, the speed of my propeller being superior to that of the wind then blowing. All was useless. The aeronauts had never seen a dirigible balloon start off. They could not admit of its starting under other conditions than those of a spherical balloon, in spite of the essential difference between the two. As I was alone against them all I had the weakness to yield. I started off from the spot they indicated, and within a second's time I tore my air-ship against the trees, as I had feared I should do. After this deny if you can the existence of a fulcrum in the air. This accident at least served to show the effectiveness of my motor and propeller in the air to those who doubted it before. I did not waste time in regrets. Two days later, on September 20th, I actually started from the same open space, this time choosing my own starting-point. I passed over the tops of the trees without mishap, and at once began sailing around them, to give on the spot a first demonstration of the air-ship to the great crowd of Parisians that had assembled. I had their sympathy and applause then, as I have ever had it since; the Parisian public has always been a kind and enthusiastic witness of my efforts. Under the combined action of the propeller impulse, of the steering rudder, of the displacement of the guide rope, and of the two sacks of ballast sliding backward and forward as I willed, I had the satisfaction of making my evolutions in every direction--to right and left, and up and down. Such a result encouraged me, and, being inexperienced, I made the great mistake of mounting high in the air to 400 metres (1300 feet), an altitude that is considered nothing for a spherical balloon, but which is absurd and uselessly dangerous for an air-ship under trial. At this height I commanded a view of all the monuments of Paris. I continued my evolutions in the direction of the Longchamps racecourse, which from that day I chose for the scene of my aerial experiments. So long as I continued to ascend the hydrogen increased in volume as a consequence of the atmospheric depression. So by its tension the balloon was kept taut, and everything went well. It was not the same when I began descending. The air pump, which was intended to compensate the contraction of the hydrogen, was of insufficient capacity. The balloon, a long cylinder, all at once began to fold in the middle like a pocket knife, the tension of the cords became unequal, and the balloon envelope was on the point of being torn by them. At that moment I thought that all was over, the more so as the descent, which had begun, could no longer be checked by any of the usual means on board, where nothing worked. The descent became a fall. Luckily, I was falling in the neighbourhood of the grassy turf of Bagatelle, where some big boys were flying kites. A sudden idea struck me. I cried to them to grasp the end of my guide rope, which had already touched the ground, and to run as fast as they could with it _against the wind_. They were bright young fellows, and they grasped the idea and the rope at the same lucky instant. The effect of this help _in extremis_ was immediate, and such as I had hoped. By the manoeuvre we lessened the velocity of the fall, and so avoided what would have otherwise have been a bad shaking-up, to say the least. I was saved for the first time. Thanking the brave boys, who continued aiding me to pack everything into the air-ship's basket, I finally secured a cab and took the relics back to Paris. CHAPTER VIII HOW IT FEELS TO NAVIGATE THE AIR Notwithstanding the breakdown I felt nothing but elation that night. The sentiment of success filled me: I had navigated the air. I had performed every evolution prescribed by the problem. _The breakdown itself had not been due to any cause foreseen by the professional aeronauts._ I had mounted without sacrificing ballast. I had descended without sacrificing gas. My shifting weights had proved successful, and it would have been impossible not to recognise the capital triumph of these oblique flights through the air. No one had ever made them before. Of course, when starting, or shortly after leaving the ground, one has sometimes to throw out ballast to balance the machine, as one may have made a mistake and started with the air-ship far too heavy. What I have referred to are manoeuvres in the air. [Illustration: "No. 4" FREE DIAGONAL MOVEMENT UP] [Illustration: "No. 6." FREE DIAGONAL MOVEMENT DOWN] My first impression of aerial navigation was, I confess, surprise to feel the air-ship going straight ahead. It was astonishing to feel the wind in my face. In spherical ballooning we go with the wind, and do not feel it. True, in rising and descending the spherical balloonist feels the friction of the atmosphere, and the vertical oscillation makes the flag flutter, but in the horizontal movement the ordinary balloon seems to stand still, while the earth flies past under it. As my air-ship ploughed ahead the wind struck my face and fluttered my coat, as on the deck of a transatlantic liner, though in other respects it will be more accurate to liken aerial to river navigation with a steamboat. It is not like sail navigation, and all talk about "tacking" is meaningless. If there is any wind at all it is in a given direction, so that the analogy with a river current is complete. When there is no wind at all we may liken it to the navigation of a smooth lake or pond. It will be well to understand this matter. Suppose that my motor and propeller push me through the air at the rate of 20 miles an hour, I am in the position of a steamboat captain whose propeller is driving him up or down the river at the rate of 20 miles an hour. Imagine the current to be 10 miles per hour. If he navigates against the current he accomplishes 10 miles an hour with respect to the shore, though he has been travelling at the rate of 20 miles an hour through the water. If he goes with the current he accomplishes 30 miles an hour with respect to the shore, though he has not been going any faster through the water. This is one of the reasons why it is so difficult to estimate the speed of an air-ship. It is also the reason why air-ship captains will always prefer to navigate for their own pleasure in calm weather, and, when they find an air current against them, will steer obliquely upward or downward to get out of it. Birds do the same thing. The sailing yachtsman whistles for a fair breeze, without which he can do nothing, but the river steamboat captain will always hug the shore to avoid the freshet, and will time his descent of the river by the outgoing, rather than the incoming, tide. We air-shipmen are steamboat captains and not sailing yachtsmen. The navigator of the air, however, has the one great advantage--he can leave one current for another. The air is full of varying currents. Mounting, he will find an advantageous breeze or else a calm. These are strictly practical considerations, having nothing to do with the air-ship's ability to battle with the breeze when obliged to do it. Before going on my first trip I had wondered if I should be sea-sick. I foresaw that the sensation of mounting and descending obliquely with my shifting weights might be unpleasant. And I looked forward to a good deal of pitching (_tangage_), as they say on board ship--of rolling there would not be so much--but both sensations would be novel in ballooning, for the spherical balloon gives no sensation of movement at all. In my first air-ship, however, the suspension was very long, approximating that of a spherical balloon. For this reason there was very little pitching. And, speaking generally, since that time, though I have been told that on this or that trip my air-ship pitched considerably, I have never been sea-sick. It may be due in part to the fact that I am rarely subject to this ill upon the water. Back and forth between Brazil and France and between France and the United States I have had experience of all kinds of weather. Once, on the way to Brazil, the storm was so violent that the grand piano went loose and broke a lady's leg, yet I was not sea-sick. I know that what one feels most distressingly at sea is not so much the movement as that momentary hesitation just before the boat pitches, followed by the malicious dipping or mounting, which never comes quite the same, and the shock at top and bottom. All this is powerfully aided by the smells of the paint, varnish, tar, mingled with the odours of the kitchen, the heat of the boilers, and the stench of the smoke and the hold. In the air-ship there is no smell--all is pure and clean--and the pitching itself has none of the shocks and hesitations of the boat at sea. The movement is suave and flowing, which is doubtless owing to the lesser resistance of the air waves. The pitches are less frequent and rapid than those at sea; the dip is not brusquely arrested, so that the mind can anticipate the curve to its end; and there is no shock to give that queer, "empty" sensation to the solar plexus. Furthermore, the shocks of a transatlantic liner are due first to the fore, and then to the after, part of the giant construction rising out of the water to plunge into it again. The air-ship never leaves its medium--the air--in which it only swings. This consideration brings me to the most remarkable of all the sensations of aerial navigation. On my first trip it actually shocked me! This is the utterly new sensation of movement in an extra dimension! Man has never known anything like free vertical existence. Held to the plane of the earth, his movement "down" has scarcely been more than to return to it after a short excursion "up," our minds remaining always on the plane surface even while our bodies may be mounting; and this is so much the case that the spherical balloonist as he rises has no sense of movement, but gains the impression that the earth is descending below him. _With respect to combinations of vertical and horizontal movements, man is absolutely without experience of them._ Therefore, as all our sensations of movement are practically in two dimensions, this is the extraordinary novelty of aerial navigation that it affords us experiences--not in the fourth dimension, it is true--but in what is practically an extra dimension--the third--so that the miracle is similar. Indeed, I cannot describe the delight, the wonder, and intoxication of this free diagonal movement onward and upward or onward and downward, combined at will with brusque changes of direction horizontally when the air-ship answers to a touch of the rudder! The birds have this sensation when they spread their great wings and go tobogganning in curves and spirals through the sky! Por mares nunca d'antes navegados! (O'er seas hereto unsailed.) The line of our great poet echoed in my memory from childhood. After this first of all my cruises I had it put on my flag. It is true that spherical ballooning had prepared me for the mere sensation of height; but that is a very different matter. It is, therefore, curious that, prepared on this head as I was, the mere thought of height should have given me my only unpleasant experience. What I mean is this: The wonderful new combinations of vertical and horizontal movements, utterly out of previous human experience, caused me neither surprise nor trouble. I would find myself ploughing diagonally upward through the air with a kind of instinctive liberty. And yet when moving horizontally--as you would say, in the natural position--a glance downwards at the house-tops disquieted me. [Illustration: THE HOUSETOPS LOOK SO DANGEROUS] "What if I should fall?" the thought came. The house-tops looked so dangerous with their chimney-pots for spikes. One seldom has this thought in a spherical balloon, because we know that the danger in the air is _nil_: the great spherical balloon can neither suddenly lose its gas nor burst. My little air-ship balloon had to support not only exterior but interior pressure as well--which is not the case with a spherical balloon, as I shall explain in the next chapter--and any injury to the cylindrical form of my air-ship balloon by loss of gas might prove fatal. While over the house-tops I felt that it would be bad to fall, but as soon as I left Paris and was navigating over the forest of the Bois de Boulogne the idea left me entirely. Below there seemed to be an ocean of greenery, soft and safe. It was while over the continuation of this greenery in the grassy _pelouse_ of the Longchamps racecourse that my balloon, having lost a great deal of its gas, began to double on itself. Previously I had heard a noise. Looking up, I saw that the long cylinder of the balloon was beginning to break. Then I was astonished and troubled. I wondered what I could do. I could not think of anything to do. I might throw out ballast. That would cause the air-ship to rise, and the decreased pressure of the atmosphere would doubtless permit the expanding gas to straighten out the balloon again taut and strong. But I remembered that I must always come down again when all the danger would repeat itself, and worse even than before, from the more gas I should have lost. There was nothing to do but to go on down instantly. I remember having the sure idea: "If that balloon cylinder doubles any more, the ropes by which I am suspended to it will work at different strengths and will begin to break one by one as I go down!" For the moment I was sure that I was in the presence of death. Well, I will tell it frankly, my sentiment was almost entirely that of waiting and expectation. "What is coming next?" I thought. "What am I going to see and know in a few minutes? Whom shall I see after I am dead?" [Illustration: OVER THE BOIS DE BOULOGNE. BELOW THERE SEEMED TO BE AN OCEAN OF GREENERY, SOFT AND SAFE] The thought that I should be meeting my father in a few minutes thrilled me. Indeed, I think that in such moments there is no room either for regret or terror. The mind is too full of looking forward. One is frightened only so long as one still has a chance. CHAPTER IX EXPLOSIVE ENGINES AND INFLAMMABLE GASES I have been so often and so sincerely warned against what is taken for granted to be the patent danger of operating explosive engines under masses of inflammable gases that I may be pardoned for stopping a moment to disclaim undue or thoughtless rashness. Very naturally, from the first, the question of physical danger to myself called for consideration. I was the interested party, and I tried to view the question from all points. Well, the outcome of these meditations was to make me fear fire very little, while doubting other possibilities against which no one ever dreamed of warning me. [Illustration: THE QUESTION OF PHYSICAL DANGER] I remember that while working on the first of all my air-ships in that little carpenter shop of the Rue du Colisée I used to wonder how the vibrations of the petroleum motor would affect the system when it got in the air. In those days we did not have the noiseless automobiles, free from great vibration, of the present. Nowadays, even the colossal 80 and 90 horse-power motors of the latest racing types can be started and stopped as gently as those great steel hammers in iron foundries, whose engineers make a trick of cracking the top of an egg with them without breaking the rest of the shell. My tandem motor of two cylinders, working the same connecting-rod and fed by a single carburator, realised 3-1/2 horse-power--at that time a considerable force for its weight--and I had no idea how it would act off terra firma. I had seen motors "jump" along the highway. What would mine do in its little basket, that weighed almost nothing, and suspended from a balloon that weighed less than nothing? You know the principle of these motors? One may say that there is gasoline in a receptacle. Air passing through it comes out mixed with gasoline gas, ready to explode. You give a whirl to a crank, and the thing begins working automatically. The piston goes down, sucking combined gas and air into the cylinder. Then the piston comes back and compresses it. At that moment an electric spark is struck. An explosion follows instantly; and the piston goes down, producing work. Then it goes up, throwing out the product of combustion. Thus with the two cylinders there was one explosion for every turn of the shaft. Wishing to have my mind clear on the question I took my tricycle, just as it was after I had left the Paris-Amsterdam race, and, accompanied by a capable companion, I steered it to a lonely part of the Bois de Boulogne. There in the forest I chose a great tree with low-hanging limbs. From two of them we suspended the motor tricycle by three ropes. When we had well established the suspension my companion aided me to climb up and seat myself on the tricycle saddle. I was as in a swing. In a moment I would start the motor and learn something of my future success or failure. Would the vibration of the explosive engine shake me back and forth, strain at the ropes until it had unequalised their tension, and then break them one by one? Would it jar the interior air balloon's pump and derange the big balloon's valves? Would it continually jerk and pull at the silk hems and the thin rods which were to hold my basket to the balloon? Free from the steadying influence of the solid ground, would the jumping motor jar itself until it broke? And, breaking, might it not explode? All this and more had been predicted by the professional aeronauts, and I had as yet no proof outside of reasoning that they might not be right on this or that topic. I started the motor. I felt no particular vibration, and I was certainly not being shaken. I increased the speed, and felt _less_ vibration! There could be no doubt about it--there was less vibration in this light-weight tricycle hanging in the air than I had regularly felt while travelling on the ground. It was my first triumph in the air! I will say frankly that as I rose in the air on my first trip I had no fear of fire. What I feared was that the balloon might burst by reason of its interior pressure. I still fear it. Before going up I had minutely tried the valves. I still try them minutely before each of my trips. The danger, of course, was that the valves might not work adequately, in which case the expanding of the gas as the balloon rose would cause the dreaded explosion. Here is the great difference between spherical and dirigible balloons. The spherical balloon is always open. When it is taut with gas it is shaped like an apple; when it has lost part of its gas it takes the shape of a pear; but in each case there is a great hole in the bottom of the spherical balloon where the stem of the apple or the pear would be, and it is through this hole that the gas has opportunity to ease itself in the constant alternations of condensation and dilatation. Having such a free vent, the spherical balloon runs no risk of bursting in the air; but the price paid for this immunity is great loss of gas and, consequently, a fatal shortening of the spherical balloon's stay in the air. Some day a spherical balloonist will close up that hole; indeed, they already talk of doing it. I was obliged to do it in my air-ship balloon, whose cylindrical form must be preserved at all cost. For me there must be no transformations as from apple to pear. Interior pressure only could guarantee me this. The valves to which I refer have since my first experiments been of all kinds--some very ingeniously interacting, others of extreme simplicity. But their object in each case has always been the same: to hold the gas tight in the balloon up to a certain pressure and then let only enough out to relieve dangerous interior pressure. It is easy to realise, therefore, that should these valves refuse to act adequately the danger of bursting would be there. This possible danger I acknowledged to myself, but it had nothing to do with fire from the explosive motor. Yet during all my preparations, and up to the moment of calling: "Let go all!" the professional aeronauts, completely overlooking this weak point of the air-ship, continued to warn me against fire, of which I had no fear at all! "Do we dare strike matches in the basket of a spherical balloon?" they asked. "Do we even permit ourselves the solace of a cigarette on trips that last for many hours?" To me the cases did not seem the same. In the first place, why should one not light a match in the basket of a spherical balloon? If it be only because the mind vaguely connects the ideas of gas and flame the danger remains as ideal. If it be because of a real possibility of igniting gas that has escaped from the free hole in the stem of the spherical balloon it would not apply to me. My balloon, hermetically closed, except when excessive pressure should let either air or a very little gas escape through one of the automatic valves, might for a moment leave a little trail of gas _behind_ it as it moved on horizontally or diagonally, but there would be none in front where the motor was. (See Fig. 4.) [Illustration: Fig. 4] In this first air-ship I had placed the gas escape valves even farther from the motor than I place them to-day. The suspension cords being very long I hung in my basket far below the balloon. Therefore I asked myself: "How could this motor, so far below the balloon, and so far in front of its escape valves, set fire to the gas enclosed in it when such gas is not inflammable until mixed with air?" On this first trial, as in most since, I used hydrogen gas. Undoubtedly when mixed with air it is tremendously inflammable--but it must first mix with air. All my little balloon models are kept filled with hydrogen, and, so filled, I have more than once amused myself by burning _inside them_, not their hydrogen, but its mixture with the oxygen of the atmosphere. All one has to do is to insert in the balloon model a little tube to furnish a jet of the room's atmosphere from an air pump and light it with the electric spark. Similarly, should a pin-prick have made ever so slight a vent in my air-ship balloon, the interior pressure would have sent out into the atmosphere a long thin stream of hydrogen that _might_ have ignited had there been any flame near enough to do it. But there was none. This was the problem. My motor did undoubtedly send out flames for, say, half-a-yard round about it. They were, however, mere flames, not still-burning products of incomplete combustion like the sparks of a coal-burning steam-engine. This admitted, how was the fact that I had a mass of hydrogen unmixed with air and well secured in a tight envelope so high above the motor to prove dangerous? Turning the matter over and over in my mind I could see but one dangerous possibility from fire. This was the possibility of the petroleum reservoir itself taking fire by a _retour de flamme_ from the motor. During five years, I may here say in passing, I enjoyed complete immunity from the _retour de flamme_ (sucking back of the flame). Then, in the same week in which Mr Vanderbilt burned himself so severely, 6th July 1903, the same accident overtook me in my little "No. 9" runabout air-ship just as I was crossing the Seine to land on the Ile de Puteaux. I promptly extinguished the flame with my Panama hat ... without other incident. [Illustration: "No. 9" CATCHES FIRE OVER THE ILE DE PUTEAUX] For reasons like these I went up on my first air-ship trip without fear of fire, but not without doubt of a possible explosion due to insufficient working of my balloon's escape valves. Should such a "cold" explosion occur, the flame-spitting motor would probably ignite the mass of mixed hydrogen and air that would surround me; but it would have no decisive influence on the result. The "cold" explosion itself would doubtless be sufficient.... Now, after five years of experience, and in spite of the _retour de flamme_ above the Ile de Puteaux, I continue to regard the danger from fire as practically _nil_; but the possibility of a "cold" explosion remains always with me, and I must continue to purchase immunity from it at the cost of vigilant attention to my gas escape valves. Indeed, the possibility of the thing is greater technically now than in the early days which I describe. My first air-ship was not built for speed--consequently, it needed very little interior pressure to preserve the shape of its balloon. Now that I have great speed, as in my "No. 7," I must have enormous interior pressure to withstand the exterior pressure of the atmosphere in front of the balloon as I drive against it. CHAPTER X I GO IN FOR AIRSHIP BUILDING In the early spring of 1899 I built another air-ship, which the Paris public at once called "The Santos-Dumont No. 2." It had the same length and, at first sight, the same form as the "No. 1"; but its greater diameter brought its volume up to 200 cubic metres--over 7000 cubic feet--and gave me 20 kilogrammes (44 lbs.) more ascensional force. I had taken account of the insufficiency of the air pump that had all but killed me, and had added a little aluminium ventilator to make sure of permanency in the form of the balloon. [Illustration: ACCIDENT TO "No. 2," MAY 11, 1899 (FIRST PHASE)] This ventilator was a rotary fan, worked by the motor, to send air into the little interior air balloon, which was sewed inside to the bottom of the great balloon like a kind of closed pocket. In Fig. 5, _G_ is the great balloon filled with hydrogen gas, _A_ the interior air balloon, _VV_ the automatic gas valves, _AV_ the latter's air valve, and _TV_ the tube by which the rotary ventilator fed the interior air balloon. [Illustration: Fig. 5] The air valve _AV_ was an exhaust valve similar to the two gas valves _VV_ in the great balloon, with the one exception that it was weaker. In this way, when there happened to be too much fluid (_i.e._ gas or air, or both) distending the great balloon, all the air would leave the interior balloon before any of the gas would leave the great balloon. The first trial of my "No. 2" was set for 11th May 1899. Unfortunately, the weather, which had been fine in the morning, grew steadily rainy in the afternoon. In those days I had no balloon house of my own. All the morning the balloon had been slowly filling with hydrogen gas at the captive balloon station of the Jardin d'Acclimatation. As there was no shed there for me the work had to be done in the open, and it was done vexatiously, with a hundred delays, surprises, and excuses. When the rain came on, it wetted the balloon. What was to be done? I must either empty it and lose the hydrogen and all my time and trouble, or go on under the disadvantage of a rain-soaked balloon envelope, heavier than it ought to be. I chose to go up in the rain. No sooner had I risen than the weather caused a great contraction of the hydrogen, so that the long cylindrical balloon shrunk visibly. Then before the air pump could remedy the fault, a strong wind gust of the rainstorm doubled it up worse than the "No. 1," and tossed it into the neighbouring trees. My friends began at me again, saying: "This time you have learned your lesson. You must understand that it is impossible to keep the shape of your cylindrical balloon rigid. You must not again risk your life by taking a petroleum motor up beneath it." I said to myself: "What has the rigidity of the balloon's form to do with danger from a petroleum motor? Errors do not count. I have learned my lesson, but it is not that lesson." [Illustration: ACCIDENT TO "No. 2," MAY 11, 1899 (SECOND PHASE)] Accordingly I immediately set to work on a "No. 3," with a shorter and very much thicker balloon, 20 metres (66 feet) long and 7·50 metres (25 feet) at its greatest diameter (Fig. 6). Its much greater gas capacity--500 cubic metres (17,650 cubic feet)--would give it, with hydrogen, three times the lifting power of my first, and twice that of my second air-ship. This permitted me to use common illuminating gas, whose lifting power is about half that of hydrogen. The hydrogen plant of the Jardin d'Acclimatation had always served me badly. With illuminating gas I should be free to start from the establishment of my balloon constructor or elsewhere as I desired. [Illustration: Fig. 6] It will be seen that I was getting far away from the cylindrical shapes of my first two balloons. In the future I told myself that I would at least avoid doubling up. The rounder form of this balloon also made it possible to dispense with the interior air balloon and its feeding air pump that had twice refused to work adequately at the critical moment. Should this shorter and thicker balloon need aid to keep its form rigid I relied on the stiffening effect of a 10-metre (33-foot) bamboo pole (Fig. 6) fixed lengthwise to the suspension cords above my head and directly beneath the balloon. While not yet a true keel, this pole keel supported basket and guide rope and brought my shifting weights into much more effectual play. On November 13th, 1899, I started in the "Santos-Dumont No. 3," from the establishment of Vaugirard, on the most successful flight that I had yet made. [Illustration: ACCIDENT TO "No. 2," MAY 11, 1899 (THIRD PHASE)] From Vaugirard I went directly to the Champ de Mars, which I had chosen for its clear, open space. There I was able to practise aerial navigation to my heart's content--circling, driving ahead in straight courses, forcing the air-ship diagonally onward and upward, and shooting diagonally downward, by propeller force, and thus acquiring mastery of my shifting weights. These, because of the greater distance they were now set apart at the extremities of the pole keel (Fig. 6), worked with an effectiveness that astonished even myself. This proved my greatest triumph, for it was already clear to me that the central truth of dirigible ballooning must be ever: "To descend without sacrificing gas and to mount without sacrificing ballast." During these first evolutions over the Champ de Mars I had no particular thought of the Eiffel Tower. At most it seemed a monument worth going round, and so I circled round it at a prudent distance again and again. Then--still without any dream of what the future had in store for me--I made a straight course for the Parc des Princes, _over almost the exact line that, two years later, was to mark the Deutsch prize route_. I steered to the Parc des Princes because it was another fine open space. Once there, however, I was loth to descend, so, making a hook, I navigated to the manoeuvre grounds of Bagatelle, where I finally landed, in souvenir of my fall of the year previous. It was almost at the exact spot where the kite-flying boys had pulled on my guide rope and saved me from a bad shaking-up. At this time, remember, neither the Aéro Club nor myself possessed a balloon park or shed from which to start and to which to return. On this trip I considered that had the air been calm my speed in relation to the ground would have been as much as 25 kilometres (15 miles) per hour. In other words, I went at that rate through the air, the wind being strong though not violent. Therefore, even had not sentimental reasons led me to land at Bagatelle, I should have hesitated to return _with the wind_ to the Vaugirard balloon house--itself of small size, and difficult of access, and surrounded by all the houses of a busy quarter. Landing in Paris, in general, is dangerous for any kind of balloon, amid chimney-pots that threaten to pierce its belly, and tiles that are always ready to be knocked down on the heads of passers-by. When in the future air-ships become as common as automobiles are at present, spacious public and private landing-stages will have to be built for them in every part of the capital. Already they have been foretold by Mr Wells in his strange book, "When the Sleeper Wakes." [Illustration: ACCIDENT TO "No. 2," MAY 11, 1899 (FINALE)] Considerations of this order made it desirable for me to have a plant of my own. I needed a building for the housing of my air-ship between trips. Heretofore I had emptied the balloon of all its gas at the end of each trip, as one is bound to do with spherical balloons. Now I saw very different possibilities for dirigibles. The significant thing was the fact that my "No. 3" had lost so little gas (or, perhaps, none at all) at the end of its first long trip that I could well have housed it overnight and gone out again in it the next day. I had no longer the slightest doubt of the success of my invention. I foresaw that I was going into air-ship construction as a sort of life work. I should need my own workshop, my own balloon house, hydrogen plant, and connection with the illuminating gas mains. The Aéro Club had just acquired some land on the newly-opened Côteaux de Longchamps at St Cloud, and I concluded to build on it a great shed, long and high enough to house my air-ship with its balloon fully inflated, and furnished with all the facilities mentioned. This aerodrome, which I built at my own expense, was 30 metres long (100 feet), 7 metres (25 feet) wide, and 11 metres (36 feet) high. Even here I had to contend with the conceit and prejudice of artisans which had already given me so much trouble at the Jardin d'Acclimatation. It was declared that the sliding doors of my aerodrome could not be made to slide on account of their great size. I had to insist. "Follow my directions," I said, "and do not concern yourselves with their practicability!" Although the men had named their own pay, it was a long time before I could get the better of this vainglorious stubbornness of theirs. When finished the doors worked, naturally. Three years later the aerodrome built for me by the Prince of Monaco on my plans had still greater sliding doors. While this first of my balloon houses was under construction, I made a number of other successful trips in the "No. 3," the last time losing my rudder and luckily landing on the plain at Ivry. I did not repair the "No. 3." Its balloon was too clumsy in form and its motor was too weak. I had now my own aerodrome and gas plant. I would build a new air-ship, and with it I would be able to experiment for longer periods and with more method. [Illustration: START OF "No. 3," NOVEMBER 13, 1899] CHAPTER XI THE EXPOSITION SUMMER The Exposition of 1900, with its learned congresses, was now approaching. Its International Congress of Aeronautics being set for the month of September I resolved that the new air-ship should be ready to be shown to it. This was my "No. 4," finished 1st August 1900, and by far the most familiar to the world at large of all my air-ships. This is due to the fact that when I won the Deutsch prize, nearly eighteen months later and in quite a different construction, the newspapers of the world came out with old cuts of this "No. 4," which they had kept on file. It was the air-ship with the bicycle saddle. In it the 10-metre (33-foot) bamboo pole of my "No. 3" came nearer to being a real keel in that it no longer hung above my head, but, amplified by vertical and horizontal cross pieces and a system of tightly-stretched cords, sustained within itself motor, propeller, and connecting machinery, petroleum reservoir, ballast, and navigator in a kind of spider web without a basket (see photograph, page 135). I was obliged to sit in the midst of the spider web below the balloon on the saddle of a bicycle frame which I had incorporated into it. Thus the absence of the traditional balloon basket appeared to leave me astride a pole in the midst of a confusion of ropes, tubes, and machinery. Nevertheless, the device was very handy, because round this bicycle frame I had united cords for controlling the shifting weights, for striking the motor's electric spark, for opening and shutting the balloon's valves, for turning on and off the water-ballast spigots and certain other functions of the air-ship. Under my feet I had the starting pedals of a new 7 horse-power petroleum motor, driving a propeller with two wings 4 metres (13 feet) across each. They were of silk, stretched over steel plates, and very strong. For steering, my hands reposed on the bicycle handle-bars connected with my rudder. [Illustration: "SANTOS-DUMONT No. 4"] Above all this there stretched the balloon, 39 metres (129 feet) long, with a middle diameter of 5·10 metres (17 feet) and a gas capacity of 420 cubic metres (nearly 15,000 cubic feet). In form it was a compromise between the slender cylinders of my first constructions and the clumsy compactness of the "No. 3." (See Fig. 7.) For this reason I thought it prudent to give it an interior compensating air balloon fed by a rotary ventilator like that of the "No. 2," and as the balloon was smaller than its predecessor I was obliged to return again to hydrogen to get sufficient lifting power. For that matter, there was no longer any reason why I should not employ hydrogen. I now had my own hydrogen gas generator, and my "No. 4," safely housed in the aerodrome, might be kept inflated during weeks. [Illustration: Fig. 7] In the "Santos-Dumont, No. 4," I also tried the experiment of placing the propeller at the stem instead of the stern of the air-ship. So, attached to the pole keel in front, the screw pulled, instead of pushing it through the air. The new 7 horse-power motor with two cylinders turned it with a velocity of 100 revolutions per minute, and produced, from a fixed point, a traction effort of some 30 kilogrammes (66 lbs.). The pole keel with its cross pieces, bicycle frame, and mechanism weighed heavy. Therefore, although the balloon was filled with hydrogen, I could not take up more than 50 kilogrammes (110 lbs.) of ballast. I made almost daily experiments with this new air-ship during August and September 1900 at the Aéro Club's grounds at St Cloud, but my most memorable trial with it took place on 19th September in presence of the members of the International Congress of Aeronautics. Although an accident to my rudder at the last moment prevented me from making a free ascent before these men of science I, nevertheless, held my own against a very strong wind that was blowing at the time, and gave what they were good enough to proclaim a satisfying demonstration of the effectiveness of an aerial propeller driven by a petroleum motor. [Illustration: MOTOR OF "No. 4"] A distinguished member of the Congress, Professor Langley, desired to be present a few days later at one of my usual trials, and from him I received the heartiest kind of encouragement. The result of these trials was, nevertheless, to decide me to double the propeller's power by the adoption of the four-cylinder type of petroleum motor without water jacket--that is to say, the system of cooling _à ailettes_. The new motor was delivered to me very promptly, and I immediately set about adapting the air-ship to it. Its extra weight demanded either that I should construct a new balloon or else enlarge the old one. I tried the latter course. Cutting the balloon in half I had a piece put in it, as one puts a leaf in an extension table. This brought the balloon's length to 33 metres (109 feet). Then I found that the aerodrome was too short by 3 metres (10 feet) to receive it. In prevision of future needs I added 4 metres (13 feet) to its length. Motor, balloon, and shed were all transformed in fifteen days. The Exposition was still open, but the autumn rains had set in. After waiting, with the balloon filled with hydrogen, through two weeks of the worst possible weather I let out the gas and began experimenting with the motor and propeller. It was not lost time, for, bringing the speed of the propeller up to 140 revolutions per minute, I realised, from a fixed point, a traction effort of 55 kilogrammes (120 lbs.). Indeed, the propeller turned with such force that I took pneumonia in its current of cold air. I betook myself to Nice for the pneumonia, and there, while convalescing, an idea came to me. This new idea took the form of my first true air-ship keel. In a small carpenter shop at Nice I worked it out with my own hands--a long, triangular-sectioned pine framework of great lightness and rigidity. Though 18 metres (59-1/2 feet) in length it weighed only 41 kilogrammes (90 lbs.). Its joints were in aluminium, and, to secure its lightness and rigidity, to cause it to offer less resistance to the air and make it less subject to hygrometric variations, it occurred to me to reinforce it with tightly-drawn piano wires instead of cords. [Illustration: VISIT OF PROFESSOR LANGLEY] Then what turned out to be an utterly new idea in aeronautics followed. I asked myself why I should not use this same piano wire for all my dirigible balloon suspensions in place of the cords and ropes used in all kinds of balloons up to this time. I did it, and the innovation turned out to be peculiarly valuable. These piano wires, 8/10ths of a millimetre (0·032 inch) in diameter, possess a high coefficient of rupture and a surface so slight that their substitution for the ordinary cord suspensions constitutes a greater progress than many a more showy device. Indeed, it has been calculated that the cord suspensions offered almost as much resistance to the air as did the balloon itself. [Illustration: "No. 4." FLIGHT BEFORE PROFESSOR LANGLEY] At the stern of this air-ship keel I again established my propeller. I had found no advantage result from placing it in front of the "No. 4," where it was an actual hindrance to the free working of the guide rope. The propeller was now driven by a new 12 horse-power four-cylinder motor without water jacket, through the intermediary of a long, hollow steel shaft. Placing this motor in the centre of the keel I balanced its weight by taking my position in my basket well to the front, while the guide rope hung suspended from a point still farther forward (Fig. 8). To it, some distance down its length, I fastened the end of a lighter cord run up to a pulley fixed in the after part of the keel, and thence to my basket, where I fastened it convenient to my hand. Thus I made the guide rope do the work of shifting weights. Imagine, for example, that going on a straight horizontal course (as in Fig. 8) I should desire to rise. I would have but to pull in the guide rope shifter. It would pull the guide rope itself back (Fig. 9), and thus shift back the centre of gravity of the whole system that much. The stem of the air-ship would rise (as in Fig. 9), and, consequently, my propeller force would push me up along the new diagonal line. [Illustration: Fig. 8] The rudder was fixed at the stern as usual, and water-ballast cylinders, accessory shifting weights, petroleum reservoir, and the other parts of the machinery, were disposed in the new keel, well balanced. For the first time in these experiments, as well as the first time in aeronautics, I used liquid ballast. Two brass reservoirs, very thin, and holding altogether 54 litres (12 gallons), were filled with water and fixed in the keel, as above stated, between motor and propeller, and their two spigots were so arranged that they could be opened and shut from my basket by means of two steel wires. [Illustration: Fig. 9] Before this new keel was fitted to the enlarged balloon of my "No. 5," and in acknowledgment of the work I had done in 1900, the Scientific Commission of the Paris Aéro Club had awarded me its Encouragement prize, founded by M. Deutsch (de la Meurthe), and consisting of the yearly interest on 100,000 francs. To induce others to follow up the difficult and expensive problem of dirigible ballooning I left this 4000 francs at the disposition of the Aéro Club to found a new prize. I made the conditions of winning it very simple: "The Santos-Dumont prize shall be awarded to the aeronaut, a member of the Paris Aéro Club, and not the founder of this prize, who between 1st May and 1st October 1901, starting from the Parc d'Aerostation of St Cloud, shall turn round the Eiffel Tower and come back to the starting-point, at the end of whatever time, without having touched ground, and by his self-contained means on board alone. "If the Santos-Dumont prize is not won in 1901 it shall remain open the following year, always from 1st May to 1st October, and so on, until it be won." The Aéro Club signified the importance of such a trial by deciding to give its highest reward, a gold medal, to the winner of the Santos-Dumont prize, as may be seen by its minutes of the time. Since then the 4000 francs have remained in the treasury of the Club. [Illustration: "SANTOS-DUMONT No. 5"] CHAPTER XII THE DEUTSCH PRIZE AND ITS PROBLEMS This brings me to the Deutsch prize of aerial navigation, offered in the spring of 1900, while I was navigating my "No. 3," and after I had on at least one occasion--all unknowing--steered over what was to be its exact course from the Eiffel Tower to the Seine at Bagatelle (see page 127). This prize of 100,000 francs, founded by M. Deutsch (de la Meurthe), a member of the Paris Aéro Club, was to be awarded by the Scientific Commission of that organisation to the first dirigible balloon or air-ship that between 1st May and 1st October 1900, 1901, 1902, 1903, and 1904 should rise from the Parc d'Aerostation of the Aéro Club at St Cloud and, without touching ground and by its own self-contained means on board alone, describe a closed curve in such a way that the axis of the Eiffel Tower should be within the interior of the circuit, and return to the point of departure in the maximum time of half-an-hour. Should more than one accomplish the task in the same year the 100,000 francs were to be divided in proportion to the respective times. The Aéro Club's Scientific Commission had been named expressly for the purpose of formulating these and such other conditions of the foundation as it might deem proper, and by reason of certain of them I had made no attempt to win the prize with my "Santos-Dumont, No. 4." The course from the Aéro Club's Parc d'Aerostation to the Eiffel Tower and return was 11 kilometres (nearly 7 miles), and this distance, _plus the turning round the Tower_, must be accomplished in thirty minutes. This meant in a perfect calm a necessary speed of 25 kilometres (15-1/2 miles) per hour for the straight stretches--a speed I could not be sure to maintain all the way in my "No. 4." Another condition formulated by the Scientific Commission was that its members, who were to be the judges of all trials, must be notified twenty-four hours in advance of each attempt. Naturally, the operation of such a condition would be to nullify as much as possible all minute time calculations based either on a given rate of speed through perfect calm or such air current as might be prevailing twenty-four hours previous to the hour of trial. Though Paris is situated in a basin, surrounded on all sides by hills, its air currents are peculiarly variable, and brusque meteorological changes are extremely common. I foresaw also that when a competitor had once committed the formal act of assembling a Scientific Commission on a slope of the River Seine so far away from Paris as St Cloud he would be under a kind of moral pressure to go on with his trial, no matter how the air currents might have increased, and no matter in what kind of weather--wet, dry, or simply humid--he might find himself. Again, this moral pressure to go on with the trial against the aeronaut's better judgment must extend even to the event of an unlucky change in the state of the air-ship itself. One does not convoke a body of prominent personages to a distant riverside for nothing, yet in the twenty-four hours between notification and trial even a well-watched elongated balloon might well lose a little of its tautness unperceived. A previous day's preliminary trial might easily derange so uncertain an engine as the petroleum motor of the year 1900. And, finally, I saw that the competitor would be barred by common courtesy from convoking the Commission at the very hour most favourable for dirigible balloon experiments over Paris--the calm of the dawn. The duellist may call out his friends at that sacred hour, but not the air-ship captain. In founding the Santos-Dumont prize with the 4000 francs awarded to me by the Aéro Club for my work in the year 1900 it will be observed that I made no such conditions by the way. I did not wish to complicate the trial by imposing a minimum velocity, the check of a special committee, or any limitation of time of trial during the day. I was sure that even under the widest conditions it would be a great deal to come back to the starting-point after having reached a post publicly pointed out in advance--a thing that was unheard of before the year 1901. The conditions of the Santos-Dumont prize, therefore, left competitors free to choose the state of the air least unfavourable to them, as the calm of late evening or early morning. Nor would I inflict on them the possible surprises of a period of waiting between the convocation and the meeting of a Scientific Commission, itself in my eyes quite unnecessary in these days, when the army of newspaper reporters of a great capital is always ready to mobilise without notice, at any hour and spot, on the bare prospect of news. The newspaper men of Paris would be my Scientific Commission. [Illustration: "No. 5." LEAVING AËRO CLUB GROUNDS, JULY 12, 1901] As I had excluded myself from trying for the Santos-Dumont prize I naturally wished to show that it would not be impossible to fulfil its conditions. My "No. 5"--composed of the enlarged balloon of the "No. 4" and the new keel, motor, and propeller already described--was now ready for trial. In it, on the first attempt, I fulfilled the conditions of my own prize foundation. This was on July 12th, 1901, after a practice flight the day before. At 4.30 A.M. I steered my air-ship from the park of the Aéro Club at St Cloud to the Longchamps racecourse. I did not at that moment take time to ask permission of the Jockey Club, which, however, a few days later placed that admirable open space at my disposition. Ten times in succession I made the circuit of Longchamps, stopping each time at a point designed beforehand. After these first evolutions, which altogether made up a distance of about 35 kilometres (22 miles), I set out for Puteaux, and after an excursion of about 3 kilometres (2 miles), done in nine minutes, I steered back again to Longchamps. I was by this time so well satisfied with the dirigibility of my "No. 5" that I began looking for the Eiffel Tower. It had disappeared in the mists of the morning, but its direction was well known to me, so I steered for it as well as I might. In ten minutes I had come within 200 metres (40 rods) of the Champ de Mars. At this moment one of the cords managing my rudder broke. It was absolutely necessary to repair it at once, and to repair it I must descend to earth. With perfect ease I pulled forward the guide rope, shifted my centre of gravity, and drove the air-ship diagonally downward, landing gently in the Trocadero Gardens. Good-natured workmen ran to me from all directions. Did I need anything? they asked. Yes; I needed a ladder. And in less time than it takes to write it a ladder was found and placed in position. While two of these discreet and intelligent volunteers held it I climbed some twenty rounds to its top, and was able to repair the damaged rudder connection. [Illustration: "No. 5." RETURNING FROM THE EIFFEL TOWER] I started off again, mounting diagonally to my chosen altitude, turned the Eiffel Tower in a wide curve, and returned to Longchamps in a straight course without further incident after a trip which, including the stop for repairs, had lasted one hour and six minutes. Then after a few minutes' conversation I took my flight back to the St Cloud Aerodrome, passing the Seine at an altitude of 200 metres (over 600 feet), and housing the still perfectly-inflated air-ship in its shed as though it were a simple automobile. CHAPTER XIII A FALL BEFORE A RISE My "No. 5" had proved itself so much more powerful than its predecessors that I now found courage to inscribe myself for the Deutsch prize competition. Having taken this decisive step I at once convoked the Scientific Commission of the Aéro Club for a trial in accordance with the regulations. The Commission assembled in the grounds of the Aéro Club at St Cloud on July 13th, 1901 at 6.30 A.M. At 6.41 I started off. I turned the Eiffel Tower in the tenth minute and came back against an unexpected head wind, reaching the timekeepers at St Cloud in the fortieth minute, at an altitude of 200 metres, and after a terrific struggle with the element. [Illustration: "No. 5." ACCIDENT IN THE PARK OF M. EDMOND DE ROTHSCHILD] Just at this moment my capricious motor stopped, and the air-ship, bereft of its power, was carried off, and fell on the tallest chestnut-tree in the park of M. Edmond de Rothschild. The inhabitants and servants of the villa, who came running, very naturally imagined that the air-ship must be wrecked and myself probably hurt. They were astonished to find me standing in my basket high up in the tree, while the propeller touched the ground. Considering the force with which the wind had blown when I was battling with it on the home stretch I was myself surprised to note how little the balloon was torn. Nevertheless, all its gas had left it. This happened very near the house of the Princess Isabel, Comtesse d'Eu, who, hearing of my plight, and learning that I must be occupied some time in disengaging the air-ship, sent a lunch to me up in my tree, with an invitation to come and tell her the story of my trip. When the story was finished the daughter of Dom Pedro said to me: "Your evolutions in the air make me think of the flight of our great birds of Brazil. I hope you will do as well with your propeller as they do with their wings, and that you will succeed for the glory of our common country." A few days later I received the following letter:-- "_1st August 1901._ "MONSIEUR SANTOS-DUMONT,--Here is a medal of St Benedict that protects against accidents. "Accept it, and wear it at your watch-chain, in your card-case, or at your neck. "I send it to you, thinking of your good mother, and praying God to help you always and to make you work for the glory of our country. (Signed) "ISABEL, COMTESSE D'EU." As the newspapers have often spoken of my "bracelet" I may say that the thin gold chain of which it consists is simply the means I have taken to wear this medal, which I prize. [Illustration: AN ACCIDENT] The air-ship, as a whole, was damaged very little, considering the force of the wind and the nature of the accident. When it was ready to be taken out again I nevertheless thought it prudent to make several trials with it over the grassy lawn of the Longchamps racecourse. One of these trials I will mention, because it gave me--something rare--a fairly accurate idea of the air-ship's speed in perfect calm. On this occasion Mr Maurice Farman followed me round the racecourse in his automobile at its second speed. His estimate was between 26 and 30 kilometres (16 and 18-1/2 miles) per hour with my guide rope dragging. Of course, when the guide rope drags it acts exactly like a brake. How much it holds one back depends upon the length that actually drags along the ground. Our calculation at the time was about 5 kilometres (3 miles) per hour, which would have brought my proper speed up to between 30 and 35 kilometres (18-1/2 and 21-1/2 miles) per hour. All this encouraged me to make another trial for the Deutsch prize. And now I come to a terrible day--8th August 1901. At 6.30 A.M., in presence of the Scientific Commission of the Aéro Club, I started again for the Eiffel Tower. I turned the Tower at the end of nine minutes and took my way back to St Cloud; but my balloon was losing hydrogen through one of its two automatic gas valves, whose spring had been accidentally weakened. I had perceived the beginning of this loss of gas even before reaching the Eiffel Tower, and ordinarily, in such an event, I should have come at once to earth to examine the lesion. But here I was competing for a prize of great honour, and my speed had been good. Therefore I risked going on. The balloon now shrunk visibly. By the time I had got back to the fortifications of Paris, near La Muette, it caused the suspension wires to sag so much that those nearest to the screw propeller caught in it as it revolved. I saw the propeller cutting and tearing at the wires. I stopped the motor instantly. Then, as a consequence, the air-ship was at once driven back toward the Tower by the wind, which was strong. At the same time I was falling. The balloon had lost much gas. I might have thrown out ballast and greatly diminished the fall, but then the wind would have time to blow me back on the Eiffel Tower. I, therefore, preferred to let the air-ship go down as it was going. It may have seemed a terrific fall to those who watched it from the ground, but to me the worst detail was the air-ship's lack of equilibrium. The half-empty balloon, fluttering its empty end as an elephant waves his trunk, caused the air-ship's stem to point upward at an alarming angle. What I most feared, therefore, was that the unequal strain on the suspension wires would break them one by one and so precipitate me to the ground. Why was the balloon fluttering an empty end and causing all this extra danger? How was it that the rotary ventilator was not fulfilling its purpose in feeding the interior air balloon and in this manner swelling out the gas balloon around it? The answer must be looked for in the nature of the accident. The rotary ventilator stopped working when the motor itself stopped, and I had been obliged to stop the motor to prevent the propeller from tearing the suspension wires near it when the balloon first began to sag from loss of gas. It is true that the ventilator, which was working at that moment, had not proved sufficient to prevent the first sagging. It may have been that the interior air balloon refused to fill out properly. The day after the accident, when my balloon constructor's man came to me for the plans of a "No. 6" balloon envelope, I gathered from something he said that the interior air balloon of the "No. 5," not having been given time for its varnish to dry before being adjusted, might have stuck together or stuck to the sides or bottom of the outer balloon. Such are the rewards of haste. I was falling. At the same time the wind was carrying me toward the Eiffel Tower. It had already carried me so far that I was expecting to land on the Seine embankment beyond the Trocadero. My basket and the whole of the keel had already passed the Trocadero hotels, and had my balloon been a spherical one, it too would have cleared the building. But now, at the last critical moment, the end of the long balloon that was still full of gas came slapping down on the roof just before clearing it. It exploded with a great noise--exactly like a paper bag struck after being blown up. This was the "terrific explosion" described in the newspapers of the day. I had made a mistake in my estimate of the wind's force by a few yards. Instead of being carried on to fall on the Seine embankment I now found myself hanging in my wicker basket high up in the courtyard of the Trocadero hotels, supported by my air-ship's keel, which stood braced at an angle of about 45 degrees between the courtyard wall above and the roof of a lower construction farther down. The keel, in spite of my weight, that of the motor and machinery, and the shock it had received in falling, resisted wonderfully. The thin pine scantlings and piano wires of Nice had saved my life! [Illustration: PHASE OF AN ACCIDENT] After what seemed tedious waiting I saw a rope being lowered to me from the roof above. I held to it, and was hauled up, when I perceived my rescuers to be the brave firemen of Paris. From their station at Passy they had been watching the flight of the air-ship. They had seen my fall, and immediately hastened to the spot. Then, having rescued me, they proceeded to rescue the air-ship. The operation was painful. The remains of the balloon envelope and the suspension wires hung lamentably, and it was impossible to disengage them except in strips and fragments! So I escaped--and my escape may have been narrow--but it was not from the particular danger always present in my mind during this period of trials around the Eiffel Tower. A Parisian journalist said that had the Eiffel Tower not existed it would have been necessary to invent it for the needs of aerostation. It is true that the engineers who remain at its summit have at their hands all necessary instruments for observing aerial and meteorological conditions: their chronometers are exact; and, as Professor Langley has said in a communication to the Louisiana Purchase Exposition Committee, the position of the Tower as a central landmark, visible to everyone from considerable distances, made it a unique winning-post for an aerial contest. I myself had circled round it at a respectful distance, of my own free will, in 1899, before the stipulation of the Deutsch prize competition was dreamed of. Yet none of these considerations altered the other fact that the necessity to round the Eiffel Tower attached a unique element of danger to the task. What I feared was that in my eagerness to make a quick turning, by some error in steering or by the influence of some unexpected side wind, I might be dashed against the Tower. The impact would certainly burst my balloon, and I should fall to the ground like a stone. Nor could the utmost prudence and self-control in making a wide turn guarantee me against the danger. Should my capricious motor stop as I approached the Tower--exactly as it stopped after I had passed over the timekeepers' heads at St Cloud, returning from my first trial on 13th July 1903--I should be powerless to hold the air-ship back. Therefore I always dreaded the turn round the Eiffel Tower, looking on it as my principal danger. While never seeking to go high in my air-ships--on the contrary, I hold the record for the low altitudes in a free balloon--in passing over Paris I must necessarily move above and out of the way of the chimney-pots and steeples. The Eiffel Tower was my one danger, yet it was my winning-post! Such were my fears while on the ground; while in the air I had no time for fear. I have always kept a cool head. Alone in the air-ship I am always busy, for there is more than enough work for one man. Like the captain of a yacht, I must not let go the rudder for an instant. Like its chief engineer, I must watch the motor. The balloon's rigidity of form must be preserved. And with this capital detail is connected the whole complex problem of the air-ship's altitude, the manoeuvring of guide rope and shifting weights, the economising of ballast, and the surveillance of the air pump attached to the motor. Besides all this occupation there is also the strong joy of commanding rapid movement. The pleasurable sensations of aerial navigation experienced in my first air-ships were intensified in the powerful "No. 5." As M. Jaurès has well put it, I now felt myself a man in the air, commanding movement. In my spherical balloons I had felt myself to be only the shadow of a man! CHAPTER XIV THE BUILDING OF MY "NO. 6" On the very evening of my fall to the roof of the Trocadero hotels I gave out the specifications of a "Santos-Dumont, No. 6," and after twenty-two days of continuous labour it was finished and inflated. [Illustration: Fig. 10] The new balloon had the shape of an elongated ellipsoid (Fig. 10), 33 metres (110 feet) by its great axis and 6 metres (20 feet) by its small axis, terminated fore and aft by cones. [Illustration: "No. 6." FIRST TRIP] I now gave more care than ever to the devices on which I depended to maintain the balloon's rigidity of form. I had fallen to the roof of the Trocadero hotels by the fault of the smallest and most insignificant-looking piece of mechanism of the entire system--a weakened valve that let out the balloon's hydrogen. In very much the same way the fall of the first of all my air-ships had been occasioned by the failure of a little air-pump. In all my constructions, except the big-bellied balloon of the "No. 3," I had depended much on the interior compensating air balloon (Fig. 5, page 119) fed by air pump or rotary ventilator. Sewed like a closed patch pocket to the inside bottom of the great balloon, this compensating air balloon would remain flat and empty so long as the great balloon remained distended with its gas. Then, as hydrogen might be condensed from time to time by changes of altitude and temperature, the air pump or ventilator worked by the motor would begin to fill the compensating air balloon, make it take up more room inside the great balloon, and so keep the latter distended. Inside the balloon of my "No. 6" I now sewed such a compensating balloon, capable of holding 60 cubic metres (2118 cubic feet). The ventilator that was to feed it formed practically a part of the motor itself. Revolving continually while the motor worked, it would serve air continually to the compensating balloon whether or not the latter would be able to hold it. What air it could not hold would escape through a comparatively weak valve ("Air Valve," Fig. 10) communicating with the outer atmosphere through the bottom of the air balloon, which was also the bottom of the great outer balloon. To relieve the great balloon of its dilated hydrogen when necessary I supplied it with two of the best valves I could make ("Gas Valves," Fig. 10). These also communicated with the outer atmosphere. Imagine, now, that after a certain condensation of my hydrogen the interior compensating balloon should have filled up in part with air from the ventilator and so maintained the form of the great balloon rigid. Shortly after, by a change of temperature or altitude, the hydrogen would begin to dilate again. Something would have to give way, or the balloon would burst in a "cold explosion." What ought to give way first? Evidently the weaker air valve ("Air Valve," Fig. 10). Letting out part or all of the air in the interior balloon, it would relieve the tension of the swelling hydrogen; and only afterwards, should this not be sufficient, would the stronger gas valves (Fig. 10) let out precious hydrogen. All three valves were automatic, opening outward on a given pressure from within. One of the hypotheses to account for the terrible accident to the unhappy Severo's dirigible "Pax"[A] is concerned with this all-important problem of valves. The "Pax," as originally constructed, had two. M. Severo, who was not a practical aeronaut, stopped up one of them with wax before starting on his first and last voyage. In view of the decreasing pressure of the atmosphere as one goes higher the ascent of a dirigible should always be slow and never great, for gas will expand on the rise of a few yards. It is quite different from the case of the spherical balloon, which has no interior pressure to withstand. A dirigible whose envelope is distended by great pressure depends on its valves not to burst. With one of its valves stopped with wax the "Pax" was allowed to shoot up from the earth, and immediately its occupants seem to have lost their heads. Instead of checking their rapid rise one of them threw out ballast--a handful of which will send up a great spherical balloon perceptibly. The mechanician of Severo is said to have been last seen throwing out a whole bag in his excitement. Up shot the "Pax" higher and higher, and the expansion, the explosion, and the awful fall came as a chain of consequences. [A] In the early morning of 12th May 1902 M. Augusto Severo, accompanied by his mechanician, Sachet, started from Paris on a first trial with the "Pax," the invention and construction of M. Severo. The "Pax" rose at once to a height almost double that of the Eiffel Tower, when, for reasons not precisely known, it exploded, and came crashing to earth with its two passengers. The fall took eight seconds to accomplish, and the luckless experimenters were picked up broken and shapeless masses. The tonnage of my new balloon was 630 cubic metres (22,239 cubic feet), affording an absolute lifting power of 690 kilogrammes (1518 lbs.), but the increased weight of the new motor and machinery, nevertheless, put my disposable ballast at 110 kilogrammes (242 lbs.). It was a four-cylinder motor of 12 horse-power, cooled automatically by the circulation of water round the top of the piston (culasse). While the water cooler brought extra weight, I was glad to have it, for the arrangement would permit me to utilise, without fear of overheating or jamming _en route_, the full power of the motor, which was able to communicate to the propeller a traction effort of 66 kilogrammes (145 lbs.). [Illustration: AN ACCIDENT TO "No. 6"] My daily practice with the new air-ship ended, 6th September 1901, in a slight accident. The balloon was reinflated by 15th September, but four days later it crashed against a tree in making a too sudden turn. Such accidents I have always taken philosophically, looking on them as a kind of insurance against more terrible ones. Were I to give a single word of caution to all dirigible balloonists, it would be: "Keep close to earth." The place of the air-ship is not in high altitudes, and it is better to catch in the tops of trees, as I used to do in the Bois de Boulogne, than to risk the perils of the upper air without the slightest practical advantage. CHAPTER XV WINNING THE DEUTSCH PRIZE And now, 19th October 1901, the air-ship "Santos-Dumont No. 6," having been repaired with great celerity, I tried again for the Deutsch prize and won it. On the day before the weather had been wretched. Nevertheless, I had sent out the necessary telegrams convoking the Commission. Through the night the weather had improved, but the atmospheric conditions at 2 o'clock in the afternoon--the hour announced for the trial--were, nevertheless, so unfavourable that of the twenty-five members composing the Commission only five made their appearance--MM. Deutsch (de la Meurthe), de Dion, Fonvielle, Besançon, and Aimé. The Central Meteorological Bureau, consulted at this hour by telephone, reported a south-east wind blowing 6 metres per second at the altitude of the Eiffel Tower. When I consider that I was content when my first air-ship in 1898 had, in the opinion of myself and friends, been going at the rate of 7 metres per second I am still surprised at the progress realised in those three years, for I was now setting out to win a race against a time limit in a wind blowing almost as fast as the highest speed I had realised in my first air-ship. [Illustration: SCIENTIFIC COMMISSION OF AËRO CLUB AT THE WINNING OF THE DEUTSCH PRIZE] The official start took place at 2.42 P.M. In spite of the wind striking me sidewise, with a tendency to take me to the left of the Eiffel Tower, I held my course straight to that goal. Gradually I drove the air-ship onward and upward to a height of about 10 metres above its summit. In doing this I lost some time, but secured myself against accidental contact with the Tower as much as possible. As I passed the Tower I turned with a sudden movement of the rudder, bringing the air-ship round the Tower's lightning conductor at a distance of about 50 metres from it. The Tower was thus turned at 2.51 P.M., the distance of 5-1/2 kilometres, _plus the turning_, being done in nine minutes. The return trip was longer, being in the teeth of this same wind. Also, during the trip to the Tower the motor had worked fairly well. Now, after I had left it some 500 metres behind me, the motor was actually on the point of stopping. I had a moment of great uncertainty. I must make a quick decision. It was to abandon the steering wheel for a moment, at the risk of drifting from my course, in order to devote my attention to the carburating lever and the lever controlling the electric spark. The motor, which had almost stopped, began to work again. I had now reached the Bois, where, by a phenomenon known to all aeronauts, the cool air from the trees began making my balloon heavier and heavier--or in true physics, smaller by condensation. By an unlucky coincidence the motor at this moment began slowing again. Thus the air-ship was descending, while its motive power was decreasing. To correct the descent I had to throw back both guide rope and shifting weights. This caused the air-ship to point diagonally upward, so that what propeller-force remained caused it to remount continually in the air. [Illustration: "No. 6." MAKING FOR EIFFEL TOWER; ALTITUDE 1000 FEET] I was now over the crowd of the Auteuil racetrack, already with a sharp pointing upward. I heard the applause of the mighty throng, when suddenly my capricious motor started working at full speed again. The suddenly-accelerated propeller being almost under the high-pointed air-ship exaggerated the inclination, so that the applause of the crowd changed to cries of alarm. As for myself, I had no fear, being over the trees of the Bois, whose soft greenery, as I have already stated, always reassured me. All this happened very quickly--before I had a chance to shift my weights and guide rope back to the normal horizontal positions. I was now at an altitude of 150 metres. Of course, I might have checked the diagonal mounting of the air-ship by the simple means of slowing the motor that was driving it upward; but I was racing against a time limit, and so I just went on. I soon righted myself by shifting the guide rope and the weights forward. I mention this in detail because at the time many of my friends imagined something terrible was happening. All the same, I did not have time to bring the air-ship to a lower altitude before reaching the timekeepers in the Aéro Club's grounds--a thing I might easily have done by slowing the motor. This is why I passed so high over the judges' heads. On my way to the Tower I never looked down on the house-tops of Paris: I navigated in a sea of white and azure, seeing nothing but the goal. On the return trip I had kept my eyes fixed on the verdure of the Bois de Boulogne and the silver streak of river where I had to cross it. Now, at my high altitude of 150 metres and with the propeller working at full power, I passed above Longchamps, crossed the Seine, and continued on at full speed over the heads of the Commission and the spectators gathered in the Aéro Club's grounds. At that moment it was eleven minutes and thirty seconds past three o'clock, making the time exactly twenty-nine minutes and thirty-one seconds. The air-ship, carried by the impetus of its great speed, passed on as a racehorse passes the winning-post, as a sailing yacht passes the winning-line, as a road racing automobile continues flying past the judges who have snapped its time. Like the jockey of the racehorse, I then turned and drove myself back to the aerodrome to have my guide rope caught and be drawn down at twelve minutes forty and four-fifths seconds past three, or thirty minutes and forty seconds from the start. I did not yet know my exact time. I cried: "Have I won?" And the crowd of spectators cried back to me: "Yes!" [Illustration: ROUND EIFFEL TOWER] * * * * * For a while there were those who argued that my time ought to be calculated up to the moment of my second return to the aerodrome instead of to the moment when I first passed over it, returning from the Eiffel Tower. For a while, indeed, it seemed that it might be more difficult to have the prize awarded to me than it had been to win it. In the end, however, common-sense prevailed. The money of the prize, amounting in all to 125,000 francs, I did not desire to keep. I, therefore, divided it into unequal parts. The greater sum, of 75,000 francs, I handed over to the Prefect of Police of Paris to be used for the deserving poor. The balance I distributed among my employees, who had been so long with me and to whose devotion I was glad to pay this tribute. At this same time I received another grand prize, as gratifying as it was unexpected. This was a sum of 100 contos (125,000 francs), voted to me by the Government of my own country, and accompanied by a gold medal of large size and great beauty, designed, engraved, and struck off in Brazil. Its obverse shows my humble self led by Victory and crowned with laurel by a flying figure of Renown. Above a rising sun there is engraved the line of Camoëns, altered by one word, as I adopted it to float on the long streamer of my air-ship: "Por _ceos_ nunca d'antes navegados!"[B] The reverse bears these words: "Being President of the Republic of the United States of Brazil, the Doctor Manoel Ferraz de Campos Salles has given order to engrave and strike this medal in homage to Alberto Santos-Dumont. 19th October 1901." [B] "Through _heavens_ hereto unsailed," instead of "_Por mares nunca d'antes navegados_"-- "O'er _seas_ hereto unsailed." [Illustration: ROUNDING EIFFEL TOWER] CHAPTER XVI A GLANCE BACKWARD AND FORWARD Just as I had not gone into air-ship constructing for the sake of winning the Deutsch prize, so now I had no reason to stop experimenting after I had won it. When I built and navigated my first air-ships neither Aéro Club nor Deutsch prize were yet in existence. The two, by their rapid rise and deserved prominence, had brought the problem of aerial navigation suddenly before the public--so suddenly, indeed, that I was really not prepared to enter into such a race with a time limit. Naturally anxious to have the honour of winning such a competition, I had been forced on rapidly in new constructions at both danger and expense. Now I would take time to perfect myself systematically as an aerial navigator. Suppose you buy a new bicycle or automobile. You will have a perfect machine to your hand without having had any of the labour, the deceptions, the false starts and recommencements, of the inventor and constructor. Yet with all these advantages you will soon find that possession of the perfected machine does not necessarily mean that you shall go spinning over the highways with it. You may be so unpractised that you will fall off the bicycle or blow up the automobile. The machine is all right, but you must learn to run it. To bring the modern bicycle to its perfection thousands of amateurs, inventors, engineers, and constructors laboured during more than twenty-five years, trying endless innovations, one by one rejecting the great mass of them, and, after endless failures by the way of half successes, slowly nearing to the perfect organism. So it is to-day with the automobile. Imagine the united labours and financial sacrifices of the engineers and manufacturers that led, step by step, up to the road-racing automobiles of the Paris-Berlin competition in 1901--the year in which the only working dirigible balloon then in existence won the Deutsch prize against a time limit that was thought by many a complete bar to success. Yet of the 170 perfected automobiles registered for entry to the Paris-Berlin competition only 109 completed the first day's run, and of these only 26 finally reached Berlin. [Illustration: RETURNING TO AËRO CLUB GROUNDS ABOVE AQUEDUCT] Out of 170 automobiles entered for the race only 26 reached the goal. And of these 26 arriving at Berlin how many do you imagine made the trip without serious accident? Perhaps none. It is perfectly natural that this should be so. People think nothing of it. Such is the natural development of a great invention. But if I break down while in the air I cannot stop for repairs: I must go on, and the whole world knows it. Looking back, therefore, on my progress since the time I doubled up above the Bagatelle grounds in 1898 I was surprised at the rapid pace at which I had allowed the notice of the world and my own ardour to push me on in what was in reality an arbitrary task. At the risk of my neck and the needless sacrifice of a great deal of money I had won the Deutsch prize. I might have arrived at the same point of progress by less forced and more reasonable stages. Throughout I had been inventor, patron, manufacturer, amateur, mechanician, and air-ship captain all united! Yet any one of these qualities is thought to bring sufficient work and credit to the individual in the world of automobiles. With all these cares I often found myself criticised for choosing calm days for my experiments. Yet who, experimenting over Paris--as I had to do when trying for the Deutsch prize--would add to his natural risks and expenses the vexations of who knows what prosecution for knocking down the chimney-pots of a great capital on the heads of a population of pedestrians? One by one I tried the assurance companies. None would make a rate for me against the damage I might do on a squally day. None would give me a rate on my own air-ship to insure it against destruction. To me it was now clear that what I most needed was navigation practice pure and simple. I had been increasing the speed of my air-ships--that is to say, I had been constructing at the expense of my education as an air-ship captain. The captain of a steamboat obtains his certificate only after years of study and experience of navigation in inferior capacities. Even the "chauffeur" on the public highway must pass his examination before the authorities will give him his papers. [Illustration: MEDAL AWARDED BY THE BRAZILIAN GOVERNMENT] In the air, where all is new, the routine navigation of a dirigible balloon, requiring for foundation the united experiences of the spherical balloonist and the automobile "chauffeur," makes demands upon the lone captain's coolness, ingenuity, quick reasoning, and a kind of instinct that comes with long habit. Urged on by these considerations, my great object in the autumn of 1901 was to find a favourable place for practice in aerial navigation. My swiftest and best air-ship--"The Santos-Dumont No. 6"--was in perfect condition. The day after winning the Deutsch prize in it my chief mechanician asked me if he should tighten it up with hydrogen. I told him yes. Then, seeking to let some more hydrogen into it, he discovered something curious. The balloon would not take any more! It had not lost a single cubic unit of hydrogen! The actual winning of the Deutsch prize had cost only a few litres of petroleum! Just as the Paris winter of biting winds, cold rains, and lowering skies was approaching I received an intimation that the Prince of Monaco, himself a man of science celebrated for his personal investigations, would be pleased to build a balloon house directly on the beach of La Condamine, from which I might dart out on the Mediterranean, and so continue my aerial practice through the winter. The situation promised to be ideal. The little bay of Monaco, sheltered from behind against the wind and cold by mountains, and from the wind and sea on either side by the heights of Monte Carlo and Monaco town, would make a well-protected manoeuvre ground. The air-ship would be always ready, filled with hydrogen gas. It could slip out of the balloon house to profit by good weather, and back again for shelter at the approach of squalls. The balloon house would be erected on the edge of the shore, and the whole Mediterranean would lie before me for guide-roping. [Illustration: "No. 9." SHOWING CAPTAIN LEAVING BASKET FOR MOTOR] CHAPTER XVII MONACO AND THE MARITIME GUIDE ROPE When I arrived at Monte Carlo, in the latter part of January 1902, the balloon house of the Prince of Monaco was already practically completed from suggestions I had given. The new aerodrome rose on the Boulevard de la Condamine, just across the electric tramcar tracks from the sea wall. It was an immense empty shell of wood and canvas over a stout iron skeleton 55 metres (180 feet) long, 10 metres (33 feet) wide, and 15 metres (50 feet) high. It had to be solidly constructed, not to risk the fate of the all-wood aerodrome of the French Maritime Ballooning Station at Toulon, twice wrecked, and once all but carried away, like a veritable wooden balloon, by tempests. In spite of the aerodrome's risky form and curious construction its sensational features were its doors. Tourists told each other (quite correctly) that doors so great as these had never been before in ancient times or modern. They had been made to slide open and shut, above on wheels hanging from an iron construction that extended from the façade on each side, and below on wheels that rolled over a rail. Each door was 15 metres (50 feet) high by 5 metres (16-1/2 feet) wide, and each weighed 4400 kilogrammes (9680 lbs.). Yet their equilibrium was so well calculated that on the day of the inauguration of the aerodrome these giant doors were rolled apart by two little boys of eight and ten years respectively, the young Princes Ruspoli, grandsons of the Duc de Dino, my host at Monte Carlo. While the new situation attracted me by its promise of convenient and protected winter practice the prospect of doing some oversea navigation with my air-ship was even more alluring. Even to the spherical balloonist the oversea problem has great temptations, concerning which an expert of the French Navy has said: "The balloon can render the navy immense services, _on condition that its direction can be assured_. "Floating over the sea, it can be at once scout and offensive auxiliary of so delicate a character that the general service of the navy has not yet allowed itself to pronounce on the matter. We can no longer conceal it from ourselves, however, that the hour approaches when balloons, now become military engines, will acquire, from the point of view of battle results, a great and, perhaps, decisive influence in war." [Illustration: IN THE BAY OF MONACO] As for myself, I have never made it any secret that, to my mind, the first practical use of the air-ship will be found in war, and the far-seeing Henri Rochefort, who was in the habit of coming to the aerodrome from his hotel at La Turbie, wrote a most significant editorial in this sense after I had laid before him the speed calculations of my "No. 7," then in course of building. "The day when it shall be established that a man can make his air-ship travel in a given direction and manoeuvre it at will during the four hours which the young Santos demands to go from Monaco to Calvi," wrote Henri Rochefort, "there will remain little more for the nations to do than to throw down their arms.... "I am astonished that the capital importance of this matter has not yet been grasped by all the professionals of aerostation. To mount in a balloon that one has not constructed, and which one is not in a state to guide, constitutes the easiest of performances. A little cat has done it at the Folies-Bergère." Now in war service overland the air-ship will, doubtless, have often to mount to considerable heights to avoid the rifle fire of the enemy, but, as the maritime auxiliary described by the expert of the French Navy, its scouting _rôle_ will for the most part be performed at the end of its guide rope, comparatively close to the waves, and yet high enough to take in a wide view. Only when for easily-imagined reasons it is desired to mount high for a short time will it quit the convenient contact of its guide rope with the surface of the sea. For these considerations--and particularly the last--I was anxious to do a great deal of guide-roping over the Mediterranean. If the maritime experiment promises so much to spherical ballooning it is doubly promising to the air-ship, which, from the nature of its construction, carries comparatively little ballast. This ballast ought not to be currently sacrificed, as it is by the spherical balloonist, for the remedying of every little vertical aberration. Its purpose is for use in great emergencies. Nor ought the aerial navigator, particularly if he be alone, be forced to rectify his altitude continually by means of his propeller and shifting weights. He ought to be free to navigate his air-ship; if on pleasure bent, with ease and leisure to enjoy his flight; if on war service, with facility for his observations and hostile manoeuvres. Therefore any _automatic_ guarantee of vertical stability is peculiarly welcome to him. You know already what the guide rope is. I have described it in my first experience of spherical ballooning. Overland, where there are level plains or roads or even streets, where there are not too many troublesome trees, buildings, fences, telegraph and trolley poles and wires and like irregularities, the guide rope is as great an aid to the air-ship as to the spherical balloon. Indeed, I have made it more so, for with me it is the central feature of my shifting weights (Figs. 8 and 9, page 148). Over the uninterrupted stretches of the sea my first Monaco flight proved it to be a true _stabilisateur_. Its very slight dragging resistance through the water is out of all proportion to the considerable weight of its floating extremity. According to its greater or less immersion, therefore, it ballasts or unballasts the air-ship (Fig. 11). The balloon is held by the weight of the guide rope down to a fixed level over the waves without danger of being drawn into contact with them. For the moment that the air-ship descends the slightest distance nearer to them that very moment it becomes relieved of just so much weight, and must naturally rise again by that amount of momentary unballasting. In this way an incessant little tugging toward and away from the waves is produced, infinitely gentle, an automatic ballasting and unballasting of the air-ship without loss of ballast. [Illustration: Fig. 11] My first flight over the Mediterranean, which was made on the morning of 29th January 1902, proved more than this, unfortunately. It was seen that a miscalculation had been made with respect to the site of the aerodrome itself. In the navigation of the air, where all is new, such surprises meet the experimenter at every turn. This ought to be remembered when one takes account of progress. In the Paris-Madrid automobile race of 1903 what minute precautions were not taken to secure the competitors against the perils of quick turnings and grade crossings? And yet how notably insufficient did they not turn out to be. As the air-ship was being taken out from its house for its first flight on the morning of 29th January 1902 the spectators could see that nothing equivalent to the landing-stages which the air-ships of the future must have built for them existed in front of the building. The air-ship, loaded with ballast until it was a trifle heavier than the surrounding atmosphere, had to be towed, or helped, out of the aerodrome and across the Boulevard de la Condamine before it could be launched into the air over the sea wall. Now that sea wall proved to be a dangerous obstruction. From the side walk it was only waist high, but on the other side of it the surf rolled over pebbles from four to five metres below. The air-ship had to be lifted over the sea wall more than waist high; also, not to risk damaging the arms of its propeller, and when half over, there was no one to sustain it from the other side. Its stem pointed obliquely downward, while its stern threatened to grind on the wall. Scuffling among the pebbles below, on the sea side, half-a-dozen workmen held their arms high toward the descending keel as it was let down and pushed on toward them by the workmen in charge of it on the boulevard in front of the wall, and they were at last able to catch and right it only in time to prevent me from being precipitated from the basket. [Illustration: FROM THE BALLOON HOUSE OF LA CONDAMINE AT MONACO, FEB. 12, 1902] For this reason my return to the aerodrome after this first flight became the occasion of a real triumph, for the crowd promptly took cognisance of the perils of the situation and foresaw difficulties for me when I should attempt to re-enter the balloon house. As there was no wind, however, and as I steered boldly, I was able to make a sensational entry without damage--and without aid. Straight as a dart the air-ship sped to the balloon house. The police of the prince had with difficulty cleared the boulevard between the sea wall and the wide-open doors. Assistants and supernumeraries leaned over the wall with outstretched arms waiting for me; below on the beach were others, but this time I did not need them. I slowed the speed of the propeller as I came to them. Just as I was half way over the sea wall, well above them all, I stopped the motor. Carried onward by the dying momentum, the air-ship glided over their heads on toward the open door. They had grasped my guide rope to draw me down, but as I had been coming diagonally there was no need of it. Now they walked beside the air-ship into the balloon house, as its trainer or the stable-boys grasp the bridle of their racehorse after the course and lead him back in honour to the stable with his jockey in the saddle. It was admitted, nevertheless, that I ought not to be obliged to steer so closely on returning from my flights--to enter the aerodrome as a needle is threaded by a steady hand--because a side gust of wind might catch me at the critical moment and dash me against a tree or lamp-post, or telegraph or telephone pole, not to speak of the sharp-cornered buildings on either side of the aerodrome. When I went out again for a short spin that same afternoon of 29th January 1902 the obstruction of the sea wall made itself only too evident. The prince offered to tear down the wall. "I will not ask you to do so much," I said. "It will be enough to build a landing-stage on the sea side of the wall at the level of the boulevard." This was done after twelve days of work, interrupted by persistent rain, and the air-ship, when it issued for its third flight, 10th February 1902, had simply to be lifted a few feet by men on each side of the wall. They drew it gently on until its whole length floated in equilibrium over the new platform that extended so far out into the surf that its farthermost piles were always in six feet of water. Standing on this platform they steadied the air-ship while its motor was beings started, while I let out the overplus of water ballast and shifted my guide rope so as to point for an oblique drive upward. The motor began spitting and rumbling. The propeller began turning. "Let go all!" I cried, for the third time at Monaco. Lightly the air-ship slid along its oblique course, onward and upward. Then as the propeller gathered force a mighty push sent me flying over the bay. I shifted forward the guide rope again to make a level course. And out to sea the air-ship darted, its scarlet pennant fluttering symbolic letters as upon a streak of flame. They were the initial letters of the first line of Camoëns' "Lusiad," the epic poet of my race: Por mares nunca d'antes navegados! (O'er seas hereto unsailed.) CHAPTER XVIII FLIGHTS IN MEDITERRANEAN WINDS In my two previous experiments I had kept fairly within the wind-protected limits of the bay of Monaco, whose broad expanse afforded ample room both for guide-roping and practice in steering. Furthermore, a hundred friends and thousands of friendly spectators stood around it from the terraces of Monte Carlo to the shore of La Condamine and up the other side to the heights of Old Monaco. As I circled round and round the bay, mounted obliquely and swooped down, fetched a straight course, and then stopped abruptly to turn and begin again, their applause came up to me agreeably. Now, on my third flight, I steered for the open sea. Out into the open Mediterranean I sped. The guide rope held me at a steady altitude of about 50 metres above the waves, as if in some mysterious way its lower end were attached to them. In this way, automatically secure of my altitude, I found the work of aerial navigation become wonderfully easy. There was no ballast to throw out, no gas to let out, no shifting of the weights except when I expressly desired to mount or descend. So with my hand upon the rudder and my eye fixed on the far-off point of Cap Martin I gave myself up to the pleasure of this voyaging above the waves. Here in these azure solitudes there were no chimney-pots of Paris, no cruel, threatening roof-corners, no tree-tops of the Bois de Boulogne. My propeller was showing its power, and I was free to let it go. I had only to hold my course straight in the teeth of the breeze and watch the far-off Mediterranean shore flit past me. I had plenty of leisure to look about. Presently I met two sailing yachts scudding towards me down the coast. I noticed that their sails were full-bellied. As I flew on over them, and they beneath me, I heard a faint cheer, and a graceful female figure on the foremost yacht waved a red foulard. As I turned to answer the politeness I perceived with some astonishment that we were far apart already. I was now well up the coast, about half-way to Cap Martin. Above was the limitless blue void. Below was the solitude of white-capped waves. From the appearance of sailing boats here and there I could tell that the wind was increasing to a squall, and I would have to turn in it before I could fly back upon it in my homeward trip. Porting my helm I held the rudder tight. The air-ship swung round like a boat; then as the wind sent me flying down the coast my only work was to maintain the steady course. In scarcely more time than it takes to write it I was opposite the bay of Monaco again. With a sharp turn of the rudder I entered the protected harbour, and amid a thousand cheers stopped the propeller, pulled in the forward shifting weight, and let the dying impetus of the air-ship carry it diagonally down to the landing-stage. This time there was no trouble. On the broad landing-stage stood my own men, assisted by those put at my disposition by the prince. The air-ship was grasped as it came gliding slowly to them, and, without actually coming to a stop, it was "led" over the sea wall across the Boulevard de la Condamine and into the aerodrome. The trip had lasted less than an hour, and I had been within a few hundred metres (yards) of Cap Martin. Here was an obvious trip, first against and then with a stiff wind, and the curious may render themselves an account of the fact by glancing at the two photographs marked "Wind A" and "Wind B." As they happened to be taken by a Monte Carlo professional intent simply on getting good photographs they are impartial. "Wind A" shows me leaving the bay of Monaco against a wind that is blowing back the smoke of the two steamers seen on the horizon. "Wind B" was taken up the coast just before I met the two little sailing yachts which are obviously scudding toward me. The loneliness in which I found myself in the middle of this first extended flight up the Mediterranean shore was not part of the programme. During the manufacture of the hydrogen gas and the filling of the balloon I had received the visits of a great many prominent people, several of whom signified their ability and readiness to lend valuable aid to these experiments. From Beaulieu, where his steam-yacht, _Lysistrata_, was at anchor, came Mr James Gordon Bennett, and Mr Eugene Higgins had already brought the _Varuna_ up from Nice on more than one occasion. The beautiful little steam-yacht of M. Eiffel also held itself in readiness. It had been the intention of these owners, as it had been that of the prince with his _Princesse Alice_, to follow the air-ship in its flights over the Mediterranean, so as to be on the spot in case of accident. This first flight, however, had been taken on impulse before any programme for the yachts had been arranged, and my next long flight, as will be seen, demonstrated that this kind of protection must not be counted on overmuch by air-ship captains. It was on the 12th of February 1902. One steam chaloupe and two petroleum launches, all three of them swift goers, together with three well-manned row-boats, had been stationed at intervals down the coast to pick me up in case of accident. The steam _chaloupe_ of the Prince of Monaco, carrying His Highness, the Governor-General, and the captain of the _Princesse Alice_, had already started on the course ahead of time. The 40 horse-power Mors automobile of Mr Clarence Grey Dinsmore and the 30 horse-power Panhard of M. Isidore Kahenstein were prepared to follow along the lower coast road. [Illustration: "WIND A"] [Illustration: "WIND B"] Immediately on leaving the bay of Monaco I met the wind head on as I steered my course straight down the coast in the direction of the Italian frontier. Putting on all speed I held the rudder firm and let myself go. I could see the ragged outlines of the coast flit past me on the left. Along the winding road the two racing automobiles kept abreast with me, being driven at high speed. "It was all we could do to follow the air-ship along the curves of the coast road," said one of Mr Dinsmore's passengers to the reporter of a Paris journal, "so rapid was its flight. In less than five minutes it had arrived opposite the Villa Camille Blanc, which is about a kilometre (3/4 of a mile) distant from Cap Martin as the crow flies. "At this moment the air-ship was absolutely alone. Between it and Cap Martin I saw a single row-boat, while far behind was visible the smoke from the prince's _chaloupe_. It was really no commonplace sight to see the air-ship thus hovering isolated over the immense sea." The wind instead of subsiding had been increasing. Here and there around the horizon I could see the bent white sails of yachts driven before it. The situation was new to me, so I made an abrupt turn and started back on the home stretch. Now again the wind was with me, stronger than it had been on the preceding flight down the coast. Yet it was easy steering, and I remarked with pleasure that going thus with the wind the pitching or _tangage_ of the air-ship was much less. Though going fast with my propeller, and aided by the wind behind me, I felt no more motion, indeed even less, than before. For the rest, how different were my sensations from those of the spherical balloonist! It is true that he sees the earth flying backward beneath him at tremendous speed. But he knows that he is powerless. The great sphere of gas above him is the plaything of the air current, and he cannot change his direction by a hair's-breadth. In my air-ship I could see myself flying over the sea, but I had my hands on a helm that made me master of my direction in this splendid course. Once or twice, merely to give myself an account of it, I shoved the helm around a short arc. Obedient, the air-ship's stem swung to the other side, and I found myself speeding in a new diagonal course. But these manoeuvres only occupied a few instants each, and each time I swung myself back on a straight line to the entrance to the bay of Monaco, for I was flying homeward like an eagle, and must keep my course. To those watching my return, from the terraces of Monte Carlo and Monaco town, as they told me afterwards, the air-ship increased in size at every instant, like a veritable eagle bearing down upon them. As the wind was coming toward them they could hear the low, crackling rumble of my motor a long distance off. Faintly, now, their own shouts of encouragement came to me. Almost instantly the shouts grew loud. Around the bay a thousand handkerchiefs were fluttering. I gave a sharp turn to the helm, and the air-ship leaped into the bay amid the cheering and the waving just as great raindrops were beginning to fall.[C] [C] "Half-an-hour after the aeronaut's return the wind became violent, a heavy storm followed, and the sea became very rough." (Paris edition, _New York Herald_, 13th February 1902.) I had first slowed and then stopped the motor. As the air-ship now gently approached the landing-stage, borne on by its dying momentum, I gave the usual signal for those in the boats to seize my guide rope. The steam _chaloupe_ of the prince, which had turned back midway between Monte Carlo and Cap Martin after I had overtaken and passed it on my out trip, had by this time reached the bay. The prince, who was still on board, desired to catch the guide rope; and those with him, having no experience of its weight and the force with which the air-ship drags it through the water, did not seek to dissuade him. Instead of catching the heavy floating cordage as the darting _chaloupe_ passed it His Highness managed to get struck by it on the right arm, an accident which knocked him fairly to the bottom of the little vessel and produced severe contusions. A second attempt to catch the guide rope was more successful, and the air-ship was easily drawn to the sea wall, over it, and into its house. Like everything in this new navigation, the particular manoeuvre was new. I was still going faster than I appeared to be, and such attempts to catch and stop an air-ship even on its dying momentum are apt to upset someone. The only way not to get too abrupt a shock is to run with the machine and slow it down gently. CHAPTER XIX SPEED What speed my "No. 6" made on those Mediterranean flights was not published at the time because I had not sought to calculate it closely. Fresh from the troubling time limit of the Deutsch prize competition I amused myself frankly with my air-ship, making observations of great value to myself, but not seeking to prove anything to anyone. The speed problem is, doubtless, the first of all air-ship problems. Speed must always be the final test between rival air-ships, and until high speed shall be arrived at certain other problems of aerial navigation must remain in part unsolved. For example, take that of the air-ship's pitching (_tangage_). I think it quite likely that a critical point in speed will be found, beyond which, on each side, the pitching will be practically _nil_. When going slowly or at moderate speed I have experienced no pitching, which in an air-ship like my "No. 6" seems always to commence at 25 to 30 kilometres (15 to 18 miles) per hour through the air. Now, probably, when one passes this speed considerably--say at the rate of 50 kilometres (30 miles) per hour--all _tangage_ or pitching will be found to cease again, as I myself experienced when flying homeward on the wind in the voyage last described. Speed must always be the final test between rival air-ships, because, in itself, speed sums up all other air-ship qualities, including "stability." At Monaco, however, I had no rivals to compete with. Furthermore, my prime study and amusement there was the beautiful working of the maritime guide rope; and this guide rope, dragging through the water, must of necessity retard whatever speed I made. There could be no help for it. Such was the price I must pay for automatic equilibrium and vertical stability--in a word, easy navigation--so long as I remained the sole and solitary navigator of the air-ship. Nor is it an easy task to calculate an air-ship's speed. On those flights up and down the Mediterranean coast the speed of my return to Monaco, wonderfully aided by the wind, could bear no relation to the speed out, retarded by the wind, and there was nothing to show that the force of the wind going and coming was constant. It is true that on those flights one of the difficulties standing in the way of such speed calculations--the "shoot the chutes" (_montagnes Russes_) of ever-varying altitude--was done away with by the operation of the maritime guide rope; but, on the other hand, as has been said, the dragging of the guide rope's weight through the water acted as a very effectual brake. As the speed of the air-ship is increased this brake-like action of the guide rope (like that of the resistance of the atmosphere itself) grows, not in proportion to the speed, but in proportion to the square of it. On those flights along the Mediterranean coast the easy navigation afforded me by the maritime guide rope was purchased, as nearly as I could calculate, by the sacrifice of about 7 or 8 kilometres (4 or 5 miles) per hour of speed; but with or without maritime guide rope the speed calculation has its own almost insurmountable difficulties. From Monte Carlo to Cap Martin at 10 o'clock of a given morning may be quite a different trip from Monte Carlo to Cap Martin at noon of the same day; while from Cap Martin to Monte Carlo, except in perfect calm, must always be a still different proposition. Nor can any accurate calculations be based on the markings of the anemometer, an instrument which I, nevertheless, carried. Out of simple curiosity I made note of its readings on several occasions during my trip of 12th February 1902. It seemed to be marking between 32 and 37 kilometres (20 and 23 miles) per hour; but the wind, complicated by side gusts, acting at the same time on the air-ship and the wings of the anemometer windmill--_i.e._ on two moving systems whose inertia cannot possibly be compared--would alone be sufficient to falsify the result. When, therefore, I state that, according to my best judgment, the average of my speed through the air on those flights was between 30 and 35 kilometres (18 and 22 miles) per hour, it will be understood that it refers to speed through the air whether the air be still or moving and to speed retarded by the dragging of the maritime guide rope. Putting this adverse influence at the moderate figure of 7 kilometres (4-1/2 miles) per hour my speed through the still or moving air would be between 37 and 42 kilometres (22 and 27 miles) per hour. Rather than spend time over illusory calculations on paper I have always preferred to go on materially improving my air-ships. Later, when they come in competition with the rivals which no one awaits more ardently than myself, all speed calculations made on paper and all disputes based on them must of necessity yield to the one sublime test of air-ship racing. Where speed calculations have their real importance is in affording necessary _data_ for the construction of new and more powerful air-ships. Thus the balloon of my racing "No. 7," whose motive power depends on two propellers each 5 metres (16-1/2 feet) in diameter, and worked by a 60 horse-power motor with a water cooler, has its envelope made of two layers of the strongest French silk, four times varnished, capable of standing, under dynamometric test, a traction of 3000 kilogrammes (6600 pounds) for the linear metre (3·3 feet). I will now try to explain why the balloon envelope must be made so very much stronger as the speed of the air-ship is designed to be increased; and in so doing I shall have to reveal the unique and paradoxical danger that besets high-speed dirigibles, threatening them, not with beating their heads in against the outer atmosphere, but with blowing their tails out behind them. Although the interior pressure in the balloons of my air-ships is very considerable, as balloons go, the spherical balloon, having a hole in its bottom, is under no such pressure: it is so little in comparison with the general pressure of the atmosphere, that we measure it, not by "atmospheres," but by centimetres or millimetres of water pressure--_i.e._ the pressure that will send a column of water up that distance in a tube. One "atmosphere" means one kilogramme of pressure to the square centimetre (15 lbs. to the square inch), and it is equivalent to about 10 metres of water pressure, or, more conveniently, 1000 centimetres of "water." Now, supposing the interior pressure in my slower "No. 6" to have been close up to 3 centimetres of water (it required that pressure to open its gas valves), it would have been equivalent to 1/333 of an atmosphere; and as one atmosphere is equivalent to a pressure of 1000 grammes (1 kilogramme) on one square centimetre the interior pressure of my "No. 6" would have been 1/333 of 1000 grammes, or 3 grammes. Therefore on one square metre (10,000 square centimetres) of the stem head of the balloon of my "No. 6" the interior pressure would have been 10,000 multiplied by 3, or 30,000 grammes _i.e._--30 kilogrammes (66 lbs.). [Illustration: "SANTOS-DUMONT No. 7"] How is this interior pressure maintained without being exceeded? Were the great exterior balloon filled with hydrogen and then sealed up with wax at each of its valves, the sun's heat might expand the hydrogen, make it exceed this pressure, and burst the balloon; or should the sealed balloon rise high, the decreasing pressure of the outer atmosphere might let its hydrogen expand, with the same result. The gas valves of the great balloon, therefore, must _not_ be sealed; and, furthermore, they must always be very carefully made, so that they will open of their own accord at the required and calculated pressure. This pressure (of 3 centimetres in the "No. 6"), it ought to be noted, is attained by the heating of the sun or by a rise in altitude only when the balloon is completely filled with gas: what may be called its working pressure--about one-fifth lower--is maintained by the rotary air pump. Worked continually by the motor, it pumps air continually into the smaller interior balloon. As much of this air as is needed to preserve the outer balloon's rigidity remains inside the little interior balloon, but all the rest pushes its way out into the atmosphere again through its air valve, which opens at a little less pressure than do the gas valves. Let us now return to the balloon of my "No. 6." The _interior_ pressure on each square metre of its stem head being continuously about 30 kilogrammes the silk material composing it must be normally strong enough to stand it; nevertheless, it will be easy to see how it becomes more and more relieved of that interior pressure as the air-ship gets in motion and increases speed. Its striking against the atmosphere makes a counter pressure _against the outside_ of the stem head. Up to 30 kilogrammes to the square metre, therefore, all increase in the air-ship's speed tends to reduce strain, so that the faster the air-ship goes the less will it be liable to burst out its head! How fast may the balloon be carried on by motor and propeller before its head stem strikes the atmosphere hard enough to more than neutralise the interior pressure? This, too, is a matter of calculation; but, to spare the reader, I will content myself with pointing out that my flights over the Mediterranean proved that the balloon of my "No. 6" could safely stand a speed of 36 to 42 kilometres (22 to 27 miles) per hour without giving the slightest hint of strain. Had I wanted an air-ship of the proportions of the "No. 6" to go twice as fast under the same conditions its balloon must have been strong enough to stand four times its interior pressure of 3 centimetres of "water," because the resistance of the atmosphere grows not in proportion to the speed but in proportion to the square of the speed. The balloon of my "No. 7" is not, of course, built in the precise proportions of that of my "No. 6," but I may mention that it has been tested to resist an interior pressure of much more than 12 centimetres of "water"; in fact, its gas valves open at that pressure only. This means just four times the interior pressure of my "No. 6." Comparing the two balloons in a general way, it is obvious, therefore, that with no risk from outside pressure, and with positive relief from interior pressure on its stem or head, the balloon of my "No. 7" may be driven twice as fast as my easy-going Mediterranean pace of 42 kilometres (25 miles) per hour, or 80 kilometres (50 miles). This brings us to the unique and paradoxical weakness of the fast-going dirigible. Up to the point where the exterior shall equal the interior pressure we have seen how every increase of speed actually guarantees safety to the stem of the balloon. Unhappily, it does not remain true of the balloon's stern head. On it the interior pressure is also continuous, but speed cannot relieve it. On the contrary, the _suction_ of the atmosphere behind the balloon, as it speeds on, increases also almost in the same proportion as the pressure caused by driving the balloon against the atmosphere. And this suction, instead of operating to neutralise the interior pressure on the balloon's stern head, _increases_ the strain just that much, the pull being added to the push. Paradoxical as it may seem, therefore, the danger of the swift dirigible is to blow its tail out rather than its head in. (See Fig. 12.) [Illustration: Fig. 12] How is this danger to be met? Obviously by strengthening the stern part of the balloon envelope. We have seen that when the speed of my "No. 7" shall be just great enough to completely neutralise the interior pressure on its stem head the strain on its stern head will be practically doubled. For this reason I have doubled the balloon material at this point. I have reason to be careful of the balloon of my "No. 7." In it the speed problem will be attacked definitely. It has two propellers, each 5 metres (16-1/2 feet) in diameter. One will push, as usual, from the stern, while the other will pull from the stem, as in my "No. 4." Its 60 horse-power Clement motor will, if my expectations are fulfilled, give it a speed of between 70 and 80 kilometres (40 and 50 miles) per hour. In a word, the speed of my "No. 7" will bring us very close to practical, everyday aerial navigation, for as we seldom have a wind blowing as much even as 50 kilometres (30 miles) per hour such an air-ship will surely be able to go out daily during more than ten months in the twelve. CHAPTER XX AN ACCIDENT AND ITS LESSONS At half-past two o'clock on the afternoon of the 14th of February 1902 the staunch air-ship which won the Deutsch prize left the aerodrome of La Condamine on what was destined to be its last voyage. Immediately on quitting the aerodrome it began behaving badly, dipping heavily. It had left the balloon house imperfectly inflated, hence it lacked ascensional force. To keep my proper altitude I increased its diagonal pointing and kept the propeller pushing it on upward. The dipping, of course, was due to the counter effort of gravity. In the shaded atmosphere of the aerodrome the air had been comparatively cool. The balloon was now out in the hot, open sunlight. As a consequence, the hydrogen nearest to the silk cover rarefied rapidly. As the balloon had left the aerodrome imperfectly inflated the rarefied hydrogen was able to rush to the highest possible point--the up-pointing stem. This exaggerated the inclination which I had made purposely. The balloon pointed higher and higher. Indeed, for a time, it seemed almost to be pointing perpendicularly. Before I had time to correct this "rearing up" of my aerial steed many of the diagonal wires had begun to give way, as the slanting pressure on them was unusual, and others, including those of the rudder, caught in the propeller. Should I leave the propeller to grind on the rigging the balloon envelope would be torn the next moment, the gas would leave the balloon in a mass, and I would be precipitated into the waves with violence. I stopped the motor. I was now in the position of an ordinary spherical balloonist--at the mercy of the winds. These were taking me in shore, where I would be presently cast upon the telegraph wires, trees, and house corners of Monte Carlo. There was but one thing to do. Pulling on the manoeuvre valve I let out a sufficient quantity of hydrogen and came slowly down to the surface of the water, in which the air-ship sank. Balloon, keel, and motor were successfully fished up the next day and shipped off to Paris for repairs. Thus abruptly ended my maritime experiments; but thus also I learned that, while a properly inflated balloon, furnished with the proper valves, has nothing to fear from gas displacement, it is best to be on the safe side and guard oneself against the possibility of such displacement, when by some neglect or other the balloon is allowed to go out imperfectly inflated. For this reason, in all my succeeding air-ships, the balloon is divided into many compartments by vertical silk partitions, not varnished. The partitions remaining unvarnished, the hydrogen gas can slowly pass through their meshes from one compartment to another to ensure an equal pressure throughout. But as they are, nevertheless, partitions, they are always ready to guard against any precipitous rushing of gas toward either extremity of the balloon. Indeed, the experimenter with dirigible balloons must be continually on his guard against little errors and neglects of his aids. I have four men who have now been with me four years. They are in their way experts, and I have every confidence in them. Yet this thing happened: the air-ship was allowed to leave the aerodrome imperfectly inflated. Imagine, then, what might be the danger of an experimenter with a set of inexperienced subordinates. In spite of their great simplicity my air-ships require constant surveillance on a few capital heads: Is the balloon properly filled? Is there any possibility of a leak? Is the rigging in condition? Is the motor in condition? Do the cords commanding rudder, motor, water ballast, and the shifting guide rope work freely? Is the ballast properly weighed? Looked on as a mere machine the air-ship requires no more care than an automobile, but, from the point of view of consequences, the need of faithful and intelligent surveillance is simply imperious. This very day all the highways of France are dotted with a thousand automobiles _en panne_, with their enthusiastic drivers crawling underneath them in the dust, oil-can and wrench in hand, repairing momentary accidents. They think no less of their automobile for this reason. Yet let the air-ship have the same trifling accident and all the world is likely to hear of the fact. In the first years of my experiments I insisted on doing everything for myself. I "groomed" my balloons and motors with my own hands. My present aids understand my present air-ships, and nine times out of ten they hand them over to me in good condition for the voyage. Yet were I to begin experiments with a new type I should have to train them all anew, and during that time I should have to care for the air-ships with my own hands again. On this occasion the air-ship left the aerodrome imperfectly weighed and inflated, not so much by the neglect of my men as by reason of the imperfect situation of the aerodrome. In spite of the care that had been given to designing and constructing it, from the very nature of its situation there was no space outside in which to send up the air-ship and ascertain if its ballast were properly distributed. Could this have been done the imperfect inflation of the balloon would have been perceived in time. Looking back over all my varied experiences I reflect with astonishment that one of my greatest dangers passed unperceived, even by myself at the end of my most successful flight over the Mediterranean. [Illustration: "MY PRESENT AIDS UNDERSTAND MY PRESENT AIRSHIPS" MOTOR OF "No. 6"] It was at the time the prince attempted to grasp my guide rope and was knocked into the bottom of his steam _chaloupe_. I had entered the bay after flying homeward up the coast, and they were towing me toward the aerodrome. The air-ship had descended very close to the surface of the water, and they were pulling it still lower by means of the guide rope, until it was not many feet above the smoke-stack of the steam _chaloupe_--and that smoke-stack was belching red-hot sparks. Any one of those red-hot sparks might have, ascending, burned a hole in my balloon, set fire to the hydrogen, and blown balloon and myself to atoms. CHAPTER XXI THE FIRST OF THE WORLD'S AIR-SHIP STATIONS Air-ship experimenters labour under one peculiar disadvantage, quite apart from the proper difficulties of the problem. It is due to the utter newness of travel in a third dimension, and consists in the slowness with which our minds realise the necessity of providing for the diagonal mountings and descents of the air-ships starting from and returning to the ground. When the Aéro Club of Paris laid out its grounds at St Cloud it was with the sole idea of facilitating the vertical mounting of spherical balloons. Indeed, no provisions were made even for the landing of spherical balloons, because their captains never hoped to bring them back to the St Cloud balloon park otherwise than by rail, packed in their boxes. The spherical balloon lands where the wind takes it. When I built my first air-ship house in the Club's grounds at St Cloud I dare say that the then novel advantages of possessing my own gas plant, workshop, and a shelter in which the inflated dirigibles could be housed indefinitely withheld my attention from this other almost vital problem of surroundings. It was already a great progress for me not to be obliged to empty the balloon and waste its hydrogen at the end of each trip. Thus I was content to build simply an air-ship house with great sliding doors without even taking precautions to guarantee a flat, open space in front, and, less still, on either side of it. When, little by little, trenches something like a metre (yard) deep--vague foundation outlines for constructions that were never finished--began appearing here and there to the right of my open doors and on beyond I realised that my aids might risk falling into them in running to catch my guide rope when I should be returning from a trip. And when the gigantic skeleton of M. Henry Deutsch's air-ship house, designed to shelter the air-ship he built on the lines of my "No. 6," and called "La Ville de Paris," rose directly in front of my sliding doors, scarcely two air-ships' lengths distant from them, it dawned on me at last that here was something of a peril, and more than a simple inconvenience due to natural crowding in a club's grounds. In spite of the new peril the Deutsch prize was won. Returning from the Eiffel Tower I passed high above the skeleton. I may say here, however, that the foundation trenches innocently caused the painful controversy about my time, to which I have made a brief allusion in the chapter. Seeing that they might easily break their legs by stumbling into those foundation trenches I had positively forbidden my men to run across that space to catch my guide rope with their eyes and arms up in the air. Not dreaming that such a point could be raised, my men obeyed the injunction. Observing that I was quite master of my rudder, motor, and propeller, able to turn and return to the spot where the judges stood, they let me pass on over their heads without seeking to catch and run along with the guide rope, a thing they might have done easily--at the risk of their legs. Again, at Monaco, after a well-planned air-ship house had been erected in what seemed an ideal spot, we have seen what dangers were, nevertheless, threatened by the sea wall, the Boulevard de la Condamine with its poles, wires, and traffic, and the final disaster, due entirely to the absence of a weighing ground beside the aerodrome. These are dangers and inconveniences against which we come in time to be on our guard by actual and often dire experience. [Illustration: "SANTOS-DUMONT No. 5" SHOWING HOW AËRO CLUB GROUNDS WERE CUT UP] During the spring and summer of 1902 I took trips to England and the United States, of which I shall have a word to say later. Returning from those trips to Paris I at once set about selecting the site of an aerodrome that should be all my own and in which the experience gained at such cost should be taken advantage of. This time I resolved my air-ship house should have an ample space around it. And, succeeding in a way, I realised--if I may say it--the first of the air-ship stations of the future. After long search I came on a fair-sized lot of vacant ground surrounded by a high stone wall, inside the police jurisdiction of the Bois de Boulogne, but private property, situated on the Rue de Longchamps, in Neuilly St James. First, I had to come to an understanding with its owner; then I had to come to an understanding with the Bois authorities, who took time to give a building permit to such an unusual construction as a house from which air-ships would go and come. The Rue de Longchamps is a narrow suburban street, little built on at this end, that gives on the Bagatelle Gate to the Bois de Boulogne, beside the training ground of the same name. To go and come in my air-ships from this side is, however, inconvenient because of the walls of the various properties, the trees that line the Bois so thickly, and the great park gates. To the right and left of my little property are other buildings. Behind me, across the Boulevard de la Seine, is the river itself, with the Ile de Puteaux in it. It is from this side that I must go and come in my air-ships. Mounting diagonally in the air from my own open grounds I pass over my wall, the Boulevard de la Seine, and turn when well above the river. Regularly I turn to the left and make my way, in a great arc, to the Bois by way of the training ground, itself a fairly open space. [Illustration: FIRST OF THE WORLD'S AIRSHIP STATIONS (NEUILLY ST JAMES)] There it stands in its grounds, the first of the air-ship stations of the future, capable of housing seven air-ships all inflated and prepared to navigate at an instant's notice! But in spite of all the needs that I attempted to provide for in it what a small and hampered place it is compared with the great, highly-organised stations which the future must produce for itself, with their high-placed and spacious landing-stages, to which air-ships will descend with complete safety and convenience, like great birds that seek nests on flat rocks! Such stations may have little car tracks running out from their interior to the wide landing-spaces. The cars that run over them will pull the air-ships in and out by their guide ropes, without loss of time or the aid of a dozen or more men. Their observation towers will serve for judges timing stations in aerial races; fitted with wireless telegraph apparatus they may be able to communicate with distant goals and, perhaps, even with the air-ships in motion. Attached to their air-ship stations there will be gas-generating plants. There may be a casemated workshop for the testing of motors. There will certainly be sleeping-rooms for experimenters who desire to make an early start and profit by the calm of the dawn. It is quite probable that there will also be balloon envelope workshops for repairs and changes, a carpenter shop, and a machine shop, with intelligent and experienced workmen ready and able to seize an idea and execute it. Meanwhile my air-ship station of the present is said to resemble a great square tent, striped red and white, set in the midst of a vacant lot surrounded by a high stone wall. Its tent-like appearance is due to the fact that, being in a hurry to utilise it, I saw no reason to construct its walls or roof of wood. The framework consists of long rows of parallel wooden pillars. Across their tops is stretched a canvas roof, and the four sides are made of the same striped canvas. This makes a construction stronger than it at first appears, the outside tent stuff weighing some 2600 kilogrammes (5720 lbs.), and being sustained between the pillars by metallic cordage. Inside, the central stalls are 9-1/2 metres (31 feet) wide, 50 metres (165 feet) long, and 13-1/2 metres (44-1/2 feet) high, affording room for the largest dirigibles without permitting them to come into contact with each other. The great sliding doors are but a repetition of those of Monaco. When in the spring of 1903 I found my air-ship station completed I had three new air-ships ready to house in it. They were: [Illustration: "No. 7"] My "No. 7." This I call my racing air-ship. It is designed and reserved for important competitions, the mere cost of filling it with hydrogen being more than 3000 francs (£120). It is true that, once filled, it may be kept inflated for a month at the expense of 50 francs (£2) per day for hydrogen to replace what is lost by the daily play of condensation and dilatation. Having a gas capacity of 1257 cubic metres (nearly 45,000 cubic feet) it possesses twice the lifting power of my "No. 6," in which the Deutsch prize was won; and such is the necessary weight of its 60 horse-power, water-cooled, four-cylinder motor and its proportionally strong machinery that I shall probably take up no more ballast in it than I took up in the "No. 6." Comparing their sizes and lifting powers, it would make five of My "No. 9," the novel little "runabout," which I shall describe in the succeeding chapter. The third of the new air-ships is My "No. 10," which has been called "The Omnibus." Its gas capacity of 2010 cubic metres (nearly 80,000 cubic feet) makes its balloon greater in size and lifting power than even the racing "No. 7"; and should I, indeed, desire at any time to shift to it the latter's keel, all furnished with the racing motor and machinery, I might combine a very swift air craft capable of carrying myself, several aids and a large supply of both petroleum and ballast--not to speak of war munitions were the sudden need of a belligerent character. The prime purpose of my "No. 10," however, is well indicated in its name: "The Omnibus." Its keel, or, rather, keels, as I have fashioned them, are double--that is to say, hanging underneath its usual keel, in which my basket is situated, there is a passenger keel that holds three similar baskets and a smaller basket for my aid. Each passenger basket is large enough to contain four passengers; and it is to carry such passengers that "The Omnibus" has been constructed. [Illustration: Fig. 13.--"No. 10" rising] [Illustration: "No. 10" WITHOUT PASSENGER KEEL] Indeed, after mature reflection, it seemed to me that this must be the most practical and rapid way to popularise aerial navigation. In my other air-ships I have shown that it is possible to mount and travel through the air on a prescribed course with no greater danger than one risks in any racing automobile. In "The Omnibus" I shall demonstrate to the world that there are very many men--and women--possessed of sufficient confidence in the aerial idea to mount with me as passengers in the first of the air omnibuses of the future. [Illustration: Fig. 14.--"No. 10" descending] CHAPTER XXII MY "NO. 9," THE LITTLE RUNABOUT Once I was enamoured of high-power petroleum automobiles: they can go at express-train speed to any part of Europe, finding fuel in any village. "I can go to Moscow or Lisbon!" I said to myself. But when I discovered that I did not want to go to Moscow or to Lisbon the small and handy electric runabout in which I do my errands about Paris and the Bois proved more satisfactory. Speaking from the standpoint of my pleasure and convenience as a Parisian my air-ship experience has been similar. When the balloon and motor of my 60 horse-power "No. 7" were completed I said to myself: [Illustration: "SANTOS-DUMONT No. 9"] "I can race any air-ship that is likely to be built!" But when I found that, in spite of the forfeits I paid into the Aéro Club's treasury, there was no one ready to race with me I determined to build a small air-ship runabout for my pleasure and convenience only. In it I would pass the time while waiting for the future to bring forth competitions worthy of my race craft. So I built my "No. 9," the smallest of possible dirigibles, yet very practical indeed. As originally constructed, its balloons capacity was but 220 cubic metres (7770 cubic feet), permitting me to take up less than 30 kilogrammes (66 lbs.) of ballast--and thus I navigated it for weeks, without inconvenience. Even when I enlarged its balloon to 261 cubic metres (9218 cubic feet) the balloon of my "No. 6," in which I won the Deutsch prize, would have made almost three of it, while that of my "Omnibus" is fully eight times its size. As I have already stated, its 3 horse-power Clement motor weighs but 12 kilogrammes (26-1/2 lbs.). With such a motor one cannot expect great speed; nevertheless, this handy little runabout takes me over the Bois at between 20 and 25 kilometres (12 and 15 miles) per hour, and this notwithstanding its egg-shaped form (Fig. 15), which would seemingly be little calculated for cutting the air. Indeed, to make it respond promptly to the rudder, I drive it thick end first. I have said that, as it was originally proportioned, the balloon of this smallest of possible dirigibles permitted me to take up less than 30 kilogrammes (66 lbs.) of ballast. As now enlarged its lifting power is greater; but when account is taken of my own weight and the weight of keel, motor, screw, and machinery, the whole system becomes neither lighter nor heavier than the surrounding atmosphere when I have loaded it with 60 kilogrammes (132 lbs.) of ballast; and it is just in this connection that it will be easiest to explain why I have called this little air-ship very practical. On Monday, 29th June 1903, I landed with it on the grounds of the Aéro Club at St Cloud in the midst of six inflated spherical balloons. After a short call I started off again. [Illustration: Fig. 15] "Can we not give you some gas?" politely asked my fellow-clubmen. [Illustration: "No. 9." SHOWING RELATIVE SIZE] "You saw me coming all the way from Neuilly," I replied; "did I throw out any ballast?" "You threw out no ballast," they admitted. "Then why should I be in need of gas?" As a matter of scientific curiosity I may relate that I did not either lose or sacrifice a cubic foot of gas or a single pound of ballast that whole afternoon--nor has that experience been at all exceptional in the very practical little "No. 9" or even in its predecessors. It will be remembered that on the day succeeding the winning of the Deutsch prize my chief mechanician found that the balloon of my "No. 6" would take no gas because none had been lost. After leaving my fellow-clubmen at St Cloud that afternoon I made a typically practical trip. To go from Neuilly St James to the Aéro Club's grounds I had already passed the Seine. Now, crossing it again, I made the café-restaurant of "The Cascade," where I stopped for refreshments. It was by this time 5 P.M. Not wishing to return yet to my station I crossed the Seine for a third time and went in a straight course as close to the great fort of Mount Valerien as delicacy permitted. Then, returning, I traversed the river once again and came to earth in my own grounds at Neuilly. During the whole trip my greatest altitude was 105 metres (346 feet). Taking into consideration that my guide rope hangs 40 metres (132 feet) below me, and that the tops of the Bois trees extend up some 20 metres (70 feet) from the ground, this extreme altitude left me but 40 metres (140 feet) of clear space for vertical manoeuvring. It was enough; and the proof of it is that I do not go higher on these trips of pleasure and experiment. Indeed, when I hear of dirigibles going up 400 metres (1300 feet) in the air without some special justifying object I am filled with amazement. As I have already explained, the place of the dirigible is, normally, in low altitudes; and the ideal is to guide-rope on a sufficiently low course to be left free from vertical manoeuvring. This is what M. Armengaud, _Jeune_, referred to in his learned inaugural discourse delivered before the Société Française de Navigation Aérienne in 1901, when he advised me to quit the Mediterranean and go guide-roping over great plains like that of La Beauce. [Illustration: "No. 9" JUMPING MY WALL] It is not necessary to go to the plain of La Beauce. One can guide-rope even in the centre of Paris if one goes about it at the proper moment. I have done it. I have guide-roped round the Arc de Triomphe and down the Avenue des Champs Elysées at as low an altitude as the house-tops on either side, fearing no ill and finding no difficulty. My first flight of this kind occurred when I sought for the first time to land in my "No. 9" in front of my own house door, at the corner of the Avenue des Champs Elysées and the Rue Washington, on Tuesday, 23rd June 1903. Knowing that the feat must be accomplished at an hour when the imposing pleasure promenade of Paris would be least encumbered, I had instructed my men to sleep through the early part of the night in the air-ship station at Neuilly St James so as to be able to have the "No. 9" ready for an early start at dawn. I myself rose at 2 A.M., and in my handy electric automobile arrived at the station while it was yet dark. The men still slept. I climbed the wall, waked them, and succeeded in quitting the earth on my first diagonally upward course over the wall and above the River Seine before the day had broken. Turning to the left, I made my way across the Bois, picking out the open spaces so as to guide-rope as much as possible. When I came to trees I jumped over them. So, navigating through the cool air of the delicious dawn, I reached the Porte Dauphine and the beginning of the broad Avenue du Bois de Boulogne, which leads directly to the Arc de Triomphe. This carriage promenade of Tout-Paris was empty. "I will guide-rope up the avenue of the Bois," I said to myself gleefully. What this means you will perceive when I recall that my guide-rope's length is barely 40 metres (132 feet), and that one guide-ropes best with at least 20 metres (66 feet) of it trailing along the ground. Thus at times I went lower than the roofs of the houses on each side. I call this practical air-ship navigation because: (_a_) It leaves the aerial navigator free to steer his course without pitching and without care or effort to maintain his steady altitude. (_b_) It can be done with absolute safety from falling, not only to the navigator, but also to the air-ship--a consideration not without its merit when the cost, both of repairs and hydrogen gas, is taken into count; and (_c_) When the wind is against one--as it was on this occasion--one finds less of it in these low altitudes. [Illustration: "No. 9." GUIDE-ROPING ON A LEVEL WITH THE HOUSETOPS] So I guide-roped up the avenue of the Bois. So, some day, will explorers guide-rope to the North Pole from their ice-locked steamship after it has reached its farthest point north. Guide-roping over the ice pack, they will make the very few hundreds of miles to the Pole at the rate of from 60 to 80 kilometres (40 to 50 miles) per hour. Even at the rate of 50 kilometres (30 miles), the trip to the Pole and back to the ship could be taken between breakfast and supper time. I do not say that they will land the first time at the Pole, but they will circle round about the spot, take observations, and return ... for supper. I might have guide-roped under the Arc de Triomphe had I thought myself worthy. Instead, I rounded the national monument to the right, as the law directs. Naturally, I had intended to go on straight down the Avenue des Champs Elysées, but here I met a difficulty. All the avenues meeting at the great "Star" look alike from the air-ship. Also, they look narrow. I was surprised and confused for a moment, and it was only by looking back to note the situation of the Arc that I could find my avenue. Like that of the Bois, it was deserted. Far down its length I saw a solitary cab. As I guide-roped along it to my house at the corner of the Rue Washington I thought of the time, sure to come, when the owners of handy little air-ships will not be obliged to land in the street, but will have their guide ropes caught by their domestics on their own roof gardens. But such roof gardens must be broad and unencumbered. So I reached my corner, to which I pointed my stem, and descended very gently. Two servants caught, steadied, and held the air-ship, while I mounted to my apartment for a cup of coffee. From my round bay window at the corner I looked down upon the air-ship. Were I to receive the municipal permission it would not be difficult to build an ornamental landing-stage out from that window. [Illustration: "No. 9." M. SANTOS-DUMONT LANDS AT HIS OWN DOOR] Projects like these will constitute work for the future. Meanwhile the aerial idea is making progress. A small boy of seven years of age has mounted with me in the "No. 9," and a charming young lady has actually navigated it alone for something like a mile. The boy will surely make an air-ship captain if he gives his mind to it. The occasion was the children's _fête_ at Bagatelle 26th June 1903. Descending among them in the "No. 9," I asked: "Does any little boy want to go up?" Such were the confidence and courage of young France and America that instantly I had to choose among a dozen volunteers. I took the nearest to me. "Are you not afraid?" I asked Clarkson Potter as the air-ship rose. "Not a bit," he answered. The cruise of the "No. 9" on this occasion was, naturally, a short one; but the other, in which the first woman to mount, accompanied or unaccompanied, in any air-ship, actually mounted alone and drove the "No. 9" free from all human contact with its guide rope for a distance of considerably over a kilometre (half-mile), is worthy of preservation in the annals of aerial navigation. The heroine, a very beautiful young Cuban lady, well known in New York society, having visited my station with her friends on several occasions, confessed an extraordinary desire to navigate the air-ship. "Would you have the courage to be taken up in the free air-ship with no one holding its guide rope?" I asked. "Mademoiselle, I thank you for the confidence." "Oh, no," she said; "I do not want to be taken up. I want to go up alone and navigate it freely, as you do." I think that the simple fact that I consented on condition that she would take a few lessons in the handling of the motor and machinery speaks eloquently in favour of my own confidence in the "No. 9." She had three such lessons, and then on 29th June 1903, a date that will be memorable in the Fasti of dirigible ballooning, rising from my station grounds in the smallest of possible dirigibles, she cried: "Let go all!" From my station at Neuilly St James she guide-roped to Bagatelle. The guide rope, trailing some 10 metres (30 feet), gave her an altitude and equilibrium that never varied. I will not say that no one ran along beside the dragging guide rope, but, certainly, no one touched it until the termination of the cruise at Bagatelle, when the moment had arrived to pull down the intrepid girl navigator. CHAPTER XXIII THE AIR-SHIP IN WAR On Saturday morning, 11th July 1903, at about 10 A.M., the wind blowing at the time in gusts, I accepted a wager to go to luncheon at the sylvan restaurant of "The Cascade" in my little "No. 9" air-ship. While the "No. 9," with its egg-shaped balloon, and motor of but 3 horse-power, was not built for speed--or, what amounts to the same thing, for battling with the wind--I thought that I could do it. Reaching my station at Neuilly St James at about 11.30 A.M. I had the little craft brought out and carefully weighed and balanced. It was in perfect condition, having lost none of its gas from the previous day. At 11.50 I started off. Fortunately, the wind came to me head-on as I steered for "The Cascade." My progress was not rapid, but I, nevertheless, met my friends on the lawn of that café-restaurant of the Bois de Boulogne at 12.30 noon. We took our luncheon, and I was preparing to depart when began an adventure that may take me far. As everybody knows, the restaurant of "The Cascade" is close to Longchamps. While we lunched, officers of the French army engaged in marking out the positions of the troops for the grand review of the 14th of July observed the air-ship on the lawn and came to inspect it. "Shall you come to the review in it?" they asked me. The year previous there had been question of such a demonstration in presence of the army, but I had hesitated for reasons that may be readily divined. After the visit of the King of England I was asked on every hand why I had not brought out the air-ship in his honour, and the same questions had arisen in anticipation of the visit of the King of Italy, who had been expected to be present at this review. I answered the officers that I could not make up my mind; that I was not sure how such an apparition would be viewed; and that my little "No. 9"--the only one of my fleet actually "in commission"--not being built for battling with high winds I could not be sure to keep an engagement in it. [Illustration: "No. 9." OVER BOIS DE BOULOGNE] "Come and choose a place to land," they said; "we will mark it out for you in any case." And, as I continued to insist on my uncertainty of being present, they very courteously picked out and marked a place for me themselves, opposite the spot to be occupied by the President of the Republic, in order that M. Loubet and his staff might have a perfect view of the air-ship's evolutions. "You will come if you can," the officers said. "You need not fear to make such a provisional engagement, for you have already given your proofs." I hope I shall not be misunderstood when I say that it may be possible that those superior officers did good work for their army and country that morning--because, in order to begin, one must make a beginning--and I should scarcely have ventured to the review without some kind of invitation. Venturing to the review, as I did in consequence, a whole train of events followed. In the early morning of 14th July 1903, as the "No. 9" was weighed and balanced, I was nervous lest some unforeseen thing might happen to it in my very grounds. One is often thus on great occasions, and I did not seek to conceal it from myself that this--the first presentation of an air-ship to any army--would be a great occasion. On ordinary days I never hesitate to mount from my grounds, over the stone wall and the river, and so on to Bagatelle. This morning I had the "No. 9" towed to the railing of Bagatelle by means of its guide rope. At 8.30 A.M. I called: "Let go all!" Rising, I found my level course at an altitude of less than 100 metres (330 feet), and in a few moments was circling and manoeuvring above the heads of the soldiers nearest to me. Thence I passed over Longchamps, and arriving opposite the president I fired a salute of twenty-one blank revolver cartridges. I did not take the place marked out for me. Fearing to disturb the good order of the review by prolonging an unusual sight I made my evolutions in the presence of the army last, all told, less than ten minutes. After this I steered for the polo grounds, where I was congratulated by numbers of my friends. [Illustration: "No. 9." AT MILITARY REVIEW, JULY 14, 1903] These congratulations I found the next day repeated in the Paris papers, together with conjectures of all kinds concerning the use of the air-ship in war. The superior officers who came to me at "The Cascade" that morning had said: "It is practical, and will have to be taken account of in war." "I am entirely at your service!" had been my answer at the time; and now, under these influences, I sat down and wrote to the Minister of War, offering, in case of hostilities with any country save those of the two Americas, to put my aerial fleet at the disposition of the Government of the Republic. In doing this I merely put into formal written words the offer which I certainly should feel bound to make in case of the breaking out of such hostilities at any future time during my residence in France. It is in France that I have met with all my encouragement; in France and with French material I have made all my experiments; and the mass of my friends are French. I excepted the two Americas because I am an American, and I added that in the impossible case of a war between France and Brazil I should feel bound to volunteer my services to the land of my birth and citizenship. A few days later I received the following letter from the French Minister of War:-- REPUBLIQUE FRANÇAISE, PARIS, _le 19 Juillet 1903_. MINISTERE DE LA GUERRE, CABINET DU MINISTRE. MONSIEUR,--During the Review of the Fourteenth of July, I had remarked and admired the ease and security with which the balloon you were steering made its evolutions. It was impossible not to acknowledge the progress which you have given to aerial navigation. It seems that, thanks to you, such navigation must, henceforward, lend itself to practical applications, especially from the military point of view. I consider that, in this respect, it may render very substantial services in time of war. I am very happy, therefore, to accept the offer which you make, of putting, in case of need, your aerial flotilla at the disposition of the Government of the Republic, and, in its name, I thank you for your gracious proposition, which shows your lively sympathy for France. I have appointed Chief of Battalion Hirschauer, commanding the Battalion of Balloonists in the First Regiment of Engineers, to examine, in agreement with you, the dispositions to take for putting the intentions you have manifested into execution. Lieutenant-Colonel Bourdeaux, Sous-Chef of my Cabinet, will also be associated with this superior officer, in order to keep me personally aware of the results of your joint labours. Recevez, Monsieur, les assurances de ma considération la plus distinguée. (Signed) General Andre. A Monsieur Alberto Santos-Dumont. On Friday, 31st July 1903, Commandant Hirschauer and Lieutenant-Colonel Bourdeaux spent the afternoon with me at my air-ship station at Neuilly St James, where I had my three newest air-ships--the racing "No. 7," the omnibus "No. 10," and the runabout "No. 9"--ready for their study. Briefly, I may say that the opinions expressed by the representatives of the Minister of War were so unreservedly favourable that a practical test of a novel character was decided to be made. Should the air-ship chosen pass successfully through it the result will be conclusive of its military value. Now that these particular experiments are leaving my exclusively private control I will say no more of them than what has been already published in the French press. The test will probably consist of an attempt to enter one of the French frontier towns, such as Belfort, or Nancy, on the same day that the air-ship leaves Paris. It will not, of course, be necessary to make the whole journey in the air-ship. A military railway waggon may be assigned to carry it, with its balloon uninflated, with tubes of hydrogen to fill it, and with all the necessary machinery and instruments arranged beside it. At some station a short distance from the town to be entered the waggon may be uncoupled from the train, and a sufficient number of soldiers accompanying the officers will unload the air-ship and its appliances, transport the whole to the nearest open space, and at once begin inflating the balloon. Within two hours from the time of quitting the train the air-ship may be ready for its flight to the interior of the technically-besieged town. Such may be the outline of the task--a task presented imperiously to French balloonists by the events of 1870-1, and which all the devotion and science of the Tissandier brothers failed to accomplish. To-day the problem may be set with better hope of success. All the essential difficulties may be revived by the marking out of a hostile zone around the town that must be entered; from beyond the outer edge of this zone, then, the air-ship will rise and take its flight--across it. Will the air-ship be able to rise out of rifle range? I have always been the first to insist that the normal place of the air-ship is in low altitudes, and I shall have written this book to little purpose if I have not shown the reader the real dangers attending any _brusque_ vertical mounting to considerable heights. For this we have the terrible Severo accident before our eyes. In particular, I have expressed astonishment at hearing of experimenters rising to these altitudes without adequate purpose in their early stages of experience with dirigible balloons. All this is very different, however, from a reasoned, cautious mounting, whose necessity has been foreseen and prepared for. To keep out of rifle range the air-ship will but seldom be obliged to make these tremendous vertical leaps. Its navigator, even at a moderate altitude, will enjoy a very extended view of the surrounding country. Thus he will be able to perceive danger afar off, and take his precautions. Even in my little "No. 9," which carries only 60 kilogrammes (132 lbs.) of ballast, I could rise, materially aided by my shifting weights and propeller, to great heights. If I have not done so it is because it would have served no useful purpose during a period of pleasure navigation, while it would but have added danger to experiments from which I have sought to eliminate all danger. Dangers like these are to be accepted only when a good cause justifies them. The experiments above named are, of course, of a nature interesting warfare by land. I cannot abandon this topic, however, without referring to one unique maritime advantage of the air-ship. This is its navigator's ability to perceive bodies moving beneath the surface of the water. Cruising at the end of its guide rope, the air-ship will carry its navigator here and there at will at the right height above the waves. Any submarine boat, stealthily pursuing its course underneath them, will be beautifully visible to him, while from a warship's deck it would be quite invisible. This is a well-observed fact, and depends on certain optical laws. Thus, very curiously, the twentieth century air-ship must become from the beginning the great enemy of that other twentieth century marvel--the submarine boat--and not only its enemy but its master. For, while the submarine boat can do no harm to the air-ship, the latter, having twice its speed, can cruise about to find it, follow all its movements, and signal them to the warships against which it is moving. Indeed, it may be able to destroy the submarine boat by sending down to it long arrows filled with dynamite, and capable of penetrating to depths underneath the waves impossible to gunnery from the decks of a warship. CHAPTER XXIV PARIS AS A CENTRE OF AIR-SHIP EXPERIMENTS After leaving Monte Carlo, in February 1902, I received many invitations from abroad to navigate my air-ships. In London, in particular, I was received with great friendliness by the Aéro Club of Great Britain, under whose auspices my "No. 6," fished from the bottom of the bay of Monaco, repaired and once again inflated, was exhibited at the Crystal Palace. From St Louis, where the organisers of the Louisiana Purchase Centennial Exposition had already decided to make air-ship flights a feature of their World's Fair in 1904, I received an invitation to inspect the grounds, suggest a course, and confer with them on conditions. As it was officially announced that a sum of 200,000 dollars had been voted and set apart for prizes it might be expected that the emulation of air-ship experimenters would be well aroused. Arriving at St Louis in the summer of 1902, I at once saw that the splendid open spaces of the Exposition Grounds offered the best of racecourses. The prevailing idea at that moment in the minds of some of the authorities was to set a long course of many hundreds of miles--say, from St Louis to Chicago. This, I pointed out, would be impracticable, if only for the reason that the Exposition public would desire to see the flights from start to finish. I suggested that three great towers or flagstaffs be erected in the grounds at the corners of an equal-sided triangle. The comparatively short course around them--between 10 and 20 miles--would afford a decisive test of dirigibility no matter in what way the wind might blow; while as for speed, the necessary average might be increased 50 per cent. over that fixed for the Deutsch prize competition in Paris. Such was my modest advice. I also thought that, out of the appropriation of 200,000 dollars (1,000,000 francs), a grand prize for dirigible aerostation of 100,000 dollars should be offered; only by means of such an inducement, it seemed to me, could the necessary emulation among air-ship experimenters be aroused. While never seeking to make profit from my air-ships, I have always offered to compete for prizes. While in London, and again in New York, both before and after my St Louis visit, competitions with prize sanctions were suggested to me for immediate effort. I accepted all of them to this point, that I had my air-ships brought to the spot at considerable cost and effort, and had the prize funds been deposited I would have done my best to win them. Such deposits failing, I, in each case, returned to my home in Paris to continue my experiments in my own way, awaiting the great competition of St Louis. Prize or no prize, I must work, and I shall always work in this my chosen field of aerostation. For this my place is Paris, where the public, in particular the kindly and enthusiastic populace, both knows and trusts me. Here, in Paris, I go up for my own pleasure day by day, as my reward for long and costly experiment. In England and America it is quite different. When I take my air-ships and my employees to those countries, build my own balloon house, furnish my own gas plant, and risk breaking machines that cost more than any automobile, I want it to be done with a settled aim. I say that I want it to be done with a settled aim, so that, if I fulfil the aim, I may no longer be criticised, at least on that particular head. Otherwise I might go to the moon and back and yet accomplish nothing in the estimation of my critics and--though, perhaps, to a less extent--in the mind of the public which they sway. Why have I sought to win prizes? Because the most rational consecration of such effort and its fulfilment is found in a serious money prize. The mind of the public makes the obvious connection. When a valuable prize is handed over it concludes that something has been done to win it. To win such prizes, then, I waited long in London and New York; but, as they never passed from words to deeds, after having enjoyed myself very thoroughly, both socially and as a tourist, I returned to my work and pleasure in the Paris which I call my home. And really, after all is said and done, there is no place like Paris for air-ship experiments. Nowhere else can the experimenter depend on the municipal and State authorities to be so liberal. Take the development of automobilism as an example. It is universally admitted, I imagine, that this great and peculiarly French industry could not have developed without the speed licence which the French authorities have wide-mindedly permitted. In spite of the most powerful social and industrial influences, and in spite of it being England's turn to offer hospitality to the James Gordon Bennett cup race of 1903, the English automobilists were not allowed to put their splendid roads out of the public use for its accommodation for a single day. So the great event had to come off in Ireland. In France, and in France only, are not only the authorities, but the great mass of citizens, so much alive to their advantage in the development of this national industry that, day by day, year in and year out, they permit ten thousand automobiles to go tearing through the highroads at a really dangerous speed. In Paris, in particular, one sees a "scorching" average in its great Park and its very avenues and streets that causes Londoners and tourists from New York to stand aghast. In this same order of ideas I may here state that, in spite of the tragic air-ship accidents of 1902, I have never once been limited or in any way impeded in the course of my experiments by the Parisian authorities; while as for the public, no matter where I land with an air-ship--in the country roads of the suburbs, in private gardens, even of great villas, in the avenues and parks and public places of the capital--I meet with unvarying friendly aid, protection, and enthusiasm. From that first memorable day when the big boys flying their kites over Bagatelle seized my guide rope and saved me from an ugly fall as promptly and intelligently as they had seized the idea of pulling me against the wind, to the critical moment on that summer day in 1901 when, in my first trial for the Deutsch prize, I descended to repair my rudder, and good-natured working-men found me a ladder in less time than it takes me to write the words--and on down to the present moment, when I take my pleasure in the Bois in my small "No. 9"--I have had nothing but unvarying friendliness from the intelligent Parisian populace. I need not say that it is a great thing for an air-ship experimenter thus to have the confidence and friendly aid of a whole population. Over certain European frontiers spherical balloons have even been shot at. And I have often wondered what kind of a reception one of my air-ships would meet with in the country districts of England itself. For these reasons, and a hundred others, I consider that my air-ship's home, like my own, is in Paris. As a boy, in Brazil, my heart turned to the City of Light, above which in 1783 the first Montgolfier had been sent up; where the first of the world's aeronauts had made his first ascension; where the first hydrogen balloon had been set loose; where first an air-ship had been made to navigate the air with its steam-engine, screw propeller, and rudder. As a youth I made my own first balloon ascension from Paris. In Paris I have found balloon constructors, motor makers, and machinists possessed not only of skill but of patience. In Paris I made all my first experiments. In Paris I won the Deutsch prize in the first dirigible to do a task against a time limit. And, now that I have not only what I call my racing air-ship but a little "runabout," in which to take my pleasure over the trees of the Bois, it is in Paris that I am enjoying my reward in it as--what I was once called reproachfully--an "aerostatic sportsman!" [Illustration: "No. 9." SEEN FROM CAPTIVE BALLOON, JUNE 11, 1903] CONCLUDING FABLE MORE REASONING OF CHILDREN During these years Luis and Pedro, the ingenious country boys whom we found reasoning of mechanical inventions in the Introductory Fable of this book, have spent some time in Paris. They were present at the winning of the Deutsch prize of aerial navigation; they spent the winter of 1901-2 at Monte Carlo; had good places at the review of the 14th July 1903; and have broadened their education by the sedulous reading of scientific weeklies and the daily newspapers. Now they are preparing to return to Brazil. The other day, seated on a café terrace of the Bois de Boulogne, they chatted of the problem of aerial navigation. "These tentatives with dirigible balloons, so called, can bring us no nearer to its solution," said Pedro. "Look you, they are filled with a substance--hydrogen--fourteen times lighter than the medium in which it floats--the atmosphere. It would be just as possible to force a tallow candle through a brick wall!" "Pedro," said Luis, "do you remember your objections to my waggon wheels?" .... "To the locomotive engine?" .... "To the steamboat?" "Our only hope to navigate the air," continued Pedro, "must, in the nature of things, be found in devices heavier than the air--in flying machines or aeroplanes. Reason by analogy. Look at the bird...." "Once you desired me to look at the fish," said Luis. "You said the steamboat ought to wriggle through the water...." "Do be serious, Luis," said Pedro in conclusive tones. "Exercise common-sense. Does man fly? No. Does the bird fly? Yes. Then, if man would fly, let him imitate the bird. Nature has made the bird. Nature never goes wrong." * * * * * Transcriber's Notes: Simple typographical errors were corrected. Punctuation and spelling were made consistent when a predominant preference was found in this book; otherwise they were not changed. 
907	----	FLYING MACHINE: CONSTRUCTION AND OPERATION By W.J. Jackman and Thos. H. Russell A Practical Book Which Shows, in Illustrations, Working Plans and Text, How to Build and Navigate the Modern Airship. W.J. JACKMAN, M.E., Author of "A B C of the Motorcycle," "Facts for Motorists," etc. etc. and THOS. H. RUSSELL, A.M., M.E., Charter Member of the Aero Club of Illinois, Author of "History of the Automobile," "Motor Boats: Construction and Operation," etc. etc. With Introductory Chapter By Octave Chanute, C.E., President Aero Club of Illinois 1912 PREFACE. This book is written for the guidance of the novice in aviation--the man who seeks practical information as to the theory, construction and operation of the modern flying machine. With this object in view the wording is intentionally plain and non-technical. It contains some propositions which, so far as satisfying the experts is concerned, might doubtless be better stated in technical terms, but this would defeat the main purpose of its preparation. Consequently, while fully aware of its shortcomings in this respect, the authors have no apologies to make. In the stating of a technical proposition so it may be clearly understood by people not versed in technical matters it becomes absolutely necessary to use language much different from that which an expert would employ, and this has been done in this volume. No man of ordinary intelligence can read this book without obtaining a clear, comprehensive knowledge of flying machine construction and operation. He will learn, not only how to build, equip, and manipulate an aeroplane in actual flight, but will also gain a thorough understanding of the principle upon which the suspension in the air of an object much heavier than the air is made possible. This latter feature should make the book of interest even to those who have no intention of constructing or operating a flying machine. It will enable them to better understand and appreciate the performances of the daring men like the Wright brothers, Curtiss, Bleriot, Farman, Paulhan, Latham, and others, whose bold experiments have made aviation an actuality. For those who wish to engage in the fascinating pastime of construction and operation it is intended as a reliable, practical guide. It may be well to explain that the sub-headings in the articles by Mr. Chanute were inserted by the authors without his knowledge. The purpose of this was merely to preserve uniformity in the typography of the book. This explanation is made in justice to Mr. Chanute. THE AUTHORS. IN MEMORIAM. Octave Chanute, "the father of the modern flying machine," died at his home in Chicago on November 23, 1910, at the age of 72 years. His last work in the interest of aviation was to furnish the introductory chapter to the first edition of this volume, and to render valuable assistance in the handling of the various subjects. He even made the trip from his home to the office of the publishers one inclement day last spring, to look over the proofs of the book and, at his suggestion, several important changes were made. All this was "a labor of love" on Mr. Chanute's part. He gave of his time and talents freely because he was enthusiastic in the cause of aviation, and because he knew the authors of this book and desired to give them material aid in the preparation of the work--a favor that was most sincerely appreciated. The authors desire to make acknowledgment of many courtesies in the way of valuable advice, information, etc., extended by Mr. Octave Chanute, C. E., Mr. E. L. Jones, Editor of Aeronautics, and the publishers of, the New England Automobile Journal and Fly. CONTENTS Chapter I. Evolution of the Two-Surface Flying Machine Introductory Chapter by Octave Chanute, C. E. II. Theory Development and Use Origin of the Aeroplane--Developments by Chanute and the Wrights--Practical Uses and Limits. III. Mechanical Bird Action What the Motor Does--Puzzle in Bird Soaring. IV. Various Forms of Flying Machines Helicopters, Ornithopters and Aeroplanes-- Monoplanes, Biplanes and Triplanes. V. Constructing a Gliding Machine Plans and Materials Required--Estimate of Cost-- Sizes and Preparation of Various Parts--Putting the Parts Together VI. Learning to Fly How to Use the Glider--Effect of Body Movements --Rules for Beginners--Safest Place to Glide. VII. Putting On the Rudder Its Construction, Application and Use. VIII. The Real Flying Machine Surface Area Required--Proper Size of Frame and Auxiliaries--Installation of Motor--Cost of Constructing Machine. IX. Selection of the Motor Essential Features--Multiplicity of Cylinders--Power Required--Kind and Action of Propellers--Placing of the Motor X. Proper Dimensions of Machines Figuring Out the Details--How to Estimate Load Capacity--Distribution of the Weight--Measurements of Leading Machines. XI. Plane and Rudder Control Various Methods in Use--Wheels and Hand and Foot Levers XII. How to Use the Machine Rules of Leading Aviators--Rising from the Ground --Reasonable Altitude--Preserving Equilibrium-- Learning to Steer. XIII. Peculiarities of Aeroplane Power Pressure of the Wind--How to Determine Upon Power--Why Speed Is Required--Bird find Flying Machine Areas. XIV. About Wind Currents, Etc. Uncertainty of Direct Force--Trouble With Gusty Currents--Why Bird Action Is Imitated. XV. The Element of Danger Risk Small Under Proper Conditions--Two Fields of Safety--Lessons in Recent Accidents. XVI. Radical Changes Being Made Results of Recent Experiments--New Dimensions --Increased Speed--The One Governing Rule. XVII. Some of the New Designs Automatic Control of Plane Stability--Inventor Herring's Devices--Novel Ideas of Students. XVIII. Demand for Flying Machines Wonderful Results in a Year--Factories Over- crowded with Orders. XIX. Law of the Airship Rights of Property Owners--Some Legal Peculiarities--Danger of Trespass. XX. Soaring Flight XXI. Flying Machines vs. Balloons XXII. Problems of Aerial Flight XXIII. Amateurs May Use Wright Patents XXIV. Hints on Propeller Construction XXV. New Motors and Devices XXVI. Monoplanes, Triplanes, Multiplanes XXVII. Records of Various Kinds FLYING MACHINES: CONSTRUCTION and OPERATION CHAPTER I. EVOLUTION OF TWO-SURFACE FLYING MACHINE. By Octave Chanute. I am asked to set forth the development of the "two-surface" type of flying machine which is now used with modifications by Wright Brothers, Farman, [1] Delagrange, Herring and others. This type originated with Mr. F. H. Wenham, who patented it in England in 1866 (No. 1571), taking out provisional papers only. In the abridgment of British patent Aeronautical Specifications (1893) it is described as follows: "Two or more aeroplanes are arranged one above the other, and support a framework or car containing the motive power. The aeroplanes are made of silk or canvas stretched on a frame by wooden rods or steel ribs. When manual power is employed the body is placed horizontally, and oars or propellers are actuated by the arms or legs. "A start may be obtained by lowering the legs and running down hill or the machine may be started from a moving carriage. One or more screw propellers may be applied for propelling when steam power is employed." On June 27, 1866, Mr. Wenham read before the "Aeronautical Society of Great Britain," then recently organized, the ablest paper ever presented to that society, and thereby breathed into it a spirit which has continued to this day. In this paper he described his observations of birds, discussed the laws governing flight as to the surfaces and power required both with wings and screws, and he then gave an account of his own experiments with models and with aeroplanes of sufficient size to carry the weight of a man. Second Wenham Aeroplane. His second aeroplane was sixteen feet from tip to tip. A trussed spar at the bottom carried six superposed bands of thin holland fabric fifteen inches wide, connected with vertical webs of holland two feet apart, thus virtually giving a length of wing of ninety-six feet and one hundred and twenty square feet of supporting surface. The man was placed horizontally on a base board beneath the spar. This apparatus when tried in the wind was found to be unmanageable by reason of the fluttering motions of the fabric, which was insufficiently stiffened with crinoline steel, but Mr. Wenham pointed out that this in no way invalidated the principle of the apparatus, which was to obtain large supporting surfaces without increasing unduly the leverage and consequent weight of spar required, by simply superposing the surfaces. This principle is entirely sound and it is surprising that it is, to this day, not realized by those aviators who are hankering for monoplanes. Experiments by Stringfellow. The next man to test an apparatus with superposed surfaces was Mr. Stringfellow, who, becoming much impressed with Mr. Wenham's proposal, produced a largish model at the exhibition of the Aeronautical Society in 1868. It consisted of three superposed surfaces aggregating 28 square feet and a tail of 8 square feet more. The weight was under 12 pounds and it was driven by a central propeller actuated by a steam engine overestimated at one-third of a horsepower. It ran suspended to a wire on its trials but failed of free flight, in consequence of defective equilibrium. This apparatus has since been rebuilt and is now in the National Museum of the Smithsonian Institution at Washington. Linfield's Unsuccessful Efforts. In 1878 Mr. Linfield tested an apparatus in England consisting of a cigar-shaped car, to which was attached on each side frames five feet square, containing each twenty-five superposed planes of stretched and varnished linen eighteen inches wide, and only two inches apart, thus reminding one of a Spanish donkey with panniers. The whole weighed two hundred and forty pounds. This was tested by being mounted on a flat car behind a locomotive going 40 miles an hour. When towed by a line fifteen feet long the apparatus rose only a little from the car and exhibited such unstable equilibrium that the experiment was not renewed. The lift was only about one-third of what it would have been had the planes been properly spaced, say their full width apart, instead of one-ninth as erroneously devised. Renard's "Dirigible Parachute." In 1889 Commandant Renard, the eminent superintendent of the French Aeronautical Department, exhibited at the Paris Exposition of that year, an apparatus experimented with some years before, which he termed a "dirigible parachute." It consisted of an oviform body to which were pivoted two upright slats carrying above the body nine long superposed flat blades spaced about one-third of their width apart. When this apparatus was properly set at an angle to the longitudinal axis of the body and dropped from a balloon, it travelled back against the wind for a considerable distance before alighting. The course could be varied by a rudder. No practical application seems to have been made of this device by the French War Department, but Mr. J. P. Holland, the inventor of the submarine boat which bears his name, proposed in 1893 an arrangement of pivoted framework attached to the body of a flying machine which combines the principle of Commandant Renard with the curved blades experimented with by Mr. Phillips, now to be noticed, with the addition of lifting screws inserted among the blades. Phillips Fails on Stability Problem. In 1893 Mr. Horatio Phillips, of England, after some very interesting experiments with various wing sections, from which he deduced conclusions as to the shape of maximum lift, tested an apparatus resembling a Venetian blind which consisted of fifty wooden slats of peculiar shape, 22 feet long, one and a half inches wide, and two inches apart, set in ten vertical upright boards. All this was carried upon a body provided with three wheels. It weighed 420 pounds and was driven at 40 miles an hour on a wooden sidewalk by a steam engine of nine horsepower which actuated a two-bladed screw. The lift was satisfactory, being perhaps 70 pounds per horsepower, but the equilibrium was quite bad and the experiments were discontinued. They were taken up again in 1904 with a similar apparatus large enough to carry a passenger, but the longitudinal equilibrium was found to be defective. Then in 1907 a new machine was tested, in which four sets of frames, carrying similar sets of slat "sustainers" were inserted, and with this arrangement the longitudinal stability was found to be very satisfactory. The whole apparatus, with the operator, weighed 650 pounds. It flew about 200 yards when driven by a motor of 20 to 22 h.p. at 30 miles an hour, thus exhibiting a lift of about 32 pounds per h.p., while it will be remembered that the aeroplane of Wright Brothers exhibits a lifting capacity of 50 pounds to the h.p. Hargrave's Kite Experiments. After experimenting with very many models and building no less than eighteen monoplane flying model machines, actuated by rubber, by compressed air and by steam, Mr. Lawrence Hargrave, of Sydney, New South Wales, invented the cellular kite which bears his name and made it known in a paper contributed to the Chicago Conference on Aerial Navigation in 1893, describing several varieties. The modern construction is well known, and consists of two cells, each of superposed surfaces with vertical side fins, placed one behind the other and connected by a rod or frame. This flies with great steadiness without a tail. Mr. Hargrave's idea was to use a team of these kites, below which he proposed to suspend a motor and propeller from which a line would be carried to an anchor in the ground. Then by actuating the propeller the whole apparatus would move forward, pick up the anchor and fly away. He said: "The next step is clear enough, namely, that a flying machine with acres of surface can be safely got under way or anchored and hauled to the ground by means of the string of kites." The first tentative experiments did not result well and emphasized the necessity for a light motor, so that Mr. Hargrave has since been engaged in developing one, not having convenient access to those which have been produced by the automobile designers and builders. Experiments With Glider Model. And here a curious reminiscence may be indulged in. In 1888 the present writer experimented with a two-cell gliding model, precisely similar to a Hargrave kite, as will be confirmed by Mr. Herring. It was frequently tested by launching from the top of a three-story house and glided downward very steadily in all sorts of breezes, but the angle of descent was much steeper than that of birds, and the weight sustained per square foot was less than with single cells, in consequence of the lesser support afforded by the rear cell, which operated upon air already set in motion downward by the front cell, so nothing more was done with it, for it never occurred to the writer to try it as a kite and he thus missed the distinction which attaches to Hargrave's name. Sir Hiram Maxim also introduced fore and aft superposed surfaces in his wondrous flying machine of 1893, but he relied chiefly for the lift upon his main large surface and this necessitated so many guys, to prevent distortion, as greatly to increase the head resistance and this, together with the unstable equilibrium, made it evident that the design of the machine would have to be changed. How Lilienthal Was Killed. In 1895, Otto Lilienthal, the father of modern aviation, the man to whose method of experimenting almost all present successes are due, after making something like two thousand glides with monoplanes, added a superposed surface to his apparatus and found the control of it much improved. The two surfaces were kept apart by two struts or vertical posts with a few guy wires, but the connecting joints were weak and there was nothing like trussing. This eventually cost his most useful life. Two weeks before that distressing loss to science, Herr Wilhelm Kress, the distinguished and veteran aviator of Vienna, witnessed a number of glides by Lilienthal with his double-decked apparatus. He noticed that it was much wracked and wobbly and wrote to me after the accident: "The connection of the wings and the steering arrangement were very bad and unreliable. I warned Herr Lilienthal very seriously. He promised me that he would soon put it in order, but I fear that he did not attend to it immediately." In point of fact, Lilienthal had built a new machine, upon a different principle, from which he expected great results, and intended to make but very few more flights with the old apparatus. He unwisely made one too many and, like Pilcher, was the victim of a distorted apparatus. Probably one of the joints of the struts gave way, the upper surface blew back and Lilienthal, who was well forward on the lower surface, was pitched headlong to destruction. Experiments by the Writer. In 1896, assisted by Mr. Herring and Mr. Avery, I experimented with several full sized gliding machines, carrying a man. The first was a Lilienthal monoplane which was deemed so cranky that it was discarded after making about one hundred glides, six weeks before Lilienthal's accident. The second was known as the multiple winged machine and finally developed into five pairs of pivoted wings, trussed together at the front and one pair in the rear. It glided at angles of descent of 10 or 11 degrees or of one in five, and this was deemed too steep. Then Mr. Herring and myself made computations to analyze the resistances. We attributed much of them to the five front spars of the wings and on a sheet of cross-barred paper I at once drew the design for a new three-decked machine to be built by Mr. Herring. Being a builder of bridges, I trussed these surfaces together, in order to obtain strength and stiffness. When tested in gliding flight the lower surface was found too near the ground. It was taken off and the remaining apparatus now consisted of two surfaces connected together by a girder composed of vertical posts and diagonal ties, specifically known as a "Pratt truss." Then Mr. Herring and Mr. Avery together devised and put on an elastic attachment to the tail. This machine proved a success, it being safe and manageable. Over 700 glides were made with it at angles of descent of 8 to 10 degrees, or one in six to one in seven. First Proposed by Wenham. The elastic tail attachment and the trussing of the connecting frame of the superposed wings were the only novelties in this machine, for the superposing of the surfaces had first been proposed by Wenham, but in accordance with the popular perception, which bestows all the credit upon the man who adds the last touch making for success to the labors of his predecessors, the machine has since been known by many persons as the "Chanute type" of gliders, much to my personal gratification. It has since been improved in many ways. Wright Brothers, disregarding the fashion which prevails among birds, have placed the tail in front of their apparatus and called it a front rudder, besides placing the operator in horizontal position instead of upright, as I did; and also providing a method of warping the wings to preserve equilibrium. Farman and Delagrange, under the very able guidance and constructive work of Voisin brothers, then substituted many details, including a box tail for the dart-like tail which I used. This may have increased the resistance, but it adds to the steadiness. Now the tendency in France seems to be to go back to the monoplane. Monoplane Idea Wrong. The advocates of the single supporting surface are probably mistaken. It is true that a single surface shows a greater lift per square foot than superposed surfaces for a given speed, but the increased weight due to leverage more than counterbalances this advantage by requiring heavy spars and some guys. I believe that the future aeroplane dynamic flier will consist of superposed surfaces, and, now that it has been found that by imbedding suitably shaped spars in the cloth the head resistance may be much diminished, I see few objections to superposing three, four or even five surfaces properly trussed, and thus obtaining a compact, handy, manageable and comparatively light apparatus. [2] CHAPTER II. THEORY, DEVELOPMENT, AND USE. While every craft that navigates the air is an airship, all airships are not flying machines. The balloon, for instance, is an airship, but it is not what is known among aviators as a flying machine. This latter term is properly used only in referring to heavier-than-air machines which have no gas-bag lifting devices, and are made to really fly by the application of engine propulsion. Mechanical Birds. All successful flying machines--and there are a number of them--are based on bird action. The various designers have studied bird flight and soaring, mastered its technique as devised by Nature, and the modern flying machine is the result. On an exaggerated, enlarged scale the machines which are now navigating the air are nothing more nor less than mechanical birds. Origin of the Aeroplane. Octave Chanute, of Chicago, may well be called "the developer of the flying machine." Leaving balloons and various forms of gas-bags out of consideration, other experimenters, notably Langley and Lilienthal, antedated him in attempting the navigation of the air on aeroplanes, or flying machines, but none of them were wholly successful, and it remained for Chanute to demonstrate the practicability of what was then called the gliding machine. This term was adopted because the apparatus was, as the name implies, simply a gliding machine, being without motor propulsion, and intended solely to solve the problem of the best form of construction. The biplane, used by Chanute in 1896, is still the basis of most successful flying machines, the only radical difference being that motors, rudders, etc., have been added. Character of Chanute's Experiments. It was the privilege of the author of this book to be Mr. Chanute's guest at Millers, Indiana, in 1896, when, in collaboration with Messrs. Herring and Avery, he was conducting the series of experiments which have since made possible the construction of the modern flying machine which such successful aviators as the Wright brothers and others are now using. It was a wild country, much frequented by eagles, hawks, and similar birds. The enthusiastic trio, Chanute, Herring and Avery, would watch for hours the evolutions of some big bird in the air, agreeing in the end on the verdict, "When we master the principle of that bird's soaring without wing action, we will have come close to solving the problem of the flying machine." Aeroplanes of various forms were constructed by Mr. Chanute with the assistance of Messrs. Herring and Avery until, at the time of the writer's visit, they had settled upon the biplane, or two-surface machine. Mr. Herring later equipped this with a rudder, and made other additions, but the general idea is still the basis of the Wright, Curtiss, and other machines in which, by the aid of gasolene motors, long flights have been made. Developments by the Wrights. In 1900 the Wright brothers, William and Orville, who were then in the bicycle business in Dayton, Ohio, became interested in Chanute's experiments and communicated with him. The result was that the Wrights took up Chanute's ideas and developed them further, making many additions of their own, one of which was the placing of a rudder in front, and the location of the operator horizontally on the machine, thus diminishing by four-fifths the wind resistance of the man's body. For three years the Wrights experimented with the glider before venturing to add a motor, which was not done until they had thoroughly mastered the control of their movements in the air. Limits of the Flying Machine. In the opinion of competent experts it is idle to look for a commercial future for the flying machine. There is, and always will be, a limit to its carrying capacity which will prohibit its employment for passenger or freight purposes in a wholesale or general way. There are some, of course, who will argue that because a machine will carry two people another may be constructed that will carry a dozen, but those who make this contention do not understand the theory of weight sustentation in the air; or that the greater the load the greater must be the lifting power (motors and plane surface), and that there is a limit to these--as will be explained later on--beyond which the aviator cannot go. Some Practical Uses. At the same time there are fields in which the flying machine may be used to great advantage. These are: Sports--Flying machine races or flights will always be popular by reason of the element of danger. It is a strange, but nevertheless a true proposition, that it is this element which adds zest to all sporting events. Scientific--For exploration of otherwise inaccessible regions such as deserts, mountain tops, etc. Reconnoitering--In time of war flying machines may be used to advantage to spy out an enemy's encampment, ascertain its defenses, etc. CHAPTER III. MECHANICAL BIRD ACTION In order to understand the theory of the modern flying machine one must also understand bird action and wind action. In this connection the following simple experiment will be of interest: Take a circular-shaped bit of cardboard, like the lid of a hat box, and remove the bent-over portion so as to have a perfectly flat surface with a clean, sharp edge. Holding the cardboard at arm's length, withdraw your hand, leaving the cardboard without support. What is the result? The cardboard, being heavier than air, and having nothing to sustain it, will fall to the ground. Pick it up and throw it, with considerable force, against the wind edgewise. What happens? Instead of falling to the ground, the cardboard sails along on the wind, remaining afloat so long as it is in motion. It seeks the ground, by gravity, only as the motion ceases, and then by easy stages, instead of dropping abruptly as in the first instance. Here we have a homely, but accurate illustration of the action of the flying machine. The motor does for the latter what the force of your arm does for the cardboard--imparts a motion which keeps it afloat. The only real difference is that the motion given by the motor is continuous and much more powerful than that given by your arm. The action of the latter is limited and the end of its propulsive force is reached within a second or two after it is exerted, while the action of the motor is prolonged. Another Simple Illustration. Another simple means of illustrating the principle of flying machine operation, so far as sustentation and the elevation and depression of the planes is concerned, is explained in the accompanying diagram. A is a piece of cardboard about 2 by 3 inches in size. B is a piece of paper of the same size pasted to one edge of A. If you bend the paper to a curve, with convex side up and blow across it as shown in Figure C, the paper will rise instead of being depressed. The dotted lines show that the air is passing over the top of the curved paper and yet, no matter how hard you may blow, the effect will be to elevate the paper, despite the fact that the air is passing over, instead of under the curved surface. In Figure D we have an opposite effect. Here the paper is in a curve exactly the reverse of that shown in Figure C, bringing the concave side up. Now if you will again blow across the surface of the card the action of the paper will be downward--it will be impossible to make it rise. The harder you blow the greater will be the downward movement. Principle In General Use. This principle is taken advantage of in the construction of all successful flying machines. Makers of monoplanes and biplanes alike adhere to curved bodies, with the concave surface facing downward. Straight planes were tried for a time, but found greatly lacking in the power of sustentation. By curving the planes, and placing the concave surface downward, a sort of inverted bowl is formed in which the air gathers and exerts a buoyant effect. Just what the ratio of the curve should be is a matter of contention. In some instances one inch to the foot is found to be satisfactory; in others this is doubled, and there are a few cases in which a curve of as much as 3 inches to the foot has been used. Right here it might be well to explain that the word "plane" applied to flying machines of modern construction is in reality a misnomer. Plane indicates a flat, level surface. As most successful flying machines have curved supporting surfaces it is clearly wrong to speak of "planes," or "aeroplanes." Usage, however, has made the terms convenient and, as they are generally accepted and understood by the public, they are used in like manner in this volume. Getting Under Headway. A bird, on first rising from the ground, or beginning its flight from a tree, will flap its wings to get under headway. Here again we have another illustration of the manner in which a flying machine gets under headway--the motor imparts the force necessary to put the machine into the air, but right here the similarity ceases. If the machine is to be kept afloat the motor must be kept moving. A flying machine will not sustain itself; it will not remain suspended in the air unless it is under headway. This is because it is heavier than air, and gravity draws it to the ground. Puzzle in Bird Soaring. But a bird, which is also heavier than air, will remain suspended, in a calm, will even soar and move in a circle, without apparent movement of its wings. This is explained on the theory that there are generally vertical columns of air in circulation strong enough to sustain a bird, but much too weak to exert any lifting power on a flying machine, It is easy to understand how a bird can remain suspended when the wind is in action, but its suspension in a seeming dead calm was a puzzle to scientists until Mr. Chanute advanced the proposition of vertical columns of air. Modeled Closely After Birds. So far as possible, builders of flying machines have taken what may be called "the architecture" of birds as a model. This is readily noticeable in the form of construction. When a bird is in motion its wings (except when flapping) are extended in a straight line at right angles to its body. This brings a sharp, thin edge against the air, offering the least possible surface for resistance, while at the same time a broad surface for support is afforded by the flat, under side of the wings. Identically the same thing is done in the construction of the flying machine. Note, for instance, the marked similarity in form as shown in the illustration in Chapter II. Here A is the bird, and B the general outline of the machine. The thin edge of the plane in the latter is almost a duplicate of that formed by the outstretched wings of the bird, while the rudder plane in the rear serves the same purpose as the bird's tail. CHAPTER IV. VARIOUS FORMS OF FLYING MACHINES. There are three distinct and radically different forms of flying machines. These are: Aeroplanes, helicopters and ornithopers. Of these the aeroplane takes precedence and is used almost exclusively by successful aviators, the helicopters and ornithopers having been tried and found lacking in some vital features, while at the same time in some respects the helicopter has advantages not found in the aeroplane. What the Helicopter Is. The helicopter gets its name from being fitted with vertical propellers or helices (see illustration) by the action of which the machine is raised directly from the ground into the air. This does away with the necessity for getting the machine under a gliding headway before it floats, as is the case with the aeroplane, and consequently the helicopter can be handled in a much smaller space than is required for an aeroplane. This, in many instances, is an important advantage, but it is the only one the helicopter possesses, and is more than overcome by its drawbacks. The most serious of these is that the helicopter is deficient in sustaining capacity, and requires too much motive power. Form of the Ornithopter. The ornithopter has hinged planes which work like the wings of a bird. At first thought this would seem to be the correct principle, and most of the early experimenters conducted their operations on this line. It is now generally understood, however, that the bird in soaring is in reality an aeroplane, its extended wings serving to sustain, as well as propel, the body. At any rate the ornithoper has not been successful in aviation, and has been interesting mainly as an ingenious toy. Attempts to construct it on a scale that would permit of its use by man in actual aerial flights have been far from encouraging. Three Kinds of Aeroplanes. There are three forms of aeroplanes, with all of which more or less success has been attained. These are: The monoplane, a one-surfaced plane, like that used by Bleriot. The biplane, a two-surfaced plane, now used by the Wrights, Curtiss, Farman, and others. The triplane, a three-surfaced plane This form is but little used, its only prominent advocate at present being Elle Lavimer, a Danish experimenter, who has not thus far accomplished much. Whatever of real success has been accomplished in aviation may be credited to the monoplane and biplane, with the balance in favor of the latter. The monoplane is the more simple in construction and, where weight-sustaining capacity is not a prime requisite, may probably be found the most convenient. This opinion is based on the fact that the smaller the surface of the plane the less will be the resistance offered to the air, and the greater will be the speed at which the machine may be moved. On the other hand, the biplane has a much greater plane surface (double that of a monoplane of the same size) and consequently much greater weight-carrying capacity. Differences in Biplanes. While all biplanes are of the same general construction so far as the main planes are concerned, each aviator has his own ideas as to the "rigging." Wright, for instance, places a double horizontal rudder in front, with a vertical rudder in the rear. There are no partitions between the main planes, and the bicycle wheels used on other forms are replaced by skids. Voisin, on the contrary, divides the main planes with vertical partitions to increase stability in turning; uses a single-plane horizontal rudder in front, and a big box-tail with vertical rudder at the rear; also the bicycle wheels. Curtiss attaches horizontal stabilizing surfaces to the upper plane; has a double horizontal rudder in front, with a vertical rudder and horizontal stabilizing surfaces in rear. Also the bicycle wheel alighting gear. CHAPTER V. CONSTRUCTING A GLIDING MACHINE. First decide upon the kind of a machine you want--monoplane, biplane, or triplane. For a novice the biplane will, as a rule, be found the most satisfactory as it is more compact and therefore the more easily handled. This will be easily understood when we realize that the surface of a flying machine should be laid out in proportion to the amount of weight it will have to sustain. The generally accepted rule is that 152 square feet of surface will sustain the weight of an average-sized man, say 170 pounds. Now it follows that if these 152 square feet of surface are used in one plane, as in the monoplane, the length and width of this plane must be greater than if the same amount of surface is secured by using two planes--the biplane. This results in the biplane being more compact and therefore more readily manipulated than the monoplane, which is an important item for a novice. Glider the Basis of Success. Flying machines without motors are called gliders. In making a flying machine you first construct the glider. If you use it in this form it remains a glider. If you install a motor it becomes a flying machine. You must have a good glider as the basis of a successful flying machine. It will be well for the novice, the man who has never had any experience as an aviator, to begin with a glider and master its construction and operation before he essays the more pretentious task of handling a fully-equipped flying machine. In fact, it is essential that he should do so. Plans for Handy Glider. A glider with a spread (advancing edge) of 20 feet, and a breadth or depth of 4 feet, will be about right to begin with. Two planes of this size will give the 152 square yards of surface necessary to sustain a man's weight. Remember that in referring to flying machine measurements "spread" takes the place of what would ordinarily be called "length," and invariably applies to the long or advancing edge of the machine which cuts into the air. Thus, a glider is spoken of as being 20 feet spread, and 4 feet in depth. So far as mastering the control of the machine is concerned, learning to balance one's self in the air, guiding the machine in any desired direction by changing the position of the body, etc., all this may be learned just as readily, and perhaps more so, with a 20-foot glider than with a larger apparatus. Kind of Material Required. There are three all-important features in flying machine construction, viz.: lightness, strength and extreme rigidity. Spruce is the wood generally used for glider frames. Oak, ash and hickory are all stronger, but they are also considerably heavier, and where the saving of weight is essential, the difference is largely in favor of spruce. This will be seen in the following table: Weight Tensile Compressive per cubic ft. Strength Strength Wood in lbs. lbs. per sq. in. lbs. per sq in. Hickory 53 12,000 8,500 Oak 50 12,000 9,000 Ash 38 12,000 6,000 Walnut 38 8,000 6,000 Spruce 25 8,000 5,000 Pine 25 5,000 4,500 Considering the marked saving in weight spruce has a greater percentage of tensile strength than any of the other woods. It is also easier to find in long, straight-grained pieces free from knots, and it is this kind only that should be used in flying machine construction. You will next need some spools or hanks of No. 6 linen shoe thread, metal sockets, a supply of strong piano wire, a quantity of closely-woven silk or cotton cloth, glue, turnbuckles, varnish, etc. Names of the Various Parts. The long strips, four in number, which form the front and rear edges of the upper and lower frames, are called the horizontal beams. These are each 20 feet in length. These horizontal beams are connected by upright strips, 4 feet long, called stanchions. There are usually 12 of these, six on the front edge, and six on the rear. They serve to hold the upper plane away from the lower one. Next comes the ribs. These are 4 feet in length (projecting for a foot over the rear beam), and while intended principally as a support to the cloth covering of the planes, also tend to hold the frame together in a horizontal position just as the stanchions do in the vertical. There are forty-one of these ribs, twenty-one on the upper and twenty on the lower plane. Then come the struts, the main pieces which join the horizontal beams. All of these parts are shown in the illustrations, reference to which will make the meaning of the various names clear. Quantity and Cost of Material. For the horizontal beams four pieces of spruce, 20 feet long, 1 1/2 inches wide and 3/4 inch thick are necessary. These pieces must be straight-grain, and absolutely free from knots. If it is impossible to obtain clear pieces of this length, shorter ones may be spliced, but this is not advised as it adds materially to the weight. The twelve stanchions should be 4 feet long and 7/8 inch in diameter and rounded in form so as to offer as little resistance as possible to the wind. The struts, there are twelve of them, are 3 feet long by 11/4 x 1/2 inch. For a 20-foot biplane about 20 yards of stout silk or unbleached muslin, of standard one yard width, will be needed. The forty-one ribs are each 4 feet long, and 1/2 inch square. A roll of No. 12 piano wire, twenty-four sockets, a package of small copper tacks, a pot of glue, and similar accessories will be required. The entire cost of this material should not exceed $20. The wood and cloth will be the two largest items, and these should not cost more than $10. This leaves $10 for the varnish, wire, tacks, glue, and other incidentals. This estimate is made for cost of materials only, it being taken for granted that the experimenter will construct his own glider. Should the services of a carpenter be required the total cost will probably approximate $60 or $70. Application of the Rudders. The figures given also include the expense of rudders, but the details of these have not been included as the glider is really complete without them. Some of the best flights the writer ever saw were made by Mr. A. M. Herring in a glider without a rudder, and yet there can be no doubt that a rudder, properly proportioned and placed, especially a rear rudder, is of great value to the aviator as it keeps the machine with its head to the wind, which is the only safe position for a novice. For initial educational purposes, however, a rudder is not essential as the glides will, or should, be made on level ground, in moderate, steady wind currents, and at a modest elevation. The addition of a rudder, therefore, may well be left until the aviator has become reasonably expert in the management of his machine. Putting the Machine Together. Having obtained the necessary material, the first move is to have the rib pieces steamed and curved. This curve may be slight, about 2 inches for the 4 feet. While this is being done the other parts should be carefully rounded so the square edges will be taken off. This may be done with sand paper. Next apply a coat of shellac, and when dry rub it down thoroughly with fine sand paper. When the ribs are curved treat them in the same way. Lay two of the long horizontal frame pieces on the floor 3 feet apart. Between these place six of the strut pieces. Put one at each end, and each 4 1/2 feet put another, leaving a 2-foot space in the center. This will give you four struts 4 1/2 feet apart, and two in the center 2 feet apart, as shown in the illustration. This makes five rectangles. Be sure that the points of contact are perfect, and that the struts are exactly at right angles with the horizontal frames. This is a most important feature because if your frame "skews" or twists you cannot keep it straight in the air. Now glue the ends of the struts to the frame pieces, using plenty of glue, and nail on strips that will hold the frame in place while the glue is drying. The next day lash the joints together firmly with the shoe thread, winding it as you would to mend a broken gun stock, and over each layer put a coating of glue. This done, the other frame pieces and struts may be treated in the same way, and you will thus get the foundations for the two planes. Another Way of Placing Struts. In the machines built for professional use a stronger and more certain form of construction is desired. This is secured by the placing the struts for the lower plane under the frame piece, and those for the upper plane over it, allowing them in each instance to come out flush with the outer edges of the frame pieces. They are then securely fastened with a tie plate or clamp which passes over the end of the strut and is bound firmly against the surface of the frame piece by the eye bolts of the stanchion sockets. Placing the Rib Pieces. Take one of the frames and place on it the ribs, with the arched side up, letting one end of the ribs come flush with the front edge of the forward frame, and the other end projecting about a foot beyond the rear frame. The manner of fastening the ribs to the frame pieces is optional. In some cases they are lashed with shoe thread, and in others clamped with a metal clamp fastened with 1/2-inch wood screws. Where clamps and screws are used care should be taken to make slight holes in the wood with an awl before starting the screws so as to lessen any tendency to split the wood. On the top frame, twenty-one ribs placed one foot apart will be required. On the lower frame, because of the opening left for the operator's body, you will need only twenty. Joining the Two Frames. The two frames must now be joined together. For this you will need twenty-four aluminum or iron sockets which may be purchased at a foundry or hardware shop. These sockets, as the name implies, provide a receptacle in which the end of a stanchion is firmly held, and have flanges with holes for eye-bolts which hold them firmly to the frame pieces, and also serve to hold the guy wires. In addition to these eye-bolt holes there are two others through which screws are fastened into the frame pieces. On the front frame piece of the bottom plane place six sockets, beginning at the end of the frame, and locating them exactly opposite the struts. Screw the sockets into position with wood screws, and then put the eye-bolts in place. Repeat the operation on the rear frame. Next put the sockets for the upper plane frame in place. You are now ready to bring the two planes together. Begin by inserting the stanchions in the sockets in the lower plane. The ends may need a little rubbing with sandpaper to get them into the sockets, but care must be taken to have them fit snugly. When all the stanchions are in place on the lower plane, lift the upper plane into position, and fit the sockets over the upper ends of the stanchions. Trussing with Guy Wires. The next move is to "tie" the frame together rigidly by the aid of guy wires. This is where the No. 12 piano wire comes in. Each rectangle formed by the struts and stanchions with the exception of the small center one, is to be wired separately as shown in the illustration. At each of the eight corners forming the rectangle the ring of one of the eye-bolts will be found. There are two ways of doing this "tieing," or trussing. One is to run the wires diagonally from eye-bolt to eye-bolt, depending upon main strength to pull them taut enough, and then twist the ends so as to hold. The other is to first make a loop of wire at each eye-bolt, and connect these loops to the main wires with turn-buckles. This latter method is the best, as it admits of the tension being regulated by simply turning the buckle so as to draw the ends of the wire closer together. A glance at the illustration will make this plain, and also show how the wires are to be placed. The proper degree of tension may be determined in the following manner: After the frame is wired place each end on a saw-horse so as to lift the entire frame clear of the work-shop floor. Get under it, in the center rectangle and, grasping the center struts, one in each hand, put your entire weight on the structure. If it is properly put together it will remain rigid and unyielding. Should it sag ever so slightly the tension of the wires must be increased until any tendency to sag, no matter how slight it may be, is overcome. Putting on the Cloth. We are now ready to put on the cloth covering which holds the air and makes the machine buoyant. The kind of material employed is of small account so long as it is light, strong, and wind-proof, or nearly so. Some aviators use what is called rubberized silk, others prefer balloon cloth. Ordinary muslin of good quality, treated with a coat of light varnish after it is in place, will answer all the purposes of the amateur. Cut the cloth into strips a little over 4 feet in length. As you have 20 feet in width to cover, and the cloth is one yard wide, you will need seven strips for each plane, so as to allow for laps, etc. This will give you fourteen strips. Glue the end of each strip around the front horizontal beams of the planes, and draw each strip back, over the ribs, tacking the edges to the ribs as you go along, with small copper or brass tacks. In doing this keep the cloth smooth and stretched tight. Tacks should also be used in addition to the glue, to hold the cloth to the horizontal beams. Next, give the cloth a coat of varnish on the clear, or upper side, and when this is dry your glider will be ready for use. Reinforcing the Cloth. While not absolutely necessary for amateur purposes, reinforcement of the cloth, so as to avoid any tendency to split or tear out from wind-pressure, is desirable. One way of doing this is to tack narrow strips of some heavier material, like felt, over the cloth where it laps on the ribs. Another is to sew slips or pockets in the cloth itself and let the ribs run through them. Still another method is to sew 2-inch strips (of the same material as the cover) on the cloth, placing them about one yard apart, but having them come in the center of each piece of covering, and not on the laps where the various pieces are joined. Use of Armpieces. Should armpieces be desired, aside from those afforded by the center struts, take two pieces of spruce, 3 feet long, by 1 x 1 3/4 inches, and bolt them to the front and rear beams of the lower plane about 14 inches apart. These will be more comfortable than using the struts, as the operator will not have to spread his arms so much. In using the struts the operator, as a rule, takes hold of them with his hands, while with the armpieces, as the name implies, he places his arms over them, one of the strips coming under each armpit. Frequently somebody asks why the ribs should be curved. The answer is easy. The curvature tends to direct the air downward toward the rear and, as the air is thus forced downward, there is more or less of an impact which assists in propelling the aeroplane upwards. CHAPTER VI. LEARNING TO FLY. Don't be too ambitious at the start. Go slow, and avoid unnecessary risks. At its best there is an element of danger in aviation which cannot be entirely eliminated, but it may be greatly reduced and minimized by the use of common sense. Theoretically, the proper way to begin a glide is from the top of an incline, facing against the wind, so that the machine will soar until the attraction of gravitation draws it gradually to the ground. This is the manner in which experienced aviators operate, but it must be kept in mind that these men are experts. They understand air currents, know how to control the action and direction of their machines by shifting the position of their bodies, and by so doing avoid accidents which would be unavoidable by a novice. Begin on Level Ground. Make your first flights on level ground, having a couple of men to assist you in getting the apparatus under headway. Take your position in the center rectangle, back far enough to give the forward edges of the glider an inclination to tilt upward very slightly. Now start and run forward at a moderately rapid gait, one man at each end of the glider assisting you. As the glider cuts into the air the wind will catch under the uplifted edges of the curved planes, and buoy it up so that it will rise in the air and take you with it. This rise will not be great, just enough to keep you well clear of the ground. Now project your legs a little to the front so as to shift the center of gravity a trifle and bring the edges of the glider on an exact level with the atmosphere. This, with the momentum acquired in the start, will keep the machine moving forward for some distance. Effect of Body Movements. When the weight of the body is slightly back of the center of gravity the edges of the advancing planes are tilted slightly upward. The glider in this position acts as a scoop, taking in the air which, in turn, lifts it off the ground. When a certain altitude is reached--this varies with the force of the wind--the tendency to a forward movement is lost and the glider comes to the ground. It is to prolong the forward movement as much as possible that the operator shifts the center of gravity slightly, bringing the apparatus on an even keel as it were by lowering the advancing edges. This done, so long as there is momentum enough to keep the glider moving, it will remain afloat. If you shift your body well forward it will bring the front edges of the glider down, and elevate the rear ones. In this way the air will be "spilled" out at the rear, and, having lost the air support or buoyancy, the glider comes down to the ground. A few flights will make any ordinary man proficient in the control of his apparatus by his body movements, not only as concerns the elevating and depressing of the advancing edges, but also actual steering. You will quickly learn, for instance, that, as the shifting of the bodily weight backwards and forwards affects the upward and downward trend of the planes, so a movement sideways--to the left or the right--affects the direction in which the glider travels. Ascends at an Angle. In ascending, the glider and flying machine, like the bird, makes an angular, not a vertical flight. Just what this angle of ascension may be is difficult to determine. It is probable and in fact altogether likely, that it varies with the force of the wind, weight of the rising body, power of propulsion, etc. This, in the language of physicists, is the angle of inclination, and, as a general thing, under normal conditions (still air) should be put down as about one in ten, or 5 3/4 degrees. This would be an ideal condition, but it has not, as vet been reached. The force of the wind affects the angle considerably, as does also the weight and velocity of the apparatus. In general practice the angle varies from 23 to 45 degrees. At more than 45 degrees the supporting effort is overcome by the resistance to forward motion. Increasing the speed or propulsive force, tends to lessen the angle at which the machine may be successfully operated because it reduces the wind pressure. Most of the modern flying machines are operated at an angle of 23 degrees, or less. Maintaining an Equilibrium. Stable equilibrium is one of the main essentials to successful flight, and this cannot be preserved in an uncertain, gusty wind, especially by an amateur. The novice should not attempt a glide unless the conditions are just right. These conditions are: A clear, level space, without obstructions, such as trees, etc., and a steady wind of not exceeding twelve miles an hour. Always fly against the wind. When a reasonable amount of proficiency in the handling of the machine on level ground has been acquired the field of practice may be changed to some gentle slope. In starting from a slope it will be found easier to keep the machine afloat, but the experience at first is likely to be very disconcerting to a man of less than iron nerve. As the glider sails away from the top of the slope the distance between him and the ground increases rapidly until the aviator thinks he is up a hundred miles in the air. If he will keep cool, manipulate his apparatus so as to preserve its equilibrium, and "let nature take its course," he will come down gradually and safely to the ground at a considerable distance from the starting place. This is one advantage of starting from an elevation--your machine will go further. But, if the aviator becomes "rattled"; if he loses control of his machine, serious results, including a bad fall with risk of death, are almost certain. And yet this practice is just as necessary as the initial lessons on level ground. When judgment is used, and "haste made slowly," there is very little real danger. While experimenting with gliders the Wrights made flights innumerable under all sorts of conditions and never had an accident of any kind. Effects of Wind Currents. The larger the machine the more difficult it will be to control its movements in the air, and yet enlargement is absolutely necessary as weight, in the form of motor, rudder, etc., is added. Air currents near the surface of the ground are diverted by every obstruction unless the wind is blowing hard enough to remove the obstruction entirely. Take, for instance, the case of a tree or shrub, in a moderate wind of from ten to twelve miles an hour. As the wind strikes the tree it divides, part going to one side and part going to the other, while still another part is directed upward and goes over the top of the obstruction. This makes the handling of a glider on an obstructed field difficult and uncertain. To handle a glider successfully the place of operation should be clear and the wind moderate and steady. If it is gusty postpone your flight. In this connection it will be well to understand the velocity of the wind, and what it means as shown in the following table: Miles per hour Feet per second Pressure per sq. foot 10 14.7 .492 25 36.7 3.075 50 73.3 12.300 100 146.6 49.200 Pressure of wind increases in proportion to the square of the velocity. Thus wind at 10 miles an hour has four times the pressure of wind at 5 miles an hour. The greater this pressure the large and heavier the object which can be raised. Any boy who has had experience in flying kites can testify to this, High winds, however, are almost invariably gusty and uncertain as to direction, and this makes them dangerous for aviators. It is also a self-evident fact that, beyond a certain stage, the harder the wind blows the more difficult it is to make headway against it. Launching Device for Gliders. On page 195 will be found a diagram of the various parts of a launcher for gliders, designed and patented by Mr. Octave Chanute. In describing this invention in Aeronautics, Mr. Chanute says: "In practicing, the track, preferably portable, is generally laid in the direction of the existing wind and the car, preferably a light platform-car, is placed on the track. The truck carrying the winding-drum and its motor is placed to windward a suitable distance--say from two hundred to one thousand feet--and is firmly blocked or anchored in line with the portable track, which is preferably 80 or 100 feet in length. The flying or gliding machine to be launched with its operator is placed on the platform-car at the leeward end of the portable track. The line, which is preferably a flexible combination wire-and-cord cable, is stretched between the winding-drum on the track and detachably secured to the flying or gliding machine, preferably by means of a trip-hoop, or else held in the hand of the operator, so that the operator may readily detach the same from the flying-machine when the desired height is attained." How Glider Is Started. "Then upon a signal given by the operator the engineer at the motor puts it into operation, gradually increasing the speed until the line is wound upon the drum at a maximum speed of, say, thirty miles an hour. The operator of the flying-machine, whether he stands upright and carries it on his shoulders, or whether he sits or lies down prone upon it, adjusts the aeroplane or carrying surfaces so that the wind shall strike them on the top and press downward instead of upward until the platform-car under action of the winding-drum and line attains the required speed. "When the operator judges that his speed is sufficient, and this depends upon the velocity of the wind as well as that of the car moving against the wind, he quickly causes the front of the flying-machine to tip upward, so that the relative wind striking on the under side of the planes or carrying surfaces shall lift the flying machine into the air. It then ascends like a kite to such height as may be desired by the operator, who then trips the hook and releases the line from the machine." What the Operator Does. "The operator being now free in the air has a certain initial velocity imparted by the winding-drum and line and also a potential energy corresponding to his height above the ground. If the flying or gliding machine is provided with a motor, he can utilize that in his further flight, and if it is a simple gliding machine without motor he can make a descending flight through the air to such distance as corresponds to the velocity acquired and the height gained, steering meanwhile by the devices provided for that purpose. "The simplest operation or maneuver is to continue the flight straight ahead against the wind; but it is possible to vary this course to the right or left, or even to return in downward flight with the wind to the vicinity of the starting-point. Upon nearing the ground the operator tips upward his carrying-surfaces and stops his headway upon the cushion of increased air resistance so caused. The operator is in no way permanently fastened to his machine, and the machine and the operator simply rest upon the light platform-car, so that the operator is free to rise with the machine from the car whenever the required initial velocity is attained. Motor For the Launcher. "The motor may be of any suitable kind or construction, but is preferably an electric or gasolene motor. The winding-drum is furnished with any suitable or customary reversing-guide to cause the line to wind smoothly and evenly upon the drum. The line is preferably a cable composed of flexible wire and having a cotton or other cord core to increase its flexibility. The line extends from the drum to the flying or gliding machine. Its free end may, if desired, be grasped and held by the operator until the flying-machine ascends to the desired height, when by simply letting go of the line the operator may continue his flight free. The line, however, is preferably connected to the flying or gliding machine directly by a trip-hook having a handle or trip lever within reach of the operator, so that when he ascends to the required height he may readily detach the line from the flying or gliding machine." CHAPTER VII. PUTTING ON THE RUDDER. Gliders as a rule have only one rudder, and this is in the rear. It tends to keep the apparatus with its head to the wind. Unlike the rudder on a boat it is fixed and immovable. The real motor-propelled flying machine, generally has both front and rear rudders manipulated by wire cables at the will of the operator. Allowing that the amateur has become reasonably expert in the manipulation of the glider he should, before constructing an actual flying machine, equip his glider with a rudder. Cross Pieces for Rudder Beam. To do this he should begin by putting in a cross piece, 2 feet long by 1/4 x 3/4 inches between the center struts, in the lower plane. This may be fastened to the struts with bolts or braces. The former method is preferable. On this cross piece, and on the rear frame of the plane itself, the rudder beam is clamped and bolted. This rudder beam is 8 feet 11 inches long. Having put these in place duplicate them in exactly the same manner and dimensions from the upper frame The cross pieces on which the ends of the rudder beams are clamped should be placed about one foot in advance of the rear frame beam. The Rudder Itself. The next step is to construct the rudder itself. This consists of two sections, one horizontal, the other vertical. The latter keeps the aeroplane headed into the wind, while the former keeps it steady--preserves the equilibrium. The rudder beams form the top and bottom frames of the vertical rudder. To these are bolted and clamped two upright pieces, 3 feet, 10 inches in length, and 3/4 inch in cross section. These latter pieces are placed about two feet apart. This completes the framework of the vertical rudder. See next page (59). For the horizontal rudder you will require two strips 6 feet long, and four 2 feet long. Find the exact center of the upright pieces on the vertical rudder, and at this spot fasten with bolts the long pieces of the horizontal, placing them on the outside of the vertical strips. Next join the ends of the horizontal strips with the 2-foot pieces, using small screws and corner braces. This done you will have two of the 2-foot pieces left. These go in the center of the horizontal frame, "straddling" the vertical strips, as shown in the illustration. The framework is to be covered with cloth in the same manner as the planes. For this about ten yards will be needed. Strengthening the Rudder. To ensure rigidity the rudder must be stayed with guy wires. For this purpose the No. 12 piano wire is the best. Begin by running two of these wires from the top eye-bolts of stanchions 3 and 4, page 37, to rudder beam where it joins the rudder planes, fastening them at the bottom. Then run two wires from the top of the rudder beam at the same point, to the bottom eye-bolts of the same stanchions. This will give you four diagonal wires reaching from the rudder beam to the top and bottom planes of the glider. Now, from the outer ends of the rudder frame run four similar diagonal wires to the end of the rudder beam where it rests on the cross piece. You will then have eight truss wires strengthening the connection of the rudder to the main body of the glider. The framework of the rudder planes is then to be braced in the same way, which will take eight more wires, four for each rudder plane. All the wires are to be connected at one end with turn-buckles so the tension may be regulated as desired. In forming the rudder frame it will be well to mortise the corners, tack them together with small nails, and then put in a corner brace in the inside of each joint. In doing this bear in mind that the material to be thus fastened is light, and consequently the lightest of nails, screws, bolts and corner pieces, etc., is necessary. CHAPTER VIII. THE REAL FLYING MACHINE. We will now assume that you have become proficient enough to warrant an attempt at the construction of a real flying machine--one that will not only remain suspended in the air at the will of the operator, but make respectable progress in whatever direction he may desire to go. The glider, it must be remembered, is not steerable, except to a limited extent, and moves only in one direction--against the wind. Besides this its power of flotation--suspension in the air--is circumscribed. Larger Surface Area Required. The real flying machine is the glider enlarged, and equipped with motor and propeller. The first thing to do is to decide upon the size required. While a glider of 20 foot spread is large enough to sustain a man it could not under any possible conditions, be made to rise with the weight of the motor, propeller and similar equipment added. As the load is increased so must the surface area of the planes be increased. Just what this increase in surface area should be is problematical as experienced aviators disagree, but as a general proposition it may be placed at from three to four times the area of a 20-foot glider. [3] Some Practical Examples. The Wrights used a biplane 41 feet in spread, and 6 1/2 ft. deep. This, for the two planes, gives a total surface area of 538 square feet, inclusive of auxiliary planes. This sustains the engine equipment, operator, etc., a total weight officially announced at 1,070 pounds. It shows a lifting capacity of about two pounds to the square foot of plane surface, as against a lifting capacity of about 1/2 pound per square foot of plane surface for the 20-foot glider. This same Wright machine is also reported to have made a successful flight, carrying a total load of 1,100 pounds, which would be over two pounds for each square foot of surface area, which, with auxiliary planes, is 538 square feet. To attain the same results in a monoplane, the single surface would have to be 60 feet in spread and 9 feet deep. But, while this is the mathematical rule, Bleriot has demonstrated that it does not always hold good. On his record-breaking trip across the English channel, July 25th, 1909, the Frenchman was carried in a monoplane 24 1/2 feet in spread, and with a total sustaining surface of 150 1/2 square feet. The total weight of the outfit, including machine, operator and fuel sufficient for a three-hour run, was only 660 pounds. With an engine of (nominally) 25 horsepower the distance of 21 miles was covered in 37 minutes. Which is the Best? Right here an established mathematical quantity is involved. A small plane surface offers less resistance to the air than a large one and consequently can attain a higher rate of speed. As explained further on in this chapter speed is an important factor in the matter of weight-sustaining capacity. A machine that travels one-third faster than another can get along with one-half the surface area of the latter without affecting the load. See the closing paragraph of this chapter on this point. In theory the construction is also the simplest, but this is not always found to be so in practice. The designing and carrying into execution of plans for an extensive area like that of a monoplane involves great skill and cleverness in getting a framework that will be strong enough to furnish the requisite support without an undue excess of weight. This proposition is greatly simplified in the biplane and, while the speed attained by the latter may not be quite so great as that of the monoplane, it has much larger weight-carrying capacity. Proper Sizes For Frame. Allowing that the biplane form is selected the construction may be practically identical with that of the 20-foot glider described in Chapter V., except as to size and elimination of the armpieces. In size the surface planes should be about twice as large as those of the 20-foot glider, viz: 40 feet spread instead of 20, and 6 feet deep instead of 3. The horizontal beams, struts, stanchions, ribs, etc., should also be increased in size proportionately. While care in the selection of clear, straight-grained timber is important in the glider, it is still more important in the construction of a motor-equipped flying machine as the strain on the various parts will be much greater. How to Splice Timbers. It is practically certain that you will have to resort to splicing the horizontal beams as it will be difficult, if not impossible, to find 40-foot pieces of timber totally free from knots and worm holes, and of straight grain. If splicing is necessary select two good 20-foot pieces, 3 inches wide and 1 1/2 inches thick, and one 10-foot long, of the same thickness and width. Plane off the bottom sides of the 10-foot strip, beginning about two feet back from each end, and taper them so the strip will be about 3/4 inch thick at the extreme ends. Lay the two 20-foot beams end to end, and under the joint thus made place the 10-foot strip, with the planed-off ends downward. The joint of the 20-foot pieces should be directly in the center of the 10-foot piece. Bore ten holes (with a 1/4-inch augur) equi-distant apart through the 20-foot strips and the 10-foot strip under them. Through these holes run 1/4-inch stove bolts with round, beveled heads. In placing these bolts use washers top and bottom, one between the head and the top beam, and the other between the bottom beam and the screw nut which holds the bolt. Screw the nuts down hard so as to bring the two beams tightly together, and you will have a rigid 40-foot beam. Splicing with Metal Sleeves. An even better way of making a splice is by tonguing and grooving the ends of the frame pieces and enclosing them in a metal sleeve, but it requires more mechanical skill than the method first named. The operation of tonguing and grooving is especially delicate and calls for extreme nicety of touch in the handling of tools, but if this dexterity is possessed the job will be much more satisfactory than one done with a third timber. As the frame pieces are generally about 1 1/2 inch in diameter, the tongue and the groove into which the tongue fits must be correspondingly small. Begin by sawing into one side of one of the frame pieces about 4 inches back from the end. Make the cut about 1/2 inch deep. Then turn the piece over and duplicate the cut. Next saw down from the end to these cuts. When the sawed-out parts are removed you will have a "tongue" in the end of the frame timber 4 inches long and 1/2 inch thick. The next move is to saw out a 5/8-inch groove in the end of the frame piece which is to be joined. You will have to use a small chisel to remove the 5/8-inch bit. This will leave a groove into which the tongue will fit easily. Joining the Two Pieces. Take a thin metal sleeve--this is merely a hollow tube of aluminum or brass open at each end--8 inches long, and slip it over either the tongued or grooved end of one of the frame timbers. It is well to have the sleeve fit snugly, and this may necessitate a sand-papering of the frame pieces so the sleeve will slip on. Push the sleeve well back out of the way. Cover the tongue thoroughly with glue, and also put some on the inside of the groove. Use plenty of glue. Now press the tongue into the groove, and keep the ends firmly together until the glue is thoroughly dried. Rub off the joint lightly with sand-paper to remove any of the glue which may have oozed out, and slip the sleeve into place over the joint. Tack the sleeve in position with small copper tacks, and you will have an ideal splice. The same operation is to be repeated on each of the four frame pieces. Two 20-foot pieces joined in this way will give a substantial frame, but when suitable timber of this kind can not be had, three pieces, each 6 feet 11 inches long, may be used. This would give 20 feet 9 inches, of which 8 inches will be taken up in the two joints, leaving the frame 20 feet 1 inch long. Installation of Motor. Next comes the installation of the motor. The kinds and efficiency of the various types are described in the following chapter (IX). All we are interested in at this point is the manner of installation. This varies according to the personal ideas of the aviator. Thus one man puts his motor in the front of his machine, another places it in the center, and still another finds the rear of the frame the best. All get good results, the comparative advantages of which it is difficult to estimate. Where one man, as already explained, flies faster than another, the one beaten from the speed standpoint has an advantage in the matter of carrying weight, etc. The ideas of various well-known aviators as to the correct placing of motors may be had from the following: Wrights--In rear of machine and to one side. Curtiss--Well to rear, about midway between upper and lower planes. Raich--In rear, above the center. Brauner-Smith--In exact center of machine. Van Anden--In center. Herring-Burgess--Directly behind operator. Voisin--In rear, and on lower plane. Bleriot--In front. R. E. P.--In front. The One Chief Object. An even distribution of the load so as to assist in maintaining the equilibrium of the machine, should be the one chief object in deciding upon the location of the motor. It matters little what particular spot is selected so long as the weight does not tend to overbalance the machine, or to "throw it off an even keel." It is just like loading a vessel, an operation in which the expert seeks to so distribute the weight of the cargo as to keep the vessel in a perfectly upright position, and prevent a "list" or leaning to one side. The more evenly the cargo is distributed the more perfect will be the equilibrium of the vessel and the better it can be handled. Sometimes, when not properly stowed, the cargo shifts, and this at once affects the position of the craft. When a ship "lists" to starboard or port a preponderating weight of the cargo has shifted sideways; if bow or stern is unduly depressed it is a sure indication that the cargo has shifted accordingly. In either event the handling of the craft becomes not only difficult, but extremely hazardous. Exactly the same conditions prevail in the handling of a flying machine. Shape of Machine a Factor. In placing the motor you must be governed largely by the shape and construction of the flying machine frame. If the bulk of the weight of the machine and auxiliaries is toward the rear, then the natural location for the motor will be well to the front so as to counterbalance the excess in rear weight. In the same way if the preponderance of the weight is forward, then the motor should be placed back of the center. As the propeller blade is really an integral part of the motor, the latter being useless without it, its placing naturally depends upon the location selected for the motor. Rudders and Auxiliary Planes. Here again there is great diversity of opinion among aviators as to size, location and form. The striking difference of ideas in this respect is well illustrated in the choice made by prominent makers as follows: Voisin--horizontal rudder, with two wing-like planes, in front; box-like longitudinal stability plane in rear, inside of which is a vertical rudder. Wright--large biplane horizontal rudder in front at considerable distance--about 10 feet--from the main planes; vertical biplane rudder in rear; ends of upper and lower main planes made flexible so they may be moved. Curtiss--horizontal biplane rudder, with vertical damping plane between the rudder planes about 10 feet in front of main planes; vertical rudder in rear; stabilizing planes at each end of upper main plane. Bleriot--V-shaped stabilizing fin, projecting from rear of plane, with broad end outward; to the broad end of this fin is hinged a vertical rudder; horizontal biplane rudder, also in rear, under the fin. These instances show forcefully the wide diversity of opinion existing among experienced aviators as to the best manner of placing the rudders and stabilizing, or auxiliary planes, and make manifest how hopeless would be the task of attempting to select any one form and advise its exclusive use. Rudder and Auxiliary Construction. The material used in the construction of the rudders and auxiliary planes is the same as that used in the main planes--spruce for the framework and some kind of rubberized or varnished cloth for the covering. The frames are joined and wired in exactly the same manner as the frames of the main planes, the purpose being to secure the same strength and rigidity. Dimensions of the various parts depend upon the plan adopted and the size of the main plane. No details as to exact dimensions of these rudders and auxiliary planes are obtainable. The various builders, while willing enough to supply data as to the general measurements, weight, power, etc., of their machines, appear to have overlooked the details of the auxiliary parts, thinking, perhaps, that these were of no particular import to the general public. In the Wright machine, the rear horizontal and front vertical rudders may be set down as being about one-quarter (probably a little less) the size of the main supporting planes. Arrangement of Alighting Gear. Most modern machines are equipped with an alighting gear, which not only serves to protect the machine and aviator from shock or injury in touching the ground, but also aids in getting under headway. All the leading makes, with the exception of the Wright, are furnished with a frame carrying from two to five pneumatic rubber-tired bicycle wheels. In the Curtiss and Voisin machines one wheel is placed in front and two in the rear. In the Bleriot and other prominent machines the reverse is the rule--two wheels in front and one in the rear. Farman makes use of five wheels, one in the extreme rear, and four, arranged in pairs, a little to the front of the center of the main lower plane. In place of wheels the Wright machine is equipped with a skid-like device consisting of two long beams attached to the lower plane by stanchions and curving up far in front, so as to act as supports to the horizontal rudder. Why Wood Is Favored. A frequently asked question is: "Why is not aluminum, or some similar metal, substituted for wood." Wood, particularly spruce, is preferred because, weight considered, it is much stronger than aluminum, and this is the lightest of all metals. In this connection the following table will be of interest: Compressive Weight Tensile Strength Strength per cubic foot per sq. inch per sq. inch Material in lbs. in lbs. in lbs. Spruce.... 25 8,000 5,000 Aluminum 162 16,000 ...... Brass (sheet) 510 23,000 12,000 Steel (tool) 490 100,000 40,000 Copper (sheet) 548 30,000 40,000 As extreme lightness, combined with strength, especially tensile strength, is the great essential in flying-machine construction, it can be readily seen that the use of metal, even aluminum, for the framework, is prohibited by its weight. While aluminum has double the strength of spruce wood it is vastly heavier, and thus the advantage it has in strength is overbalanced many times by its weight. The specific gravity of aluminum is 2.50; that of spruce is only 0.403. Things to Be Considered. In laying out plans for a flying machine there are five important points which should be settled upon before the actual work of construction is started. These are: First--Approximate weight of the machine when finished and equipped. Second--Area of the supporting surface required. Third--Amount of power that will be necessary to secure the desired speed and lifting capacity. Fourth--Exact dimensions of the main framework and of the auxiliary parts. Fifth--Size, speed and character of the propeller. In deciding upon these it will be well to take into consideration the experience of expert aviators regarding these features as given elsewhere. (See Chapter X.) Estimating the Weights Involved. In fixing upon the probable approximate weight in advance of construction much, of course, must be assumed. This means that it will be a matter of advance estimating. If a two-passenger machine is to be built we will start by assuming the maximum combined weight of the two people to be 350 pounds. Most of the professional aviators are lighter than this. Taking the medium between the weights of the Curtiss and Wright machines we have a net average of 850 pounds for the framework, motor, propeller, etc. This, with the two passengers, amounts to 1,190 pounds. As the machines quoted are in successful operation it will be reasonable to assume that this will be a safe basis to operate on. What the Novice Must Avoid. This does not mean, however, that it will be safe to follow these weights exactly in construction, but that they will serve merely as a basis to start from. Because an expert can turn out a machine, thoroughly equipped, of 850 pounds weight, it does not follow that a novice can do the same thing. The expert's work is the result of years of experience, and he has learned how to construct frames and motor plants of the utmost lightness and strength. It will be safer for the novice to assume that he can not duplicate the work of such men as Wright and Curtiss without adding materially to the gross weight of the framework and equipment minus passengers. How to Distribute the Weight. Let us take 1,030 pounds as the net weight of the machine as against the same average in the Wright and Curtiss machines. Now comes the question of distributing this weight between the framework, motor, and other equipment. As a general proposition the framework should weigh about twice as much as the complete power plant (this is for amateur work). The word "framework" indicates not only the wooden frames of the main planes, auxiliary planes, rudders, etc., but the cloth coverings as well--everything in fact except the engine and propeller. On the basis named the framework would weigh 686 pounds, and the power plant 344. These figures are liberal, and the results desired may be obtained well within them as the novice will learn as he makes progress in the work. Figuring on Surface Area. It was Prof. Langley who first brought into prominence in connection with flying machine construction the mathematical principle that the larger the object the smaller may be the relative area of support. As explained in Chapter XIII, there are mechanical limits as to size which it is not practical to exceed, but the main principle remains in effect. Take two aeroplanes of marked difference in area of surface. The larger will, as a rule, sustain a greater weight in relative proportion to its area than the smaller one, and do the work with less relative horsepower. As a general thing well-constructed machines will average a supporting capacity of one pound for every one-half square foot of surface area. Accepting this as a working rule we find that to sustain a weight of 1,200 pounds--machine and two passengers--we should have 600 square feet of surface. Distributing the Surface Area. The largest surfaces now in use are those of the Wright, Voisin and Antoinette machines--538 square feet in each. The actual sustaining power of these machines, so far as known, has never been tested to the limit; it is probable that the maximum is considerably in excess of what they have been called upon to show. In actual practice the average is a little over one pound for each one-half square foot of surface area. Allowing that 600 square feet of surface will be used, the next question is how to distribute it to the best advantage. This is another important matter in which individual preference must rule. We have seen how the professionals disagree on this point, some using auxiliary planes of large size, and others depending upon smaller auxiliaries with an increase in number so as to secure on a different plan virtually the same amount of surface. In deciding upon this feature the best thing to do is to follow the plans of some successful aviator, increasing the area of the auxiliaries in proportion to the increase in the area of the main planes. Thus, if you use 600 square feet of surface where the man whose plans you are following uses 500, it is simply a matter of making your planes one-fifth larger all around. The Cost of Production. Cost of production will be of interest to the amateur who essays to construct a flying machine. Assuming that the size decided upon is double that of the glider the material for the framework, timber, cloth, wire, etc., will cost a little more than double. This is because it must be heavier in proportion to the increased size of the framework, and heavy material brings a larger price than the lighter goods. If we allow $20 as the cost of the glider material it will be safe to put down the cost of that required for a real flying machine framework at $60, provided the owner builds it himself. As regards the cost of motor and similar equipment it can only be said that this depends upon the selection made. There are some reliable aviation motors which may be had as low as $500, and there are others which cost as much as $2,000. Services of Expert Necessary. No matter what kind of a motor may be selected the services of an expert will be necessary in its proper installation unless the amateur has considerable genius in this line himself. As a general thing $25 should be a liberal allowance for this work. No matter how carefully the engine may be placed and connected it will be largely a matter of luck if it is installed in exactly the proper manner at the first attempt. The chances are that several alterations, prompted by the results of trials, will have to be made. If this is the case the expert's bill may readily run up to $50. If the amateur is competent to do this part of the work the entire item of $50 may, of course, be cut out. As a general proposition a fairly satisfactory flying machine, one that will actually fly and carry the operator with it, may be constructed for $750, but it will lack the better qualities which mark the higher priced machines. This computation is made on the basis of $60 for material, $50 for services of expert, $600 for motor, etc., and an allowance of $40 for extras. No man who has the flying machine germ in his system will be long satisfied with his first moderate price machine, no matter how well it may work. It's the old story of the automobile "bug" over again. The man who starts in with a modest $1,000 automobile invariably progresses by easy stages to the $4,000 or $5,000 class. The natural tendency is to want the biggest and best attainable within the financial reach of the owner. It's exactly the same way with the flying machine convert. The more proficient he becomes in the manipulation of his car, the stronger becomes the desire to fly further and stay in the air longer than the rest of his brethren. This necessitates larger, more powerful, and more expensive machines as the work of the germ progresses. Speed Affects Weight Capacity. Don't overlook the fact that the greater speed you can attain the smaller will be the surface area you can get along with. If a machine with 500 square feet of sustaining surface, traveling at a speed of 40 miles an hour, will carry a weight of 1,200 pounds, we can cut the sustaining surface in half and get along with 250 square feet, provided a speed of 60 miles an hour can be obtained. At 100 miles an hour only 80 square feet of surface area would be required. In both instances the weight sustaining capacity will remain the same as with the 500 square feet of surface area--1,200 pounds. One of these days some mathematical genius will figure out this problem with exactitude and we will have a dependable table giving the maximum carrying capacity of various surface areas at various stated speeds, based on the dimensions of the advancing edges. At present it is largely a matter of guesswork so far as making accurate computation goes. Much depends upon the shape of the machine, and the amount of surface offering resistance to the wind, etc. CHAPTER IX. SELECTION OF THE MOTOR. Motors for flying machines must be light in weight, of great strength, productive of extreme speed, and positively dependable in action. It matters little as to the particular form, or whether air or water cooled, so long as the four features named are secured. There are at least a dozen such motors or engines now in use. All are of the gasolene type, and all possess in greater or lesser degree the desired qualities. Some of these motors are: Renault--8-cylinder, air-cooled; 50 horse power; weight 374 pounds. Fiat--8-cylinder, air-cooled; 50 horse power; weight 150 pounds. Farcot--8-cylinder, air-cooled; from 30 to 100 horse power, according to bore of cylinders; weight of smallest, 84 pounds. R. E. P.--10-cylinder, air-cooled; 150 horse power; weight 215 pounds. Gnome--7 and 14 cylinders, revolving type, air-cooled; 50 and 100 horse power; weight 150 and 300 pounds. Darracq--2 to 14 cylinders, water cooled; 30 to 200 horse power; weight of smallest 100 pounds. Wright--4-cylinder, water-cooled; 25 horse power; weight 200 pounds. Antoinette--8 and 16-cylinder, water-cooled; 50 and 100 horse power; weight 250 and 500 pounds. E. N. V.--8-cylinder, water-cooled; from 30 to 80 horse power, according to bore of cylinder; weight 150 to 400 pounds. Curtiss--8-cylinder, water-cooled; 60 horse power; weight 300 pounds. Average Weight Per Horse Power. It will be noticed that the Gnome motor is unusually light, being about three pounds to the horse power produced, as opposed to an average of 4 1/2 pounds per horse power in other makes. This result is secured by the elimination of the fly-wheel, the engine itself revolving, thus obtaining the same effect that would be produced by a fly-wheel. The Farcot is even lighter, being considerably less than three pounds per horse power, which is the nearest approach to the long-sought engine equipment that will make possible a complete flying machine the total weight of which will not exceed one pound per square foot of area. How Lightness Is Secured. Thus far foreign manufacturers are ahead of Americans in the production of light-weight aerial motors, as is evidenced by the Gnome and Farcot engines, both of which are of French make. Extreme lightness is made possible by the use of fine, specially prepared steel for the cylinders, thus permitting them to be much thinner than if ordinary forms of steel were used. Another big saving in weight is made by substituting what are known as "auto lubricating" alloys for bearings. These alloys are made of a combination of aluminum and magnesium. Still further gains are made in the use of alloy steel tubing instead of solid rods, and also by the paring away of material wherever it can be done without sacrificing strength. This plan, with the exclusive use of the best grades of steel, regardless of cost, makes possible a marked reduction in weight. Multiplicity of Cylinders. Strange as it may seem, multiplicity of cylinders does not always add proportionate weight. Because a 4-cylinder motor weighs say 100 pounds, it does not necessarily follow that an 8-cylinder equipment will weigh 200 pounds. The reason of this will be plain when it is understood that many of the parts essential to a 4-cylinder motor will fill the requirements of an 8-cylinder motor without enlargement or addition. Neither does multiplying the cylinders always increase the horsepower proportionately. If a 4-cylinder motor is rated at 25 horsepower it is not safe to take it for granted that double the number of cylinders will give 50 horsepower. Generally speaking, eight cylinders, the bore, stroke and speed being the same, will give double the power that can be obtained from four, but this does not always hold good. Just why this exception should occur is not explainable by any accepted rule. Horse Power and Speed. Speed is an important requisite in a flying-machine motor, as the velocity of the aeroplane is a vital factor in flotation. At first thought, the propeller and similar adjuncts being equal, the inexperienced mind would naturally argue that a 50-horsepower engine should produce just double the speed of one of 25-horsepower. That this is a fallacy is shown by actual performances. The Wrights, using a 25-horsepower motor, have made 44 miles an hour, while Bleriot, with a 50-horsepower motor, has a record of a short-distance flight at the rate of 52 miles an hour. The fact is that, so far as speed is concerned, much depends upon the velocity of the wind, the size and shape of the aeroplane itself, and the size, shape and gearing of the propeller. The stronger the wind is blowing the easier it will be for the aeroplane to ascend, but at the same time the more difficult it will be to make headway against the wind in a horizontal direction. With a strong head wind, and proper engine force, your machine will progress to a certain extent, but it will be at an angle. If the aviator desired to keep on going upward this would be all right, but there is a limit to the altitude which it is desirable to reach--from 100 to 500 feet for experts--and after that it becomes a question of going straight ahead. Great Waste of Power. One thing is certain--even in the most efficient of modern aerial motors there is a great loss of power between the two points of production and effect. The Wright outfit, which is admittedly one of the most effective in use, takes one horsepower of force for the raising and propulsion of each 50 pounds of weight. This, for a 25-horsepower engine, would give a maximum lifting capacity of 1250 pounds. It is doubtful if any of the higher rated motors have greater efficiency. As an 8-cylinder motor requires more fuel to operate than a 4-cylinder, it naturally follows that it is more expensive to run than the smaller motor, and a normal increase in capacity, taking actual performances as a criterion, is lacking. In other words, what is the sense of using an 8-cylinder motor when one of 4 cylinders is sufficient? What the Propeller Does. Much of the efficiency of the motor is due to the form and gearing of the propeller. Here again, as in other vital parts of flying-machine mechanism, we have a wide divergence of opinion as to the best form. A fish makes progress through the water by using its fins and tail; a bird makes its way through the air in a similar manner by the use of its wings and tail. In both instances the motive power comes from the body of the fish or bird. In place of fins or wings the flying machine is equipped with a propeller, the action of which is furnished by the engine. Fins and wings have been tried, but they don't work. While operating on the same general principle, aerial propellers are much larger than those used on boats. This is because the boat propeller has a denser, more substantial medium to work in (water), and consequently can get a better "hold," and produce more propulsive force than one of the same size revolving in the air. This necessitates the aerial propellers being much larger than those employed for marine purposes. Up to this point all aviators agree, but as to the best form most of them differ. Kinds of Propellers Used. One of the most simple is that used by Curtiss. It consists of two pear-shaped blades of laminated wood, each blade being 5 inches wide at its extreme point, tapering slightly to the shaft connection. These blades are joined at the engine shaft, in a direct line. The propeller has a pitch of 5 feet, and weighs, complete, less than 10 pounds. The length from end to end of the two blades is 6 1/2 feet. Wright uses two wooden propellers, in the rear of his biplane, revolving in opposite directions. Each propeller is two-bladed. Bleriot also uses a two-blade wooden propeller, but it is placed in front of his machine. The blades are each about 3 1/2 feet long and have an acute "twist." Santos-Dumont uses a two-blade wooden propeller, strikingly similar to the Bleriot. On the Antoinette monoplane, with which good records have been made, the propeller consists of two spoon-shaped pieces of metal, joined at the engine shaft in front, and with the concave surfaces facing the machine. The propeller on the Voisin biplane is also of metal, consisting of two aluminum blades connected by a forged steel arm. Maximum thrust, or stress--exercise of the greatest air-displacing force--is the object sought. This, according to experts, is best obtained with a large propeller diameter and reasonably low speed. The diameter is the distance from end to end of the blades, which on the largest propellers ranges from 6 to 8 feet. The larger the blade surface the greater will be the volume of air displaced, and, following this, the greater will be the impulse which forces the aeroplane ahead. In all centrifugal motion there is more or less tendency to disintegration in the form of "flying off" from the center, and the larger the revolving object is the stronger is this tendency. This is illustrated in the many instances in which big grindstones and fly-wheels have burst from being revolved too fast. To have a propeller break apart in the air would jeopardize the life of the aviator, and to guard against this it has been found best to make its revolving action comparatively slow. Besides this the slow motion (it is only comparatively slow) gives the atmosphere a chance to refill the area disturbed by one propeller blade, and thus have a new surface for the next blade to act upon. Placing of the Motor. As on other points, aviators differ widely in their ideas as to the proper position for the motor. Wright locates his on the lower plane, midway between the front and rear edges, but considerably to one side of the exact center. He then counter-balances the engine weight by placing his seat far enough away in the opposite direction to preserve the center of gravity. This leaves a space in the center between the motor and the operator in which a passenger may be carried without disturbing the equilibrium. Bleriot, on the contrary, has his motor directly in front and preserves the center of gravity by taking his seat well back, this, with the weight of the aeroplane, acting as a counter-balance. On the Curtiss machine the motor is in the rear, the forward seat of the operator, and weight of the horizontal rudder and damping plane in front equalizing the engine weight. No Perfect Motor as Yet. Engine makers in the United States, England, France and Germany are all seeking to produce an ideal motor for aviation purposes. Many of the productions are highly creditable, but it may be truthfully said that none of them quite fill the bill as regards a combination of the minimum of weight with the maximum of reliable maintained power. They are all, in some respects, improvements upon those previously in use, but the great end sought for has not been fully attained. One of the motors thus produced was made by the French firm of Darracq at the suggestion of Santos Dumont, and on lines laid down by him. Santos Dumont wanted a 2-cylinder horizontal motor capable of developing 30 horsepower, and not exceeding 4 1/2 pounds per horsepower in weight. There can be no question as to the ability and skill of the Darracq people, or of their desire to produce a motor that would bring new credit and prominence to the firm. Neither could anything radically wrong be detected in the plans. But the motor, in at least one important requirement, fell short of expectations. It could not be depended upon to deliver an energy of 30 horsepower continuously for any length of time. Its maximum power could be secured only in "spurts." This tends to show how hard it is to produce an ideal motor for aviation purposes. Santos Dumont, of undoubted skill and experience as an aviator, outlined definitely what he wanted; one of the greatest designers in the business drew the plans, and the famous house of Darracq bent its best energies to the production. But the desired end was not fully attained. Features of Darracq Motor. Horizontal motors were practically abandoned some time ago in favor of the vertical type, but Santos Dumont had a logical reason for reverting to them. He wanted to secure a lower center of gravity than would be possible with a vertical engine. Theoretically his idea was correct as the horizontal motor lies flat, and therefore offers less resistance to the wind, but it did not work out as desired. At the same time it must be admitted that this Darracq motor is a marvel of ingenuity and exquisite workmanship. The two cylinders, having a bore of 5 1-10 inches and a stroke of 4 7-10 inches, are machined out of a solid bar of steel until their weight is only 8 4-5 pounds complete. The head is separate, carrying the seatings for the inlet and exhaust valves, is screwed onto the cylinder, and then welded in position. A copper water-jacket is fitted, and it is in this condition that the weight of 8 4-5 pounds is obtained. On long trips, especially in regions where gasolene is hard to get, the weight of the fuel supply is an important feature in aviation. As a natural consequence flying machine operators favor the motor of greatest economy in gasolene consumption, provided it gives the necessary power. An American inventor, Ramsey by name, is working on a motor which is said to possess great possibilities in this line. Its distinctive features include a connecting rod much shorter than usual, and a crank shaft located the length of the crank from the central axis of the cylinder. This has the effect of increasing the piston stroke, and also of increasing the proportion of the crank circle during which effective pressure is applied to the crank. Making the connecting rod shorter and leaving the crank mechanism the same would introduce excessive cylinder friction. This Ramsey overcomes by the location of his crank shaft. The effect of the long piston stroke thus secured, is to increase the expansion of the gases, which in turn increases the power of the engine without increasing the amount of fuel used. Propeller Thrust Important. There is one great principle in flying machine propulsion which must not be overlooked. No matter how powerful the engine may be unless the propeller thrust more than overcomes the wind pressure there can be no progress forward. Should the force of this propeller thrust and that of the wind pressure be equal the result is obvious. The machine is at a stand-still so far as forward progress is concerned and is deprived of the essential advancing movement. Speed not only furnishes sustentation for the airship, but adds to the stability of the machine. An aeroplane which may be jerky and uncertain in its movements, so far as equilibrium is concerned, when moving at a slow gait, will readily maintain an even keel when the speed is increased. Designs for Propeller Blades. It is the object of all men who design propellers to obtain the maximum of thrust with the minimum expenditure of engine energy. With this purpose in view many peculiar forms of propeller blades have been evolved. In theory it would seem that the best effects could be secured with blades so shaped as to present a thin (or cutting) edge when they come out of the wind, and then at the climax of displacement afford a maximum of surface so as to displace as much air as possible. While this is the form most generally favored there are others in successful operation. There is also wide difference in opinion as to the equipment of the propeller shaft with two or more blades. Some aviators use two and some four. All have more or less success. As a mathematical proposition it would seem that four blades should give more propulsive force than two, but here again comes in one of the puzzles of aviation, as this result is not always obtained. Difference in Propeller Efficiency. That there is a great difference in propeller efficiency is made readily apparent by the comparison of effects produced in two leading makes of machines--the Wright and the Voisin. In the former a weight of from 1,100 to 1,200 pounds is sustained and advance progress made at the rate of 40 miles an hour and more, with half the engine speed of a 25 horse-power motor. This would be a sustaining capacity of 48 pounds per horsepower. But the actual capacity of the Wright machine, as already stated, is 50 pounds per horsepower. The Voisin machine, with aviator, weighs about 1,370 pounds, and is operated with a so-horsepower motor. Allowing it the same speed as the Wright we find that, with double the engine energy, the lifting capacity is only 27 1/2 pounds per horsepower. To what shall we charge this remarkable difference? The surface of the planes is exactly the same in both machines so there is no advantage in the matter of supporting area. Comparison of Two Designs. On the Wright machine two wooden propellers of two blades each (each blade having a decided "twist") are used. As one 25 horsepower motor drives both propellers the engine energy amounts to just one-half of this for each, or 12 1/2 horsepower. And this energy is utilized at one-half the normal engine speed. On the Voisin a radically different system is employed. Here we have one metal two-bladed propeller with a very slight "twist" to the blade surfaces. The full energy of a 50-horsepower motor is utilized. Experts Fail to Agree. Why should there be such a marked difference in the results obtained? Who knows? Some experts maintain that it is because there are two propellers on the Wright machine and only one on the Voisin, and consequently double the propulsive power is exerted. But this is not a fair deduction, unless both propellers are of the same size. Propulsive power depends upon the amount of air displaced, and the energy put into the thrust which displaces the air. Other experts argue that the difference in results may be traced to the difference in blade design, especially in the matter of "twist." The fact is that propeller results depend largely upon the nature of the aeroplanes on which they are used. A propeller, for instance, which gives excellent results on one type of aeroplane, will not work satisfactorily on another. There are some features, however, which may be safely adopted in propeller selection. These are: As extensive a diameter as possible; blade area 10 to 15 per cent of the area swept; pitch four-fifths of the diameter; rotation slow. The maximum of thrust effort will be thus obtained. CHAPTER X. PROPER DIMENSIONS OF MACHINES. In laying out plans for a flying machine the first thing to decide upon is the size of the plane surfaces. The proportions of these must be based upon the load to be carried. This includes the total weight of the machine and equipment, and also the operator. This will be a rather difficult problem to figure out exactly, but practical approximate figures may be reached. It is easy to get at the weight of the operator, motor and propeller, but the matter of determining, before they are constructed, what the planes, rudders, auxiliaries, etc., will weigh when completed is an intricate proposition. The best way is to take the dimensions of some successful machine and use them, making such alterations in a minor way as you may desire. Dimensions of Leading Machines. In the following tables will be found the details as to surface area, weight, power, etc., of the nine principal types of flying machines which are now prominently before the public: MONOPLANES. Surface area Spread in Depth in Make Passengers sq. feet linear feet linear feet Santos-Dumont.. 1 110 16.0 26.0 Bleriot..... 1 150.6 24.6 22.0 R. E. P..... 1 215 34.1 28.9 Bleriot..... 2 236 32.9 23.0 Antoinette.... 2 538 41.2 37.9 No. of Weight Without Propeller Make Cylinders Horse Power Operator Diameter Santos-Dumont.. 2 30 250 5.0 Bleriot..... 3 25 680 6.9 R. E. P..... 7 35 900 6.6 Bleriot..... 7 50 1,240 8.1 Antoinette... 8 50 1,040 7.2 BIPLANES. Surface Area Spread in Depth in Make Passengers sq. feet linear feet linear feet Curtiss... 2 258 29.0 28.7 Wright.... 2 538 41.0 30.7 Farman.... 2 430 32.9 39.6 Voisin.... 2 538 37.9 39.6 No. of Weight Without Propeller Make Cylinders Horse Power Operator Diameter Curtiss... 8 50 600 6.0 Wright.... 4 25 1,100 8.1 Farman.... 7 50 1,200 8.9 Voisin.... 8 50 1,200 6.6 In giving the depth dimensions the length over all--from the extreme edge of the front auxiliary plane to the extreme tip of the rear is stated. Thus while the dimensions of the main planes of the Wright machine are 41 feet spread by 6 1/2 feet in depth, the depth over all is 30.7. Figuring Out the Details. With this data as a guide it should be comparatively easy to decide upon the dimensions of the machine required. In arriving at the maximum lifting capacity the weight of the operator must be added. Assuming this to average 170 pounds the method of procedure would be as follows: Add the weight of the operator to the weight of the complete machine. The new Wright machine complete weighs 900 pounds. This, plus 170, the weight of the operator, gives a total of 1,070 pounds. There are 538 square feet of supporting surface, or practically one square foot of surface area to each two pounds of load. There are some machines, notably the Bleriot, in which the supporting power is much greater. In this latter instance we find a surface area of 150 1/2 square feet carrying a load of 680 plus 170, or an aggregate of 850 pounds. This is the equivalent of five pounds to the square foot. This ratio is phenomenally large, and should not be taken as a guide by amateurs. The Matter of Passengers. These deductions are based on each machine carrying one passenger, which is admittedly the limit at present of the monoplanes like those operated for record-making purposes by Santos-Dumont and Bleriot. The biplanes, however, have a two-passenger capacity, and this adds materially to the proportion of their weight-sustaining power as compared with the surface area. In the following statement all the machines are figured on the one-passenger basis. Curtiss and Wright have carried two passengers on numerous occasions, and an extra 170 pounds should therefore be added to the total weight carried, which would materially increase the capacity. Even with the two-passenger load the limit is by no means reached, but as experiments have gone no further it is impossible to make more accurate figures. Average Proportions of Load. It will be interesting, before proceeding to lay out the dimension details, to make a comparison of the proportion of load effect with the supporting surfaces of various well-known machines. Here are the figures: Santos-Dumont--A trifle under four pounds per square foot. Bleriot--Five pounds. R. E. P.--Five pounds. Antoinette--About two and one-quarter pounds. Curtiss--About two and one-half pounds. Wright--Two and one-quarter pounds. Farman--A trifle over three pounds. Voisin--A little under two and one-half pounds. Importance of Engine Power. While these figures are authentic, they are in a way misleading, as the important factor of engine power is not taken into consideration. Let us recall the fact that it is the engine power which keeps the machine in motion, and that it is only while in motion that the machine will remain suspended in the air. Hence, to attribute the support solely to the surface area is erroneous. True, that once under headway the planes contribute largely to the sustaining effect, and are absolutely essential in aerial navigation--the motor could not rise without them--still, when it comes to a question of weight-sustaining power, we must also figure on the engine capacity. In the Wright machine, in which there is a lifting capacity of approximately 2 1/4 pounds to the square foot of surface area, an engine of only 25 horsepower is used. In the Curtiss, which has a lifting capacity of 2 1/2 pounds per square foot, the engine is of 50 horsepower. This is another of the peculiarities of aerial construction and navigation. Here we have a gain of 1/4 pound in weight-lifting capacity with an expenditure of double the horsepower. It is this feature which enables Curtiss to get along with a smaller surface area of supporting planes at the expense of a big increase in engine power. Proper Weight of Machine. As a general proposition the most satisfactory machine for amateur purposes will be found to be one with a total weight-sustaining power of about 1,200 pounds. Deducting 170 pounds as the weight of the operator, this will leave 1,030 pounds for the complete motor-equipped machine, and it should be easy to construct one within this limit. This implies, of course, that due care will be taken to eliminate all superfluous weight by using the lightest material compatible with strength and safety. This plan will admit of 686 pounds weight in the frame work, coverings, etc., and 344 for the motor, propeller, etc., which will be ample. Just how to distribute the weight of the planes is a matter which must be left to the ingenuity of the builder. Comparison of Bird Power. There is an interesting study in the accompanying illustration. Note that the surface area of the albatross is much smaller than that of the vulture, although the wing spread is about the same. Despite this the albatross accomplishes fully as much in the way of flight and soaring as the vulture. Why? Because the albaboss is quicker and more powerful in action. It is the application of this same principle in flying machines which enables those of great speed and power to get along with less supporting surface than those of slower movement. Measurements of Curtiss Machine. Some idea of framework proportion may be had from the following description of the Curtiss machine. The main planes have a spread (width) of 29 feet, and are 4 1/2 feet deep. The front double surface horizontal rudder is 6x2 feet, with an area of 24 square feet. To the rear of the main planes is a single surface horizontal plane 6x2 feet, with an area of 12 square feet. In connection with this is a vertical rudder 2 1/2 feet square. Two movable ailerons, or balancing planes, are placed at the extreme ends of the upper planes. These are 6x2 feet, and have a combined area of 24 square feet. There is also a triangular shaped vertical steadying surface in connection with the front rudder. Thus we have a total of 195 square feet, but as the official figures are 258, and the size of the triangular-shaped steadying surface is unknown, we must take it for granted that this makes up the difference. In the matter of proportion the horizontal double-plane rudder is about one-tenth the size of the main plane, counting the surface area of only one plane, the vertical rudder one-fortieth, and the ailerons one-twentieth. CHAPTER XI. PLANE AND RUDDER CONTROL. Having constructed and equipped your machine, the next thing is to decide upon the method of controlling the various rudders and auxiliary planes by which the direction and equilibrium and ascending and descending of the machine are governed. The operator must be in position to shift instantaneously the position of rudders and planes, and also to control the action of the motor. This latter is supposed to work automatically and as a general thing does so with entire satisfaction, but there are times when the supply of gasolene must be regulated, and similar things done. Airship navigation calls for quick action, and for this reason the matter of control is an important one--it is more than important; it is vital. Several Methods of Control. Some aviators use a steering wheel somewhat after the style of that used in automobiles, and by this not only manipulate the rudder planes, but also the flow of gasolene. Others employ foot levers, and still others, like the Wrights, depend upon hand levers. Curtiss steers his aeroplane by means of a wheel, but secures the desired stabilizing effect with an ingenious jointed chair-back. This is so arranged that by leaning toward the high point of his wing planes the aeroplane is restored to an even keel. The steering post of the wheel is movable backward and forward, and by this motion elevation is obtained. The Wrights for some time used two hand levers, one to steer by and warp the flexible tips of the planes, the other to secure elevation. They have now consolidated all the functions in one lever. Bleriot also uses the single lever control. Farman employs a lever to actuate the rudders, but manipulates the balancing planes by foot levers. Santos-Dumont uses two hand levers with which to steer and elevate, but manipulates the planes by means of an attachment to the back of his outer coat. Connection With the Levers. No matter which particular method is employed, the connection between the levers and the object to be manipulated is almost invariably by wire. For instance, from the steering levers (or lever) two wires connect with opposite sides of the rudder. As a lever is moved so as to draw in the right-hand wire the rudder is drawn to the right and vice versa. The operation is exactly the same as in steering a boat. It is the same way in changing the position of the balancing planes. A movement of the hands or feet and the machine has changed its course, or, if the equilibrium is threatened, is back on an even keel. Simple as this seems it calls for a cool head, quick eye, and steady hand. The least hesitation or a false movement, and both aviator and craft are in danger. Which Method is Best? It would be a bold man who would attempt to pick out any one of these methods of control and say it was better than the others. As in other sections of aeroplane mechanism each method has its advocates who dwell learnedly upon its advantages, but the fact remains that all the various plans work well and give satisfaction. What the novice is interested in knowing is how the control is effected, and whether he has become proficient enough in his manipulation of it to be absolutely dependable in time of emergency. No amateur should attempt a flight alone, until he has thoroughly mastered the steering and plane control. If the services and advice of an experienced aviator are not to be had the novice should mount his machine on some suitable supports so it will be well clear of the ground, and, getting into the operator's seat, proceed to make himself well acquainted with the operation of the steering wheel and levers. Some Things to Be Learned. He will soon learn that certain movements of the steering gear produce certain effects on the rudders. If, for instance, his machine is equipped with a steering wheel, he will find that turning the wheel to the right turns the aeroplane in the same direction, because the tiller is brought around to the left. In the same way he will learn that a given movement of the lever throws the forward edge of the main plane upward, and that the machine, getting the impetus of the wind under the concave surfaces of the planes, will ascend. In the same way it will quickly become apparent to him that an opposite movement of the lever will produce an opposite effect--the forward edges of the planes will be lowered, the air will be "spilled" out to the rear, and the machine will descend. The time expended in these preliminary lessons will be well spent. It would be an act of folly to attempt to actually sail the craft without them. CHAPTER XII. HOW TO USE THE MACHINE. It is a mistaken idea that flying machines must be operated at extreme altitudes. True, under the impetus of handsome prizes, and the incentive to advance scientific knowledge, professional aviators have ascended to considerable heights, flights at from 500 to 1,500 feet being now common with such experts as Farman, Bleriot, Latham, Paulhan, Wright and Curtiss. The altitude record at this time is about 4,165 feet, held by Paulhan. One of the instructions given by experienced aviators to pupils, and for which they insist upon implicit obeyance, is: "If your machine gets more than 30 feet high, or comes closer to the ground than 6 feet, descend at once." Such men as Wright and Curtiss will not tolerate a violation of this rule. If their instructions are not strictly complied with they decline to give the offender further lessons. Why This Rule Prevails. There is good reason for this precaution. The higher the altitude the more rarefied (thinner) becomes the air, and the less sustaining power it has. Consequently the more difficult it becomes to keep in suspension a given weight. When sailing within 30 feet of the ground sustentation is comparatively easy and, should a fall occur, the results are not likely to be serious. On the other hand, sailing too near the ground is almost as objectionable in many ways as getting up too high. If the craft is navigated too close to the ground trees, shrubs, fences and other obstructions are liable to be encountered. There is also the handicap of contrary air currents diverted by the obstructions referred to, and which will be explained more fully further on. How to Make a Start. Taking it for granted that the beginner has familiarized himself with the manipulation of the machine, and especially the control mechanism, the next thing in order is an actual flight. It is probable that his machine will be equipped with a wheeled alighting gear, as the skids used by the Wrights necessitate the use of a special starting track. In this respect the wheeled machine is much easier to handle so far as novices are concerned as it may be easily rolled to the trial grounds. This, as in the case of the initial experiments, should be a clear, reasonably level place, free from trees, fences, rocks and similar obstructions with which there may be danger of colliding. The beginner will need the assistance of three men. One of these should take his position in the rear of the machine, and one at each end. On reaching the trial ground the aviator takes his seat in the machine and, while the men at the ends hold it steady the one in the rear assists in retaining it until the operator is ready. In the meantime the aviator has started his motor. Like the glider the flying machine, in order to accomplish the desired results, should be headed into the wind. When the Machine Rises. Under the impulse of the pushing movement, and assisted by the motor action, the machine will gradually rise from the ground--provided it has been properly proportioned and put together, and everything is in working order. This is the time when the aviator requires a cool head, At a modest distance from the ground use the control lever to bring the machine on a horizontal level and overcome the tendency to rise. The exact manipulation of this lever depends upon the method of control adopted, and with this the aviator is supposed to have thoroughly familiarized himself as previously advised in Chapter XI. It is at this juncture that the operator must act promptly, but with the perfect composure begotten of confidence. One of the great drawbacks in aviation by novices is the tendency to become rattled, and this is much more prevalent than one might suppose, even among men who, under other conditions, are cool and confident in their actions. There is something in the sensation of being suddenly lifted from the ground, and suspended in the air that is disconcerting at the start, but this will soon wear off if the experimenter will keep cool. A few successful flights no matter how short they may be, will put a lot of confidence into him. Make Your Flights Short. Be modest in your initial flights. Don't attempt to match the records of experienced men who have devoted years to mastering the details of aviation. Paulhan, Farman, Bleriot, Wright, Curtiss, and all the rest of them began, and practiced for years, in the manner here described, being content to make just a little advancement at each attempt. A flight of 150 feet, cleanly and safely made, is better as a beginning than one of 400 yards full of bungling mishaps. And yet these latter have their uses, provided the operator is of a discerning mind and can take advantage of them as object lessons. But, it is not well to invite them. They will occur frequently enough under the most favorable conditions, and it is best to have them come later when the feeling of trepidation and uncertainty as to what to do has worn off. Above all, don't attempt to fly too high. Keep within a reasonable distance from the ground--about 25 or 30 feet. This advice is not given solely to lessen the risk of serious accident in case of collapse, but mainly because it will assist to instill confidence in the operator. It is comparatively easy to learn to swim in shallow water, but the knowledge that one is tempting death in deep water begets timidity. Preserving the Equilibrium. After learning how to start and stop, to ascend and descend, the next thing to master is the art of preserving equilibrium, the knack of keeping the machine perfectly level in the air--on an "even keel," as a sailor would say. This simile is particularly appropriate as all aviators are in reality sailors, and much more daring ones than those who course the seas. The latter are in craft which are kept afloat by the buoyancy of the water, whether in motion or otherwise and, so long as normal conditions prevail, will not sink. Aviators sail the air in craft in which constant motion must be maintained in order to ensure flotation. The man who has ridden a bicycle or motorcycle around curves at anything like high speed, will have a very good idea as to the principle of maintaining equilibrium in an airship. He knows that in rounding curves rapidly there is a marked tendency to change the direction of the motion which will result in an upset unless he overcomes it by an inclination of his body in an opposite direction. This is why we see racers lean well over when taking the curves. It simply must be done to preserve the equilibrium and avoid a spill. How It Works In the Air. If the equilibrium of an airship is disturbed to an extent which completely overcomes the center of gravity it falls according to the location of the displacement. If this displacement, for instance, is at either end the apparatus falls endways; if it is to the front or rear, the fall is in the corresponding direction. Owing to uncertain air currents--the air is continually shifting and eddying, especially within a hundred feet or so of the earth--the equilibrium of an airship is almost constantly being disturbed to some extent. Even if this disturbance is not serious enough to bring on a fall it interferes with the progress of the machine, and should be overcome at once. This is one of the things connected with aerial navigation which calls for prompt, intelligent action. Frequently, when the displacement is very slight, it may be overcome, and the craft immediately righted by a mere shifting of the operator's body. Take, for illustration, a case in which the extreme right end of the machine becomes lowered a trifle from the normal level. It is possible to bring it back into proper position by leaning over to the left far enough to shift the weight to the counter-balancing point. The same holds good as to minor front or rear displacements. When Planes Must Be Used. There are other displacements, however, and these are the most frequent, which can be only overcome by manipulation of the stabilizing planes. The method of procedure depends upon the form of machine in use. The Wright machine, as previously explained, is equipped with plane ends which are so contrived as to admit of their being warped (position changed) by means of the lever control. These flexible tip planes move simultaneously, but in opposite directions. As those on one end rise, those on the other end fall below the level of the main plane. By this means air is displaced at one point, and an increased amount secured in another. This may seem like a complicated system, but its workings are simple when once understood. It is by the manipulation or warping of these flexible tips that transverse stability is maintained, and any tendency to displacement endways is overcome. Longitudinal stability is governed by means of the front rudder. Stabilizing planes of some form are a feature, and a necessary feature, on all flying machines, but the methods of application and manipulation vary according to the individual ideas of the inventors. They all tend, however, toward the same end--the keeping of the machine perfectly level when being navigated in the air. When to Make a Flight. A beginner should never attempt to make a flight when a strong wind is blowing. The fiercer the wind, the more likely it is to be gusty and uncertain, and the more difficult it will be to control the machine. Even the most experienced and daring of aviators find there is a limit to wind speed against which they dare not compete. This is not because they lack courage, but have the sense to realize that it would be silly and useless. The novice will find a comparatively still day, or one when the wind is blowing at not to exceed 15 miles an hour, the best for his experiments. The machine will be more easily controlled, the trip will be safer, and also cheaper as the consumption of fuel increases with the speed of the wind against which the aeroplane is forced. CHAPTER XIII. PECULIARITIES OF AIRSHIP POWER. As a general proposition it takes much more power to propel an airship a given number of miles in a certain time than it does an automobile carrying a far heavier load. Automobiles with a gross load of 4,000 pounds, and equipped with engines of 30 horsepower, have travelled considerable distances at the rate of 50 miles an hour. This is an equivalent of about 134 pounds per horsepower. For an average modern flying machine, with a total load, machine and passengers, of 1,200 pounds, and equipped with a 50-horsepower engine, 50 miles an hour is the maximum. Here we have the equivalent of exactly 24 pounds per horsepower. Why this great difference? No less an authority than Mr. Octave Chanute answers the question in a plain, easily understood manner. He says: "In the case of an automobile the ground furnishes a stable support; in the case of a flying machine the engine must furnish the support and also velocity by which the apparatus is sustained in the air." Pressure of the Wind. Air pressure is a big factor in the matter of aeroplane horsepower. Allowing that a dead calm exists, a body moving in the atmosphere creates more or less resistance. The faster it moves, the greater is this resistance. Moving at the rate of 60 miles an hour the resistance, or wind pressure, is approximately 50 pounds to the square foot of surface presented. If the moving object is advancing at a right angle to the wind the following table will give the horsepower effect of the resistance per square foot of surface at various speeds. Horse Power Miles per Hour per sq. foot 10 0.013 15 0 044 20 0.105 25 0.205 30 0.354 40 0.84 50 1.64 60 2.83 80 6.72 100 13.12 While the pressure per square foot at 60 miles an hour, is only 1.64 horsepower, at 100 miles, less than double the speed, it has increased to 13.12 horsepower, or exactly eight times as much. In other words the pressure of the wind increases with the square of the velocity. Wind at 10 miles an hour has four times more pressure than wind at 5 miles an hour. How to Determine Upon Power. This element of air resistance must be taken into consideration in determining the engine horsepower required. When the machine is under headway sufficient to raise it from the ground (about 20 miles an hour), each square foot of surface resistance, will require nearly nine-tenths of a horsepower to overcome the wind pressure, and propel the machine through the air. As shown in the table the ratio of power required increases rapidly as the speed increases until at 60 miles an hour approximately 3 horsepower is needed. In a machine like the Curtiss the area of wind-exposed surface is about 15 square feet. On the basis of this resistance moving the machine at 40 miles an hour would require 12 horsepower. This computation covers only the machine's power to overcome resistance. It does not cover the power exerted in propelling the machine forward after the air pressure is overcome. To meet this important requirement Mr. Curtiss finds it necessary to use a 50-horsepower engine. Of this power, as has been already stated, 12 horsepower is consumed in meeting the wind pressure, leaving 38 horsepower for the purpose of making progress. The flying machine must move faster than the air to which it is opposed. Unless it does this there can be no direct progress. If the two forces are equal there is no straight-ahead advancement. Take, for sake of illustration, a case in which an aeroplane, which has developed a speed of 30 miles an hour, meets a wind velocity of equal force moving in an opposite direction. What is the result? There can be no advance because it is a contest between two evenly matched forces. The aeroplane stands still. The only way to get out of the difficulty is for the operator to wait for more favorable conditions, or bring his machine to the ground in the usual manner by manipulation of the control system. Take another case. An aeroplane, capable of making 50 miles an hour in a calm, is met by a head wind of 25 miles an hour. How much progress does the aeroplane make? Obviously it is 25 miles an hour over the ground. Put the proposition in still another way. If the wind is blowing harder than it is possible for the engine power to overcome, the machine will be forced backward. Wind Pressure a Necessity. While all this is true, the fact remains that wind pressure, up to a certain stage, is an absolute necessity in aerial navigation. The atmosphere itself has very little real supporting power, especially if inactive. If a body heavier than air is to remain afloat it must move rapidly while in suspension. One of the best illustrations of this is to be found in skating over thin ice. Every school boy knows that if he moves with speed he may skate or glide in safety across a thin sheet of ice that would not begin to bear his weight if he were standing still. Exactly the same proposition obtains in the case of the flying machine. The non-technical reason why the support of the machine becomes easier as the speed increases is that the sustaining power of the atmosphere increases with the resistance, and the speed with which the object is moving increases this resistance. With a velocity of 12 miles an hour the weight of the machine is practically reduced by 230 pounds. Thus, if under a condition of absolute calm it were possible to sustain a weight of 770 pounds, the same atmosphere would sustain a weight of 1,000 pounds moving at a speed of 12 miles an hour. This sustaining power increases rapidly as the speed increases. While at 12 miles the sustaining power is figured at 230 pounds, at 24 miles it is four times as great, or 920 pounds. Supporting Area of Birds. One of the things which all producing aviators seek to copy is the motive power of birds, particularly in their relation to the area of support. Close investigation has established the fact that the larger the bird the less is the relative area of support required to secure a given result. This is shown in the following table: Supporting Weight Surface Horse area Bird in lbs. in sq. feet power per lb. Pigeon 1.00 0.7 0.012 0.7 Wild Goose 9.00 2.65 0.026 0.2833 Buzzard 5.00 5.03 0.015 1.06 Condor 17.00 9.85 0.043 0.57 So far as known the condor is the largest of modern birds. It has a wing stretch of 10 feet from tip to tip, a supporting area of about 10 square feet, and weighs 17 pounds. It. is capable of exerting perhaps 1-30 horsepower. (These figures are, of course, approximate.) Comparing the condor with the buzzard with a wing stretch of 6 feet, supporting area of 5 square feet, and a little over 1-100 horsepower, it may be seen that, broadly speaking, the larger the bird the less surface area (relatively) is needed for its support in the air. Comparison With Aeroplanes. If we compare the bird figures with those made possible by the development of the aeroplane it will be readily seen that man has made a wonderful advance in imitating the results produced by nature. Here are the figures: Supporting Weight Surface Horse area Machine in lbs. in sq. feet power per lb. Santos-Dumont.. 350 110.00 30 0.314 Bleriot..... 700 150.00 25 0.214 Antoinette.... 1,200 538.00 50 0.448 Curtiss..... 700 258.00 60 0.368 Wright.....[4] 1,100 538.00 25 0.489 Farman...... 1,200 430.00 50 0.358 Voisin...... 1,200 538.00 50 0.448 While the average supporting surface is in favor of the aeroplane, this is more than overbalanced by the greater amount of horsepower required for the weight lifted. The average supporting surface in birds is about three-quarters of a square foot per pound. In the average aeroplane it is about one-half square foot per pound. On the other hand the average aeroplane has a lifting capacity of 24 pounds per horsepower, while the buzzard, for instance, lifts 5 pounds with 15-100 of a horsepower. If the Wright machine--which has a lifting power of 50 pounds per horsepower--should be alone considered the showing would be much more favorable to the aeroplane, but it would not be a fair comparison. More Surface, Less Power. Broadly speaking, the larger the supporting area the less will be the power required. Wright, by the use of 538 square feet of supporting surface, gets along with an engine of 25 horsepower. Curtiss, who uses only 258 square feet of surface, finds an engine of 50 horsepower is needed. Other things, such as frame, etc., being equal, it stands to reason that a reduction in the area of supporting surface will correspondingly reduce the weight of the machine. Thus we have the Curtiss machine with its 258 square feet of surface, weighing only 600 pounds (without operator), but requiring double the horsepower of the Wright machine with 538 square feet of surface and weighing 1,100 pounds. This demonstrates in a forceful way the proposition that the larger the surface the less power will be needed. But there is a limit, on account of its bulk and awkwardness in handling, beyond which the surface area cannot be enlarged. Otherwise it might be possible to equip and operate aeroplanes satisfactorily with engines of 15 horsepower, or even less. The Fuel Consumption Problem. Fuel consumption is a prime factor in the production of engine power. The veriest mechanical tyro knows in a general way that the more power is secured the more fuel must be consumed, allowing that there is no difference in the power-producing qualities of the material used. But few of us understand just what the ratio of increase is, or how it is caused. This proposition is one of keen interest in connection with aviation. Let us cite a problem which will illustrate the point quoted: Allowing that it takes a given amount of gasolene to propel a flying machine a given distance, half the way with the wind, and half against it, the wind blowing at one-half the speed of the machine, what will be the increase in fuel consumption? Increase of Thirty Per Cent. On the face of it there would seem to be no call for an increase as the resistance met when going against the wind is apparently offset by the propulsive force of the wind when the machine is travelling with it. This, however, is called faulty reasoning. The increase in fuel consumption, as figured by Mr. F. W. Lanchester, of the Royal Society of Arts, will be fully 30 per cent over the amount required for a similar operation of the machine in still air. If the journey should be made at right angles to the wind under the same conditions the increase would be 15 per cent. In other words Mr. Lanchester maintains that the work done by the motor in making headway against the wind for a certain distance calls for more engine energy, and consequently more fuel by 30 per cent, than is saved by the helping force of the wind on the return journey. CHAPTER XIV. ABOUT WIND CURRENTS, ETC. One of the first difficulties which the novice will encounter is the uncertainty of the wind currents. With a low velocity the wind, some distance away from the ground, is ordinarily steady. As the velocity increases, however, the wind generally becomes gusty and fitful in its action. This, it should be remembered, does not refer to the velocity of the machine, but to that of the air itself. In this connection Mr. Arthur T. Atherholt, president of the Aero Club of Pennsylvania, in addressing the Boston Society of Scientific Research, said: "Probably the whirlpools of Niagara contain no more erratic currents than the strata of air which is now immediately above us, a fact hard to realize on account of its invisibility." Changes In Wind Currents. While Mr. Atherholt's experience has been mainly with balloons it is all the more valuable on this account, as the balloons were at the mercy of the wind and their varying directions afforded an indisputable guide as to the changing course of the air currents. In speaking of this he said: "In the many trips taken, varying in distance traversed from twenty-five to 900 miles, it was never possible except in one instance to maintain a straight course. These uncertain currents were most noticeable in the Gordon-Bennett race from St. Louis in 1907. Of the nine aerostats competing in that event, eight covered a more or less direct course due east and southeast, whereas the writer, with Major Henry B. Hersey, first started northwest, then north, northeast, east, east by south, and when over the center of Lake Erie were again blown northwest notwithstanding that more favorable winds were sought for at altitudes varying from 100 to 3,000 meters, necessitating a finish in Canada nearly northeast of the starting point. "These nine balloons, making landings extending from Lake Ontario, Canada, to Virginia, all started from one point within the same hour. "The single exception to these roving currents occurred on October 21st, of last year (1909) when, starting from Philadelphia, the wind shifted more than eight degrees, the greatest variation being at the lowest altitudes, yet at no time was a height of over a mile reached. "Throughout the entire day the sky was overcast, with a thermometer varying from fifty-seven degrees at 300 feet to forty-four degrees, Fahrenheit at 5,000 feet, at which altitude the wind had a velocity of 43 miles an hour, in clouds of a cirro-cumulus nature, a landing finally being made near Tannersville, New York, in the Catskill mountains, after a voyage of five and one-half hours. "I have no knowledge of a recorded trip of this distance and duration, maintained in practically a straight line from start to finish." This wind disturbance is more noticeable and more difficult to contend with in a balloon than in a flying machine, owing to the bulk and unwieldy character of the former. At the same time it is not conducive to pleasant, safe or satisfactory sky-sailing in an aeroplane. This is not stated with the purpose of discouraging aviation, but merely that the operator may know what to expect and be prepared to meet it. Not only does the wind change its horizontal course abruptly and without notice, but it also shifts in a vertical direction, one second blowing up, and another down. No man has as yet fathomed the why and wherefore of this erratic action; it is only known that it exists. The most stable currents will be found from 50 to 100 feet from the earth, provided the wind is not diverted by such objects as trees, rocks, etc. That there are equally stable currents higher up is true, but they are generally to be found at excessive altitudes. How a Bird Meets Currents. Observe a bird in action on a windy day and you will find it continually changing the position of its wings. This is done to meet the varying gusts and eddies of the air so that sustentation may be maintained and headway made. One second the bird is bending its wings, altering the angle of incidence; the next it is lifting or depressing one wing at a time. Still again it will extend one wing tip in advance of the other, or be spreading or folding, lowering or raising its tail. All these motions have a meaning, a purpose. They assist the bird in preserving its equilibrium. Without them the bird would be just as helpless in the air as a human being and could not remain afloat. When the wind is still, or comparatively so, a bird, having secured the desired altitude by flight at an angle, may sail or soar with no wing action beyond an occasional stroke when it desires to advance. But, in a gusty, uncertain wind it must use its wings or alight somewhere. Trying to Imitate the Bird. Writing in _Fly_, Mr. William E. White says: "The bird's flight suggests a number of ways in which the equilibrium of a mechanical bird may be controlled. Each of these methods of control may be effected by several different forms of mechanism. "Placing the two wings of an aeroplane at an angle of three to five degrees to each other is perhaps the oldest way of securing lateral balance. This way readily occurs to anyone who watches a sea gull soaring. The theory of the dihedral angle is that when one wing is lifted by a gust of wind, the air is spilled from under it; while the other wing, being correspondingly depressed, presents a greater resistance to the gust and is lifted restoring the balance. A fixed angle of three to five degrees, however, will only be sufficient for very light puffs of wind and to mount the wings so that the whole wing may be moved to change the dihedral angle presents mechanical difficulties which would be better avoided. "The objection of mechanical impracticability applies to any plan to preserve the balance by shifting weight or ballast. The center of gravity should be lower than the center of the supporting surfaces, but cannot be made much lower. It is a common mistake to assume that complete stability will be secured by hanging the center of gravity very low on the principle of the parachute. An aeroplane depends upon rapid horizontal motion for its support, and if the center of gravity be far below the center of support, every change of speed or wind pressure will cause the machine to turn about its center of gravity, pitching forward and backward dangerously. Preserving Longitudinal Balance. "The birds maintain longitudinal, or fore and aft balance, by elevating or depressing their tails. Whether this action is secured in an aeroplane by means of a horizontal rudder placed in the rear, or by deflecting planes placed in front of the main planes, the principle is evidently the same. A horizontal rudder placed well to the rear as in the Antoinette, Bleriot or Santos-Dumont monoplanes, will be very much safer and steadier than the deflecting planes in front, as in the Wright or Curtiss biplanes, but not so sensitive or prompt in action. "The natural fore and aft stability is very much strengthened by placing the load well forward. The center of gravity near the front and a tail or rudder streaming to the rear secures stability as an arrow is balanced by the head and feathering. The adoption of this principle makes it almost impossible for the aeroplane to turn over. The Matter of Lateral Balance. "All successful aeroplanes thus far have maintained lateral balance by the principle of changing the angle of incidence of the wings. "Other ways of maintaining the lateral balance, suggested by observation of the flight of birds are--extending the wing tips and spilling the air through the pinions; or, what is the same thing, varying the area of the wings at their extremities. "Extending the wing tips seems to be a simple and effective solution of the problem. The tips may be made to swing outward upon a vertical axis placed at the front edge of the main planes; or they may be hinged to the ends of the main plane so as to be elevated or depressed through suitable connections by the aviator; or they may be supported from a horizontal axis parallel with the ends of the main planes so that they may swing outward, the aviator controlling both tips through one lever so that as one tip is extended the other is retracted. "The elastic wing pinions of a bird bend easily before the wind, permitting the gusts to glance off, but presenting always an even and efficient curvature to the steady currents of the air." High Winds Threaten Stability. To ensure perfect stability, without control, either human or automatic, it is asserted that the aeroplane must move faster than the wind is blowing. So long as the wind is blowing at the rate of 30 miles an hour, and the machine is traveling 40 or more, there will be little trouble as regards equilibrium so far as wind disturbance goes, provided the wind blows evenly and does not come in gusts or eddying currents. But when conditions are reversed--when the machine travels only 30 miles an hour and the wind blows at the rate of 50, look out for loss of equilibrium. One of the main reasons for this is that high winds are rarely steady; they seldom blow for any length of time at the same speed. They are usually "gusty," the gusts being a momentary movement at a higher speed. Tornadic gusts are also formed by the meeting of two opposing currents, causing a whirling motion, which makes stability uncertain. Besides, it is not unusual for wind of high speed to suddenly change its direction without warning. Trouble With Vertical Columns. Vertical currents--columns of ascending air--are frequently encountered in unexpected places and have more or less tendency, according to their strength, to make it difficult to keep the machine within a reasonable distance from the ground. These vertical currents are most generally noticeable in the vicinity of steep cliffs, or deep ravines. In such instances they are usually of considerable strength, being caused by the deflection of strong winds blowing against the face of the cliffs. This deflection exerts a back pressure which is felt quite a distance away from the point of origin, so that the vertical current exerts an influence in forcing the machine upward long before the cliff is reached. CHAPTER XV. THE ELEMENT OF DANGER. That there is an element of danger in aviation is undeniable, but it is nowhere so great as the public imagines. Men are killed and injured in the operation of flying machines just as they are killed and injured in the operation of railways. Considering the character of aviation the percentage of casualties is surprisingly small. This is because the results following a collapse in the air are very much different from what might be imagined. Instead of dropping to the ground like a bullet an aeroplane, under ordinary conditions will, when anything goes wrong, sail gently downward like a parachute, particularly if the operator is cool-headed and nervy enough to so manipulate the apparatus as to preserve its equilibrium and keep the machine on an even keel. Two Fields of Safety. At least one prominent aviator has declared that there are two fields of safety--one close to the ground, and the other well up in the air. In the first-named the fall will be a slight one with little chance of the operator being seriously hurt. From the field of high altitude the the descent will be gradual, as a rule, the planes of the machine serving to break the force of the fall. With a cool-headed operator in control the aeroplane may be even guided at an angle (about 1 to 8) in its descent so as to touch the ground with a gliding motion and with a minimum of impact. Such an experience, of course, is far from pleasant, but it is by no means so dangerous as might appear. There is more real danger in falling from an elevation of 75 or 100 feet than there is from 1,000 feet, as in the former case there is no chance for the machine to serve as a parachute--its contact with the ground comes too quickly. Lesson in Recent Accidents. Among the more recent fatalities in aviation are the deaths of Antonio Fernandez and Leon Delagrange. The former was thrown to the ground by a sudden stoppage of his motor, the entire machine seeming to collapse. It is evident there were radical defects, not only in the motor, but in the aeroplane framework as well. At the time of the stoppage it is estimated that Fernandez was up about 1,500 feet, but the machine got no opportunity to exert a parachute effect, as it broke up immediately. This would indicate a fatal weakness in the structure which, under proper testing, could probably have been detected before it was used in flight. It is hard to say it, but Delagrange appears to have been culpable to great degree in overloading his machine with a motor equipment much heavier than it was designed to sustain. He was 65 feet up in the air when the collapse occurred, resulting in his death. As in the case of Fernandez common-sense precaution would doubtless have prevented the fatality. Aviation Not Extra Hazardous. All told there have been, up to the time of this writing (April, 1910), just five fatalities in the history of power-driven aviation. This is surprisingly low when the nature of the experiments, and the fact that most of the operators were far from having extended experience, is taken into consideration. Men like the Wrights, Curtiss, Bleriot, Farman, Paulhan and others, are now experts, but there was a time, and it was not long ago, when they were unskilled. That they, with numerous others less widely known, should have come safely through their many experiments would seem to disprove the prevailing idea that aviation is an extra hazardous pursuit. In the hands of careful, quick-witted, nervy men the sailing of an airship should be no more hazardous than the sailing of a yacht. A vessel captain with common sense will not go to sea in a storm, or navigate a weak, unseaworthy craft. Neither should an aviator attempt to sail when the wind is high and gusty, nor with a machine which has not been thoroughly tested and found to be strong and safe. Safer Than Railroading. Statistics show that some 12,000 people are killed and 72,000 injured every year on the railroads of the United States. Come to think it over it is small wonder that the list of fatalities is so large. Trains are run at high speeds, dashing over crossings at which collisions are liable to occur, and over bridges which often collapse or are swept away by floods. Still, while the number of casualties is large, the actual percentage is small considering the immense number of people involved. It is so in aviation. The number of casualties is remarkably small in comparison with the number of flights made. In the hands of competent men the sailing of an airship should be, and is, freer from risk of accident than the running of a railway train. There are no rails to spread or break, no bridges to collapse, no crossings at which collisions may occur, no chance for some sleepy or overworked employee to misunderstand the dispatcher's orders and cause a wreck. Two Main Causes of Trouble. The two main causes of trouble in an airship leading to disaster may be attributed to the stoppage of the motor, and the aviator becoming rattled so that he loses control of his machine. Modern ingenuity is fast developing motors that almost daily become more and more reliable, and experience is making aviators more and more self-confident in their ability to act wisely and promptly in cases of emergency. Besides this a satisfactory system of automatic control is in a fair way of being perfected. Occasionally even the most experienced and competent of men in all callings become careless and by foolish action invite disaster. This is true of aviators the same as it is of railroaders, men who work in dynamite mills, etc. But in nearly every instance the responsibility rests with the individual; not with the system. There are some men unfitted by nature for aviation, just as there are others unfitted to be railway engineers. CHAPTER XVI. RADICAL CHANGES BEING MADE. Changes, many of them extremely radical in their nature, are continually being made by prominent aviators, and particularly those who have won the greatest amount of success. Wonderful as the results have been few of the aviators are really satisfied. Their successes have merely spurred them on to new endeavors, the ultimate end being the development of an absolutely perfect aircraft. Among the men who have been thus experimenting are the Wright Brothers, who last year (1909) brought out a craft totally different as regards proportions and weight from the one used the preceding year. One marked result was a gain of about 3 1/2 miles an hour in speed. Dimensions of 1908 Machine. The 1908 model aeroplane was 40 by 29 feet over all. The carrying surfaces, that is, the two aerocurves, were 40 by 6 feet, having a parabolical curve of one in twelve. With about 70 square feet of surface in the rudders, the total surface given was about 550 square feet. The engine, which is the invention of the Wright brothers, weighed, approximately, 200 pounds, and gave about 25 horsepower at 1,400 revolutions per minute. The total weight of the aeroplane, exclusive of passenger, but inclusive of engine, was about 1,150 pounds. This result showed a lift of a fraction over 2 1/4 pounds to the square foot of carrying surface. The speed desired was 40 miles an hour, but the machine was found to make only a scant 39 miles an hour. The upright struts were about 7/8-inch thick, the skids, 2 1/2 by 1 1/4 inches thick. Dimensions of 1909 Machine. The 1909 aeroplane was built primarily for greater speed, and relatively heavier; to be less at the mercy of the wind. This result was obtained as follows: The aerocurves, or carrying surfaces, were reduced in dimensions from 40 by 6 feet to 36 by 5 1/2 feet, the curve remaining the same, one in twelve. The upright struts were cut from seven-eighths inch to five-eighths inch, and the skids from two and one-half by one and one-quarter to two and one-quarter by one and three-eighths inches. This result shows that there were some 81 square feet of carrying surface missing over that of last year's model. and some 25 pounds loss of weight. Relatively, though, the 1909 model aeroplane, while actually 25 pounds lighter, is really some 150 pounds heavier in the air than the 1908 model, owing to the lesser square feet of carrying surface. Some of the Results Obtained. Reducing the carrying surfaces from 6 to 5 1/2 feet gave two results--first, less carrying capacity; and, second, less head-on resistance, owing to the fact that the extent of the parabolic curve in the carrying surfaces was shortened. The "head-on" resistance is the retardance the aeroplane meets in passing through the air, and is counted in square feet. In the 1908 model the curve being one in twelve and 6 feet deep, gave 6 inches of head-on resistance. The plane being 40 feet spread, gave 6 inches by 40 feet, or 20 square feet of head-on resistance. Increasing this figure by a like amount for each plane, and adding approximately 10 square feet for struts, skids and wiring, we have a total of approximately, 50 square feet of surface for "head-on" resistance. In the 1909 aeroplane, shortening the curve 6 inches at the parabolic end of the curve took off 1 inch of head-on resistance. Shortening the spread of the planes took off between 3 and 4 square feet of head-on resistance. Add to this the total of 7 square feet, less curve surface and about 1 square foot, less wire and woodwork resistance, and we have a grand total of, approximately, 12 square feet of less "head-on" resistance over the 1908 model. Changes in Engine Action. The engine used in 1909 was the same one used in 1908, though some minor changes were made as improvements; for instance, a make and break spark was used, and a nine-tooth, instead of a ten-tooth magneto gear-wheel was used. This increased the engine revolutions per minute from 1,200 to 1,400, and the propeller revolutions per minute from 350 to 371, giving a propeller thrust of, approximately, 170 foot pounds instead of 153, as was had last year. More Speed and Same Capacity. One unsatisfactory feature of the 1909 model over that of 1908, apparently, was the lack of inherent lateral stability. This was caused by the lesser surface and lesser extent of curvatures at the portions of the aeroplane which were warped. This defect did not show so plainly after Mr. Orville Wright had become fully proficient in the handling of the new machine, and with skillful management, the 1909 model aeroplane will be just as safe and secure as the other though it will take a little more practice to get that same degree of skill. To sum up: The aeroplane used in 1909 was 25 pounds lighter, but really about 150 pounds heavier in the air, had less head-on resistance, and greater propeller thrust. The speed was increased from about 39 miles per hour to 42 1/2 miles per hour. The lifting capacity remained about the same, about 450 pounds capacity passenger-weight, with the 1908 machine. In this respect, the loss of carrying surface was compensated for by the increased speed. During the first few flights it was plainly demonstrated that it would need the highest skill to properly handle the aeroplane, as first one end and then the other would dip and strike the ground, and either tear the canvas or slew the aeroplane around and break a skid. Wrights Adopt Wheeled Gears. In still another important respect the Wrights, so far as the output of one of their companies goes, have made a radical change. All the aeroplanes turned out by the Deutsch Wright Gesellschaft, according to the German publication, _Automobil-Welt_, will hereafter be equipped with wheeled running gears and tails. The plan of this new machine is shown in the illustration on page 145. The wheels are three in number, and are attached one to each of the two skids, just under the front edge of the planes, and one forward of these, attached to a cross-member. It is asserted that with these wheels the teaching of purchasers to operate the machines is much simplified, as the beginners can make short flights on their own account without using the starting derrick. This is a big concession for the Wrights to make, as they have hitherto adhered stoutly to the skid gear. While it is true they do not control the German company producing their aeroplanes, yet the nature of their connection with the enterprise is such that it may be taken for granted no radical changes in construction would be made without their approval and consent. Only Three Dangerous Rivals. Official trials with the 1909 model smashed many records and leave the Wright brothers with only three dangerous rivals in the field, and with basic patents which cover the curve, warp and wing-tip devices found on all the other makes of aeroplanes. These three rivals are the Curtiss and Voisin biplane type and the Bleriot monoplane pattern. The Bleriot monoplane is probably the most dangerous rival, as this make of machine has a record of 54 miles per hour, has crossed the English channel, and has lifted two passengers besides the operator. The latest type of this machine only weighs 771.61 pounds complete, without passengers, and will lift a total passenger weight of 462.97 pounds, which is a lift of 5.21 pounds to the square foot. This is a better result than those published by the Wright brothers, the best noted being 4.25 pounds per square foot. Other Aviators at Work. The Wrights, however, are not alone in their efforts to promote the efficiency of the flying machine. Other competent inventive aviators, notably Curtiss, Voisin, Bleriot and Farman, are close after them. The Wrights, as stated, have a marked advantage in the possession of patents covering surface plane devices which have thus far been found indispensable in flying machine construction. Numerous law suits growing out of alleged infringements of these patents have been started, and others are threatened. What effect these actions will have in deterring aviators in general from proceeding with their experiments remains to be seen. In the meantime the four men named--Curtiss, Voisin, Bleriot and Farman--are going ahead regardless of consequences, and the inventive genius of each is so strong that it is reasonable to expect some remarkable developments in the near future. Smallest of Flying Machines. To Santos Dumont must be given the credit of producing the smallest practical flying machine yet constructed. True, he has done nothing remarkable with it in the line of speed, but he has demonstrated the fact that a large supporting surface is not an essential feature. This machine is named "La Demoiselle." It is a monoplane of the dihedral type, with a main plane on each side of the center. These main planes are of 18 foot spread, and nearly 6 1/2 feet in depth, giving approximately 115 feet of surface area. The total weight is 242 pounds, which is 358 pounds less than any other machine which has been successfully used. The total depth from front to rear is 26 feet. The framework is of bamboo, strengthened and held taut with wire guys. Have One Rule in Mind. In this struggle for mastery in flying machine efficiency all the contestants keep one rule in mind, and this is: "The carrying capacity of an aeroplane is governed by the peripheral curve of its carrying surfaces, plus the speed; and the speed is governed by the thrust of the propellers, less the 'head-on' resistance." Their ideas as to the proper means of approaching the proposition may, and undoubtedly are, at variance, but the one rule in solving the problem of obtaining the greatest carrying capacity combined with the greatest speed, obtains in all instances. CHAPTER XVII. SOME OF THE NEW DESIGNS. Spurred on by the success attained by the more experienced and better known aviators numerous inventors of lesser fame are almost daily producing practical flying machines varying radically in construction from those now in general use. One of these comparatively new designs is the Van Anden biplane, made by Frank Van Anden of Islip, Long Island, a member of the New York Aeronautic Society. While his machine is wholly experimental, many successful short flights were made with it last fall (1909). One flight, made October 19th, 1909, is of particular interest as showing the practicability of an automatic stabilizing device installed by the inventor. The machine was caught in a sudden severe gust of wind and keeled over, but almost immediately righted itself, thus demonstrating in a most satisfactory manner the value of one new attachment. Features of Van Anden Model. In size the surfaces of the main biplane are 26 feet in spread, and 4 feet in depth from front to rear. The upper and lower planes are 4 feet apart. Silkolene coated with varnish is used for the coverings. Ribs (spruce) are curved one inch to the foot, the deepest part of the curve (4 inches) being one foot back from the front edge of the horizontal beam. Struts (also of spruce, as is all the framework) are elliptical in shape. The main beams are in three sections, nearly half round in form, and joined by metal sleeves. There is a two-surface horizontal rudder, 2x2x4 feet, in front. This is pivoted at its lateral center 8 feet from the front edge of the main planes. In the rear is another two-surface horizontal rudder 2x2x2 1/2 feet, pivoted in the same manner as the front one, 15 feet from the rear edges of the main planes. Hinged to the rear central strut of the rear rudder is a vertical rudder 2 feet high by 3 feet in length. The Method of Control. In the operation of these rudders--both front and rear--and the elevation and depression of the main planes, the Curtiss system is employed. Pushing the steering-wheel post outward depresses the front edges of the planes, and brings the machine downward; pulling the steering-wheel post inward elevates the front edges of the planes and causes the machine to ascend. Turning the steering wheel itself to the right swings the tail rudder to the left, and the machine, obeying this like a boat, turns in the same direction as the wheel is turned. By like cause turning the wheel to the left turns the machine to the left. Automatic Control of Wings. There are two wing tips, each of 6 feet spread (length) and 2 feet from front to rear. These are hinged half way between the main surfaces to the two outermost rear struts. Cables run from these to an automatic device working with power from the engine, which automatically operates the tips with the tilting of the machine. Normally the wing tips are held horizontal by stiff springs introduced in the cables outside of the device. It was the successful working of this device which righted the Van Anden craft when it was overturned in the squall of October 19th, 1909. Previous to that occurrence Mr. Van Anden had looked upon the device as purely experimental, and had admitted that he had grave uncertainty as to how it would operate in time of emergency. He is now quoted as being thoroughly satisfied with its practicability. It is this automatic device which gives the Van Anden machine at least one distinctively new feature. While on this subject it will not be amiss to add that Mr. Curtiss does not look kindly on automatic control. "I would rather trust to my own action than that of a machine," he says. This is undoubtedly good logic so far as Mr. Curtiss is concerned, but all aviators are not so cool-headed and resourceful. Motive Power of Van Anden. A 50-horsepower "H-F" water cooled motor drives a laminated wood propeller 6 feet in diameter, with a 17 degree pitch at the extremities, increasing toward the hub. The rear end of the motor is about 6 inches back from the rear transverse beam and the engine shaft is in a direct line with the axes of the two horizontal rudders. An R. I. V. ball bearing carries the shaft at this point. Flying, the motor turns at about 800 revolutions per minute, delivering 180 pounds pull. A test of the motor running at 1,200 showed a pull of 250 pounds on the scales. Still Another New Aeroplane. Another new aeroplane is that produced by A. M. Herring (an old-timer) and W. S. Burgess, under the name of the Herring-Burgess. This is also equipped with an automatic stability device for maintaining the balance transversely. The curvature of the planes is also laid out on new lines. That this new plan is effective is evidenced by the fact that the machine has been elevated to an altitude of 40 feet by using one-half the power of the 30-horsepower motor. The system of rudder and elevation control is very simple. The aviator sits in front of the lower plane, and extending his arms, grasps two supports which extend down diagonally in front. On the under side of these supports just beneath his fingers are the controls which operate the vertical rudder, in the rear. Thus, if he wishes to turn to the right, he presses the control under the fingers of his right hand; if to the left, that under the fingers of his left hand. The elevating rudder is operated by the aviator's right foot, the control being placed on a foot-rest. Motor Is Extremely Light. Not the least notable feature of the craft is its motor. Although developing, under load, 30-horsepower, or that of an ordinary automobile, it weighs, complete, hardly 100 pounds. Having occasion to move it a little distance for inspection, Mr. Burgess picked it up and walked off with it--cylinders, pistons, crankcase and all, even the magneto, being attached. There are not many 30-horsepower engines which can be so handled. Everything about it is reduced to its lowest terms of simplicity, and hence, of weight. A single camshaft operates not only all of the inlet and exhaust valves, but the magneto and gear water pump, as well. The motor is placed directly behind the operator, and the propeller is directly mounted on the crankshaft. This weight of less than 100 pounds, it must be remembered, is not for the motor alone; it includes the entire power plant equipment. The "thrust" of the propeller is also extraordinary, being between 250 and 260 pounds. The force of the wind displacement is strong enough to knock down a good-sized boy as one youngster ascertained when he got behind the propeller as it was being tested. He was not only knocked down but driven for some distance away from the machine. The propeller has four blades which are but little wider than a lath. Machine Built by Students. Students at the University of Pennsylvania, headed by Laurence J. Lesh, a protege of Octave Chanute, have constructed a practical aeroplane of ordinary maximum size, in which is incorporated many new ideas. The most unique of these is to be found in the steering gear, and the provision made for the accommodation of a pupil while taking lessons under an experienced aviator. Immediately back of the aviator is an extra seat and an extra steering wheel which works in tandem style with the front wheel. By this arrangement a beginner may be easily and quickly taught to have perfect control of the machine. These tandem wheels are also handy for passengers who may wish to operate the car independently of one another, it being understood, of course, that there will be no conflict of action. Frame Size and Engine Power. The frame has 36 feet spread and measures 35 feet from the front edge to the end of the tail in the rear. It is equipped with two rear propellers operated by a Ramsey 8-cylinder motor of 50 horsepower, placed horizontally across the lower plane, with the crank shaft running clear through the engine. The "Pennsylvania I" is the first two-propeller biplane chainless car, this scheme having been adopted in order to avoid the crossing of chains. The lateral control is by a new invention by Octave Chanute and Laurence J. Lesh, for which Lesh is now applying for a patent. The device was worked out before the Wright brothers' suit was begun, and is said to be superior to the Wright warping or the Curtiss ailerons. The landing device is also new in design. This aeroplane will weigh about 1,500 pounds, and will carry fuel for a flight of 150 miles, and it is expected to attain a speed of at least 45 miles an hour. There are others, lots of them, too numerous in fact to admit of mention in a book of this size. CHAPTER XVIII. DEMAND FOR FLYING MACHINES. As a commercial proposition the manufacture and sale of motor-equipped aeroplanes is making much more rapid advance than at first obtained in the similar handling of the automobile. Great, and even phenomenal, as was the commercial development of the motor car, that of the flying machine is even greater. This is a startling statement, but it is fully warranted by the facts. It is barely more than a year ago (1909) that attention was seriously attracted to the motor-equipped aeroplane as a vehicle possible of manipulation by others than professional aviators. Up to that time such actual flights as were made were almost exclusively with the sole purpose of demonstrating the practicability of the machine, and the merits of the ideas as to shape, engine power, etc., of the various producers. Results of Bleriot's Daring. It was not until Bleriot flew across the straits of Dover on July 25th, 1909, that the general public awoke to a full realization of the fact that it was possible for others than professional aviators to indulge in aviation. Bleriot's feat was accepted as proof that at last an absolutely new means of sport, pleasure and research, had been practically developed, and was within the reach of all who had the inclination, nerve and financial means to adopt it. From this event may be dated the birth of the modern flying machine into the world of business. The automobile was taken up by the general public from the very start because it was a proposition comparatively easy of demonstration. There was nothing mysterious or uncanny in the fact that a wheeled vehicle could be propelled on solid, substantial roads by means of engine power. And yet it took (comparatively speaking) a long time to really popularize the motor car. Wonderful Results in a Year. Men of large financial means engaged in the manufacture of automobiles, and expended fortunes in attracting public attention to them through the medium of advertisements, speed and road contests, etc. By these means a mammoth business has been built up, but bringing this business to its present proportions required years of patient industry and indomitable pluck. At this writing, less than a year from the day when Bleriot crossed the channel, the actual sales of flying machines outnumber the actual sales of automobiles in the first year of their commercial development. This may appear incredible, but it is a fact as statistics will show. In this connection we should take into consideration the fact that up to a year ago there was no serious intention of putting flying machines on the market; no preparations had been made to produce them on a commercial scale; no money had been expended in advertisements with a view to selling them. Some of the Actual Results. Today flying machines are being produced on a commercial basis, and there is a big demand for them. The people making them are overcrowded with orders. Some of the producers are already making arrangements to enlarge their plants and advertise their product for sale the same as is being done with automobiles, while a number of flying machine motor makers are already promoting the sale of their wares in this way. Here are a few actual figures of flying machine sales made by the more prominent producers since July 25th, 1909. Santos Dumont, 90 machines; Bleriot, 200; Farman, 130; Clemenceau-Wright, 80; Voisin, 100; Antoinette, 100. Many of these orders have been filled by delivery of the machines, and in others the construction work is under way. The foregoing are all of foreign make. In this country Curtiss and the Wrights are engaged in similar work, but no actual figures of their output are obtainable. Larger Plants Are Necessary. And this situation exists despite the fact that none of the producers are really equipped with adequate plants for turning out their machines on a modern, business-like basis. The demand was so sudden and unexpected that it found them poorly prepared to meet it. This, however, is now being remedied by the erection of special plants, the enlargement of others, and the introduction of new machinery and other labor-saving conveniences. Companies, with large capitalization, to engage in the exclusive production of airships are being organized in many parts of the world. One notable instance of this nature is worth quoting as illustrative of the manner in which the production of flying machines is being commercialized. This is the formation at Frankfort, Germany, of the Flugmaschine Wright, G. m. b. H., with a capital of $119,000, the Krupps, of Essen, being interested. Prices at Which Machines Sell. This wonderful demand from the public has come notwithstanding the fact that the machines, owing to lack of facilities for wholesale production, are far from being cheap. Such definite quotations as are made are on the following basis: Santos Dumont--List price $1,000, but owing to the rush of orders agents are readily getting from $1,300 to $1,500. This is the smallest machine made. Bleriot--List price $2,500. This is for the cross-channel type, with Anzani motor. Antoinette--List price from $4,000 to $5,000, according to size. Wright--List price $5,600. Curtiss--List price $5,000. There is, however, no stability in prices as purchasers are almost invariably ready to pay a considerable premium to facilitate delivery. The motor is the most expensive part of the flying machine. Motor prices range from $500 to $2,000, this latter amount being asked for the Curtiss engine. Systematic Instruction of Amateurs. In addition to the production of flying machines many of the experienced aviators are making a business of the instruction of amateurs. Curtiss and the Wrights in this country have a number of pupils, as have also the prominent foreigners. Schools of instruction are being opened in various parts of the world, not alone as private money-making ventures, but in connection with public educational institutions. One of these latter is to be found at the University of Barcelona, Spain. The flying machine agent, the man who handles the machines on a commission, has also become a known quantity, and will soon be as numerous as his brother of the automobile. The sign "John Bird, agent for Skimmer's Flying Machine," is no longer a curiosity. Yes, the Airship Is Here. From all of which we may well infer that the flying machine in practical form has arrived, and that it is here to stay. It is no exaggeration to say that the time is close at hand when people will keep flying machines just as they now keep automobiles, and that pleasure jaunts will be fully as numerous and popular. With the important item of practicability fully demonstrated, "Come, take a trip in my airship," will have more real significance than now attaches to the vapid warblings of the vaudeville vocalist. As a further evidence that the airship is really here, and that its presence is recognized in a business way, the action of life and accident insurance companies is interesting. Some of them are reconstructing their policies so as to include a special waiver of insurance by aviators. Anything which compels these great corporations to modify their policies cannot be looked upon as a mere curiosity or toy. It is some consolation to know that the movement in this direction is not thus far widespread. Moreover it is more than probable that the competition for business will eventually induce the companies to act more liberally toward aviators, especially as the art of aviation advances. CHAPTER XIX. LAW OF THE AIRSHIP. Successful aviation has evoked some peculiar things in the way of legal action and interpretation of the law. It is well understood that a man's property cannot be used without his consent. This is an old established principle in common law which holds good today. The limits of a man's property lines, however, have not been so well understood by laymen. According to eminent legal authorities such as Blackstone, Littleton and Coke, the "fathers of the law," the owner of realty also holds title above and below the surface, and this theory is generally accepted without question by the courts. Rights of Property Owners. In other words the owner of realty also owns the sky above it without limit as to distance. He can dig as deep into his land, or go as high into the air as he desires, provided he does not trespass upon or injure similar rights of others. The owner of realty may resist by force, all other means having failed, any trespass upon, or invasion of his property. Other people, for instance, may not enter upon it, or over or under it, without his express permission and consent. There is only one exception, and this is in the case of public utility corporations such as railways which, under the law of eminent domain, may condemn a right of way across the property of an obstinate owner who declines to accept a fair price for the privilege. Privilege Sharply Confined. The law of eminent domain may be taken advantage of only by corporations which are engaged in serving the public. It is based upon the principle that the advancement and improvement of a community is of more importance and carries with it more rights than the interests of the individual owner. But even in cases where the right of eminent domain is exercised there can be no confiscation of the individual's property. Exercising the right of eminent domain is merely obtaining by public purchase what is held to be essential to the public good, and which cannot be secured by private purchase. When eminent domain proceedings are resorted to the court appoints appraisers who determine upon the value of the property wanted, and this value (in money) is paid to the owner. How It Affects Aviation. It should be kept in mind that this privilege of the "right of eminent domain" is accorded only to corporations which are engaged in serving the public. Individuals cannot take advantage of it. Thus far all aviation has been conducted by individuals; there are no flying machine or airship corporations regularly engaged in the transportation of passengers, mails or freight. This leads up to the question "What would happen if realty owners generally, or in any considerable numbers, should prohibit the navigation of the air above their holdings?" It is idle to say such a possibility is ridiculous--it is already an actuality in a few individual instances. One property owner in New Jersey, a justice of the peace, maintains a large sign on the roof of his house warning aviators that they must not trespass upon his domain. That he is acting well within his rights in doing this is conceded by legal authorities. Hard to Catch Offenders. But, suppose the alleged trespass is committed, what is the property owner going to do about it? He must first catch the trespasser and this would be a pretty hard job. He certainly could not overtake him, unless he kept a racing aeroplane for this special purpose. It would be equally difficult to identify the offender after the offense had been committed, even if he were located, as aeroplanes carry no license numbers. Allowing that the offender should be caught the only recourse of the realty owner is an action for damages. He may prevent the commission of the offense by force if necessary, but after it is committed he can only sue for damages. And in doing this he would have a lot of trouble. Points to Be Proven. One of the first things the plaintiff would be called upon to prove would be the elevation of the machine. If it were reasonably close to the ground there would, of course, be grave risk of damage to fences, shrubbery, and other property, and the court would be justified in holding it to be a nuisance that should be suppressed. If, on the other hand; the machine was well up in the air, but going slowly, or hovering over the plaintiff's property, the court might be inclined to rule that it could not possibly be a nuisance, but right here the court would be in serious embarrassment. By deciding that it was not a nuisance he would virtually override the law against invasion of a man's property without his consent regardless of the nature of the invasion. By the same decision he would also say in effect that, if one flying machine could do this a dozen or more would have equal right to do the same thing. While one machine hovering over a certain piece of property may be no actual nuisance a dozen or more in the same position could hardly be excused. Difficult to Fix Damages. Such a condition would tend to greatly increase the risk of accident, either through collision, or by the carelessness of the aviators in dropping articles which might cause damages to the people or property below. In such a case it would undoubtedly be a nuisance, and in addition to a fine, the offender would also be liable for the damages. Taking it for granted that no actual damage is done, and the owner merely sues on account of the invasion of his property, how is the amount of compensation to be fixed upon? The owner has lost nothing; no part of his possessions has been taken away; nothing has been injured or destroyed; everything is left in exactly the same condition as before the invasion. And yet, if the law is strictly interpreted, the offender is liable. Right of Way for Airships. Somebody has suggested the organization of flying-machine corporations as common carriers, which would give them the right of eminent domain with power to condemn a right of way. But what would they condemn? There is nothing tangible in the air. Railways in condemning a right of way specify tangible property (realty) within certain limits. How would an aviator designate any particular right of way through the air a certain number of feet in width, and a certain distance from the ground? And yet, should the higher courts hold to the letter of the law and decide that aviators have no right to navigate their craft over private property, something will have to be done to get them out of the dilemma, as aviation is too far advanced to be discarded. Fortunately there is little prospect of any widespread antagonism among property owners so long as aviators refrain from making nuisances of themselves. Possible Solution Offered. One possible solution is offered and that is to confine the path of airships to the public highways so that nobody's property rights would be invaded. In addition, as a matter of promoting safety for both operators and those who may happen to be beneath the airships as they pass over a course, adoption of the French rules are suggested. These are as follows: Aeroplanes, when passing, must keep to the right, and pass at a distance of at least 150 feet. They are free from this rule when flying at altitudes of more than 100 feet. Every machine when flying at night or during foggy weather must carry a green light on the right, and a red light on the left, and a white headlight on the front. These are sensible rules, but may be improved upon by the addition of a signal system of some kind, either horn, whistle or bell. Responsibility of Aviators. Mr. Jay Carver Bossard, in recent numbers of _Fly_, brings out some curious and interesting legal points in connection with aviation, among which are the following: "Private parties who possess aerial craft, and desire to operate the same in aerial territory other than their own, must obtain from land owners special permission to do so, such permission to be granted only by agreement, founded upon a valid consideration. Otherwise, passing over another's land will in each instance amount to a trespass. "Leaving this highly technical side of the question, let us turn to another view: the criminal and tort liability of owners and operators to airship passengers. If A invites B to make an ascension with him in his machine, and B, knowing that A is merely an enthusiastic amateur and far from being an expert, accepts and is through A's innocent negligence injured, he has no grounds for recovery. But if A contracts with B, to transport him from one place to another, for a consideration, and B is injured by the poor piloting of A, A would be liable to B for damages which would result. Now in order to safeguard such people as B, curious to the point of recklessness, the law will have to require all airship operators to have a license, and to secure this license airship pilots will have to meet certain requirements. Here again is a question. Who is going to say whether an applicant is competent to pilot a balloon or airship? Fine for an Aeronaut. "An aeroplane while maneuvering is suddenly caught by a treacherous gale and swept to the ground. A crowd of people hasten over to see if the aeronaut is injured, and in doing so trample over Tax-payer Smith's garden, much to the detriment of his growing vegetables and flowers. Who is liable for the damages? Queer as it may seem, a case very similar to this was decided in 1823, in the New York supreme court, and it was held that the aeronaut was liable upon the following grounds: 'To render one man liable in trespass for the acts of others, it must appear either that they acted in concert, or that the act of the one, ordinarily and naturally produced the acts of the others, Ascending in a balloon is not an unlawful act, but it is certain that the aeronaut has no control over its motion horizontally, but is at the sport of the wind, and is to descend when and how he can. His reaching the earth is a matter of hazard. If his descent would according to the circumstances draw a crowd of people around him, either out of curiosity, or for the purpose of rescuing him from a perilous situation, all this he ought to have foreseen, and must be responsible for.' Air Not Really Free. "The general belief among people is, that the air is free. Not only free to breathe and enjoy, but free to travel in, and that no one has any definite jurisdiction over, or in any part of it. Now suppose this were made a legal doctrine. Would a murder perpetrated above the clouds have to go unpunished? Undoubtedly. For felonies committed upon the high seas ample provision is made for their punishment, but new provisions will have to be made for crimes committed in the air. Relations of Owner and Employee. "It is a general rule of law that a master is bound to provide reasonably safe tools, appliances and machines for his servant. How this rule is going to be applied in cases of aeroplanes, remains to be seen. The aeroplane owner who hires a professional aeronaut, that is, one who has qualified as an expert, owes him very little legal duty to supply him with a perfect aeroplane. The expert is supposed to know as much regarding the machine as the owner, if not more, and his acceptance of his position relieves the owner from liability. When the owner hires an amateur aeronaut to run the aeroplane, and teaches him how to manipulate it, even though the prescribed manner of manipulation will make flight safe, nevertheless if the machine is visibly defective, or known to be so, any injury which results to the aeronaut the owner is liable for. As to Aeroplane Contracts. "At the present time there are many orders being placed with aeroplane manufacturing companies. There are some unique questions to be raised here under the law of contract. It is an elementary principle of law that no one can be compelled to complete a contract which in itself is impossible to perform. For instance, a contract to row a boat across the Atlantic in two weeks, for a consideration, could never be enforced because it is within judicial knowledge that such an undertaking is beyond human power. Again, contracts formed for the doing of acts contrary to nature are never enforcible, and here is where our difficulty comes in. Is it possible to build a machine or species of craft which will transport a person or goods through the air? The courts know that balloons are practical; that is, they know that a bag filled with gas has a lifting power and can move through the air at an appreciable height. Therefore, a contract to transport a person in such manner is a good contract, and the conditions being favorable could undoubtedly be enforced. But the passengers' right of action for injury would be very limited. No Redress for Purchasers. "In the case of giving warranties on aeroplanes, we have yet to see just what a court is going to say. It is easy enough for a manufacturer to guarantee to build a machine of certain dimensions and according to certain specifications, but when he inserts a clause in the contract to the effect that the machine will raise itself from the surface of the earth, defy the laws of gravity, and soar in the heavens at the will of the aviator, he is to say the least contracting to perform a miracle. "Until aeroplanes have been made and accepted as practical, no court will force a manufacturer to turn out a machine guaranteed to fly. So purchasers can well remember that if their machines refuse to fly they have no redress against the maker, for he can always say, 'The industry is still in its experimental stage.' In contracting for an engine no builder will guarantee that the particular engine will successfully operate the aeroplane. In fact he could never be forced to live up to such an agreement, should he agree to a stipulation of that sort. The best any engine maker will guarantee is to build an engine according to specifications." CHAPTER XX. SOARING FLIGHT. By Octave Chanute. [5] There is a wonderful performance daily exhibited in southern climes and occasionally seen in northerly latitudes in summer, which has never been thoroughly explained. It is the soaring or sailing flight of certain varieties of large birds who transport themselves on rigid, unflapping wings in any desired direction; who in winds of 6 to 20 miles per hour, circle, rise, advance, return and remain aloft for hours without a beat of wing, save for getting under way or convenience in various maneuvers. They appear to obtain from the wind alone all the necessary energy, even to advancing dead against that wind. This feat is so much opposed to our general ideas of physics that those who have not seen it sometimes deny its actuality, and those who have only occasionally witnessed it subsequently doubt the evidence of their own eyes. Others, who have seen the exceptional performances, speculate on various explanations, but the majority give it up as a sort of "negative gravity." Soaring Power of Birds. The writer of this paper published in the "Aeronautical Annual" for 1896 and 1897 an article upon the sailing flight of birds, in which he gave a list of the authors who had described such flight or had advanced theories for its explanation, and he passed these in review. He also described his own observations and submitted some computations to account for the observed facts. These computations were correct as far as they went, but they were scanty. It was, for instance, shown convincingly by analysis that a gull weighing 2.188 pounds, with a total supporting surface of 2.015 square feet, a maximum body cross-section of 0.126 square feet and a maximum cross-section of wing edges of 0.098 square feet, patrolling on rigid wings (soaring) on the weather side of a steamer and maintaining an upward angle or attitude of 5 degrees to 7 degrees above the horizon, in a wind blowing 12.78 miles an hour, which was deflected upward 10 degrees to 20 degrees by the side of the steamer (these all being carefully observed facts), was perfectly sustained at its own "relative speed" of 17.88 miles per hour and extracted from the upward trend of the wind sufficient energy to overcome all the resistances, this energy amounting to 6.44 foot-pounds per second. Great Power of Gulls. It was shown that the same bird in flapping flight in calm air, with an attitude or incidence of 3 degrees to 5 degrees above the horizon and a speed of 20.4 miles an hour was well sustained and expended 5.88 foot-pounds per second, this being at the rate of 204 pounds sustained per horsepower. It was stated also that a gull in its observed maneuvers, rising up from a pile head on unflapping wings, then plunging forward against the wind and subsequently rising higher than his starting point, must either time his ascents and descents exactly with the variations in wind velocities, or must meet a wind billow rotating on a horizontal axis and come to a poise on its crest, thus availing of an ascending trend. But the observations failed to demonstrate that the variations of the wind gusts and the movements of the bird were absolutely synchronous, and it was conjectured that the peculiar shape of the soaring wing of certain birds, as differentiated from the flapping wing, might, when experimented upon, hereafter account for the performance. Mystery to be Explained. These computations, however satisfactory they were for the speed of winds observed, failed to account for the observed spiral soaring of buzzards in very light winds and the writer was compelled to confess: "Now, this spiral soaring in steady breezes of 5 to 10 miles per hour which are apparently horizontal, and through which the bird maintains an average speed of about 20 miles an hour, is the mystery to be explained. It is not accounted for, quantitatively, by any of the theories which have been advanced, and it is the one performance which has led some observers to claim that it was done through 'aspiration.' i, e., that a bird acted upon by a current, actually drew forward into that current against its exact direction of motion." Buzzards Soar in Dead Calm. A still greater mystery was propounded by the few observers who asserted that they had seen buzzards soaring in a dead calm, maintaining their elevation and their speed. Among these observers was Mr. E. C. Huffaker, at one time assistant experimenter for Professor Langley. The writer believed and said then that he must in some way have been mistaken, yet, to satisfy himself, he paid several visits to Mr. Huffaker, in Eastern Tennessee and took along his anemometer. He saw quite a number of buzzards sailing at a height of 75 to 100 feet in breezes measuring 5 or 6 miles an hour at the surface of the ground, and once he saw one buzzard soaring apparently in a dead calm. The writer was fairly baffled. The bird was not simply gliding, utilizing gravity or acquired momentum, he was actually circling horizontally in defiance of physics and mathematics. It took two years and a whole series of further observations to bring those two sciences into accord with the facts. Results of Close Observations. Curiously enough the key to the performance of circling in a light wind or a dead calm was not found through the usual way of gathering human knowledge, i. e., through observations and experiment. These had failed because I did not know what to look for. The mystery was, in fact, solved by an eclectic process of conjecture and computation, but once these computations indicated what observations should be made, the results gave at once the reasons for the circling of the birds, for their then observed attitude, and for the necessity of an independent initial sustaining speed before soaring began. Both Mr. Huffaker and myself verified the data many times and I made the computations. These observations disclosed several facts: 1st.--That winds blowing five to seventeen miles per hour frequently had rising trends of 10 degrees to 15 degrees, and that upon occasions when there seemed to be absolutely no wind, there was often nevertheless a local rising of the air estimated at a rate of four to eight miles or more per hour. This was ascertained by watching thistledown, and rising fogs alongside of trees or hills of known height. Everyone will readily realize that when walking at the rate of four to eight miles an hour in a dead calm the "relative wind" is quite inappreciable to the senses and that such a rising air would not be noticed. 2nd.--That the buzzard, sailing in an apparently dead horizontal calm, progressed at speeds of fifteen to eighteen miles per hour, as measured by his shadow on the ground. It was thought that the air was then possibly rising 8.8 feet per second, or six miles per hour. 3rd.--That when soaring in very light winds the angle of incidence of the buzzards was negative to the horizon--i. e., that when seen coming toward the eye, the afternoon light shone on the back instead of on the breast, as would have been the case had the angle been inclined above the horizon. 4th.--That the sailing performance only occurred after the bird had acquired an initial velocity of at least fifteen or eighteen miles per hour, either by industrious flapping or by descending from a perch. An Interesting Experiment. 5th.--That the whole resistance of a stuffed buzzard, at a negative angle of 3 degrees in a current of air of 15.52 miles per hour, was 0.27 pounds. This test was kindly made for the writer by Professor A. F. Zahm in the "wind tunnel" of the Catholic University at Washington, D. C., who, moreover, stated that the resistance of a live bird might be less, as the dried plumage could not be made to lie smooth. This particular buzzard weighed in life 4.25 pounds, the area of his wings and body was 4.57 square feet, the maximum cross-section of his body was 0.110 square feet, and that of his wing edges when fully extended was 0.244 square feet. With these data, it became surprisingly easy to compute the performance with the coefficients of Lilienthal for various angles of incidence and to demonstrate how this buzzard could soar horizontally in a dead horizontal calm, provided that it was not a vertical calm, and that the air was rising at the rate of four or six miles per hour, the lowest observed, and quite inappreciable without actual measuring. Some Data on Bird Power. The most difficult case is purposely selected. For if we assume that the bird has previously acquired an initial minimum speed of seventeen miles an hour (24.93 feet per second, nearly the lowest measured), and that the air was rising vertically six miles an hour (8.80 feet per second), then we have as the trend of the "relative wind" encountered: 6 -- = 0.353, or the tangent of 19 degrees 26'. 17 which brings the case into the category of rising wind effects. But the bird was observed to have a negative angle to the horizon of about 3 degrees, as near as could be guessed, so that his angle of incidence to the "relative wind" was reduced to 16 degrees 26'. The relative speed of his soaring was therefore: Velocity = square root of (17 squared + 6 squared) = 18.03 miles per hour. At this speed, using the Langley co-efficient recently practically confirmed by the accurate experiments of Mr. Eiffel, the air pressure would be: 18.03 squared X 0.00327 = 1.063 pounds per square foot. If we apply Lilienthal's co-efficients for an angle of 6 degrees 26', we have for the force in action: Normal: 4.57 X 1.063 X 0.912 = 4.42 pounds. Tangential: 4.57 X 1.063 X 0.074 = - 0.359 pounds, which latter, being negative, is a propelling force. Results Astonish Scientists. Thus we have a bird weighing 4.25 pounds not only thoroughly supported, but impelled forward by a force of 0.359 pounds, at seventeen miles per hour, while the experiments of Professor A. F. Zahm showed that the resistance at 15.52 miles per hour was only 0.27 pounds, 17 squared or 0.27 X ------- = 0.324 pounds, at seventeen miles an 15.52 squared hour. These are astonishing results from the data obtained, and they lead to the inquiry whether the energy of the rising air is sufficient to make up the losses which occur by reason of the resistance and friction of the bird's body and wings, which, being rounded, do not encounter air pressures in proportion to their maximum cross-section. We have no accurate data upon the co-efficients to apply and estimates made by myself proved to be much smaller than the 0.27 pounds resistance measured by Professor Zahm, so that we will figure with the latter as modified. As the speed is seventeen miles per hour, or 24.93 feet per second, we have for the work: Work done, 0.324 X 24.93 = 8.07 foot pounds per second. Endorsed by Prof. Marvin. Corresponding energy of rising air is not sufficient at four miles per hour. This amounts to but 2.10 foot pounds per second, but if we assume that the air was rising at the rate of seven miles per hour (10.26 feet per second), at which the pressure with the Langley coefficient would be 0.16 pounds per square foot, we have on 4.57 square feet for energy of rising air: 4.57 X 0.16 X 10.26 = 7.50 foot pounds per second, which is seen to be still a little too small, but well within the limits of error, in view of the hollow shape of the bird's wings, which receive greater pressure than the flat planes experimented upon by Langley. These computations were chiefly made in January, 1899, and were communicated to a few friends, who found no fallacy in them, but thought that few aviators would understand them if published. They were then submitted to Professor C. F. Marvin of the Weather Bureau, who is well known as a skillful physicist and mathematician. He wrote that they were, theoretically, entirely sound and quantitatively, probably, as accurate as the present state of the measurements of wind pressures permitted. The writer determined, however, to withhold publication until the feat of soaring flight had been performed by man, partly because he believed that, to ensure safety, it would be necessary that the machine should be equipped with a motor in order to supplement any deficiency in wind force. Conditions Unfavorable for Wrights. The feat would have been attempted in 1902 by Wright brothers if the local circumstances had been more favorable. They were experimenting on "Kill Devil Hill," near Kitty Hawk, N. C. This sand hill, about 100 feet high, is bordered by a smooth beach on the side whence come the sea breezes, but has marshy ground at the back. Wright brothers were apprehensive that if they rose on the ascending current of air at the front and began to circle like the birds, they might be carried by the descending current past the back of the hill and land in the marsh. Their gliding machine offered no greater head resistance in proportion than the buzzard, and their gliding angles of descent are practically as favorable, but the birds performed higher up in the air than they. Langley's Idea of Aviation. Professor Langley said in concluding his paper upon "The Internal Work of the Wind": "The final application of these principles to the art of aerodromics seems, then, to be, that while it is not likely that the perfected aerodrome will ever be able to dispense altogether with the ability to rely at intervals on some internal source of power, it will not be indispensable that this aerodrome of the future shall, in order to go any distance--even to circumnavigate the globe without alighting--need to carry a weight of fuel which would enable it to perform this journey under conditions analogous to those of a steamship, but that the fuel and weight need only be such as to enable it to take care of itself in exceptional moments of calm." Now that dynamic flying machines have been evolved and are being brought under control, it seems to be worth while to make these computations and the succeeding explanations known, so that some bold man will attempt the feat of soaring like a bird. The theory underlying the performance in a rising wind is not new, it has been suggested by Penaud and others, but it has attracted little attention because the exact data and the maneuvers required were not known and the feat had not yet been performed by a man. The puzzle has always been to account for the observed act in very light winds, and it is hoped that by the present selection of the most difficult case to explain--i. e., the soaring in a dead horizontal calm--somebody will attempt the exploit. Requisites for Soaring Flights. The following are deemed to be the requisites and maneuvers to master the secrets of soaring flight: 1st--Develop a dynamic flying machine weighing about one pound per square foot of area, with stable equilibrium and under perfect control, capable of gliding by gravity at angles of one in ten (5 3/4 degrees) in still air. 2nd.--Select locations where soaring birds abound and occasions where rising trends of gentle winds are frequent and to be relied on. 3rd.--Obtain an initial velocity of at least 25 feet per second before attempting to soar. 4th.--So locate the center of gravity that the apparatus shall assume a negative angle, fore and aft, of about 3 degrees. Calculations show, however, that sufficient propelling force may still exist at 0 degrees, but disappears entirely at +4 degrees. 5th.--Circle like the bird. Simultaneously with the steering, incline the apparatus to the side toward which it is desired to turn, so that the centrifugal force shall be balanced by the centripetal force. The amount of the required inclination depends upon the speed and on the radius of the circle swept over. 6th.--Rise spirally like the bird. Steer with the horizontal rudder, so as to descend slightly when going with the wind and to ascend when going against the wind. The bird circles over one spot because the rising trends of wind are generally confined to small areas or local chimneys, as pointed out by Sir H. Maxim and others. 7th.--Once altitude is gained, progress may be made in any direction by gliding downward by gravity. The bird's flying apparatus and skill are as yet infinitely superior to those of man, but there are indications that within a few years the latter may evolve more accurately proportioned apparatus and obtain absolute control over it. It is hoped, therefore, that if there be found no radical error in the above computations, they will carry the conviction that soaring flight is not inaccessible to man, as it promises great economies of motive power in favorable localities of rising winds. The writer will be grateful to experts who may point out any mistake committed in data or calculations, and will furnish additional information to any aviator who may wish to attempt the feat of soaring. CHAPTER XXI. FLYING MACHINES VS. BALLOONS. While wonderful success has attended the development of the dirigible (steerable) balloon the most ardent advocates of this form of aerial navigation admit that it has serious drawbacks. Some of these may be described as follows: Expense and Other Items. Great Initial Expense.--The modern dirigible balloon costs a fortune. The Zeppelin, for instance, costs more than $100,000 (these are official figures). Expense of Inflation.--Gas evaporates rapidly, and a balloon must be re-inflated, or partially re-inflated, every time it is used. The Zeppelin holds 460,000 cubic feet of gas which, even at $1 per thousand, would cost $460. Difficulty of Obtaining Gas.--If a balloon suddenly becomes deflated, by accident or atmospheric conditions, far from a source of gas supply, it is practically worthless. Gas must be piped to it, or the balloon carted to the gas house--an expensive proceeding in either event. Lack of Speed and Control. Lack of Speed.--Under the most favorable conditions the maximum speed of a balloon is 30 miles an hour. Its great bulk makes the high speed attained by flying machines impossible. Difficulty of Control.--While the modern dirigible balloon is readily handled in calm or light winds, its bulk makes it difficult to control in heavy winds. The Element of Danger.--Numerous balloons have been destroyed by lightning and similar causes. One of the largest of the Zeppelins was thus lost at Stuttgart in 1908. Some Balloon Performances. It is only a matter of fairness to state that, under favorable conditions, some very creditable records have been made with modern balloons, viz: November 23d, 1907, the French dirigible Patrie, travelled 187 miles in 6 hours and 45 minutes against a light wind. This was a little over 28 miles an hour. The Clement-Bayard, another French machine, sold to the Russian government, made a trip of 125 miles at a rate of 27 miles an hour. Zeppelin No. 3, carrying eight passengers, and having a total lifting capacity of 5,500 pounds of ballast in addition to passengers, weight of equipment, etc., was tested in October, 1906, and made 67 miles in 2 hours and 17 minutes, about 30 miles an hour. These are the best balloon trips on record, and show forcefully the limitations of speed, the greatest being not over 30 miles an hour. Speed of Flying Machines. Opposed to the balloon performances we have flying machine trips (of authentic records) as follows: Bleriot--monoplane--in 1908--52 miles an hour. Delagrange--June 22, 1908--10 1/2 miles in 16 minutes, approximately 42 miles an hour. Wrights--October, 1905--the machine was then in its infancy--24 miles in 38 minutes, approximately 44 miles an hour. On December 31, 1908, the Wrights made 77 miles in 2 hours and 20 minutes. Lambert, a pupil of the Wrights, and using a Wright biplane, on October 18, 1909, covered 29.82 miles in 49 minutes and 39 seconds, being at the rate of 36 miles an hour. This flight was made at a height of 1,312 feet. Latham--October 21, 1909--made a short flight, about 11 minutes, in the teeth of a 40 mile gale, at Blackpool, Eng. He used an Antoniette monoplane, and the official report says: "This exhibition of nerve, daring and ability is unparalled in the history of aviation." Farman--October 20, 1909--was in the air for 1 hour, 32 min., 16 seconds, travelling 47 miles, 1,184 yards, a duration record for England. Paulhan--January 18, 1901--47 1/2 miles at the rate of 45 miles an hour, maintaining an altitude of from 1,000 to 2,000 feet. Expense of Producing Gas. Gas is indispensable in the operation of dirigible balloons, and gas is expensive. Besides this it is not always possible to obtain it in sufficient quantities even in large cities, as the supply on hand is generally needed for regular customers. Such as can be had is either water or coal gas, neither of which is as efficient in lifting power as hydrogen. Hydrogen is the lightest and consequently the most buoyant of all known gases. It is secured commercially by treating zinc or iron with dilute sulphuric or hydrochloric acid. The average cost may be safely placed at $10 per 1,000 feet so that, to inflate a balloon of the size of the Zeppelin, holding 460,000 cubic feet, would cost $4,600. Proportions of Materials Required. In making hydrogen gas it is customary to allow 20 per cent for loss between the generation and the introduction of the gas into the balloon. Thus, while the formula calls for iron 28 times heavier than the weight of the hydrogen required, and acid 49 times heavier, the real quantities are 20 per cent greater. Hydrogen weighs about 0.09 ounce to the cubic foot. Consequently if we need say 450,000 cubic feet of gas we must have 2,531.25 pounds in weight. To produce this, allowing for the 20 percent loss, we must have 35 times its weight in iron, or over 44 tons. Of acid it would take 60 times the weight of the gas, or nearly 76 tons. In Time of Emergency. These figures are appalling, and under ordinary conditions would be prohibitive, but there are times when the balloon operator, unable to obtain water or coal gas, must foot the bills. In military maneuvers, where the field of operation is fixed, it is possible to furnish supplies of hydrogen gas in portable cylinders, but on long trips where sudden leakage or other cause makes descent in an unexpected spot unavoidable, it becomes a question of making your own hydrogen gas or deserting the balloon. And when this occurs the balloonist is up against another serious proposition--can he find the necessary zinc or iron? Can he get the acid? Balloons for Commercial Use. Despite all this the balloon has its uses. If there is to be such a thing as aerial navigation in a commercial way--the carrying of freight and passengers--it will come through the employment of such monster balloons as Count Zeppelin is building. But even then the carrying capacity must of necessity be limited. The latest Zeppelin creation, a monster in size, is 450 feet long, and 42 1/2 feet in diameter. The dimensions are such as to make all other balloons look like pigmies; even many ocean-going steamers are much smaller, and yet its passenger capacity is very small. On its 36-hour flight in May, 1909, the Zeppelin, carried only eight passengers. The speed, however, was quite respectable, 850 miles being covered in the 36 hours, a trifle over 23 miles an hour. The reserve buoyancy, that is the total lifting capacity aside from the weight of the airship and its equipment, is estimated at three tons. CHAPTER XXII. PROBLEMS OF AERIAL FLIGHT. In a lecture before the Royal Society of Arts, reported in Engineering, F. W. Lanchester took the position that practical flight was not the abstract question which some apparently considered it to be, but a problem in locomotive engineering. The flying machine was a locomotive appliance, designed not merely to lift a weight, but to transport it elsewhere, a fact which should be sufficiently obvious. Nevertheless one of the leading scientific men of the day advocated a type in which this, the main function of the flying machine, was overlooked. When the machine was considered as a method of transport, the vertical screw type, or helicopter, became at once ridiculous. It had, nevertheless, many advocates who had some vague and ill-defined notion of subsequent motion through the air after the weight was raised. Helicopter Type Useless. When efficiency of transport was demanded, the helicopter type was entirely out of court. Almost all of its advocates neglected the effect of the motion of the machine through the air on the efficiency of the vertical screws. They either assumed that the motion was so slow as not to matter, or that a patch of still air accompanied the machine in its flight. Only one form of this type had any possibility of success. In this there were two screws running on inclined axles--one on each side of the weight to be lifted. The action of such inclined screw was curious, and in a previous lecture he had pointed out that it was almost exactly the same as that of a bird's wing. In high-speed racing craft such inclined screws were of necessity often used, but it was at a sacrifice of their efficiency. In any case the efficiency of the inclined-screw helicopter could not compare with that of an aeroplane, and that type might be dismissed from consideration so soon as efficiency became the ruling factor of the design. Must Compete With Locomotive. To justify itself the aeroplane must compete, in some regard or other, with other locomotive appliances, performing one or more of the purposes of locomotion more efficiently than existing systems. It would be no use unless able to stem air currents, so that its velocity must be greater than that of the worst winds liable to be encountered. To illustrate the limitations imposed on the motion of an aeroplane by wind velocity, Mr. Lanchester gave the diagrams shown in Figs. 1 to 4. The circle in each case was, he said, described with a radius equal to the speed of the aeroplane in still air, from a center placed "down-wind" from the aeroplane by an amount equal to the velocity of the wind. Fig. 1 therefore represented the case in which the air was still, and in this case the aeroplane represented by _A_ had perfect liberty of movement in any direction In Fig. 2 the velocity of the wind was half that of the aeroplane, and the latter could still navigate in any direction, but its speed against the wind was only one-third of its speed with the wind. In Fig. 3 the velocity of the wind was equal to that of the aeroplane, and then motion against the wind was impossible; but it could move to any point of the circle, but not to any point lying to the left of the tangent _A_ _B_. Finally, when the wind had a greater speed than the aeroplane, as in Fig. 4, the machine could move only in directions limited by the tangents _A_ _C_ and _A_ _D_. Matter of Fuel Consumption. Taking the case in which the wind had a speed equal to half that of the aeroplane, Mr. Lanchester said that for a given journey out and home, down wind and back, the aeroplane would require 30 per cent more fuel than if the trip were made in still air; while if the journey was made at right angles to the direction of the wind the fuel needed would be 15 per cent more than in a calm. This 30 per cent extra was quite a heavy enough addition to the fuel; and to secure even this figure it was necessary that the aeroplane should have a speed of twice that of the maximum wind in which it was desired to operate the machine. Again, as stated in the last lecture, to insure the automatic stability of the machine it was necessary that the aeroplane speed should be largely in excess of that of the gusts of wind liable to be encountered. Eccentricities of the Wind. There was, Mr. Lanchester said, a loose connection between the average velocity of the wind and the maximum speed of the gusts. When the average speed of the wind was 40 miles per hour, that of the gusts might be equal or more. At one moment there might be a calm or the direction of the wind even reversed, followed, the next moment, by a violent gust. About the same minimum speed was desirable for security against gusts as was demanded by other considerations. Sixty miles an hour was the least figure desirable in an aeroplane, and this should be exceeded as much as possible. Actually, the Wright machine had a speed of 38 miles per hour, while Farman's Voisin machine flew at 45 miles per hour. Both machines were extremely sensitive to high winds, and the speaker, in spite of newspaper reports to the contrary, had never seen either flown in more than a gentle breeze. The damping out of the oscillations of the flight path, discussed in the last lecture, increased with the fourth power of the natural velocity of flight, and rapid damping formed the easiest, and sometimes the only, defense against dangerous oscillations. A machine just stable at 35 miles per hour would have reasonably rapid damping if its speed were increased to 60 miles per hour. Thinks Use Is Limited. It was, the lecturer proceeded, inconceivable that any very extended use should be made of the aeroplane unless the speed was much greater than that of the motor car. It might in special cases be of service, apart from this increase of speed, as in the exploration of countries destitute of roads, but it would have no general utility. With an automobile averaging 25 to 35 miles per hour, almost any part of Europe, Russia excepted, was attainable in a day's journey. A flying machine of but equal speed would have no advantages, but if the speed could be raised to 90 or 100 miles per hour, the whole continent of Europe would become a playground, every part being within a daylight flight of Berlin. Further, some marine craft now had speeds of 40 miles per hour, and efficiently to follow up and report movements of such vessels an aeroplane should travel at 60 miles per hour at least. Hence from all points of view appeared the imperative desirability of very high velocities of flight. The difficulties of achievement were, however, great. Weight of Lightest Motors. As shown in the first lecture of his course, the resistance to motion was nearly independent of the velocity, so that the total work done in transporting a given weight was nearly constant. Hence the question of fuel economy was not a bar to high velocities of flight, though should these become excessive, the body resistance might constitute a large proportion of the total. The horsepower required varied as the velocity, so the factor governing the maximum velocity of flight was the horsepower that could be developed on a given weight. At present the weight per horsepower of feather-weight motors appeared to range from 2 1/4 pounds up to 7 pounds per brake horsepower, some actual figures being as follows: Antoinette........ 5 lbs. Fiat.............. 3 lbs. Gnome....... Under 3 lbs. Metallurgic....... 8 lbs. Renault........... 7 lbs. Wright.............6 lbs. Automobile engines, on the other hand, commonly weighed 12 pounds to 13 pounds per brake horsepower. For short flights fuel economy was of less importance than a saving in the weight of the engine. For long flights, however, the case was different. Thus, if the gasolene consumption was 1/2 pound per horsepower hour, and the engine weighed 3 pounds per brake horsepower, the fuel needed for a six-hour flight would weigh as much as the engine, but for half an hour's flight its weight would be unimportant. Best Means of Propulsion. The best method of propulsion was by the screw, which acting in air was subject to much the same conditions as obtained in marine work. Its efficiency depended on its diameter and pitch and on its position, whether in front of or behind the body propelled. From this theory of dynamic support, Mr. Lanchester proceeded, the efficiency of each element of a screw propeller could be represented by curves such as were given in his first lecture before the society, and from these curves the over-all efficiency of any proposed propeller could be computed, by mere inspection, with a fair degree of accuracy. These curves showed that the tips of long-bladed propellers were inefficient, as was also the portion of the blade near the root. In actual marine practice the blade from boss to tip was commonly of such a length that the over-all efficiency was 95 per cent of that of the most efficient element of it. Advocates Propellers in Rear. From these curves the diameter and appropriate pitch of a screw could be calculated, and the number of revolutions was then fixed. Thus, for a speed of 80 feet per second the pitch might come out as 8 feet, in which case the revolutions would be 600 per minute, which might, however, be too low for the motor. It was then necessary either to gear down the propeller, as was done in the Wright machine, or, if it was decided to drive it direct, to sacrifice some of the efficiency of the propeller. An analogous case arose in the application of the steam turbine to the propulsion of cargo boats, a problem as yet unsolved. The propeller should always be aft, so that it could abstract energy from the wake current, and also so that its wash was clear of the body propelled. The best possible efficiency was about 70 per cent, and it was safe to rely upon 66 per cent. Benefits of Soaring Flight. There was, Mr. Lanchester proceeded, some possibility of the aeronaut reducing the power needed for transport by his adopting the principle of soaring flight, as exemplified by some birds. There were, he continued, two different modes of soaring flight. In the one the bird made use of the upward current of air often to be found in the neighborhood of steep vertical cliffs. These cliffs deflected the air upward long before it actually reached the cliff, a whole region below being thus the seat of an upward current. Darwin has noted that the condor was only to be found in the neighborhood of such cliffs. Along the south coast also the gulls made frequent use of the up currents due to the nearly perpendicular chalk cliffs along the shore. In the tropics up currents were also caused by temperature differences. Cumulus clouds, moreover, were nearly always the terminations of such up currents of heated air, which, on cooling by expansion in the upper regions, deposited their moisture as fog. These clouds might, perhaps, prove useful in the future in showing the aeronaut where up currents were to be found. Another mode of soaring flight was that adopted by the albatross, which took advantage of the fact that the air moved in pulsations, into which the bird fitted itself, being thus able to extract energy from the wind. Whether it would be possible for the aeronaut to employ a similar method must be left to the future to decide. Main Difficulties in Aviation. In practical flight difficulties arose in starting and in alighting. There was a lower limit to the speed at which the machine was stable, and it was inadvisable to leave the ground till this limit was attained. Similarly, in alighting it was inexpedient to reduce the speed below the limit of stability. This fact constituted a difficulty in the adoption of high speeds, since the length of run needed increased in proportion to the square of the velocity. This drawback could, however, be surmounted by forming starting and alighting grounds of ample size. He thought it quite likely in the future that such grounds would be considered as essential to the flying machine as a seaport was to an ocean-going steamer or as a road was to the automobile. Requisites of Flying Machine. Flying machines were commonly divided into monoplanes and biplanes, according as they had one or two supporting surfaces. The distinction was not, however, fundamental. To get the requisite strength some form of girder framework was necessary, and it was a mere question of convenience whether the supporting surface was arranged along both the top and the bottom of this girder, or along the bottom only. The framework adopted universally was of wood braced by ties of pianoforte wire, an arrangement giving the stiffness desired with the least possible weight. Some kind of chassis was also necessary. CHAPTER XXIII. AMATEURS MAY USE WRIGHT PATENTS. Owing to the fact that the Wright brothers have enjoined a number of professional aviators from using their system of control, amateurs have been slow to adopt it. They recognize its merits, and would like to use the system, but have been apprehensive that it might involve them in litigation. There is no danger of this, as will be seen by the following statement made by the Wrights: What Wright Brothers Say. "Any amateur, any professional who is not exhibiting for money, is at liberty to use our patented devices. We shall be glad to have them do so, and there will be no interference on our part, by legal action, or otherwise. The only men we proceed against are those who, without our permission, without even asking our consent, coolly appropriate the results of our labors and use them for the purpose of making money. Curtiss, Delagrange, Voisin, and all the rest of them who have used our devices have done so in money-making exhibitions. So long as there is any money to be made by the use of the products of our brains, we propose to have it ourselves. It is the only way in which we can get any return for the years of patient work we have given to the problem of aviation. On the other hand, any man who wants to use these devices for the purpose of pleasure, or the advancement of science, is welcome to do so, without money and without price. This is fair enough, is it not?" Basis of the Wright Patents. In a flying machine a normally flat aeroplane having lateral marginal portions capable of movement to different positions above or below the normal plane of the body of the aeroplane, such movement being about an axis transverse to the line of flight, whereby said lateral marginal portions may be moved to different angles relatively to the normal plane of the body of the aeroplane, so as to present to the atmosphere different angles of incidence, and means for so moving said lateral marginal portions, substantially as described. Application of vertical struts near the ends having flexible joints. Means for simultaneously imparting such movement to said lateral portions to different angles relatively to each other. Refers to the movement of the lateral portions on the same side to the same angle. Means for simultaneously moving vertical rudder so as to present to the wind that side thereof nearest the side of the aeroplane having the smallest angle of incidence. Lateral stability is obtained by warping the end wings by moving the lever at the right hand of the operator, connection being made by wires from the lever to the wing tips. The rudder may also be curved or warped in similar manner by lever action. Wrights Obtain an Injunction. In January, 1910, Judge Hazel, of the United States Circuit Court, granted a preliminary injunction restraining the Herring-Curtiss Co., and Glenn H. Curtiss, from manufacturing, selling, or using for exhibition purposes the machine known as the Curtiss aeroplane. The injunction was obtained on the ground that the Curtiss machine is an infringement upon the Wright patents in the matter of wing warping and rudder control. It is not the purpose of the authors to discuss the subject pro or con. Such discussion would have no proper place in a volume of this kind. It is enough to say that Curtiss stoutly insists that his machine is not an infringement of the Wright patents, although Judge Hazel evidently thinks differently. What the Judge Said. In granting the preliminary injunction the judge said: "Defendants claim generally that the difference in construction of their apparatus causes the equilibrium or lateral balance to be maintained and its aerial movement secured upon an entirely different principle from that of complainant; the defendants' aeroplanes are curved, firmly attached to the stanchions and hence are incapable of twisting or turning in any direction; that the supplementary planes or so-called rudders are secured to the forward stanchion at the extreme lateral ends of the planes and are adjusted midway between the upper and lower planes with the margins extending beyond the edges; that in moving the supplementary planes equal and uniform angles of incidence are presented as distinguished from fluctuating angles of incidence. Such claimed functional effects, however, are strongly contradicted by the expert witness for complainant. Similar to Plan of Wrights. "Upon this contention it is sufficient to say that the affidavits for the complainant so clearly define the principle of operation of the flying machines in question that I am reasonably satisfied that there is a variableness of the angle of incidence in the machine of defendants which is produced when a supplementary plane on one side is tilted or raised and the other stimultaneously tilted or lowered. I am also satisfied that the rear rudder is turned by the operator to the side having the least angle of incidence and that such turning is done at the time the supplementary planes are raised or depressed to prevent tilting or upsetting the machine. On the papers presented I incline to the view, as already indicated, that the claims of the patent in suit should be broadly construed; and when given such construction, the elements of the Wright machine are found in defendants' machine performing the same functional result. There are dissimilarities in the defendants' structure--changes of form and strengthening of parts--which may be improvements, but such dissimilarities seem to me to have no bearing upon the means adopted to preserve the equilibrium, which means are the equivalent of the claims in suit and attain an identical result. Variance From Patent Immaterial. "Defendants further contend that the curved or arched surfaces of the Wright aeroplanes in commercial use are departures from the patent, which describes 'substantially flat surfaces,' and that such a construction would be wholly impracticable. The drawing, Fig. 3, however, attached to the specification, shows a curved line inward of the aeroplane with straight lateral edges, and considering such drawing with the terminology of the specification, the slight arching of the surface is not thought a material departure; at any rate, the patent in issue does not belong to the class of patents which requires narrowing to the details of construction." "June Bug" First Infringement. Referring to the matter of priority, the judge said: "Indeed, no one interfered with the rights of the patentees by constructing machines similar to theirs until in July, 1908, when Curtiss exhibited a flying machine which he called the 'June Bug.' He was immediately notified by the patentees that such machine with its movable surfaces at the tips of wings infringed the patent in suit, and he replied that he did not intend to publicly exhibit the machine for profit, but merely was engaged in exhibiting it for scientific purposes as a member of the Aerial Experiment Association. To this the patentees did not object. Subsequently, however, the machine, with supplementary planes placed midway between the upper and lower aeroplanes, was publicly exhibited by the defendant corporation and used by Curtiss in aerial flights for prizes and emoluments. It further appears that the defendants now threaten to continue such use for gain and profit, and to engage in the manufacture and sale of such infringing machines, thereby becoming an active rival of complainant in the business of constructing flying machines embodying the claims in suit, but such use of the infringing machines it is the duty of this court, on the papers presented, to enjoin. "The requirements in patent causes for the issuance of an injunction pendente lite--the validity of the patent, general acquiescence by the public and infringement by the defendants--are so reasonably clear that I believe if not probable the complainant may succeed at final hearing, and therefore, status quo should be preserved and a preliminary injunction granted. "So ordered." Points Claimed By Curtiss. That the Herring-Curtiss Co. will appeal is a certainty. Mr. Emerson R. Newell, counsel for the company, states its case as follows: "The Curtiss machine has two main supporting surfaces, both of which are curved * * * and are absolutely rigid at all times and cannot be moved, warped or distorted in any manner. The front horizontal rudder is used for the steering up or down, and the rear vertical rudder is used only for steering to the right or left, in the same manner as a boat is steered by its rudder. The machine is provided at the rear with a fixed horizontal surface, which is not present in the machine of the patent, and which has a distinct advantage in the operation of defendants' machine, as will be hereafter discussed. Does Not Warp Main Surface. "Defendants' machine does not use the warping of the main supporting surfaces in restoring the lateral equilibrium, but has two comparatively small pivoted balancing surfaces or rudders. When one end of the machine is tipped up or down from the normal, these planes may be thrown in opposite directions by the operator, and so steer each end of the machine up or down to its normal level, at which time tension upon them is released and they are moved back by the pressure of the wind to their normal position. Rudder Used Only For Steering. "When defendants' balancing surfaces are moved they present equal angles of incidence to the normal rush of air and equal resistances, at each side of the machine, and there is therefore no tendency to turn around a vertical axis as is the case of the machine of the patent, consequently no reason or necessity for turning the vertical rear rudder in defendants' machine to counteract any such turning tendency. At any rate, whatever may be the theories in regard to this matter, the fact is that the operator of defendants' machine does not at any time turn his vertical rudder to counteract any turning tendency clue to the side balancing surfaces, but only uses it to steer the machine the same as a boat is steered." Aero Club Recognizes Wrights. The Aero Club of America has officially recognized the Wright patents. This course was taken following a conference held April 9th, 1910, participated in by William Wright and Andrew Freedman, representing the Wright Co., and the Aero Club's committee, of Philip T. Dodge, W. W. Miller, L. L. Gillespie, Wm. H. Page and Cortlandt F. Bishop. At this meeting arrangements were made by which the Aero Club recognizes the Wright patents and will not give its section to any open meet where the promoters thereof have not secured a license from the Wright Company. The substance of the agreement was that the Aero Club of America recognizes the rights of the owners of the Wright patents under the decisions of the Federal courts and refuses to countenance the infringement of those patents as long as these decisions remain in force. In the meantime, in order to encourage aviation, both at home and abroad, and in order to permit foreign aviators to take part in aviation contests in this country it was agreed that the Aero Club of America, as the American representative of the International Aeronautic Federation, should approve only such public contests as may be licensed by the Wright Company and that the Wright Company, on the other hand, should encourage the holding of open meets or contests where ever approved as aforesaid by the Aero Club of America by granting licenses to promoters who make satisfactory arrangements with the company for its compensation for the use of its patents. At such licensed meet any machine of any make may participate freely without securing any further license or permit. The details and terms of all meets will be arranged by the committee having in charge the interests of both organizations. CHAPTER XXIV. HINTS ON PROPELLER CONSTRUCTION. Every professional aviator has his own ideas as to the design of the propeller, one of the most important features of flying-machine construction. While in many instances the propeller, at a casual glance, may appear to be identical, close inspection will develop the fact that in nearly every case some individual idea of the designer has been incorporated. Thus, two propellers of the two-bladed variety, while of the same general size as to length and width of blade, will vary greatly as to pitch and "twist" or curvature. What the Designers Seek. Every designer is seeking for the same result--the securing of the greatest possible thrust, or air displacement, with the least possible energy. The angles of any screw propeller blade having a uniform or true pitch change gradually for every increased diameter. In order to give a reasonably clear explanation, it will be well to review in a primary way some of the definitions or terms used in connection with and applied to screw propellers. Terms in General Use. Pitch.--The term "pitch," as applied to a screw propeller, is the theoretical distance through which it would travel without slip in one revolution, and as applied to a propeller blade it is the angle at which the blades are set so as to enable them to travel in a spiral path through a fixed distance theoretically without slip in one revolution. Pitch speed.--The term "pitch speed" of a screw propeller is the speed in feet multiplied by the number of revolutions it is caused to make in one minute of time. If a screw propeller is revolved 600 times per minute, and if its pitch is 7 ft., then the pitch speed of such a propeller would be 7x600 revolutions, or 4200 ft. per minute. Uniform pitch.--A true pitch screw propeller is one having its blades formed in such a manner as to enable all of its useful portions, from the portion nearest the hub to its outer portion, to travel at a uniform pitch speed. Or, in other words, the pitch is uniform when the projected area of the blade is parallel along its full length and at the same time representing a true sector of a circle. All screw propellers having a pitch equal to their diameters have the same angle for their blades at their largest diameter. When Pitch Is Not Uniform. A screw propeller not having a uniform pitch, but having the same angle for all portions of its blades, or some arbitrary angle not a true pitch, is distinguished from one having a true pitch in the variation of the pitch speeds that the various portions of its blades are forced to travel through while traveling at its maximum pitch speed. On this subject Mr. R. W. Jamieson says in Aeronautics: "Take for example an 8-foot screw propeller having an 8-foot pitch at its largest diameter. If the angle is the same throughout its entire blade length, then all the porions of its blades approaching the hub from its outer portion would have a gradually decreasing pitch. The 2-foot portion would have a 2-foot pitch; the 3-foot portion a 3-foot pitch, and so on to the 8-foot portion which would have an 8-foot pitch. When this form of propeller is caused to revolve, say 500 r.p.m., the 8-foot portion would have a calculated pitch speed of 8 feet by 500 revolutions, or 4,000 feet per min.; while the 2-foot portion would have a calculated pitch speed of 500 revolutions by 2 feet, or 1,000 feet per minute. Effect of Non-Uniformity. "Now, as all of the portions of this type of screw propeller must travel at some pitch speed, which must have for its maximum a pitch speed in feet below the calculated pitch speed of the largest diameter, it follows that some portions of its blades would perform useful work while the action of the other portions would be negative--resisting the forward motion of the portions having a greater pitch speed. The portions having a pitch speed below that at which the screw is traveling cease to perform useful work after their pitch speed has been exceeded by the portions having a larger diameter and a greater pitch speed. "We might compare the larger and smaller diameter portions of this form of screw propeller, to two power-driven vessels connected with a line, one capable of traveling 20 miles per hour, the other 10 miles per hour. It can be readily understood that the boat capable of traveling 10 miles per hour would have no useful effect to help the one traveling 20 miles per hour, as its action would be such as to impose a dead load upon the latter's progress." The term "slip," as applied to a screw propeller, is the distance between its calculated pitch speed and the actual distance it travels through under load, depending upon the efficiency and proportion of its blades and the amount of load it has to carry. The action of a screw propeller while performing useful work might be compared to a nut traveling on a threaded bolt; little resistance is offered to its forward motion while it spins freely without load, but give it a load to carry; then it will take more power to keep up its speed; if too great a load is applied the thread will strip, and so it is with a screw propeller gliding spirally on the air. A propeller traveling without load on to new air might be compared to the nut traveling freely on the bolt. It would consume but little power and it would travel at nearly its calculated pitch speed, but give it work to do and then it will take power to drive it. There is a reaction caused from the propeller projecting air backward when it slips, which, together with the supporting effect of the blades, combine to produce useful work or pull on the object to be carried. A screw propeller working under load approaches more closely to its maximum efficiency as it carries its load with a minimum amount of slip, or nearing its calculated pitch speed. Why Blades Are Curved. It has been pointed out by experiment that certain forms of curved surfaces as applied to aeroplanes will lift more per horse power, per unit of square foot, while on the other hand it has been shown that a flat surface will lift more per horse power, but requires more area of surface to do it. As a true pitch screw propeller is virtually a rotating aeroplane, a curved surface may be advantageously employed when the limit of size prevents using large plane surfaces for the blades. Care should be exercised in keeping the chord of any curve to be used for the blades at the proper pitch angle, and in all cases propeller blades should be made rigid so as to preserve the true angle and not be distorted by centrifugal force or from any other cause, as flexibility will seriously affect their pitch speed and otherwise affect their efficiency. How to Determine Angle. To find the angle for the proper pitch at any point in the diameter of a propeller, determine the circumference by multiplying the diameter by 3.1416, which represent by drawing a line to scale in feet. At the end of this line draw another line to represent the desired pitch in feet. Then draw a line from the point representing the desired pitch in feet to the beginning of the circumference line. For example: If the propeller to be laid out is 7 feet in diameter, and is to have a 7-foot pitch, the circumference will be 21.99 feet. Draw a diagram representing the circumference line and pitch in feet. If this diagram is wrapped around a cylinder the angle line will represent a true thread 7 feet in diameter and 7 feet long, and the angle of the thread will be 17 3/4 degrees. Relation of Diameter to Circumference. Since the areas of circles decrease as the diameter lessens, it follows that if a propeller is to travel at a uniform pitch speed, the volume of its blade displacement should decrease as its diameter becomes less, so as to occupy a corresponding relation to the circumferences of larger diameters, and at the same time the projected area of the blade must be parallel along its full length and should represent a true sector of a circle. Let us suppose a 7-foot circle to be divided into 20 sectors, one of which represents a propeller blade. If the pitch is to be 7 feet, then the greatest depth of the angle would be 1/20 part of the pitch, or 4 2/10 inch. If the line representing the greatest depth of the angle is kept the same width as it approaches the hub, the pitch will be uniform. If the blade is set at an angle so its projected area is 1/20 part of the pitch, and if it is moved through 20 divisions for one revolution, it would have a travel of 7 feet. CHAPTER XXV. NEW MOTORS AND DEVICES. Since the first edition of this book was printed, early in 1910, there has been a remarkable advance in the construction of aeroplane motors, which has resulted in a wonderful decrease in the amount of surface area from that formerly required. Marked gain in lightness and speed of the motor has enabled aviators to get along, in some instances, with one-quarter of the plane supporting area previously used. The first Wright biplane, propelled by a motor of 25 h.p., productive of a fair average speed of 30 miles an hour, had a plane surface of 538 square feet. Now, by using a specially designed motor of 65 h. p., capable of developing a speed of from 70 to 80 miles an hour, the Wrights are enabled to successfully navigate a machine the plane area of which is about 130 square feet. This apparatus is intended to carry only one person (the operator). At Belmont Park, N. Y., the Wrights demonstrated that the small-surfaced biplane is much faster, easier to manage in the hands of a skilled manipulator, and a better altitude climber than the large and cumbersome machines with 538 square feet of surface heretofore used by them. In this may be found a practical illustration of the principle that increased speed permits of a reduction in plane area in mathematical ratio to the gain in speed. The faster any object can be made to move through the air, the less will be the supporting surface required to sustain a given weight. But, there is a limit beyond which the plane surface cannot be reduced with safety. Regard must always be had to the securing of an ample sustaining surface so that in case of motor stoppage there will be sufficient buoyancy to enable the operator to descend safely. The baby Wright used at the Belmont Park (N. Y.) aviation meet in the fall of 1910, had a plane length of 19 feet 6 inches, and an extreme breadth of 21 feet 6 inches, with a total surface area of 146 square feet. It was equipped with a new Wright 8-cylinder motor of 60 h. p., and two Wright propellers of 8 feet 6 inches diameter and 500 r. p. m. It was easily the fastest machine at the meet. After the tests, Wilbur Wright said: "It is our intention to put together a machine with specially designed propellers, specially designed gears and a motor which will give us 65 horsepower at least. We will then be able, after some experimental work we are doing now, to send forth a machine that will make a new speed record." In the new Wright machines the front elevating planes for up-and-down control have been eliminated, and the movements of the apparatus are now regulated solely by the rear, or "tail" control. A Powerful Light Motor. Another successful American aviation motor is the aeromotor, manufactured by the Detroit Aeronautic Construction. Aeromotors are made in four models as follows: Model 1.--4-cylinder, 30-40 h. p., weight 200 pounds. Model 2.--4-cylinder, (larger stroke and bore) 40-50 h. p., weight 225 pounds. Model 3.--6-cylinder. 50-60 h. p., weight 210 pounds. Model 4.--6-cylinder, 60-75 h. p., weight 275 pounds. This motor is of the 4-cycle, vertical, water-cooled type. Roberts Aviation Motor. One of the successful aviation motors of American make, is that produced by the Roberts Motor Co., of Sandusky, Ohio. It is designed by E. W. Roberts, M. E., who was formerly chief assistant and designer for Sir Hiram Maxim, when the latter was making his celebrated aeronautical experiments in England in 1894-95. This motor is made in both the 4- and 6-cylinder forms. The 4-cylinder motor weighs complete with Bosch magneto and carbureter 165 pounds, and will develop 40 actual brake h. p. at 1,000 r. p. m., 46 h. p. at 1,200 and 52 h. p. at 1,400. The 6-cylinder weighs 220 pounds and will develop 60 actual brake h. p. at 1,000 r. p. m., 69 h. p. at 1,200 and 78 h. p. at 1,500. Extreme lightness has been secured by doing away with all superfluous parts, rather than by a shaving down of materials to a dangerous thinness. For example, there is neither an intake or exhaust manifold on the motor. The distributing valve forms a part of the crankcase as does the water intake, and the gear pump. Magnalium takes the place of aluminum in the crankcase, because it is not only lighter but stronger and can be cast very thin. The crankshaft is 2 1/2-inch diameter with a 2 1/4-inch hole, and while it would be strong enough in ordinary 40 per cent carbon steel it is made of steel twice the strength of that customarily employed. Similar care has been exercised on other parts and the result is a motor weighing 4 pounds per h. p. The Rinek Motor. The Rinek aviation motor, constructed by the Rinek Aero Mfg. Co., of Easton, Pa., is another that is meeting with favor among aviators. Type B-8 is an 8-cylinder motor, the cylinders being set at right angles, on a V-shaped crank case. It is water cooled, develops 50-60 h. p., the minimum at 1,220 r. p. m., and weighs 280 pounds with all accessories. Type B-4, a 4-cylinder motor, develops 30 h. p. at 1,800 r. p. m., and weighs 130 pounds complete. The cylinders in both motors are made of cast iron with copper water jackets. The Overhead Camshaft Boulevard. The overhead camshaft Boulevard is still another form of aviation motor which has been favorably received. This is the product of the Boulevard Engine Co., of St. Louis. It is made with 4 and 8 cylinders. The former develops 30-35 h. p. at 1,200 r. p. m., and weighs 130 pounds. The 8-cylinder motor gives 60-70 h. p. at 1,200 r. p. m., and weighs 200 pounds. Simplicity of construction is the main feature of this motor, especially in the manipulation of the valves. CHAPTER XXVI. MONOPLANES, TRIPLANES, MULTIPLANES. Until recently, American aviators had not given serious attention to any form of flying machines aside from biplanes. Of the twenty-one monoplanes competing at the International meet at Belmont Park, N. Y., in November, 1910, only three makes were handled by Americans. Moissant and Drexel navigated Bleriot machines, Harkness an Antoinette, and Glenn Curtiss a single decker of his own construction. On the other hand the various foreign aviators who took part in the meet unhesitatingly gave preference to monoplanes. Whatever may have been the cause of this seeming prejudice against the monoplane on the part of American air sailors, it is slowly being overcome. When a man like Curtiss, who has attained great success with biplanes, gives serious attention to the monoplane form of construction and goes so far as to build and successfully operate a single surface machine, it may be taken for granted that the monoplane is a fixture in this country. Dimensions of Monoplanes. The makes, dimensions and equipment of the various monoplanes used at Belmont Park are as follows: Bleriot--(Moissant, operator)--plane length 23 feet, extreme breadth 28 feet, surface area 160 square feet, 7-cylinder, 50 h. p. Gnome engine, Chauviere propeller, 7 feet 6 inches diameter, 1,200 r. p. m. Bleriot--(Drexel, operator)--exactly the same as Moissant's machine. Antoinette--(Harkness, operator)--plane length 42 feet, extreme breadth 46 feet, surface area 377 square feet, Emerson 6-cylinder, 50 h. p. motor, Antoinette propeller, 7 feet 6 inches diameter, 1,200 r. p. m. Curtiss--(Glenn H. Curtiss, operator)--plane length 25 feet, extreme breadth 26 feet, surface area 130 square feet, Curtiss 8-cylinder, 60 h. p. motor, Paragon propeller, 7 feet in diameter, 1,200 r. p. m. With one exception Curtiss had the smallest machine of any of those entering into competition. The smallest was La Demoiselle, made by Santos-Dumont, the proportions of which were: plane length 20 feet, extreme breadth 18 feet, surface area 100 square feet, Clement-Bayard 2-cylinder, 30 h. p. motor, Chauviere propeller, 6 feet 6 inches in diameter, 1,100 r. p. m. Winnings Made with Monoplanes. Operators of monoplanes won a fair share of the cash prizes. They won $30,283 out of a total of $63,250, to say nothing about Grahame-White's winnings. The latter won $13,600, but part of his winning flights were made in a Bleriot monoplane, and part in a Farman machine. Aside from Grahame-White the winnings were divided as follows: Moissant (Bleriot) $13,350; Latham (Antoinette) $8,183; Aubrun (Bleriot) $2,400; De Lesseps (Bleriot) $2,300; Drexel (Bleriot) $1,700; Radley (Bleriot) $1,300; Simon (Bleriot) $750; Andemars (Clement-Bayard) $100; Barrier (Bleriot) $100. Out of a total of $30,283, operators of Bleriot machines won $21,900, again omitting Grahame-White's share. If the winnings with monoplane and biplane could be divided so as to show the amount won with each type of machine the credit side of the Bleriot account would be materially enlarged. The Most Popular Monoplanes. While the number of successful monoplanes is increasing rapidly, and there is some feature of advantage in nearly all the new makes, interest centers chiefly in the Santos-Dumont, Antoinette and Bleriot machines. This is because more has been accomplished with them than with any of the others, possibly because they have had greater opportunities. For the guidance of those who may wish to build a machine of the monoplane type after the Santos-Dumont or Bleriot models, the following details will be found useful. Santos-Dumont--The latest production of this maker is called the "No. 20 Baby." It is of 18 feet spread, and 20 feet over all in depth. It stands 4 feet 2 inches in height, not counting the propeller. When this latter is in a vertical position the extreme height of the machine is 7 feet 5 inches. It is strictly a one-man apparatus. The total surface area is 115 square feet. The total weight of the monoplane with engine and propeller is 352 pounds. Santos-Dumont weighs 110 pounds, so the entire weight carried while in flight is 462 pounds, or about 3.6 pounds per square foot of surface. Bamboo is used in the construction of the body frame, and also for the frame of the tail. The body frame consists of three bamboo poles about 2 inches in diameter at the forward end and tapering to about 1 inch at the rear. These poles are jointed with brass sockets near the rear of the main plane so they may be taken apart easily for convenience in housing or transportation. The main plane is built upon four transverse spars of ash, set at a slight dihedral angle, two being placed on each side of the central bamboo. These spars are about 2 inches wide by 1 1/8-inch deep for a few feet each side of the center of the machine, and from there taper down to an inch in depth at the center bamboo, and at their outer ends, but the width remains the same throughout their entire length. The planes are double surfaced with silk and laced above and below the bamboo ribs which run fore and aft under the main spars and terminate in a forked clip through which a wire is strung for lacing on the silk. The tail consists of a horizontal and vertical surface placed on a universal joint about 10 feet back of the rear edge of the main plane. Both of these surfaces are flat and consist of a silk covering stretched upon bamboo ribs. The horizontal surface is 6 feet 5 inches across, and 4 feet 9 inches from front to back. The vertical surface is of the same width (6 feet 5 inches) but is only 3 feet 7 inches from front to back. All the details of construction are shown in the accompanying illustration. Power is furnished by a very light (110 pounds) Darracq motor, of the double-opposed-cylinder type. It has a bore of 4.118 inches, and stroke of 4.724 inches, runs at 1,800 r. p. m., and with a 6 1/2-foot propeller develops a thrust of 242 1/2 pounds when the monoplane is held steady. Bleriot--No. XI, the latest of the Bleriot productions, and the greatest record maker of the lot, is 28 feet in spread of main plane, and depth of 6 feet in largest part. This would give a main surface of 168 square feet, but as the ends of the plane are sharply tapered from the rear, the actual surface is reduced to 150 square feet. Projecting from the main frame is an elongated tail (shown in the illustration) which carries the horizontal and vertical rudders. The former is made in three sections. The center piece is 6 feet 1 inch in spread, and 2 feet 10 inches in depth, containing 17 square feet of surface. The end sections, which are made movable for warping purposes, are each 2 feet 10 inches square, the combined surface area in the entire horizontal rudder being 33 square feet. The vertical rudder contains 4 1/2 square feet of surface, making the entire supporting area 187 1/2 square feet. From the outer end of the propeller shaft in front to the extreme rear edge of the vertical rudder, the machine is 25 feet deep. Deducting the 6-foot depth of the main plane leaves 19 feet as the length of the rudder beam and rudders. The motor equipment consists of a 3-cylinder, air-cooled engine of about 30 h. p. placed at the front end of the body frame, and carrying on its crankshaft a two-bladed propeller 6 feet 8 inches in diameter. The engine speed is about 1,250 r. p. m. at which the propeller develops a thrust of over 200 pounds. The Bleriot XI complete weighs 484 pounds, and with operator and fuel supply ready for a 25- or 30-mile flight, 715 pounds. One peculiarity of the Bleriot construction is that, while the ribs of the main plane are curved, there is no preliminary bending of the pieces as in other forms of construction. Bleriot has his rib pieces cut a little longer than required and, by springing them into place, secures the necessary curvature. A good view of the Bleriot plane framework is given on page 63. Combined Triplane and Biplane. At Norwich, Conn., the Stebbins-Geynet Co., after several years of experiment, has begun the manufacture of a combination triplane and biplane machine. The center plane, which is located about midway between the upper and lower surfaces, is made removable. The change from triplane to biplane, or vice versa, may be readily made in a few minutes. The constructors claim for this type of air craft a large supporting surface area with the minimum of dimensions in planes. Although this machine has only 24-foot spread and is only 26 feet over all, its total amount of supporting area is 400 square feet; weight, 600 pounds in flying order, and lifting capacity approximately 700 pounds more. The frame is made entirely of a selected grade of Oregon spruce, finished down to a smooth surface and varnished. All struts are fish-shaped and set in aluminum sockets, which are bolted to top and lower beams with special strong bolts of small diameter. The middle plane is set inside the six uprights and held in place by aluminum castings. A flexible twisted seven-strand wire cable and Stebbins-Geynet turnbuckles are used for trussing. The top plane is in three sections, laced together. It has a 24-foot spread and is 7 feet in depth. The middle plane is in two sections each of 7 1/2 feet spread and 6 feet in depth. The center ends of the middle plane sections do not come within 5 feet of joining, this open space being left for the engine. The bottom plane is of 16 feet spread and 5 feet in depth. It will thus be seen that the planes overhang one another in depth, the bottom one being the smallest in this respect. The planes are set at an angle of 9 degrees, and there is a clear space of 3 1/2 feet between each, making the total distance from the bottom to the top plane a trifle over 7 feet. The total supporting surface in the main planes is 350 square feet. By arranging the three plane surfaces at an angle as described and varying their size, the greatest amount of lifting area is secured above the center of gravity, and the greatest weight carried below. The ribs are made of laminated spruce, finished down to 1/2x3/4-inch cross section dimensions, with a curvature of about 1 in 20, and fastened to the beams with special aluminum castings. Number 2 Naiad aeroplane cloth is used in covering the planes, with pockets sewn in for the ribs. Two combination elevating rudders are set up well in front, each having 18 square feet of supporting area. These rudders are arranged to work in unison, independently, or in opposite directions. In the Model B machine, there are also two small rear elevating rudders, which work in unison with the front rudders. One vertical rudder of 10 square feet is suspended in the rear of a small stationary horizontal plane in Model A, while the vertical rudder on Model B is only 6 square feet in size. The elevating rudders are arranged so as to act as stabilizing planes when the machine is in flight. The wing tips are held in place with a special two-piece casting which forms a hinge, and makes a quick detachable joint. Wing tips are also used in balancing. Model A is equipped with a Cameron 25-30 h. p., 4-cylinder, air-cooled motor. On Model B a Holmes rotary 7-cylinder motor of 4x4-inch bore and stroke is used. Positive control is secured by use of the Stebbins-Geynet "auto-control" system. A pull or push movement operates the elevating rudders, while the balancing is done by means of side movements or slight turns. The rear vertical rudder is manipulated by means of a foot lever. New Cody Biplane. Among the comparatively new biplanes is one constructed by Willard F. Cody, of London, Eng., the principal distinctive feature of which is an automatic control which works independently of the hand levers. For the other control a long lever carrying a steering wheel furnishes all the necessary control movements, there being no footwork at all. The lever is universally jointed and when moved fore and aft operates the two ailerons as if they were one; when the shaft is rotated it moves the tail as a whole. The horizontal tail component is immovable. When the lever is moved from side to side it works not only the ailerons and the independent elevators, but also through a peculiar arrangement, the vertical rear rudder as well. The spread of the planes is 46 feet 6 inches and the width 6 feet 6 inches. The ailerons jut out 1 foot 6 inches on each side of the machine and are 13 feet 6 inches long. The cross-shaped tail is supported by an outrigger composed of two long bamboos and of this the vertical plane is 9 feet by 4 feet, while the horizontal plane is 8 feet by 4 feet. The over-all length of the machine is 36 feet. The lifting surface is 857 square feet. It will weigh, with a pilot, 1,450 pounds. The distance between the main planes is 8 feet 6 inches, which is a rather notable feature in this flyer. The propeller has a diameter of 11 feet and 2 inches with a 13-foot 6-inch pitch; it is driven at 560 revolutions by a chain, and the gear reduction between the chain and propeller shaft is two to one. The machine from elevator to tail plane bristles in original points. The hump in the ribs has been cut away entirely, so that although the plane is double surfaced, the surfaces are closest together at a point which approximates the center of pressure. The plane is practically of two stream-line forms, of which one is the continuation of the other. This construction, claims the inventor, will give increased lift, and decreased head resistance. The trials substantiate this, as the angle of incidence in flying is only about one in twenty-six. The ribs in the main planes are made of strips of silver spruce one-half by one-half inch, while those in the ailerons are solid and one-fourth inch thick. In the main planes the fabric is held down with thin wooden fillets. Cody's planes are noted for their neatness, rigidity and smoothness. Pegamoid fabric is used throughout. Pressey Automatic Control. Another ingenious system of automatic control has been perfected by Dr. J. B. Pressey, of Newport News, Va. The aeroplane is equipped with a manually operated, vertical rudder, (3), at the stern, and a horizontal, manually operated, front control, (4), in front. At the ends of the main plane, and about midway between the upper and lower sections thereof, there are supplemental planes, (5). In connection with these supplemental planes (5), there is employed a gravity influenced weight, the aviator in his seat, for holding them in a horizontal, or substantially horizontal, position when the main plane is traveling on an even keel; and for causing them to tip when the main plane dips laterally, to port or starboard, the planes (5) having a lifting effect upon the depressed end of the main plane, and a depressing effect upon the lifted end of the main plane, so as to correct such lateral dip of the main plane, and restore it to an even keel. To the forward, upper edge of planes (5) connection is made by means of rod (13) to one arm of a bellcrank lever, (14) the latter being pivotally mounted upon a fore and aft pin (15), supported from the main plane; and the other arms of the port and starboard bellcrank levers (16), are connected by rod (17), which has an eye (18), for receiving the segmental rod (19), secured to and projecting from cross bar on seat supporting yoke (7). When, therefore, the main plane tips downwardly on the starboard side, the rod (17) will be moved bodily to starboard, and the starboard balancing plane (5) will be inclined so as to raise its forward edge and depress its rear edge, while, at the same time, the port balancing plane (5), will be inclined so as to depress its forward edge, and raise its rear edge, thereby causing the starboard balancing plane to exert a lifting effect, and the port balancing plane to exert a depressing effect upon the main plane, with the result of restoring the main plane to an even keel, at which time the balancing planes (5), will have resumed their normal, horizontal position. When the main plane dips downwardly on the port side, a reverse action takes place, with the like result of restoring the main plane to an even keel. In order to correct forward and aft dip of the main plane, fore and aft balancing planes (20) and (23) are provided. These planes are carried by transverse rock shafts, which may be pivotally mounted in any suitable way, upon structures carried by main plane. In the present instance, the forward balancing plane is pivotally mounted in extensions (21) of the frame (22) which carries the forward, manually operated, horizontal ascending and descending plane It is absolutely necessary, in making a turn with an aeroplane, if that turn is to be made in safety, that the main plane shall be inclined, or "banked," to a degree proportional to the radius of the curve and to the speed of the aeroplane. Each different curve, at the same speed, demands a different inclination, as is also demanded by each variation in speed in rounding like curves. This invention gives the desired result with absolute certainty. The Sellers' Multiplane. Another innovation is a multiplane, or four-surfaced machine, built and operated by M. B. Sellers, formerly of Grahn, Ky., but now located at Norwood, Ga. Aside from the use of four sustaining surfaces, the novelty in the Sellers machine lies in the fact that it is operated successfully with an 8 h. p. motor, which is the smallest yet used in actual flight. In describing his work, Mr. Sellers says his purpose has been to develop the efficiency of the surfaces to a point where flight may be obtained with the minimum of power and, judging by the results accomplished, he has succeeded. In a letter written to the authors of this book, Mr. Sellers says: "I dislike having my machine called a quadruplane, because the number of planes is immaterial; the distinctive feature being the arrangement of the planes in steps; a better name would be step aeroplane, or step plane. "The machine as patented, comprises two or more planes arranged in step form, the highest being in front. The machine I am now using has four planes 3 ft. x 18 ft.; total about 200 square feet; camber (arch) 1 in 16. "The vertical keel is for lateral stability; the rudder for direction. This is the first machine (so far as I know) to have a combination of wheels and runners or skids (Oct. 1908). The wheels rise up automatically when the machine leaves the ground, so that it may alight on the runners. "A Duthirt & Chalmers 2-cylinder opposed, 3 1/8-inch engine was used first, and several hundred short flights were made. The engine gave four brake h. p., which was barely sufficient for continued flight. The aeroplane complete with this engine weighed 78 pounds. The engine now used is a Bates 3 5/8-inch, 2-cylinder opposed, showing 8 h. p., and apparently giving plenty of power. The weight of aeroplane with this engine is now 110 pounds. Owing to poor grounds only short flights have been made, the longest to date (Dec. 31, 1910) being about 1,000 feet. "In building the present machine, my object was to produce a safe, slow, light, and small h. p. aeroplane, a purpose which I have accomplished." CHAPTER XXVII. 1911 AEROPLANE RECORDS. THE WORLD AT LARGE. Greatest Speed Per Hour, Whatever Length of Flight, Aviator Alone--E. Nieuport, Mourmelon, France, June 21, Nieuport Machine, 82.72 miles; with one passenger, E. Nieuport, Moumlelon, France, June 12, Nieuport Machine, 67.11 miles; with two passengers, E. Nieuport, Mourmelon, France, March 9, Nieuport Machine, 63.91 miles; with three passengers, G. Busson, Rheims, France, March 10, Deperdussin Machine, 59.84 miles; with four passengers, G. Busson, Rheims, France, March 10, Deperdussin Machine, 54.21 miles. Greatest Distance Aviator Alone--G. Fourny, no stops, Buc, France, September 2, M. Farman Machine, 447.01 miles; E. Helen, three stops, Etampes, France, September 8, Nieuport Machine, 778.45 miles; with one passenger, Lieut. Bier, Austria, October 2, Etrich Machine, 155.34 miles; with two passengers, Lieut. Bier, Austria, October 4, Etrich Machine, 69.59 miles; with three passengers, G. Busson, Rheims, France, March 10, Deperdussin Machine, 31.06 miles; with four passengers, G. Busson, Rheims, France, March 10, Deperdussin Machine, 15.99 miles. Greatest Duration Aviator Alone--G. Fourny, no stops, Buc, France, September 2, M. Farman Machine, 11 hours, 1 minute, 29 seconds, E. Helen, three stops, Etampes, France, September 8, Nieuport Machine, 14 hours, 7 minutes, 50 seconds, 13 hours, 17 minutes net time; with one passenger, Suvelack, Johannisthal, Germany, December 8, 4 hours, 23 minutes; with two passengers, T. de W. Milling, Nassau Boulevard, New York, September 26, Burgess-Wright Machine, 1 hour, 54 minutes, 42 3-5 seconds; with three passengers, Warchalowski, Wiener-Neustadt, Aust., October 30, 45 minutes, 46 seconds; with four passengers, G. Busson, Rheims, France, March 10, Deperdussin Machine, 17 minutes, 28 1-5 seconds. Greatest Altitude Aviator Alone--Garros, St. Malo, France, September 4, Bleriot Machine, 13,362 feet; with one passenger, Prevost, Courcy, France, December 2, 9,840 feet; with two passengers, Lieut. Bier, Austria, Etrich Machine, 4,010 feet. AMERICAN RECORDS. Greatest Speed Per Hour, Whatever Length of Flight, Aviator Alone--A. Leblanc, Belmont Park, N. Y., October 29, Bleriot Machine, 67.87 miles; with one passenger, C. Grahame-White, Squantum, Mass., September 4, Nieuport Machine, 63.23 miles; with two passengers, T. O. M. Sopwith, Chicago, Ill., August 15, Wright Machine, 34.96 miles. Greatest Distance Aviator Alone--St. Croix Johnstone, Mineola, N. Y., July 27, Moisant (Bleriot Type) Machine, 176.23 miles. Greatest Duration Aviator Alone--Howard W. Gill, Kinloch, Mo., October 19, Wright Machine, 4 hours, 16 minutes, 35 seconds; with one passenger, G. W. Beatty, Chicago, Ill., August 19, Wright Machine, 3 hours, 42 minutes, 22 1-5 seconds; with two passengers, T. de W. Milling, Nassau Boulevard, N. Y., September 26, Burgess-Wright Machine, 1 hour, 54 minutes, 42 3-5 seconds. Greatest Altitude Aviator Alone--L. Beachy, Chicago, Ill., August 20, Curtiss Machine, 11,642 feet; with one passenger, C. Grahame-White, Nassau Boulevard, N. Y., September 30, Nieuport Machine, 3,347 feet. Weight Carrying--P. O. Parmelee, Chicago, III., August 19, Wright Machine, 458 lbs. AVIATION DEVELOPMENT. The wonderful progress made in the science of aviation during the year 1911 far surpasses any twelve months' advancement recorded. The advancement has not been confined to any country or continent, since every part of the world is taking its part in aviation history making. The rapidly increasing interest in aviation has brought forth schools for the instruction of flying in both the old and new world, and licensed air pilots before they receive their sanctions from the governing aero clubs of their country are required to pass an extremely trying examination in actual flights. Exhibition flights and races were common in all parts of the world during 1911, and touring aviators visited India, China, Japan, South Africa, Australia and South America, giving exhibitions and instruction. Europe was the scene of a number of cross-country races in which entries ranging from ten to twenty aviators flew from city to city around a given circuit, which in some instances exceeded 1,000 miles in distance. Cross-country flights with and without passengers became so common that those of less than two hours' duration attracted little attention. There were fewer attempts at high altitude soaring, although the world's record in this department of aviation was bettered several times. In place of these high flights, the aviators devoted more attention to speed, duration and spectacular manoeuvres, which appeared to satisfy the spectators. The prize money won during 1911 exceeded $1,000,000, but owing to the increased number of aviators the individual winnings were not as large as in 1910. It is estimated that within the past twelve months more than 300,000 miles have been covered in aeroplane flights and more than seven thousand persons, classed either as aviators or passengers, taken up into the air. The aeroplane of today ranges through monoplane, biplane, triplane and even quadraplane, and more than two hundred types of these machines are in use. Aeroplanes are becoming a factor of international commerce. The records of the Bureau of Statistics show that more than $50,000 worth of aeroplanes were imported into, and exported from, the United States in the months of July, August and September, 1911. The Bureau of Statistics only began the maintenance of a separate record of this comparatively new article of commerce with the opening of the fiscal year 1911-12. Two of the prominent developments of 1911 were the introduction of the hydro-aeroplane and the motorless glider experiments of the Wright brothers at Killdevil Hills, N. C., where during the two weeks' experiments numerous flights with and against the wind were made, culminating in the establishing of a record by Orville Wright on October 25, 1911, when in a 52-mile per hour blow he reached an elevation of 225 feet and remained in the air 10 minutes and 34 seconds. The search for the secret of automatic stability still continues, and though some remarkable progress has been made the solution has not yet been reached. NOTABLE CROSS-COUNTRY FLIGHTS OF 1911. One of the important features of 1911 in aviation was the rapid increase in the number and distance of cross-country flights made either for the purpose of exhibition, testing, instruction or pleasure. Flights between cities in almost every country of the world became common occurrences. So great was the number that only those of more than ordinary importance because of speed, distance or duration are recorded. The flights of Harry N. Atwood from Boston to Washington and from St. Louis to New York, and C. P. Rodgers from New York to Los Angeles were the most important events of the kind in this country. The St Louis to New York flight was a distance by air route, 1,266 miles. Duration of flight, 12 days. Net flying time, 28 hours 53 minutes. Average daily flight, 105.5 miles. Average speed, 43.9 miles per hour. Transcontinental Flight of Calbraith P. Rodgers.--All world records for cross-country flying were broken during the New York to Los Angeles flight of Calbraith P. Rodgers, who left Sheepshead Bay, N. Y., on Sunday, September 17, 1911, and completed his flight to the Pacific Coast on Sunday, November 5, at Pasadena, Cal. Rodgers flew a Wright biplane, and during his long trip the machine was repeatedly repaired, so great was the strain of the long journey in the air. Rodgers is estimated to have covered 4,231 miles, although the actual route as mapped out was but 4,017 miles. Elapsed time to Pasadena, Cal., 49 days; actual time in the air, 4,924 minutes, equivalent to 3 days 10 hours 4 minutes; average speed approximating 51 miles per hour. Rodgers' longest flight in one day was from Sanderson to Sierra Blanca, Texas, on October 28, when he covered 231 miles. On November 12, Rodgers fell at Compton, Cal., and was badly injured, causing a delay of 28 days. European Circuit Race.--Started from Paris on June 18, 1911. Distance, 1,073 miles, via Paris to Liege; Liege to Spa to Liege; Liege to Utrecht, Holland; Utrecht to Brussels, Belgium; Brussels to Roubaix; Roubaix to Calais; Calais to London; London to Calais and Calais to Paris. Three aeronauts were killed either at the start or shortly after the race was in progress. They were Capt. Princetau, M. Le Martin and M. Lendron. Three others were injured by falls. Seven hundred thousand spectators witnessed the start from the aviation field at Vincennes, near Paris. There were more than forty starters, of which eight finished. The winner, Lieut. Jean Conneau, who flies under the name of "Andre Beaumont," completed the circuit on July 7; his actual net flying time for the distance being 58h. 38m. 4-5s. Circuit of England Race--1,010 Miles in Five Sections.-- Start, July 22. Finish, July 26. Prize, $50,000. Twenty-eight entries and eighteen starters. Seventeen finished the first section from Brooklands to Hendon, a distance of twenty miles. Five reached Edinburgh, the second section, a distance of 343 miles, and four completed the entire circuit. Paris to Madrid Race.--This race was started at the Paris aviation held at Issy-les-Moulineaux on Sunday, May 21. There were twenty-one entrants, and fully 300,000 spectators gathered to witness the initial flight of the aerial races. The race was divided into three stages as follows: Paris to Angouleme, 248 miles; Angouleme to St. Sebastian, 208 miles, and from St. Sebastian to Madrid, 386 miles, a total distance of 842 miles. After three of the entrants had safely left the field, Aviator Train lost control of his plane, and in falling struck and killed M. Berteaux, the French Minister of War, and seriously injured Premier Monis. The accident caused the withdrawal of all but six of the original entrants, and of these but one finished. The race called for a flight over the Pyrenees Mountains, and Vedrines, the winner, had to rise to a height of more than 7,000 feet to pass the mountain barrier near Somosierra Pass. Both Vedrines and Gibert, another competitor, were attacked by eagles during the latter stages of the flight. Vedrines, who started from Paris on Monday, May 22, finished the long and perilous race at 8:06 a. m. Friday, May 26. Vedrines net flying time, all controls and enforced stops subtracted, was 14h. 55m. 18s. The various prizes to the winner aggregated $30,000. The Paris-Rome-Turin Race.--The conditions of this race called for a flight between the cities of Paris, Rome and Turin, covering a distance of 1,300 miles. The aviators were permitted by the rules to alight whenever and wherever they desired and the time limit was set from May 28 to June 15. A prize of $100,000 was offered the winner, but the contest was never finished, as one after another the aviators dropped out until Frey fell near Roncigilione, France, breaking both arms and legs and unofficially ending the contest. There were twenty-one entries and twelve actual starters. International Speed Cup Race.--The third annual international James Gordon Bennett speed cup race was held at Eastchurch, England, on July 1, 1911, and for the second time was won by an American aviator, C. T. Weymann, in a French racing aeroplane. The distance was 150 kilometres equivalent to 94 miles, and the winner's time of 1h. 11m. 36s. showed an average speed of 78.77 miles per hour. The first race was held in 1909 and was won by Glenn Curtiss, who flew the twenty kilometres (12.4 miles) in 15 minutes 50 2-5 seconds at an average speed of 47 miles per hour. In 1910 the winner was Grahame-White, who covered 100 kilometres (62 miles) at Belmont Park, L. I., in 60 minutes 47 3-5 seconds, an average speed of 61.3 miles per hour. In the 1911 race there were six starters: three from France, two from Great Britain and one from the United States. Milan to Turin to Milan Race.--This race which was started from Milan, Italy, on October 29, was restricted to Italian aviators and had six starters. The distance was approximately 177 miles and won by Manissero in a Bleriot machine in 3h. 16m. 2 4-5s. New York to Philadelphia Race.--The first intercity aeroplane race ever held in the United States was started from New York City on August 5, and finished in Philadelphia the same day. The prize of $5,000 was offered by a commercial concern with stores in the two cities: Three entrants competed from the Curtiss Exhibition Company. The distance was approximately 83 miles and won by L. Beachey in a Curtiss machine in 1h. 50m. at an average speed of 45 miles per hour. Tri-State Race.--The tri-state race was the feature event of the Harvard Aviation Society meet held at Squantum, Mass., August 26 to September 6. It was held Labor Day, September 4, over a course of 174 miles, from Boston to Nashua to Worcester to Providence to Boston. Four competitors started, of which two finished, the winner, E. Ovington, in a Bleriot machine. Ovington's net flying time, 3h. 6m. 22 1-5s. Winner's prize, $10,000. AEROPLANES AND DIRIGIBLE BALLOONS IN WARFARE. Wonderful progress has been made in the development of the aeroplane in this country and in Europe since 1903, and within the last two or three years the leading powers of the world have entered upon extensive tests and experiments to determine its availability and usefulness in land and naval warfare. At the present time all the great powers are building or purchasing aeroplanes on an extensive scale. They have established government schools for the instruction of their army and navy officers and for experimental work. So-called "Airship Fleets" have been constructed and placed in commission as auxiliaries to the armies and navies. The fleets of France and Germany are about equal and are larger by far than those of any of the other powers. The length of the dirigibles composing these fleets runs from 150 to 500 feet; they are equipped with engines of from 50 to 500 horse-power, with a rate of speed ranging from 20 to 30 miles per hour. Their approximate range is from 200 to 900 miles; the longest actual run (made by the Zeppelin II, Germany) is 800 miles. A British naval airship, one of the largest yet built, was completed last summer. It has cost over $200,000, and it was in course of designing and construction two years. It is 510 feet long; can carry 22 persons, and has a lift of 21 tons. The relative value of the dirigible balloon and the aeroplane in actual war is yet to be determined. The dirigible is considered to be the safer, yet several large balloons of this class in Germany and France have met with disaster, involving loss of lives. The capacity of the dirigible for longer flights and its superior facilities for carrying apparatus and operators for wireless telegraphy are distinct advantages. There has not yet been much opportunity to test the airship in actual warfare. The aeroplane has been used by the Italians in Tripoli for scouting and reconnoitering and is said to have justified expectations. On several occasions the Italian military aviators followed the movements of the enemy, in one instance as far as forty miles inland. At the time of the attack by the Turks a skillful aeroplane reconnaissance revealed the approach of a large Turkish force, believed to be at the time sixty miles away in the mountains. Aeroplanes and airships, as they exist today, would doubtless render very valuable service in a time of war, both over land and water, in scouting, reconnoitering, carrying dispatches, and as some experts believe, in locating submarines and mines placed by the enemy in channels of exits from ports. A "coast aeroplane" could fly out 30 or 40 miles from land, and rising to a great height, descry any hostile ships on the distant horizon, observe their number, strength, formation and direction, and return within two hours with a report to obtain which would require several swift torpedo-boat destroyers and a much greater time. The question as to whether it would be practicable to bombard an enemy on land or sea with explosive bombs dropped or discharged from flying machines or airships, is one which is much discussed but hardly yet determined. Aeroplanes have been constructed with floats in the place of runners and several attempts have been made, in some cases successfully, to light with them on and to rise from the water. Mr. Curtiss did this at San Francisco, in January, 1911. Attempts have also been made with the aeroplane to alight on and to take flight from the deck of a warship. Toward the end of 1910 Aviator Ely flew to land from the cruiser Birmingham, and in January, 1911, he flew from land and alighted on the cruiser Pennsylvania. But in these cases special arrangements were made which would be hardly practicable in a time of actual war. In November, 1911, a test was made at Newport, R. I., by Lieut. Rodgers, of the navy, of a "hydro-areoplane" as an auxiliary to a battleship. The idea of the test was to alight alongside of the ship, hoist the machine aboard, put out to sea and launch the machine again with the use of a crane. Lieut. Rodgers came down smoothly alongside the Ohio, his machine was easily drawn aboard with a crane, and the Ohio steamed down to the open sea, where it was blowing half a gale. But, owing to the misjudgment of the ship's headway, one of the wings of the machine when it struck the water after being released from the crane, went under the water and was snapped off. Lieut. Rodgers was convinced that this method was too risky and that some other must be devised. CHAPTER XXVIII. GLOSSARY OF AERONAUTICAL TERMS. Aerodrome.--Literally a machine that runs in the air. Aerofoil.--The advancing transverse section of an aeroplane. Aeroplane.--A flying machine of the glider pattern, used in contra-distinction to a dirigible balloon. Aeronaut.--A person who travels in the air. Aerostat.--A machine sustaining weight in the air. A balloon is an aerostat. Aerostatic.--Pertaining to suspension in the air; the art of aerial navigation. Ailerons.--Small stabilizing planes attached to the main planes to assist in preserving equilibrium. Angle of Incidence.--Angle formed by making comparison with a perpendicular line or body. Angle of Inclination.--Angle at which a flying machine rises. This angle, like that of incidence, is obtained by comparison with an upright, or perpendicular line. Auxiliary Planes.--Minor plane surfaces, used in conjunction with the main planes for stabilizing purposes. Biplane.--A flying-machine of the glider type with two surface planes. Blade Twist.--The angle of twist or curvature on a propeller blade. Cambered.--Curve or arch in plane, or wing from port to starboard. Chassis.--The under framework of a flying machine; the framework of the lower plane. Control.--System by which the rudders and stabilizing planes are manipulated. Dihedral.--Having two sides and set at an angle, like dihedral planes, or dihedral propeller blades. Dirigible.--Obedient to a rudder; something that may be steered or directed. Helicopter.--Flying machine the lifting power of which is furnished by vertical propellers. Lateral Curvature.--Parabolic form in a transverse direction. Lateral Equilibrium or Stability.--Maintenance of the machine on an even keel transversely. If the lateral equilibrium is perfect the extreme ends of the machine will be on a dead level. Longitudinal Equilibrium or Stability.--Maintenance of the machine on an even keel from front to rear. Monoplane.--Flying machine with one supporting, or surface plane. Multiplane.--Flying machine with more than three surface planes. Ornithopter.--Flying machine with movable bird-like wings. Parabolic Curves.--Having the form of a parabola--a conic section. Pitch of Propeller Blade.--See "Twist." Ribs.--The pieces over which the cloth covering is stretched. Spread.--The distance from end to end of the main surface; the transverse dimension. Stanchions.--Upright pieces connecting the upper and lower frames. Struts.--The pieces which hold together longitudinally the main frame beams. Superposed.--Placed one over another. Surface Area.--The amount of cloth-covered supporting surface which furnishes the sustaining quality. Sustentation.--Suspension in the air. Power of sustentation; the quality of sustaining a weight in the air. Triplane.--Flying machine with three surface planes. Thrust of Propeller.--Power with which the blades displace the air. Width.--The distance from the front to the rear edge of a flying machine. Wind Pressure.--The force exerted by the wind when a body is moving against it. There is always more or less wind pressure, even in a calm. Wing Tips.--The extreme ends of the main surface planes. Sometimes these are movable parts of the main planes, and sometimes separate auxiliary planes. Footnotes: [Footnote 1: Now dead.] [Footnote 2: Aeronautics.] [Footnote 3: See Chapter XXV.] [Footnote 4: The Wrights' new machine weighs only 900 pounds.] [Footnote 5: Aeronautics.] 
861	----	THE DOMINION OF THE AIR The Story of Aerial Navigation by Rev. J. M. Bacon CHAPTER I. THE DAWN OF AERONAUTICS. "He that would learn to fly must be brought up to the constant practice of it from his youth, trying first only to use his wings as a tame goose will do, so by degrees learning to rise higher till he attain unto skill and confidence." So wrote Wilkins, Bishop of Chester, who was reckoned a man of genius and learning in the days of the Commonwealth. But so soon as we come to inquire into the matter we find that this good Bishop was borrowing from the ideas of others who had gone before him; and, look back as far as we will, mankind is discovered to have entertained persistent and often plausible ideas of human flight. And those ideas had in some sort of way, for good or ill, taken practical shape. Thus, as long ago as the days when Xenophon was leading back his warriors to the shores of the Black Sea, and ere the Gauls had first burned Rome, there was a philosopher, Archytas, who invented a pigeon which could fly, partly by means of mechanism, and partly also, it is said, by aid of an aura or spirit. And here arises a question. Was this aura a gas, or did men use it as spiritualists do today, as merely a word to conjure with? Four centuries later, in the days of Nero, there was a man in Rome who flew so well and high as to lose his life thereby. Here, at any rate, was an honest man, or the story would not have ended thus; but of the rest--and there are many who in early ages aspired to the attainment of flight--we have no more reason to credit their claims than those of charlatans who flourish in every age. In medieval times we are seriously told by a saintly writer (St. Remigius) of folks who created clouds which rose to heaven by means of "an earthen pot in which a little imp had been enclosed." We need no more. That was an age of flying saints, as also of flying dragons. Flying in those days of yore may have been real enough to the multitude, but it was at best delusion. In the good old times it did not need the genius of a Maskelyne to do a "levitation" trick. We can picture the scene at a "flying seance." On the one side the decidedly professional showman possessed of sufficient low cunning; on the other the ignorant and highly superstitious audience, eager to hear or see some new thing--the same audience that, deceived by a simple trick of schoolboy science, would listen to supernatural voices in their groves, or oracular utterances in their temples, or watch the urns of Bacchus fill themselves with wine. Surely for their eyes it would need no more than the simplest phantasmagoria, or maybe only a little black thread, to make a pigeon rise and fly. It is interesting to note, however, that in the case last cited there is unquestionably an allusion to some crude form of firework, and what more likely or better calculated to impress the ignorant! Our firework makers still manufacture a "little Devil." Pyrotechnic is as old as history itself; we have an excellent description of a rocket in a document at least as ancient as the ninth century. And that a species of pyrotechny was resorted to by those who sought to imitate flight we have proof in the following recipe for a flying body given by a Doctor, eke a Friar, in Paris in the days of our King John:-- "Take one pound of sulphur, two pounds of willowcarbon, six pounds of rock salt ground very fine in a marble mortar. Place, when you please, in a covering made of flying papyrus to produce thunder. The covering in order to ascend and float away should be long, graceful, well filled with this fine powder; but to produce thunder the covering should be short, thick, and half full." Nor does this recipe stand alone. Take another sample, of which chapter and verse are to be found in the MSS. of a Jesuit, Gaspard Schott, of Palermo and Rome, born three hundred years ago:-- "The shells of hen-eggs, if properly filled and well secured against the penetration of the air, and exposed to solar rays, will ascend to the skies and sometimes suffer a natural change. And if the eggs of the larger description of swans, or leather balls stitched with fine thongs, be filled with nitre, the purest sulphur quicksilver, or kindred materials which rarify by their caloric energy, and if they externally resemble pigeons, they will easily be mistaken for flying animals." Thus it would seem that, hunting back in history, there were three main ideas on which would-be aeronauts of old exercised their ingenuity. There was the last-mentioned method, which, by the way, Jules Verne partly relies on when he takes his heroes to the moon, and which in its highest practical development may be seen annually on the night of "Brock's Benefit" at the Crystal Palace. There is, again, the "tame goose" method, to which we must return presently; and, lastly, there is a third method, to which, as also to the brilliant genius who conceived it, we must without further delay be introduced. This may be called the method of "a hollow globe." Roger Bacon, Melchisedeck-fashion, came into existence at Ilchester in 1214 of parentage that is hard to trace. He was, however, a born philosopher, and possessed of intellect and penetration that placed him incalculably ahead of his generation. A man of marvellous insight and research, he grasped, and as far as possible carried out, ideas which dawned on other men only after centuries. Thus, many of his utterances have been prophetic. It is probable that among his chemical discoveries he re-invented gunpowder. It is certain that he divined the properties of a lens, and diving deep into experimental and mechanical sciences, actually foresaw the time when, in his own words, "men would construct engines to traverse land and water with great speed and carry with them persons and merchandise." Clearly in his dreams Bacon saw the Atlantic not merely explored, but on its bosom the White Star liners breaking records, contemptuous of its angriest seas. He saw, too, a future Dumont circling in the air, and not only in a dead calm, but holding his own with the feathered race. He tells his dream thus: "There may be made some flying instrument so that a man sitting in the middle of the instrument and turning some mechanism may put in motion some artificial wings which may beat the air like a bird flying." But he lived too long before his time. His ruin lay not only in his superior genius, but also in his fearless outspokenness. He presently fell under the ban of the Church, through which he lost alike his liberty and the means of pursuing investigation. Had it been otherwise we may fairly believe that the "admirable Doctor," as he was called, would have been the first to show mankind how to navigate the air. His ideas are perfectly easy to grasp. He conceived that the air was a true fluid, and as such must have an upper limit, and it would be on this upper surface, he supposed, as on the bosom of the ocean, that man would sail his air-ship. A fine, bold guess truly. He would watch the cirrus clouds sailing grandly ten miles above him on some stream that never approached nearer. Up there, in his imagination, would be tossing the waves of our ocean of air. Wait for some little better cylinders of oxygen and an improved foot-warmer, and a future Coxwell will go aloft and see; but as to an upper sea, it is truly there, and we may visit and view its sun-lit tossing billows stretching out to a limitless horizon at such times as the nether world is shrouded in densest gloom. Bacon's method of reaching such an upper sea as he postulated was, as we have said, by a hollow globe. "The machine must be a large hollow globe, of copper or other suitable metal, wrought extremely thin so as to have it as light as possible," and "it must be filled with ethereal air or liquid fire." This was written in the thirteenth century, and it is scarcely edifying to find four hundred years after this the Jesuit Father Lana, who contrived to make his name live in history as a theoriser in aeronautics, arrogating to himself the bold conception of the English Friar, with certain unfortunate differences, however, which in fairness we must here clearly point out. Lana proclaimed his speculations standing on a giant's shoulders. Torricelli, with his closed bent tube, had just shown the world how heavily the air lies above us. It then required little mathematical skill to calculate what would be the lifting power of any vessel void of air on the earth's surface. Thus Lana proposed the construction of an air ship which possibly because of its picturesquesness has won him notoriety. But it was a fraud. We have but to conceive a dainty boat in which the aeronaut would sit at ease handling a little rudder and a simple sail. These, though a schoolboy would have known better, he thought would guide his vessel when in the air. So much has been claimed for Father Lana and his mathematical and other attainments that it seems only right to insist on the weakness of his reasoning. An air ship simply drifting with the wind is incapable of altering its course in the slightest degree by either sail or rudder. It is simply like a log borne along in a torrent; but to compare such a log properly with the air ship we must conceive it WHOLLY submerged in the water and having no sail or other appendage projecting into the air, which would, of course, introduce other conditions. If, however, a man were to sit astride of the log and begin to propel it so that it travels either faster or slower than the stream, then in that case, either by paddle or rudder, the log could be guided, and the same might be said of Lana's air boat if only he had thought of some adequate paddle, fan, or other propeller. But he did not. One further explanatory sentence may here be needed; for we hear of balloons which are capable of being guided to a small extent by sail and rudder. In these cases, however, the rudder is a guide rope trailing on earth or sea, so introducing a fresh element and fresh conditions which are easy to explain. Suppose a free balloon drifting down the wind to have a sail suddenly hoisted on one side, what happens? The balloon will simply swing till this sail is in front, and thus continue its straightforward course. Suppose, however, that as soon as the side sail is hoisted a trail rope is also dropped aft from a spar in the rigging. The tendency of the sail to fly round in front is now checked by the dragging rope, and it is constrained to remain slanting at an angle on one side; at the same time the rate of the balloon is reduced by the dragging rope, so that it travels slower than the wind, which, now acting on its slant sail, imparts a certain sidelong motion much as it does in the case of a sailing boat. Lana having in imagination built his ship, proceeds to make it float up into space, for which purpose he proposes four thin copper globes exhausted of air. Had this last been his own idea we might have pardoned him. We have, however, pointed out that it was not, and we must further point out that in copying his great predecessor he fails to see that he would lose enormous advantage by using four globes instead of one. But, beyond all, he failed to see what the master genius of Bacon saw clearly--that his thin globes when exhausted must infallibly collapse by virtue of that very pressure of the air which he sought to make use of. It cannot be too strongly insisted on that if the too much belauded speculations of Lana have any value at all it is that they throw into stronger contrast the wonderful insight of the philosopher who so long preceded him. By sheer genius Bacon had foreseen that the emptied globe must be filled with SOMETHING, and for this something he suggests "ethereal air" or "liquid fire," neither of which, we contend, were empty terms. With Bacon's knowledge of experimental chemistry it is a question, and a most interesting one, whether he had not in his mind those two actual principles respectively of gas and air rarefied by heat on which we launch our balloons into space to-day. Early progress in any art or science is commonly intermittent. It was so in the story of aeronautics. Advance was like that of the incoming tide, throwing an occasional wave far in front of its rising flood. It was a phenomenal wave that bore Roger Bacon and left his mark on the sand where none other approached for centuries. In those centuries men were either too priest-ridden to lend an ear to Science, or, like children, followed only the Will-o'-the-Wisp floating above the quagmire which held them fast. They ran after the stone that was to turn all to gold, or the elixir that should conquer death, or the signs in the heavens that should foretell their destinies; and the taint of this may be traced even when the dark period that followed was clearing away. Four hundred years after Roger's death, his illustrious namesake, Francis Bacon, was formulating his Inductive Philosophy, and with complete cock-sureness was teaching mankind all about everything. Let us look at some of his utterances which may help to throw light on the way he regarded the problem we are dealing with. "It is reported," Francis Bacon writes, "that the Leucacians in ancient time did use to precipitate a man from a high cliffe into the sea; tying about him, with strings, at some distance, many great fowles; and fixing unto his body divers feathers, spread, to breake the fall. Certainly many birds of good wing (as Kites and the like) would beare up a good weight as they flie. And spreading of feathers, thin and close, and in great breadth, will likewise beare up a great weight, being even laid without tilting upon the sides. The further extension of this experiment of flying may be thought upon." To say the least, this is hardly mechanical. But let us next follow the philosopher into the domain of Physics. Referring to a strange assertion, that "salt water will dissolve salt put into it in less time than fresh water will dissolve it," he is at once ready with an explanation to fit the case. "The salt," he says, "in the precedent water doth by similitude of substance draw the salt new put in unto it." Again, in his finding, well water is warmer in winter than summer, and "the cause is the subterranean heat which shut close in (as in winter) is the more, but if it perspire (as it doth in summer) it is the less." This was Bacon the Lord. What a falling off--from the experimentalist's point of view--from Bacon the Friar! We can fancy him watching a falcon poised motionless in the sky, and reflecting on that problem which to this day fairly puzzles our ablest scientists, settling the matter in a sentence: "The cause is that feathers doe possess upward attractions." During four hundred years preceding Lord Verulam philosophers would have flown by aid of a broomstick. Bacon himself would have merely parried the problem with a platitude! At any rate, physicists, even in the brilliant seventeenth century, made no material progress towards the navigation of the air, and thus presently let the simple mechanic step in before them. Ere that century had closed something in the nature of flight had been accomplished. It is exceedingly hard to arrive at actual fact, but it seems pretty clear that more than one individual, by starting from some eminence, could let himself fall into space and waft himself away for some distance with fair success and safety, It is stated that an English Monk, Elmerus, flew the space of a furlong from a tower in Spain, a feat of the same kind having been accomplished by another adventurer from the top of St. Mark's at Venice. In these attempts it would seem that the principle of the parachute was to some extent at least brought into play. If also circumstantial accounts can be credited, it would appear that a working model of a flying machine was publicly exhibited by one John Muller before the Emperor Charles V. at Nuremberg. Whatever exaggeration or embellishment history may be guilty of it is pretty clear that some genuine attempts of a practical and not unsuccessful nature had been made here and there, and these prompted the flowery and visionary Bishop Wilkins already quoted to predict confidently that the day was approaching when it "would be as common for a man to call for his wings as for boots and spurs." We have now to return to the "tame goose" method, which found its best and boldest exponent in a humble craftsman, by name Besnier, living at Sable, about the year 1678. This mechanical genius was by trade a locksmith, and must have been possessed of sufficient skill to construct an efficient apparatus out of such materials as came to his hand, of the simplest possible design. It may be compared to the earliest type of bicycle, the ancient "bone shaker," now almost forgotten save by those who, like the writer, had experience of it on its first appearance. Besnier's wings, as it would appear, were essentially a pair of double-bladed paddles and nothing more, roughly resembling the double-paddle of an old-fashioned canoe, only the blades were large, roughly rectangular, and curved or hollowed. The operator would commence by standing erect and balancing these paddles, one on each shoulder, so that the hollows of the blades should be towards the ground. The forward part of each paddle was then grasped by the hands, while the hinder part of each was connected to the corresponding leg. This, presumably, would be effected after the arms had been raised vertically, the leg attachment being contrived in some way which experience would dictate. The flyer was now fully equipped, and nothing remained for him save to mount some eminence and, throwing himself forward into space and assuming the position of a flying bird, to commence flapping and beating the air with a reciprocal motion. First, he would buffet the air downwards with the left arm and right leg simultaneously, and while these recovered their position would strike with the right hand and left leg, and so on alternately. With this crude method the enterprising inventor succeeded in raising himself by short stages from one height to another, reaching thus the top of a house, whence he could pass over others, or cross a river or the like. The perfecting of his system became then simply a question of practice and experience, and had young athletes only been trained from early years to the new art it seems reasonable to suppose that some crude approach to human flight would have been effected. Modifications and improvements in construction would soon have suggested themselves, as was the case with the bicycle, which in its latest developments can scarcely be recognised as springing from the primitive "bone-shaker" of thirty-three years ago. We would suggest the idea to the modern inventor. He will in these days, of course, find lighter materials to hand. Then he will adopt some link motion for the legs in place of leather thongs, and will hinge the paddle blades so that they open out with the forward stroke, but collapse with the return. Then look on another thirty-three years--a fresh generation--and our youth of both sexes may find a popular recreation in graceful aerial exercise. The pace is not likely to be excessive, and molestations from disguised policemen--not physically adapted, by the way, to rapid flight--need not be apprehended. One of the best tests of Besnier's measure of success is supplied by the fact that he had pupils as well as imitators. First on this list must be mentioned a Mr. Baldwin, a name which, curiously enough, twice over in modern times comes into the records of bold aerial exploits. This individual, it appears, purchased a flying outfit of Besnier himself, and surpassed his master in achievement. A little later one Dante contrived some modification of the same apparatus, with which he pursued the new mode of progress till he met with a fractured thigh. But whatever the imitators of Besnier may have accomplished, to the honest smith must be accorded the full credit of their success, and with his simple, but brilliant, record left at flood mark, the tide of progress ebbed back again, while mankind ruminated over the great problem in apparent inactivity. But not for long. The air-pump about this period was given to the world, and chemists were already busy investigating the nature of gases. Cavallo was experimenting on kindred lines, while in our own land the rival geniuses of Priestley and Cavendish were clearing the way to make with respect to the atmosphere the most important discovery yet dreamed of. In recording this dawn of a new era, however, we should certainly not forget how, across the Atlantic, had arisen a Rumford and a Franklin, whose labours were destined to throw an all-important sidelight on the pages of progress which we have now to chronicle. CHAPTER II. THE INVENTION OF THE BALLOON. It was a November night of the year 1782, in the little town of Annonay, near Lyons. Two young men, Stephen and Joseph Montgolfier, the representatives of a firm of paper makers, were sitting together over their parlour fire. While watching the smoke curling up the chimney one propounded an idea by way of a sudden inspiration: "Why shouldn't smoke be made to raise bodies into the air?" The world was waiting for this utterance, which, it would seem, was on the tip of the tongue with many others. Cavendish had already discovered what he designated "inflammable air," though no one had as yet given it its later title of hydrogen gas. Moreover, in treating of this gas--Dr. Black of Edinburgh, as much as fifteen years before the date we have now arrived at, had suggested that it should be made capable of raising a thin bladder in the air. With a shade more of good fortune, or maybe with a modicum more of leisure, the learned Doctor would have won the invention of the balloon for his own country. Cavallo came almost nearer, and actually putting the same idea into practice, had succeeded in the spring of 1782 in making soap bubbles blown with hydrogen gas float upwards. But he had accomplished no more when, as related, in the autumn of the same year the brothers Montgolfier conceived the notion of making bodies "levitate" by the simpler expedient of filling them with smoke. This was the crude idea, the application of which in their hands was soon marked with notable success. Their own trade supplied ready and suitable materials for a first experiment, and, making an oblong bag of thin paper a few feet in length, they proceeded to introduce a cloud of smoke into it by holding crumpled paper kindled in a chafing dish beneath the open mouth. What a subject is there here for an imaginative painter! As the smoky cloud formed within, the bag distended itself, became buoyant, and presently floated to the ceiling. The simple trial proved a complete success, due, as it appeared to them, to the ascensive power of a cloud of smoke. An interesting and more detailed version of the story is extant. While the experiment was in progress a neighbour, the widow of a tradesman who had been connected in business with the firm, seeing smoke escaping into the room, entered and stood watching the proceedings, which were not unattended with difficulties. The bag, half inflated, was not easy to hold in position over the chafing dish, and rapidly cooled and collapsed on being removed from it. The widow noting this, as also the perplexity of the young men, suggested that they should try the result of tying the dish on at the bottom of the bag. This was the one thing wanted to secure success, and that good lady, whose very name is unhappily lost, deserves an honoured place in history. It was unquestionably the adoption of her idea which launched the first balloon into space. The same experiment repeated in the open air proving a yet more pronounced success, more elaborate trials were quickly developed, and the infant balloon grew fast. One worthy of the name, spherical in shape and of some 600 cubic feet capacity, was now made and treated as before, with the result that ere it was fully inflated it broke the strings that held it and sailed away hundreds of feet into the air. The infant was fast becoming a prodigy. Encouraged by their fresh success, the inventors at once set about preparations for the construction of a much larger balloon some thirty-five feet diameter (that is, of about 23,000 cubic feet capacity), to be made of linen lined with paper and this machine, launched on a favourable day in the following spring, rose with great swiftness to fully a thousand feet, and travelled nearly a mile from its starting ground. Enough; the time was already ripe for a public demonstration of the new invention, and accordingly the 5th of the following June witnessed the ascent of the same balloon with due ceremony and advertisement. Special pains were taken with the inflation, which was conducted over a pit above which the balloon envelope was slung; and in accordance with the view that smoke was the chief lifting power, the fuel was composed of straw largely mixed with wool. It is recorded that the management of the furnace needed the attention of two men only, while eight men could hardly hold the impatient balloon in restraint. The inflation, in spite of the fact that the fuel chosen was scarcely the best for the purpose, was conducted remarkable expedition, and on being released, the craft travelled one and a half miles into the air, attaining a height estimated at over 6,000 feet. From this time the tide of events in the aeronautical world rolls on in full flood, almost every half-year marking a fresh epoch, until a new departure in the infant art of ballooning was already on the point of being reached. It had been erroneously supposed that the ascent of the Montgolfier balloon had been due, not to the rarefaction of the air within it--which was its true cause--but to the evolution of some light gas disengaged by the nature of the fuel used. It followed, therefore, almost as a matter of course, that chemists, who, as stated in the last chapter, were already acquainted with so-called "inflammable air," or hydrogen gas, grasped the fact that this gas would serve better than any other for the purposes of a balloon. And no sooner had the news of the Montgolfiers' success reached Paris than a subscription was raised, and M. Charles, Professor of Experimental Philosophy, was appointed, with the assistance of M. Roberts, to superintend the construction of a suitable balloon and its inflation by the proposed new method. The task was one of considerable difficulty, owing partly to the necessity of procuring some material which would prevent the escape of the lightest and most subtle gas known, and no less by reason of the difficulty of preparing under pressure a sufficient quantity of gas itself. The experiment, sound enough in theory, was eventually carried through after several instructive failures. A suitable material was found in "lustring," a glossy silk cloth varnished with a solution of caoutchouc, and this being formed into a balloon only thirteen feet in diameter and fitted without other aperture than a stopcock, was after several attempts filled with hydrogen gas prepared in the usual way by the action of dilute sulphuric acid on scrap iron. The preparations completed, one last and all-important mistake was made by closing the stop-cock before the balloon was dismissed, the disastrous and unavoidable result of this being at the time overlooked. On August 25, 1783, the balloon was liberated on the Champ de Mars before an enormous concourse, and in less than two minutes had reached an elevation of half a mile, when it was temporarily lost in cloud, through which, however, it penetrated, climbing into yet higher cloud, when, disappearing from sight, it presently burst and descended to earth after remaining in the air some three-quarters of an hour. The bursting of this little craft taught the future balloonist his first great lesson, namely, that on leaving earth he must open the neck of his balloon; and the reason of this is obvious. While yet on earth the imprisoned gas of a properly filled balloon distends the silk by virtue of its expansive force, and in spite of the enormous outside pressure which the weight of air exerts upon it. Then, as the balloon rises high in the air and the outside pressure grows less, the struggling gas within, if allowed no vent, stretches the balloon more and more until the slender fabric bursts under the strain. At the risk of being tedious, we have dwelt at some length on the initial experiments which in less than a single year had led to the discovery and development of two distinct methods--still employed and in competition with each other--of dismissing balloons into the heavens. We are now prepared to enter fully into the romantic history of our subject which from this point rapidly unfolds itself. Some eleven months only after the two Montgolfiers were discovered toying with their inflated paper bag, the younger of the two brothers was engaged to make an exhibition of his new art before the King at Versailles, and this was destined to be the first occasion when a balloon was to carry a living freight into the sky. The stately structure, which was gorgeously decorated, towered some seventy feet into the air, and was furnished with a wicker car in which the passengers were duly installed. These were three in number, a sheep, a cock, and a duck, and amid the acclamations of the multitude, rose a few hundred feet and descended half a mile away. The cock was found to have sustained an unexplained mishap: its leg was broken; but the sheep was feeding complacently, and the duck was quacking with much apparent satisfaction. Now, who among mortals will come forward and win the honour of being the first to sail the skies? M. Pilitre de Rozier at once volunteered, and by the month of November a new air ship was built, 74 feet high, 48 feet in largest diameter, and 15 feet across the neck, outside which a wicker gallery was constructed, while an iron brazier was slung below all. But to trim the boat properly two passengers were needed, and de Rozier found a ready colleague in the Marquis d'Arlandes. By way of precaution, de Rozier made a few preliminary ascents with the balloon held captive, and then the two intrepid Frenchmen took their stand on opposite sides of the gallery, each furnished with bundles of fuel to feed the furnace, each also carrying a large wet sponge with which to extinguish the flames whenever the machine might catch fire. On casting off the balloon rose readily, and reaching 3,000 feet, drifted away on an upper current. The rest of the narrative, much condensed from a letter of the Marquis, written a week later, runs somewhat thus: "Our departure was at fifty-four minutes past one, and occasioned little stir among the spectators. Thinking they might be frightened and stand in need of encouragement, I waved my arm. M. de Rozier cried, 'You are doing nothing, and we are not rising!' I stirred the fire, and then began to scan the river, but Pilitre cried again, 'See the river; we are dropping into it!' We again urged the fire, but still clung to the river bed. Presently I heard a noise in the upper part of the balloon, which gave a shock as though it had burst. I called to my companion, 'Are you dancing?' The balloon by now had many holes burned in it, and using my sponge I cried that we must descend. My companion, however, explained that we were over Paris, and must now cross it. Therefore, raising the fire once more, we turned south till we passed the Luxemburg, when, extinguishing the flame, the balloon came down spent and empty." Daring as was this ascent, it was in achievement eclipsed two months later at Lyons, when a mammoth balloon, 130 feet in height and lifting 18 tons, was inflated in seventeen minutes, and ascended with no less than seven passengers. When more than half a mile aloft this machine, which was made of too slender material for its huge size, suddenly developed a rent of half its length, causing it to descend with immense velocity; but without the smallest injury to any of the passengers. This was a memorable performance, and the account, sensational as it may read, is by no means unworthy of credit; for, as will be seen hereafter, a balloon even when burst or badly torn in midair may, on the principle of the parachute, effect its own salvation. In the meanwhile, the rival balloon of hydrogen gas--the Charliere, as it has been called--had had its first innings. Before the close of the year MM. Roberts and Charles constructed and inflated a hydrogen balloon, this time fitted with a practicable valve, and in partnership accomplished an ascent beating all previous records. The day, December 17, was one of winter temperature; yet the aeronauts quickly reached 6,000 feet, and when, after remaining aloft for one and a half hours, they descended, Roberts got out, leaving Charles in sole possession. Left to himself, this young recruit seems to have met with experiences which are certainly unusual, and which must be attributed largely to the novelty of his situation. He declared that at 9,000 feet, or less than two miles, all objects on the earth had disappeared from view, a statement which can only be taken to mean that he had entered cloud. Further, at this moderate elevation he not only became benumbed with cold, but felt severe pain in his right ear and jaw. He held on, however, ascending till 10,500 feet were reached, when he descended, having made a journey of thirty miles from the start. Ascents, all on the Continent, now followed one another in rapid succession, and shortly the MM. Roberts essayed a venture on new lines. They attempted the guidance of a balloon by means of oars, and though they failed in this they were fortunate in making a fresh record. They also encountered a thunderstorm, and by adopting a perfectly scientific method--of which more hereafter--succeeded in eluding it. The storm broke around them when they were 14,000 feet high, and at this altitude, noting that there were diverse currents aloft, they managed to manoeuvre their balloon higher or lower at will and to suit their purpose, and by this stratagem drew away from the storm centre. After six and a half hours their voyage ended, but not until 150 miles had been covered. It must be freely granted that prodigious progress had been made in an art that as yet was little more than a year old; but assuredly not enough to justify the absurdly inflated ideas that the Continental public now began to indulge in. Men lost their mental balance, allowing their imagination to run riot, and speculation became extravagant in the extreme. There was to be no limit henceforward to the attainment of fresh knowledge, nor any bounds placed to where man might roam. The universe was open to him: he might voyage if he willed to the moon or elsewhere: Paris was to be the starting point for other worlds: Heaven itself had been taken by storm. Moderation had to be learned ere long by the discipline of more than one stern lesson. Hitherto a marvellous--call it a Providential--good fortune had attended the first aerial travellers; and even when mishaps presently came to be reckoned with, it may fairly be questioned whether so many lives were sacrificed among those who sought to voyage through the sky as were lost among such as first attempted to navigate the sea. It is in such ventures as we are now regarding that fortune seems readiest to favour the daring, and if I may digress briefly to adduce experiences coming within my own knowledge, I would say that it is to his very impulsiveness that the enthusiast often owes the safety of his neck. It is the timid, not the bold rider, that comes to grief at the fence. It is the man who draws back who is knocked over by a tramcar. Sheer impetus, moral or physical, often carries you through, as in the case of a fall from horse-back. To tumble off when your horse is standing still and receive a dead blow from the ground might easily break a limb. But at full gallop immunity often lies in the fact that you strike the earth at an angle, and being carried forward, impact is less abrupt. I can only say that I have on more than one occasion found the greatest safety in a balloon venture involving the element of risk to lie in complete abandonment to circumstances, and in the increased life and activity which the delirium of excitement calls forth. In comparing, however, man's first ventures by sky with those by sea, we must remember what far greater demand the former must have made upon the spirit of enterprise and daring. We can picture the earliest sea voyager taking his first lesson astride of a log with one foot on the bottom, and thus proceeding by sure stages till he had built his coracle and learned to paddle it in shoal water. But the case was wholly different when the first frail air ship stood at her moorings with straining gear and fiercely burning furnace, and when the sky sailor knew that no course was left him but to dive boldly up into an element whence there was no stepping back, and separated from earth by a gulf which man instinctively dreads to look down upon. Taking events in their due sequence, we have now to record a voyage which the terrors of sky and sea together combined to make memorable. Winter had come--early January of 1785--when, in spite of short dark days and frosty air, M. Blanchard, accompanied by an American, Dr. Jeffries, determined on an attempt to cross the Channel. They chose the English side, and inflating their balloon with hydrogen at Dover, boldly cast off, and immediately drifted out to sea. Probably they had not paid due thought to the effect of low sun and chilly atmosphere, for their balloon rose sluggishly and began settling down ere little more than a quarter of their course was run. Thereupon they parted with a large portion of their ballast, with the result that they crept on as far as mid-Channel, when they began descending again, and cast out the residue of their sand, together with some books, and this, too, with the uncomfortable feeling that even these measures would not suffice to secure their safety. This was in reality the first time that a sea passage had been made by sky, and the gravity of their situation must not be under-estimated. We are so accustomed in a sea passage to the constant passing of other vessels that we allow ourselves to imagine that a frequented portion of the ocean, such as the Channel, is thickly dotted over with shipping of some sort. But in entertaining this idea we are forgetful of the fact that we are all the while on a steamer track. The truth, however, is that anywhere outside such a track, even from the commanding point of view of a high-flying balloon, the ocean is seen to be more vast than we suppose, and bears exceedingly little but the restless waves upon its surface. Once fairly in the water with a fallen balloon, there is clearly no rising again, and the life of the balloon in this its wrong element is not likely to be a long one. The globe of gas may under favourable circumstances continue to float for some while, but the open wicker car is the worst possible boat for the luckless voyagers, while to leave it and cling to the rigging is but a forlorn hope, owing to the mass of netting which surrounds the silk, and which would prove a death-trap in the water. There are many instances of lives having been lost in such a dilemma, even when help was near at hand. Our voyagers, whom we left in mid-air and stream, were soon descending again, and this time they threw out their tackle--anchor, ropes, and other gear, still without adequately mending matters. Then their case grew desperate. The French coast was, indeed, well in sight, but there seemed but slender chance of reaching it, when they began divesting themselves of clothing as a last resort. The upshot of this was remarkable, and deserves a moment's consideration. When a balloon has been lightened almost to the utmost the discharge of a small weight sometimes has a magical effect, as is not difficult to understand. Throwing out ten pounds at an early stage, when there may be five hundred pounds more of superfluous weight, will tell but little, but when those five hundred pounds are expended then an extra ten pounds scraped together from somewhere and cast overboard may cause a balloon to make a giant stride into space by way of final effort; and it was so with M. Blanchard. His expiring balloon shot up and over the approaching land, and came safely to earth near the Forest of Guiennes. A magnificent feast was held at Calais to celebrate the above event. M. Blanchard was presented with the freedom of the city in a gold box, and application was made to the Ministry to have the balloon purchased and deposited as a memorial in the church. On the testimony of the grandson of Dr. Jeffries the car of this balloon is now in the museum of the same city. A very noteworthy example of how a balloon may be made to take a fresh lease of life is supplied by a voyage of M. Testu about this date, which must find brief mention in these pages. In one aspect it is laughable, in another it is sublime. From every point of view it is romantic. It was four o'clock on a threatening day in June when the solitary aeronaut took flight from Paris in a small hydrogen balloon only partially filled, but rigged with some contrivance of wings which were designed to render it self-propelling. Discovering, however, that this device was inoperative, M. Testu, after about an hour and a half, allowed the balloon to descend to earth in a corn field, when, without quitting hold of the car, he commenced collecting stones for ballast. But as yet he knew not the ways of churlish proprietors of land, and in consequence was presently surprised by a troublesome crowd, who proceeded, as they supposed, to take him prisoner till he should pay heavy compensation, dragging him off to the nearest village by the trail rope of his balloon. M. Testu now had leisure to consider his situation, and presently hit on a stratagem the like of which has often since been adopted by aeronauts in like predicament. Representing to his captors that without his wings he would be powerless, he suffered them to remove these weighty appendages, when also dropping a heavy cloak, he suddenly cut the cord by which he was being dragged, and, regaining freedom, soared away into the sky. He was quickly high aloft, and heard thunder below him, soon after which, the chill of evening beginning to bring him earthward, he descried a hunt in full cry, and succeeded in coming down near the huntsmen, some of whom galloped up to him, and for their benefit he ascended again, passing this time into dense cloud with thunder and lightning. He saw the sun go down and the lightning gather round, yet with admirable courage he lived the night out aloft till the storms were spent and the midsummer sun rose once more. With daylight restored, his journey ended at a spot over sixty miles from Paris. We have, of course, recounted only a few of the more noteworthy early ballooning ventures. In reality there had up to the present time been scores of ascents made in different localities and in all conditions of wind and weather, yet not a life had been lost. We have now, however, to record a casualty which cost the first and boldest aeronaut his life, and which is all the more regrettable as being due to circumstances that should never have occurred. M. Pilatre de Rosier, accompanied by M. Romain, determined on crossing the Channel from the French side; and, thinking to add to their buoyancy and avoid the risk of falling in the sea, hit on the extraordinary idea of using a fire balloon beneath another filled with hydrogen gas! With this deadly compound machine they actually ascended from Boulogne, and had not left the land when the inevitable catastrophe took place. The balloons caught fire and blew up at a height of 3,000 feet, while the unfortunate voyagers were dashed to atoms. CHAPTER III. THE FIRST BALLOON ASCENT IN ENGLAND. As may be supposed, it was not long before the balloon was introduced into England. Indeed, the first successful ascent on record made in our own country took place in the summer of 1784, ten months previous to the fatal venture narrated at the close of the last chapter. Now, it is a remarkable and equally regrettable circumstance that though the first ascent on British soil was undoubtedly made by one of our own countrymen, the fact is almost universally forgotten, or ignored, and the credit is accorded to a foreigner. Let us in strict honesty examine into the case. Vincent Lunardi, an Italian, Secretary to the Neapolitan Ambassador, Prince Caramanico, being in England in the year 1784, determined on organising and personally executing an ascent from London; and his splendid enterprise, which was presently carried to a successful issue, will form the principal subject of the present chapter. It will be seen that remarkable success crowned his efforts, and that his first and ever memorable voyage was carried through on September 15th of that year. More than a month previously, however, attention had been called to the fact that a Mr. Tytler was preparing to make an ascent from Edinburgh in a hot air balloon, and in the London Chronicle of August 27th occurs the following circumstantial and remarkable letter from a correspondent to that journal: "Edinburgh, Aug. 27, 1784. "Mr. Tytler has made several improvements upon his fire balloon. The reason of its failure formerly was its being made of porous linen, through which the air made its escape. To remedy this defect, Mr. Tytler has got it covered with a varnish to retain the inflammable air after the balloon is filled. "Early this morning this bold adventurer took his first aerial flight. The balloon being filled at Comely Garden, he seated himself in the basket, and the ropes being cut he ascended very high and descended quite gradually on the road to Restalrig, about half a mile from the place where he rose, to the great satisfaction of those spectators who were present. Mr. Tytler went up without the furnace this morning; when that is added he will be able to feed the balloon with inflammable air, and continue his aerial excursions as long as he chooses. "Mr. Tytler is now in high spirits, and in his turn laughs at those infidels who ridiculed his scheme as visionary and impracticable. Mr. Tytler is the first person in Great Britain who has navigated the air." Referring to this exploit, Tytler, in a laudatory epistle addressed to Lunardi, tells of the difficulties he had had to contend with, and artlessly reveals the cool, confident courage he must have displayed. No shelter being available for the inflation, and a strong wind blowing, his first misfortune was the setting fire to his wicker gallery. The next was the capsizing and damaging of his balloon, which he had lined with paper. He now substituted a coat of varnish for the paper, and his gallery being destroyed, so that he could no longer attempt to take up a stove, he resolved to ascend without one. In the end the balloon was successfully inflated, when he had the hardihood to entrust himself to a small basket (used for carrying earthenware) slung below, and thus to launch himself into the sky. He did so under the conviction that the risk he ran was greater than it really was, for he argued that his craft was now only like a projectile, and "must undoubtedly come to the ground with the same velocity with which it ascended." On this occasion the crowd tried for some time to hold him near the ground by one of the restraining ropes, so that his flight was curtailed. In a second experiment, however, he succeeded in rising some hundreds of feet, and came to earth without mishap. But little further information respecting Mr. Tytler is apparently forthcoming, and therefore beyond recording the fact that he was the first British aeronaut, and also that he was the first to achieve a balloon ascent in Great Britain, we are unable to make further mention of him in this history. Of his illustrious contemporary already mentioned there is, on the contrary, much to record, and we would desire to give full credit to his admirable courage and perseverance. It was with a certain national and pardonable pride that the young Italian planned his bold exploit, feeling with a sense of self-satisfaction, which he is at no pains to hide, that he aimed at winning honour for his country as well as for himself. In a letter which he wrote to his guardian, Chevalier Gherardo Compagni, he alludes to the stolid indifference of the English people and philosophers to the brilliant achievements in aeronautics which had been made and so much belauded on the Continent. He proclaims the rivalry as regards science and art existing between France and England, attributing to the latter an attitude of sullen jealousy. At the same time he is fully alive to the necessity of gaining English patronage, and sets about securing this with tactful diplomacy. First he casts about for a suitable spot where his enterprise would not fail to enlist general attention and perhaps powerful patrons, and here he is struck by the attractions and facilities offered by Chelsea Hospital. He therefore applies to Sir George Howard, the Governor, asking for the use of the famous hospital, to which, on the occasion of his experiments, he desires that admittance should only be granted to subscribers, while any profits should be devoted to the pensioners of the hospital. His application having been granted, he assures his guardian that he "still maintains his mental balance, and his sleep is not banished by the magnitude of his enterprise, which is destined to lead him through the path of danger to glory." This letter was dated the 15th of July, and by the beginning of August his advertisement was already before the public, inviting subscribers and announcing a private view of his balloon at the Lyceum, where it was in course of construction, and was being fitted with contrivances of his own in the shape of oars and sails. He had by this time not only enlisted the interest of Sir George Howard, and of Sir Joseph Banks, but had secured the direct patronage of the King. But within a fortnight a most unforeseen mishap had occurred, which threatened to overwhelm Lunardi in disappointment and ruin. A Frenchman of the name of Moret, designing to turn to his own advertisement the attention attracted by Lunardi's approaching trials, attempted to forestall the event by an enterprise of his own, announcing that he would make an ascent with a hot air balloon in some gardens near Chelsea Hospital, and at a date previous to that fixed upon by Lunardi. In attempting, however, to carry out this unworthy project the adventurer met with the discomfiture he deserved. He failed to effect his inflation, and when after fruitless attempts continued for three hours, his balloon refused to rise, a large crowd, estimated at 60,000, assembled outside, broke into the enclosure, committing havoc on all sides, not unattended with acts of violence and robbery. The whole neighbourhood became alarmed, and it followed as a matter of course that Lunardi was peremptorily ordered to discontinue his preparations, and to announce in the public press that his ascent from Chelsea Hospital was forbidden. Failure and ruin now stared the young enthusiast in the face, and it was simply the generous feeling of the British public, and the desire to see fair play, that gave him another chance. As it was, he became the hero of the hour; thousands flocked to the show rooms at the Lyceum, and he shortly obtained fresh grounds, together with needful protection for his project, at the hands of the Hon. Artillery Company. By the 15th of September all incidental difficulties, the mere enumeration of which would unduly swell these pages, had been overcome by sheer persistence, and Lunardi stood in the enclosure allotted him, his preparations in due order, with 150,000 souls, who had formed for hours a dense mass of spectators, watching intently and now confidently the issue of his bold endeavour. But his anxieties were as yet far from over, for a London crowd had never yet witnessed a balloon ascent, while but a month ago they had seen and wreaked their wrath upon the failure of an adventurer. They were not likely to be more tolerant now. And when the advertised hour for departure had arrived, and the balloon remained inadequately inflated, matters began to take a more serious turn. Half an hour later they approached a crisis, when it began to be known that the balloon still lacked buoyancy, and that the supply of gas was manifestly insufficient. The impatience of the mob indeed was kept in restraint by one man alone. This man was the Prince of Wales who, refusing to join the company within the building and careless of the attitude of the crowd, remained near the balloon to check disorder and unfair treatment. But an hour after time the balloon still rested inert and then, with fine resolution, Lunardi tried one last expedient. He bade his colleague, Mr. Biggen, who was to have ascended with him, remain behind, and quietly substituting a smaller and lighter wicker car, or rather gallery, took his place within and severed the cords just as the last gun fired. The Prince of Wales raised his hat, imitated at once by all the bystanders, and the first balloon that ever quitted English soil rose into the air amid the extravagant enthusiasm of the multitude. The intrepid aeronaut, pardonably excited, and fearful lest he should not be seen within the gallery, made frantic efforts to attract attention by waving his flag, and worked his oars so vigorously that one of them broke and fell. A pigeon also gained its freedom and escaped. The voyager, however, still retained companions in his venture--a dog and a cat. Following his own account, Lunardi's first act on finding himself fairly above the town was to fortify himself with some glasses of wine, and to devour the leg of a chicken. He describes the city as a vast beehive, St. Paul's and other churches standing out prominently; the streets shrunk to lines, and all humanity apparently transfixed and watching him. A little later he is equally struck with the view of the open country, and his ecstasy is pardonable in a novice. The verdant pastures eclipsed the visions of his own lands. The precision of boundaries impressed him with a sense of law and order, and of good administration in the country where he was a sojourner. By this time he found his balloon, which had been only two-thirds full at starting, to be so distended that he was obliged to untie the mouth to release the strain. He also found that the condensed moisture round the neck had frozen. These two statements point to his having reached a considerable altitude, which is intelligible enough. It is, however, difficult to believe his further assertion that by the use of his single oar he succeeded in working himself down to within a few hundred feet of the earth. The descent of the balloon must, in point of fact, have been due to a copious outrush of gas at his former altitude. Had his oar really been effective in working the balloon down it would not have needed the discharge of ballast presently spoken of to cause it to reascend. Anyhow, he found himself sufficiently near the earth to land a passenger who was anxious to get out. His cat had not been comfortable in the cold upper regions, and now at its urgent appeal was deposited in a corn field, which was the point of first contact with the earth. It was carefully received by a country-woman, who promptly sold it to a gentleman on the other side of the hedge, who had been pursuing the balloon. The first ascent of a balloon in England was deserving of some record, and an account alike circumstantial and picturesque is forthcoming. The novel and astonishing sight was witnessed by a Hertfordshire farmer, whose testimony, published by Lunardi in the same year, runs as follows:-- This deponent on his oath sayeth that, being on Wednesday, the 15th day of September instant, between the hours of three and four in the afternoon, in a certain field called Etna, in the parish of North Mimms aforesaid, he perceived a large machine sailing in the air, near the place where he was on horseback; that the machine continuing to approach the earth, the part of it in which this deponent perceived a gentleman standing came to the ground and dragged a short way on the ground in a slanting direction; that the time when this machine thus touched the earth was, as near as this deponent could judge, about a quarter before four in the afternoon. That this deponent being on horseback, and his horse restive, he could not approach nearer to the machine than about four poles, but that he could plainly perceive therein gentleman dressed in light coloured cloaths, holding in his hand a trumpet, which had the appearance of silver or bright tin. That by this time several harvest men coming up from the other part of the field, to the number of twelve men and thirteen women, this deponent called to them to endeavour to stop the machine, which the men attempted, but the gentleman in the machine desiring them to desist, and the machine moving with considerable rapidity, and clearing the earth, went off in a north direction and continued in sight at a very great height for near an hour afterwards. And this deponent further saith that the part of the machine in the which the gentleman stood did not actually touch the ground for more than half a minute, during which time the gentleman threw out a parcel of what appeared to this deponent as dry sand. That after the machine had ascended again from the earth this deponent perceived a grapple with four hooks, which hung from the bottom of the machine, dragging along the ground, which carried up with it into the air a small parcel of loose oats, which the women were raking in the field. And this deponent further on his oath sayeth that when the machine had risen clear from the ground about twenty yards the gentleman spoke to this deponent and to the rest of the people with his trumpet, wishing them goodbye and saying that he should soon go out of sight. And this deponent further on his oath sayeth that the machine in which the gentleman came down to earth appeared to consist of two distinct parts connected together by ropes, namely that in which the gentleman appeared to be, a stage boarded at the bottom, and covered with netting and ropes on the sides about four feet and a half high, and the other part of the machine appeared in the shape of an urn, about thirty feet high and of about the same diameter, made of canvas like oil skin, with green, red, and yellow stripes. NATHANIEL WHITBREAD. Sworn before me this twentieth day of September, 1784, WILLIAM BAKER. It was a curious fact, pointed out to the brave Italian by a resident, that the field in which the temporary descent had been made was called indifferently Etna or Italy, "from the circumstance which attended the late enclosure of a large quantity of roots, rubbish, etc., having been collected there, and having continued burning for many days. The common people having heard of a burning mountain in Italy gave the field that name." But the voyage did not end at Etna. The, as yet, inexperienced aeronaut now cast out all available ballast in the shape of sand, as also his provisions, and rising with great speed, soon reached a greater altitude than before, which he sought to still farther increase by throwing down his plates, knives, and forks. In this somewhat reckless expenditure he thought himself justified by the reliance he placed on his oar, and it is not surprising that in the end he owns that he owed his safety in his final descent to his good fortune. The narrative condensed concludes thus:-- "At twenty minutes past four I descended in a meadow near Ware. Some labourers were at work in it. I requested their assistance, but they exclaimed they would have nothing to do with one who came on the Devil's Horse, and no entreaties could prevail on them to approach me. I at last owed my deliverance to a young woman in the field who took hold of a cord I had thrown out, and, calling to the men, they yielded that assistance at her request which they had refused to mine." As may be supposed, Lunardi's return to London resembled a royal progress. Indeed, he was welcomed as a conqueror to whom the whole town sought to do honour, and perhaps his greatest gratification came by way of the accounts he gathered of incidents which occurred during his eventful voyage. At a dinner at which he was being entertained by the Lord Mayor and judges he learned that a lady seeing his falling oar, and fancying that he himself was dashed to pieces, received a shock thereby which caused her death. Commenting on this, one of the judges bade him be reassured, inasmuch as he had, as if by compensation, saved the life of a young man who might live to be reformed. The young man was a criminal whose condemnation was regarded as certain at the hands of the jury before whom he was being arraigned, when tidings reached the court that Lunardi's balloon was in the air. On this so much confusion arose that the jury were unable to give due deliberation to the case, and, fearing to miss the great sight, actually agreed to acquit the prisoner, that they themselves might be free to leave the court! But he was flattered by a compliment of a yet higher order. He was told that while he hovered over London the King was in conference with his principal Ministers, and his Majesty, learning that he was in the sky, is reported to have said to his councillors, "We may resume our own deliberations at pleasure, but we may never see poor Lunardi again!" On this, it is further stated that the conference broke up, and the King, attended by Mr. Pitt and other chief officers of State, continued to view Lunardi through telescopes as long as he remained in the horizon. The public Press, notably the Morning Post of September 16, paid a worthy tribute to the hero of the hour, and one last act of an exceptional character was carried out in his honour, and remains in evidence to this hour. In a meadow in the parish of Standon, near Ware, there stands a rough hewn stone, now protected by an iron rail. It marks the spot where Lunardi landed, and on it is cut a legend which runs thus: Let Posterity know And knowing be astonished that On the 15th day of September 1784 Vincent Lunardi of Lusca in Tuscany The first aerial traveller in Britain Mounting from the Artillery Ground In London And Traversing the Regions of the Air For Two Hours and Fifteen Minutes In this Spot Revisited the Earth. On this rude monument For ages be recorded That Wondrous Enterprise Successfully atchieved By the Powers of Chemistry And the Fortitude of Man That Improvement in Science Which The Great Author of all Knowledge Patronyzing by His Providence The Invention of Mankind Hath graciously permitted To Their Benefit And His own Eternal Glory. CHAPTER IV. THE DEVELOPMENT OF BALLOON PHILOSOPHY. In less than two years not only had the science of ballooning reached almost its highest development, but the balloon itself, as an aerostatic machine, had been brought to a state of perfection which has been but little improved upon up to the present hour. Better or cheaper methods of inflation were yet to be discovered, lighter and more suitable material remained to be manufactured; but the navigation of the air, which hitherto through all time had been beyond man's grasp, had been attained, as it were, at a bound, and at the hands of many different and independent experimentalists was being pursued with almost the same degree of success and safety as to-day. Nor was this all. There was yet another triumph of the aeronautical art which, within the same brief period, had been to all intents and purposes achieved, even if it had not been brought to the same state of perfection as at the present hour. This was the Parachute. This fact is one which for a sufficient reason is not generally known. It is very commonly supposed that the parachute, in anything like its present form, is a very modern device, and that the art of successfully using it had not been introduced to the world even so lately as thirty years ago. Thus, we find it stated in works of that date dealing with the subject that disastrous consequences almost necessarily attended the use of the parachute, "the defects of which had been attempted to be remedied in various ways, but up to this time without success." A more correct statement, however, would have been that the art of constructing and using a practicable parachute had through many years been lost or forgotten. In actual fact, it had been adopted with every assurance of complete success by the year 1785, when Blanchard by its means lowered dogs and other animals with safety from a balloon. A few years later he descended himself in a like apparatus from Basle, meeting, however, with the misadventure of a broken leg. But we must go much further back for the actual conception of the parachute, which, we might suppose, may originally have been suggested by the easy floating motion with which certain seeds or leaves will descend from lofty trees, or by the mode adopted by birds of dropping softly to earth with out-stretched wings. M. de la Loubere, in his historical account of Siam, which he visited in 1687-88, speaks of an ingenious athlete who exceedingly diverted the King and his court by leaping from a height and supporting himself in the air by two umbrellas, the handles of which were affixed to his girdle. In 1783, that is, the same year as that in which the balloon was invented, M. le Normand experimented with a like umbrella-shaped contrivance, with a view to its adoption as a fire escape, and he demonstrated the soundness of the principle by descending himself from the windows of a lofty house at Lyons. It was, however, reserved for M. Jacques Garnerin in 1797 to make the first parachute descent that attracted general attention. Garnerin had previously been detained as a State prisoner in the fortress of Bade, in Hungary, after the battle of Marchiennes in 1793, and during his confinement had pondered on the possibility of effecting his escape by a parachute. His solitary cogitations and calculations resulted, after his release, in the invention and construction of an apparatus which he put to a practical test at Paris before the court of France on October 22nd, 1797. Ascending in a hydrogen balloon to the height of about 2,000 feet, he unhesitatingly cut himself adrift, when for some distance he dropped like a stone. The folds of his apparatus, however, opening suddenly, his fall became instantly checked. The remainder of his descent, though leisurely, occupying, in fact, some twelve minutes, appeared to the spectators to be attended with uncertainty, owing to a swinging motion set up in the car to which he was clinging. But the fact remains that he reached the earth with only slight impact, and entirely without injury. It appears that Garnerin subsequently made many equally successful parachute descents in France, and during the short peace of 1802 visited London, where he gave an exhibition of his art. From the most reliable accounts of his exploit it would seem that his drop was from a very great height, and that a strong ground wind was blowing at the time, the result of which was that wild, wide oscillations were set up in the car, which narrowly escaped bringing him in contact with the house tops in St. Pancreas, and eventually swung him down into a field, not without some unpleasant scratches. Nor was Garnerin the only successful parachutist at this period. A Polish aeronaut, Jordaki Kuparento, ascended from Warsaw on the 24th of July, 1804 in a hot air balloon, taking up, as was the custom, an attached furnace, which caused the balloon to take fire when at a great height. Kuparento, however, who was alone, had as a precaution provided himself with a parachute, and with this he seems to have found no difficulty in effecting a safe descent to earth. It was many years after this that fresh experimentalists, introducing parachutes on new lines and faulty in construction, met with death or disaster. Enough, however, has already been said to show that in the early years we are now traversing in this history a perfectly practicable parachute had become an accomplished fact. The early form is well described by Mr. Monck Mason in a letter to the Morning Herald in 1837, written on the eve of an unrehearsed and fatal experiment made by Mr. Cocking, which must receive notice in due course. "The principle," writes Mr. Monck Mason, "upon which all these parachutes were constructed is the same, and consists simply of a flattened dome of silk or linen from 24 feet to 28 feet in diameter. From the outer margin all around at stated intervals proceed a large number of cords, in length about the diameter of the dome itself, which, being collected together in one point and made fast to another of superior dimensions attached to the apex of the machine, serve to maintain it in its form when expanded in the progress of the descent. To this centre cord likewise, at a distance below the point of junction, varying according to the fancy of the aeronaut, is fixed the car or basket in which he is seated, and the whole suspended from the network of the balloon in such a manner as to be capable of being detached in an instant at the will of the individual by cutting the rope by which it is made fast above." It followed almost as a matter of course that so soon as the balloon had been made subject to something like due control, and thus had become recognised as a new machine fairly reduced to the service of man, it began to be regarded as an instrument which should be made capable of being devoted to scientific research. Indeed, it may be claimed that, among the very earliest aeronauts, those who had sailed away into the skies and brought back intelligent observations or impressions of the realm of cloud-land, or who had only described their own sensations at lofty altitudes, had already contributed facts of value to science. It is time then, taking events in their due sequence, that mention should be made of the endeavours of various savants, who began about the commencement of the nineteenth century to gather fresh knowledge from the exploration of the air by balloon ascents organised with fitting equipment. The time had now come for promoting the balloon to higher purposes than those of mere exhibition or amusement. In point of fact, it had already in one way been turned to serious practical account. It had been used by the French during military operations in the revolutionary war as a mode of reconnoitring, and not without success, so that when after due trial the war balloon was judged of value a number of similar balloons were constructed for the use of the various divisions of the French army, and, as will be told in its proper place, one, at least, of these was put to a positive test before the battle of Fleurus. But, returning to more strictly scientific ascents, which began to be mooted at this period, we are at once impressed with the widespread influence which the balloon was exercising on thinking minds. We note this from the fact that what must be claimed to be the first genuine ascent for scientific observation was made in altogether fresh ground, and at so distant a spot as St. Petersburg. It was now the year 1804, and the Russian Academy had determined on attempting an examination of the physical condition of the higher atmosphere by means of the balloon. The idea had probably been suggested by scientific observations which had already been made on mountain heights by such explorers as De Luc, Saussure, Humboldt, and others. And now it was determined that their results should be tested alongside such observations as could be gathered in the free heaven far removed from any disturbing effects that might be caused by contiguity to earth. The lines of enquiry to which special attention was required were such as would be naturally suggested by the scientific knowledge of the hour, though they may read somewhat quaintly to-day. Would there be any change in the intensity of the magnetic force? Any change in the inclination of the magnetised needle? Would evaporation find a new law? Would solar rays increase in power? What amount of electric matter would be found? What change in the colours produced by the prism? What would be the constitution of the higher and more attenuated air? What physical effect would it have on human and bird life? The ascent was made at 7.15 on a summer evening by M. Robertson and the Academician, M. Sacharof, to whom we are indebted for the following resume of notes, which have a special value as being the first of their class. Rising slowly, a difference of atmosphere over the Neva gave the balloon a downward motion, necessitating the discharge of ballast. As late as 8.45 p.m. a fine view was obtained of the Newski Islands, and the whole course of the neighbouring river. At 9.20 p.m., when the barometer had fallen from 30 inches to 23 inches, a canary and a dove were dismissed, the former falling precipitately, while the latter sailed down to a village below. All available ballast was now thrown out, including a spare great coat and the remains of supper, with the result that at 9.30 the barometer had fallen to 22 inches, and at this height they caught sight of the upper rim of the sun. The action of heart and lungs remained normal. No stars were seen, though the sky was mainly clear, such clouds as were visible appearing white and at a great height. The echo of a speaking trumpet was heard after an interval of ten seconds. This was substantially the outcome of the experiments. The practical difficulties of carrying out prearranged observations amid the inconvenience of balloon travel were much felt. Their instruments were seriously damaged, and their results, despite most painstaking and praiseworthy efforts, must be regarded as somewhat disappointing. But ere the autumn of the same year two other scientific ascents, admirably schemed and financed at the public expense, had been successfully carried out at Paris in a war balloon which, as will be told, had at this time been returned from military operations in Egypt. In the first of these, Gay Lussac ascended in company with M. Biot, with very complete equipment. Choosing ten o'clock in the morning for their hour of departure, they quickly entered a region of thin, but wet fog, after which they shot up into denser cloud, which they completely surmounted at a height of 6,500 feet, when they described the upper surface as bearing the resemblance, familiar enough to aeronauts and mountaineers, as of a white sea broken up into gently swelling billows, or of an extended plain covered with snow. A series of simple experiments now embarked upon showed the behaviour of magnetised iron, as also of a galvanic pile or battery, to remain unaltered. As their altitude increased their pulses quickened, though beyond feeling keenly the contrast of a colder air and of scorching rays of the sun they experienced no physical discomfort. At 11,000 feet a linnet which they liberated fell to the earth almost helplessly, while a pigeon with difficulty maintained an irregular and precipitate flight. A carefully compiled record was made of variations of temperature and humidity, and they succeeded in determining that the upper air was charged with negative electricity. In all this these two accomplished physicists may be said to have carried out a brilliant achievement, even though their actual results may seem somewhat meagre. They not only were their own aeronauts, but succeeded in arranging and carrying out continuous and systematic observations throughout the period of their remaining in the sky. This voyage was regarded as such a pronounced success that three weeks later, in mid-September, Gay Lussac was induced to ascend again, this time alone, and under circumstances that should enable him to reach an exceptionally high altitude. Experience had taught the advisability of certain modifications in his equipment. A magnet was ingeniously slung with a view of testing its oscillation even in spite of accidental gyrations in the balloon. Thermometers and hygrometers were carefully sheltered from the direct action of the sun, and exhausted flasks were supplied with the object of bringing down samples of upper air for subsequent analysis. Again it was an early morning ascent, with a barometer on the ground standing at 30.6 inches, and a slightly misty air. Lussac appears to have accomplished the exceedingly difficult task of counting the oscillations of his magnet with satisfaction to himself. At 10,000 feet twenty vibrations occupied 83 seconds, as compared with 84.33 seconds at the earth's surface. The variation of the compass remained unaltered, as also the behaviour of magnetised iron at all altitudes. Keeping his balloon under perfect control, and maintaining a uniform and steady ascent, he at the same time succeeded in compiling an accurate table of readings recording atmospheric pressure, temperature and humidity, and it is interesting to find that he was confronted with an apparent anomaly which will commonly present itself to the aeronaut observer. Up to 12,000 feet the temperature had decreased consistently from 82 degrees to 47 degrees, after which it increased 6 degrees in the next 2,000 feet. This by no means uncommon experience shall be presently discussed. The balloon was now steadily manoeuvred up to 18,636 feet, at which height freezing point was practically reached. Then with a further climb 20,000 feet is recorded, at which altitude the ardent philosopher could still attend to his magnetic observations, nor is his arduous and unassisted task abandoned here, but with marvellous pertinacity he yet struggled upwards till a height of no less than 23,000 feet is recorded, and the thermometer had sunk to 14 degrees F. Four miles and a quarter above the level of the sea, reached by a solitary aerial explorer, whose legitimate training lay apart from aeronautics, and whose main care was the observation of the philosophical instruments he carried! The achievement of this French savant makes a brilliant record in the early pages of our history. It is not surprising that Lussac should own to having felt no inconsiderable personal discomfort before his venture was over. In spite of warm clothing he suffered greatly from cold and benumbed fingers, not less also from laboured breathing and a quickened pulse; headache supervened, and his throat became parched and unable to swallow food. In spite of all, he conducted the descent with the utmost skill, climbing down quietly and gradually till he alighted with gentle ease at St. Gourgen, near Rouen. It may be mentioned here that the analysis of the samples of air which he had brought down proved them to contain the normal proportion of oxygen, and to be essentially identical, as tested in the laboratory, with the free air secured at the surface of the earth. The sudden and apparently unaccountable variation in temperature recorded by Lussac is a striking revelation to an aerial observer, and becomes yet more marked when more sensitive instruments are used than those which were taken up on the occasion just related. It will be recorded in a future chapter how more suitable instruments came in course of time to be devised. It is only necessary to point out at this stage that instruments which lack due sensibility will unavoidably read too high in ascents, and too low in descents where, according to the general law, the air is found to grow constantly colder with elevation above the earth's surface. It is strong evidence of considerable efficiency in the instruments, and of careful attention on the part of the observer, that Lussac was able to record the temporary inversion of the law of change of temperature above-mentioned. Had he possessed modern instrumental equipment he would have brought down a yet more remarkable account of the upper regions which he visited, and learned that the variations of heat and cold were considerably more striking than he supposed. With a specially devised instrument used with special precautions, the writer, as will be shown hereafter, has been able to prove that the temperature of the air, as traversed in the wayward course of a balloon, is probably far more variable and complex than has been recorded by most observers. The exceptional height claimed to have been reached by Gay Lassac need not for a moment be questioned, and the fact that he did not experience the same personal inconvenience as has been complained of by mountain climbers at far less altitudes admits of ready explanation. The physical exertion demanded of the mountaineer is entirely absent in the case of an aeronaut who is sailing at perfect ease in a free balloon. Moreover, it must be remembered that--a most important consideration--the aerial voyager, necessarily travelling with the wind, is unconscious, save at exceptional moments, of any breeze whatever, and it is a well-established fact that a degree of cold which might be insupportable when a breeze is stirring may be but little felt in dead calm. It should also be remembered, in duly regarding Gay Lussac's remarkable record, that this was not his first experience of high altitudes, and it is an acknowledged truth that an aeronaut, especially if he be an enthusiast, quickly becomes acclimatised to his new element, and sufficiently inured to its occasional rigours. CHAPTER V. SOME FAMOUS EARLY VOYAGERS. During certain years which now follow it will possibly be thought that our history, so far as incidents of special interest are concerned, somewhat languishes. Yet it may be wrong to regard this period as one of stagnation or retrogression. Before passing on to later annals, however, we must duly chronicle certain exceptional achievements and endeavours as yet unmentioned, which stand out prominently in the period we have been regarding as also in the advancing years of the new century Among these must in justice be included those which come into the remarkable, if somewhat pathetic subsequent career of the brilliant, intrepid Lunardi. Compelling everywhere unbounded admiration he readily secured the means necessary for carrying out further exploits wherever he desired while at the same time he met with a measure of good fortune in freedom from misadventure such as has generally been denied to less bold adventurers. Within a few months of the time when we left him, the popular hero and happy recipient of civic and royal favours, we find him in Scotland attempting feats which a knowledge of practical difficulties bids us regard as extraordinary. To begin with, nothing appears more remarkable than the ease, expedition, and certainty with which in days when necessary facilities must have been far harder to come by than now, he could always fill his balloon by the usually tedious and troublesome mode attending hydrogen inflation. We see him at his first Scottish ascent, completing the operation in little more than two hours. It is the same later at Glasgow, where, commencing with only a portion of his apparatus, he finds the inflation actually to proceed too rapidly for his purpose, and has to hold the powers at his command strongly in check. Later, in December weather, having still further improved his apparatus, he makes his balloon support itself after the inflation of only ten minutes. Then, as if assured of impunity, he treats recognised risks with a species of contempt. At Kelso he hails almost with joy the fact that the wind must carry him rapidly towards the sea, which in the end he narrowly escapes. At Glasgow the chances of safe landing are still more against him, yet he has no hesitation in starting, and at last the catastrophe he seemed to court actually overtook him, and he plumped into the sea near Berwick, where no sail was even in sight, and a winter's night coming on. From this predicament he was rescued by a special providence which once before had not deserted him, when in a tumult of violent and contrary currents, and at a great height to boot, his gallery was almost completely carried away, and he had to cling on to the hoop desperately with both hands. Then we lose sight of the dauntless, light-hearted Italian for one-and-twenty years, when in the Gentleman's Magazine of July 31, 1806, appears the brief line, "Died in the convent of Barbadinas, of a decline, Mr. Vincent Lunardi, the celebrated aeronaut." Garnerin, of whom mention has already been made, accomplished in the summer of 1802 two aerial voyages marked by extreme velocity in the rate of travel. The first of these is also remarkable as having been the first to fairly cross the heart of London. Captain Snowdon, R.N., accompanied the aeronaut. The ascent took place from Chelsea Gardens, and proved so great an attraction that the crowd overflowed into the neighbouring parts of the town, choking up the thoroughfares with vehicles, and covering the river with boats. On being liberated, the balloon sped rapidly away, taking a course midway between the river and the main highway of the Strand, Fleet Street, and Cheapside, and so passed from view of the multitude. Such a departure could hardly fail to lead to subsequent adventures, and this is pithily told in a letter written by Garnerin himself: "I take the earliest opportunity of informing you that after a very pleasant journey, but after the most dangerous descent I ever made, on account of the boisterous weather and the vicinity of the sea, we alighted at the distance of four miles from this place and sixty from Ranelagh. We were only three-quarters of an hour on the way. To-night I intend to be in London with the balloon, which is torn to pieces. We ourselves are all over bruises." Only a week after the same aeronaut ascended again from Marylebone, when he attained almost the same velocity, reaching Chingford, a distance of seventeen miles, in fifteen minutes. The chief danger attending a balloon journey in a high wind, supposing no injury has been sustained in filling and launching, results not so much from impact with the ground on alighting as from the subsequent almost inevitable dragging along the ground. The grapnels, spurning the open, will often obtain no grip save in a hedge or tree, and even then large boughs will be broken through or dragged away, releasing the balloon on a fresh career which may, for a while, increase in mad impetuosity as the emptying silk offers a deeper hollow for the wind to catch. The element of risk is of another nature in the case of a night ascent, when the actual alighting ground cannot be duly chosen or foreseen. Among many record night ascents may here, somewhat by anticipation of events, be mentioned two embarked upon by the hero of our last adventure. M. Garnerin was engaged to make a spectacular ascent from Tivoli at Paris, leaving the grounds at night with attached lamps illuminating his balloon. His first essay was on a night of early August, when he ascended at 11 p.m., reaching a height of nearly three miles. Remaining aloft through the hours of darkness, he witnessed the sun rise at half-past two in the morning, and eventually came to earth after a journey of some seven hours, during which time he had covered considerably more than a hundred miles. A like bold adventure carried out from the same grounds the following month was attended with graver peril. A heavy thunderstorm appearing imminent, Garnerin elected to ascend with great rapidity, with the result that his balloon, under the diminished pressure, quickly became distended to an alarming degree, and he was reduced to the necessity of piercing a hole in the silk, while for safety's sake he endeavoured to extinguish all lamps within reach. He now lost all control over his balloon, which became unmanageable in the conflict of the storm. Having exhausted his ballast, he presently was rudely brought to earth and then borne against a mountain side, finally losing consciousness until the balloon had found anchorage three hundred miles away from Paris. A night ascent, which reads as yet more sensational and extraordinary, is reported to have been made a year or two previously, and when it is considered that the balloon used was of the Montgolfier type the account as it is handed down will be allowed to be without parallel. It runs thus: Count Zambeccari, Dr. Grassati of Rome, and M. Pascal Andreoli of Antona ascended on a November night from Bologna, allowing their balloon to rise with excessive velocity. In consequence of this rapid transition to an extreme altitude the Count and the Doctor became insensible, leaving Andreoli alone in possession of his faculties. At two o'clock in the morning they found themselves descending over the Adriatic, at which time a lantern which they carried expired and was with difficulty re-lighted. Continuing to descend, they presently pitched in to the sea and became drenched with salt water. It may seem surprising that the balloon, which could not be prevented falling in the water, is yet enabled to ascend from the grip of the waves by the mere discharge of ballast. (It would be interesting to inquire what meanwhile happened to the fire which they presumably carried with them.) They now rose into regions of cloud, where they became covered with hoar frost and also stone deaf. At 3 a.m. they were off the coast of Istria, once more battling with the waves till picked up by a shore boat. The balloon, relieved of their weight, then flew away into Turkey. However overdrawn this narrative may appear, it must be read in the light of another account, the bare, hard facts of which can admit of no question. It is five years later, and once again Count Zambeccari is ascending from Bologna, this time in company with Signor Bonagna. Again it is a Montgolfier or fire balloon, and on nearing earth it becomes entangled in a tree and catches fire. The aeronauts jump for their lives, and the Count is killed on the spot. Certainly, when every allowance is made for pardonable or unintentional exaggeration, it must be conceded that there were giants in those days. Giants in the conception and accomplishment of deeds of lofty daring. Men who came scathless through supreme danger by virtue of the calmness and courage with which they withstood it. Among other appalling disasters we have an example of a terrific descent from a vast height in which the adventurers yet escape with their lives. It was the summer of 1808, and the aeronauts, MM. Andreoli and Brioschi, ascending from Padua, reach a height at which a barometer sinks to eight inches, indicating upwards of 30,000 feet. At this point the balloon bursts, and falls precipitately near Petrarch's tomb. Commenting on this, Mr. Glaisher, the value of whose opinion is second to none, is not disposed to question the general truth of the narrative. In regard to Zambeccari's escape from the sea related above, it should be stated that in the case of a gas-inflated balloon which has no more than dipped its car or gallery in the waves, it is generally perfectly possible to raise it again from the water, provided there is on board a store of ballast, the discharge of which will sufficiently lighten the balloon. A case in point occurred in a most romantic and perilous voyage accomplished by Mr. Sadler on the 1st of October, 1812. His adventure is one of extraordinary interest, and of no little value to the practical aeronaut. The following account is condensed from Mr. Sadler's own narrative. He started from the grounds of Belvedere House, Dublin, with the expressed intention of endeavouring to cross over the Irish Channel to Liverpool. There appear to have been two principal air drifts, an upper and a lower, by means of which he entertained fair hopes of steering his desired course. But from the outset he was menaced with dangers and difficulties. Ere he had left the land he discovered a rent in his silk which, occasioned by some accident before leaving, showed signs of extending. To reach this, it was necessary to extemporise by means of a rope a species of ratlins by which he could climb the rigging. He then contrived to close the rent with his neckcloth. He was, by this time, over the sea, and, manoeuvring his craft by aid of the two currents at his disposal, he was carried to the south shore of the Isle of Man, whence he was confident of being able, had he desired it, of landing in Cumberland. This, however, being contrary to his intention, he entrusted himself to the higher current, and by it was carried to the north-west of Holyhead. Here he dropped once again to the lower current, drifting south of the Skerry Lighthouse across the Isle of Anglesea, and at 4.30 p.m. found himself abreast of the Great Orme's Head. Evening now approaching, he had determined to seek a landing, but at this critical juncture the wind shifted to the southward, and he became blown out to sea. Then, for an hour, he appears to have tried high and low for a more favourable current, but without success; and, feeling the danger of his situation, and, moreover, sighting no less than five vessels beating down the Channel, he boldly descended in the sea about a mile astern of them. He must for certain have been observed by these vessels; but each and all held on their course, and, thus deserted, the aeronaut had no choice but to discharge ballast, and, quitting the waves, to regain his legitimate element. His experiences at this period of his extraordinary voyage are best told in his own words. "At the time I descended the sun was near setting Already the shadows of evening had cast a dusky hue over the face of the ocean, and a crimson glow purpled the tops of the waves as, heaving in the evening breeze, they died away in distance, or broke in foam against the sides of the vessels, and before I rose from the sea the orb had sunk below the horizon, leaving only the twilight glimmer to light the vast expanse around me. How great, therefore, was my astonishment, and how incapable is expression to convey an adequate idea of my feelings when, rising to the upper region of the air, the sun, whose parting beams I had already witnessed, again burst on my view, and encompassed me with the full blaze of day. Beneath me hung the shadows of even, whilst the clear beams of the sun glittered on the floating vehicle which bore me along rapidly before the wind." After a while he sights three more vessels, which signify their willingness to stand by, whereupon he promptly descends, dropping beneath the two rear-most of them. From this point the narrative of the sinking man, and the gallant attempt at rescue, will rival any like tale of the sea. For the wind, now fast rising, caught the half empty balloon so soon as the car touched the sea, and the vessel astern, though in full pursuit, was wholly unable to come up. Observing this, Mr. Sadler, trusting more to the vessel ahead, dropped his grappling iron by way of drag, and shortly afterwards tried the further expedient of taking off his clothes and attaching them to the iron. The vessels, despite these endeavours, failing to overhaul him, he at last, though with reasonable reluctance, determined to further cripple the craft that bore him so rapidly by liberating a large quantity of gas, a desperate, though necessary, expedient which nearly cost him his life. For the car now instantly sank, and the unfortunate man, clutching at the hoop, found he could not even so keep himself above the water, and was reduced to clinging, as a last hope, to the netting. The result of this could be foreseen, for he was frequently plunged under water by the mere rolling of the balloon. Cold and exertion soon told on him, as he clung frantically to the valve rope, and when his strength failed him he actually risked the expedient of passing his head through the meshes of the net. It was obvious that for avail help must soon come; yet the pursuing vessel, now close, appeared to hold off, fearing to become entangled in the net, and in this desperate extremity, fainting from exhaustion and scarcely able to cry aloud, Mr. Sadler himself seems to have divined the chance yet left; for, summoning his failing strength, he shouted to the sailors to run their bowsprit through his balloon. This was done, and the drowning man was hauled on board with the life scarcely in him. A fitting sequel to the above adventure followed five years afterwards. The Irish Sea remained unconquered. No balloonist had as yet ever crossed its waters. Who would attempt the feat once more? Who more worthy than the hero's own son, Mr. Windham Sadler? This aspiring aeronaut, emulating his father's enterprising spirit, chose the same starting ground at Dublin, and on the longest day of 1817, when winds seemed favourable, left the Porto Bello barracks at 1.20 p.m. His endeavour was to "tack" his course by such currents as he should find, in the manner attempted by his father, and at starting the ground current blew favourably from the W.S.W. He, however, allowed his balloon to rise to too high an altitude, where he must have been taken aback by a contrary drift; for, on descending again through a shower of snow, he found himself no further than Ben Howth, as yet only ten miles on his long journey. Profiting by his mistake, he thenceforward, by skilful regulation, kept his balloon within due limits, and successfully maintained a direct course across the sea, reaching a spot in Wales not far from Holyhead an hour and a half before sundown. The course taken was absolutely the shortest possible, being little more than seventy miles, which he traversed in five hours. From this period of our story, noteworthy events in aeronautical history grow few and far between. As a mere exhibition the novelty of a balloon ascent had much worn off. No experimentalist was ready with any new departure in the art. No fresh adventure presented itself to the minds of the more enterprising spirits; and, whereas a few years previously ballooning exploits crowded into every summer season and were not neglected even in winter months, there is now for a while little to chronicle, either abroad or in our own country. A certain revival of the sensational element in ballooning was occasionally witnessed, and not without mishap, as in the case of Madame Blanchard, who, in the summer of 1819, ascending at night with fireworks from the Tivoli Gardens, Paris, managed to set fire to her balloon and lost her life in her terrific fall. Half a dozen years later a Mr., as also Mrs., Graham figure before the public in some bold spectacular ascents. But the fame of any aeronaut of that date must inevitably pale before the dawning light shed by two stars of the first magnitude that were arising in two opposite parts of the world--Mr. John Wise in America, and Mr. Charles Green in our own country. The latter of these, who has been well styled the "Father of English Aeronautics," now entered on a long and honoured career of so great importance and success that we must reserve for him a separate and special chapter. CHAPTER VI. CHARLES GREEN AND THE NASSAU BALLOON. The balloon, which had gradually been dropping out of favour, had now been virtually laid aside, and, to all appearance, might have continued so, when, as if by chance concurrence of events, there arrived both the hour and the man to restore it to the world, and to invest it with a new practicability and importance. The coronation of George the Fourth was at hand, and this became a befitting occasion for the rare genius mentioned at the end of the last chapter, and now in his thirty-sixth year, to put in practice a new method of balloon management and inflation, the entire credit of which must be accorded to him alone. From its very introduction and inception the gas balloon, an expensive and fragile structure in itself, had proved at all times exceedingly costly in actual use. Indeed, we find that at the date at which we have now arrived the estimate for filling a balloon of 70,000 cubic feet--no extraordinary capacity--with hydrogen gas was about L250. When, then, to this great outlay was added the difficulty and delay of producing a sufficient supply by what was at best a clumsy process, as also the positive failure and consequent disappointment which not infrequently ensued, it is easy to understand how through many years balloon ascents, no longer a novelty, had begun to be regarded with distrust, and the profession of a balloonist was doomed to become unremunerative. A simpler and cheaper mode of inflation was not only a desideratum, but an absolute necessity. The full truth of this may be gathered from the fact that we find there were not seldom instances where two or three days of continuous and anxious labour were expended in generating and passing hydrogen into a balloon, through the fabric of which the subtle gas would escape almost as fast as it was produced. It was at this juncture, then, that Charles Green conceived the happy idea of substituting for hydrogen gas the ordinary household gas, which at this time was to be found ready to hand and in sufficient quantity in all towns of any consequence; and by the day of the coronation all was in readiness for a public exhibition of this method of inflation, which was carried out with complete success, though not altogether without unrehearsed and amusing incident, as must be told. The day, July 18, was one of summer heat, and Green at the conclusion of his preparations, fatigued with anxious labour and oppressed by the crowding of the populace, took refuge within the car of his balloon, which was by that time already inflated, and only awaiting the gun signal that was to announce the moment for its departure. To allow of his gaining the refreshment of somewhat purer air he begged his friends who were holding the car of his balloon in restraint to keep it suspended at a few feet from the earth, while he rested himself within, and, this being done, it would appear that he fell into a doze, from which he did not awake till he found that the balloon, which had slipped from his friends' hold, was already high above the crowd and requiring his prompt attention. This was, however, by no means an untoward accident, and Green's triumph was complete. By this one venture alone the success of the new method was entirely assured. The cost of the inflation had been reduced ten-fold, the labour and uncertainty a hundred-fold, and, over and above all, the confidence of the public was restored. It is little wonder, then, that in the years that now follow we find the balloon returning to all the favour it had enjoyed in its palmiest days. But Green proved himself something more than a practical balloonist of the first rank. He brought to the aid of his profession ideas which were matured by due thought and scientifically sound. It is true he still clung for a while to the antiquated notion that mechanical means could, with advantage, be used to cause a balloon to ascend or descend, or to alter its direction in a tranquil atmosphere. But he saw clearly that the true method of navigating a balloon should be by a study of upper currents, and this he was able to put to practical proof on a memorable occasion, and in a striking manner, as we shall presently relate. He learned the lesson early in his career while acquiring facts and experience, unassisted, in a number of solitary voyages made from different parts of the country. Among these he is careful to record an occasion when, making a day-light ascent from Boston, Lincolnshire, he maintained a lofty course, which promised to take him direct to Grantham; but, presently descending to a lower level, and his balloon diverging at an angle of some 45 degrees, he now headed for Newark. This experience he stored away. A month later we find him making a night voyage from Vauxhall Gardens, destined to be the scene of many memorable ascents in the near future; and on this occasion he gave proof of his capability as a close and intelligent observer. It was a July night, near 11 p.m., moonless and cloudy, yet the earth was visible, and under these circumstances his simple narrative becomes of scientific value. He accurately distinguished the reflective properties of the face of the diversified country he traversed. Over Battersea and Wandsworth--this was in 1826--there were white sheets spread over the land, which proved to be corn crops ready for the sickle. Where crops were not the ground was darker, with, here and there, objects absolutely black--in other words, trees and houses. Then he mentions the river in a memorandum, which reads strangely to the aeronaut who has made the same night voyage in these latter days. The stream was crossed in places with rows of lamps apparently resting on the water. These were the lighted bridges; but, here and there, were dark planks, and these too were bridges--at Battersea and Putney--but without a light upon them! In these and many other simple, but graphic, narratives Green draws his own pictures of Nature in her quieter moods. But he was not without early experience of her horse play, a highly instructive record of which should not be omitted here, and which, as coming from so careful and conscientious an observer, is best gathered from his own words. The ascent was from Newbury, and it can have been no mean feat to fill, under ordinary circumstances, a balloon carrying two passengers and a considerable weight of ballast at the small gas-holder which served the town eighty-five years ago. But the circumstances were not ordinary, for the wind was extremely squally; a tremendous hail and thunderstorm blew up, and a hurricane swept the balloon with such force that two tons weight of iron and a hundred men scarce sufficed to hold it in check. Green on this occasion had indeed a companion, whose usefulness however at a pinch may be doubted when we learn that he was both deaf and dumb. The rest of the narrative runs thus: "Between 4 and 5 p.m. the clouds dispersed, but the wind continued to rage with unabated fury the whole of the evening. At 6 p.m. I stepped into the car with Mr. Simmons and gave the word 'Away!' The moment the machine was disencumbered of its weights it was torn by the violence of the wind from the assistants, bounded off with the velocity of lightning in a southeasterly direction, and in a very short space of time attained an elevation of two miles. At this altitude we perceived two immense bodies of clouds operated on by contrary currents of air until at length they became united, and at that moment my ears were assailed by the most awful and longest continued peal of thunder I have ever heard. These clouds were a full mile beneath us, but perceiving other strata floating at the same elevation at which we were sailing, which from their appearance I judged to be highly charged with electricity, I considered it prudent to discharge twenty pounds of ballast, and we rose half a mile above our former elevation, where I considered we were perfectly safe and beyond their influence. I observed, amongst other phenomena, that at every discharge of thunder all the detached pillars of clouds within the distance of a mile around became attracted and appeared to concentrate their force towards the first body of clouds alluded to, leaving the atmosphere clear and calm beneath and around us. "With very trifling variations we continued the same course until 7.15 p.m., when we descended to within 500 feet of the earth; but, perceiving from the disturbed surface of the rivers and lakes that a strong wind existed near the earth, we again ascended and continued our course till 7.30 p.m., when a final descent was safely effected in a meadow field in the parish of Crawley in Surrey, situated between Guildford and Horsham, and fifty-eight miles from Newbury. This stormy voyage was performed in one hour and a half." It was after Green had followed his profession for fifteen years that he was called upon to undertake the management of an aerial venture, which, all things considered, has never been surpassed in genuine enterprise and daring. The conception of the project was due to Mr. Robert Hollond, and it took shape in this way. This gentleman, fresh from Cambridge, possessed of all the ardour of early manhood, as also of adequate means, had begun to devote himself with the true zeal of the enthusiast to the pursuit of ballooning, finding due opportunity for this in his friendship with Mr. Green, who enjoyed the management of the fine balloon made for ascents at the then popular Vauxhall Gardens. In the autumn of 1836 the proprietors of this balloon, contemplating making an exhibition of an ascent from Paris, and requiring their somewhat fragile property to be conveyed to that city, Mr. Hollond boldly came forward and offered to transfer it thither, and, as nearly as this might be possible, by passage through the sky. The proposal was accepted, and Mr. Holland, in conjunction with Green, set about the needful preparations. These, as will appear, were on an extraordinary scale, and no blame is to be imputed on that account, as a little consideration will show. For the venture proposed was not to be that of merely crossing the Channel, which, as we have seen, had been successfully effected no less than fifty years before. The voyage in contemplation was to be from London; it was, moreover, to be pursued through a long, moonless winter's night, and under conditions of which no living aeronaut had had actual experience. Calculation, based on a sufficient knowledge of fast upper currents, told that their course, ere finished, might be one of almost indefinite length, and it is not too much to say that no one, with the knowledge of that day, could predict within a thousand miles where the dawn of the next day might find them. The equipment, therefore, was commensurate with the possible task before them. To begin with, they limited their number to three in all--Mr. Hollond, as chief and keeper of the log; Mr. Green, as aeronaut; and an enthusiastic colleague, Mr. Monck Mason, as the chronicler of the party. Next, they provided themselves with passports to all parts of the Continent; and then came the fitting out and victualling of the aerial craft itself, calculated to carry some 90,000 cubic feet of gas, and a counterpoise of a ton of ballast, which took the form partly of actual provisions in large quantity, partly of gear and apparatus, and for the rest of sand and also lime, of which more anon. Across the middle of the car was fixed a bench to serve as table, and also as a stage for the winding in and out of an enormous trail rope a thousand feet long, designed by Mr. Green to meet the special emergencies of the voyage. At the bottom of the car was spread a large cushion to serve the purposes of rest. When all was in readiness unfitness of weather baulked the travellers for some days, but Monday, the 7th of November, was judged a favourable day, so that the inflation was rapidly proceeded with, and at 1.30 p.m. the "Monstre Balloon," as it was entitled in the "Ingoldsby Legends," left the earth on her eventful and ever memorable voyage. The weather was fine and promising, and, rising with a moderate breeze from the N.W., they began to traverse the northern parts of Kent, while light, drifting upper clouds gave indication of other possible currents. Mr. Hollond was precise in the determination of times and of all readings and we learn that at exactly 2.48 p.m. they were crossing the Medway, six miles west of Rochester, while at 4.5 p.m. the lofty towers of Canterbury were well in view, two miles to the east, and here a little function was well carried out. Green had twice ascended from this city under patronage of the authorities, and the idea occurred to the party that it would be a graceful compliment to drop a message to the Mayor as they passed. A suitable note, therefore, quickly written, was dismissed in a parachute, and it may be mentioned that this, as also a similar missive addressed later to the Mayor of Dover, were duly received and acknowledged. At a quarter past four they sighted the sea, and here, the air beginning to grow chill, the balloon dropped earthward, and for some miles they skimmed the ground, disturbing the partridges, scattering the rooks, and keeping up a running conversation the while with labourers and passers below. In this there was exercise of perfectly proper aerial seamanship, such as moreover presently led to an exhibition of true science. To save ballast is, with a balloon, to prolong life, and this may often best be done by flying low, which doubtless was Green's present intention. But soon his trained eye saw that the ground current which now carried them was leading them astray. They were trending to the northward, and so far out of their course that they would soon make the North Foreland, and so be carried out over the North Sea far from their desired direction. Thereupon Green attempted to put in practice his theory, already spoken of, of steering by upper currents, and the event proved his judgment peculiarly correct. "Nothing," wrote Mr. Monck Mason, "could exceed the beauty of the manoeuvre, to which the balloon at once responded, regaining her due course, and, in a matter of a few minutes only, bearing the voyagers almost vertically over the castle of Dover in the exact line for crossing the straits between that town and Calais." So far all was well, and success had been extraordinary; but from this moment they became faced with new conditions, and with the grave trouble of uncertainty. Light was failing, the sea was before them, and--what else thenceforth? 4.48 p.m. was recorded as the moment when the first line of breaking waves was seen directly below them, and then the English coast line began rapidly to fade out from their view. But, ahead, the obscurity was yet more intense, for clouds, banked up like a solid wall, crowned along its frowning heights, with "parapets and turrets and batteries and bastions," and, plunging into this opposing barrier, they were quickly buried in blackness, losing at the same time over the sea all sound from earth soever. So for a short hour's space, when the sound of waves once again broke in upon them, and immediately afterwards emerging from the dense cloud (a sea-fog merely) they found themselves immediately over the brilliantly lighted town of Calais. Seeing this, the travellers attempted to signal by igniting and lowering a Bengal Light, which was directly followed by the beating of drums from below. It adds a touch of reality, as well as cheerfulness, to the narrative to read that at this period of their long journey the travellers apply themselves to a fair, square meal, the first for twelve hours, despite the day's excitement and toil. We have an entry among the stores of the balloon of wine bottles and spirit flasks, but there is no mention of these being requisitioned at this period. The demand seems rather to have been for coffee--coffee hot; and this by a novel device was soon prepared. It goes without saying that a fire or flame of any kind, except with special precautions, is inadmissable in a balloon; but a cooking heat, sufficient for the present purpose, was supplied from the store of lime, a portion of which, being placed in a suitably contrived vessel and slaked quickly, procured the desired beverage. This meal now indulged in seems to have been heartily and happily enjoyed; and from this point, for a while, the narrative becomes that of enthusiastic and delighted travellers. In the gloom below, for leagues around, they regarded the scattered fires of a watchful population, with here and there the lights of larger towns, and the contemplation begot romantic reveries. "Were they not amid the vast solitudes of the skies, in the dead of night, unknown and unnoticed, secretly and silently reviewing kingdoms, exploring territories, and surveying cities all clothed in the dark mantle of mystery?" Presently they identified the blazing city of Liege, with the lurid lights of extensive outlying iron works, and this was the last visible sign they caught of earth that night; save, at least, when occasional glimpses of lightning momentarily and dimly outlined the world in the abyss below. Ere long, they met with their first discomfort, which they seem to have regarded as a most serious one, namely, the accidental dropping overboard of their cherished coffee-boiling apparatus. With its loss their store of lime became useless, save as ballast, and for this it was forthwith utilised until nothing remained but the empty lime barrel itself, which, being regarded as an objectionable encumbrance, it was desirable to get rid of, were it not for the risk involved in rudely dropping it to earth. But the difficulty was met. They possessed a suitable small parachute, and, attached to this, the barrel was allowed to float earthward. As hours advanced, the blackness of night increased, and their impressions appear somewhat strange to anyone familiar with ordinary night travel in the sky. Mr. Monck Mason compares their progress through the darkness to "cleaving their way through an interminable mass of black marble." Then, presently, an unaccountable object puzzles and absorbs the attention of all the party for a long period. They were gazing open-mouthed at a long narrow avenue of feeble light, which, though apparently belonging to earth, was too long and regular for a river, and too broad for a canal or road, and it was only after many futile imaginings that they discovered they were simply looking at a stay rope of the balloon hanging far out over the side. Somewhat later still, there was a more serious claim upon the imagination. It was half-past three in the morning, and the balloon, which, to escape from too low an altitude, had been liberally lightened, had now at high speed mounted to a vast height. And then, amid the black darkness and dead silence of that appalling region, suddenly overhead came the sound of an explosion, followed by the violent rustling of the silk, while the car jerked violently, as though suddenly detached from its hold. This was the idea, leading to the belief that the balloon had suddenly exploded, and that they were falling headlong to earth. Their suspense, however, cannot have been long, and the incident was intelligible enough, being due to the sudden yielding of stiffened net and silk under rapid expansion caused by their speedy and lofty ascent. The chief incidents of the night were now over, until the dawn arrived and began to reveal a strange land, with large tracts of snow, giving place, as the light strengthened, to vast forests. To their minds these suggested the plains of Poland, if not the steppes of Russia, and, fearing that the country further forward might prove more inhospitable, they decided to come to earth as speedily as possible. This, in spite of difficult landing, they effected about the hour that the waking population were moving abroad, and then, and not till then, they learned the land of their haven--the heart of the German forests. Five hundred miles had been covered in eighteen hours from start to finish! CHAPTER VII. CHARLES GREEN--FURTHER ADVENTURES. All history is liable to repeat itself, and that of aeronautics forms no exception to the rule. The second year after the invention of the balloon the famous M. Blanchard, ascending from Frankfort, landed near Weilburg, and, in commemoration of the event, the flag he bore was deposited among the archives in the ducal palace of that town. Fifty-one years passed by when, outside the same city, a yet more famous balloon effected its landing, and with due ceremony its flag is presently laid beside that of Blanchard in the same ducal palace. The balloon of the "Immortal Three," whose splendid voyage has just been recounted, will ever be known by the title of the Great Nassau Balloon, but the neighbourhood of its landing was that of the town of Weilburg, in the Duchy of Nassau, whither the party betook themselves, and where, during many days, they were entertained with extravagant hospitality and honour until business recalled Mr. Hollond home. Green had now made upwards of two hundred ascents, and, though he lived to make a thousand, it was impossible that he could ever eclipse this last record. It is true that the same Nassau balloon, under his guidance, made many other most memorable voyages, some of which it will be necessary to dwell on. But, to preserve a better chronology, we must first, without further digression, approach an event which fills a dark page in our annals; and, in so doing, we have to transfer our attention from the balloon itself to its accessory, the parachute. Twenty-three years before our present date, that is to say in 1814, Mr. Cocking delivered his views as to the proper form of the parachute before the Society of Arts, who, as a mark of approval, awarded him a medal. This parachute, however, having never taken practical shape, and only existing, figuratively speaking, in the clouds, seemed unlikely to find its way there in reality until the success of the Nassau adventure stirred its inventor to strenuous efforts to give it an actual trial. Thus it came about that he obtained Mr. Green's co-operation in the attempt he now undertook, and, though this ended disastrously, for Mr. Cocking, the great professional aeronaut can in no way soever be blamed for the tragic event. The date of the trial was in July, 1837. Mr. Cocking's parachute was totally different in principle from that form which, as we have seen, had met with a fair measure of success at the hands of early experimenters; and on the eve of its trial it was strongly denounced and condemned in the London Press by the critic whom we have recently so freely quoted, Mr. Monck Mason. This able reasoner and aeronaut pointed out that the contrivance about to be tested aimed at obviating two principal drawbacks which the parachute had up to that time presented, namely (1) the length of time which elapses before it becomes sufficiently expanded, and (2) the oscillatory movement which accompanies the descent. In this new endeavour the inventor caused his machine to be fixed rigidly open, and to assume the shape of an inverted cone. In other words, instead of its being like an umbrella opened, it rather resembled an umbrella blown inside out. Taking, then, the shape and dimensions of Mr. Cocking's structure as a basis for mathematical calculation, as also its weight, which for required strength he put at 500 lbs. Mr. Monck Mason estimated that the adventurer and his machine must attain in falling a velocity of some twelve miles an hour. In fact, his positive prediction was that one of two events must inevitably take place. "Either the parachute would come to the ground with a force incompatible with the safety of the individual, or should it be attempted to make it sufficiently light to resist this conclusion, it must give way beneath the forces which will develop in the descent." This emphatic word of warning was neglected, and the result of the terrible experiment can best be gathered from two principal sources. First, that of a special reporter writing from terra-firma, and, secondly, that of Mr. Green himself, who gives his own observations as made from the balloon in which he took the unfortunate man and his invention into the sky. The journalist, who first speaks of the enormous concourse that gathered to see the ascent, not only within Vauxhall Gardens, but on every vantage ground without, proceeds to tell of his interview with Mr. Cocking himself, who, when questioned as to the danger involved, remarked that none existed for him, and that the greatest peril, if any, would attend the balloon when suddenly relieved of his weight. The proprietors of the Gardens, as the hour approached, did their best to dissuade the over-confident inventor, offering, themselves, to take the consequences of any public disappointment. This was again without avail, and so, towards 6 p.m., Mr. Green, accompanied by Mr. Spencer, a solicitor of whom this history will have more to tell, entered the balloon, which was then let up about 40 feet that the parachute might be affixed below. A little later, Mr. Cocking, casting aside his heavy coat and tossing off a glass of wine, entered his car and, amid deafening acclamations, with the band playing the National Anthem, the balloon and aeronauts above, and he himself in his parachute swinging below, mounted into the heavens, passing presently, in the gathering dusk, out of view of the Gardens. The sequel should be gathered from Mr. Green's own narrative. Previous to starting, 650 lbs. of ballast had to be discarded to gain buoyancy sufficient to raise the massive machine. This, together with another 100 lbs., which was also required to be ejected owing to the cooling of the air, was passed out through a canvas tube leading downwards through a hole in the parachute, an ingenious contrivance which would prevent the sand thrown out from the balloon falling on the slender structure itself. On quitting the earth, however, this latter set up such violent oscillations that the canvas tube was torn away, and then it became the troublesome task of the aeronauts to make up their ballast into little parcels, and, as occasion required, to throw these into space clear of the swinging parachute below. Despite all efforts, however, it was soon evident that the cumbersome nature of the huge parachute would prevent its being carried up quite so high as the inventor desired. Mr. Cocking had stipulated for an elevation of 7,000 feet, and, as things were, only 5,000 feet could be reached, at any rate, before darkness set in. This fact was communicated to Mr. Cocking, who promptly intimated his intention of leaving, only requesting to know whereabouts he was, to which query Mr. Spencer replied that they were on a level with Greenwich. The brief colloquy that ensued is thus given by Mr. Green:-- "I asked him if he felt quite comfortable, and if the practical trial bore out his calculation. Mr. Cocking replied, 'Yes, I never felt more comfortable or more delighted in my life,' presently adding, 'Well, now I think I shall leave you.' I answered, 'I wish you a very "Good Night!" and a safe descent if you are determined to make it and not use the tackle' (a contrivance for enabling him to retreat up into the balloon if he desired). Mr. Cocking's only reply was, 'Good-night, Spencer; Good-night, Green!' Mr. Cocking then pulled the rope that was to liberate himself, but too feebly, and a moment afterwards more violently, and in an instant the balloon shot upwards with the velocity of a sky rocket. The effect upon us at this moment was almost beyond description. The immense machine which suspended us between heaven and earth, whilst it appeared to be forced upwards with terrific violence and rapidity through unknown and untravelled regions amidst the howlings of a fearful hurricane, rolled about as though revelling in a freedom for which it had long struggled, but of which until that moment it had been kept in utter ignorance. It, at length, as if somewhat fatigued by its exertions, gradually assumed the motions of a snake working its way with extraordinary speed towards a given object. During this frightful operation the gas was rushing in torrents from the upper and lower valve, but more particularly from the latter, as the density of the atmosphere through which we were forcing our progress pressed so heavily on the valve at the top of the balloon as to admit of but a comparatively small escape by this aperture. At this juncture, had it not been for the application to our mouths of two pipes leading into an air bag, with which we had furnished ourselves previous to starting, we must within a minute have been suffocated, and so, but by different means, have shared the melancholy fate of our friend. This bag was formed of silk, sufficiently capacious to contain 100 gallons of atmospheric air. Prior to our ascent, the bag was inflated with the assistance of a pair of bellows with fifty gallons of air, so allowing for any expansion which might be produced in the upper regions. Into the end of this bag were introduced two flexible tubes, and the moment we felt ourselves to be going up in the manner just described, Mr. Spencer, as well as myself, placed either of them in our mouths. By this simple contrivance we preserved ourselves from instantaneous suffocation, a result which must have ensued from the apparently endless volume of gas with which the car was enveloped. The gas, notwithstanding all our precautions, from the violence of its operation on the human frame, almost immediately deprived us of sight, and we were both, as far as our visionary powers were concerned, in a state of total darkness for four or five minutes." Messrs. Green and Spencer eventually reached earth in safety near Maidstone, knowing nothing of the fate of their late companion. But of this we are sufficiently informed through a Mr. R. Underwood, who was on horseback near Blackheath and watching the aeronauts at the moment when the parachute was separated from the balloon. He noticed that the former descended with the utmost rapidity, at the same time swaying fearfully from side to side, until the basket and its occupant, actually parting from the parachute, fell together to earth through several hundred feet and were dashed to pieces. It would appear that the liberation of the parachute from below the balloon had been carried out without hitch; indeed, all so far had worked well, and the wind at the time was but a gentle breeze. The misadventure, therefore, must be entirely attributed to the faulty manner in which the parachute was constructed. There could, of course, be only one issue to the sheer drop from such a height, which became the unfortunate Mr. Cocking's fate, but the very interesting question will have to be discussed as to the chances in favour of the aeronaut who, within his wicker car, while still duly attached to the balloon, may meet with a precipitate descent. We may here fitly mention an early perilous experience of Mr. Green, due simply to the malice of someone never discovered. It appears that while Green's balloon, previous to an ascent, was on the ground, the cords attaching the car had been partly severed in such a way as to escape detection. So that as soon as the balloon rose the car commenced breaking away, and its occupants, Mr. Green and Mr. Griffiths, had to clutch at the ring, to which with difficulty they continued to cling. Meanwhile, the car remaining suspended by one cord only, the balloon was caused to hang awry, with the result that its upper netting began giving way, allowing the balloon proper gradually to escape through the bursting meshes, thus threatening the distracted voyagers with terrible disaster. The disaster, in fact, actually came to pass ere the party completed their descent, "the balloon, rushing through the opening in the net-work with a tremendous explosion, and the two passengers clinging to the rest of the gear, falling through a height said to be near a hundred feet. Both, though only with much time and difficulty, recovered from the shock." In 1840, three years after the tragic adventure connected with Mr. Cocking's parachute trial, we find Charles Green giving his views as to the practicability of carrying out a ballooning enterprise which should far excel all others that had hitherto been attempted. This was nothing less than the crossing of the Atlantic from America to England. There is no shadow of doubt that the adventurous aeronaut was wholly in earnest in the readiness he expressed to embark on the undertaking should adequate funds be forthcoming; and he discusses the possibilities with singular clearness and candour. He maintains that the actual difficulties resolve themselves into two only: first, the maintenance of the balloon in the sky for the requisite period of time; and, secondly, the adequate control of its direction in space. With respect to the first difficulty, he points out the fact to which we have already referred, namely, that it is impossible to avoid the fluctuations of level in a balloon's course, "by which it constantly becomes alternately subjected to escape of gas by expansion, and consequent loss of ballast, to furnish an equivalent diminution of weight." Taking his own balloon of 80,000 cubic feet by way of example, he shows that this, fully inflated on the earth, would lose 8,000 cubic feet of gas by expansion in ascending only 3,000 feet. Moreover, the approach of night or passage through cloud or falling rain would occasion chilling of the gas or accumulation of moisture on the silk, in either case necessitating the loss of ballast, the store of which is always the true measure of the balloon's life. To combat the above difficulty Green sanguinely relies on his favourite device of a trail or guide rope, whose function, being that of relieving the balloon of a material weight as it approaches the earth, could, he supposed, be made to act yet more efficiently when over the sea in the following manner. Its length, suspended from the ring, being not less than 2,000 feet, it should have attached at its lower end at certain intervals a number of small, stout waterproof canvas bags, the apertures of which should be contrived to admit water, but to oppose its return. Between these bags were to be conical floats, to support any length of the rope that might descend on the sea. Now, should the balloon commence descending, it would simply deposit a certain portion of rope on the water until it regained equilibrium at no great decrease of altitude, and would thus continue its course until alteration of conditions should cause it to recommence rising, when the weight of water now collected in the bags would play its part in preventing the balloon from soaring up into space. With such a contrivance Green allowed himself to imagine that he could keep a properly made balloon at practically the same altitude for a period of three months if required. The difficulty of maintaining a due course was next discussed, and somewhat speedily disposed of. Here Green relied on the results of his own observation, gathered during 275 ascents, and stated his conviction that there prevails a uniformity of upper wind currents that would enable him to carry out his bold projects successfully. His contention is best given in his own words: "Under whatever circumstances," he says, "I made my ascent, however contrary the direction of the winds below, I uniformly found that at a certain elevation, varying occasionally, but always within 10,000 feet of the earth, a current from the west or rather from the north of west, invariably travailed, nor do I recollect a single instance in which a different result ensued." Green's complete scheme is now sufficiently evident. He was to cross the Atlantic practically by the sole assistance of upper currents and his guide rope, but on this latter expedient, should adverse conditions prevail, he yet further relied, for he conceived that the rope could have attached to its floating end a water drag, which would hold the balloon in check until favouring gales returned. Funds, apparently, were not forthcoming to allow of Mr. Green's putting his bold method to the test; but we find him still adhering with so much zeal to his project that, five years later, he made, though again unsuccessfully, a second proposal to cross the Atlantic by balloon. He still continued to make many and most enterprising ascents, and one of a specially sensational nature must be briefly mentioned before we pass on to regard the exploits of other aeronauts. It was in 1841 on the occasion of a fete at Cremorne House, when Mr. Green, using his famous Nassau balloon, ascended with a Mr. Macdonnell. The wind was blowing with such extreme violence that Rainham, in Essex, about twenty miles distant, was reached in little more than a quarter of an hour, and here, on nearing the earth, the grapnel, finding good hold, gave a wrench to the balloon that broke the ring and jerked the car completely upside down, the aeronauts only escaping precipitation by holding hard to the ropes. A terrific steeplechase ensued, in which the travellers were dragged through stout fencing and other obstacles till the balloon, fairly emptied of gas, finally came to rest, but not until some severe injuries had been received. CHAPTER VIII. JOHN WISE--THE AMERICAN AERONAUT. By this period the domination of the air was being pursued in a fresh part of the world. England and her Continental neighbours had vied with each in adding to the roll of conquests, and it could hardly other be supposed that America would stand by without taking part in the campaign which was now being revived with so much fresh energy in the skies. The American champion who stepped forward was Mr. John Wise, of Lancaster, Pa., whose career, commencing in the year 1835, we must now for a while follow. Few attempts at ballooning of any kind had up to that time been made in all America. There is a record that in December, 1783, Messrs. Rittenhouse and Hopkins, Members of the Philosophical Academy of Philadelphia, instituted experiments with an aerial machine consisting of a cage to which forty-seven small balloons were harnessed. In this strange craft a carpenter, by name Wilcox, was induced to ascend, which, it is said, he did successfully, remaining in the air for ten minutes, when, finding himself near a river, he sought to come to earth again by opening several of his balloons. This brought about an awkward descent, attended, however, by no more serious accident than a dislocated wrist. Mr. Wise, on the other hand, states that Blanchard had won the distinction of making the first ascent in the New World in 1793 in Philadelphia on which occasion Washington was a spectator; and a few years afterwards other Frenchmen gave exhibitions, which, however, led to no real development of the new art on this, the further side of the Atlantic. Thus the endeavours we are about to describe were those of an independent and, at the same time, highly, practical experimentalist, and on this account have a special value of their own. The records that Wise has left of his investigations begin at the earliest stage, and possess the charm of an obvious and somewhat quaint reality. They commence with certain crude calculations which would seem to place no limit to the capabilities of a balloon. Thus, he points out that one of "the very moderate size of 400 feet diameter" would convey 13,000 men. "No wonder, then," he continues, "the citizens of London became alarmed during the French War, when they mistook the appearance of a vast flock of birds coming towards the Metropolis for Napoleon's army apparently coming down upon them with this new contrivance." Proceeding to practical measures, Wise's first care was to procure some proper material of which to build an experimental balloon of sufficient size to lift and convey himself alone. For this he chose ordinary long-cloth, rendered gas-tight by coats of suitable varnish, the preparation of which became with him, as, indeed, it remains to this day, a problem of chief importance and difficulty. Perhaps it hardly needs pointing out that the varnish of a balloon must not only be sufficiently elastic not to crack or scale off with folding or unavoidable rough usage, but it must also be of a nature to resist the common tendency of such substances to become adherent or "tacky." Wise determined on bird lime thinned with linseed oil and ordinary driers. With this preparation he coated his material several times both before and after the making up, and having procured a net, of which he speaks with pride, and a primitive sort of car, of which he bitterly complains, he thought himself sufficiently equipped to embark on an actual ascent, which he found a task of much greater practical difficulty than the mere manufacture of his air ship. For the inflation by hydrogen of so small a balloon as his was he made more than ample provision in procuring no less than fifteen casks of 130 gallons capacity each. He also duly secured a suitable filling ground at the corner of Ninth and Green Streets, Philadelphia, but he made a miscalculation as to the time the inflation would demand, and this led to unforeseen complications, for as yet he knew not the way of a crowd which comes to witness a balloon ascent. Having all things in readiness, and prudently waiting for fair weather, he embarked on his grand experiment on the 2nd of May, 1835, announcing 4 p.m. as the hour of departure. But by that time the inflation, having only proceeded for three hours, the balloon was but half full, and then the populace began to behave as in such circumstances they always will. They were incredulous, and presently grew troublesome. In vain the harnessing of the car was proceeded with as though all were well. For all was not well, and when the aeronaut stepped into his car with only fifteen pounds of sand and a few instruments he must have done so with much misgiving. Still, he had friends around who might have been useful had they been less eager to help. But these simply crowded round him, giving him no elbow room, nor opportunity for trying the "lift" of his all-too-empty globe. Moreover, some would endeavour to throw the machine upward, while others as strenuously strove to keep it down, and at last the former party prevailed, and the balloon, being fairly cast into the air, grazed a neighbouring chimney and then plunged into an adjacent plot, not, however, before the distracted traveller had flung away all his little stock of sand. There now was brief opportunity for free action, and to the first bystander who came running up Wise gave the task of holding the car in check. To the next he handed out his instruments, his coat, and also his boots, hoping thus to get away; but his chance had not yet come, for once again the crowd swarmed round him, keeping him prisoner with good-natured but mistaken interference, and drowning his voice with excited shouting. Somehow, by word and gesture, he gave his persecutors to understand that he wished to speak, and then he begged them only to give him a chance, whereupon the crowd fell back, forming a ring, and leaving only one man holding the car. It was a moment of suspense, for Wise calculated that he had only parted with some eighteen pounds since his first ineffectual start from the filling ground; but it was enough, and in another moment he was sailing up clear above the crowd. So great, as has been already shewn, is often the effect of parting with the last few pounds of dead weight in a well-balanced balloon. Such was the first "send off" of the future great balloonist, destined to become the pioneer in aeronautics on the far side of the Atlantic. The balloon ascended to upwards of a mile, floating gradually away, but at its highest point it reached a conflict of currents, causing eddies from which Wise escaped by a slight decrease of weight, effected by merely cutting away the wreaths of flowers that were tied about his car. A further small substitute for ballast he extemporised in the metal tube inserted in the neck of his fabric, and this he cast out when over the breadth of the Delaware, and he describes it as falling with a rustling sound, and striking the water with a splash plainly heard at more than a mile in the sky. After an hour and a quarter the balloon spontaneously and steadily settled to earth. An ascent carried out later in the same summer led to a mishap, which taught the young aeronaut an all-important lesson. Using the same balloon and the same mode of inflation, he got safely and satisfactorily away from his station in the town of Lebanon, Pa., and soon found himself over a toll gate in the open country, where the gate keeper in banter called up to him for his due. To this summons Wise, with heedless alacrity, responded in a manner which might well have cost him dear. He threw out a bag of sand to represent his toll, and, though he estimated this at only six pounds, it so greatly accelerated his ascent that he shortly found himself at a greater altitude than he ever after attained. He passed through mist into upper sunshine, where he experienced extreme cold and ear-ache, at which time, seeking the natural escape from such trouble, he found to his dismay that the valve rope was out of reach. Thus he was compelled to allow the balloon to ascend yet higher, at its own will; and then a terrible event happened. By mischance the neck of his balloon, which should have been open, was out of reach and folded inwards in such a way as to prevent the free escape of the gas, which, at this great altitude, struggled for egress with a loud humming noise, giving him apprehensions of an accident which very shortly occurred, namely, the bursting of the lower part of his balloon with a loud report. It happened, however, that no extreme loss of gas ensued, and he commenced descending with a speed which, though considerable, was not very excessive. Still, he was eager to alight in safety, until a chance occurrence made him a second time that afternoon guilty of an act of boyish impetuosity. A party of volunteers firing a salute in his honour as he neared the ground, he instantly flung out papers, ballast, anything he could lay his hands on, and once again soared to a great height with his damaged balloon. He could then do no more, and presently subsiding to earth again, he acquired the welcome knowledge that even in such precarious circumstances a balloon may make a long fall with safety to its freight. Mr. Wise's zeal and indomitable spirit of enterprise led to speedy developments of the art which he had espoused; the road to success being frequently pointed out by failure or mishap. He quickly discarded the linen balloon for one of silk on which he tried a new varnish composed of linseed oil and india-rubber, and, dressing several gores with this, he rolled them up and left them through a night in a drying loft, with the result that the next day they were disintegrated and on the point of bursting into flame by spontaneous combustion. Fresh silk and other varnish were then tried, but with indifferent success. Next he endeavoured to dispense with sewing, and united the gores of yet another balloon by the mere adhesiveness of the varnish and application of a hot iron. This led to a gaping seam developing at the moment of an ascent, and then there followed a hasty and hazardous descent on a house-top and an exciting rescue by a gentleman who appeared opportunely at a third storey window. Further, another balloon had been destroyed, and Wise badly burned, at a descent, owing to a naked light having been brought near the escaping gas. It is then without wonder that we find him after this temporarily bankrupt, and resorting to his skill in instrument-making to recover his fortunes. Only, however, for a few months, after which he is before the public once more as a professional aeronaut. He now adopts coal gas for inflation, and incidents of an impressive nature crowd into his career, forcing important facts upon him. The special characteristics of his own country present peculiar difficulties; broad rivers and vast forests become serious obstacles. He is caught in the embrace of a whirlwind; he narrowly escapes falling into a forest fire; he is precipitated, but harmlessly, into a pine wood. Among other experiments, he makes a small copy of Mr. Cocking's parachute, and drops it to earth with a cat as passenger, proving thereby that that unfortunate gentleman's principle was really less in fault than the actual slenderness of the material used in his machine. We now approach one of Wise's boldest, and at the same time most valuable, experiments. It was the summer of 1839, and once again the old trouble of spontaneous combustion had destroyed a silk balloon which was to have ascended at Easton, Pa. Undeterred, however, Wise resolutely advertised a fresh attempt, and, with only a clear month before the engagement, determined on hastily rigging up a cambric muslin balloon, soaking it in linseed oil and essaying the best exhibition that this improvised experiment could afford. It was intended to become a memorable one, inasmuch as, should he meet with no hindrance, his determination was nothing less than that of bursting this balloon at a great height, having firmly convinced himself that the machine in these circumstances would form itself into a natural parachute, and bring him to earth with every chance in favour of safety. In his own words, "Scientific calculations were on his side with a certainty as great and principles as comprehensive as that a pocket-handkerchief will not fall as rapidly to the ground when thrown out of a third storey window as will a brick." His balloon was specially contrived for the experiment in hand, having cords sewn to the upper parts of its seams, and then led down through the neck, where they were secured within reach, their office being that of rending the whole head of the balloon should this be desired. On this occasion a cat and a dog were taken up, one of these being let fall from a height of 2,000 feet in a Cocking's parachute, and landing in safety, the other being similarly dismissed at an altitude of 4,000 feet in an oiled silk balloon made in the form of a collapsed balloon, which, after falling a little distance, expanded sufficiently to allow of its descending with a safe though somewhat vibratory motion. Its behaviour, at any rate, fully determined Wise on carrying out his own experiment. Being constructed entirely for the main object in view, the balloon had no true opening in the neck beyond an orifice of about an inch, and by the time a height of 13,000 feet had been reached the gas was streaming violently through this small hole, the entire globe being expanded nearly to bursting point, and the cords designed for rending the balloon very tense. At this critical period Wise owns to having experienced considerable nervous excitement, and observing far down a thunderstorm in progress he began to waver in his mind, and inclined towards relieving the balloon of its strain, and so abandoning his experiment, at least for the present. He remembers pulling out his watch to make a note of the hour, and, while thus occupied, the straining cords, growing tenser every moment, suddenly took charge of the experiment and burst the balloon of their own accord. The gas now rushed from the huge rent above tumultuously and in some ten seconds had entirely escaped, causing the balloon to descend rapidly, until the lower part of the muslin, doubling in upwards, formed a species of parachute after the manner intended. The balloon now came down with zig-zag descent, and finally the car, striking the earth obliquely, tossed its occupant out into a field unharmed. Shortly after this Wise experimented with further success with an exploded balloon. It is not a little remarkable that this pioneer of aeronautics in American--a contemporary of Charles Green in England, but working and investigating single-handed on perfectly independent lines--should have arrived at the same conclusions as did Green himself as to the possibility, which, in his opinion, amounted to a certainty, of being able to cross the Atlantic by balloon if only adequate funds were forth-coming. So intent was he on his bold scheme that, in the summer of 1843, he handed to the Lancaster Intelligencer a proclamation, which he desired might be conveyed to all publishers of newspapers on the globe. It contained, among other clauses, the following:-- "Having from a long experience in aeronautics been convinced that a constant and regular current of air is blowing at all times from west to east, with a velocity of from twenty to forty and even sixty miles per hour, according to its height from the earth, and having discovered a composition which renders silk or muslin impervious to hydrogen gas, so that a balloon may be kept afloat for many weeks, I feel confident with these advantages that a trip across the Atlantic will not be attended with as much real danger as by the common mode of transition. The balloon is to be 100 feet in diameter, giving it a net ascending power of 25,000 lbs." It was further stated that the crew would consist of three persons, including a sea navigator, and a scientific landsman. The specifications for the transatlantic vessel were also to include a seaworthy boat in place of the ordinary car. The sum requisite for this enterprise was, at the time, not realised; but it should be mentioned that several years later a sufficient sum of money was actually subscribed. In the summer of 1873 the proprietors of the New York Daily Graphic provided for the construction of a balloon of no less than 400,000 cubic feet capacity, and calculated to lift 14,000 lbs. It was, however, made of bad material; and, becoming torn in inflation, Wise condemned and declined to use it. A few months later, when it had been repaired, one Donaldson and two other adventurers, attempting a voyage with this ill-formed monster, ascended from New York, and were fortunate in coming down safely, though not without peril, somewhere in Connecticut. Failing in his grand endeavour, Wise continued to follow the career of a professional aeronaut for some years longer, of which he has left a full record, terminating with the spring of 1848. His ascents were always marked by carefulness of detail, and a coolness and courage in trying circumstances that secured him uniform success and universal regard. He was, moreover, always a close and intelligent observer, and many of his memoranda are of scientific value. His description of an encounter with a storm-cloud in the June of 1843 has an interest of its own, and may not be considered overdrawn. It was an ascent from Carlisle, Pa., to celebrate the anniversary of Bunker's Hill, and Wise was anxious to gratify the large concourse of people assembled, and thus was tempted, soon after leaving the ground, to dive up into a huge black cloud of peculiarly forbidding aspect. This cloud appeared to remain stationary while he swept beneath it, and, having reached its central position, he observed that its under surface was concave towards the earth, and at that moment he became swept upwards in a vortex that set his balloon spinning and swinging violently, while he himself was afflicted with violent nausea and a feeling of suffocation. The cold experienced now became intense, and the cordage became glazed with ice, yet this had no effect in checking the upward whirling of the balloon. Sunshine was beyond the upper limits of the cloud; but this was no sooner reached than the balloon, escaping from the uprush, plunged down several hundred feet, only to be whirled up again, and this reciprocal motion was repeated eight or ten times during an interval of twenty minutes, in all of which time no expenditure of gas or discharge of ballast enabled the aeronaut to regain any control over his vessel. Statements concerning a thunderstorm witnessed at short range by Wise will compare with other accounts. The thunder "rattled" without any reverberations, and when the storm was passing, and some dense clouds moving in the upper currents, the "surface of the lower stratum swelled up suddenly like a boiling cauldron, which was immediately followed by the most brilliant ebullition of sparkling coruscations." Green, in his stormy ascent from Newbury, England, witnessed a thunderstorm below him, as will be remembered, while an upper cloud stratum lay at his own level. It was then that Green observed that "at every discharge of thunder all the detached pillars of clouds within the distance of a mile around became attracted." The author will have occasion, in due place, to give personal experiences of an encounter with a thunderstorm which will compare with the foregoing description. CHAPTER IX. EARLY METHODS AND IDEAS. Before proceeding to introduce the chief actors and their achievements in the period next before us, it will be instructive to glance at some of the principal ideas and methods in favour with aeronauts up to the date now reached. It will be seen that Wise in America, contrary to the practice of Green in our own country, had a strong attachment to the antique mode of inflation with hydrogen prepared by the vitriolic process; and his balloons were specially made and varnished for the use of this gas. The advantage which he thus bought at the expense of much trouble and the providing of cumbersome equipment was obvious enough, and may be well expressed by a formula which holds good to-day, namely, that whereas 1,000 cubic feet of hydrogen is capable of lifting 7 lbs., the same quantity of coal gas of ordinary quality will raise but 35 lbs. The lighter gas came into all Wise's calculations for bolder schemes. Thus, when he discusses the possibility of using a metal balloon, his figures work out as follows: If a balloon of 200 feet diameter were constructed out of copper, weighing one pound to the square foot; if, moreover, some six tons were allowed for the weight of car and fastenings, an available lifting power would remain capable of raising 45 tons to an altitude of two miles. This calculation may appear somewhat startling, yet it is not only substantially correct, but Wise entertained no doubt as to the practicability of such a machine. For its inflation he suggests inserting a muslin balloon filled with air within the copper globe, and then passing hydrogen gas between the muslin and copper surfaces, which would exclude the inner balloon as the copper one filled up. His method of preparing hydrogen was practically that still adopted in the field, and seems in his hands to have been seldom attended with difficulty. With eight common 130-gallon rum puncheons he could reckon on evolving 5,000 cubic feet of gas in an hour, using his elements in the following proportions: water, 560 lbs.; sulphuric acid (sp. g. 1.85), 144 lbs.; iron turnings, 125 lbs. The gas, as given off, was cooled and purified by being passed through a head of water kept cool and containing lime in solution. Contrasted with this, we find it estimated, according to the practice of this time, that a ton of good bituminous coal should yield 10,000 cubic feet of carburetted hydrogen fit for lighting purposes, and a further quantity which, though useless as an illuminant, is still of excellent quality for the aeronaut. It would even seem from a statement of Mr. Monck Mason that the value of coke in his day largely compensated for the cost of producing coal gas, so that in a large number of Green's ascents no charge whatever was made for gas by the companies that supplied him. Some, at least, of the methods formerly recommended for the management of free balloons must in these days be modified. Green, as we have seen, was in favour of a trail rope of inordinate length, which he recommended both as an aid to steering and for a saving of ballast. In special circumstances, and more particularly over the sea, this may be reckoned a serviceable adjunct, but over land its use, in this country at least, would be open to serious objection. The writer has seen the consternation, not to say havoc, that a trail rope may occasion when crossing a town, or even private grounds, and the actual damage done to a garden of hops, or to telegraph or telephone wires, may be very serious indeed. Moreover, the statement made by some early practitioners that a trail rope will not catch so as to hold fast in a wood or the like, is not to be relied on, for an instance could be mentioned coming under the writer's knowledge where such a rope was the source of so much trouble in a high wind that it had to be cut away. The trouble arose in this way. The rope dragged harmlessly enough along the open ground. It would, likewise, negotiate exceedingly well a single tree or a whole plantation, catching and releasing itself with only such moderate tugs at the car as were not disturbing; but, presently, its end, which had been caught and again released by one tree, swung free in air through a considerable gap to another tree, where, striking a horizontal bough, it coiled itself several times around, and thus held the balloon fast, which now, with the strength of the wind, was borne to the earth again and again, rebounding high in air after each impact, until freedom was gained only by the sacrifice of a portion of the rope. Wise recommends a pendant line of 600 or 800 feet, capable of bearing a strain of 100 lbs., and with characteristic ingenuity suggests a special use which can be made of it, namely, that of having light ribbons tied on at every hundred feet, by means of which the drifts of lower currents may be detected. In this suggestion there is, indeed, a great deal of sound sense; for there is, as will be shown hereafter, very much value to be attached to a knowledge of those air rivers that are flowing, often wholly unsuspected, at various heights. Small parachutes, crumpled paper, and other such-like bodies as are commonly thrown out and relied on to declare the lower drifts, are not wholly trustworthy, for this reason--that air-streams are often very slender, mere filaments, as they are sometimes called, and these, though setting in some definite direction, and capable of entrapping and wafting away some small body which may come within their influence, may not affect the travel of so big an object as a balloon, which can only partake of some more general air movement. Wise, by his expedient of tying ribbons at different points to his trail rope, would obtain much more correct and constant information respecting those general streams through which the pendant rope was moving. A similar expedient adopted by the same ingenious aeronaut is worthy of imitation, namely, that of tying ribbons on to a rod projecting laterally from the car. These form a handy and constant telltale as to the flight of the balloon, for should they be fluttering upwards the sky sailor at once knows that his craft is descending, and that he must act accordingly. The material, pure silk, which was universally adopted up to and after the period we are now regarding, is not on every account to be reckoned the most desirable. In the first place, its cost alone is prohibitive, and next, although lighter than any kind of linen, strength for strength, it requires a greater weight of varnish, which, moreover, it does not take so kindly as does fabric made of vegetable tissue. Further, paradoxical as it may appear, its great strength is not entirely an advantage. There are occasions which must come into the experience of every zealous aeronaut when his balloon has descended in a rough wind, and in awkward country. This may, indeed, happen even when the ascent has been made in calm. Squalls of wind may spring up at short notice, or after traversing only two or three counties a strong gale may be found on the earth, though such was absent in the starting ground. This is more particularly the case when the landing chances to be on high ground in the neighbourhood of the sea. In these circumstances, the careful balloonist, who will generally be forewarned by the ruffle on any water he may pass, or by the drift of smoke, the tossing of trees, or by their very rustling or "singing" wafted upwards to him, will, if possible, seek for his landing place the lee of a wood or some other sheltered spot. But, even with all his care, he will sometimes find himself, on reaching earth, being dragged violently across country on a mad course which the anchor cannot check. Now, the country through which he is making an unwilling steeplechase may be difficult, or even dangerous. Rivers, railway cuttings, or other undesirable obstacles may lie ahead, or, worse yet, such a death trap as in such circumstances almost any part of Derbyshire affords, with its stone walls, its precipitous cliffs, and deep rocky dells. To be dragged at the speed of an express train through territory of this description will presently mean damage to something, perhaps to telegraph poles, to roofs, or crops, and if not, then to the balloon itself. Something appertaining to it must be victimised, and it is in all ways best that this should be the fabric of the balloon itself. If made of some form, or at least some proportion of linen, this will probably rend ere long, and, allowing the gas to escape, will soon bring itself to rest. On the other hand, if the balloon proper is a silk one, with sound net and in good condition, it is probable that something else will give way first, and that something may prove to be the hapless passenger or passengers. And here be it laid down as one first and all-important principle, that in any such awkward predicament as that just described, if there be more than one passenger aboard, let none attempt to get out. In the first place, he may very probably break a limb in so doing, inasmuch as the tangle of the ropes will not allow of his getting cut readily; or, when actually on the ground, he may be caught and impaled by the anchor charging and leaping behind. But, worse than all, he may, in any case, jeopardise the lives of his companions, who stand in need of all the available weight and help that the car contains up to the moment Of coming to final rest. We have already touched on the early notions as to the means of steering a balloon. Oars had been tested without satisfactory result, and the conception of a rotary screw found favour among theorists at this time, the principle being actually tried with success in working models, which, by mechanical means, could be made to flit about in the still air of the lecture room; but the only feasible method advocated was that already alluded to, which depended on the undesirable action of a trail rope dragging over the ground or through water. The idea was, of course, perfectly practical, and was simply analogous to the method adopted by sailors, who, when floating with the stream but without wind, are desirous of gaining "steerage way." While simply drifting with the flood, they are unable to guide their vessel in any way, and this, in practice, is commonly effected by simply propelling the vessel faster than the stream, in which case the rudder at once becomes available. But the same result is equally well obtained by slowing the vessel, and this is easily accomplished by a cable, with a small anchor or other weight attached, dragging below the vessel. This cable is essentially the same as the guide-rope of the older aeronauts. It is when we come to consider the impressions and sensations described by sky voyagers of bygone times that we find them curiously at variance with our own. As an instance, we may state that the earth, as seen from a highflying balloon, used to be almost always described as appearing concave, or like a huge basin, and ingenious attempts were made to prove mathematically that this must be so. The laws of refraction are brought in to prove the fact; or, again, the case is stated thus: Supposing the extreme horizon to be seen when the balloon is little more than a mile high, the range of view on all sides will then be, roughly, some eighty miles. If, then, a line were drawn from the aerial observer to this remote distance, that line would be almost horizontal; so nearly so that he cannot persuade himself that his horizon is otherwise than still on a level with his eye; yet the earth below him lies, as it seems, at the bottom of a huge gulf. Thus the whole visible earth appears as a vast bowl or basin. This is extremely ingenious reasoning, and not to be disregarded; but the fact remains that in the experience of the writer and of many others whom he has consulted, there is no such optical illusion as I have just discussed, and to their vision it is impossible to regard the earth as anything but uniformly flat. Another impression invariably insisted on by early balloonists is that the earth, on quitting it, appears to drop away into an abyss, leaving the voyagers motionless, and this illusion must, indeed, be probably universal. It is the same illusion as the apparent gliding backwards of objects to a traveller in a railway carriage; only in this latter case the rattling and shaking of the carriage helps the mind to grasp the real fact that the motion belongs to the train itself; whereas it is otherwise with a balloon, whose motion is so perfectly smooth as to be quite imperceptible. Old ideas, formed upon insufficient observations, even if erroneous, were slow to die. Thus it used to be stated that an upper cloud floor adapted itself to the contour of the land over which it rested, giving what Mr. Monck Mason has called a "phrenological estimate" of the character of the earth below; the clouds, "even when under the influence of rapid motion, seeming to accommodate themselves to all variations of form in the surface of the subjacent soil, rising with its prominences and sinking with its depressions." Probably few aeronauts of the present time will accept the statement. It used commonly to be asserted, and is so often to this day, that a feeling as of sea-sickness is experienced in balloon travel, and the notion has undoubtedly arisen from the circumstances attending an ascent in a captive balloon. It were well, now that ballooning bids fair to become popular, to disabuse the public mind of such a wholly false idea. The truth is that a balloon let up with a lengthy rope and held captive will, with a fitful breeze, pitch and sway in a manner which may induce all the unpleasant feelings attending a rough passage at sea. It may do worse, and even be borne to earth with a puff of wind which may come unexpectedly, and considerably unsettle the nerves of any holiday passenger. I could tell of a "captive" that had been behaving itself creditably on a not very settled day suddenly swooping over a roadway and down into public gardens, where it lay incontinently along the ground, and then, before the astonished passengers could attempt to alight, it was seized with another mood, and, mounting once again majestically skyward, submitted to be hauled down with all becoming grace and ease. It is owing to their vagaries and want of manageability that, as will be shown, "captives" are of uncertain use in war. On the other hand, a free balloon is exempt from such disadvantages, and at moderate heights not the smallest feeling of nausea is ever experienced. The only unpleasant sensation, and that not of any gravity, ever complained of, is a peculiar tension in the ears experienced in a rapid ascent, or more often, perhaps, in a descent. The cause, which is trivial and easily removed, should be properly understood, and cannot be given in clearer language than that used by Professor Tyndall:--"Behind the tympanic membrane exists a cavity--the drum of the ear--in part crossed by a series of bones, and in part occupied by air. This cavity communicates with the mouth by means of a duct called the Eustachian tube. This tube is generally closed, the air space behind the tympanic membrane being thus cut off from the external air. If, under these circumstances, the external air becomes denser, it will press the tympanic membrane inwards; if, on the other hand, the air on the other side becomes rarer, while the Eustachian tube becomes closed, the membrane will be pressed outwards. Pain is felt in both cases, and partial deafness is experienced.... By the act of swallowing the Eustachian tube is opened, and thus equilibrium is established between the external and internal pressure." Founded on physical facts more or less correct in themselves, come a number of tales of olden days, which are at least more marvellous than credible, the following serving as an example. The scientific truth underlying the story is the well-known expedient of placing a shrivelled apple under the receiver of an air pump. As the air becomes rarefied the apple swells, smooths itself out, and presently becomes round and rosy as it was in the summer time. It is recorded that on one occasion a man of mature years made an ascent, accompanied by his son, and, after reaching some height, the youth remarked on how young his father was looking. They still continued to ascend, and the same remark was repeated more than once. And at last, having now reached attenuated regions, the son cried in astonishment, "Why, dad, you ought to be at school!" The cause of this remark was that in the rarefied air all the wrinkles had come out of the old man's face, and his cheeks were as chubby as his son's. This discussion of old ideas should not be closed without mention of a plausible plea for the balloon made by Wise and others on the score of its value to health. Lofty ascents have proved a strain on even robust constitutions--the heart may begin to suffer, or ills akin to mountain sickness may intervene before a height equal to that of our loftiest mountain is reached. But many have spoken of an exhilaration of spirits not inferior to that of the mountaineer, which is experienced, and without fatigue, in sky voyages reasonably indulged in--of a light-heartedness, a glow of health, a sharpened appetite, and the keen enjoyment of mere existence. Nay, it has been seriously affirmed that "more good may be got by the invalid in an hour or two while two miles up on a fine summer's day than is to be gained in an entire voyage from New York to Madeira by sea." CHAPTER X. THE COMMENCEMENT OF A NEW ERA. Resuming the roll of progressive aeronauts in England whose labours were devoted to the practical conquest of the air, and whose methods and mechanical achievements mark the road of advance by which the successes of to-day have been obtained, there stand out prominently two individuals, of whom one has already received mention in these pages. The period of a single life is seldom sufficient to allow within its span the full development of any new departure in art or science, and it cannot, therefore, be wondered at if Charles Green, though reviving and re-modelling the art of ballooning in our own country, even after an exceptionally long and successful career, left that pursuit to which he had given new birth virtually still in its infancy. The year following that in which Green conducted the famous Nassau voyage we find him experimenting in the same balloon with his chosen friend and colleague, Edward Spencer, solicitor, of Barnsbury, who, only nine years later, compiles memoranda of thirty-four ascents, made under every variety of circumstance, many being of a highly enterprising nature. We find him writing enthusiastically of the raptures he experienced when sailing over London in night hours, of lofty ascents and extremely low temperatures, of speeding twenty-eight miles in twenty minutes, of grapnel ropes breaking, and of a cross-country race of four miles through woods and hedges. Such was Mr. Spencer the elder, and if further evidence were needed of his practical acquaintance with, as well as personal devotion to, his adopted profession of aeronautics, we have it in the store of working calculations and other minutiae of the craft, most carefully compiled in manuscript by his own hand; these memoranda being to this day constantly consulted by his grandsons, the present eminent aeronauts, Messrs. Spencer Brothers, as supplying a manual of reliable data for the execution of much of the most important parts of their work. In the terrific ordeal and risk entailed by the daring and fatal parachute descent of Cocking, Green required an assistant of exceptional nerve and reliability, and, as has been recorded, his choice at once fell on Edward Spencer. In this choice it has already been shown that he was well justified, and in the trying circumstances that ensued Green frankly owns that it was his competent companion who was the first to recover himself. A few years later, when a distinguished company, among whom were Albert Smith and Shirley Brooks, made a memorable ascent from Cremorne, Edward Spencer is one of the select party. Some account of this voyage should be given, and it need not be said that no more graphic account is to be found than that given by the facile pen of Albert Smith himself. His personal narrative also forms an instructive contrast to another which he had occasion to give to the world shortly afterwards, and which shall be duly noticed. The enthusiastic writer first describes, with apparent pride, the company that ascended with him. Besides Mr. Shirley Brooks, there were Messrs. Davidson, of the Garrick Club; Mr. John Lee, well known in theatrical circles; Mr. P. Thompson, of Guy's Hospital, and others--ten in all, including Charles Green as skipper, and Edward Spencer, who, sitting in the rigging, was entrusted with the all-important management of the valve rope. "The first sensation experienced," Albert Smith continues, "was not that we were rising, but that the balloon remained fixed, whilst all the world below was rapidly falling away; while the cheers with which they greeted our departure grew fainter, and the cheerers themselves began to look like the inmates of many sixpenny Noah's Arks grouped upon a billiard table.... Our hats would have held millions.... And most strange is the roar of the city as it comes surging into the welkin as though the whole metropolis cheered you with one voice.... Yet none beyond the ordinary passengers are to be seen. The noise is as inexplicable as the murmur in the air at hot summer noontide." The significance of this last remark will be insisted on when the writer has to tell his own experiences aloft over London, as also a note to the effect that there were seen "large enclosed fields and gardens and pleasure grounds where none were supposed to exist by ordinary passengers." Another interesting note, having reference to a once familiar feature on the river, now disappearing, related to the paddle boats of those days, the steamers making a very beautiful effect, "leaving two long wings of foam behind them similar to the train of a table rocket." Highly suggestive, too, of the experiences of railway travellers in the year 1847 is the account of the alighting, which, by the way, was obviously of no very rude nature. "Every time," says the writer, "the grapnel catches in the ground the balloon is pulled up suddenly with a shock that would soon send anybody from his seat, a jerk like that which occurs when fresh carriages are brought up to a railway train." But the concluding paragraph in this rosy narrative affords another and a very notable contrast to the story which that same writer had occasion to put on record before that same year had passed. "We counsel everybody to go up in a balloon... In spite of the apparent frightful fragility of cane and network nothing can in reality be more secure... The stories of pressure on the ears, intense cold, and the danger of coming down are all fictions.... Indeed, we almost wanted a few perils to give a little excitement to the trip, and have some notion, if possible, of going up the next time at midnight with fireworks in a thunderstorm, throwing away all the ballast, fastening down the valve, and seeing where the wind will send us." The fireworks, the thunderstorm, and the throwing away of ballast, all came off on the 15th of the following October, when Albert Smith made his second ascent, this time from Vauxhall Gardens, under the guidance of Mr. Gypson, and accompanied by two fellow-passengers. Fireworks, which were to be displayed when aloft, were suspended on a framework forty feet below the car. Lightning was also playing around as they cast off. The description which Albert Smith gives of London by night as seen from an estimated elevation of 4,000 feet, should be compared with other descriptions that will be given in these pages:-- "In the obscurity all traces of houses and enclosures are lost sight of. I can compare it to nothing else than floating over dark blue and boundless sea spangled with hundreds of thousands of stars. These stars were the lamps. We could see them stretching over the river at the bridges, edging its banks, forming squares and long parallel lines of light in the streets and solitary parks. Further and further apart until they were altogether lost in the suburbs. The effect was bewildering." At 7,000 feet, one of the passengers, sitting in the ring, remarked that the balloon was getting very tense, and the order was given to "ease her" by opening the top valve. The valve line was accordingly pulled, "and immediately afterwards we heard a noise similar to the escape of steam in a locomotive, and the lower part of the balloon collapsed rapidly, and appeared to fly up into the upper portion. At the same instant the balloon began to fall with appalling velocity, the immense mass of loose silk surging and rustling frightfully over our heads.... retreating up away from us more and more into the head of the balloon. The suggestion was made to throw everything over that might lighten the balloon. I had two sandbags in my lap, which were cast away directly.... There were several large bags of ballast, and some bottles of wine, and these were instantly thrown away, but no effect was perceptible. The wind still appeared to be rushing up past us at a fearful rate, and, to add to the horror, we came among the still expiring discharge of the fireworks which floated in the air, so that little bits of exploded cases and touch-paper, still incandescent, attached themselves to the cordage of the balloon and were blown into sparks.... I presume we must have been upwards of a mile from the earth.... How long we were descending I have not the slightest idea, but two minutes must have been the outside.... We now saw the houses, the roofs of which appeared advancing to meet us, and the next instant, as we dashed by their summits, the words, 'Hold hard!' burst simultaneously from all the party.... We were all directly thrown out of the car along the ground, and, incomprehensible as it now appears to me, nobody was seriously hurt." But "not so incomprehensible, after all," will be the verdict of all who compare the above narrative with the ascents given in a foregoing account of how Wise had fared more than once when his balloon had burst. For, as will be readily guessed, the balloon had in this case also burst, owing to the release of the upper valve being delayed too long, and the balloon had in the natural way transformed itself into a true parachute. Moreover, the fall, which, by Albert Smith's own showing, was that of about a mile in two minutes, was not more excessive than one which will presently be recorded of Mr. Glaisher, who escaped with no material injury beyond a few bruises. One fact has till now been omitted with regard to the above sensational voyage, namely, the name of the passenger who, sitting in the ring, was the first to point out the imminent danger of the balloon. This individual was none other than Mr. Henry Coxwell, the second, indeed, of the two who were mentioned in the opening paragraph of this chapter as marking the road of progress which it is the scope of these pages to trace, and to whom we must now formally introduce our readers. This justly famous sky pilot, whose practical acquaintance with ballooning extends over more than forty years, was the son of a naval officer residing near Chatham, and in his autobiography he describes enthusiastically how, a lad of nine years old, he watched through a sea telescope a balloon, piloted by Charles Green, ascend from Rochester and, crossing the Thames, disappear in distance over the Essex flats. He goes on to describe how the incident started him in those early days on boyish endeavours to construct fire balloons and paper parachutes. Some years later his home, on the death of his father, being transferred to Eltham, he came within frequent view of such balloons as, starting from the neighbourhood of London, will through the summer drift with the prevailing winds over that part of Kent. And it was here that, ere long, he came in at the death of another balloon of which Green was in charge. And from this time onwards the schoolboy with the strange hobby was constantly able to witness the flights and even the inflations of those ships of the air, which, his family associations notwithstanding took precedence of all boyish diversions. His elder brother, now a naval officer, entirely failed to divert his aspirations into other channels, and it was when the boy had completed sixteen summers that an aeronautic enterprise attracted not only his own, but public attention also. It was the building of a mammoth balloon at Vauxhall under the superintendence of Mr. Green. The launching of this huge craft when completed was regarded as so great an occasion that the young Coxwell, who had by this time obtained a commercial opening abroad, was allowed, at his earnest entreaty, to stay till the event had come off, and fifty years after the hardened sky sailor is found describing with a boyish enthusiasm how thirty-six policemen were needed round that balloon; how enormous weights were attached to the cordage, only to be lifted feet above the ground; while the police were compelled to pass their staves through the meshes to prevent the cords cutting their hands. At this ascent Mr. Hollond was a passenger, and by the middle of the following November all Europe was ringing with the great Nassau venture. Commercial business did not suit the young Coxwell, and at the age of one-and-twenty we find him trying his hand at the profession of surgeon-dentist, not, however, with any prospect of its keeping him from the longing of his soul, which grew stronger and stronger upon him. It was not till the summer of 1844 that Mr. Hampton, giving an exhibition from the White Conduit Gardens, Pentonville, offered the young man, then twenty-five years old, his first ascent. In after years Coxwell referred to his first sensations in characteristic language, contrasting them with the experiences of the mountaineer. "In Alpine travels," he says, "the process is so slow, and contact with the crust of the earth so palpable, that the traveller is gradually prepared for each successive phase of view as it presents itself. But in the balloon survey, cities, villages, and vast tracts for observation spring almost magically before the eye, and change in aspect and size so pleasingly that bewilderment first and then unbounded admiration is sure to follow." The ice was now fairly broken, and, not suffering professional duties to be any hindrance, Coxwell began to make a series of ascents under the leadership of two rival balloonists, Gale and Gypson. One voyage made with the latter he describes as leading to the most perilous descent in the annals of aerostation. This was the occasion, given above, on which Albert Smith was a passenger, and which that talented writer describes in his own fashion. He does not, however, add the fact, worthy of being chronicled, that exactly a week after the appalling adventure Gypson and Coxwell, accompanied by a Captain whose name does not transpire, and loaded with twice the previous weight of fireworks, made a perfectly successful night ascent and descent in the same balloon. It is very shortly after this that we find Coxwell seduced into undertaking for its owners the actual management of a balloon, the property of Gale, and now to be known as the "Sylph." With this craft he practically began his career as a professional balloonist, and after a few preliminary ascents made in England, was told off to carry on engagements in Belgium. A long series of ascents was now made on the Continent, and in the troubled state of affairs some stirring scenes were visited, not without some real adventure. One occasion attended with imminent risk occurred at Berlin in 1851. Coxwell relates that a Prussian labourer whom he had dismissed for bad conduct, and who almost too manifestly harboured revenge, nevertheless begged hard for a re-engagement, which, as the man was a handy fellow, Coxwell at length assented to. He took up three passengers beside himself, and at an elevation of some 3,000 feet found it necessary to open the valve, when, on pulling the cord, one of the top shutters broke and remained open, leaving a free aperture of 26 inches by 12 inches, and occasioning such a copious discharge of gas that nothing short of a providential landing could save disaster. But the providential landing came, the party falling into the embrace of a fruit tree in an orchard. It transpired afterwards that the labourer had been seen to tamper with the valve, the connecting lines of which he had partially severed. Returning to England in 1852 Coxwell, through the accidents inseparable from his profession, found himself virtually in possession of the field. Green, now advanced in years, was retiring from the public life in which he had won so much fame and honour. Gale was dead, killed in an ascent at Bordeaux. Only one aspirant contested the place of public aeronaut--one Goulston, who had been Gale's patron. Before many months, however, he too met with a balloonist's death, being dashed against some stone walls when ascending near Manchester. It will not be difficult to form an estimate of how entirely the popularity of the balloon was now reestablished in England, from the mere fact that before the expiration of the year Coxwell had been called upon to make thirty-six voyages. Some of these were from Glasgow, and here a certain coincidence took place which is too curious to be omitted. A descent effected near Milngavie took place in the same field in which Sadler, twenty-nine years before, had also descended, and the same man who caught the rope of Mr. Sadler's balloon performed the same service once again for a fresh visitor from the skies. The following autumn Coxwell, in fulfilling one out of many engagements, found himself in a dilemma which bore resemblance in a slight degree to a far more serious predicament in which the writer became involved, and which must be told in due place. The preparations for the ascent, which was from the Mile End Road, had been hurried, and after finally getting away at a late hour in the evening, it was found that the valve line had got caught in a fold of the silk, and could not be operated. In consequence, the balloon was, of necessity, left to take its own chance through the night, and, after rising to a considerable height, it slowly lost buoyancy during the chilly hours, and, gradually settling, came to earth near Basingstoke, where the voyager, failing to get help or shelter, made his bed within his own car, lying in an open field, as other aeronauts have had to do in like circumstances. Coxwell tells of a striking phenomenon seen during that voyage. "A splendid meteor was below the car, and apparently about 600 feet distant. It was blue and yellow, moving rapidly in a N.E. direction, and became extinguished without noise or sparks." CHAPTER XI. THE BALLOON IN THE SERVICE OF SCIENCE. At this point we must, for a brief while, drop the history of the famous aeronaut whose early career we have been briefly sketching in the last chapter, and turn our attention to a new feature of English ballooning. We have, at last, to record some genuinely scientific ascents, which our country now, all too tardily, instituted. It was the British Association that took the initiative, and the two men they chose for their purpose were both exceptionally qualified for the task they had in hand. The practical balloonist was none other than the veteran Charles Green, now in his sixty-seventh year, but destined yet to enjoy nearly twenty years more of life. The scientific expert was Mr. John Welsh, well fitted for the projected work by long training at Kew Observatory. The balloon which they used is itself worthy of mention, being the great Nassau Balloon of olden fame. Welsh was quick to realise more clearly than any former experimentalist that on account of the absence of breeze in a free balloon, as also on account of great solar radiation, the indications of thermometers would, without special precautions, be falsified. He therefore invented a form of aspirating thermometer, the earliest to be met with, and far in advance of any that were subsequently used by other scientists. It consisted of a polished tube, in which thermometers were enclosed, and through which a stream of air was forced by bellows. The difficulty of obtaining really accurate readings where thermometers are being quickly transported through varying temperatures is generally not duly appreciated. In the case of instruments carried m a balloon it should be remembered that the balloon itself conveys, clinging about it, no inconsiderable quantity of air, brought from other levels, while the temperature of its own mass will be liable to affect any thermometer in close neighbourhood. Moreover, any ordinary form of thermometer is necessarily sluggish in action, as may be readily noticed. If, for example, one be carried from a warm room to a cold passage, or vice versa it will be seen that the column moves very deliberately, and quite a long interval will elapse before it reaches its final position, the cause being that the entire instrument, with any stand or mounting that it may have, will have to adapt itself to the change of temperature before a true record will be obtained. This difficulty applies unavoidably to all thermometers in some degree, and the skill of instrument makers has been taxed to reduce the errors to a minimum. It is necessary, in any case, that a constant stream of surrounding air should play upon the instrument, and though this is most readily effected when instruments are carried aloft by kites, yet even thus it is thought that an interval of some minutes has to elapse before any form of thermometer will faithfully record any definite change of temperature. It is on this account that some allowance must be made for observations which will, in due place, be recorded of scientific explorers; the point to be borne in mind being that, as was mentioned in a former chapter, such observations will have to be regarded as giving readings which are somewhat too high in ascents and too low in descents. Two forms of thermometers at extremely simple construction, yet possessed of great sensibility, will be discussed in later chapters. The thermometers that Welsh used were undoubtedly far superior to any that were devised before his time and it is much to be regretted that they were allowed to fall into disuse. Perhaps the most important stricture on the observations that will have to be recorded is that the observers were not provided with a base station, on which account the value of results was impaired. It was not realised that it was necessary to make observations on the ground to compare with those that were being made at high altitudes. Welsh made, in all, four ascents in the summer and autumn of 1852 and in his report he is careful to give the highest praise to his colleague, Green, whose control over his balloon he describes as "so complete that none who accompanied him can be otherwise than relieved from all apprehension, and free to devote attention calmly to the work before him." The first ascent was made at 3.49 p.m. on August the 17th, under a south wind and with clouds covering some three-quarters of the sky. Welsh's first remark significant, and will be appreciated by anyone who has attempted observational work in a balloon. He states naively that "a short time was lost at first in an attempt to put the instruments into more convenient order, and also from the novelty of the situation." Then he mentions an observation which, in the experience of the writer, is a common one. The lowest clouds, which were about 2,500 feet high and not near the balloon, were passed without being noticed; other clouds were passed at different heights; and, finally, a few star-shaped crystals of snow; but the sun shone almost constantly. Little variation occurred in the direction of travel, which averaged thirty-eight miles an hour, and the descent took place at 5.20 p.m. at Swavesey, near Cambridge. The second ascent took place at 4.43 p.m. on August 26th, under a gentle east wind and a partially obscured sky. The clouds were again passed without being perceived. This was at the height of 3,000 feet, beyond which was very clear sky of deep blue. The air currents up to the limits of 12,000 feet set from varying directions. The descent occurred near Chesham at 7.45 p.m. The third ascent, at 2.35 p.m. on October the 21st was made into a sky covered with dense cloud masses lying within 3,000 and 3,700 feet. The sun was then seen shining through cirrus far up. The shadow of the balloon was also seen on the cloud, fringed with a glory, and about this time there was seen "stretching for a considerable length in a serpentine course, over the surface of the cloud, a well-defined belt, having the appearance of a broad road." Being now at 12,000 feet, Green thought it prudent to reconnoitre his position, and, finding they were near the sea, descended at 4.20 p.m. at Rayleigh, in Essex. Some important notes on the polarisation of the clouds were made. The fourth and final voyage was made in a fast wind averaging fifty knots from the north-east. Thin scud was met at 1,900 feet, and an upper stratum at 4,500 feet, beyond which was bright sun. The main shift of wind took place just as the upper surface of the first stratum was reached. In this ascent Welsh reached his greatest elevation, 22,930 feet, when both Green and himself experienced considerable difficulty in respiration and much fatigue. The sea being now perceived rapidly approaching, a hasty descent was made, and many of the instruments were broken. In summarising his results Welsh states that "the temperature of the air decreases uniformly with height above the earth's surface until at a certain elevation, varying on different days, decrease is arrested, and for the space of 2,000 or 3,000 feet the temperature remains nearly constant, or even increases, the regular diminution being again resumed and generally maintained at a rate slightly less rapid than in the lower part of the atmosphere, and commencing from a higher temperature than would have existed but for the interruption noticed." The analysis of the upper air showed the proportion of oxygen and nitrogen to vary scarcely more than at different spots on the earth. As it is necessary at this point to take leave of the veteran Green as a practical aeronaut, we may here refer to one or two noteworthy facts and incidents relating to his eventful career. In 1850 M. Poitevin is said to have attracted 140,000 people to Paris to look at an exhibition of himself ascending in a balloon seated on horseback, after which Madame Poitevin ascended from Cremorne Gardens in the same manner, the exhibition being intended as a representation of "Europa on a Bull." This, however, was discountenanced by the authorities and withdrawn. The feats were, in reality, merely the repetitions of one that had been conceived and extremely well carried out by Green many years before--as long ago, in fact, as 1828, when he arranged to make an ascent from the Eagle Tavern, City Road, seated on a pony. To carry out his intention, he discarded the ordinary car, replacing it with a small platform, which was provided with places to receive the pony's feet; while straps attached to the hoop were passed under the animal's body, preventing it from lying down or from making any violent movement. This the creature seemed in no way disposed to attempt, and when all had been successfully carried out and an easy descent effected at Beckenham, the pony was discovered eating a meal of beans with which it had been supplied. Several interesting observations have been recorded by Green on different occasions, some of which are highly instructive from a practical or scientific point of view. On an ascent from Vauxhall, in which he was accompanied by his friend Spencer and Mr. Rush, he recorded how, as he constantly and somewhat rapidly rose, the wind changed its direction from N.W. through N. to N.E., while he remained over the metropolis, the balloon all the while rotating on its axis. This continual swinging or revolving of the balloon Green considers an accompaniment of either a rapid ascent or descent, but it may be questioned whether it is not merely a consequence of changing currents, or, sometimes, of an initial spin given inadvertently to the balloon at the moment of its being liberated. The phenomenon of marked change which he describes in the upper currents is highly interesting, and tallies with what the writer has frequently experienced over London proper. Such higher currents may be due to natural environment, and to conditions necessarily prevailing over so vast and varied a city, and they may be able to play an all-important part in the dispersal of London smoke or fog. This point will be touched on later. In this particular voyage Green records that as he was rising at the moment when his barometer reached 19 inches, the thermometer he carried registered 46 degrees, while on coming down, when the barometer again marked 19 inches, the same thermometer recorded only 22 degrees. It will not fail to be recognised that there is doubtless here an example of the errors alluded to above, inseparable from readings taken in ascent and descent. A calculation made by Green in his earlier years has a certain value. By the time he had accomplished 200 ascents he was at pains to compute that he had travelled across country some 6,000 miles, which had been traversed in 240 hours. From this it would follow that the mean rate of travel in aerial voyages will be about twenty-five miles per hour. Towards the end of his career we find it stated by Lieutenant G. Grover, R.E., that "the Messrs. Green, Father and Son, have made between them some 930 ascents, in none of which have they met with any material accident or failure." This is wonderful testimony, indeed, and we may here add the fact that the father took up his own father, then at the age of eighty-three, in a balloon ascent of 1845, without any serious consequences. But it is time that some account should be given of a particular occasion which at least provided the famous aeronaut with an adventure spiced with no small amount of risk. It was on the 5th of July, 1850, that Green ascended, with Rush as his companion, from Vauxhall, at the somewhat late hour of 7.50 p.m., using, as always, the great Nassau balloon. The rate of rise must have been very considerable, and they presently record an altitude of no less than 20,000 feet, and a temperature of 12 degrees below freezing. They were now above the clouds, where all view of earth was lost, and, not venturing to remain long in this situation, they commenced a rapid descent, and on emerging below found themselves sailing down Sea Reach in the direction of Nore Sands, when they observed a vessel. Their chance of making land was, to say the least, uncertain, and Green, considering that his safety lay in bespeaking the vessel's assistance, opened the valve and brought the car down in the water some two miles north of Sheerness, the hour being 8.45, and only fifty-five minutes since the start. The wind was blowing stiffly, and, catching the hollow of the half-inflated balloon, carried the voyagers rapidly down the river, too fast, indeed, to allow of the vessel's overtaking them. This being soon apparent, Green cast out his anchor, and not without result, for it shortly became entangled in a sunken wreck, and the balloon was promptly "brought up," though struggling and tossing in the broken water. A neighbouring barge at once put off a boat to the rescue, and other boats were despatched by H.M. cutter Fly, under Commander Gurling. Green and Rush were speedily rescued, but the balloon itself was too restive and dangerous an object to approach with safety. At Green's suggestion, therefore, a volley of musketry was fired into the silk' after which it became possible to pass a rope around it and expel the gas. Green subsequently relates how it took a fortnight to restore the damage, consisting of sixty-two bullet rents and nineteen torn gores. Green's name will always be famous, if only for the fact that it was he who first adopted the use of coal gas in his calling. This, it will be remembered, was in 1821, and it should be borne in mind that at that time household gas had only recently been introduced. In point of fact, it first lighted Pall Mall in 1805, and it was not used for the general lighting of London till 1814. We are not surprised to find that the great aeronaut at one time turned his attention to the construction of models, and this with no inconsiderable success. A model of his was exhibited in 1840 at the Polytechnic Institution, and is described in the Times as consisting of a miniature balloon of three feet diameter, inflated with coal gas. It was acted on by fans, which were operated by mechanism placed in the car. A series of three experiments was exhibited. First, the balloon being weighted so as to remain poised in the still air of the building, the mechanism was started, and the machine rose steadily to the ceiling. The fans were then reversed, when the model, equally gracefully, descended to the floor. Lastly, the balloon, with a weighted trail rope, being once more balanced in mid-air, the fans were applied laterally, when the machine would take a horizontal flight, pulling the trail rope after it, with an attached weight dragging along the floor until the mechanism had run down, when it again remained stationary. The correspondent of the Times continues, "Mr. Green states that by these simple means a voyage across the Atlantic may be performed in three or four days, as easily as from Vauxhall Gardens to Nassau." We can hardly attribute this statement seriously to one who knew as well as did Green how fickle are the winds, and how utterly different are the conditions between the still air of a room and those of the open sky. His insight into the difficulties of the problem cannot have been less than that of his successor, Coxwell, who, as the result of his own equally wide experience, states positively, "I could never imagine a motive power of sufficient force to direct and guide a balloon, much less to enable a man or a machine to fly." Even when modern invention had produced a motive power undreamed of in the days we are now considering, Coxwell declares his conviction that inherent difficulties would not be overcome "unless the air should invariably remain in a calm state." It would be tedious and scarcely instructive to inquire into the various forms of flying machines that were elaborated at this period; but one that was designed in America by Mr. Henson, and with which it was seriously contemplated to attempt to cross the Atlantic, may be briefly described. In theory it was supposed to be capable of being sustained in the air by virtue of the speed mechanically imparted to it, and of the angle at which its advancing under surface would meet the air. The inventor claimed to have produced a steam engine of extreme lightness as well as efficiency, and for the rest his machine consisted of a huge aero-plane propelled by fans with oblique vanes, while a tail somewhat resembling that of a bird was added, as also a rudder, the functions of which were to direct the craft vertically and horizontally respectively. Be it here recorded that the machine did not cross the Atlantic. One word as to the instruments used up to this time for determining altitudes. These were, in general, ordinary mercurial barometers, protected in various ways. Green encased his instrument in a simple metal tube, which admitted of the column of mercury being easily read. This instrument, which is generally to be seen held in his hand in Green's old portraits, might be mistaken for a mariner's telescope. It is now in the possession of the family of Spencers, the grandchildren of his old aeronautical friend and colleague, and it is stated that with all his care the glass was not infrequently broken in a descent. Wise, with characteristic ingenuity, devised a rough-and-ready height instrument, which he claims to have answered well. It consisted simply of a common porter bottle, to the neck of which was joined a bladder of the same capacity. The bottle being filled with air of the density of that on the ground, and the bladder tied on in a collapsed state, the expansion of the air in the bottle would gradually fill the bladder as it rose into the rarer regions of the atmosphere. Experience would then be trusted to enable the aeronaut to judge his height from the amount of inflation noticeable in the bladder. CHAPTER XII. HENRY COXWELL AND HIS CONTEMPORARIES. Mention should be made in these pages of a night sail of a hundred miles, boldly carried out in 1849 by M. Arban, which took the voyager from Marseilles to Turin fairly over the Alps. The main summit was reached at 11 p.m., when the "snow, cascades, and rivers were all sparkling under the moon, and the ravines and rocks produced masses of darkness which served as shadows to the gigantic picture." Arban was at one time on a level with the highest point of Mont Blanc, the top of which, standing out well above the clouds, resembled "an immense block of crystal sparkling with a thousand fires." In London, in the year of the Great Exhibition, and while the building was still standing in Hyde Park, there occurred a balloon incident small in itself, but sufficient to cause much sensation at the crowded spot where it took place. The ascent was made from the Hippodrome by Mr. and Mrs. Graham in very boisterous weather, and, on being liberated, the balloon seems to have fouled a mast, suffering a considerable rent. After this the aeronauts succeeded in clearing the trees in Kensington Gardens, and in descending fairly in the Park, but, still at the mercy of the winds, they were carried on to the roof of a house in Arlington Street, and thence on to another in Park Place, where, becoming lodged against a stack of chimneys, they were eventually rescued by the police without any material damage having been done. But this same summer saw the return to England of Henry Coxwell, and for some years the story of the conquest of the air is best told by following his stirring career, and his own comments on aeronautical events of this date. We find him shortly setting about carrying out some reconnoitring and signalling experiments, designed to be of use in time of war. This was an old idea of his, and one which had, of course, been long entertained by others, having, indeed, been put to some practical test in time of warfare. It will be well to make note of what attention the matter had already received, and of what progress had been made both in theory and practice. We have already made some mention in Chapter IV. of the use which the French had made of balloons in their military operations at the end of the eighteenth and beginning of nineteenth the century. It was, indeed, within the first ten years after the first invention of the balloon that, under the superintendence of the savants of the French Academy, a practical school of aeronautics was established at Meudon. The names of Guyton, De Morveau (a distinguished French chemist), and Colonel Coutelle are chiefly associated with the movement, and under them some fifty students received necessary training. The practising balloon had a capacity of 17,000 cubic feet, and was inflated with pure hydrogen, made by what was then a new process as applied to ballooning, and which will be described in a future chapter. It appears that the balloon was kept always full, so that any opportunity of calm weather would be taken advantage of for practice. And it is further stated that a balloon was constructed so sound and impervious that after the lapse of two months it was still capable, without being replenished, of raising into the air two men, with necessary ballast and equipment. The practical trial for the balloon in real service came off in June, 1794, when Coutelle in person, accompanied by two staff officers, in one of the four balloons which the French Army had provided, made an ascent to reconnoitre the Austrian forces at Fleurus. They ascended twice in one day, remaining aloft for some four hours, and, on their second ascent being sighted, drew a brisk fire from the enemy. They were unharmed, however, and the successful termination of the battle of Fleurus has been claimed as due in large measure to the service rendered by that balloon. The extraordinary fact that the use of the balloon was for many years discontinued in the French Army is attributed to a strangely superstitious prejudice entertained by Napoleon. Las Cases (in his "Private Life of Napoleon at St. Helena ") relates an almost miraculous story of Napoleon's coronation. It appears that a sum of 23,500 francs was given to M. Garnerin to provide a balloon ascent to aid in the celebrations, and, in consequence, a colossal machine was made to ascend at 11 p.m. on December 16th from the front of Notre Dame, carrying 3,000 lights. This balloon was unmanned, and at its departure apparently behaved extremely well, causing universal delight. During the hours of darkness, however, it seems to have acquitted itself in a strange and well-nigh preternatural manner, for at daybreak it is sighted on the horizon by the inhabitants of Rome, and seen to be coming towards their city. So true was its course that, as though with predetermined purpose, it sails on till it is positively over St. Peter's and the Vatican, when, its mission being apparently fulfilled, it settles to earth, and finally ends its career in the Lake Bracciano. Regarded from whatever point of view, the flight was certainly extraordinary, and it is not surprising that in that age it was regarded as nothing less than a portent. Moreover, little details of the wonderful story were quickly endowed with grave significance. The balloon on reaching the ground rent itself. Next, ere it plunged into the water, it carefully deposited a portion of its crown on the tomb of Nero. Napoleon, on learning the facts, forbade that they should ever be referred to. Further, he thenceforward discountenanced the balloon in his army, and the establishment at Meudon was abandoned. There is record of an attempt of some sort that was made to revive the French military ballooning school in the African campaign of 1830, but it was barren of results. Again, it has been stated that the Austrians used balloons for reconnaissance, before Venice in 1849, and yet again the same thing is related of the Russians at the time of the siege of Sebastopol, though Kinglake does not mention the circumstance. In 1846 Wise drew up and laid before the American War Office an elaborate scheme for the reduction of Vera Cruz. This will be discussed in its due place, though it will be doubtless considered as chimerical. On the other hand, eminently practical were the experiments co-ordinated and begun to be put to an actual test by Mr. Coxwell, who, before he could duly impress his project upon the military authorities, had to make preliminary trials in private ventures. The earliest of these was at the Surrey Zoological Gardens in the autumn of 1854, and it will be granted that much ingenuity and originality were displayed when it is considered that at that date neither wireless telegraphy, electric flashlight, nor even Morse Code signalling was in vogue. According to his announcement, the spectators were to regard his balloon, captive or free, as floating at a certain altitude over a beleaguered fortress, the authorities in communication with it having the key of the signals and seeking to obtain through these means information as to the approach of an enemy. It was to be supposed that, by the aid of glasses, a vast distance around could be subjected to careful scrutiny, and a constant communication kept up with the authorities in the fortress. Further, the flags or other signals were supposed preconcerted and unknown to the enemy, being formed by variations of shape and colour. Pigeons were also despatched from a considerable height to test their efficiency under novel conditions. The public press commented favourably on the performance and result of this initial experiment. Mr. Coxwell's account of an occasion when he had to try conclusions with a very boisterous wind, and of the way in which he negotiated a very trying and dangerous landing, will be found alike interesting and instructive. It was an ascent from the Crystal Palace, and the morning was fair and of bright promise outwardly; but Coxwell confesses to have disregarded a falling glass. The inflation having been progressing satisfactorily, he retired to partake of luncheon, entirely free from apprehensions; but while thus occupied, he was presently sought out and summoned by a gardener, who told him that his balloon had torn away, and was now completely out of control, dragging his men about the bushes. On reaching the scene, the men, in great strength, were about to attempt a more strenuous effort to drag the balloon back against the wind, which Coxwell promptly forbade, warning them that so they would tear all to pieces. He then commenced, as it were, to "take in a reef," by gathering in the slack of the silk, which chiefly was catching the wind, and by drawing in the net, mesh by mesh, until the more inflated portion of the balloon was left snug and offering but little resistance to the gale, when he got her dragged in a direction slanting to the wind and under the lee of trees. Eventually a hazardous and difficult departure was effected, Mr. Chandler, a passenger already booked, insisting on accompanying the aeronaut, in spite of the latter's strongest protestations. And their first peril came quickly, in a near shave of fouling the balcony of the North Tower, which they avoided only by a prompt discharge of sand, the crowd cheering loudly as they saw how the crisis was avoided. The car, adds Mr. Coxwell in his memoirs, "was apparently trailing behind the balloon with a pendulous swing, which is not often the case... In less than two minutes we entered the lower clouds, passing through them quickly, and noticing that their tops, which are usually of white, rounded conformation, were torn into shreds and crests of vapour. Above, there was a second wild-looking stratum of another order. We could hear, as we hastened on, the hum of the West End of London; but we were bowling along, having little time to look about us, though some extra sandbags were turned to good account by making a bed of them at the bottom ends of the car, which we occupied in anticipation of a rough landing." As it came on to rain hard the voyagers agreed to descend, and Coxwell, choosing open ground, succeeded in the oft-attempted endeavour to drop his grapnel in front of a bank or hedge-row. The balloon pulled up with such a shock as inevitably follows when flying at sixty miles an hour, and Mr. Coxwell continues:--"We were at this time suspended like a kite, and it was not so much the quantity of gas which kept us up as the hollow surface of loose silk, which acted like a falling kite, and the obvious game of skill consisted in not letting out too much gas to make the balloon pitch heavily with a thud that would have been awfully unpleasant; but to jockey our final touch in a gradual manner, and yet to do it as quickly as possible for fear of the machine getting adrift, since, under the peculiar circumstances in which we were placed, it would have inevitably fallen with a crushing blow, which might have proved fatal. I never remember to have been in a situation when more coolness and nicety were required to overcome the peril which here beset us; while on that day the strong wind was, strange as it may sound, helping us to alight easily, that is to say as long as the grapnel held fast and the balloon did not turn over like an unsteady kite." Such peril as there was soon terminated without injury to either voyager. The same remark will apply to an occasion when Coxwell was caught in a thunderstorm, which he thus describes in brief:--"On a second ascent from Chesterfield we were carried into the midst of gathering clouds, which began to flash vividly, and in the end culminated in a storm. There were indications, before we left the earth, as to what might be expected. The lower breeze took us in another direction as we rose, but a gentle, whirling current higher up got us into the vortex of a highly charged cloud.... We had to prove by absolute experience whether the balloon was insulated and a non-conductor. Beyond a drenching, no untoward incident occurred during a voyage lasting in all three-quarters of an hour." A voyage which Coxwell (referring, doubtless, to aerial travel over English soil only) describes as "being so very much in excess of accustomary trips in balloons" will be seen to fall short of one memorable voyage of which the writer will have to give his own experiences. Some account, however, of what the famous aeronaut has to tell will find a fitting place here. It was an ascent on a summer night from North Woolwich, and on this occasion Coxwell was accompanied by two friends, one being Henry Youens, who subsequently became a professional balloonist of considerable repute, and who at this time was an ardent amateur. It was half an hour before midnight when the party took their places, and, getting smartly away from the crowd in the gala grounds, shot over the river, and shortly were over the town of Greenwich with the lights of London well ahead. Then their course took them over Kennington Oval, Vauxhall Bridge, and Battersea, when they presently heard the strains of a Scotch polka. This came up from the then famous Gardens of Cremorne, and, the breeze freshening, it was but a few minutes later when they stood over Kingston, by which time it became a question whether, being now clear of London, they should descend or else live out the night and take what thus might come their way. This course, as the most prudent, as well as the most fascinating, was that which commended itself, and at that moment the hour of midnight was heard striking, showing that a fairly long distance had been covered in a short interval of time. From this period they would seem to have lost their way, and though scattered lights were sighted ahead, they were soon in doubt as to whether they might not already be nearing the sea, a doubt that was strengthened by their hearing the cry of sea-fowl. After a pause, lights were seen looming under the haze to sea-ward, which at times resembled water; and a tail like that of a comet was discerned, beyond which was a black patch of considerable size. The patch was the Isle of Wight, and the tail the Water from Southampton. They were thus wearing more south and towards danger. They had no Davy lamp with which to read their aneroid, and could only tell from the upward flight of fragments of paper that they were descending. Another deficiency in their equipment was the lack of a trail rope to break their fall, and for some time they were under unpleasant apprehension of an unexpected and rude impact with the ground, or collision with some undesirable object. This induced them to discharge sand and to risk the consequences of another rise into space, and as they mounted they were not reassured by sighting to the south a ridge of lighter colour, which strongly suggested the coast line. But it was midsummer, and it was not long before bird life awakening was heard below, and then a streak of dawn revealed their locality, which was over the Exe, with Sidmouth and Tor Bay hard by on their left. Then from here, the land jutting seawards, they confidently traversed Dartmoor, and effected a safe, if somewhat unseasonable, descent near Tavistock. The distance travelled was considerable, but the duration, on the aeronaut's own showing, was less than five hours. In the year 1859 the Times commented on the usefulness of military balloons in language that fully justified all that Coxwell had previously claimed for them. A war correspondent, who had accompanied the Austrian Army during that year, asks pertinently how it had happened that the French had been ready at six o'clock to make a combined attack against the Austrians, who, on their part, had but just taken up positions on the previous evening. The correspondent goes on to supply the answer thus:--"No sooner was the first Austrian battalion out of Vallegio than a balloon was observed to rise in the air from the vicinity of Monsambano--a signal, no doubt, for the French in Castiglione. I have a full conviction that the Emperor of the French knew overnight the exact position of every Austrian corps, while the Emperor of Austria was unable to ascertain the number or distribution of the forces of the allies." It appears that M. Godard was the aeronaut employed to observe the enemy, and that fresh balloons for the French Army were proceeded with. The date was now near at hand when Coxwell, in partnership with Mr. Glaisher, was to take part in the classical work which has rendered their names famous throughout the world. Before proceeding to tell of that period, however, Mr. Coxwell has done well to record one aerial adventure, which, while but narrowly missing the most serious consequences, gives a very practical illustration of the chances in favour of the aeronaut under extreme circumstances. It was an ascent at Congleton in a gale of wind, a and the company of two passengers--Messrs. Pearson, of Lawton Hall--was pressed upon him. Everything foretold a rough landing, and some time after the start was made the outlook was not improved by the fact that the dreaded county of Derbyshire was seen approaching; and it was presently apparent that the spot on which they had decided to descend was faced by rocks and a formidable gorge. On this, Coxwell attempted to drop his grapnel in front of a stone wall, and so far with success; but the wall went down, as also another and another, the wicker car passing, with its great impetus, clean through the solid obstacles, till at last the balloon slit from top to bottom. Very serious injuries to heads and limbs were sustained, but no lives were lost, and Coxwell himself, after being laid up at Buxton, got home on crutches. CHAPTER XIII. SOME NOTEWORTHY ASCENTS. It was the year 1862, and the scientific world in England determined once again on attempting observational work in connection with balloons. There had been a meeting of the British Association at Wolverhampton, and, under their auspices, and with the professional services of Thomas Lythgoe, Mr. Creswick, of Greenwich Observatory, was commissioned to make a lofty scientific ascent with a Cremorne balloon. The attempt, however, was unsatisfactory; and the balloon being condemned, an application was made to Mr. Coxwell to provide a suitable craft, and to undertake its management. The principals of the working committee were Colonel Sykes, M.P., Dr. Lee, and Mr. James Glaisher, F.R.S., and a short conference between these gentlemen and the experienced aeronaut soon made it clear that a mammoth balloon far larger than any in existence was needed for the work in hand. But here a fatal obstacle presented itself in lack of funds, for it transpired that the grant voted was only to be devoted to trial ascents. It was then that Mr. Coxwell, with characteristic enterprise, undertook, at his own cost, to build a suitable balloon, and, moreover, to have it ready by Midsummer Day. It was a bold, as well as a generous, offer; for it was now March, and, according to Mr. Coxwell's statement, if silk were employed, the preparation and manufacture would occupy six months and cost not less than L2,000. The fabric chosen was a sort of American cloth, and by unremitting efforts the task was performed to time, and the balloon forwarded to Wolverhampton, its dimensions being 55 feet in diameter, 80 feet in height from the ground, with a capacity of 93,000 cubic feet. But the best feature in connection with it was the fact that Mr. Glaisher himself was to make the ascents as scientific observer. No time was lost in getting to work, but twice over the chosen days were unsuitable, and it was not till July 17th that the two colleagues, of whom so much is to be told, got away at 9.30 a.m. with their balloon only two-thirds full, to allow of expansion to take place in such a lofty ascent as was contemplated. And, when it is considered that an altitude of five miles was reached, it will be granted that the scientific gentleman who was making his maiden ascent that day showed remarkable endurance and tenacity of purpose--the all-important essential for the onerous and trying work before him. At 9.56 the balloon had disappeared from sight, climbing far into the sky in the E.N.E. The story of the voyage we must leave in Mr. Glaisher's hands. Certain events, however, associated with other aeronauts, which had already happened, and which should be considered in connection with the new drama now to be introduced, may fittingly here meet with brief mention. The trouble arising from the coasting across country of a fallen and still half-inflated balloon has already been sufficiently illustrated, and needs little further discussion. It is common enough to see a balloon, when full and round, struggling restively under a moderate breeze with a score of men, and dragging them, and near a ton of sand-bags as well, about the starting ground. But, as has already been pointed out, the power of the wind on the globe is vastly increased when the silk becomes slack and forms a hollow to hold the wind, like a bellying sail. Various means to deal with this difficulty have been devised, one of these being an emergency, or ripping valve, in addition to the ordinary valve, consisting of an arrangement for tearing a large opening in the upper part of one of the gores, so that on reaching earth the balloon may be immediately crippled and emptied of so large a quantity of gas as to render dragging impossible. Such a method is not altogether without drawbacks, one of these being the confusion liable to arise from there being more than one valve line to reckon with. To obviate this, it has been suggested that the emergency line should be of a distinctive colour. But an experiment with a safeguard to somewhat of this nature was attended with fatal consequence in the year 1824. A Mr. Harris, a lieutenant in the British Navy, ascended from the Eagle Tavern, City Road, with a balloon fitted with a contrivance of his own invention, consisting of a large hinged upper valve, having within it a smaller valve of the same description, the idea being that, should the operation of the smaller outlet not suffice for any occasion, then the shutter of the larger opening might be resorted to, to effect a more liberal discharge of gas. Mr. Harris took with him a young lady, Miss Stocks by name, and apparently the afternoon--it being late May--was favourable for an aerial voyage; for, with full reliance on his apparatus, he left his grapnel behind, and was content with such assistance as the girl might be able to render him. It was not long before the balloon was found descending, and with a rapidity that seemed somewhat to disturb the aeronaut; and when, after a re-ascent, effected by a discharge of ballast, another decided downward tendency ensued, Mr. Harris clearly realised that something was wrong, without, however, divining the cause. The story subsequently told by the girl was to the effect that when the balloon was descending the second time she was spoken to by her unfortunate companion in an anxious manner. "I then heard the balloon go 'Clap! clap!' and Mr. Harris said he was afraid it was bursting, at which I fainted, and knew no more until I found myself in bed." A gamekeeper tells the sequel, relating that he observed the balloon, which was descending with great velocity, strike and break the head of an oak tree, after which it also struck the ground. Hurrying up, he found the girl insensible, and Mr. Harris already dead, with his breast bone and several ribs broken. The explanation of the accident given by Mr. Edward Spencer is alike convincing and instructive. This eminently practical authority points out that the valve lines must have been made taut to the hoop at the time that the balloon was full and globular. Thus, subsequently, when from diminution of gas the balloon's shape elongated, the valve line would become strained and begin to open the valve, but in such a gradual manner as to escape the notice of the aeronaut. Miss Stocks, far from being unnerved by the terrible experience, actually made three subsequent ascents in company with Mr. Green. It deserves mention that another disaster, equally instructive, but happily not attended with loss of life, occurred in Dublin in 1844 to Mr. Hampton, who about this time made several public and enterprising voyages. He evidently was possessed of admirable nerve and decision, and did not hesitate to make an ascent from the Porto-Bello Gardens in face of strong wind blowing sea-wards, and in spite of many protestations from the onlookers that he was placing himself in danger. This danger he fully realised, more particularly when he recognised that the headland on which he hoped to alight was not in the direction of the wind's course. Resolved, however, on gratifying the crowd, Mr. Hampton ascended rapidly, and then with equal expedition commenced a precipitate descent, which he accomplished with skill and without mishap. But the wind was still boisterous, and the balloon sped onward along the ground towards fresh danger unforeseen, and perhaps not duly reckoned with. Ahead was a cottage, the chimney of which was on fire. A balloonist in these circumstances is apt to think little of a single small object in his way, knowing how many are the chances of missing or of successfully negotiating any such obstacle. The writer on one occasion was, in the judgment of onlookers below, drifting in dangerous proximity to the awful Cwmavon stack in Glamorganshire, then in full blast; yet it was a fact that that vast vent of flame and smoke passed almost unheeded by the party in the descending car. It may have been thus, also, with Mr. Hampton, who only fully realised his danger when his balloon blew up "with an awfully grand explosion," and he was reduced to the extremity of jumping for his life, happily escaping the mass of burning silk and ropes. The awful predicament of falling into the sea, which has been illustrated already, and which will recur again in these pages, was ably and successfully met by Mr. Cunningham, who made an afternoon ascent from the Artillery Barracks at Clevedon, reaching Snake Island at nightfall, where, owing to the gathering darkness, he felt constrained to open his valve. He quickly commenced descending into the sea, and when within ten feet of the water, turned the "detaching screw" which connected the car with the balloon. The effect of this was at once to launch him on the waves, but, being still able to keep control over the valve, he allowed just enough gas to remain within the silk to hold the balloon above water. He then betook himself to the paddles with which his craft was provided, and reached Snake Island with the balloon in tow. Here he seems to have found good use for a further portion of his very complete equipment; for, lighting a signal rocket, he presently brought a four-oared gig to his succour from Portsmouth Harbour. The teaching of the above incident is manifest enough. If it should be contemplated to use the balloon for serious or lengthened travel anywhere within possible reach of the sea-board--and this must apply to all parts of the British Isles--it must become a wise precaution, if not an absolute necessity, to adopt some form of car that would be of avail in the event of a fall taking place in the sea. Sufficient confirmation of this statement will be shortly afforded by a memorable voyage accomplished during the partnership of Messrs. Glaisher and Coxwell, one which would certainly have found the travellers in far less jeopardy had their car been convertible into a boat. We have already seen how essential Wise considered this expedient in his own bolder schemes, and it may further be mentioned here that modern air ships have been designed with the intention of making the water a perfectly safe landing. The ballooning exploits which, however, we have now to recount had quite another and more special object consistently in view--that of scientific investigation; and we would here premise that the proper appreciation of these investigations will depend on a due understanding of the attendant circumstances, as also of the constant characteristic behaviour of balloons, whether despatched for mere travel or research. First let us regard the actual path of a balloon in space when being manoeuvred in the way we read of in Mr. Glaisher's own accounts. This part is in most cases approximately indicated in that most attractive volume of his entitled, "Travels in the Air," by diagrams giving a sectional presentment of his more important voyages; but a little commonplace consideration may take the place of diagrams. It has been common to assert that a balloon poised in space is the most delicate balance conceivable. Its intrinsic weight must be exactly equal to the weight of the air it displaces, and since the density of the air decreases according to a fixed law, amounting, approximately, to a difference in barometric reading of 0.1 inch for every 90 feet, it follows, theoretically, that if a balloon is poised at 1,000 feet above sea level, then it would not be in equilibrium at any other height, so long as its weight and volume remain the same. If it were 50 feet higher it must commence descending, and, if lower, then it must ascend till it reaches its true level; and, more than that, in the event of either such excursion mere impetus would carry it beyond this level, about which it would oscillate for a short time, after the manner of the pendulum. This is substantially true, but it must be taken in connection with other facts which have a far greater influence on a balloon's position or motion. For instance, in the volume just referred to it is stated by M. Gaston Tissandier that on one occasion when aloft he threw overboard a chicken bone, and, immediately consulting a barometer, had to admit on "clearest evidence that the bone had caused a rise of from twenty to thirty yards, so delicately is a balloon equipoised in the air." Here, without pausing to calculate whether the discharge of an ounce or so would suffice to cause a large balloon to ascend through ninety feet, it may be pointed out that the record cannot be trustworthy, from the mere fact that a free balloon is from moment to moment being subjected to other potent influences, which necessarily affect its position in space. In daytime the sun's influence is an all-important factor, and whether shining brightly or partially hidden by clouds, a slight difference in obscuration will have a ready and marked effect on the balloon's altitude. Again, a balloon in transit may pass almost momentarily from a warmer layer of air to a colder, or vice versa, the plane of demarcation between the two being very definite and abrupt, and in this case altitude is at once affected; or, yet again, there are the descending and ascending currents, met with constantly and unexpectedly, which have to be reckoned with. Thus it becomes a fact that a balloon's vertical course is subjected to constant checks and vicissitudes from a variety of causes, and these will have to be duly borne in mind when we are confronted with the often surprising results and readings which are supplied by scientific observers. With regard to the close proximity, without appreciable intermingling, of widely differing currents, it should be mentioned that explorers have found in regions where winds of different directions pass each other that one air stream appears actually to drag against the surface of the other, as though admitting no interspace where the streams might mingle. Indeed, trustworthy observers have stated that even a hurricane can rage over a tranquil atmosphere with a sharply defined surface of demarcation between calm and storm. Thus, to quote the actual words of Charles Darwin, than whom it is impossible to adduce a more careful witness, we find him recording how on mountain heights he met with winds turbulent and unconfined, yet holding courses "like rivers within their beds." It is in tracing the trend of upper air streams, to whose wayward courses and ever varying conditions we are now to be introduced, that much of our most valuable information has come, affecting the possibility of forecasting British wind and weather. It should need no insisting on that the data required by meteorologists are not sufficiently supplied by the readings of instruments placed on or near the ground, or by the set of the wind as determined by a vane planted on the top of a pole or roof of a building. The chief factors in our meteorology are rather those broader and deeper conditions which obtain in higher regions necessarily beyond our ken, until those regions are duly and diligently explored. Mr. Glaisher's estimate of the utility of the balloon as an instrument of research, formed at the conclusion of his aeronautical labours, has a special value and significance. Speaking with all the weight attaching to so trained and eminent an observer, he declares, "The balloon, considered as an instrument for vertical exploration, presents itself to us under a variety of aspects, each of which is fertile in suggestions. Regarding the atmosphere as the great laboratory of changes which contain the germ of future dis discoveries, to belong respectively, as they unfold, to the chemist and meteorologist, the physical relation to animal life of different heights, the form of death which at certain elevations waits to accomplish its destruction, the effect of diminished pressure upon individuals similarly placed, the comparison of mountain ascents with the experiences of aeronauts, are some of the questions which suggest themselves and faintly indicate enquiries which naturally ally themselves to the course of balloon experiments. Sufficiently varied and important, they will be seen to rank the balloon as a valuable aid to the uses of philosophy, and rescue it from the impending degradation of continuing a toy fit only to be exhibited or to administer to the pleasures of the curious and lovers of adventure." The words of the same authority as to the possible practical development of the balloon as an aerial machine should likewise be quoted, and will appear almost prophetic. "In England the subject of aero-station has made but little progress, and no valuable invention has arisen to facilitate travelling in the air. In all my ascents I used the balloon as I found it. The desire which influenced me was to ascend to the higher regions and travel by its means in furtherance of a better knowledge of atmospheric phenomena. Neither its management nor its improvement formed a part of my plan. I soon found that balloon travelling was at the mercy of the wind, and I saw no probability of any method of steering balloons being obtained. It even appeared to me that the balloon itself, admirable for vertical ascents, was not necessarily a first step in aerial navigation, and might possibly have no share in the solution of the problem. It was this conviction that led to the formation of the Aeronautical Society a few years since under the presidency of the Duke of Argyll. In the number of communications made to this society it is evident that many minds are taxing their ingenuity to discover a mode of navigating the air; all kinds of imaginary projects have been suggested, some showing great mechanical ingenuity, but all indicating the want of more knowledge of the atmosphere itself. The first great aim of this society is the connecting the velocity of the air with its pressure on plane surfaces at various inclinations. "There seems no prospect of obtaining this relation otherwise than by a careful series of experiments." CHAPTER XIV. THE HIGHEST ASCENT ON RECORD. Mr. Glaisher's instrumental outfit was on an elaborate and costly scale, and the programme of experimental work drawn up for him by the Committee of the British Association did not err on the side of too much modesty. In the first place the temperature and moisture of the atmosphere were to be examined. Observations on mountain sides had determined that thermometers showed a decrease of 1 degree F. for every 300 feet, and the accuracy of this law was particularly to be tested. Also, investigations were to be made as to the distribution of vapour below the clouds, in them, and above them. Then careful observations respecting the dew point were to be undertaken at all accessible heights, and, more particularly, up to those heights where man may be resident or troops may be located. The comparatively new instrument, the aneroid barometer, extremely valuable, if only trustworthy, by reason of its sensibility, portability and safety, was to be tested and compared with the behaviour of a reliable mercurial barometer. Electrical conditions were to be examined; the presence of ozone tested; the vibration of a magnet was again to be resorted to to determine how far the magnetism of the earth might be affected by height. The solar spectrum was to be observed; air was to be collected at different heights for analysis; clouds, also upper currents, were to be reported on. Further observations were to be made on sound, on solar radiation, on the actinic action of the sun, and on atmospheric phenomena in general. All this must be regarded as a large order where only a very limited number of ascents were contemplated, and it may be mentioned that some of the methods of investigation, as, for instance, the use of ozone papers, would now be generally considered obsolete; while the mechanical aspiration of thermometers by a stream of air, which, as we have pointed out, was introduced by Welsh, and which is strongly insisted on at the present day, was considered unnecessary by Mr. Glaisher in the case of wet and dry bulb hygrometers. The entire list of instruments, as minutely described by the talented observer, numbered twenty-two articles, among which were such irreproachable items as a bottle of water and a pair of scissors. The following is a condensed account, gathered from Mr. Glaisher's own narrative, of his first ascent, which has been already briefly sketched in these pages by the hand of Mr. Coxwell. Very great difficulties were experienced in the inflation, which operation appeared as if it would never be completed, for a terrible W.S.W. wind was constantly blowing, and the movements of the balloon were so great and so rapid that it was impossible to fix a single instrument in its position before quitting the earth, a position of affairs which, says Mr. Glaisher, "was by no means cheering to a novice who had never before put his foot in the car of a balloon," and when, at last, at 9.42 a.m., Mr. Coxwell cast off, there was no upward motion, the car simply dragging on its side till the expiration of a whole minute, when the balloon lifted, and in six minutes reached the first cloud at an altitude of 4,467 feet. This cloud was passed at 5,802 feet, and further cloud encountered at 2,000 feet further aloft. Four minutes later, the ascent proceeding, the sun shone out brightly, expanding the balloon into a perfect globe and displaying a magnificent view, which, however, the incipient voyager did not allow himself to enjoy until the instruments were arranged in due order, by which time a height of 10,000 feet was recorded. Mr. Glaisher apparently now had opportunity for observing the clouds, which he describes as very beautiful, and he records the hearing of a band of music at a height of 12,709 feet, which was attained in exactly twenty minutes from the start. A minute later the earth was sighted through a break in the clouds, and at 16,914 feet the clouds were far below, the sky above being perfectly cloudless, and of an intense Prussian blue. By this time Mr. Glaisher had received his first surprise, as imparted by the record of his instruments. At starting, the temperature of the air had stood at 59 degrees. Then at 4,000 feet this was reduced to 45 degrees; and, further, to 26 degrees at 10,000 feet, when it remained stationary through an ascent of 3,000 feet more, during which period both travellers added to their clothing, anticipating much accession of cold. However, at 15,500 feet the temperature had actually risen to 31 degrees, increasing to no less than 42 degrees at 19,500 feet. Astonishing as this discovery was, it was not the end of the wonder, for two minutes later, on somewhat descending, the temperature commenced decreasing so rapidly as to show a fall of 27 degrees in 26 minutes. As to personal experiences, Mr. Glaisher should be left to tell his own story. "At the height of 18,844 feet 18 vibrations of a horizontal magnet occupied 26.8 seconds, and at the same height my pulse beat at the rate of 100 pulsations per minute. At 19,415 feet palpitation of the heart became perceptible, the beating of the chronometer seemed very loud, and my breathing became affected. At 19,435 feet my pulse had accelerated, and it was with increasing difficulty that I could read the instruments; the palpitation of the heart was very perceptible; the hands and lips assumed a dark bluish colour, but not the face. At 20,238 feet 28 vibrations of a horizontal magnet occupied 43 seconds. At 21,792 feet I experienced a feeling analogous to sea-sickness, though there was neither pitching nor rolling in the balloon, and through this illness I was unable to watch the instrument long enough to lower the temperature to get a deposit of dew. The sky at this elevation was of a very deep blue colour, and the clouds were far below us. At 22,357 feet I endeavoured to make the magnet vibrate, but could not; it moved through arcs of about 20 degrees, and then settled suddenly. "Our descent began a little after 11 a.m., Mr. Coxwell experiencing considerable uneasiness at our too close vicinity to the Wash. We came down quickly from a height of 16,300 feet to one of 12,400 feet in one minute; at this elevation we entered into a dense cloud which proved to be no less than 8,000 feet in thickness and whilst passing through this the balloon was invisible from the car. From the rapidity of the descent the balloon assumed the shape of a parachute, and though Mr. Coxwell had reserved a large amount of ballast, which he discharged as quickly as possible, we collected so much weight by the condensation of the immense amount of vapour through which we passed that, notwithstanding all his exertions, we came to the earth with a very considerable shock, which broke nearly all the instruments.... The descent took place at Langham, near Oakham." Just a month later Mr. Glaisher, bent on a yet loftier climb, made his second ascent, again under Mr. Coxwell's guidance, and again from Wolverhampton. Besides attending to his instruments he found leisure to make other chance notes by the way. He was particularly struck by the beauty of masses of cloud, which, by the time 12,000 feet were reached, were far below, "presenting at times mountain scenes of endless variety and grandeur, while fine dome-like clouds dazzled and charmed the eye with alternations and brilliant effects of light and shade." When a height of about 20,000 feet had been reached thunder was heard twice over, coming from below, though no clouds could be seen. A height of 4,000 feet more was attained, and shortly after this Mr. Glaisher speaks of feeling unwell. It was difficult to obtain a deposit of dew on the hygrometer, and the working of the aspirator became troublesome. While in this region a sound like that of loud thunder came from the sky. Observations were practically completed at this point, and a speedy and safe return to earth was effected, the landing being at Solihull, seven miles from Birmingham. It was on the 5th of September following that the same two colleagues carried out an exploit which will always stand alone in the history of aeronautics, namely, that of ascending to an altitude which, based on the best estimate they were able to make, they calculated to be no less than seven miles. Whatever error may have unavoidably come into the actual estimate, which is to some extent conjectural, is in reality a small matter, not the least affecting the fact that the feat in itself will probably remain without a parallel of its kind. In these days, when aeronauts attempt to reach an exceptionally lofty altitude, they invariably provide themselves with a cylinder of oxygen gas to meet the special emergencies of the situation, so that when regions of such attenuated air are reached that the action of heart and lungs becomes seriously affected, it is still within their power to inhale the life-giving gas which affords the greatest available restorative to their energies. Forty years ago, however, cylinders of compressed oxygen gas were not available, and on this account alone we may state without hesitation that the enterprise which follows stands unparalleled at the present hour. The filling station at Wolverhampton was quitted at 1.3 p.m., the temperature of the air being 59 degrees on the ground, and falling to 41 degrees at an altitude of 5,000 feet, directly after which a dense cloud was entered, which brought the temperature down to 36 degrees. At this elevation the report of a gun was heard. Here Mr. Glaisher attempted (probably for the first time in history) to take a cloud-scape photograph, the illumination being brilliant, and the plates with which he was furnished being considered extremely sensitive. The attempt, however, was unsuccessful. The height of two miles was reached in 19 minutes, and here the temperature was at freezing point. In six minutes later three miles was reached, and the thermometer was down to 18 degrees. In another twelve minutes four miles was attained, with the thermometer recording 8 degrees, and by further discharge of sand the fifth aerial milestone was passed at 1.50 p.m., i.e. in 47 minutes from the start, with the thermometer 2 degrees below zero. Mr. Glaisher relates that up to this point he had taken observations with comfort, and experienced no trouble in respiration, whilst Mr. Coxwell, in consequence of the exertions he had to make, was breathing with difficulty. More sand was now thrown out, and as the balloon rose higher Mr. Glaisher states that he found some difficulty in seeing clearly. But from this point his experiences should be gathered from his own words:-- "About 1.52 p.m., or later, I read the dry bulb thermometer as minus five; after this I could not see the column of mercury in the wet bulb thermometer, nor the hands of the watch, nor the fine divisions on any instrument. I asked Mr. Coxwell to help me to read the instruments. In consequence, however, of the rotatory motion of the balloon, which had continued without ceasing since leaving the earth, the valve line had become entangled, and he had to leave the car and mount into the ring to readjust it. I then looked at the barometer, and found its reading to be 9 3/4 inches, still decreasing fast, implying a height exceeding 29,000 feet. Shortly after, I laid my arm upon the table, possessed of its full vigour; but on being desirous of using it I found it powerless--it must have lost its power momentarily. Trying to move the other arm, I found it powerless also. Then I tried to shake myself, and succeeded, but I seemed to have no limbs. In looking at the barometer my head fell over my left shoulder. I struggled and shook my body again, but could not move my arms. Getting my head upright for an instant only, it fell on my right shoulder; then I fell backwards, my back resting against the side of the car and my head on its edge. In this position my eyes were directed to Mr. Coxwell in the ring. When I shook my body I seemed to have full power over the muscles of the back, and considerably so over those of the neck, but none over either my arms or my legs. As in the case of the arms, so all muscular power was lost in an instant from my back and neck. I dimly saw Mr. Coxwell, and endeavoured to speak, but could not. In an instant intense darkness overcame me, so that the optic nerve lost power suddenly; but I was still conscious, with as active a brain as at the present moment whilst writing this. I thought I had been seized with asphyxia, and believed I should experience nothing more, as death would come unless we speedily descended. Other thoughts were entering my mind when I suddenly became unconscious, as on going to sleep. I cannot tell anything of the sense of hearing, as no sound reaches the ear to break the perfect stillness and silence of the regions between six and seven miles above the earth. My last observation was made at 1.54 p.m., above 29,000 feet. I suppose two or three minutes to have elapsed between my eyes becoming insensible to seeing fine divisions and 1.54 p.m., and then two or three minutes more to have passed till I was insensible, which I think, therefore, took place about 1.56 p.m. or 1.57 p.m. "Whilst powerless, I heard the words 'Temperature' and 'Observation,' and I knew Mr. Coxwell was in the car speaking to and endeavouring to rouse me--therefore consciousness and hearing had returned. I then heard him speak more emphatically, but could not see, speak, or move. I heard him again say, 'Do try, now do!' Then the instruments became dimly visible, then Mr. Coxwell, and very shortly I saw clearly. Next, I arose in my seat and looked around, as though waking from sleep, though not refreshed, and said to Mr. Coxwell, 'I have been insensible.' He said, 'You have, and I too, very nearly.' I then drew up my legs, which had been extended, and took a pencil in my hand to begin observations. Mr. Coxwell told me that he had lost the use of his hands, which were black, and I poured brandy over them." Mr. Glaisher considers that he must have been totally insensible for a period of about seven minutes, at the end of which time the water reserved for the wet bulb thermometer, which he had carefully kept from freezing, had become a solid block of ice. Mr. Coxwell's hands had become frostbitten, so that, being in the ring and desirous of coming to his friend's assistance, he was forced to rest his arms on the ring and drop down. Even then, the table being in the way, he was unable to approach, and, feeling insensibility stealing over himself, he became anxious to open the valve. "But in consequence of having lost the use of his hands he could not do this. Ultimately he succeeded by seizing the cord in his teeth and dipping his head two or three times until the balloon took a decided turn downwards." Mr. Glaisher adds that no inconvenience followed his insensibility, and presently dropping in a country where no conveyance of any kind could be obtained, he was able to walk between seven and eight miles. The interesting question of the actual height attained is thus discussed by Mr. Glaisher:--"I have already said that my last observation was made at a height of 29,000 feet. At this time, 1.54 p.m., we were ascending at the rate of 1,000 feet per minute, and when I resumed observations we were descending at the rate of 2,000 feet per minute. These two positions must be connected, taking into account the interval of time between, namely, thirteen minutes; and on these considerations the balloon must have attained the altitude of 36,000 or 37,000 feet. Again, a very delicate minimum thermometer read minus 11.9, and this would give a height of 37,000 feet. Mr. Coxwell, on coming from the ring, noticed that the centre of the aneroid barometer, its blue hand, and a rope attached to the car, were all in the same straight line, and this gave a reading of seven inches, and leads to the same result. Therefore, these independent means all lead to about the same elevation, namely, fully seven miles." So far we have followed Mr. Glaisher's account only, but Mr. Coxwell has added testimony of his own to this remarkable adventure, which renders the narrative more complete. He speaks of the continued rotation of the balloon and the necessity for mounting into the ring to get possession of the valve line. "I had previously," he adds, "taken off a thick pair of gloves so as to be the better able to manipulate the sand-bags, and the moment my unprotected hands rested on the ring, which retained the temperature of the air, I found that they were frost-bitten; but I did manage to bring down with me the valve line, after noticing the hand of the aneroid barometer, and it was not long before I succeeded in opening the shutters in the way described by Mr. Glaisher.... Again, on letting off more gas, I perceived that the lower part of the balloon was rapidly shrinking, and I heard a sighing, as if it were in the network and the ruffled surface of the cloth. I then looked round, although it seemed advisable to let off more gas, to see if I could in any way assist Mr. Glaisher, but the table of instruments blocked the way, and I could not, with disabled hands, pass beneath. My last hope, then, was in seeking the restorative effects of a warmer stratum of atmosphere.... Again I tugged at the valve line, taking stock, meanwhile, of the reserve ballast in store, and this, happily, was ample. "Never shall I forget those painful moments of doubt and suspense as to Mr. Glaisher's fate, when no response came to my questions. I began to fear that he would never take any more readings. I could feel the reviving effects of a warmer temperature, and wondered that no signs of animation were noticeable. The hand of the aneroid that I had looked at was fast moving, while the under part of the balloon had risen high above the car. I had looked towards the earth, and felt the rush of air as it passed upwards, but was still in despair when Mr. Glaisher gasped with a sigh, and the next moment he drew himself up and looked at me rather in confusion, and said he had been insensible, but did not seem to have any clear idea of how long until he caught up his pencil and noted the time and the reading of the instruments." The descent, which was at first very rapid, was effected without difficulty at Cold Weston. CHAPTER XV. FURTHER SCIENTIFIC VOYAGES OF GLAISHER AND COXWELL. Early in the following spring we find the same two aeronauts going aloft again on a scientific excursion which had a termination nearly as sensational as the last. The ascent was from the Crystal Palace, and the intention being to make a very early start the balloon for this purpose had been partially filled overnight; but by the morning the wind blew strongly, and, though the ground current would have carried the voyagers in comparative safety to the southwest, several pilots which were dismissed became, at no great height, carried away due south. On this account the start was delayed till 1 p.m., by which time the sky had nearly filled in, with only occasional gleams of sun between the clouds. It seemed as if the travellers would have to face the chance of crossing the Channel, and while, already in the car, they were actually discussing this point, their restraining rope broke, and they were launched unceremoniously into the skies. This occasioned an unexpected lurch to the car, which threw Mr. Glaisher among his instruments, to the immediate destruction of some of them. Another result of this abrupt departure was a very rapid rise, which took the balloon a height of 3,000 feet in three minutes' space, and another 4,000 feet higher in six minutes more. Seven thousand feet vertically in nine minutes is fast pace; but the voyagers were to know higher speed yet that day when the vertical motion was to be in the reverse and wrong direction. At the height now reached they were in cloud, and while thus enveloped the temperature, as often happens, remained practically stationary at about 32 degrees, while that of the dew point increased several degrees. But, on passing out of the cloud, the two temperatures were very suddenly separated, the latter decreasing rapidly under a deep blue upper sky that was now without a cloud. Shortly after this the temperature dropped suddenly some 8 degrees, and then, during the next 12,000 feet, crept slowly down by small stages. Presently the balloon, reaching more than twenty thousand feet, or, roughly, four miles, and still ascending, the thermometer was taken with small fits of rising and falling alternately till an altitude of 24,000 feet was recorded, at which point other and more serious matters intruded themselves. The earth had been for a considerable time lost to view, and the rate and direction of recent progress had become merely conjectural. What might be taking place in these obscured and lofty regions? It would be as well to discover. So the valve was opened rather freely, with the result that the balloon dropped a mile in three minutes. Then another mile slower, by a shade. Then at 12,000 feet a cloud layer was reached, and shortly after the voyagers broke through into the clear below. At that moment Mr. Glaisher, who was busy with his instruments, heard Mr. Coxwell make an exclamation which caused him to look over the car, and he writes, "The sea seemed to be under us. Mr. Coxwell again exclaimed, 'There's not a moment to spare: we must save the land at all risks. Leave the instruments.' Mr. Coxwell almost hung to the valve line, and told me to do the same, and not to mind its cutting my hand. It was a bold decision opening the valve in this way, and it was boldly carried out." As may be supposed, the bold decision ended with a crash. The whole time of descending the four and a quarter miles was a quarter of an hour, the last two miles taking four minutes only. For all that, there was no penalty beyond a few bruises and the wrecking of the instruments, and when land was reached there was no rebound; the balloon simply lay inert hard by the margin of the sea. This terrific experience in its salient details is strangely similar to that already recorded by Albert Smith. In further experimental labours conducted during the summer of this year, many interesting facts stand out prominently among a voluminous mass of observations. In an ascent in an east wind from the Crystal Palace in early July it was found that the upper limit of that wind was reached at 2,400 feet, at which level an air-stream from the north was encountered; but at 3,000 feet higher the wind again changed to a current from the N.N.W. At the height, then, of little more than half a mile, these upper currents were travelling leisurely; but what was more noteworthy was their humidity, which greatly increased with altitude, and a fact which may often be noted here obtruded itself, namely, when the aeronauts were at the upperlimits of the east wind, flat-bottomed cumulus clouds were floating at their level. These clouds were entirely within the influence of the upper or north wind, so that their under sides were in contact with the east wind, i.e. with a much drier air, which at once dissipated all vapour in contact with it, and thus presented the appearance of flat-bottomed clouds. It is a common experience to find the lower surface of a cloud mowed off flat by an east wind blowing beneath it. At the end of June a voyage from Wolverton was accomplished, which yielded remarkable results of much real value and interest. The previous night had been perfectly calm, and through nearly the whole morning the sun shone in a clear blue sky, without a symptom of wind or coming change. Shortly before noon, however, clouds appeared aloft, and the sky assumed an altered aspect. Then the state of things quickly changed. Wind currents reached the earth blowing strongly, and the half-filled balloon began to lurch to such an extent that the inflation could only with difficulty be proceeded with. Fifty men were unable to hold it in sufficient restraint to prevent rude bumping of the car on the ground, and when, at length, arrangements were complete and release effected, rapid discharge of ballast alone saved collision with neighbouring buildings. It was now that the disturbance overhead came under investigation; and, considering the short period it had been in progress, proved most remarkable, the more so the further it was explored. At 4,000 feet they plunged into the cloud canopy, through which as it was painfully cold, they, sought to penetrate into the clear above, feeling confident of finding themselves, according to their usual experience, in bright blue sky, with the sun brilliantly shining. On the contrary, however, the region they now entered was further obscured with another canopy of cloud far up. It was while they were traversing this clear interval that a sound unwonted in balloon travel assailed their ears. This was the "sighing, or rather moaning, of the wind as preceding a storm." Rustling of the silk within the cordage is often heard aloft, being due to expansion of gas or similar cause; but the aeronauts soon convinced themselves that what they heard was attributable to nothing else than the actual conflict of air currents beneath. Then they reached fog--a dry fog--and, passing through it, entered a further fog, but wetting this time, and within the next 1,000 feet they were once again in fog that was dry; and then, reaching three miles high and seeing struggling sunbeams, they looked around and saw cloud everywhere, below, above, and far clouds on their own level. The whole sky had filled in most completely since the hours but recently passed, when they had been expatiating on the perfect serenity of the empty heavens. Still they climbed upwards, and in the next 2,000 feet had entered further fog, dry at first, but turning wetter as they rose. At four miles high they found themselves on a level with clouds, whose dark masses and fringed edges proved them to be veritable rain clouds; and, while still observing them, the fog surged up again and shut out the view, and by the time they had surmounted it they were no less than 23,000 feet up, or higher than the loftiest of the Andes. Even here, with cloud masses still piling high overhead, the eager observer, bent on further quests, was for pursuing the voyage; but Mr. Coxwell interposed with an emphatic, "Too short of sand!" and the downward journey had to be commenced. Then phenomena similar to those already described were experienced again--fog banks (sometimes wet, sometimes dry), rain showers, and cloud strata of piercing cold. Presently, too, a new wonder for a midsummer afternoon--a snow scene all around, and spicules of ice settling and remaining frozen on the coatsleeve. Finally dropping to earth helplessly through the last 5,000 feet, with all ballast spent, Ely Cathedral was passed at close quarters; yet even that vast pile was hidden in the gloom that now lay over all the land. It was just a month later, and day broke with thoroughly dirty weather, a heavy sky, and falling showers. This was the day of all others that Mr. Glaisher was waiting for, having determined on making special investigations concerning the formation of rain in the clouds themselves. It had long been noticed that, in an ordinary way, if there be two rain gauges placed, one near the surface of the ground, and another at a somewhat higher elevation, then the lower gauge will collect most water. Does, then, rain condense in some appreciable quantity out of the lowest level? Again, during rain, is the air saturated completely, and what regulates the quality of rainfall, for rain sometimes falls in large drops and sometimes in minute particles? These were questions which Mr. Glaisher sought to solve, and there was another. Charles Green had stated as his conviction that whenever rain was falling from an overcast sky there would always be found a higher canopy of cloud over-hanging the lower stratum. On the day, then, which we are now describing, Mr. Glaisher wished to put this his theory to the test; and, if correct, then he desired to measure the space between the cloud layers, to gauge their thickness, and to see if above the second stratum the sun was shining. The main details of the ascent read thus:-- In ten seconds they were in mist, and in ten seconds more were level with the cloud. At 1,200 feet they were out of the rain, though not yet out of the cloud. Emerging from the lower cloud at 2,300 feet, they saw, what Green would have foretold, an upper stratum of dark cloud above. Then they made excursions up and down, trying high and low to verify these conditions, and passing through fogs both wet and dry, at last drifting earthward, through squalls of wind and rain with drops as large as fourpenny pieces, to find that on the ground heavy wet had been ceaselessly falling. A day trip over the eastern suburbs of London in the same year seems greatly to have impressed Mr. Glaisher. The noise of London streets as heard from above has much diminished during the last fifteen years' probably owing to the introduction of wood paving. But, forty years ago, Mr. Glaisher describes the deep sound of London as resembling the roar of the sea, when at a mile high; while at greater elevations it was heard at a murmuring noise. But the view must have been yet more striking than the hearing, for in one direction the white cliffs from Margate to Dover were visible, while Brighton and the sea beyond were sighted, and again all the coast line up to Yarmouth yet the atmosphere that day, one might have thought, should have been in turmoil, by reason of a conflict of aircurrents; for, within two miles of the earth, the wind was from the east; between two and three miles high it was exactly opposite, being from the west; but at three miles it was N.E.; while, higher, it was again directly opposite, or S.W. During his researches so far Mr. Glaisher had found much that was anomalous in the way of the winds, and in other elements of weather. He was destined to find much more. It had been commonly accepted that the temperature of the air decreases at the average rate of 10 degrees for every 300 feet of elevation, and various computations, as, for example, those which relate to the co-efficient of refraction, have been founded on this basis; but Mr. Glaisher soon established that the above generalisation had to be much modified. The following, gathered from his notes is a typical example of such surprises as the aeronaut with due instrumental equipment may not unfrequently meet with. It was the 12th of January, 1864, with an air-current on the ground from the S.E., of temperature 41 degrees,, which very slowly decreased up to 1,600 feet when a warm S.W. current was met with, and at 3,000 feet the temperature was 3 1/2 degrees higher than on the earth. Above the S.W. stream the air became dry, and here the temperature decreased reasonably and consistently with altitude; while fine snow was found falling out of this upper space into the warmer stream below. Mr. Glaisher discusses the peculiarity and formation of this stream in terms which will repay consideration. "The meeting with this S.W. current is of the highest importance, for it goes far to explain why England possesses a winter temperature so much higher than is due to her northern latitude. Our high winter temperature has hitherto been mostly referred to the influence of the Gulf Stream. Without doubting the influence of this natural agent, it is necessary to add the effect of a parallel atmospheric current to the oceanic current coming from the same region--a true aerial Gulf Stream. This great energetic current meets with no obstruction in coming to us, or to Norway, but passes over the level Atlantic without interruption from mountains. It cannot, however, reach France without crossing Spain and the lofty range of the Pyrenees, and the effect of these cold mountains in reducing its temperature is so great that the former country derives but little warmth from it." An ascent from Woolwich, arranged as near the equinox of that year as could be managed, supplied some further remarkable results. The temperature, which was 45 degrees to begin with, at 4.7 p.m., crept down fairly steadily till 4,000 feet altitude was registered, when, in a region of warm fog, it commenced rising abruptly, and at 7,500 feet, in blue sky, stood at the same reading as when the balloon had risen only 1,500 feet. Then, amid many anomalous vicissitudes, the most curious, perhaps, was that recorded late in the afternoon, when, at 10,000 feet, the air was actually warmer than when the ascent began. That the temperature of the upper air commonly commences to rise after nightfall as the warmth radiated through day hours off the earth collects aloft, is a fact well known to the balloonist, and Mr. Glaisher carried out with considerable success a well-arranged programme for investigating the facts of the case. Starting from Windsor on an afternoon of late May, he so arranged matters that his departure from earth took place about an hour and three quarters before sunset, his intention being to rise to a definite height, and with as uniform a speed as possible to time his descent so as to reach earth at the moment of sundown; and then to re-ascend and descend again m a precisely similar manner during an hour and three-quarters after sunset, taking observations all the way. Ascending for the first flight, he left a temperature of 58 degrees on the earth, and found it 55 degrees at 1,200 feet, then 43 degrees at 3,600 feet, and 29 1/2 degrees at the culminating point of 6,200 feet. Then, during the descent, the temperature increased, though not uniformly, till he was nearly brushing the tops of the trees, where it was some 3 degrees colder than at starting. It was now that the balloon, showing a little waywardness, slightly upset a portion of the experiment, for, instead of getting to the neighbourhood of earth just at the moment of sunset, the travellers found themselves at that epoch 600 feet above the ground, and over the ridge of a hill, on passing which the balloon became sucked down with a down draught, necessitating a liberal discharge of sand to prevent contact with the ground. This circumstance, slight in itself, caused the lowest point of the descent to be reached some minutes late, and, still more unfortunate, occasioned the ascent which immediately followed to be a rapid one, too rapid, doubtless, to give the registering instruments a fair chance; but one principal record aimed at was obtained at least with sufficient truth, namely, that at the culminating point, which again was 6,200 feet, the temperature read 35 degrees, or about 6 degrees warmer than when the balloon was at the same altitude a little more than an hour before. This comparatively warm temperature was practically maintained for a considerable portion of the descent. We may summarise the principal of Mr. Glaisher's generalisations thus, using as nearly as possible his own words:-- "The decrease of temperature, with increase of elevation, has a diurnal range, and depends upon the hour of the day, the changes being the greatest at mid-day and the early part of the afternoon, and decreasing to about sunset, when, with a clear sky, there is little or no change of temperature for several hundred feet from the earth; whilst, with a cloudy sky, the change decreases from the mid-day hours at a less rapid rate to about sunset, when the decrease is nearly uniform and at the rate of 1 degree in 2,000 feet. "Air currents differing in direction are almost always to be met with. The thicknesses of these were found to vary greatly. The direction of the wind on the earth was sometimes that of the whole mass of air up to 20,000 feet nearly, whilst at other times the direction changed within 500 feet of the earth Sometimes directly opposite currents were met with." With regard to the velocity of upper currents, as shown by the travel of balloons, when the distances between the places of ascent and descent are measured, it was always found that these distances were very much greater than the horizontal movement of the air, as measured by anemometers near the ground. CHAPTER XVI. SOME FAMOUS FRENCH AERONAUTS. By this period a revival of aeronautics in the land of its birth had fairly set in. Since the last ascents of Gay Lussac, in 1804, already recorded, there had been a lull in ballooning enterprise in France, and no serious scientific expeditions are recorded until the year 1850, when MM. Baral and Bixio undertook some investigations respecting the upper air, which were to deal with its laws of temperature and humidity, with the proportion of carbonic acid present in it, with solar heat at different altitudes, with radiation and the polarisation of light, and certain other interesting enquiries. The first ascent, made in June from the Paris Observatory, though a lofty one, was attended with so much danger and confusion as to be barren of results. The departure, owing to stormy weather, was hurried and illordered, so that the velocity in rising was excessive, the net constricted the rapidly-swelling globe, and the volumes of out-rushing gas half-suffocated the voyagers. Then a large rent occurred, which caused an alarmingly rapid fall, and the two philosophers were reduced to the necessity of flinging away all they possessed, their instruments only excepted. The landing, in a vineyard, was happily not attended with disaster, and within a month the same two colleagues attempted a second aerial excursion, again in wet weather. It would seem as if on this occasion, as on the former one, there was some lack of due management, for the car, suspended at a long distance from the balloon proper, acquired violent oscillations on leaving the ground, and dashing first against a tree, and then against a mast, broke some of the instruments. A little later there occurred a repetition on a minor scale of the aeronauts' previous mishap, for a rent appeared in the silk, though, luckily, so low down in the balloon as to be of small consequence, and eventually an altitude of some 19,000 feet was attained. At one time needles of ice were encountered settling abundantly with a crackling sound upon their notebooks. But the most remarkable observation made during this voyage related to an extraordinary fall of temperature which, as recorded, is without parallel. It took place in a cloud mass, 15,000 feet thick, and amounted to a drop of from 15 degrees to -39 degrees. In 1867 M. C. Flammarion made a few balloon ascents, ostensibly for scientific research. His account of these, translated by Dr. T. L. Phipson, is edited by Mr. Glaisher, and many of the experiences he relates will be found to contrast with those of others. His physical symptoms alone were remarkable, for on one occasion, at an altitude of apparently little over 10,000 feet, he became unwell being affected with a sensation of drowsiness, palpitation, shortness of breath, and singing in the ears, which, after landing gave place to a "fit of incessant gaping" while he states that in later voyages, at but slightly greater altitudes, his throat and lungs became affected, and he was troubled with presence of blood upon the lips. This draws forth a footnote from Mr. Glaisher, which should be commended to all would-be sky voyagers. It runs thus:--"I have never experienced any of these effects till I had long passed the heights reached by M. Flammarion, and at no elevation was there the presence of blood." However, M. Flammarion adduces, at least, one reassuring fact, which will be read with interest. Once, having, against the entreaties of his friends, ascended with an attack of influenza upon him, he came down to earth again an hour or two afterwards with this troublesome complaint completely cured. It would seem as if the soil of France supplied the aeronaut with certain phenomena not known in England, one of these apparently being the occasional presence of butterflies hovering round the car when at considerable heights. M. Flammarion mentions more than one occasion when he thus saw them, and found them to be without sense of alarm at the balloon or its passengers. Again, the French observer seems seldom to have detected those opposite airstreams which English balloonists may frequently observe, and have such cause to be wary of. His words, as translated, are:--"It appears to me that two or more currents, flowing in different directions, are very rarely met with as we rise in the air, and when two layers of cloud appear to travel in opposite directions the effect is generally caused by the motion of one layer being more rapid than the other, when the latter appears to be moving in a contrary direction." In continuation of these experiences, he speaks of an occasion when, speeding through the air at the rate of an ordinary express train, he was drawn towards a tempest by a species of attraction. The French aeronaut's estimate of what constitutes a terrific rate of fall differs somewhat from that of others whose testimony we have been recording. In one descent, falling (without reaching earth, however) a distance of 2,130 feet in two minutes, he describes the earth rising up with frightful rapidity, though, as will be observed, this is not nearly half the speed at which either Mr. Glaisher or Albert Smith and his companions were precipitated on to bare ground. Very many cases which we have cited go to show that the knowledge of the great elasticity of a well-made wicker car may rob a fall otherwise alarming of its terrors, while the practical certainty that a balloon descending headlong will form itself into a natural parachute, if properly managed, reduces enormously the risk attending any mere impact with earth. It will be allowed by all experienced aeronauts that far worse chances lie in some awkward alighting ground, or in the dragging against dangerous obstacles after the balloon has fallen. Many of M. Flammarion's experiments are remarkable for their simplicity. Indeed, in some cases he would seem to have applied himself to making trials the result of which could not have been seriously questioned. The following, quoting from Dr. Phipson's translation, will serve as an example:-- "Another mechanical experiment was made in the evening, and renewed next day. I wished to verify Galileo's principle of the independence of simultaneous motions. According to this principle, a body which is allowed to fall from another body in motion participates in the motion of the latter; thus, if we drop a marble from the masthead of a ship, it preserves during its fall the rate of motion of the vessel, and falls at the foot of the mast as if the ship were still. Now, if a body falls from a balloon, does it also follow the motion of the latter, or does it fall directly to the earth in a line which is perpendicular to the point at which we let it fall? In the first case its fall would be described by an oblique line. The latter was found to be the fact, as we proved by letting a bottle fall. During its descent it partakes of the balloon's motion, and until it reaches the earth is always seen perpendicularly below the car." An interesting phenomenon, relating to the formation of fog was witnessed by M. Flammarion in one of his voyages. He was flying low with a fast wind, and while traversing a forest he noticed here and there patches of light clouds, which, remaining motionless in defiance of the strong wind, continued to hang above the summits of the trees. The explanation of this can hardly be doubtful, being analogous to the formation of a night-cap on a mountain peak where warm moist air-currents become chilled against the cold rock surface, forming, momentarily, a patch of cloud which, though constantly being blown away, is as constantly re-formed, and thus is made to appear as if stationary. The above instructive phenomenon could hardly have been noticed save by an aeronaut, and the same may be said of the following. Passing in a clear sky over the spot where the Marne flows into the Seine, M. Flammarion notes that the water of the Marne, which, as he says, is as yellow now as it was in the time of Julius Caesar, does not mix with the green water of the Seine, which flows to the left of the current, nor with the blue water of the canal, which flows to the right. Thus, a yellow river was seen flowing between two distinct brooks, green and blue respectively. Here was optical evidence of the way in which streams of water which actually unite may continue to maintain independent courses. We have seen that the same is true of streams of air, and, where these traverse one another in a copious and complex manner, we find, as will be shown, conditions produced that cause a great deadening of sound; thus, great differences in the travel of sound in the silent upper air can be noticed on different days, and, indeed, in different periods of the same aerial voyage. M. Flammarion bears undeniable testimony to the manner in which the equable condition of the atmosphere attending fog enhances, to the aeronaut, the hearing of sounds from below. But when he gives definite heights as the range limits of definite sounds it must be understood that these ranges will be found to vary greatly according to circumstances. Thus, where it is stated that a man's voice may make itself heard at 3,255 feet, it might be added that sometimes it cannot be heard at a considerably less altitude; and, again, the statement that the whistle of a locomotive rises to near 10,000 feet, and the noise of a railway train to 8,200 feet, should be qualified an additional note to the effect that both may be occasionally heard at distances vastly greater. But perhaps the most curious observation of M. Flammarion respecting sounds aloft relates to that of echo. To his fancy, this had a vague depth, appearing also to rise from the horizon with a curious tone, as if it came from another world. To the writer, on the contrary, and to many fellow observers who have specially experimented with this test of sound, the echo has always appeared to come very much from the right place--the spot nearly immediately below--and if this suggested its coming from another world then the same would have to be said of all echoes generally. About the same period when M. Flammarion was conducting his early ascents, MM. de Fonvielle and Tissandier embarked on experimental voyages, which deserve some particular notice. Interest in the new revival of the art of aeronautics was manifestly be coming reestablished in France, and though we find enthusiasts more than once bitterly complaining of the lack of financial assistance, still ballooning exhibitions, wherever accomplished, never failed to arouse popular appreciation. But enthusiasm was by no means the universal attitude with which the world regarded aerial enterprise. A remarkable and instructive instance is given to the contrary by M. W. de Fonvielle himself. He records an original ballooning exploit, organised at Algiers, which one might have supposed would have caused a great sensation, and to which he himself had called public attention in the local journals. The brothers Braguet were to make an ascent from the Mustapha Plain in a small fire balloon heated with burning straw, and this risky performance was successfully carried out by the enterprising aeronauts. But, to the onlooker, the most striking feature of the proceeding was the fact that while the Europeans present regarded the spectacle with curiosity and pleasure, the native Mussulmans did not appear to take the slightest interest in it; "And this," remarked de Fonvielle, "was not the first time that ignorant and fanatic people have been noted as manifesting complete indifference to balloon ascents. After the taking of Cairo, when General Buonaparte wished to produce an effect upon the inhabitants, he not only made them a speech, but supplemented it with the ascent of a fire balloon. The attempt was a complete failure, for the French alone looked up to the clouds to see what became of the balloon." In the summer of 1867 an attempt was made to revive the long extinct Aeronautic Company of France, established by De Guyton. The undertaking was worked with considerable energy. Some forty or fifty active recruits were pressed into the service, a suitable captive balloon was obtained, thousands of spectators came to watch the evolutions; and many were found to pay the handsome fee of 100 francs for a short excursion in the air. For all this, the effort was entirely abortive, and the ballooning corps, as such, dropped out of existence. A little while after this de Fonvielle, on a visit to England, had a most pathetic interview with the veteran Charles Green, who was living in comfortable retirement at Upper Holloway. The grand old man pointed to a well-filled portfolio in the corner of his room, in which, he said, were accounts of all his travels, that would require a lifetime to peruse and put in order. Green then took his visitor to the end of the narrow court, and, opening the door of an outhouse, showed him the old Nassau balloon. "Here is my car," he said, touching it with a kind of solemn respect, "which, like its old pilot, now reposes quietly after a long and active career. Here is the guide rope which I imagined in former years, and which has been found very useful to aeronauts.... Now my life has past and my time has gone by.... Though my hair is white and my body too weak to help you, I can still give you my advice, and you have my hearty wishes for your future." It was but shortly after this, on March 26, 1870, that Charles Green passed away in the 85th year of his age. De Fonvielle's colleague, M. Gaston Tissandier, was on one occasion accidentally brought to visit the resting place of the earliest among aeronauts, whose tragic death occurred while Charles Green himself was yet a boy. In a stormy and hazardous descent Tissandier, under the guidance of M. Duruof, landed with difficulty on the sea coast of France, when one of the first to render help was a lightkeeper of the Griz-nez lighthouse, who gave the information that on the other side of the hills, a few hundred yards from the spot where they had landed, was the tomb of Pilatre de Rozier, whose tragical death has been recorded in an early chapter. A visit to the actual locality the next day revealed the fact that a humble stone still marked the spot. Certain scientific facts and memoranda collected by the talented French aeronaut whom we are following are too interesting to be omitted. In the same journey to which we have just referred the voyagers, when nearly over Calais, were witnesses from their commanding standpoint of a very striking phenomenon of mirage. Looking in the direction of England, the far coast line was hidden by an immense veil of leaden-coloured cloud, and, following this cloud wall upward to detect where it terminated, the travellers saw above it a greenish layer like that of the surface of the sea, on which was detected a little black point suggesting a walnut shell. Fixing their eyes on this black spot, they presently discerned it to be a ship sailing upside down upon an aerial ocean. Soon after, a steamer blowing smoke, and then other vessels, added themselves to the illusory spectacle. Another wonder detected, equally striking though less uncommon, was of an acoustical nature, the locality this time being over Paris. The height of the balloon at this moment was not great, and, moreover, was diminishing as it settled down. Suddenly there broke in upon the voyagers a sound as of a confused kind of murmur. It was not unlike the distant breaking of waves against a sandy coast, and scarcely less monotonous. It was the noise of Paris that reached them, as soon as they sank to within 2,600 feet of the ground, but it disappeared at once when they threw out just sufficient ballast to rise above that altitude. It might appear to many that so strange and sudden a shutting out of a vast sound occurring abruptly in the free upper air must have been more imaginary than real, yet the phenomenon is almost precisely similar to one coming within the experience the writer, and vouched for by his son and daughter, as also by Mr. Percival Spencer, all of whom were joint observers at the time, the main point of difference in the two cases being the fact that the "region of silence" was recorded by the French observers as occurring at a somewhat lower level. In both cases there is little doubt that the phenomenon can be referred to a stratum of disturbed or non-homogeneous air, which may have been very far spread, and which is capable of acting as a most opaque sound barrier. Attention has often been called in these pages to the fact that the action of the sun on an inflated balloon, even when the solar rays may be partially obscured and only operative for a few passing moments, is to give sudden and great buoyancy to the balloon. An admirable opportunity for fairly estimating the dynamic effect of the sun's rays on a silk globe, whose fabric was half translucent, was offered to the French aeronauts when their balloon was spread on the grass under repair, and for this purpose inflated with the circumambient air by means of a simple rotatory fan. The sun coming out, the interior of the globe quickly became suffocating, and it was found that, while the external temperature recorded 77 degrees, that of the interior was in excess of 91 degrees. CHAPTER XVII. ADVENTURE AND ENTERPRISE. A balloon which has become famous in history was frequently used in the researches of the French aeronauts mentioned in our last chapter. This was known as "The Giant," the creation of M. Nadar, a progressive and practical aeronaut, who had always entertained ambitious ideas about aerial travel. M. Nadar had been editor of L'Aeronaut, a French journal devoted to the advancement of aerostation generally. He had also strongly expressed his own views respecting the possibility of constructing air ships that should be subject to control and guidance when winds were blowing. His great contention was that the dirigible air ship would, like a bird, have to be made heavier than the medium in which it was to fly. As he put it, a balloon could never properly become a vessel. It would only be a buoy. In spite of any number of accessories, paddles, wings, fans, sails, it could not possibly prevent the wind from bodily carrying away the whole concern. After this strong expression of opinion, it may appear somewhat strange that such a bold theoriser should at once have set himself to construct the largest gas balloon on record. Such, however, was the case and the reason urged was not otherwise than plausible. For, seeing that a vast sum of money would be needed to put his theories into practice, M. Nadar conceived the idea of first constructing a balloon so unique and unrivalled that it should compel public attention in a way that no other balloon had done before, and so by popular exhibitions bring to his hand such sums as he required. A proper idea of the scale of this huge machine can be easily gathered. The largest balloons at present exhibited in this country are seldom much in excess of 50,000 cubic feet capacity. Compared with these the "Great Nassau Balloon," built by Charles Green, which has been already sufficiently described, was a true leviathan; while Coxwell's "Mammoth" was larger yet, possessing a content, when fully inflated, of no less than 93,000 cubic feet, and measuring over 55 feet in diameter. This, however, as will be seen, was but a mere pigmy when compared with "The Giant," which, measuring some 74 feet in diameter, possessed the prodigious capacity of 215,000 cubic feet. But the huge craft possessed another novelty besides that of exceptional size. It was provided with a subsidiary balloon, called the "Compensator," and properly the idea of M. L. Godard, the function of which was to receive any expulsion of gas in ascending, and thus to prevent loss during any voyage. The specification of this really remarkable structure may be taken from M. Nadar's own description. The globe in itself was for greater strength virtually double, consisting of two identical balloons, one within the other, each made of white silk of the finest quality, and costing about 5s. 4d. per yard. No less than 22,000 yards of this silk were required, and the sewing up of the gores was entirely done by hand. The small compensating balloon was constructed to have a capacity of about 3,500 cubic feet, and the whole machine, when fully inflated, was calculated to lift 4 1/2 tons. With this enormous margin of buoyancy, M. Nadar determined on making the car of proportionate and unparalleled dimensions, and of most elaborate design. It contained two floors, of which the upper one was open, the height of all being nearly 7 feet, with a width of about 13 feet. Then what was thought to be due provision was made for possible emergencies. It might descend far from help or habitations, therefore means were provided for attaching wheels and axles. Again, the chance of rough impact had to be considered, and so canes, to act as springs, were fitted around and below. Once again, there was the contingency of immersion to be reckoned with; therefore there were provided buoys and water-tight compartments. Further than this, unusual luxuries were added, for there were cabins, one for the captain at one end, and another with three berths for passengers at the other. Nor was this all, for there was, in addition, a larder, a lavatory, a photographic room, and a printing office. It remains now only to tell the tale of how this leviathan of the air acquitted itself. The first ascent was made on the 4th of October, 1853, from the Champ de Mars, and no fewer than fifteen living souls were launched together into the sky. Of these Nadar was captain, with the brothers Godard lieutenants. There was the Prince de Sayn-Wittgenstein; there was the Count de St. Martin; above all, there was a lady, the Princess de la Tour d'Auvergne. The balloon came to earth at 9 o'clock at night near Meaux, and, considering all the provision which had been made to guard against rough landing, it can hardly be said that the descent was a happy one. It appears that the car dragged on its side for nearly a mile, and the passengers, far from finding security in the seclusion of the inner chambers, were glad to clamber out above and cling, as best they might, to the ropes. Many of the party were bruised more or less severely, though no one was seriously injured, and it was reported that such fragile articles as crockery, cakes, confectionery, and wine bottles to the number of no less than thirty-seven, were afterwards discovered to be intact, and received due attention. It is further stated that the descent was decided on contrary to the wishes of the captain, but in deference to the judgment of the experienced MM. Godard, it being apparently their conviction that the balloon was heading out to sea, whereas, in reality, they were going due east, "with no sea at all before them nearer than the Caspian." This was certainly an unpropitious trial trip for the vessel that had so ambitiously sought dominion over the air, and the next trial, which was embarked upon a fortnight later, Sunday, October 18th, was hardly less unfortunate. Again the ascent was from the Champ de Mars, and the send-off lacked nothing in the way of splendour and circumstance. The Emperor was present, for two hours an interested observer of the proceedings; the King of Greece also attended, and even entered the car, while another famous spectator was the popular Meyerbeer. "The Giant" first gave a preliminary demonstration of his power by taking up, for a cable's length, a living freight of some thirty individuals, and then, at 5.10 p.m., started on its second free voyage, with nine souls on board, among them again being a lady, in the person of Madame Nadar. For nearly twenty-four hours no tidings of the voyage were forthcoming, when a telegram was received stating that the balloon had passed over Compiegne, more than seventy miles from Paris, at 8.30 on the previous evening, and that Nadar had dropped the simple message, "All goes well!" A later telegram the same evening stated that the balloon had at midnight on Sunday passed the Belgian frontier over Erquelines, where the Custom House officials had challenged the travellers without receiving an answer. But eight-and-forty hours since the start went by without further news, and excitement in Paris grew intense. When the news came at last it was from Bremen, to say that Nadar's balloon had descended at Eystrup, Hanover, with five of the passengers injured, three seriously. These three were M. Nadar, his wife, and M. St. Felix. M. Nadar, in communicating this intelligence, added, "We owe our lives to the courage of Jules Godard." The following signed testimony of M. Louis Godard is forthcoming, and as it refers to an occasion which is among the most thrilling in aerial adventure, it may well be given without abridgment. It is here transcribed almost literatim from Mr. H. Turner's valuable work, "Astra Castra." "The Giant," after passing Lisle, proceeded in the direction of Belgium, where a fresh current, coming from the Channel, drove it over the marshes of Holland. It was there that M. Louis Godard proposed to descend to await the break of day, in order to recognise the situation and again to depart. It was one in the morning, the night was dark, but the weather calm. Unfortunately, this advice, supported by long experience, was not listened to. "The Giant" went on its way, and then Louis Godard no longer considered himself responsible for the consequences of the voyage. The balloon coasted the Zuyder Zee, and then entered Hanover. The sun began to appear, drying the netting and sides of the balloon, wet from its passage through the clouds, and produced a dilatation which elevated the aeronauts to 15,000 feet. At eight o'clock the wind, blowing suddenly from the west, drove the balloon in a right line towards the North Sea. It was necessary, at all hazards, to effect a descent. This was a perilous affair, as the wind was blowing with extreme violence. The brothers Godard assisted, by M. Gabriel, opened the valve and got out the anchors; but, unfortunately, the horizontal progress of the balloon augmented from second to second. The first obstacle which the anchors encountered was a tree; it was instantly uprooted, and dragged along to a second obstacle, a house, whose roof was carried off. At this moment the two cables of the anchors were broken without the voyagers being aware of it. Foreseeing the successive shocks that were about to ensue--the moment was critical--the least forgetfulness might cause death. To add to the difficulty, the balloon's inclined position did not permit of operating the valve, except on the hoop. At the request of his brother, Jules Godard attempted the difficult work of climbing to this hoop, and, in spite of his known agility, he was obliged several times to renew the effort. Alone, and not being able to detach the cord, M. Louis Godard begged M. Yon to join his brother on the hoop. The two made themselves masters of the rope, which they passed to Louis Godard. The latter secured it firmly, in spite of the shocks he received. A violent impact shook the car and M. de St. Felix became entangled under the car as it was ploughing the ground. It was impossible to render him any assistance; notwithstanding, Jules Godard, stimulated by his brother, leapt out to attempt mooring the balloon to the trees by means of the ropes. M. Montgolfier, entangled in the same manner, was re-seated in time and saved by Louis Godard. At this moment others leapt out and escaped with a few contusions. The car, dragged along by the balloon, broke trees more than half a yard in diameter and overthrew everything that opposed it. Louis Godard made M. Yon leap out of the car to assist Madame Nadar; but a terrible shock threw out MM. Nadar, Louis Godard, and Montgolfier, the two first against the ground, the third into the water. Madame Nadar, in spite of the efforts of the voyagers, remained the last, and found herself squeezed between the ground and the car, which had fallen upon her. More than twenty minutes elapsed before it was possible to disentangle her, in spite of the most vigorous efforts on the part of everyone. It was at this moment the balloon burst and, like a furious monster, destroyed everything around it. Immediately afterwards they ran to the assistance of M. de St. Felix, who had been left behind, and whose face was one ghastly wound, and covered with blood and mire. He had an arm broken, his chest grazed and bruised. After this accident, though a creditable future lay in store for "The Giant," its monstrous and unwieldy car was condemned, and presently removed to the Crystal Palace, where it was daily visited by large crowds. It is impossible to dismiss this brief sketch of French balloonists of this period without paying some due tribute to M. Depuis Delcourt, equally well known in the literary and scientific world, and regarded in his own country as a father among aeronauts. Born in 1802, his recollection went back to the time of Montgolfier and Charles, to the feats of Garnerin, and the death of Madame Blanchard. He established the Aerostatic and Meteorological Society of France, and was the author of many works, as well as of a journal dealing with aerial navigation. He closed a life devoted to the pursuit and advancement of aerostation in April, 1864. Before very long, events began shaping themselves in the political world which were destined to bring the balloon in France into yet greater prominence. But we should mention that already its capabilities in time of war to meet the requirements of military operations had been scientifically and systematically tested, and of these trials it will be necessary to speak without further delay. Reference has already been made in these pages to a valuable article contributed in 1862 by Lieutenant G. Grover, R.E., to the Royal Engineers' papers. From this report it would appear that the balloon, as a means of reconnoitring, was employed with somewhat uncertain success at the battle of Solferino, the brothers Godard being engaged as aeronauts. The balloon used was a Montgolfier, or fire balloon, and, in spite of its ready inflation, MM. Godard considered it, from the difficulty of maintaining within it the necessary degree of buoyancy, far inferior to the gas inflated balloon. On the other hand, the Austrian Engineer Committee were of a contrary opinion. It would seem that no very definite conclusions had been arrived at with respect to the use and value of the military balloon up to the time of the commencement of the American War in 1862. It was now that the practice of ballooning became a recognised department of military manoeuvres, and a valuable report appears in the above-mentioned papers from the pen of Captain F. Beaumont, R.E. According to this officer, the Americans made trial of two different balloons, both hydrogen inflated, one having a capacity of about 13,000 cubic feet, and the other about twice as large. It was this latter that the Americans used almost exclusively, it being found to afford more steadiness and safety, and to be the means, sometimes desirable, of taking up more than two persons. The difficulty of sufficient gas supply seems to have been well met. Two generators sufficed, these being "nothing more than large tanks of wood, acid-proof inside, and of sufficient strength to resist the expansive action of the gas; they were provided with suitable stopcocks for regulating the admission of the gas, and with manhole covers for introducing the necessary materials." The gas, as evolved, being made to pass successively through two vessels containing lime water, was delivered cool and purified into the balloon, and as the sulphuric acid needed for the process was found sufficiently cheap, and scrap iron also required was readily come by, it would seem that practical difficulties in the field were reduced to a minimum. According to Captain Beaumont, the difficulties which might have been expected from windy weather were not considerable, and twenty-five or thirty men sufficed to convey the balloon easily, when inflated, over all obstacles. The transport of the bulk of the rest of the apparatus does not read, on paper, a very serious matter. The two generators required four horses each, and the acid and balloon carts as many more. Arrived on the scene of action, the drill itself was a simple matter. A squad of thirty men under an officer sufficed to get the balloon into position, and to arrange the ballast so that, with all in, there was a lifting power of some thirty pounds. Then, at the word of command, the men together drop the car, and seize the three guy ropes, of which one is made to pass through a snatch block firmly secured. The guy ropes are then payed out according to the directions of the aeronaut, as conveyed through the officer. The balloon accompanied the army's advance where its services could be turned to the greatest advantage. It was employed in making continual ascents, and furnishing daily reports to General M'Clellan, and it was supposed that by constant observation the aeronaut could, at a glance, assure himself that no change had taken place in the occupation of the country. Captain Beaumont, speaking, be it remembered, of the military operations and manoeuvres then in vogue, declared that earthworks could be seen even at the distance of eight miles, though their character could not be distinctly stated. Wooded country was unfitted for balloon reconnaissance, and only in a plain could any considerable body of troops be made known. Then follows such a description as one would be expecting to find:-- "During the battle of Hanover Court House, which was the first engagement of importance before Richmond, I happened to be close to the balloon when the heavy firing began. The wind was rather high; but I was anxious to see, if possible, what was going on, and I went up with the father of the aeronaut. The balloon was, however, short of gas, and as the wind was high we were obliged to come down. I then went up by myself, the diminished weight giving increased steadiness; but it was not considered safe to go more than 500 feet, on account of the unsettled state of the weather. The balloon was very unsteady, so much so that it was difficult to fix my sight on any particular object. At that distance I could see nothing of the fight." Following this is another significant sentence:-- "In the case of a siege, I am inclined to think that a balloon reconnaissance would be of less value than in almost any other case where a reconnaissance can be required; but, even here, if useless, it is, at any rate, also harmless. I once saw the fire of artillery directed from the balloon; this became necessary, as it was only in this way that the picket which it was desired to dislodge could be seen. However, I cannot say that I thought the fire of artillery was of much effect against the unseen object; not that this was the fault of the balloon, for had it not told the artillerists which way the shots were falling their fire would have been more useless still." It will be observed that at this time photography had not been adopted as an adjunct to military ballooning. Full details have been given in this chapter of the monster balloon constructed by M. Nadar; but in 1864 Eugene Godard built one larger yet of the Montgolfier type. Its capacity was nearly half a million cubic feet, while the stove which inflated it stood 18 feet high, and weighed nearly 1,000 pounds. Two free ascents were made without mishap from Cremorne Gardens. Five years later Ashburnham Park was the scene of captive ascents made with another mammoth balloon, containing no less than 350,000 cubic feet of pure hydrogen, and capable of lifting 11 tons. It was built at a cost of 28,000 francs by M. Giffard, the well-known engineer and inventor of the injector for feeding steam engines. These aerial leviathans do not appear to have been, in any true sense successful. CHAPTER XVIII. THE BALLOON IN THE SIEGE OF PARIS. Within a few months of the completion of the period covered by the records of the last chapter, France was destined to receive a more urgent stimulus than ever before to develop the resources of ballooning, and, in hot haste, to turn to the most serious and practical account all the best resources of aerial locomotion. The stern necessity of war was upon her, and during four months the sole mode of exit from Paris--nay, the only possible means of conveying a simple message beyond the boundary of her fortifications--was by balloon. Hitherto, from the very inception of the art from the earliest Montgolfier with its blazing furnace, the balloon had gone up from the gay capital under every variety of circumstance--for pleasure, for exhibition, for scientific research. It was now put in requisition to mitigate the emergency occasioned by the long and close investment of the city by the Prussian forces. Recognising, at an early stage, the possibilities of the balloon, an enquiry was at once made by the military authorities as to the existing resources of the city, when it was quickly discovered that, with certain exceptions to be presently mentioned, such balloons as were in existence within the walls were either unserviceable or inadequate for the work that was demanded of them. Thereupon, with admirable promptness and enterprise, it was forthwith determined to organise the building and equipment of a regular fleet of balloons of sufficient size and strength. It chanced that there were in Paris at the time two professional aeronauts of proved experience and skill, both of whom had become well known in London only the season before in connection with M. Giffard's huge captive balloon at Ashburnham Park. These were MM. Godard and Yon, and to them was entrusted the establishment of two separate factories in spacious buildings, which were at once available and admirably adapted for the purpose. These were at the Orleans and the Northern Railway stations respectively, where spacious roofs and abundant elbow room, the chief requisites, were to be found. The first-mentioned station was presided over Godard, the latter by M. Yon, assisted by M. Dartois. It was not doubted that the resources of the city would be able to supply the large demand that would be made for suitable material; but silk as a fabric was at once barred on the score of expense alone. A single journey was all that needed to be calculated on for each craft, and thus calico would serve the purpose, and would admit of speedy making up. Slight differences in manufacture were adopted at the two factories. At the Northern station plain white calico was used, sewn with a sewing machine, whereas at the Orleans station the material was coloured and entrusted only to hand stitching. The allimportant detail of varnish was supplied by a mixture of linseed oil and the active principle of ordinary driers, and this, laid on with a rubber, rendered the material gas-tight and quickly dry enough for use. Hundreds of hands, men and women, were employed at the two factories, at which some sixty balloons were produced before the end of the siege. Much of the more important work was entrusted to sailors, who showed special aptness, not only in fitting out and rigging the balloons, but also in their management when entrusted to the winds. It must have been an impressive sight for friend or foe to witness the departure of each aerial vessel on its venturesome mission. The bold plunge into space above the roofs of the imprisoned city; the rapid climb into the sky and, later, the pearl drop high in air floating away to its uncertain and hazardous haven, running the gauntlet of the enemy's fire by day or braving what at first appeared to be equal danger, attending the darkness of night. It will be seen, however, that, of the two evils, that of the darkness was considered the less, even though, with strange and unreasonable excess of caution, the aeronauts would not suffer the use of the perfectly safe and almost indispensable Davy lamp. Before any free ascents were ventured on, two old balloons were put to some practical trial as stationary observatories. One of these was moored at Montmartre, the other at Mont-souris. From these centres daily, when the weather permitted, captive ascents were made--four by day and two by night--to watch and locate the movements of the enemy. The system, as far as it went, was well planned. It was safe, and, to favour expedition, messages were written in the car of the balloon and slid down the cable to the attendants below. The net result, however, from a strategic point of view, does not appear to have been of great value. Ere yet the balloons were ready, certain bold and eventful escapes were ventured on. M. Duruof, already introduced in these pages, trusting himself to the old craft, "Le Neptune," in unskyworthy condition, made a fast plunge into space, and, catching the upper winds, was borne away for as long a period as could be maintained at the cost of a prodigal expenditure of ballast. The balloon is said to have described a visible parabola, like the trajectory of a projectile, and fell at Evreux in safety and beyond the range of the enemy's fire, though not far from their lines. This was on the 23rd of September. Two days afterwards the first practical trial was made with homing pigeons, with the idea of using them in connection with balloons for the establishment of an officially sanctioned post. MM. Maugin and Grandchamp conducted this voyage in the "Ville de Florence," and descended near Vernouillet, not far beyond Le Foret de St. Germain, and less than twenty miles from Paris. The serviceability of the pigeon, however, was clearly established, and a note contributed by Mr. Glaisher, relating to the breeding and choice of these birds, may be considered of interest. Mr. R. W. Aldridge, of Charlton, as quoted by Mr. Glaisher, stated that his experience went to show that these birds can be produced with different powers of orientation to meet the requirements of particular cases. "The bird required to make journeys under fifty miles would materially differ in its pedigree from one capable of flying 100 or 600 miles. Attention, in particular, must be given to the colour of the eye; if wanted for broad daylight the bird known as the 'Pearl Eye,' from its colour, should be selected; but if for foggy weather or for twilight flying the black- or blue-eyed bird should receive the preference." Only a small minority, amounting to about sixty out of 360 birds taken up, returned to Paris, but these are calculated to have conveyed among them some 100,000 messages. To reduce these pigeon messages to the smallest possible compass a method of reduction by photography was employed with much success. A long letter might, in this way, be faithfully recorded on a surface of thinnest photographic paper, not exceeding the dimensions of a postage stamp, and, when received, no more was necessary than to subject it to magnification, and then to transcribe it and send a fair copy to the addressee. The third voyage from Paris, on September 29th was undertaken by Louis Godard in two small balloons, united together, carrying both despatches and pigeons, and a safe landing was effected at Mantes This successful feat was rival led the next day by M. Tissandier, who ascended alone in a balloon of only some 26,000 cubic feet capacity and reached earth at Dreux, in Normandy. These voyages exhausted the store of ready-made balloons, but by a week later the first of those being specially manufactured was ready, and conveyed in safety from the city no less a personage than M. Gambetta. The courageous resolve of the great man caused much sensation in Paris, the more so because, owing to contrary winds, the departure had to be postponed from day to day. And when, at length, on October 7th, Gambetta and his secretary, with the aeronaut Trichet, actually got away, in company with another balloon, they were vigorously fired at with shot and shell before they had cleared St. Denis. Farther out over the German posts they were again under fire, and escaped by discharging ballast, not, however, before Gambetta had been grazed by a bullet. Yet once more they were assailed by German volleys before, about 3 p.m., they found a haven near Montdidier. The usual dimensions of the new balloons gave a capacity of 70,000 cubic feet, and each of these, when inflated with coal gas, was calculated to convey a freight of passengers, ballast, and despatches amounting to some 2,000 pounds. Their despatch became frequent, sometimes two in the same twenty-four hours. In less than a single week in October as many as four balloons had fallen in Belgium, and as many more elsewhere. Up till now some sixteen ventures had ended well, but presently there came trouble. On October 22nd MM. Iglesia and Jouvencel fell at Meaux, occupied by the Prussians; their despatches, however, were saved in a dung cart. The twenty-third voyage ended more unhappily. On this occasion a sailor acted as aeronaut, accompanied by an engineer, Etienne Antonin, and carrying nearly 1,000 pounds of letters. It chanced that they descended near Orleans on the very day when that town was re-occupied by the enemy, and both voyagers were made prisoners. The engineer, however, subsequently escaped. Three days later another sailor, also accompanied by an engineer, fell at the town of Ferrieres, then occupied by the Prussians, when both were made prisoners. In this case, also, the engineer succeeded in making his escape; while the despatches were rescued by a forester and forwarded in safety. At about this date W. de Fonvielle, acting as aeronaut, and taking passengers, made a successful escape, of which he has given a graphic account. He had been baulked by more than one serious contretemps. It had been determined that the departure should be by night, and November 19th being fixed upon, the balloon was in process of inflation under a gentle wind that threatened a travel towards Prussian soil, when, as the moment of departure approached, a large hole was accidentally made in the fabric by the end of the metal pipe, and it was then too late to effect repairs. The next and following days the weather was foul, and the departure was not effected till the 25th, when he sailed away over the familiar but desolated country. He and his companions were fired at, but only when they were well beyond range, and in less than two hours the party reached Louvain, beyond Brussels, some 180 English miles in a direct line from their starting point. This was the day after the "Ville d'Orleans" balloon had made the record voyage and distance of all the siege, falling in Norway, 600 miles north of Christiania, after a flight of fifteen hours. At the end of November, when over thirty escape voyages had been made, two fatal disasters occurred. A sailor of the name of Prince ascended alone on a moonless night, and at dawn, away on the north coast of Scotland, some fishermen sighted a balloon in the sky dropping to the westward in the ocean. The only subsequent trace of this balloon was a bag of despatches picked up in the Channel. Curiously enough, two days later almost the same story was repeated. Two aeronauts, this time in charge of despatches and pigeons, were carried out to sea and never traced. Undeterred by these disasters, a notable escape was now attempted. An important total eclipse of the sun was to occur in a track crossing southern Spain and Algeria on December 22nd. An enthusiastic astronomer, Janssen, was commissioned by the Academy of Sciences to attend and make observations of this eclipse. But M. Janssen was in Paris, as were also his instruments, and the eclipse track lay nearly a thousand miles away. The one and only possible mode of fulfilling his commission was to try the off-chance afforded by balloon, and this chance he resorted to only twenty days before the eclipse was due. Taking with him the essential parts of a reflecting telescope, and an active young sailor as assistant, he left Paris at 6 a.m. and rose at once to 3,600 feet, dipping again somewhat at sunrise (owing, as he supposed, to loss of heat through radiation), but subsequently ascending again rapidly under the increased altitude of the sun till his balloon attained its highest level of 7,200 feet. From this elevation, shortly after 11 a.m., he sighted the sea, when he commenced a descent which brought him to earth at the mouth of the Loire. It had been fast travelling--some 300 miles in little more than three hours--and the ground wind was strong. Nevertheless, neither passengers nor instruments were injured, and M. Janssen was fully established by the day of eclipse on his observing ground at Oran, on the Algerian coast. It is distressing to add that the phenomenon was hidden by cloud. In the month that followed this splendid venture no fewer than fifteen balloons escaped from Paris, of which four fell into the hands of the enemy, although for greater security all ascents were now being made by night. On January 13th, 1871, a new device for the return post was tried, and, in addition to pigeons, sheep dogs were taken up, with the idea of their being returned to the city with messages concealed within their collars. There is apparently no record of any message having been returned to the town by this ingenious method. On January 24th a balloon, piloted by a sailor, and containing a large freight of letters, fell within the Prussian lines, but the patriotism of the country was strong enough to secure the despatches being saved and entrusted to the safe conveyance of the Post Office. Then followed the total loss of a balloon at sea; but this was destined to be the last, save one, that was to attempt the dangerous mission. The next day, January 28th, the last official balloon left the town, manned by a single sailor, carrying but a small weight of despatches, but ordering the ships to proceed to Dieppe for the revictualling of Paris. Five additional balloons at that time in readiness were never required for the risky service for which they were designed. There can be little doubt that had the siege continued a more elaborate use of balloons would have been developed. Schemes were being mooted to attempt the vastly more difficult task of conveying balloons into Paris from outside. When hostilities terminated there were actually six balloons in readiness for this venture at Lisle, and waiting only for a northerly wind. M. de Fonvielle, possessed of both courage and experience, was prepared to put in practice a method of guiding by a small propelling force a balloon that was being carried by sufficiently favouring winds within a few degrees of its desired goal--and in the case of Paris the goal was an area of some twenty miles in diameter. Within the invested area several attempts were actually made to control balloons by methods of steering. The names of Vert and Dupuy de Lome must here be specially mentioned. The former had elaborated an invention which received much assistance, and was subsequently exhibited at the Crystal Palace. The latter received a grant of L1,600 to perfect a complex machine, having within its gas envelope an air chamber, suggested by the swimming bladder of a fish, having also a sail helm and a propelling screw, to be operated by manual labour. The relation of this invention to others of similar purpose will be further discussed later on. But an actual trial of a dirigible craft, the design of Admiral Labrousse, was made from the Orleans railway station on January 9th. This machine consisted of a balloon of about the standard capacity of the siege balloons, namely some 70,000 cubic feet, fitted with two screws of about 12 feet diameter, but capable of being readily worked at moderate speed. It was not a success. M. Richard, with three sailors, made a tentative ascent, and used their best endeavours to control their vessel, but practically without avail, and the machine presently coming to earth clumsily, a portion of the gear caught in the ground and the travellers were thrown over and roughly dragged for a long distance. Fairly looked at, the aerial post of the siege of Paris must be regarded as an ambitious and, on the whole, successful enterprise. Some two million and a half of letters, amounting in weight to some ten tons, were conveyed through the four months, in addition to which at least an equal weight of other freight was taken up, exclusive of actual passengers, of whom no fewer than two hundred were transported from the beleaguered city. Of these only one returned, seven or eight were drowned, twice this number were taken prisoners, and as many again more or less injured in descents. From a purely financial point of view the undertaking was no failure, as the cost, great as it necessarily became, was, it is said, fairly covered by the postage, which it was possible and by no means unreasonable to levy. The recognised tariff seems to have been 20 centimes for 4 grammes, or at the rate of not greatly more than a shilling per English ounce. Surely hardly on a par with fame in prices in a time of siege. It has already been stated that the defenders of Paris did not derive substantial assistance from the services of such a reconnoitring balloon as is generally used in warfare at every available opportunity. It is possible that the peculiar circumstances of the investment of the town rendered such reconnaissance of comparatively small value. But, at any rate, it seems clear that due opportunity was not given to this strategic method. M. Giffard, who at the commencement of the siege was in Paris, and whose experience with a captive balloon was second to none, made early overtures to the Government, offering to build for L40,000 a suitable balloon, capable of raising forty persons to a height of 3,000 feet. Forty aerial scouts, it may be said, are hardly needed for purposes of outlook at one time; but it appears that this was not the consideration which stood in the way of M. Giffard's offer being accepted. According to M. de Fonvielle, the Government refused the experienced aeronaut's proposal on the ground that he required a place in the Champs Elysees, "which it would be necessary to clear of a few shrubs"! CHAPTER XIX. THE TRAGEDY OF THE ZENITH--THE NAVIGABLE BALLOON The mechanical air ship had, by this time, as may be inferred, begun seriously to occupy the attention of both theoretical and practical aeronauts. One of the earliest machines deserving of special mention was designed by M. Giffard, and consisted of an elongated balloon, 104 feet in length and 39 feet in greatest diameter, furnished with a triangular rudder, and a steam engine operating a screw. The fire of the engine, which burned coke, was skilfully protected, and the fuel and water required were taken into calculation as so much ballast to be gradually expended. In this vessel, inflated only with coal gas, and somewhat unmanageable and difficult to balance, the enthusiastic inventor ascended alone from the Hippodrome and executed sundry desired movements, not unsuccessfully. But the trial was not of long duration, and the descent proved both rapid and perilous. Had the trial been made in such a perfect calm as that which prevailed when certain subsequent inventions were tested, it was considered that M. Giffard's vessel would have been as navigable as a boat in the water. This unrivalled mechanician, after having made great advances in the direction of high speed engines of sufficient lightness, proceeded to design a vastly improved dirigible balloon, when his endeavours were frustrated by blindness. As has been already stated, M. Dupuy de Lome, at the end of the siege of Paris, was engaged in building a navigable balloon, which, owing to the unsettled state of affairs in France, did not receive its trial till two years later. This balloon, which was inflated with pure hydrogen, was of greater capacity than that of M. Giffard, being cigar shaped and measuring 118 feet by 48 feet. It was also provided with an ingenious arrangement consisting of an internal air bag, capable of being either inflated or discharged, for the purpose of keeping the principal envelope always distended, and thus offering the least possible resistance to the wind. The propelling power was the manual labour of eight men working the screw, and the steerage was provided for by a triangular rudder. The trial, which was carried out without mishap, took place in February, 1872, in the Fort of Vincennes, under the personal direction of the inventor, when it was found that the vessel readily obeyed the helm, and was capable of a speed exceeding six miles an hour. It was not till nine years after this that the next important trial with air ships was made. The brothers Tissandier will then be found taking the lead, and an appalling incident in the aeronautical career of one of these has now to be recorded. In the spring of 1875, and with the co-operation of French scientific societies, it was determined to make two experimental voyages in a balloon called the "Zenith," one of these to be of long duration, the other of great height. The first of these had been successfully accomplished in a flight of twenty-four hours' duration from Paris to Bordeaux. It was now April the 15th, and the lofty flight was embarked upon by M. Gaston Tissandier, accompanied by MM. Croce-Spinelli and Sivel. Under competent advice, provision for respiration on emergency was provided in three small balloons, filled with a mixture of air and oxygen, and fitted with indiarubber hose pipes, which would allow the mixture, when inhaled, to pass first through a wash bottle containing aromatic fluid. The experiments determined on included an analysis of the proportion of carbonic acid gas at different heights by means of special apparatus; spectroscopic observations, and the readings registered by certain barometers and thermometers. A novel and valuable experiment, also arranged, was that of testing the internal temperature of the balloon as compared with that of the external air. Ascending at 11.30 a.m. under a warm sun, the balloon had by 1 p.m. reached an altitude of 16,000 feet, when the external air was at freezing point, the gas high in the balloon being 72 degrees, and at the centre 66 degrees. Ere this height had been fully reached, however, the voyagers had begun to breathe oxygen. At 11.57, an hour previously, Spinelli had written in his notebook, "Slight pain in the ears--somewhat oppressed--it is the gas." At 23,000 feet Sivel wrote in his notebook, "I am inhaling oxygen--the effect is excellent," after which he proceeded to urge the balloon higher by a discharge of ballast. The rest of the terrible narrative has now to be taken from the notes of M. Tissandier, and as these constitute one of the most thrilling narratives in aeronautical records we transcribe them nearly in full, as given by Mr. Glaisher:-- "At 23,000 feet we were standing up in the car. Sivel, who had given up for a moment, is re-invigorated. Croce-Spinelli is motionless in front of me.... I felt stupefied and frozen. I wished to put on my fur gloves, but, without being conscious of it, the action of taking them from my pocket necessitated an effort that I could no longer make.... I copy, verbatim, the following lines which were written by me, although I have no very distinct remembrance of doing so. They are traced in a hardly legible manner by a hand trembling with cold: 'My hands are frozen. I am all right. We are all all right. Fog in the horizon, with little rounded cirrus. We are ascending. Croce pants; he inhales oxygen. Sivel closes his eyes. Croce also closes his eyes.... Sivel throws out ballast'--these last words are hardly readable. Sivel seized his knife and cut successively three cords, and the three bags emptied themselves and we ascended rapidly. The last remembrance of this ascent which remains clear to me relates to a moment earlier. Croce-Spinelli was seated, holding in one hand a wash bottle of oxygen gas. His head was slightly inclined and he seemed oppressed. I had still strength to tap the aneroid barometer to facilitate the movement of the needle. Sivel had just raised his hand towards the sky. As for myself, I remained perfectly still, without suspecting that I had, perhaps, already lost the power of moving. About the height of 25,000 feet the condition of stupefaction which ensues is extraordinary. The mind and body weaken by degrees, and imperceptibly, without consciousness of it. No suffering is then experienced; on the contrary, an inner joy is felt like an irradiation from the surrounding flood of light. One becomes indifferent. One thinks no more of the perilous position or of danger. One ascends, and is happy to ascend. The vertigo of the upper regions is not an idle word; but, so far as I can judge from my personal impression, vertigo appears at the last moment; it immediately precedes annihilation, sudden, unexpected, and irresistible. "When Sivel cut away the bags of ballast at the height of about 24,000 feet, I seemed to remember that he was sitting at the bottom of the car, and nearly in the same position as Croce-Spinelli. For my part, I was in the angle of the car, thanks to which support I was able to hold up; but I soon felt too weak even to turn my head to look at my companions. Soon I wished to take hold of the tube of oxygen, but it was impossible to raise my arm. My mind, nevertheless, was quite clear. I wished to explain, 'We are 8,000 metres high'; but my tongue was, as it were, paralysed. All at once I closed my eyes, and, sinking down inert, became insensible. This was about 1.30 p.m. At 2.8 p.m. I awoke for a moment, and found the balloon rapidly descending. I was able to cut away a bag of ballast to check the speed and write in my notebook the following lines, which I copy: "'We are descending. Temperature, 3 degrees. I throw out ballast. Barometer, 12.4 inches. We are descending. Sivel and Croce still in a fainting state at the bottom of the car. Descending very rapidly.' "Hardly had I written these lines when a kind of trembling seized me, and I fell back weakened again. There was a violent wind from below, upwards, denoting a very rapid descent. After some minutes I felt myself shaken by the arm, and I recognised Croce, who had revived. 'Throw out ballast,' he said to me, 'we are descending '; but I could hardly open my eyes, and did not see whether Sivel was awake. I called to mind that Croce unfastened the aspirator, which he then threw overboard, and then he threw out ballast, rugs, etc. "All this is an extremely confused remembrance, quickly extinguished, for again I fell back inert more completely than before, and it seemed to me that I was dying. What happened? It is certain that the balloon, relieved of a great weight of ballast, at once ascended to the higher regions. "At 3.30 p.m. I opened my eyes again. I felt dreadfully giddy and oppressed, but gradually came to myself. The balloon was descending with frightful speed and making great oscillations. I crept along on my knees, and I pulled Sivel and Croce by the arm. 'Sivel! Croce!' I exclaimed, 'Wake up!' My two companions were huddled up motionless in the car, covered by their cloaks. I collected all my strength, and endeavoured to raise them up. Sivel's face was black, his eyes dull, and his mouth was open and full of blood. Croce's eyes were half closed and his mouth was bloody. "To relate what happened afterwards is quite impossible. I felt a frightful wind; we were still 9,700 feet high. There remained in the car two bags of ballast, which I threw out. I was drawing near the earth. I looked for my knife to cut the small rope which held the anchor, but could not find it. I was like a madman, and continued to call 'Sivel! Sivel!' By good fortune I was able to put my hand upon my knife and detach the anchor at the right moment. The shock on coming to the ground was dreadful. The balloon seemed as if it were being flattened. I thought it was going to remain where it had fallen, but the wind was high, and it was dragged across fields, the anchor not catching. The bodies of my unfortunate friends were shaken about in the car, and I thought every moment they would be jerked out. At length, however, I seized the valve line, and the gas soon escaped from the balloon, which lodged against a tree. It was then four o'clock. On stepping out, I was seized with a feverish attack, and sank down and thought for a moment that I was going to join my friends in the next world; but I came to. I found the bodies of my friends cold and stiff. I had them put under shelter in an adjacent barn. The descent of the 'Zenith' took place in the plains 155 miles from Paris as the crow flies. The greatest height attained in this ascent is estimated at 28,000 feet." It was in 1884 that the brothers Tissandier commenced experiments with a screw-propelled air ship resembling in shape those constructed by Giffard and Dupuy de Lome, but smaller, measuring only 91 feet by 30 feet, and operated by an electric motor placed in circuit with a powerful battery of bichromate cells. Two trials were made with this vessel in October, 1883, and again in the following September, when it proved itself capable of holding its course in calm air and of being readily controlled by the rudder. But, ere this, a number of somewhat similar experiments, on behalf of the French Government, had been entered upon by Captains Renard and Krebs at Chalais-Meudon. Their balloon may be described as fish-shaped, 165 feet long, and 27.5 feet in principal diameter. It was operated by an electric motor, which was capable of driving a screw of large dimensions at forty-eight revolutions per minute. At its first trial, in August, 1884, in dead calm, it attained a velocity of over twelve miles per hour, travelling some two and a half miles in a forward direction, when, by application of the rudder and judicious management, it was manoeuvred homewards, and practically brought to earth at the point of departure. A more important trial was made on the 12th of the following month, and was witnessed by M. Tissandier, according to whom the aerostat conveying the inventors ascended gently and steadily, drifting with an appreciable breeze until the screw was set in motion and the helm put down, when the vessel was brought round to the wind and held its own until the motor, by an accident, ceased working. A little later the same air ship met with more signal success. On one occasion, starting from Chalais-Meudon, it took a direct course to the N.E., crossing the railway and the Seine, where the aeronauts, stopping the screw, ascertained the velocity of the wind to be approximately five miles an hour. The screw being again put in motion, the balloon was steered to the right, and, following a path parallel to its first, returned to its point of departure. Starting again the same afternoon, it was caused to perform a variety of aerial evolutions, and after thirty-five minutes returned once more to its starting place. A tabular comparison of the four navigable balloons which we have now described has been given as follows:-- Date. Name. Motor. Vel. p. Sec. 1852 M. Henri Giffard Steam engine 13.12 ft. 1872 M. Dupuy de Lome Muscular force 9.18 ft. 1883 MM. Tissandier Electric motor 9.84 ft. 1884 MM. Renard & Krebs Electric motor 18.04 ft. About this period, that is in 1883, and really prior to the Meudon experiments, there were other attempts at aerial locomotion not to be altogether passed over, which were made also in France, but financed by English money. The experiments were performed by Mr. F. A. Gower, who, writing to Professor Tyndall, claims to have succeeded in "driving a large balloon fairly against the wind by steam power." A melancholy interest will always belong to these trials from the fact that Mr. Gower was subsequently blown out to sea with his balloon, leaving no trace behind. At this stage it will be well to glance at some of the more important theories which were being mooted as to the possibility of aerial locomotion properly so called. Broadly, there were two rival schools at this time. We will call them the "lighter-than-air-ites" and the "heavier-than-air-ites," respectively. The former were the advocates of the air vessel of which the balloon is a type. The latter school maintained that, as birds are heavier than air, so the air locomotive of the future would be a machine itself heavier than air, but capable of being navigated by a motor yet to be discovered, which would develop proportionate power. Sir H. Maxim's words may be aptly quoted here. "In all Nature," he says, "we do not find a single balloon. All Nature's flying machines are heavier than the air, and depend altogether upon the development of dynamic energy." The faculty of soaring, possessed by many birds, of which the albatross may be considered a type, led to numerous speculations as to what would constitute the ideal principle of the air motor. Sir G. Cayley, as far back as 1809, wrote a classical article on this subject, without, however, adding much to its elucidation. Others after his time conceived that the bird, by sheer habit and practice, could perform, as it were, a trick in balancing by making use of the complex air streams varying in speed and direction that were supposed to intermingle above. Mr. R. A. Proctor discusses the matter with his usual clear-sightedness. He premises that the bird may, in actual fact, only poise itself for some ten minutes--an interval which many will consider far too small--without flap of the wings, and, while contending that the problem must be simply a mechanical one, is ready to admit that "the sustaining power of the air on bodies of a particular form travelling swiftly through it may be much greater or very different in character from what is supposed." In his opinion, it is a fact that a flat body travelling swiftly and horizontally will sink towards the ground much more slowly than a similar body moving similarly but with less speed. In proof of this he gives the homely illustration of a flat stone caused to make "ducks and drakes." Thus he contends that the bird accomplishes its floating feat simply by occasional powerful propulsive efforts, combined with perfect balance. From which he deduces the corollary that "if ever the art of flying, or rather of making flying machines, is attained by man, it will be by combining rapid motion with the power of perfect balancing." It will now appear as a natural and certain consequence that a feature to be introduced by experimentalists into flying machines should be the "Aeroplane," or, in other words, a plane which, at a desired angle, should be driven at speed through the air. Most notable attempts with this expedient were now shortly made by Hiram Maxim, Langley, and others. But, contemporaneously with these attempts, certain feats with the rival aerostat--the balloon--were accomplished, which will be most fittingly told in this place. CHAPTER XX. A CHAPTER OF ACCIDENTS. It will have been gathered from what has been already stated that the balloonist is commonly in much uncertainty as to his precise course when he is above the clouds, or when unable from darkness to see the earth beneath him. With a view of overcoming this disadvantage some original experiments were suggested by a distinguished officer, who during the seventies had begun to interest himself in aeronautics. This was Captain Burnaby. His method was to employ two small silk parachutes, which, if required, might carry burning magnesium wires, and which were to be attached to each other by a length of silk thread. On dropping one parachute, it would first partake of the motion of the balloon, but would presently drop below, when the second parachute would be dismissed, and then an imaginary line drawn between the two bodies was supposed to betray the balloon's course. It should be mentioned, however, that if a careful study is made of the course of many descending parachutes it will be found that their behaviour is too uncertain to be relied upon for such a purpose as the above. They will often float behind the balloon's wake, but sometimes again will be found in front, and sometimes striking off in some side direction, so wayward and complex are the currents which control such small bodies. Mr. Glaisher has stated that a balloon's course above the clouds may be detected by observing the grapnel, supposed to be hanging below the car, as this would be seen to be out of the vertical as the balloon drifted, and thus serve to indicate the course. However this may be, the most experienced sky sailors will be found to be in perplexity as to their direction, as also their speed, when view of the earth is obscured. But Captain Burnaby is associated notably with the adventurous side of ballooning, the most famous of his aerial exploits being, perhaps, that of crossing the English Channel alone from Dover on March 23rd, 1882. Outwardly, he made presence of sailing to Paris by sky to dine there that evening; inwardly, he had determined to start simply with a wind which bid fair for a cross-Channel trip, and to take whatever chances it might bring him. Thus, at 10.30 a.m., just as the mail packet left the pier, he cast off with a lifting power which rapidly carried him to a height of 2,000 feet, when he found his course to be towards Folkestone. But by shortly after 11 o'clock he had decided that he was changing his direction, and when, as he judged, some seven miles from Boulogne, the wind was carrying him not across, but down the Channel. Then, for nearly four hours, the balloon shifted about with no improvement in the outlook, after which the wind fell calm, and the balloon remained motionless at 2,000 feet above the sea. This state of things continuing for an hour, the Captain resolved on the heroic expedient of casting out all his ballast and philosophically abiding the issue. The manoeuvre turned out a happy one, for the balloon, shooting up to 11,000 feet, caught a current, on which it was rapidly carried towards and over the main land; and, when twelve miles beyond Dieppe, it became easy to descend to a lower level by manipulation of the valve, and finally to make a successful landing in open country beyond. A few years before, an attempt to cross the Channel from the other side ended far more disastrously. Jules Duruof, already mentioned as having piloted the first runaway balloon from beleaguered Paris, had determined on an attempt to cross over to England from Calais; and, duly advertising the event, a large concourse assembled on the day announced, clamouring loudly for the ascent. But the wind proved unsuitable, setting out over the North Sea, and the mayor thought fit to interfere, and had the car removed so as to prevent proceedings. On this the crowd grew impatient, and Duruof, determining to keep faith with them, succeeded by an artifice in regaining his car, which he hastily carried back to the balloon, and immediately taking his seat, and accompanied by his wife, the intrepid pair commenced their bold flight just as the shades of evening were settling down. Shortly the balloon disappeared into the gathering darkness, and then for three days Calais knew no more of balloon or balloonists. Neither could the voyagers see aught for certain of their own course, and thus through the long night hours their attention was wholly needed, without chance of sleep, in closely watching their situation, lest unawares they should be borne down on the waves. When morning broke they discovered that they were still being carried out over the sea on a furious gale, being apparently off the Danish coast, with the distant mountains of Norway dimly visible on the starboard bow. It was at this point, and possibly owing to the chill commonly experienced aloft soon after dawn, that the balloon suddenly took a downward course and plunged into the sea, happily, however, fairly in the track of vessels. Presently a ship came in sight, but cruelly kept on its course, leaving the castaways in despair, with their car fast succumbing to the waves. Help, nevertheless, was really at hand. The captain of an English fishing smack, the Grand Charge, had sighted the sinking balloon, and was already bearing down to the rescue. It is said that when, at length, a boat came alongside as near as it was possible, Madame Duruof was unable to make the necessary effort to jump on board, and her husband had to throw her into the arms of the sailors. A fitting sequel to the story comes from Paris, where the heroic couple, after a sojourn in England, were given a splendid reception and a purse of money, with which M. Duruof forthwith constructed a new balloon, named the "Ville de Calais." On the 4th of March, 1882, the ardent amateur balloonist, Mr. Simmons, had a narrow escape in circumstances somewhat similar to the above. He was attempting, in company with Colonel Brine, to cross the Channel from Canterbury, when a change of wind carried them out towards the North Sea. Falling in the water, they abandoned their balloon, but were rescued by the mail packet Foam. The same amateur aeronaut met with an exciting experience not long after, when in company with Sir Claude C. de Crespigny. The two adventurers left Maldon, in Essex, at 11 p.m., on an August night, and, sailing at a great height out to sea, lost all sight of land till 6 a.m. the next morning, when, at 17,000 feet altitude, they sighted the opposite coast and descended in safety near Flushing. Yet another adventure at sea, and one which proved fatal and unspeakably regrettable, occurred about this time, namely, on the 10th of December, 1881, when Captain Templer, Mr. W. Powell, M.P., and Mr. Agg-Gardner ascended from Bath. We prefer to give the account as it appears in a leading article in the Times for December 13th of that year. After sailing over Glastonbury, "Crewkerne was presently sighted, then Beaminster. The roar of the sea gave the next indication of the locality to which the balloon had drifted and the first hint of the possible perils of the voyage. A descent was now effected to within a few hundred feet of earth, and an endeavour was made to ascertain the exact position they had reached. The course taken by the balloon between Beaminster and the sea is not stated in Captain Templer's letter. The wind, as far as we can gather, must have shifted, or different currents of air must have been found at the different altitudes. What Captain Templer says is that they coasted along to Symonsbury, passing, it would seem, in an easterly direction and keeping still very near to the earth. Soon after they had left Symonsbury, Captain Templer shouted to a man below to tell them how far they were from Bridport, and he received for answer that Bridport was about a mile off. The pace at which the balloon was moving had now increased to thirty-five miles an hour. The sea was dangerously close, and a few minutes in a southerly current of air would have been enough to carry them over it. They seem, however, to have been confident in their own powers of management. They threw out ballast, and rose to a height of 1,500 feet, and thence came down again only just in time, touching the ground at a distance of about 150 yards from the cliff. The balloon here dragged for a few feet, and Captain Templer, who had been letting off the gas, rolled out of the car, still holding the valve line in his hand. This was the last chance of a safe escape for anybody. The balloon, with its weight lightened, went up about eight feet. Mr. Agg-Gardner dropped out and broke his leg. Mr. Powell now remained as the sole occupant of the car. Captain Templer, who had still hold of the rope, shouted to Mr. Powell to come down the line. This he attempted to do, but in a few seconds, and before he could commence his perilous descent, the line was torn out of Captain Templer's hands. All communication with the earth was cut off, and the balloon rose rapidly, taking Mr. Powell with it in a south-easterly direction out to sea." It was a few seasons previous to this, namely, on the 8th of July, 1874, when Mr. Simmons was concerned in a balloon fatality of a peculiarly distressing nature. A Belgian, Vincent de Groof, styling himself the "Flying Man," announced his intention of descending in a parachute from a balloon piloted by Mr. Simmons, who was to start from Cremorne Gardens. The balloon duly ascended, with De Groof in his machine suspended below, and when over St. Luke's Church, and at a height estimated at 80 feet, it is thought that the unfortunate man overbalanced himself after detaching his apparatus, and fell forward, clinging to the ropes. The machine failed to open, and De Groof was precipitated into Robert Street, Chelsea, expiring almost immediately. The porter of Chelsea Infirmary, who was watching the balloon, asserted that he fancied the falling man called out twice, "Drop into the churchyard; look out!" Mr. Simmons, shooting upwards in his balloon, thus suddenly lightened, to a great height, became insensible, and when he recovered consciousness found himself over Victoria Park. He made a descent, without mishap, on a line of railway in Essex. On the 19th of August, 1887, occurred an important total eclipse of the sun, the track of which lay across Germany, Russia, Western Siberia, and Japan. At all suitable stations along the shadow track astronomers from all parts of the world established themselves; but at many eclipses observers had had bad fortune owing to the phenomenon at the critical moment being obscured. And on this account one astronomer determined on measures which should render his chances of a clear view a practical certainty. Professor Mendeleef, in Russia, resolved to engage a balloon, and by rising above the cloud barrier, should there be one, to have the eclipse all to himself. It was an example of fine enthusiasm, which, moreover, was presently put to a severe and unexpected test, for the balloon, when inflated, proved unable to take up both the aeronaut and the astronomer, whereupon the latter, though wholly inexperienced, had no alternative but to ascend alone, which, either by accident or choice, he actually did. Shooting up into space, he soon reached an altitude of 11,500 feet, where he obtained, even if he did not enjoy, an unobstructed view of the Corona. It may be supposed, however, that, owing to the novelty of his situation, his scientific observations may not have been so complete as they would have been on terra firma. In the same month an attempt to reach a record height was made by MM. Jovis and Mallet at Paris, with the net result that an elevation of 23,000 feet was reached. It will have been noted that the difficulty through physical exhaustion of inhaling oxygen from either a bag or cylinder is a serious matter not easily overcome, and it has been suggested that the helmet invented by M. Fleuss might prove of value. This contrivance, which has scarcely attracted the attention it has merited, provides a receptacle for respiration, containing oxygen and certain purifying media, by means of which the inventor was able to remain for hours under water without any communication with the outward air. About the period at which we have now arrived two fatal accidents befel English aeronauts. We have related how Maldon, in Essex, was associated with one of the more adventurous exploits in Mr. Simmons's career. It was fated also to be associated with the voyage with which his career closed. On August 27th, 1888, he ascended from Olympia in company with Mr. Field, of West Brighton, and Mr. Myers, of the Natural History Museum, with the intention, if practicable, of crossing to Flanders; and the voyage proceeded happily until the neighbourhood of Maldon was reached, when, as the sea coast was in sight, and it was already past five o'clock, it appeared prudent to Mr. Simmons to descend and moor the balloon for the night. Some labourers some three miles from Maldon sighted the balloon coming up at speed, and at the same time descending until its grapnel commenced tearing through a field of barley, when ballast was thrown out, causing the balloon to rise again towards and over some tall elms, which became the cause of the disaster which followed. The grapnel, catching in the upper boughs of one of these trees, held fast, while the balloon, borne by the force of a strong wind, was repeatedly blown down to earth with violence, rebounding each time to a considerable height, only to be flung down again on the same spot. After three or four impacts the balloon is reported to have burst with a loud noise, when high in the air, the silk being blown about over the field, and the car and its occupants dashed to the ground. Help was unavailing till this final catastrophe, and when, at length, the labourers were able to extricate the party, Mr. Simmons was found with a fractured skull and both companions badly injured. Four summers later, June 30th, 1892, Captain Dale, the aeronaut to the Crystal Palace, was announced to make an ascent from the usual balloon grounds, weather permitting. Through the night and morning a violent storm prevailed, and it was contemplated that the exhibition would be withdrawn; but the wind abating in the afternoon, the inflation was proceeded with, and the ascent took place shortly before 6 p.m., not, however, before a large rent had been discovered and repaired as far as possible by Mrs. Dale. As passengers, there ascended the Captain's son William, aged nineteen, Mr. J. Macintosh, and Mr. Cecil Shadbolt. When the balloon had reached an altitude estimated at 600 feet the onlookers were horrified to see it suddenly collapse, a large rent having developed near the top part of the silk, from which the gas "rushed out in a dense mass, allowing the balloon to fall like a rag." The occupants of the car were seen to be throwing out everything madly, even wrenching the buttons from their clothing. All, however, with little avail, for the balloon fell "with a sickening thud," midway between the Maze and lower lake. All were found alive; but Captain Dale, who had alighted on his back, died in a few minutes; Mr. Shadbolt succumbed later, and both remaining passengers sustained terrible injuries. Few balloon mishaps, unattended with fatal results, have proved more exciting than the following. A large party had ascended from Belfast, in a monster balloon, under the guidance of Mr. Coxwell, on a day which was very unfit for the purpose by reason of stormy weather. A more serious trouble than the wind, however, lay in several of the passengers themselves, who seem to have been highly excitable Irishmen, incapable at the critical moment of quietly obeying orders. The principal hero of the story, a German. Mr. Runge, in writing afterwards to the Ulster Observer, entirely exonerates Mr. Coxwell from any blame, attributing his mischances solely to the reprehensible conduct of his companions. On approaching the ground, Mr. Coxwell gave clear instructions. The passengers were to sit down in an unconstrained position facing each other, and be prepared for some heavy shocks. Above all things they were to be careful to get out one by one, and on no account to leave hold of the car. Many of the passengers, however, refused to sit down, and, according to Mr. Runge, "behaved in the wildest manner, losing completely their self-control. Seizing the valve rope themselves, they tore it away from its attachment, the stronger pushing back the weaker, and refusing to lend help when they had got out. In consequence of this the car, relieved of their weight, tore away from the grasp of Mr. Coxwell and those who still clung to it, and rose above the trees, with Mr. Runge and one other passenger, Mr. Halferty, alone within. As the balloon came earthwards again, they shouted to the countrymen for succour, but without the slightest avail, and presently, the anchor catching, the car struck the earth with a shock which threw Mr. Halferty out on the ground, leaving Mr. Runge to rise again into the air, this time alone." He thus continues the story:-- "The balloon moved on, very soon, in a horizontal direction straight towards the sea, which we were then rapidly nearing. Coming to a farm, I shouted out to the people standing there. Some women, with their quick humane instincts, were the first to perceive my danger, and exhorted the men to hurry to my assistance, they themselves running as fast as they could to tender what little help they might be able to give me. The anchor stuck in a willow tree. I shouted out to the people below to secure the cable and anchor by ropes, which they did. The evening was now beautifully still, the breeze had died away, and the balloon was swinging calmly at her moorings above the farmhouse. One of the men asked me whether I had a rope with me, and how I intended to get out. I told them only to take care of the cable, because the balloon would settle down by herself before long. I was congratulating myself on a speedy escape from my dangerous position. I had not counted on the wind. A breeze in about six or eight minutes sprang up, tossed the balloon about like a large sail, then a crash, and--the anchor was loose again. It tore through the trees, flinging limbs and branches about like matches. It struck the roof of the farmhouse, splintering the chimneys and tiles like glass. "On I went; I came near another farm; shouted out for help, and told the men to secure the anchor to the foot of a large tree close by. The anchor was soon made fast, but this was only a momentary relief. The breeze again filled the half-empty balloon like a sail, there was a severe strain on the cable, then a dull sound, and a severe concussion of the basket--the cable, strange fatality, had broken, and the anchor, my last and only hope, was gone. I was now carried on in a straight direction towards the sea, which was but a short distance ahead. The anchor being lost I gave up all hope. I sat down resigned in the car, and prepared for the end. All at once I discovered that a side current was drifting me towards the mountain; the car struck the ground, and was dashing along at a fearful rate, knocking down stone fences and breaking everything it came in contact with in its wild career. By-and-by the knocks became less frequent. We were passing over a cultivated country, and the car was, as it were skimming the surface and grazing the top of the hedges. I saw a thick hawthorn hedge at some distance before me, and the balloon rapidly sweeping towards it. That was my only chance. I rushed to the edge of the car and flung myself down upon the hedge." CHAPTER XXI. THE COMING OF THE FLYING MACHINE. In the early nineties the air ship was engaging the attention of many inventors, and was making important strides in the hands of Mr. Maxim. This unrivalled mechanician, in stating the case, premises that a motive power has to be discovered which can develop at least as much power in proportion to its weight as a bird is able to develop. He asserts that a heavy bird, with relatively small wings--such as a goose--carries about 150 lb. to the horse power, while the albatross or the vulture, possessed of proportionately greater winged surface, can carry about 250 lbs. per horse power. Professor Langley, of Washington, working contemporaneously, but independently of Mr. Maxim, had tried exhaustive experiments on a rotating arm (characteristically designated by Mr. Maxim a "merry-go-round"), thirty feet long, applying screw propellers. He used, for the most part, small planes, carrying loads of only two or three pounds, and, under these circumstances, the weight carried was at the rate of 250 lbs. per horse power. His important statements with regard to these trials are that one-horse power will transport a larger weight at twenty miles an hour than at ten, and a still larger at forty miles than at twenty, and so on; that "the sustaining pressure of the air on a plane moving at a small angle of inclination to a horizontal path is many times greater than would result from the formula implicitly given by Newton, while, whereas in land or marine transport increased speed is maintained only by a disproportionate expenditure of power within the limits of experiment, in aerial horizontal transport the higher speeds are more economical of power than the lower ones." This Mr. Maxim is evidently ready to endorse, stating, in his own words, that birds obtain the greater part of their support by moving forward with sufficient velocity so as to be constantly resting on new air, the inertia of which has not been disturbed. Mr. Maxim's trials were on a scale comparable with all his mechanical achievements. He employed for his experiments a rotating arm, sweeping out a circle, the circumference of which was 200 feet. To the end of this arm he attached a cigar-shaped apparatus, driven by a screw, and arranged in such a manner that aero-planes could be attached to it at any angle. These planes were on a large scale, carrying weights of from 20 lbs. to 100 lbs. With this contrivance he found that, whatever push the screw communicated to the aero-plane, "the plane would lift in a vertical direction from ten to fifteen times as much as the horizontal push that it received from the screw, and which depended upon the angle at which the plane was set, and the speed at which the apparatus was travelling through the air." Next, having determined by experiment the power required to perform artificial flight, Mr. Maxim applied himself to designing the requisite motor. "I constructed," he states, "two sets of compound engines of tempered steel, all the parts being made very light and strong, and a steam generator of peculiar construction, the greater part of the heating surface consisting of small and thin copper tubes. For fuel I employed naphtha." This Mr. Maxim wrote in 1892, adding that he was then experimenting with a large machine, having a spread of over 100 feet. Labour, skill, and money were lavishly devoted henceforward to the great task undertaken, and it was not long before the giant flying machine, the outcome of so much patient experimenting, was completed and put to a practical trial. Its weight was 7,500 lbs. The screw propellers were nearly 18 feet in diameter, each with two blades, while the engines were capable of being run up to 360 horse power. The entire machine was mounted on an inner railway track of 9 feet and an outer of 35 feet gauge, while above there was a reversed rail along which the machine would begin to run so soon as with increase of speed it commenced to lift itself off the inner track. In one of the latest experiments it was found that when a speed of 42 miles an hour was attained all the wheels were running on the upper track, and revolving in the opposite direction from those on the lower track. However, after running about 1,000 feet, an axle tree doubled up, and immediately afterwards the upper track broke away, and the machine, becoming liberated, floated in the air, "giving those on board a sensation of being in a boat." The experiment proved conclusively to the inventor that a machine could be made on a large scale, in which the lifting effect should be considerably greater than the weight of the machine, and this, too, when a steam engine was the motor. When, therefore, in the years shortly following, the steam engine was for the purposes of aerial locomotion superseded by the lighter and more suitable petrol engine, the construction of a navigable air ship became vastly more practicable. Still, in Sir H. Maxim's opinion, lately expressed, "those who seek to navigate the air by machines lighter than the air have come, practically, to the end of their tether," while, on the other hand, "those who seek to navigate the air with machines heavier than the air have not even made a start as yet, and the possibilities before them are very great indeed." As to the assertion that the aerial navigators last mentioned "have not even made a start as yet," we can only say that Sir H. Maxim speaks with far too much modesty. His own colossal labours in the direction of that mode of aerial flight, which he considers to be alone feasible, are of the first importance and value, and, as far as they have gone, exhaustive. Had his experiments been simply confined to his classical investigations of the proper form of the screw propeller his name would still have been handed down as a true pioneer in aeronautics. His work, however, covers far wider ground, and he has, in a variety of ways, furnished practical and reliable data, which must always be an indispensable guide to every future worker in the same field. Professor Langley, in attacking the same problem, first studied the principle and behaviour of a well-known toy--the model invented by Penaud, which, driven by the tension of india-rubber, sustains itself in the air for a few seconds. He constructed over thirty modifications of this model, and spent many months in trying from these to as certain what he terms the "laws of balancing leading to horizontal flight." His best endeavours at first, however, showed that he needed three or four feet of sustaining surface to a pound of weight, whereas he calculated that a bird could soar with a surface of less than half a foot to the pound. He next proceeded to steam-driven models in which for a time he found an insuperable difficulty in keeping down the weight, which, in practice, always exceeded his calculation; and it was not till the end of 1893 that he felt himself prepared for a fair trial. At this time he had prepared a model weighing between nine and ten pounds, and he needed only a suitable launching apparatus to be used over water. The model would, like a bird, require an initial velocity imparted to it, and the discovery of a suitable apparatus gave him great trouble. For the rest the facilities for launching were supplied by a houseboat moored on the Potomac. Foiled again and again by many difficulties, it was not till after repeated failures and the lapse of many months, when, as the Professor himself puts it, hope was low, that success finally came. It was in the early part of 1896 that a successful flight was accomplished in the presence of Dr. Bell, of telephone fame, and the following is a brief epitome of the account that this accomplished scientist contributed to the columns of Nature:-- "The flying machine, built, apparently, almost entirely of metal, was driven by an engine said to weigh, with fuel and water, about 25 lbs., the supporting surface from tip to tip being 12 or 14 feet. Starting from a platform about 20 feet high, the machine rose at first directly in the face of the wind, moving with great steadiness, and subsequently wheeling in large curves until steam was exhausted, when, from a height of 80 or 100 feet, it shortly settled down. The experiment was then repeated with similar results. Its motion was so steady that a glass of water might have remained unspilled. The actual length of flight each time, which lasted for a minute and a half, exceeded half a mile, while the velocity was between twenty and twenty-five miles an hour in a course that was constantly taking it 'up hill.' A yet more successful flight was subsequently made." But flight of another nature was being courageously attempted at this time. Otto Lilienthal, of Berlin, in imitation of the motion of birds, constructed a flying apparatus which he operated himself, and with which he could float down from considerable elevations. "The feat," he warns tyros, "requires practice. In the beginning the height should be moderate, and the wings not too large, or the wind will soon show that it is not to be trifled with." The inventor commenced with all due caution, making his first attempt over a grass plot from a spring board one metre high, and subsequently increasing this height to two and a half metres, from which elevation he could safely cross the entire grass plot. Later he launched himself from the lower ridges of a hill 250 feet high, when he sailed to a distance of over 250 yards, and this time he writes enthusiastically of his self-taught accomplishment:-- "To those who, from a modest beginning and with gradually increased extent and elevation of flight have gained full control over the apparatus, it is not in the least dangerous to cross deep and broad ravines. It is a difficult task to convey to one who has never enjoyed aerial flight a clear perception of the exhilarating pleasure of this elastic motion. The elevation above the ground loses its terrors, because we have learned by experience what sure dependence may be placed upon the buoyancy of the air." As a commentary to the above we extract the following:--"We have to record the death of Otto Lilienthal, whose soaring machine, during a gliding flight, suddenly tilted over at a height of about 60 feet, by which mishap he met an untimely death on August 9th, 1896." Mr. O. Chanute, C.E. of Chicago, took up the study of gliding flight at the point where Lilienthal left it, and, later, Professor Fitzgerald and others. Besides that invented by Penaud, other aero-plane models demanding mention had been produced by Tatin, Moy, Stringfellow, and Lawrence Hargrave, of Australia, the subsequent inventor of the well-known cellular kite. These models, for the most part, aim at the mechanical solution of the problem connected with the soaring flight of a bird. The theoretical solution of the same problem had been attacked by Professor Langley in a masterly monograph, entitled "The Internal Work of the Wind." By painstaking experiment with delicate instruments, specially constructed, the Professor shows that wind in general, so far from being, as was commonly assumed, mere air put in motion with an approximately uniform velocity in the same strata, is, in reality, variable and irregular in its movements beyond anything which had been anticipated, being made up, in fact, of a succession of brief pulsations in different directions, and of great complexity. These pulsations, he argues, if of sufficient amplitude and frequency, would be capable, by reason of their own "internal work," of sustaining or even raising a suitably curved surface which was being carried along by the main mean air stream. This would account for the phenomenon of "soaring." Lord Rayleigh, discussing the same problem, premises that when a bird is soaring the air cannot be moving uniformly and horizontally. Then comes the natural question, Is it moving in ascending currents? Lord Rayleigh has frequently noticed such currents, particularly above a cliff facing the wind. Again, to quote another eminent authority, Major Baden-Powell, on an occasion when flying one of his own kites, found it getting to so high an angle that it presently rose absolutely overhead, with the string perpendicular. He then took up a heavy piece of wood, which, when tied to the string, began to rise in the air. He satisfied himself that this curious result was solely due to a strong uptake of the air. But, again, Lord Rayleigh, lending support to Professor Langley's argument, points out that the apparent cause of soaring may be the non-uniformity of the wind. The upper currents are generally stronger than the lower, and it is mechanically possible for a bird, taking advantage of two adjacent air streams, different in velocity, to maintain itself in air without effort on its own part. Lord Rayleigh, proceeding to give his views on artificial flight, declares the main problem of the flying machine to be the problem of the aerial plane. He states the case thus:--"Supposing a plane surface to be falling vertically at the rate of four miles an hour, and also moving horizontally at the rate of twenty miles an hour, it might have been supposed that the horizontal motion would make no difference to the pressure on its under surface which the falling plane must experience. We are told, however, that in actual trial the horizontal motion much increases the pressure under the falling plane, and it is this fact on which the possibility of natural and artificial flight depends." Ere this opinion had been stated by Lord Rayleigh in his discourse on "Flight," at the Royal Institution, there were already at work upon the aero-plane a small army of inventors, of whom it will be only possible in a future chapter to mention some. Due reference, however, should here be made to Mr. W. F. Wenham, of Boston, U.S.A., who had been at work on artificial flight for many years, and to whose labours in determining whether man's power is sufficient to raise his own weight Lord Rayleigh paid a high tribute. As far back as 1866 Mr. Wenham had published a paper on aerial locomotion, in which he shows that any imitation by man of the far-extended wings of a bird might be impracticable, the alternative being to arrange the necessary length of wing as a series of aero-planes, a conception far in advance of many theorists of his time. But there had been developments in aerostation in other lines, and it is time to turn from the somewhat tedious technicalities of mechanical flight and the theory or practice of soaring, to another important means for traversing the air--the parachute. This aerial machine, long laid aside, was to lend its aid to the navigation of the air with a reliability never before realised. Professor Baldwin, as he was termed, an American aeronaut, arrived in England in the summer of 1888, and commenced giving a series of exhibitions from the Alexandra Palace with a parachute of his own invention, which, in actual performance, seems to have been the most perfect instrument of the kind up to that time devised. It was said to be about 18 feet in diameter, whereas that of Garnerin, already mentioned, had a diameter of some 30 feet, and was distinctly top-heavy, owing to its being thus inadequately ballasted; for it was calculated that its enormous size would have served for the safe descent, not of one man, but of four or five. Baldwin's parachute, on the contrary, was reckoned to give safe descent to 250 lbs., which would include weight of man and apparatus, and reduce the ultimate fall to one not exceeding 8 feet. The parachute was attached to the ring of a small balloon of 12,000 cubic feet, and the Professor ascended, sitting on a mere sling of rope, which did duty for a car. Mr. Thomas Moy, who investigated the mechanics of the contrivance, estimated that after a drop of 16 feet, the upward pressure, amounting to over 2 lb. per square foot, would act on a surface of not less than 254 square feet. There was, at the time, much foolish comment on the great distance which the parachute fell before it opened, a complete delusion due to the fact that observers failed to see that at the moment of separation the balloon itself sprang upward. CHAPTER XXII. THE STORY OF THE SPENCERS. It has been in the hands of the Spencers that the parachute, as also many other practical details of aeronautics, has been perfected, and some due sketch of the career of this family of eminent aeronauts must be no longer delayed. Charles Green had stood godfather to the youngest son of his friend and colleague, Mr. Edward Spencer, and in later years, as though to vindicate the fact, this same son took up the science of aeronautics at the point where his father had left it. We find his name in the records of the Patent Office of 1868 as the inventor of a manumetric flying machine, and there are accounts of the flying leaps of several hundred feet which he was enabled to take by means of the machine he constructed. Again, in 1882 we find him an inventor, this time of the patent asbestos fire balloon, by means of which the principal danger to such balloons was overcome. At this point it is needful to make mention of the third generation--the several sons who early showed their zeal and aptitude for perpetuating the family tradition. It was from his school playground that the eldest son, Percival, witnessed with intense interest what appeared like a drop floating in the sky at an immense altitude. This proved to be Simmons's balloon, which had just risen to a vast elevation over Cremorne Gardens, after having liberated the unfortunate De Groof, as mentioned in a former chapter. And one may be sure that the terrible reality of the disaster that had happened was not lost on the young schoolboy. But his wish was to become an aeronauts, and from this desire nothing deterred him, so that school days were scarcely over before he began to accompany his father aloft, and in a very few years, i.e. in 1888, he had assumed the full responsibilities of a professional balloonist. It was in this year that Professor Baldwin appeared in England, and it is easy to understand that the parachute became an object of interest to the young Spencer, who commenced on his own account a series of trials at the Alexandra Palace, and it was now, also, that chance good fortune came his way. An Indian gentleman, who was witness of his experiments, and convinced that a favourable field for their further development existed in his own country, proposed to the young aspirant that he should accompany him to India, with equipment suited for the making of a successful campaign. Thus it came about that in the early days of 1889, in the height of the season, Mr. Percival Spencer arrived at Bombay, and at once commenced professional business in earnest. Coal gas being here available, a maiden ascent was quickly arranged, and duly announced to take place at the Government House, Paral, the chief attraction being the parachute descent, the first ever attempted in India. This preliminary exhibition proving in all ways a complete success, Mr. Spencer, after a few repetitions of his performance, repaired to Calcutta; but here great difficulties were experienced in the matter of gas. The coal gas available was inadequate, and when recourse was had to pure hydrogen the supply proved too sluggish. At the advertised hour of departure the balloon was not sufficiently inflated, while the spectators were growing impatient. It was at this critical moment that Mr. Spencer resolved on a surprise. Suddenly casting off the parachute, and seated on a mere sling below the half-inflated balloon, without ballast, without grapnel, and unprovided with a valve, he sailed away over the heads of the multitude. The afternoon was already far advanced, and the short tropical twilight soon gave way to darkness, when the intrepid voyager disappeared completely from sight. Excitement was intense that night in Calcutta, and greater still the next day when, as hour after hour went by, no news save a series of wild and false reports reached the city. Trains arriving from the country brought no intelligence, and telegraphic enquiries sent in all directions proved fruitless. The Great Eastern Hotel, where the young man had been staying, was literally besieged for hours by a large crowd eager for any tidings. Then the Press gave expression to the gloomiest forebodings, and the town was in a fever of unrest. From the direction the balloon had taken it was thought that, even if the aeronaut had descended in safety, he could only have been landed in the jungle of the Sunderbunds, beset with perils, and without a chance of succour. A large reward was offered for reliable information, and orders were issued to every likely station to organise a search. But ere this was fully carried into effect messages were telegraphed to England definitely asserting that Mr. Spencer had lost his life. For all this, after three days he returned to Calcutta, none the worse for the exploit. Then the true tale was unravelled. The balloon had changed its course from S.E. to E. after passing out of sight of Calcutta, and eventually came to earth the same evening in the neighbourhood of Hossainabad, thirty-six miles distant. During his aerial flight the voyager's main trouble had been caused by his cramped position, the galling of his sling seat, and the numbing effect of cold as he reached high altitudes; but, as twilight darkened into gloom, his real anxiety was with respect to his place of landing, for he could with difficulty see the earth underneath. He heard the distant roll of the waters, caused by the numerous creeks which intersect the delta of the Ganges, and when darkness completely shut out the view it was impossible to tell whether he was over land or sea. Fortune favoured him, however, and reaching dry ground, he sprang from his seat, relinquishing at the same moment his hold of the balloon, which instantly disappeared into the darkness. Then his wanderings began. He was in an unknown country, without knowledge of the language, and with only a few rupees in his pocket. Presently, however, seeing a light, he proceeded towards it, but only to find himself stopped by a creek. Foiled more than once in this way, he at length arrived at the dwelling of a family of natives, who promptly fled in terror. To inspire confidence and prove that he was mortal, Mr. Spencer threw his coat over the mud wall of the compound, with the result that, after examination of the garment, he was received and cared for in true native fashion, fed with rice and goat's milk, and allowed the use of the verandah to sleep in. He succeeded in communing with the natives by dint of lead pencil sketches and dumb show, and learned, among other things, that he had descended in a little clearing surrounded by woods, and bounded by tidal creeks, which were infested with alligators. Yet, in the end, the waterways befriended him; for, as he was being ferried across, he chanced on his balloon sailing down on the tide, recovered it, and used the tidal waters for the return journey. The greeting upon his arrival in Calcutta was enthusiastic beyond description from both Europeans and natives. The hero of the adventure was visited by rajahs and notables, who vied with each other in expressions of welcome, in making presents, even inviting him to visit the sacred precincts of their zenanas. The promised parachute descent was subsequently successfully made at Cossipore, and then followed a busy, brilliant season, after which the wanderer returned to England. By September he is in Dublin, and makes the first parachute descent ever witnessed in Ireland; but by November he is in Bombay again, whence, proceeding to Calcutta, he repeats his success of the year before. Next he visits Allahabad, where the same fortune attends him, though his balloon flies away in a temporary escape into the Jumna. By May he is ascending at Singapore, armed here, however, with a cork jacket. Hence, flushed with success, he repairs to the Dutch Indies, and demonstrates to the Dutch officers the use of the balloon in war. As a natural consequence, he is moved up to the seat of the Achinese War in Sumatra, where, his balloon being moored to the rear of an armoured train, an immediate move is made to the front, and orders are forthwith telephoned from various centres to open fire on the enemy. Mr. Spencer, the while accompanied by an officer, makes a captive ascent, in which for some time he is actually under the enemy's fire. The result of this plucky experiment is a most flattering official report. In all the above-mentioned ascents he made his own gas without a hitch. Thence he travels on with the same trusty little 12,000 cubic feet balloon, the same programme, and the same success. This is slightly varied, however, at Kobe, Japan, where his impatient craft fairly breaks away with him, and, soaring high, flies overhead of a man-of-war, and plumps into the water a mile out at sea. But "Smartly" was the word. The ship's crew was beat to quarters, and within one minute a boat was to the rescue. An ascent at Cairo, where he made a parachute descent in sight of the Pyramids and landed in the desert, completed this oriental tour, and home duties necessitated his return to England. Among exploits far too many to enumerate may be mentioned four several occasions when Mr. Percival Spencer has crossed the English Channel. It fell to the lot of the second son, Arthur, to carry fame into fresh fields. In the year 1897 he visited Australia, taking with him two balloons, one of these being a noble craft of 80,000 cubic feet, considerably larger than any balloon used in England, and the singular fate of this aerial monster is deserving of mention. Its trial trip in the new country was arranged to take place on Boxing Day in the Melbourne Exhibition ground, and for the lengthy and critical work of inflation the able assistance of British bluejackets was secured. To all appearance, the main difficulties to be provided against were likely to arise simply from a somewhat inadequate supply of gas, and on this account filling commenced as early as 10 a.m. on the morning of the day previous to the exhibition, and was continued till 6 o'clock in the afternoon, by which time the balloon, being about half full, was staved down with sandbags through the night till 4 o'clock the next morning, when the inflation was again proceeded with without hindrance and apparently under favourable conditions. The morning was beautifully fine, warm, brilliant, and still, and so remained until half-past six, when, with startling rapidity, there blew up a sudden squall known in the country as a "Hot Buster," and in two or three minutes' space a terrific wind storm was sweeping the ground. A dozen men, aiding a dead weight of 220 sandbags, endeavoured to control the plunging balloon, but wholly without avail. Men and bags together were lifted clean up in the air on the windward side, and the silk envelope, not yet completely filled, at once escaped from the net and, flying upwards to a height estimated at 10,000 feet, came to earth again ninety miles away in a score of fragments. Nothing daunted, however, Mr. Spencer at once endeavoured to retrieve his fortunes, and started straightway for the gold-mining districts of Ballarat and Bendigo with a hot-air balloon, with which he successfully gave a series of popular exhibitions of parachute descents. Few aeronauts are more consistently reliable than Mr. Arthur Spencer. A few summers ago in this country he was suddenly called upon to give proof of his prowess and presence of mind in a very remarkable manner. It was at an engagement at Reading, where he had been conducting captive ascents throughout the afternoon, and was requested to conclude the evening with a "right away," in which two passengers had agreed to accompany him. The balloon had been hauled down for the last time, when, by some mistake, the engine used for the purpose proceeded to work its pump without previously disconnecting the hauling gear. The consequence of this was that the cable instantly snapped, and in a moment the large balloon, devoid of ballast, grapnel, or other appliances, and with neck still tied, was free, and started skyward. The inevitable result of this accident must have been that the balloon in a few seconds would rise to a height where the expansion of the imprisoned gas would burst and destroy it. Mr. Spencer, however, was standing near, and, grasping the situation in a moment, caught at the car as it swung upwards, and, getting hold, succeeded in drawing himself up and so climbing into the ring. Quickly as this was done, the balloon was already distended to the point of bursting, and only the promptest release of gas averted catastrophe. Mr. Stanley Spencer made himself early known to the world by a series of parachute descents, performed from the roof of Olympia. It was a bold and sensational exhibition, and on the expiration of his engagement the young athlete, profiting by home training, felt fully qualified to attempt any aerial feat connected with the profession of an aeronaut. And at this juncture an eminent American cyclist, visiting the father's factory, suggested to Stanley a business tour in South America. As an extra attraction it was proposed that a young lady parachutist should be one of the company; so, after a few satisfactory trial exhibitions in England, the party made their way to Rio, Brazil. Here an ascent was arranged, and by the day and hour appointed the balloon was successfully inflated with hydrogen, an enormous concourse collected, and the lady performer already seated in the sling. Then a strange mischance happened. By some means, never satisfactorily explained, the young woman, at the moment of release, slipped from her seat, and the balloon, escaping into the air, turned over and fell among the people, who vindictively destroyed it. Then the crowd grew ungovernable, and threatened the lives of the aeronauts, who eventually were, with difficulty, rescued by the soldiery. This was a bad start; but with a spare balloon a fresh attempt at an ascent was arranged, though, from another cause, with no better success. This time a furious storm arose, before the inflation was completed, and the balloon, carrying away, was torn to ribbons. Yet a third time, with a hot air balloon now, a performance was advertised and successfully carried out; but, immediately after, Mr. Spencer's American friend succumbed to yellow fever, and the young man, being thrown on his own resources, had to fight his own way until his fortunes had been sufficiently restored to return to England. A few months later he set sail for Canada, where for several months he had a most profitable career, on one occasion only meeting with some difficulty. He was giving an exhibition on Prince Edward's Island, not far from the sea, but on a day so calm that he did not hesitate to ascend. On reaching 3,000 feet, however, he was suddenly caught by a strong land breeze, which, ere he could reach the water, had carried him a mile out to sea, and here he was only rescued after a long interval, during which he had become much exhausted in his attempts to save his parachute from sinking. Early in 1892 our traveller visited South Africa with a hot air balloon, and, fortune continuing to favour him, he subsequently returned to Canada, and proceeded thence to the United States and Cuba. It was at Havannah that popular enthusiasm in his favour ran so high that he was presented with a medal by the townsfolk. It was from here also that, a little while after, tidings of his own death reached him, together with most gratifying obituary notices. It would seem that, after his departure, an adventurer, attempting to personate him, met with his death. In November, 1897, he followed his elder brother's footsteps to the East, and exhibited in Calcutta, Singapore, Canton, and also Hong-Kong, where, for the first and only time in his experience, he met with serious accident. He was about to ascend for the ordinary parachute performance with a hot air balloon, which was being held down by about thirty men, one among them being a Chinaman possessed of much excitability and very long finger nails. By means of these latter the man contrived to gouge a considerable hole in the fabric of the balloon. Mr. Spencer, to avoid a disappointment, risked an ascent, and it was not till the balloon had reached 600 feet that the rent developed into a long slit, and so brought about a sudden fall to earth. Alighting on the side of a mountain, Mr. Spencer lay helpless with a broken leg till the arrival of some British bluejackets, who conveyed him to the nearest surgeon, when, after due attention, he was sent home. Other remarkable exploits, which Mr. Stanley Spencer shared with Dr. Berson and with the writer and his daughter, will be recorded later. CHAPTER XXIII. NEW DEPARTURES IN AEROSTATION. After Mr. Coxwell's experiments at Aldershot in 1862 the military balloon, as far as England was concerned, remained in abeyance for nine long years, when the Government appointed a Commission to enquire into its utility, and to conduct further experiments. The members of this committee were Colonel Noble, R.E., Sir F. Abel, Captain Lee, R.E., assisted by Captain Elsdale, R.E., and Captain (now Colonel) Templer. Yet another nine years, however, elapsed before much more was heard of this modernised military engine. But about the beginning of the eighties the Government had become fully alive to the importance of the subject, and Royal Engineers at Woolwich grew busy with balloon manufacture and experiment. Soon "the sky around London became speckled with balloons." The method of making so-called pure hydrogen by passing steam over red-hot iron was fully tested, and for a time gained favour. The apparatus, weighing some three tons, was calculated to be not beyond the carrying powers of three service waggons, while it was capable of generating enough gas to inflate two balloons in twenty-four hours, a single inflation holding good, under favourable circumstances, for a long period. At the Brighton Volunteer Review of 1880, Captain Templer, with nine men, conducted the operations of a captive reconnoitring balloon. This was inflated at the Lewes gas works, and then towed two and a half miles across a river, a railway, and a line of telegraph wires, after which it was let up to a height of 1,500 feet, whence, it was stated, that so good a view was obtained that "every man was clearly seen." Be it remembered, however, that the country was not the South African veldt, and every man was in the striking English uniform of that date. Just at this juncture came the Egyptian War, and it will be recalled that in the beginning of that war balloons were conspicuous by their absence. The difficulties of reconnaissance were keenly felt and commented on, and among other statements we find the following in the war intelligence of the Times:-- "As the want of a balloon equipment has been mentioned in letters from Egypt, it may be stated that all the War Department balloons remain in store at the Royal Dockyard at Woolwich, but have been recently examined and found perfectly serviceable." An assertion had been made to the effect that the nature of the sand in Egypt would impede the transport of the heavy material necessary for inflation. At last, however, the order came for the despatch of the balloon equipment to the front, and though this arrived long after Tel-el-Kebir, yet it is recorded that the first ascent in real active service in the British Army took place on the 25th of March, 1885, at Suakin, and balloons becoming regarded as an all-important part of the equipment of war, they were sent out in the Bechuanaland Expedition under Sir Charles Warren, the supply of gas being shipped to Cape Town in cylinders. It was at this period that, according to Mr. Coxwell, Lord Wolseley made ascents at home in a war balloon to form his own personal opinion of their capabilities, and, expressing this opinion to one of his staff, said that had he been able to employ balloons in the earlier stages of the Soudan campaign the affair would not have lasted as many months as it did years. This statement, however, should be read in conjunction with another of the same officer in the "Soldier's Pocket Book," that "in a windy country balloons are useless." In the Boer War the usefulness of the balloon was frequently tested, more particularly during the siege of Ladysmith, when it was deemed of great value in directing the fire of the British artillery, and again in Buller's advance, where the balloon is credited with having located a "death-trap" of the enemy at Spion Kop. Other all-important service was rendered at Magersfontein. The Service balloon principally used was made of goldbeaters' skin, containing about 10,000 cubic feet of hydrogen, which had been produced by the action of sulphuric acid on zinc, and compressed in steel cylinders. A special gas factory was, for the purpose of the campaign, established at Cape Town. It is here that reference must be made to some of the special work undertaken by Mr. Eric S. Bruce, which dealt with the management of captive balloons under different conditions, and with a system of signalling thus rendered feasible. Mr. Bruce, who, since Major Baden-Powell's retirement from the office, has devoted his best energies as secretary to the advancement of the British Aeronautical Society, was the inventor of the system of electric balloon signalling which he supplied to the British Government, as well as to the Belgian and Italian Governments. This system requires but a very small balloon, made of three or four thicknesses of goldbeaters' skin, measuring from 7 to 10 feet in diameter, and needing only two or three gas cylinders for inflation. Within the balloon, which is sufficiently translucent, are placed several incandescent lamps in metallic circuit, with a source of electricity on the ground. This source of electricity may consist of batteries of moderate size or a portable hand dynamo. In the circuit is placed an apparatus for making and breaking contact rapidly, and by varying the duration of the flashes in the balloon telegraphic messages may be easily transmitted. To overcome the difficulty of unsteadiness, under circumstances of rough weather, in the captive balloon which carried the glow lamps, Mr. Bruce experimented with guy ropes, and gave a most successful exhibition of their efficiency before military experts at Stamford Bridge grounds, though a stiff wind was blowing at the time. It must be perfectly obvious, however, that a captive balloon in a wind is greatly at a disadvantage, and to counteract this, attempts have been made in the direction of a combination between the balloon and a kite. This endeavour has been attended with some measure of success in the German army. Mr. Douglas Archibald, in England, was one of the first to advocate the kite balloon. In 1888 he called attention to the unsatisfactory behaviour of captive balloons in variable winds, dropping with every gust and rising again with a lull. In proof he described an expedient of Major Templer's, where an attempt was being made to operate a photographic camera hoisted by two tandem kites. "The balloon," he writes, "went up majestically, and all seemed very satisfactory until a mile of cable had been run out, and the winder locked." It was then that troubles began which threatened the wreckage of the apparatus, and Mr. Archibald, in consequence, strongly recommended a kite balloon at that time. Twelve years later the same able experimentalist, impressed with the splendid work done by kites alone for meteorological purposes at least, allowed that he was quite content to "let the kite balloon go by." But the German school of aeronauts were doing bigger things than making trials with kite balloons. The German Society for the Promotion of Aerial Navigation, assisted by the Army Balloon Corps, were busy in 1888, when a series of important ascents were commenced. Under the direction of Dr. Assmann, the energetic president of the aeronautical society above named, captive ascents were arranged in connection with free ascents for meteorological purposes, and it was thus practicable to make simultaneous observations at different levels. These experiments, which were largely taken up on the Continent, led to others of yet higher importance, in which the unmanned balloon took a part. But the Continental annals of this date contain one unhappy record of another nature, the recounting of which will, at least, break the monotony attending mere experimental details. In October, 1893, Captain Charbonnet, an enthusiastic French aeronaut, resolved on spending his honeymoon, with the full consent of his bride, in a prolonged balloon excursion. The start was to be made from Turin, and, the direction of travel lying across the Alps, it was the hope of the voyagers eventually to reach French territory. The ascent was made in perfect safety, as was also the first descent, at the little village of Piobesi, ten miles away. Here a halt was made for the night, and the next morning, when a fresh start was determined on, two young Italians, Signori Botto and Durando, were taken on board as assistants, for the exploit began to assume an appearance of some gravity, and this the more so when storm clouds began brewing. At an altitude of 10,000 feet cross-currents were encountered, and the course becoming obscured the captain descended to near the earth, where he discovered himself to be in dangerous proximity to gaunt mountain peaks. On observing this, he promptly cast out sand so liberally that the balloon rose to a height approaching 20,000 feet, when a rapid descent presently began, and refused to be checked, even with the expenditure of all available ballast. All the while the earth remained obscured, but, anticipating a fall among the mountains, Captain Charbonnet bade his companions lie down in the car while he endeavoured to catch sight of some landmark; but, quite suddenly, the balloon struck some mountain slope with such force as to throw the captain back into the car with a heavy blow over the eye; then, bounding across a gulley, it struck again and yet again, falling and rebounding between rocky walls, till it settled on a steep and snowy ridge. Darkness was now closing in, and the party, without food or proper shelter, had to pass the night as best they might on the bare spot where they fell, hoping for encouragement with the return of day. But dawn showed them to be on a dangerous peak, 10,000 feet high, whence they must descend by their own unassisted efforts. After a little clambering the captain, who was in a very exhausted state, fell through a hidden crevasse, fracturing his skull sixty feet below. The remaining three struggled on throughout the day, and had to pass a second night on the mountain, this time without covering. On the third day they met with a shepherd, who conducted them with difficulty to the little village of Balme. This story, by virtue of its romance, finds a place in these pages; but, save for its tragic ending, it hardly stands alone. Ballooning enterprise and adventure were growing every year more and more common on the Continent. In Scandinavia we find the names of Andree, Fraenkal, and Strindberg; in Denmark that of Captain Rambusch. Berlin and Paris had virtually become the chief centres of the development of ballooning as a science. In the former city a chief among aeronauts had arisen in Dr. A. Berson, who, in December, 1894, not only reached 30,000 feet, ascending alone, but at that height sustained himself sufficiently, by inhaling oxygen, to take systematic observations throughout the entire voyage of five hours. The year before, in company with Lieutenant Gross, he barely escaped with his life, owing to tangled ropes getting foul of the valve. Toulet and those who accompanied him lost their lives near Brussels. Later Wolfert and his engineer were killed near Berlin, while Johannsen and Loyal fell into the Sound. Thus ever fresh and more extended enterprise was embarked upon with good fortune and ill. In fact, it had become evident to all that the Continent afforded facilities for the advancement of aerial exploration which could be met with in no other parts of the world, America only excepted. And it was at this period that the expedient of the ballon sonde, or unmanned balloon, was happily thought of. One of these balloons, the "Cirrus," among several trials, rose to a height, self-registered, of 61,000 feet, while a possible greater height has been accorded to it. On one occasion, ascending from Berlin, it fell in Western Russia, on another in Bosnia. Then, in 1896, at the Meteorological Conference at Paris, with Mascart as President, Gustave Hermite, with characteristic ardour, introduced a scheme of national ascents with balloons manned and unmanned, and this scheme was soon put in effect under a commission of famous names--Andree, Assmann, Berson, Besancon, Cailletet, Erk, de Fonvielle, Hergesell, Hermite, Jaubert, Pomotzew (of St. Petersburg), and Rotch (of Boston, Mass.). In November, 1896, five manned balloons and three unmanned ascended simultaneously from France, Germany, and Russia. The next year saw, with the enterprise of these nations, the co-operation of Austria and Belgium. Messrs. Hermite and Besancon, both French aeronauts, were the first to make practical trial of the method of sounding the upper air by unmanned balloons, and, as a preliminary attempt, dismissed from Paris a number of small balloons, a large proportion of which were recovered, having returned to earth after less than 100 miles' flight. Larger paper balloons were now constructed, capable of carrying simple self-recording instruments, also postcards, which became detached at regular intervals by the burning away of slow match, and thus indicated the path of the balloon. The next attempt was more ambitious, made with a goldbeaters' skin balloon containing 4,000 cubic feet of gas, and carrying automatic instruments of precision. This balloon fell in the Department of the Yonne, and was returned to Paris with the instruments, which remained uninjured, and which indicated that an altitude of 49,000 feet had been reached, and a minimum temperature of -60 degrees encountered. Yet larger balloons of the same nature were then experimented with in Germany, as well as France. A lack of public support has crippled the attempts of experimentalists in this country, but abroad this method of aerial exploration continues to gain favour. Distinct from, and supplementing, the records obtained by free balloons, manned or unmanned, are those to be gathered from an aerostat moored to earth. It is here that the captive balloon has done good service to meteorology, as we have shown, but still more so has the high-flying kite. It must long have been recognised that instruments placed on or near the ground are insufficient for meteorological purposes, and, as far back as 1749, we find Dr. Wilson, of Glasgow, employing kites to determine the upper currents, and to carry thermometers into higher strata of the air. Franklin's kite and its application is matter of history. Many since that period made experiments more or less in earnest to obtain atmospheric observations by means of kites, but probably the first in England, at least to obtain satisfactory results, was Mr. Douglas Archibald, who, during the eighties, was successful in obtaining valuable wind measurements, as also other results, including aerial photographs, at varying altitudes up to 1,000 or 1,200 feet. From that period the records of serious and systematic kite flying must be sought in America. Mr. W. A. Eddy was one of the pioneers, and a very serviceable tailless kite, in which the cross-bar is bowed away from the wind, is his invention, and has been much in use. Mr. Eddy established his kite at Blue Hill--the now famous kite observatory--and succeeded in lifting self-recording meteorological instruments to considerable heights. The superiority of readings thus obtained is obvious from the fact that fresh air-streams are constantly playing on the instruments. A year or two later a totally dissimilar kite was introduced by Mr. Lawrence Hargrave, of Sydney, Australia. This invention, which has proved of the greatest utility and efficiency, would, from its appearance, upset all conventional ideas of what a kite should be, resembling in its simplest form a mere box, minus the back and front. Nevertheless, these kites, in their present form, have carried instruments to heights of upwards of two miles, the restraining line being fine steel piano wire. But another and most efficient kite, admirably adapted for many most important purposes, is that invented by Major Baden-Powell. The main objects originally aimed at in the construction of this kite related to military operations, such as signalling, photography, and the raising of a man to an elevation for observational purposes. In the opinion of the inventor, who is a practiced aeronaut, a wind of over thirty miles an hour renders a captive balloon useless, while a kite under such conditions should be capable of taking its place in the field. Describing his early experiments, Major, then Captain, Baden-Powell, stated that in 1894, after a number of failures, he succeeded with a hexagonal structure of cambric, stretched on a bamboo framework 36 feet high, in lifting a man--not far, but far enough to prove that his theories were right. Later on, substituting a number of small kites for one big one, he was, on several occasions, raised to a height of 100 feet, and had sent up sand bags, weighing 9 stone, to 300 feet, at which height they remained suspended nearly a whole day. This form of kite, which has been further developed, has been used in the South African campaign in connection with wireless telegraphy for the taking of photographs at great heights, notably at Modder River, and for other purposes. It has been claimed that the first well-authenticated occasion of a man being raised by a kite was when at Pirbright Camp a Baden-Powell kite, 30 feet high, flown by two lines, from which a basket was suspended, took a man up to a height of 10 feet. It is only fair, however, to state that it is related that more than fifty years ago a lady was lifted some hundred feet by a great kite constructed by one George Pocock, whose machine was designed for an observatory in war, and also for drawing carriages along highways. CHAPTER XXIV. ANDREE AND HIS VOYAGES Among many suggestions, alike important and original, due to Major Baden-Powell, and coming within the field of aeronautics, is one having reference to the use of balloons for geographical research generally and more particularly for the exploration of Egypt, which, in his opinion, is a country possessing many most desirable qualifications on the score of prevailing winds, of suitable base, and of ground adapted for such steering as may be effected with a trail rope. At the Bristol meeting of the British Association the Major thus propounded his method: "I should suggest several balloons, one of about 60,000 cubic feet, and, say, six smaller ones of about 7,000 cubic feet; then, if one gets torn or damaged, the others might remain intact. After a time, when gas is lost, one of the smaller ones could be emptied into the others, and the exhausted envelope discharged as ballast; the smaller balloons would be easier to transport by porters than one big one, and they could be more easily secured on the earth during contrary winds. Over the main balloon a light awning might be rigged to neutralise, as far as possible, the changes of temperature. A lightning conductor to the top of the balloon might be desirable. A large sail would be arranged, and a bifurcated guide rope attached to the end of a horizontal pole would form an efficient means of steering. The car would be boat-shaped and waterproof, so that it could be used for a return journey down a river. Water tanks would be fitted." The reasonableness of such a scheme is beyond question, even without the working calculations with which it is accompanied; but, ere these words were spoken, one of the most daring explorers that the world has known had begun to put in practice a yet bolder and rasher scheme of his own. The idea of reaching the North Pole by means of balloons appears to have been entertained many years ago. In a curious work, published in Paris in 1863 by Delaville Dedreux, there is a suggestion for reaching the North Pole by an aerostat which should be launched from the nearest accessible point, the calculation being that the distance from such a starting place to the Pole and back again would be only some 1,200 miles, which could be covered in two days, supposing only that there could be found a moderate and favourable wind in each direction. Mr. C. G. Spencer also wrote on the subject, and subsequently Commander Cheyne proposed a method of reaching the Pole by means of triple balloons. A similar scheme was advocated in yet more serious earnest by M. Hermite in the early eighties. Some ten years later than this M. S. A. Andree, having obtained sufficient assistance, took up the idea with the determined intention of pushing it to a practical issue. He had already won his spurs as an aeronaut, as may be briefly told. In October, 1893, when making an ascent for scientific purposes, his balloon got carried out over the Baltic. It may have been the strength of the wind that had taken him by surprise; but, there being now no remedy, it was clearly the speed and persistence of the wind that alone could save him. If a chance vessel could not, or would not, "stand by," he must make the coast of Finland or fall in the sea, and several times the fall in the sea seemed imminent as his balloon commenced dropping. This threatened danger induced him to cast away his anchor, after which the verge of the Finland shore was nearly reached, when a change of wind began to carry him along the rocky coast, just as night was setting in. Recognising his extreme danger, Andree stood on the edge of the car, with a bag of ballast ready for emergencies. He actually passed over an island, on which was a building with a light; but failed to effect a landing, and so fell in the sea on the farther side; but, the balloon presently righting itself, Andree, now greatly exhausted, made his last effort, and as he rose over the next cliff jumped for his life. It was past 7 p.m. when he found himself once again on firm ground, but with a sprained leg and with no one within call. Seeking what shelter he could, he lived out the long night, and, being now scarce able to stand, took off his clothes and waved them for a signal. This signal was not seen, yet shortly a boat put off from an island--the same that he had passed the evening before--and rowed towards him. The boatman overnight had seen a strange sail sweeping over land and sea, and he had come in quest of it, bringing timely succour to the castaway. Briefly stated, Andree's grand scheme was to convey a suitable balloon, with means for inflating it, as also all necessary equipment, as far towards the Pole as a ship could proceed, and thence, waiting for a favourable wind, to sail by sky until the region of the Pole should be crossed, and some inhabited country reached beyond. The balloon was to be kept near the earth, and steered, as far as this might be practicable, by means of a trail rope. The balloon, which had a capacity of nearly 162,000 cubic feet, was made in Paris, and was provided with a rudder sail and an arrangement whereby the hang of the trail rope could be readily shifted to different positions on the ring. Further, to obviate unnecessary diffusion and loss of gas at the mouth, the balloon was fitted with a lower valve, which would only open at a moderate pressure, namely, that of four inches of water. All preparations were completed by the summer of 1896, and on June 7th the party embarked at Gothenburg with all necessaries on board, arriving at Spitzbergen on June 21st. Andree, who was to be accompanied on his aerial voyage by two companions, M. Nils Strindberg and Dr. Ekholm, spent some time in selecting a spot that would seem suitable for their momentous start, and this was finally found on Dane's Island, where their cargo was accordingly landed. The first operation was the erection of a wooden shed, the materials for which they had brought with them, as a protection from the wind. It was a work which entailed some loss of time, after which the gas apparatus had to be got into order, so that, in spite of all efforts, it was the 27th of July before the balloon was inflated and in readiness. A member of an advance party of an eclipse expedition arriving in Spitzbergen at this period, and paying a visit to Andree for the purpose of taking him letters, wrote:--"We watched him deal out the letters to his men. They are all volunteers and include seven sea captains, a lawyer, and other people some forty in all. Andree chaffed each man to whom he gave a letter, and all were as merry as crickets over the business.... We spent our time in watching preparations. The vaseline (for soaking the guide ropes) caught fire to-day, but, luckily no rope was in the pot." But the wind as yet was contrary, and day after day passed without any shift to a favourable quarter, until the captain of the ship which had conveyed them was compelled to bring matters to an issue by saying that they must return home without delay if he was to avoid getting frozen in for the winter. The balloon had now remained inflated for twenty-one days, and Dr. Ekholm, calculating that the leakage of gas amounted to nearly 1 per cent. per day, became distrustful of the capability of such a vessel to cope with such a voyage as had been aimed at. The party had now no choice but to return home with their balloon, leaving, however, the shed and gas-generating apparatus for another occasion. This occasion came the following summer, when the dauntless explorers returned to their task, leaving Gothenburg on May 28th, 1897, in a vessel lent by the King of Sweden, and reaching Dane's Island on the 30th of the same month. Dr. Ekholm had retired from the enterprise, but in his place were two volunteers, Messrs. Frankel and Svedenborg, the latter as "odd man," to fill the place of any of the other three who might be prevented from making the final venture. It was found that the shed had suffered during the winter, and some time was spent in making the repairs and needful preparation, so that the month of June was half over before all was in readiness for the inflation. This operation was then accomplished in four days, and by midnight of June 22nd the balloon was at her moorings, full and in readiness; but, as in the previous year, the wind was contrary, and remained so for nearly three weeks. This, of course, was a less serious matter, inasmuch as the voyagers were a month earlier with their preparation, but so long a delay must needs have told prejudicially against the buoyancy of the balloon, and Andree is hardly to be blamed for having, in the end, committed himself to a wind that was not wholly favourable. The wind, if entirely from the right direction, should have been due south, but on July 11th it had veered to a direction somewhat west of south, and Andree, tolerating no further delay, seized this as his best opportunity, and with a wind "whistling through the woodwork of the shed and flapping the canvas," accompanied by Frankel and Svedenborg, started on his ill-fated voyage. A telegram which Andree wrote for the Press at that epoch ran thus:-- "At this moment, 2.30 p.m., we are ready to start. We shall probably be driven in a north-north-easterly direction." On July 22nd a carrier pigeon was recovered by the fishing boat Alken between North Cape, Spitzbergen, and Seven Islands, bearing a message, "July 13th, 12.30 p.m., 82 degrees 2 minutes north lat., 15 degrees 5 minutes east long. Good journey eastward. All goes well on board. Andree." Not till August 31st was there picked up in the Arctic zone a buoy, which is preserved in the Museum of Stockholm. It bears the message, "Buoy No. 4. First to be thrown out. 11th July, 10 p.m., Greenwich mean time. All well up till now. We are pursuing our course at an altitude of about 250 metres Direction at first northerly 10 degrees east; later; northerly 45 degrees east. Four carrier pigeons were despatched at 5.40 p.m. They flew westwards. We are now above the ice, which is very cut up in all directions. Weather splendid. In excellent spirits.--Andree, Svedenborg, Frankel. (Postscript later on.) Above the clouds, 7.45, Greenwich mean time." According to Reuter, the Anthropological and Geological Society at Stockholm received the following telegram from a ship owner at Mandal:--"Captain Hueland, of the steamship Vaagen who arrived there on Monday morning, reports that when off Kola Fjord, Iceland, in 65 degrees 34 minutes north lat., 21 degrees 28 minutes west long., on May 14th he found a drifting buoy, marked 'No. 7.' Inside the buoy was a capsule marked 'Andree's Polar Expedition,' containing a slip of paper, on which was given the following: 'Drifting Buoy No. 7. This buoy was thrown out from Andree's balloon on July 11th 1897, 10.55 p.m., Greenwich mean time, 82 degrees north lat., 25 degrees east lon. We are at an altitude of 600 metres. All well.--Andree, Svedenborg, Frankel.'" Commenting on the first message, Mr. Percival Spencer says:--"I cannot place reliance upon the accuracy of either the date or else the lat. and long. given, as I am confident that the balloon would have travelled a greater distance in two days." It should be noted that Dane's Island lies in 79 degrees 30 minutes north lat. and 10 degrees 10 minutes east long. Mr. Spencer's opinion, carefully considered and expressed eighteen months afterwards, will be read with real interest:-- "The distance from Dane's Island to the Pole is about 750 miles, and to Alaska on the other side about 1,500 miles. The course of the balloon, however, was not direct to the Pole, but towards Franz Josef Land (about 600 miles) and to the Siberian coast (another 800 miles). Judging from the description of the wind at the start, and comparing it with my own ballooning experience, I estimate its speed as 40 miles per hour, and it will, therefore, be evident that a distance of 2,000 miles would be covered in 50 hours, that is two days and two hours after the start. I regard all theories as to the balloon being capable of remaining in the air for a month as illusory. No free balloon has ever remained aloft for more than 36 hours, but with the favourable conditions at the northern regions (where the sun does not set and where the temperature remains equable) a balloon might remain in the air for double the length of time which I consider ample for the purpose of Polar exploration." A record of the direction of the wind was made after Andree's departure, and proved that there was a fluctuation in direction from S.W. to N.W., indicating that the voyagers may have been borne across towards Siberia. This, however, can be but surmise. All aeronauts of experience know that it is an exceedingly difficult manoeuvre to keep a trail rope dragging on the ground if it is desirable to prevent contact with the earth on the one hand, or on the other to avoid loss of gas. A slight increase of temperature or drying off of condensed moisture may--indeed, is sure to after a while--lift the rope off the ground, in which case the balloon, rising into upper levels, may be borne away on currents which may be of almost any direction, and of which the observer below may know nothing. As to the actual divergence from the wind's direction which a trail rope and side sail might be hoped to effect, it may be confidently stated that, notwithstanding some wonderful accounts that have gone abroad, it must not be relied on as commonly amounting to much more than one or, at the most, two points. Although it is to be feared that trustworthy information as to the ultimate destination of Andree's balloon may never be gained, yet we may safely state that his ever famous, though regrettable, voyage was the longest in duration ever attained. At the end of 48 hours his vessel would seem to have been still well up and going strong. The only other previous voyage that had in duration of travel approached this record was that made by M. Mallet, in 1892, and maintained for 36 hours. Next we may mention that of M. Herve, in 1886, occupying 24 1/2 hours, which feat, however, was almost equal led by the great Leipzig balloon in 1897, which, with eight people in the car, remained up for 24 1/4 hours, and did not touch earth till 1,032 miles had been traversed. The fabric of Andree's balloon may not be considered to have been the best for such an exceptional purpose. Dismissing considerations of cost, goldbeaters' skin would doubtless have been more suitable. The military balloons at Aldershot are made of this, and one such balloon has been known to remain inflated for three months with very little loss. It is conceivable, therefore, that the chances of the voyagers, whose ultimate safety depended so largely upon the staying power of their aerial vessel, might have been considerably increased. One other expedient, wholly impracticable, but often seriously discussed, may be briefly referred to, namely, the idea of taking up apparatus for pumping gas into metal receivers as the voyage proceeds, in order to raise or lower a balloon, and in this way to prolong its life. Mr. Wenham has investigated the point with his usual painstaking care, and reduced its absurdity to a simple calculation, which should serve to banish for good such a mere extravagant theory. Suppose, he says, the gas were compressed to one-twentieth part of its bulk, which would mean a pressure within its receiver of 300 lbs. per square inch, and that each receiver had a capacity of 1 cubic foot, while for safety sake it was made of steel plates one-twentieth of an inch thick, then each receiver would weigh 10 lbs., and to liberate 1,000 feet clearly a weight of 500 lbs. would have to be taken up. Now, when it is considered that 1,000 cubic feet of hydrogen will only lift 72 lbs., the scheme begins to look hope less enough. But when the question of the pumping apparatus, to be worked by hand, is contemplated the difficulties introduced become yet more insuperable. The only feasible suggestion with respect the use of compressed gas is that of taking on board charged cylinders under high pressure, which, after being discharged to supply the leakage of the balloon could, in an uninhabited country, be cast out as ballast last. It will need no pointing out, however, that such an idea would be practically as futile as another which has gravely been recommended, namely, that of heating the gas of the balloon by a Davy lamp, so as to increase its buoyancy at will. Major Baden-Powell has aptly described this as resembling "an attempt to warm a large hall with a small spirit lamp." In any future attempt to reach the Pole by balloon it is not unreasonable to suppose that wireless telegraphy will be put in practice to maintain communication with the base. The writer's personal experience of the possibilities afforded by this mode of communication, yet in its infancy, will be given. CHAPTER XXV. THE MODERN AIRSHIP--IN SEARCH OF THE LEONIDS. In the autumn of 1898 the aeronautical world was interested to hear that a young Brazilian, M. Santos Dumont, had completed a somewhat novel dirigible balloon, cylindrical in shape, with conical ends, 83 feet long by 12 feet in diameter, holding 6,500 cubic feet of gas, and having a small compensating balloon of 880 cubic feet capacity. For a net was substituted a simple contrivance, consisting of two side pockets, running the length of the balloon, and containing battens of wood, to which were affixed the suspension cords, bands being also sewn over the upper part of the balloon connecting the two pockets. The most important novelty, however, was the introduction of a small petroleum motor similar to those used for motor tricycles. The inventor ascended in this balloon, inflated with pure hydrogen, from the Jardin d'Acclimatation, Paris, and circled several times round the large captive balloon in the Gardens, after which, moving towards the Bois de Boulogne, he made several sweeps of 100 yards radius. Then the pump of the compensator caused the engine to stop, and the machine, partially collapsing, fell to the ground. Santos Dumont was somewhat shaken, but announced his intention of making other trials. In this bold and successful attempt there was clear indication of a fresh phase in the construction of the airship, consisting in the happy adoption of the modern type of petroleum motor. Two other hying machines were heard of about this date, one by Professor Giampietre, of Pavia, cigar-shaped, driven by screws, and rigged with masts and sails. The other, which had been constructed and tested in strict privacy, was the invention of a French engineer, M. Ader, and was imagined to imitate the essential structure of a bird. Two steam motors of 20-horse power supplied the power. It was started by being run on the ground on small wheels attached to it, and it was claimed that before a breakdown occurred the machine had actually raised itself into the air. Of Santos Dumont the world was presently to know more, and the same must be said of another inventor, Dr. Barton, of Beckenham, who shortly completed an airship model carrying aeroplanes and operated by clockwork. In an early experiment this model travelled four miles in twenty-three minutes. But another airship, a true leviathan, had been growing into stately and graceful proportions on the shores of the Bodenzee in Wurtemberg, and was already on the eve of completion. Count Zeppelin, a lieut.-general in the German Army, who had seen service in the Franco-German War, had for some years devoted his fortune and energy to the practical study of aerial navigation, and had prosecuted experiments on a large scale. Eventually, having formed a company with a large capital, he was enabled to construct an airship which in size has been compared to a British man-of-war. Cigar-shaped, its length was no less than 420 feet, and diameter 40 feet, while its weight amounted to no more than 7,250 lbs. The framework, which for lightness had been made of aluminium, was, with the object of preventing all the gas collecting at one end of its elongated form, subdivided into seventeen compartments, each of these compartments containing a completely fitted gas balloon, made of oiled cotton and marvellously gas tight. A steering apparatus was placed both fore and aft, and at a safe distance below the main structure were fixed, also forward and aft, on aluminium platforms, two Daimler motor engines of 16-horse power, working aluminium propellers of four blades at the rate of 1,000 revolutions a minute. Finally, firmly attached to the inner framework by rods of aluminium, were two cars of the same metal, furnished with buffer springs to break the force of a fall. The trial trip was not made till the summer following--June, 1900--and, in the meanwhile, experiments had gone forward with another mode of flight, terminating, unhappily, in the death of one of the most expert and ingenious of mechanical aeronauts. Mr. Percy S. Pilcher, now thirty-three years of age, having received his early training in the Navy, retired from the Service to become a civil engineer, and had been for some time a partner in the firm of Wilson and Pilcher. For four or five years he had been experimenting in soaring flight, using a Lilienthal machine, which he improved to suit his own methods. Among these was the device of rising off the ground by being rapidly towed by a line against the wind. At the end of September he gave an exhibition at Stamford Park before Lord Bray and a select party of friends--this in spite of an unsuitable afternoon of unsteady wind and occasional showers. A long towing line was provided, which, being passed round pulley blocks and dragged by a couple of horses, was capable of being hauled in at high speed. The first trial, though ending in an accident, was eminently satisfactory. The apparatus, running against the wind, had risen some distance, when the line broke, yet the inventor descended slowly and safely with outstretched wings. The next trial also commenced well, with an easy rise to a height of some thirty feet. At that point, however, the tail broke with a snap, and the machine, pitching over, fell a complete wreck. Mr. Pilcher was found insensible, with his thigh broken, and though no other serious injury was apparent, he succumbed two days afterwards without recovering consciousness. It was surmised that shrinkage of the canvas of the tail, through getting wet, had strained and broken its bamboo stretcher. This autumn died Gaston Tissandier, at the age of fifty-six; and in the month of December, at a ripe old age, while still in full possession of intellectual vigour, Mr. Coxwell somewhat suddenly passed away. Always keenly interested in the progress of aeronautics; he had but recently, in a letter to the Standard, proposed a well-considered and practical method of employing Montgolfier reconnoitring balloons, portable, readily inflated, and especially suited to the war in South Africa. Perhaps the last letters of a private nature penned by Mr. Coxwell were to the writer and his daughter, full of friendly and valuable suggestion, and more particularly commenting on a recent scientific aerial voyage, which proved to be not only sensational, but established a record in English ballooning. The great train of the November meteors, known as the Leonids, which at regular periods of thirty-three years had in the past encountered the earth's atmosphere, was due, and over-due. The cause of this, and of their finally eluding observation, need only be very briefly touched on here. The actual meteoric train is known to travel in an elongated ellipse, the far end of which lies near the confines of the solar system, while at a point near the hither end the earth's orbit runs slantingly athwart it, forming, as it were, a level crossing common to the two orbits, the earth taking some five or six hours in transit. Calculation shows that the meteor train is to be expected at this crossing every thirty-three and a third years, while the train is extended to such an enormous length--taking more than a year to draw clear--that the earth must needs encounter it ere it gets by, possibly even two years running. There could be no absolute certainty about the exact year, nor the exact night when the earth and the meteors would foregather, owing to the uncertain disturbance which the latter must suffer from the pull of the planetary bodies in the long journey out and home again among them. As is now known, this disturbing effect had actually dispersed the train. The shower, which was well seen in 1866, was pretty confidently expected in 1899, and to guard against the mischance of cloudy weather, it was arranged that the writer should, on behalf of the Times newspaper, make an ascent on the right night to secure observations. Moreover, it was arranged that he should have, as chief assistant, his own daughter, an enthusiastic lady aeronaut, who had also taken part in previous astronomical work. Unfortunately there were two nights, those of November 14th and 15th, when the expected shower seemed equally probable, and, taking counsel with the best authorities in the astronomical world, it seemed that the only course to avoid disappointment would be to have a balloon filled and moored in readiness for an immediate start, either on the first night or on the second. This settled the matter from the astronomical side, but there was the aeronautical side also to be considered. A balloon of 56,000 cubic feet capacity was the largest available for the occasion, and a night ascent with three passengers and instruments would need plenty of lifting power to meet chance emergencies. Thus it seemed that a possible delay of forty-eight hours might entail a greater leakage of gas than could be afforded. The leakage might be expected chiefly to occur at the valve in the head of the balloon, it being extremely difficult to render any form of mechanical valve gas tight, however carefully its joints be stopped with luting. On this account, therefore, it was determined that the balloon should be fitted with what is known as a solid or rending valve, consisting simply of balloon fabric tied hard and fast over the entire upper outlet, after the fashion of a jam pot cover. The outlet itself was a gaping hole of over 2 feet across; but by the time its covering had been carefully varnished over all leakage was sufficiently prevented, the one drawback to this method being the fact that the liberation of gas now admitted of no regulation. Pulling the valve line would simply mean opening the entire wide aperture, which could in no way be closed again. The management of such a valve consists in allowing the balloon to sink spontaneously earthwards, and when it has settled near the ground, having chosen a desirable landing place, to tear open the so-called valve once and for all. This expedient, dictated by necessity, seeming sufficient for the purpose at hand, preparations were proceeded with, and, under the management of Mr. Stanley Spencer, who agreed to act as aeronaut, a large balloon, with solid valve, was brought down to Newbury gas works on November 14th, and, being inflated during the afternoon, was full and made snug by sundown. But as the meteor radiant would not be well above the horizon till after midnight, the aeronautical party retired for refreshment, and subsequently for rest, when, as the night wore on, it became evident that, though the sky remained clear, there would be no meteor display that night. The next day was overcast, and by nightfall hopelessly so, the clouds ever thickening, with absence of wind or any indication which might give promise of a change. Thus by midnight it became impossible to tell whether any display were in progress or not. Under these circumstances, it might have been difficult to decide when to make the start with the best show of reason. Clearly too early a start could not subsequently be rectified; the balloon, once off, could not come back again; while, once liberated, it would be highly unwise for it to remain aloft and hidden by clouds for more than some two hours, lest it should be carried out to sea. Happily the right decision under these circumstances was perfectly clear. Other things being equal, the best time would be about 4 a.m., by which period the moon, then near the full, would be getting low, and the two hours of darkness left would afford the best seeing. Leaving, then, an efficient outlook on the balloon ground, the party enjoyed for some hours the entertainment offered them by the Newbury Guildhall Club, and at 4 a.m. taking their seats in the car, sailed up into the calm chilly air of the November night. But the chilliness did not last for long. A height of 1,500 feet was read by the Davy lamp, and then we entered fog--warm, wetting fog, through which the balloon would make no progress in spite of a prodigal discharge of sand. The fact was that the balloon, which had become chilled through the night hours, was gathering a great weight of moisture from condensation on its surface, and when, at last, the whole depth of the cloud, 1,500 feet, had been penetrated, the chill of the upper air crippled the balloon and sent her plunging down again into the mist, necessitating yet further expenditure of sand, which by this time had amounted to no less than 3 1/2 cwt. in twenty minutes. And then at last we reached our level, a region on the upper margin of the cloud floor, where evaporation reduced the temperature, that had recently been that of greenhouse warmth, to intense cold. That evaporation was going on around us on a gigantic scale was made very manifest. The surface of the vast cloud floor below us was in a perfect turmoil, like that of a troubled sea. If the cloud surface could be compared to anything on earth it most resembled sea where waves are running mountains high. At one moment we should be sailing over a trough, wide and deep below us, the next a mighty billow would toss itself aloft and vanish utterly into space. Everywhere wreaths of mist with ragged fringes were withering away into empty air, and, more remarkable yet, was the conflict of wind which sent the cloud wrack flying simply in all directions. For two hours now there was opportunity for observing at leisure all that could be made of the falling meteors. There were a few, and these, owing to our clear, elevated region, were exceptionally bright. The majority, too, were true Leonids, issuing from the radiant point in the "Sickle," but these were not more numerous than may be counted on that night in any year, and served to emphasise the fact that no real display was in progress. The outlook was maintained, and careful notes made for two hours, at the end of which time the dawn began to break, the stars went in, and we were ready to pack up and come down. But the point was that we were not coming down. We were at that time, 6 a.m., 4,000 feet high, and it needs no pointing out that at such an altitude it would have been madness to tear open our huge rending valve, thus emptying the balloon of gas. It may also be unnecessary to point out that in an ordinary afternoon ascent such a valve would be perfectly satisfactory, for under these circumstances the sun presently must go down, the air must grow chill, and the balloon must come earthward, allowing of an easy descent until a safe and suitable opportunity for rending the valve occurred; but now we knew that conditions were reversed, and that the sun was just going to rise. And then it was we realised that we were caught in a trap. From that moment it was painfully evident that we were powerless to act, and were at the mercy of circumstances. By this time the light was strong, and, being well above the tossing billows of mist, we commanded an extended view on every side, which revealed, however, only the upper unbroken surface of the dense cloud canopy that lay over all the British Isles. We could only make a rough guess as to our probable locality. We knew that our course at starting lay towards the west, and if we were maintaining that course a travel of scarcely more than sixty miles would carry us out to the open sea. We had already been aloft for two hours, and as we were at an altitude at which fast upper currents are commonly met with, it was high time that, for safety, we should be coming down; yet it was morally certain that it would be now many hours before our balloon would commence to descend of its own accord by sheer slow leakage of gas, by which time, beyond all reasonable doubt, we must be carried far out over the Atlantic. All we could do was to listen intently for any sounds that might reach us from earth, and assure us that we were still over the land; and for a length of time such sounds were vouchsafed us--the bark of a dog, the lowing of cattle, the ringing trot of a horse on some hard road far down. And then, as we were expecting, the sun climbed up into an unsullied sky, and, mounting by leaps and bounds, we watched the cloud floor receding beneath us. The effect was extremely beautiful. A description written to the Times the next morning, while the impression was still fresh, and from notes made at this period, ran thus:--"Away to an infinitely distant horizon stretched rolling billows of snowy whiteness, broken up here and there into seeming icefields, with huge fantastic hummocks. Elsewhere domes and spires reared themselves above the general surface, or an isolated Matterhorn towered into space. In some quarters it was impossible to look without the conviction that we actually beheld the outline of lofty cliffs overhanging a none too distant sea." Shortly we began to hear loud reports overhead, resembling small explosions, and we knew what these were--the moist, shrunken netting was giving out under the hot sun and yielding now and again with sudden release to the rapidly expanding gas. It was, therefore, with grave concern, but with no surprise, that when we next turned to the aneroid we found the index pointing to 9,000 feet, and still moving upwards. Hour after hour passed by, and, sounds having ceased to reach us, it remains uncertain whether or no we were actually carried out to sea and headed back again by contrary currents, an experience with which aeronauts, including the writer, have been familiar; but, at length, there was borne up to us the distant sound of heavy hammers and of frequent trains, from which we gathered that we were probably over Bristol, and it was then that the thought occurred to my daughter that we might possibly communicate with those below with a view to succour. This led to our writing the following message many times over on blank telegraph forms and casting them down:--"Urgent. Large balloon from Newbury travelling overhead above the clouds. Cannot descend. Telegraph to sea coast (coast-guards) to be ready to rescue.--Bacon and Spencer." While thus occupied we caught the sound of waves, and the shriek of a ship's siren. We were crossing a reach of the Severn, and most of our missives probably fell in the sea. But over the estuary there must have been a cold upper current blowing, which crippled our balloon, for the aneroid presently told of a fall of 2,000 feet. It was now past noon, and to us the turn of the tide was come. Very slowly, and with strange fluctuations, the balloon crept down till it reached and became enveloped in the cloud below, and then the end was near. The actual descent occupied nearly two hours, and affords a curious study in aerostation. The details of the balloon's dying struggles and of our own rough descent, entailing the fracture of my daughter's arm, are told in another volume.{*} We fell near Neath, Glamorganshire, only one and a half miles short of the sea, completing a voyage which is a record in English ballooning--ten hours from start to finish. * "By Land and Sky," by the Author. CHAPTER XXVI. RECENT AERONAUTICAL EVENTS. The first trial of the Zeppelin air ship was arranged to take place on June 30th, 1900, a day which, from absence of wind, was eminently well suited for the purpose; but the inflation proved too slow a process, and operations were postponed to the morrow. The morrow, however, was somewhat windy, causing delay, and by the time all was in readiness darkness had set in and the start was once more postponed. On the evening of the third day the monster craft was skilfully and successfully manoeuvred, and, rising with a very light wind, got fairly away, carrying Count Zeppelin and four other persons in the two cars. Drifting with the wind, it attained a height of some 800 or 900 feet, at which point the steering apparatus being brought into play it circled round and faced the wind, when it remained stationary. But not for long. Shortly it began to descend and, sinking gradually, gracefully, and in perfect safety, in about nine minutes it reached and rested on the water, when it was towed home. A little later in the month, July, another trial was made, when a wind was blowing estimated at sixteen miles an hour. As on the previous occasion, the direct influence of the sun was avoided by waiting till evening hours. It ascended at 8 p.m., and the engines getting to work it made a slow progress of about two miles an hour against the wind for about 3 1/2 miles, when one of the rudders gave way, and the machine was obliged to descend. On the evening of October 24th of the same year, in very calm weather and with better hope, another ascent was made. On this occasion, however, success was frustrated by one of the rear rudders getting foul of the gear, followed by the escape of gas from one of the balloons. Another and more successful trial took place in the same month, again in calm atmosphere. Inferior gas was employed, and it would appear that the vessel had not sufficient buoyancy. It remained aloft for a period of twenty minutes, during which it proved perfectly manageable, making a graceful journey out and home, and returning close to its point of departure. This magnificent air ship, the result of twenty years of experiment, has since been abandoned and broken up; yet the sacrifice has not been without result. Over and above the stimulus which Count Zeppelin's great endeavour has given to the aeronautical world, two special triumphs are his. He has shown balloonists how to make a perfectly gas-tight material, and has raised powerful petroleum motors in a balloon with safety. In the early part of 1900 it was announced that a member of the Paris Aero Club, who at the time withheld his name (M. Deutsch) offered a prize of 100,000 francs to the aeronaut who, either in a balloon or flying machine, starting from the grounds of the Aero Club at Longchamps, would make a journey round the Eiffel Tower, returning to the starting place within half an hour. The donor would withdraw his prize if not won within five years, and in the meanwhile would pay 4,000 francs annually towards the encouragement of worthy experimenters. It was from this time that flying machines in great variety and goodly number began to be heard of, if not actually seen. One of the earliest to be announced in the Press was a machine invented by the Russian, Feedoroff, and the Frenchman, Dupont. Dr. Danilewsky came forward with a flying machine combining balloon and aeroplane, the steering of which would be worked like a velocipede by the feet of the aeronaut. Mr. P. Y. Alexander, of Bath, who had long been an enthusiastic balloonist, and who had devoted a vast amount of pains, originality, and engineering skill to the pursuit of aeronautics, was at this time giving much attention to the flying machine, and was, indeed, one of the assistants in the first successful launching of the Zeppelin airship. In concert with Mr. W. G. Walker, A.M.I.C.E., Mr. Alexander carried out some valuable and exhaustive experiments on the lifting power of air propellers, 30 feet in diameter, driven by a portable engine. The results, which were of a purely technical nature, have been embodied in a carefully compiled memoir. An air ship now appeared, invented by M. Rose, consisting of two elongated vessels filled with gas, and carrying the working gear and car between them. The machine was intentionally made heavier than air, and was operated by a petrol motor of 12-horse power. It was now that announcements began to be made to the effect that, next to the Zeppelin air ship, M. Santos Dumont's balloon was probably attracting most of the attention of experts. The account given of this air vessel by the Daily Express was somewhat startling. The balloon proper was compared to a large torpedo. Three feet beneath this hangs the gasoline motor which is to supply the power. The propeller is 12 feet in diameter, and is revolved so rapidly by the motor that the engine frequently gets red hot. The only accommodation for the traveller is a little bicycle seat, from which the aeronaut will direct his motor and steering gear by means of treadles. Then the inclination or declination of his machine must be noted on the spirit level at his side, and the 200 odd pounds of ballast must be regulated as the course requires. A more detailed account of this navigable balloon was furnished by a member of the Paris Aero Club. From this authority we learn that the capacity of the balloon was 10,700 cubic feet. It contained an inner balloon and an air fan, the function of which was to maintain the shape of the balloon when meeting the wind, and the whole was operated by a 10-horse power motor capable of working the screw at 100 revolutions per minute. But before the aerial exploits of Santos Dumont had become famous, balloons had again claimed public attention. On August 1st Captain Spelterini, with two companions, taking a balloon and 180 cylinders of hydrogen to the top of the Rigi and ascending thence, pursued a north-east course, across extensive and beautiful tracts of icefield and mountain fastnesses unvisited by men. The descent, which was difficult and critical, was happily manoeuvred. This took place on the Gnuetseven, a peak over 5,000 feet high, the plateau on which the voyagers landed being described as only 50 yards square, surrounded by precipices. On the 10th of September following the writer was fortunate in carrying out some wireless telegraphy experiments in a balloon, the success of which is entirely due to the unrivalled skill of Mr. Nevil Maskelyne, F.R.A.S., and to his clever adaptation of the special apparatus of his own invention to the exigencies of a free balloon. The occasion was the garden party at the Bradford meeting of the British Association, Admiral Sir Edmund Fremantle taking part in the voyage, with Mr. Percival Spencer in charge. The experiment was to include the firing of a mine in the grounds two minutes after the balloon had left, and this item was entirely successful. The main idea was to attempt to establish communication between a base and a free balloon retreating through space at a height beyond practicable gun shot. The wind was fast and squally, and the unavoidable rough jolting which the car received at the start put the transmitting instrument out of action. The messages, however, which were sent from the grounds at Lister Park were received and watched by the occupants of the car up to a distance of twenty miles, at which point the voyage terminated. On September 30th, and also on October 9th, of this year, took place two principal balloon races from Vincennes in connection with the Paris Exposition. In the first race, among those who competed were M. Jacques Faure, the Count de la Vaulx, and M. Jacques Balsan. The Count was the winner, reaching Wocawek, in Russian Poland, a travel of 706 miles, in 21 hours 34 minutes. M. Balsan was second, descending near Dantzig in East Prussia, 757 miles, in 22 hours. M. Jacques Faure reached Mamlitz, in East Prussia, a distance of 753 miles. In the final race the Count de la Vaulx made a record voyage of 1,193 miles, reaching Korosticheff, in Russia, in 35 hours 45 minutes, attaining a maximum altitude of 18,810 feet. M. J. Balsan reached a greater height, namely, 21,582 feet, travelling to Rodom, in Russia, a distance of 843 miles, in 27 hours 25 minutes. Some phenomenal altitudes were attained at this time. In September, 1898, Dr. Berson, of Berlin, ascended from the Crystal Palace in a balloon inflated with hydrogen, under the management of Mr. Stanley Spencer, oxygen being an essential part of the equipment. The start was made at 5 p.m., and the balloon at first drifted south-east, out over the mouth of the Thames, until at an altitude of 10,000 feet an upper current changed the course to southwest, the balloon mounting rapidly till 23,000 feet was reached, at which height the coast of France was plainly seen. At 25,000 feet both voyagers were gasping, and compelled to inhale oxygen. At 27,500 feet, only four bags of ballast being left, the descent was commenced, and a safe landing was effected at Romford. Subsequently Dr. Berson, in company with Dr. Suring, ascending from Berlin, attained an altitude of 34,000 feet. At 30,000 feet the aeronauts were inhaling oxygen, and before reaching their highest point both had for a considerable time remained unconscious. In 1901 a new aeroplane flying machine began to attract attention, the invention of Herr Kress. A novel feature of the machine was a device to render it of avail for Arctic travel. In shape it might be compared to an iceboat with two keels and a long stem, the keels being adapted to run on ice or snow, while the boat would float on water. Power was to be derived from a petrol motor. At the same period M. Henry Sutor was busy on Lake Constance with an air ship designed also to float on water. Then Mr. Buchanan followed with a fish-shaped vessel, one of the most important specialities of which consisted in side propellers, the surfaces of which were roughened with minute diagonal grooves to effect a greater grip on the air. No less original was the air ship, 100 feet long, and carrying 18,000 cubic feet of gas, which Mr. W. Beedle was engaged upon. In this machine, besides the propellers for controlling the horizontal motion, there was one to regulate vertical motion, with a view of obviating expenditure of gas or ballast. But by this time M. Santos Dumont, pursuing his hobby with unparalleled perseverance, had built in succession no less than six air ships, meeting with no mean success, profiting by every lesson taught by failures, and making light of all accidents, great or small. On July 15th, 1901, he made a famous try for the Deutsch prize in a cigar-shaped balloon, 110 feet long, 19,000 cubic feet capacity, carrying a Daimler oil motor of 15-horse power. The day was not favourable, but, starting from the Parc d'Aerostation, he was abreast of the Eiffel Tower in thirteen minutes, circling round which, and battling against a head wind, he reached the grounds of the Aero Club in 41 minutes from the start, or 11 minutes late by the conditions of the prize. A cylinder had broken down, and the balance of the vessel had become upset. Within a fortnight--July 29th--in favourable weather, he made another flight, lasting fifteen minutes, at the end of which he had returned to his starting ground. Then on August 8th a more momentous attempt came off. Sailing up with a rapid ascent, and flying with the wind, Santos Dumont covered the distance to the Tower in five minutes only, and gracefully swung round; but, immediately after, the wind played havoc, slowing down the motor, at the same time damaging the balloon, and causing an escape of gas. On this Santos Dumont, ascending higher into the sky, quitted the car, and climbed along the keel to inspect, and, if possible, rectify the motor, but with little success. The balloon was emptying, and the machine pitched badly, till a further rent occurred, when it commenced falling hopelessly and with a speed momentarily increasing. Slanting over a roof, the balloon caught a chimney and tore asunder; but the wreck, also catching, held fast, while the car hung helplessly down a blank wall. In this perilous predicament great coolness and agility alone averted disaster, till firemen were able to come to the rescue. The air ship was damaged beyond repair, but by September 6th another was completed, and on trial appeared to work well until, while travelling at speed, it was brought up and badly strained by the trail rope catching in trees. Early in the next month the young Brazilian was aloft again, with weather conditions entirely in his favour; but again certain minor mishaps prevented his next struggle for the prize, which did not take place till the 19th. On this day a light cross wind was blowing, not sufficient, however, seriously to influence the first stage of the time race, and the outward journey was accomplished with a direct flight in nine minutes. On rounding the tower, however, the wind began to tell prejudicially, and the propeller became deranged. On this, letting his vessel fall off from the wind, Santos Dumont crawled along the framework till he reached the motor, which he succeeded in again setting in working order, though not without a delay of several minutes and some loss of ground. From that point the return journey was accomplished in eight minutes, and the race was, at the time, declared lost by 40 seconds only. The most important and novel feature in the air ships constructed by Santos Dumont was the internal ballonet, inflated automatically by a ventilator, the expedient being designed to preserve the shape of the main balloon itself while meeting the wind. On the whole, it answered well, and took the place of the heavy wire cage used by Zeppelin. M. de Fonvielle, commenting on the achievements of Santos Dumont, wrote:--"It does not appear that he has navigated his balloon against more than very light winds, but in his machinery he has shown such attention to detail that it may reasonably be expected that if he continues to increase his motive power he will, ere long, exceed past performances." Mr. Chanute has a further word to say about the possibility of making balloons navigable. He considers that their size will have to be great to the verge of impracticability and the power of the motor enormous in proportion to its weight. As to flying machines, properly so called, he calculates the best that has been done to be the sustaining of from 27 lbs. to 55 lbs. per horse power by impact upon the air. But Mr. Chanute also argues that the equilibrium is of prime importance, and on this point there could scarcely be a greater authority. No one of living men has given more attention to the problem of "soaring," and it is stated that he has had about a thousand "slides" made by assistants, with different types of machine, and all without the slightest accident. Many other aerial vessels might be mentioned. Mr. T. H. Bastin, of Clapham, has been engaged for many years on a machine which should imitate bird flight as nearly as this may be practicable. Baron Bradsky aims at a navigable balloon on an ambitious scale. M. Tatin is another candidate for the Deutsch prize. Of Dr. Barton's air ship more is looked for, as being designed for the War Office. It is understood that the official requirements demand a machine which, while capable of transporting a man through the air at a speed of 13 miles an hour, can remain fully inflated for 48 hours. One of the most sanguine, as well as enterprising, imitators of Santos Dumont was a fellow countryman, Auguste Severo. Of his machine during construction little could be gathered, and still less seen, from the fact that the various parts were being manufactured at different workshops, but it was known to be of large size and to be fitted with powerful motors. This was an ill-fated vessel. At an early hour on May 12th of this year, 1902, all Paris was startled by a report that M. Severo and his assistant, M. Sachet had been killed while making a trial excursion. It appears that at daybreak it had been decided that the favourable moment for trial had arrived. The machinery was got ready, and with little delay the air vessel was dismissed and rose quietly and steadily into the calm sky. The Daily Mail gives the following account of what ensued:-- "For the first few minutes all went well, and the motor seemed to be working satisfactorily. The air ship answered the helm readily, and admiring exclamations rose from the crowd.... But as the vessel rose higher she was seen to fall off from the wind, while the aeronauts could be seen vainly endeavouring to keep her head on. Then M. Severo commenced throwing out ballast.... All this time the ship was gradually soaring higher and higher until, just as it was over the Montparnasse Cemetery, at the height of 2,000 feet, a sheet of flame was seen to shoot up from one of the motors, and instantly the immense silk envelope containing 9,000 cubic feet of hydrogen was enveloped in leaping tongues of fire.... As soon as the flames came in contact with the gas a tremendous explosion followed, and in an instant all that was left of the air ship fell to the earth." Both aeronauts were dashed to pieces. It was thought that the fatality was caused through faulty construction, the escape valve for the gas being situated only about nine feet from the motor. It was announced by Count de la Vaulx that during the summer of 1901 he would attempt to cross the Mediterranean by a balloon, provisioned for three weeks, maintaining communication with the coast during his voyage by wireless telegraphy and other methods of signalling. He was to make use of the "Herve Deviator," or steering apparatus, which may be described as a series of cupshaped plates dipping in the water at the end of a trail rope. By means of controlling cords worked from the car, the whole series of plates could be turned at an angle to the direction of the wind, by which the balloon's course would be altered. Count de la Vaulx attempted this grand journey on October 12th, starting from Toulon with the intention of reaching Algiers, taking the precaution, however, of having a cruiser in attendance. When fifty miles out from Marseilles a passing steamer received from the balloon the signal, "All's well"; but the wind had veered round to the east, and, remaining persistently in this quarter, the Count abandoned his venture, and, signalling to the cruiser, succeeded in alighting on her deck, not, however, before he had completed the splendid and record voyage of 41 hours' duration. CHAPTER XXVII. THE POSSIBILITIES OF BALLOONS IN WARFARE. Clearly the time has not yet arrived when the flying machine will be serviceable in war. Yet we are not without those theorisers who, at the present moment, would seriously propose schemes for conveying dynamite and other explosives by air ship, or dropping them over hostile forces or fortresses, or even fleets at sea. They go yet further, and gravely discuss the point whether such warfare would be legitimate. We, however, may say at once, emphatically, that any such scheme is simply impracticable. It must be abundantly evident that, so far, no form of dirigible air ship exists which could be relied on to carry out any required manoeuvre in such atmospheric conditions as generally prevail. If, even in calm and favourable weather, more often than not motors break down, or gear carries away, what hope is there for any aerial craft which would attempt to battle with such wind currents as commonly blow aloft? And when we turn to the balloon proper, are chances greatly improved? The eminently practical aeronaut, John Wise, as was told in Chapter XII., prepared a scheme for the reduction of Vera Cruz by the agency of a balloon. Let us glance at it. A single balloon was to suffice, measuring 100 feet in diameter, and capable of raising in the gross 30,000 lbs. To manoeuvre this monstrous engine he calculates he would require a cable five miles long, by means of which he hoped, in some manner, to work his way directly over the fortress, and to remain poised at that point at the height of a mile in the sky. Once granted that he could arrive and maintain himself at that position, the throwing out of combustibles would be simple, though even then the spot where they would alight after the drop of a mile would be by no means certain. It is also obvious that a vast amount of gas would have to be sacrificed to compensate for the prodigal discharge of ballast in the form of missiles. The idea of manoeuvring a balloon in a wind, and poising it in the manner suggested, is, of course, preposterous; and when one considers the attempt to aim bombs from a moving balloon high in air the case becomes yet more absurd. Any such missile would partake of the motion of the balloon itself, and it would be impossible to tell where it would strike the earth. To give an example which is often enough tried in balloon travel when the ground below is clear. A glass bottle (presumably empty) is cast overboard and its fall watched. It is seen not to be left behind, but to keep pace with the balloon, shrinking gradually to an object too small to be discerned, except when every now and then a ray of sunlight reflected off it reveals it for a moment as it continues to plunge downwards. After a very few seconds the impression is that it is about to reach the earth, and the eye forms a guess at some spot which it will strike; but the spot is quickly passed, and the bottle travels far beyond across a field, over the further fence, and vastly further yet; indeed, inasmuch as to fall a mile in air a heavy body may take over twenty seconds--and twenty seconds is long to those who watch--it is often impossible to tell to two or three fields where it will finally settle. All this while the risk that a balloon would run of being riddled by bullets, shrapnel, or pom-poms has not been taken into account, and as to the estimate of this risk there is some difference of opinion. The balloon corps and the artillery apparently approach the question with different bias. On the one hand, it is stated with perfect truth that a free balloon, which is generally either rising or falling, as well as moving across country, is a hard object to hit, and a marksman would only strike it with a chance or blundering shot; but, on the other hand let us take the following report of three years ago. The German artillery had been testing the efficiency of a quick-firing gun when used against a balloon, and they decided that the latter would have no chance of escape except at night. A German kite-balloon was kept moving at an altitude of 600 metres, and the guns trained upon it were distant 3,000 metres. It was then stated that after the third discharge of the rapid firing battery the range was found, when all was at once over with the balloon; for, not only was it hit with every discharge, but it was presently set on fire and annihilated. But, in any case, the antique mode of keeping a balloon moored at any spot as a post of observation must be abandoned in modern warfare. Major Baden-Powell, speaking from personal experience in South Africa, has shown how dangerous, or else how useless, such a form of reconnaissance has become. "I remember," he says, "at the battle of Magersfontein my company was lying down in extended order towards the left of our line. We were perfectly safe from musketry fire, as we lay, perhaps, two miles from the Boer trenches, which were being shelled by some of our guns close by. The enemy's artillery was practically silent. Presently, on looking round, I descried our balloon away out behind us about two miles off. Then she steadily rose and made several trips to a good height, but what could be seen from that distance? When a large number of our troops were ranged up within 800 yards of the trenches, and many more at all points behind them, what useful information could be obtained by means of the balloon four miles off?" The same eminent authority insists on the necessity of an observing war balloon making short ascents. The balloon, in his opinion, should be allowed to ascend rapidly to its full height, and with as little delay as possible be hauled down again. Under these conditions it may then be well worth testing whether the primitive form of balloon, the Montgolfier, might not be the most valuable. Instead of being made, as the war balloon is now, of fragile material, and filled with costly gas difficult to procure, and which has to be conveyed in heavy and cumbersome cylinders, a hot air balloon could be rapidly carried by hand anywhere where a few men could push their way. It is of strong material, readily mended if torn, and could be inflated for short ascents, if not by mere brush wood, then by a portable blast furnace and petroleum. But there is a further use for balloons in warfare not yet exploited. The Siege of Paris showed the utility of free balloons, and occasions arise when their use might be still further extended. The writer pointed out that it might have been very possible for an aeronaut of experience, by choosing the right weather and the right position along the British lines, to have skilfully manoeuvred a free balloon by means of upper currents, so as to convey all-important intelligence to besieged Mafeking, and he proved that it would have sufficed if the balloon could have been "tacked" across the sky to within some fifteen miles of the desired goal. The mode of signalling which he proposed was by means of a "collapsing drum," an instrument of occasional use in the Navy. A modification of this instrument, as employed by the writer, consisted of a light, spherical, drum-shaped frame of large size, which, when covered with dark material and hung in the clear below the car of a lofty balloon, could be well seen either against blue sky or grey at a great distance. The so-called drum could, by a very simple contrivance, readily worked from the car, be made to collapse into a very inconspicuous object, and thus be capable of displaying Morse Code signals. A long pause with the drum extended--like the long wave of a signalling flag--would denote a "dash," and a short pause a "dot," and these motions would be at once intelligible to anyone acquainted with the now universal Morse Code system. Provided with an apparatus of the kind, the writer made an ascent from Newbury at a time when the military camps were lying on Salisbury Plain at a distance of nearly twenty miles to the south-west. The ground wind up to 2,500 feet on starting was nearly due north, and would have defeated the attempt; again, the air stream blowing above that height was nearly due east, which again would have proved unsuitable. But it was manifestly possible to utilise the two currents, and with good luck to zig-zag one's course so as to come within easy signalling distance of the various camps; and, as a matter of fact, we actually passed immediately over Bulford Camp, with which we exchanged signals, while two other camps lay close to right and left of us. Fortune favouring us, we had actually hit our mark, though it would have been sufficient for the experiment had our course lain within ten miles right or left. Yet a further use for the balloon in warfare remains untried in this country. Acting under the advice of experts in the Service, the writer, in the early part of the present year, suggested to the Admiralty the desirability of experimenting with balloons as a means of detecting submarine engines of war. It is well known that reefs and shoals can generally be seen from a cliff or mast head far more clearly than from the deck or other position near the surface of the water. Would not, then, a balloon, if skilfully manoeuvred, serve as a valuable post of observation? The Admiralty, in acknowledging the communication, promised to give the matter their attention; but by the month of June the Press had announcements of how the self-same experiments had been successfully carried through by French authorities, while a few days later the Admiralty wrote, "For the present no need is seen for the use of a captive balloon to detect submarines." Among many and varied ballooning incidents which have occurred to the writer, there are some which may not unprofitably be compared with certain experiences already recorded of other aeronauts. Thunderstorms, as witnessed from a balloon, have already been casually described, and it may reasonably be hoped that the observations which have, under varying circumstances, been made at high altitudes may throw some additional light on this familiar, though somewhat perplexing, phenomenon. To begin with, it seems a moot point whether a balloon caught in a thunderstorm is, or is not, in any special danger of being struck. It has been argued that immunity under such circumstances must depend upon whether a sufficiently long time has elapsed since the balloon left the earth to allow of its becoming positively electrified by induction from the clouds or by rain falling upon its surface. But there are many other points to be considered. There is the constant escape of gas from the mouth; there is the mass of pointed metal in the anchor; and, again, it is conceivable that a balloon rapidly descending out of a thunderstorm might carry with it a charge residing on its moistened surface which might manifest itself disastrously as the balloon reached the earth. Instances seem to have been not infrequent of balloons encountering thunderstorms; but, unfortunately, in most cases the observers have not had any scientific training, or the accounts which are to hand are those of the type of journalist who is chiefly in quest of sensational copy. Thus there is an account from America of a Professor King who made an ascent from Burlington, Iowa, just as a thunderstorm was approaching, with the result that, instead of scudding away with the wind before the storm, he was actually, as if by some attraction, drawn into it. On this his aim was to pierce through the cloud above, and then follows a description which it is hard to realise:--"There came down in front of him, and apparently not more than 50 feet distant, a grand discharge of electricity." Then he feels the car lifted, the gas suddenly expands to overflowing, and the balloon is hurled through the cloud with inconceivable velocity, this happening several times, with tremendous oscillations of the car, until the balloon is borne to earth in a torrent of rain. We fancy that many practical balloonists will hardly endorse this description. But we have another, relating to one of the most distinguished aeronauts, M. Eugene Godard, who, in an ascent with local journalists, was caught in a thunderstorm. Here we are told--presumably by the journalists--that "twice the lightning flashed within a few yards of the terror-stricken crew." Once again, in an ascent at Derby, a spectator writes:--"The lightning played upon the sphere of the balloon, lighting it up and making things visible through it." This, however, one must suppose, can hardly apply to the balloon when liberated. But a graphic description of a very different character given in the "Quarterly Journal of the Royal Meteorological Society" for January, 1901, is of real value. It appears that three lieutenants of the Prussian Balloon Corps took charge of a balloon that ascended at Berlin, and, when at a height of 2,300 feet, became enveloped in the mist, through which only occasional glimpses of earth were seen. At this point a sharp, crackling sound was heard at the ring, like the sparking of a huge electrical machine, and, looking up, the voyagers beheld sparks apparently some half-inch thick, and over two feet in length, playing from the ring. Thunder was heard, but--and this may have significance--only before and after the above phenomenon. Another instructive experience is recorded of the younger Green in an ascent which he made from Frankfort-on-the-Maine. On this occasion he relates that he encountered a thunderstorm, and at a height of 4,400 feet found himself at the level where the storm clouds were discharging themselves in a deluge. He seems to have had no difficulty in ascending through the storm into the clear sky above, where a breeze from another quarter quickly carried him away from the storm centre. This co-existence, or conflict of opposite currents, is held to be the common characteristic, if not the main cause, of thunderstorms, and tallies with the following personal experience. It was in typical July weather of 1900 that the writer and his son, accompanied by Admiral Sir Edmund Fremantle and Mr. Percival Spencer, made an evening ascent from Newbury. It had been a day of storms, but about 5 p.m., after what appeared to be a clearing shower, the sky brightened, and we sailed up into a cloudless heaven. The wind, at 3,000 feet, was travelling at some thirty miles an hour, and ere the distance of ten miles had been covered a formidable thunder pack was seen approaching and coming up dead against the wind. Nothing could be more evident than that the balloon was travelling rapidly with a lower wind, while the storm was being borne equally rapidly on an upper and diametrically opposite current. It proved one of the most severe thunderstorms remembered in the country. It brooded for five hours over Devizes, a few miles ahead. A homestead on our right was struck and burned to the ground, while on our left two soldiers were killed on Salisbury Plain. The sky immediately overhead was, of course, hidden by the large globe of the balloon, but around and beneath us the storm seemed to gather in a blue grey mist, which quickly broadened and deepened till, almost before we could realise it, we found ourselves in the very heart of the storm, the lightning playing all around us, and the sharp hail stinging our faces. The countrymen below described the balloon as apparently enveloped by the lightning, but with ourselves, though the flashes were incessant, and on all sides, the reverberations of the thunder were not remarkable, being rather brief explosions in which they resembled the thunder claps not infrequently described by travellers on mountain heights. The balloon was now descending from a double cause: the weight of moisture suddenly accumulated on its surface, and the very obvious downrush of cold air that accompanied the storm of pelting hail. With a very limited store of ballast, it seemed impossible to make a further ascent, nor was this desirable. The signalling experiments on which we were intent could not be carried on in such weather. The only course was to descend, and though this was not at once practicable, owing to Savernake Forest being beneath us, we effected a safe landing in the first available clearing. As has been mentioned, Mr. Glaisher and other observers have recorded several remarkable instances of opposite wind currents being met with at moderate altitudes. None, however, can have been more noteworthy or surprising than the following experience Of the writer on Whit Monday of 1899. The ascent was under an overcast sky, from the Crystal Palace at 3 p.m., at which hour a cold drizzle was settling in with a moderate breeze from the east. Thus, starting from the usual filling ground near the north tower, the balloon sailed over the body of the Palace, and thence over the suburbs towards the west till lost in the mist. We then ascended through 1,500 feet of dense, wetting cloud, and, emerging in bright sunshine, continued to drift for two hours at an average altitude of some 3,000 feet; 1,000 feet below us was the ill-defined, ever changing upper surface of the dense cloud floor, and it was no longer possible to determine our course, which we therefore assumed to have remained unchanged. At length, however, as a measure of prudence, we determined to descend through the clouds sufficiently to learn something of our whereabouts, which we reasonably expected to be somewhere in Surrey or Berks. On emerging, however, below the cloud, the first object that loomed out of the mist immediately below us was a cargo vessel, in the rigging of which our trail rope was entangling itself. Only by degrees the fact dawned upon us that we were in the estuary of the Thames, and beating up towards London once again with an cast wind. Thus it became evident that at the higher level, unknown to ourselves, we had been headed back on our course, for two hours, by a wind diametrically opposed to that blowing on the ground. Two recent developments of the hot-air war balloon suggest great possibilities in the near future. One takes the form of a small captive, carrying aloft a photographic camera directed and operated electrically from the ground. The other is a self-contained passenger balloon of large dimensions, carrying in complete safety a special petroleum burner of great power. These new and important departures are mainly due to the mechanical genius of Mr. J. N. Maskelyne, who has patented and perfected them in conjunction with the writer. CHAPTER XXVIII. THE CONSTITUTION OF THE AIR. Some fair idea of the conditions prevailing in the upper air may have been gathered from the many and various observations already recorded. Stating the case broadly, we may assert that the same atmospheric changes with which we are familiar at the level of the earth are to be found also at all accessible heights, equally extensive and equally sudden. Standing on an open heath on a gusty day, we may often note the rhythmic buffeting of the wind, resembling the assault of rolling billows of air. The evidence of these billows has been actually traced far aloft in balloon travel, when aeronauts, looking down on a wind-swept surface of cloud, have observed this surface to be thrown into a series of rolls of vapour, which were but vast and veritable waves of air. The interval between successive crests of these waves has on one occasion been estimated at approximately half a mile. We have seen how these air streams sometimes hold wide and independent sway at different levels. We have seen, too, how they sometimes meet and mingle, not infrequently attended with electrical disturbance Through broad drifts of air minor air streams would seem often literally to "thread" their way, breaking up into filaments or wandering rills of air. In the voyage across Salisbury Plain lately described, while the balloon was being carried with the more sluggish current, a number of small parachutes were dropped out at frequent intervals and carefully watched. These would commonly attend the balloon for a little while, until, getting into some minor air stream, they would suddenly and rapidly diverge at such wide angles as to suggest that crossing our actual course there were side paths, down which the smaller bodies became wafted. On another occasion the writer met with strongly marked and altogether exceptional evidence of the vehemence and persistence of these minor aerial streamlets. It was on an occasion in April weather, when a heavy overcast sky blotted out the upper heavens. In the cloud levels the wind was somewhat sluggish, and for an hour we travelled at an average speed of a little over twenty miles an hour, never higher than 3,000 feet. At this point, while flying over Hertfordshire, we threw out sufficient ballast to cause the balloon to rise clear of the hazy lower air, and coming under the full influence of the sun, then in the meridian, we shot upwards at considerable speed, and soon attained an altitude of three miles. But for a considerable portion of this climb--while, in fact, we were ascending through little less than a mile of our upward course--we were assailed by impetuous cross currents, which whistled through car and rigging and smote us fairly on the cheek. It was altogether a novel experience, and the more remarkable from the fact that our main onward course was not appreciably diverted. Then we got above these currents, and remained at our maximum level, while we floated, still at only a moderate speed, the length of a county. The descent then began, and once again, while we dropped through the same disturbed region, the same far-reaching and obtrusive cross-current assailed us. It was quite obvious that the vehement currents were too slender to tell largely upon the huge surface of the balloon, as it was being swept steadily onwards by the main wind, which never varied in direction from ground levels up to the greatest height attained. This experience is but confirmation of the story of the wind told by the wind gauges on the Forth Bridge. Here the maximum pressure measured on the large gauge of 300 square feet is commonly considerably less than that on the smaller gauge, suggesting that the latter must be due to threads of air of limited area and high velocity. Further and very valuable light is thrown on the peculiar ways of the wind, now being considered, by Professor Langley in the special researches of his to which reference has already been made. This eminent observer and mathematician, suspecting that the old-fashioned instruments, which only told what the wind had been doing every hour, or at best every minute, gave but a most imperfect record, constructed delicate gauges, which would respond to every impulse and give readings from second to second. In this way he established the fact that the wind, far from being a body of even approximate uniformity, is under most ordinary conditions irregular almost beyond conception. Further, that the greater the speed the greater the fluctuations, so that a high wind has to be regarded as "air moving in a tumultuous mass," the velocity at one moment perhaps forty miles an hour, then diminishing to an almost instantaneous calm, and then resuming. "In fact, in the very nature of the case, wind is not the result of one simple cause, but of an infinite number of impulses and changes, perhaps long passed, which are preserved in it, and which die only slowly away." When we come to take observations of temperature we find the conditions in the atmosphere above us to be at first sight not a little complex, and altogether different in day and night hours. From observations already recorded in this volume--notably those of Gay Lussac, Welsh, and Glaisher--it has been made to appear that, in ascending into the sky in daytime, the temperature usually falls according to a general law; but there are found regions where the fall of temperature becomes arrested, such regions being commonly, though by no means invariably, associated with visible cloud. It is probable, however, that it would be more correct not to interpret the presence of cloud as causing manifestation of cold, but rather to regard the meeting of warm and cold currents as the cause of cloud. The writer has experimented in the upper regions with a special form of air thermometer of great sensibility, designed to respond rapidly to slight variations of temperature. Testing this instrument on one occasion in a room of equable warmth, and without draughts, he was puzzled by seeing the index in a capillary tube suddenly mounting rapidly, due to some cause which was not apparent, till it was noticed that the parlour cat, attracted by the proceedings, had approached near the apparatus. The behaviour of this instrument when slung in the clear some distance over the side of the balloon car, and carefully watched, suggests by its fitful, sudden, and rapid changes that warmer currents are often making their way in such slender wandering rills as have been already pictured as permeating the broader air streams. During night hours conditions are reversed. The warmer air radiated off the earth through the day has then ascended. It will be found at different heights, lying in pools or strata, possibly resembling in form, could they be seen, masses of visible cloud. The writer has gathered from night voyages instructive and suggestive facts with reference to the ascent of air streams, due to differences of temperature, particularly over London and the suburbs, and it is conceivable that in such ascending streams may lie a means of dealing successfully with visitations of smoke and fog. One lesson taught by balloon travel has been that fog or haze will come or go in obedience to temperature variations at low levels. Thus thick haze has lain over London, more particularly over the lower parts, at sundown. Then through night hours, as the temperature of the lower air has become equalised, the haze has completely disappeared, but only to reassert itself at dawn. A description of the very impressive experience of a night sail over London has been reserved, but should not be altogether omitted. Glaisher, writing of the spectacle as he observed it nearly forty years ago, describes London seen at night from a balloon at a distance as resembling a vast conflagration. When actually over the town, a main thoroughfare like the Commercial Road shone up like a line of brilliant fire; but, travelling westward, Oxford Street presented an appearance which puzzled him. "Here the two thickly studded rows of brilliant lights were seen on either side of the street, with a narrow, dark space between, and this dark space was bounded, as it were, on both sides by a bright fringe like frosted silver." Presently he discovered that this rich effect was caused by the bright illumination of the shop lights on the pavements. London, as seen from a balloon on a clear moonlight night in August a year ago (1901), wore a somewhat altered appearance. There were the fairy lamps tracing out the streets, which, though dark centred, wore their silver lining; but in irregular patches a whiter light from electric arc lamps broadened and brightened and shone out like some pyrotechnic display above the black housetops. Through the vast town ran a blank, black channel, the river, winding on into distance, crossed here and there by bridges showing as bright bands, and with bright spots occasionally to mark where lay the river craft. But what was most striking was the silence. Though the noise of London traffic as heard from a balloon has diminished of late years owing to the better paving, yet in day hours the roar of the streets is heard up to a great height as a hard, harsh, grinding din. But at night, after the last 'bus has ceased to ply, and before the market carts begin lumbering in, the balloonist, as he sails over the town, might imagine that he was traversing a City of the Dead. It is at such times that a shout through a speaking trumpet has a most startling effect, and more particularly a blast on a horn. In this case after an interval of some seconds a wild note will be flung back from the house-tops below, answered and re-answered on all sides as it echoes from roof to roof--a wild, weird uproar that awakes suddenly, and then dies out slowly far away. Experiments with echoes from a balloon have proved instructive. If, when riding at a height, say, of 2,000 feet, a charge of gun-cotton be fired electrically 100 feet below the car, the report, though really as loud as a cannon, sounds no more than a mere pistol shot, possibly partly owing to the greater rarity of the air, but chiefly because the sound, having no background to reflect it, simply spends itself in the air. Then, always and under all conditions of atmosphere soever, there ensues absolute silence until the time for the echo back from earth has fully elapsed, when a deafening outburst of thunder rises from below, rolling on often for more than half a minute. Two noteworthy facts, at least, the writer has established from a very large number of trials: first, that the theory of aerial echoes thrown back from empty space, which physicists have held to exist constantly, and to be part of the cause of thunder, will have to be abandoned; and, secondly, that from some cause yet to be fully explained the echo back from the earth is always behind its time. But balloons have revealed further suggestive facts with regard to sound, and more particularly with regard to the varying acoustic properties of the air. It is a familiar experience how distant sounds will come and go, rising and falling, often being wafted over extraordinary distances, and again failing altogether, or sometimes being lost at near range, but appearing in strength further away. A free balloon, moving in the profound silence of the upper air, becomes an admirable sound observatory. It may be clearly detected that in certain conditions of atmosphere, at least, there are what may be conceived to be aerial sound channels, through which sounds are momentarily conveyed with abnormal intensity. This phenomenon does but serve to give an intelligible presentment of the unseen conditions existing in the realm of air. It would be reasonable to suppose that were an eye so constituted as to be able to see, say, cumulus masses of warmer air, strata mottled with traces of other gases, and beds of invisible matter in suspension, one might suppose that what we deem the clearest sky would then appear flecked with forms as many and various as the clouds that adorn our summer heavens. But there is matter in suspension in the atmosphere which is very far from invisible, and which in the case of large towns is very commonly lying in thick strata overhead, stopping back the sunlight, and forming the nucleus round which noisome fogs may form. Experimenting with suitable apparatus, the writer has found on a still afternoon in May, at 2,000 feet above Kingston in Surrey, that the air was charged far more heavily with dust than that of the London streets the next day; and, again, at half a mile above the city in the month of August last dust, much of it being of a gross and even fibrous nature, was far more abundant than on grass enclosures in the town during the forenoon of the day following. An attempt has been made to include England in a series of international balloon ascents arranged expressly for the purpose of taking simultaneous observations at a large number of stations over Europe, by which means it is hoped that much fresh knowledge will be forthcoming with respect to the constitution of the atmosphere up to the highest levels accessible by balloons manned and unmanned. It is very much to be regretted that in the case of England the attempt here spoken of has rested entirely on private enterprise. First and foremost in personal liberality and the work of organisation must be mentioned Mr. P. Y. Alexander, whose zeal in the progress of aeronautics is second to none in this country. Twice through his efforts England has been represented in the important work for which Continental nations have no difficulty in obtaining public grants. The first occasion was on November 8th, 1900, when the writer was privileged to occupy a seat in the balloon furnished by Mr. Alexander, and equipped with the most modern type of instruments. It was a stormy and fast voyage from the Crystal Palace to Halstead, in Essex, 48 miles in 40 minutes. Simultaneously with this, Mr. Alexander dismissed an unmanned balloon from Bath, which ascended 8,000 feet, and landed at Cricklade. Other balloons which took part in the combined experiment were two from Paris, three from Chalais Meudon, three from Strasburg, two from Vienna, two from Berlin, and two from St. Petersburg. The section of our countrymen specially interested in aeronautics--a growing community--is represented by the Aeronautical Society, formed in 1865, with the Duke of Argyll for president, and for thirty years under the most energetic management of Mr. F. W. Brearey, succeeding whom as hon. secs. have been Major Baden-Powell and Mr. Eric S. Bruce. Mr. Brearey was one of the most successful inventors of flying models. Mr. Chanute, speaking as President of the American Society of Civil Engineers, paid him a high and well-deserved compliment in saying that it was through his influence that aerial navigation had been cleared of much rubbish and placed upon a scientific and firm basis. Another community devoting itself to the pursuit of balloon trips and matters aeronautical generally is the newly-formed Aero Club, of whom one of the most prominent and energetic members is the Hon. C. S. Rolls. It had been announced that M. Santos-Dumont would bring an air ship to England, and during the summer of the present year would give exhibitions of its capability. It was even rumoured that he might circle round St. Paul's and accomplish other aerial feats unknown in England. The promise was fulfilled so far as bringing the air ship to England was concerned, for one of his vessels which had seen service was deposited at the Crystal Palace. In some mysterious manner, however, never sufficiently made clear to the public, this machine was one morning found damaged, and M. Santos-Dumont has withdrawn from his proposed engagements. In thus doing he left the field open to one of our own countrymen, who, in his first attempt at flight with an air ship of his own invention and construction, has proved himself no unworthy rival of the wealthy young Brazilian. Mr. Stanley Spencer, in a very brief space of time, designed and built completely in the workshops of the firm an elongated motor balloon, 75 feet long by 20 feet diameter, worked by a screw and petrol motor. This motor is placed in the prow, 25 feet away from, and in front of, the safety valve, by which precaution any danger of igniting the escaping gas is avoided. Should, however, a collapse of the machine arise from any cause, there is an arrangement for throwing the balloon into the form of a parachute. Further, there is provided means for admitting air at will into the balloon, by which the necessity for much ballast is obviated. Mr. Spencer having filled the balloon with pure hydrogen, made his first trial with this machine late in an evening at the end of June. The performance of the vessel is thus described in the Westminster Gazette:--"The huge balloon filled slowly, so that the light was rapidly failing when at last the doors of the big shed slid open and the ship was brought carefully out, her motor started, and her maiden voyage commenced. With Mr. Stanley Spencer in the car, she sailed gracefully down the football field, wheeled round in a circle--a small circle, too--and for perhaps a quarter of an hour sailed a tortuous course over the heads of a small but enthusiastic crowd of spectators. The ship was handicapped to some extent by the fact that in their anxiety to make the trial the aeronauts had not waited to inflate it fully, but still it did its work well, answered its helm readily, showed no signs of rolling, and, in short, appeared to give entire satisfaction to everybody concerned--so much so, indeed, that Mr. Stanley Spencer informed the crowd after the ascent that he was quite ready to take up any challenge that M. Santos Dumont might throw down." Within a few weeks of this his first success Mr. Spencer was able to prove to the world that he had only claimed for his machine what its powers fully justified. On a still September afternoon, ascending alone, he steered his aerial ship in an easy and graceful flight over London, from the Crystal Palace to Harrow. CHAPTER XXIX. CONCLUSION. The future development of aerostation is necessarily difficult to forecast. Having reviewed its history from its inception we have to allow that the balloon in itself, as an instrument of aerial locomotion, remains practically only where it was 120 years ago. Nor, in the nature of the case, is this to be wondered at. The wind, which alone guides the balloon, is beyond man's control, while, as a source of lifting power, a lighter and therefore more suitable gas than hydrogen is not to be found in nature. It is, however, conceivable that a superior mode of inflation may yet be discovered. Now that the liquefaction of gases has become an accomplished fact, it seems almost theoretically possible that a balloonist may presently be able to provide himself with an unlimited reserve of potential energy so as to be fitted for travel of indefinite duration. Endowed with increased powers of this nature, the aeronaut could utilise a balloon for voyages of discovery over regions of the earth which bar man's progress by any other mode of travel. A future Andree, provided with a means of maintaining his gas supply for six weeks, need have no hesitation in laying his course towards the North Pole, being confident that the winds must ultimately waft him to some safe haven. He could, indeed, well afford, having reached the Pole, to descend and build his cairn, or even to stop a week, if he so desired, before continuing on his way. But it may fairly be claimed for the balloon, even as it now is, that a great and important future is open to it as a means for exploring inaccessible country. It may, indeed, be urged that Andree's task was, in the very nature of the case, well nigh impracticable, and his unfortunate miscarriage will be used as argument against such a method of exploration. But it must always be remembered that in Andree's case the rigours of climate which he was compelled to face were the most serious of all obstacles to balloon travel. The extreme cold would not only cause constant shrinkage of the gas, but would entail the deposition of a weight of moisture, if not of snow, upon the surface of the balloon, which must greatly shorten its life. It would be entirely otherwise if the country it were sought to explore were in lower latitudes, in Australia, or within the vast unknown belt of earth lying nearer the equator. The writer's scheme for exploring the wholly unknown regions of Arabia is already before the public. The fact, thought to be established by the most experienced aeronauts of old times, and already referred to in these pages, that at some height a strong west wind is to be found blowing with great constancy all round the globe, is in accordance with the view entertained by modern meteorologists. Such a wind, too, may be expected to be a fairly fast wind, the calculation being that, as a general rule, the velocity of currents increases from the ground at the rate of about three miles per hour for each thousand feet of height; thus the chance of a balloon drifting speedily across the breadth of Arabia is a strong one, and, regarded in this light, the distance to be traversed is certainly not excessive, being probably well within the lasting power of such a balloon as that employed by Andree. If, for the sake of gas supply, Aden were chosen for the starting ground, then 1,200 miles E.N.E. would carry the voyager to Muscat; 1,100 miles N.E. by E. would land him at Sohar; while some 800 miles would suffice to take him to the seaboard if his course lay N.E. It must also be borne in mind that the Arabian sun by day, and the heat radiated off the desert by night, would be all in favour of the buoyancy of the balloon. But there are other persistent winds that, for purposes of exploration, would prove equally serviceable and sure. From time immemorial the dweller on the Nile has been led to regard his river in the light of a benignant deity. If he wished to travel down its course he had but to entrust his vessel to the stream, and this would carry him. If, again, he wished to retrace his course, he had but to raise a sail, and the prevalent wind, conquering the flood, would bear him against the stream. This constant north wind, following the Nile valley, and thence trending still southward towards Uganda, has been regarded as a means to hand well adapted for the exploration of important unsurveyed country by balloon. This scheme has been conceived and elaborated by Major B.F.S. Baden-Powell, and, so far, the only apparent obstacle in the way has proved the lack of necessary funds. It will be urged, however, that for purposes of exploration some form of dirigible balloon is desirable, and we have already had proof that where it is not sought to combat winds strongly opposed to their course such air ships as Santos-Dumont or Messrs. Spencer have already constructed acquit themselves well; and it requires no stretch of imagination to conceive that before the present century is closed many great gaps in the map of the world will have been filled in by aerial survey. But, leaving the balloon to its proper function, we turn to the flying machine properly so called with more sanguine hopes of seeing the real conquest of the air achieved. It was as it were but yesterday when the air ship, unhampered by huge globes of gas, and controlled by mechanical means alone, was first fairly tried, yet it is already considered by those best able to judge that its ultimate success is assured. This success rests now solely in the hands of the mechanical engineer. He must, and surely can, build the ship of such strength that some essential part does not at the critical moment break down or carry away. He may have to improve his motive power, and here, again, we do not doubt his cunning. Motor engines, self-contained and burning liquid fuel, are yet in their infancy, and the extraordinary emulation now existing in their production puts it beyond doubt that every year will see rapid improvement in their efficiency. We do not expect, nor do we desire, that the world may see the fulfilment of the poet's dream, "Argosies of magic sails" or "Airy navies grappling in the central blue." We would not befog our vision of the future with any wild imaginings, seeking, as some have done, to see in the electricity or other hidden power of heaven the means for its subjugation by man; but it is far from unreasonable to hope that but a little while shall pass, and we shall have more perfect and reliable knowledge of the tides and currents in the vast ocean of air, and when that day may have come then it may be claimed that the grand problem of aerial navigation will be already solved. 
47129	----	FLYING THE ATLANTIC IN SIXTEEN HOURS [Illustration: CAPT. SIR ARTHUR WHITTEN BROWN, K.B.E.] FLYING THE ATLANTIC IN SIXTEEN HOURS WITH A DISCUSSION OF AIRCRAFT IN COMMERCE AND TRANSPORTATION BY SIR ARTHUR WHITTEN BROWN, K.B.E. ASSISTED BY CAPTAIN ALAN BOTT, R.F.C. _WITH TWENTY-ONE ILLUSTRATIONS FROM PHOTOGRAPHS_ [Illustration] NEW YORK FREDERICK A. STOKES COMPANY PUBLISHERS _Copyright, 1920, by_ FREDERICK A. STOKES COMPANY _All rights reserved, including that of translation into foreign languages._ CONTENTS CHAPTER PAGE I SOME PRELIMINARY EVENTS 1 II ST. JOHN'S 15 III THE START 32 IV EVENING 47 V NIGHT 55 VI MORNING 65 VII THE ARRIVAL 75 VIII AFTERMATH OF ARRIVAL 84 IX THE NAVIGATION OF AIRCRAFT 93 X THE FUTURE OF TRANSATLANTIC FLIGHT 108 XI THE AIR AGE 136 ILLUSTRATIONS Capt. Sir Arthur Whitten Brown, K.B.E. _Frontispiece_ FACING PAGE The Late Capt. Sir John Alcock, K.B.E., D.S.C. 14 Feathering the Wings--Setting Up the Flier at St. John's, N.F. 30 The Last Touches--Adjusting the Bracing Wires 30 It Was Hard to Find an Aërodrome with Sufficient "Take Off" 44 Sightseers, If Left to Themselves, Would Have Wrecked the Machine 44 The Transatlantic Machine--A Vickers-Vimy With Rolls-Royce Engines 56 A Special Kind of Gasoline Had to Be Used 70 All Aboard for the First Trial Flight 70 The Vickers-Vimy Transatlantic Machine in the Air 84 The Last Square Meal in America Was Eaten Near the Wings of the Machine 84 The Late Capt. Sir John Alcock Just Before Starting 98 Shipping the First Direct Transatlantic Air Mail 98 Hot Coffee Was Taken Aboard 104 Slow Rising Nearly Caused Disaster at the Start of the Great Flight 104 Lucky Jim and Twinkletoe, the Mascots 120 The Transatlantic Flight Ended With a Crash in an Irish Bog 120 Chart of the North Atlantic Showing Course of the Flight 136 The Men Who Worked Without Glory to Make the Flight Possible 136 The Vickers Aeroplane Works at Weybridge, England 154 Comfort Can Be Enjoyed in Air Travel To-day 154 FLYING THE ATLANTIC IN SIXTEEN HOURS CHAPTER I SOME PRELIMINARY EVENTS "After me cometh a builder. Tell him I, too, have known." KIPLING. It is an awful thing to be told that one has made history, or done something historic. Such an accusation implies the duty of living up to other people's expectations; and merely an ordinary person who has been lucky, like myself, cannot fulfil such expectations. Sir John Alcock and I have been informed so often, by the printed and spoken word, that our achievement in making the first non-stop transatlantic flight is an important event in the history of aviation that almost--but not quite--I have come to believe it. And this half-belief makes me very humble, when I consider the splendid company of pioneers who, without due recognition, gave life, money or precious years, often all three, to further the future of aëronautics--Lilienthal, Pilcher, Langley, Eiffel, Lanchester, Maxim, the Wrights, Bleriot, Cody, Roe, Rolls and the many daring men who piloted the weird, experimental craft which were among the first to fly. I believe that ever since Man, but recently conscious of his own existence, saw the birds, he has desired to emulate them. Among the myths and fables of every race are tales of human flight. The paradise of most religions is reached through the air, and through the air gods and prophets have passed from earth to their respective heavens. And all authentic angels are endowed with wings. The present generation is lucky in that, despite this instinctive longing since the beginning of human history for the means of flight, it is the first to see dreams and theories translated into fact by the startling development of practical aviation, within the past fifteen years. The aëronautical wonders of the next fifteen years are likely to be yet more startling. Five years ago, before the offensive and defensive needs of war provided a supreme _raison d'être_, flying was but a costly and dangerous pastime. As such it attracted the first-class adventurers of every race, many of whom lost their lives on weird, Jabberwock-like aircraft, built and tested before experimental data and more accurate methods of calculation became available. But even these men could not realize the wonderful possibilities of the coming air age, of which they were the pioneers. Nearly all the early aëroplanes were born of private enterprise, for capitalists had no faith in the commercial future of flight. Very few firms applied themselves solely to the manufacture of aircraft or aëro engines, and only two or three of the great engineering companies had the vision to maintain aëronautical departments. Among the few important companies that, in those days, regarded aëronautics seriously was Messrs. Vickers, Ltd. They established an experimental department, and as a result of its work began to produce military types of aircraft which were in advance of their period. Later, when the whirlwind of war provided the impetus which swept pioneer aviation into headlong progress, the Vickers productions moved with the times, and helped largely to make the British aircraft industry the greatest in the world. Now that aviation has entered into the third phase of its advance--that of a peace-time commercial proposition--they are again in the forefront of production. Incidentally they provided me with the greatest chance of my life--that of taking part in the first non-stop flight across the Atlantic. Since then a Vickers aëroplane has won yet another great distinction--the prize for the first flight from England to Australia. At this point I desire to pay a very well-deserved tribute to the man who from the beginning has backed with money his faith in the future of aviation. The development of aëronautics has been helped enormously by the generous prizes of Lord Northcliffe and the _Daily Mail_ for the first flights across the English Channel, from London to Manchester, around the circuit of Britain, and finally across the Atlantic. In each case the competitions seemed impossible of fulfilment at the time when they were inaugurated; and in each case the unimaginative began with scoffing doubts and ended with wondering praise. Naturally, the prizes were offered before they could be won, for they were intended to stimulate effort and development. This object was achieved. But for the stimulus of these competitions, Great Britain, at the beginning of the war, might well have been in an even worse position as regards aviation than she was. And all who flew on active service during the first three years of the war realize what they owe to Lord Northcliffe's crusades for more and better machines, and for a more extensive use of aircraft. Having helped to win one of the _Daily Mail_ prizes, I am not going to quarrel with the principle of flying competitions. Certainly, the promise of reward brings to the surface ideas and potential powers which might otherwise lie fallow; but I do not believe the system of money prizes for spectacular flights to be altogether an economically sound proposition. It is not generally realized that as a rule the amount spent by each of the firms that enter a machine for such a contest as the transatlantic flight vastly exceeds the amount of the prize, although the money reward more than covers the expenses of the aviators who gain it. Would it not be more practical to pay directly for research work? Anybody with vision can see some of the infinite possibilities which the future of aviation may hold, and which can only be found by painstaking and properly applied research. There are plenty of men able and anxious to devote themselves competently to seeking for yet-hidden solutions whereby flying will be made cheaper, safer and more reliable. What is especially wanted for the moment is the financial endowment of research into the several problems that must be solved before the air age makes the world a better place to live in, and, by eliminating long and uncomfortable journeys, brings the nations into closer bonds of friendship, understanding and commerce. Apart from the honor of taking part in the first non-stop flight between America and Great Britain, I am especially pleased to have helped in a small way in the construction of a new link between the two continents to which I belong. My family is deeply rooted in the United States; but generations ago my ancestors were English, and I myself happened to be born in Glasgow. This was in 1886, when my parents were visiting that city. I was an only child, and I was so well looked after that I caught neither a Scotch nor an American nor even a Lancashire accent; for later, between visits to the United States, we lived in Manchester. There, after leaving school, I served an apprenticeship in the works of the Westinghouse Electric and Manufacturing Company. I inherited in some degree a love of and an instinct for engineering from my father, one of the best mechanical engineers I have ever met. He helped to develop this instinct by encouraging me in everything I undertook, and by making me profit by the results of his experience. In the works I was for a time a workman among workmen--a condition of life which is the best possible beginning for an embryo engineer. I found my associates of the workshop good companions, useful instructors and incorrigible jokers. My father's warnings, however, saved me from hours of waiting in the forge, at their direction, while a "straight hook" or a "putting-on tool" was made, and from hunting the shops for the "spare short-circuit." I was congratulating myself on making good headway and, in articles accepted by various technical journals, was even telling my elders all about engineering, when the outbreak of war changed all my plans and hopes, and interfered with the career I had mapped out for myself. In fact, I was in exactly the same position as many thousands of other young men at the beginning of their careers. Although, of American parentage and possessing American citizenship, I had not the patience to wait for the entry into the war of the United States. With an English friend I enlisted in the British University and Public Schools battalion, when it was formed in September, 1914. And, although at the time I had no more notion of it than of becoming President of the League of Nations, that was my first step towards the transatlantic flight. Those were wonderful days for all concerned in the early training of our battalion at Epsom. In knowledge of drill our officers started level with us. Several times I saw a private step from the ranks, produce from his pocket the Infantry Training Manual, and show a lieutenant where he had gone wrong. Doubtful discipline, perhaps--but excellent practice, for most of the original privates of the U.P.S. soon became officers of the New Army. I was gazetted a second lieutenant of the Manchester Regiment in January, 1915, and with it saw service in the trenches before Ypres and on the Somme. Then came the second step towards the transatlantic flight. I had always longed to be in the air, and I obtained a transfer to the Royal Flying Corps as an observer. I had the good fortune to be posted to No. 2 Squadron, under Major (now General) Becke. While in this unit I first experienced the mixed sensations of being shot down. One day my pilot and I were carrying out artillery observation over Vendin la Vielle when, at a height of 8,000 feet, two anti-aircraft shells set our machine on fire. Somehow, the pilot managed to bring down his craft in the British lines; but in landing it tripped over some telephone wires and turned a somersault, still blazing at various points. We were thrown out, but escaped with a few burns and bruises. After a short rest in England I returned to the squadron. I soon left it for good, however. One dull, snowy day a bullet perforated the petrol tank of the machine in which, with Lieut. Medlicott, I was reconnoitering behind the enemy lines. As a result we were unable to reach the British zone. We landed in occupied territory; and I knew the deadly heart-sickness which comes to all prisoners of war during the first few days of their captivity. I was repatriated after being a prisoner of war in Germany for fourteen months, followed by nine months in Switzerland. Medlicott, meanwhile, made thirteen determined but unsuccessful bids for escape before being murdered by the Germans in 1918, while indulging in a fourteenth attempt. My two years of captivity constituted, strange to say, the third step towards the transatlantic flight; for it was as a prisoner of war that I first found time to begin a careful study of the possibilities of aërial navigation. This I continued after returning to London, where, at the Ministry of Munitions, I was employed in the production of the larger aëro-engines. When, soon after the armistice, the ban on attempts to fly the Atlantic was lifted, I hoped that my studies of aërial navigation might be useful to one of the firms who were preparing for such a flight. Each one I approached, however, refused my proposals, and for the moment I gave up the idea. It was entirely by chance that I became involved in the transatlantic competition. One day I visited the works at Weybridge of Messrs. Vickers. While I was talking with the superintendent, Captain Alcock walked into the office. We were introduced, and in the course of conversation the competition was mentioned. I then learned, for the first time, that Messrs. Vickers were considering an entry, although not courting publicity until they should have attempted it. I sat up and began to take notice, and ventured to put forward my views on the navigation of aircraft for long flights over the sea. These were received favorably, and the outcome of the fortunate meeting was that Messrs. Vickers retained me to act as aërial navigator. I soon learned to have every confidence in the man who was to be my pilot. He flew for years before the war, and he had a magnificent record for long-distance flying when engaged in bombing Constantinople and other parts of Turkey, with the detachments of the Royal Naval Air Service in the Eastern Mediterranean. His recent death in a flying accident took from aviation one of its most able, experienced and courageous pilots, and robbed his many friends of a splendid man. We set to work, and, with every assistance from the Air Ministry, and the Admiralty, we soon had our apparatus and instruments ready for shipment to Newfoundland. Besides our two selves the Vickers transatlantic party consisted of ten other men from the works, and a specialist on Rolls-Royce aëro-engines. Alcock and I sailed from Southampton on the _Mauretania_, on board of which its commander--Captain Rostron--made me free of his bridge, and, as a widely experienced navigator, gave me much good advice. The Vickers-Vimy machine, with all stores, left later by a freight boat. From Halifax, Nova Scotia, we proceeded to Port aux Basques, and thence by way of the Reid Newfoundland Railway to St. John's. There, we joined the merry and hopeful company of British aviators who, long before we arrived, had been preparing for an attempt to win Lord Northcliffe's prize. That four of them did not forestall us was due in part to very bad luck, and in part to their whole-hearted patriotism. They wanted for their country the honor of the first transatlantic flight, whether non-stop or otherwise; and, being unable to continue the wearisome wait for good weather in face of the news that the American flying boat _N. C. 4_ had reached the Azores, they made their attempt under conditions that were definitely unfavorable. Fate tripped up Raynham and Morgan at the start, when they tried to take their heavily-laden machine into the air while running over a too short space of uneven ground, with the wind crossways to it. Fate allowed Hawker and Grieve a rather longer run, but brought about their fall when they were half-way to success, owing to a mishap which, though trifling, had the same effect as a vital breakage. It is superfluous, at this time of day, to offer public sympathy to such gallant competitors; but I seize the opportunity of expressing admiration for their splendid effort, and for the spirit that prompted it. To Hawker and Grieve we owed particular thanks in that we profited to a certain extent by what we learned from the cabled reports of their experiences. For Grieve, as an expert on aërial navigation, I have the deepest respect, and I am in full accord with his views and theories on this, my own subject. The same sort of odds against accident that sent them into the sea might well have befallen Alcock and me. But it did not; and our freedom from it was an important factor in our good fortune. Others were the excellence of the Vickers-Vimy machine and the Rolls-Royce engine. Whatever credit is ours should be shared with them, and with Mr. R. E. Pierson, E.Sc., M.I.C.E., the designer of the Vickers-Vimy. We have realized that our flight was but a solitary fingerpost to the air-traffic--safe, comfortable and voluminous--that in a few years will pass above the Atlantic Ocean; and even had the winning of the competition brought us no other benefits, each of us would have remained well content to be pioneers of this aërial entente which is destined to play such an important part in the political and commercial friendship between Great Britain and America. [Illustration: THE LATE CAPT. SIR JOHN ALCOCK, K.B.E., D.S.C.] CHAPTER II ST. JOHN'S "Hawker left this afternoon." This message was shouted by a chance-met motorist, who held up our own car as we were driving back to St. John's from Ferryland on the evening of May the eighteenth, after an unsuccessful search for an aërodrome site. "And Raynham?" I asked. "Machine smashed before he could get it off the ground." We thanked the stranger for his news, and passed on to hear further details at the Cochrane Hotel, which was the headquarters of the several transatlantic flight contingents at St. John's. We had rather expected the Sopwith and Martinsyde parties to make an attempt on the eighteenth, although the conditions were definitely unfavorable. The news of the American _N. C. 4's_ arrival at the Azores had spurred them to the great adventure, despite the weather. The United States flying boats were not competing for the _Daily Mail_ prize; but Hawker and Grieve wanted to gain for Great Britain the honor of being the first to cross the Atlantic by air. The outcome of this ambition was the gallant effort that ended in the sea, half-way to Ireland. While exceedingly sorry for Raynham, we were glad that Hawker had started, after his weeks of weary waiting, and we wished him all success; for with one exception there was the best possible feeling among the small colony of British aviators who had congregated at St. John's for the transatlantic competition. In any case, if Hawker succeeded and we no longer had a chance of winning the prize, we meant to demonstrate the high qualities of the Vickers-Vimy machine by flying from Newfoundland to Ireland. We had arrived at St. John's early on the morning of May the thirteenth, being only twelve hours late on a scheduled time of twenty-seven hours for the journey from Port aux Basques. Thirteen, by the way, we regarded as our lucky number. The construction of our transatlantic machine was begun on February thirteenth, it was number thirteen of its class, and it reached Newfoundland on May twenty-sixth (twice thirteen). Our party, with the mechanics, totaled thirteen, and we arrived at St. John's on May thirteenth. Later we were disappointed at having to postpone the getaway until June fourteenth, instead of leaving on June thirteenth. We hired a car, and, driving to Mount Pearl, began what was to be a long and difficult hunt for any kind of a field that could be improvised into an aërodrome. The uneven countryside through which we passed held out no hopes; and the company we met that evening at the Cochrane Hotel (Hawker, Grieve, Raynham, Morgan, and various officials and newspaper correspondents) were unanimous in declaring that the only suitable patches of ground had been appropriated, and that we should find no others near St. John's. The American flying boats were at Trepassey, ready to start for the Azores, and most of the American correspondents had left St. John's to visit them. The United States airship _N. C. 5_ had flown to St. John's some days before our arrival. She came in a fog, after wandering over the neighborhood of Newfoundland for some hours, having lost herself, it was reported, owing to an error of 180° in the directional wireless bearings given her. She attracted large crowds, ourselves among them, to the bay. Later, we saw the airship steering an erratic course through the Gap, and mentally wished her commander good luck in his transatlantic ambitions. Soon afterwards we heard of her unfortunate break-away and total loss. The departure of the N. C. flying boats sent great excitement into the small company of Britishers at the Cochrane Hotel. Hawker, Grieve, Raynham and Morgan discarded caution, and on hearing of the _N. C. 4's_ arrival at the Azores risked exceedingly their chances of success by agreeing to start immediately, in a whole-hearted and plucky effort to gain for Great Britain the honor of the first flight across the Atlantic. The result was immediate disaster for Raynham and Morgan, whose small aërodrome was altogether unsuitable for a "take off" into the then wind, and magnificent failure for Hawker and Grieve, owing to a minor mishap to their engine. Soon after the flight of the American craft, I met Commander Byrd, U. S. N., designer of the bubble sextant for aërial navigation that bears his name. We had an interesting talk on the problems and difficulties of aërial navigation, and I tried to secure from Washington a Byrd sextant. The United States Naval authorities promised to forward one from Washington; but unfortunately, owing to transport difficulties, it reached St. John's after our departure. Nevertheless I am deeply grateful to the United States Navy Department for its courtesy and its offer of help in an enterprise that was foreign to them and non-official. Newfoundland is a hospitable place, but its best friends cannot claim that it is ideal for aviation. The whole of the island has no ground that might be made into a first-class aërodrome. The district around St. John's is especially difficult. Some of the country is wooded, but for the most part it shows a rolling, switchback surface, across which aëroplanes cannot taxi with any degree of smoothness. The soil is soft and dotted with bowlders, for only a light layer of it covers the rock stratum. Another handicap is the prevalence of thick fogs, which roll westward from the sea. For about a week we continued the quest for a landing-ground, and we must have driven over hundreds of miles of very bad road. Growing tired of hiring cars, we bought a second-hand Buick which registered a total mileage of four hundred miles at the time of purchase. Before long we were convinced that the speedometer must have been disconnected previous to the final forty thousand miles. The best possibilities for an aërodrome that we could find were several level strips of meadowland, about a hundred yards wide by three hundred long; whereas the Vickers-Vimy, fully loaded, might need five hundred yards of clear run into the wind. Meanwhile, although disappointment accompanied us all over Newfoundland, the pacing out of fields provided good exercise. The evenings were mostly spent in playing cards with the other competitors at the Cochrane Hotel, or in visits to the neighboring film theaters. St. John's itself showed us every kindness. We explored the town pretty thoroughly, and were soon able to recognize parts of it with eyes closed and nostrils open; for its chief occupation appeared to be the drying of very dead cod. Having heard rumors that suitable ground might be found at Ferryland, we motored there on May the eighteenth, and it was while returning from yet another disappointment that we learned of Hawker's disappearance into the Atlantic mists. Excitement and anxiety about the possible fate of Hawker and Grieve spread all the world over; but nowhere was it more intense than among us at the Cochrane Hotel, who had shared their hopes and discussed their plans. We were a gloomy crowd indeed until St. John's heard the sensational story of their rescue. Raynham, meanwhile, although very disappointed after the setback that damaged his machine, kept alight the candle of hope and the torch of determination. Before it was possible to know whether or not Hawker had succeeded, he made arrangements for repair and decided to try again. He also invited Alcock and me to use his ground for erecting the Vickers-Vimy. A similar invitation was given by Captain Fenn, now in charge of the Sopwith party. Neither aërodrome would be suitable for our final "take off"; but we accepted Raynham's very sporting offer, and arranged to build up the Vickers-Vimy, which was expected to arrive any day, on his aërodrome at Quidi Vidi, while continuing the search for a more suitable field. Our mechanics arrived with machine and engines on May the twenty-sixth, and we set to work at once on its erection. This was carried out in the open air, amid many obstacles and with much improvization, sheerlegs for example, being constructed out of scaffolding poles. Raynham let us use his hangar as a store. All the Vickers party worked hard and cheerfully from early dawn until dark, each man being on strenuous duty from twelve to fourteen hours a day. Two mechanics remained on guard each night, while the remainder drove about three miles to their billets. During the whole of this period of a thousand and one difficulties, each mechanic gave of his best, and I cannot pay too high a tribute to those men who labored for us so competently and painstakingly, and yet received none of the glory. Even those who were but indirectly concerned in the venture searched for opportunities of helping us. The reporters representing the _Daily Mail_, the New York _Times_, and the New York _World_ were often of assistance when extra man-power was required. But for one of the American reporters--Mr. Klauber--we should have been obliged to start without an electric torch when our own failed at the last moment. It was, indeed, a nerve-edging time until the machine approached completion. Each day produced some new difficulty. Alcock kept his head and his temper admirably, however, and his intelligent supervision of the mechanics' work was an effective insurance against loss of time. As the parts of the Vickers-Vimy grew into the semblance of a complete aëroplane it attracted more and more visitors. Many rubbernecks, who seemed to have no other occupation, spent hours in leaning on the nearest fence and watching us. Soon we found it necessary to build a temporary enclosure round the machine. Even that did not keep the curious at a distance. We remained unworried so long as the crowd contented itself with just watching; but the visitors forced us to take special precautions against damage. The testing of the fabric's firmness with the point of an umbrella was a favorite pastime of theirs, and more than once we dispersed small parties whom we found leaning against the trailing-edges, much as Australian soldiers on leave from France used to lean against the lamp-posts of the Strand. One man held his lighted cigar against a wing, and was quite annoyed when asked to keep at a distance. We were still unsuccessful in our search for an aërodrome. One day a telegram arrived from a landowner in Harbor Grace, offering what he called an ideal field. Alcock raced off to inspect and secure it; but when he returned in the evening his one-sided grin told me that we were still out of luck. "The ideal aërodrome" was a meadow about one hundred and fifty by three hundred yards--and the price demanded for its hire was twenty-five thousand dollars plus the cost of getting it ready and an indemnity for all damage. Land _sells_ in Newfoundland at thirty-five cents an acre. Soon afterwards a local inhabitant--Mr. Lester, who had done all our carting--offered us a field under more reasonable conditions, at a place called Monday's Pool. We found it to be a large meadow, half on a hill and with a swamp at the bottom. It possessed, nevertheless, a level surface of about three hundred yards, running east and west. We examined and paced out four other fields on the hilltop, and found that by taking them in we could obtain a full run of five hundred yards. The owners of this additional ground wanted extortionate prices for its use, but after much haggling we closed a deal with them. Thirty laborers, with pick and shovel, set to work to prepare the aërodrome by removing hillocks, blasting bowlders and leveling walls and fences. Finally it was completed, well within the time for the trial flight. During the first few days spent on the erecting of the machine there was little for me to do. I unpacked and verified wireless and navigation equipment, and having rigged up a receiving station on the roof of the Cochrane Hotel, with the consent and help of Lieut. Clare, of the Mount Pearl Naval Wireless Station, I practiced the sending and receiving of wireless messages, and tuning in on various wave-lengths. Rain and high wind caused a delay of three days, during which the machine necessarily remained in the open, with tarpaulins over the engines and only a small windscreen to break the force of the gales. When better conditions arrived the body of the Vickers-Vimy grew slowly into the semblance of a complete aëroplane, spurred thereto by our impatience and the willing work of the mechanics. The wings being in place, the Rolls-Royce experts became busy, examining and checking every little detail of their motors, so that there should be no avoidable trouble on that account. Water for the radiator was filtered, and then boiled in a steel barrel. Our day-to-day watchers from St. John's showed much interest in this boiling process, and asked many questions. They seemed content with our explanation that we were boiling the gasoline so as to remove all water. Several asked whether we filled the planes with gas to make them lighter. Others were disappointed because we did not intend to drop our undercarriage over the sea, as Hawker had done, and prophesied that such neglect would lead to failure. The machine was ready to take the air on the morning of Monday, June the ninth, and we decided to make the first flight that same afternoon. We had meant to keep the news of the forthcoming trial as secret as possible, so as to avoid a crowd. It leaked out, however, and long before the engines were warmed up and tested a large gathering had collected at Quidi Vidi. The weather was on its best behavior, and our "take off" from the ground was perfect in every way. Under Alcock's skillful hands the big Vimy became almost as nippy as a single-seater scout. We headed directly westward, passing over the sea for some fifteen minutes. It was a clear day, and the sea reflected the sky's vivid blue. Near the coast it was streaked and spotted by the glistening white of icebergs and the evanescent appearances and disappearances of white-caps. Trial observation with my navigation instruments proved them to be O. K.; but not a spark could be conjured from the wireless apparatus. The machine and motors seemed in perfect condition. Alcock turned the Vickers-Vimy, and brought us back over St. John's at a height of four thousand feet. Newfoundland from above looked even more bleak and rugged than it did from the ground; and we saw that landing grounds would be impossible on the eastern side of it. We were to descend on the new aërodrome, which we picked out by means of a smudge-fire, lighted as a signal. Alcock made a perfect landing, in an uphill direction. The Vimy ran on, topped the brow, and was heading straight for a fence on the roadside; but the pilot saved a collision by opening up the starboard engine, which swung the craft round before she came to a standstill. We pushed the machine down the hill to the most sheltered part of the field, pegged it down, and roped off a space round it, to keep spectators at a safe distance. The proposed hangar was unfinished, so that the Vickers-Vimy still remained in the open. I dismounted the wireless generator for examination, and next day took it to Mount Pearl Wireless Station, where Lieut. Clare helped me to locate the fault and to remedy it. A far more serious worry now confronted us. The fuel we had intended to carry was a mixture of gasoline and benzol, sent from England. On examination we found in it a peculiar precipitate, like a very soft resin. It was sticky, and had the consistency of India rubber wetted with gasoline; but when dry it reduced to a powder. Naturally we could not afford the risk of letting such a deposit clog our filters and perhaps, owing to stoppage of fuel supply, cause motor failure--that bugbear of every aviator who flies over long distances. It was not definitely proved that the precipitate resulted from the mixture of gasoline and benzol; but so much depended on satisfactory fuel that we dared use none that was doubtful, and we decided to substitute pure gasoline for the mixture. The problem was how to find enough of the quality required--Shell B. Raynham, as much of a sportsman as ever, put his spare stock at our disposal; but fortunately a newly arrived ship brought enough for our needs. Mr. P. Maxwell Muller, who had organized our transatlantic party, also came on this boat. He is a rabid optimist, with the power of infecting others with his hopefulness; and we were glad indeed to see him, and especially to turn over to him such things as unpaid bills. The second trial flight took place on June the twelfth. Once again everything except the wireless apparatus was satisfactory. The transmitter worked well for a short time, but afterwards the insulation on a small transformer in the transmitter failed, giving me a violent shock. After a short time in the air, Alcock made another satisfactory landing. By now we were besieging Lieutenant Clements, the meteorological officer, for weather reports. Besides his own work he had now undertaken the duties of Major Partridge, official starter for the Royal Aëro Club of London. As such he had to place the club's official seal on the Vickers-Vimy. This he did without any superfluous ceremony, his seal insuring that we should not cheat by flying from Newfoundland in one aëroplane and landing on Ireland in another. At that period the weather reports, such as they were, indicated fairly favorable conditions for the flight, and we prepared to make the attempt immediately. At no time were the reports complete, however, owing to the delays in transmission; although Clements made the very best of the meager data at his disposal. We saw the Handley-Page carrying out its initial flights; but we hoped to leave on Friday, June the thirteenth, and thus show it the way across the Atlantic. We worked at high speed on several last-minute jobs. The compasses were swung, the wireless apparatus repaired, more elastic shock-absorbers were wrapped round the axles, the navigating instruments were taken on board, with food and emergency supplies. But with all the hurry and bustle we found that everything could not be ready by Friday the thirteenth, and that a postponement until 4 A. M. on the Saturday was essential. [Illustration: FEATHERING THE WINGS--SETTING UP THE FLIER AT ST. JOHN'S, N. F.] [Illustration: THE LAST TOUCHES--ADJUSTING THE BRACING WIRES] By Friday evening the last coat of dope was dry, and nothing had been overlooked. The only articles missing were some life-saving suits, which we were expecting from the United States. Long afterwards we discovered that these had been delivered to the Bank of Montreal, where the officials, believing that the case contained typewriters, stored it in their cellars. Alcock and I went to bed at 7 P. M. on Friday while the mechanics remained all night with the machine, completing the filling of the tanks and moving it to the position chosen for the start. We were called before dawn, and joined them on the aërodrome at 3:30 A. M. on June the fourteenth. CHAPTER III THE START A large black cat, its tail held high in a comical curve, sauntered by the transatlantic machine as we stood by it, early in the morning; and such a cheerful omen made me more than ever anxious to start. Two other black cats--more intimate if less alive--waited in the Vickers-Vimy. They were Lucky Jim and Twinkletoe, our mascots, destined to be the first air passengers across the Atlantic. Lucky Jim wore an enormous head, an untidy ribbon and a hopeful expression; whereas Twinkletoe was daintily diminutive, and, from the tip of her upright tail to the tip of her stuffed nose, expressed surprise and anxiety. Other gifts that we carried as evidence of our friends' best wishes were bunches of white heather. "Strong westerly wind. Conditions otherwise fairly favorable." Such was the brief summary of the weather conditions given us at 4 A. M. by the meteorological officer. We had definitely decided to leave on the fourteenth, if given half a chance; for at all costs we wanted to avoid a long period of hope deferred while awaiting ideal conditions. At early dawn we were on the aërodrome, searching the sky for a sign and asking information of Lieutenant Clements, the Royal Air Force weather expert. His reports were fairly favorable; but a hefty cross-wind was blowing from the west in uneven gusts, and everybody opined that we had better wait a few hours, in the expectation that it would die down. Meanwhile, Alcock ran the engines and found them to be in perfect condition. Neither could any fault be found with the gray-winged machine, inert but fully loaded, and complete to the last split-pin. It was of the Standard type of Vickers-Vimy bomber; although, of course, bombs and bombing gear were not carried, their weight being usefully replaced by extra storage tanks for gasoline. One of these, shaped like a boat, could be used as a life-saving raft if some accident brought about a descent into the sea. This tank was so placed that it would be the first to be emptied of gasoline. The fittings allowed of its detachment, ready for floating, while the machine lost height in a glide. We hoped for and expected the best; but it was as well to be prepared for the worst. To make communication and coöperation more easy, the seats for both pilot and navigator were side by side in what is usually the pilot's cockpit, the observer's cockpit at the fore-end of the fuselage being hidden under a stream-lined covering and occupied by a tank. The tanks had been filled during the night, so that the Vickers-Vimy contained its full complement of eight hundred and seventy gallons of gasoline and forty gallons of oil. We now packed our personal luggage, which consisted only of toilet kit and food--sandwiches, Caley's chocolate, Horlick's Malted Milk, and two thermos flasks filled with coffee. A small cupboard, fitted into the tail, contained emergency rations. These were for use in case of disaster, as the tail of the aëroplane would remain clear of the waves for a long while after the nose had submerged. Our mascots, also, were in this cupboard. The mail-bag had been taken on board a day earlier. It contained three hundred private letters, for each of which the postal officials at St. John's had provided a special stamp. For one of these stamps, by the way, eight hundred and seventy-five dollars was offered and refused on the Manchester Exchange within two days of the letter's delivery. They are now sold at about one hundred and twenty-five dollars apiece, I believe. We breakfasted, and throughout the morning waited for a weakening of the wind. As, however, it remained at about the same strength and showed no signs of better behavior, we made up our minds to leave at mid-day. We had planned to get away in an easterly direction, for although we should thus be moving with the wind instead of into it, the machine would face down-hill, and owing to the shape of the aërodrome we should have a better run than if we taxied towards the west. The Vickers-Vimy was therefore placed in position to suit these arrangements. But soon we found that the gale was too strong for such a plan, and that we should have to "take off" into it. The mechanics dragged the machine to the far end of the aërodrome, so as to prepare for a westerly run. This change was responsible for a minor setback. A sudden gust carried a drag-rope round the undercarriage, tightened one of the wheels against a petrol supply pipe, and crushed it. The consequent replacement wasted about an hour. Still with hopes that the gale would drop during the early afternoon, we sat under the wing-tips at two o'clock and lunched, while conscious of an earnest hope that the next square meal would be eaten in Ireland. The wind remaining obstinately strong during the early afternoon, we agreed to take things as they were and to lose no more precious time. At about four o'clock we wriggled into our flying-kit, and climbed into the machine. We wore electrically heated clothing, Burberry overalls, and the usual fur gloves and fur-lined helmets. While Alcock attended to his engines I made certain that my navigation instruments were in place. The sextant was clipped to the dashboard facing the pilot, the course and distance calculator was clasped to the side of the fuselage, the drift-indicator fitted under my seat, and the Baker navigation machine, with my charts inside it, lay on the floor of the cockpit. I also carried an electric torch, and kept within easy reach a Very pistol, with red and white flares, so that if the worst should happen we could attract the attention of passing ships. The battery for heating our electric suits was between the two seats. The meteorological officer gave me a chart showing the approximate strength and direction of the Atlantic air currents. It indicated that the high westerly wind would drop before we were a hundred miles out to sea, and that the wind velocities for the rest of the journey would not exceed twenty knots, with clear weather over the greater part of the ocean. This was responsible for satisfactory hopes at the time of departure; but later, when we were over mid-Atlantic, the hopes dissolved in disappointment when the promised "clear weather" never happened. The departure was quiet and undramatic. Apart from the mechanics and a few reporters, few people were present, for the strong wind had persuaded our day-to-day sightseers from St. John's that we must postpone a start. When all was ready I shook hands with Lieutenant Clements, Mr. Maxwell Muller and other friends, accepted their best wishes for success, and composed myself in the rather crowded cockpit. The customary signal-word "Contact!" exchanged between pilot and mechanics, seemed, perhaps, to have a special momentary significance; but my impatience to take the plunge and be rid of anxiety about the start shut out all other impressions that might have been different from those experienced at the beginning of each of the thousand and one flights I had made before the transatlantic venture. First one and then the other motors came to life, swelled into a roar when Alcock ran them up and softened into a subdued murmur when he throttled back and warmed them up. Finally, everything being satisfactory, he disconnected the starting magneto and engine switches, to avoid stoppage due to possible short-circuits, and signaled for the chocks to be pulled clear. With throttles open and engines "all out," the Vickers-Vimy advanced into the westerly wind. The "take off," up a slight gradient, was very difficult. Gusts up to forty-five knots were registered, and there was insufficient room to begin the run dead into the wind. What I feared in particular was that a sudden eddy might lift the planes on one side and cause the machine to heel over. Another danger was the rough surface of the aërodrome. Owing to its heavy load, the machine did not leave the ground until it had lurched and lumbered, at an ever-increasing speed, over 300 yards. We were then almost at the end of the ground-tether allowed us. A line of hills straight ahead was responsible for much "bumpiness" in the atmosphere, and made climbing very difficult. At times the strong wind dropped almost to zero, then rose in eddying blasts. Once or twice our wheels nearly touched the ground again. Under these conditions we could climb but slowly, allowing for the danger of sudden upward gusts. Several times I held my breath, from fear that our undercarriage would hit a roof or a tree-top. I am convinced that only Alcock's clever piloting saved us from such an early disaster. When, after a period that seemed far longer than it actually was, we were well above the buildings and trees, I noticed that the perspiration of acute anxiety was running down his face. We wasted no time and fuel in circling round the aërodrome while attaining a preliminary height, but headed straight into the wind until we were at about eight hundred feet. Then we turned towards the sea and continued to rise leisurely, with engines throttled down. As we passed our aërodrome I leaned over the side of the machine and waved farewell to the small groups of mechanics and sightseers. The Vickers-Vimy, although loaded to the extent of about eleven pounds per square foot, climbed satisfactorily, if slowly. Eight minutes passed before we had reached the thousand feet level. As we passed over St. John's and Cabot's Hill towards Concepcion Bay the air was very bumpy, and not until we reached the coast and were away from the uneven contours of Newfoundland did it become calmer. The eddying wind, which was blowing behind us from almost due west, with a strength of thirty-five knots, made it harder than ever to keep the machine on a straight course. The twin-engine Vickers-Vimy is not especially sensitive to atmospheric instability; but under the then atmospheric conditions it lurched, swayed, and did its best to deviate, much as if it had been a little single-seater scout. We crossed the coast at 4:28 P. M. (Greenwich time), our aneroid then registering about twelve hundred feet. Just before we left the land I let out the wireless aërial, and tapped out on the transmitter key a message to Mount Pearl Naval Station: "All well and started." My mind merely recorded the fact that we were leaving Newfoundland behind us. Otherwise it was too tense with concentration on the task ahead to find room for any emotions or thoughts on seeing the last of the square-patterned roof-mosaic of St. John's, and of the tangled intricacy of Newfoundland's fields, woods and hills. Behind and below was America, far ahead and below was Europe, between the two were nearly two thousand miles of ocean. But at the time I made no such stirring, if obvious, reflections; for my navigation instruments and charts, as applied to sun, horizon, sea-surface and time of day, demanded close and undivided attention. Withal, I felt a queer but quite definite confidence in our safe arrival over the Irish coast, based, I suppose, on an assured knowledge that the machine, the motors, the navigating instruments and the pilot were all first-class. The Vickers-Vimy shook itself free from the atmospheric disturbances over the land, and settled into an even stride through the calmer spaces above the ocean. The westerly wind behind us, added to the power developed by the motors, gave us a speed along our course (as opposed to "air-speed") of nearly one hundred and forty knots. Visibility was fairly good during the first hour of the flight. Above, at a height of something between two and three thousand feet, a wide ceiling of clouds was made jagged at fairly frequent intervals by holes through which the blue sky could be glimpsed. Below, the sea was blue-gray, dull for the most part but bright in occasional patches, where the sunlight streamed on it through some cloud-gap. Icebergs stood out prominently from the surface, in splashes of glaring white. I was using all my faculties in setting and keeping to the prescribed course. The Baker navigating machine, with the chart, was on my knees. Not knowing what kind of weather was before us, I knelt on my seat and made haste to take observations on the sea, the horizon, and the sun, through intervals in the covering of clouds. The navigation of aircraft, in its present stage, is distinctly more difficult than the navigation of seacraft. The speed at which they travel and the influence of the wind introduce problems which are not easily solved. A ship's navigator knows to a small fraction of a mile the set of any ocean current, and from the known speed of his vessel he can keep "dead reckoning" with an accuracy that is nearly absolute. In fact, navigators have taken their craft across the Atlantic without once having seen the sun or stars, and yet, at the end of the journey, been within five miles of the desired destination. But in the air the currents either cannot be, or have not yet been, charted, and his allowance for the drift resulting from them must be obtained by direct observation on the surface of the ocean. By the same means his actual speed over the ocean may be calculated. He finds the position of his craft by measuring the angle which either the sun or a selected star makes with the horizon, and noting the Greenwich mean time at which the observation is made. If the bearings of two distinct wireless stations can be taken, it is also possible to find his definite position by means of directional wireless telegraphy. When making my plans for the transatlantic flight I considered very carefully all the possibilities, and decided to rely solely upon observations of the sun and stars and upon "dead reckoning," in preference to using directional wireless, as I was uncertain at that time whether or not the directional wireless system was sufficiently reliable. My sextant was of the ordinary marine type, but it had a more heavily engraved scale than is usual, so as to make easier the reading of it amid the vibration of the aëroplane. My main chart was on the Mercator projection, and I had a special transparent chart which could be moved above it, and upon which were drawn the Sumner circles for all times of the day. I carried a similar special chart for use at night, giving the Sumner circles for six chosen stars. To measure the drift I had a six-inch Drift-Bearing plate, which also permitted me to measure the ground speed, with the help of a stopwatch. In addition, I had an Appleyard Course and Distance Calculator, and Traverse tables for the calculation of "dead reckoning." [Illustration: IT WAS HARD TO FIND AN AËRODROME WITH SUFFICIENT "TAKE OFF"] [Illustration: SIGHTSEERS, IF LEFT TO THEMSELVES, WOULD HAVE WRECKED THE MACHINE] As the horizon is often obscured by clouds or mist, making impossible the measurement of its angle with the heavenly bodies, I had a special type of spirit level, on which the horizon was replaced by a bubble. This, of course, was less reliable than a true horizon since the bubble was affected by variations of speed; but it was at least a safeguard. Taking into account the general obscurity of the atmosphere during most of the flight, it was fortunate that I took such a precaution, for I seldom caught sight of a clearly defined horizon. I could legitimately congratulate myself on having collected as many early observations as possible while the conditions were good; for soon we ran into an immense bank of fog, which shut off completely the surface of the ocean. The blue of the sea merged into a hazy purple, and then into the dullest kind of gray. The cloud screen above us, also, grew much thicker, and there were no more gaps in it. The occasional sun-glints on wing-tips and struts no longer appeared. Thus I could obtain neither observations on the sun, nor calculations of drift from the seas. Assuming that my first observations were satisfactory, I therefore carried on by "dead reckoning," and hoped for the best. From time to time I varied the course slightly, so as to allow for the different variations of the compass. Meantime, while we flew through the wide layer of air sandwiched between fog and cloud, I began to jot down remarks for the log of the journey. At 5:20 I noted that we were at fifteen hundred feet and still climbing slowly, while the haze was becoming ever thicker and heavier. I leaned towards the wireless transmitter, and began to send a message; but the small propeller on it snapped, and broke away from the generator. Careful examination, both at the time and after we landed, showed no defect; and I am still unable to account for the fracture. Although I was too occupied with calculations to pay much attention to moods or passing thoughts, I remember feeling that this cutting off of all means of communication with the life below and behind us gave a certain sense of finality to the adventure. We continued eastward, with the rhythmic drone of the motors unnoted in supreme concentration on the tense hours that were to come. CHAPTER IV EVENING For a time Alcock and I attempted short conversations through the telephone. Its earpieces were under our fur caps, and round our necks were sensitive receivers for transmitting the throat vibrations that accompany speech. At about six o'clock Alcock discarded his earpieces because they were too painful; and for the rest of the flight we communicated in gestures and by scribbled notes. I continued to keep the course by "dead reckoning," taking into account height, compass bearing, strength of wind, and my previous observations. The wind varied quite a lot, and several times the nose of the Vickers-Vimy swayed from the right direction, so that I had to make rapid mental allowances for deviation. The results I made known to Alcock by passing over slips of paper torn from my notebook. The first of these was the direction: "_Keep her nearer 120 than 140._" The second supplied the news that the transmitter was useless: "_Wireless generator smashed. The propeller has gone._" Throughout the evening we flew between a covering of unbroken cloud and a screen of thick fog, which shut off the sea completely. My scribbled comment to the pilot at 5:45 was: "_I can't get an obs. in this fog. Will estimate that same wind holds and work by dead reckoning._" Despite the lack of external guidance, the early evening was by no means dull. Just after six the starboard engine startled us with a loud, rhythmic chattering, rather like the noise of machine-gun fire at close quarters. With a momentary thought of the engine trouble which had caused Hawker and Grieve to descend in mid-Atlantic, we both looked anxiously for the defect. This was not hard to find. A chunk of exhaust pipe had split away, and was quivering before the rush of air like a reed in an organ pipe. It became first red, then white-hot; and, softened by the heat, it gradually crumpled up. Finally it was blown away, with the result that three cylinders were exhausting straight into the air, without guidance through the usual outlet. The chattering swelled into a loud, jerky thrum, much more prominent than the normal noise of a Rolls-Royce aëro-engine. This settled down to a steady and continuous roar. Until we landed nothing could be done to the broken exhaust pipe, and we had to accept it as a minor disaster, unpleasant but irremediable. Very soon my ears had become so accustomed to the added clamor that it passed unnoticed. I must admit, however, that although my mind contained no room for impressions dealing with incidents not of vital importance, I was far from comfortable when I first observed that a little flame, licking outward from the open exhaust, was playing on one of the cross-bracing wires and had made it red-hot. This trouble could not be lessened by throttling down the starboard engine, as in that case we should have lost valuable height. The insistent hum of the engines, in fact, made the solitude seem more normal. The long flight would have been dreadful had we made it in silence; for, shut off as we were from sea and sky, it was a very lonely affair. At this stage the spreading fog enveloped the Vickers-Vimy so closely that our sheltered cockpit suggested an isolated but by no means cheerless room. Moisture condensed on goggles, dial glasses and wires when, at about seven, we rose through a layer of clouds on the two thousand foot level. Alcock wore no goggles, by the way, and I made use of mine only when leaning over the side of the fuselage to take observations. Emerging into the air above the clouds, I looked upward, and found another stretch of cloud-bank still higher, at five thousand feet. We thus remained cut off from the sun. Still guided only by "dead reckoning," the Vickers-Vimy continued along the airway between a white cloud-ceiling and a white cloud-carpet. I was very anxious for an opportunity to take further observations either of the sun or of the stars, so as to check the direction by finding our correct position. At 7:40 I handed Alcock the following note: "_If you get above clouds we will get a good fix[1] to-night, and hope for clear weather to-morrow. Not at any risky expense to engines though. We have four hours yet to climb._" The altimeter was then registering three thousand feet. All this while I had listened occasionally for wireless messages, as the receiver was still in working order. No message came for us, however, and the only sign of life was when, at 7:40, I heard somebody calling "B. M. K." Even that small sign of contact with life below cheered me mightily. Throughout the journey we had no regular meals, but ate and drank in snatches, whenever we felt so inclined. It was curious that neither of us felt hungry at any time during the sixteen hours of the flight, although now and then I felt the need of something to drink. The food was packed into a little cupboard behind my head, on the left-hand side of the fuselage. I reached for it at about 7:30, and, deciding that Alcock must need nourishment, I passed him two sandwiches and some chocolate, and uncorked the thermos flask. He made use of only one hand for eating and drinking, keeping the other on the control lever. We happened upon a large gap in the upper layer of clouds at 8:30. Through it the sun shone pleasantly, projecting the shadow of the Vickers-Vimy on to the lower layer, over which it darted and twisted, contracting or expanding according to the distortions on the cloud-surface. I was able to maintain observation on the sun for some ten minutes. The calculations thus obtained showed that if we were still on the right course the machine must be farther east than was indicated by "dead reckoning." From this I deduced that the strength of the wind must have increased rather than fallen off, as had been prophesied in the report of the meteorological expert at St. John's. This supposition was borne out by the buffetings which, from time to time, swayed the Vickers-Vimy. Up till then our average speed had been one hundred and forty-three knots. I got my observations of the sun while kneeling on the seat and looking between the port wings. I made use of the spirit level, as the horizon was invisible and the sextant could therefore not be used. Later, I caught sight of the sea for a few brief moments, and at 9:15 I wrote the following note to Alcock: "_Through a rather bad patch I have just made our ground speed 140 knots, and from the sun's altitude we must be much further east and south than I calculated._" I continued to keep a log of our movements and observations, and at 9:20 P. M. made the following entry: "_Height 4,000 feet. Dense clouds below and above. Got one sun observation, which shows that dead reckoning is badly out. Shall wait for stars and climb. At 8:31 position about 49 deg. 31 minutes north, 38 deg. 35 minutes west._" The clouds above remained constant, at a height of about five thousand feet. I was eager to pass through them before the stars appeared; and at nine-thirty, when the light was fading, I scribbled the inquiry: "_Can you get above these clouds at, say, 60°? We must get stars as soon as poss._" Alcock nodded, and proceeded to climb as steeply as he dared. Twilight was now setting in, gradually but noticeably. Between the layers of cloud the daylight, although never very good, had until then been strong enough to let me read the instruments and chart. At ten o'clock this was impossible without artificial light. For my chart I now used an electric lamp. I switched on a tiny bulb which was placed so as to make the face of the compass clear in the dark, all the other fixed instruments being luminous in themselves. For my intermittent inspection of the engines I had to flash the electric torch over either side of the cockpit. The clouds, both above and below, grew denser and darker. One could see them only as indefinite masses of nebulousness, and it became more and more difficult to judge how near to or how far from them we were. An entry in my log, made at 10:20, says, "_No observations, and dead reckoning apparently out. Could not get above clouds for sunset. Will wait check by stars._" An hour later we had climbed to five thousand two hundred feet. But still we found clouds above us; and we continued to rise, so as to be above them in time for some early observations on the stars. It was now quite dark; and as we droned our isolated way eastward and upward, nothing could be seen outside the cockpit, except the inner struts, the engines, the red-glowing vapor ejected through the exhaust pipes, and portions of the wings, which glistened in the dim moonglimmer. I waited impatiently for the first sight of the moon, the Pole Star, and other night-time friends of every navigator. [Footnote 1: Position.] CHAPTER V NIGHT Midnight came and went amid sullen darkness, modified only by dim moonlight and the red radiance that spurted from the motors' exhaust pipes. By then we must have climbed to about six thousand feet, although my log shows no record of our height at this stage. Meanwhile, we were still between upper and lower ranges of cloud banks. At a quarter past twelve Alcock took the Vickers-Vimy through the upper range, only to find a third layer of clouds, several thousand feet higher. This, however, was patchy and without continuity, so that I was able to glimpse the stars from time to time. At 12:25 I identified through a gap to north-eastward Vega, which shone very brightly high in the heavens, and the Pole Star. With their help, and that of a cloud horizon that was clearly defined in the moonlight, not far below our level, I used the sextant to fix our position. This I found was latitude 50° 7´ N. and longitude 31° W., showing that we had flown 850 nautical miles, at an average speed of 106 knots. We were slightly to the south of the correct course, which fact I made known to Alcock in a note, with penciled corrections for remedying the deviation. Most of my "dead reckoning" calculations were short of our actual position because, influenced by meteorological predictions based on the weather reports at St. John's, I had allowed for a falling off in the strength of the wind, and this had not occurred. Having found the stars and checked our position and direction, the urgent necessity to continue climbing no longer existed. Alcock had been nursing his engines very carefully, and to reduce the strain on them he let the machine lose height slowly. At 1:20 A. M. we were down to four thousand feet, and an hour later we had dropped yet four hundred feet lower. [Illustration: THE TRANSATLANTIC MACHINE--A VICKERS-VIMY WITH ROLLS-ROYCE ENGINES] The clouds overhead were still patchy, clusters of stars lightening the intervals between them. But the Vickers-Vimy, at its then height, was moving through a sea of fog, which prevented effective observation. This I made known to the pilot in a message: "_Can get no good readings. Observation too indefinite._" The moon was in evidence for about an hour and a half, radiating a misty glow over the semi-darkness and tinging the cloud-tips with variations of silver, gold and soft red. Whenever directly visible it threw the moving shadows of the Vickers-Vimy on to the clouds below. Mostly I could see the moon by looking over the machine's starboard planes. I tried to sight on it for latitude, but the horizon was still too indefinite. An aura of unreality seemed to surround us as we flew onward towards the dawn and Ireland. The fantastic surroundings impinged on my alert consciousness as something extravagantly abnormal--the distorted ball of a moon, the weird half-light, the monstrous cloud-shapes, the fog below and around us, the misty indefiniteness of space, the changeless drone, drone, drone of the motors. To take my mind from the strangeness of it all, I turned to the small food-cupboard at the back of the cockpit. Twice during the night we drank and ate in snatches, Alcock keeping a hand on the joystick while using his other to take the sandwiches, chocolate and thermos flask, which I passed to him one at a time. Outside the cockpit was bitter cold, but inside was well-sheltered warmth, due to the protective windscreen, the nearness of the radiator, and our thick clothing. Almost our only physical discomfort resulted from the impossibility of any but cramped movements. It was a relief even to turn from one motor to the other, when examining them by the light of my electric torch. After several hours in the confined quarters, I wanted to kick out, to walk, to stretch myself. For Alcock, who never removed his feet from the rudder-bars, the feeling of restiveness must have been painfully uncomfortable. It was extraordinary that during the sixteen hours of the flight neither Alcock nor I felt the least desire for sleep. During the war, pilots and observers of night-bombing craft, their job completed, often suffered intensely on the homeward journey, from the effort of will necessary to fight the drowsiness induced by relaxed tension and the monotonous, never-varying hum of the motor--and this after only four to six hours of continuous flying. Probably, however, such tiredness was mostly reaction and mental slackening after the object of their journeys--the bombing of a target--had been achieved. Our own object would not be achieved until we saw Ireland beneath us; and it could not be achieved unless we kept our every faculty concentrated on it all the time. There was therefore no mental reaction during our long period of wakeful flying over the ocean. We began to think about sunrise and the new day. We had been flying for over ten hours; and the next ten would bring success or failure. We had more than enough petrol to complete the long journey, for Alcock had treated the engines very gently, never running them all out, but varying the power from half to three-quarter throttle. Our course seemed satisfactory, and the idea of failure was concerned only with the chance of engine mishap, such as had befallen Hawker and Grieve, or of something entirely unforeseen. Something entirely unforeseen did happen. At about sunrise--3:10 A. M. to be exact--when we were between thirty-five hundred and four thousand feet, we ran into a thick bank that projected above the lower layer of cloud. All around was dense, drifting vapor, which cut off from our range of vision even the machine's wing tips and the fore end of the fuselages. This was entirely unexpected; and, separated suddenly from external guidance, we lost our instinct of balance. The machine, left to its own devices, swung, flew amok, and began to perform circus tricks. Until we should see either the horizon or the sky or the sea, and thus restore our sense of the horizontal, we could tell only by the instruments what was happening to the Vickers-Vimy. Unless there be outside guidance, the effect on the Augean canal in one's ears of the centrifugal force developed by a turn in a cloud causes a complete loss of dimensional equilibrium, so that one is inclined to think that an aëroplane is level even when it is at a big angle with the horizontal. The horizontal, in fact, seems to be inside the machine. A glance at the instruments on the dashboard facing us made it obvious that we were not flying level. The air speed crept up to ninety knots, while Alcock was trying to restore equilibrium. He pulled back the control lever; but apparently the air speed meter was jammed, for although the Vickers-Vimy must have nosed upwards, the reading remained at ninety. And then we stalled--that is to say our speed dropped below the minimum necessary for heavier-than-air flight. The machine hung motionless for a second, after which it heeled over and fell into what was either a spinning nosedive, or a very steep spiral. The compass needle continued to revolve rapidly, showing that the machine was swinging as it dropped; but, still hemmed in as we were by the thick vapor, we could not tell how, or in which direction we were spinning. Before the pilot could reduce the throttle, the roar of the motors had almost doubled in volume, and instead of the usual 1650 to 1700 revolutions per minute, they were running at about 2200 revolutions per minute. Alcock shut off the throttles, and the vibration ceased. Apart from the changing levels marked by the aneroid, only the fact that our bodies were pressed tightly against the seats indicated that the machine was falling. How and at what angle it was falling, we knew not. Alcock tried to centralize the controls, but failed because we had lost all sense of what was central. I searched in every direction for an external sign, and saw nothing but opaque nebulousness. The aneroid, meantime, continued to register a height that dropped ever lower and alarmingly lower--three thousand, two thousand, one thousand, five hundred feet. I realized the possibility that we might hit the ocean at any moment, if the aneroid's exactitude had been affected by differences between the barometric conditions of our present position and those of St. John's, where the instrument was set. A more likely danger was that our cloud might stretch down to the surface of the ocean; in which case Alcock, having obtained no sight of the horizon, would be unable to counteract the spin in time. I made ready for the worst, loosening my safety belt and preparing to salve my notes of the flight. All precautions would probably have been unavailing, however, for had we fallen into the sea, there would have been small hope of survival. We were on a steep slant, and even had we escaped drowning when first submerged, the dice would be heavily loaded against the chance of rescue by a passing ship. And then while these thoughts were chasing each other across my mind, we left the cloud as suddenly as we had entered it. We were now less than a hundred feet from the ocean. The sea-surface did not appear below the machine, but, owing to the wide angle at which we were tilted against the horizontal, seemed to stand up level, sideways to us. Alcock looked at the ocean and the horizon, and almost instantaneously regained his mental equilibrium in relation to external balance. Fortunately the Vickers-Vimy maneuvers quickly, and it responded rapidly to Alcock's action in centralizing the control lever and rudder bar. He opened up the throttles. The motors came back to life, and the danger was past. Once again disaster had been averted by the pilot's level-headedness and skill. When at last the machine swung back to the level and flew parallel with the Atlantic, our height was fifty feet. It appeared as if we could stretch downward and almost touch the great white-caps that crested the surface. With the motors shut off we could actually _hear_ the voice of the cheated ocean as its waves swelled, broke, and swelled again. The compass needle, which had continued to swing, now stabilized itself and quivered toward the west, showing that the end of the spin left us facing America. As we did not want to return to St. John's, and earnestly wanted to reach Ireland, Alcock turned the machine in a wide semi-circle and headed eastward, while climbing away from the ocean and towards the lowest clouds. CHAPTER VI MORNING Sunrise made itself known to us merely as a gradual lightening that showed nothing but clouds, above and below. The sun itself was nowhere visible. We seemed to be flying in and out of dense patches of cloud; for every now and then we would pass through a white mountain, emerge into a small area of clear atmosphere, and then be confronted with another enormous barrier of nebulousness. The indefiniteness of dawn disappointed my hopes of taking observations. Already at three o'clock I had scribbled a note to the pilot: "_Immediately you see sun rising, point machine straight towards it, and we'll get compass bearings._" I had already worked out a table of hours, angles and azimuths of the sun at its rising, to serve as a check upon our position; but, as things happened, I was obliged to resume navigation by means of "dead reckoning." A remark written in my log at twenty minutes past four was that the Vickers-Vimy had climbed to six thousand five hundred feet, and was above the lower range of clouds. For the rest, the three hours that followed sunrise I remember chiefly as a period of envelopment by clouds, and ever more clouds. Soon, as we continued to climb, the machine was traveling through a mist of uniform thickness that completely shut off from our range of vision everything outside a radius of a few yards from the wing-tips. And then came a spell of bad weather, beginning with heavy rain, and continuing with snow. The downpour seemed to meet us almost horizontally, owing to the high speed of the machine, as compared with the rate of only a few feet per second at which the rain and snow fell. The snow gave place to hail, mingled with sleet. The sheltered position of the cockpit, and the stream-lining of the machine, kept us free from the downfall so long as we remained seated; but if we exposed a hand or a face above the windscreen's protection, it would meet scores of tingling stabs from the hailstones. When we had reached a height of eight thousand eight hundred feet, I discovered that the glass face of the gasoline overflow gauge, which showed whether or not the supply of fuel for the motors was correct, had become obscured by clotted snow. To guard against carburetor trouble, it was essential that the pilot should be able to read the gauge at any moment. It was up to me, therefore, to clear away the snow from the glass. The gauge was fixed on one of the center section struts. The only way to reach it was by climbing out of the cockpit and kneeling on top of the fuselage, while holding on to a strut for balance. This I did; and the unpleasant change from the comparative warmth of the cockpit to the biting, icy cold outside was very unpleasant. The violent rush of displaced air, which tended to sweep me backward, was another discomfort. I had no difficulty, however, in reaching upward and rubbing the snow from the face of the gauge. Until the storm ended, a repetition of this performance at fairly frequent intervals continued to be necessary. There was, however, scarcely any danger in kneeling on the fuselage as long as Alcock kept the machine level. Every now and then we examined the motors; for on them depended whether the next four hours would bring success or failure. Meantime, we were still living for the moment; and although I was intensely glad that four-fifths of the ocean had been crossed, I could afford to spare no time for speculation on what a safe arrival would mean to us. As yet, neither of us was aware of the least sign of weariness, mental or physical. When I had nothing more urgent on hand, I listened at the wireless receiver but I heard no message for us from beginning to end of the flight. Any kind of communication with ship or shore would have been welcome, as a reminder that we were not altogether out of touch with the world below. The complete absence of such contact made it seem that nobody cared a darn about us. The entry that I scribbled in my log at 6:20 A. M. was that we had reached a height of nine thousand four hundred feet, and were still in drifting cloud, which was sometimes so thick that it cut off from view parts of the Vickers-Vimy. Snow was still falling, and the top sides of the plane were covered completely by a crusting of frozen sleet. The sleet imbedded itself in the hinges of the ailerons and jammed them, so that for about an hour the machine had scarcely any lateral control. Fortunately the Vickers-Vimy has plenty of inherent lateral stability; and, as the rudder controls were never clogged by sleet, we were able to carry on with caution. Alcock continued to climb steadily, so as to get above the seemingly interminable clouds and let me have a clear sky for purposes of navigation. At five o'clock, when we were in the levels round about eleven thousand feet, I caught the sun for a moment--just a pin-point glimmer through a cloud-gap. There was no horizon; but I was able to obtain a reading with the help of my Abney spirit level. This observation gave us a position close to the Irish coast. Yet I could not be sure of just where we were on the line indicated by it. We therefore remained at eleven thousand feet until, at 7:20 A. M., I had definitely fixed the position line. This accomplished, I scribbled the following message and handed it across to the pilot: "_We had better go lower down, where the air is warmer, and where we might pick up a steamer._" Just as we had started to nose downward, the starboard motor began to pop ominously, as if it were backfiring through one of its carburetors. Alcock throttled back while keeping the machine on a slow glide. The popping thereupon ceased. By eight o'clock we had descended from eleven thousand to one thousand feet, where the machine was still surrounded by cloudy vapor. Here, however, the atmosphere was much warmer, and the ailerons were again operating. Alcock was feeling his way down gently and alertly, not knowing whether the cloud extended to the ocean, nor at what moment the machine's undercarriage might touch the waves. He had loosened his safety belt, and was ready to abandon ship if we hit the water. I myself felt uncomfortable about the danger of sudden immersion, for it was very possible that a change in barometric conditions could have made the aneroid show a false reading. [Illustration: A SPECIAL KIND OF GASOLINE HAD TO BE USED] [Illustration: ALL ABOARD FOR THE FIRST TRIAL FLIGHT] But once again we were lucky. At a height of five hundred feet the Vickers-Vimy emerged from the pall of cloud, and we saw the ocean--a restless surface of dull gray. Alcock at once opened up the throttles, and both motors responded. Evidently a short rest had been all that the starboard motor needed when it began to pop, for it now gave no further signs of trouble. I reached for the Drift Bearing Plate, and after observation on the ocean, found that we were moving on a course seventy-five degrees true, at one hundred and ten knots ground speed with a wind of thirty knots from the direction of two hundred and fifteen degrees true. I had been reckoning on a course of seventy-seven degrees true, with calculations based on our midnight position; so that evidently we were north of the prescribed track. Still, we were not so far north as to miss Ireland, which fact was all that mattered to any extent. In my correction of the compass bearing, I could only guess at the time when the wind had veered from its earlier direction. I made the assumption that the northerly drift had existed ever since my sighting on the Pole Star and Vega during the night, and I reckoned that our position at eight o'clock would consequently be about fifty-four degrees N. latitude, ten degrees thirty min. W. longitude. Taking these figures, and with the help of the navigation machine, which rested on my knees, I calculated that our course to Galway was about one hundred and twenty-five degrees true. Allowing for variation and wind I therefore set a compass course of one hundred and seventy degrees, and indicated to the pilot the necessary change in direction by means of the following note and diagram: [Illustration: "_Make course_ "_Don't be afraid of going S. We have had too much N. already._"] Alcock nodded and ruddered the Vickers-Vimy around gently, until its compass showed a reading of 170 degrees. My calculations, if correct, proved that we were quite close to Ireland and journey's end. As we flew eastward, just below the lowest clouds and from two hundred to three hundred feet above the sea, we strained our eyes for a break in the monotonous vista of gray waves; but we could find not even a ship. Although neither of us felt hungry, we decided to breakfast at eight o'clock, partly to kill time and partly to take our minds from the rising excitement induced by the hope that we might sight land at any instant. I placed a sandwich, followed by some chocolate, in Alcock's left hand. His right hand remained always on the control lever and his feet on the rudder bar. At no time during the past sixteen hours had the pilot's hands and feet left the controls. This was a difficult achievement for such a long period, especially as a rubber device, fitted to ease the strain, proved to be valueless. Elastic, linked to a turnbuckle, had been attached to the control lever and rudder bar; but in the hurry that preceded our departure from St. John's, the elastic was cut too short. All the weight of the controls, therefore, bore directly on the pilot. The machine now tended to sag downward, being nose-heavy because its incidence had changed, owing to the gradual alteration in the center of gravity as the rear gasoline tanks emptied. Alcock was thus obliged to exert continuous backward pressure on the control lever. I had screwed on the lids of the thermos flask, and was placing the remains of the food in the tiny cupboard behind my seat, when Alcock grabbed my shoulder, twisted me round, beamed excitedly, and pointed ahead and below. His lips were moving, but whatever he said was inaudible above the roar of the motors. I followed the direction indicated by his outstretched fore-finger; and, barely visible through the mist, it showed me two tiny specks of--_land_. This happened at 8:15 A. M. on June 15th. With a light heart, I put away charts and tables of calculation, and disregarded the compass needle. My work as navigator of the flight was at an end. CHAPTER VII THE ARRIVAL Alcock flew straight for the specks of land, which revealed themselves as two tiny islands--Ecshal and Turbot, as we afterwards discovered. In his log of the return flight, from New York to Norfolk, of the British airship _R-34_, Brigadier-General Maitland, C. M. G., D. S. O., notes the curious coincidence that his first sight of land was when these same two islands appeared on the starboard bow of the dirigible. From above the islands the mainland was visible, and we steered for the nearest point on it. The machine was still just underneath the clouds, and flying at two hundred and fifty feet; from which low height I saw plainly the white breakers foaming on to the shore. We crossed the coast of Ireland at 8:25 A. M. I was then uncertain of our exact location, and suggested to Alcock that the best plan would be to find a railway line and follow it south. A few minutes later, however, the wireless masts at Clifden gave the key to our position. To attract attention, I fired two red flares from the Very pistol; but as they seemed to be unnoticed from the ground, we circled over the village of Clifden, about two miles from the wireless station. Although slightly off our course when we reached the coast, we were in the direct line of flight for Galway, at which place I had calculated to hit Ireland. Not far ahead we could see a cluster of hills, with their tops lost in low-lying clouds. Here and elsewhere the danger of running into high ground hidden from sight by the mist would have been great, had we continued to fly across Ireland. Alcock, therefore, decided to land. If the atmosphere had been clearer, we could easily have reached London before touching earth, for the tanks of the Vickers-Vimy still contained enough gasoline to keep the machine in the air for ten hours longer. Thus, had we lost our way over the ocean, there would have been a useful margin of time for cruising about in search of ships. Having made up our minds to land at once, we searched below for a smooth stretch of ground. The most likely looking place in the neighborhood of Clifden was a field near the wireless station. With engines shut off, we glided towards it, heading into the wind. Alcock flattened out at exactly the right moment. The machine sank gently, the wheels touched earth and began to run smoothly over the surface. Already I was indulging in the comforting reflection that the anxious flight had ended with a perfect landing. Then, so softly as not to be noticed at first, the front of the Vickers-Vimy tilted inexplicably, while the tail rose. Suddenly the craft stopped with an unpleasant squelch, tipped forward, shook itself, and remained poised on a slant, with its fore-end buried in the ground, as if trying to stand on its head. I reached out a hand and arm just in time to save a nasty bump when the shock threw me forward. As it was, I only stopped a jarring collision with the help of my nose. Alcock had braced himself against the rudder control bar. The pressure he exerted against it to save himself from falling actually bent the straight bar, which was of hollow steel, almost into the shape of a horse-shoe. Deceived by its smooth appearance, we had landed on top of a bog; which misfortune made the first non-stop transatlantic flight finish in a crash. It was pitiful to see the distorted shape of the aëroplane that had brought us from America, as it sprawled in ungainly manner over the sucking surface. The machine's nose and its lower wings were deep in the bog. The empty cockpit in front, used in a Vickers-Vimy bomber by the observer, was badly bent; but, being of steel, it did not collapse. Quite possibly we owe our lives to this fact. In passing, and while gripping firmly my wooden penholder (for the year is not yet over), I consider it extraordinary that no lives have been lost in the transatlantic flights of 1919. The leading edge of the lower plane was bent in some places and smashed in others, the gasoline connections had snapped, and four of the propeller blades were buried in the ground, although none were broken. That about completed the record of preliminary damage. We had landed at 8:40 A. M., after being in the air for sixteen hours and twenty-eight minutes. The flight from coast to coast, on a straight course of one thousand six hundred and eighty nautical miles, lasted only fifteen hours and fifty-seven minutes, our average speed being one hundred and five to one hundred and six knots. For this relatively rapid performance, a strong following wind was largely responsible. As a result of the burst connections from tank to carburetor, gasoline began to swill into the rear cockpit while we were still inside it. Very fortunately the liquid did not ignite. Alcock had taken care to switch off the current on the magnetos, as soon as he realized that a crash was imminent, so that the sparks should have no chance of starting a fire. We scrambled out as best we could, and lost no time in salving the mailbag and our instruments. The gasoline rose rapidly, and it was impossible to withdraw my chart and the Baker navigating machine before they had been damaged. I then fired two white Very flares, as a signal for help. Almost immediately a small party, composed of officers and men belonging to the military detachment at Clifden, approached from the wireless station. "Anybody hurt?"--the usual inquiry when an aëroplane is crashed--was the first remark when they arrived within shouting distance. "No." "Where you from?"--this when they had helped us to clear the cockpit. "America." Somebody laughed politely, as if in answer to an attempt at facetiousness that did not amount to much, but that ought to be taken notice of, anyhow, for the sake of courtesy. Quite evidently nobody received the statement seriously at first. Even a mention of our names meant nothing to them, and they remained unconvinced until Alcock showed them the mail-bag from St. John's. Then they relieved their surprised feelings by spontaneous cheers and painful hand-shakes, and led us to the officers' mess for congratulations and hospitality. Burdened as we were with flying kit and heavy boots, the walk over the bog was a dragging discomfort. In addition, I suddenly discovered an intense sleepiness, and could easily have let myself lose consciousness while standing upright. Arrived at the station, our first act was to send telegrams to the firm of Messrs. Vickers, Ltd., which built the Vickers-Vimy, to the London _Daily Mail_, which promoted the transatlantic competition, and to the Royal Aëro Club, which controlled it. My memories of that day are dim and incomplete. I felt a keen sense of relief at being on land again; but this was coupled with a certain amount of dragging reaction from the tense mental concentration during the flight, so that my mind sagged. I was very sleepy, but not physically tired. We lurched as we walked, owing to the stiffness that resulted from our having sat in the tiny cockpit for seventeen hours. Alcock, who during the whole period had kept his feet on the rudder bar and one hand on the control lever, would not confess to anything worse than a desire to stand up for the rest of his life--or at least until he could sit down painlessly. My hands were very unsteady. My mind was quite clear on matters pertaining to the flight, but hazy on extraneous subjects. After having listened so long to the loud-voiced hum of the Rolls-Royce motors, made louder than ever by the broken exhaust pipe on the starboard side, we were both very deaf, and our ears would not stop ringing. Later in the day we motored to Galway with a representative of the London _Daily Mail_. It was a strange but very welcome change to see solid objects flashing past us, instead of miles upon monotonous miles of drifting, cloudy vapor. Several times during that drive I lost the thread of connection with tangible surroundings, and lived again in near retrospect the fantastic happenings of the day, night and morning that had just passed. Subconsciously I still missed the rhythmic, relentless drone of the Rolls-Royce aëro-engines. My eyes had not yet become accustomed to the absence of clouds around and below, and my mind felt somehow lost, now that it was no longer preoccupied with heavenly bodies, horizon, time, direction, charts, drift, tables of calculations, sextant, spirit level, compass, aneroid, altimeter, wireless receiver and the unexpected. For a while, in fact, the immediate past seemed more prominent than the immediate present. Lassitude of mind, coupled with reaction from the long strain of tense and unbroken concentration on one supreme objective, made me lose my grip of normal continuity, so that I answered questions mechanically and wanted to avoid the effort of talk. The outstanding events and impressions of the flight--for example the long spin from four thousand to fifty feet, and the sudden sight of the white-capped ocean at the end of it--passed and repassed across my consciousness. I do not know whether Alcock underwent the same mental processes, but he remained very silent. Above all I felt the need of reëstablishing normal balance by means of sleep. The wayside gatherings seemed especially unreal--almost as if they had been scenes on the film. By some extraordinary method of news transmission the report of our arrival had spread all over the district, and in many districts between Clifden and Galway curious crowds had gathered. Near Galway we were stopped by another automobile, in which was Major Mays of the Royal Aëro Club, whose duty it was to examine the seals on the Vickers-Vimy, thus making sure that we had not landed in Ireland in a machine other than that in which we left Newfoundland. A reception had been prepared at Galway; but our hosts, realizing how tired we must be, considerately made it a short and informal affair. Afterwards we slept--for the first time in over forty hours. CHAPTER VIII AFTERMATH OF ARRIVAL Alcock and I awoke to find ourselves in a wonderland of seeming unreality--the product of violent change from utter isolation during the long flight to unexpected contact with crowds of people interested in us. To begin with, getting up in the morning, after a satisfactory sleep of nine hours, was strange. In our eastward flight of two thousand miles we had overtaken time, in less than the period between one sunset and another, to the extent of three and a half hours. Our physical systems having accustomed themselves to habits regulated by the clocks of Newfoundland, we were reluctant to rise at 7 A. M.; for subconsciousness suggested that it was but 3:30 A. M. [Illustration: © Underwood & Underwood, N. Y. THE VICKERS-VIMY TRANSATLANTIC MACHINE IN THE AIR] [Illustration: THE LAST SQUARE MEAL IN AMERICA WAS EATEN NEAR THE WINGS OF THE MACHINE] This difficulty of adjustment to the sudden change in time lasted for several days. Probably it will be experienced by all passengers traveling on the rapid trans-ocean air services of the future--those who complete a westward journey becoming early risers without effort, those who land after an eastward flight becoming unconsciously lazy in the mornings, until the jolting effect of the dislocation wears off, and habit has accustomed itself to the new conditions. Then, after breakfast--eaten in an atmosphere of the deepest content--there began a succession of congratulatory ovations. For these we were totally unprepared; and with our relaxed minds, we could not easily adapt ourselves to the conditions attendant upon being magnets of the world's attentive curiosity. First came a reception from the town of Galway, involving many addresses and the presentation of a memento in the form of a Claddagh ring, which had historical connections with a landing on the coast of Ireland thereabouts by vessels of the Spanish Armada. The warm-hearted crowd that we found waiting at Galway Station both amazed and daunted us. We were grateful for their loud appreciation, but scarcely able to respond to it adequately. Flowers were offered, and we met the vanguard of the autograph hunters. We must have signed our names hundreds of times during the journey to Dublin--on books, cards, old envelopes and scraps of paper of every shape and every state of cleanliness. This we did wonderingly, not yet understanding why so many people should ask for our signatures, when three days earlier few people had heard of our names. The men, women and children that thronged every station on the way to Dublin seemed to place a far higher value on our success than we did ourselves. Until now, perhaps, we had been too self-centered to realize that other people might be particularly interested in a flight from America to England. We had finished the job we wanted to do, and could not comprehend why it should lead to fuss. Now, however, I know that the crowds saw more clearly than I did, and that their cheers were not for us personally, but for what they regarded as a manifestation of the spirit of adventure, the True Romance--call it what you will. For the moment this elusive ideal was suggested to them by the first non-stop journey by air across the Atlantic, which we had been fortunate enough to make. At one station, where a military band played our train in and out again, a wooden model of an aëroplane was presented to Alcock by a schoolboy. At Dublin, reached on the morning of Trinity Sunday, Alcock and I passed with difficulty through the welcoming crowds, and drove towards the Automobile Club in separate cars. In due course, I reached sanctuary; but where was Alcock? We waited and waited, and finally sent out scouts to search for him. They came back with the news that he had been kidnapped, and taken to Commons in Trinity College. Landing at Holyhead next morning, we were welcomed back to the shores of England by Mr. R. K. Pierson, designer of our Vickers-Vimy machine, by Captain Vickers, of the famous firm that built it, and by Mr. C. Johnson, of the Rolls-Royce Company that supplied our motors. Scenes all along the line to London were a magnified repetition of those from Galway to Dublin. Chester, Crewe, Rugby and other towns each sent its Mayor or another representative to the station. Aëroplanes escorted the train all the way to London. Again we could only play our part in a more or less dazed state of grateful wonder. Of the warm-hearted welcome of the people of London, I have confused recollections that include more receptions, more and larger crowds, more stormy greetings, and an exciting, pleasant drive to the Royal Aëro Club. Alcock delivered to the postal authorities the mail-bag from St. John's, with regrets that it had not been possible to fly direct to London with the letters. In the evening we separated, Alcock to see a big prize fight, I to visit my fiancée. Perhaps the welcome that we appreciated most was that given us next day when, at the Weybridge works of the Vickers Company, we were cheered and cheered by the men and girls who had built our transatlantic craft. We were glad indeed to be able to tell them and the designer of the machine that their handiwork had stood a difficult test magnificently, as had the Rolls-Royce engines. One of my most sincere reasons for satisfaction was that the late Mr. Albert Vickers, one of the founders of the great firm, regarded the flights as having maintained the Vickers tradition of efficiency, originality and good workmanship. That Lieutenant-Commander Read, U.S.N., who commanded the American flying boat _N. C. 4_ in its flight from America to England, had left London before our arrival was a cause of real regret. Both Alcock and I were anxious to meet him and his crew, so that we might compare our respective experiences of aërial navigation and of weather conditions over the Atlantic. The United States aviators who flew to Europe, and those that were so unlucky in coming to grief at the Azores, showed themselves to be real sportsmen; and without any exception, there was the best possible feeling between them and all the British aviators who made, or attempted to make, a non-stop journey from Newfoundland to Ireland. Although I am supremely glad to have had the opportunity of flying the Atlantic by aëroplane, afterthoughts on the risks and chances taken have convinced me that, while our own effort may have been useful as a pioneer demonstration, single or twin engine aircraft are altogether unsuitable for trans-ocean voyages. We were successful--yes. But a temporary failure of either of our motors (although this is unlikely when dealing with Rolls-Royce or other first-class aëro motors) would have meant certain disaster and likely death. Another vital drawback of the smaller machines is that so much space, and so much disposable lift, is needed for fuel that the number of persons on board must be limited to two, or in some cases three, and no freight can be taken. Yet another is that should the navigator of an aëroplane make an important error in calculation while flying over the ocean in fog or mist, an enforced descent into the water, after the limited quantity of fuel has been expended over a wrong course, is more than possible. In the present condition of practical aëronautics, the only heavier-than-air craft likely to be suitable for flying the Atlantic are the large flying boats now being built by various aircraft companies; and even they are limited as to size by certain definite formulæ. The development in the near future of long flights over the ocean would seem, therefore, to be confined to lighter-than-air craft. In this connection the two voyages across the Atlantic of the British government airship R-34, not long after Alcock and I had returned to London, was a big step towards the age of regular air service between Britain and America. With five motors the _R-34_ could carry on if one, or even two of them were out of action. In fact, on its return flight, one motor broke down beyond the possibility of immediate repair; although there were ample facilities and an ample crew for effecting immediate repairs in the air. Yet she completed her journey without difficulty. With a disposable lift of twenty-nine tons, the airship carried plenty of fuel for all contingencies, an adequate crew, and heavy wireless apparatus that could not have been fitted on the larger aëroplanes. Despite all this preliminary weight, a large collection of parcels, letters and newspapers were taken from America to England in record time. Had the weather conditions been at all suitable she could easily have brought the mail direct from New York to London by air. All honor to General Maitland, Major Scott and the other men who carried out this astonishing demonstration so early as July, 1919. Even vessels of the _R-34_ type, however, are quite unsuitable for regular traffic across the Atlantic. Much bigger craft will be needed if the available space and the disposable lift are to be sufficient for the carrying of freight or passengers on a commercial basis. Already the construction of airships two and a half and five times the size of the _R-34_, with approximate disposable lifts of one hundred and two hundred tons respectively, is projected. When such craft are accomplished facts, and when further progress has been made in solving weather and navigation problems, we may look for transatlantic flights on a commercial basis. CHAPTER IX THE NAVIGATION OF AIRCRAFT I do not claim to be an especial authority on the theory of navigation--indeed, it was as a prisoner of war that I first took up seriously the study of that science. But I believe that sustained and sufficient concentration can give a man what he wants; and on this assumption I decided to learn whatever might be learned about navigation as applied to aircraft. As yet, like most aspects of aëronautics, this is rather indefinite, although research and specially adapted instruments will probably make it as exact as marine navigation. Navigation is the means whereby the mariner or aviator ascertains his position on the surface of the earth, and determines the exact direction in which he must head his craft in order to reach its destination. The methods of navigation employed by mariners are the result of centuries of research and invention, but have not yet reached finality--witness the introduction within the last few years of the Gyroscopic Compass and the Directional Wireless Telegraph Apparatus, as well as of improved methods of calculation. In short journeys over land by aëroplane or airship the duties of a navigator are light, so long as he can see the ground and check his progress towards the objective by observation and a suitable map. But for long distance flights, especially over the ocean and under circumstances whereby the ground cannot be seen, the navigator of the air borrows much from the navigator of the sea. He makes modifications and additions, necessitated by the different conditions of keeping to a set course through the atmosphere and of keeping to a set course through the ocean but the principles underlying the two forms of navigation are identical. It is impossible to explain aërial navigation without seeming to paraphrase other writers on the subject. One of the simplest explanations of the science is that of Lieutenant Commander K. Mackenzie Grieve in "Our Atlantic Attempt," which he wrote in collaboration with Mr. Harry Hawker, his pilot, after their glorious attempt to win the London _Daily Mail's_ transatlantic competition. The chief differences between the navigation of aircraft and the navigation of seacraft are occasioned by: (a) The vastly greater speed of aircraft, necessitating more frequent observations and quicker methods of calculation. (b) The serious drift caused by the wind. This may take aircraft anything up to forty or more miles off the course in each hour's flying, according to the direction and strength of the wind. In cloudy weather, or at night, a change in the wind can alter the drift without the knowledge of the navigator. Hence, special precautions must be taken to observe the drift at all possible times. (c) The absence of need for extreme accuracy of navigation in the air, since a ten or even twenty mile error from the destination in a long journey is permissible. Another favorable point is that rocks, reefs and shoals need not be avoided. This permits the aërial navigator to use short cuts and approximations in calculation, which would be criminal in marine navigation. There are three methods of aërial navigation--"Dead Reckoning," Astronomical Observation, and Directional Wireless Telegraphy. None should be used alone; for although accuracy may be obtained with any single method, it is highly advisable to check each by means of the others. As in the case of marine navigation, a reliable compass, either of the magnetic or gyroscopic type, is essential for aërial navigation, as well as an accurate and reliable chronometer. Suitable charts must be provided, showing all parts of the route to be covered. When the magnetic compass is used, such charts should show the variation between True and Magnetic North at different points on the route. NAVIGATION BY "DEAD RECKONING" "Dead Reckoning" is the simplest method of navigation; and, under favorable conditions, it gives a high degree of accuracy. A minimum of observation is required, but careful calculation is essential. The "Dead Reckoning" position of an aëroplane or airship at any time is calculated from its known speed and direction over the surface of the earth or ocean, and its known course as indicated by the magnetic or gyroscopic compass. To determine the direction of movement of an aëroplane or airship, as apart from the direction in which it is headed, an instrument known as a Drift Indicator, or Drift Bearing Plate, is used. One form of Drift Indicator consists of a simple dial, with the center cut away and a wire stretched diametrically across it. The outer edge of the dial is divided into degrees, in a similar manner to that of the compass. It is mounted in such a way that an observer can, by looking through the center of the disc, see the ground or ocean below him. The disc is then turned until objects on the ground--or white-caps, icebergs, ships, or other objects visible on the surface of the ocean--are seen to move parallel with the wire, without in any way deviating from it. The angle which the wire then makes with the direction in which the nose of the aëroplane or airship is pointing gives the angle of drift. The ground speed (or speed over the surface of the earth) of aircraft can be measured by observing the time taken in passing over any fixed or very slowly moving object, while a certain angular distance is described--this being found by suitable sights, attached to the Drift Bearing Plate. From the result, considered in conjunction with the height of the aëroplane or airship, the actual speed over the surface is calculated. This speed will be in the direction shown by the wire of the Drift Bearing Plate. The ground speed so found will differ nearly always from the air speed, as shown by the air speed meter, because of the effect of the wind. The difference is greater or less according to the wind's relation to the direction in which the aëroplane or airship is headed. Having found by observation the drift, the ground speed and the air speed, a simple instrument such as the Appleyard Course and Distance Calculator then permits the aërial navigator to discover without difficulty, as on a slide rule, the strength and direction of the wind. Should the actual track of aircraft over the earth's surface not coincide with the desired course, the Course and Distance Calculator, or a similar instrument, can thus be used to calculate, in connection with the wind velocity and direction already found, the direction in which the nose of the craft must be pointed in order to correct the deviation due to drift. [Illustration: THE LATE CAPT. SIR JOHN ALCOCK JUST BEFORE STARTING] [Illustration: SHIPPING THE FIRST DIRECT TRANSATLANTIC AIR MAIL] Knowing the latitude and longitude of the point of departure, and noting carefully the time that elapses between each separate observation of the ground speed and of the course, the air navigator, with the aid of a specially prepared set of "traverse tables" (as used by mariners), can easily plot on his chart the distance covered and the direction in which it has been covered. Hence the position of the aircraft at any time is either known definitely, or can be forecast with a fair degree of accuracy. For aërial navigation by means of "Dead Reckoning," frequent observations of ground speed and drift are necessary. If aircraft are cut off by clouds or fog from all possibility of sighting the surface of the earth, grave errors may occur, since in long distance flights the wind's velocity and direction often change without the pilot's knowledge. NAVIGATION BY ASTRONOMICAL OBSERVATION In navigation by astronomical observation, the position of the aëroplane or airship is found by observing the height above the horizon of either the sun or another heavenly body, such as a star that is easy of recognition. The method depends upon the known fact that at any given instant the sun is vertically above some definite point on the earth's surface. This point can be calculated from the time of the observation and the declination and equation of time, as tabulated in the nautical almanac. In the case of stars, the right ascension of the sun and of the star also enter into the calculation. The method of carrying out such calculations is too involved for the scope of this volume, and the reader is referred to many of the excellent text books published on the subject of navigation. Since the navigator knows, from the time of his observation, the point on the earth's surface over which is the heavenly body in question, it is clear that around this point circles on the surface of the earth may be described. From any point in any one circle the heavenly body will appear to have the same altitude or elevation above the horizon. A single observation of the altitude of any one heavenly body shows, therefore, only that the observer may be at any point on such a circle of equal altitude--otherwise known as a Sumner circle. But it does not fix that point. A second simultaneous observation, of a different heavenly body, will give a different circle, corresponding to the position of the second body. The intersection of these two circles determines the point of observation. This fact constitutes a reliable basis for fixing one's position during a clear night, when many stars are visible and choice of suitable heavenly bodies may be made. During the day, however, the light of the sun prevents other heavenly bodies from being seen, so that only a single observation is possible. If the aëroplane or airship were not moving, then two successive observations of the sun, with an interval of an hour or more between them, would give the intersecting circles and fix the position. But the aircraft being in motion, it is necessary to combine the method of "Dead Reckoning" with the use of the Sumner circles, as found by observation of the sun's altitude. In order to avoid drawing the entire circle, a small portion only of it is shown on the chart--so small that it may be regarded as a straight line. Such a small section of the Sumner circle is known as a "position line." The desired track is laid out on the chart, and the "Dead Reckoning" position for the time of the solar observation is indicated on it. The track should be intersected at this point by the position line, the observation thus forming a check upon the "Dead Reckoning." The altitude of the sun or of a star is measured by the sextant. For such an observation to be exact, it is necessary that not only should the sun or stars be viewed clearly, but that a clear horizon, formed either by the ocean or by suitable clouds, should be visible. Corrections must be applied to the observed altitude for the aircraft's height above the horizon, for refraction, and for the diameter of the body under observation--the latter two corrections being given in the nautical almanac. There may be, also, an error inherent in the sextant itself. For extremely refined navigation, corrections are applied in accordance with the direction and velocity of the aëroplane or airship; but these are not really necessary, since navigation of aircraft does not require such close calculation. When the sun or star observed is directly south of the aërial navigator in the northern hemisphere, or north of him in the southern hemisphere, the altitude, corrected for declination of the body under observation, gives the aircraft's latitude. When the navigator is directly east or west, the altitude, corrected for the time of observation, gives its longitude. If the horizon is invisible, owing to fogs or unsuitable clouds, it may be replaced by means of a spirit level; but great care should be taken in making such observations, since a spirit level on an aëroplane or airship is not wholly reliable, unless the craft is proceeding in an absolutely straight direction, and without sway of any kind. All methods of navigation by Astronomical Observation fail when the sky is obscured by clouds and the heavenly bodies cannot be seen. As a general rule this drawback does not hamper air navigation to any great extent, since aircraft should be able to climb above most of the obscuring clouds. Yet it may happen, as it did in the case of our transatlantic flight, that the clouds are too high for such a maneuver. If it were possible to measure accurately the true bearing of the sun or star at the moment of observation, then a single observation of a single heavenly body would fix the position of the craft at the intersection of the line of bearing with the position line. At the time of writing, however, there are no satisfactory means of making such a measurement with the required degree of accuracy. Apparatus which will enable this to be done is now in course of development. Navigation by means of astronomical observation will thereby be simplified greatly. NAVIGATION BY WIRELESS DIRECTION FINDER With the great improvements that have been made in the year 1919, the guiding of aircraft by directional wireless telegraphy is rapidly becoming a reliable and accurate means of aërial navigation. Although complicated in design and construction, the complete receiving equipment for aircraft is now light, compact, and simple of operation. [Illustration: HOT COFFEE WAS TAKEN ABOARD] [Illustration: SLOW RISING NEARLY CAUSED DISASTER AT THE START OF THE GREAT FLIGHT] The receiving equipment on aëroplanes and airships is arranged so as to indicate, with a comparatively high degree of accuracy, the direction from which wireless signals are received. The position of the sending, or beacon, station being known, the bearing of the aircraft from that station may be plotted on a suitable chart, in which small segments of great circles are represented by straight lines. Simultaneous bearings on two known beacon stations are sufficient to fix the observer's position with tolerable accuracy at the intersection of the lines of bearing, provided that they intersect at a reasonable angle--45 degrees or more, where possible. With the very close tuning rendered possible by the use of continuous waves, beacon stations of the future will probably be provided with automatic means whereby directional signals can be sent out at intervals of one hour or less. Such signals will be coded, so that the crews of aircraft can identify the wireless station. The wave lengths must be chosen so as not to interfere with messages sent from commercial stations. If there be a beacon station at the air navigator's destination, it is possible for him to direct his course so that the craft is always headed for the beacon; and in due time he will reach his objective. This simple but lazy method, however, is not to be recommended; for, owing to the action of the wind, the route covered is longer than the straight course. To counteract drift and proceed in a direct line towards his destination, the air navigator frequently has to direct his course so that the craft is not headed straight for the objective. Hence, with a single beacon station, frequent observations of drift are necessary, if the shortest route is to be followed. Thus: [Illustration: Approximate path taken by aircraft headed always towards beacon station.] [Illustration: Path taken by aircraft headed so as to counteract drift.] When two or more beacon stations are available, and positions can be ascertained at least once an hour, observation on the surface of the ocean for drift, although desirable, is not absolutely necessary. The drift may be calculated with accuracy enough from the craft's position as found by the lines of bearing indicated in messages from the various beacon stations. Another method of employing the Wireless Direction Finder is for aircraft to send out signals to two or more beacon stations, which reply by advising the air navigator of his bearing in relation to themselves. This is, perhaps, the most accurate method. Its disadvantage lies in the fact that whereas the heavier and more robust apparatus needed for it can easily be employed in the stationary beacon stations, few aircraft will be able to support wireless sending apparatus of sufficient weight to carry over the long distances they must cover in trans-oceanic aërial travel. The greatest advantage of air navigation by means of wireless telegraphy is that it can be employed in any weather. Fogs and clouds do not make it inoperative, nor even less accurate. Another recommendation is that its use does not entail a knowledge of advanced mathematics, as required for navigation by astronomical observation. I believe firmly that the air navigator of the future will rely upon the Wireless Direction Finder as his mainstay, while using astronomical observation and the system of "Dead Reckoning" as checks upon the wireless bearings given him, and as second and third strings to his bow, in case the wireless receiving apparatus breaks down. CHAPTER X THE FUTURE OF TRANSATLANTIC FLIGHT Although three pioneer flights were made across the Atlantic during the summer of 1919, the year passed without bringing to light any immediate prospect of an air service between Europe and America. Nor does 1920 seem likely to produce such a development on a regular basis. Before a transatlantic airway is possible, much remains to be done--organization, capitalization, government support, the charting of air currents, the establishment of directional wireless stations, research after improvements in the available material. All this requires the spending of money; and for the moment neither governments nor private interests are enamored of investments with a large element of speculation. But, sooner or later, a London-New York service of aircraft must be established. Its advantages are too tremendous to be ignored for long. Prediction is ever dangerous; and, meantime, I am confining myself to a discussion of what can be done with the means and the knowledge already at the disposal of experts, provided their brains are allied to sufficient capital. Notwithstanding that the first two flights across the Atlantic were made respectively by a flying-boat and an aëroplane, it is very evident that the future of transatlantic flight belongs to the airship. That the apparatus in which Sir John Alcock and I made the first non-stop air journey over the Atlantic was an aëroplane only emphasizes my belief that for long flights above the ocean the dirigible is the only useful vehicle. If science discovers some startlingly new motive power--for example, intermolecular energy--that will revolutionize mechanical propulsion, heavier-than-air craft may be as valuable for long flights as for air traffic over shorter distances. Until then trans-ocean flying on a commercial basis must be monopolized by lighter-than-air craft. The aëroplane--and in this general term I include the flying boat and the seaplane--is impracticable as a means of transport for distances over one thousand miles, because it has definite and scientific limitations of size, and consequently of lift. The ratio of weight to power would prevent a forty-ton aëroplane--which is approximately the largest heavier-than-air craft that at present might be constructed and effectively handled--from remaining aloft in still air for longer than twenty-five hours, carrying a load of passengers and mails of about five tons at an air speed of, say, eighty-five miles an hour. Its maximum air distance, without landing to replenish the fuel supply, would thus be two thousand, one hundred and twenty-five miles. For a flight of twenty-five hundred miles all the disposable lift (gross lift minus weight of structure) would be needed for crew and fuel, and neither passengers nor freight could be taken aboard. There is not in existence an aëroplane capable of flying, without alighting on the way, the three thousand miles between London and New York, even when loaded only with the necessary crew. With the very smallest margin of safety no transatlantic route of over two thousand miles is admissible for aëroplanes. This limitation would necessitate time-losing and wearisome journeys between London and Ireland, Newfoundland and New York, to and from the nearest points on either side of the ocean. Even under these conditions only important mail or valuable articles of little weight might be carried profitably. As against these drawbacks, the larger types of airships have a radius far wider than the Atlantic. Their only limit of size is concerned with landing grounds and sheds; for the percentage of useful lift increases with the bulk of the vessel, while the weight to power ratio decreases. A voyage by dirigible can therefore be made directly from London to New York, and far beyond it, without a halt. Another advantage of lighter-than-air craft is that whereas the restricted space on board an aëroplane leaves little for comfort and convenience, a large rigid airship can easily provide first-rate living, sleeping and dining quarters, besides room for the passengers to take exercise by walking along the length of the inside keel, or on the shelter deck. In a saloon at the top of the vessel no noise from the engines would be heard, as must be the case in whatever quarters could be provided on a passenger aëroplane. Yet another point in favor of the airship as a medium for trans-ocean flight is its greater safety. An aëroplane is entirely dependent for sustentation in the air on the proper working of all its motors. Should two motors--in some cases even one--break down, the result would be a forced descent into the water, with the possibility of total loss on a rough sea, even though the craft be a solid flying boat. In the case of an airship the only result of the failure of any of the motors is reduction of speed. Moreover, a speed of four-fifths of the maximum can still be maintained with half the motors of an airship out of action, so that there is no possibility of a forced descent owing to engine breakdown. The sole result of such a mishap would be to delay the vessel's arrival. Further, it may be noted that an airship's machinery can be so arranged as to be readily accessible for repairs and replacement while on a voyage. As regards comparative speed the heavy type of aëroplane necessary to carry an economical load for long distances would not be capable of much more than eighty-five to ninety miles an hour. The difference between this and the present airship speed of sixty miles an hour would be reduced by the fact that an aëroplane must land at intermediate stations for fuel replenishment. Any slight advantage in speed that such heavier-than-air craft possess will disappear with the future production of larger types of dirigible, capable of cruising speeds varying from seventy-five to ninety miles an hour. For the airship service London-New York direct, the approximate time under normal conditions should be fifty hours. For the aëroplane service London-Ireland-Newfoundland-New York the time would be at least forty-six hours. Perhaps the most convincing argument in favor of airships as against aëroplanes for trans-ocean aviation is that of comparative cost. All air estimates under present conditions must be very approximate; but I put faith in the carefully prepared calculations of experts of my acquaintance. These go to show that, with the equipment likely to be available during the next few years, a regular and effective air service between London and New York will need (again emphasizing the factor of approximation) the following capital and rates: Aëroplane Airship Service[1] Service[2] Capital required $13,000,000 $19,300,000 Passenger rate: London-New York $240 $575 Rate per passenger: Mile 8 cents 18 cents Mails per ounce: London-New York 6-1/4 cents 15-1/2 cents These figures for an airship service are based on detailed calculations, of which the more important are: _Capital Charges_: Four airships of 3,500,000 cu. ft. capacity, at $2,000,000 each $8,000,000 Two double airship sheds at $1,500,000 each 3,000,000 Land for two sheds and aërodromes at $150,000 each 300,000 Workshops, gas plants, and equipment 750,000 Working capital, including spare parts, stores, etc. 850,000 Wireless equipment 50,000 Miscellaneous accessories 50,000 ----------- Total capital required $13,000,000 ----------- Annual charge, interest at 10% $1,300,000 _Depreciation and Insurance_: Airships. Useful life, about 3 years. Obsolete value, about $100,000 per ship. Total depreciation per ship, $1,900,000 in three years. Average total depreciation per annum for four ships for 3 years, $2,535,000. Airship sheds. Total annual charge $90,000 Workshops and plant. Depreciation at 5% per annum 17,500 Total annual charge for depreciation 2,650,000 Total annual insurance charges on airships and plant 617,500 _Annual Establishment Expenses_: Salaries of Officers and Crews-- 4 airship commanders $20,000 8 airship officers 30,000 Total number crew hands (64) 80,000 $130,000 ------------------ $130,000 Salaries of Establishment-- Management and Staff $25,000 Workshop hands, storekeepers, etc. (50 at each shed--total 100) 100,000 $125,000 ------------------ Total annual establishment expenses $255,000 _Repairs and Maintenance_: Sheds and plant, annual charge, say, $25,000 Repairs and overhaul of airships 100,000 Total charge $125,000 ---------- Total annual charges on above basis $4,947,500 Say $5,000,000 _Cost Chargeable per Crossing_: Taking the total number of crossings per year as 200 (London-New York)-- Proportion of annual charges per crossing $25,000 Petrol per trip, 30 tons at $125 per ton. 3,750 Oil per trip, 2 tons at $200 per ton 400 Hydrogen used, 750,000 cu. ft. at $2.50 per 1,000 cu. ft. 1,875 Cost of food per trip for crew of 19 and 100 passengers 2,000 -------- Total charge per crossing (London-New York) $33,025 The weight available for passengers and mails on each airship of the type projected would be fifteen tons. This permits the carrying of one hundred and forty passengers and effects, or ten tons of mails and fifty passengers. To cover the working costs and interest, passengers would have to be charged $240 per head and mails $2,025 per ton for the voyage London-New York. This charge for passengers is already less than that for the more expensive berths on transatlantic liners. Without a doubt, with the coming of cheaper fuel, lower insurance rates and larger airships, it will be reduced eventually to the cheapest rate for first-class passages on sea liners. With a fleet of four airships, a service of two trips each way per week is easily possible. For aëroplanes with a total load of forty tons the weight available for passengers and mails is 2.1 tons. If such a craft were to carry the same weekly load as the service of airships--thirty tons each way--it would be necessary to have fourteen machines continually in commission. Allowing for one hundred per cent. spare craft as standby for repairs and overhaul, twenty-eight aëroplanes would be required. The approximate cost of such a service is: _Capital Charges_: 28 aëroplanes at $600,000 each $16,750,000 28 aëroplane sheds at $50,000 each 1,400,000 Land for 4 aërodromes 500,000 Workshops and equipments 100,000 Spare parts, etc. 500,000 Wireless equipment 50,000 ----------- Total capital required $19,300,000 Annual charge at 10% interest $1,930,000 _Depreciation and Insurance_: Aëroplanes. Useful life, say 3 years, as for airships. Obsolete value, say, $30,000 per machine. Average total depreciation per annum for 28 machines $5,250,000 Aëroplane Sheds. Total annual charge 60,000 Workshops and Plant. Depreciation at 3% per annum 3,000 Total annual charge for depreciation 5,314,000 Total annual insurance charges on machinery and plant 1,152,000 _Annual Establishment Expenses_: Salaries of 36 pilots at $3,000 per annum $108,000 Salaries of 36 engineers at $2,000 per annum 72,000 Salaries of 12 stewards at $1,500 per annum 18,000 Salaries of establishment-- Management and staff 25,000 Workshop hands and storekeepers, etc., 100 off 100,000 -------- Total annual establishment expenses $323,000 _Repairs and Maintenance_: Sheds and plant, annual charge, say $25,000 Repairs and overhaul to machines 50,000 -------- Total. $75,000 ---------- Total annual charges on above basis $8,792,500 _Cost chargeable per crossing_: Proportion of annual charges per crossing $7,250 Petrol used per trip, 28 tons at $125 per ton 3,500 Oil per trip, 2 tons at $200 per ton 400 Cost of food per trip for 29 passengers and crew of seven 500 ------- $11,650 It will be seen from the above that the direct running cost is 38%, and the overhead charges 62% of the total cost. With a weight of 2.1 tons available on each machine for passengers and mails twenty passengers might be carried. To cover the working costs and interest they must be charged $575 per head. The rate for mails would be $5,500 per ton. Having made clear that the airship is the only means of transatlantic flight on a paying basis, the next point to be considered is the type of dirigible necessary. A discussion at present of the size of the airships that will link Europe and America can be little more substantial than guesswork. The British dirigible _R-34_, which last year made the famous pioneer voyage between England and the United States, is too small for commercial purposes, with its disposable lift of twenty-nine tons and its gas capacity of less than two million cubic feet. Experts have predicted the use of airships of five million and ten million cubic feet capacity, with respective weights of thirty tons and one hundred tons available for passengers and freight. It is probable, however, that such colossi must await birth for many years, and that a beginning will be made with moderate-sized craft of about three million, five hundred thousand cubic feet capacity, similar to those that serve as the basis of the estimates for a service between London and New York. A combination of British interests is planning to send ships of this type all over the world. These can be built immediately, and there are already in existence suitable sheds to house them. Details of their structure and capabilities may be of interest. [Illustration: LUCKY JIM AND TWINKLETOE, THE MASCOTS] [Illustration: THE TRANSATLANTIC FLIGHT ENDED WITH A CRASH IN AN IRISH BOG] The projected airship of three million, five hundred thousand cubic feet capacity is capable of carrying a useful load of fifteen tons (passengers and mails) for a distance of forty-eight hundred miles in eighty hours, at the normal cruising speed. The total lifting power is one hundred and five tons, and the disposable lift (available for fuel, oil, stores, crew, passengers and freight) is sixty-eight tons. The maximum engine power is thirty-five hundred h. p., the maximum speed seventy-five miles an hour. The normal flying speed, using a cruising power of two thousand h. p., is sixty miles an hour. The overall length is eight hundred feet, the maximum diameter and width one hundred feet, and the overall height one hundred and five feet. These particulars and performances are based on present design, and on the results attained with ships of two million cubic feet capacity, now in service. The figures are conservative, and it is probable that a disposable lift greater than that of the specifications will be obtained as a result of improved structural efficiency. The passenger accommodation will be such that the air journey can be made in comfort equal to that on a first-class liner of the sea. Apart from their comparatively small disposable lift, a main objection to vessels of the _R-34_ type for commercial purposes is that the living quarters are in cars slung from under the middle envelope. In this position they are necessarily rather cramped. In the proposed craft of three million, five hundred thousand cubic feet capacity the passengers' quarters are at the top of the vessel. There, they will be roomy and entirely free from the vibration of the engines. They are reached through an internal corridor across the length of the ship, or by elevator, from the bottom of it. The main room is a large saloon lounge fitted with tables and chairs in the style of a Pullman car. Around it are windows, allowing for daylight and for an outlook in every direction. Part of it is fire-proofed, and serves as a smoking room. Next to, and communicating with, the lounge is the dining saloon. This leads to a serving hatch and electrical cooking apparatus. Electrical power is provided by dynamos driven off the main engines. Current for electric lighting and heating of the saloons, cars and sleeping quarters is provided by the same method. Sleeping accommodation is in four-berth and two-berth cabins on top of the airship and forward of the living saloons. The cabins are of the type and size fitted on ocean-going steamers. With them are the usual bathrooms and offices. Other conveniences are an open shelter deck at the vessel's aft end, to enable passengers to take the air, and an observation car, fitted below the hull and also at the aft end, so that they can observe the land or sea directly below them. No danger from fire need be feared. The machinery installation is carefully insulated from the gas bags, and the quarters are to be rendered fire-proof and gas-proof. Moreover, the amount of weight involved by the passengers' section is so small, compared with the weight of the machinery, fuel, cargo and stores, carried in the lower part of the craft, that the stability of the ship for rolling is unaffected by the novel position of the living quarters. The ship's officers will have on the hull, towards the forward end, a control and navigation compartment, containing the main controls, navigation instruments, charts, and a cabin for the wireless telegraphy installation. The windows of this car give a clear view in every direction. Other general specifications are: _Hull Structure._--The shape of the hull is of the most perfect stream-line form within the limitations of constructional requirements. An internal keel corridor, running along the bottom of the hull, contains all petrol and oil tanks and the water ballast. _Outer Covering._--The outer cover is made of special weather-proof fabric, which gives the longest possible life. This fabric is as efficient as possible in insulating the gas from change of temperature, and thus avoids great variations in the lift. _Gasbags._--The gas capacity is divided up into gasbags made of suitable rubber-proofed cotton fabric, lined with gold-beaters' skins. Gasbags will be fitted to automatic relief valves and hand control maneuvering valves. _Machinery Cars._--Six machinery cars are provided, each containing one engine installation, with a direct-driven propeller fitted at the aft end. These compartments give the mechanics easy access to each of the six engines, and allow them to handle all parts of the machinery. Engine room telegraphs of the electrical type communicate between the forward compartment and each of the machinery cars. Whereas the living quarters and the control compartment must be heated by electric radiators, arrangements can be made to warm the machinery cars by utilizing the exhaust heat. The transmission gear in two of the wing cars is to be fitted with reversing gear, so that the craft may be driven astern. So that passengers shall not be worried by the usual roar of the exhaust, special silencers will be fitted. The transmission gear is also so arranged that all unnecessary clamor from it may be avoided. The engines run on gasoline fuel, but they have devices whereby they can be run alternatively on hydrogen gas. They are designed to develop their maximum power at a height of five thousand feet. _Telephones._--Telephone communication links all stations on the airship. _Landing Gear._--Inflated buffer landing bags of a special type are to be fitted underneath the Forward Control Compartment and underneath the two Aft Machinery Cars. These enable the airship to alight either on land or on the sea's surface. _Wireless Telegraphy._--A powerful wireless telegraphy installation is to be fitted in the wireless cabin in the forward control compartment. It will have a range for sending and receiving of at least five thousand miles. _Crew._--Two watches would be required, taking duty in eight-hour shifts. Both must be on duty when the craft leaves or lands. Each watch consists of navigating officer, steersman, elevator man, four engineers and a wireless operator. With the commanding officer and two stewards, whose duties are not regulated by watches, the crew thus numbers nineteen men. Although the speed of the airship at maximum power is seventy miles per hour, the crossing normally would be made at sixty miles per hour, which only requires two thousand horse power, and is much more economical in fuel. The full speed, however, can be used whenever the ship is obliged to voyage through storm areas or against strong head winds. By the Azores route, the time needed for the journey of thirty-six hundred miles, at a speed of sixty miles per hour, is sixty hours; but to allow for delays owing to adverse weather, the airship would always carry eighty hours' fuel, allowing for a speed of sixty miles per hour. The normal time for the journey from London to New York, via Portugal and the Azores (thirty-six hundred miles) would be, therefore, two and one half days. The normal time for the journey New York to London by the direct route (three thousand miles) would be just over two days. The prevailing wind on the direct route is almost always from West to East, which favors the Eastbound journey, but is unfavorable to the Westbound journey. It is proposed that the crossing Eastward from New York to London be made by the most direct route, advantage thus being taken of the Westerly winds. By making the Westbound journey on the Southerly route, via the Coast of Portugal and the Azores, and on 35´ N. parallel of latitude across the Atlantic, and then to New York, the voyage is made in a region where the prevailing Westerly winds of the higher latitudes are absent, and only light winds are encountered, generally of a favorable direction. This route, however, adds about six hundred miles to the distance. With a ship speed of sixty miles per hour, it would be quicker to make the Westbound journey by the direct route if the Westerly wind did not exceed ten miles per hour. If the wind were greater, time would be saved by covering the extra six hundred miles of the Southerly route and dodging the unfavorable air currents. With four airships on the Cross-Atlantic airway, two only would be in service at a time, so that each could lay up during alternate weeks for overhaul and re-fit. As the time of journey between London and New York will vary between fifty to sixty hours, each airship can easily make two crossings or one double journey per week, thus giving a service, with two dirigibles, of two "sailings" each way per week. The average time table might therefore be as follows: LEAVE LONDON ARRIVE NEW YORK Monday morning Wednesday afternoon or evening Thursday morning Saturday afternoon or evening LEAVE NEW YORK ARRIVE LONDON Monday afternoon Thursday morning Thursday afternoon Sunday morning. From available weather reports, it is considered that crossings are practicable on at least three hundred days in the year. Probably a total of two hundred crossings in the year could be maintained. Until further study of weather conditions supplies a certain knowledge of the best possible altitudes and latitudes, it is likely that a regular service of two crossings each way per week will be maintained only in the months of May to September, and that the crossings from October to April will be irregular, the day of departure being dependent on the weather. Weather difficulties are likely to be much less severe than might be imagined. Rain, hail and snow should have little influence on the navigation of airships. An outer covering that is rainproof and non-absorbent avoids the absorption of water and the consequent increase of weight. Hail and snow cannot adhere to the surface of the craft when in flight, owing to its high speed through the air; and, in any case, the precipitation height being not more than eight thousand feet, they can be avoided by flying above this altitude. Fog may give trouble in landing, but during the journey an airship can keep above it. If the terminal were enveloped by fog an arriving ship could pass on to an emergency landing ground away from the fog-belt; if the mistiness were slight, it could remain in the air until the ground were visible, making use of its margin of fuel beyond the amount necessary for the London-New York flight. Airships in fog may be enabled to find their landing ground by means of captive balloons or kites, and of strong searchlights from the ground. At night, the balloons or kites could carry electric lights, with connections from the aërodrome. In any case, fog, rain, hail and snow are nearly always local in their occurrence, and can be avoided by a short deviation from the usual route. Atlantic records indicate that on the main steamship routes fog sufficient to impede navigation does not occur on more than about twelve days in the year. Wind is a factor that needs more careful study in its relation to transatlantic air navigation. In most cases, unduly strong winds can be dodged by flying on a higher level, or by cruising on a different course, so as to avoid the storm belt. Heavy storms, which are usually of a cyclonic nature, rarely cover an area of more than two hundred miles diameter. Moreover, the rate of progression of a cyclonic area is much less than the speed of the air movement. An airship is able to shake off a cyclonic area by a deviation from its course of not more than two hundred miles. Once away from the storm belt, it has no difficulty in keeping clear of it. When higher levels of the air have been charted, there is every reason to believe that the known movements of the Atlantic winds will be used to shorten air journeys. There are at sea level, between certain clearly defined latitudes, prevailing winds of constant direction. At greater heights, also, there is in most latitudes a constant drift which, if charted, might be useful even if winds at sea level were unfavorable. Although precise information is available of the prevailing and periodic winds at sea level in various latitudes, very little coördinated work appears to have been done in charting the prevailing and seasonal winds in higher levels of the atmosphere. Observations of the air currents over various localities in the United States, England and Germany have been taken, but very little is known of the winds above the great ocean tracts. There is a great necessity for international research to provide data for predictions of weather conditions in the upper atmosphere and thus enable advantage to be taken of these higher currents. At high altitudes, constant winds of from thirty to forty miles per hour are common. If the prevailing directions of those were known to airship navigators, the duration of the journey could be considerably shortened, even if this meant taking an indirect route. It is undesirable to fly at great heights owing to the low temperature; but with suitable provision for heating there is no reason why flying at ten thousand feet should not be common. Air currents cannot be charted as exactly as sea currents; but much valuable work can and will be done by tabulating in detail, for the guidance of air navigators, the tendencies of the Atlantic atmospheric drifts. Reliable charts, used in conjunction with directional messages from wireless stations and ships, may make it possible for vessels on the London-New York air service always to avoid troublesome winds, as well as storms and fogs, and to reduce the percentage of risk to a figure not exceeding that relative to sea liners. For the rest, the excellence of the most modern engines and the fact that one or two, or even three of them can be temporarily out of action without affecting the airship's stability during a flight, minimize the danger of a breakdown from loss of power. The only remaining obstacle to reasonable safety would seem to be in landing on and departing from the terminal during rough weather. This can be overcome by the recently patented Vickers Mooring Gear for Rigid Airships. The gear, designed so as to permit an airship to land and remain moored in the open for extended periods in any weather without the use of sheds, consists principally of a tall steel mast or tower, about one hundred and fifty feet in height, with a revolving head to which the craft is rigidly attached by the nose, permitting it to ride clear of the ground and to turn round in accordance with the direction of the wind. It is provided with a hauling-in winch and rope to bring the ship up to the mooring point. An elevator, for passengers and goods, runs up the tower from the ground to the platform adjoining the nose of the airship. The passengers reach their quarters along a passage through the vessel, and the goods are taken down a runway. An airship moored to this mast can remain unharmed in even the worst weather, and need be taken into a shed only when overhaul and repairs are necessary. In discussing the future of transatlantic flight I have confined myself to the projected service between London and New York. There is likely to be another route over the Atlantic--London to Rio de Janeiro, via Lisbon and Sierra Leone. Already in London tickets are on sale at $5,000 apiece for the first flight from London to Rio. This, of course, is a freak price, which covers the distinction of being in the first airship to travel from England to Brazil. If and when a regular London-Rio service is established, the ordinary passenger rate should be little more than the $240 estimated as the air fare on the London-New York route. It may be that the London-New York air service will not arrive for many years. Sooner or later, however, it must arrive; for science, allied to human enterprise, never neglects a big idea. It may be that, when it does arrive, the structure of the craft and the methods of navigation applied to them will differ in important details from what I have indicated. I make no pretense at prophecy, but have merely tried to show how, with the means already at hand, moderately priced air journeys from Europe to America can be made in two to two and a half days, with comfort, safety and a high degree of reliability. Meanwhile, much depends on the funds available for the erection of stations for directional wireless messages, on research into the air currents at various levels above the Atlantic Ocean, on the courage of capitalists in promoting what seems to be a very speculative enterprise, and on new adaptations of old mechanical inventions. Already hundreds of aëroplanes, as time-saving vehicles, are used regularly in many countries for commercial traffic over comparatively short distances--the carriage of mails, passengers, valuable freight and urgent special journeys. When, but not until, the hundreds become thousands, and the longer distances are as well served by airships as are the shorter distances by aëroplanes, the world's air age will be in sight. [Footnote 1: For airships with gross gas capacity of 3,500,000 cubic feet and total load of 105 tons.] [Footnote 2: For machines with total load of 40 tons.] CHAPTER XI THE AIR AGE Although facts disappointed many over-sanguine expectations that the billions of dollars invested in aëronautics during the war would pay direct dividends already in 1919, the year brought us a long step nearer the age of universal flight. Meantime, commercial aviation is still a long way from the stage at which bankers regard its undertakings as good security for loans. [Illustration: CHART OF THE NORTH ATLANTIC SHOWING COURSE OF THE FLIGHT] [Illustration: THE MEN WHO WORKED WITHOUT GLORY TO MAKE THE FLIGHT POSSIBLE] Air routes have been opened up in most parts of the world. Captain Ross-Smith has shown, by his magnificent journey from England to Australia in a Vickers-Vimy aëroplane, that long-distance flights over the most out-of-the-way lands and ocean tracts can be made even under the present unsatisfactory conditions, before terminals, landing grounds and wireless stations are provided for air pilots and navigators. The Atlantic has been crossed four times, twice by a dirigible, once by an aëroplane and once by a flying boat. Aëroplanes have flown from England to India. Aircraft have been used for commercial purposes in every part of Western Europe, in most countries of North and South America, in Australia, India, Egypt and South Africa. Important exhibitions of modern aircraft, similar to automobile shows, have been held in London, New York, Paris, Amsterdam and elsewhere. To-day all the Great Powers can show commercial air services in full operation. Of these the most important are perhaps the triangular airways around London, Paris and Brussels. One French and two British companies operate daily between London and Paris; British craft travel backwards and forwards between London and Brussels three times a week; and French machines fly between Paris and Brussels every day. The London-Paris services have established a magnificent record for efficiency and regularity. Valuable and urgent freight of every kind, including furs, dresses, jewelry, documents, a bunch of keys, perfume, a grand piano and even a consignment of lobsters, have been delivered in safety. Forty pounds of assorted London newspapers are taken each morning to Paris, where they are sold in the streets on the day of publication instead of next morning, as was the case when they were forwarded by train and packet-boat. Leading London papers, such as the _Times_, the _Telegraph_, the _Morning Post_, the _Daily Mail_, and the _Daily Express_, have regular contracts with one of the companies. As for passengers, men of every occupation take advantage of the opportunity to travel comfortably from London to Paris in two and one-quarter hours. There is seldom a vacant seat on the larger machines; although the fare is at present rather high, ranging from $75 to $105 for the single journey. Moreover, the accommodation on two of the types of aëroplane now used--the Handley-Page _W-8_ and the Airco _DH-18_--is more attractive than that of a Pullman car. The Handley-Page _W-8_ carries fifteen to twenty passengers with personal luggage, or two tons of freight. The Airco _DH-18_ takes eight passengers, with their personal luggage. The past year saw no specially important developments of commercial aviation inside Great Britain itself. A week-end service between Southampton and Havre was inaugurated, and passengers and mails were flown from London to Leeds. The most important undertaking was perhaps the delivery by air of newspapers. For a time the Manchester edition of the _Daily Mail_ was taken by air for distribution in Carlisle, Dundee and Aberdeen, the last-named place being reached in three and one-quarter hours instead of the thirteen hours of train journey. Evening newspapers were carried daily during the summer from London to various resorts on the South coast. The London-Leeds undertaking is the only regular service between English towns that has lasted for long. Elsewhere the air rates proved to be too high, and although there were plenty of aërodromes, the promoters of aërial transport companies could not compete with the all-embracing network of railways. During the great railway strike of October, however, valuable transport work was done by aircraft. For the rest, aëroplanes in England are chartered as aërial taxicabs for special trips, and last summer one or two companies reaped a moderate harvest by organizing pleasure trips at the seaside resorts. An airship or two have taken tours around the battlefields of France and Flanders. A few wealthy amateurs have bought aëroplanes for their private use. Other European countries--France, Italy, Holland, Belgium, Scandinavia, Spain and Portugal--have made rather less progress in the manufacture and development of aëroplanes or dirigibles; but their use of aircraft for commercial purposes was about the same as that of Britain--newspaper distribution, some special journeys, and many joyrides. French aviators have opened tentative airways to Morocco, Senegal and Tunis. For regular passenger or goods services in continental Europe the high cost of fuel and accessories makes the rates too high. Also aërodromes and landing grounds are too few; and seldom can aëroplanes compete on a large scale with railways over comparatively short distances. Exceptions are the Paris-Lyons and Madrid-Lisbon airways. Germany, throughout what was for her a terrible year, made further progress with her Zeppelin dirigibles. A number of return voyages were made over the route Berlin-Munich-Vienna-Constantinople. The latest type of Zeppelin is so efficient that no weather conditions, except a strong cross-hangar wind, prevents the airship _Bodensee_ from making its daily flight of three hundred and ninety miles between Friedrichshafen and Staalsen, thirteen miles from Berlin. The passenger carrying Zeppelins, which prior to the war provided the only important example of commercial aircraft, claim a remarkable record. They have carried more than one hundred and forty thousand people, and yet not one of the passengers has been killed or injured in an accident; although some members of the crews lost their lives in the early days of the pioneer Zeppelins. The vast distances of the United States offer better opportunities for aëroplane traffic than the comparatively small and closely-railwayed countries of Western Europe. There is no doubt that, had the United States government supported its aircraft companies to the same extent as did the British government, commercial aviation in America would have traveled along a smooth road. Even without this support it has made excellent progress. Successful regular services are established between Los Angeles and San Diego, and elsewhere in the West, and in the East many passengers have been carried between New York and Atlantic City, and around the coast of Florida. Plans are being laid for various other airways, including one between Key West and Havana. While no continuous service for aërial goods traffic exist in the United States, aëroplanes are often chartered for special deliveries. This is particularly the case in the oil countries of Texas and Oklahoma, where newly-grown and important centers are off the beaten railroad track. One company in Oklahoma regularly sends its employees' pay by aëroplane from town to oilfield camp, thus assuring a quick and safe delivery, free from the necessity of armed guards and the danger of hold-ups. Other items worth noting in the United States' aërial history of the past twelve months are that aëroplanes have performed survey work and located forest fires, that thirty-two cities have applied for commercial aërodromes for postal, passenger and express purposes, and that an advertising agency is soliciting aërial business that will include display work on dirigibles, balloons and aëroplanes, the dropping of pamphlets from the air, and aërial photography. Where the United States undoubtedly leads the way is in the ownership and use of privately owned aëroplanes--a circumstance partly explained by the great quantities of new money being spent. For a time some of the American manufacturers were months behind their post-war orders, and were selling everything that could fly. One famous company disposed of hundreds of pleasure craft at $7,500 apiece. Many buyers, impatient of delay, accepted immediate delivery of training machines, rather than wait for the pleasure craft. Reputable agencies dealing in second-hand aëroplanes bought from the United States and Canadian governments, disposed of thousands of machines and could not obtain enough to satisfy all their clients. An interesting development was the idea of community aëroplanes, purchased and maintained jointly by small groups of people living in the same residential district. The United States postal authorities have satisfactorily maintained aërial mail services over the route New York-Washington-Cleveland-Chicago. After some preliminary fiascos these became reliable, besides being very speedy, as compared with train schedules. For June the Washington-New York air mail achieved ninety-nine per cent. efficiency, and the Cleveland-Chicago route one hundred per cent. The latter never missed a day in May and June, and not a single forced landing occurred during the first seventy days. At the close of 1919 the air mails showed a surplus of $19,000 of revenue over working costs, on a basis of two cents charge for each ounce of mail matter carried. Better results are expected now that specially constructed machines, with freight capacities of one thousand pounds and upward, are ready for use. The British dominions and dependencies take a great interest in aëronautics, and last year saw satisfactory beginnings in some of them. In Australia, for example, a passenger and freight service links Sydney and Port Darwin, over a distance of twenty-five hundred miles, with intervening stations. Plans are ready for regular flights from North to South of the continent, and also from East to West, across the difficult country between New South Wales and Victoria on the one hand, and Western Australia on the other. Canada has found a highly successful use for aëroplanes in prospecting the Labrador timber country. A group of machines returned from an exploration with valuable photographs and maps of hundreds of thousands of dollars' worth of forest land. Aërial fire patrols, also, have been sent out over the forests. While no important air route for passenger carrying is yet utilized in Canada, there is a certain amount of private flying, and air journeys for business purposes are common. Plans have been prepared for a regular service between Newfoundland and cities on the mainland, thus saving many hours over the time schedules perpetrated by the little Newfoundland railway. In the South African Union, where the railway system by no means corresponds with the vast distances, many passengers and mails are carried by air from Johannesburg to Pretoria, Maritzburg, Durban and Cape Town. Later, when the services over these routes are better organized, they will doubtless be extended to important centers in Rhodesia, the East Africas and what was German South-West Africa. Aëroplanes in India take passengers over the route Calcutta-Simla in twelve to fourteen hours of cool roominess, as compared with forty-two hours of stuffy oppressiveness on a train. Other Indian air routes in preparation are Calcutta-Bombay, Calcutta-Darjeeling and Calcutta-Puri. The air fare in India averages about 11 cents a mile. Aërodromes and landing grounds are already prepared between Egypt and India, and several machines have made the journey from Cairo to Delhi, via Damascus, the Syrian Desert, Bagdad, Bandar Abbas and Karachi. Elsewhere in the East--the Malay Peninsula, Singapore, Borneo, Java and China--similar routes are planned. The whole of Eastern Africa, from Cairo to Cape Town, has been mapped out for the use of aircraft, with landing grounds at short intervals. So much for accomplishment during the past year. What the future and the near-future have in store for aëronautics is problematical, and any detailed analysis must be conjecture. The general trend of development during the next two years may be forecast, however, with a fair degree of accuracy. Anybody who blends sane imagination with some knowledge of the history of aëronautics must realize that what has been achieved is very little in comparison with what can be achieved. It is unnecessary to make trite comparisons with the first stages of steam locomotives or motor cars. Yet, it is folly to expect an air age now. Its coming will be delayed by the necessity of slow, painstaking research, and by the fact that in the countries which are encouraging aviation to the greatest degree, capital is no longer fluid and plentiful, and money in substantial sums cannot be risked on magnificent experiments. The cost of building fleets of dirigibles and hosts of air terminals, for example, must be enormous; and until it has been demonstrated beyond question that they will be paying propositions, financiers and investors are unlikely to be interested in their concrete possibilities on a large scale. Unless some startling innovation--a much cheaper fuel for example, or a successful helicopter--revolutionizes commercial aviation, its near-future is unlikely to stray beyond the extension of airways over distances of about five hundred to two thousand miles. These are likely to be covered mostly by heavier-than-air craft, although, as in Germany, dirigibles will have their place. Extension of air traffic is especially probable in industrial and agricultural countries of large area, such as the United States, Canada, Australia, India and the South American republics. Another projected development with immediate possibilities is the linking of regions that are separated by a comparatively narrow expanse of water. Obvious examples, in addition to Britain and France, are England and Ireland, the Mediterranean coast of France and the Mediterranean coast of Africa, and Florida and Cuba. Traffic across the ocean or a great lake offers to air travel the best time-saving inducement. To connect two places separated by one hundred and fifty miles of water, an average steamship needs ten hours. A passenger on it must spend at least one night away from home, while transacting his business. An air passenger covers the same distance in one and one-half to two hours, and can return on the same day. For such transport the seaplane and the flying boat will have their chance. Besides the carriage of passengers, mails and valuable freight, aviation will have many additional functions. Maps may be made and checked with absolute accuracy by means of aërial photography. Another important function of the aëroplane and the aërial camera is to explore and prospect undeveloped districts. In places remote from the ordinary facilities of civilization aircraft may be used for the discovery of fire, flood and lawlessness. Already the Canadian Northwest Mounted Police have captured wrongdoers by means of aëroplane patrols. Aircraft offer particular advantages as carriers in regions where the natural obstacles on the ground prohibit railway or road transport. In Alaska valuable metals and furs are brought to civilization on sleds drawn by dogs, over paths that are circuitous and dangerous. They could be taken in safety, and with an immense saving of time, by aëroplanes fitted with skids suitable for landing on ice and snow. Again, copper is transported from mines in the Andes by llamas, which are slow and must jog over devious tracks. Aëroplanes could make the journey directly and speedily, from mine to coast, without regard to precipice, marsh or forest. South America is likely to be a happy hunting-ground for aëronautical pioneers. The mountain-range of the Andes, which for hundreds of miles sharply divides America into two parts, gives aviation an incontestable opportunity. The eastern section of South America could be brought days nearer the western section by high-climbing aircraft, which would provide a pleasant alternative to the roundabout, uncomfortable journeying now necessary. The air mails between the two great commercial centers of South America--Rio de Janeiro and Buenos Ayres--should also save many days of valuable time. Many owners of ranches and plantations in the Argentine, Uruguay, Paraguay and Brazil are buying aëroplanes to bring their isolated, up-country properties in closer contact with the towns. Asia and Africa have similar geographical problems, to which air traffic might find a ready solution. Each of these continents has enormous areas that, because of the absence of good railways, are either unproductive or much less productive than their resources warrant. A few of many such cases are Turkestan, Central Arabia, parts of China, Siberia, Thibet, and the whole of Central Africa. Most of these are rich in minerals. Meanwhile, aëroplanes have flown between the desert marts of Damascus and Bagdad in eight to ten hours. These cities are not yet linked by railroad and a camel caravan over the Syrian desert covers the same route in two weeks to a month. The same conditions apply to the Gobi desert. So far I have dealt with the future of commercial aëronautics almost entirely in terms of heavier-than-air machines. These--land planes, seaplanes and flying boats--have at present a useful radius of non-stop flight confined to distances of under one thousand miles. The limitation must remain until changes in the basic principles of aëroplane construction are so altered as to give a much greater speed in proportion to fuel consumption. One such change may be the introduction of wings with variable camber. This, by permitting variations in the angle of incidence, would make possible a quick ascent at a steep inclination, and a very fast forward speed once the required height had been attained. The benefits from variable camber could be increased by the introduction of a propeller with a variable pitch. Going still further in the same direction, we may find any day that one of the attempts in various countries to design and construct a successful helicopter has matured, producing a machine which, by reason of a very powerful propeller on a moveable shaft that can be inclined in any direction, will not only rise and descend vertically, but also may be made to travel forward at a great speed and to perform such acrobatic tricks as sudden halts, retreats and jumps. All this, however, is surmise; and we are faced with the fact that until the design of aëroplanes differs radically from its present form, heavier-than-air flying apparatuses are limited as to maximum size by certain structural principles too complicated for explanation in this non-technical analysis. A further limitation is imposed by the space needed by the largest machines for leaving the ground or landing. Within these bounds it has been found that the maximum capacity for passengers and freight does not greatly exceed one and one-half to two tons for a non-stop journey of five hundred miles in still air. Lesser distances do not increase the useful load appreciably, but greater distances decrease it; until for a radius of about twenty-five hundred miles the whole of the disposable lift is needed for fuel, and nothing else may be carried. For long journeys over land, therefore, the aëroplane must come to earth for replenishment of fuel every five hundred miles. Even for this distance it cannot take more than one and one-half to two tons beyond the weight of fuel and crew. If heavier loads are to be transported, more machines must be used. Finally there comes a point at which a single airship, carrying a heavy freight over five hundred miles, is more economical than several aëroplanes. For non-stop flights of over one thousand miles the same considerations make the airship always more economical than the aëroplane. Over the ocean the flying boat can beat the dirigible in time and cost up to five hundred miles. Even at one thousand miles it is a commercial proposition, but it must then have all in its favor. For longer distances the airship has no competitor. It may be deduced that in years to come, when the world's airways are in general operation, heavier-than-air machines will bring freight to the great airports, there to be transferred to dirigibles and by them carried to the earth's uttermost ends. The time for this seeming Utopia is not yet, however, although a group of airship interests in England are now planning airship services that may eventually set London within two and a half days of New York, one and a half days of Cairo, four of Rio de Janeiro, five and a half of Cape Town and seven of Australia. But first must come bold expenditure, very careful organization, many-sided research and improved invention. Although no claim is made that present-day airships can compete for reliability with railroad trains and ocean liners, there is no doubt that a sufficient number of passengers are prepared to pay relatively higher rates for the great saving in time taken for long distance journeys, particularly over the ocean. The demand would be mainly for the carriage of express freight and mail matter and for passenger traffic to serve people who wish to get from center to center in the shortest possible time. Another use for large airships would be the carrying of freight of high intrinsic value, such as valuable ores, from places otherwise inaccessible, or not provided with other means of direct transport. To meet the requirements of various purposes for which airships may be utilized, dirigibles of four kinds are projected: First, the airship of moderate size and high speed for carrying express, mails and passengers. Secondly, the air liner solely for passenger traffic, of a large size and speed. Thirdly, the large airship of comparatively slow speed, and great carrying capacity, for general transport. Fourthly, the small non-rigid airship for private purchase and upkeep as an aërial yacht. [Illustration: THE VICKERS AEROPLANE WORKS AT WEYBRIDGE, ENGLAND] [Illustration: COMFORT CAN BE ENJOYED IN AIR TRAVEL TO-DAY] The rigid airship is as yet only at the beginning of its development, particularly as regards size and carrying capacity. The airship of three million, five hundred thousand cubic feet capacity, for immediate use on the fast passenger services, carrying a load of passengers of fifteen tons for a distance of forty-eight hundred miles, might be built immediately, and could be housed in sheds at present available. As the lift and speed efficiency of a rigid airship increases rapidly in proportion to the vessel's size, it will be advantageous to use the largest airships that can be economically operated. A rigid dirigible able to carry fifty tons of passengers and freight for ten thousand miles at a speed of eighty miles an hour is quite feasible; and the design and construction of such an airship could be undertaken immediately if it were justified by the demand for air transport. The ships of three million, five hundred thousand cubic feet capacity, which can be housed and flown for commercial purposes as soon as the required terminals and navigational facilities are ready, will approximate to those described as being suitable for a transatlantic service. If standardized for adaptation to all conditions and world routes, they should be capable of a non-stop flight of about eighty hours, at an average speed of sixty miles an hour. To prevent wastage and reduce the running costs, several economical devices for dealing with height equilibrium are needed. On long flights the greatest problems are maintenance of the airship at a constant height, and avoidance of the loss of gas consequent on expansion when the ship rises as it loses weight by the consumption of fuel. Owing to the great variation in temperature between day and night, the ship becomes heavy at night owing to the lower temperature, and light during the day, as a result of the higher temperature. A discharge of ballast at nightfall, and of gas in the morning, is needed to keep it in equilibrium. To obviate discharge of gas, and the necessity of starting with a large weight of ballast, it is proposed to run a proportion of the engines on hydrogen fuel, so that the hydrogen can be consumed at such a rate that the loss of lift equals the loss of weight of fuel consumed by the other engines, thus economically using hydrogen which otherwise would be lost through the discharge of the gas valves. I make the supposition that hydrogen, and not helium, will be the sustaining gas. For commercial aviation it has many advantages, for helium is dearer and rarer, and has about twenty per cent. less lift. Contrary to general belief, a flight in an airship filled with hydrogen, subject to proper precautions, has no greater fire risk than living near a gas factory. Helium is a necessity only for airships used in war, as, unlike hydrogen, it is not ignited by incendiary bullets from hostile aircraft. The United States has almost a monopoly of the world's quantitative supply of helium, which fact should be a tremendous asset in wartime. The ballast difficulty can be met by apparatus to condense the water of combustion from the exhaust gases of the engines. Experiments have shown that it is practicable to recover water of slightly greater weight than the gasoline fuel consumed, thus avoiding any variation in lift due to gasoline consumption. Further, water ballast could be picked up periodically from the sea by descending and taking in water through a pump suspended from a flexible hose, or direct into tanks in the gondolas through sea-valves. Still further reduction of running costs may be effected by fuel economy. This would be difficult with internal combustion engines of the type in use at present, for greater thermal efficiency (the ratio between the amount of heat contained in the fuel consumed and the amount of useful work delivered by the engine) necessitates heavier machinery. The reduction in gasoline consumption is thus offset by a decrease in the disposable lift. It is probable that a saving on large dirigibles might result from substituting for the internal combustion method of generating power engines that burn cheap oils. Although such engines are much heavier, and although the crude oils weigh a good deal more than gasoline, the difference would be more than covered on long flights, for gasoline is nearly four times dearer than crude oil. Moreover, the weight of oil actually consumed would be about twenty per cent. less than that of the gasoline burned by internal combustion engines over the same distance. The solution may be in the employment of steam. For the rather low standards of horsepower on which dirigibles are driven, heavy steam engines of the ordinary type, although much more reliable, would be less economical than internal combustion engines, owing to the latter's better thermal efficiency. Engineers are attempting to evolve a light type of steam turbine that will overcome this drawback. Of equal importance to fuel economy is a better system of airship navigation. This is similar in principle to steamship navigation, but it is made more complicated by the much greater drift of atmospheric currents. Moreover, air currents can never be charted as exactly as sea currents. An excellent meteorological organization, for reporting motions of the air at given times, is therefore essential. When flying over land a navigator can determine the drift of his vessel by taking observation on a suitable fixed point on the earth's surface, and adjusting his compass course accordingly. It is probable that a gyroscopic compass will be the standard type for dirigibles. Many aviators have experienced difficulties with the magnetic compass on long flights; although it has served me well always, especially on my transatlantic flight as Captain Alcock's navigator. Over the sea no fixed point is available, so that the motion of the wind must be checked periodically. One method is for the navigator to make astronomical observations, and from them deduce his position on the chart. Another may be the use of bombs which ignite on the water and give out a dense smoke or a bright light, lasting for several minutes. During the day the navigator sights on the smoke, and during the night on the light, and thus discovers the wind's velocity and direction. An invention that could simplify navigation would be some form of ground-speed meter, showing at a glance the rate of progress over the earth (as distinct from air speed), with either a following or a contrary wind. The most valuable means of airship navigation will be that of directional wireless. Communication from two separate stations, which could be either land terminals or stationary ships in the ocean, gives the direction of the transmitted wireless waves and signals to the dirigible its bearings. The position is then laid off on the chart, and the course regulated accordingly. This method was used by the German Zeppelins during the war. Of equal importance to the structural and navigational equipment of airships is the provision of suitable terminals for each route. These would require, among other necessities, an aërodrome of about one mile square; a double airship shed capable of housing two vessels; a mooring-out tower; mechanical gear for transferring an airship from the mooring tower to the shed; hydrogen generating and storage plant; repair workshops and stores; meteorological offices; wireless telegraphy installation; electrical night signaling and landing arrangements; a station on the local railway from the main part of the city; a hotel; a garage; and customs and booking offices. The aërodrome must be a short distance from the city served by the airship service. If possible it should be near a chemical works where hydrogen could be produced as a by-product. The ground would be preferably on a site remote from hills and other topographical features likely to cause air disturbances. The double sheds for housing vessels of the size specified, three million, five hundred thousand cubic feet capacity, would have two berths, the minimum dimensions of each of which must be eight hundred and fifty feet long, one hundred and fifty feet wide, and one hundred and fifteen feet high. Their contents should include hydrogen filling mains and gear for slinging the airships from the roof when deflated for overhaul. Special arrangements would be made for rapid replenishment of the ships with gas, fuel, and water ballast. If no industrial supply of hydrogen were provided by a nearby factory, the aërodrome should have a generating plant capable of producing fifty thousand cubic feet of hydrogen per hour. Gasometer storage, with a capacity of about five hundred thousand cubic feet, is also a necessity. The meteorological office would issue weather reports for the guidance of airship navigators, and issue navigating instructions to them by means of the wireless installation. The latter should have a range of at least five thousand miles. Each aërodrome would be provided with suitable electric light signals to indicate the position of the landing ground to incoming ships at night, as well as landing lights to point the way to the mooring tower. Trolleys running on guide rails, with electrically driven gear, could move a dirigible from the tower to the shed with a minimum of man power. A suitable mooring tower constitutes an enormous saving of time and labor. The Vickers Patent Mooring Gear, which has been tested satisfactorily, can be worked by half a dozen men; whereas the old method of rope pulling and dragging needs two to four hundred men for landing an airship of three million, five hundred thousand cubic feet capacity. With existing methods, a rigid airship must be housed in a suitable shed when not in flight. The danger and difficulty of removing the ship from its shed, and returning it safely thereto after a journey, restricts the number of actual flying days in the year to those on which such operations can be performed without risk of damage, although a modern rigid airship may be in the air with efficiency and perfect safety in practically any state of the weather. The Patent Mooring Gear renders the landing independent of the weather, while calling for the attendance of only six men to actuate the various mechanical devices employed. In principle, the gear consists of a tall steel mast, of such a height that when the ship is attached by the nose it rides on an even keel at a height of upwards of one hundred feet. The mast has at the top a platform or deck. The head of the tower is entirely enclosed and contains the necessary apparatus for bringing a vessel to rest. This top portion is designed to rotate, so that a ship, when moored, may always lie directly head to wind. Access to the upper deck of the masthead is obtained by means of an elevator, which allows passengers to enter the ship in comfort. Behind the deck is a compartment containing the landing gear. This consists of an electrically driven winding engine, fitted with about one thousand feet of the highest quality flexible steel wire rope, together with any automatic coupling. In the compartment are also pipes for the supply to the ship of hydrogen, gasoline, oil and water from the main reservoirs, situated on the ground at the foot of the mast. The vessel itself is fitted with apparatus complementary to that housed in the masthead. From the nose projects the attachment which is gripped by the automatic coupling, while in the bow is situated a storage drum and winch for six hundred feet of wire rope. On approaching the aërodrome, the ship wirelesses its intention to land. The masthead mooring rope is then threaded through the automatic coupling, and paid out until the free end reaches the ground below. This end of the rope is attached by a shackle to the rear of a light car, which is driven away from the mast in the direction from which the ship is approaching, while the rope uncoils from the drum above. When at a distance of seven hundred or eight hundred feet from the foot of the mast the men in charge of the gear unshackle the rope, and spread landing signs that indicate to the airship pilot their position on the ground. On arrival over the landing party, the ship's bow mooring rope is released, and runs out from the bow attachment under the influence of a weight of several hundred pounds in the form of sandbags. Two men of the party on the ground below take charge of the rope, unshackle the sandbags, and effect a junction with the mooring mast rope, which is in the hands of the remaining men of the landing party. The rope ends are coupled together by means of a self-locking coupling, which enables the junction to be made within five seconds. The dirigible is now connected with the head of the mooring mast by a long length of steel wire rope. On receiving a signal from the ground party, the men in charge of the winding gear in the masthead haul in. As the rope tautens, ballast is discharged from the ship, which is slowly hauled into connection with the automatic coupling already set in the open position to receive the attachment on the nose. When once this coupling is closed, the mooring ropes can be dispensed with, the ship's rope being re-wound on to the storage drum in the bows. After landing at the masthead, connection is made with the hydrogen, gasoline, oil, and water mains, and fresh gas, fuel and water ballast are placed on board, so that the ship may be kept in trim during the discharge of cargo, and so the embarkation of passengers and stores be effected. When all is ready to leave the masthead for flight, the pulling of a lever in the automatic coupling releases the ship. The latter then draws astern and upward, under the influence of the prevailing wind, until it is well clear of the landing station and can proceed on its course. The design of this apparatus is such that the landing of an airship is as easy in a wind as in complete calm. With its help an airship can land in any speed of wind in which it is safe to fly. Should the wind be so high (over 60 or 70 miles per hour) that the vessel cannot reach a given mast, it will always be possible to learn by wireless the nearest station at which favorable conditions allow it to come down. The release of the ship from the mast can take place in any wind-speed. Owing to the comparatively local nature of a big storm (storms are known not to cover districts greater than two hundred miles in diameter) the vessel, after slipping its moorings, is able to circumnavigate the disturbed area by making a small initial deviation from the true course. A part of the aërodrome should be given over to aëroplanes, used for the bringing of mails and urgent freight from places distant from the terminal. Heavier-than-air machines, in fact, will be the veins leading to the great arteries of the world's air routes, operated by dirigibles. A strong searchlight, for the guidance of aëroplane pilots flying in fog, might be necessary. Given improved landing facilities, means might be found for them to coast down the searchlight, if the ground away from it were invisible. Another method of delivering mails, before leaving for a landing ground away from the fog belt, is to drop them, attached to a parachute. When the package reaches earth it can be located by an electric bell, which rings on impact and continues ringing. The mail services of to-day, by railway and boat, can in many cases be greatly speeded up if part of a long journey be covered by aëroplane. A good instance is the route between Great Britain and South America. If a merchant in London posts three letters to correspondents in New York, Rio de Janeiro and Buenos Ayres respectively, he may have a reply from New York before the Brazil man has had time to read his communication, and four or five days before the man in the Argentine has received his. An aërial short cut to Dakar--already several machines have flown there from Paris--would lessen by six or seven days the transit time for mailbags sent from England to Rio de Janeiro or Buenos Ayres. As long as the internal combustion engine is used in aëronautics, and mechanical failure is always a possibility to be reckoned with, the cost of maintaining aëroplane routes, even if they be only auxiliary to dirigible or steamship services, will be greatly swollen by the need of maintaining frequent landing grounds. Every ten miles would be an ideal interval for them; every twenty miles is a minimum for first-rate insurance against risk. From a height of five thousand feet, the probable average minimum elevation for commercial air navigation, a pilot can without difficulty cover a distance of five miles while planing down without the aid of motors. From ten thousand feet he can cover ten miles under the same conditions; so that at this height he would never be outside gliding distance of landing grounds prepared every twenty miles. Given these safeguards, the element of risk in present day aviation is no greater than it was in the early days of railways and steamboats; and little, if any, greater than in modern motoring. Many people, possessing only a newspaper acquaintance with aërial affairs, still believe mechanical flight to be perilous. In exactly the same manner men shunned the infant steamboat, railway train, bicycle and motor-car. Yet, proportionately, the aëroplane and the dirigible are responsible for no more deaths than the train or the automobile. The seeming discrepancy is because so much attention is paid to air fatalities. Every week-end motor-car accidents cause scores of fatalities. Yet the death in harness of a single aviator produces more comment than all of these. Partly, no doubt, the intense horror with which humanity regards death by falling from a great height is due to its novelty among human experiences. The airways of the world offer some pretty problems of international politics, involving commerce, rights of landing, customs duties, air smuggling, air traffic regulations and air laws. All these were dealt with in the International Aërial Commission at the Peace Conference, which agreed upon the following principles: 1. Recognition of the greatest possible freedom of aërial navigation, as far as that freedom of navigation is reconcilable with the principle of the sovereignty of each state in the air above its territory, with the security of the state affected, and in conformity with a strict enforcement of safety regulations. 2. Regulation under obligatory permits for pilots and other aëronautical personnel to be recognized mutually by the signatory states. 3. The establishment of international air rules, including signals, lights, methods of avoiding collisions and regulations for landing. 4. The recognition of the special treatment of army, navy and state machines when on duty for the state. 5. Recognition of the right to utilize all public aërodromes in other states, under a charge to be uniform for the aircraft of all nations, including the home nation. 6. Recognition of the right of crossing one country to another, with the privilege of landing, but under the reservation of the right of the state crossed to apply its local rules, and if necessary to force the landing of the visiting machines on signal. 7. Recognition of the principle of mutual indemnity to cover damages to persons or property due to aircraft--the state of the offending machine to make reparation and then to recoup itself in any way it sees fit. 8. Recognition of the necessity of a permanent international aëronautical commission, in order to keep the development of the legal side of aviation abreast of the development of the science itself. 9. Recognition of the obligation of each state to regulate its internal legislation along the lines of the clauses of the international agreement. The main airways of the world are still hypothetical, but some of their main terminals, in relation to the centers of industry and population and the trade routes, will certainly be London, New York, San Francisco, Tokio, Delhi, Colombo, Cairo, Cape Town, and Rio de Janeiro. In particular London, New York, Cairo and Rio de Janeiro are fitted to be great junctions for air traffic. London is the logical distribution center for passengers and freight from North and South America bound for Continental Europe or the East. The New York terminal should link the transatlantic airways from Europe with the airways of North America. Rio de Janeiro should perform the same function for South America, and also be the center of seaplane traffic up the Amazon. Cairo is destined to be the junction for the air routes between Europe, Asia, Africa and Australia. From it dirigibles or aëroplanes may pass to India (via Damascus and Bagdad), to Cape Town (via Nairobi), to Australia (via Aden and Colombo, or Delhi and Singapore), and to London (via Algiers or some point in Southern Italy). Cairo is also likely to be an important base for seaplanes and flying boats plying up and down the tremendous waterways of the Nile and the Great Lakes. The British Empire is especially bound up with the airways of the future. The geographical position of the Briton forces him to think in Imperial terms. In 1776 Great Britain lost her most valuable colonies largely because the Atlantic Ocean made adequate representation of the colonial interest physically impossible. Since that day cables, steamships and the wireless have helped to overcome the distances that separate the overseas dominions from the British Isles. Aircraft and well-organized British air routes should be the greatest step in the consolidation of the far-flung Empire. To this end British official experts mapped out the stages of the aërial route to Australia from Egypt, via Damascus, Bagdad, Karachi, Delhi, Calcutta, Singapore and Sumatra. Although the successive landing grounds were not ready in time for Captain Ross-Smith's magnificent flight from England to Australia, the information and advice collected by the official surveyors were of inestimable value to him. It is noteworthy that nearly the whole of the proposed airway from Egypt to Australia is over British territory or the sea. The same is true of the proposed route from Cairo to Cape Town. This was planned out very carefully by three parties of military aviators, who covered the whole length of civilized and uncivilized Africa in their search for landing grounds. The absorption of German East Africa by the South African Union makes an all British corridor for aircraft from Cairo to Cape Town, by way of Egypt, the Sudan, British East Africa, British Central Africa, German East Africa, Rhodesia, the Transvaal and Cape Colony. There is an alternative water route over the Nile, the Great Lakes, the Zambezi River and along the coast to Cape Town. Being the junction of the airways to India, Australia and South Africa, Egypt is destined to be the nerve center of an air-linked British Empire, just as the Suez Canal has been its jugular vein. But the laying out of great air routes to the East and South does not complete Britain's plans. She must connect them up with London--a task which is much more complicated from the standpoint of high politics, because it involves routes over the territory of other nations. An aëroplane can fly from London to Cairo via Gibraltar without passing over foreign territory or foreign territorial waters. But the air route would be long and the aërodrome bases great distances apart, in comparison with the proposed land route of two thousand miles across France, down the length of Italy and Greece and across the Mediterranean to Cairo. Such a route necessitates an entente cordiale with the nations of Western Europe, and is one of the reasons why Great Britain can never contemplate easily a loosening of the bonds that now hold together the Allies of Western Europe. The French, for their part, are also thinking of air routes in terms of their colonial possessions. For them the international situation is much the same as for the London-Cairo airway. French pilots need not fly over foreign territory to Algiers or Morocco. A long flight across the Mediterranean, or skirting the west coast of Spain, is a possibility. But Spanish territory is the logical corridor from France to Africa. It was over Spain that a trip was made from Toulouse to Casablanca, the eighteen hundred miles being covered in eleven hours of actual flying. The ordinary postal service takes six days. For direct aërial communication with Syria, also, France must have an entente with several intervening countries. Not only will the aëroplane connect France more closely with Africa; it will likewise bind together the various sections of France's colonial territory in Africa, The Sahara Desert will become a less formidable obstacle to intercommunication. French pilots have made experimental flights over parts of the Sahara in a search for the best routes and landing places, as links in communication between Morocco and the Ivory Coast. When technical progress and perfected organization place the world's main airways in operation, there will be enormous saving of time on the longer routes. The estimated time for transatlantic flights from London to New York by the three million, five hundred thousand cubic feet dirigibles is two to two and one-half days, Other likely figures for various services are as follows: _London to India and Australia_: London to Cairo 2,050 miles Cairo to Colombo (via Aden) 3,400 miles Colombo to Perth (Australia) 3,150 miles At an average speed of sixty miles per hour, and with a stop of twelve hours at each station for re-fueling, the times taken would be London to Cairo 34 hours, or 1-1/2 days London to Colombo 34 + 12 + 58 hours = 104 hours, or 4-1/2 days By train and mail steamer, the journey to Ceylon at present takes fifteen days, and to Australia over thirty days. _Cairo to Cape Town_: Cairo to British East Africa (Nairobi) 2,100 miles--35 hours Nairobi to Cape Town 2,200 miles--37 hours Total time from Cairo to Cape Town, allowing for a break of twelve hours at Nairobi 84 hours Owing to variation in the weather conditions, latitude in estimating the time of arrival must be permitted in each case. Where, however, there is a saving of several days in comparison with steamship travel, the difference of a few hours matters little. In years to come, with the development of airship transport to the most distant centers of the world, it is conceivable that no important city will be further from London than ten days' journey. The following table, as applied to a London terminal, is by no means fantastic: To New York 2--2-1/2 days " San Francisco 4-1/2 days " Cairo 1-1/2 days " Colombo 4-1/2 days " Perth 7 days " Nairobi 3-1/2 days " Cape Town 5-1/2 days " Rio de Janeiro 4 days As the maximum distance of direct flight between intermediate stations is not more than three thousand, five hundred miles, it would be practicable to run these services with the size of airship described three million, five hundred thousand cubic feet capacity. The cost of operation for regular services would be approximately as for the Atlantic service--passengers at the rate of eight cents per mile, and mails at the rate of six cents per ounce. With the development of larger airships, carrying greater loads, the cost should be more economical. I admit that such a near-Utopia of an air age may not be seen by the present decade, and that its attainment demands great results from science, statesmanship and business organization. Yet even to come within sight of world intercommunication as rapid as is indicated by the signposts of present-day aëronautics would make possible an era of greater prosperity, peace and friendliness. If people, their written communications and their goods can be taken from continent to continent as quickly, or nearly as quickly, as a cablegram, the twin evils of state parochialism and international misunderstanding will less often be dragged from the cupboard in which the world's racial skeletons are kept. The airship and the aëroplane may well become a greater influence towards internationalization than the signed covenant of the league of nations. Transcriber's Note: Small capitals have been rendered in full capitals. Italics are indicated by _underscores_. Footnotes are placed at the end of chapters. Apparent typographical errors have been corrected. 
777	----	THE MASTERY OF THE AIR By William J. Claxton PREFACE This book makes no pretence of going minutely into the technical and scientific sides of human flight: rather does it deal mainly with the real achievements of pioneers who have helped to make aviation what it is to-day. My chief object has been to arouse among my readers an intelligent interest in the art of flight, and, profiting by friendly criticism of several of my former works, I imagine that this is best obtained by setting forth the romance of triumph in the realms of an element which has defied man for untold centuries, rather than to give a mass of scientific principles which appeal to no one but the expert. So rapid is the present development of aviation that it is difficult to keep abreast with the times. What is new to-day becomes old to-morrow. The Great War has given a tremendous impetus to the strife between the warring nations for the mastery of the air, and one can but give a rough and general impression of the achievements of naval and military airmen on the various fronts. Finally, I have tried to bring home the fact that the fascinating progress of aviation should not be confined entirely to the airman and constructor of air-craft; in short, this progress is not a record of events in which the mass of the nation have little personal concern, but of a movement in which each one of us may take an active and intelligent part. I have to thank various aviation firms, airmen, and others who have kindly come to my assistance, either with the help of valuable information or by the loan of photographs. In particular, my thanks are due to the Royal Flying Corps and Royal Naval Air Service for permission to reproduce illustrations from their two publications on the work and training of their respective corps; to the Aeronautical Society of Great Britain; to Messrs. C. G. Spencer & Sons, Highbury; The Sopwith Aviation Company, Ltd.; Messrs. A. V. Roe & Co., Ltd.; The Gnome Engine Company; The Green Engine Company; Mr. A. G. Gross (Geographia, Ltd.); and M. Bleriot; for an exposition of the internal-combustion engine I have drawn on Mr. Horne's The Age of Machinery. PART I. BALLOONS AND AIR-SHIPS I. MAN'S DUEL WITH NATURE II. THE FRENCH PAPER-MAKER WHO INVENTED THE BALLOON III. THE FIRST MAN TO ASCEND IN A BALLOON IV. THE FIRST BALLOON ASCENT IN ENGLAND V. THE FATHER OF BRITISH AERONAUTS VI. THE PARACHUTE VII. SOME BRITISH INVENTORS OF AIR-SHIPS VIII. THE FIRST ATTEMPTS TO STEER A BALLOON IX. THE STRANGE CAREER OF COUNT ZEPPELIN X. A ZEPPELIN AIR-SHIP AND ITS CONSTRUCTION XI. THE SEMI-RIGID AIR-SHIP XII. A NON-RIGID BALLOON XIII. THE ZEPPELIN AND GOTHA RAIDS PART II. AEROPLANES AND AIRMEN XIV. EARLY ATTEMPTS IN AVIATION XV. A PIONEER IN AVIATION XVI. THE "HUMAN BIRDS" XVII. THE AEROPLANE AND THE BIRD XVIII. A GREAT BRITISH INVENTOR OF AEROPLANES XIX. THE WRIGHT BROTHERS AND THEIR SECRET EXPERIMENTS XX. THE INTERNAL-COMBUSTION ENGINE XXI. THE INTERNAL-COMBUSTION ENGINE (Con't.) XXII. THE AEROPLANE ENGINE XXIII. A FAMOUS BRITISH INVENTOR OF AVIATION ENGINES XXIV. THE WRIGHT BIPLANE (CAMBER OF PLANES) XXV. THE WRIGHT BIPLANE (Cont.) XXVI. HOW THE WRIGHTS LAUNCHED THEIR BIPLANE XXVII. THE FIRST MAN TO FLY IN EUROPE XXVIII. M. BLARIOT AND THE MONOPLANE XXIX. HENRI FARMAN AND THE VOISIN BIPLANE XXX. A FAMOUS BRITISH INVENTOR XXXI. THE ROMANCE OF A COWBOY AERONAUT XXXII. THREE HISTORIC FLIGHTS XXXIII. THREE HISTORIC FLIGHTS (Cont.) XXXIV. THE HYDROPLANE AND AIR-BOAT XXXV. A FAMOUS BRITISH INVENTOR OF THE WATER-PLANE XXXVI. SEA-PLANES FOR WARFARE XXXVII. THE FIRST MAN TO FLY IN BRITAIN XXXVIII.THE R.F.C. AND R.N.A.S. XXXIX. AEROPLANES IN THE GREAT WAR XL. THE ATMOSPHERE AND THE BAROMETER XLI. HOW AN AIRMAN KNOWS WHAT HEIGHT HE REACHES XLII. HOW AN AIRMAN FINDS HIS WAY XLIII. THE FIRST AIRMAN TO FLY UPSIDE DOWN XLIV. THE FIRST ENGLISHMAN TO FLY UPSIDE DOWN XLV. ACCIDENTS AND THEIR CAUSE XLVI. ACCIDENTS AND THEIR CAUSE (Cont.) XLVII. ACCIDENTS AND THEIR CAUSE (COnt.) XLVIII. SOME TECHNICAL TERMS USED By AVIATORS XLIX. THE FUTURE IN THE AIR THE MASTERY OF THE AIR PART I. BALLOONS AND AIR-SHIPS CHAPTER I. Man's Duel with Nature Of all man's great achievements none is, perhaps, more full of human interest than are those concerned with flight. We regard ourselves as remarkable beings, and our wonderful discoveries in science and invention induce us to believe we are far and away the cleverest of all the living creatures in the great scheme of Creation. And yet in the matter of flight the birds beat us; what has taken us years of education, and vast efforts of intelligence, foresight, and daring to accomplish, is known by the tiny fledglings almost as soon as they come into the world. It is easy to see why the story of aviation is of such romantic interest. Man has been exercising his ingenuity, and deliberately pursuing a certain train of thought, in an attempt to harness the forces of Nature and compel them to act in what seems to be the exact converse of Nature's own arrangements. One of the mysteries of Nature is known as the FORCE OF GRAVITY. It is not our purpose in this book to go deeply into a study of gravitation; we may content ourselves with the statement, first proved by Sir Isaac Newton, that there is an invisible force which the Earth exerts on all bodies, by which it attracts or draws them towards itself. This property does not belong to the Earth alone, but to all matter--all matter attracts all other matter. In discussing the problems of aviation we are concerned mainly with the mutual attraction of The Earth and the bodies on or near its surface; this is usually called TERRESTRIAL gravity. It has been found that every body attracts very other body with a force directly proportionate to its mass. Thus we see that, if every particle in a mass exerts its attractive influence, the more particles a body contains the greater will be the attraction. If a mass of iron be dropped to the ground from the roof of a building at the same time as a cork of similar size, the iron and the cork would, but for the retarding effect of the air, fall to the ground together, but the iron would strike the ground with much greater force than the cork. Briefly stated, a body which contains twice as much matter as another is attracted or drawn towards the centre of the Earth with twice the force of that other; if the mass be five times as great, then it will be attracted with five times the force, and so on. It is thus evident that the Earth must exert an overwhelming attractive force on all bodies on or near its surface. Now, when man rises from the ground in an aeroplane he is counter-acting this force by other forces. A short time ago the writer saw a picture which illustrated in a very striking manner man's struggle with Nature. Nature was represented as a giant of immense stature and strength, standing on a globe with outstretched arms, and in his hands were shackles of great size. Rising gracefully from the earth, immediately in front of the giant, was an airman seated in a modern flying-machine, and on his face was a happy-go-lucky look as though he were delighting in the duel between him and the giant. The artist had drawn the picture so skilfully that one could imagine the huge, knotted fingers grasping the shackles were itching to bring the airman within their clutch. The picture was entitled "MAN TRIUMPHANT" No doubt many of those who saw that picture were reminded of the great sacrifices made by man in the past. In the wake of the aviator there are many memorial stones of mournful significance. It says much for the pluck and perseverance of aviators that they have been willing to run the great risks which ever accompany their efforts. Four years of the Great War have shown how splendidly airmen have risen to the great demands made upon them. In dispatch after dispatch from the front, tribute has been paid to the gallant and devoted work of the Royal Flying Corps and the Royal Naval Air Service. In a long and bitter struggle British airmen have gradually asserted their supremacy in the air. In all parts of the globe, in Egypt, in Mesopotamia, in Palestine, in Africa, the airman has been an indispensable adjunct of the fighting forces. Truly it may be said that mastery of the air is the indispensable factor of final victory. CHAPTER II. The French Paper-maker who Invented the Balloon In the year 1782 two young Frenchmen might have been seen one winter night sitting over their cottage fire, performing the curious experiment of filling paper bags with smoke, and letting them rise up towards the ceiling. These young men were brothers, named Stephen and Joseph Montgolfier, and their experiments resulted in the invention of the balloon. The brothers, like all inventors, seem to have had enquiring minds. They were for ever asking the why and the wherefore of things. "Why does smoke rise?" they asked. "Is there not some strange power in the atmosphere which makes the smoke from chimneys and elsewhere rise in opposition to the force of gravity? If so, cannot we discover this power, and apply it to the service of mankind?" We may imagine that such questions were in the minds of those two French paper-makers, just as similar questions were in the mind of James Watt when he was discovering the power of steam. But one of the most important attributes of an inventor is an infinite capacity for taking pains, together with great patience. And so we find the two brothers employing their leisure in what to us would, be a childish pastime, the making of paper balloons. The story tells us that their room was filled with smoke, which issued from the windows as though the house were on fire. A neighbour, thinking such was the case, rushed in, but, on being assured that nothing serious was wrong, stayed to watch the tiny balloons rise a little way from the thin tray which contained the fire that made the smoke with which the bags were filled. The experiments were not altogether successful, however, for the bags rarely rose more than a foot or so from the tray. The neighbour suggested that they should fasten the thin tray on to the bottom of the bag, for it was thought that the bags would not ascend higher because the smoke became cool; and if the smoke were imprisoned within the bag much better results would be obtained. This was done, and, to the great joy of the brothers and their visitor, the bag at once rose quickly to the ceiling. But though they could make the bags rise their great trouble was that they did not know the cause of this ascent. They thought, however, that they were on the eve of some great discovery, and, as events proved, they were not far wrong. For a time they imagined that the fire they had used generated some special gas, and if they could find out the nature of this gas, and the means of making it in large quantities, they would be able to add to their success. Of course, in the light of modern knowledge, it seems strange that the brothers did not know that the reason the bags rose, was not because of any special gas being used, but owing to the expansion of air under the influence of heat, whereby hot air tends to rise. Every schoolboy above the age of twelve knows that hot air rises upwards in the atmosphere, and that it continues to rise until its temperature has become the same as that of the surrounding air. The next experiment was to try their bags in the open air. Choosing a calm, fine day, they made a fire similar to that used in their first experiments, and succeeded in making the bag rise nearly 100 feet. Later on, a much larger craft was built, which was equally successful. And now we must leave the experiments of the Montgolfiers for a moment, and turn to the discovery of hydrogen gas by Henry Cavendish, a well-known London chemist. In 1766 Cavendish proved conclusively that hydrogen gas was not more than one-seventh the weight of ordinary air. It at once occurred to Dr. Black, of Glasgow, that if a thin bag could be filled with this light gas it would rise in the air; but for various reasons his experiments did not yield results of a practical nature for several years. Some time afterwards, about a year before the Montgolfiers commenced their experiments which we have already described, Tiberius Cavallo, an Italian chemist, succeeded in making, with hydrogen gas, soap-bubbles which rose in the air. Previous to this he had experimented with bladders and paper bags; but the bladders he found too heavy, and the paper too porous. It must not be thought that the Montgolfiers experimented solely with hot air in the inflation of their balloons. At one time they used steam, and, later on, the newly-discovered hydrogen gas; but with both these agents they were unsuccessful. It can easily be seen why steam was of no use, when we consider that paper was employed; hydrogen, too, owed its lack of success to the same cause for the porosity of the paper allowed the gas to escape quickly. It is said that the name "balloon" was given to these paper craft because they resembled in shape a large spherical vessel used in chemistry, which was known by that name. To the brothers Montgolfier belongs the honour of having given the name to this type of aircraft, which, in the two succeeding centuries, became so popular. After numerous experiments the public were invited to witness the inflation of a particularly huge balloon, over 30 feet in diameter. This was accomplished over a fire made of wool and straw. The ascent was successful, and the balloon, after rising to a height of some 7000 feet, fell to earth about two miles away. It may be imagined that this experiment aroused enormous interest in Paris, whence the news rapidly spread over all France and to Britain. A Parisian scientific society invited Stephen Montgolfier to Paris in order that the citizens of the metropolis should have their imaginations excited by seeing the hero of these remarkable experiments. Montgolfier was not a rich man, and to enable him to continue his experiments the society granted him a considerable sum of money. He was then enabled to construct a very fine balloon, elaborately decorated and painted, which ascended at Versailles in the presence of the Court. To add to the value of this experiment three animals were sent up in a basket attached to the balloon. These were a sheep, a cock, and a duck. All sorts of guesses were made as to what would be the fate of the "poor creatures". Some people imagined that there was little or no air in those higher regions and that the animals would choke; others said they would be frozen to death. But when the balloon descended the cock was seen to be strutting about in his usual dignified way, the sheep was chewing the cud, and the duck was quacking for water and worms. At this point we will leave the work of the brothers Montgolfier. They had succeeded in firing the imagination of nearly every Frenchman, from King Louis down to his humblest subject. Strange, was it not, though scores of millions of people had seen smoke rise, and clouds float, for untold centuries, yet no one, until the close of the eighteenth century, thought of making a balloon? The learned Franciscan friar, Roger Bacon, who lived in the thirteenth century, seems to have thought of the possibility of producing a contrivance that would float in air. His idea was that the earth's atmosphere was a "true fluid", and that it had an upper surface as the ocean has. He quite believed that on this upper surface--subject, in his belief, to waves similar to those of the sea--an air-ship might float if it once succeeded in rising to the required height. But the difficulty was to reach the surface of this aerial sea. To do this he proposed to make a large hollow globe of metal, wrought as thin as the skill of man could make it, so that it might be as light as possible, and this vast globe was to be filled with "liquid fire". Just what "liquid fire" was, one cannot attempt to explain, and it is doubtful if Bacon himself had any clear idea. But he doubtless thought of some gaseous substance lighter than air, and so he would seem to have, at least, hit upon the principle underlying the construction of the modern balloon. Roger Bacon had ideas far in advance of his time, and his experiments made such an impression of wonder on the popular mind that they were believed to be wrought by black magic, and the worthy monk was classed among those who were supposed to be in league with Satan. CHAPTER III. The First Man to Ascend in a Balloon The safe descent of the three animals, which has already been related, showed the way for man to venture up in a balloon. In our time we marvel at the daring of modern airmen, who ascend to giddy heights, and, as it were, engage in mortal combat with the demons of the air. But, courageous though these deeds are, they are not more so than those of the pioneers of ballooning. In the eighteenth century nothing was known definitely of the conditions of the upper regions of the air, where, indeed, no human being had ever been; and though the frail Montgolfier balloons had ascended and descended with no outward happenings, yet none could tell what might be the risk to life in committing oneself to an ascent. There was, too, very special danger in making an ascent in a hot-air balloon. Underneath the huge envelope was suspended a brazier, so that the fabric of the balloon was in great danger of catching fire. It was at first suggested that two French criminals under sentence of death should be sent up, and, if they made a safe descent, then the way would be open for other aeronauts to venture aloft. But everyone interested in aeronautics in those days saw that the man who first traversed the unexplored regions of the air would be held in high honour, and it seemed hardly right that this honour should fall to criminals. At any rate this was the view of M. Pilatre de Rozier, a French gentleman, and he determined himself to make the pioneer ascent. De Rozier had no false notion of the risks he was prepared to run, and he superintended with the greatest care the construction of his balloon. It was of enormous size, with a cage slung underneath the brazier for heating the air. Befors making his free ascent De Rozier made a trial ascent with the balloon held captive by a long rope. At length, in November, 1783, accompanied by the Marquis d'Arlandes as a passenger, he determined to venture. The experiment aroused immense excitement all over France, and a large concourse of people were gathered together on the outskirts of Paris to witness the risky feat. The balloon made a perfect ascent, and quickly reached a height of about half a mile above sea-level. A strong current of air in the upper regions caused the balloon to take an opposite direction from that intended, and the aeronauts drifted right over Paris. It would have gone hard with them if they had been forced to descend in the city, but the craft was driven by the wind to some distance beyond the suburbs and they alighted quite safely about six miles from their starting-point, after having been up in the air for about half an hour. Their voyage, however, had by no means been free from anxiety. We are told that the fabric of the balloon repeatedly caught fire, which it took the aeronauts all their time to extinguish. At times, too, they came down perilously near to the Seine, or to the housetops of Paris, but after the most exciting half-hour of their lives they found themselves once more on Mother Earth. Here we must make a slight digression and speak of the invention of the hydrogen, or gas, balloon. In a previous chapter we read of the discovery of hydrogen gas by Henry Cavendish, and the subsequent experiments with this gas by Dr. Black, of Glasgow. It was soon decided to try to inflate a balloon with this "inflammable air"--as the newly-discovered gas was called--and with this end in view a large public subscription was raised in France to meet the heavy expenses entailed in the venture. The work was entrusted to a French scientist, Professor Charles, and two brothers named Robert. It was quickly seen that paper, such as was used by the Montgolfiers, was of little use in the construction of a gas balloon, for the gas escaped. Accordingly the fabric was made of silk and varnished with a solution of india-rubber and turpentine. The first hydrogen balloon was only about 13 feet in diameter, for in those early days the method of preparing hydrogen was very laborious and costly, and the constructors thought it advisable not to spend too much money over the initial experiments, in case they should be a failure. In August, 1783--an eventful year in the history of aeronautics--the first gas-inflated balloon was sent up, of course unaccompanied by a passenger. It shot up high in the air much more rapidly than Montgolfier's hot-air balloon had done, and was soon beyond the clouds. After a voyage of nearly an hour's duration it descended in a field some 15 miles away. We are told that some peasants at work near by fled in the greatest alarm at this strange monster which settled in their midst. An old print shows them cautiously approaching the balloon as it lay heaving on the ground, stabbing it with pitchforks, and beating it with flails and sticks. The story goes that one of the alarmed farmers poured a charge of shot into it with his gun, no doubt thinking that he had effectually silenced the panting demon contained therein. To prevent such unseemly occurrences in the future the French Government found it necessary to warn the people by proclamation that balloons were perfectly harmless objects, and that the experiments would be repeated. We now have two aerial craft competing for popular favour: the Montgolfier hot-air balloon and the "Charlier" or gas-inflated balloon. About four months after the first trial trip of the latter the inventors decided to ascend in a specially-constructed hydrogen-inflated craft. This balloon, which was 27 feet in diameter, contained nearly all the features of the modern balloon. Thus there was a valve at the top by means of which the gas could be let out as desired; a cord net covered the whole fabric, and from the loop which it formed below the neck of the balloon a car was suspended; and in the car there was a quantity of ballast which could be cast overboard when necessary. It may be imagined that this new method of aerial navigation had thoroughly aroused the excitability of the French nation, so that thousands of people were met together just outside Paris on the 17th December to see Professor Charles and his mechanic, Robelt, ascend in their new craft. The ascent was successful in every way; the intrepid aeronauts, who carried a barometer, found that they had quickly reached an altitude of over a mile. After remaining aloft for nearly two hours they came down. Professor Charles decided to ascend again, this time by himself, and with a much lighter load the balloon rose about two miles above sea-level. The temperature at this height became very low, and M. Charles was affected by violent pain in his right ear and jaw. During the voyage he witnessed the strange phenomenon of a double sunset; for, before the ascent, the sun had set behind the hills overshadowing the valleys, and when he rose above the hill-tops he saw the sun again, and presently saw it set again. There is no doubt that the balloon would have risen several thousand feet higher, but the professor thought it would burst, and he opened the valve, eventually making a safe descent about 7 miles from his starting-place. England lagged behind her French neighbour's in balloon aeronautics--much as she has recently done in aviation--for a considerable time, and, it was not till August of the following year (1784) that the first balloon ascent was made in Great Britain, by Mr. J. M. Tytler. This took place at Edinburgh in a fire balloon. Previous to this an Italian, named Lunardi, had in November, 1783, dispatched from the Artillery Ground, in London, a small balloon made of oil-silk, 10 feet in diameter and weighing 11 pounds. This small craft was sent aloft at one o'clock, and came down, about two and a half hours later, in Sussex, about 48 miles from its starting-place. In 1784 the largest balloon on record was sent up from Lyons. This immense craft was more than 100 feet in diameter, and stood about 130 feet high. It was inflated with hot air over a straw fire, and seven passengers were carried, including Joseph Montgolfier and Pilatre de Rozier. But to return to de Rozier, whom we left earlier in the chapter, after his memorable ascent near Paris. This daring Frenchman decided to cross the Channel, and to prevent the gas cooling, and the balloon falling into the sea, he hit on the idea of suspending a small fire balloon under the neck of another balloon inflated with hydrogen gas. In the light of our modern knowledge of the highly-inflammable nature of hydrogen, we wonder how anyone could have attempted such an adventure; but there had been little experience of this newly-discovered gas in those days. We are not surprised to read that, when high in the air, there was an awful explosion and the brave aeronaut fell to the earth and was dashed to death. CHAPTER IV. The First Balloon Ascent in England It has been said that the honour of making the first ascent in a balloon from British soil must be awarded to Mr. Tytler. This took place in Scotland. In this chapter we will relate the almost romantic story of the first ascent made in England. This was carried out successfully by Lunardi, the Italian of whom we have previously spoken. This young foreigner, who was engaged as a private secretary in London, had his interest keenly aroused by the accounts of the experiments being carried out in balloons in France, and he decided to attempt similar experiments in this country. But great difficulties stood in his way. Like many other inventors and would-be airmen, he suffered from lack of funds to build his craft, and though people whom he approached for financial aid were sympathetic, many of them were unwilling to subscribe to his venture. At length, however, by indomitable perseverance, he collected enough money to defray the cost of building his balloon, and it was arranged that he should ascend from the Artillery Ground, London, in September, 1784. His craft was a "Charlier"--that is, it was modelled after the hydrogen-inflated balloon built by Professor Charles--and it resembled in shape an enormous pear. A wide hoop encircled the neck of the envelope, and from this hoop the car was suspended by stout cordage. It is said that on the day announced for the ascent a crowd of nearly 200,000 had assembled, and that the Prince of Wales was an interested spectator. Farmers and labourers and, indeed, all classes of people from the prince down to the humblest subject, were represented, and seldom had London's citizens been more deeply excited. Many of them, however, were incredulous, especially when an insufficiency of gas caused a long delay before the balloon could be liberated. Fate seemed to be thwarting the plucky Italian at every step. Even at the last minute, when all arrangements had been perfected as far as was humanly possible, and the crowd was agog with excitement, it appeared probable that he would have to postpone the ascent. It was originally intended that Lunardi should be accompanied by a passenger; but as there was a shortage of gas the balloon's lifting power was considerably lessened, and he had to take the trip with a dog and cat for companions. A perfect ascent was made, and in a few moments the huge balloon was sailing gracefully in a northerly direction over innumerable housetops. This trip was memorable in another way. It was probably the only aerial cruise where a Royal Council was put off in order to witness the flight. It is recorded that George the Third was in conference with the Cabinet, and when news arrived in the Council Chamber that Lunardi was aloft, the king remarked: "Gentlemen, we may resume our deliberations at pleasure, but we may never see poor Lunardi again!" The journey was uneventful; there was a moderate northerly breeze, and the aeronaut attained a considerable altitude, so that he and his animals were in danger of frost-bite. Indeed, one of the animals suffered so severely from the effects of the cold that Lunardi skilfully descended low enough to drop it safely to earth, and then, throwing out ballast, once more ascended. He eventually came to earth near a Hertfordshire village about 30 miles to the north of London. CHAPTER V. The Father of British Aeronauts No account of the early history of English aeronautics could possibly be complete unless it included a description of the Nassau balloon, which was inflated by coal-gas, from the suggestion of Mr. Charles Green, who was one of Britain's most famous aeronauts. Because of his institution of the modern method of using coal-gas in a balloon, Mr. Green is generally spoken of as the Father of British Aeronautics. During the close of the eighteenth and the opening years of the nineteenth century there had been numerous ascents in Charlier balloons, both in Britain and on the Continent. It had already been discovered that hydrogen gas was highly dangerous and also expensive, and Mr. Green proposed to try the experiment of inflating a balloon with ordinary coal-gas, which had now become fairly common in most large towns, and was much less costly than hydrogen. Critics of the new scheme assured the promoters that coal-gas would be of little use for a balloon, averring that it had comparatively little lifting power, and aeronauts could never expect to rise to any great altitude in such a balloon. But Green firmly believed that his theory was practical, and he put it to the test. The initial experiments quite convinced him that he was right. Under his superintendence a fine balloon about 80 feet high, built of silk, was made in South London, and the car was constructed to hold from fifteen to twenty passengers. When the craft was completed it was proposed to send it to Paris for exhibition purposes, and the inventor, with two friends, Messrs. Holland and Mason, decided to take it over the Channel by air. It is said that provisions were taken in sufficient quantities to last a fortnight, and over a ton of ballast was shipped. The journey commenced in November, 1836, late in the afternoon, as the aeronauts had planned to cross the sea by night. A fairly strong north-west wind quickly bore them to the coast, and in less than an hour they found themselves over the lights of Calais. On and on they went, now and then entirely lost to Earth through being enveloped in dense fog; hour after hour went by, until at length dawn revealed a densely-wooded tract of country with which they were entirely unfamiliar. They decided to land, and they were greatly surprised to find that they had reached Weilburg, in Nassau, Germany. The whole journey of 500 miles had been made in eighteen hours. Probably no British aeronaut has made more daring and exciting ascents than Mr. Green--unless it be a member of the famous Spencer family, of whom we speak in another chapter. It is said that Mr. Green went aloft over a thousand times, and in later years he was accompanied by various passengers who were making ascents for scientific purposes. His skill was so great that though he had numerous hairbreadth escapes he seldom suffered much bodily harm. He lived to the ripe old age of eighty-five. CHAPTER VI. The Parachute No doubt many of those who read this book have seen an aeronaut descend from a balloon by the aid of a parachute. For many years this performance has been one of the most attractive items on the programmes of fetes, galas, and various other outdoor exhibitions. The word "parachute" has been almost bodily taken from the French language. It is derived from the French parer to parry, and chute a fall. In appearance a parachute is very similar to an enormous umbrella. M. Blanchard, one of the pioneers of ballooning, has the honour of first using a parachute, although not in person. The first "aeronaut" to descend by this apparatus was a dog. The astonished animal was placed in a basket attached to a parachute, taken up in a balloon, and after reaching a considerable altitude was released. Happily for the dog the parachute acted quite admirably, and the animal had a graceful and gentle descent. Shortly afterwards a well-known French aeronaut, M. Garnerin, had an equally satisfactory descent, and soon the parachute was used by most of the prominent aeronauts of the day. Mr. Cocking, a well-known balloonist, held somewhat different views from those of other inventors as to the best form of construction of parachutes. His idea was that a parachute should be very large and rather heavy in order to be able to support a great weight. His first descent from a great height was also his last. In 1837, accompanied by Messrs. Spencer and Green, he went up with his parachute, attached to the Nassau balloon. At a height of about a mile the parachute was liberated, but it failed to act properly; the inventor was cast headlong to earth, and dashed to death. From time to time it has been thought that the parachute might be used for life-saving on the modern dirigible air-ship, and even on the aeroplane, and experiments have been carried out with that end in view. A most thrilling descent from an air-ship by means of a parachute was that made by Major Maitland, Commander of the British Airship Squadron, which forms part of the Royal Flying Corps. The descent took place from the Delta air-ship, which ascended from Farnborough Common. In the car with Major Maitland were the pilot, Captain Waterlow, and a passenger. The parachute was suspended from the rigging of the Delta, and when a height of about 2000 feet had been reached it was dropped over to the side of the car. With the dirigible travelling at about 20 miles an hour the major climbed over the car and seated himself in the parachute. Then it became detached from the Delta and shot downwards for about 200 feet at a terrific rate. For a moment or two it was thought that the opening apparatus had failed to work; but gradually the "umbrella" opened, and the gallant major had a gentle descent for the rest of the distance. This experiment was really made in order to prove the stability of an air-ship after a comparatively great weight was suddenly removed from it. Lord Edward Grosvenor, who is attached to the Royal Flying Corps, was one of the eyewitnesses of the descent. In speaking of it he said: "We all think highly of Major Maitland's performance, which has shown how the difficulty of lightening an air-ship after a long flight can be surmounted. During a voyage of several hours a dirigible naturally loses gas, and without some means of relieving her of weight she might have to descend in a hostile country. Major Maitland has proved the practicability of members of an air-ship's crew dropping to the ground if the necessity arises." A descent in a parachute has also been made from an aeroplane by M. Pegoud, the daring French airman, of whom we speak later. A certain Frenchman, M. Bonnet, had constructed a parachute which was intended to be used by the pilot of an aeroplane if on any occasion he got into difficulties. It had been tried in many ways, but, unfortunately for the inventor, he could get no pilot to trust himself to it. Tempting offers were made to pilots of world-wide fame, but either the risk was thought to be too great, or it was believed that no practical good would come of the experiment. At last the inventor approached M. Pegoud, who undertook to make the descent. This was accomplished from a great height with perfect safety. It seems highly probable that in the near future the parachute will form part of the equipment of every aeroplane and air-ship. CHAPTER VII. Some British Inventors of Air-ships The first Englishman to invent an air-ship was Mr. Stanley Spencer, head of the well-known firm of Spencer Brothers, whose works are at Highbury, North London. This firm has long held an honourable place in aeronautics, both in the construction of air-craft and in aerial navigation. Spencer Brothers claim to be the premier balloon manufacturers in the world, and, at the time of writing, eighteen balloons and two dirigibles lie in the works ready for use. In these works there may also be seen the frame of the famous Santos-Dumont air-ship, referred to later in this book. In general appearance the first Spencer air-ship was very similar to the airship flown by Santos-Dumont; that is, there was the cigar-shaped balloon, the small engine, and the screw propellor for driving the craft forward. But there was one very important distinction between the two air-ships. By a most ingenious contrivance the envelope was made so that, in the event of a large and serious escape of gas, the balloon would assume the form of a giant umbrella, and fall to earth after the manner of a parachute. All inventors profit, or should profit, by the experience of others, whether such experience be gained by success or failure. It was found that Santos-Dumont's air-ship lost a considerable amount of gas when driven through the air, and on several occasions the whole craft was in great danger of collapse. To keep the envelope inflated as tightly as possible Mr. Spencer, by a clever contrivance, made it possible to force air into the balloon to replace the escaped gas. The first Spencer air-ship was built for experimental purposes. It was able to lift only one person of light weight, and was thus a great contrast to the modern dirigible which carries a crew of thirty or forty people. Mr. Spencer made several exhibition flights in his little craft at the Crystal Palace, and so successful were they that he determined to construct a much larger craft. The second Spencer air-ship, first launched in 1903, was nearly 100 feet long. There was one very important distinction between this and other air-ships built at that time: the propeller was placed in front of the craft, instead of at the rear, as is the case in most air-ships. Thus the craft was pulled through the air much after the manner of an aeroplane. In the autumn of 1903 great enthusiasm was aroused in London by the announcement that Mr. Spencer proposed to fly from the Crystal Palace round the dome of St. Paul's Cathedral and back to his starting-place. This was a much longer journey than that made by Santos-Dumont when he won the Deutsch prize. Tens of thousands of London's citizens turned out to witness the novel sight of a giant air-ship hovering over the heart of their city, and it was at once seen what enormous possibilities there were in the employment of such craft in time of war. The writer remembers well moving among the dense crowds and hearing everywhere such remarks as these: "What would happen if a few bombs were thrown over the side of the air-ship?" "Will there be air-fleets in future, manned by the soldiers or sailors?" Indeed the uppermost thought in people's minds was not so much the possibility of Mr. Spencer being able to complete his journey successfully--nearly everyone recognized that air-ship construction had now advanced so far that it was only a matter of time for an ideal craft to be built--but that the coming of the air-ship was an affair of grave international importance. The great craft, glistening in the sunlight, sailed majestically from the south, but when it reached the Cathedral it refused to turn round and face the wind. Try how he might, Mr. Spencer could not make any progress. It was a thrilling sight to witness this battle with the elements, right over the heart of the largest city in the world. At times the air-ship seemed to be standing quite still, head to wind. Unfortunately, half a gale had sprung up, and the 24-horse-power engine was quite incapable of conquering so stiff a breeze, and making its way home again. After several gallant attempts to circle round the dome, Mr. Spencer gave up in despair, and let the monster air-ship drift with the wind over the northern suburbs of the city until a favourable landing-place near Barnet was reached, where he descended. The Spencer air-ships are of the non-rigid type. Spencer air-ship A comprises a gas vessel for hydrogen 88 feet long and 24 feet in diameter, with a capacity of 26,000 cubic feet. The framework is of polished ash wood, made in sections so that it can easily be taken to pieces and transported, and the length over all is 56 feet. Two propellers 7 feet 6 inches diameter, made of satin-wood, are employed to drive the craft, which is equipped with a Green engine of from 35 to 40 horse-power. Spencer's air-ship B is a much larger vessel, being 150 feet long and 35 feet in diameter, with a capacity for hydrogen of 100,000 cubic feet. The framework is of steel and aluminium, made in sections, with cars for ten persons, including aeronauts, mechanics, and passengers. It is driven with two petrol aerial engines of from 50 to 60 horse-power. About the time that Mr. Spencer was experimenting with his large air-ship, Dr. Barton, of Beckenham, was forming plans for an even larger craft. This he laid down in the spacious grounds of the Alexandra Park, to the north of London. An enormous shed was erected on the northern slopes of the park, but visitors to the Alexandra Palace, intent on a peep at the monster air-ship under construction, were sorely disappointed, as the utmost secrecy in the building of the craft was maintained. The huge balloon was 43 feet in diameter and 176 feet long, with a gas capacity of 235,000 cubic feet. To maintain the external form of the envelope a smaller balloon, or compensator, was placed inside the larger one. The framework was of bamboo, and the car was attached by about eighty wire-cables. The wooden deck was about 123 feet in length. Two 50-horse-power engines drove four propellers, two of which were at either end. The inventor employed a most ingenious contrivance to preserve the horizontal balance of the air-ship. Fitted, one at each end of the carriage, were two 50-gallon tanks. These tanks were connected with a long pipe, in the centre of which was a hand-pump. When the bow of the air-ship dipped, the man at the pump could transfer some of the water from the fore-tank to the after-tank, and the ship would right itself. The water could similarly be transferred from the after-tank to the fore-tank when the stern of the craft pointed downwards. There were many reports, in the early months of 1905, that the air-ship was going to be brought out from the shed for its trial flights, and the writer, in common with many other residents in the vicinity of the park, made dozens of journeys to the shed in the expectation of seeing the mighty dirigible sail away. But for months we were doomed to disappointment; something always seemed to go wrong at the last minute, and the flight had to be postponed. At last, in 1905, the first ascent took place. It was unsuccessful. The huge balloon, made of tussore silk, cruised about for some time, then drifted away with the breeze, and came to grief in landing. A clever inventor of air-ships, a young Welshman, Mr. E. T. Willows, designed in 1910, an air-ship in which he flew from Cardiff to London in the dark--a distance of 139 miles. In the same craft he crossed the English Channel a little later. Mr. Willows has a large shed in the London aerodrome at Hendon, and he is at present working there on a new air-ship. For some time he has been the only successful private builder of air-ships in Great Britain. The Navy possess a small Willows air-ship. Messrs. Vickers, the famous builders of battleships, are giving attention to the construction of air-ships for the Navy, in their works at Walney Island, Barrow-in-Furness. This firm has erected an enormous shed, 540 feet long, 150 feet broad, and 98 feet high. In this shed two of the largest air-ships can be built side by side. Close at hand is an extensive factory for the production of hydrogen gas. At each end of the roof are towers from which the difficult task of safely removing an air-ship from the shed can be directed. At the time of writing, the redoubtable DORA (Defence of the Realm Act) forbids any but the vaguest references to what is going forward in the way of additions to our air forces. But it may be stated that air-ships are included in the great constructive programme now being carried out. It is not long since the citizens of Glasgow were treated to the spectacle of a full-sized British "Zep" circling round the city prior to her journey south, and so to regions unspecified. And use, too, is being found by the naval arm for that curious hybrid the "Blimp", which may be described as a cross between an aeroplane and an air-ship. CHAPTER VIII. The First Attempts to Steer a Balloon For nearly a century after the invention of the Montgolfier and Charlier balloons there was not much progress made in the science of aeronautics. True, inventors such as Charles Green suggested and carried out new methods of inflating balloons, and scientific observations of great importance were made by balloonists both in Britain and on the Continent. But in the all-important work of steering the huge craft, progress was for many years practically at a standstill. All that the balloonist could do in controlling his balloon was to make it ascend or descend at will; he could not guide its direction of flight. No doubt pioneers of aeronautics early turned their attention to the problem of providing some apparatus, or some method, of steering their craft. One inventor suggested the hoisting of a huge sail at the side of the envelope; but when this was done the balloon simply turned round with the sail to the front. It had no effect on the direction of flight of the balloon. "Would not a rudder be of use?" someone asked. This plan was also tried, but was equally unsuccessful. Perhaps some of us may wonder how it is that a rudder is not as serviceable on a balloon as it is on the stern of a boat. Have you ever found yourself in a boat on a calm day, drifting idly down stream, and going just as fast as the stream goes? Work the rudder how you may, you will not alter the boat's course. But supposing your boat moves faster than the stream, or by some means or other is made to travel slower than the current, then your rudder will act, and you may take what direction you will. It was soon seen that if some method could be adopted whereby the balloon moved through the air faster or slower than the wind, then the aeronaut would be able to steer it. Nowadays a balloon's pace can be accelerated by means of a powerful motor-engine, but the invention of the petrol-engine is very recent. Indeed, the cause of the long delay in the construction of a steerable balloon was that a suitable engine could not be found. A steam-engine, with a boiler of sufficient power to propel a balloon, is so heavy that it would require a balloon of impossible size to lift it. One of the first serious attempts to steer a balloon by means of engine power was that made by M. Giffard in 1852. Giffard's balloon was about 100 feet long and 40 feet in diameter, and resembled in shape an elongated cigar. A 3-horse-power steam-engine, weighing nearly 500 pounds, was provided to work a propeller, but the enormous weight was so great in proportion to the lifting power of the balloon that for a time the aeronaut could not leave the ground. After several experiments the inventor succeeded in ascending, when he obtained a speed against the wind of about 6 miles an hour. A balloon of great historical interest was that invented by Dupuy du Lonie, in the year 1872. Instead of using steam he employed a number of men to propel the craft, and with this air-ship he hoped to communicate with the besieged city of Paris. His greatest speed against a moderate breeze was only about 5 miles an hour, and the endurance of the men did not allow of even this speed being kept up for long at a time. Dupuy foreshadowed the construction of the modern dirigible air-ship by inventing a system of suspension links which connected the car to the envelope; and he also used an internal ballonet similar to those described in Chapter X. In the year 1883 Tissandier invented a steerable balloon which was fitted with an electric motor of 1 1/2 horse-power. This motor drove a propeller, and a speed of about 8 miles an hour was attained. It is interesting to contrast the power obtained from this engine with that of recent Zeppelin air-ships, each of which is fitted with three or four engines, capable of producing over 800 horse-power. The first instance on record of an air-ship being steered back to its starting-point was that of La France. This air-craft was the invention of two French army captains, Reynard and Krebs. By special and much-improved electric motors a speed of about 14 miles an hour was attained. Thus, step by step, progress was made; but notwithstanding the promising results it was quite evident that the engines were far too heavy in proportion to the power they supplied. At length, however, the internal-combustion engine, such as is used in motor-cars, arrived, and it became at last possible to solve the great problem of constructing a really-serviceable, steerable balloon. CHAPTER IX. The Strange Career of Count Zeppelin In Berlin, on March 8, 1917, there passed away a man whose name will be remembered as long as the English language is spoken. For Count Zeppelin belongs to that little band of men who giving birth to a work of genius have also given their names to the christening of it; and so the patronymic will pass down the ages. In the most sinister sense of the expression Count Zeppelin may be said to have left his mark deep down upon the British race. In course of time many old scores are forgiven and forgotten, but the Zeppelin raids on England will survive, if only as a curious failure. Their failure was both material and moral. Anti-aircraft guns and our intrepid airmen brought one after another of these destructive monsters blazing to the ground, and their work of "frightfulness" was taken up by the aeroplane; while more lamentable still was the failure of the Zeppelin as an instrument of terror to the civil population. In the long list of German miscalculations must be included that which pictured the victims of bombardment from the air crying out in terror for peace at any price. Before the war Count Zeppelin was regarded by the British public as rather a picturesque personality. He appeared in the romantic guise of the inventor struggling against difficulties and disasters which would soon have overwhelmed a man of less resolute character. Even old age was included in his handicap, for he was verging on seventy when still arming against a sea of troubles. The ebb and flow of his fortunes were followed with intense interest in this country, and it is not too much to say that the many disasters which overtook his air-ships in their experimental stages were regarded as world-wide calamities. When, finally, the Count stood on the brink of ruin and the Kaiser stepped forward as his saviour, something like a cheer went up from the British public at this theatrical episode. Little did the audience realize what was to be the outcome of the association between these callous and masterful minds. And now for a brief sketch of Count Zeppelin's life-story. He was born in 1838, in a monastery on an island in Lake Constance. His love of adventure took him to America, and when he was about twenty-five years of age he took part in the American Civil War. Here he made his first aerial ascent in a balloon belonging to the Federal army, and in this way made that acquaintance with aeronautics which became the ruling passion of his life. After the war was over he returned to Germany, only to find another war awaiting him--the Austro-Prussian campaign. Later on he took part in the Franco-Prussian War, and in both campaigns he emerged unscathed. But his heart was not in the profession of soldiering. He had the restless mind of the inventor, and when he retired, a general, after twenty years' military service, he was free to give his whole attention to his dreams of aerial navigation. His greatest ambition was to make his country pre-eminent in aerial greatness. Friends to whom he revealed his inmost thoughts laughed at him behind his back, and considered that he was "a little bit wrong in his head". Certainly his ideas of a huge aerial fleet appeared most extravagant, for it must be remembered that the motor-engine had not then arrived, and there appeared no reasonable prospect of its invention. Perseverance, however, was the dominant feature of Count Zeppelin's character; he refused to be beaten. His difficulties were formidable. In the first place, he had to master the whole science of aeronautics, which implies some knowledge of mechanics, meteorology, and electricity. This in itself was no small task for a man of over fifty years of age, for it was not until Count Zeppelin had retired from the army that he began to study these subjects at all deeply. The next step was to construct a large shed for the housing of his air-ship, and also for the purpose of carrying out numerous costly experiments. The Count selected Friedrichshafen, on the shores of Lake Constance, as his head-quarters. He decided to conduct his experiments over the calm waters of the lake, in order to lessen the effects of a fall. The original shed was constructed on pontoons, and it could be turned round as desired, so that the air-ship could be brought out in the lee of any wind from whatsoever quarter it came. It is said that the Count's private fortune of about L25,000 was soon expended in the cost of these works and the necessary experiments. To continue his work he had to appeal for funds to all his friends, and also to all patriotic Germans, from the Kaiser downwards. At length, in 1908, there came a turning-point in his fortunes. The German Government, which had watched the Count's progress with great interest, offered to buy his invention outright if he succeeded in remaining aloft in one of his dirigibles for twenty-four hours. The Count did not quite succeed in his task, but he aroused the great interest of the whole German nation, and a Zeppelin fund was established, under the patronage of the Kaiser, in every town and city in the Fatherland. In about a month the fund amounted to over L300,000. With this sum the veteran inventor was able to extend his works, and produce air-ship after air-ship with remarkable rapidity. When, war broke out it is probable that Germany possessed at least thirteen air-ships which had fulfilled very difficult tests. One had flown 1800 miles in a single journey. Thus the East Coast of England, representing a return journey of less than 600 miles was well within their range of action. CHAPTER X. A Zeppelin Air-ship and its Construction After the Zeppelin fund had brought in a sum of money which probably exceeded all expectations, a company was formed for the construction of dirigibles in the Zeppelin works on Lake Constance, and in 1909 an enormous air-ship was produced. In shape a Zeppelin dirigible resembled a gigantic cigar, pointed at both ends. If placed with one end on the ground in Trafalgar Square, London, its other end would be nearly three times the height of the Nelson Column, which, as you may know, is 166 feet. From the diagram here given, which shows a sectional view of a typical Zeppelin air-ship, we may obtain a clear idea of the main features of the craft. From time to time, during the last dozen years or so, the inventor has added certain details, but the main features as shown in the illustration are common to all air-craft of this type. Zeppelin L1 was 525 feet in length, with a diameter of 50 feet. Some idea of the size may be obtained through the knowledge that she was longer than a modern Dreadnought. The framework was made of specially light metal, aluminium alloy, and wood. This framework, which was stayed with steel wire, maintained the shape and rigidity of her gas-bags; hence vessels of this type are known as RIGID air-ships. Externally the hull was covered with a waterproof fabric. Though, from outside, a rigid air-ship looks to be all in one piece, within it is divided into numerous compartments. In Zeppelin L1 there were eighteen separate compartments, each of which contained a balloon filled with hydrogen gas. The object of providing the vessel with these small balloons, or ballonets, all separate from one another, was to prevent the gas collecting all at one end of the ship as the vessel travelled through the air. Outside the ballonets there was a ring-shaped, double bottom, containing non-inflammable gas, and the whole was enclosed in rubber-coated fabric. The crew and motors were carried in cars slung fore and aft. The ship was propelled by three engines, each of 170 horse-power. One engine was placed in the forward car, and the two others in the after car. To steer her to right or left, she had six vertical planes somewhat resembling box-kites, while eight horizontal planes enabled her to ascend or descend. In Zeppelin L2, which was a later type of craft, there were four motors capable of developing 820 horse-power. These drove four propellers, which gave the craft a speed of about 45 miles an hour. The cars were connected by a gangway built within the framework. On the top of the gas-chambers was a platform of aluminium alloy, carrying a 1-pounder gun, and used also as an observation station. It is thought that L1 was also provided with four machine-guns in her cars. Later types of Zeppelins were fitted with a "wireless" installation of sufficient range to transmit and receive messages up to 350 miles. L1 could rise to the height of a mile in favourable weather, and carry about 7 tons over and above her own weight. Even when on ground the unwieldy craft cause many anxious moments to the officers and mechanics who handle them. Two of the line have broken loose from their anchorage in a storm and have been totally destroyed. Great difficulty is also experienced in getting them in and out of their sheds. Here, indeed, is a contrast with the ease and rapidity with which an aeroplane is removed from its hangar. It was maintained by the inventor that, as the vessel is rigid, and therefore no pressure is required in the gas-chamber to maintain its shape, it will not be readily vulnerable to projectiles. But the Count did not foresee that the very "frightfulness" of his engine of war would engender counter-destructives. In a later chapter an account will be given of the manner in which Zeppelin attacks upon these islands were gradually beaten off by the combined efforts of anti-aircraft guns and aeroplanes. To the latter, and the intrepid pilots and fighters, is due the chief credit for the final overthrow of the Zeppelin as a weapon of offence. Both the British and French airmen in various brilliant sallies succeeded in gradually breaking up and destroying this Armada of the Air; and the Zeppelin was forced back to the one line of work in which it has proved a success, viz., scouting for the German fleet in the few timid sallies it has made from home ports. CHAPTER XI. The Semi-rigid Air-ship Modern air-ships are of three general types: RIGID, SEMI-RIGID, and NON-RIGID. These differ from one another, as the names suggest, in the important feature, the RIGIDITY, NON-RIGIDITY, and PARTIAL RIGIDITY of the gas envelope. Hitherto we have discussed the RIGID type of vessel with which the name of Count Zeppelin is so closely associated. This vessel is, as we have seen, not dependent for its form on the gas-bag, but is maintained in permanent shape by means of an aluminium framework. A serious disadvantage to this type of craft is that it lacks the portability necessary for military purposes. It is true that the vessel can be taken to pieces, but not quickly. The NON-RIGID type, on the other hand, can be quickly deflated, and the parts of the car and engine can be readily transported to the nearest balloon station when occasion requires. In the SEMI-RIGID type of air-ship the vessel is dependent for its form partly on its framework and partly on the form of the gas envelope. The under side of the balloon consists of a flat rigid framework, to which the planes are attached, and from which the car, the engine, and propeller are suspended. As the rigid type of dirigible is chiefly advocated in Germany, so the semi-rigid craft is most popular in France. The famous Lebaudy air-ships are good types of semi-rigid vessels. These were designed for the firm of Lebaudy Freres by the well-known French engineer M. Henri Julliot. In November, 1902, M. Julliot and M. Surcouf completed an air-ship for M. Lebaudy which attained a speed of nearly 25 miles an hour. The craft, which was named Lebaudy I, made many successful voyages, and in 1905 M. Lebaudy offered a second vessel, Lebaudy II, to the French Minister of War, who accepted it for the French nation, and afterwards decided to order another dirigible, La Patrie, of the same type. Disaster, however, followed these air-ships. Lebaudy I was torn from its anchorage during a heavy gale in 1906, and was completely wrecked. La Patrie, after travelling in 1907 from Paris to Verdun, in seven hours, was, a few days later, caught in a gale, and the pilot was forced to descend. The wind, however, was so strong that 200 soldiers were unable to hold down the unwieldy craft, and it was torn from their hands. It sailed away in a north-westerly direction over the Channel into England, and ultimately disappeared into the North Sea, where it was subsequently discovered some days after the accident. Notwithstanding these disasters the French military authorities ordered another craft of the same type, which was afterwards named the Republique. This vessel made a magnificent flight of six and a half hours in 1908, and it was considered to have quite exceptional features, which eclipsed the previous efforts of Messrs. Julliot and Lebaudy. Unfortunately, however, this vessel was wrecked in a very terrible manner. While out cruising with a crew of four officers one of the propeller blades was suddenly fractured, and, flying off with immense force, it entered the balloon, which it ripped to pieces. The majestic craft crumpled up and crashed to the ground, killing its crew in its fall. In the illustration facing p. 17, of a Lebaudy air-ship, we have a good type of the semi-rigid craft. In shape it somewhat resembles an enormous porpoise, with a sharply-pointed nose. The whole vessel is not as symmetrical as a Zeppelin dirigible, but its inventors claim that the sharp prow facilitates the steady displacement of the air during flight. The stern is rounded so as to provide sufficient support for the rear planes. Two propellers are employed, and are fixed outside the car, one on each side, and almost in the centre of the vessel. This is a some what unusual arrangement. Some inventors, such as Mr. Spencer, place the propellers at the prow, so that the air-ship is DRAWN along; others prefer the propeller at the stern, whereby the craft is PUSHED along; but M. Julliot chose the central position, because there the disturbance of the air is smallest. The body of the balloon is not quite round, for the lower part is flattened and rests on a rigid frame from which the car is suspended. The balloon is divided into three compartments, so that the heavier air does not move to one part of the balloon when it is tilted. In the picture there is shown the petrol storage-tank, which is suspended immediately under the rear horizontal plane, where it is out of danger of ignition from the hot engine placed in the car. CHAPTER XII. A Non-rigid Balloon Hitherto we have described the rigid and semi-rigid types of air-ships. We have seen that the former maintains its shape without assistance from the gas which inflates its envelope and supplies the lifting power, while the latter, as its name implies, is dependent for its form partly on the flat rigid framework to which the car is attached, and partly on the gas balloon. We have now to turn our attention to that type of craft known as a NON-RIGID BALLOON. This vessel relies for its form ENTIRELY upon the pressure of the gas, which keeps the envelope distended with sufficient tautness to enable it to be driven through the air at a considerable speed. It will at once be seen that the safety of a vessel of this type depends on the maintenance of the gas pressure, and that it is liable to be quickly put out of action if the envelope becomes torn. Such an occurrence is quite possible in war. A well-directed shell which pierced the balloon would undoubtedly be disastrous to air-ship and crew. For this reason the non-rigid balloon does not appear to have much future value as a fighting ship. But, as great speed can be obtained from it, it seems especially suited for short overland voyages, either for sporting or commercial purposes. One of its greatest advantages is that it can be easily deflated, and can be packed away into a very small compass. A good type of the non-rigid air-ship is that built by Major Von Parseval, which is named after its inventor. The Parseval has been described as "a marvel of modern aeronautical construction", and also as "one of the most perfect expressions of modern aeronautics, not only on account of its design, but owing to its striking efficiency." The balloon has the elongated form, rounded or pointed at one end, or both ends, which is common to most air-ships. The envelope is composed of a rubber-texture fabric, and externally it is painted yellow, so that the chemical properties of the sun's rays may not injure the rubber. There are two smaller interior balloons, or COMPENSATORS, into which can be pumped air by means of a mechanically-driven fan or ventilator, to make up for contraction of the gas when descending or meeting a cooler atmosphere. The compensators occupy about one-quarter of the whole volume. To secure the necessary inclination of the balloon while in flight, air can be transferred from one of the compensators, say at the fore end of the ship, into the ballonet in the aft part. Suppose it is desired to incline the bow of the craft upward, then the ventilating fan would DEFLATE the fore ballonet and INFLATE the aft one, so that the latter, becoming heavier, would lower the stern and raise the bow of the vessel. Along each side of the envelope are seen strips to which the car suspension-cords are attached. To prevent these cords being jerked asunder, by the rolling or pitching of the vessel, horizontal fins, each 172 square feet in area, are provided at each side of the rear end of the balloon. In the past several serious accidents have been caused by the violent pitching of the balloon when caught in a gale, and so severe have been the stresses on the suspension cords that great damage has been done to the envelope, and the aeronauts have been fortunate if they have been able to make a safe descent. The propeller and engine are carried by the car, which is slung well below the balloon, and by an ingenious contrivance the car always remains in a horizontal position, however much the balloon may be inclined. It is no uncommon occurrence for the balloon to make a considerable angle with the car beneath. The propeller is quite a work of art. It has a diameter of about 14 feet, and consists of a frame of hollow steel tubes covered with fabric. It is so arranged that when out of action its blades fall lengthwise upon the frame supporting it, but when it is set to work the blades at once open out. The engine weighs 770 pounds, and has six cylinders, which develop 100 horse-power at 1200 revolutions a minute. The vessel may be steered either to the right or the left by means of a large vertical helm, some 80 square feet in area, which is hinged at the rear end to a fixed vertical plane of 200 square feet area. An upward or downward inclination is, as we have seen, effected by the ballonets, but in cases of emergency these compensators cannot be deflated or inflated sufficiently rapidly, and a large movable weight is employed for altering the balance of the vessel. In this country the authorities have hitherto favoured the non-rigid air-ship for military and naval use. The Astra-Torres belongs to this type of vessel, which can be rapidly deflated and transported, and so, too, the air-ship built by Mr. Willows. CHAPTER XIII. The Zeppelin and Gotha Raids In the House of Commons recently Mr. Bonar Law announced that since the commencement of the war 14,250 lives had been lost as the result of enemy action by submarines and air-craft. A large percentage of these figures represents women, children, and defenceless citizens. One had become almost hardened to the German method of making war on the civil population--that system of striving to act upon civilian "nerves" by calculated brutality which is summed up in the word "frightfulness". But the publication of these figures awoke some of the old horror of German warfare. The sum total of lives lost brought home to the people at home the fact that bombardment from air and sea, while it had failed to shake their MORAL, had taken a large toll of human life. At first the Zeppelin raids were not taken very seriously in this country. People rushed out of their houses to see the unwonted spectacle of an air-ship dealing death and destruction from the clouds. But soon the novelty began to wear off, and as the raids became more frequent and the casualty lists grew larger, people began to murmur against the policy of taking these attacks "lying down". It was felt that "darkness and composure" formed but a feeble and ignoble weapon of defence. The people spoke with no uncertain voice, and it began to dawn upon the authorities that the system of regarding London and the south-east coast as part of "the front" was no excuse for not taking protective measures. It was the raid into the Midlands on the night of 31st January, 1916, that finally shelved the old policy of do nothing. Further justification, if any were needed, for active measures was supplied by a still more audacious raid upon the east coast of Scotland, upon which occasion Zeppelins soared over England--at their will. Then the authorities woke up, and an extensive scheme of anti-aircraft guns and squadrons of aeroplanes was devised. About March of the year 1916 the Germans began to break the monotony of the Zeppelin raids by using sea-planes as variants. So there was plenty of work for our new defensive air force. Indeed, people began to ask themselves why we should not hit back by making raids into Germany. The subject was well aired in the public press, and distinguished advocates came forward for and against the policy of reprisals. At a considerably later date reprisals carried the day, and, as we write, air raids by the British into Germany are of frequent occurrence. In March, 1916, the fruits of the new policy began to appear, and people found them very refreshing. A fleet of Zeppelins found, on approaching the mouth of the Thames, a very warm reception. Powerful searchlights, and shells from new anti-aircraft guns, played all round them. At length a shot got home. One of the Zeppelins, "winged" by a shell, began a wobbly retreat which ended in the waters of the estuary. The navy finished the business. The wrecked air-ship was quickly surrounded by a little fleet of destroyers and patrol-boats, and the crew were brought ashore, prisoners. That same night yet another Zeppelin was hit and damaged in another part of the country. Raids followed in such quick succession as to be almost of nightly occurrence during the favouring moonless nights. Later, the conditions were reversed, and the attacks by aeroplane were all made in bright moonlight. But ever the defence became more strenuous. Then aeroplanes began to play the role of "hornets", as Mr. Winston Churchill, speaking rather too previously, designated them. Lieutenant Brandon, R.F.C., succeeded in dropping several aerial bombs on a Zeppelin during the raid on March 31, but it was not until six months later that an airman succeeded in bringing down a Zeppelin on British soil. The credit of repeating Lieutenant Warneford's great feat belongs to Lieutenant W. R. Robinson, and the fight was witnessed by a large gathering. It occurred in the very formidable air raid on the night of September 2. Breathlessly the spectators watched the Zeppelin harried by searchlight and shell-fire. Suddenly it disappeared behind a veil of smoke which it had thrown out to baffle its pursuers. Then it appeared again, and a loud shout went up from the watching thousands. It was silhouetted against the night clouds in a faint line of fire. The hue deepened, the glow spread all round, and the doomed airship began its crash to earth in a smother of flame. The witnesses to this amazing spectacle naturally supposed that a shell had struck the Zeppelin. Its tiny assailant that had dealt the death-blow had been quite invisible during the fight. Only on the following morning did the public learn of Lieutenant Robinson's feat. It appeared that he had been in the air a couple of hours, engaged in other conflicts with his monster foes. Besides the V.C. the plucky airman won considerable money prizes from citizens for destroying the first Zeppelin on British soil. The Zeppelin raids continued at varying intervals for the remainder of the year. As the power of the defence increased the air-ships were forced to greater altitudes, with a corresponding decrease in the accuracy with which they could aim bombs on specified objects. But, however futile the raids, and however widely they missed their mark, there was no falling off in the outrageous claims made in the German communiques. Bombs dropped in fields, waste lands, and even the sea, masqueraded in the reports as missiles which had sunk ships in harbour, destroyed docks, and started fires in important military areas. So persistent were these exaggerations that it became evident that the Zeppelin raids were intended quite as much for moral effect at home as for material damage abroad. The heartening effect of the raids upon the German populace is evidenced by the mental attitude of men made prisoners on any of the fronts. Only with the utmost difficulty were their captors able to persuade them that London and other large towns were not in ruins; that shipbuilding was not at a standstill; and that the British people was not ready at any moment to purchase indemnity from the raids by concluding a German peace. When one method of terrorism fails try another, was evidently the German motto. After the Zeppelin the Gotha, and after that the submarine. The next year--1917--brought in a very welcome change in the situation. One Zeppelin after another met with its just deserts, the British navy in particular scoring heavily against them. Nor must the skill and enterprise of our French allies be forgotten. In March, 1917, they shot down a Zeppelin at Compiegne, and seven months later dealt the blow which finally rid these islands of the Zeppelin menace. For nearly a year London, owing to its greatly increased defences, had been free from attack. Then, on the night of October 19, Germany made a colossal effort to make good their boast of laying London in ruins. A fleet of eleven Zeppelins came over, five of which found the city. One, drifting low and silently, was responsible for most of the casualties, which totalled 34 killed and 56 injured. The fleet got away from these shores without mishap. Then, at long last, came retribution. Flying very high, they seem to have encountered an aerial storm which drove them helplessly over French territory. Our allies were swift to seize this golden opportunity. Their airmen and anti-aircraft guns shot down no less than four of the Zeppelins in broad daylight, one of which was captured whole. Of the remainder, one at least drifted over the Mediterranean, and was not heard of again. That was the last of the Zeppelin, so far as the civilian population was concerned. But, for nearly a year, the work of killing citizens had been undertaken by the big bomb-dropping Gotha aeroplanes. The work of the Gotha belongs rightly to the second part of this book, which deals with aeroplanes and airmen; but it would be convenient to dispose here of the part played by the Gotha in the air raids upon this country. The reconnaissance took place on Tuesday, November 28, 1916, when in a slight haze a German aeroplane suddenly appeared over London, dropped six bombs, and flew off. The Gotha was intercepted off Dunkirk by the French, and brought down. Pilot and observer-two naval lieutenants-were found to have a large-scale map of London in their possession. The new era of raids had commenced. Very soon it became evident that the new squadron of Gothas were much more destructive than the former fleets of unwieldy Zeppelins. These great Gothas were each capable of dropping nearly a ton of bombs. And their heavy armament and swift flight rendered them far less vulnerable than the air-ship. From March 1 to October 31, 1917, no less than twenty-two raids took place, chiefly on London and towns on the south-east coast. The casualties amounted to 484 killed and 410 wounded. The two worst raids occurred June 13 on East London, and September 3 on the Sheerness and Chatham area. A squadron of fifteen aeroplanes carried out the raid, on June 13, and although they were only over the city for a period of fifteen minutes the casualty list was exceedingly heavy--104 killed and 432 wounded. Many children were among the killed and injured as the result of a bomb which fell upon a Council school. The raid was carried out in daylight, and the bombs began to drop before any warning could be given. Later, an effective and comprehensive system of warnings was devised, and when people had acquired the habit of taking shelter, instead of rushing out into the street to see the aerial combats, the casualties began to diminish. It is worthy of record that the possible danger to schools had been anticipated, and for some weeks previously the children had taken part in "Air Raid Drill". When the raid came, the children behaved in the most exemplary fashion. They went through the manoeuvres as though it was merely a rehearsal, and their bearing as well as the coolness of the teachers obviated all danger from panic. In this raid the enemy first made use of aerial torpedoes. Large loss of life, due to a building being struck, was also the feature of the moonlight raid on September 4. On this occasion enemy airmen found a mark on the Royal Naval barracks at Sheerness. The barracks were fitted with hammocks for sleeping, and no less than 108 bluejackets lost their lives, the number of wounded amounting to 92. Although the raid lasted nearly an hour and powerful searchlights were brought into play, neither guns nor our airmen succeeded in causing any loss to the raiders. Bombs were dropped at a number of other places, including Margate and Southend, but without result. No less than six raids took place on London before the end of the month, but the greatest number of killed in any one of the raids was eleven, while on September 28 the raiders were driven off before they could claim any victims. The establishment of a close barrage of aerial guns did much to discourage the raiders, and gradually London, from being the most vulnerable spot in the British Isles, began to enjoy comparative immunity from attack. Paris, too, during the Great War has had to suffer bombardment from the air, but not nearly to the same extent as London. The comparative immunity of Paris from air raids is due partly to the prompt measures which were taken to defend the capital. The French did not wait, as did the British, until the populace was goaded to the last point of exasperation, but quickly instituted the barrage system, in which we afterwards followed their lead. Moreover, the French were much more prompt in adopting retaliatory tactics. They hit back without having to wade through long moral and philosophical disquisitions upon the ethics of "reprisals". On the other hand, it must be remembered that Paris, from the aerial standpoint, is a much more difficult objective than London. The enemy airman has to cross the French lines, which, like his own, stretch for miles in the rear. Practically he is in hostile country all the time, and he has to get back across the same dangerous air zones. It is a far easier task to dodge a few sea-planes over the wide seas en route to London. And on reaching the coast the airman has to evade or fight scattered local defences, instead of penetrating the close barriers which confront him all the way to Paris. Since the first Zeppelin attack on Paris on March 21, 1915, when two of the air-ships reached the suburbs, killing 23 persons and injuring 30, there have been many raids and attempted raids, but mostly by single machines. The first air raid in force upon the French capital took place on January 31, 1918, when a squadron of Gothas crossed the lines north of Compiegne. Two hospitals were hit, and the casualties from the raid amounted to 20 killed and 50 wounded. After the Italian set-back in the winter of 1917, the Venetian plain lay open to aerial bombardment by the Germans, who had given substantial military aid to their Austrian allies. This was an opportunity not to be lost by Germany, and Venice and other towns of the plain were subject to systematic bombardment. At the time of writing, Germany is beginning to suffer some of the annoyances she is so ready to inflict upon others. The recently constituted Air Ministry have just published figures relating to the air raids into Germany from December 1, 1917, to February 19, 1918 inclusive. During these eleven weeks no fewer than thirty-five raids have taken place upon a variety of towns, railways, works, and barracks. In the list figure such important towns as Mannheim (pop. 20,000) and Metz (pop. 100,000). The average weight of bombs dropped at each raid works out about 1000 lbs. This welcome official report is but one of many signs which point the way to the growing supremacy of the Allies in the air. PART II. AEROPLANES AND AIRMEN CHAPTER XIV. Early Attempts in Aviation The desire to fly is no new growth in humanity. For countless years men have longed to emulate the birds--"To soar upward and glide, free as a bird, over smiling fields, leafy woods, and mirror-like lakes," as a great pioneer of aviation said. Great scholars and thinkers of old, such as Horace, Homer, Pindar, Tasso, and all the glorious line, dreamt of flight, but it has been left for the present century to see those dreams fulfilled. Early writers of the fourth century saw the possibility of aerial navigation, but those who tried to put their theories in practice were beset by so many difficulties that they rarely succeeded in leaving the ground. Most of the early pioneers of aviation believed that if a man wanted to fly he must provide himself with a pair of wings similar to those of a large bird. The story goes that a certain abbot told King James IV of Scotland that he would fly from Stirling Castle to Paris. He made for himself powerful wings of eagles' feathers, which he fixed to his body and launched himself into the air. As might be expected, he fell and broke his legs. But although the muscles of man are of insufficient strength to bear him in the air, it has been found possible, by using a motor engine, to give to man the power of flight which his natural weakness denied him. Scientists estimate that to raise a man of about 12 stone in the air and enable him to fly there would be required an immense pair of wings over 20 feet in span. In comparison with the weight of a man a bird's weight is remarkably small--the largest bird does not weigh much more than 20 pounds--but its wing muscles are infinitely stronger in proportion than the shoulder and arm muscles of a man. As we shall see in a succeeding chapter, the "wing" theory was persevered with for many years some two or three centuries ago, and later on it was of much use in providing data for the gradual development of the modern aeroplane. CHAPTER XV. A Pioneer in Aviation Hitherto we have traced the gradual development of the balloon right from the early days of aeronautics, when the brothers Montgolfier constructed their hot-air balloon, down to the most modern dirigible. It is now our purpose, in this and subsequent chapters, to follow the course of the pioneers of aviation. It must not be supposed that the invention of the steerable balloon was greatly in advance of that of the heavier-than-air machine. Indeed, developments in both the dirigible airship and the aeroplane have taken place side by side. In some cases men like Santos Dumont have given earnest attention to both forms of air-craft, and produced practical results with both. Thus, after the famous Brazilian aeronaut had won the Deutsch prize for a flight in an air-ship round the Eiffel tower, he immediately set to work to construct an aeroplane which he subsequently piloted at Bagatelle and was awarded the first "Deutsch prize" for aviation. It is generally agreed that the undoubted inventor of the aeroplane, practically in the form in which it now appears, was an English engineer, Sir George Cayley. Just over a hundred years ago this clever Englishman worked out complete plans for an aeroplane, which in many vital respects embodied the principal parts of the monoplane as it exists to-day. There were wings which were inclined so that they formed a lifting plane; moreover, the wings were curved, or "cambered", similar to the wing of a bird, and, as we shall see in a later chapter, this curve is one of the salient features of the plane of a modern heavier-than-air machine. Sir George also advocated the screw propeller worked by some form of "explosion" motor, which at that time had not arrived. Indeed, if there had been a motor available it is quite possible that England would have led the way in aviation. But, unfortunately, owing to the absence of a powerful motor engine, Sir George's ideas could not be practically carried out till nearly a century later, and then Englishmen were forestalled by the Wright brothers, of America, as well as by several French inventors. The distinguished French writer, Alphonse Berget, in his book, The Conquest of the Air, pays a striking tribute to our English inventor, and this, coming from a gentleman who is writing from a French point of view, makes the praise of great value. In alluding to Sir George, M. Berget says: "The inventor, the incontestable forerunner of aviation, was an Englishman, Sir George Cayley, and it was in 1809 that he described his project in detail in Nicholson's Journal.... His idea embodied 'everything'--the wings forming an oblique sail, the empennage, the spindle forms to diminish resistance, the screw-propeller, the 'explosion' motor,... he even described a means of securing automatic stability. Is not all that marvellous, and does it not constitute a complete specification for everything in aviation? "Thus it is necessary to inscribe the name of Sir George Cayley in letters of gold, in the first page of the aeroplane's history. Besides, the learned Englishman did not confine himself to 'drawing-paper': he built the first apparatus (without a motor) which gave him results highly promising. Then he built a second machine, this time with a motor, but unfortunately during the trials it was smashed to pieces." But were these ideas of any practical value? How is it that he did not succeed in flying, if he had most of the component parts of an aeroplane as we know it to-day? The answer to the second question is that Sir George did not fly, simply because there was no light petrol motor in existence; the crude motors in use were far too heavy, in proportion to the power developed, for service in a flying machine. It was recognized, not only by Sir George, but by many other English engineers in the first half of the nineteenth century, that as soon as a sufficiently powerful and light engine did appear, then half the battle of the conquest of the air would be won. But his prophetic voice was of the utmost assistance to such inventors as Santos Dumont, the Wright brothers, M. Bleriot, and others now world-famed. It is quite safe to assume that they gave serious attention to the views held by Sir George, which were given to the world at large in a number of highly-interesting lectures and magazine articles. "Ideas" are the very foundation-stones of invention--if we may be allowed the figure of speech--and Englishmen are proud, and rightly proud, to number within their ranks the original inventor of the heavier-than-air machine. CHAPTER XVI. The "Human Birds" For many years after the publication of Sir George Cayley's articles and lectures on aviation very little was done in the way of aerial experiments. True, about midway through the nineteenth century two clever engineers, Henson and Stringfellow, built a model aeroplane after the design outlined by Sir George; but though their model was not of much practical value, a little more valuable experience was accumulated which would be of service when the time should come; in other words, when the motor engine should arrive. This model can be seen at the Victoria and Albert Museum, at South Kensington. A few years later Stringfellow designed a tiny steam-engine, which he fitted to an equally tiny monoplane, and it is said that by its aid he was able to obtain a very short flight through the air. As some recognition of his enterprise the Aeronautical Society, which was founded in 1866, awarded him a prize of L100 for his engine. The idea of producing a practical form of flying machine was never abandoned entirely. Here and there experiments continued to be carried out, and certain valuable conclusions were arrived at. Many advanced thinkers and writers of half a century ago set forth their opinions on the possibilities of human flight. Some of them, like Emerson, not only believed that flight would come, but also stated why it had not arrived. Thus Emerson, when writing on the subject of air navigation about fifty years ago, remarked: "We think the population is not yet quite fit for them, and therefore there will be none. Our friend suggests so many inconveniences from piracy out of the high air to orchards and lone houses, and also to high fliers, and the total inadequacy of the present system of defence, that we have not the heart to break the sleep of the great public by the repetition of these details. When children come into the library we put the inkstand and the watch on the high shelf until they be a little older." About the year 1870 a young German engineer, named Otto Lilienthal, began some experiments with a motorless glider, which in course of time were to make him world-famed. For nearly twenty years Lilienthal carried on his aerial research work in secrecy, and it was not until about the year 1890 that his experimental work was sufficiently advanced for him to give demonstrations in public. The young German was a firm believer in what was known as the "soaring-plane" theory of flight. From the picture here given we can get some idea of his curious machine. It consisted of large wings, formed of thin osiers, over which was stretched light fabric. At the back were two horizontal rudders shaped somewhat like the long forked tail of a swallow, and over these was a large steering rudder. The wings were arranged around the glider's body. The whole apparatus weighed about 40 pounds. Lilienthal's flights, or glides, were made from the top of a specially-constructed large mound, and in some cases from the summit of a low tower. The "birdman" would stand on the top of the mound, full to the wind, and run quickly forward with outstretched wings. When he thought he had gained sufficient momentum he jumped into the air, and the wings of the glider bore him through the air to the base of the mound. To preserve the balance of his machine--always a most difficult feat--he swung his legs and hips to one side or the other, as occasion required, and, after hundreds of glides had been made, he became so skilful in maintaining the equilibrium of his machine that he was able to cover a distance, downhill, of 300 yards. Later on, Lilienthal abandoned the glider, or elementary form of monoplane, and adopted a system of superposed planes, corresponding to the modern biplane. The promising career of this clever German was brought to an untimely end in 1896, when, in attempting to glide from a height of about 80 yards, his apparatus made a sudden downward swoop, and he broke his neck. Now that Lillenthal's experiments had proved conclusively the efficiency of wings, or planes, as carrying surfaces, other engineers followed in his footsteps, and tried to improve on his good work. The first "birdman" to use a glider in this country was Mr. Percy Pilcher who carried out his experiments at Cardross in Scotland. His glides were at first made with a form of apparatus very similar to that employed by Lilienthal, and in time he came to use much larger machines. So cumbersome, however, was his apparatus--it weighed nearly 4 stones--that with such a great weight upon his shoulders he could not run forward quickly enough to gain sufficient momentum to "carry off" from the hillside. To assist him in launching the apparatus the machine was towed by horses, and when sufficient impetus had been gained the tow-rope was cast off. Three years after Lilienthal's death Pilcher met with a similar accident. While making a flight his glider was overturned, and the unfortunate "birdman" was dashed to death. In America there were at this time two or three "human birds", one of the most famous being M. Octave Chanute. During the years 1895-7 Chanute made many flights in various types of gliding machines, some of which had as many as half a dozen planes arranged one above another. His best results, however, were obtained by the two-plane machine, resembling to a remarkable extent the modern biplane. CHAPTER XVII. The Aeroplane and the Bird We have seen that the inventors of flying machines in the early days of aviation modelled their various craft somewhat in the form of a bird, and that many of them believed that if the conquest of the air was to be achieved man must copy nature and provide himself with wings. Let us closely examine a modern monoplane and discover in what way it resembles the body of a bird in build. First, there is the long and comparatively narrow body, or FUSELAGE, at the end of which is the rudder, corresponding to the bird's tail. The chassis, or under carriage, consisting of wheels, skids, &c., may well be compared with the legs of a bird, and the planes are very similar in construction to the bird's wings. But here the resemblance ends: the aeroplane does not fly, nor will it ever fly, as a bird flies. If we carefully inspect the wing of a bird--say a large bird, such as the crow--we shall find it curved or arched from front to back. This curve, however, is somewhat irregular. At the front edge of the wing it is sharpest, and there is a gradual dip or slope backwards and downwards. There is a special reason for this peculiar structure, as we shall see in a later chapter. Now it is quite evident that the inventors of aeroplanes have modelled the planes of their craft on the bird's wing. Strictly speaking, the word "plane" is a misnomer when applied to the supporting structure of an aeroplane. Euclid defines a plane, or a plane surface, as one in which, any two points being taken, the straight line between them lies wholly in that surface. But the plane of a flying machine is curved, or CAMBERED, and if one point were taken on the front of the so-called plane, and another on the back, a straight line joining these two points could not possibly lie wholly on the surface. All planes are not cambered to the same extent: some have a very small curvature; in others the curve is greatly pronounced. Planes of the former type are generally fitted to racing aeroplanes, because they offer less resistance to the air than do deeply-cambered planes. Indeed, it is in the degree of camber that the various types of flying machine show their chief diversity, just as the work of certain shipmasters is known by the particular lines of the bow and stern of the vessels which are built in their yards. Birds fly by a flapping movement of their wings, or by soaring. We are quite familiar with both these actions: at one time the bird propels itself by means of powerful muscles attached to its wings by means of which the wings are flapped up and down; at another time the bird, with wings nicely adjusted so as to take advantage of all the peculiarities of the air currents, keeps them almost stationary, and soars or glides through the air. The method of soaring alone has long since been proved to be impracticable as a means of carrying a machine through the air, unless, of course, one describes the natural glide of an aeroplane from a great height down to earth as soaring. But the flapping motion was not proved a failure until numerous experiments by early aviators had been tried. Probably the most successful attempt at propulsion by this method was that of a French locksmith named Besnier. Over two hundred years ago he made for himself a pair of light wooden paddles, with blades at either end, somewhat similar in shape to the double paddle of a canoe. These he placed over his shoulders, his feet being attached by ropes to the hindmost paddles. Jumping off from some high place in the face of a stiff breeze, he violently worked his arms and legs, so that the paddles beat the air and gave him support. It is said that Besnier became so expert in the management of his simple apparatus that he was able to raise himself from the ground, and skim lightly over fields and rivers for a considerable distance. Now it has been shown that the enormous extent of wing required to support a man of average weight would be much too large to be flapped by man's arm muscles. But in this, as with everything else, we have succeeded in harnessing the forces of nature into our service as tools and machinery. And is not this, after all, one of the chief, distinctions between man and the lower orders of creation? The latter fulfil most of their bodily requirements by muscular effort. If a horse wants to get from one place to another it walks; man can go on wheels. None of the lower animals makes a single tool to assist it in the various means of sustaining life; but man puts on his "thinking-cap", and invents useful machines and tools to enable him to assist or dispense with muscular movement. Thus we find that in aviation man has designed the propeller, which, by its rapid revolutions derived from the motive power of the aerial engine, cuts a spiral pathway through the air and drives the light craft rapidly forward. The chief use of the planes is for support to the machine, and the chief duty of the pilot is to balance and steer the craft by the manipulation of the rudder, elevation and warping controls. CHAPTER XVIII. A Great British Inventor of Aeroplanes Though, as we have seen, most of the early attempts at aerial navigation were made by foreign engineers, yet we are proud to number among the ranks of the early inventors of heavier-than-air machines Sir Hiram Maxim, who, though an American by birth, has spent most of his life in Britain and may therefore be called a British inventor. Perhaps to most of us this inventor's name is known more in connection with the famous "Maxim" gun, which he designed, and which was named after him. But as early as 1894, when the construction of aeroplanes was in a very backward state, Sir Hiram succeeded in making an interesting and ingenious aeroplane, which he proposed to drive by a particularly light steam-engine. Sir Hiram's first machine, which was made in 1890, was designed to be guided by a double set of rails, one set arranged below and the other above its running wheels. The intention was to make the machine raise itself just off the ground rails, but yet be prevented from soaring by the set of guard rails above the wheels, which acted as a check on it. The motive force was given by a very powerful steam-engine of over 300 horse-power, and this drove two enormous propellers, some 17 feet in length. The total weight of the machine was 8000 pounds, but even with this enormous weight the engine was capable of raising the machine from the ground. For three or four years Sir Hiram made numerous experiments with his aeroplane, but in 1894 it broke through the upper guard rail and turned itself over among the surrounding trees, wrecking itself badly. But though the Maxim aeroplane did not yield very practical results, it proved that if a lighter but more powerful engine could be made, the chief difficulty iii the way of aerial flight would be removed. This was soon forthcoming in the invention of the petrol motor. In a lecture to the Scottish Aeronautical Society, delivered in Glasgow in November, 1913, Sir Hiram claimed to be the inventor of the first machine which actually rose from the earth. Before the distinguished inventor spoke of his own work in aviation he recalled experiments made by his father in 1856-7, when Sir Hiram was sixteen years of age. The flying machine designed by the elder Maxim consisted of a small platform, which it was proposed to lift directly into the air by the action of two screw-propellers revolving in reverse directions. For a motor the inventor intended to employ some kind of explosive material, gunpowder preferred, but the lecturer distinctly remembered that his father said that if an apparatus could be successfully navigated through the air it would be of such inevitable value as a military engine that no matter how much it might cost to run it would be used by Governments. Of his own claim as an inventor of air-craft it would be well to quote Sir Hiram's actual words, as given by the Glasgow Herald, which contained a full report of the lecture. "Some forty years ago, when I commenced to think of the subject, my first idea was to lift my machine by vertical propellers, and I actually commenced drawings and made calculations for a machine on that plan, using an oil motor, or something like a Brayton engine, for motive power. However, I was completely unable to work out any system which would not be too heavy to lift itself directly into the air, and it was only when I commenced to study the aeroplane system that it became apparent to me that it would be possible to make a machine light enough and powerful enough to raise itself without the agency of a balloon. From the first I was convinced that it would be quite out of the question to employ a balloon in any form. At that time the light high-speed petrol motor had no existence. The only power available being steam-engines, I made all my calculations with a view of using steam as the motive power. While I was studying the question of the possibility of making a flying machine that would actually fly, I became convinced that there was but one system to work on, and that was the aeroplane system. I made many calculations, and found that an aeroplane machine driven by a steam-engine ought to lift itself into the air." Sir Hiram then went on to say that it was the work of making an automatic gun which was the direct cause of his experiments with flying machines. To continue the report: "One day I was approached by three gentlemen who were interested in the gun, and they asked me if it would be possible for me to build a flying machine, how long it would take, and how much it would cost. My reply was that it would take five years and would cost L50,000. The first three years would be devoted to developing a light internal-combustion engine, and the remaining two years to making a flying machine. "Later on a considerable sum of money was placed at my disposal, and the experiments commenced, but unfortunately the gun business called for my attention abroad, and during the first two years of the experimental work I was out of England eighteen months. "Although I had thought much of the internal-combustion engine it seemed to me that it would take too long to develop one and that it would be a hopeless task in my absence from England; so I decided that in my first experiments at least I would use a steam-engine. I therefore designed and made a steam-engine and boiler of which Mr. Charles Parsons has since said that, next to the Maxim gun, it developed more energy for its weight than any other heat engine ever made. That was true at the time, but is very wide of the mark now." Speaking of motors, the veteran lecturer remarked: "Perhaps there was no problem in the world on which mathematicians had differed so widely as on the problem of flight. Twenty years ago experimenters said: 'Give us a motor that will develop 1 horse-power with the weight of a barnyard fowl, and we will very soon fly.' At the present moment they had motors which would develop over 2 horse-power and did not weigh more than a 12-pound barnyard fowl. These engines had been developed--I might say created--by the builders of motor cars. Extreme lightness had been gradually obtained by those making racing cars, and that had been intensified by aviators. In many cases a speed of 80 or 100 miles per hour had been attained, and machines had remained in the air for hours and had flown long distances. In some cases nearly a ton had been carried for a short distance." Such words as these, coming from the lips of a great inventor, give us a deep insight into the working of the inventor's mind, and, incidentally, show us some of the difficulties which beset all pioneers in their tasks. The science of aviation is, indeed, greatly indebted to these early inventors, not the least of whom is the gallant Sir Hiram Maxim. CHAPTER XIX. The Wright Brothers and their Secret Experiments In the beginning of the twentieth century many of the leading European newspapers contained brief reports of aerial experiments which were being carried out at Dayton, in the State of Ohio, America. So wonderful were the results of these experiments, and so mysterious were the movements of the two brothers--Orville and Wilbur Wright--who conducted them, that many Europeans would not believe the reports. No inventors have gone about their work more carefully, methodically, and secretly than did these two Americans, who, hidden from prying eyes, "far from the madding crowd", obtained results which brought them undying fame in the world of aviation. For years they worked at their self-imposed task of constructing a flying machine which would really soar among the clouds. They had read brief accounts of the experiments carried out by Otto Lilienthal, and in many ways the ground had been well paved for them. It was their great ambition to become real "human birds"; "birds" that would not only glide along down the hillside, but would fly free and unfettered, choosing their aerial paths of travel and their places of destination. Though there are few reliable accounts of their work in those remote American haunts, during the first six years of the present century, the main facts of their life-history are now well known, and we are able to trace their experiments, step by step, from the time when they constructed their first simple aeroplane down to the appearance of the marvellous biplane which has made them world-famed. For some time the Wrights experimented with a glider, with which they accomplished even more wonderful results than those obtained by Lilienthal. These two young American engineers--bicycle-makers by trade--were never in a hurry. Step by step they made progress, first with kites, then with small gliders, and ultimately with a large one. The latter was launched into the air by men running forward with it until sufficient momentum had been gained for the craft to go forward on its own account. The first aeroplane made by the two brothers was a very simple one, as was the method adopted to balance the craft. There were two main planes made of long spreads of canvas arranged one above another, and on the lower plane the pilot lay. A little plane in front of the man was known as the ELEVATOR, and it could be moved up and down by the pilot; when the elevator was tilted up, the aeroplane ascended, when lowered, the machine descended. At the back was a rudder, also under control of the pilot. The pilot's feet, in a modern aeroplane, rest upon a bar working on a central swivel, and this moves the rudder. To turn to the left, the left foot is moved forward; to turn to the right the right foot. But it was in the balancing control of their machine that the Wrights showed such great ingenuity. Running from the edges of the lower plane were some wires which met at a point where the pilot could control them. The edges of the plane were flexible; that is, they could be bent slightly either up or down, and this movement of the flexible plane is known as WING WARPING. You know that when a cyclist is going round a curve his machine leans inwards. Perhaps some of you have seen motor races, such as those held at Brooklands; if so, you must have noticed that the track is banked very steeply at the corners, and when the motorist is going round these corners at, say, 80 miles an hour, his motor makes a considerable angle with the level ground, and looks as if it must topple over. The aeroplane acts in a similar manner, and, unless some means are taken to prevent it, it will turn over. Let us now see how the pilot worked the "Wright" glider. Suppose the machine tilted down on one side, while in the air, the pilot would pull down, or warp, the edges of the planes on that side of the machine which was the lower. By an ingenious contrivance, when one side was warped down, the other was warped up, with the effect that the machine would be brought back into a horizontal position. (As we shall return to the subject of wing warping in a later chapter, we need not discuss it further here.) It must not be imagined that as soon as the Wrights had constructed a glider fitted with this clever system of controlling mechanism they could fly when and where they liked. They had to practise for two or three years before they were satisfied with the results of their experiments: neglecting no detail, profiting by their failures, and moving logically from step to step. They never attempted an experiment rashly: there was always a reason for what they did. In fact, their success was due to systematic progress, achieved by wonderful perseverance. But now, for a short time, we must leave the pioneer work of the Wright brothers, and turn to the invention of the petrol engine as applied to the motor car, an invention which was destined to have far-reaching results on the science of aviation. CHAPTER XX. The Internal-combustion Engine We have several times remarked upon the great handicap placed upon the pioneers of aviation by the absence of a light but powerful motor engine. The invention of the internal-combustion engine may be said to have revolutionized the science of flying; had it appeared a century ago, there is no reason to doubt that Sir George Cayley would have produced an aeroplane giving as good results as the machines which have appeared during the last five or six years. The motor engine and the aeroplane are inseparably connected; one is as necessary to the other as clay is to the potter's wheel, or coal to the blast-furnace. This being the case, it is well that we trace briefly the development of the engine during the last quarter of a century. The original mechanical genius of the motoring industry was Gottlieb Daimler, the founder of the immense Daimler Motor Works of Coventry. Perhaps nothing in the world of industry has made more rapid strides during the last twenty years than automobilism. In 1900 our road traction was carried on by means of horses; now, especially in the large cities, it is already more than half mechanical, and at the present rate of progress it bids fair to be soon entirely horseless. About the year 1885 Daimler was experimenting with models of a small motor engine, and the following year he fitted one of his most successful models to a light wagonette. The results were so satisfactory, that in 1888 he took out a patent for an internal-combustion engine--as the motor engine is technically called--and the principle on which this engine was worked aroused great enthusiasm on the Continent. Soon a young French engineer, named Levassor, began to experiment with models of motor engines, and in 1889 he obtained, with others, the Daimler rights to construct similar engines in France. From now on, French engineers began to give serious attention to the new engine, and soon great improvements were made in it. All this time Britain held aloof from the motor-car; indeed, many Britons scoffed at the idea of mechanically-propelled vehicles, saying that the time and money required for their development would be wasted. During the years 1888-1900 strange reports of smooth-moving, horseless cars, frequently appearing in public in France, began to reach Britain, and people wondered if the French had stolen a march on us, and if there were anything in the new invention after all. Our engineers had just begun to grasp the immense possibilities of Daimler's engine, but the Government gave them no encouragement. At length the Hon. Evelyn Ellis, one of the first British motorists, introduced the "horseless carriage" into this country, and the following account of his early trips, which appeared in the Windsor and Eton Express of 27th July, 1895, may be interesting. "If anyone cares to run over to Datchet, they will see the Hon. Evelyn Ellis, of Rosenau, careering round the roads, up hill and down dale, and without danger to life or limb, in his new motor carriage, which he brought over a short time ago from Paris. "In appearance it is not unlike a four-wheeled dog-cart, except that the front part has a hood for use on long 'driving' tours, in the event of wet weather; it will accommodate four persons, one of whom, on the seat behind, would, of course, be the 'groom', a misnomer, perhaps, for carriage attendant. Under the front seat are receptacles, one for tools with which to repair damages, in the event of a breakdown on the road, and the other for a store of oil, petroleum, or naphtha in cans, from which to replenish the oil tank of the carriage on the journey, if it be a long one. "Can it be easily driven? We cannot say that such a vehicle would be suitable for a lady, unless rubber-tyred wheels and other improvements are made to the carriage, for a grim grip of the steering handle and a keen eye are necessary for its safe guidance, more especially if the high road be rough. It never requires to be fed, and as it is, moreover, unsusceptible of fatigue, it is obviously the sort of vehicle that should soon achieve a widespread popularity in this country. "It is a splendid hill climber, and, in fact, such a hill as that of Priest Hill (a pretty good test of its capabilities) shows that it climbs at a faster pace than a pedestrian can walk. "A trip from Rosenau to Old Windsor, to the entrance of Beaumont College, up Priest Hill, descending the steep, rough, and treacherous hill on the opposite side by Woodside Farm, past the workhouse, through old Windsor, and back to Rosenau within an hour, amply demonstrated how perfectly under control this carriage is, while the sensation of being whirled rapidly along is decidedly pleasing." Another pioneer of motorism was the Hon. C. S. Rolls, whose untimely death at Bournemouth in 1910, while taking part in the Bournemouth aviation meeting, was deeply deplored all over the country. Mr. Rolls made a tour of the country in a motor-car in 1895, with the double object of impressing people with the stupidity of the law with regard to locomotion, and of illustrating the practical possibilities of the motor. You may know that Mr. Rolls was the first man to fly across the Channel, and back again to Dover, without once alighting. CHAPTER XXI. The Internal-combustion Engine(Cont.) I suppose many of my readers are quite familiar with the working of a steam-engine. Probably you have owned models of steam-engines right from your earliest youth, and there are few boys who do not know how the railway engine works. But though you may be quite familiar with the mechanism of this engine, it does not follow that you know how the petrol engine works, for the two are highly dissimilar. It is well, therefore, that we include a short description of the internal-combustion engine such as is applied to motor-cars, for then we shall be able to understand the principles of the aeroplane engine. At present petrol is the chief fuel used for the motor engine. Numerous experiments have been tried with other fuels, such as benzine, but petrol yields the best results. Petrol is distilled from oil which comes from wells bored deep down in the ground in Pennsylvania, in the south of Russia, in Burma, and elsewhere. Also it is distilled in Scotland from oil shale, from which paraffin oil and wax and similar substances are produced. When the oil is brought to the surface it contains many impurities, and in its native form is unsuitable for motor engines. The crude oil is composed of a number of different kinds of oil; some being light and clear, others heavy and thick. To purify the oil it is placed in a large metal vessel or "still". Steam is first passed over the oil in the still, and this changes the lightest of the oils into vapours. These vapours are sent through a series of pipes surrounded with cold water, where they are cooled and become liquid again. Petrol is a mixture of these lighter products of the oil. If petrol be placed in the air it readily turns into a vapour, and this vapour is extremely inflammable. For this reason petrol is always kept in sealed tins, and very large quantities are not allowed to be stored near large towns. The greatest care has to be exercised in the use of this "unsafe" spirit. For example, it is most dangerous to smoke when filling a tank with petrol, or to use the spirit near a naked light. Many motor-cars have been set on fire through the petrol leaking out of the tank in which it is carried. The tank which contains the petrol is placed under one of the seats of the motor-car, or at the rear; if in use on a motor-cycle it is arranged along the top bar of the frame, just in front of the driver. This tank is connected to the "carburettor", a little vessel having a small nozzle projecting upwards in its centre. The petrol trickles from the tank into the carburettor, and is kept at a constant level by means of a float which acts in a very similar way to the ballcock of a water cistern. The carburettor is connected to the cylinder of the engine by another pipe, and there is valve which is opened by the engine itself and is closed by a spring. By an ingenious contrivance the valve is opened when the piston moves out of the cylinder, and a vacuum is created behind it and in the carburettor. This carries a fine spray of petrol to be sucked up through the nozzle. Air is also sucked into the carburettor, and the mixture of air and petrol spray produces an inflammable vapour which is drawn straight into the cylinder of the engine. As soon as the piston moves back, the inlet valve is automatically closed and the vapour is compressed into the top of the cylinder. This is exploded by an electric spark, which is passed between two points inside the cylinder, and the force of the explosion drives the piston outwards again. On its return the "exhaust" or burnt gases are driven out through another valve, known as the "exhaust" valve. Whether the engine has two, four, or six cylinders, the car is propelled in a similar way for all the pistons assist in turning one shaft, called the engine shaft, which runs along the centre of the car to the back axle. The rapid explosions in the cylinder produce great heat, and the cylinders are kept cool by circulating water round them. When the water has become very hot it passes through a number of pipes, called the "radiator", placed in front of the car; the cold air rushing between the coils cools the water, so that it can be used over and over again. No water is needed for the engine of a motor cycle. You will notice that the cylinders are enclosed by wide rings of metal, and these rings are quite sufficient to radiate the heat as quickly as it is generated. CHAPTER XXII. The Aeroplane Engine We have seen that a very important part of the internal-combustion engine, as used on the motor-car, is the radiator, which prevents the engine from becoming overheated and thus ceasing to work. The higher the speed at which the engine runs the hotter does it become, and the greater the necessity for an efficient cooling apparatus. But the motor on an aeroplane has to do much harder work than the motor used for driving the motor-car, while it maintains a much higher speed. Thus there is an even greater tendency for it to become overheated; and the great problem which inventors of aeroplane engines have had to face is the construction of a light but powerful engine equipped with some apparatus for keeping it cool. Many different forms of aeroplane engines have been invented during the last few years. Some inventors preferred the radiator system of cooling the engine, but the tank containing the water, and the radiator itself, added considerably to the weight of the motor, and this, of course, was a serious drawback to its employment. But in 1909 there appeared a most ingeniously-constructed engine which was destined to take a very prominent part in the progress of aviation. This was the famous "Gnome" engine, by means of which races almost innumerable have been won, and amazing records established. We have already referred to the engine shaft of the motor-car, which is revolved by the pistons of the various fixed cylinders. In all aeroplane engines which had appeared before the Gnome the same principle of construction had been adopted; that is to say, the cylinders were fixed, and the engine shaft revolved. But in the Gnome engine the reverse order of things takes place; the shaft is fixed, and the cylinders fly round it at a tremendous speed. Thus the rapid whirl in the air keeps the engine cool, and cumbersome tanks and unwieldy radiators can be dispensed with. This arrangement enabled the engine to be made very light and yet be of greater horse-power than that attained by previously-existing engines. A further very important characteristic of the rotary-cylinder engine is that no flywheel is used; in a stationary engine it has been found necessary to have a fly-wheel in addition to the propeller. The rotary-cylinder engine acts as its own fly-wheel, thus again saving considerable weight. The new engine astonished experts when they first examined it, and all sorts of disasters to it were predicted. It was of such revolutionary design that wiseacres shook their heads and said that any pilot who used it would be constantly in trouble with it. But during the last few years it has passed from one triumph to another, commencing with a long-distance record established by Henri Farman at Rheims, in 1909. It has since been used with success by aviators all the world over. That in the Aerial Derby of 1913--which was flown over a course Of 94 miles around London--six of the eleven machines which took part in the race were fitted with Gnome engines, and victory was achieved by Mr. Gustav Hamel, who drove an 80-horse-power Gnome, is conclusive evidence of the high value of this engine in aviation. CHAPTER XXIII. A Famous British Inventor of Aviation Engines In the general design and beauty of workmanship involved in the construction of aeroplanes, Britain is now quite the equal of her foreign rivals; even in engines we are making extremely rapid progress, and the well-known Green Engine Company, profiting by the result of nine years' experience, are able to turn out aeroplane engines as reliable, efficient, and as light in pounds weight per horse-power as any aero engine in existence. In the early days of aviation larger and better engines of British make specially suited for aeroplanes were our most urgent need. The story of the invention of the "Green" engine is a record of triumph over great difficulties. Early in 1909--the memorable year when M. Bleriot was firing the enthusiasm of most engineers by his cross-Channel flight; when records were being established at Rheims; and when M. Paulhan won the great prize of L10,000 for the London to Manchester flight--Mr. Green conceived a number of ingenious ideas for an aero engine. One of Mr. Green's requirements was that the cylinders should be made of cast-steel, and that they should come from a British foundry. The company that took the work in hand, the Aster Company, had confidence in the inventor's ideas. It is said that they had to waste 250 castings before six perfect cylinders were produced. It is estimated that the first Green engine cost L6000. These engines can be purchased for less than L500. The closing months of 1909 saw the Green engine firmly established. In October of that year Mr. Moore Brabazon won the first all-British competition of L1000 offered by the Daily Mail for the first machine to fly a circular mile course. His aeroplane was fitted with a 60-horse-power Green aero engine. In the same year M. Michelin offered L1000 for a long-distance flight in all-British aviation; this prize was also won by Mr. Brabazon, who made a flight of 17 miles. Some of Colonel Cody's achievements in aviation were made with the Green engine. In 1910 he succeeded in winning both the duration and cross-country Michelin competitions, and in 1911 he again accomplished similar feats. In this year he also finished fourth in the all-round-Britain race. This was a most meritorious performance when it is remembered that his Cathedral weighed nearly a ton and a half, and that the 60-horse-power Green was practically "untouched", to use an engineering expression, during the whole of the 1010-mile flight. The following year saw Cody winning another Michelin prize for a cross-country competition. Here he made a flight of over 200 miles, and his high opinion of the engine may be best described in the letter he wrote to the company, saying: "If you kept the engine supplied from without with petrol and oil, what was within would carry you through". But the pinnacle of Mr. Green's fame as an inventor was reached in 1913, when Mr. Harry Hawker made his memorable waterplane flight from Cowes to Lough Shinny, an account of which appears in a later chapter. His machine was fitted with a 100-horse-power Green, and with it he flew 1043 miles of the 1540-miles course. Though the complete course was not covered, neither Mr. Sopwith--who built the machine and bore the expenses of the flight--nor Mr. Hawker attached any blame to the engine. At a dinner of the Aero Club, given in 1914, Mr. Sopwith was most enthusiastic in discussing the merits of the "Green", and after Harry Hawker had recovered from the effects of his fall in Lough Shinny he remarked in reference to the engine: "It is the best I have ever met. I do not know any other that would have done anything like the work." At the same time that this race was being held the French had a competition from Paris to Deauville, a distance of about 160 miles. When compared with the time and distance covered by Mr. Hawker, the results achieved by the French pilots, flying machines fitted with French engines, were quite insignificant; thus proving how the British industry had caught up, and even passed, its closest rivals. In 1913 Mr. Grahame White, with one of the 100-horse-power "Greens" succeeded in winning the duration Michelin with a flight of over 300 miles, carrying a mechanic and pilot, 85 gallons of petrol, and 12 gallons of lubricating oil. Compulsory landings were made every 63 miles, and the engine was stopped. In spite of these trying conditions, the engine ran, from start to finish, nearly nine hours without the slightest trouble. Sufficient has been said to prove conclusively that the thought and labour expended in the perfecting of the Green engine have not been fruitless. CHAPTER XXIV. The Wright Biplane (Camber of Planes) Now that the internal-combustion engine had arrived, the Wrights at once commenced the construction of an aeroplane which could be driven by mechanical power. Hitherto, as we have seen, they had made numerous tests with motorless gliders; but though these tests gave them much valuable information concerning the best methods of keeping their craft on an even keel while in the air, they could never hope to make much progress in practical flight until they adopted motor power which would propel the machine through the air. We may assume that the two brothers had closely studied the engines patented by Daimler and Levassor, and, being of a mechanical turn of mind themselves, they were able to build their own motor, with which they could make experiments in power-driven flight. Before we study the gradual progress of these experiments it would be well to describe the Wright biplane. The illustration facing p. 96 shows a typical biplane, and though there are certain modifications in most modern machines, the principles upon which it was built apply to all aeroplanes. The two main supporting planes, A, B, are made of canvas stretched tightly across a light frame, and are slightly curved, or arched, from front to back. This curve is technically known as the CAMBER, and upon the camber depend the strength and speed of the machine. If you turn back to Chapter XVII you will see that the plane is modelled after the wing of a bird. It has been found that the lifting power of a plane gradually dwindles from the front edge--or ENTERING EDGE, as it is called--backwards. For this reason it is necessary to equip a machine with a very long, narrow plane, rather than with a comparatively broad but short plane. Perhaps a little example will make this clear. Suppose we had two machines, one of which was fitted with planes 144 feet long and 1 foot wide, and the other with planes 12 feet square. In the former the entering edge of the plane would be twelve times as great as in the latter, and the lifting power would necessarily be much greater. Thus, though both machines have planes of the same area, each plane having a surface of 144 square feet, yet there is a great difference in the "lift" of the two. But it is not to be concluded that the back portion of a plane is altogether wasted. Numerous experiments have taught aeroplane constructors that if the plane were slightly curved from front to back the rear portion of the plane also exercised a "lift"; thus, instead of the air being simply cut by the entering edge of the plane, it is driven against the arched back of the plane, and helps to lift the machine into the air, and support it when in flight. There is also a secondary lifting impulse derived from this simple curve. We have seen that the air which has been cut by the front edge of the plane pushes up from below, and is arrested by the top of the arch, but the downward dip of the rear portion of the plane is of service in actually DRAWING THE AIR FROM ABOVE. The rapid air stream which has been cut by the entering edge passes above the top of the curve, and "sucks up", as it were, so that the whole wing is pulled upwards. Thus there are two lifting impulses: one pushing up from below, the other sucking up from above. It naturally follows that when the camber is very pronounced the machine will fly much slower, but will bear a greater weight than a machine equipped with planes having little or no camber. On high-speed machines, which are used chiefly for racing purposes, the planes have very little camber. This was particularly noticeable in the monoplane piloted by Mr. Hamel in the Aerial Derby of 1913: the wings of this machine seemed to be quite flat, and it was chiefly because of this that the pilot was able to maintain such marvellous speed. The scientific study of the wing lift of planes has proceeded so far that the actual "lift" can now be measured, providing the speed of the machine is known, together with the superficial area of the planes. The designer can calculate what weight each square foot of the planes will support in the air. Thus some machines have a "lift" of 9 or 10 pounds to each square foot of wing surface, while others are reduced to 3 or 4 pounds per square foot. CHAPTER XXV. The Wright Biplane (Cont.) The under part of the frame of the Wright biplane, technically known as the CHASSIS, resembled a pair of long "runner" skates, similar to those used in the Fens for skating races. Upon those runners the machine moved along the ground when starting to fly. In more modern machines the chassis is equipped with two or more small rubber-tyred wheels on which the machine runs along the ground before rising into the air, and on which it alights when a descent is made. You will notice that the pilot's seat is fixed on the lower plane, and almost in the centre of it, while close by the engine is mounted. Alongside the engine is a radiator which cools the water that has passed round the cylinder of the engine in order to prevent them from becoming overheated. Above the lower plane is a similar plane arranged parallel to it, and the two are connected by light upright posts of hickory wood known as STRUTS. Such an aeroplane as this, which is equipped with two main planes, known as a BIPLANE. Other types of air-craft are the MONOPLANE, possessing one main plane, and the TRIPLANE, consisting of three planes. No practical machine has been built with more than three main planes; indeed, the triplane is now almost obsolete. The Wrights fitted their machine with two long-bladed wooden screws, or propellers, which by means of chains and sprocket-wheels, very like those of a bicycle, were driven by the engine, whose speed was about 1200 revolutions a minute. The first motor engine used by these clever pioneers had four cylinders, and developed about 20 horsepower. Nowadays engines are produced which develop more than five times that power. In later machines one propeller is generally thought to be sufficient; in fact many constructors believe that there is danger in a two-propeller machine, for if one propeller got broken, the other propeller, working at full speed, would probably overturn the machine before the pilot could cut off his engine. Beyond the propellers there are two little vertical planes which can be moved to one side or the other by a control lever in front of the pilot's seat. These planes or rudders steer the machine from side to side, answering the same purpose as the rudder of a boat. In front of the supporting planes there are two other horizontal planes, arranged one above the other; these are much smaller than the main planes, and are known as the ELEVATORS. Their function is to raise or lower the machine by catching the air at different angles. Comparison with a modern biplane, such as may be seen at an aerodrome on any "exhibition" day, will disclose several marked differences in construction between the modern type and the earlier Wright machine, though the central idea is the same. CHAPTER XXVI. How the Wrights launched their Biplane Those of us who have seen an aeroplane rise from the ground know that it runs quickly along for 50 or 60 yards, until sufficient momentum has been gained for the craft to lift itself into the air. The Wrights, as stated, fitted their machine with a pair of launching runners which projected from the under side of the lower plane like two very long skates, and the method of launching their craft was quite different from that followed nowadays. The launching apparatus consisted of a wooden tower at the starting end of the launching ways--a wooden rail about 60 or 70 feet in length. To the top of the tower a weight of about 1/2 ton was suspended. The suspension rope was led downwards over pulleys, thence horizontally to the front end and back to the inner end of the railway, where it was attached to the aeroplane. A small trolley was fitted to the chassis of the machine and this ran along the railway. To launch the machine, which, of course, stood on the rail, the propellers were set in motion, and the 1/2-ton weight at the top of the tower was released. The falling weight towed the aeroplane rapidly forward along the rail, with a velocity sufficient to cause it to glide smoothly into the air at the other end of the launching ways. By an ingenious arrangement the trolley was left behind on the railway. It will at once occur to you that there were disadvantages in this system of commencing a flight. One was that the launching apparatus was more or less a fixture. At any rate it could not be carried about from place to place very readily: Supposing the biplane could not return to its starting-point, and the pilot was forced to descend, say, 10 or 12 miles away: in such a case it would be necessary to tow the machine back to the launching ways, an obviously inconvenient arrangement, especially in unfavourable country. For some time the "wheeled" chassis has been in universal use, but in a few cases it has been thought desirable to adopt a combination of runners and wheels. A moderately firm surface is necessary for the machine to run along the ground; if the ground be soft or marly the wheels would sink in the soil, and serious accidents have resulted from the sudden stoppage of the forward motion due to this cause. With their first power-driven machine the Wrights made a series of very fine flights, at first in a straight line. In 1904 they effected their first turn. By the following year they had made such rapid progress that they were able to exceed a distance of 20 miles in one flight, and keep up in the air for over half an hour at a time. Their manager now gave their experiments great publicity, both in the American and European Press, and in 1908 the brothers, feeling quite sure of their success, emerged from a self-imposed obscurity, and astonished the world with some wonderful flights, both in America and on the French flying ground at Issy. A great loss to aviation occurred on 30th May, 1912, when Wilbur Wright died from an attack of typhoid fever. His work is officially commemorated in Britain by an annual Premium Lecture, given under the auspices of the Aeronautical Society. CHAPTER XXVII. The First Man to Fly in Europe In November, 1906, nearly the whole civilized world was astonished to read that a rich young Brazilian aeronaut, residing in France, had actually succeeded in making a short flight, or, shall we say, an enormous "hop", in a heavier-than-air machine. This pioneer of aviation was M. Santos Dumont. For five or six years before his experiments with the aeroplane he had made a great many flights in balloons, and also in dirigible balloons. He was the son of well-to-do parents--his father was a successful coffee planter--and he had ample means to carry on his costly experiments. Flying was Santos Dumont's great hobby. Even in boyhood, when far away in Brazil, he had been keenly interested in the work of Spencer, Green, and other famous aeronauts, and aeronautics became almost a passion with him. Towards the end of the year 1898 he designed a rather novel form of air-ship. The balloon was shaped like an enormous cigar, some 80 feet long, and it was inflated with about 6000 cubic feet of hydrogen. The most curious contrivance, however, was the motor. This was suspended from the balloon, and was somewhat similar to the small motor used on a motor-cycle. Santos Dumont sat beside this motor, which worked a propeller, and this curious craft was guided several times by the inventor round the Botanical Gardens in Paris. About two years after these experiments the science of aeronautics received very valuable aid from M. Deutsch, a member of the French Aero Club. A prize of about L4000 was offered by this gentleman to the man who should first fly from the Aero Club grounds at Longchamps, double round the Eiffel Tower, and then sail back to the starting-place. The total distance to be flown was rather more than 3 miles, and it was stipulated that the journey--which could be made either in a dirigible air-ship or a flying machine--should be completed within half an hour. This munificent offer at once aroused great enthusiasm among aeronauts and engineers throughout the whole of France, and, to a lesser degree, in Britain. Santos Dumont at once set to work on another air-ship, which was equipped with a much more powerful motor than he had previously used. In July, 1901, his arrangements were completed, and he made his first attempt to win the prize. The voyage from Longchamps to the Eiffel Tower was made in very quick time, for a favourable wind speeded the huge balloon on its way. The pilot was also able to steer a course round the tower, but his troubles then commenced. The wind was now in his face, and his engine-a small motor engine of about 15 horse-power-was unable to produce sufficient power to move the craft quickly against the wind. The plucky inventor kept fighting against the-breeze, and at length succeeded in returning to his starting-point; but he had exceeded the time limit by several minutes and thus, was disqualified for the prize. Another attempt was made by Santos Dumont about a month later. This time, however, he was more unfortunate, and he had a marvellous escape from death. As on the previous occasion he got into great difficulties when sailing against the wind on the return journey, and his balloon became torn, so that the gas escaped and the whole craft crashed down on the house-tops. Eyewitnesses of the accident expected to find the gallant young Brazilian crushed to death; but to their great relief he was seen to be hanging to the car, which had been caught upon the buttress of a house. Even now he was in grave peril, but after a long delay he was rescued by means of a rope. It might be thought that such an accident would have deterred the inventor from making further attempts on the prize; but the aeronaut seemed to be well endowed with the qualities of patience and perseverance and continued to try again. Trial after trial was made, and numerous accidents took place. On nearly every occasion it was comparatively easy to sail round the Tower, but it was a much harder task to sail back again. At length in October, 1901, he was thought to have completed the course in the allotted time; but the Aero Club held that he had exceeded the time limit by forty seconds. This decision aroused great indignation among Parisians--especially among those who had watched the flight--many of whom were convinced that the journey had been accomplished in the half-hour. After much argument the committee which had charge of the race, acting on the advice of M. Deutsch, who was very anxious that the prize should be awarded to Santos Dumont, decided that the conditions of the flight had been complied with, and that the prize had been legitimately won. It is interesting to read that the famous aeronaut divided the money among the poor. But important though Santos Dumont's experiments were with the air-ship, they were of even greater value when he turned his attention to the aeroplane. One of his first trials with a heavier-than-air machine was made with a huge glider, which was fitted with floats. The curious craft was towed along the River Seine by a fast motor boat named the Rapiere, and it actually succeeded in rising into the air and flying behind the boat like a gigantic kite. 12th November, 1906, is a red-letter day in the history of aviation, for it was then that Santos Dumont made his first little flight in an aeroplane. This took place at Bagatelle, not far from Paris. Two months before this the airman had succeeded in driving his little machine, called the Bird of Prey, many yards into the air, and "11 yards through the air", as the newspapers reported; but the craft was badly smashed. It was not until November that the first really satisfactory flight took place. A description of this flight appeared in most of the European newspapers, and I give a quotation from one of them: "The aeroplane rose gracefully and gently to a height of about 15 feet above the earth, covering in this most remarkable dash through the air a distance of about 700 feet in twenty-one seconds. "It thus progressed through the atmosphere at the rate of nearly 30 miles an hour. Nothing like this has ever been accomplished before.... The aeroplane has now reached the practical stage." The dimensions of this aeroplane were: Length 32 feet Greatest width 39 feet Weight with one passenger 465 pounds Speed 30 miles an hour A modern aeroplane with airman and passenger frequently weighs over 1 ton, and reaches a speed of over 60 miles an hour. It is interesting to note that Santos Dumont, in 1913--that is, only seven years after his flight in an aeroplane at Bagatelle made him world-famous--announced his intention of again taking an active part in aviation. His purpose was to make use of aeroplanes merely for pleasure, much as one might purchase a motor-car for the same object. Could the intrepid Brazilian in his wildest dreams have foreseen the rapid advance of the last eight years? In 1906 no one had flown in Europe; by 1914 hundreds of machines were in being, in which the pilots were no longer subject to the wind's caprices, but could fly almost where and when they would. Frenchmen have honoured, and rightly honoured, this gallant and picturesque figure in the annals of aviation, for in 1913 a magnificent monument was unveiled in France to commemorate his pioneer work. CHAPTER XXVIII. M. Bleriot and the Monoplane If the Wright brothers can lay claim to the title of "Fathers of the Biplane", then it is certain that M. Bleriot, the gallant French airman, can be styled the "Father of the Monoplane." For five years--1906 to 1910--Louis Bleriot's name was on everybody's lips in connection with his wonderful records in flying and skilful feats of airmanship. Perhaps the flight which brought him greatest renown was that accomplished in July, 1909, when he was the first man to cross the English Channel by aeroplane. This attempt had been forestalled, although unsuccessfully, by Hubert Latham, a daring aviator who is best known in Lancashire by his flight in 1909 at Blackpool in a wind which blew at the rate of nearly 40 miles an hour--a performance which struck everyone with wonder in these early days of aviation. Latham attempted, on an Antoinette monoplane, to carry off the prize of L1000 offered by the proprietors of the Daily Mail. On the first occasion he fell in mid-Channel, owing to the failure of his motor, and was rescued by a torpedo-boat. His machine was so badly damaged during the salving operations that another had to be sent from Paris, and with this he made a second attempt, which was also unsuccessful. Meanwhile M. Bleriot had arrived on the scene; and on 25th July he crossed the Channel from Calais to Dover in thirty-seven minutes and was awarded the L1000 prize. Bleriot's fame was now firmly established, and on his return to France he received a magnificent welcome. The monoplane at once leaped into favour, and the famous "bird man" had henceforth to confine his efforts to the building of machines and the organization of flying events. He has since established a large factory in France and inaugurated a flying school at Pau. All the time that the Wrights were experimenting with their glider and biplane in America, and the Voisin brothers were constructing biplanes in France, Bleriot had been giving earnest attention to the production of a real "bird" machine, provided with one pair of FLAPPING wings. We know now that such an aeroplane is not likely to be of practical use, but with quiet persistence Bleriot kept to his task, and succeeded in evolving the famous Antoinette monoplane, which more closely resembles a bird than does any other form of air-craft. In the illustration of the Bleriot monoplane here given you will notice that there is one main plane, consisting of a pair of highly-cambered wings; hence the name "MONOplane". At the rear of the machine there is a much smaller plane, which is slightly cambered; this is the elevating plane, and it can be tilted up or down in order to raise or lower the machine. Remember that the elevating plane of a biplane is to the front of the machine and in the monoplane at the rear. The small, upright plane G is the rudder, and is used for steering the machine to the right or left. The long narrow body or framework of the monoplane is known as the FUSELAGE. By a close study of the illustration, and the description which accompanies it, you will understand how the machine is driven. The main plane is twisted, or warped, when banking, much in the same way that the Wright biplane is warped. Far greater speed can be obtained from the monoplane than from the biplane, chiefly because in the former machine there is much less resistance to the air. Both height and speed records stand to the credit of the monoplane. The enormous difference in the speeds of monoplanes and biplanes can be best seen at a race meeting at some aerodrome. Thus at Hendon, when a speed handicap is in progress, the slow biplanes have a start of one or two laps over the rapid little monoplanes in a six-lap contest, and it is most amusing to see the latter dart under, or over, the more cumbersome biplane. Recently however, much faster biplanes have been built, and they bid fair to rival the swiftest monoplanes in speed. There is, however, one serious drawback to the use of the monoplane: it is far more dangerous to the pilot than is the biplane. Most of the fatal accidents in aviation have been caused through mishaps to monoplanes or their engines, and chiefly for this reason the biplane has to a large extent supplanted the monoplane in warfare. The biplane, too, is better adapted for observation work, which is, after all, the chief use of air-craft. In a later chapter some account will be given of the three types of aeroplane which the war has evolved--the general-purposes machine, the single-seater "fighter", and those big bomb-droppers, the British Handley Page and the German Gotha. CHAPTER XXIX. Henri Farman and the Voisin Biplane The coming of the motor engine made events move rapidly in the world of aviation. About the year 1906 people's attention was drawn to France, where Santos Dumont was carrying out the wonderful experiments which we have already described. Then came Henri Farman, who piloted the famous biplane built by the Voisin brothers in 1907; an aeroplane destined to bring world-wide renown to its clever constructors and its equally clever and daring pilot. There were notable points of distinction between the Voisin biplane and that built by the Wrights. The latter, as we have seen, had two propellers; the former only one. The launching skids of the Wright biplane gave place to wheels on Farman's machine. One great advantage, however, possessed by the early Wright biplane over its French rivals, was in its greater general efficiency. The power of the engine was only about one-half of the power required in certain of the French designs. This was chiefly due to the use of the launching rail, for it needed much greater motor power to make a machine rise from the ground by its own motor engine than when it received a starting lift from a falling weight. Even in our modern aeroplanes less engine power is required to drive the craft through the air than to start from the ground. Farman achieved great fame through his early flights, and, on 13th January, 1908, at the flying ground at Issy, in France, he won the prize of L2000, offered by MM. Deutsch and Archdeacon to the first aviator who flew a circular kilometre. In July of the same year he won another substantial prize given by a French engineer, M. Armengaud, to the first pilot who remained aloft for a quarter of an hour. Probably an even greater performance was the cross-country flight made by Farman about three months later. In the flight he passed over hills, valleys, rivers, villages, and woods on his journey from Chalons to Rheims, which he accomplished in twenty minutes. In the early models of the Voisin machine there were fitted between the two main planes a number of vertical planes, as shown clearly in the illustration facing p. 160. It was thought that these planes would increase the stability of the machine, independent of the skill of the operator, and in calm weather they were highly effective. Their great drawback, however, was that when a strong side wind caught them the machine was blown out of its course. Subsequently Farman considerably modified the early-type Voisin biplane, as shown by the illustration facing p. 160. The vertical planes were dispensed with, and thus the idea of automatic stability was abandoned. But an even greater distinction between the Farman biplane and that designed by the Wrights was in the adoption of a system of small movable planes, called AILERONS, fixed at extremities of the main planes, instead of the warping controls which we have already described. The ailerons, which are adapted to many of our modern aeroplanes, are really balancing flaps, actuated by a control lever at the right side of the pilot's seat, and the principle on which they are worked is very similar to that employed in the warp system of lateral stability. CHAPTER XXX. A Famous British Inventor About the time that M. Bleriot was developing his monoplane, and Santos Dumont was astonishing the world with his flying feats at Bagatelle, a young army officer was at work far away in a secluded part of the Scottish Highlands on the model of an aeroplane. This young man was Lieutenant J. W. Dunne, and his name has since been on everyone's lips wherever aviation is discussed. Much of Lieutenant Dunne's early experimental work was done on the Duke of Atholl's estate, and the story goes that such great secrecy was observed that "the tenants were enrolled as a sort of bodyguard to prevent unauthorized persons from entering". For some time the War Office helped the inventor with money, for the numerous tests and trials necessary in almost every invention before satisfactory results are achieved are very costly. Probably the inventor did not make sufficiently rapid progress with his novel craft, for he lost the financial help and goodwill of the Government for a time; but he plodded on, and at length his plans were sufficiently advanced for him to carry on his work openly. It must be borne in mind that at the time Dunne first took up the study of aviation no one had flown in Europe, and he could therefore receive but little help from the results achieved by other pilots and constructors. But in the autumn of 1913 Lieutenant Dunne's novel aeroplane was the talk of both Europe and America. Innumerable trials had been made in the remote flying ground at Eastchurch, Isle of Sheppey, and the machine became so far advanced that it made a cross-Channel flight from Eastchurch to Paris. It remained in France for some time, and Commander Felix, of the French Army, made many excellent flights in it. Unfortunately, however, when flying near Deauville, engine trouble compelled the officer to descend; but in making a landing in a very small field, not much larger than a tennis-court, several struts of the machine were damaged. It was at once seen that the aeroplane could not possibly be flown until it had been repaired and thoroughly overhauled. To do this would take several days, especially as there were no facilities for repairing the craft near by, and to prevent anyone from making a careful examination of the aeroplane, and so discovering the secret features which had been so jealously guarded, the machine was smashed up after the engine had been removed. At that time this was the only Dunne aeroplane in existence, but of course the plans were in the possession of the inventor, and it was an easy task to make a second machine from the same model. Two more machines were put in hand at Hendon, and a third at Eastchurch. On 18th October, 1913, the Dunne aeroplane made its first public appearance at Hendon, in the London aerodrome, piloted by Commander Felix. The most striking distinction between this and other biplanes is that its wings or planes, instead of reaching from side to side of the engine, stretch back in the form of the letter V, with the point of the V to the front. These wings extend so far to the rear that there is no need of a tail to the machine, and the elevating plane in front can also be dispensed with. This curious and unique design in aeroplane construction was decided upon by Lieutenant Dunne after a prolonged observation at close quarters of different birds in flight, and the inventor claims for his aeroplane that it is practically uncapsizable. Perhaps, however, this is too much to claim for any heavier-than-air machine; but at all events the new design certainly appears to give greater stability, and it is to be hoped that by this and other devices the progress of aviation will not in the future be so deeply tinged with tragedy. CHAPTER XXXI. The Romance of a Cowboy Aeronaut In the brief but glorious history of pioneer work in aviation, so far as it applies to this country, there is scarcely a more romantic figure to be found than Colonel Cody. It was the writer's pleasure to come into close contact with Cody during the early years of his experimental work with man-lifting box-kites at the Alexandra Park, London, and never will his genial smile and twinkling eye be forgotten. Cody always seemed ready to crack a joke with anyone, and possibly there was no more optimistic man in the whole of Britain. To the boys and girls of Wood Green he was a popular hero. He was usually clad in a "cowboy" hat, red flannel shirt, and buckskin breeches, and his hair hung down to his shoulders. On certain occasions he would give a "Wild West" exhibition at the Alexandra Palace, and one of his most daring tricks with the gun was to shoot a cigarette from a lady's lips. One could see that he was entire master of the rifle, and a trick which always brought rounds of applause was the hitting of a target while standing with his back to it, simply by the aid of a mirror held at the butt of his rifle. But it is of Cody as an aviator and aeroplane constructor that we wish to speak. For some reason or other he was generally the object of ridicule, both in the Press and among the public. Why this should have been so is not quite clear; possibly his quaint attire had something to do with it, and unfriendly critics frequently raised a laugh at his expense over the enormous size of his machines. So large were they that the Cody biplane was laughingly called the "Cody bus" or the "Cody Cathedral." But in the end Cody fought down ridicule and won fame, for in competition with some of the finest machines of the day, piloted by some of our most expert airmen, he won the prize of L5000 offered by the Government in 1912 in connection with the Army trials for aeroplanes. In these trials he astonished everyone by obtaining a speed of over 70 miles an hour in his biplane, which weighed 2600 pounds. In the opening years of the present century Cody spent much time in demonstrations with huge box-kites, and for a time this form of kite was highly popular with boys of North London. In these kites he made over two hundred flights, reaching, on some occasions, an altitude of over 2000 feet. At all times of the day he could have been seen on the slopes of the Palace Hill, hauling these strange-looking, bat-like objects backward and forward in the wind. Reports of his experiments appeared in the Press, but Cody was generally looked upon as a "crank". The War Office, however, saw great possibilities in the kites for scouting purposes in time of war, and they paid Cody L5000 for his invention. It is a rather romantic story of how Cody came to take up experimental work with kites, and it is repeated as it was given by a Mohawk chief to a newspaper representative. "On one occasion when Cody was in a Lancashire town with his Wild West show, his son Leon went into the street with a parrot-shaped kite. Leon was attired in a red shirt, cowboy trousers, and sombrero, and soon a crowd of youngsters in clogs was clattering after him. "'If a boy can interest a crowd with a little kite, why can't a man interest a whole nation?' thought Cody--and so the idea of man-lifting kites developed." In 1903 Cody made a daring but unsuccessful attempt to cross the Channel in a boat drawn by two kites. Had he succeeded he intended to cross the Atlantic by similar means. Later on, Cody turned his attention to the construction of aeroplanes, but he was seriously handicapped by lack of funds. His machines were built with the most primitive tools, and some of our modern constructors, working in well-equipped "shops", where the machinery is run by electric plant, would marvel at the work accomplished with such tools as those used by Cody. Most of Cody's flights were made on Laffan's Plain, and he took part in the great "Round Britain" race in 1911. It was characteristic of the man that in this race he kept on far in the wake of MM. Beaumont and Vedrines, though he knew that he had not the slightest chance of winning the prize; and, days after the successful pilot had arrived back at Brooklands, Cody's "bus" came to earth in the aerodrome. "It's dogged as does it," he remarked, "and I meant to do the course, even if I took a year over it." Of Cody's sad death at Farnborough, when practising in the ill-fated water-plane which he intended to pilot in the sea flight round Great Britain in 1913, we speak in a later chapter. CHAPTER XXXII. Three Historic Flights When the complete history of aviation comes to be written, there will be three epoch-making events which will doubtless be duly appreciated by the historian, and which may well be described as landmarks in the history of flight. These are the three great contests organized by the proprietors of the Daily Mail, respectively known as the "London to Manchester" flight, the "Round Britain flight in an aeroplane", and the "Water-plane flight round Great Britain." In any account of aviation which deals with the real achievements of pioneers who have helped to make the science of flight what it is to-day, it would be unfair not to mention the generosity of Lord Northcliffe and his co-directors of the Daily Mail towards the development of aviation in this country. Up to the time of writing, the sum of L24,750 has been paid by the Daily Mail in the encouragement of flying, and prizes to the amount of L15,000 are still on offer. In addition to these prizes this journal has maintained pilots who may be described as "Missionaries of Aviation". Perhaps the foremost of them is M. Salmet, who has made hundreds of flights in various parts of the country, and has aroused the greatest enthusiasm wherever he has flown. The progress of aviation undoubtedly owes a great deal to the Press, for the newspaper has succeeded in bringing home to most people the fact that the possession of air-craft is a matter of national importance. It was of little use for airmen to make thrilling flights up and down an aerodrome, with the object of interesting the general public, if the newspapers did not record such flights, and though in the very early days of aviation some newspapers adopted an unfriendly attitude towards the possibilities of practical aviation, nearly all the Press has since come to recognize the aeroplane as a valuable means of national defence. Right from the start the Daily Mail foresaw the importance of promoting the new science of flight by the award of prizes, and its public-spirited enterprise has done much to break up the prevailing apathy towards aviation among the British nation. If these three great events had been mere spectacles and nothing else--such as, for instance, that great horse-race known as "The Derby"--this chapter would never have been written. But they are most worthy of record because all three have marked clearly-defined stepping-stones in the progress of flight; they have proved conclusively that aviation is practicable, and that its ultimate entry into the busy life of the world is no more than a matter of perfecting details. The first L10,000 prize was offered in November, 1906, for a flight by aeroplane from London to Manchester in twenty-four hours, with not more than two stoppages en route. In 1910 two competitors entered the lists for the flight; one, an Englishman, Mr. Claude Grahame-White; the other, a Frenchman, M. Paulhan. Mr. Grahame-White made the first attempt, and he flew remarkably well too, but he was forced to descend at Lichfield--about 113 miles on the journey--owing to the high and gusty winds which prevailed in the Trent valley. The plucky pilot intended to continue the flight early the next morning, but during the night his biplane was blown over in a gale while it stood in a field, and it was so badly damaged that the machine had to be sent back to London to be repaired. This took so long that his French rival, M. Paulhan, was able to complete his plans and start from Hendon, on 27th April. So rapidly had Paulhan's machine been transported from Dover, and "assembled" at Hendon, that Mr. White, whose biplane was standing ready at Wormwood Scrubbs, was taken by surprise when he heard that his rival had started on the journey and "stolen a march on him", so to speak. Nothing daunted, however, the plucky British aviator had his machine brought out, and he went in pursuit of Paulhan late in the afternoon. When darkness set in Mr. White had reached Roade, but the French pilot was several miles ahead. Now came one of the most thrilling feats in the history of aviation. Mr. White knew that his only chance of catching Paulhan was to make a flight in the darkness, and though this was extremely hazardous he arose from a small field in the early morning, some hours before daybreak arrived, and flew to the north. His friends had planned ingenious devices to guide him on his way: thus it was proposed to send fast motor-cars, bearing very powerful lights, along the route, and huge flares were lighted on the railway; but the airman kept to his course chiefly by the help of the lights from the railway stations. Over hill and valley, forest and meadow, sleeping town and slumbering village, the airman flew, and when dawn arrived he had nearly overhauled his rival, who, in complete ignorance of Mr. White's daring pursuit, had not yet started. But now came another piece of very bad luck for the British aviator. At daybreak a strong wind arose, and Mr. White's machine was tossed about like a mere play-ball, so that he was compelled to land. Paulhan, however, who was a pilot with far more experience, was able to overcome the treacherous air gusts, and he flew on to Manchester, arriving there in the early morning. Undoubtedly the better pilot won, and he had a truly magnificent reception in Manchester and London, and on his return to France. But this historic contest laid the foundation of Mr. Grahame-White's great reputation as an aviator, and, as we all know, his fame has since become world-wide. CHAPTER XXXIII. Three Historic Flights (Cont.) About a month after Paulhan had won the "London to Manchester" race, the world of aviation, and most of the general public too, were astonished to read the announcement of another enormous prize. This time a much harder task was set, for the conditions of the contest stated that a circuit of Britain had to be made, covering a distance of about 1000 miles in one week, with eleven compulsory stops at fixed controls. This prize was offered on 22nd May, 1910, and in the following year seventeen competitors entered the lists. It says much for the progress of aviation at this time, when we read that, only a year before, it was difficult to find but two pilots to compete in the much easier race described in the last chapter. Much of this progress was undoubtedly due to the immense enthusiasm aroused by the success of Paulhan in the "London to Manchester" race. We will not describe fully the second race, because, though it was of immense importance at the time, it has long since become a mere episode. Rarely has Britain been in such great excitement as during that week in July, 1911. Engine troubles, breakdowns, and other causes soon reduced the seventeen competitors to two only: Lieutenant Conneau, of the French Navy-who flew under the name of M. Beaumont--and M. Vedrines. Neck to neck they flew--if we may be allowed this horse-racing expression--over all sorts of country, which was quite unknown to them. Victory ultimately rested with Lieutenant Conneau, who, on 26th July, 1911, passed the winning-post at Brooklands after having completed the course in the magnificent time of twenty-two hours, twenty-eight minutes, averaging about 45 miles an hour for the whole journey. M. Vedrines, though defeated, made a most plucky fight. Conneau's success was due largely to his ability to keep to the course--on two or three occasions Vedrines lost his way--and doubtless his naval training in map-reading and observation gave him the advantage over his rival. The third historic flight was made by Mr. Harry Hawker, in August, 1913. This was an attempt to win a prize of L5000 offered by the proprietors of the Daily Mail for a flight round the British coasts. The route was from Cowes, in the Isle of Wight, along the southern and eastern coasts to Aberdeen and Cromarty, thence through the Caledonian Canal to Oban, then on to Dublin, thence to Falmouth, and along the south coast to Southampton Water. Two important conditions of the contest were that the flight was to be made in an all-British aeroplane, fitted with a British engine. Hitherto our aeroplane constructors and engine companies were behind their rivals across the Channel in the building of air-craft and aerial engines, and this country freely acknowledged the merits and enterprise of French aviators. Though in the European War it was afterwards proved that the British airman and constructor were the equals if not the superiors of any in the world, at the date of this contest they were behind in many respects. As these conditions precluded the use of the famous Gnome engine, which had won so many contests, and indeed the employment of any engine made abroad, the competitors were reduced to two aviation firms; and as one or these ultimately withdrew from the contest the Sopwith Aviation Company of Kingston-on-Thames and Brooklands entered a machine. Mr. T. Sopwith chose for his pilot a young Australian airman, Mr. Harry Hawker. This skilful airman came with three other Australians to this country to seek his fortune about three years before. He was passionately devoted to mechanics, and, though he had had no opportunity of flying in his native country, he had been intensely interested in the progress of aviation in France and Britain, and the four friends set out on their long journey to seek work in aeroplane factories. All four succeeded, but by far the most successful was Harry Hawker. Early in 1913 Mr. Sopwith was looking out for a pilot, and he engaged Hawker, whom he had seen during some good flying at Brooklands. In a month or two he was engaged in record breaking, and in June, 1913, he tried to set up a new British height record. In his first attempt he rose to 11,300 feet; but as the carburettor of the engine froze, and as the pilot himself was in grave danger of frost-bite, he descended. About a fortnight later he rose 12,300 feet above sea-level, and shortly afterwards he performed an even more difficult test, by climbing with three passengers to an altitude of 8500 feet. With such achievements to his name it was not in the least surprising that Mr. Sopwith's choice of a pilot for the water-plane race rested on Hawker. His first attempt was made on 16th August, when he flew from Southampton Water to Yarmouth--a distance of about 240 miles--in 240 minutes. The writer, who was spending a holiday at Lowestoft, watched Mr. Hawker go by, and his machine was plainly visible to an enormous crowd which had lined the beach. To everyone's regret the pilot was affected with a slight sunstroke when he reached Yarmouth, and another Australian airman, Mr. Sidney Pickles, was summoned to take his place. This was quite within the rules of the contest, the object of which was to test the merits of a British machine and engine rather than the endurance and skill of a particular pilot. During the night a strong wind arose, and next morning, when Mr. Pickles attempted to resume the flight, the sea was too rough for a start to be made, and the water-plane was beached at Gorleston. Mr. Hawker quickly recovered from his indisposition, and on Monday, 25th August, he, with a mechanic as passenger, left Cowes about five o'clock in the morning in his second attempt to make a circuit of Britain. The first control was at Ramsgate, and here he had to descend in order to fulfil the conditions of the contest. Ramsgate was left at 9.8, and Yarmouth, the next control, was reached at 10.38. So far the engine, built by Mr. Green, had worked perfectly. About an hour was spent at Yarmouth, and then the machine was en route to Scarborough. Haze compelled the pilot to keep close in to the coast, so that he should not miss the way, and a choppy breeze some what retarded the progress of the machine along the east coast. About 2.40 the pilot brought his machine to earth, or rather to water, at Scarborough, where he stayed for nearly two hours. Mr. Hawker's intention was to reach Aberdeen, if possible, before nightfall, but at Seaham he had to descend for water, as the engine was becoming uncomfortably hot, and the radiator supply of water was rapidly diminishing. This lost much valuable time, as over an hour was spent here, and it had begun to grow dark before the journey was recommenced. About an hour after resuming his journey he decided to plane down at the fishing village of Beadwell, some 20 miles south of Berwick. At 8.5 on Tuesday morning the pilot was on his way to Aberdeen, but he had to descend and stay at Montrose for about half an hour, and Aberdeen was reached about 11 a.m. His Scottish admirers, consisting of quite 40,000 people at Aberdeen alone, gave him a most hearty welcome, and sped him on his way about noon. Some two hours later Cromarty was reached. Now commenced the most difficult part of the course. The Caledonian Canal runs among lofty mountains, and the numerous air-eddies and swift air-streams rushing through the mountain passes tossed the frail craft to and fro, and at times threatened to wreck it altogether. On some occasions the aeroplane was tossed up over 1000 feet at one blow; at other times it was driven sideways almost on to the hills. From Cromarty to Oban the journey was only about 96 miles, but it took nearly three hours to fly between these places. This slow progress seriously jeopardized the pilot's chances of completing the course in the allotted time, for it was his intention to make the coast of Ireland by nightfall. But as it was late when Oban was reached he decided to spend the night there. Early the following morning he left for Dublin, 222 miles away. Soon a float was found to be waterlogged and much valuable time was, spent in bailing it dry. Then a descent had to be made at Kiells, in Argyllshire, because a valve had gone wrong. Another landing was made at Larne, to take aboard petrol. As soon as the petrol tanks were filled and the machine had been overhauled the pilot got on his way for Dublin. For over two hours he flew steadily down the Irish coast, and then occurred one of those slight accidents, quite insignificant in themselves, but terribly disastrous in their results. Mr. Hawker's boots were rubber soled and his foot slipped off the rudder bar, so that the machine got out of control and fell into the sea at Lough Shinny, about 15 miles north of Dublin. At the time of the accident the pilot was about 50 feet above the water, which in this part of the Lough is very shallow. The machine was completely wrecked, and Mr. Hawker's mechanic was badly cut about the head and neck, besides having his arm broken. Mr. Hawker himself escaped injury. All Britons deeply sympathized with his misfortune, and much enthusiasm, was aroused when the proprietors of the Daily Mail presented the skilful and courageous pilot with a cheque for L1000 as a consolation gift. In a later chapter some account will be given of the tremendous development of the aeroplane during four years of war. But it is fitting that to the three historic flights detailed above there should be added the sensational exploits of the Marchese Giulio Laureati in 1917. This intrepid Italian airman made a non-stop journey from Turin to Naples and back, a distance of 920 miles. A month later he flew from Turin to Hounslow, a distance of 656 miles, in 7 hours 22 minutes. His machine was presented to the British Air Board by the Italian Government. CHAPTER XXXIV. The Hydroplane and Air-boat One of the most recent developments in aviation is the hydroplane, or water-plane as it is most commonly called. A hydroplane is an aeroplane fitted with floats instead of wheels, so that it will rise from, or alight upon, the surface of the water. Often water-planes have their floats removed and wheels affixed to the chassis, so that they may be used over land. From this you may think that the construction of a water-plane is quite a simple task; but such is not the case. The fitting of floats to an aeroplane has called for great skill on the part of the constructor, and many difficulties have had to be overcome. Those of you who have seen an acroplane rise from the ground know that the machine runs very quickly over the earth at a rapidly-increasing speed, until sufficient momentum is obtained for the machine to lift itself into the air. In the case of the water-plane the pilot has to glide or "taxi" by means of a float or floats over the waves until the machine acquires flying speed. Now the land resistance to the rubber-tired wheels is very small when compared with the water resistance to the floats, and the faster the craft goes the greater is the resistance. The great problem which the constructor has had to solve is to build a machine fitted with floats which will leave the water easily, which will preserve the lateral balance of the machine, and which will offer the minimum resistance in the air. A short flat-bottomed float, such as that known as the Fabre, is good at getting off from smooth water, but is frequently damaged when the sea is rough. A long and narrow float is preferable for rough water, as it is able to cut through the waves; but comparatively little "lift" is obtained from it. Some designers have provided their water-planes with two floats; others advocate a single float. The former makes the machine more stable when at rest on the water, but a great rawback is that the two-float machine is affected by waves more than a machine fitted with a single float; for one float may be on the crest of a wave and the other in the dip. This is not the case with the single-float water-plane, but on the other hand this type is less stable than the other when at rest. Sometimes the floats become waterlogged, and so add considerably to the weight of the machine. Thus in Mr. Hawker's flight round Britain, the pilot and his passenger had to pump about ten gallons of water out of one of the floats before the machine could rise properly. Floats are usually made with watertight compartments, and are composed of several thin layers of wood, riveted to a wooden framework. There is another technical question to be considered in the fixing of the floats, namely, the fore-and-aft balance of the machine in the air. The propeller of a water-plane has to be set higher than that of a land aeroplane, so that it may not come into contact with the waves. This tends to tip the craft forwards, and thus make the nose of the float dig in the water. To overcome this the float is set well forward of the centre of gravity, and though this counteracts the thrust when the craft "taxies" along the waves, it endangers its fore-and-aft stability when aloft. CHAPTER XXXV. A Famous British Inventor of the Water-plane Though Harry Hawker made such a brilliant and gallant attempt to win the L5000 prize, we must not forget that great credit is due to Mr. Sopwith, who designed the water-plane, and to Mr. Green, the inventor of the engine which made such a flight possible, and enabled the pilot to achieve a feat never before approached in any part of the world. The life-story of Mr. "Tommy" Sopwith is almost a romance. As a lad he was intensely interested in mechanics, and we can imagine him constructing all manner of models, and enquiring the why and the wherefore of every mechanical toy with which he came into contact. At the early age of twenty-one he commenced a motor business, but about this time engineers and mechanics all over the country were becoming greatly interested in the practical possibilities of aviation. Mr. Sopwith decided to learn to fly, and in 1910, after continued practice in a Howard Wright biplane, he had become a proficient pilot. So rapid was his progress that by the end of the year he had won the magnificent prize of L4000 generously offered by Baron de Forest for the longest flight made by an all-British machine from England to the Continent. In this flight he covered 177 miles, from Eastchurch, Isle of Sheppey, to the Belgian frontier, in three and a half hours. If Mr. Sopwith had been in any doubt as to the wisdom of changing his business this remarkable achievement alone must have assured him that his future career lay in aviation. In 1911 he was graciously received by King George V at Windsor Castle, after having flown from Brooklands and alighted on the East Terrace of the famous castle. In the same year he visited America, and astonished even that go-ahead country with some skilful flying feats. To show the practical possibilities of the aeroplane he overtook the liner Olympic, after she had left New York harbour on her homeward voyage, and dropped aboard a parcel addressed to a passenger. On his return to England he competed in the first Aerial Derby, the course being a circuit of London, representing a distance of 81 miles. In this race he made a magnificent flight in a 70-horse-power Bleriot monoplane, and came in some fifteen minutes before Mr. Hamel, the second pilot home. So popular was his victory that Mr. Grahame-White and several other officials of the London Aerodrome carried him shoulder high from his machine. From this time we hear little of Mr. Sopwith as a pilot, for, like other famous airmen, such as Louis Bleriot, Henri Farman, and Claude Grahame-White, who jumped into fame by success in competition flying, he has retired with his laurels, and now devotes his efforts to the construction of machines. He bids fair to be equally successful as a constructor of air-craft as he formerly was as a pilot of flying machines. The Sopwith machines are noted for their careful design and excellent workmanship. They are made by the Sopwith Aviation Company, Ltd., whose works are at Kingston-on-Thames. Several water-planes have been built there for the Admiralty, and land machines for the War Office. Late in 1913 Mr. Hawker left Britain for Australia to give demonstrations in the Sopwith machine to the Government of his native country. A fine list of records has for long stood to the credit of the Sopwith biplane. Among these are: British Height Record (Pilot only) 11,450 feet " " " (Pilot and 1 Passenger) 12,900 " " " " (Pilot and 2 Passengers) 10,600 " World's " " (Pilot and 3 Passengers) 8,400 " Many of the Sopwith machines used in the European War were built specially to withstand rough climate and heavy winds, and thus they were able to work in almost every kind of weather. It was this fact, coupled with the indomitable spirit of adventure inherent in men of British race, that made British airmen more than hold their own with both friend and foe in the war. CHAPTER XXXVI. Sea-planes for Warfare "Even in the region of the air, into which with characteristic British prudence we have moved with some tardiness, the Navy need not fear comparison with the Navy of any other country. The British sea-plane, although still in an empirical stage, like everything else in this sphere of warlike operations, has reached a point of progress in advance of anything attained elsewhere. "Our hearts should go out to-night to those brilliant officers, Commander Samson and his band of brilliant pioneers, to whose endeavours, to whose enterprise, to whose devotion it is due that in an incredibly short space of time our naval aeroplane service has been raised to that primacy from which it must never be cast down. "It is not only in naval hydroplanes that we must have superiority. The enduring safety of this country will not be maintained by force of arms unless over the whole sphere of aerial development we are able to make ourselves the first nation. That will be a task of long duration. Many difficulties have to be overcome. Other countries have started sooner. The native genius of France, the indomitable perseverance of Germany, have produced results which we at the present time cannot equal." So said Mr. Winston Churchill at the Lord Mayor's Banquet held in London in 1913, and I have quoted his speech because such a statement, made at such a time, clearly shows the attitude of the British Government toward this new arm of Imperial Defence. In bygone days the ocean was the great highway which united the various quarters of the Empire, and, what was even more important from the standpoint of our country's defence, it was a formidable barrier between Britain and her Continental neighbours, "Which serves it in the office of a wall Or as a moat defensive to a house." But the ocean is no longer the only highway, for the age of aerial navigation has arrived, and, as one writer says: "Every argument which impelled us of old to fight for the dominion of the sea has apparently been found valid in relation to the supremacy of the air." From some points of view this race between nations for naval and aerial supremacy may be unfortunate, but so long as the fighting instinct of man continues in the human race, so long as rivalry exists between nations, so long must we continue to strengthen our aerial position. Britain is slow to start on any great venture where great change is effected. Our practice is rather to wait and see what other nations are doing; and there is something to be said for this method of procedure. In the art of aviation, and in the construction of air-craft, our French, German, and American rivals were very efficient pacemakers in the aerial race for supremacy, and during the years 1909-12 we were in grave peril of being left hopelessly behind. But in 1913 we realized the vital importance to the State of capturing the first place in aviation, particularly that of aerial supremacy at sea, for the Navy is our first line of defence. So rapid has been our progress that we are quite the equal of our French and German rivals in the production of aeroplanes, and in sea-planes we are far ahead of them, both in design and construction, and the war has proved that we are ahead in the art of flight. The Naval Air Service before the war had been establishing a chain of air stations round the coast. These stations are at Calshot, on Southampton Water, the Isle of Grain, off Sheerness, Leven, on the Firth of Forth, Cromarty, Yarmouth, Blythe, and Cleethorpes. But what is even more important is the fact that the Government is encouraging sea-plane constructors to go ahead as fast as they can in the production of efficient machines. Messrs. Short Brothers, the Sopwith Aviation Company, and Messrs. Roe are building high-class machines for sea work which can beat anything turned out abroad. Our newest naval water-planes are fitted with British-built wireless apparatus of great range of action, and Messrs. Short Brothers are at the present time constructing for the Admiralty, at their works in the Isle of Sheppey, a fleet of fighting water-planes capable of engaging and destroying the biggest dirigible air-ships. In 1913 aeroplanes took a very prominent part in our naval manoeuvres, and the cry of the battleship captains was: "Give us water-planes. Give us them of great size and power, large enough to carry a gun and gun crew, and capable of taking twelve-hour cruises at a speed much greater than that of the fastest dirigible air-ship, and we shall be on the highroad to aerial supremacy at sea." The Admiralty, acting on this advice, at once began to co-operate with the leading firms of aeroplane constructors, and at a great rate machines of all sizes and designs have been turned out. There were light single-seater water-planes able to maintain a speed of over a mile a minute; there were also larger machines for long-distance flying which could carry two passengers. The machines were so designed that their wings could be folded back along their bodies, and their wires, struts, and so on packed into the main parts of the craft, so that they were almost as compact as the body of a bird at rest on its perch, and they took up comparatively little space on board ship. A brilliantly executed raid was carried out on Cuxhaven, an important German naval base, by seven British water-planes, on Christmas Day, 1914. The water-planes were escorted across the North Sea by a light cruiser and destroyer force, together with submarines. They left the war-ships in the vicinity of Heligoland and flew over Cuxhaven, discharging bombs on points of military significance, and apparently doing considerable damage to the docks and shipping. The British ships remained off the coast for three hours in order to pick up the returning airmen, and during this time they were attacked by dirigibles and submarines, without, however, suffering damage. Six of the sea-planes returned safely to the ships, but one was wrecked in Heligoland Bight. But the present efficient sea-plane is a development of the war. In the early days many of the raids of the "naval wing" were carried out in land-going aeroplanes. Now the R.N.A.S., which came into being as a separate service in July, 1914, possess two main types of flying machine, the flying boat and the twin float, both types being able to rise from and alight upon the sea, just as an aeroplane can leave and return to the land. Many brilliant raids stand to the credit of the R.N.A.S. The docks at Antwerp, submarine bases at Ostend, and all Germany's fortified posts on the Belgian coast, have seldom been free from their attentions. And when, under the stress of public outcry, the Government at last gave its consent to a measure of "reprisals" it was the R.N.A.S. which opened the campaign with a raid upon the German town of Mannheim. As the war continued the duties of the naval pilot increased. He played a great part in the ceaseless hunt for submarines. You must often have noticed how easily fish can be seen from a bridge which are quite invisible from the banks of the river. On this principle the submarine can be "spotted" by air-craft, and not until the long silence upon naval affairs is broken, at the end of the war, shall we know to what extent we are indebted to naval airmen for that long list of submarines which, in the words of the German reports, "failed to return" to their bases. In addition to the "Blimps" of which mention has been made, the Royal Naval Air Service are in charge of air-ships known as the Coast Patrol type, which work farther out to sea, locating minefields and acting as scouts for the great fleet of patrol vessels. The Service has gathered laurels in all parts of the globe, its achievements ranging from an aerial food service into beleaguered Kut to the discovery of the German cruiser Konigsberg, cunningly camouflaged up an African creek. CHAPTER XXXVII. The First Man to Fly in Britain The honour of being the first man to fly in this country is claimed by Mr. A. V. Roe, head of the well-known firm A. V. Roe & Co., of Manchester, and constructor of the highly-efficient Avro machines. As a youth Roe's great hobby was the construction of toy models of various forms of machinery, and later on he achieved considerable success in the production of aeroplane models. All manner of novelties were the outcome of his fertile brain, and as it has been truly remarked, "his novelties have the peculiarity, not granted to most pioneers, of being in one respect or another ahead of his contemporaries." In addition, he studied the flight of birds. In the early days of aviation Mr. Roe was a firm believer in the triplane form of machine, and his first experiments in flight were made with a triplane equipped with an engine which developed only 9 horse-power. Later on, he turned his attention to the biplane, and with this craft he has been highly successful. The Avro biplane, produced in 1913, was one of the very best machines which appeared in that eventful year. The Daily Telegraph, when relating its performances, said: "The spectators at Hendon were given a remarkable demonstration of the wonderful qualities of this fine Avro biplane, whose splendid performances stamped it as one of the finest aeroplanes ever designed, if not indeed the finest of all". This craft is fitted with an 80-horse-power Gnome engine, and is probably the fastest passenger-carrying biplane of its type in the world. Its total weight, with engine, fuel for three hours, and a passenger, is 1550 pounds, and it has a main-plane surface of 342 square feet. Not only can the biplane maintain such great speed, but, what is of great importance for observation purposes, it can fly at the slow rate of 30 miles per hour. We have previously remarked that a machine is kept up in the air by the speed it attains; if its normal flying speed be much reduced the machine drops to earth unless the rate of flying is accelerated by diving, or other means. What Harry Hawker is to Mr. Sopwith so is F. P. Raynham to Mr. Roe. This skilful pilot learned to fly at Brooklands, and during the last year or two he has been continuously engaged in testing Avro machines, and passing them through the Army reception trials. In the "Aerial Derby" of 1913 Mr. Raynham piloted an 80-horse-power Avro biplane, and came in fourth. CHAPTER XXXVIII. The Royal Flying Corps and Royal Naval Air Service The year 1912 was marked by the institution of the Royal Flying Corps. The new corps, which was so soon to make its mark in the greatest of all wars, consisted of naval and military "wings". In those early days the head-quarters of the corps were at Eastchurch, and there both naval and military officers were trained in aviation. In an arm of such rapid--almost miraculous--development as Service flying to go back a period of six years is almost to take a plunge into ancient history. Designs, engines, guns, fittings, signals of those days are now almost archaic. The British engine of reliable make had not yet been evolved, and the aeroplane generally was a conglomerate affair made up of parts assembled from various parts of the Continent. The present-day sea-plane was yet to come, and naval pilots shared the land-going aeroplanes of their military brethren. In the days when Bleriot provided a world sensation by flying across the Channel the new science was kept alive mainly by the private enterprise of newspapers and aeroplane manufacturers. The official attitude, as is so often the case in the history of inventions, was as frigid as could be. The Government looked on with a cold and critical eye, and could not be touched either in heart or in pocket. But with the institution of the Royal Flying Corps the official heart began to warm slightly, and certain tests were laid down for those manufacturers who aspired to sell their machines to the new arm of the Service. These tests, providing for fuel capacity up to 4.0 miles, speeds up to 85 miles an hour, and heights up to 3500 feet, would now be regarded as very elementary affairs. "Looping the loop" was still a dangerous trick for the exhibiting airman and not an evolution; while the "nose-dive" was an uncalculated entry into the next world. The first important stage in the history of the new arm was reached in July, 1914, when the wing system was abolished, and the Royal Naval Air Service became a separate unit of the Imperial Forces. The first public appearance of the sailor airmen was at a proposed review of the fleet by the King at a test mobilization. The King was unable to attend, but the naval pilots carried out their part of the programme very creditably considering the polyglot nature of their sea-planes. A few weeks later and the country was at war. There can be no doubt that the Great War has had an enormous forcing influence upon the science of aviation. In times of peace the old game of private enterprise and official neglect would possibly have been carried on in well-marked stages. But with the terrific incentive of victory before them, all Governments fostered the growth of the new arm by all the means in their power. It became a race between Allied and enemy countries as to who first should attain the mastery of the air. The British nation, as usual, started well behind in the race, and their handicap would have been increased to a dangerous extent had Germany not been obsessed by the possibilities of the air-ship as opposed to the aeroplane. Fortunately for us the Zeppelin, as has been described in an earlier chapter, failed to bring about the destruction anticipated by its inventor, and so we gained breathing space for catching up the enemy in the building and equipment of aeroplanes and the training of pilots and observers. War has set up its usual screens, and the writer is only permitted a very vague and impressionistic picture of the work of the R.F.C. and R.N.A.S. Numerical details and localities must be rigorously suppressed. Descriptions of the work of the Flying Service must be almost as bald as those laconic reports sent in by naval and military airmen to head-quarters. But there is such an accomplishment as reading between the lines. The flying men fall naturally into two classes--pilots and observers. The latter, of course, act as aerial gunners. The pilots have to pass through three, and observers two, successive courses of training in aviation. Instruction is very detailed and thorough as befits a career which, in addition to embracing the endless problems of flight, demands knowledge of wireless telegraphy, photography, and machine gunnery. Many of the officers are drafted into the Royal Flying Corps from other branches of the Service, but there are also large numbers of civilians who take up the career. In their case they are first trained as cadets, and, after qualifying for commissions, start their training in aviation at one of the many schools which have now sprung up in all parts of the country. When the actual flying men are counted in thousands some idea may be gained of the great organization required for the Corps--the schools and flying grounds, the training and activities of the mechanics, the workshops and repair shops, the storage of spare parts, the motor transport, &c. As in other departments of the Service, women have come forward and are doing excellent and most responsible work, especially in the motor-transport section. A very striking feature of the Corps is the extreme youth of the members, many of the most daring fighters in the air being mere boys of twenty. The Corps has the very pick of the youth and daring and enterprise of the country. In the days of the old army there existed certain unwritten laws of precedence as between various branches of the Service. If such customs still prevail it is certain that the very newest arm would take pride of place. The flying man has recaptured some of the glamour and romance which encircled the knight-errant of old. He breathes the very atmosphere of dangerous adventure. Life for him is a series of thrills, any one of which would be sufficient to last the ordinary humdrum citizen for a lifetime. Small wonder that the flying man has captured the interest and affection of the people, and all eyes follow these trim, smart, desperadoes of the air in their passage through our cities. As regards the work of the flying man the danger curve seems to be changing. On the one hand the training is much more severe and exacting than formerly was the case, and so carries a greater element of danger. On the other hand on the battle-front fighting information has in great measure taken the place of the system of men going up "on their own". They are perhaps not so liable to meet with a numerical superiority on the part of enemy machines, which spelt for them almost certain destruction. For a long time the policy of silence and secrecy which screened "the front" from popular gaze kept us in ignorance of the achievements of our airmen. But finally the voice of the people prevailed in their demand for more enlightenment. Names of regiments began to be mentioned in connection with particular successes. And in the same way the heroes of the R.F.C. and R.N.A.S. were allowed to reap some of the laurels they deserved. It began to be recognized that publication of the name of an airman who had destroyed a Zeppelin, for instance, did not constitute any vital information to the enemy. In a recent raid upon London the names of the two airmen, Captain G. H. Hackwill, R.F.C., and Lieutenant C. C. Banks, R.F.C., who destroyed a Gotha, were given out in the House of Commons and saluted with cheers. In the old days the secretist party would have regarded this publication as a policy which led the nation in the direct line of "losing the war". In the annals of the Flying Service, where dare-devilry is taken as a matter of course and hairbreadth escapes from death are part of the daily routine, it is difficult to select adventures for special mention; but the following episodes will give a general idea of the work of the airman in war. The great feat of Sub-Lieutenant R. A. J. Warneford, R.N.A.S., who single-handed attacked and destroyed a Zeppelin, has already been referred to in Chapter XIII. Lieutenant Warneford was the second on the list of airmen who won the coveted Cross, the first recipient being Second-Lieutenant Barnard Rhodes-Moorhouse, for a daring and successful bomb-dropping raid upon Courtrai in April, 1915. As has happened in so many cases, the award to Lieutenant Rhodes-Moorhouse was a posthumous one, the gallant airman having been mortally wounded during the raid, in spite of which he managed by flying low to reach his destination and make his report. A writer of adventure stories for boys would be hard put to it to invent any situation more thrilling than that in which Squadron-Commander Richard Bell Davies, D.S.O., R.N., and Flight Sub-Lieutenant Gilbert Formby Smylie, R.N., found themselves while carrying out an air attack upon Ferrijik junction. Smylie's machine was subjected to such heavy fire that it was disabled, and the airman was compelled to plane down after releasing all his bombs but one, which failed to explode. The moment he alighted he set fire to his machine. Presently Smylie saw his companion about to descend quite close to the burning machine. There was infinite danger from the bomb. It was a question of seconds merely before it must explode. So Smylie rushed over to the machine, took hasty aim with his revolver, and exploded the bomb, just before the Commander came within the danger zone. Meanwhile the enemy had commenced to gather round the two airmen, whereupon Squadron-Commander Davies coolly took up the Lieutenant on his machine and flew away with him in safety back to their lines. Davies, who had already won the D.S.O., was given the V.C., while his companion in this amazing adventure was granted the Distinguished Service Cross. The unexpectedness, to use no stronger term, of life in the R.F.C. in war-time is well exemplified by the adventure which befell Major Rees. The pilot of a "fighter", he saw what he took to be a party of air machines returning from a bombing expedition. Proceeding to join them in the character of escort, Major Rees made the unpleasant discovery that he was just about to join a little party of ten enemy machines. But so far from being dismayed, the plucky airman actually gave battle to the whole ten. One he quickly drove "down and out", as the soldiers say. Attacked by five others, he damaged two of them and dispersed the remainder. Not content with this, he gave chase to two more, and only broke off the engagement when he had received a wound in the thigh. Then he flew home to make the usual laconic report. No record of heroism in the air could be complete without mention of Captain Ball, who has already figured in these pages. When awarded the V.C. Captain Ball was already the holder of the following honours: D.S.O., M.C., Cross of a Chevalier of the Legion of Honour, and the Russian order of St. George. This heroic boy of twenty was a giant among a company of giants. Here follows the official account which accompanied his award:-- "Lieutenant (temporary Captain) ALBERT BALL, D.S.O., M.C., late Notts and Derby Regiment, and R.F.C. "For most conspicuous and consistent bravery from April 25 to May 6, 1917, during which period Captain Ball took part in twenty-six combats in the air and destroyed eleven hostile aeroplanes, drove down two out of control, and forced several others to land. "In these combats Captain Ball, flying alone, on one occasion fought six hostile machines, twice he fought five, and once four. "While leading two other British aeroplanes he attacked an enemy formation of eight. On each of these occasions he brought down at least one enemy. "Several times his aeroplane was badly damaged, once so severely that but for the most delicate handling his machine would have collapsed, as nearly all the control wires had been shot away. On returning with a damaged machine, he had always to be restrained from immediately going out on another. "In all Captain Ball has destroyed forty-three German aeroplanes and one balloon, and has always displayed most exceptional courage, determination, and skill." So great was Captain Ball's skill as a fighter in the air that for a time he was sent back to England to train new pilots in the schools. But the need for his services at the front was even greater, and it jumped with his desires, for the whole tone of his letters breathes the joy he found in the excitements of flying and fighting. He declares he is having a "topping time", and exults in boyish fashion at a coming presentation to Sir Douglas Haig. It is not too much to say that the whole empire mourned when Captain Ball finally met his death in the air near La Bassee in May, 1917. CHAPTER XXXIX. Aeroplanes in the Great War "Aeroplanes and airships would have given us an enormous advantage against the Boers. The difficulty of laying ambushes and traps for isolated columns--a practice at which the enemy were peculiarly adept--would have been very much greater. Some at least of the regrettable reverses which marked the early stages of the campaign could in all probability have been avoided." So wrote Lord Roberts, our veteran field-marshal, in describing the progress of the Army during recent years. The great soldier was a man who always looked ahead. After his great and strenuous career, instead of taking the rest which he had so thoroughly earned, he spent laborious days travelling up and down the country, warning the people of danger ahead; exhorting them to learn to drill and to shoot; thus attempting to lay the foundation of a great civic army. But his words, alas! fell upon deaf ears--with results so tragic as hardly to bear dwelling upon. But even "Bobs", seer and true prophet as he was, could hardly have foreseen the swift and dramatic development of war in the air. He had not long been laid to rest when aeroplanes began to be talked about, and, what is more important, to be built, not in hundreds but in thousands. At the time of writing, when we are well into the fourth year of the war, it seems almost impossible for the mind to go back to the old standards, and to take in the statement that the number of machines which accompanied the original Expeditionary Force to France was eighty! Even if one were not entirely ignorant of the number and disposition of the aerial fighting forces over the world-wide battle-ground, the Defence of the Realm Act would prevent us from making public the information. But when, more than a year ago, America entered the war, and talked of building 10,000 aeroplanes, no one gasped. For even in those days one thought of aeroplanes not in hundreds but in tens of thousands. Before proceeding to give a few details of the most recent work of the Royal Flying Corps and Royal Naval Air Service, mention must be made of the armament of the aeroplane. In the first place, it should be stated that the war has gradually evolved three distinct types of flying machine: (1) the "general-purposes" aeroplane; (2) the giant bomb dropper; (3) the small single-seater "fighter". As the description implies, the first machine fills a variety of roles, and the duties of its pilots grow more manifold as the war progresses. "Spotting" for the artillery far behind the enemy's lines; "searching" for ammunition dumps, for new dispositions by the enemy of men, material, and guns; attacking a convoy or bodies of troops on the march; sprinkling new trenches with machine-gun fire, or having a go at an aerodrome--any wild form of aerial adventure might be included in the diary of the pilot of a "general-purposes" machine. It was in order to clear the air for these activities that the "fighter" came into being, and received its baptism of fire at the Battle of the Somme. At first the idea of a machine for fighting only, was ridiculed. Even the Germans, who, in a military sense, were awake and plotting when other nations were dozing in the sunshine of peace, did not think ahead and imagine the aerial duel between groups of aeroplanes armed with machine-guns. But soon the mastery of the air became of paramount importance, and so the fighter was evolved. Nobly, too, did the men of all nations rise to these heroic and dangerous opportunities. The Germans were the first to boast of the exploits of their fighting airmen, and to us in Britain the names of Immelmann and Bolcke were known long before those of any of our own fighters. The former claimed not far short of a hundred victims before he was at last brought low in June, 1916. His letters to his family were published soon after his death, and do not err on the side of modesty. On 11th August, 1915, he writes: "There is not much doing here. Ten minutes after Bolcke and I go up, there is not an enemy airman to be seen. The English seem to have lost all pleasure in flying. They come over very, very seldom." When allowance has been made for German brag, these statements throw some light upon the standard of British flying at a comparatively early date in the war. Certainly no German airman could have made any such complaint a year later. In 1917 the German airmen were given all the fighting they required and a bit over. Certainly a very different picture is presented by the dismal letters which Fritz sent home during the great Ypres offensive of August, 1917. In these letters he bewails the fact that one after another of his batteries is put out of action owing to the perfect "spotting" of the British airmen, and arrives at the sad conclusion that Germany has lost her superiority in the air. An account has already been given of the skill and prowess of Captain Ball. On his own count--and he was not the type of man to exaggerate his prowess--he found he had destroyed fifty machines, although actually he got the credit for forty-one. This slight discrepancy may be explained by the scrupulous care which is taken to check the official returns. The air fighter, though morally certain of the destruction of a certain enemy aeroplane, has to bring independent witnesses to substantiate his claim, and when out "on his own" this is no easy matter. Without this check, though occasionally it acts harshly towards the pilot, there might be a tendency to exaggerate enemy losses, owing to the difficulty of distinguishing between an aeroplane put out of action and one the pilot of which takes a sensational "nose dive" to get out of danger. One of the most striking illustrations of the growth of the aeroplane as a fighting force is afforded by the great increase in the heights at which they could scout, take photographs, and fight. In Sir John French's dispatches mention is made of bomb-dropping from 3000 feet. In these days the aerial battleground has been extended to anything up to 20,000 feet. Indeed, so brisk has been the duel between gun and aeroplane, that nowadays airmen have often to seek the other margin of safety, and can defy the anti-aircraft guns only by flying so low as just to escape the ground. The general armament of a "fighter" consists of a maxim firing through the propeller, and a Lewis gun at the rear on a revolving gun-ring. It is pleasant to record that the Allies kept well ahead of the enemy in their use of aerial photography. Before a great offensive some thousands of photographs had to be taken of enemy dispositions by means of cameras built into the aeroplanes. Plates were found to stand the rough usage better than films, and not for the first time in the history of mechanics the man beat the machine, a skilful operator being found superior to the ingenious automatic plate-fillers which had been devised. The counter-measure to this ruthless exposure of plans was camouflage. As if by magic-tents, huts, dumps, guns began, as it were, to sink into the scenery. The magicians were men skilled in the use of brush and paint-pot, and several leading figures in the world of art lent their services to the military authorities as directors of this campaign of concealment. In this connection it is interesting to note that both Admiralty and War Office took measures to record the pictorial side of the Great War. Special commissions were given to a notable band of artists working in their different "lines". An abiding record of the great struggle will be afforded by the black-and-white work of Muirhead Bone, James M'Bey, and Charles Pears; the portraits, landscapes, and seascapes of Sir John Lavery, Philip Connard, Norman Wilkinson, and Augustus John, who received his commission from the Canadian Government. CHAPTER XL. The Atmosphere and the Barometer For the discovery of how to find the atmospheric pressure we are indebted to an Italian named Torricelli, a pupil of Galileo, who carried out numerous experiments on the atmosphere toward the close of the sixteenth century. Torricelli argued that, as air is a fluid, if it had weight it could be made to balance another fluid of known weight. In his experiments he found that if a glass tube about 3 feet in length, open at one end only, and filled with mercury, were placed vertically with the open end submerged in a cup of mercury, some of the mercury in the tube descended into the cup, leaving a column of mercury about 30 inches in height in the tube. From this it was deduced that the pressure of air on the surface of the mercury in the cup forced it up the tube to the height Of 30 inches, and this was so because the weight of a column of air from the cup to the top of the atmosphere was only equal to that of a column of mercury of the same base and 30 inches high. Torricelli's experiment can be easily repeated. Take a glass tube about 3 feet long, closed at one end and open at the other; fill it as full as possible with mercury. Then close the open end with the thumb, and invert the tube in a basin of mercury so that the open end dips beneath the surface. The mercury in the tube will be found to fall a short distance, and if the height of the column from the surface of the mercury in the basin be measured you will find it will be about 30 inches. As the tube is closed at the top there is no downward pressure of air at that point, and the space above the mercury in the tube is quite empty: it forms a VACUUM. This vacuum is generally known as the TORRICELLIAN VACUUM, after the name of its discoverer. Suppose, now, a hole be bored through the top of the tube above the column of mercury, the mercury will immediately fall in the tube until it stands at the same level as the mercury in the basin, because the upward pressure of air through the liquid in the basin would be counterbalanced by the downward pressure of the air at the top, and the mercury would fall by its own weight. A few years later Professor Boyle proposed to use the instrument to measure the height of mountains. He argued that, since the pressure of the atmosphere balanced a column of mercury 30 inches high, it followed that if one could find the weight of the mercury column one would also find the weight of a column of air standing on a base of the same size, and stretching away indefinitely into space. It was found that a column of mercury in a tube having a sectional area of 1 square inch, and a height of 30 inches, weighed 15 pounds; therefore the weight of the atmosphere, or air pressure, at sea-level is about 15 pounds to the square inch. The ordinary mercury barometer is essentially a Torricellian tube graduated so that the varying heights of the mercury column can be used as a measure of the varying atmospheric pressure due to change of weather or due to alteration of altitude. If we take a mercury barometer up a hill we will observe that the mercury falls. The weight of atmosphere being less as we ascend, the column of mercury supported becomes smaller. Although the atmosphere has been proved to be over 200 miles high, it has by no means the same density throughout. Like all gases, air is subject to the law that the density increases directly as the pressure, and thus the densest and heaviest layers are those nearest the sea-level, because the air near the earth's surface has to support the pressure of all the air above it. As airmen rise into the highest portions of the atmosphere the height of the column of air above them decreases, and it follows that, having a shorter column of air to support, those portions are less dense than those lower down. So rare does the atmosphere become, when great altitudes are reached, that at a height of seven miles breathing is well-nigh impossible, and at far lower altitudes than this airmen have to be supported by inhalations of oxygen. One of the greatest altitudes was reached by two famous balloonists, Messrs. Coxwell and Glaisher. They were over seven miles in the air when the latter fell unconscious, and the plucky aeronauts were only saved by Mr. Coxwell pulling the valve line with his teeth, as all his limbs were disabled. CHAPTER XLI. How an Airman Knows what Height he Reaches One of the first questions the visitor to an aerodrome, when watching the altitude tests, asks is: "How is it known that the airman has risen to a height of so many feet?" Does he guess at the distance he is above the earth? If this were so, then it is very evident that there would be great difficulty in awarding a prize to a number of competitors each trying to ascend higher than his rivals. No; the pilot does not guess at his flying height, but he finds it by a height-recording instrument called the BAROGRAPH. In the last chapter we saw how the ordinary mercurial barometer can be used to ascertain fairly accurately the height of mountains. But the airman does not take a mercurial barometer up with him. There is for his use another form of barometer much more suited to his purpose, namely, the barograph, which is really a development of the aneroid barometer. The aneroid barometer (Gr. a, not; neros, moist) is so called because it requires neither mercury, glycerine, water, nor any other liquid in its construction. It consists essentially of a small, flat, metallic box made of elastic metal, and from which the air has been partially exhausted. In the interior there is an ingenious arrangement of springs and levers, which respond to atmospheric pressure, and the depression or elevation of the surface is registered by an index on the dial. As the pressure of the atmosphere increases, the sides of the box are squeezed in by the weight of the air, while with a decrease of pressure they are pressed out again by the springs. By means of a suitable adjustment the pointer on the dial responds to these movements. It is moved in one direction for increase of air pressure, and in the opposite for decreased pressure. The positions of the figures on the dial are originally obtained by numerous comparisons with a standard mercurial barometer, and the scale is graduated to correspond with the mercurial barometer. From the illustration here given you will notice the pointer and scale of the "A. G" aero-barograph, which is used by many of our leading airmen, and which, as we have said, is a development of the aneroid barometer. The need of a self-registering scale to a pilot who is competing in an altitude test, or who is trying to establish a height record, is self-evident. He need not interfere with the instrument in the slightest; it records and tells its own story. There is in use a pocket barograph which weighs only 1 pound, and registers up to 4000 feet. It is claimed for the "A. G." barograph that it is the most precise instrument of its kind. Its advantages are that it is quite portable--it measures only 6 1/4 inches in length, 3 1/2 inches in width, and 2 1/2 inches in depth, with a total weight of only 14 pounds--and that it is exceptionally accurate and strong. Some idea of the labour involved in its construction may be gathered from the fact that this small and insignificant-looking instrument, fitted in its aluminium case, costs over L8. CHAPTER XLII. How an Airman finds his Way In the early days of aviation we frequently heard of an aviator losing his way, and being compelled to descend some miles from his required destination. There are on record various instances where airmen have lost their way when flying over the sea, and have drifted so far from land that they have been drowned. One of the most notable of such disasters was that which occurred to Mr. Hamel in 1914, when he was trying to cross the English Channel. It is presumed that this unfortunate pilot lost his bearings in a fog, and that an accident to his machine, or a shortage of petrol, caused him to fall in the sea. There are several reasons why air pilots go out of their course, even though they are supplied with most efficient compasses. One cause of misdirection is the prevalence of a strong side wind. Suppose, for example, an airman intended to fly from Harwich to Amsterdam. A glance at the map will show that the latter place is almost due east of Harwich. We will assume that when the pilot leaves Earth at Harwich the wind is blowing to the east; that is, behind his back. Now, however strong a wind may be, and in whatever direction it blows, it always appears to be blowing full in a pilot's face. Of course this is due to the fact that the rush of the machine through the air "makes a wind", as we say. Much the same sort of thing is experienced on a bicycle; when out cycling we very generally seem to have a "head" wind. Suppose during his journey a very strong side wind sprang up over the North Sea. The pilot would still keep steering his craft due east, and it must be remembered that when well out at sea there would be no familiar landmarks to guide him, so that he would have to rely solely on his compass. It is highly probable that he would not feel the change of wind at all, but it is even more probable that when land was ultimately reached he would be dozens of miles from his required landing-place. Quite recently Mr. Alexander Gross, the well-known maker of aviation instruments, who is even more famous for his excellent aviation maps, claims to have produced an anti-drift aero-compass, which has been specially designed for use on aeroplanes. The chief advantages of this compass are that the dial is absolutely steady; the needle is extremely sensitive and shows accurately the most minute change of course; the anti-drift arrangement checks the slightest deviation from the straight course; and it is fitted with a revolving sighting arrangement which is of great importance in the adjustment of the instrument. Before the airman leaves Earth he sets his compass to the course to be steered, and during the flight he has only to see that the two boldly-marked north points--on the dial and on the outer ring--coincide to know that he is keeping his course. The north points are luminous, so that they are clearly visible at night. It is quite possible that if some of our early aviators had carried such a highly-efficient compass as this, their lives might have been saved, for they would not have gone so far astray in their course. The anti-drift compass has been adopted by various Governments, and it now forms part of the equipment of the Austrian military aeroplane. When undertaking cross-country flights over strange land an airman finds his way by a specially-prepared map which is spread out before him in an aluminium map case. From the illustration here given of an aviator's map, you will see that it differs in many respects from the ordinary map. Most British aviation maps are made and supplied by Mr Alexander Gross, of the firm of "Geographia", London. Many airmen seem to find their way instinctively, so to speak, and some are much better in picking out landmarks, and recognizing the country generally, than others. This is the case even with pedestrians, who have the guidance of sign-posts, street names, and so on to assist them. However accurately some people are directed, they appear to have the greatest difficulty in finding their way, while others, more fortunate, remember prominent features on the route, and pick out their course as accurately as does a homing pigeon. Large sheets of water form admirable "sign-posts" for an airman; thus at Kempton Park, one of the turning-points in the course followed in the "Aerial Derby", there are large reservoirs, which enable the airmen to follow the course at this point with the greatest ease. Railway lines, forests, rivers and canals, large towns, prominent structures, such as gasholders, chimney-stalks, and so on, all assist an airman to find his way. CHAPTER XLIII. The First Airman to Fly Upside Down Visitors to Brooklands aerodrome on 25th September, 1913, saw one of the greatest sensations in this or any other century, for on that date a daring French aviator, M. Pegoud, performed the hazardous feat of flying upside down. Before we describe the marvellous somersaults which Pegoud made, two or three thousand feet above the earth, it would be well to see what was the practical use of it all. If this amazing airman had been performing some circus trick in the air simply for the sake of attracting large crowds of people to witness it, and therefore being the means of bringing great monetary gain both to him and his patrons, then this chapter would never have been written. Indeed, such a risk to one's life, if there had been nothing to learn from it, would have been foolish. No; Pegoud's thrilling performance must be looked at from an entirely different standpoint to such feats of daring as the placing of one's head in the jaws of a lion, the traversing of Niagara Falls by means of a tight-rope stretched across them, and other similar senseless acts, which are utterly useless to mankind. Let us see what such a celebrated airman as Mr. Gustav Hamel said of the pioneer of upside-down flying. "His looping the loop, his upside-down flights, his general acrobatic feats in the air are all of the utmost value to pilots throughout the world. We shall have proof of this, I am sure, in the near future. Pegoud has shown us what it is possible to do with a modern machine. In his first attempt to fly upside down he courted death. Like all pioneers, he was taking liberties with the unknown elements. No man before him had attempted the feat. It is true that men have been upside down in the air; but they were turned over by sudden gusts of wind, and in most cases were killed. Pegoud is all the time rehearsing accidents and showing how easy it is for a pilot to recover equilibrium providing he remains perfectly calm and clear-headed. Any one of his extraordinary positions might be brought about by adverse elements. It is quite conceivable that a sudden gust of wind might turn the machine completely over. Hitherto any pilot in such circumstances would give himself up for lost. Pegoud has taught us what to do in such a case.... his flights have given us all a new confidence. "In a gale the machine might be upset at many different angles. Pegoud has shown us that it is easily possible to recover from such predicaments. He has dealt with nearly every kind of awkward position into which one might be driven in a gale of wind, or in a flight over mountains where air-currents prevail. "He has thus gained evidence which will be of the utmost value to present and future pilots, and prove a factor of signal importance in the preservation of life in the air." Such words as these, coming from a man of Mr. Hamel's reputation as an aviator, clearly show us that M. Pegoud has a life-saving mission for airmen throughout the world. Let us stand, in imagination, with the enormous crowd of spectators who invaded the Surrey aerodrome on 25th September, and the two following days, in 1913. What an enormous crowd it was! A line of motor-cars bordered the track for half a mile, and many of the spectators were busy city men who had taken a hasty lunch and rushed off down to Weybridge to see a little French airman risk his life in the air. Thousands of foot passengers toiled along the dusty road from the paddock to the hangars, and thousands more, who did not care to pay the shilling entrance fee, stood closely packed on the high ground outside the aerodrome. Biplanes and monoplanes came driving through the air from Hendon, and airmen of world-wide fame, such as Sopwith, Hamel, Verrier, and Hucks, had gathered together as disciples of the great life-saving missionary. Stern critics these! Men who would ruthlessly expose any "faked" performance if need were! And where is the little airman while all this crowd is gathering? Is he very excited? He has never before been in England. We wonder if his amazing coolness and admirable control over his nerves will desert him among strange surroundings. Probably Pegoud was the coolest man in all that vast crowd. He seemed to want to hide himself from public gaze. Most of his time, was taken up in signing post-cards for people who had been fortunate enough to discover him in a little restaurant near which his shed was situated. At last his Bleriot monoplane was wheeled out, and he was strapped, or harnessed, into his seat. "Was the machine a 'freak' monoplane?" we wondered. We were soon assured that such was not the case. Indeed, as Pegoud himself says: "I have used a standard type of monoplane on purpose. Almost every aeroplane, if it is properly balanced, has just as good a chance as mine, and I lay particular stress on the fact that there is nothing extraordinary about my machine, so that no one can say my achievements are in any way faked." During the preliminary operations his patron, M. Bleriot, stood beside the machine, and chatted affably with the aviator. At last the signal was given for his ascent, and in a few moments Pegoud was climbing with the nose of his machine tilted high in the air. For about a quarter of an hour he flew round in ever-widening circles, rising very quietly and steadily until he had reached an altitude of about 4000 feet. A deep silence seemed to have settled on the vast crowd nearly a mile below, and the musical droning of his engine could be plainly heard. Then his movements began to be eccentric. First, he gave a wonderful exhibition of banking at right angles. Then, after about ten minutes, he shut off his engine, pitched downwards and gracefully righted himself again. At last the amazing feat began. His left wing was raised, his right wing dipped, and the nose of the machine dived steeply, and turned right round with the airman hanging head downwards, and the wheels of the monoplane uppermost. In this way he travelled for about a hundred yards, and then slowly righted the machine, until it assumed its normal position, with the engine again running. Twice more the performance was repeated, so that he travelled from one side of the aerodrome to the other--a distance of about a mile and a half. Next he descended from 4000 feet to about 1200 feet in four gigantic loops, and, as one writer said: "He was doing exactly what the clown in the pantomime does when he climbs to the top of a staircase and rolls deliberately over and over until he reaches the ground. But this funny man stopped before he reached the ground, and took his last flight as gracefully as a Columbine with outspread skirts." Time after time Pegoud made a series of S-shaped dives, somersaults, and spiral descents, until, after an exhibition which thrilled quite 50,000 people, he planed gently to Earth. Hitherto Pegoud's somersaults have been made by turning over from front to back, but the daring aviator, and others who followed him, afterwards turned over from right to left or from left to right. Pegoud claimed to have demonstrated that the aeroplane is uncapsizeable, and that if a parachute be attached to the fuselage, which is the equivalent of a life boat on board a ship, then every pilot should feel as safe in a heavier-than-air machine as in a motor-car. CHAPTER XLIV. The First Englishman to Fly Upside Down After M. Pegoud's exhibition of upside-down flying in this country it was only to be expected that British aviators would emulate his daring feat. Indeed, on the same day that the little Frenchman was turning somersaults in the air at Brooklands Mr. Hamel was asking M. Bleriot for a machine similar to that used by Pegoud, so that he might demonstrate to airmen the stability of the aeroplane in almost all conceivable positions. However, it was not the daring and skilful Hamel who had the honour of first following in Pegoud's footsteps, but another celebrated pilot, Mr. Hucks. Mr. Hucks was an interested spectator at Brooklands when Pegoud flew there in September, and he felt that, given similar conditions, there was no reason why he should not repeat Pegoud's performance. He therefore talked the matter over with M. Bleriot, and began practising for his great ordeal. His first feat was to hang upside-down in a chair supported by a beam in one of the sheds, so that he would gradually become accustomed to the novel position. For a time this was not at all easy. Have you ever tried to stand on your hands with your feet upwards for any length of time? To realize the difficulty of being head downwards, just do this, and get someone to hold your legs. The blood will, of course, "rush to the head", as we say, and the congestion of the blood-vessels in this part of the body will make you feel extremely dizzy. Such an occurrence would be fatal in an aeroplane nearly a mile high in the air at a time when one requires an especially clear brain to manipulate the various controls. But, strange to say, the airman gradually became used to the "heels-over-head" position, and, feeling sure of himself, he determined to start on his perilous undertaking. No one with the exception of M. Bleriot and the mechanics were present at the Buc aerodrome, near Versailles, when Mr. Hucks had his monoplane brought out with the intention of looping the loop. He quickly rose to a height of 1500 feet, and then, slowly dipping the nose of his machine, turned right over. For fully half a minute he flew underneath the monoplane, and then gradually brought it round to the normal position. In the afternoon he continued his experiments, but this time at a height of nearly 3000 feet. At this altitude he was flying quite steadily, when suddenly he assumed a perpendicular position, and made a dive of about 600 feet. The horrified spectators thought that the gallant aviator had lost control of his machine and was dashing straight to Earth, but quickly he changed his direction and slowly planed upwards. Then almost as suddenly he turned a complete somersault. Righting the aeroplane, he rose in a succession of spiral flights to a height of between 3000 and 3500 feet, and then looped the loop twice in quick succession. On coming to earth M. Bleriot heartily congratulated the brave Englishman. Mr. Hucks admitted a little nervousness before looping the loop; but, as he remarked: "Once I started to go round my nervousness vanished, and then I knew I was coming out on top. It is all a question of keeping control of your nerves, and Pegoud deserved all the credit, for he was the first to risk his life in flying head downwards." Mr. Hucks intended to be the first Englishman to fly upside down in England, but he was forestalled by one of our youngest airmen, Mr. George Lee Temple. On account of his youth--Mr. Temple was only twenty-one at the time when he first flew upside-down--he was known as the "baby airman", but there was probably no more plucky airman in the world. There were special difficulties which Mr. Temple had to overcome that did not exist in the experiments of M. Pegoud or Mr. Hucks. To start with, his machine--a 50-horse-power Bleriot monoplane--was said by the makers to be unsuitable for the performance. Then he could get no assistance from the big aeroplane firms, who sought to dissuade him from his hazardous undertaking. Experienced aviators wisely shook their heads and told the "baby airman" that he should have more practice before he took such a risk. But notwithstanding this lack of encouragement he practised hard for a few days by hanging in an inverted position. Meanwhile his mechanics were working night and day in strengthening the wings of the monoplane, and fitting it with a slightly larger elevator. On 24th November, 1913, he decided to "try his luck" at the London aerodrome. He was harnessed into his seat, and, bidding his friends farewell, with the words "wish me luck", he went aloft. For nearly half an hour he climbed upward, and swooped over the aerodrome in wide circles, while his friends far below were watching every action of his machine. Suddenly an alarming incident occurred. When about a mile high in the air the machine tipped downwards and rushed towards Earth at terrific speed. Then the tail of the machine came up, and the "baby airman" was hanging head downwards. But at this point the group of airmen standing in the aerodrome were filled with alarm, for it was quite evident to their experienced eyes that the monoplane was not under proper control. Indeed, it was actually side-slipping, and a terrible disaster appeared imminent. For hundreds of feet the young pilot, still hanging head downwards, was crashing to Earth, but when down to about 1200 feet from the ground the machine gradually came round, and Mr. Temple descended safely to Earth. The airman afterwards told his friends that for several seconds he could not get the machine to answer the controls, and for a time he was falling at a speed of 100 miles an hour. In ordinary circumstances he thought that a dive of 500 feet after the upside-down stretch should get him the right way up, but it really took him nearly 1500 feet. Fortunately, however, he commenced the dive at a great altitude, and so the distance side-slipped did not much matter. It is sad to relate that Mr. Temple lost his life in January, 1914, while flying at Hendon in a treacherous wind. The actual cause of the accident was never clearly understood. He had not fully recovered from an attack of influenza, and it was thought that he fainted and fell over the control lever while descending near one of the pylons, when the machine "turned turtle", and the pilot's neck was broken. CHAPTER XLV. Accidents and their Cause "Another airman killed!" "There'll soon be none of those flying fellows left!" "Far too risky a game!" "Ought to be stopped by law!" How many times have we heard these, and similar remarks, when the newspapers relate the account of some fatality in the air! People have come to think that flying is a terribly risky occupation, and that if one wishes to put an end to one's life one has only to go up in a flying machine. For the last twenty years some of our great writers have prophesied that the conquest of the air would be as costly in human life as was that of the sea, but their prophecies have most certainly been wrong, for in the wreck of one single vessel, such as that of the Titanic, more lives were lost than in all the disasters to any form of aerial craft. Perhaps some of our grandfathers can remember the dread with which many nervous people entered, or saw their friends enter, a train. Travellers by the railway eighty or ninety years ago considered that they took their lives in their hands, so to speak, when they went on a long journey, and a great sigh of relief arose in the members of their families when the news came that the journey was safely ended. In George Stephenson's days there was considerable opposition to the institution of the railway, simply on account of the number of accidents which it was anticipated would take place. Now we laugh at the fears of our great-grandparents; is it not probable that our grandchildren will laugh in a similar manner at our timidity over the aeroplane? In the case of all recent new inventions in methods of locomotion there has always been a feeling among certain people that the law ought to prohibit such inventions from being put into practice. There used to be bitter opposition to the motor-car, and at first every mechanically-driven vehicle had to have a man walking in front with a red flag. There are risks in all means of transit; indeed, it may be said that the world is a dangerous place to live in. It is true, too, that the demons of the air have taken their toll of life from the young, ambitious, and daring souls. Many of the fatal accidents have been due to defective work in some part of the machinery, some to want of that complete knowledge and control that only experience can give, some even to want of proper care on the part of the pilot. If a pilot takes ordinary care in controlling his machine, and if the mechanics who have built the machine have done their work thoroughly, flying, nowadays, should be practically as safe as motoring. The French Aero Club find, from a mass or information which has been compiled for them with great care, that for every 92,000 miles actually flown by aeroplane during the year 1912, only one fatal accident had occurred. This, too, in France, where some of the pilots have been notoriously reckless, and where far more airmen have been killed than in Britain. When we examine carefully the statistics dealing with fatal accidents in aeroplanes we find that the pioneers of flying, such as the famous Wright Brothers, Bleriot, Farman, Grahame-White, and so on, were comparatively free from accidents. No doubt, in some cases, defective machines or treacherous wind gusts caused the craft to collapse in mid-air. But, as a rule, the first men to fly were careful to see that every part of the machine was in order before going up in it, so that they rarely came to grief through the planes not being sufficiently tightened up, wires being unduly strained, spars snapping, or bolts becoming loose. Mr. Grahame-White admirably expresses this when he says: "It is a melancholy reflection, when one is going through the lists of aeroplane fatalities, to think how many might have been avoided. Really the crux of the situation in this connection, as it appears to me, is this: the first men who flew, having had all the drudgery and danger of pioneer work, were extremely careful in all they did; and this fact accounts for the comparatively large proportion of these very first airmen who have survived. "But the men who came next in the path of progress, having a machine ready-made, so to speak, and having nothing to do but to get into it and fly, did not, in many cases, exercise this saving grace of caution. And that--at least in my view--is why a good many of what one may call the second flight of pilots came to grief." CHAPTER XLVI. Accidents and their Cause (Cont.) One of the main causes of aeroplane accidents has been the breakage of some part of the machine while in the air, due to defective work in its construction. There is no doubt that air-craft are far more trustworthy now than they were two or three years ago. Builders have learned from the mistakes of their predecessors as well as profited by their own. After every serious accident there is an official enquiry as to the probable cause of the accident, and information of inestimable value has been obtained from such enquiries. The Royal Aero Club of Great Britain has a special "Accidents Investigation Committee" whose duty it is to issue a full report on every fatal accident which occurs to an aeroplane in this country. As a rule, representatives of the committee visit the scene of the accident as soon as possible after its occurrence. Eye-witnesses are called before them to give evidence of the disaster; the remains of the craft are carefully inspected in order to discover any flaw in its construction; evidence is taken as to the nature and velocity of the wind on the day of the accident, the approximate height at which the aviator was flying, and, in fact, everything of value that might bear on the cause of the accident. As a good example of an official report we may quote that issued by the Accidents Investigation Committee of the Royal Aero Club on the fatal accident which occurred to Colonel Cody and his passenger on 7th August, 1913. "The representatives of the Accidents Committee visited the scene of the accident within a few hours of its occurrence, and made a careful examination of the wrecked air-craft. Evidence was also taken from the eye-witnesses of the accident. "From the consideration of the evidence the Committee regards the following facts as clearly established: "1. The air-craft was built at Farnborough, by Mr. S. F. Cody, in July, 1913. "2. It was a new type, designed for the Daily Mail Hydroplane Race round Great Britain, but at the time of the accident had a land chassis instead of floats. "3. The wind at the time of the accident was about 10 miles per hour. "4. At about 200 feet from the ground the air-craft buckled up and fell to the ground. A large piece of the lower left wing, composing the whole of the front spar between the fuselage and the first upright, was picked up at least 100 yards from the spot where the air-craft struck the ground. "5. The fall of the air-craft was broken considerably by the trees, to such an extent that the portion of the fuselage surrounding the seats was practically undamaged. "6. Neither the pilot nor passenger was strapped in. "Opinion. The Committee is of opinion that the failure of the air-craft was due to inherent structural weakness. "Since that portion of the air-craft in which the pilot and passenger were seated was undamaged, it is conceivable their lives might have been saved had they been strapped in." This occasion was not the only time when the Accidents Investigation Committee recommended the advisability of the airman being strapped to his seat. But many airmen absolutely refuse to wear a belt, just as many cyclists cannot bear to have their feet made fast to the pedals of their cycles by using toe-clips. Mention of toe-clips brings us to other accidents which sometimes befall airmen. As we have seen in a previous chapter, Mr. Hawker's accident in Ireland was due to his foot slipping over the rudder bar of his machine. It is thought that the disaster to Mr. Pickles' machine on "Aerial Derby" day in 1913 was due to the same cause, and on one occasion Mr. Brock was in great danger through his foot slipping on the rudder bar while he was practising some evolutions at the London Aerodome. Machines are generally flying at a very fast rate, and if the pilot loses control of the machine when it is near the ground the chances are that the aeroplane crashes to earth before he can right it. Both Mr. Hawker and Mr. Pickles were flying low at the time of their accidents, and so their machines were smashed; fortunately Mr. Brock was comparatively high up in the air, and though his machine rocked about and banked in an ominous manner, yet he was able to gain control just in the nick of time. To prevent accidents of this kind the rudder bars could be fitted with pedals to which the pilot's feet could be secured by toe-clips, as on bicycle pedals. Indeed, some makers of air-craft have already provided pedals with toe-clips for the rudder bar. Probably some safety device such as this will soon be made compulsory on all machines. We have already remarked that certain pilots do not pay sufficient heed to the inspection of their machines before making a flight. The difference between pilots in this respect is interesting to observe. On the great day at Hendon, in 1913--the Aerial Derby day--there were over a dozen pilots out with their craft. From the enclosure one could watch the airmen and their mechanics as the machines were run out from the hangars on to the flying ground. One pilot walked beside his mechanics while they were running the machine to the starting place, and watched his craft with almost fatherly interest. Before climbing into his seat he would carefully inspect the spars, bolts, wires, controls, and so on; then he would adjust his helmet and fasten himself into his seat with a safety belt. "Surely with all that preliminary work he is ready to start," remarked one of the spectators standing by. But no! the engine must be run at varying speeds, while the mechanics hold back the machine. This operation alone took three or four minutes, and all that the pilot proposed to do was to circle the aerodrome two or three times. An onlooker asked a mechanic if there were anything wrong with that particular machine. "No!" was the reply; "but our governor's very faddy, you know!" And now for the other extreme! Three mechanics emerged from a hangar pushing a rather ungainly-looking biplane, which bumped over the uneven ground. The pilot was some distance behind, with cigarette in mouth, joking with two or three friends. When the machine was run out into the open ground he skipped quickly up to it, climbed into the seat, started the engine, waved a smiling "good-bye", and was off. For all he knew, that rather rough jolting of the craft while it was being removed from the hangar might have broken some wire on which the safety of his machine, and his life, depended. The excuse cannot be made that his mechanics had performed this all-important work of inspection, for their attention was centred on the daring "banking" evolutions of some audacious pilot in the aerodrome. Mr. C. G. Grey, the well-known writer on aviation matters, and the editor of The Aeroplane, says, with regard to the need of inspection of air-craft:-- "A pilot is simply asking for trouble if he does not go all over his machine himself at least once a day, and, if possible, every time he is starting for a flight. "One seldom hears, in these days, of a broken wheel or axle on a railway coach, yet at the chief stopping places on our railways a man goes round each train as it comes in, tapping the tires with a hammer to detect cracks, feeling the hubs to see if there is any sign of a hot box, and looking into the grease containers to see if there is a proper supply of lubricant. There ought to be a similar inspection of every aeroplane every time it touches the ground. The jar of even the best of landings may fracture a bolt holding a wire, so that when the machine goes up again the wire may fly back and break the propeller, or get tangled in the control wires, or a strut or socket may crack in landing, and many other things may happen which careful inspection would disclose before any harm could occur. Mechanics who inspected machines regularly would be able to go all over them in a few minutes, and no time would be wasted. As it is, at any aerodrome one sees a machine come down, the pilot and passenger (a fare or a pupil) climb out, the mechanics hang round and smoke cigarettes, unless they have to perform the arduous duties of filling up with petrol. In due course another passenger and a pilot climb in, a mechanic swings the propeller, and away they go quite happily. If anything casts loose they come down--and it is truly wonderful how many things can come loose or break in the air without anyone being killed. If some thing breaks in landing, and does not actually fall out of place, it is simply a matter of luck whether anyone happens to see it or not." This advice, coming from a man with such wide experience of the theory and practice of flying, should surely be heeded by all those who engage in deadly combat with the demons of the air. In the early days of aviation, pilots were unacquainted with the nature and method of approach of treacherous wind gusts; often when they were flying along in a steady, regular wind, one of these gusts would strike their craft on one side, and either overturn it or cause it to over-bank, so that it crashed to earth with a swift side-slip through the air. Happily the experience of those days, though purchased at the cost of many lives, has taught makers of air-craft to design their machines on more trustworthy lines. Pilots, too, have made a scientific study of air eddies, gusts, and so on, and the danger of flying in a strong or gusty wind is comparatively small. CHAPTER XLVII. Accidents and their Cause (Cont.) Many people still think that if the engine of an aeroplane should stop while the machine was in mid-air, a terrible disaster would happen. All petrol engines may be described as fickle in their behaviour, and so complicated is their structure that the best of them are given to stopping without any warning. Aeroplane engines are far superior in horse-power to those fitted to motorcars, and consequently their structure is more intricate. But if an airman's engine suddenly stopped there would be no reason whatever why he should tumble down head first and break his neck. Strange to say, too, the higher he was flying the safer he would be. All machines have what is called a GLIDING ANGLE. When the designer plans his machine he considers the distribution of the weight or the engine, pilot and passengers, of the petrol, aeronautical instruments, and planes, so that the aeroplane is built in such a manner that when the engine stops, and the nose of the machine is turned downwards, the aeroplane of its own accord takes up its gliding angle and glides to earth. Gliding angles vary in different machines. If the angle is one in twelve, this would mean that if the glide wave commenced at a height of 1 mile, and continued in a straight line, the pilot would come to earth 12 miles distant. We are all familiar with the gradients shown on railways. There we see displayed on short sign-posts such notices as "1 in 50", with the opposite arms of the post pointing upwards and downwards. This, of course, means that the slope of the railway at that particular place is 1 foot in a distance of 50 feet. One in twelve may be described as the natural gradient which the machine automatically makes when engine power is cut off. It will be evident why it is safer for a pilot to fly, say, at four or five thousand feet high than just over the tree-tops or the chimney-pots of towns. Suppose, for example, the machine has a gliding angle of one in twelve, and that when at an altitude of about a mile the engine should stop. We will assume that at the time of the stoppage the pilot is over a forest where it is quite impossible to land. Directly the engine stopped he would change the angle of the elevating plane, so that the aeroplane would naturally fall into its gliding angle. The craft would at once settle itself into a forward and slightly downward glide; and the airman, from his point of vantage, would be able to see the extent of the forest. We will assume that the aeroplane is gliding in a northerly direction, and that the country is almost as unfavourable for landing there as over the forest itself. In fact, we will imagine an extreme case, where the airman is over country quite unsuitable for landing except toward the south; that is, exactly opposite to the direction in which he starts to glide. Fortunately, there is no reason why he should not steer his machine right round in the air, even though the only power is that derived from the force of gravity. His descent would be in an immense slope, extending 10 or 12 miles from the place where the engine stopped working. He would therefore be able to choose a suitable landing-place and reach earth quite safely. But supposing the airman to be flying about a hundred yards above the forest-an occurrence not likely to happen with a skilled airman, who would probably take an altitude of nearly a mile. Almost before he could have time to alter his elevating plane, and certainly long before he could reach open ground, he would be on the tree-tops. It is thought that in the near future air-craft will be fitted with two or more motors, so that when one fails the other will keep the machine on its course. This has been found necessary in Zeppelin air-ships. In an early Zeppelin model, which was provided with one engine only, the insufficient power caused the pilot to descend on unfavourable ground, and his vessel was wrecked. More recent types of Zeppelins are fitted with three or four engines. Experiments have already been made with the dual-engine plant for aeroplanes, notably by Messrs. Short Brothers, of Rochester, and the tests have given every satisfaction. There is little doubt that if the large passenger aeroplane is made possible, and if parliamentary powers have to be obtained for the formation of companies for passenger traffic by aeroplane, it will be made compulsory to fit machines with two or more engines, driving three or four distinct propellers. One of the engines would possibly be of inferior power, and used only in cases of emergency. Still another cause of accident, which in some cases has proved fatal, is the taking of unnecessary risks when in the air. This has happened more in America and in France than in Great Britain. An airman may have performed a very difficult and daring feat at some flying exhibition and the papers belauded his courage. A rival airman, not wishing to be outdone in skill or courage, immediately tries either to repeat the performance or to perform an even more difficult evolution. The result may very well end in disaster, and FAMOUS AIRMAN KILLED is seen on most of the newspaper bills. The daring of some of our professional airmen is notorious. There is one particular pilot, whose name is frequently before us, whom I have in mind when writing this chapter. On several occasions I have seen him flying over densely-packed crowds, at a height of about two hundred feet or so. With out the slightest warning he would make a very sharp and almost vertical dive. The spectators, thinking that something very serious had happened, would scatter in all directions, only to see the pilot right his machine and jokingly wave his hand to them. One trembles to think what would have been the result if the machine had crashed to earth, as it might very easily have done. It is interesting to relate that the risks taken by this pilot, both with regard to the spectators and himself, formed the subject of comment, and, for the future, flying over the spectators' heads has been strictly forbidden. From 1909 to 1913 about 130 airmen lost their lives in Germany, France, America, and the British Isles, and of this number the British loss was between thirty and forty. Strange to say, nearly all the German fatalities have taken place in air-ships, which were for some years considered much safer than the heavier-than-air machine. CHAPTER XLVIII. Some Technical Terms used by Aviators Though this book cannot pretend to go deeply into the technical side of aviation, there are certain terms and expressions in everyday use by aviators that it is well to know and understand. First, as to the machines themselves. You are now able to distinguish a monoplane from a biplane, and you have been told the difference between a TRACTOR biplane and a PROPELLER biplane. In the former type the screw is in front of the pilot; in the latter it is to the rear of the pilot's seat. Reference has been previously made to the FUSELAGE, SKIDS, AILERONS, WARPING CONTROLS, ELEVATING PLANES, and RUDDER of the various forms of air-craft. We have also spoken of the GLIDING ANGLE of a machine. Frequently a pilot makes his machine dive at a much steeper gradient than is given by its natural gliding angle. When the fall is about one in six the glide is known as a VOL PLANE; if the descent is made almost vertically it is called a VOL PIQUE. In some cases a PANCAKE descent is made. This is caused by such a decrease of speed that the aeroplane, though still moving forward, begins to drop downwards. When the pilot finds that this is taking place, he points the nose of his machine at a much steeper angle, and so reaches his normal flying speed, and is able to effect a safe landing. If he were too near the earth he would not be able to make this sharp dive, and the probability is that the aeroplane would come down flat, with the possibility of a damaged chassis. It is considered faulty piloting to make a pancake descent where there is ample landing space; in certain restricted areas, however, it is quite necessary to land in this way. A far more dangerous occurrence is the SIDE-SLIP. Watch a pilot vol-planing to earth from a great height with his engine shut off. The propeller rotates in an irregular manner, sometimes stopping altogether. When this happens, the skilful pilot forces the nose of his machine down, and so regains his normal flying speed; but if he allowed the propeller to stop and at the same time his forward speed through the air to be considerably diminished, his machine would probably slip sideways through the air and crash to earth. In many cases side-slips have taken place at aerodromes when the pilot has been rounding a pylon with the nose of his machine pointing upwards. When a machine flies round a corner very quickly the pilot tilts it to one side. Such action as this is known as BANKING. This operation can be witnessed at any aerodrome when speed handicaps are taking place. Since upside-down flying came into vogue we have heard a great deal about NOSE DIVING. This is a headlong dive towards earth with the nose of the machine pointing vertically downwards. As a rule the pilot makes a sharp nose dive before he loops the loop. Sometimes an aeroplane enters a tract of air where there seems to be no supporting power for the planes; in short, there appears to be, as it were, a HOLE in the air. Scientifically there is no such thing as a hole in the air, but airmen are more concerned with practice than with theory, and they have, for their own purposes, designated this curious phenomenon an AIR POCKET. In the early days of aviation, when machines were far less stable and pilots more quickly lost control of their craft, the air pocket was greatly dreaded, but nowadays little notice is taken of it. A violent disturbance in the air is known as a REMOUS. This is somewhat similar to an eddy in a stream, and it has the effect of making the machine fly very unsteadily. Remous are probably caused by electrical disturbances of the atmosphere, which cause the air streams to meet and mingle, breaking up into filaments or banding rills of air. The wind--that is, air in motion--far from being of approximate uniformity, is, under most ordinary conditions, irregular almost beyond conception, and it is with such great irregularities in the force of the air streams that airmen have constantly to contend. CHAPTER XLIX. The Future in the Air Three years before the outbreak of the Great War, the Master-General of Ordnance, who was in charge of Aeronautics at the War Office, declared: "We are not yet convinced that either aeroplanes or air-ships will be of any utility in war". After four years of war, with its ceaseless struggle between the Allies and the Central Powers for supremacy in the air, such a statement makes us rub our eyes as though we had been dreaming. Seven years--and in its passage the air encircling the globe has become one gigantic battle area, the British Isles have lost the age-long security which the seas gave them, and to regain the old proud unassailable position must build a gigantic aerial fleet--as greatly superior to that of their neighbours as was, and is, the British Navy. Seven years--and the monoplane is on the scrap-heap; the Zeppelin has come as a giant destroyer--and gone, flying rather ridiculously before the onslaughts of its tiny foes. In a recent article the editor of The Aeroplane referred to the erstwhile terror of the air as follows: "The best of air-ships is at the mercy of a second-rate aeroplane". Enough to make Count Zeppelin turn in his grave! To-day in aerial warfare the air-ship is relegated to the task of observer. As the "Blimp", the kite-balloon, the coast patrol, it scouts and takes copious notes; but it leaves the fighting to a tiny, heavier-than-air machine armed with a Lewis gun, and destructive attacks to those big bomb-droppers, the British Handley Page, the German Gotha, the Italian Morane tri-plane. The war in the air has been fought with varying fortunes. But, looking back upon four years of war, we may say that, in spite of a slow start, we have managed to catch up our adversaries, and of late we have certainly dealt as hard knocks as we have received. A great spurt of aerial activity marked the opening of the year 1918. From all quarters of the globe came reports, moderate and almost bald in style, but between the lines of which the average man could read word-pictures of the skill, prowess, and ceaseless bravery of the men of the Royal Flying Corps and Royal Naval Air Service. Recently there have appeared two official publications (1), profusely illustrated with photographs, which give an excellent idea of the work and training of members of the two corps. Forewords have been contributed respectively by Lord Hugh Cecil and Sir Eric Geddes, First Lord of the Admiralty. These publications lift a curtain upon not only the activities of the two Corps, but the tremendous organization now demanded by war in the air. (1) The Work and Training of the Royal Flying Corps and The Work and Training of the Royal Naval Air Service. All this to-day. To-morrow the Handley Page and Gotha may be occupying their respective niches in the museum of aerial antiquities, and we may be all agog over the aerial passenger service to the United States of America. For truly, in the science of aviation a day is a generation, and three months an eon. When the coming of peace turns men's thoughts to the development of aeroplanes for commerce and pleasure voyages, no one can foretell what the future may bring forth. At the time of writing, air attacks are still being directed upon London. But the enemy find it more and more difficult to penetrate the barrage. Sometimes a solitary machine gets through. Frequently the whole squadron of raiding aeroplanes is turned back at the coast. As for the military advantage the Germans have derived, after nearly four years of attacks by air, it may be set down as practically nil. In raid after raid they missed their so-called objectives and succeeded only in killing noncombatants. Far different were the aim and scope of the British air offensives into Germany and into country occupied by German troops. Railway junctions, ammunition dumps, enemy billets, submarine bases, aerodromes--these were the targets for our airmen, who scored hits by the simple but dangerous plan of flying so low that misses were almost out of the question. "Make sure of your objective, even if you have to sit upon it." Thus is summed up, in popular parlance, the policy of the Royal Flying Corps and Royal Naval Air Service. And if justification were heeded of this strict limitation of aim, it will be found in the substantial military losses inflicted upon the enemy results which would never have been attained had our airmen dissipated their energies on non-military objectives for the purpose of inspiring terror in the civil population. 
21708	----	UP IN THE CLOUDS, BY R.M. BALLANTYNE. CHAPTER ONE. BALLOON VOYAGES. TREATS OF EARLY EFFORTS TO FLY, ETCETERA. It is man's nature to soar intellectually, and it seems to have been his ambition from earliest ages to soar physically. Every one in health knows, or at some period of life must have known, that upward bounding of the spirit which induces a longing for the possession of wings, that the material body might be wafted upwards into those blue realms of light, which are so attractive to the eye and imagination of poor creeping man that he has appropriately styled them the heavens. Man has envied the birds since the world began. Who has not watched, with something more than admiration, the easy gyrations of the sea-mew, and listened, with something more than delight, to the song of the soaring lark? To fly with the body as well as with the mind, is a wish so universal that the benignant Creator Himself seems to recognise it in that most attractive passage in Holy Writ, wherein it is said that believers shall "mount up with wings as eagles, they shall run and not be weary, they shall walk and not faint." Of course man has not reached the middle of the nineteenth century without making numerous attempts to fly bodily up to the skies. Fortunately, however, such ambitious efforts have seldom been made except by the intellectually enthusiastic. Prosaic man, except in the case of the Tower of Babel, has remained content to gaze upwards with longing desire, and only a few of our species in the course of centuries have possessed temerity enough to make the deliberate effort to ride upon the wings of the wind. Naturally, the first attempts were, like most beginnings, simple and imitative. The birds flew with wings, therefore man put on artificial wings and essayed to fly like the birds. It was not until many grievous disappointments and sad accidents had befallen him, that he unwillingly gave up wings in despair, and set to work to accomplish his ends by more cumbrous and complex machinery. Very early in the world's history, however, "flying machines" were made, some of which were doubtless intended by their honest inventors to carry men through the air, while others were mere shams, made by designing men, wherewith to impose upon the ignorant for wicked ends of their own; and some of these last were, no doubt, believed to be capable of the feats attributed to them. The credulity of the ancients is not to be wondered at when we reflect on the magical illusions which science enables us to produce at the present day--illusions so vivid and startling that it requires the most elaborate explanations by adepts and philosophers to convince some among their audiences that what they think they see is absolutely not real! No wonder that the men of old had firm faith in the existence of all kinds of flying machines and creatures. They believed that fiery dragons were created by infernal machination, which, although not what we may call natural creatures, were nevertheless supposed to rush impetuous through the sky, vomiting flames and scattering the seeds of pestilence far and wide. In those dark ages, writers even ventured to describe the method of imitating the composition of such terrific monsters! A number of large hollow reeds were to be bound together, then sheathed completely in skin, and smeared over with pitch and other inflammable matters. This light and bulky engine, when set on fire, launched during thick darkness from some cliff into the air, and borne along by the force of the wind, would undoubtedly carry conviction to the minds of the populace, whilst it would fill them with amazement and terror! Sometimes, however, those who attempted to practise on the credulity of their fellows were themselves appalled by the results of their contrivances. Such was the case so late as the year 1750, when a small Roman Catholic town in Swabia was almost entirely burnt to ashes by an unsuccessful experiment made by some of the lowest order of priests for the astonishment, if not the edification, of their flocks. An attempt was made by them to represent the effigy of Martin Luther, whom the monks believed to be in league with Satan, under the form of a winged serpent with a forked tail and hideous claws. Unfortunately Martin's effigy, when ignited, refused to fly, and, instead of doing what was required of it, fell against the chimney of a house to which it set fire. The flames spread furiously in every direction, and were not subdued until the town was nearly consumed. In the early part of the sixteenth century a very determined attempt at flying was made by an Italian who visited Scotland, and was patronised by James the Fourth. He gained the favour of that monarch by holding out to him hopes of replenishing his treasury by means of the "philosopher's stone." The wily Italian managed, by his plausible address, to obtain a position which replenished, to some degree, his own empty purse, having been collated by royal favour to the abbacy of Tungland, in Galloway. Being an ingenious fellow, and somewhat, apparently, of an enthusiast, he spent some of his leisure time in fashioning a pair of huge wings of various plumage, with which he actually undertook to fly through the air from the walls of Stirling Castle to France! That he believed himself to be capable of doing so seems probable, from the fact that he actually made the attempt, but fell to the ground with such violence as to break his leg. He was sharp-witted, however, for instead of retiring crest-fallen at his failure, he coolly accounted for the accident by saying, "My wings were composed of various feathers; among them were the feathers of dunghill fowls, and they, by a certain sympathy, were attracted to the dunghill; whereas, had my wings been composed of eagles' feathers alone, the same sympathy would have attracted them to the region of the air!" About a century later a poor monk, whose boldness and enterprise were more conspicuous than his prudence, attempted a similar feat. He provided himself with a gigantic pair of wings, constructed on a principle propounded by the rector of the grammar school of Tubingen, in 1617, and, leaping from the top of a high tower, fell to the ground, broke both his legs, and lost his life. It was long before men came to see and admit that in regard to this they were attempting to accomplish the impossible. There can be no doubt that it is absolutely impossible for man to fly by the simple power of his own muscles, applied to any sort of machinery whatever. This is not an open question. That man may yet contrive to raise himself in the air by means of steam or electricity, or some other motive power, remains to be seen. It does not seem probable, but no one can say authoritatively that it is impossible. It is demonstrable, however, that to rise, or even to remain suspended, in the air by means of machinery impelled by human force alone is a feat which is as much an impossibility as it is for a man, by the strength of his own legs, to leap thirty or forty times his own length,--a grasshopper can do that easily, and a bird can fly easily, but a man cannot, and never will be able to do so, because his peculiar conformation forbids it. This was first demonstrated by Borelli, an eminent Italian mathematician and philosopher, who lived in a fertile age of discovery, and was thoroughly acquainted with the true principles of mechanics and pneumatics. He showed, by accurate calculation, the prodigious force, which in birds must be exerted and maintained by the pectoral muscles, with which the all-wise Creator has supplied them, and, by applying the same principles to the structure of the human frame, he proved how extremely disproportionate was the strength of the corresponding muscles in man. In fact, the man who should attempt to fly like a bird would be guilty of greater folly and ignorant presumption than the little infant who should endeavour to perform the feats of a gladiator! It is well for man in all things to attain, if possible, to a knowledge of what certainly lies beyond his powers, for such knowledge prevents the waste and misdirection of energies, as well as saving from disappointment and other evil results. But many of those enthusiasts, who have attempted at various periods of the world's history to fly, did not fall into the error which we have attempted to point out. On the contrary, they went intelligently to work; their only aim being modestly to fly _somewhat_ after the manner of a bird, but they all failed; nevertheless one philosopher, of modern times, stoutly continued to assert the opinion that there is no impossibility in man being able to fly _apparently_, though not really, like a bird. He did not hold that man could ever fly as high, or as far, or as fast, or in any degree as easily, as a bird. All that he ventured to say was, that he might perhaps fly _somewhat like one_. As the plan of this philosopher is rather curious, we shall detail it. It is well known that balloons, filled with appropriate gas, will rise. Big balloons and little ones are equally uppish in their tendencies. It is also known that rotundity of form is not essential to the successful rising of a balloon. "Well, then," says this philosopher, "what is to prevent a man making two balloons, flattish, and in the form of wings, which, instead of flying away with him, as ordinary balloons would infallibly do, should be so proportioned to his size and weight as that they would not do more than raise him an inch or so off the ground, and so keep him stotting and bobbing lightly about, something like the bright thin india-rubber balls with which children are wont to play now-a-days? "Having attained this position of, so to speak, readiness to fly, there is nothing to prevent him from propelling himself gently along the surface of the ground by means of fans, or, if you choose, small flexible cloth wings attached to the hands and arms. The legs might also be brought into play a little. It is obvious, however, that such wings would require to be mounted only in calm weather, for a breeze of wind would infallibly sweep the flyer off the face of the earth! We would only observe, in conclusion, that, however ridiculous this method of flying may appear in your eyes, this at least may be said in its favour, that whereas all other plans that have been tried have signally failed, _this_ plan has never failed--never having been tried! We throw the idea before a discriminating public, in the hope that some aspiring enthusiast, with plenty of means and nerve, and no family to mourn his loss, may one day prove, to the confusion of the incredulous, that our plan is not a mere flight of imagination!" When men began to find that wings refused in any circumstances to waft them to the realms of ether, they set about inventing aerial machines in which to ascend through the clouds and navigate the skies. In the fourteenth century a glimmering of the true principles on which a balloon could be constructed was entertained by Albert of Saxony, a monk of the order of Saint Augustin, but he never carried his theories into practice. His opinion was that, since fire is more attenuated than air, and floats above the region of our atmosphere, all that was necessary would be to enclose a portion of such ethereal substance in a light hollow globe which would thus be raised to a certain height, and kept suspended in the sky, and that by introducing a portion of air into the globe it would be rendered heavier than before, and might thus be made to descend. This was in fact the statement of the principles on which fire-balloons were afterwards constructed and successfully sent up, excepting that air heated by fire, instead of fire itself, was used. Others who came after Albert of Saxony held the same theory, but they all failed to reduce it to practice, and most of these men coupled with their correct notions on the subject, the very erroneous idea that by means of masts, sails, and a rudder, a balloon might be made to sail through the air as a ship sails upon the sea. In this they seem to have confounded two things which are dissimilar, namely, a vessel driven through water, and a vessel floating in air. The fallacy here may be easily pointed out. A ship is driven through water by a body in motion, namely, wind, while its rudder is dragged through a body comparatively at rest, namely, water; hence the rudder slides against or is pushed against the water, and according as it is _turned_ to one side or the other, it is _pushed_ to one side or the other, the stern of the ship going along with it, and the bow, of course, making a corresponding motion in the opposite direction. Thus the ship is turned or "steered," but it is manifest that if the ship were at rest there would be no pushing of the rudder by the water--no steering. On the other hand, if, though the ship were in motion, the sea was also flowing at the _same rate_ with the wind, there would be no flowing of water past the ship, the rudder would not be acted on, and the vessel could not be steered. Now a balloon, carried by the wind, cannot be steered by a rudder, because it does not, like the ship, rest half in one medium which is in motion, and half in another medium which is at rest. There is no sliding of any substance past its side, no possibility therefore of pushing a rudder against anything. All floats along _with_ the wind. If, however, the balloon could be made to go _faster_ than the wind, then steering would at once become possible; but sails cannot accomplish this, because, although wind can drive a ship faster than water flows, wind cannot drive a substance faster than itself flows. The men of old did not, however, seem to take these points into consideration. It yet remains to be seen whether steam shall ever be successfully applied to aerial machines, but this may certainly be assumed in the meantime, that, until by some means a balloon is propelled _faster than the wind_ through the atmosphere, sails will be useless, and steering, or giving direction, impossible. It was believed, in those early times, when scientific knowledge was slender, that the dew which falls during the night is of celestial origin, shed by the stars, and drawn by the sun, in the heat of the day, back to its native skies. Many people even went the length of asserting that an egg, filled with the morning dew, would, as the day advanced, rise spontaneously into the air. Indeed one man, named Father Laurus, speaks of this as an observed fact, and gravely gives directions how it is to be accomplished. "Take," says he, "a goose's egg, and having filled it with dew gathered fresh in the morning, expose it to the sun during the hottest part of the day, and it will ascend and rest suspended for a few moments." Father Laurus must surely have omitted to add that a goose's brains in the head of the operator was an element essential to the success of the experiment! But this man, although very ignorant in regard to the nature of the substances, with which he wrought, had some quaint notions in his head. He thought, for instance, that if he were to cram the cavity of an artificial dove with highly condensed air, the imprisoned fluid would impel the machine in the same manner as wind impels a sail. If this should not be found to act effectively, he proposed to apply fire to it in some way or other, and, to prevent the machine from being spirited away altogether by that volatile element, asbestos, or some incombustible material, was to be used as a lining. To feed and support this fire steadily, he suggested a compound of butter, salts, and orpiment, lodged in metallic tubes, which, he imagined, would at the same time heighten the whole effect by emitting a variety of musical tones like an organ! Another man, still more sanguine than the lest in his aerial flights of fancy, proposed that an ascent should be attempted by the application of fire as in a rocket to an aerial machine. We are not, however, told that this daring spirit ever ventured to try thus to invade the sky. There can be no doubt that much ingenuity, as well as absurdity, has been displayed in the various suggestions that have been made from time to time, and occasionally carried into practice. One man went the length of describing a huge apparatus, consisting of very long tin pipes, in which air was to be compressed by the vehement action of fire below. In a boat suspended from the machine a man was to sit and direct the whole by the opening and shutting of valves. Another scheme, more ingenious but not less fallacious, was propounded in 1670 by Francis Lana, a Jesuit, for navigating the air. This plan was to make four copper balls of very large dimensions, yet so extremely thin that, after the air had been extracted, they should become, in a considerable degree, specifically lighter than the surrounding medium. Each of his copper balls was to be about 25 feet in diameter, with the thickness of only the 225th part of an inch, the metal weighing 365 pounds avoirdupois, while the weight of the air which it should contain would be about 670 pounds, leaving, after a vacuum had been formed, an excess of 305 pounds for the power of ascension. The four balls would therefore, it was thought, rise into the air with a combined force of 1220 pounds, which was deemed by Lana to be sufficient to transport a boat completely furnished with masts, sails, oars, and rudders, and carrying several passengers. The method by which the vacuum was to be obtained was by connecting each globe, fitted with a stop-cock, to a tube of at least thirty-five feet long; the whole being filled with water; when raised to the vertical position the water would run out, the stop-cocks would be closed at the proper time, and the vacuum secured. It does not seem to have entered the head of this philosopher that the weight of the surrounding atmosphere would crush and destroy his thin exhausted receivers, but he seems to have been alarmed at the idea of his supposed discovery being applied to improper uses, such as the passing of desperadoes over fortified cities, on which they might rain down fire and destruction from the clouds! Perhaps the grandest of all the fanciful ideas that have been promulgated on this subject was that of Galien, a Dominican friar, who proposed to collect the fine diffused air of the higher regions, where hail is formed, above the summit of the loftiest mountains, and to enclose it in a cubical bag of enormous dimensions--extending more than a mile every way! This vast machine was to be composed of the thickest and strongest sail-cloth, and was expected to be capable of transporting through the air a whole army with all their munitions of war! There were many other devices which men hit upon, some of which embraced a certain modicum of truth mixed with a large proportion of fallacy. Ignorance, more or less complete, as to the principles and powers with which they dealt, was, in days gone by, the cause of many of the errors and absurdities into which men were led in their efforts to mount the atmosphere. Our space, however, forbids further consideration of this subject, which is undoubtedly one of considerable interest, and encircled with a good deal of romance. Turning away from all those early and fanciful speculations, we now come to that period in the history of balloon voyaging, or aeronautics, when true theories began to be philosophically applied, and ascending into the skies became an accomplished fact. CHAPTER TWO. THE FIRST BALLOONS. The germ of the invention of the balloon lies in the discovery of Mr Cavendish, made in 1766, that hydrogen gas, called inflammable air, is at least seven times lighter than atmospheric air. Founding on this fact, Dr Black of Edinburgh proved by experiment that a very thin bag, filled with this gas, would rise to the ceiling of a room. In Dr Thomson's _History of Chemistry_, an anecdote, related by Mr Benjamin Bell, refers to this as follows:-- "Soon after the appearance of Mr Cavendish's paper on hydrogen gas, in which he made an approximation to the specific gravity of that body, showing that it was at least ten times lighter than common air, Dr Black invited a party of friends to supper, informing them that he had a curiosity to show them. Dr Hutton, Mr Clerk of Eldin, and Sir George Clerk of Penicuik, were of the number. When the company invited had arrived, he took them into a room where he had the allantois of a calf filled with hydrogen gas, and, upon setting it at liberty, it immediately ascended and adhered to the ceiling. The phenomenon was easily accounted for; it was taken for granted that a small black thread had been attached to the allantois, that the thread passed through the ceiling, and that some one in the apartment above, by pulling the thread, elevated it to the ceiling, and kept it in its position! This explanation was so plausible, that it was agreed to by the whole company, though, like many other plausible theories, it turned out wholly fallacious, for, when the allantois was brought down, no thread whatever was found attached to it. Dr Black explained the cause of the ascent to his admiring friends; but such was his carelessness of his own reputation, that he never gave the least account of this curious experiment even to his class, and several years elapsed before this obvious property of hydrogen gas was applied to the elevation of balloons." Cavallo made the first practical attempts with hydrogen gas six years later, but he only succeeded in causing soap-bubbles to ascend. At last the art of aerial navigation was discovered in France, and in 1782 the first ascent was made. The triumph was achieved by Stephen and Joseph Montgolfier, sons of a wealthy paper-maker who dwelt at Annonay, on the banks of a rivulet which flows into the Rhone, not far from Lyons. These brothers were remarkable men. Although bred in a remote provincial town, and without the benefit of a liberal education, they were possessed in a high degree of ingenuity and the spirit of observation. They educated themselves, and acquired an unusually large stock of information, which their inventive and original minds led them to apply in new fields of speculation. They were associated in business with their father, a man who passed his quiet days like a patriarch amidst a large family and a numerous body of dependants, until he reached the advanced age of ninety-three. Stephen devoted himself chiefly to the study of mathematics, Joseph to chemistry; and they were accustomed to form their plans in concert. It appears that they had long contemplated, with philosophical interest, the floating and ascent of clouds in the air, and when they heard of or read Cavendish's theories in regard to _different kinds of air_, it at once struck them that by enclosing some gas lighter than the atmosphere in a bag, a weight might be raised from the earth into the air. The brothers Montgolfier were men of that vigorous stamp who act promptly on receiving their convictions. At once they set about experimenting, and constructed large bags of paper,--the substance which naturally came readiest to their hands, and which appeared to them to be best suited to their purpose. These were filled with hydrogen gas, which raised them to the ceiling; but, owing to the escape of the gas through the pores and cracks of the case, those embryo balloons descended in a few minutes. Instead of varnishing the paper to prevent the escape of the gas, and supposing, erroneously, that the fault lay in the latter, they sought about for a new gas more suitable to the paper. This they found, as they supposed, in the gas which resulted from the combustion of wet straw and wool, which had an upward tendency, they thought, on account of its electrical properties, which caused it to be repelled from the ground. It is scarcely necessary now to point out that the true cause of the upward tendency lay in the rarefaction of the air by the heat of the fire, and that hot air has a tendency to rise because its bulk is greatly increased beyond the same quantity of the surrounding cold air. Although wrong in assigning the cause of the result, they were right in the application of it. While on a visit to Avignon Joseph Montgolfier procured a silk bag having a small opening at its lower end, and a capacity of about fifty cubic feet. Under the orifice some paper was burnt; the air inside was heated and expanded so as to fill the bag, which, when let go, soared rapidly up to the height of seventy or eighty feet, where it remained until the air cooled and allowed it to descend. Thus did the _first_ balloon ascend in the month of November 1782. Delighted with their success, the indefatigable brothers resolved to make further experiment on a larger scale. They procured a quantity of packcloth or coarse linen, formed it into a globe about ninety feet in circumference, lined it with paper, and lighted a fire under it in an iron choffer. This balloon went up with a force which they estimated as equivalent to 500 pounds. After this the Montgolfiers appeared to have become ambitious of accomplishing greater things, and giving to their discoveries publicity; for we are told that, "they invited the members of the provincial meeting of the states of the Vivarais, then assembled at Annonay, to witness the first _public_ aerial ascent. On the 5th June 1783, amidst a very large concourse of spectators, the spherical bag or balloon, consisting of different pieces of linen, merely buttoned together, was suspended from cross poles. Two men kindled a fire under it, and kept feeding the flame with small bundles of chopped straw. The loose bag gradually swelled, assuming a graceful form, and in the space of five minutes it was completely distended, and made such an effort to escape that eight men were required to hold it down. "On a signal being given the stays were slipped, and the balloon instantly rose with an accelerating motion till it reached some height, when its velocity continued uniform, and carried it to an elevation of more than a mile. All was admiration and transport. Amidst the shouts of unbounded applause, the progress of the artificial cloud retiring from sight arrested every eye. It was hurried along by the wind; but its buoyant force being soon spent, it remained suspended only ten minutes, and fell gently in a vineyard at a distance of about a mile and a half from the place of its ascension. So memorable a feat lighted up the glow of national vanity, and the two Montgolfiers were hailed and exalted by the spontaneous impulse of their fellow-citizens." This event created a sensation not only in France but over the whole of Europe. In Paris, particularly, the effect on all classes was so great that they determined to have the experiment repeated, set a subscription on foot, and appointed a scientific man named Charles, and two brothers of the name of Robert, to construct a balloon. This they did, but instead of applying the Montgolfier motive power--heated air--they used hydrogen gas, procured by the action of diluted sulphuric acid upon iron filings. Their balloon, which was made of thin silk, varnished with a solution of elastic gum, was a much nearer approach to the balloon of modern days than that of Montgolfier. It was a great success; it rose and remained suspended at a height of 100 feet, in which state it was conveyed with acclamation to the Place des Victoires, where it rested and underwent some repairs. At midnight it was conveyed in solemn procession by torchlight, and guarded by a detachment of horse, to the Champ de Mars, where, on the following day, the whole world of Paris turned out to witness another ascent. The balloon went up to the sound of cannon, and in two minutes reached a height of 3000 feet, when it was lost for a time in a dark cloud, but speedily reappeared still higher. After a flight of fifteen miles, performed in three-quarters of an hour, it sunk to the ground in a field near Ecouen, where it was secured by the peasants. The Parisians now appeared to become balloon-mad. The Royal Academy of Sciences invited Joseph Montgolfier to repeat his experiments, and another balloon was prepared by him of coarse linen with a paper lining, which, however, was destroyed by incessant and violent rain before it could be tried. Undeterred by this, another was constructed by him, which ascended from Versailles on the 19th of September 1783. This balloon deserves peculiar notice as being the first which carried up living creatures. A sheep, a cockerel, and a duck, were the first aeronauts! They ascended to a height of about 1500 feet; remained suspended for a time, and descended some two miles off in perfect safety--indeed we may say in perfect comfort, for the sheep was discovered to be quietly feeding when it returned to the earth! The practicability of ballooning being now fairly established, men soon began to venture their own persons in the frail cars. A young and enthusiastic naturalist named Rozier leaped into the car of another of Montgolfier's balloons soon after this, and ascended in safety to an elevation of about 300 feet, but on this occasion the balloon was held down by ropes. The ice, however, was broken, and bolder attempts quickly followed. CHAPTER THREE. EARLY ATTEMPTS AT AERIAL NAVIGATION. The first free and unfettered balloon voyage was performed very soon after the event mentioned at the end of the last chapter. It was a daring attempt, and attended with great danger. A balloon made by Montgolfier was used. It was 75 feet high, 45 feet wide, and spheroidal in form--heated air being the motive power. The bold aeronauts, on this occasion, were the naturalist Rozier and the Marquis d'Arlandes, a major of infantry. From the gardens of the Chateau of Muetta they ascended on the 21st November 1783. In the car there was a quantity of ballast, and a provision of straw to feed the fire. The balloon mounted at first with a majestic steady motion, gazed at in breathless wonder by thousands of spectators, who assembled not only in the neighbourhood of the Chateau, but clustered on every point of vantage in Paris. When the daring voyagers reached a considerable height, they took off their hats and waved them to their friends below, and the multitude-- realising, perhaps, that that which in former ages had been deemed the dream of visionaries, was at last an accomplished fact--responded with enthusiastic acclamations until the balloon passed upwards through the clouds and was lost to view. It would seem that these first aeronauts were of different temperaments; for, after they had reached a height of nearly 3000 feet, and the earth was no longer distinguishable, the Marquis began to think that he had seen enough of the upper regions, would fain have descended, and murmured against his companion, who still kept feeding the fire. Apparently his alarm was justifiable, for Rozier continued recklessly to heap on fuel, until he almost set the balloon on fire. On hearing some cracks from the top, and observing some holes burning in its sides, the Marquis became so alarmed that he compelled his companion to desist, and with wet sponges stopped the conflagration, which had actually begun. When the fire diminished, however, the balloon began to descend much quicker than was safe or agreeable, and the marquis himself began to throw fresh straw on the fire to enable them to clear the roofs of Paris. This they did very dexterously, considering that they were so unaccustomed to such navigation, throwing on just as much fuel as was sufficient for the purpose, and keeping clear of steeples and chimneys until they alighted in safety beyond the Boulevards. Their voyage lasted about half-an-hour, and they described a track of six miles around Paris, having ascended to a height of 3000 feet. Thus was the first balloon voyage successfully accomplished by the French; and the Montgolfiers, besides enjoying the triumph which their persevering efforts deserved, were awarded the annual prize--six hundred livres--of the Academy of Sciences. The elder brother was invited to Court, decorated with the badge of Saint Michael, and received a patent of nobility; while the younger received a pension and a sum of forty thousand livres wherewith to prosecute his experiments with balloons. The great success of the Montgolfier balloons naturally threw the efforts of Monsieur Charles and the brothers Robert into the shade. Nevertheless those gentlemen had got hold of a better principle than their rivals; and, knowing this, they resolved to convince the sceptical by constructing another balloon. They wisely began by obtaining subscriptions to enable them to carry out their designs, and finally succeeded in making a globe formed of tiffany, covered with elastic varnish, which was twenty-eight feet in diameter. This they filled with hydrogen gas. Some idea of their difficulties and expenses may be gathered from the fact that the mere filling of the balloon required an apparatus which cost about 400 pounds sterling, one-half of which was expended on the production of the gas alone. The ascent of this balloon deserves to be regarded with special interest, because, besides being the first _hydrogen_ balloon which carried up human beings, it was the first in which scientific observations were made and recorded. Monsieur Charles was a lecturer on natural philosophy, and, like our own great aeronaut, Mr Glaisher, does not seem to have been content to produce merely a spectacle, but went up to the realms of ether with an intelligent and scientific eye; for we read of him recording the indications of the thermometer and barometer at different heights and under various conditions. There were many accidents and delays in the construction of this balloon; but at last, on the 1st December 1783, it was taken to the Tuileries and there filled with gas. The process was slow, as the gas had to be generated in large quantities by means of diluted sulphuric acid and iron filings put into wooden casks disposed round a large cistern, from which it was conveyed through water in long leaden pipes. To keep the impatient populace quiet, therefore, during the tedious operation, Montgolfier sent up one of his fire-balloons. At last, when it was sufficiently filled, Messieurs Charles and Robert stepped into the car, which was ballasted with sandbags, and the ropes were let go. It went up with slow and solemn motion, at the rate of about five miles an hour. "The car," writes a reporter of the day in language more inflated than the balloon itself, "ascending amidst profound silence and admiration, allowed, in its soft and measured ascent, the bystanders to follow with their eyes and hearts two interesting men, who, like demigods, soared to the abode of the immortals, to receive the reward of intellectual progress, and carry the imperishable name of Montgolfier. After the globe had reached the height of 2000 feet, it was no longer possible to distinguish the aerial navigators; but the coloured pennants which they waved in the air testified their safety and their tranquil feelings. All fears were now dissipated; enthusiasm succeeded to astonishment; and every demonstration was given of joy and applause." The period of flight was an hour and three-quarters, which, for those early days of the art, was a pretty long voyage. By throwing over ballast the voyagers ascended, and by letting off gas they descended at pleasure; and they observed that during an hour, while they were exposed to the sun's rays, the gas was heated up to the temperature of fifty-five degrees of Fahrenheit's scale, which had the effect of sensibly increasing the buoyancy of the balloon. They descended safely on the meadow of Nesle, about twenty-five miles from Paris. But, not content with what he had accomplished, Monsieur Charles made a sudden resolve to have another flight alone. The shades of night were falling, and the sun had already set, when the enthusiastic aeronaut re-entered the car, and, casting off the grapnels, began his solitary night voyage. He was well rewarded. The balloon shot up with such celerity as to reach the height of about two miles in ten minutes, and the sun rose again to him in full orb! From his lofty station he watched it until it set again below the distant horizon. Probably Monsieur Charles was the first man in the world, on whom the sun thus rose and set twice in the same day! In such regions, at that romantic period of night, the aeronaut, as might have been expected, saw strange unearthly sights. Rising vapours concealed the lower world from view, and the moon shed her pale rays on accumulated masses of clouds, casting various hues over their fantastic and changing forms. No wonder that one thus surrounded by objects of awful grandeur and sublimity, left, as it were, more completely alone with God than any of his fellow-mortals, found it impossible to refrain from giving vent to his emotion in tears. Monsieur Charles did not remain long at this elevation. As the cold was excessive, and night advancing, he deemed it prudent to descend; opened the safety-valve, out of which the gas rushed like a misty vapour with a whistling noise, and, after the lapse of a little more than half an hour, alighted in safety near the wood of Tour du Lay, having travelled about nine miles. After this, balloon ascents became frequent. We cannot here give a particular account of each, even if it were desirable to do so, but, before passing to the consideration of the more recent voyages, we shall run over a few facts and incidents that occurred during the early period of aerial navigation. The first lady who went up in a balloon was a Madame Thible. She ascended from Lyons on 28th June 1784 with a Monsieur Fleurant in a fire-balloon. This lady of Lyons mounted to the extraordinary elevation of 13,500 feet--at least so it was estimated. The flagstaff, a pole of fourteen pounds weight, was thrown out and took seven minutes to reach the ground. The thermometer dropped to minus 43 degrees Fahrenheit, and the voyagers felt a ringing sensation in their ears. The first long voyage accomplished was about the same period, by a balloon constructed by Monsieur Robert, which was filled with hydrogen. It was 56 feet in height, and 36 in diameter. The Duke de Chartres ascended in it along with Robert and two others to a considerable height, and in five hours performed a voyage of 135 miles. This machine was furnished with a helm and four oars, for men still laboured under the erroneous belief that it was possible to direct the course of a balloon. One of the most interesting balloon voyages of the last century was that of Monsieur Testu. He ascended from Paris on the 18th June 1786 in a balloon of glazed tiffany, 29 feet in diameter, which was constructed by himself. It was filled with hydrogen, and had wings as well as oars! When the aeronaut deemed it advisable to descend, he attempted to do so by using the wings. These had little or no power, but the gradual waste of gas lowered him until he alighted safely in a corn field in the plain of Montmorency. Here he began to collect stones without quitting the car; but while thus engaged, was seized by the proprietor of the field with a troop of peasants, who demanded indemnification for the damage alleged to have been done by him. Poor Testu assured them that his wings being broken, he was at their mercy, whereupon the stupid and ill-natured boors seized the stay of the balloon, which floated some height above the ground, and dragged him in triumph towards their village. Their triumph, however, was short-lived. Finding that the loss of his wings and some other articles had lightened him considerably, he quietly cut the cord and bade the clowns an abrupt farewell! Testu then rose to the clouds, where he experienced the violence and witnessed the grandeur of a thunderstorm, the terrible nature of which was greatly increased when night closed in, while lightning flashed on all sides, thunder reverberated in the sky, and sleet fell copiously around him. On this voyage he saw some hunters in a field, and descended to observe them! He remained out all night, saw the sun set and rise, and finally alighted near the village of Campremi, about sixty-three miles from Paris. CHAPTER FOUR. THE FIRST AERIAL VOYAGES MADE IN GREAT BRITAIN--SUCCEEDING ASCENTS. The credit of the first aerial voyage made in Great Britain has usually been given to Vincenzo Lunardi, an Italian. There is ground for believing, however, that the first balloon voyage was performed by a Scotchman, as the following extract from Chamber's _Book of Days_ will show:-- "It is generally supposed that Lunardi was the first person who ascended by means of a balloon in Great Britain, but he certainly was not. A very poor man, named James Tytler, who then lived in Edinburgh, supporting himself and family in the humblest style of garret or cottage life by the exercise of his pen, had this honour. He had effected an ascent at Edinburgh on the 27th of August 1784, just nineteen days previous to Lunardi. Tytler's ascent, however, was almost a failure, by his employing the dangerous and unmanageable Montgolfier principle. After several ineffectual attempts, Tytler, finding that he could not carry up his fire-stove with him, determined, in the maddening desperation of disappointment, to go without this his sole sustaining power. Jumping into his car, which was no other than a common crate used for packing earthenware, he and the balloon ascended from Comely Garden, and immediately afterwards fell in the Restalrig Road. For a wonder, Tytler was uninjured; and though he did not reach a greater altitude than 300 feet, nor traverse a greater distance than half a mile, yet his name must ever be mentioned as that of the first Briton who ascended with a balloon, and the first man who ascended in Britain. "Tytler was the son of a clergyman of the Church of Scotland, and had been educated as a surgeon; but being of an eccentric and erratic genius, he adopted literature as a profession, and was the principal editor of the first edition of the _Encyclopaedia Britannica_. Becoming embroiled in politics, he published a handbill of a seditious tendency, and consequently was compelled to seek a refuge in America, where he died in 1805, after conducting a newspaper at Salem, in New England, for several years." The voyage of Vincenzo Lunardi was made in September 1784. His letters to a friend, in which he comments on the manners and customs of the English, are very amusing. His balloon was of the ordinary spherical shape, made of the best oiled silk, about 520 yards of which were used in its construction. It was filled with hydrogen gas, and provided with car, oars, and wings. The car consisted simply of a wooden platform surrounded by a breast high railing, and the oars and wings were intended, the one to check, by a vertical motion, the rapidity of descent, and the other to act as sails when becalmed in the upper regions of cloudland. He requested permission to make Chelsea Hospital the scene of his first aerial exploit, and the Governor, Sir George Howard, with the full approval of His Majesty King George the Third, gave his consent. He accordingly made all necessary arrangements for an ascent, and his fondest expectations seemed about to be realised. He was, however, doomed to disappointment, owing to the failure of a rival balloon. Writing to a friend at this time he says, "The events of this extraordinary island are as variable as its climate. It was but lately everything relating to my undertaking wore a favourable and pleasing appearance, but I am at this moment overwhelmed with anxiety, vexation, and despair." This rival balloon was constructed by a Frenchman named De Moret, who, having succeeded in attracting a concourse of fifty or sixty thousand people to see his ascent, failed in the primary part of his undertaking,--that of filling his balloon. The people, after waiting patiently for three hours, and supposing "the whole affair an imposture, rushed in and tore it to pieces." In consequence of this failure, and the riots with which it was followed, the Governor forbade Signor Lunardi to make his ascent from Chelsea Hospital grounds. He writes again to his friend, "The national prejudice of the English against France is supposed to have its full effect on a subject, from which the _literati_ of England expect to derive but little honour. An unsuccessful attempt has been made by a Frenchman, and my name being that of a foreigner, a very excusable ignorance in the people may place me among the adventurers of that nation, who are said to have sometimes distinguished themselves here by ingenious impositions." In vain did he try to obtain another place to launch his aerial ship; he was laughed at and ridiculed as an impostor, and the colleague of De Moret. At length, after much exertion, he obtained leave to ascend from the ground of the Honourable Artillery Company. By twelve o'clock on the day fixed for the ascension, an immense mass of people had assembled, including the Prince of Wales. The filling of the balloon caused some delay, but, in order to keep the patience of the populace within control, it was only partially filled. At five minutes past two the balloon ascended amid the loud acclamations of the assembled multitudes, and Signor Lunardi had proved himself no impostor. He writes to his friend, "The stillness, extent, and magnificence of the scene rendered it highly awful. My horizon seemed a perfect circle, the terminating line several hundred miles in circumference; this I conjectured from the view of London, the extreme points of which formed an angle only a few degrees. It was so reduced on the great scale before me that I can find no simile to convey an idea of it. I could distinguish Saint Paul's and other churches from the houses; I saw the streets as lines, all animated with beings whom I knew to be men and women, but which otherwise I should have had a difficulty in describing. It was an enormous bee-hive, but the industry of it was suspended. All the moving mass seemed to have no object but myself, and the transition from the suspicion, perhaps contempt, of the preceding hour, to the affectionate transport, admiration, and glory of the present moment, was not without its effect on my mind. It seemed as if I had left below all the cares and passions that molest mankind. I had not the slightest sense of motion in the machine; I knew not whether it went swiftly or slowly, whether it ascended or descended, whether it was agitated or tranquil, but by the appearance or disappearance of objects on the earth. The height had not the effect which a much less degree of it has near the earth, that of producing giddiness. The gradual diminution of objects, and the masses of light and shade, are intelligible in oblique and common prospects, but here everything wore a new appearance and had a new effect. The face of the country had a mild and permanent verdure, to which Italy is a stranger. The variety of cultivation and the accuracy with which property is divided give the idea, ever present to the stranger in England, of good civil laws and an equitable administration. The rivulets meandering; the immense districts beneath me spotted with cities, towns, villages, and houses, pouring out their inhabitants to hail my appearance. You will allow me some merit in not having been exceedingly intoxicated with my situation." He descended at North Mimms about half-past three-o'clock, but wishing to obtain a second triumph, he threw out the remainder of his ballast and provisions, landed a cat which he had taken up with him, and which had suffered severely from the cold, and again ascended to the regions above. This time his ascent was more rapid, the thermometer quickly fell to 29 degrees, and icicles were soon formed all round his machine. He descended at twenty minutes past four near Ware in Hertfordshire, and the balloon being properly secured, the gas was let out and "nearly poisoned the whole neighbourhood by the disagreeable stench emitted." The success and triumph of this first attempt in aerial navigation in English air exceeded Signor Lunardi's utmost expectations. Everywhere he was received with marks of approbation, and treated as a hero. "My fame," he writes, "has not been sparingly diffused by the newspapers (which in England are the barometers of public opinion; often erroneous, as other instruments are, in their particular information, but yielding the best that can be obtained). You will imagine the importance of these vehicles of knowledge when you learn that in London alone there are printed no less than 160,000 papers weekly, which, by a stamp on each paper, and a duty on advertisements, brings into the treasury of the nation upwards of 80,000 pounds a year. They are to the English constitution what the Censors were to those of ancient Rome. Ministers of State are checked and kept in awe by them, and they freely, and often judiciously, expose the pretensions of those who would harass Government merely to be taken into its service." There were many other aeronauts who distinguished themselves after this period. In 1785, Monsieur Blanchard, with Dr J. Jeffries, an American, crossed the channel between England and France in a balloon--starting from Dover, and descending in safety in the Forest of Guiennes. They had, however, a narrow escape, having been compelled to throw out all their ballast, and everything they could dispense with, to prevent their balloon from falling into the sea. The first ascents for scientific purposes were made about the beginning of the present century. In 1803, Mr Robertson ascended from Saint Petersburg, for the purpose of making electrical, magnetical, and physiological experiments. Messieurs Gay-Lussac and Biot followed his example from Paris, in 1804. Gay-Lussac was an enthusiastic and celebrated aeronaut. He made several interesting ascents. Two years afterwards, Brioschi, the Astronomer-Royal at Naples, endeavoured to ascend to a higher elevation than had been reached by Monsieur Gay-Lussac--namely, 22,977 feet. He was accompanied by Signor Andreani, the first Italian aeronaut. The balloon burst when at a great height, but the remnants were sufficient to check the descent so much that both gentlemen escaped with their lives. Brioschi, however, received injuries which afterwards resulted in his death. In England one of the most famous aeronauts was Mr Green, who introduced coal gas for balloons, and made many hundreds of ascents. In the year 1836 he ascended from London in a coal-gas balloon, and with two other gentlemen made an aerial voyage to Weilburg in the grand Duchy of Nassau. It lasted eighteen hours, and extended over 500 miles. CHAPTER FIVE. PARACHUTES. Of the other voyages which were made in balloons in our own country and in foreign lands about this period we shall say nothing, but, before describing the most interesting of recent ascents, give a short account of the parachute. This contrivance has been considered by some a very important adjunct to the balloon; whether it be so or no, we do not pretend to determine, but certainly it is an interesting and curious machine, which merits notice. The parachute may be described as a species of gigantic umbrella attached to the balloon below the car, which hangs in a loose form while ascending, but expands, of necessity, when cut adrift and allowed to descend. As the balloon has a car hung beneath it, so in like manner the parachute has a small car or basket, capable of holding one person, suspended from it. The word signifies a _guard against falling_--from the French _parer_, to ward off, and _chute_, a fall, and is allied to _parasol_, which means literally "a warder off of the sun." The parachute was introduced some years after a terrible accident which occurred to the celebrated aeronaut Rozier, who, desirous of emulating Blanchard and Jeffries by crossing the channel from France to England in a balloon, made an attempt, which cost him his life. Rozier's balloon was about forty feet in diameter, and had attached to it, beneath, a smaller balloon on the Montgolfier principle. On the 15th of June 1785, he entered the car with Monsieur Romain, and ascended to the height of above three thousand feet, when it was observed by the spectators that the lower balloon had caught fire. With horror they saw that the fire spread--the whole apparatus was in a blaze--and in another minute it descended like a shattered meteor to the ground with a terrible crash. It fell near the sea-shore, about four miles from Boulogne, and of course the unfortunate voyagers were killed instantaneously. At a later period a Venetian nobleman and his lady fell with their balloon from a great height and were killed. It must be remarked, however, that cases of this kind were very rare, considering the rage which there was at that period for ballooning. In order to provide aeronauts with a means of escape--a last resource in case of accident--the parachute was invented. It may be regarded as a balloon's lifeboat, which will (perhaps!) bear the passengers in safety to the ground in case of balloon-wreck. Doubtless the umbrella suggested the parachute. Every one knows the tremendous force that this implement exerts in a high wind if the unfortunate owner should happen to get turned round in the wrong direction. The men of the east have, it is said, turned this power to account by making use of an umbrella to enable them to leap from considerable heights. In particular, a native of Siam, who was noted for his feats of agility, was wont to amuse the King and his court by taking tremendous leaps, having two small umbrellas with long slender handles attached to his girdle. These eased him down in safety, but he was occasionally driven by the wind against trees or houses, and sometimes into a neighbouring river. In case any adventurous individual should be tempted to make trial of the powers of himself and his umbrella in this way, we think it right, by way of caution, to tell him that the French General Bournonville, who was imprisoned in the fortress of Olmutz in 1793, became so desperate that he attempted to regain his freedom by leaping with an umbrella from his window, which was forty feet from the ground. He hoped that the umbrella would break his fall. Doubtless it did so to some extent, and saved him from being killed, but being a large heavy man, he came down with sufficient violence to break his leg, and was carried back to his dungeon. The chief differences between a parachute and an umbrella lie in the great size of the former, and in the cords which stretch from the outer points of its ribs to the lower end of the handle. These cords give it strength, and prevent it from turning inside out. There is also a hole in the top of the parachute to allow some of the air to escape. The first parachute was constructed by Blanchard in 1785, and a dog was the first living creature that descended in it, and reached the earth unhurt. Blanchard afterwards made a descent in person at Basle, and broke his leg in the fall. The bold aeronaut Monsieur Garnerin next ventured to make the perilous descent. He visited London in 1802, and made several ascents in a balloon. During one of these, on the evening of the 2nd November, he cut himself adrift in his parachute when at a vast height. The parachute was made of white canvas, having thirty-two gores, which, when not in use, hung with its cords from a hoop near the top of the machine. When expanded, it formed a vast umbrella of twenty-three feet in diameter, with a small basket about four feet high, and two and a quarter wide, suspended below it. Monsieur Garnerin stood in this basket when his balloon mounted into the air from an enclosure near North Audley Street. The parachute hung like a curtain over his head, above it towered the balloon, beneath stood the anxious multitude. Well might they gaze in breathless expectation! After floating for some time in the upper regions of the air, as if he dreaded to make the bold attempt, he cut the cord that fastened him to the balloon when at the height, probably, of about half a mile. At first the parachute remained closed and descended with frightful violence; then it burst open, and for some seconds tossed about to such an extent that the basket was sometimes thrown almost into a horizontal position. The wind carried it over Marylebone and Somerstown; it almost grazed some of the houses of Saint Pancras in passing, and finally came to the ground in a field with such violence that poor Garnerin was thrown on his face and severely cut and bruised. No wonder that we are told he received a terrible shock. He trembled violently, and blood flowed from his nose and ears. Nevertheless, the accident did not deter his daughter from afterwards making the descent several times--and in safety. The cause of the irregularity and violence of Garnerin's descent was the giving way of one of the stays, which had the effect of deranging the balance of the apparatus. In 1837 Mr Cocking invented a new parachute, which he hoped would be free from the faults of the other. It may be described as being the reverse of that of Garnerin, being made in the form of an umbrella blown inside out. The resistance to the air, it was thought, would be sufficient to check the rapid descent, while its form would prevent the tendency to oscillate. This parachute was 34 feet in diameter, and was distended by a strong hoop to prevent its closing. There was also a hole in the middle of it, about 6 feet in diameter. Mr Cocking started from Vauxhall Gardens on the 24th of July, and after ascending to a considerable height, cut himself loose from his balloon when over Blackheath. The parachute descended rapidly, and vibrated with great violence; the large hoop broke, the machine collapsed, and the unfortunate aeronaut was killed, and his body dreadfully mutilated. Fatal accidents of this kind were to be expected; nevertheless it is a fact that the disasters which have befallen aeronauts have been comparatively few, considering the extreme danger to which they are necessarily exposed, not only from the delicacy of the materials, with which they operate, and the uncertainty of the medium through which they move, but, particularly, because of the impossibility of giving direction to their air-ships, or to arrest their progress through space. Parachutes, however, are not so absolutely incapable of being directed as are balloons. Monsieur Nadar writes on this point as follows:-- "Let us consider the action of the parachute. "A parachute is a sort of umbrella, in which the handle is replaced at its point of insertion by an opening intended to ease the excess of air, in order to avoid the strong oscillations, chiefly at the moment at which it is first expanded. Cords, departing symmetrically from divers points of the circumference, meet concentrically at the basket in which is the aeronaut. Above this basket, and at the entrance of the folded parachute, that is to say, closed during the rise, a hoop of sufficient diameter is intended to facilitate, at the moment of the fall, the entrance of the air which, rushing in under the pressure, expands the folds more easily and rapidly. "Now the parachute, where the weight of the car, of the attaching cords, and the wrigglings of the aeronaut, is in equilibrium with the expansion--the parachute, which seems to have no other aim but to moderate the shock in falling--the parachute even has been found capable of being directed, and aeronauts who have practised it, take care not to forget it. If the current is about to drive the aeronaut over a place where the descent is dangerous--say a river, a town, or a forest--the aeronaut perceiving to his right, let us suppose, a piece of ground suitable for his purpose, pulls at the cords which surround the right side, and by thus imparting a greater obliquity to his roof of silk, glides through the air, which it cleaves obliquely, towards the desired spot. Every descent, in fact, is determined by the side on which the incline is greatest." That these are not mere theoretical opinions or conjectures is certain from the fact that Mademoiselle Garnerin once wagered to guide herself with a parachute from the point of separation from her balloon to a place determined and very remote. By the combined inclinations which could be given to her parachute, she was seen in fact, very distinctly, to manoeuvre and tend towards the appointed place, and succeeded at length in alighting within a few yards of it. CHAPTER SIX. ASCENTS BY MESSRS. GLAISHER AND COXWELL. We now come to that point in our subject where it is appropriate to give more detailed and graphic accounts of the recent doings of aeronauts. An extremely interesting description of a scientific balloon ascent is given by the celebrated aeronaut, Mr Glaisher, in a pamphlet, from which we shall make a few extracts. [See Note 1.] His description is illustrative of the subject of ballooning, and contains the salient points of several ascents. He asks us to imagine the balloon somewhat more than half inflated, eager for flight, with only one link connecting it with earth, namely, a rope attached to an instrument, called a liberating iron catch. When all the ballast, instruments, etcetera, were placed in the car, Mr Coxwell brought the balloon to a _nice_ and _even_ balance, so that the addition of twenty pounds would have prevented it from rising. As the moment for departure drew near, friends became impatient, and every one anxiously watched the final arrangements, which were made by Mr Coxwell, on whom was laid the important duty of _letting go_. His hand was on the catch, his countenance was fixed, and his expression stern, as he gazed up into the heavens. He was waiting for the right moment, for the sky was partially cloudy, and it was necessary to wait until the balloon was midway between the cloud that had just passed and the next that was approaching, so that the aeronauts might have a clear sky, and be able to see the earth they were about to quit for a time. Nor was this all; he knew that in every wind, however strong it might be, there are periods of calm. If he could start in one of these he would avoid much rotatory motion. The deciding, therefore, of the exact moment for making a fair start was not so easy a matter as one might suppose. Some one at this critical time, with the characteristic eagerness of poor human nature to "put its finger in the pie," cried out "Now!" and another shouted "Pull!" but Mr Coxwell, regardless of every one, decided for himself; and, just when the wind lulled and the sun shone bright, and the balloon stood proudly erect, he pulled the trigger and they were free. But they were more than free. They were suddenly in profound repose, for--however high the wind may be, however agitated the balloon, swaying to and fro with sudden and violent action, despite the efforts of many hands that endeavour to restrain it,--no sooner do aeronauts quit their hold of earth, than, in an instant, all agitation ceases and they are in perfect stillness, without any sense of motion whatever; and this freedom continues throughout the entire flight--except, indeed, when they sink so low as to come into contact with mother earth, when the serenity of their flight is terribly and violently interrupted, as shall be seen in the case of another balloon voyage hereafter to be described. They were now fairly away, but we pause to remark, before joining them in their voyage, that their object on this occasion was not merely amusement--scientific investigation and experiment were their aim. In order that the reader may have some idea of the nature of such, we subjoin Mr Glaisher's list of the objects of his experiments: The primary objects were, he says, "to determine, at various heights, up to five miles--first, the pressure of the atmosphere; _second_, the temperature of the air; _third_, the hygrometrical (or moist-measured) states of the air." The secondary objects were: "To compare the readings of an aneroid barometer with those of a mercurial barometer, up to five miles. "To determine the electrical state of the air. "To determine the oxygenic state of the atmosphere by means of ozone papers. "To determine the time of vibration of a magnet on the earth, and at different distances from it. "To determine the temperature of the dew point by Daniell's dew point hygrometer and Regnault's condensing hygrometer, and by the use of the dry and wet bulb thermometers, as ordinarily used, and their use when under the influence of the aspirator, causing considerable volumes of air to pass over both their bulbs, at different elevations, as high as possible, but particularly up to heights where man may be resident, or where troops may be located, as in the high table-lands and plains of India; with the view of ascertaining what confidence may be placed in the use of the dry and wet bulb thermometers at those elevations, by comparison with Daniell's and Regnault's hygrometers; and also to compare the results as found by the two hygrometers together. "To collect air at different elevations. "To note the height and kind of clouds, their density and thickness at different elevations. "To determine the rate and direction of different currents in the atmosphere if possible. "To make observations on sound. "To note atmospherical phenomena in general, and to make general observations." With these objects in view the aeronauts left _terra firma_ and soared into the skies. "Once away," says Mr Glaisher, "we are both immediately at work; we have no time for graceful acknowledgments to cheering friends. Mr Coxwell must put the car in order, and accordingly looks to it, to his balloon, and to the course we are taking; and I must get my instruments in order, and without delay place them in their situations, adjust them, and take a reading as soon as possible. "In a few minutes we are from 1000 to 2000 feet high. Mr Coxwell looks intently upwards to see how the huge folds of the balloon fill into the netting. If we have started from a town, we now hear its busy hum, and the now fast fading cheers of our assembled friends naturally attract our attention. We behold at a glance the quickly-diminishing forms of the objects which we so lately left, and then resume our work. "Presently Mr Coxwell, who is always alive to the beauties of the ever-varying scene below, and to the opening landscape, fixes his eye upon me, and, just when a rural scene of surpassing beauty is lighted up in the west, he summons me to look and admire. I struggle against picturesque temptations, somewhat at variance with my duties, but cannot so quickly suppress them. A fine cloud rears its Alpine cap in close proximity to the car; Mr Coxwell looks as delighted as an artist when he displays a magnificent painting. I feel I must conquer such enchantment, and exclaim, `Beautiful! grand indeed!' and again resume my observations, with a cold philosophic resolve to pursue my readings without further interruption. "For a while I am quiet, the instruments affording indication that we are rising rapidly. Mr Coxwell again disturbs me just as we are approaching the clouds, and recommends a farewell peep at mother earth; and just as I take this, the clouds receive us, at first in a light gauze of vapour, and then in their chilly embrace, where I examine their structure, and note the temperature of the dew point particularly. "Shortly it becomes lighter, the light gradually increasing, till it is succeeded by a flood of light, at first striking, then dazzling, and we pass out of the dense cloud to where the clouds open out in bold and fantastic shapes, showing us light and shadow, and spectral scenes, with prismatic embellishments, disporting themselves around us in wild grandeur, till at length we break out into brilliant sunshine, and the clouds roll away in a perfect sea of vapour, obscuring the earth entirely; so that now in perfect silence I note the circumstances, and make my observations for some time uninterruptedly. "After a time Mr Coxwell directs my attention to the fact that the balloon is full, and that the gas is coming out from the safety-valve. I of course look, for this is an exciting moment. He then directs my attention to the fit and proportions of the netting. I find the gas, which was before cloudy and opaque, is now clear and transparent, so that I can look right up the balloon and see the meshes of the net-work showing through it, the upper valve with its springs and line reaching to the car, and the geometrical form of the balloon itself. Nor is this an idle examination. I have already said that, in passing through the cloud, the netting would gather moisture, augmenting the weight of the balloon. If this should not all have evaporated, the net-work would have become frozen, and be a wire-rope; so that, if the diamond shape of the netting when under tension, and the form of the crown of the balloon, be not symmetrical, the weight might not be equally distributed, and there would be danger of it cutting the balloon. A sense of security therefore follows such an examination. "A stream of gas now continually issues from the neck, which is very capacious, being fully two square feet in area, which is always left open. Presently I see Mr Coxwell, whose eye has been continually watching the balloon, pass his fingers over the valve-line, as if in readiness to pull the cord. I observe a slight gathering on his brow, and look inquiringly at him. He says, `I have decided upon opening the large upper valve,' and carefully explains why. `The tension,' he says, `in the balloon is not greater than it would bear with safety in a warm stratum of air; but now that we are three miles up with a chilled balloon, it is better to allow some to escape at top, as well as a good deal from the neck.' At once I see the force of the argument, and inwardly infer that I am in no way dependent upon chance, and not likely to suffer from carelessness with Mr Coxwell. We are now far beyond all ordinary sounds from the earth; a sea of clouds is below us, so dense that it is difficult to persuade ourselves that we have passed through them. Up to this time little or no inconvenience is met with; but on passing above four miles, much personal discomfort is experienced; respiration becomes difficult; the beating of the heart at times is audible; the hands and lips become blue, and at higher elevations the face also; and it requires the exercise of a strong will to make and record observations. Before getting to our highest point, Mr Coxwell counts the number of his sandbags, and calculates how much higher we can go, with respect to the reserve of ballast necessary to regulate the descent. "Then I feel a vibration in the car, and, on turning round, see Mr Coxwell in the act of lowering down the grapnel, then looking up at the balloon, then scanning the horizon, and weighing apparently in his mind some distant clouds through which we are likely to pass in going down. "A glance suffices to show that his mind is made up how much higher it is prudent to rise, and how much ballast it is expedient to preserve. "The balloon is now lingering, as it were, under the deep blue vault of space, hesitating whether to mount higher or begin its descent without further warning. We now hold a consultation, and then look around from the highest point, giving silent scope to those emotions of the soul which are naturally called forth by such a wide-spread range of creation. "Our course is now about to change. But here I interpose with `No, no; stop; not yet; let us remain so long that the instruments are certain to take up the true temperature, and that no doubt can rest upon the observations here. When I am satisfied I shall say, "Pull."' "Then in silence--for here we respire with difficulty, and talk but little--in the centre of this immense space, in solitude, without a single object to interrupt the view for 200 miles or more all round, abstracted from the earth, upheld by an invisible medium, our mouths so dry that we cannot eat, a white sea below us, so far below, we see few, if any, irregularities. I watch the instruments; but, forcibly impelled, again look round from the centre of this vacuity, whose boundary-line is 1500 miles, commanding nearly 130,000 square miles, till I catch Mr Coxwell's eye turned towards me, when I again direct mine to the instruments; and when I find no further changes are proceeding, I wave my hand and say, `Pull.' "A deep resonant sound is heard overhead; a second pull is followed by a second report, that rings as with shrill accompaniment down the very sides of the balloon. It is the working of the valve, which causes a loud booming noise, as from a sounding-board, as the springs force the shutters back. "But this sound in that solitary region, amid silence so profound that no silence on earth is equal to it,--a drum-like sound meeting the ear from above, from whence we do not usually hear sounds--strikes one forcibly. It is, however, one sound only; there is no reverberation, no reflection; and this is characteristic of all sounds in the balloon,-- one clear sound continuing during its vibrations, then gone in a moment. No sound ever reaches the ear a second time. But though the sound from the closing of the valve in those silent regions is striking, it is also cheering,--it is reassuring; it proves all to be right, that the balloon is sound, that the colder regions have not frozen tight the outlet for gas, and that we are so far safe. We have descended a mile, and our feelings improve with the increase of air and warmth. But silence reigns supreme, and Mr Coxwell, I observe, turns his back upon me, scanning intently the cloudscape, speculating as to when and where we shall break through and catch sight of the earth. We have been now two hours without seeing _terra firma_. How striking and impressive is it to realise a position such as this; and yet as men of action, whose province it is to subordinate mere feelings, we refrain from indulging in sentiment. I say refrain, for presently Mr Coxwell breaks out, no longer able to contain himself: `Here, Mr Glaisher, you must welcome another balloon. It is the counterpart of our own.' This spectral balloon is charming to look upon, and presents itself under a variety of imposing aspects, which are magnified or diminished by the relative distance of our balloon from the clouds, and by its position in relation to the sun, which produces the shadow. At mid-day it is deep down, almost underneath; but it is more grandly defined towards evening, when the golden and ruby tints of the declining sun impart a gorgeous colouring to cloudland. You may then see the spectre balloon magnified upon the distant cloud-tops, with three beautiful circles of rainbow tints. Language fails utterly to describe these illuminated photographs, which spring up with matchless truthfulness and choice decoration. "Just before we enter the clouds, Mr Coxwell, having made all preparations for the descent, strictly enjoins me to be ready to put up the instruments, lest, when we lose the powerful rays of the sun, and absorb the moisture of the lower clouds, we should approach the earth with too great rapidity. "We now near the confines of the clouds, and dip swiftly into the thickest of them; we experience a decided chill, and hear the rustling of the collapsing balloon, which is now but one-third full, but cannot see it, so dense is the mass of vapour. One, two, three, or more minutes pass, and we are still in the cloud. How thick it must be, considering the rapidity of the descent! Presently we pass below, and the earth is visible. There is a high road intersecting green pastures; a piece of water looking like polished steel presents itself; a farmhouse, with stacks and cattle, is directly under us. We see the sea-coast, but at a distance. An open country lies before us. A shout comes up, and announces that we are seen, and all goes well, save the rapidity of our descent, which has been caused by that dark frowning cloud which shut us out from the sun's rays, and bedewed us with moisture. Mr Coxwell, however, is counteracting it by means of the ballast, and streams out one bag, which appears to fly up instead of falling down; now another is cast forth, but still it goes up, up. A third reduces the wayward balloon within the bounds of moderation, and Mr Coxwell exultingly exclaims that `he has it now under perfect command, with sand enough, and to spare.' "Delighted to find the balloon is thus checked, as it is favourable to good readings of the several instruments at this elevation, I work as quickly as I can, noticing also the landscape below; rich mounds of green foliage, fields of various shades of green, like a tessellated pavement in motion; with roads, rivers, rivulets, and the undulatory nature of the ground varying the scene every instant. Should our passage be over a town, it is like a model in motion; and all is seen with a distinctness superior to that from the earth; the line of sight is through a purer and less dense medium; everything seems clearer, though smaller; even at the height of four miles above Birmingham we distinguished the New Street Station and the streets. "We have been descending slowly for a little time, when I am challenged to signify when I can close my observations, as yonder, about two miles distant, is a fine park, where Mr Coxwell's eye seems to wander with something like a desire to enter it. I approve of the spot, as it is in every way suitable for a descent. The under-current, which is oftentimes stronger than the upper, is wafting us merrily in that direction. We are now only a few hundred feet above the surface. `Put up your instruments,' cries Mr Coxwell, `and we will keep on this level until you are ready.' "A little more sand is let out, and I pack up the instruments quickly in their wadded cases. `Are you all right?' inquires the aeronaut. `All right,' I respond; `look out then, and hold fast by the ropes, as the grapnel will stop us in that large meadow, with the hedgerow in front.' "There, sure enough, we land. The cattle stand at bay affrighted, their tails are horizontal, and they run wildly away. But a group of friends from among the gentry and villagers draws up near the balloon, and although some few question whether we belong to this planet, or whether we are just imported from another, yet any doubt upon this point is soon set at rest, and we are greeted with a hearty welcome from all when we tell our story, how we travelled the realms of space, not from motives of curiosity, but for the advancement of science, its applicability to useful purposes, and the good of mankind." In commenting on the several ascents thus combined in one description, Mr Glaisher gives us various pieces of information which are highly interesting. The clouds, he says, on which the sun was shining brightly, each moment opened up to view deep ravines, and shining masses appeared like mountain ranges, some rising perpendicularly from rolling seas or plains, with summits of dazzling brightness, some pyramidal, others undulatory, with deep shadows between. While passing over London on one occasion at night, at the height of about one mile, he heard the hum of the great city, and saw its lights. The river looked dull, but the bridges that spanned it, and the many miles of straight, intersecting, and winding streets were distinctly visible. In referring to sound, he tells us that, on different occasions, at a height of 11,800 feet above the earth, a band was heard playing. At between four and five thousand feet a railway whistle and the shouting of people were heard, and at 10,070 feet the report of a gun. A dog was also heard barking at a height of two miles. At a height of 19,000 feet the hands and lips were observed, during one ascent, to be of a dark bluish colour. At four miles the palpitations of the heart were audible, and the breathing was affected. Considerable difficulty was experienced in respiration at higher elevations. From his various observations he found that the effect of high elevation is different upon the same individuals at different times, and believed that, up to heights less than three miles--to which persons of ordinary self-possession might ascend--delicate and accurate scientific observations might be made with ease, but at heights approaching to four miles, such observations could not be made so well, because of the personal distress of the observer, and on approaching to five miles above the earth it required the exercise of a strong will to take any observations at all. The most wonderful and alarming of the experiences of Mr Glaisher appear to have occurred to him and his companion, Mr Coxwell, during an ascent made from Wolverhampton on the 5th September, when they reached the enormous elevation of between six and seven miles. They felt no particular inconvenience until after passing above the fifth mile. When at a height of 26,000 feet, Mr Glaisher could not see the column of mercury in the tube; then the fine divisions on the scale of the instrument became invisible. Shortly afterwards he laid his arm on the table, and on attempting again to use it found that the limb was powerless. He tried to move the other arm, and found that it also was paralysed. He then tried to shake himself, and succeeded in shaking his body, but experienced the curious sensation of having no legs! While in this condition he attempted to look at the barometer, and, while doing so, his head fell on his left shoulder. Struggling to get out of this lethargic state, he found that he could still shake his body, although he could not move either arms or legs. He got his head upright for an instant, but it dropped again on his shoulder, and he fell backwards, his back resting against the side of the car, and his head on its edge. In this position his eyes were directed to Mr Coxwell, who did not at first observe the state of his companion, in consequence of his having had to ascend into the ring of the balloon to disentangle the valve-line, which had become twisted. Hitherto Mr Glaisher had retained the power of moving the muscles of his back and neck, but suddenly this was lost to him. He saw Mr Coxwell dimly in the ring, and attempted to speak to him, but could not do so. A moment later intense black darkness surrounded him--the optic nerve had lost its power! He was still conscious, however, and with his brain as active as at other times. He fancied he had been seized with asphyxia, and that death would quickly ensue unless they descended without delay. Suddenly the power of thought ceased, and he became unconscious. All these extraordinary and alarming sensations, he calculated, must have taken place within five or six minutes. While still powerless he heard the words "temperature" and "observation," and knew that Mr Coxwell was in the car endeavouring to arouse him. Presently he heard him speak more emphatically, but could neither see, reply, nor move. Then he heard him say, "Do try now, do," after which vision slightly returned, and in a short time he saw clearly again, rose from his seat, looked round, and said to Mr Coxwell, "I have been insensible." His friend replied, "You have, and I too, very nearly." Mr Coxwell had lost the use of his hands, which were black; Mr Glaisher, therefore, poured brandy over them. His companion then told him that, on descending from the ring, he thought he had laid himself back to rest, but noticing that his legs projected, and his arms hung down by his side, it struck him there was something wrong, and he attempted to go to his assistance, but felt insensibility coming over himself. He tried to open the valve, so that they might descend, but, having lost the use of his hands, could not. In this critical moment he seized the cord with his teeth, dipped his head two or three times, and thus succeeded in opening the valve, and descending from those dangerous regions of attenuated atmosphere! At first they went down at the tremendous rate of twenty miles an hour, but after descending three miles in nine minutes, the balloon's progress was checked, and they finally alighted safely in a grass field, where their appearance so terrified the country folk that it required a good deal of coaxing in plain English to convince them that the aeronauts were not inhabitants of another world! ------------------------------------------------------------------------ Note 1. _Exeter Hall Lectures--Scientific Experiments in Balloons_, by James Glaisher, Esquire, F.R.S.--Published by James Nisbet and Company, London. CHAPTER SEVEN. ACCOUNT OF NADAR'S BALLOON, "LE GEANT." FIRST ASCENT. As the "Giant" is the largest balloon that has yet been made, and as its experiences on the occasions of its first and second ascents were not only peculiar but terrible, we shall give an account of it in detail-- commencing with its construction, and ending with the thrilling termination of its brief but wild career. Monsieur Nadar, a photographer of Paris, was the enthusiastic and persevering aeronaut who called it into being, and encountered the perils of its ascents, from which he did not emerge scatheless, as we shall see. Besides being an experimental voyager in cloudland, Monsieur Nadar started a newspaper named _L'Aeronaute_, in which he gives an account of the "Giant," and his reasons for constructing it. These latter were peculiar. He is emphatic in asserting that the huge balloon was never intended by him to be an "end," but a mere stepping-stone to an end--which end was the construction of an _aeromotive_--a machine which was to be driven by means of a screw, and which he intended should supersede balloons altogether, so that his own "Giant" was meant to be the last of its race! In reference to this, Monsieur Nadar tells us that he was deeply impressed with the belief that the screw would ultimately become our aerial motor, but that, being ignorant of what it was likely the experiments of this first aeromotive would cost, he had resolved, instead of begging for funds to enable him to accomplish his great end, to procure funds for himself in the following manner:-- "I shall," says he, "make a balloon--the _last balloon_--in proportions extraordinarily gigantic, twenty times larger than the largest, which shall realise that which has never been but a dream in the American journals, which shall attract, in France, England, and America, the crowd always ready to run to witness the most insignificant ascent. In order to add further to the interest of the spectacle--which, I declare beforehand, without fear of being belied, shall be the most beautiful spectacle which it has ever been given to man to contemplate,--I shall dispose under this monster balloon a small balloon (_balloneau_), destined to receive and preserve the excess of gas produced by dilation, instead of losing this excess, as has hitherto been the case, which will permit my balloon to undertake veritable long voyages, instead of remaining in the air two or three hours only, like our predecessors. I do not wish to ask anything of any one, nor of the State, to aid me, even in this question of general, and also of such immense, interest. I shall endeavour to furnish myself the two hundred thousand francs necessary for the construction of my balloon. The said balloon finished, by public ascents and successive exhibitions at Paris, London, Brussels, Vienna, Baden, Berlin, New York, and everywhere, I know that I shall collect ten times the funds necessary for the construction of our first aeromotive." This first aeromotive, however, has not yet made its appearance, whether from want of funds or of practicability we do not know, but Monsieur Nadar carried his designs triumphantly into effect with the "monster balloon," which in course of time made its appearance, performed flights, attracted the wonder and admiration, as well as a good deal of the coin, of hundreds of thousands in France and England, even conveyed royalty up into the clouds, broke the bones of its originator, and was exhibited in the great transept (which it nearly filled) of the Crystal Palace at Sydenham. While there, we had the good fortune to behold it with our own eyes! The construction of this balloon merits particular notice; but first, it may be remarked that it is well worthy of being named a giant, seeing that its height was only forty-five feet less than that of the towers of Notre Dame Cathedral, namely 196 feet. That Nadar had cut out for himself an arduous task will be readily believed. Touching on this, he writes thus:-- "I have set myself to work immediately, and with difficulties, sleepless nights, vexations which I have kept to myself alone to this hour, and which some one of the days of this winter, the most urgent part of my task being finished, I shall in part make in confidence to my readers. I have succeeded in establishing my balloon, in founding at the same time this journal--indispensable _moniteur_ to the aerial automotive-- and in laying the basis of that which shall be, perhaps, the greatest financial operation of the age. Those who shall see and appreciate these labours, will please to pardon me, I hope, for having wiped my forehead with a little touch of pride, when at the end of a month--one month!--I have said to myself, `it is done!'" The "Giant" was composed of yellowish white silk, of which there were used 22,000 yards at about 5 shillings 4 pence a yard, so that the cost of the silk alone was 5,866 pounds. This was cut into 118 gores, which were entirely hand-sewed with a double seam, and some idea of the vastness of the work may be gathered from the fact that 200 women were employed during a month in the sewing of the gores. For the sake of greater strength the silk was doubled. In other words, there were _two_ balloons of the same size, one within the other. Directly beneath, and attached to its lower orifice, there was a small balloon called a _compensator_, the object of which was to receive and retain for use the surplus gas. When a balloon rises to the higher regions of the atmosphere, the gas within it expands, so that a large quantity of it is allowed to rush out at the open mouth beneath, or at the safety-valve above. Were this not the case, the balloon would certainly burst. This loss of gas, however, is undesirable, because when the balloon descends the gas contracts, and the loss is then felt to be a great one. By collecting the over-flow of gas in the _compensator_, this disadvantage is obviated. The car, which was made chiefly of wicker-work, was actually a small cottage of two storeys (a ground-floor and platform or upper deck), with door and windows. Its height was about eight, and its length thirteen feet. The ground-floor contained a cruciform passage and six divisions. At one extremity was a captain's cabin with a bed in it, and underneath a compartment for luggage. At the other was the passengers' cabin, with three beds, one above the other. The four other divisions or rooms were a provision store, a lavatory, a place for conducting photographic operations, and a room for a small lithographic press, with which it was intended to print an account of the voyage, to be scattered about the localities over which they should pass! In reference to this last, Monsieur Nadar writes:-- "An English company a month ago (our neighbours are marvellous in not losing time), appreciating the bustle which the sight of a balloon always excites in every inhabited place, and judging rightly that papers would never be better received and more greedily read than those thrown overboard by us, despatched a messenger to propose to me to accept commercial prospectuses. We shall never have too much money for the construction of our first aeromotive. I have accepted and made a contract." Besides many miscellaneous articles, such as grapnels, fowling-pieces, speaking-trumpets, etcetera, that were to be carried up in this cot, there were provisions of all sorts, instruments for scientific observations, games, means of defence in case of descent among an inhospitable people, and two cages of carrier-pigeons sent from Liege. The car and all it contained was secured by twenty cables traversing on and beneath its walls, interlaced with the fabric and fastened to a large hoop just below the neck, to which hoop was also attached the ropes of the net-work, by which the balloon itself was enveloped. There were two axles and four wheels connected with the car, by means of which it could, when necessary, be drawn along an ordinary road. Canes, disposed to act as springs, were placed underneath and round the middle of it to protect it from concussions, besides which internal buoys and an immense girdle in compartments of inflated india-rubber, rendered it incapable of submersion in water. Such was the giant balloon in which Monsieur Nadar and his friends made two ascents; of the first of which (4th October 1863) Galignani writes thus:-- "The departure of this Leviathan of the airy regions attracted immense crowds to the Champ de Mars yesterday afternoon. Considering that the avenues encircling that vast space were filled to suffocation, so that we found it extremely difficult to force our way to the open ground reserved for tickets, and that all the housetops were occupied by spectators, we think the number of persons present may fairly be stated at 80,000. Ample precautions had been taken to prevent disasters,--a strong police force, supported by a company of infantry and some cavalry, being present to maintain order. The balloon, which is 90 yards in circumference, and has consumed upwards of 20,000 yards of silk in its manufacture, was held down, while filling, by about 100 men, and the weight of at least 200 sandbags. The car was of wicker-work, comprising an inner surface of about 54 square feet divided into three compartments or small rooms, surmounted by an open terrace, to which the balloon was braced. Outside grapnels, wheels, and fowling-pieces, four of each, besides two speaking-trumpets, were lashed to the sides of the car. (The wheels were intended to be put to the car after alighting, in order to convey it back with horses.) The preliminary operations took considerable time, putting the patience of the spectators to a severe trial, a circumstance which perhaps prevented them from cheering when the words `_Lachez tout_!' were given, and the immense machine rose slowly and majestically into the air. We were rather surprised at the silence of the public, considering the very remarkable and interesting feat in aeronautics thus successfully performed. There were fifteen persons in the car, or rather cabin:--Monsieur Nadar, captain; Messieurs Marcel, Louis and Jules Godard, lieutenants; the Prince de Sayn-Wittgenstein, Count de Saint Martin, Monsieur Tournachon (Nadar's brother), Messieurs Eugene Delessert, Thirion, Piallat, Robert Mitchell, Gabriel Morris, Paul de Saint Victor, de Villemessant, and one lady, the Princess de la Tour d'Auvergne. The Princess was taking her usual drive to the Bois de Boulogne, when, observing an unusual movement in the neighbourhood of the Invalides, and having inquired the cause; she ordered her coach man to drive to the Champ de Mars. Having seen the balloon, she expressed a wish to make the ascent, and although Nadar had to the last moment refused to take any lady, and even his own wife, he could not resist the entreaty of the Princess. On starting, Monsieur Nadar climbed up the net-work and took off his hat to the spectators. The balloon took a north-easterly direction, and was visible for some time. At the moment of going to press, a communication has reached us, signed by the captain, Monsieur Nadar, and all those who had taken places in the balloon, stating that on alighting yesterday evening at nine o'clock at Ibarcy, near Meaux (Seine-et-Marne), three severe shocks were experienced, which had the effect of completely capsizing the balloon, and inflicting on its occupants several rather severe contusions. "Interesting details of the ascent of the Nadar balloon, said to have been narrated by Prince Wittgenstein, are given by the _France_. The most extraordinary is, that at half-past eight, when the balloon attained the height of 1500 metres, the aeronauts saw the sun, which had set for the earth below upwards of two hours before. The effect of the light upon the balloon is described as something marvellous, and as having thrown the travellers into a sort of ecstasy. Although they met with no rain, their clothes were all dripping wet from the mist which they passed through. The descent was more perilous than at first reported. The car dragged on its side for nearly a mile, and the passengers took refuge in the ropes, to which they clung. Several were considerably bruised--though, as before stated, no one sustained any very serious injury. Everybody behaved well. Nadar, visibly uneasy about his fair charge, the young Princess de la Tour d'Auvergne, was told by her to attend to his duty as captain. `Every one at his post,' said she; `I will keep to mine.' Notwithstanding all the shaking which the car underwent, the 37 bottles of wine provided for the journey were all found unbroken, and they were most joyously broached when the party got on _terra firma_. The rifles, the crockery, as well as a cake and 13 ices, presented to Nadar by Siraudin, of the Rue de la Paix, were all uninjured. When the descent was effected, the lights and the speaking-trumpets soon attracted a number of peasants, who brought carts and helped the party to the village of Barcy, where most of them passed the night; but Monsieur Nadar and the Prince de Wittgenstein, with two or three others, came to Paris by the first train from Meaux. "It is said that the descent was resolved upon in consequence of the advice of the brothers Godard, and contrary to the wish of Monsieur Nadar, who, as captain, had made every one of his companions sign an agreement to act upon his orders, even though the vote should be unanimously against him. He, however, yielded his opinion, in deference to that of these experienced aeronauts. A truly extraordinary statement is, that they fancied the wind was blowing them to the sea, and certain destruction, whereas they were going due east, with no sea at all before them nearer than the Caspian. "There was great disappointment in the receipts at the Champ de Mars, which are said to have realised only 27,000 francs, whereas 150,000 had been calculated upon. The papers say that the public broke down the barriers and got in for nothing, instead of paying their franc. It is quite certain that at the moment of the ascent there could not have been less than 50,000 people on the Champ de Mars, and on the terraces and heights around there must have been four times that number." Monsieur Nadar, on his return to Paris, wrote as follows:-- "Here, as briefly as possible, is the account which you asked me to send. Yesterday evening at nine o'clock, the `Giant' was compelled to descend near the Barcy Marsh, two leagues from Meaux, after three violent shocks, the last of which completely turned everything in the car topsy-turvy, and it descended on its side. The rupture of our valve-pipe rope while travelling by night, forced us to throw out our anchors. One of the prongs of the first anchor having broken, the principal anchor fortunately took hold of the ground. We were able to let out the gas, notwithstanding the violence of the wind, and the car was set up at half-past one in the morning. Some slight contusions and a concussion of the knee of one of the passengers--that is our receipt in full. It is not too dear. "A. Nadar." This bold and zealous aeronaut unfortunately paid dearer for his succeeding ascent as shall be seen in the next chapter. CHAPTER EIGHT. SECOND ASCENT OF NADAR'S "GIANT" BALLOON. Before describing the second ascent, which was decidedly the more adventurous, we shall give the rules laid down for his party by Monsieur Nadar, which were remarkably stringent, and somewhat amusing:-- "1. Every traveller on board the `Geant' must, before mounting, take knowledge of the present rules, and engage himself upon his honour to respect them, and to make them respected, both in the letter and in the spirit. He accepts and will obey this obligation until the descent. "2. From the departure to the return there shall be only one command, that of the captain. That command shall be absolute. "3. As legal penalty cannot be enforced, the captain, having the responsibility of the lives of the passengers, decides alone, and without appeal, in all circumstances, the means of assuring the execution of his orders with the aid of all under him. The captain can, in certain cases, take the advice of the crew, but his own authority is decisive. "4. Every passenger declares, at the time of ascending, that he carries with him no inflammable materials. "5. Every passenger accepts, by his simple presence on board, his entire part and perfect co-operation in all manoeuvres, and submits himself to all the necessities of the service; above all, to the command of the captain. On landing, he must not quit the balloon without permission duly acquired. "6. Silence must be absolutely observed when ordered by the captain. "7. Victuals and liquors carried up by the travellers must be deposited in the common canteen, of which the captain alone has the key, and who regulates the distribution thereof. Passengers have no claim to victuals and liquors, except when on board. "8. The duration of the journey is not limited. The captain alone decides the limitation; the same judgment decides, without appeal, the putting down of one or more travellers in the course of the voyage. "9. All gambling is expressly prohibited. "10. It is absolutely forbidden to any traveller to throw overboard ballast, or any packet whatever. "11. No passenger can carry up with him luggage exceeding thirty pounds in weight, and occupying more space than a travelling-bag. "12. Except in very rare cases, of which the captain alone shall be judge, it is absolutely forbidden to smoke on board, or on land within the vicinity of the balloon." The second ascent took place on the 18th of October, when Monsieur Nadar, nothing daunted by his former experience, again went up in his "Giant" from the Champ de Mars. On this occasion preliminaries were managed with greater success than on the former, and the event was regarded with much more general interest. Soldiers kept the ground; the Emperor himself was present, and conversed with the bold aeronaut on the subject of his balloon; George the First of Greece was there also, and the crowd which assembled to witness the ascent surpassed all expectation. There were two peculiar features in this second ascent. It had been doubted whether the balloon, which was said to be capable of raising four-and-a-half tons, could carry more than thirteen men. In order to set this question at rest, a short preliminary flight was made with a rope attached to restrain the "Giant." About thirty soldiers were then put into the car, who mounted to the extent of the rope, and were pulled down again. The other feature was that a balloon of more ordinary dimensions was let fly along with the "Giant," to give, by contrast, a better idea of its size. The balloon used for this purpose was the "Godillot," which had been used by the Emperor in the Italian campaign for reconnoitring the enemy. After the usual delays which are inseparable from such displays, Monsieur Nadar, with eight friends, stepped into the car, the rope was let go, and the "Giant" rose slowly towards the clouds, grew "small by degrees and beautifully less," until it finally disappeared about night-fall--being wafted along by a gentle south-easterly breeze. Nothing more was heard of the aeronauts for the next two days, and their friends were becoming naturally very anxious about them, when at last a telegram came from Bremen, dated the 21st, which ran as follows:-- "Nadar's balloon descended near Eystrup in Hanover. There were nine persons in it, of whom three were seriously, and two slightly injured." Other telegrams quickly followed stating that Monsieur Nadar had both legs dislocated; Monsieur Saint Felix had sustained severe fractures and contusions; and that Madame Nadar had also been severely injured. It was stated that the voyagers would probably all have perished if Jules Godard (a celebrated aeronaut, who, with his brother Louis, accompanied Nadar), had not, at the risk of his life, climbed up the net-work, and cut a hole in the silk with a hatchet, so as to allow the gas to escape. By so doing, he stopped the furious course of the balloon, which was making truly gigantic bounds of from forty to fifty yards over the ground, with a violence that would soon have knocked the car to pieces! A full and graphic, but inflated and sentimental account of the voyage-- which was one of real and thrilling interest--is given by one of the voyagers, Monsieur Eugene Arnould, a reporter of the French newspaper _La Nation_. Had Monsieur Arnould confined himself to a simple statement of facts, he would have greatly increased the interest and power of his description. However, we must take him as we find him, and as his account is the most complete--and correct in the main, although exaggerated in detail--we present it to the reader. "At nine o'clock at night [the same night on which they started] we were at Erquelines; we passed over Malines, and towards midnight we were in Holland. We rose up very high, but it was necessary to come down to see where we were. Ignorant of that, our position was a critical one. Below, as far as we could see, were marshes, and in the distance we could hear the roar of the sea. We threw out ballast, and, mounting again, soon lost sight of the earth. What a night! Nobody slept, as you may suppose, for the idea of falling into the sea had nothing pleasant about it, and it was necessary to keep a look-out in order to effect, if necessary, a descent. My compass showed that we were going towards the east--that is to say, towards Germany. In the morning, after a frugal breakfast made in the clouds, we re-descended. An immense plain was beneath us; the villages appeared to us like children's toys--rivers seemed like little rivulets--it was magical. The sun shone splendidly over all. Towards eight o'clock we arrived near a great lake; there I found out our bearings, and announced that we were at the end of Holland, near the sea. "We passed I know not how much time in contemplating the enchanting scene around us; but at length we all felt the necessity of going downwards to see where we were. Presently the balloon came so near to the earth that we could readily distinguish the tall chimneys of a great many flaming furnaces. `If we were to fall upon some of them,' said Montgolfier anxiously. These furnaces told us very clearly that we were in Belgium, and, besides, the Flemish songs that continually reached our ears left no doubt upon the point. Godard, Nadar, all of us, called out frequently to the people below, `Where are we?' but we got no other answer than shouts of laughter. There were two bells in the car, and Yon and myself rang them as hard as we could, while Nadar roared through his speaking-trumpet. I had an opportunity of observing that the purity of the air in no degree attenuates the quantity of false notes lodged in the throats of certain individuals. Our aerial Charivari at length provoked a corresponding one on earth, and we could hear dogs barking, ducks quacking, men swearing, and women screaming. All this had a droll effect; but time went on, the wind blew hard, it was dark night, and our balloon drove on with prodigious rapidity, and we were not able to tell exactly where we were. I could not see my compass, and we were not allowed to light a lucifer match under any pretext whatsoever. From the direction in which we had passed over Lille, we judged that we must be going towards the sea; Louis Godard fancied that he could see lighthouses. We descended again to within 150 yards of the earth. Beneath us we saw a flat marshy country of sinister aspect, and indicating plainly the neighbourhood of the coast. Every one listened with all his ears, and many fancied they heard the murmurs of the sea. The further we went on the more desert the country became: there was no light whatever, and it became more and more difficult to guess where we were going. `I am entirely out of my reckoning,' exclaimed Louis Godard, `and my opinion is that the only thing we have to do is to descend at once.' `What! here in the marshes!' remonstrated all of us; `and suppose we are driven into the sea?' The balloon went driving on still. `We cannot descend here,' said Jules Godard; `we are over water.' Two or three of us looked over the edge of the car, and affirmed that we were not over water, but trees. `It is water,' Jules Godard persisted. Every one now looked out attentively; and, as the balloon descended a little, we saw plainly that there was no water, but without being able to say positively whether there were trees or not. At the moment when Jules Godard thought he saw water, Nadar exclaimed, `I see a railway.' It turned out that what Nadar took for a railway was a canal running towards the Scheldt, which we had passed over a few minutes before. Hurrah for balloons! They are the things to travel in; rivers, mountains, custom-houses,--all are passed without let or hindrance. But every medal has its reverse; and, if we were delighted at having safely got over the Scheldt, we by no means relished the prospect of going on to the Zuyder Zee. `Shall we go down?' asked Louis Godard. There was a moment's pause. We consulted together. Suddenly I uttered a cry of joy; the position of the needle of my compass indicated that the balloon had made a half turn to the right, and was now going due east. The aspect of the stars confirmed this assertion. Forward! was now the cry. We threw out a little ballast, mounted higher, and started with renewed vigour with our backs turned to the depreciated Zuyder Zee. It was now three in the morning, and none of us had slept. Just as we began to try to sleep a little, my diabolical compass showed that the balloon was turning back again. `Where are you going to take us to?' cried out Yon to the immense mass of canvas which was oscillating above our heads. Louis Godard again proposed to descend; but we said, `No! forward! forward!' Two hours sped away without our being able to tell where we were. At five o'clock day broke, and broad daylight came on with marvellous rapidity. It is true that we were at a height of 980 metres. Novel-writers and others have so much abused descriptions of sunrise, on mountains and on the ocean, that I shall say little about this one, although it is not a common thing to see the horizon on fire below the clouds. The finest Venetian paintings could alone give an idea of the luxuriant tones of the heaven that we saw. Such dazzling magnificence led me to wonder that there is no revival of sun worship, since men must necessarily have some material representation of the divinity. It is true that the sun is not made in man's image! We now had beneath us an immense plain, the same, probably, that we had passed over in the night. There is nothing more pleasant at first sight, nor more monotonous in the long-run, than the sort of country which forms at least one-third of Holland. There are miniature woods the size of bouquets, fields admirably cultivated and divided into little patches like gardens, rivers with extraordinary windings, microscopic roads, coquettish-looking villages, so white and so clean that I think the Dutch housewives must scour the very roofs of their houses every morning. In the midst of every village there is a jewel of a church with a shining steeple. While riding along at a height of 700 metres, we had beneath us a picture of Paul Potter's fifty leagues square. All at once the tableaux became animated. The people below had perceived the balloon. We heard cries expressive of astonishment, fright, and even of anger; but the feeling of fright seemed to predominate. We distinctly saw women in their chemises look hurriedly out of windows and then rush back again. We saw chubby boys looking at us, and blubbering as if they were mad. Some men, more determined than the rest, fired off guns at us. I saw several mammas pointing us out to stubborn babies, with an attitude which seemed to say that our balloon was Old Bogy. Old women raised their hands against us, and at their signal many ran away, making the sign of the cross. It is evident that in some of these villages we were taken to be the devil in person. On this point it is _apropos_ to cite a letter communicated to me which has been addressed to the _Courrier de Hanovre_. I translate it textually:-- "`This morning, at about six o'clock, we saw passing over our heads, at a prodigious height, an immense round form, to which was suspended some thing which looked like a square house of a red colour. Some people pretend to have seen animated beings in this strange machine, and to have heard issuing from it superhuman cries. What think you, Mr Editor? The whole country is in a state of alarm, and it will be long before our people recover their equanimity.' "At seven a.m. we crossed over a lake near Yssel; the wind then again pushed us in a new direction, nearly at right angles with that which we were taking before. In less than a quarter of an hour the balloon got into Westphalia near Renheim; then we crossed the great river Ems, the towns of Rheine and Ibbenburen, and returned to Hanover a little above Osnabruck. We traversed, without deigning to take notice of them, a little chain of mountains, and by way, no doubt, of relaxation after so long a journey, went all round a lake which is called in German Dummersee. We then got into a great plain, through which runs a road. At this time the balloon became almost motionless. The reason of this was, that the heat of the sun had caused the gas to expand. The thermometer was then at 145 degrees (about 59 degrees Fahrenheit [No! editor]). Louis Godard was very uneasy about this dilation. After two or three oscillations, our aerial courser decided upon going off rapidly in an eastern direction, with about two degrees variation towards the north. This course would have taken us to Hamburg and the Baltic; but we were all so completely absorbed by the splendour of the tableau before us that we took little note of the change. Our hippogriff passed over Wagenfeld-Steyerberg, where there is a river which flows into the Weser. We came within sight of the great river and Nienburg, a considerable town on one of its banks. We saw a steamboat going down the river from the town. The view here was charming. A rustling of the silk of our balloon made us look upwards; the monster, under the influence of the sun, now very hot, was palpably swelling. As it would have been supremely ridiculous, after having made such a first-rate journey, to have treated the inhabitants of Nienburg with the spectacle of seeing us blown up--to say nothing of the consequences of such a catastrophe to our own limbs--we resolved to come down. The remaining bags of ballast were got in order, the ropes and the anchors prepared, and Godard opened the safety-valve. `The monster is disgorging!' exclaimed Thirion. And the balloon did vomit forth its gas with a tremendous noise, which may be compared to the snoring of some gigantic animal. While our companion made this observation, we were descending at the rate of two metres to the second. `To the ropes! to the ropes!-- hold on well!' cried the brothers Godard, who seemed quite in their element, `take care of the shock!' Every one climbed up to the ropes which attach the car to the circular handles underneath the balloon. Madame Nadar, whose _sang-froid_ was truly magnificent, grasped two large ropes with her delicate hands. Nadar did the like, but at the same time put his arms round his wife so as to protect her body. I was on one side towards the middle of the sort of hurdle which serves as a balcony. I was on my knees and clinging to two ropes. Montgolfier, Thirion, and Saint Felix were near me. The balloon descended so rapidly that it gave us the vertigo. The air, which we had left so calm above, became a violent wind as we neared the earth. `We are going to throw down the anchors,' said Godard, `hold tight!' Ah! the car struck the earth with tremendous violence. I cannot imagine how it was that my arms were not broken. After the first terrible shock the balloon went up again, but the safety-valve was opened--it again fell--and we suffered a second shock, if not more violent, at least more painful to us than the first. Up we went again; the balloon dragged its anchors. Several times we thought we should be thrown out. `The anchors are broken,' exclaimed Godard. The balloon beat the ground with its head, like a kite when it falls down. It was horrible. On we went towards Nienburg, at the rate of ten leagues an hour. Three large trees were cut through by the car, as clean as if by a woodman's hatchet. One small anchor still remained to us. We threw it down, and it carried away the roof of a house. If the balloon had dragged us through the town we should, inevitably, have been cut to pieces. But fortunately it rose a little and then bumped against the ground again with as much violence as before. Every one of these shocks wrenched our limbs; to complete our misfortunes the rope of the safety-valve got loose from us, and the safety-valve shutting up we lost all hope of the balloon emptying itself. It went on by bounds of twenty-five, thirty, and forty metres from the earth, and continued to fall upon its head. Everything that stood in the way of the car was dashed to pieces. "Jules Godard then tried, and accomplished, an act of sublime heroism. He clambered up into the netting, the shocks of which were so terrible that three times he fell on my head. At length he reached the cord of the valve, opened it, and the gas having a way of escape the monster ceased to rise but it still shot along in a horizontal line with prodigious rapidity. There were we squatting down upon the frail osier car. `Take care!' we cried, when a tree was in the way. We turned from it, and the tree was broken; but the balloon was discharging its gas, and if the immense plain we were crossing had yet a few leagues, we were saved. But suddenly a forest appeared in the horizon; we must leap out at whatever risk, for the car would be dashed to pieces at the first collision with those trees. I got down into the car, and raising myself I know not how,--for I suffered from a wound in my knees, my trousers were torn,--I jumped, and made I know not how many revolutions, and fell upon my head. After a minute's dizziness I rose. The car was then far off. By the aid of a stick I dragged myself to the forest, and having gone a few steps I heard some groans. Saint Felix was stretched on the soil frightfully disfigured; his body was one wound; he had an arm broken, the chest torn, and an ankle dislocated. The car had disappeared. After crossing a river I heard a cry. Nadar was stretched on the ground with a dislocated thigh; his wife had fallen into the river. Another companion was shattered. We occupied ourselves with Saint Felix, and Nadar and his wife. In trying to assist the latter I was nearly drowned, for I fell into the water and sank. They picked me up again, and I found the bath had done me good. By the assistance of the inhabitants the salvage was got together. Vehicles were brought; they placed us upon straw. My knees bled; my loins and head seemed to be like mince-meat; but I did not lose my presence of mind an instant, and for a second I felt humiliated at looking from the truss of straw at those clouds which in the night I had had under my feet. It was in this way we reached Rethem, in Hanover. "In seventeen hours we had made nearly 250 leagues. Our _course infernale_ had covered a space of three leagues. Now that it is over I have some shudderings. It does not signify! we have made a good journey, and I marvel to see with what indifference we may regard the most frightful death, for, besides the prospect of being dashed about on our way, we had that of gaining the sea; and how long should we have lived then? I am glad to have seen this--happier yet at having to narrate it to you. These Germans who surround us are brave people, and we have been as well cared for as the resources of the little spot will allow. "P.S.--I have just reached Hanover with my companions, and re-open my letter to tell you so. The King has sent an aide-de-camp to us. Are we at the end of our reverses? At any rate, I am consoled to think they can no longer laugh at us in Paris. We have kept our promises, and more." Making some allowance for the palpable exaggeration of small details, this excitable Frenchman's description of the ascent is the best that we have seen, therefore we have given it in full. The accounts given by other members of the party corroborate most of it, and correct a few of its errors. For instance, where Monsieur Arnould represents the anchor as dragging off the _roof_ of a house, another account states that it tore away one of the rafters; and while he tells us that large trees were "cut through by the car as clean as if by a woodman's hatchet," Monsieur Godard says that they were knocked down or uprooted! But, upon the whole, after comparing the several narratives, we are of opinion that, with all his tendency to exaggeration and the use of inflated language, Monsieur Arnould has found it impossible to convey by means of words an adequate conception of this, perhaps, the most wonderful and thrilling balloon voyage on record. Many dangerous voyages of thrilling interest have been undertaken since this ascent of Monsieur Nadar. We shall just give a brief account of two of these, which occurred at a comparatively recent date, to show the reader that men are not to be deterred by the misfortunes of predecessors from prosecuting inquiries and experiments in this field. A _fete_ was held some years ago in the park of Mr North, Basford, near Nottingham. Amongst the amusements, it was arranged that Mr Coxwell should make a balloon ascent. The balloon was almost new, but not of very large dimensions. After it had been fully inflated, Mr Coxwell tried it, and found there would be some difficulty in ascending in it, owing to its weight. At this juncture, a Mr James Chambers, of Nottingham, who had previously made many ascents, stepped forward and offered to go in his stead, saying that he was lighter than Mr Coxwell, and that he wished to make the ascent. After some conversation, it was agreed that Chambers should go up, but Mr Coxwell told him not to attempt an ascent unless he felt quite confident that he could manage the balloon. Chambers replied that he had no fear about managing it, and accordingly he was allowed to make the ascent. The balloon rose steadily, and was carried somewhat rapidly in a north-easterly direction towards Nottingham. It proceeded as far as Arno Vale, when it was seen suddenly to collapse, while still at a considerable altitude, and then to fall quickly in an unshapely mass. Some young men who were near the spot where the balloon fell, hastened to render assistance. The balloon dropped into the car as it descended, completely covering it, and ultimately both fell in a field near Scout Lane, three miles from Nottingham. The car struck the ground and rebounded several feet, and then fell again, when it was seized and stopped by the young men, who had followed it. At the bottom of the car lay stretched the body of the unfortunate aeronaut. He was lifted out and found to be breathing, but quite insensible. He was conveyed to the nearest dwelling, and means were adopted to restore animation, but without effect. Two medical gentlemen, named Robertson and Maltby, afterwards saw him, and it was discovered that his left thigh was fractured, and some of the ribs on his left side were broken, but they considered it very probable that the unfortunate man had died through suffocation, as a handkerchief, which had been found in his mouth, had probably been placed there by himself when he found that he was in danger of being stifled by the gas from the collapsing balloon. On another occasion, still more recent, a perilous balloon voyage was accomplished by an aeronaut named Vouens. He ascended from the Bellevue Gardens, near Huddersfield, in a balloon which was capable of containing 20,000 cubic feet of gas. Its height was 50 feet, and it expanded to 100 feet in circumference. Away floated the balloon in a westerly direction, oscillating for a considerable distance in a most extraordinary and unusual manner. Mr Vouens experienced a stronger breeze than he had anticipated, and, the current changing rapidly, his energy and knowledge as an aeronaut were very severely taxed. A fresh current drove him to the east for a time, but presently another gust unexpectedly sent him in the direction of Halifax, and thence towards Bradford, in a northerly course. After the lapse of twenty minutes the balloon and its occupant pierced the clouds. Mr Vouens then began to make observations, for the purpose of selecting a suitable site, on which to descend; and in a few minutes concentrated his attention upon a field, in which a _fete_ was being held. The breeze, however, carried him some three miles further, and a second time Mr Vouens attempted to lower himself in a field adjoining some farm-houses at Denholme. Cautiously opening the escape-valve, he continued the journey downwards, and threw out the grapnels. Impetuous blasts of wind increased the difficulty of bringing the balloon to anchor. A strong wind prevailing, it became unmanageable, and drifted over fields and stone walls with amazing velocity. The flukes of the grapnels penetrated the ground and uprooted the earth as they followed in the wake of the balloon, while the aerial chariot dashed onwards, making, in its career, wide gaps in several stone walls. Mr Vouens, preparing to encounter the worst fate, wrapped the end of the cord which opens the escape-valve round one of his wrists, and, burying himself in the car, permitted the balloon to proceed until the breeze subsided, when, after the car had been thrice capsized, and every article which it contained thrown out, Mr Vouens, who received no injuries, anchored, and completed a voyage of many miles, which occupied half-an-hour in its accomplishment. CHAPTER NINE. WAR-BALLOONS. As the French were the first to teach mankind the art of navigating the air by means of balloons, so they were the first to set the example of applying them to the art of war. It may not be generally known, perhaps, that balloons have actually been used in war. They were first introduced to this new field of action at Valenciennes in 1793, and the result of the experiment was a failure; not, however, owing to the fault of man, but to the unpropitious nature of the winds. The garrison, being hard pressed by the English and their allies, attached a letter, addressed to the National Assembly, to a small balloon, or parachute, and committed it to a breeze which blew in the direction of Paris. Towards evening the wind changed, and the faithless messenger fell into the enemy's camp! About the same time the subject of war-balloons was brought before the Committee of Public Safety, who commissioned a young captain of Engineers, named Coutelle, to make experiments, and report on the matter. He made a balloon twenty-seven feet in diameter, with a car to hold two persons, which, when filled with hydrogen gas, was capable of lifting about a quarter of a ton, and cost a little above 80 pounds. It was not intended that this balloon should go free. It was to be held down by two guy-ropes, each between four and five hundred yards in length, by which, when at the full length of its tether, the balloon was to be hauled about in any direction, pulled down, or allowed to rise in obedience to the wishes of the aeronaut, who was to communicate his orders by means of a system of signals. Reports of what he might be thus enabled to discover of the enemy's position were to be written on slips of paper, put into small sandbags, and tossed overboard. Small coloured flags were attached to each bag, so that it might be easily observed in its descent. After several satisfactory ascents to the height of above 500 feet had taken place--the balloon being held easily by ten men, five to each guy-rope--an order was given, in April 1794, for the formation of a company of military aeronauts--styled _aerostiers_, to which Coutelle was appointed captain-commandant. His company consisted of one lieutenant, one sergeant-major, one sergeant, two corporals, and twenty privates, who wore a dark blue uniform, with black velvet facings, and were armed with pistols and swords. This new and peculiar company of aerostiers was very soon sent to join the army at Maubeuge, and was regarded with some ridicule and contempt by the rest of the army. Coutelle, however, took an effectual method of commanding respect. He begged that he and his men might be allowed to take part in a projected _sortie_. They were permitted, and went; an officer and private were wounded, and the corps behaved with such gallantry that it was from that time treated with becoming respect. Ascents were made daily in the balloon for reconnoitring purposes, and the Austrians fired at their audacious and inquisitive enemy both with muskets and cannon, but without effect. After a time the balloon was ordered to take the road, and join that part of the army which was marching on Charleroi. Its march through the country in leading-strings was curious to spectators and harassing to the aerostiers. The car, with all its appurtenances, was placed on a cart, over which the balloon was allowed to float at a height sufficient to admit of the passage of cavalry under it. Twenty men, marching in single file, held it down by twenty stays; but they had a sad time of it, for their charge was headstrong and restive, jerking and tugging at them continually, not only with its own inherent power of ascension, but with the irregular impetus derived from gusts and squalls of wind, which caused it to make sudden and violent charges against trees, houses, or whatever chanced to come in its way, and sometimes to beat its blunt forehead wildly on the ground as if it had been a monster in despair! It reached Charleroi, however, on the 22nd of June, after a journey of three days, and took part in the battle of Fleurus on the 26th. A high wind rendered it necessary, on the day of battle, to fasten its guy-ropes to thirty horses--fifteen to each rope--and, thus secured, it remained in the air eight hours, passing from place to place, and making observations. Its services were so highly appreciated by the generals on that occasion that a second balloon was made and sent to the field of action. The first one, which was named _l'Entreprenant_, met with accidents which rendered it necessary that it should be sent to Maubeuge for repair; but it afterwards rejoined the army and took part in the battle of Aldenhoven, at the capture of Bonn, and at the operations before Ehrenbreitstein, in all of which it escaped without a wound, although frequently exposed to a furious fire of musketry and shells from the exasperated Austrians. Nevertheless, its natural enemy, the wind, did not allow it to escape scatheless, as Coutelle shows in one of his letters. He writes thus: "I received orders to make a reconnaissance of Mayence. I accordingly posted myself between our lines and the town, at about half cannon-shot distance. The wind was very high, so, to counteract its effects as far as lay in my power, I ascended alone, with two hundred pounds additional buoyancy. I was at a height of five hundred metres when three successive gusts dashed me to the ground with such violence that several portions of the car were smashed to bits. Each time the balloon darted up again with so much force that sixty-four men--thirty-two at each guy-rope--were dragged to some distance. Had the guys been made fast to grapnels, as had been suggested to me, they must infallibly have given way." Notwithstanding this rough treatment, the aerial warrior managed, during a lull in the wind, to count the number of the enemy's guns. But the successes of these war-balloons were sadly intermingled with reverses of fortune and harassing difficulties. The aeronauts had, indeed, won the respect and admiration of the army, but this did not compensate for the terribly fatiguing work of holding on, with scarcely a moment's intermission, to the ropes of the intractable monsters during long and frequent marches. The second balloon at length succeeded in breaking loose, and was so much damaged as to become unserviceable, and the first one was afterwards found riddled with balls--destroyed, it was supposed, by its own men, who had become tired of the hardships to which they were continually subjected. The balloon was repaired, but was taken prisoner at Wurtzburg in September 1796, after a short but brilliant, and, it is said, useful career. After this the war-ballooning fell into disrepute. Some attempts have been made in modern times to revive it, but these are not worth mentioning. CHAPTER TEN. AERIAL LOCOMOTIVES, ETCETERA. Having treated of the balloon in all its different aspects, it is both just and appropriate to conclude with an account of the theory and construction of that curious machine which is, according to some enthusiastic aeronauts, to supplant the balloon altogether, and enable us to accomplish that which has been one of the great aims and desires of mankind from the earliest ages, namely, the directing of our flight, or steering a course, not only through, but, if need were, in opposition to the winds. Monsieur Nadar being, perhaps, the most zealous advocate of this machine, we draw our information chiefly from his writings. Of course the reader will understand that we do not support the views which we are about to set forth; neither, however, do we treat them lightly, because we have lived long enough to see proposals which, not many years ago, would have been deemed worthy of the most visionary of lunatics, carried out to a successful issue and reduced to sober facts. When we hear of a _flying machine_ which is to rise from the earth at the bidding of man, and, like the fabulous creations in the _Arabian Nights' Entertainment_, dart through the air with passengers and luggage bound for definite localities, turning hither and thither, or alighting on the earth according to the will of a steersman--we confess to a feeling which is apt to wrinkle our visage with the smile of incredulity; but we sternly rebuke the smile, for we know that similar smiles wreathed the faces of exceedingly wise people when, in former days, it was proposed to drive ships and coaches by steam, and hold instantaneous converse with our friends across the Atlantic by means of electricity! Let us therefore gravely consider the aerial locomotive. Monsieur Nadar, as the reader already knows, scouts the idea of steering balloons. In reference to this he states with truth that, "a balloon which presents to the action of the atmosphere a volume of from 22,000 to 42,000 [cubic] feet of a gas from ten to fifteen times lighter than air, is, by its very nature, smitten with incapacity to struggle against the slightest current, no matter what may be the resisting motive force which may be imparted to it. Both by its constitution, and by the medium which drives it hither and thither at the pleasure of the winds, it can never become a vessel. It is a buoy, and remains a buoy." Discarding, therefore, with contempt, the balloon as an aerial locomotive, he announces his belief that it is the _screw_ which is destined to drive us, or clamber with us, into the blue vault above, and convey us from place to place. And here it is right to assure the reader that the theoretical power of the screw to accomplish the end in view is not a disputable question. It has been practically proved by models, and the only point that remains to be settled is the possibility of applying the power to machines large enough to carry human beings with a sufficient degree of safety to warrant risking the attempt. Monsieur Nadar sets out with a statement which he deems self-evident, namely, that, "in order to contend against the air, we must be specifically heavier than the air"--a truth which was also, we are told, announced by the first Napoleon in the epigrammatic sentence, "There can be no progress without resistance." From this the Frenchman proceeds to prove that, in order to command the air, it is necessary to support one's-self upon it, instead of being at its mercy; that we can only rest upon that which resists, and that the air itself furnishes us amply with the needful resistance--it being "the same atmosphere which overturns walls, tears up by the root trees a century old, and enables ships to ascend impetuous currents." Glowing with the ardour of a man whose faith is refreshingly great, he tells us that the time has at last come when the atmosphere must yield to man. "It is for man," he says, "to restrain and subdue this insolent and abnormal rebellion, which has for so many years laughed at our vain efforts. We are in turn about to make it serve us as a slave, just as the water on which we launch the ship, as the solid earth on which we press the wheel!" There is a toy called the _spiralifer_, which is common enough in towns, and which is, doubtless, known to almost every one. It consists of four flat fans attached to a spindle somewhat after the manner of the arms of a windmill. It is placed in a hollow tube and made to spin violently by pulling a string wound round the spindle. The result is that the spiralifer leaps out of the hollow tube and ascends powerfully as long as the violent spinning motion continues. If properly constructed, this toy acts with great force and certainty, and if the spinning motion could only be kept up, by any means, the ascent would be continued. The principal here involved is precisely the same as that which causes a windmill to turn, a screw-propeller to drive a ship, and a cork-screw to enter a cork. It is pressure against a resisting medium. Air is the resisting medium in the case of the mill; water and cork respectively in the other cases. The only difference between the windmill and the spiralifer is, that the first is moved by the air pressing against it, the other by itself, in its rotatory action, pressing against the air. If you turn a bottle upside down, and, while in that position, send a cork-screw up into the cork, you set in motion the same force which is applied in the spiralifer. As the screw screws itself up into the cork, so the spiralifer screws itself up into the air. Of course the screw remains sticking there when the motive power ceases, because of the density of the medium through which it moves, while the spiralifer, when at rest, sinks, because of the fluidity of the air; but the principle of motion in each is the same. The screw-propeller of a ship is just a spiralifer placed horizontally, acting on water instead of air, and having a vessel placed in front of it. Now, Monsieur Nadar's aerial locomotive is a huge spiralifer, made strong enough to carry up a steam-engine which shall keep it perpetually spinning, and, therefore, perpetually ascending. Perhaps we should have said that his locomotive is a huge machine to which several spiralifers are attached, so that while one set raises or (by reversing the engine) depresses it, other sets drive it sideways. The theory is perfect, and the practice has been successfully attempted in models. Messieurs Ponton d'Amecourt and de la Laudelle, we are told--"the one a man of the world, and the other a man of letters"--engaged the services of two skilled mechanics, Messieurs Joseph of Arras and J. Richard, who constructed models of machines which ascended the atmosphere, carrying their motive power (springs) along with them. Besides horizontal screws, it is proposed to furnish additional guiding power to the locomotive by means of inclined planes. These, by being arranged in various positions, while the machine is in motion, would act on the air, as do the wings of a bird, and give it direction. No doubt, despite the simplicity of all this, difficulties will present themselves to most minds, some of which may perhaps bulk very large in the minds of mechanicians--such as the power of materials to withstand the violence of the forces, to which they are to be applied, etcetera. We do not know; however, no difficulties seem to have afflicted Monsieur Nadar, who thus grandly waives them all aside, and revels in the contemplation of the triumphant flights that lie before him in the future:-- "It will be understood," he writes, "that it belongs not to us to determine at present either the mechanism or the necessary manoeuvres. Neither shall we attempt to fix even approximately the future velocity of the aerial locomotive. Let us rather attempt to calculate the probable velocity of a locomotive gliding through the air, without the possibility of running off the rails, without any oscillation, without the least obstacle. Let us fancy such locomotive encountering on its way, in the midst, one of those atmospheric currents which travel at the rate of forty leagues an hour, and following that current; add together these formidable data, and your imagination will recoil in adding still further to these giddy velocities, that of a machine falling through an angle of descent of from 12,000 to 15,000 feet in a series of gigantic zigzags, and making the tour of the globe in a succession of fantastic leaps." Truly Monsieur Nadar seems to us to be right! There are few men or women, we suspect, who would not recoil from such "fantastic leaps," and unless the prospect of a more sedate style of travelling be held out, it is not probable that aerial locomotives will receive much patronage from the general public. Lord Carlingford, who mistook the sentiments of Monsieur Nadar in regard to the aerial locomotive, claimed for himself, in 1863, the honour of having previously invented and successfully launched an aerial chariot, weighing seventeen stone, which rose on the air without any assistance but that of the wind, and, having arrived at a horizontal position on the air, it remained stationary there until pulled down. Monsieur Nadar, at the conclusion of a courteous letter in reply to this claim, gives his intentions and opinions on the subject pretty clearly as follows:-- "In fine, and that there may be no possible mistake on the part of any one regarding what I am attempting, I desire to find the necessary resources for the constitution of a society, which shall be the centre of all hitherto isolated and therefore lost attempts to solve a question so profound, so vast, so complex that it does not seem to belong to a single individual to achieve it. I have my system, which I believe to be good, since it is mine; but I shall aid with all the strength of my will, and with all the energy of my perseverance, every system which shall be proved to be better than mine. The question to me is not at all who may have determined the great problem; it is that the solution may be found at last. The fruit is ripe; I long to see it plucked, no matter by whom; and this is the sole cause of the agitation which I have endeavoured to call forth, and which I am now pursuing." A man who takes up a subject with such hearty enthusiasm, and in such a liberal spirit, is, we hold, entitled to the utmost respect. As we have, however, done our best to lay his case before the public, we feel entitled to express with all humility some of the doubts which have been suggested to our own mind while meditating on the subject. No doubt the theory propounded is correct, and, as carried into practice with models, the aerial locomotive has been a great success. No doubt also it is pleasant to contemplate the possibility of traversing space like a bird, a meteor, or a comet, and the absolute impossibility of "getting off the rails;" but what, we would ask, would be the result of a hitch--ever so small--in the working of the steam-engine or of the spring motor? If a railway engine breaks down, there are all sorts of chances of escape open to the traveller. The engine may not quit the rails, or it may bound off alone, snap the coupling chains and leave the carriages to run until they come to a gradual standstill; or, the concussion may be so modified that no serious injury may result; or, should it come to the worst, the traveller may be among the fortunate number who make "miraculous escapes." But if a crank of an aerial machine should snap while it is careering through space, or even a screw get loose and cause a momentary stoppage of the motor, it is abundantly evident that escape from total and swift destruction would be "miraculous" indeed, for the whole affair would come to the ground like a thunderbolt, and "leave not a wrack behind!" Probably it might be answered in reply that a parachute attached to the machine, or the inclined planes acting as a parachute, would moderate the descent. Well, there may be _something_ in that; nevertheless, parachutes have not yet proved themselves to be very trustworthy,--and we are constrained to reiterate the fact, that while an accident causing the break-down of the motive power of a steamboat or a railway carriage does not necessarily involve fatal consequences, an accident which should stop the motive power in an aerial locomotive would _almost_ to a certainty, result in a grand smash, which would involve machine and passengers in one inconceivable whirl of chaotic destruction. Whether this machine shall ever be successfully completed or not, it is evident that it still engages the earnest attention of men, as we gather from the following paragraph recently published in the _San Francisco Bulletin_:-- "At a meeting of the Aerial Navigation Company, held on Friday, July 24, 1869, in San Francisco, it was voted to raise the necessary funds to construct an improved avitor of large size. The opinion of the engineers of the company was unanimous as to success so far, and the feasibility and success of the projected flying-ship. It will be about 150 feet in length, 20 to 40 feet diameter of the gasometer, with propelling blades on each side of the centre, describing a radius of about 16 feet. The propellers are shaped like a steamship's, with two blades, each very light. They will be driven by a steam-engine of five-horse power, weighing, with boiler connections and water, 430 pounds weight. The planes on each side for floating the machine will be about twenty feet wide at the centre of the machine, and made in sections, so that they can be depressed or elevated at pleasure with the rudder or tail. The gasometer will be made in sections, so that in the event of accident to one section, the remainder will be sufficient for all practical purposes; indeed, it is claimed that the ship can fly through the air with such speed that the sustaining power of the planes alone will be sufficient to maintain the avitor in mid-air. The gasometer will be made, probably, of thin muslin or silk, saturated with gutta-percha. It is to carry four persons, and will be ready for trial in sixty or ninety days. The result of this experiment will be looked for with great interest all over the country." The Americans, with that vigour of conception and promptitude in action for which they are celebrated, have done a good deal in the cause of aerostation; but, as their doings and experiences have been in many respects similar to those men whose voyages have been already recounted or touched upon, it would involve too much repetition to detail them here. Some of their attempts, however, have outshone those of the men of the eastern hemisphere. For instance, Mr J. Wise, a noted aeronaut, has several times exploded his balloons while in the air, to show that the fragments with net-work form a sort of parachute which moderates the descent. He also, with Mr La Mountain and others, accomplished in 1859 the longest flight on record, namely, 1150 miles in less than twenty hours; and the latter gentleman did 300 miles in four hours in the same year. Another American, Mr Lowe, made an enormous balloon, with which he resolved to cross the Atlantic in about 48 hours. We await the accomplishment of this feat with much solicitude! In conclusion, we may say that the subject of aerostation is still in its infancy, and that we have still to learn how to conduct ourselves properly when--Up in the Clouds. THE END. 
21791	----	[Illustration: THE FLIGHT FOLK.] THE AEROPLANE SPEAKS BY H. BARBER, A.F.Ae.S. (CAPTAIN, ROYAL FLYING CORPS) WITH 36 FULL PAGES OF "TYPES OF AEROPLANES" AND 87 SKETCHES AND DIAGRAMS _FIFTH EDITION_ LONDON McBRIDE, NAST & CO., LTD. THE AEROPLANE SPEAKS. _First edition--December, 1916_ _Second edition--February, 1917_ _Third edition--April, 1917_ _Fourth edition--July, 1917_ _Fifth edition--December, 1917_ FIRST REVIEWS: =C. G. G. in the AEROPLANE:= "One hopes that the Subaltern Flying Officer will appreciate the gift which the author has given him out of his own vast store of experience, for the book contains the concentrated knowledge of many expensive years in tabloid form, or perhaps one should say in condensed milk form, seeing that it is easy to swallow and agreeable to the taste, as well as wholesome and nourishing. And, besides the young service aviator, there are thousands of young men, and women also, now employed in the aircraft industry, who will appreciate far better the value of the finicky little jobs they are doing if they will read this book and see how vital is their work to the man who flies." =THE FIELD:= "Entirely different from any other text-book on the subject, not merely in its form, but in its capacity to convey a knowledge of the principles and practice of flying. Undoubtedly it is the best book on its subject." =THE UNITED SERVICE GAZETTE:= "Should be in the hands of every person interested in aviation." =THE OUTLOOK:= "As amusing as it is instructive." =THE MORNING POST:= "Should be read and re-read by the would be and even the experienced pilot." PRINTED IN ENGLAND BY BILLING AND SONS, LIMITED GUILDFORD DEDICATED TO THE SUBALTERN FLYING OFFICER MOTIVE The reasons impelling me to write this book, the maiden effort of my pen, are, firstly, a strong desire to help the ordinary man to understand the Aeroplane and the joys and troubles of its Pilot; and, secondly, to produce something of _practical_ assistance to the Pilot and his invaluable assistant the Rigger. Having had some eight years' experience in designing, building, and flying aeroplanes, I have hopes that the practical knowledge I have gained may offset the disadvantage of a hand more used to managing the "joy-stick" than the dreadful haltings, the many side-slips, the irregular speed, and, in short, the altogether disconcerting ways of a pen. The matter contained in the Prologue appeared in the _Field_ of May 6th, 13th, 20th, and 27th, 1916, and is now reprinted by the kind permission of the editor, Sir Theodore Cook. I have much pleasure in also acknowledging the kindness of Mr. C. G. Grey, editor of the _Aeroplane_, to whom I am indebted for the valuable illustrations reproduced at the end of this book. CONTENTS _PROLOGUE_ PAGE _PART I.--THE ELEMENTARY PRINCIPLES AIR THEIR GRIEVANCES_ 1 _II.--THE PRINCIPLES, HAVING SETTLED THEIR DIFFERENCES, FINISH THE JOB_ 15 _III.--THE GREAT TEST_ 27 _IV.--CROSS COUNTRY_ 38 CHAPTER I.--FLIGHT 55 II.--STABILITY AND CONTROL 70 III.--RIGGING 90 IV.--PROPELLERS 115 V.--MAINTENANCE 126 TYPES OF AEROPLANES 130 GLOSSARY 133 THE AEROPLANE SPEAKS PROLOGUE PART I THE ELEMENTARY PRINCIPLES AIR THEIR GRIEVANCES The Lecture Hall at the Royal Flying Corps School for Officers was deserted. The pupils had dispersed, and the Officer Instructor, more fagged than any pupil, was out on the aerodrome watching the test of a new machine. Deserted, did I say? But not so. The lecture that day had been upon the Elementary Principles of Flight, and they lingered yet. Upon the Blackboard was an illustration thus: [Illustration] "I am the side view of a Surface," it said, mimicking the tones of the lecturer. "Flight is secured by driving me through the air at an angle inclined to the direction of motion." "Quite right," said the Angle. "That's me, and I'm the famous Angle of Incidence." "And," continued the Surface, "my action is to deflect the air downwards, and also, by fleeing from the air behind, to create a semi-vacuum or rarefied area over most of the top of my surface." "This is where I come in," a thick, gruff voice was heard, and went on: "I'm the Reaction. You can't have action without me. I'm a very considerable force, and my direction is at right-angles to you," and he looked heavily at the Surface. "Like this," said he, picking up the chalk with his Lift, and drifting to the Blackboard. [Illustration: The action of the surface upon the air.] "I act in the direction of the arrow R, that is, more or less, for the direction varies somewhat with the Angle of Incidence and the curvature of the Surface; and, strange but true, I'm stronger on the top of the Surface than at the bottom of it. The Wind Tunnel has proved that by exhaustive research--and don't forget how quickly I can grow! As the speed through the air increases my strength increases more rapidly than you might think--approximately, as the Square of the Speed; so you see that if the Speed of the Surface through the air is, for instance, doubled, then I am a good deal more than doubled. That's because I am the result of not only the mass of air displaced, but also the result of the Speed and consequent Force with which the Surface engages the Air. I am a product of those two factors, and at the speeds at which Aeroplanes fly to-day, and at the altitudes and consequent density of air they at present experience, I increase at about the Square of the Speed. "Oh, I'm a most complex and interesting personality, I assure you--in fact, a dual personality, a sort of aeronautical Dr. Jekyll and Mr. Hyde. There's Lift, my vertical part or _component_, as those who prefer long words would say; he always acts vertically upwards, and hates Gravity like poison. He's the useful and admirable part of me. Then there's Drift, my horizontal component, sometimes, though rather erroneously, called Head Resistance; he's a villain of the deepest dye, and must be overcome before flight can be secured." [Illustration] "And I," said the Propeller, "I screw through the air and produce the Thrust. I thrust the Aeroplane through the air and overcome the Drift; and the Lift increases with the Speed, and when it equals the Gravity or Weight, then--there you are--Flight! And nothing mysterious about it at all." "I hope you'll excuse me interrupting," said a very beautiful young lady, "my name is Efficiency, and, while, no doubt, all you have said is quite true, and that, as my young man the Designer says, 'You can make a tea-tray fly if you slap on Power enough,' I can assure you that I'm not to be won quite so easily." "Well," eagerly replied the Lift and the Thrust, "let's be friends. Do tell us what we can do to help you to overcome Gravity and Drift with the least possible Power. That obviously seems the game to play, for more Power means heavier engines, and that in a way plays into the hands of our enemy, Gravity, besides necessitating a larger Surface or Angle to lift the Weight, and that increases the Drift." "Very well," from Efficiency, "I'll do my best, though I'm so shy, and I've just had such a bad time at the Factory, and I'm terribly afraid you'll find it awfully dry." [Illustration] "Buck up, old dear!" This from several new-comers, who had just appeared. "We'll help you," and one of them, so lean and long that he took up the whole height of the lecture room, introduced himself. "I'm the High Aspect Ratio," he said, "and what we have got to do to help this young lady is to improve the proportion of Lift to Drift. The more Lift we can get for a certain area of Surface, the greater the Weight the latter can carry; and the less the Drift, then the less Thrust and Power required to overcome it. Now it is a fact that, if the Surface is shaped to have the greatest possible span, _i.e._, distance from wing-tip to wing-tip, it then engages more air and produces both a maximum Reaction and a better proportion of Lift to Drift. "That being so, we can then well afford to lose a little Reaction by reducing the Angle of Incidence to a degree giving a still better proportion of Lift to Drift than would otherwise be the case; for you must understand that the Lift-Drift Ratio depends very much upon the size of the Angle of Incidence, which should be as small as possible within certain limits. So what I say is, make the surface of Infinite Span with no width or _chord_, as they call it. That's all I require, I assure you, to make me quite perfect and of infinite service to Miss Efficiency." [Illustration] "That's not practical politics," said the Surface. "The way you talk one would think you were drawing £400 a year at Westminster, and working up a reputation as an Aeronautical Expert. I must have some depth and chord to take my Spars and Ribs, and again, I must have a certain chord to make it possible for my Camber (that's curvature) to be just right for the Angle of Incidence. If that's not right the air won't get a nice uniform compression and downward acceleration from my underside, and the rarefied 'suction' area over the top of me will not be as even and clean in effect as it might be. That would spoil the Lift-Drift Ratio more than you can help it. Just thrust that chalk along, will you? and the Blackboard will show you what I mean." "Well," said the Aspect Ratio, "have it your own way, though I'm sorry to see a pretty young lady like Efficiency compromised so early in the game." "Look here," exclaimed a number of Struts, "we have got a brilliant idea for improving the Aspect Ratio," and with that they hopped up on to the Spars. "Now," excitedly, "place another Surface on top of us. Now do you see? There is double the Surface, and that being so, the proportion of Weight to Surface area is halved. That's less burden of work for the Surface, and so the Spars need not be so strong and so deep, which results in not so thick a Surface. That means the Chord can be proportionately decreased without adversely affecting the Camber. With the Chord decreased, the Span becomes relatively greater, and so produces a splendid Aspect Ratio, and an excellent proportion of Lift to Drift." "I don't deny that they have rather got me there," said the Drift; "but all the same, don't forget my increase due to the drift of the Struts and their bracing wires." "Yes; I dare say," replied the Surface, "but remember that my Spars are less deep than before, and consequently I am not so thick now, and shall for that reason also be able to go through the air with a less proportion of Drift to Lift." "Remember me also, please," croaked the Angle of Incidence. "Since the Surface has now less weight to carry for its area, I may be set at a still lesser and finer Angle. That means less Drift again. We are certainly getting on splendidly! Show us how it looks now, Blackboard." And the Blackboard obligingly showed them as follows: [Illustration] "Well, what do you think of that?" they all cried to the Drift. "You think you are very clever," sneered the Drift. "But you are not helping Efficiency as much as you think. The suction effect on the top of the lower Surface will give a downward motion to the air above it and the result will be that the bottom of the top Surface will not secure as good a Reaction from the air as would otherwise be the case, and that means loss of Lift; and you can't help matters by increasing the gap between the surfaces because that means longer Struts and Wires, and that in itself would help me, not to speak of increasing the Weight. You see it's not quite so easy as you thought." At this moment a hiccough was heard, and a rather fast and rakish-looking chap, named Stagger, spoke up. "How d'ye do, miss," he said politely to Efficiency, with a side glance out of his wicked old eye. "I'm a bit of a knut, and without the slightest trouble I can easily minimize the disadvantage that old reprobate Drift has been frightening you with. I just stagger the top Surface a bit forward, and no longer is that suction effect dead under it. At the same time I'm sure the top Surface will kindly extend its Span for such distance as its Spars will support it without the aid of Struts. Such extension will be quite useful, as there will be no Surface at all underneath it to interfere with the Reaction above." And the Stagger leaned forward and picked up the Chalk, and this is the picture he drew: [Illustration] Said the Blackboard, "That's not half bad! It really begins to look something like the real thing, eh?" "The real thing, is it?" grumbled Drift. "Just consider that contraption in the light of any one Principle, and I warrant you will not find one of them applied to perfection. The whole thing is nothing but a Compromise." And he glared fixedly at poor Efficiency. "Oh, dear! Oh, dear!" she cried. "I'm always getting into trouble. What _will_ the Designer say?" "Never mind, my dear," said the Lift-Drift Ratio, consolingly. "You are improving rapidly, and quite useful enough now to think of doing a job of work." "Well, that's good news," and Efficiency wiped her eyes with her Fabric and became almost cheerful. "Suppose we think about finishing it now? There will have to be an Engine and Propeller, won't there? And a body to fix them in, and tanks for oil and petrol, and a tail, and," archly, "one of those dashing young Pilots, what?" "Well, we are getting within sight of those interesting Factors," said the Lift-Drift Ratio, "but first of all we had better decide upon the Area of the Surfaces, their Angle of Incidence and Camber. If we are to ascend as quickly as possible the Aeroplane must be _slow_ in order to secure the best possible lift-drift ratio; for the drift of the struts, wires, body, etc., increases approximately as the square of the speed, but it carries with it no lift as it does in the case of the Surface. The less speed then, the less such drift, and the better the Aeroplane's proportion of lift to drift; and, being slow, we shall require a _large Surface_ in order to secure a large lift relative to the weight to be carried. We shall also require a _large Angle of Incidence_ relative to the horizontal, in order to secure a proper inclination of the Surface to the direction of motion, for you must remember that, while we shall fly upon an even keel and with the propeller thrust horizontal (which is its most efficient attitude), our flight path, which is our direction of motion, will be sloping upwards, and it will therefore be necessary to fix the Surface to the Aeroplane at a very considerable angle relative to the horizontal Propeller Thrust in order to secure a proper angle to the upwards direction of motion. Apart from that, we shall require a larger Angle of Incidence than in the case of a machine designed purely for speed, and that means a correspondingly _large Camber_. "On the other hand, if we are thinking merely of Speed, then a _small Surface_, just enough to lift the weight off the ground, will be best; also a _small Angle_ to cut the Drift down, and that, of course, means a relatively _small Camber_. "So you see the essentials for _Climb_ or quick ascent and for _Speed_ are diametrically opposed. Now which is it to be?" "Nothing but perfection for me," said Efficiency. "What I want is Maximum Climb and Maximum Speed for the Power the Engine produces." And each Principle fully agreed with her beautiful sentiments, but work together they would not. The Aspect Ratio wanted infinite Span, and hang the Chord. [Illustration: Maximum Climb. Maximum Speed.] The Angle of Incidence would have two Angles and two Cambers in one, which was manifestly absurd; the Surface insisted upon no thickness whatever, and would not hear of such things as Spars and Ribs; and the Thrust objected to anything at all likely to produce Drift, and very nearly wiped the whole thing off the Blackboard. There was, indeed, the makings of a very pretty quarrel when the Letter arrived. It was about a mile long, and began to talk at once. "I'm from the Inventor," he said, and hope rose in the heart of each heated Principle. "It's really absurdly simple. All the Pilot has to do is to touch a button, and at his will, VARY the area of the Surface, the Angle of Incidence, and the Camber! And there you are--Maximum Climb or Maximum Speed as required! How does that suit you?" "That suits us very well," said the Surface, "but, excuse me asking, how is it done without apparatus increasing the Drift and the Weight out of all reason? You won't mind showing us your Calculations, Working Drawings, Stress Diagrams, etc., will you?" Said the Letter with dignity, "I come from an Inventor so brilliantly clever as to be far above the unimportant matters you mention. He is no common working man, sir! He leaves such things to Mechanics. The point is, you press a button and----" "Look here," said a Strut, rather pointedly, "where do you think you are going, anyway?" "Well," from the Letter, "as a matter of fact, I'm not addressed yet, but, of course, there's no doubt I shall reach the very highest quarters and absolutely revolutionize Flight when I get there." Said the Chalk, "I'll address you, if that's all you want; now drift along quickly!" And off went the Letter to The Technical Editor, "Daily Mauler," London. And a League was formed, and there were Directors with Fees, and several out-of-service Tin Hats, and the Man-who-takes-the-credit, and a fine fat Guinea-pig, and all the rest of them. And the Inventor paid his Tailor and had a Hair-Cut, and is now a recognized _Press_ Expert--but he is still waiting for those Mechanics! "I'm afraid," said the Slide-rule, who had been busy making those lightning-like automatic calculations for which he is so famous, "it's quite impossible to fully satisfy all of you, and it is perfectly plain to me that we shall have to effect a Compromise and sacrifice some of the Lift for Speed." Thud! What was that? Efficiency had fainted dead away! The last blow had been too much for her. And the Principles gathered mournfully round, but with the aid of the Propeller Slip[1] and a friendly lift from the Surface she was at length revived and regained a more normal aspect. Said the Stagger with a raffish air, "My dear young lady, I assure you that from the experiences of a varied career, I have learned that perfection is impossible, and I am sure the Designer will be quite satisfied if you become the Most Efficient Compromise." "Well, that sounds so common sense," sighed Efficiency, "I suppose it must be true, and if the Designer is satisfied, that's all I really care about. Now do let's get on with the job." [Illustration] So the Chalk drew a nice long slim body to hold the Engine and the tanks, etc., with room for the Pilot's and Passenger's seats, and placed it exactly in the middle of the Biplane. And he was careful to make its position such that the Centre of Gravity was a little in advance of the Centre of Lift, so that when the Engine was not running and there was consequently no Thrust, the Aeroplane should be "nose-heavy" just to the right degree, and so take up a natural glide to Earth--and this was to help the Pilot and relieve him of work and worry, should he find himself in a fog or a cloud. And so that this tendency to glide downwards should not be in evidence when the Engine was running and descent not desired, the Thrust was placed a little below the Centre of Drift or Resistance. In this way it would in a measure pull the nose of the Aeroplane up and counter-balance the "nose-heavy" tendency. And the Engine was so mounted that when the Propeller-Thrust was horizontal, which is its most efficient position, the Angle of Incidence and the Area of the surfaces were just sufficient to give a Lift a little in excess of the Weight. And the Camber was such that, as far as it was concerned, the Lift-Drift Ratio should be the best possible for that Angle of Incidence. And a beautifully simple under-carriage was added, the outstanding features of which were simplicity, strength, light-weight, and minimum drift. And, last of all, there was the Elevator, of which you will hear more by-and-by. And this is what it looked like then: [Illustration] And Efficiency, smiling, thought that it was not such a bad compromise after all, and that the Designer might well be satisfied. "Now," said she, "there's just one or two points I'm a bit hazy about. It appears that when the Propeller shaft is horizontal and so working in its most efficient attitude, I shall have a Lift from the Surfaces slightly in excess of the Weight. That means I shall ascend slightly, at the same time making nearly maximum speed for the power and thrust. Can't I do better than that?" "Yes, indeed," spoke up the Propeller, "though it means that I must assume a most undignified attitude, for helicopters[2] I never approved of. In order to ascend more quickly the Pilot will deflect the Elevator, which, by the way, you see hinged to the Tail. By that means he will force the whole Aeroplane to assume a greater Angle of Incidence. And with greater Angle, the Lift will increase, though I'm sorry to say the Drift will increase also. Owing to the greater Drift, the Speed through the air will lessen, and I'm afraid that won't be helpful to the Lift; but I shall now be pointing upwards, and besides overcoming the Drift in a forward direction, I shall be doing my best to haul the Aeroplane skywards. At a certain angle known as the Best Climbing Angle, we shall have our Maximum Margin of Lift, and I'm hoping that may be as much as almost a thousand feet altitude a minute." [Illustration: The angles shown above are only roughly approximate, as they vary with different types of aeroplanes.] "Then, if the Pilot is green, my chance will come," said the Maximum Angle of Incidence. "For if the Angle is increased over the Best Climbing Angle, the Drift will rush up; and the Speed, and with it the Lift, will, when my Angle is reached, drop to a point when the latter will be no more than the Weight. The Margin of Lift will have entirely disappeared, and there we shall be, staggering along at my tremendous angle, and only just maintaining horizontal flight." "And then with luck I'll get my chance," said the Drift. "If he is a bit worse than green, he'll perhaps still further increase the Angle. Then the Drift, largely increasing, the Speed, and consequently the Lift, will become still less, _i.e._, less than the Weight, and then--what price pancakes.[3] Eh?" "Thank you," from Efficiency, "that was all most informing. And now will you tell me, please, how the greatest Speed may be secured?" "Certainly, now it's my turn," piped the Minimum Angle of Incidence. "By means of the Elevator, the Pilot places the Aeroplane at my small Angle, at which the Lift only just equals the Weight, and, also, at which we shall make greater speed with no more Drift than before. Then we get our greatest Speed, just maintaining horizontal flight." "Yes; though I'm out of the horizontal and thrusting downwards," grumbled the Propeller, "and that's not efficient, though I suppose it's the best we can do until that Inventor fellow finds his Mechanics." "Thank you so much," said Efficiency. "I think I have now at any rate an idea of the Elementary Principles of Flight, and I don't know that I care to delve much deeper, for sums always give me a headache; but isn't there something about Stability and Control? Don't you think I ought to have a glimmering of them too?" "Well, I should smile," said a spruce Spar, who had come all the way from America. "And that, as the Lecturer says, 'will be the subject of our next lecture,' so be here again to-morrow, and you will be glad to hear that it will be distinctly more lively than the subject we have covered to-day." [Footnote 1: Propeller Slip: As the propeller screws through the air, the latter to a certain extent gives back to the thrust of the propeller blades, just as the shingle on the beach slips back as you ascend it. Such "give-back" is known as "slip," and anyone behind the propeller will feel the slip as a strong draught of air.] [Footnote 2: Helicopter: An air-screw revolving upon a vertical axis. If driven with sufficient power, it will lift vertically, but, having regard to the mechanical difficulties of such construction, it is a most inefficient way of securing lift compared with the arrangement of an inclined surface driven by a propeller revolving about a horizontal axis.] [Footnote 3: Pancakes: Pilot's slang for stalling an aeroplane and dropping like a pancake.] PART II THE PRINCIPLES, HAVING SETTLED THEIR DIFFERENCES, FINISH THE JOB Another day had passed, and the Flight Folk had again gathered together and were awaiting the arrival of Efficiency who, as usual, was rather late in making an appearance. The crowd was larger than ever, and among the newcomers some of the most important were the three Stabilities, named Directional, Longitudinal, and Lateral, with their assistants, the Rudder, Elevator, and Ailerons. There was Centrifugal Force, too, who would not sit still and created a most unfavourable impression, and Keel-Surface, the Dihedral Angle, and several other lesser fry. "Well," said Centrifugal Force, "I wish this Efficiency I've heard so much about would get a move on. Sitting still doesn't agree with me at all. Motion I believe in. There's nothing like motion--the more the better." "We are entirely opposed to that," objected the three Stabilities, all in a breath. "Unless it's in a perfectly straight line or a perfect circle. Nothing but perfectly straight lines or, upon occasion, perfect circles satisfy us, and we are strongly suspicious of your tendencies." "Well, we shall see what we shall see," said the Force darkly. "But who in the name of blue sky is this?" And in tripped Efficiency, in a beautifully "doped" dress of the latest fashionable shade of khaki-coloured fabric, a perfectly stream-lined bonnet, and a bewitching little Morane parasol,[4] smiling as usual, and airily exclaiming, "I'm so sorry I'm late, but you see the Designer's such a funny man. He objects to skin friction,[5] and insisted upon me changing my fabric for one of a smoother surface, and that delayed me. Dear me, there are a lot more of us to-day, aren't there? I think I had better meet one at a time." And turning to Directional Stability, she politely asked him what he preferred to do. "My purpose in life, miss," said he, "is to keep the Aeroplane on its course, and to achieve that there must be, in effect, more Keel-Surface behind the Vertical Turning Axis than there is in front of it." [Illustration] Efficiency looking a little puzzled, he added: "Just like a weathercock, and by Keel-Surface I mean everything you can see when you view the Aeroplane from the side of it--the sides of the body, struts, wires, etc." "Oh, now I begin to see light," said she; "but just exactly how does it work?" "I'll answer that," said Momentum. "When perhaps by a gust of air the Aeroplane is blown out of its course and points in another direction, it doesn't immediately fly off on that new course. I'm so strong I pull it off the new course to a certain extent, and towards the direction of the old course. And so it travels, as long as my strength lasts, in a more or less sideways position." "Then," said the Keel-Surface, "I get a pressure of air all on one side, and as there is, in effect, most of me towards the tail, the latter gets pressed sideways, and the Aeroplane thus tends to assume its first position and course." "I see," said Efficiency, and, daintily holding the Chalk, she approached the Blackboard. "Is this what you mean?" "Yes, that's right enough," said the Keel-Surface, "and you might remember, too, that I always make the Aeroplane nose into the gusts rather than away from them." "If that was not the case," broke in Lateral Stability, and affecting the fashionable Flying Corps stammer, "it would be a h-h-h-o-r-rible affair! If there were too much Keel-Surface in front, then that gust would blow the Aeroplane round the other way a very considerable distance. And the right-hand Surface being on the outside of the turn would have more speed, and consequently more Lift, than the Surface on the other side. That means a greater proportion of the Lift on that side, and before you could say Warp to the Ailerons over the Aeroplane would go--probable result a bad side-slip" (see illustration A, over-leaf). "And what can the Pilot do to save such a situation as that?" said Efficiency. "Well," replied Lateral Stability, "he will try to turn the Aeroplane sideways and back to an even keel by means of warping the Ailerons or little wings which are hinged on to the Wing-tips, and about which you will hear more later on; but if the side-slip is very bad he may not be able to right the Aeroplane by means of the Ailerons, and then the only thing for him to do is to use the Rudder and to turn the nose of the Aeroplane down and head-on to the direction of motion. The Aeroplane will then be meeting the air in the direction it is designed to do so, and the Surfaces and also the controls (the Rudder, Ailerons, and Elevator) will be working efficiently; but its attitude relative to the earth will probably be more or less upside-down, for the action of turning the Aeroplane's nose down results, as you will see by the illustration B, in the right wing, which is on the outside of the circle, travelling through the air with greater speed than the left-hand wing. More Speed means more Lift, so that results in overturning the Aeroplane still more; but now it is, at any rate, meeting the air as it is designed to meet it, and everything is working properly. It is then only necessary to warp the Elevator, as shown in illustration C, in order to bring the Aeroplane into a proper attitude relative to the earth." [Illustration] "Ah!" said the Rudder, looking wise, "it's in a case like that when I become the Elevator and the Elevator becomes me." "That's absurd nonsense," said the Blackboard, "due to looseness of thought and expression." "Well," replied the Rudder, "when the Aeroplane is in position A and I am used, then I depress or _elevate_ the nose of the machine; and, if the Elevator is used, then it turns the Aeroplane to right or left, which is normally my function. Surely our _rôles_ have changed one with the other, and I'm then the Elevator and the Elevator is me!" [Illustration] Said Lateral Stability to the Rudder, "That's altogether the wrong way of looking at it, though I admit"--and this rather sarcastically--"that the way you put it sounds rather fine when you are talking of your experiences in the air to those 'interested in aviation' but knowing little about it; but it won't go down here! You are a Controlling Surface designed to turn the Aeroplane about a certain axis of the machine, and the Elevator is a Controlling Surface designed to turn the Aeroplane about another axis. Those are your respective jobs, and you can't possibly change them about. Such talk only leads to confusion, and I hope we shall hear no more of it." "Thanks," said Efficiency to Lateral Stability. "And now, please, will you explain your duties?" "My duty is to keep the Aeroplane horizontal from Wing-tip to Wing-tip. First of all, I sometimes arrange with the Rigger to _wash-out_, that is decrease, the Angle of Incidence on one side of the Aeroplane, and to effect the reverse condition, if it is not too much trouble, on the other side." "But," objected Efficiency, "the Lift varies with the Angle of Incidence, and surely such a condition will result in one side of the Aeroplane lifting more than the other side?" "That's all right," said the Propeller, "it's meant to off-set the tendency of the Aeroplane to turn over sideways in the opposite direction to which I revolve." "That's quite clear, though rather unexpected; but how do you counteract the effect of the gusts when they try to overturn the Aeroplane sideways?" said she, turning to Lateral Stability again. "Well," he replied, rather miserably, "I'm not nearly so perfect as the Longitudinal and Directional Stabilities. The Dihedral Angle--that is, the upward inclination of the Surfaces towards their wing-tips--does what it can for me, but, in my opinion, it's a more or less futile effort. The Blackboard will show you the argument." And he at once showed them two Surfaces, each set at a Dihedral Angle like this: [Illustration: H.E., Horizontal equivalent.] "Please imagine," said the Blackboard, "that the top =V= is the front view of a Surface flying towards you. Now if a gust blows it into the position of the lower =V= you see that the horizontal equivalent of the Surface on one side becomes larger, and on the other side it becomes smaller. That results in more lift on the lower side and less on the higher side, and if the =V= is large enough it should produce such a difference in the lift of one side to the other as to quickly turn the Aeroplane back to its former and normal position." "Yes," said the Dihedral Angle, "that's what would happen if they would only make me large enough; but they won't do it because it would too greatly decrease the total horizontal equivalent, and therefore the Lift, and incidentally it would, as Aeroplanes are built to-day, produce an excess of Keel Surface above the turning axis, and that in itself would spoil the Lateral Stability. The Keel Surface should be equally divided above and below the longitudinal turning axis (upon which the Aeroplane rolls sideways), or the side upon which there is an excess will get blown over by the gusts. It strikes me that my future isn't very promising, and about my only chance is when the Junior Draughtsman makes a mistake, as he did the other day. And just think of it, they call him a Designer now that he's got a job at the Factory! What did he do? Why, he calculated the weights wrong and got the Centre of Gravity too high, and they didn't discover it until the machine was built. Then all they could do was to give me a larger Angle. That dropped the bottom of the =V= lower down, and as that's the centre of the machine, where all the Weight is, of course that put the Centre of Gravity in its right place. But now there is too much Keel Surface above, and the whole thing's a Bad Compromise, not at all like Our Efficiency." And Efficiency, blushing very prettily at the compliment, then asked, "And how does the Centre of Gravity affect matters?" "That's easy," said Grandfather Gravity. "I'm so heavy that if I am too low down I act like a pendulum and cause the Aeroplane to roll about sideways, and if I am too high I'm like a stick balanced on your finger, and then if I'm disturbed, over I go and the Aeroplane with me; and, in addition to that, there are the tricks I play with the Aeroplane when it's banked up,[6] _i.e._, tilted sideways for a turn, and Centrifugal Force sets me going the way I'm not wanted to go. No; I get on best with Lateral Stability when my Centre is right on the centre of drift, or, at any rate, not much below it." And with that he settled back into the Lecturer's Chair and went sound asleep again, for he was so very, very old, in fact the father of all the Principles. And the Blackboard had been busy, and now showed them a picture of the Aeroplane as far as they knew it, and you will see that there is a slight Dihedral Angle, and also, fixed to the tail, a vertical Keel Surface or _fin_, as is very often the case in order to ensure the greater effect of such surface being behind the vertical turning axis. [Illustration] But Efficiency, growing rather critical with her newly gained knowledge, cried out: "But where's the horizontal Tail Surface? It doesn't look right like that!" "This is when I have the pleasure of meeting you, my dear," said Longitudinal Stability. "Here's the Tail Surface," he said, "and in order to help me it must be set _in effect_ at a much less Angle of Incidence than the Main Surface. To explain we must trouble the Blackboard again," and this was his effort: [Illustration] "I have tried to make that as clear as possible," he said. "It may appear a bit complicated at first, but if you will take the trouble to look at it for a minute you will find it quite simple. A is the normal and proper direction of motion of the Aeroplane, but, owing to a gust of air, it takes up the new nose-down position. Owing to Momentum, however, it does not fly straight along in that direction, but moves more or less in the direction B, which is the resultant of the two forces, Momentum and Thrust. And so you will note that the Angle of Incidence, which is the inclination of the Surfaces to the Direction of Motion, has decreased, and of course the Lift decreases with it. You will also see, and this is the point, that the Tail Surface has lost a higher proportion of its Angle, and consequently its Lift, than has the Main Surface. Then, such being the case, the Tail must fall and the Aeroplane assume its normal position again, though probably at a slightly lower altitude." "I'm afraid I'm very stupid," said Efficiency, "but please tell me why you lay stress upon the words '_in effect_.'" "Ah! I was wondering if you would spot that," he replied. "And there is a very good reason for it. You see, in some Aeroplanes the Tail Surface may be actually set at the same Angle on the machine as the Main Surface, but owing to the air being deflected downwards by the front Main Surface it meets the Tail Surface at a lesser angle, and indeed in some cases at no angle at all. The Tail is then for its surface getting less Lift than the Main Surface, although set at the same angle on the machine. It may then be said to have _in effect_ a less Angle of Incidence. I'll just show you on the Blackboard." [Illustration] "And now," said Efficiency, "I have only to meet the Ailerons and the Rudder, haven't I?" "Here we are," replied the Ailerons, or little wings. "Please hinge us on to the back of the Main Surfaces, one of us at each Wing-tip, and join us up to the Pilot's joystick by means of the control cables. When the Pilot wishes to tilt the Aeroplane sideways, he will move the stick and depress us upon one side, thus giving us a larger Angle of Incidence and so creating more Lift on that side of the Aeroplane; and, by means of a cable connecting us with the Ailerons on the other side of the Aeroplane, we shall, as we are depressed, pull them up and give them a reverse or negative Angle of Incidence, and that side will then get a reverse Lift or downward thrust, and so we are able to tilt the Aeroplane sideways. "And we work best when the Angle of Incidence of the Surface in front of us is very small, for which reason it is sometimes decreased or _washed-out_ towards the Wing-tips. The reason of that is that by the time the air reaches us it has been deflected downwards--the greater the Angle of Incidence the more it is driven downwards--and in order for us to secure a Reaction from it, we have to take such a large Angle of Incidence that we produce a poor proportion of Lift to Drift; but the smaller the Angle of the Surface in front of us the less the air is deflected downwards, and consequently the less Angle is required of us, and the better our proportion of Lift to Drift, which, of course, makes us much more effective Controls." [Illustration: "Wash out" on both sides.] "Yes," said the Lateral and Directional Stabilities in one voice, "that's so, and the wash-out helps us also, for then the Surfaces towards their Wing-tips have less Drift or 'Head-Resistance,' and consequently the gusts will affect them and us less; but such decreased Angle of Incidence means decreased Lift as well as Drift, and the Designer does not always care to pay the price." "Well," said the Ailerons, "if it's not done it will mean more work for the Rudder, and that won't please the Pilot." "Whatever do you mean?" asked Efficiency. "What can the Rudder have to do with you?" "It's like this," they replied: "when we are deflected downwards we gain a larger Angle of Incidence and also enter an area of compressed air, and so produce more Drift than those of us on the other side of the Aeroplane, which are deflected upwards into an area of rarefied air due to the _suction_ effect (though that term is not academically correct) on the top of the Surface. If there is more Drift, _i.e._, Resistance, on one side of the Aeroplane than on the other side, then of course it will turn off its course, and if that difference in Drift is serious, as it will very likely be if there is no wash-out, then it will mean a good deal of work for the Rudder in keeping the Aeroplane on its course, besides creating extra Drift in doing so." "I think, then," said Efficiency, "I should prefer to have that wash-out,[7] and my friend the Designer is so clever at producing strength of construction for light weight, I'm pretty sure he won't mind paying the price in Lift. And now let me see if I can sketch the completed Aeroplane." [Illustration] "Well, I hope that's all as it should be," she concluded, "for to-morrow the Great Test in the air is due." [Footnote 4: Morane parasol: A type of Morane monoplane in which the lifting surfaces are raised above the pilot in order to afford him a good view of the earth.] [Footnote 5: Skin friction is that part of the drift due to the friction of the air with roughness upon the surface of the aeroplane.] [Footnote 6: Banking: When an aeroplane is turned to the left or the right the centrifugal force of its momentum causes it to skid sideways and outwards away from the centre of the turn. To minimize such action the pilot banks, _i.e._, tilts, the aeroplane sideways in order to oppose the underside of the planes to the air. The aeroplane will not then skid outwards beyond the slight skid necessary to secure a sufficient pressure of air to balance the centrifugal force.] [Footnote 7: An explanation of the way in which the wash-out is combined with a wash-in to offset propeller torque will be found on p. 82.] PART III THE GREAT TEST It is five o'clock of a fine calm morning, when the Aeroplane is wheeled out of its shed on to the greensward of the Military Aerodrome. There is every promise of a good flying day, and, although the sun has not yet risen, it is light enough to discern the motionless layer of fleecy clouds some five thousand feet high, and far, far above that a few filmy mottled streaks of vapour. Just the kind of morning beloved of pilots. A brand new, rakish, up-to-date machine it is, of highly polished, beautifully finished wood, fabric as tight as a drum, polished metal, and every part so perfectly "stream-lined" to minimize drift, which is the resistance of the air to the passage of the machine, that to the veriest tyro the remark of the Pilot is obviously justified. "Clean looking 'bus, looks almost alive and impatient to be off. Ought to have a turn for speed with those lines." "Yes," replies the Flight-Commander, "it's the latest of its type and looks a beauty. Give it a good test. A special report is required on this machine." The A.M.'s[8] have now placed the Aeroplane in position facing the gentle air that is just beginning to make itself evident; the engine Fitter, having made sure of a sufficiency of oil and petrol in the tanks, is standing by the Propeller; the Rigger, satisfied with a job well done, is critically "vetting" the machine by eye; four A.M.'s are at their posts, ready to hold the Aeroplane from jumping the blocks which have been placed in front of the wheels; and the Flight-Sergeant is awaiting the Pilot's orders. As the Pilot approaches the Aeroplane the Rigger springs to attention and reports, "All correct, sir," but the Fitter does not this morning report the condition of the Engine, for well he knows that this pilot always personally looks after the preliminary engine test. The latter, in leathern kit, warm flying boots and goggled, climbs into his seat, and now, even more than before, has the Aeroplane an almost living appearance, as if straining to be off and away. First he moves the Controls to see that everything is clear, for sometimes when the Aeroplane is on the ground the control lever or "joy-stick" is lashed fast to prevent the wind from blowing the controlling surfaces about and possibly damaging them. The air of this early dawn is distinctly chilly, and the A.M.'s are beginning to stamp their cold feet upon the dewy grass, but very careful and circumspect is the Pilot, as he mutters to himself, "Don't worry and flurry, or you'll die in a hurry." At last he fumbles for his safety belt, but with a start remembers the Pitot Air Speed Indicator, and, adjusting it to zero, smiles as he hears the Pitot-head's gruff voice, "Well, I should think so, twenty miles an hour I was registering. That's likely to cause a green pilot to stall the Aeroplane. Pancake, they call it." And the Pilot, who is an old hand and has learned a lot of things in the air that mere earth-dwellers know nothing about, distinctly heard the Pitot Tube, whose mouth is open to the air to receive its pressure, stammer, "Oh Lor! I've got an earwig already--hope to goodness the Rigger blows me out when I come down--and this morning air simply fills me with moisture; I'll never keep the Liquid steady in the Gauge. I'm not sure of my rubber connections either." "Oh, shut up!" cry all the Wires in unison, "haven't we got our troubles too? We're in the most horrible state of tension. It's simply murdering our Factor of Safety, and how we can possibly stand it when we get the Lift only the Designer knows." "That's all right," squeak all the little Wire loops, "we're that accommodating, we're sure to elongate a bit and so relieve your tension." For the whole Aeroplane is braced together with innumerable wires, many of which are at their ends bent over in the form of loops in order to connect with the metal fittings on the spars and elsewhere--a cheap and easy way of making connection. "Elongate, you little devils, would you?" fairly shout the Angles of Incidence, Dihedral and Stagger, amid a chorus of groans from all parts of the Aeroplane. "What's going to happen to us then? How are we going to keep our adjustments upon which good flying depends?" "Butt us and screw us,"[9] wail the Wires. "Butt us and screw us, and death to the Loops. That's what we sang to the Designer, but he only looked sad and scowled at the Directors." "And who on earth are they?" asked the Loops, trembling for their troublesome little lives. "On earth indeed," sniffed Efficiency, who had not spoken before, having been rendered rather shy by being badly compromised in the Drawing Office. "I'd like to get some of them up between Heaven and Earth, I would. I'd give 'em something to think of besides their Debits and Credits--but all the same the Designer will get his way in the end. I'm his Best Girl, you know, and if we could only get rid of the Directors, the little Tin god, and the Man-who-takes-the-credit, we should be quite happy." Then she abruptly subsides, feeling that perhaps the less said the better until she has made a reputation in the Air. The matter of that Compromise still rankled, and indeed it does seem hardly fit that a bold bad Tin god should flirt with Efficiency. You see there was a little Tin god, and he said "Boom, Boom, BOOM! Nonsense! It MUST be done," and things like that in a very loud voice, and the Designer tore his hair and was furious, but the Directors, who were thinking of nothing but Orders and Dividends, had the whip-hand of _him_, and so there you are, and so poor beautiful Miss Efficiency was compromised. All this time the Pilot is carefully buckling his belt and making himself perfectly easy and comfortable, as all good pilots do. As he straightens himself up from a careful inspection of the Deviation Curve[10] of the Compass and takes command of the Controls, the Throttle and the Ignition, the voices grow fainter and fainter until there is nothing but a trembling of the Lift and Drift wires to indicate to his understanding eye their state of tension in expectancy of the Great Test. "Petrol on?" shouts the Fitter to the Pilot. "Petrol on," replies the Pilot. "Ignition off?" "Ignition off." Round goes the Propeller, the Engine sucking in the Petrol Vapour with satisfied gulps. And then-- "Contact?" from the Fitter. "Contact," says the Pilot. Now one swing of the Propeller by the Fitter, and the Engine is awake and working. Slowly at first though, and in a weak voice demanding, "Not too much Throttle, please. I'm very cold and mustn't run fast until my Oil has thinned and is circulating freely. Three minutes slowly, as you love me, Pilot." Faster and faster turn the Engine and Propeller, and the Aeroplane, trembling in all its parts, strains to jump the blocks and be off. Carefully the Pilot listens to what the Engine Revolution Indicator says. At last, "Steady at 1,500 revs. and I'll pick up the rest in the Air." Then does he throttle down the Engine, carefully putting the lever back to the last notch to make sure that in such position the throttle is still sufficiently open for the Engine to continue working, as otherwise it might lead to him "losing" his Engine in the air when throttling down the power for descent. Then, giving the official signal, he sees the blocks removed from the wheels, and the Flight-Sergeant saluting he knows that all is clear to ascend. One more signal, and all the A.M.'s run clear of the Aeroplane. Then gently, gently mind you, with none of the "crashing on" bad Pilots think so fine, he opens the Throttle and, the Propeller Thrust overcoming its enemy the Drift, the Aeroplane moves forward. "Ah!" says the Wind-screen, "that's Discipline, that is. Through my little Triplex window I see most things, and don't I just know that poor discipline always results in poor work in the air, and don't you forget it." "Discipline is it?" complains the Under-carriage, as its wheels roll swiftly over the rather rough ground. "I'm _bump_ getting it, and _bump_, _bump_, all I want, _bang_, _bump_, _rattle_, too!" But, as the Lift increases with the Speed, the complaints of the Under-carriage are stilled, and then, the friendly Lift becoming greater than the Weight, the Aeroplane swiftly and easily takes to the air. Below is left the Earth with all its bumps and troubles. Up into the clean clear Air moves with incredible speed and steadiness this triumph of the Designer, the result of how much mental effort, imagination, trials and errors, failures and successes, and many a life lost in high endeavour. Now is the mighty voice of the Engine heard as he turns the Propeller nine hundred times a minute. Now does the Thrust fight the Drift for all it's worth, and the Air Speed Indicator gasps with delight "One hundred miles an hour!" And now does the burden of work fall upon the Lift and Drift Wires, and they scream to the Turnbuckles whose business it is to hold them in tension, "This is the limit! the Limit! THE LIMIT! Release us, if only a quarter turn." But the Turnbuckles are locked too fast to turn their eyes or utter a word. Only the Locking Wires thus: "Ha! ha! the Rigger knew his job. He knew the trick, and there's no release here." For an expert rigger will always use the locking wire in such a way as to oppose the slightest tendency of the turnbuckle to unscrew. The other kind of rigger will often use the wire in such a way as to allow the turnbuckle, to the "eyes" of which the wires are attached, to unscrew a quarter of a turn or more, with the result that the correct adjustment of the wires may be lost; and upon their fine adjustment much depends. And the Struts and the Spars groan in compression and pray to keep straight, for once "out of truth" there is, in addition to possible collapse, the certainty that in bending they will throw many wires out of adjustment. And the Fabric's quite mixed in its mind, and ejaculates, "Now, who would have thought I got more Lift from the top of the Surface than its bottom?" And then truculently to the Distance Pieces, which run from rib to rib, "Just keep the Ribs from rolling, will you? or you'll see me strip. I'm an Irishman, I am, and if my coat comes off---- Yes, Irish, I said. I used to come from Egypt, but I've got naturalized since the War began." Then the Air Speed Indicator catches the eye of the Pilot. "Good enough," he says as he gently deflects the Elevator and points the nose of the Aeroplane upwards in search of the elusive Best Climbing Angle. "Ha! ha!" shouts the Drift, growing stronger with the increased Angle of Incidence. "Ha! ha!" he laughs to the Thrust. "Now I've got you. Now who's Master?" And the Propeller shrieks hysterically, "Oh! look at me. I'm a helicopter. That's not fair. Where's Efficiency?" And she can only sadly reply, "Yes, indeed, but you see we're a Compromise." And the Drift has hopes of reaching the Maximum Angle of Incidence and vanquishing the Thrust and the Lift. And he grows very bold as he strangles the Thrust; but the situation is saved by the Propeller, who is now bravely helicopting skywards, somewhat to the chagrin of Efficiency. "Much ado about nothing," quotes the Aeroplane learnedly. "Compromise or not, I'm climbing a thousand feet a minute. Ask the Altimeter. He'll confirm it." And so indeed it was. The vacuum box of the Altimeter was steadily expanding under the decreased pressure of the rarefied air, and by means of its little levers and its wonderful chain no larger than a hair it was moving the needle round the gauge and indicating the ascent at the rate of a thousand feet a minute. And lo! the Aeroplane has almost reached the clouds! But what's this? A sudden gust, and down sinks one wing and up goes the other. "Oh, my Horizontal Equivalent!" despairingly call the Planes; "it's eloping with the Lift, and what in the name of Gravity will happen? Surely there was enough scandal in the Factory without this, too!" For the lift varies with the horizontal equivalent of the planes, so that if the aeroplane tilts sideways beyond a certain angle, the lift becomes less than the weight of the machine, which must then fall. A fall in such a position is known as a "side-slip." But the ever-watchful Pilot instantly depresses one aileron, elevating the other, with just a touch of the rudder to keep on the course, and the Planes welcome back their precious Lift as the Aeroplane flicks back to its normal position. "Bit bumpy here under these clouds," is all the Pilot says as he heads for a gap between them, and the next minute the Aeroplane shoots up into a new world of space. "My eye!" ejaculates the Wind-screen, "talk about a view!" And indeed mere words will always fail to express the wonder of it. Six thousand feet up now, and look! The sun is rising quicker than ever mortal on earth witnessed its ascent. Far below is Mother Earth, wrapt in mists and deep blue shadows, and far above are those light, filmy, ethereal clouds now faintly tinged with pink. And all about great mountains of cloud, lazily floating in space. The sun rises and they take on all colours, blending one with the other, from dazzling white to crimson and deep violet-blue. Lakes and rivers here and there in the enormous expanse of country below refract the level rays of the sun and, like so many immense diamonds, send dazzling shafts of light far upwards. The tops of the hills now laugh to the light of the sun, but the valleys are still mysterious dark blue caverns, crowned with white filmy lace-like streaks of vapour. And withal the increasing sense with altitude of vast, clean, silent solitudes of space. Lives there the man who can adequately describe this Wonder? "Never," says the Pilot, who has seen it many times, but to whom it is ever new and more wonderful. Up, up, up, and still up, unfalteringly speeds the Pilot and his mount. Sweet the drone of the Engine and steady the Thrust as the Propeller exultingly battles with the Drift. And look! What is that bright silver streak all along the horizon? It puzzled the Pilot when first he saw it, but now he knows it for the Sea, full fifty miles away! And on his right is the brightness of the morn and the smiling Earth unveiling itself to the ardent rays of the Sun; and on his left, so high is he, there is yet black night, hiding innumerable Cities, Towns, villages, and all those places where soon teeming multitudes of men shall awake, and by their unceasing toil and the spirit within them produce marvels of which the Aeroplane is but the harbinger. And the Pilot's soul is refreshed, and his vision, now exalted, sees the Earth a very garden, even as it appears at that height, with discord banished and a happy time come, when the Designer shall have at last captured Efficiency, and the Man-who-takes-the-credit is he who has earned it, and when kisses are the only things that go by favour. Now the Pilot anxiously scans the Barograph, which is an instrument much the same as the Altimeter; but in this case the expansion of the vacuum box causes a pen to trace a line upon a roll of paper. This paper is made by clockwork to pass over the point of the pen, and so a curved line is made which accurately registers the speed of the ascent in feet per minute. No longer is the ascent at the rate of a thousand feet a minute, and the Propeller complains to the Engine, "I'm losing my Revs. and the Thrust. Buck up with the Power, for the Lift is decreasing, though the Weight remains much the same." Quoth the Engine: "I strangle for Air. A certain proportion, and that of right density, I must have to one part of Petrol, in order to give me full power and compression, and here at an altitude of ten thousand feet the Air is only two-thirds as dense as at sea-level. Oh, where is he who will invent a contrivance to keep me supplied with air of right density and quality? It should not be impossible within certain limits." "We fully agree," said the dying Power and Thrust. "Only maintain Us and you shall be surprised at the result. For our enemy Drift _decreases in respect of distance with the increase of altitude and rarity of air_, and there is no limit to the speed through space if only our strength remains. And with oxygen for pilot and passengers and a steeper pitch[11] for the Propeller we may then circle the Earth in a day!" Ah, Reader, smile not unbelievingly, as you smiled but a few years past. There may be greater wonders yet. Consider that as the speed increases, so does the momentum or stored-up force in the mass of the aeroplane become terrific. And, bearing that in mind, remember that with altitude _gravity decreases_. There may yet be literally other worlds to conquer.[12] Now at fifteen thousand feet the conditions are chilly and rare, and the Pilot, with thoughts of breakfast far below, exclaims, "High enough! I had better get on with the Test." And then, as he depresses the Elevator, the Aeroplane with relief assumes its normal horizontal position. Then, almost closing the Throttle, the Thrust dies away. Now, the nose of the Aeroplane should sink of its own volition, and the craft glide downward at flying speed, which is in this case a hundred miles an hour. That is what should happen if the Designer has carefully calculated the weight of every part and arranged for the centre of gravity to be just the right distance in front of the centre of lift. Thus is the Aeroplane "nose-heavy" as a glider, and just so to a degree ensuring a speed of glide equal to its flying speed. And the Air Speed Indicator is steady at one hundred miles an hour, and "That's all right!" exclaims the Pilot. "And very useful, too, in a fog or a cloud," he reflects, for then he can safely leave the angle of the glide to itself, and give all his attention, and he will need it all, to keeping the Aeroplane horizontal from wing-tip to wing-tip, and to keeping it straight on its course. The latter he will manage with the rudder, controlled by his feet, and the Compass will tell him whether a straight course is kept. The former he will control by the ailerons, or little wings hinged to the tips of the planes, and the bubble in the Inclinometer in front of him must be kept in the middle. A pilot, being only human, may be able to do two things at once, but three is a tall order, so was this pilot relieved to find the Design not at fault and his craft a "natural glider." To correct this nose-heavy tendency when the Engine is running, and descent not required, the centre of Thrust is arranged to be a little below the centre of Drift or Resistance, and thus acts as a counter-balance. But what is this stream of bad language from the Exhaust Pipe, accompanied by gouts of smoke and vapour? The engine, now revolving at no more than one-tenth its normal speed, has upset the proportion of petrol to air, and combustion is taking place intermittently or in the Exhaust Pipe, where it has no business to be. "Crash, Bang, Rattle----!----!----!" and worse than that, yells the Exhaust, and the Aeroplane, who is a gentleman and not a box kite,[13] remonstrates with the severity of a Senior Officer. "See the Medical Officer, you young Hun. Go and see a doctor. Vocal diarrhoea, that's your complaint, and a very nasty one too. Bad form, bad for discipline, and a nuisance in the Mess. What's your Regiment? Special Reserve, you say? Humph! Sounds like Secondhand Bicycle Trade to me!" Now the pilot decides to change the straight gliding descent to a spiral one, and, obedient to the Rudder, the Aeroplane turns to the left. But the Momentum (two tons at 100 miles per hour is no small affair) heavily resents this change of direction, and tries its level best to prevent it and to pull the machine sideways and outwards from its spiral course--that is, to make it "side-skid" outwards. But the Pilot deflects the Ailerons and "banks" up the planes to the correct angle, and, the Aeroplane skidding sideways and outwards, the lower surfaces of the planes press up against the air until the pressure equals the centrifugal force of the Momentum, and the Aeroplane spirals steadily downwards. Down, down, down, and the air grows denser, and the Pilot gulps largely, filling his lungs with the heavier air to counteract the increasing pressure from without. Down through a gap in the clouds, and the Aerodrome springs into view, appearing no larger than a saucer, and the Pilot, having by now got the "feel" of the Controls, proceeds to put the Aeroplane through its paces. First at its Maximum Angle, staggering along tail-down and just maintaining horizontal flight; then a dive at far over flying speed, finishing with a perfect loop; then sharp turns with attendant vertical "banks," and then a wonderful switchback flight, speeding down at a hundred and fifty miles an hour with short, exhilarating ascents at the rate of two thousand feet a minute! All the parts are now working well together. Such wires as were before in undue tension have secured relief by slightly elongating their loops, and each one is now doing its bit, and all are sharing the burden of work together. The Struts and the Spars, which felt so awkward at first, have bedded themselves in their sockets, and are taking the compression stresses uncomplainingly. The Control Cables of twisted wire, a bit tight before, have slightly lengthened by perhaps the eighth of an inch, and, the Controls instantly responding to the delicate touch of the Pilot, the Aeroplane, at the will of its Master, darts this way and that way, dives, loops, spirals, and at last, in one long, magnificent glide, lands gently in front of its shed. "Well, what result?" calls the Flight-Commander to the Pilot. "A hundred miles an hour and a thousand feet a minute," he briefly replies. "And a very good result too," says the Aeroplane, complacently, as he is carefully wheeled into his shed. * * * * * That is the way Aeroplanes speak to those who love them and understand them. Lots of Pilots know all about it, and can spin you wonderful yarns, much better than this one, if you catch them in a confidential mood--on leave, for instance, and after a good dinner. [Footnote 8: A.M.'s: Air Mechanics.] [Footnote 9: Butt means to thicken at the end. Screw means to machine a thread on the butt-end of the wire, and in this way the wire can make connection with the desired place by being screwed into a metal fitting, thus eliminating the disadvantage of the unsatisfactory loop.] [Footnote 10: Deviation Curve: A curved line indicating any errors in the compass.] [Footnote 11: A propeller screws through the air, and the distance it advances during one revolution, supposing the air to be solid, is known as the pitch. The pitch, which depends upon the angle of the propeller blades, must be equal to the speed of the aeroplane, plus the slip, and if, on account of the rarity of the air, the speed of the aeroplane increases, then the angle and pitch should be correspondingly increased. Propellers with a pitch capable of being varied by the pilot are the dream of propeller designers. For explanation of "slip" see Chapter IV. on propellers.] [Footnote 12: Getting out of my depth? Invading the realms of fancy? Well, perhaps so, but at any rate it is possible that extraordinary speed through space may be secured if means are found to maintain the impulse of the engine and the thrust-drift efficiency of the propeller at great altitude.] [Footnote 13: Box-kite. The first crude form of biplane.] PART IV 'CROSS COUNTRY The Aeroplane had been designed and built, and tested in the air, and now it stood on the Aerodrome ready for its first 'cross-country flight. It had run the gauntlet of pseudo-designers, crank inventors, press "experts," and politicians; of manufacturers keen on cheap work and large profits; of poor pilots who had funked it, and good pilots who had expected too much of it. Thousands of pounds had been wasted on it, many had gone bankrupt over it, and others it had provided with safe fat jobs. Somehow, and despite every conceivable obstacle, it had managed to muddle through, and now it was ready for its work. It was not perfect, for there were fifty different ways in which it might be improved, some of them shamefully obvious. But it was fairly sound mechanically, had a little inherent stability, was easily controlled, could climb a thousand feet a minute, and its speed was a hundred miles an hour. In short, quite a creditable machine, though of course the right man had not got the credit. It is rough, unsettled weather with a thirty mile an hour wind on the ground, and that means fifty more or less aloft. Lots of clouds at different altitudes to bother the Pilot, and the air none too clear for the observation of landmarks. As the Pilot and Observer approach the Aeroplane the former is clearly not in the best of tempers. "It's rotten luck," he is saying, "a blank shame that I should have to take this blessed 'bus and join X Reserve Squadron, stationed a hundred and fifty miles from anywhere; and just as I have licked my Flight into shape. Now some slack blighter will, I suppose, command it and get the credit of all my work!" "Shut up, you grouser," said the Observer. "Do you think you're the only one with troubles? Haven't I been through it too? Oh! I know all about it! You're from the Special Reserve and your C.O. doesn't like your style of beauty, and you won't lick his boots, and you were a bit of a technical knut in civil life, but now you've jolly well got to know less than those senior to you. Well! It's a very good experience for most of us. Perhaps conceit won't be at quite such a premium after this war. And what's the use of grousing? That never helped anyone. So buck up, old chap. Your day will come yet. Here's our machine, and I must say it looks a beauty!" And, as the Pilot approaches the Aeroplane, his face brightens and he soon forgets his troubles as he critically inspects the craft which is to transport him and the Observer over the hills and far away. Turning to the Flight-Sergeant he inquires, "Tanks full of petrol and oil?" "Yes, sir," he replies, "and everything else all correct. Propeller, engine, and body covers on board, sir; tool kit checked over and in the locker; engine and Aeroplane logbooks written up, signed, and under your seat; engine revs. up to mark, and all the control cables in perfect condition and tension." "Very good," said the Pilot; and then turning to the Observer, "Before we start you had better have a look at the course I have mapped out (see p. 40). "A is where we stand and we have to reach B, a hundred and fifty miles due North. I judge that, at the altitude we shall fly, there will be an East wind, for although it is not quite East on the ground it is probably about twenty degrees different aloft, the wind usually moving round clockways to about that extent. I think that it is blowing at the rate of about fifty miles an hour, and I therefore take a line on the map to C, fifty miles due West of A. The Aeroplane's speed is a hundred miles an hour, and so I take a line of one hundred miles from C to D. Our compass course will then be in the direction A--E, which is always a line parallel to C--D. That is, to be exact, it will be fourteen degrees off the C--D course, as, in this part of the globe, there is that much difference between the North and South lines on the map and the magnetic North to which the compass needle points. If the compass has an error, as it may have of a few degrees, that, too, must be taken into account, and the deviation or error curve on the dashboard will indicate it. [Illustration: A--B, 150 miles, A--C, 50 miles; direction and miles per hour of wind. C--D, 100 miles; airspeed of aeroplane. A--D, Distance covered by aeroplane in one hour. A--E, Compass course.] "The Aeroplane will then always be pointing in a direction parallel to A--E, but, owing to the side wind, it will be actually travelling over the course A--B, though in a rather sideways attitude to that course. "The distance we shall travel over the A--B course in one hour is A--D. That is nearly eighty-seven miles, so we ought to accomplish our journey of a hundred and fifty miles in about one and three-quarter hours. "I hope that's quite clear to you. It's a very simple way of calculating the compass course, and I always do it like that." "Yes, that's plain enough. You have drafted what engineers call 'a parallelogram of forces'; but suppose you have miscalculated the velocity of the wind, or that it should change in velocity or direction?" "Well, that of course will more or less alter matters," replies the Pilot. "But there are any number of good landmarks such as lakes, rivers, towns, and railway lines. They will help to keep us on the right course, and the compass will, at any rate, prevent us from going far astray when between them." "Well, we'd better be off, old chap. Hop aboard." This from the Observer as he climbs into the front seat from which he will command a good view over the lower plane; and the Pilot takes his place in the rear seat, and, after making himself perfectly comfortable, fixing his safety belt, and moving the control levers to make sure that they are working freely, he gives the signal to the Engine Fitter to turn the propeller and so start the engine. Round buzzes the Propeller, and the Pilot, giving the official signal, the Aeroplane is released and rolls swiftly over the ground in the teeth of the gusty wind. In less than fifty yards it takes to the air and begins to climb rapidly upwards, but how different are the conditions to the calm morning of yesterday! If the air were visible it would be seen to be acting in the most extraordinary manner; crazily swirling, lifting and dropping, gusts viciously colliding--a mad phantasmagoria of forces! Wickedly it seizes and shakes the Aeroplane; then tries to turn it over sideways; then instantly changes its mind and in a second drops it into a hole a hundred feet deep; and if it were not for his safety belt the Pilot might find his seat sinking away from beneath him. Gusts strike the front of the craft like so many slaps in the face; and others, with the motion of mountainous waves, sometimes lift it hundreds of feet in a few seconds, hoping to see it plunge over the summit in a death-dive--and so it goes on, but the Pilot, perfectly at one with his mount and instantly alert to its slightest motion, is skilfully and naturally making perhaps fifty movements a minute of hand and feet; the former lightly grasping the "joy-stick" which controls the Elevator hinged to the tail, and also the Ailerons or little wings hinged to the wing-tips; and the latter moving the Rudder control-bar. [Illustration: The Pilot's Cock-pit.] A strain on the Pilot? Not a bit of it, for this is his Work which he loves and excels in; and given a cool head, alert eye, and a sensitive touch for the controls, what sport can compare with these ever-changing battles of the air? The Aeroplane has all this time been climbing in great wide circles, and is now some three thousand feet above the Aerodrome which from such height looks absurdly small. The buildings below now seem quite squat; the hills appear to have sunk away into the ground, and the whole country below, cut up into diminutive fields, has the appearance of having been lately tidied and thoroughly spring-cleaned! A doll's country it looks, with tiny horses and cows ornamenting the fields and little model motor-cars and carts stuck on the roads, the latter stretching away across country like ribbons accidentally dropped. At three thousand feet altitude the Pilot is satisfied that he is now sufficiently high to secure, in the event of engine failure, a long enough glide to earth to enable him to choose and reach a good landing-place; and, being furthermore content with the steady running of the engine, he decides to climb no more but to follow the course he has mapped out. Consulting the compass, he places the Aeroplane on the A--E course and, using the Elevator, he gives his craft its minimum angle of incidence at which it will just maintain horizontal flight and secure its maximum speed. Swiftly he speeds away, and few thoughts he has now for the changing panorama of country, cloud, and colour. Ever present in his mind are the three great 'cross-country queries. "Am I on my right course? Can I see a good landing-ground within gliding distance?" And "How is the Engine running?" Keenly both he and the Observer compare their maps with the country below. The roads, khaki-coloured ribbons, are easily seen but are not of much use, for there are so many of them and they all look alike from such an altitude. Now where can that lake be which the map shows so plainly? He feels that surely he should see it by now, and has an uncomfortable feeling that he is flying too far West. What pilot is there indeed who has not many times experienced such unpleasant sensation? Few things in the air can create greater anxiety. Wisely, however, he sticks to his compass course, and the next minute he is rewarded by a sight of the lake, though indeed he now sees that the direction of his travel will not take him over it, as should be the case if he were flying over the shortest route to his destination. He must have slightly miscalculated the velocity or direction of the side-wind. "About ten degrees off," he mutters, and, using the Rudder, corrects his course accordingly. Now he feels happier and that he is well on his way. The gusts, too, have ceased to trouble him as, at this altitude, they are not nearly so bad as they were near the ground, the broken surface of which does much to produce them; and sometimes for miles he makes but a movement or two of the controls. The clouds just above race by with dizzy and uniform speed; the country below slowly unrolls, and the steady drone of the Engine is almost hypnotic in effect. "Sleep, sleep, sleep," it insidiously suggests. "Listen to me and watch the clouds; there's nothing else to do. Dream, dream, dream of speeding through space for ever, and ever, and ever; and rest, rest, rest to the sound of my rhythmical hum. Droning on and on, nothing whatever matters. All things now are merged into speed through space and a sleepy monotonous d-d-r-r-o-o-n-n-e------." But the Pilot pulls himself together with a start and peers far ahead in search of the next landmark. This time it is a little country town, red-roofed his map tells him, and roughly of cruciform shape; and, sure enough, there in the right direction are the broken outlines of a few red roofs peeping out from between the trees. Another minute and he can see this little town, a fairy place it appears, nestling down between the hills and its red roofs and picturesque shape, a glowing and lovely contrast with the dark green of the surrounding moors. So extraordinarily clean and tidy it looks from such a height, and laid out in such orderly fashion with perfectly defined squares, parks, avenues, and public buildings, it indeed appears hardly real, but rather as if it has this very day materialized from some delightful children's book! Every city and town you must know has its distinct individuality to the Pilot's eye. Some are not fairy places at all, but great dark ugly blots upon the fair countryside, and with tall shafts belching forth murky columns of smoke to defile clean space. Others, melancholy-looking masses of grey, slate-roofed houses, are always sad and dispirited; never welcoming the glad sunshine, but ever calling for leaden skies and a weeping Heaven. Others again, little coquettes with village green, white palings everywhere, bright gravel roads, and an irrepressible air of brightness and gaiety. Then there are the rivers, silvery streaks peacefully winding far, far away to the distant horizon; they and the lakes the finest landmarks the Pilot can have. And the forests. How can I describe them? The trees cannot be seen separately, but merge altogether into enormous irregular dark green masses sprawling over the country, and sometimes with great ungainly arms half encircling some town or village; and the wind passing over the foliage at times gives the forest an almost living appearance, as of some great dragon of olden times rousing itself from slumber to devour the peaceful villages its arms encircle. And the Pilot and Observer fly on and on, seeing these things and many others which baffle my poor skill to describe--things, dear Reader, that you shall see, and poets sing of, and great artists paint in the days to come when the Designer has captured Efficiency. Then, and the time is near, shall you see this beautiful world as you have never seen it before, the garden it is, the peace it breathes, and the wonder of it. The Pilot, flying on, is now anxiously looking for the railway line which midway on his journey should point the course. Ah! There it is at last, but suddenly (and the map at fault) it plunges into the earth! Well the writer remembers when that happened to him on a long 'cross-country flight in the early days of aviation. Anxiously he wondered "Are tunnels always straight?" and with what relief, keeping on a straight course, he picked up the line again some three miles farther on! Now at last the Pilot sees the sea, just a streak on the north-eastern horizon, and he knows that his flight is two-thirds over. Indeed, he should have seen it before, but the air is none too clear, and he is not yet able to discern the river which soon should cross his path. As he swiftly speeds on the air becomes denser and denser with what he fears must be the beginning of a sea-fog, perhaps drifting inland along the course of the river. Now does he feel real anxiety, for it is the _duty_ of a Pilot to fear fog, his deadliest enemy. Fog not only hides the landmarks by which he keeps his course, but makes the control of the Aeroplane a matter of the greatest difficulty. He may not realize it, but, in keeping his machine on an even keel, he is unconsciously balancing it against the horizon, and with the horizon gone he is lost indeed. Not only that, but it also prevents him from choosing his landing-place, and the chances are that, landing in a fog, he will smash into a tree, hedge, or building, with disastrous results. The best and boldest pilot 'wares a fog, and so this one, finding the conditions becoming worse and yet worse, and being forced to descend lower and lower in order to keep the earth within view, wisely decides to choose a landing-place while there is yet time to do so. Throttling down the power of the engine he spirals downwards, keenly observing the country below. There are plenty of green fields to lure him, and his great object is to avoid one in which the grass is long, for that would bring his machine to a stop so suddenly as to turn it over; or one of rough surface likely to break the under-carriage. Now is perfect eyesight and a cool head indispensable. He sees and decides upon a field and, knowing his job, he sticks to that field with no change of mind to confuse him. It is none too large, and gliding just over the trees and head on to the wind he skilfully "stalls" his machine; that is, the speed having decreased sufficiently to avoid such a manoeuvre resulting in ascent, he, by means of the Elevator, gives the Aeroplane as large an angle of incidence as possible, and the undersides of the planes meeting the air at such a large angle act as an air-brake, and the Aeroplane, skimming over the ground, lessens its speed and finally stops just at the farther end of the field. Then, after driving the Aeroplane up to and under the lee of the hedge, he stops the engine, and quickly lashing the joy-stick fast in order to prevent the wind from blowing the controlling surfaces about and possibly damaging them, he hurriedly alights. Now running to the tail he lifts it up on to his shoulder, for the wind has become rough indeed and there is danger of the Aeroplane becoming unmanageable. By this action he decreases the angle at which the planes are inclined to the wind and so minimizes the latter's effect upon them. Then to the Observer, "Hurry up, old fellow, and try to find some rope, wire, or anything with which to picket the machine. The wind is rising and I shan't be able to hold the 'bus steady for long. Don't forget the wire-cutters. They're in the tool kit." And the Observer rushes off in frantic haste, before long triumphantly returning with a long length of wire from a neighbouring fence. Blocking up the tail with some debris at hand, they soon succeed, with the aid of the wire, in stoutly picketing the Aeroplane to the roots of the high hedge in front of it; done with much care, too, so that the wire shall not fray the fabric or set up dangerous bending-stresses in the woodwork. Their work is not done yet, for the Observer remarking, "I don't like the look of this thick weather and rather fear a heavy rain-storm," the Pilot replies, "Well, it's a fearful bore, but the first rule of our game is never to take an unnecessary risk, so out with the engine and body covers." Working with a will they soon have the engine and the open part of the body which contains the seats, controls, and instruments snugly housed with their waterproof covers, and the Aeroplane is ready to weather the possible storm. Says the Observer, "I'm remarkably peckish, and methinks I spy the towers of one of England's stately homes showing themselves just beyond that wood, less than a quarter of a mile away. What ho! for a raid. What do you say?" "All right, you cut along and I'll stop here, for the Aeroplane must not be left alone. Get back as quickly as possible." And the Observer trots off, leaving the Pilot filling his pipe and anxiously scrutinizing the weather conditions. Very thick it is now, but the day is yet young, and he has hopes of the fog lifting sufficiently to enable the flight to be resumed. A little impatiently he awaits the return of his comrade, but with never a doubt of the result, for the hospitality of the country house is proverbial among pilots! What old hand among them is there who cannot instance many a forced landing made pleasant by such hospitality? Never too late or too early to help with food, petrol, oil, tools, and assistants. Many a grateful thought has the writer for such kind help given in the days before the war (how long ago they seem!), when aeroplanes were still more imperfect than they are now, and involuntary descents often a part of 'cross-country flying. Ah! those early days! How fresh and inspiring they were! As one started off on one's first 'cross-country flight, on a machine the first of its design, and with everything yet to learn, and the wonders of the air yet to explore; then the joy of accomplishment, the dreams of Efficiency, the hard work and long hours better than leisure; and what a field of endeavour--the realms of space to conquer! And the battle still goes on with ever-increasing success. Who is bold enough to say what its limits shall be? So ruminates this Pilot-Designer, as he puffs at his pipe, until his reverie is abruptly disturbed by the return of the Observer. "Wake up, you _airman_," the latter shouts. "Here's the very thing the doctor ordered! A basket of first-class grub and something to keep the fog out, too." "Well, that's splendid, but don't call me newspaper names or you'll spoil my appetite!" Then, with hunger such as only flying can produce, they appreciatively discuss their lunch, and with many a grateful thought for the donors--and they talk shop. They can't help it, and even golf is a poor second to flight talk. Says the Pilot, who must have his grievance, "Just observe where I managed to stop the machine. Not twenty feet from this hedge! A little more and we should have been through it and into Kingdom Come! I stalled as well as one could, but the tail touched the ground and so I could not give the Aeroplane any larger angle of incidence. Could I have given it a larger angle, then the planes would have become a much more effective air-brake, and we should have come to rest in a much shorter distance. It's all the fault of the tail. There's hardly a type of Aeroplane in existence in which the tail could not be raised several feet, and that would make all the difference. A high tail means a large angle of incidence when the machine touches ground and, with enough angle, I'll guarantee to safely land the fastest machine in a five-acre field. You can, I am sure, imagine what a difference that would make where forced landings are concerned!" Then rapidly sketching in his notebook, he shows the Observer the following illustration: [Illustration: The Pilot's Aeroplane. The Change of Design He Would Like.] "That's very pretty," said the Observer, "but how about Mechanical Difficulties, and Efficiency in respect of Flight? And, anyway, why hasn't such an obvious thing been done already?" "As regards the first part of your question I assure you that there's nothing in it, and I'll prove it to you as follows----" "Oh! That's all right, old chap. I'll take your word for it," hurriedly replies the Observer, whose soul isn't tuned to a technical key. "As regards the latter part of your inquiry," went on the Pilot, a little nettled at having such a poor listener, "it's very simple. Aeroplanes have 'just growed' like Topsy, and they consequently contain this and many another relic of early day design when Aeroplanes were more or less thrown together and anything was good enough that could get off the ground." "By Jove," interrupts the Observer, "I do believe the fog is lifting. Hadn't we better get the engine and body covers off, just in case it's really so?" "I believe you're right. I am sure those hills over there could not be seen a few minutes ago, and look--there's sunshine over there. We'd better hurry up." Ten minutes' hard work and the covers are off, neatly folded and stowed aboard; the picketing wires are cast adrift, and the Pilot is once more in his seat. The Aeroplane has been turned to face the other end of the field, and, the Observer swinging round the propeller, the engine is awake again and slowly ticking over. Quickly the Observer climbs into his seat in front of the Pilot, and, the latter slightly opening the throttle, the Aeroplane leisurely rolls over the ground towards the other end of the field, from which the ascent will be made. Arriving there the Pilot turns the Aeroplane in order to face the wind and thus secure a quick "get-off." Then he opens the throttle fully and the mighty voice of the Engine roars out "Now see me clear that hedge!" and the Aeroplane races forward at its minimum angle of incidence. Tail up, and with ever-increasing speed, it rushes towards the hedge under the lee of which it has lately been at rest; and then, just as the Observer involuntarily pulls back an imaginary joy-stick, the Pilot moves the real one and places the machine at its best climbing angle. Like a living thing it responds, and instantly leaves the ground, clearing the hedge like a--well, like an Aeroplane with an excellent margin of lift. Upwards it climbs with even and powerful lift, and the familiar scenes below again gladden the eyes of the Pilot. Smaller and more and more squat grow the houses and hills; more and more doll-like appear the fields which are clearly outlined by the hedges; and soon the country below is easily identified with the map. Now they can see the river before them and a bay of the sea which must be crossed or skirted. The fog still lingers along the course of the river and between the hills, but is fast rolling away in grey, ghost-like masses. Out to sea it obscures the horizon, making it difficult to be sure where water ends and fog begins, and creating a strange, rather weird, effect by which ships at a certain distance appear to be floating in space. Now the Aeroplane is almost over the river, and the next instant it suddenly drops into a "hole in the air." With great suddenness it happens, and for some two hundred feet it drops nose-down and tilted over sideways; but the Pilot is prepared and has put his craft on an even keel in less time than it takes to tell you about it; for well he knows that he must expect such conditions when passing over a shore or, indeed, any well-defined change in the composition of the earth's surface. Especially is this so on a hot and sunny day, for then the warm surface of the earth creates columns of ascending air, the speed of the ascent depending upon the composition of the surface. Sandy soil, for instance, such as borders this river produces a quickly ascending column of air, whereas water and forests have not such a marked effect. Thus, when our Aeroplane passed over the shore of the river, it suddenly lost the lift due to the ascending air produced by the warm sandy soil, and it consequently dropped just as if it had fallen into a hole. Now the Aeroplane is over the bay and, the sea being calm, the Pilot looks down, down through the water, and clearly sees the bottom, hundreds of feet below the surface. Down through the reflection of the blue sky and clouds, and one might think that is all, but it isn't. Only those who fly know the beauties of the sea as viewed from above; its dappled pearly tints; its soft dark blue shadows; the beautiful contrasts of unusual shades of colour which are always differing and shifting with the changing sunshine and the ever moving position of the aerial observer. Ah! for some better pen than mine to describe these things! One with glowing words and a magic rhythm to express the wonders of the air and the beauty of the garden beneath--the immensity of the sea--the sense of space and of one's littleness there--the realization of the Power moving the multitudes below--the exaltation of spirit altitude produces--the joy of speed. A new world of sensation! Now the bay is almost crossed and the Aerodrome at B. can be distinguished.... * * * * * On the Aerodrome is a little crowd waiting and watching for the arrival of the Aeroplane, for it is of a new and improved type and its first 'cross-country performance is of keen interest to these men; men who really know something about flight. There is the Squadron Commander who has done some real flying in his time; several well-seasoned Flight-Commanders; a dozen or more Flight-Lieutenants; a knowledgeable Flight-Sergeant; a number of Air Mechanics, and, a little on one side and almost unnoticed, the Designer. "I hope they are all right," says someone, "and that they haven't had difficulties with the fog. It rolled up very quickly, you know." "Never fear," remarks a Flight-Commander. "I know the Pilot well and he's a good 'un; far too good to carry on into a fog." "They say the machine is really something out of the ordinary," says another, "and that, for once, the Designer has been allowed full play; that he hasn't been forced to unduly standardize ribs, spars, struts, etc., and has more or less had his own way. I wonder who he is. It seems strange we hear so little of him." "Ah! my boy. You do a bit more flying and you'll discover that things are not always as they appear from a distance!" "There she is, sir!" cries the Flight-Sergeant. "Just a speck over the silvery corner of that cloud." A tiny speck it looks, some six miles distant and three thousand feet high; but, racing along, it rapidly appears larger and soon its outlines can be traced and the sunlight be seen playing upon the whirling propeller. Now the distant drone of the engine can be heard, but not for long, for suddenly it ceases and, the nose of the Aeroplane sinking, the craft commences gliding downwards. "Surely too far away," says a subaltern. "It will be a wonderful machine if, from that distance and height, it can glide into the Aerodrome." And more than one express the opinion that it cannot be done; but the Designer smiles to himself, yet with a little anxiety, for his reputation is at stake, and Efficiency, the main reward he desires, is perhaps, or perhaps not, at last within his grasp! Swiftly the machine glides downwards towards them, and it can now be seen how surprisingly little it is affected by the rough weather and gusts; so much so that a little chorus of approval is heard. "Jolly good gliding angle," says someone; and another, "Beautifully quick controls, what?" and from yet another, "By Jove! The Pilot must be sure of the machine. Look, he's stopped the engine entirely." Then the Aeroplane with noiseless engine glides over the boundary of the Aerodrome, and, with just a soft soughing sound from the air it cleaves, lands gently not fifty yards from the onlookers. "Glad to see you," says the Squadron Commander to the Pilot. "How do you like the machine?" And the Pilot replies: "I never want a better one, sir. It almost flies itself!" And the Designer turns his face homewards and towards his beloved drawing-office; well satisfied, but still dreaming dreams of the future and ... looking far ahead who should he see but Efficiency at last coming towards him! And to him she is all things. In her hair is the morning sunshine; her eyes hold the blue of the sky, and on her cheeks is the pearly tint of the clouds as seen from above. The passion of speed, the lure of space, the sense of power, and the wonder of the future ... all these things she holds for him. "Ah!" he cries. "You'll never leave me now, when at last there is no one between us?" And Efficiency, smiling and blushing, but practical as ever, says: "And you will never throw those Compromises in my face?" "My dear, I love you for them! Haven't they been my life ever since I began striving for you ten long years ago?" And so they walk off very happily, arm-in-arm together; and if this hasn't bored you and you'd like some more of the same sort of thing, I'd just love to tell you some day of the wonderful things they accomplish together, and of what they dream the future holds in store. [Illustration] _And that's the end of the Prologue._ CHAPTER I FLIGHT Air has weight (about 13 cubic feet = 1 lb.), inertia, and momentum. It therefore obeys Newton's laws[14] and resists movement. It is that resistance or reaction which makes flight possible. Flight is secured by driving through the air a surface[15] inclined upwards and towards the direction of motion. [Illustration] S = Side view of surface. M = Direction of motion. CHORD.--The Chord is, for practical purposes, taken to be a straight line from the leading edge of the surface to its trailing edge. N = A line through the surface starting from its trailing edge. The position of this line, which I call the _Neutral Lift Line_, is found by means of wind-tunnel research, and it varies with differences in the camber (curvature) of surfaces. In order to secure flight, the inclination of the surface must be such that the neutral lift line makes an angle with and _above_ the line of motion. If it is coincident with M, there is no lift. If it makes an angle with M and _below_ it, then there is a pressure tending to force the surface down. I = Angle of Incidence. This angle is generally defined as the angle the chord makes with the direction of motion, but that is a bad definition, as it leads to misconception. The angle of incidence is best described as the angle the neutral lift line makes with the direction of motion relative to the air. You will, however, find that in nearly all rigging specifications the angle of incidence is taken to mean the angle the chord makes with a line parallel to the propeller thrust. This is necessary from the point of view of the practical mechanic who has to rig the aeroplane, for he could not find the neutral lift line, whereas he can easily find the chord. Again, he would certainly be in doubt as to "the direction of motion relative to the air," whereas he can easily find a line parallel to the propeller thrust. It is a pity, however, that these practical considerations have resulted in a bad definition of the angle of incidence becoming prevalent, a consequence of which has been the widespread fallacy that flight may be secured with a negative inclination of the surface. Flight may conceivably be secured with a negative angle of chord, but never with a negative inclination of the surface, if, as seems reasonable, we regard the surface from the point of view of the neutral lift line. All this is only applicable to cambered surfaces. In the case of flat surfaces the neutral lift line coincides with the chord and the definition I have criticized adversely is then applicable. Flat lifting surfaces are, however, never used. The surface acts upon the air in the following manner: [Illustration] As the bottom of the surface meets the air, it compresses it and accelerates it _downwards_. As a result of this definite action there is, of course, an equal and opposite reaction _upwards_. The top surface, in moving forward, tends to leave the air behind it, thus creating a semi-vacuum or rarefied area over the top of the surface. Consequently the pressure of air on the top of the surface is decreased, thus assisting the reaction below to lift the surface _upwards_. The reaction increases approximately as the square of the velocity. It is the result of (1) the mass of air engaged, and (2) the velocity and consequent force with which the surface engages the air. If the reaction was produced by only one of those factors it would increase in direct proportion to the velocity, but, since it is the product of both factors, it increases as V^2. Approximately three-fifths of the reaction is due to the decrease of density (and consequent decrease of downward pressure) on the top of the surface; and only some two-fifths is due to the upward reaction secured by the action of the bottom surface upon the air. A practical point in respect of this is that, in the event of the fabric covering the surface getting into bad condition, it is more likely to strip off the top than off the bottom. [Illustration] The direction of the reaction is, at efficient angles of incidence, approximately at right-angles to the neutral lift line of the surface, as illustrated above; and it is, in considering flight, convenient to divide it into two component parts or values, thus: 1. The vertical component of the reaction, _i.e._, Lift, which is opposed to Gravity, _i.e._, the weight of the aeroplane. 2. The horizontal component, _i.e._, Drift (sometimes called Resistance), to which is opposed the thrust of the propeller. The direction of the reaction is, of course, the resultant of the forces Lift and Drift. The Lift is the useful part of the reaction, for it lifts the weight of the aeroplane. The Drift is the villain of the piece, and must be overcome by the Thrust in order to secure the necessary velocity to produce the requisite lift for flight. DRIFT.--The drift of the whole aeroplane (we have considered only the lifting surface heretofore) may be conveniently divided into three parts, as follows: _Active Drift_, which, is the drift produced by the lifting surfaces. _Passive Drift_, which is the drift produced by all the rest of the aeroplane--the struts, wires, fuselage, under-carriage, etc., all of which is known as "detrimental surface." _Skin Friction_, which is the drift produced by the friction of the air with roughness of surface. The latter is practically negligible having regard to the smooth surface of the modern aeroplane, and its comparatively slow velocity compared with, for instance, the velocity of a propeller blade. LIFT-DRIFT RATIO.--The proportion of lift to drift is known as the lift-drift ratio, and is of paramount importance, for it expresses _the efficiency of the aeroplane_ (as distinct from engine and propeller). A knowledge of the factors governing the lift-drift ratio is, as will be seen later, _an absolute necessity_ to anyone responsible for the rigging of an aeroplane, and the maintenance of it in an efficient and safe condition. Those factors are as follows: 1. _Velocity_.--The greater the velocity the greater the proportion of drift to lift, and consequently the less the efficiency. Considering the lifting surfaces alone, both the lift and the (active) drift, being component parts of the reaction, increase as the square of the velocity, and the efficiency remains the same at all speeds. But, considering the whole aeroplane, we must remember the passive drift. It also increases as the square of the velocity (with no attendant lift), and, adding itself to the active drift, results in increasing the proportion of total drift (active + passive) to lift. But for the increase in passive drift the efficiency of the aeroplane would not fall with increasing velocity, and it would be possible, by doubling the thrust, to approximately double the speed or lift--a happy state of affairs which can never be, but which we may, in a measure, approach by doing everything possible to diminish the passive drift. Every effort is then made to decrease it by "stream-lining," _i.e._, by giving all "detrimental" parts of the aeroplane a form by which they will pass through the air with the least possible drift. Even the wires bracing the aeroplane together are, in many cases, stream-lined, and with a markedly good effect upon the lift-drift ratio. In the case of a certain well-known type of aeroplane the replacing of the ordinary wires by stream-lined wires added over five miles an hour to the flight speed. [Illustration] _Head-resistance_ is a term often applied to passive drift, but it is apt to convey a wrong impression, as the drift is not nearly so much the result of the head or forward part of struts, wires, etc., as it is of the rarefied area behind. Above is illustrated the flow of air round two objects moving in the direction of the arrow M. In the case of A, you will note that the rarefied area DD is of very considerable extent; whereas in the case of B, the air flows round it in such a way as to meet very closely to the rear of the object, thus _decreasing_ DD. The greater the rarefied area DD, then, the less the density, and, consequently, the less the pressure of air upon the rear of the object. The less such pressure, then, the better is head-resistance D able to get its work in, and the more thrust will be required to overcome it. The "fineness" of the stream-line shape, _i.e._, the proportion of length to width, is determined by the velocity--the greater the velocity, the greater the fineness. The best degree of fineness for any given velocity is found by means of wind-tunnel research. The practical application of all this is, from a rigging point of view, the importance of adjusting all stream-line parts to be dead-on in the line of flight, but more of that later on. 2. _Angle of Incidence_.--The most efficient angle of incidence varies with the thrust at the disposal of the designer, the weight to be carried, and the climb-velocity ratio desired. The best angles of incidence for these varying factors are found by means of wind-tunnel research and practical trial and error. Generally speaking, the greater the velocity the smaller should be the angle of incidence, in order to preserve a clean, stream-line shape of rarefied area and freedom from eddies. Should the angle be too great for the velocity, then the rarefied area over the top of the surface becomes of irregular shape with attendant turbulent eddies. Such eddies possess no lift value, and since it has taken power to produce them, they represent drift and adversely affect the lift-drift ratio. Also, too great an angle for the velocity will result in the underside of the surface tending to compress the air against which it is driven rather than accelerate it _downwards_, and that will tend to produce drift rather than the _upwards_ reaction, or lift. From a rigging point of view, one must presume that every standard aeroplane has its lifting surface set at the most efficient angle, and the practical application of all this is in taking the greatest possible care to rig the surface at the correct angle and to maintain it at such angle. Any deviation will adversely affect the lift-drift ratio, _i.e._, the efficiency. 3. _Camber_.--(Refer to the second illustration in this chapter.) The lifting surfaces are cambered, _i.e._, curved, in order to decrease the horizontal component of the reaction, _i.e._, the drift. _The bottom camber_: If the bottom of the surface was flat, every particle of air meeting it would do so with a shock, and such shock would produce a very considerable horizontal reaction or drift. By curving it such shock is diminished, and the curve should be such as to produce a uniform (not necessarily constant) acceleration and compression of the air from the leading edge to the trailing edge. Any unevenness in the acceleration and compression of the air produces drift. _The top camber_: If this was flat it would produce a rarefied area of irregular shape. I have already explained the bad effect this has upon the lift-drift ratio. The top surface is then curved to produce a rarefied area the shape of which shall be as stream-line and free from attendant eddies as possible. The camber varies with the angle of incidence, the velocity, and the thickness of the surface. Generally speaking, the greater the velocity, the less the camber and angle of incidence. With infinite velocity the surface would be set at no angle of incidence (the neutral lift line coincident with the direction of motion relative to the air), and would be, top and bottom, of pure stream-line form--_i.e._, of infinite fineness. This is, of course, carrying theory to absurdity as the surface would then cease to exist. The best cambers for varying velocities, angles of incidence, and thickness of surface, are found by means of wind-tunnel research. The practical application of all this is in taking the greatest care to prevent the surface from becoming distorted and thus spoiling the camber and consequently the lift-drift ratio. 4. _Aspect Ratio_.--This is the proportion of span to chord. Thus, if the span is, for instance, 50 feet and the chord 5 feet, the surface would be said to have an aspect ratio of 10 to 1. For _a given velocity_ and _a given area_ of surface, the higher the aspect ratio, the greater the reaction. It is obvious, I think, that the greater the span, the greater the mass of undisturbed air engaged, and, as already explained, the reaction is partly the result of the mass of air engaged. I say "undisturbed" advisedly, for otherwise it might be argued that, whatever the shape of the surface, the same mass of air would be engaged. The word "undisturbed" makes all the difference, for it must be remembered that the rear part of the underside of the surface engages air most of which has been deflected downwards by the surface in front of it. That being so, the rear part of the surface has not the same opportunity of forcing; the air downwards (since it is already flowing downwards) and securing there from an upwards, reaction as has the surface in front of it. It is therefore of less value for its area than the front part of the surface, since it does less work and secures less reaction--_i.e._, lift. Again, the rarefied area over the top of the surface is most rare towards the front of it, as, owing to eddies, the rear of such area tends to become denser. [Illustration] Thus, you see, the front part of the surface is the most valuable from the point of view of securing an upwards reaction from the air; and so, by increasing the proportion of front, or "span," to chord, we increase the amount of reaction for a given velocity and area of surface. That means a better proportion of reaction to weight of surface, though the designer must not forget the drift of struts and wires necessary to brace up a surface of high aspect ratio. Not only that, but, _provided_ the chord is not decreased to an extent making it impossible to secure the best camber owing to the thickness of the surface, the higher the aspect ratio, the better the lift-drift ratio. The reason of this is rather obscure. It is sometimes advanced that it is owing to the "spill" of air from under the wing-tips. With a high aspect ratio the chord is less than would otherwise be the case. Less chord results in smaller wing-tips and consequently less "spill." This, however, appears to be a rather inadequate reason for the high aspect ratio producing the high lift-drift ratio. Other reasons are also advanced, but they are of such a contentious nature I do not think it well to go into them here. They are of interest to designers, but this is written for the practical pilot and rigger. 5. _Stagger_.--This is the advancement of the top surface relative to the bottom surface, and is not, of course, applicable to a single surface, _i.e._, a monoplane. In the case of a biplane having no stagger, there will be "interference" and consequent loss of efficiency unless the gap between the top and bottom surfaces is equal to not less than about 1-1/2 times the chord. If less than that, the air engaged by the bottom of the top surface will have a tendency to be drawn into the rarefied area over the top of the bottom surface, with the result that the surfaces will not secure as good a reaction as would otherwise be the case. It is not practicable to have a gap of much more than a distance equal to the chord, owing to the drift produced by the great length of struts and wires such a large gap would necessitate. By staggering the top surface forward, however, it is removed from the action of the lower surface and engages undisturbed air, with the result that the efficiency can in this way be increased by about 5 per cent. Theoretically the top plane should be staggered forward for a distance equal to about 30 per cent. of the chord, the exact distance depending upon the velocity and angle of incidence; but this is not always possible to arrange in designing an aeroplane, owing to difficulties of balance, desired position, and view of pilot, observer, etc. [Illustration: H.E., Horizontal equivalent. D., Dihedral angle.] 6. _Horizontal Equivalent._-The vertical component of the reaction, _i.e._, lift, varies as the horizontal equivalent (H.E.) of the surface, but the drift remains the same. Then it follows that if H.E. grows less, the ratio of lift to drift must do the same. A, B, and C are front views of three surfaces. A has its full H.E., and therefore, from the point of view from which we are at the moment considering efficiency, it has its best lift-drift ratio. B and C both possess the same surface as A, but one is inclined upwards from its centre and the other is straight but tilted. For these reasons their H.E.'s are, as illustrated, less than in the case of A, That means less vertical lift, and, the drift remaining the same (for there is the same amount of surface as in A to produce it), the lift-drift ratio falls. THE MARGIN OF POWER is the power available above that necessary to maintain horizontal flight. THE MARGIN OF LIFT is the height an aeroplane can gain in a given time and starting from a given altitude. As an example, thus: 1,000 feet the first minute, and starting from an altitude of 500 feet above sea-level. The margin of lift decreases with altitude, owing to the decrease in the density of the air, which adversely affects the engine. Provided the engine maintained its impulse with altitude, then, if we ignore the problem of the propeller, which I will go into later on, the margin of lift would not disappear. Moreover, greater velocity for a given power would be secured at a greater altitude, owing to the decreased density of air to be overcome. After reading that you may like to light your pipe and indulge in dreams of the wonderful possibilities which may become realities if some brilliant genius shows us some day how to secure a constant power with increasing altitude. I am afraid, however, that will always remain impossible; but it is probable that some very interesting steps may be taken in that direction. THE MINIMUM ANGLE OF INCIDENCE is the smallest angle at which, for a given power, surface (including detrimental surface), and weight, horizontal flight can be maintained. THE MAXIMUM ANGLE OF INCIDENCE is the greatest angle at which, for a given power, surface (including detrimental surface), and weight, horizontal flight can be maintained. THE OPTIMUM ANGLE OF INCIDENCE is the angle at which the lift-drift ratio is highest. In modern aeroplanes it is that angle of incidence possessed by the surface when the axis of the propeller is horizontal. THE BEST CLIMBING ANGLE is approximately half-way between the maximum and the optimum angles. All present-day aeroplanes are a compromise between Climb and horizontal Velocity. We will compare the essentials for two aeroplanes, one designed for maximum climb, and the other for maximum velocity. ESSENTIALS FOR MAXIMUM CLIMB: 1. _Low velocity_, in order to secure the best lift-drift ratio. 2. Having a low velocity, _a large surface_ will be necessary in order to engage the necessary mass of air to secure the requisite lift. [Illustration] 3. Since (1) such a climbing machine will move along an upward sloping path, and (2) will climb with its propeller thrust horizontal, then a _large angle relative to the direction of the thrust_ will be necessary in order to secure the requisite angle relative to the direction of motion. The propeller thrust should be always horizontal, because the most efficient flying-machine (having regard to climb or velocity) has, so far, been found to be an arrangement of an inclined surface driven by a _horizontal_ thrust--the surface lifting the weight, and the thrust overcoming the drift. This is, in practice, a far more efficient arrangement than the helicopter, _i.e._, the air-screw revolving about a vertical axis and producing a thrust opposed to gravity. If, when climbing, the propeller thrust is at such an angle as to tend to haul the aeroplane upwards, then it is, in a measure, acting as a helicopter, and that means inefficiency. The reason of a helicopter being inefficient in practice is due to the fact that, owing to mechanical difficulties, it is impossible to construct within a reasonable weight an air-screw of the requisite dimensions. That being so, it would be necessary, in order to absorb the power of the engine, to revolve the comparatively small-surfaced air screw at an immensely greater velocity than that of the aeroplane's surface. As already explained, the lift-drift ratio falls with velocity on account of the increase in passive drift. This applies to a blade of a propeller or air-screw which is nothing but a revolving surface set at angle of incidence, and which it is impossible to construct without a good deal of detrimental surface near the central boss. 4. The velocity being low, then it follows that for that reason also _the angle of incidence should be comparatively large_. 5. _Camber_.--Since such an aeroplane would be of low velocity, and therefore possess a large angle of incidence, a _large camber_ would be necessary. Let us now consider the essentials for an aeroplane of maximum velocity for its power, and possessing merely enough lift to get off the ground, but no margin of lift. 1. Comparatively _high velocity_. 2. A comparatively _small surface_, because, being of greater velocity than the maximum climber, a greater mass of air will be engaged for a given surface and time, and therefore a smaller surface will be sufficient to secure the requisite lift. 3. _A small angle relative to the propeller thrust_, since the latter coincides with the direction of motion. 4. A comparatively _small angle of incidence_ by reason of the high velocity. 5. A comparatively _small camber_ follows as a result of the small angle of incidence. [Illustration: ANGLES OF INCIDENCE (INDICATED APPROXIMATELY) OF AN AEROPLANE DESIGNED AS A COMPROMISE BETWEEN VELOCITY AND CLIMB, AND POSSESSING A SLIGHT MARGIN OF LIFT AT A LOW ALTITUDE AND WHEN THE THRUST IS HORIZONTAL.] MINIMUM ANGLE. This gives the greatest velocity during horizontal flight at a low altitude. Greater velocity would be secured if the surface, angle, and camber were smaller and designed to just maintain horizontal flight with a horizontal thrust. Also, in such case, the propeller would not be thrusting downwards, but along a horizontal line which is obviously a more efficient arrangement if we regard the aeroplane merely from one point of view, _i.e._, either with reference to velocity or climb. OPTIMUM ANGLE. (Thrust horizontal). The velocity is less than at the smaller minimum angle, and, as aeroplanes are designed to-day, the area and angle of incidence of the surface is such as to secure a slight ascent at a low altitude. The camber of the surface is designed for this angle of incidence and velocity. The lift-drift ratio is best at this angle. BEST CLIMBING ANGLE. The velocity is now still less by reason of the increased angle producing increase of drift. Less velocity at a given angle produces less lift, but the increased angle more or less offsets the loss of lift due to the decreased velocity; and, in addition, the thrust is now hauling the aeroplane upwards. MAXIMUM ANGLE. The greater angle has now produced so much drift as to lessen the velocity to a point where the combined lifts from the surface and from the thrust are only just able to maintain horizontal flight. Any greater angle will result in a still lower lift-drift ratio. The lift will then become less than the weight and the aeroplane will consequently fall. Such a fall is known as "stalling" or "pancaking." =NOTE.--The golden rule for beginners: Never exceed the Best Climbing Angle. Always maintain the flying speed of the aeroplane.= SUMMARY. _Essentials for Maximum Climb._ 1. Low velocity. 2. Large surface. 3. Large angle relative to propeller thrust. 4. Large angle relative to direction of motion. 5. Large camber. _Essentials for Maximum Velocity._ 1. High velocity. 2. Small surface. 3. Small angle relative to propeller thrust. 4. Small angle relative to direction of motion. 5. Small camber. It is mechanically impossible to construct an aeroplane of reasonable weight of which it would be possible to vary the above opposing essentials. Therefore, all aeroplanes are designed as a compromise between Climb and Velocity. As a rule aeroplanes are designed to have at low altitude a slight margin of lift when the propeller thrust is horizontal. By this means, when the altitude is reached where the margin of lift disappears (on account of loss of engine power), and which is, consequently, the altitude where it is just possible to maintain horizontal flight, the aeroplane is flying with its thrust horizontal and with maximum efficiency (as distinct from engine and propeller efficiency). The margin of lift at low altitude, and when the thrust is horizontal, should then be such that the higher altitude at which the margin of lift is lost is that altitude at which most of the aeroplane's horizontal flight work is done. That ensures maximum velocity when most required. Unfortunately, where aeroplanes designed for fighting are concerned, the altitude where most of the work is done is that at which both maximum velocity and maximum margin of lift for power are required. Perhaps some day a brilliant inventor will design an aeroplane of reasonable weight and drift of which it will be possible for the pilot to vary at will the above-mentioned opposing essentials. Then we shall get maximum velocity, or maximum margin of lift, for power as required. Until then the design of the aeroplane must remain a compromise between Velocity and Climb. [Footnote 14: See Newton's laws in the Glossary at the end of the book.] [Footnote 15: See "Aerofoil" in the Glossary.] CHAPTER II STABILITY AND CONTROL STABILITY is a condition whereby an object disturbed has a natural tendency to return to its first and normal position. Example: a weight suspended by a cord. INSTABILITY is a condition whereby an object disturbed has a natural tendency to move as far as possible away from its first position, with no tendency to return. Example: a stick balanced vertically upon your finger. NEUTRAL INSTABILITY is a condition whereby an object disturbed has no tendency to move farther than displaced by the force of the disturbance, and no tendency to return to its first position. In order that an aeroplane may be reasonably controllable, it is necessary for it to possess some degree of stability longitudinally, laterally, and directionally. LONGITUDINAL STABILITY in an aeroplane is its stability about an axis transverse to the direction of normal horizontal flight, and without which it would pitch and toss. LATERAL STABILITY is its stability about its longitudinal axis, and without which it would roll sideways. DIRECTIONAL STABILITY is its stability about its vertical axis, and without which it would have no tendency to keep its course. For such directional stability to exist there must be, in effect,[16] more "keel-surface" behind the vertical axis than there is in front of it. By keel-surface I mean everything to be seen when looking at an aeroplane from the side of it--the sides of the body, undercarriage, struts, wires, etc. The same thing applies to a weathercock. You know what would happen if there was insufficient keel-surface behind the vertical axis upon which it is pivoted. It would turn off its proper course, which is opposite to the direction of the wind. It is very much the same in the case of an aeroplane. [Illustration] The above illustration represents an aeroplane (directionally stable) flying along the course B. A gust striking it as indicated acts upon the greater proportion of keel-surface behind the turning axis and throws it into the new course. It does not, however, travel along the new course, owing to its momentum in the direction B. It travels, as long as such momentum lasts, in a direction which is the resultant of the two forces Thrust and Momentum. But the centre line of the aeroplane is pointing in the direction of the new course. Therefore its attitude, relative to the direction of motion, is more or less sideways, and it consequently receives an air pressure in the direction C. Such pressure, acting upon the keel-surface, presses the tail back towards its first position in which the aeroplane is upon its course B. What I have described is continually going on during flight, but in a well-designed aeroplane such stabilizing movements are, most of the time, so slight as to be imperceptible to the pilot. If an aeroplane was not stabilized in this way, it would not only be continually trying to leave its course, but it would also possess a dangerous tendency to "nose away" from the direction of the side gusts. In such case the gust shown in the above illustration would turn the aeroplane round the opposite way a very considerable distance; and the right wing, being on the outside of the turn, would travel with greater velocity than the left wing. Increased velocity means increased lift; and so, the right wing lifting, the aeroplane would turn over sideways very quickly. LONGITUDINAL STABILITY.--Flat surfaces are longitudinally stable owing to the fact that with decreasing angles of incidence the centre line of pressure (C.P.) moves forward. The C.P. is a line taken across the surface, transverse to the direction of motion, and about which all the air forces may be said to balance, or through which they may be said to act. [Illustration] Imagine A to be a flat surface, attitude vertical, travelling through the air in the direction of motion M. Its C.P. is then obviously along the exact centre line of the surface as illustrated. In B, C, and D the surfaces are shown with angles of incidence decreasing to nothing, and you will note that the C.P. moves forward with the decreasing angle.[17] Now, should some gust or eddy tend to make the surface decrease the angle, _i.e._, dive, then the C.P. moves forward and pushes the front of the surface up. Should the surface tend to assume too large an angle, then the reverse happens--the C.P. moves back and pushes the rear of the surface up. Flat surfaces are, then, theoretically stable longitudinally. They are not, however, used, on account of their poor lift-drift ratio. As already explained, cambered surfaces are used, and these are longitudinally unstable at those angles of incidence producing a reasonable lift-drift ratio, _i.e._, at angles below about 12°. A is a cambered surface, attitude approximately vertical, moving through the air in the direction M. Obviously the C.P. coincides with the transverse centre line of the surface. With decreasing angles, down to angles of about 30°, the C.P. moves forward as in the case of flat surfaces (see B); but angles above 30° do not interest us, since they produce a very low ratio of lift to drift. [Illustration] Below angles of about 30° (see C) the dipping front part of the surface assumes a negative angle of incidence resulting in the _downward_ air pressure D, and the more the angle of incidence is decreased, the greater such negative angle and its resultant pressure D. Since the C.P. is the resultant of all the air forces, its position is naturally affected by D, which causes it to move backwards. Now, should some gust or eddy tend to make the surface decrease its angle of incidence, _i.e._, dive, then the C.P. moves backwards, and, pushing up the rear of the surface, causes it to dive the more. Should the surface tend to assume too large an angle, then the reverse happens; the pressure D decreases, with the result that C.P. moves forward and pushes up the front of the surface, thus increasing the angle still further, the final result being a "tail-slide." It is therefore necessary to find a means of stabilizing the naturally unstable cambered surface. This is usually secured by means of a stabilizing surface fixed some distance in the rear of the main surface, and it is a necessary condition that the neutral lift lines of the two surfaces, when projected to meet each other, make a dihedral angle. In other words, the rear stabilizing surface must have a lesser angle of incidence than the main surface--certainly not more than one-third of that of the main surface. This is known as the longitudinal dihedral. [Illustration] I may add that the tail-plane is sometimes mounted upon the aeroplane at the same angle as the main surface, but, in such cases, it attacks air which has received a downward deflection from the main surface, thus: [Illustration] The angle at which the tail surface attacks the air (the angle of incidence) is therefore less than the angle of incidence of the main surface. I will now, by means of the following illustration, try to explain how the longitudinal dihedral secures stability: [Illustration] First, imagine the aeroplane travelling in the direction of motion, which coincides with the direction of thrust T. The weight is, of course, balanced about a C.P., the resultant of the C.P. of the main surface and the C.P. of the stabilizing surface. For the sake of illustration, the stabilizing surface has been given an angle of incidence, and therefore has a lift and C.P. In practice the stabilizer is often set at no angle of incidence. In such case the proposition remains the same, but it is, perhaps, a little easier to illustrate it as above. Now, we will suppose that a gust or eddy throws the machine into the lower position. It no longer travels in the direction of T, since the momentum in the old direction pulls it off that course. M is now the resultant of the Thrust and the Momentum, and you will note that this results in a decrease in the angle our old friend the neutral lift line makes with M, _i.e._, a decrease in the angle of incidence and therefore a decrease in lift. We will suppose that this decrease is 2°. Such decrease applies to both main surface and stabilizer, since both are fixed rigidly to the aeroplane. The main surface, which had 12° angle, has now only 10°, _i.e._, a loss of _one-sixth_. The stabilizer, which had 4° angle, has now only 2°, _i.e._, a loss of _one-half_. The latter has therefore lost a greater _proportion_ of its angle of incidence, and consequently its lift, than has the main surface. It must then fall relative to the main surface. The tail falling, the aeroplane then assumes its first position, though at a slightly less altitude. Should a gust throw the nose of the aeroplane up, then the reverse happens. Both main surface and stabilizer increase their angles of incidence in the same amount, but the angle, and therefore the lift, of the stabilizer increases in greater proportion than does the angle and lift of the main surface, with the result that it lifts the tail. The aeroplane then assumes its first position, though at a slightly greater altitude. Do not fall into the widespread error that the angle of incidence varies as the angle of the aeroplane to the horizontal. It varies with such angle, but not as anything approaching it. Remember that the stabilizing effect of the longitudinal dihedral lasts only as long as there is momentum in the direction of the first course. These stabilizing movements are taking place all the time, even though imperceptible to the pilot. Aeroplanes have, in the past, been built with a stabilizing surface in front of the main surface instead of at the rear of it. In such design the main surface (which is then the tail surface as well as the principal lifting surface) must be set at a less angle than the forward stabilizing surface, in order to secure a longitudinal dihedral. The defect of such design lies in the fact that the main surface must have a certain angle to lift the weight--say 5°. Then, in order to secure a sufficiency of longitudinal stability, it is necessary to set the forward stabilizer at about 15°. Such a large angle of incidence results in a very poor lift-drift ratio (and consequently great loss of efficiency), except at very low velocities compared with the speed of modern aeroplanes. At the time such aeroplanes were built velocities were comparatively low, and this defect was, for that reason, not sufficiently appreciated. In the end it killed the "canard" or "tail-first" design. Aeroplanes of the Dunne and similar types possess no stabilizing surface distinct from the main surface, but they have a longitudinal dihedral which renders them stable. The main surface towards the wing-tips is given a decreasing angle of incidence and corresponding camber. The wing-tips then act as longitudinal stabilizers. [Illustration] This design of aeroplane, while very interesting, has not proved very practicable, owing to the following disadvantages: (1) The plan design is not, from a mechanical point of view, so sound as that of the ordinary aeroplane surface, which is, in plan, a parallelogram. It is, then, necessary to make the strength of construction greater than would otherwise be the case. That means extra weight. (2) The plan of the surface area is such that the aspect ratio is not so high as if the surface was arranged with its leading edges at right angles to the direction of motion. The lower the aspect ratio, then, the less the lift. This design, then, produces less lift for weight of surface than would the same surface if arranged as a parallelogram. (3) In order to secure the longitudinal dihedral, the angle of incidence has to be very much decreased towards the wing-tips. Then, in order that the lift-drift ratio may be preserved, there must be a corresponding decrease in the camber. That calls for surface ribs of varying cambers, and results in an expensive and lengthy job for the builder. (4) In order to secure directional stability, the surface is, in the centre, arranged to dip down in the form of a V, pointing towards the direction of motion. Should the aeroplane turn off its course, then its momentum in the direction of its first course causes it to move in a direction the resultant of the thrust and the momentum. It then moves in a more or less sideways attitude, which results in an air pressure upon one side of the V, and which tends to turn the aeroplane back to its first course. This arrangement of the surface results in a bad drift. Vertical surfaces at the wing-tips may also be set at an angle producing the same stabilizing effect, but they also increase the drift. The gyroscopic action of a rotary engine will affect the longitudinal stability when an aeroplane is turned to right or left. In the case of a Gnome engine, fitted to a "pusher" aeroplane, such gyroscopic action will tend to depress the nose of the aeroplane when it is turned to the left, and to elevate it when it is turned to the right. When fitted to a "tractor" aeroplane, the engine is reversed so that a reverse condition results. In modern aeroplanes this tendency is not sufficiently important to bother about, except in the matter of spiral descents (see section headed "Spinning"). In the old days of crudely designed and under-powered "pusher" aeroplanes this gyroscopic action was very marked, and led the majority of pilots to dislike turning an aeroplane to the right, since, in doing so, there was some danger of "stalling." LATERAL STABILITY is far more difficult for the designer to secure than is longitudinal or directional stability. Some degree of lateral stability may be secured by means of the "lateral dihedral," _i.e._, the upward inclination of the surface towards its wing-tips thus: [Illustration] Imagine the top =V=, illustrated opposite, to be the front view of a surface flying towards you. The horizontal equivalent (H.E.) of the left wing is the same as that of the right wing. Therefore, the lift of one wing is equal to the lift of the other, and the weight, being situated always in the centre, is balanced. If some movement of the air causes the surface to tilt sideways, as in the lower illustration, then you will note that the H.E. of the left wing increases, and the H.E. of the right wing decreases. The left wing then, having the greatest lift, rises; and the surface assumes its first and normal position. Unfortunately, however, the righting effect is not proportional to the difference between the right and left H.E.'s. [Illustration: R, Direction of reaction of wing indicated. R R, Resultant direction of reaction of both wings. M, Horizontal (sideway) component of reaction. L, Vertical component of reaction (lift).] In the case of A, the resultant direction of the reaction of both wings is opposed to the direction of gravity or weight. The two forces R R and gravity are then evenly balanced, and the surface is in a state of equilibrium. In the case of B, you will note that the R R is not directly opposed to gravity. This results in the appearance of M, and so the resultant direction of motion of the aeroplane is no longer directly forward, but is along a line the resultant of the Thrust and M. In other words, it is, while flying forward, at the same time moving sideways in the direction M. In moving sideways, the keel-surface receives, of course, a pressure from the air equal and opposite to M. Since such surface is greatest in effect towards the tail, then the latter must be pushed sideways. That causes the aeroplane to turn; and, the highest wing being on the outside of the turn, it has a greater velocity than the lower wing. That produces greater lift, and tends to tilt the aeroplane over still more. Such tilting tendency is, however, opposed by the difference in the H.E.'s of the two wings. It then follows that, for the lateral dihedral angle to be effective, such angle must be large enough to produce, when the aeroplane tilts, a difference in the H.E.'s of the two wings, which difference must be sufficient to not only oppose the tilting tendency due to the aeroplane turning, but sufficient to also force the aeroplane back to its original position of equilibrium. It is now, I hope, clear to the reader that the lateral dihedral is not quite so effective as would appear at first sight. Some designers, indeed, prefer not to use it, since its effect is not very great, and since it must be paid for in loss of H.E. and consequently loss of lift, thus decreasing the lift-drift ratio, _i.e._, the efficiency. Also, it is sometimes advanced that the lateral dihedral increases the "spill" of air from the wing-tips and that this adversely affects the lift-drift ratio. _The disposition of the keel-surface_ affects the lateral stability. It should be, in effect, equally divided by the longitudinal turning axis of the aeroplane. If there is an excess of keel-surface above or below such axis, then a side gust striking it will tend to turn the aeroplane over sideways. _The position of the centre of gravity_ affects lateral stability. If too low, it produces a pendulum effect and causes the aeroplane to roll sideways. If too high, it acts as a stick balanced vertically would act. If disturbed, it tends to travel to a position as far as possible from its original position. It would then tend, when moved, to turn the aeroplane over sideways and into an upside-down position. From the point of view of lateral stability, the best position for the centre of gravity is one a little below the centre of drift. This produces a little lateral stability without any marked pendulum effect. _Propeller torque_ affects lateral stability. An aeroplane tends to turn over sideways in the opposite direction to which the propeller revolves. [Illustration] This tendency is offset by increasing the angle of incidence (and consequently the lift) of the side tending to fall; and it is always advisable, if practical considerations allow it, to also decrease the angle upon the other side. In that way it is not necessary to depart so far from the normal angle of incidence at which the lift-drift ratio is highest. _Wash-in_ is the term applied to the increased angle. _Wash-out_ is the term applied to the decreased angle. Both lateral and directional stability may be improved by washing out the angle of incidence on both sides of the surface, thus: [Illustration] The decreased angle decreases the drift and therefore the effect of gusts upon the wing-tips, which is just where they have the most effect upon the aeroplane, owing to the distance from the turning axis. The wash-out also renders the ailerons (lateral controlling services) more effective, as, in order to operate them, it is not then necessary to give them such a large angle of incidence as would otherwise be required. [Illustration: Note: Observe that the inclination of the ailerons to the surface is the same in each case.] The less the angle of incidence of the ailerons, the better their lift-drift ratio, i.e., their efficiency. You will note that, while the aileron attached to the surface with washed-out angle is operated to the same extent as the aileron illustrated above it, its angle of incidence is considerably less. Its efficiency is therefore greater. The advantages of the wash-in must, of course, be paid for in some loss of lift, as the lift decreases with the decreased angle. In order to secure all the above described advantages, a combination is sometimes effected, thus: [Illustration: "Wash Out" on both sides relative to the Centre.] BANKING.--An aeroplane turned off its course to right or left does not at once proceed along its new course. Its momentum in the direction of its first course causes it to travel along a line the resultant of such momentum and the thrust. In other words, it more or less skids sideways and away from the centre of the turn. Its lifting surfaces do not then meet the air in their correct attitude, and the lift may fall to such an extent as to become less than the weight, in which case the aeroplane must fall. This bad effect is minimized by "banking," _i.e._, tilting the aeroplane sideways. The bottom of the lifting surface is in that way opposed to the air through which it is moving in the direction of the momentum and receives an opposite air pressure. The rarefied area over the top of the surface is rendered still more rare, and this, of course, assists the air pressure in opposing the momentum. The velocity of the "skid," or sideways movement, is then only such as is necessary to secure an air pressure equal and opposite to the centrifugal force of the turn. The sharper the turn, the greater the effect of the centrifugal force, and therefore the steeper should be the "bank." _Experientia docet_. _The position of the centre of gravity_ affects banking. A low C.G. will tend to swing outward from the centre of the turn, and will cause the aeroplane to bank--perhaps too much, in which case the pilot must remedy matters by operating the ailerons. A high C.G. also tends to swing outward from the centre of the turn. It will tend to make the aeroplane bank the wrong way, and such effect must be remedied by means of the ailerons. The pleasantest machine from a banking point of view is one in which the C.G. is a little below the centre of drift. It tends to bank the aeroplane the right way for the turn, and the pilot can, if necessary, perfect the bank by means of the ailerons. _The disposition of the keel-surface_ affects banking. It should be, in effect, evenly divided by the longitudinal axis. An excess of keel-surface above the longitudinal axis will, when banking, receive an air pressure causing the aeroplane to bank, perhaps too much. An excess of keel-surface below the axis has the reverse effect. SIDE-SLIPPING.--This usually occurs as a result of over-banking. It is always the result of the aeroplane tilting sideways and thus decreasing the horizontal equivalent, and therefore the lift, of the surface. An excessive "bank," or sideways tilt, results in the H.E., and therefore the lift, becoming less than the weight, when, of course, the aeroplane must fall, _i.e._, side-slip. [Illustration] When making a very sharp turn it is necessary to bank very steeply indeed. If, at the same time, the longitudinal axis of the aeroplane remains approximately horizontal, then there must be a fall, and the direction of motion will be the resultant of the thrust and the fall as illustrated above in sketch A. The lifting surfaces and the controlling surfaces are not then meeting the air in the correct attitude, with the result that, in addition to falling, the aeroplane will probably become quite unmanageable. The pilot, however, prevents such a state of affairs from happening by "nosing-down," _i.e._, by operating the rudder to turn the nose of the aeroplane downward and towards the direction of motion as illustrated in sketch B. This results in the higher wing, which is on the outside of the turn, travelling with greater velocity, and therefore securing a greater reaction than the lower wing, thus tending to tilt the aeroplane over still more. The aeroplane is now almost upside-down, _but_ its attitude relative to the direction of motion is correct and the controlling surfaces are all of them working efficiently. The recovery of a normal attitude relative to the Earth is then made as illustrated in sketch C. The pilot must then learn to know just the angle of bank at which the margin of lift is lost, and, if a sharp turn necessitates banking beyond that angle, he must "nose-down." In this matter of banking and nosing-down, and, indeed, regarding stability and control generally, the golden rule for all but very experienced pilots should be: _Keep the aeroplane in such an attitude that the air pressure is always directly in the pilot's face._ The aeroplane is then always engaging the air as designed to do so, and both lifting and controlling surfaces are acting efficiently. The only exception to this rule is a vertical dive, and I think that is obviously not an attitude for any but very experienced pilots to hanker after. SPINNING.--This is the worst of all predicaments the pilot can find himself in. Fortunately it rarely happens. It is due to the combination of (1) a very steep spiral descent of small radius, and (2) insufficiency of keel-surface behind the vertical axis, or the jamming of the rudder and/or elevator into a position by which the aeroplane is forced into an increasingly steep and small spiral. Owing to the small radius of such a spiral, the mass of the aeroplane may gain a rotary momentum greater, in effect, than the air pressure of the keel-surface or controlling surfaces opposed to it; and, when once such a condition occurs, it is difficult to see what can be done by the pilot to remedy it. The sensible pilot will not go beyond reasonable limits of steepness and radius when executing spiral descents. [Illustration: Nose Dive Spin.] In this connection every pilot of an aeroplane fitted with a rotary engine should bear in mind the gyroscopic effect of such engine. In the case of such an engine fitted to a "pusher" aeroplane, its effect when a left-hand turn is made is to depress the nose of the machine. If fitted to a "tractor" it is reversed, so the effect is to depress the nose if a right-hand turn is made. The sharper the turn, the greater such effect--an effect which may render the aeroplane unmanageable if the spiral is one of very small radius and the engine is revolving with sufficient speed to produce a material gyroscopic effect. Such gyroscopic effect should, however, slightly _assist_ the pilot to navigate a small spiral if he will remember to (1) make _right-hand_ spirals in the case of a "pusher," (2) make _left-hand_ spirals in the case of a "tractor." The effect will then be to keep the nose up and prevent a nose-dive. I say "slightly" assist because the engine is, of course, throttled down for a spiral descent, and its lesser revolutions will produce a lesser gyroscopic effect. On the other hand, it might be argued that if the aeroplane gets into a "spin," anything tending to depress the nose of the machine is of value, since it is often claimed that the best way to get out of a spin is to put the machine into a nose-dive--the great velocity of the dive rendering the controls more efficient and better enabling the pilot to regain control. It is, however, a very contentious point, and few are able to express opinions based on practice, since pilots indulging in nose-dive spins are either not heard of again or have usually but a hazy recollection of exactly what happened to them. GLIDING DESCENT WITHOUT PROPELLER THRUST.--All aeroplanes are, or should be, designed to assume their correct gliding angle when the power and thrust is cut off. This relieves the pilot of work, worry, and danger should he find himself in a fog or cloud. The pilot, although he may not realize it, maintains the correct attitude of the aeroplane by observing its position relative to the horizon. Flying into a fog or cloud the horizon is lost to view, and he must then rely upon his instruments--(1) the compass for direction; (2) an inclinometer (arched spirit-level) mounted transversely to the longitudinal axis, for lateral stability; and (3) an inclinometer mounted parallel to the longitudinal axis, or the airspeed indicator, which will indicate a nose-down position by increase in air speed, and a tail-down position by decrease in air speed. The pilot is then under the necessity of watching three instruments and manipulating his three controls to keep the instruments indicating longitudinal, lateral, and directional stability. That is a feat beyond the capacity of the ordinary man. If, however, by the simple movement of throttling down the power and thrust, he can be relieved of looking after the longitudinal stability, he then has only two instruments to watch. That is no small job in itself, but it is, at any rate, fairly practicable. [Illustration] Aeroplanes are, then, designed, or should be, so that the centre of gravity is slightly forward of centre of lift. The aeroplane is then, as a glider, nose-heavy--and the distance the C.G. is placed in advance of the C.L. should be such as to ensure a gliding angle producing a velocity the same as the normal flying speed (for which the strength of construction has been designed). In order that this nose-heavy tendency should not exist when the thrust is working and descent not required, the centre of thrust is placed a little below the centre of drift or resistance, and thus tends to pull up the nose of the aeroplane. The distance the centre of thrust is placed below the centre of drift should be such as to produce a force equal and opposite to that due to the C.G. being forward of the C.L. (see illustration above). LOOPING AND UPSIDE-DOWN FLYING.--If a loop is desired, it is best to throttle the engine down at point A. The C.G. being forward of the C.P., then causes the aeroplane to nose down, and assists the pilot in making a reasonably small loop along the course C and in securing a quick recovery. If the engine is not throttled down, then the aeroplane may be expected to follow the course D, which results in a longer nose dive than in the case of the course C. [Illustration: Position A. Path B. Path C. Path D.] A steady, gentle movement of the elevator is necessary. A jerky movement may change the direction of motion so suddenly as to produce dangerous air stresses upon the surfaces, in which case there is a possibility of collapse. If an upside-down flight is desired, the engine may, or may not, be throttled down at point A. If not throttled down, then the elevator must be operated to secure a course approximately in the direction B. If it is throttled down, then the course must be one of a steeper angle than B, or there will be danger of stalling. [Footnote 16: "In effect" because, although there may be actually the greatest proportion of keel-surface in front of the vertical axis, such surface may be much nearer to the axis than is the keel-surface towards the tail. The latter may then be actually less than the surface in front, but, being farther from the axis, it has a greater leverage, and consequently is greater in effect than the surface in front.] [Footnote 17: The reason the C.P. of an inclined surface is forward of the centre of the surface is because the front of the surface does most of the work, as explained on p. 62.] CHAPTER III RIGGING In order to rig an aeroplane intelligently, and to maintain it in an efficient and safe condition, it is necessary to possess a knowledge of the stresses it is called upon to endure, and the strains likely to appear. STRESS is the load or burden a body is called upon to bear. It is usually expressed by the result found by dividing the load by the number of superficial square inches contained in the cross-sectional area of the body. [Illustration: Cross Sectional area] Thus, if, for instance, the object illustrated above contains 4 square inches of cross-sectional area, and the total load it is called upon to endure is 10 tons, the stress would be expressed as 2-1/2 tons. STRAIN is the deformation produced by stress. THE FACTOR OF SAFETY is usually expressed by the result found by dividing the stress at which it is known the body will collapse by the maximum stress it will be called upon to endure. For instance, if a control wire be called upon to endure a maximum stress of 2 cwts., and the known stress at which it will collapse is 10 cwts., the factor of safety is then 5. COMPRESSION.--The simple stress of compression tends to produce a crushing strain. Example: the interplane and fuselage struts. TENSION.--The simple stress of tension tends to produce the strain of elongation. Example: all the wires. BENDING.--The compound stress of bending is a combination of compression and tension. [Illustration] The above sketch illustrates a straight piece of wood of which the top, centre, and bottom lines are of equal length. We will now imagine it bent to form a circle, thus: [Illustration] The centre line is still the same length as before being bent; but the top line, being farther from the centre of the circle, is now longer than the centre line. That can be due only to the strain of elongation produced by the stress of tension. The wood between the centre line and the top line is then in tension; and the farther from the centre, the greater the strain, and consequently the greater the tension. The bottom line, being nearest to the centre of the circle, is now shorter than the centre line. That can be due only to the strain of crushing produced by the stress of compression. The wood between the centre and bottom lines is then in compression; and the nearer the centre of the circle, the greater the strain, and consequently the greater the compression. It then follows that there is neither tension nor compression, _i.e._, no stress, at the centre line, and that the wood immediately surrounding it is under considerably less stress than the wood farther away. This being so, the wood in the centre may be hollowed out without unduly weakening struts and spars. In this way 25 to 33 per cent. is saved in the weight of wood in an aeroplane. The strength of wood is in its fibres, which should, as far as possible, run without break from one end of a strut or spar to the other end. A point to remember is that the outside fibres, being farthest removed from the centre line, are doing by far the greatest work. SHEAR STRESS is such that, when material collapses under it, one part slides over the other. Example: all the locking pins. [Illustration] Some of the bolts are also in shear or "sideways" stress, owing to lugs under their heads and from which wires are taken. Such a wire, exerting a sideways pull upon a bolt, tries to break it in such a way as to make one piece of the bolt slide over the other piece. TORSION.--This is a twisting stress compounded of compression, tension, and shear stresses. Example: the propeller shaft. NATURE OF WOOD UNDER STRESS.--Wood, for its weight, takes the stress of compression far better than any other stress. For instance: a walking-stick of less than 1 lb. in weight will, if kept perfectly straight, probably stand up to a compression stress of a ton or more before crushing; whereas, if the same stick is put under a bending stress, it will probably collapse to a stress of not more than about 50 lb. That is a very great difference, and, since weight is of the greatest importance, the design of an aeroplane is always such as to, as far as possible, keep the various wooden parts of its construction in direct compression. Weight being of such vital importance, and designers all trying to outdo each other in saving weight, it follows that the factor of safety is rather low in an aeroplane. The parts in direct compression will, however, take the stresses safely provided the following conditions are carefully observed. CONDITIONS TO BE OBSERVED: 1. _All the spars and struts must be perfectly straight._ [Illustration] The above sketch illustrates a section through an interplane strut. If the strut is to be kept straight, _i.e._, prevented from bending, then the stress of compression must be equally disposed about the centre of strength. If it is not straight, then there will be more compression on one side of the centre of strength than on the other side. That is a step towards getting compression on one side and tension on the other side, in which case it may be forced to take a bending stress for which it is not designed. Even if it does not collapse it will, in effect, become shorter, and thus throw out of adjustment the gap and all the wires attached to the top and bottom of the strut, with the result that the flight efficiency of the aeroplane will be spoiled. [Illustration: Strut straight. Wires and gap correctly adjusted. Strut bent throwing wires and gap out of adjustment.] The only exception to the above condition is what is known as the Arch. For instance, in the case of the Maurice Farman, the spars of the centre-section plane, which have to take the weight of the nacelle, are arched upwards. If this was not done, it is possible that rough landings might result in the weight causing the spars to become slightly distorted downwards. That would produce a dangerous bending stress, but, as long as the wood is arched, or, at any rate, kept from bending downwards, it will remain in direct compression and no danger can result. 2. _Struts and spars must be symmetrical._ By that I mean that the cross-sectional dimensions must be correct, as otherwise there will be bulging places on the outside, with the result that the stress will not be evenly disposed about the centre of strength, and a bending stress may be produced. 3. _Struts, spars, etc., must be undamaged._ Remember that, from what I have already explained about bending stresses, the outside fibres of the wood are doing by far the most work. If these get bruised or scored, then the strut or spar suffers in strength much more than one might think at first sight; and, if it ever gets a tendency to bend, it is likely to collapse at that point. 4. _The wood must have a good, clear grain with no cross-grain, knots, or shakes._ Such blemishes produce weak places and, if a tendency to bend appears, then it may collapse at such a point. [Illustration: Strut bedded properly. Strut bedded badly.] 5. _The struts, spars, etc., must be properly bedded into their sockets or fittings._ To begin with, they must be of good pushing or gentle tapping fit. They must never be driven in with a heavy hammer. Then again, a strut must bed well down all over its cross-sectional area as illustrated above; otherwise the stress of compression will not be evenly disposed about the centre of strength, and that may produce a bending stress. The bottom of the strut or spar should be covered with some sort of paint, bedded into the socket or fitting, and then withdrawn to see if the paint has stuck all over the bed. 6. The atmosphere is sometimes much damper than at other times, and this causes wood to expand and contract appreciably. This would not matter but for the fact that it does not expand and contract uniformly, but becomes unsymmetrical, _i.e._, distorted. I have already explained the danger of that in condition 2. This should be minimized by _well varnishing the wood_ to keep the moisture out of it. FUNCTION OF INTERPLANE STRUTS.--These struts have to keep the lifting surfaces or "planes" apart, but this is only part of their work. They must keep the planes apart, so that the latter are in their correct attitude. That is only so when the spars of the bottom plane are parallel with those of the top plane. Also, the chord of the top plane must be parallel with the chord of the bottom plane. If that is not so, then one plane will not have the same angle of incidence as the other one. At first sight one might think that all that is necessary is to cut all the struts to be the same length, but that is not the case. [Illustration] Sometimes, as illustrated above, the rear spar is not so thick as the main spar, and it is then necessary to make up for that difference by making the rear struts correspondingly longer. If that is not done, then the top and bottom chords will not be parallel, and the top and bottom planes will have different angles of incidence. Also, the sockets or fittings, or even the spars upon which they are placed, sometimes vary in thickness owing to faulty manufacture. This must be offset by altering the length of the struts. The best way to proceed is to measure the distance between the top and bottom spars by the side of each strut, and if that distance, or "gap" as it is called, is not as stated in the aeroplane's specifications, then make it correct by changing the length of the strut. This applies to both front and rear interplane struts. When measuring the gap, always be careful to measure from the centre of the spar, as it may be set at an angle, and the rear of it may be considerably lower than its front. BORING HOLES IN WOOD.--It should be a strict rule that no spar be used which has an unnecessary hole in it. Before boring a hole, its position should be confirmed by whoever is in charge of the workshop. A bolt-hole should be of a size to enable the bolt to be pushed in, or, at any rate, not more than gently tapped in. Bolts should not be hammered in, as that may split the spar. On the other hand, a bolt should not be slack in its hole, as, in such a case, it may work sideways and split the spar, not to speak of throwing out of adjustment the wires leading from the lug or socket under the bolt-head. WASHERS.--Under the bolt-head, and also under the nut, a washer must be placed--a very large washer compared with the size which would be used in all-metal construction. This is to disperse the stress over a large area; otherwise the washer may be pulled into the wood and weaken it, besides possibly throwing out of adjustment the wires attached to the bolt or the fitting it is holding to the spar. LOCKING.--Now as regards locking the bolts. If split pins are used, be sure to see that they are used in such a way that the nut cannot possibly unscrew at all. The split pin should be passed through the bolt as near as possible to the nut. It should not be passed through both nut and bolt. If it is locked by burring over the edge of the bolt, do not use a heavy hammer and try to spread the whole head of the bolt. That might damage the woodwork inside the fabric-covered surface. Use a small, light hammer, and gently tap round the edge of the bolt until it is burred over. TURNBUCKLES.--A turnbuckle is composed of a central barrel into each end of which is screwed an eye-bolt. Wires are taken from the eyes of the eye-bolt, and so, by turning the barrel, they can be adjusted to their proper tension. Eye-bolts must be a good fit in the barrel; that is to say, not slack and not very tight. Theoretically it is not necessary to screw the eye-bolt into the barrel for a distance greater than the diameter of the bolt, but, in practice, it is better to screw it in for a considerably greater distance than that if a reasonable degree of safety is to be secured. Now about turning the barrel to secure the right adjustment. The barrel looks solid, but, as a matter of fact, it is hollow and much more frail than it appears. For that reason it should not be turned by seizing it with pliers, as that may distort it and spoil the bore within it. The best method is to pass a piece of wire through the hole in its centre, and to use that as a lever. When the correct adjustment has been secured, the turnbuckle must be locked to prevent it from unscrewing. It is quite possible to lock it in such a way as to allow it to unscrew a quarter or a half turn, and that would throw the wires out of the very fine adjustment necessary. The proper way is to use the locking wire so that its direction is such as to oppose the tendency of the barrel to unscrew, thus: [Illustration] WIRES.--The following points should be carefully observed where wire is concerned: 1. _Quality._--It must not be too hard or too soft. An easy practical way of learning to know the approximate quality of wire is as follows: Take three pieces, all of the same gauge, and each about a foot in length. One piece should be too soft, another too hard, and the third piece of the right quality. Fix them in a vice, about an inch apart and in a vertical position, and with the light from a window shining upon them. Burnish them if necessary, and you will see a band of light reflected from each wire. Now bend the wires over as far as possible and away from the light. Where the soft wire is concerned, it will squash out at the bend, and this will be indicated by the band of light, which will broaden at that point. In the case of the wire which is too hard, the band of light will broaden very little at the turn, but, if you look carefully, you will see some little roughness of surface. In the case of the wire of the right quality, the band of light may broaden a very little at the turn, but there will be no roughness of surface. By making this experiment two or three times one can soon learn to know really bad wire from good, and also learn to know the strength of hand necessary to bend the right quality. 2. _It must not be damaged._ That is to say, it must be unkinked, rustless, and unscored. 3. Now as regards keeping wire in good condition. Where outside wires are concerned, they should be kept _well greased or oiled_, especially where bent over at the ends. Internal bracing wires cannot be reached for the purpose of regreasing them, as they are inside fabric-covered surfaces. They should be prevented from rusting by being painted with an anti-rust mixture. Great care should be taken to see that the wire is perfectly clean and dry before being painted. A greasy finger-mark is sufficient to stop the paint from sticking to the wire. In such a case there will be a little space between the paint and the wire. Air may enter there and cause the wire to rust. 4. _Tension of Wires._--The tension to which the wires are adjusted is of the greatest importance. All the wires should be of the same tension when the aeroplane is supported in such a way as to throw no stress upon them. If some wires are in greater tension than others, the aeroplane will quickly become distorted and lose its efficiency. In order to secure the same tension of all wires, the aeroplane, when being rigged, should be supported by packing underneath the lower surfaces as well as by packing underneath the fuselage or nacelle. In this way the anti-lift wires are relieved of the weight, and there is no stress upon any of the wires. As a general rule the wires of an aeroplane are tensioned too much. The tension should be sufficient to keep the framework rigid. Anything more than that lowers the factor of safety, throws various parts of the framework into undue compression, pulls the fittings into the wood, and will, in the end, distort the whole framework of the aeroplane. Only experience will teach the rigger what tension to employ. Much may be done by learning the construction of the various types of aeroplanes, the work the various parts do, and in cultivating a touch for tensioning wires by constantly handling them. 5. _Wires with no Opposition Wires._--In some few cases wires will be found which have no opposition wires pulling in the opposite direction. For instance, an auxiliary lift wire may run from the bottom of a strut to a spar in the top plane at a point between struts. In such a case great care should be taken not to tighten the wire beyond barely taking up the slack. [Illustration: Distortion of upper wing caused by auxiliary lift wire being too tight.] Such a wire must be a little slack, or, as illustrated above, it will distort the framework. That, in the example given, will spoil the camber (curvature) of the surface, and result in changing both the lift and the drift at that part of the surface. Such a condition will cause the aeroplane to lose its directional stability and also to fly one wing down. I cannot impress this matter of tension upon the reader too strongly. It is of the utmost importance. When this, and also accuracy in securing the various adjustments, has been learned, one is on the way to becoming a good rigger. 6. _Wire Loops._--Wire is often bent over at its end in the form of a loop, in order to connect with a turnbuckle or fitting. These loops, even when made as perfectly as possible, have a tendency to elongate, thus spoiling the adjustment of the wires. Great care should be taken to minimize this as much as possible. The rules to be observed are as follows: [Illustration: Wrong shape. Result of wrong shape. Right Shape.] (_a_) The size of the loop should be as small as possible within reason. By that I mean it should not be so small as to create the possibility of the wire breaking. (_b_) The shape of the loop should be symmetrical. (_c_) It should have well-defined shoulders in order to prevent the ferrule from slipping up. At the same time, a shoulder should not have an angular place. (_d_) When the loop is finished it should be undamaged, and it should not be, as is often the case, badly scored. 7. _Stranded Wire Cable._--No splice should be served with twine until it has been inspected by whoever is in charge of the workshop. The serving may cover bad work. Should a strand become broken, then the cable should be replaced at once by another one. Control cables have a way of wearing out and fraying wherever they pass round pulleys. Every time an aeroplane comes down from flight the rigger should carefully examine the cables, especially where they pass round pulleys. If he finds a strand broken, he should replace the cable. The ailerons' balance cable on the top of the top plane is often forgotten, since it is necessary to fetch a high pair of steps in order to examine it. Don't slack this, or some gusty day the pilot may unexpectedly find himself minus the aileron control. CONTROLLING SURFACES.--The greatest care should be exercised in rigging the aileron, rudder, and elevator properly, for the pilot entirely depends upon them in managing the aeroplane. [Illustration: Position in which controlling surface must be rigged. It will be its position during flight.] The ailerons and elevator should be rigged so that, when the aeroplane is in flight, they are in a fair true line with the surface in front and to which they are hinged. [Illustration: Position during flight. Position in which controlling surface must be rigged.] If the surface to which they are hinged is not a lifting surface, then they should be rigged to be in a fair true line with it as illustrated above. If the controlling surface is, as illustrated, hinged to the back of a lifting surface, then it should be rigged a little below the position it would occupy if in a fair true line with the surface in front. This is because, in such a case, it is set at an angle of incidence. This angle will, during flight, cause it to lift a little above the position in which it has been rigged. It is able to lift owing to a certain amount of slack in the control wire holding it--and one cannot adjust the control wire to have no slack, because that would cause it to bind against the pulleys and make the operation of it too hard for the pilot. It is therefore necessary to rig it a little below the position it would occupy if it was rigged in a fair true line with the surface in front. Remember that this only applies when it is hinged to a lifting surface. The greater the angle of incidence (and therefore the lift) of the surface in front, then the more the controlling surface will have to be rigged down. As a general rule it is safe to rig it down so that its trailing edge is 1/2 to 3/4 inch below the position it would occupy if in a fair line with the surface in front; or about 1/2 inch down for every 18 inches of chord of the controlling surface. When making these adjustments the pilot's control levers should be in their neutral positions. It is not sufficient to lash them. They should be rigidly blocked into position with wood packing. The surfaces must not be distorted in any way. If they are held true by bracing wires, then such wires must be carefully adjusted. If they are distorted and there are no bracing wires with which to true them, then some of the internal framework will probably have to be replaced. The controlling surfaces should never be adjusted with a view to altering the stability of the aeroplane. Nothing can be accomplished in that way. The only result will be to spoil the control of the aeroplane. FABRIC-COVERED SURFACES.--First of all make sure that there is no distortion of spars or ribs, and that they are perfectly sound. Then adjust the internal bracing wires so that the ribs are parallel to the direction of flight. The ribs usually cause the fabric to make a ridge where they occur, and, if such ridge is not parallel to the direction of flight, it will produce excessive drift. As a rule the ribs are at right angles to both main and rear spars. The tension of the internal bracing wires should be just sufficient to give rigidity to the framework. They should not be tensioned above that unless the wires are, at their ends, bent to form loops. In that case a little extra tension may be given to offset the probable elongation of the loops. The turnbuckles must now be generously greased, and served round with adhesive tape. The wires must be rendered perfectly dry and clean, and then painted with an anti-rust mixture. The woodwork must be well varnished. If it is necessary to bore holes in the spars for the purpose of receiving, for instance, socket bolts, then their places should be marked before being bored and their positions confirmed by whoever is in charge of the workshop. All is now ready for the sail-maker to cover the surface with fabric. ADJUSTMENT OF CONTROL CABLES.--The adjustment of the control cables is quite an art, and upon it will depend to a large degree the quick and easy control of the aeroplane by the pilot. The method is as follows: After having rigged the controlling surfaces, and as far as possible secured the correct adjustment of the control cables, then remove the packing which has kept the control levers rigid. Then, sitting in the pilot's seat, move the control levers _smartly_. Tension the control cables so that when the levers are smartly moved there is no perceptible snatch or lag. Be careful not to tension the cables more than necessary to take out the snatch. If tensioned too much they will (1) bind round the pulleys and result in hard work for the pilot; (2) throw dangerous stresses upon the controlling surfaces, which are of rather flimsy construction; and (3) cause the cables to fray round the pulleys quicker than would otherwise be the case. Now, after having tensioned the cables sufficiently to take out the snatch, place the levers in their neutral positions, and move them to and fro about 1/8 inch either side of such positions. If the adjustment is correct, it should be possible to see the controlling surfaces move. If they do not move, then the control cables are too slack. FLYING POSITION.--Before rigging an aeroplane or making any adjustments it is necessary to place it in what is known as its "flying position." I may add that it would be better termed its "rigging position." In the case of an aeroplane fitted with a stationary engine this is secured by packing up the machine so that the engine foundations are perfectly horizontal both longitudinally and laterally. This position is found by placing a straight-edge and a spirit-level across the engine foundations (both longitudinally and laterally), and great care should be taken to see that the bubble is exactly in the centre of the level. The slightest error will assume magnitude towards the extremities of the aeroplane. Great care should be taken to block up the aeroplane rigidly. In case it gets accidentally disturbed while the work is going on, it is well to constantly verify the flying position by running the straight-edge and spirit-level over the engine foundations. The straight-edge should be carefully tested before being used, as, being generally made of wood, it will not remain true long. Place it lightly in a vice, and in such a position that a spirit-level on top shows the bubble exactly in the centre. Now slowly move the level along the straight-edge, and the bubble should remain exactly in the centre. If it does not do so, then the straight-edge is not true and must be corrected. _This should never be omitted._ In the case of aeroplanes fitted with engines of the rotary type, the "flying position" is some special attitude laid down in the aeroplane's specifications, and great care should be taken to secure accuracy. ANGLE OF INCIDENCE.--One method of finding the angle of incidence is as follows: [Illustration] First place the aeroplane in its flying position. The corner of the straight-edge must be placed underneath and against the _centre_ of the rear spar, and held in a horizontal position parallel to the ribs. This is secured by using a spirit-level. The set measurement will then be from the top of the straight-edge to the centre of the bottom surface of the main spar, or it may be from the top of the straight-edge to the lowest part of the leading edge. Care should be taken to measure from the centre of the spar and to see that the bubble is exactly in the centre of the level. Remember that all this will be useless if the aeroplane has not been placed accurately in its flying position. This method of finding the angle of incidence must be used under every part of the lower surface where struts occur. It should not be used between the struts, because, in such places, the spars may have taken a slight permanent set up or down; not, perhaps, sufficiently bad to make any material difference to the flying of the machine, but quite bad enough to throw out the angle of incidence, which cannot be corrected at such a place. If the angle is wrong, it should then be corrected as follows: If it is too great, then the rear spar must be warped up until it is right, and this is done by slackening _all_ the wires going to the top of the strut, and then tightening _all_ the wires going to the bottom of the strut. If the angle is too small, then slacken _all_ the wires going to the bottom of the strut, and tighten _all_ the wires going to the top of the strut, until the correct adjustment is secured. Never attempt to adjust the angle by warping the main spar. The set measurement, which is of course stated in the aeroplane's specifications, should be accurate to 1/16 inch. LATERAL DIHEDRAL ANGLE.--One method of securing this is as follows, and this method will, at the same time, secure the correct angle of incidence: [Illustration: FRONT ELEVATION and PLAN.] The strings, drawn very tight, must be taken over both the main and rear spars of the top surface. They must run between points on the spars just inside the outer struts. The set measurement (which should be accurate to 1/16 inch or less) is then from the strings down to four points on the main and rear spars of the centre-section surface. These points should be just inside the four centre-section struts; that is to say, as far as possible away from the centre of the centre-section. Do not attempt to take the set measurement near the centre of the centre-section. The strings should be as tight as possible, and, if it can be arranged, the best way to accomplish that is as shown in the above illustration, _i.e._, by weighting the strings down to the spars by means of weights and tying their ends to struts. This will give a tight and motionless string. However carefully the above adjustment is made, there is sure to be some slight error. This is of no great importance, provided it is divided equally between the left- and right-hand wings. In order to make sure of this, certain check measurements should be taken as follows: Each bay must be diagonally measured, and such measurements must be the same to within 1/16 inch on each side of the aeroplane. As a rule such diagonal measurements are taken from the bottom socket of one strut to the top socket of another strut, but this is bad practice, because of possible inaccuracies due to faulty manufacture. The points between which the diagonal measurements are taken should be at fixed distances from the butts of the spars, such distances being the same on each side of the aeroplane, thus: [Illustration: Points A, B, and C, must be the same fixed distances from the butt as are Points D, E, and F. Distances 1 and 2 must equal distances 3 and 4.] The above applies to both front and rear bays. It would be better to use the centre line of the aeroplane rather than the butts of the spars. It is not practicable to do so, however, as the centre line probably runs through the petrol tanks, etc. THE DIHEDRAL BOARD.--Another method of securing the dihedral angle, and also the angle of incidence, is by means of the dihedral board. It is a light handy thing to use, but leads to many errors, and should not be used unless necessary. The reasons are as follows: The dihedral board is probably not true. If it must be used, then it should be very carefully tested for truth beforehand. Another reason against its use is that it has to be placed on the spars in a position between the struts, and that is just where the spars may have a little permanent set up or down, or some inaccuracy of surface which will, of course, throw out the accuracy of the adjustment. The method of using it is as follows: [Illustration] The board is cut to the same angle as that specified for the upward inclination of the surface towards its wing-tips. It is placed on the spar as indicated above, and it is provided with two short legs to raise it above the flanges of the ribs (which cross over the spars), as they may vary in depth. A spirit-level is then placed on the board, and the wires must be adjusted to give the surface such an inclination as to result in the bubble being in the centre of the level. This operation must be performed in respect of each bay both front and rear. The bays must then be diagonally measured as already explained. YET ANOTHER METHOD of finding the dihedral angle, and at the same time the angle of incidence, is as follows: A horizontal line is taken from underneath the butt of each spar, and the set measurement is either the angle it makes with the spar, or a fixed measurement from the line to the spar taken at a specified distance from the butt. This operation must be performed in respect of both main and rear spars, and all the bays must be measured diagonally afterwards. [Illustration] Whichever method is used, be sure that after the job is done the spars are perfectly straight. STAGGER.--The stagger is the distance the top surface is in advance of the bottom surface when the aeroplane is in flying position. The set measurement is obtained as follows: [Illustration] Plumb-lines must be dropped over the leading edge of the top surface wherever struts occur, and also near the fuselage. The set measurement is taken from the front of the lower leading edge to the plumb-lines. It makes a difference whether the measurement is taken along a horizontal line (which can be found by using a straight-edge and a spirit-level) or along a projection of the chord. The line along which the measurement should be taken is laid down in the aeroplane's specifications. If a mistake is made and the measurement taken along the wrong line, it may result in a difference of perhaps 1/4 inch or more to the stagger, with the certain result that the aeroplane will, in flight, be nose-heavy or tail-heavy. After the adjustments of the angles of incidence, dihedral, and stagger have been secured, it is as well to confirm all of them, as, in making the last adjustment, the first one may have been spoiled. OVER-ALL ADJUSTMENTS.--The following over-all check measurements should now be taken. [Illustration: The dotted lines on the surface represent the spars within it.] The straight lines AC and BC should be equal to within 1/8 inch. The point C is the centre of the propeller, or, in the case of a "pusher" aeroplane, the centre of the nacelle. The points A and B are marked on the main spar, and must in each case be the same distance from the butt of the spar. The rigger should not attempt to make A and B merely the sockets of the outer struts, as they may not have been placed quite accurately by the manufacturer. The lines AC and BC must be taken from both top and bottom spars--two measurements on each side of the aeroplane. The two measurements FD and FE should be equal to within 1/8 inch. F is the centre of the fuselage or rudder-post. D and E are points marked on both top and bottom rear spars, and each must be the same fixed distance from the butt of the spar. Two measurements on each side of the aeroplane. If these over-all measurements are not correct, then it is probably due to some of the drift or anti-drift wires being too tight or too slack. It may possibly be due to the fuselage being out of truth, but of course the rigger should have made quite sure that the fuselage was true before rigging the rest of the machine. Again, it may be due to the internal bracing wires within the lifting surfaces not being accurately adjusted, but of course this should have been seen to before covering the surfaces with fabric. FUSELAGE.--The method of truing the fuselage is laid down in the aeroplane's specifications. After it has been adjusted according to the specified directions, it should then be arranged on trestles in such a way as to make about three-quarters of it towards the tail stick out unsupported. In this way it will assume a condition as near as possible to flying conditions, and when it is in this position the set measurements should be confirmed. If this is not done it may be out of truth, but perhaps appear all right when supported by trestles at both ends, as, in such case, its weight may keep it true as long as it is resting upon the trestles. THE TAIL-PLANE (EMPENNAGE).--The exact angle of incidence of the tail-plane is laid down in the aeroplane's specifications. It is necessary to make sure that the spars are horizontal when the aeroplane is in flying position and the tail unsupported as explained above under the heading of Fuselage. If the spars are tapered, then make sure that their centre lines are horizontal. UNDERCARRIAGE.--The undercarriage must be very carefully aligned as laid down in the specifications. 1. The aeroplane must be placed in its flying position and sufficiently high to ensure the wheels being off the ground when rigged. When in this position the axle must be horizontal and the bracing wires adjusted to secure the various set measurements stated in the specifications. 2. Make sure that the struts bed well down into their sockets. 3. Make sure that the shock absorbers are of equal tension. In the case of rubber shock absorbers, both the number of turns and the lengths must be equal. HOW TO DIAGNOSE FAULTS IN FLIGHT, STABILITY, AND CONTROL. DIRECTIONAL STABILITY will be badly affected if there is more drift (_i.e._, resistance) on one side of the aeroplane than there is on the other side. The aeroplane will tend to turn towards the side having the most drift. This may be caused as follows: 1. The angle of incidence of the main surface or the tail surface may be wrong. The greater the angle of incidence, the greater the drift. The less the angle, the less the drift. 2. If the alignment of the fuselage, fin in front of the rudder, the struts or stream-line wires, or, in the case of the Maurice Farman, the front outriggers, are not absolutely correct--that is to say, if they are turned a little to the left or to the right instead of being in line with the direction of flight--then they will act as a rudder and cause the aeroplane to turn off its course. 3. If any part of the surface is distorted, it will cause the aeroplane to turn off its course. The surface is cambered, _i.e._, curved, to pass through the air with the least possible drift. If, owing perhaps to the leading edge, spars, or trailing edge becoming bent, the curvature is spoiled, that will result in changing the amount of drift on one side of the aeroplane, which will then have a tendency to turn off its course. LATERAL INSTABILITY (FLYING ONE WING DOWN).--The only possible reason for such a condition is a difference in the lifts of right and left wings. That may be caused as follows: 1. The angle of incidence may be wrong. If it is too great, it will produce more lift than on the other side of the aeroplane; and if too small, it will produce less lift than on the other side--the result being that, in either case, the aeroplane will try to fly one wing down. 2. _Distorted Surfaces._--If some part of the surface is distorted, then its camber is spoiled, and the lift will not be the same on both sides of the aeroplane, and that, of course, will cause it to fly one wing down. Longitudinal Instability may be due to the following reasons: 1. _The stagger may be wrong._ The top surface may have drifted back a little owing to some of the wires, probably the incidence wires, having elongated their loops or having pulled the fittings into the wood. If the top surface is not staggered forward to the correct degree, then consequently the whole of its lift is too far back, and it will then have a tendency to lift up the tail of the machine too much. The aeroplane would then be said to be "nose-heavy." A 1/4-inch area in the stagger will make a very considerable difference to the longitudinal stability. 2. If _the angle of incidence_ of the main surface is not right, it will have a bad effect, especially in the case of an aeroplane with a lifting tail-plane. If the angle is too great, it will produce an excess of lift, and that may lift up the nose of the aeroplane and result in a tendency to fly "tail-down." If the angle is too small, it will produce a decreased lift, and the aeroplane may have a tendency to fly "nose-down." 3. _The fuselage_ may have become warped upward or downward, thus giving the tail-plane an incorrect angle of incidence. If it has too much angle, it will lift too much, and the aeroplane will be "nose-heavy." If it has too little angle, then it will not lift enough, and the aeroplane will be "tail-heavy." 4. (The least likely reason.) _The tail-plane_ may be mounted upon the fuselage at a wrong angle of incidence, in which case it must be corrected. If nose-heavy, it should be given a smaller angle of incidence. If tail-heavy, it should be given a larger angle; but care should be taken not to give it too great an angle, because the longitudinal stability entirely depends upon the tail-plane being set at a much smaller angle of incidence than is the main surface, and if that difference is decreased too much, the aeroplane will become uncontrollable longitudinally. Sometimes the tail-plane is mounted on the aeroplane at the same angle as the main surface, but it actually engages the air at a lesser angle, owing to the air being deflected downwards by the main surface. There is then, in effect, a longitudinal dihedral as explained and illustrated in Chapter I. CLIMBS BADLY.--Such a condition is, apart from engine or propeller trouble, probably due to (1) distorted surfaces, or (2) too small an angle of incidence. FLIGHT SPEED POOR.--Such a condition is, apart from engine or propeller trouble, probably due to (1) distorted surfaces, (2) too great an angle of incidence, or (3) dirt or mud, and consequently excessive skin-friction. INEFFICIENT CONTROL is probably due to (1) wrong setting of control surfaces, (2) distortion of control surfaces, or (3) control cables being badly tensioned. WILL NOT "TAXI" STRAIGHT.--If the aeroplane is uncontrollable on the ground, it is probably due to (1) alignment of undercarriage being wrong, or (2) unequal tension of shock absorbers. CHAPTER IV THE PROPELLER, OR "AIR-SCREW" The sole object of the propeller is to translate the power of the engine into thrust. The propeller screws through the air, and its blades, being set at an angle inclined to the direction of motion, secure a reaction, as in the case of the aeroplane's lifting surface. This reaction may be conveniently divided into two component parts or values, namely, Thrust and Drift (see illustration overleaf). The Thrust is opposed to the Drift of the aeroplane, and must be equal and opposite to it at flying speed. If it falls off in power, then the flying speed must decrease to a velocity, at which the aeroplane drift equals the decreased thrust. The Drift of the propeller may be conveniently divided into the following component values: _Active Drift_, produced by the useful thrusting part of the propeller. _Passive Drift_, produced by all the rest of the propeller, _i.e._, by its detrimental surface. _Skin-Friction_, produced by the friction of the air with roughness of surface. _Eddies_ attending the movement of the air caused by the action of the propeller. _Cavitation_ (very marked at excessive speed of revolution). A tendency of the propeller to produce a cavity or semi-vacuum in which it revolves, the thrust decreasing with increase of speed and cavitation. THRUST-DRIFT RATIO.--The proportion of thrust to drift is of paramount importance, for it expresses the efficiency of the propeller. It is affected by the following factors: _Speed of Revolution._--The greater the speed, the greater the proportion of drift to thrust. This is due to the increase with speed of the passive drift, which carries with it no increase in thrust. For this reason propellers are often geared down to revolve at a lower speed than that of the engine. _Angle of Incidence._--The same reasons as in the case of the aeroplane surface. _Aspect Ratio._--Ditto. _Camber._--Ditto. [Illustration: M, Direction of motion of propeller (rotary). R, Direction of reaction. T, Direction of thrust. AD, Direction of the resistance of the air to the passage of the aeroplane, _i.e._, aeroplane drift. D, Direction of propeller drift (rotary). P, Engine power, opposed to propeller drift and transmitted to the propeller through the propeller shaft.] In addition to the above factors there are, when it comes to actually designing a propeller, mechanical difficulties to consider. For instance, the blades must be of a certain strength and consequent thickness. That, in itself, limits the aspect ratio, for it will necessitate a chord long enough in proportion to the thickness to make a good camber possible. Again, the diameter of the propeller must be limited, having regard to the fact that greater diameters than those used to-day would not only result in excessive weight of construction, but would also necessitate a very high undercarriage to keep the propeller off the ground, and such undercarriage would not only produce excessive drift, but would also tend to make the aeroplane stand on its nose when alighting. The latter difficulty cannot be overcome by mounting the propeller higher, as the centre of its thrust must be approximately coincident with the centre of aeroplane drift. MAINTENANCE OF EFFICIENCY. The following conditions must be observed: 1. PITCH ANGLE.--The angle, at any given point on the propeller, at which the blade is set is known as the pitch angle, and it must be correct to half a degree if reasonable efficiency is to be maintained. This angle secures the "pitch," which is the distance the propeller advances during one revolution, supposing the air to be solid. The air, as a matter of fact, gives back to the thrust of the blades just as the pebbles slip back as one ascends a shingle beach. Such "give-back" is known as _Slip_. If a propeller has a pitch of, say, 10 feet, but actually advances, say, only 8 feet owing to slip, then it will be said to possess 20 per cent. slip. Thus, the pitch must equal the flying speed of the aeroplane plus the slip of the propeller. For example, let us find the pitch of a propeller, given the following conditions: Flying speed ... 70 miles per hour. Propeller revolutions ... 1,200 per minute. Slip ... 15 per cent. First find the distance in feet the aeroplane will travel forward in one minute. That is-- 369,600 feet (70 miles) ----------------------- = 6,160 feet per minute. 60 " (minutes) Now divide the feet per minute by the propeller revolutions per minute, add 15 per cent. for the slip, and the result will be the propeller pitch: 6,160 ----- + 15 per cent. = 5.903 feet. 1,200 In order to secure a constant pitch from root to tip of blade, the pitch angle decreases towards the tip. This is necessary, since the end of the blade travels faster than its root, and yet must advance forward at the same speed as the rest of the propeller. For example, two men ascending a hill. One prefers to walk fast and the other slowly, but they wish to arrive at the top of the hill simultaneously. Then the fast walker must travel a farther distance than the slow one, and his angle of path (pitch angle) must then be smaller than the angle of path taken by the slow walker. Their pitch angles are different, but their pitch (in this case altitude reached in a given time) is the same. [Illustration] In order to test the pitch angle, the propeller must be mounted upon a shaft at right angles to a beam the face of which must be perfectly level, thus: [Illustration] First select a point on the blade at some distance (say about 2 feet) from the centre of the propeller. At that point find, by means of a protractor, the angle a projection of the chord makes with the face of the beam. That angle is the pitch angle of the blade at that point. Now lay out the angle on paper, thus: [Illustration] The line above and parallel to the circumference line must be placed in a position making the distance between the two lines equal to the specified pitch, which is, or should be, marked upon the boss of the propeller. Now find the circumference of the propeller where the pitch angle is being tested. For example, if that place is 2 feet radius from the centre, then the circumference will be 2 feet x 2 = 4 feet diameter, which, if multiplied by 3.1416 = 15.56 feet circumference. Now mark off the circumference distance, which is represented above by A--B, and reduce it in scale for convenience. The distance a vertical line makes between B and the chord line is the pitch at the point where the angle is being tested, and it should coincide with the specified pitch. You will note, from the above illustration, that the actual pitch line should meet the junction of the chord line and top line. The propeller should be tested at several points, about a foot apart, on each blade; and the diagram, provided the propeller is not faulty, will then look like this: [Illustration: A, B, C, and D, Actual pitch at points tested. I, Pitch angle at point tested nearest to centre of propeller. E, Circumference at I. J, Pitch angle at point tested nearest to I. F, Circumference at J. K, Pitch angle at next point tested. G, Circumference at K. L, Pitch angle tested at point nearest tip of blade. H, Circumference at L.] At each point tested the actual pitch coincides with the specified pitch: a satisfactory condition. A faulty propeller will produce a diagram something like this: [Illustration] At every point tested the pitch angle is wrong, for nowhere does the actual pitch coincide with the specified pitch. Angles A, C, and D, are too large, and B is too small. The angle should be correct to half a degree if reasonable efficiency is to be maintained. A fault in the pitch angle may be due to (1) faulty manufacture, (2) distortion, or (3) the shaft hole through the boss being out of position. 2. STRAIGHTNESS.--To test for straightness the propeller must be mounted upon a shaft. Now bring the tip of one blade round to graze some fixed object. Mark the point it grazes. Now bring the other tip round, and it should come within 1/8 inch of the mark. If it does not do so, it is due to (1) faulty manufacture, (2) distortion, or (3) to the hole through the boss being out of position. 3. LENGTH.--The blades should be of equal length to 1/16 inch. 4. BALANCE.--The usual method of testing a propeller for balance is as follows: Mount it upon a shaft, which must be on ball-bearings. Place the propeller in a horizontal position, and it should remain in that position. If a weight of a trifle over an ounce placed in a bolt-hole on one side of the boss fails to disturb the balance, then the propeller is usually regarded as unfit for use. [Illustration] The above method is rather futile, as it does not test for the balance of centrifugal force, which comes into play as soon as the propeller revolves. It can be tested as follows: [Illustration] The propeller must be in a horizontal position, and then weighed at fixed points, such as A, B, C, D, E, and F, and the weights noted. The points A, B, and C must, of course, be at the same fixed distances from the centre of the propeller as the points D, E, and F. Now reverse the propeller and weigh at each point again. Note the results. The first series of weights should correspond to the second series, thus: Weight A should equal weight F. Weight B should equal weight E. Weight C should equal weight D. There is no standard practice as to the degree of error permissible, but if there are any appreciable differences the propeller is unfit for use. 5. SURFACE AREA.--The surface area of the blades should be equal. Test with calipers thus: [Illustration] The distance A--B should equal K--L. The distance C--D should equal I--J. The distance E--F should equal G--H. The points between which the distances are taken must, of course, be at the same distance from the centre in the case of each blade. There is no standard practice as to the degree of error permissible. If, however, there is an error of over 1/8 inch, the propeller is really unfit for use. 6. CAMBER.--The camber (curvature) of the blades should be (1) equal, (2) decrease evenly towards the tips of the blades, and (3) the greatest depth of the curve should, at any point of the blade, be approximately at the same percentage of the chord from the leading edge as at other points. It is difficult to test the top camber without a set of templates,[18] but a fairly accurate idea of the concave camber can be secured by slowly passing a straight-edge along the blade, thus: [Illustration] The camber can now be easily seen, and as the straight-edge is passed along the blade, the observer should look for any irregularities of the curvature, which should gradually and evenly decrease towards the tip of the blade. 7. THE JOINTS.--The usual method for testing the glued joints is by revolving the propeller at greater speed than it will be called upon to make during flight, and then carefully examining the joints to see if they have opened. It is not likely, however, that the reader will have the opportunity of making this test. He should, however, examine all the joints very carefully, trying by hand to see if they are quite sound. Suspect a propeller of which the joints appear to hold any thickness of glue. Sometimes the joints in the boss open a little, but this is not dangerous unless they extend to the blades, as the bolts will hold the laminations together. 8. CONDITION OF SURFACE.--The surface should be very smooth, especially towards the tips of the blades. Some propeller tips have a speed of over 30,000 feet a minute, and any roughness will produce a bad drift or resistance and lower the efficiency. 9. MOUNTING.--Great care should be taken to see that the propeller is mounted quite straight on its shaft. Test in the same way as for straightness. If it is not straight, it is possibly due to some of the propeller bolts being too slack or to others having been pulled up too tightly. FLUTTER.--Propeller "flutter," or vibration, may be due to faulty pitch angle, balance, camber, surface area, or to bad mounting. It causes a condition sometimes mistaken for engine trouble, and one which may easily lead to the collapse of the propeller. CARE OF PROPELLERS.--The care of propellers is of the greatest importance, as they become distorted very easily. 1. Do not store them in a very damp or a very dry place. 2. Do not store them where the sun will shine upon them. 3. Never leave them long in a horizontal position or leaning up against a wall. 4. They should be hung on horizontal pegs, and the position of the propellers should be vertical. If the points I have impressed upon you in these notes are not attended to, you may be sure of the following results: 1. Lack of efficiency, resulting in less aeroplane speed and climb than would otherwise be the case. 2. Propeller "flutter" and possible collapse. 3. A bad stress upon the propeller shaft and its bearings. TRACTOR.--A propeller mounted in front of the main surface. PUSHER.--A propeller mounted behind the main surface. FOUR-BLADED PROPELLERS.--Four-bladed propellers are suitable only when the pitch is comparatively large. For a given pitch, and having regard to "interference," they are not so efficient as two-bladed propellers. [Illustration: SPIRAL COURSES OF TWO-BLADE TIPS. SPIRAL COURSES OF FOUR-BLADE TIPS. Pitch the same in each case.] The smaller the pitch, the less the "gap," _i.e._, the distance, measured in the direction of the thrust, between the spiral courses of the blades (see illustration on preceding page). If the gap is too small, then the following blade will engage air which the preceding blade has put into motion, with the result that the following blade will not secure as good a reaction as would otherwise be the case. It is very much the same as in the case of the aeroplane gap. For a given pitch, the gap of a four-bladed propeller is only half that of a two-bladed one. Therefore the four-bladed propeller is only suitable for large pitch, as such pitch produces spirals with a large gap, thus offsetting the decrease in gap caused by the numerous blades. The greater the speed of rotation, the less the pitch for a given aeroplane speed. Then, in order to secure a large pitch and consequently a good gap, the four-bladed propeller is usually geared to rotate at a lower speed than would be the case if directly attached to the engine crank-shaft. [Footnote 18: I have heard of temporary ones being made quickly by bending strips of lead over the convex side of the blade, but I should think it very difficult to secure a sufficient degree of accuracy in that way.] CHAPTER V MAINTENANCE CLEANLINESS.--The fabric must be kept clean and free from oil, as that will rot it. To take out dirt or oily patches, try acetone. If that will not remedy matters, then try petrol, but use it sparingly, as otherwise it will take off an unnecessary amount of dope. If that will not remove the dirt, then hot water and soap will do so, but, in that case, be sure to use soap having no alkali in it, as otherwise it may injure the fabric. Use the water sparingly, or it may get inside the planes and rust the internal bracing wires, or cause some of the wooden framework to swell. The wheels of the undercarriage have a way of throwing up mud on to the lower surface. This should, if possible, be taken off while wet. It should never be scraped off when dry, as that may injure the fabric. If dry, then it should be moistened before being removed. Measures should be taken to prevent dirt from collecting upon any part of the aeroplane, as, otherwise, excessive skin-friction will be produced with resultant loss of flight speed. The wires, being greasy, collect dirt very easily. CONTROL CABLES.--After every flight the rigger should pass his hand over the control cables and carefully examine them near pulleys. Removal of grease may be necessary to make a close inspection possible. If only one strand is broken the wire should be replaced. Do not forget the aileron balance wire on the top surface. Once a day try the tension of the control cables by smartly moving the control levers about as explained elsewhere. WIRES.--All the wires should be kept well greased or oiled, and in the correct tension. When examining the wires, it is necessary to place the aeroplane on level ground, as otherwise it may be twisted, thus throwing some wires into undue tension and slackening others. The best way, if there is time, is to pack the machine up into its "flying position." If you see a slack wire, do not jump to the conclusion that it must be tensioned. Perhaps its opposition wire is too tight, in which case slacken it, and possibly you will find that will tighten the slack wire. Carefully examine all wires and their connections near the propeller, and be sure that they are snaked round with safety wire, so that the latter may keep them out of the way of the propeller if they come adrift. The wires inside the fuselage should be cleaned and regreased about once a fortnight. STRUTS AND SOCKETS.--These should be carefully examined to see if any splitting has occurred. DISTORTION.--Carefully examine all surfaces, including the controlling surfaces, to see whether any distortion has occurred. If distortion can be corrected by the adjustment of wires, well and good; but if not, then some of the internal framework probably requires replacement. ADJUSTMENTS.--Verify the angles of incidence, dihedral, and stagger, and the rigging position of the controlling surfaces, as often as possible. UNDERCARRIAGE.--Constantly examine the alignment and fittings of the undercarriage, and the condition of tyres and shock absorbers. The latter, when made of rubber, wear quickest underneath. Inspect axles and skids to see if there are any signs of them becoming bent. The wheels should be taken off occasionally and greased. LOCKING ARRANGEMENTS.--Constantly inspect the locking arrangements of turnbuckles, bolts, etc. Pay particular attention to the control cable connections, and to all moving parts in respect of the controls. LUBRICATION.--Keep all moving parts, such as pulleys, control levers, and hinges of controlling surfaces, well greased. SPECIAL INSPECTION.--Apart from constantly examining the aeroplane with reference to the above points I have made, I think that, in the case of an aeroplane in constant use, it is an excellent thing to make a special inspection of every part, say, once a week. This will take from two to three hours according to the type of aeroplane. In order to carry it out methodically, the rigger should have a list of every part down to the smallest split-pin. He can then check the parts as he examines them, and nothing will be passed over. This, I know from experience, greatly increases the confidence of the pilot, and tends to produce good work in the air. WINDY WEATHER.--The aeroplane, when on the ground, should face the wind; and it is advisable to lash the control lever fast, so that the controlling surfaces may not be blown about and possibly damaged. "VETTING" BY EYE.--This should be practised at every opportunity, and, if persevered in, it is possible to become quite expert in diagnosing by eye faults in flight efficiency, stability, and control. The aeroplane should be standing upon level ground, or, better than that, packed up into its "flying position." Now stand in front of it and line up the leading edge with the main spar, rear spar, and trailing edge. Their shadows can usually be seen through the fabric. Allowance must, of course, be made for wash-in and wash-out; otherwise, the parts I have specified should be parallel with each other. Now line up the centre part of the main-plane with the tail-plane. The latter should be symmetrical with it. Next, sight each interplane front strut with its rear strut. They should be parallel. Then, standing on one side of the aeroplane, sight all the front struts. The one nearest to you should cover all the others. This applies to the rear struts also. Look for distortion of leading edges, main and rear spars, trailing edges, tail-plane, and controlling surfaces. This sort of thing, if practised constantly, will not only develop an expert eye for diagnosis of faults, but will also greatly assist in impressing upon the memory the characteristics and possible troubles of the various types of aeroplanes. MISHANDLING ON THE GROUND.--This is the cause of a lot of unnecessary damage. The golden rule to observe is, PRODUCE NO BENDING STRESSES. Nearly all the wood in an aeroplane is designed to take merely the stress of direct compression, and it cannot be bent safely. Therefore, in packing an aeroplane up from the ground, or in pulling or pushing it about, be careful to stress it in such a way as to produce, as far as possible, only direct compression stresses. For instance, if it is necessary to support the lifting surface, then the packing should be arranged to come directly under the struts so that they may take the stress in the form of compression for which they are designed. Such supports should be covered with soft packing in order to prevent the fabric from becoming damaged. When pulling an aeroplane along, if possible, pull from the top of the undercarriage struts. If necessary to pull from elsewhere, then do so by grasping the interplane struts as low down as possible. Never pull by means of wires. Never lay fabric-covered parts upon a concrete floor. Any slight movement will cause the fabric to scrape over the floor with resultant damage. Struts, spars, etc., should never be left about the floor, as in such position they are likely to become scored. I have already explained the importance of protecting the outside fibres of the wood. Remember also that wood becomes distorted easily. This particularly applies to interplane struts. If there are no proper racks to stand them in, then the best plan is to lean them up against the wall in as near a vertical position as possible. TIME.--Learn to know the time necessary to complete any of the various rigging jobs. This is really important. Ignorance of this will lead to bitter disappointments in civil life; and, where Service flying is concerned, it will, to say the least of it, earn unpopularity with senior officers, and fail to develop respect and good work where men are concerned. THE AEROPLANE SHED.--This should be kept as clean and orderly as possible. A clean, smart shed produces briskness, energy, and pride of work. A dirty, disorderly shed nearly always produces slackness and poor quality of work, lost tools, and mislaid material. [Illustration] [Illustration] GLOSSARY _The numbers at the right-hand side of the page indicate the parts numbered in the preceding diagrams._ =Aeronautics=--The science of aerial navigation. =Aerofoil=--A rigid structure, of large superficial area relative to its thickness, designed to obtain, when driven through the air at an angle inclined to the direction of motion, a reaction from the air approximately at right angles to its surface. Always cambered when intended to secure a reaction in one direction only. As the term "aerofoil" is hardly ever used in practical aeronautics, I have, throughout this book, used the term SURFACE, which, while academically incorrect, since it does not indicate thickness, is the term usually used to describe the cambered lifting surfaces, _i.e._, the "planes" or "wings," and the stabilizers and the controlling aerofoils. =Aerodrome=--The name usually applied to a ground used for the practice of aviation. It really means "flying machine," but is never used in that sense nowadays. =Aeroplane=--A power-driven aerofoil fitted with stabilizing and controlling surfaces. =Acceleration=--The rate of change of velocity. =Angle of Incidence=--The angle at which the "neutral lift line" of a surface attacks the air. =Angle of Incidence, Rigger's=--The angle the chord of a surface makes with a line parallel to the axis of the propeller. =Angle of Incidence, Maximum=--The greatest angle of incidence at which, for a given power, surface (including detrimental surface), and weight, horizontal flight can be maintained. =Angle of Incidence, Minimum=--The smallest angle of incidence at which, for a given power, surface (including detrimental surface), and weight, horizontal flight can be maintained. =Angle of Incidence, Best Climbing=--That angle of incidence at which an aeroplane ascends quickest. An angle approximately halfway between the maximum and optimum angles. =Angle of Incidence, Optimum=--The angle of incidence at which the lift-drift ratio is the highest. =Angle, Gliding=--The angle between the horizontal and the path along which an aeroplane, at normal flying speed, but not under engine power, descends in still air. =Angle, Dihedral=--The angle between two planes. =Angle, Lateral Dihedral=--The lifting surface of an aeroplane is said to be at a lateral dihedral angle when it is inclined upward towards its wing-tips. =Angle, Longitudinal Dihedral=--The main surface and tail surface are said to be at a longitudinal dihedral angle when the projections of their neutral lift lines meet and produce an angle above them. =Angle, Rigger's Longitudinal Dihedral=--Ditto, but substituting "chords" for "neutral lift lines." =Angle, Pitch=--The angle at any given point of a propeller, at which the blade is inclined to the direction of motion when the propeller is revolving but the aeroplane stationary. =Altimeter=--An instrument used for measuring height. =Air-Speed Indicator=--An instrument used for measuring air pressures or velocities. It consequently indicates whether the surface is securing the requisite reaction for flight. Usually calibrated in miles per hour, in which case it indicates the correct number of miles per hour at only one altitude. This is owing to the density of the air decreasing with increase of altitude and necessitating a greater speed through space to secure the same air pressure as would be secured by less speed at a lower altitude. It would be more correct to calibrate it in units of air pressure. [1] =Air Pocket=--A local movement or condition of the air causing an aeroplane to drop or lose its correct attitude. =Aspect-Ratio=--The proportion of span to chord of a surface. =Air-Screw (Propeller)=--A surface so shaped that its rotation about an axis produces a force (thrust) in the direction of its axis. [2] =Aileron=--A controlling surface, usually situated at the wing-tip, the operation of which turns an aeroplane about its longitudinal axis; causes an aeroplane to tilt sideways. [3] =Aviation=--The art of driving an aeroplane. =Aviator=--The driver of an aeroplane. =Barograph=--A recording barometer, the charts of which can be calibrated for showing air density or height. =Barometer=--An instrument used for indicating the density of air. =Bank, to=--To turn an aeroplane about its longitudinal axis (to tilt sideways) when turning to left or right. =Biplane=--An aeroplane of which the main lifting surface consists of a surface or pair of wings mounted above another surface or pair of wings. =Bay=--The space enclosed by two struts and whatever they are fixed to. =Boom=--A term usually applied to the long spars joining the tail of a "pusher" aeroplane to its main lifting surface. [4] =Bracing=--A system of struts and tie wires to transfer a force from one point to another. =Canard=--Literally "duck." The name which was given to a type of aeroplane of which the longitudinal stabilizing surface (_empennage_) was mounted in front of the main lifting surface. Sometimes termed "tail-first" aeroplanes, but such term is erroneous, as in such a design the main lifting surface acts as, and is, the _empennage_. =Cabre=--To fly or glide at an excessive angle of incidence; tail down. =Camber=--Curvature. =Chord=--Usually taken to be a straight line between the trailing and leading edges of a surface. =Cell=--The whole of the lower surface, that part of the upper surface directly over it, together with the struts and wires holding them together. =Centre (Line) of Pressure=--A line running from wing-tip to wing-tip, and through which all the air forces acting upon the surface may be said to act, or about which they may be said to balance. =Centre (Line) of Pressure, Resultant=--A line transverse to the longitudinal axis, and the position of which is the resultant of the centres of pressure of two or more surfaces. =Centre of Gravity=--The centre of weight. =Cabane=--A combination of two pylons, situated over the fuselage, and from which the anti-lift wires are suspended. [5] =Cloche=--Literally "bell." Is applied to the bell-shaped construction which forms the lower part of the pilot's control lever in a Bleriot monoplane, and to which the control cables are attached. =Centrifugal Force=--Every body which moves in a curved path is urged outwards from the centre of the curve by a force termed "centrifugal." =Control Lever=--A lever by means of which the controlling surfaces are operated. It usually operates the ailerons and elevator. The "joy-stick." [6] =Cavitation, Propeller=--The tendency to produce a cavity in the air. =Distance Piece=--A long, thin piece of wood (sometimes tape) passing through and attached to all the ribs in order to prevent them from rolling over sideways. [7] =Displacement=--Change of position. =Drift= (_of an aeroplane as distinct from the propeller_)--The horizontal component of the reaction produced by the action of driving through the air a surface inclined upwards and towards its direction of motion _plus_ the horizontal component of the reaction produced by the "detrimental" surface _plus_ resistance due to "skin-friction." Sometimes termed "head-resistance." =Drift, Active=--Drift produced by the lifting surface. =Drift, Passive=--Drift produced by the detrimental surface. =Drift= (_of a propeller_)--Analogous to the drift of an aeroplane. It is convenient to include "eddies" and "cavitation" within this term. =Drift, to=--To be carried by a current of air; to make leeway. =Dive, to=--To descend so steeply as to produce a speed greater than the normal flying speed. =Dope, to=--To paint a fabric with a special fluid for the purpose of tightening and protecting it. =Density=--Mass of unit volume; for instance, pounds per cubic foot. =Efficiency=-- Output ------ Input. =Efficiency= (_of an aeroplane as distinct from engine and propeller_)-- Lift and Velocity --------------------------- Thrust (= aeroplane drift). =Efficiency, Engine=-- Brake horse-power ---------------------- Indicated horse-power. =Efficiency, Propeller=-- Thrust horse-power -------------------------------- Horse-power received from engine (= propeller drift). NOTE.--The above terms can, of course, be expressed in foot-pounds. It is then only necessary to divide the upper term by the lower one to find the measure of efficiency. =Elevator=--A controlling surface, usually hinged to the rear of the tail-plane, the operation of which turns an aeroplane about an axis which is transverse to the direction of normal horizontal flight. [8] =Empennage=--See "Tail-plane." =Energy=--Stored work. For instance, a given weight of coal or petroleum stores a given quantity of energy which may be expressed in foot-pounds. =Extension=--That part of the upper surface extending beyond the span of the lower surface. [9] =Edge, Leading=--The front edge of a surface relative to its normal direction of motion. [10] =Edge, Trailing=--The rear edge of a surface relative to its normal direction of motion. [11] =Factor of Safety=--Usually taken to mean the result found by dividing the stress at which a body will collapse by the maximum stress it will be called upon to bear. =Fineness= (_of stream-line_)--The proportion of length to maximum width. =Flying Position=--A special position in which an aeroplane must be placed when rigging it or making adjustments. It varies with different types of aeroplanes. Would be more correctly described as "rigging position." =Fuselage=--That part of an aeroplane containing the pilot, and to which is fixed the tail-plane. [12] =Fin=--Additional keel-surface, usually mounted at the rear of an aeroplane. [13] =Flange= (_of a rib_)--That horizontal part of a rib which prevents it from bending sideways. [14] =Flight=--The sustenance of a body heavier than air by means of its action upon the air. =Foot-pound=--A measure of work representing the weight of 1 lb. raised 1 foot. =Fairing=--Usually made of thin sheet aluminium, wood, or a light construction of wood and fabric; and bent round detrimental surface in order to give it a "fair" or "stream-like" shape. [15] =Gravity=--Is the force of the Earth's attraction upon a body. It decreases with increase of distance from the Earth. See "Weight." =Gravity, Specific=-- Density of substance -------------------- Density of water. Thus, if the density of water is 10 lb. per unit volume, the same unit volume of petrol, if weighing 7 lb., would be said to have a specific gravity of 7/10, _i.e._, 0.7. =Gap= (_of an aeroplane_)--The distance between the upper and lower surfaces of a biplane. In a triplane or multiplane, the distance between any two of its surfaces. [16] =Gap, Propeller=--The distance, measured in the direction of the thrust, between the spiral courses of the blades. =Girder=--A structure designed to resist bending, and to combine lightness and strength. =Gyroscope=--A heavy circular wheel revolving at high speed, the effect of which is a tendency to maintain its plane of rotation against disturbing forces. =Hangar=--An aeroplane shed. =Head-resistance=--Drift. The resistance of the air to the passage of a body. =Helicopter=--An air-screw revolving about a vertical axis, the direction of its thrust being opposed to gravity. =Horizontal Equivalent=--The plan view of a body whatever its attitude may be. =Impulse=--A force causing a body to gain or lose momentum. =Inclinometer=--A curved form of spirit-level used for indicating the attitude of a body relative to the horizontal. =Instability=--An inherent tendency of a body, which, if the body is disturbed, causes it to move into a position as far as possible away from its first position. =Instability, Neutral=--An inherent tendency of a body to remain in the position given it by the force of a disturbance, with no tendency to move farther or to return to its first position. =Inertia=--The inherent resistance to displacement of a body as distinct from resistance the result of an external force. =Joy-Stick=--See "Control Lever." =Keel-Surface=--Everything to be seen when viewing an aeroplane from the side of it. =King-Post=--A bracing strut; in an aeroplane, usually passing through a surface and attached to the main spar, and from the end or ends of which wires are taken to spar, surface, or other part of the construction in order to prevent distortion. When used in connection with a controlling surface, it usually performs the additional function of a lever, control cables connecting its ends with the pilot's control lever. [17] =Lift=--The vertical component of the reaction produced by the action of driving through the air a surface inclined upwards and towards its direction of motion. =Lift, Margin of=--The height an aeroplane can gain in a given time and starting from a given altitude. =Lift-Drift Ratio=--The proportion of lift to drift. =Loading=--The weight carried by an aerofoil. Usually expressed in pounds per square foot of superficial area. =Longeron=--The term usually applied to any long spar running length-ways of a fuselage. [18] =Mass=--The mass of a body is a measure of the quantity of material in it. =Momentum=--The product of the mass and velocity of a body is known as "momentum." =Monoplane=--An aeroplane of which the main lifting surface consists of one surface or one pair of wings. =Multiplane=--An aeroplane of which the main lifting surface consists of numerous surfaces or pairs of wings mounted one above the other. =Montant=--Fuselage strut. =Nacelle=--That part of an aeroplane containing the engine and/or pilot and passenger, and to which the tail-plane is not fixed. [19] =Neutral Lift Line=--A line taken through a surface in a forward direction relative to its direction of motion, and starting from its trailing edge. If the attitude of the surface is such as to make the said line coincident with the direction of motion, it results in no lift, the reaction then consisting solely of drift. The position of the neutral lift line, _i.e._, the angle it makes with the chord, varies with differences of camber, and it is found by means of wind-tunnel research. =Newton's Laws of Motion=--1. If a body be at rest, it will remain at rest; or, if in motion, it will move uniformly in a straight line until acted upon by some force. 2. The rate of change of the quantity of motion (momentum) is proportional to the force which causes it, and takes place in the direction of the straight line in which the force acts. If a body be acted upon by several forces, it will obey each as though the others did not exist, and this whether the body be at rest or in motion. 3. To every action there is opposed an equal and opposite reaction. =Ornithopter (or Orthopter)=--A flapping wing design of aircraft intended to imitate the flight of a bird. =Outrigger=--This term is usually applied to the framework connecting the main surface with an elevator placed in advance of it. Sometimes applied to the "tail-boom" framework connecting the tail-plane with the main lifting surface. [20] =Pancake, to=--To "stall." =Plane=--This term is often applied to a lifting surface. Such application is not quite correct, since "plane" indicates a flat surface, and the lifting surfaces are always cambered. =Propeller=--See "Air-Screw." =Propeller, Tractor=--An air-screw mounted in front of the main lifting surface. =Propeller, Pusher=--An air-screw mounted behind the main lifting surface. =Pusher=--An aeroplane of which the propeller is mounted behind the main lifting surface. =Pylon=--Any V-shaped construction from the point of which wires are taken. =Power=--Rate of working. [21] =Power, Horse=--One horse-power represents a force sufficient to raise 33,000 lb. 1 foot in a minute. =Power, Indicated Horse=--The I.H.P. of an engine is a measure of the rate at which work is done by the pressure upon the piston or pistons, as distinct from the rate at which the engine does work. The latter is usually termed "brake horse-power," since it may be measured by an absorption brake. =Power, Margin of=--The available quantity of power above that necessary to maintain horizontal flight at the optimum angle. =Pitot Tube=--A form of air-speed indicator consisting of a tube with open end facing the wind, which, combined with a static pressure or suction tube, is used in conjunction with a gauge for measuring air pressures or velocities. (_No. 1 in diagram._) =Pitch, Propeller=--The distance a propeller advances during one revolution supposing the air to be solid. =Pitch, to=--To plunge nose-down. =Reaction=--A force, equal and opposite to the force of the action producing it. =Rudder=--A controlling surface, usually hinged to the tail, the operation of which turns an aeroplane about an axis which is vertical in normal horizontal flight; causes an aeroplane to turn to left or right of the pilot. [22] =Roll, to=--To turn about the longitudinal axis. =Rib, Ordinary=--A light curved wooden part mounted in a fore and aft direction within a surface. The ordinary ribs give the surface its camber, carry the fabric, and transfer the lift from the fabric to the spars. [23] =Rib, Compression=--Acts as an ordinary rib, besides bearing the stress of compression produced by the tension of the internal bracing wires. [24] =Rib, False=--A subsidiary rib, usually used to improve the camber of the front part of the surface. [25] =Right and Left Hand=--Always used relative to the position of the pilot. When observing an aeroplane from the front of it, the right hand side of it is then on the left hand of the observer. =Remou=--A local movement or condition of the air which may cause displacement of an aeroplane. =Rudder-Bar=--A control lever moved by the pilot's feet, and operating the rudder. [26] =Surface=--See "Aerofoil." =Surface, Detrimental=--All exterior parts of an aeroplane including the propeller, but excluding the (aeroplane) lifting and (propeller) thrusting surfaces. =Surface, Controlling=--A surface the operation of which turns an aeroplane about one of its axes. =Skin-Friction=--The friction of the air with roughness of surface. A form of drift. =Span=--The distance from wing-tip to wing-tip. =Stagger=--The distance the upper surface is forward of the lower surface when the axis of the propeller is horizontal. =Stability=--The inherent tendency of a body, when disturbed, to return to its normal position. =Stability, Directional=--The stability about an axis which is vertical during normal horizontal flight, and without which an aeroplane has no natural tendency to remain upon its course. =Stability, Longitudinal=--The stability of an aeroplane about an axis transverse to the direction of normal horizontal flight, and without which it has no tendency to oppose pitching and tossing. =Stability, Lateral=--The stability of an aeroplane about its longitudinal axis, and without which it has no tendency to oppose sideways rolling. =Stabilizer=--A surface, such as fin or tail-plane, designed to give an aeroplane inherent stability. =Stall, to=--To give or allow an aeroplane an angle of incidence greater than the "maximum" angle, the result being a fall in the lift-drift ratio, the lift consequently becoming less than the weight of the aeroplane, which must then fall, _i.e._, "stall" or "pancake." =Stress=--Burden or load. =Strain=--Deformation produced by stress. =Side-Slip, to=--To fall as a result of an excessive "bank" or "roll." =Skid, to=--To be carried sideways by centrifugal force when turning to left or right. =Skid, Undercarriage=--A spar, mounted in a fore and aft direction, and to which the wheels of the undercarriage are sometimes attached. Should a wheel give way the skid is then supposed to act like the runner of a sleigh and to support the aeroplane. [28] =Skid, Tail=--A piece of wood or other material, orientable, and fitted with shock absorbers, situated under the tail of an aeroplane in order to support it upon the ground and to absorb the shock of alighting. [28_a_] =Section=--Any separate part of the top surface, that part of the bottom surface immediately underneath it, with their struts and wires. =Spar=--Any long piece of wood or other material. =Spar, Main=--A spar within a surface and to which all the ribs are attached, such spar being the one situated nearest to the centre of pressure. It transfers more than half the lift from the ribs to the bracing. [29] =Spar, Rear=--A spar within a surface, and to which all the ribs are attached, such spar being situated at the rear of the centre of pressure and at a greater distance from it than is the main spar. It transfers less than half of the lift from the ribs to the bracing. [30] =Strut=--Any wooden member intended to take merely the stress of direct compression. =Strut, Interplane=--A strut holding the top and bottom surfaces apart. [31] =Strut, Fuselage=--A strut holding the _fuselage longerons_ apart. It should be stated whether top, bottom, or side. If side, then it should be stated whether right or left hand. _Montant_. [32] =Strut, Extension=--A strut supporting an "extension" when not in flight. It may also prevent the extension from collapsing upwards during flight. [33] =Strut, undercarriage=-- [33_a_] =Strut, Dope=--A strut within a surface, so placed as to prevent the tension of the doped fabric from distorting the framework. [34] =Serving=--To bind round with wire, cord, or similar material. Usually used in connection with wood joints and wire cable splices. =Slip, Propeller=--The pitch less the distance the propeller advances during one revolution. =Stream-Line=--A form or shape of detrimental surface designed to produce minimum drift. =Toss, to=--To plunge tail-down. =Torque, Propeller=--The tendency of a propeller to turn an aeroplane about its longitudinal axis in a direction opposite to that in which the propeller revolves. =Tail-Slide=--A fall whereby the tail of an aeroplane leads. =Tractor=--An aeroplane of which the propeller is mounted in front of the main lifting surface. =Triplane=--An aeroplane of which the main lifting surface consists of three surfaces or pairs of wings mounted one above the other. =Tail-Plane=--A horizontal stabilizing surface mounted at some distance behind the main lifting surface. _Empennage_. [36] =Turnbuckle=--A form of wire-tightener, consisting of a barrel into each end of which is screwed an eyebolt. Wires are attached to the eyebolts and the required degree of tension is secured by means of rotating the barrel. =Thrust, Propeller=--See "Air-Screw." =Undercarriage=--That part of an aeroplane beneath the _fuselage_ or _nacelle_, and intended to support the aeroplane when at rest, and to absorb the shock of alighting. =Velocity=--Rate of displacement; speed. =Volplane=--A gliding descent. =Weight=--Is a measure of the force of the Earth's attraction (gravity) upon a body. The standard unit of weight in this country is 1 lb., and is the force of the Earth's attraction on a piece of platinum called _the standard pound_, deposited with the Board of Trade in London. At the centre of the Earth a body will be attracted with equal force in every direction. It will therefore have no weight, though its mass is unchanged. Gravity, of which weight is a measure, decreases with increase of altitude. =Web= (_of a rib_)--That vertical part of a rib which prevents it from bending upwards. [37_a_] =Warp, to=--To distort a surface in order to vary its angle of incidence. To vary the angle of incidence of a controlling surface. =Wash=--The disturbance of air produced by the flight of an aeroplane. =Wash-in=--An increasing angle of incidence of a surface towards its wing-tip. [38] =Wash-out=--A decreasing angle of incidence of a surface towards its wing-tip. [39] =Wing-tip=--The right or left-hand extremity of a surface. [40] =Wire=--A wire is, in Aeronautics, always known by the name of its function. =Wire, Lift or Flying=--A wire opposed to the direction of lift, and used to prevent a surface from collapsing upward during flight. [41] =Wire, Anti-lift or Landing=--A wire opposed to the direction of gravity, and used to sustain a surface when it is at rest. [42] =Wire, Drift=--A wire opposed to the direction of drift, and used to prevent a surface from collapsing backwards during flight. =Wire, Anti-drift=--A wire opposed to the tension of a drift wire, and used to prevent such tension from distorting the framework. [44] =Wire, Incidence=--A wire running from the top of an interplane strut to the bottom of the interplane strut in front of or behind it. It maintains the "stagger" and assists in maintaining the angle of incidence. Sometimes termed "stagger wire." [45] =Wire, Bracing=--Any wire holding together the framework of any part of an aeroplane. It is not, however, usually applied to the wires described above unless the function performed includes a function additional to those described above. Thus, a lift wire, while strictly speaking a bracing wire, is not usually described as one unless it performs the additional function of bracing some well-defined part such as the undercarriage. It will then be said to be an "undercarriage bracing lift wire." It might, perhaps, be acting as a drift wire also, in which case it will then be described as an "undercarriage bracing lift-drift wire." It should always be stated whether a bracing wire is (1) top, (2) bottom, (3) cross, or (4) side. If a "side bracing wire," then it should be stated whether right- or left-hand. =Wire, Internal Bracing=--A bracing wire (usually drift or anti-drift) within a surface. =Wire, Top Bracing=--A bracing wire, approximately horizontal and situated between the top longerons of fuselage, between top tail booms, or at the top of similar construction. [46] =Wire, Bottom Bracing=--Ditto, substituting "bottom" for "top." [47] =Wire, Side Bracing=--A bracing wire crossing diagonally a side bay of fuselage, tail boom bay, undercarriage side bay or centre-section side bay. This term is not usually used with reference to incidence wires, although they cross diagonally the side bays of the cell. It should be stated whether right- or left-hand. [48] =Wire, Cross Bracing=--A bracing wire, the position of which is diagonal from right to left when viewing it from the front of an aeroplane. [49] =Wire, Control Bracing=--A wire preventing distortion of a controlling surface. [50] =Wire, Control=--A wire connecting a controlling surface with the pilot's control lever, wheel, or rudder-bar. [51] =Wire, Aileron Gap=--A wire connecting top and bottom ailerons. [52] =Wire, Aileron Balance=--A wire connecting the right- and left-hand top ailerons. Sometimes termed the "aileron compensating wire." [53] =Wire, Snaking=--A wire, usually of soft metal, wound spirally or tied round another wire, and attached at each end to the framework. Used to prevent the wire round which it is "snaked" from becoming, in the event of its displacement, entangled with the propeller. =Wire, Locking=--A wire used to prevent a turnbuckle barrel or other fitting from losing its adjustment. =Wing=--Strictly speaking, a wing is one of the surfaces of an ornithopter. The term is, however, often applied to the lifting surface of an aeroplane when such surface is divided into two parts, one being the left-hand "wing," and the other the right-hand "wing." =Wind-Tunnel=--A large tube used for experimenting with surfaces and models, and through which a current of air is made to flow by artificial means. =Work=--Force × displacement. =Wind-Screen=--A small transparent screen mounted in front of the pilot to protect his face from the air pressure. Types of Aeroplanes. [Illustration: Plate I.] The first machine to fly--of which there is anything like authentic record--was the Ader "Avion," after which the more notable advances were made as shown above. [Illustration: Plate II.] The Henri Farman was the first widely used aeroplane. Above are shown the chief steps in its development. [Illustration: Plate III.] THE AVRO.--The aeroplane designed and built by Mr. A. V. Roe was the first successful heavier-than-air flying machine built by a British subject. Mr. Roe's progress may be followed in the picture, from his early "canard" biplane, through various triplanes, with 35 J.A.P. and 35 h.p. Green engines, to his successful tractor biplane with the same 35 h.p. Green, thence through the "totally enclosed" biplane 1912, with 60 h.p. Green, to the biplane 1913-14, with 80 h.p. Gnome. [Illustration: Plate IV.] THE SOPWITH LAND-GOING BIPLANES.--The earliest was a pair of Wright planes with a fuselage added. Next was the famous tractor with 80 h.p. Gnome. Then the "tabloid" of 1913, which set a completely new fashion in aeroplane design. From this developed the Gordon-Bennett racer shown over date 1914. The gun-carrier was produced about the same time, and the later tractor biplane in a development of the famous 80 h.p. but with 100 h.p. monosoupape Gnome. [Illustration: Plate V.] THE MAURICE FARMAN.--First, 1909, the 50-60 h.p. Renault and coil-spring chassis. 1910, the same chassis with beginning of the characteristic bent-up skids. 1911 appeared the huge French Military Trials 3-seater; also the round-ended planes and tails and "Henry" type wheels. This developed, 1912, into the square-ended planes and upper tail, and long double-acting ailerons of the British Military Trials. The 1913 type had two rectangular tail-planes and better seating arrangements, known affectionately as the "mechanical cow"; the same year came the first "shorthorn," with two tail-planes and a low nacelle. This finally developed into the carefully streamlined "shorthorn" with the raised nacelle and a single tail-plane. [Illustration: Plate VI.] THE SHORT "PUSHERS."--In 1909 came the semi-Wright biplane, with 35 h.p. Green, on which Mr. Moore-Brabazon won the "Daily Mail's" £1000 prize for the first mile flight on a circuit on a British aeroplane. Then the first box-kite flown by Mr. Grace at Wolverhampton. Later the famous "extension" type on which the first Naval officers learned to fly. Then the "38" type with elevator on the nacelle, on which dozens of R.N.A.S. pilots were taught. [Illustration: Plate VII.] SHORT TRACTORS, 1911-1912.--They were all co-existent, but the first was the "tractor-pusher" (bottom of picture). Then came the "twin-tractor plus propeller" (at top). A development was the "triple-tractor" (on the right), with two 50 h.p. Gnomes, one immediately behind the other under the cowl, one driving the two chains, the other coupled direct. Later came the single-engined 80 h.p. tractor (on the left), the original of the famous Short seaplanes. [Illustration: Plate VIII.] THE VICKERS MACHINES: First the Vickers-R.E.P. of 1911, which developed into the full-bodied No. V. with R.E.P. engine, then the Military Trials "sociable" with Viale engine, and so to the big No. VII with a 100 h.p. Gnome. Contemporary with the No. V and No. VI were a number of school box-kites of ordinary Farman type, which developed into the curious "pumpkin" sociable, and the early "gun 'bus" of 1913. Thence arrived the gun-carrier with 100 h.p. monosoupape Gnome. [Illustration: Plate IX.] THE BRISTOL AEROPLANES.--First, 1910, Farman type box-kites familiar to all early pupils. Then the miniature Maurice-Farman type biplane of the "Circuit of Britain." Contemporaneous was the "floating tail" monoplane designed by Pierre Prier, and after it a similar machine with fixed tail. Then came the handsome but unfortunate monoplane designed by M. Coanda for the Military Trials, 1912. [Illustration: Plate X.] THE BRISTOL TRACTORS.--Late 1912 came the round fuselaged tractor, with Gnome engine, designed by Mr. Gordon England for Turkey. 1912-13 came the biplane built onto the Military Trials monoplane type fuselage, also with a Gnome, designed by M. Coanda for Roumania. Then the Renault-engined Coanda tractor 1913, followed by 80 h.p. Gnome-engined scout, designed by Messrs. Barnwell and Busteed, which with Gnomes, le Rhones and Clergets, has been one of the great successes. Almost contemporary was the two-seater Bristol. [Illustration: Plate XI.] THE MARTINSYDES.--1909, first experimental monoplane built with small 4-cylinder engine. J.A.P.-engined machine, 1910, followed by the Gnome-engined machine, 1911. 1912, first big monoplane with Antoinette engine was built, followed by powerful Austro-Daimler monoplane, 1913. Then came the little Gnome-engined scout biplanes, 1914, some with, some without, skids. [Illustration: Plate XII.] THE CURTISS BIPLANES.--In 1909 came the "June-bug," the united product of Glen Curtiss, Dr. Graham Bell, and J. A. D. McCurdy. Then the box-kite type, 1909, on which Mr. Curtiss won the Gordon-Bennett Race at Reims. Next the "rear-elevator" pusher, 1912, followed by first tractor, 1913, with an outside flywheel. All purely Curtiss machines to that date had independent ailerons intended to get away from Wright patents. Following these came tractors with engines varying from 70 to 160 h.p., fitted with varying types of chassis. All these have ordinary ailerons. [Illustration: Plate XIII.] THE BLERIOT (1).--The first engine-driven machine was a "canard" monoplane. Then came the curious tractor monoplanes 1908-1909, in order shown. Famous "Type XI" was prototype of all Bleriot successes. "Type XII" was never a great success, though the ancestor of the popular "parasol" type. The big passenger carrier was a descendant of this type. [Illustration: Plate XIV.] THE BLERIOT (2):--1910, "Type XI," on which Mr. Grahame-White won Gordon-Bennett Race, with a 14-cylinder 100 h.p. Gnome. 1911 came the improved "Type XI," with large and effective elevator flaps. On this type, with a 50 h.p. Gnome, Lieut. de Conneau (M. Beaumont) won Paris-Rome Race and "Circuit of Britain." Same year saw experimental "Limousine" flown by M. Legagneux, and fast but dangerous "clipped-wing" Gordon-Bennett racer with the fish-tail, flown by Mr. Hamel. About the same time came the fish-tailed side-by-side two-seater, flown by Mr. Hamel at Hendon and by M. Perreyon in 1912 Military Trials. 1911, M. Bleriot produced the 100 h.p. three-seater which killed M. Desparmets in French Military Trials. 1912-13, M. Bleriot produced a quite promising experimental biplane, and a "monocoque" monoplane in which the passenger faced rearward. [Illustration: Plate XV.] THE BLERIOT (3)--1912 tandem two-seater proved one of the best machines of its day. 1913 "canard" lived up to its name. A "pusher" monoplane was built in which the propeller revolved on the top tail boom. This machine came to an untimely end, with the famous pilot, M. Perreyon. 1912 "tandem" was developed in 1914 into the type shown in centre; almost simultaneously "parasol" tandem appeared. 1914, M. Bleriot built a monoplane embodying a most valuable idea never fully developed. The engine tanks and pilot were all inside an armoured casing. Behind them the fuselage was a "monocoque" of three-ply wood bolted onto the armour. And behind this all the tail surfaces were bolted on as a separate unit. [Illustration: Plate XVI.] THE CAUDRON.--1910, came the machine with ailerons and a 28 h.p. Anzani. 1911 this was altered to warp control and a "star" Anzani was fitted. From this came the 35 h.p. type of 1912, one of the most successful of school machines. Small fast monoplane, 1912, was never further developed. 1913 appeared the familiar biplanes with 80 h.p. Gnomes, and 5-seater with 100 h.p. Anzani for French "Circuit of Anjou." 1914 produced the "scout" biplane which won at Vienna. 1915 appeared the twin-engined type, the first successful "battle-plane." [Illustration: Plate XVII.] THE DEPERDUSSIN.--In 1911 the little monoplane with a Gyp. engine. Then the Gnome-engined machine of the "Circuit of Europe." In 1912 came the Navy's machine with 70 h.p. Gnome, and Prevost's Gordon-Bennett "Bullet," 135 miles in the hour. The last was the British-built "Thunder-Bug," familiar at Hendon. [Illustration: Plate XVIII.] THE BREGUET.--First to fly was the complicated but business-like machine of 1909. Then came the record passenger carrier, 1910 (which lifted 8 passengers). 1911 the French Military Trials machine with geared-down 100 h.p. Gnome appeared. 1912 produced the machine with 130 h.p. Salmson engine on which the late Mr. Moorhouse flew the Channel with Mrs. Moorhouse and Mr. Ledeboer as passengers; also the machine with 130 h.p. horizontal Salmson, known as the "Whitebait." The last before the war was the rigid wing machine with 200 h.p. Salmson. [Illustration: Plate XIX.] THE CODY.--First the Military Experiment of 1908, with an Antoinette engine, then improved type 1909 with a Green engine. Next the "Cathedral," 1910, with a Green engine, which won Michelin Prize. In 1911 "Daily Mail" Circuit machine, also with a Green, won the Michelin. This was modified into 1912 type which won Military Competition and £5,000 in prizes, with an Austro-Daimler engine, and later the Michelin Circuit Prize, again with a Green. 1912 the only Cody Monoplane was built. 1913 a modified biplane on which the great pioneer was killed. [Illustration: Plate XX.] THE NIEUPORT.--The first Nieuport of 1909 was curiously like a monoplane version of a Caudron. In 1910 came the little two-cylinder machine with fixed tail-plane and universally jointed tail. In 1911 the French Trials machine was built with 100 h.p. 14 cylinder Gnome, and is typical of this make. Also the little two-cylinder record breaker. A modification of 1913 was the height record machine of the late M. Legagneux. [Illustration: Plate XXI.] THE R.E.P. MONOPLANES.--First came the curious and highly interesting experiments of 1907, 1908, 1909, and 1910. 1910-1911, the World's Distance Record breaker was produced; after it, the "European Circuit," all with R.E.P. engines. In 1913-14 came the French military type with Gnome engine and finally the "parasol," 1915. [Illustration: Plate XXII.] THE MORANE: First the European Circuit and Paris-Madrid type. Then the 1912 types, with taper wing and modern type wing. The 1913 types, the "clipped wing," flown by the late Mr. Hamel, one of the standard tandem types now in use. About the same time came the "parasol." 1914-15 came a little biplane like a Nieuport, and the "destroyer" type with a round section body, flown by Vedrines. [Illustration: Plate XXIII.] THE VOISIN.--1908, the first properly controlled flight on a European aeroplane was made on a Voisin of the type shown with fixed engine. Then followed the record breaker of 1909 with a Gnome engine. In 1909 also the only Voisin tractor was produced. 1910 the Paris-Bordeaux type was built; 1911 the amphibious "canard" and the "military" type with extensions, and the type without an elevator. 1913 came the type with only two tail-booms and a geared-down engine, which developed into the big "gun" machine with a Salmson engine. [Illustration: Plate XXIV.] THE HANRIOT AND PONNIER MONOPLANES.--In 1909 came the first Hanriot with 50 h.p. 6-cylinder Buchet engine, and in 1910 the famous "Henrietta" type with E.N.Vs. and stationary Clergets. 1911 came the Clerget two-seater entered in French Military Trials, and 1912 the 100 h.p. Hanriot-Pagny monoplane which took part in British Military Trials. Sister machines of the same year were the single seater with 50 h.p. Gnome and the 100 h.p. Gnome racer with stripped chassis. In 1913 the Ponnier-Pagny racing monoplane with 160 h.p. Le Rhone competed in the Gordon-Bennett race, doing about 130 miles in the hour. The 60 h.p. Ponnier biplane was the first successful French scout tractor biplane. [Illustration: Plate XXV.] THE WRIGHT BIPLANE.--The first power flights were made, 1903, on a converted glider fitted with 16 h.p. motor. The prone position of the pilot will be noted. By 1907 the machine had become reasonably practical with 40 h.p. motor. On this the first real flying in the world was done. In 1910 the miniature racing Wright was produced; also the type with a rear elevator in addition to one in front. Soon afterwards the front elevator disappeared, and the machine became the standard American exhibition and school machine for four years. In 1915 a machine with enclosed fuselage was produced. [Illustration: Plate XXVI.] THE BLACKBURN MONOPLANES.--In 1909 was built the curious four-wheeled parasol-type machine with 35 h.p. Green engine and chain transmission, on which flying was done at Saltburn. In 1911 the Isaacson-engined machine was built, together with a 50 h.p. Gnome single-seater on which Mr. Hucks started in the Circuit of Britain race. In 1912 another 50 h.p. single-seater was built on which a good deal of school work was done. A more advanced machine appeared in 1913 and a two-seater with 80 h.p. Gnome did a great deal of cross-country work in 1913-14. [Illustration: Plate XXVII.] In 1908 the first Antoinette monoplane was produced by MM. Gastambide and Mengin. Then followed a machine with central skids, a single wheel, and wing skids. In 1909 came the machine with four-wheeled chassis and ailerons and later an improved edition which reverted to the central skid idea. On this M. Latham made his first cross-channel attempt. The next machine shed the wing skids and widened its wheelbase. During 1910-11 the ailerons vanished, warp control was adopted and the king-post system of wing-bracing was used. In 1911 the curious machine with streamlined "pantalette" chassis, totally enclosed body and internal wing-bracing, was produced for French Military Trials. In 1912 the three-wheeled machine was used to a certain extent in the French Army. Then the type disappeared. [Illustration: Plate XXVIII.] In 1908 and 1909 detached experimental machines in various countries attained a certain success. The late Capt. Ferber made a primitive tractor biplane 1908. The Odier-Vendome biplane was a curious bat-winged pusher biplane built 1909. The tailless Etrich monoplane, built in Austria, 1908, was an adaptation of the Zanonia leaf. M. Santos-Dumont made primitive parasol type monoplanes known as "Demoiselles," in which bamboo was largely used. 1909 type is seen above. A curious steel monoplane was built by the late John Moisant, 1909. The twin-pusher biplane, built by the Barnwell Bros. in Scotland, made one or two straight flights in 1909. The Clement-Bayard Co. in France constructed in 1909 a biplane which did fairly well. Hans Grade, the first German to fly, made his early efforts on a "Demoiselle" type machine, 1908. [Illustration: Plate XXIX.] In 1910 a number of novel machines were produced. The Avis with Anzani engine was flown by the Hon. Alan Boyle. Note the cruciform universally jointed tail. The Goupy with 50 h.p. Gnome was an early French tractor, notable for its hinging wing-tips. The Farman was a curious "knock-up" job, chiefly composed of standard box-kite fittings. The Sommer with 50 h.p. Gnome was a development of the box-kite with a shock-breaking chassis. The Savary, also French, was one of the first twin tractors to fly. The model illustrated had an E.N.V. engine. Note position of the rudders on the wing tips. The Austrian Etrich was the first successful machine of the Taube class ever built. [Illustration: Plate XXX.] INTERESTING MACHINES, 1910.--The Werner monoplane with E.N.V. engine, combined shaft and chain drive, was a variant of the de Pischoff. The Macfie biplane was a conventional biplane with 50 h.p. Gnome and useful originalities. The Valkyrie monoplane, another British machine, was a "canard" monoplane with propeller behind the pilot and in front of main plane. The Weiss monoplane was a good British effort at inherent stability. The Tellier monoplane was a modified Bleriot with Antoinette proportions. The Howard Wright biplane was a pusher with large lifting monoplane tail. The Dunne biplane was another British attempt at inherent stability. The Jezzi biplane was an amateur built twin-propeller. [Illustration: Plate XXXI.] SOME INTERESTING MACHINES, 1911.--The Compton-Paterson biplane was very similar to the early Curtiss pusher; it had a 50 h.p. Gnome. The Sloan bicurve was a French attempt at inherent stability with 50 h.p. Gnome and tractor screw. The Paulhan biplane was an attempt at a machine for military purposes to fold up readily for transport. The Sanders was a British biplane intended for rough service. The Barnwell monoplane was the first Scottish machine to fly; it had a horizontally opposed Scottish engine. The Harlan monoplane was an early German effort; note position of petrol tank. [Illustration: Plate XXXII.] The Clement-Bayard monoplane, 1911, was convertible into a tractor biplane. The standard engine was a 50 h.p. Gnome. The machine was interesting, but never did much. The Zodiac was one of the earliest to employ staggered wings. With 50 h.p. Gnome engine it was badly underpowered, so never did itself justice. The Jezzi tractor biplane, 1911, was a development of an earlier model built entirely by Mr. Jezzi, an amateur constructor. With a low-powered J.A.P. engine it developed an amazing turn of speed, and it may be regarded as a forerunner of the scout type and the properly streamlined aeroplane. The Paulhan-Tatin monoplane, 1911, was a brilliant attempt at high speed for low power; it presented certain advantages as a scout. A 50 h.p. Gnome, fitted behind the pilot's seat in the streamlined fuselage, was cooled through louvres. The propeller at the end of the tail was connected with the engine by a flexible coupling. This machine was, in its day, the fastest for its power in the world, doing 80 miles per hour. Viking 1 was a twin tractor biplane driven by a 50 h.p. Gnome engine through chains. It was built by the author at Hendon in 1912. [Illustration: Plate XXXIII.] Much ingenuity was exerted by the French designers in 1911 to produce machines for the Military Trials. Among them was the 100 h.p. Gnome-Borel monoplane with a four-wheeled chassis, and the Astra triplane with a 75 h.p. Renault engine. This last had a surface of about 500 square feet and presented considerable possibilities. Its principal feature was its enormous wheels with large size tyres as an attempt to solve difficulties of the severe landing tests. The Clement-Bayard biplane was a further development of the Clement-Bayard monoplane; the type represented could be converted into a monoplane at will. The Lohner Arrow biplane with the Daimler engine was an early German tractor biplane built with a view to inherent stability, and proved very successful. The Pivot monoplane was of somewhat unconventional French construction, chiefly notable for the special spring chassis and pivoted ailerons at the main planes; this pivoting had nothing to do with the name of the machine, which was designed by M. Pivot. [Illustration: Plate XXXIV.] The Flanders monoplane, 1912, with 70 h.p. Renault engine, was one of the last fitted with king-post system of wing bracing. The Flanders biplane entered for British Military Trials. Notable features: the highly staggered planes, extremely low chassis and deep fuselage. Also, the upper plane was bigger in every dimension than the lower; about the first instance of this practice. The Bristol biplane, with 100 h.p. Gnome engine, was also entered for the Trials, but ultimately withdrawn. The Mars monoplane, later known as the "D.F.W.," was a successful machine of Taube type with 120 h.p. Austro-Daimler engine. The building of the engine into a cowl, complete with radiator in front, followed car practice very closely. The tail of the monoplane had a flexible trailing edge; its angle of incidence could be varied from the pilot's seat, so that perfect longitudinal balance was attained at all loadings and speeds. The Handley-Page monoplane, with 70 h.p. Gnome engine, was an early successful British attempt at inherent stability. [Illustration: Plate XXXV.] The Sommer monoplane, with 50 h.p. Gnome, was a 1911-12 machine; it did a good deal of cross-country flying. The Vendome monoplane of 1912, also with 50 h.p. Gnome engine, was notable chiefly for its large wheels and jointed fuselage, which enabled the machine to be taken down for transport. The Savary biplane took part in the French Military Trials, 1911. It had a four-cylinder Labor aviation motor. Notable features are twin chain-driven propellers, rudders between the main planes, the broad wheel-base and the position of the pilot. The Paulhan triplane, which also figured in the French Military Trials, was a development of the Paulhan folding biplane. It had a 70 h.p. Renault engine. For practical purposes it was a failure. The R.E.P. biplane, with 60 h.p. R.E.P. engine, was a development of the famous R.E.P. monoplanes. Its spring chassis, with sliding joints, marked an advance. Like the monoplanes, it was built largely of steel. [Illustration: Plate XXXVI.] In 1912 came the first really successful Handley-Page monoplane, with 50 h.p. Gnome engine. The Short monoplane, was built generally on Bleriot lines. Its chassis was an original feature. The Coventry Ordnance biplane was a two-seater tractor built for the British Military Trials. It had a 100 h.p. 14-cylinder Gnome engine, with propeller geared down through a chain drive. The machine was an interesting experiment, but not an unqualified success. The Moreau "Aerostable," fitted with a 50 h.p. Gnome, was a French attempt to obtain automatic stability, but it only operated longitudinally. The pilot's nacelle was pivoted under the main planes, wires were attached to the control members so that the movements of the nacelle in its efforts to keep a level keel brought them into operation. The Mersey monoplane, an entrant for the British Military Trials, was designed to present a clear field of view and fire. The 45 h.p. Isaacson engine was connected by a shaft to a propeller mounted behind the nacelle on the top tail boom. It was a promising experiment, but came to grief. The Radley-Moorhouse monoplane was a sporting type machine on Bleriot lines, with 50 h.p. Gnome engine. It was notable for its streamlined body and disc wheels. 
793	----	AEROPLANES AND DIRIGIBLES OF WAR By Frederick A. Talbot PREFACE Ever since the earliest days of the great conquest of the air, first by the dirigible balloon and then by the aeroplane, their use in time of war has been a fruitful theme for discussion. But their arrival was of too recent a date, their many utilities too unexplored to provide anything other than theories, many obviously untenable, others avowedly problematical. Yet the part airships have played in the Greatest War has come as a surprise even to their most convinced advocates. For every expectation shattered, they have shown a more than compensating possibility of usefulness. In this volume an endeavour has been made to record their achievements, under the stern test of trial, as an axiom of war, and to explain, in untechnical language, the many services to which they have been and may be applied. In the preparation of the work I have received assistance from many sources--British, French, Russian and German--from official reports and from men who have played a part in the War in the Air. The information concerning German military aircraft has been obtained from Government documents, most of which were placed at my disposal before the outbreak of war. The use of aircraft has changed the whole art and science of warfare. With its disabilities well in hand, with its strength but half revealed, the aerial service has revolutionised strategy and shorn the unexpected attack of half its terrors. The Fourth Arm is now an invaluable part of the complex military machine. F. A. TALBOT. CONTENTS CHAPTER I. The introduction of aircraft into military operations II. The military uses of the captive balloon III. Germany's rise to military airship supremacy IV. Airships of war V. Germany's aerial dreadnought fleet VI. The military value of Germany's aerial fleet VII. Aeroplanes of war VIII. Scouting from the skies IX. The airman and artillery X. Bomb-throwing from air-craft XI. Armoured aeroplanes XII. Battles in the air XIII. Tricks and ruses to baffle the airman XIV. Anti-aircraft guns. Mobile weapons XV. Anti-aircraft guns. Immobile weapons XVI. Mining the air XVII. Wireless in aviation XVIII. Aircraft and naval operations XIX. The navies of the air CHAPTER I. THE INTRODUCTION OF AIRCRAFT INTO MILITARY OPERATIONS It is a curious circumstance that an invention, which is hailed as being one of the greatest achievements ever recorded in the march of civilisation, should be devoted essentially to the maiming of humanity and the destruction of property. In no other trend of human endeavour is this factor so potently demonstrated as in connection with Man's Conquest of the Air. The dogged struggle against the blind forces of Nature was waged tenaciously and perseveringly for centuries. But the measure of success recorded from time to time was so disappointing as to convey the impression, except in a limited circle, that the problem was impossible of solution. In the meantime wondrous changes had taken place in the methods of transportation by land and sea. The steam and electric railway, steam propulsion of vessels, and mechanical movement along the highroads had been evolved and advanced to a high standard of perfection, to the untold advantage of the community. Consequently it was argued, if only a system of travel along the aerial highways could be established, then all other methods of mechanical transportation would be rendered, if not entirely obsolete, at least antiquated. At last man triumphed over Nature--at least to such a degree as to inspire the confidence of the world at large, and to bring aerial travel and transportation within range of realisation. But what has been the result? The discovery is not devoted to the interests of peace and economic development, but to extermination and destruction. At the same time this development may be explained. The airship and aeroplane in the present stage of evolution possess no economic value. True, cross-country cruises by airship have been inaugurated, and, up to a point, have proved popularly, if not commercially, successful, while tentative efforts have been made to utilise the aeroplane as a mail-carrier. Still, from the view-point of the community at large aerial travel is as remote as it was centuries ago. It is somewhat interesting to observe how history is repeating itself. When the Montgolfiers succeeded in lifting themselves into the air by means of a vessel inflated with hot air, the new vehicle was hailed not so much as one possessed of commercial possibilities, but as an engine of war! When the indomitable courage and perseverance of Count von Zeppelin in the face of discouraging disasters and flagrant failures, at last commanded the attention of the German Emperor, the latter regarded the Zeppelin craft, not from the interests of peace, but as a military weapon, and the whole of the subsequent efforts of the Imperial admirer were devoted to the perfection of the airship in this one direction. Other nations, when they embarked on an identical line of development, considered the airship from a similar point of view. In fact, outside Germany, there was very little private initiative in this field. Experiments and developments were undertaken by the military or naval, and in some instances by both branches, of the respective Powers. Consequently the aerial craft, whether it be a dirigible airship, or an aeroplane, can only be regarded from the military point of view. Despite the achievements which have been recorded by human endeavour in the field of aerial travel, the balloon per se has by no means been superseded. It still remains an invaluable adjunct to the fighting machine. In Great Britain its value in this direction has never been ignored: of late, indeed, it has rather been developed. The captive balloon is regarded as an indispensable unit to both field and sea operations. This fact was emphasised very strongly in connection with the British naval attacks upon the German forces in Flanders, and it contributed to the discomfiture of the German hordes in a very emphatic manner. The captive balloon may be operated from any spot where facilities exist for anchoring the paying out cable together with winding facilities for the latter. Consequently, if exigencies demand, it maybe operated from the deck of a warship so long as the latter is stationary, or even from an automobile. It is of small cubic capacity, inasmuch as it is only necessary for the bag to contain sufficient gas to lift one or two men to a height of about 500 or 600 feet. When used in the field the balloon is generally inflated at the base, to be towed or carried forward by a squad of men while floating in the air, perhaps at a height of 10 feet. A dozen men will suffice for this duty as a rule, and in calm weather little difficulty is encountered in moving from point to point. This method possesses many advantages. The balloon can be inflated with greater ease at the base, where it is immune from interference by hostile fire. Moreover, the facilities for obtaining the requisite inflating agent--hydrogen or coal gas--are more convenient at such a point. If the base be far removed from the spot at which it is desired to operate the balloon, the latter is inflated at a convenient point nearer the requisite position, advantage being taken of the protective covering offered by a copse or other natural obstacle. As is well known, balloons played an important part during the siege of Paris in 1870-1, not only in connection with daring attempts to communicate with the outer world, but in reconnoitring the German positions around the beleaguered city. But this was not the first military application of the aerial vessel; it was used by the French against the Austrians in the battle of Fleurus, and also during the American Civil War. These operations, however, were of a sporadic character; they were not part and parcel of an organised military section. It is not generally known that the British War office virtually pioneered the military use of balloons, and subsequently the methods perfected in Britain became recognised as a kind of "standard" and were adopted generally by the Powers with such modifications as local exigencies seemed to demand. The British military balloon department was inaugurated at Chatham under Captain Templer in 1879. It was devoted essentially to the employment of captive balloons in war, and in 1880 a company of the Royal Engineers was detailed to the care of this work in the field. Six years previously the French military department had adopted the captive balloon under Colonel Laussedat, who was assisted among others by the well-known Captain Renard. Germany was somewhat later in the field; the military value of captive balloons was not appreciated and taken into serious consideration here until 1884. But although British efforts were preceded by the French the latter did not develop the idea upon accepted military lines. The British authorities were confronted with many searching problems. One of the earliest and greatest difficulties encountered was in connection with the gas for inflation. Coal gas was not always readily available, so that hydrogen had to be depended upon for the most part. But then another difficulty arose. This was the manufacture of the requisite gas. Various methods were tested, such as the electrolytic decomposition of water, the decomposition of sulphuric acid by means of iron, the reaction between slaked lime and zinc, and so forth. But the drawbacks to every process, especially upon the field of battle, when operations have to be conducted under extreme difficulties and at high pressure, were speedily recognised. While other nations concentrated their energies upon the simplification of hydrogen-manufacturing apparatus for use upon the battle-field, Great Britain abandoned all such processes in toto. Our military organisation preferred to carry out the production of the necessary gas at a convenient manufacturing centre and to transport it, stored in steel cylinders under pressure, to the actual scene of operations. The method proved a great success, and in this way it was found possible to inflate a military balloon in the short space of 20 minutes, whereas, under the conditions of making gas upon the spot, a period of four hours or more was necessary, owing to the fact that the manufacturing process is relatively slow and intricate. The practicability of the British idea and its perfection served to establish the captive balloon as a military unit. The British military ballooning department has always ranked as the foremost of its type among the Powers, although its work has been carried out so unostentatiously that the outside world has gleaned very little information concerning its operations. Captain Templer was an indefatigable worker and he brought the ballooning section to a high degree of efficiency from the military point of view. But the British Government was peculiarly favoured, if such a term may be used. Our little wars in various parts of the world contributed valuable information and experience which was fully turned to account. Captive balloons for reconnoitring purposes were used by the British army for the first time at Suakim in 1885, and the section established its value very convincingly. The French military balloon department gained its first experience in this field in the previous year, a balloon detachment having been dispatched to Tonkin in 1884. In both the Tonkin and Soudan campaigns, invaluable work was accomplished by the balloon sections, with the result that this aerial vehicle has come to be regarded as an indispensable military adjunct. Indeed the activity of the German military ballooning section was directly attributable to the Anglo-French achievements therewith. In this work, however, the British force speedily displayed its superiority and initiative. The use of compressed hydrogen was adopted, and within the course of a few years the other Powers, realising the advantages which the British department had thus obtained, decided to follow its example. The gas is stored in cylinders under a pressure varying from six to ten or more atmospheres; in other words from about 80 to 140 or more pounds per square inch. Special military wagons have been designed for the transport of these cylinders, and they are attached to the balloon train. The balloon itself is light, and made of such materials as to reduce the weight thereof to the minimum. The British balloons are probably the smallest used by any of the Powers, but at the same time they are the most expensive. They are made of goldbeater's skin, and range in capacity from 7,000 to 10,000 cubic feet, the majority being of the former capacity. The French balloon on the other hand has a capacity exceeding 18,000 cubic feet, although a smaller vessel of 9,000 cubic feet capacity, known as an auxiliary, and carrying a single observer, is used. The Germans, on the other hand, with their Teutonic love of the immense, favour far larger vessels. At the same time the military balloon section of the German Army eclipses that of any other nations is attached to the Intelligence Department, and is under the direct control of the General Staff. Balloon stations are dotted all over the country, including Heligoland and Kiel, while regular sections are attached to the Navy for operating captive balloons from warships. Although the Zeppelin and aeroplane forces have come to the front in Germany, and have relegated the captive balloon somewhat to the limbo of things that were, the latter section has never been disbanded; in fact, during the present campaign it has undergone a somewhat spirited revival. The South African campaign emphasised the value of the British balloon section of the Army, and revealed services to which it was specially adapted, but which had previously more or less been ignored. The British Army possessed indifferent maps of the Orange Free State and the Transvaal. This lamentable deficiency was remedied in great measure by recourse to topographical photographs taken from the captive balloons. The guides thus obtained were found to be of extreme value. During the early stages of the war the hydrogen was shipped in cylinders from the homeland, but subsequently a manufacturing plant of such capacity as to meet all requirements was established in South Africa. The cylinders were charged at this point and dispatched to the scene of action, so that it became unnecessary to transport the commodity from Britain. The captive balloon revealed the impregnability of Spion Kop, enabled Lord Roberts to ascertain the position of the Boer guns at the Battle of Paardeburg, and proved of invaluable assistance to the forces of General White during the siege of Ladysmith. CHAPTER II. THE MILITARY USES of THE CAPTIVE BALLOON Although the captive balloon is recognised as indispensable in military operations, its uses are somewhat limited. It can be employed only in comparatively still weather. The reason is obvious. It is essential that the balloon should assume a vertical line in relation to its winding plant upon the ground beneath, so that it may attain the maximum elevation possible: in other words, the balloon should be directly above the station below, so that if 100 yards of cable are paid out the aerostat may be 100 yards above the ground. If a wind is blowing, the helpless craft is certain to be caught thereby and driven forwards or backwards, so that it assumes an angle to its station. If this become acute the vessel will be tilted, rendering the position of the observers somewhat precarious, and at the same time observing efficiency will be impaired. This point may be appreciated more easily by reference to the accompanying diagram. A represents the ground station and B the position of the captive balloon when sent aloft in calm weather, 300 feet of cable being paid out. A wind arises and blows the vessel forward to the position C. At this point the height of the craft in relation to the ground has been reduced, and the reduction must increase proportionately as the strength of the wind increases and forces the balloon still more towards the ground. At the same time, owing to the tilt given to the car, observation is rendered more difficult and eventually becomes extremely dangerous. A wind, if of appreciable strength, develops another and graver danger. Greater strain will be imposed upon the cable, while if the wind be gusty, there is the risk that the vessel will be torn away from its anchoring rope and possibly lost. Thus it will be seen that the effective utilisation of a captive balloon is completely governed by meteorological conditions, and often it is impossible to use it in weather which exercises but little influence upon dirigibles or aeroplanes. The captive balloon equipment comprises the balloon, together with the observer's basket, the wire-cable whereby it is anchored and controlled, and the winding apparatus. Formerly a steam engine was necessary for the paying in and out of the cable, but nowadays this is accomplished by means of a petrol-driven motor, an oil-engine, or even by the engine of an automobile. The length of cable varies according to the capacity of the balloon and the maximum operating height. The average British balloon is able to lift about 290 or 300 pounds, which may be taken to represent the weight of two observers. On the other hand, the French and German balloons are able to carry four times this weight, with the exception of the French auxiliaries, which are designed to lift one observer only. The balloons of the two latter Powers have also a greater maximum altitude; it is possible to ascend to a height of some 2,000 feet in one of these. The observing station is connected with the winding crew below either by a telephone, or some other signalling system, the method practised varying according to circumstances. In turn the winding station is connected with the officer in charge of the artillery, the fire of which the captive balloon is directing. The balloon observer is generally equipped with various instruments, such as telescope, photographic cameras, and so forth, so as to be able, if necessary, to prepare a topographical survey of the country below. By this means the absence of reliable maps may be remedied, or if not regarded, as sufficiently correct they may be checked and counter-checked by the data gained aloft. Seeing that the gas has to be transported in cylinders, which are weighty, it is incumbent that the waste of this commodity should be reduced to the minimum. The balloon cannot be deflated at night and re-inflated in the morning--it must be maintained in the inflated condition the whole time it is required for operation. There are various methods of consummating this end. One method is to haul in the balloon and to peg it down on all sides, completing the anchorage by the attachment of bags filled with earth to the network. While this process is satisfactory in calm weather, it is impracticable in heavy winds, which are likely to spring up suddenly. Consequently a second method is practised. This is to dig a pit into the ground of sufficient size to receive the balloon. When the latter is hauled in it is lowered into this pit and there pegged down and anchored. Thus it is perfectly safe during the roughest weather, as none of its bulk is exposed above the ground level. Furthermore it is not a conspicuous object for the concentration of hostile fire. In some instances, and where the military department is possessed of an elaborate equipment such as characterises the German army, when reconnaissance is completed and the balloon is to be removed to another point, the gas is pumped back into the cylinders for further use. Such an economical proceeding is pretty and well adapted to manoeuvres, but it is scarcely feasible in actual warfare, for the simple reason that the pumping takes time. Consequently the general procedure, when the balloon has completed its work, is to permit the gas to escape into the air in the usual manner, and to draw a fresh supply of gas from further cylinders when the occasion arises for re-inflation. Although the familiar spherical balloon has proved perfectly adequate for reconnoitring in the British and French armies, the German authorities maintained that it was not satisfactory in anything but calm weather. Accordingly scientific initiative was stimulated with a view to the evolution of a superior vessel. These endeavours culminated in the Parseval-Siegsfeld captive balloon, which has a quaint appearance. It has the form of a bulky cylinder with hemispherical extremities. At one end of the balloon there is a surrounding outer bag, reminiscent of a cancerous growth. The lower end of this is open. This attachment serves the purpose of a ballonet. The wind blowing against the opening, which faces it, charges the ballonet with air. This action, it is claimed, serves to steady the main vessel, somewhat in the manner of the tail of a kite, thereby enabling observations to be made as easily and correctly in rough as in calm weather. The appearance of the balloon while aloft is certainly curious. It appears to be rearing up on end, as if the extremity saddled with the ballonet were weighted. British and French captive balloon authorities are disposed to discount the steadying effect of this attachment, and, indeed, to maintain that it is a distinct disadvantage. It may hold the vessel steadier for the purpose of observation, but at the same time it renders the balloon a steadier target for hostile fire. On the other hand, the swaying of a spherical balloon with the wind materially contributes to its safety. A moving object, particularly when its oscillations are irregular and incalculable, is an extremely difficult object at which to take effective aim. Seeing that even a small captive balloon is of appreciable dimensions--from 25 to 33 feet or more in diameter--one might consider it an easy object to hit. But experience has proved otherwise. In the first place the colour of the balloon is distinctly protective. The golden or yellowish tinge harmonises well with the daylight, even in gloomy weather, while at night-time it blends excellently with the moonlight. For effective observations a high altitude is undesirable. At a height of 600 feet the horizon is about 28 miles from the observer, as compared with the 3 miles constituting the range of vision from the ground over perfectly flat country. Thus it will be seen that the "spotter" up aloft has the command of a considerable tract. Various ways and means of finding the range of a captive balloon have been prepared, and tables innumerable are available for committal to memory, while those weapons especially designed for aerial targets are fitted with excellent range-finders and other instruments. The Germans, with characteristic thoroughness, have devoted considerable attention to this subject, but from the results which they have achieved up to the present this guiding knowledge appears to be more spectacular and impressive than effective. To put a captive balloon out of action one must either riddle the envelope, causing it to leak like a sieve, blow the vessel to pieces, or ignite the highly inflammable gas with which it is inflated. Individual rifle fire will inflict no tangible damage. A bullet, if it finds its billet, will merely pass through the envelope and leave two small punctures. True, these vents will allow the gas to escape, but this action will proceed so slowly as to permit the vessel to remain aloft long enough to enable the observer to complete his work. A lucky rifle volley, or the stream of bullets from a machine gun may riddle the envelope, precipitating a hurried descent, owing to the greater number of perforations through which the gas is able to escape, but as a rule the observer will be able to land safely. Consequently the general practice is to shatter the aerostat, and to this end either shrapnel, high explosive, or incendiary shells will be used. The former must explode quite close to the balloon in order to achieve the desired end, while the incendiary shell must actually strike it, so as to fire the gas. The high explosive shell may explode effectually some feet away from the vessel, inasmuch as in this instance dependence is placed upon the terrific concussion produced by the explosion which, acting upon the fragile fabric of the balloon, brings about a complete collapse of the envelope. If a shrapnel is well placed and explodes immediately above the balloon, the envelope will be torn to shreds and a violent explosion of the gas will be precipitated. But as a matter of fact, it is extremely difficult to place a shrapnel shell so as to consummate this end. The range is not picked up easily, while the timing of the fuse to bring about the explosion of the shell at the critical moment is invariably a complex problem. One favourite method of finding the range of a balloon is shown in the accompanying diagrams. The artillery battery is at B and the captive balloon, C, is anchored at A. On either side of B and at a specified distance, observers O1 and O2 respectively are stationed. First a shell is fired at "long" range, possibly the maximum range of the gun. It bursts at D. As it has burst immediately in the line of sight of B, but with the smoke obscured by the figure of the balloon C, it is obvious to B that the explosion has occurred behind the objective, but at what distance he cannot tell. To O1 and O2, however, it is seen to have burst at a considerable distance behind C though to the former it appears to have burst to the left and to the second observer to the right of the target. Another shell, at "short" range, is now fired, and it bursts at E. The explosion takes place in the line of sight of B, who knows that he has fired short of the balloon because the latter is eclipsed by the smoke. But the two observers see that it is very short, and here again the explosion appears to O1 to have occurred to the right of the target, while to O2 it has evidently burst to the left of the aerostat, as revealed by the relation of the position of the balloon to the bursting of the shell shown in Fig. 3. A third round is fired, and the shell explodes at F. In this instance the explosion takes place below the balloon. Both the observers and the artillery man concur in their deductions upon the point at which the shell burst. But the shell must explode above the balloon, and accordingly a fourth round is discharged and the shell bursts at G. This appears to be above the balloon, inasmuch as the lines of sight of the two observers and B converge at this point. But whether the explosion occurs immediately above the vessel as is desired, it is impossible to say definitely, because it may explode too far behind to be effective. Consequently, if this shell should prove abortive, the practice is to decrease the range gradually with each succeeding round until the explosion occurs at the critical point, when, of course, the balloon is destroyed. An interesting idea of the difficulty of picking up the range of a captive balloon may be gathered from the fact that some ten minutes are required to complete the operation. But success is due more to luck than judgment. In the foregoing explanation it is premised that the aerial vessel remains stationary, which is an extremely unlikely contingency. While those upon the ground are striving to pick up the range, the observer is equally active in his efforts to baffle his opponents. The observer follows each successive, round with keen interest, and when the shells appear to be bursting at uncomfortably close quarters naturally he intimates to his colleagues below that he desires his position to be changed, either by ascending to a higher point or descending. In fact, he may be content to come to the ground. Nor must the fact be overlooked that while the enemy is trying to place the observer hors de combat, he is revealing the position of his artillery, and the observer is equally industrious in picking up the range of the hostile guns for the benefit of his friends below. When the captive balloon is aloft in a wind the chances of the enemy picking up the range thereof are extremely slender, as it is continually swinging to and fro. While there is always the possibility of a shell bursting at such a lucky moment as to demolish the aerial target, it is generally conceded to be impossible to induce a shell to burst within 100 yards of a balloon, no matter how skilfully the hostile battery may be operated. The value of the captive balloon has been demonstrated very strikingly throughout the attack upon the entrenched German positions in Flanders. Owing to the undulating character of the dunes the "spotters" upon the British monitors and battle ships are unable to obtain a sweeping view of the country. Accordingly captive balloons are sent aloft in some cases from the deck of the monitors, and in others from a suitable point upon the beach itself. The aerial observer from his point of vantage is able to pick up the positions of the German forces and artillery with ease and to communicate the data thus gained to the British vessels, although subjected to heavy and continuous hostile fire. The difficulty of hitting a captive balloon has been graphically emphasised, inasmuch as the German artillerists have failed to bring down a solitary balloon. On the other hand the observer in the air is able to signal the results of each salvo fired from the British battleships as they manoeuvre at full speed up and down the coastline, while he keeps the fire of the monitors concentrated upon the German positions until the latter have been rendered untenable or demolished. The accuracy of the British gun-fire has astonished even the Germans, but it has been directly attributable to the rangefinder perched in the car of the captive balloon and his rapid transmission of information to the vessels below. The enthusiastic supporters of aerial navigation maintained that the dirigible and the aeroplane would supersede the captive balloon completely. But as a matter of fact the present conflict has established the value of this factor more firmly than ever. There is not the slightest possibility that the captive balloon sections of the belligerents will be disbanded, especially those which have the fruits of experience to guide them. The airship and the aeroplane have accomplished wonders, but despite their achievements the captive balloon has fully substantiated its value as a military unit in its particular field of operations. CHAPTER III. GERMANY'S RISE TO MILITARY AIRSHIP SUPREMACY Two incidents in the history of aviation stand out with exceptional prominence. The one is the evolution of the Zeppelin airship--a story teeming with romance and affording striking and illuminating glimpses of dogged perseverance, grim determination in the face of repeated disasters, and the blind courageous faith of the inventor in the creation of his own brain. The second is the remarkable growth of Germany's military airship organisation, which has been so rapid and complete as to enable her to assume supremacy in this field, and that within the short span of a single decade. The Zeppelin has always aroused the world's attention, although this interest has fluctuated. Regarded at first as a wonderful achievement of genius, afterwards as a freak, then as the ready butt for universal ridicule, and finally with awe, if not with absolute terror--such in brief is the history of this craft of the air. Count von Zeppelin can scarcely be regarded as an ordinary man. He took up the subject of flight at an age which the majority of individuals regard as the opportune moment for retirement from activity, and, knowing nothing about mechanical engineering, he concentrated his energies upon the study of this science to enable him to master the difficulties of a mechanical character incidental to the realisation of his grand idea. His energy and indomitable perseverance are equalled by his ardent patriotism, because, although the Fatherland discounted his idea when other Powers were ready to consider it, and indeed made him tempting offers for the acquisition of his handiwork, he stoutly declined all such solicitations, declaring that his invention, if such it may be termed, was for his own country and none other. Count von Zeppelin developed his line of study and thought for one reason only. As an old campaigner and a student of military affairs he realised the shortcomings of the existing methods of scouting and reconnoitring. He appreciated more than any other man of the day perhaps, that if the commander-in-chief of an army were provided with facilities for gazing down upon the scene of operations, and were able to take advantage of all the information accruing to the man above who sees all, he would hold a superior position, and be able to dispose his forces and to arrange his plan of campaign to the most decisive advantage. In other words, Zeppelin conceived and developed his airship for one field of application and that alone-military operations. Although it has achieved certain successes in other directions these have been subsidiary to the primary intention, and have merely served to emphasise its military value. Von Zeppelin was handicapped in his line of thought and investigation from the very first. He dreamed big things upon a big scale. The colossal always makes a peculiar and irresistible appeal to the Teutonic nature. So he contemplated the perfection of a big dirigible, eclipsing in every respect anything ever attempted or likely to be attempted by rival countries. Unfortunately, the realisation of the "colossal" entails an equally colossal financial reserve, and the creator of this form of airship for years suffered from financial cramp in its worst manifestation. Probably it was to the benefit of the world at large that Fortune played him such sorry tricks. It retarded the growth of German ambitions in one direction very effectively. As is well known Zeppelin evolved what may be termed an individual line of thought in connection with his airship activities. He adopted what is known as the indeformable airship: that is to say the rigid, as opposed to the semi-rigid and flexible craft. As a result of patient experiment and continued researches he came to the conclusion that a huge outer envelope taking the form of a polygonal cylinder with hemispherical ends, constructed upon substantial lines with a metallic skeleton encased within an impermeable skin, and charged with a number of smaller balloon-shaped vessels containing the lifting agent--hydrogen gas--would fulfil his requirements to the greatest advantage. Model after model was built upon these lines. Each was subjected to searching tests with the invariable result attending such work with models. Some fulfilled the expectations of the inventor, others resolutely declined to illustrate his reasonings in any direction. The inevitable happened. When a promising model was completed finally the inventor learned to his sorrow what every inventor realises in time. His fortune and the resources of others had been poured down the sink of experiment. To carry the idea from the model to the practical stage required more money, and it was not forthcoming. The inventor sought to enlist the practical sympathy of his country, only to learn that in Germany, as in other lands, the axiom concerning the prophet, honour, and country prevails. No exuberant inventor received such a cold douche from a Government as did Count Zeppelin from the Prussian authorities. For two years further work was brought practically to a standstill: nothing could be done unless the sinews of war were forthcoming. His friends, who had assisted him financially with his models, now concluded that their aid had been misplaced. The inventor, though disappointed, was by no means cast down. He clung tenaciously to his pet scheme and to such effect that in 1896 a German Engineering Society advanced him some funds to continue his researches. This support sufficed to keep things going for another two years, during which time a full-sized vessel was built. The grand idea began to crystallise rapidly, with the result that when a public company was formed in 1898, sufficient funds were rendered available to enable the first craft to be constructed. It aroused considerable attention, as well it might, seeing that it eclipsed anything which had previously been attempted in connection with dirigibles. It was no less than 420 feet in length, by 38 feet in diameter, and was fitted with two cars, each of which carried a sixteen horse-power motor driving independent propellers rigidly attached to the body of the vessel. The propellers were both vertical and horizontal, for the purpose of driving the ship in the two planes--vertical and horizontal respectively. The vessel was of great scientific interest, owing to the ingenuity of its design and construction. The metallic skeleton was built up from aluminium and over this was stretched the fabric of the envelope, care being observed to reduce skin friction, as well as to achieve impermeability. But it was the internal arrangement of the gas-lifting balloons which provoked the greatest concern. The hull was divided into compartments, each complete in itself, and each containing a small balloon inflated with hydrogen. It was sub-division as practised in connection with vessels ploughing the water applied to aerial craft, the purpose being somewhat the same. As a ship of the seas will keep afloat so long as a certain number of its subdivisions remain watertight, so would the Zeppelin keep aloft if a certain number of the gas compartments retained their charges of hydrogen. There were no fewer than seventeen of these gas-balloons arranged in a single line within the envelope. Beneath the hull and extending the full length of the latter was a passage which not only served as a corridor for communication between the cars, but also to receive a weight attached to a cable worked by a winch. By the movement of this weight the bow or stem of the vessel could be tilted to assist ascent and descent. The construction of the vessel subsequently proved to be the easiest and most straightforward part of the whole undertaking. There were other and more serious problems to be solved. How would such a monster craft come to earth? How could she be manipulated upon the ground? How could she be docked? Upon these three points previous experience was silent. One German inventor who likewise had dreamed big things, and had carried them into execution, paid for his temerity and ambitions with his life, while his craft was reduced to a mass of twisted and torn metal. Under these circumstances Count Zeppelin decided to carry out his flights over the waters of the Bodensee and to house his craft within a floating dock. In this manner two uncertain factors might be effectively subjugated. Another problem had been ingeniously overcome. The outer envelope presented an immense surface to the atmosphere, while temperature was certain to play an uncertain part in the behaviour of the craft. The question was to reduce to the minimum the radiation of heat and cold to the bags containing the gas. This end was achieved by leaving a slight air space between the inflated gas balloons and the inner surface of the hull. The first ascent was made on July 2nd, 1900, but was disappointing, several breakdowns of the mechanism occurring while the vessel was in mid-air, which rendered it unmanageable, although a short flight was made which sufficed to show that an independent speed of 13 feet per second could be attained. The vessel descended and was made fast in her dock, the descent being effected safely, while manoeuvring into dock was successful. At least three points about which the inventor had been in doubt appeared to be solved--his airship could be driven through the air and could be steered; it could be brought to earth safely; and it could be docked. The repairs to the mechanism were carried out and on October 17th and 21st of the same year further flights were made. By this time certain influential Teuton aeronautical experts who had previously ridiculed Zeppelin's idea had made a perfect volte-face. They became staunch admirers of the system, while other meteorological savants participated in the trials for the express purpose of ascertaining just what the ship could do. As a result of elaborate trigonometrical calculations it was ascertained that the airship attained an independent speed of 30 feet per second, which exceeded anything previously achieved. The craft proved to be perfectly manageable in the air, and answered her helm, thus complying with the terms of dirigibility. The creator was flushed with his triumph, but at the same time was doomed to experience misfortune. In its descent the airship came to "earth" with such a shock that it was extensively damaged. The cost of repairing the vessel was so heavy that the company declined to shoulder the liability, and as the Count was unable to defray the expense the wreck was abandoned. Although a certain meed of success had been achieved the outlook seemed very black for the inventor. No one had any faith in his idea. He made imploring appeals for further money, embarked upon lecturing campaigns, wrote aviation articles for the Press, and canvassed possible supporters in the effort to raise funds for his next enterprise. Two years passed, but the fruits of the propaganda were meagre. It was at this juncture, when everything appeared to be impossible, that Count Zeppelin discovered his greatest friend. The German Emperor, with an eye ever fixed upon new developments, had followed Zeppelin's uphill struggle, and at last, in 1902, came to his aid by writing a letter which ran:-- "Since your varied flights have been reported to me it is a great pleasure to me to express my acknowledgment of your patience and your labours, and the endurance with which you have pressed on through manifold hindrances till success was near. The advantages of your system have given your ship the greatest attainable speed and dirigibility, and the important results you have obtained have produced an epoch-making step forward in the construction of airships and leave laid down a valuable basis for future experiments." This Imperial appreciation of what had been accomplished proved to be the turning point in the inventor's fortunes. It stimulated financial support, and the second airship was taken in hand. But misfortune still pursued him. Accidents were of almost daily occurrence. Defects were revealed here and weaknesses somewhere else. So soon as one trouble was overcome another made itself manifest. The result was that the whole of the money collected by his hard work was expended before the ship could take to the air. A further crash and blasting of cherished hopes appeared imminent, but at this moment another Royal personage came to the inventor's aid. The King of Wurtemberg took a personal interest in his subject's uphill struggle, and the Wurtemberg Government granted him the proceeds of a lottery. With this money, and with what he succeeded in raising by hook and by crook, and by mortgaging his remaining property, a round L20,000 was obtained. With this capital a third ship was taken in hand, and in 1905 it was launched. It was a distinct improvement upon its predecessors. The airship was 414 feet in length by 38 feet in diameter, was equipped with 17 gas balloons having an aggregate capacity of 367,000 cubic feet of hydrogen, was equipped with two 85 horse-power motors driving four propellers, and displaced 9 tons. All the imperfections incidental to the previous craft had been eliminated, while the ship followed improved lines in its mechanical and structural details. The trials with this vessel commenced on November 30th, 1905, but ill-luck had not been eluded. The airship was moored upon a raft which was to be towed out into the lake to enable the dirigible to ascend. But something went wrong with the arrangements. A strong wind caught the ungainly airship, she dipped her nose into the water, and as the motor was set going she was driven deeper into the lake, the vessel only being saved by hurried deflation. Six weeks were occupied in repairs, but another ascent was made on January 17th, 1906. The trials were fairly satisfactory, but inconclusive. One of the motors went wrong, and the longitudinal stability was found to be indifferent. The vessel was brought down, and was to be anchored, but the Fates ruled otherwise. A strong wind caught her during the night and she was speedily reduced to indistinguishable scrap. Despite catastrophe the inventor wrestled gamely with his project. The lessons taught by one disaster were taken to heart, and arrangements to prevent the recurrence thereof incorporated in the succeeding craft. Unfortunately, however, as soon as one defect was remedied another asserted itself. It was this persistent revelation of the unexpected which caused another period of indifference towards his invention. Probably nothing more would have been heard of the Zeppelin after this last accident had it not been for the intervention of the Prussian Government at the direct instigation of the Kaiser, who had now taken Count Zeppelin under his wing. A State lottery was inaugurated, the proceeds of which were handed over to the indefatigable inventor, together with an assurance that if he could keep aloft 24 hours without coming to earth in the meantime, and could cover 450 miles within this period, the Government would repay the whole of the money he had lavished upon his idea, and liquidate all the debts he had incurred in connection therewith. Another craft was built, larger than its predecessors, and equipped with two motors developing 170 horse-power. Upon completion it was submitted to several preliminary flights, which were so eminently successful that the inventor decided to make a trial trip under conditions closely analogous to those imposed for the Government test. On June 20th, 1908, at 8:26 a.m. the craft ascended and remained aloft for 12 hours, during which time it made an encouraging circular tour. Flushed with this success, the Count considered that the official award was within reach, and that all his previous disasters and misfortunes were on the eve of redemption. The crucial test was essayed on August 5th, 1908. Accompanied by twelve observers the vessel ascended and travelled without incident for eight hours. Then a slight mishap demanded attention, but was speedily repaired, and was ignored officially as being too trivial to influence the main issue. Victory appeared within measurable distance: the arduous toil of many patient years was about to be rewarded. The airship was within sight of home when it had to descend owing to the development of another motor fault. But as it approached the ground, Nature, as if infuriated at the conquest, rose up in rebellion. A sudden squall struck the unwieldy monster. Within a few moments it became unmanageable, and through some inscrutable cause, it caught fire, with the result that within a few moments it was reduced to a tangled mass of metallic framework. It was a catastrophe that would have completely vanquished many an inventor, but the Count was saved the gall of defeat. His flight, which was remarkable, inasmuch as he had covered 380 miles within 24 hours, including two unavoidable descents, struck the Teuton imagination. The seeds so carefully planted by the "Most High of Prussia" now bore fruit. The German nation sympathised with the indomitable inventor, appreciated his genius, and promptly poured forth a stream of subscriptions to enable him to build another vessel. The intimation that other Powers had approached the Count for the acquisition of his idea became known far and wide, together with the circumstance that he had unequivocally refused all offers. He was striving for the Fatherland, and his unselfish patriotism appealed to one and all. Such an attitude deserved hearty national appreciation, and the members of the great German public emptied their pockets to such a degree that within a few weeks a sum of L300,000 or $1,500,000 was voluntarily subscribed. All financial embarrassments and distresses were now completely removed from the Count's mind. He could forge ahead untrammelled by anxiety and worry. Another Zeppelin was built and it created a world's record. It remained aloft for 38 hours, during which time it covered 690 miles, and, although it came to grief upon alighting, by colliding with a tree, the final incident passed unnoticed. Germany was in advance of the world. It had an airship which could go anywhere, irrespective of climatic conditions, and in true Teuton perspective the craft was viewed from the military standpoint. Here was a means of obtaining the mastery of the air: a formidable engine of invasion and aerial attack had been perfected. Consequently the Grand Idea must be supported with unbounded enthusiasm. The Count was hailed by his august master as "The greatest German of the twentieth century," and in this appreciation the populace wholeheartedly concurred. Whether such a panegyric from such an auspicious quarter is praise indeed or the equivalent of complete condemnation, history alone will be able to judge, but when one reflects, at this moment, upon the achievements of this aircraft during the present conflagration, the unprejudiced will be rather inclined to hazard the opinion that Imperial Teuton praise is a synonym for damnation. Although the Zeppelin was accepted as a perfect machine it has never been possible to disperse the atmosphere of disaster with which it has been enveloped from the first. Vessel after vessel has gone up in smoke and flame: few craft of this type have enjoyed more than an evanescent existence; and each successive catastrophe has proved more terrible than its predecessor. But the Teutonic nation has been induced to pin its whole faith on this airship, notwithstanding that the more levelheaded engineers of other countries have always maintained the craft to be a "mechanical monstrosity" condemned from its design and principles of construction to disaster. Unshaken by this adverse criticism, Germany rests assured that by means of its Zeppelins it will achieve that universal supremacy which it is convinced is its Destiny. This blind child-like faith has been responsible for the establishment and development of the Zeppelin factories. At Friedrichshafen the facilities are adequate to produce two of these vessels per month, while another factory of a similar capacity has been established at Berlin. Unfortunately such big craft demand large docks to accommodate them, and in turn a large structure of this character constitutes an easy mark for hostile attack, as the raiding airmen of the Allies have proved very convincingly. But the Zeppelin must not be under-rated. Magnificent performances have been recorded by these vessels, such as the round 1,000 miles' trip in 1909, and several other equally brilliant feats since that date. It is quite true that each astounding achievement has been attended by an equally stupendous accident, but that is accepted as a mere incidental detail by the faithful Teutonic nation. Many vivid prophecies of the forthcoming flights by Zeppelin have been uttered, and it is quite probable that more than one will be fulfilled, but success will be attributable rather to accident than design. Although the Zeppelin is the main stake of the German people in matters pertaining to aerial conquest, other types of airships have not been ignored, as related in another chapter. They have been fostered upon a smaller but equally effective scale. The semi-rigid Parseval and Gross craft have met with whole-hearted support, since they have established their value as vessels of the air, which is tantamount to the acceptance of their military value. The Parseval is pronounced by experts to be the finest expression of aeronautical engineering so far as Teuton effort is concerned. Certainly it has placed many notable flights to its credit. The Gross airship is an equally serviceable craft, its lines of design and construction closely following those of the early French supple airships. There are several other craft which have become more or less recognised by the German nation as substantial units of war, such as the Ruthemberg, Siemens-Schukert, and so forth, all of which have proved their serviceability more or less conclusively. But in the somewhat constricted Teuton mind the Zeppelin and the Zeppelin only represents the ultima Thule of aerial navigation and the means for asserting the universal character of Pan-Germanism as well as "Kultur." CHAPTER IV. AIRSHIPS OF WAR So much has been said and written concerning the Zeppelin airship, particularly in its military aspect, that all other developments in this field have sunk into insignificance so far as the general public is concerned. The Zeppelin dirigible has come to be generally regarded as the one and only form of practical lighter-than-air type of aircraft. Moreover, the name has been driven home with such effect that it is regarded as the generic term for all German airships. These are grievous fallacies. The Zeppelin is merely one of a variety of types, even in Germany, although at the moment it probably ranks as the solitary survivor of the rigid system of construction. At one time, owing to the earnestness with which the advantages of this form of design were discussed, and in view of the fact that the Zeppelin certainly appeared to triumph when all other designs failed, Great Britain was tempted to embrace the rigid form of construction. The building of an immense vessel of this class was actively supported and it was aptly christened the "May-fly." Opponents of the movement tempered their emphatic condemnatory criticism so far as to remark that it MAY FLY, but as events proved it never did. The colossal craft broke its back before it ever ventured into the air, and this solitary experience proving so disastrous, the rigid form of construction was abandoned once and for all. The venture was not in vain; it brought home to the British authorities more convincingly than anything else that the Zeppelin was a mechanical monstrosity. The French never even contemplated the construction of such a craft at that time, estimating it at its true value, and the British failure certainly served to support French antagonism to the idea. Subsequently, however, an attempt at rigid construction was made in France with the "Spiess" airship, mainly as a concession to public clamour. Even in Germany itself the defects of the Zeppelin were recognised and a decided effort to eliminate them was made by Professor Schutte in co-operation with a manufacturer of Mannheim named Lanz. The joint product of their ambitions, the Schutte-Lanz, is declared to be superior to the Zeppelin, but so far it has failed to justify any of the claims of its designers. This vessel, which also favours the colossal, is likewise of the rigid type, but realising the inherent dangers accruing from the employment of metal for the framework, its constructors have used wood, reinforced and strengthened where necessary by metallic angle-iron, plates, and bracing; this utilisation of metal is, however, carried out very sparingly. The first vessel of this class was a huge failure, while subsequent craft have not proved much more successful. In fact, one of the largest German airships ever designed, L4, is, or rather was, a Schutte-Lanz, with a capacity of 918,000 cubic feet, but over 6,000 pounds lighter than a Zeppelin of almost similar dimensions. I say "was" since L4 is no more. The pride of its creators evinced a stronger preference for Davy Jones' Locker than its designed realm. Yet several craft of this type have been built and have been mistaken for Zeppelins owing to the similarity of the broad principles of design and their huge dimensions. In one vital respect they are decidedly inferior to their contemporary--they are not so speedy. The most successful of the German lighter-than-air machines are those known respectively as the semi rigid and non-rigid types, the best examples of which are the Gross and Parseval craft. Virtually they are Teutonic editions of the successful French craft of identical design by which they were anticipated. The Lebaudy is possibly the most famous of the French efforts in this direction. The gas-bag has an asymmetrical shape, and is pointed at both ends, although the prow is blunter or rounder than the stem. The gas-bag comprises a single chamber for the inflating agent, the distended shape of the envelope being sustained by means of an air-ballonet. By varying the contents of the latter through the agency of a pump the tension of the gas in the lifting envelope can be maintained, and the shape of the inflated balloon preserved under all conditions. Beneath the gas-bag is a long strengthened girder, and from this in turn the car is suspended. It is the introduction of this rigid girder which is responsible for the descriptive generic term of "semi-rigid." On the other hand the "non-rigid" type may be roughly described as a pisciform balloon fitted with propelling machinery, inasmuch as the car containing the driving machinery is suspended from the balloon in the manner of the car in the ordinary drifting vessel. So far as the French effort is concerned the Bayard-Clement type is the best example of the non-rigid system; it is represented in Germany by the Parseval class. The Gross airship has been definitely adopted as a military machine by the German authorities, and figures in the "M" class. The "M-IV" completed in 1913 is the largest of this type, and differs from its prototypes in that it carries two cars, each fitted with motors, whereas the earlier machines were equipped with a single gondola after the French pattern. This vessel measures 320 feet in length, has a maximum diameter of 44 1/2 feet, displaces 13 tons, and is fitted with motors developing 450 horse-power, which is sufficient to give it a speed of 47 miles per hour. This vessel represents a huge advance upon its predecessors of this design, inasmuch as the latter were about 245 feet in length by 36 1/4 feet in diameter, and displaced only six tons, while the single car was provided with a motor developing only 150 horse-power, the speed being 28 miles per hour. Thus it will be seen that a huge development has suddenly taken place, a result due no doubt to the co-operation of the well-known engineer Basenach. The "M-IV" is essentially an experiment and great secrecy has been maintained in regard to the trials which have been carried out therewith, the authorities merely vouchsafing the fact that the airship has proved completely successful in every respect; conclusive testimony of this is offered by the inclusion of the vessel in the active aerial fleet of Germany. But it is the Parseval which is regarded as the finest type of airship flying the German flag. This vessel is the product of slow evolution, for it is admitted to be a power-driven balloon. Even the broad lines of the latter are preserved, the shape being that of a cylinder with rounded ends. It is the direct outcome of the "Drachen-Balloon," perfected by Parseval and Siegsfeld, the captive balloon which is an indispensable part of the German military equipment. The complete success of the suspension system in this captive balloon prompted Parseval to continue his researches and experiments in regard to the application of power to the vessel, so as to induce it to move independently of the wind. The suspension system and the car are the outstanding features of the craft. It is non-rigid in the strictest interpretation of the term, although, owing to the incorporation of the steadying hollow "mattress" (as it is called by its inventor), the strength of the suspension system, and the substantial character of the car, it conveys an impression of great solidity. The thinnest rope, both manilla and steel, in the suspension system is as thick as a man's finger, while the car, measuring 30 feet in length by 6 feet in width, carried out in wood, is a striking example of the maximum of strength with the minimum of weight, being as steady and as solid as a boat's deck. The propellers are collapsible, although in the latest craft of this class they are semi-rigid. The mechanical equipment is also interesting. There are two propellers, and two motors, each nominally driving one propeller. But should one motor break down, or motives of economy, such as husbanding of fuel, render it advisable to run upon one engine, then the two propellers may be driven by either of the motors. The inventor has perfected an ingenious, simple, and highly efficient coupling device to attain this end, but to ensure that the propeller output is of the maximum efficiency in relation to the engine, the pitch of the propellers may be altered and even reversed while the engine is running. When one motor only is being used, the pitch is lowered until the propellers revolve at the speed which they would attain if both engines were in operation. This adjustment of the propeller pitch to the most economical engine revolutions is a distinctive characteristic, and contributes to the efficiency and reliability of the Parseval dirigible to a very pronounced degree. Steering in the vertical plane is also carried out upon distinctive lines. There are no planes for vertical steering, but movement is accomplished by tilting the craft and thus driving the gas from one end of the balloon to the other. This is effected by the manipulation of the air-ballonets, one of which is placed at the prow and stem of the gas bag respectively. If it is desired to descend the gas is driven from the forward to the after end of the envelope, merely by inflating the bow ballonet with air by means of a pump placed in the car. If ascent is required, the after-ballonet is inflated, thereby driving the gas to the forward end of the balloon, the buoyancy of which is thus increased. The outstanding feature of the "Drachen-Balloon" is incorporated in the airship. This is the automatic operation of the safety valve on the gas-bag directly by the air ballonets. If these ballonets empty owing to the pressure of the gas within the envelope, a rope system disposed within the balloon and connecting the ballonets and the gas-valve at the top is stretched taut, thereby opening the gas-valve. In this manner the gas-pressure becomes reduced until the ballonets are enabled to exercise their intended function. This is a safety precaution of inestimable value. The Parseval is probably the easiest dirigible to handle, inasmuch as it involves no more skill or knowledge than that required for an ordinary free balloon. Its movements in the vertical plane are not dissimilar to those of the aeroplane, inasmuch as ascent and descent are normally conducted in a "screwing" manner, the only exception being of course in abrupt descent caused by the ripping of the emergency-valve. On one occasion, it is stated, one of the latest machines of this type, when conducting experimental flights, absolutely refused to descend, producing infinite amusement both among the crowd and those on board. The development of the Parseval is directly attributable to the influence and intimate interest of the Kaiser, and undoubtedly this represents the wisest step he ever made in the realm of aeronautics. It certainly has enabled the German military machine to become possessed of a significant fleet of what may be described as a really efficient and reliable type of dirigible. The exact number of military Parsevals in commission is unknown, but there are several classes thereof, in the nature of aerial cruisers and vedettes. The largest and most powerful class are those known as the B type, measuring about 240 feet in length by 40 feet maximum diameter, of 223,000 cubic feet capacity, and fitted with two motorsand two propellers. This vessel carries about 10 passengers, can climb to a maximum height of approximately 8,500 feet, and is capable of remaining in the air for twenty hours upon a single fuel charge. While this is the largest and most serviceable type of Parseval designed for military duties, there is another, the A class, 200 feet in length with accommodation for six passengers in addition to the crew of three, which is capable of attaining a maximum altitude of 6,700 feet, and has an endurance capacity of 15 hours. This class also is fitted with twin propellers and motors. In addition there are the C and E classes, carrying from four to eight passengers, while the vedettes are represented by the D and F classes, which have a maximum altitude of 2,000 feet and can remain aloft for only five hours upon a single fuel charge. These smaller vessels, however, have the advantage of requiring only one or two men to handle them. The present military Parseval dirigible is made in one of these five standardised classes, experience having established their efficiency for the specified military services for which they are built. In point of speed they compare favourably with the latest types of Zeppelin, the speeds of the larger types ranging from 32 to 48 miles per hour with a motor effort of 360 to 400 horse-power. So far as the French airships of war are concerned, the fleet is somewhat heterogeneous, although the non-rigid type prevails. The French aerial navy is represented by the Bayard-Clement, Astra, Zodiac, and the Government-built machines. Although the rigid type never has met with favour in France, there is yet a solitary example of this system of construction--the Spiess, which is 460 feet in length by 47 feet in diameter and has a displacement of 20 tons. The semi-rigid craft are represented by the Lebaudy type, the largest of which measures 293 feet in length by 51 feet in diameter, and has a displacement of 10 tons. One may feel disposed to wonder why the French should be apparently backward in this form of aerial craft, but this may be explained by the fact that the era of experiment had not been concluded at the time war was declared, with the result that it has been somewhat difficult to determine which type would meet the military requirements of the country to the best advantage. Moreover, the French military authorities evinced a certain disposition to relegate the dirigible to a minor position, convinced that it had been superseded by the heavier-than-air machine. Taken on the whole, the French airship fleet is inferior to the German in point of speed, if not numerically, but this deficiency is more than counterbalanced by the skill and ability of the men manning their craft, who certainly are superior to their contemporaries in Germany, combined with the proved character of such craft as are in service. The same criticism may be said to apply to Great Britain. That country was backward in matters pertaining to the airship, because its experiments were carried out spasmodically while dependence was reposed somewhat too much upon foreign effort. The British airships are small and of low speed comparatively speaking. Here again it was the advance of the aeroplane which was responsible for the manifestation of a somewhat indifferent if not lethargic feeling towards the airship. Undoubtedly the experiments carried out in Great Britain were somewhat disappointing. The one and only attempt to out-Zeppelin the Zeppelin resulted in disaster to the craft before she took to the air, while the smaller craft carried out upon far less ambitious lines were not inspiritingly successful. Latterly the non-rigid system has been embraced exclusively, the craft being virtually mechanically driven balloons. They have proved efficient and reliable so far as they go, but it is the personal element in this instance also which has contributed so materially to any successes achieved with them. But although Great Britain and France apparently lagged behind the Germans, appreciable enterprise was manifested in another direction. The airship was not absolutely abandoned: vigilance was maintained for a superior type of craft. It was an instance of weighing the advantages against the disadvantages of the existing types and then evolving for a design which should possess the former without any of the latter. This end appears to be achieved with the Astra type of dirigible, the story of the development of which offers an interesting chapter in the annals of aeronautics. In all lighter-than-air machines the resistance to the air offered by the suspension ropes is considerable, and the reduction of this resistance has proved one of the most perplexing problems in the evolution of the dirigible. The air is broken up in such a manner by the ropes that it is converted into a brake or drag with the inevitable result that the speed undergoes a severe diminution. A full-rigged airship such as the Parseval, for instance, may present a picturesque appearance, but it is severely unscientific, inasmuch as if it were possible to eliminateor to reduce the air-resistance offered by the ropes, the speed efficiency might be raised by some sixty per cent and that without any augmentation of the propelling effort. As a matter of fact Zeppelin solved this vexatious problem unconsciously. In his monster craft the resistance to the air is reduced to a remarkable degree, which explains why these vessels, despite all their other defects are able to show such a turn of speed. It was this feature of the Zeppelin which induced Great Britain to build the May-fly and which likewise induced the French Government to stimulate dirigible design and construction among native manufacturers, at the same time, however, insisting that such craft should be equal at least in speed to the Zeppelins. The response to this invitation was the Spiess, which with its speed of 45 miles per hour ranked, until 1914, as one of the fastest dirigibles in the French service. In the meantime a Spanish engineer, Senor Torres, had been quietly working out a new idea. He realised the shortcomings of the prevailing types of airships some eleven years ago, and unostentatiously and painstakingly set out to eliminate them by the perfection of a new type of craft. He perfected his idea, which was certainly novel, and then sought the assistance of the Spanish Government. But his fatherland was not adapted to the prosecution of the project. He strove to induce the authorities to permit even a small vessel to be built, but in vain. He then approached the French Astra Company. His ambition was to build a vessel as large as the current Zeppelin, merely to emphasise the value of his improvement upon a sufficiently large scale, and to enable comparative data concerning the two designs to be obtained. But the bogey of expense at first proved insuperable. However, the French company, decided to give the invention a trial, and to this end a small "vedette" of about 53,000 cubic feet displacement was built. Although an unpretentious little vessel, it certainly served to emphasise the importance of the Torres idea. It was pitted against the "Colonel Renard," the finest ship at that time in the French aerial service, which had proved the fastest airship in commission, and which also was a product of the Astra Company. But this fine craft was completely outclassed by the puny Astra-Torres. The builders and the inventor were now additionally anxious to illustrate more emphatically the features of this design and to build a far larger vessel. The opportunity was offered by the British Government, which had been following the experiments with the small Astra-Torres in France. An order was given for a vessel of 282,500 cubic feet displacement; in this instance it was ranged against another formidable rival--the Parseval. But the latter also failed to hold its own against the Spanish invention, inasmuch as the Astra-Torres built for the British authorities exceeded a speed of 50 miles per hour in the official tests. This vessel is still doing valuable duty, being attached to the British air-service in France. The achievements of the British vessel were not lost upon the French Government, which forthwith placed an order for a huge vessel of 812,200 cubic feet capacity, equipped with motors developing 1,000 horse-power, which it was confidently expected would enable a speed of 60 miles per hour to be attained. Thus France would be able to meet the Germans upon fairly level terms, inasmuch as the speed of the latest Zeppelins does not exceed 60 miles per hour. So confident were the authorities that a second order for an even larger vessel was placed before the first large craft was completed. This latter vessel is larger than any Zeppelin yet built, seeing that it displaces 38 tons, and is fitted with motors developing 1,000 horse-power. It has recently been completed, and although the results of the trials, as well as the dimensions of the craft have not been published, it is well known that the speed has exceeded 60 miles per hour, so that France now possesses the speediest dirigible in the world. The Torres invention has been described as wonderful, scientifically perfect and extremely simple. The vessel belongs to the non-rigid class, but the whole of the suspension system is placed within the gas-bag, so that the air-resistance offered by ropes is virtually eliminated in its entirety, for the simple reason that practically no ropes are placed outside the envelope. The general principle of design may be gathered from the accompanying diagram. It is as if three sausage-shaped balloons were disposed pyramidally--two lying side by side with one super-imposed, with the bags connected at the points where the circular sections come into contact. Thus the external appearance of the envelope is decidedly unusual, comprising three symmetrical ridges. At the points where the three bags come into contact cloth bands are stretched across the arcs, thereby forming a cord. The suspension system is attached to the upper corners of the inverted triangle thus formed, and converges in straight lines through the gas space. The bracing terminates in collecting rings from which a short vertical cable extends downwards through a special accordion sleeve to pass through the lower wall of the envelope. These sleeves are of special design, the idea being to permit the gas to escape under pressure arising from expansion and at the same time to provide ample play for the cable which is necessary in a flexible airship. This cable emerges from the envelope only at the point or points where the car or cars is or are placed. In the British airship of this type there is only one car, but the larger French vessels are equipped with two cars placed tandem-wise. The vertical cable, after extending downwards a certain distance, is divided, one rope being attached to one, and the second to the other side of the car. The two-bladed propellers are disposed on either side of the car, in each of which a 500 horse-power motor is placed. The Astra-Torres type of dirigible may be said to represent the latest expression in airship design and construction. The invention has given complete satisfaction, and has proved strikingly successful. The French Government has completed arrangements for the acquisition of larger and more powerful vessels of this design, being now in the position to contest every step that is made by Germany in this field. The type has also been embraced by the Russian military authorities. The Astra-Torres airship has a rakish appearance, and although the lines of the gas-bag are admitted to increase frictional resistance, this is regarded as a minor defect, especially when the many advantages of the invention are taken into consideration. CHAPTER V. GERMANY'S AERIAL DREADNOUGHT FLEET Although Germany, as compared with France, was relatively slow to recognise the immense possibilities of aircraft, particularly dirigibles, in the military sense, once the Zeppelin had received the well-wishes of the Emperor William, Teuton activities were so pronounced as to enable the leeway to be made up within a very short while. While the Zeppelin commanded the greatest attention owing to the interesting co-operation of the German Emperor, the other types met with official and royal recognition and encouragement as already mentioned. France, which had held premier position in regard to the aerial fleet of dirigibles for so long, was completely out-classed, not only in dimensions but also in speed, as well as radius of action and strategical distribution of the aerial forces. The German nation forged ahead at a great pace and was able to establish a distinct supremacy, at least on paper. In the light of recent events it is apparent that the German military authorities realised that the dawn of "The Day" was approaching rapidly, and that it behoved them to be as fully prepared in the air as upon the land. It was immaterial that the Zeppelin was the synonym for disaster. By standardisation its cost could be reduced while construction could be expedited. Furthermore, when the matter was regarded in its broadest aspect, the fact was appreciated that forty Zeppelins could be built at the cost of one super-Dreadnought, so that adequate allowance could be made for accidents now and then, since a Zeppelin catastrophe, no matter how complete it may be, is regarded by the Teuton as a mere incident inseparable from progressive development. At the beginning of the year 1914 France relied upon being strengthened by a round dozen new dirigibles. Seven of these were to be of 20,000 cubic metres' capacity and possessed of a speed of 47 miles per hour. While the existing fleet was numerically strong, this strength was more apparent than real, for the simple reason that a large number of craft were in dry-dock undergoing repair or overhaul while many of the units were merely under test and could not be regarded therefore as in the effective fleet. True, there were a certain number of private craft which were liable to be commandeered when the occasion arose, but they could not be considered as decided acquisitions for the simple reason that many were purely experimental units. Aerial vessels, like their consorts upon the water, have been divided into distinctive classes. Thus there are the aerial cruisers comprising vessels exceeding 282,000 cubic feet in capacity; scouts which include those varying between 176,600 and 282,000 cubic feet capacity; and vedettes, which take in all the small or mosquito craft. At the end of 1913, France possessed only four of the first-named craft in actual commission and thus immediately available for war, these being the Adjutant Vincenot, Adjutant Reau, Dupuy de Lome, and the Transaerien. The first three are of 197,800 cubic feet. All, however, were privately owned. On the other hand, Germany had no fewer than ten huge vessels, ranging from 353,000 to 776,900 cubic feet capacity, three of which, the Victoria Luise, Suchard, and Hansa, though owned privately, were immediately available for war. Of these the largest was the Zeppelin naval vessel "L-1" 525 feet in length, by 50 feet diameter, of 776,900 cubic feet capacity, equipped with engines developing 510 horse-power, and with a speed of 51.8 miles per hour. At the end of 1913 the effective aerial fleet of Germany comprised twenty large craft, so far in advance of the French aerial cruisers as to be worthy of the name bestowed upon them--"Aerial Dreadnoughts." This merely represented the fleet available for immediate use and did not include the four gigantic Suchard-Schutte craft, each of 847,500 cubic feet, which were under construction, and which were being hurried forward to come into commission early in 1914. But the most interesting factor, apart from the possession of such a huge fleet of dirigible air-craft, was their distribution at strategical points throughout the Empire as if in readiness for the coming combat. They were literally dotted about the country. Adequate harbouring facilities had been provided at Konigsberg, Berlin, Posen, Breslau, Kiel, Hamburg, Wilhelmshaven, Dusseldorf, Cologne, Frankfort, Metz, Mannheim, Strasburg, and other places, with elaborate headquarters, of course, at Friedrichshafen upon Lake Constance. The Zeppelin workshops, harbouring facilities, and testing grounds at the latter point had undergone complete remodelling, while tools of the latest type had been provided to facilitate the rapid construction and overhaul of the monster Zeppelin dirigibles. Nothing had been left to chance; not an item was perfunctorily completed. The whole organisation was perfect, both in equipment and operation. Each of the above stations possessed provision for an aerial Dreadnought as well as one or more aerial cruisers, in addition to scouts or vedettes. Upon the outbreak of hostilities Germany's dirigible fleet was in a condition of complete preparedness, was better organised, and better equipped than that of any of her rivals. At the same time it constituted more of a paper than a fighting array for reasons which I will explain later. But there was another point which had escaped general observation. Standardisation of parts and the installation of the desired machinery had accomplished one greatly desired end--the construction of new craft had been accelerated. Before the war an interesting experiment was carried out to determine how speedily a vessel could be built. The result proved that a dirigible of the most powerful type could be completed within eight weeks and forthwith the various constructional establishments were brought into line so as to maintain this rate of building. The growth of the Zeppelin, although built upon disaster, has been amazing. The craft of 1906 had a capacity of 430,000 cubic feet and a speed of 36 miles per hour. In 1911 the creator of this type launched a huge craft having a capacity of 627,000 cubic feet. In the meantime speed had likewise been augmented by the use of more powerful motors until 52 miles an hour was attained. But this by no means represented the limit. The foregoing vessels had been designed for land service purely and simply, but now the German authorities demanded similar craft for naval use, possessed of high speed and greater radius of action. Count Zeppelin rose to the occasion, and on October 7th, 1912, launched at Friedrichshafen the monster craft "L-I," 525 feet in length, 50 feet in diameter, of 776,900 cubic feet capacity, a displacement of 22 tons and equipped with three sets of motors aggregating more than 500 horse-power, and capable of imparting a speed of 52 miles per hour. The appearance of this craft was hailed with intense delight by the German nation, while the naval department considered her to be a wonderful acquisition, especially after the searching reliability trial. In charge of Count Zeppelin and manned by a crew of 22 officers and men together with nearly three tons of fuel--the fuel capacity conveys some idea of her possible radius of action--she travelled from Friedrichshafen to Johannisthal in 32 hours. On this remarkable journey another point was established which was of far-reaching significance. The vessel was equipped with wireless telegraphy and therewith she kept in touch with the earth below throughout the journey, dropping and picking up wireless stations as she progressed with complete facility. This was a distinct achievement, inasmuch as the vessel having been constructed especially for naval operations she would be able to keep in touch with the warships below, guiding them unerringly during their movement. The cross-country trip having proved so completely successful the authorities were induced to believe that travelling over water would be equally satisfactory. Accordingly the "L-I" was dispatched to the island of Heligoland, the intention being to participate in naval manoeuvres in order to provide some reliable data as to the value of these craft operating in conjunction with warships. But in these tests German ambition and pride received a check. The huge Zeppelin was manoeuvring over the North Sea within easy reach of Heligoland, when she was caught by one of those sudden storms peculiar to that stretch of salt water. In a moment she was stricken helpless; her motive power was overwhelmed by the blind forces of Nature. The wind caught her as it would a soap-bubble and hurled her into the sea, precipitating the most disastrous calamity in the annals of aeronautics, since not only was the ship lost, but fifteen of her crew of 22 officers and men were drowned. The catastrophe created consternation in German aeronautical circles. A searching inquiry was held to explain the disaster, but as usual it failed to yield much material information. It is a curious circumstance, but every successive Zeppelin disaster, and their number is legion, has been attributable to a new cause. In this instance the accident was additionally disturbing, inasmuch as the ship had been flying across country continuously for about twelve months and had covered more miles than any preceding craft of her type. No scientific explanation for the disaster was forthcoming, but the commander of the vessel, who sank with his ship, had previously ventured his personal opinion that the vessel was over-loaded to meet the calls of ambition, was by no means seaworthy, and that sooner or later she would be caught by a heavy broadside wind and rendered helpless, or that she would make a headlong dive to destruction. It is a significant fact that he never had any faith in the airship, at least for sea duty, though in response to official command he carried out his duties faithfully and with a blind resignation to Fate. Meantime, owing to the success of the "L-I" in cross-country operations, another and more powerful craft, the "L-II" had been taken in hand, and this was constructed also for naval use. While shorter than her consort, being only 487 feet over all, this vessel had a greater beam--55 feet. This latter increase was decided because it was conceded to be an easier matter to provide for greater beam than enhanced length in the existing air-ship harbours. The "L-II" displaced 27 tons--five tons in excess of her predecessor. In this vessel many innovations were introduced, such as the provision of the passage-way connecting the cars within the hull, instead of outside the latter as had hitherto been the practice, while the three cars were placed more closely together than formerly. The motors were of an improved type, giving an aggregate output of 900 horse-power, and were divided into four separate units, housed in two engine-rooms, the front car being a replica in every detail of the navigating bridge of a warship. This vessel was regarded as a distinct improvement upon the "L-I," although the latter could boast some great achievements. But her glory was short-lived. In the course of the Government trials, while some 900 feet aloft, the huge vessel suddenly exploded and was burned in the air, a mass of broken and twisted metal-work falling to the ground. Of the 28 officers and men, including members of the Admiralty Board who were conducting the official trials, all but one were killed outright, and the solitary exception was so terribly burned as to survive the fall for only a few hours. The accident was remarkable and demonstrated very convincingly that although Count Zeppelin apparently had made huge strides in aerial navigation through the passage of years, yet in reality he had made no progress at all. He committed the identical error that characterised the effort of Severo Pax ten years previously, and the disaster was directly attributable to the self-same cause as that which overwhelmed the Severo airship. The gas, escaping from the balloons housed in the hull, collected in the confined passage-way communicating with the cars, came into contact with a naked light, possibly the exhaust from the motors, and instantly detonated with terrific force, blowing the airship to fragments and setting fire to all the inflammable materials. In this airship Zeppelin committed an unpardonable blunder. He had ignored the factor of "internal safety," and had deliberately flown in the face of the official rule which had been laid down in France after the Severo disaster, which absolutely forbade the inclusion of such confined spaces as Zeppelin had incorporated. This catastrophe coming so closely as it did upon the preceding disaster to the pride of the German aerial fleet somewhat shook public confidence in these craft, while aeronautical authorities of other countries described the Zeppelin more vehemently than ever as a "mechanical monstrosity" and a "scientific curiosity." The Zeppelin has come to be feared in a general manner, but this result is due rather to stories sedulously circulated, and which may be easily traced to Teutonic sources. Very few data of a reliable character have been allowed to filter through official circles. We have been told somewhat verbosely of what it can accomplish and of its high degree of efficiency and speed. But can credence be placed in these statements? When Zeppelin IV made its unexpected descent at Luneville, and was promptly seized by the French authorities, the German War office evinced distinct signs of uneasiness. The reason was speedily forth coming. The captain of the craft which had been captured forgot to destroy his log and other records of data concerning the vessel which had been scientifically collected during the journey. All this information fell into the hands of the French military department, and it proved a wondrous revelation. It enabled the French to value the Zeppelin at its true worth, which was by no means comparable to the estimate based on reports skilfully circulated for the benefit of the world at large. Recently the French military department permitted the results of their expert official examination to be made public. From close investigation of the log-book and the diagrams which had been prepared, it was found that the maximum speed attained by Zeppelin IV during this momentous flight was only 45 miles per hour! It was ascertained, moreover, that the load was 10,560 pounds, and the ascensional effort 45,100 pounds. The fuel consumption had averaged 297 pounds per hour, while the fuel tanks carried sufficient for a flight of about seven hours. The airship had attained a maximum height of about 6,230 feet, to reach which 6,600 pounds of ballast had to be discarded. Moreover, it was proved that a Zeppelin, if travelling under military conditions with full armament and ammunition aboard, could carry sufficient fuel for only ten hours at the utmost, during which, if the slightest head-wind prevailed, it could not cover more than 340 miles on the one fuel charge. This information has certainly proved a revelation and has contributed to the indifference with which the Parisians regard a Zeppelin raid. At the outbreak of war the Zeppelin station nearest to Paris was at Metz, but to make the raid from that point the airship was forced to cover a round 500 miles. It is scarcely to be supposed that perfectly calm weather would prevail during the whole period of the flight, so that a raid would be attended by considerable risk. That this handicap was recognised in German military circles is borne out by the fact that a temporary Zeppelin hangar was established at a point considerably nearer the French capital, for the purpose of enabling a raid to be carried out with a greater possibility of success. The capture of Zeppelin IV revealed another important fact. The critical flying height of the airship is between 3,300 and 4,000 feet. To attempt a raid at such an altitude would be to court certain disaster, inasmuch as the vessel would have to run the gauntlet of the whole of the French artillery, which it is admitted has a maximum range exceeding the flying altitude of the Zeppelin. That the above calculation is within reason is supported by the statements of Count Zeppelin himself, who has declared that his airships are useless at a height exceeding 5,000 feet. Confirmatory evidence upon this point is offered by the raid upon the British East Coast towns, when it is stated that the aircraft were manoeuvring at a height not exceeding 2,000 feet. CHAPTER VI. THE MILITARY VALUE OF GERMANY'S AERIAL FLEET Although the Zeppelin undoubtedly has been over-rated by the forces to which it is attached, at the same time it must not be under-estimated by its detractors. Larger and more powerful vessels of this type have been, and still are being, constructed, culminating, so far as is known, in the "L-5," which is stated to have a capacity of about 1,000,000 cubic feet, and to possess an average speed of 65 miles per hour. While it is generally maintained that the Zeppelins will prove formidable in attack, greater reliance is being placed upon the demoralising or terrifying effect which they are able to exercise. Owing to the fact that from 3 to 5 tons of fuel--say 900 to 1,500 gallons of gasoline or petrol--can be carried aboard, giving them a wide radius of action, it is doubtful whether they could travel from Cologne to London and back upon a single fuel charge, since such a raid would entail a journey of about 600 miles. The latest types of this craft are said to possess a high ascensional speed, which offers a distinct protection against aeroplane attack. According to such official information as has been vouchsafed, a Zeppelin, when hard pressed, is able to rise vertically 3,500 feet in about three minutes. This is far in excess of the ascensional speed of even the speediest aeroplane, of course, the penalty for such a factor has to be paid: the loss of gas is appreciable and may lead to the craft's ultimate undoing. At the same time, however, it is able to maintain the superior position as compared with the aeroplane for a considerable period: the upper reaches of the air are its sanctuary. Nor must the nocturnal activities of the Zeppelin be overlooked. So far as night operations by these vessels are concerned, little has leaked out, so that the possibilities of the airship in this direction are still somewhat hypothetical. The fact remains, however, that it is night movements which perhaps are the most to be dreaded by the enemy. According to official German sources of information the latest types of Zeppelins are engined by "noiseless" motors. There is nothing remarkable in this feature, since the modern motor-car virtually answers to this description, although in this instance quietness is obtained for the most part by recourse to the sleeve-valve engine. Still, the ordinary Otto-cycle internal combustion engine can be rendered almost silent by the utilisation of adequate muffling devices, which, in the Zeppelin, are more possible of incorporation than in the aeroplane, because the extra weight imposed by this acquisition is a minor consideration in comparison with the lifting power of the vessel. Night operations, however, have not proved eminently successful. The very darkness which protects the aerial prowler also serves a similar purpose in connection with its prey. But aerial operations under the cover of darkness are guided not so much by the glare of lights from below as betrayal by sound. The difference between villages and cities may be distinguished from aloft, say at 1,500 to 3,000 feet, by the hum which life and movement emit, and this is the best guide to the aerial scout or battleship. The German authorities have made a special study of this peculiar problem, and have conducted innumerable tests upon the darkest nights, when even the sheen of the moon has been unavailable, for the express purpose of training the aerial navigators to discover their position from the different sounds reaching them from below. In other words, the corsair in the skies depends more upon compass and sound than upon compass and vision when operating after dark. The searchlights with which the Zeppelins are equipped are provided merely for illuminating a supposed position. They are not brought into service until the navigator concludes that he has arrived above the desired point: the ray of light which is then projected is merely to assist the crew in the discharge of the missiles of destruction. The Zeppelin, however, owing to its speed, both in the horizontal and vertical planes, is essentially a unit for daylight operations. The other airships which Germany possesses, and which for the most part are of the non-rigid type, are condemned to daylight operations from the character of their design. Owing to their low speeds they may be dismissed as impossible aerial vessels for hazardous work and are not regarded by the German authorities as all-round airships of war. Craft of the air are judged in Germany from the one standard only. This may be a Teutonic failing, but it is quite in keeping with the Teutonic spirit of militarism. Commercialism is a secondary factor. To the German Emperor an airship is much what a new manufacturing process or machine is to the American. Whereas the latter asks, "How much will it save me on the dollar?" to the War Lord of Germany--and an airship notwithstanding its other recommendatory features is judged solely from this standpoint--the question is "What are its military qualifications?" When the semi-rigid airship "V-I" was brought before the notice of the German military department the pressing point concerning its military recommendations arose at once. The inventor had foreseen this issue and was optimistic. Thereupon the authorities asked if the inventor were prepared to justify his claims. The retort was positive. Forthwith the Junkers decided to submit it to the test. This ship is of quite a distinctive type. It is an aerial cruiser, and the inventor claims that it combines all the essential qualifications of the Zeppelin and of the competitors of the latter, in addition to the advantage of being capable of dissection, transportation in parts, and rapid re-erection at any desired spot. The length of the vessel is about 270 feet; maximum diameter approximately 42 feet, and capacity about 300,000 cubic feet. The outstanding feature is a rigid keel-frame forming a covered passage way below the envelope or gas-bag, combined with easy access to all parts of the craft while under way, together with an artificial stiffening which dispenses with the necessity of attaching any additional cars. The frame is so designed that the load, as well as the ballast and fuel tanks, may be distributed as desired, and at the same time it ensures an advantageous disposition of the steering mechanism, far removed from the centre of rotation at the stern, without any overloading of the latter. The lifting part of the airship comprises a single gas bag fitted with two ballonets provided to ensure the requisite gas-tension in the main envelope, while at the same time permitting, in times of emergency, a rapid change of altitude. Self-contained blowers contribute to the preservation of the shape of the envelope, the blowers and the ballonets being under the control of the pilot. Planes resembling Venetian blinds facilitate vertical steering, while the suspension of the keel is carried out in such a manner as to secure uniformity of weight upon the gas bag. The propelling power comprises two sets of internal combustion engines, each developing 130 horse-power, the transmission being through rubber belting. The propellers, built of wood, make 350 revolutions per minute, and are set as closely as possible to the centre of resistance. But the most salient characteristic of this machine is its portability. It can be dismantled and transported by wagons to any desired spot, the suspension frame being constructed in units, each of which is sufficiently small to be accommodated in an ordinary vehicle. Upon arrival the parts may be put together speedily and easily. The authorities submitted the airship to exacting trials and were so impressed by its characteristics and the claims of the inventor that undoubtedly it will be brought into service during the present crisis. At the same time the whole faith of the German military staff so far as airship operations are concerned, is pinned to the Zeppelin. Notwithstanding its many drawbacks it is the vessel which will be used for the invasion of Great Britain. Even the harbour question, which is admitted to be somewhat acute, has been solved to a certain degree. At strategical points permanent harbours or airship sheds have been established. Seeing that the airships demand considerable skill in docking and undocking, and that it is impossible to achieve these operations against the wind, swinging sheds have been adopted. On water the practice is to anchor a floating harbour at one end, leaving the structure to swing round with the wind. But on dry land such a dock is impossible. Accordingly turntable sheds have been adopted. The shed is mounted upon a double turn-table, there being two circular tracks the one near the centre of the shed and the other towards its extremities. The shed is mounted upon a centre pivot and wheels engaged with these inner and outer tracks. In this manner the shed may be swung round to the most favourable point of the compass according to the wind. In the field, however, such practices are impossible, and the issue in this connection has been overcome by recourse to what may be termed portable harbours. They resemble the tents of peripatetic circuses and travelling exhibitions. There is a network of vertical steel members which may be set with facility and speed and which are stayed by means of wire guys. At the top of the outer vertical posts pulleys are provided whereby the outer skin or canvas forming the walls may be hauled into position, while at the apex of the roof further pulleys ensure the proper placing of the roofing. The airship is able to enter or leave from either end according to conditions. The material is fireproofed as a precautionary measure, but at the same time the modern aerial bomb is able to penetrate the roofing without any difficulty and to explode against the airship anchored within. The one great objection to the Zeppelin harbour is the huge target it offers to hostile attack, which, in the event of a vessel being moored within, is inevitably serious. Thus, for instance, upon the occasion of the air raids conducted by Lieutenant Collet and of Squadron Commander Briggs and his colleagues at Dusseldorf and Friedrichshafen respectively, little difficulty was experienced in destroying the airships riding at anchor. The target offered by the shed is so extensive that it would be scarcely possible for a flying enemy to miss it. A bomb dropped from a reasonable height, say 500 feet, would be almost certain to strike some part of the building, and a Zeppelin is an easy vessel to destroy. The firing of one balloon is sufficient to detonate the whole, for the simple reason that hydrogen gas is continuously oozing through the bags in which it is contained. According to a recent statement the Germans are said to be utilising an inert or non-inflammable gas, equal in lifting power to hydrogen, for the inflation of military craft, but scientific thought does not entertain this statement with any degree of seriousness. No gas as light as hydrogen and non-explosive is known to commerce. Will Germany invade Great Britain by air? This is the absorbing topic of the moment--one which has created intense interest and a certain feeling of alarm among the timorous. Although sporadic raids are considered to be possible and likely to be carried out with a varying measure of success--such as that made upon the British East Coast--eminent authorities ridicule an invasion in force. The risk would be enormous, although there is no doubt that Germany, which has always maintained that an invasion of this character will be made, will be compelled to essay such a task, in order to satisfy public opinion, and to justify official statements. It is a moot point, however, whether the invaders ever will succeed in making good their escape, unless Nature proves exceptionally kind. The situation is best summed up in the unbiassed report of General George P. Scriven, Chief Signal officer of the United States Army to the U.S. Secretary of War. In this report, which deals exhaustively with the history, construction and achievements of airships, such an invasion is described as fantastic and impracticable. Writing on November 10th, 1914, the officer declares that "he is not prepared to recommend the American Army to take up seriously the question of constructing dirigibles, as they are not worth their cost as offensive machines, while for reconnaissance or defence they are of far less value than aeroplanes." In his words, "Dirigibles are seemingly useless in defence against the aeroplane or gun-fire." In order to be able to make an invasion in force upon Great Britain's cities extremely favourable weather must prevail, and the treacherous nature of the weather conditions of the North Sea are known fully well both to British and Teuton navigators. Seeing that the majority of the Zeppelin pilots are drawn from the Navy and mercantile marine, and thus are conversant with the peculiarities and characteristics of this stretch of salt water, it is only logical to suppose that their knowledge will exert a powerful influence in any such decision, the recommendations of the meteorological savants not withstanding. When the Zeppelin pride of the German Navy "L-1" was hurled to destruction by a typical North Sea squall, Captain Blew of the Victoria Luise, a Zeppelin with many great achievements to her credit, whose navigator was formerly in the Navy, and thus is familiar with the whole issue, explained that this atmospheric liveliness of the North Sea prevails for the most part in the latitude of Norway, but that it frequently extends as far south as the gate of the Channel. He related furthermore that the rain squalls are of tropical violence, while the vertical thrusts of air are such that no dirigible as yet constructed could ever hope to live in them. Under such conditions, he continued, the gas is certain to cool intensely, and the hull must then become waterlogged, not to mention the downward thrust of the rain. Under such conditions buoyancy must be imperilled to such a degree as to demand the jettisoning of every piece of ballast, fuel and other removable weight, including even the steadying and vertical planes. When this has been done, he pointed out, nothing is left with which to combat the upward vertical thrusts of the air. To attempt to run before the wind is to court positive disaster, as the wind is certain to gain the mastery. Once the airship loses steering way and is rendered uncontrollable it becomes the sport of the forces of Nature, with the result that destruction is merely a matter of minutes, or even seconds. Every navigator who knows the North Sea will support these conclusions. Squalls and blizzards in winter, and thunderstorms in summer, rise with startling suddenness and rage with terrific destructive fury. Such conditions must react against the attempt of an aerial invasion in force, unless it be made in the character of the last throw by a desperate gambler, with good fortune favouring the dash to a certain degree. But lesser and more insignificant Zeppelin raids are likely to be somewhat frequent, and to be made at every favourable climatic opportunity. CHAPTER VII. AEROPLANES OF WAR Owing to the fertility of inventors and the resultant multiplicity of designs it is impossible to describe every type of heavier-than-air machine which has been submitted to the exacting requirements of military duty. The variety is infinite and the salient fact has already been established that many of the models which have proved reliable and efficient under normal conditions are unsuited to military operations. The early days of the war enabled those of doubtful value to be eliminated, the result being that those machines which are now in use represent the survival of the fittest. Experience has furthermore emphasised the necessity of reducing the number of types to the absolute minimum. This weeding-out process is being continued and there is no doubt that by the time the war is concluded the number of approved types of aeroplanes of military value will have been reduced to a score or less. The inconveniences and disadvantages arising from the utilisation of a wide variety of different types are manifold, the greatest being the necessity of carrying a varied assortment of spare parts, and confusion in the repair and overhauling shops. The methodical Teuton was the first to grasp the significance of these drawbacks; he has accordingly carried standardisation to a high degree of efficiency, as is shown in another chapter. At a later date France appreciated the wisdom of the German practice, and within a short time after the outbreak of hostilities promptly ruled out certain types of machines which were regarded as unsuitable. In this instance the process of elimination created considerable surprise, inasmuch as it involved an embargo on the use of certain machines, which under peace conditions had achieved an international reputation, and were held to represent the finest expression of aeronautical science in France as far as aeroplane developments are concerned. Possibly the German machine which is most familiar, by name, to the general public is the Taube, or, as it is sometimes called, the Etrich monoplane, from the circumstance that it was evolved by the Austrian engineer Igo Etrich in collaboration with his colleague Wels. These two experimenters embarked on the study of dynamic flight contemporaneously with Maxim, Langley, Kress, and many other well-known pioneers, but it was not until 1908 that their first practical machine was completed. Its success was instantaneous, many notable flights being placed to its credit, while some idea of the perfection of its design may be gathered from the fact that the machine of to-day is substantially identical with that used seven years ago, the alterations which have been effected meanwhile being merely modifications in minor details. The design of this machine follows very closely the lines of a bird in flight--hence its colloquial description, "Taube," or "dove." Indeed the analogy to the bird is so close that the ribs of the frame resemble the feathers of a bird. The supporting plane is shaped in the manner of a bird's distended wing, and is tipped up at the rear ends to ensure stability. The tail also resembles that of a bird very closely. This aeroplane, especially the latest type, is very speedy, and it has proved extremely reliable. It is very sharp in turning and extremely sensitive to its rudder, which renders it a first-class craft for reconnoitring duty. The latest machines are fitted with motors developing from 120 to 150 horse-power. The "Taube" commanded attention in Germany for the reason that it indicated the first departure from the adherence to the French designs which up to that time had been followed somewhat slavishly, owing to the absence of native initiative. The individuality of character revealed in the "Taube" appealed to the German instinct, with the result that the machine achieved a greater reputation than might have been the case had it been pitted against other types of essentially Teutonic origin. The Taube was subsequently tested both in France and Great Britain, but failed to raise an equal degree of enthusiasm, owing to the manifestation of certain defects which marred its utility. This practical experience tended to prove that the Taube, like the Zeppelin, possessed a local reputation somewhat of the paper type. The Germans, however, were by no means disappointed by such adverse criticism, but promptly set to work to eliminate defects with a view to securing an all-round improvement. The most successful of these endeavours is represented in the Taube-Rumpler aeroplane, which may be described as an improved edition of Etrich's original idea. As a matter of fact the modifications were of so slight, though important, a character that many machines generically described as Taubes are in reality Rumplers, but the difference is beyond detection by the ordinary and unpractised observer. In the Rumpler machine the wings, like those of the Taube, assume broadly the form and shape of those of the pigeon or dove in flight. The early Rumpler machines suffered from sluggish control, but in the later types this defect has been overcome. In the early models the wings were flexible, but in the present craft they are rigid, although fitted with tips or ailerons. The supporting truss beneath the wings, which was such an outstanding feature of its prototype, has been dispensed with, the usual I-beam longitudinals being used in its stead. The latest machines fitted with 100-120 horse-power Mercedes motors have a fine turn of speed, possess an enhanced ascensional effort, and are far simpler to control. Other German machines which are used in the military service are the Gotha and the Albatross. The former is a monoplane, and here again the influence of Etrich upon German aeroplane developments is strongly manifested, the shape of the bird's wing being retained. In the Gotha the truss which Etrich introduced is a prominent characteristic. The Albatross is a biplane, but this craft has proved to be somewhat slow and may be said to be confined to what might be described as the heavier aerial military duties, where great endurance and reliability are essential. As the war proceeds, doubtless Teuton ingenuity will be responsible for the appearance of new types, as well as certain modifications in the detail construction of the existing machines, but there is every indication that the broad lines of Etrich's conception will be retained in all monoplanes. There is one point in which Germany has excelled. Wood is not employed in the construction of these heavier-than-air craft. Steel and the lighter tough alloys are exclusively used. In this way the minimum of weight consistent with the maximum of strength policy is carried out. Moreover the manufacture of component parts is facilitated and accelerated to a remarkable degree by the use of metal, while the tasks of fitting and repairing are notably expedited by the practice of standardisation. Germany is also manifesting commendable enterprise in the perfection of light powerful motors for these dynamic machines. The latest types of explosion-motors range from 100 to 150 horse-power; the advantages of these are obvious. Upon the outbreak of hostilities the French possessed an enormous number and variety of aeroplanes and this aerial fleet had been brought to a high standard of organisation. The aerial fleet is sub-divided into squadrons called "escadrilles," each of which comprises six machines and pilots. These units are kept up to strength, wastage being made up from reserves, so as to maintain the requisite homogeneity. But ere the war had been in progress many weeks an official order was issued forbidding the employment of the Bleriot, Deperdussin, Nieuport, and R.E.P. monoplanes. Those which received official approval included the Caudron, Henry, and Maurice Farman, Morane-Saulnier, and Voisin machines. This drastic order came somewhat as a thunderbolt, and the reason for the decree has not been satisfactorily revealed. Suffice to say that in one stroke the efficiency and numerical strength of the French aerial navy were reduced very appreciably. For instance, it is stated that there were thirty escadrilles of Bleriot monoplanes together with pilots at the front, in addition to thirty mixed escadrilles of the other prohibited types with their fliers. Moreover a round 33 escadrilles of all the various types were in reserve. The effect of the military order was to reduce the effective strength by no fewer than 558 aeroplanes. Seeing that the French aerial force was placed at a great disadvantage numerically by this action, there seems to be ample justification for the hostile criticism which the decree of prohibition aroused in certain circles, especially when it is remembered that there was not an equal number of the accepted machines available to take the place of those which had been ruled out of court. One effect of this decree was to throw some 400 expert aviators upon the waiting list for the simple reason that machines were unavailable. Some of the best aviation skill and knowledge which France possesses were affected by the order. It is stated that accomplished aviators, such as Vedrines, were unable to obtain machines. It will be seen that the ultimate effect of the French military decree was to reduce the number of types to about four, each of which was allotted a specific duty. But whereas three different bi-planes are on the approved list there is only one monoplane--the Morane-Saulaier. This machine, however, has a great turn of speed, and it is also able to climb at a very fast pace. In these respects it is superior to the crack craft of Germany, so that time after time the latter have refused battle in the skies, and have hurried back to their lines. The Morane-Saulnier is the French mosquito craft of the air and like the insect, it is avowedly aggressive. In fact, its duties are confined to the work of chasing and bringing down the enemy, for which work its high manoeuvring capacity is excellently adapted. Its aggressive armament comprises a mitrailleuse. Unfortunately, however, the factory responsible for the production of this machine is at present handicapped by the limitations of its manufacturing plant, which when pushed to the utmost extent cannot turn out more than about ten machines per week. No doubt this deficiency will be remedied as the war proceeds by extension of the works or by allotting orders to other establishments, but at the time of the decree the manufacturing capacity was scarcely sufficient to make good the wastage, which was somewhat heavy. As far as biplanes are concerned the Caudron is the fastest in flight and is likewise extremely quick in manoeuvring. It is a very small machine and is extremely light, but the fact that it can climb at the rate of over 330 feet per minute is a distinct advantage in its favour. It supplements the Morane-Saulnier monoplane in the specific duty of the latter, while it is also employed for discovering the enemy's artillery and communicating the range of the latter to the French and British artillery. In this latter work it has played a very prominent part and to it is due in no small measure that deadly accuracy of the artillery of the Allies which has now become so famous. This applies especially to those tactics, where the field artillery dashes up to a position, discharges a number of rounds in rapid succession, or indulges in rafale firing, and then limbering up, rushes away before the enemy can reply. As is well known the Farman biplanes possess high endurance qualities. They can remain aloft for many hours at a stretch and are remarkably reliable. Owing to these qualities they are utilised for prolonged and searching reconnoitring duties such as strategical reconnaissances as distinct from the hurried and tactical reconnaissances carried out by fleeter machines. While they are not so speedy as the monoplanes of the German military establishment, endurance in this instance is preferable to pace. A thorough survey of the enemy's position over the whole of his military zone, which stretches back for a distance of 30 miles or so from the outer line of trenches, is of incalculable value to a commander who is contemplating any decisive movement or who is somewhat in doubt as to the precise character of his antagonist's tactics. The French aerial fleet has been particularly active in its work of raiding hostile positions and submitting them to a fusillade of bombs from the clouds. The machine which is allotted this specific task is the Voisin biplane. This is due to the fact that this machine is able to carry a great weight. It was speedily discovered that in bomb-raids it is essential for an aeroplane to be able to carry a somewhat large supply of missiles, owing to the high percentage of misses which attends these operations. A raid by a machine capable of carrying only, say, half-a-dozen projectiles, is virtually a waste of fuel, and the endurance limitations of the fast machines reacts against their profitable use in this work. On the other hand, the fact that the Voisin machine is able to carry a large supply of bombs renders it an ideal craft for this purpose; hence the official decision to confine it to this work. So far as the British efforts in aerial work are concerned there is no such display of rigid selection as characterises the practice of the French and German military authorities. Britain's position in the air has been extensively due to private enterprise, and this is still being encouraged. Moreover at the beginning of the war Britain was numerically far inferior both to her antagonist and to her ally. Consequently it was a wise move to encourage the private manufacture of machines which had already established their value. The consequence is that a variety of machines figure in the British aerial navy. Private initiative is excellently seconded by the Government manufacturing aeroplane factory, while the training of pilots is likewise being carried out upon a comprehensive scale. British manufacture may be divided into two broad classes--the production of aeroplanes and of waterplanes respectively. Although there is a diversity of types there is a conspicuous homogeneity for the most part, as was evidenced by the British raid carried out on February 11-12, when a fleet of 34 machines raided the various German military centres established along the coast of Flanders. Considerable secrecy has been displayed by the British Government concerning the types of machines that are being utilised, although ample evidence exists from the producing activity of the various establishments that all available types which have demonstrated their reliability and efficiency are being turned to useful purpose. The Avro and Sopwith warplanes with their very high speeds have proved remarkably successful. So far as manufacturing is concerned the Royal Aerial Factory may be said to constitute the back bone of the British aerial fleet. This factory fulfils various purposes. It is not only engaged in the manufacture of machines, and the development of aeroplanes for specific duties, but also carries out the inspection and testing of machines built by private firms. Every machine is submitted to an exacting test before it is passed into the service. Three broad types of Government machines are manufactured at this establishment. There is that designed essentially for scouting operations, in which speed is the all-important factor and which is of the tractor type. Another is the "Reconnoitring" machine known officially as the "R.E." to-day, but formerly as the "B.E" (Bleriot-Experimental), a considerable number of which are in commission. This machine is also of the tractor type, carrying a pilot and an observer, and has a maximum speed of 40-50 miles per hour. If required it can further be fitted with an automatic gun for defence and attack. The third craft is essentially a fighting machine. Owing to the introduction of the machine-gun which is fixed in the prow, with the marksman immediately behind it, the screw is placed at the rear. The pilot has his seat behind the gunner. The outstanding feature of these machines is the high factor of safety, which attribute has astonished some of the foremost aviation experts in the world. Great Britain lagged behind her Continental rivals in the development of the Fourth Arm, especially in matters pertaining to motive power. For some time reliance was placed upon foreign light highspeed explosion motors, but private enterprise was encouraged, with the result that British Motors comparing favourably in every respect with the best productions upon the Continent are now available. Development is still proceeding, and there is every evidence that in the near future entire reliance will be placed upon the native motor. Undoubtedly, as the war progresses, many valuable lessons will be learned which will exercise an important bearing upon the design and construction of warplanes. The ordeals to which the machines are submitted in military duties are far more severe than any imposed by the conditions of commerce. Accordingly there is every indication that the conflict upon the Continent will represent a distinctive epoch in aeroplane design and construction. Many problems still await solution, such as the capacity to hover over a position, and it is quite possible that these complex and baffling questions will be settled definitely as the result of operations in the field. The aeroplane has reached a certain stage of evolution: further progress is virtually impossible unless something revolutionary is revealed, perfected, and brought to the practical stage. CHAPTER VIII. SCOUTING FROM THE SKIES From the moment when human flight was lifted from the rut of experiment to the field of practical application, many theories, interesting and illuminating, concerning the utility of the Fourth Arm as a military unit were advanced. The general consensus of expert opinion was that the flying machine would be useful to glean information concerning the movements of an enemy, rather than as a weapon of offence. The war is substantiating this argument very completely. Although bomb-dropping is practised somewhat extensively, the results achieved are rather moral than material in their effects. Here and there startling successes have been recorded especially upon the British side, but these triumphs are outnumbered by the failures in this direction, and merely serve to emphasise the views of the theorists. The argument was also advanced that, in this particular work, the aeroplane would prove more valuable than the dirigible, but actual campaigning has proved conclusively that the dirigible and the heavier-than-air machines have their respective fields of utility in the capacity of scouts. In fact in the very earliest days of the war, the British airships, though small and slow in movement, proved more serviceable for this duty than their dynamic consorts. This result was probably due to the fact that military strategy and tactics were somewhat nonplussed by the appearance of this new factor. At the time it was an entirely unknown quantity. It is true that aircraft had been employed in the Balkan and the Italo-Ottoman campaigns, but upon such a limited scale as to afford no comprehensive idea of their military value and possibilities. The belligerents, therefore, were caught somewhat at a disadvantage, and an appreciable period of time elapsed before the significance of the aerial force could be appreciated, while means of counter acting or nullifying its influences had to be evolved simultaneously, and according to the exigencies of the moment. At all events, the protagonists were somewhat loth to utilise the dirigible upon an elaborate scale or in an aggressive manner. It was employed more after the fashion of a captive balloon, being sent aloft from a point well behind the front lines of the force to which it was attached, and well out of the range of hostile guns. Its manoeuvres were somewhat circumscribed, and were carried out at a safe distance from the enemy, dependence being placed upon the advantages of an elevated position for the gathering of information. But as the campaign progressed, the airships became more daring. Their ability to soar to a great height offered them complete protection against gun-fire, and accordingly sallies over the hostile lines were carried out. But even here a certain hesitancy became manifest. This was perfectly excusable, for the simple reason that the dirigible, above all, is a fair-weather craft, and disasters, which had overtaken these vessels time after time, rendered prudence imperative. Moreover, but little was known of the range and destructiveness of anti-aircraft guns. In the duty of reconnoitring the dirigible possesses one great advantage over its heavier-than-air rival. It can remain virtually stationary in the air, the propellers revolving at just sufficient speed to off-set the wind and tendencies to drift. In other words, it has the power of hovering over a position, thereby enabling the observers to complete their task carefully and with deliberation. On the other hand, the means of enabling an aeroplane to hover still remain to be discovered. It must travel at a certain speed through the air to maintain its dynamic equilibrium, and this speed is often too high to enable the airman to complete his reconnaissance with sufficient accuracy to be of value to the forces below. All that the aeroplane can do is to circle above a certain position until the observer is satisfied with the data he has collected. But hovering on the part of the dirigible is not without conspicuous drawbacks. The work of observation cannot be conducted with any degree of accuracy at an excessive altitude. Experience has proved that the range of the latest types of anti-aircraft weapons is in excess of anticipations. The result is that the airship is useless when hovering beyond the zone of fire. The atmospheric haze, even in the clearest weather, obstructs the observer's vision. The caprices of this obstacle are extraordinary, as anyone who has indulged in ballooning knows fully well. On a clear summer's day I have been able to see the ground beneath with perfect distinctness from a height of 4,500 feet, yet when the craft had ascended a further two or three hundred feet, the panorama was blurred. A film of haze lies between the balloon and the ground beneath. And the character of this haze is continually changing, so that the aerial observer's task is rendered additionally difficult. Its effects are particularly notice able when one attempts to photograph the view unfolded below. Plate after plate may be exposed and nothing will be revealed. Yet at a slightly lower altitude the plates may be exposed and perfectly sharp and well-defined images will be obtained. Seeing that the photographic eye is keener and more searching than the human organ of sight, it is obvious that this haze constitutes a very formidable obstacle. German military observers, who have accompanied the Zeppelins and Parsevals on numerous aerial journeys under varying conditions of weather, have repeatedly drawn attention to this factor and its caprices, and have not hesitated to venture the opinion that it would interfere seriously with military aerial reconnaissances, and also that it would tend to render such work extremely hazardous at times. When these conditions prevail the dirigible must carry out its work upon the broad lines of the aeroplane. It must descend to the level where a clear view of the ground may be obtained, and in the interests of safety it has to keep on the move. To attempt to hover within 4,000 feet of the ground is to court certain disaster, inasmuch as the vessel offers a magnificent and steady target which the average gunner, equipped with the latest sighting devices and the most recent types of guns, scarcely could fail to hit. But the airman in the aeroplane is able to descend to a comparatively low level in safety. The speed and mobility of his machine constitute his protection. He can vary his altitude, perhaps only thirty or forty feet, with ease and rapidity, and this erratic movement is more than sufficient to perplex the marksmen below, although the airman is endangered if a rafale is fired in such a manner as to cover a wide zone. Although the aeroplane may travel rapidly it is not too fleet for a keen observer who is skilled in his peculiar task. He may only gather a rough idea of the disposition of troops, their movements, the lines of communication, and other details which are indispensable to his commander, but in the main the intelligence will be fairly accurate. Undulating flight enables him to determine speedily the altitude at which he is able to obtain the clearest views of the country beneath. Moreover, owing to his speed he is able to complete his task in far less time than his colleague operating in the dirigible, the result being that the information placed at the disposal of his superior officers is more to the moment, and accordingly of greater value. Reconnoitring by aeroplane may be divided into two broad categories, which, though correlated to a certain degree, are distinctive, because each constitutes a specific phase in military operations. They are known respectively as "tactical" and "strategical" movements. The first is somewhat limited in its scope as compared with the latter, and has invariably to be carried out rapidly, whereas the strategical reconnaissance may occupy several hours. The tactical reconnaissance concerns the corps or divisional commander to which the warplane is attached, and consequently its task is confined to the observation of the line immediately facing the particular corps or division. The aviator does not necessarily penetrate beyond the lines of the enemy, but, as a rule limits his flight to some distance from his outermost defences. The airman must possess a quick eye, because his especial duty is to note the disposition of the troops immediately facing him, the placing of the artillery, and any local movements of the forces that may be in progress. Consequently the aviator engaged on this service may be absent from his lines for only a few minutes, comparatively speaking; the intelligence he acquires must be speedily communicated to the force to which he is attached, because it may influence a local movement. The strategical reconnaissance, on the other hand, affects the whole plan of campaign. The aviators told off for this duty are attached to the staff of the Commander-in-Chief, and the work has to be carried out upon a far more comprehensive and elaborate scale, while the airmen are called upon to penetrate well into the hostile territory to a point thirty, forty, or more miles beyond the outposts. The procedure is to instruct the flier either to carry out his observations of the territory generally, or to report at length upon a specified stretch of country. In the latter event he may fly to and fro over the area in question until he has acquired all the data it is possible to collect. His work not only comprises the general disposition of troops, defences, placing of artillery, points where reserves are being held, high-roads, railways, base camps, and so forth, but he is also instructed to bring back as correct an idea as possible of what the enemy proposes to do, so that his Commander-in-Chief may adjust his moves accordingly. In order to perform this task with the requisite degree of thoroughness it is often necessary for the airman to remain in the air for several hours continuously, not returning, in fact, until he has completed the allotted duty. The airman engaged in strategical aerial reconnaissance must possess, above all things, what is known as a "military" eye concerning the country he traverses. He must form tolerably correct estimates of the forces beneath and their character. He must possess the ability to read a map rapidly as he moves through the air and to note upon it all information which is likely to be of service to the General Staff. The ability to prepare military sketches rapidly and intelligibly is a valuable attribute, and skill in aerial photography is a decidedly useful acquisition. Such men must be of considerable stamina, inasmuch as great demands are made upon their powers of endurance. Being aloft for several hours imposes a severe tax upon the nervous system, while it must also be borne in mind that all sorts and conditions of weather are likely to be encountered, more particularly during the winter. Hail, rain, and blizzards may be experienced in turn, while the extreme cold which often prevails in the higher altitudes during the winter season is a fearful enemy to combat. Often an airman upon his return from such a reconnaissance has been discovered to be so numbed and dazed as a result of the prolonged exposure, that considerable time has elapsed before he has been sufficiently restored to set forth the results of his observations in a coherent, intelligible manner for the benefit of the General Staff. Under these circumstances it is not surprising that the most skilful and experienced aviators are generally reserved for this particular work. In addition to the natural accidents to which the strategical aerial observer is exposed, the dangers arising from hostile gun-fire must not be overlooked. He is manoeuvring the whole time over the enemy's firing zone, where anti-aircraft weapons are disposed strategically, and where every effort is made by artillery to bring him down, or compel him to repair to such a height as to render observation with any degree of accuracy well-nigh impossible. The methods practised by the German aerial scout vary widely, and are governed in no small measure by the intrepidity and skill of the airman himself. One practice is to proceed alone upon long flights over the enemy's lines, penetrating just as far into hostile territory as the pilot considers advisable, and keeping, of course, within the limits of the radius of action of the machine, as represented by the fuel supply, the while carefully taking mental stock of all that he observes below. It is a kind of roving commission without any definite aim in view beyond the collection of general intelligence. This work, while productive and valuable to a certain degree, is attended with grave danger, as the German airmen have repeatedly found to their cost. Success is influenced very materially by the accuracy of the airman's judgment. A slight miscalculation of the velocity and direction of the wind, or failure to detect any variations in the climatic conditions, is sufficient to prove his undoing. German airmen who essayed journeys of discovery in this manner, often failed to regain their lines because they ventured too far, misjudged the speed of the wind which was following them on the outward run, and ultimately were forced to earth owing to the exhaustion of the fuel supply during the homeward trip; the increased task imposed upon the motor, which had to battle hard to make headway, caused the fuel consumption per mile to exceed calculations. Then the venturesome airman cannot neglect another factor which is adverse to his success. Hostile airmen lie in wait, and a fleet of aeroplanes is kept ready for instant service. They permit the invader to penetrate well into their territory and then ascend behind him to cut off his retreat. True, the invader has the advantage of being on the wing, while the ether is wide and deep, without any defined channels of communication. But nine times out of ten the adventurous scout is trapped. His chances of escape are slender, because his antagonists dispose themselves strategically in the air. The invader outpaces one, but in so doing comes within range of another. He is so harassed that he either has to give fight, or, finding his retreat hopelessly cut off, he makes a determined dash, trusting to his high speed to carry him to safety. In these driving tactics the French and British airmen have proved themselves adepts, more particularly the latter, as the chase appeals to their sporting instincts. There is nothing so exhilarating as a quarry who displays a determination to run the gauntlet. The roving Teuton scout was considerably in evidence in the early days of the war, but two or three weeks' experience emphasised the sad fact that, in aerial strategy, he was hopelessly outmatched by his opponents. His advantage of speed was nullified by the superior tactical and strategical acumen of his antagonists, the result being that the German airman, who has merely been trained along certain lines, who is in many cases nothing more than a cog-wheel in a machine, and who is proverbially slow-witted, has concluded that he is no match for the airmen of the Allies. He found from bitter experience that nothing afforded the Anglo-French military aviators such keen delight as to lie in wait for a "rover," and then to swoop into the air to round him up. The proportion of these individual scouts who were either brought down, or only just succeeded in reaching safety within their own lines, and who were able to exhibit serious wounds as evidence of the severity of the aerial tussle, or the narrowness of the escape, has unnerved the Teuton airmen as a body to a very considerable extent. Often, even when an aeroplane descended within the German lines, it was found that the roving airman had paid the penalty for his rashness with his life, so that his journey had proved in vain, because all the intelligence he had gained had died with him, or, if committed to paper, was so unintelligible as to prove useless. It was the success of the British airmen in this particular field of duty which was responsible for the momentous declaration in Field-Marshal Sir John French's famous despatch:--"The British Flying Corps has succeeded in establishing an individual ascendancy, which is as serviceable to us as it is damaging to the enemy.... The enemy have been less enterprising in their flights. Something in the direction of the mastery of the air has already been gained." The methods of the British airmen are in vivid contrast to the practice of the venturesome Teuton aerial rovers described above. While individual flights are undertaken they are not of unknown duration or mileage. The man is given a definite duty to perform and he ascends merely to fulfil it, returning with the information at the earliest possible moment. It is aerial scouting with a method. The intelligence is required and obtained for a specific purpose, to govern a contemplated move in the grim game of war. Even then the flight is often undertaken by two or more airmen for the purpose of checking and counterchecking information gained, or to ensure such data being brought back to headquarters, since it is quite possible that one of the party may fall a victim to hostile fire. By operating upon these lines there is very little likelihood of the mission proving a complete failure. Even when raids upon certain places such as Dusseldorf, Friedrichshafen or Cuxhaven are planned, complete dependence is not placed on one individual. The machine is accompanied, so that the possibility of the appointed task being consummated is transformed almost into a certainty. The French flying men work upon broadly similar lines. Their fleet is divided into small squadrons each numbering four, six, or more machines, according to the nature of the contemplated task. Each airman is given an area of territory which is to be reconnoitred thoroughly. In this way perhaps one hundred or more miles of the enemy's front are searched for information at one and the same time. The units of the squadron start out, each taking the appointed direction according to the preconceived plan, and each steering by the aid of compass and map. They are urged to complete the work with all speed and to return to a secret rendezvous. Later the air is alive with the whirring of motors. The machines are coming back and all converging to one point. They vol-plane to the earth and gracefully settle down within a short distance of each other at the rendezvous. The pilots collect and each relates the intelligence he has gained. The data are collated and in this manner the General Staff is able to learn exactly what is transpiring over a long stretch of the hostile lines, and a considerable distance to the rear of his advance works. Possibly five hundred square miles have been reconnoitred in this manner. Troops have been massed here, lines of communication extend somewhere else, while convoys are moving at a third place. But all has been observed, and the commanding officer is in a position to re-arrange his forces accordingly. It is a remarkable example of method in military tactics and strategy, and conveys a striking idea of the degree to which aerial operations have been organised. After due deliberation it is decided that the convoys shall be raided, or that massed troops shall be thrown into confusion, if not dispersed. The squadron is ordered to prepare for another aerial journey. The roads along which the convoys are moving are indicated upon the map, or the position of the massed troops in bivouac is similarly shown. The airmen load their machines with a full charge of bombs. When all is ready the leader ascends, followed in rapid succession by the other units, and they whirr through the air in single file. It now becomes a grim game of follow-my-leader. The leader detects the convoy, swoops down, suddenly launches his missiles, and re-ascends. He does not deviate a foot from his path to observe the effects of his discharge, as the succeeding aeroplane is close behind him. If the leader has missed then the next airman may correct his error. One after another the machines repeat the manoeuvre, in precisely the same manner as the units of a battleship squadron emulate the leading vessel when attacking the foe. The tactical evolutions have been laid down, and there is rigid adherence thereto, because only thereby may success be achieved. When the last war-plane has completed its work, the leader swings round and repeats the dash upon the foe. A hail of bullets may scream around the men in the air, but one and all follow faithfully in the leader's trail. One or more machines may fail in the attack, and may even meet with disaster, but nothing interferes with the movements of the squadron as a whole. It is the homogeneity of the attacking fleet which tells, and which undermines the moral of the enemy, even if it does not wreak decisive material devastation. The work accomplished to the best of their ability, the airmen speed back to their lines in the same formation. At first sight reconnoitring from aloft may appear a simple operation, but a little reflection will reveal the difficulties and arduousness of the work. The observer, whether he be specially deputed, or whether the work be placed in the hand of the pilot himself--in this event the operation is rendered additionally trying, as he also has to attend to his machine must keep his eyes glued to the ground beneath and at the same time be able to read the configuration of the panorama revealed to him. He must also keep in touch with his map and compass, so as to be positive of his position and direction. He must be a first-class judge of distances and heights. When flying rapidly at a height of 4,000 feet or more, the country below appears as a perfect plane, or flat stretch, although as a matter of fact it may be extremely undulating. Consequently, it is by no means a simple matter to distinguish eminences and depressions, or to determine the respective and relative heights of hills. If a rough sketch is required, the observer must be rapid in thought, quick in determination, and facile with his pencil, as the machine, no matter how it may be slowed down, is moving at a relatively high speed. He must consult his map and compass frequently, since an airman who loses his bearings is useless to his commander-in-chief. He must have an eagle eye, so as to be able to search the country unfolded below, in order to gather all the information which is likely to be of value to his superior officers. He must be able to judge accurately the numbers of troops arrayed beneath him, the lines of the defensive works, to distinguish the defended from the dummy lines which are thrown up to baffle him, and to detect instantly the movement of the troops and the direction, as well as the roads, along which they are proceeding. Reserves and their complement, artillery, railway-lines, roads, and bridges, if any, over streams and railways must be noted--in short he must obtain an eye photograph of the country he observes and grasp exactly what is happening there. In winter, with the thermometer well down, a blood-freezing wind blowing, wreaths of clouds drifting below and obscuring vision for minutes at a time, the rain possibly pelting down as if presaging a second deluge, the plight of the vigilant human eye aloft is far from enviable. Upon the return of the machine to its base, the report must be prepared without delay. The picture recorded by the eye has to be set down clearly and intelligibly with the utmost speed. The requisite indications must be made accurately upon the map. Nothing of importance must be omitted: the most trivial detail is often of vital importance. A facile pencil is of inestimable value in such operations. While aloft the observer does not trust to his memory or his eye picture, but commits the essential factors to paper in the form of a code, or what may perhaps be described more accurately as a shorthand pictorial interpretation of the things he has witnessed. To the man in the street such a record would be unintelligible, but it is pregnant with meaning, and when worked out for the guidance of the superior officers is a mass of invaluable detail. At times it so happens that the airman has not been able to complete his duty within the time anticipated by those below. But he has gathered certain information which he wishes to communicate without coming to earth. Such data may be dropped from the clouds in the form of maps or messages. Although wireless telegraphy is available for this purpose, it suffers from certain drawbacks. If the enemy possesses an equipment which is within range of that of the air-craft and the force to which it belongs, communications may be nullified by the enemy throwing out a continuous stream of useless signals which "jamb" the intelligence of their opponents. If a message--written in code--or a map is to be dropped from aloft it is enclosed within a special metallic cylinder, fitted with a vane tail to ensure direction of flight when launched, and with a detonating head. This is dropped overboard. When it strikes the ground the detonator fires a charge which emits a report without damaging the message container, and at the same time fires a combustible charge emitting considerable smoke. The noise attracts anyone in the vicinity of the spot where the message has fallen, while at the same time the clouds of smoke guide one to the point and enable the cylinder to be recovered. This device is extensively used by the German aviators, and has proved highly serviceable; a similar contrivance is adopted by French airmen. There is one phase of aerial activity which remains to be demonstrated. This is the utilisation of aerial craft by the defenders of a besieged position such as a ring of fortifications or fortified city. The utility of the Fourth Arm in this province has been the subject of considerable speculation. Expert opinion maintains that the advantage in this particular connection would rest with the besiegers. The latter would be able to ascertain the character of the defences and the defending gun-force, by means of the aerial scout, who would prove of inestimable value in directing the fire of the besieging forces. On the other hand it is maintained that an aerial fleet would be useless to the beleaguered. In the first place the latter would experience grave difficulties in ascertaining the positions of the attacking and fortress-reducing artillery, inasmuch as this could be masked effectively, and it is thought that the aerial force of the besieged would be speedily reduced to impotence, since it would be subjected to an effective concentrated fire from the ring of besieging anti-aircraft guns and other weapons. In other words, the theory prevails that an aerial fleet, no matter how efficient, would be rendered ineffective for the simple reason that it would be the initial object of the besieger's attack. Possibly the stem test of experience will reveal the fallacy of these contentions as emphatically as it has disproved others. But there is one point upon which authorities are unanimous. If the artillery of the investing forces is exposed and readily distinguishable, the aerial forces of the beleaguered will bring about its speedy annihilation, as the defensive artillery will be concentrated upon that of the besiegers. CHAPTER IX. THE AIRMAN AND ARTILLERY There is one field in which the airman has achieved distinctive triumphs. This is in the guidance of artillery fire. The modern battle depends first and foremost upon the fierce effectiveness of big-gun assault, but to ensure this reliable direction is imperative. No force has proved so invaluable for this purpose as the man of-the-air, and consequently this is the province in which he has been exceptionally and successfully active. It will be recalled that in the Japanese investiture of Port Arthur during the Russo-Japanese war, thousands of lives were expended upon the retention and assault of 203 Metre Hill. It was the most blood-stained spot upon the whole of the Eastern Asiatic battlefield. General Nogi threw thousands after thousands of his warriors against this rampart while the Russians defended it no less resolutely. It was captured and re-captured; in fact, the fighting round this eminence was so intense that it appeared to the outsider to be more important to both sides than even Port Arthur itself. Yet if General Nogi had been in the possession of a single aeroplane or dirigible it is safe to assert that scarcely one hundred Japanese or Russian soldiers would have met their fate upon this hill. Its value to the Japanese lay in one sole factor. The Japanese heavy guns shelling the harbour and the fleet it contained were posted upon the further side of this eminence and the fire of these weapons was more or less haphazard. No means of directing the artillery upon the vital points were available; 203 Metre Hill interrupted the line of sight. The Japanese thereupon resolved to capture the hill, while the Russians, equally appreciative of the obstruction it offered to their enemy, as valiantly strove to hold it. Once the hill was captured and the fire of the Japanese guns could be directed, the fate of the fortress was sealed. Similar conditions have prevailed during the present campaign, especially in the western theatre of war, where the ruggedness of the country has tended to render artillery fire ineffective and expensive unless efficiently controlled. When the German Army attacked the line of the British forces so vehemently and compelled the retreat at Mons, the devastating fire of the enemy's artillery was directed almost exclusively by their airmen, who hovered over the British lines, indicating exactly the point where gun-fire could work the maximum of havoc. The instant concentration of massed artillery fire upon the indicated positions speedily rendered one position after another untenable. The Germans maintained the upper hand until at last the aerial forces of the British Expeditionary Army came into action. These airmen attacked the Teuton aerial craft without the slightest hesitation, and in a short while rendered cloudland absolutely unhealthy. The sequel was interesting. As if suddenly blinded, the German artillery fire immediately deteriorated. On the other hand, the British artillery, now having the benefit of aerial guidance, was able to repay the German onslaughts with interest, and speedily compelled that elaborate digging-in of the infantry lines which has now become so characteristic of the opposing forces. So far as the British lines are concerned the men in the trenches keep a sharp look-out for hostile aeroplanes. The moment one is observed to be advancing, all the men seclude themselves and maintain their concealment. To do otherwise is to court a raking artillery outburst. The German aeroplane, detecting the tendency of the trenches describes in the air the location of the vulnerable spot and the precise disposition by flying immediately above the line. Twice the manoeuvre is repeated, the second movement evidently being in the character of a check upon the first observation, and in accordance with instructions, whereupon the Tommies, to quote their own words, "know they are in for it!" Ere the aeroplane has completed the second manoeuvre the German guns ring out. The facility with which artillery fire can be concentrated through the medium of the aeroplane is amazing. In one instance, according to the story related to me by an officer, "a number of our men were resting in an open field immediately behind the second line of trenches, being in fact the reserves intended for the relief of the front lines during the following night. An aeroplane hove in sight. The men dropped their kits and got under cover in an adjacent wood. The aeroplane was flying at a great height and evidently laboured under the impression that the kits were men. Twice it flew over the field in the usual manner, and then the storm of shrapnel, 'Jack Johnsons' and other tokens from the Kaiser rained upon the confined space. A round four hundred shells were dropped into that field in the short period of ten minutes, and the range was so accurate that no single shell fell outside the space. Had the men not hurried to cover not one would have been left alive to tell the tale, because every square foot of the land was searched through and through. We laughed at the short-sightedness of the airman who had contributed to such a waste of valuable shot and shell, but at the same time appreciated the narrowness of our own escape." The above instance is by no means isolated. It has happened time after time. The slightest sign of activity in a trench when a "Taube" is overhead suffices to cause the trench to be blown to fragments, and time after time the British soldiers have had to lie prone in their trenches and suffer partial burial as an alternative to being riddled by shrapnel. The method of ascertaining the range of the target from the indications given by the aeroplane are of the simplest character. The German method is for the aerial craft to fly over the position, and when in vertical line therewith to discharge a handful of tinsel, which, in falling, glitters in the sunlight, or to launch a smoking missile which answers the same purpose as a projectile provided with a tracer. This smoke-ball being dropped over the position leaves a trail of black or whitish smoke according to the climatic conditions which prevail, the object being to enable the signal to be picked up with the greatest facility. The height at which the aerial craft is flying being known, a little triangulation upon the part of the observer at the firing point enables him to calculate the range and to have the guns laid accordingly. When the aerial craft has been entrusted with the especial duty of directing artillery-fire, a system of communication between the aerial observer and the officer in charge of the artillery is established, conducted, of course, by code. In the British Army, signalling is both visual and audible. In daylight visual signalling is carried out by means of coloured flags or streamers and smoke-signals, while audible communication is effected by means of a powerful horn working upon the siren principle and similar to those used by automobiles. Both flags and sound-signals, however, are restricted owing to the comparatively short distances over which they can be read with any degree of accuracy. The smoke-signal therefore appears to be the most satisfactory and reliable, as the German airmen have proved conclusively, for the simple reason that the trail of smoke may be picked up with comparative ease, even at a distance, by means of field glasses. The tinsel too, is readily distinguishable, particularly in bright weather, for the glittering surface, catching the sun-light, acts some what in the manner of a heliograph. The progress of the airman is followed by two officers at the base from which he started. One is equipped with the director, while the second takes the range. Directly this has been found as a result of calculation, the guns are laid ready for firing. In those cases where the enemy's artillery is concealed perhaps behind a hill, the airman is of incalculable value, inasmuch as he is able to reveal a position which otherwise would have to be found by considerable haphazard firing, and which, even if followed by a captive balloon anchored above the firing point, might resist correction. The accuracy of the airman's work in communicating the range has been responsible for the high efficiency of the British and French artillery. The latter, with the 75 millimetre quick-firing gun, is particularly adapted to following up the results of the aeroplane's reconnaissance, especially with the system of rafale fire, because the whole position can be searched through and through within a minute or two. According to information which has been given to me by our artillery officers, the British system also has proved disastrous to the enemy. The practice is to get the range as communicated by the aeroplane, to bring the artillery into position speedily, to discharge salvo after salvo with all speed for a few minutes, and then to wheel the artillery away before any hostile fire can be returned. The celerity with which the British artillery comes into, and goes out of, action has astonished even our own authorities. This mobility is of unique value: it is taking advantage of a somewhat slow-witted enemy with interest. By the time the Germans have opened fire upon the point whence the British guns were discharged, the latter have disappeared and are ready to let fly from another point, some distance away, so that the hostile fire is abortive. Mobility of such a character is decidedly unnerving and baffling even to a quick-witted opponent. In his search for hostile artillery the airman runs grave risks and displays remarkable resource. It is invariably decided, before he sets out, that he shall always return to a certain altitude to communicate signals. Time after time the guns of the enemy have been concealed so cunningly from aerial observation as to pass unnoticed. This trait became more pronounced as the campaigns of the Aisne progressed. Accordingly the airman adopts a daring procedure. He swoops down over suspicious places, where he thinks guns may be lurking, hoping that the enemy will betray its presence. The ruse is invariably successful. The airman makes a sudden dive towards the earth. The soldiers in hiding below, who have become somewhat demoralised by the accuracy of the British aerial bomb-throwers, have an attack of nerves. They open a spirited fusillade in the hope of bringing the airman to earth. But their very excitement contributes to his safety. The shots are fired without careful aim and expend themselves harmlessly. Sweeping once more upwards, the airman regains the pre-determined level, performs a certain evolution in the air which warns the observer at his base that he has made a discovery, and promptly drops his guiding signal directly over the point from which he has drawn fire. Operations at night are conducted by means of coloured lights or an electrical searchlight system. In the former instance three lights are generally carried--white, red, and green--each of which has a distinctive meaning. If reliance is placed upon the electric light signalling lamp, then communications are in code. But night operations are somewhat difficult and extremely dangerous, except when the elements are propitious. There is the ground mist which blots everything from sight, rendering reconnaissance purely speculative. But on a clear night the airman is more likely to prove successful. He keeps a vigilant eye upon all ground-lights and by close observation is able to determine their significance. It is for this reason that no lights of any description are permitted in the advance trenches. The striking of a match may easily betray a position to the alert eye above. So far as the British Army is concerned a complete code is in operation for communicating between aeroplanes and the ground at night. Very's lights are used for this purpose, it being possible to distinguish the respective colours at a distance of six miles and from an altitude of 2,000 feet. The lights are used both by the aeroplane and the battery of artillery. The code is varied frequently, but the following conveys a rough idea of how communication is carried out by this means under cover of darkness. The aeroplane has located its objective and has returned to the pre-arranged altitude. A red light is thrown by the airman. It indicates that he is directly over the enemy's position. A similarly coloured light is shown by the artillery officer, which intimates to the airman that his signal has been observed and that the range has been taken. In observing the effects of artillery fire a code of signals is employed between the airman and the artillery officer to indicate whether the shot is "long" or "short," to the right or to the left of the mark, while others intimate whether the fuse is correctly timed or otherwise. It is necessary to change the code fairly frequently, not only lest it should fall into the enemy's hands, but also to baffle the hostile forces; otherwise, after a little experience, the latter would be able to divine the significance of the signals, and, in anticipation of being greeted with a warm fusillade, would complete hurried arrangements to mitigate its effects, if not to vacate the position until the bombardment had ceased. Sufficient experience has already been gathered, however, to prove the salient fact that the airman is destined to play an important part in the direction and control of artillery-fire. Already he has been responsible for a re-arrangement of strategy and tactics. The man aloft holds such a superior position as to defy subjugation; the alternative is to render his work more difficult, if not absolutely impossible. CHAPTER X. BOMB-THROWING FROM AIR-CRAFT During the piping times of peace the utility of aircraft as weapons of offence was discussed freely in an academic manner. It was urged that the usefulness of such vessels in this particular field would be restricted to bomb-throwing. So far these contentions have been substantiated during the present campaign. At the same time it was averred that even as a bomb-thrower the ship of the air would prove an uncertain quantity, and that the results achieved would be quite contrary to expectations. Here again theory has been supported by practice, inasmuch as the damage wrought by bombs has been comparatively insignificant. The Zeppelin raids upon Antwerp and Britain were a fiasco in the military sense. The damage inflicted by the bombs was not at all in proportion to the quantity of explosive used. True, in the case of Antwerp, it demoralised the civilian population somewhat effectively, which perhaps was the desired end, but the military results were nil. The Zeppelin, and indeed all dirigibles of large size, have one advantage over aeroplanes. They are able to throw bombs of larger size and charged with greater quantities of high explosive and shrapnel than those which can be hurled from heavier-than-air machines. Thus it has been stated that the largest Zeppelins can drop single charges exceeding one ton in weight, but such a statement is not to be credited. The shell generally used by the Zeppelin measures about 47 inches in length by 8 1/2 inches in diameter, and varies in weight from 200 to 242 pounds. Where destruction pure and simple is desired, the shell is charged with a high explosive such as picric acid or T.N.T., the colloquial abbreviation for the devastating agent scientifically known as "Trinitrotoluene," the base of which, in common with all the high explosives used by the different powers and variously known as lyddite, melinite, cheddite, and so forth, is picric acid. Such a bomb, if it strikes the objective, a building, for instance, fairly and squarely, may inflict widespread material damage. On the other hand, where it is desired to scatter death, as well as destruction, far and wide, an elaborate form of shrapnel shell is utilised. The shell in addition to a bursting charge, contains bullets, pieces of iron, and other metallic fragments. When the shell bursts, their contents, together with the pieces of the shell which is likewise broken up by the explosion, are hurled in all directions over a radius of some 50 yards or more, according to the bursting charge. These shells are fired upon impact, a detonator exploding the main charge. The detonator, comprising fulminate of mercury, is placed in the head or tail of the missile. To secure perfect detonation and to distribute the death-dealing contents evenly in all directions, it is essential that the bomb should strike the ground almost at right angles: otherwise the contents are hurled irregularly and perhaps in one direction only. One great objection to the percussion system, as the method of impact detonation is called, is that the damage may be localised. A bomb launched from a height of say 1,000 feet attains terrific velocity, due to the force of gravity in conjunction with its own weight, in consonance with the law concerning a falling body, by the time it reaches the ground. It buries itself to a certain depth before bursting so that the forces of the explosion become somewhat muffled as it were. A huge deep hole--a miniature volcano crater--is formed, while all the glass in the immediate vicinity of the explosion may be shattered by the concussion, and the walls of adjacent buildings be bespattered with shrapnel. Although it is stated that an airship is able to drop a single missile weighing one ton in weight, there has been no attempt to prove the contention by practice. In all probability the heaviest shell launched from a Zeppelin has not exceeded 300 pounds. There is one cogent reason for such a belief. A bomb weighing one ton is equivalent to a similar weight of ballast. If this were discarded suddenly the equilibrium of the dirigible would be seriously disturbed--it would exert a tendency to fly upwards at a rapid speed. It is doubtful whether the planes controlling movement in the vertical plane would ever be able to counteract this enormous vertical thrust. Something would have to submit to the strain. Even if the dirigible displaced say 20 tons, and a bomb weighing one ton were discharged, the weight of the balloon would be decreased suddenly by approximately five per cent, so that it would shoot upwards at an alarming speed, and some seconds would elapse before control was regained. The method of launching bombs from airships varies considerably. Some are released from a cradle, being tilted into position ready for firing, while others are discharged from a tube somewhat reminiscent of that used for firing torpedoes, with the exception that little or no initial impetus is imparted to the missile; the velocity it attains is essentially gravitational. The French favour the tube-launching method since thereby it is stated to be possible to take more accurate aim. The objective is sighted and the bomb launched at the critical moment. In some instances the French employ an automatic detonator which corresponds in a certain measure to the time-fuse of a shrapnel shell fired from a gun. The bomb-thrower reads the altitude of his airship as indicated by his barometer or other recording instrument, and by means of a table at his command ascertains in a moment the time which will elapse before the bomb strikes the ground. The automatic detonator is set in motion and the bomb released to explode approximately at the height to which it is set. When it bursts the full force of the explosion is distributed downwards and laterally. Owing to the difficulty of ensuring the explosion of the bomb at the exact height desired, it is also made to explode upon impact so as to make doubly sure of its efficacy. Firing timed bombs from aloft, however, is not free from excitement and danger, as the experience of a French airman demonstrates. His dirigible had been commanded to make a night-raid upon a railway station which was a strategical junction for the movement of the enemy's troops. Although the hostile searchlights were active, the airship contrived to slip between the spokes of light without being observed. By descending to a comparatively low altitude the pilot was able to pick up the objective. Three projectiles were discharged in rapid succession and then the searchlights, being concentrated, struck the airship, revealing its presence to the troops below. Instantly a spirited fusillade broke out. The airmen, by throwing ballast and other portable articles overboard pell-mell, rose rapidly, pursued by the hostile shells. In the upward travel the bomb-thrower decided to have a parting shot. The airship was steadied momentarily to enable the range to be taken, the automatic detonator was set going and the bomb slipped into the launching tube. But for some reason or other the missile jambed. The situation was desperate. In a few seconds the bomb would burst and shatter the airship. The bomb-thrower grabbed a tool and climbing into the rigging below hacked away at the bomb-throwing tube until the whole equipment was cut adrift and fell clear of the vessel. Almost instantly there was a terrific explosion in mid-air. The blast of air caused the vessel to roll and pitch in a disconcerting manner, but as the airman permitted the craft to continue its upward course unchecked, she soon steadied herself and was brought under control once more. The bomb carried by aeroplanes differs consider ably from that used by dirigibles, is smaller and more convenient to handle, though considering its weight and size it is remarkably destructive. In this instance complete reliance is placed upon detonation by impact. The latest types of British war-plane bombs have been made particularly formidable, those employed in the "raids in force" ranging up to 95 pounds in weight. The type of bomb which has proved to be the most successful is pear-shaped. The tail spindle is given an arrow-head shape, the vanes being utilised to steady the downward flight of the missile. In falling the bomb spins round, the rotating speed increasing as the projectile gathers velocity. The vanes act as a guide, keeping the projectile in as vertical a plane as possible, and ensuring that the rounded head shall strike the ground. The earlier types of bombs were not fitted with these vanes, the result being that sometimes they turned over and over as they fell through the air, while more often than not they failed to explode upon striking the ground. The method of launching the bomb also varies considerably, experience not having indicated the most efficient method of consummating this end. In some cases the bombs are carried in a cradle placed beneath the aeroplane and launched merely by tilting them in a kind of sling, one by one, to enable them to drop to the ground, this action being controlled by means of a lever. In another instance they are dropped over the side of the car by the pilot, the tail of the bomb being fitted with a swivel and ring to facilitate the operation. Some of the French aviators favour a still simpler method. The bomb is attached to a thread and lowered over the side. At the critical moment it is released simply by severing the thread. Such aeroplane bombs, however, constitute a menace to the machine and to the pilot. Should the bomb be struck by hostile rifle or shell fire while the machine is aloft, an explosion is probable; while should the aero plane make an abrupt descent the missiles are likely to be detonated. A bomb which circumvents this menace and which in fact will explode only when it strikes the ground is that devised by Mr. Marten-Hale. This projectile follows the usual pear-shape, and has a rotating tail to preserve direction when in flight. The detonator is held away from the main charge by a collar and ball-bearing which are held in place by the projecting end of a screw-releasing spindle. When the bomb is dropped the rotating tail causes the spindle to screw upwards until the projection moves away from the steel balls, thereby allowing them to fall inward when the collar and the detonator are released. In order to bring about this action the bomb must have a fall of at least 200 feet. When the bomb strikes the ground the detonator falls down on the charge, fires the latter, and thus brings about the bursting of the bomb. The projectile is of the shrapnel type. It weighs 20 pounds complete, is charged with some four pounds of T.N.T., and carries 340 steel balls, which represent a weight of 5 3/4 pounds. The firing mechanism is extremely sensitive and the bomb will burst upon impact with the hull of an airship, water, or soft soil. This projectile, when discharged, speedily assumes the vertical position, so that there is every probability that it will strike the ground fairly and squarely, although at the same time such an impact is not imperative, because it will explode even if the angle of incidence be only 5 degrees. It is remarkably steady in its flight, the balancing and the design of the tail frustrating completely any tendency to wobble or to turn turtle while falling. Other types of missile may be used. For instance, incendiary bombs have been thrown with success in certain instances. These bombs are similar in shape to the shrapnel projectile, but are charged with petrol or some other equally highly inflammable mixture, and fitted with a detonator. When they strike the objective the bursting charge breaks up the shell, releasing the contents, and simultaneously ignites the combustible. Another shell is the smoke-bomb, which, up to the present, has been used only upon a restricted scale. This missile is charged with a certain quantity of explosive to burst the shell, and a substance which, when ignited, emits copious clouds of dense smoke. The scope of such a shell is somewhat restricted, it is used only for the purpose of obstructing hostile artillery fire. The shells are dropped in front of the artillery position and the clouds of smoke which are emitted naturally inter fere with the operations of the gunners. These bombs have also been used with advantage to denote the position of concealed hostile artillery, although their utility in this connection is somewhat uncertain, owing to the difficulty of dropping the bomb so accurately as to enable the range-finders to pick up the range. Dropping bombs from aloft appears to be a very simple operation, but as a matter of fact it is an extremely difficult matter to strike the target, especially from a high altitude. So far as the aeroplane is concerned it is somewhat at a disadvantage as compared with the airship, as the latter is able to hover over a position, and, if a spring-gun is employed to impart an initial velocity to the missile, there is a greater probability of the projectile striking the target provided it has been well-aimed. But even then other conditions are likely to arise, such as air-currents, which may swing the missile to one side of the objective. Consequently adequate allowance has to be made for windage, which is a very difficult factor to calculate from aloft. Bomb-dropping from an aeroplane is even more difficult. If for instance the aeroplane is speeding along at 60 miles an hour, the bomb when released will have a speed in the horizontal plane of 60 miles an hour, because momentarily it is travelling at the speed of the aeroplane. Consequently the shell will describe a curved trajectory, somewhat similar to that shown in Fig. 7. On the other hand, if the aeroplane is travelling slowly, say at 20 miles an hour, the curve of the trajectory will be flatter, and if a head wind be prevailing it may even be swept backwards somewhat after it has lost its forward momentum, and describe a trajectory similar to that in Fig. 8. A bomb released from an altitude of 1000 feet seldom, if ever, makes a bee-line for the earth, even if dropped from a stationary airship. Accordingly, the airman has to release the bomb before he reaches the target below. The determination of the critical moment for the release is not easy, inasmuch as the airman has to take into his calculations the speed of his machine, his altitude, and the direction and velocity of the air-currents. The difficulty of aiming has been demonstrated upon several occasions at aviation meetings and other similar gatherings. Monsieur Michelin, who has done so much for aviation in France, offered a prize of L1,00--$5,000--in 1912 for bomb-dropping from an aeroplane. The target was a rectangular space marked out upon the ground, measuring 170 feet long by 40 feet broad, and the missiles had to be dropped from a height of 2,400 feet. The prize was won by the well-known American airman, Lieutenant Riley E. Scott, formerly of the United States Army. He dropped his bombs in groups of three. The first round fell clear of the target, but eight of the remaining missiles fell within the area. In the German competition which was held at Gotha in September of the same year the results were somewhat disappointing. Two targets were provided. The one represented a military bivouac occupying a superficies of 330 square feet, and the other a captive balloon resembling a Zeppelin. The prizes offered were L500, L200, and L80--$2,500, $1,000 and $400--respectively, and were awarded to those who made the greatest number of hits. The conditions were by no means so onerous as those imposed in the Michelin contest, inasmuch as the altitude limit was set at 660 feet, while no machine was to descend within 165 feet. The first competitor completely failed to hit the balloon. The second competitor flying at 800 feet landed seven bombs within the square, but only one other competitor succeeded in placing one bomb within the space. Bomb-dropping under the above conditions, however, is vastly dissimilar from such work under the grim realities of war. The airman has to act quickly, take his enemy by surprise, avail himself of any protective covering which may exist, and incur great risks. The opposing forces are overwhelmingly against him. The modern rifle, if fired vertically into the air, will hurl the bullet to a height of about 5,000 feet, while the weapons which have been designed to combat aircraft have a range of 10,000 feet or more. At the latter altitude aggressive tactics are useless. The airman is unable to obtain a clear sharp view of the country beneath owing to the interference offered to vision by atmospheric haze, even in the dearest of weather. In order to obtain reasonable accuracy of aim the corsair of the sky must fly at about 400 feet. In this respect, however, the aeroplane is at a decided advantage, as compared with the dirigible. The machine offers a considerably smaller target and moves with much greater speed. Experience of the war has shown that to attempt to hurl bombs from an extreme height is merely a waste of ammunition. True, they do a certain amount of damage, but this is due to luck, not judgment. For success in aerial bomb operations the human element is mainly responsible. The daring airman is likely to achieve the greatest results, as events have proved, especially when his raid is sudden and takes the enemy by surprise. The raids carried out by Marix, Collet, Briggs, Babington, Sippe and many others have established this fact incontrovertibly. In all these operations the airmen succeeded because of their intrepidity and their decision to take advantage of cover, otherwise a prevailing mist or low-lying clouds. Flight-Lieutenant Collet approached the Zeppelin shed at Dusseldorf at an altitude of 6,000 feet. There was a bank of mist below, which he encountered at 1,500 feet. He traversed the depth of this layer and emerged therefrom at a height of only 400 feet above the ground. His objective was barely a quarter of a mile ahead. Travelling at high speed he launched his bombs with what proved to be deadly precision, and disappeared into cover almost before the enemy had grasped his intentions. Lieutenant-Commander, now Flight-Commander, Marix was even more daring. Apparently he had no mist in which to conceal himself but trusted almost entirely to the speed of his machine, which probably at times notched 90 miles per hour. Although his advent was detected and he was greeted with a spirited fusillade he clung to his determined idea. He headed straight for the Zeppelin shed, launched two bombs and swung into the higher reaches of the air without a moment's hesitation. His aim was deadly, since both bombs found their mark, and the Zeppelin docked within was blown up. The intrepid airman experienced several narrow escapes, for his aeroplane was struck twenty times, and one or two of the control wires were cut by passing bullets. The raid carried out by Commanders Briggs and Babington in company with Lieutenant Sippe upon the Zeppelin workshops at Friedrichshafen was even more daring. Leaving the Allies' lines they ascended to an altitude of 4,500 feet, and at this height held to the pre-arranged course until they encountered a mist, which while protecting them from the alert eyes of the enemy below, was responsible for the separation of the raiders, so that each was forced to act independently and to trust to the compass to bring him out of the ordeal successfully. Lieutenant Sippe sighted Lake Constance, and taking advantage of the mist lying low upon the water, descended to such an extent that he found himself only a few feet above the roofs of the houses. Swinging round to the Lake he descended still lower until at last he was practically skimming the surface of the Lake, since he flew at the amazingly low height of barely seven feet off the water. There is no doubt that the noise of his motor was heard plainly by the enemy, but the mist completely enveloped him, and owing to the strange pranks that fog plays with sound deceived his antagonists. At last, climbing above the bank of vapour, he found that he had overshot the mark, so he turned quickly and sped backwards. At the same time he discovered that he had been preceded by Commander Briggs, who was bombarding the shed furiously, and who himself was the object of a concentrated fire. Swooping down once more, Lieutenant Sippe turned, rained his bombs upon the objective beneath, drawing fire upon himself, but co-operating with Commander Babington, who had now reached the scene, he manoeuvred above the works and continued the bombardment until their ammunition was expended, when they sped home-wards under the cover of the mist. Considering the intensity of the hostile fire, it is surprising that the aeroplanes were not smashed to fragments. Undoubtedly the high speed of the machines and the zigzagging courses which were followed nonplussed the enemy. Commander Briggs was not so fortunate as his colleagues; a bullet pierced his petrol tank, compelling a hurried descent. The most amazing feature of these aerial raids has been the remarkably low height at which the airmen have ventured to fly. While such a procedure facilitates marksmanship it increases the hazards. The airmen have to trust implicitly to the fleetness of their craft and to their own nerve. Bearing in mind the vulnerability of the average aeroplane, and the general absence of protective armouring against rifle fire at almost point-blank range, it shows the important part which the human element is compelled to play in bomb-dropping operations. Another missile which has been introduced by the French airmen, and which is extremely deadly when hurled against dense masses of men, is the steel arrow, or "flechette" as it is called. It is a fiendish projectile consisting in reality of a pencil of solid polished steel, 4 3/4 inches in length. The lower end has a sharp tapering point, 5/8ths of an inch in length. For a distance of 1 1/8th of an inch above this point the cylindrical form of the pencil is preserved, but for the succeeding three inches to the upper end, the pencil is provided with four equally spaced angle flanges or vanes. This flanging of the upper end or tail ensures the arrow spinning rapidly as it falls through the air, and at the same times preserves its vertical position during its descent. The weight of the arrow is two-thirds of an ounce. The method of launching this fearsome projectile is ingenious. A hundred or even more are packed in a vertical position in a special receptacle, placed upon the floor of the aeroplane, preferably near the foot of the pilot or observer. This receptacle is fitted with a bottom moving in the manner of a trap-door, and is opened by pressing a lever. The aviator has merely to depress this pedal with his foot, when the box is opened and the whole of the contents are released. The fall at first is somewhat erratic, but this is an advantage, as it enables the darts to scatter and to cover a wide area. As the rotary motion of the arrows increases during the fall, the direct line of flight becomes more pronounced until at last they assume a vertical direction free from all wobbling, so that when they alight upon the target they are quite plumb. When launched from a height they strike the objective with terrific force, and will readily penetrate a soldier's helmet and skull. Indeed, when released at a height of 4,000 feet they have been known to pierce a mounted soldier's head, and pass vertically through his body and that of his horse also. Time after time German soldiers have found themselves pinned to the ground through the arrow striking and penetrating their feet. Owing to the extremely light weight of the darts they can be launched in batches of hundreds at a time, and in a promiscuous manner when the objective is a massed body of infantry or cavalry, or a transport convoy. They are extremely effective when thrown among horses even from a comparatively low altitude, not so much from the fatalities they produce, as from the fact that they precipitate a stampede among the animals, which is generally sufficiently serious and frantic to throw cavalry or a transport-train into wild confusion. Although aerial craft, when skilfully handled, have proved highly successful as weapons of offence, the possibilities of such aggression as yet are scarcely realised; aerial tactics are in their infancy. Developments are moving rapidly. Great efforts are being centred upon the evolution of more formidable missiles to be launched from the clouds. The airman is destined to inspire far greater awe than at present, to exercise a still more demoralising influence, and to work infinitely more destruction. CHAPTER XI. ARMOURED AEROPLANES The stern test of war has served to reveal conclusively the fact that aerial craft can be put out of action readily and effectively, when once the marksman has picked up the range, whether the gunner be conducting his operations with an anti-aircraft gun stationed upon the ground, or from a hostile machine. It will be remembered that Flight-Commander Briggs, on the occasion of the daring British raid upon the Zeppelin sheds at Friedrichshafen, was brought to the ground by a bullet which penetrated his fuel tank. Several other vessels, British, German, French, and Russian alike, have been thrown out of action in a similar manner, and invariably the craft which has been disabled suddenly in this way has fallen precipitately to earth in the fatal headlong dive. Previous to the outbreak of hostilities there was considerable divergence of opinion upon this subject. The general opinion was that the outspread wings and the stays which constituted the weakest parts of the structure were most susceptible to gun-fire, and thus were likely to fail. But practice has proved that it is the driving mechanism which is the most vulnerable part of the aeroplane. This vulnerability of the essential feature of the flying machine is a decisive weakness, and exposes the aviator to a constant menace. It may be quite true that less than one bullet in a thousand may hit the machine, but when the lucky missile does find its billet its effect is complete. The fact must not be overlooked that the gunners who work the batteries of anti-aircraft guns are becoming more and more expert as a result of practice, so that as time progresses and improved guns for such duty are rendered available, the work of the aviator is likely to become more dangerous and difficult. Experience has proved that the high velocity gun of to-day is able to hurl its projectile or shell to an extreme height--far greater than was previously considered possible--so that considerable discretion has to be exercised by the airman, who literally bears his life in his hands. Although elaborate trials were carried out upon the testing ranges with the weapons devised especially for firing upon flying machines, captive balloons being employed as targets, the data thus obtained were neither conclusive nor illuminating. The actual experiences of airmen have given us some very instructive facts upon this point for the first time. It was formerly held that the zone of fire that is to be considered as a serious danger was within a height of about 4,500 feet. But this estimate was well within the mark. Airmen have found that the modern projectiles devised for this phase of operations are able to inflict distinctly serious damage at an altitude of 9,000 feet. The shell itself may have but little of its imparted velocity remaining at this altitude, but it must be remembered that when the missile bursts, the contents thereof are given an independent velocity, and a wide cone of dispersion, which is quite sufficient to achieve the desired end, inasmuch as the mechanism of the modern aeroplane and dirigible is somewhat delicate. It was for this reason that the possibility of armouring the airship was discussed seriously, and many interesting experiments in this field were carried out. At the same time it was decided that the armouring should be effected upon lines analogous to that prevailing in warship engineering. The craft should not only be provided with defensive but also with aggressive armament. This decision was not viewed with general approbation. It was pointed out that questions of weight would arise, especially in relation to the speed of the machine. Increased weight, unless it were accompanied by a proportionate augmentation of power in the motor, would react against the efficiency and utility of the machine, would appreciably reduce its speed, and would affect its climbing powers very adversely. In some quarters it was maintained that as a result the machine would even prove unsuited to military operations, inasmuch as high speed is the primary factor in these. Consequently it was decided by the foremost aviating experts that machines would have to be classified and allotted to particular spheres of work, just as warships are built in accordance with the special duty which they are expected to perform. In reconnaissance, speed is imperative, because such work in the air coincides with that of the torpedo-boat or scout upon the seas. It is designed to acquire information respecting the movements of the enemy, so as to assist the heavier arms in the plan of campaign. On the other hand, the fighting corsair of the skies might be likened to the cruiser or battleship. It need not possess such a high turn of speed, but must be equipped with hard-hitting powers and be protected against attacking fire. One attempt to secure the adequate protection against gun-fire from the ground assumed the installation of bullet-proof steel plating, about one fifth of an inch thick, below the tank and the motor respectively. The disposition of the plating was such as to offer the minimum of resistance to the air and yet to present a plane surface to the ground below. So far as it went this protection was completely effective, but it failed to armour the vital parts against lateral, cross and downward fire while aloft. As the latter is more to be feared than the fire from the ground, seeing that it may be directed at point blank range, this was a decided defect and the armour was subsequently abandoned as useless. The only effective method of achieving the desired end is to armour the whole of the carriage or fuselage of the adroplane, and this was the principle adopted by the Vickers Company. The Vickers military aeroplane is essentially a military machine. It is built of steel throughout. The skeleton of the machine is formed of an alloy which combines the qualities of aluminium and steel to ensure toughness, strength, and lightness. In fact, metal is employed liberally throughout, except in connection with the wings, which follow the usual lines of construction. The body of the car is sheathed with steel plating which is bullet proof against rifle or even shrapnel fire. The car is designed to carry two persons; the seats are therefore disposed tandem-wise, with the observer or gunner occupying the front seat. The defensive armament is adequate for ordinary purposes. Being fitted with a 100 horse-power motor, fairly high speeds are attainable, although the velocity is not equal to that of machines constructed upon conventional lines, inasmuch as there is an appreciable increase in weight. The car is short and designed upon excellent stream lines, so that the minimum of resistance to the air is offered, while at the same time the balancing is perfect. The sides of the car are brought up high enough to protect the aviators, only their heads being visible when they are seated. The prow of the car follows the lines generally adopted in high speed torpedo boat design; there is a sharp knife edge stem with an enclosed fo'c's'le, the latter housing the gun. Another craft, designed for scouting operations, may be likened to the mosquito craft of the seas. This machine, while a biplane like the military aeroplane, is of lighter construction, everything being sacrificed to speed in this instance. It is fitted with a 100 horse-power motor and is designed to carry an observer if required. There is no offensive armament, however. The fuel tank capacity, moreover, is limited, being only sufficient for a two or three hours' flight. While this is adequate for general reconnoitring, which for the most part entails short high speed flights, there are occasions when the Staff demands more prolonged observations conducted over a greater radius. This requisition can be met by eliminating the observer, whose duties in this instance must be assumed by the pilot, and substituting in place of the former, a second fuel tank of sufficient capacity for a flight of four or five hours, thereby bringing the term of action in the air to about 6 1/4 hours. This machine travels at a very high speed and is eminently adapted to its specific duty, but it is of limited service for general purposes. The arming of an aeroplane, to enable it to defend itself against hostile attack or to participate in raiding operations upon the aerial fleet of the enemy, appears to be a simple task, but as a matter of fact it is an undertaking beset with difficulties innumerable. This is especially the case where the aeroplane is of the tractive type, that is to say where the propellers are placed in the forefront of the machine and in their revolution serve to draw the machine forward. All other considerations must necessarily be sacrificed to the mounting of the propeller. Consequently it is by no means easy to allot a position for the installation of a gun, or if such should be found there is grave risk of the angle of fire being severely restricted. In fact, in many instances the mounting of a gun is out of the question: it becomes a greater menace to the machine than to the enemy. The French aeronautical section of the military department devoted considerable study to this subject, but found the problem almost insurmount able. Monsieur Loiseau met with the greatest measure of success, and his system is being practised in the present campaign. This principle is essentially adapted to tractor aeroplanes. Forward of the pilot a special position is reserved for the gunner. A special mounting is provided towards the prow, and upon the upper face of the body of the machine. The gun mounting is disposed in such a manner that it is able to command a wide arc of fire in the vertical plane over the nose of the machine and more particularly in the downward direction. The marksman is provided with a special seat, but when he comes into action he has to stand to manipulate his weapon. The lower part of his body is protected by a front shield of steel plate, a fifth of an inch in thickness, while a light railing extending upon either side and behind enables the gunner to maintain his position when the aeroplane is banking and climbing. The machine gun, of the Hotchkiss type, is mounted upon a swivel attached to a tripod, while the latter is built into the bracing of the car, so as to ensure a fairly steady gun platform. While the gun in the hands of a trained marksman may be manipulated with destructive effect, the drawbacks to the arrangement are obvious. The gunner occupies a very exposed position, and, although the bullet-proof shield serves to break the effects of wind when travelling at high speed which renders the sighting and training of the weapon extremely difficult, yet he offers a conspicuous target, more particularly when the enemy is able to assume the upper position in the air as a result of superior speed in travelling. The gun, however, may be elevated to about 60 degrees, which elevation may be accentuated by the inclination of the aeroplane when climbing, while the facility with which the weapon may be moved through the horizontal plane is distinctly favourable. But the aerial marksman suffers from one very pronounced defect: he has a severely restricted survey of everything below, since his vision is interrupted by the planes. The result is that an enemy who has lost ascendancy of position is comparatively safe if he is able to fly immediately below his adversary: the mitrailleuse of the latter cannot be trained upon him. On the other hand the enemy, if equipped with repeating rifles or automatic pistols, is able to inflict appreciable damage upon the craft overhead, the difficulties of firing vertically into the air notwithstanding. In the Vickers system, where the propeller is mounted behind the car, the aeroplane thus operating upon the pusher principle, the nose of the car is occupied by the arm, which is a rifle calibre machine gun fitted upon a special mounting. The prow is provided with an embrasure for the weapon and the latter is so installed as to command an angle of 30 degrees on all sides of the longitudinal axis of the machine when in flight. In this instance the marksman is provided with complete protection on all sides, inasmuch as his position is in the prow, where the hood of the fo'c's'le shields him from overhead attack. The gun is protected by a special shield which moves with the gun barrel. This shield is provided with mica windows, through which the gunner is able to sight his arm, so that he is not inconvenienced in any way by the wind draught. One shortcoming of such methods of arming an aeroplane will be observed. Ahead firing only is possible; the weapon cannot be trained astern, while similarly the line of fire on either broadside is severely limited. This is one reason why the machine-gun armament of aerial craft of the heavier-than-air type has not undergone extensive development. In many instances the pilot and observer have expressed their preference for repeating high velocity rifles over any form of fixed gun mounting, and have recourse to the latter only when the conditions are extremely favourable to its effective employment. Efforts are now being made to equip the military type of aeroplane with both forward and astern firing guns. The urgency of astern fire has been brought home very vividly. Suppose, for instance, two hostile aeroplanes, A and B, are in the air. A has the advantage at first, but B is speedier and rapidly overhauls A. During the whole period of the overhauling movement the gun of B can be directed upon A, while the latter, owing to the arc of training being limited to c d cannot reply. Obviously in the running fight it would be to the advantage of B, although the fleeter machine, to keep behind A (position 1), but the latter is making towards its own lines. Under these circumstances A must be headed off, so B crowds on speed to consummate this end. But in the overtaking process B renders his gun-fire ineffective, inasmuch as B passes beyond the arc of his gun which is represented by e f. But in so doing B comes within the firing arc of A (position 9). To minimise this danger B ascends to a higher level to obtain the paramount position. If, however, B were equipped with an astern gun the aeroplane A would be within the fire of B when the forward gun of the latter could not be used. Similarly if A were also fitted with an astern gun it would be able to attack its pursuer the whole time B was to its rear and in this event, if its gun-fire were superior, it would be able to keep the latter to a safe distance, or compel B to manoeuvre into a superior position, which would entail a certain loss of time. An astern firing gun would be valuable to B in another sense. Directly it had passed A or brought the latter within the zone of its astern gun it could maintain its fire at the most advantageous range, because owing to its speed it would be able to dictate the distance over which shots should be exchanged and if mounted with a superior weapon would be able to keep beyond the range of A's guns while at the same time it would keep A within range of its own gun and consequently rake the latter. In the interests of self-preservation A would be compelled to change its course; in fact, B would be able to drive it in any direction he desired, as he would command A's movements by gun-fire. The value of combined ahead and astern firing has been appreciated, but there is one difficulty which at the moment appears to be insuperable the clearance of the propeller. At the moment astern-firing, if such it may be called, is maintained by repeating rifles, but this armament is not to be compared with machine-gun firing, as the latter with its capacity to pour 400 to 600 shots a minute, is far more deadly, particularly when the weapon is manipulated by a crack gunner. Up to the present the offensive armament of aeroplanes has been confined to light machine guns such as the Hotchkiss, Berthier, Schwartlose, and Maxim weapons. So far as the arming of aeroplanes is concerned the indispensable condition is light weight. With airships this factor is not so vital, the result being that some dirigibles are mounted with guns, throwing one pound bursting shells, fitted either with delay action or percussion fuses, the former for preference. These shells are given a wide cone of dispersion. Experiments are also being made with a gun similar to the pom-pom which proved so useful in South Africa, the gun throwing small shells varying from four to eight ounces in weight at high velocity and in rapid succession. While such missiles would not be likely to inflict appreciable damage upon an armoured aeroplane, they would nevertheless be disconcerting to the aviators subjected to such fire, and in aerial combats the successful undermining of the adversary's moral is of far greater importance than in land operations, since immediately ascendancy in the artillery operations is attained the final issue is a matter of moments. But the most devastating arm which has yet been contrived for aerial operations is the light machine gun which has recently been perfected. The one objective with this weapon is to disable the hostile aircraft's machinery. It fires an armour piercing projectile which, striking the motor of any aircraft, would instantly put the latter out of action. The shell has a diameter of about.75 inch and weighs about four ounces. The gun is a hybrid of the mitrailleuse and the French "Soixante-quinze," combining the firing rapidity of the former with the recoil mechanism of the latter. This missile has established its ability to penetrate the defensive armouring of any aeroplane and the motor of the machine at 1,000 yards' range. This offensive arm is now being manufactured, so that it is likely to be seen in the near future as the main armament of aeroplanes. At the moment widespread efforts are being made in the direction of increasing the offensive efficiency of aircraft. It is one of the phases of ingenuity which has been stimulated into activity as a result of the war. CHAPTER XII. BATTLES IN THE AIR Ever since the days of Jules Verne no theme has proved so popular in fiction as fighting in the air. It was a subject which lent itself to vivid imagination and spirited picturesque portrayal. Discussion might be provoked, but it inevitably proved abortive, inasmuch as there was a complete absence of data based upon actual experience. The novelist was without any theory: he avowedly depended upon the brilliance of his imagination. The critic could only theorise, and no matter how dogmatic his reasonings, they were certainly as unconvincing as those of the object of his attack. But truth has proved stranger than fiction. The imaginative pictures of the novelist have not only been fulfilled but surpassed, while the theorising critic has been utterly confounded. Fighting in the air has become so inseparable from the military operations of to-day that it occurs with startling frequency. A contest between hostile aeroplanes, hundreds of feet above the earth, is no longer regarded as a dramatic, thrilling spectacle: it has become as matter-of-fact as a bayonet melee between opposed forces of infantry. A duel in the clouds differs from any other form of encounter. It is fought mercilessly: there can be no question of quarter or surrender. The white flag is no protection, for the simple reason that science and mechanical ingenuity have failed, so far, to devise a means of taking an aeroplane in tow. The victor has no possible method of forcing the vanquished to the ground in his own territory except driving. If such a move be made there is the risk that the latter will take the advantage of a critical opportunity to effect his escape, or to turn the tables. For these reasons the fight is fought to a conclusive finish. To aspire to success in these combats waged in the trackless blue, speed, initiative, and daring are essential. Success falls to the swift in every instance. An aeroplane travelling at a high speed, and pursuing an undulating or irregular trajectory is almost impossible to hit from the ground, as sighting is so extremely difficult. Sighting from another machine, which likewise is travelling rapidly, and pursuing an irregular path, is far more so. Unless the attacker can approach relatively closely to his enemy the possibility of hitting him is extremely remote. Rifle or gun-fire must be absolutely point blank. When a marauding aeroplane is espied the attacking corsair immediately struggles for the strategical position, which is above his adversary. To fire upwards from one aeroplane at another is virtually impossible, at least with any degree of accuracy. The marksman is at a hopeless disadvantage. If the pilot be unaccompanied and entirely dependent upon his own resources he cannot hope to fire vertically above him, for the simple reason that in so doing he must relinquish control of his machine. A rifle cannot possibly be sighted under such conditions, inasmuch as it demands that the rifleman shall lean back so as to obtain control of his weapon and to bring it to bear upon his objective. Even if a long range Mauser or other automatic pistol of the latest type be employed, two hands are necessary for firing purposes, more particularly as, under such conditions, the machine, if not kept under control, is apt to lurch and pitch disconcertingly. Even a colleague carried for the express purpose of aggression is handicapped. If he has a machinegun, such as a Maxim or a mitrailleuse, it is almost out of the question to train it vertically. Its useful vertical training arc is probably limited to about 80 degrees, and at this elevation the gunner has to assume an extremely uncomfortable position, especially upon an aeroplane, where, under the best of circumstances, he is somewhat cramped. On the other hand the man in the aeroplane above holds the dominating position. He is immediately above his adversary and firing may be carried out with facility. The conditions are wholly in his favour. Sighting and firing downwards, even if absolutely vertically, imposes the minimum physical effort, with the result that the marksman is able to bring a steadier aim upon his adversary. Even if the machine be carrying only the pilot, the latter is able to fire upon his enemy without necessarily releasing control of his motor, even for a moment. If he is a skilled sharpshooter, and the exigencies demand, he can level, sight, and fire his weapon with one hand, while under such circumstances an automatic self-loading pistol can be trained upon the objective with the greatest ease. If the warplane be carrying a second person, acting as a gunner, the latter can maintain an effective rifle fusillade, and, at the same time, manipulate his machine-gun with no great effort, maintaining rifle fire until the pilot, by manoeuvring, can enable the mitrailleuse or Maxim to be used to the greatest advantage. Hence the wonderful display of tactical operations when two hostile aeroplanes sight one another. The hunted at first endeavours to learn the turn of speed which his antagonist commands. If the latter is inferior, the pursued can either profit from his advantage and race away to safety, or at once begin to manoeuvre for position. If he is made of stern stuff, he attempts the latter feat without delay. The pursuer, if he realises that he is out classed in pace, divines that his quarry will start climbing if he intends to show fight, so he begins to climb also. Now success in this tactical move will accrue to the machine which possesses the finest climbing powers, and here again, of course, speed is certain to count. But, on the other hand, the prowess of the aviator--the human element once more--must not be ignored. The war has demonstrated very convincingly that the personal quality of the aviator often becomes the decisive factor. A spirited contest in the air is one of the grimmest and most thrilling spectacles possible to conceive, and it displays the skill of the aviator in a striking manner. Daring sweeps, startling wheels, breathless vol-planes, and remarkable climbs are carried out. One wonders how the machine can possibly withstand the racking strains to which it is subjected. The average aeroplane demands space in which to describe a turn, and the wheel has to be manipulated carefully and dexterously, an operation requiring considerable judgment on the part of the helmsman. But in an aerial duel discretion is flung to the winds. The pilot jambs his helm over in his keen struggle to gain the superior position, causing the machine to groan and almost to heel over. The stem stresses of war have served to reveal the perfection of the modern aeroplane together with the remarkable strength of its construction. In one or two instances, when a victor has come to earth, subsequent examination has revealed the enormous strains to which the aeroplane has been subjected. The machine has been distorted; wires have been broken--wires which have succumbed to the enormous stresses which have been imposed and have not been snapped by rifle fire. One well-known British airman, who was formerly a daring automobilist, confided to me that a fight in the air "is the finest reliability trial for an aeroplane that was ever devised!" In these desperate struggles for aerial supremacy the one party endeavours to bring his opponent well within the point-blank range of his armament: the other on his part strives just as valiantly to keep well out of reach. The latter knows fully well that his opponent is at a serious disadvantage when beyond point-blank range, for the simple reason that in sighting the rifle or automatic pistol, it is difficult, if not impossible while aloft, to judge distances accurately, and to make the correct allowances for windage. If, however, the dominating aviator is armed with a machine gun he occupies the superior position, because he can pour a steady hail of lead upon his enemy. The employment of such a weapon when the contest is being waged over friendly territory has many drawbacks. Damage is likely to be inflicted among innocent observers on the earth below; the airman is likely to bombard his friends. For this very reason promiscuous firing, in the hope of a lucky shot finding a billet in the hostile machine, is not practised. Both parties appear to reserve their fire until they have drawn within what may be described as fighting distance, otherwise point blank range, which may be anything up to 300 yards. Some of the battles between the German and the French or British aeroplanes have been waged with a total disregard of the consequences. Both realise that one or the other must perish, and each is equally determined to triumph. It is doubtful whether the animosity between the opposing forces is manifested anywhere so acutely as in the air. In some instances the combat has commenced at 300 feet or so above the earth, and has been fought so desperately, the machines climbing and endeavouring to outmanoeuvre each other, that an altitude of over 5,000 feet has been attained before they have come to close grips. The French aviator is nimble, and impetuous: the German aviator is daring, but slow in thought: the British airman is a master of strategy, quick in thought, and prepared to risk anything to achieve his end. The German airman is sent aloft to reconnoitre the enemy and to communicate his information to his headquarters. That is his assigned duty and he performs it mechanically, declining to fight, as the welfare of his colleagues below is considered to be of more vital importance than his personal superiority in an aerial contest. But if he is cornered he fights with a terrible and fatalistic desperation. The bravery of the German airmen is appreciated by the Allies. The French flying-man, with his traditional love for individual combat, seeks and keenly enjoys a duel. The British airman regards such a contest as a mere incident in the round of duty, but willingly accepts the challenge when it is offered. It is this manifestation of what may be described as acquiescence in any development that enabled the British flying corps, although numerically inferior, to gain its mastery of the air so unostentatiously and yet so completely. All things considered an aeroplane duel is regarded as a fairly equal combat. But what of a duel between an aeroplane and a dirigible? Which holds the advantage? This question has not been settled, at any rate conclusively, but it is generally conceded that up to a certain point the dirigible is superior. It certainly offers a huge and attractive target, but rifle fire at its prominent gas-bag is not going to cause much havoc. The punctures of the envelope may represent so many vents through which the gas within may effect a gradual escape, but considerable time must elapse before the effect of such a bombardment becomes pronounced in its result, unless the gas-bag is absolutely riddled with machine gun-fire, when descent must be accelerated. On the other hand, it is to be presumed that the dirigible is armed. In this event it has a distinct advantage. It has a steady gun-platform enabling the weapons of offence to be trained more easily and an enhanced accuracy of fire to be obtained. In order to achieve success it is practically imperative that an aeroplane should obtain a position above the dirigible, but the latter can ascend in a much shorter space of time, because its ascent is vertical, whereas the aeroplane must describe a spiral in climbing. Under these circumstances it is relatively easy for the airship to outmanoeuvre the aeroplane in the vertical plane, and to hold the dominating position. But even should the aeroplane obtain the upper position it is not regarded with fear. Some of the latest Zeppelins have a machine gun mounted upon the upper surface of the envelope, which can be trained through 360 degrees and elevated to about 80 degrees vertical. Owing to the steady gun platform offered it holds command in gun-fire, so that the aeroplane, unless the aviator is exceptionally daring, will not venture within the range of the dirigible. It is stated, however, that this upper gun has proved unsatisfactory, owing to the stresses and strains imposed upon the framework of the envelope of the Zeppelin during firing, and it has apparently been abandoned. The position, however, is still available for a sniper or sharpshooter. The position in the sky between two such combatants is closely analogous to that of a torpedo boat and a Dreadnought. The latter, so long as it can keep the former at arm's, or rather gun's, distance is perfectly safe. The torpedo boat can only aspire to harass its enemy by buzzing around, hoping that a lucky opportunity will develop to enable it to rush in and to launch its torpedo. It is the same with the aeroplane when arrayed against a Zeppelin. It is the mosquito craft of the air. How then can a heavier-than-air machine triumph over the unwieldy lighter-than-air antagonist? Two solutions are available. If it can get above the dirigible the adroplane may bring about the dirigible's destruction by the successful launch of a bomb. The detonation of the latter would fire the hydrogen within the gas-bag or bags, in which event the airship would fall to earth a tangled wreck. Even if the airship were inflated with a non-inflammable gas--the Germans claim that their Zeppelins now are so inflated--the damage wrought by the bomb would be so severe as to destroy the airship's buoyancy, and it would be forced to the ground. The alternative is very much more desperate. It involves ramming the dirigible. This is undoubtedly possible owing to the speed and facile control of the aeroplane, but whether the operation would be successful remains to be proved. The aeroplane would be faced with such a concentrated hostile fire as to menace its own existence--its forward rush would be frustrated by the dirigible just as a naval vessel parries the ramming tactics of an enemy by sinking the latter before she reaches her target, while if it did crash into the hull of the dirigible, tearing it to shreds, firing its gas, or destroying its equilibrium, both protagonists would perish in the fatal dive to earth. For this reason ramming in mid-air is not likely to be essayed except when the situation is desperate. What happens when two aeroplanes meet in dire combat in mid-air and one is vanquished? Does the unfortunate vessel drop to earth like a stone, or does it descend steadily and reach the ground uninjured? So far as actual experience has proved, either one of the foregoing contingencies may happen. In one such duel the German aeroplane was observed to start suddenly upon a vol-plane to the ground. Its descending flight carried it beyond the lines of the Allies into the territory of its friends. Both came to the conclusion that the aviator had effected his escape. But subsequent investigation revealed the fact that a lucky bullet from the Allies' aeroplane had lodged in the brain of the German pilot, killing him instantly. At the moment when Death over took him the aviator had set his plane for the descent to the ground, and the machine came to earth in the manner of a glider. But in other instances the descent has been far more tragic. The aeroplane, deprived of its motive power, has taken the deadly headlong dive to earth. It has struck the ground with terrific violence, burying its nose in the soil, showing incidentally that a flying machine is an indifferent plough, and has shattered itself, the debris soaked with the escaping fuel becoming ignited. In any event, after such a fall the machine is certain to be a wreck. The motor may escape damage, in which event it is salvaged, the machine subsequently being purposely sacrificed to the flames, thereby rendering it no longer available to the enemy even if captured. In many instances the hostile fire has smashed some of the stays and wires, causing the aeroplane to lose its equilibrium, and sending it to earth in the manner of the proverbial stone, the aviators either being dashed to pieces or burned to death. What are the vulnerable parts of the aeroplane? While the deliberate intention of either combatant is to put his antagonist hors de combat, the disablement of the machine may be achieved without necessarily killing or even seriously wounding the hostile airman. The prevailing type of aeroplane is highly susceptible to derangement: it is like a ship without armour plate protection. The objective of the antagonist is the motor or the fuel-tank, the vital parts of the machine, as much as the aviator seated within. A well-planted shot, which upsets the mechanism of the engine, or a missile which perforates the fuel tank, thereby depriving the motor of its sustenance, will ensure victory as conclusively as the death of the aviator himself. Rifle fire can achieve either of these ends with little difficulty. Apart from these two nerve-centres, bombardment is not likely to effect the desired disablement, inasmuch as it cannot be rendered completely effective. The wings may be riddled like a sieve, but the equilibrium of the machine is not seriously imperilled thereby. Even many of the stays may be shot away, but bearing in mind the slender objective they offer, their destruction is likely to be due more to luck than judgment. On the other hand, the motor and fuel tank of the conventional machine offer attractive targets: both may be put out of action readily, and the disablement of the motive power of an enemy's craft, be it torpedo-boat, battleship, or aeroplane, immediately places the same at the assailant's mercy. Nevertheless, of course, the disablement of the airman brings about the desired end very effectively. It deprives the driving force of its controlling hand; The aeroplane becomes like a ship without a rudder: a vessel whose helmsman has been shot down. It is unmanageable, and likely to become the sport of the element in which it moves. It is for this reason that aviators have been urged to direct their fire upon the men and mechanism of a dirigible in the effort to put it out of action. An uncontrolled airship is more likely to meet with its doom than an aeroplane. The latter will inevitably glide to earth, possibly damaging itself seriously in the process, as events in the war have demonstrated, but a helpless airship at once becomes the sport of the wind, and anyone who has assisted, like myself, in the descent of a vessel charged with gas and floating in the air, can appreciate the difficulties experienced in landing. An uncontrolled Zeppelin, for instance, would inevitably pile up in a tangled twisted ruin if forced to descend in the manner of an ordinary balloon. Consequently the pilot of a dirigible realises to the full the imperative urgency of keeping beyond the point-blank fire of aerial mosquito craft. The assiduity with which British aviators are prepared to swarm to the attack has been responsible for a display of commendable ingenuity on the part of the German airman. Nature has provided some of its creatures, such as the octopus, for instance, with the ways and means of baffling its pursuers. It emits dense clouds of inky fluid when disturbed, and is able to effect its escape under cover of this screen. The German aviator has emulated the octopus. He carries not only explosive bombs but smoke balls as well. When he is pursued and he finds himself in danger of being overtaken, the Teuton aviator ignites these missiles and throws them overboard. The aeroplane becomes enveloped in a cloud of thick impenetrable smoke. It is useless to fire haphazard at the cloud, inasmuch as it does not necessarily cover the aviator. He probably has dashed out of the cloud in such a way as to put the screen between himself and his pursuer. In such tactics he has merely profited by a method which is practised freely upon the water. The torpedo boat flotilla when in danger of being overwhelmed by superior forces will throw off copious clouds of smoke. Under this cover it is able to steal away, trusting to the speed of the craft to carry them well beyond gunshot. The "smoke screen," as it is called, is an accepted and extensively practised ruse in naval strategy, and is now adopted by its mosquito colleagues of the air. CHAPTER XIII. TRICKS AND RUSES TO BAFFLE THE AIRMAN The airman has not been allowed to hold his undisputed sway in military operations for long. Desperate situations demand drastic remedies and already considerable and illuminating ingenuity is being displayed to baffle and mislead the scout of the skies. It is a somewhat curious and noteworthy fact, that the Germans were among the first to realise the scope of the airman's activities, and the significance of their relation to the conveyance of intimate information and the direction of artillery fire. Consequently, they now spare no effort to convey illusory information, in the hope that the hostile force may ultimately make a false move which may culminate in disaster. Thus, for instance, as much endeavour is bestowed upon the fashioning of dummy trenches as upon the preparation of the actual lines of defence. And every care will be taken to indicate that the former are strongly held. The dug-outs are complete and at places are apparently cunningly masked. If the airman is flying swiftly, he is likely to fail to distinguish the dummy from the real trenches. To him the defences appear to be far more elaborate and more strongly held than is the actual case. The advantage of this delusion is obvious when a retreat is being made. It enables the enemy to withdraw his forces deliberately and in perfect order, and to assume another and stronger position comparatively at leisure. The difficulty of detecting the dummies is emphasised, inasmuch as now, whenever the sound of an aeroplane is heard, or a glimpse thereof is obtained, the men keep well down and out of sight. Not a sign of movement is observable. For all the airman may know to the contrary, the trenches may be completely empty, whereas, as a matter of fact, they are throbbing with alert infantry, anxious for a struggle with the enemy. This is one instance where the dirigible is superior to the aeroplane. The latter can only keep circling round and round over the suspicious position; the movement through the air interferes with close continuous observation. On the other hand, the dirigible can maintain a stationary position aloft for hours on end. Then the issue is resolved into a contest of patience, with the advantage to the airman. The soldiers in the trenches fret and fume under cover; confined concealment is irksome and is a supreme test of the nerves. Unless the soldiers are made of very stern stuff, physical endurance succumbs. Some rash act--apparently very trivial--may be committed; it suffices for the vigilant sentinel overhead. He detects the slender sign of life, forms his own conclusions, and returns to his headquarters with the intelligence that the enemy is playing "Brer Rabbit." It has also become increasingly difficult for the airman to gather absolutely trustworthy data concerning the disposition and movement of troops. Small columns are now strung out along the highways to convey the impression that the moving troops are in far greater force than is actually the case, while the main body is under the cover offered by a friendly wood and is safe from detection. The rapidity with which thousands of men are able to disappear when the word "Airman" is passed round is astonishing. They vanish as completely and suddenly as if swallowed by the earth or dissolved into thin air. They conceal themselves under bushes, in ditches, lie prone under hedgerows, dart into houses and outbuildings--in short, take every cover which is available, no matter how slender it may seem, with baffling alacrity. The attenuated column, however, is kept moving along the highway for the express purpose of deceiving the airman. Advancing troops also are now urged to move forward under the shelter of trees, even if the task entails marching in single or double file, to escape the prying eyes of the man above. By keeping close to the line of trunks, thus taking full advantage of the overhanging branches, and marching in such a manner as to create little dust, it is possible to escape the aerial scout. The concealment of cavalry, however, is somewhat difficult. An animal, especially if he be unaccustomed to the noise of the aeroplane, is likely to become startled, and to give vent to a frightened and vociferous neighing which invariably provokes a hearty response from his equine comrades. The sharp ear of the airman does not fail to distinguish this sound above the music of his motor. Again, he has come to regard all copses and stretches of undergrowth with suspicion. Such may or may not harbour the enemy, but there is no risk in making an investigation. He swoops down, and when a short distance above the apparently innocent copse, circles round it two or three times. Still undecided, he finally hurls a bomb. Its detonation invariably proves effective. The horses stampede and the secret is out. Even foot soldiers must be severely trained and experienced to resist the natural inclination to break cover when such a missile is hurled into their midst. Frequently a force, which has laboured under the impression that it is safe from detection, has revealed its presence unwittingly and upon the spur of the moment. If the men be steeled against the bomb attack, it is almost impossible to resist the inclination to take a shot when the airman, swooping down, ventures so temptingly near as to render him an enticing target almost impossible to miss. As a rule, however, the observer is on the alert for such a betrayal of a force's existence. When the bomb fails to scatter the enemy, or the men are proof against the temptation to fire a volley, a few rounds from the aeroplane's machine gun often proves effective. If the copse indeed be empty no harm is done, beyond the abortive expenditure of a few rounds of ammunition: if it be occupied, the fruits of the manoeuvre are attractive. Cunning is matched against cunning, and the struggle for supremacy in the art of craftiness is keen. The French Flying Corps have had recourse to an ingenious ruse for accomplishing two ends--the one to draw concealed artillery fire, and the other to pre-occupy the airmen. Two German aerial scouts observed a French machine flying at a somewhat venturesome height over their masked artillery. Divining the reason for the hostile intrepidity they gave chase. Circling round the French machine they assailed it with machine-gun fire. The enemy appeared to take no notice but continued his gradual descent in a steady line. Presently the German airmen, having drawn sufficiently near, observed that the French aviator was inert. Had he been killed? Everything pointed to such a conclusion, especially as they had raked the aeroplane fore and aft with bullets. But still suspicious they continued their circling movements, their attention so concentrated upon their quarry that they had not observed another move. It was the crash of guns from their masked artillery which broke in upon their absorption. Looking round, they observed three French aeroplanes soaring around and above them at high speed. Scarcely had they realised the situation before a spirited mitraireuse fire was rained upon them. One of the German aeroplanes was speedily disabled. Its fuel tank was riddled and it sank rapidly, finally crashing to earth in the deadly dive head foremost, and killing both its occupants in the fall. The second aeroplane hurried away with its pilot wounded. In the excitement of the aerial melee the first French aeroplane had been forgotten. It was now scarcely 100 feet above the German artillery. A capture appeared to be imminent, but the Germans received a rude surprise. Suddenly the aeroplane exploded and a hail of shrapnel burst over the heads of the artillerymen. The circumstance was decidedly uncanny, but after two or three such experiences of exploding aeroplanes the matter was explained. The apparently helpless aeroplane was merely a glider, which, instead of carrying a man, had a booby-trap aboard. It appears that the French airmen have found a use for the aeroplanes which are considered unsafe for further use. The motor and propeller are removed and the dummy of explosives is strapped into position. The laden glider is then taken aloft by means of an airship, and in the concealment of the clouds is released, the rudder being so set as to ensure a gradual vol-plane towards the suspicious position below. The explosive cargo is set with a time fuse, the arrangement being that the contents will be detonated while the machine is near the ground, unless this end is accelerated by a well-planted shell from an anti-aircraft gun. The decoy glider is generally accompanied by one or two aeroplanes under control, which keep under the cover of the clouds until the hostile aviators have been drawn into the air, when they swoop down to the attack. The raiders are fully aware that they are not likely to become the target of fire from the ground, owing to the fact that the enemy's artillery might hit its friends. Consequently the antagonistic airmen are left to settle their own account. In the meantime the dummy machine draws nearer to the ground to explode and to scatter its death-dealing fragments of steel, iron, and bullets in all directions. Possibly in no other phase of warfare is subterfuge practised so extensively as in the concealment of guns. The branches of trees constitute the most complete protection and guns are placed in position beneath a liberal cover of this character. The branches also offer a screen for the artillerymen, who can lurk beneath this shelter until the aeroplane has passed. To complete the illusion dummy guns fashioned from tree trunks and the wheels of useless limbers are rigged up, and partially hidden under branches, the idea being to convey the impression to the man aloft that they are the actual artillery. The aerial scout observes the dummies beneath the sparse covering of branches. Congratulating himself upon his sharp eyesight, he returns to his base with the intelligence that he has found the enemy's guns he indicates their position upon the map, and in some cases returns to notify the position of the weapons by smoke-ball or tinsel, when they are immediately subjected to a severe bombardment. He follows the shell-fire and sees the arms put out of action. He returns to camp satisfied with his exploit, oblivious of the smiles and laughter of the hostile artillerymen, who have their guns safely in position and well masked some distance away. The dummies are imperfectly concealed purposely, so that they may be discovered by the aerial scout, while the real guns are completely masked and ready to belch forth from another point. In one or two cases the dummies have been rigged up in such a manner as to convey the impression, when seen from aloft, that a whole battery has been put out of action, barrels and wheels as well as broken limbers strewing the ground in all directions. Moving masses of soldiers are also resorting to cunning in order to mislead the airman or to escape his observation. At the battle of Haelen, during which engagement the German warplanes were exceptionally active, the Belgian soldiers covered their heads with bundles of wheat snatched from the standing stooks, and under this cover lurked in a field where the corn was still standing. From aloft their forms defied detection: the improvised headgear completely covered them and blended effectively with the surrounding wheat. In another instance the French misled a German airman somewhat effectively. What appeared to be cavalry was seen to be retreating along the country road, and the airman returned hurriedly to report. A German squadron was dispatched in hasty pursuit. But as it rounded a copse skirting the road it received a murderous fire at close quarters, which decimated the ranks and sent the survivors flying for their lives along the road up which they had ridden so confidently. Had the aviator been in a position to observe the horses more closely, he would have found that what appeared to be riders on their backs were in reality sacks stuffed with straw, dressed in old uniforms, and that a mere handful of men were driving the animals forward. The cavalrymen had purposely dismounted and secreted themselves in the wood in anticipation of such a pursuit as was made. While the Germans do not appear to be so enterprising in this form of ingenuity they have not been idle. A French airman flying over the Teuton lines observed the outermost trenches to be alive with men whose helmets were distinctly visible. The airman reported his observations and the trench was subjected to terrific shell fire. Subsequently the French made a spirited charge, but to their dismay found that the outermost German trench was occupied by dummies fashioned from all sorts of materials and crowned with helmets! This ruse had enabled the German lines to be withdrawn to another position in safety and comparatively at leisure. Before war was declared the German military experts were emphasising the importance of trees for masking troops and guns against aerial observation. One of the foremost authorities upon military aviation only a few months ago urged the German Military Staff to encourage the planting of orchards, not for the purpose of benefiting agriculture or in the interests of the farmers, but merely for military exigencies. He pointed to the extensive orchards which exist in Alsace-Lorraine and Baden, the military covering value of which he had determined from personal experience, having conducted aerial operations while military were moving to and fro under the cover of the trees. He declared that the cover was efficient and that under the circumstances the laying out of extensive orchards in strategical places should be carried out without any delay. This, he urged, was a national and not a private obligation. He advocated the bestowal of subsidies on the farmers to encourage the planting of fruit trees. He suggested that the trees should be provided by the State, and given to all who were prepared to plant them; that substantial prizes should be awarded to encourage the rapid growth thereof, and that annual prizes should be awarded to the man who would undertake their cultivation and pruning, not from the fruit-yielding point of view, but for facilitating the movement of troops beneath their dense branches. He even urged the military acquisition of suitable land and its determined, skilful, and discreet exploitation by those who loved the Fatherland. He emphasised the necessity for keeping such orchards under military control, only vouchsafing sufficient powers to the local authorities to ensure the desired consummation. He maintained that, if the work were prosecuted upon the right lines and sufficient financial assistance were given, the purpose in view could be achieved without saddling the war department with any unremunerative or excessive burden. He admitted that the process of raising fruit trees to the stage when they would afford adequate cover would be tedious and somewhat prolonged, but argued that the military advantages, such as enabling troops to move below the welcome shelter with absolute freedom and without physical fatigue, would be an ample compensation. The utility of such cover to artillery was another factor he did not fail to emphasise. He dwelt seriously upon the difficulty of rendering permanent gun emplacements and heavy artillery invisible to the airman by resort to the usual type of gun shields. The latter may be located with ease by alert airmen, whereas if the guns were under cover of fruit trees they would be able to accomplish their deadly mission without betraying their presence to the aerial scout. Moreover, by pruning the trees in such a manner as to ensure free movement beneath, the artillery would be able to advance without betraying the fact to the enemy. This authority vigorously insisted that the work should be carried out without a moment's delay as it was vital to the Fatherland. In the light of recent events, and the excellent cover which is offered by the orchards of the territory he cited as an illustration of his contention, such a disclosure is pregnant with meaning. It throws a new light upon the thorough methods with which the Germans carried out their military preparations, and incidentally shows that they were fully alive to every possible development. Fruit-raising as a complement to military operations may be a new line of discussion, but it serves to reveal the German in his true light, ready for every contingency, and shows how thoroughly he appreciates the danger from the man in the clouds. CHAPTER XIV. ANTI-AIRCRAFT GUNS. MOBILE WEAPONS. When the airship and the aeroplane became accepted units of warfare it was only natural that efforts should be concentrated upon the evolution of ways and means to compass their destruction or, at least, to restrict their field of activity. But aircraft appeared to have an immense advantage in combat. They possess virtually unlimited space in which to manoeuvre, and are able to select the elevation from which to hurl their missiles of destruction. There is another and even more important factor in their favour. A projectile fired, or even dropped, from a height, say of 5,000 feet, is favourably affected by the force of gravity, with the result that it travels towards the earth with accumulating energy and strikes the ground with decisive force. On the other hand, a missile discharged into space from a weapon on the earth has to combat this action of gravity, which exercises a powerful nullifying influence upon its flight and velocity, far in excess of the mere resistance offered by the air. In other words, whereas the projectile launched from aloft has the downward pull of the earth or gravitational force in its favour, the shell fired from the ground in the reverse direction has to contend against this downward pull and its decelerating effect. At the time when aircraft entered the realms of warfare very little was known concerning the altitudes to which projectiles could be hurled deliberately. Certain conclusive information upon this point was available in connection with heavy howitzer fire, based on calculations of the respective angles at which the projectile rose into the air and fell to the ground, and of the time the missile took to complete its flight from the gun to the objective. But howitzer fire against aircraft was a sheer impossibility: it was like using a six-inch gun to kill a fly on a window pane at a thousand yards' range. Some years ago certain experiments in aerial firing with a rifle were undertaken in Switzerland. The weapon was set vertically muzzle upwards and discharged. From the time which elapsed between the issue of the bullet from the muzzle until it struck the earth it was possible to make certain deductions, from which it was estimated that the bullet reached an altitude of 600 feet or so. But this was merely conjecture. Consequently when artillerists entered upon the study of fighting air-craft with small arms and light guns, they were compelled to struggle in the dark to a very pronounced extent, and this darkness was never satisfactorily dispelled until the present war, for the simple reason that there were no means of getting conclusive information. The German armament manufacturers endeavoured to solve the problem by using smoking shells or missiles fitted with what are known as tracers. By following the ascensional path of the projectiles as revealed by the smoke it was possible to draw certain conclusions. But these were by no means convincing or illuminating, as so many factors affected the issue. Despite the peculiar and complex difficulties associated with the problem it was attacked some what boldly. In this trying field of artillery research the prominent German armament manufacturers, Krupp of Essen and Ehrhardt of Dusseldorf, played a leading part, the result being that before the airship or the aeroplane was received within the military fold, the anti-aircraft gun had been brought into the field of applied science. The sudden levelling-up serves to illustrate the enterprise of the Germans in this respect as well as their perspicacity in connection with the military value of aircraft. Any gun we can hope to employ against aircraft with some degree of success must fulfil special conditions, for it has to deal with a difficult and elusive foe. Both the lighter-than-air and the heavier than-air craft possess distinctive features and varying degrees of mobility. Taking the first-named, the facility with which it can vary its altitude is a disconcerting factor, and is perplexing to the most skilful gunner, inasmuch as he is called upon to judge and change the range suddenly. On the other hand, the artilleryman is favoured in certain directions. The range of utility of the airship is severely limited. If its avowed mission is reconnaissance and conclusive information concerning the disposition of forces, artillery and so forth is required, experience has proved that such work cannot be carried out satisfactorily or with any degree of accuracy at a height exceeding 5,000 feet, and a distance beyond six miles. But even under these circumstances the climatic conditions must be extremely favourable. If the elements are unpropitious the airship must venture nearer to its objective. These data were not difficult to collect, inasmuch as they were more or less available from the results of military observations with captive balloons, the conditions being somewhat similar. With the ordinary captive balloon it has been found that, in clear weather, a radius of about 3 3/4 miles at the maximum elevation constitutes its range of reliable utility. With the aeroplane, however, the conditions are very dissimilar. In the first place the machine owing to its diminutive size as compared with the airship, offers a small and inconspicuous target. Then there is its high independent speed, which is far beyond that of the airship. Furthermore its mobility is greater. It can wheel, turn sharply to the right or to the left, and pursue an irregular undulating flight in the horizontal plane, which renders it well nigh impossible for a gunner to pick it up. The machine moves at a higher relative speed than that at which the gun can be trained. It is the rapid and devious variation which so baffles the gunner, who unless he be highly skilled and patient, is apt to commence to fire wildly after striving for a few moments, and in vain, to pick up the range; he trusts to luck or depends upon blind-shooting, which invariably results in a waste of ammunition. A gun, to be of tangible destructive efficiency when directed against aircraft, especially those depending upon the gas-bag for equilibrium, must be of special design. It must be capable of firing at an angle only a few degrees less than the absolute vertical, and in order to follow the rapid and involved movements of its objective, must be so mobile that it can be trained through a complete circle at any angle of inclination less than its maximum. At the same time, if the weapon is being used in field operations it must be mounted upon a carriage of adequate mobility to enable it to follow the airship, and thereby keep pace with the latter, so that the aerial craft may be sorely harassed if not actually hit. The automobile is the obvious vehicle for this duty, and it has accordingly been extensively used in this service. The automobile and the gun mounted thereon follow widely different lines. Some vehicles are designed especially for this duty, while others are improvisations, and be it noted, in passing, that many of the latter have proved more serviceable than the former. Still, the first-named is to be preferred, inasmuch as necessarily it is designed to meet the all-round requirements imposed, and consequently is better able to stand up to the intended work, whereas the extemporised vehicle is only serviceable under favourable conditions. The Krupp Company has evolved many designs of anti-aircraft motor-driven guns--"Archibalds" the British airmen term them with emphatic levity. They are sturdily-built vehicles fitted with heavy motors, developing from 40 to 50 horse-power, with the chassis not widely dissimilar from that adopted for motor-omnibus traffic. Consequently, they are not necessarily condemned to the high-roads, but within certain limits are able to travel across country, i.e., upon fields or other level expanses, where the soil is not unduly soft. But the very character of the problem rendered the evolution of the vehicle a somewhat perplexing matter. There were many factors which had to be taken into consideration, and it was possible to meet the imposed requirements only within certain limits. In the first place, the weight of the gun itself had to be kept down. It was obviously useless to overload the chassis. Again, the weight of the projectile and its velocity had to be borne in mind. A high velocity was imperative. Accordingly, an initial velocity varying from 2,200 to 2,700 feet per second, according to the calibre of the gun, was determined. Moreover, as mobility was an indispensable condition, the gun had to be so mounted that it could be fired from the motor-car even if the latter were travelling at high speed. This requirement entailed another difficulty. The gun had to be mounted in such a manner as to enable the gunner to train it easily and readily through the complete circle and through its complete range of vertical inclination. As the result of prolonged experiments it was ascertained that the most suitable arrangement was a pedestal mounting, either within a turret or upon an open deck. To meet the weight of the gun, as well as the strains and stresses incidental to firing, the chassis was strengthened, especially over the rear axle near which the mounting is placed. The heaviest gun of this type is the 10.5 centimetre (4 1/4-inch) quick-firer, throwing a shell weighing nearly forty pounds, with an initial velocity of 2,333 feet per second. This "Archibald" is totally unprotected. The gun is mounted centrally upon the carriage over the rear axle, and occupies the centre of the deck between the driver's seat and that of the gun crew behind. The whole of the deck is clear, thereby offering no obstruction to the gunner in training the weapon, while the space may be widened by dropping down the wings of the vehicle. At the rear is a seat to accommodate the gun crew, beneath which the ammunition is stowed. When travelling and out of action, the gun lies horizontally, the muzzle pointing from the rear of the car. To reduce the strains arising from firing, the arm is fitted with what is known as the "differential recoil." Above the breach is an air recuperator and a piston, while there is no hydraulic brake such as is generally used. The compressor is kept under compression while the car is travelling with the gun out of action, so that the arm is available for instant firing. This is a departure from the general practice in connection with such weapons. When the gun is loaded the bolt which holds the compressor back is withdrawn, either by the hand for manual firing, or by the action of the automatic closing of the breech when the arm is being used as a quick-firer. In firing the gun is thrown forward under the pressure of the released air which occurs at the moment of discharge. The energy of the recoil brings the gun back and at the same time recharges the compressed air reservoir. The gun is so mounted upon its pedestal as to enable a maximum vertical inclination of 75 degrees to be obtained. The mounting system also enables the weapon to be trained in any desired direction up to the foregoing maximum elevation throughout a complete circle, and it can be handled with ease and celerity. A smaller "Archibald" is the 7.5 centimetre (3-inch gun) throwing a 14.3 pound shell at an initial velocity of about 2,170 feet per second. The turret anti-aircraft gun carried upon a motor-car differs from the foregoing very considerably. This is a protected arm. The gun of 7.1 centimetres--approximately 2.75 inches--is mounted in the same manner upon the car-deck and over the driving axle, but is enclosed within a sheet steel turret, which is proof against rifle and machine-gun fire. This turret resembles the conning-tower of a battleship, and is sufficiently spacious to house the whole of the gun crew, the internal diameter being about seven feet. Access to the turret is obtained through a rear door. This gun has a maximum elevation of about 75 degrees, while its operation and mechanism are similar to those of the unprotected weapon. The vehicle itself is practically identical with the armoured motor-car, which has played such an important part during the present campaign, the driver being protected by a bullet-proof steel screen similar in design to the ordinary glass wind-screen fitted to touring automobiles. This is carried sufficiently high to offer complete protection to his head when seated at the wheel, while through a small orifice in this shield he is able to obtain a clear view of the road. The engine and its vital parts are also adequately protected. The ammunition is carried in a cupboard-like recess forming part of the driver's seat, encased in bullet-proof steel sheeting with flap-doors. This device enables the shells to be withdrawn readily from the side of the car and passed to the crew within the turret. The caisson is of sufficient dimensions to receive 69 shells. The Ehrhardt airship fighting ordnance is similarly adapted to motor-car operations, one type being especially powerful. The whole of the vehicle is encased in armour-plating impervious to rifle and machine-gun fire. The driver is provided with a small orifice through which he is able to obtain a clear uninterrupted view of the road ahead, while the armouring over the tonneau is carried to a sufficient height to allow head-room to the gun crew when standing at the gun. All four wheels are of the disk type and fashioned from heavy sheet steel. The motor develops 40-50 horse-power and, in one type, in order to mitigate the risk of breakdown or disablement, all four wheels are driven. The gun, a small quick-firer, is mounted on a pedestal in a projecting conning-tower. The mounting is placed behind the driver's seat, and is trained and operated from the tonneau. The maximum elevation is 75 degrees, and like the gun carriage bearing the tube guide it can be moved through a complete circle, being free to rotate in the fixed pivot jack to enable this end to be attained. The foregoing may be said to represent the most powerful types of mobile anti-aircraft weapons used by the Austro-German forces to-day. Arms of similar design, roughly speaking, have also been introduced into the French and Russian services. In addition many semi-armoured weapons of this character are in operation, some specially built for the work, while others have been improvised. In the semi-armoured motor-car the carriage follows the usual lines; it has an open top, the armouring comprising the body of the tonneau and the diskwheels, which are made of light bullet-proof steel. Here again the prevailing practice is to mount the gun as nearly above the rear axle as possible, and to work it from the tonneau. The maximum elevation is also 75 degrees, with training throughout the entire circle. Another type comprises a very light machine gun of rifle calibre, and this is intended for attachment to an ordinary motor car. There is a pedestal mounting which can be set within the tonneau, while the weapon is pivoted in an outrigger, the latter being free to rotate in its pivot jack. This arrangement enables the arm to cover a wide range, while it also admits of training through an extensive angle of elevation. The Allied forces improvised travelling anti-aircraft offences by mounting the latest types of Vickers, Hotchkiss, and other machine guns in armoured motor cars. Some of these have the domed turret form, with the gun projecting through the roof, while others are protected against hostile attack from the side only, the carriage being panelled with bullet-proof steel sheeting. While such weapons are useful, inasmuch as they can maintain a hot fire ranging up to 750 shots per minute, they are not to be compared with the "Archibalds," which are able to throw heavy shrapnel and incendiary shells, and have a vertical range of about 6,000 to 8,000 feet. The improvised motor-gun has not proved a complete success, except in those instances when the hostile aircraft has ventured to approach somewhat closely to the ground. The more formidable weapons cannot be mounted upon ordinary vehicles, inasmuch as the increase in weight, which is appreciable, impairs the efficiency of the vehicle, and at the same time enhances the possibility of breakdown at a critical moment. For such arms a special and substantial chassis is imperative, while the motive power and gearing must be adapted to the circumstances. Motor-mounted anti-aircraft weapons, however, have not proved an unqualified success. The fact that the vehicles are condemned to the high roads, or at least to comparatively smooth and level ground, constitutes a severe handicap. Again, when travelling at high speed, and this is essential when pursuing a fast aeroplane, the accurate laying of the weapon is extremely difficult, owing to the oscillation of the vehicle itself, especially if the road surface is in a bad condition. The sighting arrangements are of a wonderfully complete character, as described elsewhere, but the irregular rolling movement arising from high speed is a nullifying quantity. It is tolerably easy for the aircraft, especially an aeroplane, to evade successful pursuit, either by rising to an elevation beyond the range of the gun, or by carrying out baffling evolutions such as irregular undulating flight, wheeling, and climbing. According to the reports of the British and French airmen the "Archibald" has failed to establish the glowing reputation which was anticipated, for the simple reason that, unless it has a clear straight road and can maintain its high speed, it can easily be out-distanced by the fleet human bird. The motor-car suffers from another serious disability. It cannot manoeuvre with sufficient celerity. For instance, if it is necessary to turn round in a narrow lane, valuable time is lost in the process, and this the airman turns to account. In hilly country it is at a still greater disadvantage, the inclines, gradients, and sinuosities of the roads restricting its effectiveness very pronouncedly. It must also be remembered that, relatively speaking, the "Archibald" offers a better target to the airman than the aeroplane offers to the man behind the anti-aircraft gun on the motor below. A few well-placed bombs are sufficient to induce the pursuers to cease their activities. Even if the missiles fail to strike the motor-car itself they can wreak disaster in directly by rendering the road impassable or dangerous to negotiate at high speed. On the whole therefore, the "Archibald" is a greatly exaggerated weapon of offence against aircraft, and, so far as is known, has failed to fulfil expectations. In fact, the Germans have practically abandoned the idea of using it in the manner of a pursuing arm; they work the weapon as a fixture, depending upon the car merely as a means of moving it from point to point. Thus, in reality, it has been converted into a light field-piece, and may almost be included in the category of fixed weapons for combating aerial operations. CHAPTER XV. ANTI-AIRCRAFT GUNS. IMMOBILE WEAPONS The immobile anti-aircraft gun, as distinct from that attached to a travelling carriage such as a motor-car, may be subdivided into two classes. The one is the fixed arm which cannot be moved readily, mounted upon a permanent emplacement; the other is the field-piece which, while fired from a stationary position, may be moved from point to point upon a suitable carriage. The distinction has its parallel in ordinary artillery, the first-named weapon coinciding with the heavy siege gun, which is built into and forms part and parcel of the defensive or offensive scheme, while the second is analogous to the field artillery, which may be wheeled from position to position. In this phase of artillery the Germans led the way, for the simple reason that they recognised the military value of aerial navigation years in advance of their contemporaries. Again, in this field the Krupp Organisation has played a prominent part. It embarked upon actual construction of weapons while its rivals in other countries were content to prepare their drawings, which were filed against "The Day." But it must not be thought that because the German manufacturers of armaments were ahead of their contemporaries they dominated the situation. Far from it. Their competitors in the market of destruction were every whit as keen, as ingenious, and as enterprising. Kruppism saw a commercial opportunity to profit from advertisement and seized it: its rivals were content to work in secret upon paper, to keep pace with the trend of thought, and to perfect their organisations so as to be ready for the crisis when it developed. The first Krupp anti-aircraft field-piece was a 6.5 centimetre (2 9/16 inch) arm. It possessed many interesting features, the most salient of which was the design of the axle of the carriage. The rigid axle for the two wheels was replaced by an axle made in two sections, and joined together in the form of a universal coupling, so that each wheel virtually possessed its own axle, or rather half-axle. This was connected with the cradle of the gun in such a manner that the wheels were laterally pivoted thereon. The result is that each axle can be turned forward together with its wheel, and thus the wheels have their rims brought into line to form an arc of a circle, of which the rear end of the spade of the gun carriage constitutes the centre. This acts as a pivot, about which the gun can be turned, the pair of wheels forming the runners for the achievement of this movement. The setting of the weapon in the firing position or its reversion to the travelling position can be easily and speedily effected merely by the rotation of a handwheel and gearing. With this gun a maximum elevation of 60 degrees is possible, owing to the trunnions being carried well behind the breech in combination with the system of long steady recoil. The balancing spring which encloses the elevating screw is contained in a protected box. The recoil brake, together with the spring recuperator, follows the usual Krupp practice in connection with ordinary field pieces, as does also the automatic breech-closing and firing mechanism. In fact there is no pronounced deviation from the prevailing Krupp system, and only such modifications as are necessary to adapt the arm to its special duty. When the gun is elevated to high angles the shell, after insertion the breech is prevented from slipping out by means of a special device, so that the proper and automatic closing of the breech is not impaired in any way. In such an arm as this, which is designed essentially for high-angle firing, the sighting and training facilities require to be carried out upon special lines, inasmuch as the objective is necessarily at a considerable altitude above the horizon of the gun. In other words, in firing at a high inclination, distance between the gun and the target cannot be utilised directly for the back sight. On the other hand, it is essential that in proportion as the angle from the horizontal increases, the back sight should be lowered progressively in a manner corresponding to the distance. To assist the range-finder in his task of sighting it is necessary that he should be provided with firing tables set out in a convenient form, which, in conjunction with the telemeter, serve to facilitate training for each successive round. In this way it is possible to pick up the range quickly and to keep the objective in the line of fire until it either has been put hors de combat, or has succeeded in retiring beyond the range of the gun. The sighting arrangements of these Krupp anti-aircraft guns are carried out upon these lines. Beneath the barrel of the back-sight is an observing glass with an eye-piece for the artillerist, while above and behind the observing glass is another eye-piece, to be used in conjunction with the manipulation of the back-sight. The eye-piece of the observation glass is so made that it can be turned through a vertical plane in proportion as the angle of fire increases in relation to the horizontal. The determination of the distance from the objective and from the corresponding back-sight as well as the observation of the altitude is carried out with the aid of the telemeter. This again carries an observation glass fitted with an eye-piece which can be turned in the vertical plane in the same manner as that of the fore-sight. By means of this ingenious sighting device it is possible to ascertain the range and angle of fire very easily and speedily. The weight of the special Krupp anti-aircraft field-piece, exclusive of the protecting shield, is approximately identical with that of the ordinary light artillery field-piece. It throws a shell weighing 8.8 pounds with an initial velocity of about 2,066 feet per second. Although the German armament manufacturers were among the first to enter the field with an anti-aircraft gun of this character they were speedily followed by the French, who devised a superior weapon. In fact, the latter represented such a decisive advance that the German artillerists did not hesitate to appropriate their improvements in sundry essential details, and to incorporate them with their own weapons. This applies especially to the differential recoil system which is utilised in the small anti-aircraft guns now mounted upon the roofs of high buildings of cities throughout Germany for the express purpose of repelling aerial attack. The French system is admitted by the leading artillery technicians of the world to be the finest which has ever been designed, its remarkable success being due to the fact that it takes advantage of the laws of Nature. In this system the gun is drawn back upon its cradle preparatory to firing. In some instances the barrel is compressed against a spring, but in the more modern guns it is forced to rest against a cushion of compressed air contained within a cylinder. When first bringing the gun into action, the barrel is brought into the preliminary position by manually compressing the air or spring by means of a lever. Thereafter the gun works automatically. When the gun is fired the barrel is released and it flies forward. At a critical point in its forward travel the charge is fired and the projectile speeds on its way. The kick or recoil serves to arrest the forward movement of the barrel and finally drives it back again against the strong spring or cushion of compressed air within the cylinder to its normal position, when it is ready for the introduction of the next shell. The outstanding feature of this system is that the projectile is given a higher initial velocity than is possible with the barrel held rigid at the moment of discharge, because the shell is already travelling at the moment of firing. The fixed anti-aircraft guns such as are stationed upon eminences and buildings are of the quick firing type, the object being to hurl a steady, continuous stream of missiles upon the swiftly moving aeroplane. Some of the weapons throw a one-pound shell and are closely similar to the pom-pom which proved so effective during the South African war. Machine guns also have been extensively adopted for this duty by all the combatants, their range of approximately 2,000 yards and rapidity of fire being distinctly valuable when hostile aircraft descend to an altitude which brings them within the range of the weapon. The greatest difficulty in connection with this phase of artillery, however, is not so much the evolution of a serviceable and efficient type of gun, as the determination of the type of projectile which is likely to be most effective. While shrapnel is employed somewhat extensively it has not proved completely satisfactory. It is difficult to set the timing fuse even after the range has been found approximately, which in itself is no easy matter when the aircraft is moving rapidly and irregularly, but reliance is placed thereon in the hope that the machine may happen to be within the cone of dispersion when the shell bursts, and that one or more of the pieces of projectile and bullets may chance to penetrate either the body of the airman or a vital part of the mechanism. It is this uncertainty which has led to a preference for a direct missile such as the bullet discharged from a machine gun. A stream of missiles, even of rifle calibre, maintained at the rate of some 400 shots per minute is certain to be more effective, provided range and aim are correct, than shrapnel. But the ordinary rifle-bullet, unless the objective is within very close range, is not likely to cause much harm, at least not to the mechanism of the aerial vessel. It is for this reason that greater attention is being devoted, especially by the French artillerists, to the Chevalier anti-aircraft gun, a weapon perfected by a Swiss technician resident in Great Britain. It projects a formidable missile which in fact is an armour-piercing bullet 1/2- to 3/4-inch in diameter. It is designed for use with an automatic machinegun, which the inventor has devised more or less upon the well-known French system. The bullet has a high velocity--about 2,500 feet per second--and a maximum range of 6,000 to 8,000 feet at the maximum elevation. Should such a missile strike the motor or other mechanism of the vessel it would wreak widespread havoc, and probably cause the machine to come to earth. This arm has been designed for the express purpose of disabling the aeroplane, and not for the subjugation of the airman, which is a minor consideration, inasmuch as he is condemned to a descent when his craft receives a mortal wound. Attempts have been and still are being made to adapt an explosive projectile to this gun, but so far the measure of success achieved has not proved very promising. There are immense difficulties connected with the design of an explosive shell of this class, charged with a high explosive, especially in connection with the timing. So far as dependence upon percussive detonation is concerned there is practically no difficulty. Should such a missile strike, say, the motor of an aeroplane, or even the hull of the craft itself, the latter would be practically destroyed. But all things considered, it is concluded that more successful results are likely to be achieved by the armour-piercing bullet striking the mechanism than by an explosive projectile. The Krupp company fully realised the difficulties pertaining to the projectile problem in attacks upon aerial craft. So far as dirigibles are concerned shrapnel is practically useless, inasmuch as even should the bag be riddled by the flying fragments, little effective damage would be wrought--the craft would be able to regain its haven. Accordingly efforts were concentrated upon the perfection of two new types of projectiles, both of which were directed more particularly against the dirigible. The one is the incendiary shell--obus fumigene--while the other is a shell, the contents of which, upon coming into contact with the gas contained within the gas-bag, set up certain chemical reactions which precipitate an explosion and fire. The incendiary shells are charged with a certain compound which is ignited by means of a fuse during its flight. This fuse arrangement coincides very closely with that attached to ordinary shrapnel, inasmuch as the timing may be set to induce ignition at different periods, such as either at the moment it leaves the gun, before, or when it strikes the envelope of the dirigible. The shell is fitted with a "tracer," that is to say, upon becoming ignited it leaves a trail of smoke, corresponding with the trail of a rocket, so that its passage through the air may be followed with facility. This shell, however, was designed to fulfil a dual. Not only will it fire the gaseous contents out of the dirigible, but it has an explosive effect upon striking an incombustible portion of the aircraft, such as the machinery, propellers or car, when it will cause sufficient damage to throw the craft out of action. The elaborate trials which were carried out with the obus fumigene certainly were spectacular so as they went. Two small spherical balloons, 10 feet in diameter, and attached to 1,000 feet of cable, were sent aloft. The anti-aircraft guns themselves were placed about 5,100 feet distant. Owing to the inclement weather the balloons were unable to attain a height of more than 200 feet in a direct vertical line above the ground. The guns were trained and fired, but the one balloon was not hit until the second round, while the third escaped injury until the fifth round. When struck they collapsed instantly. Though the test was not particularly conclusive, and afforded no reliable data, one point was ascertained--the trail of smoke emitted by the shell enabled its trajectory to be followed with ease. Upon the conclusion of these trials, which were the most successful recorded, quick-firing tests in the horizontal plane were carried out. The best performance in this instance was the discharge of five rounds in eight seconds. In this instance the paths of the projectiles were simple and easy to follow, the flight of the shell being observed until it fell some 18,670 feet away. But the Krupp firm have found that trials upon the testing ground with a captive balloon differ very materially from stern tests in the field of actual warfare. Practically nothing has been heard of the two projectiles during this war, as they have proved an absolute failure. Some months ago the world was startled by the announcement that the leading German armament firm had acquired the whole of the interest in an aerial torpedo which had been evolved by the Swedish artillerist, Gustave Unge, and it was predicted that in the next war widespread havoc would be wrought therewith. Remarkable claims were advanced for this projectile, the foremost being that it would travel for a considerable distance through the air and alight upon the objective with infallible accuracy. The torpedo in question was subjected to exacting tests in Great Britain, which failed to substantiate all the claims which were advanced, and it is significant to observe that little has been heard of it during the present conflict. It is urged in certain technical quarters, however, that the aerial torpedo will prove to be the most successful projectile that can be used against aircraft. I shall deal with this question in a later chapter. During the early days of the war anti-aircraft artillery appeared to be a much overrated arm. The successes placed to its credit were insignificant. This was due to the artillerymen being unfamiliar with the new arm, and the conditions which prevail when firing into space. Since actual practice became possible great advances in marksmanship have been recorded, and the accuracy of such fire to-day is striking. Fortunately the airman possesses the advantage. He can manoeuvre beyond the range of the hostile weapons. At the moment 10,000 feet represents the extreme altitude to which projectiles can be hurled from the arms of this character which are now in use, and they lack destructiveness at that range, for their velocity is virtually expended. Picking up the range is still as difficult as ever. The practice followed by the Germans serves to indicate the Teuton thoroughness of method in attacking such problems even if success does not ensue. The favourite German principle of disposing anti-aircraft artillery is to divide the territory to be protected into equilateral triangles, the sides of which have a length of about six miles or less, according to the maximum effective range of the pieces at an elevation of 23 1/2 degrees. The guns are disposed at the corners of the triangles as indicated in Figs. 13-14. Taking the one triangle as an example, the method of picking up the range may be explained as follows. The several guns at the comers of the triangle, each of which can be trained through the 360 degrees in the horizontal plane, are in telephonic touch with an observer O stationed some distance away. The airman A enters the area of the triangle. The observer takes the range and communicates with the gunner B, who fires his weapon. The shell bursts at 1 emitting a red flame and smoke. The observer notes the altitude and relative position of the explosion in regard to the aircraft, while gunner B himself observes whether the shell has burst to the right or to the left of the objective and corrects accordingly. The observer commands C to fire, and another shell is launched which emits a yellow flame and smoke. It bursts at 2 according to the observer, while gunner C also notes whether it is to the right or to the left of the target and corrects accordingly. Now gunner D receives the command to fire and the shell which explodes at 3 throws off a white flame and smoke. Gunner D likewise observes whether there is any deviation to right or left of the target and corrects in a similar manner. From the sum of the three rounds the observer corrects the altitude, completes his calculations, and communicates his instructions for correction to the three gunners, who now merely train their weapons for altitude. The objective is to induce the shells hurled from the three corners of the triangle to burst at a common point 4, which is considered to be the most critical spot for the aviator. The fire is then practically concentrated from the three weapons upon the apex of a triangular cone which is held to bring the machine within the danger zone. This method of finding the range is carried out quickly--two or three seconds being occupied in the task. In the early days of the war the German anti-aircraft artillerymen proved sadly deficient in this work, but practice improved their fire to a marvellous degree, with the result that at the moment it is dangerous for an aviator to essay his task within an altitude of 6,000 feet, which is the range of the average anti-aircraft gun. The country occupied by a belligerent is divided up in this manner into a series of triangles. For instance, a machine entering hostile territory from the east, enters the triangle A-B-C, and consequently comes within the range of the guns posted at the comers of the triangle. Directly he crosses the line B-C and enters the adjacent triangle he passes beyond the range of gun A but comes within the range of the gun posted at D, and while within the triangular area is under fire from the guns B-C-D. He turns and crosses the line A-C, but in so doing enters another triangle A-C-E, and comes range of the gun posted at E. The accompanying diagram represents an area of country divided up into such triangle and the position of the guns, while the circle round the latter indicate the training arc of the weapons, each of which is a complete circle, in the horizontal plane. The dotted line represents the aviator's line of flight, and it will be seen that no matter how he twists and turns he is always within the danger zone while flying over hostile territory. The moment he outdistances one gun he comes within range of another. The safety of the aviator under these circumstances depends upon his maintaining an altitude exceeding the range of the guns below, the most powerful of which have a range of 8,000 to 10,000 feet, or on speed combined with rapid twisting and turning, or erratic undulating flight, rendering it extremely difficult for the gun-layer to follow his path with sufficient celerity to ensure accurate firing. At altitudes ranging between 4,000 and 6,000 feet the aeroplane comes within the range of rifle and machine-gun firing. The former, however, unless discharged in volleys with the shots covering a wide area, is not particularly dangerous, inasmuch as the odds are overwhelmingly against the rifleman. He is not accustomed to following and firing upon a rapidly moving objective, the result being that ninety-nine times out of a hundred he fails to register a hit. On the other hand the advantage accruing from machine-gun fire is, that owing to the continuous stream of bullets projected, there is a greater possibility of the gun being trained upon the objective and putting it hors de combat. But, taking all things into consideration, and notwithstanding the achievements of the artillerist, the advantages are overwhelmingly on the side of the aviator. When one reflects upon the total sum of aircraft which have been brought to earth during the present campaign, it will be realised that the number of prizes is insignificant in comparison with the quantity of ammunition expended. CHAPTER XVI. MINING THE AIR While the anti-aircraft gun represents the only force which has been brought to the practical stage for repelling aerial attack, and incidentally is the sole offensive weapon which has established its effectiveness, many other schemes have been devised and suggested to consummate these ends. While some of these schemes are wildly fantastic, others are feasible within certain limitations, as for instance when directed against dirigibles. It has been argued that the atmosphere is akin to the salt seas; that an aerial vessel in its particular element is confronted with dangers identical with those prevailing among the waters of the earth. But such an analogy is fallacious: there is no more similarity between the air and the ocean than there is between an airship and a man-of-war. The waters of the earth conceal from sight innumerable obstructions, such as rocks, shoals, sandbanks, and other dangers which cannot by any means be readily detected. But no such impediments are encountered in the ether. The craft of the air is virtually a free age in the three dimensions. It can go whither it will without let or hindrance so long as the mechanical agencies of man are able to cope with the influences of Nature. It can ascend to a height which is out of all proportion to the depth to which the submarine can descend in safety. It is a matter of current knowledge that a submarine cannot sink to a depth of more than 250 feet: an aerial vessel is able to ascend to 5,000, 8,000, or even 10,000 feet above the earth, and the higher the altitude it attains the greater is its degree of safety. The limit of ascension is governed merely by the physical capacities of those who are responsible for the aerial vessel's movement. It is for this reason that the defensive measures which are practised in the waters of the earth are inapplicable to the atmosphere. Movement by, or in, water is governed by the depth of channels, and these may be rendered impassable or dangerous to negotiate by the planting of mines. A passing ship or submarine may circumvent these explosive obstructions, but such a successful manoeuvre is generally a matter of good luck. So far as submarines are concerned the fact must not be over looked that movements in the sea are carried out under blind conditions: the navigator is unable to see where he is going; the optic faculty is rendered nugatory. Contrast the disability of the submarine with the privileges of its consort in the air. The latter is able to profit from vision. The aerial navigator is able to see every inch of his way, at least during daylight. When darkness falls he is condemned to the same helplessness as his confrere in the waters below. A well-known British authority upon aviation suggested that advantage should be taken of this disability, and that the air should be mined during periods of darkness and fog to secure protection against aerial invasion. At first sight the proposal appears to be absolutely grotesque, but a little reflection will suffice to demonstrate its possibilities when the area to be defended is comparatively limited. The suggestion merely proposes to profit from one defect of the dirigible. The latter, when bent upon a daring expedition, naturally prefers to make a bee-line towards its objective: fuel considerations as a matter of fact compel it to do so. Consequently it is possible, within certain limits, to anticipate the route which an invading craft will follow: the course is practically as obvious as if the vessel were condemned to a narrow lane marked out by sign-posts. Moreover, if approaching under cover of night or during thick weather, it will metaphorically "hug the ground." To attempt to complete its task at a great height is to court failure, as the range of vision is necessarily so limited. Under these circumstances the mining of the air could be carried out upon the obvious approaches to a threatened area. The mines, comprising large charges of high-explosive and combustible material, would be attached to small captive balloons similar to the "sounding balloons" which are so much used by meteorologists in operations for sounding the upper strata of the atmosphere. These pilot balloons would be captive, their thin wires being wound upon winches planted at close intervals along the coast-line. The balloon-mines themselves would be sent to varying heights, ranging from 1,000 to 5,000 feet, and with several attached to each cable, the disposition of the mines in the air in such an irregular manner being in fact closely similar to the practice adopted in the mining of a channel for protection against submarines and hostile ships. The suggestion is that these mines should be sent aloft at dusk or upon the approach of thick and foggy weather, and should be wound in at dawn or when the atmosphere cleared, inasmuch as in fine weather the floating aerial menace would be readily detected by the pilot of a dirigible, and would be carefully avoided. If the network were sufficiently intricate it would not be easy for an airship travelling at night or in foggy weather to steer clear of danger, for the wires holding the balloons captive would be difficult to distinguish. The mines would depend upon detonators to complete their work, and here again they would bear a close resemblance to sea-mines. By looping the mines their deadliness could be increased. The unsuspicious airship, advancing under cover of darkness or thick weather, might foul one of the wires, and, driving forward, would tend to pull one or more mines against itself. Under the force of the impact, no matter how gentle, or slight, one or more of the detonating levers would be moved, causing the mine to explode, thus bursting the lifting bag of the vessel, and firing its gaseous contents. An alternative method, especially when a cable carried only a single mine, would be to wind in the captive balloon directly the wire was fouled by an invading aerial craft, the process being continued until the mine was brought against the vessel and thereby detonated. Another proposed mining method differs materially in its application. In this instance it is suggested that the mines should be sent aloft, but should not be of the contact type, and should not be fired by impact detonators, but that dependence should be placed rather upon the disturbing forces of a severe concussion in the air. The mines would be floating aloft, and the advance of the airship would be detected. The elevation of the mines in the vicinity of the invading craft would be known, while the altitude of the airship in relation thereto could be calculated. Then, it is proposed that a mine within d certain radius of the approaching craft, and, of course, below it, should be fired electrically from the ground. It is maintained that if the charge were sufficiently heavy and an adequate sheet of flame were produced as a result of the ignition, an airship within a hundred yards thereof would be imperilled seriously, while the other mines would also be fired, communicating ignition from one to the other. The equilibrium of the airship is so delicate that it can be readily upset, and taking into account the facts that gas is always exuding from the bag, and that hydrogen has a tendency to spread somewhat in the manner of oil upon water, it is argued that the gas would be ignited, and would bring about the explosion of the airship. Another method has even been advocated. It is averred in authoritative circles that when the aerial invasion in force of Great Britain is attempted, the Zeppelins will advance under the cover of clouds. Also that the craft will make for one objective--London. Doubtless advantage will be taken of clouds, inasmuch as they will extend a measure of protection to the craft, and will probably enable the invading fleet to elude the vigilance of the aeroplane scouts and patrols. Under these circumstances it is suggested that balloon-mines should be sent aloft and be concealed in the clouds. It would be impossible to detect the wires holding them captive, so that the precise location of the lurking danger would not be divined by the invader. Of course, the chances are that the invading airship would unconsciously miss the mines; on the other hand the possibilities are equally great that it would blunder into one of these traps and be blown to atoms. An English airman has recently suggested a means of mining invading Zeppelins which differs completely from the foregoing proposals. His idea is that aeroplanes should be equipped with small mines of the contact type, charged with high explosives, and that the latter should be lowered from the aeroplane and be trawled through the atmosphere. As an illustration I will suppose that a hostile aircraft is sighted by a patrolling aeroplane. The pilot's companion in the latter immediately prepares his aerial mine, fixing the detonator, and attaching the mine to the wire. The latter is then dropped overboard, the wire being paid out from a winch until it has descended to the level of the hostile craft. The airman now manoeuvres in the air circling about the airship, dragging his mine behind him, and endeavouring to throw it across or to bring it into contact with the airship below. Naturally the latter, directly it observed the airman's object, would endeavour to elude the pursuing trawling mine, either by crowding on speed or by rising to a greater altitude. The aeroplane, however, would have the advantage both in point of speed and powers of climbing, while there is no doubt that the sight of the mine swinging in the air would exert a decisive moral effect upon those in the airship. Attempts to render the mine harmless by discharging it prematurely with the aid of rifle and machine-gun fire would, of course, be made by the crew of the airship, but the trawling mine would prove a very difficult target to strike. If such a missile were used against an airship of the proportions of a Zeppelin the mine would inevitably be trawled across the vessel sooner or later. Once the airship had been fouled, the aviator would merely have to drive ahead, dragging the wire and its charge across the gas-bag until at last one of the contact levers of the mine was moved by being dragged against some part of the vessel, when the mine would be exploded. In such operations the aviator would run a certain risk, as he would be more or less above the airship, and to a certain degree within the zone of the ultimate explosion. But there is no doubt that he would succeed in his "fishing" exploit within a very short time. This ingenious scheme has already been tested upon a small scale and has been found effective, the trawling bomb being drawn across its target and fired by contact within a few minutes. The experiment seems to prove that it would be simpler and more effectual to attack a hostile aircraft such as a Zeppelin in this manner than to drop free bombs at random. Moreover, we cannot doubt that the sight of a mine containing even ten or twelve pounds of high explosive dangling at the end of a wire would precipitate a retreat on the part of an airship more speedily than any other combative expedient. The advocate of this mine-trawling method, who is a well-known aviator, anticipates no difficulty in manoeuvring a mine weighing 30 pounds at the end of 300 feet of fine wire. Success depends in a great measure on the skill of the aviator in maintaining a constant tension upon the line until it falls across its objective. The process calls for a certain manifestation of skill in manoeuvring the aeroplane in relation to the airship, judgment of distance, and ability to operate the aeroplane speedily. The rapid ascensional capability of the airship, as compared with that of the aeroplane, is a disadvantage, but on the other hand, the superior mobility and speed of the aeroplane would tell decisively for success. Among the many wonders which the Krupp organisation is stated to have perfected, and which it is claimed will create considerable surprise, is the aerial torpedo. Many of the Krupp claims are wildly chimerical, as events have already proved, but there is no doubt that considerable effort has been expended upon this latest missile, for which the firm is said to have paid the inventor upwards of L25,000--$125,000. Curiously enough the projectile was perfected within gunshot of the British aerodrome of Hendon and is stated to have been offered to the British Government at the time, and to have met with a chilling reception. One fact, however, is well established. The inventor went to Germany, and submitted his idea to Krupp, by whom it was tested without delay. Upon the completion of the purchase, the great armament manufacturers did not fail to publish broadcast the fact that they had acquired a mysterious new terror of the skies. That was some three years ago, and in the interval the cleverest brains of the German firm have been steadily devoting their time and energies to the improvement of the missile, the first appearance of which was recorded, in a somewhat hazy manner, in the closing days of December. While the exact mechanism of this missile is a secret, the governing principles of its design and operation are known to a select few technicians in this country. Strange to say, the projectile was designed in the first instance in the interests of peace and humanity, but while engaged upon his experiments the inventor suddenly concluded that it would be a more profitable asset if devoted to the grim game of war. At the time the military significance of the airship and the aeroplane were becoming apparent; hence the sudden diversion of the idea into a destructive channel. This aerial torpedo is a small missile carrying a charge of high explosive, such as trinitrotoluene, and depends for its detonation upon impact or a time fuse. It is launched into the air from a cradle in the manner of the ordinary torpedo, but the initial velocity is low. The torpedo is fitted with its own motive power, which comes automatically into action as the missile climbs into the air. This self-contained energy is so devised that the maximum power is attained before the missile has lost the velocity imparted in the first instance, the result being that it is able to continue its flight in a horizontal direction from the moment it attains the highest point in its trajectory, which is naturally varied according to requirements. But there is no secret about the means of propulsion. The body is charged with a slow-burning combustible, in the manner of the ordinary rocket, whereby it is given a rapid rotary motion. Furthermore it is stated to be fitted with a small gyroscope in the manner of the torpedo used in the seas, for the purpose of maintaining direction during flight, but upon this point there is considerable divergence of opinion among technicians, the general idea being that the torpedo depends upon an application of the principle of the ordinary rocket rather than upon a small engine such as is fitted to the ordinary torpedo. The employment of a slow combustible ensures the maintenance of the missile in the air for a period exceeding that of the ordinary shell. It is claimed by the Germans that this projectile will keep aloft for half-an-hour or more, but this is a phantasy. Its maintenance of flight is merely a matter of minutes. The belated appearance of this much-lauded projectile and its restricted use suggest that it is unreliable, and perhaps no more effective than the aerial torpedo which appeared in the United States during the Spanish-American War, and proved a complete failure. An effective and reliable means of combating or frustrating a dirigible attack, other than by gun-fire or resort to the drastic remedy of ramming the enemy, has yet to be devised. CHAPTER XVII. WIRELESS IN AVIATION In a previous chapter the various methods of signalling between the ground and the airman aloft have been described. Seeing that wireless telegraphy has made such enormous strides and has advanced to such a degree of perfection, one naturally would conclude that it constitutes an ideal system of communication under such conditions in military operations. But this is not the case. Wireless is utilised only to a very limited extent. This is due to two causes. The one is of a technical, the other of a strategical character. The uninitiated, bearing in mind the comparative ease with which wireless installations may be established at a relatively small expense, would not unreasonably think that no serious difficulties of a technical character could arise: at least none which would defy solution. But these difficulties exist in two or three different fields, each of which is peculiarly complex and demands individual treatment. In the first place, there is the weight of the necessary installation. In the case of the dirigible this may be a secondary consideration, but with the aeroplane it is a matter of primary and vital importance. Again, under present conditions, the noise of the motor is apt to render the intelligent deciphering of messages while aloft a matter of extreme difficulty, especially as these are communicated in code. The engine noise might be effectively overcome by the use of a muffler such as, is used with automobiles, but then there is the further difficulty of vibration. This problem is being attacked in an ingenious manner. It is proposed to substitute for audible signals visual interpretations, by the aid of an electric lamp, the fluctuations in which would correspond to the dots and dashes of the Morse code. Thus the airman would read his messages by sight instead of by sound. This method, however, is quite in its infancy, and although attractive in theory and fascinating as a laboratory experiment or when conducted under experimental conditions, it has not proved reliable or effective in aeronautical operations. But at the same time it indicates a promising line of research and development. Then there are the problems of weight and the aerial. So far as present knowledge goes, the most satisfactory form of aerial yet exploited is that known as the trailing wire. From 300 to 700 feet of wire are coiled upon a reel, and when aloft this wire is paid out so that it hangs below the aeroplane. As a matter of fact, when the machine is travelling at high speed it trails horizontally astern, but this is immaterial. One investigator, who strongly disapproves of the trailing aerial, has carried out experiments with a network of wires laid upon and attached to the surface of the aeroplane's wings. But the trailing wire is generally preferred, and certainly up to the present has proved more satisfactory. The greatest obstacle, however, is the necessary apparatus. The average aeroplane designed for military duty is already loaded to the maximum. As a rule it carries the pilot and an observer, and invariably includes a light arm for defence against an aerial enemy, together with an adequate supply of ammunition, while unless short sharp flights are to be made, the fuel supply represents an appreciable load. Under these circumstances the item of weight is a vital consideration. It must be kept within a limit of 100 pounds, and the less the equipment weighs the more satisfactory it is likely to prove, other things being equal. The two most successful systems yet exploited are the Dubilier and the Rouget. The former is an American invention, the latter is of French origin. Both have been tested by the British Military Aeronautical Department, and the French authorities have subjected the French system to rigorous trials. Both systems, within their limitations, have proved satisfactory. The outstanding feature of the Dubilier system is the production of sine waves of musical frequency from continuous current, thus dispensing with the rotary converter. The operating principle is the obtaining of a series of unidirectional impulses by a condenser discharge, the pulsating currents following one another at regular intervals at a frequency of 500 impulses per second, which may be augmented up to 1,000 impulses per second. The complete weight of such an apparatus is 40 pounds; the electric generator, which is no larger than the motor used for driving the ordinary table ventilating fan, accounts for 16 pounds of this total. Under test at sea, upon the deck of a ship, a range of 250 miles has been obtained. The British Government carried out a series of experiments with this system, using a small plant weighing about 30 pounds, with which communication was maintained up to about 20 miles. In the French system the Reuget transmitter is employed. The apparatus, including the dynamo, which is extremely small, weighs in all 70 pounds. A small alternator of 200 watts and 100 volts is coupled direct to the aeroplane motor, a new clutch coupler being employed for this purpose. By means of a small transformer the voltage is raised to 30,000 volts, at which the condenser is charged. In this instance the musical spark method is employed. The whole of the high tension wiring is placed within a small space so as not to endanger the pilot, while the transformer is hermetically sealed in a box with paraffin. The aerial comprises a trailing wire 100 feet in length, which, however, can be wound in upon its reel within 15 seconds. This reeled antenna, moreover, is fitted with a safety device whereby the wire can be cut adrift in the event of an accident befalling the aeroplane and necessitating an abrupt descent. With this apparatus the French authorities have been able to maintain communication over a distance of 30 miles. In maintaining ethereal communication with aeroplanes, however, a portable or mobile station upon the ground is requisite, and this station must be within the radius of the aerial transmitter, if messages are to be received from aloft with any degree of accuracy and reliability. Thus it will be recognised that the land station is as important as the aeroplane equipment, and demands similar consideration. A wide variety of systems have been employed to meet these conditions. There is the travelling automobile station, in which the installation is mounted upon a motor-car. In this instance the whole equipment is carried upon a single vehicle, while the antenna is stowed upon the roof and can be raised or lowered within a few seconds. If motor traction is unavailable, then animal haulage may be employed, but in this instance the installation is divided between two vehicles, one carrying the transmitting and receiving apparatus and the generating plant, the other the fuel supplies and the aerial, together with spare parts. The motive power is supplied by a small air cooled petrol or gasoline motor developing eight horse-power, and coupled direct to a 2-kilo watt alternator. At one end of the shaft of the latter the disk discharger is mounted, its function being to break up the train of waves into groups of waves, so as to impart a musical sound to the note produced in the receiver. A flexible cable transmits the electric current from the generator to the wagon containing the instruments. The aerial is built up of masts carried in sections. The Germans employ a mobile apparatus which is very similar, but in this instance the mast is telescopic. When closed it occupies but little space. By turning the winch handle the mast is extended, and can be carried to any height up to a maximum of about 100 feet. The capacity of these mobile stations varies within wide limits, the range of the largest and most powerful installations being about 200 miles. The disadvantage of these systems, however, is that they are condemned to territories where the ground at the utmost is gently undulating, and where there are roads on which four-wheeled vehicles can travel. For operation in hilly districts, where only trails are to be found, the Marconi Company, has perfected what may be described as "pack" and "knapsack" installations respectively. In the first named the whole of the installation is mounted upon the backs of four horses. The first carries the generator set, the second the transmitting instruments, the third the receiving equipment, and the fourth the detachable mast and stays. The generator is carried upon the horse's saddle, and is fitted with a pair of legs on each side. On one side of the saddle is mounted a small highspeed explosion motor, while on the opposite side, in axial alignment with the motor, is a small dynamo. When it is desired to erect the installation the saddle carrying this set is removed from the horse's back and placed upon the ground, the legs acting as the support. A length of shaft is then slipped into sockets at the inner ends of the motor and dynamo shafts respectively, thus coupling them directly, while the current is transmitted through a short length of flexible cable to the instruments. The mast itself is made in lengths of about four feet, which are slipped together in the manner of the sections of a fishing rod, and erected, being supported by means of wire guys. In this manner an antenna from 40 to 50 feet in height may be obtained. The feature of this set is its compactness, the equal division of the sections of the installation, and the celerity with which the station may be set up and dismantled in extremely mountainous country such as the Vosges, where it is even difficult for a pack-horse to climb to commanding or suitable positions, there is still another set which has been perfected by the Marconi Company. This is the "knapsack" set, in which the whole of the installation, necessarily light, small, and compact, is divided among four men, and carried in the manner of knapsacks upon their backs. Although necessarily of limited radius, such an installation is adequate for communication within the restricted range of air-craft. Greater difficulties have to be overcome in the mounting of a wireless installation upon a dirigible. When the Zeppelin was finally accepted by the German Government, the military authorities emphasised the great part which wireless telegraphy was destined to play in connection with such craft. But have these anticipations been fulfilled? By no means, as a little reflection will suffice to prove. In the first place, a wireless outfit is about the most dangerous piece of equipment which could be carried by such a craft as the Zeppelin unless it is exceptionally well protected. As is well known the rigidity of this type of airship is dependent upon a large and complicated network of aluminium, which constitutes the frame. Such a huge mass of metal constitutes an excellent collector of electricity from the atmosphere; it becomes charged to the maximum with electricity. In this manner a formidable contributory source of danger to the airship is formed. In fact, this was the reason why "Z-IV" vanished suddenly in smoke and flame upon falling foul of the branches of trees during its descent. At the time the Zeppelin was a highly charged electrical machine or battery as it were, insulated by the surrounding air. Directly the airship touched the trees a short circuit was established, and the resultant spark sufficed to fire the gas, which is continuously exuding from the gas bags. After this accident minute calculations were made and it was ascertained that a potential difference of no less than 100,00 volts existed between the framework of the dirigible and the trees. This tension sufficed to produce a spark 4 inches in length. It is not surprising that the establishment of the electric equilibrium by contact with the trees, which produced such a spark should fire the hydrogen inflation charge. In fact the heat generated was so intense that the aluminium metallic framework was fused. The measurements which were made proved that the gas was consumed within 15 seconds and the envelope destroyed within 20 seconds. As a result of this disaster endeavours were made to persuade Count Zeppelin to abandon the use of aluminium for the framework of his balloon but they were fruitless, a result no doubt due to the fact that the inventor of the airship of this name has but a superficial knowledge of the various sciences which bear upon aeronautics, and fully illustrates the truth of the old adage that "a little learning is a dangerous thing." Count Zeppelin continues to work upon his original lines, but the danger of his system of construction was not lost upon another German investigator, Professor Schiitte, who forthwith embarked upon the construction of another rigid system, similar to that of Zeppelin, at Lanz. In this vessel aluminium was completely abandoned in favour of a framework of ash and poplar. The fact that the aluminium constituted a dangerous collector of electricity rendered the installation of wireless upon the Zeppelin not only perilous but difficult. Very serious disturbances of an electrical nature were set up, with the result that wireless communication between the travelling dirigible and the ground below was rendered extremely uncertain. In fact, it has never yet been possible to communicate over distances exceeding about 150 miles. Apart from this defect, the danger of operating the wireless is obvious, and it is generally believed in technical circles that the majority of the Zeppelin disasters from fire have been directly attributable to this, especially those disasters which have occurred when the vessel has suddenly exploded before coming into contact with terrestrial obstructions. In the later vessels of this type the wireless installation is housed in a well insulated compartment. This insulation has been carried, to an extreme degree, which indicates that at last the authorities have recognised the serious menace that wireless offers to the safety of the craft, with the result that every protective device to avoid disaster from this cause has been freely adopted. The fact that it is not possible to maintain communication over a distance exceeding some 20 miles is a severe handicap to the progressive development of wireless telegraphy in this field. It is a totally inadequate radius when the operations of the present war are borne in mind. A round journey of 200, or even more miles is considered a mere jaunt; it is the long distance flight which counts, and which contributes to the value of an airman's observations. The general impression is that the fighting line or zone comprises merely two or three successive stretches of trenches and other defences, representing a belt five miles or so in width, but this is a fallacy. The fighting zone is at least 20 miles in width; that is to say, the occupied territory in which vital movements take place represents a distance of 20 miles from the foremost line of trenches to the extreme rear, and then comes the secondary zone, which may be a further 10 miles or more in depth. Consequently the airman must fly at least 30 miles in a bee-line to cover the transverse belt of the enemy's field of operations. Upon the German and Russian sides this zone is of far greater depth, ranging up to 50 miles or so in width. In these circumstances the difficulties of ethereal communication 'twixt air and earth may be realised under the present limitations of radius from which it is possible to transmit. But there are reasons still more cogent to explain why wireless telegraphy has not been used upon a more extensive scale during the present campaign. Wireless communication is not secretive. In other words, its messages may be picked up by friend and foe alike with equal facility. True, the messages are sent in code, which may be unintelligible to the enemy. In this event the opponent endeavours to render the communications undecipherable to one and all by what is known as "jambing." That is to say, he sends out an aimless string of signals for the purpose of confusing senders and receivers, and this is continued without cessation and at a rapid rate. The result is that messages become blurred and undecipherable. But there is another danger attending the use of wireless upon the battlefield. The fact that the stations are of limited range is well known to the opposing forces, and they are equally well aware of the fact that aerial craft cannot communicate over long distances. For instance, A sends his airmen aloft and conversation begins between the clouds and the ground. Presently the receivers of B begin to record faint signals. They fluctuate in intensity, but within a few seconds B gathers that an aeroplane is aloft and communicating with its base. By the aid of the field telephone B gets into touch with his whole string of wireless stations and orders a keen look-out and a listening ear to ascertain whether they have heard the same signals. Some report that the signals are quite distinct and growing louder, while others declare that the signals are growing fainter and intermittent. In this manner B is able to deduce in which direction the aeroplane is flying. Thus if those to the east report that signals are growing stronger, while the stations on the west state that they are diminishing, it is obvious that the aeroplane is flying west to east, and vice versa when the west hears more plainly at the expense of the east. If, however, both should report that signals are growing stronger, then it is obvious that the aircraft is advancing directly towards them. It was this ability to deduce direction from the sound of the signals which led to the location of the Zeppelin which came down at Luneville some months previous to the war, and which threatened to develop into a diplomatic incident of serious importance. The French wireless stations running south-east to north-west were vigilant, and the outer station on the north-west side picked up the Zeppelin's conversation. It maintained a discreet silence, but communicated by telephone to its colleagues behind. Presently No. 2 station came within range, followed by Nos. 3, 4, 5, 6, and so on in turn. Thus the track of the Zeppelin was dogged silently through the air by its wireless conversation as easily and as positively as if its flight had been followed by the naked eye. The Zeppelin travellers were quite ignorant of this action upon the part of the French and were surprised when they were rounded-up to learn that they had been tracked so ruthlessly. Every message which the wireless of the Zeppelin had transmitted had been received and filed by the French. Under these circumstances it is doubtful whether wireless telegraphy between aircraft and the forces beneath will be adopted extensively during the present campaign. Of course, should some radical improvement be perfected, whereby communication may be rendered absolutely secretive, while no intimation is conveyed to the enemy that ethereal conversation is in progress, then the whole situation will be changed, and there may be remarkable developments. CHAPTER XVIII. AIRCRAFT AND NAVAL OPERATIONS When once the flying machine had indicated its possibilities in connection with land operations it was only natural that endeavours should be made to adapt it to the more rigorous requirements of the naval service. But the conditions are so vastly dissimilar that only a meagre measure of success has been recorded. Bomb-throwing from aloft upon the decks of battleships appeals vividly to the popular imagination, and the widespread destruction which may be caused by dropping such an agent down the funnel of a vessel into the boiler-room is a favourite theme among writers of fiction and artists. But hitting such an objective while it is tearing at high speed through the water, from a height of several thousand feet is a vastly different task from throwing sticks and balls at an Aunt Sally on terra firma: the target is so small and elusive. Practically it is impossible to employ the flying machine, whether it be a dirigible or an aeroplane, in this field. Many factors militate against such an application. In the first place there is a very wide difference between dry land and a stretch of water as an area over which to manoeuvre. So far as the land is concerned descent is practicable at any time and almost anywhere. But an attempt to descend upon the open sea even when the latter is as calm as the proverbial mill-pond is fraught with considerable danger. The air-currents immediately above the water differ radically from those prevailing above the surface of the land. Solar radiation also plays a very vital part. In fact the dirigible dare not venture to make such a landing even if it be provided with floats. The chances are a thousand to one that the cars will become water-logged, rendering re-ascent a matter of extreme difficulty, if not absolutely impossible. On the other hand, the aeroplane when equipped with floats, is able to alight upon the water, and to rest thereon for a time. It may even take in a new supply of fuel if the elements be propitious, and may be able to re-ascend, but the occasions are rare when such operations can be carried out successfully. In operations over water the airman is confronted with one serious danger--the risk of losing his bearings and his way. For instance, many attempts have been made to cross the North Sea by aeroplane, but only one has proved successful so far. The intrepid aviator did succeed in passing from the shore of Britain to the coast of Scandinavia. Many people suppose that because an airman is equipped with a compass he must be able to find his way, but this is a fallacy. The aviator is in the same plight as a mariner who is compelled from circumstances to rely upon his compass alone, and who is debarred by inclement weather from deciding his precise position by taking the sun. A ship ploughing the waters has to contend against the action of cross currents, the speed of which varies considerably, as well as adverse winds. Unless absolute correction for these influences can be made the ship will wander considerably from its course. The airman is placed in a worse position. He has no means of determining the direction and velocity of the currents prevailing in the atmosphere, and his compass cannot give him any help in this connection, because it merely indicates direction. Unless the airman has some means of determining his position, such as landmarks, he fails to realise the fact that he is drifting, or, even if he becomes aware of this fact, it is by no means a simple straightforward matter for him to make adequate allowance for the factor. Side-drift is the aviator's greatest enemy. It cannot be determined with any degree of accuracy. If the compass were an infallible guide the airman would be able to complete a given journey in dense fog just as easily as in clear weather. It is the action of the cross currents and the unconscious drift which render movement in the air during fog as impracticable with safety as manoeuvring through the water under similar conditions. More than one bold and skilful aviator has essayed the crossing of the English Channel and, being overtaken by fog, has failed to make the opposite coast. His compass has given him the proper direction, but the side-drift has proved his undoing, with the result that he has missed his objective. The fickle character of the winds over the water, especially over such expanses as the North Sea, constitutes another and seriously adverse factor. Storms, squalls, gales, and, in winter, blizzards, spring up with magical suddenness, and are so severe that no aircraft could hope to live in them. But such visitations are more to be dreaded by the lighter-than-air than by the heavier-than-air machines. The former offers a considerable area of resistance to the tempest and is caught up by the whirlwind before the pilot fully grasps the significant chance of the natural phenomenon. Once a dirigible is swept out of the hands of its pilot its doom is sealed. On the other hand, the speed attainable by the aeroplane constitutes its safety. It can run before the wind, and meantime can climb steadily and rapidly to a higher altitude, until at last it enters a contrary wind or even a tolerably quiescent atmosphere. Even if it encounters the tempest head on there is no immediate danger if the aviator keep cool. This fact has been established times out of number and the airman has been sufficiently skilful and quick-witted to succeed in frustrating the destructive tactics of his natural enemy. Only a short while ago in France, British airmen who went aloft in a gale found the latter too strong for them. Although the machine was driven full speed ahead it was forced backwards at the rate of 10 miles per hour because the independent speed of the aeroplane was less than the velocity of the wind. But a dirigible has never succeeded in weathering a gale; its bulk, area, and weight, combined with its relatively slow movement, are against it, with the result that it is hurled to destruction. All things considered, the dirigible is regarded as an impracticable acquisition to a fleet, except in the eyes of the Germans, who have been induced to place implicit reliance upon their monsters. The gullible Teuton public confidently believes that their Dreadnoughts of the air will complete the destruction of the British fleet, but responsible persons know full well that they will not play such a part, but must be reserved for scouting. Hitherto, in naval operations, mosquito water-craft, such as torpedo-boats, have been employed in this service. But these swift vessels suffer from one serious disability. The range of vision is necessarily limited, and a slight mist hanging over the water blinds them; the enemy may even pass within half-a-mile of them and escape detection. The Zeppelin from its position 1,000 feet or more above the water, in clear weather, has a tremendous range of vision; the horizon is about 40 miles distant, as compared with approximately 8 miles in the case of the torpedo-boat. Of course an object, such as a battleship, may be detected at a far greater range. Consequently the German naval programme is to send the Zeppelin a certain distance ahead of the battleship squadron. The dirigible from its coign of vantage would be able to sight a hostile squadron if it were within visual range and would communicate the fact to the commander of the fleet below. The latter would decide his course according to information received; thus he would be enabled to elude his enemy, or, if the tidings received from the aerial scout should be favourable, to dispose his vessels in the most favourable array for attack. The German code of naval tactics does not foreshadow the use of dirigible aircraft as vessels of attack. Scouting is the primary and indeed the only useful duty of the dirigible, although it is quite possible that the aerial craft might participate in a subsequent naval engagement, as, indeed, has been the case. Its participation, however, would be governed entirely by climatic conditions. The fact that the dirigible is a weak unit of attack in naval operations is fully appreciated by all the belligerents. The picture of a sky "black with Zeppelins" may appeal to the popular imagination, and may induce the uninitiated to cherish the belief that such an array would strike terror into the hearts of the foe, but the naval authorities are well aware that no material advantage would accrue from such a force. In the first place they would constitute an ideal target for the enemy's vessels. They would be compelled to draw within range in order to render their own attack effective, and promiscuous shooting from below would probably achieve the desired end. One or more of the hostile aircraft would be hit within a short while. Such disasters would undoubtedly throw the aerial fleet into confusion, and possibly might interfere with the tactical developments of its own friends upon the water below. The shells hurled from the Zeppelins would probably inflict but little damage upon the warships beneath. Let it be conceded that they weigh about 500 pounds, which is two-thirds of the weight of the projectile hurled from the Krupp 128-centimetre howitzer. Such a missile would have but little destructive effect if dropped from a height of 1,000 feet. To achieve a result commensurate with that of the 28-centimetre howitzer the airship would have to launch the missile from a height of about 7,000 feet. To take aim from such an altitude is impossible, especially at a rapidly moving target such as a battle-cruiser. The fact must not be forgotten that Count Zeppelin himself has expressed the opinion, the result of careful and prolonged experiments, that his craft is practically useless at a height exceeding 5,000 feet. Another point must not be overlooked. In a spirited naval engagement the combatants would speedily be obliterated from the view of those aloft by the thick pall of smoke--the combination of gun-fire and emission from the furnaces and a blind attack would be just as likely to damage friend as foe. Even if the aircraft ventured to descend as low as 5,000 feet it would be faced with another adverse influence. The discharge of the heavy battleship guns would bring about such an agitation of the air above as to imperil the delicate equilibrium of an airship. Nor must one overlook the circumstance that in such an engagement the Zeppelins would become the prey of hostile aeroplanes. The latter, being swifter and nimbler, would harry the cumbersome and slow-moving dirigible in the manner of a dog baiting a bear to such a degree that the dirigible would be compelled to sheer off to secure its own safety. Desperate bravery and grim determination may be magnificent physical attributes, ut they would have to be superhuman to face the stinging recurrent attacks of mosquito-aeroplanes. The limitations of the Zeppelin, and in fact of all dirigible aircraft, were emphasised upon the occasion of the British aerial raid upon Cuxhaven. Two Zeppelins bravely put out to overwhelm the cruisers and torpedo boats which accompanied and supported the British sea-planes, but when confronted with well-placed firing from the guns of the vessels below they quickly decided that discretion was the better part of valour and drew off. In naval operations the aeroplane is a far more formidable foe, although here again there are many limitations. The first and most serious is the severely limited radius of action. The aeroplane motor is a hungry engine, while the fuel capacity of the tank is restricted. The German military authorities speedily realised the significance of this factor and its bearing upon useful operations, and forth with carried out elaborate endurance tests. In numerable flights were made with the express purpose of determining how long a machine could remain in the air upon a single fuel supply. The results of these flights were collated and the achievements of each machine in this direction carefully analysed, a mean average drawn up, and then pigeon-holed. The results were kept secret, only the more sensational records being published to the world. As the policy of standardisation in the construction of aeroplanes was adopted the radius of action of each type became established. It is true that variations of this factor even among vessels exactly similar in every respect are inevitable, but it was possible to establish a reliable mean average for general guidance. The archives of the Berlin military department are crowded with facts and figures relating to this particular essential, so that the radius of action, that is the mileage upon a single fuel charge, of any class and type of machine may be ascertained in a moment. The consequence is that the military authorities are able to decide the type of aeroplane which is best suited to a certain projected task. According to the dossier in the pigeon-hole, wherein the results of the type are filed, the aeroplane will be able to go so far, and upon arriving at that point will be able to accomplish so much work, and then be able to return home. Consequently it is dispatched upon the especial duty without any feeling of uncertainty. Unfortunately, these experimental processes were too methodical to prove reliable. The endurance data were prepared from tests carried out in the aerodrome and from cross-country trials accomplished under ideal or fair-weather conditions. The result is that calculations have been often upset somewhat rudely by weather conditions of a totally unexpected character, which bring home vividly the striking difference between theory and practice. The British and French aviation authorities have not adopted such methodical standardisation or rule of thumb inferences, but rather have fostered individual enterprise and initiative. This stimulation of research has been responsible for the creation of a type of aeroplane specially adapted to naval service, and generically known as the water plane, the outstanding point of difference from the aeroplane being the substitution of canoes or floats for the wheeled chassis peculiar to the land machine. The flier is sturdily built, while the floats are sufficiently substantial to support the craft upon the water in calm weather. Perhaps it was the insular situation of the British nation which was responsible for this trend of development, because so far as Britain is concerned the sea-going aeroplane is in dispensable. But the salient fact remains that to-day the waterplane service of Great Britain is the most efficient in the world, the craft being speedy, designed and built to meet the rough weather conditions which are experienced around these islands, and ideal vessels for patrol and raiding duties. So far as the British practice is concerned the waterplane is designed to operate in conjunction with, and not apart from, the Navy. It has been made the eyes of the Navy in the strictest interpretation of the term. In any such combination the great difficulty is the establishment of what may be termed a mobile base, inasmuch as the waterplane must move with the fleet. This end has been achieved by the evolution of a means of carrying a waterplane upon, and launching it from, a battleship, if necessary. For this purpose a docking cradle or way has been provided aft where the aeroplane may be housed until the moment arrives for its employment. Several vessels have been devoted to this nursing duty and are known as parent ships to the waterplane service. All that is requisite when the time arrives for the use of the seaplane is to lift it bodily by derrick or crane from its cradle and to lower it upon the water. It will be remembered that the American naval authorities made an experiment with a scheme for directly launching the warplane from the deck of a battleship in the orthodox, as well as offering it a spot upon which to alight upon returning from a flight, while Wing-Commander Samson, R.N., D.S.O., the famous British airman, repeated the experiment by flying from a similar launching way installed upon H.M.S. Hibernia. But this practice has many shortcomings. So far as the British and French navies are concerned, the former process is preferred. Again, when the waterplane returns from a flight it is admitted that it is simpler, quicker, and safer for it to settle upon the water near the parent ship and to be lifted on board. As a sea-scout the waterplane is overwhelmingly superior to the dirigible as events have conclusively proved. Its greater mobility and speed stand it in excellent stead because it is able to cover a larger area within a shorter space of time than its huge and unwieldy contemporary. Furthermore, it is a difficult target to hit and accordingly is not so likely to be brought down by hostile fire. There is another point in its favour. The experience of the war has proved that the numerically inferior enemy prefers to carry out his naval operations under the cover of the mist and haze which settle upon the water, and yet are of sufficient depth to conceal his identity and composition. Such mists as a rule comprise a relatively thin bank of low-lying vapour, which while enveloping the surface of the water in an impenetrable pall, yet permits the mast-heads of the vessels to stand out clearly, although they cannot be detected from the water-level or even from the control and fighting tops of a warship. A scouting waterplane, however, is able to observe them and note their movement, and accordingly can collect useful information concerning the apparent composition of the hidden force, the course it is following, its travelling speed, and so forth, which it can convey immediately to its friends. The aeroplane has established its value in another manner. Coal-burning vessels when moving at any pronounced speed invariably throw off large quantities of smoke, which may be detected easily from above, even when the vessels themselves are completely hidden in the mist. It was this circumstance which revealed the presence of the British squadron in the affair of the Bight of Heligoland. The German airman on patrol duty from the adjacent base on the island of Heligoland detected the presence of this smoke, above the low-lying bank of fog, although there were no other visible signs of any vessels. Fully cognisant of the fact that the German Fleet was at anchor in a safe place he naturally divined that the smoke proceeded from a hostile squadron, evidently bent upon a raid. He returned to his headquarters, conveyed the intelligence he had collected to his superior officers, upon receipt of which a German cruiser squadron was sent out and engaged the British vessels to its own discomfiture. But for the airman's vigilance and smartness there is no doubt that the British squadron would have accomplished a great coup. This incident, however, served to reveal that the aerial scout is prone to suffer from over-keenness and to collect only a partial amount of information. Upon this occasion the German watchman detected the presence of the British torpedo-boat and light cruiser force. Had he continued his investigations and made a wider sweep he would have discovered the proximity of the British battle-cruiser squadron which routed the German force, the latter having acted on incomplete information. While the low-lying sea-fog is the navigator's worst enemy, it is the airman's greatest friend and protection. It not only preserves him against visual discovery from below, but is an excellent insulator of sound, so that his whereabouts is not betrayed by the noise of his motor. It is of in calculable value in another way. When a fog prevails the sea is generally as smooth as the pro verbial mirror, enabling the waterplanes to be brought up under cover to a suitable point from which they may be dispatched. Upon their release by climbing to a height of a few hundred feet the airmen are able to reach a clear atmosphere, where by means of the compass it is possible to advance in approximately the desired direction, safe from discovery from below owing to the fog. If they are "spotted" they can dive into its friendly depths, complete their work, and make for the parent ship. Low-lying sea-fogs are favourable to aerial raids provided the scout is able to catch sight of the upper parts of landmarks to enable him to be sure of the correctness of his line of flight-in cases where the distance is very short compass direction is sufficiently reliable-because the bank of vapour not only constitutes a perfect screen, but serves as a blanket to the motor exhaust, if not completely, at least sufficiently to mislead those below. Fogs, as every mariner will testify, play strange tricks with the transmission of sound. Hence, although those on the vessels below might detect a slight hum, it might possibly be so faint as to convey the impression that the aviator was miles away, when, as a matter of fact, he was directly overhead. This confusion arising from sound aberration is a useful protection in itself, as it tends to lure a naval force lying in or moving through the fog into a false sense of security. The development of the submarine revealed the incontrovertible fact that this arm would play a prominent part in future operations upon the water: a presage which has been adequately fulfilled during the present conflict. The instinct of self-preservation at once provoked a discussion of the most effective ways and means of disguising its whereabouts when it travels submerged. To this end the German naval authorities conducted a series of elaborate and interesting experiments off the island of Heligoland. As is well known, when one is directly above a stretch of shallow water, the bottom of the latter can be seen quite distinctly. Consequently, it was decided to employ aerial craft as detectives. Both the aeroplane and the dirigible took part in these experiments, being flown at varying heights, while the submarine was maneouvred at different depths immediately below. The sum of these investigations proved conclusively that a submarine may be detected from aloft when moving at a depth of from 30 to 40 feet. The outline of the submerged craft is certainly somewhat blurred, but nevertheless it is sufficiently distinct to enable its identity to be determined really against the background or bottom of the sea. To combat this detection from an aerial position it will be necessary inter alia to evolve a more harmonious or protective colour-scheme for the submarine. Their investigations were responsible for the inauguration of the elaborate German aerial patrol of harbours, the base for such aerial operations being established upon the island of Heligoland. So far the stern test of war as applied to the science of aeronautics has emphasised the fact that as a naval unit the dirigible is a complete failure. Whether experience will bring about a modification of these views time alone will show, but it is certain that existing principles of design will have to undergo a radical revision to achieve any notable results. The aeroplane alone has proved successful in this domain, and it is upon this type of aerial craft that dependence will have to be placed. CHAPTER XIX. THE NAVIES of THE AIR Less than three years ago the momentous and spectacular race among the Powers of Europe for the supremacy of the air began. At first the struggle was confined to two rivals--France and Germany--but as time progressed and the importance of aerial fleets was recognised, other nations, notably Great Britain, entered the field. Germany obtained an advantage. Experiment and research were taken up at a point which had been reached by French effort; further experiments and researches were carried out in German circles with secret and feverish haste, with the result that within a short time a pronounced degree of efficiency according to German ideals had been attained. The degree of perfection achieved was not regarded with mere academic interest; it marked the parting of the ways: the point where scientific endeavour commanded practical appreciation by turning the success of the laboratory and aerodrome into the channel of commercial manufacture. In other words, systematic and wholesale production was undertaken upon an extensive scale. The component parts were standardised and arrangements were completed with various establishments possessed of the most suitable machinery to perfect a programme for turning out aeronautical requirements in a steady, continuous stream from the moment the crisis developed. The wisdom of completing these arrangements in anticipation is now apparent. Upon the outbreak of hostilities many German establishments devoted to the production of articles required in the infinite ramifications of commerce found themselves deprived of their markets, but there was no risk that their large plants would be brought to a standstill: the Government ordered the manufacture of aeroplane parts and motors upon an extensive scale. In this manner not only were the industrial establishments kept going, but their production of aeronautical requirements relieved those organisations devoted to the manufacture of armaments, so that the whole resources and facilities of these could be concentrated upon the supply of munitions of war. In France the air-fleet, although extensive upon the outbreak of war, was somewhat heterogeneous. Experiment was still being pursued: no type had met with definite official recognition, the result being that no arrangements had been completed for the production of one or more standard types upon an elaborate scale comparable with that maintained by Germany. In fact some six months after the outbreak of war there was an appreciable lack of precision on this point in French military. Many of the types which had established their success were forbidden by military decree as mentioned in a previous chapter, while manufacturing arrangements were still somewhat chaotic. Great Britain was still more backward in the new movement. But this state of affairs was in a measure due to the division of the Fourth Arm among the two services. A well-organised Government manufactory for the production of aeroplanes and other aircraft necessities had been established, while the private manufacturers had completed preparations for wholesale production. But it was not until the Admiralty accepted responsibility for the aerial service that work was essayed in grim earnest. The allocation of the aerial responsibilities of Great Britain to the Admiralty was a wise move. Experience has revealed the advantages accruing from the perfection of homogeneous squadrons upon the water, that is to say groups of ships which are virtually sister-craft of identical speed, armament, and so on, thus enabling the whole to act together as a complete effective unit. As this plan had proved so successful upon the water, the Admiralty decided to apply it to the fleet designed for service in the air above. At the time this plan of campaign was definitely settled Great Britain as an aerial power was a long way behind her most formidable rival, but strenuous efforts were made to reduce the handicap, and within a short while the greater part of this leeway had been made up. Upon the outbreak of war Great Britain undoubtedly was inferior to Germany in point of numbers of aircraft, but the latter Power was completely outclassed in efficiency, and from the point of view of PERSONNEL. The British had developed the waterplane as an essential auxiliary to naval operations, and here was in advance of her rival, who had practically neglected this line of experiment and evolution, resting secure in the assurance of her advisers that the huge dirigibles would be adequate for all exigencies on the water. Indeed, when war was declared, all the Powers were found more or less wanting so far as their aerial fleets were concerned. If Germany's huge aerial navy had been in readiness for instant service when she invaded Belgium, she would have overcome that little country's resistance in a far shorter time and with much less waste of life. It was the Belgians who first brought home to the belligerents the prominent part that aircraft were destined to play in war, and the military possibilities of the aeroplane. True, the Belgians had a very small aerial navy, but it was put to work without delay and accomplished magnificent results, ascertaining the German positions and dispositions with unerring accuracy and incredible ease, and thus enabling the commander of the Belgian Army to dispose his relatively tiny force to the best advantage, and to offer the most effective resistance. Great Britain's aerial navy, while likewise some what small, was also ready for instant service. The British Expeditionary force was supported by a very efficient aerial fleet, the majority of the vessels forming which flew across the Channel at high speed to the British headquarters in France so as to be available directly military preparations were begun, and the value of this support proved to be inestimable, since it speedily demoralised the numerically superior enemy. France, like Germany, was somewhat dilatory, but this was attributable rather to the time occupied in the mobilisation of the Fourth Arm than to lack of energy. There were a round 1,500 aeroplanes ostensibly ready for service, in addition to some 26 dirigibles. But the fleet was somewhat scattered, while many of the craft were not immediately available, being in the shops or in dock for repairs and overhaul. During the period of mobilisation the so-called standing military force was augmented by about 500 machines which were acquired from private owners. The aeroplane factories were also, overhauled and re-organised so as to be in a position to remedy the inevitable wastage, but these organisation efforts were somewhat handicapped by the shortage of labour arising from the call to arms. France, moreover, imperilled her aerial strength by forbidding the use of 558 machines which were ready for service. Germany's aerial fleet was of similar proportions to that of her Gallic neighbour, but curiously enough, and in strange contrast, there appeared to be a lack of readiness in this ramification of the Teuton war machine. The military establishment possessed about 1,000 machines--active and reserve--of which it is estimated 700 were available for instant service. During the period of mobilisation a further 450 machines were added to the fleet, drawn for the most part from private owners. So far as the dirigibles were concerned 14 Zeppelins were ready for duty, while others were under construction or undergoing overhaul and repair. A few other types were also in commission or acquired during mobilisation, bringing the dirigible force to 40 machines all told. But the greatest surprise was probably offered by Russia. Very little was known concerning Russian activities in this particular field, although it was stated that large orders for machines had been placed with various foreign manufactories. Certain factories also had been established within the Empire, although the character of their work and its results and achievements were concealed from prying eyes. In Russia, however, an appreciable number of private aeroplanes were in operation, and these, of course, were placed at the disposal of the authorities the moment the crisis developed. The British and French aeroplane manufacturers had been busy upon Russian orders for many months previous to the outbreak of hostilities, while heavy shipments of component parts had been made, the assembling and completion of the machines being carried out in the country. It is generally believed that upon the outbreak of war Russia had a fleet of 800 aeroplanes in hand, of which total 150 were contributed from private sources. Even the dirigible had not been overlooked, there being nearly 20 of these craft attached to the Russian Army, although for the most part they are small vessels. In comparison with the foregoing large aerial navies, that of Great Britain appeared to be puny. At the moment Great Britain possesses about 500 machines, of which about 200 are waterplanes. In addition, according to the Secretary of the Admiralty, 15 dirigibles should be in service. Private enterprise is supported by the Government, which maintains a factory for the manufacture of these craft. During the two years preceding the outbreak of war the various Powers grew remarkably reticent concerning the composition and enlargement of their respective aerial fleets. No official figures were published. But at the same time it is a well-known fact that during the year 1913 France augmented her flying force by no fewer than 544 aeroplanes. Germany was no less energetic, the military acquisition in this branch, and during the self-same year, approaching 700 machines according to the semi-official reports published in that country. The arrangements concluded for the manufacture of additional craft during the war are equally remarkable. The principal factory in Germany, (now devoting its energies to the production of these craft, although in happier days its normal complement of 4,000 men were responsible for the production of another commercial article) possesses facilities for turning out 30 complete aeroplanes per week, according to the statement of its managing director. But it is averred that this statement is purposely misleading, inasmuch as during the first fortnight of the campaign it was producing over 50 aeroplanes per week. It must be remembered that Germany is responsible for the supply of the majority of such craft for the Austrian armies, that country purchasing these vessels in large numbers, because in the early days of the conflict it was notoriously weak in this arm. Since the declaration of war strenuous efforts have been made to remedy this state of affairs, particularly upon the unexpected revelation of Russia's aerial strength. It is computed that upon the outbreak of war the various Powers were in the position to show an aggregate of 4,980 aircraft of all descriptions, both for active service and reserve. This is a colossal fleet, but it serves to convey in a graphic manner the importance attached to the adrial vessel by the respective belligerents. So far as Germany is concerned she is sorely in need of additional machines. Her fleet of the air has lost its formidable character, owing to the fact that it has to be divided between two frontiers, while she has been further weakened by the enormous lengths of the two battle-fronts. Russia has been able to concentrate her aerial force, which has proved of incalculable value to the Grand Duke Nicholas, who has expressed his appreciation of the services rendered by his fliers. The French likewise have been favoured by Fortune in this respect. Their aerial navy is likewise concentrated upon a single frontier, although a pronounced proportion has been reserved for service upon the Mediterranean sea-board for co-operation with the fleet. France suffers, however, to a certain degree from the length of her battle-line, which is over 200 miles in length. The French aerial fleet has been particularly active in the Vosges and the Argonne, where the difficult, mountainous, and densely wooded country has rendered other systems of observation of the enemy's movements a matter of extreme difficulty. The Germans have laboured under a similar handicap in this territory, and have likewise been compelled to centre a considerable proportion of their aerial fleet upon this corner of the extended battlefield. It is in this region that the greatest wastage has been manifest. I have been informed by one correspondent who is fighting in this sternly contested area, that at one time a daily loss of ten German machines was a fair average, while highwater mark was reached, so far as his own observations and ability to glean information were concerned by the loss of 19 machines during a single day. The French wastage, while not so heavy upon the average, has been considerable at times. The term wastage is somewhat misleading, if not erroneous. It does not necessarily imply the total loss of a machine, such as its descent upon hostile territory, but includes damage to machines, no matter how slight, landing within their own lines. In the difficult country of the Vosges many aeroplanes have come to earth somewhat heavily, and have suffered such damage as to render them inoperative, compelling their removal from the effective list until they have undergone complete overhaul or reconstruction. Upon occasions this wastage has been so pronounced that the French aviators, including some of the foremost fliers serving with the forces, have been without a machine and have been compelled to wait their turn. I am informed that one day four machines, returning from a reconnaissance in force, crashed successively to the ground, and each had to be hauled away to the repair sheds, necessitating withdrawal from service for several days. Unfortunately the French, owing to their decision to rule out certain machines as unsuited to military service, have not yet perfected their organisation for making good this wastage, although latterly it has been appreciably reduced by greater care among the aviators in handling their vessels. The fast vessels of the French aerial fleet have proved exceptionally valuable. With these craft speeds of 95 and 100 miles or more per hour have been attained under favourable conditions, and pace has proved distinctly advantageous, inasmuch as it gives the French aviators a superiority of about 40 per cent over the average German machine. It was the activity and daring of the French fliers upon these high speed machines which induced the German airmen to change their tactics. Individual effort and isolated raiding operations were abandoned in favour of what might be described as combined or squadron attack. Six or eight machines advancing together towards the French lines somewhat nonplussed these fleet French mosquito craft, and to a certain degree nullified their superiority in pace. Speed was discounted, for the simple reason that the enemy when so massed evinced a disposition to fight and to follow harassing tactics when one of the slowest French machines ventured into the air. It is interesting to observe that aerial operations, now that they are being conducted upon what may be termed methodical lines as distinct from corsair movements, are following the broad fundamental principles of naval tactics. Homogeneous squadrons, that is, squadrons composed of vessels of similar type and armament, put out and follow roughly the "single line ahead" formation. Upon sighting the enemy there is the manoeuvring for position advantage which must accrue to the speedier protagonist. One then, witnesses what might almost be described as an application of the process of capping the line or "crossing the 'T.'" This tends to throw the slower squadron into confusion by bending it back upon itself, meanwhile exposing it to a demoralizing fire. The analogy is not precisely correct but sufficiently so to indicate that aerial battles will be fought much upon the same lines, as engagements between vessels upon the water. If the manoeuvres accomplish nothing beyond breaking up and scattering the foe, the result is satisfactory in as much as in this event it is possible to exert a driving tendency and to force him back upon the lines of the superior force, when the scattered vessels may be brought within the zone of spirited fire from the ground. Attacks in force are more likely to prove successful than individual raiding tactics, as recent events upon the battlefield of Europe have demonstrated more or less convincingly. An attack in force is likely to cause the defenders upon the ground beneath to lose their heads and to fire wildly and at random, with the result that the airmen may achieve their object with but little damage to themselves. This method of attacking in force was essayed for the first time by the British aerial fleet, which perhaps is not surprising, seeing that the machines are manned and the operations supervised by officers who have excelled in naval training, and who are skilled in such movements. No doubt this practice, combined with the daring of the British aviators, contributed very materially to the utter demoralisation of the German aerial forces, and was responsible for that hesitancy to attack a position in the vicinity of the British craft which became so manifest in the course of a few weeks after the outbreak of hostilities. One of the foremost military experts of the United States, who passed some time in the fighting zone, expressed his opinion that the British aerial force is the most efficient among the belligerents when considered as a unit, the French flier being described by the same authority as most effective when acting individually, owing to personal intrepidity. As a scout the French aviator is probably unequalled, because he is quick to perceive and to collect the data required, and when provided with a fast machine is remarkably nimble and venturesome in the air. The British aviators, however, work as a whole, and in the particular phases where such tactics are profitable have established incontestable superiority. At first the German aerial force appeared to possess no settled system of operation. Individual effort was pronounced, but it lacked method. The Germans have, however, profited from the lessons taught by their antagonists, and now are emulating their tactics, but owing to their imperfect training and knowledge the results they achieve appear to be negligible. The dirigible still remains an unknown quantity in these activities, although strange to relate, in the early days of the war, the work accomplished by the British craft, despite their comparatively low speed and small dimensions, excelled in value that achieved by the warplanes. This was particularly noticeable in matters pertaining to reconnaissance, more especially at night, when the British vessels often remained for hours together in the air, manoeuvring over the hostile lines, and gathering invaluable information as to the disposition and movements of the opposing forces. But it is probably in connection with naval operations that the British aerial fleet excels. The waterplanes have established their supremacy over the naval dirigible in a striking manner. British endeavour fostered the waterplane movement and has carried it to a high degree of perfection. The waterplane is not primarily designed to perform long flights, although such may be carried out if the exigencies demand. The practice of deputing certain vessels to art as "parent ships" to a covey of waterplanes has proved as successful in practice, as in theory. Again, the arrangements for conveying these machines by such means to a rendezvous, and there putting them into the water to complete a certain duty, have been triumphantly vindicated. At the time this idea was embraced it met with a certain degree of hostile criticism: it was argued that the association of the two fighting, machines would tend towards confusion, and impair the efficiency of both. Practice has refuted this theory. The British aerial raids upon Cuxhaven and other places would have been impossible, and probably valueless as an effective move, but for the fact that it was possible to release the machines from a certain point upon the open sea, within easy reach of the cooperating naval squadron. True, the latter was exposed to hostile attack from submarines, but as results proved this was easy to repel. The aircraft were enabled to return to their base, as represented by the rendezvous, to be picked up, and to communicate the intelligence gained from their flight to the authorities in a shorter period of time than would have been possible under any other circumstances, while the risk to the airmen was proportionately reduced. The fact that the belligerents have built up such huge aerial navies conclusively proves that the military value of the Fourth Arm has been fully appreciated. From the results so far achieved there is every indication that activity in this direction will be increased rather than diminished. 
40170	----	Transcriber's note: Text in italics has been marked with underscores (_text_). Further Transcriber's Notes will be found at the end of this text. THE ROMANCE OF AIRCRAFT [Illustration: _Copyright Underwood and Underwood_ SEAPLANES NC-1, NC-3 AND NC-4 OF THE U. S. NAVY STARTING THE TRANS-ATLANTIC FLIGHT FROM ROCKAWAY] [Illustration: _Copyright Underwood and Underwood_ THE NC-4 ON ITS VICTORIOUS TRANS-ATLANTIC FLIGHT, SIXTY MILES AT SEA. THE SHADOW IS MADE BY A STRUT OF THE PHOTOGRAPHERS' PLANE] THE ROMANCE OF AIRCRAFT BY LAURENCE YARD SMITH _WITH SIX DIAGRAMS AND THIRTY-THREE ILLUSTRATIONS FROM PHOTOGRAPHS_ LONDON GRANT RICHARDS, LTD. ST. MARTIN'S STREET MDCCCCXIX PRINTED IN THE UNITED STATES OF AMERICA BY THE PROSPECT PRESS CONTENTS PART I CHAPTER PAGE I THE CONQUEST OF THE AIR 3 II "A B C'S" OF A BALLOON 14 III EARLY BALLOON ADVENTURES 20 IV THE PARACHUTE 28 V BALLOONING IN THE GREAT WAR 36 PART II I DEVELOPMENT OF THE DIRIGIBLE 47 II FORERUNNERS OF THE ALLIED DIRIGIBLES 60 III DIRIGIBLES IN THE WORLD WAR 68 PART III I EARLY EXPERIMENTS WITH HEAVIER-THAN-AIR MACHINES 77 II FIRST PRINCIPLES OF AN AIRPLANE 91 III THE PIONEERS 99 IV THE AIRPLANE IN THE WORLD WAR 128 V SOME OF THE PROBLEMS THE INVENTORS HAD TO SOLVE 150 VI FAMOUS ALLIED AIRPLANES 170 VII GERMAN AIRPLANES IN THE WORLD WAR 189 VIII HEROES OF THE AIR 205 IX THE BIRTH OF AN AIRPLANE 223 X THE TRAINING OF AN AVIATOR 232 XI THE FUTURE STORY OF THE AIR 244 READING LIST 256 INDEX 259 LIST OF ILLUSTRATIONS Seaplanes NC-1, NC-3 and NC-4 of the U. S. Navy starting the trans-Atlantic flight from Rockaway. The NC-4 on its victorious trans-Atlantic flight, sixty miles at sea _Frontispiece_ FACING PAGE Montgolfier experiment at Versailles, 1783 10 The first cross-channel trip 11 Diagram showing the main features of the spherical balloon 16 Cocking's parachute 30 A German Zeppelin 31 Inflating a service balloon on the field 40 Army balloon ready to ascend 41 Giffard's airship 54 Santos-Dumont rounding the Eiffel Tower 55 Baldwin U. S. "Dirigible No. 1" 66 The British Army "Baby" dirigible 67 Cross section of the gas bag of the _Astra-Torres_, showing method of car suspension 70 "The Blimp," C-1, the largest dirigible of the American Navy 72 The balloon of the _U. S. S. Oklahoma_ 73 Diagram showing the essential parts of an airplane 95 Wright starting with passenger 98 An early Farman machine prior to start 99 Wright machine rising just after leaving the rail 114 An early Wright machine, showing its method of starting from a rail 114 The propeller department in one of the great Curtiss factories 115 A photograph of northern France taken at a height of three thousand feet 138 An airplane view of the city of Rheims, showing the cathedral 139 Diagram of an internal combustion engine cylinder, showing principle on which it works 157 This photograph shows the relative size of the giant Caproni bombing plane and the French baby Nieuport, used as a speed scout 170 The Spad, the pride of the French air fleet 171 A Handley-Page machine tuning up for a flight 182 The launching of a Langley, a giant bombing airplane 183 Side view of a Sopwith triplane 187 An American built Caproni airplane 188 This Curtiss triplane has a speed of one hundred and sixty miles an hour 189 A giant Gotha bombing plane brought down by the French 198 German Fokker plane captured by the French 199 Captain Eddie Rickenbacker 218 The first bag of mail carried by the U. S. Aero Mail Service 219 A photograph made ten thousand feet in the air, showing machines in "V" formation at bombing practise 242 A group of De Havilland planes at Bolling Field near Washington 243 PART I THE ROMANCE OF AIRCRAFT CHAPTER I THE CONQUEST OF THE AIR On a beautiful afternoon in the latter part of the eighteenth century--June 5, 1793--a distinguished company of Frenchmen were gathered in the public square of the little village of Annonay, not far from Lyons. They had come there by special invitation of the brothers Stephen and Joseph Montgolfier, respected owners of a paper manufactory in the little town. It was whispered that the brothers had a great surprise in store for them, a remarkable discovery. Yet all their curious gaze could make out was a great linen bag, that swung, like a huge limp sail, from a rope that was suspended between two high poles. By means of this seemingly helpless piece of fabric the brothers Montgolfier proposed to accomplish the conquest of the air. Those who ventured near to this strange object perceived at its base a wide circular opening, sewed fast to a wooden ring. The ring hung directly over a deep pit, in which had been heaped fuel for a bonfire,--straw and wood and chopped wool. At a given signal one of the brothers applied a torch to the mass and in an instant the flames shot up. A dense column of smoke arose through the neck of the bag. The latter gradually began to fill, spreading out in all directions, until, before the astonished gaze of the spectators, it assumed the shape of an enormous ball, that overshadowed the square, and that pulled and wrestled feverishly at the restraining ropes. From the ranks of the onlookers a great shout of applause went up. The keepers let go the ropes, and the globe, like a live creature, freed from its bonds, rose triumphantly before their eyes. Up, up, higher and higher it went, so fast that they could scarcely follow it. For a moment it was hidden behind a patch of cloud, then it reappeared again, still ascending, until it rode majestically in the heavens, seven thousand feet above their heads! The shouts and cries of the onlookers were deafening. Like wildfire the news spread from house to house of the little French village. Grave old legislators who had witnessed the surprising spectacle forgot their dignity and tossed their hats in air. Women, seeing the unusual object from a distance, fell on their knees to pray, thinking it a sign in the heavens, that portended, who knew what? Man's age-old dream of conquering the air was now, for the first time, an accomplished fact. Those who stood in the little public square of Annonay on that auspicious afternoon long ago, watching the first Montgolfier globe on its victorious ascent, knew that it could be but a very short time indeed until men would be able to explore at will the dim regions of the upper air. Meanwhile picture the consternation and terror among a group of humble peasants, who were tilling the fields a short distance from the spot where the famous Montgolfier balloon was launched. Suddenly in the sky there appeared a great black moon, which slowly and ominously descended toward the earth. The village priest himself led forth a little band of his stout-hearted followers to attack this dread instrument of the Evil One. With pitchforks and scythes they rushed upon the unfortunate balloon as it lighted gently on the ground, heaving this way and that with every puff of breeze that blew against it. With courage born of fear they prodded and beat the unfortunate monster. When the gas had finally escaped through the great gashes in its sides, and nothing remained but a disordered heap of tatters and shreds, the proud "conqueror of the skies" was tied fast to a horse's tail, and the terrified creature galloped off with it into the open country. But the news of the Montgolfier brothers' discovery spread throughout the length and breadth of France and the civilized world. The French king ordered a special demonstration at Versailles, before himself and the Royal family. On this occasion a wicker basket was swung from the richly ornamented balloon. In order to test the safety of travel in the skies there were placed in it a sheep, a cock and a duck. A fire was lit beneath the base of the balloon and it was filled with heated air. It rose with its strange cargo to a height of 1500 feet, traveled along peacefully two miles with the breeze and descended slowly into a near-by wood. There two gamekeepers, hurrying to the scene, were amazed to find its occupants calmly feeding, apparently unaffected by their voyage. This incident gave the experimenters renewed courage and enthusiasm. A gallant Frenchman, Pilâtre de Rozier, volunteered to be the first man to make the ascent into the skies. A new and stronger machine was constructed, this time oval in shape instead of round, 74 feet high and 48 feet in diameter. At the bottom was a huge circular opening, 15 feet across. Just beneath this there was swung from iron chains an open grate, on which the fire was built by means of which the balloon was inflated. This grate hung down into a wicker basket or "gallery," in which the occupant stood, heaping fuel upon the fire. For of course, as soon as the fire died down, the heated air in the balloon commenced slowly to escape, and the whole thing sank to earth. Pilâtre de Rozier was not at first permitted to set himself free and go voyaging unguarded into the upper air. Who knew whether this air above the clouds was fit to breathe?--who, for that matter, knew whether there actually _was_ air at any distance above the surface of the earth? It was considered the better part of valor to try the experiment the first few times with the balloon tied firmly to the ground, with strong cables which only permitted it to rise some eighty or ninety feet. Even with these precautions a good deal of apprehension was felt regarding the healthfulness of the sport. But a sigh of relief was breathed by those who had the undertaking in charge when the bold de Rozier insisted that never in his life before had he known any experience so pleasurable as this of rising far above the housetops and of feeling himself floating, gently and peacefully, in a region of noiseless calm. Impatient of this mild variety of aerial adventure, de Rozier finally won permission to make a "free" ascent, and he and his friend, the Marquis d'Arlandes, made a number of daring voyages in the Montgolfier fire balloon. Assuring their friends that no harmful results could come to them from ascending into the clouds, they loosed the ropes and went merrily sailing away until far out of sight. So long as they kept the fire in the grate burning the balloon remained aloft, and floated along in the direction in which the wind bore it. When they wished to descend they had merely to put out the fire, and as the heated air gradually escaped, the balloon sank gently to earth. But the dangers of this sort of aerial adventure were very great indeed, and it required the most remarkable heroism on the part of de Rozier to undertake them. A chance spark from the grate might at any moment set fire to the body of the balloon, and bring it, a flaming firebrand, to earth. De Rozier understood this, and on his very first voyage carried along in the gallery of the balloon a bucket of water and a sponge. It was late in November of 1893 that he and d'Arlandes floated over Paris,--de Rozier heaping fuel upon the grate and tending the fire which kept the balloon afloat. Suddenly d'Arlandes heard a slight crackling noise high in the balloon. Looking up he caught a sight which turned him cold with horror,--a tiny licking flame far above his head. He seized the wet sponge and reached up to extinguish it. But another and yet another appeared, little tongues of fire, eating away at the body of the balloon. As each showed its face water was dashed upon it. From below the balloon could be seen peacefully journeying across the city. But far above, in its basket, de Rozier and d'Arlandes were coolly beating off the danger that hung over them like a Sword of Damocles. Not until they had been in the air twenty-five minutes, however, did they put out the fire in the grate and allow themselves to sink to earth. These early experiments of the Montgolfiers and de Rozier fired the imaginations of scientific men in every part of the world, and it was only a very short time before a safer and more reliable type of balloon than the fire balloon was developed. Stephen Montgolfier's invention was based on the idea that smoke and clouds rise in the atmosphere. "If," said he to himself, "it were possible to surround a cloud with a bag which did not permit it to escape, then both would ascend." Of course this was a rather childish explanation of the cause of a balloon ascension, but it was the best that the Montgolfiers or any of their learned friends knew at that early day. Now it was only a little while before this that an Englishman had discovered the gas which is now known as hydrogen, but which was then called "inflammable air." This gas, of which the Montgolfiers apparently knew nothing, is exceedingly light, and therefore rises very quickly in the air. The year before the Montgolfier balloon was invented, this Englishman, Cavallo, tried to fill small bags with hydrogen gas, on the theory that they would rise in the atmosphere. He failed merely because he did not hit upon the proper material of which to construct his bags. The fabric he chose was porous, and the gas escaped through it before the balloon could rise. Cavallo did, however, succeed in blowing hydrogen into ordinary soap bubbles, which arose with great velocity and burst as they struck the ceiling. The problem of the material to be used in balloon construction had been fairly well solved by the Montgolfiers. Their balloons were of linen fabric, varnished and lined with paper, to render them as nearly as possible air-tight. This set the philosophers of Paris thinking how they might construct a globe which could be successfully inflated with hydrogen. The brothers Roberts and M. Charles made the first hydrogen balloon. It was fashioned of very fine silk, varnished with a solution of gum elastic. This made it impossible for the hydrogen to leak through. The balloon was filled through an opening in the neck, which was fitted with a stopcock, so that the gas could be poured in or allowed to escape at will. The funds for constructing this first hydrogen balloon had been raised by popular subscription, and the whole French people were alive with enthusiasm over the success of the experiment. Even at that early day France was the ardent champion of aerial conquest. The day set for its ascension was the 27th of August, 1783. By the night of the 26th it had been partially filled with gas. It was tied to a cart, and long before daylight, started its journey to the Field of Mars. Throngs of spectators crowded every avenue. From the roof tops thousands of eager men, women and children peered down upon it through the darkness. Every window in every building was crowded with faces. A strong military guard surrounded it, riding on horseback and carrying flaring torches. All day long multitudes crowded and jostled each other impatiently at the point where the ascension was to take place. At five o'clock in the afternoon the sudden booming of artillery fire gave notice to the hundred thousand waiting that the great event was on. Released from its bonds the balloon shot up, and in two minutes it was over 3,000 feet above the heads of the watchers. Still it continued steadily to rise, until finally it was lost to sight by the heavy storm clouds through which it had cut its passage. [Illustration: MONTGOLFIER EXPERIMENT AT VERSAILLES, 1783] [Illustration: THE FIRST CROSS-CHANNEL TRIP] The spectators were overjoyed, as on that first occasion when the Montgolfier balloon rose into the skies. It was pouring rain, but they did not seem to notice it as they cheered themselves hoarse at the second great air victory. The balloon, likewise, was undiscouraged by the rain. Far above the clouds, where all was quiet sunshine, it journeyed peacefully along for fifteen miles, and descended in an open field. The first two important chapters in the history of ballooning had now been written. Looking back, we are filled with gratitude to the French, whose courage, intelligence, and boundless enthusiasm made possible the conquest of the skies. In other countries, of course, experiments were also in progress, though they lacked to a great extent the popular backing which helped the French efforts to bear such splendid results. In London, an Italian, Count Zambeccari, constructed a hydrogen balloon of oil silk, 10 feet in diameter and _gilded_, so that in the air it was dazzling to look upon. A few months after the three Frenchmen launched their hydrogen balloon in Paris, this gorgeous affair was sent up in London, in the presence of thousands of spectators. One month later still, the city of Philadelphia witnessed the first ascension of a hydrogen balloon in the New World. It carried a carpenter, one James Wilcox, as passenger. "What is the use of a balloon, anyway?" Benjamin Franklin was asked when in Paris at the time of the Montgolfier experiments. "What is the use of a baby?" the great American replied, smiling. Perhaps he had some inkling of the remarkable future in store for the science of aeronautics, then in its infancy! The first really notable ascent in a hydrogen balloon after the early efforts was that of a Frenchman, M. Blanchard, who rose from Paris in 1784, accompanied by a Benedictine monk. Before they had got far above the ground a slight accident brought the balloon bumping down again. The monk, thoroughly scared, abandoned his seat, and M. Blanchard ascended alone. This balloon was fitted out with wings and a rudder, by which it was hoped to steer its course, but they proved useless, and its occupant had to allow himself to drift with the wind. He reached a height of 9600 feet, remaining in the air an hour and a quarter. Suffering from the extreme cold which is experienced so high in the atmosphere, and almost overcome with numbness and drowsiness, he was at length compelled to descend. In England at about this time, Vincent Lunardi accomplished a free ascent in the presence of the Prince of Wales. But again it was the Frenchman, M. Blanchard, who succeeded in making the first _long_ balloon voyage. In January, 1785, he and Dr. Jeffries, an American physician, sailed across the English Channel from Dover. It was a perilous adventure, with the ever present danger of falling into the sea. Half way across they found themselves descending. Then began a constant throwing out of ballast in a race with time and the wind. When the bags of sand they had brought for the purpose were exhausted they hurled overboard bottles, boxes, pieces of rope, even their compass and the apparatus of the balloon. They were still falling when in the distance they caught sight of the dim outline of the French coast, and in a last effort to keep afloat they began dropping articles of clothing over the basket's edge. Suddenly, however, the balloon began to mount. They floated in over the land, coming to earth safely not far from Calais. Pilâtre de Rozier at once set about to imitate M. Blanchard's feat, and to avoid the danger of falling he constructed a hydrogen balloon with a fire balloon below it, so that by heaping on fuel he could force it to rise whenever he noticed a tendency to fall. In this ingenious contrivance he attempted to fly the Channel. At a height of 3,000 feet both balloons were seen to burst into flames, and de Rozier fell. So the gallant Frenchman who was first to explore the skies came to his unfortunate end. His death cast a gloom over the many aeronautic enthusiasts of France, England and America. But his splendid pioneer exploits had borne their fruit in a permanent and growing interest in the navigation of the air. The science of aeronautics marched on, and new and important schemes were invented for conquering the skies. CHAPTER II "A B C'S" OF A BALLOON Why does a balloon rise in the atmosphere?--is the very natural question we are apt to ask as we read the story of these early balloon experiments. The Montgolfier brothers themselves could probably not have answered it, for they claimed that some marvelous secret properties existed in "Montgolfier smoke." Stephen Montgolfier seems to have had the idea of "holding a cloud captive in a bag," since he had observed that clouds rise in the air. The real explanation can best be understood by a simple experiment. Throw a stone into a pool of water and it will sink, because it is "heavier than water": that is, it weighs more in proportion to its volume than the same quantity of water weighs. But throw into the same pool a piece of cork and it will rise, because it is lighter in proportion to its volume than water. This truth was long ago expressed as a law by the old Greek philosopher Archimedes, who said: "_Every body immersed in a liquid loses part of its weight, or is acted upon by an upward force equal to the weight of the liquid it displaces._" In the case of the cork, the weight of the water it displaces is greater than the weight of the cork, and consequently the upward force acting upon it is sufficient to lift it to the surface of the pool; but with the stone it is different: the water it displaces weighs _less_ than the stone, and therefore the upward force acting upon it is not sufficient to prevent it from sinking. Now all this applies just as well to a body in the atmosphere as it does to the body immersed in water. The air in this case corresponds to the liquid. Therefore any object placed in the air which weighs less in proportion to its volume than the atmosphere, is bound to rise. Every object we see about us, including ourselves, which is not fastened down to earth, would, if it were not "heavier than air," go flying off toward the skies. Imagine a balloon all ready to be inflated, that is, ready to be filled with gas. The bag or "envelope" hangs limp and lifeless. Together with the basket, ropes, etc., which are attached to it, it probably weighs several hundred pounds, yet because its _volume_ is so small it displaces very little air. Now we commence to inflate the balloon. As the gas rushes in, the envelope commences to swell; it grows larger and larger, displacing a greater volume of air every moment. When fully inflated it displaces a volume of air much greater in weight than itself. This weight of displaced air acts upon it with a resistless upward force, sufficient to lift it into the clouds. The moment its straining bonds are loosed, it rises with great velocity. Of course, the lighter the gas that is used to inflate the balloon, the less weight will be added by it to the total weight of the structure,--although a lighter gas adds just as much to the volume as a heavier one would do. If two balloons of exactly the same weight before inflation are filled, one with the comparatively heavy coal gas which weighs 1/2 oz. per cubic foot, and the other with the very light hydrogen, which weighs 1/10 oz. per cubic foot, it is easy to see that the hydrogen-filled balloon will rise much faster and have a greater lifting power. It is a simple matter to calculate what size balloon will be required to lift one, two or three passengers and a given weight of cargo, for we know that the balloon envelope must be large enough when filled with gas, to displace a greater weight of air than its own weight, together with the weight of the basket, equipment, passengers and cargo. Once a balloon has been inflated and begun to ascend it would, if unchecked, continue rising indefinitely until it reached a point in the greatly rarefied upper air where it was exactly displacing its own weight, or, as science puts it, was "in equilibrium with the air." But this is usually not desirable, and so in all modern balloons arrangement is made for lessening the volume of the envelope and so decreasing the upward pressure. This is managed from the basket by pulling a cord which connects with a valve at the top and thus allows some of the gas to escape. There is also a valve in the neck of the balloon which opens automatically when the pressure becomes too great, or which can be operated by a cord. In addition to these two, balloons to-day have what is known as a "_ripping panel_," or long slit closed over with a sort of patch or strip of the envelope material. In case it becomes necessary to make a quick descent, the ripping panel may be torn open by pulling the cord which connects with this ripping strip. A wide rent is thus produced in the envelope and the gas escapes very rapidly. As the balloon becomes deflated (that is, loses its gas), it grows smaller, displaces less and less air, and so sinks to the earth. [Illustration: DIAGRAM SHOWING THE MAIN FEATURES OF THE SPHERICAL BALLOON] The accompanying diagram gives a very good idea of the main features of the spherical balloon. The envelope is usually made of strong cotton diagonal cloth, cut in pear shaped gores and varnished with a solution of rubber in order to prevent the gas from leaking through. At the bottom it ends in the long _neck_,--through this the balloon is inflated by joining it securely to a gas pipe which leads to the main supply of gas. Over the envelope there is spread a strong _net_ made of heavy cord. From the net hang the stout _leading lines_. The leading lines in turn are attached to a strong wooden _hoop_, and from this hoop the car is suspended by ropes which are called _car lines_. The cords that connect with the upper and lower valves and the ripping panel hang down into the car and may be operated by the occupants, or crew. Unless the balloon is held captive it is supplied also with a _trail rope_. This is a very heavy cable which is allowed to hang down from the car during an ascent. When descending, as the trail rope reaches the ground the balloon is relieved of a portion of its weight and becomes more buoyant. This makes its descent more gradual, for as it is relieved of one pound of weight of the dragging trail rope, it gains a slight tendency to rise again which counteracts the severity of its downward motion. The free balloon also has a _grapnel_ or anchor for use in landing. The _car_ or _basket_ of the balloon is usually made of woven willow and bamboo, which insures strength and lightness. This brief description of the spherical balloon is intended to give the reader an idea of the essential features of any balloon. In modern warfare the captive balloon has proved its usefulness for purposes of observation, but the old spherical type is passing out. Balloons of many shapes and sizes, all designed for greater stability, are taking its place. Among these the "kite" or "sausage" balloon is by far the best known. Partly a kite and partly a balloon, with its long sausage-shaped body, its air-rudder or small steering ballonet attached to its stern, it possesses considerable "steadiness" in the air. The kite balloon is used over the trenches to direct artillery fire and to report movements of the enemy: and it is likewise used over the sea, as a guide to direct the movements of the fleet in an attack, and as a sentinel on the look-out for enemy ships or submarines. CHAPTER III EARLY BALLOON ADVENTURES No sooner had the news of the remarkable balloon exploits of de Rozier and Blanchard spread throughout the nations, than people of all classes became interested in the future of ballooning. There were those who regarded it as the great coming sport, and there were also those who, like the French military authorities, saw in this new invention a possible weapon of war whose development they dared not neglect. It was only a short time before the French had an army training school for aeronauts, and a number of military service balloons. The romance of ballooning had captured the imaginations of great masses of people and they proved their eagerness to back up the efforts of sportsmen balloonists with the necessary funds to carry on the many aeronautic projects which were suggested. We have already mentioned Chevalier Vincent Lunardi, the young Italian who was the first to accomplish a voyage in a balloon in England. The English people had read with ever increasing curiosity and impatience the stories of the French balloonists. What was their delight when this young Italian, poor but clever, proposed to give them an exhibition of their own. He had little difficulty in obtaining permission for a start to be made from London. The next step was to obtain funds by popular subscription for the construction of the balloon. For a time money flowed freely into the coffers; but a Frenchman named Moret came into the limelight as a rival of Lunardi and announced a balloon ascent some little time before that planned by his opponent. The demonstration promised by Moret never came off, his balloon refused utterly to take to the air, and the indignant spectators went home, feeling that they had been cleverly hoodwinked out of the price of admission. Their wrath naturally turned upon the unfortunate Lunardi, and it was only with difficulty and after much discouragement that he actually succeeded in carrying his undertaking to completion. Finally, however, he had his balloon built. The King had withdrawn his permission for a flight from the grounds of the Chelsea hospital, but he succeeded in securing another starting place, and announced that he was ready to demonstrate what the balloon could do. Vast crowds gathered to witness the spectacle. The balloon itself was gorgeous to behold. It looked like a mammoth Christmas-tree ball, of shining silk, in brilliant stripes of red and blue. It was filled with hydrogen gas, and as it gradually took form before their eyes, the people shouted with excitement and eagerness. It was a pleasant September afternoon in the year 1784. When all was in readiness, Lunardi, no less eager and excited than the masses who had gathered to witness his exploit, climbed into the car. The cords were loosed and in a few moments the balloon, in its gala dress, was soaring far in the sky. Lunardi enjoyed his flight immensely. After traveling along without a mishap for a considerable time, he decided to come down, but once he had touched the earth he was seized by the desire to soar again. Putting out some of his ballast he allowed the balloon to arise once more into the sky. Finally in the late afternoon he came to earth for the second time, landing in a field and greatly terrifying the simple country folk who were at work there. He was cold and hungry after his long journey in the rarefied upper air, but happy at the remarkable triumph he had achieved. Henceforth ballooning would not be regarded with derision and unbelief in England. The English nation was as wild with joy as the French had been at the early balloon ascents. Lunardi was lionized and became the favorite of the hour; his presence was demanded everywhere and he was royally entertained by the foremost people of the realm. The British Isles became, from this time on, the scene of many a thrilling adventure with the balloon. It was only a few years later that Charles Green, the most famous of all the early English aeronauts, began his voyages in the _Great Nassau_, the balloon whose name is even to-day a tradition. In it he started out, one fall day in the year 1836, carrying provisions for a long voyage, but with no idea where the winds would carry him. The great balloon passed out over the British Channel and in again over the coast of France. Day faded into twilight and twilight into the blackness of night, but still it continued steadily on its way. Through the darkness Green and the friends who accompanied him in the large car of the balloon peered anxiously over the side, trying to guess where they were being blown. Finally after an all night ride, the dawn began to break, and in the morning the great balloon was brought to earth on German territory. Green had accomplished the longest balloon trip of his day. In the years that followed he made many voyages, but none that won for him more renown than this one. Since the days when Blanchard accomplished the first trip across the British Channel, and the fearless de Rozier sought to imitate him, a number of aeronauts had made interesting voyages between France and England. One of the most adventurous was that of Mr. C. F. Pollock, in July, 1899. Accompanied by a friend, Mr. Pollock ascended early one afternoon, and after a picturesque and beautiful trip across the English countryside, sailed out over the sea. Behind them rose the white cliffs of the English coast, while before them gathering clouds hung like a curtain, through which they peered anxiously. Suddenly the balloon began to fall, and, fearful lest they should land in the rough waters of the channel, they began throwing overboard the sand which they had carried along as ballast. By means of this they succeeded in rising once more to a height of seven or eight thousand feet. It was early evening. Far below the sea had ceased to roar. They floated along in a realm of silence where nothing was visible through the veil of mist. At length the veil was broken by the dim outline of the French coast. On and on they drifted yet seemed to draw no closer to it. There it remained, always ahead of them, tantalizing and provoking. Their ballast was almost gone, and they had unpleasant visions of landing in the water within view of their goal. So calmly and evenly did the balloon move forward that it was practically impossible for its occupants to tell whether it was moving at all. As they peered ahead uncertainly, searching the sea for a vessel by which they might gauge their progress, they felt themselves once more commencing to sink. In another few minutes the rest of the sand had been thrown overboard. There was nothing left with which to check the falling of the balloon, which surely and ominously continued. The French coast was still many miles away. Almost in despair the two aeronauts cast about them for something which could be hurled over the side to lighten the weight of the balloon. As a last measure they decided upon the anchor. In another moment they had tossed it into the sea. Relieved of so great a weight the balloon shot up with lightning speed. The coast was drawing closer, but after its first swift ascent the balloon commenced to sink again and the aeronauts almost gave up hope of actually reaching shore. But just about eight o'clock they discovered to their great relief that the cliffs that marked the coast were below them. In another few minutes they had sailed in over the land. They opened the valve of the balloon and effected a descent in a field, where they were soon surrounded by an admiring circle of French peasants. It was only about ten years after the pioneer voyages of de Rozier that the balloon was actually used on the battlefield, for in 1794 the French employed it against the Austrians at Mayence and at Charleroi. Under the fire of the Austrians who sought to prevent him from ascending, the French Captain Coutelle rose in an observation balloon at Mayence to a height of over a thousand feet. At that height he was beyond the range of the Austrian guns and could sit at ease watching their movements and preparations, at the same time dropping communications to the officers below. By his pluck he made possible a French victory, although the Austrians, much chagrined at their own lack of observation balloons, declared that this sort of warfare was unfair. It may surprise Americans to know that balloons were used to good purpose for observation work in our own Civil War, and that they assisted the army of the North to keep an eye on the movements of Confederate troops around Richmond. They were once more employed by the French during the siege of Paris in 1870 and 1871, when 66 balloons left the city at various times, bearing messages, passengers, and flocks of carrier pigeons, which were used for delivering return messages. One plucky Frenchman dropped thousands of messages from his balloon upon the German soldiers, warning them of France's determination to fight to the bitter end. The incident reminds us somewhat of similar ones in the Great War, when the Allied aviators bombed the cities of Germany with proclamations. The first notable employment of the balloon by the British army occurred during the Boer War. During the siege of Ladysmith captive balloons were used to good purpose for observation and they were likewise made use of during a number of battles and under heavy fire. The French again employed them during the wars in Madagascar. Balloons had by the end of the nineteenth century become an important adjunct of every great army, and had proved themselves indispensable. Strange to relate they have never been driven from the field, and although we have to-day the swift dirigible and the still swifter airplane, there are certain military duties which they can perform best. While the balloon was thus becoming a recognized instrument of war it was likewise gaining in favor among sportsmen. In all the great nations Aero Clubs were formed and races and contests began to be announced. In 1906 Gordon Bennett made the offer of a Challenge Cup for the longest trip by balloon. The contestants were to start from Paris. On September 30th, 1906, sixteen balloons arose from the Tuileries Gardens and started on their way. An American, Lieutenant Frank P. Lahm, carried off the cup, accomplishing a total distance of 401 miles and landing in Yorkshire. The second race for the Gordon Bennett cup was held in America, and was won by a German. The third was held in 1908 in Germany. The winner, Colonel Schaeck, made a dangerous descent upon the sea near the coast of Norway, where he was rescued by a fishing boat. Several other contestants had perilous adventures. The American balloon _Conqueror_ exploded in mid-air, much to the excitement of the thousands of spectators who had gathered to witness the start of the race. Instead of crashing to earth, however, as they had expected, it sank down gently, the upper part of the envelope forming a parachute. The aeronauts made an amusing landing on a housetop, little the worse for their sudden drop of several thousand feet. Another American balloon landed in the branches of a tree, while several of the remaining contestants came down in the sea and were rescued. On the whole it was a thoroughly exciting race, and the news of it aroused intense enthusiasm for the sport of ballooning in many lands. CHAPTER IV THE PARACHUTE The story of the parachute is inevitably linked in memory with that of the balloon. Those who look back a few years can remember when exhibition balloons were in their heyday, and the sensation the parachutist used to create as he leapt from on high and came flying recklessly through the air. For a breathless moment or two the parachute remained folded, and when, finally, its umbrella-like form spread out protectingly above the hero, a thrill of relief ran through the anxious crowd of spectators. In the early days of ballooning the parachute was looked on as a sort of life belt the aeronaut might don in the event of a serious accident to his craft in mid-air. Many experimenters gave their attention to developing it for this purpose; but when it was found that the balloonist actually needed no protection, since the balloon itself would "parachute" to earth after an explosion, interest in the matter waned. To-day the parachute has come once more into prominence because of the heroic work it performed in connection with the kite balloon and with the airplane in the war, and so our concern in it has revived. Many stories reached us from the front, of artillery spotters who jumped to safety when their observation balloons were unexpectedly attacked by enemy airplanes. It has actually become the "life-belt of the air." More often in the early days of ballooning it was a source of grave danger to the plucky aeronaut who sought to try it out and improve it, and its history includes the record of several sad accidents. It was in the very year that the balloon was invented that a Frenchman, M. Le Normand began experimenting with a contrivance resembling an umbrella, with which he jumped from the branches of a tree, and sank gently to earth, the parachute saving him from injury. Successful as his first attempt was it seems that he afterward lost his nerve, and later attempts were made with animals placed in a basket below the parachute and dropped to earth from a considerable height. Blanchard, the famous balloonist, became interested in the idea of the parachute, and made a number of very interesting experiments. While making a public ascent in a balloon at Strasbourg, he dropped over the side of his balloon a dog with a parachute attached to him. The spectators were greatly pleased when the little creature came to earth quite unharmed, and public interest in the contrivance as a means of saving life was aroused. In 1793 Blanchard himself undertook to make a parachute descent. He was not wholly successful, for before he reached the earth the apparatus gave way and he crashed down heavily, fortunately escaping with nothing worse than a broken leg. In spite of his injury he did not give up the idea of the parachute as a "life belt" for the aeronaut, and looked forward to the time when it should be so improved that it could be relied upon to bring the aeronaut to earth uninjured if any accident should make it necessary for him to escape from his balloon in mid-air. However it was again a Frenchman, M. André Garnerin who accomplished the first descent by parachute from a great height without injury. His parachute was attached to a balloon. At a height of several thousand feet in the air, he freed himself and descended gradually, alighting gently upon the earth. That was in 1797 and five years later he gave a public demonstration of his parachute in England. This time he was not so successful, for his apparatus broke before he reached the ground and he received a number of injuries by his fall. The parachute actually saved a life, however, in 1808, when the aeronaut R. Jordarki Kuparanto, whose balloon caught fire in mid-air during a demonstration at Warsaw, leapt over the side with his parachute and came to earth unharmed. [Illustration: COCKING'S PARACHUTE] The parachute which Garnerin and the early aeronauts used in their experiments was fashioned to resemble an umbrella. As the aeronaut descended and the swift current of air caused by the fall rushed up under this canopy, it tended to hold it in the air much as the wind supports a kite, and thus the force of the descent was broken. In the year 1837 an Englishman named Cocking, who had been studying the principles of the parachute, came forward with an idea which differed greatly from this. The parachute he invented resembled an umbrella that had been blown inside out by the wind,--it was in other words an inverted cone, with a basket for the aeronaut hung from the cone's apex. The upper rim of the cone was made of tin to strengthen it, and the sides were of cloth. [Illustration: _Copyright Underwood and Underwood_ A GERMAN ZEPPELIN] Cocking was very enthusiastic over his invention, for he believed that his inverted parachute would descend more smoothly through the air than the old kind, which, while it supported the aviator, had a tendency to rock and pitch in the air after the manner of a kite. He sought an opportunity of giving his idea a public trial, but experienced aeronauts advised him not to do so, as they did not trust the safety of his apparatus. However, he insisted, and he finally persuaded the famous aeronaut Green to take him up. On July 24th, 1837, the famous experiment was made. Green ascended in the great Nassau balloon, with Cocking's parachute suspended beneath it. Thousands of spectators had gathered to watch the ascent, but as the balloon was carried away by the breeze it was finally lost to their view, and so they were spared witnessing the accident which followed. Green had been greatly worried over the safety of the parachute and had refused to free it from his balloon, but this difficulty Cocking had overcome by arranging a contrivance which permitted him to free himself when he thought the proper moment had arrived for his experiment. Finally, at a height of about 5000 feet, he called good-by to Green and let himself go. Relieved of his weight the balloon bounded up with great swiftness, and it was some time before it recovered its equilibrium. Meanwhile the parachute fell earthward with tremendous speed, rocking from side to side, until finally, unable to stand the strain any longer it went to pieces in the air, and the unfortunate parachutist came crashing to the ground. He died a few moments later. Cocking's death cast a gloom over parachute enthusiasts, and for some time the contrivance fell into disfavor. But the real reason for its disuse was that balloonists found they needed no "life belt," as the balloon itself, if for any reason an explosion should occur, would sink gently to earth, the upper portion of the envelope forming a natural parachute. So for a number of years the parachute was little heard of, except as a "thriller" at country fairs. In this connection it was always fairly popular. It was usually a folding umbrella parachute that the performer used on such occasions. As he leapt from the balloon he dropped straight down during a few terrifying seconds. Then to the relief of the spectators the parachute slowly and gracefully opened like a huge canopy over his head. From that moment his fall was checked and he sank gracefully and slowly to the earth. With the coming of the Great War the day of the parachute was revived. Greatly improved in construction it came into its true and important rôle as the "life-belt" of the aeronaut. The life of the balloon observer in war times is a precarious one. His balloon is not free but is held captive by heavy cables reaching to the ground below. Hour after hour he sits watching the situation over the enemy's lines by means of a telescope. In the balloon basket he has a telephone which connects with the ground station, and thus he is able to send constant instructions to the artillery, enabling them to hit their objectives, as well as to keep the officers informed of the general situation. But his stationary position makes him an easy target for enemy bombs and bullets. At any moment he may find himself attacked by a squadron of airplanes. At the first indication of danger his comrades on the ground begin hauling his balloon down, and this precaution may possibly save his life. But often the emergency is very great. The aeronaut, attacked, unexpectedly and with no means of defending himself, has but one chance of saving his life, and that is to spring with his parachute from the balloon. Thus the parachute was instrumental in saving many lives during the Great War, and in peace times it will probably be further developed for use in connection with the airplane as well as the balloon. Here the great difficulty lies in the fact that the pilot is strapped in his seat, and that he would not have time, in case of an accident in mid-air, to unstrap himself and attach a parachute device to his body. This might be overcome by having an apparatus already attached, so that all he would have to do would be to free himself from his seat and leap over the side. Here again he would run a very great danger of being instantly killed, as unless he maneuvered his control levers just right before taking the leap, he would probably be hit by his own machine. The idea has been suggested of a parachute arrangement to be attached to the upper wing of the airplane itself. This parachute would remain closed except in case of accident, when a lever operated by the pilot would cause it to open and carry the airplane safely to the ground. But the plan has never been worked out and it is impossible to say at this early date whether it would prove of much real benefit. In cases of engine failure the aviator can very often glide down safely to the earth; while in wartime, there is always the possibility that if the wings of the airplane were damaged by enemy fire the parachute also might be impaired. An interesting use of the parachute was made by bombing airplanes and Zeppelins during the Great War. The pilots of these craft dropped flares or lights attached to parachutes, and by means of these they succeeded in locating their objectives and at the same time in "blinding" the operators of searchlights and anti-aircraft guns. Just what the future of the parachute will be it is hard to predict. If there are to be future wars it will no doubt play an important part in them in the saving of human life. The next few years will probably see the advent of huge aerial liners, built somewhat on the design of the Zeppelin. These great airships will travel in regular routes across the important countries of the world, bearing heavy cargoes of merchandise and large numbers of passengers. And we can easily imagine that in that day every traveler in the air will be supplied with a parachute as the ocean traveler of to-day is provided with a life-belt. Thus the simple little parachute will have performed its useful mission in the triumphal progress of aeronautics. CHAPTER V BALLOONING IN THE GREAT WAR If you went down New York Bay during wartime you probably saw at the entrance of the harbor a United States cruiser stationed, with a "kite" balloon attached to it, standing sentinel against enemy submarines or aircraft. From their positions high in the basket, the observers could see far below the surface of the water, for the higher one rises in the air the clearer the depths of the water become to the vision. They had powerful glasses and by means of them could see far out over the water, where at any moment a periscope might have shown its face. The observers in that sentinel balloon could spot a submarine while it was still a long way off. A telephone connection reaching from the basket to the ship below made it possible for them to report a danger instantly, and soon the news would be traveling by wireless to the waiting destroyers and chasers. This was probably the most important war duty that was being performed by a balloon on this side of the Atlantic. But over in Europe the kite balloon did valiant service above the trenches. The coming of the heavier-than-air machine, with its powerful motor, its bird-like body, its great speed and lifting power, seemed at first to have driven the balloon from the field as an implement of war. And in fact, in the early days of the World War the airplane was almost exclusively employed by the Allies for scouting over the lines, watching enemy movements, directing artillery fire, and keeping the general staff informed of the strategic situation. It was the Hun who first discovered that many of these duties could be far more efficiently performed by the "kite" or "sausage" balloon--the drachen balloon, as the Germans called it. This was not originally a German invention. It was first proposed in 1845 by an Englishman named Archibald Douglas, but his experiments did not meet with success and the undertaking was allowed to drop. Two Prussian officers, Major von Parseval and Captain von Sigsfeld, seizing upon the idea of the kite balloon as of great military importance, set themselves to developing it. In 1894 they produced the first drachen balloon, and it was this that gave the German army at the outbreak of the war one of its greatest advantages over the Allies. The chief requirement for any observation balloon is that it shall rest in the air absolutely steady and motionless, so that the observer may not be interrupted in his study of the enemy's territory. The spherical balloon is apt to sway and roll with every puff of wind. The "kite" balloon therefore is a great improvement. Long and sausage-shaped, it combines the features of a kite and a balloon. Set at an angle to the wind, it is supported partly by the gas with which the main envelope is inflated, and partly by the action of the breeze blowing against its under surface, exactly as a kite is held in the air. A smaller balloon, or steering ballonet, as it is called, is attached to the stern of the kite balloon and acts as a rudder. This ballonet is not inflated with the gas. It hangs limp while the balloon ascends, but the breeze quickly rushes into its open end beneath the main envelope and fills it out. This air-rudder, as it catches the breeze, acts as a steadier for the balloon. The main envelope has also an air chamber or section at the rear, which is partitioned off, and which is not filled with gas but is kept inflated by the action of the breeze; while on either side of the rudder there are two small rectangular sails, which help resist any motion of the breeze which might cause the balloon to sway. Before the war the other large powers had made no attempts to imitate the German "drachen," although they had every opportunity of observing and studying it, and it seems very likely they actually underestimated its military importance. But when the war began, Germany surprised the Allies by the efficiency of these observation posts in the air. The fact that they were captive gave them certain advantages over the airplane for particular lines of work. They were able to direct artillery fire and keep the general staff informed of the situation over the lines. High in the air these lookouts could spot the tiniest change in the map. Provided with the finest instruments for observing, and connected with the artillery station or the headquarters by telephone, they could send in momently reports of the progress of the battle. While the airplane was circling the sky to watch the effects of the last artillery fire, and had to get back to the ground before it could give full instructions to the gunners, the man in the basket of the kite balloon with a telephone in his hand, could report every second just where the last shell struck, whether the shooting was too high or too low, and how to vary the aim to get closer to the target. He was the eye of his battery. The story of how the French military authorities at Chalais Meudon succeeded in obtaining plans for the first French military kite balloon was one of the carefully guarded secrets of the war. In the spring of 1915 the manufacture of kite balloons was well under way in France. In record time whole battalions of them were ready for service on land and on sea. They played a gallant rôle in the Dardanelles in connection with the British fleet. Soon afterward they were employed over the trenches in France. The military kite balloon's first and chief aim is the directing of artillery fire. This it can do better than the airplane, which travels at high speed and must constantly circle or fly backward and forward in order to keep close to and be able to watch the target that is being aimed at. But the observer in the balloon basket sits practically motionless, while with the aid of a powerful telescope he watches the results of the firing. Before him he has a map on which he can plot the location of the target, and through a telephone connection he can advise the men in the ground station how to vary the range. Think how much easier it is for him to explain to the men below by word of mouth the results of his observations, than for the observer in an airplane, soaring through the sky, to send that same message in a few brief words by means of wireless. As a matter of fact the kite balloon at the front usually carries two observers in its basket: one to work directly with the artillery and the other to do general look-out work. The first has his eye on the target which the men below are trying to hit, and watches for the explosions of shells fired by his battery. But his comrade lets his gaze roam all over the horizon. He sees the movements of enemy troop trains, the massing of men and supplies, the flashes of the enemy's batteries. Should some objective of great importance loom up in the distance, such as a convoy of ammunition, the word is passed instantly to the battery below, and the guns are trained on it. [Illustration: INFLATING A SERVICE BALLOON ON THE FIELD] After the work in connection with the batteries, the second great rôle of the observation balloon is to keep the commanding officer at headquarters informed of the movements of the enemy, the effects of the firing and the general situation. The men in a balloon of this sort must know the territory very intimately, so that they can spot the tiniest change. It is their duty to discover concealed batteries and other objects behind the enemy's lines which may help the Divisional staff to lay its plans. And remember that they have no landmarks to go by. Out in that dread region of battle not a tree nor a mound has been left to vary the dull monotony of the brown earth, swept clean by the constant rain of shells. So it requires sharp eyes to distinguish the carefully camouflaged batteries of the enemy. [Illustration: ARMY BALLOON READY TO ASCEND] Of course the observation balloon at the front has to be carefully protected, for it furnishes a good target for the bombs from enemy aircraft. Every kite balloon has its detachment of defending airplanes, which circle round it in wide circles, on the lookout for approaching bombing planes of the enemy. Anti-aircraft guns also stand guard against the danger. Nevertheless the observer's life is a perilous one, the more so because he is a fixed target, unable to shift his position. A story is told of the heroism of Emile Dubonnet, the wealthy French sportsman, who was observing for the French "75's" near Berry-au-Bac when he was attacked by two German taubes. Appearing suddenly out of the clouds, they swooped down upon him, hovering over his balloon and dropping shells, which fortunately missed their aim. The taubes were so near to the balloon that the French were forced to stop firing lest they hit their own man. Coolly Dubonnet continued his observations of the enemy's territory, telephoning the results of their fire to the French batteries below him, until a couple of French planes arrived on the scene and drove the taubes back to their lines. So severe is the strain of constant scanning of the enemy's territory through high powered glasses that it was found necessary to draw the observation balloon down about every two hours in order to change observers. At dawn the first balloons were sent up. All day long, except for the brief intervals when observers were changed, they stood there in the sky. Often far into the night they continued to play their silent rôle in the great drama of war. Some of the observers in fact became so experienced that they were able to do almost as good work at night as by day. It is said that enemy guns so camouflaged that they are not visible by day not infrequently show up in the darkness. The kite balloon is connected with the earth by means of a strong steel cable, which winds onto an immense reel. To send the balloon up, the reel is turned and the cable is played out; when it is necessary to draw the balloon to earth once more, the cable is again wound about the reel. An electric motor is attached to the reel and turns it in one direction or the other. Through the center of the cable runs the telephone wire which connects the observer in the basket with the battery with which he works. The observer is equipped with a parachute for use in case of sudden danger. This parachute has straps like those of a man's suspenders which hold it to his back. When he springs from the balloon the parachute quickly opens and lands him gently and safely on the ground. The kite balloon itself has been greatly improved since it was first constructed by the Germans. One of its greatest disadvantages lay in the great drag upon the cable, which when the wind was very high caused such an excessive strain that it was dangerous to use the balloon. The German "drachen" was badly "streamlined," that is to say, its shape offered great resistance to the wind. This resistance was increased by the rush of air into the open mouth of the steering ballonet. An attempt to improve the design of the kite balloon was made by an American firm, the Goodyear Tire and Rubber Company of Akron, Ohio. They constructed a balloon which in general outline resembled the German "drachen," but which had not the steering ballonet or rudder at the stern. In its place they substituted large flat fins at the stern, and these, while they offered less resistance and thus reduced the strain or tug of the balloon upon its cable, did not hold the balloon absolutely steady in the air, as the steering ballonet had done. In order to give great steadiness the Goodyear people designed a tail like that of a kite, consisting of a number of very small inverted parachutes. These as they caught the breeze produced a resistance which steadied the balloon after the manner of the air rudder. The Goodyear kite balloon was not an unqualified success, and it remained for Captain Cacquot of the French army to produce the most satisfactory design. His was an almost perfect streamline model. Long and sausage-shaped like the German "drachen," it has, in place of the steering ballonet, three small ballonets at the stern which are in reality inflated fins. They are filled with air which is fed to them by a mouth or opening underneath the main envelope. These inflated fins, while acting as a rudder to hold the balloon steady in the air, do not offer the resistance that was caused by either the flat fins of the Goodyear model or the open-mouthed steering ballonet of the old type. Thus the French streamline balloon came to be the accepted model of the Allied nations, and proved itself an efficient arm of the service during the war. Ballooning in itself will probably never be the sport that it once was, for the coming of the swift motor-driven dirigible and the still swifter airplane has made the old wind-driven vessel a hopelessly obsolete contrivance. It is therefore all the more interesting to know that the captive balloon, developed to highest form of efficiency, gave good service in the war against Germany and made itself a reliable and valuable servant of our armies, accomplishing its mission in a particular field in which neither the airship nor the airplane was able to compete with it successfully. PART II CHAPTER I DEVELOPMENT OF THE DIRIGIBLE No sooner had the Montgolfiers and their colleagues constructed their earliest balloon models than scientific men and the general public, aroused by the possibilities of navigating the heavens, set themselves to devising schemes for steering aircraft. For of course the one great faculty which the balloon lacked was the ability to choose its own course. Once it arose into the air it was carried along in the direction and at the speed of whatever wind happened to be blowing. Interest in the problem waxed so hot that there was scarcely a banker, farmer or grocer of those early days who did not have his private theory concerning the steering of balloons. Many learned essays on the subject were written, and many foolish solutions were advanced, among them that of harnessing a flock of birds to the balloon, with reins for guiding them. But the idea every one thought most likely was that of oars, sails and a rudder. Now there are several very good reasons why this method, adapted from sailing vessels, is useless when it comes to a balloon. In the first place, no sooner has the balloon risen to its maximum height into the atmosphere than it is caught in an air-current and carried along at exactly the same rate of speed as that at which the air itself is moving. To the occupants it seems to be hanging motionless in a dead calm, where there is no breeze blowing. Since its motion and that of the surrounding air are exactly equal, there is of course no resisting pressure against a sail, which simply hangs dead and lifeless. To "row" in the air, on the other hand, would require oars of enormous size or else moving at a tremendous speed and a superhuman strength would be needed for moving them. Stop to think of the great velocity and power of the wind and then try to imagine the strength that would be necessary to row against this tide. These facts, however, did not occur to the early experimenters, and balloons equipped with sails and oars were actually constructed. In order that they might present less resistance to the air, they were made egg-shaped, or long and cylindrical, sometimes with pointed ends, and this, at least, was an advance. Another step in the right direction was the suggestion of paddle wheels, projecting from each side of the car, and beating the air as they revolved. This was coming very close to the correct solution, that of a revolving propeller. But unfortunately at this early date the mechanical sciences were in their infancy, and although soon afterward the idea of a screw propeller did come up, the inventors were handicapped by the fact they knew of no other power than "hand-power" with which to drive it. The man who might almost be called the father of the modern dirigible balloon was the French General Meusnier, an officer in the army and a man of great scientific and technical skill. Meusnier just proposed that air-bags or ballonets as they are now called be placed inside the balloon proper. By pumping air into these the balloon envelope could be filled out again when it had become partly deflated by loss of gas, for one of the great problems was to maintain the _shape_ of the balloon after a quantity of gas had escaped. This was a good idea, but unfortunately its first public trial almost resulted in a tragedy. One Duke de Chartres ordered a balloon of this sort to be built for him by the brothers Robert, Parisian mechanics. Accompanied by the Roberts themselves and another man he ascended in it in July, 1784. The balloon was fish-shaped and was equipped with oars and a rudder. No sooner had it started on its upward journey than it was caught in a violent swirl of air which tore away the oars. The opening in the neck of the balloon became closed over by the air bag inside, and there was no outlet for the gas, which expanded as the balloon rose. Undoubtedly a terrific explosion would have occurred, but the Duke, with great presence of mind, drew his sword and cut a slash ten feet long in the balloon envelope. He saved his own life and that of his comrades. The gas, escaping through the rent, allowed the balloon to settle slowly to earth, without injury to its occupants. But the spectators did not understand the emergency, and the Duke was covered with ridicule for his supposed cowardice. The idea of the air-bags, however, was a useful one, and in later experiments worked well. Meusnier gave a great deal of earnest study and experiment to the dirigible balloon, and he originated a design which was far ahead of his day. He decided on an elliptical or "egg" shape for the envelope, with small air bags inside it, and he suggested using a boat shaped car, which would offer less resistance to the air than the old round basket. The car was attached to the balloon by an absolutely rigid connection, so that it could not swing backward as the balloon drove ahead. Halfway between the car and the envelope he placed three propellers, and these, for want of any form of motor, were driven by hand pulleys. Meusnier's design for a dirigible was the cleverest and most practical of its day, but owing to the cost, it was never actually carried out. In 1793, General Meusnier was killed at Mayence, fighting against the Prussians. After his death, little was heard of the dirigible balloon for another fifty years. Except perhaps for the novelty balloons at the country fair, the science of aeronautics slept. The next appearance of the dirigible in history was in 1852, when the work of the Frenchman Giffard attracted widespread attention. In 1851, Giffard had constructed a small steam engine, of about three horsepower, and weighing only 100 pounds. He thought it could be used for driving a balloon, and with the aid of a couple of friends he set to work building an airship, which was somewhat the shape of a cigar, pointed at the ends. It was 144 feet long and 40 feet in diameter at its thickest part, and it held 88,000 cubic feet of gas. Over the envelope was spread a net from which a heavy pole was suspended by ropes. At the end of this pole, or keel, as Giffard called it, was a triangular sail which acted as a rudder. Twenty feet below the pole hung the car, in which was the steam motor and propeller. With this new means of driving the propeller, the dirigible began to show signs of proving a success, although as yet it could not develop any very great speed. One reason was that the engine was too heavy in proportion to the power it generated. Giffard's airship under the most favorable conditions could only go at from four to five miles an hour, when there was no wind. One of the problems Giffard had to solve was that of preventing an explosion of the gas escaping through the neck of the balloon, as it came in contact with the heat of the engine. To avoid this, he placed a piece of wire gauze, similar to that used in safety lanterns, in front of the stokehole and the smoke of the furnace was allowed to escape through a chimney at one corner of the car, pointing downwards. Giffard's second airship, of somewhat different design, was destroyed by an accident on its very first trip. He at once began working on a design for a giant airship, which was to be 1,970 feet long, and 98 feet in diameter at the middle. The motor was to weigh 30 tons, and he estimated that the airship would fly at 40 miles an hour. He worked out the scheme in every detail, but owing to the expense the dirigible was never made. The first "military dirigible" ever built was that constructed by Dupuy de Lôme for the French government during the siege of Paris, and tried out in 1872. Its propeller was driven by a crew of eight men, a very curious proceeding, since the steam engine had been successfully tried. A dirigible which was almost modern in design was meanwhile being constructed by Paul Haenlein in Germany, and made its appearance in 1872. It was long and cylindrical, with pointed ends, the car placed close to the balloon envelope, to give a very rigid connection. Its really noteworthy feature was the gas engine, replacing the steam engine that Giffard had used as a means of driving the propeller. The gas for the engine was taken from the balloon itself and the loss was made good by pumping air into the air-bags. The balloon envelope held 85,000 cubic feet of gas, and of this the engine consumed 250 cubic feet an hour. This dirigible, on trial trips, attained a very fair speed, which would have been greater had hydrogen gas been used in the envelope instead of ordinary gas. But lack of funds prevented further experiment, and Haenlein had to abandon his attempts. Ten years now passed before the next notable effort at dirigible construction. The delay was probably due to the fact that no suitable driving power was yet known. In 1882 the famous French aeronauts Gaston and Albert Tissandier constructed an airship somewhat similar to Giffard's models, but containing an electric motor. But although this dirigible cost £2,000 or almost $10,000 to build, it had the same fault as all that preceded it; it could not develop speed. The problem of finding an engine of sufficiently light weight and high power was a difficult one, which has not to-day been wholly solved. The public generally had begun to think of the dirigible balloon as impractical and impossible, when in 1884 came the startling news that two French officers, named Renard and Krebs, had performed some remarkable feats in a balloon of their own design. An electric motor of 8-1/2 horsepower drove the propeller. Several details of this dirigible are extremely interesting. The axis on which the propeller blades were fixed could be lifted in order to prevent them from being injured in case of a sudden drop. A trail rope was also used so as to break the shock which might result from a sudden fall. At the back between the car and the balloon was fixed the rudder, of unusual design, consisting of two four-sided pyramids with their bases placed together. Renard and Krebs christened their dirigible "La France," and on August 9, 1884, they gave it its first public tryout near Chalais, with great success. They traveled some distance against the wind, turned and came back covering a distance of about 5 miles in 23 minutes. Never before had a balloon been able to make a trip and return to the place of its ascension. But in spite of the success of Renard and his comrade, construction of dirigibles in France paused for sometime, and it was in Germany that the next attempts were made. In 1880, a cigar-shaped dirigible, equipped with a benzine motor was demonstrated in Leipsic. It had been built the year before by Baumgarten and Wölfert. At its sides it had "wings" or sails and three cars were suspended from it instead of one. This airship met with a serious accident on its very first trip. A passenger in one of the cars destroyed the balance, the whole thing toppled over and crashed to the earth, the occupants miraculously escaping injury. Not long afterward Baumgarten died. Wölfert constructed a new dirigible of his own design containing a benzine motor in which he ascended from the Tempelhofer Feld, near Berlin, in June, 1897. Wölfert had neglected to provide against contact of the gas escaping from the envelope with the heated fumes from the engine. An explosion took place in mid-air, and the machine fell to earth in a mass of flames, killing Wölfert and the other occupant. [Illustration: GIFFARD'S AIRSHIP] Next in the long series of attempts came that of an Austrian named David Schwartz, who designed a dirigible with one entirely new feature: a rigid aluminum envelope. This balloon had a petrol engine. It was tried out in Berlin in 1897, but an accident to the propellers brought it crashing to the ground. Its occupant jumped for his life and barely escaped killing. Up to this time there is little to record in dirigible history but a long series of valiant attempts and failures, punctuated all too frequently by grewsome disasters. But the nineteenth century was drawing to a close, the twentieth century with its era of mechanical triumphs was at hand, and the time was ripe for those champions of the dirigible to appear who should make it a potent factor in modern warfare. [Illustration: SANTOS-DUMONT ROUNDING THE EIFFEL TOWER] Almost at the same time there stepped into the limelight of public interest two men, representing Germany and France, whose names are now famous in the aeronautic world. In 1898 there appeared in Paris a young Brazilian named Santos-Dumont, who began constructing a series of dirigibles whose success astounded the authorities. In exactly the same year Count von Zeppelin, in Germany, formed a limited liability company for the purpose of raising funds for airship construction. His first dirigible balloon was the longest and biggest that had ever been built. Although the envelope was not, like Schwartz's dirigible, of solid aluminum, it was practically rigid, for it was made by stretching a linen and silk covering over an aluminum framework. Zeppelin's first airship had two cars, with a motor in each, giving about 30 horsepower. On its trial trips it made a better speed than had yet been attained. With the experience he had gained Zeppelin set to work on a new design. It was five years before he secured enough funds for its construction, but it was finally ready in 1905. The most important improvement was in the motors, which were as light in weight as those of the first dirigible but had a greatly increased power. As before, there were two cars, with an 80 horsepower motor in each. Even this airship, in spite of its greater speed, was not an unqualified success, for it was discovered that it had too great a lifting power, so that when launched it rose at once to a height of about 1500 feet, and was impossible to operate at a lower level. Santos-Dumont, meanwhile, in Paris, had been performing feats of aeronautics which had made him the acknowledged "hero of the air." Santos-Dumont was probably far from being the scientific student of balloon construction that Zeppelin was, but while his dirigibles did not attain a great speed or represent a tremendous advance in actual theory, his public performances served one great purpose, they aroused the ardor and enthusiasm of the whole French people and of many in other countries for the sport of ballooning. Santos-Dumont had great wealth, and a sportsman's courage. He constructed in all 14 dirigibles, each time seizing upon the experience he had gained and incorporating it into a new model, casting aside the old. Santos-Dumont's airships were altogether different from those of Zeppelin. While Zeppelin's had an inner framework to maintain the shape of the envelope, Santos-Dumont depended entirely on the linen air bags, placed inside the balloon, which as it became flabby through loss of gas, could be pumped full of air to hold the envelope in place. His balloons were either long and cylindrical with pointed ends, "cigar-shaped," or else "egg-shaped," with ends rounded. In spite of all the curious accidents that beset this young Brazilian on his early trips, in the vicinity of Paris, he was never once deterred from his efforts. He almost lost his life several times in his first airship, but he profited by the mistakes of construction in building the second. His dirigibles increased in size as he installed in each successive model a more powerful and consequently heavier motor, requiring greater lifting power. In his third balloon Santos-Dumont ascended from the Champ de Mars in Paris and circled the Eiffel Tower amid the cheers of thousands of onlookers, finally descending in an open field outside Paris. Public interest was now thoroughly aroused. A prize of £4,000 was offered by Monsieur Deutsch to the aeronaut who could circle the Eiffel Tower and return to the starting-point at Saint Cloud within half an hour. Santos-Dumont attempted this with his 4th and 5th machines, but it was not until he built his 6th model that he finally accomplished it. The Brazilian government sent him a gold medal and an additional £5,000 with which to build new balloons. Number 9 was the most popular of all Santos-Dumont's machines. He became the idol of the French public, whom he was always surprising with his spectacular and unlooked-for adventures. During the races at Longchamps he descended on the race course, stayed to view the performance, then mounted in his car and rode away. He amazed the passersby by alighting before his own front door in Paris where he left his airship while he went and ate breakfast. He sailed up opposite the grandstand when President Loubet was reviewing the French troops, fired a salute, and as unexpectedly departed. Santos-Dumont's power of escape from death seems almost uncanny but it was due to his coolness in facing any situation. In the majority of his airships he used a petroleum motor, and with this there is considerable danger of the petroleum in the reservoir catching fire. On one occasion a fire did start, but he succeeded in extinguishing it with his panama hat. Among all his mishaps, including that of falling into the Mediterranean Sea, he never really had a serious explosion. Another young Brazilian, however, named Severo, was killed in a dirigible of his own construction, when the petroleum in the engine caught fire. He ascended in May, 1902, in a balloon which he called the _Pax_. His car was seen suddenly to burst in flames, a violent explosion followed, and the whole thing crashed to earth. Santos-Dumont placed his last three dirigibles at the disposal of the French military authorities. Actually he had not developed a type suitable for military use. But his public performances had aroused intense popular interest and had succeeded in opening the eyes of the French authorities to the possibilities of the airship in time of war. His remarkable aerial feats had attracted the attention in particular of two Frenchmen of his own fine metal and courage, who from this time forth left no stone unturned to excel him in his achievements. CHAPTER II FORERUNNERS OF THE ALLIED DIRIGIBLES It is to the two French brothers Lebaudy that France and the Allies owe the credit for the development of the big military dirigible such as is used in the present War. These brothers were wealthy and full of enthusiasm for aeronautics. From a distance they had watched the achievements of Santos-Dumont and they determined to expend every possible effort to excel him in the construction of dirigibles. In 1899 they commissioned an experienced engineer named Jouillot to make a study of the problem, to discover if possible why previous experimenters had failed to produce a model of satisfactory speed and power, and to draw up designs for an airship which should correct the faults of those already known. It took two years before a finger could be lifted toward the actual building, but finally in 1901 the work of constructing the first Lebaudy airship commenced. It was ready for a tryout in November, 1902. The envelope was of bright yellow calico: it was cigar-shaped, 187 feet long and 32 feet in diameter. The envelope was fastened at the bottom to a rigid floor-work of steel tubing and from this the car was suspended. The dirigible was fitted with a 40 horse power benzine motor; and its total weight, including a supply of benzine, water and ballast, was two and one-half tons. During the next year this dirigible made at least 30 trips, at very fair speed. Meanwhile the builders were studying it in every detail, working out ideas for improvements and drawing up plans for their next model. In 1904 they built their second airship. It was somewhat longer than the first and about the same shape, but the pointed end at the rear had been rounded off. Calico was again used for the covering of the envelope, and it was made absolutely air-tight by coating it inside and out with rubber. Besides the main valve there were safety valves in the envelope for allowing the gas to escape when the pressure became too great. The envelope was also provided with two small windows, so that the inside of the balloon could be easily inspected. It had sails to give it greater stability, and two movable sail-like rudders, placed together at a V-shaped angle. The driver could alter the position of the sails and the rudder according to the wind. The car of this Lebaudy airship was boat-shaped with a flat bottom. To diminish the shock in case of a fall steel tubing was placed in a slanting position beneath it in a pyramid arrangement, the point facing downwards. The car was set very close to the envelope or body of the airship, and carried the 40 horse power benzine engine. At the front of the car was an electrically worked camera, a 1,000,000 candle power acetylene projector providing lighting by night. Many improvements were later added to this second dirigible which was christened the _Lebaudy_. The interest of the French Minister of War was aroused and he appointed a commission from the Balloon Corps to follow the progress of the experiments. Every one now began to look upon the dirigible as a factor to be reckoned with in the event of a war. The Lebaudy brothers offered their airship to the French government, and after it had accomplished a series of tests to prove its value as an instrument of war, it was accepted, and became a model for later airship construction. Germany was not far behind, for already Count von Zeppelin's second airship had proved itself a success, and plans were being laid for a third. From this time on the two European nations destined to become powerful adversaries in the World War, though working along somewhat different lines, kept almost neck and neck in their struggle for air supremacy. The French military balloon department began at once the work of constructing an airfleet with the _Lebaudy_ as a model and with the engineer Jouillot as chief adviser, this work went forward with great rapidity. The _Lebaudy_ was followed in design pretty closely, but a few changes were made which experience had suggested. For one thing the balloon envelope was rounded at the front and pointed at the rear, exactly the reverse of the Lebaudy model, as this arrangement was thought to offer less resistance to the air. It had an internal air-bag or ballonet whose capacity was one-fifth that of the envelope. This ballonet was of course empty on the ascent. It was calculated that the balloon could reach a height of about a mile. To descend, gas would then be allowed to escape, and, in order to keep the envelope fully inflated, air would be pumped into the ballonet. This first type of dirigible actually constructed by the French army was called the _Patrie_. It was 197 feet long and carried a benzine motor of from 30 to 40 horse power, which drove the two double-bladed steel propellers. As in the case of the _Lebaudy_, the _Patrie_ was protected from injury by a strong steel framework, coming to a point below the car. In case of a sudden drop, this point would strike the ground first and ward off the blow from the car, and the propellers. Good as this plan _seemed_, it did not always work. The _Patrie_, after many successful journeys, met with an accident to her motor, escaped her guard of soldiers and drifted off alone. She crossed the English Channel and fell in Ireland, breaking off her propeller. Before she could be captured she rose again into the air, drifted out over the sea and was never again heard from. M. Deutsch, who had done so much to encourage the efforts of Santos-Dumont, stepped forward in the emergency and offered the French government his airship the _Ville de Paris_. This had been designed for him by an engineer named Tatin. It was 200 feet long, made of German Continental Rubber Fabric, and, like the _Patrie_, had an internal air-bag of one-fifth its capacity. In one important respect it was different from those that preceded it. At its stern it had eight small cylinders, or ballonets, filled with gas, which added greatly to its stability, though they detracted from its speed by causing a considerable resistance to the air. While the car of the _Patrie_ was about 16 feet long, this new airship had a car measuring 115 feet, and the propeller was at the _front_, so that as it revolved it _drew_ rather than _pushed_ the car through the air. A propeller of this sort is termed a "tractor," and figures to-day in many models of aircraft. During these years of experiment in France, England and America had looked on in comparative idleness. In 1902 England did indeed possess one small airship, designed by Colonel Templer of the Army Balloon Department, and christened the _Nulli Secundus_ (_Second to None_). She was "sausage shaped:" rounded at the front and pointed at the stern with a peculiar rudder design. Her car was boat-shaped and her propellers were aluminum, both revolving in the same direction, which gave her a curious tendency to "somersault." In spite of their "baby" dirigible's rather pretentious title, the military authorities, and the English public in general, evidently took slight store in the infant prodigy, for from 1902 to 1908, she only came out of her shed for a few short trips. In 1908 she was completely remodelled, and emerged for a trial trip. But neither the government nor the public seemed interested in Colonel Templer's schemes. The valiant little pioneer ship of England's airfleet went back to her sheds, resigning herself to obscurity. Our own country, which in many other lines has led the world in its mechanical skill and enterprise, did not have a single army dirigible till as late as 1908, when it gave out a contract for an airship which was built by Captain Thomas S. Baldwin. The motor was designed and built by a young mechanic in Hammondsport, N. Y., who for several years had been manufacturing motors for automobiles. His name was Glenn Curtiss and he afterward became one of the world's most famous aviators. United States Army Dirigible No. 1 was long and cylindrical, pointed at both ends, and covered with Japanese silk, vulcanized with rubber. The water-cooled Curtiss motor was a 20 horse power, and the wooden propeller was of the "tractor" type, placed in the front of the car. Germany, while America and England stood idle, had been rapidly forging ahead. By 1908 Count von Zeppelin had constructed his third and fourth models, and his public demonstrations had aroused the whole German people to unbounded enthusiasm. The Crown Prince made a trip in Zeppelin No. 3 and its originator was decorated with the Order of the Black Eagle. The German Association for an Aerial Fleet was formed, and within a short time over a million dollars had been contributed by the people for the purpose of building dirigibles. Zeppelin No. 4 was destroyed by an accident, but Zeppelin No. 3 was recalled into the national service and in 1909 given the official title of _S.M.S. Zeppelin I_. From this time on dirigible construction in Germany went forward with the greatest speed. Two other names became prominent in the enterprise: those of Major von Parseval and Major von Gross. The "Parseval" design resembled more the French, for it was covered with "Continental fabric," was long and cylindrical, rounded at the front and pointed at the stern, with a large internal air ballonet. The car was suspended from two steel cables or trolleys, which it could slide along, altering its position and the "balance" of the whole airship. The "Gross" type of airship resembled the _Lebaudy_ and the _Patrie_, with its boat-shaped car hung from a steel platform attached to the bottom of the envelope. Out of this brief story of the development of the early airship models of all the nations, we can, if we look carefully, see certain definite types of dirigibles emerging. The experimenters had to solve this problem: What shall we do when owing to loss of gas the balloon envelope begins to get flabby? For of course a flabby, partially filled envelope would flop from side to side, destroying the balance of the airship and checking its speed. [Illustration: BALDWIN U. S. "DIRIGIBLE NO. 1"] The German inventors settled the problem by making the envelope _rigid_, either with a solid covering or with a covering of fabric stretched over an inner framework. Thus the _rigid type_ of airship was evolved. The French inventors solved the same problem by placing inside the envelope a large _empty_ bag of fabric, into which air could be pumped when necessary to fill the balloon out and hold the envelope firm. The air could not be pumped directly into the envelope itself as it would produce an explosive mixture with the gas already there. From this method of dealing with difficulty, the _non-rigid_ type of dirigible was evolved. [Illustration: THE BRITISH ARMY "BABY" DIRIGIBLE] But the _non-rigid_ dirigible presented a new difficulty: how could the car be suspended from it in such a way that it would not swing? For only with a rigid connection between the car and the envelope could the greatest speed be obtained. The _Lebaudy_ solved this problem by attaching to the base of the envelope a rigid steel flooring, from which the car could then be suspended by an immovable connection. And so was evolved the _semi-rigid_ type of airship. In recent years another solution of this problem of preventing the car from swinging has been employed to some extent: By making the car almost as long as the envelope, the connecting cables by which the car is suspended hang almost perpendicular, and there is not the same tendency to swerve as with cables slanting down to a comparatively small car. This type of airship is called the _demi-semi-rigid_. These then are the four general classes of dirigibles which were used in the Great War. CHAPTER III DIRIGIBLES IN THE WORLD WAR When in August, 1914, the sinister black cloud of a world war appeared on the horizon, only the Hun was prepared for the life and death struggle in the air. His formidable fleet of super-Zeppelins had not their match in the world, and his program of airship construction was being pushed forward with the utmost speed and efficiency. France had the largest fleet of dirigibles among the Allied nations. They were of the semi-rigid type, of only medium size and slow speed. They could not hope to compete on equal terms with the swift and powerful German airships. Great Britain was far worse off than France, for her airship fleet practically did not exist. The army had only two large modern dirigibles and a few very small vessels like the old _Nulli Secundus_, of little practical value. The navy had no airships at all. Italy had a few good medium sized vessels, and four large dirigibles were in process of building. Russia, too, had several airships purchased from the other countries, of various makes and types, but she lacked experienced aeronauts with which to operate them. Both France and England had already made extensive plans for the building of dirigibles, but few of the ships ordered were near to completion in 1914. Only the Prussian was ready for hostilities; his airships gave him a great strategic advantage. By means of them he gained information about the movements of Allied troops and munitions; directed his artillery, bombed Allied positions, and went his way, for the most part unchallenged. His naval airships were likewise a terrible menace. One of them, in the early part of the war, received an iron cross for its work in connection with a German submarine, in an attack on three British cruisers. Every one knows of Germany's record in the bombing of cities and towns by means of Zeppelins. In the first days of the war the Allies had no anti-aircraft guns and very few airplanes with which to protect themselves, and so Germany went unmolested while she waged her war against defenseless civilians, women and children. The spirit of the Allies, however, could not be daunted. England put her few small dirigibles on duty over the English Channel, where they served as patrols against submarines. For this work airships are very effective, since it is a curious fact that from their height in the atmosphere it is possible to see far below the surface of the water. So during the first tragic weeks, when France and Belgium were pouring out their life-blood to check the onward sweep of the Hun, these tiny aircraft stood guard over the Channel across which the "contemptible little army" of Britain was being hurried on transports to meet the invader. Like the contemptible little army itself they proved a factor to be reckoned with. Such aerial scouts now form a large arm of the British, French and American navies. Soon after the war began they were constructed in large numbers to serve as patrols against submarines. In the language of the air, these little dirigibles are known as _Blimps_. The _Blimp_ was first developed for use in the war by the British Naval Air Service, but the United States soon saw its advantage as a means of patroling and guarding our harbors and coastline, and so she set to work to manufacture this type of dirigible in large numbers. To-day it is the chief dirigible of our aerial fleet. In some important ways it has the advantage over the airplane in combating the submarine. For the airplane can only remain in the air while it keeps going at high speed. Just as soon as its engines are stopped it commences to descend. But the dirigible can sail out over the harbor, shut off its power and remain motionless in the air for hours, while its observer keeps a constant lookout for enemy undersea craft. When speed is necessary its powerful motor makes it a fast flying craft, sometimes considerably faster than the airplane. For the airplane must often travel against the wind, while the dirigible simply rises until it reaches a current of air moving in the desired direction, when it has the combined power of the wind and its engine to drive it forward. [Illustration: CROSS SECTION OF THE GAS-BAG OF THE _ASTRA-TORRES_, SHOWING METHOD OF CAR SUSPENSION] The U. S. A. _Blimp_ is about 160 feet long, rounded in front and tapering to a pointed stern. Its stability and balance are increased by five "fins" at its stern; and it has also four rudders. The car, which is exactly like the ordinary airplane body, has two seats, for pilot and observer, suspended directly from the base of the envelope by wire cables. The _Blimp_ carries a 100 horse power Curtiss aviation motor, and is equipped with wireless for exchanging messages. The French have a small airship very much like the _Blimp_ which they use for scout duty. It is called the _Zodiac_, and before the war was designed as a private pleasure car. Because of the fact that it could be easily packed and transported from place to place it was drafted into the service early in the war. Naturally, if an airship has to be kept inflated when not in use it is a constant target for the enemy's gunfire; and a small dirigible which can be packed up in an hour when not needed and readily inflated when the call for action comes is a very much safer proposition. There are several sizes and slightly different shapes of the _Zodiac_, but the shape of the envelope in all of them is very similar to the _Blimp_, tapering toward the stern with fins to give stability. A large sail-like rudder is set beneath the stern of the ship. Probably the most interesting thing about the _Zodiac_ is the car which in most models has a very long wooden framework. This framework, or girder, by its length distributes the weight along the whole length of the envelope. The car, in which the pilot and observer sit, is set in this girder. [Illustration: _Copyright Underwood and Underwood_ THE "BLIMP," C-1, THE LARGEST DIRIGIBLE OF THE AMERICAN NAVY] Nothing is more interesting to note in modern airships than the simplification of the method of car suspension. In the early airships the car was hung from the envelope by a large number of cables, which either connected with a network that fitted over the envelope, or else, in a semi-rigid dirigible, to the platform or keel at the base of the balloon. Now of course all these cables offered a great resistance to the air and were an enemy to speed. Just as the question of speed affected the shape of the envelope, until to-day we have the streamline balloon, tapering to the rear, and just as it made the question of a rigid or non-rigid envelope so important, it likewise finally did away with complicated connections between the envelope and the car. [Illustration: _Copyright International Film Service, Inc._ THE BALLOON OF THE U. S. S. OKLAHOMA] From the point of view of car suspension one of the most interesting of the modern French airships is the _Astra-Torres_. This is a dirigible of the non-rigid type. Canvas partitions are stretched across the interior of the envelope in such a manner as to form a triangle, its apex facing downwards. The sides of this triangle are strengthened by cables and from its apex hang the cables which support the car. The air resistance produced by the cables is therefore very slight, since only two lines are exposed. Among the aerial war fleets of the Allied nations, the French offers by far the greatest field for study, since it possesses many different types of dirigibles. The _Astra_ and the _Astra-Torres_ are perhaps the chief representatives of the non-rigid design, and are generally considered the most successful of the French airships. The _Astra_ is the older model, and, like the _Zodiac_, has the long wooden framework or car girder, hung directly to the base of the envelope and distributing to all parts of it the weight of the car. It can be recognized by this and by its stabilizers or small inflated gas bags around the stern of the envelope. The _Astra_ is of medium size, varying in length from 199 to 275 feet. The _Astra-Torres_ is very much longer, those of the 1914 type measuring 457 feet from nose to stern. From the exterior, this airship has a peculiar three-lobed appearance. It tapers very slightly to the stern and is pointed at both ends, but it has not the _Astra's_ inflated stabilizers. Another French airship of non-rigid design is the _Clement-Bayard_. It is similar in design and in size to the _Astra_, but without the inflated stabilizers. Rounded slightly at the nose, the envelope tapers to a sharp-pointed stern. The _Lebaudy_ is the chief example of a French semi-rigid airship. The envelope is long and cylindrical, pointed at the nose and rounded at the stern, where it is fitted with stabilizing "fins." The base of the envelope is fitted to a long keel, which ends at the rear in a rudder and fins. From this keel the car is suspended by strong cables, and beneath the car extends a conical structure of steel tubes, with points falling downward. These serve as a protection in case of a sudden landing. In front of the car and on each side of the keel are planes similar to those of an airplane, which help to give balance to the ship. Among airships of the Allies, the French _Speiss_ furnishes an example of the purely rigid design. Constructed on the plan of the German Zeppelin, its envelope has an inner wooden framework which holds it in place. The _Speiss_ is a large dirigible, measuring about 450 feet. It carries two cars, and in each is a two-hundred horse power motor, giving it great speed. PART III CHAPTER I EARLY EXPERIMENTS WITH HEAVIER-THAN-AIR MACHINES For many centuries before the ascension of the first Montgolfier balloon, which, as we have seen, marked the beginning of aerial flight, men had dreamed of a different method of conquering the skies,--in fact, the very natural one suggested by the flight of birds. To build artificial wings was the ambition of many an old-time scientist. Yet practicable as the idea seemed, its working out was, as a matter of fact, beset with difficulties. The Montgolfier balloon rose in the air because it was _lighter_ than air,--just as a piece of cork rises in water because it weighs less in proportion to its volume than the water. But a man equipped with wings is a fairly heavy object; where is the force that is to lift him and carry him soaring into the sky? Unfortunately the early experimenters in aeronautics were not men who had had the long training in keen observation nor the groundwork of mechanical knowledge which would have fitted them for their task of devising a flying machine. They were dreamers and philosophers, often with very clever ideas about how man might succeed in flying. But the exact science of mechanics was yet unborn, and it was not until the nineteenth century, with its great advance in this direction, dawned, that the time was ripe for any measure of success. Still, in many old pictures and medieval manuscripts there are curious examples of the ideas of these old philosophers, designs which were never actually tried out, but which show the longing of men, even in those days, for the great adventure of sailing above the clouds. All these strange theories of the middle ages were hampered by the superstition that there was some "magic" connected with the power of birds to fly. Cameras were unheard of, or it would have been a simple matter to have recorded on paper the actual motions of the bird's wings in order to study their significance. The astounding ease with which these little winged creatures were able to float across the heavens was indeed baffling; it was difficult to determine just how it was accomplished. Any one who watches the flight of a seagull realizes that here is an accomplished aeronaut, able to balance himself with perfect ease in the atmosphere, to mount upward on flapping wings, or, taking advantage of a rising air current which can support him, to float motionless with wings extended. All this requires an unusual amount of skill, particularly in balancing. Drop a piece of paper and watch how it turns and tumbles at every angle before it reaches the floor. That is just what a bird or an airplane has a tendency to do, and it takes a perfect system of control and a skilled pilot indeed, to keep it right side up. The first idea, of course, for a heavier-than-air machine, was that of a pair of wings to be _attached directly to the human body_, and to be worked with the arms. As early as 1480 Leonardi da Vinci drew up a design for an apparatus of this sort. And the idea was not a bad one: it would have worked all very well had it not been for one small fact which the philosophers overlooked, that man is not provided with the powerful shoulder muscles such as the bird possesses for moving his wings. Altogether, it was not until the nineteenth century that any real progress toward flight in a heavier-than-air machine was made. It came when experimenters began to investigate the definite laws of air resistance and air pressure which control the action of a bird just as they do the action of a kite. As a matter of fact, a bird, or an airplane, is nothing more than a complicated kite, controlled by an intelligence within itself, rather than by an operator standing on the ground and guiding it by means of a cord. [Illustration: Kite] Every one knows that a kite, if placed at an angle to the wind, will be carried upward. The reason for this can be seen from a very simple diagram. The pressure of the wind would, if unhindered, push the kite into a horizontal position. But the string prevents the angle of the kite from altering, and since the pressure on its lower surface is greater than that on its upper, it naturally rises. This is just what happens when the bird sets his wings at such an angle to the wind that he is lifted into the sky. It is also the principle which governs the airplane or glider, whose planes are kept at a definite angle to the air current. The bird can of course readjust the angle of his wings when he has risen high enough, or when he meets a current of air moving in a different direction, and in the same way the elevating plane of a modern airplane can be lifted or deflected at the will of the flyer, to produce an upward or a downward motion. The first man to study seriously the effects of air pressure on plane surfaces was an Englishman named Sir George Cayley, who in 1810 drew up plans for a flying machine somewhat resembling the modern monoplane. In 1866 Wenham patented a machine which involved an ingenious idea, that of several parallel planes ranged above each other, instead of the single surface, as of the bird's wing. Wenham believed that the upward pressure of the wind, acting on all these surfaces would give a far greater lifting power, as well as a greatly increased stability, for the machine could not be so easily overturned. Here was the principle of the modern biplane and triplane in its infancy. Yet the idea of strict "bird-form" was more appealing to the imagination, and the experimenters who came after Wenham did not adopt his suggestions. The man who may truly be said to have given the airplane its first real start in life, was a German named Otto Lilienthal. His figure is a very picturesque one in the long story of the conquest of the air. Lilienthal was a very busy engineer, but from boyhood he had had a consuming interest in the problems of flight, and as he traveled about Germany on his business undertakings he cast about in his mind incessantly for some plan of wings which would support the human body and carry it up into the air. He finally began a very systematic study of the wings of birds with the result that he made some unusual and important discoveries. While the men who had preceded him had attempted only flat wings in their plans for flying machines, Lilienthal decided that the wings should be arched, like those of a bird, heavier in front, with an abrupt downward dip to the front edge, and then sloping away gradually to the rear where their weight was comparatively slight. When still quite a young man he began building kites with planes curved in this manner. To his surprise and joy he found that they rose very rapidly when set to the breeze. They even seemed to move forward slightly in the air, as though they had a tendency to fly. Like a bird resting on a current of air with wings motionless, these little toy wings were carried along gracefully on the breeze. Lilienthal was jubilant. A man equipped with wings like these, he said to himself, would have no difficulty at all in flying. Lilienthal was not a rich man and it was many years before his opportunity to test his ideas with a real flying machine came. When by hard toil at his profession he had accumulated a comfortable fortune, he turned at last to his beloved study. He had often watched the baby birds in their efforts to fly, and he knew it would be a long time before he attained any skill with wings, but he was absolutely confident that with much practise and perseverance he could actually learn to fly like the birds. So he constructed for himself a pair of bird wings, arched exactly like those which he had studied. They were arranged with a circular strip of wood between them for his body. Here he hung, with his arms outstretched on each side, so that he could operate the wings. The difficulties Lilienthal had looked for he experienced in large measure. It was no easy thing to attempt to fly in this crude apparatus, but day after day he went out upon the road, turned to face the breeze as he had seen the baby birds do, ran swiftly a short distance, and then inclined the wings upward so that they might catch the current of air. For a long time he was unsuccessful, but imagine his joy when he actually did one day feel himself lifted off his feet, carried forward a few feet and set down. It was scarcely more than a tiny jump, but Lilienthal knew he had commenced to fly. From that time on his efforts were ceaseless. He succeeded in being lifted a number of feet off the ground and carried for some distance. But try as he would he could not get high in the air. He realized that what he lacked was any form of motive power, and for want of a better, determined to make use of the force of gravity to start him through the air at greater speed. Accordingly he had built for him a hill with a smooth incline, and from the top of this he jumped in his flying machine. The wings he had first constructed he had since improved on, adding two tail planes at the rear which gave greater stability and decreased the tendency to turn over in the air. As he sprang from the hilltop in this curious apparatus, he turned the wings upward slightly to catch the breeze, which supported him exactly as if he had been a kite while he glided out gracefully and finally came gently to earth. This spectacle of a man gliding through the air attracted large crowds. People assembled from far and wide to behold the flying man, and his achievements were greeted with wild cheering. On his huge winged glider he floated calmly over the heads of the astounded multitude, often landing far behind them in the fields. In the difficult matter of balancing himself in mid-air he became exceedingly skilful. Every slight gust of wind had a tendency to overturn him, but Lilienthal constantly shifted the weight of his body in such a manner as to balance himself. As he gained confidence he began practising in stronger winds. His great longing was to soar like a bird up into the sky, and so when he felt a rising air current, he inclined his wings slightly upward to take advantage of it. Often he did rise far above the hilltop from which he had sprung, but he never succeeded in actually flying like a bird. His glider had not the motive power to drive it against the breeze with sufficient velocity to send it up into the air, and his wings were but crude imitations of the wonderful mechanism on which the bird soars into the sky. Undaunted by his failure he set to work on a double set of wings, very similar to a modern biplane. He thought these would have greater lifting power, but when he came to try them he found them exceedingly unwieldy and hard to control. For where the biplane has an intricate control system, Lilienthal relied entirely upon his own body to operate his glider. Lilienthal became more and more reckless in his gliding efforts, and in 1896, while gliding in a strong wind, he lost control of his winged contrivance and came crashing to the earth from a great height. When the horrified spectators rushed to the spot, they found the fearless pioneer flier dead beneath the wreck of his machine. What Lilienthal had done for the cause of aviation, however, would be hard to estimate. He had drawn the attention of thinking people the world over to his experiments. He had pointed the way to the real solution of the problem of flying: that of studying and imitating the birds; and he had discovered the form of plane which on airplanes to-day is well known to give the greatest lifting power: that of an arched surface, deeply curved in front and sloping gradually back to its rear edge where its thickness is very slight. Moreover, his attempts at flight had presented a challenge to engineers and scientists--a challenge which was quickly to bear fruit. An Englishman named Percy S. Pilcher had followed the work of Lilienthal with the deepest interest, and he now determined to begin a series of experiments on his own account. Like Lilienthal he realized that it would be useless to attempt a motor driven airplane until the principles of glider construction were fully understood. A glider is simply an airplane without an engine, and Lilienthal succeeded in giving it a certain motive power by starting from a high point, so that the force of gravity could draw him forward and downward. Pilcher adopted an even more original scheme for making his glider "go." He treated it exactly as if it had been a huge kite, fastening a rope to it and having it pulled swiftly by a team of horses, until it had gained sufficient momentum to carry it up in the air. The moment it began to rise, Pilcher, who hung between the two large wings much as Lilienthal had done, detached himself from the rope and went soaring into the air like a kite, attempting to balance himself and prevent his glider from overturning. But he had not the experience that long and careful practise had given to Lilienthal, and before he had made very many flights in his glider, he fell and met his death. In 1896 an Australian, Hargrave, experimented with kites in order to discover a glider form which possessed both lifting power and stability. He was the originator of the familiar "box-kite," which flies so steadily even in a strong breeze. Hargrave connected four very large kites of this sort by a cable, swung a rope seat beneath them and succeeded in making ascents without fear of accident. Chanute, a Frenchman, now devised a biplane glider with which he succeeded in making brief flights of a few seconds. The way was now paved for the coming of two great pioneers in the history of aviation. Wilbur and Orville Wright were owners of a small bicycle shop in Dayton, Ohio. They were men with an innate mechanical skill and with the same dogged persistence and indifference to physical hardships which might have brought success to Lilienthal if he had had the time to devote to his experiments. The Wright brothers had read with fascination accounts of the gliding efforts of Lilienthal. They determined to set to work to solve the problem of human flight. For two years they read and studied everything that had been written upon the subject, and then finally they felt ready to make a trial of a glider of their own construction. They had made up their minds that Chanute's idea of the biplane was most practicable, and so the machine which they built was not strictly bird form, but had two long planes extending horizontally and parallel to each other, attached by wooden supports. The operator or flier lay face downward in the center of the lower plane. Their glider was too large to be operated with the arms as Lilienthal's had been, and so they had to devise some new method for controlling and balancing it in the air. This they managed by the use of small auxiliary planes, which were operated by levers and ropes. In front of the two large planes was a small horizontal plane which could be raised or lowered. When raised to catch the wind it gave the glider an upward motion which carried it into the air, bringing the large planes to an angle with the wind where they could continue the climbing process. One of the great difficulties of the early gliders was their tendency to turn over sidewise. Lilienthal counteracted this whenever he felt one side of his glider falling by shifting his weight toward the highest wing and thus pulling it down. This crude method was impossible in the Wright biplane. The brothers set themselves to seeking a solution from the balancing methods of birds, and right here they made a discovery which was of the greatest importance to the progress of the airplane. The bird when he feels one of his wings falling below the level of the other, simply droops the rear portion of the wing which is lowest, forming a cup or curve at the back which catches the air as it rushes under. This increased pressure of air forces the wing up again until in a second the bird has regained his balance. Imitating this method, the Wright brothers constructed the planes of their glider in such a manner that a cord fastened to the rear sections of each plane could be pulled to draw the rear edge downward. If the left side of their machine became lower than the right it was a simple matter to pull down the left halves of the rear edges of the two planes, and so catch the air currents which would force that side upward. This ingenious scheme of obtaining sidewise or "lateral" balance is used in a modified form in airplanes to-day, and is known as "wing-warping." The brothers chose the coast of North Carolina as the best place for their first attempts to fly, for there the breezes were usually not too strong. After a good deal of difficulty they learned not only to glide, as Lilienthal had done, but also to soar some distance into the air. They had so far no means of turning around, but this was remedied by fastening at the rear of the two large planes a small vertical plane which could be moved from side to side and which served to turn the glider. There were three achievements in airplane construction which so far could be placed to the credit of the Wrights. One was the _elevating plane_ by means of which an upward or downward motion of the glider was obtained. The second was the ingenious _wing-warping device_, for securing stability. The third was the _rudder_, which enabled the pilot to turn around in mid-air. Not satisfied with what they had already accomplished, the brothers now turned their attention to constructing a motor suitable for use in a flying machine. This had to be exceedingly light and at the same time strong, and some means had to be discovered for converting its power into motion. The first engine they built was a four-cylinder petrol, and it was used to revolve two wooden propellers acting in opposite directions. The blades of these propellers as they churned the air, gave "thrust" to the airplane exactly as the propellers of a ship drive it through the water. In this new model airplane the flier no longer lay face downward as in the old glider, but sat on a bench between the planes, from which he controlled the action of the engine, the elevating plane, the rudder and the wing warping arrangement by means of levers and cords. It was in the memorable year of 1903 that this first real airplane was flown by the Wrights. They continued to work steadily upon the problems of design and construction, and after many trials in the next two years, they succeeded by 1905 in building an airplane which would actually fly a number of miles. They determined to offer their precious secret to some government, and decided on France, which has always been the patron of aviation. But the French government, after an investigation did not accept their offer, and so, disappointed, but still dogged, they retired into silence for a period of several years. In 1908, when their inventions had been patented in every country, they began a series of public demonstrations of their remarkable machine, Orville in America and Wilbur in France. By that time, unfortunately, other pioneers had stepped forward to claim honors in the field which they first had explored, but the Wright biplane easily outstripped its contemporaries. Their wonderful demonstration flights made them heroes, acclaimed by millions, and their achievements aroused immediate and intense interest in aeronautics. CHAPTER II FIRST PRINCIPLES OF AN AIRPLANE It is almost humorous that man, who for centuries had nourished the secret ambition of acquiring wings, should have found his dream imperfectly realized in the twentieth century by riding in a kite. For that is all an airplane actually is. Yet a "kite" which is no longer tied to earth by a cord and which is equipped with a motor to drive it forward at a great speed has one decided advantage over the old-fashioned sort. The paper kite had to wait for a favorable breeze to catch it up and bear it aloft. We saw in the last chapter how the push of the air against the underneath side of the kite caused it to rise. If instead of the air current pushing against the kite, the kite had pushed against the air, exactly the same result would have been attained. A bird, flying in a dead calm, creates an upward pressure of air by his motion which is sufficient to support his weight. But the bird, as he flies forward against the air creates more resistance under the front portion of his body than under the rear, and this increased upward pressure would be sufficient to turn him over backward if his weight were not distributed more toward the front of his body, in order to counterbalance it. This fact can be easily illustrated with a piece of cardboard. Take a small oblong sheet of cardboard and mark a dot at its center. If the cardboard is of even thickness this dot will be the _center of its weight_. Now hold the cardboard very carefully in a horizontal position and allow it to drop. It should fall without turning over, for it is pressing down evenly on the air at all points. You might say it is creating an upward air pressure beneath it, which is evenly distributed. The _center_ of the supporting air pressure exactly coincides with the center of weight. If you have not held the cardboard in a precisely horizontal position this will not be true. The unequal air pressure will cause it to lose its balance and "upset." This is very much the sort of experiment that Lilienthal tried when he jumped from the top of a hill in his glider, and it is easy to imagine how much skill he must have required in balancing himself in order to prevent his crude contrivance from overturning. But now suppose that instead of dropping the piece of cardboard straight down, we give it a _forward push_ into the air. As the cardboard moves _forward_ it naturally creates more air resistance under the front than under the rear, and this unequal pressure will cause it to do a series of somersaults, before it reaches the floor. The same thing would happen to the bird or the airplane whose weight was evenly and equally distributed. Now since the air pressure is greater under the front of the cardboard, add a counterbalancing weight by dropping a little sealing wax at the center front. The dot that you made in the middle of the sheet is no longer its center of weight. The _center of weight_ has moved forward, and if it now corresponds to the _center of pressure_ the cardboard can be made to fly out and across the room without overturning. The whole problem of balancing a glider or an airplane is simply this one of making the center of weight coincide with the center of the supporting air pressure. Adding weight at the front of the glider is not the only way of doing this: perhaps the reader has already thought of another. Since the air pressure is caused by the weight of the cardboard and its forward motion, we could cut the sheet smaller at the front so as to lessen its air resistance there, or we could add a "tail" at the stern in order to create more air resistance at that end. Either of these plans would move the _center of pressure_ back until it corresponded with the _center of weight_, and so would complete the balance of our cardboard glider. In the bird's body all of these methods of obtaining balance are combined. His body and head taper to a point at the front in order to decrease the forward air resistance. The weight of his body is distributed more toward the front, thus counterbalancing any tendency to whirl over backward. His tail increases the stern resistance, thus helping to draw the center of pressure back to correspond to the center of weight. We begin to see some reasons why a man equipped with wings could never be taught to fly,--as well as how perfectly the form of the bird is planned to correspond to his mode of travel. No wonder the early experimenters with wings, finding themselves so utterly helpless and awkward, attributed the bird's ease and grace of carriage to "magic." [Illustration: DIAGRAM SHOWING THE ESSENTIAL PARTS OF AN AIRPLANE] The modern airplane is constructed with the most painstaking attention to this principle of _balance_. Next to it in importance is that of _wing construction_: that is, the size, shape and proper curve of the supporting planes. Here again the construction of the airplane follows very closely the general form of the bird. A large bird which flew very high would be found to have his wings arched high in front, where they would have considerable thickness, and sloping down very rapidly toward the rear, while their thickness rapidly diminished. This sort of wing has great lifting power, and it is the sort that is used on an airplane which is built to "climb" rather than to develop speed. As the arched wing cuts through the air it leaves above it a partial vacuum. Nature always tends to fill a vacuum, and so the airplane is drawn upward to fill this space. As the wings cut through the air a new vacuum is constantly created and so the airplane mounts higher and higher. The airplane is being carried upward by two forces: the air pressure beneath it and the vacuum above it which draws it up. The air pressure beneath it increases with the speed at which the airplane is traveling, and it has a tendency to press the wing into a more horizontal position, thus destroying its climbing properties. At the same time, when this happens, the thick front section of the wing presents a great "head resistance" which retards progress, and a very high speed becomes impossible. Wings of this type can never be used on an airplane which is intended to travel at high speed. They were used on the heavy bombing and battle planes of the Great War, for they are capable of lifting a very great weight. But on the scouting planes, where speed is essential, a totally different sort of surface was employed. Here the plane is very little arched and of almost even thickness, tapering only very slightly to the rear edge. It also tapers somewhat at the front, so as to lessen its "head resistance" as it cuts through the air. Such a surface creates little vacuum above it, and consequently has not a great lifting power. On the other hand it offers little "head resistance" and so permits a high speed. And right here it should be mentioned that a powerful motor does not in itself make a swift airplane, unless the wings are right,--for if the wings create a strong resistance _in front of the airplane_ they destroy speed as fast as the motor generates it. Remember that the lifting power of the airplane wing is made up of two factors. _First_, there is the resistance or the supporting air pressure created by the weight and speed of the wing; _second_, the arch of the wing creates a vacuum above it which tends to lift the airplane up. Now when for speed the arch is made very slight, the lifting power can still be increased by increasing the _area_ of the wing, thus adding to the upward pressure. Thus for certain war duties an airplane with very large, comparatively flat wings can develop both a very good lifting power and a very high speed. We have already mentioned the "head resistance" of the airplane wing. If the wing could strike the air in such a way as to sharply divide it into currents flowing above and below, there would be no head resistance. But the very arch of the wing in front gives it a certain amount of thickness where it strikes the air, so that instead of flowing above or below, a portion of the air is pushed along in front, retarding the progress of the airplane. This resistance is called by aviators the "drift." The best wing is the one which has the maximum lifting power with the minimum head resistance, or, to use technical language, the greatest "lift" in proportion to its "drift." Of course, not only the wing but all parts of the airplane offer resistance to the air. In order to reduce this total head resistance to the minimum, every effort is made to give the body or "fuselage" of the airplane a "streamline" form,--that is, a shape, such as that of a fish or a bird, which allows the air to separate and flow past it with little disturbance. For this purpose the fuselage of the airplane is usually somewhat rounded and tapering toward the ends, often "egg shaped" at the nose. The method of "wing warping" invented by the Wright brothers is still used on all modern airplanes to preserve lateral stability. The part of the wing which can be warped is called the _aileron_. There are two ailerons on every wing, one on each side at the rear, and they may be raised or drawn down by the action of a lever operated by the pilot. If the pilot feels that the left side of his machine is falling, he draws down the aileron on that side and raises the right hand aileron. The aileron which is lowered catches the air currents flowing beneath the wing on that side. At the same time the raised aileron on the right lessens the pressure under the wing on that side and so gives it a tendency to fall. In this way, in a fraction of a minute the wings are brought level again and lateral stability is restored. Whereas the old Wright biplane had an elevating plane in front of the main planes, most machines to-day have the elevating surfaces at the rear. By raising the "elevators" an upward motion is obtained, or by lowering them, a downward motion. [Illustration: WRIGHT STARTING WITH PASSENGER] Steering to right and left is accomplished by a rudder at the rear of the airplane body or "fuselage." This rudder may be turned to right or to left, working on a hinge. [Illustration: AN EARLY FARMAN MACHINE PRIOR TO START] CHAPTER III THE PIONEERS While the Wright brothers, lacking both funds and encouragement to continue their remarkable project, remained, from 1905 to 1908 in almost total obscurity--their wonderful flying machine packed away ignominiously in a barn,--in France a number of eager experimenters were working assiduously to outstrip them, and it was only by great good fortune that when Wilbur Wright arrived in France in 1908 he did not find himself beaten from the field. Actually the Wright machine was far in advance of the early French models, and although the French, with true spirit of sportsmanship, were quick to admit it when the fact was demonstrated, yet prior to 1908 they had no idea that such was the case, and were enthusiastically proud of their home-made models. Among the very first of the French pioneers of flight was that gallant little Brazilian, Santos-Dumont, whose exploits with the dirigible had done so much to popularize air sports. His name was a household word with the French, who literally lionized him. Impatient of the limited opportunities for adventure presented by the dirigible, Santos-Dumont cast about in his mind for some means of procuring a more agile steed on which to perform his aerial tricks. In 1904 he became deeply interested in the subject of gliding, and made up his mind to try a few gliding experiments of his own. Like everything else he had attempted his method of attacking this new problem was startlingly original. Lilienthal and the other gliders had all made their flights above the solid ground. Santos-Dumont liked the idea of rising from the water much better. He ordered built for him a glider of his own design for this particular purpose. On every clear day when the wind was favorable, the plucky little aeronaut was out, learning to use his new-found wings. His glider, which floated on the surface of the water, had to be towed swiftly for some distance by a boat in order to give it the initial speed which Lilienthal secured by taking advantage of the force of gravity in his downward jump from the hilltop. Once he felt his speed to be sufficient, Santos-Dumont gently inclined his wings upward to catch the air current. To the surprise of every one he was remarkably successful. He actually succeeded in soaring short distances, and after a series of efforts he acquired a fair amount of skill in the use of his glider apparatus. The next step was to attach some motive power to his flying machine. Before very long he had ready for trial a much more pretentious biplane glider, equipped with an 8 cylinder motor which drove a two-bladed aluminum propeller, and fitted with several original appliances to increase its soaring powers and its stability. In front was a curious arrangement resembling a box-kite, which was intended to fulfil the same purpose as the elevating plane which the Wright brothers placed in front of the two main planes of their machine. Santos-Dumont had experienced the same trouble as all the other gliders: the difficulty of keeping his machine in a horizontal position. The tiniest gust, blowing from one side or the other, was sufficient to cause it to lose its balance, and over it would topple sidewise. To overcome this obstacle the Wright brothers had adopted the ingenious method of wing-warping, imitated directly from the habits of birds. Santos-Dumont was not nearly of so scientific a turn of mind as the two great American pioneers. Without having gone so deeply into the subject, he determined to place upright planes between his main planes, to ward off gusts and increase the lateral stability. The idea was not a bad one, though far from being the best. In the summer of 1906 he flew with his glider successfully very short distances. In October of the same year he accomplished _a demonstration flight of 200 feet_ at Bagatelle, near Paris. At the present day when airplanes go soaring above our heads faster than express trains, making long, continuous cross-country flights, that journey of 200 feet seems humorous, but at the time it was the European record. It aroused a great deal of popular enthusiasm, for the French, with their vivid powers of imagination, were quick to see the possibilities in this new, heavier-than-air contrivance. At once the Brazilian set to work to outstrip this first achievement. This time his originality took an entirely new turn. Instead of the biplane type he decided on a monoplane, and he began laying out plans for a monoplane so tiny, yet so efficient, that it was destined to become famous. But it was several years before this miniature flier was ready, and so for a while the idol of the French public dropped almost completely out of sight. In the meantime others were up and doing in France. Henry Farman, who already had made his name famous in motor car racing, was the next to win popular acclaim for exploits in the air. Farman was known as a man of the most consummate daring, cool-headedness in emergency, and quick judgment. An Englishman by birth, he had resided all his life in France, where with his brother Maurice he had achieved an enviable reputation as a sportsman. Farman afterward designed and constructed airplanes of his own, but it was in one built by the Voisin brothers that he first took to the air. The Voisins were very ambitious indeed in their first airplane project. The machine which they built was both large and heavy, and possessed of many unscientific features. Like the Wrights' machine it had two large horizontal planes, in front of which was placed a small elevating plane, which could be inclined up or down to lift the airplane into the air or bring it to earth again. Unlike the Wright model it had a large "tail," or horizontal plane at the rear, intended to give it increased longitudinal stability. This feature represented an improvement. The Wrights had to keep their machine on the level by raising or lowering the front elevating plane in such a way as to counteract any pitching motion, but the tail of the Voisin biplane gave it a great deal more steadiness in the air. Fitted to the tail was a rudder, by which turning to right or left was accomplished. But the Voisin brothers had no wing-warping device on their large flier. Instead they used the upright curtains or planes between the main planes, which we have already seen on the machine designed by Santos-Dumont. Their airplane was equipped with an 8-cylinder motor, which turned a large propeller. In this large and unwieldy machine, weighing possibly 1400 pounds, Henry Farman made a short flight in a closed circuit in 1908. At the time it was the record flight in Europe, and the French people fondly imagined it was the best in the world. That same year Wilbur Wright arrived on French soil and showed them in a few astounding experiments what the Wright biplane could do. The successes of this tall, untalkative American, who had come over to France and with ease made the aerial adventures of Santos-Dumont and Farman seem like the first efforts of a baby learning to crawl, greatly as they surprised, and, perhaps, disappointed the French people, in the outcome had the result of spurring Frenchmen on to greater effort in the problem of airship design. Before the end of 1908 Henry Farman, in an improved Voisin, had wrested back the lost honors by flights which were longer than those made by Wilbur Wright. And other Frenchmen were hard at work. After building a number of machines and meeting with many accidents and failures, Blériot emerged in the summer of 1909 with a successful monoplane. At almost the same time the Antoinette monoplane made its appearance, and soon these two similar machines were pitted against each other in a famous contest. The London _Daily Mail_, with the intention of stimulating progress in aviation, put up a prize of £1000 for the first machine to fly the British Channel. In July, Blériot brought his monoplane to Calais; and Hubert Latham appeared as his antagonist, with an Antoinette machine. Both of the contestants were skilled pilots, and both were men of fearless daring. The feat which they were about to attempt required men with those qualities, for in these pioneer days of aviation it was not the easy task to fly the Channel which at first glance it might seem to be. Over the Channel the winds were almost always very severe, and they represented the greatest danger the airman had to face. The first airplanes had so small a factor of stability that it was almost impossible to fly them in even the gentlest breeze. The most intrepid aviators never once thought of attempting flight in unfavorable weather. To be overturned in crossing the Channel meant taking a big risk of death, and both Blériot and Latham realized that they were taking their lives in their hands in undertaking the trip. They had a long wait for calm weather, but on July 24th conditions seemed right for a start the next morning. Just at dawn Latham flew out across the sea and disappeared in the distance. Not very long behind him, Blériot, having tested with the utmost care every part of his little machine, climbed into the pilot's seat, and with a "Good-by" to the little group of mechanics and friends who stood about, sped away, hot on the trail. On and on flew Latham in his larger Antoinette monoplane, and the hope of victory began to loom big. Far out over the Channel however, his engine suddenly "went wrong," as engines in those days had a habit of doing, and the much feared thing happened: he began to fall. In a very few moments the plucky pilot was clinging to his airplane, as it floated for a few moments on the choppy sea. Before it could sink a vessel had hurried to the rescue, and Latham was hauled on board, disappointed, but safe. Blériot, meanwhile, was far from being sure of his course as he flew on steadily through the early morning haze. But his engine continued to run smoothly, and finally far ahead, the white cliffs of England began to emerge out of the distance. With joy in his heart the Frenchman flew proudly in over the land and brought his airplane to the earth in the vicinity of Dover Castle. He was greeted as a hero by the British and the glad message of his triumph was speeded back to Calais. Loth to be behindhand in airplane activities, America was also busily at work developing the heavier-than-air machine, and another famous name had by this time been added to that of the Wright brothers. By 1909 Glenn Curtiss with a group of distinguished co-experimenters had succeeded in constructing several very interesting flying machines. Curtiss' story is an interesting one. In 1900 he was the owner of a small bicycle shop in Hammondsport, New York. He had a mania for speed, having ridden in many cycling races, and it was he who first thought of attaching a motor to a bicycle for greater speed. He soon sprang into the limelight as a motorcyclist and a manufacturer of motorcycles. A small factory went up at Hammondsport, and achieved a reputation for the very good motors it turned out. Curtiss first became interested in flying through an order he received from Captain Thomas Scott Baldwin for a motor to be used in a dirigible balloon. He set to work on the problem of constructing a motor suitable for the purpose, and, as might be expected, he became fascinated with the possibilities of flight. Curtiss and Baldwin made some very interesting experiments with the dirigible. Then, in 1905, Curtiss made the acquaintance of Dr. Alexander Bell. The famous inventor of the telephone was engrossed in the study of gliding machines, and had been carrying on a series of experiments with kites by which he hoped to evolve a scientific airplane. To further these experiments he had called in as associates in the work two engineers, F. W. Baldwin, and J. A. D. McCurdy, while Lt. Thomas Selfridge of the U. S. Army was also greatly interested. Thus it came about that in the summer of 1907 this group of capable men formed what they were pleased to call the "Aerial Experiment Association," of which Curtiss was perhaps the moving spirit. The first machine built by the Association was christened the _Red Wing_, the second the _White Wing_; the third was called the _June Bug_, and it proved so successful a flier that on July 4th, 1908, it was awarded the _Scientific American_ trophy for a flight of one kilometer, or five-eighths of a mile. While, in France, Farman and the Voisin brothers, Latham and Blériot were pushing steadily along the rough road to aviation successes,--in America, the Wright brothers and Curtiss with his associates, were demonstrating to the public on this side of the water what flying machines could do. In fact, the airplane had definitely begun to assert its superiority as master of the air, and many eyes in all parts of the world were fixed on it and on the great future possibilities for which it stood. Everywhere, warm interest had been aroused, and, at least in France, the military importance of the heavier-than-air machine was coming to be realized. Now the time was ripe for the great public demonstration of the world's airplanes which took place at Rheims in August, 1909. The Rheims Meeting is probably the most memorable event in the history of aviation. It placed the work of a dozen or more earnest experimenters definitely in the limelight, and gave the chance for comparisons, for a summing up of knowledge on the subject of flight, and for a test of strength, which resulted in the mighty impetus to aerial progress which followed immediately afterward. Here at Rheims were gathered many famous flying men who already had made their names known throughout Europe and America. There were Farman, Latham, Paulhan, Blériot, Curtiss, and the three who flew Wright machines, the Comte de Lambert, Lefevre and Tissandier,--as well as many others, for there were thirty contestants in all. Many unusual feats delighted the spectators. Lefevre, a student of the Wrights, and up to that time unknown, amazed the assemblage by his wonderful aerial stunts. He circled gracefully in the air, making sharp, unexpected turns with the utmost skill, and winning round after round of applause. Curtiss and Blériot emerged as contestants for the speed prize over 10 kilometers, and after several breathless attempts in which records were made and broken, the honor was finally carried off by Blériot, who covered the distance of 10 kilometers (about 6-1/4 miles) in 7 minutes, 47.80 seconds. Curtiss replied by beating his famous opponent in the contest for the Gordon Bennett Cup, offered for the fastest flight over 20 kilometers; and Curtiss also was the winner of the 30 kilometer race. It was Farman, in a biplane of his own design, who surprised every one by his remarkable performance, and turned out to be the victor of the occasion. Flying for three hours without stopping, round the course, he covered 112 miles without the slightest difficulty, and was only forced to make a landing because of the rapidly approaching dusk. For his feat he was awarded the Grand Prize, and was hailed as the most successful of all the contestants. Finally Latham, in an Antoinette monoplane, proved he had the machine with the greatest climbing powers, and carried off the Altitude prize on the closing day of the meeting. Among those who looked on at the famous Rheims Meeting of 1909 there were none more keenly and intelligently interested than the representatives of the French military authorities. They had come for two reasons: to ascertain at first hand which were the best machines and to order them for the French Government; on the other hand, to encourage to the fullest extent possible all those men present who were earnestly working in the interests of aviation. France was ready and willing to spend money freely for this purpose, and the Rheims Meeting resulted in orders for machines of several makes. Some of these were regarded as having great possibilities from a military point of view; and others, though not looked on so favorably, were purchased as a sign of goodwill and support to future experiment. It was this far-seeing patronage which paved the way for France's later aerial triumphs, for it gave her a diversity of machines and a devoted coterie of workers all following original lines of experiment. Let us glance for a moment at the little group of machines which stood out by their merits most prominently at that Rheims Meeting of 1909, and which gave the greatest promise for the future. To-day they seem antiquated indeed, but for all their rather curious appearance they were the legitimate forefathers of our powerful modern airplanes. Among the biplanes, those especially worthy of note were the Farman, the Wright, and the Voisin; while the Blériot and Antoinette monoplanes gave a most excellent account of themselves. Farman, who had first learned to fly in a machine designed and built by the Voisin brothers, was far from satisfied with his sluggish, unmanageable steed and at once set to work on a design of his own. His one idea was to construct a biplane of light weight, speed and general efficiency. He did away with the box-kite tail of the Voisin model and substituted two horizontal tail planes with a vertical rudder fitted between them. Instead of the vertical planes or "curtains" between the main planes by which the Voisins attempted to preserve the lateral stability of their airplane, Farman adopted the "wing-warping" plan of the Wrights in a somewhat modified form. The Wright machine, it will be remembered, had wings whose rear portions were flexible, so that they could be drawn down at the will of the pilot. If the latter felt that the left side of his machine was falling he simply drew down or "warped" the rear edges of the wings on that side. The air rushing under the wing was blocked in its passage and the greater pressure thus created forced the wing upward on the left side until balance had been restored. Acting on this principle, Farman attached to the rear edges of the main planes at each side a flap, or as it is called to-day, an _aileron_, which worked on a hinge, so that it could be raised or lowered. Another novel feature of this first Farman biplane was its method of starting and landing. Below the planes had been placed two long wooden skids, and to these small, pneumatic tired wheels had been attached by means of strong rubber bands. In rising, the airplane ran along the ground on these wheels until it had acquired the momentum necessary to lift it into the air. When a descent was made, the force of contact with the ground sent the wheels flying upward on their flexible bands, and allowed the strong skids to absorb the shock. This underbody or _chassis_ was a distinct improvement on anything that had yet been devised, for it was light in weight and efficient. In one other important respect the Farman machine was superior to all those demonstrated at Rheims in 1909, and that was in its engine. Airplane engines up to this time had been nothing more or less than automobile engines built as light in weight as possible. But in France a new engine had made its appearance, designed especially for airplane needs. Hooted as a freak at the first, and rejected by experts as "impossible," it carried Farman round the course on his three hour flight without a hitch and made him the winner of the Grand Prize. This remarkable engine was the Gnome and the reason for its excellence lay in its unusual system of cooling. The overheating of his motor was a thorn in the flesh of many an early aviator. An engine which gave good service in an automobile would invariably overheat in an airplane because of the constant high speed at which it must run. Now motor car engines of whatever type, and whether water-cooled or air-cooled, had fixed cylinders and a revolving crankshaft. In the Gnome motor the cylinders revolved and the crankshaft was stationary. Flying through the air at tremendous speed they necessarily cooled themselves. This was the secret of the perfect running of the Farman biplane. Though Farman had been the first to recognize the merits of the Gnome and install it in his machine, he was not the last, for after the Rheims Meeting it rapidly became the favorite of practically all builders. Next to the Farman, the Wright machine was probably the best for all-around service of the many demonstrated at the great meeting. Its one greatest disadvantage was the fact that it had to be launched from a rail. It carried no wheels--merely skids for landing--and so to gain initial momentum it had to be placed on a small trolley which ran down a rail. Such a method of gaining speed was exceedingly complicated, and the question at once arises: What would the pilot do if forced to make a landing far from his starting point? Of course it would have been quite impossible for him to have risen into the air for a return trip, and his machine, though in perfect condition, would have to have been packed and carted back home. The Voisin biplane, though improved since Farman had piloted it in 1908, was still in 1909 an overly heavy, slow flying machine, more or less difficult to steer. It still had its "box-kite" tail and its upright curtains between the main planes. And it carried a rather weighty landing chassis built of hollow metal tubing, to which were attached pneumatic-tired bicycle wheels. Small wheels were also placed under the tail, to support it when running along the ground. The Blériot monoplane could have claimed the honors for _simplicity_. It had a body built up of light woodwork, over part of which fabric had been stretched. On either side of the body extended the two supporting planes, supported above and below by wires. In the front of the body was the engine and at the rear extremity a small stabilizing plane. At the ends of the stabilizing plane, on either side, were two small planes which could be moved up and down. They took the place of the front elevating plane employed on the other machines. Just behind the stabilizing plane was the vertical rudder, which turned to right or left. The wings of the Blériot had the Wright brothers' wing warping arrangement. The pilot sat just behind the engine, operating the controls. Larger in wing span and longer in body than the Blériot was the Antoinette monoplane. Like the Blériot it had its elevating planes at the rear, and carried its engine in the bow. Instead of the wing warping device it made use of movable flaps or _ailerons_ at the rear edges of the wings. Another idea had been incorporated in this machine for the purpose of maintaining lateral stability. Its wings, instead of extending in a horizontal position from the body were inclined slightly upward,--a plan which met with serious condemnation from the engineering experts. These five then, were the machines which claimed most attention in 1909, although many others,--as for instance the R. E. P. monoplane, built by M. Esnault-Pelterie, and the Breguet biplane--were flown at the famous meeting. The Rheims event had been hugely successful, and the news of the splendid achievements of the airplane spread like wildfire throughout the world. Smaller meetings were arranged for in other cities, and everywhere the great aviators were called for to give exhibition flights. In September Santos-Dumont came once more before the public with the tiniest monoplane in existence, a little machine which he called the _Demoiselle_, and in a series of experiments proved its remarkable capabilities. Santos-Dumont had been residing for some time at St. Cyr, where he had worked on his designs for the _Demoiselle_. One of his aviator friends, M. Guffroy, was also experimenting at Buc, five miles away. The two men agreed that the one who first completed an airplane should fly in it to the home of the other and collect £40. In 6 minutes and 1 second Santos-Dumont covered the five miles on the 14th of September and claimed his reward. Orville Wright at about this time was exhibiting his airplane in Berlin and winning new laurels before the Crown Prince and Princess of Germany. By the middle of October he was in France, and was present at the Juvisy Meeting, when the Comte de Lambert, leaving the course unexpectedly, made his sensational flight over Paris, circling round the Eiffel Tower at a height of 1,000 feet. Paris was filled with amazement and delight at the sight of an airplane soaring over the city. It was almost an hour before the Comte de Lambert, flying with the greatest ease, arrived once more at the course, to be overwhelmed with congratulations. [Illustration: WRIGHT MACHINE RISING JUST AFTER LEAVING THE RAIL] [Illustration: AN EARLY WRIGHT MACHINE, SHOWING ITS METHOD OF STARTING FROM A RAIL] On November 3rd, Henry Farman made a world's record of 144 miles in 4 hours, 17 minutes and 53 seconds, wresting from Wilbur Wright the coveted Michelin Cup. In December Blériot attempted an exhibition of his monoplane in Constantinople, but his machine lost its balance in the severe wind which was blowing and came crashing to earth. Though severely wounded, the great aviator recovered rapidly, justifying the oft-repeated superstition that he was possessed of a charmed life. [Illustration: _Copyright Underwood and Underwood_ THE PROPELLER DEPARTMENT IN ONE OF THE GREAT CURTISS FACTORIES] Thus the year which had meant so much in the forward march of aviation drew to a close. Beginning at Rheims, the reputation of the heavier-than-air machine had spread in ever widening circles throughout all civilized lands. Most important of all, the military authorities of several nations had opened their eyes to tremendous importance of the airplane as an implement of warfare, and their realization of this fact was destined to bring about new and weighty developments within the next few years. Among the great European states only one nation slept while the rest were up and doing, and she saw the day when, with the shadow of war looming on the horizon, she had cause for bitter regrets. The beginning of 1910 saw the famous aviator Paulhan in the United States for a series of exhibition flights. On January 12th he made a world's record for altitude, climbing at Los Angeles to a height of 4,140 feet, in a Farman machine. In the Spring there occurred in England a memorable contest between Paulhan and a young flier who up to that time was unheard of, but who rapidly made a reputation for himself in aviation. The London _Daily Mail_, which had already done so much to arouse enthusiasm for the airplane in the British Isles, now offered a prize of £10,000 for the first cross-country flight from London to Manchester. There arose as England's champion Claude Grahame-White, and Paulhan with his Farman biplane was on hand to dispute the honors with him. The distance to be covered was about 183 miles, and the task seemed almost impossible, largely owing to the nature of the country over which the flight must be made. It was rough and hilly and thickly sprinkled with towns, making the task of a forced landing a very perilous one. Engines in 1910 were none too reliable and were apt to play strange tricks. To be forced to descend over a town or in rough country meant a chance of serious accident or death. Rough country moreover is apt to be windy country, with sharp, unlooked-for gusts blowing from unexpected quarters. It was these above all things which filled the airman's heart with dread, for he knew only too well the limited stability of his pioneer craft. Late in the afternoon of April 27th, Paulhan, whose biplane, in perfect repair, was awaiting him at Hendon, near London, ascertained that the wind was favorable, and at once rose into the air and started on his long trip. Grahame-White had assumed that it was too late in the day to make a start, and had left his machine, all ready for flight, at Wormwood Scrubbs, intending to make a start in the early morning. Shortly after six the news was brought to White that Paulhan was on his way, and he immediately rushed to his starting point and hurried after his rival. Paulhan had studied every inch of the ground and knew what conditions to expect. His earlier start gave him a great advantage, for he managed to get farther before nightfall, and also before any adverse winds arose. With darkness both pilots were forced to make landings, but Paulhan was far ahead, and the prospect of victory began to wane for the plucky young English flier. In the emergency he determined on a desperate attempt to overcome his handicap. Night flying then was a thing unheard of, but Grahame-White prepared to try it, however risky. At half past two in the morning, by the wan light of the moon he arose from the field where his machine had been landed and flew off into the murky night. Disappointment awaited the dauntless pilot, however. He had a stern struggle with the wind, his engine began to give trouble, and finally he was compelled to come to earth. Paulhan got away at dawn and being the more experienced pilot of the two, managed, after a sharp tussle with the wind, to arrive intact at his destination. He was greeted with wild enthusiasm and was indeed the hero of the day. But England was not without gratitude to her defeated airman, who in the face of enormous difficulties, had persisted so gallantly in his effort to uphold his country's honor in the records of aviation. Though official England was slow to recognize the airplane's claims, the British public showed keenest interest in all the exploits of their sportsmen of the air, and before long there was quite a fair-sized group of such men demanding attention. America also had a remarkable feat to record in the summer of 1910. The New York _World_ had offered a $10,000 prize for a flight down the Hudson River from Albany to New York. The difficulties were even greater than those of the London-Manchester contest, for here the airman had to fly the entire distance over a swift stream. The high hills on either side meant increased peril, for there were sure to be powerful wind gusts rushing out between the gaps in the hills and seeking to overturn the machine. If the engine should give out, there was no place to land except in the water itself, with slight chance of escape for either the pilot or his airplane. Nevertheless, Glenn Curtiss, whose accomplishments at the Rheims Meeting we have already witnessed, determined to try for the prize. His machine was brought from Hammondsport to Albany ready for a start, and on May 31, after a long wait for favorable atmospheric conditions, he was on his way. A special train steamed after him, carrying newspaper reporters and anxious friends, but he left it far in the distance while he flew swiftly down the Hudson. Villagers and boatmen waved and shouted to him as he passed. At one point he encountered an air "whirlpool" that almost sucked him down, but he succeeded in righting his machine and getting on his way again. Near Poughkeepsie he made a landing to obtain more fuel, and from there he flew straight on to his journey's end, reaching New York City and descending in a little field near Inwood. In July of 1910 came the second big Rheims Meeting, to show what unprecedented advances had been made in one short year. Almost 80 contestants appeared, as compared with the 30 of 1909. Machines were in every way better and some very excellent records were made. The Antoinette monoplane flew the greatest distance (212 miles), and also reached the greatest height; while a new machine, the Morane monoplane, took the prizes for speed. Meanwhile the French Army had been busy training aviators and securing new machines. In the Fall these were tried out at the Army Maneuvers in Picardy, and for the first time the world saw what military airplanes really could accomplish. In the sham warfare the army pilots flew over the enemy's lines and brought back astonishingly complete reports of the movements of troops, disposition of forces, etc. The French military authorities themselves, enthusiastic as they had been over the development of the airplane, had not anticipated such complete success. They were delighted with the results of their efforts, and a strong aerial policy was thereupon mapped out for France. England at this date possessed _one_ military airplane, and it was late before she awakened to the importance of aviation as a branch of warfare. Germany, Italy, Russia, and America were looking on with keen interest, but for a while France maintained supremacy over all in her aerial projects. By the end of the following year she had over 200 military machines, with a competent staff of pilots and observers. To follow the course of aviation achievement we must now go back to England, where in July, 1911, another big _Daily Mail_ contest took place. This time the newspaper had put up a prize of £10,000 to be won by flying what was known as the "Circuit of Britain." This had been marked out to pass through many of the large cities of England, Scotland and Ireland. There were seventeen entrants for the contest, which was won by a lieutenant of the French navy, named Conneau. Cross-country flights were growing longer and longer, keeping pace with the rapid strides in the development of the airplane. Still another contest during 1911 was the "Circuit of Europe," which lay through France, Belgium and England; while a flight from Paris to Rome and one from Paris to Madrid served to demonstrate the growing reliability of the aircraft. Money had always flowed freely from French coffers for this favorite of all hobbies. At the Rheims Meeting in October of 1911 the Government offered approximately a quarter of a million dollars in prizes for aerial feats and in orders for machines. Representatives from many countries visited the meeting to witness the tests of war airplanes. In the two years since the first Rheims Meeting many vast changes had taken place. Pilots no longer feared to fly in high winds; machines were reliable, strong and swift. A number made non-stop flights of close on to 200 miles, and showed as well remarkable climbing abilities. It was the Nieuport monoplane which led all others at this Rheims Meeting. To-day the name of Nieuport is familiar to every one, for the little scout machines carried some of the bravest pilots of France and America to victory in the air battles of the Great War. Even in 1911 the Nieuport monoplane was breaking all records for speed. Carrying both a pilot and a passenger it flew as fast as 70 miles an hour at Rheims. Another new machine that attracted attention was the Breguet biplane, a heavy general service machine weighing 2420 pounds and carrying a 140 h. p. Gnome motor. The Gnome had so far outdistanced all competitors that it had virtually become the universal motor for airplanes, and, many of those seen in 1911 were equipped with it. Since then vast improvements have been made in stationary engines but at that time they almost entirely failed to meet the requirements of light weight, high power and reliability. One development in the biplanes of 1911 cannot be passed over, for it bears a very interesting relation to their efficiency as war machines. Any one who has seen a photograph of one of the early biplanes must have been struck by the curious kite-like appearance it presented, due to the fact that it had no _body_ or fuselage, but only two large planes, connected by strong wooden supports, and usually with a seat for the pilot in the center of the lower plane. It was in the monoplane that a car or airplane body first made its appearance, and to it the wing surfaces of the monoplane were strongly braced with wires. Many of the biplanes of 1911 had adopted the idea and in consequence began to take on a more modern appearance. It was a thoroughly good idea, for by means of its greater stability and strength, protection for the pilot and general efficiency were obtained. Biplanes of this type now carried their engines in the fuselage bow with the pilot's seat just behind it, while instead of the _front_ elevating plane of the earlier models, the elevating surfaces were at the rear of the fixed tail plane. The Breguet was one of these progressive type biplanes of 1911. Constructed very largely of steel, it had a long, tapering body with its controlling planes--rudder and elevators--at the rear. Instead of a number of wooden supports between the planes the Breguet had exactly four reliable struts. Henry Farman developed a military biplane in 1911 which had one particularly new feature. Instead of the upper main plane being placed exactly above the lower it had been moved slightly forward or "staggered"--giving it an overhang in front. The idea was that this gave a greater climbing power and was helpful in making descents, though the point has never been satisfactorily proved. Until 1911 Germany had pinned her faith almost wholly to the Zeppelin as the unit for the aerial fleet which she had hoped to build up, and she had confidently expected it to prove its superiority to the heavier-than-air machine in the event of war. No funds had been spared to rush the work of designing and constructing these huge air monsters. Carefully and quietly the perfecting and standardizing of the Zeppelin under government supervision had moved forward, and German engineers had not been behindhand in designing engines particularly suitable to aircraft. While France was amusing herself with the clever little monoplanes and biplanes of the pioneer days--machines which could fly but a few yards at low altitude, Germany, possibly with the dream of world conquest tucked away in her mind, was sparing no expense to get ready her fleet of lighter-than-air craft. Imagine her chagrin when the feeble winged birds of 1908 and 1909 became the soaring eaglets of 1911, swiftly circling the sky, swooping, climbing and performing aerial tricks which made the larger and clumsier Zeppelin appear as agile as a waddling duck. Whatever the feelings of the German military authorities were on the subject, they wasted no time in crying over spilt milk, but at once began a policy of construction by which they hoped soon to outstrip their brainier French neighbors. As in everything German, _method_ was the characterizing feature of the airplane program they instituted. France had sought to encourage makers of all types of planes, and thus obtain a diversity of machines of wide capabilities. The plan did not appeal to Germany. From the very beginning she aimed at reducing everything to a fixed standard and then turning out airplanes in large numbers. When the War broke out it seemed for a time that she had been right, but it was not long before she looked with sorrow upon the sad lack of versatility of her fleet of standardized biplanes. They were hopelessly outdistanced and outmaneuvered by the small, fast fighting machines of the French, while they were by no means so strong as the heavy service planes the French could put into the air. Italy, Austria, Russia, America and Japan began also to make plans for the building of aerial fleets about 1911. The Italian Government relied at first on machines secured from France, or on those copied from French designs. Soon her own clever engineers began to be heard from and she was responsible for developing several of the powerful modern types. Russia would scarcely seem a country where aerial progress might be expected, yet she has given a good account of herself in aviation, and one of her machines, the giant _Sikorsky_ did splendid work on the several fronts during the war. I. I. Sikorsky, the inventor of the big Sikorsky machine was a little while ago merely a clever student at the Kieff Polytechnic. Like many other young men he dreamed of aerial conquest, but received little encouragement in carrying out his projects. At twenty-four, however, he became a student aviator, and almost immediately began work on original airplane designs. He succeeded in building a small monoplane which in some ways resembled the Blériot, except in its habits of flight. In these it was quite balky, refusing to fly except in short hops and jumps. Sikorsky's friends good-naturedly nicknamed it _The Hopper_. But the young student was not one wit daunted. He plugged along steadily at new designs, and in the autumn of 1910 he actually took to the air in a tractor biplane of his own construction. Several other machines of somewhat the same type followed, and his efforts finally won the attention of the great Russo-Baltic Works. They offered him financial assistance to carry on his study of the airplane problem. With this backing Sikorsky moved forward to sure success. In the meantime he had secretly prepared plans for an enormous airplane which at first he dared not divulge for fear of ridicule and disappointment. Finally he took courage and laid them before his friends at the Russo-Baltic Works. Whatever they may have thought of his wild scheme of air supremacy they consented to give it a tryout, and in the Spring of 1913 the first of the giant "Sikorsky" machines stood awaiting a flight. It was viewed with grave misgivings by a number of experts, but to their frank surprise it took to the air with ease and flew well. The sight was a strangely impressive one. In wing span the big machine measured almost 92 feet, while the body or _fuselage_ was over 62 feet long. The weight of the amazing monster flying machine was 4 tons. In the forward part of the fuselage cabins had been fitted, with a small deck on the bow. The fuselage construction was of wood, with a strong 8-wheeled landing chassis beneath it. Four 100 h. p. German "Argus" engines, driving four tractor propellers sent it racing triumphantly through the air. Its weight lifting ability was enormous, and it made a world record for flight. Prodigious as this first great master of the air had seemed it was followed in 1913 by one still larger. The new machine was to the fullest extent an aerial wonder. Its enormous body consisted of a wooden framework covered with canvas, and in its interior a series of cabins were provided. There were three decks: the main one in the center of the fuselage, designed to carry heavy armament of machine guns and a searchlight; a small deck at the stern; and one set in the undercarriage, where additional heavy armament could be placed. Only a few months before the storm of war broke over Europe this Air Leviathan was born, and at the time no one suspected it would so soon be called into active service. In the Spring of 1914 it made flight after flight, scoring a succession of triumphs by its record breaking performances, and winning for its designer a decoration from the Emperor. Sikorsky was a man of wealth but so recklessly did he lavish his personal funds on his airplane ventures that on many occasions he came very near to want as a result. It was no unusual thing to see him during those years of reckless experiment, braving the bitter winter weather of Russia in threadbare garments, shivering, but grimly and sternly determined. Then came the War, and at the first call his machines were ready to prove themselves in the battle against the Hun. CHAPTER IV THE AIRPLANE IN THE WORLD WAR Picture to yourself a scene outside one of the Allied hangars or airplane sheds, just back of the front lines, while the Great War is in progress. It is early morning, gray and chilly. Small fighting machines, which their trusty mechanics have carefully gone over for the tiniest flaw, now stand ready to take to the air. Pilots, wrapped in their heavy clothing--leather jacket, helmet and overcoat, gloves, goggles and muffler--prepare to face the frigid atmosphere above the clouds. The whirr of the motor, a short run over the ground, and up they go, one by one, until they become so many blackbirds, driving and looping and skimming through the sky. Over in this corner is a large reconnaissance machine, with pilot and observer, waiting to ascend. It is one of a squadron that will fly over the German lines to take photographs of the enemy's positions. With its rapid-firing machine guns it is prepared to give battle to the swifter enemy craft that will flash out to challenge its onward flight. Its rôle is a difficult one. It cannot climb to safety as the fighting machine can do and then swoop down on its enemy from a favorable height. Its duty is to bring back accurate views of the territory on the other side of No Man's Land. No matter what the dangers, it must fly straight on, sticking close enough to earth to accommodate its camera's range, and deviating as little as possible from its course, though the enemy's speed scouts blacken the air with bullets and the anti-aircraft guns spit at it maliciously from below. All the machines in the squadron may not return, and there will be vacant chairs at the dinner table to-night when those pilots who have braved the stern hardships of the day relate their little experiences with the Hun. But those who do come back will bring information which will enable the Allied commanders to plan with intelligence the next move in the battle that is raging. A tour of inspection would disclose still other machines, large and small, each designed and equipped for its special duties over the lines. There are heavy, slower-flying day "bombers," and--silent this morning but waiting patiently for the curtain of night to descend,--enormous night bombing machines, the fiercest and hugest of all the great birds of the flying force. To-night, under cover of darkness these machines will speed upon their way, far over the enemy's lines. They carry fuel for a journey of many hours' duration, and heavy bombs which they will drop upon railway junctions, ammunition factories, staff headquarters and important positions deep in the territory of the Hun. Before they turn their noses homeward they will have crossed over the borders of Germany, and along their silent course fires will shoot up and enemy supplies and storehouses will be smoldering ruins when day breaks. Unlike the night bombing machines of the Germans these great Allied aircraft will not drop their missiles upon open towns along the Rhine, nor will they leave behind them any toll of little children and civilians maimed and killed by their brutality. Their instructions are to bomb military objectives only, and when they have done that they will fly back silently through the night, passing over quiet villages and towns, where the sleeping inhabitants never will know that the great blackbirds have hovered so close to them. When the War broke out airplanes were not planned so carefully nor equipped so fully for their special duties as they are to-day. Nobody foresaw exactly what those duties would be, and nobody once dreamed that the battalions of the air would play the tremendous rôle they have played in deciding the great struggle. Even Germany, who had been secretly planning and working and preparing for so long, had very little conception of the actual importance of her heavier-than-air machines. She neglected to use them entirely when she began her swift stride across Belgium. That piece of neglect lost her the prize, for the plucky Belgians, seizing the opportunity, marshalled their air forces, a small handful of airplanes, and used them to good advantage in discovering the intentions of the enemy. By means of her air force, Belgium was enabled to hold back for awhile the onrushing tide of the Hun armies, until France could bring her men into the field and the "contemptible little army" of Britain could be hurried across the Channel. As the air forces were the deciding factor in that first great onslaught, so they have remained during the whole struggle. They began as mere scouting machines, but they have taken upon themselves more and more duties, until at the present time they are used for a multitude of purposes, and are fitted with the most perfect equipment to carry out their various ends. Airplanes have often been called the "eyes of the army," but in war it is not sufficient to be able to _see_ what the enemy is doing or is about to do. You must also be able to keep him from knowing what your plans are. So, there are the machines whose duty is to "see" and those whose duty is to "put out the eyes of the enemy." These latter must keep an eternal vigilance over the lines, on the lookout for enemy craft. When one is spotted they dash out after it, pursue it back to its lines and prevent it from performing its mission of reconnaissance. Nor are they satisfied merely to drive it off, they follow and give fight. Over there against the sky you see a little puff of smoke and flame that goes shooting down to the horizon. It is an enemy plane that will never again come spying upon Allied troops. Perhaps a group of fast German fighting machines dart out unexpectedly to avenge it, and then there is a terrible battle in the clouds, with every machine that is in the air hurrying to the skirmish. You try to follow their swift movements as they loop and dart and dive, but all you can see is a rapid confusion of wings, and now and then a machine that separates itself from the general mêlée and goes crashing to earth. Not the least dangerous of the many services the airplane is performing is that of the artillery "spotter." It belongs to some particular battery whose guns are thundering away at the enemy. Hovering above No Man's Land, where its position is a trifle too exposed to be comfortable, it radiographs back to the gunners the exact locations of important objectives, then watches the firing and reports the results. Thanks to it the big guns do not speak in vain, and almost every shot is a direct "hit." And then there are the dreadnaughts of the sky who actually take part in an attack, flying low over the lines and attacking the enemy infantry with guns and with death-dealing bombs. They must run the gauntlet of the enemy's fire, but on the other hand they spread terror and confusion in the ranks of the soldiers massed below, distracting their attention and leaving them open to the surprise of a sudden onslaught of Allied troops. There are other machines which help in an attack by keeping the various parts of the long line in close communication with each other, so that all efforts are in unison. Their duties correspond in a way to those of the swift horseback rider we read of in the stories of old wars, who sped with news of great import from one commander to another. Only that the airplanes of to-day are so much more efficient than the gallant horseback rider of old, that although the line stretches across a nation, it can act as a man when the moment comes for a big "push." Long before the war Germany had been busy turning out airplanes in large numbers in her factories, and in August, 1914, her air force was far superior in numbers to that of her great opponent France. She fondly imagined that she would be able with the greatest ease to put out her enemy's eyes, but in this she failed utterly. In spite of her military program of construction, according to which airplanes were turned out as if by clock-work, there was something wrong with her calculations. It is amusing to look back and see how German "method" had been carried to the absurd point of defeating itself. In manner truly characteristic, the Hun had standardized his airplane down to the last bolt. Every machine turned out was of exactly the same pattern, and built up of exactly the same parts--parts which could be manufactured in large quantities and put together with unusual speed. It was certainly _system_ raised to the _n_th degree. And the machines themselves were good enough--sturdy biplanes intended to be maids-of-all-work over the front lines. Yet in a little while after the fighting had begun, Germany withdrew them in more or less chagrin, and set herself to constructing others of varied patterns. They were well made and splendidly equipped, but they were not sufficiently _specialized_ for the many different kinds of work they were called on to perform. France had a motley array of airplanes of every size, shape and make when the war broke out. They had varying systems of control, so that a pilot who flew one with ease was nothing more than a novice when he stepped into another. He did not know how its new set of levers operated, nor how the plane would behave in the air. Moreover, the parts for these French airplanes and for their engines had been specially designed by each maker, and were quite unsuitable for any other type of machine. The result was that when a machine had to be repaired at the front, it was "laid up" for a long time, while the special part it required was being ordered and made for it. When finally it arrived, very often there had been some mistake, and so there was another long period of uselessness. France had prided herself on her versatility in airship design. She now had cause to regret it as she viewed the almost helpless confusion it had caused in her air service. Her machines, moreover, were much inferior to the German in armament, speed and climbing gauges, cameras, and all the hundreds of accessories which gave the German machines their initial advantage. But experience is the best teacher, and no sooner had she seen wherein she fell short than dauntless France mustered all her resources to correcting past mistakes. Order was brought out of confusion, and it was only a very little while before the German war lords had need to look to their laurels, for the Frenchmen were far outstripping them in the air. There was one "accessory" which the airplane of the Hun lacked, and which all his mechanical skill and ingenuity were not able to provide: _a pilot with the dash and daring of the French!_ Even in those first dark days when the French planes were the equals of their adversaries neither in numbers nor in capabilities,--a continuous stream of gallant French pilots took to the air and proved that they could surprise and outmaneuver their slower-thinking opponents. While they held the line in their inferior craft, French manufacturers were rushing newer and better equipped machines to reenforce them. Great Britain was far behindhand in aircraft production when the trumpet of war sounded,--in fact, her air force was considered a negligible quantity by friend and foe alike. By dint of persevering search she managed to scrape up a small group of planes of many makes and for the most part antiquated. She sent them--along with her "contemptible little army "--to France, and there they succeeded in holding their own during the first great German push. When the Stories of heroic fighting against hopeless odds, of British airmen flinging their lives in challenge against the foe in the great air struggle, began to reach home, the British lion repented his tardiness and a program of aircraft construction on a large scale was instituted without delay. In carefully standardizing those first airplanes there was one point which the crafty Germans overlooked: which is, that you can't make a dray horse run fast, nor a race horse draw heavy burdens. The same thing holds good with the "steeds" of the air. A plane which is designed for great speed is never as good a burden bearer as one which is built to lift heavy weights at the expense of swiftness in flight. As soon as the duties of the airplane began to be specialized, the airplane itself began to appear in certain definite types. Now of course the duties of the airplane in wartime are numberless, but out of the early confusion _three_ types of machines were finally evolved, which, with the addition of equipment, such as a camera, machine guns, etc., are suitable for practically any sort of work over the land. They are: 1. The high speed fighting machines. 2. The reconnaissance machines. 3. The bombing machines (including the day and the night bombers). Of all military airplanes there is none so fond of "aliases" as the high speed fighting machine. Possibly in order to baffle the uninitiated, or to surround itself with an atmosphere of uncertainty and romance, it goes by first one title and then another. Most often we hear it called a _speed scout_, perhaps for the reason that _it does no scouting!_ At other times it masquerades proudly under the fine French titles of "Avions de Chasse" or "Avions de Combat." It is referred to as a "chaser," a "pursuit machine," a "battle plane" and a "combat machine"--but whatever it is _called_, in type it is the small, fast airplane, usually a single seater, quick in climbing, agile as an acrobat, able to "go" high and far,--for its duty is to run every enemy machine out of the sky and sweep the board clean before the heavier service machines begin their tasks of the day. It should be able to reach a height of from 18,000 to 23,000 feet, or in the language of the air, it must have a high "ceiling." From altitudes so tremendous that they awe the mere earthly pedestrian it swoops down upon its unsuspecting victim, opening upon him a stream of machine gun fire. For its pilot is also a skilled gunner and a crack shot. Upon his ability to maneuver his machine swiftly and cleverly and hit his target unerringly depends his own life and the life of a costly military airplane. The reconnaissance machines and the bombing planes may do valuable service,--and indeed they invariably do--but it is the "speed scout" that covers itself with glory. The reason is that its career brings it nearer to the "personal combat" of the knights of old than anything in modern warfare. Driving his swift Nieuport scout as a knight would have ridden his charger, the beloved Guynemer went forth to challenge the German fighters,--and other Frenchmen and Englishmen and Americans have followed him. It is a fact beyond all question that this branch of the service has produced some of the most truly unselfish and heroic figures of the whole war. The "speed scout" pilot did not need to be a man deeply versed in military affairs--as for instance the pilot and observer of the reconnaissance machine must be,--but he did need dauntless courage, unfailing nerves of steel, dash and daring and contempt for his own safety. So wherever the "speed scout" has blazed its trail of fire across the sky, there have sprung up the names of men whose heroic deeds have made them the idols of the whole world. Usually they have been very young men--young enough for their ideals to have kept fresh and untarnished from the sordid things of life, and thus they have written their names among the immortals. [Illustration: _Copyright Underwood and Underwood_ A PHOTOGRAPH OF NORTHERN FRANCE TAKEN AT A HEIGHT OF THREE THOUSAND FEET] Less appealing to the imagination, perhaps, but no less vital to the progress of modern warfare, is the slower flying reconnaissance craft. This machine is always a two-seater, and sometimes a three, for at the very minimum it must carry a pilot and an observer, while a gunner is a very convenient third party in case of an attack from enemy scouts. This type of machine is used for photographic work, for artillery "spotting," and for many general service duties over the lines. In the early days of the war it was customary for the photography airplane to be escorted on its mission by a group of fighting machines, who hovered about it and engaged in battle any airplanes of the enemy that might seek to interrupt its important work. But the last year or so have brought many improvements in airplane construction and it has been found possible to build a machine which can not only carry the heavy photographic apparatus and a couple of machine guns, but which can also travel at a good speed and climb fast enough to escape from the anti-aircraft guns. Instead of the rather helpless, clumsy, slow-flying reconnaissance machines of the early part of the war, we now have powerful "aerial dreadnaughts," which no longer need to run away, but can stay and fight it out when they are interrupted in the course of their air duties. Military photography is one of the most fascinating of the side issues of the war. Before the day of the airplane it was the scout or spy who worked his way secretly into the enemy's lines and at great personal risk,--and often after many thrilling adventures, if the story books are to be believed--brought back to his commanding officer news of the disposition of troops, etc., in the opposing camp. To-day the spy's job has been taken away from him. No longer is it necessary for him to creep under cover of night past the guard posts of the enemy. A big, comfortable and efficient airplane flies over the ground by broad daylight and collects the necessary information a great deal better than the spy ever could have secured it. [Illustration: _Copyright Underwood and Underwood_ AN AIRPLANE VIEW OF THE CITY OF RHEIMS, SHOWING THE CATHEDRAL] A reconnaissance camera has very little in common with a kodak. The observer does not tilt it over the edge of the machine, focus it on some interesting object and "snap" his picture. As a matter of fact it works more after the manner of a gun. It is fixed in the bottom of the airplane, facing downward. The observer has been instructed before leaving the ground that a certain area or trench is to be photographed. Straight to the beginning of that trench line the pilot heads his machine. The observer compares the country over which he is flying with the chart or map which he carries. Just as a gunner sights a target, he locates the beginning of the trench line to be photographed through a bull's eye, and immediately pushes the button which sets the camera working. From that point the camera operates automatically, taking a series of overlapping pictures of the country it looks down upon. With calm determination the pilot holds his machine to the course laid out, in spite of any opposition that may arise in his path, for the slightest deviation from that fixed line of flight will mean a gap in the reconnaissance report which the pictures represent. But once he has covered the required area, he turns and flees. In less time than it takes to tell that magazine of films is being developed in a dark room. From there the printed pictures are rushed to an expert interpreter who reads the secret meanings of the things he sees--this or that dark blotch or peculiar looking speck suggests to his trained mind a machine gun nest, a railroad center, an observation post, a barbed wire entanglement, a camouflaged battery, an ammunition dump, or what-not. Pasted together so that they give a continuous view of the foe's territory, the printed pictures are hurried to headquarters, where in a few brief moments their message has been turned into a command to the troops. By the word that those pictures bring the battle is directed, and the blow is aimed straight at the enemy's vital spots. Occasionally instead of a series of photographs of a trench line or limited area, a continuous set of pictures of a broad space of country is desired. Then instead of a single machine as described above, a squadron of reconnaissance machines set forth, flying in V formation, with the leader of the squadron flying in front at the point of the V. The moment he reaches the area to be photographed, he notifies the machines behind him by firing a smoke rocket with a signal pistol. At that signal the V broadens instantly, so that it becomes almost a straight line, the commander keeping only slightly ahead so that he may lead the way. On and on that broad V formation of airplanes sweeps, every camera registering, and all keeping close enough together to produce slightly overlapping photographs. Each machine will bring home a long line of pictures of the country over which it passed, and those lines, pieced together, will make a large military map of the entire region. That is if everything goes smoothly, which in war time it seldom does. More likely that plucky V will be pounced upon by a herd of fast fighting machines whose duty it is to see that none ever return with their information to headquarters. There will follow a terrific contest; the observer in the reconnaissance machine becomes a gunner, and fires away at his pursuers, while the never-failing camera keeps steadily on with its job of recording. As nearly as possible the V formation is held, for much depends upon it, but suddenly a great gap appears in the line. "Done for" with a direct hit, one brave machine goes crashing earthward. That will mean a gap in the "map" that is in the making. Still the V presses on relentlessly. One of the planes begins to lag behind. There is something wrong with its engine. It does its best to keep up with its fellows, but soon it is left behind, and the enemy craft dive after it. Battered and torn, its numbers depleted sadly, several of its crew wounded, its wings perhaps riddled with bullets, the photographing squadron turns its face toward home, and, flying now as high as possible to keep out of sight, puts on all speed for the safe side of No Man's Land. Military photography _sounds_ easy and comfortable. It _demands_ the type of courage which can make a man stick to a given line of flight, even when certain death lies straight ahead. Sometimes a machine carries both bombs and a camera, and, as it drops its missiles, keeps a continuous record of its "hits" to carry home. And that brings us to the bombing machine, last but not least of the trio of military airplanes. The bomber that works by day and near to its own lines, is similar to the reconnaissance machine, except that it does not usually carry a radio apparatus or a camera. Instead, the greater part of its cargo consists of bombs, dread instruments of destruction which will fall on the railroad junctions, troop trains, staff headquarters or ammunition dumps of the enemy. The day bomber is never used for long distance work, and so it does not need to be of tremendous size, as the machine which must carry fuel for an all night run as well as a large quantity of bombs to drop on a far away important objective. The night bomber is the giant of the sky. The greatest genius of the cleverest designers has been expended upon its construction. More and more its tremendous importance is being recognized. Its activities precede every great offensive movement, for it flies over the enemy's country, leaving a trail of terrible destruction in its wake, and "preparing the soil" for the infantry advance. Deep in the territory of the foe it searches out the great supply centers and railway terminals and there it unloads its cargo of bombs. If the Allies had possessed a sufficient number of these huge bombing planes they could have carried on an aerial warfare against Germany which would have defeated her without nearly so great a sacrifice of the lives of the infantry. The work is dangerous, but a single bombing plane could have wreaked more vengeance upon the Hun than perhaps a whole regiment of the bravest fighters. Consequently its use would have meant economy of human lives. These fearful shadows that walk by night require pilots of the utmost skill to navigate the sea of darkness, as well as bomb droppers and gunners whose training has been perfect. The largest of them are equipped with either two or three powerful engines, each working a separate propeller. Such a machine can carry as much as five tons of explosives, with fuel for a twelve hours' flight. The night bomber is very often a huge triplane, for the extra wing surface gives greater lifting power. At the same time the triplane has greater stability and has a fair chance of reaching home even when one of its planes has been badly damaged. It is the same with a machine which has two or more engines: even when one of these has been put out of order by the shots of the enemy the airplane can still reach home. The night bombers must travel long distances, carry great cargos, bomb their objectives and make their escape, and so in the construction of their machines as much stability, lifting power and speed as possible has been the aim. Usually it is some important munition base or factory center that is supplying the German troops, which the airmen set out to bomb. They travel in squadrons not only for safety, but because in this way an almost unlimited number of bombs can be carried and dropped simultaneously. Often a second squadron follows the first at a short distance. By the light of the terrible fires that the first set of explosives dropped are bound to start, this second squadron can drop its bombs with greater precision directly on important buildings that must be destroyed. Moving slowly under their great load of explosives, and flying low, these two squadrons of destroyers start for some point in the heart of the German Empire. Like ghosts they "feel their way" mile after mile. They are not anxious to invite detection, for under the great weight of their "messages" to Germany, they would not be able to maneuver quickly or to climb to safety. Once those tons of explosives have been released and the noise of their dreadful havoc has aroused the anti-aircraft gunners of the enemy, those bombing planes will find the earth an uninviting sort of region and they will be glad to spring into the protecting silence and darkness of the upper air. And this they can do easily, for, rid of their load, they possess unusual climbing powers. The second squadron of bombers, flying over the same territory may expect a warm reception, and they will need to do their work quickly and beat a hasty retreat. Such are the mysterious doings of the night. When the early dawn appears, gray and heavy eyed, it will find the bombing planes tucked away drowsily in their hangars, scarcely knowing themselves whether the journey up the Rhine was a reality or merely a terrifying dream. And with the dawn their daylight sisters will take up the work near home. Word has just come that enemy reinforcements are moving up to the front along certain roads. "Fine," sings out a young lieutenant, appearing unexpectedly on the field from a small, carefully camouflaged office. "We will make them dance for us this morning!" He talks quickly and determinedly with a group of pilots, giving instructions, charging all to keep the formation. Machines are gone over to make sure that everything is in perfect condition. Then the first bombing plane, bearing the flight leader, "taxis" across the field, appearing to stagger under its great burden. Suddenly it takes to the air, and like a large graceful bird, its clumsiness all gone, it soars up into the blue. Rapidly the other big birds follow suit, and at a signal they are off, the flight commander heading the group, and the others following in close formation, like a huge flock of wild geese. On and on they fly, until beneath them appears the winding ribbon of road that is their objective. It is crowded with marching troops, gun wagons, supplies. As they swoop close to the earth they catch a swift glimpse of white faces turned up at them with terror. Then panic falls upon the marching column and, helter-skelter, every man tries to break away to a point of safety. In another moment guns are turned upon the bombers, but they dodge the flying shells and let go their heavy explosives, which crash to earth with dreadful uproar. Where a few moments before the Huns were following their way undisturbed there is now a road in which great furrows are plowed; huge holes gape open and a hopeless mass of débris covers the earth. The columns of the enemy will be blocked for many hours while the mass is being cleared away. Satisfied with the results of their exploit the bombing squadron turns swiftly toward home. How simple a matter it seems at first glance to release a bomb and hit a given point below. Actually it requires the very highest skill. To begin with, the airplane is moving at tremendous speed, and the bombardier (as the man who drops the bombs is called) has to know exactly how the forward motion of the airplane will affect the direction that the bomb takes on its course toward the earth. Moreover the bomb has a speed at starting equal to the speed of the airplane, and this beginning speed is increased by the action of gravity drawing it down. It may be aided in its journey by the wind or retarded, according to the wind's direction, and this too must be taken into account, if the target is to be hit. Bomb dropping can only be carried out successfully with the aid of the most delicate and complicated range-finding mechanism, with which every bombing plane is equipped. The Germans have led the way in inventions for this purpose, and their Goertz range finder is perhaps the best in the world. The bombs themselves are generally carried in vertical position, one-above another, in the body of the airplane, and by an automatic arrangement, as one is released, another slips into place, ready to be dropped. Now that we have made the acquaintance of the three types of machines that are used over the trenches--the "speed scout" or small fighting machine; the larger armed reconnaissance plane; and largest of all, the bomber--let us go back and give just a hasty glance at the main points of their construction. First we must recall the "A B C facts" we learned about wing construction. A wing gains lifting power from two sources: the upward pressure of the air current underneath it, and the force of the vacuum above it which is created by the arch of the wing. If a wing is only slightly arched it can move _forward_ through the air more swiftly, but it will not have the _lifting power_ of the high arched wing. This is the reason that an airplane which must be a weight carrier cannot be as fast in flight as the "speed scout," which has only its pilot and a machine gun to carry. The "speed scout" is always a small machine, usually a single-seater, with a gun in front that fires over or through the propeller. In the early part of the Great War it was most often a monoplane, but the smaller biplane took its place, because, with practically the same speed, it combines greater stability. The planes of the speed scout are very flat as compared with those of the reconnaissance craft. This airplane must carry machine guns, photography apparatus, radio, and a pilot, an observer, and often a gunner. Its wings must therefore be arched to give it lifting power, but at the same time it becomes a much slower flying machine than its smaller sister. Lifting power of a wing can of course be increased _up to a certain point_ by increasing the wing area, so that a greater air pressure is created below. Beyond that certain point the machine would become unwieldy and would lose its balancing properties. Yet this idea has been put into practise in building the latest types of aerial dreadnaughts used for reconnaissance. These airplanes have gained their lifting power partly by increasing the wing spread and partly by arching the wing. Thus a wing has been secured which offers the minimum resistance to forward motion through the air, together with the maximum weight carrying ability. Biplanes of this type are by far the most popular of those designed for general service, for they combine speed, climbing ability, and lifting power,--thanks to their strong armament they can defend themselves or run away quickly as the situation demands. But there is one other method which has not yet been mentioned of increasing the lifting power of an airplane. It is simply to add a third wing. When we have made the wings of the biplane as large as we dare, and have curved them to make them weight-bearers, if the resulting machine is still not strong enough to carry as many tons of explosives as we desire, there is only one thing left to do and that is to add a third wing. Thus the triplane made its appearance in answer to the call for planes which could carry vast cargoes of explosives and fuel for journeys of many hours over the enemy's country. The huge night bombing machine of the present time is almost always of the triplane type. CHAPTER V SOME OF THE PROBLEMS THE INVENTORS HAD TO SOLVE Every American must feel a glow of pride when he stops to think that it was two of his fellow-countrymen, Wilbur and Orville Wright, who invented the airplane. But it is largely to France, our great ally and friend, that the credit must go for improving upon the invention of the Wrights, and making possible the wonderful aerial feats, the marvelous flights and accomplishments of the airplane of to-day. From the first day they saw an airplane flown, the French were wildly enthusiastic. They gave freely of their money and their encouragement to help the good cause along. French inventors attacked the problems of the heavier-than-air machine with a will, and their unfailing determination and refusal to accept defeat or failure made final victory inevitable. But before we could have the powerful fighting machines, the big cross country fliers and the seaplanes of to-day, there were many difficulties of construction which had to be met and solved. First of all the pioneer designer had to choose between the monoplane, the biplane and the triplane. The monoplane was light in weight and could fly faster with the same powered engine than the biplane. But it was difficult to know just how to brace and strengthen the single pair of wings. In the biplane the struts between the wings gave strength and firmness. The wings of the monoplane were braced by wires to the body, but often they did not prove strong enough and the airplane collapsed in mid-air. In spite of this danger the monoplane was much in favor because of its speed. Slower in speed, but stronger and a better weight lifter was the biplane. And in addition to strength it possessed more natural stability, a much sought after quality in the pioneer days. Even more stable and with greater lifting powers than the biplane was the triplane, but the difficulty here was the lack of an airplane motor of sufficient strength to drive it. Until clever engineers came to the rescue with an improved aircraft motor, the triplane was very much in disfavor. The monoplane, indeed, captured most of the early records for speed and it was this type of machine that was generally built by the sportsman type of airman, while men like the Wright brothers and others whose aim was to develop an airplane of unusual reliability and suited to many purposes, turned to the biplane and gave many hours and months and years of their time to its improvement. Once the choice of a _type_ had been made, there were countless other problems. _Stability_ was of prime importance and the airmen of a few years ago labored desperately to attain it. They knew all too little about the airplane from a scientific angle. We have seen in our brief study that the method of obtaining balance in a glider or an airplane is to see that its _center of weight_ coincides with the center of the _upward pressure_ of air. How to bring this happy state of things about was a source of much debate. Some suggested that instead of a tail at the stern a tail in front of the main planes of the machine would help to balance it in flight. Some placed the pilot's seat above both planes of the biplane, while others thought he should sit below. Many of these queer ideas were tried out and by dint of hard practise and many failures certain simple elementary facts were finally weeded out and set down. Probably the addition of a "fuselage" or body to the modern airplane has had something to do with helping in the proper distribution of its weight and increasing its stability. Larger at the bow and tapering toward the stern where a fixed tail piece or horizontal stabilizing plane is attached, it resembled more or less closely the general outlines of a fish or bird. And this "streamline form" greatly reduces the _head resistance_, another important subject on which there was very little known when the first of the airplanes was built. In addition to having only a very slow and inefficient engine the early machine suffered from the head resistance it created as it pushed forward through the air, and this check to its progress ate up the little speed its motor could develop. For if the airman of 1908 or 1909 was made miserable by his fear of winds, gusts and aerial whirlpools which might upset him in mid-air, his fears in this direction were completely overshadowed by his worries about a suitable motor. If the design of his craft was faulty and it proved "balky" when he attempted flight, he had only himself to blame. But for an engine he had to rely entirely upon some one else. The airplane could be a "home-made" article, but the engine had to be chosen from such as were on the market. The Wright brothers in their first flying machine used a made-over automobile engine of 12 horsepower. It was not long before this was improved upon, and later Wright machines had a four-cylinder, water-cooled engine developing 35 horsepower. Its weight had been reduced as far as possible and its simplicity of design was its greatest recommendation. Undoubtedly the engine problem has been the big one in the history of aviation. The coming of the internal combustion engine might be said to have placed practical aviation within the range of possibility, but at that it took a long time to evolve a motor especially suited to the needs of aircraft. There were three things needed in an airplane motor: _Light weight_, _high power_, and _absolute reliability_. How important the third factor is we can imagine if we stop to think that nothing keeps the heavier-than-air machine afloat but its own speed, creating an air pressure beneath its wings. Like the boy who runs with his kite in order to make it go up, the airplane must "go" if it would rise, and the moment its engine fails there is nothing to prevent it from falling to the earth. The driver of a motor car, can, if his engine goes wrong, get out and go over it carefully until he finds what the difficulty is. The pilot of an airplane, soaring thousands of feet above the earth, is at the mercy of his motor's reliability or lack of it. Engine failure was, and still is, one of the greatest dangers the airman has to fear. Another chief cause of trouble in early airplane motors was overheating. Before actual airplane engines had been designed there was nothing to do but to use the type of engine which had been designed for the automobile, with as much reduction in weight as could be secured. But the automobile engine was never intended to run at top speed continuously and for long periods, as the airplane engine necessarily must do. In a car the motor has little stops and rests, as it is throttled down for a moment or changes in speed are made, and these breathing spells help it very much indeed in the "cooling off" process. The airplane engine does not have these little between-time naps. The result was that the automobile engine installed in the early airplane invariably overheated and caused serious trouble. Under these conditions no flights of any distance could possibly be attempted. Yet at the Rheims Meeting of 1909 Henry Farman surprised the world by remaining in the air two hours in a continuous flight. Up to that time the feat had never been equaled or approached. Aviators were amazed and sought an explanation. The answer was: the Gnome motor. Anxious to help the airplane in its forward march, French engineers had good naturedly set to work and the Gnome motor was their first answer to the anxious question of "What engine?" It involved a new and ingenious system of cooling which made it possible for Farman to drive his big machine round and round the Rheims course until stopped by darkness, but without ever experiencing the slightest difficulty with his motor. Before attempting to understand the secret of superiority of this first real airplane motor over others of its day, we must know a little more about the elementary principles of any internal combustion engine. The diagram on page 156 shows _one cylinder_ of such an engine in action. A mixture of gasoline and air--called "carbureted air"--is introduced through a valve opening into a chamber or cylinder, as shown in figure A of the diagram. The valve opening then closes, and the piston moves forward compressing the gases enclosed in the cylinder, as shown in figure B. An electric spark suddenly explodes these compressed gases, causing them to expand with the greatest violence and drive the piston back. This action, which is shown in figure C, is called the "power stroke," for, transmitted by the piston rod to the crankshaft it furnishes the power which turns the propeller and sends the airplane forward through the air. Just before the piston reaches the end of the power stroke the exhaust valve opens, and the exploded gases are forced out of the chamber, partly by the force of their own tension and partly by the upward stroke of the piston, as shown in figure D. The carbureted air is supplied to the cylinder from a chamber called the "carbureter." Here it is produced by the mixture of a gasoline spray--similar to the fine spray of an atomizer--with the air. [Illustration: DIAGRAM OF AN INTERNAL COMBUSTION ENGINE CYLINDER, SHOWING PRINCIPLE ON WHICH IT WORKS] A spark plug is fitted to the cylinder, and a break current from an electric magneto causes the spark which at the proper instant explodes the compressed gases. Since by means of the explosion of the gases the force is produced which drives the airplane propeller, the violence and frequency of these explosions determine the power of the engine. Greater power can be obtained either by increasing the size of the cylinder so that it can hold more of the carbureted air, making a greater explosion possible; or else by causing more frequent explosions. The latter is the better method in an airplane engine, as larger cylinders mean more weight to be carried. In the average airplane engine from 1500 to 2000 explosions or revolutions occur per minute. The combustion cylinder of an aircraft engine is usually built of steel, and the piston of cast iron or aluminum, which furnishes a very smooth gliding surface. The piston rod transmits the power to the crankshaft, a long rotating piece of steel. Every time the piston rod is thrust down by the explosion in the cylinder, its motion serves to turn the crankshaft and thus the vertical motion of the piston is transformed into the rotary motion which sends the propeller whirling through the air. Wherever two surfaces of metal must rub against each other, as in the case of the piston and the cylinder, there is bound to be a great amount of friction. This friction causes the parts to heat and in time it wears away the surfaces and destroys the efficiency of the engine. In order to avoid this, the surfaces must be kept constantly well oiled or "lubricated." In some engines all the parts are enclosed in one large box or "crank case" which is filled with oil. Small holes are bored through to the surfaces to be lubricated, and the oil is splashed upon them by the motions of the piston rod, the crankshaft, etc., as they plunge through the oil bath. But overheating of the cylinder may cause this oil to decompose and in order to prevent this a "cooling system" is necessary. For only when the engine is kept cool and properly oiled can it be expected to run smoothly or give satisfactory service. So now we come back to the problem of cooling, which caused so much anxiety and trouble to the early aviators. With their engines running at the great speed which was necessary to keep the airplane in the air, overheating and engine difficulties were sure to arise. Cooling of the cylinder is accomplished in one of two ways: either by water or by air. If water is used, a "jacket" in which the water circulates is placed around the cylinder,--the water as it becomes heated passing out of the jacket to the radiator, where it is cooled before it returns. The radiator, at the very front of the airplane body, is exposed to the swift current of the air as the machine drives forward, and this air current serves to reduce the temperature of the water. This method was the one originally employed with the automobile engine, but in the early models the cooling system, though adequate for the motor car, was hopelessly insufficient when the same engine was installed in an airplane. It was the Gnome manufacturers who first thought of a most ingenious scheme for cooling the cylinders of the internal combustion engine. Instead of having the piston and the crankshaft move, it was the cylinder itself which moved in the Gnome motor, while the crankshaft and piston were stationary. Thus cooling was very easily accomplished, for the cylinders, flying through the air, making as many as 1500 revolutions per minute, cooled themselves. The crankshaft in the Gnome motor had been hollowed out to form a tube or pipe, through which the fuel or carbureted air passed to the cylinder by means of a valve in the head of the piston which worked automatically. The Gnome could be built up of any number of cylinders, according to the power required. Its cylinders were set in a circle about the crankshaft, so that the entire engine occupied a minimum of space in the airplane body. Scouted at first as a freak engine, it soon proved its superiority over all those in use and was rapidly adopted by builders of all types of airplanes. To-day the stationary engine has been greatly improved, its provisions for cooling have been increased and it is once more looked on with favor by many manufacturers of aircraft. The cylinders of an internal combustion engine can be grouped in one of three ways, and thus there are three main types of airplane engines we should be able to recognize. They are the _straight-line_ engine, the _V-type_, and the _radial_. In the straight-line model four, six, or even a larger number of cylinders are placed in a row in one crank case. In the V-type of motor they are set instead in two lines, like a letter V; while in the radial type the cylinders form a circle around the central crankshaft. The radial motor may be stationary or its cylinders may revolve, in which case it becomes a rotary engine, as for instance, the Gnome. Each of these types of motors has its peculiar advantages. The least "head resistance" is caused by a straight line engine, and this type also uses less fuel and oil. But it is usually heavier in weight, owing to the larger cooling system necessary and the longer crankshaft, and it takes up more room in the airplane fuselage than a motor of the compact radial type. The radial engine is very light in weight,--a big item in the airplane--but it consumes a large quantity of fuel and oil and besides produces a maximum "head resistance." The V-type motor is a compromise between the two,--lighter in weight than the straight-line, less wasteful of fuel and causing less "head resistance" than the radial. The rotary engine, because of its appetite for fuel and oil is no longer used in airplanes which are intended for long distance flights, because here the weight of the extra fuel carried has to be considered. In short distance, high-speed machines it works well, but in the larger planes the vertical or V-type motor has been found to give greater satisfaction. When we read of the enormous trouble the pioneers of aviation went to, in order to find an engine suitable to drive the propeller of the airplane, we cannot help wondering just how the revolving of the propeller sends the whole machine flying forward through the air. The matter is very simply explained. The propeller of a ship is often referred to as the ship's "screw," and though few people have ever compared it with the small screws they use about the house, or with the screw and screw driver in the tool chest, there is in fact very little difference in principle. Take a screw and place it against a block of wood, and then commence to turn it with a screw driver. Straight into the wood its curved edges will cut their way, dragging the round steel rod of the screw behind them. With every turn they will cut in deeper and carry the screw forward through the wood. That is what the propeller of a ship or an airplane does: it screws its way through the water or the air. But of course there is this difference, that the wood offers great resistance to the forward motion of the screw, while the water offers much less resistance to the ship's propeller, and the air less still to the propeller of the airplane. If, as in the case of the screw-driver, the airplane propeller is in front of the airplane and drags its load along behind it, it is called a "tractor" propeller; but if instead it is placed at the stern of the airplane, and as it screws through the air it pushes the airplane along ahead of it, then it is known as a "pusher" propeller. The little cutting edge that winds round and round an ordinary screw is referred to as its _thread_, and the distance between two of these edges or threads is known as the _pitch_. In some screws the threads are very close or, to put it another way, the pitch is small, while in others it is much greater. Each blade of a propeller is really a portion of a screw. To go back to the example of the screw-driver and the block of wood, every time the screw is turned once around it will advance into the wood a distance equal to its pitch. The same thing is theoretically true of the propeller of an airplane; at each revolution it might be expected to advance through the air a distance equal to the pitch that has been given to its blades. But the air may allow the propeller to slip back and so lose some of its speed, a thing which was not possible with the screw-driver. This tendency to slip varies with the pitch of the propeller and the speed of its revolutions. A propeller which works splendidly when turning at a given rate, may prove worse than useless when the engine is slowed down and it is only making half the number of revolutions per minute. And so we begin to see another of the big problems of the pioneer airmen: to determine the right pitch for the propeller in relation to the speed which had been determined upon for the airplane. It is a problem that has not been wholly solved to-day, because of the fact that an airplane cannot always be driven at "top speed." If the maximum speed of the machine is 150 miles per hour, and the propeller has been designed to deal with the air efficiently at this speed, it is apt to slip and slide and waste away the power of the engine when for any reason it is necessary to slow down to 100 miles per hour. The only answer to the difficulty is a "variable pitch propeller" which may be altered to conform with alterations in speed, but up to the present time nothing really satisfactory along this line has been devised. Another question in connection with the propeller has been of what material to make it. Wood is most generally used to-day, for although steel and aluminum have been tried, they have not been found to stand the strain so well. Imagine for one moment the stress upon an airplane propeller beating through the air at the rate of 1500 revolutions per minute. The greatest strength has been secured by building it up of several pieces of wood which are fastened strongly together and varnished. _Materials_ have always presented a source of endless experiment and differences of opinion in the construction of the airplane. The problem has come up in connection with the fuselage, the wings and wing coverings, the landing chassis--in fact, each and every part of the heavier-than-air machine has raised the old query: "What shall we make it of?" In the earlier machines wood was almost entirely used in airplane construction. For one thing it was cheaper, and for another it was easier to get wood working machinery, than the complicated and expensive machinery necessary to construct airplanes out of metal. Metals are stronger but they cost more and they make the problem of repairs more difficult. The wings of the airplane are usually built up on a wooden framework which gives them their shape and curve. Many have been the disputes over the matter of wing coverings. In the pioneer machines they were covered with cotton material which had not been treated to make it water-proof or air-proof. It gave the poorest kind of service, and an effort was made to improve it by rubberizing it, but this process did not produce a wing of lasting durability. Many other treatments were experimented with, but with little success until the substance known as "dope" made its appearance. "Dope" is largely composed of acetyl cellulose. It makes the wing covering proof against rain, wind, and the oil thrown off from the airplane engine, and gives it a fine, smooth finish and excellent durability. Two or three coats of it are usually applied, with a final coat of varnish on top, to produce a wing that is sure to prove strong and trustworthy. The problems of starting and landing the airplane have been many. The early Wright machine had to run on a little trolley down a track in order to gain sufficient momentum to take to the air. Later machines showed an improvement on this. Henry Farman attached wooden skids to the bottom of his airplane and fastened wheels to them by means of heavy rubber bands. Thus he could start his motor and run over the ground until his speed permitted him to rise, while in making a descent the wheels flew back on their flexible bands and the stout skids absorbed the shock of the fall. Most of the modern machines have a wheeled framework below the fuselage, which permits them to run over the ground in starting and also in making a descent. The danger of engine failure becomes very important when near to the ground, as the pilot has no time to get his machine into a gradual glide and avoid a bad accident. This danger is sometimes averted by installing two engines, so that if one stops the other will carry the airplane on up into the air and prevent a smash-up. But the thing which has greatest effect on the ability of the airplane to land easily is its own design and speed. The wings of the airplane, its propeller and its whole construction have been planned so that it can support itself best in the air when flying at a certain fixed speed. Suppose this speed for a certain type of airplane to be 150 miles per hour. The airplane cannot land while traveling at that rate, yet its speed while still in the air can only be diminished to a certain point with safety, and below that point it may not be able to sustain itself in flight. The pilot must be able to land his machine without accident and without throttling his engine below this danger line; while the designer of airplanes must struggle to produce a machine which, while flying best at its maximum speed, will _fly_ at a much lower rate of motion, when necessary to effect a landing. The supporting power of the wings depends partly on their size and partly on their rate of motion. Small wings moving at high speed produce the same supporting pressure of air beneath them as large wings flying at slow speed. The problem of a safe landing could best be solved by building wings whose area could be altered in mid-air. When traveling under full power the pilot would reduce the wing spread, as the smaller wings would then be sufficient to support the weight of the machine and would create less air resistance. When about to land, he would increase the spread of the wings, so that at the slower rate of motion through the air he might take advantage of a larger supporting surface. Nothing of this sort has yet been worked out on a practical scale, but many have been the suggestions for "telescoping wings." The reduction of "head resistance" and the "streamlining" of the airplane have received their goodly share of attention and experiment. To-day the airplane fuselage is carefully streamlined, but the landing chassis beneath it creates a good deal of resistance to motion. Probably this problem will be solved by devising a landing chassis which, after the machine has arisen from the ground, can be drawn up inside the body, and let down again to make a landing, but this is another important question which is not yet worked out in the airplanes of the present time. The coming of the War caused all nations to stop and take strict account of what had been accomplished in solving the many problems of aviation, for the war machine had to be as nearly as possible the sum total of all the best that had been worked out up to that time in the difficult matter. In aircraft design and in types of engines France undoubtedly stood foremost, although the knowledge she possessed had not been sorted, pigeonholed and accurately standardized as was the case in Germany. Germany had some excellent aircraft motors of the water-cooled type, which were light in weight, very reliable and high-powered. The German government had spent large sums of money for the purpose of encouraging airplane construction and the improvement of designs and engines. Yet no country at war found her military airplanes all she had expected them to be. It was not until actual war service brought definite demands from the pilots and definite criticisms of the bad features of the airplanes in use, that the designers were able to turn out machines of the highest efficiency. There were many things which the pilots asked for. Speed and climbing power were among them, greater ease of operation, more protection in the way of guns and armament, the pilot's seat so located that his vision was not obstructed above or below, and a uniform system of controls. Gradually all these requirements have been met by the airplane makers. By 1917 they had turned out machines which could fly as fast as 150 miles per hour and climb to 22,000 feet, while since then even this record has been greatly improved upon. In the field of aviation America can claim one big accomplishment since her entrance into the World War. That is the Liberty motor, probably the most successful motor that has ever yet been devised for an airplane. When it was decided that we should begin work building American airplanes, there was one important problem: the engine. Foreign types of engines could not very well be built in this country, as they required workmen of many years' training in a highly specialized field. It was agreed that we must have a motor of our own, which could be manufactured rapidly under the conditions of our present industrial system. Two of the most capable engineers in the country were summoned to Washington, and in order to assist them in their work motor manufacturers from all over the United States sent draftsmen and consulting engineers. For five days these two men did not leave the rooms that had been engaged for them at the capital. Sacrifice was necessary if victory was to be won. Engineering companies and companies making motors for automobiles, etc., gave up their most carefully-guarded secrets in order to make the Liberty motor a success. The result was that an engine was produced so much better than anything on the market that our allies ordered it in large quantities for their own airplanes. Twenty-eight days after the drawings were started, the first motor was set up. It was ready on Independence Day, and was demonstrated in Washington. The parts had been manufactured in many factories, yet they were assembled without the slightest difficulty. The completed engine was sent to Washington by special train from the West. Thirty days later it had passed all tests and was officially the Liberty motor. One of the most remarkable things about the Liberty motor is the way in which all of its parts have been carefully standardized so that they can be manufactured according to instructions by factories in all parts of the United States. The parts can then be rapidly assembled at a central point. The cylinders are exactly the same in every case, although the Liberty motor is made in four models, ranging from 4 to 12 cylinders. They can be interchanged and the parts of a wrecked engine can be used to repair another engine. Thus American wit, patriotism and energy were able at a most critical time to answer the threat of German supremacy in the air. Our aircraft production has gone forward with speed which almost baffles understanding, while the airplane motors we shipped abroad in such overwhelming numbers to be installed in foreign machines gave good service to the cause for which the Liberty motor was named. CHAPTER VI FAMOUS ALLIED AIRPLANES Airplanes, like men, are not all alike, even when they are in the same line of work and performing the self-same duties. In war time, every gunner has his own little peculiarities, every sharpshooter has his personal ideas about catching the enemy napping, and every infantryman who goes over the top, in spite of his rigorous training in the art of war, meets and downs his opponent in a manner all his own. So it is with the machines that in the last few years have won fame for their valiant service over the dread region of battle. Roughly they can be lined up as fighting machines, reconnaissance airplanes and bombers. Yet if we look a little closer, individual types of planes will stand out of the general group, and it becomes fascinating to study them in their design, their achievements and their particular capabilities. [Illustration: _Copyright International Film Service, Inc._ THIS PHOTOGRAPH SHOWS THE RELATIVE SIZE OF THE GIANT CAPRONI BOMBING PLANE AND THE FRENCH BABY NIEUPORT, USED AS A SPEED SCOUT] As it would be impossible to mention in one short chapter all the brave pilots who distinguished themselves for their heroism in the war in the air, so it would be a hopeless task to attempt to do justice to all the airplanes which rendered good service over the front lines. The best we can hope to do is to make the acquaintance of the most famous of them all. [Illustration: _Copyright International Film Service, Inc._ THE SPAD, THE PRIDE OF THE FRENCH AIR FLEET] There is one little machine, which, when the final retreat was sounded and accomplishments were reckoned, had covered itself with glory. Like the many famous pilots who have driven it, it has learned much by experience, and it has changed considerably in outward appearance since the summer of 1914. Wherever the achievements of the "speed scout" are mentioned the _Nieuport_ is bound to come in for its share of the praise. This little fighting machine was greatly relied on by the French, who used it in large numbers over the front lines. Although lately another swift scout plane has come into the field to eclipse its reputation, it probably took part in more aerial battles than any other airplane of the Great War. It was the _Nieuport_ monoplane whose speed and agility at maneuvers made it a favorite in the early days of the hostilities. For a while it was a match for the German scout machines, but the rapid strides which aviation took under the pressure of war necessity left it behind, and the more rapid and efficient _Nieuport Biplane Scout_ made its appearance. In several important features it was entirely different from any of the biplanes. It could not quite forget its monoplane construction, and it had made a compromise with the biplane by adding a very narrow lower wing. It was humorously nicknamed the "one and one-half plane," but it proved itself just the thing the fighting airmen were looking for. Its narrow lower plane, while giving more stability and a "girder formation" to its wing bracing, did not interfere with the pilot's range of vision, a highly important consideration. In order to allow as full a view as possible in all directions, it had only two V-shaped struts between the planes, while the upper wing, just above the pilot's seat, had been cut away in a semi-circle at the rear so that he might be able to see above. The lower wing was in two sections, one at each side of the fuselage. This little biplane had a top wing span of only 23 feet, 6 inches, while the distance across the lower plane from tip to tip was a trifle shorter, measuring just 23 feet. The upper plane measured from the front to the rear edge a trifle less than 4 feet,--or to use technical language, it had a "chord" of 3 feet, 11 inches; while the chord of the lower wing was only a little over 2 feet. The entire length of the biplane from the tip of its nose to its tail was 18 feet, 6 inches. The fuselage was built with sides and bottom flat but the top rounded off. There was plenty of room for the pilot to move freely in his seat. Armed with a machine gun which fired over the propeller, he was well able to defend himself when enemy craft appeared. The _Nieuport_ biplane wrote its achievements in large letters during the Great War. It was the machine which Guynemer and his famous band of "Storks" flew in their daring battles against the German fast scout, the _Fokker_. It carried many an American chap to fame in the Lafayette Escadrille. England, Italy and America all used it over the lines, and its high speed and quickness at maneuver made it a general favorite. To-day it is made in either the single-seater scout type, or in a larger, two-seated model. The gunner's seat in the latter is in front of the pilot, and a circular opening has been cut in the upper plane above him, so that in an aerial battle he may stand up, his head and shoulders above the top wing, and operate the machine gun, which fires across the propeller. In spite of all its excellent qualities and its record of victories won, the _Nieuport_ has lost its championship among the "Speed scouts." Another tiny biplane of still greater speed, has wrested the honors from it. The first place among fighters is now perhaps held by the _Spad_. Carrying one or two passengers and equipped with an engine of 150 to 250 horsepower, with its Lewis and Vickers machine guns spitting away at the enemy, it is a formidable object in the arena of war. Not to be left behind, America has developed a small, fast fighting machine which bids fair to make the other two look to their laurels. It is a tiny _Curtiss triplane_, the span of whose wings is only 25 feet. Its extra lifting surface gives it remarkable climbing powers without increasing its size as a target. It is always an advantage to a fighting machine to have as small a wing area as possible, for, besides being able to maneuver more quickly, it furnishes a smaller target to the enemy's gunners. The triplane can mount rapidly into the upper air, so as to command a strategic position above the airplanes of the foe, while to those attempting to fire upon it from above or below, its three wings do not present any larger surface than the two of the biplane or the one of the monoplane. The Curtiss factory has been at work for several years on the problem of the small fast fighter. Its first effort was a biplane whose top wing span was only 20 feet. In a test flight by Victor Carlstrom at Sheepshead Bay Speedway, New York City, its unusual performances amazed the spectators. With startling swiftness the pilot mounted into the blue, maneuvered his little biplane with the agility of an acrobat, gave excellent tests of speed, and descended. Reducing the speed of his motor but not cutting it off entirely, he allowed the little airplane to skim slowly along the ground. Then, alighting, he took hold of the fuselage close to the tail, and steered the diminutive craft to a suitable spot from which to make another flight. With the motor still running, and much to the surprise of the onlookers, he stepped in once more, put on full power and was off. This little airplane was nicknamed the _Curtiss Baby Speed Scout_. In one interesting respect it was different from the _Nieuport_, whose upper plane had to be cut away to increase the pilot's range of vision. In the Curtiss machine the pilot sits just behind the planes, so that he can see above and on all sides with the greatest ease. As a protection in battle his seat and the front portion of the fuselage are surrounded with thin steel, and the pilot sits close to the floor, so that he does not offer a very good target to the enemy's stray bullets. The "baby" biplane is fitted with a standard V-type motor of about 100 horsepower, and it carries fuel for a run of two and one-half hours. The British have done some very fine work in developing airplanes of the speed scout type. Their fighting machines flew over the lines and downed the German planes in goodly numbers. Among those which earned fame for their achievements are the _Bristol Scout_, familiarly known as the "bullet," one of the fastest of the military airplanes; and the _Vickers Scout_, another of the swift eagles that helped to maintain Allied supremacy in the clouds. One of the interesting features of the Vickers scout is the high "stagger" of its planes. By this we mean that the upper plane has been set far forward, so that it appears to overhang the lower. Quite recently another British scout machine, a _Sopwith triplane_, was flown by the British Royal Flying Corps, and it made a splendid record of victories over the lines. In a crack regiment of veteran fighters it is hard to pick out the men who might be said to be the "best soldiers." Each man excels in some individual way, and in just the right situation might prove to be the leader of his fellows. So it is bound to be with the long list of valiant little fighting planes that took up the cudgels against the Hun. No short summary can do justice to them all. There are the _Avro_, for instance, and the _De Havilland Scout Biplane_ of the British, as well as a biplane of the _Sopwith_ type; while the list is almost endless of British and French machines bearing such well known names as _Farman_, _Caudron_, _Dorand_, _Moineau_, _Morane-Saulnier_, etc. But whatever the particular features of these scout machines, their armament is generally about the same. It usually consists of a machine gun operated by the pilot and firing across the propeller. The pilot directs the nose of his machine straight at the enemy and lets go a rain of bullets. Fighting tactics are the subject of the most intense study on the part of every pilot of a scout machine. Often he has his pet system of downing the enemy. Immelmann, the famous German aviator, liked to get high in the upper air and there await the approach of a "victim," when he could dive straight down upon the unsuspecting airplane and open fire. Every pilot aims to surprise his enemy. To do so he must often perform startling aerial tricks, looping the loop to come up under the tail of the other machine, swooping down from above, or firing from behind while the tail of the enemy machine shields him as he gets in his fatal shot. The aviator learns to hide behind a cloud, to take advantage of blinding sunlight or any other natural condition in order to take the opposing airplane unawares. It is for this reason that machines are needed which combine speed, exceptional climbing powers, and quick maneuvering ability. Not only must they be able to practise all manner of tricks and stunts in order to surprise the foe, but it is quite as important that they be able to move rapidly on their own account, for a slow moving airplane is more liable to surprise than one which is swift in flight and able to alter its course repeatedly or else climb out of danger's way. How important the agility of these little fighting planes is they are apt themselves to discover when one of their number meets a big reconnaissance machine of the enemy. The latter, with its big guns, is a formidable object, and could easily get the better of the lightly built combat plane, if it were not for the fact that its weight and slow speed make it unmanageable. The smaller machine drops down upon the big fellow suddenly, firing a volley at its gunners. If he kills them well and good, but if not he must perform his cleverest aerial stunts to get out of their way, or he will soon be a mere ball of fire shooting earthward. Fortunately, he is quick, and a few acrobatic turns save him from threatening disaster. Before the present type of reconnaissance craft, bristling with machine guns had been developed, it was customary for the airplane doing photographic work, artillery "spotting" and similar duties to rely for its protection on a number of speed scouts, who flew above and around it and escorted it upon its mission. To-day the airplane that is used for general service duties over the lines is a dreadnaught of the air, and although it may still take along with it on its errands a few scouts to give battle to the faster airplanes of the enemy, yet on the whole it is self-reliant and has little to fear. To these slower-flying, larger general service machines are entrusted some of the gravest duties of war. They are the eyes of the army, whether they act for the heads of staff, flying out over the territory of the foe with their trained observers and bringing back accurate information about the movements of troops, whether they help in "spotting" targets for the gunners, or whether during an actual engagement they act as aerial spectators and messengers, helping to coordinate the efforts of the various bodies of troops. From the beginning of hostilities Germany strove to overwhelm the French in the air and prevent their airplanes from performing these necessary duties. France was at first but poorly equipped with machines of the type so sorely needed to maintain her air supremacy. By the skill and bravery of her airmen she managed to hold out, however, and the Huns were disappointed in never accomplishing their purpose of putting out her eyes. Her engineers were in the long run much more clever than those of Germany, and by the early part of 1915 they had ready a number of superior machines for reconnaissance and bombing. For the most part they were big _Caudrons_ and _Farmans_, well armed and a good match for the German maid-of-all-work biplanes. And there were large _Voisin_ biplanes, suitable for photographic work or for bombing. They were used extensively by French, British, Belgians and Italians. The _Voisin_, as in its very earliest models, is still easily recognizable by its curious tail resembling a box-kite, placed at the end of a projecting framework of four long beams or outriggers. It is a pusher type of airplane, with its propeller at the stern instead of at the bow. Larger and more formidable grow the "aerial destroyers." To-day among the super-dreadnaughts of the sky may be numbered the big biplanes bearing the names of _Moineau_, _Breguet-Michelin_, _Voisin-Peugeot_, and _Farman_. Heavily armed with machine guns they rendered valuable service to the Allies in many capacities, and they were the efficient answer to the struggle of the Hun for aerial supremacy. When in the Spring of 1918 the Germans launched their tremendous offensive at the Allies, the latter were well informed in advance of their intentions, thanks to these powerful reconnaissance planes. Swooping down close to the German lines in defiance of anti-aircraft guns and fighting machines alike, they had daily looked on at the massing of troops, the bringing up of reenforcements for the drive, and the piling up of ammunition supplies. In spite of every effort of the enemy to make their mission an intolerable one and to prevent them from spying upon preparations for the offensive, they had succeeded in bringing back to Allied commanders accurate and detailed information. By their aid the Allies knew at what points to expect the heaviest blows, and there they collected their reenforcements. Thus the nations lined up against the Hun were ready when the blow came, and they were able to check the tremendous onslaught by their land and air forces. What they really lacked perhaps, was not "eyes," to discover what the Germans were plotting, but a large enough number of small fighting machines to keep the enemy reconnaissance craft from spying upon their own preparations; and a large enough number of huge bombing planes to have completely interfered with the German efforts to mass reenforcements and ammunition for the push. In the long run it is perhaps the bombing plane that represents the greatest saving in human life in time of war. An army may be well equipped with reconnaissance machines and speed scouts, so that it may keep in closest touch with every move of the enemy. But unless it is able to interfere with those moves _before_ they reach the proportions of a direct and staggering blow, then the best it can do is to concentrate its own troops and supplies in readiness to meet the blow when it does fall. That means that hundreds of thousands of lives of infantrymen will be sacrificed in checking the waves of enemy troops. The Allies discovered a far better and more economical way of winning the war than this, and in the last year of the War they strained every nerve to put it into actual operation. It was this: to search out every military base of the enemy, every munition dump, nest of guns, supply train or troop train and drop bombs upon it. Two men in a bombing machine can attack and perhaps destroy a force which, if allowed to reach the front lines, would have to be met by several thousand infantrymen. Two men in a bombing machine can destroy at a single blow the ammunition which, if it had reached the front, might have swept out a regiment. That is why so much thought and genius has been expended upon the bombing plane. The day bomber becomes the right arm of the infantry, flying low over the lines, attacking troops and striking terror to the heart of the enemy as the huge Allied tanks did when they first started on their irresistible slow walk across trenches, troops, buildings and every manner of obstruction. The big bomber--particularly if the fighting machines have cleared the way ahead of it--is something like that: it is an invincible weapon of destruction, wiping out whole bodies of the foe at every stroke, like a giant sweeping the pigmies of earth ahead of him with his strong right arm. The big dreadnaughts of the air like the _Moineau_, the _Voisin-Peugeot_, the _Breguet_, and the _Farman_, become, when a bombing apparatus is substituted for their camera and radio, very efficient day bombers. There is a long list of others: as for instance, the British _Avro_, _Handley-Page_ and _Sopwith_ machines and the French _Caudron_, _Dorand_ and _Letord_. Many of these big bombing planes were designed for long distance work either by day or by night, and so they have been made enormous weight-lifters, with large supporting surfaces, two or more engines, and equipped with a fuel supply sufficient for long runs. In order to carry their engines conveniently they very often have more than one fuselage. Sometimes the pilot sits in a large fuselage in the center, while the motors are carried in two smaller cars or bodies called "nacelles" at either side. The British _Avro_, for instance, is a huge biplane with three fuselages and two rotary engines. Its upper and lower wings are equal in span, and it can readily be distinguished from the British _Handley-Page_, whose upper wing has a large overhang. The _Handley-Page_ is one of the largest machines built. It carries its two 12-cylinder Rolls-Royce engines in small nacelles between the main planes, and it can be recognized by these and its biplane tail. The _Caudron_ is another big twin-motored machine, used by French, British and Italians. Its two rotary engines are fixed in small nacelles between the planes, while the pilot rides in a center fuselage. Somewhat after the manner of the Voisin, it carries its tail at the end of a projecting framework of four long beams, the lower two of which act also as landing skids. [Illustration: _Copyright International Film Service, Inc._ A HANDLEY PAGE MACHINE TUNING UP FOR A FLIGHT] America, like the rest of the nations, has had her secret ambition to try her hand at building bombing machines. In 1918 the designs for the _Handley-Page_ bomber were brought to this country, and on July 6th the first American built _Handley-Page_ bomber was successfully launched into the air at Elizabeth, New Jersey. The huge machine was christened the _Langley_ after one of the early experimenters with the heavier-than-air machine. It had a wing span of 100 feet, and a central fuselage 63 feet long. Small armored nacelles at either side of the fuselage carried its two 400 horsepower Liberty motors, each turning a separate propeller. Laden with its full supply of bombs, its two Browning machine guns and fuel for a long run, this giant of the skies weighs about 9,000 pounds. Our country has instituted a program of construction for these super-dreadnaughts, and before long they will form an enormous aerial weapon in the hands of our airmen. For America, still practically a novice at airplane construction on a large scale, to be able to produce in her factories the largest and most complicated of the foreign types, speaks well for her determination and resourcefulness. [Illustration: _Copyright Underwood and Underwood_ THE LAUNCHING OF A LANGLEY, A GIANT BOMBING AIRPLANE] The Allied nations have vied with each other in their efforts to produce the king among bombing planes. The Italians have undoubtedly carried away the prize. Their _Caproni_ triplane is among the largest in the world. The details of its construction were kept secret, as it was one of the most dreaded weapons of the Allies. Three powerful Fiat motors drive it at a speed of about 80 miles an hour. With its five tons of bombs, destined for important objectives in the land of the enemy, it is an object to inspire awe. The _Caproni_ makers have long been known for their large bombing machines. Their three bombers, including a smaller triplane and a biplane, headed the list of their fellows at the front. In October, 1917 a _Caproni_ biplane was demonstrated in America, covering a distance of almost 400 miles in about 4-1/2 hours. It started its journey from Norfolk and landed at the Mineola Aviation field, with seven passengers on board. _Caproni_ bombing airplanes carried out many historic raids, among them being that on the famous Austrian Base at Pola. To reach it the Italian aviators had to travel by night across the Adriatic, and they carried out their pre-arranged plan of attack with the utmost punctuality, in spite of the tremendous difficulties that loomed along their path. Two squadrons of machines left the aerodrome, the first some time before the second, and each airplane following its fellows at a considerable distance. At 11 o'clock at night the first of the bombers flew over Pola and discharged its rain of high explosives. In rapid succession the others followed, letting go their missiles upon stores of ammunition, docks, and every object of military importance. In order to aid them in picking out their targets the raiders made use of an ingenious contrivance which so amazed and stupefied the Austrians that for a while they failed to make any attempt to shoot down the Italian planes with their anti-aircraft guns. It was a huge parachute, to which had been attached a powerful chemical light. Descending slowly the terrifying object hung as it seemed suspended in mid-air, lighting the way for the raiding machines, who took advantage of the terror of the Austrians to drop 14 tons of high-explosives and make their escape unharmed. The tremendous _Caproni_ triplane is almost impregnable. Its enemies have little chance of downing it, for it can fly even when one of its planes has been severely damaged, and with its three powerful motors it is practically immune from any engine trouble, as in case of an accident or injury to one motor the other two, or for that matter, one of them, will carry it safely home. With the great stability given it by its three supporting surfaces it can go through the stormiest weather without the slightest need for fear. Once its load of bombs has been discharged, it can rise to 7,000 feet to escape from its pursuers. The story is told of an Italian aviator, Major Salomone, who escaped in a _Caproni_ when attacked after a bombing expedition by a squadron of Austrian speed scouts. His enemies succeeded in wrecking one of the big engines by their gun fire, and in killing two of his gunners and a pilot. He himself was severely wounded, but keeping control of his machine he managed to reach home safely by the power of the remaining two engines. The triplane is by far the best type for these giant raiders that fly by night. Their requirements are great lifting power and great stability, and these, the triplane with its extra lifting surface, best fulfills. Equipped with two or three engines so that its power-plant can be absolutely relied upon in every emergency, with accurate bomb-sighting instruments and with a compass, searchlight and other apparatus necessary for traveling by night, the triplane can be depended upon to inflict gigantic blows upon enemy bases. The British have a big bombing triplane that was heard from in Germany: the _Sopwith_. Its three planes are equal in span, and have only one strut at each side of the fuselage, with the wiring also greatly simplified, in order to reduce the head-resistance to a minimum. [Illustration: _SIDE VIEW OF A SOPWITH TRIPLANE_] [Illustration: _TOP VIEW OF THE "TAIL" OF THE SOPWITH_] The _Sopwith_ was one of the first triplanes to be used for bombing and general service over the lines. Those at the front early in 1918 were equipped with a 110 horsepower Clerget rotary engine. A round metal hood or "cowl" surrounding the motor formed the front of the fuselage, overhanging the body slightly at the bottom in order to form an air outlet for the engine. America has not actually developed any big bombing planes of the type of the _Sopwith_, although we have one enormous triplane,--the _Curtiss_ triplane air-cruiser, built for service over the sea. And although Russia abandoned the good cause for which she was fighting, we cannot pass over the subject of big bombing triplanes without mentioning the giant _Sikorsky_, one of the largest and most remarkable weapons of destruction that were employed in the war against the Hun. The future will no doubt write a new and fascinating chapter in the story of the triplane. The big night bombers are being built on a large scale by all the Allied nations. Their exploits opened every great military operation, they constituted a reign of terror over the lines of the enemy, and their death-dealing blows saved countless thousands of allied troops from the need of sacrificing their lives. They could make the journey straight to the heart of the enemy's country and return, with plenty of surplus fuel. Their missiles did enormous damage to railway centers, docks, bridges, aerodromes and arsenals. Carrying bombs that weigh anywhere from 16 to 500 pounds, they spread havoc in their wake, while the silencers on their engines made them veritable specters of the night. An illustration of their possible accomplishments was the flight of Italian machines across the Alps and to Vienna, when they dropped manifestos upon the frightened populace. Those manifestos reminded the Austrian people that only the humanity and self-respect of the allied airmen made them drop "paper bombs" on Vienna while the Germans were unloading high explosives in the midst of the civilian populations of London and Paris. It must have shown the people of Vienna what the machines of their enemies were capable of doing. [Illustration: _Copyright Underwood and Underwood_ AN AMERICAN BUILT CAPRONI AIRPLANE] But the airplanes of war whose acquaintance we have made so hastily in this chapter were not used by the Allies for raiding or terrifying civilians. From the tiny fighting machines that carried so many of our bravest pilots to personal combat over the lines, to the enormous bombing planes used to scatter destruction and ruin among the military strongholds of the enemy, our machines were trustworthy and brave, but they were also machines of honor. [Illustration: _Copyright Underwood and Underwood_ THIS CURTISS TRIPLANE HAS A SPEED OF ONE HUNDRED AND SIXTY MILES AN HOUR] CHAPTER VII GERMAN AIRPLANES IN THE WORLD WAR When we read the story of the wonderful contributions made by France, England, Italy, and America to the progress of aviation and to the romantic history of the heavier-than-air machine, we must remember that it is the story of nations which, a few short years ago, had no thought of turning the airplane into a mere weapon of destruction and desolation. It was the conquest of the air, for its own sake, that appealed to the fiery imaginations of the French, and that made them, from the day when the first Montgolfier balloon went soaring into the clouds, down to the early triumphs of the airplane in France and the great contests and meetings that followed them, ardent enthusiasts over each and every form of aerial sport. England, in spite of the fact that her sportsmen fliers were winning new triumphs daily, and in spite of the public interest that was taken from the very beginning in the advance of aviation, had, at the beginning of 1911, just _one_ military airplane. America, ardent devotee of Peace, even while the World War was raging in Europe, failed to take steps to provide herself with an aerial fleet. But when we come to Germany, the story of aviation takes an entirely different turn. The Germans as a people were never wildly enthusiastic over airplanes, for they lacked the fine sportsmanship and love of daring adventure which produced so many clever aviators in other lands. In fact, until they saw its utter inability to compete with the heavier-than-air machine as a military weapon, they confined themselves almost entirely to the construction of the safe and comfortable dirigible. With the possible exception of such a man as Lilienthal, the Germans took slight personal interest in the subject of human flight. It was the German government that, by lavish expenditure, and by every means known to it, encouraged experiment and progress. The whole thought in Germany, both in the days of the dirigible and later, when the airplane had proved its superiority, was solely to develop the flying machine as an instrument of war. It was for this that she began her costly and gigantic program of Zeppelin construction, it was for this that the best engineers in the Empire were set to work designing aeronautic engines. It was not without some chagrin that the German military authorities gave up their dream of world conquest by means of the Zeppelin, and set themselves to building airplanes instead. Yet when they did, they applied to the new problem the same thoroughness, the same military precision and uniformity that had marked their earlier program. Reading of the French machines we are fascinated by the many types and patterns that the ingenious Frenchmen were able to devise. In Germany everything was carefully systematized by the government, individual designs were discouraged unless they fitted into the military scheme of things, and the airplane was produced in large numbers, like so many blackjacks, all exactly alike, to be used in striking the peaceful nations of the world. German thoroughness went a long way in perfecting the airplane as a war instrument. When, in August 1914, her sword finally descended, she had close on to 800 machines and a thousand trained pilots, together with a small force of seaplanes and pilots. To-day, according to an English authority, she has at least 20,000 aircraft of all sorts, manned by a force of 300,000 pilots, observers, and bombardiers. The first German machines to fly over French territory might well have struck terror to the hearts of the plucky French, for they were equipped with the cleverest instruments of destruction that Germany could devise. The swept-back, curved wings of these standard biplanes won them the name of _Taube_ or "dove." Certainly they were not "doves of peace." They were equipped with wireless, carried cameras for reconnaissance work, had the most accurate recorders of height and speed, dependable compasses, instruments for bomb-dropping, dual control systems, so that they could be operated by either pilot or observer, and dozens of other small improvements and accessories that made them more than a match for the French machines sent up to dispute their supremacy in the air. The challenge these machines presented to the genius of the French was taken up with vigor. It was not long before they found themselves an obsolete form of aircraft in the great war in the air, and for all their inventions and improvements, they were forced back into their hangars. By the Spring of 1915, the French were soaring through the sky in fast fighting machines that made the air a very unsafe place for the plodding German "maid-of-all-work." The Germans bestirred themselves to think of some method of getting even with these unreasonable French pilots, who somehow refused to admit defeat. The machine which they sent out in answer to the _Nieuport_ monoplane and others of its type was the invention of a Dutchman; it succeeded in creating quite a sensation for a while in Allied circles, until like others of its company it was superseded by French inventive genius and rendered a more or less harmless craft. This supposedly invincible fighter was the _Fokker_. In general construction it was largely an imitation of the French Morane monoplane, but it had one entirely new feature that rendered it at the time a formidable adversary. That was what was known as a synchronized gun, firing through the propeller. The problem had been to design a machine which could be operated by one man, who became both the pilot and the gunner. In order to do this he must necessarily be able to control the direction of his machine in flight and aim his gun at the enemy at the same time. The best way to accomplish this was to point the nose of his machine at his victim and fire straight ahead of him. But here the propeller was the great obstacle. How could he fire a gun from the bow of his machine without striking the propeller blades as they whirled swiftly about in front of him? The German _Fokker_ answered that question. The machine gun with which it was equipped had its shots so synchronized, or "timed," that, impossible as it seems, they passed between the rapidly revolving propeller blades without striking them. The _Fokker_ was a remarkable climber in its day, and in addition it had a simple device by which the pilot could lock the control of the elevating planes, steering only to right or to left, by means of pedals worked with his feet. Early in 1916 this deadly weapon of aerial warfare made its appearance, and for a while the civilian population of England and France read with dismay of its conquests. Mounting high into the clouds, it would await its victim. The moment a machine of the Allies appeared beneath it, the _Fokker_ turned its nose straight down and went speeding in the direction of its prey, opening fire as soon as it got within range. There was no use of the unfortunate airplane trying to escape. The _Fokker_ could, by wobbling its nose slightly in spiral fashion as it descended, produce, not a straight stream of bullets ahead of it but a cone of fire from its machine gun, with the victim in the center of the circle. Whichever way the latter turned to escape it met a curtain of bullets which could destroy it. The Allied machines could only combat it in groups of three and for a time at least it held supremacy in the skies. When itself pursued by a superior number of planes, it was quick as an acrobat, and speedy at climbing, so that it very seldom could be caught. This was the machine in which the two famous German airmen, Immelmann and Boelke performed some of their most daring exploits. It traveled at a speed of more than 100 miles per hour and could perform surprising feats with the most alarming ease. But while the _Fokker's_ début over the trenches caused the British House of Commons to debate the new peril gravely, French and British airmen sprang quickly and gaily to the challenge. Heedless of the danger, they braved the bullets of the _Fokker_ in order to get a better view of its mechanism, and they soon answered it with swift and powerful machines like the British _De Havilland_. It was only a short while before the Fokker monoplane was "behind the times." Faster machines with greater climbing powers overtook it in the skies and swooped down upon it from superior altitudes, as it had swooped down upon so many of its victims. Its day of triumph at an end, it withdrew to the seclusion of its hangar, and the _Fokker biplane_ replaced it in the air. This in its turn became the steed of many of Germany's star aerial performers. Now came the days when Captain Baron von Richthofen held forth in the heavens with his squadrons of variegated planes which the British airmen nicknamed "Richthofen's circus." These queerly "camouflaged" planes were German Albatroses. The _Albatros_ was one of the best designed of the German airplanes, and although the first models produced were not remarkable for their speed, they were good climbers and weight-carriers and thoroughly reliable. They were later developed in two distinct types: a fast "speed scout" biplane single-seater, equipped with two machine guns both firing across the propeller; and a slower reconnaissance airplane, for general service over the lines. The latter carried both a pilot and an observer, and had two machine guns, one to be fired by each of them. It was not long before the Allies had several captured machines of this type in their possession. An Austrian _Albatros_ reconnaissance biplane, taken in 1916, afforded an interesting opportunity to examine what was at that time one of the very best of the enemy's planes. Its general construction did not entirely meet with the approval of expert airmen who looked it over. Its upper wing was much longer from tip to tip than the lower, producing a very great overhang. From the point of view of the pilot this had its advantage, for the shorter plane below him allowed a much better range of vision, but it undoubtedly weakened the whole structure. The biplane was exceedingly slow in flight, a great drawback even in a machine not built for fighting purposes. One curious feature was its very large fixed tail plane, to which the elevating plane was attached; while a decided defect from a military standpoint was the entirely unprotected position of the pilot and the observer. Obviously the Germans had not yet solved the problem of air supremacy to their complete satisfaction. But their engineers and designers were busy thinking it over, and soon they had ready a number of swifter airplanes, foremost among which were probably the _Aviatik_ and the _Halberstadt_. The _Aviatik_ made great claims of superior accomplishments over the front lines. German pilots boasted that it had a "ceiling" (a climbing capacity) of almost 16,000 feet with pilot, observer and a fuel supply. This was over 4,000 feet greater altitude than that which any other Allied or enemy machine could reach under similar conditions. The machine had an upper wing span of 40 feet, 8 inches, while its lower wing measured 35 feet, 5 inches from tip to tip. It had a strong armor of steel tubing surrounding the compartment or "cockpit" which held the seats of the pilot and observer. The _Aviatik_ was an efficient bombing biplane of its day, although larger and more powerful machines have since come into the field to supersede it. It was fitted with metal bomb-launching tubes at either side of the bow, and the bombs were released by pulling a cable connected with the releasing trigger. The _Aviatik_ was armed in addition with rotating machine guns, able to fire in any direction in an aerial battle. The _Halberstadt_ was a swift fighting machine or speed scout, which made its appearance in the third year of the war and proved efficient and reliable. This and the combat planes that followed it showed greater and greater speed until by 1917 the scout machines were flying at 150 miles per hour and climbing to altitudes as high as 22,000 feet. It was the bombing plane, however, that appealed most strongly to the German mind as an instrument of destruction. Tired, perhaps, of their efforts to produce a fighting machine which should be without its match in aerial warfare, they focussed their attention about this time upon the bomber, which in 1917 was playing an ever more important role in the struggle for air supremacy. Early in 1917, the flower of their creative genius took to the air. It was the _Gotha_ biplane, and at the time of its début it proved one of the most difficult machines to attack and down of any of those flying for the Hun. The _Gun-tunnel Gotha_ it was familiarly called, owing to the unusual means of defense against pursuers that had been devised for it. Up to this time one of the best methods of attacking an enemy plane had been to come up suddenly and fire on it "under its tail." The gunner in the machine thus attacked could not get in a single shot at his pursuer without striking the tail planes of his own machine. The portion of an airplane which can be fired on in this way without danger of return fire is said to be its "blind spot," and it was this blind spot that sent many a well-armed and powerful airplane crashing to earth when its pursuers had succeeded in outmaneuvering it. The _Gun-tunnel Gotha_ had practically no blind spot. Its designers had constructed it with a tunnel that ran the length of the fuselage, from the cockpit, or compartment where the pilot and gunners sat, through to an opening just under the tail planes. A machine gun in the cockpit could be pointed through this tunnel and fired at the unsuspecting victim who came up back of it according to the most approved tactics. The opening of the gun tunnel was carefully "camouflaged," so that at a short distance it could not be seen by an attacking airplane, especially one which was unprepared for it. The _Gotha_ practically bristled with machine guns. One in its bow which commanded a fairly large range was operated by the forward observer, who sat in front of the pilot. A passage-way beside the pilot's seat allowed him to reach "gun-tunnel," where, stretched flat on the floor of the fuselage he operated the gun which fired out under the tail. Above him in the fuselage sat the rear gunner, and by their combined aid the _Gotha_ could keep all enemy planes at a safe distance. [Illustration: _Copyright Underwood and Underwood_ A GIANT GOTHA BOMBING PLANE BROUGHT DOWN BY THE FRENCH] These, however, were merely protective measures. The Gotha's real mission was bombing, and for this it carried a bomb-releasing mechanism just in front of the pilot's seat, on the floor of the fuselage, while behind the pilot an additional supply of the death-dealing missiles were carried in racks in vertical position. [Illustration: _Copyright Underwood and Underwood_ GERMAN FOKKER PLANE CAPTURED BY THE FRENCH] These were the machines which flew over England and France in 1917 scattering death and destruction. Against them the machines of the Allies were for a time almost powerless, for the best of their airplanes were completely outgunned by this new terror of the skies. The new German machine was given one of its first tryouts in the Balkans, where a squadron of twin-engined _Gothas_ accomplished the bombing of Bucharest. Its efficiency proved, it appeared over the lines and was also used extensively by the Germans for long distance bombing operations. The fact that the _Gothas_ flew in large squadrons made them still more difficult to attack. Yet Allied airplanes went out to give them fight, and in spite of what seemed the almost complete hopelessness of the situation, they did succeed in breaking up _Gotha_ formations and in downing a few of the dread machines. Yet another German twin-winged bombing plane was ready about this time. The _Friedrichshafen_ bomber was not so large as the _Gotha_, but in many points of construction it resembled it. A biplane, it had wings that tapered somewhat from the center to the tips. The wings were strengthened by center spars of steel tubing, which was also used in the construction of the rudder and elevators at the tail. The pilot occupied the rear seat in the cockpit and the gunner the forward seat, while a short passage-way ran between the two. Every effort had been made at camouflage. On their upper surfaces the wings were painted as nearly as possible earth color, so that they might be indistinguishable to a machine looking down upon them from a superior altitude. On their lower surfaces they were painted pale blue, to blend with the sky and make them invisible to an enemy plane below. The armament of this _Friedrichshafen_ bomber consisted of three machine guns, one of them firing downward through a trap door in the fuselage. It was fitted with an automatic bomb-releasing apparatus, by means of which, as one bomb was released, another slipped into place. Other bombing machines appeared in 1917, as the _A.E.G._ twin-motored tractor biplane, and the _A.G.O._ twin-bodied biplane. The Germans also began construction of huge bombing triplanes, heavily armed with machine guns. With squadrons of these, the _Gothas_, and the _Friedrichshafens_, they carried out in 1917 and 1918 an established program of bombardment. The night no longer held terrors for their airmen, who had learned to fly in the darkness. They made their raiding expeditions, not only against Allied troops and military bases, but also on English and French towns, killing civilians and children and destroying property of no importance from a military point of view. By these methods the Hun had hoped to acquire the supremacy of the air which his smaller fighting machines had not yet won for him. Fortunately the French and British had been hard at work, and in answer to the forays of the German bombing planes, squadrons of Allied planes dropped their missiles in the heart of Germany. The Allied planes, however, chose military objectives, and did not aim their blows at defenseless civilians. Stroke for stroke, and with a little extra for good measure the Allies beat back their opponents in the air. To-day some of the most remarkable raiding machines in existence, whether for night or for day work belong to France and England, while America is leaving no stone unturned to build up an air navy the equal of those by whose side she fought. Yet the war in the air, on the Allied side, was always marked by honor, decency and humanity. The enemy repeatedly showed that not mere military gains, but the savage pleasure of bombing civilians, was a part of his air program. In March, 1918, nine squadrons of his airplanes flew over Paris and attacked the city. The raid resulted in 100 deaths, besides 79 people injured, a shocking story to go down in the record of the Hun's attempt at mastery of the air. Mr. Baker, our American Secretary of War, was in Paris at the time when this historic raid occurred. He was holding a conference at his hotel with General Tasker H. Bliss, at the time American Chief of Staff, when the French warning siren was sounded throughout the city. The city was covered with a deep fog, that completely shielded from the view of the German machines any possible objective. But they had no intention of choosing targets for their bombs,--they let them fall at random upon Paris. For almost three hours terror reigned among the helpless civilians; then the raiders, having lost four of their number to the anti-aircraft gunners, turned and sped swiftly toward their own lines. "It was a revelation," said Mr. Baker, "of the methods inaugurated by an enemy who wages the same war against women and children as against soldiers.... We are sending our soldiers to Europe to fight until the world is delivered from these horrors." London as well as Paris suffered from enemy bombing planes. Raid followed raid in the Spring of 1918, but the British had so improved their aerial defenses that they were able to meet the attempted ravages of the enemy with the most powerful anti-aircraft guns, which, like a wall of fire, forbade the dread monsters to come within the limits of the metropolis. Many machines in the German squadrons never got close enough to London to bomb it, but those which did let fall their terrible explosives without aim or object, killing and maiming a large number of civilians. The British were finally forced to take the only course which could have effect with the Hun. They flew into the heart of the enemy's country and gave him a taste of his own medicine. True, they chose their objectives carefully, and the targets which they bombed were munition works, railways, factories, and camps, but for all their tempered revenge they made the foe smart beneath the stinging lash that descended, again and again, upon his back. In answer to the aircraft program of the United States, Germany renewed her energies, and her construction of airplanes during the last year of the War was on a larger scale than ever before. Her small fighting machines, or speed scouts, include the _Fokker_, the _Halberstadt_, the _Roland_, the _Albatros_, the _Aviatik_, the _Pfalz_ monoplane, the _Rumpler_, the _L.V.W._ and a number of others. Some of these we have already seen at work. The _Roland_ is one of the latest types of German two-seater scouts. Every effort has been made in it to decrease the "head resistance" by careful streamlining, reduction of the number of interplane struts, etc. Swift flying and a rapid climber, it has won for itself the title of _The German Spad_. The _Pfalz_ is built either as a monoplane or as a biplane. It is a machine somewhat similar to the _Fokker_. The monoplane, however, has two machine guns, one on each side of the pilot, and firing through the propeller. Among airplanes used by the enemy for general service duties over the lines, the _A.G.O._, the _A.E.G._ and the _Gotha_ undoubtedly take the lead. All are heavily armed with machine guns and bombs and are driven by powerful motors. Yet for all the desperate German struggle for supremacy, her machines and her pilots did not prove the equals of the Allies in the air. The airplanes of France, England, Italy and America maintained a ceaseless vigilance over the lines, giving chase to every enemy plane or squadron of planes that made its appearance on the horizon. Our airmen showed the most dauntless courage, and they continually outwitted and outmaneuvered the slower thinking Hun. Our speed scouts challenged his reconnaissance and bombing planes, and prevented them from performing their missions effectively; our own reconnaissance airplanes gave him a hard time of it; and our bombing machines proved themselves the strong right arm of the service--taking the place of the big guns in raining heavy explosives upon enemy troops, bombing his military bases, and making life in general most uncomfortable for the foe. It is a far cry from those first standardized _Taubes_ to the many makes and patterns of German airplanes of the present day. As the Allies met those first maids-of-all-work with a mixed company of airplanes of many and untried talents, so to-day they are meeting her efforts to imitate their own versatility in aircraft with machines which are carefully standardized in every detail. It should be an object lesson to Germany that the Allies have triumphed in each case. CHAPTER VIII HEROES OF THE AIR Heroes of the air in peace times have been numerous. We already know the stories of many of the pioneers of aircraft, who risked their lives in situations involving the utmost peril. The men who, in the first frail monoplanes and biplanes attempted to fly the British Channel, or to make dangerous cross-country flights under adverse weather conditions were heroes indeed. Yet undoubtedly the greatest exploits will be told of those heroes who, in the Great War, flew daily over the lines, meeting the aviators of the enemy in mortal combat. Every allied nation engaged in the great conflict has her sacred roll of honor of those who fought for her in the air. Americans will never grow weary of tales of the great Lufbery; Englishmen will boast of the prowess of Bishop, McCudden and the rest of them; while Frenchmen will tell, with mingling of joy and sadness, of the immortal Guynemer, Prince of Aces. Georges Guynemer's name will always stand first on the record of the war's great flying men. His short career was a blaze of triumph against the Hun, but with many a hairbreadth escape from death and many a feat of reckless daring. Young, handsome and dashing, anxious to give his life for his beloved France, he became the adored idol of the French nation. On one occasion when he marched in a parade in Paris, the people strewed his path with flowers, and it was necessary for the police to intervene and protect him from the enraptured multitudes who pressed forward to embrace him. Yet Guynemer came near missing the fighting altogether. Guynemer was born on Christmas day, 1893, in the town of Compiègne. He grew up a tall, delicate boy, who, his friends predicted, would never live to reach maturity. Perhaps the fact that he was almost an invalid turned his attention away from the athletic sports of the other boys and gave him his intense interest in mechanics. He had one consuming ambition: to become a student in the École Polytechnique in Paris; but when by hard study he had finally prepared himself and came up for his entrance examination, the professors of the school rejected him on the ground that he might not live to finish the course. To help the lad forget his overwhelming disappointment, his parents hurried him away to a health resort at Biarritz. He had been there a year when in August, 1914, came the news that his country had been attacked. Burning with zeal to help defend his beloved France, Guynemer offered himself again and again for enlistment in the French army. Hard pressed as that army was, its officers did not feel that they needed the sacrifice of a frail youth with one foot in the grave. Gently but firmly, the young candidate was rejected. Bitterly humiliated he went back to his life of enforced inaction; and while he saw his comrades marching forth to war, he eagerly pondered in his mind what service he could perform in the war against the invader. At length he hit upon an idea. Since he could not become a soldier, why should he not turn his mechanical skill to some account in one of the great airplane factories where France was turning out her swift squadrons of the air. He volunteered and was accepted. In a short time he had made his presence felt, for he had received a thorough preparatory education in mechanics and was far the superior of the majority of his fellow workmen. Little by little he won the friendship and admiration of his superiors, who promoted him to the position of mechanician at one of the big military aviation fields. Now for the first time he was living among war scenes. While he performed his humble duties in the hangar he burned with ambition to pilot over the lines one of the swift French battle planes. But he hardly dared make the request that he be taught to fly, fearing the rebuff which he had received on every other occasion when he had sought to enlist. But the officers at the aviation camp had been watching young Guynemer, and their respect for his nobility of character and high intelligence finally outweighed their fears that he might prove too delicate for the service in the air. So the happy day finally arrived when he was permitted to enlist as a student airman. In January, 1916, having completed his course of training, he flew for the first time in a swift scout plane. From the day that he first flew out over the lines, his higher officers realized that here indeed was a master airman. In three short weeks he had won the distinction of "ace," having downed his fifth enemy machine. The secret of his success lay partly in the frail constitution which had come so near condemning him to inactivity. For the youth was fully convinced that he had not long to live, and his one idea was to die in such a way as to render the greatest possible service to his native land. Perfectly prepared to meet death when the moment came, he was scrupulously careful never to court it unnecessarily, for he realized that the longer he lived the more damage he would be able to inflict upon the enemy. The early morning invariably found him in his hangar, going over with loving care every detail of the mechanism of his swift scout plane. Not until every portion of engine, wings, struts and stays had been tried and proved in A-1 condition, and every cartridge removed from his machine gun and carefully tested, did he climb into his pilot's seat and wing his way across the sky in search of enemy planes. And when Guynemer encountered an enemy plane he maneuvered to overcome it with the same care for exactness of movement. His cool-headed precision made it almost impossible to take him by surprise, while there was many a hapless machine of the enemy that he pounced upon unawares. He was an accomplished aerial acrobat, and one of his favorite tactics was to climb to a great altitude and then, pointing the nose of his plane at his prey, to suddenly swoop down at enormous speed, firing as he came. Expert as he was, the great French aviator had a number of narrow escapes from death. In September, 1916, seeing one of his fellow aviators engaged in an unequal combat with five German _Fokkers_, he sped to the scene of the affray. Maneuvering into a favorable position above his opponents he shot down two of them within the space of a few seconds. The remaining three _Fokkers_ took to flight, but Guynemer was hot on their trail. Another of them went crashing earthward. Suddenly, as the plucky Frenchman sped on, hot on the trail of the two that were still unpunished, he was startled by the bursting of a shell just under his machine. One of the wings of his plane had been torn completely away, and from a height of ten thousand feet in the atmosphere, he began falling rapidly. He struggled bravely with the controls but nothing could check the ever increasing speed of his plunge earthward. At an altitude of five thousand feet the airplane commenced to somersault, but the pilot was strapped in his seat. Then, as if some unseen force had intervened, the swiftness of the descent was unexpectedly checked. With speed greatly lessened the airplane came crashing to the earth, and the plucky aviator was rescued from the débris, unconscious but not seriously hurt by his dreadful fall. It was for this exploit that he received the rank of Lieutenant, while he was decorated with the much-coveted French War Cross. On another occasion Guynemer's machine was shot down by German shells, and came crashing to earth in No Man's Land, between the French and the German trenches. The Prussians turned their machine guns on the spot and plowed the area with scorching fire. But the French had seen their beloved hero fall, and without a thought for the consequences the poilus in the trenches went "over the top" after him. Quickly they bore him back to safety, and if they left some of their comrades fallen out in that dread region, they did not count it too great a sacrifice to have redeemed their idol with their blood. Practically every fighting nation has had not only its favorite airman but also its favorite aerial escadrille. Guynemer was the leader of the famous band of "Cignognes" or "Storks," into which had been gathered the pick of all the flying men of France. His historic opponent in the war in the air was the German Baron von Richthofen, whose squadrons were humorously nicknamed "Richthofen's circus" by the Allies, because of their curiously camouflaged wings. The Germans were very jealous of Guynemer's successes, and as the record of the number of machines he had downed grew, they eagerly credited Richthofen with more victories. Guynemer's final score was 54 and his enemy's much higher. Yet as a matter of fact the Frenchman had destroyed many more machines than Baron von Richthofen, for whereas the French gave no credit for planes sent to earth where no other witnesses than the pilot could testify to their destruction, the Germans were very glad to pile up a huge score for their hero, and were not by any means critical in seeking proof of a victory. Guynemer's remarkable aerial victories made him a hero throughout the world. It was reported that in one day he had been officially credited with the destruction of four airplanes of the enemy. One of his chief ambitions was to bring down an enemy machine within the allied lines, as little damaged as possible. Such a plane gave him an opportunity to indulge his interest in the purely mechanical side of aviation. With the utmost patience he would examine it in every detail, making note of any features which he regarded as improvements on the _Nieuport_ he himself flew. Such improvements would very shortly appear on his own machine. So while Guynemer flew a _Nieuport_, it was in reality a different _Nieuport_ from any doing service over the lines. In its many little individual features and appliances it reflected the active, eager, painstaking mind of its famous pilot, whose mind was ever on the alert to discover the tiniest detail of mechanism which might gain for him an advantage over his adversaries. It was on September 11, 1917, that the beloved aviator fought his last battle in the air. While in flight over Ypres he caught sight of five German _Albatros_ planes, and instantly turned the nose of his machine in their direction. As he bore swiftly down upon them, a flock of enemy machines, over forty in number, suddenly made their appearance and swooped down from an enormous height above the clouds. Baron von Richthofen with his flying "circus" was among them. None of Guynemer's comrades was near enough to aid him. In the distance a group of Belgian machines came in view, rushing to his assistance, but before they had arrived at the spot the plucky French airplane was observed sinking gently to the earth, where it disappeared behind the German lines. Guynemer's comrades cherished the hope that he had been forced to descend and had been taken prisoner by the Germans. Such an ending to a glorious career of service would perhaps not have been desired by the aviator himself. He who had used his life to such good advantage for his country had crowned his victories with death. The Germans themselves, out of respect for his memory, undertook to inform his fellow-men of his fate, and a few days later they dropped a note into the French aerodrome stating that he had been shot through the head. The German pilot who had killed him was named Wissemann, and he was an unknown aviator. When he learned that he had actually killed the great Guynemer, he wrote home to say that he need now fear no one, since he had conquered the king of them all. It was scarcely a fortnight before he was sent to his death by a devoted friend of his renowned victim. The man who avenged the death of Guynemer was René Fonck, likewise a member of the French "Cignognes." Fonck took up the championship of the air where his comrade had laid it down. He stands to-day as the most remarkable of all the French aviators. He has been called "the most polished aerial duellist the world has ever seen." With an official record of almost half a hundred enemy machines destroyed, he has astounded his spectators by his aerial "stunts" and the absolute accuracy of his aim. Many of Fonck's successful battles have been fought against heavy odds, quite frequently with as many as five of the enemy's airplanes opposing him. Yet with apparent ease he invariably succeeded in warding off his would-be destroyers, whilst one by one he sent them flaming to the earth. It has been said of Fonck that in all his battles in the clouds he never received so much as a bullet hole in his machine, thanks to his unparalleled skill at maneuvering. He made a world's record at Soissons in May, 1918, when he downed five enemy airplanes in one day. He was flying on patrol duty when he came upon three German two-seater machines, and in less than 10 seconds sent two of them flaming to earth. Later in the same day he actually succeeded in breaking up a large formation of German fighting machines, and after destroying three, sent the rest fleeing in confusion. On another occasion Fonck made a world's record when he brought down three German planes in the brief space of 20 seconds. While in flight above the lines he came upon four big biplanes of the enemy, flying in single file, one behind the other. He quickly pounced upon the leader, and in less time than it takes to tell, had sent him crashing to the earth. The second had no chance to alter its course. Training his machine gun on it Fonck soon sent it, a mass of flames, after its fellow. The third big biplane dodged out of the line and sped out of harm's way, but the fourth was caught by the plucky Frenchman, who wheeled his machine round with startling rapidity and fired upon it before it could make good its escape. This remarkable feat, performed in August, 1918, brought Lieutenant René Fonck's official total of victories up to sixty, and made him the premier French ace, at the age of twenty-four. In all his aerial battles he had never been wounded, passing unscathed through the most formidable encounters by reason of his unparalleled skill at maneuvering. Guynemer and Fonck are perhaps the two greatest names on the French roll of heroes of the air. But there were many other Frenchmen who did valiant service. Lieutenant René Dorine had an official record of 23 victories when he disappeared in May, 1917. He was nicknamed the "Unpuncturable" by his comrades, since in all his exploits above the lines his machine had only twice received a bullet hole. Lieutenant Jean Chaput had a record of 16 enemy planes destroyed, when in May, 1918, he made the great sacrifice; and there are many others, some living and some fallen in battle, who, flying for France, day after day and month after month, helped to make her cause at length a victorious one. The "ace of aces" among British flying men of the war is Major William A. Bishop, who holds the record of 72 enemy airplanes downed. Second to him on the British list stands the name of Captain James McCudden, who had disposed of 56 of his enemies when he himself was accidentally killed. McCudden had had a most picturesque career. He joined the British army as a bugler at the age of fifteen. As a private he fought with the first Englishmen in France in 1914. His first flying experience came at Mons, when owing to the scarcity of observers he was permitted to serve in that capacity. He rapidly made good, and was soon promoted to the rank of officer. He proved himself a clever aerial gunner, and so won the opportunity to qualify as a pilot. With a fast fighting machine of his own he became a menace to the Hun, with whom he engaged in over 100 combats during his flying career, yet never himself received a wound. Other English fliers made special records in the Great War, as Captain Philip F. Fullard, who downed 48 enemy machines; Captain Henry W. Wollett, who accounted for 28; and Lieutenants John J. Malone, Allan Wilkinson, Stanley Rosevear and Robert A. Little, all with scores of from 17 to 20. Captain Albert Ball, who was shot down by Baron von Richthofen in 1917, had an official score of 43 victories over the Hun, with the additional honor of having conquered the great German aviator Immelmann. And now we come to the story of America's great fliers. Long before America herself had entered the World War there had arisen a valiant little company of her sons, who, remembering our ancient debt to France, had gone to fight beside her men in the war against the invader. Many of these Americans became skilful aviators and members of the squadron which the French had appropriately named the "Lafayette Escadrille." In 1916, three of its most distinguished fliers--Norman Price, Victor Chapman and Kiffen Rockwell--gave their lives to France. Probably the name which all Americans know best is that of Major Raoul Lufbery, till his death American "ace of aces," who flew with the Escadrille under the flags of both countries. Major Lufbery's personal story is romantic as any fiction. He was a born soldier of fortune. When a very young chap he ran away from home and for several years rode and tramped over Europe and part of Africa, working at anything that came to hand. After his early wanderings there followed two years of strenuous service with the U. S. regulars in the Philippines; and after that another long, aimless jaunt over Japan and China. It was in the Far East that he came by chance upon Marc Pourpe, the French aviator who was giving exhibition flights and coining money out of the enthusiasm of the Orientals. The two men became fast friends and Pourpe took Lufbery along with him on his travels. As an airplane mechanic under Pourpe's direction Lufbery found his first serious employment and also his first serious interest. He conceived a deep interest in aviation and became an apt pupil. Then came the war, and Pourpe offered his services to France. Lufbery went along as his mechanic. It was only a few months before his friend had fallen, and Lufbery, anxious to avenge his death, sought admission to the ranks of French fliers. In 1916, after much excellent service over the lines, he became a member of the Lafayette Escadrille. The spectacular period of his career had now begun. He had soon claimed the five official victories necessary to make him an "ace," and in addition was presented with the Croix de Guerre for distinguished bravery in action. With his swift _Nieuport_ he engaged in combat after combat, coming through by sheer cool-headedness and skill born of long experience. He was officially described by the French Government as "able, intrepid, and a veritable model for his comrades." In November, 1917, America had the honor of claiming back her son, when he became a major in the U. S. service and commanding officer of the Lafayette Escadrille. And it was with the utmost sorrow that the American public, a little over six months later, read that our great aviator had met his death. He fell on May 19, 1918, in an attack on a German "armored tank," which already had sent five American airplanes plunging to earth. Lufbery's official total was 17 German planes destroyed, but actually he had accounted for many more. He had been made a Chevalier of the Legion of Honor by France, and like others of his American comrades had done much to cement the friendship between the two countries. Another American ace who deserves the gratitude of the American people, not only because he brought down twenty-six German aircraft but because of the extraordinary inspiration of his example as a leader at the front to other American air fighters, is the present premier American ace, Captain Eddie Rickenbacker, idol of the automobile racing world before the war. America's entrance into the war fired Rickenbacker with an ambition to get into the fighting at all costs and after an attempt to organize a squadron composed of expert auto racing men, unsuccessful because of lack of funds, he enlisted in the infantry. He became General Pershing's driver at the front and while serving in this capacity watched his chance to get into the flying end of the air service. An opportunity soon presented itself and Rickenbacker advanced rapidly. In eighteen months he had, as commanding officer, perfected the finest and most efficient flying squadron in the Allied armies, and had become America's ace of aces. His service was distinguished by untiring energy, devotion to his men and sacrifice of personal ambition in the demands of his duty as a leader, for it is a self-evident fact that had Rickenbacker been a free lance, he might easily have doubled his score of victories. He is a chevalier of the Legion of Honor, has received the Croix de Guerre with three palms, and also the Distinguished Service Cross with nine palms. [Illustration: CAPTAIN EDDIE RICKENBACKER] A particularly lovable figure in American aviation during the war was Edmond Genet, who fell in the Spring of 1917 while serving under the Stars and Stripes. Born in America, young Genet was descended from the first French minister to the United States. The two countries were equally dear to him. When he died, at his own request the Tri-color and the Stars and Stripes were placed side by side over his grave, as a mark, so he said "that I died for both countries." [Illustration: _Copyright International Film Service, Inc._ THE FIRST BAG OF MAIL CARRIED BY THE U. S. AERO MAIL SERVICE] It would be impossible to enumerate in one short chapter all the brilliant records that were made during the war by the aviators of the allied nations. The best we can hope to do is to remember those names which stood out most prominently in the long story of victories won and sacrifices made to the cause of the world's liberty. Opposing our brave men there was, from time to time, a German flier who attained considerable renown, and who, for a time at least, baffled his opponents. Thus in the early days Immelmann and Boelke were much heard of. Each had his peculiar method of maneuvering and fighting. Immelmann's favorite trick was to "loop the loop" in order to get out of the way of an enemy's gunfire, suddenly righting himself before the loop was finished, in order to fly back and catch the opposing airman unawares. By this "stunt" he succeeded in sending 37 Allied aviators to their deaths, before he himself was shot down by Captain Albert Ball of the British Royal Flying Corps. Captain Boelke had a totally different method of attack from that of Immelmann. His favorite pastime was to lurk behind a cloud at a great altitude, until he spied an airplane of the Allies below him, when he would point the nose of his machine straight at his victim and dive for it, opening fire. In case he missed his target he never waited to give battle, but continued his descent until he had made a landing behind the German lines. According to the lenient German count, he had scored 43 victories up to the time of his death. It was an American, Captain Bonnel, in the British air service, who finally defeated and killed him in October, 1916. Early in the war the Germans discovered that, however perfect their airplanes might become, their airmen were not the equals of those who were flying for the French and British. The German works much better under orders than where, as in aerial combat, he is required to rely entirely upon his personal initiative. The Allied airmen therefore soon claimed supremacy over the lines, and it was in order to wrest it from them that the Germans began turning over various schemes in their mind. The one which proved acceptable in the end has been credited to Captain Boelke. It was that of sending German aviators out in groups to meet the Allied fliers, each group headed by a commander. This plan at least proved much more successful than the old one of single encounter. Thus Boelke became the commander of a German squadron, which after his death passed to the leadership of Baron Max von Richthofen. Richthofen was one of the cleverest of the enemy aviators and in time he made his squadron a formidable aerial weapon. He conceived the idea of camouflaging his planes in order to render them invisible at high altitudes. Accordingly he had all the machines under his command gaudily colored. He presented a curious spectacle when he took to flight with his gaudily painted flock of birds and the British promptly nicknamed his squadron "Richthofen's circus." The "circus" usually consisted of about 30 fast scout machines, with every pilot a picked man. Freed from all routine duties over the lines its one object was to destroy, and so it roved up and down, appearing now here, now there, in an effort to strike terror to the hearts of British and French airmen. It took a large toll of our best fighters, although Richthofen's personal record of 78 victories was undoubtedly exaggerated. The most effective fighters against this powerful organization were the members of the world-famous Hat-in-the-Ring Squadron commanded by Captain Eddie Rickenbacker, America's ace of aces. Day after day they went out against the boasted champions of the German Air Service and day after day they came in with German planes to their credit. At the close of the war they had won a greater number of victories than any other American squadron. The Hat-in-the-Ring was the first American squadron to go over the enemies' lines, the first to destroy an enemy plane and it brought down the last Hun aeroplane to fall in the war. After the signing of the armistice it was distinguished by being selected as the only fighting squadron in the forces to move into Germany with the Army of Occupation. It will doubtless go down in history as the greatest flying squadron America sent to the war. On April 21, 1918, the "circus" was in operation over the Somme Valley, over the British lines. Several of its fighters attacked a couple of British planes unexpectedly, and quite as suddenly the whole squadron swooped down out of the blue. Other British airplanes rushed to the spot from all directions and there followed a confused battle which spread over a wide area. One of the German planes which had been flying low came crashing to earth. When the wreckage was removed and the body of the pilot recovered he was found to be no other than the great Richthofen himself. Thus the greatest of the German champions was downed. He was buried with military honors by the British, but the menace which he stood for had happily been destroyed. CHAPTER IX THE BIRTH OF AN AIRPLANE Out in the forests of the great Northwest there stands a giant spruce tree, tall and straight and strong, whose top looks out across the gentle slopes of the Rocky Mountain foothills to the Pacific. For eight hundred years, perhaps, it has stood guard there. Great of girth, its straight trunk rising like a stately column in the forest, it is easily king of all it surveys. Someday the woodsmen of Uncle Sam come and fell that mighty spruce. And then begins the story of its evolution, from a proud, immovable personage whose upper foliage seemed to touch the clouds, to a strong and lithesome bird who goes soaring fearlessly across the sky. Uncle Sam has had an army of over ten thousand men in the woods of Oregon and Washington during the past year, selecting and felling spruces for airplane manufacture. Only the finest of the trees are chosen, and lumber which shows the slightest defect is instantly discarded. The great logs are sawed into long, flat beams, and are carefully examined for knots or pitch pockets or other blemishes which might impair their strength when finally they have been fashioned into airplane parts. These beams then start on their journey to the aircraft plants, where skilled laborers get to work on them. For the days of the homemade airplane have passed. It is only about fifteen years since the Wright brothers built their first crude flying machine, and, not without some misgivings, made the first trial of their handiwork. Since then airplane manufacture has made many a stride. The flying machine of those days was largely a matter of guesswork. Nobody knew exactly what it might do when it took to the air. Nobody knew whether it would prove strong enough to bear the pilot's weight, or whether it might suddenly capsize in the air and come crashing with its burden to the earth. For the parts had been crudely fashioned by the inventor's own hands. Naturally he was very seldom a skilled cabinet maker, painter and mechanician. He knew very little about the laws of aerodynamics, about stress and strain and factors of safety. He just went ahead and did the best he could and took his chance about losing his life when his great bird took to the air. No wonder the early fliers dreaded to set forth in even a gentle breeze! No wonder there used to be so much talk about "holes in the air" and all the other atmospheric difficulties that beset the pioneers. The wonder is that any of the early fliers ever came off alive with the fickle mounts to whom they trusted their lives. To-day the manufacture of an airplane has been reduced to the most exact of sciences. Every part is produced in large quantities by skilled workmen, and its strength is scientifically determined before it is passed on to become a member of the finished airplane. Sometimes whole factories specialize on a particular detail of the airplane. Here they make only airplane propellers; there only engines; while in this factory the wings and fuselage are produced. Let us imagine ourselves on a visit to one of the great aircraft factories which have suddenly sprung up in the United States and become so busy with the work of turning out a huge aerial fleet. The great trees which were felled in the Northwestern woods have changed greatly in appearance since we saw them last. As a matter of fact for certain parts of the airplane they should have been allowed to lie out in the sun and rain for several years to "season," but the rush to put planes in the air has made this impossible. Instead they have been treated with a special process in order to rid the wood of its impurities. Now the big beams go to the carpenters to be fashioned into the airplane fuselage. The separate boards are carefully cut and fitted and trimmed down to perfect smoothness and symmetry. Painted and varnished the fuselage resembles a fine automobile body. In the top or roof of the fuselage one or more circular openings have been cut. Below, almost on the floor are the seats for pilot and observer, in what are known as the cockpits. While the carpenters and cabinet makers have been busy on the fuselage, more skilled workmen still have been fashioning the airplane wings. This is one of the most difficult and delicate tasks of all. Remember that the curve of the wing determines to a large extent the speed and climbing powers of the completed airplane. The wing is built up of a number of ribs which give it the proper curve and shape. Each of these ribs must be accurately manufactured from a prescribed formula. First a piece of board is turned out which looks exactly like a cross section of a wing. But there is no need for solid wood to add to the weight of the wing, and so all over its surface the workman goes, boring out circular pieces, until only a framework remains. On its upper and lower edges a flexible strip of wood is bent down to its shape and strongly attached. The rib is now complete. A number of ribs placed in a row begin to suggest the outlines of a wing. They are connected by long beams which run from tip to tip of the wing. When these have been fastened in place the skeleton is completed and the work of the carpenters is over for a little while. The next step is to place upon this wing skeleton its linen covering. The linen is usually cut in gores or strips which are sewed together, and then the whole piece is stretched as taut as possible upon its framework, above and below the ribs. Sometimes the seams run parallel to the ribs and are tacked down to them, but seams which run diagonally across the wing have been found more satisfactory. Of course it is practically impossible to stretch the fabric absolutely tight over the frame so that it will not sag when subjected to the heavy pressure of the air. Various methods were tried in the early days to tauten and strengthen the fabric. To-day the covered wing is treated with a substance known as "dope," which shrinks it till it is "tight as a drum." Dope renders the wing both air-proof and rainproof. It strengthens the fabric and makes it able to bear the terrible stresses to which it will be subjected when the airplane is racing through the sky. But it cannot be applied carelessly, and right here the skill of the very best painters is brought into play. These painters spread first two very thin coats of it over the fabric, filling up the pores so that later coats will not run through into the interior of the wing. Next two or three thicker coats are applied. After this the wing may receive several coats of varnish, while if it is a U. S. service plane it gets a final covering of white enamel, which protects the fabric from the injurious action of the sun's rays. Now the wings and fuselage of our airplane are ready, and the rudder, the elevating surfaces and the ailerons are in course of production. They are made in the same manner as the wings, with a wooden framework over which fabric is stretched and "doped." We begin to think our big bird is almost ready to be put together, but we have forgotten two important items: the engine and the propeller. The airplane manufacturer usually does not attempt to build his own engines or propellers. He buys his engine all ready to be installed and procures his propeller from a factory which makes this its specialty. For the propeller is one of the most difficult parts of the airplane to produce. Above all things it must be strong, and for this reason steel has been tried in its manufacture. Curiously enough it was found that the metal propeller could not stand up under high speeds and stresses as well as one built of wood. Many kinds of wood are used in propeller construction, and the choice depends very largely on the speed and stress--in other words on the horsepower of the engine. Sometimes a propeller is built of alternating layers of two different kinds of wood. But with high-powered engines oak is very generally employed on account of its strength. An airplane propeller is not carved out of a single block of wood, for in this case it would not be strong enough for the difficult task it has to perform of cutting its way through the atmosphere and drawing the airplane after it. Instead it is built up of a number of thicknesses of specially seasoned wood, so arranged that the surface is formed by the cross grains of the various layers. This result is produced by first piling up a number of boards to form a block out of which the propeller can be carved. The boards are glued firmly together and then they are subjected to tremendous pressure. Now expert wood carvers begin their delicate task of turning out a propeller of a given pitch. Their work requires the utmost skill, but they succeed, until gradually the finished article begins to take form out of the crude block. A coat of varnish, a fine metal hub--and our propeller is ready to be shipped to join the wings and the fuselage and complete the manufacture of a modern airplane. There are several other items--such as the steel landing chassis, the steering instruments and the upholstery--which we must have on hand before we are ready to commence the work of assembling. When all have been procured the happy task begins. The wings are put in place, and carefully secured by wires and supporting struts. The steering apparatus is installed, the cushioned seats are placed in the cockpits, the fuselage is mounted on the wheeled chassis, and finally when all is complete the big bird is sent out for its first test flight. If there is any one way in which the airplane of to-day differs radically in its process of manufacture from the airplane of a few years ago it is in this: that it is a _tested_ machine. The greatest enemy of the aviator was and always will be, not so much the bullets of an enemy as the hidden flaw in his machine's construction, which makes it "go back on him" when he least expects. The pioneer aviator built himself what he considered a "strong airplane," but when he attempted flight under weather conditions not so favorable as those on which he had counted, some untested part gave way. So in the early days there were many tragedies. To-day, the airplane has become a safe mount indeed, for not only is the finished machine tried out before it is put into use, but each separate part is subjected to the most exacting series of tests. If it does not bear up under at least six times the strain it will ever be called on to endure in flight, it is rejected as unfit. That is the reason the aviator of to-day dares to perform all the marvelous tricks in the air of which we read. Back of the stories of heroism and daring that have come from the battle line during the Great War, and back of the great commercial feats and enterprises that are being planned for the near future, we must not lose sight of the remarkable progress in airplane manufacture and the careful painstaking research and experiment that have resulted in greater safety in the air. Of course it was the war that spurred every one on to do his best in the design and construction of airplanes. Before that time England and America had made very poor showings, and France, although deeply interested in aviation, had nothing in the way of a flying machine that would not seem ancient compared with the airplanes of the present time. America came into the field of action late, and up to the time she entered the war she had practically no airplane industry whatever. Yet when she did get in she set to work with a will, and as every one knows she succeeded in making a real contribution to aviation in the war. Every brain that could be of service in our great country was mobilized. The automobile manufacturers did much for the cause, some surrendering their trade secrets for the good of the cause, and others turning over their large organizations to airplane construction. As a result, a recent report stated that there were 248 factories in the United States making planes, with over 150,000 men working on aircraft. In a single year this giant industry has sprung up, and the mechanical genius of America has been focussed upon this latest problem: the heavier-than-air machine. It is inconceivable that our country, which can boast the invention of the airplane, should in peace times allow this great industry to wane. For a long time we slept while France was forging ahead in the design and construction of machines. The commercial uses of the airplane will be numberless, and it is bound to assume an ever more important and practical role in everyday life. America has the natural resources, and now that she has developed the tools with which to work and has trained a large body of young men to be capable pilots, she should look forward in the future to maintaining her proper place among the nations in airplane manufacture. The big bird of the sky who had his birth in America and who grew to such enormous proportions during the strenuous days of war, must not be allowed to lose his American manners when he turns to peace pursuits. CHAPTER X THE TRAINING OF AN AVIATOR It is a rocky road that leads from the obscurity of civilian life to the glory and achievement of a successful "bird-man." The man--or the boy--who elects to follow it must be possessed of brains, physical perfection, and iron grit, for he will need them all if he is to become one of the "heroes of the air." With one's feet on solid earth it is easy enough to make mistakes and profit by them, doing better the next time. The airman seldom profits by his serious blunders, for he is no longer on the scene when the experts are pointing out what error he was guilty of. The moment his machine, after a run across the ground, suddenly lifts and goes skimming off into the blue, he must depend upon himself. No friend upon the earth can shout to him any advice; his own unfailing knowledge and quick judgment must dictate in every emergency and see him through until once more he alights upon this old world. Fortunately the War has proved that there were many young men able to do just that--depend upon themselves in situations so critical that the slightest deviation from the right course, the slightest hesitation about what to do next, would have cost them their lives, and their government a costly airplane. Such men have covered themselves with glory, and have won the love and admiration of their people. But they did not achieve their daring exploits nor make their marvelous records in the air until they had passed through a series of tests and a system of training so rigid that it might well have discouraged the most stout-hearted. Why must the aviator be physically perfect? Just imagine for one moment some of the hardships and perils he will have to face. The higher the altitude at which he flies, the more intense becomes the cold. In some regions of the upper air temperatures as low as 80° and 90° below zero have been recorded by fliers. And rushing through the air at such speeds as 150 miles an hour produces a strain upon the lungs which only the strongest and sturdiest can endure. Nor is this all. The tiniest defect in the mechanism of the inner ear may cost the airman his life, if he undertakes night flying. If only he were required to fly in broad daylight when there were neither clouds nor darkness to obstruct his view of Old Mother Earth, he might manage to get along with a less-than-perfect ear. But at night,--on a cloudy night at that, when there are no lights on earth to guide him and no stars visible in the sky--the aviator faces some of his gravest perils. Strange as it may seem it is often very difficult for him to tell whether his machine is in a horizontal position, whether he is flying right-side-up or is toppling over at a perilous angle. The only thing which helps him in this extremity is a slight reflex action in the inner ear which warns him of any loss of "balance." In the same way perfect vision is absolutely essential to the man who must be prepared for any sort of aerial emergency. This does not mean merely "seeing well." It means the absolute working right of the lens and muscles of the eye, their quick readjustment to normal after any series of loop-the-loops, after a nose dive or any sort of acrobatic stunt an airplane may be called on to perform. So it goes with every one of the physical requirements laid down by the military authorities for men who would become fliers--they are not just arbitrary requirements, but are based on long experience of the demands which flying makes upon the system. In peace times the aviator may be able to get along with somewhat less than the physical perfection required of the military aviator, particularly if he takes up flying merely as a sport, for he will be able to spare himself the night flying and all the other difficult feats which have been required of the aviators in the war. But the next few years are going to see many new commercial duties opening to the airplane, and the pilots who guide these great ships of peace and industry will no doubt be chosen by just as high standards as our military aviators. The room in which the would-be military aviator receives his physical examination has been jokingly referred to as "the Chamber of Horrors," and he reaches it after a short preliminary test of heart, lungs, and ear. As he sits side by side with his fellow applicants in the outer waiting room, he cannot help a feeling of "creepiness." At intervals a doctor appears at the door of that secret chamber and beckons another unfortunate in. He remembers all the grewsome stories he had heard of happenings in that room behind the closed door and his knees commence to shake. Gradually the minutes pass and by a supreme effort he begins to recover his nerve. Suddenly the door opens and a white faced applicant rushes out. The poor would-be aviator regrets his rashness in deciding to learn to pilot one of the big birds of the air. But it is his turn next, so, appearing as unconcerned as possible, he follows the doctor in. He is ordered to sit down in a small chair to the back of which is attached a bracket for his head. The clamps are adjusted to hold his head firm, he is told to fix his gaze on a point ahead, and then suddenly, he commences to whirl around. Round and round he goes, ten times in 20 seconds. The chair comes abruptly to a halt. He must find that point he fixed his eyes on before starting. He struggles vainly to do so, imagining that failure means immediate rejection, but his eyeballs are turning rapidly back and forth. At last they stop, the physician calls out the number of seconds to his assistant. The same experiment is tried in an opposite direction, similar ones follow, and then the unhappy applicant braces himself for one of the most severe of all the physical tests. His head is released from the clamp in which it has been held, and he is instructed to clench his hands upon his knees and rest his head on them. This done, the chair begins whirling once more. As it comes to a sudden halt, he is sharply ordered to raise his head. He has the impression that he is falling rapidly through space, and a dizzy "seasickness" almost overcomes him. Finally his eyeballs cease their swift gyrations. The instructor has timed them with a stop-watch. He is excused from the room, and, feeling like a man who had been through a siege of illness, he makes a dash for the open air. If the applicant for service in the air has passed his preliminary tests successfully, he may shortly find himself at one of the government's "ground schools," where his education in airplane science begins. Actual flight is still a long way off: he must first receive some rudimentary drill in ordinary "soldiering," and next be put through an intensive course of training in a positively alarming number of studies, before he even approaches the joyful moment when he may begin to think of himself as even a fledgling aviator. In the next few weeks he must become something of a gunner, a telegraph operator, a map-reader, a photographer and a bomber; he must make the acquaintance of the airplane engine in the most minute detail; go through a course in astronomy and one in meteorology; and learn the use of the compass and all other instruments necessary in steering an airplane along a definite course. Aerial observation forms no small part of his course of studies. Sitting in a gallery and looking down upon a large relief map whose raised hills, buildings, streams, and trenches give a very fair reproduction of the earth as it will look to him when he flies over it in a machine, he learns to pick out the objects of strategic importance, and to prepare military reports which will help the staff officers in their work of directing hostilities. Or he may have to report the results of a mock bombardment, and thus prepare himself for the duties of the artillery "spotter." In order to be able to interpret with a fair degree of intelligence the things he will see as an aerial observer, he must know a good deal about military science and strategy himself, and this forms one of the subjects in his curriculum at the ground school. His life here is a strenuous one. He rises soon after five in the morning, and from then until lights go out for the night at 9:30 he has all too little time to call his own. Before he is finally passed out of the ground school the cadet must prove that he understands thoroughly the principle of flight, the operation of an internal combustion engine, and the care and repair of a machine. He will be able to recognize the various types of airplanes, he will have some skill at aerial observation, and he will be able to operate an airplane camera, a bomb-dropping instrument and a range-finder, a wireless or a radio instrument. He will have been instructed in signaling with wigwag and semaphore, in the operation of a magneto, in the theory of aerial combat, and in a number of minor subjects such as sail-making, rope-splicing, etc. Thus prepared in his "ABC's," the would-be aviator finally makes his departure for the actual flying school. Here he does not shake off dull class-room routine and launch forth upon a career of aerial adventure. Quite to the contrary his intensive training in the technical side of aviation becomes even more exacting. He takes apart and puts together again with his own hands various types of airplane engines, he practises gunnery at a moving target, he assembles an airplane out of the dismantled parts. He does, however, have that wonderful experience, his first flight. Some fine morning he is told that the instructor will take him up, and, thoroughly bundled up for warmth in a leather jacket, woolen muffler, heavy cap, etc., with goggles and other little essentials of an aviator's dress, he climbs into the machine. He expects to acquire considerable knowledge of the science of aviation on that first flight. As a matter of fact his mind is so completely overwhelmed by the many new sensations that come to it, that it is only a long time after that he is able to sort them out and form an accurate conception of the adventure. The roar of the motor is deafening as the big bird of the air goes taxiing across the earth. He does not realize that he has left the ground, until suddenly, looking down, he sees the solid earth receding rapidly from beneath him. Then, unexpectedly the machine gets into the "bumps" and he has a few nervous moments until finally it rights itself and goes skimming off into the blue. The sun is shining and below the earth looks peaceful and friendly. He settles himself more comfortably in his seat and begins to enjoy his little aerial journey. Suddenly, without a second's warning, the airplane dives downward. The sickening drop leaves him a trifle paler, perhaps, and he no longer has the pleasant sensation of relaxed enjoyment. He hardly knows what to expect next, and the instructor, bent on testing his nerve takes him through stunt after stunt, climbing, turning, diving. At length the airplane glides gently to earth. A short run over the ground once more, followed by a full stop; and the young gentleman who went up a few minutes ago with a good deal of vim and self-assurance climbs out with a feeling of relief and satisfaction that his feet are once more on terra firma. But do not imagine that he has lost his enthusiasm for the air. If that were the case then he would not be of the stuff of which aviators are made. At the worst reckoning he has acquired an intense ambition to some day "try it on the other fellow," and this in all probability he will do, when, in the course of time he has become an experienced and seasoned airman. In the meantime, however, he must first accustom himself to the "feel" of the air, and next he must learn the operation and control of the airplane in flight. After a few first trips as a "passenger," he will be allowed to try his hand at steering the machine. This is done by what is called a dual control system. Instead of the single control-stick and steering-bar of the ordinary airplane, the training machine has these parts duplicated, so that any false move on the part of the student flyer may be immediately corrected by the instructor. As long as his movements are the right ones, the instructor does not interfere, but the moment he makes a mistake the control of the airplane passes out of his hands. Gradually he becomes more and more adept at guiding the big bird through the air, and can get along nicely without any interference or correction. At each lesson he has mastered some new problem. He knows how to leave the earth at the proper angle after the first short run over the ground, and how to come down again, how to turn in the air, when to cut off the power in alighting and when to apply the brakes. He learns to listen for the rhythmic sound of the engine and to know when anything has gone wrong with it. By far the most difficult of his problems is the art of landing. As we have already seen the speed of an airplane cannot be reduced below a certain danger line if its wings are to continue to support it in the air. This danger line varies with different types of airplanes, but in all of them the engine must be kept running at a fairly high speed or the whole structure will come crashing to the earth. To bring an airplane to earth while it is traveling at a speed of 75 miles an hour is no mean accomplishment. It must not bump down heavily upon the ground, or its landing chassis will be broken, even if no more serious accident occurs. It must settle slowly until its wheels just touch, while all the time it is moving forward at the rate of a fast express train. This is an art that requires infinite practise to acquire, but it is one of the most important feats the student airman has to learn. However, the long wished-for day finally arrives when he can be trusted to go aloft by himself. Carefully he goes over every inch of his machine, to be sure it is in A-1 condition. He inspects the engine and tests every strut and wire, then, satisfied that it is in prime working order, he climbs into his seat. That is one of the most thrilling moments connected with his aviation training. In all other flights he has known that the errors he might make could be corrected by the trusty instructor. Now he must rely solely upon himself. With a feeling of mastery and conquest, he goes skimming into the air. He longs to prove himself. Probably he does, and not long after he receives permission to try for an aviator's certificate. This is the certificate issued by the Aero Club of America; it does not make him a full-fledged military aviator, but it marks the completion of the first stage of his progress toward the coveted goal. In order to acquire the aviator's certificate, the candidate must accomplish two long distance flights and one altitude flight; he must be able to cut figures of eight and to land without the slightest injury to his machine. In other words he must prove to the satisfaction of his examiners that he is able to handle an airplane skilfully, barring of course any fancy exploits in the air. He now launches on his advanced course of training. This will require at least three months of hard work, and during that time he must learn to fly a number of different types of machines which are used in military aviation. In the meantime he may perhaps go up for examination to acquire the much-coveted "wings." But do not imagine that _they_ mark the end of his education. With the aviator it is very much as with the schoolboy: when he finishes one grade or stage of his progress he passes on to a still more difficult. The man who has acquired "wings" is not immune from the most trying daily routine of studies, which include the ever important map-reading, photography, aerial gunnery and what-not. Finally, however, there does come a day when the army aviator may be said to pass out of the elementary school of classes and instructors into the broader school of experience. Many young American aviators who served during the War can look back upon such a day with a thrill. They had then their hardest lessons to learn. The map-reading, the gunnery, the trying and tedious curriculum of the aviation school become suddenly vital issues, and the facts which were learned in the classroom have to be mastered anew by _living them_ in the air. The experience of one young airman on his first real assignment goes to show how the problems which seemed so easy of solution on the ground become unexpectedly difficult when the flyer is face to face with them for the first time up there above the clouds. Fresh from his course of training, he had been ordered to take an airplane from one government hangar to another which was close up behind the front lines. He knew his "map-reading" pretty well, but he had never made a long cross-country flight before and the ground was unfamiliar. Somewhere near his destination he made a false turn, and the first intimation that reached him of the fact that he was off his course was the appearance below him of white puffs of smoke--"cream puffs" as the airmen have jokingly nicknamed them. He realized with a start that he was over the enemy's lines and was being fired at. Without losing any time he turned his face toward home, and this time he succeeded in spotting the lost hangar and making a safe landing. But he had learned a little lesson in following his map which no instructor could have taught him half so well. [Illustration: _Copyright Underwood and Underwood_ A PHOTOGRAPH MADE TEN THOUSAND FEET IN THE AIR, SHOWING MACHINES IN "V" FORMATION AT BOMBING PRACTICE] There are many lessons like that which the airman who is new at the game must master. Gradually he becomes more and more expert and more and more self-reliant. Then, if he is of the stuff that heroes are made of, perhaps he may distinguish himself by his daring accomplishments in the air. The more daring and successful he appears to be, the more certain it is that he has covered that long road of careful preparation with exacting thoroughness. [Illustration: _Copyright International Film Service, Inc._ A GROUP OF DE HAVILLAND PLANES AT BOLLING FIELD NEAR WASHINGTON] CHAPTER XI THE FUTURE STORY OF THE AIR Since the days when the first man ascended into the clouds in a Montgolfier fire balloon, and since the days when the Wright brothers tried their first gliding experiments and proved that men might hope to soar with wings into the sky, many glorious chapters have been written in the story of the air. Surely the most inspiring and significant achievement in aerial progress is the great trans-Atlantic flight made in the latter part of May, 1919, by a flying boat of the U.S. Navy. A force of fliers in three airships under Commander Towers attempted the flight from New York to Lisbon by way of Halifax and the Azores, in three "legs" or continuous flights, but on account of disastrous weather conditions, only one of these planes, the NC-4, under Lieutenant-Commander A. C. Read completed the trip successfully. The enthusiasm of the entire world was fired by this feat and it is difficult to estimate fully its epochal significance. Simultaneous with this flight and even more daring in plan, was the attempt by an Englishman, Harry Hawker, to fly direct from St. Johns, Newfoundland, to England in a Sopwith biplane. Through an imperfect action of the water pump of his machine Hawker was forced to descend and was rescued twelve hundred miles at sea by a Danish vessel. However, the highest honor is due to this man of the air who embarked on so brave an adventure. The next trans-Atlantic flight was made about a month after the NC-4 had blazed the air route across the ocean. This was a non-stop, record-breaking trip of Capt. John Alcock and Lieut. Arthur W. Brown--an American--in the British Vickers-Vimy land plane from St John's, Newfoundland, to Clifden on the Irish coast. These daring pilots made the distance of 1900 miles in sixteen hours--an average speed of 119 miles an hour. Although these achievements in heavier-than-air machines were of far-reaching importance, they did not fully solve the problem of trans-Atlantic air passage. It remained for the great dirigible experiment in July to demonstrate that in all probability the lighter-than-air craft will prove more effective for this hazardous game with the elements. On July 2 the British naval dirigible, R-34, left East Fortune, Scotland, with thirty-one men on board under command of Major G. H. Scott, and made the journey of 3200 sea miles, by way of Newfoundland and Nova Scotia, to Mineola, Long Island, in 108 hours. The fact that weather conditions during this trip were very unfavorable adds to the value of the accomplishment. The return trip was made a few days later in 75 hours. The R-34 is indeed a mammoth of the air. At the time of its flight it was the largest aircraft in the world, having a length of 650 feet and a diameter of 78 feet. It has five cars connected by a deck below the rigid bag and is propelled by five engines of 250 H.P. each. Its maximum speed is about sixty miles an hour. The year following the Great War will go down in history as a marvelous period in aeronautic achievement. The Atlantic was for the first time crossed by aircraft and within ten weeks of its first accomplishment two trans-Atlantic flights were made, three widely differing types of aircraft being represented. As a matter of fact we have but begun to explore the possibilities of aerial flight. During the last few years we have been thinking of the airplane solely as an instrument of war, and for that purpose we have bent our entire energies to developing it. When all the wealth of skill we have acquired during strenuous war times is turned to solving the problem of making the airplane useful in times of peace, there will be new and fascinating chapters to relate. The war has done a lot for the airplane. It has raised up a host of aircraft factories in all the large countries, with thousands of skilled workers. It has given us a splendid force of trained pilots and mechanics. It has resulted in standardized airplane parts, instead of the endless confusion of designs and makes that existed a few years ago. And instead of the old haphazard methods of production it has made the building of an airplane an exact science. People used to be afraid of the airplane and it seemed a long road to travel to the time when it would play any important rôle in everyday commerce or travel. The war has resulted in making the airplane _safe_,--so safe that it is apt to win the confidence of the most timid. Yet the airplanes that we saw and read of so frequently in war time are not likely to be those which will prove the most popular and useful in the days to come. In war one of the great aims was for _speed_. Now we can afford to sacrifice some speed to greater carrying capacity. The swift tractor biplane may possibly give way to the slower biplane of the pusher type, which has greater stability. The big triplanes, such as the Russian Sikorsky and the Italian Caproni will come into their own, and yet bigger triplanes will be built, able to carry passengers and freight on long journeys over land and sea. The three surfaces of the triplane give it great lifting powers, and on this account it will be a favorite where long trips and heavy cargoes are to be reckoned with. We may expect in the near future to see huge air-going liners of this type, fitted out with promenade decks and staterooms, and with all the conveniences of modern travel. There is a strong probability that the airship, rather than the airplane, may prove to be the great aerial liner of to-morrow. The large airship of the Zeppelin type, traveling at greater speed than the fastest express train, and carrying a large number of passengers and a heavy cargo, is apt before long to become the deadly rival of the steamship. A voyage across the Atlantic in such an airship would be far shorter, safer and pleasanter than in the finest of the ocean vessels. Gliding along smoothly far above the water, the passengers would suffer no uncomfortable seasickness, nor would they be rocked and tumbled about when a storm arose and the waves piled up and up into mountains of water on the surface of the deep. Their craft would move forward undisturbed by the turbulent seas beneath. We can imagine these fortunate individuals of a few years hence, leaning over the railing of their promenade deck as we ourselves might on a calm day at sea, and recalling the great discomforts that used to attend a trans-Atlantic voyage. It is amusing to think that our steamships of to-day will perhaps be recalled by these people of the future about as we ourselves recall the old sailing vessels that used to ply the deep a generation or so ago. The airplane, if it is to hold its own beside the airship as a large passenger vessel, will first have to overcome a number of natural handicaps. In the first place, it is not possible to go on increasing the size of the airplane indefinitely, as is practically the case with the airship. For remember that the lighter-than-air machine _floats_ in the air, and only requires its engine to drive it forward: whereas the heavier-than-air machine depends upon the speed imparted to it by its engine and propeller to keep it up in the air at all. Beyond a certain size the airplane would require engines of such enormous size and power to support it that it would be practically impossible to build and operate them. Modern invention has taught us that nothing is beyond the range of fancy, and we have seen many of the wildest dreams of yesterday fulfiled, yet it is safe to say that the airplane which would in any way approximate an ocean liner will not be built for many a year to come. In the meantime, however, we will have huge machines like the Caproni and the Sikorsky triplanes, driven by two or more motors and able to make the trans-Atlantic voyage with a number of passengers, freight and fuel for the journey. Indeed, though for purposes of long distance travel and commerce the airplane stands a chance of being superseded by the lighter-than-air machine, there are many other important missions that it can perform in the modern world. One for which it is particularly suited is that of carrying the mail. In 1911 a Curtiss airplane flew from Nassau Boulevard, Long Island to Mineola, bearing the Hon. Frank H. Hitchcock, Postmaster General of the United States, "with a mail bag on his knees." As the machine swooped gently down over the big white circle that had been painted on the Mineola field, the Postmaster-General let fall his bag. That machine was the pioneer of a system of aerial mail which will soon reach every corner of the country. During the war a mail route was inaugurated between New York and Washington. Now, with many fast machines and trained pilots freed from war duties, a system of routes which will traverse our vast territory has been laid out. It is for work such as this that the small, fast airplanes developed during the war may prove most successful. Traveling over 100 miles an hour, in a straight line from their starting point to their destination, they will be able to deliver the mail with a speed almost equal to that of the telegraph, and far in excess of anything that can be accomplished by the express train. For not only has the express train much less actual speed, but it must thread its way through winding valleys, go far out of its course in order to avoid some impassable mountain district, climb steep slopes or follow river beds in order to reach its destination. The airplane has no obstacles to overcome. Mountains, rivers, impenetrable jungles present no difficulty to it. It simply chooses its objective and flies to it, practically in a straight line. It can jump the Rocky Mountains and deliver mail to the western coast with the greatest ease. Regions like Alaska, where letters from the States took weeks or even months to be delivered, and to which the steamship routes were closed for a portion of the year, will be brought closer home when mails are arriving and leaving every few days. What use can be made of the large photographing planes that have been developed during the war to such a degree of perfection? In peace times they will have many interesting duties awaiting them. The motion picture producers will no doubt employ them very widely. Flying over our country from end to end they will bring back wonderful panoramic views. They will explore the beauties of the Yukon and show us the peaks of the Rockies in all their majestic grandeur. They will be taken to other continents and sent on photographing flights into regions that have scarcely been trod by human feet, and they will bring home to us remarkable views of jungles where wild animals roam. Pictures which the motion picture man of to-day with his camera has often risked his life to secure, the nimble photographing plane will secure with the utmost ease. And that suggests another possible rôle of the airplane in times of peace: that of exploration. As we think of Peary, pushing with his valiant party across the ice fields of the far North, struggling month after month to attain his goal, and returning to the same hard effort each time his expedition failed, we cannot help wishing for his sake that the airplane had reached its present state of development when his difficult undertaking of finding the North Pole began. Who knows but that Peary the pilot might have attained his objective many years before he did, providing of course he had had a machine of the modern type to fly in. Certainly one of the coming uses of the airplane will be that of penetrating into unknown quarters of the earth. Acting on the information which we can thus obtain we may be able to open up new stores of wealth and new territories to man. The enormous boom that has been given to aircraft production by the war ought to have at least one happy result in peace times: it should reduce the cost of the airplane. When that is brought within the means of the average prosperous citizen, we may expect to see flying become a popular sport. The man who now sets forth on a cross country pleasure trip in his automobile, will find still greater enjoyment in a cross country flight. High above the dusty country roads, he will be able to skim happily through the blue, enjoying his isolation and able to gaze out for many miles in all directions over the beautiful panorama of the earth. The plane which he pilots will no doubt be so designed as to possess unusual stability. It will to a large extent be "fool proof." Its owner will enjoy the comfortable feeling which comes from a sense of security, and at the same time will have all the delightful sensations of an adventurer in the clouds. He will find the air at high altitudes invigorating, and so he will gain in health as he never could have done by motoring over the solid earth. When men take to flying in large numbers no doubt we will have to have some sort of traffic regulations of the sky, but these will never need to be so strict as upon the ground, for the air is not a single track but a wide, limitless expanse, in which airplanes can fly in many directions and at many altitudes. There will never be any need of passing to the left of the machine ahead of you or signaling behind that you are slowing down; for ten chances to one you will never encounter another plane directly in your line of flight, and if you do it will be a simple matter to dive below or climb over him, continuing your journey in a higher stratum of air. There will probably be laws controlling flights over cities and communities, where an accident to the flier might endanger the lives below. What is likely to happen is that certain "highways" of the air will be established legally, extending in many directions over the country. In these directions the private airman will be permitted to fly for pleasure, while at certain intervals along the routes public landing grounds will be maintained. Landing is still one of the most serious problems the air pilot has to face, and it is to be hoped that the aircraft builders of the near future will help him to solve this difficulty. The reason for it, as we have already seen, is that the airplane secures its buoyancy largely as a result of its speed. Wings which are large enough to support it when flying at 150 miles an hour are too small to hold it in the air when its speed is slowed down. The machine has to be landed while still moving forward at comparatively the rate of an express train, and this forward motion can only be checked after the wheels are safely on the ground. If the engine should be stopped while the airplane is still forty or fifty feet above the ground, the wings would be unable to support it and it would come crashing to the earth. But this situation of course makes matters very difficult for the airman who has not had long experience in landing his machine. He must come down on a small landing field and bring his plane to a full stop before he has crashed into the other machines which perhaps are standing about. His difficulty is added to by the fact that his propeller only works efficiently at the full speed for which it was designed. When he slows down in the air preparatory to landing, it may "slip" backward through the air, instead of driving his airplane forward at the rate necessary to support its weight. In that case he is in danger of going into a spin, from which he may not have time to recover. For these reasons it is to be hoped that the airplane of the future will have some form of telescoping wings and of variable pitch propeller. While these improvements in construction have not been worked out practically at the present moment, there is every reason to believe that they may be before long. But whatever structural difficulties have yet to be overcome in connection with the airplane, certain it is that the big birds which we saw so often in the sky during the war, are going to be yet numerous in peace times. As for the purely military machines, let us hope that their work is over, and that they may never be called on to fight another battle in the air. Yet if other wars should come, it is certain that they would play a still more tremendous rôle than they have in the present struggle. We can imagine the war of the future being fought almost entirely above the clouds. The one great contest would be for victory in the air, since the nation which succeeded in driving its enemy from the sky would have complete control of the situation on the ground. All nations will continue to increase their aerial battalions until they possess formidable fleets, and it will be these, rather than armies or navies that will go forth to settle future disputes. It is largely to the aerial supremacy of the Allies that we have to give the credit for the winning of the present war against the Hun, and it will be by maintaining their aerial supremacy that the great nations which have taken their stand for justice and humanity will succeed in enforcing the reign of Right in the world. Thus we see man's dream of the conquest of the air become a noble thing, while the frail-winged birds his imagination pictured to him throughout so many centuries stand ready to bear him onward and upward to still greater achievements in his struggle to make the world a better and cleaner place in which to live. READING LIST For those who desire a wider knowledge of the history, theory, construction and operation of aircraft than this book is intended to supply, the following reading list may prove suggestive and helpful. The older publications on this list have been found valuable from an historical viewpoint; while the more recent ones treat from many angles the rapidly advancing science of aviation. ABBOT, W. J., Aircraft and Submarines (1918) ALEXANDER, J. H., Model Balloons and Flying Machines (1910) "AVION," Aeroplanes and Aero Engines (1918) BARBER, HORATIO, The Aeroplane Speaks (1917) BARNWELL, F. S., Aeroplane Design (1917) BERGET, A., The Conquest of the Air (1911) BERRY, W. H., Aircraft in War and Commerce (1918) BRUCE, E. H. S., Aircraft in War (1914) CAVANAGH, GEORGE A., Model Aeroplanes and Their Motors (1916) CHATLEY, HERBERT, Principles and Design of Aeroplanes (1912) CURTISS, G. H., and POST, A., Curtiss Aviation Book (1912) CORBIN, T. W., Aircraft, Aeroplanes and Airships (1914) COLLINS, A. FREDERICK, The Boy's Airplane Book (1919) COLLINS, A. FREDERICK, How to Fly (1917) COLVIN, F. H., Aircraft Mechanic's Handbook (1918) DOMMETT, W. E., Aeroplanes and Airships (1916) FALES, E. N., Learning to Fly in the U. S. Army (1917) FERRIS, R., How it Flies (1910) GRAHAME-WHITE, C., and HARPER, H., Heroes of the Air (1912) GRAHAME-WHITE, C., and HARPER, H., Learning to Fly (1916) GRAHAME-WHITE, C., The Story of the Aeroplane (1911) GRAMONT, A. A. DE, Aviator's Elementary Handbook (1918) HAYWARD, CHAS. B., Building and Flying an Aeroplane (1918) HEARNE, R. P., Zeppelins and Super-Zeppelins (1916) HEARNE, R. P., Airships in Peace and War (1910) HILDEBRAND, A. L. H., Airships Past and Present (1908) JANE'S FIGHTING SHIPS, (An Annual) JUDGE, A. W., Design of Aeroplanes (1916) LANCHESTER, F. W., Aircraft in Warfare (1916) LILIENTHAL, O., Bird Flights as the Basis of Aviation (1917) LOENING, G. C., Military Aeroplanes (1916) MCCONNELL, JAMES R., Flying for France (1917) MCMINNIES, W. G., Practical Flying (1918) MAXIM, H. S., Artificial and Natural Flight (1908) MIDDLETON, E. C., The Way of the Air (1917) MIDDLETON, E. C., Glorious Exploits of the Air (1918) MIDDLETON, E. C., Airfare of Today and the Future (1918) MUNDAY, ALBERT H., The Eyes of the Army and Navy (1917) ORCY, L. D', Editor and Comp., Airship Manual (1917) PAGE, CAPT. VICTOR WILFRED, The A-B-C of Aviation (1918) PEARY, R. E., Command of the Air (Speech delivered before the American Academy of Political and Social Science) (1917) RATHBUN, JOHN B., Aeroplane Construction and Operation (1918) ROBSON, W. A., Aircraft in War and Peace (1916) ROTH, C. W., Short Course in the Theory and Operation of the Free Balloon (1918) ROUSTAM-BEK, B., Aerial Russia (1916) SIMMONDS, R., All About Aircraft (1915) STOUT, WM. B., Acquiring Wings (1917) TALBOT, F. A., Aeroplanes and Dirigibles of War (1915) THURSTON, A. B., Elementary Aeronautics (1911) TURNER, C. C., Aircraft of Today (1917) TURNER, C. C., Marvels of Aviation (1916) VERRILL, A. W., Harper's Aircraft Book (1913) WALKER, S. F., Aviation, Its Principles, Its Present and Future (1912) WALKER, F., All About Zeppelins and Other Enemy Aircraft (1915) WIDMER, EMIL J., Military Observation Balloons (1917) WOOD, WALTER, Thrilling Deeds of British Airmen (1918) WINCHESTER, C., Flying Men and Their Machines (1916) WOODHOUSE, HENRY, A Textbook of Military Aeronautics (1918) INDEX Accidents: airplane, 115 balloon, 13, 32, 54 gliding, 84, 85 Aerial Experiment Association, 107 Aero Club of America, 241 A. E. G. airplane, 200, 203 A. G. O. airplane, 200, 203 Ailerons, 13, 94, 98, 111, 113 Airplane: A. E. G., 200, 203 A. G. O., 200, 203 Albatros, 195, 203 Antoinette, 104, 105, 109, 110, 113, 119 Aviatik, 196, 203 Avro, 181, 182 battle planes, 128-140, 177, 178, 192-196 Blériot, 104, 105, 110, 113 bombing planes, 128-149, 180-188, 197-204 Breguet, 114, 181 Breguet-Michelin, 179 Bristol Scout, 175 Caproni, 183-185 Caudron, 178, 182 chassis, 111, 165-167 Curtiss, 108, 173, 174, 187, 249 De Havilland, 175, 194 _Demoiselle_, 114 Dorand, 181 drift, 97 early experiments, 77-90 engines (see _engine_) Farman, 108, 110, 112, 116, 178, 181 first principles of, 91-98 first real, 89 flight records (see _records_) Fokker, 172, 192-194, 203 Friedrichshafen, 199 Gotha, 197-199, 203 Halberstadt, 196, 203 Handley-Page, 181, 182 head resistance, 96, 151, 160 _June Bug_, 107 _Langley_, 182 Letord, 181 L. V. W., 203 making of, 223-231 (also see _fabrics_) Moineau, 179, 181 Morane, 119, 192 _NC-4_, 244 Nieuport, 121, 171, 211 nomenclature, 94 Pfalz, 203 reconnaissance planes, 128-149, 177-180 _Red Wing_, 107 Roland, 203 Rumpler, 203 Santos-Dumont's, 100, 114 Sikorsky, 125-127, 187 Sopwith, 175, 181, 185, 186, 244 Spad, 173 starting and landing problems, 165-167, 240 Taube, 191 Vickers, Scout, 175 Vickers-Vimy, 245 Voisin, 102, 103, 110, 112, 178, 182 Voisin-Peugeot, 179, 181 _White Wing_, 107 wings (see _wings_) Wright (see _Wright_) Albatros airplane, 195, 203 Alcock, Capt. John, 245 Annonay, 3, 4 Antoinette airplane, 104, 105, 109, 110, 113, 119 Archimedes' law of gravity, 14 Argus engine, 126 Arlandes, Marquis d', 7, 8 Ascents, early balloon, 3, 7-12, 20-23, 26, 27, 49 Astra dirigible, 73-74 Astra-Torres dirigible, 73-74 Aviatik airplane, 196, 203 Aviator, training of an, 232-243 Avro airplane, 181, 182 Baker, Secretary of War, 201 Baldwin, Capt. Thomas S., 65, 106 Ball, Capt. Albert, 215, 219, 220 Balloon, dirigible: Astra, 73, 74 Astra-Torres, 73, 74 Blimps, 70 car suspension, 72, 73 demi-semi-rigid, 67 development of, 47-74 first, 51 first military, 52 first U. S. Army, 65 _La France_, 53 _Nulli Secundus_, 64, 65, 68 _Patrie_, 63 _Pax_, 58 _R-34_, 245 rigid and non-rigid, 66, 67 semi-rigid, 67 _S. M. S. Zeppelin I_, 66 Speiss, 74 trans-Atlantic flight, 245 use in World War, 68-74 _Ville de Paris_, 63 Zeppelins, 55, 56, 62, 65-68, 123 Zodiacs, 72 Balloon, passive: basket of, 19 captive, 36-44 car of, 19, 50 car lines of, 18 Channel flights, 12, 22-24 _Conqueror_, 27 drachen, 36-44 early ascents of, 3-27, 49 fabrics of (see _fabrics_) first, 3 first use of, in war, 25, 26 gases used for (see _gases_) grapnel of, 19 hoop of, 18 kite, 19, 36-44 neck of, 18 net of, 18 observation, 36-44 principles of, 14-19 ripping panel of, 18 races, 26 sausage, 19, 36-44 trail rope of, 18 use of, in Great War, 36-44 Ballonet, steering, 38 Ballooning: early, 3-27 in Boer War, 26 in Civil War, 25 in Great War, 36-44 Basket, balloon, 19 Battle planes, 128-149, 177-178, 192-196 Baumgarten, 54 Bell, Alexander Graham, 106 Bennett, Gordon, 26, 108 Bishop, Major William A., 205, 214 Blanchard, 12, 13, 29 Blériot, 104, 105, 108, 115 Blimps, 70-72 Bliss, General Tasker H., 201 Boelke, Captain, 194, 219 Boer War, balloons in, 26 Bombing planes, 128-149, 180-188, 197-204 Bonnel, Captain, 220 Breguet airplane, 114, 121, 122, 123, 181 Breguet-Michelin airplane, 179 Bristol Scout airplane, 175 Brown, Lieut. Arthur W., 245 Cacquot, Captain, 43 Caproni airplane, 183, 184, 185 Car, balloon, 19, 50, 72 Car lines, balloon, 18 Carlstrom, Victor, 174 Caudron airplane, 178, 182 Cavallo, 9 Cayley, Sir George, 80 Certificate, aviator's, 241 "Chamber of Horrors," 234 Channel flights: first airplane, 104 first balloon, 12, 22-24 Chanute, 86 Chapman, Victor, 216 Chaput, Lieut. Jean, 214 Charles, 9 Chartres, Duke de, 49 Chassis: first, 111 problem of, 165-167 Circuit of Britain prize, 120 Civil War, balloons in, 25 Clement-Bayard, 74 Clerget engine, 187 Cocking, 31 Conneau, Lieutenant, 120 _Conqueror_, 27 Curtiss airplane, 108, 173, 174, 187, 249 Curtiss Baby Speed Scout, 174 Curtiss, Glenn H., 65, 106-108, 119 Curtiss triplane, 173 _Daily Mail_, London, prizes, 104, 115, 120 De Havilland airplane, 175, 194 _Demoiselle_, 114 Deutsch, 57, 63 "Dope," 164, 227 Dorand airplane, 181 Douglas, Archibald, 37 Drachen balloon, 36-44 Drift, airplane, 97 Dubonnet, Emile, 41 Eiffel Tower, flight around, 57, 115 Engine: Argus, 126 Clerget, 187 Curtiss, 71 development and principles of airplane, 153-169 Fiat, 183 first balloon, 51 Gnome, 111, 121, 154, 159 Liberty, 168, 182 Rolls-Royce, 182 Wright's, 89, 153 Esnault-Pelterie, 114 Fabrics: calico, 60, 61 cotton, 18, 164 linen, 9 oil silk, 11 rubber, 61, 63 Farman airplane, 108, 110, 112, 116, 178, 181 Farman, Henry, 102, 103, 110-112, 115, 123, 154 Fiat motor, 183 Field of Mars, 10 Fokker airplane, 172, 192-194, 203 Fonck, René, 212-214 Franklin, Benjamin, 11 Friedrichshafen airplane, 199 Fullard, Capt. Philip F., 215 Fuselage, development of, 122, 165-166 Garnerin, André, 30 Gases: coal, 16 hydrogen, 9, 21 Genet, Edmond, 218 Giffard, 50 Gliders, 81-88, 100 Gnome engine, 111, 121, 154, 159 Goertz range finder, 147 Goodyear Tire and Rubber Co., 43 Gotha airplane, 197-199, 203 Grahame-White, Claude, 116 Grapnel, balloon, 19 _Great Nassau_, 22 Green, Charles, 22, 31 Gross, Major von, 66 Guffroy, 114 Gun-tunnel Gotha, 197-199 Guynemer, Georges, 137, 172, 205-214 Haenlein, Paul, 52 Halberstadt airplane, 196, 203 Handley-Page airplane, 181, 182 Hargrave, 85 Hat-in-the-Ring Squadron, 221 Hawker, Harry, 244 Head resistance, airplane, 96, 151, 160 Hitchcock, Hon. Frank H., 249 Hoop, balloon, 18 _Hopper_, 125 Immelmann, 176, 194, 215, 219 Jeffries, Dr., 12 Jouillot, 60 _June Bug_, 107 Juvisy meeting, 115 Kite balloon, 19, 36-44 Kites: principles of, 79, 91 Lilienthal's, 81, 86 Krebs, 53 Kuparanto, R. Jordarki, 30 Lafayette Escadrille, 172, 216, 217 Lahm, Lieut. Frank P., 26 Lambert, Comte de, 108, 115 Landing problems, 165-167, 240 _Langley_, 182 Latham, Hubert, 104, 108, 109 Lebaudy Brothers, 60-67 Lefevre, 108 Letord airplane, 181 Liberty motor, 168, 182 Lilienthal, Otto, 81-85, 92 Little, Robert A., 215 Lôme, Dupuy de, 52 Loubet, President, 58 Lufbery, Major, 205, 216, 217 Lunardi, Vincent, 12, 20-22 L. V. W. airplane, 203 Malone, Lieut. John J., 215 Materials, airplane, problem of, 163, 164 McCudden, Capt. James, 205, 215 McCurdy, J. A. D., 106 Meusnier, General, 49 Michelin cup, 115 Moineau airplane, 179, 181 Monoplane, principles of, 150-151 Montgolfier Brothers, 3-11 Morane airplane, 119, 192 Moret, 21 Motor (see _engine_) _NC-4_, 244 Neck, balloon, 18 Net balloon, 18 Nieuport airplane, 121, 171, 211 Nomenclature of airplane, 94 Normand, Le, 29 _Nulli Secundus_, 64, 65, 68 Parachute flares, 34 Parachutes, 28-35, 42 Paulhan, 108, 116 Paris, bombing raid on (1918), 201 Parseval, Major von, 37, 66 _Patrie_, 63 _Pax_, 58 Pelcher, Percy S., 85 Pershing, General John, 218 Pfalz airplane, 203 Pola, bombing raid on, 184 Pollock, C. F., 23 Pourpe, Marc, 216 Price, Norman, 216 Propeller, principle of, 161-163 Raids, famous bombing: Paris, 201 Pola, 184 Read, Lieut.-Com. A. C., 244 Reconnaissance planes, 128-149, 177-180 Record airplane flights: altitude, 116, 168 channel, 104 distance, 101, 115, 116, 119, 154 speed, 108, 119, 121 trans-Atlantic, 244 _Red Wing_, 107 Renard, 53 Rheims meetings, 107, 109, 119, 121, 154 Richthofen, Baron von, 194, 210, 212, 215, 220-222 Rickenbacker, Capt. Eddie, 218-220 Ripping panel, balloon, 18 Roberts Brothers, 9, 49 Rockwell, Kiffen, 216 Roland airplane, 203 Rolls-Royce engine, 182 Rosevear, Stanley, 215 Rozier, Pilat de, 6, 13 Rumpler airplane, 203 Salomone, Major, 185 Santos-Dumont, 55-59, 99-102, 114 Sausage balloon, 19, 36-44 Schaeck, Colonel, 27 Schwartz, David, 54 _Scientific American_ trophy, 107 Scott, Major G. H., 245 Selfridge, Lieut. Thomas, 106 Severo, 58 Sigsfeld, Captain von, 37 Sikorsky, I. I., 125, 126, 127, 187 Sopwith airplane, 175, 181, 185, 186, 244 Spad airplane, 173 Speiss dirigible, 74 Steering ballonet, 38 _Storks_, the, 172, 210 Taube airplane, 191 Templer, Colonel, 64, 65 Tissandier, Gaston and Albert, 53, 108 Towers, Commander, 244 Trail rope, balloon, 18 Training of an aviator, 232-243 Trans-Atlantic flights, 244 Triplane, development of, 148-151 Vickers Scout airplane, 175 Vickers-Vimy airplane, 245 _Ville de Paris_, 63 Vinci, Leonardi da, 79 Voisin airplane, 102, 103, 110, 112, 178, 182 Voisin Brothers, 102, 110 Voisin-Peugeot airplane, 179, 181 Wenham, 80 _White Wing_, 107 Wilcox, James, 11 Wilkinson, Allan, 215 Wings: Lilienthal's, 81-84 principles of, 81, 95, 147, 148, 149, 166, 167 Wing-warping, 88, 97 Wissemann, 212 Wölfert, 54 Wollett, Capt. Henry W., 215 _World_, New York, prize, 118 Wright, Wilbur and Orville, 86-90, 99, 101, 103, 114, 150, 151, 153 Zambeccari, Count, 11 Zeppelin, Count von, 55, 62, 65 Zeppelins, 55-56, 62, 65, 66, 68, 123 Zodiacs, 72 * * * * * Transcriber's Notes: The original spelling and minor inconsistencies in the spelling and formatting have been maintained. The table below lists all corrections applied to the original text. p vii: Santos Dumont -> Santos-Dumont p viii: A group of De Haviland -> Havilland p 6: Frenchman, Pilatre de Rozier -> Pilâtre de Rozier p 6: Pilatre de Rozier -> Pilâtre de Rozier p 13: Pilatre de Rozier -> Pilâtre de Rozier p 19: more buoyant -> buoyant. p 28: the parachute -> Is small caps: THE PARACHUTE p 31: aeronuat -> aeronaut p 33: he may find himsell -> himself p 54: took place in midair -> mid-air p 55: SANTOS DUMONT -> SANTOS-DUMONT p 64: air-bag of onefifth -> one-fifth p 65: N. Y., who far -> for p 66: with a large interval -> internal p 74: The _Lebandy_ -> _Lebaudy_ p 98: the airplane body or "fusilage." -> "fuselage." p 100: resembling a boxkite -> box-kite p 111: The over-heating -> overheating p 122: by means of it -> its p 126: In the foreward -> forward p 141: produce slightly over-lapping -> overlapping p 145: that enemy reenforcements -> reinforcements p 153: needs of air-craft -> aircraft p 175: and the _De Haviland -> Havilland p 176: downing the enemy. Immelman -> Immelmann p 179: _Bréguet-Michelin_ -> _Breguet-Michelin_ p 181: the _Bréguet_ -> _Breguet_ p 194: British _DeHaviland_ -> _De Havilland_ p 206: in the town of Compiegne -> Compiègne p 206: student in the École Polytechnic -> Polytechnique p 206: 1914, came the the news -> the news p 219: the early days Immelman -> Immelmann p 219: and fighting. Immelman's -> Immelmann's p 219: from that of Immelman -> Immelmann p 236: and a dizzy "sea-sickness" -> "seasickness" p 238: goes taxi-ing -> taxiing p 244: A GROUP OF DE HAVILAND -> HAVILLAND p 251: picture man of today -> to-day p 257: Airships in Peace and War -> War (1910) P 259: balloon, 13, 32, 54, 54 -> balloon, 13, 32, 54 p 259: A. G. O. -> A. G. O., p 259: De Haviland -> Havilland p 259: engines (see _engines_) -> _engine_ p 261: De Haviland -> Havilland p 261: Esnault-Pelteric -> Pelterie p 261: Fullard, Capt. Phillip F. -> Fullard, Capt. Philip F. p 262: Immelman -> Immelmann p 263: Rozier, Pilat de -> Rozier, Pilâtre de p 264: Wollet -> Wollett 
29718	----	The Google Books Library Project (http://books.google.com/), from which additional text and images were obtained This Project Gutenberg edition of The Automobile Storage Battery--Its Care And Repair, by O. A. Witte, was prepared by George Davis, based upon the etext originally produced by Mark Posey, to whom we extend a huge "Thank You"; thanks also to Richard Allain, who produced the scans from which Posey worked, as well as to the Google Books Library Project (http://books.google.com/), from which additional text and images were obtained. ======================================================================== THE AUTOMOBILE STORAGE BATTERY ITS CARE AND REPAIR ------------------------------------------------------------------------ RADIO BATTERIES, FARM LIGHTING BATTERIES ======================================================================== A practical book for the repairman. Gives in nontechnical language, the theory, construction, operation, manufacture, maintenance, and repair of the lead-acid battery used on the automobile. Describes at length all subjects which help the repairman build up a successful battery repair business. Also contains sections on radio and farm lighting batteries. BY O. A. WITTE Chief Engineer, American Bureau of Engineering, Inc. ======================================================================== Third Edition Completely Revised and Enlarged Fourth Impression Published 1922 by THE AMERICAN BUREAU OF ENGINEERING, INC. CHICAGO, ILLINOIS, U. S. A. Copyright, 1918, 1919, 1920, and 1922, by American Bureau of Engineering, Inc. All Rights Reserved. ======================================================================== Entered at Stationers' Hall, London, England. First Impression April, 1918. Second Impression December, 1919. Third Impression October, 1920. Fourth Impression September, 1922. ======================================================================== Preface ======= Many books have been written on Storage Batteries used in stationary work, as in electric power stations. The storage battery, as used on the modern gasoline car, however, is subjected to service which is radically different from that of the battery in stationary work. It is true that the chemical actions are the same in all lead-acid storage batteries, but the design, construction, and operation of the starting and lighting battery, the radio battery, and the farm lighting battery are unique, and require a special description. Many books have been written on Storage Batteries used in stationary work, as in electric power stations. The storage battery, as used on the modern gasoline car, however, is subjected to service which is radically different from that of the battery in stationary work. It is true that the chemical actions are the same in all lead-acid storage batteries, but the design, construction, and operation of the starting and lighting battery, the radio battery, and the farm lighting battery are unique, and require a special description. This book therefore refers only to the lead-acid type of starting and lighting battery used on the modern gasoline Automobile, the batteries used with Radio sets, and the batteries used with Farm Lighting Plants. It is divided into two sections. The first section covers the theory, design, operating conditions, and care of the battery. The second section will be especially valuable to the battery repairman. All the instructions given have been in actual use for years, and represent the accumulated experiences of the most up-to-date battery repair shops in the United States. The first edition of this book met with a most pleasing reception from both repairmen and battery manufacturers. It was written to fill the need for a complete treatise on the Automobile Storage Battery for the use of battery repairmen. The rapid sale of the book, and the letters of appreciation from those who read it, proved that such a need existed. The automobile battery business is a growing one, and one in which new designs and processes are continually developed, and in preparing the second and third editions, this has been kept in mind. Some of the chapters have been entirely rewritten, and new chapters have been added to bring the text up-to-date. Old methods have been discarded, and new ones described. A section on Farm lighting Batteries has been added, as the automobile battery man should familiarize himself with such batteries, and be able to repair them. A section on Radio batteries has also been added. Special thanks are due those who offered their cooperation in the preparation and revision of the book. Mr. George M. Howard of the Electric Storage Battery Co., and Mr. C. L. Merrill of the U. S. Light & Heat Corporation very kindly gave many helpful suggestions. They also prepared special articles which have been incorporated in the book. Mr. Henry E. Peers consulted with the author and gave much valuable assistance. Mr. Lawrence Pearson of the Philadelphia Battery Co., Mr. F. S. Armstrong of the Vesta Accumulator Co., Messrs. P. L. Rittenhouse, E. C. Hicks and W. C. Brooks of the Prest-O-Lite Co., Mr. D. M. Simpson of the General Lead Batteries Co., Mr. R. D. Mowray and Mr. C. R. Story of the Universal Battery Co., Mr. H. A. Harvey of the U. S. Light and Heat Corporation, Mr. E. B. Welsh of the Westinghouse Union Battery Co., Mr. S. E. Baldwin of the Willard Storage Battery Co., Mr. H. H. Ketcham of the United Y. M. C. A. Schools, and Messrs. Guttenberger and Steger of the American Eveready Works also rendered much valuable assistance. The Chapter on Business Methods was prepared by Mr. G. W. Hafner. O. A. WITTE, Chief Engineer, American Bureau of Engineering, Inc. September, 1922 ======================================================================== Contents -------- 1. INTRODUCTORY Gasoline and electricity have made possible the modern automobile. Steps in development of electrical system of automobile. Sources of electricity on the automobile. 2. BATTERIES IN GENERAL The Simple Battery, or Voltaic Cell. Chemical Actions which Cause a Cell to Produce Electricity. Difference between Primary and Secondary, or Storage Cells. A Storage Battery Does Not "Store" Electricity. Parts Required to Make a Storage Battery. 3. MANUFACTURE OF STORAGE BATTERIES Principal Parts of a "Starting and Lighting" Battery. Types of Plates Used. Molding the Plate Grids. Trimming the Grids. Mixing Pastes. Applying Pastes to the Plate Grids. Hardening the Paste. Forming the Plates. Types of Separators. Manufacture of Separators. Manufacture of Electrolyte. Composition and Manufacture of Jars. Types of Cell Covers. Single and Double Covers. Covers Using Sealing Compound Around the Cell Posts. Covers Using Lead Bushings Around the Cell Posts. The Prest-O-Lite Peened Post Seal. Batteries Using Sealing Nuts Around Cell Posts. Construction of Vent Tubes. Exide and U. S. L. Vent Tube Design. Vent Plugs, or Caps. Manufacture of the Battery Case. Assembling and Sealing the Battery. Terminal Connections. Preparing the Completed Battery for "Wet" Shipment. Preparing the Completed Battery for "Dry" Shipment. "Home-Made" Batteries. 4. CHEMICAL CHANGES IN THE BATTERY Chemical Changes in the Battery. Plante's Work on the Storage Battery. Faure, or Pasted Plates. How Battery Produces Electricity. Chemical Actions of Charge and Discharge. Relations Between Chemical Actions and Electricity. 5. WHAT TAKES PLACE DURING DISCHARGE What a "Discharge" Consists of. Voltage Changes During Discharge. Why the Discharge Is Stopped When the Cell Voltage Has Dropped to 1.7 on Continuous Discharge. Why a Battery May Safely be Discharged to a Lower Voltage Than 1.7 Volts per Cell at High Rates of Discharge. Why Battery Voltage, Measured on "Open Circuit" is of Little Value. Changes in the Density of the Electrolyte. Why Specific Gravity Readings of the Electrolyte Show the State of Charge of a Cell. Conditions Which Make Specific Gravity Readings Unreliable. Why the Specific Gravity of the Electrolyte Falls During Discharge. Why the Discharge of a Battery Is Stopped When the Specific Gravity Has Dropped to 1.150. Chemical Changes at the Negative Plates During Discharge. Chemical Changes at the Positive Plates During Discharge. 6. WHAT TAKES PLACE DURING CHARGE Voltage Changes During Charge. Voltage of a Fully Charged Cell. Changes in the Density of the Electrolyte During Charge. Changes at the Negative Plates During Charge. Changes at the Positive Plates During Charge. 7. CAPACITY OF STORAGE BATTERIES Definition of Capacity. Factors Upon Which the Capacity of a Battery Depend. How the Area of the Plate Surfaces Affects the Capacity. How the Quantity, Arrangement, and Porosity of the Active Materials Affect the Capacity. How the Quantity and Strength of the Electrolyte Affect the Capacity. Why Too Much Electrolyte Injures a Battery. Why the Proportions of Acid and Water in the Electrolyte Must Be Correct if Specific Gravity Readings Are to Be Reliable. 8. INTERNAL RESISTANCE Effect of Internal Resistance. Resistance of Grids. Resistance of Electrolyte. Resistance of Active Materials. 9. CARE OF BATTERY ON THE CAR Care of Battery Box. How to Clean the Battery. How to Prevent Corrosion. Correct Battery Cable Length. Inspection of Battery to Determine Level of Electrolyte. How to Add Water to Replace Evaporation. When Water Should Be Added. How Electrolyte Is Lost. Danger from Adding Acid Instead of Water. Effect of Adding Too Much Water. When Specific Gravity Readings Should Be Taken. What the Various Specific Gravity Readings Indicate. Construction of a Syringe Hydrometer. How to Take Specific Gravity Readings. Why Specific Gravity Readings Should Not Be Taken Soon After Adding Water to Replace Evaporation. Troubles Indicated by Specific Gravity Readings. How to Make Sure That Sections of a Multiple-Section Battery Receive the Same Charging Current. How Temperature Affects Specific Gravity Readings. How to Make Temperature Corrections in Specific Gravity Readings. Battery Operating Temperatures. Effect of Low and High Temperatures. Troubles Indicated by High Temperatures. Damage Caused by Allowing Electrolyte to Fall Below Tops of Plates. I-low to Prevent Freezing. Care of Battery When Not in Use. "Dope" or "Patent" Electrolyte, or Battery Solutions. 10. STORAGE BATTERY TROUBLES Normal and Injurious Sulphation.-- How Injurious Sulphate Forms. Why An Idle Battery Becomes Sulphated. Why Sulphated Plates Must Be Charged at a Low Rate. How Over discharge Causes Sulphation. How Starvation Causes Sulphation. How Sulphate Results from Electrolyte Being Below Tops of Plates. How Impurities Cause Sulphation. How Sulphation Results from Adding Acid Instead of Water to Replace Evaporation. Why Adding Acid Causes Specific Gravity Readings to Be Unreliable. How Overheating Causes Sulphation. Buckling.-How Overdischarge Causes Buckling. How Continued Operation with Battery in a Discharged Condition Causes Buckling. I-low Charging at High Rates Causes Buckling, How Non-Uniform Distribution of Current Over the Plates Causes Buckling. How Defective Grid Alloy Causes Buckling. Shedding, or Loss of Active Material.-- Normal Shedding. How Excessive Charging Rate, or Overcharging Causes Shedding. How Charging Sulphated Plates at Too High a Rate Causes Shedding. How Charging Only a Portion of the Plate Causes Shedding. How Freezing Causes Shedding. How Overdischarge Causes Loose Active Material. How Buckling Causes Loose Active Material. Impurities.-- Impurities Which Cause Only Self-Discharge. Impurities Which Attack the Plates. How to Remove Impurities. Corroded Grids.-How Impurities Cause Corroded Grids. How Sulphation Causes Corroded Grids. How High Temperatures Cause Corroded Grids. How High Specific Gravity Causes Corroded Grids. How Age Causes Corroded Grids. Negatives.-- How Age and Heat Cause Granulated Negatives. Heating of Charged Negatives When Exposed to the Air. Negatives with Very Hard Active Material. Bulged Negatives. Negatives with Soft, Mushy, Active Material. Negatives with Rough Surfaces. Blistered Negatives. Positives.-- Frozen Positives. Rotten, Disintegrated Positives. Buckled Positives. Positives Which Have Lost Considerable Active Material. Positives with Soft Active Material. Positives with Hard, Shiny Active Material. Plates Which Have Been Charged in the Wrong Direction. Separator Troubles.-- Separators Not Properly Expanded Before Installation. Improperly Treated Separators. Rotten and Carbonized Separators. Separators with Clogged Pores. Separators with Edges Chiseled Off. Jar Troubles.-- Jars Damaged by Rough Handling. Jars Damaged by Battery Being Loose. Jars Damaged by Weights Placed on Top of Battery. Jars Damaged by Freezing of Electrolyte. Jars Damaged by Improperly Trimmed Plate Groups. Improperly Made Jars. Jars Damaged by Explosions in Cell. Battery Case Troubles.-- Ends of Case Bulged Out. Rotted Case. Troubles with Connectors and Terminals.--Corroded and Loose Connectors and Terminals. Electrolyte Troubles.-- Low Gravity. High Gravity. Low Level. High Level. Specific Gravity Does Not Rise During Charge. "Milky" Electrolyte. Foaming of Electrolyte. General Battery Troubles.-- Open Circuits. Battery Discharged. Dead Cells. Battery Will Not Charge. Loss of Capacity. Loss of Charge in an Idle Battery. 11. SHOP EQUIPMENT List of Tools and Equipment Required by Repair Shop. Equipment Needed for Opening Batteries. Equipment for Lead Burning. Equipment for General Work on Cell Connectors and Terminals. Equipment for Work on Cases. Tools and Equipment for General Work. Stock. Special Tools. Charging Equipment. Wiring Diagrams for Charging Resistances and Charging Circuits. Motor-Generator Sets. Suggestions on Care of Motor-Generator Sets. Operating the Charging Circuits. Constant Current Charging. Constant Potential Charging. The Tungar Rectifier. Principle of Operation of Tungar Rectifier. The Two Ampere Tungar. The One Battery Tungar. The Two. Battery Tungar. The Four Battery Tungar. The Ten Battery Tangar. The Twenty Battery Tungar. Table of Tungar Rectifiers. Installation and Operation of Tungar Rectifier. The Mercury Are Rectifier. Mechanical Rectifiers. The Stahl Rectifier. Other Charging Equipment. The Charging Bench. Illustrations and Working Drawings of Charging Benches. Illustrations and Working Drawings of Work Benches. Illustrations and Working Drawings of Sink and Wash Tanks. Lead Burning Outfits. Equipment for Handling Sealing Compound. Shelving and Racks. Working Drawings of Receiving Racks, Racks for Repaired Batteries, Racks for New Batteries, Racks for Rental Batteries, Racks for Batteries in Dry Storage, Racks for Batteries in "Wet" Storage. Working Drawings of Stock Bins. Working Drawings for Battery Steamer Bench. Description of Battery Steamer. Plate Burning Rack. Battery Terminal Tongs. Lead Burning Collars. Post Builders. Moulds for Casting Lead Parts. Link Combination Mould. Cell Connector Mould. Production Type Strap Mould. Screw Mould. Battery Turntable. Separator Cutter. Plate Press. Battery Carrier. Battery Truck. Cadmium Test Set and How to Make the Test. Paraffine Dip Pot. Wooden Boxes for Battery Parts. Acid Car boys. Drawing Acid from Carboys. Shop Layouts. Floor Grating. Seven Architects' Drawings of Shop Layouts. The Shop Floor. Shop Light. 12. GENERAL SHOP INSTRUCTIONS Complete instructions for giving a bench charge. Instructions for Burning Cell Connectors and Terminals. Burning Plates to Strap and Posts. Post Building. Extending Plate Lugs. Moulding Lead Parts. Handling and Mixing Acid. Putting New Batteries Into Service (Exide, Vesta, Philadelphia, Willard, Westinghouse, Prest-O-Lite). Installing Battery on Car. Wet and Dry Storage of Batteries. Age Codes (Exide, Philadelphia, Prest-O-Lite, Titan, U.S.L., Vesta, Westinghouse, Willard). Rental Batteries. Terminals for Rental Batteries. Marking Chapter Page Rental Batteries. Keeping a Record of Rental Batteries. General Rental Policy. Radio Batteries. Principles of Audion Bulb for Radio. Vesta Radio Batteries. Westinghouse Radio Batteries. Willard Radio Batteries. Universal Radio Batteries. Exide Radio Batteries. Philadelphia Radio Batteries. U.S.L. Radio Batteries. Prest-O-Lite Radio Batteries. "Dry" Storage Batteries. Discharge Tests. 15 Seconds High Rate Discharge Test. 20 Minutes Starting Ability Discharge Test. "Cycling" Discharge Tests. Discharge Apparatus. Packing Batteries for Shipping. Safety Precautions for the Repairman. Testing the Electrical System of a Car. Complete Rules and Instructions for Quickly Testing, Starting and Lighting System to Protect Battery. Adjusting Generator Outputs. How and When to Adjust Charging Rate. Re-insulating the Battery. Testing and Filling Service. Service Records. Illustrations of Repair Service Record Card. Rental Battery Stock Card. 13. BUSINESS METHODS Purchasing Methods. Stock Records. The Use and Abuse of Credit. Proper Bookkeeping Records. Daily Exhibit Record. Statistical and Comparative Record. 14. WHAT'S WRONG WITH THE BATTERY? "Service." Calling and Delivering Repaired Batteries. How to Diagnose Batteries That Come In. Tests on Incoming Batteries. General Inspection of Incoming Batteries. Operation Tests for Incoming Batteries. Battery Trouble Charts. Causes of Low Gravity or Low Voltage. Causes of Unequal Gravity Readings. Causes of High Gravity. Causes of Low Electrolyte. How to Determine When Battery May Be Left on Car. How to Determine When Battery Must Be Removed from Car. How to Determine When It Is Unnecessary to Open a Battery. How to Determine When Battery Must Be Opened. 15. REBUILDING THE BATTERY How to Open a Battery.-- Cleaning Outside of Battery Before Opening. Drilling and Removing Connectors and Terminals. Removing the Sealing Compound by Steam, Hot Water, Hot Putty Knife, Lead Burning Flame, and Gasoline Torch. Lifting Plates Out of Jars. Draining Plates. Removing Covers. Scraping Sealing Compound from the Covers. Scraping Sealing Compound from Inside of Jars. What Must Be Done with the Opened Battery?-- Making a Preliminary Examination of Plates. When to Put in New Plates. When Old Plates May Be Used Again. What to Do with the Separators. Find the Cause of Every Trouble. Eliminating "Shorts." Preliminary Charge After Eliminating Shorts. Washing and Pressing Negatives. Washing Positives. Burning on New Plates. Testing Jars for Cracks and Holes. Removing Defective Jars. Repairing the Case. Reassembling the Elements.-- Putting in Now Separators. Putting Elements Into Jars. Filling Jars with Electrolyte. Putting Chapter Page on the Covers. Sealing the Covers. Burning on the Connectors and Terminals. Marking the Repaired Battery. Cleaning and Painting the Case. Charging the Rebuilt Battery. Testing. 16. SPECIAL INSTRUCTIONS Exide Batteries.-- Types. Type Numbers. Methods of Holding Jars in Case. Opening Exide Batteries. Work on Plates, Separators, Jars, and Case. Putting Plates in Jars. Filling Jars with Electrolyte. Sealing Covers. Putting Cells in Case. Burning on the Cell Connectors. Charging After Repairing. Tables of Exide Batteries. U.S.L. Batteries.-- Old and New. U.S.L. Covers. Special Repair Instructions. Tables of U.S.L. Batteries. Prest-O-Lite Batteries.-- Old and New Prest-O-Lite Cover Constructions. The "Peened" Post Seal. Special Tools for Work on Prest-O-Lite Batteries. The Peening Press. Removing Covers. Rebuilding Posts. Locking, or "Peening" the Posts. Precautions in Post Locking Operations. Tables of Prest-0-Lite Batteries. Philadelphia Diamond Grid Batteries.-- Old and New Types. The Philadelphia "Rubber-Lockt" Cover Seal. Philadelphia Rubber Case Batteries. The Philadelphia Separator. Special Repair Instructions. Eveready Batteries.-- Why the Eveready Batteries Are Called "Non-Sulphating" Batteries. Description of Parts of Eveready Battery. Special Repair Instructions. Vesta Batteries.-- Old and New Vesta Isolators. The Vesta Type "D" Battery. The Vesta Type "DJ" Battery. Vesta Separators. The Vesta Post Seal. Special Repair Instructions for Old and New Isolators and Post Seal. Westinghouse Batteries.-- The Westinghouse Post Seal. Westinghouse Plates. Types of Westinghouse Batteries. Type "A" Batteries. Type "B" Batteries. Type "C" Batteries. Type "E" Batteries. Type "H" Batteries. Type "J" Batteries. Type "0" Batteries. Type "F" Batteries. Willard Batteries.-- Double and Single Cover Batteries. Batteries with Sealing Compound Post Seal. Batteries with Lead Inserts in Cover Post Holes. Batteries with Rubber Casket Post Seal. Special Repair Instructions for Work on the Different Types of Post Seal Constructions. Willard Threaded Rubber Separators. Universal Batteries.-- Types. Construction Features. Putting New Universal Batteries Into Service. Titan Batteries.-- The Titan Grid. The Titan Post Seal. 17. FARM LIGHTING BATTERIES Comparison of Operating Conditions of Farm Lighting Batteries with Automobile Batteries. Jars for Farm Lighting Batteries. Separators. Electrolyte. Charging Equipment. Relation of the Automobile Battery Man to the Farm Lighting Plant. Rules Governing the Selection of a Farm Lighting Plant. Location and Wiring of Farm Lighting Plant. Installation. Care of Plant in Service. Care of Battery. Charging Farm Lighting Batteries. Rules Governing Discharging of Farm Lighting Batteries. Troubles Found in Farm Lighting Batteries. Inspection and Tests on Farm Lighting Batteries. Description of Prest-O-Lite Farm Lighting Battery. Rebuilding Prest-O-Lite Farm Lighting Batteries. Description of Exide Farm Lighting Batteries. The Delco-Light Battery. Rebuilding and Repairing Exide Farm Lighting Batteries. Westinghouse Farm Lighting Batteries. Willard Farm Lighting Batteries. DEFINITIONS Condensed Dictionary of Words and Terms Used in Battery Work. GENERAL INDEX A VISIT TO THE FACTORY Photographs showing factory processes. BUYERS' INDEX. (Omitted.) For the Convenience of Our Readers We Have Prepared a List of Companies from Whom Battery Shop Equipment May Be Obtained. ADVERTISEMENTS (Omitted. Outdated; high bandwidth) ======================================================================== Section I --------- Working Principles, Manufacture, Maintenance, Diseases, and Remedies ======================================================================== The Automobile Storage Battery ======================================================================== CHAPTER 1. INTRODUCTORY. Gasoline and electricity have made possible the modern automobile. Each has its work to do in the operation of the car, and if either fails to perform its duties, the car cannot move. The action of the gasoline, and the mechanisms that control it are comparatively simple, and easily understood, because gasoline is something definite which we can see and feel, and which can be weighed, or measured in gallons. Electricity, on the other hand, is invisible, cannot be poured into cans or tanks, has no odor, and, therefore, nobody knows just what it is. We can only study the effects of electricity, and the wires, coils, and similar apparatus in which it is present. It is for this reason that an air of mystery surrounds electrical things, especially to the man who has not made a special study of the subject. Without electricity, there would be no gasoline engine, because gasoline itself cannot cause the engine to operate. It is only when the electrical spark explodes or "ignites" the mixture of gasoline and air which has been drawn into the engine cylinders that the engine develops power. Thus an electrical ignition system has always been an essential part of every gasoline automobile. The first step in the use of electricity on the automobile, in addition to the ignition system, consisted in the installation of an electric lighting system to replace the inconvenient oil or gas lamps which were satisfactory as far as the light they gave was concerned, but which had the disadvantage of requiring the driver to leave his seat, and light each lamp separately, often in a strong wind or rain which consumed many matches, time, and frequently spoiled his temper for the remainder of the evening. Electric lamps have none of these disadvantages. They can be controlled from the driver's seat, can be turned on or off by merely turning or pushing a switch-button, are not affected by wind or rain, do not smoke up the lenses, and do not send a stream of unpleasant odors back to the passengers. The apparatus used to supply the electricity for the lamps consisted of a generator, or a "storage" battery, or both. The generator alone had the disadvantage that the lamps could be used only while the engine was running. The battery, on the other hand, furnished light at all times, but had to be removed from the car frequently, and "charged." With both the generator and battery, the lights could be turned on whether the engine was running or not, and, furthermore, it was no longer necessary to remove the battery to "charge," or put new life into it. With a generator and storage battery, moreover, a reliable source of electricity for ignition was provided, and so we find dry batteries and magnetos being discarded in a great many automobiles and "battery ignition" systems substituted. The development of electric lighting systems increased the popularity of the automobile, but the motor car still had a great drawback-cranking. Owing to the peculiar features of a gasoline engine, it must first be put in motion by some external power before it will begin to operate under its own power. This made it necessary for the driver to "crank" the engine, or start it moving, by means of a handle attached to the engine shaft. Cranking a large engine is difficult, especially if it is cold, and often results in tired muscles, and soiled clothes and tempers. It also made it impossible for the average woman to drive a car because she did not have the strength necessary to "crank" an engine. The next step in the perfection of the automobile was naturally the development of an automatic device to crank the engine, and thus make the driving of a car a pleasure rather than a task. We find, therefore, that in 1912, "self-starters" began to be used. These were not all electrical, some used tanks of compressed air, others acetylene, and various mechanical devices, such as the spring starters. The electrical starters, however, proved their superiority immediately, and filled such a long felt want that all the various makes of automobiles now have electric starters. The present day motor car, therefore, uses gasoline for the engine only, but uses electricity for ignition, starting, lighting, for the horn, cigar lighters, hand warmers on the steering wheel, gasoline vaporizers, and even for shifting speed changing gears, and for the brakes. On any car that uses an electric lighting and starting system, there are two sources of electricity, the generator and the battery, These must furnish the power for the starting, or "cranking" motor, the ignition, the lights, the horn, and the other devices. The demands made upon the generator are comparatively light and simple, and no severe work is done by it. The battery, on the other hand is called upon to give a much more severe service, that of furnishing the power to crank the engine. It must also perform all the duties of the generator when the engine is not running, since a generator must be in motion in order to produce electricity. A generator is made of iron, copper, carbon, and insulation. These are all solid substances which can easily be built in any size or shape, and which undergo very little change as parts of the generator. The battery is made mainly of lead, lead compounds, water and sulphuric acid. Here we have liquids as well as solids, which produce electricity by changes in their composition, resulting in complicated chemical as well as electrical actions. [Fig. 1 The Battery] The battery is, because of its construction and performance, a much abused, neglected piece of apparatus which is but partly understood, even by many electrical experts, for to understand it thoroughly requires a study of chemistry as well as of electricity. Knowledge of the construction and action of a storage battery is not enough to make anyone an expert battery man. He must also know how to regulate the operating conditions so as to obtain the best service from the battery, and he must be able to make complete repairs on any battery no matter what its condition may be. ======================================================================== CHAPTER 2. BATTERIES IN GENERAL There are two ways of "generating" electricity on the car: 1. Magnetically, 2. Chemically. The first method is that used in a generator, in which wires are rotated in a "field" in which magnetic forces act. The second method is that of the battery, and the one in which we are now interested. If two unlike metals or conducting substances are placed in a liquid which causes a greater chemical change in one of the substances than in the other, an electrical pressure, or "electromotive" force is caused to exist between the two metals or conducting substances. The greater the difference in the chemical action on the substances, the greater will be the electrical pressure, and if the substances are connected together outside of the liquid by a wire or other conductor of electricity, an electric current will flow through the path or "circuit" consisting of the liquid, the two substances which are immersed in the liquid, and the external wire or conductor. As the current flows through the combination of the liquid, and the substances immersed in it, which is called a voltaic "cell," one or both of the substances undergo chemical changes which continue until one of the substances is entirely changed. These chemical changes produce the electrical pressure which causes the current to flow, and the flow will continue until one or both of the substances are changed entirely. This change due to the chemical action may result in the formation of gases, or of solid compounds. If gases are formed they escape and are lost. If solids are formed, no material is actually lost. Assuming that one of the conducting substances, or "electrodes," which are immersed in the liquid has been acted upon by the liquid, or "electrolyte," until no further chemical action can take place, our voltaic cell will no longer be capable of causing a flow of electricity. If none of the substances resulting from the original chemical action have been lost as gases, it may be possible to reverse the entire set of operations which have taken place. That is, suppose we now send a current through the cell from an outside source of electricity, in a direction opposite to that in which the current produced by the chemical action between the electrodes and electrolyte flowed. If this current now produces chemical actions between electrodes and electrolyte which are the reverse of those which occurred originally, so that finally we have the electrodes and electrolyte brought back to their original composition and condition, we have the cell just as it was before we used it for the production of an electrical pressure. The cell can now again be used as a source of electricity as long as the electrolyte acts upon the electrodes, or until it is "discharged" and incapable of any further production of electrical pressure. Sending a current through a discharged cell, so as to reverse the chemical actions which brought about the discharged conditions, is called "charging" the cell. [Fig. 2 A complete cell; Negative group; Positive group] Cells in which an electrical pressure is produced as soon as the electrodes are immersed in the electrolyte are called it "primary" Cells. In these cells it is often impossible, and always unsatisfactory to reverse the chemical action as explained above. Cells whose chemical actions are reversible are called "storage" or "secondary" cells. In the "storage" cells used today, a current must first be sent through the cell in order to cause the chemical changes which result in putting the electrodes and electrolyte, in such a condition that they will be capable of producing an electrical pressure when the chemical changes caused by the current are complete. The cell now possesses all the characteristics of a primary cell, and may be used as a source of electricity until "discharged." It may then be "charged" again, and so on, the chemical action in one case causing a flow of current, and a reversed flow of current causing reversed chemical actions. We see from the above that the "storage" battery does not "store" electricity at all, but changes chemical into electrical energy when "discharging," and changes electrical into chemical energy when "charging," the two actions being entirely reversible. The idea of "storing" electricity comes from the fact that if we send a current of electricity through the cell for a certain length of time, we can at a later time draw a current from the cell for almost the same length of time. [Fig. 3 Complete Element] Fig. 3. A complete element, consisting of a positive and negative group of plates and separators ready for placing in the hard rubber jars. Three things are therefore required in a storage cell, the liquid or "electrolyte" and two unlike substances or electrodes, through which a current of electricity can pass and which are acted upon by the electrolyte with a chemical action that is greater for one substance than the other. In the storage cell used on the automobile today for starting and lighting, the electrodes are lead and peroxide of lead, and the electrolyte is a mixture of sulphuric acid and water. The peroxide of lead electrode is the one upon which the electrolyte has the greater chemical effect, and it is called the positive or "+" electrode, because when the battery is sending a. current through an external circuit, the current flows from this electrode through the external circuit, and back to the lead electrode, which is called the negative, or electrode. When starting and lighting systems were adopted in 1912, storage batteries had been used for many years in electric power stations. These were, however, large and heavy, and many difficult problems of design had to be solved in order to produce a battery capable of performing the work of cranking the engine, and yet be portable, light, and small enough to occupy only a very limited space on the automobile. As a result of these conditions governing the design, the starting and lighting battery of today is in reality "the giant that lives in a box." The Electric Storage Battery Company estimates that one of its types of batteries, which measures only 12-5/8 inches long, 7-3/8 wide, and 9-1/8 high, and weighs only 63-1/2 pounds, can deliver enough energy to raise itself to a height of 6 miles straight up in the air. It must be able to do its work quickly at all times, and in all sorts of weather, with temperatures ranging from below 0° to 100° Fahrenheit, or even higher. The starting and lighting battery has therefore been designed to withstand severe operating conditions. Looking at such a battery on a car we see a small wooden box in which are placed three or more "cells," see Fig. 1. Each "cell" has a hard, black rubber top through which two posts of lead project. Bars of lead connect the posts of one cell to those of the next. To one of the posts of each end cell is connected a cable which leads into the car, and through which the current leaves or enters the battery. At the center of each cell is a removable rubber plug covering an opening through which communication is established with the inside of the cell for the purpose of pouring in water, removing some of the electrolyte to determine the condition of the battery, or to allow gases formed within the cell to escape. Looking down through this opening we can see the things needed to form a storage battery: the electrolyte, and the electrodes or "plates" as they are called. If we should remove the lead bars connecting one cell to another, and take off the black cover, we should find that the posts which project out of the cells are attached to the plates which are broad and flat, and separated by thin pieces of wood or rubber., If we lift out the plates we find that they are connected alternately to the two lead posts, and that the two outside ones have a gray color. If we pull the plates out from each Other, we find that the plates next to the two outside ones, and all other plates connected to the same lead post as these have a chocolate-brown color. If we remove the jar of the cell, we find that it is made of hard rubber. Pouring out the electrolyte we find several ridges which hold the plates off the bottom of the jar. The pockets formed by these ridges may contain some soft, muddy substance. Thus we have exposed all the elements of a cell, posts, plates, "separators," and electrolyte. The gray colored plates are attached to the "negative" battery post, while the chocolate-brown colored ones are connected to the "positive" battery post. Examination will show that each of the plates consists of a skeleton metallic framework which is filled with the brown or gray substances. This construction is used to decrease the weight of the battery. The gray filler material is pure lead in a condition called "spongy lead." The chocolate-brown filler substance is peroxide of lead. We have found nothing but two sets of plates--one of pure lead, the other of peroxide of lead, and the electrolyte of sulphuric acid and water. These produce the heavy current necessary to crank the engine. How this is done, and what the chemical actions within the cell are, are described in Chapter 4. ======================================================================== CHAPTER 3. MANUFACTURE OF STORAGE BATTERIES. --------------------------------- To supply the great number of batteries needed for gasoline automobiles, large companies have been formed. Each company has its special and secret processes which it will not reveal to the public. Only a few companies, however, supply batteries in any considerable quantities, the great majority of cars being supplied with batteries made by not more than five or six manufacturers. This greatly reduces the number of possible different designs in general use today. The design and dimensions of batteries vary considerably, but the general constructions are similar. The special processes of the manufacturers are of no special interest to the repairman, and only a general description will be given here. A starting and lighting battery consists of the following principal parts: 1. Plates 2. Separators 3. Electrolyte 4. Jars 5. Covers 6. Cell Connectors and Terminals 7. Case Plates Of the two general types of battery plates, Faure and Plante, the Faure, or pasted type, is universally used on automobiles. In the manufacture of pasted plates there are several steps which we shall describe in the order in which they are carried out. Casting the Grid. The grid is the skeleton of the plate. It performs the double function of supporting the mechanically weak active material and of conducting the current. It is made of a lead antimony alloy which is melted and poured into a mould. Pure lead is too soft and too easily attacked by the electrolyte, and antimony is added to give stiffness, and resistance to the action of the electrolyte in the cell. The amount of antimony used varies in different makes but probably averages 8 to 10%. The casting process requires considerable skill, the proper composition of the metal and the temperature of both metal and moulds being of great importance in securing perfect grids, which are free from blowholes, and which have a uniform structure and composition. Some manufacturers cast two grids simultaneously in each mould, the two plates being joined to each other along the bottom edge. Trimming the Grids. When the castings have cooled, they are removed from the moulds and passed to a press or trimming machine which trims off the casting gate and the rough edges. The grids are given a rigid inspection, those having shrunken or missing ribs or other defects being rejected. The grids are now ready for pasting. [Fig 4. Grid, Trimmed, and Ready for Pasting] Fig. 4 shows a grid ready for pasting. The heavy lug at one upper corner is the conducting lug, for carrying the current to the strap, Fig. 5, into which the lugs are burned when the battery is assembled. The straps are provided with posts, to which the intercell connectors and terminal connectors are attached. The vertical ribs of the grids extend through the plate, providing mechanical strength and conductivity, while the small horizontal ribs are at the surface and in staggered relation on opposite faces. Both the outside frames and the vertical ribs are reinforced near the lug, where the greatest amount of current must be carried. The rectangular arrangement of ribs, as shown in Fig. 4, is most generally used, although, there are other arrangements such as the Philadelphia "Diamond" grid in which the ribs form acute angles, giving diamond shaped openings, as shown in Fig. 6. Pastes. There are many formulas for the pastes, which are later converted into active material, and each is considered a trade secret by the manufacturer using it. The basis of all, however, is oxide of lead, either Red Lead (Pb30 4), Litharge (PbO), or a mixture of the two, made into a paste with a liquid, such as dilute sulphuric acid. The object of mixing the oxides with the liquid is to form a paste of the proper consistency for application to the grids, and at the same time introduce the proper amount of binding, or setting agent which will give porosity, and which will bind together the active material, especially in the positive plate. Red lead usually predominates in the positive paste, and litharge in the negative, as this combination requires the least energy in forming the oxides to active material. [Fig. 5 Plate Straps and Posts] The oxides of lead used in preparing the pastes which are applied to the grids are powders, and in their dry condition could not be applied to the grids, as they would fall out. Mixing them with a liquid to make a paste gives them greater coherence and enables them to be applied to the grids. Sulphuric acid puts the oxides in the desired pasty condition, but has the disadvantage of causing a chemical action to take place which changes a considerable portion of the oxides to lead sulphate, the presence of which makes the paste stiff and impossible to apply to the grids. When acid is used, it is therefore necessary to work fast after the oxides are mixed with sulphuric acid to form the paste. In addition to the lead oxides, the pastes may contain some binding material such as ammonium or magnesium sulphate, which tends to bind the particles of the active material together. The paste used for the negatives may contain lamp black to give porosity. Applying the Paste. After the oxides are mixed to a paste they are applied to the grids. This is done either by hand, or by machine In the hand pasting process, the pastes are applied from each face of the grid by means of a wooden paddle or trowel, and are smoothed off flush with the surface of the ribs of the grid. This work is done quickly in order that the pastes may not stiffen before they are applied. U. S. L. plates are pasted in a machine which applies the paste to the grid, subjecting it at the same time to a pressure which forces it thoroughly into the grid, and packs it in a dense mass. Drying the Paste. The freshly pasted plates are now allowed to dry in the air, or are dried by blowing air over them. In any case, the pastes set to a hard mass, in which condition the pastes adhere firmly to the grids. The plates may then be handled without a loss of paste from the grids. [Fig. 6 Philadelphia diamond grid] Forming. The next step is to change the paste of oxides into the active materials which make a cell operative. This is called "forming" and is really nothing but a prolonged charge, requiring several days. In some factories the plates are mounted in tanks, positive and negative plates alternating as in a cell. The positives are all connected together in one group and the negatives in another, and current passed through just as in charging a battery. In other factories the positives and negatives are formed in separate tanks against "dummy" electrodes. The passing of the current slowly changes the mixtures of lead oxide and lead sulphate, forming brown peroxide of lead (PbO2), on the positive plate and gray spongy metallic lead on the negative. The formation by the current of lead peroxide and spongy lead on the positive and negative plates respectively would take place if the composition of the two pastes were identical. The difference in the composition of the paste for positive and negative plates is for the purpose of securing the properties of porosity and physical condition best suited to each. [Fig. 7 Formed plate, ready to be burned to plate connecting strap] When the forming process is complete, the plates are washed and dried, and are then ready for use in the battery. If the grids of two plates have been cast together, as is done by some manufacturers, these are now cut apart, and the lugs cut to the proper height. The next step is to roll, or press the negatives after they are removed from the forming bath so as to bring the negative paste, which has become roughened by gassing that occurred during the forming process, flush with the surface of the ribs of the grid. A sufficient amount of sulphate is left in the plates to bind together the active material. Without this sulphate the positive paste would simply be a powder and when dry would fall out of the grids like dry dust. Fig. 7 shows a formed plate ready to be burned to the strap. Separators In batteries used both for starting and for lighting, separators made of specially treated wood are largely used. See Fig. 8. The Willard Company has adopted an insulator made of a rubber fabric pierced by thousands of cotton threads, each thread being as long as the separator is thick. The electrolyte is carried through these threads from one side of the separator to the other by capillary action, the great number of these threads insuring the rapid diffusion of electrolyte which is necessary in batteries which are subjected to the heavy discharge current required in starting. In batteries used for lighting or ignition, sheets of rubber in which numerous holes have been drilled are also used, these holes permitting diffusion to take place rapidly enough to perform the required service satisfactorily, since the currents involved are much smaller than in starting motor service. [Fig. 8] Fig 8. A Pile of Prepared Wooden Seperators Ready to be Put Between the Positive and Negative Plates to Form the Complete Element. For the wooden separators, porous wood, such as Port Orford cedar, basswood, cypress, or cedar is used. Other woods such as redwood and cherry are also used. The question is often asked "which wood makes the best separators?" This is difficult to answer because the method of treating the wood is just as important as is the kind of wood. The wood for the separators is cut into strips of the correct thickness. These strips are passed through a grooving machine which cuts the grooves in one side, leaving the other side smooth. The strips are next sawed to the correct size, and are then boiled in a warm alkaline solution for about 24 hours to neutralize any organic acid, such as acetic acid, which the wood naturally contains. Such acids would cause unsatisfactory battery action and damage to the battery. The Vesta separator, or "impregnated mat," is treated in a bath of Barium salts which form compounds with the wood and which are said to make the separators strong and acid-resisting. [Fig. 9 Philco slotted retainer] Some batteries use a double separator, one of which is the wooden separator, while the other consists of a thin sheet of hard rubber containing many fine perforations. This rubber sheet is placed between the positive plate and the wooden separator. A recent development in the use of an auxiliary rubber separator is the Philco slotted retainer which is placed between the separators and the positives in Philadelphia Diamond Grid Batteries. Some Exide batteries also use slotted rubber separators. The Philco slotted retainer consists of a thin sheet of slotted hard rubber as shown in Fig. 9. The purpose of the retainer is to hold the positive active material in place and prevent the shedding which usually occurs. The slots in the retainer are so numerous that they allow the free passage of electrolyte, but each slot is made very narrow so as to hold the active material in the plates. Electrolyte Little need be said here about the electrolyte, since a full description is given elsewhere. See page 222. Acid is received by the battery manufacturer in concentrated form. Its specific gravity is then 1.835. The acid commonly used is made by the "contact" process, in which sulphur dioxide is oxidized to sulphur trioxide, and then, with the addition of water, changed to sulphuric acid. The concentrated acid is diluted with distilled water to the proper specific gravity. Jars The jars which contain the plates, separators, and electrolyte are made of a tough, hard rubber compound. They are made either by the moulding process, or by wrapping sheets of rubber compound around metal mandrels. In either case the jar is subsequently vulcanized by careful heating at the correct temperature. The battery manufacturers do not, as a rule, make their own jars, but have them made by the rubber companies who give the jars a high voltage test to detect any flaws, holes, or cracks which would subsequently cause a leak. The jars as received at the battery maker's factory are ready for use. Across the bottom of the jar are several stiff ribs which extend up into the jar so as to provide a substantial support for the plates, and at the same time form several pockets below the plates in which the sediment resulting from shedding of active material from the plates accumulates. Covers No part of a battery is of greater importance than the hard rubber cell covers, from the viewpoint of the repairman as well as the manufacturer. The repairman is concerned chiefly with the methods of sealing the battery, and no part of his work requires greater skill than the work on the covers. The manufacturers have developed special constructions, their aims being to design the cover so as to facilitate the escape of gas which accumulates in the upper part of a cell during charge, to provide space for expansion of the electrolyte as it becomes heated, to simplify inspection and filling with pure water, to make leak proof joints between the cover and the jar and between the cover and the lead posts which project through it, and to simplify the work of making repairs. Single and Double Covers. Modern types of batteries have a single piece cover, the edges of which are made so as to form a slot or channel with the inside of the jar, into which is poured sealing compound to form a leak proof joint. This construction is illustrated. in Exide, Fig. 1.5; Vesta, Fig. 264; Philadelphia Diamond Grid, Fig. 256; U. S. L., Figs. 11 and 244; and Prest-0-Lite, Fig. 247, batteries. Exide batteries are also made with a double flange cover, in which the top of the jar fits between the two flanges. In single covers, a comparatively small amount of sealing compound is used, and repair work is greatly simplified. In the Eveready battery, Fig. 262, compound is poured over the entire cover instead of around the edges. This method requires a considerable amount of sealing compound. The use of double covers is not as common as it was some years ago. This construction makes use of two flat pieces of hard rubber. In such batteries a considerable amount of sealing compound is used. This compound is poured on top of the lower cover to seal the battery, the top cover serving to cover up the compound and brace the posts. Fig. 10 illustrates this construction. [Fig. 10 Cross-section of Gould double cover battery] Sealing Around the Posts. Much variety is shown in the methods used to secure a leak proof joint between the posts and the cover. Several methods are used. One of these uses the sealing compound to make a tight joint. Another has lead bushings which are screwed up into the cover or moulded in the cover, the bushings being burned together with the post and cell connector. Another method has a threaded post, and uses a lead alloy nut with a rubber washer to make a tight joint. Still another method forces a lead collar down over the post, and presses the cover down on a soft rubber gasket. Using Sealing Compound. Some of the batteries which use sealing compound to make a tight joint between the cover and the post have a hard rubber bushing shrunk over the post. This construction is used in Gould batteries, as shown in Fig. 10, and in the old Willard double cover batteries. The rubber bushing is grooved horizontally to increase the length of the sealing surface. [Fig. 11 U.S.L. cover] Other batteries that use sealing compound around the posts have grooves or "petticoats" cut directly in the post and have a well around the post into which the sealing compound is poured. This is the construction used in the old Philadelphia Diamond Grid battery, as shown in Fig. 254. Using Lead Bushings. U. S. L. batteries have a flanged lead bushing which is moulded directly into the cover, as shown in Fig. 11. In assembling the battery, the cover is placed over the post, and the cell connector is burned to both post and bushing. [Fig. 12 Lead bushing screwed into cover] In older type U. S. L. batteries a bushing was screwed up through the cover, and then burned to the post and cell connector. An old type Prest-O-Lite battery used a lead bushing which screwed up through the cover similarly to the U. S. L. batteries. Fig. 12 illustrates this construction. The SJWN and SJRN Willard Batteries used a lead insert. See page 424. The modern Vesta batteries use a soft rubber gasket under the cover, and force a lead collar over the post, which pushes the cover down on the gasket. The lead collar and post "freeze" together and make an acid proof joint. See page 413. The Westinghouse battery uses a three part seal consisting of a lead washer which is placed around the post, a U shaped, soft gum washer which is placed between the post and cover, and a tapered lead sleeve, which presses the washer against the post and the cover. See page 417. [Fig. 13 Cross section of old type Willard battery] The Prest-O-Lite Peened Post Seal. All Prest-O-Lite batteries designated as types WHN, RHN, BHN and JFN, have a single moulded cover which is locked directly on to the posts. This is done by forcing a solid ring of lead from a portion of the post down into a chamfer in the top of the cover. This construction is illustrated in Fig. 247. Batteries Using Sealing Nuts. The Exide batteries have threaded posts. A rubber gasket is placed under the cover on a shoulder on the post. The nut is then turned down on the post to force the cover on the gasket. This construction is illustrated in Fig. 239. The Titan battery uses a somewhat similar seal, as shown in Fig. 293. Some of the older Willard batteries have a chamfer or groove in the under, side of the cover. The posts have a ring of lead in the base which fits up into the groove in the cover to make a tight joint. This is illustrated in Fig. 13. The later Willard constructions, using a rubber gasket seal and a lead cover insert, are illustrated in Figs. 278 and 287. Filling Tube or Vent Tube Construction. Quite a number of designs have been developed in the construction of the filling or vent tube. In double covers, the tube is sometimes a separate part which is screwed into the lower cover. In other batteries using double covers, the tube is an integral part of the cover, as shown in Fig. 10. In all single covers, the tube is moulded integral with the cover. [Fig. 14a Vent hold in U.S.L. battery] Several devices have been developed to make it impossible to overfill batteries. This has been done by the U. S. L. and Exide companies on older types of batteries, their constructions being described as follows: In old U. S. L. batteries, a small auxiliary vent tube is drilled, as shown in Fig. 14. When filling to replace evaporation, this vent tube prevents overfilling. [Fig. 14b Filling U.S.L. battery] A finger is placed over the auxiliary vent tube shown in Fig. 14. The water is then poured in through the filling or vent tube. When the water reaches the bottom of the tube, the air imprisoned in the expansion chamber can no longer escape. Consequently the water can rise no higher in this chamber, but simply fills up the tube. Water is added till it reaches the top of the tube. The finger is then removed from the vent tube. This allows the air to escape from the expansion chamber. The water will therefore fall in the filling or vent tube, and rise slightly in the expansion chamber. The construction makes it impossible to overfill the battery, provided that the finger is held on the vent hole as directed. [Fig. 14c Filling U.S.L. battery (old types)] Figure 15 shows the Non-Flooding Vent and Filling Plug used in the older type Exide battery, and in the present type LXRV. The new Exide cover, which does not use the non-flooding feature, is also shown. The old construction is described as follows: [Fig. 15a Sectional view of cover in older type Exide battery. Top view of cover and filling plug, plug removed] [Fig. 15b Old and new Exide covers] From the illustrations of the vent and filling plug, it will be seen that they provide both a vented stopper (vents F, G, H), and an automatic device for the preventing of overfilling and flooding. The amount of water that can be put into the cell is limited to the exact amount needed to replace that lost by evaporation. This is accomplished by means of the hard rubber valve (A) within the cell cover and with which the top of the vent plug (E) engages, as shown in the illustrations. The action of removing the plug (E) turns this valve (A), closing the air passage (BB), and forming an air tight chamber (C) in the top of the cell. When water is poured in, it cannot rise in this air space (C) so as to completely fill the cell. As soon as the proper level is reached, the water rises in the filling tube (D) and gives a positive indication that sufficient water has been added. Should, however, the filling be continued, the excess will be pure water only, not acid. On replacing the plug (E), valve (A) is automatically turned, opening the air passages (BB), leaving the air chamber (C) available for the expansion of the solution, which occurs when the battery is working. Generally the filling or vent tube is so made that its lower end indicates the correct level of electrolyte above the plates, In adding water, the level of the electrolyte is brought up to the bottom of the filling tube. By looking down into the tube, it can be seen when the electrolyte reaches the bottom of the tube. Vent Plugs, or Caps. Vent plugs, or caps, close up the filling or vent tubes in the covers. They are made of hard rubber, and either screw into or over the tubes, or are tightened by a full or partial turn, as is done in Exide batteries. In the caps are small holes which are so arranged that gases generated within the battery may escape, but acid spray cannot pass through these holes. It is of the utmost importance that the holes in the vent caps be kept open to allow the gases to escape. Case The wooden case in which the cells are placed is usually made of kiln dried white oak or hard maple. The wood is inspected carefully, and all pieces are rejected that are weather-checked, or contain worm-holes or knots. The wood is sawed into various thicknesses, and then cut to the proper lengths and widths. The wood is passed through other machines that cut in the dovetails, put the tongue on the bottom for the joints, stamp on the part number, drill the holes for the screws or bolts holding the handles, cut the grooves for the sealing compound, etc. The several pieces are then assembled and glued together. The finishing touches are then put on, these consisting of cutting the cases to the proper heights, sandpapering the boxes, etc. The cases are then inspected and are ready to be painted. A more recent development in case construction is a one-piece hard rubber case, in which the jars and case are made in one piece, the cell compartments being formed by rubber partitions which form an integral part of the case. This construction is used in several makes of Radio "A" batteries, and to some extent in starting batteries. [Fig. 16 Exide battery case] Asphaltum paint is generally used for wooden cases, the bottoms and tops being given three, coats, and the sides, two. The number of coats of paint varies, of course, in the different factories. The handles are then put on by machinery, and the case, Fig. 16, is complete, and ready for assembling. Assembling and Sealing The first step in assembling a battery is to burn the positive and negative plates to their respective straps, Fig. 5, forming the positive and negative "groups", Fig. 2. This is done by arranging a set of plates and a strap in a suitable rack which holds them securely in proper position, and then melting together the top of the plate lugs and the portion of the strap into which they fit with a hot flame. A positive and a negative group are now slipped together and the separators inserted. The grooved side of the wood separator is placed toward the positive plate and when perforated rubber sheets are used these go between the positive and the wood separator. The positive and negative "groups" assembled with the separators constitute the "element," Fig. 3. Before the elements are placed in the jars they are carefully inspected to make sure that no separator has been left out. For this purpose the "Exide" elements are subjected to an electrical test which rings a bell if a separator is missing, this having been found more infallible than trusting to a man's eyes. In some batteries, such as the Exide, Vesta, and Prest-O-Lite batteries, the cover is placed on the element and made fast before the elements are placed in the jars. In other batteries, such as the U. S. L. and Philadelphia batteries, the covers are put on after the elements are placed in the jars. After the element is in the jar and the cover in position, sealing compound is applied hot so as to make a leak proof joint between jar and cover. [Fig. 17 Inter-cell connector] The completed cells are now assembled in the case and the cell connectors, Fig. 17, burned to the strap posts. After filling with electrolyte the battery is ready to receive its "initial charge," which may require from one day to a week. A low charging rate is used, since the plates are generally in a sulphated condition when assembled. The specific gravity is brought up to about 1.280 during this charge. Some makers now give the battery a short high rate discharge test (see page 266), to disclose any defects, and just before sending them out give a final charge. The batteries are often "cycled" after being assembled, this consisting in discharging and recharging the batteries several times to put the active material in the best working condition. If the batteries are to be shipped "wet," they are ready for shipping after the final charge and inspection. Batteries which are shipped "dry" need to have more work done upon them. Preparing Batteries for Dry Shipment There are three general methods of "dry" shipment. The first method consists of sending cases, plates, covers, separators, etc., separately, and assembling them in the service stations. Sometimes these parts are all placed together, as in a finished battery, but without the separators, the covers not being sealed, or the connectors and terminals welded to the posts. This is a sort of "knock-down" condition. The plates used are first fully charged and dried. The second method consists of assembling a battery complete with plates, separators, and electrolyte, charging the battery, pouring out the electrolyte, rinsing with distilled water, pouring out the water and screwing the vent plugs down tight. The vent holes in these plugs are sealed to exclude air. The moisture left in the battery when the rinsing water was poured out cannot evaporate, and the separators are thus kept in a moistened condition. The third method is the Willard "Bone Dry" method, and consists of assembling the battery complete with dry threaded rubber separators and dry plates, but without electrolyte. The holes in the vent plugs are not sealed, since there is no moisture in the battery. Batteries using wooden separators cannot be shipped "bone-dry," since wooden separators must be kept moist. Terminal Connections When the battery is on the car it is necessary to have some form of detachable connection to the car circuit and this is accomplished by means of "terminal connectors," Fig. 18, of which there are many types. [Fig. 18 Battery terminal] Many types of terminals are in two parts, one being permanently attached to the car circuit and the other mounted permanently on the battery by welding it to the terminal post, the two parts being detachably joined by means of a bolted connection. In another type of terminal, the cable is soldered directly to the terminal which is lead burned to the cell post. In this construction there is very much less chance of corrosion taking place, and it is therefore a good design. HOMEMADE BATTERIES The wisest thing for the battery shop owner to do is to get a contract as official service station for one of the well known makes of batteries. The manufacturers of this battery will stand behind the service station, giving it the benefits of its engineering, production, and advertising departments, and boost the service station's business, helping to make it a success. Within the past year or so, however, some battery repairmen have conceived the idea that they do not need the backing of a well organized factory, and have decided to build up their own batteries. Some of them merely assemble batteries from parts bought from one or more manufacturers. If all the parts are made by the same company, they will fit together, and may make a serviceable battery. Often, however, parts made by several manufacturers are assembled in the same battery. Here is where trouble is apt to develop, because it is more than likely that jars may not fit well in the case; plates may not completely fill the jars, allowing too much acid space, with the results that specific gravity readings will not be reliable, and the plates may be overworked; plate posts may not fit the cover holes, and so on. If such a "fabricated" battery goes dead because of defective material, there is no factory back of the repairman to stand the loss. If the repairman wishes to assemble batteries, he should be very careful to buy the parts from a reliable manufacturer, and he should be especially careful in buying separators, as improperly treated separators often develop acetic acid, which dissolves the lead of the plates very quickly and ruins the battery. Batteries made in this way are good for rental batteries, or "loaners." These batteries are assembled and charged just as are batteries which have been in dry storage, see page 241. If the repairman who "fabricates" batteries takes chances, the man who attempts to actually make his own battery plates is certainly risking his business and reputation. There are several companies which sell moulds for making plate grids. One even sells cans of lead oxides to enable the repairman to make his own plate paste. Even more foolhardy than the man who wishes to mould plate grids is the man who wishes to mix the lead oxides himself. Many letters asking for paste formulas have been received by the author. Such formulas can never be given, for the author does not have them. Paste making is a far more difficult process than many men realize. The lead oxides which are used must be tested and analyzed carefully in a chemical laboratory and the paste formulas varied according to the results of these tests. The oxides must be carefully weighed, carefully handled, and carefully analyzed. The battery service station does not have the equipment necessary to do these things, and no repairman should ever attempt to make plate paste, as trouble is bound to follow such attempts. A car owner may buy a worthless battery once, but the next time he will go to some other service station and buy a good battery. No doubt many repairmen are as skillful and competent as the workers in battery factories, but the equipment required to make grids and paste is much too elaborate and expensive for the service station, and without such equipment it is impossible to make a good battery. The only battery parts which may safely be made in the service station are plate straps and posts, intercell connectors, and cell terminals. Moulds for making such parts are on the market, and it is really worth while to invest in a set. The posts made in such moulds are of the plain tapered type, and posts which have special sealing and locking devices, such as the Exide, Philadelphia, and Titan cannot be made in them. ======================================================================== CHAPTER 4. CHEMICAL CHANGES. ----------------- Before explaining what happens within one storage cell, let us look into the early history of the storage battery, and see what a modest beginning the modern heavy duty battery had. Between 1850 and 1860 a man named Plante began his work on the storage battery. His original cell consisted of two plates of metallic lead immersed in dilute sulphuric acid. The acid formed a thin layer of lead sulphate on each plate which soon stopped further action on the lead. If a current was passed through the cell, the lead sulphate on the "anode" or lead plate at which the current entered the cell was changed into peroxide of lead, while the sulphate on the other lead plate or "cathode" was changed into pure lead in a spongy form. This cell was allowed to stand for several days and was then "discharged," lead sulphate being again formed on each plate. Each time this cell was charged, more "spongy" lead and peroxide of lead were formed. These are called the "active" materials, because it is by the chemical action between them and the sulphuric acid that the electricity is produced. Evidently, the more active materials the plates contained, the longer the chemical action between the acid and active materials could take place, and hence the greater the "capacity," or amount of electricity furnished by the cell. The process of charging and discharging the battery so as to increase the amount of active material, is called "forming" the plates. [Fig. 19 Illustration of chemical action in a storage cell during charge] Plante's method of forming plates was very slow, tedious, and expensive. If the spongy lead, and peroxide of lead could be made quickly from materials which could be spread over the plates, much time and expense could be saved. It was Faure who first suggested such a plan, and gave us the "pasted" plate of today, which consists of a skeleton framework of lead, with the sponge lead and peroxide of lead filling the spaces between the "ribs" of the framework. Such plates are known as "pasted" plates, and are much lighter and more satisfactory, for automobile work than the heavy solid lead plates of Plante's. Chapter 3 describes more fully the processes of manufacturing and pasting the plates. We know now what constitutes a storage battery, and what the parts are that "generate" the electricity. How is the electricity produced? Theoretically, if we take a battery which has been entirely discharged, so that it is no longer able to cause a flow of current, and examine and test the electrolyte and the materials on the plates, we shall find that the electrolyte is pure water, and both sets of plates composed of white lead sulphate. On the other hand, if we make a similar test and examination of the plates and electrolyte of a battery through which a current has been sent from some outside source, such as a generator, until the current can no longer cause chemical reactions between the plates and electrolyte, we will find that the electrolyte is now composed of water and Sulphuric acid, the acid comprising about 30%, and the water 70% of the electrolyte. The negative set of plates will be composed of pure lead in a spongy form, while the positive will consist of peroxide of lead. The foregoing description gives the final products of the chemical changes that take place in the storage battery. To understand the changes themselves requires a more detailed investigation. The substances to be considered in the chemical actions are sulphuric acid, water, pure lead, lead sulphate, and lead peroxide. With the exception of pure lead, each of these substances is a chemical compound, or composed of several elements. Thus sulphuric acid is made up of two parts of hydrogen, which is a gas; one part of sulphur, a solid, and four parts of oxygen, which is also a gas; these combine to form the acid, which is liquid, and which is for convenience written as H2SO 4, H2 representing two parts of hydrogen, S one part of sulphur, and 04, four parts oxygen. Similarly, water a liquid, is made up of two parts of hydrogen and one part of oxygen, represented by the symbol H2O. Lead is not a compound, but an element whose chemical symbol is Pb, taken from the Latin name for lead. Lead sulphate is a solid, and consists of one part of lead, a solid substance, one part of sulphur, another solid substance, and four parts of oxygen, a gas. It is represented chemically by Pb SO4. Lead peroxide is also a solid, and is made up of one part of lead, and two parts of oxygen. In the chemical changes that take place, the compounds just described are to a certain extent split up into the substances of which they are composed. We thus have lead (Pb), hydrogen (H), oxygen (0), and sulphur (S), four elementary substances, two of which are solids, and two gases. The sulphur does not separate itself entirely from the substances with which it forms the compounds H2SO4 and Pb SO4. These compounds are split into H2 and SO4 and Pb and SO4 respectively. That is, the sulphur always remains combined with four parts of oxygen. Let us now consider a single storage cell made up of electrolyte, one positive plate, and one negative plate. When this cell is fully charged, or in a condition to produce a current of electricity, the positive plate is made up of peroxide of lead (PbO2), the negative plate of pure lead (Pb), and the electrolyte of dilute sulphuric acid (H 2SO4). This is shown diagrammatically in Fig. 19. The chemical changes that take place when the cell is discharging and the final result of the changes are as follows: (a). At the Positive Plate: Lead peroxide and sulphuric acid produce lead sulphate, water, and oxygen, or: [Image] Formula (a). PbO2 + H2SO4 = PbSO4 + H20 + 0 (b). At the Negative Plate: Lead and sulphuric acid produce lead sulphate and Hydrogen, or: [Image] Formula (b). Pb + H2SO4 = PbSO4 + H2 [Fig. 20 Chemical Reaction in a Storage Cell during Discharge] The oxygen of equation (a) and the hydrogen of equation (b) combine to form water, as may be shown by adding these two equations, giving one equation for the entire discharge action: [Image] Formula (c). PbO2 + Pb + 2H2SO4 = 2PbSO4 + 2H2O In this equation we start with the active materials and electrolyte in their original condition, and finish with the lead sulphate and water, which are the final products of a discharge. Examining this equation, we see that the sulphuric acid of the electrolyte is used up in forming lead sulphate on both positive and negative plates, and is therefore removed from the electrolyte. This gives us the easily remembered rule for remembering discharge actions, which, though open to question from a strictly scientific viewpoint, is nevertheless convenient: During discharge the acid goes into the plates. The chemical changes described in (a), (b), and (c) are not instantaneous. That is, the lead, lead peroxide, and sulphuric acid of the fully charged cell are not changed into lead sulphate and water as soon as a current begins to pass through the cell. This action is a gradual one, small portions of these substances being changed at a time. The greater the current that flows through the cell, the faster will the changes occur. Theoretically, the changes will continue to take place as long as any lead, lead peroxide, and sulphuric acid remain. The faster these are changed into lead sulphate and water, the shorter will be the time that the storage cell can furnish a current, or the sooner it will be discharged. Taking the cell in its discharged condition, let us now connect the cell to a generator and send current through the cell from the positive to the negative plates. This is called "charging" the cell. The lead sulphate and water will now gradually be changed back into lead, lead peroxide, and sulphuric acid. The lead sulphate which is on the negative plate is changed to pure lead; the lead sulphate on the positive plate is changed to lead peroxide, and sulphuric acid will be added to the water. The changes at the positive plate may be represented as follows: Lead sulphate and water produce sulphuric acid, hydrogen and lead peroxide, or: [Image] Formula (d). PbSO4 + 2H2O = PbO2 + H2SO4 + H2 The changes at the negative plate may be expressed as follows: Lead sulphate and water produced sulphuric acid, oxygen, and lead, or: [Image] Formula (e). PbSO4 + H2o = Pb + H2SO4 + O The hydrogen (H2) produced at the positive plate, and the oxygen (0) produced at the negative plate unite to form water, as may be shown by the equation: [Image] Formula (f). 2PbSO4 + 2H2O = PbO2 + Pb + 2H2SO4 Equation (f) starts with lead sulphate and water, which, as shown in equation (c), are produced when a battery is discharged. It will be observed that we start with lead sulphate and water. Discharged plates may therefore be charged in water. In fact, badly discharged negatives may be charged better in water than in electrolyte. The electrolyte is poured out of the battery and distilled water poured in. The acid remaining on the separators and plates is sufficient to make the water conduct the charging current. In equation (f), the sulphate on the plates combines with water to form sulphuric acid. This gives us the rule: During charge, acid is driven out of the plates. This rule is a convenient one, but, of course, is not a strictly correct statement. The changes produced by sending a current through the cell are also gradual, and will take place faster as the current is made greater. When all the lead sulphate has been used up by the chemical changes caused by the current, no further charging can take place. If we continue to send a current through the cell after it is fully charged, the water will continue to be split up into hydrogen and oxygen. Since, however, there is no more lead sulphate left with which the hydrogen and oxygen can combine to form lead, lead peroxide, and sulphuric acid, the hydrogen and oxygen rise to the surface of the electrolyte and escape from the cell. This is known as "gassing", and is an indication that the cell is fully charged. Relations Between Chemical Actions and Electricity. We know now that chemical actions in the battery produce electricity and that, on the other hand, an electric current, sent through the battery from an outside source, such as a generator, produces chemical changes in the battery. How are chemical changes and electricity related? The various chemical elements which we have in a battery are supposed to carry small charges of electricity, which, however, ordinarily neutralize one another. When a cell is discharging, however, the electrolyte, water, and active materials are separated into parts carrying negative and positive charges, and these "charges" cause what we call an electric current to flow in the apparatus attached to the battery. Similarly, when a battery is charged, the charging current produces electrical "charges" which cause the substances in the battery to unite, due to the attraction of position and negative charges for one another. This is a brief, rough statement of the relations between chemical reactions and electricity in a battery. A more thorough study of the subject would be out of place in this book. It is sufficient for the repairman to remember that the substances in a battery carry charges of electricity which become available as an electric current when a battery discharges, and that a charging current causes electric charges to form, thereby "charging" the battery. ======================================================================== CHAPTER 5. WHAT TAKES PLACE DURING DISCHARGE. ---------------------------------- Considered chemically, the discharge of a storage battery consists of the changing of the spongy lead and lead peroxide into lead sulphate, and the abstraction of the acid from the electrolyte. Considered electrically, the changes are more complex, and require further investigation. The voltage, internal resistance, rate of discharge, capacity, and other features must be considered, and the effects of changes in one upon the others must be studied. This proceeding is simplified considerably if we consider each point separately. The abstraction of the acid from the electrolyte gives us a method of determining the condition of charge or discharge in the battery, and must also be studied. [Fig. 21 Graph: voltage changes at end and after charge] Voltage Changes During Discharge. At the end of a charge, and before opening the charging circuit, the voltage of each cell is about 2.5 to 2.7 volts. As soon as the charging circuit is opened, the cell voltage drops rapidly to about 2.1 volts, within three or four minutes. This is due to the formation of a thin layer of lead sulphate on the surface of the negative plate and between the lead peroxide and the metal of the positive plate. Fig. 21 shows how the voltage changes during the last eight minutes of charge, and how it drops rapidly as soon as the charging circuit is opened. The final value of the voltage after the charging circuit is opened is about 2.15-2.18 volts. This is more fully explained in Chapter 6. If a current is drawn from the battery at the instant the charge is stopped, this drop is more rapid. At the beginning of the discharge the voltage has already had a rapid drop from the final voltage on charge, due to the formation of sulphate as explained above. When a current is being drawn from the battery, the sudden drop is due to the internal resistance of the cell, the formation of more sulphate, and the abstracting of the acid from the electrolyte which fills the pores of the plate. The density of this acid is high just before the discharge is begun. It is diluted rapidly at first, but a balanced condition is reached between the density of the acid in the plates and in the main body of the electrolyte, the acid supply in the plates being maintained at a lowered density by fresh acid flowing into them from the main body of electrolyte. After the initial drop, the voltage decreases more slowly, the rate of decrease depending on the amount of current drawn from the battery. The entire process is shown in Fig. 22. [Fig. 22 Graph: voltage changes during discharge] Lead sulphate is being formed on the surfaces, and in the body of the plates. This sulphate has a higher resistance than the lead or lead peroxide, and the internal resistance of the cell rises, and contributes to the drop in voltage. As this sulphate forms in the body of the plates, the acid is used up. At first this acid is easily replaced from the main body of the electrolyte by diffusion. The acid in the main body of the electrolyte is at first comparatively strong, or concentrated, causing a fresh supply of acid to flow into the plates as fast as it is used up in the plates. This results in the acid in the electrolyte growing weaker, and this, in turn, leads to a constant decrease in the rate at which the fresh acid flows, or diffuses into the plates. Furthermore, the sulphate, which is more bulky than the lead or lead peroxide fills the pores in the plate, making it more and more difficult for acid to reach the interior of the plate. This increases the rate at which the voltage drops. The sulphate has another effect. It forms a cover over the active material which has not been acted upon, and makes it practically useless, since the acid is almost unable to penetrate the coating of sulphate. We thus have quantities of active material which are entirely enclosed in sulphate, thereby cutting down the amount of energy which can be taken from the battery. Thus the formation of sulphate throughout each plate and the abstraction of acid from the electrolyte cause the voltage to drop at a constantly increasing rate. Theoretically, the discharge may be continued until the voltage drops to zero, but practically, the discharge should be stopped when the voltage of each cell has dropped to 1.7 (on low discharge rates). If the discharge is carried on beyond this point much of the spongy lead and lead peroxide have either been changed into lead sulphate, or have been covered up by the sulphate so effectively that they are almost useless. Plates in this condition require a very long charge in order to remove all the sulphate. The limiting value of 1.7 volts per cell applies to a continuous discharge at a moderate rate. At a very high current flowing for only a very short time, it is not only safe, but advisable to allow a battery to discharge to a lower voltage, the increased drop being due to the rapid dilution of the acid in the plates. The cell voltage will rise somewhat every time the discharge is stopped. This is due to the diffusion of the acid from the main body of electrolyte into the plates, resulting in an increased concentration in the plates. If the discharge has been continuous, especially if at a high rate, this rise in voltage will bring the cell up to its normal voltage very quickly on account of the more rapid diffusion of acid which will then take place. The voltage does not depend upon the area of the plate surface but upon the nature of the active materials and the electrolyte. Hence, although the plates of a cell are gradually being covered with sulphate, the voltage, measured when no current is flowing, will fall slowly and not in proportion to the amount of energy taken out of the cell. It is not until the plates are pretty thoroughly covered with sulphate, thus making it difficult for the acid to reach the active material, that the voltage begins to drop rapidly. This is shown clearly in Fig. 22, which shows that the cell voltage has dropped only a very small amount when the cell is 50% discharged. With current flowing through the cell, however, the increased internal resistance causes a marked drop in the voltage. Open circuit voltage is not useful, therefore to determine how much energy has been taken from the battery. Acid Density. The electrolyte of a lead storage battery is a mixture of chemically pure sulphuric acid, and chemically pure water, the acid forming about 30 per cent of the volume of electrolyte when the battery is fully charged. The pure acid has a "specific gravity" of 1.835, that is, it is 1.835 times as heavy as an equal volume of water. The mixture of acid and water has a specific gravity of about 1.300. As the cell discharges, acid is abstracted from the electrolyte, and the weight of the latter must therefore grow less, since there will be less acid in it. The change in the weight, or specific gravity of the electrolyte is the best means of determining the state of discharge of a cell, provided that the cell has been used properly. In order that the value of the specific gravity may be used as an indication of the amount of energy in a battery, the history of the battery must be known. Suppose, for instance, that in refilling the battery to replace the water lost by the natural evaporation which occurs in the use of a battery, acid, or a mixture of acid and water has been used. This will result in the specific gravity being too high, and the amount of energy in the battery will be less than that indicated by the specific gravity. Again, if pure water is used to replace electrolyte which has been spilled, the specific gravity will be lower than it should be. In a battery which has been discharged to such an extent that much of the active material has been covered by a layer of tough sulphate, or if a considerable amount of sulphate and active material has been loosened from the plates and has dropped to the bottom of the cells, it will be impossible to bring the specific gravity of the electrolyte up to 1.300, even though a long charge is given. There must, therefore, be a reasonable degree of certainty that a battery has been properly handled if the specific gravity readings are to be taken as a true indication of the condition of a battery. Where a battery does not give satisfactory service even though the specific gravity readings are satisfactory, the latter are not reliable as indicating the amount of charge in the battery. As long as a discharge current is flowing from the battery, the acid within the plates is used up and becomes very much diluted. Diffusion between the surrounding electrolyte and the acid in the plates keeps up the supply needed in the plates in order to, carry on the chemical changes. When the discharge is first begun, the diffusion of acid into the plates takes place rapidly because there is little sulphate clogging the pores in the active material, and because there is a greater difference between the concentration of acid in the electrolyte and in the plates than will exist as the discharge progresses. As the sulphate begins to form and fill up the pores of the plates, and as more and more acid is abstracted from the electrolyte, diffusion takes place more slowly. If a battery is allowed to stand idle for a short time after a partial discharge, the specific gravity of the electrolyte will decrease because some, of the acid in the electrolyte will gradually flow into the pores of the plates to replace the acid used up while the battery was discharging. Theoretically the discharge can be continued until all the acid has been used up, and the electrolyte is composed of pure water. Experience has shown, however, that the discharge of the battery should not be continued after the specific gravity of the electrolyte has fallen to 1.150. As far as the electrolyte is concerned, the discharge may be carried farther with safety. The plates determine the point at which the discharge should be stopped. When the specific gravity has dropped from 1.300 to 1.150, so much sulphate has been formed that it fills the pores in the active material on the plates. Fig. 23 shows the change in the density of the acid during discharge. [Fig. 23: Variation of Capacity with Specific Gravity] Changes at the Negative Plate. Chemically, the action at the negative plate consists only of the formation of lead sulphate from the spongy lead. The lead sulphate is only slightly soluble in the electrolyte and is precipitated as soon as it is formed, leaving hydrogen ions, which then go to the lead peroxide plate to form water with oxygen ions released at the peroxide plate. The sulphate forms more quickly on the surface of the plate than in the inner portions because there is a constant supply of acid available at the surface, whereas the formation of sulphate in the interior of the plate requires that acid diffuse into the pores of the active materials to replace that already used up in the formation of sulphate. In the negative plate, however, the sulphate tends to form more uniformly throughout the mass of the lead, because the spongy lead is more porous than the lead peroxide, and because the acid is not diluted by the formation of water as in the positive plate. Changes at the Positive Plate. In a fully charged positive plate we have lead peroxide as the active material. This is composed of lead and oxygen. From this fact it is plainly evident that during discharge there is a greater chemical activity at this plate than at the negative plate, since we must find something to combine with the oxygen in order that the lead may form lead sulphate with the acid. In an ideal cell, therefore, the material which undergoes the greater change should be more porous than the material which does not involve as great a chemical reaction. In reality, however, the peroxide is not as porous as the spongy lead, and does not hold together as well. The final products of the discharge of a positive plate are lead sulphate and water. The lead peroxide must first be reduced to lead, which then combines with the sulphate from the acid to form lead sulphate, while the oxygen from the peroxide combines with the hydrogen of the acid to form water. There is, therefore, a greater activity at this plate than at the lead plate, and the formation of the water dilutes the acid in and around the plate so that the tendency is for the chemical actions to be retarded. The sulphate which forms on discharge causes the active material to bulge out because it occupies more space than the peroxide. This causes the lead peroxide at the surface to begin falling, to the bottom of the jar in fine dust-like particles, since the peroxide here holds together very poorly. ======================================================================== CHAPTER 6. WHAT TAKES PLACE DURING CHARGE. ------------------------------- Voltage. Starting with a battery which has been discharged until its voltage has decreased to 1.7 per cell, we pass a current through it and cause the voltage to rise steadily. Fig. 24 shows the changes in voltage during charge. Ordinarily the voltage begins to rise immediately and uniformly. If, however, the battery has been left in a discharged condition for some time, or has been "over discharged," the voltage rises very rapidly for a fraction of the first minute of charge and then drops rapidly to the normal value and thereafter begins to rise steadily to the end of the charge. This rise at the beginning of the charge is due to the fact that the density of the acid in the pores of the plates rises rapidly at first, the acid thus formed being prevented from diffusing into the surrounding electrolyte by the coating of sulphate. As soon as this sulphate is broken through, diffusion takes place and the voltage drops. [Fig. 24 Graph: voltage changes during charge] As shown in Fig. 24, the voltage remains almost constant between the points M and N. At N the voltage begins to rise because the charging chemical reactions are taking place farther and farther in the inside parts of the plate, and the concentrated acid formed by the chemical actions in the plates is diffusing into the main electrolyte. This increases the battery voltage and requires a higher charging voltage. At the point marked 0, the voltage begins to rise very rapidly. This is due to the fact that the amount of lead sulphate in the plates is decreasing very rapidly, allowing the battery voltage to rise and thus increasing the charging voltage. Bubbles of gas are now rising through the electrolyte. At P, the last portions of lead sulphate are removed, acid is no longer being formed, and hydrogen and oxygen gas are formed rapidly. The gas forces the last of the concentrated acid out of the plates and in fact, equalizes the acid concentration throughout the whole cell. Thus no further changes can take place, and the voltage becomes constant at R at a voltage of 2.5 to 2.7. Density of Electrolyte. Discharge should be stopped when the density of the electrolyte, as measured with a hydrometer, is 1.150. When we pass a charging current through the battery, acid is produced by the chemical actions which take place in the plates. This gradually diffuses with the main electrolyte and causes the hydrometer to show a higher density than before. This increase in density continues steadily until the battery begins to "gas" freely. The progress of the charge is generally determined by the density of the electrolyte. For this purpose in automobile batteries, a hydrometer is placed in a glass syringe having a short length of rubber tubing at one end, and a large rubber bulb at the other. The rubber tube is inserted in the cell and enough electrolyte drawn up into the syringe to float the hydrometer so as to be able to obtain a reading. This subject will be treated more fully in a later chapter. Changes at Negative Plate. The charging current changes lead sulphate into spongy lead, and acid is formed. The acid is mixed with the diluted electrolyte outside of the plates. As the charging proceeds the active material shrinks or contracts, and the weight of the plate actually decreases on account of the difference between the weight and volume of the lead sulphate and spongy lead. If the cell has had only a normal discharge and the charge is begun soon after the discharge ended, the charge will proceed quickly and without an excessive rise in temperature. If, however, the cell has been discharged too far, or has been in a discharged condition for some time, the lead sulphate will not be in a finely divided state as it should be, but will be hard and tough and will have formed an insulating coating over the active material, causing the charging voltage to be high, and the charge will proceed slowly. When most of the lead sulphate has been reduced to spongy lead, the charging current will be greater than is needed to carry on the chemical actions, and will simply decompose the water into hydrogen and oxygen, and the cell "gasses." Spongy lead is rather tough and coherent, it, and the bubbles of gas which form in the pores of the negative plate near the end of the charge force their way to the surface without dislodging any of the active material. Changes at the Positive Plate. When a cell has been discharged, a portion of the lead peroxide has been changed to lead sulphate, which has lodged in the pores of the active material and on its surface. During charge, the lead combines with oxygen from the water to form lead peroxide, and acid is formed. This acid diffuses into the electrolyte as fast as the amount of sulphate will permit. If the discharge has been carried so far that a considerable amount of sulphate has formed in the pores and on the surface of the plate, the action proceeds very slowly, and unless a moderate charging current is used, gassing begins before the charge is complete, simply because the sulphate cannot absorb the current. The gas bubbles which originate in the interior of the plate force their way to the surface, and in so doing cause numerous fine particles of active material to break off and fall to the bottom of the jar. This happens because the lead peroxide is a granular, non-coherent substance, with the particles held together very loosely, and the gas breaks off a considerable amount of active material. ======================================================================== CHAPTER 7. CAPACITY OF STORAGE BATTERIES. ------------------------------ The capacity of a storage battery is the product of the current drawn from a battery, multiplied by the number of hours this current flows. The unit in which capacity is measured is the ampere-hour. Theoretically, a battery has a capacity of 40 ampere hours if it furnishes ten amperes for four hours, and if it is unable, at the end of that time, to furnish any more current. If we drew only five amperes from this battery, it should be able to furnish this current for eight hours. Thus, theoretically, the capacity of a battery should be the same, no matter what current is taken from it. That is, the current in amperes, multiplied by the number of hours the battery, furnished this current should be constant. In practice, however, we do not discharge a battery to a lower voltage than 1.7 per cell, except when the rate of discharge is high, such as is the case when using the starting motor, on account of the increasing amount of sulphate and the difficulty with which this is subsequently removed and changed into lead and lead peroxide. The capacity of a storage battery is therefore measured by the number of ampere hours it can furnish before its voltage drops below 1.7 per cell. This definition assumes that the discharge is a continuous one, that we start with a fully charged battery and discharge it continuously until its voltage drops to 1.7 per cell. The factors upon which the capacity of storage batteries depend may be grouped in two main classifications: 1. Design and Construction of Battery 2. Conditions of Operation Design and Construction. Each classification may be subdivided. Under the Design and Construction we have: (a) Area of plate surface. (b) Quantity, arrangement, and porosity of active materials. (c) Quantity and strength of electrolyte. (d) Circulation of electrolyte. These sub-classifications require further explanation. Taking them in order: (a) Area of Plate Surface. It is evident that the chemical and electrical activity of a battery are greatest at the surface of the plates since the acid and active material are in intimate contact here, and a supply of fresh acid is more readily available to replace that which is depleted as the battery is discharged. This is especially true with high rates of discharge, such as are caused in starting automobile engines. Therefore, the capacity of a battery will be greater if the surface area of its plates is increased. With large plate areas a greater amount of acid and active materials is available, and an increase in capacity results. (b) Quantity, Arrangement, and Porosity of Active Materials. Since the lead and lead peroxide are changed to lead sulphate on discharge, it is evident that the greater the amount of these materials, the longer can the discharge continue, and hence the greater the capacity. The arrangement of the active materials is also important, since the acid and active materials must be in contact in order to produce electricity. Consequently the capacity will be greater in a battery, all of whose active materials are in contact with the acid, than in one in which the acid reaches only a portion of the active materials. It is also important that all parts of the plates carry the same amount of current, in order that the active materials may be used evenly. As a result of these considerations, we find that the active materials are supported on grids of lead, that the plates are made thin, and that they have large surface areas. For heavy discharge currents, such as starting motor currents, it is essential that there be large surface areas. Thick plates with smaller surface areas are more suitable for low discharge rates. Since the inner portions of the active materials must have a plentiful and an easily renewable supply of acid, the active materials must be porous in order that diffusion may be easy and rapid. (c) Quantity and Strength of Electrolyte. It is important that there be enough electrolyte in order that the acid may not become exhausted while there is still considerable active material left. An insufficient supply of electrolyte makes it impossible to obtain the full capacity from a battery. On the other hand, too much electrolyte, due either to filling the battery too full, or to having the plates in a jar that holds too much electrolyte, results in an increase in capacity up to the limit of the plate capacity. There is a danger present, however, because with an excess of electrolyte the plates will be discharged before the specific gravity of the electrolyte falls to 1.150. This results in over discharge of the battery with its attendant troubles as will be described more fully in a later chapter. It is a universal custom to consider a battery discharged when the specific gravity of the electrolyte has dropped to 1.150, and that it is fully charged when the specific gravity of the electrolyte has risen to 1.280-1.300. This is true in temperate climates. In tropical countries, which may for this purpose be defined as those countries in which the temperature never falls below the freezing point, the gravity of a fully charged cell is 1.200 to 1.230. The condition of the plates is, however, the true indicator of charged or discharged condition. With the correct amount of electrolyte, its specific gravity is 1.150 when the plates have been discharged as far as it is considered safe, and is 1.280-1.300 when the plates are fully charged. When electrolyte is therefore poured into a battery, it is essential that it contains the proper proportion of acid and water in order that its specific gravity readings be a true indicator of the condition of the plates as to charge or discharge, and hence show accurately how much energy remains in the cell at any time. A question which may be considered at this point is why in automobile, work a specific gravity of 1.280-1.300 is adopted for the electrolyte of a fully charged cell. There are several reasons. The voltage of a battery increases as the specific gravity goes up. Hence, with a higher density, a higher voltage can be obtained. If the density were increased beyond this point, the acid would attack the lead grids and the separators, and considerable corrosion would result. Another danger of high density is that of sulphation, as explained in a later chapter. Another factor which enters is the resistance of the electrolyte. It is desirable that this be as low as possible. If we should make resistance measurements on various mixtures of acid and water, we should find that with a small percentage of acid, the resistance is high. As the amount of acid is increased, the resistance will grow less up to a certain point. Beyond this point, the resistance will increase again as more acid is added to the mixture. The resistance is lowest when the acid forms 30% of the electrolyte. Thus, if the electrolyte is made too strong, the plates and also the separators will be attacked by the acid, and the resistance of the electrolyte will also increase. The voltage increases as the proportion of acid is increased, but the other factors limit the concentration. If the electrolyte is diluted, its resistance rises, and the amount of acid is insufficient to give much capacity. The density of 1.280-1.300 is therefore a compromise between the various factors mentioned above. (d) Circulation of Electrolyte. This refers to the passing of electrolyte from one plate to another, and depends upon the ease with which the acid can pass through the pores of the separators. A porous separator allows more energy to be drawn from the battery than a nonporous one. Operating Conditions. Considering now the operating conditions, we find several items to be taken into account. The most important are: (e) Rate of discharge. (f) Temperature. (e) Rate of Discharge. As mentioned above, the ampere hour rating of a battery is based upon a continuous discharge, starting with a specific gravity of 1.280-1.300, and finishing with 1.150. The end of the discharge is also considered to be reached when the voltage per cell has dropped to 1.7. With moderate rates of discharge the acid is abstracted slowly enough to permit the acid from outside the plates to diffuse into the pores of the plates and keep up the supply needed for the chemical actions. With increased rates of discharge the supply of acid is used up so rapidly that the diffusion is not fast enough to hold up the voltage. This fact is shown clearly by tests made to determine the time required to discharge a 100 Amp. Hr., 6 volt battery to 4.5 volts. With a discharge rate of 25 amperes, it required 160 minutes. With a discharge rate of 75 amperes, it required 34 minutes. From this we see that making the discharge rate three times as great caused the battery to be discharged in one fifth the time. These discharges were continuous, however, and if the battery were allowed to rest, the voltage would soon rise sufficiently, to burn the lamps for a number of hours. The conditions of operation in automobile work are usually considered severe. In starting the engine, a heavy current is drawn from the battery for a few seconds. The generator starts charging the battery immediately afterward, and the starting energy is soon replaced. As long as the engine runs, there is no load on the battery, as the generator will furnish the current for the lamps, and also send a charge into the battery. If the lamps are not used, the entire generator output is utilized to charge the battery, unless some current is furnished to the ignition system. Overcharge is quite possible. When the engine is not running, the lamps are the only load on the battery, and there is no charging current. Various drivers have various driving conditions. Some use their starters frequently, and make only short runs. Their batteries run down. Other men use the starter very seldom, and take long tours. Their batteries will be overcharged. The best thing that can be done is to set the generator for an output that will keep the battery charged under average conditions. From the results of actual tests, it may be said that modem lead-acid batteries are not injured in any way by the high discharge rate used when a starting motor cranks the engine. It is the rapidity with which fresh acid takes the place of that used in the pores of the active materials that affects the capacity of a battery at high rates, and not only limitation in the plates themselves. Low rates of discharge should, in fact, be avoided more than the high rates. Battery capacity is affected by discharge rates, only when the discharge is continuous, and the reduction in capacity caused by the high rates of continuous discharge does not occur if the discharge is an intermittent one, such as is actually the case in automobile work. The tendency now is to design batteries to give their rated capacity in very short discharge periods. If conditions should demand it, these batteries would be sold to give their rated capacity while operating intermittently at a rate which would completely discharge them in three or four minutes. The only change necessary for such high rates of discharge is to provide extra heavy terminals to carry the heavy current. The present standard method of rating starting and lighting batteries, as recommended by the Society of Automotive Engineers, is as follows: "Batteries for combined lighting and starting service shall have two ratings. The first shall indicate the lighting ability, and shall be the capacity in ampere hours of the battery when discharged continuously at the 5 hour rate to a final voltage of not less than 1.7 per cell, the temperature of the battery beginning such discharge being 80°F. The second rating shall indicate the starting ability and shall be the capacity in ampere-hours when the battery is discharged continuously at the 20-minute rate to a final voltage of not less than 1.5 per cell, the temperature of the battery beginning such discharge being 80°F." The discharge rate required under the average starting conditions is higher than that specified above, and would cause the required drop in voltage in about fifteen minutes. In winter, when an engine is cold and stiff, the work required from the battery is even more severe, the discharge rate being equivalent in amperes to probably four or five times the ampere-rating of the battery. On account of the rapid recovery of a battery after a discharge at a very high rate, it seems advisable to allow a battery to discharge to a voltage of 1.0 per cell when cranking an engine which is extremely cold and stiff. (f) Temperature. Chemical reactions take place much more readily at high temperatures than at low. Furthermore, the active materials are more porous, the electrolyte lighter, and the internal resistance less at higher temperatures. Opposed to this is the fact that at high temperatures, the acid attacks the grids and active materials, and lead sulphate is formed, even though no current is taken from the battery. Other injurious effects are the destructive actions of hot acid on the wooden separators used in most starting and lighting batteries. Greater expansion of active material will also occur, and this expansion is not, in general, uniform over the surface of the plates. This results in unequal strains and the plates are bent out of shape, or "buckled." The expansion of the active material will also cause much of it to fall from the plates, and we then have "shedding." [Fig. 25 Graph: Theoretical temperature changes during charge and discharge] When sulphuric acid is poured into water, a marked temperature rise takes place. When a battery is charged, acid is formed, and when this mixes with the diluted electrolyte, a temperature rise occurs. In discharging, acid is taken from the electrolyte, and the temperature has a tendency to drop. On charging, therefore, there is danger of overheating, while on discharge, excessive temperatures are not likely. Fig. 25 shows the theoretical temperature changes on charge and discharge. The decrease in temperature given-in the curve is not actually obtained in practice, because the tendency of the temperature to decrease is balanced by the heat caused by the current passing through the battery. Age of Battery. Another factor which should be considered in connection with capacity is the age of the battery. New batteries often do not give their rated capacity when received from the manufacturer. This is due to the methods of making the plates. The "paste" plates, such as are used in automobiles, are made by applying oxides of lead, mixed with a liquid, which generally is dilute sulphuric acid, to the grids. These oxides must be subjected to a charging current in order to produce the spongy lead and lead peroxide. After the charge, they must be discharged, and then again charged. This is necessary because not all of the oxides are changed to active material on one charge, and repeated charges and discharges are required to produce the maximum amount of active materials. Some manufacturers do not charge and discharge a battery a sufficient number of times before sending it out, and after a battery is put into use, its capacity will increase for some time, because more active material is produced during each charge. Another factor which increases the capacity of a battery after it is put into use is the tendency of the positive active material to become more porous after the battery is put through the cycles of charge and discharge. This results in an increase in capacity for a considerable time after the battery is put into use. When, a battery has been in use for some time, a considerable portion of the active material will have fallen from the positive plates, and, a decrease in capacity will result. Such a battery will charge faster than a new one because the amount of sulphate which has formed when the battery is discharged is less than in a newer battery. Hence, the time required to reduce this sulphate will be less, and the battery will "come up" faster on charge, although the specific gravity of the electrolyte may not rise to 1.280. ======================================================================== CHAPTER 8. INTERNAL RESISTANCE. -------------------- The resistance offered by a storage battery to the flow of a current through it results in a loss of voltage, and in heating. Its value should be as low as possible, and, in fact, it is almost negligible even I in small batteries, seldom rising above 0.05 ohm. On charge, it causes the charging voltage to be higher and on discharge causes a loss of voltage. Fig. 26 shows the variation in resistance. [Fig. 26 Graph: Changes in internal resistance during charge and discharge] The resistance as measured between the terminals of a cell is made up of several factors as follows: 1. Grids. This includes the resistance of the terminals, connecting links, and the framework upon which the active materials are pasted. This is but a small part of the total resistance, and does not undergo any considerable change during charge and discharge. It increases slightly as the temperature of the grids rises. 2. Electrolyte. This refers to the electrolyte between the plates, and varies with the amount of acid and with temperature. As mentioned in the preceding chapter, a mixture of acid and water in which the acid composes thirty per cent of the electrolyte has the minimum resistance. Diluting or increasing the concentration of the electrolyte will both cause an increase in resistance from the minimum I value. The explanation probably lies in the degree to which the acid is split up into "ions" of hydrogen (H), and sulphate (SO4). These "ions" carry the current through t he electrolyte. Starting with a certain amount of acid, let us see how the ionization progresses. With very concentrated acid, ionization does not take place, and hence, there are no ions to carry current. As we mix the acid with water, ionization occurs. The more water used, the more ions, and hence, the less the resistance, because the number of ions available to carry the current increases. The ionization in creases to a certain maximum degree, beyond which no more ions are formed. It is probable that an electrolyte containing thirty per cent of acid is at its maximum degree of ionization and hence its lowest resistance. If more water is now added, no more ions are formed. Furthermore, the number of ions per unit volume of electrolyte will now decrease on account of the increased amount of water. There Will therefore be fewer ions per unit volume to carry the current, and the resistance of the electrolyte increases. With an electrolyte of a given concentration, an increase of temperature will cause a decrease in resistance. A decrease in temperature will, of course, cause an increase in resistance. It is true, in general, that the resistance of the electrolyte is about half of the total resistance of the cell. The losses due to this resistance generally form only one per cent of the total losses, and area practically negligible factor. 3. Active Material. This includes the resistance of the active materials and the electrolyte in the pores of the active materials. This varies considerably during charge and discharge. It has been found that the resistance of the peroxide plate changes much more than that of the lead plate. The change in resistance of the positive plate is especially marked near the end of a discharge. The composition of the active material, and the contact between it and the grid affect the resistance considerably. During charge, the current is sent into the cell from an external source. The girds therefore carry most of the current. The active material which first reacts with the acid is that near the surface of the plate, and the acid formed by the charging current mixes readily with the main body of electrolyte. Gradually, the charging action takes place in the inner portions of the plate, and concentrated acid is formed in the pores of the plate. As the sulphate is removed, however, the acid has little difficulty in mixing with the main body of electrolyte. The change in resistance on the charge is therefore not considerable. During discharge, the chemical action also begins at the surface of the plates and gradually moves inward. In this case, however, sulphate is formed on the surface first, and it becomes increasingly difficult for the fresh acid from the electrolyte to diffuse into the plates so as to replace the acid which has been greatly diluted there by the discharge actions. There is therefore an increase in resistance because of the dilution of the acid at the point of activity. Unless a cell is discharged too far, however, the increase in resistance is small. If a battery is allowed to stand idle for a long time it gradually discharges itself, as explained in Chapter 10. This is due to the formation of a tough coating of crystallized lead sulphate, which is practically an insulator. These crystals gradually cover and enclose the active material. The percentage change is not high, and generally amounts to a few per cent only. The chief damage caused by the excessive sulphation is therefore not an increase in resistance, but consists chiefly of making a poor contact between active material and grid, and of removing much of the active material from action by covering it. ======================================================================== CHAPTER 9. CARE OF THE BATTERY ON THE CAR. ------------------------------- The manufacturers of Starting and Lighting Equipment have designed their generators, cutouts, and current controlling devices so as to relieve the car owner of as much work as possible in taking care of batteries. The generators on most cars are automatically connected to the battery at the proper time, and also disconnected from it as the engine slows down. The amount of current which the generator delivers to the battery is automatically prevented from exceeding a certain maximum value. Under the average conditions of driving, a battery is kept in a good condition. It is impossible, however, to eliminate entirely the need of attention on the part of the car owner, and battery repairman. The storage battery requires but little attention, and this is the very reason why many batteries are neglected. Motorists often have the impression that because their work in caring for a battery is quite simple, no harm will result if they give the battery no attention whatever. If the battery fails to turn over the engine when the starting switch is closed, then instruction books are studied. Thereafter more attention is paid to the battery. The rules to be observed in taking care of the battery which is in service on the car are not difficult to observe. It is while on the car that a battery is damaged, and the damage may be prevented by intelligent consideration of the battery's housing and living conditions, just as these conditions are made as good as possible for human beings. 1. Keep the Interior of the Battery Box Clean and Dry. On many cars the battery is contained in an iron box, or under the seat or floorboards. This box must be kept dry, and frequent inspection is necessary to accomplish this. Moisture condenses easily in a metal box, and if not removed will cause the box to become rusty. Pieces of rust may fall on top of the battery and cause corrosion and leakage of current between terminals. Occasionally, wash the inside of the box with a rag dipped in ammonia, or a solution of baking soda, and then wipe it dry. A good plan is to paint the inside of the box with asphaltum paint. This will prevent rusting, and at the same time will prevent the iron from being attacked by electrolyte which may be spilled, or may leak from the battery. Some batteries are suspended from the car frame under the floor boards or seat. The iron parts near such batteries should be kept dry and free from rust. If the battery has a roof of sheet iron placed above it, this roof should also be kept clean, dry and coated with asphaltum paint. [Fig. 27 "Do not drop tools on top of battery"] 2. Put Nothing But the Battery in the Battery Box. If the battery is contained in an iron box, do not put rags, tools, or anything else of a similar nature in the battery box. Do not lay pliers across the top of the battery, as shown in Fig. 27. Such things belong elsewhere. The battery should have a free air space all around it, Fig. 28. Objects made of metal will short-circuit the battery and lead to a repair bill. 3. Keep the battery clean and dry. The top of the battery should be kept free of dirt, dust, and moisture. Dirt may find its way into the cells and damage the battery. A dirty looking battery is an unsightly object, and cleanliness should be maintained for the sake of the appearance of the battery if for no other reason. Moisture on top of the battery causes a leakage of current between the terminals of the cells and tends to discharge the battery. Wipe off all moisture and occasionally go over the tops of the cell connectors, and terminals with a rag wet with ammonia or a solution of baking soda. This will neutralize any acid which may be present in the moisture. The terminals should be dried and covered with vaseline. This protects them from being attacked by acid which may be spilled on top of the battery. If a deposit of a grayish or greenish substance is found on the battery terminals, handles or cell connectors, the excess should be scraped off and the parts should then be washed with a hot solution of baking soda (bicarbonate of soda) until all traces of the substance have been removed. In scraping off the deposit, care should be taken not to scrape off any lead from terminals or connectors. After washing the parts, dry them and cover them with vaseline. The grayish or greenish substance found on the terminals, connectors, or handles is the result of "corrosion," or, in other words, the result of the action of the sulphuric acid in the electrolyte upon some metallic substance. [Fig. 28 Battery installed with air space on all sides] The acid which causes the corrosion may be spilled on the battery when hydrometer readings are taken. It may also be the result of filling the cells too full, with subsequent expansion and overflowing as the temperature of the electrolyte increases during charge. Loose vent caps may allow electrolyte to be thrown out of the cell by the motion of the car on the road. A poorly sealed battery allows electrolyte to be thrown out through the cracks left between the sealing compound and the jars or posts. The leaks may be caused by the battery cables not having sufficient slack, and pulling on the terminals. The cap which fits over the vent tube at the center of the top of each cell is pierced by one or more holes through which gases formed within the cell may escape. These holes must be kept open; otherwise the pressure of the gases may blow off the top of the cell. If these holes are found to be clogged with dirt they should be cleaned out thoroughly. The wooden battery case should also be kept clean and dry. If the battery is suspended from the frame of the car, dirt and mud from the road will gradually cover the case, and this mud should be scraped off frequently. Occasionally wash the case with a rag wet with ammonia, or hot baking soda solution. Keep the case, especially along the top edges, coated with asphaltum or some other acid proof paint. [Fig. 29 Battery held in place by "hold-down" bolts] 4. The battery must be held down firmly. If the battery is contained in an iron box mounted on the running-board, or in a compartment in the body of the car having a door at the side of the running-board, it is usually fastened in place by long bolts which hook on the handles or the battery case. These bolts, which are known as "hold-downs," generally pass through the running board or compartment, Fig. 29, and are generally fastened in place by nuts. These nuts should be turned up so that the battery is held down tight. Other methods are also used to hold the battery in place, but whatever the method, it is vital to the battery that it be held down firmly so that the jolting of the car cannot cause it to move. The battery has rubber jars which are brittle, and which are easily broken. Even if a battery is held down firmly, it is jolted about to a considerable extent, and with a loosely fastened battery, the jars are bound to be cracked and broken. 5. The cables connected to the battery must have sufficient slack so that they will not pull on the battery terminals, as this will result in leaks, and possibly a broken cover. The terminals on a battery should be in such a position that the cables may be connected to them easily, and without bending and twisting them. These cables are heavy and stiff, and once they are bent or twisted they are put under a strain, and exert a great force to straighten themselves. This action causes the cables to pull on the terminals, which become loosened, and cause a leak, or break the cover. [Fig. 30 Measure height of electrolyte in battery] 6. Inspect the Battery twice every month in Winter, and once a week in Summer, to make sure that the Electrolyte covers the plates. To do this, remove the vent caps and look down through the vent tube. If a light is necessary to determine the level of the electrolyte, use an electric lamp. Never bring an open flame, such as a match or candle near the vent tubes of a battery. Explosive gases are formed when a battery "gasses," and the flame may ignite them, with painful injury to the face and eyes of the observer as a result. Such an explosion may also ruin the battery. During the normal course of operation of the battery, water from the electrolyte will evaporate. The acid never evaporates. The surface of the electrolyte should be not less than one-half inch above the tops of the plate. A convenient method of measuring the height of the electrolyte is shown in Fig. 30. Insert one end of a short piece of a glass tube, having an opening not less than one-eighth inch diameter, through the filling hole, and allow it to rest on the upper edge of the plates. Then place your finger over the upper end, and withdraw the tube. A column of liquid will remain in the lower end of the tube, as shown in the figure, and the height of this column is the same as the height of the electrolyte above the top of the plates in the cell. If this is less than one-half inch, add enough distilled water to bring the electrolyte up to the proper level. Fig. 31 shows the correct height of electrolyte in an Exide cell. Never add well water, spring water, water from a stream, or ordinary faucet water. These contain impurities which will damage the battery, if used. It is essential that distilled water be used for this purpose, and it must be handled carefully so as to keep impurities of any kind out of the water. Never use a metal can for handling water or electrolyte for a battery, but always use a glass or porcelain vessel. The water should be stored in glass bottles, and poured into a porcelain or glass pitcher when it is to be used. [Fig. 31 Correct height of electrolyte in Exide cell] A convenient method of adding the water to the battery is to draw some up in a hydrometer syringe and add the necessary amount to the cell by inserting the rubber tube which is at the lower end into the vent hole and then squeezing the bulb until the required amount has been put into the cell. In the summer time it makes no difference when water is added. In the winter time, if the air temperature is below freezing (32° F), start the engine before adding water, and keep it running for about one hour after the battery begins to "gas." A good time to add the water is just before starting on a trip, as the engine will then usually be run long enough to charge the battery, and cause the water to mix thoroughly with the electrolyte. Otherwise, the water, being lighter than the electrolyte, will remain at the top and freeze. Be sure to wipe off water from the battery top after filling. If battery has been wet for sometime, wipe it with a rag dampened with ammonia or baking soda solution to neutralize the acid. Never add acid to a battery while the battery is on the car. By "acid" is meant a mixture of sulphuric acid and water. The concentrated acid, is of course, never used. The level of the electrolyte falls because of the evaporation of the water which is mixed with the acid in the electrolyte. The acid does not evaporate. It is therefore evident that acid should not be added to a cell to replace the water which has evaporated. Some men believe that a battery may be charged by adding acid. This is not true, however, because a battery can be charged only by passing a current through the battery from an outside source. On the car the generator charges the battery. It is true that acid is lost, but this is not due to evaporation, but to the loss of some of the electrolyte from the cell, the lost electrolyte, of course, carrying some acid with it. Electrolyte is lost when a cell gasses; electrolyte may be spilled; a cracked jar will allow electrolyte to leak out; if too much water is added, the expansion of the electrolyte when the battery is charging may cause it to run over and be lost, or the jolting of the car may cause some of it to be spilled; if a battery is allowed to become badly sulphated, some of the sulphate is never reduced, or drops to the bottom of the cell, and the acid lost in the formation of the sulphate is not regained. If acid or electrolyte is added instead of water, when no acid is needed, the electrolyte will become too strong, and sulphated plates will be the result. If a battery under average driving conditions never becomes fully charged, it should be removed from the car and charged from an outside source as explained later. If, after the specific gravity of the electrolyte stops rising, it is not of the correct value, some of the electrolyte should be drawn off and stronger electrolyte added in its place. This should be done only in the repair shop or charging station. Care must be taken not to add too much water to a cell, Fig. 32. This will subsequently cause the electrolyte to overflow and run over the top of the battery, due to the expansion of the electrolyte as the charging current raises its temperature. The electrolyte which overflows is, of course, lost, taking with it acid which will later be replaced by water as evaporation takes place. The electrolyte will then be too weak. The electrolyte which overflows will rot the wooden battery case, and also tend to cause corrosion at the terminals. If it is necessary to add water very frequently, the battery is operating at too high a temperature, or else there is a cracked jar. The high temperature may be due to the battery being charged at too high a rate, or to the battery being placed near some hot part of the engine or exhaust pipe. The car manufacturer generally is careful not to place the battery too near any such hot part. The charging rate may be measured by connecting an ammeter in series with the battery and increasing the engine speed until the maximum current is obtained. For a six volt battery this should rarely exceed 14 amperes. If the charging, current does not reach a maximum value and then remain constant, or decrease, but continues to rise as the speed of the engine, is increased, the regulating device is out of order. An excessive charging rate will cause continuous gassing if it is much above normal, and the temperature of the electrolyte will be above 100° F. In this way an excessive charging current may be detected. [Fig. 32 Cell with level of electrolyte too high] In hot countries or states, the atmosphere may have such a high temperature that evaporation will be more rapid than in temperate climates, and this may necessitate more frequent addition of water. If one cell requires a more frequent addition of water than the others, it is probable that the jar of that cell is cracked. Such a cell will also show a low specific gravity, since electrolyte leaks out and is replaced by water. A battery which has a leaky jar will also have a case which is rotted at the bottom and sides. A battery with a leaky jar must, of course, be removed from the car for repairs. "Dope" Electrolytes From time to time within the past two years, various solutions which are supposed to give a rundown battery a complete charge within five or ten minutes have been offered to the public. The men selling such "dope" sometimes give a demonstration which at first sight seems to prove their claims. This demonstration consists of holding the starting switch down (with the ignition off) until the battery can no longer turn over the engine. They then pour the electrolyte out of the battery, fill it with their "dope," crank the engine by hand, run it for five minutes, and then get gravity readings of 1.280 or over. The battery will also crank the engine. Such a charge is merely a drug-store charge, and the "dope" is generally composed mainly of high gravity acid, which seemingly puts life into a battery, but in reality causes great damage, and shortens the life of a battery. The starting motor test means nothing. The same demonstration could be given with any battery. The high current drawn by the motor does not discharge the battery, but merely dilutes the electrolyte which is in the plates to such an extent that the voltage drops to a point at which the battery can no longer turn over the starting motor. If any battery were given a five minutes charge after such a test, the diluted electrolyte in the plates would be replaced by fresh acid from the electrolyte and the battery would then easily crank the engine again. The five minutes of running the engine does not put much charge into the battery but gives time for the electrolyte to diffuse into the plates. Chemical analysis of a number of dope electrolytes has shown that they consist mainly of high gravity acid, and that this acid is not even chemically pure, but contains impurities which would ruin a battery even if the gravity were not too high. The results of some of the analyses are as follows: No. 1. 1.260 specific gravity sulphuric acid, 25 parts iron, 13.5 parts chlorine, 12.5, per cent sodium sulphate, 1 per cent nitric acid. No. 2. 1.335 specific gravity sulphuric acid, large amounts of organic matter, part of which consisted of acids which attack lead. No. 3. 1.340 specific gravity sulphuric acid, 15.5 per cent sodium sulphate. No. 4. 1.290 specific gravity sulphuric acid, 1.5 per cent sodium sulphate. No. 5. 1.300 specific gravity sulphuric acid. If such "dope" electrolytes are added to a discharged battery, the subsequent charging of the battery will add more acid to the electrolyte, the specific gravity of which will then rise much higher than it should, and the plates and separators are soon ruined. Do not put faith in any "magic" solution which is supposed to work wonders. There is only one way to charge a battery, and that is to send a current through it, and there is only one electrolyte to use, and that is the standard mixture of distilled water and chemically pure sulphuric acid. 7. The specific gravity of the electrolyte should be measured every two weeks and a permanent record of the readings made for future reference. The specific gravity of the electrolyte is the ratio of its weight to the weight of an equal volume of water. Acid is heavier than water, and hence the heavier the electrolyte, the more acid it, contains, and the more nearly it is fully charged. In automobile batteries, a specific gravity of 1.300-1.280 indicates a fully charged battery. Generally, a gravity of 1.280 is taken to indicate a fully, charged cell, and in this book this will be done. Complete readings are as follows: 1.300-1.280--Fully charged. 1.280-1.200--More than half charged. 1.200-1.150--Less than half charged. 1.150 and less--Completely discharged. [Fig. 33 and Fig. 34: battery hydrometers] For determining the specific gravity, a hydrometer is used. This consists of a small sealed glass tube with an air bulb and a quantity of shot at one end, and a graduated scale on the upper end. This scale is marked from 1.100 to 1.300, with various intermediate markings as shown in Fig. 33. If this hydrometer is placed in a liquid, it will sink to a certain depth. In so doing, it will displace a certain volume of the electrolyte, and when it comes to rest, the volume displaced will just be equal to the weight of the hydrometer. It will therefore sink farther in a light liquid than in a heavy one, since it will require a greater volume of the light liquid to equal the weight of the hydrometer. The top mark on the hydrometer scale is therefore 1.100 and the bottom one 1.300. Some hydrometers are not marked with figures that indicate the specific gravity, but are marked with the words "Charged," "Half Charged," "Discharged," or "Full," "Half Full," "Empty," in place of the figures. The tube must be held in a vertical position, Fig. 35, and the stem of the hydrometer must be vertical. The reading will be the number on the stem at the surface of the electrolyte in the tube, Fig. 36. Thus if the hydrometer sinks in the electrolyte until the electrolyte comes up to the 1.150 mark on the stem, the specific gravity is 1.150. [Fig. 35 Using hydrometer for reading specific gravity] For convenience in automobile work, the hydrometer is enclosed in a large tube of glass or other transparent, acid proof material, having a short length of rubber tubing at its lower end, and a large rubber bulb at the upper end. The combination is called a hydrometer-syringe, or simply hydrometer. See Figure 34. In measuring the specific gravity of the electrolyte, the vent cap is removed, the bulb is squeezed (so as to expel the air from it), and the rubber tubing inserted in the hole from which the cap was removed. The pressure on the bulb is now released, and electrolyte is drawn up into the glass tube. The rubber tubing on the hydrometer should not be withdrawn from the cell. When a sufficient amount of electrolyte has entered the tube, the hydrometer will float. In taking a reading, there should be no pressure on the bulb, and the hydrometer should be floating freely and not touching the walls of the tube. The tube must not be so full of electrolyte that the upper end of the hydrometer strikes any part of the bulb. The tube must be held in a vertical position, Fig. 35, and the stem of the hydrometer must be vertical. The reading will be the number on the stem at the surface of the electrolyte in the tube, Fig. 36. Thus if the hydrometer sinks in the electrolyte until the electrolyte comes up to the 1.150 mark on the stem, the specific gravity is 1.150. If the battery is located in such a position that it is impossible to hold the hydrometer straight up, the rubber tube may be Pinched shut with the fingers, after a sufficient quantity of electrolyte has been drawn from the cell and the hydrometer then removed and held in a vertical position. Specific gravity readings should never be taken soon after distilled water has been added to the battery. The water and electrolyte do not mix immediately, and such readings will give misleading results. The battery should be charged several hours before the readings are taken. It is a good plan to take a specific gravity reading before adding any water, since accurate results can also be obtained in this way. [Fig. 36 Hydrometer reading showing cell charged, half-charged, and discharged] Having taken a reading, the bulb is squeezed so as to return the electrolyte to the cell. Care should be taken not to spill the electrolyte from the hydrometer syringe when testing the gravity. Such moisture on top of the cells tends to cause a short circuit between the terminals and to discharge the battery. In making tests with the hydrometer, the electrolyte should always be returned to the same cell from which it was drawn. Failure to do this will finally result in an increased proportion of acid in one cell and a deficiency of acid in others. The specific gravity of all cells of a battery should rise and fall together, as the cells are usually connected in series so that the same current passes through each cell both on charge and discharge. If one cell of a battery shows a specific gravity which is decidedly lower than that of the other cells in series with it, and if this difference gradually increases, the cell showing the lower gravity has internal trouble. This probably consists of a short circuit, and the battery should be opened for inspection. If the electrolyte in this cell falls faster than that of the other cells, a leaky jar is indicated. The various cells should have specific gravities within fifteen points of each other, such as 1.260 and 1.275. If the entire battery shows a specific gravity below 1.200, it is not receiving enough charge to replace the energy used in starting the engine and supplying current to the lights, or else there is trouble in the battery. Use starter and lights sparingly until the specific gravity comes up to 1.280-1.300. If the specific gravity is less than 1.150 remove the battery from the car and charge it on the charging bench, as explained later. The troubles which cause low gravity are given on pages 321 and 322. It is often difficult to determine what charging current should be delivered by the generator. Some generators operate at a constant voltage slightly higher than that of the fully charged battery, and the charging current will change, being higher for a discharged battery than for one that is almost or fully charged. Other generators deliver a constant current which is the same regardless of the battery's condition. In the constant voltage type of generator, the charging current automatically adjusts itself to the condition of the battery. In the constant current type, the generator current remains constant, and the voltage changes somewhat to keep the current constant. Individual cases often require that another current value be used. In this case, the output of the generator must be changed. With most generators, a current regulating device is used which may be adjusted so as to give a fairly wide range of current, the exact value chosen being the result of a study of driving conditions and of several trials. The charging current should never be made so high that the temperature of the electrolyte in the battery remains above 90° F. A special thermometer is very useful in determining the temperature. See Fig. 37. The thermometer bulb is immersed in the electrolyte above the plates through the filler hole in the tops of the cells. Batteries used on some of the older cars are divided into two or more sections which are connected in parallel while the engine is running, and in such cases the cables leading to the different sections should all be of exactly the same length, and the contacts in the switch which connect these sections in parallel should all be clean and tight. If cables of unequal length are used, or if some of the switch contacts are loose and dirty, the sections will not receive equal charging currents, because the resistances of the charging circuits will not be equal. The section having the greatest resistance in its circuit will receive the least amount of charge, and will show lower specific gravity readings than for other sections. In a multiple section battery, there is therefore a tendency for the various sections to receive unequal charges, and for one or more sections to run down continually. An ammeter should be attached with the engine running and the battery charging, first to one section and then to each of the others in turn. The ammeter should be inserted and removed from the circuit while the engine remains running and all conditions must be exactly the same; otherwise the comparative results will not give reliable indications. It would be better still to use two ammeters at the same time, one on each section of the battery. In case the amperage of charge should differ by more than 10% between any two sections, the section receiving the low charge rate should be examined for proper height of electrolyte, for the condition of its terminals and its connections at the starting switch, as described. Should a section have suffered considerably from such lack of charge, its voltage will probably have been lowered. With all connections made tight and clean and with the liquid at the proper height in each cell, this section may automatically receive a higher charge until it is brought back to normal. This high charge results from the comparatively low voltage of the section affected. In case the car is equipped with such a battery, each section must carry its proper fraction of the load and with lamps turned on or other electrical devices in operation the flow from the several sections must be the same for each one. An examination should be made to see that no additional lamps, such as trouble lamps or body lamps, have been attached on one side of the battery, also that the horn and other accessories are so connected that they draw from all sections at once. Some starting systems have in the past not been designed carefully in this respect, one section of the battery having longer cables attached to it than the others. In such systems it is impossible for these sections to receive as much charging current as others, even though all connections and switches are in good condition. In other systems, all the cells of the battery are in series, and therefore must receive the same charging current, but have lighting wires attached to it at intermediate points, thus dividing the battery into sections for the lighting circuits. If the currents taken by these circuits are not equal, the battery section supplying the heavier current will run down faster than others. Fortunately, multiple section batteries are not being used to any great extent at present, and troubles due to this cause are disappearing. The temperature of the electrolyte affects the specific gravity, since heat causes the electrolyte to expand. If we take any battery or cell and heat it, the electrolyte will expand and its specific gravity will decrease, although the actual amount of acid is the same. The change in specific gravity amounts to one point, approximately, for every three degrees Fahrenheit. If the electrolyte has a gravity of 1.250 at 70°F, and the temperature is raised to 73°F, the specific gravity of the battery will be 1.249. If the temperature is decreased to 67°F, the specific gravity will be 1.251. Since the change of temperature does not change the actual amount of acid in the electrolyte, the gravity readings as obtained with the hydrometer syringe should be corrected one point for every three degrees change in temperature. Thus 70°F is considered the normal temperature, and one point is added to the electrolyte reading for every three degrees above 70°F. Similarly, one point is subtracted for every three degrees below 70°F. For convenience of the hydrometer user, a special thermometer has been developed by battery makers. This is shown in Fig. 37. It has a special scale mounted beside the regular scale. This scale shows the corrections which must be made when the temperature is not 70°F. Opposite the 70° point on the thermometer is a "0" point on the special scale. This indicates that no correction is to be made. Opposite the 67° point on the regular scale is a -1, indicating that 1 must be subtracted from the hydrometer reading to find what the specific gravity would be if the temperature were 70°F. Opposite the 73° point on the regular scale is a +1, indicating that 1 point must be added to reading on the hydrometer, in order to reduce the reading of specific gravity to a temperature of 70°F. [Fig. 37 Special thermometer] 8. Storage batteries are strongly affected by changes in temperature. Both extremely high and very low temperatures are to be avoided. At low temperatures the electrolyte grows denser, the porosity of plates and separators decreases, circulation and diffusion of electrolyte are made difficult, chemical actions between plates and acid take place very slowly, and the whole battery becomes sluggish, and acts as if it were numbed with cold. The voltage and capacity of the battery are lowered. As the battery temperature increases, the density of the electrolyte decreases, the plates and separators become more porous, the internal resistance decreases, circulation and diffusion of electrolyte take place much more quickly, the chemical actions between plates and electrolyte proceed more rapidly, and the battery voltage and capacity increase. A battery therefore works better at high temperatures. Excessive temperatures, say over 110° F, are, however, more harmful than low temperatures. Evaporation of the water takes place very rapidly, the separators are attacked by the hot acid and are ruined, the active materials and plates expand to such an extent that the active materials break away from the grids and the grids warp and buckle. The active materials themselves are burned and made practically useless. The hot acid also attacks the grids and the sponge lead and forms dense layers of sulphate. Such temperatures are therefore extremely dangerous. A battery that persistently runs hot, requiring frequent addition of water, is either receiving too much charging current, or has internal trouble. The remedy for excessive charge is to decrease the output of the generator, or to burn the lamps during the day time. Motorists who make long touring trips in which considerable day driving is done, with little use of the starter, experience the most trouble from high temperature. The remedy is either to decrease the charging rate or burn the lamps, even in the day time. Internal short-circuits cause excessive temperature rise, both on charge and discharge. Such short circuits usually result from buckled plates which break through the separators, or from an excessive amount of sediment. This sediment consists of active material or lead sulphate which has dropped from the positive plate and fallen to the bottom of the battery jar. All battery jars are provided with ridges which keep the plates raised an inch or more from the bottom of the jar, and which form pockets into which the materials drop. See Fig. 10. If these pockets become filled, and the sediment reaches the bottom of the plates, internal short circuits result which cause the battery to run down and cause excessive temperatures. If the electrolyte is allowed to fall below the tops of the plates, the parts of the plates above the acid become dry, and when the battery is charged grow hot. The parts still covered by the acid also become hot because all the charging current is carried by these parts, and the plate surface is less than before. The water will also become hot and boil away. A battery which is thus "charged while dry" deteriorates rapidly, its life being very short. If a battery is placed in a hot place on the car, this heat in addition to that caused by charging will soften the plates and jars, and shorten their life considerably. In the winter, it is especially important not to allow the battery to become discharged, as there is danger of the electrolyte freezing. A fully charged battery will not freeze except at an extremely low temperature. The water expands as it freezes, loosening the active materials, and cracking the grids. As soon as a charging current thaws the battery, the active material is loosened, and drops to the bottom of the jars, with the result that the whole battery may disintegrate. Jars may also be cracked by the expansion of the water when a battery freezes. To avoid freezing, a battery should therefore be kept charged, The temperatures at which electrolyte of various specific gravities freezes are as follows: Specific Gravity Freezing Pt. Specific Gravity Freezing Pt. ---------------- ------------ ---------------- ------------ 1.000 32 deg. F 1.200 -16 deg. F 1.050 26 deg. F 1.250 -58 deg. F 1.100 18 deg. F 1.280 -92 deg. F 1.150 5 deg. F 1.300 -96 deg. F 9. Care of Storage Battery When Not in Service. A storage battery may be out of service for a considerable period at certain times of the year, for example, when the automobile is put away during the winter months, and during this time it should not be allowed to stand without attention. When the battery is to be out of service for only three or four weeks, it should be kept well filled with distilled water and given as complete a charge as possible the last few days, the car is in service by using the lamps and starting motor very sparingly. The specific gravity of the electrolyte in each cell should be tested, and it should be somewhere between 1.280 and 1.300. All connections to the battery should be removed, as any slight discharge current will in time completely discharge it, and the possibilities of such an occurrence are to be avoided. If the battery is to be put out of service for several months, it should be given a complete charge by operating the generator on the car or by connecting it to an outside charging circuit. During the out-of-service period, water should be added to the cells every six or eight weeks and the battery given what is called a freshening charge; that is, the engine should be run until the cells have been gassing for perhaps one hour, and the battery may then be allowed to stand for another similar period without further attention. Water should be added and the battery fully charged before it is put back into service. It is desirable to have the temperature of the room where the battery is stored fairly constant and as near 70 degrees Fahrenheit as possible. ======================================================================== CHAPTER 10. STORAGE BATTERY TROUBLES. ------------------------- The Storage Battery is a most faithful servant, and if given even a fighting chance, will respond instantly to the demands made upon it. Given reasonable care and consideration, it performs its duties faithfully for many months. When such care is lacking, however, it is soon discovered that the battery is subject to a number of diseases, most of which are "preventable," and all of which, if they do not kill the battery, at least, greatly impair its efficiency. In discussing these diseases, we may consider the various parts of which a battery is composed, and describe the troubles to which they are subject. Every battery used on an automobile is composed of: 1. Plates 2. Separators 3. Jars in which Plates, Separators, and Electrolyte are placed 4. Wooden case 5. Cell Connectors, and Terminals 6. Electrolyte Most battery diseases are contagious, and if one part fails, some of the other parts are Affected. These diseases may best be considered in the order in which the parts are given in the foregoing list. PLATE TROUBLES Plates are the "vitals" of a battery, and their troubles affect the life of the battery more seriously than those of the other parts. It is often difficult to diagnose their troubles, and the following descriptions are given to aid in the diagnosis. Sulphation 1. Over discharge. Some battery men say that a battery is suflphated whenever anything is wrong with it. Sulphation is the formation of lead sulphate on the plates. As a battery of the lead acid type discharges, lead sulphate must form. There can be no discharge of such a battery without the formation of lead sulphate, which is the natural product of the chemical reactions by virtue of which current may be drawn from the battery. This sulphate gradually replaces the lead peroxide of the positive plate, and the spongy lead of the negative plate. When a battery has been discharged until the voltage per cell has fallen to the voltage limits, considerable portions of the lead peroxide and spongy lead remain on the plates. The sulphate which is then present is in a finely divided, porous condition, and can readily be changed back to lead peroxide and spongy lead by charging the battery. If the discharge is continued after the voltage has fallen to the voltage limits, an excessive amount of sulphate forms. It fills up the pores in the active materials, and covers up much of the active material which remains, so that it is difficult to change the sulphate back to active material. Moreover, the expansion of active material which takes place as the sulphate forms is then so great that it causes the active material to break off from the plate and drop to the bottom of the jar. 2. Allowing a Battery to Stand Idle. When lead sulphate is first formed, it is in a finely divided, porous condition, and the electrolyte soaks through it readily. If a battery which has been discharged is allowed to stand idle without being charged, the lead sulphate crystals grow by the combination of the crystals to form larger crystals. The sulphate, instead of having a very large surface area, upon which the electrolyte may act in changing the sulphate to active material, as it does when it is first formed, now presents only a very small surface to the electrolyte, and it is therefore only with great difficulty that the large crystals of sulphate are changed to active material. The sulphate is a poor conductor, and furthermore, it covers up much of the remaining active material so that the electrolyte cannot reach it. A charged battery will also become sulphated if allowed to stand idle, because it gradually becomes discharged, even though no wires of any kind are attached to the battery terminals. How this takes place is explained later. The discharge and formation of sulphate continue until the battery is completely discharged. The sulphate then gradually forms larger crystals as explained in the preceding paragraph, until all of the active material is either changed to sulphate, or is covered over by the sulphate so that the electrolyte cannot reach it. The sulphate thus forms a high resistance coating which hinders the passage of charging current through the battery and causes heating on charge. It is for this reason that sulphated plates should be charged at a low rate. The chemical actions which are necessary to change the sulphate to active material can take place but very slowly, and thus only a small current can be absorbed. Forcing a large current through a sulphated battery causes heating since the sulphate does not form uniformly throughout the plate, and the parts which are the least sulphated will carry the charging current, causing them to become heated. The heating damages the plates and separators, and causes buckling, as explained later. If batteries which have been discharged to the voltage limits are allowed to stand idle without being charged, they will, of course, continue to discharge themselves just as fully charged batteries do when allowed to stand idle. 3. Starvation. If a battery is charged and discharged intermittently, and the discharge is greater than the charge, the battery will never be fully charged, and lead sulphate will always be present. Gradually this sulphate forms the large tough crystals that cover the active material and remove it from action. This action continues until all parts of the plate are covered with the crystalline sulphate and we have the same condition that results when a battery is allowed to stand idle without any charge. 4. Allowing Electrolyte to Fall Below Tops of Plates. If the electrolyte is allowed to fall below the tops of the plates, so that the active materials are exposed to the air, the parts thus exposed will gradually become sulphated. The spongy lead of the negative plate, being in a very finely divided state, offers a very large surface to the oxygen of the air, and is rapidly oxidized, the chemical action causing the active material to become hot. The charging current, in passing through the parts of the plates not covered by the electrolyte also heats the active materials. The electrolyte which occasionally splashes over the exposed parts of the plates and which rises in the pores of the separators, is heated also, and since hot acid attacks the active materials readily, sulphation takes place quickly. The parts above the electrolyte, of course, cannot be charged and sulphate continues to form. Soon the whole exposed parts are sulphated as shown in Fig. 209. As the level of the electrolyte drops, the electrolyte becomes stronger, because it is only the water which evaporates, the acid remaining and becoming more and more concentrated. The remaining electrolyte and the parts of the plates covered by it become heated by the current, because there is a smaller plate area to carry the current, and because the resistance of the electrolyte increases as it grows more concentrated. Since hot acid attacks the active materials, sulphation also takes place in the parts of the plates still covered by the electrolyte. The separators in a battery having the electrolyte below the tops of the plates suffer also, as will be explained later. See page 346. 5. Impurities. These are explained later. See page 76. 6. Adding Acid Instead of Water. The sulphuric acid in the electrolyte is a heavy, oily liquid that does not evaporate. It is only the water in the electrolyte which evaporates. Therefore, when the level of the electrolyte falls, only water should be added to bring the electrolyte to the correct height. There are, however, many car owners who still believe that a battery may be charged by adding acid when the level of the electrolyte falls. Batteries in which this is done then contain too much acid. This leads to two troubles. The first is that the readings taken with a hydrometer will then be misleading. A specific gravity of 1.150 is always taken to indicate that a battery is discharged, and a specific gravity of 1.280 that a battery is charged. These two values of specific gravity indicate a discharged and charged condition of the battery ONLY WHEN THE PROPORTION OF ACID IN THE ELECTROLYTE IS CORRECT. It is the condition of the plates, and not the specific gravity of the electrolyte which determines when a battery is either charged or discharged. With the correct proportion of acid in the electrolyte, the specific gravity of the electrolyte is 1.150 when the plates are discharged and 1.280 when the plates are charged, and that is why specific gravity readings are generally used as an indication of the condition of the battery. If there is too much acid in the electrolyte, the plates will be in a discharged condition before the specific gravity of the electrolyte drops to 1.150, and will not be in a charged condition until after the specific gravity has risen beyond the usual value. As a result of these facts a battery may be over-discharged, and never fully charged, this resulting in the formation of sulphate. The second trouble caused by adding acid to the electrolyte is that the acid will then be too concentrated and attacks both plates and separators. This will cause the plates to become sulphated, and the separators rotted. 7. Overheating. This was explained in Chapter 9. See page 66. Buckling Buckling is the bending or twisting of plates due to unequal expansion of the different parts of the plate, Figs. 207 and 208. It is natural and unavoidable for plates to expand. As a battery discharges, lead sulphate forms. This sulphate occupies more space than the lead peroxide and spongy lead, and the active materials expand. Heat expands both active materials and grids. As long as all parts of a plate expand equally, no buckling will occur. Unequal expansion, however, causes buckling. 1. Over discharge. If discharge is carried too far, the expansion of the active material on account of the formation of lead sulphate will bend the grids out of shape, and may even break them. 2. Continued Operation with Battery in a Discharged Condition. When a considerable amount of lead sulphate has, formed, and current is still drawn from the battery, those portions of the plate which have the least amount of sulphate will carry most of the current, and will therefore become heated and expand. The parts covered with sulphate will not expand, and the result is that the parts that do expand will twist the plate out of shape. A normal rate of discharge may be sufficient to cause buckling in a sulphated plate. 3. Charging at High Rates. If the charging rate is excessive, the temperature will rise so high that excessive expansion will take place. This is usually unequal in the different parts of the plate, and buckling results. With a battery that has been over discharged, the charging current will be carried by those parts of the plates which are the least sulphated. These parts will therefore expand while others will not, and buckling results. 4. Non-Uniform Distribution of Current Over the Plates. Buckling may occur in a battery which has not been over-discharged, if the current carried by the various parts of the plate is not uniform on account of faulty design, or careless application of the paste. This is a fault of the manufacturers, and not the operating conditions. 5. Defective Grid Alloy. If the metals of which the grids are composed are not uniformly mixed throughout the plate, areas of pure lead may be left here and there, with air holes at various points. The electrolyte enters the air holes, attacks the lead and converts the grid partly into active material. This causes expansion and consequent distortion and buckling. Buckling will not necessarily cause trouble, and batteries with buckled plates may operate satisfactorily for a long time. If, however, the expansion and twisting has caused much of the active material to break away from the grid, or has loosened the active material from the grids, much of the battery capacity is lost. Another danger is that the lower edges of a plate may press against the separator with sufficient force to cut through it, touch the next plate, and cause a short-circuit. Shedding, or Loss of Active Material The result of shedding, provided no other troubles occur, is simply to reduce the capacity of the plates. The positives, of course, suffer more from shedding than the negatives do, shedding being one of the chief weaknesses of the positives. There is no remedy for this condition. When the shedding has taken place to such an extent that the capacity of the battery has fallen very low, new plates should be installed. After a time, the sediment space in the bottom of the jar becomes filled with sediment, which touches the plates. This short-circuits the cell, of course, and new plates must be installed, and the jars washed out thoroughly. 1. Normal Shedding. It is natural and unavoidable for the positives to shed. Lead Peroxide is a powder-like substance, the particles of which do not hold together. A small amount of sulphate will cement the particles together to a considerable extent. At the surface of the plate, however, this sulphate is soon changed to active material, and the peroxide loses its coherence. Particles of peroxide drop from the plates and fall, into the space in the bottom of the jar provided for this purpose. Bubbles of gas which occur at the end of a charge blow some of the peroxide particles from the plate. The electrolyte moving about as the battery is jolted by the motion of the car washes particles of peroxide from the positive plates. Any slight motion between positive plates and separators rubs some peroxide from the plates. It is therefore entirely natural for shedding to occur, especially at the positives. The spongy lead of the negatives is much more elastic than the peroxide, and hence very little shedding occurs at the negative plates. The shedding at the positives explains why the grooved side of the separator is always placed against the positive plate. The grooves, being vertical, allow the peroxide to fall to the bottom of the jar, where it accumulates as sediment, or "mud." 2. Excessive Charging Rate, or Overcharging. If a battery is charged at too high a rate, only part of the current is used to produce the chemical actions by which the battery is charged. The balance of the current decomposes the water of the electrolyte into hydrogen and oxygen, causing gassing. As the bubbles of gas force their way out of the plates, they blow off particles of the active material. When a battery is overcharged, the long continued gassing has the same effect as described in the preceding paragraph. 3. Charging Sulphated Plates at too High a Rate. In sulphated plates, the chemical actions which take place as a battery is charged can proceed but very slowly, because the sulphate, besides being a poor conductor, has formed larger crystals which present only a small surface for the electrolyte to act upon, and has also covered up much of the remaining active material. Since the chemical actions take place slowly, the charging current must be kept at a low value. If too heavy a charging current is used, the battery will be overheated, and some of the current will simply cause gassing as explained in No. 2 above. The gas bubbles will break off pieces of the sulphate, which then fall to the bottom of the jars as "mud." 4. Charging Only a Part of the Plate. If the electrolyte falls below the tops of the plates, and the usual charging current is sent into the battery, the current will be too great for the plate area through which it passes, and hence gassing and shedding will result as already explained. The same condition exists in a battery in which one or more plates have been broken from the strap, either because of mechanical vibration or because of impurities such as acetic acid in improperly treated separators. The remaining plates are called upon to do more work, and carry the entire charging current. Gassing and shedding will result. 5. Freezing. If a battery is given any care whatever, there is little danger of freezing. The electrolyte of a fully charged battery with a specific gravity of 1.280 freezes at about 92° below zero. With a specific gravity of 1.150, the electrolyte freezes at about 5° above zero. A frozen battery therefore indicates gross neglect. As the electrolyte freezes, the water of the electrolyte expands. Since there is electrolyte in all the inner parts of the plate, the expansion as the water in the paste freezes forces the pastes out of the grids. The expansion also cracks the rubber jars, and sometimes bulges out the ends of the battery case. Loose Active Material This refers to a condition in which the active materials are no longer in contact with the grid. Corrosion, or sulphation, of the grids themselves is generally present at the same time, since the chemical actions are shifted from the active material to the grids themselves. 1. Over discharge. As a battery discharges, the lead sulphate which forms causes an expansion of the active material. If a battery is repeatedly over-discharged, this results in the positives shedding. In the negatives, the spongy lead is puffed out, resulting in the condition known as "bulged negatives" as illustrated in Fig 122. 2. Buckling. As a plate grid is bent out of shape, the active material, especially the peroxide, breaks loose from the grid, since the peroxide cannot bend as much as the grids. This occurs in the negatives also, though not to such an extent as in the positives. If the plates are buckled to such an extent that the element will not go back into the jar, the positives should be discarded. If the positives are buckled, the negatives will be also, but not to the extent that the positives are. In the case of the positives, there is no remedy, and the plates should be discarded. The negatives, however, may be fully charged, and then straightened, and the active material forced back flush with the grids by pressings, as described in Chapter 15. Impurities Impurities may be divided into two general classes. The first class includes those which do not attack the separators or grids, but merely cause internal self-discharge. The second class includes those which attack the grids or separators. 1. Impurities Which Merely Cause Self-discharge. This includes metals other than lead. If these metals are in solution in the electrolyte, they deposit on the negative plate, during charge, in their ordinary metallic state, and form small cells with the spongy lead. These small cells discharge as soon as the charging circuit is opened, and some of the lead is changed to lead sulphate. This, of course, causes a loss in capacity. Free hydrogen is given off by this local discharge, and so much of it is at times given off that the hydrogen bubbles give the electrolyte a milky appearance. Silver, gold, and platinum are the most active in forming small local cells. These metals form local cells which have comparatively high voltages, and which take away a considerable portion of the energy of a cell. Platinum is especially active, and a small amount of platinum will prevent a negative plate from taking a charge. Gradually, however, the spongy lead covers up the foreign metal and prevents it from forming local cells. Iron also forms local cells which rob the cell of a considerable portion of its capacity. This may be brought into the cell by impure acid or water. Iron remains in solution in the electrolyte, and is not precipitated as metallic iron. The iron in solution travels from the positive to the negative plate, and back again, causing a local discharge at each plate. It is, moreover, very difficult to remove the iron, except by pouring out all of the electrolyte. Manganese acts the same as the iron. 2. Impurities Which Attack the Plates. In general, this class includes acids other than sulphuric acid, compounds formed from such acids, or substances which will readily form acids by chemical action in the cell. Nitric acid, hydrochloric or muriatic acid, and acetic acid belong in this class of impurities. Organic matter in a state of decomposition attacks the lead grids readily. Impurities in the second class dissolve the lead grids, and the plate disintegrates and falls to pieces, since its backbone is destroyed. When a battery which contains these impurities is opened, it will be found that the plates crumble and fall apart at the slightest touch. See Fig. 210. Separators which have not been treated properly introduce acetic acid into a cell. The acetic acid attacks and rots the lead, especially the lugs projecting above the electrolyte, and the plate connecting straps. The plates will generally be found broken from the connecting strap, with the plate lugs broken and crumbled. As for remedies, there is not much to be done. Impurities in the first class merely decrease the capacity of the battery. If the battery is fully charged, and the negatives then washed thoroughly, some of the impurities may be removed. Impurities of the second class have generally damaged the plates beyond repairs by the time their presence is suspected. The best thing to do is to keep impurities out of the battery. This means that only distilled water, which is known to be absolutely free from impurities should be used. Impurities which exist in the separators or acid cannot be detected readily, but in repairing a battery, separators furnished by one of the reliable battery makers should be used. Pure acid should also be used. This means that only chemically pure, or "C. P." acid, also known as battery acid should be used. In handling the acid in the shop, it should always be kept in its glass bottle, and should be poured only into a glass, porcelain, earthenware, lead, or rubber vessel. Never use a vessel made of any other material. Corroded Grids When the grids of a plate are attacked chemically, they become thin and weak, and may be spoken of as being corroded. 1. Impurities. Those impurities which attack the lead grids, such as acids other than sulphuric acid, compounds formed from these acids, or substances which will readily form acids dissolve some of the lead which composes the grids. The grids gradually become weakened. The decrease in the amount of metal in the grids increases the internal resistance of the cell and give a tendency for temperatures to be higher in the cell. The contact between grids and active material is in time made poor. If the action of the impurities continues for any length of time, the plate becomes very weak, and breaks at the slightest touch. 2. High Temperatures. Anything that raises the temperature of the electrolyte, such as too high a charging rate, causes the acid to attack the grids and form a layer of sulphate on them. The sulphate is changed to active material on charge, and the grids are thereby weakened. 3. Age. Grids gradually become weak and brittle as a battery remains in service. The acid in the electrolyte, even though the electrolyte has the correct gravity and temperature, has some effect upon the grids, and in time this weakens them. During the life of a battery it is at times subjected to high temperatures, impurities, sulphation, etc., the combined effects of which result in a gradual weakening of the grids. Granulated Negatives 1. Age. The spongy lead of the negative plate gradually assumes a "grainy" or "granulated" appearance. The lead then seems to be made up of small grains, like grains of sand, instead of being a smooth paste. This action is a natural one, and is due to the gradual increase in the size of the particles of the lead. The plate loses its porosity, the particles cementing together and closing the pores in the lead. The increase in the size of the particles of the spongy lead decreases the amount of surface exposed to the action of the electrolyte, and the plate loses capacity. Such plates should be thrown away, as charging and discharging will not bring the paste back to its original state. 2. Heat will also cause the paste to become granulated, and its surface to become rough or even blistered. Heating of Negatives Exposed to the Air When charged negatives are exposed to the air, there is a decided increase in their temperature. Spongy lead is in an extremely finely divided state, the particles of lead being very minute, and forming a very porous mass. When the plate is exposed to the air, rapid oxidation takes place because the oxygen of the air has a very large surface to act upon. The oxidation causes the lead to become heated. The heating, of course, raises the temperature of the electrolyte, and the hot acid attacks both grids and lead. Fully charged negatives should therefore be watched carefully when removed from a battery. When they become heated and begin to steam, they should be dipped in water until they have cooled. They may then be removed from the water, but should be dipped whenever they begin to steam. After they no longer heat, they may be left exposed to the air. This method of dipping the negatives to prevent overheating has always been followed. However, the Electric Storage Battery Company, which makes the Exide batteries, does not take any steps to prevent the heating of the negatives when exposed to the air, stating that their plates are not injured by the heating which takes place. Negatives With Very Hard Active Material This is the characteristic condition of badly sulphated negatives. The active material may be as hard as a stone. The best method of treating such negatives is to charge them in distilled water. See Chapter 15. Bulged Negatives This is a characteristic of a repeatedly over-discharged negative. The lead sulphate which forms as a battery discharges is bulkier than the spongy lead, and the lead expands and bulges out between the ribs of the grid. Negative With Soft, Mushy Active Material 1. High Gravity. Gravity above 1.300 causes the acid to act upon the spongy lead and soften it. 2. Heat will soften the spongy lead also. The softened spongy lead is loosened and falls from the grids, as shown in Fig. 211. Little can be done for such negatives. Negatives With Roughened Surface This is caused by slight overheating, and is not a serious condition. Frozen Positives A battery which is allowed to stand in a cold place while completely discharged will freeze. The water in the electrolyte expands as it freezes, cracking the rubber jars and bulging out the end of the wooden case. As the electrolyte which fills the pores of the positive plates freezes and expands, it breaks the active material loose from the grids. When the battery thaws, the active material does not go back into the grids. When such a battery is opened, and the groups separated, the positive active material sticks to the separators in large pieces, Fig. 112, and that remaining in the grids falls out very easily. The active material has a pinkish color and is badly shrunken. Rotted, Disintegrated Positives 1. Impurities. This has already been discussed. See page 76. 2. Overheating. The hot electrolyte dissolves the lead of the grids and that which is dissolved is never converted back to lead. Continued overheating wears out the grids, and the active material also, and the plate falls to pieces at the slightest pressure. 3. Age. Positives gradually disintegrate due to the prolonged action of the electrolyte on the grids, an occasional overheating, occasional use of impure water, etc. Positives which are rotted and disintegrated are, of course, hopeless, and must be junked. Buckled Positives As previously described, buckling is caused by unequal expansion. If the buckling is only slight, the plates may be used as they are. If the plates are badly buckled, the active material will be found to be loose, and the plates cannot be straightened. Such positives should be discarded. Positives That Have Lost Considerable Active Material This is the result of continued shedding, the causes of which have already been given. If the shedding is only slight, and the plate is good otherwise, it may be used again. If such active material has been lost, the plates must be discarded. Positives With Soft Active Material Continued operation at high temperatures, will soften the peroxide, and make the plates unfit for further use. Old positives are soft, clue to the natural deterioration of the paste with age. Positives With Hard, Shiny Active Material This condition is found in batteries that have been charged with the acid below the tops of the plates. The part of the plate above the acid is continually being heated by the charging current. It becomes hard and shiny, and has cracks running through it. The peroxide becomes orange or brick colored, and the grid deteriorates. The part of the plate below the electrolyte suffers also, as explained more fully on page 71. Such plates should be discarded if any considerable portion of the plates is affected. Plates in which 1/2 to 1 inch of the upper parts are affected may be used again if otherwise in good condition. Plates Which Have Been Charged in Wrong Direction Such plates have been partly reversed, so that there is lead peroxide and spongy lead on both positive and negative plates, and such plates are generally worthless. If the active materials have not become loosened from the grids, and the grids have not been disintegrated and broken, the plates may sometimes be reversed by a long charge at a low rate in the right direction. If this does not restore the plates, discard them. SEPARATOR TROUBLES Separators form the weakest part of a battery, but at the same time perform a very important duty. New separators should therefore be installed whenever a battery is opened for repairs. Repairs should never be attempted on separators. 1. Not Properly Expanded Before Installation. Separators in stock must be kept moist. This not only prevents them from becoming dry and brittle, but keeps them fully expanded. If separators which have been kept dry in stock are installed in a battery, they do their expanding inside the battery. This causes them to project beyond the edges of the plates. The crowding to which they are subjected causes them to crack. Cracked separators permit "treeing" between plates, with a consequent short circuit. 2. Not Properly Treated. Separators which have not been given the proper chemical treatment are likely to develop Acetic acid after they are in the battery. Acetic acid dissolves the lead grids, the plate lugs, and the plate connecting straps rapidly. If the plate lugs are found broken, and crumble easily, acetic acid is very likely present, especially if an odor like that of vinegar is noticeable. Improperly treated separators will cause a battery to show low voltage at high rates of discharge, particularly in cold weather, and will also cause the negatives to give poor cadmium readings, which may lead the repairman to conclude that the negatives are defective. The separators of batteries which have been shipped completely assembled without electrolyte and with moistened plates and separators will sometimes have the same effect. 3. Cracked. Separators should be carefully "candled"--placed in front of a light and looked through. Cracks, resinous streaks, etc., mean that the separator should not be used, as it will breed trouble. 4. Rotted and Carbonized. This may be the result of old age, overheating, or high gravity electrolyte. 5. Pores Clogged. Impurities, dirt from impure water, and lead sulphate fill the pores of a separator and prevent the proper circulation of the electrolyte. The active material of frozen positives also fills up the pores of a separator. 6. Edges Chiseled Off. A buckling plate will cut through the lower edge of a separator and short circuit the cell. Holes will be cut through any part of a separator by a buckling plate, or a negative with bulged active material. JAR TROUBLES Battery jars are made of hard rubber, and are easily broken. They are not acted upon by the electrolyte, or any of the impurities which may be found in the jar. Their troubles are all mechanical, and consist of being cracked, or having small holes through the walls. Jars are softened by high temperatures, but this does no particular harm unless they are actually burned by an open flame or red hot metal. The causes of jar troubles are as follows: 1. Rough Handling. By far the most common cause of jar breakage is rough handling by careless or inexperienced persons. If one end of a battery rests on the floor, and the other is allowed to drop several inches, broken jars will probably result from the severe impact of the heavy lead plates. Storage batteries should be handled as if made of glass. When installed on a car, the springs protect the battery from shock to a considerable extent, but rough roads or exceptionally severe jolts may break jars. 2. Battery Not Properly Fastened. In this case a battery is bumped around inside the battery compartment, and damage is very likely to result. 3. Any Weight Placed on Top of the Battery is transmitted from the links to the plates, and by them to the bottom of the jars. Batteries should always be stored in racks, and not one on top of another. The practice of putting any weight whatever on top of a battery should be promptly discouraged. 4. Freezing. This condition has already been explained. It causes a great many broken jars every winter. 5. Groups Not Properly Trimmed. The outside negative plates in a cell come just inside the jar, and the strap ends must be carefully trimmed off flush with the plates, to prevent them from breaking the top of the jars. Jars have slightly rounded corners, and are somewhat narrower at the extreme ends than nearer the center. A group may therefore go into a jar quite readily when moved toward the other end of the jar to that into which the post strap must go when in proper position for the cover. When the group is forced back into its proper position the strap may break the jar. It is a good plan not only to trim the ends of the negative straps perfectly flush, but to round the strap corners where they go into the jar corners. 6. Defective Jars. (a) A jar not properly vulcanized may come apart at the scam. (b) A small impurity in the rubber may dissolve in the acid and leave a minute pinhole. All jars are carefully tested at the factory and the likelihood of trouble from defective jars is extremely small. 7. Explosion in Cell. (a) Hydrogen and oxygen gases evolved during charging make a very explosive mixture. An open flame brought near a battery on charge or freshly charged, will probably produce an explosion resulting in broken jars and jar covers. (b) An open circuit produced inside a cell on charge in the manner described on page 86 under the heading "Open Circuits," will cause a spark at the instant the circuit is broken, with the same result as bringing a flame near the battery. (c) The small holes in the vents must be kept free for the escape of the gases. These holes are usually sealed in batteries shipped with moistened plates and separators, to keep air out of the cells. The seals must be removed when the battery is prepared for service. If the vents remain plugged, the pressure of the gases formed during charge will finally burst the covers of jars. BATTERY CASE TROUBLE 1. Ends Bulged Out. This may be due to a battery having been frozen or to hold-downs being screwed down too tight, or some similar cause. Whether the case can be repaired depends on the extent of the bulging. This can best be determined by the repairman. 2. Rotted. If the case is rotted around the top, it is evidence that: (a) Too much water was added, with subsequent overflowing when electrolyte warmed up during charge. (b) The tops were poorly sealed, resulting in leaks between the covers and the jars. (c) Battery has not been fastened down properly, and acid has been thrown out of the jars by the jolting of the car on the road. (d) The vent plugs have not been turned down tightly. (e) Electrolyte has been spilled in measuring specific gravity. If the case is rotted around the lower part it indicates that the jars are cracked or contain holes. Instructions for making repairs on battery cases are given on page 360. TROUBLE WITH CONNECTORS AND TERMINALS 1. Corroded. This is a very common trouble, and one which should be guarded against very carefully. Corrosion is indicated by the presence of a grayish or greenish substance on the battery terminals, especially the positive. It is due to several causes: (a) Too much water added to cells. The electrolyte expands on charge and flows out on the top of the battery. (b) Battery not fastened firmly. The jolting caused by the motion of the car on the road will cause electrolyte to be thrown out of the vent caps. (c) Battery poorly sealed. The electrolyte will be thrown out on the cover by the motion of the car through the leaks which result from poor sealing. (d) Vent caps loose. This also allows electrolyte to be thrown out on the battery top. (e) Electrolyte spilled on top of battery in measuring specific gravity. (f) Battery cables damaged, or loose. The cables attached to the battery terminals are connected to lugs which are heavily coated with lead. The cables are insulated with rubber, upon which sulphuric acid has no effect. Care should be taken that the lead coating is not worn off, and that the rubber insulation is not broken or cut so as to allow electrolyte, which is spilled on the battery top as explained in (a), (b), (c), (d) and (e), to reach the bare copper conductors of the cable. The terminal parts are always so made that when the connections are kept tight no acid can come into contact with anything but lead and rubber, neither of which is attacked by sulphuric acid. (g) Attaching wires directly to battery terminals. There should be no exposed metal except lead at the battery terminals. No wires of any other metal should be attached to the battery terminals. Such wires should be connected to the rubber covered cables which are attached to battery, and the connections should be made far enough away from the battery to prevent electrolyte from coming in contact with the wire. Car manufacturers generally observe this rule, but the car owner may, through ignorance, attach copper wires directly to the battery terminals. The positive terminal is especially subject to corrosion, and should be watched carefully. To avoid corrosion it is necessary simply to keep the top of the battery dry, keep the terminal connections tight, and coat the terminals with vaseline. The rule about connecting wires directly to the battery terminals must of course be observed also. 2. Loose. Loose terminal connections cause a loss of energy due to their resistance, and all such connections must be well made. If the inter-cell connectors are loose, it is due to a poor job of lead burning. This is also true of burned on terminals, and in either case, the connections should be drilled off, cleaned and re-burned. Terminals sometimes become so badly corroded that it is impossible to disconnect the cables front the battery. Stitch terminals should be drilled off and soaked in boiling soda water. ELECTROLYTE TROUBLES (1) Low Gravity. See page 321. (2) High Gravity. See page 323. (3) Low Level. See page 323. (4) High Level. This condition is due to the addition of too much water. It leads to corrosion as already explained. It also causes a loss of acid. The Electrolyte which overflows is lost, this of course, causing a loss of acid. The condition of Low Gravity then arises, as described on page 321. (5) Specific gravity will not rise during charge. See page 204. (6) Milky Electrolyte: (a) Lead Sulphate in Battery Acid. It sometimes happens that sulphuric acid contains some lead sulphate in solution. This sulphate is precipitated when water is added to the acid in mixing electrolyte, and gives the electrolyte a milky appearance. This sulphate settles if the electrolyte is allowed to stand. (b) Gassing. The most common cause of the milky appearance, however, is the presence of minute gas bubbles in large quantities. These may be the result of local action caused by the presence of metallic impurities in the battery. The local action will stop when the battery is put on charge, but will begin as soon as the battery is taken off charge. The impurities are gradually covered by lead or lead sulphate, and the local action is thus stopped. Excessive gassing in a cell which contains no impurities may also cause the electrolyte to have a milky appearance. The gas bubbles are very numerous and make the electrolyte look milky white. (c) Impurities in the electrolyte will also give it a milky appearance. GENERAL TROUBLES Open Circuits 1. Poor Burning of Connectors to Posts. Unless a good burned connection is made between each connector and post, the joint may melt under high discharge rates, or it may offer so much resistance to the passage of current that the starting motor cannot operate. Sometimes the post is not burned to the connector at all, although the latter is well finished off on top. Under such conditions the battery may operate for a time, due to frictional contact between the post and connector, but the parts may become oxidized or sulphated, or vibration may break the connection, preventing the flow of current. Frequently, however, the circuit is not completely open, and the poor connection acts simply as a high resistance. Under such a condition the constant current generator automatically increases its voltage, and forces charging current through the battery, although the latter, having only a low fixed voltage, cannot force out the heavy current required for starting the engine. 2. Terminals Broken Off. Inexperienced workmen frequently pound on the terminals to loosen the cable lugs, or pry on them sufficiently to break off the battery terminals. If the terminals and lugs are kept properly greased, they will come apart easily. A pair of terminal tongs is a very convenient tool. These exert a pressure between the terminal and the head of the terminal screw, which is first unscrewed a few turns. 3. Acid on Soldered Joints. Amateurs sometimes attempt to make connections by the use of a soldering iron and solder. Solder is readily dissolved by acid, not only spoiling the joint, but endangering the plates if any gets into the cells. Solder must never be used on a battery except for sweating the cables into the cable lugs, and the joint even here must be well protected by rubber tape. 4. Defective Posts. Posts withdrawn from the post mould before they are cool enough may develop cracks. Bubbles sometimes occur in the posts. Either trouble may reduce the current carrying capacity or mechanical strength of the post and result in a broken or burned-out spot. 5. Plates Improperly Burned. As previously explained, this is not likely to cause immediate trouble, but by imposing extra work on the balance of the plates, causes them to wear out quickly. Battery Discharged 1. Due to excessive use of starting motor and lamps. 2. Failure of generator. 3. Defective switches, which by being grounded, or failing to open allow battery to discharge. 4. Defective cutout, allowing battery to discharge into generator. 5. Addition of accessories, or use of too large lamps. 6. Defective wiring, causing grounds or short-circuits. 7. Insufficient charging rate. 8. Battery allowed to remain idle. Dead Cells 1. Worn out Separators. The duties of separators are to prevent the plates from touching each other, and to prevent "treeing," or growth of active material from the negative to the positive plates. If they fail to perform these duties, the battery will become short-circuited internally. The separator troubles described on page 81 eventually lead to short-circuited cells. 2. Foreign Material. If a piece of lead falls between plates so as to later punch a hole through a separator, a short circuit will result. Great care should be taken in burning plates on the straps to prevent lead from running down between plates, as this lead will cause a short circuit by punching through the separator. 3. Accumulation of Sediment. The active material which drops from the plates accumulates in the "mud" space in the bottom of the jar. If this rises until it touches the bottom of the plates, a short-circuit results. Usually it is advisable to renew the positives in a battery which has become short-circuited by sediment, since the sediment comes largely from the positives, and if they have lost enough active material to completely fill the sediment space, they are no longer fit for use. 4. Badly sulphated plates and separators, impurities which attack the plates. Loss of Capacity A battery loses capacity due to a number of causes. Some of them have already been considered. 1. Impurities in the Electrolyte. These have already been discussed. 2. Sulphation. This also has been described. 3. Loose Active Material, as already described. The active materials which are not in contact with the grids cannot do their work. 4. Incorrect Proportions of Acid and Water in the Electrolyte. In order that all the active material in the plates may be utilized, there must be enough acid in the electrolyte, and also enough water. If there is not enough acid, the battery will lack capacity. If there is too much acid, the acid when the battery is fully charged will be strong enough to attack and seriously damage the plates and separators. Insufficient amount of acid may be due to replacing, with water, electrolyte which has been spilled or which has leaked out. Too much acid results from an incorrect proportion of acid and water in the electrolyte, or from adding acid instead of water to bring the electrolyte above the plate tops, and causes sulphation, corroded plates, and carbonized separators. The remedy for incorrect proportions of acid and water in the electrolyte is to give the battery a full charge and adjust the gravity by drawing off some of the electrolyte and replacing it with water, or 1.400 specific gravity electrolyte, as the case may require. 5. Separators Clogged. The pores of the separators may become filled with sulphate or impurities, and thus prevent the proper circulation of the electrolyte. New separators must be put in. 6. Shedding. The capacity of a battery naturally decreases as the active material falls from the plates, since the amount of active material which can take part in the chemical actions that enable us to draw current from the battery decreases. 7. Low Level of Electrolyte. Aside from the loss of capacity which results from the sulphation caused by low electrolyte, there is a loss of capacity caused by the decrease in the useful plate area when the electrolyte is below the tops of the plates. Only that part of the plate surface which is below the electrolyte does any work, and the area of this part gradually decreases as the electrolyte falls. 8. Reversal of Plates. If one cell of a battery has an internal short circuit, or some other defect which causes it to lose its charge, the cell will be discharged before the others which are in series with it, and when this cell is completely discharged, the other cells will send a current through it in a discharge direction, and the negative plates will have a coating of lead peroxide formed on them, and will assume the characteristics of positive plates. The positives will be reversed also. This reversal may also be the result of charging a battery in the wrong direction, on account of reversed charging connections. The remedy for reversed plates, provided they have not become disintegrated, is to give them a long charge in the right direction at a low rate. 9. Effect of Age. A battery gradually loses capacity due to its age. This effect is independent of the loss of capacity due to the other causes. In the negatives, the size of the grain increases its size, giving the plates a granulated appearance. Stitch plates are called "granulated" negatives. The spongy lead cements together and loses porosity. Loss of Charge in An Idle Battery It has been found that if a charged battery is allowed to stand idle, and is not charged, and no current is drawn from it, the battery will gradually become completely discharged and must be given an occasional "freshening" charge. Now, as we have learned, when a battery discharges lead sulphate forms on each plate, and acid is taken from the electrolyte as the sulphate forms. In our idle battery, therefore, such actions must be taking place. The only difference in this case is that the sulphate forms without any current passing through the battery. At the lead peroxide plate we have lead peroxide paste, lead grid, and sulphuric acid. These are all the element-, needed to produce a storage battery, and as the lead peroxide and the lead are touching each other, each lead peroxide plate really forms a short circuited cell. Why does this plate not discharge itself completely? A certain. amount of discharge does take place, and results in a layer of lead sulphate forming between the lead peroxide and the grid. The sulphate, having high resistance then protects the lead grid and prevents any further action. This discharge action therefore does not continue, but causes a loss of a certain part of the charge. At the negative plate, we have pure spongy lead, and the grid. This grid is not composed entirely of lead, but contains a percentage of antimony, a metal which makes the grid harder and stronger. There is but very little difference of potential between the spongy lead and the grid. A small amount of lead sulphate does form, however, on the surface of the negative plate. This is due to the action between the spongy lead and the electrolyte. Some of the lead combines with the acid to form lead sulphate, but after a small amount has been formed the action is stopped because a balanced chemical condition is soon obtained. Thus only a small amount of lead sulphate is formed at each plate, and the cell thereby loses only a small part of its charge. In a perfectly constructed battery the discharge would then stop. The only further action which would take place would be the slow evaporation of the water of the electrolyte. The loss of charge which actually occurs in an idle charged battery is greater than that due to the formation of the small amounts of sulphate on the plates, and the evaporation of the water from the electrolyte. Does an idle cell discharge itself by decomposing its electrolyte? We have a difference of potential of about two volts between the lead and lead peroxide plate. Why is the electrolyte not decomposed by this difference? At first it might seem that the water and acid should be separated into its parts, and hydrogen liberated at the negative plate. As a matter of fact, very little hydrogen gas is set free in an idle charged cell because to do so would require a voltage of about 2.5. At two volts, so little gas is formed that the loss of charge due to it may be neglected entirely. The greatest loss of charge in an idle battery results from conditions arising from the processes of manufacture, internal troubles, and leakage between terminals. The grids of a cell are an alloy of lead and antimony. These are mixed while in a molten condition, and are then allowed to cool. If the cooling is not done properly, or if a poor grade of antimony is used, the resulting grid is not a uniform mixture of antimony and lead. There will be areas of pure lead, with an air hole here and there. The lack of uniformity in the grid material results in a local discharge in the grid. This causes some loss of charge. If the active material completely fills the spaces between the grids, the acid formed as the cell is charged may not be able to diffuse into the main body of the electrolyte, but forms a small pocket of acid in the plate. This acid will cause a discharge between paste and grid and a coating of lead sulphate forms on the arid, resulting in a certain loss of charge. In general any metallic impurity in a cell will cause a loss at the lead plate. When a cell is charged, the current causes the metals to deposit on the lead plate. Local cells are formed by the metallic impurity, the lead plate, and the acid, and these tiny cells will discharge completely, causing a loss of charge. This has already been described on page 76. Another cause of loss of charge in an idle cell is leakage of current between the terminals on the outside of the battery. During charge, the bubbles of gas which escape from the electrolyte carry with them minute quantities of acid which may deposit on the top of the battery and gradually form a thin conducting layer of electrolyte through which a current will flow from the positive to the negative terminals. This danger may be avoided by carefully wiping any moisture from the battery. Condensation of moisture from the air, on the top or sides and bottom of a battery will cause the same condition. This will be especially noticeable if a battery is kept in a damp place. The tendency for crystals of lead to "tree" over from the negative to the positive plates is well known. An idle battery is one in which this action tends to take place. Treeing will occur through the pores of the separators and as there is no flow of electrolyte in or out of the plates, the lead "trees" are not disturbed in their growth. A freshening charge causes this flow to take place, and break up the "trees" which would otherwise gradually short circuit the cells. ======================================================================== Section II ------------------------------------------------------------------------ Shop Equipment Shop Methods ======================================================================== CHAPTER 11. CARE OF THE BATTERY ON THE CAR. ------------------------------- Any man who goes into the battery repair business will gradually learn by experience what equipment he finds necessary for his work. Some men will be able to do good work with comparatively little equipment, while others will require a somewhat elaborate layout. [Fig 38.] Fig. 38. Typical Work Room Showing Bench About 34 Inches High, Lead Burning Outfit, Hot Plates for Melting Sealing Compound and Hand Drill-Press for Drilling off Inter-Cell Connectors. There are some things, however, which are necessary, and the following lists are given to help the repairman select his equipment. The man with limited capital will be unable to buy a complete equipment at the start, but he should add to his equipment as fast as his earnings will permit. The repairman may be able to "get-by" with crude equipment when his business is very small, but to make his business grow he must absolutely have good equipment. The following list gives the various articles in the order of their importance. The first seven are absolutely necessary, even for the poorest beginner. The others are also essential, but may be bought as soon, as the money begins to come in. Some of the tools must also be bought before opening doors for business, such as the putty knife, screwdrivers, pliers, and so on. Each article, which requires explanation, is described in detail, beginning on page 100. Equipment Which is Absolutely Necessary 1. Charging Outfit, such as a motor-generator set, rectifier, or charging resistance where direct current is available. 2. Charging Bench and Accessories. With the charging bench must go the following: 1. A syringe-hydrometer for measuring specific gravity of electrolyte, for drawing off electrolyte and for adding water to cells. 2. A special battery thermometer for measuring temperature of electrolyte. 3. A voltmeter to measure cell, battery, and cadmium voltages. 4. An ammeter to measure charging current. 5. A glass bottle for distilled water. Also one for electrolyte. 6. A number of eighteen inch lengths of No. 12 flexible wire fitted with lead coated test clips, for connecting batteries in series while on charge. 3. Work bench with vise. 4. Sink or wash tank and water supply. 5. Lead-burning outfit. (This should properly be called a lead welding outfit, since it is used to melt lead parts so that they will be welded together.) 6. For handling sealing compound, the following are necessary. 1. Stove. 2. Pot in which compound is melted. 3. An iron ladle for dipping up the melted compound. 4. One or two old coffee pots for pouring compound. 7. Shelving or racks for batteries waiting to be repaired, batteries which have been repaired, rental batteries, new batteries, battery boxes, battery jars, battery plates, etc. 8. Bins for battery parts, such as covers, inter-cell connectors, plate straps, terminals, handles, vent plugs, hold down bolts, separator hold-downs, and so on. Equipment Needed In Opening Batteries 9. A battery steamer for softening sealing-compound and making covers limp, for softening compound around defective jars which are to be removed, for softening jars which are to be set in a battery box, and so on. 10. Putty knife to remove softened scaling compound. 11. One ratchet brace with set of wood bits or square shank drills of the following sizes: 3/8, 5/8, 3/4, 13/16, and 7/8 inch, for drilling off terminals and inter-cell connectors. A power drill press, or a portable electric drill will save time and labor in drilling off the terminals and connectors. 12. Center punch for marking terminals and connectors before drilling. 13. Ten inch screwdriver for prying off connectors and terminals which have been drilled. The screwdriver may, of course, be used on various other kinds of work also. 14. A ten-inch length of 3/4 inch angle iron to protect upper edge of case when prying off the connectors and terminals which have been drilled. 15. Two pairs of standard combination pliers for lifting elements out of jars. A pair of six or eight inch gas pliers will also do for this work. 16. Machinist hammer. This is, of course, also used for other purposes. 17. Terminal tongs for removing taper lugs from terminals. 18. Pair of long, fiat nosed pliers for pulling out separators and jars. 19. Open-end wrench for use in removing taper lugs from terminals. Equipment for Lead Burning (Welding) In addition to the lead burning-outfit, the following tools are needed: 20. A plate burning rack for setting up plates which are to be burned to a plate strap. 21. A plumber's or tinner's triangular scraper for cleaning surfaces which are to be welded together. A pocketknife will do in a pinch. 22. Steel wire brush for cleaning surfaces which are to be welded together. This may also be used for general cleaning of lead parts. 23. Coarse files, vixen, round, and flat, for filing lead parts. 24. Set of burning, collars to be used in burning inter-cell connectors to posts. 25. Moulds for casting sticks of burning lead. A pot for melting lead is needed with the mould, and mould compound is also needed. 26. Set of post builders-moulds used for building up posts which have been drilled short in removing terminals and intercell connectors. 27. Pair of blue or smoked glasses to be worn when using lead burning outfit. Equipment for General Work on Cell Connectors and Terminals 28. Set of moulds for casting inter-cell connectors, terminals, terminal screws, taper lugs, plate straps and posts, etc. 29. Set of reamers to ream holes in terminals and connectors. 30. Set of hollow reamers for reducing posts. Equipment for Work on Cases 31. Cans of asphaltum paint for painting cases. May also be used for acid-proofing work benches, floor, shelves, charging bench, and so on. 32. Paint brushes, one wide and several narrow. 33. Battery turntable. 34. Several wood chisels of different sizes. 35. Small wood-plane for smoothing up top edges of case. 36. Large glazed earthenware jars of washing or baking soda solution for soaking cases to neutralize acid. Tools and Equipment for General Work 37. One pair of large end cutting nippers for cutting connectors, posts, plate lugs, and so on. 38. One pair of 8 inch side cutting pliers. 39. One pair of 8 inch diagonal cutting pliers. 40. Several screwdrivers. 41. Adjustable hacksaw frame with set of coarse blades. 42. Gasoline torch. 42. Soldering iron, solder and flux. 44. Separator cutter. 45. Plate press for pressing bulged, spongy lead of negative plates flush with surface of grids. 46. Battery carrier. 47. Battery truck. 48. Lead lined box for storing separators. A large glazed earthenware jar may be used for this purpose, and is much cheaper, although it will not hold as many separators, on account of its round shape, as the lead lined box. 49. Several old stew pans for boiling acid soaked terminals, connectors, covers, etc., in a solution of washing soda. 50. Set of metal lettering stamps, for stamping POS and NEG on battery terminals, repairman's initials, date battery was repaired, and nature of repairs, on inter-cell connectors. 51. Cadmium test set. 52. High rate discharge testers. 53. Pair of rubber gloves to protect hands when handling acid. 54. Rubber apron to protect clothing from acid. 55. Pair of rubber sleeve protectors. 56. Rubbers to protect shoes, or pair of low rubber boots. 57. Tags for tagging repair and rental batteries, batteries in storage, etc. 58. Pot of paraffine which may be heated, and paper tags dipped after date has been written on tag in pencil. A 60-watt lamp hung in the can may be used for heating the compound. In this way the tag is protected from the action of acid, and the writing on the tag cannot be rubbed off or made illegible. 59. A number of wooden boxes, about 12 inches long, 8 inches wide, and 4 inches deep, in which are placed terminals, inter-cell connectors, covers, vent plugs, etc., of batteries being repaired. 60. Several large glazed earthenware jars are convenient for waste acid, old separators, and general junk, which would otherwise litter up the shop. Stock 61. A supply of spare parts, such as cases, jars, covers, plate straps, inter-cell connectors, plates, vent plugs, etc., should be kept. 62. A supply of sealing compound is necessary. 63. A carboy of pure acid, and carboys of 1.400 electrolyte ready for use should be on hand. A 16 oz. and a 32 or 64 oz. graduate are very useful in measuring out acid and water. 64. A ten gallon bottle of distilled water is necessary for use in making up electrolyte, for addition to cell electrolyte to bring electrolyte up to proper level, and so on. If you wish to distill water yourself, buy a water still. 65. A supply of pure vaseline is necessary for coating terminals to prevent corrosion. Special Tools Owing to special constructions used oil sonic of the standard makes of batteries, special tools are required, and such tools should be obtained if work is done oil these batteries. Some of these tools are as follows: 66. Special wrenches for turning sealing nuts on Exide batteries. 67. Two hollow reamers (post-freeing tools) for cutting lead seal around posts of Prest-O-Lite batteries. There are two sizes, large and small, see page 389. 68. Style "B" peening press for sealing posts of Prest-O-Lite batteries to covers, see page 390. 69. Pressure tongs for forcing lead collar oil posts of Vesta batteries, see page 415. 70. Special wrench for tightening sealing nut oil Titan batteries. 71. Special reamer for cutting sealing ring oil Universal batteries. The list of special tools is not intended to be complete, and the repairman will probably find other special tools necessary from time to time. In any case, it is best to buy from the battery manufacturer such special tools as are necessary for the batteries that come in for repairs. It is sometimes possible to get along without the special tools, but time and labor will be saved by using them. DESCRIPTIONS OF TOOLS AND EQUIPMENT NAMED IN FOREGOING LIST Charging Equipment A battery is charged by sending a direct current through it, this "charging" current entering the battery at, the positive terminal and passing out at the negative terminal. To send this current through the battery, a voltage of about 7.5 volts is applied to each battery. Two things are therefore necessary in charging a battery: 1. We must have a source of direct current. 2. The voltage impressed across each battery must be, about 2.5 per cell. The charging voltage across each six volt battery must therefore be 7.5, and for each twelve volt battery the charging voltage must be about 15 volts. With the battery on the car, there are two general methods of charging, i. e., constant potential (voltage) and constant current. Generators having a constant voltage regulator have a constant voltage of about 7.5, the charging current depending upon the condition of the battery. A discharged battery thus receives a high charging current, this current gradually decreasing, or "tapering" as the battery becomes more fully charged. This system has the desirable characteristic that a discharged battery receives a heavy charging current, and a fully charged battery receives a small charging current. The time of charging is thereby decreased. With a constant-current charging system, the generator current output is maintained at a certain value, regardless of the state of charge of the battery. The disadvantage of this system is that a fully charged battery is charged at as high a rate and in most cases at a higher rate than a discharged battery. In the shop, either the constant-potential, or the constant-current system of charging may be used. Up to the present time, the constant current system has been used in the majority of shops. The equipment for constant current charging uses a lamp bank or rheostat to regulate the charging current where direct current is available, and a rectifier or motor-generator set where only alternating current is available. Recently, the Hobart Brothers Company of Troy, Ohio, has put on the market a constant potential motor-generator set which gives the same desirable "tapering" charge as does the constant voltage generator on the car. This set will be described later. Where a 110-volt direct current supply is available, fifteen 6-volt batteries may be connected in series across the line without the use of any rheostat or lamp bank, only an ammeter being required in the circuit to indicate the charging current. The charging rate may be varied by cutting out some of the batteries, or connecting more batteries in the circuit. This method is feasible only where many batteries are charged, since not less than fifteen 6-volt batteries may be charged at one time. Constant Current Charging Using Lamp Banks, or Rheostats Figures 39 and 40 show the wiring for a "bank" of twenty 100-watt lamps for battery charging from a 110 volt line. Figure 39 shows the wiring to be used when the positive side of the line is grounded, while Figure 40 shows the wiring to be used when the negative side of the line is grounded. In either case, the "live" wire connects to the lamp bank. The purpose of this is to eliminate the possibility of a short-circuit if any part of the charging line beyond the lamp bank is accidentally grounded. [Fig. 39 Lamp bank for charging from a 110 volts, D.C. Line (positive grounded)] [Fig. 40 Lamp bank for charging from a 110 volts, D.C. Line (negative grounded)] [Fig. 41 Rheostat for charging from a 110 volts, D.C. Line (positive grounded)] [Fig. 42 Rheostat for charging from a 110 volts, D.C. Line (negative grounded)] Figures 41 and 42 show the wiring of two charging rheostats which may be used instead of the lamp banks shown in Figures 39 and 40. In these two rheostats the live wire is connected to the rheostat resistances in order to prevent short-circuits by grounding any part of the circuit beyond the rheostats. These rheostats may be bought ready for use, and should not be "homemade." The wiring as shown in Figures 41 and 42 is probably not the same as will be found on a rheostat which may be bought, but when installing a rheostat, the wiring should be examined to make sure that the "live" wire is connected to the rheostat resistance and does not connect directly to the charging circuit. If necessary, change the wiring to agree with Figures 41 and 42. Figures 43 and 44 show the wiring of the charging circuits. In Figure 43 each battery has a double pole, double throw knife switch. This is probably the better layout, since any battery may be connected in the circuit by throwing down the knife switch, and any battery may be cut out by throwing the switch up. With this wiring layout, any number of batteries from one to ten may be cut-in by means of the switches. Thus, to charge five batteries, switches 1 to 5 are thrown down, and switches 5 to 10 are thrown up, thereby short-circuiting them. [Fig. 43 Wiring for a charging circuit, using a DPDT switch for each battery; and Fig. 44 Wiring for a charging circuit, using jumpers to connect batteries in series] Figure 44 shows a ten-battery charging circuit on which the batteries are connected in series by means of jumpers fitted with lead coated test clips, as shown. This layout is not as convenient as that shown in Figure 43, but is less expensive. Using Motor-Generator Sets [Fig. 45 Ten battery motor-generator charging set] Where no direct current supply is available, a motor-generator or a rectifier must be installed. The motor-generator is more expensive than a rectifier, but is preferred by some service stations because it is extremely flexible as to voltage and current, is easily operated, is free from complications, and has no delicate parts to cause trouble. Motor-Generator sets are made by a number of manufacturers. Accompanying these sets are complete instructions for installation and operation, and we will not attempt to duplicate such instructions in this book. Rules to assist in selecting the equipment will, however, be given. Except in very large service stations, a 40 volt generator is preferable. It requires approximately 2.5 volts per cell to overcome the voltage of a battery in order to charge it, and hence the 40 volt generator has a voltage sufficient to charge 15 cells in series on one charging line. Five 6 volt batteries may therefore be charged at one time on each line. With a charging rate of 10 amperes, each charging line will require 10 times 40, or 400 watts. The size of the generator will depend on the number of charging lines desired. With 10 amperes charging current per line, the capacity of the generator required will be equal to 400 watts multiplied by the number of charging lines. One charging line will need a 400 watt outfit. For two charging lines 800 watts are required. Each charging line is generally provided with a separate rheostat so that its charging rate may be adjusted to any desired value. This is an important feature, as it is wrong to charge all batteries at the same rate, and with separate rheostats the current on each line may be adjusted to the correct value for the batteries connected to that line. Any number of batteries up to the maximum may be charged on each line. [Fig. 46 Thirty-two battery motor-generator charging set] In choosing a charging outfit, it is important not to get one which is too large, as the outfit will operate at a loss when running under a minimum load. It is equally important not to get one which is too small, as it will not be able to take care of the batteries fast enough, and there will be a "waiting list" of batteries which cannot be charged until others are taken off charge. This will prevent the giving of good service. Buy an outfit that will care for your needs in the future, and also operate economically at the present time. Most men going into the battery business make the mistake of underestimating their needs, and getting equipment which must soon be discarded because of lack of capacity. The manufacturers each make a number of sizes, and the one which will best fill the requirements should be chosen. In selecting an outfit the manufacturer's distributor or dealer should be consulted in deciding what size outfit to obtain. The particular outfit will depend on the voltage and frequency of the alternating current power circuits, the maximum charging current desired (10 amperes per line is ample), and the greatest number of batteries to be charged at one time. For the beginner, a 500 watt ten battery outfit, as shown in Fig. 45, is suitable. For the medium sized garage that specializes in battery charging, or for the small battery service station, a one kilowatt outfit is most satisfactory. Two charging panels are generally furnished with this outfit, and two charging lines may thus be used. This is an important feature, as one line may be used in starting a charge at 10 amperes, and the other for charging the batteries, that have begun to gas, at a reduced rate. Fig. 46 shows a 2 K. W. four-circuit, 32 battery motor-generator set. Each circuit is provided with a separate rheostat and ammeter. The two terminals near the top of each rheostat are connected to one charging circuit. The two terminals near the lower end of each rheostat are connected to the generator. The 2 kilowatt set is suitable for a city garage, or a battery service station in a medium sized town. A beginner should not purchase this large set, unless the set can be operated at at least one-fourth capacity continuously. As a service station grows, a 5 kilowatt set may be needed. The 1, 2 and 5 kilowatt sets should not be used on anything but city power lines. Single phase, or lighting lines are not satisfactory for handling these sets. A few suggestions on Motor-Generator Sets 1. Installation. Set the motor-generator on as firm a foundation as possible. A good plan is to bolt it to a heavy bench, in which position it is easily inspected and adjusted, and is also less likely to be hit by acid spray, water, etc. Set the motor-generator at some distance from the batteries so that acid spray and fumes will not reach it. Sulphuric acid will attack any metal and if you are not careful, your motor-generator may be damaged seriously. The best plan is to have the motor generator set outside of the charging room, so as to have a wall or partition between the motor-generator and the batteries. The charging panels may be placed as near the batteries as necessary for convenience, but should not be mounted above the batteries. Figure 47 shows a convenient layout of motor-generator, charging panels, and charging benches. Note that the junipers used in connecting the batteries together are run through the upper holes of the wire porcelain insulating cleats, the lower hole of each insulator supporting the wire from the charging panel which runs to the end of the bench. [Fig. 47] Fig. 47. Convenient Arrangement of Motor-Generator, Charging Panels, and Charging Benches Instructions for the wiring connections to the power lines generally come with each outfit, and they should be followed carefully. Fuses in both the motor and generator circuits are especially important, as they protect the machines from damage due to overloads, grounds, or short-circuits. The generator must be driven in the proper direction or the generator will not build up. The rotation of a three-phase motor may be reversed by reversing, and Charging Benches any two of the cables. To reverse a two-phase motor, reverse the cables of either phase. Before putting a motor-generator set into operation, be sure to check all connections to make sure that everything checks with the instructions furnished by the manufacturer. Operating the Charging Circuits A generator operates most efficiently when delivering its rated output. Therefore, keep the generator as fully loaded as possible at all times. When you do not have enough batteries to run the generator at full load, run each charging circuit at full load, and use as few circuits as possible. This will reduce your power bill, since there is a loss of power in the rheostat of each charging circuit, this loss being the greatest when only one battery is on the circuit, and a minimum when the circuit is fully loaded. With several charging circuits, it is also possible to put batteries which are in the same condition on one circuit and adjust the charging rate to the most suitable value. Thus, badly sulphated batteries, which must be charged at a low rate, may be put on the same circuit, while batteries which have had only a normal discharge may be put oil another circuit and charged at a higher rate. As each battery becomes almost fully charged, it may be removed from the circuit and put on another circuit and the charge completed at the finishing rate. This is a good practice, since some batteries will begin to gas sooner than others, and if the charging rate is not reduced, the batteries which have begun to gas will have active material blown out by the continued gassing. A careful study of such points will lead to a considerable saving in power costs. Care of Motor-Generator Set A. Machine will not build up or generate. This may be due to: 1. Machine rotating in wrong direction. 2. Brushes not making good contact. Clean commutator with fine sandpaper. 3. Wrong connections of field rheostat-check connections with diagram. 4. Open circuit in field rheostat. See if machine will build up with field rheostat cut out. B. Excessive heating of the commutator. This may be due to: 1. Overload--Check your load and compare it with nameplate reading. Add the total amperes on all the panels and see that it does not exceed the ampere reading on the nameplate. 2. Wrong setting of the brush rocker arm. This causes sparking, which soon will cause excessive heating. 3. Rough commutator. This will cause the brushes to chatter, be noisy and spark. Caused many times by allowing copper to accumulate on the bottom of the brushes. 4. Insufficient pressure on brushes, resulting in sparking. This may be due to brushes wearing down to the point where the brush lead screw rests on the brush holder. 5. Dirt and grease accumulating between the brush and brush holder causing brush to stick; brush must always move freely in the holder. 6. Brush holder may have come loose, causing it to slip back, relieving brush press-Lire. 7. Brush spring may have become loosened, releasing the tension. 8. Watch commutator carefully and keep it in the best of condition. There will not be excessive heating without sparking. Excessive sparking may raise the temperature so high as to cause throwing of solder. You can avoid all this by taking proper care of the commutator. C. Ammeters on Panels Read Reverse: This is caused by improperly connecting up batteries, which has reversed the polarity of the generator. This generally does no harm, since in most cases the batteries will automatically reverse the polarity of the generator. Generally the condition may be remedied by stopping the machine, reversing the batteries and starting the machine again. If this is unsuccessful raise the brushes on the machine. Connect five or six batteries in series in the correct way to one panel, while the machine is not in operation. Turn on the panel switch. When the machine is started, it will then build up in the right direction. If it does not do so, repeat the above, using a larger number of batteries. D. Machine Refuses to Start. If there is a humming noise when you try to start the motor, and the outfit does not start, one of the fuses needs replacing. The outfit will hum only on two or three phase current. Never leave the power turned on with any of the fuses out. Constant-Potential Charging In the Constant-Potential system of battery charging, the charging voltage is adjusted to about 7.5, and is held constant throughout the charge. With this system a discharged battery receives a heavy current when it is put on charge. This current gradually decreases as the battery charges, due to the increasing battery voltage, which opposes, or "bucks" the charging voltage, and reduces the voltage which is effective in sending current through the batteries. Such a charge is called "tapering" charge because the charging current gradually decreases, or "tapers" off. The principle of a "tapering" charge is, of course, that a discharged battery may safely be charged at a higher rate than one which is only partly discharged, because there is more lead sulphate in the discharged battery which the action of the current changes back to active material. As the battery charges, the amount of lead sulphate decreases and since there is less sulphate for the current to act upon, the charging rate should be reduced gradually. If this is not done, excessive gassing will occur, resulting in active material being blown from the grids. A battery which has been badly sulphated, is of course, in a discharged condition, but is not, of course, able to absorb a heavy charging rate, and in handling such batteries on a constant potential system, care must be taken that the charging rate is low. Another precaution to be observed in all constant potential charging is to watch the temperature of batteries while they are drawing a heavy charging current. A battery which gasses soon after it is put oil charge, and while still in a discharged condition, should be taken off the line, or the charging line voltage reduced. With constant potential charging, as with constant current charging, the two things to watch are temperature and gassing. Any charging rate which does not cause an excessive temperature or early gassing is safe, and conversely any charging rate which causes an excessive battery temperature, or causes gassing while the battery is still less than three-fourths charged, is too high. [Fig. 48] Fig. 48. Hobart Bros. Co. 3 K. W. Constant Potential Motor-Generator Charging Set The Constant-Potential Charging Set manufactured by the Hobart Bros. Co., consists of a 3 K.W. generator rated at 7.5 volts, and 400 amperes. This generator is direct connected to a 5 H.P. motor, both machines being mounted oil the same base plate. Figure 48 shows this outfit. Note that for the charging line there are three bus-bars to which the batteries are connected. Twelve volt batteries are connected across the two outside bus-bars, while six volt batteries are connected between the center bus-bar and one of the outer ones. The Tungar Rectifier [Fig. 49 Tungar rectifier bulb] All rectifiers using oil are operated on the principle that current can pass through them in one direction only, due to the great resistance offered to the flow of current in the opposite direction. It is, of course, not necessary to use mercury vapor for the arc. Some rectifiers operate on another principle. Examples of such rectifiers are the Tungar made by the General Electric Co., and the Reetigon, made by the Westinghouse Electric and Manufacturing Co. The Tungar Rectifier is used extensively and will therefore be described in detail. The essential parts of a Tungar Rectifier are: A bulb, transformer, reactance, and the enclosing case and equipment. The bulb is the most important of these parts, since it does the rectifying. It is a sort of check valve that permits current to flow through the charging circuit in one direction only. In appearance the bulb, see Figure 49, resembles somewhat an ordinary incandescent bulb. In the bulb is a short tungsten filament wound in the form of a tight spiral, and supported between two lead-in wires. Close to the filament is a graphite disk which serves as one of the electrodes. Figure 50 shows the operating principle of the Tungar. "B" is the bulb, containing the filament "F" and the graphite electrode "A." To serve as a rectifier the bulb filament "F" must be heated, this being done by the transformer "T." The battery is connected as shown, the positive terminal directly to one side of the alternating current supply, and the negative terminal to the graphite electrode "A." To understand the action which takes place, assume an instant when line wire C is positive. The current then flows through the battery, through the rheostat and to the graphite electrode. The current then flows through the are to the filament and to the negative side of the line, as indicated by the arrows. During the next half cycle when line wire D is positive, and C is negative, current tends to flow through the bulb from the filament to the graphite, but as the resistance offered to the flow of current in this direction is very high, no current will flow through the bulb and consequently none through the battery. [Fig. 50 Illustration of Tungar "half-wave" rectifier] [Fig. 51 Illustration of Tungar "full-wave" rectifier] The rectifier shown in Figure 50 is a "half-wave" rectifier. That is, only one-half of each alternating current wave passes through it to the battery. If two bulbs are used, as shown ill Figure 51, each half of the alternating current wave is used in charging the battery. To trace the current through this rectifier assume an instant when line wire C is positive. Current will then flow to the graphite electrode of tube A, through the secondary winding of the transformer S to the center tap, through the rheostat, to the positive battery terminal, through the battery to the center of the primary transformer winding P, and through part of the primary winding to D. When D is positive, current will flow through tube B from the graphite electrode to the filament, to the center of transformer winding S, through the rheostat and battery to the center of transformer winding P, and through part of this winding to line wire C. In the actual rectifiers the rheostat shown in Figures 50 and 51 are not used, regulation being obtained entirely by means of other windings. From the foregoing description it will be seen that if the alternating current supply should fail, the batteries cannot discharge into the line, because in order to do so, they would have to heat up the filament and send current through the bulb from the filament to the graphite electrode. This the batteries cannot do, because the connections are such that the battery cannot send a current through the complete filament circuit and because, even if the batteries could heat the filament they could not send a current from the filament to the graphite, since current cannot flow in this direction. As soon as the alternating line is made alive again, the batteries will automatically start charging again. For these reasons night charging with the Tungar is entirely feasible, and no attendant is required to watch the batteries during the night. The Tungar Rectifier is made in the following sizes: A. Two Ampere Rectifier Catalogue No. 195529 [Fig. 52. The Two Ampere Tungar Rectifier] [Fig. 53 Internal wiring of the two ampere tungar rectifier] This is the smallest Tungar made. Figure 52 shows the complete rectifier. Figure 53 shows the internal wiring. This Tungar will charge a 6 volt battery at two amperes, a 12 volt battery at one ampere and eight cells at 0.75 ampere. It is suitable for charging a lighting battery, or for a quick charge of a motorcycle or ignition battery. It will also give a fairly good charge over night to a starting battery. Another use for this rectifier is to connect it to a run-down starting battery to prevent it from freezing over night. Of course, a battery should not be allowed to run down during cold weather, but if by chance a battery does run down, this Tungar will prevent it from freezing during the night. The two ampere Tungar is, of course, more suitable for the car owner than for a garage or service station. It is also very suitable for charging one Radio "A" battery. The two ampere Tungar is normally made for operation on a sixty cycle circuit, at 115 volts. It may also be obtained for operation on 25-30, 40-50, and 125-133 cycles alternating supply line. See table on Page 130. B. The One Battery Rectifier Catalogue No. 219865 [Fig. 54. The One Battery Tungar Rectifier] This Tungar will charge a 6 volt battery at five amperes, or a 12 volt battery at three amperes. Figure 54 shows this Tungar, with part of the casing cut away to show the internal parts. To take care of variations in the voltage of the alternating current supply from 100 to 130, a set of connections is provided which are numbered 105, 115, and 125. For most supply voltages, the 115 volt tap is used, for lower voltage the 105 volt tap is used, and for higher voltage the 125 volt tap is used. This Tungar is designed for 60 cycle circuits, but on special order it may be obtained for operation on other frequencies. This Tungar is most suitable for a car owner, is satisfactory for charging a radio "A" battery, and a six volt starting and lighting battery at one time. C. The Two Battery Rectifier Catalogue No. 195530 [Fig. 55. The Two Battery Tungar Rectifier] This Tungar is shown in Figure 55, with part of the casing cut away to show the internal parts. It was formerly sold to the car owner, but the one battery Tungar is now recommended for the use of the car owner. The two-battery Tungar is therefore recommended for the very small service station, or for department stores for taking care of one or two batteries. The four battery Tungar, which is the next one described, is recommended in preference to the two-battery outfit where there is the slightest possibility of having more than two batteries to charge at one time. The two-battery rectifier will charge two 6-volt batteries, or one 12-volt battery at six amperes, or one 18-volt battery at three amperes. It has a double-pole fuse block mounted on the auto transformer core, which has one fuse plug only. Figure 55 shows the fuse plug in the position for charging a 6-volt battery. When it is desired to charge a 12-volt battery or an 18-volt battery, the fuse is removed from the first receptacle and is screwed into the second receptacle. [Fig. 56. The Four Battery Tungar Rectifier Complete] The two-battery rectifier is designed to operate on a 115-volt, 60-cycle line, but oil special order may be obtained for operation on 25-30, 40-50, and 125-133 cycle lines. D. The Four Battery Tungar Catalogue No. 193191 This Tungar is shown complete in Figure 56. In Figure 57 the top has been raised to show the internal parts. Figure 58 gives the internal wiring connections for a four battery Tungar designed for operation on a 115 volt line. The four battery Tungar will charge from one to four 6 volt batteries at 5 amperes or less. It is designed especially for garages having very few batteries to charge. These garages generally charge their boarders batteries rather than send them to a service station, and seldom have more than four batteries to charge at one time. The four battery Tungar is also suitable for the use of car dealers who wish to keep the batteries on their cars in good shape, and is convenient for preparing for service batteries as they come from the car manufacturer. [Fig. 57. The Four Battery Tungar Rectifier, with Top Raised to Show Internal Parts.] The four battery Tungar is designed for operation on a 60-cycle line at 115 or 230 volts. On special order this Tungar may be obtained for operation on other frequencies. E. The Ten Battery Rectifier Catalogue No. 179492 This is the Tungar which is most popular in the service stations, since it meets the charging requirements of the average shop better than the smaller Tungars. It will charge from one to ten 6 volt batteries, or the equivalent at six amperes or less. Where more than ten batteries are generally to be charged at one time, two or more of the ten battery Tungars should be used. Large service stations use as many as ten of these Tungars. [Fig. 58 Internal wiring of the four battery tungar rectifier] The efficiency of the ten battery Tungar at full load is approximately 75 per cent, which compares favorably with that of a mercury-are rectifier, or motor-generator of the same size. This makes the ten battery Tungar a very desirable piece of apparatus for the service station. [Fig. 59 Complete 10-battery Tungar rectifier] Figure 59 shows the complete ten battery Tungar, Figure 60 gives a side view without the door to show the internal parts. [Fig. 60 Side view, cross-section of 10-battery Tungar rectifier] Figure 61 shows the internal connections for use on a 115-volt A.C. line and Figure 62 the internal connections for use on a 230-volt line. This Tungar is made for a 60-cycle circuit, 25-30, 40-50, and 125-133 cycle circuits. [Fig. 61 Internal wiring for the 10 battery Tungar rectifier for operation on a 115 volts A.C. line] [Fig. 62 Internal wiring for the 10 battery Tungar rectifier for operation on a 230 volts A.C. line] F. The Twenty Battery Tungar Catalogue No. 221514 This Tungar will charge ten 6-volt batteries at 12 amperes, or twenty 6-volt batteries at six amperes. Figure 63 shows the complete rectifier, and Figure 64 shows the rectifier with the side door open to show the internal parts. This rectifier will do the work of two of the ten battery Tungars. It is designed for operation on 60 cycles, 230-volts. On special order it may be obtained for operation on 115 volts and also for other frequencies. The twenty battery Tungar uses two bulbs, each of which is the same as that used in the ten battery Tungar, and has two charging circuits, having an ammeter and regulating switch for each circuit. One snap switch connects both circuits to the supply circuit. The two charging circuits are regulated independently. For example, one circuit may be regulated to three amperes while the other circuit is delivering six amperes. It is also possible, by a system of connections to charge the equivalent of three circuits. For instance, five batteries could be charged at six amperes, five batteries at four amperes, and five batteries at ten amperes. Other corresponding combinations are possible also. General Instructions and Information on Tungars Life of Tungar Bulbs. The life of the Tungar Bulb is rated at 600 to 800 hours, but actually a bulb will give service for 1,200 to 3,000 hours if the user is careful not to overload the bulb by operating it at more than the rated current. [Fig. 63 The 20 battery Tungar rectifier] [Fig. 64 Internal view of the 20 battery Tungar rectifier] Instructions. Complete instructions are furnished with each Tungar outfit, the following being those for the ten battery Tungar. Installation A Tungar should be installed in a clean, dry place in order to keep the apparatus free from dirt and moisture. To avoid acid fumes, do not place the Tungar directly over the batteries. These precautions will prevent corrosion of the metal parts and liability of poor contacts. Fasten the Tungar to a wall by four screws, if the wall is of wood, or by four expansion bolts if it is made of brick or concrete. Though the electrical connections of the outfit are very simple, it is advisable (when installing the apparatus) to employ an experienced wireman familiar with local requirements regarding wiring. Line Connections The two wires extending from the top of the Tungar should be connected to the alternating current supply of the same voltage and frequency, as stamped on the name plate attached to the front panel. These connections should be not less than No. 12 B. & S. gauge wire and should be firmly soldered to the copper lugs. External fuses are recommended for the alternating-current circuit, as follows: With 115-volt line use 15-ampere capacity fuses. With 230-volt line use 10 ampere capacity fuses. One of the bulbs (Cat. No. 189049) should now be firmly screwed into its socket. Squeeze the spring clip attached to the beaded cable and slip this clip over the wire protruding from the top of the bulb. Do not bend the wire. Battery Connections In making battery connections have the snap-switch in the "Off" position. The two wires extending from the bottom of the Tungar should be connected to the batteries. The wire on the left, facing the front panel, is marked + (positive) and the other wire - (negative). The positive wire should be connected to the positive terminal of the battery and the negative wire to the negative terminal. The two flexible battery cables are sometimes connected directly to the two wires projecting from the bottom of the Tungar. These cables should be securely cleated to the wall about six inches below the outfit. This arrangement will relieve the strain on the Tungar wires when cables are changed to different batteries. When two or more batteries are to be charged, they should be connected in series. The positive wire of the Tungar should be connected to the positive terminal of battery No. 1, the negative terminal of this battery of the positive terminal of battery No. 2, the negative terminal of battery No. 2 to the positive terminal of battery No. 3, and so on, according to the number of batteries in circuit. Finally the negative terminal of the last battery should be connected to the negative wire from the Tungar. Reverse connections on one battery is likely to damage the plates; and reverse connections oil all the batteries will blow one or more fuses. Operation A Tungar is operated by means of a snap-switch in the upper left-hand corner and a regulating switch in the center. Before starting the apparatus, the regulating switch should be in the "low" position. The Tungar is now ready to operate. Turn the snap-switch to the right to the "On" position, and the bulb will light. Then turn the regulating switch slowly to the right, and, as soon as the batteries commence to charge, the needle on the ammeter will indicate the charging current. This current may be adjusted to whatever value is desired within the limits of the Tungar. The normal charging rate is six amperes, but a current of as high as seven amperes may be obtained without greatly reducing the life of the bulb. Higher charging rates reduce its life to a considerable extent. Lower rates than normal (six amperes) will increase the life of the bulb. Turn the snap-switch to the "Off" position when the charging of one battery or of all the batteries is completed; or when it is desired to add more batteries to the line. The Tungar should be operated only by the snap-switch and not by any other external switch in either line or battery circuits. When the snap-switch is turned, the batteries will be disconnected from the supply line, and then they may be handled without danger of shock. Immediately after turning the snap-switch, move the regulating handle back to the "Low" position. This prevents any damage to the bulb from the dial switch being in an improper position for the number of batteries next charged. Troubles If on turning on the alternating-current switch the bulb does not glow: 1. See whether the alternating-current supply is on. 2. Examine the supply line fuses. If these are blown, or are defective, replace them with 15 ampere fuses for a 115-volt line or with 10-ampere fuses for a 220-volt line. 3. Make sure that the bulb is screwed well into the socket. 4. Examine the contacts inside the socket. If they are tarnished or dirty, clean them with sandpaper. 5. Try a new bulb, Cat. No. 189049. The old bulb may be defective. If the bulb lights but no current shows on the ammeter: 1. Examine the connections to the batteries, and also the connections between them. Most troubles are caused by imperfect battery connections. 2. Examine the fuses inside the case. If these are blown or are defective, replace them with 15 ampere fuses, Cat. No. 6335. 3. See that the clip is on the wire of the bulb. 4. The bulb may have a slow leak and not rectify. Try a new bulb, Cat. No. 189049. 5. Have the switch arm make good contact on the regulating switch. If the current on the ammeter is high and cannot be reduced: 1. The ammeter pointer may be sticking; tap it lightly with the hand. The ammeter will not indicate the current correctly if the pointer is not on the zero line when the Tungar is not operating. The pointer may be easily reset by turning slightly the screw on the lower part of the instrument. 2. Be sure that the batteries are not connected with reversed polarity. 3. The alternating-current supply may be abnormally high. If only one three-cell battery is being charged, and the alternating-current supply is slightly high, then the current on the ammeter may be high. The simplest remedy is to connect in another battery or a small amount of resistance. A spare bulb should always be kept on hand and should be tested for at least one complete charge before being placed in reserve. All Tungar bulbs are made as nearly perfect as possible, but occasionally one is damaged in shipment. It may look perfect and yet not operate. For this reason all bulbs should be tried out on receipt. If any bulb is found defective, the tag which accompanies it should be filled out, and bulb and tag should be returned to your dealer or to the nearest office of the General Electric Company, transportation prepaid. Tungar Rectifiers (The following columns omitted from the table below: Catalog Numbers, Dimensions, Net Weight, and Shipping Weight.) Name No. 6V Bats No. 12V Bats. DC Amps DC Volts AC Volts Freq. ------------- ------------- ------- -------- -------- ----- 2 Amp. Tungar 1 (2 amps.) 1 (1 amps.) 1-2 7.5-15 115 60 2 Amp. Tungar 1 (2 amps.) 1 (1 amps.) 1-2 7.5-15 115 60 2 Amp. Tungar 1 (2 amps.) 1 (1 amps.) 1-2 7.5-15 115 40-50 2 Amp. Tungar 1 (2 amps.) 1 (1 amps.) 1-2 7.5-15 115 25-30 2 Amp. Tungar 1 (2 amps.) 1 (1 amps.) 1-2 7.5-15 115 125-133 1 Battery Tungar 1 (5 amps.) 1 (3 amps.) 1-5 7.5-15 115 60 2 Battery Tungar 2 (6 amps.) 1 (6 amps.) 1-6 7.5-15 115 60 2 Battery Tungar 2 (6 amps.) 1 (6 amps.) 1-6 7.5-15 115 40-50 2 Battery Tungar 2 (6 amps.) 1 (6 amps.) 1-6 7.5-15 115 25-30 2 Battery Tungar 2 (6 amps.) 1 (6 amps.) 1-6 7.5-15 115 125-130 4 Battery Tungar 4 (5 amps.) 2 (5 amps.) 1-5 7.5-30 115 60 4 Battery Tungar 4 (5 amps.) 2 (5 amps.) 1-5 7.5-30 115 40-50 4 Battery Tungar 4 (5 amps.) 2 (5 amps.) 1-5 7.5-30 115 25-30 4 Battery Tungar 4 (5 amps.) 2 (5 amps.) 1-5 7.5-30 115 125-133 4 Battery Tungar 4 (5 amps.) 2 (5 amps.) 1-5 7.5-30 230 60 4 Battery Tungar 4 (5 amps.) 2 (5 amps.) 1-5 7.5-30 230 40-50 10 Battery Tungar 10 5 1-6 7.5-75 115 60 10 Battery Tungar 10 5 1-6 7.5-75 115 40-50 10 Battery Tungar 10 5 1-6 7.5-75 115 25-30 10 Battery Tungar 10 5 1-6 7.5-75 115 125-133 10 Battery Tungar 10 5 1-6 7.5-75 230 60 10 Battery Tungar 10 5 1-6 7.5-75 230 40-50 20 Battery Tungar 10 (12A.)/ 20 (6A.) 10 (6A.) 1-12 7.5-75 230 60 20 Battery Tungar 10 (12A.)/ 20 (6A.) 10 (6A.) 1-12 7.5-75 230 40-50 20 Battery Tungar 10 (12A.)/ 20 (6A.) 10 (6A.) 1-12 7.5-75 230 25-30 Bulb (all 4 Amp. Tung.) --- --- --- --- --- --- Bulb (all 10 and 12 Amp. Tung.) --- --- --- --- --- --- Bulb (all 2 Amp. Tung.) --- --- --- --- --- --- Bulb (all 1-2 Bat. Tung.) --- --- --- --- --- --- Mercury Arc Rectifier The operation of the mercury are rectifier depends upon the fact that a tube containing mercury vapor under a low pressure and provided with two electrodes, one of mercury and the other of some other conductor, offers a very high resistance to a current tending to pass through the tube from the mercury electrode to the other electrode, but offers a very low resistance to a current tending to pass through the tube in the opposite direction. Current passes from the metallic electrode to the mercury electrode through an are of mercury vapor which is established in the tube by tilting it so the mercury bridges the gap between the mercury and an auxiliary electrode just for an instant. The absence of moving parts to got out of order is an advantage possessed by this rectifier over the motor-generator. The charging current from the rectifier cannot, however, be reduced to as low a value as with the motor-generator, and this is a disadvantage. This rectifier is therefore more suitable for larger shops, especially where electric truck and pleasure cars are charged. Mechanical Rectifiers Mechanical rectifiers have a vibrating armature which opens and closes the charging circuit. The circuit is closed during one half of each alternating current cycle, and open during the next half cycle. The circuit is thus closed as long as the alternating current is flowing in the proper direction to charge the battery, and is open as long as the alternating current is flowing in the reverse direction. These rectifiers therefore charge the battery during half the time the battery is on charge, this also being the case in some of the are rectifiers. The desired action is secured by a combination of a permanent magnet and an electromagnet which is connected to the alternating current supply. During half of the alternating current cycle, the alternating current flowing through the winding of the electromagnet magnetizes the electromagnet so that it strengthens the magnetism of the permanent magnet, thus causing the vibrator arm to be drawn against the magnet. The vibrator arm carries a contact which touches a stationary contact point when the arm is drawn against the magnet, thus closing the charging circuit. During the next half of the alternating current cycle, or wave, the current through the electromagnet coil is reversed, and the magnetism of the electromagnet then weakens the magnetism of the permanent magnet, and the vibrator arm is drawn away from the magnet and the charging circuit is thus opened. During the next half of the alternating current cycle the vibrator arm is again drawn against the magnet, and so on, the contact points being closed and opened during half of each alternating current cycle. Mechanical rectifiers are operated from the secondary windings of transformers which reduce the voltage of the alternating current line to the voltage desired for charging. Each rectifier unit may have its own complete transformer, or one large transformer may operate a number of rectifier units by having its secondary, or low tension winding divided into a number of sections, each of which operates one rectifier. The advantages of the mechanical rectifier are its simplicity, cheapness and portability. This rectifier also has the advantage of opening the charging circuit when the alternating current supply fails, and starting again automatically when the line is made alive again. Any desired number of independent units, each having its own charging line, may be used. The charging current generally has a maximum value of 6 amperes. Each rectifier unit is generally designed to charge only one or two six volt batteries at one time. Stahl Rectifier This is a unique rectifier, in which the alternating current is rectified by being sent through a commutator which is rotated by a small alternating current motor, similar to the way the alternating current generated in the armature of a direct current generator is rectified in the commutator of the machine. The Stahl rectifier supplies the alternating current from a transformer instead of generating it as is done in a direct current generator. Brushes which bear on the commutator lead to the charging circuit. The Stahl rectifier is suitable for the larger service stations. It gives an interrupted direct current. It is simple in construction and operation, and is free of delicate parts. Other Charging Equipment If there is no electric lighting in the shop, it will be necessary to install a generator and a gas, gasoline, or steam engine, or a waterwheel to drive it. A 10 battery belt driven generator may be used in such a shop, and may also, of course, be used with a separate motor. The generator should, of course, be a direct current machine. The size of the generator will depend upon the average number of batteries to be charged, and the amount of money available. Any of the large electrical manufacturers or supply houses will give any information necessary for the selection of the type and size of the outfit required. If an old automobile engine, and radiator, gas tank, etc., are on hand, they can be suitably mounted so as to drive the generator. CHARGING BENCH [Fig. 65. Charging Bench with D.P.D.T. Switch for Each Battery] Figures 47 and 65 show charging benches in operation. Note that they are made of heavy stock, which is of course necessary on account of the weight of the batteries. The top of the charging bench should be low, to eliminate as much lifting of batteries as possible. Figure 66 is a working drawing of the bench illustrated in Figure 65. Note the elevated shelf extending down the center. This is convenient for holding water bottle, acid pitcher, hydrometer. Note also the strip "D" on this shelf, with the voltmeter hung from an iron bracket. With this arrangement the meter may be moved to any battery for voltage, cadmium, and high rate discharge readings. It also has the advantage of keeping the volt meter in a convenient and safe place, where it is not liable to have acid spilled on it, or to be damaged by rough handling. In building the bench shown in Figure 66, give each part a coat of asphaltum paint before assembling. After assembling the bench give it two more coats of asphaltum paint. [Fig. 66 Working drawing of charging bench shown in Fig. 65] Figures 67, 68, 69 and 70 show the working plans for other charging benches or tables. The repairman should choose the one which he considers most suitable for his shop. In wiring these benches, the elevated shelf shown in Figure 66 may be added and the double pole, double throw switches used. Instead of these switches, the jumpers shown on the benches illustrated in Figure 47 may be used. If this is done, the elevated shelf should also be installed, as it is a great convenience for the hydrometer, voltmeter, and so on, as already described. As for the hydrometer, thermometer, etc., which were listed on page 96 as essential accessories of a charging bench, the Exide vehicle type hydrometer is a most excellent one for general use. This hydrometer has a round bulb and a straight barrel which has projections on the float to keep the hydrometer in an upright position when taking gravity readings. The special thermometer is shown in Figure 37. A good voltmeter is shown in Figure 121. This voltmeter has a 2.5 and a 25 volt scale, which makes it convenient for battery work. It also gives readings of a .2 and 2.0 to the left of the zero, and special scale markings to facilitate the making of Cadmium tests as described on page 174. As for the ammeter, if a motor-generator set, Tungar Rectifier or a charging-rheostat is used, the ammeter is always furnished with the set. If a lamp bank is used, a switchboard type meter reading to about 25 amperes is suitable. With the constant potential system of charging, the ammeters are furnished with the motor-generator set. They read up to 300 amperes. The bottles for the distilled water and electrolyte are not of special design and may be obtained in local stores, There are several special water bottles sold by jobbers, and they are convenient, but not necessary. Figure 133 shows a very handy arrangement for a water or acid bottle. [Fig. 67 Working drawing of eight foot charging bench] [Fig. 68 Working drawing of a ten foot charging bench] [Fig. 69 Working drawing of a twelve foot charging bench] [Fig. 70 Working drawing of a twelve foot charging bench (without drain rack)] [Fig. 71 Working drawing of a two man work bench to be placed against a wall] [Fig. 72 Working drawing of a double, four man work bench, with two tool drawers for each man] WORK BENCH A work bench is more of a standard article than the charging bench, and there should be no trouble in building one. Figure 38 illustrates a good bench in actual use. A vise is, of course, necessary, and the bench should be of solid construction, and should be given several coats of asphaltum paint. [Fig. 73 Working drawing of a two man, double work bench] Figure 71 shows a single work bench which may be placed against a wall. Figures 72 and 73 show double work benches. Note that each bench has the elevated shelf, which should not, under any consideration be omitted, as it is absolutely necessary for good work. The tool drawers are also very convenient. It is best to have a separate "tear down" bench where batteries are opened, as such a bench will be a wet, sloppy place and would not be suitable for anything else. It should be placed near the sink or wash tank, as shown in the shop layouts illustrated in Figures 136 to 142. SINK OR WASH TANK [Fig. 74] Fig. 74. Sink with Faucet, and Extra Swinging Arm Pipe for Washing Out Jars. Four Inch Paint Brush for Washing Battery Cases An ordinary sink may be used, as shown in Figure 74. This figure also shows a convenient arrangement for washing out jars. This consists of a three-fourths inch pipe having a perforated cap screwed over its upper end. Near the-floor is a valve which is normally held closed by a spring, and which has attached to it a foot operated lever. In washing sediment out of jars, the case is inverted over the pipe, and the water turned on by means of the foot lever. A number of fine, sharp jets of water are thrown up into the jar, thereby washing out the sediment thoroughly. If an ordinary sink is used, a settling tank should be placed under it, as shown in Figure 75. Otherwise, the drain pipe may become stopped up with sediment washed out of the jars. Pipe B is removable, which is convenient in cleaning out the tank. When the tank is to be cleaned, lift pipe B up very carefully and let the water drain out slowly. Then scoop out the sediment, rinse the tank with water, and replace pipe B. In some places junk men will buy the sediment, or "mud," as it is called. [Fig. 75 Settling tank to be used with sink shown in Fig. 74] Figures 76 and 77 give the working drawings for more elaborate wash tanks. The water supply shown in Figure 74 may be used here, and the drain pipe arrangement shown in Figure 75 may be used if desired. [Fig. 76 Working drawing of a wash tank] [Fig. 77 Working drawing of a wash tank] LEAD BURNING (WELDING) OUTFIT In joining the connectors and terminals to the positive and negative posts, and in joining plate straps to form a "group," the parts are joined or welded together, melting the surfaces to be joined, and then melting in lead from sticks called "burning lead." The process of joining these parts in this manner is known as "lead burning." Directions for "lead burning" are given on page 210. There are various devices by means of which the lead is melted during the "lead burning" process. The most satisfactory of these use a hot, pointed flame. Where such a flame is not obtainable, a hot carbon rod is used. The methods are given in the following list in the order of their efficiency: 1. Oxygen and Acetylene Under Pressure in Separate Tanks. The gases are sent through a mixing valve to the burning tip. These gases give the hottest flame. 2. Oxygen and Hydrogen Under Pressure in Separate Tanks, Fig. 78. The flame is a very hot one and is very nearly as satisfactory as the oxygen and acetylene. [Fig. 78] Fig. 78. Hydrogen-Oxygen Lead Burning Outfit. A and B are Regulating Valves. C is the Safety Flash Back Tank. D is the Mixing Valve. E is the Burning Tip. 3. Oxygen and Illuminating Gas. This is a very satisfactory method, and one that has become very popular. In this method it is absolutely necessary to have a flash back tank (Fig. 79) in the gas line to prevent the oxygen from backing up into the gas line and making a highly explosive mixture which will cause a violent explosion that may wreck the entire shop. [Fig. 79 Flash-back tank for lead burning outfit] To make such a trap, any strong walled vessel may be used, as shown in Figure 79. A six to eight inch length of four inch pipe with caps screwed over the ends will make a good trap. One of the caps should have a 1/2 inch hole drilled and tapped with a pipe thread at the center. This cap should also have two holes drilled and tapped to take a 1/4 inch pipe, these holes being near the inner wall of the large pipe, and diametrically opposite one another. Into one of these holes screw a short length of 1/4 inch pipe so Fig. 79. Flash-Back Tank for Lead Burning Outfit that it comes flush with the inner face of the cap. This pipe should lead to the burning outfit. Into the other small hole screw a length of 1/4 inch pipe so that its lower end comes within 1/2 inch of the bottom of the trap. This pipe is to be connected to the illuminating gas supply. To use the trap, fill within one inch of top with water, and screw a 1/2 inch plug into the center hole. All connections should be airtight. 4. Acetylene and Compressed Air. The acetylene is bought in tanks, and the air compressed by a pump. 5. Hydrogen and Compressed Air. This is the method that was very popular several years ago, but is not used to any extent at present because of the development of the first three methods. A special torch and low pressure air supply give a very satisfactory flame. 6. Wood Alcohol Torch. A hand torch with a double jet burner gives a very clean, nonoxidizing flame. The flame is not as sharp as the oxygen flame, and the torch is not easily handled without the use of burning collars and moulds. The torch has the advantage of being small, light and portable. A joint may be burned without removing the battery from the car. 7. Gasoline Torch. A double jet gasoline torch may be used, provided collars or moulds are used to prevent the lead from running off. The torch gives a broad flame which heats the parts very slowly, and the work cannot be controlled as easily as in the preceding methods. [Fig. 80 Carbon lead burning outfit] 8. Carbon Arc. This is a very simple method, and requires only a spare 6 volt battery, a 1/4 inch carbon rod, carbon holder, cable, and clamp for attaching to battery. This outfit is shown in Fig. 80. It may be bought from the American Bureau of Engineering, Inc., Chicago, Ill. This outfit is intended to be used only when gas is not available, and not where considerable burning is to be done. In using this outfit, one terminal of an extra 6 volt battery is connected by a piece of cable with the connectors to be burned. The contact between cable and connector should be clean and tight. The cable which is attached to the carbon rod is then connected to the other terminal of the extra battery, if the battery is not fully charged, or to the connector on the next cell if the battery is fully charged. The number of cells used should be such that the carbon is heated to at least a bright cherry red color when it is touching the joint which is to be burned together. Sharpen the carbon to a pencil point, and adjust its position so that it projects from the holder about one inch. Occasionally plunge the holder and hot carbon in a pail of water to prevent carbon from overheating. After a short time, a scale will form on the surface of the carbon, and this should be scraped off with a knife or file. In burning in a connector, first melt the lead of the post and connector before adding the burning lead. Keep the carbon point moving over all parts to be joined, in order to insure a perfectly welded joint. 9. Illuminating Gas and Compressed Air. This is the slowest method of any. Pump equipment is required, and this method should not be used unless none of the other methods is available. The selection of the burning apparatus will depend upon individual conditions as well as prices, and the apparatus selected should be one as near the beginning of the foregoing list as possible. Directions for the manipulation of the apparatus are given by the manufacturers. The most convenient arrangement for the lead burning outfit is to run pipes from one end of the work bench to the other, just below the center shelf. Then set the gas tanks at one end of the bench and connect them to the pipes. At convenient intervals have outlets for attaching the hoses leading to the torch. EQUIPMENT FOR HANDLING SEALING COMPOUND (a) Stove. Where city gas is available, a two or three burner gas stove or hot-plate should be used. Where there is no gas supply, the most satisfactory is perhaps an oil stove. It is now possible to get an odorless oil stove which gives a hot smokeless flame which is very satisfactory. In the winter, if a coal stove is used to heat the shop, the stove may also be used for heating the sealing compound, but it will be more difficult to keep the temperature low enough to prevent burning the compound. (b) Pot or Kettle. An iron kettle is suitable for use in heating compound. Special kettles, some of which are non-metallic, are on the market, and may be obtained from the jobbers. (c) An iron ladle should be obtained for dipping up compound, and for pouring compound when sealing a battery. Figure 81 shows a convenient form of ladle which has a pouring hole in the bottom. A taper pin, which is raised by the extra handle allows a very fine stream of compound to be poured. The exact size of the ladle is not important, but one which is too heavy to be held in one hand should not be used. (d) Several old coffee pots are convenient, and save much time in sealing batteries. Sealing compound is a combination of heavy residues produced by the fractional distillation of petroleum. It is not all alike-that accepted for factory use and distribution to Service Stations must usually conform to rigid specifications laid down by the testing laboratories governing exact degrees of brittleness, elongation, strength and melting point. For these qualities it is dependent upon certain volatile oils which may be driven off from the compound if the temperature of the molten mass is raised above the comparatively low points where some of these oils begin to volatilize off as gaseous vapor or smoke. Compound from which certain of these valuable constituent oils have been driven off or "burned out" through overheating is recognized through too great BRITTLENESS and SHRINKAGE on cooling, causing "CRACKED COMPOUND" with all of its attending difficulties. [Fig. 81 Pouring ladle] Do not put too much cold compound in the kettle to begin with. It is not advisable to carry much more molten compound in the kettle at any time than can easily be dipped out-cold compound may be added during the day as needed. When there is considerable cold compound in the kettle, and the heating flame is applied, the lower bottom part of the mass next to the surface of the iron is brought to a melting point first-heat must be conveyed from this already hot part of the compound upward throughout the whole mass-so that before the top part of it is brought to a molten condition the lower inside layers are very hot indeed. If there is too much in the kettle these lower layers are necessarily raised in temperature beyond the point where they lose some of their volatile oils-they are "burned" before the whole mass of compound can be brought to a molten state. Do not use too large a heating flame under the kettle for the same reasons. A flame turned on "full blast" will certainly "burn" the bottom layers before the succeeding layers above are brought to the fusion point. USE A SLOW FLAME and TAKE TIME IN MELTING UP THE COMPOUND. It PAYS in the resulting jobs. The more compound is heated, the thinner it becomes--it should never be allowed to become so hot that it flows too freely--it should never exceed the viscosity of medium molasses. It should flow freely enough to run in all narrow spaces but NOT freely enough to flow THROUGH them before it cools. Stir the kettle frequently during the day. It is advisable about once a week to work as much compound out of the kettle as possible, empty that still remaining, clean the kettle out, and start with fresh compound. NEVER USE OLD COMPOUND OVER AGAIN--that is, do not throw compound that has been dug out of used batteries into the kettle with the new compound. The old compound is no doubt acid soaked, and this acid will work through the whole molten mass, making a satisfactory job a very doubtful matter indeed. Cold weather hardens sealing compound, of course, and renders it somewhat brittle and liable to crack. This tendency could be overcome by using a softer compound, but, on the other hand, compound so soft that it would have no tendency to crack in cold weather would be so soft in warm weather that it would fail to hold the assembly with the necessary firmness and security. It is far better policy to run the risk of developing a few cracks in the winter than a loose assembly in summer. Surface cracks developed in cold weather may be easily remedied by stripping off the compound around the crack with a heated tool, flashing with the torch and quickly re-sealing according to the above directions. It is not practical to work any oil agent, such as paraffin or castor oil, into the compound in an effort to soften it for use in cold weather. SHELVING AND RACKS The essential things about shelving in a battery shop are, that it must be covered with acid-proof paint, and must be made of heavy lumber if it is to carry complete batteries. Figure 82 shows the heavy shelving required in a stock-room, while Figure 83 shows the lighter shelving which may be used for parts, such as jars, cases, extra plates, and so on. [Fig. 82] Fig. 82. Typical Stockroom, Showing Heavy Shelving Necessary for Storing Batteries. Figures 84 and 85 show two receiving racks for batteries which come in for repairs. In many shops batteries are set on the floor while waiting for repairs. If there is plenty of floor space, this practice is not objectionable. In any case, however, it improves the looks of the shop, and makes a better impression on the customer to have racks to receive such batteries. Note that the shelves are arranged so as to permit acid to drain off. Batteries often come in with wet, leaky cases, and this shelf construction is suitable for such batteries. The racks shown in Figures 86 and 87 are for repaired batteries, new batteries, rental batteries, batteries in dry storage, and for any batteries which do not have wet leaky cases. Figures 88 and 89 show racks suitable for new batteries which have been shipped filled with electrolyte, batteries in "wet" or "live" storage, rental batteries, and so on. Note that these racks are provided with charging circuits so that the batteries may be given a low charge without removing them from the racks. Note also that the shelves are spaced two feet apart so as to be able to take hydrometer readings, voltage readings, add water, and so on, without removing the batteries from the racks. BINS Figure 90 gives the dimensions for equipment bins suitable for covers, terminals, inter-cell connectors, jars, cases, and various other parts. These bins can be made with any desired number of sections, and additional sections built as they are needed. [Fig. 83] Fig. 83. Corner of Workshop, Showing Lead Burning Outfit, Workbench and Vises. [Fig. 84 Working drawing of a 6-foot receiving rack] [Fig. 85 Working drawing of a 12-foot receiving rack] [Fig. 86 Working drawing of an 8-foot rack for repaired batteries, new batteries, rental batteries, batteries in dry storage, etc.] [Fig. 87 Working drawing of a 16-foot rack for repaired batteries, new batteries, rental batteries, batteries in dry storage, etc.] [Fig. 88 Working drawing of a 16-foot rack suitable for new batteries (shipped filled and fully charged), batteries in "wet" storage, rental batteries, etc.] [Fig. 88b End view of rack in Fig. 88] [Fig. 89 Working drawing of a 12-foot rack suitable for new batteries (shipped filled and fully charged), batteries in "wet" storage, rental batteries, etc.] [Fig. 89b End view of rack in Fig. 89] [Fig. 90 Working drawing of bins suitable for battery parts] BATTERY STEAMER Steaming is the most satisfactory method of softening sealing compound, making covers and jars limp and pliable. An open flame should never be used for this work, as the temperature of the flame is too high and there is danger of burning jars and covers and making them worthless. With steam, it is impossible to damage sealing compound or rubber parts. A soft flame from a lead burning torch is used to dry out the channels in the covers before sealing, and is run over the compound quickly to make the compound flow evenly and unite with the jars and covers. But in such work the flame is used for only a few seconds and is not applied long enough to do any damage. With a steaming outfit, it is also possible to distill water for use in mixing electrolyte and replacing evaporation in the cells. The only additional equipment needed is a condenser to condense the steam into water. [Fig. 91] Fig. 91. Battery Steamer, with Steam Hose for Each Cell [Fig. 92 Condenser for use with battery steamer] Figure 91 shows a steaming outfit mounted on a wall, and shows the rubber tube connections between the several parts. The boiler is set on the stove, water being supplied from the water supply tank which is hung above the boiler to obtain gravity feed. The water supply tank is open at the top, and is filled every morning with faucet water. This tank is suitable for any shop, even though a city water supply is available. A water pipe from the city lines may be run to a point immediately above the tank and a faucet or valve attached. Where there is no city water supply, the tank may, of course, be filled with a pail or pitcher. The boiler is equipped with a float operated valve which maintains a one to one and one-half inch depth of water. As the water boils away, the float lowers slightly and allows water to enter the boiler. In this way, the water is maintained at the proper level at all times. A manifold is fitted to the boiler and has six openings to which lengths of rubber tubing are attached. These tubes are inserted in the vent holes of the battery which is to be steamed. Any number of the steam outlets may be opened by drawing out the manifold plunger valve to the proper point. When distilling water, a tube is attached to one of the steam outlets as shown, and connected to the condenser as shown. A bottle is placed under the distilled water outlet to collect the distilled water. Cooling water enters the condenser through the tubing shown attached to the condenser at the lower right-hand edge. The other end of this tube is attached to the water faucet, or other cooling water supply. The cooling water outlet is shown at the lower left hand edge of the condenser. The cooling water inlet and outlet are shown in Figure 92. If there is no city water supply, a ten or twenty gallon tank may be mounted above the condenser and attached by means of a rubber tube to the cooling water inlet shown at the lower right hand edge of the condenser in Figure 92. A similar tank is placed under the cooling water outlet. The upper tank is then filled with water. When the water has run out of the upper tank through the condenser and into the lower tank, it is poured back into the upper tank. In this way a steady supply of cooling water is obtained. [Fig. 93 Steaming box in which entire battery is set] Another type of steamer uses a steaming box, Figure 93. The battery is placed in the box and steam is sent in through the cover. The boiler has only one steam outlet, and this is connected to the box by means of a hose. [Fig. 94 Special bench for battery steamer] If desired, a special bench may be made for the steaming outfit, as shown in Figure 94. The other tools needed for opening batteries, as given in the list on page 97 are standard articles, and may be obtained at any hardware store, except the terminal tongs, which should be purchased from a battery supply house. [Fig. 95 Battery terminal tongs] Figure 95 illustrates the use of terminal tongs. Battery terminals usually stick so tight that they must be forced out with pliers or other tools. Here is shown a pair of tongs that makes easy work of the job. One end has a fork and the other is shaped to come between the fork. It is placed on the battery terminal, as shown, and when the handles are brought together the terminal attached to the battery lead is forced out without marring any of the parts. EQUIPMENT FOR LEAD BURNING (WELDING) Plate Burning Rack The plates which compose a "group" are joined to the plate connecting strap to which the post is attached. The plates are "burned" to the strap, and this must be done in such a manner that the plates are absolutely parallel, that the distance between plates is correct, and that the top surface of the strap is at right angles to the surface of the plates. These conditions are necessary in order that the positive and negative groups may mesh properly, that the complete element, consisting of the plates and separators may fit in the jar properly, and that the cell covers may fit over the posts easily. [Fig. 96] Fig. 96. Universal Plate Burning Rack. Will Hold Three Groups of Plates at One Time. Designed for Standard and Special Plates In order to secure these conditions, plates that are to be burned to the strap are set in a "burning rack," shown in Figs. 96 and 97, which consists mainly of a base upon which the plate rest, and a slotted bar into which the lugs on the plates fit. The distance between successive slots is equal to the correct distance between the plates of the group. An improved form of burning rack has a wooden base which has slots along the side. The plates are set into these slots and are thus held in the correct position at both top and bottom. [Fig. 97 Plate burning rack for standard 1/8 inch, and thin plates] Fig. 97 shows a rack for use with 1/8 inch and 7-64 inch plates. Fig. 96 shows a "Universal" rack which may be used with both the 1/8 and 7-64 inch plates, and also many special plates. The guide-bar, or "comb," E, has slots along two sides, the base having corresponding slots, as shown. To accommodate different sized plates, the comb may be raised or lowered, and the uprights may be moved back and forth in two slots, one of which is shown at F. In using this rack, the plates are set in position, with their lower edges in the slots of the base, and their lugs in the slots in the comb. The plates are in this way held at opposite corners, and are absolutely straight and parallel. Special fittings are provided to simplify the work of burning. A bar, D, fits along the edge of the comb, and holds the lugs of the plates firmly in the slots. This bar is movable to any part of the comb, being held by two spring clips, C. Two bars, A and B, which are adjustable, make a form around the plate lugs which will prevent the hot lead from running off while burning in the plates. Instructions for burning on plates are given on page 217. The triangular scraper, steel wire brush, coarse files and smoked or blue glasses are all standard articles and may be obtained from any supply house. The burning collars are made of iron, and are set over the end of inter-cell connectors when burning these to the posts, see Figure 98. Experienced repairmen generally do not use them, but those who have trouble with the whole end of the connector melting and the lead running off should use collars to hold in the lead. [Fig. 98 Burning collars] The Burning Lead Mould In every shop there is an accumulation of scrap lead from post drillings, old connecting straps, old plate straps, etc. These should be kept in a special box provided for that purpose, and when a sufficient amount has accumulated, the lead should be melted and run off into moulds for making burning-lead. The Burning Lead Mould is designed to be used for this purpose. As shown in Fig. 99, the mould consists of a sheet iron form which has been pressed into six troughs or grooves into which the melted lead is poured. This sheet iron form is conveniently mounted on a block of wood which has a handle at one end, making it possible to hold the mould while hot without danger of being burned. A sheet of asbestos separates the iron form from the wood, thus protecting the wood from the heat of the melted lead. A hole is drilled in the end of the handle to permit the mould being hung on a nail when not in use. The grooves in the iron form will produce bars of burning lead 15 inches long, 5-16 inch thick, 3/8 inch wide at the top, and 1/4 inch wide at the bottom. [Fig. 99] Fig. 99. Burning-Lead Moulds, and Burning Sticks Cast in Them The advantage of this type of Burning Lead Mould over a cast iron mould is obvious. The form, being made of sheet iron, heats up very quickly, and absorbs only a very small amount of heat from the melted lead. The cast-iron mould, on the other hand, takes so much heat from the melted lead that the latter cools very quickly, and is hard to handle. An iron pot that will hold at least ten pounds of molten lead should be used in melting up lead scraps for burning sticks. When the metal has become soft enough to stir with a clean pine stick skim off the dross. Continue heating metal until slightly yellow on top. With a paddle or ladle drop in a cleaning compound of equal parts of powdered rosin, borax and flower of sulphur. Use a teaspoonful for a ten-pound melting and make sure the compound is perfectly dry. Stir a little and if metal is at proper heat there will be a flare, flash or a little burning. A sort of tinfoil popcorn effect will be noticed floating on top of the metal. Stir until this melts down. Have your ladle hot and skim off soft particles. Dust the mould with mould compound, a powder which makes the lead fill the entire grooves, and not become cool before it does. When everything is ready, fill the ladle and pour the lead into one of the grooves. Hold the ladle above one end of the groove while pouring, and do not move it along the groove. Fill the other grooves in a similar manner. Post Builders. These are moulds which are set over the stumps of posts which have been drilled short in removing the inter-cell connectors. Lead is then melted in with a burning flame to build the post up to the proper height. Figure 100 shows a set of post-builders, and Figure 101 illustrates their use. [Fig. 100 Set of post builders] [Fig. 101 Illustrating use of post builders] EQUIPMENT FOR GENERAL WORK ON CONNECTORS AND TERMINALS Moulds for Casting Inter-Cell Connectors, Terminals, Terminal Screws, Taper Lugs, Plate Straps, Etc. Figure 102 shows a plate strap mould with which three straps and posts may be cast in one minute. It has a sliding movable tooth rack for casting an odd or even number of teeth on the strap. [Fig. 102 Plate strap mould] Figure 103 shows a Link Combination Mould which casts five inter-cell connectors for use on standard 7, 9, 11, 13 and 15 plate batteries, four end connectors (two Dodge tapers, and standard tapers, negative and positive), one end connector with 3/8 inch cable used on 12 volt Maxwell battery and on all other cars a wire cable, and one small wire to connect with end post on batteries requiring direct connection. It also casts two post support rings to fit standard size rubber covers and to fit posts cast with plate strap mould, and two washers which are often needed when installing needed when installing new or rental batteries. [Fig. 103 and Fig. 104: Link combination mould, and castings made in it] Figure 104 shows the parts which may be made with this mould. [Fig. 105 Cell connector mould] [Fig. 106 Production type strap mould] Figure 105 shows a cell connector mould which casts practically all the cell connectors used on standard 7, 9, 11, 13 and 15 plate batteries. This mould is similar to the Link Combination Mould shown in Figure 103. [Fig. 107 Indexing device for strap mould] [Fig. 108 Castings made in strap mould] Figure 106 shows a production type strap mould which is designed to be used by large battery shops. Forty-two styles of straps are, cast by this mould. This mould has an indexing device as shown in Figure 107, which is adjusted by means of a screw for moulding the straps for any number of plates from seven to nineteen. Figure 109 shows some of the castings which are made with this mould. [Fig. 109 Terminal mould and castings made in it] Figure 109 shows a Terminal Mould which casts five reversible end terminal connectors, a cable connector, such as is used on the Maxwell battery, and two washers often needed in making a tight connection. [Fig. 110 Screw mould] Figure 110 shows a Screw Mould which casts standard square lead leads on four screws in one operation, two 5/8 inch and two 3/8 inch. This mould has a screw adjustment in the base which makes each cavity adaptable to any length screw. EQUIPMENT FOR WORK ON CASES The acid proof asphaltum paint, paint brushes, wood chisels, wood plane, and earthenware jars are all standard articles. [Fig. 111 Battery turntable] Figure 111 shows a battery turntable which is very convenient when painting cases, lead burning, etc. TOOLS FOR GENERAL WORK Most of the articles in this list require no explanation. Some of them, however, are of special construction. Separator Cutter. Some battery supply houses sell special separator cutters, but a large size photograph trimmer is entirely satisfactory. [Fig. 112] Fig. 112. Plate Press for Pressing Swollen, Bulged Negatives (After Plates Have Been Fully Charged) [Fig. 113] Fig. 113. Inserting Plate Press Boards Between Negatives Preparatory to Pressing Plate Press. Figure 112 shows a special plate press in which the plates are pressed between wooden jaws. No iron can come into contact with the plates. This is a very important feature, since iron in solution causes a battery to lose its charge very quickly. This press is made of heavy hardwood timbers, and may be set on a bench or mounted on the wall. A set of lead coated troughs carry away the acid which is squeezed from the plates. [Fig. 114 Showing how negatives should be placed in the plate press] This press is designed for pressing negative plates, the active material of which has become bulged or swollen. A plate in this condition has a low capacity and cannot give good service. Swollen negatives often make it impossible to replace the plates in a jar. When negatives are found to be bulged or swollen, the battery must be fully charged, and the negatives then pressed. To do this, plate press boards, which are of acid proof material, and of the proper thickness are inserted between the negatives, as shown in Figure 113, and the plates are then set in the press is shown in Figure 114. [Fig. 115 Negative group before and after pressing] Figure 115 shows a group before and after pressing. Note that pressing has forced the active material back into the grid where it must be if the plates are to give good service. Never send out a battery with swollen or bulged negatives. Slightly buckled negatives may also be straightened out in the Plate Press. Positives do not swell or bulge as they discharge, but shed the active material. They are therefore not pressed Positives buckle, of course, but should never be pressed to straighten them. The lead peroxide of the positive plates is not elastic like the spongy the negatives, and if positives are pressed to straighten them the paste will crack and break from the grid. Slightly buckled positives may be used, but if they are so badly buckled that it is impossible to reassemble the element or put the element back into the jars, they should be discarded. [Fig. 116 Battery carrier] [Fig. 117 Battery truck] Battery Carrier. Figure 116 shows a very convenient battery carrier, having a wooden handle with two swinging steel hooks for attaching to the battery to be carried. With this type of carrier no strain is put on the handle, as is the case if a strap is used. Battery Truck. When a battery must be moved any considerable distance, a truck, such as that shown in Figure 117 should be used. This truck may easily be made in the shop, or may be made at a reasonable cost in a carpenter shop. The rollers should be four inches or more in diameter and should preferably be of the ball-bearing type. Rubber tires on the rollers are a great advantage, since the rubber protects the rollers from acid and also eliminates the very disagreeable noise which iron wheels make, especially in going over a concrete floor or sidewalk. The repairman need not make his truck exactly like that shown in Figure 117, which is merely shown to give a general idea of how such a truck should be constructed. The truck shown in Figure 117 was made from a heavy wooden box. With this construction lifting batteries is largely eliminated, which is most desirable, since a battery is not the lightest thing in the world. The battery is carried in a horizontal position and the truck is small enough to be wheeled between cars in the shop. [Fig. 118 Another battery truck] Another form of battery truck is shown in Figure 118, although this, is not as good as that shown in Figure 117. CADMIUM TEST SET AND HOW TO MAKE THE TEST As the cell voltage falls while the battery is on discharge, the voltage of the positive plates, and also the voltage of the negative plates falls. When the battery is charged again the voltages of both positive and negative plates rise. If a battery gives its rated ampere-hour capacity on discharge, we do not care particularly how the voltages of the individual positive and negative groups change. If, however, the battery fails to give its rated capacity, the fault may be due to defective positives or defective negatives. If the voltage of a battery fails to come up when the battery is put on charge, the trouble may be due to either the positives or negatives. Positives and negatives may not charge at the same rate, and one group may become fully charged before the other group. This may be the case in a cell which has had a new positive group put in with the old negatives. Cadmium tests made while the battery is on charge will tell how fully the individual groups are charged. Since the voltages of the positives and negatives both fall as a battery is discharged, and rise as the battery is charged, if we measure the voltages of the positives and negatives separately, we can tell how far each group is charged or discharged. If the voltage of each cell of a battery drops to 1.7 before the battery has given its rated capacity, we can tell which set of plates has become discharged by measuring the voltages of positives and negatives separately. If the voltage of the positives show that they are discharged, then the Positives are not up to capacity. Similarly, negatives are not up to capacity if their voltage indicates that they are discharged before the battery has given its rated capacity. Cadmium readings alone do not give any indication of the capacity of a battery, and the repairman must be careful in drawing conclusions from Cadmium tests. In general it is not always safe to depend upon Cadmium tests on a battery which has not been opened, unless the battery is almost new. Plates having very little active material, due to shedding, or due to the active material being loosened from the grid, will often give good Cadmium readings, and yet a battery with such plates will have very little capacity. Such a condition would be disclosed by an actual examination of the plates, or by a capacity discharge test. How Cadmium Tests Are Made To measure the voltages of the positives and negatives separately, Cadmium is used. The Cadmium is dipped in the electrolyte, and a voltage reading is taken between the Cadmium and the plates which are to be tested. Thus, if we wish to test the negatives, we take a voltage reading between the Cadmium and the negatives, as shown in Fig. 119. Similarly, if we wish to test the positives, we take a voltage reading between the Cadmium and the positives, as shown in Fig 120. [Fig. 119 Making cadmium test on negative plates] [Fig. 120 Making cadmium test on positive plates] In dipping the Cadmium into the electrolyte, we make two cells out of the battery cell. One of these consists of the Cadmium and the positives, while the other consists of the Cadmium and the negatives. If the battery is charged, the Cadmium forms the negative element in the Cadmium-Positives cell, and is the positive element in the Cadmium-Negatives cell. The voltage of the Cadmium does not change, and variations in the voltage readings obtained in making Cadmium tests are due to changes in the state of charge of the negative and positive plates which are being tested. What Cadmium Is: Cadmium is a metal, just like iron, copper, or lead. It is one of the chemical elements; that is, it is a separate and distinct substance. It is not made by mixing two or more substances, as for instance, solder is made by mixing tin and lead, but is obtained by separating the cadmium from the compounds in which it is found in nature, just as iron is obtained by treatment of iron ore in the steel mill. When Cadmium Readings Should Be Made 1. When the battery voltage drops to 1.7 per cell on discharge before the battery has delivered its rated ampere-hour capacity, at the 5-hour rate when a discharge test is made. 2. When a battery on charge will not "come up," that is, if its voltage will not come up to 2.5-2.7 per cell on charge, and its specific gravity will not come up to 1.280-1.300. 3. Whenever you charge a battery, at the end of the charge, when the voltage and specific gravity no longer rise, make Cadmium tests to be sure that both positives and negatives are fully charged. 4. When you put in a new group, charge the battery fully and make Cadmium tests to be sure that both the new and old groups are fully charged. 5. When a 20-minute high rate discharge test is made. See page 267. That Cadmium Readings should be taken only while a battery is in action; that is, while it is on discharge, or while it is on charge. Cadmium Readings taken on a battery which is on open circuit are not reliable. When you are not using the Cadmium, it should be put in a vessel of water and kept there. Never let the Cadmium become dry, as it will then give unreliable readings. Open Circuit Voltage Readings Worthless Voltage readings of a battery taken while the battery is on open circuit; that is, when no current is passing through the battery, are not reliable. The voltage of a normal, fully charged cell on open circuit is slightly over 2 volts. If this cell is given a full normal discharge, so that the specific gravity of its electrolyte drops to 1.150, and is allowed to stand for several hours after the end of the discharge, the open circuit voltage will still be 2 volts. Open circuit voltage readings are therefore of little or no value, except when a cell is "dead," as a dead cell will give an open circuit voltage very much less than 2, and it may even give no voltage at all. What the Cadmium Test Set Consists of The Cadmium Tester consists of a voltmeter, Fig. 121, and two pointed brass prods which are fastened in wooden handles, as shown in Fig. 122. A length of flexible wire having a terminal at one end is soldered to each prod for attachment to the voltmeter. Fastened at right angles to one of the brass prods is a rod of pure cadmium. [Fig. 121 Special cadmium test voltmeter, & Fig. 122 Cadmium test leads] Cadmium tests may be made with any accurate voltmeter which gives readings up to 2.5 volts in divisions of .05 volt. The instructions given below apply especially to the special AMBU voltmeter but these instructions may also be used in making cadmium tests with any voltmeter that will give the correct reading. The AMBU Cadmium Voltmeter Fig. 121 is a view of the special AMBU Voltmeter, which is designed to be used specially in making Cadmium tests. Fig. 122 shows the Cadmium leads. The four red lines marked "Neg. Charged," "Neg. Discharged," "Pos. Charged," and "Pos. Discharged," indicate the readings that should be obtained. Thus, in testing the positives of a battery on charge, the pointer will move to the line which is marked "Pos. Charged," if the positive plates are fully charged. In testing the negatives, the pointer will move to the line marked "Neg. Charged," which is to the left of the "0" line, if the negatives are fully charged, and so on. Figs. 123, 124, 125 and 126 show the pointer in the four positions on the scale which it takes when testing fully charged or discharged plates. In each figure the pointer is over one of the red lines on the scale. These figures also show the readings, in volts, obtained in making the cadmium tests on fully charged or completely discharged plates. [Fig. 123 Voltmeter showing reading obtained when testing charged negative; & Fig. 124 Showing reading obtained when testing charged positives] [Fig. 125 Voltmeter showing reading obtained when testing discharged negatives; and Fig. 126 Showing reading obtained when testing discharged positives] If Pointer Is Not Over the "0" Line: It sometimes happens, in shipping the instrument, and also in the use of it, that the pointer does not stand over the "0" line, but is a short distance away. Should you find this to be the case, take a small screwdriver and turn the screw which projects through the case, and which is marked "Correct Zero," so as to bring the pointer exactly over the "0" line on the scale while the meter has no wires connected to its binding posts. Connections of Cadmium Leads: In making Cadmium Tests, connect the prod which has the cadmium fastened to it to the negative voltmeter binding post. Connect the plain brass prod to the positive voltmeter binding post. The connections to the AMBU Cadmium Voltmeter are shown in Fig. 127. Testing a Battery on Discharge The battery should be discharging continuously, at a constant, fixed rate, see page 265. [Fig. 127 AMBU Cadmium Voltmeter] Generally, on a starting ability test (see page 267), the positive Cadmium readings will start at about 2.05 volts for a hard or very new set of positives, and at 2.12 volts or even higher for a set of soft or somewhat developed positives, and will drop during the test, ending at 1.95 volts or less. The negative Cadmium readings will start at 0.23 volt or higher, up to 0.30, and will rise gradually, more suddenly toward the end if the plates are old, ending anywhere above 0.35 and up to 0.6 to 0.7 for poor negatives. Short Circuited Cells: In cases of short circuited cells, the voltage of the cell will be almost down to zero. The Cadmium readings would therefore be nearly zero also for both positives and negatives. Such a battery should be opened for inspection and repairs. Testing a Battery on Charge The Battery should be charging at the finishing rate. (This i's usually stamped on the battery box.) Dip the cadmium in the electrolyte as before, and test the negatives by holding the plain prod on the negative post of the cell. See Fig. 119. Test the positives in a similar manner. See Fig. 120. The cell voltage should also be measured. If the positives are fully charged, the positive cadmium reading will be such that the pointer will move to the red line marked "Pos. Charged." See Fig. 125. If you are using an ordinary voltmeter, the meter will give a reading of from 2.35 to 2.42 volts. The negatives are then tested in a similar manner. The negative-cadmium reading on an ordinary voltmeter will be from .175 to .2 to the left of the "0" line; that is, the reading is a reversed one. If you are using the special ABM voltmeter, the pointer will move to the red line marked "Neg. Charged." See Fig. 123. The cell voltage should be the sum of the positive-cadmium and the negative cadmium readings. If the voltage of each cell will not come up to 2.5 to 2.7 volts on charge, or if the specific gravity will not rise to 1.280 or over, make the cadmium tests to determine whether both sets of plates, or one of them, give readings indicating that they are fully charged. If the positives will not give a reading of at least 2.35 volts, or if the negatives will not give a reversed reading of at least 0.1 volt, these plates lack capacity. In case of a battery on charge, if the negatives do not give a minus Cadmium reading, they may be lacking in capacity, but, on the other hand, a minus negative Cadmium reading does not prove that the negatives are up to hill capacity. A starting ability discharge test (page 267) is the only means of telling whether a battery is up to capacity. Improperly treated separators will cause poor negative-Cadmium readings to be obtained. The charging rate should be high enough to give cell voltages of 2.5-2.7 when testing negatives. Otherwise it may not be possible to get satisfactory negative-Cadmium reading. Separators which have been allowed to become partly dry at any time will also make it difficult to obtain satisfactory negative-Cadmium readings. HIGH RATE DISCHARGE TESTERS (See page 265 for directions for making tests.) Figure 128 shows a high rate discharge cell tester. It consists of a handle carrying two heavy prongs which are bridged by a length of heavy nichrome wire. When the ends of the prongs are pressed down on the terminals of a cell, a current of 150 to 200 amperes is drawn from the cell. A voltage reading of the cell, taken while this discharge current is flowing is a means of determining the condition of the cell, since the heavy discharge current duplicates the heavy current drawn by the starting motor. Each prong carries a binding post, a low reading voltmeter being connected to these posts while the test is made. This form of discharge tester is riot suitable for making starting ability discharge tests, which are described on page 267. Other forms of high rate discharge testers are made, but for the shop the type shown in Figure 128 is most convenient, since it is light and portable and has no moving parts, and because the test is made very quickly without making any connections to the battery. Furthermore, each cell is tested separately and thus six or twelve volt batteries may be tested without making any change in the tester. For making starting ability discharge tests at high rates, a carbon plate or similar rheostat is most suitable, and such rheostats are on the market. [Fig. 128 High rate discharge tester] [Fig. 129 Paraffine dip pot] PARAFFINE DIP POT Paper tags are not acid proof, and if acid is spilled on tags tied to batteries which are being repaired, the writing on the tags is often obliterated so that it is practically impossible to identify the batteries. An excellent plan to overcome this trouble is to dip the tags in hot paraffine after they have been properly filled out. The writing on the tags can be read easily and since paraffine is acid proof, any acid which may be spilled on the paraffine coated tags will not damage the tags in any way. Figure 129 shows a paraffine dip pot. A small earthenware jar is best for this purpose. Melt the paraffine slowly on a stove, pour it into the pot, and partly immerse a 60-watt carbon lamp in the paraffine as shown. The lamp will give enough heat to keep the paraffine melted, without causing it to smoke to any extent. After filling out a Battery Card, dip it into the Paraffine, and hold the card above the pot to let the excess paraffine run off. Let the paraffine dry before attaching the tag to the battery, otherwise the paraffine may be scratched off. WOODEN BOXES FOR BATTERY PARTS [Fig. 130] Fig. 130. Boxes for Holding Parts of Batteries Being Prepared Figure 130 shows a number of wooden boxes, about 12 inches long, 8 inches wide, and 4 inches deep. These boxes are very useful for holding the terminals inter-cell connectors, covers, plugs, etc., of batteries which are dismantled for repairs. Write the name of the owner with chalk on the end of the box, and rub the name off after the battery has been put together again. The boxes shown in Figure 130 had been used for plug tobacco, and served the purpose very well. The larger box shown in Figure 130 may be used for collecting old terminals, inter-cell connectors, lead drillings, etc. EARTHENWARE JARS The twenty gallon size is very convenient for waste acid, old separators, and any junk parts which are wet with acid. The jars are acid proof and will help keep the shop floor dry and anything which will help in this is most desirable. ACID CARBOYS Acid is shipped in large glass bottles around each of which a wooden box is built to prevent breakage, the combination being called a "carboy." Since the acid is heavy, some means of drawing it out of the bottle is necessary. One method is illustrated in Figure 131, wooden rockers being screwed to the box in which the bottle is placed. [Fig. 131 A simple method of drawing acid from a carboy] A very good addition to the rockers shown in Figure 131 is the inner tube shown in Figure 132. In this illustration the rockers are not shown, but should be used. The combination of the rockers with the inner tube gives a very convenient method of pouring acid from a carboy, since the heavy bottle need not be lifted, and since it helps keep the floor and the top of the box dry. [Fig. 132 Use of inner tube to protect box when pouring acid] The rubber tube shown in Figure 132 is a piece of 4 inch inner tube which is slit down one side to make it lie flat. Near one end is cut a hole large enough to fit tightly over the neck of the acid bottle. Slip this rubber over the neck of the bottle and allow the long end to hang a few inches over the side of the carboy bottle or box. This is for pouring acid from a carboy when it is too full to allow the contents to be removed without spilling. This device will allow the contents of the carboy to be poured into a crock or other receptacle placed on the floor without spilling, and also prevents dirt that may be laying on top of the carboy from falling into the crock. [Fig. 133 Siphon for drawing acid from carboy] Figure 133 shows a siphon method for drawing acid from a bottle, although this method is more suitable for distilled water than for acid. "A" is the bottle, "B" a rubber stopper, "C" and "D" are 3/8 inch glass or hard rubber tubes, "E" is a length of rubber tubing having a pinch clamp at its lower end. To use this device, the stopper and tubes are inserted in the bottle, and air blown or pumped in at "C," while the pinch clamp is open, until acid or water begins to run out of the lower end of tubing "E." The pinch clamp is then released. Whenever acid or water is to be drawn from the bottle the pinch clamp is squeezed so as to release the pressure on the tube. The water or acid will flow down the tube automatically as long as the pinch clamp is held open. The clamp may be made of flat or round spring brass or bronze. This is bent round at (a). At (c) an opening is made, through which the part (b) is bent. The clamp is operated by pressing at (d) and (e). The rubber tubing is passed through the opening between (b) and (c). This method is a very good one for the small bottle of distilled water placed on the charging bench to bring the electrolyte up to the proper height. The lower end of tube (e) is held over the vent hole of the cell. The pinch clamp is then squeezed and water will flow. Releasing the clamp stops the flow of water instantly. If tube (e) is made long enough, the water bottle may be set on the elevated shelf extending down the center of the charging bench. [Fig. 134 Foot pump for drawing acid from carboy] Figure 134 shows another arrangement, using a tire pump. D and E are 3/8 inch hard rubber tubes. D is open at both ends and has a "T" branch to which the pump tubing is attached. To operate, a finger is held over the upper end of D, and air is pumped into the acid bottle, forcing the acid into the vessel F. To stop the flow of acid, the finger is removed from D. This stops the flow instantly. This method is the most satisfactory one when fairly large quantities of acid or water are to be drawn off. SHOP LAYOUTS The degree of success which the battery repairman attains depends to a considerable extent upon the workshop in which the batteries are handled. It is, of course, desirable to be able to build your shop, and thus be able to have everything arranged as you wish. If you must work in a rented shop, select a place which has plenty of light and ventilation. The ventilation is especially important on account of the acid fumes from the batteries. A shop which receives most of its light from the north is the best, as the light is then more uniform during the day, and the direct rays of the sun are avoided. Fig. 38 shows a light, well ventilated workroom. The floor should be in good condition, since acid rots the wood and if the floor is already in a poor condition, the acid will soon eat through it. A tile floor, as described below, is best. A wooden floor should be thoroughly scrubbed, using water to which baking soda has been added. Then give the floor a coat of asphaltum paint, which should be applied hot so as to flow into all cracks in the wood. When the first coat is dry, several more coats should be given. Whenever you make a solution of soda for any purpose, do not throw it away when you are through with it. Instead, pour it on the floor where the acid is most likely to be spilled. This will neutralize the acid and prevent it from rotting the wood. If you can afford to build a shop, make it of brick, with a floor of vitrified brick, or of tile which is not less than two inches thick, and is preferably eight inches square. The seams should not be less than one-eighth inch wide, and not wider than one fourth. They should be grouted with asphaltum, melted as hot and as thin as possible (not less than 350° F.). This should be poured in the seams. The brick or tile should be heated near the seams before pouring in the asphaltum. When all the seams have been filled, heat them again. After the second heating, the asphaltum may shrink, and it may be necessary to pour in more asphaltum. If possible, the floor should slope evenly from one end of the room to the other. A lead drainage trough and pipe at the lower end of the shop will carry off the acid and electrolyte. It is a good plan to give all work benches and storage racks and shelves at least two coatings of asphaltum paint. This will prevent rotting by the acid. The floor of a battery repair shop is, at best, a wet, sloppy affair, and if a lead drainage trough is too expensive, there should be a drain in the center of the floor if the shop is small, and several if the shop is a large one. The floor should slope toward the drains, and the drain-pipes should be made of glazed tile. To keep the feet as dry as possible, rubbers, or even low rubber boots should be worn. Sulphuric acid ruins leather shoes, although leather shoes can be protected to a certain extent by dipping them in hot paraffine. [Fig. 135 Wooden grating on shop floor to give dry walking surface for the repairman] A good plan is to lay a wooden grating over the floor as shown in Figure 135. Water and acid will run down between the wooden strips, leaving the walking surface fairly dry. If such a grating is made, it should be built in sections which may be lifted easily to be washed, and to permit washing the floor. Keep both the grating and the floor beneath covered with asphaltum paint to prevent rotting by acid. Once a week, or oftener, if necessary, sweep up all loose dirt and then turn the hose on the floor and grating to wash off as much acid as possible. When the wood has dried, a good thing to do is to pour on the floor and grating several pails of water in which washing soda or ammonia has been dissolved. Watch your floor. It will pay-in better work by yourself and by the men working for you. Have large earthenware jars set wherever necessary in which lead drillings, old plates, old connectors, old separators, etc., may be thrown. Do not let junk cases, jars, separators, etc., accumulate. Throw them away immediately and keep your shop clean. A clean shop pleases Your customers, --and satisfied customers mean success. On the following pages a number of shop layouts are given for both large and small shops. The beginner, of course, may not be able to rent even a small shop, but he may rent part of an established repair shop, and later rent an entire shop. A man working in a corner of an established service must arrange his equipment according to the space available. Later on, when he branches out for himself, he should plan his shop to got the best working arrangement. Figure 136 shows a suggested layout for a small shop. Such a layout may have to be altered because of the size and shape of the shop, and the location of the windows. [Fig. 136 Floorplan: layout for a small shop] As soon as growth of business permits, a shop should have a drive-in, so that the customer may bring his car off the street. Without a drive-in all testing to determine what work is necessary will have to be done at the curb, which is too public for many car owners. A drive-in is also convenient if a customer leaves his car while his battery is being repaired. To a certain extent, the advantages of a drive-in may be secured by having a vacant lot next to the shop, with a covering of cinders. As soon as possible, however, a shop which is large enough to have a drive-in should be rented or built. Figure 137 shows a 24 x 60 shop with space for three cars. The shop equipment is explained in the table. Figure 138 shows a 40 x 75 shop with room for six cars and a drive-in and drive-out. This facilitates the handling of the cars. Figure 139 shows a 30 x 100 shop in a long and somewhat narrow building. It also has a drive-in and drive-out. Another arrangement for the same sized shop as shown in the preceding illustration is shown in Figure 140. Here the drive-out is at the side and this layout is, therefore, suitable for a building located on a corner, or next to an alley. Figure 141 shows a larger shop, which may be used after the business has grown considerably. Figure 142 shows a layout suitable for the largest station. Somewhere between Figures 136 and 142 is a layout for any service station. The thing to do is to select the one most suitable for the size of the business, and to fit local conditions, If a special building is put up, local conditions are not so important. If a shop is rented, it may not be possible to follow any of the layouts shown in Figs. 136 to 142. However, the layout which is best adapted for the actual shop should be selected as a guide, and the equipment shown obtained. This should then be arranged as nearly like the pattern layout as the shop arrangement will permit. Concerning Light Light is essential to good work, so you must have plenty of good light and at the right place. For a light that is needed from one end of a bench to the other, to look into each individual battery, or to take the reading of each individual battery, there is nothing better than a 60 Watt tungsten lamp under a good metal shade, dark on outside and white on inside. A unique way to hang a light and have it movable from one end of the bench to the other, is to stretch a wire from one end of the bench to the other. Steel or copper about 10 or 12 B & S gauge may be used. Stretch it about four or five feet above top of bench directly above where the light is most needed. If You have a double charging bench, stretch the wire directly above middle of bench. Before fastening wire to support, slip an old fashioned porcelain knob (or an ordinary thread spool) on the wire. The drop cord is to be tied to this knob or spool at whatever height you wish the light to hang (a few inches lower than your head is the right height). Put the ceiling rosette above center of bench; cut your drop cord long enough so that you can slide the light from one end of bench to the other after being attached to rosette. Put vaseline on the wire so the fumes of gas will not corrode it. This will also make the spool slide easily. This gives you a movable, flexible light, with which you will reach any battery on bench for inspection. The work bench light can be rigged up the same way and a 75 or 100 Watt nitrogen lamp used. [Fig. 137 Shop layout] [Fig. 138 Shop layout] Fig. 137 and 138: A-Receiving Rack. B-Portable Electric Drill, or Hand Drill. C-Wash Tank, D-Tear Down Bench. E-Hot Water Pan. F-Waiting Rack (5 Shelves). G-Repair Bench (6 ft. by 2 ft. 3 in.). H-Charging Table (3 Circuits). I-Electrolyte(10 Gal. Crocks). J-Separator Rack. K-Generator. L-Switchboard. M-Stock Bins, N-New Batteries, O-Live storage. P-Sealing Compound. R-Ready Rack (5-Shelves). S-Dry Storage. (S is not in Fig. 137.) [Fig. 139, 140 & 141 Various shop layouts] Fig. 139, 140 and 141: A-Receiving Rack. B-Power Drill. C-Wash Tank. D-Tear Down Bench. E-Hot Water Pan. F-Waiting Rack (6 Shelves). G-Repair Bench. H-Charging Table (3 Circuits). I-Electrolyte (10 Gal. Crocks). J-Separator Rack. K-Generator. L-Switchboard. M-Stock Bins. N-New Batteries. O-Live storage. P-Sealing Compound. R-Ready Rack (5-Shelves). S-Dry Storage. T-Torn Down Parts. (O and T in 141, not in 139 and 140.) [Fig. 142 Shop layout] Fig. 142: A-Receiving Rack. B-Power Drill. C-Wash Tank. D-Tear Down Bench. E-Hot Water Pan. F-Waiting Rack (6 Shelves). G-Repair Bench. H-Charging Table. I-Electrolyte (10 Gal. Crocks). J-Separator Rack. K-Generator. L-Switchboard. M-Stock Bins. N-New Batteries. O-Live storage. P-Sealing Compound. R-Ready Rack. S-Dry Storage. T-Torn Down Parts. ======================================================================== CHAPTER 12. GENERAL SHOP INSTRUCTIONS. -------------------------- CHARGING BATTERIES. The equipment for charging batteries, instructions for building and wiring charging benches have already been given. What we shall now discuss is the actual charging. The charge a battery receives on the charging bench is called a "bench charge." Battery charging in the service station may be divided into two general classes: 1. Charging batteries which have run down, but which are otherwise in good condition, and which do not require repairs. 2. Charging batteries during or after the repair process. The second class of charging is really a part of the repair process and will-be described in the chapter on "Rebuilding the Battery." Charging a battery always consists of sending a direct current through it, the current entering the battery at the positive terminal and leaving it at the negative terminal, the charging current, of course, passing through the battery in the opposite direction to the current which the battery produces when discharging. When a battery discharges chemical changes take place by means of which electrical energy is produced. When a battery is on charge, the charging current causes chemical changes which are the reverse of those which take place on discharge and which put the active materials and electrolyte in such a condition that the battery serves as a source of electricity when replaced in the car. Batteries are charged not only in a repair shop but also in garages which board automobiles, and in car dealers' shops. No matter where a battery is charged, however, the same steps must be taken and the same precautions observed. When a Bench Charge is Necessary: (a) When a battery runs down on account of the generator on the car not having a sufficient output, or on account of considerable night driving being done, or on account of frequent use of the starting motor, or on account of neglect on the part of the car owner. (b) Batteries used on cars or trucks without a generator, or batteries used for Radio work should, of course, be given a bench charge at regular intervals. (c) When the specific gravity readings of all cells are below 1.200, and these readings are within 50 points of each other. Should the gravity reading of any cell be 50 points lower or higher than that of the other cells, it is best to make a 15-seconds high rate discharge test (see page 266) to determine whether the cell is defective or whether electrolyte has been lost due to flooding caused by over-filling and has been replaced by water or higher gravity electrolyte. If any defect shows up during the high rate test, the battery should be opened for inspection. If no defect shows up, put the battery on charge. (d) When the lamps burn dimly while the engine is running. (e) When the lamps become very dim when the starting switch is closed. If a battery is tested by turning on the lights and then closing the starting switch, make sure that there is no short-circuit or ground in the starting motor circuits. Such trouble will cause a very heavy current to be drawn from the battery, resulting in a drop in the voltage of the battery. (f) When the voltage of the battery has fallen below 1.7 volts per cell, measured while all the lights are turned on. (g) When the owner has neglected to add water to the cells regularly, and the electrolyte has fallen below the tops of the plates. (h) When a battery has been doped by the addition of electrolyte or acid instead of water, or when one of the "dope" electrolytes which are advertised to make old, worn out batteries charge up in a ridiculously short time and show as much life and power as a new battery. Use nothing but a mixture of distilled water and sulphuric acid for electrolyte. The "dope" solutions are not only worthless, but they damage a battery considerably and shorten its life. Such a "doped" battery may give high gravity *readings and yet the lamps will become very dim when the starting motor cranks the car, the voltage per cell will be low when the lights are burning, or low voltage readings (1.50 per cell) will be obtained if a high rate discharge test is made. Every battery which comes in for any reason whatsoever, or any battery which is given a bench charge whenever necessary should also be examined for other defects, such as poorly burned on connectors and terminals, rotted case, handles pulled off, sealing compound cracked, or a poor sealing job between the covers and jars, or covers and posts. A slight leakage of electrolyte through cracks or imperfect joints between the covers and jars or covers and posts is very often present without causing any considerable trouble. If any of the other troubles are found, however, the battery needs repairing. Arrangement of Batteries on Charging Bench. If a battery comes in covered with dirt, set it on the wash rack or in the sink and clean it thoroughly before putting it on charge. In setting the batteries on the charging bench, place all of them so that the positive terminal is toward the right as you face the bench. The positive terminal may be found to be painted red, or may be stamped "+", "P", or "POS". If the markings on one of the terminals has been scratched or worn off, examine the other terminal. The negative terminal may be found to be painted black, or be stamped "-", "N" or "NEG". If neither terminal is marked, the polarity may be determined with a voltmeter, or by a cadmium test. To make the voltmeter test, hold the meter wires on the battery terminals, or the terminals of either end cell. When the voltmeter pointer moves to the right of the "0" line on the scale, the wire attached to the "+" terminal of the meter is touching the positive battery terminal, and the wire attached to the "-" terminal of the meter is touching the negative battery terminal. If this test is made with a meter having the "0" line at the center of the scale, be sure that you know whether the pointer should move to the left or right of the "0" line when the wire attached to the "+" meter terminal is touching the positive battery terminal. Another method of determining which is the positive terminal of the battery is to use the cadmium test. When a reading of about two volts is obtained, the prod held on one of the cell terminals is touching the positive terminal. When a reading of almost zero is obtained, that is, when the needle of the meter just barely moves from the "0" line, or when it does not move at all, the prod held on one of the cell terminals is touching the negative terminal. This test, made while the battery is on open-circuit, is not a regular cadmium test, but is made merely to determine the polarity of the battery. The polarity of the charging line will always be known if the bench is wired permanently. The positive charging wire should always be to the right. If a separate switch is used for each battery (Figures 43 and 65), the wire attached to the right side of the switch is positive. If the batteries are connected together by means of jumpers (Figures 44 and 47), the positive charging wire should be at the right hand end of the bench as seen when facing the bench. If a constant-potential charging circuit is used as shown in Figure 48, the positive bus-bar should be at the top and the neutral in the center, and the negative at the bottom. If the polarity of the charging line wires is not known, it may be determined by a voltmeter, in the same way as the batter-, polarity is determined. If this is done, care should be taken to use a meter having a range sufficient to measure the line voltage. If no such voltmeter is available, a simple test is to fill a tumbler with weak electrolyte or salt water and insert two wires attached to the line. The ends of these wires should, of course, be bare for an inch or more. Hold these wires about an inch apart, with the line alive. Numerous fine bubbles of gas will collect around the negative wire. With the polarities of all the batteries known, arrange them so that all the positive terminals are at the right. Then connect them to the individual switches (see Figure 43), or connect them together with jumpers (see Figure 44), being sure to connect the negative of one battery to the positive of the next. Connect the positive charging line wire to the positive terminal of the first battery, and the negative line wire to the negative terminal of the last battery. See page 105. With all connections made, and before starting to charge, go over all the batteries again very carefully. You cannot be too careful in checking the connections, for if one or more batteries are connected reversed, they will be charged in the wrong direction, and will most likely be severely damaged. As a final check on the connections of the batteries on the line, measure the total voltage of these batteries and see if the reading is equal to two times the total number of cells on the line. Now inspect the electrolyte in each cell. If it is low, add distilled water to bring the electrolyte one-half inch above the plates. Do not wait until a battery is charged before adding water. Do it now. Do not add so much water that the electrolyte comes above the lower end of the vent tube. This will cause flooding. Charging, Rate. If you connect batteries of various sizes together on one circuit, charge at the rate which is normal for the smallest battery. If the rate used is the normal one for the larger batteries, the smaller batteries will be overheated and "boiled" to death, or they may gas so violently as to blow a considerable portion of the active material from the plates. It is quite possible to charge 6 and 12 volt batteries in series. The important point is not to have the total number of cells too high. For instance, if the 10 battery Tungar is used, ten 6-volt batteries (30 cells), or any combination which gives 30 cells or less may be used. For instance, five 12-volt batteries (30 cells), or six 6-volt batteries (18 cells) and two 12-volt batteries (12 cells), or any other combination totaling 30 cells may be used. The same holds true for motor-generators. The charging rate is generally determined by the size of the charging outfit. The ten battery Tungar should never have its output raised above 6 amperes. A charging rate of 6 amperes is suitable for all but the very smallest batteries. In any case, whether you are certain just what charging rate to use, or not, there are two things which will guide you, temperature and gassing. 1. Temperature. Have a battery thermometer (Figure 37) on hand, and measure the temperature of the electrolyte of each cell on the line. If you note that some particular cell is running hotter than the others, keep the thermometer in that cell and watch the temperature. Do not let the temperature rise above 110 degrees Fahrenheit, except for a very short time. Should the highest of the temperature of the cells rise above 110 degrees, reduce the charging rate. 2. Gassing. Near the end of a charge and when the specific gravity has stopped rising, or is rising very slowly, bubbles of gas will rise from the electrolyte, this being due to the charging current decomposing the water of the electrolyte into hydrogen and oxygen. If this gassing is too violent, a considerable amount of active material will be blown from the plates. Therefore, when this gassing begins, the charging rate should be reduced, unless the entire charging has been done at a low rate, say about five amperes. If gassing begins in any cell soon after the charge is started, or before the specific gravity has reached its highest point, reduce the charging rate to eliminate the gassing. If one battery or one cell shows a high temperature and the others do not, or begins gassing long before the others do, remove that battery from the charging line for further investigation and replace it with another so as not to slow up the charge of the other batteries which are acting normally. As long as excessive temperatures and too-early gassing are avoided, practically any charging rate may be used, especially at the start. With a constant potential charging set, as shown in Figure 48, the charge may start at as high a rate as 50 amperes. If this system of charging is used, the temperature must be watched very carefully and gassing must be looked for. With the usual series method of charging, a charge may, in an emergency, be started at 20 amperes or more. As a general rule do not use a higher rate than 10 amperes. A five ampere rate is even better, but more time will be required for the charge. Time Required for a Charge. The time required is not determined by the clock, but by the battery. Continue the charge until each cell is gassing freely (not violently) and for five hours after the specific gravity has stopped rising. The average condition of batteries brought in for charge permits them to be fully charged in about 48 hours, the time being determined as stated above. Some batteries may charge fully in less time, and some may require from four days to a week, depending entirely upon the condition of the batteries. Do not give any promise as to when a recharge battery will be ready. No one can tell how long it will take to charge. Specific Gravity at the End of the Charge. The specific gravity of the electrolyte in a fully charged cell should be from 1.280 to 1.300. If it varies more than 10 points above or below these values, adjust it by drawing off some of the electrolyte with a hydrometer and adding water to lower the gravity, or 1.400 acid to raise the gravity. After adjusting the gravity charge for one hour more. Battery Voltage at End of Charge. The voltage of a fully charged cell is from 2.5 to 2.7 when the temperature of the electrolyte is 80 degrees Fahrenheit; 2.4 to 2.6 when the temperature of the electrolyte is 100 degrees Fahrenheit, and 2.35 to 2.55 volts when the temperature of the electrolyte is 120 degrees Fahrenheit, and this voltage, together with hydrometer readings of 1.280-1.300 indicate that the battery is fully charged. Just before putting a battery which has been charged into service, give it a 15 seconds high rate discharge test, see page 266. Painting. Before returning a battery to the owner wipe it perfectly clean and dry. Then wipe the covers, terminals, connectors and handles with a rag wet with ammonia. Next give the case a light coat of black paint which may be made by mixing lamp black and shellac. This paint dries in about five minutes and gives a good gloss. The customer may not believe that you are returning the battery which he brought in but he will most certainly be pleased with your service and will feel that if you take such pains with the outside of his battery you will certainly treat the inside with the same care when repairs are necessary. The light coat of paint costs very little for one battery, but may bring you many dollars worth of work. Level of Electrolyte. During charge the electrolyte will expand, and will generally flow out on the covers. This need not be wiped off until the end of the charge. When the electrolyte has cooled after the battery is taken off charge, it must be about 1/2 inch above the plates. While the electrolyte is still warm it will stand higher than this, but it should not be lowered by drawing off some of it, as this will probably cause it to be below the tops of the plates and separators when it cools. TROUBLES If all goes well, the charging process will take place as described in the preceding paragraphs. It frequently happens, however, that all does not go well, and troubles arise. Such troubles generally consist of the following: Specific gravity will not rise to 1.280. This may be due to the plates not taking a full charge, or to water having been used to replace electrolyte which has been spilled. To determine which of these conditions exist, make cadmium test (see page 174) on the positives and negatives, also measure the voltage of each cell. If these tests indicate that the plates are fully charged (cell voltage 2.5 to 2.7, Positive-Cadmium 2.4 volts, Negative-Cadmium minus 0.15 to 0.20 volts), you will know that there is not enough acid in the electrolyte. The thing to do then is to dump out the old electrolyte, refill with 1.300 electrolyte and continue the charge until the specific gravity becomes constant. Some adjustment may then have to be made by drawing off some of the electrolyte with a hydrometer and adding water to lower the gravity, or 1.400 acid to bring it up. Remember that specific gravity readings tell you nothing about the plates, unless it is known that the electrolyte contains the correct proportions of water and acid. The cadmium test is the test which tells you directly whether or not the plates are charged and in charging a battery the aim is to charge the plates, and not merely to bring the specific gravity to 1.280. If the specific gravity will not rise to 1.280 and cadmium tests show that the plates will not take a full charge, then the battery is, of course, defective in some way. If the battery is an old one, the negatives are probably somewhat granulated, the positives have probably lost much of their active material, resulting in a considerable amount of sediment in the jars, and the separators are worn out, carbonized, or clogged with sediment. Such a battery should not be expected to give as good service as a new one, and the best thing to do if the tests show the battery to be more than half charged, is to put it back on the car, taking care to explain to the owner why his battery will not "come up" and telling him that he will soon need a new battery. Remember that improperly treated separators, or defective separators will cause poor Negative-Cadmium readings to be obtained. If a fairly new battery will not take a full charge, as indicated by hydrometer readings and cadmium tests, some trouble has developed due to neglect, abuse, or defect in manufacture. If all cells of a fairly new battery fail to take a full charge within 48 hours, the battery has probably been abused by failing to add water regularly, or by allowing battery to remain in an undercharged condition. Such a battery should be kept on the line for several days more, and if it then still will not take a full charge the owner should be told what the condition of the battery is, and advised to have it opened for inspection. If one cell of a battery fails to take a charge, but the other cells charge satisfactorily, and cadmium tests show that the plates of this cell are not taking a charge, the cell should be opened for inspection. If one cell of a battery charges slowly, cut the other cells out of the line, and charge the low cell in series with the other batteries on the charging line. If all cells of a battery, whether new or old, will not take even half a charge, as indicated by hydrometer readings (1.200), the battery should be opened for inspection. If the gravity of a battery on charge begins to rise long before the voltage rises, and if the gravity rises above 1.300, there is too great a proportion of acid in the electrolyte. The remedy is to dump out the electrolyte, refill with pure water and continue the charge at a lower rate than before, until the specific gravity stops rising. Then charge for ten hours longer, dump out the water (which has now become electrolyte by the acid formed by the charging current), refill with about 1.350 electrolyte and continue the charge, balancing the gravity if necessary at the end of the charge. If a battery becomes very hot while on charge at a rate which is not normally too high for the battery, it indicates that the battery is badly sulphated, or has a partial short-circuit. Gassing generally goes with the high temperature. If you can detect a vinegar-like odor rising from the vent holes, you may be absolutely sure that the separators used in that battery have developed acetic acid due to not having received the proper treatment necessary to prepare them for use in the battery. The electrolyte should be dumped from such a battery immediately and the battery should be filled and rinsed with water several times. Then the battery should be opened without loss of time, to see whether, by removing the separators and washing the plates thoroughly, the plates may be saved. If the acetic acid has been present for any length of time, however, the plates will have been ruined beyond repair, the lead parts being dissolved by the acid. If the electrolyte of a battery on charge has a white, milky look, there may be impurities which cause numerous minute bubbles to form, such bubbles giving the electrolyte its milky appearance. The milky appearance may be due to the use of "hard" water in refilling, this water containing lime. The electrolyte as seen with the acid of an electric lamp or flashlight should be perfectly clear and colorless. Any scum, particles of dirt, any color whatsoever shows that the electrolyte is impure. This calls for dumping out the electrolyte, filling and rinsing with pure water, refilling with new electrolyte and putting the battery back on the charging line. Of course, this may not cause the battery to charge satisfactorily, which may be due to the troubles already described. Should it ever happen that it is impossible to send a current through a charging circuit go over all the connections to make sure that you have good contact at each battery terminal, and that there are no loose inter-cell connectors. If all connections to the batteries are good, and there are no loose inter-cell connectors, cut out one battery at a time until you start the current flowing, when you cut out some particular battery. This battery should then be opened without further tests, as it is without a doubt in a bad condition. The conditions which may exist when a battery will not charge, as shown especially by cadmium tests, are as follows: (a) The battery may have been allowed to remain in a discharged condition, or the owner may have neglected to add water, with the result that the electrolyte did not cover the plates. In either case a considerable amount of crystallized sulphate will have formed in the plates. Plates in such a condition will require a charge of about a week at a low rate and will then have to be discharged and recharged again. Several such cycles of charge and discharge may be necessary. It may even be impossible to charge such a battery, no matter how many cycles of charge and discharge are given. If the owner admits that his battery has been neglected and allowed to stand idle for a considerable time, get his permission to open the battery. (b) The battery may have been overheated by an excessive charging rate, or by putting it on a car in a sulphated condition. The normal charging rate of the generator on the car will over heat a sulphated battery. Overheated plates buckle their lower edges cut through the separators, causing a short-circuit between plates. (c) The pockets in the bottoms of the jars may have become filled with sediment, and the sediment may be short-circuiting the plates. (d) Impurities may have attacked the plates and changed the active materials to other substances which do not form a battery. Such plates may be so badly damaged that they are brittle and crumbled. Acetic acid from improperly treated separators will dissolve lead very quickly, and may even cause an open circuit in the cell. (e) The conditions described in (a), (b), and (c) will permit a charging current to pass through the battery, but the plates will not become charged. It is possible, of course, but not probable, that a condition may exist in which all the plates of one or both groups of a cell may be broken from the connecting straps, or inter-cell connectors may be making no contact with the posts. In such a case, it would be impossible to send a charging current through the battery. Acetic acid from improperly treated separators, and organic matter introduced by the use of impure water in refilling will attack the lead of the plates, especially at the upper surface of the electrolyte, and may dissolve all the plate lugs from the connecting straps and cause an open-circuit. (f) The separators may be soggy and somewhat charred and blackened, or they may be clogged up with sulphate, and the battery may need new separators. (g) The spongy lead may be bulged, or the positives may be buckled. The active material is then not making good contact with the grids, and the charging current cannot get at all the sulphate and change it to active material. The remedy in such a case is to press the negatives so as to force the active material back into the grids, and to put in new positives if they are considerably buckled. (h) One of the numerous "dope" electrolytes which are offered to the trustful car owner may have been put in the battery. Such "dopes" might cause very severe damage to the plates. Tell your customers to avoid using such "dope." The conditions which may exist when the plates of a battery take a charge, as indicated by cadmium tests, but the gravity will not come up to 1.280 are as follows: (a) There may be considerable sediment in the jars but not enough to short circuit the plates. If the battery has at some time been in a sulphated condition and has been charged At too high a rate, the gassing that resulted will have caused chips of the sulphate to drop to the bottom of the jars. When this sulphate was formed, some of the acid was taken from the electrolyte, and if the sulphate drops from the plates, this amount of acid cannot be recovered no matter how long the charge is continued. If the owner tells you that his battery has stood idle for several months at some time, this is a condition which may exist. The remedy is to wash and press the negatives, wash the positives, put in new separators, pour out the old electrolyte and wash out the jars, fill with 1.400 acid, and charge the battery. (b) Impurities may have used up some of the acid which cannot be recovered by charging. If the plates are not much damaged the remedy is the same as for (a). Damaged plates may require renewal. (c) Electrolyte may have been spilled accidentally and replaced by water. (d) Too much water may have been added, with the result that the expansion of the electrolyte due to a rise in temperature on charge caused it to overflow. This, of course, resulted in a loss of some of the acid. The causes given in (c) and (d) may have resulted in the top of the battery case being acid-eaten or rotted. The remedy in these two instances is to draw off some of the electrolyte, add some 1.400 acid and continue the charge. If plates and separators look good and there is but little sediment, this is the thing to do. If Battery will not hold a Charge. If a battery charges properly but loses its charge in a week or less, as indicated by specific gravity readings, the following troubles may exist: (a) Impurities in the cells, due to the use of impure water in the electrolyte, or in the separators. Some impurities (see page 76) do not attack the plates, but merely cause self-discharge. The remedy is to dump out the old electrolyte, rinse the jars with pure water, fill with new electrolyte of the same gravity as the old and recharge. If this does not remove impurities, the battery should be opened, the plates washed, jars cleaned out, new separators put in, and battery reassembled and charged. (b) There may be a slow short-circuit, due to defective separators or excessive amount of sediment. If preliminary treatment in (a) does not cause battery to hold charge, the opening of battery and subsequent treatment will remove the cause of the slow short-circuit. Suggestions 1. Make sure every battery is properly tagged before going on line. 2. Determine as quickly as possible from day to day, those batteries that will not charge. Call owner and get permission to open up any such battery and do whatever is necessary to put it in good shape. 3. As soon as a battery charges to 1.280-1.300, the voltage is 2.5-2.7 per cell and the cadmium readings are 2.4 or more for the positives and -0.15 to -0.20 for the negatives and the gravity voltage and cadmium readings do not change for five hours, remove it from the line as finished and replace it with another if possible. Go over your line at least three times a day and make gravity, temperature, and cadmium tests. 4. Make a notation, with chalk, of the gravity of each cell each morning. Do not trust to memory. 5. Remove from the line as soon as possible any battery that has a leaky cell and neutralize with soda the acid that has leaked out. 6. Batteries that are sloppers, with rotten cases, and without handles are sick and need a doctor. Go after the owner and get permission to repair. 7. Keep the bench orderly and clean. 8. Remember that if you have a line only partly full and have other batteries waiting to be charged you are losing money by not keeping a full line. 9. Leave the Vent Plugs in When Charging. The atmosphere in many service stations, where the ventilation is poor, is so filled with acid fumes that customers object to doing business there. The owners of these places may not notice these conditions, being used to it, or rather glory in being able to breathe such air without coughing or choking, but it certainly does not invite a customer to linger and spend his money. The remedy for such a condition is to leave the vent plugs in place on the batteries that are charging so that the acid spray in the gas from the battery condenses out as it strikes these plugs and drips back into the cells, while the gas passes out through the small openings in the plug. The plugs need only be screwed into the openings by one turn, or only set on top of the vent openings to accomplish the result. This takes no additional time and more than repays for itself in the saving of rusted tools and improved conditions in the battery room and surroundings. In charging old Exide batteries, be sure to replace the vent plugs and turn them to open the air passages which permit the escape of gases which form under the covers. If you wish to keep these air passages open without replacing the plugs, which may be done for convenience, give the valve (see page 21) a quarter turn with a screwdriver or some other tool. 10. If the electrolyte from a battery rises until it floods over the top of the jar, it shows that too much water was added when the battery was put on charge, the water rising to the bottom of the vent tube, thereby preventing gases formed (except those directly below the vent hole) from escaping. This gas collects under the covers, and its pressure forces the electrolyte up into the vent hole and over the top of the battery. In charging old U.S.L. batteries it is especially necessary to keep the air vent (see page 20) open to prevent flooding, since the lower end of the vent tube is normally a little below the surface of the electrolyte. Remember, do not have the electrolyte come up to the lower end of the vent tube. NOTE: To obtain satisfactory negative cadmium readings, the charging rate should be high enough to give a cell voltage of 2.5-2.7. Improperly treated separators, or separators which have been allowed to become partly dry at any time will make it impossible to obtain satisfactory negative cadmium readings. LEAD BURNING (WELDING) Lead cannot be "burned" in the sense that it bursts into flame as a piece of paper does when a match is applied to it. If sufficient heat is applied, the lead will oxidize and feather away into a yellow looking dust, but it does not burn. The experienced battery man knows that by "lead burning" is meant the heating of lead to its melting point, so that two lead surfaces will weld together. This is a welding and not a "burning" process, and much confusion would be avoided if the term "lead welding" were used in place of the term "lead burning." The purpose of welding lead surfaces together is to obtain a joint which offers very little resistance to the flow of current, it being absolutely necessary to have as low a resistance as possible in the starting circuit. Welding also makes joints which are strong mechanically and which cannot corrode or become loose as bolted connections do. Some earlier types of starting and lighting batteries had inter-cell connectors which were bolted to the posts, but these are no longer used. The different kinds of lead-burning outfits are listed on page 143 The oxygen-acetylene and the oxygen-hydrogen flames give extremely high temperatures and enable you to work fast. Where city gas is available, the oxygen illuminating gas combination will give a very good flame which is softer than the oxygen acetylene, oxygen-hydrogen outfits. Acetylene and compressed air is another good combination. There are two general classes of lead-welding: (a) Welding connecting bars, called "cell" connectors, top connectors, or simply "connectors," to the posts which project up through the cell covers, and welding terminals to the end posts of a battery. (b) Welding plates to "straps" to form groups. The straps, of course, have joined to them the posts which project through the cell covers and by means of which cells are connected together, and connections made to the electrical system of the car. In addition to the above, there are other processes in which a burning (welding) flame is used: (c) Post-building, or building posts, which have been drilled or cut short, up to their original size. (d) Extending plate lug. If the lug which connects a plate to the plate strap is too short, due to being broken, or cut too short, the lug may be extended by melting lead into a suitable iron form placed around the lug. (e) Making temporary charging connections between cells by lightly welding lead strips to the posts so as to connect the cells together. (f) A lead-burning (welding) flame is also used to dry out the channel in cell covers before pouring in the sealing compound, in re-melting sealing compound which has already been poured, so as to assure a perfect joint between the compound cover and jar, and to give the compound a smooth glossy finish. These processes are not welding processes and will not be described here. General Lead Burning Instructions Flame. With all the lead burning outfits, it is possible to adjust the pressures of the gases so as to get extremely hot, medium, and soft flames. With the oxygen-acetylene, or oxygen-hydrogen flame, each gas should have a pressure of about two pounds. With the oxygen-illuminating gas flame, the oxygen should have a pressure of 8 to 10 pounds. The city gas then does not need to have its pressure increased by means of a pump, the normal pressure (6 to 8 ounces) being satisfactory. Various makes of lead-burning outfits are on the market, and the repairman should choose the one which he likes best; since they all give good results. All such outfits have means of regulating the pressures of the gases used. With some the gases are run close to the burning tip before being mixed, and have an adjusting screw where the gases mix. Others have a Y shaped mixing valve at some distance from the burning tip, as shown in Figure 78. Still others have separate regulating valves for each gas line. With these adjustments for varying the gas pressure, extremely hot, hissing flames, or soft flames may be obtained. For the different welding jobs, the following flames are suitable: 1. A sharp, hissing flame, having a very high temperature is the one most suitable for the first stage in welding terminals and connectors to the posts. 2. A medium flame with less of a hiss is suitable for welding plates to strips and lengthening plate lugs. 3. A soft flame which is just beginning to hiss is best for the finishing of the weld between the posts and terminals or connectors. This sort of a flame is also used for finishing a sealing job, drying out the cover channels before sealing, and so on. In adjusting the burning flame, 4 the oxygen is turned off entirely, a smoky yellow flame is obtained. Such a flame gives but little heat. As the oxygen is gradually turned on the flame becomes less smoky and begins to assume a blue tinge. It will also be noticed that a sort of a greenish cone forms in the center portion of the flame, with the base of the cone at the torch and the tip pointed away from the torch. At first this inner-cone is long and of almost the same color as the outer portion of the flame. As the oxygen pressure is increased, this center cone becomes shorter and of a more vivid color, and its tip begins to whip about. When the flame is at its highest temperature it will produce a hissing sound and the inner cone will be short and bright. With a softer flame, which has a temperature suitable for welding plates to a strap, the inner cone will be longer and less vivid, and the hissing will be greatly diminished. The temperature of the different parts of the flame varies considerably, the hottest part being just beyond the end of the inner cone. Experience with the particular welding outfit used will soon show how far the tip of the torch should be held from the lead to be melted. Cleanliness. Lead surfaces which are to be welded together must be absolutely free from dirt. Lead and dirt will not mix, and the dirt will float on top of the lead. Therefore, before trying to do any lead welding, clean the surfaces which are to be joined. The upper ends of plate lugs may be cleaned with a flat file, knife., or wire brush. The posts and inter-cell connectors should be cleaned with a knife, steel wire brush, or triangular scraper. Do not clean the surfaces and then wait a long time before doing the lead burning. The lead may begin to oxidize if this is done and make it difficult to do a good job. The surfaces which are to be welded together should also be dry. If there is a small hole in the top of a post which is to be welded to a connector or terminal, and this hole contains acid, a shower of hot lead may be thrown up by the acid, with possible injury to the operator. Do not try to save time by attempting to weld dirty or wet lead surfaces, because time cannot be saved by doing so, and you run the risk of being injured if hot lead is thrown into your face. Remove absolutely every speck of dirt--you will soon learn that it is the only way to do a good job. Safety Precautions. Remove the vent plugs and blow down through the vent holes to remove any gases which may have collected above the surface of the electrolyte. An explosion may result if this is not done. To protect the rubber covers, you may cover the whole top of the battery except the part at which the welding is to be done, with a large piece of burlap or a towel which has been soaked in water. The parts covered by the cloth must be dried thoroughly if any welding on them. Instead of using a wet cloth, a strip of asbestos may be laid over the vent holes, or a small square of asbestos may be laid over each vent hole. Burning on the Cell Connectors and Terminals Have the posts perfectly clean and free from acid. Clean the tops, bottoms and sides of the connectors with a wire brush, Figure 143. Finish the top surfaces with a coarse file, Figure 144. With a pocket knife clean the inside surfaces of the connector holes. Place the connectors and terminals in their proper positions on the posts, and with a short length of a two by two, two by one, or two by four wood pound them snugly in position, Figure 145. Be sure that the connectors are perfectly level and that the connectors are in the correct position as required on the car on which the battery is to be used. The top of the post should not come flush with the top of the connector. Note, from Figure 146, that the connector has a double taper, and that the lower tapered surface is not welded to the post. If the post has been built up too high it should be cut down with a pair of end cutting nippers so that the entire length of the upper taper in the connector is in plain sight when the connector is put in position on the post. This is shown in Figure 146. With the connectors in place, and before welding them to the posts, measure the voltage of the whole battery to be sure that the cells are properly connected, as shown by the voltage reading being equal to two times the number of cells. If one cell has been reversed, as shown by a lower voltage reading now is the time to correct the mistake. [Fig. 143 Brushing connector before burning in] [Fig. 144 Rasping connector before burning in] The connectors and terminals are now ready to be welded to the posts. Before bringing any flame near the battery be sure that you have blown out any gas which may have collected under the covers. Then cover the vents with asbestos or a wet cloth as already described. You will need strips of burning lead, such as those made in the burning lead mould described on page 164. Use a hot, hissing flame for the first stage. With the flame properly adjusted, hold it straight above the post, and do not run it across the top of the battery. Now bring the flame straight down over the center of the post, holding it so that the end of the inner cone of the flame is a short distance above the post. When the center of the post begins to melt, move the flame outward with a circular motion to gradually melt the whole top of the post, and to melt the inner surface of the hole in the connector. Then bring the lower end of your burning lead strip close to and over the center of the hole, and melt in the lead, being sure to keep the top of the post and the inner surface of the hole in the connector melted so that the lead you are melting in will flow together and unite. Melt in lead until it comes up flush with the upper surface of the connector. Then remove the flame. This completes the first stage of the welding process. Now repeat the above operation for each post and terminal. [Fig. 145 Leveling top connectors before burning in] It is essential that the top of the post and the inner surface of the hole in the connector be kept melted as long as you are running in lead from the strip of burning lead. This is necessary to have all parts fuse together thoroughly. If you allow the top of the post, or the inner surface of the hole in the connector to chill slightly while you are feeding in the lead, the parts will not fuse, and the result will be a poor Joint, which will heat up and possibly reduce the current obtained from the battery when the starting switch is closed. This reduction may prevent the starting motor from developing sufficient torque to crank the engine. When the joint cools, the lead will shrink slightly over the center of the posts. To finish the welding, this lead is to be built up flush or slightly higher than the connector. Brush the tops of the post and connector thoroughly with a wire brush to remove any dirt which may have been floating in the lead. (Dirt always floats on top of the lead.) Soften the burning flame so that it is just barely beginning to hiss. Bring the flame down over the center of the post. When this begins to melt, move the flame outward with a circular motion until the whole top of post and connector begins to melt and fuse. If necessary run in some lead from the burning lead strip. When the post and connector are fused, clear to the outer edge of the connector, raise the flame straight up from the work. [Fig. 146 Connector in position on post for for welding to post. Surfaces A-B are not welded together] You will save time by doing the first stage of the burning on all posts first, and then finish all of them. This is quicker than trying to complete both stages of burning on each post before going to the next post. The object in the finishing stage is to melt a thin layer of the top of post and connector, not melting deep enough to have the outer edge of the connector melt and allow the lead to run off. All this must be done carefully and dexterously to do a first-class job, and you must keep the flame moving around over the top and not hold it in any one place for ally length of time, so as not to melt too deep, or to melt the outer edge and allow the lead to run off and spoil the job. Sometimes the whole mass becomes too hot and the top cannot be made smooth with the flame. If this occurs wait until the connector cools, soften the flame, and try again. Figure 147 shows the welding completed. [Fig. 147 Connectors "burned" to posts] Burning Plates to Strap and Post First clean all the surfaces which are to be welded together. Take your time in doing this because you cannot weld dirty surfaces together. Plates which compose a group are welded to a "strap" to which a post is attached, as shown in Figure 5. The straps shown in Figure 5 are new ones, as made in the factory. Plate lugs are set in the notches in the straps and each one burned in separately. In using old straps from a defective group, it is best to cut the strap close to the post, thus separating all the plates from the post in one operation, as was done with the post shown in Figure 96. If only one or two plates are to be burned on, they are broken or cut off and slots cut in the strap to receive the lugs of the new plates, as shown in Figures 148 and 149. [Fig. 148 Sawing slot in plate strap] Set the plates in a plate burning rack, as shown in Figure 96, placing the adjustable form around the lugs and strap as shown in this figure. Be sure to set the post straight, so that the covers will fit. A good thing is to try a cover over the post to see that the post is set up properly. The post must, of course, be perpendicular to the tops of the plates. If the slotted plate strap shown in Figure 5 is used, or if one or two plates have been cut off, melt the top of the lug of one of the plates which are to be burned oil, and the surfaces of the strap to which the plate is to be welded. Melt in lead from a burning-lead strip to bring the metal up flush with the surface of the strap. Proceed with each plate which is to be burned on. If all the plates have been sawed from the strap, leaving the post with a short section of the strap attached, as shown in Figure 96, melt the edge of the strap, and the top of one or two of the end plate lugs and run in lead from the burning strip to make a good joint. Proceed in this way until all the lugs are joined to the strap and then run the flame over the top of the entire strap to make a smooth uniform weld. Be sure to have the lower edge of the strap fuse with the plate lugs and then run in lead to build the strap up to the proper thickness. Raise the flame occasionally to see that all parts are fusing thoroughly and to prevent too rapid heating. [Fig. 149 Slotting saw, a group with two plates cut off, and slots in strap for new plates] When enough lead has been run in to build the strap tip to the correct thickness and the plate lugs are thoroughly fused with the strap, raise the flame straight up from the work. Allow the lead to "set" and then remove the adjustable form and lift the group from the burning rack. Turn the group up-side-down and examine the bottom of the strap for lead which ran down the lugs during the welding process. Cut off any such lead with a saw, as it may cause a short-circuit when the plates are meshed with the other group. Post Building In drilling down through the inter-cell connectors to separate them from the posts in opening a battery, the posts may be drilled too short. In reassembling the battery it is then necessary to build the posts up to their original height. This is done with the aid of post-builders, shown in Figure 100. Clean the stub of the post thoroughly and also clean the inside of the post builder. Then set the post builder carefully over the stub post, so that the upper surface of the post builder is parallel to the upper surface of the plate strap. The built up post will then be perpendicular to the surface of the strap, which is necessary, in order to have the covers and connectors fit properly. With the post builder set properly adjust the burning torch to get a sharp, hissing flame. Bring the flame straight down on the center of the post stub. When the center of the post stub begins to melt, move the flame outward with a circular motion until the whole top of the stub begins to melt. Then run in lead from a burning lead strip, Figure 101, at the same time keeping the flame moving around on the top of the post to insure a good weld. In this way build up the post until the lead comes up to the top of the post builder. Then lift the flame straight up from the post. Allow the lead to set, and then remove the post builder, grasping it with a pair of gas or combination pliers and turn the post builder around to loosen it. Extending Plate Lugs It sometimes happens that a good plate is broken from a strap, thus shortening the lug. Before the plate may be used again, the lug must be extended to its original length. To do this, clean the surfaces of the lug carefully, lay the plate on a sheet of asbestos, and place an iron form having a slot of the correct width, length, and thickness, as shown in Figure 150. Use a medium hissing flame, and melt the upper edge of the lug, and then run in lead from the lead burning strip to fill the slot in the iron form. The plate may then be used again. [Fig. 150 Extending lug on plate] Making Temporary Charging Connections After a battery has been opened it is often desired to charge a battery without burning on the intercell connectors. Temporary connections may be made between cells by placing a short length of a burning lead strip from post to post and applying a flame for an instant to spot-weld the strip to the top of the post. MOULDING LEAD PARTS In using special moulds for casting inter-cell connectors, plate straps with posts, terminals, etc., follow the special instructions furnished by the manufacturers as to the manipulation of the special moulds made by them. Aside from the special instructions for the use of moulds, there are general rules for the melting of lead and handling it after it is melted, which must be observed if good castings are to be made. Raw Materials. In every battery repair shop a supply of old terminals, cell connectors, posts, and straps, will gradually accumulate. These should not be thrown away or sold as junk, but should be kept in a box or jar provided for that purpose. Old plates should not be saved, since the amount of lead in the grid is small and it is often covered with sulphate. The lugs connecting the plates to the straps may, however, be used. Before using the scrap lead as much dirt as possible should be brushed off, and all moisture must be dried off thoroughly. Scrap lead contains some antimony, which is metal used to give stiffness to the parts. Using miscellaneous scrap sometimes gives castings which do not contain the proper percentage of antimony. If there is too much antimony present, cracked castings will be the result. To remedy this condition, bars of pure lead should be purchased from some lead manufacturing company. Adding pure lead will reduce the percentage of antimony. Bars of pure antimony should also be kept oil hand in case the castings are too soft. Lead Melting Pots are standard articles which may be purchased from jobbers. A pot having a 25 pound capacity is suitable for small shops and for larger shops a 125-pound size is best. Before melting any lead in such pots, have them thoroughly free from dirt, grease, or moisture, not merely in order to get clean castings, but also to avoid melted lead being thrown out of the pot on account of the presence of moisture. Severe burns may be the result of carelessness in this respect. In starting with an empty melting pot, turn oil the heat before putting in any lead, and let the pot become thoroughly heated in order to drive off any moisture. With the pot thoroughly hot, drop in the lead, which must also be dry. When the metal has become soft enough to stir with a clean pine stick, skim off the dirt and dross which collects on top and continue heating the lead until it is slightly yellow oil top. Dirt and lead do not mix, and the dirt rises to the top of the metal where it may readily be skimmed off. With a paddle or ladle, drop in a cleaning compound of equal parts of powdered rosin, borax, and flower of sulphur. Use a teaspoonful of this compound for each ten pounds of metal, and be sure that the compound is absolutely dry. Stir the metal a little, and if it is at the proper temperature, there will be a flare, flash, or a little burning. A sort of tinfoil popcorn effect will be noticed oil top of the lead. Stir until this melts down. Have the ladle with which you dip up the melted lead quite dry. When dipping up some of the lead, skim back the dark skin which forms oil top of the lead and dip up the clean bright lead for pouring. In throwing additional lead into a pot which is partly filled with melted lead, be sure that the lead which is thrown in the pot is dry, or else hot lead may be spattered in your face. Have the moulds clean and dry. The parts with which the lead comes into contact should be dusted with a mould compound which fills in the rough spots in the metal so that the flow of lead will not be obstructed, and the lead will fill the mould quickly. Dip tip enough lead to fill the part of the mould you use. When you once start pouring do not, under any circumstance, stop pouring until the lead has completely filled the mould. Lead cools very quickly after it is poured into the mould, and if you stop pouring even for all instant, you will have a worthless casting. In a shop having an ordinary room temperature, it is generally unnecessary to heat the moulds before making up a number of castings. If it is found, however, that the first castings are defective due to the cold mould chilling the lead, the mould should be heated with a soft flame. After a few castings have been made, the mould will become hot enough so that there will be no danger of the castings becoming chilled. When the castings have cooled sufficiently to be removed, strike the mould a few blows with a wooden mallet or a rawhide hammer to loosen, the castings before opening the mould. The castings may then be removed with a screwdriver. Cracked castings indicate that the mould was opened before the castings had cooled sufficiently, or that there is too much antimony in the castings. The remedy is to let the castings cool for a longer time, or to add pure lead to the melting pot. HANDLING AND MIXING ACID The electrolyte used in the battery is made by mixing chemically pure concentrated Sulphuric Acid with chemically pure water. The concentrated acid, or "full strength" acid cannot be used, not only because it would destroy the plates, but also because water is needed for the chemical actions which take place as a cell charges and discharges. The water therefore serves, not only to dilute the acid, but also to make possible the chemical reactions of charge and discharge. The full strength acid has a specific gravity of 1.835, and is mixed with the water to obtain the lower specific gravity which is necessary in the battery. The simplest scheme is to use only 1.400 specific gravity acid. This acid is used in adjusting the specific gravity of a battery on charge in case the specific gravity fails to rise to a high enough value. It is also used in filling batteries that have been repaired. Acid is received from the manufacturer in ten gallon glass bottles enclosed in wooden boxes, these being called "carboys." Distilled water comes in similar bottles. When distilled in the shop, the water should be collected in bottles also, although smaller ones may be used. Neither the acid nor the water should ever be placed in any vessels but those made of lead, glass, porcelain, rubber, or glazed earthenware. Lead cups, tanks, and funnels may be used in handling electrolyte, but the electrolyte must not be put in containers made of any metal except lead. Lead is rather expensive for making such containers, and the glass bottles, porcelain, rubber, or glazed earthenware may be used. In mixing acid with water, pour the water in the bottle, pitcher or jar, and then add the acid to the water very slowly. Do not pour the acid in quickly, as the mixture will become very hot, and may throw spray in your face and eyes and cause severe burns. Never add the water to the acid, as this might cause an explosion and burn your face and eyes seriously. Stir the mixture thoroughly with a wooden paddle while adding the acid. A graduate, such as is used in photography, is very useful in measuring out the quantities of acid and water. The graduate may be obtained in any size up to 64 ounces, or two quarts. In using the graduate for measuring both acid and water, be sure to use the following table giving the parts of water by volume. Although the graduate is marked in ounces, it is for ounces of water only. If, for instance, the graduate were filled to the 8 ounce mark with acid, there would be more than eight ounces of acid in the graduate because the acid is heavier than the water. But if the proportions of acid and water are taken by volume, the graduate may be used. A convenient method in making up electrolyte, is to have a 16 ounce graduate for the acid, and a 32 or 64 ounce graduate for the water. In the larger graduate pour the water up to the correct mark. In the 16 ounce graduate, pour 1.400 acid up to the 10 ounce mark. Then add the acid directly to the water in the graduate, or else pour the water into a bottle or pitcher, and add the acid to that. For instance, if we have a 32 ounce graduate, and wish to make up some 1.280 acid, we fill this graduate with water up to the 5-1/2 ounce mark. We then fill the 16 ounce graduate with 1.400 acid up to the 10 ounce mark. Then we slowly pour the 1.400 acid into the graduate containing the water, giving us 1.280 acid. In a similar manner other specific gravities are obtained, using the same amount of 1.400 acid in each case, but varying the amount of water according to the figures given in the last column of the next to the last table. The following table shows the number of parts of distilled water to one part of 1.400 specific gravity electrolyte to prepare electrolyte of various specific gravities. The specific gravity of the mixture must be taken when the temperature of the mixture is 70° F. If its temperature varies more than 5 degrees above or below 70°F, make the corrections described on page 65 to find what the specific gravity would be if the temperature were 70° F. BY WEIGHT For 1.300 specific gravity use 5 ounces of distilled water for each pound of 1.400 electrolyte. For 1.280 specific gravity use 6-1/2 ounces of distilled water for each pound of 1.400 electrolyte. For 1.275 specific gravity use 6-3/4 ounces distilled water for each pound of 1.400 electrolyte. For 1.260 specific gravity use 7-1/2 ounces distilled water for each pound of 1.400 electrolyte. BY VOLUME For 1.300 specific gravity use 3-1/2 pints distilled water for each gallon of 1.400 electrolyte. For 1.280 specific gravity use 4-1/2 pints distilled water for each gallon of 1.400 electrolyte. For 1.275 specific gravity use 5 pints distilled water for each gallon of 1.400 electrolyte. For 1.260 specific gravity use 5-1/4 pints distilled water for each gallon of 1.400 electrolyte. In case you wish to use other measuring units than those given in the above table, this table may be written as follows, giving the number of parts distilled water to 10 parts of 1.400 specific gravity electrolyte: Specific Gravity Desired Parts by Weight Parts by Volume ---------------- ----------------------- --------------- 1.300 3 4-1/4 1.280 4 5-1/4 1.275 4-1/6 6 1.260 4-7/10 6-1/2 The next table gives the number of parts of distilled water to 10 parts of concentrated sulphuric acid (which has a specific gravity of 1.835) to prepare electrolyte of various specific gravities: Specific Gravity Desired Parts by Weight Parts by Volume ------------------------ --------------- --------------- 1.400 8-1/2 15-8/10 1.300 13-1/2 15-8/10 1.300 13-1/2 25 1.280 15 27 1.270 16 28 1.260 17 30 PUTTING NEW BATTERIES INTO SERVICE New batteries are received (a) fully charged and ready for service, (b) fully assembled with moistened plates and separators, but without electrolyte, (c) in a "knockdown" condition, with dry plates and without separators, (d) fully assembled with "bone dry" plates and rubber separators, and without electrolyte. Those received fully charged should be put on a car as soon as possible. Otherwise they will grow old on the shelf. Every month on the shelf is a month less of life. If the battery cannot be sold, put it into dry-storage. Batteries received in condition (b) should not be kept in stock for more than six months. Batteries received with dry plates and without separators or with rubber separators may be stored indefinitely without deteriorating. Batteries Shipped Fully Charged, or "Wet." All Makes. Unpack the battery, keeping the packing case right side up to avoid spilling electrolyte. Brush off all excelsior and dirt, and examine the battery carefully to see if it has been damaged during shipment. If any damage has been done, claim should be made against the express or railroad company. 1. Remove the vent caps from the cells and determine the height of the electrolyte. It should stand from three-eighths to one-half inch above the tops of the plates. The level may be determined with a glass tube, as shown in Fig. 30. If the electrolyte is below the tops of the plates, it has either been spilled, or else there is a leaky jar. If all cells have a low level of electrolyte, it is probable that the electrolyte has been spilled. 2. Next measure the specific gravity of the electrolyte of each cell with the hydrometer, and then add water to bring the electrolyte up to the correct level, if this is necessary. Should the temperature of the air be below freezing, charge the battery for an hour if water is added no matter what the specific gravity readings are. This will cause the water to mix thoroughly with the electrolyte. If the battery were not charged after water is added, the water, being lighter than the electrolyte, would remain on top and freeze. For this one hour charge, use the "starting" rate, as stamped on the nameplate. 3. If the specific gravity of the electrolyte reads below 1.250, charge the battery until the specific gravity reads between 1.280 and 1.300. For this charge use the normal bench charging rates. 4. After this charge place the battery on a clean, dry spot for twenty-four hours as an extra test for a leaky jar. If there is any dampness under the battery, or on the lower part of the battery case, a leaky jar is indicated. An inspection of the level of the electrolyte, which even though no dampness shows, will show the leaky jar. 5. Just before putting the battery on the car, make the high rate discharge test on it. See page 266. BATTERIES SHIPPED "DRY" Exide Batteries Storing. 1. Keep the battery in a dry, clean place, and keep the room temperature above 32 degrees, and below 110 degrees Fahrenheit. 2. Put the battery into service before the expiration of the time limit given on the tag attached to the battery. The process of putting the battery into service will require about five days. 3. If the battery has been allowed to stand beyond the time limit, open up one of the cells just before beginning the process necessary to put the battery into service. If the separators are found to be cracked, split, or warped, throw away all the separators from all the cells and put in new ones. If the separators are in good condition, reassemble the cell and put the battery into service. Putting Battery into Service. 1. Fill the cells with electrolyte of the correct specific gravity. To do this, remove the vent plugs and pour in the electrolyte until it rises to the bottom of the vent tubes. The correct specific gravities of the electrolyte to be used are as follows: (a) For Types DX, XC, XE, XX and XXV, use 1.360 electrolyte. In tropical countries use 1.260 electrolyte. (b) For Types LX, LXR, LXRE, LXRV, use 1.340 electrolyte. In tropical countries use 1.260 electrolyte. (c) For Types MHA and PHC, use 1.320 electrolyte. In tropical countries use 1.260 electrolyte. (d) For Types KXD and KZ, use 1.300 electrolyte. In tropical countries use 1.240 electrolyte. 2. After filling with the electrolyte, allow the battery to stand ten to fifteen hours before starting the initial charge. This gives the electrolyte time to cool. 3. No sooner than ten to fifteen hours after filling the battery with electrolyte, add water to bring the electrolyte up to the bottom of the vent tubes, if the level has fallen. Replace the vent caps and turn them to the right. Start charging at the rates shown in the following table. Continue charging at this rate for at least 96 hours (4 days). Table of Initial and Repair Charging Rates Type and Size of Cell Charging Rate, Amperes Minimum Ampere Hours --------------------- ---------------------- -------------------- KZ-3 1/2 50 LX-5, LXR-5, LXRE-5 1-1/2 145 KXD-5 2 190 XC-9, XX-9 2-1/2 240 DX-11, KXD-7, LXR-9, LXRE-9, XC-11, XE-11 3 290 DX-13, KXD-9, LXR-11, XC-13, XE-13, XX-13 4 385 LXR-13, LXRE-13, XC-15, XE-15, XX-15 4-1/2 430 KXD-11, XC-17, XE-17 5 480 LXRV-15, LXR-15, LXRE-15 5-1/2 525 LX-17, LXR-17, LXRE-17, XC-19, XE-19, XXV-19 6 575 MHA-11, PHC-13 6 575 XC-21, XE-21 6-1/2 625 XC-23 7 675 XC-25 7-1/2 720 4. Occasionally measure the temperature of the electrolyte. Do not allow the temperature to rise above 110° Fahrenheit (120° Fahrenheit in tropical countries). Should the temperature reach 110°, stop the charge long enough to allow the temperature to drop below 100°. 5. At the end of the charge, the specific gravity of the electrolyte should be between 1.280 and 1.300 (1.210 and 1.230 in tropical countries). If it is not between these limits adjust it by drawing off some of the electrolyte with the hydrometer and replacing with water if the specific gravity is too high, or with electrolyte of the same specific gravity used in filling the battery, if the specific gravity is too low. 6. Wipe off the top and sides of the battery case with a rag dampened with ammonia to neutralize any electrolyte which may have been spilled. 7. Just before putting the battery into service, give it a high rate discharge test. See page 266. Vesta Batteries 1. Remove vent caps from each cell and fill with electrolyte of 1.300 specific gravity. This electrolyte should not have a temperature greater than 75° Fahrenheit when added to the cells. 2. After the addition of this acid, the battery will begin to heat and it should be left standing from 12 to 24 hours or until it has cooled off. 3. Battery should then be put on charge at the finish charging rate stamped on the name plate. Continue charging at this rate for approximately 48 to 72 hours or until the gravity and voltage readings of each cell stop rising. 4. Care should be taken to see that the temperature of battery does not rise above 110° Fahrenheit. If this occurs., the charging rate should be cut down. 5. The acid in each cell will undoubtedly have to be equalized. 6. At the finish of this developing charge the gravity should read 1.280 in each cell. If below this, equalize by putting in 1.400 specific gravity acid, or if the contrary is the case and the acid is above 1.280 add sufficient distilled water until the gravity reads 1.280. 7. After the acid has been equalized and it has stopped rising in density the voltage of each cell while still on charge at the finishing rate should read at least 2.5 volts per cell or better. 8. The battery is then ready for service. Just before putting battery into service, make a high rate discharge test on it. See page 266. Philadelphia Diamond Grid Batteries 1. Remove the vent plugs and immediately fill the cells With electrolyte until the level is even with the bottom of the vent tube in the cover. Do not fill with electrolyte whose temperature is above 90° Fahrenheit. The specific gravity of the electrolyte to be used in starting batteries varies with the number of plates in each cell, the correct values being as follows: Charging Rates Fill batteries listed in Table No. 1 with 1.270 sp. gr. acid. TABLE--No. 1 No. of LL-LLR Plates & LH LM, LMR LT, LTR LS, LSR LG LT LSF ------ ------ ------- ------- ------- --- --- --- 9 2.0 2.5 2.0 2.5 3.0 11 2.5 3.0 2.5 3.5 4.0 13 3.0 3.5 3.0 4.0 2.5 15 3.5 4.0 3.5 4.5 5.5 17 4.0 5.0 4.0 5.5 6.0 19 4.5 5.5 4.5 6.0 Special Battery: 136 USA ... 6. 0 amps. TABLE NO.2 Fill batteries listed in Table No. 2 with 1.250 sp. gr. acid. No. LL-LLR LM LT LS S of Plates & LLH LMR LTR LSR SH ST LSF --------- ------ --- --- --- --- --- --- 5 1.0 1.0 2.0 1.5 7 1.5 1.5 1.5 2.0 3.0 2.0 1.5 9 4.0 11 5.0 Special Batteries: 330 AA .... 1.0 amps. 524 STD-H2 ................... 1.0 amps. 7 6 SPN ...................... 1.5 amps. The number of plates per cell is; indicated in the first numeral of the type name. For instance, 712 LLA-1 is a 7 plate LL. For all lighting batteries, types S and ST. use 1.210 electrolyte. 2. Allow the battery to stand for one or two hours. 3. Remove the seal from the top of the vent caps, and open by blowing through the cap. 4. Insert vent plugs in the vent tubes. 5. Put the battery on charge at the rate given in the table on page 228. To determine the rate to use, see type name given on the battery nameplate and find correct rate in the table. Keep the battery charging at this rate throughout the charge. 6. Continue the charge until the battery voltage and the specific gravity of the electrolyte stop rising, as shown by readings taken every four hours. From three and one-half to four days of continuous charging will be required to fully charge the battery. 7. Watch the temperature of the electrolyte, and do not allow it to rise above 110° Fahrenheit. If the temperature rises to 110° F., stop the charge and allow battery to cool. Extend the time of charging by the length of time required for the battery to cool. 8. After the specific gravity of the electrolyte stops rising, adjust the electrolyte to a specific gravity of 1.280 at a temperature of 70° Fahrenheit. If the temperature is not 70°, make temperature corrections as described on page 65. 9. The battery is now ready to be installed on the car. Just before installing the battery, make a high rate discharge test on it. Willard Bone-Dry Batteries A Willard Threaded Rubber insulated battery is shipped and carried in stock "bone-dry." It is filled with electrolyte and charged for the first time when being made ready for delivery. Threaded Rubber Insulated Batteries received bone-dry must be prepared for service, as follows: 1. Mix electrolyte to a density of 1.275. 2. Remove the vent plugs and fill to the top of the vent hole with 1.275 electrolyte. Be sure that the electrolyte is thoroughly mixed by stirring and that its temperature is not above 90 degrees Fahrenheit. 3. A portion of the solution will be absorbed by the plates and insulation because they have been standing dry without any liquid in the cells. The volume is thus decreased, necessitating the addition of electrolyte after first filling. Wait five minutes and then again fill to the top of the vent hole with 1.275 electrolyte. 4. The battery must now stand at least twelve hours and not more than twenty-four hours before charging. After it has been filled an increase in temperature of the battery solution will take place. This is caused by the action of the acid in the solution penetrating the plates mid reacting with the active material, but does no injury. Since the acid in the solution joins the active material in the plates the density of the solution becomes proportionately lower. This is to be expected and should cause no concern. In order that the entire plate volume of active material may be in chemical action during charge, the battery should stand before being placed on charge--until the solution has bad time to penetrate the entire thickness of the plates. This requires at least twelve hours, but not more than twenty-four hours. 5. Just before charging the battery, again fill with 1.275 electrolyte to 3/8 inch over the top of the separators. After this, do not add anything but distilled water to the battery solution. 6. The battery should then be put on charge at the finish rate until the gravity stops rising. At the end of this period the specific gravity should be between 1.280 and 1.300. It may take from 36 to 72 hours before this density is reached. Care should be taken not to prolong the charging unduly, for that may cause active material to fall out of the grids, thus injuring the plates beyond repair. 7. Because of the evaporation of water in the solution during the charging process, it is necessary to add distilled water from time to time in order to keep the solution above the tops of the separators. The temperature of the battery while on charge should never exceed 110 degrees Fahrenheit. If the temperature rises above this point the charging must be discontinued for a time or the rate decreased. If at any time during the initial charging the density rises above 1.300 some of the solution should immediately be drawn off with a syringe and distilled water added. This must be done as often as is necessary to keep the density below 1.300. If the specific gravity does not change after two successive readings and does not then read within the limits of 1.280 to 1.300 it should be adjusted to read correctly. If the reading is less than 1.280 it should be adjusted by drawing off as much solution as can be taken out with a syringe and electrolyte of 1.400 specific gravity added. The battery must then be placed on charge for at least four hours and another reading taken. If it is again found to be less than 1.280 this operation should be repeated as many times as necessary to bring the density up to 1.280. 9. The height of solution when taking the battery off charge should be 5/8 of an inch above the top of the separators. After the battery has been off charge long enough to permit the solution to cool to normal temperature, draw off the excess to a final height of 3/8 inch above separators. Replace the vent plugs and battery is ready for service. Unfilled Willard Wood Insulated Batteries Unfilled, wood-insulated batteries have not had an initial charge and require a treatment similar to batteries with threaded rubber insulation. When shipment is made in this manner, such batteries should be placed in service before the date indicated on the tag attached to the battery. To prepare such a battery for service: 1. Remove the vent plugs and fill each cell with 1.335 specific gravity electrolyte (one part of concentrated sulphuric acid by volume to two parts of distilled water by volume) to 3/8 inch above the tops of the separators. 2. Wait 5 minutes and then fill each cell again with 1.335 specific gravity electrolyte to 3/8 inch above the tops of the separators. 3. The battery must then stand from 10 to 15 hours before placing on charge. 4. After standing for this length of time, fill each cell again, if necessary, with 1.335 specific gravity electrolyte to bring the level of the electrolyte 3/8 inch above the tops of the separators before charging. 5. Place the battery on charge at the finish rate marked on the name plate until the gravity and cell voltage stop rising. This charging will require at least 48 hours. 6. If, after a charge of 48 hours or longer the specific gravity does not rise for two consecutive hours, the gravity should be between 1.280 and 1.300. If it is not between these limits, the specific gravity should be adjusted to these values at the end of the charge. 7. If, during the charge, the temperature exceeds 110 degrees Fahrenheit, the charge rate should be reduced so as to keep the temperature below 110 degrees Fahrenheit and the time of charging lengthened proportionately. Preparing Westinghouse Batteries for Service (These batteries are prepared for shipment in what is known as export condition.) 1. Remove vent plugs and discard soft rubber caps. 2. Fill all cells with 1.300 specific gravity sulphuric acid until top of connecting straps, as seen through vent holes are completely covered. Temperature of filling acid should never be above 90 degrees Fahrenheit. Note: The aim is to fill the cells with acid of such a Specific gravity that the electrolyte, at the end of charge, will need very little adjusting to bring it to the proper specific gravity. 1.300 specific gravity acid has been found to be approximately correct for this purpose. However, if after several batteries have been prepared for service using 1.300 specific gravity acid, considerable adjusting at the end of charge is necessary, it is permissible to use a slightly different specific gravity of filling acid, but the use of acid above 1.325 specific gravity or below 1,250 specific gravity is not recommended. 3. Allow batteries to stand after filling for from two to three hours before putting on charge. 4. Put on charge at finish charge rate shown on name plate of battery. Note: If temperature of electrolyte in battery reaches 100 degrees Fahrenheit (determined by inserting special thermometer through vent hole in cover), the charging rate should be immediately reduced, as continued charging at a temperature above 100 degrees Fahrenheit is injurious to both separators and plates. 5. Continue charging until all cells are gassing freely and individual cell voltage and specific gravity of electrolyte have shown no decided rise for a period of five hours. Note: The length of time required to completely charge a new battery depends largely upon the time the battery has been in stock, varying from twelve to twenty-four hours for a comparatively fresh battery to four or five days for a battery six months or more old. 6. Keep level of electrolyte above tops of separators at all times, while charging by adding distilled water to replace that lost by evaporation. 7. After battery is completely charged the specific gravity of electrolyte in all cells should be adjusted to 1.285 at 70 degrees Fahrenheit, and the level of electrolyte adjusted so that after battery is taken off charge the height of electrolyte stands 1/8 inch above tops of connecting straps. Note: Corrections for temperature if temperature of electrolyte is above or below 70 degrees Fahrenheit the correction is one point of gravity for each three degrees of temperature. See page 65. If specific gravity of electrolyte is above 1.285, a portion of the electrolyte should be removed and replaced with distilled water. If the specific gravity is below 1.285, a portion of electrolyte should be removed and replaced with 1.400 specific gravity sulphuric acid. Acid of higher gravity than 1.400 should never be put in batteries. Batteries should always be charged for several hours after adjusting gravity to insure proper mixing of the electrolyte and to see that the correct specific gravity of 1.285 has been obtained. 8. After first seven sections have been followed examine vent plugs to see that gas passage is Dot obstructed and screw back in place. Battery is now ready for service. The Prest-O-Lite Assembled Green Seal Battery This type of battery is made up of the same sort of plates as the old partly assembled green seal battery. The elements are, however, completely assembled will wood separators and sealed in the jars and box in the same manner as a wet battery to be put into immediate service; the cell connectors are burned in place. How to Store It. A room of ordinary humidity, one in which the air is never dryer for any reason than the average, should be used to store these batteries. They should be shielded from direct sunlight. Examine the vents-they should be securely inserted and remain so during the entire storage period. If these precautions are observed, this type battery may be stored for at least a year. To Prepare Battery for Use. 1. Prepare sufficient pure electrolyte of 1.300 specific gravity. If during the mixing considerable heat is evolved, allow electrolyte to cool down to 90 degrees Fahrenheit. Never pour electrolyte, that is warmer than 90 degrees Fahrenheit, into cells. 2. Remove the vents and lay them aside until the final charging operation has been completed. Within 15 minutes from the time the vents are removed fill all cells to the bottom of vent openings with the electrolyte prepared, as stated above. 3. Allow the electrolyte to remain in the cells, not less than one hour. At the end of this time, should the electrolyte level fall below the tops of the separators, add enough electrolyte to bring level at least one-half inch above separators. If the temperature in the cells does not rise above 100 degrees Fahrenheit, proceed immediately (before two hours have elapsed) with the initial charging operation. If the temperature remains above 100 degrees Fahrenheit, allow the battery to stand until the electrolyte cools down to 100 degrees Fahrenheit. Then proceed immediately with the charge. It is important that the acid does not stand in the cells for more than two hours, unless it is necessary to allow the acid to cool. 4. Initial Charging Operation. Place the battery on charge at the ampere rate given in the following table. The total initial charge must be for fifty-two hours, but at no time permit the electrolyte temperature to rise above 115 degrees Fahrenheit. If the temperature should reach 115 degrees Fahrenheit, take the battery off the line and allow the electrolyte to cool, but be sure that the total of fifty-two hours actual charging at the ampere rate specified is completed. Initial Charge---52 Hours Plates Type of per Cell Plate AHS WHN RHN SHC BHN JFN GM CLN KPN -------- --- --- --- --- --- --- --- --- --- 3 1.5 5 2 2 2.5 3 7 3 3 3.5 4 3 5 9 4 4 5 5 7 11 5 5 6 7 7.5 5 9 13 6 6 7 8 9 6 10.5 10.5 15 7 7 9 9.5 10.5 7 12 17 10 12 9 19 9 9 11 12 9 The nominal battery voltage and the number of plates per cell is indicated by the Prest-O-Lite type designations, i. e.: 613 RHN denotes 6 volts, 13 plates per cell or 127 SHC denotes 12 volts, 7 plates per cell. 5. The electrolyte density at the end of fifty-two hours charge should be near 1.290 specific gravity. A variation between 1.285 and 1.300 is permissible. If, after fifty hours of the initial charge, the electrolyte density of any of the cells is outside these limits, adjustment should be begun while still charging. For those cells in which the density is higher than 1.300 specific gravity replace some of the electrolyte with distilled water. In those cells where the density is lighter than 1.285 specific gravity replace some of the electrolyte with previously prepared electrolyte of 1.400 specific gravity. Wait until the cells have charged one hour before taking readings to determine the effect of adjustment, which, if not accomplished, should be attempted again as before. Practice Will enable the attendant to estimate the amount of electrolyte necessary to replace in order to accomplish the proper density desired-at the end of initial charge. 6. Following the completion of the fifty-two hour charge, if there is time to do so, it is good practice to put the battery through a development cycle, i. e., to discharge it at about the four-hour rate and then put it on the charging line again at the normal rate until a condition of full charge is again reached. The objects gained by this discharge are: (a) Further development of the plates. (b) Adjustment or stabilization of the electrolyte. (c) Checking the assembly by noting the failure of any cell or cells to act uniformly and satisfactorily during discharge. The four-hour discharge rate is, of course, like the normal rate of Initial Charge, dependent upon the size and number of plates per cell in any particular battery; the number of cells determines the voltage only and has nothing to do with the battery's charge or discharging rating. These four-hour discharge rates are as follows: Plates per Cell Type of Plate AHS WHN RHN SHC BHN JFN GM CLN KPN -------- --- --- --- --- --- --- -- --- --- 3 3 5 5 5 5.5 6.5 7 7.5 7.5 8 10 7.5 13.5 9 10 10 11 13 18 11 12.5 12.5 14 16 19 12.5 22.5 13 15 15 16.5 19.5 22.5 15 27 27 15 17.5 17.5 19 23 26 17.5 31.5 17 22 26 19 22.5 22.5 25 29 22.5 Immediately at the end of the four-hour discharge, put the battery on the line and charge it at the normal rate prescribed in the Initial Charge rate table until a state of complete charge, as noted by cell voltage and gravity is reached. This charging time should be about sixteen hours. Any adjustments of electrolyte found necessary at the end of this charging period in the same manner prescribed in paragraph No. 5, for such adjustments made just before the completion of the initial fifty-two hour charge. (TRANSCRIBER'S NOTE: No item number 7. in original publication.) 8. At the end of the fifty-two hour charge, or, if the Development discharge has been given, at the end of the Development Cycle Charge, replace the vent plugs, wash all exterior surfaces with clean water and dry quickly. The battery is then ready for service. INSTALLING A BATTERY ON A CAR A battery must be installed carefully on the car if it is to have any chance to give good service. Careless installation of a battery which is in good working order will invariably lead to trouble in a very short time. On the other hand, a properly installed battery is, nine times out of ten, a good working and long lived battery. After you have removed the old battery, scrape all rust and corrosion from the inside of the battery box or compartment in which the battery is placed. This can best be done with a putty knife and wire brush. If you find that electrolyte has been spilled in the box, pour a saturated solution of baking soda on the parts affected so as to neutralize the acid. Then wipe the inside of the box dry and paint it with a good acid proof paint. Next take out the hold down bolts. Clean them with a wire brush, and oil the threads on the bolt and in the nut to make them work easily. It is very important that this oiling be done, as the oil protects the bolts from corrosion, and to remove the nuts from a corroded bolt is an extremely difficult and aggravating piece of work, often resulting in the bolts being broken. Should such bolts become loose while the car is in use, it is hard to tighten them. Wooden strips found in the battery box should be thoroughly cleaned and scraped, and then painted with acid proof paint. When you lower the battery into its box, lower it all the way gently. Do not lower it within an inch or so of the bottom of the case and then drop it. This will result in broken jars and plate lugs. Turn the hold downs tight, but not so tight as to break the sealing compound at the ends of the battery, thereby causing electrolyte to leak out, and battery to become a "slopper". Cables and connectors should be scraped bright with a knife and brushed thoroughly with the wire brush to remove all corrosion. Old tape which has become acid soaked should be removed and the cable or wire underneath cleaned. Before applying new tape, take a small round bristle brush and paint Vaseline liberally over the exposed cable immediately back of the taper terminal. Then cover the Vaseline with tape, which Should be run well back from the terminal. The Vaseline prevents the corrosion of the cable and the tape holds the Vaseline in place. After the tape has been applied, paint it with acid proof paint. Cover the terminals of the battery with Vaseline. Cables must have enough slack to prevent strains from being put on the battery terminals. By following these directions, you will not only have a properly installed battery, which will have a good chance to give good service, but will have a neat looking job which is most pleasing to the eye of the car owner. Remove all dirt from the battery and cable terminals and thoroughly clean the surfaces which are to connect together, but do not scrape off the lead coating. Apply a heavy coating of pure Vaseline to these surfaces and tighten the connection perfectly, squeezing out the Vaseline. Then give the whole connection a heavy coating of Vaseline. This is very important in order to prevent connection trouble. If battery is installed in an enclosing box, be sure that none of the ventilating holes are clogged. STORING BATTERIES When a battery is not in active use on a car it should be put into storage. Storage is necessary: 1. When a car is to stand idle for a considerable period, such as is the case when it is held for future delivery. 2. When a car is laid up for the winter. 3. When batteries are kept in stock. Batteries may be stored "wet," i.e., completely assembled and filled with electrolyte, or "dry," i.e., in a dry disassembled condition, without electrolyte. In deciding whether a battery should be stored "wet" or "dry," two things are to be considered, i.e. the length of time the battery is to be in storage, and the condition of the battery. If a battery is to be out of commission for a year or more, it should be put into "dry" storage. If it is to be in storage for less than one year, it may be put into "wet" storage if it is in a good condition. If the condition of the battery is such that it will need to be dismantled soon for repairs, it should be put into "dry" storage, even though it is to be out of service for less than one year. Batteries in "dry" storage require no attention while they are in storage, but they must be dismantled before being put into storage and reassembled when put back into service. When a battery is brought in to be stored, note its general condition carefully. (a) Its General Appearance-condition of case, handles, terminals, sealing compound, and so on. (b) Height and specific gravity of the electrolyte in each cell. (c) Age of Battery. Question owner as to length of time he has had battery. Read date marks on battery if there are any, or determine age by the age code. See page 243. If a battery is less than a year old, is in good condition, and is to be stored for less than one year, it may be put into "wet" storage. If it is more than a year old, put it into dry storage, unless it is in first class shape and is to be stored for only several months. After making your general observations, clean the battery, add distilled water to bring the electrolyte up to the proper level, put the battery on charge and keep it on the line until it is fully charged. Watch for any abnormal condition during the charge, such as excessive temperature rise, failure of voltage to come up, failure of specific gravity to come up, and gassing before gravity becomes constant. If no abnormal conditions develop during the charge, put the battery on discharge at a rate which will cause the voltage to drop to 1.7 volts per cell in about four hours. Measure the cell voltages at regular intervals during the discharge test. If the voltage of any cell drops much more rapidly than that of the other cells, that cell is defective in some way, and should be opened for inspection. If the voltage of all cells drops to 1.7 in three hours or less, the battery should be put into dry storage. After completing the discharge test, recharge it fully, no matter whether it is to be put into wet or dry storage. If no trouble developed during the charge or discharge, the battery may be put into "wet" storage. If trouble did develop, the battery should be put into "dry" storage. If dry storage is found to be necessary the owner should be informed that the condition of his battery would cause it to deteriorate in wet storage and necessitate much more expensive repairs when put into use again than will be necessary in the thorough overhauling and rejuvenation of dry storage. He should be advised that dry storage involves dismantling, drying out elements and reassembling with the needed repairs and new separators in the Spring. Be sure that the customer understands this. If it is evident that repairs or new parts, involving costs additional to storage charges, will be necessary, tell him so. Do not leave room for a complaint about costs in the Spring. To avoid any misunderstanding, it is highly advisable to have the customer put his signature on a STORAGE AGREEMENT which states fully the terms under which the battery is accepted for storage. The storage cost may be figured on a monthly basis, or a price for the entire storage period may be agreed upon. The monthly rate should be the same as the regular price for a single battery recharge. If a flat rate is paid for the entire storage period, $2.00 to $3.00 is a fair price. "Wet" Storage 1. Store the batteries on a bench or shelf in a convenient location and large enough to allow a little air space around each battery. 2. Place each battery upon wooden strips in order to keep the bottom of the battery clear of the bench or shelf. 3. Apply Vaseline freely to the battery terminals, and to exposed copper wires in the battery cables if the cables are burned directly to the battery terminals. If the cables are not burned on, remove them from the battery. 4. If convenient, install the necessary wiring, switches, etc., so that batteries may be connected up and charged where they stand. Otherwise the batteries must be charged occasionally oil the charging bench. [Fig. 151 Batteries connected for trickle charge] 5. Batteries in wet storage may be charged by the Exide "Trickle" charge method, or may be given a bench charge at regular intervals. 6. Bench Charge Method.--Once every month, add distilled water to replace evaporation. Then give battery a bench charge. See page 198. Before putting battery into service repeat this process and just before putting the battery into service, make the high rate discharge test on it. See page 266. 7. Trickle Charge Method.--This consists of charging the batteries in storage continuously at a very low rate, which is so low that no gassing occurs, and still gives enough charge to maintain the batteries in good condition. In many cases the "Trickle" Charge method will be found more convenient than the bench charge method, and it has the advantage of keeping the batteries in condition for putting into service on short notice. It should, however, be used only where direct current lighting circuits are available. In the "Trickle" method, the batteries are first given a complete bench charge, and are then connected in series across a charging circuit with one or several incandescent lamps in series with the batteries to limit the current. In Fig. 151, an example of connections for a "Trickle" charge is given. The charging current for different sized batteries varies from 0.05 to 0.15 ampere. The following table gives the lamps required to give the desired current on 110 volt circuit. In each case, the lamps are connected in series with the batteries. The "2-25 watt, (lamps), in parallel" listed in the table are to be connected in parallel with each other and then in series with the batteries. The same is true of the "3-25 watt (lamps), in series" listed in the table. Series on 115 Volt Line Amp. Hours No. of Cells No. 115 Volt Capacity Amperes in Series Lamps Required 5 Amp. Rate Approximate on Line 115 Volt ----------- ----------- ------------ -------------- 50 or less 0.05 3 5-15 watt, in series 50 or less 0.05 30 2-15 watt, in series 50 or less 0.05 45 1-15 watt, in series 50-100 0.10 3 3-25 watt, in series 50-100 0.10 3 1-25 watt, in series 50-100 0.10 45 2-25 watt, in parallel 100 or over 0.15 3 2-25 watt, in series 100 or over 0.15 30 1-25 watt, in series 100 or over 0.15 45 3-25 watt, in parallel Every two months interrupt the trickle charge long enough to add water to bring the electrolyte up to the proper level. When this has been done, continue the trickle charge. Before putting the batteries into service, see that the electrolyte is up to the correct level, and that the specific gravity of the electrolyte is 1.280-1.300. If necessary, give a short charge on the charging bench to bring the specific gravity up to the correct value. Dry Storage 1. Give the battery a complete charge. Pour out the electrolyte, and separate the groups. If the negatives have bulged active material, press them in the plate press. In batteries such as the Prest-OLite in which it is difficult to remove the plates from the cover, the groups need not be separated unless the negatives have badly bulged active material. It may not be necessary to separate the groups even then, provided that the positives are not buckled to any noticeable extent. If only a very slight amount of buckling exists, the entire element may be pressed by putting thin boards between the plates in place of the separators. 2. Immerse the negatives in distilled water for ten to twelve hours. If positives and negatives cannot be separated, wash each complete element in a gentle stream of water. 3. Remove plates from water and allow them to drain thoroughly and dry. The negatives will heat up when exposed to the air, and when they do so they should be immersed in the water again to cool them. Repeat this as long as they tend to heat up. Then allow them to dry thoroughly. 4. Throw away the old separators. Rubber separators may be saved if in good condition. Clean the covers and terminals., wash out the jars, and turn the case up side down to drain out the water. Examine the box carefully. It is advisable to wash with a solution of baking soda, rinsing the water in order to neutralize as far as possible the action of acid remaining on the box. If this is not done, the acid may start decomposition of the box while in storage, in which case the owner of the battery may insist on its renewal before acceptance at the end of the storage period. 5. When, the plates are perfectly dry, nest the positives and negatives together, using dry cardboard instead of separators, and replace them in the jars in their proper positions. 6. Replace the covers and vent plugs, but, of course, do not use any sealing compound on them. 7. Tie the terminals and top connectors to the handle on the case with a wire. 8. Tag the battery with the owner's name and address, using the tag on which you made the sketch of the arrangement of the terminals and top connections. 9. Store the battery in a dry place, free from dust, until called for. 10. When the battery is to be put into service again, put in new separators, put the elements in the jars, seal the covers, and burn on the top connectors and terminals (if these are of the burned-on type). Fill the cells with electrolyte of about 1.310 specific gravity and allow the battery to stand for ten to twelve hours in order to cool. Then put the battery on charge at one-half the normal charging rate and charge until the specific gravity of the electrolyte stops rising and remains stationary for five hours. The total time required for this development charge will be about four days. Watch the temperature of the electrolyte carefully, and if it should rise to 110° Fahrenheit, stop the charge until it cools. 11. The specific gravity will fall during the first part of the charge, due to the new separators; at the end of the charge, the specific gravity should be 1.280-1.300. If it is not within these limits, adjust it by withdrawing some electrolyte with the hydrometer and adding water if the gravity is high, or 1.400 electrolyte if the gravity is low. 12. Clean the case thoroughly and give it a coat of asphaltum paint. 13. Just before putting the battery into service, give it a high rate discharge test. See page 266. DETERMINING AGE OF BATTERY Battery manufacturers use codes to indicate the age of their batteries. These codes consist of letters, figures, or combinations of letters and figures, which are stamped on the inter-cell connectors or on the nameplate. The codes may also be burned on the case. The codes of the leading makes of batteries follow. In addition to determining the age of a battery by means of the code, the owner should be questioned as to the time the battery was installed on his car. If the battery is the original one which came with the car, the dealer's or car manufacturer's records will help determine the battery's age. If a new battery has been installed to replace the one that came with the car, the battery distributor's records will help determine the age of the battery. Familiarity with the different makes and types of battery will also help in determining a battery's age. Manufacturers make improvements in the construction of their batteries from time to time, and by keeping up-to-date on battery constructions, it is often possible to approximate the age of a battery by such changes. If a battery was kept "dry" while in stock, its age should be figured from the time it was prepared for service and placed on the car, since batteries in dry storage do not deteriorate. Some batteries are shipped from the factory "wet," i.e., filled with electrolyte and fully charged and the age of such batteries should be figured from the time they were shipped from the factory, because deterioration begins as soon as a battery is filled with electrolyte. When batteries are "dry" no chemical action can take place, and the battery does not deteriorate, while in a "wet" battery, chemical action takes place which gradually causes a battery to deteriorate. Exide Age Code. Since October, 1917, the date of shipment of Exide batteries from the factory, or from Exide Deposts has been stamped on the top of the first inter-cell connector from the negative end of the batter instead of on the nameplate figures are used to indicate the dates, as follows: [Image: Exide and Philadelphia battery age code charts] All Philadelphia batteries shipped prior to April 1, 1920 and all batteries shipped from depot stock after this date carry double letter branding. The first battery is the factory date and the second letter in this code indicates latest month during which the guarantee may begin. Batteries sold direct from Philadelphia to all classes of customers after April 1, 1920, carry the single letter branding code, indicating month of manufacture. The letters used in the double letter age code are selected from the table given above, and the second letter is the important one, since it gives the latest date from which adjustment can be made. If a Philadelphia battery with a double letter age code comes in, therefore, the foregoing table should be consulted in determining the age of the battery. If a Philadelphia battery with a single letter age code comes in, the following table should be consulted in determining the age of the battery: [Image: Single Letter Philadelphia Batteries Age Code Chart] Prest-O-Lite Age Code. All Prest-O-Lite batteries carry a date letter stamped on the cell-connectors. This letter indicates the month and year in which the battery was manufactured. The letter is preceeded by a number which represents the factory at which the battery was built. Prest-O-Lite Factory Marks. Indianapolis--50 Cleveland--7 San Francisco--23 For example: "50-K" indicates that the battery was manufactured at Indianopolis in January, 1920. In addition to the above, each "Wet" Prest-O-Lite battery is branded in the side with a date, as "9-19," indicating October, 1919. This date is really sixty days ahead of the actual building date, to allow time for shipping, etc., before the guarentee starts. The branded "9-19" was actually built in August, 1919. Titan Age Code. The age of Titan batteries is indicated by a number stamped on one of the inter-cell connectors, this number indicating the month the battery was hipped from the factory. [Image: Age code charts for Titan batteries] [Image: Age code charts for U.S.L., and Vesta batteries] [Image: Age code charts for Westinghouse and Willard batteries] RENTAL BATTERIES Rental batteries are those which are put on a customer's car while his own is being repaired or recharged. They are usually rebuilt batteries turned in when a new battery is bought. They may also be made of the good parts of batteries which are junked. By carefully saving good parts, such as plates, jars, covers, and cases, a stock of parts will gradually be acquired from which rental batteries may be made. Rental batteries may also be bought from the battery manufacturers. A supply of rental batteries should, of course, be kept ready to go out at any time. The number of such batteries depends upon the size of the business. 25 batteries for each 1000 cars in the territory served is a good average. Do not have too many rental batteries of the same type. Many of them will be idle most of the time and thus will not bring in any money. Rentals should be made to fit those makes of cars of which there are the greatest number in the territory served by the repair shop. Sufficient parts should be kept on hand to make up other rentals on short notice. Terminals for Rental Batteries There are several combination terminals on the market which allow rental batteries equipped with them to be easily connected to several of the various types of cable terminals that are in use. Yet it is a universal experience for the average service station always to have calls for rental batteries with just the type of terminals which are not on hand. When the station has many batteries with the clamp type straight posts the call always seems to be for the taper plug type and vice versa. [Fig. 152 Best type of connection to be used whenever possible] Most of us will agree that the clamp type post terminal is the cause of much trouble. It is almost impossible to prevent corrosion at the positive post and many a car owner has found that this has been his trouble when his lights burn all right but the battery seemingly does not have power enough to turn over the engine and yet every cell tests 1.280. Service Station men should not scrape and clean up a corroded clamp type terminal and put it back on again, but should cut it off and put on either a taper plug or, preferably, a lead-plated copper terminal lug. Of course either of these terminal connections necessitates changing the battery terminals to correspond. For rental batteries it will be found that short cable terminals with lead-plated copper lugs at the end will enable a battery man to connect most any type of cable terminal on any car. It is true that such connections must be taped up, but the prompt service rendered more than offsets a little tape. Figures 152 to 158 illustrate how these connections can be made to the taper plug and clamp types which are used on most cars. [Fig. 153 Method of connecting rental battery with cable terminals to car with taper plug] [Fig. 154 Another method of connecting copper terminal lug to clamp terminal on car] [Fig. 155 Method of connecting rental batteries with cable terminals to cars with clamp type terminals] Fig. 155. Showing method of connecting rental batteries with cable terminals, to cars with clamp type terminals. In Fig. 155 the cable insulation is stripped for a space of an inch and the strands are equally divided with an awl. A bolt is passed through the opening and a washer and nut complete the connection. [Fig. 156 and Fig. 157 Two methods of connecting a clamp type terminal to taper plug terminals] Two methods of connecting a clamp type terminal to taper plug terminals. In Fig. 156 a taper plug is inserted and screwed tight. The projecting part of the plug has been turned down to fit the clamp type terminal which is clamped to it. In Fig. 157 a bolt is passed through and the clamp type terminal tightened to the plug type terminal with a washer and nut. [Fig. 158 Lead plated copper terminal lug] Fig. 158 shows a simple means of putting on a lead-plated copper terminal lug without solder. These lugs should be soldered on whenever possible, but it is often a difficult job to put one on in the confined space of some battery compartments. In such places, a quick and lasting job can be made with a band vise and a short piece of round iron. This latter is laid across the lug and the vise screwed up, making a crimp across the lug which firmly grips down upon the bared cable strands that have been inserted into the lug. New batteries sold to replace other batteries should be installed with cable connections, as illustrated in Figure 152. This method of connecting a battery is superior to any other method and will never cause trouble. It will usually be found that the old taper plugs or clamp terminals that have been in use have started to corrode and that a new battery works increasingly at a disadvantage from the day it is installed until the corrosion becomes so great that the car cannot be started and then the customer kicks about his new battery. The best connection possible will pay handsome dividends to all concerned, in the end. Marking Rental Batteries. Rental batteries should be marked in a mariner which enables them to be recognized quickly. Painting the cases a red color is a good way. The service station's name should appear somewhere on the battery. A good plan is to have a lead tag, which is attached to the handle at the negative end of the battery, or is tacked to the case. The name may also be painted on the case. Each battery should be given a number which should preferably be painted in large white figures on the end or side of each case. The number may also be stamped on a lead tag tied to the handle at the negative end. A service station which sells a certain make of battery should not use cases of some other make if the name of the other make appears on the case. Such names may give a wrong impression to the customer, which will not be fair either to the service station or to the manufacturer whose name appears on the case. If the service station sells, another make of battery, the customer may get the impression that the service station man does not have enough confidence in the make which he sells, and must use some other make for his rentals. If the rental battery does not give good service, the customer will get the impression that the manufacturer whose name appears on the case does not turn out good batteries, when as a matter of fact, the plates, covers, jars, and other parts used in the rental battery may not have been made by this manufacturer. Some battery men would, perhaps, consider the failure of a rental battery as an opportunity to "knock" the manufacturer whose name appears on the case. Such an action may have the desired effect on a very few customers, but the great majority of men have no use for any one who "knocks" a competitor's products. Keeping a Record of Rental Batteries. A careful record should be kept of all rental batteries. The more carefully such a record is kept, the less confusion there will be in knowing just where every rental battery is. A special rack for rental batteries, such as those shown in Figures 88 and 89 should be provided, and all rental batteries which are in the shop should be kept there, except when they are on charge or are being overhauled. Have them fully charged and ready to go out immediately, without keeping a customer waiting around, when he is in a hurry to go somewhere else. General Rental Policy. No service station should make a practice of installing rental batteries on any car unless the owner leaves his own battery to be repaired or recharged. The purpose of having a stock of rental batteries is to enable customers to have the use of their cars while their own batteries are being repaired by the battery man who furnishes the rental battery and not to furnish batteries to car owners who may be taking their batteries to some other station to be repaired. It is, of course, a good thing to be generous and accommodating, but every battery repairman should think of his own business first, before he helps build up the business of a competitor. The customer must have some inducement to bring in your rental battery and get his own. A rental charge of 25 cents-per day serves as a reminder to most customers. However, some customers are forgetful and the battery man must telephone or write to any owner who fails to call for his battery. If, due to failure to keep after the owner, a rental battery is out for several weeks, there is likely to be an argument when the rental bill is presented to the owner. If the delay in calling in a rental battery is due to failure to repair the customer's battery, the rental charge should be reduced. A rental battery should not be put in place of a battery which is almost ready for the junk pile. The thing to do is to sell the customer a new battery. Repairs on an almost worn out battery are expensive and the results may not be satisfactory. RADIO BATTERIES The wide-awake battery man will not overlook the new and rapidly growing field which has been opened for him by the installation of hundreds of thousands of radio-phone receiving sets in all parts of the country. The so-called radio "craze" has affected every state, and every battery repairman can increase his income to a considerable extent by selling, charging, and repairing radio storage batteries. The remarkable growth of the radio-phone has, of course, been due to the radio broadcasting stations which have been established in all parts of the country, and from which concerts, speeches, market reports, baseball reports, news reports, children's stories and religious services are sent out. These broadcasting stations have sending ranges as high as 1,000 miles. The fact that a service station is not located near a broadcasting station is therefore no reason why it should not have its share of the radio battery business, because the broadcasting stations are scattered all over the United States, and receiving sets may be made powerful enough to "pick up" the waves from at least one of the broadcasting stations. Radio receiving sets may be divided into two general classes, the "Crystal" sets and the "Bulb" sets. "Crystal" sets use crystals of galena (lead sulphide), silicon (a crystalline form of silicon, one of the chemical elements), or carborundum (carbide of silicon) to "detect" or, in other words, to rectify the incoming radio waves so that they may be translated into sound by the telephone receivers. Receiving sets using these crystals do not use a battery, but these sets are not very sensitive, and cannot "pick up" weak waves. This means that crystal receiving sets must be used near the broadcasting stations, before the waves have been weakened by traveling any considerable distance. As a general rule, the radio-listener's first receiving set uses a crystal detector. Very often it is difficult to obtain good results with such a set, and a more elaborate set is obtained. Moreover, even if a crystal set does give good results, the owner of such a set soon hears of friends who are able to hear concerts sent out from distance stations. This gives him the desire to be able to hear such stations also and he then buys a receiving set which uses the "audion-bulb" for detecting, or rectifying the incoming waves. The audion-bulb resembles an ordinary incandescent lamp. It contains three elements: 1. In the center of the bulb is a short tungsten filament, the ends of which are brought out to two terminals in the base of the bulb. This filament must be heated to incandescence, and a storage battery is required for this purpose, because it is necessary to have a very steady current in order to obtain clear sounds in the receiver. Lately plans have been suggested for using a direct current lighting line, and even an alternating current lighting line for heating the filament, but at present such plans have not been perfected, and the battery will undoubtedly continue to be used with the majority of sets. 2. Surrounding the filament but not touching it is a helix of wire, only one end of which is brought out to a terminal in the base of the bulb. This helix is called the "grid." In some bulbs the grid is not made in the form of a helix, but is made of two flat gridlike structures, one on each side of the filament. 3. Surrounding the "grid" is the "plate" which is sometimes in the shape of a hollow metallic cylinder. Some plates are not round, but may be oval, or they may be two flat plates joined together at some point, and one placed on either side of the grid. The plate has one terminal in the base of the bulb. [Fig. 159 Illustrating the principle of the Audion Bulb] The action of an audion-bulb is quite complex, but a simpler explanation, though one which may not be exactly correct from a purely technical point of view, is as follows, referring to Figure 159: The "A" battery heats the filament, causing a stream of electrically charged particles to flow out from the filament in all directions. These electrons act as a conductor, and close the circuit which consists of the plate, the "B" battery, and the telephone receivers, one end of this circuit being connected to one side of the filament circuit. Current then flows from the positive terminal of the "B" battery to the plate, then to the filament by means of the stream of electrons emitted by the filament, along one side of the filament, through the wire connected to the positive terminal of the "A" battery to the telephone receivers, through the receivers to the negative terminal of the "B" battery. As long as the filament remains lighted a steady current flows through the above circuit. The "grid" is connected to the aerial wire to intercept the radio waves. These waves produce varying electrical charges on the grid. Since the stream of charged particles emitted by the filament must pass through the grid to reach the plate, the charges which the radio waves produce on the grid strengthen or weaken the stream of electrons emitted by the filament, and thus vary the current flowing in the telephone receiver circuit. The changes in this current cause the receiver diaphragm to vibrate, the vibrations causing sounds to be heard. Since the variation in the telephone receiver circuit is caused by electrical charges produced by the radio waves, and since the radio waves change according to the sounds made at the transmitting station, the variations in the telephone receiver current produces the same sounds that are sent out at the transmitting station. In this way concerts, speeches, etc., are reproduced in the receivers. The modern radio receiving set includes various devices, such as variable condensers, variocouplers, loose-couplers, variometers, the purpose of which is to "tune" or adjust the receiving set to be capable of receiving the radio waves. An explanation of such devices is not within the scope of this book, but there are numerous reasonably priced books and pamphlets on the market which describes in a simple manner all the component parts of a radio-receiving set. From the foregoing remarks it is seen that a six-volt storage battery is required with each receiving set which uses the audionbulb type detector. The filament current of an audion-bulb averages about one ampere. If additional bulbs are used to obtain louder sounds, each such bulb also draws one ampere from the storage battery. The standard audion-bulb receiving set does not use more than three bulbs, and hence the maximum current drawn from the battery does not exceed three amperes. The automobile battery manufacturers have built special radio batteries which have thick plates and thick separators to give longer life. The thick plates are much stronger and more durable than the thin plates used in starting and lighting work, but do not have the heavy current capacity that the starting and lighting battery plates have. A high current capacity is, of course, not necessary for radio work, and hence thick plates are used. Batteries used for radio work do not operate under the severe conditions which exist on automobiles, and trouble is much less likely to develop. However, the owner of the radio set rarely has any means of keeping his battery charged, and his battery gradually discharges and must then be recharged. It is in the sale of batteries for radio work and in the recharging of them that the battery man can "cash-in" on the radio phone "craze." This business rightfully belongs to the automobile battery man and he should go after it as hard as he can. A little advertising by the service station man, stating that he sells radio batteries, and also recharges them should bring in: very profitable business. The battery man who calls for and delivers the radio batteries which need recharging and leaves rental batteries in their place so that there is no interruption in the reception of the evening concerts is the one who will get the business. As already stated, radio storage batteries have thick plates and thick separators. Perforated rubber sheets are also used in addition to the separators. Large sediment spaces are also generally provided to allow a considerable amount of sediment to accumulate without causing short-circuits. The cases are made of wood or hard rubber. Since radio batteries are used in homes and are, therefore, used with handsomely finished cabinets containing the radio apparatus, the manufacturers give the cases of some of their radio batteries a pleasing varnished or mahogany finish. Before returning radio batteries which have been recharged, the entire batteries should be cleaned and the cases polished. Returning radio batteries in a dirty condition, when they were received clean, and polished, will drive the radio recharging business to some other service station. VESTA RADIO BATTERIES The Vesta Battery Corporation manufacturers three special types of "A" batteries for radio work, as follows: 1. The 6EA battery, made in capacities of 60, 80, and 100 ampere hours. Fig. 160. 2. The V6EA7 battery, having a capacity of 80 ampere hours. Fig. 161. 3. The R6EA battery, having a capacity of 100 ampere hours. Fig. 162. [Fig. 160, 161, 162, 163 Various Vesta Radio batteries] Vesta Radio Batteries. Fig. 160 shows the 6EA Series, "A" Battery. Fig. 161 shows the V6EA Series, "A" Battery. Fig. 162 shows the R6EA (Rubber Case) Series, "A" Battery. Fig. 163 shows the "B" Battery. These batteries have 5, 7, 9 plates per cell, respectively. The plates are each 5 inches high, 5 7/8 inches wide, and 5/32 inches thick. The cases for these batteries are furnished in three designs--plain black boxes (all sizes), finished maple boxes (7 plate size only), and hard rubber boxes (9 plate size only). These Vesta batteries are the "A" batteries used for heating the filaments of the audion bulbs. The Vesta Radio "B" battery, Fig. 163, is a 12 cell, 24 volt battery, with a 22 and a 20 volt tap. EXIDE RADIO BATTERIES [Fig. 164 Exide Radio "A" battery] The Exide Radio "A" battery, Fig. 164, is made in four sizes, the capacities ranging from 20 to 120 ampere-hours. The design and construction of these batteries are similar to the Exide starting batteries. The over-all height of these batteries is approximately 95/8 inches, the width 7-5/16 inches, while the length varies with the number of the plates. Type Cat. No. Length Weight Capacity -------- -------- ------ ------ -------- 3-LXL-3 13735 4-9/16 15-1/2 lbs. 20 amp. hrs. 3-LXL-5 13736 5-11/16 24-1/2 lbs. 40 amp. hrs. 3-LXL-9 13737 9-1/16 42-1/2 lbs. 80 amp. hrs. 3-LXL-13 13750 12-7/16 59-1/2 lbs. 120 amp. hrs. WILLARD RADIO BATTERIES The Willard Storage Battery Co. manufactures both "A" and "B" storage batteries. The Willard "A" battery, Fig. 165, is an all-rubber battery. The case is a rubber "Monobloc" construction, that is, the entire case is pressed into shape at one time. There are no separate jars for the cells, there being rubber partitions which form integral parts of the case. The case is, therefore, really a solid, one piece, three compartment jar. The ribs at the bottoms of the compartments are parts of the one-piece block, and are higher than those found in the usual starting and lighting battery. Embedded in each side wall of the case is a bronze button which holds the handle in place. Soft rubber gaskets of pure gum rubber surround the post to make an acid proof seal to prevent electrolyte from seeping from the cells. The separators are the standard Willard "Threaded Rubber" separators. [Fig. 165, 166, and 167 Various Willard Radio Batteries] Willard Radio Batteries. Fig. 165 shows the All-Rubber "A" Battery. Fig. 166 shows the complete "B" Battery. Fig. 167 shows one cell of the "B" Battery. The Willard "A" battery comes in five sizes, type WRR97 (20 ampere hours capacity), type WRRO (50 ampere hours capacity), type WRR1 (89 ampere hours capacity), type WRR2 (100 ampere hours capacity), and type WRR3 (125 ampere hours capacity). The Willard "B" storage battery, type CBR124, Figs. 166 and 167, is a twelve cell battery, each cell consisting of a round glass container having one negative and one positive plate insulated from each other by a small "Threaded Rubber" separator. The plates and separators rest on a hard rubber "bottom rest" which consists of a short length of hard rubber tube, so formed as to support the plates and separators and at the same time hold them together. The cells are assembled in a case which has a separate compartment for each cell. As seen from Fig, 166, the upper parts of the cells project above the top of the case, which simplifies inspection. WESTINGHOUSE RADIO BATTERIES [Fig. 168 Westinghouse Radio "A" battery, Type HR] [Fig. 169 Westinghouse Radio "B" battery, Type L, and Fig. 170 Westinghouse Radio "B" battery, Type M] The Westinghouse Union Battery Co. manufactures both "A" and "B" storage batteries. Their "ER" type, Fig. 168, is the "A" battery, and their "L" and "M" types, Figs. 169 and 170, are the "B" batteries. The HR battery has 3/16 inch thick plates, high rests to provide ample mud and acid space, and thick separators. Rubber sheets are placed on both sides of the positive plates. Rubber covered cables are moulded into the terminals to minimize corrosion at the positive terminal. The "HR" batteries are made in six and eight volt sizes, with 3 plates per cell, 5 plates per cell, 9 plates per cell, and 13 plates per cell. The Westinghouse Radio "B" batteries are made in two sizes. Type 22-M-2, Fig. 170, has a capacity of 1.2 ampere hours at 0.04 ampere. It is designed to operate a receiving set having one detector and two amplifier bulbs for three to five weeks between charges. The type 22-L-2 battery, Fig. 169, has a capacity of 4.5 ampere hours at 0.25 ampere. Part No. Type Volts Amp. Hours at 3 Amps. Weight Intermittent Rate -------- ---- ----- --------------------- ------ 100110 6-HR-5 6 54 A.H. 30 Lbs. 100111 6-HR-9 6 108 A.H. 46 Lbs. 100112 6-HR-13 6 162 A.H. 65 Lbs. 100135 8-HR-5 8 54 A.H. 40 Lbs. 100136 8-HR-9 8 108 A.H. 60 Lbs. 100137 8-HR-13 8 162 A.H. 87 Lbs. 100145 6-HR-3 6 27 A.H. 20 Lbs. Part No. Type Volts Capacity Weight ------- ------ ----- -------- ------ 100148 22-M-2 22 1.2 A.H. at .04 Amps. 6-1/4 Lbs. 100140 2-L-2 22 1.2 A.H. at 25 Amps. 19-3/4 Lbs. PHILADELPHIA RADIO BATTERIES [Fig. 171 Philadelphia Radio "A" battery] The Philadelphia Storage Battery Co. makes both "A" and "B" Radio batteries. The "A" battery, Fig. 171, uses the standard diamond-grid plates, and the "Philco Slotted Retainer" used in Philadelphia starting batteries. The cases of the "A" batteries are made of hardwood, finished in an ebonite black. Soft rubber insulating feet on the bottom of the case prevent scratching any table or varnished floor on which the battery may be set. The instructions for preparing the Philadelphia "A" battery for service are similar to those given for the starting and lighting batteries, given on page 228. For the initial filling, 1.220 electrolyte is used, and the battery charged at the following rates: Initial and Recharge Charging Rate ---------------------------------- Type Initial Rate Recharge Rate ---- ------------ ------------- 56LAR 1.0 2 56RAR 2.0 3 76RAR 3.0 4.5 96RAR 4.0 6 116RAR 5.6 7.5 136RAR 6.0 9 The final gravity of the electrolyte should be 1.250. However, if the owner insists on getting maximum capacity, the battery may be filled with 1.250 electrolyte and balanced to 1.290 at the end of the charge. [Fig. 172 Philadelphia Radio "B" battery] The Philadelphia Radio "B" battery, type 224-RB, Fig. 172, has 12 cells contained in a one-piece rubber case. It is shipped dry, and requires no initial charge. To prepare it for service, the soft rubber vent caps are removed and 25 c. c. of 1.250 electrolyte poured into each cell. U. S. L. RADIO BATTERY [Fig. 173 U.S.L. Radio "A" battery] The U. S. L. Radio "A" battery, Fig. 173, uses 1/4 inch positives, with 3/16 inch intermediate and 1/8 inch outside negatives. Port Orford cedar separators are used which are four times as thick as the usual starting battery separator. The case is made of hardwood, and is varnished to match cabinet work. The electrolyte has a specific gravity of 1.220. The heavy plates and separators and the low gravity of the electrolyte are designed to give long life. Ampere Ampere Hour Plates Hour Capacity per Capacity (or intermittent Type Cell @ 3 Amperes use) Dimensions Weight ---- ---- ----------- ---------------- ---------- ------ DXA-303-X 3 12 20 5-3/16 x 18 7-1/4 x 9-1/4 DXA-305-X 5 40 60 9-1/8 x 7-1/4 39 x 9-1/4 DXA-307-X 7 70 85 11-3/4 x 7-7/16 48 x 9-1/4 DXA-309-X 9 98 115 14-3/8 x 7-7/16 59 x 9-1/4 PREST-O-LITE RADIO BATTERIES The Prest-O-Lite Co. makes two lines of Radio "A" Batteries. First, an inexpensive battery, Fig. 174, and a deluxe battery, Fig. 175, which has a better finish and appearance. Both types have a mahogany finished case with rubber feet to prevent damaging furniture. A bail handle simplifies the carrying of the battery. Capacities range from 47 ampere-hours to 127 ampere-hours at a one ampere discharge rate. [Fig. 174 & 175 Presto-O-Lite Radio "A" battery] Table of Prest-O-Lite Radio Batteries ------------------------------------- Hours Discharge at Rate of: Type 1 Amp. 2 Amps. 3 Amps. 5 Amps. 10 Amps. ------- ------ ------- ------- ------- -------- 67 WHNR 47.5 21.7 13.6 7.5 3.0 69 WHNR 66 30 18.9 10.5 4.5 611 WHNR 82.8 38.5 24.3 13.5 6.0 67 KPNR 95 44.2 27.8 15.0 6.5 69 KPNR 127 61.5 38.5 21.5 9.5 UNIVERSAL RADIO BATTERIES [Fig. 176 Universal Type WR, Radio "A" battery] The Universal Battery Co. manufacture three types of Radio "A" storage batteries. Type WR, Fig. 176, has three sealed hard rubber jars assembled in a hardwood case which is stained and finished in mahogany. The separators are made of Port Orford cedar and are 1/8 inch thick, about twice the thickness of the separator used in starting and lighting batteries. The plates also are much thicker than the standard starting and lighting battery plate. The type WR battery comes in three sizes. Types WR-5, WR-7, and WR-9, having capacities of 60, 85, and 105 ampere hours, respectively, at a 3 ampere rate. The Universal type RR radio "A" battery, Fig. 177, is assembled in a hard rubber combination case, which is a solid piece of rubber divided into three compartments. This gives a compact, acid proof case. This battery also comes in three sizes, types RR-5, RR-7, and RR-9, having capacities of 60, 85 and 105 ampere hours, respectively, at a three ampere discharge rate. [Fig. 177 Universal Type RR, Radio "A" battery] [Fig. 178 Universal Type GR, Radio "A" battery] The Universal type GR radio "A" battery, Fig. 178, is assembled in three sealed glass jars which are placed in a mahogany finished wooden crate. This construction makes the cell interiors visible, enabling the owner to detect troubles and to watch the action of the cells on charge and discharge. The GR battery comes in two sizes, GR-5 and GR-Jr., having respective capacities of 60 and 16 ampere hours at a 3 ampere discharge rate. "DRY" STORAGE BATTERIES During the past year or two, so-called "dry" starting and lighting storage batteries have appeared on the market. This class includes batteries having "dry," "semi-dry," and "jelly" electrolytes. The claims made for these batteries are that there is nothing to evaporate and that the periodical addition of water is therefore unnecessary, that spilling and slopping of electrolyte is impossible, and that injurious sulphation does not take place. The "dry" storage battery is not a new idea, for as much as thirty-five years ago, the Oerlikon Company of Switzerland manufactured "dry" electrolyte storage batteries in commercial quantities. These batteries were for a long time a distinct success for work requiring only low rates of discharge. For high rates of discharge the lack of diffusion, due to the absence of a liquid electrolyte, reduces the capacity. The lack of diffusion will cause a rapid drop in voltage when cranking the engine! and a slow recovery after the engine begins to run under its own power. The manufacturers of the "dry" storage batteries, of course, claim that their batteries are more efficient and satisfactory than the standard "wet" battery, but it has been impossible to get sufficient data from the manufacturers to go into detail on the subject. Several of the largest of "wet" battery manufacturers formerly made "dry" storage batteries for lighting and ignition service, but when starting motors came into use, discarded the "dry" batteries in favor of the present "wet" storage batteries. DISCHARGE TESTS Discharge tests may be divided into four general classes: (a) Brief High Rate Discharge Tests to determine condition of battery. These tests are made for 15 seconds at a high rate. (b) Lighting Ability Discharge Tests. (c) Starting Ability Discharge Tests. (d) "Cycling" Discharge Tests. The 15 Seconds High Rate Discharge Test The 1.5 seconds high rate discharge test is a valuable aid in determining the condition of a battery, particularly where the hydrometer readings give false indications, such as is the case when electrolyte or acid is added to a cell instead of water to replace evaporation. Only two or three percent of the battery capacity is consumed by the test, and it is not usually necessary to recharge the battery after making the test. The test must be made in conjunction with hydrometer readings, as otherwise it might give false indications itself. Both incoming and outgoing batteries may be tested, and the method of testing depends upon whether the battery is coming in for repairs, or is going out after having been charged, repaired, or worked on in any way. In either case, the test consists of discharging the battery at a high rate for a short time, and taking voltage readings and making observations while the battery is discharging. [Fig. 179 Making a 20 seconds high rate discharge test] Rates of Discharge. It is not necessary to have any definitely fixed discharge rate. The rate should merely be high enough to reveal any improperly burned joints, short-circuited cells, or cells low in capacity for any reason. The discharge tester is suitable for all batteries used on cars and trucks. For an Incoming Battery. Take a hydrometer reading of each cell. If the readings are all below 1.200 and are within 50 points of each other, most likely all the battery needs is a bench charge, with a possible adjustment of the gravity of the electrolyte at the end of the charge. The discharge test should in this case be made after the battery has been fully charged. If the gravity readings are all above 1.200, or if the reading of one cell differs from the others by 50 points or more, make the discharge test, as shown in Fig. 179. After fifteen seconds, read the voltage of each cell. If the cells are uniformly low in voltage; that is, below 1.5 volts per cell, the battery needs recharging. If the voltage readings of the cells differ by 0.1.0 volt or more and the battery is fairly well charged, there is something wrong in the cell having the low reading, and the battery should be opened and examined. With a discharged battery the difference in cell voltage will be greater, depending on the extent of the discharge, and only experience can guide in drawing correct conclusions. A short-circuited cell will give a very low voltage reading. Remember that the actual voltage reading is not as important in indicating a defective cell as the difference between the voltage readings of the cells. A cell which gives a voltage which is 0.1 volt or more less than the others is generally defective. For Outgoing New, Charged, or Repaired Batteries. Just before putting the battery into service, make the test as a check on the internal condition of the battery, particularly if the battery has been repaired or has stood for sometime since being charged. (It is assumed that the battery has been charged and the gravity of the electrolyte properly adjusted when the test is made.) The battery should not show more than 0.10 volt difference between any two cells at the end of 15 seconds, and no cell should show a voltage less than 1.75 volts, and the voltage should remain fairly constant during the test. If every cell reads below 1.75 volts, the battery has not been completely charged. If one cell is more than 0.10 volt lower than the others, or if its voltage falls off rapidly, that cell still needs repairs, or is insufficiently charged, or else the top connectors are not burned on properly. Top connectors which heat up during the test are not burned on properly. Lighting Ability Discharge Tests These are tests continuing for 5 hours to a final voltage of 1.7 per cell. These tests are not of as great an interest as the Starting Ability Tests, description of which follows: Starting Ability Discharge Tests The Society of Automotive Engineers recommends two ratings for starting and lighting batteries: "Batteries for combined lighting and starting service shall have two ratings. The first shall indicate the lighting ability and be the capacity in ampere-hours of the battery when discharged continuously at the 5 hour rate to a final voltage of not less than 1.7 per cell, the temperature of the battery beginning such a discharge being 80 deg. Fahr. The second rating shall indicate the starting ability and shall be the capacity in ampere-hours when the battery is discharged continuously at the 20 minute rate to a final voltage of not less than 1.50 per cell, the temperature of the battery beginning such discharge being 80 deg. Fahr." The capacity in ampere-hours given by manufacturers is for a continuous discharge for 5 hours. In the battery shop, however, the "starting-ability" discharge test is the test which should be made, though the conditions of the test are changed somewhat. To make this test, the battery should be fully charged. Connect a rheostat to the battery terminals and adjust the rheostat to draw about 100 amperes from an 11 plate battery, 120 amperes from a 13 plate battery, 135 amperes from a 15 plate battery, 155 amperes from a 17 plate battery, 170 amperes from a 19 plate battery and so on. Continue the discharge for 20 minutes, keeping the discharge current constant, and taking voltage readings of each cell at the start, and at the end of 5, 10, 15, and 20 minutes. At the end of 20 minutes, if the battery is in good condition, the voltage of each cell should not be less than 1.5, and the temperature of the electrolyte in any cell should not exceed 95 degrees Fahrenheit, provided that the temperature at the start was about 80 degrees. The cell voltages should drop slowly during the test. If the voltage begins to drop rapidly during the test, as shown by the current falling off so rapidly that it is difficult to keep it at 100 amperes, measure the cell voltages quickly to see which cells are dropping rapidly. An example of a 100 ampere test on a good rebuilt cell with eleven plates is as follows: Voltage immediately after start of discharge, 1.88. After 5 minutes, 1.86 volts. After 10 minutes, 1.80 volts. After 15 minutes, 1.72 volts. After 20 minutes, 1.5 volts. If the voltage of a cell begins to fall off rapidly before the twenty minutes are up, but not before 15 minutes, the cell needs "cycling" (charging and discharging) to bring it up to capacity. If the voltage drops rapidly before the end of 15 minutes, the plates are low in capacity, due to age, or some defect. It is not safe to expect very good service from a cell which will not stand up for 20 minutes before de voltage begins to drop rapidly. If the rapid voltage drop begins very much before 20 minutes, it is very doubtful whether the battery will give good service. Comparisons of the results of tests with the service which the battery gives after installed on the car will soon enable the repairman to tell from the results of the tests just what to expect from any battery. The "starting-ability" test should be made on all batteries which have been rebuilt whenever there is time to do so and on all batteries about which there is any doubt as to what service they will give. After the test, the batteries should be put on the line again and charged before sending them out. The rates of discharge given here for the "starting-ability" tests may be varied if experience with a particular make of battery shows some other rate to be better. The important thing is to use the same rate of discharge for the same make and type of battery at all times. In this way the repairman will soon be able to distinguish between good and bad batteries of a particular make and type. Cadmium Tests may be made during the Starting Ability Discharge Tests. See page 174. "Cycling" Discharge Tests New batteries, or rebuilt batteries which have had new plates installed, or sulphated batteries which will not "come up" on charge, should be discharged when they have "come-up," as far as they will go. In some cases it is necessary to charge and discharge them several times before they will be ready for service. This charging and discharging is often called "cycling" the battery. New batteries are generally "cycled" at the factory before sending them out. The forming charge generally does not convert all the pastes into active material and the battery using plates which have been treated in the forming room is put through several discharges and charges after the battery is fully assembled. In service on a car, the battery is being "cycled" constantly and there is generally an increase in capacity after a battery is put on a car. Positive plates naturally increase in capacity, sometimes up to the very clay when they fall to pieces, while negatives tend to lose capacity with age. Batteries which are assembled in the service station, using new plates, generally require several cycles of charge and discharge before the specific gravity will rise to 1.280 before the positives will give 2.4-2.5 volts on a Cadmium test, before the negatives will give a reversed voltage reading of 0.175 to 0.20 volt on a Cadmium test, and before a satisfactory "starting-ability" or "breakdown" test can be made. A battery which has been abused by failing to add water to replace evaporation, by allowing to remain in a partially or completely discharged condition for sometime, or which has been allowed to become sulphated in any other way, will generally require "cycling" before it will "come-up" to a serviceable condition. The rates for a "cycling" discharge should be such that the battery will be discharged during the daytime, the discharge being started in the morning, and the battery being put back oil the charging line in the evening in order that it may be charging during the night. The rate of discharge should be somewhat higher than the rate used when the plates are formed. Two or three amperes per positive plate in each cell will generally be satisfactory. Discharge Apparatus A simple discharge rheostat is shown in Fig. 180. The terminal on the end of the cable attached to the right hand terminal of the battery shown in the illustration is movable, and it may be clamped at any point along the coils of wire so as to give various currents. The wire should be greased lightly to prevent rusting. [Fig. 180 Simple high rate discharge rheostat] Another simple apparatus consists of a board on which are mounted six double contact automobile lamp sockets which are all connected in parallel. A pair of leads having test clips attached is brought out from the sockets for fastening to the battery terminals. Lamps of various candlepower may be turned into the sockets to obtain different currents. Discharge tests are helpful in the case of a battery that has lost capacity. The battery is first fully charged, and is then discharged at the 5 hour rate. When the voltage of the battery has fallen to 1.7 volts per cell (measured while the battery is discharging) a Cadmium test is made to determine whether the positives or negatives are causing the lack of capacity. For further descriptions of the Cadmium Test see Page 174. In reviving sulphated batteries, it is sometimes necessary to charge and discharge the battery several times to put the active material in a healthy condition. Discharge tests at a high rate are very valuable in diagnosing the condition of a battery. A description of such tests will be found on Page 267. For making the heavy discharge tests a rheostat of the carbon plate type is suitable. With such a rheostat currents from 25 to more than 200 may be drawn from a six volt battery, and a smooth, even variation of a current may be obtained from the minimum to the maximum values. Such a rheostat is on the market and may be purchased complete with ammeter and leads for attaching to the battery. PACKING BATTERIES FOR SHIPPING Batteries which are shipped without electrolyte need merely have plenty of excelsior placed around them in a strong crate for protection from mechanical injury. Batteries which are shipped filled with electrolyte must be protected from mechanical injury and must also be packed so that it is difficult to turn the crate upside down and thus allow the electrolyte to run out. A very popular crate has been the so-called "dog-house," with a gable roof such as is actually used on dog-houses. The idea of such a roof is that it is impossible to place the crate with the roof down, since it will tip over if this is done. However, if these crates are placed side by side, it is a very simple matter to put a second row of crates on top of them, turning the second row up-side-down, as shown in Fig. 181, and allowing the electrolyte to run out. The men who load freight or express-cars have often shown great skill and cunning in packing "dog-house" crates in other ways so as to damage the batteries. Many have attained a high degree of perfection in breaking the crates. [Fig. 181 "Dog-house" crates for shipping batteries] Some sort of a roof on a battery crate is required by law, the idea being to make it difficult to turn the crate up-side-down. Perhaps the best crate would be one with a flat top marked "This Side Up," but such a crate would not comply with the law. [Fig. 182 Steps for construction of a crate for shipping battery] A better form of crate than the "dog-house" and one which complies with the law, is shown in Fig. 182. The top of each end piece is cut at an angle, the peak on one end being placed opposite the low point of the opposite end piece. Fig. 182 shows the steps in the construction of the crate. 1. The case should be built of strong lumber (11/2 inch preferably), and of ample size to allow packing with excelsior top, bottom, sides and ends to a thickness of two or three inches. Nail strongly. 2. When the case is complete (except cover) place a thick, even layer of excelsior (or packing straw) in the bottom and set in *he battery right side up. Lay paper (preferably paraffined) over top of battery to keep it clean, then pack tightly with excelsior sides and ends. 3. Now lay sufficient packing material on top of the battery so that cover will compress it tightly, stuffing it under cover boards as they are put on. The extended boards at bottom, and the gable roof are provided to prevent the battery from being tipped over; extensions of sides for carrying. Box should be plainly labeled: "HANDLE WITH CARE. DAMAGES CLAIMED IF TIPPED ON SIDE." In addition to the address of destination, as given in shipping instructions be sure to mark with name of shipper for identification upon arrival. When shipping by freight, the proper freight classification in the United States is "Electric Storage Batteries, Assembled." When shipping by express in the United States, "Acid" caution labels must be attached to each package. STORING SEPARATORS Separators which have been given the chemical treatment necessary to remove the substances which would cause trouble in the battery, and to make the wood porous, must be kept wet and never be allowed to become dry. A lead lined box, or large earthenware jars may be used as containers. Put the separators in the container and then pour in enough very weak electrolyte to cover the separators. This electrolyte may be made of I part of 1.220 electrolyte to 10 parts of distilled water, by volume. Be very careful to have the container absolutely clean and to use chemically pure acid and distilled water in making the weak electrolyte. Remember that impurities which are picked up by the separators will go into the battery in which the separators are placed. Therefore, keep the separator tank in a clean place and keep a cover on it. Have your hands clean when you take separators out of the tank to place in a battery, and do not put the separators on a dirty bench before inserting them between plates. The best thing to do is to hold the separators in one hand and insert them with the other, and not lay them on any bench at all. REINSULATION Separators are the weakest part of a battery and wear out while the other parts of a battery are still in good condition. Good plates are often ruined by weakened separators causing short-circuits. Many batteries which have to be junked after being in service about a year would have given considerable service if they had been reinsulated. Generally the separators of one cell wear out before those of the other cells. Do not, however, reinsulate that cell alone. The separators in the other cells are as old as those which have worn out, and are very near the breaking down point. If you reinsulate only one cell, the owner will naturally assume that the other cells are in good condition. What happens? A month or so later one of the other cells "goes dead." This does not have a very soothing effect on the owner, who will begin to lose confidence in you and begin to look around for another service station. If you explain frankly that it is useless to reinsulate only one cell of a battery and that the other cells will break down in a short time, the customer will want you to reinsulate all the cells. A somewhat higher bill for reinsulating all the cells at once will be more agreeable than having the cells break down one at a time within a month or two. In the case of the customers who come in regularly for testing and filling service, you will be able to tell when the separators are wearing out. When you find that a battery which has been in service about a year begins to run down frequently, and successive tests made in connection with testing and filling service show that the generator is not able to keep the battery charged, advise the owner to have the battery reinsulated. Do not wait for the battery to have a dead cell. Sell the owner on the idea that reinsulation will prevent the possibility of his battery breaking down when he may be out on a tour, and when it may be necessary to have his car towed in to a service station. If you allow the battery to remain on the car when it begins to lose its charge, the owner will not, of course, suspect that anything is wrong, and if his battery one day breaks down suddenly, lie will very likely lose confidence both in you and the battery, since he has been bringing in his car regularly in order to have his battery kept in good shape. The sudden failure of his battery will, therefore, make him believe that you do not know your business, or that the battery is a poor one. New separators will give every battery which is a year old a new lease on life. If you explain to a customer that he will get a much longer period of service from his battery if he has it reinsulated when the battery is a year old, you should have no trouble in getting the job, and the subsequent performance of the battery will show that you knew what you were talking about. SAFETY FIRST FOR THE BATTERY REPAIRMAN 1. Do not work on an empty stomach-you can then absorb lead easily. 2. Keep your fingers out of your mouth when at work. 3. Keep your finger nails short and clean. 4. Do not chew tobacco while at work. In handling tobacco, the lead oxides are carried to your mouth. Chewing tobacco does not prevent you from swallowing lead. 5. When you leave the shop at night, and before eating, wash your face, hands, and arms with soap, and clean your nose, mouth, and finger nails. 6. Do not eat in the repair shop. 7. Drink plenty of good milk. It prevents lead poisoning. 8. Use Epsom Salts when constipated. This is very important. 9. Bathe frequently to prevent lead poisoning. 10. Leave your working clothes in the shop. 11. It is better not to wear a beard or mustache. Keep your hair covered with a cap. 12. Before sweeping the shop dampen the floor to keep down the dust. 13. Do not drink beer or whisky, or any other alcoholic liquors. These weaken your system and make you more susceptible to lead poisoning. 14. In handling lead, wear gloves as much as possible, and wash and dry the gloves every day that you wear them. 15. Wear goggles to keep lead and acid out of your eyes. 16. When melting lead in a hydrogen flame, as in burning on the top connectors, the fumes given off may be blown away by a stream of air. The air supply to the flame may be tapped for this purpose. 17. The symptoms of lead poisoning are: gums darken or become blue, indigestion, colic, constipation, loss of appetite, muscular pain. In the later stages there is muscular weakness and paralysis. The hands become limp and useless. 18. Wear rubber shoes or boots. Leather shoes should be painted with a hot mixture of equal parts of paraffine and beeswax. 19. Wear woolen clothes if possible. Cotton clothing should be dipped in a strong solution of baking soda and dried. Wear a flannel apron covered with sacking. 20. Keep a bottle of strong ammonia handy. If you should spill acid on your clothes, apply some of the ammonia immediately to neutralize the acid, which will otherwise burn a hole in your clothes. 21. Keep a stone, earthenware, or porcelain jar filled with a solution of washing soda or baking soda (bicarbonate of soda). Rinse your hands in this solution occasionally to prevent the acid from irritating them. 22. If you should splash acid in your eye, wash it out immediately with warm water, and drop olive oil on the eye. If you have no olive oil at hand, do not wait to get some, but use any, lubricating oil, or vaseline. TESTING THE ELECTRICAL SYSTEM "Out of sight, out of mind," is a familiar saying. But when does it hold true? What about the battery repairman? Are the batteries he repairs "out of sight, out of mind?" Does his responsibility end when he has installed a battery on a car? Suppose he put a battery in first class shape, installs it on a car, and, after a week or two the battery comes back, absolutely dead? Is the battery at fault, or is the repairman to blame for neglecting to make sure that the battery would be given a reasonably good chance to give good service and receive fair treatment from the other part of the electrical system? The actual work on the battery is finished when the battery cables are fastened to the battery terminals. But real battery SERVICE does not end there. The battery is the most important part of the electrical system of a car, but it is only one part, and a good battery cannot be expected to give satisfactory service when it is connected to the other parts of the electrical system without making sure that these parts are working properly, any more than a man wearing new, shoes can step into a mud puddle and not have his shoes covered with dirt. The battery functions by means of the current which flows through it by way of the cables which are connected to its terminals. A battery is human in many respects. It must have both food and exercise and there must be a proper balance between the food and the exercise. Too much food for the amount of exercise, or too much exercise for the amount of food consumed will both lead to a lowering of efficiency, and disease frequently results. A battery exercises when it turns over the starting motor, furnishes energy to the lamps, or operates the a ignition system. It receives food when it is charged. Proper attention to the electrical system will result in a correct balance between food and exercise, or in other words, charge and discharge. The electrical equipment of a car consists of five principal parts: 1. The Battery. 2. The Ignition System. 3. The Starting Motor. 4. The Generator. 5. The Lighting System. The normal course of operation of this system is as follows: Starting. The ignition switch is closed, and connects the ignition system to the battery. The starting switch is then closed, connecting the starting motor to the battery. The battery sends a heavy current through the starting motor, causing the motor to turn over, or "crank" the engine. The motion of the engine pistons draws a mixture of air and gasoline vapor into the cylinders. At the proper instant sparks are made to jump between the points of the spark plugs, igniting the air and gasoline vapor mixture, forming a large amount of gas. This gas expands, and in doing so puts the engine into motion. The engine begins to run under its own power and the starting switch is opened, since the starting motor has performed the work required of it, and has nothing further to do as long as the engine runs. The engine now operates the generator. The generator begins to build up a voltage as the engine speed increases. When the voltage of the generator has risen to about 7-7.5, the generator is automatically connected to the battery by the cutout (also known as reverse-current relay, cut-out relay, or relay). The voltage of the generator being higher than that of the battery, the generator sends a current through the battery, which "charges" the battery. As long As the engine continues to run above the speed at which the generator develops a voltage higher than that of the battery, a charging current will normally flow through the battery. When the ignition switch is opened the engine can no longer develop any power and consequently stops running. When the decreasing engine speed causes the generator speed to drop to a point at which the generator voltage is less than that of battery, the battery sends a reverse, or discharge current through the cutout and generator, thereby causing the cutout to open and disconnect the generator from the battery. Lights. When the engine is not running, the battery furnishes current to the lights. This is a discharge current. When the engine runs at a speed which is greater than that at which the the cutout closes, the generator furnishes current for the lights, and also for the ignition system, in addition to sending a charging current through the battery. From the foregoing description, we see that the battery is at rest, is discharging, or charging under the following conditions: Engine Not Running, Lamps Off, Ignition Off. Under these conditions all switches are open, and hence no current should be passing through the battery. If a current is found to be passing through the battery under these conditions, it is a discharge current which is not doing any work and is caused by a defective cutout, defective switches, or grounds and short-circuits in the wires, cables, or apparatus connected to the battery. Starting the Engine. A heavy discharge current is drawn from the battery. This current should not flow more than 10 seconds. If the starting motor does not crank the engine or cranks it too slowly, the motor or the cables and switch connecting the motor to the battery are defective, assuming that the battery is large enough and is in a good condition. If the starting motor cranks the engine, but the engine does not begin to run under its own power within ten seconds, the starting system is not at fault, and the starting switch should be opened. Engine Not Running, All Lamps On. A discharge current flows from the battery which is equal to the sum of the currents drawn by lamps when connected to the battery separately. If the current is greater than this sum, trouble is present. Engine Running, Lamps Off. The generator sends a charging current into the battery and also supplies current to the ignition system (except when a magneto is used). If the generator does not send a charging current through the battery there is trouble in the generator, or in the parts connecting the generator to the battery (assuming the battery to be in a good condition). If the generator sends a current through the battery, it may be of the correct value, it may be insufficient, or it may be excessive. A normal current is one which keeps the battery fully charged, but does not overheat it or cause excessive gassing. An insufficient current is one which fails to keep the battery charged. An excessive charging current is one which keeps the battery charged, but which at the same time overheats the battery and causes excessive gassing. The excessive current may also overheat the generator, while a normal or insufficient charging current will not injure the generator. It is possible, but not probable, that the generator may be sending current through the battery in the wrong direction, so as to discharge it instead of charging it. This will happen if a very badly discharged battery is installed with the connections reversed. If a fully or even partly charged battery is installed with its connections reversed, the battery will generally reverse the polarity of the generator automatically, and the battery will be charged in the proper direction, although the current flow in the charging circuit is actually reversed. Engine Running, Lamps On. Under these conditions, the generator should supply the current for the lights, and still send a charging current of 3 to 5 amperes through the battery. This means that the current drawn from the battery when the engine is not running and the lights are all turned on should be at least several amperes less than the charging current which the generator sends into the battery when the engine is running and the lamps are turned off. Tests to Be Made by the Repairman The battery repairman can, and always should, make a few simple tests which will tell him whether the various conditions of operation are normal. This should be done as follows: 1. Install the battery carefully (see page 236), and connect the negative battery cable to the negative battery terminal. Now tap the positive battery cable on the positive battery terminal. If a snappy spark is obtained when this is done, some of the switches are open or are defective, the cutout is stuck in the closed position, or there are grounds or short-circuits in the parts which are permanently connected to the battery. Even though no spark is obtained when you tap the positive battery cable on the positive battery terminal, there may be some trouble which draws enough current from the battery to cause it to run down in a short time. To detect such trouble, connect a voltmeter (which has sufficient range to indicate the battery voltage) between the positive battery cable and the positive battery terminal. (Cable is disconnected from the terminal.) If the voltmeter now gives a reading equal to the voltage of the battery, there is some condition causing a current leakage from the battery, such as a cutout stuck in the closed position, defective switches which do not break the circuits when in the open position, or grounds or short-circuits in the cables and wires connected to the battery. If the voltmeter pointer does not move from the "0" line on the scale, complete the battery connections by fastening the positive battery cable to the positive battery terminal, and make the test described in Section 2. If the voltmeter pointer moves from the "0" line, and gives a reading equal to the battery voltage, connect the voltmeter permanently between the positive battery cable and the positive battery terminal and make a general inspection of the wiring, looking for cut or torn insulation which allows a wire or cable to come in contact with the frame of the car, or with some other wire or cable, thereby causing a ground or short-circuit. Old, oil-soaked insulation on wires and cables will often cause such trouble. If a general inspection does not reveal the cause of the current leakage, proceed as follows: Closed Cutout, or Defective Cutout Windings. (a) If the cutout is mounted outside the generator, remove the cover from it and see if the points are stuck together. If they are, separate them and see if the voltmeter pointer returns to the "0" line. If it does, you have found the trouble. The points should be made smooth with 00 sandpaper. See that the moving arm of the cutout moves freely and that the spring which tends to hold the arm in the open position is not weak or broken. If the voltmeter pointer does not return to the "0" line when the cutout points are separated, or if the points were not found to be stuck together, disconnect from the cutout the wire which goes to the ammeter or battery. If this causes the voltmeter pointer to return to the "0" line, the cutout is defective and a new one should be installed, unless the trouble can be found by inspection and repaired. If the voltmeter pointer does not return to the "0" line when the battery or ammeter wire is disconnected from the cutout, see paragraph (d). (b) If the cutout is mounted inside the generator, disconnect from the generator the wire which goes to the ammeter or indicator. If this causes the voltmeter pointer to return to the "0" line, the cutout points are stuck together or the cutout is defective, and the generator should be taken apart for inspection. If this does not cause the voltmeter pointer to return to the "0" line, replace the wire and see paragraph (d). (c) If no cutout is used and connections between the generator (or motor-generator) and the battery are made by closing the ignition or starting switch, such as is the case on Delco and Dyneto motor-generators, and some Delco generators, disconnect from the generator or motorgenerator the wire that goes to the ammeter or indicator. If this causes the voltmeter pointer to return to the "0" line, the switch which connects the generator or motor-generator to the ammeter or indicator is defective. If the voltmeter pointer does not return to the "0" line, replace the wire and consult paragraph (d). (d) Defective Starting Switch. Disconnect from the starting switch the cable that goes to the battery. If one or more smaller wires are connected to the same terminal as the heavy cable, disconnect them also and hold their bare ends on the bare end of the heavy cable. If this causes the voltmeter pointer to return to the "0" line, the starting switch is defective. If the voltmeter pointer does not return to the "0" line, replace the cable and wires on the starting switch terminal and proceed as follows: Defective Switches. See that the ignition and lighting switches are in their "OFF" positions. If they are not, open them and see if the voltmeter pointer returns to the "0" line. If it does, you have found the trouble. If it does not, disconnect from the switch (or switches, if there are separate lighting and ignition switches), the feed wire which supplies current to the switch from the battery. If this causes the voltmeter pointer to return to the "0" line, the switches are defective. If the pointer does not return to the "0" line, replace the wires on the switch and consult the next paragraph. If there are other switches which control a spot light, or special circuits, such as tonneau lamps, or accessories, such as gasoline vaporizers, electric primers, etc., make the same tests on these switches. If no trouble has been found, see paragraph (e). (e) Grounds or Short-Circuits in Wiring. Disconnect from each terminal point in the wiring system the wires which are connected together at that point. Also remove fuses from the fuse blocks. If the voltmeter pointer returns to the "0" line when a certain wire or fuse is removed, there is a ground or short-circuit in the wire or in the circuit to which the fuse is connected. (f) Turn on the Lights. Remove the voltmeter and complete the battery connection. Note how much current is indicated on the ammeter mounted on the instrument panel of the car as the different lamps are turned on. In each case the ammeter should indicate "discharge." Should the ammeter indicate "charge" the battery connections have been reversed, or the ammeter connections are reversed. The driver will tell you whether the ammeter has been reading "charge" or "discharge" when the lamps were turned on. This is a good way to check your battery connections. If the car has no ammeter, or has an indicator which is marked "ON" or "OFF," or "Charge" or "Discharge," an ammeter may be connected in series with the battery by disconnecting the cable from the positive battery terminal and connecting the ammeter to the cable and to the terminal, and the readings obtained from this meter. The amperes indicated on the ammeter should be the greatest when the main headlamps are burning bright. By comparing the readings obtained when the different lighting combinations are turned on, it is sometimes possible to detect trouble in some of the lighting lines. 3. Start the Engine. Before you do this, be sure that the cables are connected directly to the battery terminals, and that no ammeter or voltmeter is connected in series with the battery, as the heavy current drawn by the starting motor would ruin the instruments very quickly. An ammeter may be left connected in series with the battery, providing that a switch is used to short-circuit the meter while starting the engine. A meter having a 500 ampere scale may be left connected in series with the battery while the engine is being started, but for the tests which are to be made a 25 ampere scale should be used. The engine should start within ten seconds after the starting switch is closed. If more time than this is required, carburetor adjustments, position of the choke lever, etc., should be looked after. Continued cranking of the engine will run the battery down very quickly, and the chances are that the car will not be run long enough to allow the generator to recharge the battery. Make whatever adjustments are necessary to reduce the cranking time to ten seconds, or advise the owner to have them made, warning him that otherwise you will not be responsible if the battery runs down very quickly. 4. When the engine has started, set the throttle lever so that the engine runs As slowly as possible. The ammeter (either that on the instrument panel, or a special test ammeter connected in series with the battery) will indicate several amperes discharge, this being the current taken by the ignition system. Now speed up the engine gradually. At an engine speed corresponding to a car speed of 7 to 10 miles per hour in high (if there is any difficulty in estimating this speed, drive the car around the block while making this and the following tests) the ammeter pointer should move back to, or slightly past, the "0" line, showing that the cutout has closed. If the ammeter needle jumps back and forth and the cutout opens and closes rapidly, the polarity of the battery and that of the generator are not the same. This condition may be remedied by holding the cutout points closed for several seconds, or by short-circuiting the "Battery" terminal on the cutout with the "Generator" terminal on the cutout. After a slight movement of the ammeter pointer indicates that the cutout has closed, speed up the engine gradually. When the engine speed corresponds to a car speed of 18-25 miles per hour in "high," the current indicated on the ammeter should reach its maximum value and the pointer should then stop moving, or should begin to drop back toward the "0" line as the speed is increased. For average driving conditions, the maximum charging current should not exceed 12 to 14 amperes for a 6 volt, 11 to 13 plate battery, and 6 to 7 amperes for a 12 volt battery. (These currents should be obtained if "constant-current" generators, such as the "third brush," "reversed-series," or vibrating current regulators are used. The "third brush" type of generator is used on more than 99 per cent of the modern cars. Some cars use a "constant-voltage" regulated generator, such as the Bijur generator, having a voltage regulator carried in a box mounted on the generator. On all cars using a "constant-voltage" generator, the charging rate when the battery is fully charged should not exceed five amperes for a six volt generator). If the generator has a thermostat, such as is used on the Remy generators, the charging rate will be as high as 20 amperes until the generator warms up, and then the charging rate will drop to 10-12 amperes, due to the opening of the thermostat points, which inserts a resistance coil in series with the shunt field. If the charging current reaches its maximum value at 18-25 miles per hour, and shows no increase at higher speeds, decrease the engine speed. When the engine is running at a speed corresponding to a car speed of about 7 miles per hour, or less, the cutout should open, indicated by the ammeter indicating several amperes discharge, in addition to the ignition current, for an instant, and then dropping back to the amount taken by the ignition system. Now turn on the headlights (and whatever lamps are turned on at the same time) and speed the engine up again. The ammeter should indicate some charging current at engine speeds corresponding to the usual speed at which the car is driven. If it does not, the charging current should be increased or smaller lamps must be installed. Troubles The operation of the electrical system when the engine is running may not be as described in the foregoing paragraphs. Troubles may be found as follows: 1. Cutout does not close until engine reaches a speed in excess of 10 miles per hour. This trouble may be due to the cutout or to the generator. If the ammeter shows a charging current of three amperes or more as soon as it closes, the cutout is at fault. The thing to do in such a case is to adjust the cutout. First see that the movable armature of the cutout moves freely and does not bind at the pivot. If no trouble is found here, the thing to do is to decrease the air gap which exists between the stationary and movable cutout points when the cutout is open., or to decrease the tension of the spring which tends to keep the points open. On most cutouts there is a stop which the cutout armature strikes when the cutout opens. By bending this stop the air-gap between the points may be decreased. This is the adjustment which should be made to have the cutout close earlier, rather than to decrease the spring tension. Some cutouts have a spiral spring attached to the cutout armature. Others have a flat spring. On still others, the spring forms the connection between the armature and the cutout frame. In the first two types, the spring tension may be decreased, but wherever possible the air-gap adjustment should be made as described. If the cutout closes late, and only about an ampere of charging current is indicated on the ammeter, and the cutout points are fairly clean and smooth, the trouble is generally in the generator. The generator troubles which are most likely to exist are: a. Dirty commutator. b. Dirty brush contact surface. c. Loose brushes. d. Brushes bearing on wrong point of commutator (to set brushes properly, remove all outside connections from generator, open the shunt field circuit, and apply a battery across the main brushes. Shift the brushes until the armature does not tend to rotate in either direction. This is, of course, a test which must be made with the generator on the test bench). e. Loose connections in the shunt field circuit. The foregoing conditions are the ones which will generally be found. More serious troubles will generally prevent the generator from building up at all. 2. Cutout does hot open when engine stops. This condition is shown by a discharge current of about 5 amperes when the engine has stopped. (In Delco systems which have no cutout, an even greater discharge will be noted as long as the ignition switch remains closed.) This trouble is generally due to cutout points stuck together, a broken cutout spring, or a bent or binding cutout armature. 3. Cutout does not open until ammeter indicates a discharge of three or more amperes (in addition to the ignition discharge). This may be remedied by increasing the spring tension of the cutout, or removing any trouble which causes the cutout armature to bind. On many cutouts the armature does not actually touch the core of the cutout winding when the points are closed, there being a small piece of copper or other non-magnetic metal on the armature which touches the end of the cutout and maintains a small air gap between the core and armature, even when the points are closed. The opening action of the cutout may be changed by filing this piece of non-magnetic material so as to decrease the air gap, or pinching it with heavy pliers so as to make it stand farther out from the cutout armature and thus increase the air gap between the armature and core when the points are closed. Decreasing this air gap will cause the cutout to open late, and increasing it will cause the cutout to open early. 4. Cutout will not close at any engine speed. If cutout does not close the first time the engine speed is increased, stop the engine. This condition may be due to a defective cutout, an open-circuit in the charging line, a ground or short-circuit between the cutout and the generator, or a defective generator. To determine whether the cutout is defective, remove the wires from it and hold together the ends of the wires coming from the generator, and the one going to the ammeter. Start the engine. If no other trouble exists, the ammeter will indicate a charging current at speeds above 8-10 miles per hour. If no current is obtained, stop the engine. If the cutout trouble consisted of an open circuit in one of its windings, or in the points not closing, due to dirt or a binding armature, or if there is an open-circuit in the charging line, the generator will, of course, have been running on open-circuit. This will cause the fuse in the shunt field circuit to blow if there is such a fuse, and if there is no such fuse, the shunt field coils may be burned open, or the insulation on the field coil wires may have become overheated to a point at which it burns and carbonizes, and causes a short-circuit between wires. Such troubles will, of course, prevent a generator from building up when the cutout wires are disconnected and their ends held together. If there is a ground in the cutout, or between the cutout and the generator, the generator will very likely be unable to generate (if a "one-wire" system is used on the car). If there is some defect in the generator-such as dirty commutator, high mica, brushes not touching, commutator dirty, or loose brushes, brushes too far from neutral, grounded brushes, brushes not well ground in, wrong type of brushes, grounded commutator or armature windings, short-circuited commutator or armature windings, open-circuited armature windings, grounded field windings, short-circuited field windings, open-circuit or poor connections in field circuit, one or more field coil connections reversed, wrong type of armature or field coils used in repairing generator, generator drive mechanism broken-then the generator will not build up. If no charging current is, therefore, obtained when the generator and ammeter wires are disconnected from the cutout and their ends held together, there may be a ground or short-circuit in the cutout windings or in the circuit between the generator and the cutout, or the generator may be defective, due to having been operated on open-circuit, or due to troubles as described in the foregoing paragraph. The presence of a ground or short in the circuit between the generator and cutout or in the cutout may be determined by disconnected the wire from the generator, disconnecting the battery (or ammeter) wire from the cutout, and running a separate extra wire from the generator to the wire removed from the cutout. Then start the engine again. If a charging current is obtained, there is a ground or short either in the cutout or in the circuit between the cutout and the generator. (It is also possible that the failure of the generator to build up was due to poor brush contact in the generator. The use of the extra wire connected the generator directly to the battery, thus magnetizing the generator fields and causing generator to build up. If poor brush contact prevented the generator from building up, closing the cutout by hand will often cause the generator to start charging. If you can therefore cause the generator to build up by holding the cutout points closed by hand, or by shorting across from the generator terminal to the battery terminal of the cutout, it is probable that the generator brushes are not making good contact). The cutout may be tested by stopping the engine, replacing the battery (or ammeter) wire on the cutout, and holding the end of the extra wire on the generator terminal of the cutout. If a charging current is then obtained, the cutout is 0. K. and the trouble is between the cutout and the generator. 5. An excessive current is obtained. If a third brush generator is used, look for loose or dirty connections in the charging line, dirty cutout points, dirty commutator, dirty brushes (especially the brush, or brushes, which is Dot connected to one end of the field winding), brushes loose, brushes not well ground in, and any other conditions which will cause a high resistance in the charging line. It is characteristic of third brush generators that their current output increases if there is an increase in resistance in the charging circuit. If no troubles such as those enumerated above are found, the third brush may need adjusting. Generators using vibrating current or voltage regulators will give an excessive output if the points need adjusting or if the regulating resistance is short-circuited. Generators using reversed series regulation will give an excessive output if there is a short-circuit in the series field coils. 6. Low charging current is obtained. This may be due to adjustment of the regulating device, to high resistance in the shunt field circuit in case of a third brush generator. In case of generators using other kinds of regulation, loose connections, dirty commutator and brushes, etc., will cause low charging current. 7. Generator charges up to a certain speed and then stops charging. The trouble is caused by some condition which causes the brushes to break contact with the commutator, especially in the case of a "third" brush. High mica, loose brush spring, or a commutator which has been turned down off-center may cause the trouble. This trouble most frequently occurs on cars using third brush motor-generators having a 3 to 1 or more speed ratio between them and the engine. These motor-generators operate at such high speeds that high mica and a commutator which is even slightly off center have a much greater effect than the same conditions would cause in separate generators which operate at much lower speeds. The remedy for this trouble is to keep the mica under-cut, and to be very careful to center the armature in the lathe when taking a cut from the armature. In turning down the commutators of high speed motor-generators, special fittings should be made by means of which the armature may be mounted in its own ball-bearings while the commutator is turned down. ADJUSTING GENERATOR OUTPUTS The repairman should be very slow in adjusting generator outputs. Most cases of insufficient or excessive charging current are due to the troubles enumerated in the foregoing paragraphs, and not due to incorrect adjustment of the regulating device. Before changing the adjustment of any generator, therefore, be sure that everything is in good condition. The third brush generator, for instance, will have an excessive output if the brushes are dirty, loose, or not well seated on the commutator. The use of a third brush which is too wide, for instance, will change the output considerably. A high resistance third brush will decrease the output, while a low resistance brush will increase the output. On the other hand, an increase in the resistance of the charging circuit will cause an increase in the output of a third brush generator, which is just the opposite to what is ordinarily expected. Such an increase in resistance may be due to loose or dirty connections, dirty cutout contact points, corroded battery terminals and so on. Remember also that the third brush generator sends a higher current into a fully charged battery than it sends into a discharged battery. It is, therefore, essential that a fully charged battery be on the car when the output of a third brush generator is adjusted. There are two things which determine whether any change should be made in the charging rate on the car, viz: Driving, Conditions and the Season of the Year. Driving Conditions. A car which makes short runs, with numerous stops, requires that the starting motor be used frequently. This tends to run the battery down very quickly. Moreover, such a car usually does not have its engine running long enough to give the generator an opportunity to keep the battery charged, and to accomplish this, the charging rate should be increased. A car which is used mostly at night may need a higher charging rate, especially if short runs are made, and if the car stands at the curb with its lights burning. Long night runs will generally call for only a normal charging rate, since the long charging periods are offset by the continuous use of the lamps. A car used on long daylight runs should generally have the charging rate reduced, because the battery is charged throughout such runs with no discharge into lamps or starting of motor to offset the continued charge. If the lamps are kept lighted during such runs, the normal charge rate will be satisfactory, because the lamp current will automatically reduce the current sent into the battery. In the winter time, engines must be cranked for a longer time before they will start, the battery is less efficient than in warm weather, and lights are burning for a greater length of time than in summer. Such conditions require an increase in the charging rate, especially if the car is used on short runs. Oil long runs in the winter time, the normal charging rate will generally be satisfactory because the long charging period will offset the longer cranking period. In the summer time, engines start more easily than in winter, and hence require less cranking. The lamps are used for only short periods and the battery is more efficient than in winter. A lower charging rate will, therefore, keep the battery charged. Long tours in the summer time are especially likely to result in overcharged, overheated batteries, and a reduced charging rate is called for. How and When to Adjust Charging Rates A correct charging rate is one which keeps a battery fully charged, but does not overcharge it, and which does not cause either the generator or the battery to become overheated. The only way to determine whether a certain charging rate is correct on any particular car is to make an arrangement with the car owner to bring in his car every two weeks. On such occasions hydrometer readings should be taken and water added, if necessary, to bring the surface of the electrolyte up to the proper level. The hydrometer readings will show whether the generator is keeping the battery charged, and if a change in the charging rate is necessary, the necessary adjustments may be made. If a customer does not bring in his car every two weeks, call him up on the phone or write to him. The interest which you show in his battery by doing this will generally result in the customer giving you all his repair business, and he will also tell his acquaintances about your good service. This will give you considerable "word of mouth" advertising, which is by far the best form of advertising and which cannot be bought. It must be earned by good battery service. Adjusting a third brush generator. The best rule to remember for changing the output of a third brush machine is that to increase the output, move the third brush in the direction in which the commutator rotates, and to decrease the output, move the third brush in the opposite direction. Move the third brush only 1/16 inch and then sandpaper the brush seat with 00 sandpaper. Allow the generator to run for about twenty minutes to "run-in" the brush. Then vary the speed to see what the maximum charging rate is. If the change in the charging rate is not sufficient, move the third brush another 1/16 inch and proceed as before until the desired charging rate is obtained. Adjusting Vibrating Regulators. The output of generators which use a vibrating regulator is adjusted by changing the tension of the spring fastened to the regulator arm. In many cases this adjustment is made by means of a screw which is turned up or down to change the spring tension. In other cases a hook or prong is bent to change the spring tension. Where a coil spring is used, lengthening the spring will decrease the tension and lower the output, while shortening the spring will increase the tension and raise the output. Vibrating regulators are of the "constant" current or the "constant-voltage" types. The constant current regulator has a winding of heavy wire which carries the charging current. When the charging current reaches the value for which the regulator is set, the electromagnet formed by the coil and the core on which it is wound draws the regulator armature toward it and thereby separates the regulator points, which are in series with the shunt field. A resistance coil, which is connected across the regulator points and which is short-circuited when the points are closed, is put in series with the shunt field when the points separate. This reduces the shunt field current, causing a decrease in generator voltage and hence current output. As the current decreases, the pull of the electromagnet on the regulator armature weakens and the spring overcomes the pull of the electromagnet and closes the regulator points. This short-circuits the resistance coil connected across the regulator points and allows the shunt field current to increase again, thereby increasing the generator output. This cycle is repeated at a high rate of speed, causing the regulator points to vibrate rapidly. The action of a vibrating "constant-voltage" regulator is exactly the same as that of the "constant current" regulator, except that the coil is connected across the generator brushes. The action of this coil therefore depends on the generator voltage, the regulator points vibrating when the generator voltage rises to the value for which the regulator is set. Adjusting Reverse-Series Generators. The regulation of the output of this type of generator is accomplished by means of a field winding which is in series with the armature, and which therefore carries the charging current. These series field coils are magnetically opposed to the shunt field coils, and an increase in charging current results in a weakening of the field flux. A balanced condition is reached at which no increase of flux takes place as the generator speed increases, the tendency of the increased shunt field current to increase the total flux being counterbalanced by the weakening action of the flux produced by the series field current. To increase the output of a reverse series generator, it is necessary to weaken the opposing series field flux. The only way of doing this is to short-circuit the series field coils, or connect a resistance across them. To decrease the output of a reverse series generator, a resistance coil may be connected in series with the shunt field winding. Neither of these schemes is practicable, and hence the reverse series generator may be considered as a "non-adjustable" machine. Under-charging may be prevented by using the starting motor and lights as little as possible, or by giving the battery a bench charge occasionally. Over-charging may be prevented by burning the lights whenever the engine is running, or leaving the lights turned on over night. Other forms of regulation have been used on the older cars, but the majority of the cars now in use use one of the four forms of regulation described in the foregoing paragraphs. If adjustments need to be made on some car having a system of-regulation with which the battery man is not familiar, the work should be done in a service station doing generator work. If generator outputs are changed because of some special operating condition, such as summer tours, the rate should be changed to normal as soon as the usual driving conditions are resumed. TESTING AND FILLING SERVICE Every man expects to be paid for his work, since his purpose in working is to get money. Yet there are numerous instances in every line of work requiring work to be done for which no money is received. The term "Free Service" is familiar to every repairman, and it has been the cause of considerable discussion and dispute, since it is often very difficult to know where to draw the Tine between Free Service and Paid Service. The term "Free Service" might be abolished with benefit to all concerned. In the battery business "Free Inspection" service is a familiar term. It is intended to apply to the regular addition of distilled water by the repairman and to tests made at the time the water is added. Since the term "Inspection" might be Misinterpreted and taken to apply to the opening of batteries for examination, the term "Testing and Filling Service" should be used instead of "Free Inspection Service." Battery makers furnish cards for distribution to car owners. These cards entitle the holder to bring in his battery every two weeks to have distilled water added if necessary, and to have his battery tested without paying for it. This service requires very little time, and should be given cheerfully by every service man. "Testing and Filling Service" is an excellent means of becoming acquainted with car owners. Be as pleasant and courteous to the "Testing and Filling" customer as you are to the man who brings in a battery that needs repairs. For this customer will certainly give you his repair business if you have been pleasant in giving the Testing and Filling Service. A thoroughly competent battery man should be put in charge of the Testing and Filling Service, since this man must meet the car owners, upon whom the service station depends for its income. Customers are impressed, not by an imposing array of repair shop equipment, but by the manner of the men who meet them. These men will increase the number of your customers, or will drive trade to competitors, depending on the impression they leave in the minds of the car owners. Every service station owner should persuade all the car owners in the vicinity of the station to come in regularly for the free testing and filling service, and when they do come in they should be given cheerful, courteous service. Each "testing" and "filling" customer is a prospective paying customer, for it is entirely natural that a car owner will give his repair work to the battery man who has been taking care of the testing and filling work Oil his battery. When a new battery is needed, the "testing" and "filling" customer will certainly buy it from the man who has been relieving him of the work of keeping his batteries in good shape. Car owners who depend on your competitor for their "testing and filling" service will not come to you when their battery needs repairing, or when they need a new battery. You may be convinced that you handle a better make of battery than your competitor does, but your competitor's word will carry far more weight than yours with the man who has been coming to him for testing and filling. Good testing and filling service is, therefore, the best method of advertising and building up your business. The cost of this service to you is more than offset by the paying business it certainly brings, and by the saving in money spent for advertising. Remember that a boost by a satisfied customer is of considerably greater value to your business than newspaper advertising. A careful record should be kept of every battery which is brought in regularly for testing and filling service. If a test shows that one or more cells are low in gravity, say about 1.220, this fact should be recorded. If the gravity is still low when the battery comes in again for test, remove the battery and give it a bench charge. The customer should, of course, pay for the bench charge and for the rental battery which is put on the car in the meantime. Battery manufacturers generally furnish cards to be used in connection with the testing and filling service, such cards being issued to the customers. A punch mark is made every time the battery is brought in, If the owner neglects to come in, this is indicated by the absence of a punch mark, and puts the blame for any trouble caused by this neglect on the owner if any cell shows low gravity, a notation of that fact may be made opposite the punch mark for the date on which the low gravity was observed. If the low gravity is again found the next time the battery is brought in, the battery should be removed and given a bench charge. If the bench charge puts the battery in good shape, and the subsequent gravity readings are high, no trouble is present. If, however, the low gravity readings begin to drop off again, it is probable that new separators are required, especially if the battery is about a year old. The logical course of events in the testing and filling service is to keep the battery properly filled (at no cost to the customer), give the battery an occasional bench charge (for which the customer pays), reinsulate the battery when it is about a year old (for which the customer pays), and sell the customer a new battery when the old one is worn out. If some trouble develops during the lifetime of the battery which is not due to lack of proper attention, the customer should pay to have the repairs made. From this the battery man will see how the Testing and Filling Service pays. The way to get business is to have people come to your shop. Become acquainted with them, treat them right, and you need not wonder where the money is to come from. SERVICE RECORDS In order to run a repair shop in an orderly, business-like manner, it is necessary to have an efficient system of Service Records. Such a system will protect both the repairman and the customer, and simplify the repairman's bookkeeping. For a small service station a very simple system should be adopted. As the business grows, the service record system must necessarily become more complicated, since each battery will pass through several persons' hands. Battery manufacturers generally furnish service record sheets and cards to their service stations, and the repairman who has a contract with a manufacturer generally adopts them. The manufacturers' service record systems are often somewhat complicated, and require considerable bookkeeping. For the smaller service station a single sheet or card is most suitable, there being only one for each job, and carbon sheets and copies being unnecessary. Such a service record has three essential parts: (a) The customer's claim check. (b) The battery tag. (c) The record card. Fig. 183 shows a service record card which is suitable for the average repair shop. Part No. I is the customer's claim check, Part No. 2 the battery tag, and part No. 3 the record card, and is 5 inches by 8 inches in size. The overall size of the entire card is 5 inches by 12 inches. Parts I and 2 are torn off along the perforated lines marked (A). When a battery comes in the three parts are given the same number to identify them when they have been torn apart. The number may be written in the "No." space shown on each part, or the numbers may be stamped on the card. The record should not be made out as soon as a customer comes in, but after the battery has been examined and tested and the necessary work determined. Put the customer's name on parts 2 and 3. Record the address, telephone, etc., in the proper spaces on part 3. Having determined by test and inspection what is to be done, fill out the "WORKCOSTS" table on part 3, putting a check mark in the first column to indicate the work to be done and the material needed. Figure up the cost while the customer waits, if this is possible. Explain the costs to the customer, and have him sign Contract No. 1. If you do this there can never be any argument about the bill you hand the customer later If the customer cannot wait, or if he is well known to you and you know lie will not question your bill, have him sign Contract No. 2. In either case, the terms printed on the back of the card authorize the repairman to make whatever repairs he finds to be necessary, and bind the customer to pay for them. Find out whether the customer will call, whether you are to deliver the battery, or whether you are to ship it, and put a check mark in the proper space at the right of the "WORK-COSTS" table. Mark the battery with the chalk whose color is indicated, and you will know how to dispose of the battery when the repairs are completed. Fill out the claim check and give it to the customer, tearing it off along the perforated lines. Fill out the battery tag, indicating after "Instructions" just what is to be done. [Fig. 183 Front & Back of the Battery Service Card] Make a sketch of the top of the battery in the space provided, dip the tag in the paraffine dip pot (see page 182) and tack the card on the battery. File part 3 in a standard 5 by 8 card index file. To the right of the "WORK-COSTS" table are spaces for entering the date on which the work is completed, the date the customer is notified and the date the battery goes out. These dates are useful in keeping a record of the job. When the job is finished and the rental comes in, enter the costs in the "COSTS" table, and note the date the bill was paid, in the space marked "PAID." [Fig. 184 Rental battery card to be tied on car of customer] File all the 5 by 8 cards (Part 3) in alphabetical order in a "dead" ticket file, in either alphabetical or numerical order. With this file you can build up an excellent mailing list of your customers. You can note how many new customers you are securing and how many customers are not coming back. The latter information is very valuable, as it enables you to find out what customers have quit, and you can go after them to get their repair business again. When a rental is put on a card, the card shown in Fig. 184 may be tied to the car where it is easily seen. This will serve as a reminder to the customer and will help advertise your shop to those who ride in the car. Each rental battery should have a number painted on it in large white letters, or should have attached to it at all times a lead tag on which is stamped a number to identify the battery. To keep a record of the rental batteries, a card or sheet similar to that shown in Fig. 185 may be used. Each time the rental is put on a car, a record is made of this fact on the card. Each rental battery has its own card, and reference to this card will show at once where the battery is. Each card thus gives a record of the battery. The number of the rental is also written on the Stock Card shown in Fig. 183, but the purpose of putting the number on these cards is merely to make sure that the battery is returned when the customer's battery is replaced on the car and to be able to figure out the rental cost quickly and add it to the time and material costs in repairing the customer's battery. The Record Card shown in Fig. 183 does not help you locate any particular rental battery. For instance, suppose that rental battery No. 896 is out and you wish to know who is using it. You may, of course, look over the "Battery Tags" which are tied to the batteries which are being repaired in the shop, or you may examine the file containing the record cards, but this would take too much time. But if you refer to the rental file you can determine immediately where rental battery No. 896 is, since the cards in this file should be arranged numerically. The rack on which rental batteries are placed should have a tag bearing the same number as the rental battery tacked to the shelf below the place provided for the battery. Each rental battery should always be placed in the same place on the shelf. You can then tell at a glance which batteries are out. A good plan, and one which will save space, is to write the number of the rental battery on the customer's claim check, and when repairs on his own battery are completed, to set his battery in the place provided on the rental rack for the rental which he is using. When he comes in for his battery, you can tell at a glance whether his battery is ready by looking at the place where the rental he is using is normally placed on the rental rack. If a battery is there you will know that it is his battery, and that it is ready for him. [Fig. 185 Rental Battery Stock Card] You could, of course, look through the batteries on the "Ready Rack," but this would take more time, since the numbers of the batteries on this rack will always be different, and you would have to look through all the batteries on the "Ready Rack" before you would be able to tell whether any particular battery were ready. By putting a customer's battery in place of the rental he is using, you will have only one place to look at in order to know whether his battery is ready. ======================================================================== CHAPTER 13. BUSINESS METHODS. ----------------- Success in this day and age cannot be attained without a well thought-out plan of action. There is no business which does not demand some sort of system of management. The smallest business must have it, and will go to ruin without it. Hence every battery service station proprietor should see to it that his affairs are systematized -- arranged according to a carefully studied method. Most men look upon "red-tape" with contempt and in the sense of a mere monotonous and meaningless routine, it merits all the contempt poured upon it. Hard, fast and iron-clad rules, which cease to be a means, and become an end, prove a hindrance rather than a help. But an intelligent method, which adapts itself to the needs of the business, is one of the most powerful instruments of business. The battery man who despises it will never do anything well. It does not matter how clever he is, how good a workman he is, how complete his knowledge of batteries, if he attempts to run his business without a plan, he will eventually come to grief. Purchasing Methods. Every battery service station proprietor is eager to build up his business, and improve the character of his trade, because this in turn means that he will be assured of larger sales to a good class of customers. And it is at once evident that there are a number of requirements that affect this question of building up a business, one of the first in importance being that of purchasing. One of the first things with which the battery man is faced is the question of what, where, and in what quantities to purchase. The philosophy of correct purchasing consists in getting the right materials, in proper quantities, at a low price, and with as little cost for the doing of it as possible. The purchasing problem should be a most interesting and important subject to the proprietor of every service station, because the policy pursued with regard to purchasing will not only largely govern the economy of all his expenditures, except rent and payroll, but it will also control his selling policies. Goods are sold, and services rendered only because some one wants to buy. The customer's purchasing problems govern the proprietor's selling problems. To sell properly, it is necessary to meet the requirements of those who buy. Correct purchasing is not merely a matter of "buying." The buying itself has but little to do, after all, with the question of real economy in this part of the business. The proprietor's purchasing policy should not cease when the purchase order is [Fig. 186 Stock Record] made out, but should continue after the goods have been delivered, received and inspected. He should see that they are properly stored, that they are put to the use intended, and that they are used efficiently. This can be accomplished to good advantage by the use of the Stock Record illustrated in Fig. 186. When goods are received, each item should be entered on these Stock Record cards, keeping in mind always that the requirements of a "perpetual" or "going" inventory of this kind are that a separate account be kept with each kind or class of stock, and not alone with each class, but with each grade of each class. For example, if a quantity of batteries were received, it would not suffice to have one card only for the entire quantity, unless they should happen to be all of the same type and make. It should be understood that these cards are a record of all articles coming into stock, and all articles going out of stock in the way of sales or otherwise, with an individual card for each kind, grade, style or size of stock carried on hand. From the purchase invoices covering stock received, an entry is made in the column headed "Received", to the proper account, showing date, order number, quantity and price. Each sales tag is used to make the entries in the columns headed "Disbursed", in which the date, tag number, quantity, price, and the balance quantity on hand are shown. If this is done daily, for all the sales tags of the particular day, and the cards on which the "disbursed" entries were made are kept separate from the balance of the cards, it is an easy matter to arrive at the cost of all sales for each day, The advantage of having this daily information will be explained and illustrated in following paragraphs. The Use and Abuse of Credit. The question of the proper use of credit is closely allied with the purchasing of goods. A great many business failures can be traced directly to overexpanded credit. Any battery service station proprietor who does not place a voluntary limit on the amount of credit for which he asks is, to say the least, running a very great business risk. The moment he expands his credit to the limit, he leaves himself with no margin of safety, and a sudden change in business conditions may place him in a serious situation. Commercial agencies usually call this condition a lack of capital. The real cause, however, is not so much lack of capital as it is too much business on credit. This does not mean that credit should not be sought; or that all business should be done on the capital actually invested in the concern. Credit is necessary to commercial life. Very few business concerns are so strong financially as to be able to do without credit. Credit should be sought and used intelligently, and it is not a hard matter for any battery service station proprietor to keep his credit good. All that is necessary is to take a few precautions, and observe in general the principles of good business. The first requisite, of course, is to accept no more credit than the business will stand. Sometimes it is possible to secure enough credit to ruin a business. Its present condition and future prospects may appear so good as to warrant securing all the credit possible under the circumstances. It requires courage to limit the growth and the temporary prosperity of a business by keeping down the credit accepted. It is very hard to refuse business. It is difficult not to make extensions when there is enough business in sight to pay for the extensions. But the acid test of whether or not you should extend and borrow is not the amount of business that can be done, but the amount of money that can be spared. The mere fact that you have the money or can get it does not in the least mean that it should be spent. And the reason for this is that, in order to keep your credit good, you must meet all obligations promptly. Nothing has a more chilling effect on any business than failure to meet all indebtedness when due. As soon as additional time is requested in which to meet obligations, your credit rating begins to contract; and if, at the same time, your credit has been overexpanded the business is placed in a most difficult position. More than one concern has gone to the wall when faced with this combination. Proper Bookkeeping Records. The principal difficulty in this matter of the proper use of credit will lie in poor bookkeeping records, making it impossible for the proprietor to know very much about his financial position or operating condition day by day and week by week and month by month. Many service station proprietors figure what they owe once a year only, when they inventory, and many do not keep a permanent record even then; and usually those who are neglectful in this regard are the ones who owe the most, proportionately, who do not take their discounts, and who do not progress. The following table covers the average discounts allowed in various lines. If you study it, and find out how much it costs you to lose discounts, you will at once realize the necessity for the proper sort of bookkeeping records. 1. 1% cash, 30 days net . . . . . . . . . . . . . . . . . . 12% per year 2. 2% cash, 30 days net . . . . . . . . . . . . . . . . . . 24% per year 3. 3% cash, 30 days net . . . . . . . . . . . . . . . . . . 36% per year 4. 5% cash, 30 days net . . . . . . . . . . . . . . . . . . 60% per year 5. 8% cash, 30 days net . . . . . . . . . . . . . . . . . . 96% per year 6. 1% 10 days, 30 days net. . . . . . . . . . . . . . . . . 18% per year 7. 2% 10 days, 30 days net. . . . . . . . . . . . . . . . . 36% per year 8. 3% 10 days, 30 days net. . . . . . . . . . . . . . . . . 54% per year 9. 5% 10 days, 30 days net. . . . . . . . . . . . . . . . . 90% per year 10. 8% 10 days, 30 days net. . . . . . . . . . . . . . . . 144% per year 11. 1% 10 days, 60 days net. . . . . . . . . . . . . . . . 14.4% per year 12. 2% 10 days, 60 days net. . . . . . . . . . . . . . . . 28.8% per year 13. 3% 10 days, 60 days net. . . . . . . . . . . . . . . . 43.2% per year 14. 5% 10 days, 60 days net. . . . . . . . . . . . . . . . 72% per year 15. 8% 10 days, 60 days net. . . . . . . . . . . . . . . . 115.2% per year Then there is the matter of expenses; rent, wages, insurances, taxes, depreciation, freight and express, and all the other miscellaneous items that go to make up the total of your cost of doing business. Expenses eat up a business unless controlled. They ought to be so analyzed that you are able to place your finger on items which appear too large, or uncalled for, or which need explanation. A Daily Exhibit of Your Business. In order to accomplish this, you ought to keep a record similar to that shown by Fig. 187--a Daily Exhibit of your business. The advantage of this record is that it will give any battery man daily information as to the following facts of his business: 1. The amount of stock on hand. 2. The amount of gross profit. 3. The percentage of gross profit. It will give monthly information as to: 1. The expense and percentage of expense. 2. The actual net profit. 3. The percentage of net profit. Such information will help you to locate exactly when and where your losses come; during what months and from what causes. It will enable you to turn losing months this year into profitable months next year; to tell whether your losses were due to a too great expense account, or to too low gross profits. The percentage columns on the sheet are the most important, because only by percentages can you make proper comparisons, and know just how your business is headed. You cannot guess percentages; you must have a way of knowing continually what they are, in order to be certain of getting the right return on your investment. [Fig. 187a "Daily Exhibit" form] [Fig. 187b "Daily Exhibit" form, continued] In analyzing this Daily Exhibit, you will note that it is ruled for five weeks and two extra days, in order to provide for any one and all months of the year. The various columns are provided so that the entries in them will give a clear-cut story of the actual state of your affairs, daily, weekly, and monthly. Each column will be considered in the order in which it appears on the form. First Column--"Merchandise on Hand." In starting this record the first day, the figures entered in this column must be an actual physical inventory of your stock on hand, priced and extended at cost. Do not total this column. Second Column--"New Goods Added to Stock." The figures entered in this column should be the total value of all new goods received from manufacturers or jobbers on the particular day. If you return any articles to the seller immediately upon receipt, and before putting them into your stock, deduct such goods from the invoices and enter only the net amount in this column. This column should be totaled every week and every month. Third Column--"Goods Returned by Customers;--Deduct from Sales." The total value of all goods returned by customers extended at the prices charged customers should be entered in this column daily. Every week and every month this column is totaled. Fourth Column--"Cost of Goods Returned;--Deduct from Cost of Goods Sold." The cost of all goods returned by customers should be entered in this column. The cost prices can always be secured from the Stock Record cards, as previously explained. Total this column every week and every month. Fifth Column--"Goods Returned to Manufacturers." Sometimes there is occasion to return merchandise after it has been put into stock. In such cases, the money value of the articles sent back to manufacturers or jobbers should be entered in this column. This does not mean such goods as were returned on the day received, and were deducted from the seller's invoice, and at no time have appeared in the second column, "New Goods Added to Stock," but only to such merchandise as was originally entered in the second column, and later returned to the manufacturer. This column should be totaled every week and every month. Sixth Column--"Goods Sold, Less Goods Returned." Enter here total of selling prices on sales tags for each day, after deducting amount in the third column. Total this column every week and every month. Seventh Oolumn--"Cost of Goods Sold, Less Cost of Goods Returned." The total of the sales extended at cost prices for each day, minus the amount showing in the fourth column, should be entered in this column. It should be totaled every week and every month. Eighth Column--"Gross Profits." To arrive at the figures to be entered in this column deduct the amount in the seventh column from the amount in the sixth column. Total this column every week and every month. Ninth Column--"Per Cent to Sales." This percentage should be figured every day, and every week and every month, and is arrived at by dividing the figures in the eighth column by the figures in the sixth column. It will pay you to watch this column closely. You will be astonished at the way it varies from day to day, week to week, and month to month. If you watch it closely enough, you will soon learn a great deal more about your business than you ever knew before. You do not need to total this column. Tenth Column--"Accounts Receivable." On the day the Daily Exhibit is first started, the figures for this column must be taken from whatever records you have kept in the past. Do not total this column. Eleventh Column--"Collections." Every day you collect any money from those customers who run charge accounts with you, enter the amount collected in this column. Total it every week and every month. Twelfth Column--"Cash Sales." Every day enter the amount of cash sales in this column, and total it every week and every month. Thirteenth Column--"Charge Sales." The amount of daily sales made to those customers who do not pay cash but run a charge account should be entered in this column. Every week and every month this column should be totaled. General Calculations. To arrive at the amount of "Merchandise on Hand" after the first day, which is, as has been previously explained, an actual physical inventory, add the amounts showing in the first and second columns, and deduct from this total the sum of the fifth and seventh columns. Enter this result in the first column for the next succeeding day. Continue as above throughout the entire month. After the first day the figures in "Accounts Receivable" column are obtained by adding together the amounts showing in the tenth and thirteenth column and deducting from this total the amount in the eleventh column. This balance will be entered in the tenth column for the next day, the same procedure being followed for each day thereafter. "Merchandise on Hand" after the close of business on the last day of the month should be entered in the first column on the line marked "Month Total." This same amount will be carried forward to the first column of next month's sheet and entered on the line of the particular day of the week on which the first of the month falls. Following the "Month Total" are the "Year to Date" and "Last Year to Date." These figures are important for purposes of comparison. Arrive at total for "Year to Date" by adding the total for the present month to the total for "Year to Date" found on the previous month's sheet. The figures for "Last Year to Date" are taken directly from the sheet kept for the same month last year. It is, of course, evident that this cannot be done until one year's records have been completed. Expenses and Profits. Under the heading "Summary" at the bottom of the sheet, provision has been made for finding out how much net profit YOU have made for the month. On the line marked "Gross Profits" enter the "Month Total" figures in the eighth column. Below this enter all the various items of expense as follows: (1) Advertising: By advertising is meant such copy, signs, etc., which may be prepared and used for the purpose of keeping the public informed as to your ability to serve them--in other words, any space which is used for general publicity purposes, such as for instance, your card in the classified telephone directory, or blotters, folders, dodgers which you may have printed up and distributed. Do not load this account with church programs, contributions to the ball team, tickets to the fireman's ball and the like. These are donations, and not advertising. (2) Electricity: All bills for electrical current will be charged to this account. (3) Freight: Charges for all freight and express will be made to this account. (4) Insurance: The total yearly insurance should be divined by twelve, to obtain the amount to be charged to this account monthly. (5) Proprietor's salary: Many battery service station proprietors do not charge their own living as an expense. That's a serious mistake, of course. If those same men should hire a manager to run their service station, the manager's salary would naturally be charged to expense. The amount of money withdrawn from the business by the proprietor should therefore be charged to expense. (6) Rent: The amount of money you pay monthly for rent should be charged to this account. If, on the other hand, you own your own building, charge the business with rent, the same as if you were paying it to someone else. Every business should stand rent; besides, the building itself should show itself a profitable investment. Charge yourself just as much as you would anyone else; don't favor your business by undercharging, nor handicap it by overcharging. (7) Supplies: The cost of all supplies, small tools and miscellaneous articles which are bought for use in the business and not for sale should be charged to this account. (8) Taxes: The yearly amount of taxes paid should be divided by twelve, in order to arrive at the monthly proportion to be charged to this account. (9) Wages: The amount of wages paid to employees should be charged to this account. Care should be taken to determine the actual amount for the month, if wages are paid on a daily or weekly wage rate. (10) Miscellaneous: Any expenses of the business not listed above will be charged to this account. This may include such items as donations, loss on bad accounts, and such like items of expense. You may itemize these into as many headings as you desire, but for the purposes of the Daily Exhibit combine all of them under "Miscellaneous Expense." All these expense items are then added together, and this total is entered on the line marked "Total Expenses." Deduct "Total Expenses" from "Gross Profit" to arrive at "Net Profit." To arrive at the totals for "This Year to Date," carry the figures forward from the previous month's sheet and add figures for present month. The figures for "Last Year to Date" will be found on the sheet for the corresponding month of last year, and are copied in this column. All percentages should be figured on sales. The figures shown on each line in the "Amount" columns under the headings "This Month," "This Year to Date" and "Last Year to Date" should be divided by the "Month Total" of the sixth column, shown above, i. e., "Goods Sold, Less Goods Returned." When you take inventory, the amount of stock should equal "Merchandise on Hand," as shown by the Daily Exhibit. But there will generally be a discrepancy, varying with the size of your stock, and that discrepancy will represent the amount of goods gone out of your station without being paid for; sold for cash and not accounted for; sold on credit and not charged, and the like. It's worth something to know exactly what this amounts to. The place for this information is under "Inventory Variations" on the sheet. The space headed "Accounts Payable" is provided for recording, on the last day of every month, just what you owe for accounts and for notes, and also the same information for the corresponding date of last year. Invaluable Monthly Comparative Information. You see now that by the use of the Daily Exhibit you have a running history of your business by days, weeks and months. But this is hardly sufficient for a clear view of your business, since you will want some record which will tell you what the year's business has been, and how it varied from month to month. [Fig. 188. Statistical and Comparative Record] This is provided for in the Statistical and Comparative Record, illustrated by Fig. 188, on which the amount of sales, cost of sales, gross profit, expenses and net profit are entered for each month of the year. All the figures for entry in this record are taken directly from the Daily Exhibit at the end of the month, which makes the work of compiling it a very easy task. The advantages of a record of this kind can hardly be overstated. The figures in the upper part of this statement will show which months have been profit payers and which have not, while from the figures in the lower part of the report you are able to determine the percentage any group of expenses bears to sales, and are thus in position to subsequently control such items. Do not let the fear of doing a little bookkeeping work prevent you from keeping these records. They should go a long way toward solving the problems which the average proprietor faces today: 1. Selling his goods and services without a profit. 2. Failure to show sufficient net profit at the end of the year. 3. Constantly increasing cost of doing business. You may think at first glance that it will require a great deal of extra work to keep these records, but in this you are mistaken. They are very simple and easy to operate. The American Bureau of Engineering, Inc., will advise you where to obtain these forms. ======================================================================= CHAPTER 14. WHAT'S WRONG WITH THE BATTERY? ------------------------------ When a man does not feel well, he visits a doctor. When he has trouble on his car, he takes the car to a service station. What connection is there between these two cases? None whatever, you may say. And yet in each instance the man is seeking service. The term "Service Station" generally suggests a place where automobile troubles are taken care of. That does not mean, however, that the term may not be used in other lines of business. The doctor's office is just as much a "Service Station" as the automobile repair shop. The one is a "Health Service Station" and the other is an "Automobile Service Station." The business of each is to eliminate trouble. The battery repairman may think that he cannot learn anything from a doctor which will be of any use to his battery business, but, as a matter of fact, the battery man can learn much that is valuable from the doctor's methods of handling trouble. The doctor greets a patient courteously and always waits for him to tell what his symptoms are. He then examines the patient, asking questions based on what the patient tells him, to bring out certain points which will help in making an accurate diagnosis. Very often such questioning will enable the doctor to determine just what the nature of the illness is. But he does not then proceed to write out a prescription without making an examination. If he did, the whole case might just as well have been handled over the telephone. No competent physician will treat patients from a distance. Neither will he write out a prescription without making a physical examination of the patient. The questioning of the patient and the physical examination always go together, some questions being asked before an examination is made to give an approximate idea of what is wrong and some during the examination to aid the doctor in making an accurate diagnosis. The patient expects a doctor to listen to his description of the symptoms and to be guided by them in the subsequent examination, but not to arrive at a conclusion entirely by the description of the symptoms. A patient very often misinterprets his pains and aches, and tells the doctor that he has a certain ailment. Yet the doctor makes his examination and determines what the trouble is, and frequently find a condition which is entirely different from what the patient suspected. He then prescribes a treatment based on his own conclusions and not on what the patient believes to be wrong. Calling for Batteries. A doctor treats many patients in his office, but also makes his daily calls on others. Similarly, the battery repairman should have a service truck for use in calling for customers' batteries, especially where competition is keen. Some car owners cannot bring their cars to the repair shop during working hours, and yet if they knew that they could have their battery called for and have a rental battery installed, they would undoubtedly have their battery tested and repaired more frequently. In some instances a battery will be so badly run down that the car cannot be started, and the car is allowed to stand idle because the owner does not care to remove his battery, carry it to a service station and carry a rental battery with him. Batteries are heavy and generally dirty and wet with acid, and few people wish to run the risk of ruining their clothes by carrying the battery to a shop. The wise battery mail will not overlook the business possibilities offered by the call for and deliver service, especially when business is slow. A Ford roadster with a short express body will furnish this service, or any old chassis may be fitted up for it at a moderate cost. Of course, you must advertise this service. Do not wait for car owners to ask whether you will call for their batteries. Many of them may not think of telephoning for such service, and even if they do, they might call up some other service station. When Batteries Come In What does a man expect when he brings his battery to the battery service-station? Obviously lie expects to be greeted courteously and to be permitted to tell the symptoms of trouble which he has observed. He furthermore expects the repairman to examine and test the battery carefully before deciding what repairs are necessary and not to tell him that he needs new positives, new separators, or an entirely new battery without even looking at the battery. When a car is brought to your shop, you are the doctor. Sonic part of the mechanism is in trouble, and it is your duty to put yourself in charge of the situation. Listen to what the customer hp to say. He has certainly noticed that something is wrong, or he would not have come to you. Ask him what he has observed. He has been driving the car, starting the engine, and turning on the lights, and certainly has noticed whether everything has been operating as it should. The things he has noticed were caused by the trouble which exists. He may not know what sort of trouble they indicate, but you, as the battery doctor can generally make a fairly accurate estimate of what the trouble is. You should, of course, do more than merely listen to what the customer says. You can question him as to how the car has been used, just as the doctor, after listening to what a patient has to say, asks questions to give him a clue to what has caused such symptoms. The purpose of the preliminary questioning and examination is not merely to make an accurate diagnosis of the troubles, but to establish a feeling of confidence on the part of the customer. A man who owns a car generally possesses an average amount of intelligence and likes to have it recognized and respected. Your questioning and examination will either show the customer that you know your business and know what should be done, or it will convince him that you are merely putting up a bluff to hide your ignorance. What the customer wants to know is how much the repairs will cost, and how soon lie may have his battery again. Estimate carefully what the work, will cost, and tell him. If a considerable amount of work is required and you cannot estimate how much time and material will be needed, tell the customer that you will let him know the approximate cost later, when you have gone far enough with the work to be able to make an estimate. If you find that the battery should be taken off, take it off without any loss of time and put on a rental battery. If there is something wrong outside of the battery, however, it will be necessary to eliminate the trouble before the car leaves the shop, otherwise the same battery trouble will occur again. If there is no actual trouble outside the battery, and if the driving conditions have been such that the battery is not charged sufficiently while on the car, no actual repairs are necessary on the electrical system. The customer should be advised to drive in about every two weeks to have his battery tested, and occasionally taken off and given a bench charge. It is better to do this than to increase the charging rate to a value which might damage the generator or battery. Adopt a standard method of procedure in meeting, a customer and in determining what is wrong and what should be done. If the customer is one who brings his car in regularly to have the battery filled and tested, you will: be able to detect any trouble as soon as it occurs, and will be able to eliminate it before the battery is seriously damaged. A change in the charging rate, cleaning of the generator commutator or cutout contact points, if done in time, will often keep everything in good shape. With a new customer who has had his battery for sometime, you must, however, ask questions and make tests to determine what is wrong. Before sending the customer away with a new, rental, or repaired battery, test the electrical system as described on page 276. The most important transaction and one which will save you considerable argument and trouble is to get everything down in black and white. Always try to have the customer wait while you test the battery. If you find it necessary to open the battery do this in his presence. When he leaves there should be no question as to what he shall have to pay for. If more time is required to determine the necessary work, do not actually do the work without getting in touch with the owner and making a written agreement as to what is to be done and how much the cost will be. The Service Record shown in Fig. 183 may be used for this purpose. The following method of procedure is suggested as a standard. Follow it closely if possible, though in some cases, where the nature of the trouble is plainly evident, this will not be necessary any more than a doctor who sees blood streaming from a severe cut needs to question the patient to find out what is wrong. It may not always be necessary to ask all the questions which follow, or to ask them in the order given, but they cover points which the repairman should know in order to work intelligently. Some of the information called for in the questions may often be obtained without questioning the customer. Do not, however, hesitate to ask any and all questions covering points which you wish to know. 1. Greet the customer with a smile. Your manner and appearance are of great importance. Be polite and pleasant. Do not lose your temper, no matter how much cause the customer gives you to do so. A calm, courteous manner will generally cool the anger of an irate customer and make it possible to gain his confidence and good will. Do not argue with your customers, Your business is to get the job and do it in an agreeable manner. If you make mistakes admit it and your customer will come again. Keep your clothes neat and clean and have your face and hands clean. Remember that the first glimpse the customer has of the man who approaches him will influence him to a very considerable extent in giving you his business or going elsewhere. Do not have a customer wait around a long time before he receives any attention. If he grows impatient because nobody notices him when he comes in, it will be hard to gain his confidence, no matter how well you may afterwards do the work. 2. What's the Trouble? Let the customer tell you his story. While listening, try to get an idea of what may be wrong. When he has given you all the information he can, question him so that you will be able to get a better idea of what is wrong. (a) How long have you had the battery? See page 242. (b) Was it a new battery when you bought it? (c) How often has water been added? (d) Has distilled water been used exclusively, or has faucet, well, or river water ever been used? Impure water may introduce substances which will damage or even ruin a battery. (e) Has too much water been added? If this is done, the electrolyte will flood the tops of the jars and may rot the upper parts of the wooden case. (f) How fast is car generally driven? The speed should average 15 M. P. H. or more to keep battery charged. (g) How long must engine be cranked before it starts? This should not require more than about 10 seconds. If customer is in doubt, start the engine to find out. If starting motor cranks engine at a fair speed, engine should start within 10 seconds. If starting motor cranks engine at a low speed, a longer cranking time may be required. The low cranking speed may be due to a run-down or defective battery, to trouble in the starting motor or starting circuit, or to a stiff engine. To determine if battery is at fault, see "Battery Tests," below. (h) Has the car been used regularly, or has it been standing idle for any length of time? An idle battery discharges itself and often becomes damaged. If car has been standing idle in cold weather, the battery has probably been frozen. (i) Has it been necessary to remove the battery occasionally for a bench charge? (j) Has battery ever been repaired? See page 322. Battery Tests 1. Remove the vent plugs and inspect electrolyte. If the electrolyte covers the plates and separators to a sufficient depth, measure the specific gravity of the electrolyte. If the electrolyte is below the tops of the plates and separators, see following section No. 2. If all cells read 1.150 or less, remove the battery and give it a bench charge. If the specific gravity readings of all cells are between 1.150 and 1.200, and if no serious troubles have been found up to this point, advise the owner to use his lights and starting motor as little as possible until the gravity rises to 1.280-1.300. If this is not satisfactory to him, remove the battery and give it a bench charge. If the specific gravity readings are all above 1.200, or if the gravity reading of one cell is 50 points (such as the difference between 1.200 and 1.250, which is 50 "points") lower or higher than the others (no matter what the actual gravity readings may be), make the 15 seconds high rate discharge test on the battery. See page 266. If this test indicates that the internal condition of the battery is bad, the battery should be removed from the car and opened for inspection. If the test indicates that the internal condition of the battery is good, the specific gravity of the electrolyte needs adjusting. The difference in specific gravity readings in the cells is due to one of the following, causes: (a) Water added to the cell or cells which have low gravity to replace electrolyte which had been spilled or lost in some other manner. (b) Electrolyte added to the cell or cells which have high gravity to replace the water which naturally evaporates from the electrolyte. (c) Trouble inside the cell or cells which have low gravity. The high rate discharge test will show whether there is any internal trouble. If any cell shows a gravity above 1.300, remove the battery, dump out all the electrolyte, fill battery with distilled water and put the battery on charge. If the gravity of one or more cells is 50 points less than the others, water has been used to replace electrolyte which has been spilled or lost in some other manner, or else one or more jars are cracked. A battery with one or more cracked jars usually has the bottom parts of its wooden case rotted by the electrolyte which leaks from the jar. If you are not certain whether the battery has one or more cracked jars, see that the electrolyte covers the plates in all the cells one-half inch or so, and then let the battery stand. If the electrolyte sinks below the tops of the plates in one or more cells within twenty-four hours, those cells have leaky jars and the battery must be opened, and new jars put in. If the low gravity is not caused by leaky jars, give the battery a bench charge and adjust the level of the electrolyte. 2. If you found electrolyte to be below tops of plates in all the cells, the battery has been neglected, or there mail be leaky jars. Add distilled water until the electrolyte covers the plates to a depth of about one-half inch. (a) If it requires only a small amount of water to bring up the level of the electrolyte, remove the battery and give it a bench charge. See page 198. Only a brief charge may be necessary. Ask the driver when water was added last. If more than 1 month has passed since the last filling, the upper parts of the plates may be sulphated, and the battery should be charged at a low rate. (b) If it requires a considerable amount of water to bring up the level of the electrolyte, and the bottom of the wooden battery case shows no signs of being rotted, the battery has been neglected and has been dry for a long time, and the plates are mostly likely badly damaged. Open the battery for inspection. (c) If only one cell requires a considerable amount of water to bring up the level of its electrolyte, and the bottom of the wooden battery ease shows no sign of being rotted, that cell is probably "dead," due to in internal short-circuit. To test for "dead" cells, turn on the lamps and measure the voltage of each cell. A dead cell will not give any voltage on test, may give a reversed voltage reading, or at the most will give a very low voltage. A battery with a dead cell should be opened for inspection. (d) If the bottom part of the wooden battery case is rotted, and a considerable amount of water had to be added to any or all cells to bring up the level of the electrolyte, the battery has leaky jars and must be opened to have the leaky jars replaced by good ones. If there is any doubt in your mind as to whether any or all jars are leaking, fill the cells with distilled water and let the battery stand for twelve to twenty-four hours. If at or before the end of that time the electrolyte has, fallen below the tops of the plates in any or all cells, these cells have leaky Jars and the battery must be opened and the leaky jars replaced with good ones. The electrolyte which leaks out will wet the bench or on which the battery is placed and this is another indication of a leaky jar. General Inspection In addition to the tests which have been described, a general inspection as outlined below will often be a great help in deciding what must be done. 1. Is battery loose? A battery which is not held down firmly may have broken jars, cracked sealing compound around posts or between posts and separators, and active material shaken out of the grids. There may also be corrosion at the terminals. 2. Are cables loose? This will cause battery to be in a run down condition and cause failure to crank engine. 3. Is there corrosion at the terminals? This will cause battery to be in a run-down condition and cause failure to start engine. Corrosion is caused by electrolyte attacking terminals. A coating of vaseline on the terminals prevents corrosion. 4. Is top of battery wet? This may be due to addition of too much water, overheating of battery, cracks around posts and between posts and cover, electrolyte thrown out of vents because of battery being loose, or electrolyte or water spilled on battery. Such a condition causes battery to run down. 5. Is top of case acid soaked? This is caused by leaks around posts or between covers and jars, flooding of electrolyte due to overheating or due to addition of too much water, or by electrolyte spilled on covers. 6. Is lower part of case acid soaked? This is caused by leaky jars. 7. Are ends of case bulged out? This may be due to battery having been frozen. This general inspection of the battery can be made in a few seconds, and often shows what the condition of the battery is. Operation Tests Two simple tests may be made which will help considerably in the diagnosis. Turn on the lights. If they burn dim, battery is run down (and may be defective) and battery needs bench charge or repairs. If they burn bright battery is probably in a good condition. With the lights burning, have the customer or a helper step on the starting switch. If the lights now become very dim, the battery is run down (and may also be defective), or else the starting motor is drawing too much current from the battery. Trouble Charts For the convenience of the repairman, the battery troubles which may be found when a car is brought in, are summarized in the following tables: All Cells Show Low Gravity or Low Voltage A. Look for the following conditions: 1. Loose or dirty terminals or cell connectors. This may reduce charging rate, or open charging circuit entirely. Remedy: Tighten and clean connections. 2. Corrosion on terminals or cell connectors caused by acid on top of battery due to over-filling, flooding, defective sealing, lead scraped from lead-coated terminals, and copper wires attached directly to battery. A badly corroded battery terminal may cause the generator, ignition coil, and lamps to burn out because of the high resistance which the corroded terminal causes in the charging line. It may reduce charging rate, or open charging circuit entirely. Remedy: Remove cause of corrosion. Clean corroded parts and give coating of vaseline. 3. Broken terminals or cell connectors. These may reduce charging rate or open charging circuit entirely. Remedy: Install new parts. 4. Generator not charging. Remedy: Find and remove cause of generator not charging (see page 284). 5. Charging rate too low. Remedy: If due to generator trouble, repair generator. If due to incorrect generator setting change setting. If due to driving conditions increase charging rate. 6. Acid or moisture on top of battery due to defective sealing, flooding, spilling electrolyte in taking gravity readings, loose vent plugs. This causes corrosion and current leakage. Remedy: Find and remove cause. 7. Tools or wires on battery causing short-circuits. Remedy: Tell customer to keep such things off the battery. 8. Short-circuits or grounds in wiring. Remedy: Repair wiring. 9. Cutout relay closing late, resulting in battery not being charged at ordinary driving speeds. Remedy: Check action of cutout. See page 282. 10. Excessive lighting current, due to too many or too large lamps. Remedy: Check by turning on all lamps while engine is running. Ammeter should show three to five amperes charge with lamps burning. In winter the charging rate may have to be increased. B. Question Driver as to following causes of low gravity and low voltage: 1. Has water been added regularly? 2. Has impure water, such as faucet, well, or river water ever been added to battery? 3. Has too much water been added? 4. Has electrolyte been spilled and replaced by water? 5. Has battery been idle, or stored without regular charging? 6. Is car used more at night than in daytime? Considerable night driving may prevent battery from being fully charged. 7. Is starter used frequently? 8. What is average driving speed? Should be over 15 M. P. 11. 9. How long is engine usually cranked before starting-? Cranking period should not exceed 10 seconds. C. If battery has been repaired. The trouble may be due to: 1. Improperly treated separators used. 2. Grooved side of separators put against negatives instead of positives. 3. Separator left out. 4. Cracked separator. 5. Positives used which should have been discarded. 6. Bulged, swollen negatives used. 7. Poor joints due to improper lead-burning. D. Battery Troubles which may exist: 1. Sulfated plates. 2. Buckled Plates. 3. Internal Short-circuits. 4. Cracked Jars. 5. Clogged Separators. Gravity Readings Unequal 1. Acid or moisture on top of battery, due to defective sealing, flooding, spilling electrolyte, loose vent plugs. This causes current leakage. Remedy: Find and remove cause. 2. Tools or wires on battery, causing short-circuits. Remedy: Tell driver to keep such things off the battery. 3. Electrolyte or acid added to cells giving the high gravity readings. 4. Electrolyte spilled and replaced by water in cells giving low readings. 5. Grooved side of separators placed against negatives in cells giving the low readings. 6. Separator left out, cracked separator used, hole worn through separator by buckled plate or swollen negatives, or separators in some cells and new ones in others. 7. Old plates used in some cells and new ones in others. 8. Impurities in cells showing low gravity. 9. Shorted cell, due to plates cutting through separators. 10. Cracked jar. 11. Oil some of the older cars a three wire lighting system was used. If the lights are arranged so that more are connected between one of the outside wires and the center, than between the other outside wire and the center, the cells carrying the heavier lighting load will show low gravity. 12. On some of the older cars, the battery is made of two or more sections which are connected in series for starting and in parallel for charging. Oil such cars the cells in one of the sections may show lower gravity than other cells due to longer connecting cables, poor connections, corroded terminals, and so on. Such a condition AN-ill often be found in the old two section Maxwell batteries used previous to 1918. High Gravity This is a condition in which the hydrometer readings would indicate that a battery is almost or fully-charged, but the battery may fail to operate the starting motor. If the lights are burning while the starting switch is closed, they will become very dim. The gravity readings may be found to be above 1.300. The probable causes of this condition are: 1. Electrolyte or concentrated acid added instead of water. 2. One of the numerous "dope" solutions which have been advertised extensively within the past two years. Never use them. If customer admits having used such a "dope" warn him not to do so again. Low Electrolyte Probable Causes: 1. Water not added. 2. Electrolyte replaced in wrong cell after taking gravity readings. 3. Cracked jars. 4. Battery overcharged, causing loss of water by overheating and excessive gassing. Probable Results: 1. Sulfated Plates. 2. Carbonized, dry, cracked separators. 3. Considerable shedding. Battery Overheats Probable Causes: 1. Water not added regularly. 2. Impure water used. 3. Impure acid used. 4. Battery on hot place on car. 5. Alcohol or other anti-freeze preparation added. 6. Excessive charging rate. 7. Improperly treated separators. 8. Battery over-charged by long daylight runs. Probable Results: 1. Sulfated Plates. 2. Burned, Carbonized Separators. 3. Buckled Plates. 4. Excessive Shedding. Electrolyte Leaking Out at Top Probable Causes: 1. Too much water added. 2. Battery loose in box. 3. Cracks in sealing compound due to poor sealing, or cables pulling on terminals, or due to poor quality of sealing compound, or good quality compound which has been burned. 4. Vent plugs loose. Probable Results: 1. Upper portion of case rotted by acid. 2. Electrolyte low. 3. Plates sulphated. 4. Upper parts of separators dry. Summary 1. When May a Battery Be Left on the Car? (a) When you find that the specific gravity of all cells is more than 1.150, the voltage of each cell is at least 2, the voltage doe's not drop when the lights are turned on, or the lights do not become very dim when the engine is cranked with the starting motor, there are no loose terminals or connectors, the sealing compound is not broken or cracked so as to cause a "slopper," the electrolyte covers the plates, the box is not rotted by acid, and there are no broken jars. These conditions will exist only if battery has been well taken care of, and some trouble has suddenly and recently arisen, such as caused by a break in one of the battery cables, loosening of a cable connection at the battery or in the line to the starting motor. 2. When Should a Battery Be Removed From Car? (a) When you find broken sealing compound, causing the battery to be a "slopper." (b) When you find inter-cell connectors and terminals loose, corroded, or poorly burned on. (c) When you find box badly rotted by acid, or otherwise defective. (d) When you find a cracked jar, indicated by lower part of case being acid soaked, or by low electrolyte, or find that electrolyte level falls below the tops of the plates soon after adding water. (e) When you find a dead cell, indicated by very low or no voltage, even on open circuit. (f) When specific gravity of electrolyte is less than 1.150, or gravity readings of cells vary considerably. (g) When battery voltage drops to about 1.7 or less per cell when lamps are turned on, or lamps become very dim when the starting motor is cranking the engine, or the high rate discharge test shows that there is trouble in the cells. (h) When you find that electrolyte is below tops of plates, and it requires considerable water to bring it up to the correct height. (i) When battery overheats on charge, or discharge, although battery is not located in hot place, charging rate is not too high and lamps and accessories load is normal. (j) When battery is more than a year old and action is not satisfactory. (k) When a blacksmith, tinsmith or plumber has tried his hand at rebuilding the battery. Such a battery is shown in Fig. 189. (1) When ends of care are bulged out. 3. When Is It Unnecessary to Open a Battery? (a) When the only trouble is broken sealing compound. The battery should be resealed. (b) When loose, corroded, or poorly burned on terminals and connectors have merely resulted in keeping battery only partly charged and no internal troubles exist. The remedy is to drill off the connectors, or terminals, and re-burn them. (c) When the external condition of battery is good, and a bench charge, see page 198 (with several charge and discharge cycles if necessary) puts battery in a good condition, as indicated by voltage, cadmium, and 20 minute high rate discharge test. 4. When Must a Battery Be Opened? (a) When prolonged charging (72 hours or more) will not cause gravity or voltage to rise. Such trouble is due to defective plates and separators. (b) When battery case is badly acid soaked. A slightly acid soaked case need not be discarded, but if the damage caused by the acid has been excessive, a new case is needed. Plates may also be damaged. (c) When one or more jars are cracked. New jars are needed. The plates may also be damaged. (d) When one or more cells are "dead," as indicated by little or no voltage, even on open circuit. New plates (positives at least) may be required. (e) When battery is more than a year old and action is unsatisfactory. (Battery will not hold its charge.) Battery may have to be junked, or new separators may be required. Every battery should be reinsulated at least once during its lifetime. (f) When a blacksmith, tinsmith, or plumber have tried to repair a case, Fig. 189. [Fig. 189. A Blacksmith and Tinsmith Tried Their Hands on This Case, Lower Part Enclosed in Tin, Strap Iron, Covered with Friction Tape, Around The Top] (g) When the ends of case are bulged. A new case is needed. If the battery has been frozen it should generally be junked. There are some cases on record of a frozen battery having been thawed out and put in serviceable condition by a long charge at a low rate followed by several cycles of discharge and recharge. Generally, at least, a new case, jars, and positives are required. NOTE: New separators should always be installed, whenever a battery is opened for repairs, unless the separators already in the battery are new, and the trouble for which the battery was opened consists of a leaky jar, a separator left out, or some other trouble which does not require pulling the plates out of mesh. ==================================================================== CHAPTER 15. REBUILDING THE BATTERY. ----------------------- How to Open a Battery [Fig. 190 Battery to be opened] A battery is open when its plates have been drawn out of the hard rubber jars. All parts are then exposed, and accessible for inspection and repairs. In an assembled battery, the top of each cell is closed by a hard rubber cover. Leakproof joints are made between these covers and the rubber jars and the wooden case by means of sealing compound which is poured in place while in a molten condition, and joins the covers to the jars and which hardens as it cools. The joints between the covers and the posts which project through the covers are in many batteries made with sealing compound. The cells are then connected to each other by means of the cell connectors, also called "top-connectors," or simply "connectors." These connectors are joined to the lead posts, to which are connected the plate groups by fusing with a flame, and melting in additional lead to make a joint. In opening a battery, we must first disconnect the cells from each other, and then open the joint made by the sealing compound between the covers and the jars and case. The plates may then be lifted out of the jars, and the battery is open. The steps necessary to open a battery follow, in the order in which they must be taken. 1. Clean the Battery. Set the battery on the tear down rack. See that the vent plugs are all tight in place. Then clean the outside of the battery. Remove the greater part of the dirt with a brush, old whisk-broom, or a putty knife. Then put the battery in the water, using a stiff bristled brush to remove whatever dirt was not removed in the first place. A four-inch paint brush is satisfactory for this work, and will last a year or more if taken care of. If water will not remove all the dirt, try a rag wet with gasoline. 2. Drilling Off the Connectors and Terminals. When you have cleaned the outside of the battery as thoroughly as possible, set the battery on the floor near your work bench. Make a sketch of the top of the battery, showing the exact arrangement of the terminals and connectors. This sketch should be made on the tag which is tied to the battery. Tic this tag on the handle near the negative terminal of the battery or tack it to the ease. Then drill down over the Center of the posts. For this you will need a large brace with a heavy chuck, a drill the same size as the post (the part that goes down into the battery), a large screw driver, a center punch, and a hammer. [Fig. 191 Drilling post and cell connector] With the center punch, mark the exact centers of the tops of the posts and connectors. Then drill down about half way through the connectors and terminals until you cut through the part of the connector which is welded to the post. When you can see a seam between the post and connector you have drilled through the welded part. See Figs. 191 and 192. Now pry off the connectors with the screw driver, as shown in Fig. 193. Lay a flat tool such as a chisel or file on the top edge of the ease to avoid damaging the ease when prying off the connectors. If any connector is still tight, and you cannot pry it off with a reasonable effort, drill down a little deeper, and it will come off easily, provided that the hole which you are drilling is exactly over the center of the post and as large as the post. There are five things to remember in drilling the connectors and posts: [Fig. 192 Connector drilled to correct depth] (a) Be sure that the hole is exactly over the center of the post. (b) Do not drill too deep. Make each hole just deep enough so that the connector will come off easily. Fig. 192 shows a cross section of a post and connector drilled to the proper depth. Notice that you need not drill down the whole depth of the connector, because the bottom part is not burned to the post. (c) Be sure that the drill makes the right sized hole to permit the connectors and terminals to be removed easily when drilled half way through. An electric drill will do the work much faster than a hand brace. (d) Protect the edge of the battery box when you pry up the connectors with a screw driver. (e) Remove your drill after the hole is well started and see whether the hole is in the center of the post. Should you find that it is off center, tilt the drill, and with the end of the drill pointing the center of the post as you drill, gradually straighten the drill. This will bring the hole over the center of the post. Having removed the connectors, sweep all the lead drillings front the top of the battery into a box kept for lead drillings only. Fig. 194. When this box is full, melt the drillings and pour off in the burning lead mould. [Fig. 193 Prying off cell connector] Post Seal. If the post seal consists of a lead sealing nut, this may be removed now. With some types of batteries (Willard and U. S. L.), drilling the connectors also breaks the post seal. With other batteries, such as the Vesta, Westinghouse, Prest-0-Lite, Universal, it is more difficult to break the post seal. [Fig. 194 Brushing lead drillings into box] On these batteries, therefore, do not break this seal before drawing out the plates. You may find that it will not be necessary to separate the groups, and the post seal will not have to be broken at all, thereby saving yourself considerable time on the overhauling job. 3. Heating Up the Sealing Compound. Having disconnected the cells from each other by removing the cell connectors, the next step is to open the joint made by the sealing compound between the covers and jars. Fig. 195 shows the battery ready for this step. When cold, the compound is a tough substance that sticks to the cover and jar, and hence it must be heated until it is so soft that it is easily removed. There are several methods by means of which compound may be heated. These are as follows: Steam. This is the most popular, and undoubtedly the best means of heating the compound, and in the following instructions it will be assumed that steam has been used. The battery is either placed in a special box in which steam is sent, or else steam is sent directly into each cell through the vent tube. In the first method the compound is heated from the outside, and in the second it is heated from the inside of the cell. [Fig. 195 Battery ready for steaming] [Fig. 196 Drawing up an element] If the battery is placed in the steaming box, about ten minutes will be required for the steam to heat up the sealing compound. For batteries which use but very little compound, less time is required. if steam is sent directly into the cells through the vent tubes, five to seven minutes will generally be enough. The covers must be limp and the 1 compound must be soft before turning off the steam. Hot Water. The electrolyte is poured out of the battery, which is then inverted in a vessel of hot water. This method is slower than the others, and is more expensive because it requires a larger volume of water to be heated. Hot Putty Knife and Screwdriver. The compound may be dug out with a hot putty knife. This is a slow, unsatisfactory method in most instances, especially in those batteries which use a considerable amount of sealing compound. With some batteries using only a small quantity of compound, a heated putty knife may be run around the inside of the jar between the jar and the cover. This will break the joint between the cover and the jar, and allow the plates to be lifted out. The compound is then scraped from covers and inside of jars, heating the knife or screwdriver whenever it cools off. Lead Burning Flame. Any soft lead burning flame may be used. Such a flame may be adjusted to any desired size. Where steam is available, a flame should, however, never be used. The temperature of the flame is very high, and the covers, jars, case, posts, and vent plugs may be burned and made worthless. Even for the expert repairman, a flame is not as satisfactory as steam. The Gasoline Torch. This is the most unsatisfactory method, and should not be used if possible. The torch gives a hot, spreading flame and it is difficult to prevent the covers, jars, case, etc., from being burned. Do not use a gasoline torch if you can possibly avoid doing so. Alcohol torches are open to the same objections, and are not satisfactory, even in the hands of a highly skilled workman. If a flame is used for heating the compound, be sure to blow out with a hand bellows or compressed air any gas that may have gathered above the plates, before you bring the flame near the battery. Electric Heat. Special electric ovens for softening sealing compound are on the market. The heating element is brought close to the top of the battery. Where electric power is cheap, this method may be used. Otherwise it is rather expensive. [Fig. 197 Resting element on jar to drain] When the sealing compound has been softened, place the battery on the floor between your feet. Grasp the two posts of one cell with pliers, and pull straight up with an even, steady pull. If the battery has been steamed long enough, the plates will come up easily, carrying with them the cover (or covers, if the batter has upper and lower covers) to which the compound is sticking, as shown in Fig. 196. Do not remove the plates of the other cells until later. Rest the plates on the top of the jar just long enough to allow most of the acid to drain from them, Fig. 197. If you have removed the post seal, or if the seal consists of compound (old Philadelphia batteries), pry off the covers now with a screw driver. Otherwise, leave the covers in place while cleaning off the compound. While the plates are resting on the jars to drain, scrape the compound from the covers with a warm screw driver or putty knife, Fig. 198. Work quickly while the compound is still hot and soft, and comes off easily. As the compound cools it hardens and sticks to the covers and is removed with difficulty. If the battery has sealing compound around the posts, this should also be removed thoroughly, both from the cover and from the post. When you scrape the compound from the covers, do a good job. Do not scrape off most of it, and then leave pieces of it here and there. Remove every bit of compound, on the tops, edges, sides, and bottoms of the covers. If you need different sized putty knives or screw drivers to do this, use them. The time to remove all the compound is while it is still hot, and not after it has become hard and cold. If the battery has single covers, the compound can be removed very quickly. If the battery is of the old double-cover type, the job will take more time, since all the compound should be scraped from both top and bottom covers, Fig. 199. [Fig. 198 Removing compound from cover] As soon as you have removed the compound from the covers of the first cell, serape away the compound which may be sticking to the top and inside walls of the jar, Fig. 200. Here again you must do a good job, and remove all of this compound. If you do not do it now, you will have to do it when you try to put the plates back into the jar later on, as compound sticking to the inside walls of the jar will make it difficult, and even impossible to lower the plates into the jar. Now draw up the plates of the next cell. Rest the plates on the top of the jar just long enough to drain, and then lift off the covers, and remove all of the compound, from cover, posts, and jar, just as you did in the first cell. The third cell, (and the others, if there are more than three cells) are handled just as you did the first one. Remember that you should lose no time after you have steamed the battery. Hot compound is soft and does not stick to the covers, jars, and posts and may therefore be removed quickly and easily. Cold compound is hard, and sticks to the covers. Draw out the plates of only one cell at a time, and clean the compound from the cover, posts and jar of that one cell before you draw out the plates of the other cells. In this way, the compound on the covers of the other cells will remain hotter than if all the plates of the battery were drawn out of the jars before any of the compound was removed from the covers. You should have all the plates drawn out, and all the compound removed within five minutes after you draw up the plates. [Fig. 199 Removing sealing compound from double cover] Throw away the old compound. If is very likely acid-soaked and not fit for further use. What Must Be Done with the Battery? The battery is now open, and in a condition to be examined and judgment pronounced upon it. The question now arises, "What must be done with it!" In deciding upon this, be honest with your customer, put yourself in his place, and do just what you would like to have him do if he were the repairman and you the car owner. The best battery men occasionally make mistakes in their diagnosis of the battery's condition, and the repairs necessary. Experience is the best teacher in this respect, and you will in time learn to analyze the condition of a battery quickly. Handle every cell of a battery that comes in for repairs in the same way, even though only one dead cell is found, and the others are apparently in good condition. Each cell must be overhauled, for all cells are of the same age, and the active materials are in about the same condition in all the cells, and one cell just happened to give out before the others. If you overhaul only the dead cell, the others cells are quite likely to give out soon after the battery is put into service again. [Fig. 200 Removing compound from top of jar] It is absolutely necessary for you to have a standard method in working on battery plates. You must divide your work into a number of definite steps, and always perform these steps, and in the same order each time. If you have a different method of procedure for every battery, you will never be successful. Without a definite, tangible method of procedure for your work you will be working in the dark, and groping around like a blind man, never becoming a battery expert, never knowing why you did a certain thing, never gaining confidence in yourself. It is impossible to overemphasize the importance of having a standard method of procedure and to stick to that method. Careless, slip-shod methods will please your competitor and give him the business which belongs to you. 1. Examine plates to determine whether they can be used again Rules for determining when to discard or use old plates follow. 2. If all plates of both positive and negative groups are to be discarded, use new groups. The question as to whether the old negatives should be used with new positives has caused considerable discussion. If the negatives are old and granulated, they should of course be discarded. Remember that the capacity of negatives decreases steadily after they are put into service, while the capacity of positives increases. Putting new positives against negatives which are rapidly losing capacity is not advisable. However, trouble often arises in a battery whose negatives still have considerable capacity, and such negatives may safely be used with new positives. If you feel that a battery will not give at least six months more service after rebuilding with the old negatives, put in all new plates, or sell the owner a new battery, allowing him some money on the old battery. But if you really believe that the negatives still have considerable capacity, put in new positives if required. If all new plates are used, proceed as directed in this chapter, beginning at page 348. 3. If you find that only some of the plates are to be discarded, or if you are not certain as to the condition of the plates, eliminate any short circuits which may exist, and give the battery a preliminary charge, as described later, before you do any work on the plates. Plates that are fully charged are in the best possible condition for handling, and you should make it an ironclad rule that if some of the plates can be used again always to charge a battery before you work on the plates, no matter what is to be done to them. If both positives and negatives are to be discarded, the preliminary charge should not, of course, be given, but if only the negatives, or the negatives and some or all of the positives are to be used again, give this preliminary charge. Very few batteries will come to your shop in a charged condition, and an exhausted battery is not in a good condition to be worked on. Charge the whole battery even though only one cell is in a very bad condition. This is a method that has been tried out thoroughly in practice, not in one or two cases, but in thousands. Batteries in all sorts of conditions have been rebuilt by this method, and have always given first class service, a service which was frequently as good, if not better than that given by new batteries. Examining the Plates Place an element on a block of wood as shown in Fig. 201. Carefully pry the plates apart so that you can look down between them and make a fair preliminary examination. Whenever possible, make your examination of the plates without separating the groups or removing the old separators. This should be done because: (a) Very often the active material is bulged or swollen, and if you pull out the old separators and put in new ones before charging, the element spreads out so at the bottom that it cannot be put back into the jars without first pressing in a plate press. Pressing a complete element with the separators in place should never be done if it can possibly be avoided. If it is done the separators should be thrown. away after you have charged the battery, washed and pressed the negatives, and washed the positive. [Fig. 201 Element on block for examination] (b) If you put in new separators before giving the battery the preliminary charge, the new separators may pick up any impurities which may be on the plates, and will probably be cracked by forcing them between the bulged and sulphated plates. If, however, the old separators are covered with sulphate, it is best to throw them away and put in new separators before giving the battery its preliminary charge, because such separators will greatly hinder the flow of the charging current. In batteries using rubber sheets in addition to the wooden separators, remove all the wooden separators and leave the rubber sheets in place between the plates. Where only wooden separators are used in a battery, these may be thrown away and perforated rubber separators used for the preliminary charge. Rubber separators may be used again. See (a) above about precautions against pressing a complete element. [Fig. 202 Separating the groups] If you are not absolutely certain as to the condition of the plates, draw out a few separators. If separators stick to the plates, loosen them by inserting a putty knife blade between them and the plates. Removing a few separators will permit you to separate the groups before removing the rest of the separators. To separate the groups, grasp a post in each hand, as, in Fig. 202, and work them back and forth, being careful not to injure the posts, or break off any plates. With the groups separated, the remaining separators will either fall out or may be easily pushed out with a putty knife. Ordinarily, the groups may be separated in this way if the elements have thirteen plates or less. The natural thing to do at this point is to decide what must be done to the plates, and we therefore give a number of rules to help you determine which are to be junked, and which are to be used again. Study these rules carefully, and have them fixed firmly in your mind so that you can tell instantly what must be done with the plates. [Fig. 203 Positives from frozen vehicle cell, showing active material sticking to separator] When to Put In New Plates 1. If one or more jars are cracked and leak, and positive plates have been ruined by freezing, as shown in Fig. 203, and if upon drawing out the separators, and separating the positive and negative groups the active material drops out of the grids, the only way to put the battery in a good condition is to put in new positives, and new jars and case if necessary. Make a careful estimate of 1. (a) Cost of new jars. 2. (b) Cost of new plates. 3. (c) Cost of new case if needed. 4. (d) Cost of labor required. Try to have the owner present while you are opening his battery. If, however, he could not wait, and has left, call him up and tell him what the total cost will be, and if he has no objections, go ahead with the job. If he is not entirely satisfied with your price, try to get him to come to your shop. Show him the battery, explain its condition, tell him just what must be done with it, and explain how you made your estimate of the cost of the whole job. If you do this. there will never be any misunderstanding as to cost. Tell him the cost of a new battery, and let him decide if lie wants one. If the cost of repairing is almost as much as the price of a new battery. advise him to buy a new one, but allow him to make the decision himself. He will then have no cause for complaint. [Fig. 204 and 205 Show Diseased Negatives. The Large Ones Only Eight Months Old. Active Material, Granulated and Blistered] 2. If the battery is more than two years old, and the active material on the negative plates is granulated (grainy appearance), Figs. 204 and 205, and somewhat disintegrated; if the plates are weak and brittle around the edges, and several grids are cracked, Fig. 206, and the plates have lost a considerable amount of active material; and if the case has been rotted by the acid, the battery should be junked. [Fig. 206 Weak and cracked positives] Call up the owner, and tell him he needs a new battery. If he does not seem pleased, ask him to come to your shop. Then show him his battery, and explain its condition. If you are courteous and patient, you will sell him a new battery. Otherwise he will never return. [Fig. 207 Buckled plates, and Fig. 208 An unusually bad case of buckling] 3. If the positive plates are badly distorted from buckling, as in Figs. 207 and 208 discard them, for they will cut through new separators, if put into commission again, ill from two to six months. 4. A battery which has has been dry and badly sulphated at some past period of its life will have the dry portions covered with a white sulphate, the acid line being clearly distinguishable by this white color, as shown at A and B in Fig. 201. If the plates are otherwise in good shape and you wish to use them, give them the "water cure" described on page 349. [Fig. 209 Corroded, bulged and sulphated negatives. Disintegrated, rotten positives.] [Fig. 210 Disintegrated positives.] 5. Rotten and disintegrated positive plates, Figs. 209 and 210, must be replaced with new plates. The plates have fallen to pieces or break at the slightest pressure. Disintegrated plates are an indication of impurities or overcharging, providing the battery is not old enough to cause disintegration normally,--say about two years. The lead grid is converted into peroxide of lead and becomes soft. As a result, there is nothing to support the paste, and it falls out. Better put in new negatives also. 6. Batteries with high gravity or hot electrolyte have burned and carbonized separators, turning them black and rotting them, the negative paste becomes granulated and is kept in a soft condition, and gradually drops from the grids on account of the jolting of the car on the road. Fig. 211 shows such a battery. 7. Dry, hard, and white, long discharged, and badly sulphated plates, Figs. 201 and 209, are practically ruined, though if the trouble is not of long standing, the plates may be revived somewhat by a long charge at a very low rate, using distilled water in place of the electrolyte, and then discharging at a current equal to about one-eight to one-tenth of the ampere hour capacity of the battery at the discharge board. Charge and discharge a battery a number or times, and you may be able to put a little "pep" into it. In charging sulphated plates, use a low charging rate, and do not allow gassing before the end of the charge, or a temperature of the electrolyte above 110°F. [Fig. 211 Side and end view of element from traveling salesman's battery] 8. If a battery case is not held down firmly, or if the elements are loose in the jars, the plates will jump around when the car is in motion. This will break the sealing compound on top of the battery, and cause the battery to be a slopper. The active materials will be shaken out of the grids, as shown in Fig. 212, and the plates will wear through the separators. New plates are required. 9. If Battery Has Been Reversed. Often the plates of such a battery disintegrate and crumble under the slightest pressure. If the reversal is not too far advanced, the plates may be restored (See page 81), but otherwise they should be discarded. This condition is recognized by the original negatives being brown, and the original positives gray. From the foregoing explanations, you see that most of the trouble is with the positives: (a) Because the positive active material does not stick together well, but drops off, or sheds easily. (b) Because the positives warp or buckle, this causing most of the battery troubles. (c) Because the positive plate is weaker and is ruined by freezing. When the Old Plates May be Used Again 1. If one or more plates are broken from the plate connecting straps, or the joint between any strap and the plate is poorly made. If plates are in good condition, reburn the plate lugs to the straps. [Fig. 212] Fig. 212. Element from a "Slopper." Element was Loose in Jar and Jolting of Car Caused Paste to Fall Out. 2. Straight Rebuild. If the general condition of the battery is good, i.e., the plates straight or only slightly buckled, only a slight amount of shedding of active material, no white sulphate oil either plate, the grids not brittle, active material adhering to and firmly touching the grids, the positive active material of a dark chocolate brown color and fairly hard (as determined by scratching with blade of a pocket knife), the negative active Material dark gray in color and not blistered or granulated, and the plates not too thin, make a straight rebuild. To do this, charge the battery, remove any sediment from the bottom of the jar, wash and press the negatives, wash the positives, clean the parts, insert new separators, and reassemble as directed later. The only trouble may be cracked sealing compound, or a broken jar. Broken jars should, of course, be replaced. [Fig. 213 Badly bulged negatives. Such plates must be pressed] 3. Badly bulged negative plates, Fig. 213, cause lack of capacity because the active material is loose, and does not make good contact with the grids. If the active material is not badly granulated (having a grainy appearance) the plates call be used again. Sulphated negatives have very hard active material, and will feel as bard as stone when scratched with a knife. Hard negatives from Which active material has been falling ill lumps Oil account of being overdischarged after having been in in undercharged condition may be nursed back to life, if too much of the active material has not been lost. 4. The formation of an excessive amount of sulphate may result in cracking the grids, and the active materials falls out in lumps. Such plates may be put in a serviceable condition by a long charge and several cycles of charge and discharge if there is not too much cracking or too much loss of active material. 5. Positives which are only slightly warped or buckled may be used again. 6. When the only trouble found is a slight amount of shedding. Positive active material must be of a dark chocolate brown color and fairly hard. Negatives must be a dark gray. 7. When the plates are in a good condition, but one or more separators have been worn or out through, or a jar is cracked. If the battery is one which will not hold its charge, and plates seem to be in a good condition, the trouble is very likely caused by the separators approaching the breaking down point, and the repair job consists of putting in new separators or "reinsulating" the battery. What To Do With the Separators It is the safest plan to put in new separators whenever a battery is opened, and the groups separated. Separators are the weakest part of the battery, and it is absolutely essential that all their pores be fully opened so as to allow free passing of electrolyte through them. Some of the conditions requiring new separators are: 1. Whenever the pores are closed by any foreign matter whatsoever. Put in new separators whether you can figure out the cause of the trouble or not. The separator shown in Fig. 201 is sulphated clear through above the line B, and is worthless. The separator shown in Fig. 203 should not be used again. 2. When the separators have been cut or "chiseled off" by the edge of a buckled plate, Fig. 214. 3. When a buckling plate or plate with bulged active material breaks through the separator, Fig. 214. [Fig. 214] Fig. 214. Separators Worn Thin and Cut Through on Edges by Buckled Plates. Holes Worn Through by Bulged Active Material, Center One Shows Cell Was Dry Two Thirds of the Way Down. 4. When a battery has been used while the level of the Fig. 214. Separators Worn Thin and Cut Through on Edges by Buckled Plates. Holes Worn Through by Bulged Active Material. Center One Shows Cell Was Dry Two Thirds of the Way Down electrolyte has been below the tops of the plates, or the battery has been used in a discharged condition, and lead sulphate has deposited on the separators, Fig. 201. [Fig. 215 Rotted separators] 5. When a battery has been over-heated by overcharging or other causes, and the hot acid has rotted, burned and carbonized the separators, Fig. 215. 6. When a battery has been damaged by the addition of acid and the separators have been rotted, Fig. 215. 7. Separators which are more than a year old should be replaced by new ones, whether plates are defective or not. When you have put in new separators, and put the battery on charge, the specific gravity of the electrolyte may go down at first, instead of rising. This is because the separators may absorb some of the acid. If the battery was discharged when you put in the new separators, the lowering of the specific gravity might not take place, but in most cases the specific gravity will go down, or not change at all. Find the Cause of Every Trouble The foregoing rules must be studied carefully and be clearly tabulated in your mind to be able to tell what to put into commission again and what to discard as junk. It will take time to learn how to discriminate, but keep at it persistently and persevere, and as you pass judgment on this battery and that battery, ask yourself such questions as: What put this battery in this condition? Why are the negative plates granulated? Why are the positive plates buckled? What caused the positive plates to disintegrate? Why are the separators black? Why is the case rotten when less than a year old? Why did the sealing compound crack on top and cause the electrolyte to slop? Why did one of the terminal connectors get loose and make a slopper? Who is to blame for it, the car manufacturer, the manufacturer of the battery, or the owner of the car? Why did this battery have to be taken off the car, opened up and rebuilt at 5 months old, when the battery taken off a car just the day before had been on for 30 months and never had been charged off the car but once? There is a reason; find it. Locate the cause of the trouble if possible, remove the cause; your customer will appreciate it and tell his friends about it, and this will mean more business for you. Eliminating "Shorts" If you have decided that some or all of the plates may be used again, the next thing to do is to separate any plates that are touching, and put the battery on charge. It may be necessary to put in new separators in place of the defective ones. Examine the separators carefully. Whenever you find the pores of the separators stopped up from any cause whatsoever, put in new separators before charging. 1. Sometimes the negative plates are bulged or blistered badly and have worn clear through the separators, Fig. 214, and touch the positives. In cases of this kind, to save time and trouble, separate the groups, press the negatives lightly, as described later, assemble the element with new separators, and it is ready for charging. 2. There is another case where the groups must be separated and new separators inserted before they will take charge, and that is where the battery has suffered from lack of water and has sulphated clear through the separators, Fig. 201. The separators will be covered with white sulphate. Chemical action is very sluggish in such cases. If you find that the separator pores are still open, leave the separators in place and proceed to separate the plates that are touching. How? That depends on what insulating material you have available that is thin enough. If nothing else is available, take a piece of new dry separator about 3/8 inch to 1/2 inch square, or a piece of pasteboard the same size. Use a screw driver or putty knife to separate the plates far enough to insert the little piece of insulation as in Fig. 216. Free all the shorts in this way, unless you have some old rubber insulators. In this case, break off some narrow strips 3/4 inch wide or less, put two together and repeat the operation as above, using the rubber strips instead of the pieces of separator. Insert down 1/2 inch or so and bend over and break off. Occasionally the Lipper edges of the plates are shorted, in which case they must be treated the same way. [Fig. 216 Clearing short circuits] [Fig. 217 Cleaning scale from posts before replacing connectors temporarily for charge] Charging When you have in this way cleared all the "shorts" in the elements place the elements back in the jars in the same position as they were when you opened the battery, and add enough distilled water to the electrolyte to cover the plates to a depth of one-half inch. If the negatives are badly sulphated (active material very hard), they will charge more quickly if all the old electrolyte is dumped out and the cells filled with distilled water before putting the battery on charge. This "water cure" is the best for sulphated negatives and will save many plates that could otherwise not be used again. Make it a rule to replace the old electrolyte with distilled water if negatives are sulphated. [Fig. 218] Fig. 218. Tapping Connectors in Place. Preparatory to Charging After Battery Has Been Opened and Shorts Removed The next operation is to put the battery on charge. Grasp each post in the jaws of a pair of gas pliers and work the pliers back and forth, Fig. 217, so as to remove the scale and allow the connecting straps to make good contact. Now take a knife and cut off the rough edges left in the connecting straps by the drill. Taper the edge, if necessary to go on post. Turn the connectors upside down and pound gently in position, Fig. 218, to make a good connection. Temporary charging connections may also be made by burning lead strips on the posts. This being properly done, the battery is ready for charging. Check up the connections to be sure they are correct. Now put the battery on charge, and charge at a low rate. Do not allow the temperature of any cell to rise above 110°F. Continue the charge until the electrolyte clears up, and its specific gravity stops rising and the plates have a normal color over their entire surface. Fully charged positive plates have a chocolate brown color, and fully charged negative plates have a dark gray color. By holding an electric light directly over a cell, and looking down, the color of both negatives and positives may be determined. Do not take the battery off charge until you have obtained these results, although it may be necessary to continue the charge for two, three, four, or five days. In this preliminary charge it is not necessary to bring the gravity up to 1.280, because the electrolyte is not to be used again, and the plates will become charged completely, regardless of what the gravity is. The essential thing is to charge until the electrolyte becomes perfectly clear, the gravity stops rising, and the plates have the right color. The Cadmium test may be used here to determine when the plates are charged. If the gravity rises above 1.280 during the preliminary charge, adjust it to 1.280 by drawing out some of the electrolyte and adding distilled water. The battery must stay on charge until you have the desired conditions. If one cell does not charge,--that is, if its specific gravity does not rise,--you have probably not freed all the shorts, and must take the element out of the jar again and carefully inspect it for more shorts. Right here is where one of the most important questions may be asked about rebuilding batteries. Why must you free the shorts and put the battery on charge? Why not save time by putting in all new separators, sealing the battery, burning on the cell connectors, and then putting it on charge? If you have ever treated a battery in this way, what results did you get? Why did you have a badly unbalanced gravity of electrolyte? How could you know what specific gravity electrolyte to put in each cell? Perhaps one was charged, one only half charged, and the other dead. Suppose the dead cell had impurities in it. How could you get rid of them? Suppose the battery showed poor capacity on test, what would you do? Washing and Pressing the Negatives To continue the actual work on the battery. The battery being fully charged,--the electrolyte clear, the plates of normal color, the specific gravity no longer rising,-- remove it from the charging bench and put it on the work bench. Draw each element and let drain as in Fig. 197. [Fig. 219 Nesting plates] Here again the labeled boxes described on page 183 come in handy. Separate one group, remove the separators, and put one group in each end of box to keep clean. Separate another group, And nest the plates, Fig. 219, the negative with the negative, and positive with positive. Separate the third element and put groups in the boxes. Pour the old electrolyte out of the jars, and wash out the jars as described on page 360. You now have the plates in the best possible shape for handling. Take the boxes containing the plates to the sink. Have the plate press and the plate press boards ready for use. If, for any reason, you are called away from your work at this point to be gone for five minutes, do not leave the fully charged negatives exposed to the air, as they will become very hot. Cover them with water. A one-gallon stone or earthenware jar will hold the negative plates of a 100 ampere hour battery if you nest two of the groups. You may also put negatives back in jars from which they were taken, and fill with water. Now hold a negative group under the faucet, and let a strong stream of water run down over each plate so as to wash it thoroughly, and to remove any foreign matter from the plate surfaces. All negative groups must be handled in exactly the same way so as to get the same results in each case. After you have washed the first group, place it on edge on a clean board with the post down and pointing away from you, and the bottom of the group toward you. Now insert plate press boards which are slightly larger than the plates, and of the exact thickness required to fill the spaces between plates, Fig. 113. For the standard 1/8 inch plates, a 5-16 inch board, or two 1/8 inch boards should be placed between plates. The 1/8 inch boards are actually more than 1/8 inch thick, and will give the proper spacing. For thin plates, use 1/4 inch boards. Do not push the plate press boards more than 1/8 inch above the tops of the plates, and be sure that the boards cover the entire plates. Put a board on the outside of each end plate of the group. In this way insert the plate press boards in each of the three negative groups. Then place each negative group on the lower jaw of the plate press with the post of each group pointing toward you. Three groups may be pressed at one time. Bring the top edges of the transite boards flush with the front edge of the lower jaw of the press, so that no pressure will be applied to the plate lugs. See Fig. 114. Pressure applied to the plate lugs will break them off. Now screw down the upper jaw of the press as tightly as you can with the handwheel, so as to put as much pressure on the plates as possible. Leave the plates in the press for about five minutes. Then remove them from the press, take out the boards, and replace the plates in the battery jar from which they were removed, and cover with water. They may also be placed in a stone or earthernware jar and covered with water, especially if there is any work to be done on the jars or case of the battery. If the spongy lead of the negatives is firm, they may be reassembled in the battery as soon as they have been pressed. If, however, the spongy lead is soft and mushy, keep the negatives covered with water for 12 to 24 hours. This will make them hard and firm. Then remove them from the water and dry them in the air. In drying, the plates will become heated and will steam. As soon as you notice any steaming, dip the plates in water until they are cool. Then remove them from the water and continue the drying process. Each time the negatives begin to steam as they dry in the air, dip them in the water until they are cool. When the negatives are dry, they are ready to be reassembled in the battery and prepared for service. Negatives treated in this way will give good service for a much longer time than they would if not treated in this way. The spongy lead has been made firm and elastic. If you have other negatives in your shop which are not in use, treat them in the same way and put them away for future use, to use as rental batteries. Always put them through the same process: 1. Charge them fully. 2. Press them in the plate press to force the spongy lead back into the grids. 3. Soak them in water, if the spongy lead is soft and mushy, for 12 to 24 hours, or even longer until the spongy lead is firm. Dry them in the air, dipping them in water whenever they begin to steam and become heated. This will give you negatives that will give excellent service and have a long life. Many negatives treated in this way will be good for fifteen months to two years of additional service. The rental batteries should be assembled in the same way as those you are rebuilding for the owners. The importance of pressing negatives cannot be exaggerated. Always press the negatives of the batteries which you rebuild. Do not do it to half, or three-fourths of the negatives, but to all of them. The work takes but a few minutes, and the time could not be put to better advantage. The spongy lead of the negatives swells and bulges out and makes very poor contact with the grids as a battery becomes discharged. This results in a loss of capacity, gradual sulphation of the loose active material, corrosion of the grids, failure of the gravity to rise high enough on charge, overheating of the battery on charge, gassing before the sulphate is reduced to active material with breaking off and roughening of the active material, and makes the battery lazy and sluggish in action. The spongy lead must make good contact with the grids if the battery is to have a long life and give good service. No amount of charging will cure a negative with bulged, swollen active material. Once this material becomes bulged nothing but pressing will put it back where it belongs, and until it is pressed back into the grids the plates are in a poor condition for service. Even if the bulging is but very slight, the plates must be pressed. Washing Positives If you intend to use some of the positives, they should now be washed. If you intend to use all new positives, throw away the old ones, of course. The positives should not be held under the faucet as the negatives were, because the stream of water will wash out much of the positive active material. Rinse the positives a number of times in a jar of clean water by moving them up and down in the water. This will remove impurities from the surfaces of the plates and wash off any foreign or loose materials. After rinsing each positive group, replace it in the box. Never attempt to straighten badly buckled positives, as the bending cannot be done successfully, and the active material will not have good contact with the grids. Positives cannot be pressed as negatives can, because the positive active material lacks the elasticity and toughness of the negative spongy lead. Slightly buckled positives may sometimes be straightened by bending them lightly all around the edges with a pair of thin, wide nosed pliers. This should be done very carefully, however, and the straightening done gradually. If the plates cannot be straightened in this way and the separators do not lie perfectly flat against them without pinching at the corners, the plates should be discarded, and new ones used in their place. This is all the work to be done on the old plates, and those which are to be used again are ready to be reassembled in the battery. The process of treating the plates should be followed in every battery that you rebuild, and the same steps should always be taken, and in the same order. With one Standard method of rebuilding batteries you will do uniformly good work and satisfy all your customers. The essential thing for the success of your battery business is to learn the Standard method and use it. Do not rush a battery through your shop, and leave out some of the steps of the process, even though the owner may be in a hurry. If you have a good stock of rental batteries you can put one on his car and keep it there until you have done as good a job of rebuilding on his battery as you possibly can. Remember that the Standard method which has been described has not simply been figured out as being a good method. This method has been worked out in the actual rebuilding of thousands and thousands of batteries of all makes and in all conditions, and has produced batteries full of life and power, ready to give one to two years more of good, reliable service. Burning on Plates When you put new plates into a battery, or find some of the plates broken from the connecting strap, it will be necessary to burn the plates to the strap. Frequently you will find plates which are otherwise in a good condition broken from the connecting straps. This is most likely to happen when the plates have been cast on to the connecting strap instead of being burned on. These plates must be burned on. New plates are frequently necessary. From pages 339 to 346 you see that new plates are required under the following conditions: (a) Positives. Ruined by freezing; weak and brittle from age, large part of active material shed; badly buckled; rotten and disintegrated by impurities; reversed. Positives in a reasonably good mechanical condition can be restored to a good electrical condition by charging. (b) Negatives. Active material granulated, bulged and disintegrated; charged while dry; positives disintegrated by impurities; ruined by overcharging; badly sulphated because allowed to stand idle, or used while discharged; much active material lost, and that which is left soft and mushy; negatives reversed by charging battery backwards. When making plate renewals, never install plates of different design in the same group. Always use plates of the type intended for the battery. The battery should first be fully charged, as already explained. If all the plates in a group are to be discarded, clamp the post in a vise, being careful not to crack the hard rubber shell if one is on it, or to damage the threads on Posts such as the Exide or to draw up the vise so tightly as to crush the post. Then saw off all the old plates with a new coarse toothed hacksaw, a sharp key hole saw, or any good saw which has a wide set, close to the post. This separates the entire group of plates from the post in one short operation. This method is much better than the one of sawing the plates off below the connecting strap, and sawing or punching the old plate ends out of the strap. See page 217 for instructions for welding plates to the straps. Work on the Jars The work on the jars consists of removing any sediment which may have collected, washing out all dirt, and replacing leaky jars. The removal of sediment and washing should be done after the preliminary charge has been given and the old electrolyte poured out unless the preliminary charge was given with distilled water in the jars. The old electrolyte need not be poured down the sewer, but may be kept in stone or earthenware jars and used later in making electrical tests to locate leaky jars. Testing Jars Remove all sealing compound from the jar by means of a hot putty knife, finishing by wiping with a gasoline soaked rag. Inspect each jar carefully under a strong light for cracks and leaks. If you know which jar is leaky by having filled each cell with water up to the correct level, when you made the first examination of the battery, and then having it allowed to stand over night to see if the electrolyte in any cell has dropped below the tops of the plates, no tests are necessary, but if you are in doubt as to which jar, if any, is leaky, you must make tests to determine which jar is leaky. If you know that there is no leaky jar, because of the bottom of the case not being acid eaten and rotted, it is, of course, not necessary to test the jars. One test consists in filling the jar within about an inch of the top with old or weak electrolyte, partly immersing the jar in a tank which also contains electrolyte, and applying a voltage of 110 or 220 between the electrolyte in the jar and the electrolyte in the tank in which the jar is partly immersed. If current Vows, this indicates that the jar is leaky. [Fig. 220 Testing jar for leaks, using a 15-watt lamp in series with test circuit] Fig. 220 shows the principle of the test. A suitable box,--an old battery case will do--is lined with sheet lead, and the lead lining is connected to either side of the 110 or 220 volt line. The box is then partly filled with weak electrolyte. The jar to be tested is filled to within about one inch of the top with weak electrolyte. The jar is immersed to within about an inch of its top in the box. The top part of the jar must be perfectly dry when the test is made, or else the current will go through any electrolyte which may be wetting the walls of the jar. A lead strip or rod, which is connected to the other side of the 110 or 220 volt line, through a lamp as shown, is inserted in the jar. If there is, a leak in the jar, the lamp will burn, and the jar must be discarded. If the lamp does not light, the jar does not leak. Instead of using a lead lined box, a stone or earthenware jar may be used. A sheet of lead should be placed in this jar, being bent into a circular shape to fit the inside of the jar, and connected to one side of the line. The lead rod or sheet which is inserted in the jar may be mounted on a handle for convenience in making the test. The details of the testing outfit may, of course, be varied according to what material is available for use. The lamps should be suitably mounted on the wall above the tester. [Fig. 221 Testing jar for leaks, using a voltmeter in series with test circuit] This test may be made by using a voltmeter instead of lamps, as shown in Fig. 221. If a voltmeter is used, be especially careful to have the part projecting above the liquid perfectly dry. A leaky cell will be indicated by a reading on the meter equal to the line voltage. [Fig. 222 Testing jar for leaks, using secondary of Ford ignition coil, or any other vibrator ignition coil] A third method uses a Ford ignition coil, as shown in Fig. 222. A leak will be indicated by a spark, or by the vibrator making more noise than it ordinarily does. Instead of using the Ford coil, as shown in Fig. 222, the test may be made as shown in Fig. 223. Fill the jar to within an inch of the top with electrolyte and immerse one of the high tension wires in the electrolyte. Attach the other high tension wire to a wire brush, comb, or rod having a wooden handle and rub it over the outside of the jar. A leak is shown by a spark jumping to the jar. [Fig. 223 Testing jar for leaks, using secondary of Ford ignition coil, or any other vibrator ignition coil] The test may also be made without removing the jar. If the lead lined box be made two feet long, the entire battery may be set in the box so that the electrolyte in the box comes within an inch of the top of the battery case. Fill each jar with weak electrolyte and make the test as before. If this is done, however, remove the battery immediately after making the test and wipe the case dry with a cloth. To make the test in this way, the case must be considerably acid eaten in order to have a circuit through it to the jar. Removing Defective Jars The method of removing the jars from the case depends on the battery. In some batteries the jars are set in sealing compound. To remove a jar from such a battery, put the steam hose from your steamer outfit into the jar, cover up the top of the jar with rags, and steam the jar for about five minutes. Another way is to fill the jar with boiling hot water and let it stand for fully five minutes. Either of these methods will soften the sealing compound around the jar so that the jar may be pulled out. To remove the jar, grasp two sides of the jar with two pairs of long, flat nosed pliers and pull straight up with an even, steady pull. Have the new jar at hand and push it into the place of the old one as soon as the latter is removed. The new jar should first be steamed to soften it somewhat. Press down steadily on the new jar until its top is flush with the tops of the other jars. Some batteries do not use sealing compound around the jars, but simply use thin wooden wedges to hold the jars in place, or have bolts running through opposite faces of the case by means of which the sides are pressed against the jars to hold them in place. The jars of such batteries may be removed without heating, by removing the wedges or loosening the bolts, as the case may be, and lifting out the jars with pliers, as before. New jars should be steamed for several minutes before being put in the case. When you put jars into such batteries, do not apply too much pressure to them, as they may be cracked by the pressure, or the jar may be squeezed out of shape, and the assembling process made difficult. [Fig. 224 Washing sediment from Jars. Water supply controlled by foot valve] Repairing the Case The case may be repaired with all the jars in place, or it may be necessary to remove the jars. If the case is to be junked and the jars used again, the case may simply be broken off, especially if there is much sealing compound around the jars. Empty the old acid from the jars, take the case to the sink and wash out all the sediment, Fig. 224. With the pipe shown in Fig. '14, you have both hands free to hold the case, as the water is controlled by' a foot operated spring cock. If the case is rotten at top, patch it with good wood. If the top and bottom are so rotten that considerable time will be required to repair it, advise the owner to buy a new case. Sometimes the top of the case can be greatly improved by straightening the side edges with a small smoothing plane, and sometimes a 1/2 inch strip or more fitted all along the edge is necessary for a good job. Handles that have been pulled, rotted, or corroded off make disagreeable repair jobs, but a satisfactory job can be done unless the end of the case has been pulled off or rotted. Sometimes the handle will hold in place until the battery is worn out by old age if three or four extra holes are bored and countersunk in the handle where the wood is solid, and common wood screws, size 12, 1/2 or 5/8 inch long used to fasten the handle in place. Sometimes it will be necessary to put in one half of a new end, the handle being fastened to the new piece with brass bolts and nuts before it is put into place. Sometimes you can do a good job by using a plate of sheet iron 1-16 inch thick, and 4 inches wide, and as long as the end of the case is wide. Rivet the handle to this plate with stovepipe, or copper rivets, and then fasten the plate to the case with No. 12 wood screws, 1/2 inch long. If the old case is good enough to use again, soak it for several hours in a solution of baking soda in water to neutralize any acid which may have been spilled on it, or which may be spilled on it later. After soaking the case, rinse it in water, and allow it to dry thoroughly. Then paint the case carefully with asphaltum paint. REASSEMBLING THE BATTERY Reassembling the Elements Take a negative group and put it on edge on a board, with post away from you, and lower edge toward you. Mesh a positive in the negative group. The groups are now ready for the separators. Take six moist separators from your stock. Slip one into position from the bottom in the middle of the group, with the grooved side toward the positive plate, spreading the plates slightly if necessary. Take another separator, slip it into position on the opposite side of the positive against which your first separator was placed. In this way, put in the six separators, with the grooved side toward the positives, working outward in both directions from the center, Fig. 225. The grooves must, of course, extend from the top to the bottom of the plate. Now grasp the element in both hands, and set it right side up on the block, giving it a slight jar to bring the bottoms of the plates and separators on a level. [Fig. 225 Inserting separators] Now grasp the element in both hands, and set it right side up on the block, giving it a slight jar to bring the bottoms of the plates and separators on a level. Next take a cover, and try it on the posts, Fig. 226. Pull the groups apart slightly, if necessary, before inserting any more separators, so that the cover fits exactly over the posts, Fig. 227. See that the separators extend the same distance beyond each side of the plates. You may take a stick, about 10 inches long, 1 1/2 inches wide, and 7/8 inch thick, and tap the separators gently to even them up. A small wood plane may be used to even up the side edges of wood separators. If you put in too many separators before trying on the cover, the plates may become so tight that you may not be able to shift them to make the cover fit the posts or you may not be able to shift the separators to their proper positions. It is therefore best to Put in only enough separators to hold the groups together and so they can be handled and yet remain in their proper position when set up on the block. Without separators, the posts will not remain in position. [Fig. 226 Trying on a cover] [Fig. 227 Shifting groups to make cover fit] With the element reassembled, and the remaining separators in their proper positions, see that all the plates are level on bottom, and no foreign matter sticking to them. Place the element in box shown in Fig. 219 to keep clean. Reassemble the other elements in exactly the same way, and put them in the box. The elements are now ready to be put in the jars. Putting Elements in Jars Steam the jars in the steamer for about five minutes to soften them somewhat, so that there will be no danger of breaking a jar when you put in the elements. With the case ready, look for the "+", "P" or "POS" mark on it. (Cases which are not marked in this way at the factory should be marked by the repairman before the battery is opened.) Place the case so that this mark is toward you. Grip an element near the bottom in order to prevent the plates from spreading, and put it in the jar nearest the mark, with the positive post toward you, next to the mark. Put an element in the next jar so that the negative post is toward you. Put an element in the third jar so that the positive post is toward you, and so on. The elements are correctly placed when each connecting strap connects a positive to a negative post. If the case has no mark on it, reassemble exactly according to the diagram you made on the tag before you opened the battery. Set the jars so that the posts are exactly in line so that the cell connectors will fit. [Fig. 228 Tightening a loose element by placing a separator against outside negative] If an element fits loosely in the jar, it must be tightened. The best way to do this is to put one or more separators on one or both sides of the elements before putting it in the jar, Fig. 228. If you leave the elements loose in the jars, the jolting of the car will soon crack the sealing compound, and you will have a "slopper" on your hands. If element fits very tight, be sure that the corners of the plate straps have been rounded off and trimmed flush with outside negatives. Be sure also that there is no compound sticking to the inside of jars. Take care not to break the jar by forcing in a tight fitting element when the jar is cold and stiff. Filling Jars with Electrolyte or Putting on the Covers With all the elements in place in the jars, one of two things may be. done. First, the jars may be filled with electrolyte and the covers then sealed on, or the covers may first be sealed on and the jars then filled with electrolyte. Each method has its advantages and disadvantages. If the jars are first filled with electrolyte, acid may be splashed on the tipper parts of the jars and sealing made very difficult. On the other hand, if the electrolyte is first poured in, the charged negatives will not become hot, and sealing compound which runs into the jar will be chilled as soon as it strikes the electrolyte and will float on top and do no harm. If the covers are sealed before any electrolyte is added, it will be easier to do a good sealing job, but the negatives will heat up. Furthermore, any sealing compound which runs into the jar will run down between the plates and reduce the plate area. If care is taken to thoroughly dry the upper parts of the jars, add the electrolyte before sealing on the covers. Use 1.400 Acid If you have followed the directions carefully, and have therefore freed all the shorts, have thoroughly charged the plates, have washed and pressed the negative groups, have washed the positives, have then added any new plates which were needed, and have put in new separators, use 1.400 specific gravity electrolyte. This is necessary because washing the plates removed some of the acid, and the new separators will absorb enough acid so that the specific gravity after charging will be about 1.280. The final specific gravity must be between 1.280 and 1.300. In measuring the specific gravity the temperature must be about 70°F., or else corrections must be made. For every three degrees above 70°, add one point (.001) to the reading you obtain on the hydrometer. For every three degrees under 70°, subtract one point (.001) from the reading you obtain on the hydrometer. For instance, if you read a specific gravity of 1.275 and find that the temperature of the electrolyte is 82°F., add ((82-70)/3 = 4)four points (1.275 + .004), which gives 1.279, which is what the specific gravity of the electrolyte would be if its temperature were lowered to 70°. The reason this is done is that when Ave speak of an electrolyte of a certain specific gravity, say 1.280, we mean that this is its specific gravity when its temperature is 70°F. We must therefore make the temperature correction if the temperature of the electrolyte is much higher or lower than 70°F. Putting on The Covers This operation is a particular one, and must be done properly, or you will come to grief. Get the box containing the covers and connectors for the battery you are working on; take the covers, and clean them thoroughly. There are several ways to clean them. If you have gasoline at hand, dip a brush in it and scrub off the compound. The covers may also be cleaned off with boiling water, but even after you have used the hot water, it will be necessary to wipe off the covers with gasoline. Another way to soften any compound which may be sticking to them, is to put the covers in the Battery Steamer and steam them for about ten minutes. This will also heat the covers and make them limp so that they may be handled without breaking. If the covers fit snugly all around the inside of the jars so that there is no crack which will allow the compound to run down on the elements, all is well and good. If, however, there are cracks large enough to put a small, thin putty knife in, you must close them. If the cracks are due to the tops of the jars being bent out of shape, heat the tops with a soft flame until they are limp, (be careful not to burn them). Now, with short, thin wedges of wood, (new dry separators generally answer the purpose), crowd down on the outside edges of the jar, until you have the upper edge of jars straight and even all around. If the jars are set in compound, take a hot screwdriver and remove the compound from between the jar and case near the top. If the cracks between cover and jar still remain, calk them with asbestos packing, tow, or ordinary wrapping string. Do not use too much packing;--just enough to close the cracks is sufficient. When this is done, see that the top of the case is perfectly level, so that when the compound is poured in, it will settle level all around the upper edge of the case. Sealing Compounds There are many grades of compounds (see page 149), and the kind to use must be determined by the type of battery to be sealed. There is no question but that a poor grade used as carefully as possible will soon crack and produce a slopper. A battery carelessly sealed with the best compound is no better. The three imperative conditions for a permanent lasting job are: 1. Use the best quality of the proper kind of compound for sealing the battery on hand. 2. All surfaces that the compound comes in contact with must be free from acid and absolutely clean and dry. 3. The sealing must be done conscientiously and all details properly attended to step by step, and all work done in a workmanlike manner. With respect to sealing, batteries may be divided into two general classes. First, the old type battery with a considerable amount of sealing compound. This type of battery generally has a lower and an upper cover, the vent tube being attached or removable, depending on the design. The compound is poured on top of the lower cover and around the vent tube, and the top covers are then put on. Most of the batteries of this type have a thin hard rubber sleeve shrunk on the post where the compound comes in contact with it; this hard rubber sleeve usually has several shallow grooves around it which increase its holding power. This is good construction, provided everything else is normal and the work properly done with a good stick-, compound. There are a few single cover batteries with connecting straps close to top of covers, and the compound is poured over the top of the straps. See Fig. 262. The second general type consists of single one-piece cover batteries that have small channels or spaces around the covers next to the jars into which the sealing compound is poured. This type of battery is the most common type. [Fig. 229 Pouring compound on lower covers] Compound in bulk or in thin iron barrels can be cut into small pieces with a hatchet or hand ax. To cut off a piece in hot weather, strike it a quick hard blow in the same place once or twice, and a piece will crack off. Directions for properly beating sealing compound will be found on page 150. Sealing Double Cover Batteries The following instructions apply to batteries having double covers. These are more difficult to seal than the single cover batteries. If you can seal the double cover batteries well, the single cover batteries will give you no trouble. Always start the fire under the compound before you are ready to use it, and turn the fire lower after it has melted, so as not to have it too hot at the time of pouring. If you have a special long nosed pouring ladle, fill it with compound by dipping in the pot, or by pouring compound from a closed vessel. If you heat the compound in an iron kettle, pour it directly into pouring ladle, using just about enough for the first pouring. The compound should not be too hot, as a poor sealing job battery will result from its use. See page 150. Before sealing, always wipe the surfaces to be sealed with a rag wet with ammonia or soda solution, rinsed with water, and wiped dry with a rag or waste. If you fail to do this the compound will not stick well, and a top leak may develop. Then run a soft lead burning flame over the surfaces to be sealed, in order to have perfectly dry surfaces. Remember that sealing compound will not stick to a wet surface. [Fig. 230 First pouring of sealing compound] [Fig. 231 Cooling compound with electric fan] Pour compound on the lower covers, as in Fig. 229. Use enough to fill the case just over the tops of the jars, Fig. 230. Then pour the rest of the compound back in compound vessel or kettle. To complete the job, and make as good a job as possible, take a small hot lead burning flame and run it around the edges of case, tops of jars, and around the posts until the compound runs and makes a good contact all around. If you have an electric fan, let it blow on the compound a few minutes to cool it, as in Fig. 231. Then the compound used for the second pouring may be hotter and thinner than the first. Fill the pouring ladle with compound, which is thinner than that used in the first pouring, and pour within 1/16 inch of the top of the case, being careful to get in just enough, so that-after it has cooled, the covers will press down exactly even with the top of the case, Fig. 232. It will require some experience to do this, but you will soon learn just how much to use. As soon as you have finished pouring, run the flame all around the edges of the case and around the post, being very careful not to injure any of the vent tubes. A small, hot-pointed flame should be used. Now turn on the fan again to cool the compound. [Fig. 232 Second pouring of sealing compound] While the compound is cooling, get the cell connectors and terminal connectors, put them in a two-quart granite stew pan, just barely cover with water, and sprinkle a tablespoon of baking soda over them. Set the stew pan over the fire and bring water to boiling point. Then pour the water on some spot on a bench or floor where the acid has been spilled. This helps to neutralize the acid and keep it from injuring the wood or cement. Rinse off the connectors and wipe them dry with a cloth, or heat them to dry them. [Fig. 233 Pressing covers down to make them level with top of case] Now take the top covers, which must be absolutely clean and dry, and spread a thin coat of vaseline over the top only, wiping off any vaseline from the beveled edges. Place these covers right side up on a clean board and heat perfectly limp with a large, spreading blow torch flame. Never apply this flame to the under side of the top covers. The purpose is to get the covers on top of the battery absolutely level, and exactly even with the top of the case all around it, and to have them sticking firmly to the compound. There is not an operation in repairing and rebuilding batteries that requires greater care than this one, that will show as clearly just what kind of a workman you are, or will count as much in appearance for a finished job. If you are careless with any of the detail, if just one bump appears on top, if one top is warped, if one cover sticks above top of case, try as you may, you never can cover it up, and show you are a first-class workman. See that you have these four conditions, and you should not have any difficulty after a little experience: [Fig. 234 Pressing covers down around posts to make them flush with top of case] 1. You must have just enough compound on top to allow the top covers to be pressed down exactly even with upper edge of case. 2. The top covers must be absolutely clean and have a thin coat of vaseline over their top, but none on the bevel edge. 3. A good sized spreading flame to heat quickly and evenly the tops to a perfectly limp condition without burning or scorching them. 4. Procure a piece of 7/8-inch board 1-1/2 inches wide and just long enough to go between handles of battery you are working on. Spread a thin film of oil or vaseline all over it. Having heated the covers and also the top surface of the compound until it is sticky so that the covers may be put down far enough and adhere firmly to it, place the covers in position. Then press the covers down firmly with a piece of oiled wood, as in Fig. 233, applying the wood sidewise and lengthwise of case until the top of cover is exactly even with the top of the case. It may be necessary to use the wood on end around the vent tubes and posts as in Fig. 234, to get that part of the cover level. If the compound comes up between covers and around the edges of the case, and interferes with the use of the wood, clean it out with a screwdriver. You can then finish without smearing any compound on the covers. [Fig. 235 Wiping bottom of spoon filled with sealing compound] [Fig. 236 Filling cracks around covers with sealing compound] When you have removed the excess compound from the cracks around the edges of the covers with the screwdriver, take a large iron spoon which has the end bent into a pouring lip, and dip up from 1/2 to 2/3 of a spoonful of melted compound (not too hot). Wipe off the bottom of the spoon, Fig. 235, and pour a small stream of compound evenly in all the cracks around the edges of the covers until they are full, as in Fig. 236. Do not hold the spoon too high, and do not smear or drop any compound on top of battery or on the posts. No harm is done if a little runs over the outside of the case, except that it requires a little time to clean it off. A small teapot may be used instead of the spoon. If you have the compound at the right temperature, and do not put in too much at a time, you will obtain good results, but you should take care not to spill the compound over covers or case. [Fig. 237 Final operation of cleaning off excess compound] After the last compound has cooled,--this requires only a few minutes,--take a putty knife, and scrape off all the surplus compound, making it even with the top of the covers and case, Fig. .237. Be careful not to dig into a soft place in the compound with the putty knife. If you have done your work right, and have followed directions explicitly, you have scraped off the compound with one sweep of the putty knife over each crack, leaving the compound smooth and level. You will be surprised to see how finished the battery looks. Some workmen pour hot compound clear to the top of the case and then hurry to put on a cold, dirty top. What happens? The underside of the cover, coming in contact with the hot compound, expands and lengthens out, curling the top surface beyond redemption. As you push down one corner, another goes up, and it is impossible to make the covers level. Sealing Single Cover Batteries Single cover batteries are scaled in a similar manner. The covers are put in place before any compound is poured in. Covers should first be steamed to make them soft and pliable. The surfaces which come in contact with the sealing compound must be perfectly dry and free from acid. Before pouring in any compound, run a soft flame over the surfaces which are to be sealed, so as to dry them and warm them. Close up all cracks between Jars and covers as already directed. Then pour the cover channels half full of sealing compound, which must not be too thin. Now run a soft flame over the compound until it flows freely and unites with the covers and jars. Allow the compound to cool. For the second pouring, somewhat hotter compound may be used. Fill the cover channels flush with the top of the case, and again run a soft flame over the compound to make it flow freely and unite with the covers, and to give it a glossy finish. If any compound has run over on the covers or case, remove it with a hot putty knife. Burning-on the Cell Connectors With the covers in place, the next operation is to burn in the cell connectors. Directions for doing this are given on page 213. If you did not fill the jars with electrolyte before sealing the covers, do so now. See page 364. Marking the Battery You should have a set of stencil letters and mark every battery you rebuild or repair. Stamp "POS," "P," or "+" on positive terminal and "NEG," "N," or on negative terminal. Then stamp your initials, the date that you finished rebuilding the battery, and the date that battery left the factory, on the top of the connectors. Record the factory date, and type of battery in a book, also your date mark and what was done to the battery. By doing this, you will always be able to settle disputes that may arise, as you will know when you repaired the battery, and what was done. To go one step farther, keep a record of condition of plates, and number of new plates, if you have used any. Grade the plates in three divisions, good, medium and doubtful. The "doubtful" division will grow smaller as you become experienced and learn by their appearance the ones to be discarded and not used in a rebuilt battery. There is no question that even the most experienced man will occasionally make a mistake in judgment, as there is no way of knowing what a battery has been subjected to during its life before it is brought to you. Cleaning and Painting the Case The next operation is to thoroughly clean the case; scrape off all compound that has been spilled on it, and also any grease or dirt. If any grease is on the case, wipe off with rag soaked in gasoline. Unless the case is clean, the paint will not dry. Brush the sides and end with a wire brush; also brighten the name plate. Then coat the case with good asphaltum paint. Any good turpentine asphaltum is excellent for this purpose. If it is too thick, thin it with turpentine, but be sure to mix well before using, as it does not mix readily. Use a rather narrow brush, but of good quality. Paint all around the upper edge, first drawing the brush straight along the edges, just to the outer edges of rubber tops. Now paint the sides, ends and handles, but be careful not to cover the nameplate. To finish, put a second, and thick coat all around top edge to protect edge of case. Paint will soak in around the edge on top of an old case more easily than on the body of the case as it is more porous. Charging the Rebuilt Battery With the battery completely assembled, the next step is to charge it at about one-third of the starting or normal charge rate. For batteries having a capacity of 80 ampere hours or more, use a current of 5 amperes. Do not start the charge until at least 12 hours after filling with electrolyte. This allows the electrolyte to cool. Then add water to bring electrolyte up to correct level if necessary. The specific gravity will probably at first drop to 1.220-1.240, and will then begin to rise. Continue the charge until the specific gravity and voltage do not rise during the last 5 hours of the charge. The cell voltage at the end of the charge should be 2.5 to 2.7, measured while the battery is still on charge. Make Cadmium tests on both positive and negatives. The positives should give a Cadmium reading of 2.4 or more. The negatives should give a reversed reading of 0.175. The tests should be made near the end of the charge, with the cell voltages at about 2.7. The Cadmium readings will tell the condition of the plates better than specific gravity readings. The Cadmium readings are especially valuable when new plates have been installed, to determine whether the new plates are, fully charged. When Cadmium readings indicate that the plates are fully charged, and specific gravity readings have not changed for five hours, the battery is fully charged. If you have put in new plates, charge for at least 96 hours. Measure the temperature of the electrolyte occasionally, and if it should go above 110°F., either cut down the charging current, or take the battery off charge long enough to allow the electrolyte to cool below 90°F. Adjusting the Electrolyte If the specific gravity of the electrolyte is 1.280 to 1.300 at the end of the charge, the battery is ready for testing. If the specific gravity is below or above these figures, draw off as much electrolyte as you can with the hydrometer. If the specific gravity is below 1.280, add enough 1.400 specific gravity electrolyte with the hydrometer to bring the level up to the correct height (about 1/2 inch above tops of plates). If the specific gravity is above 1.300, add a-similar amount of distilled water instead of electrolyte. If the specific gravity is not more than 15 points (.015) too low or too high, adjust as directed above. If the variation is greater than this, pour out all the electrolyte and add fresh 1.280 specific gravity electrolyte. After adjusting the electrolyte, continue the charge until the gravity of all cells is 1.280-1.300, and there is no further change in gravity for at least two hours. Then take the battery off charge and make a final measurement of the specific gravity. Measure the temperature at the same time, and if it varies more than 10° above or below 70°, correct the hydrometer readings by adding one point (.001 sp. gr.) for each 3 degrees above 70°, and subtracting one point (.001 sp. gr.) for each 3 degrees below 70°. Be sure to wipe off any electrolyte which you spilled on the battery in adjusting the electrolyte or measuring the specific gravity. Use a rag dipped in ammonia, or baking soda solution. High Rate Discharge Whenever you have time to do so, make a 20-minute high rate discharge test on the rebuilt battery, as described on page 266. This test will show up any defect in the battery, such as a poorly burned joint, or a missing separator, and will show if battery is low in capacity. If the test gives satisfactory results, the battery is in good condition, and ready to be put into service, after being charged again to replace the energy used by the test. ================================================================ CHAPTER 16. SPECIAL INSTRUCTIONS. --------------------- EXIDE BATTERIES Exide batteries may be classified according to their cover constructions as follows: 1. Batteries with single flange covers, as shown in Figs. 15 and 238. This class includes types DX, LX, LXR, LXRV, PHC, XC, XX, and XXV. [Fig. 238 Exide Battery, partly disassembled] 2. Batteries with double flange covers, as shown in Fig. 242. This class includes types MHA, KZ, KXD, LXRE, and XE. The cover constructions are-described in Chapter 3. All Exide batteries, except types KXD, LXRE, and XE, have burned-in lead top connectors. All types have a removable sealing nut around each post to make a tight joint between the post and cell cover, as described on page 19. Formerly some Exide batteries had cell connectors which were bolted to the cell posts, but this construction is now obsolete. Types KXD, LXRE, and XE have cell connectors made of flexible, lead coated copper strips. Types DX, LX, LXR, LXRV, MHA, PHC, XC, XX, and XXV have been designed and built to meet the requirements of starting, lighting and ignition service for passenger automobiles and power boats. Types KXD, LXRE, and XE have been especially developed to meet the requirements of the starting, lighting and ignition service on motor trucks and tractors. Type KZ has been produced particularly for motorcycle lighting and ignition service. [Fig. 239 Exide Battery with Single Flange Cover] Type Numbers The type of an Exide battery is stamped on the battery name plate. Thus, on one of the most popular Exide batteries is marked Type 3-XC-13-1. Other Exide batteries have different numerals and letters in their type numbers, but the numerals., and letters are always arranged in the same order as given above. The first numeral gives the number of cells. The letters give the type of cell. The numerals following the letters give the number of plates per cell. The last numeral indicates the manner of arranging the cells in the battery case. Thus, in the example given above, 3-XC-13-1 indicates that there are three cells in the battery, that the type of cell is XC, that each cell has 13 plates, and that the cells are arranged according to method No. 1, this being a side to side assembly. Methods of Holding Jars in Case Two methods of holding Exide jars in the battery case are used: 1. Types MHA, KXD, LXRE, and XE have the jars separated by horizontal wooden spacers, there being two spacers between adjoining jars. Running horizontally between these two spacers are tie bolts which pass through the case. These bolts are tightened after the jars are placed in the case, thus pressing the sides of the case against the jars and holding them in, place. Types KXD, LXRE, and XE, in addition to the tie bolts, are secured in the case by sealing compound beneath and around the jars. Each cell is provided with two soft rubber buffers which are V shaped, and are placed over the ridges in the bottom of the jars, thereby minimizing the effect of shocks on the plates and separators which rest on the buffers. 2. In types DX, LX, LXR, LXRV, PHC, XC, XX, and XXV, there are no spacers between adjoining jars, and the jars simply fit tight in the case. Should they not fit tight enough to hold them in place securely, thin boards are inserted between the jars and the case to pack them in. Type KZ has the three sets of plates in one jar, having three compartments, with a three compartment cover. Opening Exide Batteries 1. Drilling Off the Top Connectors. Do this as described on page 329. For type KZ batteries use a 3/8 inch drill. For all other types use a 5/8 inch drill. 2. Removing Plates from Jars. Follow the general instructions on page 333. Types DX, LX, LXR, LXRV, PHC, XC, XX, and XXV. In opening these batteries, all of which have the single flange cover, you may remove each cell complete from the case, and then draw out the plates; or you may draw out the plates without taking out the jars. To remove the complete cell, heat a thin bladed putty knife and work it down all around the outside of the jar. Then lift out the complete cell by pulling steadily on the cell posts with two pairs of gas pliers. The battery should be placed on the floor when you do this, and you should stand with one foot pressed against the side of the case. If you do not wish to remove the complete cells, or should the jars fit too tight in the case, unseal the covers and remove the plates according to the instructions given on page 333. Types KZ and MHA. These batteries have the double flanged cover. Several methods may be used in removing the plates from the jars. In each case, the top of the cell is cleaned, gas blown out of the vent holes, and the sealing nuts removed before opening the cells. [Fig. 240 Removing double flange exide cover] First, a flame may be used to soften the sealing compound which is placed in the slot formed by the two flanges of the cover. If you wish to use a flame, first remove each complete cell from the case, loosening the tie bolts that pass through the case to release the jars. Then hit out each complete cell. Now get two strong boards which are about one fourth inch longer than the height of the jar. See Fig. 240. Support the jar on these boards by resting the lower edge of the sides of the cover on the top edge of the boards. Then run a moderate flame around the outside of the flange until the cover is soft, and the compound melting. Then press down on the cell posts with your thumbs, and the jar and plates will drop free of the cover. The plates are then drawn out and rested on the top of the jars to drain, as usual. Another method is to remove the cells from the case and put them in the battery steamer for ten minutes as described on page 332. Instead of first taking the complete cells out of the case and then steaming them separately, you may steam the entire battery for about ten minutes, and then draw out the plates and cover of each cell with gas pliers without removing the jars. This method must be used in opening types KXD, LXRE, and XE, which have sealing compound under the jars. Work on Plates, Separators, Jars, and Case Having opened the battery, follow the instructions given on pages 335 to 361 for examination of plates and separators, and all work on plates, jars, separators, and case. Reassembling Plates [Fig. 241 Upsetting threads to prevent nut from turning] First slip the positive and negative groups together without separators. Then wipe the posts with a rag moistened with ammonia, rinse them with water, and dry thoroughly with a clean rag. Next slip the soft rubber washers over the posts and place the cover in position. Lubricate the lead sealing nuts with graphite that has been mixed to a paste with water. Do not use grease or vaseline to lubricate these nuts. Then put on the sealing nuts and tighten them partly with your fingers. You are now ready to insert the separators as directed on page 361. Types MHA, PHC, KXD, KZ, LXR, LXRE, LXRV, XX, and XXV have, in addition to the usual wooden separators, perforated rubber sheets, which should be placed against the grooved side of each wooden separator before inserting, and insert with rubber sheet against the positives. Make a careful examination to see that you have not left out any separators. When the separators are all in place, even them up on each side. Then tighten the sealing nuts with the special Exide wrench. When you have turned the nuts down tight, lock them in place by driving a center punch on the threads on the post just above the nut, Fig. 241. This will damage the thread and prevent the nut from turning loose. Putting Plates In Jars The next step is to lower the plates into the jars, as described on page 362. In types KXD, LXRE, and XE be sure to first replace the two soft rubber buffers in the bottom of the jar, one over each ridge. Filling Jars With Electrolyte As soon as you have an element in place in the jar, fill the jar with electrolyte of the proper strength, as described on page 364, to prevent the separators and plates from drying. The negatives, especially, must be covered with electrolyte to prevent them from heating and drying. Sealing Exide Battery Covers [Fig. 242 Laying "worm" of sealing compound] [Image: Chart showing capacity of Exide batteries] For Types DX, LX, LXR, LXRV, PHC, XC, XX, and XXV, which have the single flange type of cover, slowly heat the sealing compound until it runs, but do not get it so thin that it will run down into the cell between the cover and jar. Then pour it into the channel between cover and jar walls. Allow it to cool and finish it off flush with a hot knife. When pouring, be sure the compound is liquid and not lumpy, as in such a case a poor seal will result. A glossy, finished appearance may be given to the compound by passing a flame over it after the job is finished. For Types KXD, KZ, LXRE, MHA, and XE, which have the double flange type of cover, have ready a string or worm of sealing compound about 3-16 inch in diameter, made by rolling between boards some of the special compound furnished for the purpose. The cover may or may not have been attached to the element, depending on how repairs have been made. In either case the procedure is the same as far as sealing is concerned. Assuming the element is attached, stand it upside down, with the cover resting upon two strips, Fig. 242. Lay the string of compound all around the cover channel. Now turn right side up and insert in the jar, taking care that the jar walls enter the cover channels at all points. Apply heat carefully to the edges of the cover and gently force cover clown. If too much compound has been used, so that it squeezes out around the cover, scrape off the excess with a hot knife while forcing cover down. Putting Cells In Case When the covers have all been sealed, put the cells in the case, taking care to put the negative and positive posts in their proper positions, so that each cell connector will connect a positive to a negative post. In Types MHA, KXD, LXRE, and XE, which have wooden spacers between the cells, take care that the spacers are in position and then, after cells are in place, tighten the tie bolts with a screw driver to clamp the jars. In Types DX, LX, LXR, LXRV, SX, XC, XX, and XXV the cells should fit tight in the case; pack them in with thin boards if necessary. Burning on the Cell Connectors See instructions on pages 213 to 216. Charging After Repairing See also instructions on page 373. Not sooner than ten to fifteen hours after filling battery with electrolyte, add electrolyte to restore level if it has fallen. U. S. L. BATTERIES The instructions for rebuilding batteries which have already been given, pages 328 to 374, apply also to all U. S. L. batteries. In working on the old U. S. L. batteries, illustrated in Fig. 243, draw out the electrolyte down to the tops of the plates so that the electrolyte is below the lower end of the vent tube. Then blow out any gas which may have collected under the cover with compressed air or bellows. Never fail to do this, as there is only a small vent hole in the cover through which the gas can escape, the vent tubes extending down into the electrolyte when the cells are properly filled. [Fig. 243 Cross section of old type USL battery] [Fig. 244 Cross section of new type USL battery] Fig. 244 shows the new U. S. L. cover construction. Note that the special cell filling device is no longer used. U. S. L. batteries have lead bushings moulded into the cover. These bushings fit around the posts, and are burned to the posts and top connectors, Figs. 243 and 244, thus giving leak proof joints between the cover and the posts. In burning on the connectors, melt bottom edge of hole first, then top of post and cover bushing, and melt in your burning lead slowly. [Image: Chart showing capacity of USL batteries, Page 1] [Image: Chart showing capacity of USL batteries, Page 2] PREST-O-LITE BATTERIES [Fig. 245 Old type Prest-O-Lite battery with lead bushings that screw up into cover] Some of the old Prest-O-Lite batteries have a lead bushing around the post, Fig. 245, similar to the U. S. L. batteries. This will make a perfectly tight seal, provided that you screw the bushing up tight. The new types of Prest-O-Lite batteries have a "Peened" post seal, special instructions for which follow. The general instructions for rebuilding batteries given on pages 328 to 374 apply to Prest-O-Lite batteries in every respect. The "Peened" post seal is, however, a special construction, and directions for working on this seal are as follows: [Fig. 246 Prest-O-Lite Element Locked] All Prest-O-Lite batteries designated as Types WHN, RIJN, BHN, JFN, KPN, and SHC, have a single moulded cover which is locked directly on to the posts of the element. This feature is the result of forcing a solid ring of lead from a portion of the post, projecting above the cover, down into a deep chamfer in the top of the cover. Figs. 246 and 247 show this construction. This construction makes a solid unit of the cover and element, which does away with the sealing compound, washers, nuts, etc., for making the acid tight seal around the posts. The locking operation requires some special instructions and shop equipment for assembly and all repairs which involve removal from and replacement of the cover on the element. The majority of battery repairs such as renewal of jars, separators, straightening of plates, and removal of sediment, can be made without separating the cover and element. In such cases the connectors are drilled off, compound is softened and removed from around the covers and the complete unit is removed from the cell. It may be handled throughout the repair as a unit, and the cover serves as a bridge to hold the plates of both groups in line just as they remain in the jar. [Fig. 247 Sectional view of Prest-O-Lite battery with peened post seal] However, where the cover is broken or must be replaced for other reasons, when plates have to be renewed, or the posts have been broken off below the cover, the element and cover must be separated. All the apparatus and special tools which are used in connection with the locking, as well as the building-up, unlocking (freeing), and rebuilding, of the posts in all Prest-O-Lite battery types are grouped together and collectively termed the type "N" Post Locking Outfit. This outfit, complete, is carried in stock at all Prest-O-Lite warehouses under the part number 27116. Each of the individual parts or tools also has a separate part number and may be bought separately. Prest-O-Lite Type "N" Post Locking Outfit Arbor Press (complete with following 12 parts) 27115 Main Casting 27114 Latch 27107 Bed Plate 27113 Lever 27108 Rack 27211 Washer 27112 Pinion Shaft 27110 Pinion 27109 Latch Pin 27111 *Special CLN & KPN Spacer 27233 *Special CLN & KPN Latch 27232 *Special CLN & KPN Bed Plate 27234 Large Peening Tool (9-21 RHN, WHN, BHN, SHC, KPN, CLN; 11-17 JFN) 27101 Small Peening Tool (7-WHN, RHN, SHC; 9-JFN) 27100 Peening Tool for small terminal posts in which are east threaded brass inserts (Columbia) 27105 Large Post Freeing Tool 27103 Small Post Freeing Tool 27102 No. 8 Post Freeing Tool (13/16" diameter straight post) 27123 [1] Large Post Re-Builder (9-21 RHN, WHN, BHN, SHC, KPN, CLN; 11-17 JFN) 27005 [1] Small Post Re-Builder (7-WHN, RHN, SHC; 9-JFN) 27004 [2] Ford Positive Post Builder 27006 [2] Ford Negative Post Builder 27224 2 No. 8 Post Builder (13/16" diameter straight post) 27225 Style "B" Prest-O-Lite Torch, with six feet of red gum tubing A-3116 Automatic Reducing Valve A-427 COMPLETE TYPE "N" OUTFIT including all parts above 27116 * The CLN and KPN Spacer block, bent Latch and Bed Plate are special parts used only in the Arbor Press when it is especially assembled to lock CLN or KPN posts. [1] The Re-Builder is used to build up posts before attempting to lock on the cover. The replacing of the metal cut away from the original diameter of the post when the jar cover was removed is necessary to the correct operation of the Peening Tool. [2] The Builder is used to build up posts, after they have been locked and shaped by the Peening Tool, to a size large enough to take some special terminal. For example, the Ford Positive Post Builder is used in building up posts, locked by the Large Peening Tool, to the proper size to take the Ford positive terminal. The Automatic Reducing Valve delivers the gas from the P-O-L tank at a uniform pressure of 3 pounds per square inch, whether the tank is full, half empty, or nearly empty, and regardless of the volume of gas used. The volume or flow of gas is regulated by the key. The style "B" torch mixes the pure acetylene from the gas tank with the proper amount of air necessary to an efficient heating flame. The heating flame is conducted or delivered to the Peening Tool by the short length of brass tubing known as the Torch-Holder, over which the "B" Torch is pressed by hand in completing the assembly. [Fig. 248 Special Prest-O-Lite Peening Press] Both the "B" Torch and the Automatic Reducing Valve are absolutely essential to the use of the Prest-O-Lite gas tank for heating the Peening Tool. Prest-O-Lite gas tanks, style A, B, C, or E, may be used in connection with the Automatic Reducing Valve, as shown in Fig. 248. To use a welding size gas tank it is necessary to insert a "W to A" Adapter between the tank and Reducing Valve. This Adapter can be purchased from the Prest-O-Lite Co., Inc. The Arbor Press when received by the Service Station is fully assembled, ready for mounting and operation with all P-O-L locked post types except CLN and KPN. Mount the Press in a vertical position (Fig. 248) in a convenient place and at an accessible height on a wall or post. Holes are provided in the Press for mounting by lag screws or bolts. The position of the Peening Tool should be well below the level of the eyes, to prevent serious injury from a possible spattering of overheated lead. Screw the proper size Peening Tool into the bottom of the Press rack, as shown in Fig. 248. The Torch-Holder must be removed from the Peening Tool to do this; it should be immediately replaced. In using the Press to lock CLN or KPN posts it is necessary to remove the Bed Plate and the Latch, and replace these parts with the Special Bed Plate and Special Latch provided for this purpose, using the spacing block or Spacer (also provided) between the Special Bed Plate and the bottom of the Press. [Fig. 249 Reaming Prest-O-Lite peened post to remove cover] Connect the "B" Torch to the Peening Tool. The Torch is merely pressed by the hand over the Torch-Holder. Connect the Torch with the Automatic Reducing Valve on the gas tank by the rubber tubing, and turn on the gas and light. The flame should be blue and hot. Allow the Peening Tool to become just hot enough to melt the end of a piece of 50-50 solder. Do not allow it to get any hotter than this. The tool is then ready for use. The flame may be left on while the Tool is in use. In case the Tool becomes too hot turn the flame off and allow it to cool to the proper temperature before using. To Remove Cell Covers from Elements Drill off cell connectors and terminals as usual. Insert the proper size Freeing Tool (or reamer), furnished with the outfit, in an ordinary hand-power drill press or bit-and-brace. With this reamer remove the ring of metal or flange on the post, thereby releasing the cell cover. Fig. 249. The Freeing Tool should not be used in a power-driven press, as slow speed is essential to prevent breaking cell covers. To get the best results, center the Freeing Tool over the post, gradually forcing it down, at the same time keep it turning slowly until the ring of metal which locks the post in the cover has been removed. A little machine oil should be put on the metal directly under the tool for this operation. After the metal ring has been removed, the cover can be easily lifted off the posts, Fig. 250. [Fig. 250 Removing Prest-O-Lite cover] [Fig. 251 Building up posts on Prest-O-Lite element] The use of the Freeing Tool in removing the cell cover cuts away a certain amount of metal from the diameter of the posts. Before these posts can be relocked by the Peening Tool in replacing the cell cover they must be built up in size or diameter again so that there will be enough lead to insure a tight joint. To Rebuild Posts Thoroughly clean the post. Place the proper Post Re-Builder so that it rests on the shoulder of the post, and run in enough new lead to fill the Re-Builder. Fig. 251. Be sure and bring the lead surface of the post into fusion before the new lead is run in, to insure a strong post. To build a smooth, solid post, be sure that the post is thoroughly clean; then use a hot flame. To Lock or Peen Posts (1) Assemble positive and negative groups without separators, and paint the posts (just above the shoulder) with hot sealing compound. (2) Prepare the cell covers by immersing them in hot water until they are flexible. (3) Place a warmed cover over the posts of the two assembled groups (the elements). Fig. 252. [Fig. 252 Replacing Prest-O-Lite cover on built-up posts] (4) Slide the element over the Bed Plate directly under Peening Tool, with the bottom of the plate connectors resting on the Bed Plate. (See Fig. 253). (5) Pull down the Latch to hold the Bed Plate in alignment. (6) Center the post with Peening Tool. Then force the Peening Tool down slowly until it has covered about two-thirds of the distance to the cover. Pause in this operation to allow the metal of the post to become heated; then force tool the rest of the distance. Raise the Peening Tool slightly and force down again. (7) Release the Latch, withdraw and reverse the element, and repeat operations 4, 5 and 6 on the other post. (8) The assembled groups are now ready to receive separators. [Fig. 253 Peening Prest-O-Lite post with special peening press] Precautions in Post Locking Operations 1--Be sure all covers are warmed until they are flexible before attempting to assemble. 2--Be sure that the Peening Tool is not too hot. If it is, the post will melt away and be ruined. A very hot tool sometimes causes dangerous spattering of hot lead. 3--Be sure that the post is centered with the Peening Tool before forcing the Tool down on the post. 4--Be sure the cover has been forced down, so that it rests on the shoulder of the post, before releasing. General Instructions In breaking in a new Peening Tool it is advisable to squirt several drops of machine oil inside the Tool, as well as putting some oil on the top of the post, before forcing the hot Tool down over the post. This will prevent the Tool from sticking to the post. If the Peening Tool should stick to the post, force the Tool down again, being certain that the cover is slightly compressed. Sticking of the Peening Tool indicates either that the Tool has not yet been broken in, or that there is not sufficient compression in the cover to free the Tool on releasing the pressure on the lever of the Press. To repair the 13/16" diameter straight terminal post, the Ford positive terminal post, the Ford negative terminal post, it is good practice to remove the cover in the usual manner, then cut the upper portion of the posts off and rebuild them with the large Post Re-Builder. Reassemble the element and cover in the recommended manner and then use the proper Post Builder to burn the post to its original size. Standard Types of Prest-O-Lite Starting, Lighting and Ignition Batteries [Image: Chart for Prest-O-Lite starting batteries, 6-volt] [Image: Chart for Prest-O-Lite starting batteries, 12-volt] [Image: Chart for Prest-O-Lite starting batteries, 16-18-24 and 30-volt] [Image: Chart for Prest-O-Lite special heavy duty truck batteries for starting and light; Chart for 6-volt lighting and ignition types] THE PHILADELPHIA DIAMOND GRID BATTERY Old Type [Fig. 254 Cross section of old type Philadelphia diamond grid battery] Figs. 254 and 255 show the construction of the old type Philadelphia Diamond Grid. Battery. Figs. 254 and 256 show the diamond shaped grid from which the battery derives its name. It is claimed that this construction gives a very strong grid, holding the active materials firmly in place, and giving a large amount of contact surface between the grid and the active material. Figs. 254 and 255 show the old type battery, and give the details of the cover, terminal posts, vent plug, and so on. The post seal is made tight by pouring the compound into the cover well so that it flows in around all of the petticoats on the post. [Fig. 255 Cross section old type Philadelphia Diamond Grid] This construction increases the distance that the acid must travel along the post, in order to cause a leak, about two and one-half times the vertical distance on a smooth post. The hard rubber washer which fits around the post acts as a lock to prevent the post from turning. This applies especially to the two terminal posts to which the cables are attached. The washer is intended to prevent any strain in the cable from turning the post and breaking the seal between the post and the compound. New Development in the Philadelphia Battery [Fig. 256 Cross section new type Philadelphia battery] [Fig. 257 New type Philadelphia Diamond Grid Battery] Rubber Lockt Seal Covers. During the last few years there has been a marked tendency in the battery industry to do away with the use of sealing compound for making a joint between the cell cover and the terminal posts and to substitute a mechanical seal of some kind at this joint. The Philadelphia Storage Battery Co. has developed the "Rubber Lockt". cover seal, the construction of which is shown in detail in Figs. 256 and 257. On the cell posts there is a. flange which supports the cover, and above this there is a recessed portion into which is slipped a soft rubber sleeve or bushing. This portion of the post is made with a ridge extending around the post and with the rubber sleeve forming a high point over which a corresponding locking edge in the terminal hole of the cover is snapped. This construction makes a joint which is flexible and at the same time acid tight. Vibration tends to push the cover down on the supporting flanges, as the post diameter is smaller below the locking edge. The design is simple, both from the assembly and the repair standpoint, as no tools are required for either operation. In the assembly operation the groups are lined up so that the post centers are correct and, after wetting the soft rubber sleeves, the cover is snapped in place with a quick downward push. See Fig. 258. In removing the covers, catch under each end with the fingers and pull upward, at the same time pressing with the thumbs on the top of the posts. See Fig. 259. [Fig. 258 Replacing cover of Philadelphia Diamond Grid Battery] [Fig. 259 Removing cover of Philadelphia Diamond Grid Battery] Rubber Case Batteries. Another development of recent years consists of the replacing of the wood case and rubber jars by a one-piece container of hard rubber with compartments for the elements The Philadelphia Storage Battery Co. has developed the Diamond Rubber case, which combines strength and lightness with an attractive appearance. See Fig. 260. One of the troubles experienced with the earlier designs of the rubber case was the bulging of the end, due to the pull of the battery hold down rod on a small handle attached to the center of the end. In the Philadelphia battery this has been overcome by the use of a wide handle which snaps into openings in the end of the case in such a way that the pull on the handle is transferred to the sides. Another feature of this type handle is that it is a separate piece snapped into the case without the use of any metal insert in the rubber case, and if the handle should break, it can be replaced at small expense without the use of any tools. [Fig. 260 Philadelphia Diamond Grid Battery with rubber case] The Philadelphia vent plug is of the bayonet type, and is tightened by a quarter turn. The plug simply has a small vent hole in the top, and may either be taken out or left on while battery is charging. The Philadelphia Separator The Philadelphia separator is made of quarter sawed hardwood. It has a hard resinous wood in which the hard and soft portions occur in regular alternating vertical layers. The soft layers are porous, and permit the diffusion of the acid from plate to plate. The hard layers give the separator stiffness and long life. The alternating hard and soft layers are at right angles to the surface of the separator, so that the electrolyte has a direct path between plates. The methods of repairing Philadelphia Diamond Grid batteries are no different from those already given, on pages 328 to 374. When the elements of the old type batteries have been assembled and returned to the jars, put the covers in place, and pour the compound around the edges of the cover, and in the post wells. The old compound must be removed from the petticoats on the posts before new compound is poured in. The compound must be warm and thin enough to flow around and fill up the petticoat spaces on the posts in order to get a good seal. When the post wells are full of compound, and while compound is still warm, put on the square sealing washers and press them down so that the holes in the washers fit closely around the octagonal part of the posts. THE EVEREADY STORAGE BATTERY It is claimed by the manufacturers that the sulphate which forms in the Eveready battery during discharge always remains in the porous, convertible form, and never crystallizes and becomes injurious, even though the battery is allowed to stand idle on open circuit for a considerable length of time. Due to this fact, the Eveready battery is called a "Non-Sulphating Battery." The manufacturers state that Eveready batteries which have stood idle or in a discharged condition for months do not suffer the damages which usually result from such treatment, namely: buckling, and injurious sulphation. The plates do become sulphated, but the sulphate remains in the porous, non-crystalline state in which it forms. Charging such a battery at its normal rate is all that is necessary to bring it back to its normal, healthy condition. Due to the excessive amount of sulphate which forms when the battery stands idle or discharged for a long time, it is necessary to give the battery 50 percent overcharge to remove all the sulphate and bring the battery back to a healthy working condition. The colors of the plates are good guides as to their condition at the end of the charge. The positives should be free from blotches of white sulphate, and should have a dark brown or chocolate color. The negatives should have a bright gray or slate color. Description of Parts Eveready plates are of two general types. Plates of the R type are each provided with two feet on lower ends, the positive set and the negative set resting on two separate pairs of bridges in the jars, thereby preventing the sediment which accumulates on top of bridges from short circuiting a cell. Plates of the M type, instead of having feet, are cut away where they pass over the bridges of the opposite group. See Fig. 261. This construction secures a greater capacity for a given space, and gives the same protection against short circuit from sediment as the foot construction does, since the same amount of sediment must accumulate with either type of plate to cause a short circuit. [Fig. 261 Type "M" Eveready grid] The separators used in Eveready batteries are made of cherry wood because it is a hard wood which will resist wear, is of uniform texture, even porosity, and has a long life in a given degree and condition of acid. Eveready cherry wood separators go to the repair man in a dry condition, as they do not require chemical treatment. Separators when received should be soaked in 1.250 specific gravity acid for four days or longer in order to expand them to proper size and remove natural impurities from the wood. After being fully expanded they should be stored moist as previously described. Stock separators may be kept indefinitely in this solution and can be used as required. Fig. 262 shows the top construction in the Eveready battery. [Fig. 262 Eveready Battery, cell connectors covered by compound] Cell connectors are heavily constructed and are sealed over solidly with a flexible sealing compound, Fig. 262. Two types of cell connectors are used-the crescent and the heavy or "three way" type. Repairing Eveready Batteries To properly open and re-assemble an Eveready battery, proceed as follows: 1. Take a hot putty knife and cut the compound from the top of each of the inter-cell connectors until the entire top of the connector is exposed. 2. Center punch tops of cell connectors and terminal posts. 3. Drill off cell connectors. In drilling off crescent cell connector use 1/2 inch drill, and for heavy type connector use 5/8 inch drill. Drill deep enough, usually 3/8 to 1/2 inch, until a seam between connector and post is visible around lower edge of hole. Having drilled holes in both ends of connector, heat connector with soft flame until compound adhering to it becomes soft. Then take a 1/2 inch or 5/8 inch round iron or bolt, depending on connector to be removed, insert in one of the holes, and pry connector off with a side to side motion, being careful not to carry this motion so far as to jam connector into top of jar. 4. After connectors have been removed, steam and open the battery, as described on pages 332 to 335. 5. Examine plates, and handle them as described on pages 335 to 355. Remember, however, that Eveready plates which show the presence of large amounts of sulphate, even to the extent of being entirely covered with white sulphate, should not be discarded. A battery with such plates should be charged at the normal rate, and given a 50 percent overcharge. 6. Before re-assembling plate groups preparatory to assembling the battery, take negative and positive plate groups and build up the posts with the aid of a post builder to their original height. Assemble groups in usual manner, taking care that posts on straps are in proper position relative to group in adjoining cell, so that cell connectors will span properly. Eveready batteries use a right and left hand strap for both positive and negatives, making it necessary to use only one length of cell connector. 7. After inserting assembled plate groups into battery in their proper relation as to polarity, heat rubber covers to make them fairly pliable and fit them over posts and into top of jar, pressing them down until they rest firmly on top of plate straps. See that covers are perfectly level and that vent tubes are perpendicular and all at same height above the plates. 8. Heat compound just hot enough so that it will flow. Pour first layer about one quarter inch thick, being careful to cover entire jar cover. Take a soft flame and seal compound around edges of jar and onto posts. 9. Now proceed to burn on top connectors. Cell connectors need only be cleaned in hole left by post, and top of each end. 10. While burning in cell connectors the first layer of compound will have cooled sufficiently to permit the second layer to be applied. This should be done immediately after burning on connectors and while they are still hot. Also heat the terminal posts, as compound will adhere to hot lead more readily than to cold. Start second layer of compound by pouring it over cell connectors and terminal posts, first filling in with sufficient compound to bring level just above the tops of jars. Apply flame, sealing around edges of wood case, being particularly careful to properly seal terminal posts. Let this layer cool thoroughly before applying third layer. 11. The third layer of compound should be applied in the same way as second layer, pouring on connectors and terminal posts first, and filling in to the level of top of wood ease. The spaces between bars of cell connectors will fill and flow over properly if second layer has been allowed to cool and if cell connectors have not been burned up too high. In sealing last layer with flame, care should be taken not to play flame on compound too long as this hardens and burns the compound. Burned compound has no flexibility and will crack readily in service, thus causing the battery to become a "slopper." In pouring compound be sure to have battery setting level so that compound will come up even on all edges of case. Do not move battery after pouring last layer until thoroughly cool. Before installing battery on car be sure that no compound, etc., has been allowed to get onto taper of terminal post, as this will make a poor connection. If this has happened, clean with medium grade sandpaper. VESTA BATTERIES [Fig. 263 Vesta grid with 3-piece isolator] Vesta Isolators. The Vesta plate embodies in its design devices which are intended to hold the plates straight and thus eliminate the buckling and short-circuiting which form a large percentage of battery trouble. Fig. 263 shows clearly the construction of the old type of plate. Each isolator used in the old type of plate consists of two notched strips of celluloid, with a plain celluloid strip between them. The notches are as wide as the plates are thick, the teeth between the notches fitting into the spaces between plates, thus holding the plates at the correct distances apart. The plain celluloid strip holds the notched strips in place. At each corner of the Vesta plate is a slot into which the isolator fits, as shown in Fig. 263. Since the teeth on the two notched pieces of each isolator hold the plates apart, they cannot "cut-out" or "short-out" by pinching through the wooden separators, or "impregnated mats" as they are called by the Vesta Company. The celluloid of which the isolators are made are not attacked by the electrolyte at ordinary temperatures. At higher temperatures, however, the electrolyte slowly dissolves the isolators. The condition of the isolator, therefore, may be used to determine whether the temperature of the electrolyte has been allowed to rise above 100° Fahrenheit. The Vesta Type "D" Battery The appearance of a group of the new Type "D" construction is shown in Fig. 265, where Type "C" and Type "D" groups are illustrated side by side for purposes of comparison. It will be seen that the "D" isolator is of one piece only (shown separately in Fig. 266). The material is a heavy hard rubber stock which will be no more affected by acid or by electrical conditions in the cell than the hard rubber battery jar itself. The indentations on the two edges of isolator engage in hook shaped lugs on plate edges (Fig. 267 shows these clearly) and lock the plates apart fully as efficiently as the three-piece construction. [Fig. 264 Cross section, Vesta Isolator Battery, type C] There are a number of important advantages which have been gained by the new method of isolation. The illustration (Fig. 265) shows how the "D" isolator permits the separators to completely cover and project slightly beyond the edges of the plates, whereas in the old construction there is an edge just above the isolators where the plates are not covered. This improvement means protection against shorts due to flaking, always so likely to occur during the summer "overcharging" season. Overcharging is, of course, a form of abuse, and Type "D" batteries are designed to meet this sort of service. Another great advantage gained is in the arrangement of lugs, It will be noted that the positive isolator hooks are in alignment, as are the negative hooks, but that these two rows, of opposite polarity, are separated from each other by the full width of the isolator; whereas in the Type "C" construction the outer edges of the plates, of opposite polarity, were separated only by the usual distance between plates. [Fig. 265 Vesta elements: showing old 3-piece celluloid isolator and new one-piece hard rubber isolator] [Fig. 267 Vesta plates type U and DJ] [Fig.268 Inserting Vesta hard rubber isolator] The new isolator is simple to insert and remove. Being made of hard rubber, it will soften and become pliable if a sufficient degree of heat is applied. The heat required is approximately 150° to 160°F., a temperature far above that reached by any battery cell, even under the most extravagant condition of abuse, but readily attained in the shop by means of a small flame of any kind-even a match will do in an emergency. The flame (which should be of the yellow or luminous variety, as the blue flame tends to scorch the rubber) is played lightly over the isolator a few seconds. The rubber becomes soft and is then removed by inserting under the end of the isolator any narrow tool, such as a small screw driver, a wedge point, chisel, etc., and prying gently. In replacing isolators, a small hot plate is convenient but not at all necessary. The isolators are placed on the hot plate, or held in a luminous flame, until soft enough to bend. They are then bent into an arched shape, as shown in Fig. 268, and quickly fitted into place under the proper lugs. The regular isolator spacing tool is convenient and helpful in maintaining the plates at uniform intervals while this operation is carried out. The job is completed by pressing down the still warm isolator with any handy piece of metal having a flat edge that will fit the distance between the lugs (Fig. 269). The shank of a screw driver does splendidly for this work. The pressure causes the isolator to straighten out, and the indentations fit snugly under the respective hooks on the plates. At the same time the contact with the cold metal chills the rubber to its normal hard condition. It is especially to be noted that the entire operation of isolator removal and replacement can be carried out with none but the commonest of shop tools. [Fig. 269 Pressing down Vesta hard rubber isolator] [Fig. 270 Complete vesta battery] All of the "U" size batteries have been changed to Type "D," so that all "CU" types are superseded by corresponding "DU's." Type "D" will not be used on cells of sizes "L," "H," or "A", all of which remain of the "C" or three-piece isolator construction. Type "S" remains old style as before. Type "DJ" The Vesta Company has added a new plate size, produced in the "D" style (one-piece) isolator only, and known as "DJ." This plate is one-half inch higher than the "U," as shown in Fig. 267. It has 10 per cent more capacity. "DJ" batteries are available in all forms corresponding with "CU" types, and can be obtained by merely changing the type form name in ordering, as for example, to replace form 150, 6-DJ11-Y-150. The overall height of the completed battery is, of course, one-half inch more, and the "DJ" should therefore be ordered only when this additional height space is available in the battery compartment of the car. Vesta Separators The Vesta separators, or "mats," are treated by a special process. The Vesta Company considers its "mats" a very important feature of the battery. See page 15. Vesta Post Seal A lead collar fits over each post to hold the cover tight against the soft rubber gasket underneath. This collar is not screwed or burned on the post, but is simply pressed down over the post, depending for its holding power upon the fact that two lead surfaces rubbing against each other tend to "freeze," and unite so as to become a unit. The connector rests upon the upper race of the collar, and also helps to hold it down in its proper position. Fig. 270 shows the complete battery with the lead collar, and the large vent plug. In rebuilding Vesta batteries having the lead collars, the cover should be left in place when working on the plates, if possible. If, however, it is necessary to separate groups, and the lead collars must be removed, this is done as shown in Fig. 271. A few blows on the side of the collar with a light, two ounce hammer expands the lead collar several thousands of an inch so that the collar may be removed. [Fig. 271 Expanding lead collar of Vesta battery with light hammer] [Fig. 272 Placing soft rubber gasket over post of Vesta battery] In replacing the covers, the lead collar must be forced down over the post, and special pressure tongs are required for this purpose. Before driving on the old collar, the post should be expanded slightly by driving the point of a center-punch into the shoulder on the post. Instead of expanding the shoulder a new collar may be used. Fig. 272 shows the soft rubber gasket being placed over the post, and shows the construction of the cover with its recess to fit the gasket. Fig. 273 shows the lead collar being placed over the post after the cover is in place. Fig. 274 shows the special long lipped tongs required to force the collar down on the post shoulder. One lip of the tongs has a hole into which the post fits. The necessary driving force may be obtained by applying pressure to the ends of the lips of the tongs With an ordinary vise. This forces the cover down on the rubber gasket to make the acid-tight seal. [Fig. 273 Placing lead collar over post of Vesta battery] [Fig. 274 Pressing lead collar over post of Vesta battery] WESTINGHOUSE BATTERIES Westinghouse batteries have a special seal between covers and posts, as shown in Fig. 275. A lead foundation washer (J) is set around the post. A "U" shaped rubber gasket, (K) is then forced between the cover and post, with the open end up. The lips of this gasket are tapered, with the narrow edge up. A tapered lead sleeve (L) is then forced between the lips of gasket (K), thereby pressing the inner lip against the post and the outer lip against the cover. [Fig. 275 Westinghouse battery, partly dis-assembled] The lead sleeve is held in place by broaching or indenting the collar on taper lead sleeve into the posts. To break the seal, a hollow reamer or facing tool, fitted into a drill press or breast drill, is slipped over the post. A few turns will remove that part of the sleeve which has been forced into the post. Remove sealing compound around cover, remove group from cell. The cover can then be lifted off and if any difficulty is experienced, it can easily be removed by prying up cover with screwdriver. After removing the cover, the tapered lead sleeve and "U" shaped gasket can be removed. If these instructions are followed, the "U" shaped gasket and taper lead sleeves can be used when battery is reassembled. With the addition of the foregoing instructions on the post seal, the standard directions for rebuilding batteries given on pages 328 to 374 apply to Westinghouse batteries. Westinghouse Plates In any given size, the Westinghouse battery has two more plates per cell than the usual 1/8 inch plate battery. It has the same number of plates as the 3/32 inch thin plate battery, but the thickness of the plates is about half-way between the 1/8 inch and 3/32 inch plates. The Westinghouse negative grids, Fig. 276, have very few and small bars, just enough to hold the active material. It is slightly thinner than the positive but has the same amount of active material, due to the design of the grids. The condition of Westinghouse negatives should not be determined by cadmium readings as these plates may be fully charged and yet not give reversed cadmium readings. [Fig. 276 Westinghouse positive and negative plates] Aside from the special instructions given for the Westinghouse Post Seal, the Standard Instructions for Rebuilding Batteries, given on pages 328 to 374 may be used in rebuilding Westinghouse batteries. TYPES OF WESTINGHOUSE BATTERIES Type "A" Batteries The type "A" series was designed to fit the battery compartment in certain rather old models of cars. Owing to a lack of space this series is not of as efficient design as the "C" and "B" series. It does have the Westinghouse Post Seal, however. Type "A" batteries are not recommended for use when "B" or "C" batteries can be used. Ampere Hours Ampere Ampere Length Weight at Usual Rate for Rate for in Inches in Type Part No. Lighting Rate 20 Minutes 5 Hours L. Pounds ---- -------- ------------- ---------- -------- --------- ------ 6-A-11 100071 64 68 9.1 8 38 6-A-13 100072 79 82 11.0 9-1/8 42 6-A-15 100073 94 96 12.8 10-1/4 46 6-A-17 100074 109 109 14.6 11-9/16 52 6-A-21 100075 139 136 18.2 14-3/16 63 6-A-25 100076 169 164 22.0 17 75 12-A-7 100077 34 41 5.5 10-7/16 48 12-A-11 100078 64 68 9.1 14-15/16 70 12-A-17 100079 109 109 14.6 22-1/16 102 Plates Width Height Thickness ----- ------ --------- 5-5/8 4-1/8 .098 Type "B" Batteries The type "B" series of batteries has been designed for use on a number of cars now in service that do not have a sufficient headroom in the battery compartment for type "C." Type "B" batteries carry all of the features of the type "C." Due to the fact that the plates of necessity must be somewhat shorter than in the type "C" batteries their efficiency from the point of ampere hours per pound of weight is slightly less than the type "C" series. Ampere Hours Ampere Ampere Length Weight at Usual Rate for Rate for in Inches in Type Part No. Lighting Rate 20 Minutes 5 Hours L. Pounds ---- -------- ------------- ---------- -------- --------- ------ 6-B-7 100031 41 44 6.6 5-3/4 30 6-B-9 100032 59 66 8.8 6.7/8 36 6-B-11 100033 77 82 11.0 8 41 6-B-13 100034 95 99 13.2 9-1/2 47 6-B-15 100035 114 115 15.4 10-1/4 52 6-B-17 100036 132 131 17.6 11-9/16 57 6-B-19 100037 150 148 19.8 12-7/8 60 6-B-21 100038 168 164 22.0 14-3/16 68 6-B-23 100039 186 181 24.2 15-1/2 75 6-B-25 100040 205 197 26.4 17 82 12-B-7 100041 41 49 6.6 10-7/16 54 12-B-9 100042 59 66 8.8 12-11/16 66 12-B-11 100043 77 82 11.0 14-15/16 78 12-B-13 100044 95 99 13.2 17-3/16 91 12-B-15 100045 114 115 15.4 19-7/16 102 12-B-17 100046 132 131 17.6 22-1/16 113 Plates Width Height Thickness ----- ------ --------- 5-5/8 4-3/4 0.1 Type "C" Batteries The type "C" series of batteries is the Westinghouse standard. The outside dimensions and capacity are such that some one of this design may be used in a majority of cars now in service. The Westinghouse design was built around this type and it should be used for replacement or new equipment. Type "C" batteries are provided with the Westinghouse Post Seal wherever possible. Ampere Hours Ampere Ampere Length Weight at Usual Rate for Rate for in Inches in Type Part No. Lighting Rate 20 Minutes 5 Hours L. Pounds ---- -------- ------------- ---------- -------- --------- ------ 6-C-7 100001 45 54 7.3 5-7/8 34 6-C-9 100002 65 73 9.7 7 39 6-C-11 100003 85 91 12.1 8-1/8 44 6-C-13 100004 105 109 14.6 9-1/4 50 6-C-15 100005 125 127 17.0 10-3/8 56 6-C-17 100006 145 145 19.4 11-11/16 63 6-C-19 100007 165 163 21.8 13 70 6-C-21 100008 185 181 24.3 14-5/16 77 6-C-23 100009 205 199 26.7 15-5/8 85 6-C-25 100010 225 218 29.2 17-1/8 93 12-C-7 100011 45 54 7.3 10-9/16 59 12-C-19 100012 65 73 9.7 12-13/16 72 12-C-11 100013 85 91 12.1 15-1/16 84 12-C-13 100014 105 109 14.6 17-5/16 96 12-C-15 100015 125 127 17.0 19-8/16 110 Plates Width Height Thickness ----- ------ --------- 5-5/8 4-1/4 0.1 inch Type "E" Batteries The type "E" series was designed for replacement work on a few old model cars now in service where a narrow, high battery was necessary. The design is not as efficient as the "B" and "C" lines, due to a lack of space and further, it has been necessary to omit the Westinghouse Post Seal for the same reason. Ampere Hours Ampere Ampere Length Weight at Usual Rate for Rate for in Inches in Type Part No. Lighting Rate 20 Minutes 5 Hours L. Pounds ---- -------- ------------- ---------- -------- --------- ------ 6-E-13 100058 79 82 11.0 9-1/8 40 6-E-15 100062 94 96 12.8 10-1/4 44 6-E-17 100065 109 109 14.6 11-9/16 50 6-E-21 100067 139 136 18.2 14-3/16 62 12-E-11 100088 64 68 9.1 14-15/16 70 12-E-13 100060 79 82 11.0 17-3/16 79 12-E-15 100069 94 96 12.8 19-7/16 90 18-E-9 100070 49 54 7.3 15-5/16 75 Plates Width Height Thickness ----- ------ --------- 4-1/8 5-5/8 .098 Type "H" Batteries The type "H" battery is built with heavier plates than the type "C" and "B" batteries for use in cars where the necessary increased space is available and where the weight per ampere output is not a consideration. Under the same use the battery will give a greater life than the type "C" or "B" battery having the same positive area. This battery has a greater space between the plates than the "C" or "B" battery and will therefore have less internal discharge when standing on open circuit, and is more desirable for miscellaneous use where open circuit discharge is of consideration. Ampere Hours Ampere Ampere Length Weight at Usual Rate for Rate for in Inches in Type Part No. Lighting Rate 20 Minutes 5 Hours L. Pounds ---- -------- ------------- ---------- -------- --------- ------ 6-H-17 100089 61 74 9.9 7-3/4 35 6-H-9 100090 88 89 13.2 9-1/4 43 6-H-11 100091 115 124 16.5 11-1/2 55 6-H-13 100092 143 149 19.8 12-5/8 36 6-H-15 100093 170 173 23.2 14-5/16 70 6-H-17 100094 197 109 26.5 16 79 Plates Width Height Thickness ----- ------ --------- 5-5/8 5 .19 Type "J" Batteries The type "J" battery is an extremely heavy construction battery with thick plates, and it was designed primarily for use on trucks and other vehicles of this type where there is excessive vibration and other possibility of mechanical abuse. This battery will give a greater life than either the "H", "C" or "B" battery with the same plate area. It is provided with wood separators and rubber sheets. This battery has a greater space between the plates than the "C" or "B" battery and will therefore have less internal discharge when standing on open circuit, and is more desirable for miscellaneous use where open circuit discharge is of consideration. Ampere Hours Ampere Ampere Length Weight at Usual Rate for Rate for in Inches in Type Part No. Lighting Rate 20 Minutes 5 Hours L. Pounds ---- -------- ------------- ---------- -------- --------- ------ 6-J-5 100095 38 55 7.35 6-7/16 38 6-J-7 100096 68 82 11.0 8-1/8 40 6-J-9 100097 98 110 14.7 10-3/8 50 6-J-11 100098 128 137 18.4 11-7/8 60 6-J-13 100099 159 165 22.1 13-3/4 69 6-J-15 100100 189 192 25.7 15-5/8 84 6-J-17 100101 220 220 29.4 17-1/2 96 Plates Width Height Thickness ----- ------ --------- 5-5/8 5 .19 Type "0" Batteries The "0" type battery sacrifices some capacity in obtaining a rugged strength. It is a special battery made only with nineteen plates per cell where the percentage of sacrificed capacity is not great as compared with the twenty-one plate "C" type. It fills the same space as does a 6-C-21. It has greater life and strength. It has less capacity but it is built for conditions requiring less capacity than a twenty-one plate cell. Ampere Hours Ampere Ampere Length Weight at Usual Rate for Rate for in Inches in Type Part No. Lighting Rate 20 Minutes 5 Hours L. Pounds ---- -------- ------------- ---------- -------- --------- ------ 6-O-19 100143 185 185 24.5 13-11/16 68 Plates Width Height Thickness ----- ------ --------- 5-5/8 5-1/4 .123 Type "F" Batteries There is only one type "F" battery. It is of big heavy construction exactly the same dimensions as the battery used for a number of years on the Cadillac and certain other cars. This battery is heavier than type "C" of the same capacity and it has a greater life. Ampere Hours Ampere Ampere Length Weight at Usual Rate for Rate for in Inches in Type Part No. Lighting Rate 20 Minutes 5 Hours L. Pounds ---- -------- ------------- ---------- -------- --------- ------ 6-F-13 100086 150 160 21.2 17-11/16 79 Plates Width Height Thickness ----- ------ --------- 4-3/4 5-1/4 .17 WILLARD BATTERIES Since 1912, when the Willard Storage Battery Co. began to manufacture storage batteries for starting and lighting work, various types of Willard batteries have been developed. The original Willard starting and lighting batteries used two-piece, or "double" covers. These are shown in the cuts used to illustrate the sealing of double-cover covers in the preceding chapter, and no further description will be given here. The doublecover batteries are no longer made, but the repairman will probably be called upon to repair some of them. The instructions given in the preceding chapter should be used in making such repairs. Following the double cover batteries came the single cover battery, of which a number of types have been made. One type used a rectangular post, and was very difficult to repair. Fortunately, this type was not used extensively, and the battery is obsolete. Willard Batteries With Compound Sealed Posts The oldest type single-cover Willard battery which the repairman will be called upon to handle is the compound sealed post type, illustrated in-Fig. 277. This battery includes types SEW, SER, SJW, SL, SLR, SM, SMR, STR, SXW, SXR, SP, SK, SQ, EM, and EMR. As shown in Fig. 277, there is a well around each post which is filled with: sealing compound. On the under side of the cover is a corresponding well which fits into the post well, the sealing compound serving to make the seal between the cover and the post. [Fig. 277 Willard Battery cross section] Aside from this post seal, no special instructions are required in rebuilding this type of Willard battery. A 3/4 inch drill is needed for drilling off the connectors. When the plates have been lifted out of the jars, and are resting on the jar to drain, and while the compound and cover are still hot, remove the cover by placing your fingers under it and pressing down on the posts with your thumbs. With a narrow screw driver or a knife, clean out all of the old compound from the wells around the posts, and also remove the compound from the under side of the cover which fits into the post wells. In reassembling the battery first try on the covers to see that they will fit in the post wells. Then remove the covers again and heat them with a soft flame. Then heat the post wells perfectly dry with a soft flame. Pour the post wells nearly full of compound, and quickly press the cover into position. Willard Batteries With Lead Inserts In Covers The types SJWN and SJRN Willard batteries have lead inserts in the cover post holes, as shown in Mg. 278, the inserts being welded to the posts. For removing the connectors and for separating the post from the cover insert, the Willard Company furnishes special jigs and forms. The work may also be done without these jigs and forms, as will be described later. When the special jigs and forms are used, the work is done, as follows: 1. Place Willard drill jig Z-72 (Fig. 279) over the connector, and with a 13/16 inch drill, bore down far enough to release the connector from the post (Fig. 279). [Fig. 278 lead insert used on Willard Batteries; Fig. 279 Willard Drill Jig Z-72; Fig. 279 Willard Drill Jig Z-72 and how it is used] 2. File off the post stub left by drilling. This will give a flat surface on top of the cover insert and will make it easier to center the drill for the next operation. 3. With a 57/64 inch drill, and Willard jig Z-94 (Fig. 280), drill down to release the post from the cover insert. [Fig. 280 Willard Jig Z-94; Fig. 281 Willard Post-Builder Z-93] 4. In reassembling, build the post up to a height of 1-5/16 inches above the top of the plate strap, using Willard post builder Z-93 (Fig. 281). 5. After removing the post builder, bevel the top edge of the post with a file, as indicated at "A" (Fig. 281). Then replace plates in the jars. 6. File off tops of cover inserts at "A" (Fig. 282), to a height of 3/16 inch above the cover. Also remove any roughness on surface "B" caused by pliers when cover was removed. [Fig. 282 Willard Battery cross section of cover insert; Fig. 283 Willard burning form Z-87 and how it is used] 7. Put on the covers so that their tops will be 1/32 inch above the top edge of the jars, tapping them lightly with a small hammer. 8. Place Willard burning form Z-87 (Fig. 283) over the post and cover insert and burn the post to the insert. 9. Remove form Z-87 and thoroughly brush off the top of the post stub. Then build up the stub post, using Willard burning form Z-88 on the positive posts and form Z-89 on the negative posts (Fig. 284). [Fig. 284 Willard burning forms Z-88 and Z-89] 10. Now seal the covers with sealing compound as usual, and burn on the connectors. 11. If the terminal posts are made for clamp terminals, build up the posts by using Willard burning form Z-90, for the positive posts and Z-91 for the negative posts (Fig. 285). [Fig. 285 Willard burning forms Z-90 and Z-91] To work on the post seals of Willard types SJWN and SJRN without the special Willard jigs and forms: 1. Remove the connectors and terminals as usual. 2. Saw off the posts close to the covers, taking care not to injure the covers; This will separate the posts from the cover inserts, and the covers may be removed. 3. In reassembling, Ale off the top of the cover insert at "A" (Fig. 292). 4. Put covers on so that their tops will be 1/32 inch above the top edge of the jars, tapping the covers lightly with a small hammer. 5. Brush the top of post and cover insert perfectly clean. Now make a burning form consisting of a ring 1-1/8 inside diameter and 1-5/8 inch outside diameter and 3/16 to 1/4 inch high. Set this over the stub post and cover. With a hot lead burning flame melt the top of the post and cover insert together. Then melt in lead up to the top of the special burning form (Fig. 286). Then remove the form. [Fig. 286 Cross section Willard Battery Posts Types SJWN and SJRN] 6. Set post builders on the part of the posts which has been built up and build up the posts as usual, Fig. 286. Then burn on the connectors and terminals. Willard Gasket Type Batteries Fig. 287 shows this type of construction, used on types SJRG and SLWG. Fig. 288 shows the seal in detail. A soft rubber gasket is slipped over the post, and the cover is pushed down over the gasket. For removing the covers, have a cover removal frame made as shown in Fig. 289. Fasten the frame to a solid wall or bench so that it will withstand a strong pull. In rebuilding this type of battery proceed as follows: [Fig. 287 Willard Gasket Seal Battery cross section] 1. Drill off the connectors and terminals, leaving the post stubs, as high as possible, since the only way of removing the plates is by grasping the post stubs with pliers. [Fig. 288 Details of Willard Gasket Seal] 2. Steam the battery to soften the sealing compound and lift out the plates as usual. 3. To remove covers. Saw the post stubs off flush with the covers. Place the element in the cover removal frame (Fig. 289) and pull steadily on the element. A little swaying motion from side to side may help in loosening the covers. If any of the gaskets remain on the posts when the covers are removed, replace them in the cover and thoroughly dry the inside with a rag. [Fig. 289 Cover removal frame for Willard Gasket Seal Battery] 4. To replace covers. With a rag or tissue paper wipe off the posts and then dry them thoroughly with a soft flame. With a 3/4 inch bristle bottle brush apply a thin coating of rubber cement to the inside surfaces of the gaskets. Do this to one cover at a time and apply the cover quickly before the cement dries. The cement acts as a lubricant, and without it, it will be impossible to replace the covers. Willard Separators Fig. 290 shows the Willard Threaded Rubber Separator which is made of a rubber sheet pierced by thousands of threads which are designed to make the separator porous. This separator is not injured by allowing it to become dry, and makes it possible for the Willard Company to ship its batteries fully assembled without electrolyte or moisture, the parts being "bone-dry." [Fig. 290 Willard threaded rubber separator] UNIVERSAL BATTERIES Types. The Universal Battery Co. manufactures batteries for (a) Starting and Lighting, (b) Lighting, (c) Ignition, (d) Radio, (e) Electric Cars and Trucks, (f) Isolated, or Farm Lighting Plants, and (g) General Stationary Work. Construction Features. The Universal Starting and Lighting Batteries embody no special or unique constructions. The boxes are made of hard maple, lock cornered and glued. The jars have single rubber covers. The separators are made of Port Orford white cedar wood, this wood being the same as that used in some of the other standard makes of batteries. The space between the covers and connectors is sufficient to permit lifting the battery by grasping the connectors. [Fig. 291 Universal Battery Cover cross section] Fig. 291 shows the Universal Co. Post Seal construction. A soft rubber washer (A) is first slipped over the post. The cover (B) is then put in place, and rests on the washer (A) as shown. A second washer (C) is then slipped over the post, resting on the upper surface of the shoulder of the cover. The lead sleeve washer (D) is then forced down over the post, pressing washer (C) down on the cover, and pressing the cover down on washer (A). The two rubber washers serve to make a leak proof joint between post and cover. The lead sleeve-washer (D) "freezes" to the post, and holds cover and washers in position. In rebuilding Universal batteries the cover need not be removed unless it is desired to replace plate groups. To remove the cover, after the cell connectors have been drilled off, drill down through the post-stub until the drill has penetrated to the shoulder (E). This releases the seal and the cover may be lifted off. To save time, the post-stub may be cut off flush with the top of the cover with a hack saw after the cell connectors have been drilled off. The drill is then used as before to release the grip of the washer. Using a drill to release the grip of the washer makes it necessary to build up the posts when the battery is reassembled. Instead of using an ordinary twist drill, a special hollow drill may be obtained from the Universal Battery Co. This drill cuts away the lead sleeve gasket without injuring the post. If an ordinary drill is used, a 3/4 inch drill is required for the seven plate battery and a 13/16 inch drill for all other sizes. ONE-PIECE BATTERY CONTAINERS The standard practice in battery assembly has always been to place the plates of each cell in a separate, hard rubber jar, the jars being set in a wooden box or case. Each six-volt battery thus has four containers. When a wooden case is used, jars made of rubber, or some other nonporous, acid-resisting material are necessary. [Fig. 292 One-piece battery container] Wooden cases have been fairly well standardized as to the kinds of wood used, dimensions, constructional features, and to a certain extent, the handles. The disadvantage of both the wooden case and the iron handles is that they are not acid proof. Acid-proof paint protects them from the action of the acid to a certain extent, but paint is easily scraped off, exposing the wood and iron to the action of the acid. It is practically impossible to prevent acid from reaching the case and handles, and corroded handles and rotted cases are quite common. A recent development is a one-piece container which takes the place of the jars and wooden case. Such a container is made of hard rubber or a composition of impregnated fibre which uses a small amount of rubber as a binder. These cases are, of course, entirely acid proof, and eliminate the possibility of having acid soaked and acid rotted cases. Painting of cases is also eliminated. The handles are often integral parts of the case, as shown in Fig. 292, being made of the same material as the case. The repairman should not overlook the possibilities of the one-piece containers. In making up rental batteries, or in replacing old cases, the one-piece containers may be used to advantage. These containers are suitable for Radio batteries, since they have a neater appearance than the wooden cases, and are not as likely to damage floors or furnishings because the acid cannot seep through them. THE TITAN BATTERY The Titan Battery is built along standard lines, as far as cases, plates, separators, and jars are concerned. The ribs of the grids not arranged at right angles but are arranged as shown in Fig. 293. Each pellet of active material is supported by a diagonal rib on the opposite face of the grid. [Fig. 293a Titan Battery grid] [Fig. 293b Titan Post Seal construction] The Titan Post Seal is shown in Fig. 293. A soft rubber gasket (G) is slipped over the post, and rests on a shoulder (F) on the post. The cover has a channel which fits over the gasket and prevents the gasket from being squeezed out of place when the cover is forced down on the gasket. The post has two projections (DD), as shown, the lower surface of each of which is inclined at an angle to the horizontal. A lock nut (H), which has corresponding projections (IJ) is slipped over the post as shown at (0), and is given a quarter turn. The top surfaces of the projections on the lock-nut are inclined and as the locknut is turned, the projections on the post and nut engage, and the cover is forced down on the gasket (G). To lock the nut in place, a lock washer (L) is then slipped over the post, the projections (MM) fitting into spaces (KK) between the projections on the post and nut, thus preventing the nut from turning. A special wrench is furnished for turning the lock-nut. The cell connectors rest on the tops of the lock washers and keep them in place. The overhauling of Titan batteries should be done as described on pages 328 to 374. ======================================================================== SECTION 3. ======================================================================== CHAPTER 17. FARM LIGHTING BATTERIES SPECIAL INSTRUCTIONS. -------------------------------------------- Although the large Central Station Companies are continually extending their power lines, and are enlarging the territory served by them, yet there are many places where such service is not available. To meet the demand for electrical power in these places, small but complete generating plants have been produced by a number of manufacturers. These plants consist of an electrical generator, an engine, to drive the generator, and a storage battery to supply power when the generator is not running. The complete plants are called "House Lighting," "Farm Lighting," or "Isolated" plants. The batteries used in these plants differ considerably from the starting batteries used on automobiles. The starting battery is called upon to deliver very heavy currents for short intervals. On the car the battery is always being charged when the car is running at a moderate speed or over. The battery must fit in the limited space provided for it on the car, and must not lose any electrolyte as the car jolts along over the road. It is subjected to both high and low temperatures; and is generally on a car whose owner often does not know that his car has such a thing as a battery until his starting motor some day fails to turn over the engine. All starting batteries have wooden cases (some now use rubber cases), hard rubber jars, and sealed on covers. The case contains all the cells of the battery. Automobile batteries have, therefore, become highly standardized, and to the uninformed, one make looks just like any other. Farm lighting batteries, on the other hand, are not limited as to space they occupy, are not subjected to irregular charging and discharging, do not need leak proof covers, and are not called upon to delivery very heavy currents for short periods. These facts are taken advantage of by the manufacturers, who have designed their farm lighting batteries to give a much longer life than is possible in the automobile battery. As a result the farm lighting battery differs from the automobile battery in a number of respects. Jars. Both glass and rubber are used for farm lighting battery jars, and they may or may not have sealed-in covers. Fig. 294 shows a glass jar of an Exide battery having a hard rubber cover, and Fig. 295 shows a Prest-O-Lite glass jar cell having a cover made of lead and antimony. Unsealed glass jars, such as the Exide type shown in Fig. 324, generally have a plate of glass placed across the top to catch acid spray when the cell is gassing. Each jar with its plates and electrolyte forms a complete and separate unit which may easily be disconnected from the other cells of the battery by removing the bolts which join them. In working on a farm lighting battery, the repairman, therefore, works with individual cells instead of the battery as a whole, as is done with automobile batteries. [Fig. 294 Exide "Delco Light" farming lighting cell with hard rubber cover] Batteries with sealed jars are generally shipped completely assembled and filled with electrolyte, and need only a freshening charge before being put into service, just as automobile batteries which are shipped "wet" are in a fully charged condition when they leave the factory and need only a charge before being installed on the car. [Fig. 295 Prest-O-Lite farm lighting cell with lead-antimony cover] Jars that are not sealed are set in separate glass trays filled with sand, or sometimes the entire battery is set in a shallow wooden box or tray filled with sand. This is necessary because the absence of a sealed cover allows acid spray to run down the outside of the jar and this acid would, of course, attack the wooden shelf and make a dirty, sloppy battery. Batteries using jars without sealed covers cannot be shipped assembled and charged, and hence they require a considerable amount of work and along initial charge to put them in a serviceable condition. [Fig. 296 Exide farm lighting cell with sealed glass jar] Farm lighting battery jars are less liable to become cracked than those of automobile batteries because they are set in one place and remain there, and are not jolted about as automobile batteries are. Cracked jars in farm lighting batteries are more easily detected as the jar will be wet on the outside and the acid will wet the shelf or sand tray on which the jar rests. Batteries with sealed rubber jars are normally assembled four cells in a case or tray, with a nameplate on each tray which gives the type and size of cell. The cells are connected together with lead links which are bolted to the cell posts by means of lead covered bolt connectors. [Fig. 297 Combination wood and rubber separator used in Delco-Light and Exide Farm light cell] Plates. Since farm lighting batteries are not required to deliver very heavy currents at any time, the plates are made thicker than in starting batteries, this giving a stronger plate which has a longer life than the starting battery plate. All makes of starting batteries use the Faure, or pasted plate. This type of plate is also used in many farm lighting batteries, but the Plante plate (see page 27) may also be used. The Exide "Chloride Accumulator" cell, Fig. 323 uses a type of positive plate called the "Manchester" positive as described on page 497. Separators. Grooved wooden separators are used in some farm lighting batteries, while others use rubber separators, or both rubber and wooden separators. Some use wooden separators which are smooth on both sides, but have dowels pinned to them. Electrolyte. In a starting battery the specific gravity of the electrolyte of a fully charged cell is 1.280-1.300, no matter what the make of the battery may be. In farm lighting batteries, the different types have different values of specific gravity when fully charged. The usual values are as follows: (a) Batteries with sealed glass jars 1.210 to 1.250 (b) Batteries with open glass jars 1.200 to 1.250 (c) Batteries with sealed rubber jars 1.260 to 1.280 A brief discussion of specific gravity might be helpful at this point. In any lead acid battery current is produced by a chemical action between the active material in the plates and the water and sulphuric acid in the electrolyte. The amount of energy which can be delivered by the battery depends on the amount of active material, sulphuric acid, and water which enter into the chemical actions of the cell. As these chemical actions take place, sulphuric acid is used up, and hence there must be enough acid contained in the electrolyte to enter into the chemical actions. The amount of water and acid in the electrolyte may be varied, as long as there is enough of each present to combine with the active material of the plates so as to enable the cell to deliver its full capacity. Increasing the amount of acid will result in the plates and separators being attacked and injured by the acid. Increasing the amount of water dilutes the acid, giving a lower gravity, and preventing the Acid from injuring plates and separators. This results in a longer life for the battery, and is a desirable condition. In starter batteries, there is not enough space in the jars for the increased amount of water. In farm lighting batteries, where the space occupied by the battery is not so important, the jars are made large enough to hold a greater amount of water, thus giving an electrolyte which has a lower specific gravity than in starting batteries. Take a fully charged cell of any starting battery. It contains a set of plates and the electrolyte which is composed of a certain necessary amount of acid and a certain amount of water. If we put the plates of this cell in a larger jar, add the same amount of acid as before, but add a greater amount of water than was contained in the smaller jar, we will still have a fully charged cell of the same capacity as before, but the specific gravity of the electrolyte will be lower. Charging Equipment. Automobile batteries are being charged whenever the car is running at more than about 10 miles per hour, regardless of what their condition may be. In farm lighting outfits, the charging is under the control of the operator, and the battery is charged when a charge is necessary. There is, therefore, very much less danger of starving or overcharging the battery. The operator must, however, watch his battery carefully, and charge it as often as may be necessary, and not allow it to go without its regular charge. The generator of a farm lighting outfit is usually driven by an internal combustion engine furnished with the outfit. The engine may be connected to the generator by a belt, or its shaft may be connected directly to the generator shaft. A switchboard carrying the necessary instruments and switches also goes with the outfit. The charging of farm lighting batteries is very much like the charging of automobile batteries on the charging bench, except that the batteries are at all times connected to switches, by means of which they may be put on the charging line. Some plants are so arranged that the battery and generator do not provide current for the lights at the same time, lights being out while the battery is charging. In others the generator and battery, in emergency, may both provide current. In others the lights may burn while the battery is being charged; in this case the battery is sometimes provided with counter-electromotive force cells which permit high enough voltage across the battery to charge it and yet limit the voltage across the lamps to prevent burning them out or shortening their life. In some cases the battery is divided into two sets which are charged in parallel and discharged in series. Relation of the Automobile Storage Battery Man to the Farm Lighting Plant. Owners and prospective owners of farm lighting plants generally know but little about the care or repair of electrical apparatus, especially batteries, which are not as easily understood as lamps, motors or generators. Prospective owners may quite likely call upon the automobile battery repair man for advice as to the installation, operation, maintenance, and repair of his battery and the automobile battery repairman should have little trouble in learning how to take care of farm lighting batteries. The details in which these batteries differ from starting batteries should be studied and mastered, and a new source of business will be opened. Farm lighting plants in the vicinity should be studied and observed while they are in good working order, the details of construction and operation studied, the layout of the various circuits to lamps, motors, heaters, etc., examined so as to become familiar with the plants. Then When anything goes wrong with the battery, or even the other parts of the plant, there will be no difficulty in putting things back in running order. Selection of Plant "Farm Lighting Plant" is the name applied to the small electric plant to be used where a central station supply is not available. Such a plant, of course, may be used for driving motors and heating devices, as well as operating electric lights, and the plant is really a "Farm Lighting and Power Plant." Make. There are several very good lighting plants on the market and the selection of the make of the plant must be left to the discretion of the owner, or whomever the owner may ask for advice. The selection will depend on cost, whether the plant will fill the particular requirements, what makes can be obtained nearby, on the delivery that can be made, and the service policy of the manufacturer. Type. Plants are made which come complete with battery, generator, engine, and switchboard mounted on one base. All such a plant requires is a suitable floor space for its installation. Other plants have all parts separate, and require more work to install. With some plants, the generator and engine may be mounted as a unit on one base, with battery and switchboard separate. The type of jar used in the battery may influence the choice. Jars are made of glass or rubber. The glass jars have sealed covers, or have no covers. The rubber jars generally have a sealed cover. The glass jar has the advantage that the interior may be seen at all times, and the height of the electrolyte and sediment may be seen and the condition of the plates, etc., determined by a simple inspection. This is an important feature and one that will be appreciated by the one who takes care of the battery. Jars with sealed covers, or covers which although not sealed, close up the top of the jar completely have the advantage of keeping in acid spray, and keeping out dirt and impurities. Open jars are generally set in trays of sand to catch electrolyte which runs down the outside walls of the jars. The open jars have the advantage that the plates are very easily removed, but have the disadvantage that acid spray is not kept in effectually, although a plate of glass is generally laid over part of the top of the jar, and that dirt and dust may fall into the jar. Size. The capacity of storage battery cells is rated in ampere hours, while power consumed by lights, motors, etc., is measured in watt hours, or kilowatt hours. However, the ampere hour capacity of a battery can be changed to watt hours since watt hours is equal to Watt hours = ampere hours multiplied by the volts If we have a 16 cell battery, each cell of which is an 80 ampere hour cell, the ampere hour capacity of the entire battery will be 80, the same as that of one of its cells, since the cells are all in series and the same current passes through all cells. The watt hour capacity of the battery will be 32 times 80, or 2560. The ampere hour capacity is computed for the 8 hour rate, that is, the current is drawn from the battery continuously for 8 hours, and at the end of that time the battery is discharged. If the current is not drawn from the battery continuously for 8 hours, but is used for shorter intervals intermittently, the ampere hour capacity of the battery will be somewhat greater. It seldom occurs that in any installation the battery is used continuously for eight hours at a rate which will discharge it in that time, and hence a greater capacity is obtained from the battery. Some manufacturers do not rate their batteries at the 8 hour continuous discharge rate but use the intermittent rate, thus rating a battery 30 to 40 percent higher. Rated in this way, a battery of 16 cells rated at 80 ampere hours at the 8 hour rate would be rated at 112 ampere hours, or 3584 watt hours. In determining the size of the battery required, estimate as nearly as possible how many lamps, motors, and heaters, etc., will be used. Compute the watts (volts X amperes), required by each. Estimate how long each appliance will be used each day, and thus obtain the total watt hours used per day. Multiply this by 7 to get the watt hours per week. The total watt hours required in one week should not be equal to more than twice the watt hour capacity of the battery (ampere hours multiplied by the total battery voltage) at the eight hour rate. This means that the battery should not require a charge oftener than two times a week. The capacity of a battery is often measured in the number of lamps it will burn brightly for eight hours. The watts consumed by motors, heaters, etc., may be expressed in a certain number of lamps. The following table will be of assistance in determining the size of the battery required: Watts Equivalent Number No. Type of Appliance Consumed of 20 Watt Lamps --- ----------------- -------- ----------------- 1 16 candle power, Mazda lamp 20 1 2 12 candle power, Mazda lamp 115 3/4 3 Electric Fan, small size 75 4 4 Small Sewing machine motor 100 5 5 Vacuum cleaner 160 8 6 Washing machine 200 10 7 Churn, 1/6 h.p. 200 10 8 Cream Separator, 1/6 h.p. 200 10 9 Water pump 1/6 h.p. 200 10 10 Electric water heater, small 350 18 11 Electric toaster 525 26 12 Electric stove, small 600 30 13 Electric iron 600 30 14 Pump, 1/2 h.p. 600 30 From the foregoing table we can determine the current consumption of the various appliances: Amps at 32 Amps at 110 No. Watts Volts Volts --- ----- ---------- ------------ 1 20 0.625 0.18 2 15 0.47 0.14 3 75 2.34 6.80 4 100 3.125 0.90 5 160 5.00 1.44 6 200 6.25 1.80 7 200 6.25 1.80 8 200 6.25 1.80 9 200 6.25 1.80 10 350 11.00 3.20 11 525 16.4 4.77 12 600 18.75 5.40 13 600 18.75 5.40 14 600 18.75 5.40 The following tables show how long the battery will carry various currents continuously: [Images: various charts/tables] Location of Plant The various appliances should be placed as near to each other as possible. The lights, of course, must be placed so as to illuminate the different rooms, barns, etc., but the power devices should be placed as close as possible to each other and to the plant. The purpose of this is to use as little wire as possible between the plant and the various appliances so as to prevent excessive voltage drop in the lines. Wiring The wires leading to the various appliances should be large enough so that not more than one or two volts are lost in the wires. To obtain the resistance of the wire leading to any appliance, use the following equation: Knowing the resistance of the wire, and the total length of the two wires leading from the plant to the appliance, the size of the wire may be obtained from a wiring table. Rubber insulated copper wire covered with a double braid should preferably be used, and the duplex wire is often more convenient than the single wire, especially in running from one building to another. Wiring on the inside of buildings should be done neatly, running the wires on porcelain insulators, and as directly to the appliance as possible. The standard rules for interior wiring as to fuses, soldering joints, etc., should be followed. Installation (See also special instructions for the different makes, beginning page 460.) The room in which the plant is installed should be clean, dry, and well ventilated. It should be one which is not very cold in winter, as a cold battery is very sluggish and seems to lack capacity. If possible, have the plant in a separate room in order to keep out dirt and dust. If no separate room is available, it is a good plan to build a small room in a corner of a large room. Keep the room clean and free of miscellaneous tools and rubbish. If the entire plant comes complete on one base, all that is necessary is to bolt the base securely to the floor, which should be as nearly level as possible. If the battery is to be installed separately, build a rack. Give the rack several coats of asphaltum paint to make it acid proof. The location of the battery rack should be such that the rack will be: (a) Free from vibration. (b) At least 3 feet from the exhaust pipe of engine. (c) Far enough away from the wall to prevent dirt or loose mortar from dropping on the cells. Figs. 298 and 299 illustrate two types of battery racks recommended for use with farm light batteries. The stair-step rack is most desirable where there is sufficient room for its installation. Where the space is insufficient to make this installation, use the two-tier shelf rack. The racks should be made from 1-1/2 or 2 inch boards. [Fig. 298 "Stair-Step" rack for farm lighting battery] The cells may be placed on the battery rack with either the face or the edges of the plates facing out. The latter method requires a shorter battery rack and is very desirable from the standpoint of future inspections. In very dark places, it is more desirable to have the surface of the plates turned out to enable the user to see when the cells are bubbling during the monthly equalizing charge. Either method is satisfactory. All metal parts such as pipes, bolt heads, etc., which are near the battery should be given at least three coats of asphaltum paint. Care must be taken not to have an open flame of any kind in the battery room, as the hydrogen and oxygen gases, given off as a battery charges may explode and cause injury to the person and possible severe damage to the battery. When making an installation, it is always a good plan to carry the following material for taking care of spillage and broken jars: 1. 1 Thermometer 2. 2 Series Cells 3. 6 Battery Bolts and Nuts 4. 1 Hydrometer Syringe 5. 2 Gallons distilled water 6. 1 Jar Vaseline 7. 1 Gallon 1.220 specific gravity electrolyte [Fig. 299 Installation of a Delco-Light plant, showing two-tier shelf rack for battery] When a battery arrives at the shipping destination, the person lifting this shipment should remove the slats from the top of each crate and inspect each cell for concealed damage, such as breakage: Should any damage be discovered, it is important that a notation covering this damage be made and signed by the freight agent on the freight bill. This will enable the customer or dealer to make a claim against the railroad for the amount of damage. If a notation of this kind is not made before the battery is lifted, the dealer will be forced to stand the expense of repairing or replacing the damaged cells. When removing cells from a crate, avoid lifting them by the terminal posts as much as possible. This causes the weight of the electrolyte and jar to pull on the sealing compound between the jar and cover, and if the sealing is not absolutely tight, the jar and electrolyte may fall from the cover. A cell should never be carried using the terminal posts as handles. The hand should be put underneath the jar. Sometimes a battery will arrive with electrolyte spilled from some of the cells. If spillage is only about one-half to one inch down on the plates of three or four cells, this spillage may be replaced by drawing a little electrolyte out of each cell of the other full cells in the set. Oftentimes several cells will have electrolyte extending above the water line, which will aid greatly in making up any loss in other cells. After all cells have been drawn on to fill up the ones that are spilled, the entire set may then have its electrolyte brought up to the water line by adding distilled water. Very carefully adjust spillage of pilot cells (Delco), as it is very important that the specific gravity of the pilot cells be left as near 1.220 as possible. In case the spillage is more than one inch below the top of plates or glass broken, remove cell and install a new cell in its place. The spilled or broken cell must not be used until given special treatment. Connecting Cells Before connecting up the cells the terminals should be scraped clean for about 11/2 inches on both sides. An old knife or rough file is suitable for doing this work. After the terminals are thoroughly brightened, they should be covered with vaseline. The bolts and nuts used in making the connections on the battery should also be coated with vaseline. The vaseline prevents and retards corrosion, which is harmful to efficient operation. If a new battery is to be installed in parallel with one already in service, connections should be made so that each series will consist of half new and half old cells. The pilot cells for the new battery should be placed in one series and that for the old battery in the other, unless local conditions may make some other arrangement desirable. A drop light must always be provided to enable the user to inspect his battery, particularly when giving the monthly equalizing charge. Initial Charge When a battery is connected to the plant, it should be given a proper INITIAL CHARGE before any power or lights are used. Batteries shipped filled with electrolyte are fully charged before leaving the factory. As soon as a storage battery cell of any type or make is taken off charge and stands idle for a considerable length of time, some of the acid in the electrolyte is absorbed by the plates, thereby lowering the gravity and forming sulphate on the plates. This process is very gradual, but it is continuous, and unless the acid is completely driven out of the plates by charging before the battery is used, the battery will not give as good service as the user has a right to expect. Due to the time required in shipment, the above action has a chance to take place, which makes it necessary to give the initial charge. The initial charge consists of charging the battery, with the power and light switch open, until each cell is bubbling freely from the top to bottom on the surface of the outside negative plates and both pilot balls are up (Delco-Light), and then CONTINUING THE CHARGE FOR FIVE HOURS MORE. If the battery has no pilot cells, measure the specific gravity of the electrolyte of each cell, and continue the charge until six consecutive readings show no increase in gravity. As an accurate check on giving the initial charge properly (Delco-Light), we strongly recommend that hourly hydrometer readings of both pilot cells be taken after both balls are up, the charge to be continued until six consecutive hourly readings show no RISE in gravity. Due to the fact that it is impossible to hold each cell in a battery to a definite maximum gravity when fully charged, there is likely to be a variation of from ten to fifteen points in the specific gravity readings of the various cells. It should be understood, however, that the maximum gravity is the gravity when the cells are fully charged and with the level of the solution at the water line. For example, with each cell in a battery fully charged and therefore at maximum gravity and with the level at the proper height, some cells may read 1.230, one or two 1.235, several 1.215 and 1.210. All of these cells will operate efficiently, and there should be no cause for alarm. An exception to this is the pilot cell of the Delco-Light Battery. If this check on the initial charge is properly made, it assures the service man and dealer that the battery is in proper operating condition to be turned over to the user. Negligence in giving the initial charge properly may result in trouble to both user, service man and dealer. The initial charge may require considerable running of the plant, depending upon the state of charge of the cells when installed. Instructing Users During the time the initial charge is being given, the service man should instruct the user on the care and operation of the plant and battery. The best way to give instructions to the user is to tack the instruction cards on the wall near the plant in a place where the user can read them easily. Proceed to read over the plant operating card with the user. Read the first item, go to the plant, explain this feature to the user and allow him to perform the operation, if the instruction calls for actual performance. Remember, the user is not familiar with the plant and battery, and the actual performance of each operation aids him to retain the instructions. After the first item has been covered thoroughly, proceed to the second, etc. During the course of instruction, the user will often interrupt with questions not dealing directly with the point being explained. The service man should keep the user's attention on the points he is explaining. When the service man has finished explaining both plant and battery instruction cards, he should answer any points in question which the user wants explained. When the monthly equalizing charge is explained to the user, the service man should always take the user to the battery and show him a cell bubbling freely. This is necessary in order that the user may recognize when the cells are bubbling freely at the time he gives the monthly equalizing charge. Impress upon the user the importance of inspecting each cell when giving the monthly equalizing charge to see that every cell bubbles freely. If a cell fails to bubble freely at the end of the equalizing charge, the user should inform the service man of this condition immediately. Caution the user against the use of an open flame near the plant or battery at any time. The gas which accumulates in a cell will explode sufficiently to break the glass jar if this gas is ignited by a spark or open flame. Care of the Plant in Operation (See also special instructions for the different makes, beginning page 460.) The battery repairman should be able not only to repair the batteries, but should also be able to keep the entire plant in working order, and suggestions will be given as to what must be done, although no detailed instructions for work on the generator, engine, and switchboard will be given as this is beyond the scope of this book. Battery Room. The essential things about the battery room are that it must be clean, dry, and well ventilated. This means, of course, that the battery and battery rack must also be kept clean and dry. A good time to clean up is when the battery is being charged. Clean out the room first, sweeping out dirt and rubbish, dusting the walls, and so on. Both high and low temperatures should be avoided. If the battery room is kept too hot, the battery will become heated and the hot electrolyte will attack the plates and separators. Low temperatures do no actual harm to a charged battery except to make the battery sluggish, and seem to lack capacity. A discharged battery will, however, freeze above 0° Fahrenheit. The battery will give the best service if the battery room temperature is kept between 60° and 80° Fahrenheit. Do not bring any open flame such as a lantern, candle or match near a battery and do not go near the battery with a lighted cigar, cigarette or pipe, especially while the battery is charging. Hydrogen and oxygen gases form a highly explosive mixture. An explosion will not only injure the battery, but will probably disfigure the one carrying the light, or even destroy his eyes. It is a good plan to keep the windows of the battery room open as much as possible. Engine. The engine which drives the generator requires attention occasionally. Wipe off all dirt, oil or grease. Keep the engine well lubricated with a good oil. If grease cups are used, give these several turns whenever the engine is run to charge the battery. Use clean fuel, straining it, if necessary, through a clean cloth or chamois, if there is any dirt in it. The cooling water should also be clean, and in winter a non-freezing preparation should be added to it. Do not change the carburetor setting whenever the engine does not act properly. First look over the ignition system and spark plug for trouble, and also make sure that the carburetor is receiving fuel. If possible, overhaul the engine once a year to clean out the carbon, tighten bearings and flywheel, remove leaky gaskets, and so on. Generator. Keep the outside of the generator clean by wiping it occasionally with an oiled rag. See that there is enough lubricating oil in the bearings, but that there is not too much oil, especially in the bearing at the commutator end of the generator. Keep the commutator clean. If it is dirty, wipe it with a rag moistened slightly with kerosene. The brushes should be lifted from the commutator while this is being done. Finish with a dry cloth. If the commutator is rough it may be made smooth with fine sandpaper held against it while the generator is running, and the brushes are lifted. The surfaces of the brushes that bear on the commutator should be inspected to see that they are clean, and that the entire surfaces make contact with the commutator. The parts that are making contact will look smooth and polished, while other parts will have a dull, rough appearance. If the brush contact surfaces are dirty or all parts do not touch the commutator, draw a piece of fine sandpaper back and forth under the brushes, one at a time, with the sanded side of the paper against the brush. This will clean the brushes and shape the contact surfaces to fit the curve of the commutator. Brushes should be discarded when they be come so short that they do not make good contact with the commutator. See that the brush holders and brush wires are all tight and clean. Watch for loose connections of wires, as these will cause voltage loss when the generator is charging the battery. Watch for "high mica," which means a condition in which the insulation between the segments projects above the surface of the commutator, due to the commutator wearing down faster than the insulation. If this condition arises, the mica should be cut down until it is slightly below the surface of the commutator. An old hack saw blade makes a good tool for this purpose. A commutator may have grooves cut in by the brushes. These grooves do no harm as long as the brushes have become worn to the exact shape of the grooves. When the brushes are "dressed" with sandpaper, however, they will not fit the grooves, and the commutator should be turned down in a lathe until the grooves are removed. A steady low hum will be heard when the generator is in operation. Loud or unusual noises should be investigated, however, as a bearing may need oil, the armature may be rubbing on the field pole faces, and so on. Watch for overheating of the generator. If you can hold your hand on the various parts of the generator, the temperature is safe. If the temperature is so high that parts may be barely touched with the hand, or if an odor of burned rubber is noticeable, the generator is being overheated, and the load on the generator should be reduced. Switchboard. Clean off dirt and grease occasionally. Keep switch contacts clean and smooth. If a "cutout" is on the board, keep its contacts smooth and clean. If the knife switch blades are hard to move, look for cutting at the pivots. Something may be cutting into the blades. If this is found to be the case, use a file to remove all roughness from the parts of the pivot. See that no switches are bent or burned. Keep the back of the board clean and dry as well as the front. See that all connections are tight. Keep all wires, rheostats, etc., perfectly clean. A coat of shellac on the wires, switch studs, etc., will be helpful in keeping these parts clean. Care of Battery Cleanliness. Keep the battery and battery rack clean. After a charge is completed, wipe off any electrolyte that may be running down the outsides of the jars. Wipe all electrolyte and other moisture from the battery rack. Occasionally go over the rack with a rag wet with ammonia or washing soda solution. Then finish with a dry cloth. Paint the rack with asphaltum paint once a year, or oftener if the paint is rubbed or scratched. If sand trays are used, renew the sand whenever it becomes very wet with electrolyte. Keep the terminals and connectors clean. Near the end of a charge, feel each joint between cells for a poor connection. Watch also for corrosion on the connections. Corrosion is caused by the electrolyte attacking any exposed metals other than lead, near the battery, resulting in a grayish deposit on the connectors or bolts at the joints. Such joints will become hotter than other joints, and may thus be located by feeling the joints after the battery has been charged for some time. Corrosion may be removed by washing the part in a solution of baking soda. Be very careful to keep out of the cells anything that does not belong there. Impurities injure a cell and may even ruin it. Do not let anything, especially metals, fall into a cell. If this is done accidentally, pour out the electrolyte immediately, put in new separators, wash the plates in water, fill with electrolyte having a gravity about 30 points higher than that which was poured out, and charge. The cell may be connected in its proper place and the entire battery charged. Vent plugs should be kept in place at all times, except when water is added to the electrolyte. Keep the Electrolyte Above the Tops of the Plates. If the battery has glass jars, the height of the electrolyte can be seen easily. If the battery has sealed rubber jars, the height of the electrolyte may be determined with a glass tube, as described on page 55. In most batteries the electrolyte should stand from three-fourths of an inch to an inch above the plates. Some jars have a line or mark showing the proper height of the electrolyte. A good time to inspect the height of the electrolyte is just before putting the battery on charge. If the electrolyte is low, distilled water should be added to bring it up to the proper level. Water should never be added at any other time, as the charging current is required to mix the water thoroughly with the electrolyte. Determining the Condition of the Cells. The specific gravity of the electrolyte is the best indicator of the condition of the battery as to charge, just as is the case in automobile batteries, and hence should be watched closely. It is not convenient or necessary to take gravity readings on every cell in the battery on every charge or discharge. Therefore, one cell called the "Pilot" cell should be selected near the center of the battery and its specific gravity readings taken to indicate the state of charge or discharge of the entire battery. Delco-Light batteries each have two pilot cells with special jars. Each of these has a pocket in one of its walls in which a ball operates as a hydrometer or battery gauge. One pilot cell contains the pilot ball for determining the end of the charge, and other pilot cell containing the ball for determining the end of the discharge. See Fig. 294. Hydrometer readings should be taken frequently, and a record of consecutive readings kept. When the gravity drops to the lowest value allowable (1.150 to 1.180, depending on the make of battery) the battery should be charged. Once every month voltage and gravity readings of every cell in the battery should be taken and recorded for future guidance. These readings should be taken after the monthly "overcharge" or "equalizing charge" which is explained later. If the monthly readings of any cell are always lower than that of other cells, it needs attention. The low readings may be due to electrolyte having been spilled and replaced with water, but in a farm lighting battery this is not very likely to happen. More probably the cell has too much sediment, or bad separators, and needs cleaning. See special instructions on Exide and Prest-O-Lite batteries which are given later. There are several precautions that must be observed in taking gravity readings in order to obtain dependable results. Do not take gravity readings if: (a) The cell is gassing violently. (b) The hydrometer float does not ride freely. If a syringe hydrometer is used, the float must not be touching the walls of the tube, and the tube must not be so full that the top of the float projects into the rubber bulb at the upper end of the tube. (c) Water has been added less than four hours before taking the readings. A good time to take readings is just before water is added. The hydrometer which is used should have the specific gravity readings marked on it in figures, such as 1.180, 1.200, 1.220 and so on. Automobile battery hydrometers which are marked "Full," "Empty," "Charged," "Discharged," must not be used, since the specific gravities corresponding to these words are not the same in farm lighting batteries as in automobile batteries and the readings would be incorrect and misleading. If the manufacturer-of the battery furnishes a special hydrometer which is marked "Full," "Half-Full," "Empty," or in some similar manner, this hydrometer may, of course, be used. Temperature corrections should be made in taking hydrometer readings, as described on page 65. For Prest-O-Lite batteries, 80 degrees is the standard temperature, and gravity readings on these batteries should be corrected to 80 degrees as described on page 461. Gravity readings should, of course, be taken during charge as well as during discharge. The readings taken during charge are described in the following sections on charging. Charging (See also special instructions for the different makes, beginning page 460.) Two kinds of charges should be given the battery, the "Regular" charge, and the "Overcharge" or "Equalizing Charge." These will be spoken of as the "Regular" charge and the "Overcharge." The Regular charge must be given whenever it is necessary in order to enable the battery to meet the lighting or other load demands made upon it. The overcharge, which is merely a continuation of a regular charge, should be given once every month. The overcharge is given to keep the battery in good condition, and to prevent the development of inequalities in condition of cells. When to Charge. Experience will soon show how often you must give a regular charge in order to keep the lights from becoming dim. When the voltage reading, taken while all the lamps are on has dropped to 1.8 volts per cell a Regular charge is necessary. When the specific gravity of the pilot cell indicates that the battery is discharged, a Regular charge is necessary. It is better to use the specific gravity readings as a guide, as described later. A good plan, and the best one, is to give a battery a Regular charge once every week, whether the battery becomes discharged in one week's time or not. A regular charge may be required oftener than once a week. Every fourth week give the Overcharge instead of the Regular charge. If a battery is to be out of service, arrangements should be made to add the necessary water and give an overcharge every month, the Regular charges not being necessary when the battery stands absolutely idle. Overcharge. Charge the battery as near as practicable at the rate prescribed by the manufacturer. If the manufacturer's rate is not known, then charge at a rate which will not allow the temperature of the electrolyte to rise above 110° Fahrenheit, and which will not cause gassing while the specific gravity is still considerably below its maximum value. One ampere per plate in each cell is a safe value of current to use. A battery having eleven plates in each cell should, for example, be charged at about 11 to 12 amperes. Watch the temperature of the pilot cell carefully. This cell should have an accurate Fahrenheit thermometer suspended above it so that the bulb is immersed in the electrolyte. If this thermometer should show a temperature of 110°, stop the charge immediately, and do not start it again until the temperature has dropped to at least 90'. Feel the other cells with your hand occasionally, and if any cell is so hot that you cannot hold your hand on it measure its temperature with the thermometer to see whether it is near 110'. A good plan is to measure the temperature of the electrolyte in every cell during the charge. If any cell shows a higher temperature than that of the pilot cell, place the thermometer in the cell giving the higher reading, and be guided by the temperature of that cell. You will then know that the thermometer indicates the highest temperature in the entire battery, and that no other cell is dangerously hot when the thermometer does not read 100 degrees or over. Another point in the selection of a pilot cell is to determine if any particular cell shows a gravity which is slightly less than that of the other cells. If any such cell is found, use that cell as the pilot cell in taking gravity readings while the battery is on discharge and also on charge. No cell will then be discharged too far. When all cells are gassing freely, continue the charge at the same current until there is no rise in the specific gravity of the pilot cell for one to two hours, and all cells are gassing freely throughout the hour. Then stop the charge. After the overcharge is completed, take gravity readings of all the cells. A variation of about eight to ten points either above or below the fully charged gravity after correction for temperature does not mean that a cell requires any attention. If, however, one cell continually reads more than 10 points lower then the others, the whole battery may be given an overcharge until the gravity of the low cell comes up. If the cell then does not show any tendency to charge up properly, disconnect it from the battery while the battery is discharging and then connect it in again on the next charge. If this fails to bring the gravity of the cell up to normal, the cells should be examined for short circuits. Short circuits may be caused by broken separators permitting the active material to bridge between the plates; the sediment in the bottoms of the jars may have reached the plates, or conducting substances may have fallen in the cells. Broken separators should be replaced without loss of time, and the cells cleaned if the sediment in the jars is high. Regular Charge. A Regular Charge is made exactly like an Overcharge, except that a Regular Charge is stopped when cells are gassing freely, when the voltage per cell is about 2.6, and when the specific gravity of the pilot cell rises to within 5 points of what it was on the previous Overcharge. That is, if the gravity reading on the Overcharge rose to 1.210, the Regular Charge should be stopped when the gravity reaches 1.205. Partial or Rapid Charge. If there is not enough time to give the battery a full Regular Charge, double the normal charging rate and charge until all the cells are gassing, and then reduce to the normal rate. Any current which does not cause excessive temperature or premature gassing is permissible, as previously mentioned. If a complete charge cannot be given, charge the battery as long as the available time allows, and complete the charge at the earliest possible opportunity. Discharge Do not allow the battery to discharge until the lights burn dim, or the voltage drops below 1.8 per cell. The specific gravity is a better guide than the lamps or voltage. The gravity falls as the battery discharges, and is therefore a good indicator of the condition of the battery. Voltage readings are good guides, but they must be taken while the battery is discharging at its normal rate. If the load on the battery is heavy, the voltage per cell might fall below 1.8 before the battery was discharged. Lamps will be dim if the load on the battery is heavy, especially if they are located far away from the battery. The specific gravity readings are therefore the best means of indicating when a battery is discharged. Overdischarge. Be very careful not to discharge the battery beyond the safe limits. Batteries discharging at low rates are liable to be overdischarged before the voltage gives any indication of the discharged condition. This is another reason why hydrometer readings should be used as a guide. A battery must be charged as soon as it becomes discharged. It is, in fact, a good plan, and one which will lengthen the life of the battery, to charge a battery when it is only about three fourths discharged, as indicated by the hydrometer. Suppose, for instance, that the specific gravity of the fully charged battery is 1.250, and the specific gravity when the battery is discharged is 1.180. This battery has a range of 1.250 minus 1.180, or 70 points between charge and discharge. This battery will give a longer life if its discharge is stopped and the battery is put on charge when the gravity falls to 1.200, a drop of 50 points instead of the allowable 70. Allowing discharged battery to stand without charge. A battery should never be allowed to stand more than one day in a discharged condition. The battery will continue to discharge although no current is drawn from it, just as an automobile battery will. See page 89. The battery plates and separators will gradually become badly sulphated and it will be a difficult matter to charge the battery up to full capacity. Battery Troubles Farm lighting batteries are subject to the same general troubles that automobile batteries are, although they are not as likely to occur because the operating conditions are not as severe as is the case on the automobile. Being in plain view at all times, and not being charged and discharged irregularly, the farm lighting battery is not likely to give as much trouble as an automobile battery. Neglect, such as failure to keep the electrolyte up to the proper height, failure to charge as soon as the battery becomes discharged, overdischarging, allowing battery to become too hot or too cold, allowing impurities to get into the cells, will lead to the same troubles that the same treatment will cause in an automobile battery, and the descriptions of, and instructions for troubles in automobile batteries will apply in general to farm lighting batteries also. When a battery has been giving trouble, and you are called: upon to diagnose and remedy that trouble, you should: 1. Get all the details as to the length of time the battery has been in service. 2. Find out what regular attention has been paid to its upkeep; whether it has been charged regularly and given an overcharge once a month; whether distilled water has been used in replacing evaporation of water from the electrolyte; whether impurities such as small nails, pieces of wire, etc., have ever fallen into any cell; whether battery has ever been allowed to stand in a discharged condition for one day or more; whether temperature has been allowed to rise above 110 deg. F. at any time; whether electrolyte has ever been frozen due to battery standing discharged in very cold weather. 3. Talk to the owner long enough to judge with what intelligence he has taken care of the battery. Doing this may, save you both time and subsequent embarrassment from a wrong diagnosis resulting from incomplete data. 4. After getting all the details that the owner can supply, you will probably know just about what the trouble is. Look over the cells carefully to determine their condition. If the jars are made of glass note the following: (a) Height of sediment in each jar. (b) Color of electrolyte. This should be clear and colorless. A decided color of any kind usually means that dirty or impure water has been added, or impurities have fallen into the cell. For discussion of impurities see page 76. (c) Condition of plates. The same troubles should be looked for as in automobile batteries. See pages 339 to 346. An examination of the outside negatives is usually sufficient. The condition of the positives may also be determined if a flash light or other strong light is directed on the edges of the plates. Look for growths or "treeing" between plates. (d) Condition of separators. See page 346. If cells have sealed rubber jars, proceed as follows: (a) Measure height of electrolyte above plates with glass tube, as in Fig. 30. If in any cell electrolyte is below tops of plates that cell is very likely the defective one, and should be filled with distilled water. If a considerable amount of water is required to fill the jar it is best to open the cell, as the plates have probably become damaged. If the jar is wet or the rack is acid eaten under the jar, the jar is cracked and must be replaced. If you have not found the trouble, make the following tests, no matter whether glass or rubber jars are used: (a) Measure specific gravity of each cell. If any cell is badly discharged it is probably short-circuited, or contains impurities and had better be opened for inspection. (b) Turn on all the lamps and measure the voltage of each cell. If any cell shows a voltage much less than 1.8 it is short-circuited or contains impurities, and should be opened for inspection. (c) Examine the connections between cells for looseness or corrosion; and examine the connections between the battery and the generator, going over cables, switches, rheostats, etc. Make sure that you have a complete and closed charging circuit between the generator and the battery. (d) If cutout is used on the switchboard, see that its contact points are smooth and clean, and that they work freely. (e) Run the generator to see if it builds up a voltage which is sufficient to charge the battery, about 42 volts for a 16 cell battery. If the generator is not working properly, examine it according to directions on page 451. Check up the field circuit of the generator to be sure that it is closed. A circuit-tester made of a buzzer and several dry cells, or a low voltage lamp and dry cells, or a hand magneto is convenient for use in testing circuits. Test armature windings and field coils for grounds. By the foregoing methods you should be able to determine what is to be done. The following rules should also help: Cleaning and renewal of electrolyte is necessary when: (a) Sediment has risen to within one-half inch of the bottom of the plates. (b) Much foreign material is floating in the electrolyte, or electrolyte is of a deep brown color. Replacement of parts is necessary when (a) Separators are cracked or warped. See page 346 for Separator troubles. (b) Plates are defective. See rules on pages 339 to 346. PREST-O-LITE FARM LIGHTING BATTERIES [Fig. 300 Element from Prest-O-Light farm light cell] The Prest-O-Lite battery which is designed for use in connection with farm lighting plants is known as the FPL type. Cells of 7, 9, 11, 13 and 15 plates are made, the number of plates being indicated by putting the figure in front of the type letters. A seven plate cell is thus designated as a 7 FPL cell, which has an 80 ampere hour capacity at the 8 hour continuous discharge rate. The FPL cell, the construction of which is shown in Figs. 295, 300, 301, 302 and 303, has a sealed glass jar with a lead antimony cover. The cover construction is shown in detail in Figs. 301 and 302. Insulation between the posts and cover is provided by a hard rubber bushing, a hard rubber washer, and a soft rubber washer. The bushing is shaped like a "T" with a hole drilled in the stem. The stem of the bushing fits down into the post hole in the cover, the flange at the top testing on the raised portion of the cover around the post hole. The post has a shoulder a little less than halfway up from its lower end. Upon this shoulder is placed the hard rubber washer, and upon the hard rubber washer is placed the soft rubber washer. This assembly is fastened to the cover by the "peening" process used in Prest-O-Lite automobile batteries as described on page 386. This forces the soft rubber washer tightly against the cover so as to make a leak proof joint-between the bushing and cover. The ring of lead formed around the posts by the peening process supports the posts, plates, and separators, which therefore are suspended from the cell cover. The plate straps extend horizontally across the tops of the plates, and thus also act as "hold-downs" for the separators. The separators are held up by two rectangular rubber bridges which fit Mito slotted extension lugs cast into the lower corners of the outside negative plates. An outside negative having these extension lugs is shown in Figure 303. [Fig. 301 Cover of Prest-O-Light farm lighting cell] [Fig. 302 Parts of Prest-O-Light farm lighting cell: nut, stud, terminal, hard rubber bushing] [Fig. 303a Parts of Prest-O-Light farming light cell: glass jar, rubber jar, rubber cell connector, glass cell connector] [Fig. 303b Parts of Prest-O-Light farm lighting cell: positive plate and outside negative plate] [Fig. 303c Parts of Prest-O-Light farm lighting cell: long lead jumper, jumper, separator, short lead jumper] Specific Gravity of Electrolyte. The values of the specific gravity of Prest-O-Lite farm lighting batteries are as follows: Battery fully charged reads 1.250 Battery three-fourths charged reads 1.230 Battery one-half charged reads 1.215 Battery one-fourth charged reads 1.200 Battery discharged completely reads 1.180 These readings are to be taken with the electrolyte at a temperature of 80° Fahrenheit. Readings taken at other temperatures should be converted to 80°. To convert readings at a lower temperature to the values they would have at 80°, subtract one point for every two and one-half degrees temperature difference. For example, suppose a cell reads 1.225 gravity at 60°. To find what the gravity would be if the temperature of the electrolyte were 80° divide the difference between 80° and 60° by 2-1/2, or 80° minus 60° divided by 21/2 equals 8. The gravity at 80° would therefore be 1.225 minus .008, or 1.217, which is the value of specific gravity to use. If the specific gravity is read at a higher temperature than 80°, divide the difference between 80° and the temperature at which the gravity reading was taken by 21/2, and add the result to the actual gravity reading obtained. If, for example, the gravity were 1.225 at 100°, the gravity at 80° would be 1.225 plus .008, or 1.233. Charging Rates. The normal charging rate to be used in giving Prest-O-Lite batteries a regular charge or overcharge are as follows: Battery Charging Rate ------- ------------- 5 F.P.L. 5.0 amps. 7 F.P.L. 7.5 amps. 9 F.P.L. 10.0 amps. 11 F.P.L. 12.5 amps. 13 F.P.L. 15.0 amps. 15 F.P.L. 17.5 amps. Rebuilding Prest-O-Lite Farm Lighting Batteries Opening the Cell. 1. Make sure that the cell is as fully charged as possible. Since it is not very convenient to charge a single cell, a good time to open a cell for cleaning and repairing is immediately after the battery has been given an overcharge. See page 455. 2. Disconnect the cell from the adjoining ones. 3. Heat a thin bladed putty knife and insert it under the edge of the lead-antimony cover to melt the sealing compound. Run the knife all round the cover, heating it again if it should become too cool to cut the compound readily. 4. Grasp the lead posts above the cover and lift up gradually. This will bring up the cover, plates, and separators. 5. Place the plates on a clean board for examination. Use the instructions given on pages 339 to 346. Do not keep the plates out of the electrolyte long enough to let them dry, and the negatives heat up. If you cannot examine the plates as soon as you have removed them immerse them in 1.250 acid contained in a lead or non-metallic vessel until you can examine them. 6. In renewing the electrolyte, pour in as much new 1.250 acid as there was old electrolyte in the jar. (It is assumed that the electrolyte was up to the lower ridge of the glass jar before the cell was opened.) The new electrolyte must not have a temperature above 100 degrees when it is poured into the jar. 7. The separators can be pulled out easily when the plates are laid on their sides. All that is necessary is to remove the small rubber bridge at the bottom corners of the plates. The separators can then be pulled out. If the old separators are to be used again brush off any material that may be adhering to them, and keep them wet with 1.250 acid until they are replaced between the plates. Any separators that show cracks or holes, or that split while being replaced between the plates should be thrown away and new ones used. 8. It is not necessary to remove the sediment from the bottom of the jar unless it is within one half inch of the bottom of the plates. If the sediment is to be removed, carefully pour off the clear electrolyte into a lead, hard rubber, or earthenware jar, if the electrolyte is to be used again. 9. If one or two of the plates in either positive or negative groups need to be replaced it is best to burn a new plate to the strap without removing the peened cover. This is done by blocking under the row of plate lugs with metal blocks after cutting off old plate and cleaning the surface of strap. Insert new plate, the lug of which has been cut about 1/4 inch short, to allow for new metal. Choosing small oblong iron blocks of suitable size, build a form about the plate lug which fits same well. Now with a torch and burning lead fuse the new plate onto the old strap. When cool remove and test joint by pulling and slightly twisting the plate at the same time. Sometimes one group of a starting and lighting battery may be in sufficiently good condition to pay to combine it with a new group, but this condition will very rarely, if ever, be met in farm lighting cell service. We advise the replacement of the complete cell element if either group is worn out, for the cost of repairs and of new group will probably not be warranted by the short additional life which the remaining old group will give. 10. Putting Repaired Cell Back into Service. After having finished all necessary cleaning, replacement, or repairs, remove all old sealing material, return the element with attached lead cover to the cell jar. It is not necessary to reseal the cover to the jars this sealing is essential only for insurance against breakage or leakage in shipment. Add through the vent plug opening sufficient cool acid of 1.250 Sp. Gr. to reestablish the proper electrolyte level, which means that the electrolyte is brought up to the lower moulded glass ridge near the top of jar. Connect the cell with any other repaired cells and charge at normal rate already indicated under "charging rates" until dell voltage reads 2.5 or above, at 80°. The positive to cadmium voltage should be at least 0.10 volts less than cell voltage itself. When this condition is obtained cell may be replaced in operating circuit with others and should give satisfactory service. EXIDE FARM LIGHTING BATTERIES. Exide Farm lighting Batteries are made with sealed glass jars, open glass jars, and sealed rubber jars, each of which will be described. Batteries with Sealed Glass Jars. Two types with sealed glass jars are made, these being the Delco Light Type, and the Exide type. 1. Delco-Light Type. This type is shown in Fig. 294. The cell shown is a pilot cell, there being two of these in each battery as explained below. These cells are made in two sizes, the KXG-7, 7 plate, 80 ampere hour cell, and the KXG-13, a 13 plate, 160 ampere hour cell. These cells are assembled into a 32 volt, 16 cell battery, or a 110 volt, 56 cell battery. The plate groups are supported from the cover, the weight being carried by the wooden cover supports as shown in Fig. 294. The strap posts are threaded, and are clamped to the cover and supports by means of alloy nuts, just as is the case in Exide automobile batteries. A hard rubber supporting rod or lock pin extending across the bottoms of the plates holds the separators in position and prevents the plates from flaring out at the bottom. A soft rubber bumper fastened on each end of the rod acts as a cushion to prevent jar breakage in shipping. The hard rubber cover overlaps the flanged top of the jar, to which it is sealed with special compound. Battery Gauges and Instruments for Testing. Every set of Delco-Light batteries has either one or two cells equipped with a pilot ball. Such a cell is known as a PILOT CELL. Fig. 294. Pilot Cells are used to indicate to the USER the approximate state of charge or discharge of the battery. The pilot ball is a battery gauge which is UP or DOWN, depending upon the state of charge of the battery. Very high temperature affects the operation of the pilot ball. This accounts for-the fact that occasionally a battery will be charged and the pilot ball will be at the bottom of the pocket. A few hours later, after the electrolyte has cooled, the pilot ball will rise to the top. We urge that the user be made to feel that the pilot ball is an excellent gauge and a good signal to watch in connection with the care and operation of his Delco-Light plant and battery. (Further mention will be made of the pilot ball in connection with the subject of proper operation.) It is necessary that the maximum specific gravity of pilot cells be as near 1.220 as possible. Any great variation higher or lower will affect the operation of the pilot balls. Therefore, every effort should be made to adjust the maximum specific gravity of pilot cells to 1.220 when placed in service. Batteries equipped with one pilot cell contain a white pilot ball which will be up when the specific gravity of the electrolyte is approximately 1.185. This ball will drop DOWN when the specific gravity falls a little below 1.185. In other words, the pilot ball will float at a specific gravity of 1:185 or higher, and will sink at a specific gravity lower than 1.185. Therefore, when the pilot ball is UP, the battery is more than half charged. When the pilot ball is DOWN, the battery is more than half discharged. Batteries equipped with two pilot cells have one cell which contains a white ball and the other cell a white ball with a blue band. The plain white ball will be UP when the specific gravity is approximately 1.175. The blue band ball will be UP when the specific gravity is approximately 1.205. When both balls are UP, the battery is charged. When DOWN, the battery is discharged. The blue band ball will drop soon after the battery starts on discharge, or, in other words, when the specific gravity falls below 1.205. The white ball will remain UP until the specific gravity falls below 1.175. The Ampere-Hour Meter The ampere-hour meter, Fig. 304, is an instrument for indicating to the user the state of charge of the battery at all times and serves to-stop the plant automatically so equipped, when the battery is charged. (Further mention will be made of the ampere hour meter on page 471.) In order to check the speed of the ampere-hour meter, use the following rule: On charge, the armature disc should give 16 revolutions in 30 seconds, with a charging rate of 15 amperes; on discharge, the armature disc should give 20 revolutions in 30 seconds, with a discharging rate of 15 amperes. [Fig. 304 Delco-Light Ampere-Hour Meter] Hydrometers The standard hydrometer for service men is known as the Type V-2B. A special type hydrometer showing three colored bands in place of numbers has been designed for users. The bands are red, green and black. When the hydrometer test shows the bottom of the red band in the electrolyte, the battery, whether in glass or rubber jar, is discharged. When the top of the green band is out of the electrolyte, the glass jar battery is charged. The top of the black band out of the electrolyte indicates the rubber jar battery is charged. When and How to Charge Battery Plants with Average Loads Loads of legs than ten (10) amperes can be taken directly from the battery, until: 1. The large hand on the ampere-hour meter reaches 12, or 2. Both pilot balls are down, or 3. Hydrometer test shows bottom of red band in the electrolyte. If any or all of the three gauges listed above show the battery discharged, the plant should be started and operated continuously until the battery is charged, as indicated by: 1. Ampere-hour meter hand at FULL, or 2. Both pilot balls UP, or 3. Hydrometer test shows top of FULL band out of electrolyte. (NOTE: Any one or all of the above three items may indicate battery charged. Meter hand at FULL would necessitate both balls UP. If both balls are not up, set hand back and charge to bring them up; then set hand at FULL.) Should the user be operating for two or three hours with a seven or eight-ampere load, it would be more efficient to run the plant to carry this load. This only applies for those cases where the battery is partly discharged. Carry Heavy Loads Greater Than 10 Amperes. If there is a constant load of 10 amperes or more, the plant should be started up when the heavy load comes on. When the heavy load is off, the plant may be stopped, but it would be entirely satisfactory to allow the plant to continue to run until "Charged," as indicated by: 1. Ampere-hour meter hand reaches FULL, or 2. Both pilot balls are UP, or 3. Hydrometer test shows top of FULL band out of electrolyte. In any case, plant should be run until battery is "Charged" at least once a week. Always Start Charging When Battery Gauges Indicate Battery Discharged. On ampere-hour meter plants, when the hand is at FULL, the plant cannot be operated on account of the ignition circuit being broken. In such cases allow load to be taken from the battery until the hand travels back sufficiently to allow the plant to run. Occasionally the plant and battery are used to carry continuous loads of from 10 to 15 amperes each night, with practically no day load. This condition necessitates running the plant to carry the load, but at the same time the battery is continually receiving from 10 to 15 amperes charge, with the result that the battery may receive too much charging. This would be indicated by the battery bubbling freely every time the plant is operated. To prevent this condition, the user should be instructed to carry the load off the battery frequently enough to prevent continual bubbling. Where Small Load Is Used. There are many installations where the battery capacity is sufficient to last several weeks. On installations of this kind it is advisable to charge the battery to FULL at least once a week. The dealer or service man should use his own judgment on the preceding instructions as to which is best suited for the different conditions encountered. Regularly on the first of each month, regardless of whether or not the battery has been used, a special charge, called the Equalizing Charge, should be given. This charge should be given as follows: The battery should be charged until EACH cell is bubbling freely from top to bottom on surface of the outside negative plates and then the charge should be continued for TWO MORE HOURS. The monthly equalizing charge is a NECESSARY precautionary measure to insure that the user will bring each cell in the battery up to maximum gravity at least once a month. It also provides a means on the ampere-hour meter plants to set the ampere-hour meter hand at FULL when the battery is FULL. The users should be cautioned to inform the service man or dealer immediately if any cell fails to bubble at the end of an equalizing charge, when all others are bubbling freely. This will enable the service man to inspect such cells for trouble and remedy same before the trouble becomes serious. (See further information under inspection and repairs.) INSPECTION TRIPS Undercharging or injurious sulphation is the most common trouble encountered. Undercharging causes the plates to blister and bulge, and in place of good gray edges on the negative plates and good brown color edges on the positive plates, the edges will show a faded color, with very little brown color showing on the edges of the positive plates. Overcharging is not so evident on inspection, except that in such cases the active material from the positive plates, which is brown in color, will be thrown to the bottom as sediment more rapidly than the sediment would accumulate due to normal wear. Heavy usage on a battery will also cause considerable sediment in the bottom of the cells, so that it is necessary to investigate carefully whether it is overcharging or overwork. A few questions as to method of operation and load requirements will aid in deciding the cause of excessive sediment. (See When and How to Charge, page 468.) Sediment Space Filled. When the space below the plates is filled up with sediment and touching the plates, the cell becomes short-circuited and will deteriorate very rapidly. It will be noticed, however, that the sediment is heaped in the middle of the cell. If the cells are unbolted and unshaken, it will level the sediment and leave a space between the sediment and plates. It is very important that the sediment be shaken down before the cell becomes short-circuited. This will very often prolong the life of the battery a number of months. When the sediment space is completely filled, approximately all the active material will be out of the positive plates. A thorough study should be made as to the general condition of the battery and method of operation before forming an opinion or suggesting any change in method of operation. Check Ampere-Hour Meters On plants which have ampere-hour meters, the meter should be checked as to its speed on discharge, and also check position of the meter hand at the time of inspection, to see if it checks with the specific gravity and the pilot balls. (See Ampere Hour Meter, page 467.) It will generally be found that when a battery is sulphated, it is operating in very low specific gravity, or, in other words, the charges have not been carried far enough to drive all the acid out of the plates. A battery that is not receiving quite enough charge may not as a whole become "sulphated," but several cells might become considerably weaker than the others and become "sulphated," causing trouble in these particular cells. Such cells will not bubble freely, or possibly not at all, when the other cells are bubbling freely. Therefore, a few questions to the user will generally help in locating the low cells. Cells that are in trouble, or which soon will be, can very easily be picked out by making a few tests on the battery. Therefore, on all inspections, regardless of the age of a battery, it is suggested that the following tests be made: Take a specific gravity reading of all cells and note if there are any cells much lower than the others. Amy cells having a specific gravity of 30 points lower than the average will generally be found to be in trouble, unless these cells happen to be low from having had spillage in shipment, replaced with water. (This condition, however, should not exist in future installations if the spillage is properly taken care of, as has been explained on page 482.) Voltage Readings After taking a specific gravity reading, a voltage reading of each cell should be taken. Voltage readings taken on open circuit are of no value, so while taking these readings the battery should be on discharge, having at least a discharge of 15 amperes. A good way to get this discharge is to hold the starting switch in and set mixing valve lever at lean point or wide open. A low or defective cell will show a voltage reading .10 to .20 volts lower than the other cells on discharge, while a reversed cell will show a reading in the reversed direction when on discharge, especially on heavy discharge. The voltage readings are a sure check if taken in connection with the specific gravity. When you have low specific gravity and low voltage on the same cells, it is a sure indication of low cells. These cells should be inspected for the probable cause of their being low. Shorting of the lugs at bottom of plates and moss bridging across at bottom of the elements, or possibly a split separator, will generally be the main trouble. When any of these conditions exist, it is best to take the low cells back to your shop for repairs. When there is absolutely no indication why the cells are low, they can be cut out of the battery on discharge and put in on charge, until they come up. The following is a good example of readings taken on a battery with a 10-ampere discharge and having four low cells, 4, 8, 11 and 16. The battery had been giving poor service, due to insufficient charging: Cell No. Specific Gravity Volts 1 1.200 1.98 2 1.180 1.95 3 1.205 1.98 4 1.150 1.75 5 1.190 1.95 6 1.195 1.98 7 1.200 1.98 8 1.130 1.70 9 1.200 1.95 10 1.205 1.98 11 1.100 1.40 12 1.190 1.95 13 1.180 1.95 14 1.195 1.98 15 1.190 1.95 16 0.000 zero or reversal The main thing to consider in checking voltage readings is the variation from the average. The average voltage readings will vary, depending on the state of charge of the battery when the readings are taken. REPAIRS To repair, the following equipment is necessary: 1. Portable lead burning outfit. 2. A suitable blow torch. 3. Standard sealing nut wrench. 4. File (shoemaker's rasp). 5. Pair of pliers. 6. Putty knife. 7. Pair of tin snips. 8. Wooden blocks to support elements while being worked upon. 9. Good supply of battery parts consisting of: KXG-13 Glass jars KXG-13 Pilot jars KXG-13 Positive groups KXG-13 Negative groups KXG-13 Round rods KXG-13 Vent plugs Sealing nuts Rubber gaskets Wood separators KXG-13 Rubber covers KXG-7 Round rods Lead pins Carboy electrolyte (including retainer). KXG-7 Pilot jars KXG-7 Glass jars KXG-7 Positive groups KXG-7 Negative groups Outside negative plates KXG-7 Rubber covers Emergency repair straps Disassembling a Cell The glass jar battery covers are sealed to the jars by sealing compound, which may be softened very easily with a blow-torch. When a blow-torch or an open flame is used for softening the sealing compound, the vent plug MUST be removed before applying a flame. It is also important to blow into the vent after the plug has been removed in order to expel any gas that may have collected in the space above the electrolyte in the cell. If the gas is held in place by leaving the vent plug in, it is apt to explode when an open flame or intense heat is applied to the cover., Removing covers may be greatly facilitated by suspending the cell by the terminals, as shown in Fig. 305. Care should be taken to make this suspension so that the bottom of the jar will not be more than two inches above the table. A pad of excelsior should be placed under it to avoid breaking the glass jar when it drops. [Fig. 305 Softening sealing compound, Delco-Light cell] After the sealing compound has been sufficiently softened, the cover may be loosened by inserting a hot putty knife, as shown in Fig. 306, There is no danger of breaking the cover by this operation if the cover has been sufficiently warmed. After the jar of electrolyte has dropped, the element should be removed from the jar and carefully placed across the top of it, so that the solution upon the plates will drain back into the jar. (See Fig. 307.) [Fig. 306 Removing Delco-Light cell cover] [Fig. 307 Draining element, Delco-Light cell] [Fig. 308 Removing cover of Delco-Light cell] [Fig. 309 Removing lock pin, Delco-Light cell] After element has drained, place on wooden blocks, as shown in Fig. 308, and remove cover. Clean the sealing compound from the cover and jar immediately with a putty knife. Turn element upside down with posts through holes in bench and remove lead pin and rubber bumper and withdraw, lock pin. (Fig. 309.) The separators may then be withdrawn from the group. (Fig. 310.) [Fig. 310 Removing separatots, Delco-Light cell] [Fig. 311 Assembling separators, Delco-Light cell] Assembling Place the positive and negative groups upside down with posts through holes in bench and slide in separators. The wood and rubber separators are inserted as follows: The rubber separator is placed against the grooved side of the wood separator, and the two are then slipped between the negative and positive plates with the rubber separator next to the positive plate. (See Fig. 311.) Inserting Locking Pin A rubber bumper is pinned on one end of the lock pin by means of a lead pin, and the lock pin is then slipped into place with the lock pin insulating washer placed between the outside negative plates and the wood separators. (See Fig. 312.) A rubber bumper is then slipped over the other end of the lock pin and secured by a lead pin. Place element on wooden blocks and fasten cover, as shown in Fig. 313. [Fig. 313 Fastening cover, Delco-Light cell] [Fig. 314 Preparing cover for sealing, Delco-Light cell] Sealing Covers Be sure all old sealing compound and traces of electrolyte are removed from the cover. Heat sealing compound until it can be handled like putty, roll out into a strip about 1/2 inch in diameter, place strip of compound around inside edge of cover (Fig. 314) and heat to melting point with blow-torch. The top of jar should also be heated to insure a tight seal. Compound can be melted in a suitable vessel and a 1/2 inch strip poured around cover. When sealing compound and jar have been heated sufficiently, turn jar upside down (Fig. 315) and carefully place jar over element and press gently into compound. (Do not press hard.) Immediately place jar and element upright, and press cover firmly into place. (Press hard.) Finally, tighten sealing nuts. The cell is now ready for the electrolyte. [Fig. 315 Sealing jar of Delco-Light cell] Filling Cell with Electrolyte Repaired cells should be filled with electrolyte of 1.200 specific gravity, or with water, as the case may require. Standard Delco-Light electrolyte of 1.220 specific gravity may be purchased from the Delco Light distributor. The 1.220 electrolyte should be reduced to 1.200 by adding a very small amount of distilled water. This should be thoroughly mixed by pouring the solution from one battery jar into another. The 1.200 specific gravity electrolyte may then be added to the newly assembled cell until flush with the water line. Charging The completed KXG-13 cell should be placed on a 12-ampere charge and kept on charge until maximum gravity has been reached. A KXG-7 cell should be charged at a 6-ampere rate. Adjusting Gravity of Electrolyte If the maximum gravity is above 1.220, draw off some of the electrolyte and refill to water line with distilled water. The charge should then be continued for at least one hour to thoroughly mix the electrolyte before taking another hydrometer reading. It may be necessary to repeat this operation. If the maximum gravity is below 1.220, pour off the electrolyte into a glass jar or a suitable receptacle, and then refill the cell with 1.220 electrolyte. Charge for one hour to thoroughly mix the solution before checking readings. NOTE: Gravity readings in adjusting the electrolyte should always be taken in connection with thermometer readings, making necessary temperature corrections. This is particularly important in adjusting electrolyte in pilot cells. HOW TO REPAIR DELCO-LIGHT CELLS Treating Broken Cells Whenever a shipment of batteries is received in which any of the jars have been broken, the first thing to do is to carefully remove the elements from the broken jars to prevent damage to the plates or separators. These elements should be placed in distilled water to prevent further drying. The plates will not be damaged in any way and can be restored to a healthy condition by charging in 1.200 specific gravity at a 12-ampere rate for the 13-plate cell or, 6-ampere rate for the 7-plate cell, until maximum gravity is reached. (See Charging and Adjustment of Electrolyte, explained on page 481.) Treating Spilled Cells If the spillage is more than one inch below the water level, it should be replaced by electrolyte of 1.200 specific gravity and charged to maximum gravity. Treating Badly Sulphated Cells That Have Been in Service When cells are removed from an installation to make repairs, they are usually badly sulphated, which means that considerable acid is in the plates. In charging such cells, use distilled water in place of electrolyte, as this will allow the acid to come out of the plates more readily. The KXG-13 cells should be charged at about 12 amperes and the KXG-7 cells at 6 amperes. Cells badly sulphated when charged at the low rate will require from 50 to 100 hours to reach maximum gravity. Extreme cases will require even longer charging. In case it is impossible to read the gravity after the cells have been on charge a sufficient length of time, pour out the solution and use 1.220 specific gravity. The charge should then be continued further to insure that maximum gravity has been reached. CAUTION: Should the temperature of the electrolyte approach 110° F., the charging rate should be reduced or the charge stopped until the cell has cooled. Treating Reversed Cells A complete battery may be reversed if the battery is completely discharged and its voltage is not sufficient to overcome any residual magnetism the generator might have. Under such conditions the negative plates will begin to discolor brown and the positive turn gray. Such a case would be extremely rare. The remedy is to first completely discharge the cells to get rid of the charge in the wrong direction. Then short-circuit them. (Connect a wire across the terminals.) Then charge them in the right direction at a low rate. (12 amperes for a KXG-13 cell, or 6 amperes for a KXG-7 cell.) Charge until the specific gravity reaches a maximum. If the battery is operated reversed for any length of time, the negatives will throw off their active material and become useless. A single cell may become reversed by gradually slipping behind the rest of the cells in a set, due to insufficient charging, until it becomes so low that it will reverse on each discharge. This condition cannot be corrected by giving the regular charge, but it will be necessary to give an equalizing charge, continuing the charge until the cell is in normal condition. (Be sure to make temperature corrections when taking hydrometer readings.) If the cell appears to require an excessive amount of charge to restore it to condition, it should be removed and taken to the repair shop for a separate charge. If the cell has been allowed to operate in a reversed condition to such an extent that the entire material of the negative plates has turned brown, both positive and negative groups should be discarded. Removing Impurities Impurities, such as iron, salt (chlorine) or oil, may accidentally get into a cell, due to careless handling of distilled water. Iron is dissolved by sulphuric acid and the positive plates become affected, change color (dirty yellow) and wear rapidly. The cell becomes different from the rest in gravity, voltage and bubbling. The remedy is to discard the electrolyte as soon as possible, flush the plates and separators in several changes of water, thoroughly wash the jar, use new electrolyte and then proceed in same manner as explained for the treatment of badly sulphated cells, page 482. Chlorine has an effect about as described for iron, and is evident by the odor of chlorine gas. The remedy is the same as for iron. Oil in the electrolyte, if allowed to get into the pores of the plates, will fill them and lower the capacity very much. It affects negative plates much more than positives. Probably the only remedy in this case is new plates. Impurities of any nature should be removed as quickly as possible. Clearing High Resistance Short Circuits A high resistance short is caused by the sediment falling from the plates and lodging between the positive and negative lugs. As a rule this condition will occur only when severe sulphation is present in the plates. A cell in this condition can be repaired by removing the element and clearing the short circuit. The wood separators should then be withdrawn and replaced by new ones. Lock pin insulating washers. should be installed land the element reassembled in the jar and charged to maximum gravity. Clearing Lug Shorts Short-circuited lugs are caused by excessive sulphation. The outside negative bulges and the bottom lug bends over and touches the adjacent positive lug. This can be remedied by removing both outside negative plates and burning on new plates which have already been charged and inserting lock pin insulating washers. Putting Repaired Cells Back in Service When placing a new or repaired cell in a battery which is in service, connect in the cell at the beginning of a charge. This will insure that the new or repaired cell is started off in good condition, because this charge is of the nature of an initial charge to these cells. Charging Outside Negative Plates Individual negative plates are always received dry, which makes it necessary to charge them before using. The best way to charge such plates is as follows: Set up 7 loose negative plates in a KXG-13 jar together with a good positive group, using KXG separators to prevent the plates touching. Then stretch a piece of wire solder across the lugs at the top of the negative plates and solder the wire to the plates. Fig. 316. The jar may then be filled with 1200 specific gravity and the plates charged at a 12-ampere rate until maximum gravity is obtained. Never use negative plates unless they have been treated as described above. After the charge is completed, the negative plates may be placed in distilled water and kept until ready for use. Always be sure to give a charge to maximum gravity after burning on new negative plates to an element. [Fig. 316 Preparing outside negatives for charging] Pressing Negative Plates After badly sulphated cells are recharged, it is sometimes advisable to remove the elements and, press the negative plates, as explained on page 351. Care should be taken to prevent the negative plates from drying out while making repairs, in order to avoid the long charge necessary for dried negative plates. The battery should be charged to maximum gravity before attempting to press the plates. It is not necessary and will do no good to press the positive plates. In some cases the active material may be nearly all out of the outside negative plates and the inside negatives may be in good condition, in which case new charged plates should be burned on. (Fig. 322.) Salvaging Replaced Cells When it has been necessary to replace cells which have been in service, the elements can very often be saved and assembled again and used as replacement cells in batteries which are several years old. In no case should the cells be used as new cells. The positive plates may be allowed to dry out, but the negatives should be kept in distilled water and not allowed to dry out in the least. They should not be kept this way indefinitely, but should be assembled and charged as soon as possible. Do not attempt to repair groups or plates which have lost as much as half of the active material in wear, or which have the active material disintegrated and falling out. Such plates should not be used. This does not apply to small bits of active material knocked out mechanically and amounting to an extremely small percentage of the whole. Abnormal color indicates possible impurity, and such plates should be washed and used with caution. Badly cracked or broken plates should be replaced with new plates or plates from other groups. Before new negative plates are used they should be fully charged. (See Charging Negative Plates, page 484.) Always use new wood separators when assembling repaired cells. When cells have been operated reversed in polarity to such an extent that the active material of the negative plates has turned brown, both positive and negative groups may have to be replaced. Repairing Lead Parts The portable carbon burning outfit used for battery repairs is operated from the battery itself, making it possible to make repairs at the user's residence without using a gas flame. This outfit can be secured from the Delco-Light Company, Dayton, Ohio, and consists of a carbon holder with cable, clamp, and one-fourth inch carbon rods. Six cells are usually required to properly heat the carbon. If it is completely discharged an outside source must be used. For this purpose a six-volt automobile battery is suitable, or a tray of demonstrating batteries, one terminal being connected to the connection to be burned, the other to the cable of the burning tool. A little experience will soon demonstrate the number of cells necessary to give a satisfactory heat. The cable is connected by means of the clamp to a cell in the battery, the required number of cells away from the joint to be burned. Care should be taken that contact is made by the clamp, the lead being scraped clean before the connection is made. The carbon should be sharpened to a long point like a lead pencil and should project not more than 2 inches from the holder. (Fig. 317.) [Fig. 317 Repairing broken post, Delco-Light cell] After being used a short time, the carbon will not heat properly, due to a film of scale formed on the surface. This should be cleaned off with a file. In case of lead burning, additional lead to make a flush joint should not be added until the metal of the pieces to be joined has melted. The carbon should be moved around to insure a solid joint at all points. In case a post is broken off under the cover, proceed as follows: To make repairs take an old group and cut off the post about one-half way down. Saw off the post to be repaired to such a length that when the new post is burned on the length of the post will be approximately the same length as the original post. Repairing Broken Posts. Make a half circle mould out of a piece of tin or galvanized iron, as shown in Fig. 317. Burn solid the side of the post facing up, file it around and then turn the group over, place the form on the burned side and proceed to complete the burning operation. Caution: 1. Always use clean lead. 2. Do not clean the lead and let it stand for any length of time before starting to burn. If it is allowed to stand it will oxidize and prevent a good burning operation. 3. Burn with an are and not with a red hot carbon. Burning on Straps Place the strap to be burned in a vise and split the end through the center and then bend the two halves over to form a foot, as shown in Fig. 318. Make a mould out of a piece of tin or galvanized iron and place this mould around the post to which this strap is to be burned. (Fig. 319.) Then proceed to burn the post and strap together. [Fig. 318 Splitting end of strap, Delco-Light cell] When a union is made between the strap and the post a small amount of new clean lead should be burned on the top of the foot to reinforce this point. Care should be taken not to get the mould too high, as this will cause trouble in getting the carbon down to the foot and the post. [Fig. 319 Burning on negative strap, Delco-Light cell] [Fig. 320 Auxiliary strap, Delco-Light cell] [Fig. 321 Positioning auxiliary strap, Delco-Light cell] How to Eliminate Burning on Straps by Use of an Auxiliary Strap A very good way to repair broken straps without the burning operation is to use the auxiliary strap shown in Fig. 320. This strap is slipped over the post of the terminal or strap which is broken and the sealing nut is then clamped down on the strap, as shown in Fig. 321. These straps may be obtained from the Delco-Light Distributors or from the Delco-Light factory at Dayton, Ohio. Burning on New Plates [Fig. 322 Burning on outside negative plate, Delco-Light cell] When it is necessary to burn on new plates, carefully clean with a file the lead on both the plate and the common strap to which all plates of the group are attached. Block up the plate with thin boards or wood separators until it is spaced the proper distance from the adjacent plate. Care should be taken to see that the side and bottom edge of the plate to be burned on is in line with the other plates of the group. Proceed to burn on the plate by drawing a small blaze or are and do not attempt to burn with just a glowing carbon. (Fig. 322.) If only a glowing carbon is used the result will be a smeary mass and in the majority of cases will not hold, due to the fact that it is not welded but simply attached in one or two points. The principle of lead burning is to weld or burn two parts into one solid mass and not merely attach one to the other. Keeping Wood Separators In Stock No wood separators should be used except those furnished by the Delco-Light Company. These should be kept in distilled water, to which has been added 1.220 electrolyte in the proportion of one part to ten parts of water. It is advisable whenever possible to use new separators when making repairs on a cell. Separators which have been in service are liable to be damaged by handling. Freezing Temperature of Electrolyte The freezing temperatures of electrolyte in the Delco-Light batteries depends upon the specific gravity of the battery. The Delco-Light battery fully charged, with a specific gravity of 1.220, should not freeze above a temperature of 30 degrees below zero. Since, however, the freezing point rises very rapidly with a decrease in specific gravity, special care should be taken to keep batteries charged when temperatures below zero are encountered. The following table shows freezing temperatures of several different gravities of electrolyte. Specific Gravity Freezing Point ---------------- -------------- 1.100 19° F. above zero. 1.150 5° F. above zero. 1.175 6° F. below zero. 1.200 16° F. below zero. 1.220 31° F. below zero. At the temperature given, the electrolyte does not freeze solid, but forms a slushy mass of crystals, which does not always result in jar breakage. Care of Cells in Stock Frequently a Dealer or Distributor will have several sets of new batteries in stock for five or six months. In this case, the cells should be given a freshening charge before putting into service. This charge should consist of charging the cells to maximum gravity. Cells received broken in transit or cells sent in for repairs should be repaired and charged as soon as possible and put into service immediately. This eliminates the possibility of the cells standing idle over a long period in which they would need a freshening charge before they could be used. However, if such cells must be kept in stock, they can be maintained in a healthy condition by keeping on charge at a one fifth ampere rate for 13-plate cells and one-tenth ampere rate for 7-plate cells. Taking Batteries Out of Commission If a battery is not to be used at all for a period not longer than about 9 months, it can be left idle if it is first treated as follows: Add sufficient water to bring the electrolyte up to the water line in all cells and then give an equalizing charge, continuing the charge until the specific gravity of each cell is at a maximum, five consecutive hourly readings showing no rise in gravity. As soon as this charge is completed, take out the battery fuse and open up one or two of the connections between cells so that no current can be taken from the battery. Have vent plugs in place to minimize evaporation. If the battery is to be taken out of commission for a longer time than 9 months, the battery should be fully charged as above and the electrolyte poured off into suitable glass or porcelain receptacles. The plates should immediately be covered with water for a few hours to prevent the negatives heating, after which the separators should be removed, the water poured out of the jars, and the positive and negative groups placed back in the jar for storage. Examine the separators. If they are cracked or split they should be thrown away. If in good condition they should be stored for further use in a non-metallic receptacle and covered with water, to which has been added electrolyte of 1.220 specific gravity, in the proportion of one part electrolyte to ten of water by volume. Putting Batteries Into Commission After Being Out of Service When putting batteries into commission again, if the electrolyte has not been withdrawn, all that is necessary is to add water to the cells if needed, replace connections, and give an equalizing charge. If the electrolyte has been withdrawn and battery disassembled, it should be reassembled, taking care not to use cracked, split or dried-out separators, and then the cells should be filled with the old electrolyte, which has been saved, provided no impurity has entered the electrolyte. After filling, allow the battery to stand for 12 hours and then charge, using 6 amperes for KXG-7 size and 12 amperes for the KXG-13 size. Charge at this rate until all cells start gassing freely or temperature rises to 110° F. Then reduce the charging rate one-half, and continue at this rate until the specific gravity is at a maximum, five consecutive hourly readings showing no rise in gravity. At least 40 hours will be required for this charge. To obtain these low rates with the Delco-Light plant, lights or other current-consuming devices must be turned on while charging. General Complaints from Users and How to Handle Them. 1. Pilot balls do not come up. This condition may be caused by (a) Battery discharged. (b) Weak electrolyte caused by spillage in shipment. (c) Defective ball. Question the user to determine whether the ball will not come up if the pilot cell is bubbling freely. Weak electrolyte or a defective ball will require a service trip to determine the one which is responsible for the ball not rising. (See page 470.) 2. Lights dim-must charge daily. This condition may be caused by (a) Discharged battery. (b) Loose dirty connections in battery or line. (c) Low cells in battery. The user should be questioned to determine whether the battery is being charged sufficiently. In case the user is positive the battery is charged, the next probable trouble would be that there were some loose or dirty connections in either plant or battery. Have the user check for loose connections. Should it be necessary to make an inspection trip, instruct the user to give battery an equalizing charge so the battery will be fully charged when the inspection is made. Low cells can be checked by asking the user if all of the cells bubble freely when equalizing charge is given. In case user claims several cells fail to bubble, an inspection trip would be necessary to determine the trouble. (See page 470.) 3. Cells bubbling when on discharge. This complaint would indicate a reversed cell. (See page 483.) 4. Cells overflowing on charge. This would mean that the cells were filled too high above water lines. 5. Engine cranks slowly but does not fire. This would indicate over-discharged battery. Explain to user how to start plant under this condition. 6. Plant will not crank. This might be caused by (a) Blown battery fuse. (b) Battery over-discharged. (c) Loose or broken connection on battery or switchboard. OTHER EXIDE FARM LIGHTING BATTERIES The Exide type is shown in Figure 296. The plates are held in position both by the cover and by soft rubber support pieces in the bottom of the jar. The support pieces are provided with holes in which projections on the bottom of the plates are inserted. The cover is of heavy moulded glass. The separators are of grooved wood in combination with a slotted rubber sheet (Fig. 297). The strap posts are threaded and are clamped to the cover by means of alloy nuts. The cover overlaps the top of the jar to which it is sealed with sealing compound. The method of sealing and unsealing is practically the same as in the Exide Delco-Light Type. Batteries with Open Glass Jars Batteries with open glass jars, in addition to the conducting lug, have two hanging lugs for each plate. The plates are hung from the jar walls by these hanging lugs, as shown in Figs. 323 and 324. The plate straps, instead of being horizontal are vertical and provided with a tail so that adjacent cells may be bolted together by bolt connectors through the end of the tail. 1. The Exide Cell is shown in Fig. 324. It has a grooved wood separator between each positive and negative plate. The separators are kept from floating up by a glass "hold-down" laid across the top. The separators are provided at the top with a pin which rests on the adjoining plates. The pins together with the plate glass hold-downs keep the separators in Position. To remove an element it is simply necessary to unbolt the connectors, remove the glass cover and hold-down and lift wit the element. 2. The Chloride Accumulator cell is shown in Fig. 323. It differs from the Exide only in type of plates and separators. The positive plates are known as Manchester positives and have the active material in the form of corrugated buttons which are held in a thick grid, as shown in Fig. 325. The buttons are brown in color, the same as all positive active material. The separators, instead of being grooved wood, am each a sheet of wood with six dowels pinned to it. The element is removed the same as in the Exide type. [Fig. 323 Exide chloride accumulator cell with open glass jar, and Fig. 324 Exide cell with open glass jar] Batteries with Sealed Rubber Jars 1. The Exide cell is shown in Fig. 326. It is assembled similar to Exide starting and lighting batteries, except that the plates are considerably thicker, wood and rubber separators are used, and the terminal posts are shaped to provide for bolted instead of burned-on connection. The method of sealing and unsealing the cells is the same as in Exide starting and lighting batteries. All instructions already given for glass for cells apply to rubber jar cells except for a few differences in assembling and disassembling. Care should be taken to keep the water level at least 1/2 inch above plates at all times as the evaporation is very rapid in rubber jar cells. The temperature should be watched on charging to prevent overheating. Never allow temperature to go above 110° F. Unlike the glass jar cells the sediment space in the rubber jar is not sufficient to take care of all the active material in the positive plates. On repairs, therefore, always clean out the sediment and prevent premature short circuits. [Fig. 325 Manchester positive plates, and Fig. 326 Exide cell with sealed rubber jar] WESTINGHOUSE FARM LIGHTING BATTERIES Jars. Westinghouse Farm Lighting Battery jars are made of glass, with a 5/16 inch wall. The jars are pressed with the supporting ribs for the elements an integral part from a mass of molten glass. A heavy flange is pressed around the upper edge to strengthen the jar. Top Construction. A sealed-in cover is used similar to that used in starting and lighting batteries. The opening around the post hole is sealed with compound. Plates. Pasted plates are used. The positives are 1/4 inch thick, and the negatives 3/16 inch. Posts are 13/16 inch in diameter. Separators. A combination of wood and perforated rubber sheets is used. Opening and Setting-Up Westinghouse Farm Lighting Batteries [Fig. 327 Westinghouse farm lighting cell] It is preferable that the temperature never exceed 100 deg. Fahrenheit nor fall below 10 deg. in the place where the battery is set up. If the temperature is liable to drop below 10 degrees the battery should be kept in a fully charged condition. 1. Remove all excelsior and the other packing material from the top of the cells. Take cells out carefully and set on the floor. Do not drop or handle roughly. Be sure to remove the lead top connectors from each compartment. 2. Cells should be placed 1/4 inch apart. Also, cells should be placed alternately so that positive post of one cell is adjacent to negative post of the next cell. Positive post has "V" shape shoulder and the negative post has a square shoulder. 3. Grease all posts, straps and nuts with vaseline. 4. Connect positive posts of each cell to negative post of adjacent cell, using top connectors furnished. Top connectors are made so as to fit when connection is made between positive post of one cell and negative post of next cell. Use long connector between end cells of upper and lower shelves. 5. With all connections between cells in position, join the remaining positive post with a connection marked "Positive" leading from the electric generator. Do likewise with the remaining negative post. 6. If liquid level in any cell is 1 inch or more below the "Liquid Line" on side of glass jar, some liquid has been spilled and must be replaced. This should be done by an experienced person. 7. Immediately after installation operate electric generator and charge battery until gas bubbles rise freely through the liquid in all cells. A reading with the hydrometer syringe which is furnished with the battery should be taken, When the hydrometer float reads between 1.240 and 1.250, the battery is fully charged. 8. The time required to complete the charging operation mentioned above may vary from one to several hours, depending upon the length of time the battery has been in transit. During the charge the temperature of the cells should not be permitted to rise above 110 deg. Fahrenheit. If this condition occurs discontinue the charge or decrease the charge rate until cells have cooled off. 9. When charge is complete replace vent plugs. The Relation Between Various Sizes of Westinghouse Farm Light Batteries and Work to be Done The size of the battery furnished with complete farm lighting units vary greatly. Sometimes the battery size is varied with the size of the engine and generator, while again the same size of battery may be used for several sizes of engines and generators. In making replacements, while it is always necessary to retain the same number of cells, it is not necessary to retain the same size of cells. Usually increasing the cell size increases the convenience to the owner and prolongs the life of the battery to an amount which warrants the higher cost. With a larger battery, danger of injury through overcharging is lessened, the load on the battery is more easily carried and the engine and generator operate less frequently. In order to give an idea of various battery capacities, below is a table showing the number of 32 volt, 25-watt lamps which may be lighted for various lengths of time from sixteen cells. The number of hours shows the length of time that the lamps will operate. Table A Type 3 Hours 5 Hours 8 Hours ---- ------- ------- ------- G-7 22 Lamps 14 Lamps 10 Lamps G-9 28 Lamps 19 Lamps 13 Lamps G-11 32 Lamps 24 Lamps 15 Lamps G-13 41 Lamps 29 Lamps 19 Lamps G-15 47 Lamps 33 Lamps 22 Lamps G-17 54 Lamps 38 Lamps 25 Lamps Note:--Based on 32-Volt 25-Watt Lamps. For example--The table shows opposite G-7 that, with the battery fully charged, twenty-two lamps may be lighted for three hours, fourteen lamps for five hours and ten lamps for eight hours, by a sixteen cell G-7 battery, without operating the engine and generator. Motors for operating various household and farm appliances are usually rated either in horsepower or watts. The following table will give a comparison between horse-power and watts as well as the number of 25-watt lamps to which these different sizes of motors and appliances correspond. Table B H.P. of Motor No. of Watts Corresponding No. of 25-Watt Lamps ------------- ------------ -------------------- 1/8 93 4 1/4 185 7 1/2 373 15 3/4 559 22 1 H.P. 746 30 From table B it will be seen, for example, that a one horsepower motor draws from the battery 373 watts or the same power as do fifteen 25-watt lamps. Then referring to table A, it will be found that a G-11 battery could operate 15 lamps or this motor alone for 8 hours. Due to the fact that a motor or electric appliance may become overloaded and therefore actually use many more watts than the name plate indicates, it is not advisable to operate any motor of over 1/4 H. P. or even an appliance of over 186 watts on the G-13 or smaller sizes unless the engine and generator are running. It is safe, however, to operate motors or other appliances up to 375 watts on the G-15 or G-17 batteries without operating the engine and generator. WILLARD FARM LIGHTING BATTERIES [Fig. 328 Willard Farm Lighting Cell] The Willard Storage Battery Co. manufactures farm lighting batteries which use sealed glass jars, or sealed rubber jars. Those using the sealed glass jars include types PH and PA. The sealed rubber jar batteries include types EM, EEW, IPR, SMW, and SEW. Both types of batteries are shipped fully charged and filled with electrolyte, and also dry, without electrolyte. The following instructions cover the installation and preparation for service of these batteries. Glass Jar Batteries. Fully Charged and Filled With Electrolyte Each sixteen cell set of batteries is packed in two shipping crates. One crate, which is stenciled "No. 1" contains: * 8 Cells. * 18 Bolt Connectors. * 1 Hydrometer Syringe. * 1 Instruction Book. The other crate which is stenciled "No. 2" contains: 8 Cells (NOTE:--If the batteries are re-shipped by the manufacturer or distributor, care must be exercised to see that they are sent out in sets.) Unpacking Remove the boards from the tops of the shipping crates and the excelsior which is above the cells. To straighten the long top connector, grasp the strap firmly with the left hand close to the pillar post and raise the outer end of the strap until it is in an upright position. Do not make a short bend near the pillar post. Lift the cells from the case by grasping the glass jars. Do not attempt to lift them by means of the top connectors. Clean the outside of the cells by wiping with a damp cloth. Inspection of Cells. Inspect each cell to see if the level of the electrolyte is at the proper height. This is indicated on the jar by a line marked LIQUID LINE. If the electrolyte is simply a little low and there is no evidence of any having been spilled (examine packing material for discoloration) add distilled or clean rain water to bring the level to the proper height. If the liquid does not cover the plates and the packing material is discolored, it indicates that some or all of the electrolyte has been lost from the cell either on account of a cracked jar or overturning of the battery. If only a small quantity of electrolyte is lost through spilling, the cell should be filled to the proper height with electrolyte of the same specific gravity as in the other cells. This cell should then be charged until the gravity has ceased rising. If all the electrolyte is lost write to the Willard Storage Battery Co., Cleveland, Ohio, for instructions. Connecting the Cells Each cell of the type PH battery is a complete unit, sealed in a glass jar. The cells are to be placed side by side on the battery rack so that the positive terminal of one cell (long connecting strap) can be connected to the negative terminal (short strap) of the adjacent cell. Join the positive terminal of one cell to the negative terminal of the adjacent cell and continue this procedure until all the cells are connected together. This will leave one positive and one negative terminal of the battery to be connected respectively to the positive and negative wires from the switchboard. The bend in the top connector should be made about one inch above the pillar post to eliminate the danger of breakage at the post. In tightening the bolts do not use excessive force, as there is liability of stripping the threads. Give the battery a freshening charge before it is put in service. Type PH cells have a gravity of 1.250 when fully charged, and 1.185 when discharged. Willard Glass Jar Batteries Shipped "Knock-Down." Each sixteen cell set of Batteries consists of: 16 Glass Jars. 16 Positive Groups. 16 Negative Groups. 16 Covers. 16 Vent Plugs. 32 Lead Collars. 32 Lead Keys. 32 Soft Rubber Washers. 32 Hard Rubber Rods. 64 Hard Rubber Nuts. 18 Bolt Connectors. Wood Insulators (the quantity depends upon the size of the cells). Sealing Compound. Hydrometer. Instruction Books. Electrolyte is not supplied with batteries shipped in a knockdown condition. Examine all packing material carefully and check the parts with the above list. Cleaning the Glass Jars Wash the glass jars and wipe them dry. Preparing the Covers Wash the covers and scrub around the under edge to remove all dust. After they are thoroughly dry place them upside down on a bench. Melt the sealing compound and pour it around the outer edge to make a fillet in the groove. Assembling the Element and Separators Place the plates of a positive group between the plates of a negative group and lay the element thus formed on its edge, as shown in Fig. 329. [Fig. 329 Inserting Separators, Willard farm lighting cell] [Fig. 330 and Fig. 331 Fastening cover to posts, Willard farm lighting cell] Next insert a wood separator between each of the positive and negative plates. Next insert the hard rubber rods through the holes in the lugs of the end negative plates, and screw on the nuts. Do not screw the nuts so tight as to make the plates bulge out at the center. The rod should project the same amount on each side of the element. Place the element in a vertical position. The cover can now be placed over the posts. Slip a rubber washer and a lead collar over each post. The two key holes in the lead collar are unequal in size. The collar must be placed over the post so that the end which measures 3/16 inch from the bottom of the holes to the end of the collar will be next to the rubber washer. Dip the lead key in water and then put it through the holes, having the straight edge of the key on the bottom side. This operation can easily be done by using a pair of tongs (see Figs. 330 and 331) to compress the washer. After the keys are driven tight they can be cut off with a pair of end cutters and then smoothed with a file. Sealing Element Assembly in Jar [Fig. 332 Sealing Element Assembly, Willard farm lighting cell] Turn the element upside down and place over a block of wood so that the weight is supported by the cover. (See Fig. 332.) Heat the sealing compound by means of a flame (a blow torch will answer the purpose), and place the jar over the element, as shown in Fig. 331. The jar should be firmly pressed down into the compound. With a hot putty knife, clean off any compound which has oozed out of the joint. The assembled cell can now be turned to an upright position. In case it is necessary to remove a cover, heat a wide putty knife and run it around the edge between the cover and the glass jar. This will soften the compound so that the cover can be pried off. If it is necessary to remove the cover from the posts, the keys must be driven out by pounding on the small end, as the keys are tapered-and the holes in the lead collars are unequal in size. Filling with Electrolyte Fill the cells with 1.260 specific gravity electrolyte at 70° F. to the LIQUID LINE marked on the glass jars. (About I inch above the top edge of separators.) Allow the cells to stand 12 hours, and if the level of the electrolyte has lowered, add sufficient electrolyte to bring it to the proper height. Initial Charge Connect the positive terminal (long strap) of one cell to the negative terminal (short strap) of the adjacent cell and continue this procedure until all the cells are connected together. This will leave one positive and one negative terminal to be connected respectively to the positive and negative wires from the charging source. The bends in the top terminal connectors should be made about one inch above the pillar posts to eliminate the danger of breakage at the post. In tightening the bolts, do not use excessive force, as there is liability of stripping the threads. After the cells have stood for 12 hours with electrolyte in the jars, they should be put on charge at the following rates: Type Amperes ---- ------- PH-7 4 PH-9 5 PH-11 6-1/4 PH-13 7-1/2 PH-15 9 PH-17 10 They should be left on charge continuously until the specific gravity of the electrolyte reaches a maximum and remains constant for six hours. At this point, each cell should be gassing freely and the voltage should read about 2.45 volts per cell, with the above current flowing. Under normal conditions it will require approximately 80 hours to complete the initial charge. The final gravity will be approximately 1.250. If the gravity is above this value, remove a little electrolyte and add the same amount of distilled water. If the gravity is too low, remove a little of the electrolyte and add the same amount of 1.400 specific gravity acid and leave on charge as before. After either water or acid has been added, charge the cells three hours longer in order to thoroughly mix the solution, and if at the end of that time the gravity is between 1.245 and 1.255, the cells are ready for service. It is very important that the initial charge be continued until the specific gravity reaches a maximum value, regardless of the length of time required. The battery must not be discharged until the initial charge has been completed. If it is impossible to charge the battery continuously, the charge can be stopped over night, but must be resumed the next day. It is preferable to charge the battery at the ampere rate given above, but if this cannot be done, the temperature must be carefully watched so that it does not exceed 110° F. Wilard Rubber Jar Batteries Shipped Completely Charged and Filled with Electrolyte Immediately upon receipt of battery, remove the soft rubber nipples and unscrew the vent plugs. The soft rubber nipples are to be discarded, as they are used only for protection during shipment. Inspect each cell to see whether the electrolyte is at the proper height. If the electrolyte is simply a little low and there is no evidence of any having been spilled (examine packing material for discoloration), add distilled water to bring the level to the proper height. If electrolyte does not cover the plates and the packing material is discolored, it indicates that some or all of the electrolyte has been lost from the cell, either on account of cracked jar or overturning of the battery. If only a small quantity of electrolyte is lost through spilling, the cell should be filled to the proper height with electrolyte of the same specific gravity as in the other cells. This cell should then be charged until the gravity has ceased rising, If all the electrolyte is lost, write to the Willard Storage Battery Co., Cleveland, Ohio, for instructions. Place batteries on rack and connect the positive terminal of one crate to the negative terminal of the next crate, using the jumpers furnished. The main battery wires from the switch board should be soldered to the pigtail terminals, which can then be bolted to the battery terminals. Be sure to have the positive and negative battery terminals connected respectively to the positive and negative generator terminals of switchboard. Before using the battery, it should be given a freshening charge at the rate given on page 510. The specific gravity of the rubber jar batteries is 1.285-1.300 when fully charged, and 1.160 when discharged. Willard Rubber Jar Batteries Shipped Dry (Export Batteries) Batteries which have been prepared for export must be given the following treatment: Upon receipt of battery by customer, the special soft rubber nipples, used on the batteries for shipping purposes only, should be removed and discarded. Types SMW and SEW batteries should at once be filled to bottom of vent hole with 1.285 specific gravity electrolyte at 70° F. In mixing electrolyte, the acid should be poured into the water and allowed to cool below 90° F. before being put into the cells. If electrolyte is shipped with the battery, it is of the proper gravity to put into the cells. Immediately after the batteries are filled with electrolyte, they must be placed on charge at one half the normal charging rate given on page 510, and should be left on charge continuously until the specific gravity of the electrolyte stops rising. At this point, each cell should be gassing freely and the voltage should read at least 2.40 volts per cell with one-half the normal charging current flowing. If during the charge the temperature of the electrolyte in any one cell exceeds 105° F., the current must be reduced until the temperature is below 90° F. This will necessitate a longer time to complete the charge, but must be strictly adhered to. Under normal conditions it will require approximately 80 hours to complete the initial charge. The final gravity of the types SMW and SEW will be approximately 1.285. If the gravity is above this value, remove a little electrolyte and add same amount of distilled water while the battery is left charging (in order to thoroughly mix the solution), and after three hours, if the electrolyte is within the limits, the cell is ready for service. If the specific gravity is below these values, remove a little electrolyte and add same amount of 1.400 specific gravity electrolyte. Leave on charge as before. The acid should be poured into the water and allowed to cool below 90° P. before being used. The batteries are then ready for service. Installing Counter Electromotive Force Cells Counter EMF cells, if used with a battery, are installed in the same manner as regular cells. They are connected positive to negative, the same as regular cells, but the negative terminal of the CEMF group is to be connected to the negative terminal of the regular cell group. The positive terminal of the counter CEMF group is then to be connected to the switchboard. [Image: Table of charge and discharge rates for different types of batteries, Willard farm lighting batteries] ======================================================================== Definitions and Descriptions of Terms and Parts ------------------------------- Acid. As used in this book refers to sulphuric acid (H2SO4), the active component of the electrolyte, or a mixture of sulphuric acid and water. Active Material. The active portion of the battery plates; peroxide of lead on the positives and spongy metallic lead on the negatives. Alloy. As used in battery practice, a homogeneous combination of lead and antimony. Alternating Current. Electric current which does not flow in one direction only, like direct current, but rapidly reverses its direction or "alternates" in polarity so that it will not charge a battery. Ampere. The unit of measure of the rate of flow of electric current. Ampere Hour. The product resulting from multiplication of amperes flowing by time of flow in hours, e.g., a battery supplying 10 amperes for 8 hours gives 80 ampere hours. See note under "Volt?" for more complete explanation of current flow. Battery. Two or more electrical cells, electrically connected so that combination furnishes current as a unit. Battery Terminals. Devices attached to the positive post of one end cell and the negative of the other, by means of which the battery is connected to the car circuit. Bridge (or Rib). Wedge-shaped vertical projection from bottom of rubber jar on which plates rest and by which they are supported. Buckling. Warping or bending of the battery plates. Burning. A term used to describe the operation of joining two pieces of lead by melting them at practically the same instant so they may run together as one continuous piece. Usually done with mixture of oxygen and hydrogen or acetylene gases, hydrogen and compressed air, or oxygen and illuminating gas. Burning Strip. A convenient form of lead, in strips, for filling up the joint in making burned connections. Cadmium. A metal used in about the shape of a pencil for obtaining voltage of positive or negative plates. It is dipped in the electrolyte but not allowed to come in contact with plates. Capacity. The number of ampere hours a battery can supply at a given rate of current flow after being fully charged, e.g., a battery may be capable of supplying 10 amperes of current for 8 hours before it is exhausted. Its capacity is 80 ampere hours at the 8 hours rate of current flow. It is necessary to state the rate of flow, since same battery if discharged at 20 amperes would not last for 4 hours but for a shorter period, say 3 hours. Hence, its capacity at the 3 hour rate would be 3x2O=60 ampere hours. Case. The containing box which holds the battery cells. Cell. The battery unit, consisting of an element complete with electrolyte, in its jar with cover. Charge. Passing direct current through a battery in the direction opposite to that of discharge, in order to put back the energy used on discharge. Charge Rate. The proper rate of current to use in charging a battery from an outside source. It is expressed in amperes and varies for different sized cells. Corrosion. The attack of metal parts by acid from the electrolyte; it is the result of lack of cleanliness. Cover. The rubber cover which closes each individual cell; it is flanged for sealing compound to insure an effective seal. Cycle. One charge and discharge. Density. Specific gravity. Developing. The first cycle or cycles of a new or rebuilt battery to bring about proper electrochemical conditions to give rated capacity. Diffusion. Pertaining to movement of acid within the pores of plates. (See Equalization.) Discharge. The flow of current from a battery through a circuit, opposite of "charge." Dry. Term frequently applied to cell containing insufficient electrolyte. Also applied to certain conditions of shipment of batteries. Electrolyte. The conducting fluid of electro-chemical devices; for lead-acid storage batteries it consists of about two parts of water to one of chemically pure sulphuric acid, by weight. Element. Positive group, negative group and separators. Equalization. The result of circulation and diffusion within the cell which accompanies charge and discharge. Difference in capacity at various rates is caused by the time required for this feature. Equalizing. Term used to describe the making uniform of varying specific gravities in different cells of the same battery, by adding or removing water or electrolyte. Evaporation. Loss of water from electrolyte from heat or charging. Filling Plug. The plug which fits in and closes the orifice of the filling tube in the cell cover. Finishing Rate. The current in amperes at which a battery may be charged for twenty-four hours or more. Also the charging rate used near the end of a charge when cells begin to gas. Flooding. Overflowing through the filling tube. Forming. Electro-chemical process of making pasted grid or other plate, types into storage battery plates. (Often confused with Developing.) Foreign Material. Objectionable substances. Freshening Charge. A charge given to a battery which has been standing idle, to keep it fully charged. Gassing. The giving off of oxygen gas at positive plates and hydrogen at negatives, which begins when charge is something more than half completed-depending on the rate. Generator System. An equipment including a generator for automatically recharging the battery, in contradistinction to a straight storage system where the battery has to be removed to be recharged. Gravity. A contraction of the term "specific gravity," which means the density compared to water as a standard. Grid. The metal framework of a plate, supporting the active material and provided with a lug for conducting the current and for attachment to the strap. Group. A set of plates, either positive or negative, joined to a strap. Groups do not include separators. Hold-Down. Device for keeping separators from floating or working up. Hold-Down Clips. Brackets for the attachment of bolts for holding the battery securely in position on the car. Hydrogen Flame. A very hot and clean flame of hydrogen gas and oxygen, acetylene, or compressed air used for making burned connections. Hydrogen Generator. An apparatus for generating hydrogen gas for lead burning. Hydrometer. An instrument for measuring the specific gravity of the electrolyte. Hydrometer Syringe. A glass barrel enclosing a hydrometer and provided with a rubber bulb for drawing up electrolyte. Jar. The hard rubber container holding the element and electrolyte. Lead Burning. Making a joint by melting together the metal of the parts to be joined. Lug. The extension from the top frame of each plate, connecting the plate to the strap. Maximum Gravity. The highest specific gravity which the electrolyte will reach by continued charging, indicating that no acid remains in the plates. Mud. (See Sediment.) Negative. The terminal of a source of electrical energy as a cell, battery or generator through which current returns to complete circuit. Generally marked "Neg." or "-". Ohm. The unit of electrical resistance. The smaller the wire conductor the greater is the resistance. Six hundred and sixty-five feet of No. 14 wire (size used in house lighting circuit) offers I ohm resistance to current flow. Oil of Vitriol. Commercial name for concentrated sulphuric acid (1.835 specific gravity). This is never used in a battery and would quickly ruin it. Over-Discharge. The carrying of discharge beyond proper cell voltage; shortens life if carried far enough and done frequently. Paste. The mixture of lead oxide or spongy lead and other substances which is put into grids. Plate. The combination of grid and paste properly "formed." Positive$ are reddish brown and negatives slate gray. Polarity. An electrical condition. The positive terminal (or pole) of a cell or battery or electrical circuit is said to have positive polarity; the negative, negative polarity. Positive. The terminal of a source of electrical energy as a cell, battery or generator from which the current flows. Generally marked "Pos." or "+". Post. The portion of the strap extending through the cell cover, by means of which connection is made to the adjoining cell or to the car circuit. Potential Difference. Abbreviated P. D. Found on test curves. Synonymous with voltage. Rate. Number of amperes for charge or discharge. Also used to express time for either. Rectifier. Apparatus for converting alternating current into direct current. Resistance. Material (usually lamps or wire) of low conductivity inserted in a circuit to retard the flow of current. By varying the resistance, the amount of current can be regulated. Also the property of an electrical circuit whereby the flow of current is impeded. Resistance is measured in ohms. Analogous to the impediment offered by wall of a pipe to flow of water therein. Rheostat. An electrical appliance used to raise or lower the resistance of a circuit and correspondingly to decrease or increase the current flowing. Rib. (See Bridge.) Ribbed. (See Separator.) Reversal. Reversal of polarity of cell or battery, due to excessive discharge, or charging in the wrong direction. Rubber Sheets. Thin, perforated hard rubber sheets used in combination with the wood separators in some types of batteries. They are placed between the grooved side of the wood separators and the positive plate. Sealing. Making tight joints between jar and cover; usually with a black, thick, acid-proof compound. Sediment. Loosened or worn out particles of active material fallen to the bottom of cells; frequently called "mud." Sediment Space. That part of jar between bottom and top of bridge. Separator. An insulator between plates of opposite polarity; usually of wood, rubber or combination of both. Separators are generally corrugated or ribbed to insure proper distance between plates and to avoid too great displacement of electrolyte. Short Circuit. A metallic connection between the positive and negative plates within a cell. The plates may be in actual contact or material may lodge and bridge across. If the separators are in good condition, a short circuit is unlikely to occur. Spacers. Wood strips used in some types to separate the cells in the case, and divided to provide a space for the tie bolts. Specific Gravity. The density of the electrolyte compared to water as a standard. It indicates the strength and is measured by the hydrometer. Spray. Fine particles of electrolyte carried up from the surface by gas bubbles. (See Gassing.) Starting Rate. A specified current in amperes at which a discharged battery may be charged at the beginning of a charge. The starting rate is reduced to the finishing rate when the cells begin to gas. It is also reduced at any time during the charge if the temperature of the electrolyte rises to or above 110 deg. Fahrenheit. Starvation. The result of giving insufficient charge in relation to the amount of discharge, resulting in poor service and injury to the battery. Strap. The leaden casting to which the plates of a group are joined. Sulphate. Common term for lead sulphate. (PbSO4.) Sulphated. Term used to describe cells in an under-charged condition, from either over-discharging without corresponding long charges or from standing idle some time and being self discharged. Sulphate Reading. A peculiarity of cell voltage when plates are considerably sulphated, where charging voltage shows abnormally high figures before dropping gradually to normal charging voltage. Terminal. Part to which outside wires are connected. Vent, Vent Plug or Vent-Cap. Hard or soft rubber part inserted in cover to retain atmospheric pressure within the cell, while preventing loss of electrolyte from spray. It allows gases formed in the cell to escape, prevents electrolyte from spilling, and keeps dirt out of the cell. Volt. The commercial unit of pressure in an electric circuit. Voltage is measured by a voltmeter. Analogous to pressure or head of water flow through pipes. NOTE.--Just as increase of pressure causes more volume of water to flow through a given pipe so increase of voltage (by putting more cells in circuit) will cause more amperes of current to flow in same circuit. Decreasing size of pipes is increasing resistance and decreases flow of water, so also introduction of resistance in an electrical circuit decreases current flow with a given voltage or pressure. Wall. Jar sides and ends. Washing. Removal of sediment from cells after taking out elements; usually accompanied by rinsing of groups, replacement of wood separators and renewal of electrolyte. Watt. The commercial unit of electrical power, and is the product of voltage of circuit by amperes flowing. One ampere flowing under pressure of one volt represents one watt of power. Watt Hour. The unit of electrical work. It is the product of power expended by time of expenditure, e.g., 10 amperes flowing under 32 volts pressure for 8 hours gives 2560 watt hours. ======================================================================== Index A Acetic acid from improperly treated separators 77 Acetylene and Compressed Air Lead-burning Outfit147 Acid Carboys 184 Acid. Handling and mixing 222 Acid. How lost while battery is on car 57 Acid. How to draw, from carboys 184 Acid should never be added to battery on car 57 Acid used instead of water 57 Active materials. Composition of 13 Active materials. Effect of quantity, porosity, and arrangement of, on capacity 42 Active materials. Resistance of 49 Age codes 242 Age of battery. Determining 242 Age of battery. Effect of, on capacity 47 Alcohol torch lead-burning outfit 148 Applying pastes to grids 11 Arc lead-burning outfit 148 Audion bulb for radio receiving sets 253 B Battery box should be kept clean and dry 51 Battery carrier 173 Battery case (see Case). Battery steamer 158 Battery truck 173 Battery turntable 170 Bench charge 198 to 210 Bench charge. Arrangement of batteries for 200 Bench charge. Charging rates for 201 Bench charge. Conditions preventing batteries from charging 206 Bench charge. Conditions preventing gravity from rising 207 Bench charge. If battery becomes too hot 205 Bench charge. If battery will not hold a charge 208 Bench charge. If battery will not take half a charge 205 Bench charge. If current cannot be passed through battery 206 Bench charge. If electrolyte has a milky appearance 206 Bench charge. If gravity rises above 1.300 205 Bench charge. If gravity rises long before voltage does 205 Bench charge. If new battery will not charge 205 Bench charge. If one cell will not charge 205 Bench charge. If vinegar-like odor is detected 205 Bench charge. Leave vent-plugs in when charging 209 Bench charge. Level of electrolyte at end of 203 Bench charge. Painting case after 203 Bench charge. Specific gravity at end of 203 Bench charge. Specific gravity will not rise to 1.280 204 Bench charge. Suggestions for 209 Bench charge. Temperatures of batteries during 202 Bench charge. Time required for 203 Bench charge. Troubles arising during 204 Bench charge. Voltage at end of 203 Bench charge. When necessary 198 Bins for stock parts 158 Book-keeping records 302 (Omitted) "Bone-dry" batteries. Putting into service 229 Boxes for battery parts 183 Buckling 72 Buckling. Caused by charging at high rates 73 Buckling. Caused by continued operation in discharged condition 73 Buckling. Caused by defective grid alloy 73 Buckling. Caused by non-uniform current distribution 73 Buckling. Caused by overdischarge 73 Buckling does not necessarily cause trouble 73 Burning. (See Lead-Burning.) Burning-lead mould 164 Burning rack 162 Business methods 299 to 312 (Omitted) C Cadmium. What it is 176 Cadmium leads. Connection of, to voltmeter 179 Cadmium readings affected by improperly treated separators 181 Cadmium readings. Conditions necessary to obtain good negative-cadmium readings 210 Cadmium readings do not indicate capacity of a cell 175 Cadmium readings on short-circuited cells 180 Cadmium readings. Troubles shown by, on charge 206 Cadmium readings. When they should be taken 176 Cadmium test 174 Cadmium test. How made 175 Cadmium test on charging battery 181 Cadmium test on discharging battery 180 Cadmium test set. What it consists of 177 Cadmium test voltmeter 178 Calling for repair batteries 314 Capacity. Effect of age of battery on 47 and 89 Capacity. Effect of plate surface area on 42 Capacity. Effect of clogged separators on 88 Capacity. Effect of incorrect proportions of acid and acid in electrolyte on 88 Capacity. Effect of low level of electrolyte on 88 Capacity. Effect of operating conditions on 44 Capacity. Effect of quantity and strength of electrolyte on 42 Capacity. Effect of quantity, arrangement, and porosity of active materials on 42 Capacity. Effect of rate of discharge on 44 Capacity. Effect of reversal of plates on 89 Capacity. Effect of shedding on 88 Capacity. Effect of specific gravity on 43 Capacity. Effect of temperature on 46 Carbon-arc lead-burning outfit 148 Carboys 184 Care of battery on the car 51 to 68 Care of battery when not in service 67 Carrier for batteries 173 Case. Cleaning and painting, after repairs 372 Case manufacture 22 Case. Painting, after bench charge 203 Case. Repairing 360 Case. Troubles indicated by rotted 319 Case troubles 83 Cases. Equipment for work on 98 and 170 Casting plate grids 9 Cell connector mould 168 Cell connectors. Burning-on 213 Cell connectors. Equipment for work on 98 Cell connectors. How to remove 329 Changing pastes into active materials 12 Charge. (See Bench Charge.) Charge. Changes at negative plates during 30 and 39 Charge. Changes at positive plates during 30 and 40 Charge. Changes in acid density during 39 Charge. Changes in voltage during 38 Charge. Loss of, in an idle battery 89 Charge. Preliminary, in rebuilding batteries 349 Charge. Trickle 239 Charging bench133 to 139 Charging bench. Arrangement of batteries on 200 Charging bench. Temperature of batteries on 202 Charging bench. Working drawings of 134 to 139 Charging circuits. Drawings of 105 Charging connections. Making temporary 220 Charging. Constant potential 111 Charging equipment for farm lighting batteries 439 Charging equipment for starting batteries 100 Charging farm lighting batteries 455 Charging. Lamp-banks for 101 Charging. Motor-generators for 106 Charging rate. Adjusting 287 Charging rate. Checking 283 Charging rate. Governed by gassing 112 and 202 Charging rate. How and when to adjust 289 Charging rates for bench charge 112 and 201 Charging rates for new Exide batteries 226 Charging rates for new Philadelphia batteries 228 Charging rates for new Prest-O-Lite batteries 234 Charging rates on the car 283 Charging rebuilt batteries 373 Charging. Rheostats for 101 Chemical actions and electricity. Relations between 31 Chemical changes at the negatives during charge 30 Chemical changes at the positives during charge 30 Chemical changes at the negatives during discharge 29 Chemical changes at the positives during discharge 29 Chemical changes in the battery 27 to 31 Composition of jars 16 Composition of plate grids 9 Compound. Scraping, from covers and jars 334 Compressed air and hydrogen lead-burning outfit 147 Compressed air and illuminating gas lead-burning outfit 149 Condenser for making distilled water 160 Connections. Making temporary, for charging 220 Connectors. (See Cell Connectors.) Connector troubles 84 Constant-potential charging 111 Construction of plate grids 10 Convenient method of adding water 56 Corroded grids 77 Corroded grids. Caused by age 78 Corroded grids. Caused by high temperatures 78 Corroded grids. Caused by impurities 78 Corrosion 321 Covers. Eveready 17 Covers. Exide 19 and 21 Covers. Functions of 16 Covers. Gould 17 Covers. How to remove 331 Covers. Philadelphia diamond grid 16 Covers. Prest-O-Lite 18 and 19 Covers. Putting on the 365 Covers. Sealing 366 Covers. Single and double 16 Covers. Steaming 332 Covers. U.S.L. 18 and 20 Covers. Vesta 18 Covers. Westinghouse 417 Covers. Willard 19 Credit. Use and abuse of 301 (Omitted) Cutout. Checking action of 282? Cycling discharge tests 269 D Dead cells. Causes of 87 Delco-Light batteries 466 Delco-Light batteries. Ampere-hour meter for 467 and 471 Delco-Light batteries. Burning-on new plates of 492 Delco-Light batteries. Burning-on new straps for 488 Delco-Light batteries. Care of cells of, in stock 493 Delco-Light batteries. Charging, after reassembling 481 Delco-Light batteries. Charging outside negatives of 484 Delco-Light batteries. Clearing high resistance shorts in 484 Delco-Light batteries. Clearing lug shorts in 484 Delco-Light batteries. Dis-assembling 474 Delco-Light batteries. Gauges and instruments for testing 466 Delco-Light batteries. General complaints from users of 495 Delco-Light batteries. Hydrometers for 468 Delco-Light batteries. Inspection trips 470 Delco-Light batteries. Pressing negatives of 485 Delco-Light batteries. Putting repaired cells into service 484 Delco-Light batteries. Re-assembling 477 Delco-Light batteries. Removing impurities from 483 Delco-Light batteries. Repairing broken posts of 487 Delco-Light batteries. Repairing lead parts of 486 Delco-Light batteries. Salvaging replaced cells of 486 Delco-Light batteries. Taking, out of commission 494 Delco-Light batteries. Treating broken cells of 482 Delco-Light batteries. Treating spilled cells of 482 Delco-Light batteries. Treating reversed cells of 483 Delco-Light batteries. Use of auxiliary straps with 492 Delco-Light batteries. When and how to charge 468 Discharge apparatus 270 Discharge. Changes at negative plates during 37 Discharge. Changes at positive plates during 37 Discharge. Changes in acid density during 35 Discharge. Chemical actions at negative plates during 29 Discharge. Chemical actions at positive plates during 29 Discharge. Effects of rates of, on capacity 44 Discharge. Voltage changes during 32 Discharge tests. Cycling 269 Discharge tests. Fifteen seconds 266 Discharge tests. Lighting ability 267 Discharge tests. Starting ability 267 Distilled water. Condenser for making 160 Dope electrolytes 59 and 199 Double covers. Sealing 366 Dry shipment of batteries 24 Dry storage 240 Dry storage batteries 265 E Earthenware jars 184 Electrical system. Normal course of operation of 277 Electrical system. Testing the 276 Electrical system. Tests on, to be made by the repairman 279 Electrical system. Troubles in the 284 Electricity and chemical actions. Relation between 31 Electrolyte. Adjusting the 373 Electrolyte below tops of plates. Causes and results of 319 and 323 Electrolyte. Causes of milky appearance of 206 Electrolyte. Composition of 199 and 222 Electrolyte. Correct height of, above plates 55 Electrolyte. Effect of circulation of, on capacity 44 Electrolyte. Effect of low 67 Electrolyte. Effect of quantity and strength of, on capacity 42 Electrolyte. Freezing points of 67 Electrolyte. Leaking of, at top of cells 324 Electrolyte. Level of, at end of bench charge 203 Electrolyte. Resistance of 43 and 48 Electrolyte troubles. High gravity 85 Electrolyte troubles. High level 85 Electrolyte troubles. Low gravity 85 Electrolyte troubles. Low level 85 Electrolyte troubles. Milky appearance 85 Element. Tightening loose 363 Elements. Re-assembling 361 Equipment for discharge tests 270 Equipment for general work 98 Equipment for general work on connectors and terminals 98 Equipment for handling sealing compound 149 Equipment for lead-burning 97 Equipment for work on cases 98 and 170 Equipment needed in opening batteries 97 Equipment which is absolutely necessary 96 Eveready batteries. Claimed to be non-sulphating 401 Eveready batteries. Description of parts 404 Eveready batteries. Rebuilding 405 Examining and testing incoming batteries 317 Exide farm lighting batteries 466 to 498 Exide radio batteries 257 Exide starting batteries. Age code for 243 (Age code chart omitted) Exide starting batteries. Burning-on cell connectors of 382 Exide starting batteries. Capacities of 381 (Chart omitted) Exide starting batteries. Charging, after repairing 382 Exide starting batteries. Methods of holding jars of, in case 377 Exide starting batteries. Opening of 377 Exide starting batteries. Putting cells of, in case 382 Exide starting batteries. Putting jars of, in case 382 Exide starting batteries. Putting new, into service 225 Exide starting batteries. Re-assembling plates of 379 Exide starting batteries. Sealing single covers of 380 Exide starting batteries. Type numbers of 377 Exide starting batteries. Types of 375 Exide starting batteries. Work on plates, separators, jars, and cases of 379 F Farm lighting batteries 435 to 510 Farm lighting batteries. Care of, in operation 453 Farm lighting batteries. Care of plant of, in operation 450 Farm lighting batteries. Charging 453? or (455) Farm lighting batteries. Charging equipment for 439 Farm lighting batteries. Determining condition of cells of 453 Farm lighting batteries. Difference between, and starting batteries 435 Farm lighting batteries. Discharge rules for 457 Farm lighting batteries. Exide 466 Farm lighting batteries. Initial charge of 448 Farm lighting batteries. Installation of plant 445 Farm lighting batteries. Instructing users of 449 Farm lighting batteries. Jars used in 436 Farm lighting batteries. Loads carried by 443 (Charts omitted) Farm lighting batteries. Location of plant 444 Farm lighting batteries. Overcharge of 455 Farm lighting batteries. Power consumed by appliances connected to 442 Farm lighting batteries. Prest-O-Lite 460 Farm lighting batteries. Selection of plant 440 Farm lighting batteries. Separators for 438 Farm lighting batteries. Size of plant required 442 Farm lighting batteries. Specific gravity of electrolyte of 438 Farm lighting batteries. Troubles with 458 Farm lighting batteries. When to charge 455 Farm lighting batteries. Wiring of plant for 444 Filling and testing service 291 Flames for lead-burning 211 Floor. Care of 188 Floor grating for shop 188 Floor of shop 186 Forming plates 11 Freezing points of electrolyte 67 G Gassing causes shedding 74 Gassing. Charging rate governed by 112 and 202 Gassing. Definition of 31 Gassing. Excessive, causes milky appearance of electrolyte 86 Gassing of sulphated plates 40 and 75 Gassing on charge 37? and 202 Granulated negatives 78 Granulated negatives. Caused by age 78 Granulated negatives. Caused by heat 78 Gravity. (See Specific Gravity). Grids. Casting 9 Grids. Composition of 9 Grids. Corroded 77 Grids. Effect of age on 78 and 80 and 342? (344) Grids. Effect of defective grid alloy on 73 Grids. Effect of impurities on 77 and 78 and 80 and 342 Grids. Effect of overheating on 78 and 80 and 342? Grids. Resistance of 48 Grids. Trimming 10 H Handling and mixing acid 222 Heating of negatives exposed to the air 78 High rate discharge testers 181 High rate discharge tests 266 and 267 and 374 Home-made batteries 25 Hydrogen and compressed air lead-burning outfit 147 Hydrogen and oxygen lead-burning outfit 146 Hydrometer. What it consists of 60 Hydrometer readings. Effect of temperature on 65 Hydrometer readings. How to take 61 I Idle battery. Care of 67 Idle battery. How it becomes discharged 89 Idle battery. How it sulphates 70 Illuminating gas and compressed air lead-burning outfit 149 Impurities 76 Impurities which attack the plates 77 Impurities which cause self-discharge 76 Incoming batteries. Examining and testing 317 Incoming batteries. General inspection of 320 Incoming batteries. Operation tests on 320 Incoming batteries. When it is necessary to open 326 Incoming batteries. When it is necessary to remove from car 325 Incoming batteries. When it is unnecessary to open 325 Incoming batteries. When it is unnecessary to remove from car 324 Installing battery on the car 236 Internal resistance 48 to 50 Isolators 408 Inspection to determine height of electrolyte 55 J Jars. Construction of 16 Jars. Filling with electrolyte 364 Jars for farm lighting batteries 436 Jars. Manufacture of 16 Jars. Materials used for 16 Jars. Removing defective 359 Jars. Testing, for leaks 356 Jars. Work on 356 Jar troubles caused by explosion in cell 83 Jar troubles caused by freezing 83 Jar troubles caused by improperly trimmed groups 83 Jar troubles caused by loose battery 82 Jar troubles caused by rough handling 82 Jar troubles caused by weights placed on top of battery 83 K (No Entries) L Lead burning cell connectors 213 Lead burning. Classes of 211 Lead burning. Equipment for 97 and 143 Lead burning. General instructions for 210 to 220 Lead burning plates to straps 217 Lead burning terminals 213 Lead burning. Safety precautions for 213 Lead melting pots 220 Lead mould 164 Lead moulding instructions 220 Light for shop 187 and 190 Loose active material 75 Loose active material caused by buckling 76 Loose active material caused by overdischarge 75 Loss of capacity 88 Loss of charge in an idle battery 89 Lugs. Extending plate 219 M Manufacture of batteries 9 to 26 Manufacture of batteries. Assembling and sealing 23 Manufacture of batteries. Auxiliary rubber separators 15 Manufacture of batteries. Cases 22 Manufacture of batteries. Casting the grid 9 Manufacture of batteries. Composition of the grid 9 Manufacture of batteries. Covers 16 Manufacture of batteries. Drying the pasted plates 12 Manufacture of batteries. Forming the plates 12 Manufacture of batteries. Home-made batteries 25 Manufacture of batteries. Jars 16 Manufacture of batteries. Materials used for separators 14 Manufacture of batteries. Mixing pastes 11 Manufacture of batteries. Paste formulas 11 Manufacture of batteries. Pasting plates 11 Manufacture of batteries. Philco slotted retainer 15 Manufacture of batteries. Post seal 16 Manufacture of batteries. Preparing batteries for dry shipment 24 Manufacture of batteries. Separators 14 Manufacture of batteries. Terminal connections 25 Manufacture of batteries. Treating separators 14 Manufacture of batteries. Trimming the grid 10 Manufacture of batteries. Vent plugs 22 Manufacture of batteries. Vesta impregnated mats 15 Mechanical rectifier 131 Melting pot for lead 220 Mercury-Arc rectifier 129 Milky electrolyte 206 Motor-generators 106 to 112 Motor-generators. Care of 110 Motor-generators. Operating charging circuits of 109 Motor-generators. Sizes for small and large shops 106 Motor-generators. Suggestions on 108 Moulding instructions 220 Moulding materials 220 Moulds. 164 to 170 Moulds for building up posts 165 Moulds for burning lead sticks 164 Moulds for cell connectors 168 Moulds for plate straps 167 and 169 Moulds for terminal screws 168 N Negative plates. Changes at, during charge 39 Negative plates. Changes at, during discharge 37 Negatives. Bulged 79 Negatives. Granulated 78 Negatives. Heating of, when exposed to the air 78 Negatives with roughened surface 79 Negatives with softened active material 79 Negatives with hard active material 79 Negatives. Washing and pressing 351 New batteries. Putting, into service 224 Non-sulphating Eveready batteries 402 O Open-circuits 86 Open-circuits. Caused by acid on soldered joints 86 Open-circuits. Caused by broken terminals 86 Open-circuits. Caused by poor lead burning 86 Opening batteries. Equipment needed in 97 Opening batteries. Heating sealing compound 332 Opening batteries. Instructions for 328 Opening batteries. Pulling elements out of jars 333 Opening batteries. Removing connectors and terminals 329 Opening batteries. Removing post-seal 331 Opening batteries. Scraping compound from covers 334 Opening batteries. When necessary 326 Opening batteries. When unnecessary 325 Operating conditions. Effect of, on capacity 44 Overdischarge causes sulphation 69 Oxides used for plate pastes 11 Oxygen and acetylene lead burning outfit 143 Oxygen and hydrogen lead burning outfit 146 Oxygen and illuminating gas lead burning outfit 146 P Packing batteries for shipping 271 Painting case after bench charge 203 Paraffine dip pot 182 Paste formulas 11 Pastes. Applying to grids 11 Patent electrolytes 59 Philadelphia radio batteries 260 Philadelphia starting batteries. Age codes for 243 Philadelphia starting batteries. Old type post seal for 398 Philadelphia starting batteries. Putting new, into service 228 Philadelphia starting batteries. Rubber cases for 401 Philadelphia starting batteries. Rubber-Lockt seal 399 Philadelphia starting batteries. Separators for 402 Plante plates 27 Plante's work on the storage battery 27 Plate burning-rack 162 Plate lugs. Extending 219 Plate press 171 Plate strap mould 167 and 169 Plate surface area. Effect of, on capacity 42 Plate troubles 69 Plates. Burning, to straps 217 and 355 Plates charged in wrong direction 81 and 343 Plates. Examining, after opening battery 337 Plates. Sulphated 342 Plates. When old, may be used again 344 Plates. When to put in new 339 Positives. Buckled 80 and 341 Positives. Changes at, during charge 40 Positives. Changes at, during discharge 37 Positives. Frozen 80 and 339 Positives. Rotted, and disintegrated 80 and 341 Positives. Washing 354 Positives which have lost considerable active material 80 Positives with hard active material 81 Positives with soft active material. 80 Post builders 165 Post building instructions 218 Post seal 17 Post seal. Exide 19 Post seal. Philadelphia 399 Post seal. Prest-O-Lite 386 Post seal. Titan 434 Post seal. Universal 430 Post seal. U.S.L. 18 Post seal. Vesta 413 Post seal. Westinghouse 417 Post seal. Willard 424 to 428 Posts. Burning, to plates 217 Pots for melting lead 220 Pressing plates 171 Piest-O-Lite farm lighting batteries 460 Prest-O-Lite farm lighting batteries. Descriptions 460 Prest-O-Lite farm lighting batteries. Opening cells 464 Prest-O-Lite farm lighting batteries. Putting repaired cell into service 465 Prest-O-Lite farm lighting batteries. Rebuilding 464 Prest-O-Lite farm lighting batteries. Specific gravity of electrolyte 461 Prest-O-Lite radio batteries 262 Prest-O-Lite starting batteries. Age code for 244 (Omitted) Prest-O-Lite starting batteries. Peening instructions for 395 Prest-O-Lite starting batteries. Old style covers for 386 Prest-O-Lite starting batteries. Peened post seal for 386 Prest-O-Lite starting batteries. Peening posts of 391 and 394 Prest-O-Lite starting batteries. Peening press for 390 Prest-O-Lite starting batteries. Post locking outfit for 388 Prest-O-Lite starting batteries. Putting new into service 233 Prest-O-Lite starting batteries. Rebuilding posts of 393 Prest-O-Lite starting batteries. Removing covers from 392 Prest-O-Lite starting batteries. Tables of 396 (Omitted) Primary cell 5 Purchasing methods 299 (Omitted) Putting new batteries into service 224 Q (No entries) R Radio audion bulb 253 Radio batteries 252 Radio batteries. Exide 257 Radio batteries. General features of 255 Radio batteries. Philadelphia 260 Radio batteries. Prest-O-Lite 262 Radio batteries. Universal 263 Radio batteries. U. S. L. 261 Radio batteries. Vesta 256 Radio batteries. Westinghouse 259 Radio batteries. Willard 257 Radio receiving sets. Types of 252 Rebuilding batteries 328 (to rest of chapter 15) Rebuilding batteries. Adjusting electrolyte 373 Rebuilding batteries. Burning-on cell connectors 371 Rebuilding batteries. Burning-on plates 355 Rebuilding batteries. Charging rebuilt batteries 373 Rebuilding batteries. Cleaning 329 Rebuilding batteries. Cleaning and painting the case 372 Rebuilding batteries. Determining repairs necessary 335 Rebuilding batteries. Eliminating short-circuits 348 Rebuilding batteries. Examining the plates 337 Rebuilding batteries. Filling jars with electrolyte 364 Rebuilding batteries. Heating sealing compound 332 Rebuilding batteries. High rate discharge test 374 Rebuilding batteries. Marking the repaired battery 372 Rebuilding batteries. Preliminary charge 349 Rebuilding batteries. Pressing negatives 351 Rebuilding batteries. Pulling plates out of jars 333 Rebuilding batteries. Putting elements in jars 362 Rebuilding batteries. Putting on the covers 365 Rebuilding batteries. Reassembling the elements 361 Rebuilding batteries. Removing connectors and terminals 329 Rebuilding batteries. Removing defective jars 359 Rebuilding batteries. Removing post seal 331 Rebuilding batteries. Repairing the case 360 Rebuilding batteries. Scraping compound from covers and jars 334 Rebuilding batteries. Sealing double covers 366 Rebuilding batteries. Sealing single covers 371 Rebuilding batteries. Testing jars 356 Rebuilding batteries. Tightening loose elements 363 Rebuilding batteries. Using 1.400 acid 364 Rebuilding batteries. Washing negatives 351 Rebuilding batteries. Washing positives 354 Rebuilding batteries. When old plates may be used again 344 Rebuilding batteries, When to put in new plates 339 Rebuilding batteries. Work on jars 356 Rectifier. Mechanical 131 Rectifier. Mercury are 129 Rectifier. Stahl 132 Rectifier. Tungar 113 Reinsulation 274 Relations between chemical actions and electricity 31 Rental batteries. General policy for 251 Rental batteries. Marking 249 and 296 Rental batteries. Record of 251 Rental batteries. Stock card for 297 (Omitted very simple chart) Rental batteries. Terminals for 248 Reversed plates 81 and 89 Reversed-series generator. Adjusting 290 S S. A. E. ratings for batteries 45 Safety first rules 275 Safety precautions during lead-burning 213 Screw mould .... 168 Sealing around the posts 17 Sealing compound. Composition of 150 Sealing compound. Equipment for handling 149 Sealing compound. Heating with electricity 333 Sealing compound. Heating with gasoline torch 333 Sealing compound. Heating with hot water 332 Sealing compound. Heating with lead burning flame 333 Sealing compound. Heating with steam 332 Sealing compound. Instructions for heating properly 150 Sealing compound. Removing with hot putty knife 332 Secondary cell 5 Sediment. Effect of excessive 87 Separator cutter 171 Separator troubles 81 and 346 Separators for farm lighting batteries 438 Separators. Improperly treated, cause unsatisfactory negative-cadmium readings 181 Separators. Putting in new 274 Separators. Storing 273 Separators. Threaded rubber 430 Service records 293 Shedding 74 Shedding caused by charging only a portion of the plate 75 Shedding caused by charging sulphated plate at too high a rate 74 Shedding caused by excessive charging rate 74 Shedding caused by freezing 75 Shedding caused by overcharging 74 Shedding. Normal 74 Shedding. Result of 74 Shelving and racks 152 Shipping batteries 271 Shop equipment 95 Shop equipment for charging 100 Shop equipment for general work 98 Shop equipment for lead-burning 97 Shop equipment for opening batteries 97 Shop equipment for work on cases 98 Shop equipment for work on connectors and terminals 98 Shop equipment which is absolutely necessary 96 Shop floor 186 187? Shop layouts 187? 189 to 196 Shop light 190? 191 Short-circuits. Eliminating 348 Single covers. Scaling 371 Sink. Working drawings of 144 and 145 Specific gravity at end of bench charge 203 Specific gravity. Changes in, during charge 39 Specific gravity. Changes in, during discharge 35 Specific gravity. Definition of 60 Specific gravity. Effect of, on capacity 43 Specific gravity in farm lighting cells 438 Specific gravity. Limits of, during charge and discharge 43 Specific gravity rises above 1.300 205 Specific gravity rises long before voltage on charge 205 Specific gravity should be measured every two weeks 60 Specific gravity. What determines, of fully charged cell 438 Specific gravity. What different values of, indicate 60 Specific gravity. Why 1.280-1.300 indicates fully charged cell 43 Specific gravity will not rise to 1.280 204 Specific gravity readings. Effect of temperature on 65 Specific gravity readings. How to take 61 Specific gravity readings. If above 1.300 318 and 323 Specific gravity readings. If all above 1.200 318 Specific gravity readings. If below 1.150 in all cells 318 and 321? Specific gravity readings. If between 1.150 and 1.200 in all cells 318 and 321? Specific gravity readings. If unequal 318 and 322 Specific gravity readings. Troubles indicated by 63 Stahl rectifier 132 Starting ability discharge test 267 Steamer 158 Steps in the use of electricity on the automobile 1 Storage battery does not "store" electricity 6 Storage cell 5 Storing batteries dry 240 Storing batteries wet 239 Strap. Burning plates to 217 Strap mould 167 and 169 Sulphate. Effect of, on voltage during discharge 32 Sulphation. Caused by adding acid 72 Sulphation. Caused by battery standing idle 70 Sulphation. Caused by impurities 72 Sulphation. Caused by low electrolyte 71 Sulphation. Caused by overdischarge 69 Sulphation. Caused by overheating 72 Sulphation. Caused by starvation 71 T Temperature. Cause of high, on car 324 Temperature corrections in specific gravity readings 65 Temperature. Effect of, on battery operation 66 Temperature. Effect of, on capacity 46 Temperature of batteries on charging bench 202 Terminal connections 25 Terminals. Burning-on 213 Terminals for rental batteries 248 Testing and examining incoming batteries 317 Testing and filling service 291 Testing the electrical system 276 Third brush generator. Adjusting 289 Threaded rubber separators 430 Time required for bench charge 203 Titan batteries 432 Titan batteries. Age code for 245 (Omitted) Treating separators 14 Trickle charge 239 Trimming plate grids 10 Trouble charts 321 Troubles arising during bench charge 204 Troubles. Battery 69 Trucks for batteries 173 Tungar rectifier. Battery connections of 127 Tungar rectifier. Four battery 119 Tungar rectifier. General instructions for 126 Tungar rectifier. Half-wave and full-wave 114 and 115 Tungar rectifier. Installation of 126 Tungar rectifier. Line connections of 127 Tungar rectifier. One battery 117 Tungar rectifier. Operation of 128 Tungar rectifier. Principle of 113 Tungar rectifier. Ten battery 120 Tungar rectifier. Troubles with 128 Tungar rectifier. Twenty battery 122 Tungar rectifier. Two ampere 116 Tungar rectifier. Two battery 118 Turntable for batteries 170 U Universal radio batteries 263 Universal starting batteries 430 Universal starting batteries. Construction features of 430 Universal starting batteries. Putting new, into service 431 Universal starting batteries. Types 430 U. S. L. radio batteries. 261 U. S. L. starting batteries. Age code for 246 U. S. L. starting batteries. Special instructions for 382 U. S. L. starting batteries. Tables of 384 (Omitted) U. S. L. vent tube construction 20 V Vent plugs should be left in place during charge 209 Vent tube construction 20 Vesta radio batteries 256 Vesta starting batteries 408 Vesta starting batteries. Age code for 246246 Vesta starting batteries. Isolators for 408 Vesta starting batteries. Post seal 413 Vesta starting batteries. Putting new, into service 227 Vesta starting batteries. Separators 413 and 415 Vesta starting batteries. Type D 409 Vesta starting batteries. Type DJ 412 Vibrating regulators. Adjusting 290 Vinegar-like odor. Cause of 205 Voltage. Causes of low 321 Voltage changes during charge 38 Voltage changes during discharge 32 Voltage, limiting value of, on discharge 34 Voltage of cell. Factors determining 34 Voltage of a fully charged cell 203 Voltage readings at end of bench charge 203 Voltage readings on open circuit worthless 177 Voltaic cell 4 W Wash tank. Working drawings of 144 Water. Condenser for distilled 160 Westinghouse farm lighting batteries 498 Westinghouse radio batteries 259 Westinghouse starting batteries 417 Westinghouse starting batteries. Age code for 247247 Westinghouse starting batteries. Plates for 418 Westinghouse starting batteries. Post seal for 417 Westinghouse starting batteries. Putting new, into service 231 Westinghouse starting batteries. Type A 418 Westinghouse starting batteries. Type B 419 Westinghouse starting batteries. Type C 420 Westinghouse starting batteries. Type E 420 Westinghouse starting batteries. Type F 423 Westinghouse starting batteries. Type H 421 Westinghouse starting batteries. Type J 422 Westinghouse starting batteries. Type 0 422 Wet batteries. Putting new, into service 225 Wet storage 239 What's wrong with the battery 313 to 327 When it is unnecessary to open battery 325 When may battery be left on car 324 When must battery be opened 326 When should battery be removed from car 325 Willard farm-lighting batteries 502 Willard radio batteries 257 Willard starting batteries. Age code for 247 Willard starting batteries. Bone-dry 24 Willard starting batteries. Putting new, into service 229 Willard starting batteries with compound sealed post 424 Willard starting batteries with gasket post seal 428 Willard starting batteries with lead cover-inserts 424 Willard threaded-rubber separators 430 Working drawings of bins for stock 158 Working drawings of charging bench 134 to 139 Working drawings of flash-back tank 147 Working drawings of shelving and racks 153 to 157 Working drawings of shop layouts 189 to 196 Working drawings of steamer bench 161 Working drawings of wash tank 144 and 145 Working drawings of work bench 140 and 141 X Y Z (No entries under X, Y or Z) A B C D E F G H I J K L M N O P Q R S T U V W XYZ Index (Table of) Contents ======================================================================== A VISIT TO THE FACTORY ---------------------- THE following pages show how Batteries are made at the Factory. The illustrations will be especially interesting to Battery Service Station Owners who have conceived the idea that they would like to manufacture their own batteries. A completed battery is a simple looking piece of apparatus, yet the equipment needed to make it is elaborate and expensive, as the following illustrations will show. Quantity production is necessary in order to build a good battery at a moderate cost to the car owner, and quantity production means a large factory, elaborate and expensive equipment, and a large working force. Furthermore, before any batteries are put on the market, extensive research and experimentation is necessary to develop a battery which will prove a success in the field. This in itself requires considerable time and money. No manufacturer who has developed formulas and designs at a considerable expense will disclose them to others who desire to enter the manufacturing field as competitors, nor can anyone expect them to do so. If the man who contemplates entering the battery manufacturing business can afford to develop his own formulas and designs, build a factory, and organize a working force, it is, of course, perfectly. proper for him to become a manufacturer; but unless he can do so, he should not attempt to make a battery. The following illustrations, will of course, be of interest to the man who repairs batteries. A knowledge of the manufacturing processes will give him a better understanding of the batteries which he repairs. The less mystery there is about the battery, the more efficiently can the repairman do his work. [Photo: Casting Exide Grids] [Photo: Pasting Exide Plates] [Photo: Casting Small Exide Battery Parts] [Photo: Forming Exide Positive Plates] [Photo: Burning Exide Plates Into Groups] [Photo: Cutting and grooving Exide wood separators] [Photo: Charging Exide batteries] [Photo: Mixing paste for Prest-O-Lite batteries] [Photo: Moulding Prest-O-Lite Grids] [Photo: Inspecting Prest-O-Lite grids for defects] [Photo: Prest-O-Lite pasting room] [Photo: Pasting Prest-O-Lite plates] [Photo: A corner of Prest-O-Lite forming room] [Photo: General view of Prest-O-Lite assembly room] [Photo: Power operated Prest-O-Lite peening press] [Photo: Inspecting Prest-O-Lite separators] [Photo: Inserting separators in Prest-O-Lite plate elements] [Photo: Final inspection of Prest-O-Lite batteries] [Photo: Prest-O-Lite experimental laboratory] [Photo: Laboratory tests of oxides for Vesta batteries] [Photo: Moulding Vesta grids] [Photo: Preparing Vesta plates for the forming room] [Photo: Burning Vesta plates into groups. Assembling groups with isolators.] [Photo: Vesta acid mixing room] [Photo: Checking and adjusting cell readings of Vesta batteries on development charge] [Photo: Final assembly inspection of Vesta batteries] [Photo: Trimming Westinghouse grids] [Photo: Pasting Westinghouse plates] [Photo: Burning Westinghouse plates into groups] [Photo: Packing Westinghouse batteries for shipment] [Illustration: AMBU Official Service Station] 
874	----	A HISTORY OF AERONAUTICS by E. Charles Vivian FOREWORD Although successful heavier-than-air flight is less than two decades old, and successful dirigible propulsion antedates it by a very short period, the mass of experiment and accomplishment renders any one-volume history of the subject a matter of selection. In addition to the restrictions imposed by space limits, the material for compilation is fragmentary, and, in many cases, scattered through periodical and other publications. Hitherto, there has been no attempt at furnishing a detailed account of how the aeroplane and the dirigible of to-day came to being, but each author who has treated the subject has devoted his attention to some special phase or section. The principal exception to this rule--Hildebrandt--wrote in 1906, and a good many of his statements are inaccurate, especially with regard to heavier-than-air experiment. Such statements as are made in this work are, where possible, given with acknowledgment to the authorities on which they rest. Further acknowledgment is due to Lieut.-Col. Lockwood Marsh, not only for the section on aeroplane development which he has contributed to the work, but also for his kindly assistance and advice in connection with the section on aerostation. The author's thanks are also due to the Royal Aeronautical Society for free access to its valuable library of aeronautical literature, and to Mr A. Vincent Clarke for permission to make use of his notes on the development of the aero engine. In this work is no claim to originality--it has been a matter mainly of compilation, and some stories, notably those of the Wright Brothers and of Santos Dumont, are better told in the words of the men themselves than any third party could tell them. The author claims, however, that this is the first attempt at recording the facts of development and stating, as fully as is possible in the compass of a single volume, how flight and aerostation have evolved. The time for a critical history of the subject is not yet. In the matter of illustrations, it has been found very difficult to secure suitable material. Even the official series of photographs of aeroplanes in the war period is curiously incomplete' and the methods of censorship during that period prevented any complete series being privately collected. Omissions in this respect will probably be remedied in future editions of the work, as fresh material is constantly being located. E.C.V. October, 1920. CONTENTS Part I--THE EVOLUTION OF THE AEROPLANE I. THE PERIOD OF LEGEND II. EARLY EXPERIMENTS III. SIR GEORGE CAYLEY--THOMAS WALKER IV. THE MIDDLE NINETEENTH CENTURY V. WENHAM, LE BRIS, AND SOME OTHERS VI. THE AGE OF THE GIANTS VII. LILIENTHAL AND PILCHER VIII. AMERICAN GLIDING EXPERIMENTS IX. NOT PROVEN X. SAMUEL PIERPOINT LANGLEY XI. THE WRIGHT BROTHERS XII. THE FIRST YEARS OF CONQUEST XIII. FIRST FLIERS IN ENGLAND XIV. RHEIMS, AND AFTER XV. THE CHANNEL CROSSING XVI. LONDON TO MANCHESTER XVII. A SUMMARY--TO 1911 XVIII. A SUMMARY--TO 1914 XIX. THE WAR PERIOD--I XX. THE WAR PERIOD--II XXI. RECONSTRUCTION XXII. 1919-1920 Part II--1903-1920: PROGRESS IN DESIGN I. THE BEGINNINGS II. MULTIPLICITY OF IDEAS III. PROGRESS ON STANDARDISED LINES IV. THE WAR PERIOD Part III--AEROSTATICS I. BEGINNINGS II. THE FIRST DIRIGIBLES III. SANTOS-DUMONT IV. THE MILITARY DIRIGIBLE V. BRITISH AIRSHIP DESIGN VI. THE AIRSHIP COMMERCIALLY VII. KITE BALLOONS PART IV--ENGINE DEVELOPMENT I. THE VERTICAL TYPE II. THE VEE TYPE III. THE RADIAL TYPE IV. THE ROTARY TYPE V. THE HORIZONTALLY-OPPOSED ENGINE VI. THE TWO-STROKE CYCLE ENGINE VII. ENGINES OF THE WAR PERIOD APPENDICES PART I. THE EVOLUTION OF THE AEROPLANE I. THE PERIOD OF LEGEND The blending of fact and fancy which men call legend reached its fullest and richest expression in the golden age of Greece, and thus it is to Greek mythology that one must turn for the best form of any legend which foreshadows history. Yet the prevalence of legends regarding flight, existing in the records of practically every race, shows that this form of transit was a dream of many peoples--man always wanted to fly, and imagined means of flight. In this age of steel, a very great part of the inventive genius of man has gone into devices intended to facilitate transport, both of men and goods, and the growth of civilisation is in reality the facilitation of transit, improvement of the means of communication. He was a genius who first hoisted a sail on a boat and saved the labour of rowing; equally, he who first harnessed ox or dog or horse to a wheeled vehicle was a genius--and these looked up, as men have looked up from the earliest days of all, seeing that the birds had solved the problem of transit far more completely than themselves. So it must have appeared, and there is no age in history in which some dreamers have not dreamed of the conquest of the air; if the caveman had left records, these would without doubt have showed that he, too, dreamed this dream. His main aim, probably, was self-preservation; when the dinosaur looked round the corner, the prehistoric bird got out of the way in his usual manner, and prehistoric man, such of him as succeeded in getting out of the way after his fashion--naturally envied the bird, and concluded that as lord of creation in a doubtful sort of way he ought to have equal facilities. He may have tried, like Simon the Magician, and other early experimenters, to improvise those facilities; assuming that he did, there is the groundwork of much of the older legend with regard to men who flew, since, when history began, legends would be fashioned out of attempts and even the desire to fly, these being compounded of some small ingredient of truth and much exaggeration and addition. In a study of the first beginnings of the art, it is worth while to mention even the earliest of the legends and traditions, for they show the trend of men's minds and the constancy of this dream that has become reality in the twentieth century. In one of the oldest records of the world, the Indian classic Mahabarata, it is stated that 'Krishna's enemies sought the aid of the demons, who built an aerial chariot with sides of iron and clad with wings. The chariot was driven through the sky till it stood over Dwarakha, where Krishna's followers dwelt, and from there it hurled down upon the city missiles that destroyed everything on which they fell.' Here is pure fable, not legend, but still a curious forecast of twentieth century bombs from a rigid dirigible. It is to be noted in this case, as in many, that the power to fly was an attribute of evil, not of good--it was the demons who built the chariot, even as at Friedrichshavn. Mediaeval legend in nearly every case, attributes flight to the aid of evil powers, and incites well-disposed people to stick to the solid earth--though, curiously enough, the pioneers of medieval times were very largely of priestly type, as witness the monk of Malmesbury. The legends of the dawn of history, however, distribute the power of flight with less of prejudice. Egyptian sculpture gives the figure of winged men; the British Museum has made the winged Assyrian bulls familiar to many, and both the cuneiform records of Assyria and the hieroglyphs of Egypt record flights that in reality were never made. The desire fathered the story then, and until Clement Ader either hopped with his Avion, as is persisted by his critics, or flew, as is claimed by his friends. While the origin of many legends is questionable, that of others is easy enough to trace, though not to prove. Among the credulous the significance of the name of a people of Asia Minor, the Capnobates, 'those who travel by smoke,' gave rise to the assertion that Montgolfier was not first in the field--or rather in the air--since surely this people must have been responsible for the first hot-air balloons. Far less questionable is the legend of Icarus, for here it is possible to trace a foundation of fact in the story. Such a tribe as Daedalus governed could have had hardly any knowledge of the rudiments of science, and even their ruler, seeing how easy it is for birds to sustain themselves in the air, might be excused for believing that he, if he fashioned wings for himself, could use them. In that belief, let it be assumed, Daedalus made his wings; the boy, Icarus, learning that his father had determined on an attempt at flight secured the wings and fastened them to his own shoulders. A cliff seemed the likeliest place for a 'take-off,' and Icarus leaped from the cliff edge only to find that the possession of wings was not enough to assure flight to a human being. The sea that to this day bears his name witnesses that he made the attempt and perished by it. In this is assumed the bald story, from which might grow the legend of a wise king who ruled a peaceful people--'judged, sitting in the sun,' as Browning has it, and fashioned for himself wings with which he flew over the sea and where he would, until the prince, Icarus, desired to emulate him. Icarus, fastening the wings to his shoulders with wax, was so imprudent as to fly too near the sun, when the wax melted and he fell, to lie mourned of water-nymphs on the shores of waters thenceforth Icarian. Between what we have assumed to be the base of fact, and the legend which has been invested with such poetic grace in Greek story, there is no more than a century or so of re-telling might give to any event among a people so simple and yet so given to imagery. We may set aside as pure fable the stories of the winged horse of Perseus, and the flights of Hermes as messenger of the gods. With them may be placed the story of Empedocles, who failed to take Etna seriously enough, and found himself caught by an eruption while within the crater, so that, flying to safety in some hurry, he left behind but one sandal to attest that he had sought refuge in space--in all probability, if he escaped at all, he flew, but not in the sense that the aeronaut understands it. But, bearing in mind the many men who tried to fly in historic times, the legend of Icarus and Daedalus, in spite of the impossible form in which it is presented, may rank with the story of the Saracen of Constantinople, or with that of Simon the Magician. A simple folk would naturally idealise the man and magnify his exploit, as they magnified the deeds of some strong man to make the legends of Hercules, and there, full-grown from a mere legend, is the first record of a pioneer of flying. Such a theory is not nearly so fantastic as that which makes the Capnobates, on the strength of their name, the inventors of hot-air balloons. However it may be, both in story and in picture, Icarus and his less conspicuous father have inspired the Caucasian mind, and the world is the richer for them. Of the unsupported myths--unsupported, that is, by even a shadow of probability--there is no end. Although Latin legend approaches nearer to fact than the Greek in some cases, in others it shows a disregard for possibilities which renders it of far less account. Thus Diodorus of Sicily relates that one Abaris travelled round the world on an arrow of gold, and Cassiodorus and Glycas and their like told of mechanical birds that flew and sang and even laid eggs. More credible is the story of Aulus Gellius, who in his Attic Nights tells how Archytas, four centuries prior to the opening of the Christian era, made a wooden pigeon that actually flew by means of a mechanism of balancing weights and the breath of a mysterious spirit hidden within it. There may yet arise one credulous enough to state that the mysterious spirit was precursor of the internal combustion engine, but, however that may be, the pigeon of Archytas almost certainly existed, and perhaps it actually glided or flew for short distances--or else Aulus Gellius was an utter liar, like Cassiodorus and his fellows. In far later times a certain John Muller, better known as Regiomontanus, is stated to have made an artificial eagle which accompanied Charles V. on his entry to and exit from Nuremberg, flying above the royal procession. But, since Muller died in 1436 and Charles was born in 1500, Muller may be ruled out from among the pioneers of mechanical flight, and it may be concluded that the historian of this event got slightly mixed in his dates. Thus far, we have but indicated how one may draw from the richest stores from which the Aryan mind draws inspiration, the Greek and Latin mythologies and poetic adaptations of history. The existing legends of flight, however, are not thus to be localised, for with two possible exceptions they belong to all the world and to every civilisation, however primitive. The two exceptions are the Aztec and the Chinese; regarding the first of these, the Spanish conquistadores destroyed such civilisation as existed in Tenochtitlan so thoroughly that, if legend of flight was among the Aztec records, it went with the rest; as to the Chinese, it is more than passing strange that they, who claim to have known and done everything while the first of history was shaping, even to antedating the discovery of gunpowder that was not made by Roger Bacon, have not yet set up a claim to successful handling of a monoplane some four thousand years ago, or at least to the patrol of the Gulf of Korea and the Mongolian frontier by a forerunner of the 'blimp.' The Inca civilisation of Peru yields up a myth akin to that of Icarus, which tells how the chieftain Ayar Utso grew wings and visited the sun--it was from the sun, too, that the founders of the Peruvian Inca dynasty, Manco Capac and his wife Mama Huella Capac, flew to earth near Lake Titicaca, to make the only successful experiment in pure tyranny that the world has ever witnessed. Teutonic legend gives forth Wieland the Smith, who made himself a dress with wings and, clad in it, rose and descended against the wind and in spite of it. Indian mythology, in addition to the story of the demons and their rigid dirigible, already quoted, gives the story of Hanouam, who fitted himself with wings by means of which he sailed in the air and, according to his desire, landed in the sacred Lauka. Bladud, the ninth king of Britain, is said to have crowned his feats of wizardry by making himself wings and attempting to fly--but the effort cost him a broken neck. Bladud may have been as mythic as Uther, and again he may have been a very early pioneer. The Finnish epic, 'Kalevala,' tells how Ilmarinen the Smith 'forged an eagle of fire,' with 'boat's walls between the wings,' after which he 'sat down on the bird's back and bones,' and flew. Pure myths, these, telling how the desire to fly was characteristic of every age and every people, and how, from time to time, there arose an experimenter bolder than his fellows, who made some attempt to translate desire into achievement. And the spirit that animated these pioneers, in a time when things new were accounted things accursed, for the most part, has found expression in this present century in the utter daring and disregard of both danger and pain that stamps the flying man, a type of humanity differing in spirit from his earthbound fellows as fully as the soldier differs from the priest. Throughout mediaeval times, records attest that here and there some man believed in and attempted flight, and at the same time it is clear that such were regarded as in league with the powers of evil. There is the half-legend, half-history of Simon the Magician, who, in the third year of the reign of Nero announced that he would raise himself in the air, in order to assert his superiority over St Paul. The legend states that by the aid of certain demons whom he had prevailed on to assist him, he actually lifted himself in the air--but St Paul prayed him down again. He slipped through the claws of the demons and fell headlong on the Forum at Rome, breaking his neck. The 'demons' may have been some primitive form of hot-air balloon, or a glider with which the magician attempted to rise into the wind; more probably, however, Simon threatened to ascend and made the attempt with apparatus as unsuitable as Bladud's wings, paying the inevitable penalty. Another version of the story gives St Peter instead of St Paul as the one whose prayers foiled Simon--apart from the identity of the apostle, the two accounts are similar, and both define the attitude of the age toward investigation and experiment in things untried. Another and later circumstantial story, with similar evidence of some fact behind it, is that of the Saracen of Constantinople, who, in the reign of the Emperor Comnenus--some little time before Norman William made Saxon Harold swear away his crown on the bones of the saints at Rouen--attempted to fly round the hippodrome at Constantinople, having Comnenus among the great throng who gathered to witness the feat. The Saracen chose for his starting-point a tower in the midst of the hippodrome, and on the top of the tower he stood, clad in a long white robe which was stiffened with rods so as to spread and catch the breeze, waiting for a favourable wind to strike on him. The wind was so long in coming that the spectators grew impatient. 'Fly, O Saracen!' they called to him. 'Do not keep us waiting so long while you try the wind!' Comnenus, who had present with him the Sultan of the Turks, gave it as his opinion that the experiment was both dangerous and vain, and, possibly in an attempt to controvert such statement, the Saracen leaned into the wind and 'rose like a bird 'at the outset. But the record of Cousin, who tells the story in his Histoire de Constantinople, states that 'the weight of his body having more power to drag him down than his artificial wings had to sustain him, he broke his bones, and his evil plight was such that he did not long survive.' Obviously, the Saracen was anticipating Lilienthal and his gliders by some centuries; like Simon, a genuine experimenter--both legends bear the impress of fact supporting them. Contemporary with him, and belonging to the history rather than the legends of flight, was Oliver, the monk of Malmesbury, who in the year 1065 made himself wings after the pattern of those supposed to have been used by Daedalus, attaching them to his hands and feet and attempting to fly with them. Twysden, in his Historiae Anglicanae Scriptores X, sets forth the story of Oliver, who chose a high tower as his starting-point, and launched himself in the air. As a matter of course, he fell, permanently injuring himself, and died some time later. After these, a gap of centuries, filled in by impossible stories of magical flight by witches, wizards, and the like--imagination was fertile in the dark ages, but the ban of the church was on all attempt at scientific development, especially in such a matter as the conquest of the air. Yet there were observers of nature who argued that since birds could raise themselves by flapping their wings, man had only to make suitable wings, flap them, and he too would fly. As early as the thirteenth century Roger Bacon, the scientific friar of unbounded inquisitiveness and not a little real genius, announced that there could be made 'some flying instrument, so that a man sitting in the middle and turning some mechanism may put in motion some artificial wings which may beat the air like a bird flying.' But being a cautious man, with a natural dislike for being burnt at the stake as a necromancer through having put forward such a dangerous theory, Roger added, 'not that I ever knew a man who had such an instrument, but I am particularly acquainted with the man who contrived one.' This might have been a lame defence if Roger had been brought to trial as addicted to black arts; he seems to have trusted to the inadmissibility of hearsay evidence. Some four centuries later there was published a book entitled Perugia Augusta, written by one C. Crispolti of Perugia--the date of the work in question is 1648. In it is recorded that 'one day, towards the close of the fifteenth century, whilst many of the principal gentry had come to Perugia to honour the wedding of Giovanni Paolo Baglioni, and some lancers were riding down the street by his palace, Giovanni Baptisti Danti unexpectedly and by means of a contrivance of wings that he had constructed proportionate to the size of his body took off from the top of a tower near by, and with a horrible hissing sound flew successfully across the great Piazza, which was densely crowded. But (oh, horror of an unexpected accident!) he had scarcely flown three hundred paces on his way to a certain point when the mainstay of the left wing gave way, and, being unable to support himself with the right alone, he fell on a roof and was injured in consequence. Those who saw not only this flight, but also the wonderful construction of the framework of the wings, said--and tradition bears them out--that he several times flew over the waters of Lake Thrasimene to learn how he might gradually come to earth. But, notwithstanding his great genius, he never succeeded.' This reads circumstantially enough, but it may be borne in mind that the date of writing is more than half a century later than the time of the alleged achievement--the story had had time to round itself out. Danti, however, is mentioned by a number of writers, one of whom states that the failure of his experiment was due to the prayers of some individual of a conservative turn of mind, who prayed so vigorously that Danti fell appropriately enough on a church and injured himself to such an extent as to put an end to his flying career. That Danti experimented, there is little doubt, in view of the volume of evidence on the point, but the darkness of the Middle Ages hides the real truth as to the results of his experiments. If he had actually flown over Thrasimene, as alleged, then in all probability both Napoleon and Wellington would have had air scouts at Waterloo. Danti's story may be taken as fact or left as fable, and with it the period of legend or vague statement may be said to end--the rest is history, both of genuine experimenters and of charlatans. Such instances of legend as are given here are not a tithe of the whole, but there is sufficient in the actual history of flight to bar out more than this brief mention of the legends, which, on the whole, go farther to prove man's desire to fly than his study and endeavour to solve the problems of the air. II. EARLY EXPERIMENTS So far, the stories of the development of flight are either legendary or of more or less doubtful authenticity, even including that of Danti, who, although a man of remarkable attainments in more directions than that of attempted flight, suffers--so far as reputation is concerned--from the inexactitudes of his chroniclers; he may have soared over Thrasimene, as stated, or a mere hop with an ineffectual glider may have grown with the years to a legend of gliding flight. So far, too, there is no evidence of the study that the conquest of the air demanded; such men as made experiments either launched themselves in the air from some height with made-up wings or other apparatus, and paid the penalty, or else constructed some form of machine which would not leave the earth, and then gave up. Each man followed his own way, and there was no attempt--without the printing press and the dissemination of knowledge there was little possibility of attempt--on the part of any one to benefit by the failures of others. Legend and doubtful history carries up to the fifteenth century, and then came Leonardo da Vinci, first student of flight whose work endures to the present day. The world knows da Vinci as artist; his age knew him as architect, engineer, artist, and scientist in an age when science was a single study, comprising all knowledge from mathematics to medicine. He was, of course, in league with the devil, for in no other way could his range of knowledge and observation be explained by his contemporaries; he left a Treatise on the Flight of Birds in which are statements and deductions that had to be rediscovered when the Treatise had been forgotten--da Vinci anticipated modern knowledge as Plato anticipated modern thought, and blazed the first broad trail toward flight. One Cuperus, who wrote a Treatise on the Excellence of Man, asserted that da Vinci translated his theories into practice, and actually flew, but the statement is unsupported. That he made models, especially on the helicopter principle, is past question; these were made of paper and wire, and actuated by springs of steel wire, which caused them to lift themselves in the air. It is, however, in the theories which he put forward that da Vinci's investigations are of greatest interest; these prove him a patient as well as a keen student of the principles of flight, and show that his manifold activities did not prevent him from devoting some lengthy periods to observations of bird flight. 'A bird,' he says in his Treatise, 'is an instrument working according to mathematical law, which instrument it is within the capacity of man to reproduce with all its movements, but not with a corresponding degree of strength, though it is deficient only in power of maintaining equilibrium. We may say, therefore, that such an instrument constructed by man is lacking in nothing except the life of the bird, and this life must needs be supplied from that of man. The life which resides in the bird's members will, without doubt, better conform to their needs than will that of a man which is separated from them, and especially in the almost imperceptible movements which produce equilibrium. But since we see that the bird is equipped for many apparent varieties of movement, we are able from this experience to deduce that the most rudimentary of these movements will be capable of being comprehended by man's understanding, and that he will to a great extent be able to provide against the destruction of that instrument of which he himself has become the living principle and the propeller.' In this is the definite belief of da Vinci that man is capable of flight, together with a far more definite statement of the principles by which flight is to be achieved than any which had preceded it--and for that matter, than many that have succeeded it. Two further extracts from his work will show the exactness of his observations:-- 'When a bird which is in equilibrium throws the centre of resistance of the wings behind the centre of gravity, then such a bird will descend with its head downward. This bird which finds itself in equilibrium shall have the centre of resistance of the wings more forward than the bird's centre of gravity; then such a bird will fall with its tail turned toward the earth.' And again: 'A man, when flying, shall be free from the waist up, that he may be able to keep himself in equilibrium as he does in a boat, so that the centre of his gravity and of the instrument may set itself in equilibrium and change when necessity requires it to the changing of the centre of its resistance.' Here, in this last quotation, are the first beginnings of the inherent stability which proved so great an advance in design, in this twentieth century. But the extracts given do not begin to exhaust the range of da Vinci's observations and deductions. With regard to bird flight, he observed that so long as a bird keeps its wings outspread it cannot fall directly to earth, but must glide down at an angle to alight--a small thing, now that the principle of the plane in opposition to the air is generally grasped, but da Vinci had to find it out. From observation he gathered how a bird checks its own speed by opposing tail and wing surface to the direction of flight, and thus alights at the proper 'landing speed.' He proved the existence of upward air currents by noting how a bird takes off from level earth with wings outstretched and motionless, and, in order to get an efficient substitute for the natural wing, he recommended that there be used something similar to the membrane of the wing of a bat--from this to the doped fabric of an aeroplane wing is but a small step, for both are equally impervious to air. Again, da Vinci recommended that experiments in flight be conducted at a good height from the ground, since, if equilibrium be lost through any cause, the height gives time to regain it. This recommendation, by the way, received ample support in the training areas of war pilots. Man's muscles, said da Vinci, are fully sufficient to enable him to fly, for the larger birds, he noted, employ but a small part of their strength in keeping themselves afloat in the air--by this theory he attempted to encourage experiment, just as, when his time came, Borelli reached the opposite conclusion and discouraged it. That Borelli was right--so far--and da Vinci wrong, detracts not at all from the repute of the earlier investigator, who had but the resources of his age to support investigations conducted in the spirit of ages after. His chief practical contributions to the science of flight--apart from numerous drawings which have still a value--are the helicopter or lifting screw, and the parachute. The former, as already noted, he made and proved effective in model form, and the principle which he demonstrated is that of the helicopter of to-day, on which sundry experimenters work spasmodically, in spite of the success of the plane with its driving propeller. As to the parachute, the idea was doubtless inspired by observation of the effect a bird produced by pressure of its wings against the direction of flight. Da Vinci's conclusions, and his experiments, were forgotten easily by most of his contemporaries; his Treatise lay forgotten for nearly four centuries, overshadowed, mayhap, by his other work. There was, however, a certain Paolo Guidotti of Lucca, who lived in the latter half of the sixteenth century, and who attempted to carry da Vinci's theories--one of them, at least, into practice. For this Guidotti, who was by profession an artist and by inclination an investigator, made for himself wings, of which the framework was of whalebone; these he covered with feathers, and with them made a number of gliding flights, attaining considerable proficiency. He is said in the end to have made a flight of about four hundred yards, but this attempt at solving the problem ended on a house roof, where Guidotti broke his thigh bone. After that, apparently, he gave up the idea of flight, and went back to painting. One other a Venetian architect named Veranzio, studied da Vinci's theory of the parachute, and found it correct, if contemporary records and even pictorial presentment are correct. Da Vinci showed his conception of a parachute as a sort of inverted square bag; Veranzio modified this to a 'sort of square sail extended by four rods of equal size and having four cords attached at the corners,' by means of which 'a man could without danger throw himself from the top of a tower or any high place. For though at the moment there may be no wind, yet the effort of his falling will carry up the wind, which the sail will hold, by which means he does not fall suddenly but descends little by little. The size of the sail should be measured to the man.' By this last, evidently, Veranzio intended to convey that the sheet must be of such content as would enclose sufficient air to support the weight of the parachutist. Veranzio made his experiments about 1617-1618, but, naturally, they carried him no farther than the mere descent to earth, and since a descent is merely a descent, it is to be conjectured that he soon got tired of dropping from high roofs, and took to designing architecture instead of putting it to such a use. With the end of his experiments the work of da Vinci in relation to flying became neglected for nearly four centuries. Apart from these two experimenters, there is little to record in the matter either of experiment or study until the seventeenth century. Francis Bacon, it is true, wrote about flying in his Sylva Sylvarum, and mentioned the subject in the New Atlantis, but, except for the insight that he showed even in superficial mention of any specific subject, he does not appear to have made attempt at serious investigation. 'Spreading of Feathers, thin and close and in great breadth will likewise bear up a great Weight,' says Francis, 'being even laid without Tilting upon the sides.' But a lesser genius could have told as much, even in that age, and though the great Sir Francis is sometimes adduced as one of the early students of the problems of flight, his writings will not sustain the reputation. The seventeenth century, however, gives us three names, those of Borelli, Lana, and Robert Hooke, all of which take definite place in the history of flight. Borelli ranks as one of the great figures in the study of aeronautical problems, in spite of erroneous deductions through which he arrived at a purely negative conclusion with regard to the possibility of human flight. Borelli was a versatile genius. Born in 1608, he was practically contemporary with Francesco Lana, and there is evidence that he either knew or was in correspondence with many prominent members of the Royal Society of Great Britain, more especially with John Collins, Dr Wallis, and Henry Oldenburgh, the then Secretary of the Society. He was author of a long list of scientific essays, two of which only are responsible for his fame, viz., Theorice Medicaearum Planetarum, published in Florence, and the better known posthumous De Motu Animalium. The first of these two is an astronomical study in which Borelli gives evidence of an instinctive knowledge of gravitation, though no definite expression is given of this. The second work, De Motu Animalium, deals with the mechanical action of the limbs of birds and animals and with a theory of the action of the internal organs. A section of the first part of this work, called De Volatu, is a study of bird flight; it is quite independent of Da Vinci's earlier work, which had been forgotten and remained unnoticed until near on the beginning of practical flight. Marey, in his work, La Machine Animale, credits Borelli with the first correct idea of the mechanism of flight. He says: 'Therefore we must be allowed to render to the genius of Borelli the justice which is due to him, and only claim for ourselves the merit of having furnished the experimental demonstration of a truth already suspected.' In fact, all subsequent studies on this subject concur in making Borelli the first investigator who illustrated the purely mechanical theory of the action of a bird's wings. Borelli's study is divided into a series of propositions in which he traces the principles of flight, and the mechanical actions of the wings of birds. The most interesting of these are the propositions in which he sets forth the method in which birds move their wings during flight and the manner in which the air offers resistance to the stroke of the wing. With regard to the first of these two points he says: 'When birds in repose rest on the earth their wings are folded up close against their flanks, but when wishing to start on their flight they first bend their legs and leap into the air. Whereupon the joints of their wings are straightened out to form a straight line at right angles to the lateral surface of the breast, so that the two wings, outstretched, are placed, as it were, like the arms of a cross to the body of the bird. Next, since the wings with their feathers attached form almost a plane surface, they are raised slightly above the horizontal, and with a most quick impulse beat down in a direction almost perpendicular to the wing-plane, upon the underlying air; and to so intense a beat the air, notwithstanding it to be fluid, offers resistance, partly by reason of its natural inertia, which seeks to retain it at rest, and partly because the particles of the air, compressed by the swiftness of the stroke, resist this compression by their elasticity, just like the hard ground. Hence the whole mass of the bird rebounds, making a fresh leap through the air; whence it follows that flight is simply a motion composed of successive leaps accomplished through the air. And I remark that a wing can easily beat the air in a direction almost perpendicular to its plane surface, although only a single one of the corners of the humerus bone is attached to the scapula, the whole extent of its base remaining free and loose, while the greater transverse feathers are joined to the lateral skin of the thorax. Nevertheless the wing can easily revolve about its base like unto a fan. Nor are there lacking tendon ligaments which restrain the feathers and prevent them from opening farther, in the same fashion that sheets hold in the sails of ships. No less admirable is nature's cunning in unfolding and folding the wings upwards, for she folds them not laterally, but by moving upwards edgewise the osseous parts wherein the roots of the feathers are inserted; for thus, without encountering the air's resistance the upward motion of the wing surface is made as with a sword, hence they can be uplifted with but small force. But thereafter when the wings are twisted by being drawn transversely and by the resistance of the air, they are flattened as has been declared and will be made manifest hereafter.' Then with reference to the resistance to the air of the wings he explains: 'The air when struck offers resistance by its elastic virtue through which the particles of the air compressed by the wing-beat strive to expand again. Through these two causes of resistance the downward beat of the wing is not only opposed, but even caused to recoil with a reflex movement; and these two causes of resistance ever increase the more the down stroke of the wing is maintained and accelerated. On the other hand, the impulse of the wing is continuously diminished and weakened by the growing resistance. Hereby the force of the wing and the resistance become balanced; so that, manifestly, the air is beaten by the wing with the same force as the resistance to the stroke.' He concerns himself also with the most difficult problem that confronts the flying man of to-day, namely, landing effectively, and his remarks on this subject would be instructive even to an air pilot of these days: 'Now the ways and means by which the speed is slackened at the end of a flight are these. The bird spreads its wings and tail so that their concave surfaces are perpendicular to the direction of motion; in this way, the spreading feathers, like a ship's sail, strike against the still air, check the speed, and so that most of the impetus may be stopped, the wings are flapped quickly and strongly forward, inducing a contrary motion, so that the bird absolutely or very nearly stops.' At the end of his study Borelli came to a conclusion which militated greatly against experiment with any heavier-than-air apparatus, until well on into the nineteenth century, for having gone thoroughly into the subject of bird flight he states distinctly in his last proposition on the subject that 'It is impossible that men should be able to fly craftily by their own strength.' This statement, of course, remains true up to the present day for no man has yet devised the means by which he can raise himself in the air and maintain himself there by mere muscular effort. From the time of Borelli up to the development of the steam engine it may be said that flight by means of any heavier-than-air apparatus was generally regarded as impossible, and apart from certain deductions which a little experiment would have shown to be doomed to failure, this method of flight was not followed up. It is not to be wondered at, when Borelli's exaggerated estimate of the strength expended by birds in proportion to their weight is borne in mind; he alleged that the motive force in birds' wings is 10,000 times greater than the resistance of their weight, and with regard to human flight he remarks:-- 'When, therefore, it is asked whether men may be able to fly by their own strength, it must be seen whether the motive power of the pectoral muscles (the strength of which is indicated and measured by their size) is proportionately great, as it is evident that it must exceed the resistance of the weight of the whole human body 10,000 times, together with the weight of enormous wings which should be attached to the arms. And it is clear that the motive power of the pectoral muscles in men is much less than is necessary for flight, for in birds the bulk and weight of the muscles for flapping the wings are not less than a sixth part of the entire weight of the body. Therefore, it would be necessary that the pectoral muscles of a man should weigh more than a sixth part of the entire weight of his body; so also the arms, by flapping with the wings attached, should be able to exert a power 10,000 times greater than the weight of the human body itself. But they are far below such excess, for the aforesaid pectoral muscles do not equal a hundredth part of the entire weight of a man. Wherefore either the strength of the muscles ought to be increased or the weight of the human body must be decreased, so that the same proportion obtains in it as exists in birds. Hence it is deducted that the Icarian invention is entirely mythical because impossible, for it is not possible either to increase a man's pectoral muscles or to diminish the weight of the human body; and whatever apparatus is used, although it is possible to increase the momentum, the velocity or the power employed can never equal the resistance; and therefore wing flapping by the contraction of muscles cannot give out enough power to carry up the heavy body of a man.' It may be said that practically all the conclusions which Borelli reached in his study were negative. Although contemporary with Lana, he perceived the one factor which rendered Lana's project for flight by means of vacuum globes an impossibility--he saw that no globe could be constructed sufficiently light for flight, and at the same time sufficiently strong to withstand the pressure of the outside atmosphere. He does not appear to have made any experiments in flying on his own account, having, as he asserts most definitely, no faith in any invention designed to lift man from the surface of the earth. But his work, from which only the foregoing short quotations can be given, is, nevertheless, of indisputable value, for he settled the mechanics of bird flight, and paved the way for those later investigators who had, first, the steam engine, and later the internal combustion engine--two factors in mechanical flight which would have seemed as impossible to Borelli as would wireless telegraphy to a student of Napoleonic times. On such foundations as his age afforded Borelli built solidly and well, so that he ranks as one of the greatest--if not actually the greatest--of the investigators into this subject before the age of steam. The conclusion, that 'the motive force in birds' wings is apparently ten thousand times greater than the resistance of their weight,' is erroneous, of course, but study of the translation from which the foregoing excerpt is taken will show that the error detracts very little from the value of the work itself. Borelli sets out very definitely the mechanism of flight, in such fashion that he who runs may read. His reference to 'the use of a large vessel,' etc., concerns the suggestion made by Francesco Lana, who antedated Borelli's publication of De Motu Animalium by some ten years with his suggestion for an 'aerial ship,' as he called it. Lana's mind shows, as regards flight, a more imaginative twist; Borelli dived down into first causes, and reached mathematical conclusions; Lana conceived a theory and upheld it--theoretically, since the manner of his life precluded experiment. Francesco Lana, son of a noble family, was born in 1631; in 1647 he was received as a novice into the Society of Jesus at Rome, and remained a pious member of the Jesuit society until the end of his life. He was greatly handicapped in his scientific investigations by the vows of poverty which the rules of the Order imposed on him. He was more scientist than priest all his life; for two years he held the post of Professor of Mathematics at Ferrara, and up to the time of his death, in 1687, he spent by far the greater part of his time in scientific research, He had the dubious advantage of living in an age when one man could cover the whole range of science, and this he seems to have done very thoroughly. There survives an immense work of his entitled, Magisterium Naturae et Artis, which embraces the whole field of scientific knowledge as that was developed in the period in which Lana lived. In an earlier work of his, published in Brescia in 1670, appears his famous treatise on the aerial ship, a problem which Lana worked out with thoroughness. He was unable to make practical experiments, and thus failed to perceive the one insuperable drawback to his project--of which more anon. Only extracts from the translation of Lana's work can be given here, but sufficient can be given to show fully the means by which he designed to achieve the conquest of the air. He begins by mention of the celebrated pigeon of Archytas the Philosopher, and advances one or two theories with regard to the way in which this mechanical bird was constructed, and then he recites, apparently with full belief in it, the fable of Regiomontanus and the eagle that he is said to have constructed to accompany Charles V. on his entry into Nuremberg. In fact, Lana starts his work with a study of the pioneers of mechanical flying up to his own time, and then outlines his own devices for the construction of mechanical birds before proceeding to detail the construction of the aerial ship. Concerning primary experiments for this he says:-- 'I will, first of all, presuppose that air has weight owing to the vapours and halations which ascend from the earth and seas to a height of many miles and surround the whole of our terraqueous globe; and this fact will not be denied by philosophers, even by those who may have but a superficial knowledge, because it can be proven by exhausting, if not all, at any rate the greater part of, the air contained in a glass vessel, which, if weighed before and after the air has been exhausted, will be found materially reduced in weight. Then I found out how much the air weighed in itself in the following manner. I procured a large vessel of glass, whose neck could be closed or opened by means of a tap, and holding it open I warmed it over a fire, so that the air inside it becoming rarified, the major part was forced out; then quickly shutting the tap to prevent the re-entry I weighed it; which done, I plunged its neck in water, resting the whole of the vessel on the surface of the water, then on opening the tap the water rose in the vessel and filled the greater part of it. I lifted the neck out of the water, released the water contained in the vessel, and measured and weighed its quantity and density, by which I inferred that a certain quantity of air had come out of the vessel equal in bulk to the quantity of water which had entered to refill the portion abandoned by the air. I again weighed the vessel, after I had first of all well dried it free of all moisture, and found it weighed one ounce more whilst it was full of air than when it was exhausted of the greater part, so that what it weighed more was a quantity of air equal in volume to the water which took its place. The water weighed 640 ounces, so I concluded that the weight of air compared with that of water was 1 to 640--that is to say, as the water which filled the vessel weighed 640 ounces, so the air which filled the same vessel weighed one ounce.' Having thus detailed the method of exhausting air from a vessel, Lana goes on to assume that any large vessel can be entirely exhausted of nearly all the air contained therein. Then he takes Euclid's proposition to the effect that the superficial area of globes increases in the proportion of the square of the diameter, whilst the volume increases in the proportion of the cube of the same diameter, and he considers that if one only constructs the globe of thin metal, of sufficient size, and exhausts the air in the manner that he suggests, such a globe will be so far lighter than the surrounding atmosphere that it will not only rise, but will be capable of lifting weights. Here is Lana's own way of putting it:-- 'But so that it may be enabled to raise heavier weights and to lift men in the air, let us take double the quantity of copper, 1,232 square feet, equal to 308 lbs. of copper; with this double quantity of copper we could construct a vessel of not only double the capacity, but of four times the capacity of the first, for the reason shown by my fourth supposition. Consequently the air contained in such a vessel will be 718 lbs. 4 2/3 ounces, so that if the air be drawn out of the vessel it will be 410 lbs. 4 2/3 ounces lighter than the same volume of air, and, consequently, will be enabled to lift three men, or at least two, should they weigh more than eight pesi each. It is thus manifest that the larger the ball or vessel is made, the thicker and more solid can the sheets of copper be made, because, although the weight will increase, the capacity of the vessel will increase to a greater extent and with it the weight of the air therein, so that it will always be capable to lift a heavier weight. From this it can be easily seen how it is possible to construct a machine which, fashioned like unto a ship, will float on the air.' With four globes of these dimensions Lana proposed to make an aerial ship of the fashion shown in his quaint illustration. He is careful to point out a method by which the supporting globes for the aerial ship may be entirely emptied of air; (this is to be done by connecting to each globe a tube of copper which is 'at least a length of 47 modern Roman palm).' A small tap is to close this tube at the end nearest the globe, and then vessel and tube are to be filled with water, after which the tube is to be immersed in water and the tap opened, allowing the water to run out of the vessel, while no air enters. The tap is then closed before the lower end of the tube is removed from the water, leaving no air at all in the globe or sphere. Propulsion of this airship was to be accomplished by means of sails, and also by oars. Lana antedated the modern propeller, and realised that the air would offer enough resistance to oars or paddle to impart motion to any vessel floating in it and propelled by these means, although he did not realise the amount of pressure on the air which would be necessary to accomplish propulsion. As a matter of fact, he foresaw and provided against practically all the difficulties that would be encountered in the working, as well as the making, of the aerial ship, finally coming up against what his religious training made an insuperable objection. This, again, is best told in his own words:-- 'Other difficulties I do not foresee that could prevail against this invention, save one only, which to me seems the greatest of them all, and that is that God would surely never allow such a machine to be successful, since it would create many disturbances in the civil and political governments of mankind.' He ends by saying that no city would be proof against surprise, while the aerial ship could set fire to vessels at sea, and destroy houses, fortresses, and cities by fire balls and bombs. In fact, at the end of his treatise on the subject, he furnishes a pretty complete resume of the activities of German Zeppelins. As already noted, Lana himself, owing to his vows of poverty, was unable to do more than put his suggestions on paper, which he did with a thoroughness that has procured him a place among the really great pioneers of flying. It was nearly 200 years before any attempt was made to realise his project; then, in 1843, M. Marey Monge set out to make the globes and the ship as Lana detailed them. Monge's experiments cost him the sum of 25,000 francs 75 centimes, which he expended purely from love of scientific investigation. He chose to make his globes of brass, about.004 in thickness, and weighing 1.465 lbs. to the square yard. Having made his sphere of this metal, he lined it with two thicknesses of tissue paper, varnished it with oil, and set to work to empty it of air. This, however, he never achieved, for such metal is incapable of sustaining the pressure of the outside air, as Lana, had he had the means to carry out experiments, would have ascertained. M. Monge's sphere could never be emptied of air sufficiently to rise from the earth; it ended in the melting-pot, ignominiously enough, and all that Monge got from his experiment was the value of the scrap metal and the satisfaction of knowing that Lana's theory could never be translated into practice. Robert Hooke is less conspicuous than either Borelli or Lana; his work, which came into the middle of the seventeenth century, consisted of various experiments with regard to flight, from which emerged 'a Module, which by the help of Springs and Wings, raised and sustained itself in the air.' This must be reckoned as the first model flying machine which actually flew, except for da Vinci's helicopters; Hooke's model appears to have been of the flapping-wing type--he attempted to copy the motion of birds, but found from study and experiment that human muscles were not sufficient to the task of lifting the human body. For that reason, he says, 'I applied my mind to contrive a way to make artificial muscles,' but in this he was, as he expresses it, 'frustrated of my expectations.' Hooke's claim to fame rests mainly on his successful model; the rest of his work is of too scrappy a nature to rank as a serious contribution to the study of flight. Contemporary with Hooke was one Allard, who, in France, undertook to emulate the Saracen of Constantinople to a certain extent. Allard was a tight-rope dancer who either did or was said to have done short gliding flights--the matter is open to question--and finally stated that he would, at St Germains, fly from the terrace in the king's presence. He made the attempt, but merely fell, as did the Saracen some centuries before, causing himself serious injury. Allard cannot be regarded as a contributor to the development of aeronautics in any way, and is only mentioned as typical of the way in which, up to the time of the Wright brothers, flying was regarded. Even unto this day there are many who still believe that, with a pair of wings, man ought to be able to fly, and that the mathematical data necessary to effective construction simply do not exist. This attitude was reasonable enough in an unlearned age, and Allard was one--a little more conspicuous than the majority--among many who made experiment in ignorance, with more or less danger to themselves and without practical result of any kind. The seventeenth century was not to end, however, without practical experiment of a noteworthy kind in gliding flight. Among the recruits to the ranks of pioneers was a certain Besnier, a locksmith of Sable, who somewhere between 1675 and 1680 constructed a glider of which a crude picture has come down to modern times. The apparatus, as will be seen, consisted of two rods with hinged flaps, and the original designer of the picture seems to have had but a small space in which to draw, since obviously the flaps must have been much larger than those shown. Besnier placed the rods on his shoulders, and worked the flaps by cords attached to his hands and feet--the flaps opened as they fell, and closed as they rose, so the device as a whole must be regarded as a sort of flapping glider. Having by experiment proved his apparatus successful, Besnier promptly sold it to a travelling showman of the period, and forthwith set about constructing a second set, with which he made gliding flights of considerable height and distance. Like Lilienthal, Besnier projected himself into space from some height, and then, according to the contemporary records, he was able to cross a river of considerable size before coming to earth. It does not appear that he had any imitators, or that any advantage whatever was taken of his experiments; the age was one in which he would be regarded rather as a freak exhibitor than as a serious student, and possibly, considering his origin and the sale of his first apparatus to such a client, he regarded the matter himself as more in the nature of an amusement than as a discovery. Borelli, coming at the end of the century, proved to his own satisfaction and that of his fellows that flapping wing flight was an impossibility; the capabilities of the plane were as yet undreamed, and the prime mover that should make the plane available for flight was deep in the womb of time. Da Vinci's work was forgotten--flight was an impossibility, or at best such a useless show as Besnier was able to give. The eighteenth century was almost barren of experiment. Emanuel Swedenborg, having invented a new religion, set about inventing a flying machine, and succeeded theoretically, publishing the result of his investigations as follows:-- 'Let a car or boat or some like object be made of light material such as cork or bark, with a room within it for the operator. Secondly, in front as well as behind, or all round, set a widely-stretched sail parallel to the machine forming within a hollow or bend which could be reefed like the sails of a ship. Thirdly, place wings on the sides, to be worked up and down by a spiral spring, these wings also to be hollow below in order to increase the force and velocity, take in the air, and make the resistance as great as may be required. These, too, should be of light material and of sufficient size; they should be in the shape of birds' wings, or the sails of a windmill, or some such shape, and should be tilted obliquely upwards, and made so as to collapse on the upward stroke and expand on the downward. Fourth, place a balance or beam below, hanging down perpendicularly for some distance with a small weight attached to its end, pendent exactly in line with the centre of gravity; the longer this beam is, the lighter must it be, for it must have the same proportion as the well-known vectis or steel-yard. This would serve to restore the balance of the machine if it should lean over to any of the four sides. Fifthly, the wings would perhaps have greater force, so as to increase the resistance and make the flight easier, if a hood or shield were placed over them, as is the case with certain insects. Sixthly, when the sails are expanded so as to occupy a great surface and much air, with a balance keeping them horizontal, only a small force would be needed to move the machine back and forth in a circle, and up and down. And, after it has gained momentum to move slowly upwards, a slight movement and an even bearing would keep it balanced in the air and would determine its direction at will.' The only point in this worthy of any note is the first device for maintaining stability automatically--Swedenborg certainly scored a point there. For the rest, his theory was but theory, incapable of being put to practice--he does not appear to have made any attempt at advance beyond the mere suggestion. Some ten years before his time the state of knowledge with regard to flying in Europe was demonstrated by an order granted by the King of Portugal to Friar Lourenzo de Guzman, who claimed to have invented a flying machine capable of actual flight. The order stated that 'In order to encourage the suppliant to apply himself with zeal toward the improvement of the new machine, which is capable of producing the effects mentioned by him, I grant unto him the first vacant place in my College of Barcelos or Santarem, and the first professorship of mathematics in my University of Coimbra, with the annual pension of 600,000 reis during his life.--Lisbon, 17th of March, 1709.' What happened to Guzman when the non-existence of the machine was discovered is one of the things that is well outside the province of aeronautics. He was charlatan pure and simple, as far as actual flight was concerned, though he had some ideas respecting the design of hot-air balloons, according to Tissandier. (La Navigation Aerienne.) His flying machine was to contain, among other devices, bellows to produce artificial wind when the real article failed, and also magnets in globes to draw the vessel in an upward direction and maintain its buoyancy. Some draughtsman, apparently gifted with as vivid imagination as Guzman himself, has given to the world an illustration of the hypothetical vessel; it bears some resemblance to Lana's aerial ship, from which fact one draws obvious conclusions. A rather amusing claim to solving the problem of flight was made in the middle of the eighteenth century by one Grimaldi, a 'famous and unique Engineer' who, as a matter of actual fact, spent twenty years in missionary work in India, and employed the spare time that missionary work left him in bringing his invention to a workable state. The invention is described as a 'box which with the aid of clockwork rises in the air, and goes with such lightness and strong rapidity that it succeeds in flying a journey of seven leagues in an hour. It is made in the fashion of a bird; the wings from end to end are 25 feet in extent. The body is composed of cork, artistically joined together and well fastened with metal wire, covered with parchment and feathers. The wings are made of catgut and whalebone, and covered also with the same parchment and feathers, and each wing is folded in three seams. In the body of the machine are contained thirty wheels of unique work, with two brass globes and little chains which alternately wind up a counterpoise; with the aid of six brass vases, full of a certain quantity of quicksilver, which run in some pulleys, the machine is kept by the artist in due equilibrium and balance. By means, then, of the friction between a steel wheel adequately tempered and a very heavy and surprising piece of lodestone, the whole is kept in a regulated forward movement, given, however, a right state of the winds, since the machine cannot fly so much in totally calm weather as in stormy. This prodigious machine is directed and guided by a tail seven palmi long, which is attached to the knees and ankles of the inventor by leather straps; by stretching out his legs, either to the right or to the left, he moves the machine in whichever direction he pleases.... The machine's flight lasts only three hours, after which the wings gradually close themselves, when the inventor, perceiving this, goes down gently, so as to get on his own feet, and then winds up the clockwork and gets himself ready again upon the wings for the continuation of a new flight. He himself told us that if by chance one of the wheels came off or if one of the wings broke, it is certain he would inevitably fall rapidly to the ground, and, therefore, he does not rise more than the height of a tree or two, as also he only once put himself in the risk of crossing the sea, and that was from Calais to Dover, and the same morning he arrived in London.' And yet there are still quite a number of people who persist in stating that Bleriot was the first man to fly across the Channel! A study of the development of the helicopter principle was published in France in 1868, when the great French engineer Paucton produced his Theorie de la Vis d'Archimede. For some inexplicable reason, Paucton was not satisfied with the term 'helicopter,' but preferred to call it a 'pterophore,' a name which, so far as can be ascertained, has not been adopted by any other writer or investigator. Paucton stated that, since a man is capable of sufficient force to overcome the weight of his own body, it is only necessary to give him a machine which acts on the air 'with all the force of which it is capable and at its utmost speed,' and he will then be able to lift himself in the air, just as by the exertion of all his strength he is able to lift himself in water. 'It would seem,' says Paucton, 'that in the pterophore, attached vertically to a carriage, the whole built lightly and carefully assembled, he has found something that will give him this result in all perfection. In construction, one would be careful that the machine produced the least friction possible, and naturally it ought to produce little, as it would not be at all complicated. The new Daedalus, sitting comfortably in his carriage, would by means of a crank give to the pterophore a suitable circular (or revolving) speed. This single pterophore would lift him vertically, but in order to move horizontally he should be supplied with a tail in the shape of another pterophore. When he wished to stop for a little time, valves fixed firmly across the end of the space between the blades would automatically close the openings through which the air flows, and change the pterophore into an unbroken surface which would resist the flow of air and retard the fall of the machine to a considerable degree.' The doctrine thus set forth might appear plausible, but it is based on the common misconception that all the force which might be put into the helicopter or 'pterophore' would be utilised for lifting or propelling the vehicle through the air, just as a propeller uses all its power to drive a ship through water. But, in applying such a propelling force to the air, most of the force is utilised in maintaining aerodynamic support--as a matter of fact, more force is needed to maintain this support than the muscle of man could possibly furnish to a lifting screw, and even if the helicopter were applied to a full-sized, engine-driven air vehicle, the rate of ascent would depend on the amount of surplus power that could be carried. For example, an upward lift of 1,000 pounds from a propeller 15 feet in diameter would demand an expenditure of 50 horse-power under the best possible conditions, and in order to lift this load vertically through such atmospheric pressure as exists at sea-level or thereabouts, an additional 20 horsepower would be required to attain a rate of 11 feet per second--50 horse-power must be continually provided for the mere support of the load, and the additional 20 horse-power must be continually provided in order to lift it. Although, in model form, there is nothing quite so strikingly successful as the helicopter in the range of flying machines, yet the essential weight increases so disproportionately to the effective area that it is necessary to go but very little beyond model dimensions for the helicopter to become quite ineffective. That is not to say that the lifting screw must be totally ruled out so far as the construction of aircraft is concerned. Much is still empirical, so far as this branch of aeronautics is concerned, and consideration of the structural features of a propeller goes to show that the relations of essential weight and effective area do not altogether apply in practice as they stand in theory. Paucton's dream, in some modified form, may yet become reality--it is only so short a time ago as 1896 that Lord Kelvin stated he had not the smallest molecule of faith in aerial navigation, and since the whole history of flight consists in proving the impossible possible, the helicopter may yet challenge the propelled plane surface for aerial supremacy. It does not appear that Paucton went beyond theory, nor is there in his theory any advance toward practical flight--da Vinci could have told him as much as he knew. He was followed by Meerwein, who invented an apparatus apparently something between a flapping wing machine and a glider, consisting of two wings, which were to be operated by means of a rod; the venturesome one who would fly by means of this apparatus had to lie in a horizontal position beneath the wings to work the rod. Meerwein deserves a place of mention, however, by reason of his investigations into the amount of surface necessary to support a given weight. Taking that weight at 200 pounds--which would allow for the weight of a man and a very light apparatus--he estimated that 126 square feet would be necessary for support. His pamphlet, published at Basle in 1784, shows him to have been a painstaking student of the potentialities of flight. Jean-Pierre Blanchard, later to acquire fame in connection with balloon flight, conceived and described a curious vehicle, of which he even announced trials as impending. His trials were postponed time after time, and it appears that he became convinced in the end of the futility of his device, being assisted to such a conclusion by Lalande, the astronomer, who repeated Borelli's statement that it was impossible for man ever to fly by his own strength. This was in the closing days of the French monarchy, and the ascent of the Montgolfiers' first hot-air balloon in 1783--which shall be told more fully in its place--put an end to all French experiments with heavier-than-air apparatus, though in England the genius of Cayley was about to bud, and even in France there were those who understood that ballooning was not true flight. III. SIR GEORGE CAYLEY--THOMAS WALKER On the fifth of June, 1783, the Montgolfiers' hot-air balloon rose at Versailles, and in its rising divided the study of the conquest of the air into two definite parts, the one being concerned with the propulsion of gas lifted, lighter-than-air vehicles, and the other being crystallised in one sentence by Sir George Cayley: 'The whole problem,' he stated, 'is confined within these limits, viz.: to make a surface support a given weight by the application of power to the resistance of the air.' For about ten years the balloon held the field entirely, being regarded as the only solution of the problem of flight that man could ever compass. So definite for a time was this view on the eastern side of the Channel that for some years practically all the progress that was made in the development of power-driven planes was made in Britain. In 1800 a certain Dr Thomas Young demonstrated that certain curved surfaces suspended by a thread moved into and not away from a horizontal current of air, but the demonstration, which approaches perilously near to perpetual motion if the current be truly horizontal, has never been successfully repeated, so that there is more than a suspicion that Young's air-current was NOT horizontal. Others had made and were making experiments on the resistance offered to the air by flat surfaces, when Cayley came to study and record, earning such a place among the pioneers as to win the title of 'father of British aeronautics.' Cayley was a man in advance of his time, in many ways. Of independent means, he made the grand tour which was considered necessary to the education of every young man of position, and during this excursion he was more engaged in studies of a semi-scientific character than in the pursuits that normally filled such a period. His various writings prove that throughout his life aeronautics was the foremost subject in his mind; the Mechanic's Magazine, Nicholson's Journal, the Philosophical Magazine, and other periodicals of like nature bear witness to Cayley's continued research into the subject of flight. He approached the subject after the manner of the trained scientist, analysing the mechanical properties of air under chemical and physical action. Then he set to work to ascertain the power necessary for aerial flight, and was one of the first to enunciate the fallacy of the hopes of successful flight by means of the steam engine of those days, owing to the fact that it was impossible to obtain a given power with a given weight. Yet his conclusions on this point were not altogether negative, for as early as 1810 he stated that he could construct a balloon which could travel with passengers at 20 miles an hour--he was one of the first to consider the possibilities of applying power to a balloon. Nearly thirty years later--in 1837--he made the first attempt at establishing an aeronautical society, but at that time the power-driven plane was regarded by the great majority as an absurd dream of more or less mad inventors, while ballooning ranked on about the same level as tight-rope walking, being considered an adjunct to fairs and fetes, more a pastime than a study. Up to the time of his death, in 1857, Cayley maintained his study of aeronautical matters, and there is no doubt whatever that his work went far in assisting the solution of the problem of air conquest. His principal published work, a monograph entitled Aerial Navigation, has been republished in the admirable series of 'Aeronautical Classics' issued by the Royal Aeronautical Society. He began this work by pointing out the impossibility of flying by means of attached wings, an impossibility due to the fact that, while the pectoral muscles of a bird account for more than two-thirds of its whole muscular strength, in a man the muscles available for flying, no matter what mechanism might be used, would not exceed one-tenth of his total strength. Cayley did not actually deny the possibility of a man flying by muscular effort, however, but stated that 'the flight of a strong man by great muscular exertion, though a curious and interesting circumstance, inasmuch as it will probably be the means of ascertaining finis power and supplying the basis whereon to improve it, would be of little use.' From this he goes on to the possibility of using a Boulton and Watt steam engine to develop the power necessary for flight, and in this he saw a possibility of practical result. It is worthy of note that in this connection he made mention of the forerunner of the modern internal combustion engine; 'The French,' he said, 'have lately shown the great power produced by igniting inflammable powders in closed vessels, and several years ago an engine was made to work in this country in a similar manner by inflammation of spirit of tar.' In a subsequent paragraph of his monograph he anticipates almost exactly the construction of the Lenoir gas engine, which came into being more than fifty-five years after his monograph was published. Certain experiments detailed in his work were made to ascertain the size of the surface necessary for the support of any given weight. He accepted a truism of to-day in pointing out that in any matters connected with aerial investigation, theory and practice are as widely apart as the poles. Inclined at first to favour the helicopter principle, he finally rejected this in favour of the plane, with which he made numerous experiments. During these, he ascertained the peculiar advantages of curved surfaces, and saw the necessity of providing both vertical and horizontal rudders in order to admit of side steering as well as the control of ascent and descent, and for preserving equilibrium. He may be said to have anticipated the work of Lilienthal and Pilcher, since he constructed and experimented with a fixed surface glider. 'It was beautiful,' he wrote concerning this, 'to see this noble white bird sailing majestically from the top of a hill to any given point of the plain below it with perfect steadiness and safety, according to the set of its rudder, merely by its own weight, descending at an angle of about eight degrees with the horizon.' It is said that he once persuaded his gardener to trust himself in this glider for a flight, but if Cayley himself ventured a flight in it he has left no record of the fact. The following extract from his work, Aerial Navigation, affords an instance of the thoroughness of his investigations, and the concluding paragraph also shows his faith in the ultimate triumph of mankind in the matter of aerial flight:-- 'The act of flying requires less exertion than from the appearance is supposed. Not having sufficient data to ascertain the exact degree of propelling power exerted by birds in the act of flying, it is uncertain what degree of energy may be required in this respect for vessels of aerial navigation; yet when we consider the many hundreds of miles of continued flight exerted by birds of passage, the idea of its being only a small effort is greatly corroborated. To apply the power of the first mover to the greatest advantage in producing this effect is a very material point. The mode universally adopted by Nature is the oblique waft of the wing. We have only to choose between the direct beat overtaking the velocity of the current, like the oar of a boat, or one applied like the wing, in some assigned degree of obliquity to it. Suppose 35 feet per second to be the velocity of an aerial vehicle, the oar must be moved with this speed previous to its being able to receive any resistance; then if it be only required to obtain a pressure of one-tenth of a lb. upon each square foot it must exceed the velocity of the current 7.3 feet per second. Hence its whole velocity must be 42.5 feet per second. Should the same surface be wafted downward like a wing with the hinder edge inclined upward in an angle of about 50 deg. 40 feet to the current it will overtake it at a velocity of 3.5 feet per second; and as a slight unknown angle of resistance generates a lb. pressure per square foot at this velocity, probably a waft of a little more than 4 feet per second would produce this effect, one-tenth part of which would be the propelling power. The advantage of this mode of application compared with the former is rather more than ten to one. 'In continuing the general principles of aerial navigation, for the practice of the art, many mechanical difficulties present themselves which require a considerable course of skilfully applied experiments before they can be overcome; but, to a certain extent, the air has already been made navigable, and no one who has seen the steadiness with which weights to the amount of ten stone (including four stone, the weight of the machine) hover in the air can doubt of the ultimate accomplishment of this object.' This extract from his work gives but a faint idea of the amount of research for which Cayley was responsible. He had the humility of the true investigator in scientific problems, and so far as can be seen was never guilty of the great fault of so many investigators in this subject--that of making claims which he could not support. He was content to do, and pass after having recorded his part, and although nearly half a century had to pass between the time of his death and the first actual flight by means of power-driven planes, yet he may be said to have contributed very largely to the solution of the problem, and his name will always rank high in the roll of the pioneers of flight. Practically contemporary with Cayley was Thomas Walker, concerning whom little is known save that he was a portrait painter of Hull, where was published his pamphlet on The Art of Flying in 1810, a second and amplified edition being produced, also in Hull, in 1831. The pamphlet, which has been reproduced in extenso in the Aeronautical Classics series published by the Royal Aeronautical Society, displays a curious mixture of the true scientific spirit and colossal conceit. Walker appears to have been a man inclined to jump to conclusions, which carried him up to the edge of discovery and left him vacillating there. The study of the two editions of his pamphlet side by side shows that their author made considerable advances in the practicability of his designs in the 21 intervening years, though the drawings which accompany the text in both editions fail to show anything really capable of flight. The great point about Walker's work as a whole is its suggestiveness; he did not hesitate to state that the 'art' of flying is as truly mechanical as that of rowing a boat, and he had some conception of the necessary mechanism, together with an absolute conviction that he knew all there was to be known. 'Encouraged by the public,' he says, 'I would not abandon my purpose of making still further exertions to advance and complete an art, the discovery of the TRUE PRINCIPLES (the italics are Walker's own) of which, I trust, I can with certainty affirm to be my own.' The pamphlet begins with Walker's admiration of the mechanism of flight as displayed by birds. 'It is now almost twenty years,' he says, 'since I was first led to think, by the study of birds and their means of flying, that if an artificial machine were formed with wings in exact imitation of the mechanism of one of those beautiful living machines, and applied in the very same way upon the air, there could be no doubt of its being made to fly, for it is an axiom in philosophy that the same cause will ever produce the same effect.' With this he confesses his inability to produce the said effect through lack of funds, though he clothes this delicately in the phrase 'professional avocations and other circumstances.' Owing to this inability he published his designs that others might take advantage of them, prefacing his own researches with a list of the very early pioneers, and giving special mention to Friar Bacon, Bishop Wilkins, and the Portuguese friar, De Guzman. But, although he seems to suggest that others should avail themselves of his theoretical knowledge, there is a curious incompleteness about the designs accompanying his work, and about the work itself, which seems to suggest that he had more knowledge to impart than he chose to make public--or else that he came very near to complete solution of the problem of flight, and stayed on the threshold without knowing it. After a dissertation upon the history and strength of the condor, and on the differences between the weights of birds, he says: 'The following observations upon the wonderful difference in the weight of some birds, with their apparent means of supporting it in their flight, may tend to remove some prejudices against my plan from the minds of some of my readers. The weight of the humming-bird is one drachm, that of the condor not less than four stone. Now, if we reduce four stone into drachms we shall find the condor is 14,336 times as heavy as the humming-bird. What an amazing disproportion of weight! Yet by the same mechanical use of its wings the condor can overcome the specific gravity of its body with as much ease as the little humming-bird. But this is not all. We are informed that this enormous bird possesses a power in its wings, so far exceeding what is necessary for its own conveyance through the air, that it can take up and fly away with a whole sheer in its talons, with as much ease as an eagle would carry off, in the same manner, a hare or a rabbit. This we may readily give credit to, from the known fact of our little kestrel and the sparrow-hawk frequently flying off with a partridge, which is nearly three times the weight of these rapacious little birds.' After a few more observations he arrives at the following conclusion: 'By attending to the progressive increase in the weight of birds, from the delicate little humming-bird up to the huge condor, we clearly discover that the addition of a few ounces, pounds, or stones, is no obstacle to the art of flying; the specific weight of birds avails nothing, for by their possessing wings large enough, and sufficient power to work them, they can accomplish the means of flying equally well upon all the various scales and dimensions which we see in nature. Such being a fact, in the name of reason and philosophy why shall not man, with a pair of artificial wings, large enough, and with sufficient power to strike them upon the air, be able to produce the same effect?' Walker asserted definitely and with good ground that muscular effort applied without mechanism is insufficient for human flight, but he states that if an aeronautical boat were constructed so that a man could sit in it in the same manner as when rowing, such a man would be able to bring into play his whole bodily strength for the purpose of flight, and at the same time would be able to get an additional advantage by exerting his strength upon a lever. At first he concluded there must be expansion of wings large enough to resist in a sufficient degree the specific gravity of whatever is attached to them, but in the second edition of his work he altered this to 'expansion of flat passive surfaces large enough to reduce the force of gravity so as to float the machine upon the air with the man in it.' The second requisite is strength enough to strike the wings with sufficient force to complete the buoyancy and give a projectile motion to the machine. Given these two requisites, Walker states definitely that flying must be accomplished simply by muscular exertion. 'If we are secure of these two requisites, and I am very confident we are, we may calculate upon the success of flight with as much certainty as upon our walking.' Walker appears to have gained some confidence from the experiments of a certain M. Degen, a watchmaker of Vienna, who, according to the Monthly Magazine of September, 1809, invented a machine by means of which a person might raise himself into the air. The said machine, according to the magazine, was formed of two parachutes which might be folded up or extended at pleasure, while the person who worked them was placed in the centre. This account, however, was rather misleading, for the magazine carefully avoided mention of a balloon to which the inventor fixed his wings or parachutes. Walker, knowing nothing of the balloon, concluded that Degen actually raised himself in the air, though he is doubtful of the assertion that Degen managed to fly in various directions, especially against the wind. Walker, after considering Degen and all his works, proceeds to detail his own directions for the construction of a flying machine, these being as follows: 'Make a car of as light material as possible, but with sufficient strength to support a man in it; provide a pair of wings about four feet each in length; let them be horizontally expanded and fastened upon the top edge of each side of the car, with two joints each, so as to admit of a vertical motion to the wings, which motion may be effected by a man sitting and working an upright lever in the middle of the car. Extend in the front of the car a flat surface of silk, which must be stretched out and kept fixed in a passive state; there must be the same fixed behind the car; these two surfaces must be perfectly equal in length and breadth and large enough to cover a sufficient quantity of air to support the whole weight as nearly in equilibrium as possible, thus we shall have a great sustaining power in those passive surfaces and the active wings will propel the car forward.' A description of how to launch this car is subsequently given: 'It becomes necessary,' says the theorist, 'that I should give directions how it may be launched upon the air, which may be done by various means; perhaps the following method may be found to answer as well as any: Fix a poll upright in the earth, about twenty feet in height, with two open collars to admit another poll to slide upwards through them; let there be a sliding platform made fast upon the top of the sliding poll; place the car with a man in it upon the platform, then raise the platform to the height of about thirty feet by means of the sliding poll, let the sliding poll and platform suddenly fall down, the car will then be left upon the air, and by its pressing the air a projectile force will instantly propel the car forward; the man in the car must then strike the active wings briskly upon the air, which will so increase the projectile force as to become superior to the force of gravitation, and if he inclines his weight a little backward, the projectile impulse will drive the car forward in an ascending direction. When the car is brought to a sufficient altitude to clear the tops of hills, trees, buildings, etc., the man, by sitting a little forward on his seat, will then bring the wings upon a horizontal plane, and by continuing the action of the wings he will be impelled forward in that direction. To descend, he must desist from striking the wings, and hold them on a level with their joints; the car will then gradually come down, and when it is within five or six feet of the ground the man must instantly strike the wings downwards, and sit as far back as he can; he will by this means check the projectile force, and cause the car to alight very gently with a retrograde motion. The car, when up in the air, may be made to turn to the right or to the left by forcing out one of the fins, having one about eighteen inches long placed vertically on each side of the car for that purpose, or perhaps merely by the man inclining the weight of his body to one side.' Having stated how the thing is to be done, Walker is careful to explain that when it is done there will be in it some practical use, notably in respect of the conveyance of mails and newspapers, or the saving of life at sea, or for exploration, etc. It might even reduce the number of horses kept by man for his use, by means of which a large amount of land might be set free for the growth of food for human consumption. At the end of his work Walker admits the idea of steam power for driving a flying machine in place of simple human exertion, but he, like Cayley, saw a drawback to this in the weight of the necessary engine. On the whole, he concluded, navigation of the air by means of engine power would be mostly confined to the construction of navigable balloons. As already noted, Walker's work is not over practical, and the foregoing extract includes the most practical part of it; the rest is a series of dissertations on bird flight, in which, evidently, the portrait painter's observations were far less thorough than those of da Vinci or Borelli. Taken on the whole, Walker was a man with a hobby; he devoted to it much time and thought, but it remained a hobby, nevertheless. His observations have proved useful enough to give him a place among the early students of flight, but a great drawback to his work is the lack of practical experiment, by means of which alone real advance could be made; for, as Cayley admitted, theory and practice are very widely separated in the study of aviation, and the whole history of flight is a matter of unexpected results arising from scarcely foreseen causes, together with experiment as patient as daring. IV. THE MIDDLE NINETEENTH CENTURY Both Cayley and Walker were theorists, though Cayley supported his theoretical work with enough of practice to show that he studied along right lines; a little after his time there came practical men who brought to being the first machine which actually flew by the application of power. Before their time, however, mention must be made of the work of George Pocock of Bristol, who, somewhere about 1840 invented what was described as a 'kite carriage,' a vehicle which carried a number of persons, and obtained its motive power from a large kite. It is on record that, in the year 1846 one of these carriages conveyed sixteen people from Bristol to London. Another device of Pocock's was what he called a 'buoyant sail,' which was in effect a man-lifting kite, and by means of which a passenger was actually raised 100 yards from the ground, while the inventor's son scaled a cliff 200 feet in height by means of one of these, 'buoyant sails.' This constitutes the first definitely recorded experiment in the use of man-lifting kites. A History of the Charvolant or Kite-carriage, published in London in 1851, states that 'an experiment of a bold and very novel character was made upon an extensive down, where a large wagon with a considerable load was drawn along, whilst this huge machine at the same time carried an observer aloft in the air, realising almost the romance of flying.' Experimenting, two years after the appearance of the 'kite-carriage,' on the helicopter principle, W. H. Phillips constructed a model machine which weighed two pounds; this was fitted with revolving fans, driven by the combustion of charcoal, nitre, and gypsum, producing steam which, discharging into the air, caused the fans to revolve. The inventor stated that 'all being arranged, the steam was up in a few seconds, when the whole apparatus spun around like any top, and mounted into the air faster than a bird; to what height it ascended I had no means of ascertaining; the distance travelled was across two fields, where, after a long search, I found the machine minus the wings, which had been torn off in contact with the ground.' This could hardly be described as successful flight, but it was an advance in the construction of machines on the helicopter principle, and it was the first steam-driven model of the type which actually flew. The invention, however, was not followed up. After Phillips, we come to the great figures of the middle nineteenth century, W. S. Henson and John Stringfellow. Cayley had shown, in 1809, how success might be attained by developing the idea of the plane surface so driven as to take advantage of the resistance offered by the air, and Henson, who as early as 1840 was experimenting with model gliders and light steam engines, evolved and patented an idea for something very nearly resembling the monoplane of the early twentieth century. His patent, No. 9478, of the year 1842 explains the principle of the machine as follows:-- In order that the description hereafter given be rendered clear, I will first shortly explain the principle on which the machine is constructed. If any light and flat or nearly flat article be projected or thrown edgewise in a slightly inclined position, the same will rise on the air till the force exerted is expended, when the article so thrown or projected will descend; and it will readily be conceived that, if the article so projected or thrown possessed in itself a continuous power or force equal to that used in throwing or projecting it, the article would continue to ascend so long as the forward part of the surface was upwards in respect to the hinder part, and that such article, when the power was stopped, or when the inclination was reversed, would descend by gravity aided by the force of the power contained in the article, if the power be continued, thus imitating the flight of a bird. Now, the first part of my invention consists of an apparatus so constructed as to offer a very extended surface or plane of a light yet strong construction, which will have the same relation to the general machine which the extended wings of a bird have to the body when a bird is skimming in the air; but in place of the movement or power for onward progress being obtained by movement of the extended surface or plane, as is the case with the wings of birds, I apply suitable paddle-wheels or other proper mechanical propellers worked by a steam or other sufficiently light engine, and thus obtain the requisite power for onward movement to the plane or extended surface; and in order to give control as to the upward and downward direction of such a machine I apply a tail to the extended surface which is capable of being inclined or raised, so that when the power is acting to propel the machine, by inclining the tail upwards, the resistance offered by the air will cause the machine to rise on the air; and, on the contrary, when the inclination of the tail is reversed, the machine will immediately be propelled downwards, and pass through a plane more or less inclined to the horizon as the inclination of the tail is greater or less; and in order to guide the machine as to the lateral direction which it shall take, I apply a vertical rudder or second tail, and, according as the same is inclined in one direction or the other, so will be the direction of the machine.' The machine in question was very large, and differed very little from the modern monoplane; the materials were to be spars of bamboo and hollow wood, with diagonal wire bracing. The surface of the planes was to amount to 4,500 square feet, and the tail, triangular in form (here modern practice diverges) was to be 1,500 square feet. The inventor estimated that there would be a sustaining power of half a pound per square foot, and the driving power was to be supplied by a steam engine of 25 to 30 horse-power, driving two six-bladed propellers. Henson was largely dependent on Stringfellow for many details of his design, more especially with regard to the construction of the engine. The publication of the patent attracted a great amount of public attention, and the illustrations in contemporary journals, representing the machine flying over the pyramids and the Channel, anticipated fact by sixty years and more; the scientific world was divided, as it was up to the actual accomplishment of flight, as to the value of the invention. Strongfellow and Henson became associated after the conception of their design, with an attorney named Colombine, and a Mr Marriott, and between the four of them a project grew for putting the whole thing on a commercial basis--Henson and Stringfellow were to supply the idea; Marriott, knowing a member of Parliament, would be useful in getting a company incorporated, and Colombine would look after the purely legal side of the business. Thus an application was made by Mr Roebuck, Marriott's M.P., for an act of incorporation for 'The Aerial Steam Transit Company,' Roebuck moving to bring in the bill on the 24th of March, 1843. The prospectus, calling for funds for the development of the invention, makes interesting reading at this stage of aeronautical development; it was as follows: PROPOSAL. For subscriptions of sums of L100, in furtherance of an Extraordinary Invention not at present safe to be developed by securing the necessary Patents, for which three times the sum advanced, namely, L300, is conditionally guaranteed for each subscription on February 1, 1844, in case of the anticipations being realised, with the option of the subscribers being shareholders for the large amount if so desired, but not otherwise. ---------An Invention has recently been discovered, which if ultimately successful will be without parallel even in the age which introduced to the world the wonderful effects of gas and of steam. The discovery is of that peculiar nature, so simple in principle yet so perfect in all the ingredients required for complete and permanent success, that to promulgate it at present would wholly defeat its development by the immense competition which would ensue, and the views of the originator be entirely frustrated. This work, the result of years of labour and study, presents a wonderful instance of the adaptation of laws long since proved to the scientific world combined with established principles so judiciously and carefully arranged, as to produce a discovery perfect in all its parts and alike in harmony with the laws of Nature and of science. The Invention has been subjected to several tests and examinations and the results are most satisfactory so much so that nothing but the completion of the undertaking is required to determine its practical operation, which being once established its utility is undoubted, as it would be a necessary possession of every empire, and it were hardly too much to say, of every individual of competent means in the civilised world. Its qualities and capabilities are so vast that it were impossible and, even if possible, unsafe to develop them further, but some idea may be formed from the fact that as a preliminary measure patents in Great Britain Ireland, Scotland, the Colonies, France, Belgium, and the United States, and every other country where protection to the first discoveries of an Invention is granted, will of necessity be immediately obtained, and by the time these are perfected, which it is estimated will be in the month of February, the Invention will be fit for Public Trial, but until the Patents are sealed any further disclosure would be most dangerous to the principle on which it is based. Under these circumstances, it is proposed to raise an immediate sum of L2,000 in furtherance of the Projector's views, and as some protection to the parties who may embark in the matter, that this is not a visionary plan for objects imperfectly considered, Mr Colombine, to whom the secret has been confided, has allowed his name to be used on the occasion, and who will if referred to corroborate this statement, and convince any inquirer of the reasonable prospects of large pecuniary results following the development of the Invention. It is, therefore, intended to raise the sum of L2,000 in twenty sums of L100 each (of which any subscriber may take one or more not exceeding five in number to be held by any individual) the amount of which is to be paid into the hands of Mr Colombine as General Manager of the concern to be by him appropriated in procuring the several Patents and providing the expenses incidental to the works in progress. For each of which sums of L100 it is intended and agreed that twelve months after the 1st February next, the several parties subscribing shall receive as an equivalent for the risk to be run the sum of L300 for each of the sums of L100 now subscribed, provided when the time arrives the Patents shall be found to answer the purposes intended. As full and complete success is alone looked to, no moderate or imperfect benefit is to be anticipated, but the work, if it once passes the necessary ordeal, to which inventions of every kind must be first subject, will then be regarded by every one as the most astonishing discovery of modern times; no half success can follow, and therefore the full nature of the risk is immediately ascertained. The intention is to work and prove the Patent by collective instead of individual aid as less hazardous at first end more advantageous in the result for the Inventor, as well as others, by having the interest of several engaged in aiding one common object--the development of a Great Plan. The failure is not feared, yet as perfect success might, by possibility, not ensue, it is necessary to provide for that result, and the parties concerned make it a condition that no return of the subscribed money shall be required, if the Patents shall by any unforeseen circumstances not be capable of being worked at all; against which, the first application of the money subscribed, that of securing the Patents, affords a reasonable security, as no one without solid grounds would think of such an expenditure. It is perfectly needless to state that no risk or responsibility of any kind can arise beyond the payment of the sum to be subscribed under any circumstances whatever. As soon as the Patents shall be perfected and proved it is contemplated, so far as may be found practicable, to further the great object in view a Company shall be formed but respecting which it is unnecessary to state further details, than that a preference will be given to all those persons who now subscribe, and to whom shares shall be appropriated according to the larger amount (being three times the sum to be paid by each person) contemplated to be returned as soon as the success of the Invention shall have been established, at their option, or the money paid, whereby the Subscriber will have the means of either withdrawing with a large pecuniary benefit, or by continuing his interest in the concern lay the foundation for participating in the immense benefit which must follow the success of the plan. It is not pretended to conceal that the project is a speculation--all parties believe that perfect success, and thence incalculable advantage of every kind, will follow to every individual joining in this great undertaking; but the Gentlemen engaged in it wish that no concealment of the consequences, perfect success, or possible failure, should in the slightest degree be inferred. They believe this will prove the germ of a mighty work, and in that belief call for the operation of others with no visionary object, but a legitimate one before them, to attain that point where perfect success will be secured from their combined exertions. All applications to be made to D. E. Colombine, Esquire, 8 Carlton Chambers, Regent Street. The applications did not materialise, as was only to be expected in view of the vagueness of the proposals. Colombine did some advertising, and Mr Roebuck expressed himself as unwilling to proceed further in the venture. Henson experimented with models to a certain extent, while Stringfellow looked for funds for the construction of a full-sized monoplane. In November of 1843 he suggested that he and Henson should construct a large model out of their own funds. On Henson's suggestion Colombine and Marriott were bought out as regards the original patent, and Stringfellow and Henson entered into an agreement and set to work. Their work is briefly described in a little pamphlet by F. J. Stringfellow, entitled A few Remarks on what has been done with screw-propelled Aero-plane Machines from 1809 to 1892. The author writes with regard to the work that his father and Henson undertook:-- 'They commenced the construction of a small model operated by a spring, and laid down the larger model 20 ft. from tip to tip of planes, 3 1/2 ft. wide, giving 70 ft. of sustaining surface, about 10 more in the tail. The making of this model required great consideration; various supports for the wings were tried, so as to combine lightness with firmness, strength and rigidity. 'The planes were staid from three sets of fish-shaped masts, and rigged square and firm by flat steel rigging. The engine and boiler were put in the car to drive two screw-propellers, right and left-handed, 3 ft. in diameter, with four blades each, occupying three-quarters of the area of the circumference, set at an angle of 60 degrees. A considerable time was spent in perfecting the motive power. Compressed air was tried and abandoned. Tappets, cams, and eccentrics were all tried, to work the slide valve, to obtain the best results. The piston rod of engine passed through both ends of the cylinder, and with long connecting rods worked direct on the crank of the propellers. From memorandum of experiments still preserved the following is a copy of one: June, 27th, 1845, water 50 ozs., spirit 10 ozs., lamp lit 8.45, gauge moves 8.46, engine started 8.48 (100 lb. pressure), engine stopped 8.57, worked 9 minutes, 2,288 revolutions, average 254 per minute. No priming, 40 ozs. water consumed, propulsion (thrust of propellers), 5 lbs. 4 1/2 ozs. at commencement, steady, 4 lbs. 1/2 oz., 57 revolutions to 1 oz. water, steam cut off one-third from beginning. 'The diameter of cylinder of engine was 1 1/2 inch, length of stroke 3 inches. 'In the meantime an engine was also made for the smaller model, and a wing action tried, but with poor results. The time was mostly devoted to the larger model, and in 1847 a tent was erected on Bala Down, about two miles from Chard, and the model taken up one night by the workmen. The experiments were not so favourable as was expected. The machine could not support itself for any distance, but, when launched off, gradually descended, although the power and surface should have been ample; indeed, according to latest calculations, the thrust should have carried more than three times the weight, for there was a thrust of 5 lbs. from the propellers, and a surface of over 70 square feet to sustain under 30 lbs., but necessary speed was lacking.' Stringfellow himself explained the failure as follows:-- 'There stood our aerial protegee in all her purity--too delicate, too fragile, too beautiful for this rough world; at least those were my ideas at the time, but little did I think how soon it was to be realised. I soon found, before I had time to introduce the spark, a drooping in the wings, a flagging in all the parts. In less than ten minutes the machine was saturated with wet from a deposit of dew, so that anything like a trial was impossible by night. I did not consider we could get the silk tight and rigid enough. Indeed, the framework altogether was too weak. The steam-engine was the best part. Our want of success was not for want of power or sustaining surface, but for want of proper adaptation of the means to the end of the various parts.' Henson, who had spent a considerable amount of money in these experimental constructions, consoled himself for failure by venturing into matrimony; in 1849 he went to America, leaving Stringfellow to continue experimenting alone. From 1846 to 1848 Stringfellow worked on what is really an epoch-making item in the history of aeronautics--the first engine-driven aeroplane which actually flew. The machine in question had a 10 foot span, and was 2 ft. across in the widest part of the wing; the length of tail was 3 ft. 6 ins., and the span of tail in the widest part 22 ins., the total sustaining area being about 14 sq. ft. The motive power consisted of an engine with a cylinder of three-quarter inch diameter and a two-inch stroke; between this and the crank shaft was a bevelled gear giving three revolutions of the propellers to every stroke of the engine; the propellers, right and left screw, were four-bladed and 16 inches in diameter. The total weight of the model with engine was 8 lbs. Its successful flight is ascribed to the fact that Stringfellow curved the wings, giving them rigid front edges and flexible trailing edges, as suggested long before both by Da Vinci and Borelli, but never before put into practice. Mr F. J. Stringfellow, in the pamphlet quoted above, gives the best account of the flight of this model: 'My father had constructed another small model which was finished early in 1848, and having the loan of a long room in a disused lace factory, early in June the small model was moved there for experiments. The room was about 22 yards long and from 10 to 12 ft. high.... The inclined wire for starting the machine occupied less than half the length of the room and left space at the end for the machine to clear the floor. In the first experiment the tail was set at too high an angle, and the machine rose too rapidly on leaving the wire. After going a few yards it slid back as if coming down an inclined plane, at such an angle that the point of the tail struck the ground and was broken. The tail was repaired and set at a smaller angle. The steam was again got up, and the machine started down the wire, and, upon reaching the point of self-detachment, it gradually rose until it reached the farther end of the room, striking a hole in the canvas placed to stop it. In experiments the machine flew well, when rising as much as one in seven. The late Rev. J. Riste, Esq., lace manufacturer, Northcote Spicer, Esq., J. Toms, Esq., and others witnessed experiments. Mr Marriatt, late of the San Francisco News Letter brought down from London Mr Ellis, the then lessee of Cremorne Gardens, Mr Partridge, and Lieutenant Gale, the aeronaut, to witness experiments. Mr Ellis offered to construct a covered way at Cremorne for experiments. Mr Stringfellow repaired to Cremorne, but not much better accommodations than he had at home were provided, owing to unfulfilled engagement as to room. Mr Stringfellow was preparing for departure when a party of gentlemen unconnected with the Gardens begged to see an experiment, and finding them able to appreciate his endeavours, he got up steam and started the model down the wire. When it arrived at the spot where it should leave the wire it appeared to meet with some obstruction, and threatened to come to the ground, but it soon recovered itself and darted off in as fair a flight as it was possible to make at a distance of about 40 yards, where it was stopped by the canvas. 'Having now demonstrated the practicability of making a steam-engine fly, and finding nothing but a pecuniary loss and little honour, this experimenter rested for a long time, satisfied with what he had effected. The subject, however, had to him special charms, and he still contemplated the renewal of his experiments.' It appears that Stringfellow's interest did not revive sufficiently for the continuance of the experiments until the founding of the Aeronautical Society of Great Britain in 1866. Wenham's paper on Aerial Locomotion read at the first meeting of the Society, which was held at the Society of Arts under the Presidency of the Duke of Argyll, was the means of bringing Stringfellow back into the field. It was Wenham's suggestion, in the first place, that monoplane design should be abandoned for the superposition of planes; acting on this suggestion Stringfellow constructed a model triplane, and also designed a steam engine of slightly over one horse-power, and a one horse-power copper boiler and fire box which, although capable of sustaining a pressure of 500 lbs. to the square inch, weighed only about 40 lbs. Both the engine and the triplane model were exhibited at the first Aeronautical Exhibition held at the Crystal Palace in 1868. The triplane had a supporting surface of 28 sq. ft.; inclusive of engine, boiler, fuel, and water its total weight was under 12 lbs. The engine worked two 21 in. propellers at 600 revolutions per minute, and developed 100 lbs. steam pressure in five minutes, yielding one-third horse-power. Since no free flight was allowed in the Exhibition, owing to danger from fire, the triplane was suspended from a wire in the nave of the building, and it was noted that, when running along the wire, the model made a perceptible lift. A prize of L100 was awarded to the steam engine as the lightest steam engine in proportion to its power. The engine and model together may be reckoned as Stringfellow's best achievement. He used his L100 in preparation for further experiments, but he was now an old man, and his work was practically done. Both the triplane and the engine were eventually bought for the Washington Museum; Stringfellow's earlier models, together with those constructed by him in conjunction with Henson, remain in this country in the Victoria and Albert Museum. John Stringfellow died on December 13th, 1883. His place in the history of aeronautics is at least equal to that of Cayley, and it may be said that he laid the foundation of such work as was subsequently accomplished by Maxim, Langley, and their fellows. It was the coming of the internal combustion engine that rendered flight practicable, and had this prime mover been available in John Stringfellow's day the Wright brothers' achievement might have been antedated by half a century. V. WENHAM, LE BRIS, AND SOME OTHERS There are few outstanding events in the development of aeronautics between Stringfellow's final achievement and the work of such men as Lilienthal, Pilcher, Montgomery, and their kind; in spite of this, the later middle decades of the nineteenth century witnessed a considerable amount of spade work both in England and in France, the two countries which led in the way in aeronautical development until Lilienthal gave honour to Germany, and Langley and Montgomery paved the way for the Wright Brothers in America. Two abortive attempts characterised the sixties of last century in France. As regards the first of these, it was carried out by three men, Nadar, Ponton d'Amecourt, and De la Landelle, who conceived the idea of a full-sized helicopter machine. D'Amecourt exhibited a steam model, constructed in 1865, at the Aeronautical Society's Exhibition in 1868. The engine was aluminium with cylinders of bronze, driving two screws placed one above the other and rotating in Opposite directions, but the power was not sufficient to lift the model. De la Landelle's principal achievement consisted in the publication in 1863 of a book entitled Aviation which has a certain historical value; he got out several designs for large machines on the helicopter principle, but did little more until the three combined in the attempt to raise funds for the construction of their full-sized machine. Since the funds were not forthcoming, Nadar took to ballooning as the means of raising money; apparently he found this substitute for real flight sufficiently interesting to divert him from the study of the helicopter principle, for the experiment went no further. The other experimenter of this period, one Count d'Esterno, took out a patent in 1864 for a soaring machine which allowed for alteration of the angle of incidence of the wings in the manner that was subsequently carried out by the Wright Brothers. It was not until 1883 that any attempt was made to put this patent to practical use, and, as the inventor died while it was under construction, it was never completed. D'Esterno was also responsible for the production of a work entitled Du Vol des Oiseaux, which is a very remarkable study of the flight of birds. Mention has already been made of the founding of the Aeronautical Society of Great Britain, which, since 1918 has been the Royal Aeronautical Society. 1866 witnessed the first meeting of the Society under the Presidency of the Duke of Argyll, when in June, at the Society of Arts, Francis Herbert Wenham read his now classic paper Aerial Locomotion. Certain quotations from this will show how clearly Wenham had thought out the problems connected with flight. 'The first subject for consideration is the proportion of surface to weight, and their combined effect in descending perpendicularly through the atmosphere. The datum is here based upon the consideration of safety, for it may sometimes be needful for a living being to drop passively, without muscular effort. One square foot of sustaining surface for every pound of the total weight will be sufficient for security. 'According to Smeaton's table of atmospheric resistances, to produce a force of one pound on a square foot, the wind must move against the plane (or which is the same thing, the plane against the wind), at the rate of twenty-two feet per second, or 1,320 feet per minute, equal to fifteen miles per hour. The resistance of the air will now balance the weight on the descending surface, and, consequently, it cannot exceed that speed. Now, twenty-two feet per second is the velocity acquired at the end of a fall of eight feet--a height from which a well-knit man or animal may leap down without much risk of injury. Therefore, if a man with parachute weigh together 143 lbs., spreading the same number of square feet of surface contained in a circle fourteen and a half feet in diameter, he will descend at perhaps an unpleasant velocity, but with safety to life and limb. 'It is a remarkable fact how this proportion of wing-surface to weight extends throughout a great variety of the flying portion of the animal kingdom, even down to hornets, bees, and other insects. In some instances, however, as in the gallinaceous tribe, including pheasants, this area is somewhat exceeded, but they are known to be very poor fliers. Residing as they do chiefly on the ground, their wings are only required for short distances, or for raising them or easing their descent from their roosting-places in forest trees, the shortness of their wings preventing them from taking extended flights. The wing-surface of the common swallow is rather more than in the ratio of two square feet per pound, but having also great length of pinion, it is both swift and enduring in its flight. When on a rapid course this bird is in the habit of furling its wings into a narrow compass. The greater extent of surface is probably needful for the continual variations of speed and instant stoppages for obtaining its insect food. 'On the other hand, there are some birds, particularly of the duck tribe, whose wing-surface but little exceeds half a square foot, or seventy-two inches per pound, yet they may be classed among the strongest and swiftest of fliers. A weight of one pound, suspended from an area of this extent, would acquire a velocity due to a fall of sixteen feet--a height sufficient for the destruction or injury of most animals. But when the plane is urged forward horizontally, in a manner analogous to the wings of a bird during flight, the sustaining power is greatly influenced by the form and arrangement of the surface. 'In the case of perpendicular descent, as a parachute, the sustaining effect will be much the same, whatever the figure of the outline of the superficies may be, and a circle perhaps affords the best resistance of any. Take, for example, a circle of twenty square feet (as possessed by the pelican) loaded with as many pounds. This, as just stated, will limit the rate of perpendicular descent to 1,320 feet per minute. But instead of a circle sixty-one inches in diameter, if the area is bounded by a parallelogram ten feet long by two feet broad, and whilst at perfect freedom to descend perpendicularly, let a force be applied exactly in a horizontal direction, so as to carry it edgeways, with the long side foremost, at a forward speed of thirty miles per hour--just double that of its passive descent: the rate of fall under these conditions will be decreased most remarkably, probably to less than one-fifteenth part, or eighty-eight feet per minute, or one mile per hour.' And again: 'It has before been shown how utterly inadequate the mere perpendicular impulse of a plane is found to be in supporting a weight, when there is no horizontal motion at the time. There is no material weight of air to be acted upon, and it yields to the slightest force, however great the velocity of impulse may be. On the other hand, suppose that a large bird, in full flight, can make forty miles per hour, or 3,520 feet per minute, and performs one stroke per second. Now, during every fractional portion of that stroke, the wing is acting upon and obtaining an impulse from a fresh and undisturbed body of air; and if the vibration of the wing is limited to an arc of two feet, this by no means represents the small force of action that would be obtained when in a stationary position, for the impulse is secured upon a stratum of fifty-eight feet in length of air at each stroke. So that the conditions of weight of air for obtaining support equally well apply to weight of air and its reaction in producing forward impulse. 'So necessary is the acquirement of this horizontal speed, even in commencing flight, that most heavy birds, when possible, rise against the wind, and even run at the top of their speed to make their wings available, as in the example of the eagle, mentioned at the commencement of this paper. It is stated that the Arabs, on horseback, can approach near enough to spear these birds, when on the plain, before they are able to rise; their habit is to perch on an eminence, where possible. 'The tail of a bird is not necessary for flight. A pigeon can fly perfectly with this appendage cut short off; it probably performs an important function in steering, for it is to be remarked, that most birds that have either to pursue or evade pursuit are amply provided with this organ. 'The foregoing reasoning is based upon facts, which tend to show that the flight of the largest and heaviest of all birds is really performed with but a small amount of force, and that man is endowed with sufficient muscular power to enable him also to take individual and extended flights, and that success is probably only involved in a question of suitable mechanical adaptations. But if the wings are to be modelled in imitation of natural examples, but very little consideration will serve to demonstrate its utter impracticability when applied in these forms.' Thus Wenham, one of the best theorists of his age. The Society with which this paper connects his name has done work, between that time and the present, of which the importance cannot be overestimated, and has been of the greatest value in the development of aeronautics, both in theory and experiment. The objects of the Society are to give a stronger impulse to the scientific study of aerial navigation, to promote the intercourse of those interested in the subject at home and abroad, and to give advice and instruction to those who study the principles upon which aeronautical science is based. From the date of its foundation the Society has given special study to dynamic flight, putting this before ballooning. Its library, its bureau of advice and information, and its meetings, all assist in forwarding the study of aeronautics, and its twenty-three early Annual Reports are of considerable value, containing as they do a large amount of useful information on aeronautical subjects, and forming practically the basis of aeronautical science. Ante to Wenham, Stringfellow and the French experimenters already noted, by some years, was Le Bris, a French sea captain, who appears to have required only a thorough scientific training to have rendered him of equal moment in the history of gliding flight with Lilienthal himself. Le Bris, it appears, watched the albatross and deduced, from the manner in which it supported itself in the air, that plane surfaces could be constructed and arranged to support a man in like manner. Octave Chanute, himself a leading exponent of gliding, gives the best description of Le Bris's experiments in a work, Progress in Flying Machines, which, although published as recently as I 1894, is already rare. Chanute draws from a still rarer book, namely, De la Landelle's work published in 1884. Le Bris himself, quoted by De la Landelle as speaking of his first visioning of human flight, describes how he killed an albatross, and then--'I took the wing of the albatross and exposed it to the breeze; and lo! in spite of me it drew forward into the wind; notwithstanding my resistance it tended to rise. Thus I had discovered the secret of the bird! I comprehended the whole mystery of flight.' This apparently took place while at sea; later on Le Bris, returning to France, designed and constructed an artificial albatross of sufficient size to bear his own weight. The fact that he followed the bird outline as closely as he did attests his lack of scientific training for his task, while at the same time the success of the experiment was proof of his genius. The body of his artificial bird, boat-shaped, was 13 1/2 ft. in length, with a breadth of 4 ft. at the widest part. The material was cloth stretched over a wooden framework; in front was a small mast rigged after the manner of a ship's masts to which were attached poles and cords with which Le Bris intended to work the wings. Each wing was 23 ft. in length, giving a total supporting surface of nearly 220 sq. ft.; the weight of the whole apparatus was only 92 pounds. For steering, both vertical and horizontal, a hinged tail was provided, and the leading edge of each wing was made flexible. In construction throughout, and especially in that of the wings, Le Bris adhered as closely as possible to the original albatross. He designed an ingenious kind of mechanism which he termed 'Rotules,' which by means of two levers gave a rotary motion to the front edge of the wings, and also permitted of their adjustment to various angles. The inventor's idea was to stand upright in the body of the contrivance, working the levers and cords with his hands, and with his feet on a pedal by means of which the steering tail was to be worked. He anticipated that, given a strong wind, he could rise into the air after the manner of an albatross, without any need for flapping his wings, and the account of his first experiment forms one of the most interesting incidents in the history of flight. It is related in full in Chanute's work, from which the present account is summarised. Le Bris made his first experiment on a main road near Douarnenez, at Trefeuntec. From his observation of the albatross Le Bris concluded that it was necessary to get some initial velocity in order to make the machine rise; consequently on a Sunday morning, with a breeze of about 12 miles an hour blowing down the road, he had his albatross placed on a cart and set off, with a peasant driver, against the wind. At the outset the machine was fastened to the cart by a rope running through the rails on which the machine rested, and secured by a slip knot on Le Bris's own wrist, so that only a jerk on his part was necessary to loosen the rope and set the machine free. On each side walked an assistant holding the wings, and when a turn of the road brought the machine full into the wind these men were instructed to let go, while the driver increased the pace from a walk to a trot. Le Bris, by pressure on the levers of the machine, raised the front edges of his wings slightly; they took the wind almost instantly to such an extent that the horse, relieved of a great part of the weight he had been drawing, turned his trot into a gallop. Le Bris gave the jerk of the rope that should have unfastened the slip knot, but a concealed nail on the cart caught the rope, so that it failed to run. The lift of the machine was such, however, that it relieved the horse of very nearly the weight of the cart and driver, as well as that of Le Bris and his machine, and in the end the rails of the cart gave way. Le Bris rose in the air, the machine maintaining perfect balance and rising to a height of nearly 300 ft., the total length of the glide being upwards of an eighth of a mile. But at the last moment the rope which had originally fastened the machine to the cart got wound round the driver's body, so that this unfortunate dangled in the air under Le Bris and probably assisted in maintaining the balance of the artificial albatross. Le Bris, congratulating himself on his success, was prepared to enjoy just as long a time in the air as the pressure of the wind would permit, but the howls of the unfortunate driver at the end of the rope beneath him dispelled his dreams; by working his levers he altered the angle of the front wing edges so skilfully as to make a very successful landing indeed for the driver, who, entirely uninjured, disentangled himself from the rope as soon as he touched the ground, and ran off to retrieve his horse and cart. Apparently his release made a difference in the centre of gravity, for Le Bris could not manipulate his levers for further ascent; by skilful manipulation he retarded the descent sufficiently to escape injury to himself; the machine descended at an angle, so that one wing, striking the ground in front of the other, received a certain amount of damage. It may have been on account of the reluctance of this same or another driver that Le Bris chose a different method of launching himself in making a second experiment with his albatross. He chose the edge of a quarry which had been excavated in a depression of the ground; here he assembled his apparatus at the bottom of the quarry, and by means of a rope was hoisted to a height of nearly 100 ft. from the quarry bottom, this rope being attached to a mast which he had erected upon the edge of the depression in which the quarry was situated. Thus hoisted, the albatross was swung to face a strong breeze that blew inland, and Le Bris manipulated his levers to give the front edges of his wings a downward angle, so that only the top surfaces should take the wing pressure. Having got his balance, he obtained a lifting angle of incidence on the wings by means of his levers, and released the hook that secured the machine, gliding off over the quarry. On the glide he met with the inevitable upward current of air that the quarry and the depression in which it was situated caused; this current upset the balance of the machine and flung it to the bottom of the quarry, breaking it to fragments. Le Bris, apparently as intrepid as ingenious, gripped the mast from which his levers were worked, and, springing upward as the machine touched earth, escaped with no more damage than a broken leg. But for the rebound of the levers he would have escaped even this. The interest of these experiments is enhanced by the fact that Le Bris was a seafaring man who conducted them from love of the science which had fired his imagination, and in so doing exhausted his own small means. It was in 1855 that he made these initial attempts, and twelve years passed before his persistence was rewarded by a public subscription made at Brest for the purpose of enabling him to continue his experiments. He built a second albatross, and on the advice of his friends ballasted it for flight instead of travelling in it himself. It was not so successful as the first, probably owing to the lack of human control while in flight; on one of the trials a height of 150 ft. was attained, the glider being secured by a thin rope and held so as to face into the wind. A glide of nearly an eighth of a mile was made with the rope hanging slack, and, at the end of this distance, a rise in the ground modified the force of the wind, whereupon the machine settled down without damage. A further trial in a gusty wind resulted in the complete destruction of this second machine; Le Bris had no more funds, no further subscriptions were likely to materialise, and so the experiments of this first exponent of the art of gliding (save for Besnier and his kind) came to an end. They constituted a notable achievement, and undoubtedly Le Bris deserves a better place than has been accorded him in the ranks of the early experimenters. Contemporary with him was Charles Spencer, the first man to practice gliding in England. His apparatus consisted of a pair of wings with a total area of 30 sq. ft., to which a tail and body were attached. The weight of this apparatus was some 24 lbs., and, launching himself on it from a small eminence, as was done later by Lilienthal in his experiments, the inventor made flights of over 120 feet. The glider in question was exhibited at the Aeronautical Exhibition of 1868. VI. THE AGE OF THE GIANTS Until the Wright Brothers definitely solved the problem of flight and virtually gave the aeroplane its present place in aeronautics, there were three definite schools of experiment. The first of these was that which sought to imitate nature by means of the ornithopter or flapping-wing machines directly imitative of bird flight; the second school was that which believed in the helicopter or lifting screw; the third and eventually successful school is that which followed up the principle enunciated by Cayley, that of opposing a plane surface to the resistance of the air by supplying suitable motive power to drive it at the requisite angle for support. Engineering problems generally go to prove that too close an imitation of nature in her forms of recipro-cating motion is not advantageous; it is impossible to copy the minutiae of a bird's wing effectively, and the bird in flight depends on the tiniest details of its feathers just as much as on the general principle on which the whole wing is constructed. Bird flight, however, has attracted many experimenters, including even Lilienthal; among others may be mentioned F. W. Brearey, who invented what he called the 'Pectoral cord,' which stored energy on each upstroke of the artificial wing; E. P. Frost; Major R. Moore, and especially Hureau de Villeneuve, a most enthusiastic student of this form of flight, who began his experiments about 1865, and altogether designed and made nearly 300 artificial birds, one of his later constructions was a machine in bird form with a wing span of about 50 ft.; the motive power for this was supplied by steam from a boiler which, being stationary on the ground, was connected by a length of hose to the machine. De Villeneuve, turning on steam for his first trial, obtained sufficient power to make the wings beat very forcibly; with the inventor on the machine the latter rose several feet into the air, whereupon de Villeneuve grew nervous and turned off the steam supply. The machine fell to the earth, breaking one of its wings, and it does not appear that de Villeneuve troubled to reconstruct it. This experiment remains as the greatest success yet achieved by any machine constructed on the ornithopter principle. It may be that, as forecasted by the prophet Wells, the flapping-wing machine will yet come to its own and compete with the aeroplane in efficiency. Against this, however, are the practical advantages of the rotary mechanism of the aeroplane propeller as compared with the movement of a bird's wing, which, according to Marey, moves in a figure of eight. The force derived from a propeller is of necessity continual, while it is equally obvious that that derived from a flapping movement is intermittent, and, in the recovery of a wing after completion of one stroke for the next, there is necessarily a certain cessation, if not loss, of power. The matter of experiment along any lines in connection with aviation is primarily one of hard cash. Throughout the whole history of flight up to the outbreak of the European war development has been handicapped on the score of finance, and, since the arrival of the aeroplane, both ornithopter and helicopter schools have been handicapped by this consideration. Thus serious study of the efficiency of wings in imitation of those of the living bird has not been carried to a point that might win success for this method of propulsion. Even Wilbur Wright studied this subject and propounded certain theories, while a later and possibly more scientific student, F. W. Lanchester, has also contributed empirical conclusions. Another and earlier student was Lawrence Hargrave, who made a wing-propelled model which achieved successful flight, and in 1885 was exhibited before the Royal Society of New South Wales. Hargrave called the principle on which his propeller worked that of a 'Trochoided plane'; it was, in effect, similar to the feathering of an oar. Hargrave, to diverge for a brief while from the machine to the man, was one who, although he achieved nothing worthy of special remark, contributed a great deal of painstaking work to the science of flight. He made a series of experiments with man-lifting kites in addition to making a study of flapping-wing flight. It cannot be said that he set forth any new principle; his work was mainly imitative, but at the same time by developing ideas originated in great measure by others he helped toward the solution of the problem. Attempts at flight on the helicopter principle consist in the work of De la Landelle and others already mentioned. The possibility of flight by this method is modified by a very definite disadvantage of which lovers of the helicopter seem to take little account. It is always claimed for a machine of this type that it possesses great advantages both in rising and in landing, since, if it were effective, it would obviously be able to rise from and alight on any ground capable of containing its own bulk; a further advantage claimed is that the helicopter would be able to remain stationary in the air, maintaining itself in any position by the vertical lift of its propeller. These potential assets do not take into consideration the fact that efficiency is required not only in rising, landing, and remaining stationary in the air, but also in actual flight. It must be evident that if a certain amount of the motive force is used in maintaining the machine off the ground, that amount of force is missing from the total of horizontal driving power. Again, it is often assumed by advocates of this form of flight that the rapidity of climb of the helicopter would be far greater than that of the driven plane; this view overlooks the fact that the maintenance of aerodynamic support would claim the greater part of the engine-power; the rate of ascent would be governed by the amount of power that could be developed surplus to that required for maintenance. This is best explained by actual figures: assuming that a propeller 15 ft. in diameter is used, almost 50 horse-power would be required to get an upward lift of 1,000 pounds; this amount of horse-power would be continually absorbed in maintaining the machine in the air at any given level; for actual lift from one level to another at a speed of eleven feet per second a further 20 horse-power would be required, which means that 70 horse-power must be constantly provided for; this absorption of power in the mere maintenance of aero-dynamic support is a permanent drawback. The attraction of the helicopter lies, probably, in the ease with which flight is demonstrated by means of models constructed on this principle, but one truism with regard to the principles of flight is that the problems change remarkably, and often unexpectedly, with the size of the machine constructed for experiment. Berriman, in a brief but very interesting manual entitled Principles of Flight, assumed that 'there is a significant dimension of which the effective area is an expression of the second power, while the weight became an expression of the third power. Then once again we have the two-thirds power law militating against the successful construction of large helicopters, on the ground that the essential weight increases disproportionately fast to the effective area. From a consideration of the structural features of propellers it is evident that this particular relationship does not apply in practice, but it seems reasonable that some such governing factor should exist as an explanation of the apparent failure of all full-sized machines that have been constructed. Among models there is nothing more strikingly successful than the toy helicopter, in which the essential weight is so small compared with the effective area.' De la Landelle's work, already mentioned, was carried on a few years later by another Frenchman, Castel, who constructed a machine with eight propellers arranged in two fours and driven by a compressed air motor or engine. The model with which Castel experimented had a total weight of only 49 lbs.; it rose in the air and smashed itself by driving against a wall, and the inventor does not seem to have proceeded further. Contemporary with Castel was Professor Forlanini, whose design was for a machine very similar to de la Landelle's, with two superposed screws. This machine ranks as the second on the helicopter principle to achieve flight; it remained in the air for no less than the third of a minute in one of its trials. Later experimenters in this direction were Kress, a German; Professor Wellner, an Austrian; and W. R. Kimball, an American. Kress, like most Germans, set to the development of an idea which others had originated; he followed de la Landelle and Forlanini by fitting two superposed propellers revolving in opposite directions, and with this machine he achieved good results as regards horse-power to weight; Kimball, it appears, did not get beyond the rubber-driven model stage, and any success he may have achieved was modified by the theory enunciated by Berriman and quoted above. Comparing these two schools of thought, the helicopter and bird-flight schools, it appears that the latter has the greater chance of eventual success--that is, if either should ever come into competition with the aeroplane as effective means of flight. So far, the aeroplane holds the field, but the whole science of flight is so new and so full of unexpected developments that this is no reason for assuming that other means may not give equal effect, when money and brains are diverted from the driven plane to a closer imitation of natural flight. Reverting from non-success to success, from consideration of the two methods mentioned above to the direction in which practical flight has been achieved, it is to be noted that between the time of Le Bris, Stringfellow, and their contemporaries, and the nineties of last century, there was much plodding work carried out with little visible result, more especially so far as English students were concerned. Among the incidents of those years is one of the most pathetic tragedies in the whole history of aviation, that of Alphonse Penaud, who, in his thirty years of life, condensed the experience of his predecessors and combined it with his own genius to state in a published patent what the aeroplane of to-day should be. Consider the following abstract of Penaud's design as published in his patent of 1876, and comparison of this with the aeroplane that now exists will show very few divergences except for those forced on the inventor by the fact that the internal combustion engine had not then developed. The double surfaced planes were to be built with wooden ribs and arranged with a slight dihedral angle; there was to be a large aspect ratio and the wings were cambered as in Stringfellow's later models. Provision was made for warping the wings while in flight, and the trailing edges were so designed as to be capable of upward twist while the machine was in the air. The planes were to be placed above the car, and provision was even made for a glass wind-screen to give protection to the pilot during flight. Steering was to be accomplished by means of lateral and vertical planes forming a tail; these controlled by a single lever corresponding to the 'joy stick' of the present day plane. Penaud conceived this machine as driven by two propellers; alternatively these could be driven by petrol or steam-fed motor, and the centre of gravity of the machine while in flight was in the front fifth of the wings. Penaud estimated from 20 to 30 horse-power sufficient to drive this machine, weighing with pilot and passenger 2,600 lbs., through the air at a speed of 60 miles an hour, with the wings set at an angle of incidence of two degrees. So complete was the design that it even included instruments, consisting of an aneroid, pressure indicator, an anemometer, a compass, and a level. There, with few alterations, is the aeroplane as we know it--and Penaud was twenty-seven when his patent was published. For three years longer he worked, experimenting with models, contributing essays and other valuable data to French papers on the subject of aeronautics. His gains were ill health, poverty, and neglect, and at the age of thirty a pistol shot put an end to what had promised to be one of the most brilliant careers in all the history of flight. Two years before the publication of Penaud's patent Thomas Moy experimented at the Crystal Palace with a twin-propelled aeroplane, steam driven, which seems to have failed mainly because the internal combustion engine had not yet come to give sufficient power for weight. Moy anchored his machine to a pole running on a prepared circular track; his engine weighed 80 lbs. and, developing only three horse-power, gave him a speed of 12 miles an hour. He himself estimated that the machine would not rise until he could get a speed of 35 miles an hour, and his estimate was correct. Two six-bladed propellers were placed side by side between the two main planes of the machine, which was supported on a triangular wheeled undercarriage and steered by fairly conventional tail planes. Moy realised that he could not get sufficient power to achieve flight, but he went on experimenting in various directions, and left much data concerning his experiments which has not yet been deemed worthy of publication, but which still contains a mass of information that is of practical utility, embodying as it does a vast amount of painstaking work. Penaud and Moy were followed by Goupil, a Frenchman, who, in place of attempting to fit a motor to an aeroplane, experimented by making the wind his motor. He anchored his machine to the ground, allowing it two feet of lift, and merely waited for a wind to come along and lift it. The machine was stream lined, and the wings, curving as in the early German patterns of war aeroplanes, gave a total lifting surface of about 290 sq. ft. Anchored to the ground and facing a wind of 19 feet per second, Goupil's machine lifted its own weight and that of two men as well to the limit of its anchorage. Although this took place as late as 1883 the inventor went no further in practical work. He published a book, however, entitled La Locomotion Aerienne, which is still of great importance, more especially on the subject of inherent stability. In 1884 came the first patents of Horatio Phillips, whose work lay mainly in the direction of investigation into the curvature of plane surfaces, with a view to obtaining the greatest amount of support. Phillips was one of the first to treat the problem of curvature of planes as a matter for scientific experiment, and, great as has been the development of the driven plane in the 36 years that have passed since he began, there is still room for investigation into the subject which he studied so persistently and with such valuable result. At this point it may be noted that, with the solitary exception of Le Bris, practically every student of flight had so far set about constructing the means of launching humanity into the air without any attempt at ascertaining the nature and peculiarities of the sustaining medium. The attitude of experimenters in general might be compared to that of a man who from boyhood had grown up away from open water, and, at the first sight of an expanse of water, set to work to construct a boat with a vague idea that, since wood would float, only sufficient power was required to make him an efficient navigator. Accident, perhaps, in the shape of lack of means of procuring driving power, drove Le Bris to the form of experiment which he actually carried out; it remained for the later years of the nineteenth century to produce men who were content to ascertain the nature of the support the air would afford before attempting to drive themselves through it. Of the age in which these men lived and worked, giving their all in many cases to the science they loved, even to life itself, it may be said with truth that 'there were giants on the earth in those days,' as far as aeronautics is in question. It was an age of giants who lived and dared and died, venturing into uncharted space, knowing nothing of its dangers, giving, as a man gives to his mistress, without stint and for the joy of the giving. The science of to-day, compared with the glimmerings that were in that age of the giants, is a fixed and certain thing; the problems of to-day are minor problems, for the great major problem vanished in solution when the Wright Brothers made their first ascent. In that age of the giants was evolved the flying man, the new type in human species which found full expression and came to full development in the days of the war, achieving feats of daring and endurance which leave the commonplace landsman staggered at thought of that of which his fellows prove themselves capable. He is a new type, this flying man, a being of self-forgetfulness; of such was Lilienthal, of such was Pilcher; of such in later days were Farman, Bleriot, Hamel, Rolls, and their fellows; great names that will live for as long as man flies, adventurers equally with those of the spacious days of Elizabeth. To each of these came the call, and he worked and dared and passed, having, perhaps, advanced one little step in the long march that has led toward the perfecting of flight. It is not yet twenty years since man first flew, but into that twenty years have been compressed a century or so of progress, while, in the two decades that preceded it, was compressed still more. We have only to recall and recount the work of four men: Lilienthal, Langley, Pilcher, and Clement Ader to see the immense stride that was made between the time when Penaud pulled a trigger for the last time and the Wright Brothers first left the earth. Into those two decades was compressed the investigation that meant knowledge of the qualities of the air, together with the development of the one prime mover that rendered flight a possibility--the internal combustion engine. The coming and progress of this latter is a thing apart, to be detailed separately; for the present we are concerned with the evolution of the driven plane, and with it the evolution of that daring being, the flying man. The two are inseparable, for the men gave themselves to their art; the story of Lilienthal's life and death is the story of his work; the story of Pilcher's work is that of his life and death. Considering the flying man as he appeared in the war period, there entered into his composition a new element--patriotism--which brought about a modification of the type, or, perhaps, made it appear that certain men belonged to the type who in reality were commonplace mortals, animated, under normal conditions, by normal motives, but driven by the stress of the time to take rank with the last expression of human energy, the flying type. However that may be, what may be termed the mathematising of aeronautics has rendered the type itself evanescent; your pilot of to-day knows his craft, once he is trained, much in the manner that a driver of a motor-lorry knows his vehicle; design has been systematised, capabilities have been tabulated; camber, dihedral angle, aspect ratio, engine power, and plane surface, are business items of drawing office and machine shop; there is room for enterprise, for genius, and for skill; once and again there is room for daring, as in the first Atlantic flight. Yet that again was a thing of mathematical calculation and petrol storage, allied to a certain stark courage which may be found even in landsmen. For the ventures into the unknown, the limit of daring, the work for work's sake, with the almost certainty that the final reward was death, we must look back to the age of the giants, the age when flying was not a business, but romance. VII. LILIENTHAL AND PILCHER There was never a more enthusiastic and consistent student of the problems of flight than Otto Lilienthal, who was born in 1848 at Anklam, Pomerania, and even from his early school-days dreamed and planned the conquest of the air. His practical experiments began when, at the age of thirteen, he and his brother Gustav made wings consisting of wooden framework covered with linen, which Otto attached to his arms, and then ran downhill flapping them. In consequence of possible derision on the part of other boys, Otto confined these experiments for the most part to moonlit nights, and gained from them some idea of the resistance offered by flat surfaces to the air. It was in 1867 that the two brothers began really practical work, experimenting with wings which, from their design, indicate some knowledge of Besnier and the history of his gliding experiments; these wings the brothers fastened to their backs, moving them with their legs after the fashion of one attempting to swim. Before they had achieved any real success in gliding the Franco-German war came as an interruption; both brothers served in this campaign, resuming their experiments in 1871 at the conclusion of hostilities. The experiments made by the brothers previous to the war had convinced Otto that previous experimenters in gliding flight had failed through reliance on empirical conclusions or else through incomplete observation on their own part, mostly of bird flight. From 1871 onward Otto Lilenthal (Gustav's interest in the problem was not maintained as was his brother's) made what is probably the most detailed and accurate series of observations that has ever been made with regard to the properties of curved wing surfaces. So far as could be done, Lilienthal tabulated the amount of air resistance offered to a bird's wing, ascertaining that the curve is necessary to flight, as offering far more resistance than a flat surface. Cayley, and others, had already stated this, but to Lilienthal belongs the honour of being first to put the statement to effective proof--he made over 2,000 gliding flights between 1891 and the regrettable end of his experiments; his practical conclusions are still regarded as part of the accepted theory of students of flight. In 1889 he published a work on the subject of gliding flight which stands as data for investigators, and, on the conclusions embodied in this work, he began to build his gliders and practice what he had preached, turning from experiment with models to wings that he could use. It was in the summer of 1891 that he built his first glider of rods of peeled willow, over which was stretched strong cotton fabric; with this, which had a supporting surface of about 100 square feet, Otto Lilienthal launched himself in the air from a spring board, making glides which, at first of only a few feet, gradually lengthened. As his experience of the supporting qualities of the air progressed he gradually altered his designs until, when Pilcher visited him in the spring of 1895, he experimented with a glider, roughly made of peeled willow rods and cotton fabric, having an area of 150 square feet and weighing half a hundredweight. By this time Lilienthal had moved from his springboard to a conical artificial hill which he had had thrown up on level ground at Grosse Lichterfelde, near Berlin. This hill was made with earth taken from the excavations incurred in constructing a canal, and had a cave inside in which Lilienthal stored his machines. Pilcher, in his paper on 'Gliding,' [*] gives an excellent short summary of Lilienthal's experiments, from which the following extracts are taken:-- [*] Aeronautical Classes, No. 5. Royal Aeronautical Society's publications. 'At first Lilienthal used to experiment by jumping off a springboard with a good run. Then he took to practicing on some hills close to Berlin. In the summer of 1892 he built a flat-roofed hut on the summit of a hill, from the top of which he used to jump, trying, of course, to soar as far as possible before landing.... One of the great dangers with a soaring machine is losing forward speed, inclining the machine too much down in front, and coming down head first. Lilienthal was the first to introduce the system of handling a machine in the air merely by moving his weight about in the machine; he always rested only on his elbows or on his elbows and shoulders.... 'In 1892 a canal was being cut, close to where Lilienthal lived, in the suburbs of Berlin, and with the surplus earth Lilienthal had a special hill thrown up to fly from. The country round is as flat as the sea, and there is not a house or tree near it to make the wind unsteady, so this was an ideal practicing ground; for practicing on natural hills is generally rendered very difficult by shifty and gusty winds.... This hill is 50 feet high, and conical. Inside the hill there is a cave for the machines to be kept in.... When Lilienthal made a good flight he used to land 300 feet from the centre of the hill, having come down at an angle of 1 in 6; but his best flights have been at an angle of about 1 in 10. 'If it is calm, one must run a few steps down the hill, holding the machine as far back on oneself as possible, when the air will gradually support one, and one slides off the hill into the air. If there is any wind, one should face it at starting; to try to start with a side wind is most unpleasant. It is possible after a great deal of practice to turn in the air, and fairly quickly. This is accomplished by throwing one's weight to one side, and thus lowering the machine on that side towards which one wants to turn. Birds do the same thing--crows and gulls show it very clearly. Last year Lilienthal chiefly experimented with double-surfaced machines. These were very much like the old machines with awnings spread above them. 'The object of making these double-surfaced machines was to get more surface without increasing the length and width of the machine. This, of course, it does, but I personally object to any machine in which the wing surface is high above the weight. I consider that it makes the machine very difficult to handle in bad weather, as a puff of wind striking the surface, high above one, has a great tendency to heel the machine over. 'Herr Lilienthal kindly allowed me to sail down his hill in one of these double-surfaced machines last June. With the great facility afforded by his conical hill the machine was handy enough; but I am afraid I should not be able to manage one at all in the squally districts I have had to practice in over here. 'Herr Lilienthal came to grief through deserting his old method of balancing. In order to control his tipping movements more rapidly he attached a line from his horizontal rudder to his head, so that when he moved his head forward it would lift the rudder and tip the machine up in front, and vice versa. He was practicing this on some natural hills outside Berlin, and he apparently got muddled with the two motions, and, in trying to regain speed after he had, through a lull in the wind, come to rest in the air, let the machine get too far down in front, came down head first and was killed.' Then in another passage Pilcher enunciates what is the true value of such experiments as Lilienthal--and, subsequently, he himself--made: 'The object of experimenting with soaring machines,' he says, 'is to enable one to have practice in starting and alighting and controlling a machine in the air. They cannot possibly float horizontally in the air for any length of time, but to keep going must necessarily lose in elevation. They are excellent schooling machines, and that is all they are meant to be, until power, in the shape of an engine working a screw propeller, or an engine working wings to drive the machine forward, is added; then a person who is used to soaring down a hill with a simple soaring machine will be able to fly with comparative safety. One can best compare them to bicycles having no cranks, but on which one could learn to balance by coming down an incline.' It was in 1895 that Lilienthal passed from experiment with the monoplane type of glider to the construction of a biplane glider which, according to his own account, gave better results than his previous machines. 'Six or seven metres velocity of wind,' he says, 'sufficed to enable the sailing surface of 18 square metres to carry me almost horizontally against the wind from the top of my hill without any starting jump. If the wind is stronger I allow myself to be simply lifted from the point of the hill and to sail slowly towards the wind. The direction of the flight has, with strong wind, a strong upwards tendency. I often reach positions in the air which are much higher than my starting point. At the climax of such a line of flight I sometimes come to a standstill for some time, so that I am enabled while floating to speak with the gentlemen who wish to photograph me, regarding the best position for the photographing.' Lilienthal's work did not end with simple gliding, though he did not live to achieve machine-driven flight. Having, as he considered, gained sufficient experience with gliders, he constructed a power-driven machine which weighed altogether about 90 lbs., and this was thoroughly tested. The extremities of its wings were made to flap, and the driving power was obtained from a cylinder of compressed carbonic acid gas, released through a hand-operated valve which, Lilienthal anticipated, would keep the machine in the air for four minutes. There were certain minor accidents to the mechanism, which delayed the trial flights, and on the day that Lilienthal had determined to make his trial he made a long gliding flight with a view to testing a new form of rudder that--as Pilcher relates--was worked by movements of his head. His death came about through the causes that Pilcher states; he fell from a height of 50 feet, breaking his spine, and the next day he died. It may be said that Lilienthal accomplished as much as any one of the great pioneers of flying. As brilliant in his conceptions as da Vinci had been in his, and as conscientious a worker as Borelli, he laid the foundations on which Pilcher, Chanute, and Professor Montgomery were able to build to such good purpose. His book on bird flight, published in 1889, with the authorship credited both to Otto and his brother Gustav, is regarded as epoch-making; his gliding experiments are no less entitled to this description. In England Lilienthal's work was carried on by Percy Sinclair Pilcher, who, born in 1866, completed six years' service in the British Navy by the time that he was nineteen, and then went through a course of engineering, subsequently joining Maxim in his experimental work. It was not until 1895 that he began to build the first of the series of gliders with which he earned his plane among the pioneers of flight. Probably the best account of Pilcher's work is that given in the Aeronautical Classics issued by the Royal Aeronautical Society, from which the following account of Pilcher's work is mainly abstracted.[*] [*] Aeronautical Classes, No. 5. Royal Aeronautical Society publications. The 'Bat,' as Pilcher named his first glider, was a monoplane which he completed before he paid his visit to Lilienthal in 1895. Concerning this Pilcher stated that he purposely finished his own machine before going to see Lilienthal, so as to get the greatest advantage from any original ideas he might have; he was not able to make any trials with this machine, however, until after witnessing Lilienthal's experiments and making several glides in the biplane glider which Lilienthal constructed. The wings of the 'Bat' formed a pronounced dihedral angle; the tips being raised 4 feet above the body. The spars forming the entering edges of the wings crossed each other in the centre and were lashed to opposite sides of the triangle that served as a mast for the stay-wires that guyed the wings. The four ribs of each wing, enclosed in pockets in the fabric, radiated fanwise from the centre, and were each stayed by three steel piano-wires to the top of the triangular mast, and similarly to its base. These ribs were bolted down to the triangle at their roots, and could be easily folded back on to the body when the glider was not in use. A small fixed vertical surface was carried in the rear. The framework and ribs were made entirely of Riga pine; the surface fabric was nainsook. The area of the machine was 150 square feet; its weight 45 lbs.; so that in flight, with Pilcher's weight of 145 lbs. added, it carried one and a half pounds to the square foot. Pilcher's first glides, which he carried out on a grass hill on the banks of the Clyde near Cardross, gave little result, owing to the exaggerated dihedral angle of the wings, and the absence of a horizontal tail. The 'Bat 'was consequently reconstructed with a horizontal tail plane added to the vertical one, and with the wings lowered so that the tips were only six inches above the level of the body. The machine now gave far better results; on the first glide into a head wind Pilcher rose to a height of twelve feet and remained in the the air for a third of a minute; in the second attempt a rope was used to tow the glider, which rose to twenty feet and did not come to earth again until nearly a minute had passed. With experience Pilcher was able to lengthen his glide and improve his balance, but the dropped wing tips made landing difficult, and there were many breakages. In consequence of this Pilcher built a second glider which he named the 'Beetle,' because, as he said, it looked like one. In this the square-cut wings formed almost a continuous plane, rigidly fixed to the central body, which consisted of a shaped girder. These wings were built up of five transverse bamboo spars, with two shaped ribs running from fore to aft of each wing, and were stayed overhead to a couple of masts. The tail, consisting of two discs placed crosswise (the horizontal one alone being movable), was carried high up in the rear. With the exception of the wing-spars, the whole framework was built of white pine. The wings in this machine were actually on a higher level than the operator's head; the centre of gravity was, consequently, very low, a fact which, according to Pilcher's own account, made the glider very difficult to handle. Moreover, the weight of the 'Beetle,' 80 lbs., was considerable; the body had been very solidly built to enable it to carry the engine which Pilcher was then contemplating; so that the glider carried some 225 lbs. with its area of 170 square feet--too great a mass for a single man to handle with comfort. It was in the spring of 1896 that Pilcher built his third glider, the 'Gull,' with 300 square feet of area and a weight of 55 lbs. The size of this machine rendered it unsuitable for experiment in any but very calm weather, and it incurred such damage when experiments were made in a breeze that Pilcher found it necessary to build a fourth, which he named the 'Hawk.' This machine was very soundly built, being constructed of bamboo, with the exception of the two main transverse beams. The wings were attached to two vertical masts, 7 feet high, and 8 feet apart, joined at their summits and their centres by two wooden beams. Each wing had nine bamboo ribs, radiating from its mast, which was situated at a distance of 2 feet 6 inches from the forward edge of the wing. Each rib was rigidly stayed at the top of the mast by three tie-wires, and by a similar number to the bottom of the mast, by which means the curve of each wing was maintained uniformly. The tail was formed of a triangular horizontal surface to which was affixed a triangular vertical surface, and was carried from the body on a high bamboo mast, which was also stayed from the masts by means of steel wires, but only on its upper surface, and it was the snapping of one of these guy wires which caused the collapse of the tail support and brought about the fatal end of Pilcher's experiments. In flight, Pilcher's head, shoulders, and the greater part of his chest projected above the wings. He took up his position by passing his head and shoulders through the top aperture formed between the two wings, and resting his forearms on the longitudinal body members. A very simple form of undercarriage, which took the weight off the glider on the ground, was fitted, consisting of two bamboo rods with wheels suspended on steel springs. Balance and steering were effected, apart from the high degree of inherent stability afforded by the tail, as in the case of Lilienthal's glider, by altering the position of the body. With this machine Pilcher made some twelve glides at Eynsford in Kent in the summer of 1896, and as he progressed he increased the length of his glides, and also handled the machine more easily, both in the air and in landing. He was occupied with plans for fitting an engine and propeller to the 'Hawk,' but, in these early days of the internal combustion engine, was unable to get one light enough for his purpose. There were rumours of an engine weighing 15 lbs. which gave 1 horse-power, and was reported to be in existence in America, but it could not be traced. In the spring of 1897 Pilcher took up his gliding experiments again, obtaining what was probably the best of his glides on June 19th, when he alighted after a perfectly balanced glide of over 250 yards in length, having crossed a valley at a considerable height. From his various experiments he concluded that once the machine was launched in the air an engine of, at most, 3 horse-power would suffice for the maintenance of horizontal flight, but he had to allow for the additional weight of the engine and propeller, and taking into account the comparative inefficiency of the propeller, he planned for an engine of 4 horse-power. Engine and propeller together were estimated at under 44 lbs. weight, the engine was to be fitted in front of the operator, and by means of an overhead shaft was to operate the propeller situated in rear of the wings. 1898 went by while this engine was under construction. Then in 1899 Pilcher became interested in Lawrence Hargrave's soaring kites, with which he carried out experiments during the summer of 1899. It is believed that he intended to incorporate a number of these kites in a new machine, a triplane, of which the fragments remaining are hardly sufficient to reconstitute the complete glider. This new machine was never given a trial. For on September 30th, 1899, at Stamford Hall, Market Harborough, Pilcher agreed to give a demonstration of gliding flight, but owing to the unfavourable weather he decided to postpone the trial of the new machine and to experiment with the 'Hawk,' which was intended to rise from a level field, towed by a line passing over a tackle drawn by two horses. At the first trial the machine rose easily, but the tow-line snapped when it was well clear of the ground, and the glider descended, weighed down through being sodden with rain. Pilcher resolved on a second trial, in which the glider again rose easily to about thirty feet, when one of the guy wires of the tail broke, and the tail collapsed; the machine fell to the ground, turning over, and Pilcher was unconscious when he was freed from the wreckage. Hopes were entertained of his recovery, but he died on Monday, October 2nd, 1899, aged only thirty-four. His work in the cause of flying lasted only four years, but in that time his actual accomplishments were sufficient to place his name beside that of Lilienthal, with whom he ranks as one of the greatest exponents of gliding flight. VIII. AMERICAN GLIDING EXPERIMENTS While Pilcher was carrying on Lilienthal's work in England, the great German had also a follower in America; one Octave Chanute, who, in one of the statements which he has left on the subject of his experiments acknowledges forty years' interest in the problem of flight, did more to develop the glider in America than--with the possible exception of Montgomery--any other man. Chanute had all the practicality of an American; he began his work, so far as actual gliding was concerned, with a full-sized glider of the Lilienthal type, just before Lilienthal was killed. In a rather rare monograph, entitled Experiments in Flying, Chanute states that he found the Lilienthal glider hazardous and decided to test the value of an idea of his own; in this he followed the same general method, but reversed the principle upon which Lilienthal had depended for maintaining his equilibrium in the air. Lilienthal had shifted the weight of his body, under immovable wings, as fast and as far as the sustaining pressure varied under his surfaces; this shifting was mainly done by moving the feet, as the actions required were small except when alighting. Chanute's idea was to have the operator remain seated in the machine in the air, and to intervene only to steer or to alight; moving mechanism was provided to adjust the wings automatically in order to restore balance when necessary. Chanute realised that experiments with models were of little use; in order to be fully instructive, these experiments should be made with a full-sized machine which carried its operator, for models seldom fly twice alike in the open air, and no relation can be gained from them of the divergent air currents which they have experienced. Chanute's idea was that any flying machine which might be constructed must be able to operate in a wind; hence the necessity for an operator to report upon what occurred in flight, and to acquire practical experience of the work of the human factor in imitation of bird flight. From this point of view he conducted his own experiments; it must be noted that he was over sixty years of age when he began, and, being no longer sufficiently young and active to perform any but short and insignificant glides, the courage of the man becomes all the more noteworthy; he set to work to evolve the state required by the problem of stability, and without any expectation of advancing to the construction of a flying machine which might be of commercial value. His main idea was the testing of devices to secure equilibrium; for this purpose he employed assistants to carry out the practical work, where he himself was unable to supply the necessary physical energy. Together with his assistants he found a suitable place for experiments among the sandhills on the shore of Lake Michigan, about thirty miles eastward from Chicago. Here a hill about ninety-five feet high was selected as a point from which Chanute's gliders could set off; in practice, it was found that the best observation was to be obtained from short glides at low speed, and, consequently, a hill which was only sixty-one feet above the shore of the lake was employed for the experimental work done by the party. In the years 1896 and 1897, with parties of from four to six persons, five full-sized gliders were tried out, and from these two distinct types were evolved: of these one was a machine consisting of five tiers of wings and a steering tail, and the other was of the biplane type; Chanute believed these to be safer than any other machine previously evolved, solving, as he states in his monograph, the problem of inherent equilibrium as fully as this could be done. Unfortunately, very few photographs were taken of the work in the first year, but one view of a multiple wing-glider survives, showing the machine in flight. In 1897 a series of photographs was taken exhibiting the consecutive phases of a single flight; this series of photographs represents the experience gained in a total of about one thousand glides, but the point of view was varied so as to exhibit the consecutive phases of one single flight. The experience gained is best told in Chanute's own words. 'The first thing,' he says, 'which we discovered practically was that the wind flowing up a hill-side is not a steadily-flowing current like that of a river. It comes as a rolling mass, full of tumultuous whirls and eddies, like those issuing from a chimney; and they strike the apparatus with constantly varying force and direction, sometimes withdrawing support when most needed. It has long been known, through instrumental observations, that the wind is constantly changing in force and direction; but it needed the experience of an operator afloat on a gliding machine to realise that this all proceeded from cyclonic action; so that more was learned in this respect in a week than had previously been acquired by several years of experiments with models. There was a pair of eagles, living in the top of a dead tree about two miles from our tent, that came almost daily to show us how such wind effects are overcome and utilised. The birds swept in circles overhead on pulseless wings, and rose high up in the air. Occasionally there was a side-rocking motion, as of a ship rolling at sea, and then the birds rocked back to an even keel; but although we thought the action was clearly automatic, and were willing to learn, our teachers were too far off to show us just how it was done, and we had to experiment for ourselves.' Chanute provided his multiple glider with a seat, but, since each glide only occupied between eight and twelve seconds, there was little possibility of the operator seating himself. With the multiple glider a pair of horizontal bars provided rest for the arms, and beyond these was a pair of vertical bars which the operator grasped with his hands; beyond this, the operator was in no way attached to the machine. He took, at the most, four running steps into the wind, which launched him in the air, and thereupon he sailed into the wind on a generally descending course. In the matter of descent Chanute observed the sparrow and decided to imitate it. 'When the latter,' he says, 'approaches the street, he throws his body back, tilts his outspread wings nearly square to the course, and on the cushion of air thus encountered he stops his speed and drops lightly to the ground. So do all birds. We tried it with misgivings, but found it perfectly effective. The soft sand was a great advantage, and even when the experts were racing there was not a single sprained ankle.' With the multiple winged glider some two to three hundred glides were made without any accident either to the man or to the machine, and the action was found so effective, the principle so sound, that full plans were published for the benefit of any experimenters who might wish to improve on this apparatus. The American Aeronautical Annual for 1897 contains these plans; Chanute confessed that some movement on the part of the operator was still required to control the machine, but it was only a seventh or a sixth part of the movement required for control of the Lilienthal type. Chanute waxed enthusiastic over the possibilities of gliding, concerning which he remarks that 'There is no more delightful sensation than that of gliding through the air. All the faculties are on the alert, and the motion is astonishingly smooth and elastic. The machine responds instantly to the slightest movement of the operator; the air rushes by one's ears; the trees and bushes flit away underneath, and the landing comes all too quickly. Skating, sliding, and bicycling are not to be compared for a moment to aerial conveyance, in which, perhaps, zest is added by the spice of danger. For it must be distinctly understood that there is constant danger in such preliminary experiments. When this hazard has been eliminated by further evolution, gliding will become a most popular sport.' Later experiments proved that the biplane type of glider gave better results than the rather cumbrous model consisting of five tiers of planes. Longer and more numerous glides, to the number of seven to eight hundred, were obtained, the rate of descent being about one in six. The longest distance traversed was about 120 yards, but Chanute had dreams of starting from a hill about 200 feet high, which would have given him gliding flights of 1,200 feet. He remarked that 'In consequence of the speed gained by running, the initial stage of the flight is nearly horizontal, and it is thrilling to see the operator pass from thirty to forty feet overhead, steering his machine, undulating his course, and struggling with the wind-gusts which whistle through the guy wires. The automatic mechanism restores the angle of advance when compromised by variations of the breeze; but when these come from one side and tilt the apparatus, the weight has to be shifted to right the machine... these gusts sometimes raise the machine from ten to twenty feet vertically, and sometimes they strike the apparatus from above, causing it to descend suddenly. When sailing near the ground, these vicissitudes can be counteracted by movements of the body from three to four inches; but this has to be done instantly, for neither wings nor gravity will wait on meditation. At a height of three hundred or four hundred feet the regulating mechanism would probably take care of these wind-gusts, as it does, in fact, for their minor variations. The speed of the machine is generally about seventeen miles an hour over the ground, and from twenty-two to thirty miles an hour relative to the air. Constant effort was directed to keep down the velocity, which was at times fifty-two miles an hour. This is the purpose of the starting and gliding against the wind, which thus furnishes an initial velocity without there being undue speed at the landing. The highest wind we dared to experiment in blew at thirty-one miles an hour; when the wind was stronger, we waited and watched the birds.' Chanute details an amusing little incident which occurred in the course of experiment with the biplane glider. He says that 'We had taken one of the machines to the top of the hill, and loaded its lower wings with sand to hold it while we e went to lunch. A gull came strolling inland, and flapped full-winged to inspect. He swept several circles above the machine, stretched his neck, gave a squawk and went off. Presently he returned with eleven other gulls, and they seemed to hold a conclave about one hundred feet above the big new white bird which they had discovered on the sand. They circled round after round, and once in a while there was a series of loud peeps, like those of a rusty gate, as if in conference, with sudden flutterings, as if a terrifying suggestion had been made. The bolder birds occasionally swooped downwards to inspect the monster more closely; they twisted their heads around to bring first one eye and then the other to bear, and then they rose again. After some seven or eight minutes of this performance, they evidently concluded either that the stranger was too formidable to tackle, if alive, or that he was not good to eat, if dead, and they flew off to resume fishing, for the weak point about a bird is his stomach.' The gliders were found so stable, more especially the biplane form, that in the end Chanute permitted amateurs to make trials under guidance, and throughout the whole series of experiments not a single accident occurred. Chanute came to the conclusion that any young, quick, and handy man could master a gliding machine almost as soon as he could get the hang of a bicycle, although the penalty for any mistake would be much more severe. At the conclusion of his experiments he decided that neither the multiple plane nor the biplane type of glider was sufficiently perfected for the application of motive power. In spite of the amount of automatic stability that he had obtained he considered that there was yet more to be done, and he therefore advised that every possible method of securing stability and safety should be tested, first with models, and then with full-sized machines; designers, he said, should make a point of practice in order to make sure of the action, to proportion and adjust the parts of their machine, and to eliminate hidden defects. Experimental flight, he suggested, should be tried over water, in order to break any accidental fall; when a series of experiments had proved the stability of a glider, it would then be time to apply motive power. He admitted that such a process would be both costly and slow, but, he said, that 'it greatly diminished the chance of those accidents which bring a whole line of investigation into contempt.' He saw the flying machine as what it has, in fact, been; a child of evolution, carried on step by step by one investigator after another, through the stages of doubt and perplexity which lie behind the realm of possibility, beyond which is the present day stage of actual performance and promise of ultimate success and triumph over the earlier, more cumbrous, and slower forms of the transport that we know. Chanute's monograph, from which the foregoing notes have been comprised, was written soon after the conclusion of his series of experiments. He does not appear to have gone in for further practical work, but to have studied the subject from a theoretical view-point and with great attention to the work done by others. In a paper contributed in 1900 to the American Independent, he remarks that 'Flying machines promise better results as to speed, but yet will be of limited commercial application. They may carry mails and reach other inaccessible places, but they cannot compete with railroads as carriers of passengers or freight. They will not fill the heavens with commerce, abolish custom houses, or revolutionise the world, for they will be expensive for the loads which they can carry, and subject to too many weather contingencies. Success is, however, probable. Each experimenter has added something to previous knowledge which his successors can avail of. It now seems likely that two forms of flying machines, a sporting type and an exploration type, will be gradually evolved within one or two generations, but the evolution will be costly and slow, and must be carried on by well-equipped and thoroughly informed scientific men; for the casual inventor, who relies upon one or two happy inspirations, will have no chance of success whatever.' Follows Professor John J. Montgomery, who, in the true American spirit, describes his own experiments so well that nobody can possibly do it better. His account of his work was given first of all in the American Journal, Aeronautics, in January, 1909, and thence transcribed in the English paper of the same name in May, 1910, and that account is here copied word for word. It may, however, be noted first that as far back as 1860, when Montgomery was only a boy, he was attracted to the study of aeronautical problems, and in 1883 he built his first machine, which was of the flapping-wing ornithopter type, and which showed its designer, with only one experiment, that he must design some other form of machine if he wished to attain to a successful flight. Chanute details how, in 1884 and 1885 Montgomery built three gliders, demonstrating the value of curved surfaces. With the first of these gliders Montgomery copied the wing of a seagull; with the second he proved that a flat surface was virtually useless, and with the third he pivoted his wings as in the Antoinette type of power-propelled aeroplane, proving to his own satisfaction that success lay in this direction. His own account of the gliding flights carried out under his direction is here set forth, being the best description of his work that can be obtained:-- 'When I commenced practical demonstration in my work with aeroplanes I had before me three points; first, equilibrium; second, complete control; and third, long continued or soaring flight. In starting I constructed and tested three sets of models, each in advance of the other in regard to the continuance of their soaring powers, but all equally perfect as to equilibrium and control. These models were tested by dropping them from a cable stretched between two mountain tops, with various loads, adjustments and positions. And it made no difference whether the models were dropped upside down or any other conceivable position, they always found their equilibrium immediately and glided safely to earth. 'Then I constructed a large machine patterned after the first model, and with the assistance of three cowboy friends personally made a number of flights in the steep mountains near San Juan (a hundred miles distant). In making these flights I simply took the aeroplane and made a running jump. These tests were discontinued after I put my foot into a squirrel hole in landing and hurt my leg. 'The following year I commenced the work on a larger scale, by engaging aeronauts to ride my aeroplane dropped from balloons. During this work I used five hot-air balloons and one gas balloon, five or six aeroplanes, three riders--Maloney, Wilkie, and Defolco--and had sixteen applicants on my list, and had a training station to prepare any when I needed them. 'Exhibitions were given in Santa Cruz, San Jose, Santa Clara, Oaklands, and Sacramento. The flights that were made, instead of being haphazard affairs, were in the order of safety and development. In the first flight of an aeronaut the aeroplane was so arranged that the rider had little liberty of action, consequently he could make only a limited flight. In some of the first flights, the aeroplane did little more than settle in the air. But as the rider gained experience in each successive flight I changed the adjustments, giving him more liberty of action, so he could obtain longer flights and more varied movements in the flights. But in none of the flights did I have the adjustments so that the riders had full liberty, as I did not consider that they had the requisite knowledge and experience necessary for their safety; and hence, none of my aeroplanes were launched so arranged that the rider could make adjustments necessary for a full flight. 'This line of action caused a good deal of trouble with aeronauts or riders, who had unbounded confidence and wanted to make long flights after the first few trials; but I found it necessary, as they seemed slow in comprehending the important elements and were willing to take risks. To give them the full knowledge in these matters I was formulating plans for a large starting station on the Mount Hamilton Range from which I could launch an aeroplane capable of carrying two, one of my aeronauts and myself, so I could teach him by demonstration. But the disasters consequent on the great earthquake completely stopped all my work on these lines. The flights that were given were only the first of the series with aeroplanes patterned after the first model. There were no aeroplanes constructed according to the two other models, as I had not given the full demonstration of the workings of the first, though some remarkable and startling work was done. On one occasion Maloney, in trying to make a very short turn in rapid flight, pressed very hard on the stirrup which gives a screw-shape to the wings, and made a side somersault. The course of the machine was very much like one turn of a corkscrew. After this movement the machine continued on its regular course. And afterwards Wilkie, not to be outdone by Maloney, told his friends he would do the same, and in a subsequent flight made two side somersaults, one in one direction and the other in an opposite, then made a deep dive and a long glide, and, when about three hundred feet in the air, brought the aeroplane to a sudden stop and settled to the earth. After these antics, I decreased the extent of the possible change in the form of wing-surface, so as to allow only straight sailing or only long curves in turning. 'During my work I had a few carping critics that I silenced by this standing offer: If they would deposit a thousand dollars I would cover it on this proposition. I would fasten a 150 pound sack of sand in the rider's seat, make the necessary adjustments, and send up an aeroplane upside down with a balloon, the aeroplane to be liberated by a time fuse. If the aeroplane did not immediately right itself, make a flight, and come safely to the ground, the money was theirs. 'Now a word in regard to the fatal accident. The circumstances are these: The ascension was given to entertain a military company in which were many of Maloney's friends, and he had told them he would give the most sensational flight they ever heard of. As the balloon was rising with the aeroplane, a guy rope dropping switched around the right wing and broke the tower that braced the two rear wings and which also gave control over the tail. We shouted Maloney that the machine was broken, but he probably did not hear us, as he was at the same time saying, "Hurrah for Montgomery's airship," and as the break was behind him, he may not have detected it. Now did he know of the breakage or not, and if he knew of it did he take a risk so as not to disappoint his friends? At all events, when the machine started on its flight the rear wings commenced to flap (thus indicating they were loose), the machine turned on its back, and settled a little faster than a parachute. When we reached Maloney he was unconscious and lived only thirty minutes. The only mark of any kind on him was a scratch from a wire on the side of his neck. The six attending physicians were puzzled at the cause of his death. This is remarkable for a vertical descent of over 2,000 feet.' The flights were brought to an end by the San Francisco earthquake in April, 1906, which, Montgomery states, 'Wrought such a disaster that I had to turn my attention to other subjects and let the aeroplane rest for a time.' Montgomery resumed experiments in 1911 in California, and in October of that year an accident brought his work to an end. The report in the American Aeronautics says that 'a little whirlwind caught the machine and dashed it head on to the ground; Professor Montgomery landed on his head and right hip. He did not believe himself seriously hurt, and talked with his year-old bride in the tent. He complained of pains in his back, and continued to grow worse until he died.' IX. NOT PROVEN The early history of flying, like that of most sciences, is replete with tragedies; in addition to these it contains one mystery concerning Clement Ader, who was well known among European pioneers in the development of the telephone, and first turned his attention to the problems of mechanical flight in 1872. At the outset he favoured the ornithopter principle, constructing a machine in the form of a bird with a wing-spread of twenty-six feet; this, according to Ader's conception, was to fly through the efforts of the operator. The result of such an attempt was past question and naturally the machine never left the ground. A pause of nineteen years ensued, and then in 1886 Ader turned his mind to the development of the aeroplane, constructing a machine of bat-like form with a wingspread of about forty-six feet, a weight of eleven hundred pounds, and a steam-power plant of between twenty and thirty horse-power driving a four-bladed tractor screw. On October 9th, 1890, the first trials of this machine were made, and it was alleged to have flown a distance of one hundred and sixty-four feet. Whatever truth there may be in the allegation, the machine was wrecked through deficient equilibrium at the end of the trial. Ader repeated the construction, and on October 14th, 1897, tried out his third machine at the military establishment at Satory in the presence of the French military authorities, on a circular track specially prepared for the experiment. Ader and his friends alleged that a flight of nearly a thousand feet was made; again the machine was wrecked at the end of the trial, and there Ader's practical work may be said to have ended, since no more funds were forthcoming for the subsidy of experiments. There is the bald narrative, but it is worthy of some amplification. If Ader actually did what he claimed, then the position which the Wright Brothers hold as first to navigate the air in a power-driven plane is nullified. Although at this time of writing it is not a quarter of a century since Ader's experiment in the presence of witnesses competent to judge on his accomplishment, there is no proof either way, and whether he was or was not the first man to fly remains a mystery in the story of the conquest of the air. The full story of Ader's work reveals a persistence and determination to solve the problem that faced him which was equal to that of Lilienthal. He began by penetrating into the interior of Algeria after having disguised himself as an Arab, and there he spent some months in studying flight as practiced by the vultures of the district. Returning to France in 1886 he began to construct the 'Eole,' modelling it, not on the vulture, but in the shape of a bat. Like the Lilienthal and Pilcher gliders this machine was fitted with wings which could be folded; the first flight made, as already noted, on October 9th, 1890, took place in the grounds of the chateau d'Amainvilliers, near Bretz; two fellow-enthusiasts named Espinosa and Vallier stated that a flight was actually made; no statement in the history of aeronautics has been subject of so much question, and the claim remains unproved. It was in September of 1891 that Ader, by permission of the Minister of War, moved the 'Eole' to the military establishment at Satory for the purpose of further trial. By this time, whether he had flown or not, his nineteen years of work in connection with the problems attendant on mechanical flight had attracted so much attention that henceforth his work was subject to the approval of the military authorities, for already it was recognised that an efficient flying machine would confer an inestimable advantage on the power that possessed it in the event of war. At Satory the 'Eole' was alleged to have made a flight of 109 yards, or, according to another account, 164 feet, as stated above, in the trial in which the machine wrecked itself through colliding with some carts which had been placed near the track--the root cause of this accident, however, was given as deficient equilibrium. Whatever the sceptics may say, there is reason for belief in the accomplishment of actual flight by Ader with his first machine in the fact that, after the inevitable official delay of some months, the French War Ministry granted funds for further experiment. Ader named his second machine, which he began to build in May, 1892, the 'Avion,' and--an honour which he well deserve--that name remains in French aeronautics as descriptive of the power-driven aeroplane up to this day. This second machine, however, was not a success, and it was not until 1897 that the second 'Avion,' which was the third power-driven aeroplane of Ader's construction, was ready for trial. This was fitted with two steam motors of twenty horse-power each, driving two four-bladed propellers; the wings warped automatically: that is to say, if it were necessary to raise the trailing edge of one wing on the turn, the trailing edge of the opposite wing was also lowered by the same movement; an under-carriage was also fitted, the machine running on three small wheels, and levers controlled by the feet of the aviator actuated the movement of the tail planes. On October the 12th, 1897, the first trials of this 'Avion' were made in the presence of General Mensier, who admitted that the machine made several hops above the ground, but did not consider the performance as one of actual flight. The result was so encouraging, in spite of the partial failure, that, two days later, General Mensier, accompanied by General Grillon, a certain Lieutenant Binet, and two civilians named respectively Sarrau and Leaute, attended for the purpose of giving the machine an official trial, over which the great controversy regarding Ader's success or otherwise may be said to have arisen. We will take first Ader's own statement as set out in a very competent account of his work published in Paris in 1910. Here are Ader's own words: 'After some turns of the propellers, and after travelling a few metres, we started off at a lively pace; the pressure-gauge registered about seven atmospheres; almost immediately the vibrations of the rear wheel ceased; a little later we only experienced those of the front wheels at intervals. 'Unhappily, the wind became suddenly strong, and we had some difficulty in keeping the "Avion" on the white line. We increased the pressure to between eight and nine atmospheres, and immediately the speed increased considerably, and the vibrations of the wheels were no longer sensible; we were at that moment at the point marked G in the sketch; the "Avion" then found itself freely supported by its wings; under the impulse of the wind it continually tended to go outside the (prepared) area to the right, in spite of the action of the rudder. On reaching the point V it found itself in a very critical position; the wind blew strongly and across the direction of the white line which it ought to follow; the machine then, although still going forward, drifted quickly out of the area; we immediately put over the rudder to the left as far as it would go; at the same time increasing the pressure still more, in order to try to regain the course. The "Avion" obeyed, recovered a little, and remained for some seconds headed towards its intended course, but it could not struggle against the wind; instead of going back, on the contrary it drifted farther and farther away. And ill-luck had it that the drift took the direction towards part of the School of Musketry, which was guarded by posts and barriers. Frightened at the prospect of breaking ourselves against these obstacles, surprised at seeing the earth getting farther away from under the "Avion," and very much impressed by seeing it rushing sideways at a sickening speed, instinctively we stopped everything. What passed through our thoughts at this moment which threatened a tragic turn would be difficult to set down. All at once came a great shock, splintering, a heavy concussion: we had landed.' Thus speaks the inventor; the cold official mind gives out a different account, crediting the 'Avion' with merely a few hops, and to-day, among those who consider the problem at all, there is a little group which persists in asserting that to Ader belongs the credit of the first power-driven flight, while a larger group is equally persistent in stating that, save for a few ineffectual hops, all three wheels of the machine never left the ground. It is past question that the 'Avion' was capable of power-driven flight; whether it achieved it or no remains an unsettled problem. Ader's work is negative proof of the value of such experiments as Lilienthal, Pilcher, Chanute, and Montgomery conducted; these four set to work to master the eccentricities of the air before attempting to use it as a supporting medium for continuous flight under power; Ader attacked the problem from the other end; like many other experimenters he regarded the air as a stable fluid capable of giving such support to his machine as still water might give to a fish, and he reckoned that he had only to produce the machine in order to achieve flight. The wrecked 'Avion' and the refusal of the French War Ministry to grant any more funds for further experiment are sufficient evidence of the need for working along the lines taken by the pioneers of gliding rather than on those which Ader himself adopted. Let it not be thought that in this comment there is any desire to derogate from the position which Ader should occupy in any study of the pioneers of aeronautical enterprise. If he failed, he failed magnificently, and if he succeeded, then the student of aeronautics does him an injustice and confers on the Brothers Wright an honour which, in spite of the value of their work, they do not deserve. There was one earlier than Ader, Alphonse Penaud, who, in the face of a lesser disappointment than that which Ader must have felt in gazing on the wreckage of his machine, committed suicide; Ader himself, rendered unable to do more, remained content with his achievement, and with the knowledge that he had played a good part in the long search which must eventually end in triumph. Whatever the world might say, he himself was certain that he had achieved flight. This, for him, was perforce enough. Before turning to consideration of the work accomplished by the Brothers Wright, and their proved conquest of the air, it is necessary first to sketch as briefly as may be the experimental work of Sir (then Mr) Hiram Maxim, who, in his book, Artificial and Natural Flight, has given a fairly complete account of his various experiments. He began by experimenting with models, with screw-propelled planes so attached to a horizontal movable arm that when the screw was set in motion the plane described a circle round a central point, and, eventually, he built a giant aeroplane having a total supporting area of 1,500 square feet, and a wing-span of fifty feet. It has been thought advisable to give a fairly full description of the power plant used to the propulsion of this machine in the section devoted to engine development. The aeroplane, as Maxim describes it, had five long and narrow planes projecting from each side, and a main or central plane of pterygoid aspect. A fore and aft rudder was provided, and had all the auxiliary planes been put in position for experimental work a total lifting surface of 6,000 square feet could have been obtained. Maxim, however, did not use more than 4,000 square feet of lifting surface even in his later experiments; with this he judged the machine capable of lifting slightly under 8,000 lbs. weight, made up of 600 lbs. water in the boiler and tank, a crew of three men, a supply of naphtha fuel, and the weight of the machine itself. Maxim's intention was, before attempting free flight, to get as much data as possible regarding the conditions under which flight must be obtained, by what is known in these days as 'taxi-ing'--that is, running the propellers at sufficient speed to drive the machine along the ground without actually mounting into the air. He knew that he had an immense lifting surface and a tremendous amount of power in his engine even when the total weight of the experimental plant was taken into consideration, and thus he set about to devise some means of keeping the machine on the nine foot gauge rail track which had been constructed for the trials. At the outset he had a set of very heavy cast-iron wheels made on which to mount the machine, the total weight of wheels, axles, and connections being about one and a half tons. These were so constructed that the light flanged wheels which supported the machine on the steel rails could be lifted six inches above the track, still leaving the heavy wheels on the rails for guidance of the machine. 'This arrangement,' Maxim states, 'was tried on several occasions, the machine being run fast enough to lift the forward end off the track. However, I found considerable difficulty in starting and stopping quickly on account of the great weight, and the amount of energy necessary to set such heavy wheels spinning at a high velocity. The last experiment with these wheels was made when a head wind was blowing at the rate of about ten miles an hour. It was rather unsteady, and when the machine was running at its greatest velocity, a sudden gust lifted not only the front end, but also the heavy front wheels completely off the track, and the machine falling on soft ground was soon blown over by the wind.' Consequently, a safety track was provided, consisting of squared pine logs, three inches by nine inches, placed about two feet above the steel way and having a thirty-foot gauge. Four extra wheels were fitted to the machine on outriggers and so adjusted that, if the machine should lift one inch clear of the steel rails, the wheels at the ends of the outriggers would engage the under side of the pine trackway. The first fully loaded run was made in a dead calm with 150 lbs. steam pressure to the square inch, and there was no sign of the wheels leaving the steel track. On a second run, with 230 lbs. steam pressure the machine seemed to alternate between adherence to the lower and upper tracks, as many as three of the outrigger wheels engaging at the same time, and the weight on the steel rails being reduced practically to nothing. In preparation for a third run, in which it was intended to use full power, a dynamometer was attached to the machine and the engines were started at 200 lbs. pressure, which was gradually increased to 310 lbs per square inch. The incline of the track, added to the reading of the dynamometer, showed a total screw thrust of 2,164 lbs. After the dynamometer test had been completed, and everything had been made ready for trial in motion, careful observers were stationed on each side of the track, and the order was given to release the machine. What follows is best told in Maxim's own words:-- 'The enormous screw-thrust started the engine so quickly that it nearly threw the engineers off their feet, and the machine bounded over the track at a great rate. Upon noticing a slight diminution in the steam pressure, I turned on more gas, when almost instantly the steam commenced to blow a steady blast from the small safety valve, showing that the pressure was at least 320 lbs. in the pipes supplying the engines with steam. Before starting on this run, the wheels that were to engage the upper track were painted, and it was the duty of one of my assistants to observe these wheels during the run, while another assistant watched the pressure gauges and dynagraphs. The first part of the track was up a slight incline, but the machine was lifted clear of the lower rails and all of the top wheels were fully engaged on the upper track when about 600 feet had been covered. The speed rapidly increased, and when 900 feet had been covered, one of the rear axle trees, which were of two-inch steel tubing, doubled up and set the rear end of the machine completely free. The pencils ran completely across the cylinders of the dynagraphs and caught on the underneath end. The rear end of the machine being set free, raised considerably above the track and swayed. At about 1,000 feet, the left forward wheel also got clear of the upper track, and shortly afterwards the right forward wheel tore up about 100 feet of the upper track. Steam was at once shut off and the machine sank directly to the earth, embedding the wheels in the soft turf without leaving any other marks, showing most conclusively that the machine was completely suspended in the air before it settled to the earth. In this accident, one of the pine timbers forming the upper track went completely through the lower framework of the machine and broke a number of the tubes, but no damage was done to the machinery except a slight injury to one of the screws.' It is a pity that the multifarious directions in which Maxim turned his energies did not include further development of the aeroplane, for it seems fairly certain that he was as near solution of the problem as Ader himself, and, but for the holding-down outer track, which was really the cause of his accident, his machine would certainly have achieved free flight, though whether it would have risen, flown and alighted, without accident, is matter for conjecture. The difference between experiments with models and with full-sized machines is emphasised by Maxim's statement to the effect that with a small apparatus for ascertaining the power required for artificial flight, an angle of incidence of one in fourteen was most advantageous, while with a large machine he found it best to increase his angle to one in eight in order to get the maximum lifting effect on a short run at a moderate speed. He computed the total lifting effect in the experiments which led to the accident as not less than 10,000 lbs., in which is proof that only his rail system prevented free flight. X. SAMUEL PIERPOINT LANGLEY Langley was an old man when he began the study of aeronautics, or, as he himself might have expressed it, the study of aerodromics, since he persisted in calling the series of machines he built 'Aerodromes,' a word now used only to denote areas devoted to use as landing spaces for flying machines; the Wright Brothers, on the other hand, had the great gift of youth to aid them in their work. Even so it was a great race between Langley, aided by Charles Manly, and Wilbur and Orville Wright, and only the persistent ill-luck which dogged Langley from the start to the finish of his experiments gave victory to his rivals. It has been proved conclusively in these later years of accomplished flight that the machine which Langley launched on the Potomac River in October of 1903 was fully capable of sustained flight, and only the accidents incurred in launching prevented its pilot from being the first man to navigate the air successfully in a power-driven machine. The best account of Langley's work is that diffused throughout a weighty tome issued by the Smithsonian Institution, entitled the Langley Memoir on Mechanical Flight, of which about one-third was written by Langley himself, the remainder being compiled by Charles M. Manly, the engineer responsible for the construction of the first radial aero-engine, and chief assistant to Langley in his experiments. To give a twentieth of the contents of this volume in the present short account of the development of mechanical flight would far exceed the amount of space that can be devoted even to so eminent a man in aeronautics as S. P. Langley, who, apart from his achievement in the construction of a power-driven aeroplane really capable of flight, was a scientist of no mean order, and who brought to the study of aeronautics the skill of the trained investigator allied to the inventive resource of the genius. That genius exemplified the antique saw regarding the infinite capacity for taking pains, for the Langley Memoir shows that as early as 1891 Langley had completed a set of experiments, lasting through years, which proved it possible to construct machines giving such a velocity to inclined surfaces that bodies indefinitely heavier than air could be sustained upon it and propelled through it at high speed. For full account (very full) of these experiments, and of a later series leading up to the construction of a series of 'model aerodromes' capable of flight under power, it is necessary to turn to the bulky memoir of Smithsonian origin. The account of these experiments as given by Langley himself reveals the humility of the true investigator. Concerning them, Langley remarks that, 'Everything here has been done with a view to putting a trial aerodrome successfully in flight within a few years, and thus giving an early demonstration of the only kind which is conclusive in the eyes of the scientific man, as well as of the general public--a demonstration that mechanical flight is possible--by actually flying. All that has been done has been with an eye principally to this immediate result, and all the experiments given in this book are to be considered only as approximations to exact truth. All were made with a view, not to some remote future, but to an arrival within the compass of a few years at some result in actual flight that could not be gainsaid or mistaken.' With a series of over thirty rubber-driven models Langley demonstrated the practicability of opposing curved surfaces to the resistance of the air in such a way as to achieve flight, in the early nineties of last century; he then set about finding the motive power which should permit of the construction of larger machines, up to man-carrying size. The internal combustion engine was then an unknown quantity, and he had to turn to steam, finally, as the propulsive energy for his power plant. The chief problem which faced him was that of the relative weight and power of his engine; he harked back to the Stringfellow engine of 1868, which in 1889 came into the possession of the Smithsonian Institution as a historical curiosity. Rightly or wrongly Langley concluded on examination that this engine never had developed and never could develop more than a tenth of the power attributed to it; consequently he abandoned the idea of copying the Stringfellow design and set about making his own engine. How he overcame the various difficulties that faced him and constructed a steam-engine capable of the task allotted to it forms a story in itself, too long for recital here. His first power-driven aerodrome of model size was begun in November of 1891, the scale of construction being decided with the idea that it should be large enough to carry an automatic steering apparatus which would render the machine capable of maintaining a long and steady flight. The actual weight of the first model far exceeded the theoretical estimate, and Langley found that a constant increase of weight under the exigencies of construction was a feature which could never be altogether eliminated. The machine was made principally of steel, the sustaining surfaces being composed of silk stretched from a steel tube with wooden attachments. The first engines were the oscillating type, but were found deficient in power. This led to the construction of single-acting inverted oscillating engines with high and low pressure cylinders, and with admission and exhaust ports to avoid the complication and weight of eccentric and valves. Boiler and furnace had to be specially designed; an analysis of sustaining surfaces and the settlement of equilibrium while in flight had to be overcome, and then it was possible to set about the construction of the series of model aerodromes and make test of their 'lift.' By the time Langley had advanced sufficiently far to consider it possible to conduct experiments in the open air, even with these models, he had got to his fifth aerodrome, and to the year 1894. Certain tests resulted in failure, which in turn resulted in further modifications of design, mainly of the engines. By February of 1895 Langley reported that under favourable conditions a lift of nearly sixty per cent of the flying weight was secured, but although this was much more than was required for flight, it was decided to postpone trials until two machines were ready for the test. May, 1896, came before actual trials were made, when one machine proved successful and another, a later design, failed. The difficulty with these models was that of securing a correct angle for launching; Langley records how, on launching one machine, it rose so rapidly that it attained an angle of sixty degrees and then did a tail slide into the water with its engines working at full speed, after advancing nearly forty feet and remaining in the air for about three seconds. Here, Langley found that he had to obtain greater rigidity in his wings, owing to the distortion of the form of wing under pressure, and how he overcame this difficulty constitutes yet another story too long for the telling here. Field trials were first attempted in 1893, and Langley blamed his launching apparatus for their total failure. There was a brief, but at the same time practical, success in model flight in 1894, extending to between six and seven seconds, but this only proved the need for strengthening of the wing. In 1895 there was practically no advance toward the solution of the problem, but the flights of May 6th and November 28th, 1896, were notably successful. A diagram given in Langley's memoir shows the track covered by the aerodrome on these two flights; in the first of them the machine made three complete circles, covering a distance of 3,200 feet; in the second, that of November 28th, the distance covered was 4,200 feet, or about three-quarters of a mile, at a speed of about thirty miles an hour. These achievements meant a good deal; they proved mechanically propelled flight possible. The difference between them and such experiments as were conducted by Clement Ader, Maxim, and others, lay principally in the fact that these latter either did or did not succeed in rising into the air once, and then, either willingly or by compulsion, gave up the quest, while Langley repeated his experiments and thus attained to actual proof of the possibilities of flight. Like these others, however, he decided in 1896 that he would not undertake the construction of a large man-carrying machine. In addition to a multitude of actual duties, which left him practically no time available for original research, he had as an adverse factor fully ten years of disheartening difficulties in connection with his model machines. It was President McKinley who, by requesting Langley to undertake the construction and test of a machine which might finally lead to the development of a flying machine capable of being used in warfare, egged him on to his final experiment. Langley's acceptance of the offer to construct such a machine is contained in a letter addressed from the Smithsonian Institution on December 12th, 1898, to the Board of Ordnance and Fortification of the United States War Department; this letter is of such interest as to render it worthy of reproduction:-- 'Gentlemen,--In response to your invitation I repeat what I had the honour to say to the Board--that I am willing, with the consent of the Regents of this Institution, to undertake for the Government the further investigation of the subject of the construction of a flying machine on a scale capable of carrying a man, the investigation to include the construction, development and test of such a machine under conditions left as far as practicable in my discretion, it being understood that my services are given to the Government in such time as may not be occupied by the business of the Institution, and without charge. 'I have reason to believe that the cost of the construction will come within the sum of $50,000.00, and that not more than one-half of that will be called for in the coming year. 'I entirely agree with what I understand to be the wish of the Board that privacy be observed with regard to the work, and only when it reaches a successful completion shall I wish to make public the fact of its success. 'I attach to this a memorandum of my understanding of some points of detail in order to be sure that it is also the understanding of the Board, and I am, gentlemen, with much respect, your obedient servant, S. P. Langley.' One of the chief problems in connection with the construction of a full-sized apparatus was that of the construction of an engine, for it was realised from the first that a steam power plant for a full-sized machine could only be constructed in such a way as to make it a constant menace to the machine which it was to propel. By this time (1898) the internal combustion engine had so far advanced as to convince Langley that it formed the best power plant available. A contract was made for the delivery of a twelve horse-power engine to weigh not more than a hundred pounds, but this contract was never completed, and it fell to Charles M. Manly to design the five-cylinder radial engine, of which a brief account is included in the section of this work devoted to aero engines, as the power plant for the Langley machine. The history of the years 1899 to 1903 in the Langley series of experiments contains a multitude of detail far beyond the scope of this present study, and of interest mainly to the designer. There were frames, engines, and propellers, to be considered, worked out, and constructed. We are concerned here mainly with the completed machine and its trials. Of these latter it must be remarked that the only two actual field trials which took place resulted in accidents due to the failure of the launching apparatus, and not due to any inherent defect in the machine. It was intended that these two trials should be the first of a series, but the unfortunate accidents, and the fact that no further funds were forthcoming for continuance of experiments, prevented Langley's success, which, had he been free to go through as he intended with his work, would have been certain. The best brief description of the Langley aerodrome in its final form, and of the two attempted trials, is contained in the official report of Major M. M. Macomb of the United States Artillery Corps, which report is here given in full:-- REPORT Experiments with working models which were concluded August 8 last having proved the principles and calculations on which the design of the Langley aerodrome was based to be correct, the next step was to apply these principles to the construction of a machine of sufficient size and power to permit the carrying of a man, who could control the motive power and guide its flight, thus pointing the way to attaining the final goal of producing a machine capable of such extensive and precise aerial flight, under normal atmospheric conditions, as to prove of military or commercial utility. Mr C. M. Manly, working under Professor Langley, had, by the summer of 1903, succeeded in completing an engine-driven machine which under favourable atmospheric conditions was expected to carry a man for any time up to half an hour, and to be capable of having its flight directed and controlled by him. The supporting surface of the wings was ample, and experiment showed the engine capable of supplying more than the necessary motive power. Owing to the necessity of lightness, the weight of the various elements had to be kept at a minimum, and the factor of safety in construction was therefore exceedingly small, so that the machine as a whole was delicate and frail and incapable of sustaining any unusual strain. This defect was to be corrected in later models by utilising data gathered in future experiments under varied conditions. One of the most remarkable results attained was the production of a gasoline engine furnishing over fifty continuous horse-power for a weight of 120 lbs. The aerodrome, as completed and prepared for test, is briefly described by Professor Langley as 'built of steel, weighing complete about 730 lbs., supported by 1,040 feet of sustaining surface, having two propellers driven by a gas engine developing continuously over fifty brake horse-power.' The appearance of the machine prepared for flight was exceedingly light and graceful, giving an impression to all observers of being capable of successful flight. On October 7 last everything was in readiness, and I witnessed the attempted trial on that day at Widewater, Va. On the Potomac. The engine worked well and the machine was launched at about 12.15 p.m. The trial was unsuccessful because the front guy-post caught in its support on the launching car and was not released in time to give free flight, as was intended, but, on the contrary, caused the front of the machine to be dragged downward, bending the guy-post and making the machine plunge into the water about fifty yards in front of the house-boat. The machine was subsequently recovered and brought back to the house-boat. The engine was uninjured and the frame only slightly damaged, but the four wings and rudder were practically destroyed by the first plunge and subsequent towing back to the house-boat. This accident necessitated the removal of the house-boat to Washington for the more convenient repair of damages. On December 8 last, between 4 and 5 p.m., another attempt at a trial was made, this time at the junction of the Anacostia with the Potomac, just below Washington Barracks. On this occasion General Randolph and myself represented the Board of Ordnance and Fortification. The launching car was released at 4.45 p.m. being pointed up the Anacostia towards the Navy Yard. My position was on the tug Bartholdi, about 150 feet from and at right angles to the direction of proposed flight. The car was set in motion and the propellers revolved rapidly, the engine working perfectly, but there was something wrong with the launching. The rear guy-post seemed to drag, bringing the rudder down on the launching ways, and a crashing, rending sound, followed by the collapse of the rear wings, showed that the machine had been wrecked in the launching, just how, it was impossible for me to see. The fact remains that the rear wings and rudder were wrecked before the machine was free of the ways. Their collapse deprived the machine of its support in the rear, and it consequently reared up in front under the action of the motor, assumed a vertical position, and then toppled over to the rear, falling into the water a few feet in front of the boat. Mr Manly was pulled out of the wreck uninjured and the wrecked machine--was subsequently placed upon the house-boat, and the whole brought back to Washington. From what has been said it will be seen that these unfortunate accidents have prevented any test of the apparatus in free flight, and the claim that an engine-driven, man-carrying aerodrome has been constructed lacks the proof which actual flight alone can give. Having reached the present stage of advancement in its development, it would seem highly desirable, before laying down the investigation, to obtain conclusive proof of the possibility of free flight, not only because there are excellent reasons to hope for success, but because it marks the end of a definite step toward the attainment of the final goal. Just what further procedure is necessary to secure successful flight with the large aerodrome has not yet been decided upon. Professor Langley is understood to have this subject under advisement, and will doubtless inform the Board of his final conclusions as soon as practicable. In the meantime, to avoid any possible misunderstanding, it should be stated that even after a successful test of the present great aerodrome, designed to carry a man, we are still far from the ultimate goal, and it would seem as if years of constant work and study by experts, together with the expenditure of thousands of dollars, would still be necessary before we can hope to produce an apparatus of practical utility on these lines.--Washington, January 6, 1904. A subsequent report of the Board of ordnance and Fortification to the Secretary of War embodied the principal points in Major Macomb's report, but as early as March 3rd, 1904, the Board came to a similar conclusion to that of the French Ministry of War in respect of Clement Ader's work, stating that it was not 'prepared to make an additional allotment at this time for continuing the work.' This decision was in no small measure due to hostile newspaper criticisms. Langley, in a letter to the press explaining his attitude, stated that he did not wish to make public the results of his work till these were certain, in consequence of which he refused admittance to newspaper representatives, and this attitude produced a hostility which had effect on the United States Congress. An offer was made to commercialise the invention, but Langley steadfastly refused it. Concerning this, Manly remarks that Langley had 'given his time and his best labours to the world without hope of remuneration, and he could not bring himself, at his stage of life, to consent to capitalise his scientific work.' The final trial of the Langley aerodrome was made on December 8th, 1903; nine days later, on December 17th, the Wright Brothers made their first flight in a power-propelled machine, and the conquest of the air was thus achieved. But for the two accidents that spoilt his trials, the honour which fell to the Wright Brothers would, beyond doubt, have been secured by Samuel Pierpoint Langley. XI. THE WRIGHT BROTHERS Such information as is given here concerning the Wright Brothers is derived from the two best sources available, namely, the writings of Wilbur Wright himself, and a lecture given by Dr Griffith Brewer to members of the Royal Aeronautical Society. There is no doubt that so far as actual work in connection with aviation accomplished by the two brothers is concerned, Wilbur Wright's own statements are the clearest and best available. Apparently Wilbur was, from the beginning, the historian of the pair, though he himself would have been the last to attempt to detract in any way from the fame that his brother's work also deserves. Throughout all their experiments the two were inseparable, and their work is one indivisible whole; in fact, in every department of that work, it is impossible to say where Orville leaves off and where Wilbur begins. It is a great story, this of the Wright Brothers, and one worth all the detail that can be spared it. It begins on the 16th April, 1867, when Wilbur Wright was born within eight miles of Newcastle, Indiana. Before Orville's birth on the 19th August, 1871, the Wright family had moved to Dayton, Ohio, and settled on what is known as the 'West Side' of the town. Here the brothers grew up, and, when Orville was still a boy in his teens, he started a printing business, which, as Griffith Brewer remarks, was only limited by the smallness of his machine and small quantity of type at his disposal. This machine was in such a state that pieces of string and wood were incorporated in it by way of repair, but on it Orville managed to print a boys' paper which gained considerable popularity in Dayton 'West Side.' Later, at the age of seventeen, he obtained a more efficient outfit, with which he launched a weekly newspaper, four pages in size, entitled The West Side News. After three months' running the paper was increased in size and Wilbur came into the enterprise as editor, Orville remaining publisher. In 1894 the two brothers began the publication of a weekly magazine, Snap-Shots, to which Wilbur contributed a series of articles on local affairs that gave evidence of the incisive and often sarcastic manner in which he was able to express himself throughout his life. Dr Griffith Brewer describes him as a fearless critic, who wrote on matters of local interest in a kindly but vigorous manner, which did much to maintain the healthy public municipal life of Dayton. Editorial and publishing enterprise was succeeded by the formation, just across the road from the printing works, of the Wright Cycle Company, where the two brothers launched out as cycle manufacturers with the 'Van Cleve' bicycle, a machine of great local repute for excellence of construction, and one which won for itself a reputation that lasted long after it had ceased to be manufactured. The name of the machine was that of an ancestor of the brothers, Catherine Van Cleve, who was one of the first settlers at Dayton, landing there from the River Miami on April 1st, 1796, when the country was virgin forest. It was not until 1896 that the mechanical genius which characterised the two brothers was turned to the consideration of aeronautics. In that year they took up the problem thoroughly, studying all the aeronautical information then in print. Lilienthal's writings formed one basis for their studies, and the work of Langley assisted in establishing in them a confidence in the possibility of a solution to the problems of mechanical flight. In 1909, at the banquet given by the Royal Aero Club to the Wright Brothers on their return to America, after the series of demonstration flights carried out by Wilbur Wright on the Continent, Wilbur paid tribute to the great pioneer work of Stringfellow, whose studies and achievements influenced his own and Orville's early work. He pointed out how Stringfellow devised an aeroplane having two propellers and vertical and horizontal steering, and gave due place to this early pioneer of mechanical flight. Neither of the brothers was content with mere study of the work of others. They collected all the theory available in the books published up to that time, and then built man-carrying gliders with which to test the data of Lilienthal and such other authorities as they had consulted. For two years they conducted outdoor experiments in order to test the truth or otherwise of what were enunciated as the principles of flight; after this they turned to laboratory experiments, constructing a wind tunnel in which they made thousands of tests with models of various forms of curved planes. From their experiments they tabulated thousands of readings, which Griffith Brewer remarks as giving results equally efficient with those of the elaborate tables prepared by learned institutions. Wilbur Wright has set down the beginnings of the practical experiments made by the two brothers very clearly. 'The difficulties,' he says, 'which obstruct the pathway to success in flying machine construction are of three general classes: (1) Those which relate to the construction of the sustaining wings; (2) those which relate to the generation and application of the power required to drive the machine through the air; (3) those relating to the balancing and steering of the machine after it is actually in flight. Of these difficulties two are already to a certain extent solved. Men already know how to construct wings, or aeroplanes, which, when driven through the air at sufficient speed, will not only sustain the weight of the wings themselves, but also that of the engine and the engineer as well. Men also know how to build engines and' screws of sufficient lightness and power to drive these planes at sustaining speed. Inability to balance and steer still confronts students of the flying problem, although nearly ten years have passed (since Lilienthal's success). When this one feature has been worked out, the age of flying machines will have arrived, for all other difficulties are of minor importance. 'The person who merely watches the flight of a bird gathers the impression that the bird has nothing to think of but the flapping of its wings. As a matter of fact, this is a very small part of its mental labour. Even to mention all the things the bird must constantly keep in mind in order to fly securely through the air would take a considerable time. If I take a piece of paper and, after placing it parallel with the ground, quickly let it fall, it will not settle steadily down as a staid, sensible piece of paper ought to do, but it insists on contravening every recognised rule of decorum, turning over and darting hither and thither in the most erratic manner, much after the style of an untrained horse. Yet this is the style of steed that men must learn to manage before flying can become an everyday sport. The bird has learned this art of equilibrium, and learned it so thoroughly that its skill is not apparent to our sight. We only learn to appreciate it when we can imitate it. 'Now, there are only two ways of learning to ride a fractious horse: one is to get on him and learn by actual practice how each motion and trick may be best met; the other is to sit on a fence and watch the beast awhile, and then retire to the house and at leisure figure out the best way of overcoming his jumps and kicks. The latter system is the safer, but the former, on the whole, turns out the larger proportion of good riders. It is very much the same in learning to ride a flying machine; if you are looking for perfect safety you will do well to sit on a fence and watch the birds, but if you really wish to learn you must mount a machine and become acquainted with its tricks by actual trial. The balancing of a gliding or flying machine is very simple in theory. It merely consists in causing the centre of pressure to coincide with the centre of gravity.' These comments are taken from a lecture delivered by Wilbur Wright before the Western Society of Engineers in September of 1901, under the presidency of Octave Chanute. In that lecture Wilbur detailed the way in which he and his brother came to interest themselves in aeronautical problems and constructed their first glider. He speaks of his own notice of the death of Lilienthal in 1896, and of the way in which this fatality roused him to an active interest in aeronautical problems, which was stimulated by reading Professor Marey's Animal Mechanism, not for the first time. 'From this I was led to read more modern works, and as my brother soon became equally interested with myself, we soon passed from the reading to the thinking, and finally to the working stage. It seemed to us that the main reason why the problem had remained so long unsolved was that no one had been able to obtain any adequate practice. We figured that Lilienthal in five years of time had spent only about five hours in actual gliding through the air. The wonder was not that he had done so little, but that he had accomplished so much. It would not be considered at all safe for a bicycle rider to attempt to ride through a crowded city street after only five hours' practice, spread out in bits of ten seconds each over a period of five years; yet Lilienthal with this brief practice was remarkably successful in meeting the fluctuations and eddies of wind-gusts. We thought that if some method could be found by which it would be possible to practice by the hour instead of by the second there would be hope of advancing the solution of a very difficult problem. It seemed feasible to do this by building a machine which would be sustained at a speed of eighteen miles per hour, and then finding a locality where winds of this velocity were common. With these conditions a rope attached to the machine to keep it from floating backward would answer very nearly the same purpose as a propeller driven by a motor, and it would be possible to practice by the hour, and without any serious danger, as it would not be necessary to rise far from the ground, and the machine would not have any forward motion at all. We found, according to the accepted tables of air pressure on curved surfaces, that a machine spreading 200 square feet of wing surface would be sufficient for our purpose, and that places would easily be found along the Atlantic coast where winds of sixteen to twenty-five miles were not at all uncommon. When the winds were low it was our plan to glide from the tops of sandhills, and when they were sufficiently strong to use a rope for our motor and fly over one spot. Our next work was to draw up the plans for a suitable machine. After much study we finally concluded that tails were a source of trouble rather than of assistance, and therefore we decided to dispense with them altogether. It seemed reasonable that if the body of the operator could be placed in a horizontal position instead of the upright, as in the machines of Lilienthal, Pilcher, and Chanute, the wind resistance could be very materially reduced, since only one square foot instead of five would be exposed. As a full half horse-power would be saved by this change, we arranged to try at least the horizontal position. Then the method of control used by Lilienthal, which consisted in shifting the body, did not seem quite as quick or effective as the case required; so, after long study, we contrived a system consisting of two large surfaces on the Chanute double-deck plan, and a smaller surface placed a short distance in front of the main surfaces in such a position that the action of the wind upon it would counterbalance the effect of the travel of the centre of pressure on the main surfaces. Thus changes in the direction and velocity of the wind would have little disturbing effect, and the operator would be required to attend only to the steering of the machine, which was to be effected by curving the forward surface up or down. The lateral equilibrium and the steering to right or left was to be attained by a peculiar torsion of the main surfaces which was equivalent to presenting one end of the wings at a greater angle than the other. In the main frame a few changes were also made in the details of construction and trussing employed by Mr Chanute. The most important of these were: (1) The moving of the forward main crosspiece of the frame to the extreme front edge; (2) the encasing in the cloth of all crosspieces and ribs of the surfaces; (3) a rearrangement of the wires used in trussing the two surfaces together, which rendered it possible to tighten all the wires by simply shortening two of them.' The brothers intended originally to get 200 square feet of supporting surface for their glider, but the impossibility of obtaining suitable material compelled them to reduce the area to 165 square feet, which, by the Lilienthal tables, admitted of support in a wind of about twenty-one miles an hour at an angle of three degrees. With this glider they went in the summer of I 1900 to the little settlement of Kitty Hawk, North Carolina, situated on the strip of land dividing Albemarle Sound from the Atlantic. Here they reckoned on obtaining steady wind, and here, on the day that they completed the machine, they took it out for trial as a kite with the wind blowing at between twenty-five and thirty miles an hour. They found that in order to support a man on it the glider required an angle nearer twenty degrees than three, and even with the wind at thirty miles an hour they could not get down to the planned angle of three degrees. 'Later, when the wind was too light to support the machine with a man on it, they tested it as a kite, working the rudders by cords. Although they obtained satisfactory results in this way they realised fully that actual gliding experience was necessary before the tests could be considered practical. A series of actual measurements of lift and drift of the machine gave astonishing results. 'It appeared that the total horizontal pull of the machine, while sustaining a weight of 52 lbs., was only 8.5 lbs., which was less than had been previously estimated for head resistance of the framing alone. Making allowance for the weight carried, it appeared that the head resistance of the framing was but little more than fifty per cent of the amount which Mr Chanute had estimated as the head resistance of the framing of his machine. On the other hand, it appeared sadly deficient in lifting power as compared with the calculated lift of curved surfaces of its size... we decided to arrange our machine for the following year so that the depth of curvature of its surfaces could be varied at will, and its covering air-proofed.' After these experiments the brothers decided to turn to practical gliding, for which they moved four miles to the south, to the Kill Devil sandhills, the principal of which is slightly over a hundred feet in height, with an inclination of nearly ten degrees on its main north-western slope. On the day after their arrival they made about a dozen glides, in which, although the landings were made at a speed of more than twenty miles an hour, no injury was sustained either by the machine or by the operator. 'The slope of the hill was 9.5 degrees, or a drop of one foot in six. We found that after attaining a speed of about twenty-five to thirty miles with reference to the wind, or ten to fifteen miles over the ground, the machine not only glided parallel to the slope of the hill, but greatly increased its speed, thus indicating its ability to glide on a somewhat less angle than 9.5 degrees, when we should feel it safe to rise higher from the surface. The control of the machine proved even better than we had dared to expect, responding quickly to the slightest motion of the rudder. With these glides our experiments for the year 1900 closed. Although the hours and hours of practice we had hoped to obtain finally dwindled down to about two minutes, we were very much pleased with the general results of the trip, for, setting out as we did with almost revolutionary theories on many points and an entirely untried form of machine, we considered it quite a point to be able to return without having our pet theories completely knocked on the head by the hard logic of experience, and our own brains dashed out in the bargain. Everything seemed to us to confirm the correctness of our original opinions: (1) That practice is the key to the secret of flying; (2) that it is practicable to assume the horizontal position; (3) that a smaller surface set at a negative angle in front of the main bearing surfaces, or wings, will largely counteract the effect of the fore and aft travel of the centre of pressure; (4) that steering up and down can be attained with a rudder without moving the position of the operator's body; (5) that twisting the wings so as to present their ends to the wind at different angles is a more prompt and efficient way of maintaining lateral equilibrium than shifting the body of the operator.' For the gliding experiments of 1901 it was decided to retain the form of the 1900 glider, but to increase the area to 308 square feet, which, the brothers calculated, would support itself and its operator in a wind of seventeen miles an hour with an angle of incidence of three degrees. Camp was formed at Kitty Hawk in the middle of July, and on July 27th the machine was completed and tried for the first time in a wind of about fourteen miles an hour. The first attempt resulted in landing after a glide of only a few yards, indicating that the centre of gravity was too far in front of the centre of pressure. By shifting his position farther and farther back the operator finally achieved an undulating flight of a little over 300 feet, but to obtain this success he had to use full power of the rudder to prevent both stalling and nose-diving. With the 1900 machine one-fourth of the rudder action had been necessary for far better control. Practically all glides gave the same result, and in one the machine rose higher and higher until it lost all headway. 'This was the position from which Lilienthal had always found difficulty in extricating himself, as his machine then, in spite of his greatest exertions, manifested a tendency to dive downward almost vertically and strike the ground head on with frightful velocity. In this case a warning cry from the ground caused the operator to turn the rudder to its full extent and also to move his body slightly forward. The machine then settled slowly to the ground, maintaining its horizontal position almost perfectly, and landed without any injury at all. This was very encouraging, as it showed that one of the very greatest dangers in machines with horizontal tails had been overcome by the use of the front rudder. Several glides later the same experience was repeated with the same result. In the latter case the machine had even commenced to move backward, but was nevertheless brought safely to the ground in a horizontal position. On the whole this day's experiments were encouraging, for while the action of the rudder did not seem at all like that of our 1900 machine, yet we had escaped without difficulty from positions which had proved very dangerous to preceding experimenters, and after less than one minute's actual practice had made a glide of more than 300 feet, at an angle of descent of ten degrees, and with a machine nearly twice as large as had previously been considered safe. The trouble with its control, which has been mentioned, we believed could be corrected when we should have located its cause.' It was finally ascertained that the defect could be remedied by trussing down the ribs of the whole machine so as to reduce the depth of curvature. When this had been done gliding was resumed, and after a few trials glides of 366 and 389 feet were made with prompt response on the part of the machine, even to small movements of the rudder. The rest of the story of the gliding experiments of 1901 cannot be better told than in Wilbur Wright's own words, as uttered by him in the lecture from which the foregoing excerpts have been made. 'The machine, with its new curvature, never failed to respond promptly to even small movements of the rudder. The operator could cause it to almost skim the ground, following the undulations of its surface, or he could cause it to sail out almost on a level with the starting point, and, passing high above the foot of the hill, gradually settle down to the ground. The wind on this day was blowing eleven to fourteen miles per hour. The next day, the conditions being favourable, the machine was again taken out for trial. This time the velocity of the wind was eighteen to twenty-two miles per hour. At first we felt some doubt as to the safety of attempting free flight in so strong a wind, with a machine of over 300 square feet and a practice of less than five minutes spent in actual flight. But after several preliminary experiments we decided to try a glide. The control of the machine seemed so good that we then felt no apprehension in sailing boldly forth. And thereafter we made glide after glide, sometimes following the ground closely and sometimes sailing high in the air. Mr Chanute had his camera with him and took pictures of some of these glides, several of which are among those shown. 'We made glides on subsequent days, whenever the conditions were favourable. The highest wind thus experimented in was a little over twelve metres per second--nearly twenty-seven miles per hour. It had been our intention when building the machine to do the larger part of the experimenting in the following manner:--When the wind blew seventeen miles an hour, or more, we would attach a rope to the machine and let it rise as a kite with the operator upon it. When it should reach a proper height the operator would cast off the rope and glide down to the ground just as from the top of a hill. In this way we would be saved the trouble of carrying the machine uphill after each glide, and could make at least ten glides in the time required for one in the other way. But when we came to try it, we found that a wind of seventeen miles, as measured by Richards' anemometer, instead of sustaining the machine with its operator, a total weight of 240 lbs., at an angle of incidence of three degrees, in reality would not sustain the machine alone--100 lbs.--at this angle. Its lifting capacity seemed scarcely one third of the calculated amount. In order to make sure that this was not due to the porosity of the cloth, we constructed two small experimental surfaces of equal size, one of which was air-proofed and the other left in its natural state; but we could detect no difference in their lifting powers. For a time we were led to suspect that the lift of curved surfaces very little exceeded that of planes of the same size, but further investigation and experiment led to the opinion that (1) the anemometer used by us over-recorded the true velocity of the wind by nearly 15 per cent; (2) that the well-known Smeaton co-efficient of.005 V squared for the wind pressure at 90 degrees is probably too great by at least 20 per cent; (3) that Lilienthal's estimate that the pressure on a curved surface having an angle of incidence of 3 degrees equals.545 of the pressure at go degrees is too large, being nearly 50 per cent greater than very recent experiments of our own with a pressure testing-machine indicate; (4) that the superposition of the surfaces somewhat reduced the lift per square foot, as compared with a single surface of equal area. 'In gliding experiments, however, the amount of lift is of less relative importance than the ratio of lift to drift, as this alone decides the angle of gliding descent. In a plane the pressure is always perpendicular to the surface, and the ratio of lift to drift is therefore the same as that of the cosine to the sine of the angle of incidence. But in curved surfaces a very remarkable situation is found. The pressure, instead of being uniformly normal to the chord of the arc, is usually inclined considerably in front of the perpendicular. The result is that the lift is greater and the drift less than if the pressure were normal. Lilienthal was the first to discover this exceedingly important fact, which is fully set forth in his book, Bird Flight the Basis of the Flying Art, but owing to some errors in the methods he used in making measurements, question was raised by other investigators not only as to the accuracy of his figures, but even as to the existence of any tangential force at all. Our experiments confirm the existence of this force, though our measurements differ considerably from those of Lilienthal. While at Kitty Hawk we spent much time in measuring the horizontal pressure on our unloaded machine at various angles of incidence. We found that at 13 degrees the horizontal pressure was about 23 lbs. This included not only the drift proper, or horizontal component of the pressure on the side of the surface, but also the head resistance of the framing as well. The weight of the machine at the time of this test was about 108 lbs. Now, if the pressure had been normal to the chord of the surface, the drift proper would have been to the lift (108 lbs.) as the sine of 13 degrees is to the cosine of 13 degrees, or.22 X 108/.97 = 24+ lbs.; but this slightly exceeds the total pull of 23 pounds on our scales. Therefore it is evident that the average pressure on the surface, instead of being normal to the chord, was so far inclined toward the front that all the head resistance of framing and wires used in the construction was more than overcome. In a wind of fourteen miles per hour resistance is by no means a negligible factor, so that tangential is evidently a force of considerable value. In a higher wind, which sustained the machine at an angle of 10 degrees the pull on the scales was 18 lbs. With the pressure normal to the chord the drift proper would have been 17 X 98/.98. The travel of the centre of pressure made it necessary to put sand on the front rudder to bring the centres of gravity and pressure into coincidence, consequently the weight of the machine varied from 98 lbs. to 108 lbs. in the different tests= 17 lbs., so that, although the higher wind velocity must have caused an increase in the head resistance, the tangential force still came within 1 lb. of overcoming it. After our return from Kitty Hawk we began a series of experiments to accurately determine the amount and direction of the pressure produced on curved surfaces when acted upon by winds at the various angles from zero to 90 degrees. These experiments are not yet concluded, but in general they support Lilienthal in the claim that the curves give pressures more favourable in amount and direction than planes; but we find marked differences in the exact values, especially at angles below 10 degrees. We were unable to obtain direct measurements of the horizontal pressures of the machine with the operator on board, but by comparing the distance travelled with the vertical fall, it was easily calculated that at a speed of 24 miles per hour the total horizontal resistances of our machine, when bearing the operator, amounted to 40 lbs., which is equivalent to about 2 1/3 horse-power. It must not be supposed, however, that a motor developing this power would be sufficient to drive a man-bearing machine. The extra weight of the motor would require either a larger machine, higher speed, or a greater angle of incidence in order to support it, and therefore more power. It is probable, however, that an engine of 6 horse-power, weighing 100 lbs. would answer the purpose. Such an engine is entirely practicable. Indeed, working motors of one-half this weight per horse-power (9 lbs. per horse-power) have been constructed by several different builders. Increasing the speed of our machine from 24 to 33 miles per hour reduced the total horizontal pressure from 40 to about 35 lbs. This was quite an advantage in gliding, as it made it possible to sail about 15 per cent farther with a given drop. However, it would be of little or no advantage in reducing the size of the motor in a power-driven machine, because the lessened thrust would be counterbalanced by the increased speed per minute. Some years ago Professor Langley called attention to the great economy of thrust which might be obtained by using very high speeds, and from this many were led to suppose that high speed was essential to success in a motor-driven machine. But the economy to which Professor Langley called attention was in foot pounds per mile of travel, not in foot pounds per minute. It is the foot pounds per minute that fixes the size of the motor. The probability is that the first flying machines will have a relatively low speed, perhaps not much exceeding 20 miles per hour, but the problem of increasing the speed will be much simpler in some respects than that of increasing the speed of a steamboat; for, whereas in the latter case the size of the engine must increase as the cube of the speed, in the flying machine, until extremely high speeds are reached, the capacity of the motor increases in less than simple ratio; and there is even a decrease in the fuel per mile of travel. In other words, to double the speed of a steamship (and the same is true of the balloon type of airship) eight times the engine and boiler capacity would be required, and four times the fuel consumption per mile of travel: while a flying machine would require engines of less than double the size, and there would be an actual decrease in the fuel consumption per mile of travel. But looking at the matter conversely, the great disadvantage of the flying machine is apparent; for in the latter no flight at all is possible unless the proportion of horse-power to flying capacity is very high; but on the other hand a steamship is a mechanical success if its ratio of horse-power to tonnage is insignificant. A flying machine that would fly at a speed of 50 miles per hour with engines of 1,000 horse-power would not be upheld by its wings at all at a speed of less than 25 miles an hour, and nothing less than 500 horse-power could drive it at this speed. But a boat which could make 40 miles an hour with engines of 1,000 horse-power would still move 4 miles an hour even if the engines were reduced to 1 horse-power. The problems of land and water travel were solved in the nineteenth century, because it was possible to begin with small achievements, and gradually work up to our present success. The flying problem was left over to the twentieth century, because in this case the art must be highly developed before any flight of any considerable duration at all can be obtained. 'However, there is another way of flying which requires no artificial motor, and many workers believe that success will come first by this road. I refer to the soaring flight, by which the machine is permanently sustained in the air by the same means that are employed by soaring birds. They spread their wings to the wind, and sail by the hour, with no perceptible exertion beyond that required to balance and steer themselves. What sustains them is not definitely known, though it is almost certain that it is a rising current of air. But whether it be a rising current or something else, it is as well able to support a flying machine as a bird, if man once learns the art of utilising it. In gliding experiments it has long been known that the rate of vertical descent is very much retarded, and the duration of the flight greatly prolonged, if a strong wind blows UP the face of the hill parallel to its surface. Our machine, when gliding in still air, has a rate of vertical descent of nearly 6 feet per second, while in a wind blowing 26 miles per hour up a steep hill we made glides in which the rate of descent was less than 2 feet per second. And during the larger part of this time, while the machine remained exactly in the rising current, THERE WAS NO DESCENT AT ALL, BUT EVEN A SLIGHT RISE. If the operator had had sufficient skill to keep himself from passing beyond the rising current he would have been sustained indefinitely at a higher point than that from which he started. The illustration shows one of these very slow glides at a time when the machine was practically at a standstill. The failure to advance more rapidly caused the photographer some trouble in aiming, as you will perceive. In looking at this picture you will readily understand that the excitement of gliding experiments does not entirely cease with the breaking up of camp. In the photographic dark-room at home we pass moments of as thrilling interest as any in the field, when the image begins to appear on the plate and it is yet an open question whether we have a picture of a flying machine or merely a patch of open sky. These slow glides in rising current probably hold out greater hope of extensive practice than any other method within man's reach, but they have the disadvantage of requiring rather strong winds or very large supporting surfaces. However, when gliding operators have attained greater skill, they can with comparative safety maintain themselves in the air for hours at a time in this way, and thus by constant practice so increase their knowledge and skill that they can rise into the higher air and search out the currents which enable the soaring birds to transport themselves to any desired point by first rising in a circle and then sailing off at a descending angle. This illustration shows the machine, alone, flying in a wind of 35 miles per hour on the face of a steep hill, 100 feet high. It will be seen that the machine not only pulls upward, but also pulls forward in the direction from which the wind blows, thus overcoming both gravity and the speed of the wind. We tried the same experiment with a man on it, but found danger that the forward pull would become so strong, that the men holding the ropes would be dragged from their insecure foothold on the slope of the hill. So this form of experimenting was discontinued after four or five minutes' trial. 'In looking over our experiments of the past two years, with models and full-size machines, the following points stand out with clearness:-- '1. That the lifting power of a large machine, held stationary in a wind at a small distance from the earth, is much less than the Lilienthal table and our own laboratory experiments would lead us to expect. When the machine is moved through the air, as in gliding, the discrepancy seems much less marked. '2. That the ratio of drift to lift in well-shaped surfaces is less at angles of incidence of 5 degrees to 12 degrees than at an angle of 3 degrees. '3. That in arched surfaces the centre of pressure at 90 degrees is near the centre of the surface, but moves slowly forward as the angle becomes less, till a critical angle varying with the shape and depth of the curve is reached, after which it moves rapidly toward the rear till the angle of no lift is found. '4. That with similar conditions large surfaces may be controlled with not much greater difficulty than small ones, if the control is effected by manipulation of the surfaces themselves, rather than by a movement of the body of the operator. '5. That the head resistances of the framing can be brought to a point much below that usually estimated as necessary. '6. That tails, both vertical and horizontal, may with safety be eliminated in gliding and other flying experiments. '7. That a horizontal position of the operator's body may be assumed without excessive danger, and thus the head resistance reduced to about one-fifth that of the upright position. '8. That a pair of superposed, or tandem surfaces, has less lift in proportion to drift than either surface separately, even after making allowance for weight and head resistance of the connections.' Thus, to the end of the 1901 experiments, Wilbur Wright provided a fairly full account of what was accomplished; the record shows an amount of patient and painstaking work almost beyond belief--it was no question of making a plane and launching it, but a business of trial and error, investigation and tabulation of detail, and the rejection time after time of previously accepted theories, till the brothers must have felt the the solid earth was no longer secure, at times. Though it was Wilbur who set down this and other records of the work done, yet the actual work was so much Orville's as his brother's that no analysis could separate any set of experiments and say that Orville did this and Wilbur that--the two were inseparable. On this point Griffith Brewer remarked that 'in the arguments, if one brother took one view, the other brother took the opposite view as a matter of course, and the subject was thrashed to pieces until a mutually acceptable result remained. I have often been asked since these pioneer days, "Tell me, Brewer, who was really the originator of those two?" In reply, I used first to say, "I think it was mostly Wilbur," and later, when I came to know Orville better, I said, "The thing could not have been without Orville." Now, when asked, I have to say, "I don't know," and I feel the more I think of it that it was only the wonderful combination of these two brothers, who devoted their lives together or this common object, that made the discovery of the art of flying possible.' Beyond the 1901 experiments in gliding, the record grows more scrappy, less detailed. It appears that once power-driven flight had been achieved, the brothers were not so willing to talk as before; considering the amount of work that they put in, there could have been little time for verbal description of that work--as already remarked, their tables still stand for the designer and experimenter. The end of the 1901 experiments left both brothers somewhat discouraged, though they had accomplished more than any others. 'Having set out with absolute faith in the existing scientific data, we ere driven to doubt one thing after another, finally, after two years of experiment, we cast it all aside, and decided to rely entirely on our own investigations. Truth and error were everywhere so intimately mixed as to be indistinguishable.... We had taken up aeronautics as a sport. We reluctantly entered upon the scientific side of it.' Yet, driven thus to the more serious aspect of the work, they found in the step its own reward, for the work of itself drew them on and on, to the construction of measuring machines for the avoidance of error, and to the making of series after series of measurements, concerning which Wilbur wrote in 1908 (in the Century Magazine) that 'after making preliminary measurements on a great number of different shaped surfaces, to secure a general understanding of the subject, we began systematic measurements of standard surfaces, so varied in design as to bring out the underlying causes of differences noted in their pressures. Measurements were tabulated on nearly fifty of these at all angles from zero to 45 degrees, at intervals of 2 1/2 degrees. Measurements were also secured showing the effects on each other when surfaces are superposed, or when they follow one another. 'Some strange results were obtained. One surface, with a heavy roll at the front edge, showed the same lift for all angles from 7 1/2 to 45 degrees. This seemed so anomalous that we were almost ready to doubt our own measurements, when a simple test was suggested. A weather vane, with two planes attached to the pointer at an angle of 80 degrees with each other, was made. According to our table, such a vane would be in unstable equilibrium when pointing directly into the wind, for if by chance the wind should happen to strike one plane at 39 degrees and the other at 41 degrees, the plane with the smaller angle would have the greater pressure and the pointer would be turned still farther out of the course of the wind until the two vanes again secured equal pressures, which would be at approximately 30 and 50 degrees. But the vane performed in this very manner. Further corroboration of the tables was obtained in experiments with the new glider at Kill Devil Hill the next season. 'In September and October, 1902 nearly 1,000 gliding flights were made, several of which covered distances of over 600 feet. Some, made against a wind of 36 miles an hour, gave proof of the effectiveness of the devices for control. With this machine, in the autumn of 1903, we made a number of flights in which we remained in the air for over a minute, often soaring for a considerable time in one spot, without any descent at all. Little wonder that our unscientific assistant should think the only thing needed to keep it indefinitely in the air would be a coat of feathers to make it light!' It was at the conclusion of these experiments of 1903 that the brothers concluded they had obtained sufficient data from their thousands of glides and multitude of calculations to permit of their constructing and making trial of a power-driven machine. The first designs got out provided for a total weight of 600 lbs., which was to include the weight of the motor and the pilot; but on completion it was found that there was a surplus of power from the motor, and thus they had 150 lbs. weight to allow for strengthening wings and other parts. They came up against the problem to which Riach has since devoted so much attention, that of propeller design. 'We had thought of getting the theory of the screw-propeller from the marine engineers, and then, by applying our table of air-pressures to their formulae, of designing air-propellers suitable for our uses. But, so far as we could learn, the marine engineers possessed only empirical formulae, and the exact action of the screw propeller, after a century of use, was still very obscure. As we were not in a position to undertake a long series of practical experiments to discover a propeller suitable for our machine, it seemed necessary to obtain such a thorough understanding of the theory of its reactions as would enable us to design them from calculation alone. What at first seemed a simple problem became more complex the longer we studied it. With the machine moving forward, the air flying backward, the propellers turning sidewise, and nothing standing still, it seemed impossible to find a starting point from which to trace the various simultaneous reactions. Contemplation of it was confusing. After long arguments we often found ourselves in the ludicrous position of each having been converted to the other's side, with no more agreement than when the discussion began. 'It was not till several months had passed, and every phase of the problem had been thrashed over and over, that the various reactions began to untangle themselves. When once a clear understanding had been obtained there was no difficulty in designing a suitable propeller, with proper diameter, pitch, and area of blade, to meet the requirements of the flier. High efficiency in a screw-propeller is not dependent upon any particular or peculiar shape, and there is no such thing as a "best" screw. A propeller giving a high dynamic efficiency when used upon one machine may be almost worthless when used upon another. The propeller should in every case be designed to meet the particular conditions of the machine to which it is to be applied. Our first propellers, built entirely from calculation, gave in useful work 66 per cent of the power expended. This was about one-third more than had been secured by Maxim or Langley.' Langley had made his last attempt with the 'aerodrome,' and his splendid failure but a few days before the brothers made their first attempt at power-driven aeroplane flight. On December 17th, 1903, the machine was taken out; in addition to Wilbur and Orville Wright, there were present five spectators: Mr A. D. Etheridge, of the Kill Devil life-saving station; Mr W. S.Dough, Mr W. C. Brinkley, of Manteo; Mr John Ward, of Naghead, and Mr John T. Daniels.[*] A general invitation had been given to practically all the residents in the vicinity, but the Kill Devil district is a cold area in December, and history had recorded so many experiments in which machines had failed to leave the ground that between temperature and scepticism only these five risked a waste of their time. [*] This list is as given by Wilbur Wright himself. And these five were in at the greatest conquest man had made since James Watt evolved the steam engine--perhaps even a greater conquest than that of Watt. Four flights in all were made; the first lasted only twelve seconds, 'the first in the history of the world in which a machine carrying a man had raised itself into the air by its own power in free flight, had sailed forward on a level course without reduction of speed, and had finally landed without being wrecked,' said Wilbur Wright concerning the achievement.[*] The next two flights were slightly longer, and the fourth and last of the day was one second short of the complete minute; it was made into the teeth of a 20 mile an hour wind, and the distance travelled was 852 feet. [*] Century Magazine, September, 1908. This bald statement of the day's doings is as Wilbur Wright himself has given it, and there is in truth nothing more to say; no amount of statement could add to the importance of the achievement, and no more than the bare record is necessary. The faith that had inspired the long roll of pioneers, from da Vinci onward, was justified at last. Having made their conquest, the brothers took the machine back to camp, and, as they thought, placed it in safety. Talking with the little group of spectators about the flights, they forgot about the machine, and then a sudden gust of wind struck it. Seeing that it was being overturned, all made a rush toward it to save it, and Mr Daniels, a man of large proportions, was in some way lifted off his feet, falling between the planes. The machine overturned fully, and Daniels was shaken like a die in a cup as the wind rolled the machine over and over--he came out at the end of his experience with a series of bad bruises, and no more, but the damage done to the machine by the accident was sufficient to render it useless for further experiment that season. A new machine, stronger and heavier, was constructed by the brothers, and in the spring of 1904 they began experiments again at Sims Station, eight miles to the east of Dayton, their home town. Press representatives were invited for the first trial, and about a dozen came--the whole gathering did not number more than fifty people. 'When preparations had been concluded,' Wilbur Wright wrote of this trial, 'a wind of only three or four miles an hour was blowing--insufficient for starting on so short a track--but since many had come a long way to see the machine in action, an attempt was made. To add to the other difficulty, the engine refused to work properly. The machine, after running the length of the track, slid off the end without rising into the air at all. Several of the newspaper men returned next day but were again disappointed. The engine performed badly, and after a glide of only sixty feet the machine again came to the ground. Further trial was postponed till the motor could be put in better running condition. The reporters had now, no doubt, lost confidence in the machine, though their reports, in kindness, concealed it. Later, when they heard that we were making flights of several minutes' duration, knowing that longer flights had been made with airships, and not knowing any essential difference between airships and flying machines, they were but little interested. 'We had not been flying long in 1904 before we found that the problem of equilibrium had not as yet been entirely solved. Sometimes, in making a circle, the machine would turn over sidewise despite anything the operator could do, although, under the same conditions in ordinary straight flight it could have been righted in an instant. In one flight, in 1905, while circling round a honey locust-tree at a height of about 50 feet, the machine suddenly began to turn up on one wing, and took a course toward the tree. The operator, not relishing the idea of landing in a thorn tree, attempted to reach the ground. The left wing, however, struck the tree at a height of 10 or 12 feet from the ground and carried away several branches; but the flight, which had already covered a distance of six miles, was continued to the starting point. 'The causes of these troubles--too technical for explanation here--were not entirely overcome till the end of September, 1905. The flights then rapidly increased in length, till experiments were discontinued after October 5 on account of the number of people attracted to the field. Although made on a ground open on every side, and bordered on two sides by much-travelled thoroughfares, with electric cars passing every hour, and seen by all the people living in the neighbourhood for miles around, and by several hundred others, yet these flights have been made by some newspapers the subject of a great "mystery."' Viewing their work from the financial side, the two brothers incurred but little expense in the earlier gliding experiments, and, indeed, viewed these only as recreation, limiting their expenditure to that which two men might spend on any hobby. When they had once achieved successful power-driven flight, they saw the possibilities of their work, and abandoned such other business as had engaged their energies, sinking all their capital in the development of a practical flying machine. Having, in 1905, improved their designs to such an extent that they could consider their machine a practical aeroplane, they devoted the years 1906 and 1907 to business negotiations and to the construction of new machines, resuming flying experiments in May of 1908 in order to test the ability of their machine to meet the requirements of a contract they had made with the United States Government, which required an aeroplane capable of carrying two men, together with sufficient fuel supplies for a flight of 125 miles at 40 miles per hour. Practically similar to the machine used in the experiments of 1905, the contract aeroplane was fitted with a larger motor, and provision was made for seating a passenger and also for allowing of the operator assuming a sitting position, instead of lying prone. Before leaving the work of the brothers to consider contemporary events, it may be noted that they claimed--with justice--that they were first to construct wings adjustable to different angles of incidence on the right and left side in order to control the balance of an aeroplane; the first to attain lateral balance by adjusting wing-tips to respectively different angles of incidence on the right and left sides, and the first to use a vertical vane in combination with wing-tips, adjustable to respectively different angles of incidence, in balancing and steering an aeroplane. They were first, too, to use a movable vertical tail, in combination with wings adjustable to different angles of incidence, in controlling the balance and direction of an aeroplane.[*] [*]Aeronautical Journal, No. 79. A certain Henry M. Weaver, who went to see the work of the brothers, writing in a letter which was subsequently read before the Aero Club de France records that he had a talk in 1905 with the farmer who rented the field in which the Wrights made their flights.' On October 5th (1905) he was cutting corn in the next field east, which is higher ground. When he noticed the aeroplane had started on its flight he remarked to his helper: "Well, the boys are at it again," and kept on cutting corn, at the same time keeping an eye on the great white form rushing about its course. "I just kept on shocking corn," he continued, "until I got down to the fence, and the durned thing was still going round. I thought it would never stop."' He was right. The brothers started it, and it will never stop. Mr Weaver also notes briefly the construction of the 1905 Wright flier. 'The frame was made of larch wood-from tip to tip of the wings the dimension was 40 feet. The gasoline motor--a special construction made by them--much the same, though, as the motor on the Pope-Toledo automobile--was of from 12 to 15 horse-power. The motor weighed 240 lbs. The frame was covered with ordinary muslin of good quality. No attempt was made to lighten the machine; they simply built it strong enough to stand the shocks. The structure stood on skids or runners, like a sleigh. These held the frame high enough from the ground in alighting to protect the blades of the propeller. Complete with motor, the machine weighed 925 lbs. XII. THE FIRST YEARS OF CONQUEST It is no derogation of the work accomplished by the Wright Brothers to say that they won the honour of the first power-propelled flights in a heavier-than-air machine only by a short period. In Europe, and especially in France, independent experiment was being conducted by Ferber, by Santos-Dumont, and others, while in England Cody was not far behind the other giants of those days. The history of the early years of controlled power flights is a tangle of half-records; there were no chroniclers, only workers, and much of what was done goes unrecorded perforce, since it was not set down at the time. Before passing to survey of those early years, let it be set down that in 1907, when the Wright Brothers had proved the practicability of their machines, negotiations were entered into between the brothers and the British War office. On April 12th 1907, the apostle of military stagnation, Haldane, then War Minister, put an end to the negotiations by declaring that 'the War office is not disposed to enter into relations at present with any manufacturer of aeroplanes' The state of the British air service in 1914 at the outbreak of hostilities, is eloquent regarding the pursuance of the policy which Haldane initiated. 'If I talked a lot,' said Wilbur Wright once, 'I should be like the parrot, which is the bird that speaks most and flies least.' That attitude is emblematic of the majority of the early fliers, and because of it the record of their achievements is incomplete to-day. Ferber, for instance, has left little from which to state what he did, and that little is scattered through various periodicals, scrappily enough. A French army officer, Captain Ferber was experimenting with monoplane and biplane gliders at the beginning of the century-his work was contemporary with that of the Wrights. He corresponded both with Chanute and with the Wrights, and in the end he was commissioned by the French Ministry of War to undertake the journey to America in order to negotiate with the Wright Brothers concerning French rights in the patents they had acquired, and to study their work at first hand. Ferber's experiments in gliding began in 1899 at the Military School at Fountainebleau, with a canvas glider of some 80 square feet supporting surface, and weighing 65 lbs. Two years later he constructed a larger and more satisfactory machine, with which he made numerous excellent glides. Later, he constructed an apparatus which suspended a plane from a long arm which swung on a tower, in order that experiments might be carried out without risk to the experimenter, and it was not until 1905 that he attempted power-driven free flight. He took up the Voisin design of biplane for his power-driven flights, and virtually devoted all his energies to the study of aeronautics. His book, Aviation, its Dawn and Development, is a work of scientific value--unlike many of his contemporaries, Ferber brought to the study of the problems of flight a trained mind, and he was concerned equally with the theoretical problems of aeronautics and the practical aspects of the subject. After Bleriot's successful cross-Channel flight, it was proposed to offer a prize of L1,000 for the feat which C. S. Rolls subsequently accomplished (starting from the English side of the Channel), a flight from Boulogne to Dover and back; in place of this, however, an aviation week at Boulogne was organised, but, although numerous aviators were invited to compete, the condition of the flying grounds was such that no competitions took place. Ferber was virtually the only one to do any flying at Boulogne, and at the outset he had his first accident; after what was for those days a good flight, he made a series of circles with his machine, when it suddenly struck the ground, being partially wrecked. Repairs were carried out, and Ferber resumed his exhibition flights, carrying on up to Wednesday, September 22nd, 1909. On that day he remained in the air for half an hour, and, as he was about to land, the machine struck a mound of earth and overturned, pinning Ferber under the weight of the motor. After being extricated, Ferber seemed to show little concern at the accident, but in a few minutes he complained of great pain, when he was conveyed to the ambulance shed on the ground. 'I was foolish,' he told those who were with him there. 'I was flying too low. It was my own fault and it will be a severe lesson to me. I wanted to turn round, and was only five metres from the ground.' A little after this, he got up from the couch on which he had been placed, and almost immediately collapsed, dying five minutes later. Ferber's chief contemporaries in France were Santos-Dumont, of airship fame, Henri and Maurice Farman, Hubert Latham, Ernest Archdeacon, and Delagrange. These are names that come at once to mind, as does that of Bleriot, who accomplished the second great feat of power-driven flight, but as a matter of fact the years 1903-10 are filled with a little host of investigators and experimenters, many of whom, although their names do not survive to any extent, are but a very little way behind those mentioned here in enthusiasm and devotion. Archdeacon and Gabriel Voisin, the former of whom took to heart the success achieved by the Wright Brothers, co-operated in experiments in gliding. Archdeacon constructed a glider in box-kite fashion, and Voisin experimented with it on the Seine, the glider being towed by a motorboat to attain the necessary speed. It was Archdeacon who offered a cup for the first straight flight of 200 metres, which was won by Santos-Dumont, and he also combined with Henri Deutsch de la Meurthe in giving the prize for the first circular flight of a mile, which was won by Henry Farman on January 13th, 1908. A history of the development of aviation in France in these, the strenuous years, would fill volumes in itself. Bleriot was carrying out experiments with a biplane glider on the Seine, and Robert Esnault-Pelterie was working on the lines of the Wright Brothers, bringing American practice to France. In America others besides the Wrights had wakened to the possibilities of heavier-than-air flight; Glenn Curtiss, in company with Dr Alexander Graham Bell, with J. A. D. McCurdy, and with F. W. Baldwin, a Canadian engineer, formed the Aerial Experiment Company, which built a number of aeroplanes, most famous of which were the 'June Bug,' the 'Red Wing,' and the 'White Wing.' In 1908 the 'June Bug 'won a cup presented by the Scientific American--it was the first prize offered in America in connection with aeroplane flight. Among the little group of French experimenters in these first years of practical flight, Santos-Dumont takes high rank. He built his 'No. 14 bis' aeroplane in biplane form, with two superposed main plane surfaces, and fitted it with an eight-cylinder Antoinette motor driving a two-bladed aluminium propeller, of which the blades were 6 feet only from tip to tip. The total lift surface of 860 square feet was given with a wing-span of a little under 40 feet, and the weight of the complete machine was 353 lbs., of which the engine weighed 158 lbs. In July of 1906 Santos-Dumont flew a distance of a few yards in this machine, but damaged it in striking the ground; on October 23rd of the same year he made a flight of nearly 200 feet--which might have been longer, but that he feared a crowd in front of the aeroplane and cut off his ignition. This may be regarded as the first effective flight in Europe, and by it Santos-Dumont takes his place as one of the chief--if not the chief--of the pioneers of the first years of practical flight, so far as Europe is concerned. Meanwhile, the Voisin Brothers, who in 1904 made cellular kites for Archdeacon to test by towing on the Seine from a motor launch, obtained data for the construction of the aeroplane which Delagrange and Henry Farman were to use later. The Voisin was a biplane, constructed with due regard to the designs of Langley, Lilienthal, and other earlier experimenters--both the Voisins and M. Colliex, their engineer, studied Lilienthal pretty exhaustively in getting out their design, though their own researches were very thorough as well. The weight of this Voisin biplane was about 1,450 lbs., and its maximum speed was some 38 to 40 miles per hour, the total supporting surface being about 535 square feet. It differed from the Wright design in the possession of a tail-piece, a characteristic which marked all the French school of early design as in opposition to the American. The Wright machine got its longitudinal stability by means of the main planes and the elevating planes, while the Voisin type added a third factor of stability in its sailplanes. Further, the Voisins fitted their biplane with a wheeled undercarriage, while the Wright machine, being fitted only with runners, demanded a launching rail for starting. Whether a machine should be tailless or tailed was for some long time matter for acute controversy, which in the end was settled by the fitting of a tail to the Wright machines-France won the dispute by the concession. Henry Farman, who began his flying career with a Voisin machine, evolved from it the aeroplane which bore his name, following the main lines of the Voisin type fairly closely, but making alterations in the controls, and in the design of the undercarriage, which was somewhat elaborated, even to the inclusion of shock absorbers. The seven-cylinder 50 horse-power Gnome rotary engine was fitted to the Farman machine--the Voisins had fitted an eight-cylinder Antoinette, giving 50 horse-power at 1,100 revolutions per minute, with direct drive to the propeller. Farman reduced the weight of the machine from the 1,450 lbs. of the Voisins to some 1,010 lbs. or thereabouts, and the supporting area to 450 square feet. This machine won its chief fame with Paulhan as pilot in the famous London to Manchester flight--it is to be remarked, too, that Farman himself was the first man in Europe to accomplish a flight of a mile. Other notable designs of these early days were the 'R.E.P.', Esnault Pelterie's machine, and the Curtiss-Herring biplane. Of these Esnault Pelterie's was a monoplane, designed in that form since Esnault Pelterie had found by experiment that the wire used in bracing offers far more resistance to the air than its dimensions would seem to warrant. He built the wings of sufficient strength to stand the strain of flight without bracing wires, and dependent only for their support on the points of attachment to the body of the machine; for the rest, it carried its propeller in front of the planes, and both horizontal and vertical rudders at the stern--a distinct departure from the Wright and similar types. One wheel only was fixed under the body where the undercarriage exists on a normal design, but light wheels were fixed, one at the extremity of each wing, and there was also a wheel under the tail portion of the machine. A single lever actuated all the controls for steering. With a supporting surface of 150 square feet the machine weighed 946 lbs., about 6.4 lbs. per square foot of lifting surface. The Curtiss biplane, as flown by Glenn Curtiss at the Rheims meeting, was built with a bamboo framework, stayed by means of very fine steel-stranded cables. A--then--novel feature of the machine was the moving of the ailerons by the pilot leaning to one side or the other in his seat, a light, tubular arm-rest being pressed by his body when he leaned to one side or the other, and thus operating the movement of the ailerons employed for tilting the plane when turning. A steering-wheel fitted immediately in front of the pilot's seat served to operate a rear steering-rudder when the wheel was turned in either direction, while pulling back the wheel altered the inclination of the front elevating planes, and so gave lifting or depressing control of the plane. This machine ran on three wheels before leaving the ground, a central undercarriage wheel being fitted in front, with two more in line with a right angle line drawn through the centre of the engine crank at the rear end of the crank-case. The engine was a 35 horsepower Vee design, water cooled, with overhead inlet and exhaust valves, and Bosch high-tension magneto ignition. The total weight of the plane in flying order was about 700 lbs. As great a figure in the early days as either Ferber or Santos-Dumont was Louis Bleriot, who, as early as 1900 built a flapping-wing model, this before ever he came to experimenting with the Voisin biplane type of glider on the Seine. Up to 1906 he had built four biplanes of his own design, and in March of 1907 he built his first monoplane, to wreck it only a few days after completion in an accident from which he had a fortunate escape. His next machine was a double monoplane, designed after Langley's precept, to a certain extent, and this was totally wrecked in September of 1907. His seventh machine, a monoplane, was built within a month of this accident, and with this he had a number of mishaps, also achieving some good flights, including one in which he made a turn. It was wrecked in December of 1907, whereupon he built another monoplane on which, on July 6th, 1908, Bleriot made a flight lasting eight and a half minutes. In October of that year he flew the machine from Toury to Artenay and returned on it--this was just a day after Farman's first cross-country flight--but, trying to repeat the success five days later, Bleriot collided with a tree in a fog and wrecked the machine past repair. Thereupon he set about building his eleventh machine, with which he was to achieve the first flight across the English channel. Henry Farman, to whom reference has already been made, was engaged with his two brothers, Maurice and Richard, in the motor-car business, and turned to active interest in flying in 1907, when the Voisin firm built his first biplane on the box-kite principle. In July of 1908 he won a prize of L400 for a flight of thirteen miles, previously having completed the first kilometre flown in Europe with a passenger, the said passenger being Ernest Archdeaon. In September of 1908 Farman put up a speed record of forty miles an hour in a flight lasting forty minutes. Santos-Dumont produced the famous 'Demoiselle' monoplane early in 1909, a tiny machine in which the pilot had his seat in a sort of miniature cage under the main plane. It was a very fast, light little machine but was difficult to fly, and owing to its small wingspread was unable to glide at a reasonably safe angle. There has probably never been a cheaper flying machine to build than the 'Demoiselle,' which could be so upset as to seem completely wrecked, and then repaired ready for further flight by a couple of hours' work. Santos-Dumont retained no patent in the design, but gave it out freely to any one who chose to build 'Demoiselles'; the vogue of the pattern was brief, owing to the difficulty of piloting the machine. These were the years of records, broken almost as soon as made. There was Farman's mile, there was the flight of the Comte de Lambert over the Eiffel Tower, Latham's flight at Blackpool in a high wind, the Rheims records, and then Henry Farman's flight of four hours later in 1909, Orville Wright's height record of 1,640 feet, and Delagrange's speed record of 49.9 miles per hour. The coming to fame of the Gnome rotary engine helped in the making of these records to a very great extent, for in this engine was a prime mover which gave the reliability that aeroplane builders and pilots had been searching for, but vainly. The Wrights and Glenn Curtiss, of course, had their own designs of engine, but the Gnome, in spite of its lack of economy in fuel and oil, and its high cost, soon came to be regarded as the best power plant for flight. Delagrange, one of the very good pilots of the early days, provided a curious insight to the way in which flying was regarded, at the opening of the Juvisy aero aerodrome in May of 1909. A huge crowd had gathered for the first day's flying, and nine machines were announced to appear, but only three were brought out. Delagrange made what was considered an indifferent little flight, and another pilot, one De Bischoff, attempted to rise, but could not get his machine off the ground. Thereupon the crowd of 30,000 people lost their tempers, broke down the barriers surrounding the flying course, and hissed the officials, who were quite unable to maintain order. Delagrange, however, saved the situation by making a circuit of the course at a height of thirty feet from the ground, which won him rounds of cheering and restored the crowd to good humour. Possibly the smash achieved by Rougier, the famous racing motorist, who crashed his Voisin biplane after Delagrange had made his circuit, completed the enjoyment of the spectators. Delagrange, flying at Argentan in June of 1909, made a flight of four kilometres at a height of sixty feet; for those days this was a noteworthy performance. Contemporary with this was Hubert Latham's flight of an hour and seven minutes on an Antoinette monoplane; this won the adjective 'magnificent' from contemporary recorders of aviation. Viewing the work of the little group of French experimenters, it is, at this length of time from their exploits, difficult to see why they carried the art as far as they did. There was in it little of satisfaction, a certain measure of fame, and practically no profit--the giants of those days got very little for their pains. Delagrange's experience at the opening of the Juvisy ground was symptomatic of the way in which flight was regarded by the great mass of people--it was a sport, and nothing more, but a sport without the dividends attaching to professional football or horse-racing. For a brief period, after the Rheims meeting, there was a golden harvest to be reaped by the best of the pilots. Henry Farman asked L2,000 for a week's exhibition flying in England, and Paulhan asked half that sum, but a rapid increase in the number of capable pilots, together with the fact that most flying meetings were financial failures, owing to great expense in organisation and the doubtful factor of the weather, killed this goose before many golden eggs had been gathered in by the star aviators. Besides, as height and distance records were broken one after another, it became less and less necessary to pay for entrance to an aerodrome in order to see a flight--the thing grew too big for a mere sports ground. Long before Rheims and the meeting there, aviation had grown too big for the chronicling of every individual effort. In that period of the first days of conquest of the air, so much was done by so many whose names are now half-forgotten that it is possible only to pick out the great figures and make brief reference to their achievements and the machines with which they accomplished so much, pausing to note such epoch-making events as the London-Manchester flight, Bleriot's Channel crossing, and the Rheims meeting itself, and then passing on beyond the days of individual records to the time when the machine began to dominate the man. This latter because, in the early days, it was heroism to trust life to the planes that were turned out--the 'Demoiselle' and the Antoinette machine that Latham used in his attempt to fly the Channel are good examples of the flimsiness of early types--while in the later period, that of the war and subsequently, the heroism turned itself in a different--and nobler-direction. Design became standardised, though not perfected. The domination of the machine may best be expressed by contrasting the way in which machines came to be regarded as compared with the men who flew them: up to 1909, flying enthusiasts talked of Farman, of Bleriot, of Paulhan, Curtiss, and of other men; later, they began to talk of the Voisin, the Deperdussin, and even to the Fokker, the Avro, and the Bristol type. With the standardising of the machine, the days of the giants came to an end. XIII. FIRST FLIERS IN ENGLAND Certain experiments made in England by Mr Phillips seem to have come near robbing the Wright Brothers of the honour of the first flight; notes made by Colonel J. D. Fullerton on the Phillips flying machine show that in 1893 the first machine was built with a length of 25 feet, breadth of 22 feet, and height of 11 feet, the total weight, including a 72 lb. load, being 420 lbs. The machine was fitted with some fifty wood slats, in place of the single supporting surface of the monoplane or two superposed surfaces of the biplane, these slats being fixed in a steel frame so that the whole machine rather resembled a Venetian blind. A steam engine giving about 9 horse-power provided the motive power for the six-foot diameter propeller which drove the machine. As it was not possible to put a passenger in control as pilot, the machine was attached to a central post by wire guys and run round a circle 100 feet in diameter, the track consisting of wooden planking 4 feet wide. Pressure of air under the slats caused the machine to rise some two or three feet above the track when sufficient velocity had been attained, and the best trials were made on June 19th 1893, when at a speed of 40 miles an hour, with a total load of 385 lbs., all the wheels were off the ground for a distance of 2,000 feet. In 1904 a full-sized machine was constructed by Mr Phillips, with a total weight, including that of the pilot, of 600 lbs. The machine was designed to lift when it had attained a velocity of 50 feet per second, the motor fitted giving 22 horse-power. On trial, however, the longitudinal equilibrium was found to be defective, and a further design was got out, the third machine being completed in 1907. In this the wood slats were held in four parallel container frames, the weight of the machine, excluding the pilot, being 500 lbs. A motor similar to that used in the 1904 machine was fitted, and the machine was designed to lift at a velocity of about 30 miles an hour, a seven-foot propeller doing the driving. Mr Phillips tried out this machine in a field about 400 yards across. 'The machine was started close to the hedge, and rose from the ground when about 200 yards had been covered. When the machine touched the ground again, about which there could be no doubt, owing to the terrific jolting, it did not run many yards. When it came to rest I was about ten yards from the boundary. Of course, I stopped the engine before I commenced to descend.'[*] [*] Aeronautical Journal, July, 1908. S. F. Cody, an American by birth, aroused the attention not only of the British public, but of the War office and Admiralty as well, as early as 1905 with his man-lifting kites. In that year a height of 1,600 feet was reached by one of these box-kites, carrying a man, and later in the same year one Sapper Moreton, of the Balloon Section of the Royal Engineers (the parent of the Royal Flying Corps) remained for an hour at an altitude of 2,600 feet. Following on the success of these kites, Cody constructed an aeroplane which he designated a 'power kite,' which was in reality a biplane that made the first flight in Great Britain. Speaking before the Aeronautical Society in 1908, Cody said that 'I have accomplished one thing that I hoped for very much, that is, to be the first man to fly in Great Britain.... I made a machine that left the ground the first time out; not high, possibly five or six inches only. I might have gone higher if I wished. I made some five flights in all, and the last flight came to grief.... On the morning of the accident I went out after adjusting my propellers at 8 feet pitch running at 600 (revolutions per minute). I think that I flew at about twenty-eight miles per hour. I had 50 horsepower motor power in the engine. A bunch of trees, a flat common above these trees, and from this flat there is a slope goes down... to another clump of trees. Now, these clumps of trees are a quarter of a mile apart or thereabouts.... I was accused of doing nothing but jumping with my machine, so I got a bit agitated and went to fly. I went out this morning with an easterly wind, and left the ground at the bottom of the hill and struck the ground at the top, a distance of 74 yards. That proved beyond a doubt that the machine would fly--it flew uphill. That was the most talented flight the machine did, in my opinion. Now, I turned round at the top and started the machine and left the ground--remember, a ten mile wind was blowing at the time. Then, 60 yards from where the men let go, the machine went off in this direction (demonstrating)--I make a line now where I hoped to land--to cut these trees off at that side and land right off in here. I got here somewhat excited, and started down and saw these trees right in front of me. I did not want to smash my head rudder to pieces, so I raised it again and went up. I got one wing direct over that clump of trees, the right wing over the trees, the left wing free; the wind, blowing with me, had to lift over these trees. So I consequently got a false lift on the right side and no lift on the left side. Being only about 8 feet from the tree tops, that turned my machine up like that (demonstrating). This end struck the ground shortly after I had passed the trees. I pulled the steering handle over as far as I could. Then I faced another bunch of trees right in front of me. Trying to avoid this second bunch of trees I turned the rudder, and turned it rather sharp. That side of the machine struck, and it crumpled up like so much tissue paper, and the machine spun round and struck the ground that way on, and the framework was considerably wrecked. Now, I want to advise all aviators not to try to fly with the wind and to cross over any big clump of earth or any obstacle of any description unless they go square over the top of it, because the lift is enormous crossing over anything like that, and in coming the other way against the wind it would be the same thing when you arrive at the windward side of the obstacle. That is a point I did not think of, and had I thought of it I would have been more cautious.' This Cody machine was a biplane with about 40 foot span, the wings being about 7 feet in depth with about 8 feet between upper and lower wing surfaces. 'Attached to the extremities of the lower planes are two small horizontal planes or rudders, while a third small vertical plane is fixed over the centre of the upper plane.' The tail-piece and principal rudder were fitted behind the main body of the machine, and a horizontal rudder plane was rigged out in front, on two supporting arms extending from the centre of the machine. The small end-planes and the vertical plane were used in conjunction with the main rudder when turning to right or left, the inner plane being depressed on the turn, and the outer one correspondingly raised, while the vertical plane, working in conjunction, assisted in preserving stability. Two two-bladed propellers were driven by an eight-cylinder 50 horse-power Antoinette motor. With this machine Cody made his first flights over Laffan's plain, being then definitely attached to the Balloon Section of the Royal Engineers as military aviation specialist. There were many months of experiment and trial, after the accident which Cody detailed in the statement given above, and then, on May 14th, 1909, Cody took the air and made a flight of 1,200 yards with entire success. Meanwhile A. V. Roe was experimenting at Lea Marshes with a triplane of rather curious design the pilot having his seat between two sets of three superposed planes, of which the front planes could be tilted and twisted while the machine was in motion. He comes but a little way after Cody in the chronology of early British experimenters, but Cody, a born inventor, must be regarded as the pioneer of the present century so far as Britain is concerned. He was neither engineer nor trained mathematician, but he was a good rule-of-thumb mechanic and a man of pluck and perseverance; he never strove to fly on an imperfect machine, but made alteration after alteration in order to find out what was improvement and what was not, in consequence of which it was said of him that he was 'always satisfied with his alterations.' By July of 1909 he had fitted an 80 horse-power motor to his biplane, and with this he made a flight of over four miles over Laffan's Plain on July 21st. By August he was carrying passengers, the first being Colonel Capper of the R.E. Balloon Section, who flew with Cody for over two miles, and on September 8th, 1909, he made a world's record cross-country flight of over forty miles in sixty-six minutes, taking a course from Laffan's Plain over Farnborough, Rushmoor, and Fleet, and back to Laffan's Plain. He was one of the competitors in the 1909 Doncaster Aviation Meeting, and in 1910 he competed at Wolverhampton, Bournemouth, and Lanark. It was on June 7th, 1910, that he qualified for his brevet, No. 9, on the Cody biplane. He built a machine which embodied all the improvements for which he had gained experience, in 1911, a biplane with a length of 35 feet and span of 43 feet, known as the 'Cody cathedral' on account of its rather cumbrous appearance. With this, in 1911, he won the two Michelin trophies presented in England, completed the Daily Mail circuit of Britain, won the Michelin cross-country prize in 1912 and altogether, by the end of 1912, had covered more than 7,000 miles with the machine. It was fitted with a 120 horse-power Austro-Daimler engine, and was characterised by an exceptionally wide range of speed--the great wingspread gave a slow landing speed. A few of his records may be given: in 1910, flying at Laffan's Plain in his biplane, fitted with a 50-60 horsepower Green engine, on December 31st, he broke the records for distance and time by flying 185 miles, 787 yards, in 4 hours 37 minutes. On October 31st, 1911, he beat this record by flying for 5 hours 15 minutes, in which period he covered 261 miles 810 yards with a 60 horse-power Green engine fitted to his biplane. In 1912, competing in the British War office tests of military aeroplanes, he won the L5,000 offered by the War Office. This was in competition with no less than twenty-five other machines, among which were the since-famous Deperdussin, Bristol, Flanders, and Avro types, as well as the Maurice Farman and Bleriot makes of machine. Cody's remarkable speed range was demonstrated in these trials, the speeds of his machine varying between 72.4 and 48.5 miles per hour. The machine was the only one delivered for the trials by air, and during the three hours' test imposed on all competitors a maximum height of 5,000 feet was reached, the first thousand feet being achieved in three and a half minutes. During the summer of 1913 Cody put his energies into the production of a large hydro-biplane, with which he intended to win the L5,000 prize offered by the Daily Mail to the first aviator to fly round Britain on a waterplane. This machine was fitted with landing gear for its tests, and, while flying it over Laffan's Plain on August 7th, 1913, with Mr W. H. B. Evans as passenger, Cody met with the accident that cost both him and his passenger their lives. Aviation lost a great figure by his death, for his plodding, experimenting, and dogged courage not only won him the fame that came to a few of the pilots of those days, but also advanced the cause of flying very considerably and contributed not a little to the sum of knowledge in regard to design and construction. Another figure of the early days was A. V. Roe, who came from marine engineering to the motor industry and aviation in 1905. In 1906 he went out to Colorado, getting out drawings for the Davidson helicopter, and in 1907 having returned to England, he obtained highest award out of 200 entries in a model aeroplane flying competition. From the design of this model he built a full-sized machine, and made a first flight on it, fitted with a 24 horse-power Antoinette engine, in June of 1908 Later, he fitted a 9 horsepower motor-cycle engine to a triplane of his own design, and with this made a number of short flights; he got his flying brevet on a triplane with a motor of 35 horse-power, which, together with a second triplane, was entered for the Blackpool aviation meeting of 1910 but was burnt in transport to the meeting. He was responsible for the building of the first seaplane to rise from English waters, and may be counted the pioneer of the tractor type of biplane. In 1913 he built a two-seater tractor biplane with 80 horse-power engine, a machine which for some considerable time ranked as a leader of design. Together with E. V. Roe and H. V. Roe, 'A. V.' controlled the Avro works, which produced some of the most famous training machines of the war period in a modification of the original 80 horse-power tractor. The first of the series of Avro tractors to be adopted by the military authorities was the 1912 biplane, a two-seater fitted with 50 horsepower engine. It was the first tractor biplane with a closed fuselage to be used for military work, and became standard for the type. The Avro seaplane, of I 100 horse-power (a fourteen-cylinder Gnome engine was used) was taken up by the British Admiralty in 1913. It had a length of 34 feet and a wing-span of 50 feet, and was of the twin-float type. Geoffrey de Havilland, though of later rank, counts high among designers of British machines. He qualified for his brevet as late as February, 1911, on a biplane of his own construction, and became responsible for the design of the BE2, the first successful British Government biplane. On this he made a British height record of 10,500 feet over Salisbury Plain, in August of 1912, when he took up Major Sykes as passenger. In the war period he was one of the principal designers of fighting and reconnaissance machines. F. Handley Page, who started in business as an aeroplane builder in 1908, having works at Barking, was one of the principal exponents of the inherently stable machine, to which he devoted practically all his experimental work up to the outbreak of war. The experiments were made with various machines, both of monoplane and biplane type, and of these one of the best was a two-seater monoplane built in 1911, while a second was a larger machine, a biplane, built in 1913 and fitted with a 110 horse-power Anzani engine. The war period brought out the giant biplane with which the name of Handley Page is most associated, the twin-engined night-bomber being a familiar feature of the later days of the war; the four-engined bomber had hardly had a chance of proving itself under service conditions when the war came to an end. Another notable figure of the early period was 'Tommy' Sopwith, who took his flying brevet at Brooklands in November of 1910, and within four days made the British duration record of 108 miles in 3 hours 12 minutes. On December 18th, 1910, he won the Baron de Forrest prize of L4,000 for the longest flight from England to the Continent, flying from Eastchurch to Tirlemont, Belgium, in three hours, a distance of 161 miles. After two years of touring in America, he returned to England and established a flying school. In 1912 he won the first aerial Derby, and in 1913 a machine of his design, a tractor biplane, raised the British height record to 13,000 feet (June 16th, at Brooklands). First as aviator, and then as designer, Sopwith has done much useful work in aviation. These are but a few, out of a host who contributed to the development of flying in this country, for, although France may be said to have set the pace as regards development, Britain was not far behind. French experimenters received far more Government aid than did the early British aviators and designers--in the early days the two were practically synonymous, and there are many stories of the very early days at Brooklands, where, when funds ran low, the ardent spirits patched their trousers with aeroplane fabric and went on with their work with Bohemian cheeriness. Cody, altering and experimenting on Laffan's Plain, is the greatest figure of them all, but others rank, too, as giants of the early days, before the war brought full recognition of the aeroplane's potentialities. One of the first men actually to fly in England, Mr J. C. T. Moore-Brabazon, was a famous figure in the days of exhibition flying, and won his reputation mainly through being first to fly a circular mile on a machine designed and built in Great Britain and piloted by a British subject. Moore-Brabazon's earliest flights were made in France on a Voisin biplane in 1908, and he brought this machine over to England, to the Aero Club grounds at Shellness, but soon decided that he would pilot a British machine instead. An order was placed for a Short machine, and this, fitted with a 50-60 horse-power Green engine, was used for the circular mile, which won a prize of L1,000 offered by the Daily Mail, the feat being accomplished on October 30th, 1909. Five days later, Moore-Brabazon achieved the longest flight up to that time accomplished on a British-built machine, covering three and a half miles. In connection with early flying in England, it is claimed that A. V. Roe, flying 'Avro B,',' on June 8th, 1908, was actually the first man to leave the ground, this being at Brooklands, but in point of fact Cody antedated him. No record of early British fliers could be made without the name of C. S. Rolls, a son of Lord Llangattock, on June 2nd, 1910, he flew across the English Channel to France, until he was duly observed over French territory, when he returned to England without alighting. The trip was made on a Wright biplane, and was the third Channel crossing by air, Bleriot having made the first, and Jacques de Lesseps the second. Rolls was first to make the return journey in one trip. He was eventually killed through the breaking of the tail-plane of his machine in descending at a flying meeting at Bournemouth. The machine was a Wright biplane, but the design of the tail-plane--which, by the way, was an addition to the machine, and was not even sanctioned by the Wrights--appears to have been carelessly executed, and the plane itself was faulty in construction. The breakage caused the machine to overturn, killing Rolls, who was piloting it. XIV. RHEIMS, AND AFTER The foregoing brief--and necessarily incomplete--survey of the early British group of fliers has taken us far beyond some of the great events of the early days of successful flight, and it is necessary to go back to certain landmarks in the history of aviation, first of which is the great meeting at Rheims in 1909. Wilbur Wright had come to Europe, and, flying at Le Mans and Pau--it was on August 8th, 1908, that Wilbur Wright made the first of his ascents in Europe--had stimulated public interest in flying in France to a very great degree. Meanwhile, Orville Wright, flying at Fort Meyer, U.S.A., with Lieutenant Selfridge as a passenger, sustained an accident which very nearly cost him his life through the transmission gear of the motor breaking. Selfridge was killed and Orville Wright was severely injured--it was the first fatal accident with a Wright machine. Orville Wright made a flight of over an hour on September 9th, 1908, and on December 31st of that year Wilbur flew for 2 hours 19 minutes. Thus, when the Rheims meeting was organised--more notable because it was the first of its kind, there were already records waiting to be broken. The great week opened on August 22nd, there being thirty entrants, including all the most famous men among the early fliers in France. Bleriot, fresh from his Channel conquest, was there, together with Henry Farman, Paulhan, Curtiss, Latham, and the Comte de Lambert, first pupil of the Wright machine in Europe to achieve a reputation as an aviator. 'To say that this week marks an epoch in the history of the world is to state a platitude. Nevertheless, it is worth stating, and for us who are lucky enough to be at Rheims during this week there is a solid satisfaction in the idea that we are present at the making of history. In perhaps only a few years to come the competitions of this week may look pathetically small and the distances and speeds may appear paltry. Nevertheless, they are the first of their kind, and that is sufficient.' So wrote a newspaper correspondent who was present at the famous meeting, and his words may stand, being more than mere journalism; for the great flying week which opened on August 22nd, 1909, ranks as one of the great landmarks in the history of heavier-than-air flight. The day before the opening of the meeting a downpour of rain spoilt the flying ground; Sunday opened with a fairly high wind, and in a lull M. Guffroy turned out on a crimson R.E.P. monoplane, but the wheels of his undercarriage stuck in the mud and prevented him from rising in the quarter of an hour allowed to competitors to get off the ground. Bleriot, following, succeeded in covering one side of the triangular course, but then came down through grit in the carburettor. Latham, following him with thirteen as the number of his machine, experienced his usual bad luck and came to earth through engine trouble after a very short flight. Captain Ferber, who, owing to military regulations, always flew under the name of De Rue, came out next with his Voisin biplane, but failed to get off the ground; he was followed by Lefebvre on a Wright biplane, who achieved the success of the morning by rounding the course--a distance of six and a quarter miles--in nine minutes with a twenty mile an hour wind blowing. His flight finished the morning. Wind and rain kept competitors out of the air until the evening, when Latham went up, to be followed almost immediately by the Comte de Lambert. Sommer, Cockburn (the only English competitor), Delagrange, Fournier, Lefebvre, Bleriot, Bunau-Varilla, Tissandier, Paulhan, and Ferber turned out after the first two, and the excitement of the spectators at seeing so many machines in the air at one time provoked wild cheering. The only accident of the day came when Bleriot damaged his propeller in colliding with a haycock. The main results of the day were that the Comte de Lambert flew 30 kilometres in 29 minutes 2 seconds; Lefebvre made the ten-kilometre circle of the track in just a second under 9 minutes, while Tissandier did it in 9 1/4 minutes, and Paulhan reached a height of 230 feet. Small as these results seem to us now, and ridiculous as may seem enthusiasm at the sight of a few machines in the air at the same time, the Rheims Meeting remains a great event, since it proved definitely to the whole world that the conquest of the air had been achieved. Throughout the week record after record was made and broken. Thus on the Monday, Lefebvre put up a record for rounding the course and Bleriot beat it, to be beaten in turn by Glenn Curtiss on his Curtiss-Herring biplane. On that day, too, Paulhan covered 34 3/4 miles in 1 hour 6 minutes. On the next day, Paulhan on his Voisin biplane took the air with Latham, and Fournier followed, only to smash up his machine by striking an eddy of wind which turned him over several times. On the Thursday, one of the chief events was Latham's 43 miles accomplished in 1 hour 2 minutes in the morning and his 96.5 miles in 2 hours 13 minutes in the afternoon, the latter flight only terminated by running out of petrol. On the Friday, the Colonel Renard French airship, which had flown over the ground under the pilotage of M. Kapfarer, paid Rheims a second visit; Latham manoeuvred round the airship on his Antoinette and finally left it far behind. Henry Farman won the Grand Prix de Champagne on this day, covering 112 miles in 3 hours, 4 minutes, 56 seconds, Latham being second with his 96.5 miles flight, and Paulhan third. On the Saturday, Glenn Curtiss came to his own, winning the Gordon-Bennett Cup by covering 20 kilometres in 15 minutes 50.6 seconds. Bleriot made a good second with 15 minutes 56.2 seconds as his time, and Latham and Lefebvre were third and fourth. Farman carried off the passenger prize by carrying two passengers a distance of 6 miles in 10 minutes 39 seconds. On the last day Delagrange narrowly escaped serious accident through the bursting of his propeller while in the air, Curtiss made a new speed record by travelling at the rate of over 50 miles an hour, and Latham, rising to 500 feet, won the altitude prize. These are the cold statistics of the meeting; at this length of time it is difficult to convey any idea of the enthusiasm of the crowds over the achievements of the various competitors, while the incidents of the week, comic and otherwise, are nearly forgotten now even by those present in this making of history. Latham's great flight on the Thursday was rendered a breathless episode by a downpour of rain when he had covered all but a kilometre of the record distance previously achieved by Paulhan, and there was wild enthusiasm when Latham flew on through the rain until he had put up a new record and his petrol had run out. Again, on the Friday afternoon, the Colonel Renard took the air together with a little French dirigible, Zodiac III; Latham was already in the air directly over Farman, who was also flying, and three crows which turned out as rivals to the human aviators received as much cheering for their appearance as had been accorded to the machines, which doubtless they could not understand. Frightened by the cheering, the crows tried to escape from the course, but as they came near the stands, the crowd rose to cheer again and the crows wheeled away to make a second charge towards safety, with the same result; the crowd rose and cheered at them a third and fourth time; between ten and fifteen thousand people stood on chairs and tables and waved hats and handkerchiefs at three ordinary, everyday crows. One thoughtful spectator, having thoroughly enjoyed the funny side of the incident, remarked that the ultimate mastery of the air lies with the machine that comes nearest to natural flight. This still remains for the future to settle. Farman's world record, which won the Grand Prix de Champagne, was done with a Gnome Rotary Motor which had only been run on the test bench and was fitted to his machine four hours before he started on the great flight. His propeller had never been tested, having only been completed the night before. The closing laps of that flight, extending as they did into the growing of the dusk, made a breathlessly eerie experience for such of the spectators as stayed on to watch--and these were many. Night came on steadily and Farman covered lap after lap just as steadily, a buzzing, circling mechanism with something relentless in its isolated persistency. The final day of the meeting provided a further record in the quarter million spectators who turned up to witness the close of the great week. Bleriot, turning out in the morning, made a landing in some such fashion as flooded the carburettor and caused it to catch fire. Bleriot himself was badly burned, since the petrol tank burst and, in the end, only the metal parts of the machine were left. Glenn Curtis tried to beat Bleriot's time for a lap of the course, but failed. In the evening, Farman and Latham went out and up in great circles, Farman cleaving his way upward in what at the time counted for a huge machine, on circles of about a mile diameter. His first round took him level with the top of the stands, and, in his second, he circled the captive balloon anchored in the middle of the grounds. After another circle, he came down on a long glide, when Latham's lean Antoinette monoplane went up in circles more graceful than those of Farman. 'Swiftly it rose and swept round close to the balloon, veered round to the hangars, and out over to the Rheims road. Back it came high over the stands, the people craning their necks as the shrill cry of the engine drew nearer and nearer behind the stands. Then of a sudden, the little form appeared away up in the deep twilight blue vault of the sky, heading straight as an arrow for the anchored balloon. Over it, and high, high above it went the Antoinette, seemingly higher by many feet than the Farman machine. Then, wheeling in a long sweep to the left, Latham steered his machine round past the stands, where the people, their nerve-tension released on seeing the machine descending from its perilous height of 500 feet, shouted their frenzied acclamations to the hero of the meeting. 'For certainly "Le Tham," as the French call him, was the popular hero. He always flew high, he always flew well, and his machine was a joy to the eye, either afar off or at close quarters. The public feeling for Bleriot is different. Bleriot, in the popular estimation, is the man who fights against odds, who meets the adverse fates calmly and with good courage, and to whom good luck comes once in a while as a reward for much labour and anguish, bodily and mental. Latham is the darling of the Gods, to whom Fate has only been unkind in the matter of the Channel flight, and only then because the honour belonged to Bleriot. 'Next to these two, the public loved most Lefebvre, the joyous, the gymnastic. Lefebvre was the comedian of the meeting. When things began to flag, the gay little Lefebvre would trot out to his starting rail, out at the back of the judge's enclosure opposite the stands, and after a little twisting of propellers his Wright machine would bounce off the end of its starting rail and proceed to do the most marvellous tricks for the benefit of the crowd, wheeling to right and left, darting up and down, now flying over a troop of the cavalry who kept the plain clear of people and sending their horses into hysterics, anon making straight for an unfortunate photographer who would throw himself and his precious camera flat on the ground to escape annihilation as Lefebvre swept over him 6 or 7 feet off the ground. Lefebvre was great fun, and when he had once found that his machine was not fast enough to compete for speed with the Bleriots, Antoinettes, and Curtiss, he kept to his metier of amusing people. The promoters of the meeting owe Lefebvre a debt of gratitude, for he provided just the necessary comic relief.'--(The Aero, September 7th, 1909.) It may be noted, in connection with the fact that Cockburn was the only English competitor at the meeting, that the Rheims Meeting did more than anything which had preceded it to waken British interest in aviation. Previously, heavier-than-air flight in England had been regarded as a freak business by the great majority, and the very few pioneers who persevered toward winning England a share in the conquest of the air came in for as much derision as acclamation. Rheims altered this; it taught the world in general, and England in particular, that a serious rival to the dirigible balloon had come to being, and it awakened the thinking portion of the British public to the fact that the aeroplane had a future. The success of this great meeting brought about a host of imitations of which only a few deserve bare mention since, unlike the first, they taught nothing and achieved little. There was the meeting at Boulogne late in September of 1909, of which the only noteworthy event was Ferber's death. There was a meeting at Brescia where Curtiss again took first prize for speed and Rougier put up a world's height record of 645 feet. The Blackpool meeting followed between 18th and 23rd of October, 1909, forming, with the exception of Doncaster, the first British Flying Meeting. Chief among the competitors were Henry Farman, who took the distance prize, Rougier, Paulhan, and Latham, who, by a flight in a high wind, convinced the British public that the theory that flying was only possible in a calm was a fallacy. A meeting at Doncaster was practically simultaneous with the Blackpool week; Delagrange, Le Blon, Sommer, and Cody were the principal figures in this event. It should be added that 130 miles was recorded as the total flown at Doncaster, while at Blackpool only 115 miles were flown. Then there were Juvisy, the first Parisian meeting, Wolverhampton, and the Comte de Lambert's flight round the Eiffel Tower at a height estimated at between 1,200 and 1,300 feet. This may be included in the record of these aerial theatricals, since it was nothing more. Probably wakened to realisation of the possibilities of the aeroplane by the Rheims Meeting, Germany turned out its first plane late in 1909. It was known as the Grade monoplane, and was a blend of the Bleriot and Santos-Dumont machines, with a tail suggestive of the Antoinette type. The main frame took the form of a single steel tube, at the forward end of which was rigged a triangular arrangement carrying the pilot's seat and the landing wheels underneath, with the wing warping wires and stays above. The sweep of the wings was rather similar to the later Taube design, though the sweep back was not so pronounced, and the machine was driven by a four-cylinder, 20 horse-power, air-cooled engine which drove a two-bladed tractor propeller. In spite of Lilienthal's pioneer work years before, this was the first power-driven German plane which actually flew. Eleven months after the Rheims meeting came what may be reckoned the only really notable aviation meeting on English soil, in the form of the Bournemouth week, July 10th to 16th, 1910. This gathering is noteworthy mainly in view of the amazing advance which it registered on the Rheims performances. Thus, in the matter of altitude, Morane reached 4,107 feet and Drexel came second with 2,490 feet. Audemars on a Demoiselle monoplane made a flight of 17 miles 1,480 yards in 27 minutes 17.2 seconds, a great flight for the little Demoiselle. Morane achieved a speed of 56.64 miles per hour, and Grahame White climbed to 1,000 feet altitude in 6 minutes 36.8 seconds. Machines carrying the Gnome engine as power unit took the great bulk of the prizes, and British-built engines were far behind. The Bournemouth Meeting will always be remembered with regret for the tragedy of C. S. Rolls's death, which took place on the Tuesday, the second day of the meeting. The first competition of the day was that for the landing prize; Grahame White, Audemars, and Captain Dickson had landed with varying luck, and Rolls, following on a Wright machine with a tail-plane which ought never to have been fitted and was not part of the Wright design, came down wind after a left-hand turn and turned left again over the top of the stands in order to land up wind. He began to dive when just clear of the stands, and had dropped to a height of 40 feet when he came over the heads of the people against the barriers. Finding his descent too steep, he pulled back his elevator lever to bring the nose of the machine up, tipping down the front end of the tail to present an almost flat surface to the wind. Had all gone well, the nose of the machine would have been forced up, but the strain on the tail and its four light supports was too great; the tail collapsed, the wind pressed down the biplane elevator, and the machine dived vertically for the remaining 20 feet of the descent, hitting the ground vertically and crumpling up. Major Kennedy, first to reach the debris, found Rolls lying with his head doubled under him on the overturned upper main plane; the lower plane had been flung some few feet away with the engine and tanks under it. Rolls was instantaneously killed by concussion of the brain. Antithesis to the tragedy was Audemars on his Demoiselle, which was named 'The Infuriated Grasshopper.' Concerning this, it was recorded at the time that 'Nothing so excruciatingly funny as the action of this machine has ever been seen at any aviation ground. The little two-cylinder engine pops away with a sound like the frantic drawing of ginger beer corks; the machine scutters along the ground with its tail well up; then down comes the tail suddenly and seems to slap the ground while the front jumps up, and all the spectators rock with laughter. The whole attitude and the jerky action of the machine suggest a grasshopper in a furious rage, and the impression is intensified when it comes down, as it did twice on Wednesday, in long grass, burying its head in the ground in its temper.'--(The Aero, July, 1910.) The Lanark Meeting followed in August of the same year, and with the bare mention of this, the subject of flying meetings may he left alone, since they became mere matters of show until there came military competitions such as the Berlin Meeting at the end of August, 1910, and the British War office Trials on Salisbury Plain, when Cody won his greatest triumphs. The Berlin meeting proved that, from the time of the construction of the first successful German machine mentioned above, to the date of the meeting, a good number of German aviators had qualified for flight, but principally on Wright and Antoinette machines, though by that time the Aviatik and Dorner German makes had taken the air. The British War office Trials deserve separate and longer mention. In 1910 in spite of official discouragement, Captain Dickson proved the value of the aeroplane for scouting purposes by observing movements of troops during the Military Manoeuvres on Salisbury Plain. Lieut. Lancelot Gibbs and Robert Loraine, the actor-aviator, also made flights over the manoeuvre area, locating troops and in a way anticipating the formation and work of the Royal Flying Corps by a usefulness which could not be officially recognised. XV. THE CHANNEL CROSSING It may be said that Louis Bleriot was responsible for the second great landmark in the history of successful flight. The day when the brothers Wright succeeded in accomplishing power-driven flight ranks as the first of these landmarks. Ader may or may not have left the ground, but the wreckage of his 'Avion' at the end of his experiment places his doubtful success in a different category from that of the brothers Wright and leaves them the first definite conquerors, just as Bleriot ranks as first definite conqueror of the English Channel by air. In a way, Louis Bleriot ranks before Farman in point of time; his first flapping-wing model was built as early as 1900, and Voisin flew a biplane glider of his on the Seine in the very early experimental days. Bleriot's first four machines were biplanes, and his fifth, a monoplane, was wrecked almost immediately after its construction. Bleriot had studied Langley's work to a certain extent, and his sixth construction was a double monoplane based on the Langley principle. A month after he had wrecked this without damaging himself--for Bleriot had as many miraculous escapes as any of the other fliers-he brought out number seven, a fairly average monoplane. It was in December of 1907 after a series of flights that he wrecked this machine, and on its successor, in July of 1908, he made a flight of over 8 minutes. Sundry flights, more or less successful, including the first cross-country flight from Toury to Artenay, kept him busy up to the beginning of November, 1908, when the wreckage in a fog of the machine he was flying sent him to the building of 'number eleven,' the famous cross-channel aeroplane. Number eleven was shown at the French Aero Show in the Grand Palais and was given its first trials on the 18th January, 1909. It was first fitted with a R.E.P. motor and had a lifting area of 120 square feet, which was later increased to 150 square feet. The framework was of oak and poplar spliced and reinforced with piano wire; the weight of the machine was 47 lbs. and the undercarriage weight a further 60 lbs., this consisting of rubber cord shock absorbers mounted on two wheels. The R.E.P. motor was found unsatisfactory, and a three-cylinder Anzani of 105 mm. bore and 120 mm. stroke replaced it. An accident seriously damaged the machine on June 2nd, but Bleriot repaired it and tested it at Issy, where between June 19th and June 23rd he accomplished flights of 8, 12, 15, 16, and 36 minutes. On July 4th he made a 50-minute flight and on the 13th flew from Etampes to Chevilly. A few further details of construction may be given: the wings themselves and an elevator at the tail controlled the rate of ascent and descent, while a rudder was also fitted at the tail. The steering lever, working on a universally jointed shaft--forerunner of the modern joystick--controlled both the rudder and the wings, while a pedal actuated the elevator. The engine drove a two-bladed tractor screw of 6 feet 7 inches diameter, and the angle of incidence of the wings was 20 degrees. Timed at Issy, the speed of the machine was given as 36 miles an hour, and as Bleriot accomplished the Channel flight of 20 miles in 37 minutes, he probably had a slight following wind. The Daily Mail had offered a prize of L1,000 for the first Cross-Channel flight, and Hubert Latham set his mind on winning it. He put up a shelter on the French coast at Sangatte, half-way between Calais and Cape Blanc Nez. From here he made his first attempt to fly to England on Monday the 19th of July. He soared to a fair height, circling, and reached an estimated height of about 900 feet as he came over the water with every appearance of capturing the Cross-Channel prize. The luck which dogged his career throughout was against him, for, after he had covered some 8 miles, his engine stopped and he came down to the water in a series of long glides. It was discovered afterward that a small piece of wire had worked its way into a vital part of the engine to rob Latham of the honour he coveted. The tug that came to his rescue found him seated on the fuselage of his Antoinette, smoking a cigarette and waiting for a boat to take him to the tug. It may be remarked that Latham merely assumed his Antoinette would float in case he failed to make the English coast; he had no actual proof. Bleriot immediately entered his machine for the prize and took up his quarters at Barraques. On Sunday, July 25th, 1909, shortly after 4 a.m., Bleriot had his machine taken out from its shelter and prepared for flight. He had been recently injured in a petrol explosion and hobbled out on crutches to make his cross-Channel attempt; he made two great circles in the air to try the machine, and then alighted. 'In ten minutes I start for England,' he declared, and at 4.35 the motor was started up. After a run of 100 yards, the machine rose in the air and got a height of about 100 feet over the land, then wheeling sharply seaward and heading for Dover. Bleriot had no means of telling direction, and any change of wind might have driven him out over the North Sea, to be lost, as were Cecil Grace and Hamel later on. Luck was with him, however, and at 5.12 a.m. of that July Sunday, he made his landing in the North Fall meadow, just behind Dover Castle. Twenty minutes out from the French coast, he lost sight of the destroyer which was patrolling the Channel, and at the same time he was out of sight of land without compass or any other means of ascertaining his direction. Sighting the English coast, he found that he had gone too far to the east, for the wind increased in strength throughout the flight, this to such an extent as almost to turn the machine round when he came over English soil. Profiting by Latham's experience, Bleriot had fitted an inflated rubber cylinder a foot in diameter by 5 feet in length along the middle of his fuselage, to render floating a certainty in case he had to alight on the water. Latham in his camp at Sangatte had been allowed to sleep through the calm of the early morning through a mistake on the part of a friend, and when his machine was turned out--in order that he might emulate Bleriot, although he no longer hoped to make the first flight, it took so long to get the machine ready and dragged up to its starting-point that there was a 25 mile an hour wind by the time everything was in readiness. Latham was anxious to make the start in spite of the wind, but the Directors of the Antoinette Company refused permission. It was not until two days later that the weather again became favourable, and then with a fresh machine, since the one on which he made his first attempt had been very badly damaged in being towed ashore, he made a circular trial flight of about 5 miles. In landing from this, a side gust of wind drove the nose of the machine against a small hillock, damaging both propeller blades and chassis, and it was not until evening that the damage was repaired. French torpedo boats were set to mark the route, and Latham set out on his second attempt at six o'clock. Flying at a height of 200 feet, he headed over the torpedo boats for Dover and seemed certain of making the English coast, but a mile and a half out from Dover his engine failed him again, and he dropped to the water to be picked up by the steam pinnace of an English warship and put aboard the French destroyer Escopette. There is little to choose between the two aviators for courage in attempting what would have been considered a foolhardy feat a year or two before. Bleriot's state, with an abscess in the burnt foot which had to control the elevator of his machine, renders his success all the more remarkable. His machine was exhibited in London for a time, and was afterwards placed in the Conservatoire des Arts et Metiers, while a memorial in stone, copying his monoplane in form, was let into the turf at the point where he landed. The second Channel crossing was not made until 1910, a year of new records. The altitude record had been lifted to over 10,000 feet, the duration record to 8 hours 12 minutes, and the distance for a single flight to 365 miles, while a speed of over 65 miles an hour had been achieved, when Jacques de Lesseps, son of the famous engineer of Suez Canal and Panama fame, crossed from France to England on a Bleriot monoplane. By this time flying had dropped so far from the marvellous that this second conquest of the Channel aroused but slight public interest in comparison with Bleriot's feat. The total weight of Bleriot's machine in Cross Channel trim was 660 lbs., including the pilot and sufficient petrol for a three hours' run; at a speed of 37 miles an hour, it was capable of carrying about 5 lbs. per square foot of lifting surface. It was the three-cylinder 25 horse-power Anzani motor which drove the machine for the flight. Shortly after the flight had been accomplished, it was announced that the Bleriot firm would construct similar machines for sale at L400 apiece--a good commentary on the prices of those days. On June the 2nd, 1910, the third Channel crossing was made by C. S. Rolls, who flew from Dover, got himself officially observed over French soil at Barraques, and then flew back without landing. He was the first to cross from the British side of the Channel and also was the first aviator who made the double journey. By that time, however, distance flights had so far increased as to reduce the value of the feat, and thenceforth the Channel crossing was no exceptional matter. The honour, second only to that of the Wright Brothers, remains with Bleriot. XVI. LONDON TO MANCHESTER The last of the great contests to arouse public enthusiasm was the London to Manchester Flight of 1910. As far back as 1906, the Daily Mail had offered a prize of L10,000 to the first aviator who should accomplish this journey, and, for a long time, the offer was regarded as a perfectly safe one for any person or paper to make--it brought forth far more ridicule than belief. Punch offered a similar sum to the first man who should swim the Atlantic and also for the first flight to Mars and back within a week, but in the spring of 1910 Claude Grahame White and Paulhan, the famous French pilot, entered for the 183 mile run on which the prize depended. Both these competitors flew the Farman biplane with the 50 horse-power Gnome motor as propulsive power. Grahame White surveyed the ground along the route, and the L. & N. W. Railway Company, at his request, whitewashed the sleepers for 100 yards on the north side of all junctions to give him his direction on the course. The machine was run out on to the starting ground at Park Royal and set going at 5.19 a.m. on April 23rd. After a run of 100 yards, the machine went up over Wormwood Scrubs on its journey to Normandy, near Hillmorten, which was the first arranged stopping place en route; Grahame White landed here in good trim at 7.20 a.m., having covered 75 miles and made a world's record cross country flight. At 8.15 he set off again to come down at Whittington, four miles short of Lichfield, at about 9.20, with his machine in good order except for a cracked landing skid. Twice, on this second stage of the journey, he had been caught by gusts of wind which turned the machine fully round toward London, and, when over a wood near Tamworth, the engine stopped through a defect in the balance springs of two exhaust valves; although it started up again after a 100 foot glide, it did not give enough power to give him safety in the gale he was facing. The rising wind kept him on the ground throughout the day, and, though he hoped for better weather, the gale kept up until the Sunday evening. The men in charge of the machine during its halt had attempted to hold the machine down instead of anchoring it with stakes and ropes, and, in consequence of this, the wind blew the machine over on its back, breaking the upper planes and the tail. Grahame White had to return to London, while the damaged machine was prepared for a second flight. The conditions of the competition enacted that the full journey should be completed within 24 hours, which made return to the starting ground inevitable. Louis Paulhan, who had just arrived with his Farman machine, immediately got it unpacked and put together in order to be ready to make his attempt for the prize as soon as the weather conditions should admit. At 5.31 p.m., on April 27th, he went up from Hendon and had travelled 50 miles when Grahame White, informed of his rival's start, set out to overtake him. Before nightfall Paulhan landed at Lichfield, 117 miles from London, while Grahame White had to come down at Roden, only 60 miles out. The English aviator's chance was not so small as it seemed, for, as Latham had found in his cross-Channel attempts, engine failure was more the rule than the exception, and a very little thing might reverse the relative positions. A special train accompanied Paulhan along the North-Western route, conveying Madame Paulhan, Henry Farman, and the mechanics who fitted the Farman biplane together. Paulhan himself, who had flown at a height of 1,000 feet, spent the night at Lichfield, starting again at 4.9 a.m. On the 28th, passing Stafford at 4.45, Crewe at 5.20, and landing at Burnage, near Didsbury, at 5.32, having had a clean run. Meanwhile, Grahame White had made a most heroic attempt to beat his rival. An hour before dawn on the 28th, he went to the small field in which his machine had landed, and in the darkness managed to make an ascent from ground which made starting difficult even in daylight. Purely by instinct and his recollection of the aspect of things the night before, he had to clear telegraph wires and a railway bridge, neither of which he could possibly see at that hour. His engine, too, was faltering, and it was obvious to those who witnessed his start that its note was far from perfect. At 3.50 he was over Nuneaton and making good progress; between Atherstone and Lichfield the wind caught him and the engine failed more and more, until at 4.13 in the morning he was forced to come to earth, having covered 6 miles less distance than in his first attempt. It was purely a case of engine failure, for, with full power, he would have passed over Paulhan just as the latter was preparing for the restart. Taking into consideration the two machines, there is little doubt that Grahame White showed the greater flying skill, although he lost the prize. After landing and hearing of Paulhan's victory, on which he wired congratulations, he made up his mind to fly to Manchester within the 24 hours. He started at 5 o'clock in the afternoon from Polesworth, his landing place, but was forced to land at 5.30 at Whittington, where he had landed on the previous Saturday. The wind, which had forced his descent, fell again and permitted of starting once more; on this third stage he reached Lichfield, only to make his final landing at 7.15 p.m., near the Trent Valley station. The defective running of the Gnome engine prevented his completing the course, and his Farman machine had to be brought back to London by rail. The presentation of the prize to Paulhan was made the occasion for the announcement of a further competition, consisting of a 1,000 mile flight round a part of Great Britain. In this, nineteen competitors started, and only four finished; the end of the race was a great fight between Beaumont and Vedrines, both of whom scorned weather conditions in their determination to win. Beaumont made the distance in a flying time of 22 hours 28 minutes 19 seconds, and Vedrines covered the journey in a little over 23 1/2 hours. Valentine came third on a Deperdussin monoplane and S. F. Cody on his Cathedral biplane was fourth. This was in 1911, and by that time heavier-than-air flight had so far advanced that some pilots had had war experience in the Italian campaign in Tripoli, while long cross-country flights were an everyday event, and bad weather no longer counted. XVII. A SUMMARY, TO 1911 There is so much overlapping in the crowded story of the first years of successful power-driven flight that at this point it is advisable to make a concise chronological survey of the chief events of the period of early development, although much of this is of necessity recapitulation. The story begins, of course, with Orville Wright's first flight of 852 feet at Kitty Hawk on December 19th, 1903. The next event of note was Wright's flight of 11.12 miles in 18 minutes 9 seconds at Dayton, Ohio, on September 26th, 1905, this being the first officially recorded flight. On October 4th of the same year, Wright flew 20.75 miles in 33 minutes 17 seconds, this being the first flight of over 20 miles ever made. Then on September 14th 1906, Alberto Santos-Dumont made a flight of eight seconds on the second heavier-than-air machine he had constructed. It was a big box-kite-like machine; this was the second power-driven aeroplane in Europe to fly, for although Santos-Dumont's first machine produced in 1905 was reckoned an unsuccessful design, it had actually got off the ground for brief periods. Louis Bleriot came into the ring on April 5th, 1907, with a first flight of 6 seconds on a Bleriot monoplane, his eighth but first successful construction. Henry Farman made his first appearance in the history of aviation with a flight of 935 feet on a Voisin biplane on October 15th 1907. On October 25th, in a flight of 2,530 feet, he made the first recorded turn in the air, and on March 29th, 1908, carrying Leon Delagrange on a Voisin biplane, he made the first passenger flight. On April 10th of this year, Delagrange, in flying 1 1/2 miles, made the first flight in Europe exceeding a mile in distance. He improved on this by flying 10 1/2 miles at Milan on June 22nd, while on July 8th, at Turin, he took up Madame Peltier, the first woman to make an aeroplane flight. Wilbur Wright, coming over to Europe, made his first appearance on the Continent with a flight of 1 3/4 minutes at Hunaudieres, France, on August 8th, 1908. On September 6th, at Chalons, he flew for 1 hour 4 minutes 26 seconds with a passenger, this being the first flight in which an hour in the air was exceeded with a passenger on board. On September 12th 1908, Orville Wright, flying at Fort Meyer, U.S.A., with Lieut. Selfridge as passenger, crashed his machine, suffering severe injuries, while Selfridge was killed. This was the first aeroplane fatality. On October 30th, 1908, Farman made the first cross-country flight, covering the distance of 17 miles between Bouy and Rheims. The next day, Louis Bleriot, in flying from Toury to Artenay, made two landings en route, this being the first cross-country flight with landings. On the last day of the year, Wilbur Wright won the Michelin Cup at Auvours with a flight of 90 miles, which, lasting 2 hours 20 minutes 23 seconds, exceeded 2 hours in the air for the first time. On January 2nd, 1909, S. F. Cody opened the New Year by making the first observed flight at Farnborough on a British Army aeroplane. It was not until July 18th of 1909 that the first European height record deserving of mention was put up by Paulhan, who achieved a height of 450 feet on a Voisin biplane. This preceded Latham's first attempt to fly the Channel by two days, and five days later, on the 25th of the month, Bleriot made the first Channel crossing. The Rheims Meeting followed on August 22nd, and it was a great day for aviation when nine machines were seen in the air at once. It was here that Farman, with a 118 mile flight, first exceeded the hundred miles, and Latham raised the height record officially to 500 feet, though actually he claimed to have reached 1,200 feet. On September 8th, Cody, flying from Aldershot, made a 40 mile journey, setting up a new cross-country record. On October 19th the Comte de Lambert flew from Juvisy to Paris, rounded the Eiffel Tower and flew back. J. T. C. Moore-Brabazon made the first circular mile flight by a British aviator on an all-British machine in Great Britain, on October 30th, flying a Short biplane with a Green engine. Paulhan, flying at Brooklands on November 2nd, accomplished 96 miles in 2 hours 48 minutes, creating a British distance record; on the following day, Henry Farman made a flight of 150 miles in 4 hours 22 minutes at Mourmelon, and on the 5th of the month, Paulhan, flying a Farman biplane, made a world's height record of 977 feet. This, however, was not to stand long, for Latham got up to 1,560 feet on an Antoinette at Mourmelon on December 1st. December 31st witnessed the first flight in Ireland, made by H. Ferguson on a monoplane which he himself had constructed at Downshire Park, Lisburn. These, thus briefly summarised, are the principal events up to the end of 1909. 1910 opened with tragedy, for on January 4th Leon Delagrange, one of the greatest pilots of his time, was killed while flying at Pau. The machine was the Bleriot XI which Delagrange had used at the Doncaster meeting, and to which Delagrange had fitted a 50 horse-power Gnome engine, increasing the speed of the machine from its original 30 to 45 miles per hour. With the Rotary Gnome engine there was of necessity a certain gyroscopic effect, the strain of which proved too much for the machine. Delagrange had come to assist in the inauguration of the Croix d'Hins aerodrome, and had twice lapped the course at a height of about 60 feet. At the beginning of the third lap, the strain of the Gnome engine became too great for the machine; one wing collapsed as if the stay wires had broken, and the whole machine turned over and fell, killing Delagrange. On January 7th Latham, flying at Mourmelon, first made the vertical kilometre and dedicated the record to Delagrange, this being the day of his friend's funeral. The record was thoroughly authenticated by a large registering barometer which Latham carried, certified by the officials of the French Aero Club. Three days later Paulhan, who was at Los Angeles, California, raised the height record to 4,146 feet. On January 25th the Brussels Exhibition opened, when the Antoinette monoplane, the Gaffaux and Hanriot monoplanes, together with the d'Hespel aeroplane, were shown; there were also the dirigible Belgica and a number of interesting aero engines, including a German airship engine and a four-cylinder 50 horse-power Miesse, this last air-cooled by means of 22 fans driving a current of air through air jackets surrounding fluted cylinders. On April 2nd Hubert Le Blon, flying a Bleriot with an Anzani engine, was killed while flying over the water. His machine was flying quite steadily, when it suddenly heeled over and came down sideways into the sea; the motor continued running for some seconds and the whole machine was drawn under water. When boats reached the spot, Le Blon was found lying back in the driving seat floating just below the surface. He had done good flying at Doncaster, and at Heliopolis had broken the world's speed records for 5 and 10 kilometres. The accident was attributed to fracture of one of the wing stay wires when running into a gust of wind. The next notable event was Paulhan's London-Manchester flight, of which full details have already been given. In May Captain Bertram Dickson, flying at the Tours meeting, beat all the Continental fliers whom he encountered, including Chavez, the Peruvian, who later made the first crossing of the Alps. Dickson was the first British winner of international aviation prizes. C. S. Rolls, of whom full details have already been given, was killed at Bournemouth on July 12th, being the first British aviator of note to be killed in an aeroplane accident. His return trip across the Channel had taken place on June 2nd. Chavez, who was rapidly leaping into fame, as a pilot, raised the British height record to 5,750 feet while flying at Blackpool on August 3rd. On the 11th of that month, Armstrong Drexel, flying a Bleriot, made a world's height record of 6,745 feet. It was in 1910 that the British War office first began fully to realise that there might be military possibilities in heavier-than-air flying. C. S. Rolls had placed a Wright biplane at the disposal of the military authorities, and Cody, as already recorded, had been experimenting with a biplane type of his own for some long period. Such development as was achieved was mainly due to the enterprise and energy of Colonel J. E. Capper, C.B., appointed to the superintendency of the Balloon Factory and Balloon School at Farnborough in 1906. Colonel Capper's retirement in 1910 brought (then) Mr Mervyn O'Gorman to command, and by that time the series of successes of the Cody biplane, together with the proved efficiency of the aeroplane in various civilian meetings, had convinced the British military authorities that the mastery of the air did not lie altogether with dirigible airships, and it may be said that in 1910 the British War office first began seriously to consider the possibilities of the aeroplane, though two years more were to elapse before the formation of the Royal Flying Corps marked full realisation of its value. A triumph and a tragedy were combined in September of 1910. On the 23rd of the month, Georges Chavez set out to fly across the Alps on a Bleriot monoplane. Prizes had been offered by the Milan Aviation Committee for a flight from Brigue in Switzerland over the Simplon Pass to Milan, a distance of 94 miles with a minimum height of 6,600 feet above sea level. Chavez started at 1.30 p.m. On the 23rd, and 41 minutes later he reached Domodossola, 25 miles distant. Here he descended, numbed with the cold of the journey; it was said that the wings of his machine collapsed when about 30 feet from the ground, but however this may have been, he smashed the machine on landing, and broke both legs, in addition to sustaining other serious injuries. He lay in hospital until the 27th September, when he died, having given his life to the conquest of the Alps. His death in the moment of success was as great a tragedy as were those of Pilcher and Lilienthal. The day after Chavez's death, Maurice Tabuteau flew across the Pyrenees, landing in the square at Biarritz. On December 30th, Tabuteau made a flight of 365 miles in 7 hours 48 minutes. Farman, on December 18th, had flown for over 8 hours, but his total distance was only 282 miles. The autumn of this year was also noteworthy for the fact that aeroplanes were first successfully used in the French Military Manoeuvres. The British War Office, by the end of the year, had bought two machines, a military type Farman and a Paulhan, ignoring British experimenters and aeroplane builders of proved reliability. These machines, added to an old Bleriot two-seater, appear to have constituted the British aeroplane fleet of the period. There were by this time three main centres of aviation in England, apart from Cody, alone on Laffan's Plain. These three were Brooklands, Hendon, and the Isle of Sheppey, and of the three Brooklands was chief. Here such men as Graham Gilmour, Rippen, Leake, Wickham, and Thomas persistently experimented. Hendon had its own little group, and Shellbeach, Isle of Sheppey, held such giants of those days as C. S. Rolls and Moore Brabazon, together with Cecil Grace and Rawlinson. One or other, and sometimes all of these were deserted on the occasion of some meeting or other, but they were the points where the spade work was done, Brooklands taking chief place. 'If you want the early history of flying in England, it is there,' one of the early school remarked, pointing over toward Brooklands course. 1911 inaugurated a new series of records of varying character. On the 17th January, E. B. Ely, an American, flew from the shore of San Francisco to the U.S. cruiser Pennsylvania, landing on the cruiser, and then flew back to the shore. The British military designing of aeroplanes had been taken up at Farnborough by G. H. de Havilland, who by the end of January was flying a machine of his own design, when he narrowly escaped becoming a casualty through collision with an obstacle on the ground, which swept the undercarriage from his machine. A list of certified pilots of the countries of the world was issued early in 1911, showing certificates granted up to the end of 1910. France led the way easily with 353 pilots; England came next with 57, and Germany next with 46; Italy owned 32, Belgium 27, America 26, and Austria 19; Holland and Switzerland had 6 aviators apiece, while Denmark followed with 3, Spain with 2, and Sweden with 1. The first certificate in England was that of J. T. C. Moore-Brabazon, while Louis Bleriot was first on the French list and Glenn Curtiss, first holder of an American certificate, also held the second French brevet. On the 7th March, Eugene Renaux won the Michelin Grand Prize by flying from the French Aero Club ground at St Cloud and landing on the Puy de Dome. The landing, which was one of the conditions of the prize, was one of the most dangerous conditions ever attached to a competition; it involved dropping on to a little plateau 150 yards square, with a possibility of either smashing the machine against the face of the mountain, or diving over the edge of the plateau into the gulf beneath. The length of the journey was slightly over 200 miles and the height of the landing point 1,465 metres, or roughly 4,500 feet above sea-level. Renaux carried a passenger, Doctor Senoucque, a member of Charcot's South Polar Expedition. The 1911 Aero Exhibition held at Olympia bore witness to the enormous strides made in construction, more especially by British designers, between 1908 and the opening of the Show. The Bristol Firm showed three machines, including a military biplane, and the first British built biplane with tractor screw. The Cody biplane, with its enormous size rendering it a prominent feature of the show, was exhibited. Its designer anticipated later engines by expressing his desire for a motor of 150 horse-power, which in his opinion was necessary to get the best results from the machine. The then famous Dunne monoplane was exhibited at this show, its planes being V-shaped in plan, with apex leading. It embodied the results of very lengthy experiments carried out both with gliders and power-driven machines by Colonel Capper, Lieut. Gibbs, and Lieut. Dunne, and constituted the longest step so far taken in the direction of inherent stability. Such forerunners of the notable planes of the war period as the Martin Handasyde, the Nieuport, Sopwith, Bristol, and Farman machines, were features of the show; the Handley-Page monoplane, with a span of 32 feet over all, a length of 22 feet, and a weight of 422 lbs., bore no relation at all to the twin-engined giant which later made this firm famous. In the matter of engines, the principal survivals to the present day, of which this show held specimens, were the Gnome, Green, Renault air-cooled, Mercedes four-cylinder dirigible engine of 115 horse-power, and 120 horsepower Wolseley of eight cylinders for use with dirigibles. On April 12th, of 1911, Paprier, instructor at the Bleriot school at Hendon, made the first non-stop flight between London and Paris. He left the aerodrome at 1.37 p.m., and arrived at Issy-les-Moulineaux at 5.33 p.m., thus travelling 250 miles in a little under 4 hours. He followed the railway route practically throughout, crossing from Dover to nearly opposite Calais, keeping along the coast to Boulogne, and then following the Nord Railway to Amiens, Beauvais, and finally Paris. In May, the Paris-Madrid race took place; Vedrines, flying a Morane biplane, carried off the prize by first completing the distance of 732 miles. The Paris-Rome race of 916 miles was won in the same month by Beaumont, flying a Bleriot monoplane. In July, Koenig won the German National Circuit race of 1,168 miles on an Albatross biplane. This was practically simultaneous with the Circuit of Britain won by Beaumont, who covered 1,010 miles on a Bleriot monoplane, having already won the Paris-Brussels-London-Paris Circuit of 1,080 miles, this also on a Bleriot. It was in August that a new world's height record of 11,152 feet was set up by Captain Felix at Etampes, while on the 7th of the month Renaux flew nearly 600 miles on a Maurice Farman machine in 12 hours. Cody and Valentine were keeping interest alive in the Circuit of Britain race, although this had long been won, by determinedly plodding on at finishing the course. On September 9th, the first aerial post was tried between Hendon and Windsor, as an experiment in sending mails by aeroplane. Gustave Hamel flew from Hendon to Windsor and back in a strong wind. A few days later, Hamel went on strike, refusing to carry further mails unless the promoters of the Aerial Postal Service agreed to pay compensation to Hubert, who fractured both his legs on the 11th of the month while engaged in aero postal work. The strike ended on September 25th, when Hamel resumed mail-carrying in consequence of the capitulation of the Postmaster-General, who agreed to set aside L500 as compensation to Hubert. September also witnessed the completion in America of a flight across the Continent, a distance of 2,600 miles. The only competitor who completed the full distance was C. P. Rogers, who was disqualified through failing to comply with the time limit. Rogers needed so many replacements to his machine on the journey that, expressing it in American fashion, he arrived with practically a dfferent aeroplane from that with which he started. With regard to the aerial postal service, analysis of the matter carried and the cost of the service seemed to show that with a special charge of one shilling for letters and sixpence for post cards, the revenue just balanced the expenditure. It was not possible to keep to the time-table as, although the trials were made in the most favourable season of the year, aviation was not sufficiently advanced to admit of facing all weathers and complying with time-table regulations. French military aeroplane trials took place at Rheims in October, the noteworthy machines being Antoinette, Farman, Nieuport, and Deperdussin. The tests showed the Nieuport monoplane with Gnome motor as first in position; the Breguet biplane was second, and the Deperdussin monoplanes third. The first five machines in order of merit were all engined with the Gnome motor. The records quoted for 1911 form the best evidence that can be given of advance in design and performance during the year. It will be seen that the days of the giants were over; design was becoming more and more standardised and aviation not so much a matter of individual courage and even daring, as of the reliability of the machine and its engine. This was the first year in which the twin-engined aeroplane made its appearance, and it was the year, too, in which flying may be said to have grown so common that the 'meetings' which began with Rheims were hardly worth holding, owing to the fact that increase in height and distance flown rendered it no longer necessary for a would-be spectator of a flight to pay half a crown and enter an enclosure. Henceforth, flying as a spectacle was very little to be considered; its commercial aspects were talked of, and to a very slight degree exploited, but, more and more, the fact that the aeroplane was primarily an engine of war, and the growing German menace against the peace of the world combined to point the way of speediest development, and the arrangements for the British Military Trials to be held in August, 1912, showed that even the British War office was waking up to the potentialities of this new engine of war. XVIII. A SUMMARY, TO 1914 Consideration of the events in the years immediately preceding the War must be limited to as brief a summary as possible, this not only because the full history of flying achievements is beyond the compass of any single book, but also because, viewing the matter in perspective, the years 1903-1911 show up as far more important as regards both design and performance. From 1912 to August of 1914, the development of aeronautics was hindered by the fact that it had not progressed far enough to form a real commercial asset in any country. The meetings which drew vast concourses of people to such places as Rheims and Bournemouth may have been financial successes at first, but, as flying grew more common and distances and heights extended, a great many people found it other than worth while to pay for admission to an aerodrome. The business of taking up passengers for pleasure flights was not financially successful, and, although schemes for commercial routes were talked of, the aeroplane was not sufficiently advanced to warrant the investment of hard cash in any of these projects. There was a deadlock; further development was necessary in order to secure financial aid, and at the same time financial aid was necessary in order to secure further development. Consequently, neither was forthcoming. This is viewing the matter in a broad and general sense; there were firms, especially in France, but also in England and America, which looked confidently for the great days of flying to arrive, and regarded their sunk capital as investment which would eventually bring its due return. But when one looks back on those years, the firms in question stand out as exceptions to the general run of people, who regarded aeronautics as something extremely scientific, exceedingly dangerous, and very expensive. The very fame that was attained by such pilots as became casualties conduced to the advertisement of every death, and the dangers attendant on the use of heavier-than-air machines became greatly exaggerated; considering the matter as one of number of miles flown, even in the early days, flying exacted no more toll in human life than did railways or road motors in the early stages of their development. But to take one instance, when C. S. Rolls was killed at Bournemouth by reason of a faulty tail-plane, the fact was shouted to the whole world with almost as much vehemence as characterised the announcement of the Titanic sinking in mid-Atlantic. Even in 1911 the deadlock was apparent; meetings were falling off in attendance, and consequently in financial benefit to the promoters; there remained, however, the knowledge--for it was proved past question--that the aeroplane in its then stage of development was a necessity to every army of the world. France had shown this by the more than interest taken by the French Government in what had developed into an Air Section of the French army; Germany, of course, was hypnotised by Count Zeppelin and his dirigibles, to say nothing of the Parsevals which had been proved useful military accessories; in spite of this, it was realised in Germany that the aeroplane also had its place in military affairs. England came into the field with the military aeroplane trials of August 1st to 15th, 1912, barely two months after the founding of the Royal Flying Corps. When the R.F.C. was founded--and in fact up to two years after its founding--in no country were the full military potentialities of the aeroplane realised; it was regarded as an accessory to cavalry for scouting more than as an independent arm; the possibilities of bombing were very vaguely considered, and the fact that it might be possible to shoot from an aeroplane was hardly considered at all. The conditions of the British Military Trials of 1912 gave to the War office the option of purchasing for L1,000 any machine that might be awarded a prize. Machines were required, among other things, to carry a useful load of 350 lbs. in addition to equipment, with fuel and oil for 4 1/2-hours; thus loaded, they were required to fly for 3 hours, attaining an altitude of 4,500 feet, maintaining a height of 1,500 feet for 1 hour, and climbing 1,000 feet from the ground at a rate of 200 feet per minute, 'although 300 feet per minute is desirable.' They had to attain a speed of not less than 55 miles per hour in a calm, and be able to plane down to the ground in a calm from not more than 1,000 feet with engine stopped, traversing 6,000 feet horizontal distance. For those days, the landing demands were rather exacting; the machine should be able to rise without damage from long grass, clover, or harrowed land, in 100 yards in a calm, and should be able to land without damage on any cultivated ground, including rough ploughed land, and, when landing on smooth turf in a calm, be able to pull up within 75 yards of the point of first touching the ground. It was required that pilot and observer should have as open a view as possible to front and flanks, and they should be so shielded from the wind as to be able to communicate with each other. These are the main provisions out of the set of conditions laid down for competitors, but a considerable amount of leniency was shown by the authorities in the competition, who obviously wished to try out every machine entered and see what were its capabilities. The beginning of the competition consisted in assembling the machines against time from road trim to flying trim. Cody's machine, which was the only one to be delivered by air, took 1 hour and 35 minutes to assemble; the best assembling time was that of the Avro, which was got into flying trim in 14 minutes 30 seconds. This machine came to grief with Lieut. Parke as pilot, on the 7th, through landing at very high speed on very bad ground; a securing wire of the under-carriage broke in the landing, throwing the machine forward on to its nose and then over on its back. Parke was uninjured, fortunately; the damaged machine was sent off to Manchester for repair and was back again on the 16th of August. It is to be noted that by this time the Royal Aircraft Factory was building aeroplanes of the B.E. and F.E. types, but at the same time it is also to be noted that British military interest in engines was not sufficient to bring them up to the high level attained by the planes, and it is notorious that even the outbreak of war found England incapable of providing a really satisfactory aero engine. In the 1912 Trials, the only machines which actually completed all their tests were the Cody biplane, the French Deperdussin, the Hanriot, two Bleriots and a Maurice Farman. The first prize of L4,000, open to all the world, went to F. S. Cody's British-built biplane, which complied with all the conditions of the competition and well earned its official acknowledgment of supremacy. The machine climbed at 280 feet per minute and reached a height of 5,000 feet, while in the landing test, in spite of its great weight and bulk, it pulled up on grass in 56 yards. The total weight was 2,690 lbs. when fully loaded, and the total area of supporting surface was 500 square feet; the motive power was supplied by a six-cylinder 120 horsepower Austro-Daimler engine. The second prize was taken by A. Deperdussin for the French-built Deperdussin monoplane. Cody carried off the only prize awarded for a British-built plane, this being the sum of L1,000, and consolation prizes of L500 each were awarded to the British Deperdussin Company and The British and Colonial Aeroplane Company, this latter soon to become famous as makers of the Bristol aeroplane, of which the war honours are still fresh in men's minds. While these trials were in progress Audemars accomplished the first flight between Paris and Berlin, setting out from Issy early in the morning of August 18th, landing at Rheims to refill his tanks within an hour and a half, and then coming into bad weather which forced him to land successively at Mezieres, Laroche, Bochum, and finally nearly Gersenkirchen, where, owing to a leaky petrol tank, the attempt to win the prize offered for the first flight between the two capitals had to be abandoned after 300 miles had been covered, as the time limit was definitely exceeded. Audemars determined to get through to Berlin, and set off at 5 in the morning of the 19th, only to be brought down by fog; starting off again at 9.15 he landed at Hanover, was off again at 1.35, and reached the Johannisthal aerodrome in the suburbs of Berlin at 6.48 that evening. As early as 1910 the British Government possessed some ten aeroplanes, and in 1911 the force developed into the Army Air Battalion, with the aeroplanes under the control of Major J. H. Fulton, R.F.A. Toward the end of 1911 the Air Battalion was handed over to (then) Brig.-Gen. D. Henderson, Director of Military Training. On June 6th, 1912, the Royal Flying Corps was established with a military wing under Major F. H. Sykes and a naval wing under Commander C. R. Samson. A joint Naval and Military Flying School was established at Upavon with Captain Godfrey M. Paine, R.N., as Commandant and Major Hugh Trenchard as Assistant Commandant. The Royal Aircraft Factory brought out the B.E. and F.E. types of biplane, admittedly superior to any other British design of the period, and an Aircraft Inspection Department was formed under Major J. H. Fulton. The military wing of the R.F.C. was equipped almost entirely with machines of Royal Aircraft Factory design, but the Navy preferred to develop British private enterprise by buying machines from private firms. On July 1st, 1914 the establishment of the Royal Naval Air Service marked the definite separation of the military and naval sides of British aviation, but the Central Flying School at Upavon continued to train pilots for both services. It is difficult at this length of time, so far as the military wing was concerned, to do full justice to the spade work done by Major-General Sir David Henderson in the early days. Just before war broke out, British military air strength consisted officially of eight squadrons, each of 12 machines and 13 in reserve, with the necessary complement of road transport. As a matter of fact, there were three complete squadrons and a part of a fourth which constituted the force sent to France at the outbreak of war. The value of General Henderson's work lies in the fact that, in spite of official stinginess and meagre supplies of every kind, he built up a skeleton organisation so elastic and so well thought out that it conformed to war requirements as well as even the German plans fitted in with their aerial needs. On the 4th of August, 1914, the nominal British air strength of the military wing was 179 machines. Of these, 82 machines proceeded to France, landing at Amiens and flying to Maubeuge to play their part in the great retreat with the British Expeditionary Force, in which they suffered heavy casualties both in personnel and machines. The history of their exploits, however, belongs to the War period. The development of the aeroplane between 1912 and 1914 can be judged by comparison of the requirements of the British War Office in 1912 with those laid down in an official memorandum issued by the War Office in February, 1914. This latter called for a light scout aeroplane, a single-seater, with fuel capacity to admit of 300 miles range and a speed range of from 50 to 85 miles per hour. It had to be able to climb 3,500 feet in five minutes, and the engine had to be so constructed that the pilot could start it without assistance. At the same time, a heavier type of machine for reconnaissance work was called for, carrying fuel for a 200 mile flight with a speed range of between 35 and 60 miles per hour, carrying both pilot and observer. It was to be equipped with a wireless telegraphy set, and be capable of landing over a 30 foot vertical obstacle and coming to rest within a hundred yards' distance from the obstacle in a wind of not more than 15 miles per hour. A third requirement was a heavy type of fighting aeroplane accommodating pilot and gunner with machine gun and ammunition, having a speed range of between 45 and 75 miles per hour and capable of climbing 3,500 feet in 8 minutes. It was required to carry fuel for a 300 mile flight and to give the gunner a clear field of fire in every direction up to 30 degrees on each side of the line of flight. Comparison of these specifications with those of the 1912 trials will show that although fighting, scouting, and reconnaissance types had been defined, the development of performance compared with the marvellous development of the earlier years of achieved flight was small. Yet the records of those years show that here and there an outstanding design was capable of great things. On the 9th September, 1912, Vedrines, flying a Deperdussin monoplane at Chicago, attained a speed of 105 miles an hour. On August 12th, G. de Havilland took a passenger to a height of 10,560 feet over Salisbury Plain, flying a B.E. biplane with a 70 horse-power Renault engine. The work of de Havilland may be said to have been the principal influence in British military aeroplane design, and there is no doubt that his genius was in great measure responsible for the excellence of the early B.E. and F.E. types. On the 31st May, 1913, H. G. Hawker, flying at Brooklands, reached a height of 11,450 feet on a Sopwith biplane engined with an 80 horse-power Gnome engine. On June 16th, with the same type of machine and engine, he achieved 12,900 feet. On the 2nd October, in the same year, a Grahame White biplane with 120 horse-power Austro-Daimler engine, piloted by Louis Noel, made a flight of just under 20 minutes carrying 9 passengers. In France a Nieuport monoplane piloted by G. Legagneaux attained a height of 6,120 metres, or just over 20,070 feet, this being the world's height record. It is worthy of note that of the world's aviation records as passed by the International Aeronautical Federation up to June 30th, 1914, only one, that of Noel, is credited to Great Britain. Just as records were made abroad, with one exception, so were the really efficient engines. In England there was the Green engine, but the outbreak of war found the Royal Flying Corps with 80 horse-power Gnomes, 70 horse-power Renaults, and one or two Antoinette motors, but not one British, while the Royal Naval Air Service had got 20 machines with engines of similar origin, mainly land planes in which the wheeled undercarriages had been replaced by floats. France led in development, and there is no doubt that at the outbreak of war, the French military aeroplane service was the best in the world. It was mainly composed of Maurice Farman two-seater biplanes and Bleriot monoplanes--the latter type banned for a period on account of a number of serious accidents that took place in 1912. America had its Army Aviation School, and employed Burgess-Wright and Curtiss machines for the most part. In the pre-war years, once the Wright Brothers had accomplished their task, America's chief accomplishment consisted in the development of the 'Flying Boat,' alternatively named with characteristic American clumsiness, 'The Hydro-Aeroplane.' In February of 1911, Glenn Curtiss attached a float to a machine similar to that with which he won the first Gordon-Bennett Air Contest and made his first flying boat experiment. From this beginning he developed the boat form of body which obviated the use and troubles of floats--his hydroplane became its own float. Mainly owing to greater engine reliability the duration records steadily increased. By September of 1912 Fourny, on a Maurice Farman biplane, was able to accomplish a distance of 628 miles without a landing, remaining in the air for 13 hours 17 minutes and just over 57 seconds. By 1914 this was raised by the German aviator, Landemann, to 21 hours 48 3/4 seconds. The nature of this last record shows that the factors in such a record had become mere engine endurance, fuel capacity, and capacity of the pilot to withstand air conditions for a prolonged period, rather than any exceptional flying skill. Let these years be judged by the records they produced, and even then they are rather dull. The glory of achievement such as characterised the work of the Wright Brothers, of Bleriot, and of the giants of the early days, had passed; the splendid courage, the patriotism and devotion of the pilots of the War period had not yet come to being. There was progress, past question, but it was mechanical, hardly ever inspired. The study of climatic conditions was definitely begun and aeronautical meteorology came to being, while another development already noted was the fitting of wireless telegraphy to heavier-than-air machines, as instanced in the British War office specification of February, 1914. These, however, were inevitable; it remained for the War to force development beyond the inevitable, producing in five years that which under normal circumstances might easily have occupied fifty--the aeroplane of to-day; for, as already remarked, there was a deadlock, and any survey that may be made of the years 1912-1914, no matter how superficial, must take it into account with a view to retaining correct perspective in regard to the development of the aeroplane. There is one story of 1914 that must be included, however briefly, in any record of aeronautical achievement, since it demonstrates past question that to Professor Langley really belongs the honour of having achieved a design which would ensure actual flight, although the series of accidents which attended his experiments gave to the Wright Brothers the honour of first leaving the earth and descending without accident in a power-driven heavier-than-air machine. In March, 1914, Glenn Curtiss was invited to send a flying boat to Washington for the celebration of 'Langley Day,' when he remarked, 'I would like to put the Langley aeroplane itself in the air.' In consequence of this remark, Secretary Walcot of the Smithsonian Institution authorised Curtiss to re-canvas the original Langley aeroplane and launch it either under its own power or with a more recent engine and propeller. Curtiss completed this, and had the machine ready on the shores of Lake Keuka, Hammondsport, N.Y., by May. The main object of these renewed trials was to show whether the original Langley machine was capable of sustained free flight with a pilot, and a secondary object was to determine more fully the advantages of the tandem monoplane type; thus the aeroplane was first flown as nearly as possible in its original condition, and then with such modifications as seemed desirable. The only difference made for the first trials consisted in fitting floats with connecting trusses; the steel main frame, wings, rudders, engine, and propellers were substantially as they had been in 1903. The pilot had the same seat under the main frame and the same general system of control. He could raise or lower the craft by moving the rear rudder up and down; he could steer right or left by moving the vertical rudder. He had no ailerons nor wing-warping mechanism, but for lateral balance depended on the dihedral angle of the wings and upon suitable movements of his weight or of the vertical rudder. After the adjustments for actual flight had been made in the Curtiss factory, according to the minute descriptions contained in the Langley Memoir on Mechanical Flight, the aeroplane was taken to the shore of Lake Keuka, beside the Curtiss hangars, and assembled for launching. On a clear morning (May 28th) and in a mild breeze, the craft was lifted on to the water by a dozen men and set going, with Mr Curtiss at the steering wheel, esconced in the little boat-shaped car under the forward part of the frame. The four-winged craft, pointed somewhat across the wind, went skimming over the waveless, then automatically headed into the wind, rose in level poise, soared gracefully for 150 feet, and landed softly on the water near the shore. Mr Curtiss asserted that he could have flown farther, but, being unused to the machine, imagined that the left wings had more resistance than the right. The truth is that the aeroplane was perfectly balanced in wing resistance, but turned on the water like a weather vane, owing to the lateral pressure on its big rear rudder. Hence in future experiments this rudder was made turnable about a vertical axis, as well as about the horizontal axis used by Langley. Henceforth the little vertical rudder under the frame was kept fixed and inactive.[*] That the Langley aeroplane was subsequently fitted with an 80 horse-power Curtiss engine and successfully flown is of little interest in such a record as this, except for the fact that with the weight nearly doubled by the new engine and accessories the machine flew successfully, and demonstrated the perfection of Langley's design by standing the strain. The point that is of most importance is that the design itself proved a success and fully vindicated Langley's work. At the same time, it would be unjust to pass by the fact of the flight without according to Curtiss due recognition of the way in which he paid tribute to the genius of the pioneer by these experiments. [*] Smithsonian Publications No. 2329. XIX. THE WAR PERIOD--I Full record of aeronautical progress and of the accomplishments of pilots in the years of the War would demand not merely a volume, but a complete library, and even then it would be barely possible to pay full tribute to the heroism of pilots of the war period. There are names connected with that period of which the glory will not fade, names such as Bishop, Guynemer, Boelcke, Ball, Fonck, Immelmann, and many others that spring to mind as one recalls the 'Aces' of the period. In addition to the pilots, there is the stupendous development of the machines--stupendous when the length of the period in which it was achieved is considered. The fact that Germany was best prepared in the matter of heavier-than-air service machines in spite of the German faith in the dirigible is one more item of evidence as to who forced hostilities. The Germans came into the field with well over 600 aeroplanes, mainly two-seaters of standardised design, and with factories back in the Fatherland turning out sufficient new machines to make good the losses. There were a few single-seater scouts built for speed, and the two-seater machines were all fitted with cameras and bomb-dropping gear. Manoeuvres had determined in the German mind what should be the uses of the air fleet; there was photography of fortifications and field works; signalling by Very lights; spotting for the guns, and scouting for news of enemy movements. The methodical German mind had arranged all this beforehand, but had not allowed for the fact that opponents might take counter-measures which would upset the over-perfect mechanism of the air service just as effectually as the great march on Paris was countered by the genius of Joffre. The French Air Force at the beginning of the War consisted of upwards of 600 machines. These, unlike the Germans, were not standardised, but were of many and diverse types. In order to get replacements quickly enough, the factories had to work on the designs they had, and thus for a long time after the outbreak of hostilities standardisation was an impossibility. The versatility of a Latin race in a measure compensated for this; from the outset, the Germans tried to overwhelm the French Air Force, but failed, since they had not the numerical superiority, nor--this equally a determining factor--the versatility and resource of the French pilots. They calculated on a 50 per cent superiority to ensure success; they needed more nearly 400 per cent, for the German fought to rule, avoiding risks whenever possible, and definitely instructed to save both machines and pilots wherever possible. French pilots, on the other hand, ran all the risks there were, got news of German movements, bombed the enemy, and rapidly worked up a very respectable antiaircraft force which, whatever it may have accomplished in the way of hitting German planes, got on the German pilots' nerves. It has already been detailed how Britain sent over 82 planes as its contribution to the military aerial force of 1914. These consisted of Farman, Caudron, and Short biplanes, together with Bleriot, Deperdussin and Nieuport monoplanes, certain R.A.F. types, and other machines of which even the name barely survives--the resourceful Yankee entitles them 'orphans.' It is on record that the work of providing spares might have been rather complicated but for the fact that there were none. There is no doubt that the Germans had made study of aerial military needs just as thoroughly as they had perfected their ground organisation. Thus there were 21 illuminated aircraft stations in Germany before the War, the most powerful being at Weimar, where a revolving electric flash of over 27 million candle-power was located. Practically all German aeroplane tests in the period immediately preceding the War were of a military nature, and quite a number of reliability tests were carried out just on the other side of the French frontier. Night flying and landing were standardised items in the German pilot's course of instruction while they were still experimental in other countries, and a system of signals was arranged which rendered the instructional course as perfect as might be. The Belgian contribution consisted of about twenty machines fit for active service and another twenty which were more or less useful as training machines. The material was mainly French, and the Belgian pilots used it to good account until German numbers swamped them. France, and to a small extent England, kept Belgian aviators supplied with machines throughout the War. The Italian Air Fleet was small, and consisted of French machines together with a percentage of planes of Italian origin, of which the design was very much a copy of French types. It was not until the War was nearing its end that the military and naval services relied more on the home product than on imports. This does not apply to engines, however, for the F.I.A.T. and S.C.A.T. were equal to practically any engine of Allied make, both in design and construction. Russia spent vast sums in the provision of machines: the giant Sikorsky biplane, carrying four 100 horsepower Argus motors, was designed by a young Russian engineer in the latter part of 1913, and in its early trials it created a world's record by carrying seven passengers for 1 hour 54 minutes. Sikorsky also designed several smaller machines, tractor biplanes on the lines of the British B.E. type, which were very successful. These were the only home productions, and the imports consisted mainly of French aeroplanes by the hundred, which got as far as the docks and railway sidings and stayed there, while German influence and the corruption that ruined the Russian Army helped to lose the War. A few Russian aircraft factories were got into operation as hostilities proceeded, but their products were negligible, and it is not on record that Russia ever learned to manufacture a magneto. The United States paid tribute to British efficiency by adopting the British system of training for its pilots; 500 American cadets were trained at the School of Military Aeronautics at oxford, in order to form a nucleus for the American aviation schools which were subsequently set up in the United States and in France. As regards production of craft, the designing of the Liberty engine and building of over 20,000 aeroplanes within a year proves that America is a manufacturing country, even under the strain of war. There were three years of struggle for aerial supremacy, the combatants being England and France against Germany, and the contest was neck and neck all the way. Germany led at the outset with the standardised two-seater biplanes manned by pilots and observers, whose training was superior to that afforded by any other nation, while the machines themselves were better equipped and fitted with accessories. All the early German aeroplanes were designated Taube by the uninitiated, and were formed with swept-back, curved wings very much resembling the wings of a bird. These had obvious disadvantages, but the standardisation of design and mass production of the German factories kept them in the field for a considerable period, and they flew side by side with tractor biplanes of improved design. For a little time, the Fokker monoplane became a definite threat both to French and British machines. It was an improvement on the Morane French monoplane, and with a high-powered engine it climbed quickly and flew fast, doing a good deal of damage for a brief period of 1915. Allied design got ahead of it and finally drove it out of the air. German equipment at the outset, which put the Allies at a disadvantage, included a hand-operated magneto engine-starter and a small independent screw which, mounted on one of the main planes, drove the dynamo used for the wireless set. Cameras were fitted on practically every machine; equipment included accurate compasses and pressure petrol gauges, speed and height recording instruments, bomb-dropping fittings and sectional radiators which facilitated repairs and gave maximum engine efficiency in spite of variations of temperature. As counter to these, the Allied pilots had resource amounting to impudence. In the early days they carried rifles and hand grenades and automatic pistols. They loaded their machines down, often at their own expense, with accessories and fittings until their aeroplanes earned their title of Christmas trees. They played with death in a way that shocked the average German pilot of the War's early stages, declining to fight according to rule and indulging in the individual duels of the air which the German hated. As Sir John French put it in one of his reports, they established a personal ascendancy over the enemy, and in this way compensated for their inferior material. French diversity of design fitted in well with the initiative and resource displayed by the French pilots. The big Caudron type was the ideal bomber of the early days; Farman machines were excellent for reconnaissance and artillery spotting; the Bleriots proved excellent as fighting scouts and for aerial photography; the Nieuports made good fighters, as did the Spads, both being very fast craft, as were the Morane-Saulnier monoplanes, while the big Voisin biplanes rivalled the Caudron machines as bombers. The day of the Fokker ended when the British B.E.2.C. aeroplane came to France in good quantities, and the F.E. type, together with the De Havilland machines, rendered British aerial superiority a certainty. Germany's best reply--this was about 1916--was the Albatross biplane, which was used by Captain Baron von Richthofen for his famous travelling circus, manned by German star pilots and sent to various parts of the line to hearten up German troops and aviators after any specially bad strafe. Then there were the Aviatik biplane and the Halberstadt fighting scout, a cleanly built and very fast machine with a powerful engine with which Germany tried to win back superiority in the third year of the War, but Allied design kept about three months ahead of that of the enemy, once the Fokker had been mastered, and the race went on. Spads and Bristol fighters, Sopwith scouts and F.E.'s played their part in the race, and design was still advancing when peace came. The giant twin-engined Handley-Page bomber was tried out, proved efficient, and justly considered better than anything of its kind that had previously taken the field. Immediately after the conclusion of its trials, a specimen of the type was delivered intact at Lille for the Germans to copy, the innocent pilot responsible for the delivery doing some great disservice to his own cause. The Gotha Wagon-Fabrik Firm immediately set to work and copied the Handley-Page design, producing the great Gotha bombing machine which was used in all the later raids on England as well as for night work over the Allied lines. How the War advanced design may be judged by comparison of the military requirements given for the British Military Trials of 1912, with performances of 1916 and 1917, when the speed of the faster machines had increased to over 150 miles an hour and Allied machines engaged enemy aircraft at heights ranging up to 22,000 feet. All pre-war records of endurance, speed, and climb went by the board, as the race for aerial superiority went on. Bombing brought to being a number of crude devices in the first year of the War. Allied pilots of the very early days carried up bombs packed in a small box and threw them over by hand, while, a little later, the bombs were strung like apples on wings and undercarriage, so that the pilot who did not get rid of his load before landing risked an explosion. Then came a properly designed carrying apparatus, crude but fairly efficient, and with 1916 development had proceeded as far as the proper bomb-racks with releasing gear. Reconnaissance work developed, so that fighting machines went as escort to observing squadrons and scouting operations were undertaken up to 100 miles behind the enemy lines; out of this grew the art of camouflage, when ammunition dumps were painted to resemble herds of cows, guns were screened by foliage or painted to merge into a ground scheme, and many other schemes were devised to prevent aerial observation. Troops were moved by night for the most part, owing to the keen eyes of the air pilots and the danger of bombs, though occasionally the aviator had his chance. There is one story concerning a British pilot who, on returning from a reconnaissance flight, observed a German Staff car on the road under him; he descended and bombed and machine--gunned the car until the German General and his chauffeur abandoned it, took to their heels, and ran like rabbits. Later still, when Allied air superiority was assured, there came the phase of machine-gunning bodies of enemy troops from the air. Disregarding all antiaircraft measures, machines would sweep down and throw battalions into panic or upset the military traffic along a road, demoralising a battery or a transport train and causing as much damage through congestion of traffic as with their actual machine-gun fire. Aerial photography, too, became a fine art; the ordinary long focus cameras were used at the outset with automatic plate changers, but later on photographing aeroplanes had cameras of wide angle lens type built into the fuselage. These were very simply operated, one lever registering the exposure and changing the plate. In many cases, aerial photographs gave information which the human eye had missed, and it is noteworthy that photographs of ground showed when troops had marched over it, while the aerial observer was quite unable to detect the marks left by their passing. Some small mention must be made of seaplane activities, which, round the European coasts involved in the War, never ceased. The submarine campaign found in the spotting seaplane its greatest deterrent, and it is old news now how even the deeply submerged submarines were easily picked out for destruction from a height and the news wirelessed from seaplane to destroyer, while in more than one place the seaplane itself finished the task by bomb dropping. It was a seaplane that gave Admiral Beatty the news that the whole German Fleet was out before the Jutland Battle, news which led to a change of plans that very nearly brought about the destruction of Germany's naval power. For the most part, the seaplanes of the War period were heavier than the land machines and, in the opinion of the land pilots, were slow and clumsy things to fly. This was inevitable, for their work demanded more solid building and greater reliability. To put the matter into Hibernian phrase, a forced landing at sea is a much more serious matter than on the ground. Thus there was need for greater engine power, bigger wingspread to support the floats, and fuel tanks of greater capacity. The flying boats of the later War period carried considerable crews, were heavily armed, capable of withstanding very heavy weather, and carried good loads of bombs on long cruises. Their work was not all essentially seaplane work, for the R.N.A.S. was as well known as hated over the German airship sheds in Belgium and along the Flanders coast. As regards other theatres of War, they rendered valuable service from the Dardanelles to the Rufiji River, at this latter place forming a principal factor in the destruction of the cruiser Konigsberg. Their spotting work at the Dardanelles for the battleships was responsible for direct hits from 15 in. guns on invisible targets at ranges of over 12,000 yards. Seaplane pilots were bombing specialists, including among their targets army headquarters, ammunition dumps, railway stations, submarines and their bases, docks, shipping in German harbours, and the German Fleet at Wilhelmshaven. Dunkirk, a British seaplane base, was a sharp thorn in the German side. Turning from consideration of the various services to the exploits of the men composing them, it is difficult to particularise. A certain inevitable prejudice even at this length of time leads one to discount the valour of pilots in the German Air Service, but the names of Boelcke, von Richthofen, and Immelmann recur as proof of the courage that was not wanting in the enemy ranks, while, however much we may decry the Gotha raids over the English coast and on London, there is no doubt that the men who undertook these raids were not deficient in the form of bravery that is of more value than the unthinking valour of a minute which, observed from the right quarter, wins a military decoration. Yet the fact that the Allied airmen kept the air at all in the early days proved on which side personal superiority lay, for they were outnumbered, out-manoeuvred, and faced by better material than any that they themselves possessed; yet they won their fights or died. The stories of their deeds are endless; Bishop, flying alone and meeting seven German machines and crashing four; the battle of May 5th, 1915, when five heroes fought and conquered twenty-seven German machines, ranging in altitude between 12,000 and 3,000 feet, and continuing the extraordinary struggle from five until six in the evening. Captain Aizlewood, attacking five enemy machines with such reckless speed that he rammed one and still reached his aerodrome safely--these are items in a long list of feats of which the character can only be realised when it is fully comprehended that the British Air Service accounted for some 8,000 enemy machines in the course of the War. Among the French there was Captain Guynemer, who at the time of his death had brought down fifty-four enemy machines, in addition to many others of which the destruction could not be officially confirmed. There was Fonck, who brought down six machines in one day, four of them within two minutes. There are incredible stories, true as incredible, of shattered men carrying on with their work in absolute disregard of physical injury. Major Brabazon Rees, V.C., engaged a big German battle-plane in September of 1915 and, single-handed, forced his enemy out of action. Later in his career, with a serious wound in the thigh from which blood was pouring, he kept up a fight with an enemy formation until he had not a round of ammunition left, and then returned to his aerodrome to get his wound dressed. Lieutenants Otley and Dunning, flying in the Balkans, engaged a couple of enemy machines and drove them off, but not until their petrol tank had got a hole in it and Dunning was dangerously wounded in the leg. Otley improvised a tourniquet, passed it to Dunning, and, when the latter had bandaged himself, changed from the observer's to the pilot's seat, plugged the bullet hole in the tank with his thumb and steered the machine home. These are incidents; the full list has not been, and can never be recorded, but it goes to show that in the pilot of the War period there came to being a new type of humanity, a product of evolution which fitted a certain need. Of such was Captain West, who, engaging hostile troops, was attacked by seven machines. Early in the engagement, one of his legs was partially severed by an explosive bullet and fell powerless into the controls, rendering the machine for the time unmanageable. Lifting his disabled leg, he regained control of the machine, and although wounded in the other leg, he manoeuvred his machine so skilfully that his observer was able to get several good bursts into the enemy machines, driving them away. Then, desperately wounded as he was, Captain West brought the machine over to his own lines and landed safely. He fainted from loss of blood and exhaustion, but on regaining consciousness, insisted on writing his report. Equal to this was the exploit of Captain Barker, who, in aerial combat, was wounded in the right and left thigh and had his left arm shattered, subsequently bringing down an enemy machine in flames, and then breaking through another hostile formation and reaching the British lines. In recalling such exploits as these, one is tempted on and on, for it seems that the pilots rivalled each other in their devotion to duty, this not confined to British aviators, but common practically to all services. Sufficient instances have been given to show the nature of the work and the character of the men who did it. The rapid growth of aerial effort rendered it necessary in January of 1915 to organise the Royal Flying Corps into separate wings, and in October of the same year it was constituted in Brigades. In 1916 the Air Board was formed, mainly with the object of co-ordinating effort and ensuring both to the R.N.A.S. and to the R.F.C. adequate supplies of material as far as construction admitted. Under the presidency of Lord Cowdray, the Air Board brought about certain reforms early in 1917, and in November of that year a separate Air Ministry was constituted, separating the Air Force from both Navy and Army, and rendering it an independent force. On April 1st, 1918, the Royal Air Force came into existence, and unkind critics in the Royal Flying Corps remarked on the appropriateness of the date. At the end of the War, the personnel of the Royal Air Force amounted to 27,906 officers, and 263,842 other ranks. Contrast of these figures with the number of officers and men who took the field in 1914 is indicative of the magnitude of British aerial effort in the War period. XX. THE WAR PERIOD--II There was when War broke out no realisation on the part of the British Government of the need for encouraging the enterprise of private builders, who carried out their work entirely at their-own cost. The importance of a supply of British-built engines was realised before the War, it is true, and a competition was held in which a prize of L5,000 was offered for the best British engine, but this awakening was so late that the R.F.C. took the field without a single British power plant. Although Germany woke up equally late to the need for home produced aeroplane engines, the experience gained in building engines for dirigibles sufficed for the production of aeroplane power plants. The Mercedes filled all requirements together with the Benz and the Maybach. There was a 225 horsepower Benz which was very popular, as were the 100 horse-power and 170 horse-power Mercedes, the last mentioned fitted to the Aviatik biplane of 1917. The Uberursel was a copy of the Gnome and supplied the need for rotary engines. In Great Britain there were a number of aeroplane constructing firms that had managed to emerge from the lean years 1912-1913 with sufficient manufacturing plant to give a hand in making up the leeway of construction when War broke out. Gradually the motor-car firms came in, turning their body-building departments to plane and fuselage construction, which enabled them to turn out the complete planes engined and ready for the field. The coach-building trade soon joined in and came in handy as propeller makers; big upholstering and furniture firms and scores of concerns that had never dreamed of engaging in aeroplane construction were busy on supplying the R.F.C. By 1915 hundreds of different firms were building aeroplanes and parts; by 1917 the number had increased to over 1,000, and a capital of over a million pounds for a firm that at the outbreak of War had employed a score or so of hands was by no means uncommon. Women and girls came into the work, more especially in plane construction and covering and doping, though they took their place in the engine shops and proved successful at acetylene welding and work at the lathes. It was some time before Britain was able to provide its own magnetos, for this key industry had been left in the hands of the Germans up to the outbreak of War, and the 'Bosch' was admittedly supreme--even now it has never been beaten, and can only be equalled, being as near perfection as is possible for a magneto. One of the great inventions of the War was the synchronisation of engine-timing and machine gun, which rendered it possible to fire through the blades of a propeller without damaging them, though the growing efficiency of the aeroplane as a whole and of its armament is a thing to marvel at on looking back and considering what was actually accomplished. As the efficiency of the aeroplane increased, so anti-aircraft guns and range-finding were improved. Before the War an aeroplane travelling at full speed was reckoned perfectly safe at 4,000 feet, but, by the first month of 1915, the safe height had gone up to 9,000 feet, 7,000 feet being the limit of rifle and machine gun bullet trajectory; the heavier guns were not sufficiently mobile to tackle aircraft. At that time, it was reckoned that effective aerial photography ceased at 6,000 feet, while bomb-dropping from 7,000-8,000 feet was reckoned uncertain except in the case of a very large target. The improvement in anti-aircraft devices went on, and by May of 1916, an aeroplane was not safe under 15,000 feet, while anti-aircraft shells had fuses capable of being set to over 20,000 feet, and bombing from 15,000 and 16,000 feet was common. It was not till later that Allied pilots demonstrated the safety that lies in flying very near the ground, this owing to the fact that, when flying swiftly at a very low altitude, the machine is out of sight almost before it can be aimed at. The Battle of the Somme and the clearing of the air preliminary to that operation brought the fighting aeroplane pure and simple with them. Formations of fighting planes preceded reconnaissance craft in order to clear German machines and observation balloons out of the sky and to watch and keep down any further enemy formations that might attempt to interfere with Allied observation work. The German reply to this consisted in the formation of the Flying Circus, of which Captain Baron von Richthofen's was a good example. Each circus consisted of a large formation of speedy machines, built specially for fighting and manned by the best of the German pilots. These were sent to attack at any point along the line where the Allies had got a decided superiority. The trick flying of pre-war days soon became an everyday matter; Pegoud astonished the aviation world before the War by first looping the loop, but, before three years of hostilities had elapsed, looping was part of the training of practically every pilot, while the spinning nose dive, originally considered fatal, was mastered, and the tail slide, which consisted of a machine rising nose upward in the air and falling back on its tail, became one of the easiest 'stunts' in the pilot's repertoire. Inherent stability was gradually improved, and, from 1916 onward, practically every pilot could carry on with his machine-gun or camera and trust to his machine to fly itself until he was free to attend to it. There was more than one story of a machine coming safely to earth and making good landing on its own account with the pilot dead in his cock-pit. Toward the end of the War, the Independent Air Force was formed as a branch of the R.A.F. with a view to bombing German bases and devoting its attention exclusively to work behind the enemy lines. Bombing operations were undertaken by the R.N.A.S. as early as 1914-1915 against Cuxhaven, Dusseldorf, and Friedrichshavn, but the supply of material was not sufficient to render these raids continuous. A separate Brigade, the 8th, was formed in 1917 to harass the German chemical and iron industries, the base being in the Nancy area, and this policy was found so fruitful that the Independent Force was constituted on the 8th June, 1918. The value of the work accomplished by this force is demonstrated by the fact that the German High Command recalled twenty fighting squadrons from the Western front to counter its activities, and, in addition, took troops away from the fighting line in large numbers for manning anti-aircraft batteries and searchlights. The German press of the last year of the War is eloquent of the damage done in manufacturing areas by the Independent Force, which, had hostilities continued a little longer, would have included Berlin in its activities. Formation flying was first developed by the Germans, who made use of it in the daylight raids against England in 1917. Its value was very soon realised, and the V formation of wild geese was adopted, the leader taking the point of the V and his squadron following on either side at different heights. The air currents set up by the leading machines were thus avoided by those in the rear, while each pilot had a good view of the leader's bombs, and were able to correct their own aim by the bursts, while the different heights at which they flew rendered anti-aircraft gun practice less effective. Further, machines were able to afford mutual protection to each other and any attacker would be met by machine-gun fire from three or four machines firing on him from different angles and heights. In the later formations single-seater fighters flew above the bombers for the purpose of driving off hostile craft. Formation flying was not fully developed when the end of the War brought stagnation in place of the rapid advance in the strategy and tactics of military air work. XXI. RECONSTRUCTION The end of the War brought a pause in which the multitude of aircraft constructors found themselves faced with the possible complete stagnation of the industry, since military activities no longer demanded their services and the prospects of commercial flying were virtually nil. That great factor in commercial success, cost of plant and upkeep, had received no consideration whatever in the War period, for armies do not count cost. The types of machines that had evolved from the War were very fast, very efficient, and very expensive, although the bombers showed promise of adaptation to commercial needs, and, so far as other machines were concerned, America had already proved the possibilities of mail-carrying by maintaining a mail service even during the War period. A civil aviation department of the Air Ministry was formed in February of 1919 with a Controller General of Civil Aviation at the head. This was organised into four branches, one dealing with the survey and preparation of air routes for the British Empire, one organising meteorological and wireless telegraphy services, one dealing with the licensing of aerodromes, machines for passenger or goods carrying and civilian pilots, and one dealing with publicity and transmission of information generally. A special Act of Parliament 264 entitled 'The Air Navigation Acts, 1911-1919,' was passed on February 27th, and commercial flying was officially permitted from May 1st, 1919. Meanwhile the great event of 1919, the crossing of the Atlantic by air, was gradually ripening to performance. In addition to the rigid airship, R.34, eight machines entered for this flight, these being a Short seaplane, Handley-Page, Martinsyde, Vickers-Vimy, and Sopwith aeroplanes, and three American flying boats, N.C.1, N.C.3, and N.C.4. The Short seaplane was the only one of the eight which proposed to make the journey westward; in flying from England to Ireland, before starting on the long trip to Newfoundland, it fell into the sea off the coast of Anglesey, and so far as it was concerned the attempt was abandoned. The first machines to start from the Western end were the three American seaplanes, which on the morning of May 6th left Trepassy, Newfoundland, on the 1,380 mile stage to Horta in the Azores. N.C.1 and N.C.3 gave up the attempt very early, but N.C.4, piloted by Lieut.-Commander Read, U.S.N., made Horta on May 17th and made a three days' halt. On the 20th the second stage of the journey to Ponta Delgada, a further 190 miles, was completed and a second halt of a week was made. On the 27th, the machine left for Lisbon, 900 miles distant, and completed the journey in a day. On the 30th a further stage of 340 miles took N.C.4 on to Ferrol, and the next day the last stage of 420 miles to Plymouth was accomplished. Meanwhile, H. G. Hawker, pilot of the Sopwith biplane, together with Commander Mackenzie Grieve, R.N., his navigator, found the weather sufficiently auspicious to set out at 6.48 p.m. On Sunday, May 18th, in the hope of completing the trip by the direct route before N.C.4 could reach Plymouth. They set out from Mount Pearl aerodrome, St John's, Newfoundland, and vanished into space, being given up as lost, as Hamel was lost immediately before the War in attempting to fly the North Sea. There was a week of dead silence regarding their fate, but on the following Sunday morning there was world-wide relief at the news that the plucky attempt had not ended in disaster, but both aviators had been picked up by the steamer Mary at 9.30 a.m. on the morning of the 19th, while still about 750 miles short of the conclusion of their journey. Engine failure brought them down, and they planed down to the sea close to the Mary to be picked up; as the vessel was not fitted with wireless, the news of their rescue could not be communicated until land was reached. An equivalent of half the L10,000 prize offered by the Daily Mail for the non-stop flight was presented by the paper in recognition of the very gallant attempt, and the King conferred the Air Force Cross on both pilot and navigator. Raynham, pilot of the Martinsyde competing machine, had the bad luck to crash his craft twice in attempting to start before he got outside the boundary of the aerodrome. The Handley-Page machine was withdrawn from the competition, and, attempting to fly to America, was crashed on the way. The first non-stop crossing was made on June 14th-15th in 16 hours 27 minutes, the speed being just over 117 miles per hour. The machine was a Vickers-Vimy bomber, engined with two Rolls-Royce Eagle VIII's, piloted by Captain John Alcock, D.S.C., with Lieut. Arthur Whitten-Brown as navigator. The journey was reported to be very rough, so much so at times that Captain Alcock stated that they were flying upside down, and for the greater part of the time they were out of sight of the sea. Both pilot and navigator had the honour of knighthood conferred on them at the conclusion of the journey. Meanwhile, commercial flying opened on May 8th (the official date was May 1st) with a joy-ride service from Hounslow of Avro training machines. The enterprise caught on remarkably, and the company extended their activities to coastal resorts for the holiday season--at Blackpool alone they took up 10,000 passengers before the service was two months old. Hendon, beginning passenger flights on the same date, went in for exhibition and passenger flying, and on June 21st the aerial Derby was won by Captain Gathergood on an Airco 4R machine with a Napier 450 horse-power 'Lion' engine; incidentally the speed of 129.3 miles per hour was officially recognised as constituting the world's record for speed within a closed circuit. On July 17th a Fiat B.R. biplane with a 700 horse-power engine landed at Kenley aerodrome after having made a non-stop flight of 1,100 miles. The maximum speed of this machine was 160 miles per hour, and it was claimed to be the fastest machine in existence. On August 25th a daily service between London and Paris was inaugurated by the Aircraft Manufacturing Company, Limited, who ran a machine each way each day, starting at 12.30 and due to arrive at 2.45 p.m. The Handley-Page Company began a similar service in September of 1919, but ran it on alternate days with machines capable of accommodating ten passengers. The single fare in each case was fixed at 15 guineas and the parcel rate at 7s. 6d. per pound. Meanwhile, in Germany, a number of passenger services had been in operation from the early part of the year; the Berlin-Weimar service was established on February 5th and Berlin-Hamburg on March 1st, both for mail and passenger carrying. Berlin-Breslau was soon added, but the first route opened remained most popular, 538 flights being made between its opening and the end of April, while for March and April combined, the Hamburg-Berlin route recorded only 262 flights. All three routes were operated by a combine of German aeronautical firms entitled the Deutsch Luft Rederie. The single fare between Hamburg and Berlin was 450 marks, between Berlin and Breslau 500 marks, and between Berlin and Weimar 450 marks. Luggage was carried free of charge, but varied according to the weight of the passenger, since the combined weight of both passenger and luggage was not allowed to exceed a certain limit. In America commercial flying had begun in May of 1918 with the mail service between Washington, Philadelphia, and New York, which proved that mail carrying is a commercial possibility, and also demonstrated the remarkable reliability of the modern aeroplane by making 102 complete flights out of a possible total of 104 in November, 1918, at a cost of 0.777 of a dollar per mile. By March of 1919 the cost per mile had gone up to 1.28 dollars; the first annual report issued at the end of May showed an efficiency of 95.6 per cent and the original six aeroplanes and engines with which the service began were still in regular use. In June of 1919 an American commercial firm chartered an aeroplane for emergency service owing to a New York harbour strike and found it so useful that they made it a regular service. The Travellers Company inaugurated a passenger flying boat service between New York and Atlantic City on July 25th, the fare, inclusive of 35 lbs. of luggage, being fixed at L25 each way. Five flights on the American continent up to the end of 1919 are worthy of note. On December 13th, 1918, Lieut. D. Godoy of the Chilian army left Santiago, Chili, crossed the Andes at a height of 19,700 feet and landed at Mendoza, the capital of the wine-growing province of Argentina. On April 19th, 1919, Captain E. F. White made the first non-stop flight between New York and Chicago in 6 hours 50 minutes on a D.H.4 machine driven by a twelve-cylinder Liberty engine. Early in August Major Schroeder, piloting a French Lepere machine flying at a height of 18,400 feet, reached a speed of 137 miles per hour with a Liberty motor fitted with a super-charger. Toward the end of August, Rex Marshall, on a Thomas-Morse biplane, starting from a height of 17,000 feet, made a glide of 35 miles with his engine cut off, restarting it when at a height of 600 feet above the ground. About a month later R. Rohlfe, piloting a Curtiss triplane, broke the height record by reaching 34,610 feet. XXII. 1919-20 Into the later months of 1919 comes the flight by Captain Ross-Smith from England to Australia and the attempt to make the Cape to Cairo voyage by air. The Australian Government had offered a prize of L10,000 for the first flight from England to Australia in a British machine, the flight to be accomplished in 720 consecutive hours. Ross-Smith, with his brother, Lieut. Keith Macpherson Smith, and two mechanics, left Hounslow in a Vickers-Vimy bomber with Rolls-Royce engine on November 12th and arrived at Port Darwin, North Australia, on the 10th December, having completed the flight in 27 days 20 hours 20 minutes, thus having 51 hours 40 minutes to spare out of the 720 allotted hours. Early in 1920 came a series of attempts at completing the journey by air between Cairo and the Cape. Out of four competitors Colonel Van Ryneveld came nearest to making the journey successfully, leaving England on a standard Vickers-Vimy bomber with Rolls-Royce engines, identical in design with the machine used by Captain Ross-Smith on the England to Australia flight. A second Vickers-Vimy was financed by the Times newspaper and a third flight was undertaken with a Handley-Page machine under the auspices of the Daily Telegraph. The Air Ministry had already prepared the route by means of three survey parties which cleared the aerodromes and landing grounds, dividing their journey into stages of 200 miles or less. Not one of the competitors completed the course, but in both this and Ross-Smith's flight valuable data was gained in respect of reliability of machines and engines, together with a mass of meteorological information. The Handley-Page Company announced in the early months of 1920 that they had perfected a new design of wing which brought about a twenty to forty per cent improvement in lift rate in the year. When the nature of the design was made public, it was seen to consist of a division of the wing into small sections, each with its separate lift. A few days later, Fokker, the Dutch inventor, announced the construction of a machine in which all external bracing wires are obviated, the wings being of a very deep section and self-supporting. The value of these two inventions remains to be seen so far as commercial flying is concerned. The value of air work in war, especially so far as the Colonial campaigns in which British troops are constantly being engaged is in question, was very thoroughly demonstrated in a report issued early in 1920 with reference to the successful termination of the Somaliland campaign through the intervention of the Royal Air Force, which between January 21st and the 31st practically destroyed the Dervish force under the Mullah, which had been a thorn in the side of Britain since 1907. Bombs and machine-guns did the work, destroying fortifications and bringing about the surrender of all the Mullah's following, with the exception of about seventy who made their escape. Certain records both in construction and performance had characterised the post-war years, though as design advances and comes nearer to perfection, it is obvious that records must get fewer and farther between. The record aeroplane as regards size at the time of its construction was the Tarrant triplane, which made its first--and last--flight on May 28th, 1919. The total loaded weight was 30 tons, and the machine was fitted with six 400 horse-power engines; almost immediately after the trial flight began, the machine pitched forward on its nose and was wrecked, causing fatal injuries to Captains Dunn and Rawlings, who were aboard the machine. A second accident of similar character was that which befell the giant seaplane known as the Felixstowe Fury, in a trial flight. This latter machine was intended to be flown to Australia, but was crashed over the water. On May 4th, 1920, a British record for flight duration and useful load was established by a commercial type Handley-Page biplane, which, carrying a load of 3,690 lbs., rose to a height of 13,999 feet and remained in the air for 1 hour 20 minutes. On May 27th the French pilot, Fronval, flying at Villacoublay in a Morane-Saulnier type of biplane with Le Rhone motor, put up an extraordinary type of record by looping the loop 962 times in 3 hours 52 minutes 10 seconds. Another record of the year of similar nature was that of two French fliers, Boussotrot and Bernard, who achieved a continuous flight of 24 hours 19 minutes 7 seconds, beating the pre-war record of 21 hours 48 3/4 seconds set up by the German pilot, Landemann. Both these records are likely to stand, being in the nature of freaks, which demonstrate little beyond the reliability of the machine and the capacity for endurance on the part of its pilots. Meanwhile, on February 14th, Lieuts. Masiero and Ferrarin left Rome on S.V.A. Ansaldo V. machines fitted with 220 horse-power S.V.A. motors. On May 30th they arrived at Tokio, having flown by way of Bagdad, Karachi, Canton, Pekin, and Osaka. Several other competitors started, two of whom were shot down by Arabs in Mesopotamia. Considered in a general way, the first two years after the termination of the Great European War form a period of transition in which the commercial type of aeroplane was gradually evolved from the fighting machine which was perfected in the four preceding years. There was about this period no sense of finality, but it was as experimental, in its own way, as were the years of progressing design which preceded the war period. Such commercial schemes as were inaugurated call for no more note than has been given here; they have been experimental, and, with the possible exception of the United States Government mail service, have not been planned and executed on a sufficiently large scale to furnish reliable data on which to forecast the prospects of commercial aviation. And there is a school rapidly growing up which asserts that the day of aeroplanes is nearly over. The construction of the giant airships of to-day and the successful return flight of R34 across the Atlantic seem to point to the eventual triumph, in spite of its disadvantages, of the dirigible airship. This is a hard saying for such of the aeroplane industry as survived the War period and consolidated itself, and it is but the saying of a section which bases its belief on the fact that, as was noted in the very early years of the century, the aeroplane is primarily a war machine. Moreover, the experience of the War period tended to discredit the dirigible, since, before the introduction of helium gas, the inflammability of its buoyant factor placed it at an immense disadvantage beside the machine dependent on the atmosphere itself for its lift. As life runs to-day, it is a long time since Kipling wrote his story of the airways of a future world and thrust out a prophecy that the bulk of the world's air traffic would be carried by gas-bag vessels. If the school which inclines to belief in the dirigible is right in its belief, as it well may be, then the foresight was uncannily correct, not only in the matter of the main assumption, but in the detail with which the writer embroidered it. On the constructional side, the history of the aeroplane is still so much in the making that any attempt at a critical history would be unwise, and it is possible only to record fact, leaving it to the future for judgment to be passed. But, in a general way, criticism may be advanced with regard to the place that aeronautics takes in civilisation. In the past hundred years, the world has made miraculously rapid strides materially, but moral development has not kept abreast. Conception of the responsibilities of humanity remains virtually in a position of a hundred years ago; given a higher conception of life and its responsibilities, the aeroplane becomes the crowning achievement of that long series which James Watt inaugurated, the last step in intercommunication, the chain with which all nations are bound in a growing prosperity, surely based on moral wellbeing. Without such conception of the duties as well as the rights of life, this last achievement of science may yet prove the weapon that shall end civilisation as men know it to-day, and bring this ultra-material age to a phase of ruin on which saner people can build a world more reasonable and less given to groping after purely material advancement. PART II. 1903-1920: PROGRESS IN DESIGN By Lieut.-Col. W. Lockwood Marsh I. THE BEGINNINGS Although the first actual flight of an aeroplane was made by the Wrights on December 17th 1903, it is necessary, in considering the progress of design between that period and the present day, to go back to the earlier days of their experiments with 'gliders,' which show the alterations in design made by them in their step-bystep progress to a flying machine proper, and give a clear idea of the stage at which they had arrived in the art of aeroplane design at the time of their first flights. They started by carefully surveying the work of previous experimenters, such as Lilienthal and Chanute, and from the lesson of some of the failures of these pioneers evolved certain new principles which were embodied in their first glider, built in 1900. In the first place, instead of relying upon the shifting of the operator's body to obtain balance, which had proved too slow to be reliable, they fitted in front of the main supporting surfaces what we now call an 'elevator,' which could be flexed, to control the longitudinal balance, from where the operator lay prone upon the main supporting surfaces. The second main innovation which they incorporated in this first glider, and the principle of which is still used in every aeroplane in existence, was the attainment of lateral balance by warping the extremities of the main planes. The effect of warping or pulling down the extremity of the wing on one side was to increase its lift and so cause that side to rise. In the first two gliders this control was also used for steering to right and left. Both these methods of control were novel for other than model work, as previous experimenters, such as Lilienthal and Pilcher, had relied entirely upon moving the legs or shifting the position of the body to control the longitudinal and lateral motions of their gliders. For the main supporting surfaces of the glider the biplane system of Chanute's gliders was adopted with certain modifications, while the curve of the wings was founded upon the calculations of Lilienthal as to wind pressure and consequent lift of the plane. This first glider was tested on the Kill Devil Hill sand-hills in North Carolina in the summer of 1900 and proved at any rate the correctness of the principles of the front elevator and warping wings, though its designers were puzzled by the fact that the lift was less than they expected; whilst the 'drag'(as we call it), or resistance, was also considerably lower than their predictions. The 1901 machine was, in consequence, nearly doubled in area--the lifting surface being increased from 165 to 308 square feet--the first trial taking place on July 27th, 1901, again at Kill Devil Hill. It immediately appeared that something was wrong, as the machine dived straight to the ground, and it was only after the operator's position had been moved nearly a foot back from what had been calculated as the correct position that the machine would glide--and even then the elevator had to be used far more strongly than in the previous year's glider. After a good deal of thought the apparent solution of the trouble was finally found. This consisted in the fact that with curved surfaces, while at large angles the centre of pressure moves forward as the angle decreases, when a certain limit of angle is reached it travels suddenly backwards and causes the machine to dive. The Wrights had known of this tendency from Lilienthal's researches, but had imagined that the phenomenon would disappear if they used a fairly lightly cambered--or curved--surface with a very abrupt curve at the front. Having discovered what appeared to be the cause they surmounted the difficulty by 'trussing down' the camber of the wings, with the result that they at once got back to the old conditions of the previous year and could control the machine readily with small movements of the elevator, even being able to follow undulations in the ground. They still found, however, that the lift was not as great as it should have been; while the drag remained, as in the previous glider, surprisingly small. This threw doubt on previous figures as to wind resistance and pressure on curved surfaces; but at the same time confirmed (and this was a most important result) Lilienthal's previously questioned theory that at small angles the pressure on a curved surface instead of being normal, or at right angles to, the chord is in fact inclined in front of the perpendicular. The result of this is that the pressure actually tends to draw the machine forward into the wind--hence the small amount of drag, which had puzzled Wilbur and Orville Wright. Another lesson which was learnt from these first two years of experiment, was that where, as in a biplane, two surfaces are superposed one above the other, each of them has somewhat less lift than it would have if used alone. The experimenters were also still in doubt as to the efficiency of the warping method of controlling the lateral balance as it gave rise to certain phenomena which puzzled them, the machine turning towards the wing having the greater angle, which seemed also to touch the ground first, contrary to their expectations. Accordingly, on returning to Dayton towards the end of 1901, they set themselves to solve the various problems which had appeared and started on a lengthy series of experiments to check the previous figures as to wind resistance and lift of curved surfaces, besides setting themselves to grapple with the difficulty of lateral control. They accordingly constructed for themselves at their home in Dayton a wind tunnel 16 inches square by 6 feet long in which they measured the lift and 'drag' of more than two hundred miniature wings. In the course of these tests they for the first time produced comparative results of the lift of oblong and square surfaces, with the result that they re-discovered the importance of 'aspect ratio'--the ratio of length to breadth of planes. As a result, in the next year's glider the aspect ration of the wings was increased from the three to one of the earliest model to about six to one, which is approximately the same as that used in the machines of to-day. Further than that, they discussed the question of lateral stability, and came to the conclusion that the cause of the trouble was that the effect of warping down one wing was to increase the resistance of, and consequently slow down, that wing to such an extent that its lift was reduced sufficiently to wipe out the anticipated increase in lift resulting from the warping. From this they deduced that if the speed of the warped wing could be controlled the advantage of increasing the angle by warping could be utilised as they originally intended. They therefore decided to fit a vertical fin at the rear which, if the machine attempted to turn, would be exposed more and more to the wind and so stop the turning motion by offering increased resistance. As a result of this laboratory research work the third Wright glider, which was taken to Kill Devil Hill in September, 1902, was far more efficient aerodynamically than either of its two predecessors, and was fitted with a fixed vertical fin at the rear in addition to the movable elevator in front. According to Mr Griffith Brewer,[*] this third glider contained 305 square feet of surface; though there may possibly be a mistake here, as he states[**] the surface of the previous year's glider to have been only 290 square feet, whereas Wilbur Wright himself[***] states it to have been 308 square feet. The matter is not, perhaps, save historically, of much importance, except that the gliders are believed to have been progressively larger, and therefore if we accept Wilbur Wright's own figure of the surface of the second glider, the third must have had a greater area than that given by Mr Griffith Brewer. Unfortunately, no evidence of the Wright Brothers themselves on this point is available. [*] Fourth Wilbur Wright Memorial Lecture, Aeronautical Journal, Vol. XX, No. 79, page 75. [**] Ibid. page 73. [***] Ibid. pp. 91 and 102. The first glide of the 1902, season was made on September 17th of that year, and the new machine at once showed itself an improvement on its predecessors, though subsequent trials showed that the difficulty of lateral balance had not been entirely overcome. It was decided, therefore, to turn the vertical fin at the rear into a rudder by making it movable. At the same time it was realised that there was a definite relation between lateral balance and directional control, and the rudder controls and wing-warping wires were accordingly connected This ended the pioneer gliding experiments of Wilbur and Orville Wright--though further glides were made in subsequent years--as the following year, 1903, saw the first power-driven machine leave the ground. To recapitulate--in the course of these original experiments the Wrights confirmed Lilienthal's theory of the reversal of the centre of pressure on cambered surfaces at small angles of incidence: they confirmed the importance of high aspect ratio in respect to lift: they had evolved new and more accurate tables of lift and pressure on cambered surfaces: they were the first to use a movable horizontal elevator for controlling height: they were the first to adjust the wings to different angles of incidence to maintain lateral balance: and they were the first to use the movable rudder and adjustable wings in combination. They now considered that they had gone far enough to justify them in building a power-driven 'flier,' as they called their first aeroplane. They could find no suitable engine and so proceeded to build for themselves an internal combustion engine, which was designed to give 8 horse-power, but when completed actually developed about 12-15 horse-power and weighed 240 lbs. The complete machine weighed about 750 lbs. Further details of the first Wright aeroplane are difficult to obtain, and even those here given should be received with some caution. The first flight was made on December 17th 1903, and lasted 12 seconds. Others followed immediately, and the fourth lasted 59 seconds, a distance of 852 feet being covered against a 20-mile wind. The following year they transferred operations to a field outside Dayton, Ohio (their home), and there they flew a somewhat larger and heavier machine with which on September 20th 1904, they completed the first circle in the air. In this machine for the first time the pilot had a seat; all the previous experiments having been carried out with the operator lying prone on the lower wing. This was followed next year by another still larger machine, and on it they carried out many flights. During the course of these flights they satisfied themselves as to the cause of a phenomenon which had puzzled them during the previous year and caused them to fear that they had not solved the problem of lateral control. They found that on occasions--always when on a turn--the machine began to slide down towards the ground and that no amount of warping could stop it. Finally it was found that if the nose of the machine was tilted down a recovery could be effected; from which they concluded that what actually happened was that the machine, 'owing to the increased load caused by centrifugal force,' had insufficient power to maintain itself in the air and therefore lost speed until a point was reached at which the controls became inoperative. In other words, this was the first experience of 'stalling on a turn,' which is a danger against which all embryo pilots have to guard in the early stages of their training. The 1905 machine was, like its predecessors, a biplane with a biplane elevator in front and a double vertical rudder in rear. The span was 40 feet, the chord of the wings being 6 feet and the gap between them about the same. The total area was about 600 square feet which supported a total weight of 925 lbs.; while the motor was 12 to 15 horse-power driving two propellers on each side behind the main planes through chains and giving the machine a speed of about 30 m.p.h. one of these chains was crossed so that the propellers revolved in opposite directions to avoid the torque which it was feared would be set up if they both revolved the same way. The machine was not fitted with a wheeled undercarriage but was carried on two skids, which also acted as outriggers to carry the elevator. Consequently, a mechanical method of launching had to be evolved and the machine received initial velocity from a rail, along which it was drawn by the impetus provided by the falling of a weight from a wooden tower or 'pylon.' As a result of this the Wright aeroplane in its original form had to be taken back to its starting rail after each flight, and could not restart from the point of alighting. Perhaps, in comparison with French machines of more or less contemporary date (evolved on independent lines in ignorance of the Americans' work), the chief feature of the Wright biplane of 1905 was that it relied entirely upon the skill of the operator for its stability; whereas in France some attempt was being made, although perhaps not very successfully, to make the machine automatically stable laterally. The performance of the Wrights in carrying a loading of some 60 lbs. per horse-power is one which should not be overlooked. The wing loading was about 1 1/2 lbs. per square foot. About the same time that the Wrights were carrying out their power-driven experiments, a band of pioneers was quite independently beginning to approach success in France. In practically every case, however, they started from a somewhat different standpoint and took as their basic idea the cellular (or box) kite. This form of kite, consisting of two superposed surfaces connected at each end by a vertical panel or curtain of fabric, had proved extremely successful for man-carrying purposes, and, therefore, it was little wonder that several minds conceived the idea of attempting to fly by fitting a series of box-kites with an engine. The first to achieve success was M. Santos-Dumont, the famous Brazilian pioneer-designer of airships, who, on November 12th, 1906, made several flights, the last of which covered a little over 700 feet. Santos-Dumont's machine consisted essentially of two box-kites, forming the main wings, one on each side of the body, in which the pilot stood, and at the front extremity of which was another movable box-kite to act as elevator and rudder. The curtains at the ends were intended to give lateral stability, which was further ensured by setting the wings slightly inclined upwards from the centre, so that when seen from the front they formed a wide V. This feature is still to be found in many aeroplanes to-day and has come to be known as the 'dihedral.' The motor was at first of 24 horse-power, for which later a 50 horse-power Antoinette engine was substituted; whilst a three-wheeled undercarriage was provided, so that the machine could start without external mechanical aid. The machine was constructed of bamboo and steel, the weight being as low as 352 lbs. The span was 40 feet, the length being 33 feet, with a total surface of main planes of 860 square feet. It will thus be seen--for comparison with the Wright machine--that the weight per horse-power (with the 50 horse-power engine) was only 7 lbs., while the wing loading was equally low at 1/2 lb. per square foot. The main features of the Santos-Dumont machine were the box-kite form of construction, with a dihedral angle on the main planes, and the forward elevator which could be moved in any direction and therefore acted in the same way as the rudder at the rear of the Wright biplane. It had a single propeller revolving in the centre behind the wings and was fitted with an undercarriage incorporated in the machine. The other chief French experimenters at this period were the Voisin Freres, whose first two machines--identical in form--were sold to Delagrange and H. Farman, which has sometimes caused confusion, the two purchasers being credited with the design they bought. The Voisins, like the Wrights, based their designs largely on the experimental work of Lilienthal, Langley, Chanute, and others, though they also carried out tests on the lifting properties of aerofoils in a wind tunnel of their own. Their first machines, like those of Santos-Dumont, showed the effects of experimenting with box-kites, some of which they had built for M. Ernest Archdeacon in 1904. In their case the machine, which was again a biplane, had, like both the others previously mentioned, an elevator in front--though in this case of monoplane form--and, as in the Wright, a rudder was fitted in rear of the main planes. The Voisins, however, fitted a fixed biplane horizontal 'tail'--in an effort to obtain a measure of automatic longitudinal stability--between the two surfaces of which the single rudder worked. For lateral stability they depended entirely on end curtains between the upper and lower surfaces of both the main planes and biplane tail surfaces. They, like Santos-Dumont, fitted a wheeled undercarriage, so that the machine was self-contained. The Voisin machine, then, was intended to be automatically stable in both senses; whereas the Wrights deliberately produced a machine which was entirely dependent upon the pilot's skill for its stability. The dimensions of the Voisin may be given for comparative purposes, and were as follows: Span 33 feet with a chord (width from back to front) of main planes of 6 1/2 feet, giving a total area of 430 square feet. The 50 horse-power Antoinette engine, which was enclosed in the body (or 'nacelle ') in the front of which the pilot sat, drove a propeller behind, revolving between the outriggers carrying the tail. The total weight, including Farman as pilot, is given as 1,540 lbs., so that the machine was much heavier than either of the others; the weight per horse-power being midway between the Santos-Dumont and the Wright at 31 lbs. per square foot, while the wing loading was considerably greater than either at 3 1/2 lbs. per square foot. The Voisin machine was experimented with by Farman and Delagrange from about June 1907 onwards, and was in the subsequent years developed by Farman; and right up to the commencement of the War upheld the principles of the box-kite method of construction for training purposes. The chief modification of the original design was the addition of flaps (or ailerons) at the rear extremities of the main planes to give lateral control, in a manner analogous to the wing-warping method invented by the Wrights, as a result of which the end curtains between the planes were abolished. An additional elevator was fitted at the rear of the fixed biplane tail, which eventually led to the discarding of the front elevator altogether. During the same period the Wright machine came into line with the others by the fitting of a wheeled undercarriage integral with the machine. A fixed horizontal tail was also added to the rear rudder, to which a movable elevator was later attached; and, finally, the front elevator was done away with. It will thus be seen that having started from the very different standpoints of automatic stability and complete control by the pilot, the Voisin (as developed in the Farman) and Wright machines, through gradual evolution finally resulted in aeroplanes of similar characteristics embodying a modicum of both features. Before proceeding to the next stage of progress mention should be made of the experimental work of Captain Ferber in France. This officer carried out a large number of experiments with gliders contemporarily with the Wrights, adopting--like them--the Chanute biplane principle. He adopted the front elevator from the Wrights, but immediately went a step farther by also fitting a fixed tail in rear, which did not become a feature of the Wright machine until some seven or eight years later. He built and appeared to have flown a machine fitted with a motor in 1905, and was commissioned to go to America by the French War Office on a secret mission to the Wrights. Unfortunately, no complete account of his experiments appears to exist, though it can be said that his work was at least as important as that of any of the other pioneers mentioned. II. MULTIPLICITY OF IDEAS In a review of progress such as this, it is obviously impossible, when a certain stage of development has been reached, owing to the very multiplicity of experimenters, to continue dealing in anything approaching detail with all the different types of machines; and it is proposed, therefore, from this point to deal only with tendencies, and to mention individuals merely as examples of a class of thought rather than as personalities, as it is often difficult fairly to allocate the responsibility for any particular innovation. During 1907 and 1908 a new type of machine, in the monoplane, began to appear from the workshops of Louis Bleriot, Robert Esnault-Pelterie, and others, which was destined to give rise to long and bitter controversies on the relative advantages of the two types, into which it is not proposed to enter here; though the rumblings of the conflict are still to be heard by discerning ears. Bleriot's early monoplanes had certain new features, such as the location of the pilot, and in some cases the engine, below the wing; but in general his monoplanes, particularly the famous No. XI on which the first Channel crossing was made on July 25th, 1909, embodied the main principles of the Wright and Voisin types, except that the propeller was in front of instead of behind the supporting surfaces, and was, therefore, what is called a 'tractor' in place of the then more conventional 'pusher.' Bleriot aimed at lateral balance by having the tip of each wing pivoted, though he soon fell into line with the Wrights and adopted the warping system. The main features of the design of Esnault-Pelterie's monoplane was the inverted dihedral (or kathedral as this was called in Mr S. F. Cody's British Army Biplane of 1907) on the wings, whereby the tips were considerably lower than the roots at the body. This was designed to give automatic lateral stability, but, here again, conventional practice was soon adopted and the R.E.P. monoplanes, which became well-known in this country through their adoption in the early days by Messrs Vickers, were of the ordinary monoplane design, consisting of a tractor propeller with wire-stayed wings, the pilot being in an enclosed fuselage containing the engine in front and carrying at its rear extremity fixed horizontal and vertical surfaces combined with movable elevators and rudder. Constructionally, the R.E.P. monoplane was of extreme interest as the body was constructed of steel. The Antoinette monoplane, so ably flown by Latham, was another very famous machine of the 1909-1910 period, though its performance were frequently marred by engine failure; which was indeed the bugbear of all these early experimenters, and it is difficult to say, after this lapse of time, how far in many cases the failures which occurred, both in performances and even in the actual ability to rise from the ground, were due to defects in design or merely faults in the primitive engines available. The Antoinette aroused admiration chiefly through its graceful, birdlike lines, which have probably never been equalled; but its chief interest for our present purpose lies in the novel method of wing-staying which was employed. Contemporary monoplanes practically all had their wings stayed by wires to a post in the centre above the fuselage, and, usually, to the undercarriage below. In the Antoinette, however, a king post was introduced half-way along the wing, from which wires were carried to the ends of the wings and the body. This was intended to give increased strength and permitted of a greater wing-spread and consequently improved aspect ratio. The same system of construction was adopted in the British Martinsyde monoplanes of two or three years later. This period also saw the production of the first triplane, which was built by A. V. Roe in England and was fitted with a J.A.P. engine of only 9 horse-power--an amazing performance which remains to this day unequalled. Mr Roe's triplane was chiefly interesting otherwise for the method of maintaining longitudinal control, which was achieved by pivoting the whole of the three main planes so that their angle of incidence could be altered. This was the direct converse of the universal practice of elevating by means of a subsidiary surface either in front or rear of the main planes. Recollection of the various flying meetings and exhibitions which one attended during the years from 1909 to 1911, or even 1912 are chiefly notable for the fact that the first thought on seeing any new type of machine was not as to what its 'performance'--in speed, lift, or what not--would be; but speculation as to whether it would leave the ground at all when eventually tried. This is perhaps the best indication of the outstanding characteristic of that interim period between the time of the first actual flights and the later period, commencing about 1912, when ideas had become settled and it was at last becoming possible to forecast on the drawing-board the performance of the completed machine in the air. Without going into details, for which there is no space here, it is difficult to convey the correct impression of the chaotic state which existed as to even the elementary principles of aeroplane design. All the exhibitions contained large numbers--one had almost written a majority--of machines which embodied the most unusual features and which never could, and in practice never did, leave the ground. At the same time, there were few who were sufficiently hardy to say certainly that this or that innovation was wrong; and consequently dozens of inventors in every country were conducting isolated experiments on both good and bad lines. All kinds of devices, mechanical and otherwise, were claimed as the solution of the problem of stability, and there was even controversy as to whether any measure of stability was not undesirable; one school maintaining that the only safety lay in the pilot having the sole say in the attitude of the machine at any given moment, and fearing danger from the machine having any mind of its own, so to speak. There was, as in most controversies, some right on both sides, and when we come to consider the more settled period from 1912 to the outbreak of the War in 1914 we shall find how a compromise was gradually effected. At the same time, however, though it was at the time difficult to pick out, there was very real progress being made, and, though a number of 'freak' machines fell out by the wayside, the pioneer designers of those days learnt by a process of trial and error the right principles to follow and gradually succeeded in getting their ideas crystallised. In connection with stability mention must be made of a machine which was evolved in the utmost secrecy by Mr J. W. Dunne in a remote part of Scotland under subsidy from the War office. This type, which was constructed in both monoplane and biplane form, showed that it was in fact possible in 1910 and 1911 to design an aeroplane which could definitely be left to fly itself in the air. One of the Dunne machines was, for example flown from Farnborough to Salisbury Plain without any control other than the rudder being touched; and on another occasion it flew a complete circle with all controls locked automatically assuming the correct bank for the radius of turn. The peculiar form of wing used, the camber of which varied from the root to the tip, gave rise however, to a certain loss in efficiency, and there was also a difficulty in the pilot assuming adequate control when desired. Other machines designed to be stable--such as the German Etrich and the British Weiss gliders and Handley-Page monoplanes--were based on the analogy of a wing attached to a certain seed found in Nature (the 'Zanonia' leaf), on the righting effect of back-sloped wings combined with upturned (or 'negative') tips. Generally speaking, however, the machines of the 1909-1912 period relied for what automatic stability they had on the principle of the dihedral angle, or flat V, both longitudinally and laterally. Longitudinally this was obtained by setting the tail at a slightly smaller angle than the main planes. The question of reducing the resistance by adopting 'stream-line' forms, along which the air could flow uninterruptedly without the formation of eddies, was not at first properly realised, though credit should be given to Edouard Nieuport, who in 1909 produced a monoplane with a very large body which almost completely enclosed the pilot and made the machine very fast, for those days, with low horse-power. On one of these machines C. T. Weyman won the Gordon-Bennett Cup for America in 1911 and another put up a fine performance in the same race with only a 30 horse-power engine. The subject, was however, early taken up by the British Advisory Committee for Aeronautics, which was established by the Government in 1909, and designers began to realise the importance of streamline struts and fuselages towards the end of this transition period. These efforts were at first not always successful and showed at times a lack of understanding of the problems involved, but there was a very marked improvement during the year 1912. At the Paris Aero Salon held early in that year there was a notable variety of ideas on the subject; whereas by the time of the one held in October designs had considerably settled down, more than one exhibitor showing what were called 'monocoque' fuselages completely circular in shape and having very low resistance, while the same show saw the introduction of rotating cowls over the propeller bosses, or 'spinners,' as they came to be called during the War. A particularly fine example of stream-lining was to be found in the Deperdussin monoplane on which Vedrines won back the Gordon-Bennett Aviation Cup from America at a speed of 105.5 m.p.h.--a considerable improvement on the 78 m.p.h. of the preceding year, which was by no means accounted for by the mere increase in engine power from 100 horse-power to 140 horse-power. This machine was the first in which the refinement of 'stream-lining' the pilot's head, which became a feature of subsequent racing machines, was introduced. This consisted of a circular padded excresence above the cockpit immediately behind the pilot's head, which gradually tapered off into the top surface of the fuselage. The object was to give the air an uninterrupted flow instead of allowing it to be broken up into eddies behind the head of the pilot, and it also provided a support against the enormous wind-pressure encountered. This true stream-line form of fuselage owed its introduction to the Paulhan-Tatin 'Torpille' monoplane of the Paris Salon of early 1917. Altogether the end of the year 1912 began to see the disappearance of 'freak' machines with all sorts of original ideas for the increase of stability and performance. Designs had by then gradually become to a considerable extent standardised, and it had become unusual to find a machine built which would fail to fly. The Gnome engine held the field owing to its advantages, as the first of the rotary type, in lightness and ease of fitting into the nose of a fuselage. The majority of machines were tractors (propeller in front) although a preference, which died down subsequently, was still shown for the monoplane over the biplane. This year also saw a great increase in the number of seaplanes, although the 'flying boat' type had only appeared at intervals and the vast majority were of the ordinary aeroplane type fitted with floats in place of the land undercarriage; which type was at that time commonly called 'hydro-aeroplane.' The usual horse power was 50--that of the smallest Gnome engine--although engines of 100 to 140 horse-power were also fitted occasionally. The average weight per horse-power varied from 18 to 25 lbs., while the wing-loading was usually in the neighbourhood of 5 to 6 lbs. per square foot. The average speed ranged from 65-75 miles per hour. III. PROGRESS ON STANDARDISED LINES In the last section an attempt has been made to show how, during what was from the design standpoint perhaps the most critical period, order gradually became evident out of chaos, ill-considered ideas dropped out through failure to make good, and, though there was still plenty of room for improvement in details, the bulk of the aeroplanes showed a general similarity in form and conception. There was still a great deal to be learnt in finding the best form of wing section, and performances were still low; but it had become definitely possible to say that flying had emerged from the chrysalis stage and had become a science. The period which now began was one of scientific development and improvement--in performance, manoeuvrability, and general airworthiness and stability. The British Military Aeroplane Competition held in the summer of 1912 had done much to show the requirements in design by giving possibly the first opportunity for a definite comparison of the performance of different machines as measured by impartial observers on standard lines--albeit the methods of measuring were crude. These showed that a high speed--for those days--of 75 miles an hour or so was attended by disadvantages in the form of an equally fast low speed, of 50 miles per hour or more, and generally may be said to have given designers an idea what to aim for and in what direction improvements were required. In fact, the most noticeable point perhaps of the machines of this time was the marked manner in which a machine that was good in one respect would be found to be wanting in others. It had not yet been possible to combine several desirable attributes in one machine. The nearest approach to this was perhaps to be found in the much discussed Government B.E.2 machine, which was produced from the Royal Aircraft Factory at Farnborough, in the summer of 1912. Though considerably criticized from many points of view it was perhaps the nearest approach to a machine of all-round efficiency that had up to that date appeared. The climbing rate, which subsequently proved so important for military purposes, was still low, seldom, if ever, exceeding 400 feet per minute; while gliding angles (ratio of descent to forward travel over the ground with engine stopped) little exceeded 1 in 8. The year 1912 and 1913 saw the subsequently all-conquering tractor biplane begin to come into its own. This type, which probably originated in England, and at any rate attained to its greatest excellence prior to the War from the drawing offices of the Avro Bristol and Sopwith firms, dealt a blow at the monoplane from which the latter never recovered. The two-seater tractor biplane produced by Sopwith and piloted by H. G. Hawker, showed that it was possible to produce a biplane with at least equal speed to the best monoplanes, whilst having the advantage of greater strength and lower landing speeds. The Sopwith machine had a top speed of over 80 miles an hour while landing as slowly as little more than 30 miles an hour; and also proved that it was possible to carry 3 passengers with fuel for 4 hours' flight with a motive power of only 80 horse-power. This increase in efficiency was due to careful attention to detail in every part, improved wing sections, clean fuselage-lines, and simplified undercarriages. At the same time, in the early part of 1913 a tendency manifested itself towards the four-wheeled undercarriage, a pair of smaller wheels being added in front of the main wheels to prevent overturning while running on the ground; and several designs of oleo-pneumatic and steel-spring undercarriages were produced in place of the rubber shock-absorber type which had up till then been almost universal. These two statements as to undercarriage designs may appear to be contradictory, but in reality they do not conflict as they both showed a greater attention to the importance of good springing, combined with a desire to avoid complication and a mass of struts and wires which increased head resistance. The Olympia Aero Show of March, 1913, also produced a machine which, although the type was not destined to prove the best for the purpose for which it was designed, was of interest as being the first to be designed specially for war purposes. This was the Vickers 'Gun-bus,' a 'pusher' machine, with the propeller revolving behind the main planes between the outriggers carrying the tail, with a seat right in front for a gunner who was provided with a machine gun on a swivelling mount which had a free field of fire in every direction forward. The device which proved the death-blow for this type of aircraft during the war will be dealt with in the appropriate place later, but the machine should not go unrecorded. As a result of a number of accidents to monoplanes the Government appointed a Committee at the end of 1912 to inquire into the causes of these. The report which was presented in March, 1913, exonerated the monoplane by coming to the conclusion that the accidents were not caused by conditions peculiar to monoplanes, but pointed out certain desiderata in aeroplane design generally which are worth recording. They recommended that the wings of aeroplanes should be so internally braced as to have sufficient strength in themselves not to collapse if the external bracing wires should give way. The practice, more common in monoplanes than biplanes, of carrying important bracing wires from the wings to the undercarriage was condemned owing to the liability of damage from frequent landings. They also pointed out the desirability of duplicating all main wires and their attachments, and of using stranded cable for control wires. Owing to the suspicion that one accident at least had been caused through the tearing of the fabric away from the wing, it was recommended that fabric should be more securely fastened to the ribs of the wings, and that devices for preventing the spreading of tears should be considered. In the last connection it is interesting to note that the French Deperdussin firm produced a fabric wing-covering with extra strong threads run at right-angles through the fabric at intervals in order to limit the tearing to a defined area. In spite, however, of the whitewashing of the monoplane by the Government Committee just mentioned, considerable stir was occasioned later in the year by the decision of the War office not to order any more monoplanes; and from this time forward until the War period the British Army was provided exclusively with biplanes. Even prior to this the popularity of the monoplane had begun to wane. At the Olympia Aero Show in March, 1913, biplanes for the first time outnumbered the 'single-deckers'(as the Germans call monoplanes); which had the effect of reducing the wing-loading. In the case of the biplanes exhibited this averaged about 4 1/2 lbs. per square foot, while in the case of the monoplanes in the same exhibition the lowest was 5 1/2 lbs., and the highest over 8 1/2 lbs. per square foot of area. It may here be mentioned that it was not until the War period that the importance of loading per horse-power was recognised as the true criterion of aeroplane efficiency, far greater interest being displayed in the amount of weight borne per unit area of wing. An idea of the state of development arrived at about this time may be gained from the fact that the Commandant of the Military Wing of the Royal Flying Corps in a lecture before the Royal Aeronautical Society read in February, 1913, asked for single-seater scout aeroplanes with a speed of 90 miles an hour and a landing speed of 45 miles an hour--a performance which even two years later would have been considered modest in the extreme. It serves to show that, although higher performances were put up by individual machines on occasion, the general development had not yet reached the stage when such performances could be obtained in machines suitable for military purposes. So far as seaplanes were concerned, up to the beginning of 1913 little attempt had been made to study the novel problems involved, and the bulk of the machines at the Monaco Meeting in April, 1913, for instance, consisted of land machines fitted with floats, in many cases of a most primitive nature, without other alterations. Most of those which succeeded in leaving the water did so through sheer pull of engine power; while practically all were incapable of getting off except in a fair sea, which enabled the pilot to jump the machine into the air across the trough between two waves. Stability problems had not yet been considered, and in only one or two cases was fin area added at the rear high up, to counterbalance the effect of the floats low down in front. Both twin and single-float machines were used, while the flying boat was only just beginning to come into being from the workshops of Sopwith in Great Britain, Borel-Denhaut in France, and Curtiss in America. In view of the approaching importance of amphibious seaplanes, mention should be made of the flying boat (or 'bat boat' as it was called, following Rudyard Kipling) which was built by Sopwith in 1913 with a wheeled landing-carriage which could be wound up above the bottom surface of the boat so as to be out of the way when alighting on water. During 1913 the (at one time almost universal) practice originated by the Wright Brothers, of warping the wings for lateral stability, began to die out and the bulk of aeroplanes began to be fitted with flaps (or 'ailerons') instead. This was a distinct change for the better, as continually warping the wings by bending down the extremities of the rear spars was bound in time to produce 'fatigue' in that member and lead to breakage; and the practice became completely obsolete during the next two or three years. The Gordon-Bennett race of September, 1913, was again won by a Deperdussin machine, somewhat similar to that of the previous year, but with exceedingly small wings, only 107 square feet in area. The shape of these wings was instructive as showing how what, from the general utility point of view, may be disadvantageous can, for a special purpose, be turned to account. With a span of 21 feet, the chord was 5 feet, giving the inefficient 'aspect ratio' of slightly over 4 to 1 only. The object of this was to reduce the lift, and therefore the resistance, to as low a point as possible. The total weight was 1,500 lbs., giving a wing-loading of 14 lbs. per square foot--a hitherto undreamt-of figure. The result was that the machine took an enormously long run before starting; and after touching the ground on landing ran for nearly a mile before stopping; but she beat all records by attaining a speed of 126 miles per hour. Where this performance is mainly interesting is in contrast to the machines of 1920, which with an even higher speed capacity would yet be able to land at not more than 40 or 50 miles per hour, and would be thoroughly efficient flying machines. The Rheims Aviation Meeting, at which the Gordon-Bennett race was flown, also saw the first appearance of the Morane 'Parasol' monoplane. The Morane monoplane had been for some time an interesting machine as being the only type which had no fixed surface in rear to give automatic stability, the movable elevator being balanced through being hinged about one-third of the way back from the front edge. This made the machine difficult to fly except in the hands of experts, but it was very quick and handy on the controls and therefore useful for racing purposes. In the 'Parasol' the modification was introduced of raising the wing above the body, the pilot looking out beneath it, in order to give as good a view as possible. Before passing to the year 1914 mention should be made of the feat performed by Nesteroff, a Russian, and Pegoud, a French pilot, who were the first to demonstrate the possibilities of flying upside-down and looping the loop. Though perhaps not coming strictly within the purview of a chapter on design (though certain alterations were made to the top wing-bracing of the machine for this purpose) this performance was of extreme importance to the development of aviation by showing the possibility of recovering, given reasonable height, from any position in the air; which led designers to consider the extra stresses to which an aeroplane might be subjected and to take steps to provide for them by increasing strength where necessary. When the year 1914 opened a speed of 126 miles per hour had been attained and a height of 19,600 feet had been reached. The Sopwith and Avro (the forerunner of the famous training machine of the War period) were probably the two leading tractor biplanes of the world, both two-seaters with a speed variation from 40 miles per hour up to some 90 miles per hour with 80 horse-power engines. The French were still pinning their faith mainly to monoplanes, while the Germans were beginning to come into prominence with both monoplanes and biplanes of the 'Taube' type. These had wings swept backward and also upturned at the wing-tips which, though it gave a certain measure of automatic stability, rendered the machine somewhat clumsy in the air, and their performances were not on the whole as high as those of either France or Great Britain. Early in 1914 it became known that the experimental work of Edward Busk--who was so lamentably killed during an experimental flight later in the year--following upon the researches of Bairstow and others had resulted in the production at the Royal Aircraft Factory at Farnborough of a truly automatically stable aeroplane. This was the 'R.E.' (Reconnaissance Experimental), a development of the B.E. which has already been referred to. The remarkable feature of this design was that there was no particular device to which one could point out as the cause of the stability. The stable result was attained simply by detailed design of each part of the aeroplane, with due regard to its relation to, and effect on, other parts in the air. Weights and areas were so nicely arranged that under practically any conditions the machine tended to right itself. It did not, therefore, claim to be a machine which it was impossible to upset, but one which if left to itself would tend to right itself from whatever direction a gust might come. When the principles were extended to the 'B.E. 2c' type (largely used at the outbreak of the War) the latter machine, if the engine were switched of f at a height of not less than 1,000 feet above the ground, would after a few moments assume its correct gliding angle and glide down to the ground. The Paris Aero Salon of December, 1913, had been remarkable chiefly for the large number of machines of which the chassis and bodywork had been constructed of steel-tubing; for the excess of monoplanes over biplanes; and (in the latter) predominance of 'pusher' machines (with propeller in rear of the main planes) compared with the growing British preference for 'tractors' (with air screw in front). Incidentally, the Maurice Farman, the last relic of the old type box-kite with elevator in front appeared shorn of this prefix, and became known as the 'short-horn' in contradistinction to its front-elevatored predecessor which, owing to its general reliability and easy flying capabilities, had long been affectionately called the 'mechanical cow.' The 1913 Salon also saw some lingering attempts at attaining automatic stability by pendulum and other freak devices. Apart from the appearance of 'R.E.1,' perhaps the most notable development towards the end of 1913 was the appearance of the Sopwith 'Tabloid 'tractor biplane. This single-seater machine, evolved from the two-seater previously referred to, fitted with a Gnome engine of 80 horse-power, had the, for those days, remarkable speed of 92 miles an hour; while a still more notable feature was that it could remain in level flight at not more than 37 miles per hour. This machine is of particular importance because it was the prototype and forerunner of the successive designs of single-seater scout fighting machines which were used so extensively from 1914 to 1918. It was also probably the first machine to be capable of reaching a height of 1,000 feet within one minute. It was closely followed by the 'Bristol Bullet,' which was exhibited at the Olympia Aero Show of March, 1914. This last pre-war show was mainly remarkable for the good workmanship displayed--rather than for any distinct advance in design. In fact, there was a notable diversity in the types displayed, but in detailed design considerable improvements were to be seen, such as the general adoption of stranded steel cable in place of piano wire for the mail bracing. IV. THE WAR PERIOD Up to this point an attempt has been made to give some idea of the progress that was made during the eleven years that had elapsed since the days of the Wrights' first flights. Much advance had been made and aeroplanes had settled down, superficially at any rate, into more or less standardised forms in three main types--tractor monoplanes, tractor biplanes, and pusher biplanes. Through the application of the results of experiments with models in wind tunnels to full-scale machines, considerable improvements had been made in the design of wing sections, which had greatly increased the efficiency of aeroplanes by raising the amount of 'lift' obtained from the wing compared with the 'drag' (or resistance to forward motion) which the same wing would cause. In the same way the shape of bodies, interplane struts, etc., had been improved to be of better stream-line shape, for the further reduction of resistance; while the problems of stability were beginning to be tolerably well understood. Records (for what they are worth) stood at 21,000 feet as far as height was concerned, 126 miles per hour for speed, and 24 hours duration. That there was considerable room for development is, however, evidenced by a statement made by the late B. C. Hucks (the famous pilot) in the course of an address delivered before the Royal Aeronautical Society in July, 1914. 'I consider,' he said, 'that the present day standard of flying is due far more to the improvement in piloting than to the improvement in machines.... I consider those (early 1914) machines are only slight improvements on the machines of three years ago, and yet they are put through evolutions which, at that time, were not even dreamed of. I can take a good example of the way improvement in piloting has outdistanced improvement in machines--in the case of myself, my 'looping' Bleriot. Most of you know that there is very little difference between that machine and the 50 horse-power Bleriot of three years ago.' This statement was, of course, to some extent an exaggeration and was by no means agreed with by designers, but there was at the same time a germ of truth in it. There is at any rate little doubt that the theory and practice of aeroplane design made far greater strides towards becoming an exact science during the four years of War than it had done during the six or seven years preceding it. It is impossible in the space at disposal to treat of this development even with the meagre amount of detail that has been possible while covering the 'settling down' period from 1911 to 1914, and it is proposed, therefore, to indicate the improvements by sketching briefly the more noticeable difference in various respects between the average machine of 1914 and a similar machine of 1918. In the first place, it was soon found that it was possible to obtain greater efficiency and, in particular, higher speeds, from tractor machines than from pusher machines with the air screw behind the main planes. This was for a variety of reasons connected with the efficiency of propellers and the possibility of reducing resistance to a greater extent in tractor machines by using a 'stream-line' fuselage (or body) to connect the main planes with the tail. Full advantage of this could not be taken, however, owing to the difficulty of fixing a machine-gun in a forward direction owing to the presence of the propeller. This was finally overcome by an ingenious device (known as an 'Interrupter gear') which allowed the gun to fire only when none of the propeller blades was passing in front of the muzzle. The monoplane gradually fell into desuetude, mainly owing to the difficulty of making that type adequately strong without it becoming prohibitively heavy, and also because of its high landing speed and general lack of manoeuvrability. The triplane was also little used except in one or two instances, and, practically speaking, every machine was of the biplane tractor type. A careful consideration of the salient features leading to maximum efficiency in aeroplanes--particularly in regard to speed and climb, which were the two most important military requirements--showed that a vital feature was the reduction in the amount of weight lifted per horse-power employed; which in 1914 averaged from 20 to 25 lbs. This was effected both by gradual increase in the power and size of the engines used and by great improvement in their detailed design (by increasing compression ratio and saving weight whenever possible); with the result that the motive power of single-seater aeroplanes rose from 80 and 100 horse-power in 1914 to an average of 200 to 300 horse-power, while the actual weight of the engine fell from 3 1/2-4 lbs. per horse-power to an average of 2 1/2 lbs. per horse-power. This meant that while a pre-war engine of 100 horse-power would weigh some 400 lbs., the 1918 engine developing three times the power would have less than double the weight. The result of this improvement was that a scout aeroplane at the time of the Armistice would have 1 horse-power for every 8 lbs. of weight lifted, compared with the 20 or 25 lbs. of its 1914 predecessors. This produced a considerable increase in the rate of climb, a good postwar machine being able to reach 10,000 feet in about 5 minutes and 20,000 feet in under half an hour. The loading per square foot was also considerably increased; this being rendered possible both by improvement in the design of wing sections and by more scientific construction giving increased strength. It will be remembered that in the machine of the very early period each square foot of surface had only to lift a weight of some 1 1/2 to 2 lbs., which by 1914 had been increased to about 4 lbs. By 1918 aeroplanes habitually had a loading of 8 lbs. or more per square foot of area; which resulted in great increase in speed. Although a speed of 126 miles per hour had been attained by a specially designed racing machine over a short distance in 1914, the average at that period little exceeded, if at all, 100 miles per hour; whereas in 1918 speeds of 130 miles per hour had become a commonplace, and shortly afterwards a speed of over 166 miles an hour was achieved. In another direction, also, that of size, great developments were made. Before the War a few machines fitted with more than one engine had been built (the first being a triple Gnome-engined biplane built by Messrs Short Bros. at Eastchurch in 1913), but none of large size had been successfully produced, the total weight probably in no case exceeding about 2 tons. In 1916, however, the twin engine Handley-Page biplane was produced, to be followed by others both in this country and abroad, which represented a very great increase in size and, consequently, load-carrying capacity. By the end of the War period several types were in existence weighing a total of 10 tons when fully loaded, of which some 4 tons or more represented 'useful load' available for crew, fuel, and bombs or passengers. This was attained through very careful attention to detailed design, which showed that the material could be employed more efficiently as size increased, and was also due to the fact that a large machine was not liable to be put through the same evolutions as a small machine, and therefore could safely be built with a lower factor of safety. Owing to the fact that a wing section which is adopted for carrying heavy loads usually has also a somewhat low lift to drag ratio, and is not therefore productive of high speed, these machines are not as fast as light scouts; but, nevertheless, they proved themselves capable of achieving speeds of 100 miles an hour or more in some cases; which was faster than the average small machine of 1914. In one respect the development during the War may perhaps have proved to be somewhat disappointing, as it might have been expected that great improvements would be effected in metal construction, leading almost to the abolition of wooden structures. Although, however, a good deal of experimental work was done which resulted in overcoming at any rate the worst of the difficulties, metal-built machines were little used (except to a certain extent in Germany) chiefly on account of the need for rapid production and the danger of delay resulting from switching over from known and tried methods to experimental types of construction. The Germans constructed some large machines, such as the giant Siemens-Schukhert machine, entirely of metal except for the wing covering, while the Fokker and Junker firms about the time of the Armistice in 1918 both produced monoplanes with very deep all-metal wings (including the covering) which were entirely unstayed externally, depending for their strength on internal bracing. In Great Britain cable bracing gave place to a great extent to 'stream-line wires,' which are steel rods rolled to a more or less oval section, while tie-rods were also extensively used for the internal bracing of the wings. Great developments in the economical use of material were also made in the direction of using built-up main spars for the wings and interplane struts; spars composed of a series of layers (or 'laminations') of different pieces of wood also being used. Apart from the metallic construction of aeroplanes an enormous amount of work was done in the testing of different steels and light alloys for use in engines, and by the end of the War period a number of aircraft engines were in use of which the pistons and other parts were of such alloys; the chief difficulty having been not so much in the design as in the successful heat-treatment and casting of the metal. An important development in connection with the inspection and testing of aircraft parts, particularly in the case of metal, was the experimental application of X-ray photography, which showed up latent defects, both in the material and in manufacture, which would otherwise have passed unnoticed. This method was also used to test the penetration of glue into the wood on each side of joints, so giving a measure of the strength; and for the effect of 'doping' the wings, dope being a film (of cellulose acetate dissolved in acetone with other chemicals) applied to the covering of wings and bodies to render the linen taut and weatherproof, besides giving it a smooth surface for the lessening of 'skin friction' when passing rapidly through the air. An important result of this experimental work was that it in many cases enabled designers to produce aeroplane parts from less costly material than had previously been considered necessary, without impairing the strength. It may be mentioned that it was found undesirable to use welded joints on aircraft in any part where the material is subjectto a tensile or bending load, owing to the danger resulting from bad workmanship causing the material to become brittle--an effect which cannot be discovered except by cutting through the weld, which, of course, involves a test to destruction. Written, as it has been, in August, 1920, it is impossible in this chapter to give any conception of how the developments of War will be applied to commercial aeroplanes, as few truly commercial machines have yet been designed, and even those still show distinct traces of the survival of war mentality. When, however, the inevitable recasting of ideas arrives, it will become evident, whatever the apparent modification in the relative importance of different aspects of design, that enormous advances were made under the impetus of War which have left an indelible mark on progress. We have, during the seventeen years since aeroplanes first took the air, seen them grow from tentative experimental structures of unknown and unknowable performance to highly scientific products, of which not only the performances (in speed, load-carrying capacity, and climb) are known, but of which the precise strength and degree of stability can be forecast with some accuracy on the drawing board. For the rest, with the future lies--apart from some revolutionary change in fundamental design--the steady development of a now well-tried and well-found engineering structure. PART III. AEROSTATICS I. BEGINNINGS Francesco Lana, with his 'aerial ship,' stands as one of the first great exponents of aerostatics; up to the time of the Montgolfier and Charles balloon experiments, aerostatic and aerodynamic research are so inextricably intermingled that it has been thought well to treat of them as one, and thus the work of Lana, Veranzio and his parachute, Guzman's frauds, and the like, have already been sketched. In connection with Guzman, Hildebrandt states in his Airships Past and Present, a fairly exhaustive treatise on the subject up to 1906, the year of its publication, that there were two inventors--or charlatans--Lorenzo de Guzman and a monk Bartolemeo Laurenzo, the former of whom constructed an unsuccessful airship out of a wooden basket covered with paper, while the latter made certain experiments with a machine of which no description remains. A third de Guzman, some twenty-five years later, announced that he had constructed a flying machine, with which he proposed to fly from a tower to prove his success to the public. The lack of record of any fatal accident overtaking him about that time seems to show that the experiment was not carried out. Galien, a French monk, published a book L'art de naviguer dans l'air in 1757, in which it was conjectured that the air at high levels was lighter than that immediately over the surface of the earth. Galien proposed to bring down the upper layers of air and with them fill a vessel, which by Archimidean principle would rise through the heavier atmosphere. If one went high enough, said Galien, the air would be two thousand times as light as water, and it would be possible to construct an airship, with this light air as lifting factor, which should be as large as the town of Avignon, and carry four million passengers with their baggage. How this high air was to be obtained is matter for conjecture--Galien seems to have thought in a vicious circle, in which the vessel that must rise to obtain the light air must first be filled with it in order to rise. Cavendish's discovery of hydrogen in 1776 set men thinking, and soon a certain Doctor Black was suggesting that vessels might be filled with hydrogen, in order that they might rise in the air. Black, however, did not get beyond suggestion; it was Leo Cavallo who first made experiments with hydrogen, beginning with filling soap bubbles, and passing on to bladders and special paper bags. In these latter the gas escaped, and Cavallo was about to try goldbeaters' skin at the time that the Montgolfiers came into the field with their hot air balloon. Joseph and Stephen Montgolfier, sons of a wealthy French paper manufacturer, carried out many experiments in physics, and Joseph interested himself in the study of aeronautics some time before the first balloon was constructed by the brothers--he is said to have made a parachute descent from the roof of his house as early as 1771, but of this there is no proof. Galien's idea, together with study of the movement of clouds, gave Joseph some hope of achieving aerostation through Galien's schemes, and the first experiments were made by passing steam into a receiver, which, of course, tended to rise--but the rapid condensation of the steam prevented the receiver from more than threatening ascent. The experiments were continued with smoke, which produced only a slightly better effect, and, moreover, the paper bag into which the smoke was induced permitted of escape through its pores; finding this method a failure the brothers desisted until Priestley's work became known to them, and they conceived the use of hydrogen as a lifting factor. Trying this with paper bags, they found that the hydrogen escaped through the pores of the paper. Their first balloon, made of paper, reverted to the hot-air principle; they lighted a fire of wool and wet straw under the balloon--and as a matter of course the balloon took fire after very little experiment; thereupon they constructed a second, having a capacity of 700 cubic feet, and this rose to a height of over 1,000 feet. Such a success gave them confidence, and they gave their first public exhibition on June 5th, 1783, with a balloon constructed of paper and of a circumference of 112 feet. A fire was lighted under this balloon, which, after rising to a height of 1,000 feet, descended through the cooling of the air inside a matter of ten minutes. At this the Academie des Sciences invited the brothers to conduct experiments in Paris. The Montgolfiers were undoubtedly first to send up balloons, but other experimenters were not far behind them, and before they could get to Paris in response to their invitation, Charles, a prominent physicist of those days, had constructed a balloon of silk, which he proofed against escape of gas with rubber--the Roberts had just succeeded in dissolving this substance to permit of making a suitable coating for the silk. With a quarter of a ton of sulphuric acid, and half a ton of iron filings and turnings, sufficient hydrogen was generated in four days to fill Charles's balloon, which went up on August 28th, 1783. Although the day was wet, Paris turned out to the number of over 300,000 in the Champs de Mars, and cannon were fired to announce the ascent of the balloon. This, rising very rapidly, disappeared amid the rain clouds, but, probably bursting through no outlet being provided to compensate for the escape of gas, fell soon in the neighbourhood of Paris. Here peasants, ascribing evil supernatural influence to the fall of such a thing from nowhere, went at it with the implements of their craft--forks, hoes, and the like--and maltreated it severely, finally attaching it to a horse's tail and dragging it about until it was mere rag and scrap. Meanwhile, Joseph Montgolfier, having come to Paris, set about the construction of a balloon out of linen; this was in three diverse sections, the top being a cone 30 feet in depth, the middle a cylinder 42 feet in diameter by 26 feet in depth, and the bottom another cone 20 feet in depth from junction with the cylindrical portion to its point. The balloon was both lined and covered with paper, decorated in blue and gold. Before ever an ascent could be attempted this ambitious balloon was caught in a heavy rainstorm which reduced its paper covering to pulp and tore the linen at its seams, so that a supervening strong wind tore the whole thing to shreds. Montgolfier's next balloon was spherical, having a capacity of 52,000 cubic feet. It was made from waterproofed linen, and on September 19th, 1783, it made an ascent for the palace courtyard at Versailles, taking up as passengers a cock, a sheep, and a duck. A rent at the top of the balloon caused it to descend within eight minutes, and the duck and sheep were found none the worse for being the first living things to leave the earth in a balloon, but the cock, evidently suffering, was thought to have been affected by the rarefaction of the atmosphere at the tremendous height reached--for at that time the general opinion was that the atmosphere did not extend more than four or five miles above the earth's surface. It transpired later that the sheep had trampled on the cock, causing more solid injury than any that might be inflicted by rarefied air in an eight-minute ascent and descent of a balloon. For achieving this flight Joseph Montgolfier received from the King of France a pension of of L40, while Stephen was given the order of St Michael, and a patent of nobility was granted to their father. They were made members of the Legion d'Honneur, and a scientific deputation, of which Faujas de Saint-Fond, who had raised the funds with which Charles's hydrogen balloon was constructed, presented to Stephen Montgolfier a gold medal struck in honour of his aerial conquest. Since Joseph appears to have had quite as much share in the success as Stephen, the presentation of the medal to one brother only was in questionable taste, unless it was intended to balance Joseph's pension. Once aerostation had been proved possible, many people began the construction of small balloons--the wholehole thing was regarded as a matter of spectacles and a form of amusement by the great majority. A certain Baron de Beaumanoir made the first balloon of goldbeaters' skin, this being eighteen inches in diameter, and using hydrogen as a lifting factor. Few people saw any possibilities in aerostation, in spite of the adventures of the duck and sheep and cock; voyages to the moon were talked and written, and there was more of levity than seriousness over ballooning as a rule. The classic retort of Benjamin Franklin stands as an exception to the general rule: asked what was the use of ballooning--'What's the use of a baby?' he countered, and the spirit of that reply brought both the dirigible and the aeroplane to being, later. The next noteworthy balloon was one by Stephen Montgolfier, designed to take up passengers, and therefore of rather large dimensions, as these things went then. The capacity was 100,000 cubic feet, the depth being 85 feet, and the exterior was very gaily decorated. A short, cylindrical opening was made at the lower extremity, and under this a fire-pan was suspended, above the passenger car of the balloon. On October 15th, 1783, Pilatre de Rozier made the first balloon ascent--but the balloon was held captive, and only allowed to rise to a height of 80 feet. But, a little later in 1783, Rozier secured the honour of making the first ascent in a free balloon, taking up with him the Marquis d'Arlandes. It had been originally intended that two criminals, condemned to death, should risk their lives in the perilous venture, with the prospect of a free pardon if they made a safe descent, but d'Arlandes got the royal consent to accompany Rozier, and the criminals lost their chance. Rozier and d'Arlandes made a voyage lasting for twenty-five minutes, and, on landing, the balloon collapsed with such rapidity as almost to suffocate Rozier, who, however, was dragged out to safety by d'Arlandes. This first aerostatic journey took place on November 21st, 1783. Some seven months later, on June 4th, 1784, a Madame Thible ascended in a free balloon, reaching a height of 9,000 feet, and making a journey which lasted for forty-five minutes--the great King Gustavus of Sweden witnessed this ascent. France grew used to balloon ascents in the course of a few months, in spite of the brewing of such a storm as might have been calculated to wipe out all but purely political interests. Meanwhile, interest in the new discovery spread across the Channel, and on September 15th, 1784, one Vincent Lunardi made the first balloon voyage in England, starting from the Artillery Ground at Chelsea, with a cat and dog as passengers, and landing in a field in the parish of Standon, near Ware. There is a rather rare book which gives a very detailed account of this first ascent in England, one copy of which is in the library of the Royal Aeronautical Society; the venturesome Lunardi won a greater measure of fame through his exploit than did Cody for his infinitely more courageous and--from a scientific point of view--valuable first aeroplane ascent in this country. The Montgolfier type of balloon, depending on hot air for its lifting power, was soon realised as having dangerous limitations. There was always a possibility of the balloon catching fire while it was being filled, and on landing there was further danger from the hot pan which kept up the supply of hot air on the voyage--the collapsing balloon fell on the pan, inevitably. The scientist Saussure, observing the filling of the balloons very carefully, ascertained that it was rarefaction of the air which was responsible for the lifting power, and not the heat in itself, and, owing to the rarefaction of the air at normal temperature at great heights above the earth, the limit of ascent for a balloon of the Montgolfier type was estimated by him at under 9,000 feet. Moreover, since the amount of fuel that could be carried for maintaining the heat of the balloon after inflation was subject to definite limits, prescribed by the carrying capacity of the balloon, the duration of the journey was necessarily limited just as strictly. These considerations tended to turn the minds of those interested in aerostation to consideration of the hydrogen balloon evolved by Professor Charles. Certain improvements had been made by Charles since his first construction; he employed rubber-coated silk in the construction of a balloon of 30 feet diameter, and provided a net for distributing the pressure uniformly over the surface of the envelope; this net covered the top half of the balloon, and from its lower edge dependent ropes hung to join on a wooden ring, from which the car of the balloon was suspended--apart from the extension of the net so as to cover in the whole of the envelope, the spherical balloon of to-day is virtually identical with that of Charles in its method of construction. He introduced the valve at the top of the balloon, by which escape of gas could be controlled, operating his valve by means of ropes which depended to the car of the balloon, and he also inserted a tube, of about 7 inches diameter, at the bottom of the balloon, not only for purposes of inflation, but also to provide a means of escape for gas in case of expansion due to atmospheric conditions. Sulphuric acid and iron filings were used by Charles for filling his balloon, which required three days and three nights for the generation of its 14,000 cubic feet of hydrogen gas. The inflation was completed on December 1st, 1783, and the fittings carried included a barometer and a grapnel form of anchor. In addition to this, Charles provided the first 'ballon sonde' in the form of a small pilot balloon which he handed to Montgolfier to launch before his own ascent, in order to determine the direction and velocity of the wind. It was a graceful compliment to his rival, and indicated that, although they were both working to the one end, their rivalry was not a matter of bitterness. Ascending on December 1st, 1783, Charles took with him one of the brothers Robert, and with him made the record journey up to that date, covering a period of three and three-quarter hours, in which time they journeyed some forty miles. Robert then landed, and Charles ascended again alone, reaching such a height as to feel the effects of the rarefaction of the air, this very largely due to the rapidity of his ascent. Opening the valve at the top of the balloon, he descended thirty-five minutes after leaving Robert behind, and came to earth a few miles from the point of the first descent. His discomfort over the rapid ascent was mainly due to the fact that, when Robert landed, he forgot to compensate for the reduction of weight by taking in further ballast, but the ascent proved the value of the tube at the bottom of the balloon envelope, for the gas escaped very rapidly in that second ascent, and, but for the tube, the balloon must inevitably have burst in the air, with fatal results for Charles. As in the case of aeroplane flight, as soon as the balloon was proved practicable the flight across the English Channel was talked of, and Rozier, who had the honour of the first flight, announced his intention of being first to cross. But Blanchard, who had an idea for a 'flying car,' anticipated him, and made a start from Dover on January 7th, 1785, taking with him an American doctor named Jeffries. Blanchard fitted out his craft for the journey very thoroughly, taking provisions, oars, and even wings, for propulsion in case of need. He took so much, in fact, that as soon as the balloon lifted clear of the ground the whole of the ballast had to be jettisoned, lest the balloon should drop into the sea. Half-way across the Channel the sinking of the balloon warned Blanchard that he had to part with more than ballast to accomplish the journey, and all the equipment went, together with certain books and papers that were on board the car. The balloon looked perilously like collapsing, and both Blanchard and Jeffries began to undress in order further to lighten their craft--Jeffries even proposed a heroic dive to save the situation, but suddenly the balloon rose sufficiently to clear the French coast, and the two voyagers landed at a point near Calais in the Forest of Gaines, where a marble column was subsequently erected to commemorate the great feat. Rozier, although not first across, determined to be second, and for that purpose he constructed a balloon which was to owe its buoyancy to a combination of the hydrogen and hot air principles. There was a spherical hydrogen balloon above, and beneath it a cylindrical container which could be filled with hot air, thus compensating for the leakage of gas from the hydrogen portion of the balloon--regulating the heat of his fire, he thought, would give him perfect control in the matter of ascending and descending. On July 6th, 1785, a favourable breeze gave Rozier his opportunity of starting from the French coast, and with a passenger aboard he cast off in his balloon, which he had named the 'Aero-Montgolfiere.' There was a rapid rise at first, and then for a time the balloon remained stationary over the land, after which a cloud suddenly appeared round the balloon, denoting that an explosion had taken place. Both Rozier and his companion were killed in the fall, so that he, first to leave the earth by balloon, was also first victim to the art of aerostation. There followed, naturally, a lull in the enthusiasm with which ballooning had been taken up, so far as France was concerned. In Italy, however, Count Zambeccari took up hot-air ballooning, using a spirit lamp to give him buoyancy, and on the first occasion when the balloon car was set on fire Zambeccari let down his passenger by means of the anchor rope, and managed to extinguish the fire while in the air. This reduced the buoyancy of the balloon to such an extent that it fell into the Adriatic and was totally wrecked, Zambeccari being rescued by fishermen. He continued to experiment up to 1812, when he attempted to ascend at Bologna; the spirit in his lamp was upset by the collision of the car with a tree, and the car was again set on fire. Zambeccari jumped from the car when it was over fifty feet above level ground, and was killed. With him the Rozier type of balloon, combining the hydrogen and hot air principles, disappeared; the combination was obviously too dangerous to be practical. The brothers Robert were first to note how the heat of the sun acted on the gases within a balloon envelope, and it has since been ascertained that sun rays will heat the gas in a balloon to as much as 80 degrees Fahrenheit greater temperature than the surrounding atmosphere; hydrogen, being less affected by change of temperature than coal gas, is the most suitable filling element, and coal gas comes next as the medium of buoyancy. This for the free and non-navigable balloon, though for the airship, carrying means of combustion, and in military work liable to ignition by explosives, the gas helium seems likely to replace hydrogen, being non-combustible. In spite of the development of the dirigible airship, there remains work for the free, spherical type of balloon in the scientific field. Blanchard's companion on the first Channel crossing by balloon, Dr Jeffries, was the first balloonist to ascend for purely scientific purposes; as early as 1784 he made an ascent to a height of 9,000 feet, and observed a fall in temperature of from degrees--at the level of London, where he began his ascent--to 29 degrees at the maximum height reached. He took up an electrometer, a hydrometer, a compass, a thermometer, and a Toricelli barometer, together with bottles of water, in order to collect samples of the air at different heights. In 1785 he made a second ascent, when trigonometrical observations of the height of the balloon were made from the French coast, giving an altitude of 4,800 feet. The matter was taken up on its scientific side very early in America, experiments in Philadelphia being almost simultaneous with those of the Montgolfiers in France. The flight of Rozier and d'Arlandes inspired two members of the Philadelphia Philosophical Academy to construct a balloon or series of balloons of their own design; they made a machine which consisted of no less than 47 small hydrogen balloons attached to a wicker car, and made certain preliminary trials, using animals as passengers. This was followed by a captive ascent with a man as passenger, and eventually by the first free ascent in America, which was undertaken by one James Wilcox, a carpenter, on December 28th, 1783. Wilcox, fearful of falling into a river, attempted to regulate his landing by cutting slits in some of the supporting balloons, which was the method adopted for regulating ascent or descent in this machine. He first cut three, and then, finding that the effect produced was not sufficient, cut three more, and then another five--eleven out of the forty-seven. The result was so swift a descent that he dislocated his wrist on landing. A NOTE ON BALLONETS OR AIR BAGS. Meusnier, toward the end of the eighteenth century, was first to conceive the idea of compensating for the loss of gas due to expansion by fitting to the interior of a free balloon a ballonet, or air bag, which could be pumped full of air so as to retain the shape and rigidity of the envelope. The ballonet became particularly valuable as soon as airship construction became general, and it was in the course of advance in Astra Torres design that the project was introduced of using the ballonets in order to give inclination from the horizontal. In the earlier Astra Torres, trimming was accomplished by moving the car fore and aft--this in itself was an advance on the separate 'sliding weigh' principle--and this was the method followed in the Astra Torres bought by the British Government from France in 1912 for training airship pilots. Subsequently, the two ballonets fitted inside the envelope were made to serve for trimming by the extent of their inflation, and this method of securing inclination proved the best until exterior rudders, and greater engine power, supplanted it, as in the Zeppelin and, in fact, all rigid types. In the kite balloon, the ballonet serves the purpose of a rudder, filling itself through the opening being kept pointed toward the wind--there is an ingenious type of air scoop with non-return valve which assures perfect inflation. In the S.S. type of airship, two ballonets are provided, the supply of air being taken from the propeller draught by a slanting aluminium tube to the underside of the envelope, where it meets a longitudinal fabric hose which connects the two ballonet air inlets. In this hose the non-return air valves, known as 'crab-pots,' are fitted, on either side of the junction with the air-scoop. Two automatic air valves, one for each ballonet, are fitted in the underside of the envelope, and, as the air pressure tends to open these instead of keeping them shut, the spring of the valve is set inside the envelope. Each spring is set to open at a pressure of 25 to 28 mm. II. THE FIRST DIRIGIBLES Having got off the earth, the very early balloonists set about the task of finding a means of navigating the air but, lacking steam or other accessory power to human muscle, they failed to solve the problem. Joseph Montgolfier speedily exploded the idea of propelling a balloon either by means of oars or sails, pointing out that even in a dead calm a speed of five miles an hour would be the limit achieved. Still, sailing balloons were constructed, even up to the time of Andree, the explorer, who proposed to retard the speed of the balloon by ropes dragging on the ground, and then to spread a sail which should catch the wind and permit of deviation of the course. It has been proved that slight divergences from the course of the wind can be obtained by this means, but no real navigation of the air could be thus accomplished. Professor Wellner, of Brunn, brought up the idea of a sailing balloon in more practical fashion in 1883. He observed that surfaces inclined to the horizontal have a slight lateral motion in rising and falling, and deduced that by alternate lowering and raising of such surfaces he would be able to navigate the air, regulating ascent and descent by increasing or decreasing the temperature of his buoyant medium in the balloon. He calculated that a balloon, 50 feet in diameter and 150 feet in length, with a vertical surface in front and a horizontal surface behind, might be navigated at a speed of ten miles per hour, and in actual tests at Brunn he proved that a single rise and fall moved the balloon three miles against the wind. His ideas were further developed by Lebaudy in the construction of the early French dirigibles. According to Hildebrandt,[*] the first sailing balloon was built in 1784 by Guyot, who made his balloon egg-shaped, with the smaller end at the back and the longer axis horizontal; oars were intended to propel the craft, and naturally it was a failure. Carra proposed the use of paddle wheels, a step in the right direction, by mounting them on the sides of the car, but the improvement was only slight. Guyton de Morveau, entrusted by the Academy of Dijon with the building of a sailing balloon, first used a vertical rudder at the rear end of his construction--it survives in the modern dirigible. His construction included sails and oars, but, lacking steam or other than human propulsive power, the airship was a failure equally with Guyot's. [*] Airships Past and Present. Two priests, Miollan and Janinet, proposed to drive balloons through the air by the forcible expulsion of the hot air in the envelope from the rear of the balloon. An opening was made about half-way up the envelope, through which the hot air was to escape, buoyancy being maintained by a pan of combustibles in the car. Unfortunately, this development of the Montgolfier type never got a trial, for those who were to be spectators of the first flight grew exasperated at successive delays, and in the end, thinking that the balloon would never rise, they destroyed it. Meusnier, a French general, first conceived the idea of compensating for loss of gas by carrying an air bag inside the balloon, in order to maintain the full expansion of the envelope. The brothers Robert constructed the first balloon in which this was tried and placed the air bag near the neck of the balloon which was intended to be driven by oars, and steered by a rudder. A violent swirl of wind which was encountered on the first ascent tore away the oars and rudder and broke the ropes which held the air bag in position; the bag fell into the opening of the neck and stopped it up, preventing the escape of gas under expansion. The Duc de Chartres, who was aboard, realised the extreme danger of the envelope bursting as the balloon ascended, and at 16,000 feet he thrust a staff through the envelope--another account says that he slit it with his sword--and thus prevented disaster. The descent after this rip in the fabric was swift, but the passengers got off without injury in the landing. Meusnier, experimenting in various ways, experimented with regard to the resistance offered by various shapes to the air, and found that an elliptical shape was best; he proposed to make the car boat--shaped, in order further to decrease the resistance, and he advocated an entirely rigid connection between the car and the body of the balloon, as indispensable to a dirigible.[*] He suggested using three propellers, which were to be driven by hand by means of pulleys, and calculated that a crew of eighty would be required to furnish sufficient motive power. Horizontal fins were to be used to assure stability, and Meusnier thoroughly investigated the pressures exerted by gases, in order to ascertain the stresses to which the envelope would be subjected. More important still, he went into detail with regard to the use of air bags, in order to retain the shape of the balloon under varying pressures of gas due to expansion and consequent losses; he proposed two separate envelopes, the inner one containing gas, and the space between it and the outer one being filled with air. Further, by compressing the air inside the air bag, the rate of ascent or descent could be regulated. Lebaudy, acting on this principle, found it possible to pump air at the rate of 35 cubic feet per second, thus making good loss of ballast which had to be thrown overboard. [*] Hildebrandt. Meusnier's balloon, of course, was never constructed, but his ideas have been of value to aerostation up to the present time. His career ended in the revolutionary army in 1793, when he was killed in the fighting before Mayence, and the King of Prussia ordered all firing to cease until Meusnier had been buried. No other genius came forward to carry on his work, and it was realised that human muscle could not drive a balloon with certainty through the air; experiment in this direction was abandoned for nearly sixty years, until in 1852 Giffard brought the first practicable power-driven dirigible to being. Giffard, inventor of the steam injector, had already made balloon ascents when he turned to aeronautical propulsion, and constructed a steam engine of 5 horsepower with a weight of only 100 lbs.--a great achievement for his day. Having got his engine, he set about making the balloon which it was to drive; this he built with the aid of two other enthusiasts, diverging from Meusnier's ideas by making the ends pointed, and keeping the body narrowed from Meusnier's ellipse to a shape more resembling a rather fat cigar. The length was 144 feet, and the greatest diameter only 40 feet, while the capacity was 88,000 cubic feet. A net which covered the envelope of the balloon supported a spar, 66 feet in length, at the end of which a triangular sail was placed vertically to act as rudder. The car, slung 20 feet below the spar, carried the engine and propeller. Engine and boiler together weighed 350 lbs., and drove the 11 foot propeller at 110 revolutions per minute. As precaution against explosion, Giffard arranged wire gauze in front of the stoke-hole of his boiler, and provided an exhaust pipe which discharged the waste gases from the engine in a downward direction. With this first dirigible he attained to a speed of between 6 and 8 feet per second, thus proving that the propulsion of a balloon was a possibility, now that steam had come to supplement human effort. Three years later he built a second dirigible, reducing the diameter and increasing the length of the gas envelope, with a view to reducing air resistance. The length of this was 230 feet, the diameter only 33 feet, and the capacity was 113,000 cubic feet, while the upper part of the envelope, to which the covering net was attached, was specially covered to ensure a stiffening effect. The car of this dirigible was dropped rather lower than that of the first machine, in order to provide more thoroughly against the danger of explosions. Giffard, with a companion named Yon as passenger, took a trial trip on this vessel, and made a journey against the wind, though slowly. In commencing to descend, the nose of the envelope tilted upwards, and the weight of the car and its contents caused the net to slip, so that just before the dirigible reached the ground, the envelope burst. Both Giffard and his companion escaped with very slight injuries. Plans were immediately made for the construction of a third dirigible, which was to be 1,970 feet in length, 98 feet in extreme diameter, and to have a capacity of 7,800,000 cubic feet of gas. The engine of this giant was to have weighed 30 tons, and with it Giffard expected to attain a speed of 40 miles per hour. Cost prevented the scheme being carried out, and Giffard went on designing small steam engines until his invention of the steam injector gave him the funds to turn to dirigibles again. He built a captive balloon for the great exhibition in London in 1868, at a cost of nearly L30,000, and designed a dirigible balloon which was to have held a million and three quarters cubic feet of gas, carry two boilers, and cost about L40,000. The plans were thoroughly worked out, down to the last detail, but the dirigible was never constructed. Giffard went blind, and died in 1882--he stands as the great pioneer of dirigible construction, more on the strength of the two vessels which he actually built than on that of the ambitious later conceptions of his brain. In 1872 Dupuy de Lome, commissioned by the French government, built a dirigible which he proposed to drive by man-power--it was anticipated that the vessel would be of use in the siege of Paris, but it was not actually tested till after the conclusion of the war. The length of this vessel was 118 feet, its greatest diameter 49 feet, the ends being pointed, and the motive power was by a propeller which was revolved by the efforts of eight men. The vessel attained to about the same speed as Giffard's steam-driven airship; it was capable of carrying fourteen men, who, apart from these engaged in driving the propeller, had to manipulate the pumps which controlled the air bags inside the gas envelope. In the same year Paul Haenlein, working in Vienna, produced an airship which was a direct forerunner of the Lebaudy type, 164 feet in length, 30 feet greatest diameter, and with a cubic capacity of 85,000 feet. Semi-rigidity was attained by placing the car as close to the envelope as possible, suspending it by crossed ropes, and the motive power was a gas engine of the Lenoir type, having four horizontal cylinders, and giving about 5 horse-power with a consumption of about 250 cubic feet of gas per hour. This gas was sucked from the envelope of the balloon, which was kept fully inflated by pumping in compensating air to the air bags inside the main envelope. A propeller, 15 feet in diameter, was driven by the Lenoir engine at 40 revolutions per minute. This was the first instance of the use of an internal combustion engine in connection with aeronautical experiments. The envelope of this dirigible was rendered airtight by means of internal rubber coating, with a thinner film on the outside. Coal gas, used for inflation, formed a suitable fuel for the engine, but limited the height to which the dirigible could ascend. Such trials as were made were carried out with the dirigible held captive, and a speed of I 5 feet per second was attained. Full experiment was prevented through funds running low, but Haenlein's work constituted a distinct advance on all that had been done previously. Two brothers, Albert and Gaston Tissandier, were next to enter the field of dirigible construction; they had experimented with balloons during the Franc-Prussian War, and had attempted to get into Paris by balloon during the siege, but it was not until 1882 that they produced their dirigible. This was 92 feet in length and 32 feet in greatest diameter, with a cubic capacity of 37,500 feet, and the fabric used was varnished cambric. The car was made of bamboo rods, and in addition to its crew of three, it carried a Siemens dynamo, with 24 bichromate cells, each of which weighed 17 lbs. The motor gave out 1 1/2 horse-power, which was sufficient to drive the vessel at a speed of up to 10 feet per second. This was not so good as Haenlein's previous attempt and, after L2,000 had been spent, the Tissandier abandoned their experiments, since a 5-mile breeze was sufficient to nullify the power of the motor. Renard, a French officer who had studied the problem of dirigible construction since 1878, associated himself first with a brother officer named La Haye, and subsequently with another officer, Krebs, in the construction of the second dirigible to be electrically-propelled. La Haye first approached Colonel Laussedat, in charge of the Engineers of the French Army, with a view to obtaining funds, but was refused, in consequence of the practical failure of all experiments since 1870. Renard, with whom Krebs had now associated himself, thereupon went to Gambetta, and succeeded in getting a promise of a grant of L8,000 for the work; with this promise Renard and Krebs set to work. They built their airship in torpedo shape, 165 feet in length, and of just over 27 feet greatest diameter--the greatest diameter was at the front, and the cubic capacity was 66,000 feet. The car itself was 108 feet in length, and 4 1/2 feet broad, covered with silk over the bamboo framework. The 23 foot diameter propeller was of wood, and was driven by an electric motor connected to an accumulator, and yielding 8.5 horsepower. The sweep of the propeller, which might have brought it in contact with the ground in landing, was counteracted by rendering it possible to raise the axis on which the blades were mounted, and a guide rope was used to obviate damage altogether, in case of rapid descent. There was also a 'sliding weight' which was movable to any required position to shift the centre of gravity as desired. Altogether, with passengers and ballast aboard, the craft weighed two tons. In the afternoon of August 8th, 1884, Renard and Krebs ascended in the dirigible--which they had named 'La France,' from the military ballooning ground at Chalais-Meudon, making a circular flight of about five miles, the latter part of which was in the face of a slight wind. They found that the vessel answered well to her rudder, and the five-mile flight was made successfully in a period of 23 minutes. Subsequent experimental flights determined that the air speed of the dirigible was no less than 14 1/2 miles per hour, by far the best that had so far been accomplished in dirigible flight. Seven flights in all were made, and of these five were completely successful, the dirigible returning to its starting point with no difficulty. On the other two flights it had to be towed back. Renard attempted to repeat his construction on a larger scale, but funds would not permit, and the type was abandoned; the motive power was not sufficient to permit of more than short flights, and even to the present time electric motors, with their necessary accumulators, are far too cumbrous to compete with the self-contained internal combustion engine. France had to wait for the Lebaudy brothers, just as Germany had to wait for Zeppelin and Parseval. Two German experimenters, Baumgarten and Wolfert, fitted a Daimler motor to a dirigible balloon which made its first ascent at Leipzig in 1880. This vessel had three cars, and placing a passenger in one of the outer cars[*] distributed the load unevenly, so that the whole vessel tilted over and crashed to the earth, the occupants luckily escaping without injury. After Baumgarten's death, Wolfert determined to carry on with his experiments, and, having achieved a certain measure of success, he announced an ascent to take place on the Tempelhofer Field, near Berlin, on June 12th, 1897. The vessel, travelling with the wind, reached a height of 600 feet, when the exhaust of the motor communicated flame to the envelope of the balloon, and Wolfert, together with a passenger he carried, was either killed by the fall or burnt to death on the ground. Giffard had taken special precautions to avoid an accident of this nature, and Wolfert, failing to observe equal care, paid the full penalty. [*] Hildebrandt. Platz, a German soldier, attempting an ascent on the Tempelhofer Field in the Schwartz airship in 1897, merely proved the dirigible a failure. The vessel was of aluminium, 0.008 inch in thickness, strengthened by an aluminium lattice work; the motor was two-cylindered petrol-driven; at the first trial the metal developed such leaks that the vessel came to the ground within four miles of its starting point. Platz, who was aboard alone as crew, succeeded in escaping by jumping clear before the car touched earth, but the shock of alighting broke up the balloon, and a following high wind completed the work of full destruction. A second account says that Platz, finding the propellers insufficient to drive the vessel against the wind, opened the valve and descended too rapidly. The envelope of this dirigible was 156 feet in length, and the method of filling was that of pushing in bags, fill them with gas, and then pulling them to pieces and tearing them out of the body of the balloon. A second contemplated method of filling was by placing a linen envelope inside the aluminium casing, blowing it out with air, and then admitting the gas between the linen and the aluminium outer casing. This would compress the air out of the linen envelope, which was to be withdrawn when the aluminium casing had been completely filled with gas. All this, however, assumes that the Schwartz type--the first rigid dirigible, by the way--would prove successful. As it proved a failure on the first trial, the problem of filling it did not arise again. By this time Zeppelin, retired from the German army, had begun to devote himself to the study of dirigible construction, and, a year after Schwartz had made his experiment and had failed, he got together sufficient funds for the formation of a limitedliability company, and started on the construction of the first of his series of airships. The age of tentative experiment was over, and, forerunner of the success of the heavier-than-air type of flying machine, successful dirigible flight was accomplished by Zeppelin in Germany, and by Santos-Dumont in France. III. SANTOS-DUMONT A Brazilian by birth, Santos-Dumont began in Paris in the year 1898 to make history, which he subsequently wrote. His book, My Airships, is a record of his eight years of work on lighter-than-air machines, a period in which he constructed no less than fourteen dirigible balloons, beginning with a cubic capacity of 6,350 feet, and an engine of 3 horse-power, and rising to a cubic capacity of 71,000 feet on the tenth dirigible he constructed, and an engine of 60 horse-power, which was fitted to the seventh machine in order of construction, the one which he built after winning the Deutsch Prize. The student of dirigible construction is recommended to Santos-Dumont's own book not only as a full record of his work, but also as one of the best stories of aerial navigation that has ever been written. Throughout all his experiments, he adhered to the non-rigid type; his first dirigible made its first flight on September 18th, 1898, starting from the Jardin d'Acclimatation to the west of Paris; he calculated that his 3 horse-power engine would yield sufficient power to enable him to steer clear of the trees with which the starting-point was surrounded, but, yielding to the advice of professional aeronauts who were present, with regard to the placing of the dirigible for his start, he tore the envelope against the trees. Two days later, having repaired the balloon, he made an ascent of 1,300 feet. In descending, the hydrogen left in the balloon contracted, and Santos-Dumont narrowly escaped a serious accident in coming to the ground. His second machine, built in the early spring of 1899, held over 7,000 cubic feet of gas and gave a further 44 lbs. of ascensional force. The balloon envelope was very long and very narrow; the first attempt at flight was made in wind and rain, and the weather caused sufficient contraction of the hydrogen for a wind gust to double the machine up and toss it into the trees near its starting-point. The inventor immediately set about the construction of 'Santos-Dumont No. 3,' on which he made a number of successful flights, beginning on November 13th, 1899. On the last of his flights, he lost the rudder of the machine and made a fortunate landing at Ivry. He did not repair the balloon, considering it too clumsy in form and its motor too small. Consequently No. 4 was constructed, being finished on the 1st, August, 1900. It had a cubic capacity of 14,800 feet, a length of 129 feet and greatest diameter of 16.7 feet, the power plant being a 7 horse-power Buchet motor. Santos-Dumont sat on a bicycle saddle fixed to the long bar suspended under the machine, which also supported motor propeller, ballast; and fuel. The experiment of placing the propeller at the stem instead of at the stern was tried, and the motor gave it a speed of 100 revolutions per minute. Professor Langley witnessed the trials of the machine, which proved before the members of the International Congress of Aeronautics, on September 19th, that it was capable of holding its own against a strong wind. Finding that the cords with which his dirigible balloon cars were suspended offered almost as much resistance to the air as did the balloon itself, Santos-Dumont substituted piano wire and found that the alteration constituted greater progress than many a more showy device. He altered the shape and size of his No. 4 to a certain extent and fitted a motor of 12 horse-power. Gravity was controlled by shifting weights worked by a cord; rudder and propeller were both placed at the stern. In Santos-Dumont's book there is a certain amount of confusion between the No. 4 and No. 5 airships, until he explains that 'No. 5' is the reconstructed 'No. 4.' It was with No. 5 that he won the Encouragement Prize presented by the Scientific Commission of the Paris Aero Club. This he devoted to the first aeronaut who between May and October of 1900 should start from St Cloud, round the Eiffel Tower, and return. If not won in that year, the prize was to remain open the following year from May 1st to October 1st, and so on annually until won. This was a simplification of the conditions of the Deutsch Prize itself, the winning of which involved a journey of 11 kilometres in 30 minutes. The Santos-Dumont No. 5, which was in reality the modified No. 4 with new keel, motor, and propeller, did the course of the Deutsch Prize, but with it Santos-Dumont made no attempt to win the prize until July of 1901, when he completed the course in 40 minutes, but tore his balloon in landing. On the 8th August, with his balloon leaking, he made a second attempt, and narrowly escaped disaster, the airship being entirely wrecked. Thereupon he built No. 6 with a cubic capacity of 22,239 feet and a lifting power of 1,518 lbs. With this machine he won the Deutsch Prize on October 19th, 1901, starting with the disadvantage of a side wind of 20 feet per second. He reached the Eiffel Tower in 9 minutes and, through miscalculating his turn, only just missed colliding with it. He got No. 6 under control again and succeeded in getting back to his starting-point in 29 1/2 minutes, thus winning the 125,000 francs which constituted the Deutsch Prize, together with a similar sum granted to him by the Brazilian Government for the exploit. The greater part of this money was given by Santos-Dumont to charities. He went on building after this until he had made fourteen non-rigid dirigibles; of these No. 12 was placed at the disposal of the military authorities, while the rest, except for one that was sold to an American and made only one trip, were matters of experiment for their maker. His conclusions from his experiments may be gathered from his own work:-- 'On Friday, 31st July, 1903, Commandant Hirschauer and Lieutenant-Colonel Bourdeaux spent the afternoon with me at my airship station at Neuilly St James, where I had my three newest airships--the racing 'No. 7,' the omnibus 'No. 10,' and the runabout 'No. 9'--ready for their study. Briefly, I may say that the opinions expressed by the representatives of the Minister of War were so unreservedly favourable that a practical test of a novel character was decided to be made. Should the airship chosen pass successfully through it the result will be conclusive of its military value. 'Now that these particular experiments are leaving my exclusively private control I will say no more of them than what has been already published in the French press. The test will probably consist of an attempt to enter one of the French frontier towns, such as Belfort or Nancy, on the same day that the airship leaves Paris. It will not, of course, be necessary to make the whole journey in the airship. A military railway wagon may be assigned to carry it, with its balloon uninflated, with tubes of hydrogen to fill it, and with all the necessary machinery and instruments arranged beside it. At some station a short distance from the town to be entered the wagon may be uncoupled from the train, and a sufficient number of soldiers accompanying the officers will unload the airship and its appliances, transport the whole to the nearest open space, and at once begin inflating the balloon. Within two hours from quitting the train the airship may be ready for its flight to the interior of the technically-besieged town. 'Such may be the outline of the task--a task presented imperiously to French balloonists by the events of 1870-1, and which all the devotion and science of the Tissandier brothers failed to accomplish. To-day the problem may be set with better hope of success. All the essential difficulties may be revived by the marking out of a hostile zone around the town that must be entered; from beyond the outer edge of this zone, then, the airship will rise and take its flight--across it. 'Will the airship be able to rise out of rifle range? I have always been the first to insist that the normal place of the airship is in low altitudes, and I shall have written this book to little purpose if I have not shown the reader the real dangers attending any brusque vertical mounting to considerable heights. For this we have the terrible Severo accident before our eyes. In particular, I have expressed astonishment at hearing of experimenters rising to these altitudes without adequate purpose in their early stages of experience with dirigible balloons. All this is very different, however, from a reasoned, cautious mounting, whose necessity has been foreseen and prepared for.' Probably owing to the fact that his engines were not of sufficient power, Santos-Dumont cannot be said to have solved the problem of the military airship, although the French Government bought one of his vessels. At the same time, he accomplished much in furthering and inciting experiment with dirigible airships, and he will always rank high among the pioneers of aerostation. His experiments might have gone further had not the Wright brothers' success in America and French interest in the problem of the heavier-than-air machine turned him from the study of dirigibles to that of the aeroplane, in which also he takes high rank among the pioneers, leaving the construction of a successful military dirigible to such men as the Lebaudy brothers, Major Parseval, and Zeppelin. IV. THE MILITARY DIRIGIBLE Although French and German experiment in connection with the production of an airship which should be suitable for military purposes proceeded side by side, it is necessary to outline the development in the two countries separately, owing to the differing character of the work carried out. So far as France is concerned, experiment began with the Lebaudy brothers, originally sugar refiners, who turned their energies to airship construction in 1899. Three years of work went to the production of their first vessel, which was launched in 1902, having been constructed by them together with a balloon manufacturer named Surcouf and an engineer, Julliot. The Lebaudy airships were what is known as semi-rigids, having a spar which ran practically the full length of the gas bag to which it was attached in such a way as to distribute the load evenly. The car was suspended from the spar, at the rear end of which both horizontal and vertical rudders were fixed, whilst stabilising fins were provided at the stern of the gas envelope itself. The first of the Lebaudy vessels was named the 'Jaune'; its length was 183 feet and its maximum diameter 30 feet, while the cubic capacity was 80,000 feet. The power unit was a 40 horse-power Daimler motor, driving two propellers and giving a maximum speed of 26 miles per hour. This vessel made 29 trips, the last of which took place in November, 1902, when the airship was wrecked through collision with a tree. The second airship of Lebaudy construction was 7 feet longer than the first, and had a capacity of 94,000 cubic feet of gas with a triple air bag of 17,500 cubic feet to compensate for loss of gas; this latter was kept inflated by a rotary fan. The vessel was eventually taken over by the French Government and may be counted the first dirigible airship considered fit on its tests for military service. Later vessels of the Lebaudy type were the 'Patrie' and 'Republique,' in which both size and method of construction surpassed those of the two first attempts. The 'Patrie' was fitted with a 60 horse-power engine which gave a speed of 28 miles an hour, while the vessel had a radius of 280 miles, carrying a crew of nine. In the winter of 1907 the 'Patrie' was anchored at Verdun, and encountered a gale which broke her hold on her mooring-ropes. She drifted derelict westward across France, the Channel, and the British Isles, and was lost in the Atlantic. The 'Republique' had an 80 horse-power motor, which, however, only gave her the same speed as the 'Patrie.' She was launched in July, 1908, and within three months came to an end which constituted a tragedy for France. A propeller burst while the vessel was in the air, and one blade, flying toward the envelope, tore in it a great gash; the airship crashed to earth, and the two officers and two non-commissioned officers who were in the car were instantaneously killed. The Clement Bayard, and subsequently the Astra-Torres, non-rigids, followed on the early Lebaudys and carried French dirigible construction up to 1912. The Clement Bayard was a simple non-rigid having four lobes at the stern end to assist stability. These were found to retard the speed of the airship, which in the second and more successful construction was driven by a Clement Bayard motor of 100 horse-power at a speed of 30 miles an hour. On August 23rd, 1909, while being tried for acceptance by the military authorities, this vessel achieved a record by flying at a height of 5,000 feet for two hours. The Astra-Torres non-rigids were designed by a Spaniard, Senor Torres, and built by the Astra Company. The envelope was of trefoil shape, this being due to the interior rigging from the suspension band; the exterior appearance is that of two lobes side by side, overlaid by a third. The interior rigging, which was adopted with a view to decreasing air resistance, supports a low-hung car from the centre of the envelope; steering is accomplished by means of horizontal planes fixed on the envelope at the stern, and vertical planes depending beneath the envelope, also at the stern end. One of the most successful of French pre-war dirigibles was a Clement Bayard built in 1912. In this twin propellers were placed at the front and horizontal and vertical rudders in a sort of box formation under the envelope at the stern. The envelope was stream-lined, while the car of the machine was placed well forward with horizontal controlling planes above it and immediately behind the propellers. This airship, which was named 'Dupuy de Lome,' may be ranked as about the most successful non-rigid dirigible constructed prior to the War. Experiments with non-rigids in Germany was mainly carried on by Major Parseval, who produced his first vessel in 1906. The main feature of this airship consisted in variation in length of the suspension cables at the will of the operator, so that the envelope could be given an upward tilt while the car remained horizontal in order to give the vessel greater efficiency in climbing. In this machine, the propeller was placed above and forward of the car, and the controlling planes were fixed directly to the envelope near the forward end. A second vessel differed from the first mainly in the matter of its larger size, variable suspension being again employed, together with a similar method of control. The vessel was moderately successful, and under Major Parseval's direction a third was constructed for passenger carrying, with two engines of 120 horsepower, each driving propellers of 13 feet diameter. This was the most successful of the early German dirigibles; it made a number of voyages with a dozen passengers in addition to its crew, as well as proving its value for military purposes by use as a scout machine in manoeuvres. Later Parsevals were constructed of stream-line form, about 300 feet in length, and with engines sufficiently powerful to give them speeds up to 50 miles an hour. Major Von Gross, commander of a Balloon Battalion, produced semi-rigid dirigibles from 1907 onward. The second of these, driven by two 75 horse-power Daimler motors, was capable of a speed of 27 miles an hour; in September of 1908 she made a trip from and back to Berlin which lasted 13 hours, in which period she covered 176 miles with four passengers and reached a height of 4,000 feet. Her successor, launched in April of 1909, carried a wireless installation, and the next to this, driven by four motors of 75 horse-power each, reached a speed of 45 miles an hour. As this vessel was constructed for military purposes, very few details either of its speed or method of construction were made public. Practically all these vessels were discounted by the work of Ferdinand von Zeppelin, who set out from the first with the idea of constructing a rigid dirigible. Beginning in 1898, he built a balloon on an aluminium framework covered with linen and silk, and divided into interior compartments holding linen bags which were capable of containing nearly 400,000 cubic feet of hydrogen. The total length of this first Zeppelin airship was 420 feet and the diameter 38 feet. Two cars were rigidly attached to the envelope, each carrying a 16 horse-power motor, driving propellers which were rigidly connected to the aluminium framework of the balloon. Vertical and horizontal screws were used for lifting and forward driving and a sliding weight was used to raise or lower the stem of the vessel out of the horizontal in order to rise or descend without altering the load by loss of ballast or the lift by loss of gas. The first trial of this vessel was made in July of 1900, and was singularly unfortunate. The winch by which the sliding weight was operated broke, and the balloon was so bent that the working of the propellers was interfered with, as was the steering. A speed of 13 feet per second was attained, but on descending, the airship ran against some piles and was further damaged. Repairs were completed by the end of September, 1900, and on a second trial flight made on October 21st a speed of 30 feet per second was reached. Zeppelin was far from satisfied with the performance of this vessel, and he therefore set about collecting funds for the construction of a second, which was completed in 1905. By this time the internal combustion engine had been greatly improved, and without any increase of weight, Zeppelin was able to instal two motors of 85 horse-power each. The total capacity was 367,000 cubic feet of hydrogen, carried in 16 gas bags inside the framework, and the weight of the whole construction was 9 tons--a ton less than that of the first Zeppelin airship. Three vertical planes at front and rear controlled horizontal steering, while rise and fall was controlled by horizontal planes arranged in box form. Accident attended the first trial of this second airship, which took place over the Bodensee on November 30th, 1905, 'It had been intended to tow the raft, to which it was anchored, further from the shore against the wind. But the water was too low to allow the use of the raft. The balloon was therefore mounted on pontoons, pulled out into the lake, and taken in tow by a motor-boat. It was caught by a strong wind which was blowing from the shore, and driven ahead at such a rate that it overtook the motor-boat. The tow rope was therefore at once cut, but it unexpectedly formed into knots and became entangled with the airship, pulling the front end down into the water. The balloon was then caught by the wind and lifted into the air, when the propellers were set in motion. The front end was at this instant pointing in a downward direction, and consequently it shot into the water, where it was found necessary to open the valves.'[*] [*] Hildebrandt, Airships Past and Present. The damage done was repaired within six weeks, and the second trial was made on January 17th, 1906. The lifting force was too great for the weight, and the dirigible jumped immediately to 1,500 feet. The propellers were started, and the dirigible brought to a lower level, when it was found possible to drive against the wind. The steering arrangements were found too sensitive, and the motors were stopped, when the vessel was carried by the wind until it was over land--it had been intended that the trial should be completed over water. A descent was successfully accomplished and the dirigible was anchored for the night, but a gale caused it so much damage that it had to be broken up. It had achieved a speed of 30 feet per second with the motors developing only 36 horse-power and, gathering from this what speed might have been accomplished with the full 170 horse-power, Zeppelin set about the construction of No. 3, with which a number of successful voyages were made, proving the value of the type for military purposes. No. 4 was the most notable of the early Zeppelins, as much on account of its disastrous end as by reason of any superior merit in comparison with No. 3. The main innovation consisted in attaching a triangular keel to the under side of the envelope, with two gaps beneath which the cars were suspended. Two Daimler Mercedes motors of 110 horse-power each were placed one in each car, and the vessel carried sufficient fuel for a 60-hour cruise with the motors running at full speed. Each motor drove a pair of three-bladed metal propellers rigidly attached to the framework of the envelope and about 15 feet in diameter. There was a vertical rudder at the stern of the envelope and horizontal controlling planes were fixed on the sides of the envelope. The best performances and the end of this dirigible were summarised as follows by Major Squier:-- 'Its best performances were two long trips performed during the summer of 1908. The first, on July 4th, lasted exactly 12 hours, during which time it covered a distance of 235 miles, crossing the mountains to Lucerne and Zurich, and returning to the balloon-house near Friedrichshafen, on Lake Constance. The average speed on this trip was 32 miles per hour. On August 4th, this airship attempted a 24-hour flight, which was one of the requirements made for its acceptance by the Government. It left Friedrichshafen in the morning with the intention of following the Rhine as far as Mainz, and then returning to its starting-point, straight across the country. A stop of 3 hours 30 minutes was made in the afternoon of the first day on the Rhine, to repair the engine. On the return, a second stop was found necessary near Stuttgart, due to difficulties with the motors, and some loss of gas. While anchored to the ground, a storm arose which broke loose the anchorage, and, as the balloon rose in the air, it exploded and took fire (due to causes which have never been actually determined and published) and fell to the ground, where it was completely destroyed. On this journey, which lasted in all 31 hours 15 minutes, the airship was in the air 20 hours 45 minutes, and covered a total distance of 378 miles. 'The patriotism of the German nation was aroused. Subscriptions were immediately started, and in a short space of time a quarter of a million pounds had been raised. A Zeppelin Society was formed to direct the expenditure of this fund. Seventeen thousand pounds has been expended in purchasing land near Friedrichshafen; workshops were erected, and it was announced that within one year the construction of eight airships of the Zeppelin type would be completed. Since the disaster to 'Zeppelin IV.' the Crown Prince of Germany made a trip in 'Zeppelin No. 3,' which had been called back into service, and within a very few days the German Emperor visited Friedrichshafen for the purpose of seeing the airship in flight. He decorated Count Zeppelin with the order of the Black Eagle. German patriotism and enthusiasm has gone further, and the "German Association for an Aerial Fleet" has been organised in sections throughout the country. It announces its intention of building 50 garages (hangars) for housing airships.' By January of 1909, with well over a quarter of a million in hand for the construction of Zeppelin airships, No. 3 was again brought out, probably in order to maintain public enthusiasm in respect of the possible new engine of war. In March of that year No. 3 made a voyage which lasted for 4 hours over and in the vicinity of Lake Constance; it carried 26 passengers for a distance of nearly 150 miles. Before the end of March, Count Zeppelin determined to voyage from Friedrichshafen to Munich, together with the crew of the airship and four military officers. Starting at four in the morning and ascertaining their route from the lights of railway stations and the ringing of bells in the towns passed over, the journey was completed by nine o'clock, but a strong south-west gale prevented the intended landing. The airship was driven before the wind until three o'clock in the afternoon, when it landed safely near Dingolfing; by the next morning the wind had fallen considerably and the airship returned to Munich and landed on the parade ground as originally intended. At about 3.30 in the afternoon, the homeward journey was begun, Friedrichshafen being reached at about 7.30. These trials demonstrated that sufficient progress had been made to justify the construction of Zeppelin airships for use with the German army. No. 3 had been manoeuvred safely if not successfully in half a gale of wind, and henceforth it was known as 'SMS. Zeppelin I.,' at the bidding of the German Emperor, while the construction of 'SMS. Zeppelin II.' was rapidly proceeded with. The fifth construction of Count Zeppelin's was 446 feet in length, 42 1/2 feet in diameter, and contained 530,000 cubic feet of hydrogen gas in 17 separate compartments. Trial flights were made on the 26th May, 1909, and a week later she made a record voyage of 940 miles, the route being from Lake Constance over Ulm, Nuremberg, Leipzig, Bitterfeld, Weimar, Heilbronn, and Stuttgart, descending near Goppingen; the time occupied in the flight was upwards of 38 hours. In landing, the airship collided with a pear-tree, which damaged the bows and tore open two sections of the envelope, but repairs on the spot enabled the return journey to Friedrichshafen to be begun 24 hours later. In spite of the mishap the Zeppelin had once more proved itself as a possible engine of war, and thenceforth Germany pinned its faith to the dirigible, only developing the aeroplane to such an extent as to keep abreast of other nations. By the outbreak of war, nearly 30 Zeppelins had been constructed; considerably more than half of these were destroyed in various ways, but the experiments carried on with each example of the type permitted of improvements being made. The first fatality occurred in September, 1913, when the fourteenth Zeppelin to be constructed, known as Naval Zeppelin L.1, was wrecked in the North Sea by a sudden storm and her crew of thirteen were drowned. About three weeks after this, Naval Zeppelin L.2, the eighteenth in order of building, exploded in mid-air while manoeuvring over Johannisthal. She was carrying a crew of 25, who were all killed. By 1912 the success of the Zeppelin type brought imitators. Chief among them was the Schutte-Lanz, a Mannheim firm, which produced a rigid dirigible with a wooden framework, wire braced. This was not a cylinder like the Zeppelin, but reverted to the cigar shape and contained about the same amount of gas as the Zeppelin type. The Schutte-Lanz was made with two gondolas rigidly attached to the envelope in which the gas bags were placed. The method of construction involved greater weight than was the case with the Zeppelin, but the second of these vessels, built with three gondolas containing engines, and a navigating cabin built into the hull of the airship itself, proved quite successful as a naval scout until wrecked on the islands off the coast of Denmark late in 1914. The last Schutte-Lanz to be constructed was used by the Germans for raiding England, and was eventually brought down in flames at Cowley. V. BRITISH AIRSHIP DESIGN As was the case with the aeroplane, Great Britain left France and Germany to make the running in the early days of airship construction; the balloon section of the Royal Engineers was compelled to confine its energies to work with balloons pure and simple until well after the twentieth century had dawned, and such experiments as were made in England were done by private initiative. As far back as 1900 Doctor Barton built an airship at the Alexandra Palace and voyaged across London in it. Four years later Mr E. T. Willows of Cardiff produced the first successful British dirigible, a semi-rigid 74 feet in length and 18 feet in diameter, engined with a 7 horse-power Peugot twin-cylindered motor. This drove a two-bladed propeller at the stern for propulsion, and also actuated a pair of auxiliary propellers at the front which could be varied in their direction so as to control the right and left movements of the airship. This device was patented and the patent was taken over by the British Government, which by 1908 found Mr Willow's work of sufficient interest to regard it as furnishing data for experiment at the balloon factory at Farnborough. In 1909, Willows steered one of his dirigibles to London from Cardiff in a little less than ten hours, making an average speed of over 14 miles an hour. The best speed accomplished was probably considerably greater than this, for at intervals of a few miles, Willows descended near the earth to ascertain his whereabouts with the help of a megaphone. It must be added that he carried a compass in addition to his megaphone. He set out for Paris in November of 1910, reached the French coast, and landed near Douai. Some damage was sustained in this landing, but, after repair, the trip to Paris was completed. Meanwhile the Government balloon factory at Farnborough began airship construction in 1907; Colonel Capper, R.E., and S. F. Cody were jointly concerned in the production of a semi-rigid. Fifteen thicknesses of goldbeaters' skin--about the most expensive covering obtainable--were used for the envelope, which was 25 feet in diameter. A slight shower of rain in which the airship was caught led to its wreckage, owing to the absorbent quality of the goldbeaters' skin, whereupon Capper and Cody set to work to reproduce the airship and its defects on a larger scale. The first had been named 'Nulli Secundus' and the second was named 'Nulli Secundus II.' Punch very appropriately suggested that the first vessel ought to have been named 'Nulli Primus,' while a possible third should be christened 'Nulli Tertius.' 'Nulli Secundus II.' was fitted with a 100 horse-power engine and had an envelope of 42 feet in diameter, the goldbeaters' skin being covered in fabric and the car being suspended by four bands which encircled the balloon envelope. In October of 1907, 'Nulli Secundus II.' made a trial flight from Farnborough to London and was anchored at the Crystal Palace. The wind sprung up and took the vessel away from its mooring ropes, wrecking it after the one flight. Stagnation followed until early in 1909, when a small airship fitted with two 12 horse-power motors and named the 'Baby' was turned out from the balloon factory. This was almost egg-shaped, the blunt end being forward, and three inflated fins being placed at the tail as control members. A long car with rudder and elevator at its rear-end carried the engines and crew; the 'Baby' made some fairly successful flights and gave a good deal of useful data for the construction of later vessels. Next to this was 'Army Airship 2A 'launched early in 1910 and larger, longer, and narrower in design than the Baby. The engine was an 80 horse-power Green motor which drove two pairs of propellers; small inflated control members were fitted at the stern end of the envelope, which was 154 feet in length. The suspended car was 84 feet long, carrying both engines and crew, and the Willows idea of swivelling propellers for governing the direction was used in this vessel. In June of that year a new, small-type dirigible, the 'Beta,' was produced, driven by a 30 horse-power Green engine with which she flew over 3,000 miles. She was the most successful British dirigible constructed up to that time, and her successor, the 'Gamma,' was built on similar lines. The 'Gamma' was a larger vessel, however, produced in 1912, with flat, controlling fins and rudder at the rear end of the envelope, and with the conventional long car suspended at some distance beneath the gas bag. By this time, the mooring mast, carrying a cap of which the concave side fitted over the convex nose of the airship, had been originated. The cap was swivelled, and, when attached to it, an airship was held nose on to the wind, thus reducing by more than half the dangers attendant on mooring dirigibles in the open. Private subscription under the auspices of the Morning Post got together sufficient funds in 1910 for the purchase of a Lebaudy airship, which was built in France, flown across the Channel, and presented to the Army Airship Fleet. This dirigible was 337 feet long, and was driven by two 135 horse-power Panhard motors, each of which actuated two propellers. The journey from Moisson to Aldershot was completed at a speed of 36 miles an hour, but the airship was damaged while being towed into its shed. On May of the following year, the Lebaudy was brought out for a flight, but, in landing, the guide rope fouled in trees and sheds and brought the airship broadside on to the wind; she was driven into some trees and wrecked to such an exteent that rebuilding was considered an impossibility. A Clement Bayard, bought by the army airship section, became scrap after even less flying than had been accomplished by the Lebaudy. In April of 1910, the Admiralty determined on a naval air service, and set about the production of rigid airships which should be able to compete with Zeppelins as naval scouts. The construction was entrusted to Vickers, Ltd., who set about the task at their Barrow works and built something which, when tested after a year's work, was found incapable of lifting its own weight. This defect was remedied by a series of alterations, and meanwhile the unofficial title of 'Mayfly' was given to the vessel. Taken over by the Admiralty before she had passed any flying tests, the 'Mayfly' was brought out on September 24th, 1911, for a trial trip, being towed out from her shed by a tug. When half out from the shed, the envelope was caught by a light cross-wind, and, in spite of the pull from the tug, the great fabric broke in half, nearly drowning the crew, who had to dive in order to get clear of the wreckage. There was considerable similarity in form, though not in performance, between the Mayfly and the prewar Zeppelin. The former was 510 feet in length, cylindrical in form, with a diameter of 48 feet, and divided into 19 gas-bag compartments. The motive power consisted of two 200 horse-power Wolseley engines. After its failure, the Naval Air Service bought an Astra-Torres airship from France and a Parseval from Germany, both of which proved very useful in the early days of the War, doing patrol work over the Channel before the Blimps came into being. Early in 1915 the 'Blimp' or 'S.S.' type of coastal airship was evolved in response to the demand for a vessel which could be turned out quickly and in quantities. There was urgent demand, voiced by Lord Fisher, for a type of vessel capable of maintaining anti-submarine patrol off the British coasts, and the first S.S. airships were made by combining a gasbag with the most available type of aeroplane fuselage and engine, and fitting steering gear. The 'Blimp' consisted of a B.E. fuselage with engine and geared-down propeller, and seating for pilot and observer, attached to an envelope about 150 feet in length. With a speed of between 35 and 40 miles an hour, the 'Blimp' had a cruising capacity of about ten hours; it was fitted with wireless set, camera, machine-gun, and bombs, and for submarine spotting and patrol work generally it proved invaluable, though owing to low engine power and comparatively small size, its uses were restricted to reasonably fair weather. For work farther out at sea and in all weathers, airships known as the coast patrol type, and more commonly as 'coastals,' were built, and later the 'N.S.' or North Sea type, still larger and more weather-worthy, followed. By the time the last year of the War came, Britain led the world in the design of non-rigid and semi-rigid dirigibles. The 'S.S.' or 'Blimp' had been improved to a speed of 50 miles an hour, carrying a crew of three, and the endurance record for the type was 18 1/2 hours, while one of them had reached a height of 10,000 feet. The North Sea type of non-rigid was capable of travelling over 20 hours at full speed, or forty hours at cruising speed, and the number of non-rigids belonging to the British Navy exceeded that of any other country. It was owing to the incapacity--apparent or real--of the British military or naval designers to produce a satisfactory rigid airship that the 'N.S.' airship was evolved. The first of this type was produced in 1916, and on her trials she was voted an unqualified success, in consequence of which the building of several more was pushed on. The envelope, of 360,000 cubic feet capacity, was made on the Astra-Torres principle of three lobes, giving a trefoil section. The ship carried four fins, to three of which the elevator and rudder flaps were attached; petrol tanks were placed inside the envelope, under which was rigged a long covered-in car, built up of a light steel tubular framework 35 feet in length. The forward portion was covered with duralumin sheeting, an aluminium alloy which, unlike aluminium itself, is not affected by the action of sea air and water, and the remainder with fabric laced to the framework. Windows and port-holes were provided to give light to the crew, and the controls and navigating instruments were placed forward, with the sleeping accommodation aft. The engines were mounted in a power unit structure, separate from the car and connected by wooden gang ways supported by wire cables. A complete electrical installation of two dynamos and batteries for lights, signalling lamps, wireless, telephones, etc., was carried, and the motive power consisted of either two 250 horse-power Rolls-Royce engines or two 240 horse-power Fiat engines. The principal dimensions of this type are length 262 feet, horizontal diameter 56 feet 9 inches, vertical diameter 69 feet 3 inches. The gross lift is 24,300 lbs. and the disposable lift without crew, petrol, oil, and ballast 8,500 lbs. The normal crew carried for patrol work was ten officers and men. This type holds the record of 101 hours continuous flight on patrol duty. In the matter of rigid design it was not until 1913 that the British Admiralty got over the fact that the 'Mayfly' would not, and decided on a further attempt at the construction of a rigid dirigible. The contract for this was signed in March of 1914; work was suspended in the following February and begun again in July, 1915, but it was not until January of 1917 that the ship was finished, while her trials were not completed until March of 1917, when she was taken over by the Admiralty. The details of the construction and trial of this vessel, known as 'No. 9,' go to show that she did not quite fill the contract requirements in respect of disposable lift until a number of alterations had been made. The contract specified that a speed of at least 45 miles per hour was to be attained at full engine power, while a minimum disposable lift of 5 tons was to be available for movable weights, and the airship was to be capable of rising to a height of 2,000 feet. Driven by four Wolseley Maybach engines of 180 horse-power each, the lift of the vessel was not sufficient, so it was decided to remove the two engines in the after car and replace them by a single engine of 250 horsepower. With this the vessel reached the contract speed of 45 miles per hour with a cruising radius of 18 hours, equivalent to 800 miles when the engines were running at full speed. The vessel served admirably as a training airship, for, by the time she was completed, the No. 23 class of rigid airship had come to being, and thus No. 9 was already out of date. Three of the 23 class were completed by the end of 1917; it was stipulated that they should be built with a speed of at least 55 miles per hour, a minimum disposable lift of 8 tons, and a capability of rising at an average rate of not less than 1,000 feet per minute to a height of 3,000 feet. The motive power consisted of four 250 horse-power Rolls-Royce engines, one in each of the forward and after cars and two in a centre car. Four-bladed propellers were used throughout the ship. A 23X type followed on the 23 class, but by the time two ships had been completed, this was practically obsolete. The No. 31 class followed the 23X; it was built on Schutte-Lanz lines, 615 feet in length, 66 feet diameter, and a million and a half cubic feet capacity. The hull was similar to the later types of Zeppelin in shape, with a tapering stern and a bluff, rounded bow. Five cars each carrying a 250 horse-power Rolls-Royce engine, driving a single fixed propeller, were fitted, and on her trials R.31 performed well, especially in the matter of speed. But the experiment of constructing in wood in the Schutte-Lanz way adopted with this vessel resulted in failure eventually, and the type was abandoned. Meanwhile, Germany had been pushing forward Zeppelin design and straining every nerve in the improvement of rigid dirigible construction, until L.33 was evolved; she was generally known as a super-Zeppelin, and on September 24th, 1916, six weeks after her launching, she was damaged by gun-fire in a raid over London, being eventually compelled to come to earth at Little Wigborough in Essex. The crew gave themselves up after having set fire to the ship, and though the fabric was totally destroyed, the structure of the hull remained intact, so that just as Germany was able to evolve the Gotha bomber from the Handley-Page delivered at Lille, British naval constructors were able to evolve the R.33 type of airship from the Zeppelin framework delivered at Little Wigborough. Two vessels, R.33 and R.34, were laid down for completion; three others were also put down for construction, but, while R.33 and R.34 were built almost entirely from the data gathered from the wrecked L.33, the three later vessels embody more modern design, including a number of improvements, and more especially greater disposable lift. It has been commented that while the British authorities were building R.33 and R.34, Germany constructed 30 Zeppelins on 4 slips, for which reason it may be reckoned a matter for congratulation that the rigid airship did not decide the fate of the War. The following particulars of construction of the R.33 and R.34 types are as given by Major Whale in his survey of British Airships:-- 'In all its main features the hull structure of R.33 and R.34 follows the design of the wrecked German Zeppelin airship L.33. 'The hull follows more nearly a true stream-line shape than in the previous ships constructed of duralumin, in which a greater proportion of the greater length was parallel-sided. The Germans adopted this new shape from the Schutte-Lanz design and have not departed from this practice. This consists of a short, parallel body with a long, rounded bow and a long tapering stem culminating in a point. The overall length of the ship is 643 feet with a diameter of 79 feet and an extreme height of 92 feet. 'The type of girders in this class has been much altered from those in previous ships. The hull is fitted with an internal triangular keel throughout practically the entire length. This forms the main corridor of the ship, and is fitted with a footway down the centre for its entire length. It contains water ballast and petrol tanks, bomb storage and crew accommodation, and the various control wires, petrol pipes, and electric leads are carried along the lower part. 'Throughout this internal corridor runs a bridge girder, from which the petrol and water ballast tanks are supported. These tanks are so arranged that they can be dropped clear of the ship. Amidships is the cabin space with sufficient room for a crew of twenty-five. Hammocks can be swung from the bridge girder before mentioned. 'In accordance with the latest Zeppelin practice, monoplane rudders and elevators are fitted to the horizontal and vertical fins. 'The ship is supported in the air by nineteen gas bags, which give a total capacity of approximately two million cubic feet of gas. The gross lift works out at approximately 59 1/2 tons, of which the total fixed weight is 33 tons, giving a disposable lift of 26 1/2 tons. 'The arrangement of cars is as follows: At the forward end the control car is slung, which contains all navigating instruments and the various controls. Adjoining this is the wireless cabin, which is also fitted for wireless telephony. Immediately aft of this is the forward power car containing one engine, which gives the appearance that the whole is one large car. 'Amidships are two wing cars, each containing a single engine. These are small and just accommodate the engines with sufficient room for mechanics to attend to them. Further aft is another larger car which contains an auxiliary control position and two engines. 'It will thus be seen that five engines are installed in the ship; these are all of the same type and horsepower, namely, 250 horse-power Sunbeam. R.33 was constructed by Messrs Armstrong, Whitworth, Ltd.; while her sister ship R.34 was built by Messrs Beardmore on the Clyde.' Of the two vessels, R.34 appeared rather more airworthy than her sister ship; the lift of the ship justified the carrying of a greater quantity of fuel than had been provided for, and, as she was considered suitable for making a Transatlantic crossing, extra petrol tanks were fitted in the hull and a new type of outer cover was fitted with a view to her making the Atlantic crossing. She made a 21-hour cruise over the North of England and the South of Scotland at the end of May, 1919, and subsequently went for a longer cruise over Denmark, the Baltic, and the north coast of Germany, remaining in the air for 56 hours in spite of very bad weather conditions. Finally, July 2nd was selected as the starting date for the cross Atlantic flight; the vessel was commanded by Major G. H. Scott, A.F.C., with Captain G. S. Greenland as first officer, Second-Lieut. H. F. Luck as second officer, and Lieut. J. D. Shotter as engineer officer. There were also on board Brig.-Gen. E. P. Maitland, representing the Air Ministry, Major J. E. M. Pritchard, representing the Admiralty, and Lieut.-Col. W. H. Hemsley of the Army Aviation Department. In addition to eight tons of petrol, R.34 carried a total number of 30 persons from East Fortune to Long Island, N.Y. There being no shed in America capable of accommodating the airship, she had to be moored in the open for refilling with fuel and gas, and to make the return journey almost immediately. Brig.-Gen. Maitland's account of the flight, in itself a record as interesting as valuable, divides the outward journey into two main stages, the first from East Fortune to Trinity Bay, Newfoundland, a distance of 2,050 sea miles, and the second and more difficult stage to Mineola Field, Long Island, 1,080 sea miles. An easy journey was experienced until Newfoundland was reached, but then storms and electrical disturbances rendered it necessary to alter the course, in consequence of which petrol began to run short. Head winds rendered the shortage still more acute, and on Saturday, July 5th, a wireless signal was sent out asking for destroyers to stand by to tow. However, after an anxious night, R.33 landed safely at Mineola Field at 9.55 a.m. on July 6th, having accomplished the journey in 108 hours 12 minutes. She remained at Mineola until midnight of July 9th, when, although it had been intended that a start should be made by daylight for the benefit of New York spectators, an approaching storm caused preparations to be advanced for immediate departure. She set out at 5.57 a.m. by British summer time, and flew over New York in the full glare of hundreds of searchlights before heading out over the Atlantic. A following wind assisted the return voyage, and on July 13th, at 7.57 a.m., R.34 anchored at Pulham, Norfolk, having made the return journey in 75 hours 3 minutes, and proved the suitability of the dirigible for Transatlantic commercial work. R.80, launched on July 19th, 1920, afforded further proof, if this were needed. It is to be noted that nearly all the disasters to airships have been caused by launching and landing--the type is safe enough in the air, under its own power, but its bulk renders it unwieldy for ground handling. The German system of handling Zeppelins in and out of their sheds is, so far, the best devised: this consists of heavy trucks running on rails through the sheds and out at either end; on descending, the trucks are run out, and the airship is securely attached to them outside the shed; the trucks are then run back into the shed, taking the airship with them, and preventing any possibility of the wind driving the envelope against the side of the shed before it is safely housed; the reverse process is adopted in launching, which is thus rendered as simple as it is safe. VI. THE AIRSHIP COMMERCIALLY Prior to the war period, between the years 1910 and 1914, a German undertaking called the Deutsche Luftfahrt Actien Gesellschaft conducted a commercial Zeppelin service in which four airships known as the Sachsan, Hansa, Victoria Louise, and Schwaben were used. During the four years of its work, the company carried over 17,000 passengers, and over 100,000 miles were flown without incurring one fatality and with only minor and unavoidable accidents to the vessels composing the service. Although a number of English notabilities made voyages in these airships, the success of this only experiment in commercial aerostation seems to have been forgotten since the war. There was beyond doubt a military aim in this apparently peaceful use of Zeppelin airships; it is past question now that all Germany's mechanical development in respect of land sea, and air transport in the years immediately preceding the war, was accomplished with the ulterior aim of military conquest, but, at the same time, the running of this service afforded proof of the possibility of establishing a dirigible service for peaceful ends, and afforded proof too, of the value of the dirigible as a vessel of purely commercial utility. In considering the possibility of a commercial dirigible service, it is necessary always to bear in mind the disadvantages of first cost and upkeep as compared with the aeroplane. The building of a modern rigid is an exceedingly costly undertaking, and the provision of an efficient supply of hydrogen gas to keep its compartments filled is a very large item in upkeep of which the heavier-than-air machine goes free. Yet the future of commercial aeronautics so far would seem to lie with the dirigible where very long voyages are in question. No matter how the aeroplane may be improved, the possibility of engine failure always remains as a danger for work over water. In seaplane or flying boat form, the danger is still present in a rough sea, though in the American Transatlantic flight, N.C.3, taxi-ing 300 miles to the Azores after having fallen to the water, proved that this danger is not so acute as is generally assumed. Yet the multiple-engined rigid, as R.34 showed on her return voyage, may have part of her power plant put out of action altogether and still complete her voyage very successfully, which, in the case of mail carrying and services run strictly to time, gives her an enormous advantage over the heavier-than-air machine. 'For commercial purposes,' General Sykes has remarked, 'the airship is eminently adapted for long distance journeys involving non-stop flights. It has this inherent advantage over the aeroplane, that while there appears to be a limit to the range of the aeroplane as at present constructed, there is practically no limit whatever to that of the airship, as this can be overcome by merely increasing the size. It thus appears that for such journeys as crossing the Atlantic, or crossing the Pacific from the west coast of America to Australia or Japan, the airship will be peculiarly suitable. It having been conceded that the scope of the airship is long distance travel, the only type which need be considered for this purpose is the rigid. The rigid airship is still in an embryonic state, but sufficient has already been accomplished in this country, and more particularly in Germany, to show that with increased capacity there is no reason why, within a few years' time, airships should not be built capable of completing the circuit of the globe and of conveying sufficient passengers and merchandise to render such an undertaking a paying proposition.' The British R.38 class, embodying the latest improvements in airship design outside Germany, gives a gross lift per airship of 85 tons and a net lift of about 45 tons. The capacity of the gas bags is about two and three-quarter million cubic feet, and, travelling at the rate of 45 miles per hour, the cruising range of the vessel is estimated at 8.8 days. Six engines, each of 350 horse-power, admit of an extreme speed of 70 miles per hour if necessary. The last word in German design is exemplified in the rigids L.70 and L.71, together with the commercial airship 'Bodensee.' Previous to the construction of these, the L.65 type is noteworthy as being the first Zeppelin in which direct drive of the propeller was introduced, together with an improved and lighter type of car. L.70 built in 1918 and destroyed by the British naval forces, had a speed of about 75 miles per hour; L.71 had a maximum speed of 72 miles per hour, a gas bag capacity of 2,420,000 cubic feet, and a length of 743 feet, while the total lift was 73 tons. Progress in design is best shown by the progress in useful load; in the L.70 and L.71 class, this has been increased to 58.3 per cent, while in the Bodensee it was ever higher. As was shown in R.34's American flight, the main problem in connection with the commercial use of dirigibles is that of mooring in the open. The nearest to a solution of this problem, so far, consists in the mast carrying a swivelling cap; this has been tried in the British service with a non-rigid airship, which was attached to a mast in open country in a gale of 52 miles an hour without the slightest damage to the airship. In its commercial form, the mast would probably take the form of a tower, at the top of which the cap would revolve so that the airship should always face the wind, the tower being used for embarkation and disembarkation of passengers and the provision of fuel and gas. Such a system would render sheds unnecessary except in case of repairs, and would enormously decrease the establishment charges of any commercial airship. All this, however, is hypothetical. Remains the airship of to-day, developed far beyond the promise of five years ago, capable, as has been proved by its achievements both in Britain and in Germany, of undertaking practically any given voyage with success. VII. KITE BALLOONS As far back as the period of the Napoleonic wars, the balloon was given a place in warfare, but up to the Franco-Prussian Prussian War of 1870-71 its use was intermittent. The Federal forces made use of balloons to a small extent in the American Civil War; they came to great prominence in the siege of Paris, carrying out upwards of three million letters and sundry carrier pigeons which took back messages into the besieged city. Meanwhile, as captive balloons, the German and other armies used them for observation and the direction of artillery fire. In this work the ordinary spherical balloon was at a grave disadvantage; if a gust of wind struck it, the balloon was blown downward and down wind, generally twirling in the air and upsetting any calculations and estimates that might be made by the observers, while in a wind of 25 miles an hour it could not rise at all. The rotatory movement caused by wind was stopped by an experimenter in the Russo-Japanese war, who fixed to the captive observation balloons a fin which acted as a rudder. This did not stop the balloon from being blown downward and away from its mooring station, but this tendency was overcome by a modification designed in Germany by the Parseval-Siegsfield Company, which originated what has since become familiar as the 'Sausage' or kite balloon. This is so arranged that the forward end is tilted up into the wind, and the underside of the gas bag, acting as a plane, gives the balloon a lifting tendency in a wind, thus counteracting the tendency of the wind to blow it downward and away from its mooring station. Smaller bags are fitted at the lower and rear end of the balloon with openings that face into the wind; these are thus kept inflated, and they serve the purpose of a rudder, keeping the kite balloon steady in the air. Various types of kite balloon have been introduced; the original German Parseval-Siegsfield had a single air bag at the stern end, which was modified to two, three, or more lobes in later varieties, while an American experimental design attempted to do away with the attached lobes altogether by stringing out a series of small air bags, kite fashion, in rear of the main envelope. At the beginning of the War, Germany alone had kite balloons, for the authorities of the Allied armies con-sidered that the bulk of such a vessel rendered it too conspicuous a mark to permit of its being serviceable. The Belgian arm alone possessed two which, on being put into service, were found extremely useful. The French followed by constructing kite balloons at Chalais Meudon, and then, after some months of hostilities and with the example of the Royal Naval Air Service to encourage them, the British military authorities finally took up the construction and use of kite balloons for artillery-spotting and general observation purposes. Although many were brought down by gun-fire, their uses far outweighed their disadvantages, and toward the end of the War, hardly a mile of front was without its 'Sausage.' For naval work, kite balloons were carried in a specially constructed hold in the forepart of certain vessels; when required for use, the covering of the hold was removed, the kite balloon inflated and released to the required height by means of winches as in the case of the land work. The perfecting of the 'Coastal' and N.S. types of airship, together with the extension of wireless telephony between airship and cruiser or other warship, in all probability will render the use of the kite balloon unnecessary in connection with naval scouting. But, during the War, neither wireless telephony nor naval airships had developed sufficiently to render the Navy independent of any means that might come to hand, and the fitting of kite balloons in this fashion filled a need of the times. A necessary accessory of the kite balloon is the parachute, which has a long history. Da Vinci and Veranzio appear to have been the first exponents, the first in the theory and the latter in the practice of parachuting. Montgolfier experimented at Annonay before he constructed his first hot air-balloon, and in 1783 a certain Lenormand dropped from a tree in a parachute. Blanchard the balloonist made a spectacle of parachuting, and made it a financial success; Cocking, in 1836, attempted to use an inverted form of parachute; taken up to a height of 3,000 feet, he was cut adrift, when the framework of the parachute collapsed and Cocking was killed. The rate of fall is slow in parachuting to the ground. Frau Poitevin, making a descent from a height of 6,000 feet, took 45 minutes to reach the ground, and, when she alighted, her husband, who had taken her up, had nearly got his balloon packed up. Robertson, another parachutist is said to have descended from a height of 10,000 feet in 35 minutes, or at a rate of nearly 5 feet per second. During the War Brigadier-General Maitland made a parachute descent from a height of 10,000 feet, the time taken being about 20 minutes. The parachute was developed considerably during the War period, the main requirement, that of certainty in opening, being considerably developed. Considered a necessary accessory for kite balloons, the parachute was also partially adopted for use with aeroplanes in the later War period, when it was contended that if a machine were shot down in flames, its occupants would be given a far better chance of escape if they had parachutes. Various trials were made to demonstrate the extreme efficiency of the parachute in modern form, one of them being a descent from the upper ways of the Tower Bridge to the waters of the Thames, in which short distance the 'Guardian Angel' type of parachute opened and cushioned the descent for its user. For dirigibles, balloons, and kite balloons the parachute is an essential. It would seem to be equally essential in the case of heavier-than-air machines, but this point is still debated. Certainly it affords the occupant of a falling aeroplane a chance, no matter how slender, of reaching the ground in safety, and, for that reason, it would seem to have a place in aviation as well as in aerostation. PART IV. ENGINE DEVELOPMENT I. THE VERTICAL TYPE The balloon was but a year old when the brothers Robert, in 1784 attempted propulsion of an aerial vehicle by hand-power, and succeeded, to a certain extent, since they were able to make progress when there was only a slight wind to counteract their work. But, as may be easily understood, the manual power provided gave but a very slow speed, and in any wind it all the would-be airship became an uncontrolled balloon. Henson and Stringfellow, with their light steam engines, were first to attempt conquest of the problem of mechanical propulsion in the air; their work in this direction is so fully linked up with their constructed models that it has been outlined in the section dealing with the development of the aeroplane. But, very shortly after these two began, there came into the field a Monsieur Henri Giffard, who first achieved success in the propulsion by mechanical means of dirigible balloons, for his was the first airship to fly against the wind. He employed a small steam-engine developing about 3 horse-power and weighing 350 lbs. with boiler, fitting the whole in a car suspended from the gas-bag of his dirigible. The propeller which this engine worked was 11 feet in diameter, and the inventor, who made several flights, obtained a speed of 6 miles an hour against a slight wind. The power was not sufficient to render the invention practicable, as the dirigible could only be used in calm weather, but Giffard was sufficiently encouraged by his results to get out plans for immense dirigibles, which through lack of funds he was unable to construct. When, later, his invention of the steam-injector gave him the means he desired, he became blind, and in 1882 died, having built but the one famous dirigible. This appears to have been the only instance of a steam engine being fitted to a dirigible; the inherent disadvantage of this form of motive power is that a boiler to generate the steam must be carried, and this, together with the weight of water and fuel, renders the steam engine uneconomical in relation to the lift either of plane or gas-bag. Again, even if the weight could be brought down to a reasonable amount, the attention required by steam plant renders it undesirable as a motive power for aircraft when compared with the internal combustion engine. Maxim, in Artificial and Natural Flight, details the engine which he constructed for use with his giant experimental flying machine, and his description is worthy of reproduction since it is that of the only steam engine besides Giffard's, and apart from those used for the propulsion of models, designed for driving an aeroplane. 'In 1889,' Maxim says, 'I had my attention drawn to some very thin, strong, and comparatively cheap tubes which were being made in France, and it was only after I had seen these tubes that I seriously considered the question of making a flying machine. I obtained a large quantity of them and found that they were very light, that they would stand enormously high pressures, and generate a very large quantity of steam. Upon going into a mathematical calculation of the whole subject, I found that it would be possible to make a machine on the aeroplane system, driven by a steam engine, which would be sufficiently strong to lift itself into the air. I first made drawings of a steam engine, and a pair of these engines was afterwards made. These engines are constructed, for the most part, of a very high grade of cast steel, the cylinders being only 3/32 of an inch thick, the crank shafts hollow, and every part as strong and light as possible. They are compound, each having a high-pressure piston with an area of 20 square inches, a low-pressure piston of 50.26 square inches, and a common stroke of 1 foot. When first finished they were found to weigh 300 lbs. each; but after putting on the oil cups, felting, painting, and making some slight alterations, the weight was brought up to 320 lbs. each, or a total of 640 lbs. for the two engines, which have since developed 362 horsepower with a steam pressure of 320 lbs. per square inch.' The result is remarkable, being less than 2 lbs. weight per horse-power, especially when one considers the state of development to which the steam engine had attained at the time these experiments were made. The fining down of the internal combustion engine, which has done so much to solve the problems of power in relation to weight for use with aircraft, had not then been begun, and Maxim had nothing to guide him, so far as work on the part of his predecessors was concerned, save the experimental engines of Stringfellow, which, being constructed on so small a scale in comparison with his own, afforded little guidance. Concerning the factor of power, he says: 'When first designing this engine, I did not know how much power I might require from it. I thought that in some cases it might be necessary to allow the high-pressure steam to enter the low-pressure cylinder direct, but as this would involve a considerable loss, I constructed a species of injector. This injector may be so adjusted that when the steam in the boiler rises above a certain predetermined point, say 300 lbs., to the square inch, it opens a valve and escapes past the high-pressure cylinder instead of blowing off at the safety valve. In escaping through this valve, a fall of about 200 lbs. pressure per square inch is made to do work on the surrounding steam and drive it forward in the pipe, producing a pressure on the low-pressure piston considerably higher than the back-pressure on the high-pressure piston. In this way a portion of the work which would otherwise be lost is utilised, and it is possible, with an unlimited supply of steam, to cause the engines to develop an enormous amount of power.' With regard to boilers, Maxim writes, 'The first boiler which I made was constructed something on the Herreshof principle, but instead of having one simple pipe in one very long coil, I used a series of very small and light pipes, connected in such a manner that there was a rapid circulation through the whole--the tubes increasing in size and number as the steam was generated. I intended that there should be a pressure of about 100 lbs. more on the feed water end of the series than on the steam end, and I believed that this difference in pressure would be sufficient to ensure direct and positive circulation through every tube in the series. The first boiler was exceedingly light, but the workmanship, as far as putting the tubes together was concerned, was very bad, and it was found impossible to so adjust the supply of water as to make dry steam without overheating and destroying the tubes. 'Before making another boiler I obtained a quantity of copper tubes, about 8 feet long, 3/8 inch external diameter, and 1/50 of an inch thick. I subjected about 100 of these tubes to an internal pressure of 1 ton per square inch of cold kerosene oil, and as none of them leaked I did not test any more, but commenced my experiments by placing some of them in a white-hot petroleum fire. I found that I could evaporate as much as 26 1/2 lbs. of water per square foot of heating surface per hour, and that with a forced circulation, although the quantity of water passing was very small but positive, there was no danger of overheating. I conducted many experiments with a pressure of over 400 lbs. per square inch, but none of the tubes failed. I then mounted a single tube in a white-hot furnace, also with a water circulation, and found that it only burst under steam at a pressure of 1,650 lbs. per square inch. A large boiler, having about 800 square feet of heating surface, including the feed-water heater, was then constructed. This boiler is about 4 1/2 feet wide at the bottom, 8 feet long and 6 feet high. It weighs, with the casing, the dome, and the smoke stack and connections, a little less than 1,000 lbs. The water first passes through a system of small tubes--1/4 inch in diameter and 1/60 inch thick--which were placed at the top of the boiler and immediately over the large tubes.... This feed-water heater is found to be very effective. It utilises the heat of the products of combustion after they have passed through the boiler proper and greatly reduces their temperature, while the feed-water enters the boiler at a temperature of about 250 F. A forced circulation is maintained in the boiler, the feed-water entering through a spring valve, the spring valve being adjusted in such a manner that the pressure on the water is always 30 lbs. per square inch in excess of the boiler pressure. This fall of 30 lbs. in pressure acts upon the surrounding hot water which has already passed through the tubes, and drives it down through a vertical outside tube, thus ensuring a positive and rapid circulation through all the tubes. This apparatus is found to act extremely well.' Thus Maxim, who with this engine as power for his large aeroplane achieved free flight once, as a matter of experiment, though for what distance or time the machine was actually off the ground is matter for debate, since it only got free by tearing up the rails which were to have held it down in the experiment. Here, however, was a steam engine which was practicable for use in the air, obviously, and only the rapid success of the internal combustion engine prevented the steam-producing type from being developed toward perfection. The first designers of internal combustion engines, knowing nothing of the petrol of these days, constructed their examples with a view to using gas as fuel. As far back as 1872 Herr Paul Haenlein obtained a speed of about 10 miles an hour with a balloon propelled by an internal combustion engine, of which the fuel was gas obtained from the balloon itself. The engine in this case was of the Lenoir type, developing some 6 horse-power, and, obviously, Haenlein's flights were purely experimental and of short duration, since he used the gas that sustained him and decreased the lifting power of his balloon with every stroke of the piston of his engine. No further progress appears to have been made with the gas-consuming type of internal combustion engine for work with aircraft; this type has the disadvantage of requiring either a gas-producer or a large storage capacity for the gas, either of which makes the total weight of the power plant much greater than that of a petrol engine. The latter type also requires less attention when working, and the fuel is more convenient both for carrying and in the matter of carburation. The first airship propelled by the present-day type of internal combustion engine was constructed by Baumgarten and Wolfert in 1879 at Leipzig, the engine being made by Daimler with a view to working on benzine--petrol as a fuel had not then come to its own. The construction of this engine is interesting since it was one of the first of Daimler's make, and it was the development brought about by the experimental series of which this engine was one that led to the success of the motor-car in very few years, incidentally leading to that fining down of the internal combustion engine which has facilitated the development of the aeroplane with such remarkable rapidity. Owing to the faulty construction of the airship no useful information was obtained from Daimler's pioneer installation, as the vessel got out of control immediately after it was first launched for flight, and was wrecked. Subsequent attempts at mechanically-propelled flight by Wolfert ended, in 1897, in the balloon being set on fire by an explosion of benzine vapour, resulting in the death of both the aeronauts. Daimler, from 1882 onward, devoted his attention to the perfecting of the small, high-speed petrol engine for motor-car work, and owing to his efforts, together with those of other pioneer engine-builders, the motorcar was made a success. In a few years the weight of this type of engine was reduced from near on a hundred pounds per horse-power to less than a tenth of that weight, but considerable further improvement had to be made before an engine suitable for use with aircraft was evolved. The increase in power of the engines fitted to airships has made steady progress from the outset; Haenlein's engine developed about 6 horse-power; the Santos-Dumont airship of 1898 was propelled by a motor of 4 horse-power; in 1902 the Lebaudy airship was fitted with an engine of 40 horse-power, while, in 1910, the Lebaudy brothers fitted an engine of nearly 300 horsepower to the airship they were then constructing--1,400 horse-power was common in the airships of the War period, and the later British rigids developed yet more. Before passing on to consideration of the petrol-driven type of engine, it is necessary to accord brief mention to the dirigible constructed in 1884 by Gaston and Albert Tissandier, who at Grenelle, France, achieved a directed flight in a wind of 8 miles an hour, obtaining their power for the propeller from 1 1/3 horse-power Siemens electric motor, which weighed 121 lbs. and took its current from a bichromate battery weighing 496 lbs. A two-bladed propeller, 9 feet in diameter, was used, and the horse-power output was estimated to have run up to 1 1/2 as the dirigible successfully described a semicircle in a wind of 8 miles an hour, subsequently making headway transversely to a wind of 7 miles an hour. The dirigible with which this motor was used was of the conventional pointed-end type, with a length of 92 feet, diameter of 30 feet, and capacity of 37,440 cubic feet of gas. Commandant Renard, of the French army balloon corps, followed up Tissandier's attempt in the next year--1885--making a trip from Chalais-Meudon to Paris and returning to the point of departure quite successfully. In this case the motive power was derived from an electric plant of the type used by the Tissandiers, weighing altogether 1,174 lbs., and developing 9 horsepower. A speed of 14 miles an hour was attained with this dirigible, which had a length of 165 feet, diameter of 27 feet, and capacity of 65,836 cubic feet of gas. Reverting to the petrol-fed type again, it is to be noted that Santos-Dumont was practically the first to develop the use of the ordinary automobile engine for air work--his work is of such importance that it has been considered best to treat of it as one whole, and details of the power plants are included in the account of his experiments. Coming to the Lebaudy brothers and their work, their engine of 1902 was a 40 horse-power Daimler, four-cylindered; it was virtually a large edition of the Daimler car engine, the arrangement of the various details being on the lines usually adopted for the standard Daimler type of that period. The cylinders were fully water-jacketed, and no special attempt toward securing lightness for air work appears to have been made. The fining down of detail that brought weight to such limits as would fit the engine for work with heavier-than-air craft appears to have waited for the brothers Wright. Toward the end of 1903 they fitted to their first practicable flying machine the engine which made the historic first aeroplane flight; this engine developed 30 horse-power, and weighed only about 7 lbs. per horse-power developed, its design and workmanship being far ahead of any previous design in this respect, with the exception of the remarkable engine, designed by Manly, installed in Langley's ill-fated aeroplane--or 'aerodrome,' as he preferred to call it--tried in 1903. The light weight of the Wright brothers' engine did not necessitate a high number of revolutions per minute to get the requisite power; the speed was only 1,300 revolutions per minute, which, with a piston stroke of 3.94 inches, was quite moderate. Four cylinders were used, the cylinder diameter being 4.42 inches; the engine was of the vertical type, arranged to drive two propellers at a rate of about 350 revolutions per minute, gearing being accomplished by means of chain drive from crank-shaft end to propeller spindle. The methods adopted by the Wrights for obtaining a light-weight engine were of considerable interest, in view of the fact that the honour of first achieving flight by means of the driven plane belongs to them--unless Ader actually flew as he claimed. The cylinders of this first Wright engine were separate castings of steel, and only the barrels were jacketed, this being done by fixing loose, thin aluminium covers round the outside of each cylinder. The combustion head and valve pockets were cast together with the cylinder barrel, and were not water cooled. The inlet valves were of the automatic type, arranged on the tops of the cylinders, while the exhaust valves were also overhead, operated by rockers and push-rods. The pistons and piston rings were of the ordinary type, made of cast-iron, and the connecting rods were circular in form, with a hole drilled down the middle of each to reduce the weight. Necessity for increasing power and ever lighter weight in relation to the power produced has led to the evolution of a number of different designs of internal combustion engines. It was quickly realised that increasing the number of cylinders on an engine was a better way of getting more power than that of increasing the cylinder diameter, as the greater number of cylinders gives better torque-even turning effect--as well as keeping down the weight--this latter because the bigger cylinders must be more stoutly constructed than the small sizes; this fact has led to the construction of engines having as many as eighteen cylinders, arranged in three parallel rows in order to keep the length of crankshaft within reasonable limits. The aero engine of to-day may, roughly, be divided into four classes: these are the V type, in which two rows of cylinders are set parallel at a certain angle to each other; the radial type, which consists of cylinders arranged radially and remaining stationary while the crankshaft revolves; the rotary, where the cylinders are disposed round a common centre and revolve round a stationary shaft, and the vertical type, of four or six cylinders--seldom more than this--arranged in one row. A modification of the V type is the eighteen-cylindered engine--the Sunbeam is one of the best examples--in which three rows of cylinders are set parallel to each other, working on a common crankshaft. The development these four types started with that of the vertical--the simplest of all; the V, radial, and rotary types came after the vertical, in the order given. The evolution of the motor-car led to the adoption of the vertical type of internal combustion engine in preference to any other, and it followed naturally that vertical engines should be first used for aeroplane propulsion, as by taking an engine that had been developed to some extent, and adapting it to its new work, the problem of mechanical flight was rendered easier than if a totally new type had had to be evolved. It was quickly realised--by the Wrights, in fact-that the minimum of weight per horse-power was the prime requirement for the successful development of heavier-than-air machines, and at the same time it was equally apparent that the utmost reliability had to be obtained from the engine, while a third requisite was economy, in order to reduce the weight of petrol necessary for flight. Daimler, working steadily toward the improvement of the internal combustion engine, had made considerable progress by the end of last century. His two-cylinder engine of 1897 was approaching to the present-day type, except as regards the method of ignition; the cylinders had 3.55 inch diameter, with a 4.75 inch piston stroke, and the engine was rated at 4.5 brake horse-power, though it probably developed more than this in actual running at its rated speed of 800 revolutions per minute. Power was limited by the inlet and exhaust passages, which, compared with present-day practice, were very small. The heavy castings of which the engine was made up are accounted for by the necessity for considering foundry practice of the time, for in 1897 castings were far below the present-day standard. The crank-case of this two-cylinder vertical Daimler engine was the only part made of aluminium, and even with this no attempt was made to attain lightness, for a circular flange was cast at the bottom to form a stand for the engine during machining and erection. The general design can be followed from the sectional views, and these will show, too, that ignition was by means of a hot tube on the cylinder head, which had to be heated with a blow-lamp before starting the engine. With all its well known and hated troubles, at that time tube ignition had an advantage over the magneto, and the coil and accumulator system, in reliability; sparking plugs, too, were not so reliable then as they are now. Daimler fitted a very simple type of carburettor to this engine, consisting only of a float with a single jet placed in the air passage. It may be said that this twin-cylindered vertical was the first of the series from which has been evolved the Mercedes-Daimler car and airship engines, built in sizes up to and even beyond 240 horse-power. In 1901 the development of the petrol engine was still so slight that it did not admit of the construction, by any European maker, of an engine weighing less than 12 lbs. per horse-power. Manly, working at the instance of Professor Langley, produced a five-cylindered radial type engine, in which both the design and workmanship showed a remarkable advance in construction. At 950 revolutions per minute it developed 52.4 horse-power, weighing only 2.4 pounds per horse-power; it was a very remarkable achievement in engine design, considering the power developed in relation to the total weight, and it was, too, an interruption in the development of the vertical type which showed that there were other equally great possibilities in design. In England, the first vertical aero-engine of note was that designed by Green, the cylinder dimensions being 4.15 inch diameter by 4.75 stroke--a fairly complete idea of this engine can be obtained from the accompanying diagrams. At a speed of 1,160 revolutions per minute it developed 35 brake horse-power, and by accelerating up to 1,220 revolutions per minute a maximum of 40 brake horse-power could be obtained--the first-mentioned was the rated working speed of the engine for continuous runs. A flywheel, weighing 23.5 lbs., was fitted to the engine, and this, together with the ignition system, brought the weight up to 188 lbs., giving 5.4 lbs. per horse-power. In comparison with the engine fitted to the Wrights' aeroplane a greater power was obtained from approximately the same cylinder volume, and an appreciable saving in weight had also been effected. The illustration shows the arrangement of the vertical valves at the top of the cylinder and the overhead cam shaft, while the position of the carburettor and inlet pipes can be also seen. The water jackets were formed by thin copper casings, each cylinder being separate and having its independent jacket rigidly fastened to the cylinder at the top only, thus allowing for free expansion of the casing; the joint at the bottom end was formed by sliding the jacket over a rubber ring. Each cylinder was bolted to the crank-case and set out of line with the crankshaft, so that the crank has passed over the upper dead centre by the time that the piston is at the top of its stroke when receiving the full force of fuel explosion. The advantage of this desaxe setting is that the pressure in the cylinder acts on the crank-pin with a more effective leverage during that part of the stroke when that pressure is highest, and in addition the side pressure of the piston on the cylinder wall, due to the thrust of the connecting rod, is reduced. Possibly the charging of the cylinder is also more complete by this arrangement, owing to the slower movement of the piston at the bottom of its stroke allowing time for an increased charge of mixture to enter the cylinder. A 60 horse-power engine was also made, having four vertical cylinders, each with a diameter of 5.5 inches and stroke of 5.75 inches, developing its rated power at 1,100 revolutions per minute. By accelerating up to 1,200 revolutions per minute 70 brake horsepower could be obtained, and a maximum of 80 brake horse-power was actually attained with the type. The flywheel, fitted as with the original 35 horse-power engine, weighed 37 lbs.; with this and with the ignition system the total weight of the engine was only 250 lbs., or 4.2 lbs. per horse-power at the normal rating. In this design, however, low weight in relation to power was not the ruling factor, for Green gave more attention to reliability and economy of fuel consumption, which latter was approximately 0.6 pint of petrol per brake horse-power per hour. Both the oil for lubricating the bearings and the water for cooling the cylinders were circulated by pumps, and all parts of the valve gear, etc., were completely enclosed for protection from dust. A later development of the Green engine was a six-cylindered vertical, cylinder dimensions being 5.5 inch diameter by 6 inch stroke, developing 120 brake horsepower when running at 1,250 revolutions per minute. The total weight of the engine with ignition system 398 was 440 lbs., or 3.66 lbs. per horse-power. One of these engines was used on the machine which, in 1909, won the prize of L1,000 for the first circular mile flight, and it may be noted, too, that S. F. Cody, making the circuit of England in 1911, used a four-cylinder Green engine. Again, it was a Green engine that in 1914 won the L5,000 prize offered for the best aero engine in the Naval and Military aeroplane engine competition. Manufacture of the Green engines, in the period of the War, had standardised to the production of three types. Two of these were six-cylinder models, giving respectively 100 and 150 brake horse-power, and the third was a twelve-cylindered model rated at 275 brake horse-power. In 1910 J. S. Critchley compiled a list showing the types of engine then being manufactured; twenty-two out of a total of seventy-six were of the four-cylindered vertical type, and in addition to these there were two six-cylindered verticals. The sizes of the four-cylinder types ranged from 26 up to 118 brake horse-power; fourteen of them developed less than 50 horse-power, and only two developed over 100 horse-power. It became apparent, even in the early stages of heavier-than-air flying, that four-cylinder engines did not produce the even torque that was required for the rotation of the power shaft, even though a flywheel was fitted to the engine. With this type of engine the breakage of air-screws was of frequent occurrence, and an engine having a more regular rotation was sought, both for this and to avoid the excessive vibration often experienced with the four-cylinder type. Another, point that forced itself on engine builders was that the increased power which was becoming necessary for the propulsion of aircraft made an increase in the number of cylinders essential, in order to obtain a light engine. An instance of the weight reduction obtainable in using six cylinders instead of four is shown in Critchley's list, for one of the four-cylinder engines developed 118.5 brake horse-power and weighed 1,100 lbs., whereas a six-cylinder engine by the same manufacturer developed 117.5 brake horse-power with a weight of 880 lbs., the respective cylinder dimensions being 7.48 diameter by 9.06 stroke for the four-cylinder engine, and 6.1 diameter by 7.28 stroke for the six-cylinder type. A list of aeroplane engines, prepared in 1912 by Graham Clark, showed that, out of the total number of 112 engines then being manufactured, forty-two were of the vertical type, and of this number twenty-four had four-cylinders while sixteen were six-cylindered. The German aeroplane engine trials were held a year later, and sixty-six engines entered the competition, fourteen of these being made with air-cooled cylinders. All of the ten engines that were chosen for the final trials were of the water-cooled type, and the first place was won by a Benz four-cylinder vertical engine which developed 102 brake horse-power at 1,288 revolutions per minute. The cylinder dimensions of this engine were 5.1 inch diameter by 7.1 inch stroke, and the weight of the engine worked out at 3.4 lbs. per brake horse-power. During the trials the full-load petrol consumption was 0.53 pint per horse-power per hour, and the amount of lubricating oil used was 0.0385 pint per brake horse-power per hour. In general construction this Benz engine was somewhat similar to the Green engine already described; the overhead valves, fitted in the tops of the cylinders, were similarly arranged, as was the cam-shaft; two springs were fitted to each of the valves to guard against the possibility of the engine being put out of action by breakage of one of the springs, and ignition was obtained by two high-tension magnetos giving simultaneous sparks in each cylinder by means of two sparking plugs--this dual ignition reduced the possibility of ignition troubles. The cylinder jackets were made of welded sheet steel so fitted around the cylinder that the head was also water-cooled, and the jackets were corrugated in the middle to admit of independent expansion. Even the lubrication system was duplicated, two sets of pumps being used, one to circulate the main supply of lubricating oil, and the other to give a continuous supply of fresh oil to the bearings, so that if the supply from one pump failed the other could still maintain effective lubrication. Development of the early Daimler type brought about the four-cylinder vertical Mercedes-Daimler engine of 85 horse-power, with cylinders of 5.5 diameter with 5.9 inch stroke, the cylinders being cast in two pairs. The overhead arrangement of valves was adopted, and in later designs push-rods were eliminated, the overhead cam-shaft being adopted in their place. By 1914 the four-cylinder Mercedes-Daimler had been partially displaced from favour by a six-cylindered model, made in two sizes; the first of these gave a nominal brake horse-power of 80, having cylinders of 4.1 inches diameter by 5.5 inches stroke; the second type developed 100 horse-power with cylinders 4.7 inches in diameter and 5.5 inches stroke, both types being run at 1,200 revolutions per minute. The cylinders of both these types were cast in pairs, and, instead of the water jackets forming part of the casting, as in the design of the original four-cylinder Mercedes-Daimler engine, they were made of steel welded to flanges on the cylinders. Steel pistons, fitted with cast-iron rings, were used, and the overhead arrangement of valves and cam-shaft was adopted. About 0.55 pint per brake horse-power per hour was the usual fuel consumption necessary to full load running, and the engine was also economical as regards the consumption of lubricating oil, the lubricating system being 'forced' for all parts, including the cam-shaft. The shape of these engines was very well suited for work with aircraft, being narrow enough to admit of a streamline form being obtained, while all the accessories could be so mounted as to produce little or no wind resistance, and very little obstruction to the pilot's view. The eight-cylinder Mercedes-Daimler engine, used for airship propulsion during the War, developed 240 brake horse-power at 1,100 revolutions per minute; the cylinder dimensions were 6.88 diameter by 6.5 stroke--one of the instances in which the short stroke in relation to bore was very noticeable. Other instances of successful vertical design-the types already detailed are fully sufficient to give particulars of the type generally--are the Panhard, Chenu, Maybach, N.A.G., Argus, Mulag, and the well-known Austro-Daimler, which by 1917 was being copied in every combatant country. There are also the later Wright engines, and in America the Wisconsin six-cylinder vertical, weighing well under 4 lbs. per horse-power, is evidence of the progress made with this first type of aero engine to develop. II. THE VEE TYPE An offshoot from the vertical type, doubling the power of this with only a very slight--if any--increase in the length of crankshaft, the Vee or diagonal type of aero engine leaped to success through the insistent demand for greater power. Although the design came after that of the vertical engine, by 1910, according to Critchley's list of aero engines, there were more Vee type engines being made than any other type, twenty-five sizes being given in the list, with an average rating of 57.4 brake horse-power. The arrangement of the cylinders in Vee form over the crankshaft, enabling the pistons of each pair of opposite cylinders to act upon the same crank pin, permits of a very short, compact engine being built, and also permits of reduction of the weight per horsepower, comparing this with that of the vertical type of engine, with one row of cylinders. Further, at the introduction of this type of engine it was seen that crankshaft vibration, an evil of the early vertical engines, was practically eliminated, as was the want of longitudinal stiffness that characterised the higher-powered vertical engines. Of the Vee type engines shown in Critchley's list in 1910 nineteen different sizes were constructed with eight cylinders, and with horse-powers ranging from thirty to just over the hundred; the lightest of these weighed 2.9 lbs. per horse-power--a considerable advance in design on the average vertical engine, in this respect of weight per horse-power. There were also two sixteen-cylinder engines of Vee design, the larger of which developed 134 horse-power with a weight of only 2 lbs. per brake horse-power. Subsequent developments have indicated that this type, with the further development from it of the double-Vee, or engine with three rows of cylinders, is likely to become the standard design of aero engine where high powers are required. The construction permits of placing every part so that it is easy of access, and the form of the engine implies very little head resistance, while it can be placed on the machine--supposing that machine to be of the single-engine type--in such a way that the view of the pilot is very little obstructed while in flight. An even torque, or great uniformity of rotation, is transmitted to the air-screw by these engines, while the design also permits of such good balance of the engine itself that vibration is practically eliminated. The angle between the two rows of cylinders is varied according to the number of cylinders, in order to give working impulses at equal angles of rotation and thus provide even torque; this angle is determined by dividing the number of degrees in a circle by the number of cylinders in either row of the engine. In an eight-cylindered Vee type engine, the angle between the cylinders is 90 degrees; if it is a twelve-cylindered engine, the angle drops to 60 degrees. One of the earliest of the British-built Vee type engines was an eight-cylinder 50 horse-power by the Wolseley Company, constructed in 1908 with a cylinder bore of 3.75 inches and stroke of 5 inches, running at a normal speed of 1,350 revolutions per minute. With this engine, a gearing was introduced to enable the propeller to run at a lower speed than that of the engine, the slight loss of efficiency caused by the friction of the gearing being compensated by the slower speed of the air-screw, which had higher efficiency than would have been the case if it had been run at the engine speed. The ratio of the gearing--that is, the speed of the air-screw relatively to that of the engine, could be chosen so as to suit exactly the requirements of the air-screw, and the gearing itself, on this engine, was accomplished on the half-speed shaft actuating the valves. Very soon after this first design had been tried out, a second Vee type engine was produced which, at 1,200 revolutions per minute, developed 60 horse-power; the size of this engine was practically identical with that of its forerunner, the only exception being an increase of half an inch in the cylinder stroke--a very long stroke of piston in relation to the bore of the cylinder. In the first of these two engines, which was designed for airship propulsion, the weight had been about 8 lbs. per brake horse-power, no special attempt appearing to have been made to fine down for extreme lightness; in this 60 horse-power design, the weight was reduced to 6.1 lbs. per horse-power, counting the latter as normally rated; the engine actually gave a maximum of 75 brake horse-power, reducing the ratio of weight to power very considerably below the figure given. The accompanying diagram illustrates a later Wolseley model, end elevation, the eight-cylindered 120 horse-power Vee type aero engine of the early war period. With this engine, each crank pin has two connecting rods bearing on it, these being placed side by side and connected to the pistons of opposite cylinders and the two cylinders of the pair are staggered by an amount equal to the width of the connecting rod bearing, to afford accommodation for the rods. The crankshaft was a nickel chrome steel forging, machined hollow, with four crank pins set at 180 degrees to each other, and carried in three bearings lined with anti-friction metal. The connecting rods were made of tubular nickel chrome steel, and the pistons of drawn steel, each being fitted with four piston rings. Of these the two rings nearest to the piston head were of the ordinary cast-iron type, while the others were of phosphor bronze, so arranged as to take the side thrust of the piston. The cylinders were of steel, arranged in two groups or rows of four, the angular distance between them being 90 degrees. In the space above the crankshaft, between the cylinder rows, was placed the valve-operating mechanism, together with the carburettor and ignition system, thus rendering this a very compact and accessible engine. The combustion heads of the cylinders were made of cast-iron, screwed into the steel cylinder barrels; the water-jacket was of spun aluminium, with one end fitting over the combustion head and the other free to slide on the cylinder; the water-joint at the lower end was made tight by a Dermatine ring carried between small flanges formed on the cylinder barrel. Overhead valves were adopted, and in order to make these as large as possible the combustion chamber was made slightly larger in diameter than the cylinder, and the valves set at an angle. Dual ignition was fitted in each cylinder, coil and accumulator being used for starting and as a reserve in case of failure of the high-tension magneto system fitted for normal running. There was a double set of lubricating pumps, ensuring continuity of the oil supply to all the bearings of the engine. The feature most noteworthy in connection with the running of this type of engine was its flexibility; the normal output of power was obtained with 1,150 revolutions per minute of the crankshaft, but, by accelerating up to 1,400 revolutions, a maximum of 147 brake horse-power could be obtained. The weight was about 5 lbs. per horse-power, the cylinder dimensions being 5 inches bore by 7 inches stroke. Economy in running was obtained, the fuel consumption being 0.58 pint per brake horse-power per hour at full load, with an expenditure of about 0.075 pint of lubricating oil per brake horse-power per hour. Another Wolseley Vee type that was standardised was a 90 horse-power eight-cylinder engine running at 1,800 revolutions per minute, with a reducing gear introduced by fitting the air screw on the half-speed shaft. First made semi-cooled--the exhaust valve was left air-cooled, and then entirely water-jacketed--this engine demonstrated the advantage of full water cooling, for under the latter condition the same power was developed with cylinders a quarter of an inch less in diameter than in the semi-cooled pattern; at the same time the weight was brought down to 4 1/2 lbs. per horsepower. A different but equally efficient type of Vee design was the Dorman engine, of which an end elevation is shown; this developed 80 brake horse-power at a speed of 1,300 revolutions per minute, with a cylinder bore of 5 inches; each cylinder was made in cast-iron in one piece with the combustion chamber, the barrel only being water-jacketed. Auxiliary exhaust ports were adopted, the holes through the cylinder wall being uncovered by the piston at the bottom of its stroke--the piston, 4.75 inches in length, was longer than its stroke, so that these ports were covered when it was at the top of the cylinder. The exhaust discharged through the ports into a belt surrounding the cylinder, the belts on the cylinders being connected so that the exhaust gases were taken through a single pipe. The air was drawn through the crank case, before reaching the carburettor, this having the effect of cooling the oil in the crank case as well as warming the air and thus assisting in vaporising the petrol for each charge of the cylinders. The inlet and exhaust valves were of the overhead type, as may be gathered from the diagram, and in spite of cast-iron cylinders being employed a light design was obtained, the total weight with radiator, piping, and water being only 5.5 lbs. per horse-power. Here was the antithesis of the Wolseley type in the matter of bore in relation to stroke; from about 1907 up to the beginning of the war, and even later, there was controversy as to which type--that in which the bore exceeded the stroke, or vice versa--gave greater efficiency. The short-stroke enthusiasts pointed to the high piston speed of the long-stroke type, while those who favoured the latter design contended that full power could not be obtained from each explosion in the short-stroke type of cylinder. It is now generally conceded that the long-stroke engine yields higher efficiency, and in addition to this, so far as car engines are concerned, the method of rating horse-power in relation to bore without taking stroke into account has given the long-stroke engine an advantage, actual horse-power with a long stroke engine being in excess of the nominal rating. This may have had some influence on aero engine design, but, however this may have been, the long-stroke engine has gradually come to favour, and its rival has taken second place. For some time pride of place among British Vee type engines was held by the Sunbeam Company, which, owing to the genius of Louis Coatalen, together with the very high standard of construction maintained by the firm, achieved records and fame in the middle and later periods of the war. Their 225 horse-power twelve-cylinder engine ran at a normal speed of 2,000 revolutions per minute; the air screw was driven through gearing at half this speed, its shaft being separate from the timing gear and carried in ball-bearings on the nose-piece of the engine. The cylinders were of cast-iron, entirely water-cooled; a thin casing formed the water-jacket, and a very light design was obtained, the weight being only 3.2 lbs. per horse-power. The first engine of Sunbeam design had eight cylinders and developed 150 horse-power at 2,000 revolutions per minute; the final type of Vee design produced during the war was twelve-cylindered, and yielded 310 horse-power with cylinders 4.3 inches bore by 6.4 inches stroke. Evidence in favour of the long-stroke engine is afforded in this type as regards economy of working; under full load, working at 2,000 revolutions per minute, the consumption was 0.55 pints of fuel per brake horse-power per hour, which seems to indicate that the long stroke permitted of full use being made of the power resulting from each explosion, in spite of the high rate of speed of the piston. Developing from the Vee type, the eighteen-cylinder 475 brake horse-power engine, designed during the war, represented for a time the limit of power obtainable from a single plant. It was water-cooled throughout, and the ignition to each cylinder was duplicated; this engine proved fully efficient, and economical in fuel consumption. It was largely used for seaplane work, where reliability was fully as necessary as high power. The abnormal needs of the war period brought many British firms into the ranks of Vee-type engine-builders, and, apart from those mentioned, the most notable types produced are the Rolls-Royce and the Napier. The first mentioned of these firms, previous to 1914 had concentrated entirely on car engines, and their very high standard of production in this department of internal combustion engine work led, once they took up the making of aero engines, to extreme efficiency both of design and workmanship. The first experimental aero engine, of what became known as the 'Eagle' type, was of Vee design--it was completed in March of 1915--and was so successful that it was standardised for quantity production. How far the original was from the perfection subsequently ascertained is shown by the steady increase in developed horse-power of the type; originally designed to develop 200 horse-power, it was developed and improved before its first practical trial in October of 1915, when it developed 255 horsepower on a brake test. Research and experiment produced still further improvements, for, without any enlargement of the dimensions, or radical alteration in design, the power of the engine was brought up to 266 horse-power by March of 1916, the rate of revolutions of 1,800 per minute being maintained throughout. July, 1916 gave 284 horse-power; by the cud of the year this had been increased to 322 horse-power; by September of 1917 the increase was to 350 horse-power, and by February of 1918 then 'Eagle' type of engine was rated at 360 horse-power, at which standard it stayed. But there is no more remarkable development in engine design than this, a 75 per cent increase of power in the same engine in a period of less than three years. To meet the demand for a smaller type of engine for use on training machines, the Rolls-Royce firm produced the 'Hawk' Vee-type engine of 100 horsepower, and, intermediately between this and the 'Eagle,' the 'Falcon' engine came to being with an original rated horse-power of 205 at 1,800 revolutions per minute, in April of 1916. Here was another case of growth of power in the same engine through research, almost similar to that of the 'Eagle' type, for by July of 1918 the 'Falcon' was developing 285 horse-power with no radical alteration of design. Finally, in response to the constant demand for increase of power in a single plant, the Rolls-Royce company designed and produced the 'Condor' type of engine, which yielded 600 horse-power on its first test in August of 1918. The cessation of hostilities and consequent falling off in the demand for extremely high-powered plants prevented the 'Condor' being developed to its limit, as had been the 'Falcon' and 'Eagle' types. The 'Eagle 'engine was fitted to the two Handley-Page aeroplanes--which made flights from England to India--it was virtually standard on the Handley-Page bombers of the later War period, though to a certain extent the American 'Liberty' engine was also used. Its chief record, however, is that of being the type fitted to the Vickers-Vimy aeroplane which made the first Atlantic flight, covering the distance of 1,880 miles at a speed averaging 117 miles an hour. The Napier Company specialised on one type of engine from the outset, a power plant which became known as the 'Lion' engine, giving 450 horse-power with twelve cylinders arranged in three rows of four each. Considering the engine as 'dry,' or without fuel and accessories, an abnormally light weight per horse-power--only 1.89 lbs.--was attained when running at the normal rate of revolution. The cylinders and water-jackets are of steel, and there is fitted a detachable aluminium cylinder head containing inlet and exhaust valves and valve actuating mechanism; pistons are of aluminium alloy, and there are two inlet and two exhaust valves to each cylinder, the whole of the valve mechanism being enclosed in an oil-tight aluminium case. Connecting rods and crankshaft are of steel, the latter being machined from a solid steel forging and carried in five roller bearings and one plain bearing at the forward end. The front end of the crank-case encloses reduction gear for the propeller shaft, together with the shaft and bearings. There are two suction and one pressure type oil pumps driven through gears at half-engine speed, and two 12 spark magnetos, giving 2 sparks in each cylinder. The cylinders are set with the central row vertical, and the two side rows at angles of 60 degrees each; cylinder bore is 5 1/2 inches, and stroke 5 1/8 inches; the normal rate of revolution is 1,350 per minute, and the reducing gear gives one revolution of the propeller shaft to 1.52 revolutions of crankshaft. Fuel consumption is 0.48lbs. of fuel per brake horse-power hour at full load, and oil consumption is 0.020 lbs. per brake horsepower hour. The dry weight of the engine, complete with propeller boss, carburettors, and induction pipes, is 850 lbs., and the gross weight in running order, with fuel and oil for six hours working, is 2,671 lbs., exclusive of cooling water. To this engine belongs an altitude record of 30,500 feet, made at Martlesham, near Ipswich, on January 2nd, 1919, by Captain Lang, R.A.F., the climb being accomplished in 66 minutes 15 seconds. Previous to this, the altitude record was held by an Italian pilot, who made 25,800 feet in an hour and 57 minutes in 1916. Lang's climb was stopped through the pressure of air, at the altitude he reached, being insufficient for driving the small propellers on the machine which worked the petrol and oil pumps, or he might have made the height said to have been attained by Major Schroeder on February 27th, 1920, at Dayton, Ohio. Schroeder is said to have reached an altitude of 36,020 feet on a Napier biplane, and, owing to failure of the oxygen supply, to have lost consciousness, fallen five miles, righted his machine when 2,000 feet in the air, and alighted successfully. Major Schroeder is an American. Turning back a little, and considering other than British design of Vee and double-Vee or 'Broad arrow' type of engine, the Renault firm from the earliest days devoted considerable attention to the development of this type, their air-cooled engines having been notable examples from the earliest days of heavier-than-air machines. In 1910 they were making three sizes of eight-cylindered Vee-type engines, and by 1915 they had increased to the manufacture of five sizes, ranging from 25 to 100 brake horse-power, the largest of the five sizes having twelve cylinders but still retaining the air-cooled principle. The De Dion firm, also, made Vee-type engines in 1914, being represented by an 80 horse-power eight-cylindered engine, air-cooled, and a 150 horse-power, also of eight cylinders, water-cooled, running at a normal rate of 1,600 revolutions per minute. Another notable example of French construction was the Panhard and Levassor 100 horse-power eight-cylinder Vee engine, developing its rated power at 1,500 revolutions per minute, and having the--for that time--low weight of 4.4 lbs. per horse-power. American Vee design has followed the British fairly cclosely; the Curtiss Company produced originally a 75 horse-power eight-cylinder Vee type running at 1,200 revolutions per minute, supplementing this with a 170 horse-power engine running at 1,600 revolutions per minute, and later with a twelve-cylinder model Vee type, developing 300 horse-power at 1,500 revolutions per minute, with cylinder bore of 5 inches and stroke of 7 inches. An exceptional type of American design was the Kemp Vee engine of 80 horse-power in which the cylinders were cooled by a current of air obtained from a fan at the forward end of the engine. With cylinders of 4.25 inches bore and 4.75 inches stroke, the rater power was developed at 1,150 revolutions per minute, and with the engine complete the weight was only 4.75 lbs. per horse-power. III. THE RADIAL TYPE The very first successful design of internal combustion aero engine made was that of Charles Manly, who built a five-cylinder radial engine in 1901 for use with Langley's 'aerodrome,' as the latter inventor decided to call what has since become known as the aeroplane. Manly made a number of experiments, and finally decided on radial design, in which the cylinders are so rayed round a central crank-pin that the pistons act successively upon it; by this arrangement a very short and compact engine is obtained, with a minimum of weight, and a regular crankshaft rotation and perfect balance of inertia forces. When Manly designed his radial engine, high speed internal combustion engines were in their infancy, and the difficulties in construction can be partly realised when the lack of manufacturing methods for this high-class engine work, and the lack of experimental data on the various materials, are taken into account. During its tests, Manly's engine developed 52.4 brake horsepower at a speed of 950 revolutions per minute, with the remarkably low weight of only 2.4 lbs. per horsepower; this latter was increased to 3.6 lbs. when the engine was completed by the addition of ignition system, radiator, petrol tank, and all accessories, together with the cooling water for the cylinders. In Manly's engine, the cylinders were of steel, machined outside and inside to 1/16 of an inch thickness; on the side of cylinder, at the top end, the valve chamber was brazed, being machined from a solid forging, The casing which formed the water-jacket was of sheet steel, 1/50 of an inch in thickness, and this also was brazed on the cylinder and to the valve chamber. Automatic inlet valves were fitted, and the exhaust valves were operated by a cam which had two points, 180 degrees apart; the cam was rotated in the opposite direction to the engine at one-quarter engine speed. Ignition was obtained by using a one-spark coil and vibrator for all cylinders, with a distributor to select the right cylinder for each spark--this was before the days of the high-tension magneto and the almost perfect ignition systems that makers now employ. The scheme of ignition for this engine was originated by Manly himself, and he also designed the sparking plugs fitted in the tops of the cylinders. Through fear of trouble resulting if the steel pistons worked on the steel cylinders, cast iron liners were introduced in the latter, 1/16 of an inch thick. The connecting rods of this engine were of virtually the same type as is employed on nearly all modern radial engines. The rod for one cylinder had a bearing along the whole of the crank pin, and its end enclosed the pin; the other four rods had bearings upon the end of the first rod, and did not touch the crank pin. The accompanying diagram shows this construction, together with the means employed for securing the ends of the four rods--the collars were placed in position after the rods had been put on. The bearings of these rods did not receive any of the rubbing effect due to the rotation of the crank pin, the rubbing on them being only that of the small angular displacement of the rods during each revolution; thus there was no difficulty experienced with the lubrication. Another early example of the radial type of engine was the French Anzani, of which type one was fitted to the machine with which Bleriot first crossed the English Channel--this was of 25 horse-power. The earliest Anzani engines were of the three-cylinder fan type, one cylinder being vertical, and the other two placed at an angle of 72 degrees on each side, as the possibility of over-lubrication of the bottom cylinders was feared if a regular radial construction were adopted. In order to overcome the unequal balance of this type, balance weights were fitted inside the crank case. The final development of this three-cylinder radial was the 'Y' type of engine, in which the cylinders were regularly disposed at 120 degrees apart, the bore was 4.1, stroke 4.7 inches, and the power developed was 30 brake horse-power at 1,300 revolutions per minute. Critchley's list of aero engines being constructed in 1910 shows twelve of the radial type, with powers of between 14 and 100 horse-power, and with from three to ten cylinder--this last is probably the greatest number of cylinders that can be successfully arranged in circular form. Of the twelve types of 1910, only two were water-cooled, and it is to be noted that these two ran at the slowest speeds and had the lowest weight per horse-power of any. The Anzani radial was considerably developed special attention being paid to this type by its makers and by 1914 the Anzani list comprised seven different sizes of air-cooled radials. Of these the largest had twenty cylinders, developing 200 brake horse-power--it was virtually a double radial--and the smallest was the original 30 horse-power three-cylinder design. A six-cylinder model was formed by a combination of two groups of three cylinders each, acting upon a double-throw crankshaft; the two crank pins were set at 180 degrees to each other, and the cylinder groups were staggered by an amount equal to the distance between the centres of the crank pins. Ten-cylinder radial engines are made with two groups of five cylinders acting upon two crank pins set at 180 degrees to each other, the largest Anzani 'ten' developed 125 horsepower at 1,200 revolutions per minute, the ten cylinders being each 4.5 inches in bore with stroke of 5.9 inches, and the weight of the engine being 3.7 lbs. per horse-power. In the 200 horse-power Anzani radial the cylinders are arranged in four groups of five each, acting on two crank pins. The bore of the cylinders in this engine is the same as in the three-cylinder, but the stroke is increased to 5.5 inches. The rated power is developed at 1,300 revolutions per minute, and the engine complete weighs 3.4 lbs. per horse-power. With this 200 horse-power Anzani, a petrol consumption of as low as 0.49 lbs. of fuel per brake horse-power per hour has been obtained, but the consumption of lubricating oil is compensatingly high, being up to one-fifth of the fuel used. The cylinders are set desaxe with the crank shaft, and are of cast-iron, provided with radiating ribs for air-cooling; they are attached to the crank case by long bolts passing through bosses at the top of the cylinders, and connected to other bolts at right angles through the crank case. The tops of the cylinders are formed flat, and seats for the inlet and exhaust valves are formed on them. The pistons are cast-iron, fitted with ordinary cast-iron spring rings. An aluminium crank case is used, being made in two halves connected together by bolts, which latter also attach the engine to the frame of the machine. The crankshaft is of nickel steel, made hollow, and mounted on ball-bearings in such a manner that practically a combination of ball and plain bearings is obtained; the central web of the shaft is bent to bring the centres of the crank pins as close together as possible, leaving only room for the connecting rods, and the pins are 180 degrees apart. Nickel steel valves of the cone-seated, poppet type are fitted, the inlet valves being automatic, and those for the exhaust cam-operated by means of push-rods. With an engine having such a number of cylinders a very uniform rotation of the crankshaft is obtained, and in actual running there are always five of the cylinders giving impulses to the crankshaft at the same time. An interesting type of pioneer radial engine was the Farcot, in which the cylinders were arranged in a horizontal plane, with a vertical crankshaft which operated the air-screw through bevel gearing. This was an eight-cylinder engine, developing 64 horse-power at 1,200 revolutions per minute. The R.E.P. type,in the early days, was a 'fan' engine, but the designer, M. Robert Pelterie, turned from this design to a seven-cylinder radial, which at 1,100 revolutions per minute gave 95 horse-power. Several makers entered into radial engine development in the years immediately preceding the War, and in 1914 there were some twenty-two different sizes and types, ranging from 30 to 600 horse-power, being made, according to report; the actual construction of the latter size at this time, however, is doubtful. Probably the best example of radial construction up to the outbreak of War was the Salmson (Canton-Unne) water-cooled, of which in 1914 six sizes were listed as available. Of these the smallest was a seven-cylinder 90 horse-power engine, and the largest, rated at 600 horse-power, had eighteen cylinders. These engines, during the War, were made under license by the Dudbridge Ironworks in Great Britain. The accompanying diagram shows the construction of the cylinders in the 200 horse-power size, showing the method of cooling, and the arrangement of the connecting rods. A patent planetary gear, also shown in the diagram, gives exactly the same stroke to all the pistons. The complete engine has fourteen cylinders, of forged steel machined all over, and so secured to the crank case that any one can be removed without parting the crank case. The water-jackets are of spun copper, brazed on to the cylinder, and corrugated so as to admit of free expansion; the water is circulated by means of a centrifugal pump. The pistons are of cast-iron, each fitted with three rings, and the connecting rods are of high grade steel, machined all over and fitted with bushes of phosphor bronze; these rods are connected to a central collar, carried on the crank pin by two ball-bearings. The crankshaft has a single throw, and is made in two parts to allow the cage for carrying the big end-pins of the connecting rods to be placed in position. The casing is in two parts, on one of which the brackets for fixing the engine are carried, while the other part carries the valve-gear. Bolts secure the two parts together. The mechanically-operated steel valves on the cylinders are each fitted with double springs and the valves are operated by rods and levers. Two Zenith carburettors are fitted on the rear half of the crank case, and short induction pipes are led to each cylinder; each of the carburettors is heated by the exhaust gases. Ignition is by two high-tension magnetos, and a compressed air self-starting arrangement is provided. Two oil pumps are fitted for lubricating purposes, one of which forces oil to the crankshaft and connecting-rod bearings, while the second forces oil to the valve gear, the cylinders being so arranged that the oil which flows along the walls cannot flood the lower cylinders. This engine operates upon a six-stroke cycle, a rather rare arrangement for internal combustion engines of the electrical ignition type; this is done in order to obtain equal angular intervals for the working impulses imparted to the rotating crankshaft, as the cylinders are arranged in groups of seven, and all act upon the one crankshaft. The angle, therefore, between the impulses is 77 1/7 degrees. A diagram is inset giving a side view of the engine, in order to show the grouping of the cylinders. The 600 horse-power Salmson engine was designed with a view to fitting to airships, and was in reality two nine-cylindered engines, with a gear-box connecting them; double air-screws were fitted, and these were so arranged that either or both of them might be driven by either or both engines; in addition to this, the two engines were complete and separate engines as regards carburation and ignition, etc., so that they could be run independently of each other. The cylinders were exceptionally 'long stroke,' being 5.9 inches bore to 8.27 inches stroke, and the rated power was developed at 1,200 revolutions per minute, the weight of the complete engine being only 4.1 lbs. per horse-power at the normal rating. A type of engine specially devised for airship propulsion is that in which the cylinders are arranged horizontally instead of vertically, the main advantages of this form being the reduction of head resistance and less obstruction to the view of the pilot. A casing, mounted on the top of the engine, supports the air-screw, which is driven through bevel gearing from the upper end of the crankshaft. With this type of engine a better rate of air-screw efficiency is obtained by gearing the screw down to half the rate of revolution of the engine, this giving a more even torque. The petrol consumption of the type is very low, being only 0.48 lbs. per horse-power per hour, and equal economy is claimed as regards lubricating oil, a consumption of as little as 0.04 lbs. per horse-power per hour being claimed. Certain American radial engines were made previous to 1914, the principal being the Albatross six-cylinder engines of 50 and 100 horse-powers. Of these the smaller size was air-cooled, with cylinders of 4.5 inches bore and 5 inches stroke, developing the rated power at 1,230 revolutions per minute, with a weight of about 5 lbs. per horse-power. The 100 horse-power size had cylinders of 5.5 inches bore, developing its rated power at 1,230 revolutions per minute, and weighing only 2.75 lbs. per horse-power. This engine was markedly similar to the six-cylindered Anzani, having all the valves mechanically operated, and with auxiliary exhaust ports at the bottoms of the cylinders, overrun by long pistons. These Albatross engines had their cylinders arranged in two groups of three, with each group of three pistons operating on one of two crank pins, each 180 degrees apart. The radial type of engine, thanks to Charles Manly, had the honour of being first in the field as regards aero work. Its many advantages, among which may be specially noted the very short crankshaft as compared with vertical, Vee, or 'broad arrow' type of engine, and consequent greater rigidity, ensure it consideration by designers of to-day, and render it certain that the type will endure. Enthusiasts claim that the 'broad arrow' type, or Vee with a third row of cylinders inset between the original two, is just as much a development from the radial engine as from the vertical and resulting Vee; however this may be, there is a place for the radial type in air-work for as long as the internal combustion engine remains as a power plant. IV. THE ROTARY TYPE M. Laurent Seguin, the inventor of the Gnome rotary aero engine, provided as great a stimulus to aviation as any that was given anterior to the war period, and brought about a great advance in mechanical flight, since these well-made engines gave a high-power output for their weight, and were extremely smooth in running. In the rotary design the crankshaft of the engine is stationary, and the cylinders, crank case, and all their adherent parts rotate; the working is thus exactly opposite in principle to that of the radial type of aero engine, and the advantage of the rotary lies in the considerable flywheel effect produced by the revolving cylinders, with consequent evenness of torque. Another advantage is that air-cooling, adopted in all the Gnome engines, is rendered much more effective by the rotation of the cylinders, though there is a tendency to distortion through the leading side of each cylinder being more efficiently cooled than the opposite side; advocates of other types are prone to claim that the air resistance to the revolving cylinders absorbs some 10 per cent of the power developed by the rotary engine, but that has not prevented the rotary from attaining to great popularity as a prime mover. There were, in the list of aero engines compiled in 1910, five rotary engines included, all air-cooled. Three of these were Gnome engines, and two of the make known as 'International.' They ranged from 21.5 to 123 horse-power, the latter being rated at only 1.8 lbs. weight per brake horse-power, and having fourteen cylinders, 4.33 inches in diameter by 4.7 inches stroke. By 1914 forty-three different sizes and types of rotary engine were being constructed, and in 1913 five rotary type engines were entered for the series of aeroplane engine trials held in Germany. Minor defects ruled out four of these, and only the German Bayerischer Motoren Flugzeugwerke completed the seven-hour test prescribed for competing engines. Its large fuel consumption barred this engine from the final trials, the consumption being some 0.95 pints per horse-power per hour. The consumption of lubricating oil, also was excessive, standing at 0.123 pint per horse-power per hour. The engine gave 37.5 effective horse-power during its trial, and the loss due to air resistance was 4.6 horse-power, about 11 per cent. The accompanying drawing shows the construction of the engine, in which the seven cylinders are arranged radially on the crank case; the method of connecting the pistons to the crank pins can be seen. The mixture is drawn through the crank chamber, and to enter the cylinder it passes through the two automatic valves in the crown of the piston; the exhaust valves are situated in the tops of the cylinders, and are actuated by cams and push-rods. Cooling of the cylinder is assisted by the radial rings, and the diameter of these rings is increased round the hottest part of the cylinder. When long flights are undertaken the advantage of the light weight of this engine is more than counterbalanced by its high fuel and lubricating oil consumption, but there are other makes which are much better than this seven-cylinder German in respect of this. Rotation of the cylinders in engines of this type is produced by the side pressure of the pistons on the cylinder walls, and in order to prevent this pressure from becoming abnormally large it is necessary to keep the weight of the piston as low as possible, as the pressure is produced by the tangential acceleration and retardation of the piston. On the upward stroke the circumferential velocity of the piston is rapidly increased, which causes it to exert a considerable tangential pressure on the side of the cylinder, and on the return stroke there is a corresponding retarding effect due to the reduction of the circumferential velocity of the piston. These side pressures cause an appreciable increase in the temperatures of the cylinders and pistons, which makes it necessary to keep the power rating of the engines fairly low. Seguin designed his first Gnome rotary as a 34 horse-power engine when run at a speed of 1,300 revolutions per minute. It had five cylinders, and the weight was 3.9 lbs. per horse-power. A seven-cylinder model soon displaced this first engine, and this latter, with a total weight of 165 lbs., gave 61.5 horse-power. The cylinders were machined out of solid nickel chrome-steel ingots, and the machining was carried out so that the cylinder walls were under 1/6 of an inch in thickness. The pistons were cast-iron, fitted each with two rings, and the automatic inlet valve to the cylinder was placed in the crown of the piston. The connecting rods, of 'H' section, were of nickel chrome-steel, and the large end of one rod, known as the 'master-rod' embraced the crank pin; on the end of this rod six hollow steel pins were carried, and to these the remaining six connecting-rods were attached. The crankshaft of the engine was made of nickel chrome-steel, and was in two parts connected together at the crank pin; these two parts, after the master-rod had been placed in position and the other connecting rods had been attached to it, were firmly secured. The steel crank case was made in five parts, the two central ones holding the cylinders in place, and on one side another of the five castings formed a cam-box, to the outside of which was secured the extension to which the air-screw was attached. On the other side of the crank case another casting carried the thrust-box, and the whole crank case, with its cylinders and gear, was carried on the fixed crank shaft by means of four ball-bearings, one of which also took the axial thrust of the air-screw. For these engines, castor oil is the lubricant usually adopted, and it is pumped to the crankshaft by means of a gear-driven oil pump; from this shaft the other parts of the engine are lubricated by means of centrifugal force, and in actual practice sufficient unburnt oil passes through the cylinders to lubricate the exhaust valve, which partly accounts for the high rate of consumption of lubricating oil. A very simple carburettor of the float less, single-spray type was used, and the mixture was passed along the hollow crankshaft to the interior of the crank case, thence through the automatic inlet valves in the tops of the pistons to the combustion chambers of the cylinders. Ignition was by means of a high-tension magneto specially geared to give the correct timing, and the working impulses occurred at equal angular intervals of 102.85 degrees. The ignition was timed so that the firing spark occurred when the cylinder was 26 degrees before the position in which the piston was at the outer end of its stroke, and this timing gave a maximum pressure in the cylinder just after the piston had passed this position. By 1913, eight different sizes of the Gnome engine were being constructed, ranging from 45 to 180 brake horse-power; four of these were single-crank engines one having nine and the other three having seven cylinders. The remaining four were constructed with two cranks; three of them had fourteen cylinders apiece, ranged in groups of seven, acting on the cranks, and the one other had eighteen cylinders ranged in two groups of nine, acting on its two cranks. Cylinders of the two-crank engines are so arranged (in the fourteen-cylinder type) that fourteen equal angular impulses occur during each cycle; these engines are supported on bearings on both sides of the engine, the air-screw being placed outside the front support. In the eighteen-cylinder model the impulses occur at each 40 degrees of angular rotation of the cylinders, securing an extremely even rotation of the air-screw. In 1913 the Gnome Monosoupape engine was introduced, a model in which the inlet valve to the cylinder was omitted, while the piston was of the ordinary cast-iron type. A single exhaust valve in the cylinder head was operated in a manner similar to that on the previous Gnome engines, and the fact of this being the only valve on the cylinder gave the engine its name. Each cylinder contained ports at the bottom which communicated with the crank chamber, and were overrun by the piston when this was approaching the bottom end of its stroke. During the working cycle of the engine the exhaust valve was opened early to allow the exhaust gases to escape from the cylinder, so that by the time the piston overran the ports at the bottom the pressure within the cylinder was approximately equal to that in the crank case, and practically no flow of gas took place in either direction through the ports. The exhaust valve remained open as usual during the succeeding up-stroke of the piston, and the valve was held open until the piston had returned through about one-third of its downward stroke, thus permitting fresh air to enter the cylinder. The exhaust valve then closed, and the downward motion of the piston, continuing, caused a partial vacuum inside the cylinder; when the piston overran the ports, the rich mixture from the crank case immediately entered. The cylinder was then full of the mixture, and the next upward stroke of the piston compressed the charge; upon ignition the working cycle was repeated. The speed variation of this engine was obtained by varying the extent and duration of the opening of the exhaust valves, and was controlled by the pilot by hand-operated levers acting on the valve tappet rollers. The weight per horsepower of these engines was slightly less than that of the two-valve type, while the lubrication of the gudgeon pin and piston showed an improvement, so that a lower lubricating oil consumption was obtained. The 100 horse-power Gnome Monosoupape was built with nine cylinders, each 4.33 inches bore by 5.9 inches stroke, and it developed its rated power at 1,200 revolutions per minute. An engine of the rotary type, almost as well known as the Gnome, is the Clerget, in which both cylinders and crank case are made of steel, the former having the usual radial fins for cooling. In this type the inlet and exhaust valves are both located in the cylinder head, and mechanically operated by push-rods and rockers. Pipes are carried from the crank case to the inlet valve casings to convey the mixture to the cylinders, a carburettor of the central needle type being used. The carburetted mixture is taken into the crank case chamber in a manner similar to that of the Gnome engine. Pistons of aluminium alloy, with three cast-iron rings, are fitted, the top ring being of the obturator type. The large end of one of the nine connecting rods embraces the crank pin and the pressure is taken on two ball-bearings housed in the end of the rod. This carries eight pins, to which the other rods are attached, and the main rod being rigid between the crank pin and piston pin determines the position of the pistons. Hollow connecting-rods are used, and the lubricating oil for the piston pins passes from the crankshaft through the centres of the rods. Inlet and exhaust valves can be set quite independently of one another--a useful point, since the correct timing of the opening of these valves is of importance. The inlet valve opens 4 degrees from top centre and closes after the bottom dead centre of the piston; the exhaust valve opens 68 degrees before the bottom centre and closes 4 degrees after the top dead centre of the piston. The magnetos are set to give the spark in the cylinder at 25 degrees before the end of the compression stroke--two high-tension magnetos are used: if desired, the second one can be adjusted to give a later spark for assisting the starting of the engine. The lubricating oil pump is of the valveless two-plunger type, so geared that it runs at seven revolutions to 100 revolutions of the engine; by counting the pulsations the speed of the engine can be quickly calculated by multiplying the pulsations by 100 and dividing by seven. In the 115 horse-power nine-cylinder Clerget the cylinders are 4.7 bore with a 6.3 inches stroke, and the rated power of the engine is obtained at 1,200 revolutions per minute. The petrol consumption is 0.75 pint per horse-power per hour. A third rotary aero engine, equally well known with the foregoing two, is the Le Rhone, made in four different sizes with power outputs of from 50 to 160 horse-power; the two smaller sizes are single crank engines with seven and nine cylinders respectively, and the larger sizes are of double-crank design, being merely the two smaller sizes doubled--fourteen and eighteen-cylinder engines. The inlet and exhaust valves are located in the cylinder head, and both valves are mechanically operated by one push-rod and rocker, radial pipes from crank case to inlet valve casing taking the mixture to the cylinders. The exhaust valves are placed on the leading, or air-screw side, of the engine, in order to get the fullest possible cooling effect. The rated power of each type of engine is obtained at 1,200 revolutions per minute, and for all four sizes the cylinder bore is 4.13 inches, with a 5.5 inches piston stroke. Thin cast-iron liners are shrunk into the steel cylinders in order to reduce the amount of piston friction. Although the Le Rhone engines are constructed practically throughout of steel, the weight is only 2.9 lbs. per horse-power in the eighteen-cylinder type. American enterprise in the construction of the rotary type is perhaps best illustrated in the 'Gyro 'engine; this was first constructed with inlet valves in the heads of the pistons, after the Gnome pattern, the exhaust valves being in the heads of the cylinders. The inlet valve in the crown of each piston was mechanically operated in a very ingenious manner by the oscillation of the connecting-rod. The Gyro-Duplex engine superseded this original design, and a small cross-section illustration of this is appended. It is constructed in seven and nine-cylinder sizes, with a power range of from 50 to 100 horse-power; with the largest size the low weight of 2.5 lbs.. per horse-power is reached. The design is of considerable interest to the internal combustion engineer, for it embodies a piston valve for controlling auxiliary exhaust ports, which also acts as the inlet valve to the cylinder. The piston uncovers the auxiliary ports when it reaches the bottom of its stroke, and at the end of the power stroke the piston is in such a position that the exhaust can escape over the top of it. The exhaust valve in the cylinder head is then opened by means of the push-rod and rocker, and is held open until the piston has completed its upward stroke and returned through more than half its subsequent return stroke. When the exhaust valve closes, the cylinder has a charge of fresh air, drawn in through the exhaust valve, and the further motion of the piston causes a partial vacuum; by the time the piston reaches bottom dead centre the piston-valve has moved up to give communication between the cylinder and the crank case, therefore the mixture is drawn into the cylinder. Both the piston valve and exhaust valve are operated by cams formed on the one casting, which rotates at seven-eighths engine speed for the seven-cylinder type, and nine-tenths engine speed for the nine-cylinder engines. Each of these cams has four or five points respectively, to suit the number of cylinders. The steel cylinders are machined from solid forgings and provided with webs for air-cooling as shown. Cast-iron pistons are used, and are connected to the crankshaft in the same manner as with the Gnome and Le Rhone engines. Petrol is sprayed into the crank case by a small geared pump and the mixture is taken from there to the piston valves by radial pipes. Two separate pumps are used for lubrication, one forcing oil to the crank-pin bearing and the other spraying the cylinders. Among other designs of rotary aero engines the E.J.C. is noteworthy, in that the cylinders and crank case of this engine rotate in opposite directions, and two air-screws are used, one being attached to the end of the crankshaft, and the other to the crank case. Another interesting type is the Burlat rotary, in which both the cylinders and crankshaft rotate in the same direction, the rotation of the crankshaft being twice that of the cylinders as regards speed. This engine is arranged to work on the four-stroke cycle with the crankshaft making four, and the cylinders two, revolutions per cycle. It would appear that the rotary type of engine is capable of but little more improvement--save for such devices as these of the last two engines mentioned, there is little that Laurent Seguin has not already done in the Gnome type. The limitation of the rotary lies in its high fuel and lubricating oil consumption, which renders it unsuited for long-distance aero work; it was, in the war period, an admirable engine for such short runs as might be involved in patrol work 'over the lines,' and for similar purposes, but the watercooled Vee or even vertical, with its much lower fuel consumption, was and is to be preferred for distance work. The rotary air-cooled type has its uses, and for them it will probably remain among the range of current types for some time to come. Experience of matters aeronautical is sufficient to show, however, that prophecy in any direction is most unsafe. V. THE HORIZONTALLY-OPPOSED ENGINE Among the first internal combustion engines to be taken into use with aircraft were those of the horizontally-opposed four-stroke cycle type, and, in every case in which these engines were used, their excellent balance and extremely even torque rendered them ideal-until the tremendous increase in power requirements rendered the type too long and bulky for placing in the fuselage of an aeroplane. As power increased, there came a tendency toward placing cylinders radially round a central crankshaft, and, as in the case of the early Anzani, it may be said that the radial engine grew out of the horizontal opposed piston type. There were, in 1910--that is, in the early days of small power units, ten different sizes of the horizontally opposed engine listed for manufacture, but increase in power requirements practically ruled out the type for air work. The Darracq firm were the leading makers of these engines in 1910; their smallest size was a 24 horsepower engine, with two cylinders each of 5.1 inches bore by 4.7 inches stroke. This engine developed its rated power at 1,500 revolutions per minute, and worked out at a weight of 5 lbs. per horse-power. With these engines the cranks are so placed that two regular impulses are given to the crankshaft for each cycle of working, an arrangement which permits of very even balancing of the inertia forces of the engine. The Darracq firm also made a four-cylindered horizontal opposed piston engine, in which two revolutions were given to the crankshaft per revolution, at equal angular intervals. The Dutheil-Chambers was another engine of this type, and had the distinction of being the second largest constructed. At 1,000 revolutions per minute it developed 97 horse-power; its four cylinders were each of 4.93 inches bore by 11.8 inches stroke--an abnormally long stroke in comparison with the bore. The weight--which owing to the build of the engine and its length of stroke was bound to be rather high, actually amounted to 8.2 lbs. per horse-power. Water cooling was adopted, and the engine was, like the Darracq four-cylinder type, so arranged as to give two impulses per revolution at equal angular intervals of crankshaft rotation. One of the first engines of this type to be constructed in England was the Alvaston, a water-cooled model which was made in 20, 30, and 50 brake horse-power sizes, the largest being a four-cylinder engine. All three sizes were constructed to run at 1,200 revolutions per minute. In this make the cylinders were secured to the crank case by means of four long tie bolts passing through bridge pieces arranged across the cylinder heads, thus relieving the cylinder walls of all longitudinal explosion stresses. These bridge pieces were formed from chrome vanadium steel and milled to an 'H' section, and the bearings for the valve-tappet were forged solid with them. Special attention was given to the machining of the interiors of the cylinders and the combustion heads, with the result that the exceptionally high compression of 95 lbs. per square inch was obtained, giving a very flexible engine. The cylinder heads were completely water-jacketed, and copper water-jackets were also fitted round the cylinders. The mechanically operated valves were actuated by specially shaped cams, and were so arranged that only two cams were required for the set of eight valves. The inlet valves at both ends of the engine were connected by a single feed-pipe to which the carburettor was attached, the induction piping being arranged above the engine in an easily accessible position. Auxiliary air ports were provided in the cylinder walls so that the pistons overran them at the end of their stroke. A single vertical shaft running in ball-bearings operated the valves and water circulating pump, being driven by spiral gearing from the crankshaft at half speed. In addition to the excellent balance obtained with this engine, the makers claimed with justice that the number of working parts was reduced to an absolute minimum. In the two-cylinder Darracq, the steel cylinders were machined from solid, and auxiliary exhaust ports, overrun by the piston at the inner end of its stroke, were provided in the cylinder walls, consisting of a circular row of drilled holes--this arrangement was subsequently adopted on some of the Darracq racing car engines. The water jackets were of copper, soldered to the cylinder walls; both the inlet and exhaust valves were located in the cylinder heads, being operated by rockers and push-rods actuated by cams on the halftime shaft driven from one end of the crankshaft. Ignition was by means of a high-tension magneto, and long induction pipes connected the-ends of the cylinders to the carburettor, the latter being placed underneath the engine. Lubrication was effected by spraying oil into the crank case by means of a pump, and a second pump circulated the cooling water. Another good example of this type of engine was the Eole, which had eight opposed pistons, each pair of which was actuated by a common combustion chamber at the centre of the engine, two crankshafts being placed at the outer ends of the engine. This reversal of the ordinary arrangement had two advantages; it simplified induction, and further obviated the need for cylinder heads, since the explosion drove at two piston heads instead of at one piston head and the top of the cylinder; against this, however, the engine had to be constructed strongly enough to withstand the longitudinal stresses due to the explosions, as the cranks are placed on the outer ends and the cylinders and crank-cases take the full force of each explosion. Each crankshaft drove a separate air-screw. This pattern of engine was taken up by the Dutheil-Chambers firm in the pioneer days of aircraft, when the firm in question produced seven different sizes of horizontal engines. The Demoiselle monoplane used by Santos-Dumont in 1909 was fitted with a two-cylinder, horizontally-opposed Dutheil-Chambers engine, which developed 25 brake horse-power at a speed of 1,100 revolutions per minute, the cylinders being of 5 inches bore by 5.1 inches stroke, and the total weight of the engine being some 120 lbs. The crankshafts of these engines were usually fitted with steel flywheels in order to give a very even torque, the wheels being specially constructed with wire spokes. In all the Dutheil-Chambers engines water cooling was adopted, and the cylinders were attached to the crank cases by means of long bolts passing through the combustion heads. For their earliest machines, the Clement-Bayard firm constructed horizontal engines of the opposed piston type. The best known of these was the 30 horse-power size, which had cylinders of 4.7 inches diameter by 5.1 inches stroke, and gave its rated power at 1,200 revolutions per minute. In this engine the steel cylinders were secured to the crank case by flanges, and radiating ribs were formed around the barrel to assist the air-cooling. Inlet and exhaust valves were actuated by push-rods and rockers actuated from the second motion shaft mounted above the crank case; this shaft also drove the high-tension magneto with which the engine was fitted. A ring of holes drilled round each cylinder constituted auxiliary ports which the piston uncovered at the inner end of its stroke, and these were of considerable assistance not only in expelling exhaust gases, but also in moderating the temperature of the cylinder and of the main exhaust valve fitted in the cylinder head. A water-cooled Clement-Bayard horizontal engine was also made, and in this the auxiliary exhaust ports were not embodied; except in this particular, the engine was very similar to the water-cooled Darracq. The American Ashmusen horizontal engine, developing 100 horse-power, is probably the largest example of this type constructed. It was made with six cylinders arranged on each side of a common crank case, with long bolts passing through the cylinder heads to assist in holding them down. The induction piping and valve-operating gear were arranged below the engine, and the half-speed shaft carried the air-screw. Messrs Palons and Beuse, Germans, constructed a light-weight, air-cooled, horizontally-opposed engine, two-cylindered. In this the cast-iron cylinders were made very thin, and were secured to the crank case by bolts passing through lugs cast on the outer ends of the cylinders; the crankshaft was made hollow, and holes were drilled through the webs of the connecting-rods in order to reduce the weight. The valves were fitted to the cylinder heads, the inlet valves being of the automatic type, while the exhaust valves were mechanically operated from the cam-shaft by means of rockers and push-rods. Two carburettors were fitted, to reduce the induction piping to a minimum; one was attached to each combustion chamber, and ignition was by the normal high-tension magneto driven from the halftime shaft. There was also a Nieuport two-cylinder air-cooled horizontal engine, developing 35 horse-power when running at 1,300 revolutions per minute, and being built at a weight of 5.1 lbs. per horse-power. The cylinders were of 5.3 inches diameter by 5.9 inches stroke; the engine followed the lines of the Darracq and Dutheil-Chambers pretty closely, and thus calls for no special description. The French Kolb-Danvin engine of the horizontal type, first constructed in 1905, was probably the first two-stroke cycle engine designed to be applied to the propulsion of aircraft; it never got beyond the experimental stage, although its trials gave very good results. Stepped pistons were adopted, and the charging pump at one end was used to scavenge the power cylinder at the other ends of the engine, the transfer ports being formed in the main casting. The openings of these ports were controlled at both ends by the pistons, and the location of the ports appears to have made it necessary to take the exhaust from the bottom of one cylinder and from the top of the other. The carburetted mixture was drawn into the scavenging cylinders, and the usual deflectors were cast on the piston heads to assist in the scavenging and to prevent the fresh gas from passing out of the exhaust ports. VI. THE TWO-STROKE CYCLE ENGINE Although it has been little used for aircraft propulsion, the possibilities of the two-stroke cycle engine render some study of it desirable in this brief review of the various types of internal combustion engine applicable both to aeroplanes and airships. Theoretically the two-stroke cycle engine--or as it is more commonly termed, the 'two-stroke,' is the ideal power producer; the doubling of impulses per revolution of the crankshaft should render it of very much more even torque than the four-stroke cycle types, while, theoretically, there should be a considerable saving of fuel, owing to the doubling of the number of power strokes per total of piston strokes. In practice, however, the inefficient scavenging of virtually every two-stroke cycle engine produced nullifies or more than nullifies its advantages over the four-stroke cycle engine; in many types, too, there is a waste of fuel gases through the exhaust ports, and much has yet to be done in the way of experiment and resulting design before the two-stroke cycle engine can be regarded as equally reliable, economical, and powerful with its elder brother. The first commercially successful engine operating on the two-stroke cycle was invented by Mr Dugald Clerk, who in 1881 proved the design feasible. As is more or less generally understood, the exhaust gases of this engine are discharged from the cylinder during the time that the piston is passing the inner dead centre, and the compression, combustion, and expansion of the charge take place in similar manner to that of the four-stroke cycle engine. The exhaust period is usually controlled by the piston overrunning ports in the cylinder at the end of its working stroke, these ports communicating direct with the outer air--the complication of an exhaust valve is thus obviated; immediately after the escape of the exhaust gases, charging of the cylinder occurs, and the fresh gas may be introduced either through a valve in the cylinder head or through ports situated diametrically opposite to the exhaust ports. The continuation of the outward stroke of the piston, after the exhaust ports have been closed, compresses the charge into the combustion chamber of the cylinder, and the ignition of the mixture produces a recurrence of the working stroke. Thus, theoretically, is obtained the maximum of energy with the minimum of expenditure; in practice, however, the scavenging of the power cylinder, a matter of great importance in all internal combustion engines, is often imperfect, owing to the opening of the exhaust ports being of relatively short duration; clearing the exhaust gases out of the cylinder is not fully accomplished, and these gases mix with the fresh charge and detract from its efficiency. Similarly, owing to the shorter space of time allowed, the charging of the cylinder with the fresh mixture is not so efficient as in the four-stroke cycle type; the fresh charge is usually compressed slightly in a separate chamber--crank case, independent cylinder, or charging pump, and is delivered to the working cylinder during the beginning of the return stroke of the piston, while in engines working on the four-stroke cycle principle a complete stroke is devoted to the expulsion of the waste gases of the exhaust, and another full stroke to recharging the cylinder with fresh explosive mixture. Theoretically the two-stroke and the four-stroke cycle engines possess exactly the same thermal efficiency, but actually this is modified by a series of practical conditions which to some extent tend to neutralise the very strong case in favour of the two-stroke cycle engine. The specific capacity of the engine operating on the two-stroke principle is theoretically twice that of one operating on the four-stroke cycle, and consequently, for equal power, the former should require only about half the cylinder volume of the latter; and, owing to the greater superficial area of the smaller cylinder, relatively, the latter should be far more easily cooled than the larger four-stroke cycle cylinder; thus it should be possible to get higher compression pressures, which in turn should result in great economy of working. Also the obtaining of a working impulse in the cylinder for each revolution of the crankshaft should give a great advantage in regularity of rotation--which it undoubtedly does--and the elimination of the operating gear for the valves, inlet and exhaust, should give greater simplicity of design. In spite of all these theoretical--and some practical--advantages the four-stroke cycle engine was universally adopted for aircraft work; owing to the practical equality of the two principles of operation, so far as thermal efficiency and friction losses are concerned, there is no doubt that the simplicity of design (in theory) and high power output to weight ratio (also in theory) ought to have given the 'two-stroke' a place on the aeroplane. But this engine has to be developed so as to overcome its inherent drawbacks; better scavenging methods have yet to be devised--for this is the principal drawback--before the two-stroke can come to its own as a prime mover for aircraft. Mr Dugald Clerk's original two-stroke cycle engine is indicated roughly, as regards principle, by the accompanying diagram, from which it will be seen that the elimination of the ordinary inlet and exhaust valves of the four-stroke type is more than compensated by a separate cylinder which, having a piston worked from the connecting-rod of the power cylinder, was used to charging, drawing the mixture from the carburettor past the valve in the top of the charging cylinder, and then forcing it through the connecting pipe into the power cylinder. The inlet valves both on the charging and the power cylinders are automatic; when the power piston is near the bottom of its stroke the piston in the charging cylinder is compressing the carburetted air, so that as soon as the pressure within the power cylinder is relieved by the exit of the burnt gases through the exhaust ports the pressure in the charging cylinder causes the valve in the head of the power cylinder to open, and fresh mixture flows into the cylinder, replacing the exhaust gases. After the piston has again covered the exhaust ports the mixture begins to be compressed, thus automatically closing the inlet valve. Ignition occurs near the end of the compression stroke, and the working stroke immediately follows, thus giving an impulse to the crankshaft on every down stroke of the piston. If the scavenging of the cylinder were complete, and the cylinder were to receive a full charge of fresh mixture for every stroke, the same mean effective pressure as is obtained with four-stroke cycle engines ought to be realised, and at an equal speed of rotation this engine should give twice the power obtainable from a four-stroke cycle engine of equal dimensions. This result was not achieved, and, with the improvements in construction brought about by experiment up to 1912, the output was found to be only about fifty per cent more than that of a four-stroke cycle engine of the same size, so that, when the charging cylinder is included, this engine has a greater weight per horse-power, while the lowest rate of fuel consumption recorded was 0.68 lb. per horse-power per hour. In 1891 Mr Day invented a two-stroke cycle engine which used the crank case as a scavenging chamber, and a very large number of these engines have been built for industrial purposes. The charge of carburetted air is drawn through a non-return valve into the crank chamber during the upstroke of the piston, and compressed to about 4 lbs. pressure per square inch on the down stroke. When the piston approaches the bottom end of its stroke the upper edge first overruns an exhaust port, and almost immediately after uncovers an inlet port on the opposite side of the cylinder and in communication with the crank chamber; the entering charge, being under pressure, assists in expelling the exhaust gases from the cylinder. On the next upstroke the charge is compressed into the combustion space of the cylinder, a further charge simultaneously entering the crank case to be compressed after the ignition for the working stroke. To prevent the incoming charge escaping through the exhaust ports of the cylinder a deflector is formed on the top of the piston, causing the fresh gas to travel in an upward direction, thus avoiding as far as possible escape of the mixture to the atmosphere. From experiments conducted in 1910 by Professor Watson and Mr Fleming it was found that the proportion of fresh gases which escaped unburnt through the exhaust ports diminished with increase of speed; at 600 revolutions per minute about 36 per cent of the fresh charge was lost; at 1,200 revolutions per minute this was reduced to 20 per cent, and at 1,500 revolutions it was still farther reduced to 6 per cent. So much for the early designs. With regard to engines of this type specially constructed for use with aircraft, three designs call for special mention. Messrs A. Gobe and H. Diard, Parisian engineers, produced an eight-cylindered two-stroke cycle engine of rotary design, the cylinders being co-axial. Each pair of opposite pistons was secured together by a rigid connecting rod, connected to a pin on a rotating crankshaft which was mounted eccentrically to the axis of rotation of the cylinders. The crankshaft carried a pinion gearing with an internally toothed wheel on the transmission shaft which carried the air-screw. The combustible mixture, emanating from a common supply pipe, was led through conduits to the front ends of the cylinders, in which the charges were compressed before being transferred to the working spaces through ports in tubular extensions carried by the pistons. These extensions had also exhaust ports, registering with ports in the cylinder which communicated with the outer air, and the extensions slid over depending cylinder heads attached to the crank case by long studs. The pump charge was compressed in one end of each cylinder, and the pump spaces each delivered into their corresponding adjacent combustion spaces. The charges entered the pump spaces during the suction period through passages which communicated with a central stationary supply passage at one end of the crank case, communication being cut off when the inlet orifice to the passage passed out of register with the port in the stationary member. The exhaust ports at the outer end of the combustion space opened just before and closed a little later than the air ports, and the incoming charge assisted in expelling the exhaust gases in a manner similar to that of the earlier types of two-stroke cycle engine; The accompanying rough diagram assists in showing the working of this engine. Exhibited in the Paris Aero Exhibition of 1912, the Laviator two-stroke cycle engine, six-cylindered, could be operated either as a radial or as a rotary engine, all its pistons acting on a single crank. Cylinder dimensions of this engine were 3.94 inches bore by 5.12 inches stroke, and a power output of 50 horse-power was obtained when working at a rate of 1,200 revolutions per minute. Used as a radial engine, it developed 65 horse-power at the same rate of revolution, and, as the total weight was about 198 lbs., the weight of about 3 lbs. per horse-power was attained in radial use. Stepped pistons were employed, the annular space between the smaller or power piston and the walls of the larger cylinder being used as a charging pump for the power cylinder situated 120 degrees in rear of it. The charging cylinders were connected by short pipes to ports in the crank case which communicated with the hollow crankshaft through which the fresh gas was supplied, and once in each revolution each port in the case registered with the port in the hollow shaft. The mixture which then entered the charging cylinder was transferred to the corresponding working cylinder when the piston of that cylinder had reached the end of its power stroke, and immediately before this the exhaust ports diametrically opposite the inlet ports were uncovered; scavenging was thus assisted in the usual way. The very desirable feature of being entirely valveless was accomplished with this engine, which is also noteworthy for exceedingly compact design. The Lamplough six-cylinder two-stroke cycle rotary, shown at the Aero Exhibition at Olympia in 1911, had several innovations, including a charging pump of rotary blower type. With the six cylinders, six power impulses at regular intervals were given on each rotation; otherwise, the cycle of operations was carried out much as in other two-stroke cycle engines. The pump supplied the mixture under slight pressure to an inlet port in each cylinder, which was opened at the same time as the exhaust port, the period of opening being controlled by the piston. The rotary blower sucked the mixture from the carburettor and delivered it to a passage communicating with the inlet ports in the cylinder walls. A mechanically-operated exhaust valve was placed in the centre of each cylinder head, and towards the end of the working stroke this valve opened, allowing part of the burnt gases to escape to the atmosphere; the remainder was pushed out by the fresh mixture going in through the ports at the bottom end of the cylinder. In practice, one or other of the cylinders was always taking fresh mixture while working, therefore the delivery from the pump was continuous and the mixture had not to be stored under pressure. The piston of this engine was long enough to keep the ports covered when it was at the top of the stroke, and a bottom ring was provided to prevent the mixture from entering the crank case. In addition to preventing leakage, this ring no doubt prevented an excess of oil working up the piston into the cylinder. As the cylinder fired with every revolution, the valve gear was of the simplest construction, a fixed cam lifting each valve as the cylinder came into position. The spring of the exhaust valve was not placed round the stem in the usual way, but at the end of a short lever, away from the heat of the exhaust gases. The cylinders were of cast steel, the crank case of aluminium, and ball-bearings were fitted to the crankshaft, crank pins, and the rotary blower pump. Ignition was by means of a high-tension magneto of the two-spark pattern, and with a total weight of 300 lbs. the maximum output was 102 brake horse-power, giving a weight of just under 3 lbs. per horse-power. One of the most successful of the two-stroke cycle engines was that designed by Mr G. F. Mort and constructed by the New Engine Company. With four cylinders of 3.69 inches bore by 4.5 inches stroke, and running at 1,250 revolutions per minute, this engine developed 50 brake horse-power; the total weight of the engine was 155 lbs., thus giving a weight of 3.1 lbs. per horse-power. A scavenging pump of the rotary type was employed, driven by means of gearing from the engine crankshaft, and in order to reduce weight to a minimum the vanes were of aluminium. This engine was tried on a biplane, and gave very satisfactory results. American design yields two apparently successful two-stroke cycle aero engines. A rotary called the Fredericson engine was said to give an output of 70 brake horse-power with five cylinders 4.5 inches diameter by 4.75 inches stroke, running at 1,000 revolutions per minute. Another, the Roberts two-stroke cycle engine, yielded 100 brake horse-power from six cylinders of the stepped piston design; two carburettors, each supplying three cylinders, were fitted to this engine. Ignition was by means of the usual high-tension magneto, gear-driven from the crankshaft, and the engine, which was water-cooled, was of compact design. It may thus be seen that the two-stroke cycle type got as far as actual experiment in air work, and that with considerable success. So far, however, the greater reliability of the four-stroke cycle has rendered it practically the only aircraft engine, and the two-stroke has yet some way to travel before it becomes a formidable competitor, in spite of its admitted theoretical and questioned practical advantages. VII. ENGINES OF THE WAR PERIOD The principal engines of British, French, and American design used in the war period and since are briefly described under the four distinct types of aero engine; such notable examples as the Rolls-Royce, Sunbeam, and Napier engines have been given special mention, as they embodied--and still embody--all that is best in aero engine practice. So far, however, little has been said about the development of German aero engine design, apart from the early Daimler and other pioneer makes. At the outbreak of hostilities in 1914, thanks to subsidies to contractors and prizes to aircraft pilots, the German aeroplane industry was in a comparatively flourishing condition. There were about twenty-two establishments making different types of heavier-than-air machines, monoplane and biplane, engined for the most part with the four-cylinder Argus or the six-cylinder Mercedes vertical type engines, each of these being of 100 horse-power--it was not till war brought increasing demands on aircraft that the limit of power began to rise. Contemporary with the Argus and Mercedes were the Austro-Daimler, Benz, and N.A.G., in vertical design, while as far as rotary types were concerned there were two, the Oberursel and the Stahlhertz; of these the former was by far the most promising, and it came to virtual monopoly of the rotary-engined plane as soon as the war demand began. It was practically a copy of the famous Gnome rotary, and thus deserves little description. Germany, from the outbreak of war, practically, concentrated on the development of the Mercedes engine; and it is noteworthy that, with one exception, increase of power corresponding with the increased demand for power was attained without increasing the number of cylinders. The various models ranged between 75 and 260 horse-power, the latter being the most recent production of this type. The exception to the rule was the eight-cylinder 240 horse-power, which was replaced by the 260 horse-power six-cylinder model, the latter being more reliable and but very slightly heavier. Of the other engines, the 120 horsepower Argus and the 160 and 225 horse-power Benz were the most used, the Oberursel being very largely discarded after the Fokker monoplane had had its day, and the N.A.G. and Austro-Daimler Daimler also falling to comparative disuse. It may be said that the development of the Mercedes engine contributed very largely to such success as was achieved in the war period by German aircraft, and, in developing the engine, the builders were careful to make alterations in such a way as to effect the least possible change in the design of aeroplane to which they were to be fitted. Thus the engine base of the 175 horse-power model coincided precisely with that of the 150 horse-power model, and the 200 and 240 horse-power models retained the same base dimensions. It was estimated, in 1918, that well over eighty per cent of German aircraft was engined with the Mercedes type. In design and construction, there was nothing abnormal about the Mercedes engine, the keynote throughout being extreme reliability and such simplification of design as would permit of mass production in different factories. Even before the war, the long list of records set up by this engine formed practical application of the wisdom of this policy; Bohn's flight of 24 hours 10 minutes, accomplished on July 10th and 11th, 1914, 9is an instance of this--the flight was accomplished on an Albatross biplane with a 75 horsepower Mercedes engine. The radial type, instanced in other countries by the Salmson and Anzani makes, was not developed in Germany; two radial engines were made in that country before the war, but the Germans seemed to lose faith in the type under war conditions, or it may have been that insistence on standardisation ruled out all but the proved examples of engine. Details of one of the middle sizes of Mercedes motor, the 176 horse-power type, apply very generally to the whole range; this size was in use up to and beyond the conclusion of hostilities, and it may still be regarded as characteristic of modern (1920) German practice. The engine is of the fixed vertical type, has six cylinders in line, not off-set, and is water-cooled. The cam shaft is carried in a special bronze casing, seated on the immediate top of the cylinders, and a vertical shaft is interposed between crankshaft and camshaft, the latter being driven by bevel gearing. On this vertical connecting-shaft the water pump is located, serving to steady the motion of the shaft. Extending immediately below the camshaft is another vertical shaft, driven by bevel gears from the crank-shaft, and terminating in a worm which drives the multiple piston oil pumps. The cylinders are made from steel forgings, as are the valve chamber elbows, which are machined all over and welded together. A jacket of light steel is welded over the valve elbows and attached to a flange on the cylinders, forming a water-cooling space with a section of about 7/16 of an inch. The cylinder bore is 5.5 inches, and the stroke 6.29 inches. The cylinders are attached to the crank case by means of dogs and long through bolts, which have shoulders near their lower ends and are bolted to the lower half of the crank chamber. A very light and rigid structure is thus obtained, and the method of construction won the flattery of imitation by makers of other nationality. The cooling system for the cylinders is extremely efficient. After leaving the water pump, the water enters the top of the front cylinders and passes successively through each of the six cylinders of the row; short tubes, welded to the tops of the cylinders, serve as connecting links in the system. The Panhard car engines for years were fitted with a similar cooling system, and the White and Poppe lorry engines were also similarly fitted; the system gives excellent cooling effect where it is most needed, round the valve chambers and the cylinder heads. The pistons are built up from two pieces; a dropped forged steel piston head, from which depend the piston pin bosses, is combined with a cast-iron skirt, into which the steel head is screwed. Four rings are fitted, three at the upper and one at the lower end of the piston skirt, and two lubricating oil grooves are cut in the skirt, in addition to the ring grooves. Two small rivets retain the steel head on the piston skirt after it has been screwed into position, and it is also welded at two points. The coefficient of friction between the cast-iron and steel is considerably less than that which would exist between two steel parts, and there is less tendency for the skirt to score the cylinder walls than would be the case if all steel were used--so noticeable is this that many makers, after giving steel pistons a trial, discarded them in favour of cast-iron; the Gnome is an example of this, being originally fitted with a steel piston carrying a brass ring, discarded in favour of a cast-iron piston with a percentage of steel in the metal mixture. In the Le Rhone engine the difficulty is overcome by a cast-iron liner to the cylinders. The piston pin of the Mercedes is of chrome nickel steel, and is retained in the piston by means of a set screw and cotter pin. The connecting rods, of I section, are very short and rigid, carrying floating bronze bushes which fit the piston pins at the small end, and carrying an oil tube on each for conveying oil from the crank pin to the piston pin. The crankshaft is of chrome nickel steel, carried on seven bearings. Holes are drilled through each of the crank pins and main bearings, for half the diameter of the shaft, and these are plugged with pressed brass studs. Small holes, drilled through the crank cheeks, serve to convey lubricant from the main bearings to the crank pins. The propeller thrust is taken by a simple ball thrust bearing at the propeller end of the crankshaft, this thrust bearing being seated in a steel retainer which is clamped between the two halves of the crank case. At the forward end of the crankshaft there is mounted a master bevel gear on six splines; this bevel floats on the splines against a ball thrust bearing, and, in turn, the thrust is taken by the crank case cover. A stuffing box prevents the loss of lubricant out of the front end of the crank chamber, and an oil thrower ring serves a similar purpose at the propeller end of the crank chamber. With a motor speed of 1,450 r.p.m., the vertical shaft at the forward end of the motor turns at 2,175 r.p.m., this being the speed of the two magnetos and the water pump. The lower vertical shaft bevel gear and the magneto driving gear are made integral with the vertical driving shaft, which is carried in plain bearings in an aluminium housing. This housing is clamped to the upper half of the crank case by means of three studs. The cam-shaft carries eighteen cams, these being the inlet and exhaust cams, and a set of half compression cams which are formed with the exhaust cams and are put into action when required by means of a lever at the forward end of the cam-shaft. The cam-shaft is hollow, and serves as a channel for the conveyance of lubricating oil to each of the camshaft bearings. At the forward end of this shaft there is also mounted an air pump for maintaining pressure on the fuel supply tank, and a bevel gear tachometer drive. Lubrication of the engine is carried out by a full pressure system. The oil is pumped through a single manifold, with seven branches to the crankshaft main bearings, and then in turn through the hollow crankshaft to the connecting-rod big ends and thence through small tubes, already noted, to the small end bearings. The oil pump has four pistons and two double valves driven from a single eccentric shaft on which are mounted four eccentrics. The pump is continuously submerged in oil; in order to avoid great variations in pressure in the oil lines there is a piston operated pressure regulator, cut in between the pump and the oil lines. The two small pistons of the pump take fresh oil from a tank located in the fuselage of the machine; one of these delivers oil to the cam shaft, and one delivers to the crankshaft; this fresh oil mixes with the used oil, returns to the base, and back to the main large oil pump cylinders. By means of these small pump pistons a constant quantity of oil is kept in the motor, and the oil is continually being freshened by means of the new oil coming in. All the oil pipes are very securely fastened to the lower half of the crank case, and some cooling of the oil is effected by air passing through channels cast in the crank case on its way to the carburettor. A light steel manifold serves to connect the exhaust ports of the cylinders to the main exhaust pipe, which is inclined about 25 degrees from vertical and is arranged to give on to the atmosphere just over the top of the upper wing of the aeroplane. As regards carburation, an automatic air valve surrounds the throat of the carburettor, maintaining normal composition of mixture. A small jet is fitted for starting and running without load. The channels cast in the crank chamber, already alluded to in connection with oil-cooling, serve to warm the air before it reaches the carburettor, of which the body is water-jacketed. Ignition of the engine is by means of two Bosch ZH6 magnetos, driven at a speed of 2,175 revolutions per minute when the engine is running at its normal speed of 1,450 revolutions. The maximum advance of spark is 12 mm., or 32 degrees before the top dead centre, and the firing order of the cylinders is 1,5,3,6,2,4. The radiator fitted to this engine, together with the water-jackets, has a capacity of 25 litres of water, it is rectangular in shape, and is normally tilted at an angle of 30 degrees from vertical. Its weight is 26 kg., and it offers but slight head resistance in flight. The radial type of engine, neglected altogether in Germany, was brought to a very high state of perfection at the end of the War period by British makers. Two makes, the Cosmos Engineering Company's 'Jupiter' and 'Lucifer,' and the A.B.C. 'Wasp II' and 'Dragon Fly 1A' require special mention for their light weight and reliability on trials. The Cosmos 'Jupiter' was--for it is no longer being made--a 450 horse-power nine-cylinder radial engine, air-cooled, with the cylinders set in one single row; it was made both geared to reduce the propeller revolutions relatively to the crankshaft revolutions, and ungeared; the normal power of the geared type was 450 horse-power, and the total weight of the engine, including carburettors, magnetos, etc., was only 757 lbs.; the engine speed was 1,850 revolutions per minute, and the propeller revolutions were reduced by the gearing to 1,200. Fitted to a 'Bristol Badger' aeroplane, the total weight was 2,800 lbs., including pilot, passenger, two machine-guns, and full military load; at 7,000 feet the registered speed, with corrections for density, was 137 miles per hour; in climbing, the first 2,000 feet was accomplished in 1 minute 4 seconds; 4,000 feet was reached in 2 minutes 10 seconds; 6,000 feet was reached in 3 minutes 33 seconds, and 7,000 feet in 4 minutes 15 seconds. It was intended to modify the plane design and fit a new propeller, in order to attain even better results, but, if trials were made with these modifications, the results are not obtainable. The Cosmos 'Lucifer' was a three-cylinder radial type engine of 100 horse-power, inverted Y design, made on the simplest possible principles with a view to quantity production and extreme reliability. The rated 100 horse-power was attained at 1,600 revolutions per minute, and the cylinder dimensions were 5.75 bore by 6.25 inches stroke. The cylinders were of aluminium and steel mixture, with aluminium heads; overhead valves, operated by push rods on the front side of the cylinders, were fitted, and a simple reducing gear ran them at half engine speed. The crank case was a circular aluminium casting, the engine being attached to the fuselage of the aeroplane by a circular flange situated at the back of the case; propeller shaft and crankshaft were integral. Dual ignition was provided, the generator and distributors being driven off the back end of the engine and the distributors being easily accessible. Lubrication was by means of two pumps, one scavenging and one suction, oil being fed under pressure from the crankshaft. A single carburettor fed all three cylinders, the branch pipe from the carburettor to the circular ring being provided with an exhaust heater. The total weight of the engine, 'all on,' was 280 lbs. The A.B.C. 'Wasp II,' made by Walton Motors, Limited, is a seven-cylinder radial, air-cooled engine, the cylinders having a bore of 4.75 inches and stroke 6.25 inches. The normal brake horse-power at 1,650 revolutions is 160, and the maximum 200 at a speed of 1,850 revolutions per minute. Lubrication is by means of two rotary pumps, one feeding through the hollow crankshaft to the crank pin, giving centrifugal feed to big end and thence splash oiling, and one feeding to the nose of the engine, dropping on to the cams and forming a permanent sump for the gears on the bottom of the engine nose. Two carburettors are fitted, and two two-spark magnetos, running at one and three-quarters engine speed. The total weight of this engine is 350 lbs., or 1.75 lbs. per horse-power. Oil consumption at 1,850 revolutions is.03 pints per horse-power per hour, and petrol consumption is.56 pints per horsepower per hour. The engine thus shows as very economical in consumption, as well as very light in weight. The A.B.C. 'Dragon Fly 1A 'is a nine-cylinder radial engine having one overhead inlet and two overhead exhaust valves per cylinder. The cylinder dimensions are 5.5 inches bore by 6.5 inches stroke, and the normal rate of speed, 1,650 revolutions per minute, gives 340 horse-power. The oiling is by means of two pumps, the system being practically identical with that of the 'Wasp II.' Oil consumption is.021 pints per brake horse-power per hour, and petrol consumption.56 pints--the same as that of the 'Wasp II.' The weight of the complete engine, including propeller boss, is 600 lbs., or 1,765 lbs. per horse-power. These A.B.C. radials have proved highly satisfactory on tests, and their extreme simplicity of design and reliability commend them as engineering products and at the same time demonstrate the value, for aero work, of the air-cooled radial design--when this latter is accompanied by sound workmanship. These and the Cosmos engines represent the minimum of weight per horse-power yet attained, together with a practicable degree of reliability, in radial and probably any aero engine design. APPENDIX A GENERAL MENSIER'S REPORT ON THE TRIALS OF CLEMENT ADER'S AVION. Paris, October 21, 1897. Report on the trials of M. Clement Ader's aviation apparatus. M. Ader having notified the Minister of War by letter, July 21, 1897, that the Apparatus of Aviation which he had agreed to build under the conditions set forth in the convention of July 24th, 1894, was ready, and therefore requesting that trials be undertaken before a Committee appointed for this purpose as per the decision of August 4th, the Committee was appointed as follows:-- Division General Mensier, Chairman; Division General Delambre, Inspector General of the Permanent Works of Coast Defence, Member of the Technical Committee of the Engineering Corps; Colonel Laussedat, Director of the Conservatoire des Arts et Metiers; Sarrau, Member of the Institute, Professor of Mechanical Engineering at the Polytechnic School; Leaute, Member of the Institute, Professor of Mechanical Engineering at the Polytechnique School. Colonel Laussedat gave notice at once that his health and work as Director of the Conservatoire des Arts et Metiers did not permit him to be a member of the Committee; the Minister therefore accepted his resignation on September 24th, and decided not to replace him. Later on, however, on the request of the Chairman of the Committee, the Minister appointed a new member General Grillon, commanding the Engineer Corps of the Military Government of Paris. To carry on the trials which were to take place at the camp of Satory, the Minister ordered the Governor of the Military Forces of Paris to requisition from the Engineer Corps, on the request of the Chairman of the Committee, the men necessary to prepare the grounds at Satory. After an inspection made on the 16th an aerodrome was chosen. M. Ader's idea was to have it of circular shape with a width of 40 metres and an average diameter of 450 metres. The preliminary work, laying out the grounds, interior and exterior circumference, etc., was finished at the end of August; the work of smoothing off the grounds began September 1st with forty-five men and two rollers, and was finished on the day of the first tests, October 12th. The first meeting of the Committee was held August 18th in M. Ader's workshop; the object being to demonstrate the machine to the Committee and give all the information possible on the tests that were to be held. After a careful examination and after having heard all the explanations by the inventor which were deemed useful and necessary, the Committee decided that the apparatus seemed to be built with a perfect understanding of the purpose to be fulfilled as far as one could judge from a study of the apparatus at rest; they therefore authorised M. Ader to take the machine apart and carry it to the camp at Satory so as to proceed with the trials. By letter of August 19th the Chairman made report to the Minister of the findings of the Committee. The work on the grounds having taken longer than was anticipated, the Chairman took advantage of this delay to call the Committee together for a second meeting, during which M. Ader was to run the two propulsive screws situated at the forward end of the apparatus. The meeting was held October 2nd. It gave the Committee an opportunity to appreciate the motive power in all its details; firebox, boiler, engine, under perfect control, absolute condensation, automatic fuel and feed of the liquid to be vaporised, automatic lubrication and scavenging; everything, in a word, seemed well designed and executed. The weights in comparison with the power of the engine realised a considerable advance over anything made to date, since the two engines weighed together realised 42 kg., the firebox and boiler 60 kg., the condenser 15 kg., or a total of 117 kg. for approximately 40 horse-power or a little less than 3 kg. per horse-power. One of the members summed up the general opinion by saying: 'Whatever may be the result from an aviation point of view, a result which could not be foreseen for the moment, it was nevertheless proven that from a mechanical point of view M. Ader's apparatus was of the greatest interest and real ingeniosity. He expressed a hope that in any case the machine would not be lost to science.' The second experiment in the workshop was made in the presence of the Chairman, the purpose being to demonstrate that the wings, having a spread of 17 metres, were sufficiently strong to support the weight of the apparatus. With this object in view, 14 sliding supports were placed under each one of these, representing imperfectly the manner in which the wings would support the machine in the air; by gradually raising the supports with the slides, the wheels on which the machine rested were lifted from the ground. It was evident at that time that the members composing the skeleton of the wings supported the apparatus, and it was quite evident that when the wings were supported by the air on every point of their surface, the stress would be better equalised than when resting on a few supports, and therefore the resistance to breakage would be considerably greater. After this last test, the work on the ground being practically finished, the machine was transported to Satory, assembled and again made ready for trial. At first M. Ader was to manoeuvre the machine on the ground at a moderate speed, then increase this until it was possible to judge whether there was a tendency for the machine to rise; and it was only after M. Ader had acquired sufficient practice that a meeting of the Committee was to be called to be present at the first part of the trials; namely, volutions of the apparatus on the ground. The first test took place on Tuesday, October 12th, in the presence of the Chairman of the Committee. It had rained a good deal during the night and the clay track would have offered considerable resistance to the rolling of the machine; furthermore, a moderate wind was blowing from the south-west, too strong during the early part of the afternoon to allow of any trials. Toward sunset, however, the wind having weakened, M. Ader decided to make his first trial; the machine was taken out of its hangar, the wings were mounted and steam raised. M. Ader in his seat had, on each side of him, one man to the right and one to the left, whose duty was to rectify the direction of the apparatus in the event that the action of the rear wheel as a rudder would not be sufficient to hold the machine in a straight course. At 5.25 p.m. the machine was started, at first slowly and then at an increased speed; after 250 or 300 metres, the two men who were being dragged by the apparatus were exhausted and forced to fall flat on the ground in order to allow the wings to pass over them, and the trip around the track was completed, a total of 1,400 metres, without incident, at a fair speed, which could be estimated to be from 300 to 400 metres per minute. Notwithstanding M. Ader's inexperience, this being the first time that he had run his apparatus, he followed approximately the chalk line which marked the centre of the track and he stopped at the exact point from which he started. The marks of the wheels on the ground, which was rather soft, did not show up very much, and it was clear that a part of the weight of the apparatus had been supported by the wings, though the speed was only about one-third of what the machine could do had M. Ader used all its motive power; he was running at a pressure of from 3 to 4 atmospheres, when he could have used 10 to 12. This first trial, so fortunately accomplished, was of great importance; it was the first time that a comparatively heavy vehicle (nearly 400 kg., including the weight of the operator, fuel, and water) had been set in motion by a tractive apparatus, using the air solely as a propelling medium. The favourable report turned in by the Committee after the meeting of October 2nd was found justified by the results demonstrated on the grounds, and the first problem of aviation, namely, the creation of efficient motive power, could be considered as solved, since the propulsion of the apparatus in the air would be a great deal easier than the traction on the ground, provided that the second part of the problem, the sustaining of the machine in the air, would be realised. The next day, Wednesday the 13th, no further trials were made on account of the rain and wind. On Thursday the 14th the Chairman requested that General Grillon, who had just been appointed a member of the Committee, accompany him so as to have a second witness. The weather was fine, but a fairly strong, gusty wind was blowing from the south. M. Ader explained to the two members of the Committee the danger of these gusts, since at two points of the circumference the wind would strike him sideways. The wind was blowing in the direction A B, the apparatus starting from C, and running in the direction shown by the arrow. The first dangerous spot would be at B. The apparatus had been kept in readiness in the event of the wind dying down. Toward sunset the wind seemed to die down, as it had done on the evening of the 12th. M. Ader hesitated, which, unfortunately, further events only justified, but decided to make a new trial. At the start, which took place at 5.15 p.m., the apparatus, having the wind in the rear, seemed to run at a fairly regular speed; it was, nevertheless, easy to note from the marks of the wheels on the ground that the rear part of the apparatus had been lifted and that the rear wheel, being the rudder, had not been in constant contact with the ground. When the machine came to the neighbourhood of B, the two members of the Committee saw the machine swerve suddenly out of the track in a semicircle, lean over to the right and finally stop. They immediately proceeded to the point where the accident had taken place and endeavoured to find an explanation for the same. The Chairman finally decided as follows: M. Ader was the victim of a gust of wind which he had feared as he explained before starting out; feeling himself thrown out of his course, he tried to use the rudder energetically, but at that time the rear wheel was not in contact with the ground, and therefore did not perform its function; the canvas rudder, which had as its purpose the manoeuvring of the machine in the air, did not have sufficient action on the ground. It would have been possible without any doubt to react by using the propellers at unequal speed, but M. Ader, being still inexperienced, had not thought of this. Furthermore, he was thrown out of his course so quickly that he decided, in order to avoid a more serious accident, to stop both engines. This sudden stop produced the half-circle already described and the fall of the machine on its side. The damage to the machine was serious; consisting at first sight of the rupture of both propellers, the rear left wheel and the bending of the left wing tip. It will only be possible to determine after the machine is taken apart whether the engine, and more particularly the organs of transmission, have been put out of line. Whatever the damage may be, though comparatively easy to repair, it will take a certain amount of time, and taking into consideration the time of year it is evident that the tests will have to be adjourned for the present. As has been said in the above report, the tests, though prematurely interrupted, have shown results of great importance, and though the final results are hard to foresee, it would seem advisable to continue the trials. By waiting for the return of spring there will be plenty of time to finish the tests and it will not be necessary to rush matters, which was a partial cause of the accident. The Chairman of the Committee personally has but one hope, and that is that a decision be reached accordingly. Division General, Chairman of the Committee, Mensier. Boulogne-sur-Seine, October 21st, 1897. Annex to the Report of October 21st. General Grillon, who was present at the trials of the 14th, and who saw the report relative to what happened during that day, made the following observations in writing, which are reproduced herewith in quotation marks. The Chairman of the Committee does not agree with General Grillon and he answers these observations paragraph by paragraph. 1. 'If the rear wheel (there is only one of these) left but intermittent tracks on the ground, does that prove that the machine has a tendency to rise when running at a certain speed?' Answer.--This does not prove anything in any way, and I was very careful not to mention this in my report, this point being exactly what was needed and that was not demonstrated during the two tests made on the grounds. 'Does not this unequal pressure of the two pair of wheels on the ground show that the centre of gravity of the apparatus is placed too far forward and that under the impulse of the propellers the machine has a tendency to tilt forward, due to the resistance of the air?' Answer.--The tendency of the apparatus to rise from the rear when it was running with the wind seemed to be brought about by the effects of the wind on the huge wings, having a spread of 17 metres, and I believe that when the machine would have faced the wind the front wheels would have been lifted. During the trials of October 12th, when a complete circuit of the track was accomplished without incidents, as I and Lieut. Binet witnessed, there was practically no wind. I was therefore unable to verify whether during this circuit the two front wheels or the rear wheel were in constant contact with the ground, because when the trial was over it was dark (it was 5.30) and the next day it was impossible to see anything because it had rained during the night and during Wednesday morning. But what would prove that the rear wheel was in contact with the ground at all times is the fact that M. Ader, though inexperienced, did not swerve from the circular track, which would prove that he steered pretty well with his rear wheel--this he could not have done if he had been in the air. In the tests of the 12th, the speed was at least as great as on the 14th. 2. 'It would seem to me that if M. Ader thought that his rear wheels were off the ground he should have used his canvas rudder in order to regain his proper course; this was the best way of causing the machine to rotate, since it would have given an angular motion to the front axle.' Answer.--I state in my report that the canvas rudder whose object was the manoeuvre of the apparatus in the air could have no effect on the apparatus on the ground, and to convince oneself of this point it is only necessary to consider the small surface of this canvas rudder compared with the mass to be handled on the ground, a weight of approximately 400 kg. According to my idea, and as I have stated in my report, M. Ader should have steered by increasing the speed on one of his propellers and slowing down the other. He admitted afterward that this remark was well founded, but that he did not have time to think of it owing to the suddenness of the accident. 3. 'When the apparatus fell on its side it was under the sole influence of the wind, since M. Ader had stopped the machine. Have we not a result here which will always be the same when the machine comes to the ground, since the engines will always have to be stopped or slowed down when coming to the ground? Here seems to be a bad defect of the apparatus under trial.' Answer.--I believe that the apparatus fell on its side after coming to a stop, not on account of the wind, but because the semicircle described was on rough ground and one of the wheels had collapsed. Mensier. October 27th, 1897. APPENDIX B Specification and Claims of Wright Patent, No. 821393. Filed March 23rd, 1903. Issued May 22nd, 1906. Expires May 22nd, 1923. To all whom it may concern. Be it known that we, Orville Wright and Wilbur Wright, citizens of the United States, residing in the city of Dayton, county of Montgomery, and State of Ohio, have invented certain new and useful Improvements in Flying Machines, of which the following is a specification. Our invention relates to that class of flying-machines in which the weight is sustained by the reactions resulting when one or more aeroplanes are moved through the air edgewise at a small angle of incidence, either by the application of mechanical power or by the utilisation of the force of gravity. The objects of our invention are to provide means for maintaining or restoring the equilibrium or lateral balance of the apparatus, to provide means for guiding the machine both vertically and horizontally, and to provide a structure combining lightness, strength, convenience of construction and certain other advantages which will hereinafter appear. To these ends our invention consists in certain novel features, which we will now proceed to describe and will then particularly point out in the claims. In the accompanying drawings, Figure I 1 is a perspective view of an apparatus embodying our invention in one form. Fig. 2 is a plan view of the same, partly in horizontal section and partly broken away. Fig. 3 is a side elevation, and Figs. 4 and 5 are detail views, of one form of flexible joint for connecting the upright standards with the aeroplanes. In flying machines of the character to which this invention relates the apparatus is supported in the air by reason of the contact between the air and the under surface of one or more aeroplanes, the contact surface being presented at a small angle of incidence to the air. The relative movements of the air and aeroplane may be derived from the motion of the air in the form of wind blowing in the direction opposite to that in which the apparatus is travelling or by a combined downward and forward movement of the machine, as in starting from an elevated position or by combination of these two things, and in either case the operation is that of a soaring-machine, while power applied to the machine to propel it positively forward will cause the air to support the machine in a similar manner. In either case owing to the varying conditions to be met there are numerous disturbing forces which tend to shift the machine from the position which it should occupy to obtain the desired results. It is the chief object of our invention to provide means for remedying this difficulty, and we will now proceed to describe the construction by means of which these results are accomplished. In the accompanying drawing we have shown an apparatus embodying our invention in one form. In this illustrative embodiment the machine is shown as comprising two parallel superposed aeroplanes, 1 and 2, may be embodied in a structure having a single aeroplane. Each aeroplane is of considerably greater width from side to side than from front to rear. The four corners of the upper aeroplane are indicated by the reference letters a, b, c, and d, while the corresponding corners of the lower aeroplane 2 are indicated by the reference letters e, f, g, and h. The marginal lines ab and ef indicate the front edges of the aeroplanes, the lateral margins of the upper aeroplane are indicated, respectively, by the lines ad and bc, the lateral margins of the lower aeroplane are indicated, respectively, by the lines eh and fg, while the rear margins of the upper and lower aeroplanes are indicated, respectively, by the lines cd and gh. Before proceeding to a description of the fundamental theory of operation of the structure we will first describe the preferred mode of constructing the aeroplanes and those portions of the structure which serve to connect the two aeroplanes. Each aeroplane is formed by stretching cloth or other suitable fabric over a frame composed of two parallel transverse spars 3, extending from side to side of the machine, their ends being connected by bows 4 extending from front to rear of the machine. The front and rear spars 3 of each aeroplane are connected by a series of parallel ribs 5, which preferably extend somewhat beyond the rear spar, as shown. These spars, bows, and ribs are preferably constructed of wood having the necessary strength, combined with lightness and flexibility. Upon this framework the cloth which forms the supporting surface of the aeroplane is secured, the frame being enclosed in the cloth. The cloth for each aeroplane previous to its attachment to its frame is cut on the bias and made up into a single piece approximately the size and shape of the aeroplane, having the threads of the fabric arranged diagonally to the transverse spars and longitudinal ribs, as indicated at 6 in Fig. 2. Thus the diagonal threads of the cloth form truss systems with the spars and ribs, the threads constituting the diagonal members. A hem is formed at the rear edge of the cloth to receive a wire 7, which is connected to the ends of the rear spar and supported by the rearwardly-extending ends of the longitudinal ribs 5, thus forming a rearwardly-extending flap or portion of the aeroplane. This construction of the aeroplane gives a surface which has very great strength to withstand lateral and longitudinal strains, at the same time being capable of being bent or twisted in the manner hereinafter described. When two aeroplanes are employed, as in the construction illustrated, they are connected together by upright standards 8. These standards are substantially rigid, being preferably constructed of wood and of equal length, equally spaced along the front and rear edges of the aeroplane, to which they are connected at their top and bottom ends by hinged joints or universal joints of any suitable description. We have shown one form of connection which may be used for this purpose in Figs. 4 and 5 of the drawings. In this construction each end of the standard 8 has secured to it an eye 9 which engages with a hook 10, secured to a bracket plate 11, which latter plate is in turn fastened to the spar 3. Diagonal braces or stay-wires 12 extend from each end of each standard to the opposite ends of the adjacent standards, and as a convenient mode of attaching these parts I have shown a hook 13 made integral with the hook 10 to receive the end of one of the stay-wires, the other stay-wire being mounted on the hook 10. The hook 13 is shown as bent down to retain the stay-wire in connection to it, while the hook 10 is shown as provided with a pin 14 to hold the staywire 12 and eye 9 in position thereon. It will be seen that this construction forms a truss system which gives the whole machine great transverse rigidity and strength, while at the same time the jointed connections of the parts permit the aeroplanes to be bent or twisted in the manner which we will now proceed to describe. 15 indicates a rope or other flexible connection extending lengthwise of the front of the machine above the lower aeroplane, passing under pulleys or other suitable guides 16 at the front corners e and f of the lower aeroplane, and extending thence upward and rearward to the upper rear corners c and d, of the upper aeroplane, where they are attached, as indicated at 17. To the central portion of the rope there is connected a laterally-movable cradle 18, which forms a means for moving the rope lengthwise in one direction or the other, the cradle being movable toward either side of the machine. We have devised this cradle as a convenient means for operating the rope 15, and the machine is intended to be generally used with the operator lying face downward on the lower aeroplane, with his head to the front, so that the operator's body rests on the cradle, and the cradle can be moved laterally by the movements of the operator's body. It will be understood, however, that the rope 15 may be manipulated in any suitable manner. 19 indicates a second rope extending transversely of the machine along the rear edge of the body portion of the lower aeroplane, passing under suitable pulleys or guides 20 at the rear corners g and h of the lower aeroplane and extending thence diagonally upward to the front corners a and b of the upper aeroplane, where its ends are secured in any suitable manner, as indicated at 21. Considering the structure so far as we have now described it, and assuming that the cradle 18 be moved to the right in Figs. 1 and 2, as indicated by the arrows applied to the cradle in Fig. 1 and by the dotted lines in Fig. 2, it will be seen that that portion of the rope 15 passing under the guide pulley at the corner e and secured to the corner d will be under tension, while slack is paid out throughout the other side or half of the rope 15. The part of the rope 15 under tension exercises a downward pull upon the rear upper corner d of the structure and an upward pull upon the front lower corner e, as indicated by the arrows. This causes the corner d to move downward and the corner e to move upward. As the corner e moves upward it carries the corner a upward with it, since the intermediate standard 8 is substantially rigid and maintains an equal distance between the corners a and e at all times. Similarly, the standard 8, connecting the corners d and h, causes the corner h to move downward in unison with the corner d. Since the corner a thus moves upward and the corner h moves downward, that portion of the rope 19 connected to the corner a will be pulled upward through the pulley 20 at the corner h, and the pull thus exerted on the rope 19 will pull the corner b on the other wise of the machine downward and at the same time pull the corner g at said other side of the machine upward. This results in a downward movement of the corner b and an upward movement of the corner c. Thus it results from a lateral movement of the cradle 18 to the right in Fig. 1 that the lateral margins ad and eh at one side of the machine are moved from their normal positions in which they lie in the normal planes of their respective aeroplanes, into angular relations with said normal planes, each lateral margin on this side of the machine being raised above said normal plane at its forward end and depressed below said normal plane at its rear end, said lateral margins being thus inclined upward and forward. At the same time a reverse inclination is imparted to the lateral margins bc end fg at the other side of the machine, their inclination being downward and forward. These positions are indicated in dotted lines in Fig. 1 of the drawings. A movement of the cradle 18 in the opposite direction from its normal position will reverse the angular inclination of the lateral margins of the aeroplanes in an obvious manner. By reason of this construction it will be seen that with the particular mode of construction now under consideration it is possible to move the forward corner of the lateral edges of the aeroplane on one side of the machine either above or below the normal planes of the aeroplanes, a reverse movement of the forward corners of the lateral margins on the other side of the machine occurring simultaneously. During this operation each aeroplane is twisted or distorted around a line extending centrally across the same from the middle of one lateral margin to the middle of the other lateral margin, the twist due to the moving of the lateral margins to different angles extending across each aeroplane from side to side, so that each aeroplane surface is given a helicoidal warp or twist. We prefer this construction and mode of operation for the reason that it gives a gradually increasing angle to the body of each aeroplane from the centre longitudinal line thereof outward to the margin, thus giving a continuous surface on each side of the machine, which has a gradually increasing or decreasing angle of incidence from the centre of the machine to either side. We wish it to be understood, however, that our invention is not limited to this particular construction, since any construction whereby the angular relations of the lateral margins of the aeroplanes may be varied in opposite directions with respect to the normal planes of said aeroplanes comes within the scope of our invention. Furthermore, it should be understood that while the lateral margins of the aeroplanes move to different angular positions with respect to or above and below the normal planes of said aeroplanes, it does not necessarily follow that these movements bring the opposite lateral edges to different angles respectively above and below a horizontal plane since the normal planes of the bodies of the aeroplanes are inclined to the horizontal when the machine is in flight, said inclination being downward from front to rear, and while the forward corners on one side of the machine may be depressed below the normal planes of the bodies of the aeroplanes said depression is not necessarily sufficient to carry them below the horizontal planes passing through the rear corners on that side. Moreover, although we prefer to so construct the apparatus that the movements of the lateral margins on the opposite sides of the machine are equal in extent and opposite m direction, yet our invention is not limited to a construction producing this result, since it may be desirable under certain circumstances to move the lateral margins on one side of the machine just described without moving the lateral margins on the other side of the machine to an equal extent in the opposite direction. Turning now to the purpose of this provision for moving the lateral margins of the aeroplanes in the manner described, it should be premised that owing to various conditions of wind pressure and other causes the body of the machine is apt to become unbalanced laterally, one side tending to sink and the other side tending to rise, the machine turning around its central longitudinal axis. The provision which we have just described enables the operator to meet this difficulty and preserve the lateral balance of the machine. Assuming that for some cause that side of the machine which lies to the left of the observer in Figs. 1 and 2 has shown a tendency to drop downward, a movement of the cradle 18 to the right of said figures, as herein before assumed, will move the lateral margins of the aeroplanes in the manner already described, so that the margins ad and eh will be inclined downward and rearward, and the lateral margins bc and fg will be inclined upward and rearward with respect to the normal planes of the bodies of the aeroplanes. With the parts of the machine in this position it will be seen that the lateral margins ad and eh present a larger angle of incidence to the resisting air, while the lateral margins on the other side of the machine present a smaller angle of incidence. Owing to this fact, the side of the machine presenting the larger angle of incidence will tend to lift or move upward, and this upward movement will restore the lateral balance of the machine. When the other side of the machine tends to drop, a movement of the cradle 18 in the reverse direction will restore the machine to its normal lateral equilibrium. Of course, the same effect will be produced in the same way in the case of a machine employing only a single aeroplane. In connection with the body of the machine as thus operated we employ a vertical rudder or tail 22, so supported as to turn around a vertical axis. This rudder is supported at the rear ends on supports or arms 23, pivoted at their forward ends to the rear margins of the upper and lower aeroplanes, respectively. These supports are preferably V-shaped, as shown, so that their forward ends are comparatively widely separated, their pivots being indicated at 24. Said supports are free to swing upward at their free rear ends, as indicated in dotted lines in Fig. 3, their downward movement being limited in any suitable manner. The vertical pivots of the rudder 22 are indicated at 25, and one of these pivots has mounted thereon a sheave or pulley 26, around which passes a tiller-rope 27, the ends of which are extended out laterally and secured to the rope 19 on opposite sides of the central point of said rope. By reason of this construction the lateral shifting of the cradle 18 serves to turn the rudder to one side or the other of the line of flight. It will be observed in this connection that the construction is such that the rudder will always be so turned as to present its resisting surface on that side of the machine on which the lateral margins of the aeroplanes present the least angle of resistance. The reason of this construction is that when the lateral margins of the aeroplanes are so turned in the manner hereinbefore described as to present different angles of incidence to the atmosphere, that side presenting the largest angle of incidence, although being lifted or moved upward in the manner already described, at the same time meets with an increased resistance to its forward motion, while at the same time the other side of the machine, presenting a smaller angle of incidence, meets with less resistance to its forward motion and tends to move forward more rapidly than the retarded side. This gives the machine a tendency to turn around its vertical axis, and this tendency if not properly met will not only change the direction of the front of the machine, but will ultimately permit one side thereof to drop into a position vertically below the other side with the aero planes in vertical position, thus causing the machine to fall. The movement of the rudder, hereinbefore described, prevents this action, since it exerts a retarding influence on that side of the machine which tends to move forward too rapidly and keeps the machine with its front properly presented to the direction of flight and with its body properly balanced around its central longitudinal axis. The pivoting of the supports 23 so as to permit them to swing upward prevents injury to the rudder and its supports in case the machine alights at such an angle as to cause the rudder to strike the ground first, the parts yielding upward, as indicated in dotted lines in Fig. 3, and thus preventing injury or breakage. We wish it to be understood, however, that we do not limit ourselves to the particular description of rudder set forth, the essential being that the rudder shall be vertical and shall be so moved as to present its resisting surface on that side of the machine which offers the least resistance to the atmosphere, so as to counteract the tendency of the machine to turn around a vertical axis when the two sides thereof offer different resistances to the air. From the central portion of the front of the machine struts 28 extend horizontally forward from the lower aeroplane, and struts 29 extend downward and forward from the central portion of the upper aeroplane, their front ends being united to the struts 28, the forward extremities of which are turned up, as indicated at 30. These struts 28 and 29 form truss-skids projecting in front of the whole frame of the machine and serving to prevent the machine from rolling over forward when it alights. The struts 29 serve to brace the upper portion of the main frame and resist its tendency to move forward after the lower aeroplane has been stopped by its contact with the earth, thereby relieving the rope 19 from undue strain, for it will be understood that when the machine comes into contact with the earth, further forward movement of the lower portion thereof being suddenly arrested, the inertia of the upper portion would tend to cause it to continue to move forward if not prevented by the struts 29, and this forward movement of the upper portion would bring a very violent strain upon the rope 19, since it is fastened to the upper portion at both of its ends, while its lower portion is connected by the guides 20 to the lower portion. The struts 28 and 29 also serve to support the front or horizontal rudder, the construction of which we will now proceed to describe. The front rudder 31 is a horizontal rudder having a flexible body, the same consisting of three stiff crosspieces or sticks 32, 33, and 34, and the flexible ribs 35, connecting said cross-pieces and extending from front to rear. The frame thus provided is covered by a suitable fabric stretched over the same to form the body of the rudder. The rudder is supported from the struts 29 by means of the intermediate cross-piece 32, which is located near the centre of pressure slightly in front of a line equidistant between the front and rear edges of the rudder, the cross-piece 32 forming the pivotal axis of the rudder, so as to constitute a balanced rudder. To the front edge of the rudder there are connected springs 36 which springs are connected to the upturned ends 30 of the struts 28, the construction being such that said springs tend to resist any movement either upward or downward of the front edge of the horizontal rudder. The rear edge of the rudder lies immediately in front of the operator and may be operated by him in any suitable manner. We have shown a mechanism for this purpose comprising a roller or shaft 37, which may be grasped by the operator so as to turn the same in either direction. Bands 38 extend from the roller 37 forward to and around a similar roller or shaft 39, both rollers or shafts being supported in suitable bearings on the struts 28. The forward roller or shaft has rearwardly-extending arms 40, which are connected by links 41 with the rear edge of the rudder 31. The normal position of the rudder 31 is neutral or substantially parallel with the aeroplanes 1 and 2; but its rear edge may be moved upward or downward, so as to be above or below the normal plane of said rudder through the mechanism provided for that purpose. It will be seen that the springs 36 will resist any tendency of the forward edge of the rudder to move in either direction, so that when force is applied to the rear edge of said rudder the longitudinal ribs 35 bend, and the rudder thus presents a concave surface to the action of the wind either above or below its normal plane, said surface presenting a small angle of incidence at its forward portion and said angle of incidence rapidly increasing toward the rear. This greatly increases the efficiency of the rudder as compared with a plane surface of equal area. By regulating the pressure on the upper and lower sides of the rudder through changes of angle and curvature in the manner described a turning movement of the main structure around its transverse axis may be effected, and the course of the machine may thus be directed upward or downward at the will of the operator and the longitudinal balance thereof maintained. Contrary to the usual custom, we place the horizontal rudder in front of the aeroplanes at a negative angle and employ no horizontal tail at all. By this arrangement we obtain a forward surface which is almost entirely free from pressure under ordinary conditions of flight, but which even if not moved at all from its original position becomes an efficient lifting-surface whenever the speed of the machine is accidentally reduced very much below the normal, and thus largely counteracts that backward travel of the centre of pressure on the aeroplanes which has frequently been productive of serious injuries by causing the machine to turn downward and forward and strike the ground head-on. We are aware that a forward horizontal rudder of different construction has been used in combination with a supporting surface and a rear horizontal-rudder; but this combination was not intended to effect and does not effect the object which we obtain by the arrangement hereinbefore described. We have used the term 'aeroplane' in this specification and the appended claims to indicate the supporting surface or supporting surfaces by means of which the machine is sustained in the air, and by this term we wish to be understood as including any suitable supporting surface which normally is substantially flat, although. Of course, when constructed of cloth or other flexible fabric, as we prefer to construct them, these surfaces may receive more or less curvature from the resistance of the air, as indicated in Fig. 3. We do not wish to be understood as limiting ourselves strictly to the precise details of construction hereinbefore described and shown in the accompanying drawings, as it is obvious that these details may be modified without departing from the principles of our invention. For instance, while we prefer the construction illustrated in which each aeroplane is given a twist along its entire length in order to set its opposite lateral margins at different angles, we have already pointed out that our invention is not limited to this form of construction, since it is only necessary to move the lateral marginal portions, and where these portions alone are moved only those upright standards which support the movable portion require flexible connections at their ends. Having thus fully described our invention, what we claim as new, and desire to secure by Letters Patent, is:-- 1. In a flying machine, a normally flat aeroplane having lateral marginal portions capable of movement to different positions above or below the normal plane of the body of the aeroplane, such movement being about an axis transverse to the line of flight, whereby said lateral marginal portions may be moved to different angles relatively to the normal plane of the body of the aeroplane, so as to present to the atmosphere different angles of incidence, and means for so moving said lateral marginal portions, substantially as described. 2. In a flying machine, the combination, with two normally parallel aeroplanes, superposed the one above the other, of upright standards connecting said planes at their margins, the connections between the standards and aeroplanes at the lateral portions of the aeroplanes being by means of flexible joints, each of said aeroplanes having lateral marginal portions capable of movement to different positions above or below the normal plane of the body of the aeroplane, such movement being about an axis transverse to the line of flight, whereby said lateral marginal portions may be moved to different angles relatively to the normal plane of the body of the aeroplane, so as to present to the atmosphere different angles of incidence, the standards maintaining a fixed distance between the portions of the aeroplanes which they connect, and means for imparting such movement to the lateral marginal portions of the aeroplanes, substantially as described. 3. In a flying machine, a normally flat aeroplane having lateral marginal portions capable of movement to different positions above or below the normal plane of the body of the aeroplane, such movement being about an axis transverse to the line of flight, whereby said lateral marginal portions may be moved to different angles relatively to the normal plane of the body of the aeroplane, and also to different angles relatively to each other, so as to present to the atmosphere different angles of incidence, and means for simultaneously imparting such movement to said lateral marginal portions, substantially as described. 4. In a flying machine, the combination, with parallel superposed aeroplanes, each having lateral marginal portions capable of movement to different positions above or below the normal plane of the body of the aeroplane, such movement being about an axis transverse to the line of flight, whereby said lateral marginal portions may be moved to different angles relatively to the normal plane of the body of the aeroplane, and to different angles relatively to each other, so as to present to the atmosphere different angles of incidence, of uprights connecting said aeroplanes at their edges, the uprights connecting the lateral portions of the aeroplanes being connected with said aeroplanes by flexible joints, and means for simultaneously imparting such movement to said lateral marginal portions, the standards maintaining a fixed distance between the parts which they connect, whereby the lateral portions on the same side of the machine are moved to the same angle, substantially as described. 5. In a flying machine, an aeroplane having substantially the form of a normally flat rectangle elongated transversely to the line of flight, in combination which means for imparting to the lateral margins of said aeroplane a movement about an axis lying in the body of the aeroplane perpendicular to said lateral margins, and thereby moving said lateral margins into different angular relations to the normal plane of the body of the aeroplane, substantially as described. 6. In a flying machine, the combination, with two superposed and normally parallel aeroplanes, each having substantially the form of a normally flat rectangle elongated transversely to the line of flight, of upright standards connecting the edges of said aeroplanes to maintain their equidistance, those standards at the lateral portions of said aeroplanes being connected therewith by flexible joints, and means for simultaneously imparting to both lateral margins of both aeroplanes a movement about axes which are perpendicular to said margins and in the planes of the bodies of the respective aeroplanes, and thereby moving the lateral margins on the opposite sides of the machine into different angular relations to the normal planes of the respective aeroplanes, the margins on the same side of the machine moving to the same angle, and the margins on one side of the machine moving to an angle different from the angle to which the margins on the other side of the machine move, substantially as described. 7. In a flying machine, the combination, with an aeroplane, and means for simultaneously moving the lateral portions thereof into different angular relations to the normal plane of the body of the aeroplane and to each other, so as to present to the atmosphere different angles of incidence, of a vertical rudder, and means whereby said rudder is caused to present to the wind that side thereof nearest the side of the aeroplane having the smaller angle of incidence and offering the least resistance to the atmosphere, substantially as described. 8. In a flying machine, the combination, with two superposed and normally parallel aeroplanes, upright standards connecting the edges of said aeroplanes to maintain their equidistance, those standards at the lateral portions of said aeroplanes being connected therewith by flexible joints, and means for simultaneously moving both lateral portions of both aeroplanes into different angular relations to the normal planes of the bodies of the respective aeroplanes, the lateral portions on one side of the machine being moved to an angle different from that to which the lateral portions on the other side of the machine are moved, so as to present different angles of incidence at the two sides of the machine, of a vertical rudder, and means whereby said rudder is caused to present to the wind that side thereof nearest the side of the aeroplanes having the smaller angle of incidence and offering the least resistance to the atmosphere, substantially as described. 9. In a flying machine, an aeroplane normally flat and elongated transversely to the line of flight, in combination with means for imparting to said aeroplane a helicoidal warp around an axis transverse to the line of flight and extending centrally along the body aeroplane in the direction of the elongation aeroplane, substantially as described. 10. In a flying machine, two aeroplanes, each normally flat and elongated transversely to the line of flight, and upright standards connecting the edges of said aeroplanes to maintain their equidistance, the connections between said standards and aeroplanes being by means of flexible joints, in combination with means for simultaneously imparting to each of said aeroplanes a helicoidal warp around an axis transverse to the line of flight and extending centrally along the body of the aeroplane in the direction of the aeroplane, substantially as described. 11. In a flying machine, two aeroplanes, each normally flat and elongated transversely to the line of flight, and upright standards connecting the edges of said aeroplanes to maintain their equidistance, the connections between such standards and aeroplanes being by means of flexible joints, in combination with means for simultaneously imparting to each of said aeroplanes a helicoidal warp around an axis transverse to the line of flight and extending centrally along the body of the aeroplane in the direction of the elongation of the aeroplane, a vertical rudder, and means whereby said rudder is caused to present to the wind that side thereof nearest the side of the aeroplanes having the smaller angle of incidence and offering the least resistance to the atmosphere, substantially as described. 12. In a flying machine, the combination, with an aeroplane, of a normally flat and substantially horizontal flexible rudder, and means for curving said rudder rearwardly and upwardly or rearwardly and downwardly with respect to its normal plane, substantially as described. 13. In a flying machine, the combination, with an aeroplane, of a normally flat and substantially horizontal flexible rudder pivotally mounted on an axis transverse to the line of flight near its centre, springs resisting vertical movement of the front edge of said rudder, and means for moving the rear edge of said rudder, above or below the normal plane thereof, substantially as described. 14. A flying machine comprising superposed connected aeroplanes means for moving the opposite lateral portions of said aeroplanes to different angles to the normal planes thereof, a vertical rudder, means for moving said vertical rudder toward that side of the machine presenting the smaller angle of incidence and the least resistance to the atmosphere, and a horizontal rudder provided with means for presenting its upper or under surface to the resistance of the atmosphere, substantially as described. 15. A flying machine comprising superposed connected aeroplanes, means for moving the opposite lateral portions of said aeroplanes to different angles to the normal planes thereof, a vertical rudder, means for moving said vertical rudder toward that side of the machine presenting the smaller angle of incidence and the least resistance to the atmosphere, and a horizontal rudder provided with means for presenting its upper or under surface to the resistance of the atmosphere, said vertical rudder being located at the rear of the machine and said horizontal rudder at the front of the machine, substantially as described. 16. In a flying machine, the combination, with two superposed and connected aeroplanes, of an arm extending rearward from each aeroplane, said arms being parallel and free to swing upward at their rear ends, and a vertical rudder pivotally mounted in the rear ends of said arms, substantially as described. 17. A flying machine comprising two superposed aeroplanes, normally flat but flexible, upright standards connecting the margins of said aeroplanes, said standards being connected to said aeroplanes by universal joints, diagonal stay-wires connecting the opposite ends of the adjacent standards, a rope extending along the front edge of the lower aeroplane, passing through guides at the front corners thereof, and having its ends secured to the rear corners of the upper aeroplane, and a rope extending along the rear edge of the lower aeroplane, passing through guides at the rear corners thereof, and having its ends secured to the front corners of the upper aeroplane, substantially as described. 18. A flying machine comprising two superposed aeroplanes, normally flat but flexible, upright standards connecting the margins of said aeroplanes, said standards being connected to said aeroplanes by universal joints, diagonal stay-wires connecting the opposite ends of the adjacent standards, a rope extending along the front edge of the lower aeroplane, passing through guides at the front corners thereof, and having its ends secured to the rear corners of the upper aeroplane, and a rope extending along the rear edge of the lower aeroplane, passing through guides at the rear corners thereof, and having its ends secured to the front corners of the upper aeroplane, in combination with a vertical rudder, and a tiller-rope connecting said rudder with the rope extending along the rear edge of the lower aeroplane, substantially as described. ORVILLE WRIGHT. WILBUR WRIGHT. Witnesses: Chas. E. Taylor. E. Earle Forrer. APPENDIX C Proclamation published by the French Government on balloon ascents, 1783. NOTICE TO THE PUBLIC! PARIS, 27TH AUGUST, 1783. On the Ascent of balloons or globes in the air. The one in question has been raised in Paris this day, 27th August, 1783, at 5 p.m., in the Champ de Mars. A Discovery has been made, which the Government deems it right to make known, so that alarm be not occasioned to the people. On calculating the different weights of hot air, hydrogen gas, and common air, it has been found that a balloon filled with either of the two former will rise toward heaven till it is in equilibrium with the surrounding air, which may not happen until it has attained a great height. The first experiment was made at Annonay, in Vivarais, MM. Montgolfier, the inventors; a globe formed of canvas and paper, 105 feet in circumference, filled with heated air, reached an uncalculated height. The same experiment has just been renewed in Paris before a great crowd. A globe of taffetas or light canvas covered by elastic gum and filled with inflammable air, has risen from the Champ de Mars, and been lost to view in the clouds, being borne in a north-westerly direction. One cannot foresee where it will descend. It is proposed to repeat these experiments on a larger scale. Any one who shall see in the sky such a globe, which resembles 'la lune obscurcie,' should be aware that, far from being an alarming phenomenon, it is only a machine that cannot possibly cause any harm, and which will some day prove serviceable to the wants of society. (Signed) DE SAUVIGNY. LENOIR. 
17346	----	THE REPORT ON UNIDENTIFIED FLYING OBJECTS BY EDWARD J. RUPPELT Former Head of the Air Force Project Blue Book Published by DOUBLEDAY & COMPANY, INC. Garden City, New York Note: This work was originally Copyright ? 1956 by Edward J. Ruppelt. This book is now in the public domain because it was not renewed in a timely fashion at the US Copyright Office, as required by law at the time. Contents Foreword 1 Project Blue Book and the UFO Story 2 The Era of Confusion Begins 3 The Classics 4 Green Fireballs, Project Twinkle, Little Lights, and Grudge 5 The Dark Ages 6 The Presses Roll--The Air Force Shrugs 7 The Pentagon Rumbles 8 The Lubbock Lights, Unabridged 9 The New Project Grudge 10 Project Blue Book and the Big Build-Up 11 The Big Flap 12 The Washington Merry-Go-Round 13 Hoax or Horror? 14 Digesting the Data 15 The Radiation Story 16 The Hierarchy Ponders 17 What Are UFO's? 18 And They're Still Flying 19 Off They Go into the Wild Blue Yonder 20 Do They or Don't They? to ELIZABETH and KRIS Foreword This is a book about unidentified flying objects--UFO's--"flying saucers." It is actually more than a book; it is a report because it is the first time that anyone, either military or civilian, has brought together in one document all the facts about this fascinating subject. With the exception of the style, this report is written exactly the way I would have written it had I been officially asked to do so while I was chief of the Air Force's project for investigating UFO reports--Project Blue Book. In many instances I have left out the names of the people who reported seeing UFO's, or the names of certain people who were associated with the project, just as I would have done in an official report. For the same reason I have changed the locale in which some of the UFO sightings occurred. This is especially true in chapter fifteen, the story of how some of our atomic scientists detected radiation whenever UFO's were reported near their "UFO-detection stations." This policy of not identifying the "source," to borrow a term from military intelligence, is insisted on by the Air Force so that the people who have co-operated with them will not get any unwanted publicity. Names are considered to be "classified information." But the greatest care has been taken to make sure that the omission of names and changes in locale has in no way altered the basic facts because this report is based on the facts--all of the facts--nothing of significance has been left out. It was only after considerable deliberation that I put this report together, because it had to be told accurately, with no holds barred. I finally decided to do it for two reasons. First, there is world- wide interest in flying saucers; people want to know the facts. But more often than not these facts have been obscured by secrecy and confusion, a situation that has led to wild speculation on one end of the scale and an almost dangerously blas? attitude on the other. It is only when all of the facts are laid out that a correct evaluation can be made. Second, after spending two years investigating and analyzing UFO reports, after talking to the people who have seen UFO's-- industrialists, pilots, engineers, generals, and just the plain man- on-the-street, and after discussing the subject with many very capable scientists, I felt that I was in a position to be able to put together the complete account of the Air Force's struggle with the flying saucer. The report has been difficult to write because it involves something that doesn't officially exist. It is well known that ever since the first flying saucer was reported in June 1947 the Air Force has officially said that there is no proof that such a thing as an interplanetary spaceship exists. But what is not well known is that this conclusion is far from being unanimous among the military and their scientific advisers because of the one word, _proof_; so the UFO investigations continue. The hassle over the word "proof" boils down to one question: What constitutes proof? Does a UFO have to land at the River Entrance to the Pentagon, near the Joint Chiefs of Staff offices? Or is it proof when a ground radar station detects a UFO, sends a jet to intercept it, the jet pilot sees it, and locks on with his radar, only to have the UFO streak away at a phenomenal speed? Is it proof when a jet pilot fires at a UFO and sticks to his story even under the threat of court-martial? Does this constitute proof? The at times hotly debated answer to this question may be the answer to the question, "Do the UFO's really exist?" I'll give you the facts--all of the facts--you decide. _July_ _1955_, E. J. RUPPELT CHAPTER ONE Project Blue Book and the UFO Story In the summer of 1952 a United States Air Force F-86 jet interceptor shot at a flying saucer. This fact, like so many others that make up the full flying saucer story, has never before been told. I know the full story about flying saucers and I know that it has never before been told because I organized and was chief of the Air Force's Project Blue Book, the special project set up to investigate and analyze unidentified flying object, or UFO, reports. (UFO is the official term that I created to replace the words "flying saucers.") There is a fighter base in the United States which I used to visit frequently because, during 1951, 1952, and 1953, it got more than its share of good UFO reports. The commanding officer of the fighter group, a full colonel and command pilot, believed that UFO's were real. The colonel believed in UFO's because he had a lot of faith in his pilots--and they had chased UFO's in their F-86's. He had seen UFO's on the scopes of his radar sets, and he knew radar. The colonel's intelligence officer, a captain, didn't exactly believe that UFO's were real, but he did think that they warranted careful investigation. The logic the intelligence officer used in investigating UFO reports--and in getting answers to many of them-- made me wish many times that he worked for me on Project Blue Book. One day the intelligence officer called me at my base in Dayton, Ohio. He wanted to know if I was planning to make a trip his way soon. When I told him I expected to be in his area in about a week, he asked me to be sure to look him up. There was no special hurry, he added, but he had something very interesting to show me. When we got wind of a good story, Project Blue Book liked to start working on it at once, so I asked the intelligence officer to tell me what he had. But nothing doing. He didn't want to discuss it over the phone. He even vetoed the idea of putting it into a secret wire. Such extreme caution really stopped me, because anything can be coded and put in a wire. When I left Dayton about a week later I decided to go straight to the fighter base, planning to arrive there in midmorning. But while I was changing airlines my reservations got fouled up, and I was faced with waiting until evening to get to the base. I called the intelligence officer and told him about the mix-up. He told me to hang on right there and he would fly over and pick me up in a T-33 jet. As soon as we were in the air, on the return trip, I called the intelligence officer on the interphone and asked him what was going on. What did he have? Why all the mystery? He tried to tell me, but the interphone wasn't working too well and I couldn't understand what he was saying. Finally he told me to wait until we returned to his office and I could read the report myself. Report! If he had a UFO report why hadn't he sent it in to Project Blue Book as he usually did? We landed at the fighter base, checked in our parachutes, Mae Wests, and helmets, and drove over to his office. There were several other people in the office, and they greeted me with the usual question, "What's new on the flying saucer front?" I talked with them for a while, but was getting impatient to find out what was on the intelligence officer's mind. I was just about to ask him about the mysterious report when he took me to one side and quietly asked me not to mention it until everybody had gone. Once we were alone, the intelligence officer shut the door, went over to his safe, and dug out a big, thick report. It was the standard Air Force reporting form that is used for all intelligence reports, including UFO reports. The intelligence officer told me that this was the only existing copy. He said that he had been told to destroy all copies, but had saved one for me to read. With great curiosity, I took the report and started to read. What _had_ happened at this fighter base? About ten o'clock in the morning, one day a few weeks before, a radar near the base had picked up an unidentified target. It was an odd target in that it came in very fast--about 700 miles per hour-- and then slowed down to about 100 miles per hour. The radar showed that it was located northeast of the airfield, over a sparsely settled area. Unfortunately the radar station didn't have any height-finding equipment. The operators knew the direction of the target and its distance from the station but they didn't know its altitude. They reported the target, and two F-86's were scrambled. The radar picked up the F-86's soon after they were airborne, and had begun to direct them into the target when the target started to fade on the radarscope. At the time several of the operators thought that this fade was caused by the target's losing altitude rapidly and getting below the radar's beam. Some of the other operators thought that it was a high-flying target and that it was fading just because it was so high. In the debate which followed, the proponents of the high-flying theory won out, and the F-86's were told to go up to 40,000 feet. But before the aircraft could get to that altitude, the target had been completely lost on the radarscope. The F-86's continued to search the area at 40,000 feet, but could see nothing. After a few minutes the aircraft ground controller called the F-86's and told one to come down to 20,000 feet, the other to 5,000 feet, and continue the search. The two jets made a quick letdown, with one pilot stopping at 20,000 feet and the other heading for the deck. The second pilot, who was going down to 5,000 feet, was just beginning to pull out when he noticed a flash below and ahead of him. He flattened out his dive a little and headed toward the spot where he had seen the light. As he closed on the spot he suddenly noticed what he first thought was a weather balloon. A few seconds later he realized that it couldn't be a balloon because it was staying ahead of him. Quite an achievement for a balloon, since he had built up a lot of speed in his dive and now was flying almost straight and level at 3,000 feet and was traveling "at the Mach." Again the pilot pushed the nose of the F-86 down and started after the object. He closed fairly fast, until he came to within an estimated 1,000 yards. Now he could get a good look at the object. Although it had looked like a balloon from above, a closer view showed that it was definitely round and flat--saucer-shaped. The pilot described it as being "like a doughnut without a hole." As his rate of closure began to drop off, the pilot knew that the object was picking up speed. But he pulled in behind it and started to follow. Now he was right on the deck. About this time the pilot began to get a little worried. What should he do? He tried to call his buddy, who was flying above him somewhere in the area at 20,000 feet. He called two or three times but could get no answer. Next he tried to call the ground controller but he was too low for his radio to carry that far. Once more he tried his buddy at 20,000 feet, but again no luck. By now he had been following the object for about two minutes and during this time had closed the gap between them to approximately 500 yards. But this was only momentary. Suddenly the object began to pull away, slowly at first, then faster. The pilot, realizing that he couldn't catch _it_, wondered what to do next. When the object traveled out about 1,000 yards, the pilot suddenly made up his mind--he did the only thing that he could do to stop the UFO. It was like a David about to do battle with a Goliath, but he had to take a chance. Quickly charging his guns, he started shooting. . . . A moment later the object pulled up into a climb and in a few seconds it was gone. The pilot climbed to 10,000 feet, called the other F-86, and now was able to contact his buddy. They joined up and went back to their base. As soon as he had landed and parked, the F-86 pilot went into operations to tell his story to his squadron commander. The mere fact that he had fired his guns was enough to require a detailed report, as a matter of routine. But the circumstances under which the guns actually were fired created a major disturbance at the fighter base that day. After the squadron commander had heard his pilot's story, he called the group commander, the colonel, and the intelligence officer. They heard the pilot's story. For some obscure reason there was a "personality clash," the intelligence officer's term, between the pilot and the squadron commander. This was obvious, according to the report I was reading, because the squadron commander immediately began to tear the story apart and accuse the pilot of "cracking up," or of just "shooting his guns for the hell of it and using the wild story as a cover-up." Other pilots in the squadron, friends of the accused pilot-- including the intelligence officer and a flight surgeon--were called in to "testify." All of these men were aware of the fact that in certain instances a pilot can "flip" for no good reason, but none of them said that he had noticed any symptoms of mental crack-up in the unhappy pilot. None, except the squadron commander. He kept pounding home his idea-- that the pilot was "psycho"--and used a few examples of what the report called "minor incidents" to justify his stand. Finally the pilot who had been flying with the "accused" man was called in. He said that he had been monitoring the tactical radio channel but that he hadn't heard any calls from his buddy's low- flying F-86. The squadron commander triumphantly jumped on this point, but the accused pilot tended to refute it by admitting he was so jumpy that he might not have been on the right channel. But when he was asked if he had checked or changed channels after he had lost the object and before he had finally contacted the other F-86, he couldn't remember. So ended the pilot's story and his interrogation. The intelligence officer wrote up his report of a UFO sighting, but at the last minute, just before sending it, he was told to hold it back. He was a little unhappy about this turn of events, so he went in to see why the group commander had decided to delay sending the report to Project Blue Book. They talked over the possible reactions to the report. If it went out it would cause a lot of excitement, maybe unnecessarily. Yet, if the pilot actually had seen what he claimed, it was vitally important to get the report in to ATIC immediately. The group commander said that he would made his decision after a talk with his executive officer. They decided not to send the report and ordered it destroyed. When I finished reading, the intelligence officer's first comment was, "What do you think?" Since the evaluation of the report seemed to hinge upon conflicts between personalities I didn't know, I could venture no opinion, except that the incident made up the most fascinating UFO report I'd ever seen. So I batted the intelligence officer's question back to him. "I know the people involved," he replied, "and I don't think the pilot was nuts. I can't give you the report, because Colonel ------ told me to destroy it. But I did think you should know about it." Later he burned the report. The problems involved in this report are typical. There are certain definite facts that can be gleaned from it; the pilot did see something and he did shoot at something, but no matter how thoroughly you investigate the incident that something can never be positively identified. It might have been a hallucination or it might have been some vehicle from outer space; no one will ever know. It was a UFO. The UFO story started soon after June 24, 1947, when newspapers all over the United States carried the first flying saucer report. The story told how nine very bright, disk-shaped objects were seen by Kenneth Arnold, a Boise, Idaho, businessman, while he was flying his private plane near Mount Rainier, in the state of Washington. With journalistic license, reporters converted Arnold's description of the individual motion of each of the objects--like "a saucer skipping across water"--into "flying saucer," a name for the objects themselves. In the eight years that have passed since Arnold's memorable sighting, the term has become so common that it is now in Webster's Dictionary and is known today in most languages in the world. For a while after the Arnold sighting the term "flying saucer" was used to describe all disk-shaped objects that were seen flashing through the sky at fantastic speeds. Before long, reports were made of objects other than disks, and these were also called flying saucers. Today the words are popularly applied to anything seen in the sky that cannot be identified as a common, everyday object. Thus a flying saucer can be a formation of lights, a single light, a sphere, or any other shape; and it can be any color. Performance-wise, flying saucers can hover, go fast or slow, go high or low, turn 90- degree corners, or disappear almost instantaneously. Obviously the term "flying saucer" is misleading when applied to objects of every conceivable shape and performance. For this reason the military prefers the more general, if less colorful, name: unidentified flying objects. UFO (pronounced Yoo-foe) for short. Officially the military uses the term "flying saucer" on only two occasions. First in an explanatory sense, as when briefing people who are unacquainted with the term "UFO": "UFO--you know--flying saucers." And second in a derogatory sense, for purposes of ridicule, as when it is observed, "He says he saw a flying saucer." This second form of usage is the exclusive property of those persons who positively know that all UFO's are nonsense. Fortunately, for the sake of good manners if for no other reason, the ranks of this knowing category are constantly dwindling. One by one these people drop out, starting with the instant they see their first UFO. Some weeks after the first UFO was seen on June 24, 1947, the Air Force established a project to investigate and analyze all UFO reports. The attitude toward this task varied from a state of near panic, early in the life of the project, to that of complete contempt for anyone who even mentioned the words "flying saucer." This contemptuous attitude toward "flying saucer nuts" prevailed from mid-1949 to mid-1950. During that interval many of the people who were, or had been, associated with the project believed that the public was suffering from "war nerves." Early in 1950 the project, for all practical purposes, was closed out; at least it rated only minimum effort. Those in power now reasoned that if you didn't mention the words "flying saucers" the people would forget them and the saucers would go away. But this reasoning was false, for instead of vanishing, the UFO reports got better and better. Airline pilots, military pilots, generals, scientists, and dozens of other people were reporting UFO's, and in greater detail than in reports of the past. Radars, which were being built for air defense, began to pick up some very unusual targets, thus lending technical corroboration to the unsubstantiated claims of human observers. As a result of the continuing accumulation of more impressive UFO reports, official interest stirred. Early in 1951 verbal orders came down from Major General Charles P. Cabell, then Director of Intelligence for Headquarters, U.S. Air Force, to make a study reviewing the UFO situation for Air Force Headquarters. I had been back in the Air Force about six months when this happened. During the second world war I had been a B-29 bombardier and radar operator. I went to India, China, and later to the Pacific, with the original B-29 wing. I flew two DCF's, and some Air Medals' worth of missions, got out of the Air Force after the war, and went back to college. To keep my reserve status while I was in school, I flew as a navigator in an Air Force Reserve Troop Carrier Wing. Not long after I received my degree in aeronautical engineering, the Korean War started, and I went back on active duty. I was assigned to the Air Technical Intelligence Center at Wright-Patterson Air Force Base, in Dayton, Ohio. ATIC is responsible for keeping track of all foreign aircraft and guided missiles. ATIC also had the UFO project. I had just finished organizing a new intelligence group when General Cabell's order to review past UFO reports came down. Lieutenant Colonel Rosengarten, who received the order at ATIC, called me in and wanted to know if I'd take the job of making the review. I accepted. When the review was finished, I went to the Pentagon and presented my findings to Major General Samford, who had replaced General Cabell as Director of Intelligence. ATIC soon got the word to set up a completely new project for the investigation and analysis of UFO reports. Since I had made the review of past UFO reports I was the expert, and I got the new job. It was given the code name Project Blue Book, and I was in charge of it until late in 1953. During this time members of my staff and I traveled close to half a million miles. We investigated dozens of UFO reports, and read and analyzed several thousand more. These included every report ever received by the Air Force. For the size of the task involved Project Blue Book was always understaffed, even though I did have ten people on my regular staff plus many paid consultants representing every field of science. All of us on Project Blue Book had Top Secret security clearances so that security was no block in our investigations. Behind this organization was a reporting network made up of every Air Force base intelligence officer and every Air Force radar station in the world, and the Air Defense Command's Ground Observer Corps. This reporting net sent Project Blue Book reports on every conceivable type of UFO, by every conceivable type of person. What did these people actually see when they reported that they had observed a UFO? Putting aside truly unidentifiable flying objects for the present, this question has several answers. In many instances it has been positively proved that people have reported balloons, airplanes, stars, and many other common objects as UFO's. The people who make such reports don't recognize these common objects because something in their surroundings temporarily assumes an unfamiliar appearance. Unusual lighting conditions are a common cause of such illusions. A balloon will glow like a "ball of fire" just at sunset. Or an airplane that is not visible to the naked eye suddenly starts to reflect the sun's rays and appears to be a "silver ball." Pilots in F- 94 jet interceptors chase Venus in the daytime and fight with balloons at night, and people in Los Angeles see weird lights. On October 8, 1954, many Los Angeles newspapers and newscasters carried an item about a group of flying saucers, bright lights, flying in a V formation. The lights had been seen from many locations over Southern California. Pilots saw them while bringing their airplanes into Los Angeles International Airport, Air Force pilots flying out of Long Beach saw them, two CBS reporters in Hollywood gave an eyewitness account, and countless people called police and civil defense officials. All of them excitedly reported lights they could not identify. The next day the Air Force identified the UFO's; they were Air Force airplanes, KC-97 aerial tankers, refueling B-47 jet bombers in flight. The reason for the weird effect that startled so many Southern Californians was that when the refueling is taking place a floodlight on the bottom of the tanker airplane lights up the bomber that is being refueled. The airplanes were flying high, and slowly, so no sound was heard; only the bright floodlights could be seen. Since most people, even other pilots, have never seen a night aerial refueling operation and could not identify the odd lights they saw, the lights became UFO's. In other instances common everyday objects look like UFO's because of some odd quirk in the human mind. A star or planet that has been in the sky every day of the observer's life suddenly "takes off at high speed on a highly erratic flight path." Or a vapor trail from a high-flying jet--seen a hundred times before by the observer--becomes a flying saucer. Some psychologists explain such aberrations as being akin to the crowd behavior mechanism at work in the "bobby-sox craze." Teen-agers don't know why they squeal and swoon when their current fetish sways and croons. Yet everybody else is squealing, so they squeal too. Maybe that great comedian, Jimmy Durante, has the answer: "Everybody wants to get into the act." I am convinced that a certain percentage of UFO reports come from people who see flying saucers because others report seeing them. But this "will to see" may have deeper roots, almost religious implications, for some people. Consciously or unconsciously, they want UFO's to be real and to come from outer space. These individuals, frightened perhaps by threats of atomic destruction, or lesser fears--who knows what--act as if nothing that men can do can save the earth. Instead, they seek salvation from outer space, on the forlorn premise that flying saucer men, by their very existence, are wiser and more advanced than we. Such people may reason that a race of men capable of interplanetary travel have lived well into, or through, an atomic age. They have survived and they can tell us their secret of survival. Maybe the threat of an atomic war unified their planet and allowed them to divert their war effort to one of social and technical advancement. To such people a searchlight on a cloud or a bright star is an interplanetary spaceship. If all the UFO reports that the Air Force has received in the past eight years could be put in this "psychological quirk" category, Project Blue Book would never have been organized. It is another class of reports that causes the Air Force to remain interested in UFO's. This class of reports are called "Unknowns." In determining the identity of a UFO, the project based its method of operation on a well-known psychological premise. This premise is that to get a reaction from one of the senses there must be a stimulus. If you think you see a UFO you must have seen something. Pure hallucinations are extremely rare. For anything flying in the air the stimulus could be anything that is normally seen in the air. Balloons, airplanes, and astronomical bodies are the commoner stimuli. Birds and insects are common also, but usually are seen at such close range that they are nearly always recognized. Infrequently observed things, such as sundogs, mirages, huge fireballs, and a host of other unusual flying objects, are also known stimuli. On Project Blue Book our problem was to identify these stimuli. We had methods for checking the location, at any time, of every balloon launched anywhere in the United States. To a certain degree the same was true for airplanes. The UFO observer's estimate of where the object was located in the sky helped us to identify astronomical bodies. Huge files of UFO characteristics, along with up-to-the- minute weather data, and advice from specialists, permitted us to identify such things as sun-dogs, paper caught in updrafts, huge meteors, etc. This determination of the stimuli that triggered UFO sightings, while not an insurmountable task, was a long, tedious process. The identification of known objects was routine, and caused no excitement. The excitement and serious interest occurred when we received UFO reports in which the observer was reliable and the stimuli could not be identified. These were the reports that challenged the project and caused me to spend hours briefing top U.S. officials. These were the reports that we called "Unknowns." Of the several thousand UFO reports that the Air Force has received since 1947, some 15 to 20 per cent fall into this category called unknown. This means that the observer was not affected by any determinable psychological quirks and that after exhaustive investigation the object that was reported could not be identified. To be classed as an unknown, a UFO report also had to be "good," meaning that it had to come from a competent observer and had to contain a reasonable amount of data. Reports are often seen in the newspapers that say: "Mrs. Henry Jones, of 5464 South Elm, said that 10:00A.M. she was shaking her dust mop out of the bedroom window when she saw a flying saucer"; or "Henry Armstrong was driving between Grundy Center and Rienbeck last night when he saw a light. Henry thinks it was a flying saucer." This is not a good UFO report. This type of UFO report, if it was received by Project Blue Book, was stamped "Insufficient Data for Evaluation" and dropped into the dead file, where it became a mere statistic. Next to the "Insufficient Data" file was a file marked "C.P." This meant crackpot. Into this file went all reports from people who had talked with flying saucer crews, who had inspected flying saucers that had landed in the United States, who had ridden in flying saucers, or who were members of flying saucer crews. By Project Blue Book standards, these were not "good" UFO reports either. But here is a "good" UFO report with an "unknown" conclusion: On July 24, 1952, two Air Force colonels, flying a B-25, took off from Hamilton Air Force Base, near San Francisco, for Colorado Springs, Colorado. The day was clear, not a cloud in the sky. The colonels had crossed the Sierra Nevada between Sacramento and Reno and were flying east at 11,000 feet on "Green 3," the aerial highway to Salt Lake City. At 3:40P.M. they were over the Carson Sink area of Nevada, when one of the colonels noticed three objects ahead of them and a little to their right. The objects looked like three F- 86's flying a tight V formation. If they were F-86's they should have been lower, according to civil air regulations, but on a clear day some pilots don't watch their altitude too closely. In a matter of seconds the three aircraft were close enough to the B- 25 to be clearly seen. They were not F-86's. They were three bright silver, delta wing craft with no tails and no pilot's canopies. The only thing that broke the sharply defined, clean upper surface of the triangular wing was a definite ridge that ran from the nose to the tail. In another second the three deltas made a slight left bank and shot by the B-25 at terrific speed. The colonels estimated that the speed was at least three times that of an F-86. They got a good look at the three deltas as the unusual craft passed within 400 to 800 yards of the B-25. When they landed at Colorado Springs, the two colonels called the intelligence people at Air Defense Command Headquarters to make a UFO report. The suggestion was offered that they might have seen three F- 86's. The colonels promptly replied that if the objects had been F- 86's they would have easily been recognized as such. The colonels knew what F-86's looked like. Air Defense Command relayed the report to Project Blue Book. An investigation was started at once. Flight Service, which clears all military aircraft flights, was contacted and asked about the location of aircraft near the Carson Sink area at 3:40P.M. They had no record of the presence of aircraft in that area. Since the colonels had mentioned delta wing aircraft, and both the Air Force and the Navy had a few of this type, we double-checked. The Navy's deltas were all on the east coast, at least all of the silver ones were. A few deltas painted the traditional navy blue were on the west coast, but not near Carson Sink. The Air Force's one delta was temporarily grounded. Since balloons once in a while can appear to have an odd shape, all balloon flights were checked for both standard weather balloons and the big 100-foot-diameter research balloons. Nothing was found. A quick check on the two colonels revealed that both of them were command pilots and that each had several thousand hours of flying time. They were stationed at the Pentagon. Their highly classified assignments were such that they would be in a position to recognize _anything_ that the United States knows to be flying anywhere in the world. Both men had friends who had "seen flying saucers" at some time, but both had openly voiced their skepticism. Now, from what the colonels said when they were interviewed after landing at Colorado Springs, they had changed their opinions. Nobody knows what the two colonels saw over Carson Sink. However, it is always possible to speculate. Maybe they just thought they were close enough to the three objects to see them plainly. The objects might have been three F-86's: maybe Flight Service lost the records. It could be that the three F-86's had taken off to fly in the local area of their base but had decided to do some illegal sight-seeing. Flight Service would have no record of a flight like this. Maybe both of the colonels had hallucinations. There is a certain mathematical probability that any one of the above speculative answers is correct--correct for this one case. If you try this type of speculation on hundreds of sightings with "unknown" answers, the probability that the speculative answers are correct rapidly approaches zero. Maybe the colonels actually did see what they thought they did, a type of craft completely foreign to them. Another good UFO report provides an incident in which there is hardly room for any speculation of this type. The conclusion is more simply, "Unknown," period. On January 20, 1952, at seven-twenty in the evening, two master sergeants, both intelligence specialists, were walking down a street on the Fairchild Air Force Base, close to Spokane, Washington. Suddenly both men noticed a large, bluish-white, spherical-shaped object approaching from the east. They stopped and watched the object carefully, because several of these UFO's had been reported by pilots from the air base over the past few months. The sergeants had written up the reports on these earlier sightings. The object was traveling at a moderately fast speed on a horizontal path. As it passed to the north of their position and disappeared in the west, the sergeants noted that it had a long blue tail. At no time did they hear any sound. They noted certain landmarks that the object had crossed and estimated the time taken in passing these landmarks. The next day they went out and measured the angles between these landmarks in order to include them in their report. When we got the report at ATIC, our first reaction was that the master sergeants had seen a large meteor. From the evidence I had written off, as meteors, all previous similar UFO reports from this air base. The sergeants' report, however, contained one bit of information that completely changed the previous picture. At the time of the sighting there had been a solid 6,000-foot-thick overcast at 4,700 feet. And meteors don't go that low. A few quick calculations gave a rather fantastic answer. If the object was just at the base of the clouds it would have been 10,000 feet from the two observers and traveling 1,400 miles per hour. But regardless of the speed, the story was still fantastic. The object was no jet airplane because there was no sound. It was not a searchlight because there were none on the air base. It was not an automobile spotlight because a spotlight will not produce the type of light the sergeants described. As a double check, however, both men were questioned on this point. They stated firmly that they had seen hundreds of searchlights and spotlights playing on clouds, and that this was not what they saw. Beyond these limited possibilities the sergeants' UFO discourages fruitful speculation. The object remains unidentified. The UFO reports made by the two colonels and the two master sergeants are typical of hundreds of other good UFO reports which carry the verdict, "Conclusion unknown." Some of these UFO reports have been publicized, but many have not. Very little information pertaining to UFO's was withheld from the press--if the press knew of the occurrence of specific sightings. Our policy on releasing information was to answer only direct questions from the press. If the press didn't know about a given UFO incident, they naturally couldn't ask questions about it. Consequently such stories were never released. In other instances, when the particulars of a UFO sighting were released, they were only the bare facts about what was reported. Any additional information that might have been developed during later investigations and analyses was not released. There is a great deal of interest in UFO's and the interest shows no signs of diminishing. Since the first flying saucer skipped across the sky in the summer of 1947, thousands of words on this subject have appeared in every newspaper and most magazines in the United States. During a six-month period in 1952 alone 148 of the nation's leading newspapers carried a total of over 16,000 items about flying saucers. During July 1952 reports of flying saucers sighted over Washington, D.C., cheated the Democratic National Convention out of precious headline space. The subject of flying saucers, which has generated more unscientific behavior than any other topic of modern times, has been debated at the meetings of professional scientific societies, causing scientific tempers to flare where unemotional objectivity is supposed to reign supreme. Yet these thousands of written words and millions of spoken words-- all attesting to the general interest--have generated more heat than light. Out of this avalanche of print and talk, the full, factual, true story of UFO's has emerged only on rare occasions. The general public, for its interest in UFO's, has been paid off in misinformation. Many civilian groups must have sensed this, for while I was chief of Project Blue Book I had dozens of requests to speak on the subject of UFO's. These civilian requests had to be turned down because of security regulations. I did give many official briefings, however, behind closed doors, to certain groups associated with the government--all of them upon request. The subject of UFO's was added to a regular series of intelligence briefings given to students at the Air Force's Command and Staff School, and to classes at the Air Force's Intelligence School. I gave briefings to the technical staff at the Atomic Energy Commission's Los Alamos laboratory, where the first atomic bomb was built. The theater where this briefing took place wouldn't hold all of the people who tried to get in, so the briefing was recorded and replayed many times. The same thing happened at AEC's Sandia Base, near Albuquerque. Many groups in the Pentagon and the Office of Naval Research requested UFO briefings. Civilian groups, made up of some of the nation's top scientists and industrialists, and formed to study special military problems, worked in a UFO briefing. Top Air Force commanders were given periodic briefings. Every briefing I gave was followed by a discussion that lasted anywhere from one to four hours. In addition to these, Project Blue Book published a classified monthly report on UFO activity. Requests to be put on distribution for this report were so numerous that the distribution had to be restricted to major Air Force Command Headquarters. This interest was not caused by any revolutionary information that was revealed in the briefings or reports. It stemmed only from a desire to get the facts about an interesting subject. Many aspects of the UFO problem were covered in these official briefings. I would give details of many of the better reports we received, our conclusions about them, and how those conclusions were reached. If we had identified a UFO, the audience was told how the identification was made. If we concluded that the answer to a UFO sighting was "Unknown," the audience learned why we were convinced it was unknown. Among the better sightings that were described fully to interested government groups were: the complete story of the Lubbock Lights, including the possible sighting of the same V-shaped light formations at other locations on the same night; the story of a group of scientists who detected mysterious nuclear radiation when UFO's were sighted; and all of the facts behind such famous cases as the Mantell Incident, the Florida scoutmaster who was burned by a "flying saucer," and headline-capturing sightings at Washington, D.C. I showed them what few photographs we had, the majority of which everyone has seen, since they have been widely published in magazines and newspapers. Our collection of photographs was always a disappointment as far as positive proof was concerned because, in a sense, if you've seen one you've seen them all. We had no clear pictures of a saucer, just an assortment of blurs, blotches, and streaks of light. The briefings included a description of how Project Blue Book operated and a survey of the results of the many studies that were made of the mass of UFO data we had collected. Also covered were our interviews with a dozen North American astronomers, the story of the unexplained green fireballs of New Mexico, and an account of how a committee of six distinguished United States scientists spent many hours attempting to answer the question, "Are the UFO's from outer space?" Unfortunately the general public was never able to hear these briefings. For a long time, contrary to present thinking in military circles, I have believed that the public also is entitled to know the details of what was covered in these briefings (less, of course, the few items pertaining to radar that were classified "Secret," and the names of certain people). But withholding these will not alter the facts in any way. A lot has already been written on the subject of UFO's, but none of it presents the true, complete story. Previous forays into the UFO field have been based on inadequate information and have been warped to fit the personal biases of the individual writers. Well meaning though these authors may be, the degree to which their books have misinformed the public is incalculable. It is high time that we let the people know. The following chapters present the true and complete UFO story, based on what I learned about UFO's while I was chief of Project Blue Book, the Air Force's project for the investigation and analysis of UFO reports. Here is the same information that I gave to Secretary of the Air Force, Thomas K. Finletter, to the Air Force commanders, to scientists and industrialists. This is what the Air Force knows about unidentified flying objects. You may not agree with some of the official ideas or conclusions-- neither did a lot of people I briefed--but this is the story. CHAPTER TWO The Era of Confusion Begins On September 23, 1947, the chief of the Air Technical Intelligence Center, one of the Air Force's most highly specialized intelligence units, sent a letter to the Commanding General of the then Army Air Forces. The letter was in answer to the Commanding General's verbal request to make a preliminary study of the reports of unidentified flying objects. The letter said that after a preliminary study of UFO reports, ATIC concluded that, to quote from the letter, "the reported phenomena were real." The letter strongly urged that a permanent project be established at ATIC to investigate and analyze future UFO reports. It requested a priority for the project, a registered code name, and an over-all security classification. ATICs request was granted and Project Sign, the forerunner of Project Grudge and Project Blue Book, was launched. It was given a 2A priority, 1A being the highest priority an Air Force project could have. With this the Air Force dipped into the most prolonged and widespread controversy it has ever, or may ever, encounter. The Air Force grabbed the proverbial bear by the tail and to this day it hasn't been able to let loose. The letter to the Commanding General of the Army Air Forces from the chief of ATIC had used the word "phenomena." History has shown that this was not a too well-chosen word. But on September 23, 1947, when the letter was written, ATICs intelligence specialists were confident that within a few months or a year they would have the answer to the question, "What are UFO's?" The question, "Do UFO's exist?" was never mentioned. The only problem that confronted the people at ATIC was, "Were the UFO's of Russian or interplanetary origin?" Either case called for a serious, secrecy-shrouded project. Only top people at ATIC were assigned to Project Sign. Although a formal project for UFO investigation wasn't set up until September 1947, the Air Force had been vitally interested in UFO reports ever since June 24, 1947, the day Kenneth Arnold made the original UFO report. As Arnold's story of what he saw that day has been handed down by the bards of saucerism, the true facts have been warped, twisted, and changed. Even some points in Arnold's own account of his sighting as published in his book, _The_ _Coming_ _of_ _the_ _Saucers_, do not jibe with what the official files say he told the Air Force in 1947. Since this incident was the original UFO sighting, I used to get many inquiries about it from the press and at briefings. To get the true and accurate story of what did happen to Kenneth Arnold on June 24, 1947, I had to go back through old newspaper files, official reports, and talk to people who had worked on Project Sign. By cross-checking these data and talking to people who had heard Arnold tell about his UFO sighting soon after it happened, I finally came up with what I believe is the accurate story. Arnold had taken off from Chehalis, Washington, intending to fly to Yakima, Washington. About 3:00P.M. he arrived in the vicinity of Mount Rainier. There was a Marine Corps C-46 transport plane lost in the Mount Rainier area, so Arnold decided to fly around awhile and look for it. He was looking down at the ground when suddenly he noticed a series of bright flashes off to his left. He looked for the source of the flashes and saw a string of nine very bright disk- shaped objects, which he estimated to be 45 to 50 feet in length. They were traveling from north to south across the nose of his airplane. They were flying in a reversed echelon (i.e., lead object high with the rest stepped down), and as they flew along they weaved in and out between the mountain peaks, once passing behind one of the peaks. Each individual object had a skipping motion described by Arnold as a "saucer skipping across water." During the time that the objects were in sight, Arnold had clocked their speed. He had marked his position and their position on the map and again noted the time. When he landed he sketched in the flight path that the objects had flown and computed their speed, almost 1,700 miles per hour. He estimated that they had been 20 to 25 miles away and had traveled 47 miles in 102 seconds. I found that there was a lot of speculation on this report. Two factions at ATIC had joined up behind two lines of reasoning. One side said that Arnold had seen plain, everyday jet airplanes flying in formation. This side's argument was based on the physical limitations of the human eye, visual acuity, the eye's ability to see a small, distant object. Tests, they showed, had proved that a person with normal vision can't "see" an object that subtends an angle of less than 0.2 second of arc. For example, a basketball can't be seen at a distance of several miles but if you move the basketball closer and closer, at some point you will be able to see it. At this point the angle between the top and bottom of the ball and your eye will be about 0.2 of a second of arc. This was applied to Arnold's sighting. The "Arnold-saw-airplanes" faction maintained that since Arnold said that the objects were 45 to 50 feet long they would have had to be much closer than he had estimated or he couldn't even have seen them at all. Since they were much closer than he estimated, Arnold's timed speed was all wrong and instead of going 1,700 miles per hour the objects were traveling at a speed closer to 400 miles per hour, the speed of a jet. There was no reason to believe they weren't jets. The jets appeared to have a skipping motion because Arnold had looked at them through layers of warm and cold air, like heat waves coming from a hot pavement that cause an object to shimmer. The other side didn't buy this idea at all. They based their argument on the fact that Arnold knew where the objects were when he timed them. After all, he was an old mountain pilot and was as familiar with the area around the Cascade Mountains as he was with his own living room. To cinch this point the fact that the objects had passed _behind_ a mountain peak was brought up. This positively established the distance the objects were from Arnold and confirmed his calculated 1,700-miles-per-hour speed. Besides, no airplane can weave in and out between mountain peaks in the short time that Arnold was watching them. The visual acuity factor only strengthened the "Arnold-saw-a- flying-saucer" faction's theory that what he'd seen was a spaceship. If he could see the objects 20 to 25 miles away, they must have been about 210 feet long instead of the poorly estimated 45 to 50 feet. In 1947 this was a fantastic story, but now it is just another UFO report marked "Unknown." It is typical in that if the facts are accurate, if Arnold actually did see the UFO's go _behind_ a mountain peak, and if he knew his exact position at the time, the UFO problem cannot be lightly sloughed off; but there are always "ifs" in UFO reports. This is the type of report that led Major General John A. Samford, Director of Intelligence for Headquarters, Air Force, to make the following comment during a press conference in July 1952: "However, there have remained a percentage of this total [of all UFO reports received by the Air Force], about 20 per cent of the reports, that have come from credible observers of relatively incredible things. We keep on being concerned about them." In warping, twisting, and changing the Arnold incident, the writers of saucer lore haven't been content to confine themselves to the incident itself; they have dragged in the crashed Marine Corps' C-46. They intimate that the same flying saucers that Arnold saw shot down the C-46, grabbed up the bodies of the passengers and crew, and now have them pickled at the University of Venus Medical School. As proof they apply the same illogical reasoning that they apply to most everything. The military never released photos of the bodies of the dead men, therefore there were no bodies. There were photographs and there were bodies. In consideration of the families of air crewmen and passengers, photos of air crashes showing dead bodies are never released. Arnold himself seems to be the reason for a lot of the excitement that heralded flying saucers. Stories of odd incidents that occur in this world are continually being reported by newspapers, but never on the scale of the first UFO report. Occasional stories of the "Himalayan snowmen," or the "Malayan monsters," rate only a few inches or a column on the back pages of newspapers. Arnold's story, if it didn't make the headlines, at least made the front page. I had the reason for this explained to me one day when I was investigating a series of UFO reports in California in the spring of 1952. I was making my headquarters at an air base where a fighter-bomber wing was stationed. Through a mutual friend I met one of the fighter- bomber pilots who had known Arnold. In civilian life the pilot was a newspaper reporter and had worked on the original Arnold story. He told me that when the story first broke all the newspaper editors in the area were thoroughly convinced that the incident was a hoax, and that they intended to write the story as such. The more they dug into the facts, however, and into Arnold's reputation, the more it appeared that he was telling the truth. Besides having an unquestionable character, he was an excellent mountain pilot, and mountain pilots are a breed of men who know every nook and cranny of the mountains in their area. The most fantastic part of Arnold's story had been the 1,700-miles-per-hour speed computed from Arnold's timing the objects between two landmarks. "When Arnold told us how he computed the speed," my chance acquaintance told me, "we all put a lot of faith in his story." He went on to say that when the editors found out that they were wrong about the hoax, they did a complete about-face, and were very much impressed by the story. This enthusiasm spread, and since the Air Force so quickly denied ownership of the objects, all of the facts built up into a story so unique that papers all over the world gave it front-page space. There was an old theory that maybe Arnold had seen wind whipping snow along the mountain ridges, so I asked about this. I got a flat "Impossible." My expert on the early Arnold era said, "I've lived in the Pacific Northwest many years and have flown in the area for hundreds of hours. It's impossible to get powder snow low in the mountains in June. Personally, I believe Arnold saw some kind of aircraft and they weren't from this earth." He went on to tell me about two other very similar sightings that had happened the day after Arnold saw the nine disks. He knew the people who made these sightings and said that they weren't the kind to go off "half cocked." He offered to get a T-6 and fly me up to Boise to talk to them since they had never made a report to the military, but I had to return to Dayton so I declined. Within a few days of Arnold's sighting, others began to come in. On June 28 an Air Force pilot in an F-51 was flying near Lake Mead, Nevada, when he saw a formation of five or six circular objects off his right wing. This was about three-fifteen in the afternoon. That night at nine-twenty, four Air Force officers, two pilots, and two intelligence officers from Maxwell AFB in Montgomery, Alabama, saw a bright light traveling across the sky. It was first seen just above the horizon, and as it traveled toward the observers it "zigzagged," with bursts of high speed. When it was directly overhead it made a sharp 90-degree turn and was lost from view as it traveled south. Other reports came in. In Milwaukee a lady saw ten go over her house "like blue blazes," heading south. A school bus driver in Clarion, Iowa, saw an object streak across the sky. In a few seconds twelve more followed the first one. White Sands Proving Ground in New Mexico chalked up the first of the many sightings that this location would produce when several people riding in an automobile saw a pulsating light travel from horizon to horizon in thirty seconds. A Chicago housewife saw one "with legs." The week of July 4, 1947, set a record for reports that was not broken until 1952. The center of activity was the Portland, Oregon, area. At 11:00A.M. a carload of people driving near Redmond saw four disk-shaped objects streaking past Mount Jefferson. At 1:05P.M. a policeman was in the parking lot behind the Portland City Police Headquarters when he noticed some pigeons suddenly began to flutter around as if they were scared. He looked up and saw five large disk- shaped objects, two going south and three going east. They were traveling at a high rate of speed and seemed to be oscillating about their lateral axis. Minutes later two other policemen, both ex- pilots, reported three of the same things flying in trail. Before long the harbor patrol called into headquarters. A crew of four patrolmen had seen three to six of the disks, "shaped like chrome hub caps," traveling very fast. They also oscillated as they flew. Then the citizens of Portland began to see them. A man saw one going east and two going north. At four-thirty a woman called in and had just seen one that looked like "a new dime flipping around." Another man reported two, one going southeast, one northeast. From Milwaukie, Oregon, three were reported going northwest. In Vancouver, Washington, sheriff's deputies saw twenty to thirty. The first photo was taken on July 4 in Seattle. After much publicity it turned out to be a weather balloon. That night a United Airlines crew flying near Emmett, Idaho, saw five. The pilot's report read: Five "somethings," which were thin and smooth on the bottom and rough-appearing on top, were seen silhouetted against the sunset shortly after the plane took off from Boise at 8:04P.M. We saw them clearly. We followed them in a northeasterly direction for about 45 miles. They finally disappeared. We were unable to tell whether they outsped us or disintegrated. We can't say whether they were "smearlike," oval, or anything else but whatever they were they were not aircraft, clouds or smoke. Civilians did not have a corner on the market. On July 6 a staff sergeant in Birmingham, Alabama, saw several "dim, glowing lights" speeding across the sky and photographed one of them. Also on the sixth the crew of an Air Force B-25 saw a bright, disk-shaped object "low at nine o'clock." This is one of the few reports of an object lower than the aircraft. At Fairfield-Suisun AFB in California a pilot saw something travel three quarters of the way across the sky in a few seconds. It, too, was oscillating on its lateral axis. According to the old hands at ATIC, the first sighting that really made the Air Force take a deep interest in UFO's occurred on July 8 at Muroc Air Base (now Edwards AFB), the supersecret Air Force test center in the Mojave Desert of California. At 10:10A.M. a test pilot was running up the engine of the then new XP-84 in preparation for a test flight. He happened to look up and to the north he saw what first appeared to be a weather balloon traveling in a westerly direction. After watching it a few seconds, he changed his mind. He had been briefed on the high-altitude winds, and the object he saw was going against the wind. Had it been the size of a normal aircraft, the test pilot estimated that it would have been at 10,000 to 12,000 feet and traveling 200 to 225 miles per hour. He described the object as being spherically shaped and yellowish white in color. Ten minutes before this several other officers and airmen had seen three objects. They were similar except they had more of a silver color. They were also heading in a westerly direction. Two hours later a crew of technicians on Rogers Dry Lake, adjacent to Muroc Air Base, observed another UFO. Their report went as follows: On the 8 July 1947 at 11:50 we were sitting in an observation truck located in Area #3, Rogers Dry Lake. We were gazing upward toward a formation of two P-82's and an A-26 aircraft flying at 20,000 feet. They were preparing to carry out a seat-ejection experiment. We observed a round object, white aluminum color, which at first resembled a parachute canopy. Our first impression was that a premature ejection of the seat and dummy had occurred but this was not the case. The object was lower than 20,000 feet, and was falling at three times the rate observed for the test parachute, which ejected thirty seconds after we first saw the object. As the object fell it drifted slightly north of due west against the prevailing wind. The speed, horizontal motion, could not be determined, but it appeared to be slower than the maximum velocity F-80 aircraft. As this object descended through a low enough level to permit observation of its lateral silhouette, it presented a distinct oval- shaped outline, with two projections on the upper surface which might have been thick fins or nobs. These crossed each other at intervals, suggesting either rotation or oscillation of slow type. No smoke, flames, propeller arcs, engine noise, or other plausible or visible means of propulsion were noted. The color was silver, resembling an aluminum-painted fabric, and did not appear as dense as a parachute canopy. When the object dropped to a level such that it came into line of vision of the mountain tops, it was lost to the vision of the observers. It is estimated that the object was in sight about 90 seconds. Of the five people sitting in the observation truck, four observed this object. The following is our opinion about this object: It was man-made, as evidenced by the outline and functional appearance. Seeing this was not a hallucination or other fancies of sense. Exactly four hours later the pilot of an F-51 was flying at 20,000 feet about 40 miles south of Muroc Air Base when he sighted a "flat object of a light-reflecting nature." He reported that it had no vertical fin or wings. When he first saw it, the object was above him and he tried to climb up to it, but his F-51 would not climb high enough. All air bases in the area were contacted but they had no aircraft in the area. By the end of July 1947 the UFO security lid was down tight. The few members of the press who did inquire about what the Air Force was doing got the same treatment that you would get today if you inquired about the number of thermonuclear weapons stock-piled in the U.S.'s atomic arsenal. No one, outside of a few high-ranking officers in the Pentagon, knew what the people in the barbed-wire enclosed Quonset huts that housed the Air Technical Intelligence Center were thinking or doing. The memos and correspondence that Project Blue Book inherited from the old UFO projects told the story of the early flying saucer era. These memos and pieces of correspondence showed that the UFO situation was considered to be serious; in fact, very serious. The paper work of that period also indicated the confusion that surrounded the investigation; confusion almost to the point of panic. The brass wanted an answer, quickly, and people were taking off in all directions. Everyone's theory was as good as the next and each person with any weight at ATIC was plugging and investigating his own theory. The ideas as to the origin of the UFO's fell into two main categories, earthly and non-earthly. In the earthly category the Russians led, with the U.S. Navy and their XF-5-U-1, the "Flying Flapjack," pulling a not too close second. The desire to cover all leads was graphically pointed up to be a personal handwritten note I found in a file. It was from ATIC's chief to a civilian intelligence specialist. It said, "Are you positive that the Navy junked the XF-5- U-1 project?" The non-earthly category ran the gamut of theories, with space animals trailing interplanetary craft about the same distance the Navy was behind the Russians. This confused speculating lasted only a few weeks. Then the investigation narrowed down to the Soviets and took off on a much more methodical course of action. When World War II ended, the Germans had several radical types of aircraft and guided missiles under development. The majority of these projects were in the most preliminary stages but they were the only known craft that could even approach the performance of the objects reported by UFO observers. Like the Allies, after World War II the Soviets had obtained complete sets of data on the latest German developments. This, coupled with rumors that the Soviets were frantically developing the German ideas, caused no small degree of alarm. As more UFO's were observed near the Air Force's Muroc Test Center, the Army's White Sands Proving Ground, and atomic bomb plants, ATIC's efforts became more concentrated. Wires were sent to intelligence agents in Germany requesting that they find out exactly how much progress had been made on the various German projects. The last possibility, of course, was that the Soviets had discovered some completely new aerodynamic concept that would give saucer performance. While ATIC technical analysts were scouring the United States for data on the German projects and the intelligence agents in Germany were seeking out the data they had been asked for, UFO reports continued to flood the country. The Pacific Northwest still led with the most sightings, but every state in the Union was reporting a few flying saucers. At first there was no co-ordinated effort to collect data on the UFO reports. Leads would come from radio reports or newspaper items. Military intelligence agencies outside of ATIC were hesitant to investigate on their own initiative because, as is so typical of the military, they lacked specific orders. When no orders were forthcoming, they took this to mean that the military had no interest in the UFO's. But before long this placid attitude changed, and changed drastically. Classified orders came down to investigate _all_ UFO sightings. Get every detail and send it direct to ATIC at Wright Field. The order carried no explanation as to why the information was wanted. This lack of an explanation and the fact that the information was to be sent directly to a high-powered intelligence group within Air Force Headquarters stirred the imagination of every potential cloak-and-dagger man in the military intelligence system. Intelligence people in the field who had previously been free with opinions now clammed up tight. The era of confusion was progressing. Early statements to the press, which shaped the opinion of the public, didn't reduce the confusion factor. While ATIC was grimly expending maximum effort in a serious study, "certain high-placed officials" were officially chuckling at the mention of UFO's. In July 1947 an International News Service wire story quoted the public relations officer at Wright Field as saying, "So far we haven't found anything to confirm that saucers exist. We don't think they are guided missiles." He went on to say, "As things are now, they appear to be either a phenomenon or a figment of somebody's imagination." A few weeks later a lieutenant colonel who was Assistant to the Chief of Staff of the Fourth Air Force was widely quoted as saying, "There is no basis for belief in flying saucers in the Tacoma area [referring to a UFO sighting in the area of Tacoma, Washington], or any other area." The "experts," in their stories of saucer lore, have said that these brush-offs of the UFO sightings were intentional smoke screens to cover the facts by adding confusion. This is not true; it was merely a lack of coordination. But had the Air Force tried to throw up a screen of confusion, they couldn't have done a better job. When the lieutenant colonel from the Fourth Air Force made his widely publicized denunciation of saucer believers he specifically mentioned a UFO report from the Tacoma, Washington, area. The report of the investigation of this incident, the Maury Island Mystery, was one of the most detailed reports of the early UFO era. The report that we had in our files had been pieced together by Air Force Intelligence and other agencies because the two intelligence officers who started the investigation couldn't finish it. They were dead. For the Air Force the story started on July 31, 1947, when Lieutenant Frank Brown, an intelligence agent at Hamilton AFB, California, received a long-distance phone call. The caller was a man whom 111 call Simpson, who had met Brown when Brown investigated an earlier UFO sighting, and he had a hot lead on another UFO incident. He had just talked to two Tacoma Harbor patrolmen. One of them had seen six UFO's hover over his patrol boat and spew out chunks of odd metal. Simpson had some of the pieces of the metal. The story sounded good to Lieutenant Brown, so he reported it to his chief. His chief OK'd a trip and within an hour Lieutenant Brown and Captain Davidson were flying to Tacoma in an Air Force B-25. When they arrived they met Simpson and an airline pilot friend of his in Simpson's hotel room. After the usual round of introductions Simpson told Brown and Davidson that he had received a letter from a Chicago publisher asking him, Simpson, to investigate this case. The publisher had paid him $200 and wanted an exclusive on the story, but things were getting too hot, Simpson wanted the military to take over. Simpson went on to say that he had heard about the experience off Maury Island but that he wanted Brown and Davidson to hear it firsthand. He had called the two harbor patrolmen and they were on their way to the hotel. They arrived and they told their story. I'll call these two men Jackson and Richards although these aren't their real names. In June 1947, Jackson said, his crew, his son, and the son's dog were on his patrol boat patrolling near Maury Island, an island in Puget Sound, about 3 miles from Tacoma. It was a gray day, with a solid cloud deck down at about 2,500 feet. Suddenly everyone on the boat noticed six "doughnut-shaped" objects, just under the clouds, headed toward the boat. They came closer and closer, and when they were about 500 feet over the boat they stopped. One of the doughnut-shaped objects seemed to be in trouble as the other five were hovering around it. They were close, and everybody got a good look. The UFO's were about 100 feet in diameter, with the "hole in the doughnut" being about 25 feet in diameter. They were a silver color and made absolutely no noise. Each object had large portholes around the edge. As the five UFO's circled the sixth, Jackson recalled, one of them came in and appeared to make contact with the disabled craft. The two objects maintained contact for a few minutes, then began to separate. While this was going on, Jackson was taking photos. Just as they began to separate, there was a dull "thud" and the next second the UFO began to spew out sheets of very light metal from the hole in the center. As these were fluttering to the water, the UFO began to throw out a harder, rocklike material. Some of it landed on the beach of Maury Island. Jackson took his crew and headed toward the beach of Maury Island, but not before the boat was damaged, his son's arm had been injured, and the dog killed. As they reached the island they looked up and saw that the UFO's were leaving the area at high speed. The harbor patrolman went on to tell how he scooped up several chunks of the metal from the beach and boarded the patrol boat. He tried to use his radio to summon aid, but for some unusual reason the interference was so bad he couldn't even call the three miles to his headquarters in Tacoma. When they docked at Tacoma, Jackson got first aid for his son and then reported to his superior officer, Richards, who, Jackson added to his story, didn't believe the tale. He didn't believe it until he went out to the island himself and saw the metal. Jackson's trouble wasn't over. The next morning a mysterious visitor told Jackson to forget what he'd seen. Later that same day the photos were developed. They showed the six objects, but the film was badly spotted and fogged, as if the film had been exposed to some kind of radiation. Then Simpson told about his brush with mysterious callers. He said that Jackson was not alone as far as mysterious callers were concerned, the Tacoma newspapers had been getting calls from an anonymous tipster telling exactly what was going on in Simpson's hotel room. This was a very curious situation because no one except Simpson, the airline pilot, and the two harbor patrolmen knew what was taking place. The room had even been thoroughly searched for hidden microphones. That is the way the story stood a few hours after Lieutenant Brown and Captain Davidson arrived in Tacoma. After asking Jackson and Richards a few questions, the two intelligence agents left, reluctant even to take any of the fragments. As some writers who have since written about this incident have said, Brown and Davidson seemed to be anxious to leave and afraid to touch the fragments of the UFO, as if they knew something more about them. The two officers went to McChord AFB, near Tacoma, where their B-25 was parked, held a conference with the intelligence officer at McChord, and took off for their home base, Hamilton. When they left McChord they had a good idea as to the identity of the UFO's. Fortunately they told the McChord intelligence officer what they had determined from their interview. In a few hours the two officers were dead. The B-25 crashed near Kelso, Washington. The crew chief and a passenger had parachuted to safety. The newspapers hinted that the airplane was sabotaged and that it was carrying highly classified material. Authorities at McChord AFB confirmed this latter point, the airplane was carrying classified material. In a few days the newspaper publicity on the crash died down, and the Maury Island Mystery was never publicly solved. Later reports say that the two harbor patrolmen mysteriously disappeared soon after the fatal crash. They should have disappeared, into Puget Sound. The whole Maury Island Mystery was a hoax. The first, possibly the second-best, and the dirtiest hoax in the UFO history. One passage in the detailed official report of the Maury Island Mystery says: Both ------ (the two harbor patrolmen) admitted that the rock fragments had nothing to do with flying saucers. The whole thing was a hoax. They had sent in the rock fragments [to a magazine publisher] as a joke. ------ One of the patrolmen wrote to ------ [the publisher] stating that the rock could have been part of a flying saucer. He had said the rock came from a flying saucer because that's what ------ [the publisher] wanted him to say. The publisher, mentioned above, who, one of the two hoaxers said, wanted him to say that the rock fragments had come from a flying saucer, is the same one who paid the man I called Simpson $200 to investigate the case. The report goes on to explain more details of the incident. Neither one of the two men could ever produce the photos. They "misplaced" them, they said. One of them, I forget which, was the mysterious informer who called the newspapers to report the conversations that were going on in the hotel room. Jackson's mysterious visitor didn't exist. Neither of the men was a harbor patrolman, they merely owned a couple of beat-up old boats that they used to salvage floating lumber from Puget Sound. The airplane crash was one of those unfortunate things. An engine caught on fire, burned off, and just before the two pilots could get out, the wing and tail tore off, making it impossible for them to escape. The two dead officers from Hamilton AFB smelled a hoax, accounting for their short interview and hesitancy in bothering to take the "fragments." They confirmed their convictions when they talked to the intelligence officer at McChord. It had already been established, through an informer, that the fragments were what Brown and Davidson thought, slag. The classified material on the B-25 was a file of reports the two officers offered to take back to Hamilton and had nothing to do with the Maury Island Mystery, or better, the Maury Island Hoax. Simpson and his airline pilot friend weren't told about the hoax for one reason. As soon as it was discovered that they had been "taken," thoroughly, and were not a party to the hoax, no one wanted to embarrass them. The majority of the writers of saucer lore have played this sighting to the hilt, pointing out as their main premise the fact that the story must be true because the government never openly exposed or prosecuted either of the two hoaxers. This is a logical premise, but a false one. The reason for the thorough investigation of the Maury Island Hoax was that the government had thought seriously of prosecuting the men. At the last minute it was decided, after talking to the two men, that the hoax was a harmless joke that had mushroomed, and that the loss of two lives and a B-25 could not be directly blamed on the two men. The story wasn't even printed because at the time of the incident, even though in this case the press knew about it, the facts were classed as evidence. By the time the facts were released they were yesterday's news. And nothing is deader than yesterday's news. As 1947 drew to a close, the Air Force's Project Sign had outgrown its initial panic and had settled down to a routine operation. Every intelligence report dealing with the Germans' World War II aeronautical research had been studied to find out if the Russians could have developed any of the late German designs into flying saucers. Aerodynamicists at ATIC and at Wright Field's Aircraft Laboratory computed the maximum performance that could be expected from the German designs. The designers of the aircraft themselves were contacted. "Could the Russians develop a flying saucer from their designs?" The answer was, "No, there was no conceivable way any aircraft could perform that would match the reported maneuvers of the UFO's." The Air Force's Aeromedical Laboratory concurred. If the aircraft could be built, the human body couldn't stand the violent maneuvers that were reported. The aircraft-structures people seconded this, no material known could stand the loads of the reported maneuvers and heat of the high speeds. Still convinced that the UFO's were real objects, the people at ATIC began to change their thinking. Those who were convinced that the UFO's were of Soviet origin now began to eye outer space, not because there was any evidence that the UFO's did come from outer space but because they were convinced that UFO's existed and only some unknown race with a highly developed state of technology could build such vehicles. As far as the effect on the human body was concerned, why couldn't these people, whoever they might be, stand these horrible maneuver forces? Why judge them by earthly standards? I found a memo to this effect was in the old Project Sign files. Project Sign ended 1947 with a new problem. How do you collect interplanetary intelligence? During World War II the organization that was ATIC's forerunner, the Air Materiel Command's secret "T-2," had developed highly effective means of wringing out every possible bit of information about the technical aspects of enemy aircraft. ATIC knew these methods, but how could this be applied to spaceships? The problem was tackled with organized confusion. If the confusion in the minds of Air Force people was organized the confusion in the minds of the public was not. Publicized statements regarding the UFO were conflicting. A widely printed newspaper release, quoting an unnamed Air Force official in the Pentagon, said: The "flying saucers" are one of three things: Solar reflections on low-hanging clouds. Small meteors that break up, their crystals catching the rays of the sun. Icing conditions could have formed large hailstones and they might have flattened out and glided. A follow-up, which quoted several scientists, said in essence that the unnamed Air Force official was crazy. Nobody even heard of crystallized meteors, or huge, flat hailstones, and the solar- reflection theory was absurd. _Life_, _Time_, _Newsweek_, and many other news magazines carried articles about the UFO's. Some were written with tongue in cheek, others were not. All the articles mentioned the Air Force's mass- hysterical induced hallucinations. But a Veterans' Administration psychiatrist publicly pooh-poohed this. "Too many people are seeing things," he said. It was widely suggested that all the UFO's were meteors. Two Chicago astronomers queered this. Dr. Gerard Kuiper, director of the University of Chicago observatory, was quoted as flatly saying the UFO's couldn't be meteors. "They are probably man-made," he told the Associated Press. Dr. Oliver Lee, director of Northwestern University's observatory, agreed with Dr. Kuiper and he threw in an additional confusion factor that had been in the back of many people's minds. Maybe they were our own aircraft. The government had been denying that UFO's belonged to the U.S. from the first, but Dr. Vannevar Bush, the world-famous scientist, and Dr. Merle Tuve, inventor of the proximity fuse, added their weight. "Impossible," they said. All of this time unnamed Air Force officials were disclaiming serious interest in the UFO subject. Yet every time a newspaper reporter went out to interview a person who had seen a UFO, intelligence agents had already been flown in, gotten the detailed story complete with sketches of the UFO, and sped back to their base to send the report to Project Sign. Many people had supposedly been "warned" not to talk too much. The Air Force was mighty interested in hallucinations. Thus 1947 ended with various-sized question marks in the mind of the public. If you followed flying saucers closely the question mark was big, if you just noted the UFO story titles in the papers it was smaller, but it was there and it was growing. Probably none of the people, military or civilian, who had made the public statements were at all qualified to do so but they had done it, their comments had been printed, and their comments had been read. Their comments formed the question mark. CHAPTER THREE The Classics 1948 was only one hour and twenty-five minutes old when a gentleman from Abilene, Texas, made the first UFO report of the year. What he saw, "a fan-shaped glow" in the sky, was insignificant as far as UFO reports go, but it ushered in a year that was to bring feverish activity to Project Sign. With the Soviets practically eliminated as a UFO source, the idea of interplanetary spaceships was becoming more popular. During 1948 the people in ATIC were openly discussing the possibility of interplanetary visitors without others tapping their heads and looking smug. During 1948 the novelty of UFO's had worn off for the press and every John and Jane Doe who saw one didn't make the front pages as in 1947. Editors were becoming hardened, only a few of the best reports got any space. Only "The Classics" rated headlines. "The Classics" were three historic reports that were the highlights of 1948. They are called "The Classics," a name given them by the Project Blue Book staff, because: (1) they are classic examples of how the true facts of a UFO report can be twisted and warped by some writers to prove their point, (2) they are the most highly publicized reports of this early era of the UFO's, and (3) they "proved" to ATIC's intelligence specialists that UFO's were real. The apparent lack of interest in UFO reports by the press was not a true indication of the situation. I later found out, from talking to writers, that all during 1948 the interest in UFO's was running high. The Air Force Press Desk in the Pentagon was continually being asked what progress was being made in the UFO investigation. The answer was, "Give us time. This job can't be done in a week." The press respected this and was giving them time. But every writer worth his salt has contacts, those "usually reliable sources" you read about, and these contacts were talking. All during 1948 contacts in the Pentagon were telling how UFO reports were rolling in at the rate of several per day and how ATIC UFO investigation teams were flying out of Dayton to investigate them. They were telling how another Air Force investigative organization had been called in to lighten ATIC's load and allow ATIC to concentrate on the analysis of the reports. The writers knew this was true because they had crossed paths with these men whom they had mistakenly identified as FBI agents. The FBI was never officially interested in UFO sightings. The writers' contacts in the airline industry told about the UFO talk from V.P.'s down to the ramp boys. Dozens of good, solid, reliable, experienced airline pilots were seeing UFO's. All of this led to one conclusion: whatever the Air Force had to say, when it was ready to talk, would be newsworthy. But the Air Force wasn't ready to talk. Project Sign personnel were just getting settled down to work after the New Year's holiday when the "ghost rockets" came back to the Scandinavian countries of Europe. Air attaches in Sweden, Denmark, and Norway fired wires to ATIC telling about the reports. Wires went back asking for more information. The "ghost rockets," so tagged by the newspapers, had first been seen in the summer of 1946, a year before the first UFO sighting in the U.S. There were many different descriptions for the reported objects. They were usually seen in the hours of darkness and almost always traveling at extremely high speeds. They were shaped like a ball or projectile, were a bright green, white, red, or yellow and sometimes made sounds. Like their American cousins, they were always so far away that no details could be seen. For no good reason, other than speculation and circulation, the newspapers had soon begun to refer authoritatively to these "ghost rockets" as guided missiles, and implied that they were from Russia. Peenemunde, the great German missile development center and birthplace of the V-l and V-2 guided missiles, came in for its share of suspicion since it was held by the Russians. By the end of the summer of 1946 the reports were widespread, coming from Denmark, Norway, Spain, Greece, French Morocco, Portugal, and Turkey. In 1947, after no definite conclusions as to identity of the "rockets" had been established, the reports died out. Now in early January 1948 they broke out again. But Project Sign personnel were too busy to worry about European UFO reports, they were busy at home. A National Guard pilot had just been killed chasing a UFO. On January 7 all of the late papers in the U.S. carried headlines similar to those in the Louisville _Courier_: "F-51 and Capt. Mantell Destroyed Chasing Flying Saucer." This was Volume I of "The Classics," the Mantell Incident. At one-fifteen on that afternoon the control tower operators at Godman AFB, outside Louisville, Kentucky, received a telephone call from the Kentucky State Highway Patrol. The patrol wanted to know if Godman Tower knew anything about any unusual aircraft in the vicinity. Several people from Maysville, Kentucky, a small town 80 miles east of Louisville, had reported seeing a strange aircraft. Godman knew that they had nothing in the vicinity so they called Flight Service at Wright-Patterson AFB. In a few minutes Flight Service called back. Their air Traffic control board showed no flights in the area. About twenty minutes later the state police called again. This time people from the towns of Owensboro and Irvington, Kentucky, west of Louisville, were reporting a strange craft. The report from these two towns was a little more complete. The townspeople had described the object to the state police as being "circular, about 250 to 300 feet in diameter," and moving westward at a "pretty good clip." Godman Tower checked Flight Service again. Nothing. All this time the tower operators had been looking for the reported object. They theorized that since the UFO had had to pass north of Godman to get from Maysville to Owensboro it might come back. At one forty-five they saw it, or something like it. Later, in his official report, the assistant tower operator said that he had seen the object for several minutes before he called his chiefs attention to it. He said that he had been reluctant to "make a flying saucer report." As soon as the two men in the tower had assured themselves that the UFO they saw was not an airplane or a weather balloon, they called Flight Operations. They wanted the operations officer to see the UFO. Before long word of the sighting had gotten around to key personnel on the base, and several officers, besides the base operations officer and the base intelligence officer, were in the tower. All of them looked at the UFO through the tower's 6 x 50 binoculars and decided they couldn't identify it. About this time Colonel Hix, the base commander, arrived. He looked and he was baffled. At two-thirty, they reported, they were discussing what should be done when four F-51's came into view, approaching the base from the south. The tower called the flight leader, Captain Mantell, and asked him to take a look at the object and try to identify it. One F-51 in the flight was running low on fuel, so he asked permission to go on to his base. Mantell took his two remaining wing men, made a turn, and started after the UFO. The people in Godman Tower were directing him as none of the pilots could see the object at this time. They gave Mantell an initial heading toward the south and the flight was last seen heading in the general direction of the UFO. By the time the F-51's had climbed to 10,000 feet, the two wing men later reported, Mantell had pulled out ahead of them and they could just barely see him. At two forty-five Mantell called the tower and said, "I see something above and ahead of me and I'm still climbing." All the people in the tower heard Mantell say this and they heard one of the wing men call back and ask, "What the hell are we looking for?" The tower immediately called Mantell and asked him for a description of what he saw. Odd as it may seem, no one can remember exactly what he answered. Saucer historians have credited him with saying, "I've sighted the thing. It looks metallic and it's tremendous in size. . . . Now it's starting to climb." Then in a few seconds he is supposed to have called and said, "It's above me and I'm gaining on it. I'm going to 20,000 feet." Everyone in the tower agreed on this one last bit of the transmission, "I'm going to 20,000 feet," but didn't agree on the first part, about the UFO's being metallic and tremendous. The two wing men were now at 15,000 feet and trying frantically to call Mantell. He had climbed far above them by this time and was out of sight. Since none of them had any oxygen they were worried about Mantell. Their calls were not answered. Mantell never talked to anyone again. The two wing men leveled off at 15,000 feet, made another fruitless effort to call Mantell, and started to come back down. As they passed Godman Tower on their way to their base, one of them said something to the effect that all he had seen was a reflection on his canopy. When they landed at their base, Standiford Field, just north of Godman, one pilot had his F-51 refueled and serviced with oxygen, and took off to search the area again. He didn't see anything. At three-fifty the tower lost sight of the UFO. A few minutes later they got word that Mantell had crashed and was dead. Several hours later, at 7:20P.M., airfield towers all over the Midwest sent in frantic reports of another UFO. In all about a dozen airfield towers reported the UFO as being low on the southwestern horizon and disappearing after about twenty minutes. The writers of saucer lore say this UFO was what Mantell was chasing when he died; the Air Force says _this_ UFO was Venus. The people on Project Sign worked fast on the Mantell Incident. Contemplating a flood of queries from the press as soon as they heard about the crash, they realized that they had to get a quick answer. Venus had been the target of a chase by an Air Force F-51 several weeks before and there were similarities between this sighting and the Mantell Incident. So almost before the rescue crews had reached the crash, the word "Venus" went out. This satisfied the editors, and so it stood for about a year; Mantell had unfortunately been killed trying to reach the planet Venus. To the press, the nonchalant, offhand manner with which the sighting was written off by the Air Force public relations officer showed great confidence in the conclusion, Venus, but behind the barbed-wire fence that encircled ATIC the nonchalant attitude didn't exist among the intelligence analysts. One man had already left for Louisville and the rest were doing some tall speculating. The story about the tower-to-air talk. "It looks metallic and it's tremendous in size," spread fast. Rumor had it that the tower had carried on a running conversation with the pilots and that there was more information than was so far known. Rumor also had it that this conversation had been recorded. Unfortunately neither of these rumors was true. Over a period of several weeks the file on the Mantell Incident grew in size until it was the most thoroughly investigated sighting of that time, at least the file was the thickest. About a year later the Air Force released its official report on the incident. To use a trite term, it was a masterpiece in the art of "weasel wording." It said that the UFO might have been Venus or it could have been a balloon. Maybe two balloons. It probably was Venus except that this is doubtful because Venus was too dim to be seen in the afternoon. This jolted writers who had been following the UFO story. Only a few weeks before, _The_ _Saturday_ _Evening_ _Post_ had published a two-part story entitled "What You Can Believe about Flying Saucers." The story had official sanction and had quoted the Venus theory as a positive solution. To clear up the situation, several writers were allowed to interview a major in the Pentagon, who was the Air Force's Pentagon "expert" on UFO's. The major was asked directly about the conclusion of the Mantell Incident, and he flatly stated that it was Venus. The writers pointed out the official Air Force analysis. The major's answer was, "They checked again and it was Venus." He didn't know who "they" were, where they had checked, or what they had checked, but it was Venus. The writers then asked, "If there was a later report they had made why wasn't it used as a conclusion?" "Was it available?" The answer to the last question was "No," and the lid snapped back down. This interview gave the definite impression that the Air Force was unsuccessfully trying to cover up some very important information, using Venus as a front. Nothing excites a newspaper or magazine writer more than to think he has stumbled onto a big story and that someone is trying to cover it up. Many writers thought this after the interview with the major, and many still think it. You can't really blame them, either. In early 1952 I got a telephone call on ATIC's direct line to the Pentagon. It was a colonel in the Director of Intelligence's office. The Office of Public Information had been getting a number of queries about all of the confusion over the Mantell Incident. What was the answer? I dug out the file. In 1949 all of the original material on the incident had been microfilmed, but something had been spilled on the film. Many sections were so badly faded they were illegible. As I had to do with many of the older sightings that were now history, I collected what I could from the file, filling in the blanks by talking to people who had been at ATIC during the early UFO era. Many of these people were still around, "Red" Honnacker, George Towles, Al Deyarmond, Nick Post, and many others. Most of them were civilians, the military had been transferred out by this time. Some of the press clippings in the file mentioned the Pentagon major and his concrete proof of Venus. I couldn't find this concrete proof in the file so I asked around about the major. The major, I found, was an officer in the Pentagon who had at one time written a short intelligence summary about UFO's. He had never been stationed at ATIC, nor was he especially well versed on the UFO problem. When the word of the press conference regarding the Mantell Incident came down, a UFO expert was needed. The major, because of his short intelligence summary on UFO's, became the "expert." He had evidently conjured up "they" and "their later report" to support his Venus answer because the writers at the press conference had him in a corner. I looked farther. Fortunately the man who had done the most extensive work on the incident, Dr. J. Allen Hynek, head of the Ohio State University Astronomy Department, could be contacted. I called Dr. Hynek and arranged to meet him the next day. Dr. Hynek was one of the most impressive scientists I met while working on the UFO project, and I met a good many. He didn't do two things that some of them did: give you the answer before he knew the question; or immediately begin to expound on his accomplishments in the field of science. I arrived at Ohio State just before lunch, and Dr. Hynek invited me to eat with him at the faculty club. He wanted to refer to some notes he had on the Mantell Incident and they were in his office, so we discussed UFO's in general during lunch. Back in his office he started to review the Mantell Incident. He had been responsible for the weasel-worded report that the Air Force released in late 1949, and he apologized for it. Had he known that it was going to cause so much confusion, he said, he would have been more specific. He thought the incident was a dead issue. The reason that Venus had been such a strong suspect was that it was in almost the same spot in the sky as the UFO. Dr. Hynek referred to his notes and told me that at 3:00P.M., Venus had been south southwest of Godman and 33 degrees above the southern horizon. At 3:00P.M. the people in the tower estimated the UFO to be southwest of Godman and at an elevation of about 45 degrees. Allowing for human error in estimating directions and angles, this was close. I agreed. There was one big flaw in the theory, however. Venus wasn't bright enough to be seen. He had computed the brilliance of the planet, and on the day in question it was only six times as bright as the surrounding sky. Then he explained what this meant. Six times may sound like a lot, but it isn't. When you start looking for a pinpoint of light only six times as bright as the surrounding sky, it's almost impossible to find it, even on a clear day. Dr. Hynek said that he didn't think that the UFO was Venus. I later found out that although it was a relatively clear day there was considerable haze. I asked him about some of the other possibilities. He repeated the balloon, canopy-reflection, and sundog theories but he refused to comment on them since, as he said, he was an astrophysicist and would care to comment only on the astrophysical aspects of the sightings. I drove back to Dayton convinced that the UFO wasn't Venus. Dr. Hynek had said Venus would have been a pinpoint of light. The people in the tower had been positive of their descriptions, their statements brought that out. They couldn't agree on a description, they called the UFO "a parachute," "an ice cream cone tipped with red," "round and white," "huge and silver or metallic," "a small white object," "one fourth the size of the full moon," but all the descriptions plainly indicated a large object. None of the descriptions could even vaguely be called a pinpoint of light. This aspect of a definite shape seemed to eliminate the sundog theory too. Sundogs, or parhelia, as they are technically known, are caused by ice particles reflecting a diffused light. This would not give a sharp outline. I also recalled two instances where Air Force pilots had chased sundogs. In both instances when the aircraft began to climb, the sundog disappeared. This was because the angle of reflection changed as the airplane climbed several thousand feet. These sundog-caused UFO's also had fuzzy edges. I had always heard a lot of wild speculation about the condition of Mantell's crashed F-51, so I wired for a copy of the accident report. It arrived several days after my visit with Dr. Hynek. The report said that the F-51 had lost a wing due to excessive speed in a dive after Mantell had "blacked out" due to the lack of oxygen. Mantell's body had not burned, not disintegrated, and was not full of holes; the wreck was not radioactive, nor was it magnetized. One very important and pertinent question remained. Why did Mantell, an experienced pilot, try to go to 20,000 feet when he didn't even have an oxygen mask? If he had run out of oxygen, it would have been different Every pilot and crewman has it pounded into him, "Do not, under any circumstances, go above 15,000 feet without oxygen." In high-altitude indoctrination during World War II, I made several trips up to 30,000 feet in a pressure chamber. To demonstrate anoxia we would leave our oxygen masks off until we became dizzy. A few of the more hardy souls could get to 15,000 feet, but nobody ever got over 17,000. Possibly Mantell thought he could climb up to 20,000 in a hurry and get back down before he got anoxia and blacked out, but this would be a foolish chance. This point was covered in the sighting report. A long-time friend of Mantell's went on record as saying that he'd flown with him several years and knew him personally. He couldn't conceive of Mantell's even thinking about disregarding his lack of oxygen. Mantell was one of the most cautious pilots he knew. "The only thing I can think," he commented, "was that he was after something that he believed to be more important than his life or his family." My next step was to try to find out what Mantell's wing men had seen or thought but this was a blind alley. All of this evidence was in the ruined portion of the microfilm, even their names were missing. The only reference I could find to them was a vague passage indicating they hadn't seen anything. I concentrated on the canopy-reflection theory. It is widely believed that many flying saucers appear to pilots who are actually chasing a reflection on their canopy. I checked over all the reports we had on file. I couldn't find one that had been written off for this reason. I dug back into my own flying experience and talked to a dozen pilots. All of us had momentarily been startled by a reflection on the aircraft's canopy or wing, but in a second or two it had been obvious that it was a reflection. Mantell chased the object for at least fifteen to twenty minutes, and it is inconceivable that he wouldn't realize in that length of time that he was chasing a reflection. About the only theory left to check was that the object might have been one of the big, 100-foot-diameter, "skyhook" balloons. I rechecked the descriptions of the UFO made by the people in the tower. The first man to sight the object called it a parachute; others said ice cream cone, round, etc. All of these descriptions fit a balloon. Buried deep in the file were two more references to balloons that I had previously missed. Not long after the object had disappeared from view at Godman AFB, a man from Madisonville, Kentucky, called Flight Service in Dayton. He had seen an object traveling southeast. He had looked at it through a telescope and it was a balloon. At four forty-five an astronomer living north of Nashville, Tennessee, called in. He had also seen a UFO, looked at it through a telescope, and it was a balloon. In the thousands of words of testimony and evidence taken on the Mantell Incident this was the only reference to balloons. I had purposely not paid too much attention to this possibility because I was sure that it had been thoroughly checked back in 1948. Now I wasn't sure. I talked with one of the people who had been in on the Mantell investigation. The possibility of a balloon's causing the sighting had been mentioned but hadn't been followed up for two reasons. Number one was that everybody at ATIC was convinced that the object Mantell was after was a spaceship and that this was the only course they had pursued. When the sighting grew older and no spaceship proof could be found, everybody jumped on the Venus band wagon, as this theory had "already been established." It was an easy way out. The second reason was that a quick check had been made on weather balloons and none were in the area. The big skyhook balloon project was highly classified at that time, and since they were all convinced that the object was of interplanetary origin (a minority wanted to give the Russians credit), they didn't want to bother to buck the red tape of security to get data on skyhook flights. The group who supervise the contracts for all the skyhook research flights for the Air Force are located at Wright Field, so I called them. They had no records on flights in 1948 but they did think that the big balloons were being launched from Clinton County AFB in southern Ohio at that time. They offered to get the records of the winds on January 7 and see what flight path a balloon launched in southwestern Ohio would have taken. In a few days they had the data for me. Unfortunately the times of the first sightings, from the towns outside Louisville, were not exact but it was possible to partially reconstruct the sequence of events. The winds were such that a skyhook balloon launched from Clinton County AFB could be seen from the town east of Godman AFB, the town from which the first UFO was reported to the Kentucky State Police. It is not unusual to be able to see a large balloon for 50 to 60 miles. The balloon could have traveled west for a while, climbing as it moved with the strong east winds that were blowing that day and picking up speed as the winds got stronger at altitude. In twenty minutes it could have been in a position where it could be seen from Owensboro and Irvington, Kentucky, the two towns west of Godman. The second reports to the state police had come from these two towns. Still climbing, the balloon would have reached a level where a strong wind was blowing in a southerly direction. The jet-stream winds were not being plotted in 1948 but the weather chart shows strong indications of a southerly bend in the jet stream for this day. Jet stream or not, the balloon would have moved rapidly south, still climbing. At a point somewhere south or southwest of Godman it would have climbed through the southerly-moving winds to a calm belt at about 60,000 feet. At this level it would slowly drift south or southeast. A skyhook balloon can be seen at 60,000. When first seen by the people in Godman Tower, the UFO was south of the air base. It was relatively close and looked "like a parachute," which a balloon does. During the two hours that it was in sight, the observers reported that it seemed to hover, yet each observer estimated the time he looked at the object through the binoculars and timewise the descriptions ran "huge," "small," "one fourth the size of a full moon," "one tenth the size of a full moon." Whatever the UFO was, it was slowly moving away. As the balloon continued to drift in a southerly direction it would have picked up stronger winds, and could have easily been seen by the astronomers in Madisonville, Kentucky, and north of Nashville an hour after it disappeared from view at Godman. Somewhere in the archives of the Air Force or the Navy there are records that will show whether or not a balloon was launched from Clinton County AFB, Ohio, on January 7, 1948. I never could find these records. People who were working with the early skyhook projects "remember" operating out of Clinton County AFB in 1947 but refuse to be pinned down to a January 7 flight. Maybe, they said. The Mantell Incident is the same old UFO jigsaw puzzle. By assuming the shape of one piece, a balloon launched from southwestern Ohio, the whole picture neatly falls together. It shows a huge balloon that Captain Thomas Mantell died trying to reach. He didn't know that he was chasing a balloon because he had never heard of a huge, 100-foot- diameter skyhook balloon, let alone seen one. Leave out the one piece of the jigsaw puzzle and the picture is a UFO, "metallic and tremendous in size." It _could_ have been a balloon. This is the answer I phoned back to the Pentagon. During January and February of 1948 the reports of "ghost rockets" continued to come from air attaches in foreign countries near the Baltic Sea. People in North Jutland, Norway, Denmark, Sweden, and Germany reported "balls of fire traveling slowly across the sky." The reports were very sketchy and incomplete, most of them accounts from newspapers. In a few days the UFO's were being seen all over Europe and South America. Foreign reports hit a peak in the latter part of February and U.S. newspapers began to pick up the stories. The Swedish Defense Staff supposedly conducted a comprehensive study of the incidents and concluded that they were all explainable in terms of astronomical phenomena. Since this was UFO history, I made several attempts to get some detailed and official information on this report and the sightings, but I was never successful. The ghost rockets left in March, as mysteriously as they had arrived. All during the spring of 1948 good reports continued to come in. Some were just run-of-the-mill but a large percentage of them were good, coming from people whose reliability couldn't be questioned. For example, three scientists reported that for thirty seconds they had watched a round object streak across the sky in a highly erratic flight path near the Army's secret White Sands Proving Ground. And on May 28 the crew of an Air Force C-47 had three UFO's barrel in from "twelve o'clock high" to buzz their transport. On July 21 a curious report was received from the Netherlands. The day before several persons reported seeing a UFO through high broken clouds over The Hague. The object was rocket-shaped, with two rows of windows along the side. It was a poor report, very sketchy and incomplete, and it probably would have been forgotten except that four nights later a similar UFO almost collided with an Eastern Airlines DC-3. This near collision is Volume II of "The Classics." On the evening of July 24, 1948, an Eastern Airlines DC-3 took off from Houston, Texas. It was on a scheduled trip to Atlanta, with intermediate stops in between. The pilots were Clarence S. Chiles and John B. Whitted. At about 2:45 A.M., when the flight was 20 miles southwest of Montgomery, the captain, Chiles, saw a light dead ahead and closing fast. His first reaction, he later reported to an ATIC investigation team, was that it was a jet, but in an instant he realized that even a jet couldn't close as fast as this light was closing. Chiles said he reached over, gave Whitted, the other pilot, a quick tap on the arm, and pointed. The UFO was now almost on top of them. Chiles racked the DC-3 into a tight left turn. Just as the UFO flashed by about 700 feet to the right, the DC-3 hit turbulent air. Whitted looked back just as the UFO pulled up in a steep climb. Both the pilots had gotten a good look at the UFO and were able to give a good description to the Air Force intelligence people. It was a B-29 fuselage. The underside had a "deep blue glow." There were "two rows of windows from which bright lights glowed," and a "50-foot trail of orange-red flame" shot out the back. Only one passenger was looking out of the window at the time. The ATIC investigators talked to him. He said he saw a "strange, eerie streak of light, very intense," but that was all, no details. He said that it all happened before he could adjust his eyes to the darkness. Minutes later a crew chief at Robins Air Force Base in Macon, Georgia, reported seeing an extremely bright light pass overhead, traveling at a high speed. A few days later another report from the night of July 24 came in. A pilot, flying near the Virginia-North Carolina state line, reported that he had seen a "bright shooting star" in the direction of Montgomery, Alabama, at about the exact time the Eastern Airlines DC-3 was "buzzed." According to the old timers at ATIC, this report shook them worse than the Mantell Incident. This was the first time two reliable sources had been really close enough to anything resembling a UFO to get a good look and live to tell about it. A quick check on a map showed that the UFO that nearly collided with the airliner would have passed almost over Macon, Georgia, after passing the DC-3. It had been turning toward Macon when last seen. The story of the crew chief at Robins AFB, 200 miles away, seemed to confirm the sighting, not to mention the report from near the Virginia-North Carolina state line. In intelligence, if you have something to say about some vital problem you write a report that is known as an "Estimate of the Situation." A few days after the DC-3 was buzzed, the people at ATIC decided that the time had arrived to make an Estimate of the Situation. The situation was the UFO's; the estimate was that they were interplanetary! It was a rather thick document with a black cover and it was printed on legal-sized paper. Stamped across the front were the words TOP SECRET. It contained the Air Force's analysis of many of the incidents I have told you about plus many similar ones. All of them had come from scientists, pilots, and other equally credible observers, and each one was an unknown. The document pointed out that the reports hadn't actually started with the Arnold Incident. Belated reports from a weather observer in Richmond, Virginia, who observed a "silver disk" through his theodolite telescope; an F-47 pilot and three pilots in his formation who saw a "silver flying wing," and the English "ghost airplanes" that had been picked up on radar early in 1947 proved this point. Although reports on them were not received until after the Arnold sighting, these incidents all had taken place earlier. When the estimate was completed, typed, and approved, it started up through channels to higher-command echelons. It drew considerable comment but no one stopped it on its way up. A matter of days after the Estimate of the Situation was signed, sealed, and sent on its way, the third big sighting of 1948, Volume III of "The Classics," took place. The date was October 1, and the place was Fargo, North Dakota; it was the famous Gorman Incident, in which a pilot fought a "duel of death" with a UFO. The pilot was George F. Gorman, a twenty-five-year-old second lieutenant in the North Dakota Air National Guard. It was eight-thirty in the evening and Gorman was coming into Fargo from a cross-country flight. He flew around Fargo for a while and about nine o'clock decided to land. He called the control tower for landing instructions and was told that a Piper Cub was in the area. He saw the Cub below him. All of a sudden what appeared to be the taillight of another airplane passed him on his right. He called the tower and complained but they assured him that no other aircraft except the Cub were in the area. Gorman could still see the light so he decided to find out what it was. He pushed the F-51 over into a turn and cut in toward the light. He could plainly see the Cub outlined against the city lights below, but he could see no outline of a body near the mysterious light. He gave the '51 more power and closed to within a 1,000 yards, close enough to estimate that the light was 6 to 8 inches in diameter, was sharply outlined, and was blinking on and off. Suddenly the light became steady as it apparently put on power; it pulled into a sharp left bank and made a pass at the tower. The light zoomed up with the F-51 in hot pursuit. At 7,000 feet it made a turn. Gorman followed and tried to cut inside the light's turn to get closer to it but he couldn't do it. The light made another turn, and this time the '51 closed on a collision course. The UFO appeared to try to ram the '51, and Gorman had to dive to get out of the way. The UFO passed over the '51's canopy with only a few feet to spare. Again both the F-51 and the object turned and closed on each other head on, and again the pilot had to dive out to prevent a collision. All of a sudden the light began to climb and disappeared. "I had the distinct impression that its maneuvers were controlled by thought or reason," Gorman later told ATIC investigators. Four other observers at Fargo partially corroborated his story, an oculist, Dr. A. D. Cannon, the Cub's pilot, and his passenger, Einar Neilson. They saw a light "moving fast," but did not witness all the maneuvers that Gorman reported. Two CAA employees on the ground saw a light move over the field once. Project Sign investigators rushed to Fargo. They had wired ahead to ground the plane. They wanted to check it over before it flew again. When they arrived, only a matter of hours after the incident, they went over the airplane, from the prop spinner to the rudder trim tab, with a Geiger counter. A chart in the official report shows where every Geiger counter reading was taken. For comparison they took readings on a similar airplane that hadn't been flown for several days. Gorman's airplane was more radioactive. They rushed around, got sworn statements from the tower operators and oculist, and flew back to Dayton. In the file on the Gorman Incident I found an old memo reporting the meeting that was held upon the ATIC team's return from Fargo. The memo concluded that some weird things were taking place. The historians of the UFO agree. Donald Keyhoe, a retired Marine Corps major and a professional writer, author of _The_ _Flying_ _Saucers_ _Are_ _Real_ and _Flying_ _Saucers_ _from_ _Outer_ _Space_, needles the Air Force about the Gorman Incident, pointing out how, after feebly hinting that the light could have been a lighted weather balloon, they dropped it like a hot UFO. Some person by the name of Wilkins, in an equally authoritative book, says that the Gorman Incident "stumped" the Air Force. Other assorted historians point out that normally the UFO's are peaceful, Gorman and Mantell just got too inquisitive, "they" just weren't ready to be observed closely. If the Air Force hadn't slapped down the security lid, these writers might not have reached this conclusion. There have been other and more lurid "duels of death." On June 21, 1952, at 10:58P.M., a Ground Observer Corps spotter reported that a slow-moving craft was nearing the AEC's Oak Ridge Laboratory, an area so secret that it is prohibited to aircraft. The spotter called the light into his filter center and the filter center relayed the message to the ground control intercept radar. They had a target. But before they could do more than confirm the GOC spotter's report, the target faded from the radarscope. An F-47 aircraft on combat air patrol in the area was vectored in visually, spotted a light, and closed on it. They "fought" from 10,000 to 27,000 feet, and several times the object made what seemed to be ramming attacks. The light was described as white, 6 to 8 inches in diameter, and blinking until it put on power. The pilot could see no silhouette around the light. The similarity to the Fargo case was striking. On the night of December 10, 1952, near another atomic installation, the Hanford plant in Washington, the pilot and radar observer of a patrolling F-94 spotted a light while flying at 26,000 feet. The crew called their ground control station and were told that no planes were known to be in the area. They closed on the object and saw a large, round, white "thing" with a dim reddish light coming from two "windows." They lost visual contact, but got a radar lock-on. They reported that when they attempted to close on it again it would reverse direction and dive away. Several times the plane altered course itself because collision seemed imminent. In each of these instances, as well as in the case narrated next, the sources of the stories were trained airmen with excellent reputations. They were sincerely baffled by what they had seen. They had no conceivable motive for falsifying or "dressing up" their reports. The other dogfight occurred September 24, 1952, between a Navy pilot of a TBM and a light over Cuba. The pilot had just finished making some practice passes for night fighters when he spotted an orange light to the east of his plane. He checked on aircraft in the area, learned that the object was unidentified, and started after it. Here is his report, written immediately after he landed: As it [the light] approached the city from the east it started a left turn. I started to intercept. During the first part of the chase the closest I got to the light was 8 to 10 miles. At this time it appeared to be as large as an SNJ and had a greenish tail that looked to be five to six times as long as the light's diameter. This tail was seen several times in the next 10 minutes in periods of from 5 to 30 seconds each. As I reached 10,000 feet it appeared to be at 15,000 feet and in a left turn. It took 40 degrees of bank to keep the nose of my plane on the light. At this time I estimated the light to be in a 10-to-15-mile orbit. At 12,000 feet I stopped climbing, but the light was still climbing faster than I was. I then reversed my turn from left to right and the light also reversed. As I was not gaining distance, I held a steady course south trying to estimate a perpendicular between the light and myself. The light was moving north, so I turned north. As I turned, the light appeared to move west, then south over the base. I again tried to intercept but the light appeared to climb rapidly at a 60- degree angle. It climbed to 35,000 feet, then started a rapid descent. Prior to this, while the light was still at approximately 15,000 feet, I deliberately placed it between the moon and myself three times to try to identify a solid body. I and my two crewmen all had a good view of the light as it passed the moon. We could see no solid body. We considered the fact that it might be an aerologist's balloon, but we did not see a silhouette. Also, we would have rapidly caught up with and passed a balloon. During its descent, the light appeared to slow down at about 10,000 feet, at which time I made three runs on it. Two were on a 90-degree collision course, and the light traveled at tremendous speed across my bow. On the third run I was so close that the light blanked out the airfield below me. Suddenly it started a dive and I followed, losing it at 1,500 feet. In _this_ incident the UFO _was_ a balloon. The following night a lighted balloon was sent up and the pilot was ordered up to compare his experiences. He duplicated his dogfight-- illusions and all. The Navy furnished us with a long analysis of the affair, explaining how the pilot had been fooled. In the case involving the ground observer and the F-47 near the atomic installation, we plotted the winds and calculated that a lighted balloon was right at the spot where the pilot encountered the light. In the other instance, the "white object with two windows," we found that a skyhook balloon had been plotted at the exact site of the "battle." Gorman fought a lighted balloon too. An analysis of the sighting by the Air Weather Service sent to ATIC in a letter dated January 24, 1949, proved it. The radioactive F-51 was decontaminated by a memo from a Wright Field laboratory explaining that a recently flown airplane will be more radioactive than one that has been on the ground for several days. An airplane at 20,000 to 30,000 feet picks up more cosmic rays than one shielded by the earth's ever present haze. Why can't experienced pilots recognize a balloon when they see one? If they are flying at night, odd things can happen to their vision. There is the problem of vertigo as well as disorientation brought on by flying without points of reference. Night fighters have told dozens of stories of being fooled by lights. One night during World War II we had just dumped a load of bombs on a target when a "night fighter" started to make a pass at us. Everyone in the cockpit saw the fighter's red-hot exhaust stack as he bore down on us. I cut loose with six caliber-.50 machine guns. Fortunately I missed the "night fighter"--if I'd have shot it I'd have fouled up the astronomers but good because the "night fighter" was Venus. While the people on Project Sign were pondering over Lieutenant Gorman's dogfight with the UFO--at the time they weren't even considering the balloon angle--the Top Secret Estimate of the Situation was working its way up into the higher echelons of the Air Force. It got to the late General Hoyt S. Vandenberg, then Chief of Staff, before it was batted back down. The general wouldn't buy interplanetary vehicles. The report lacked proof. A group from ATIC went to the Pentagon to bolster their position but had no luck, the Chief of Staff just couldn't be convinced. The estimate died a quick death. Some months later it was completely declassified and relegated to the incinerator. A few copies, one of which I saw, were kept as mementos of the golden days of the UFO's. The top Air Force command's refusal to buy the interplanetary theory didn't have any immediate effect upon the morale of Project Sign because the reports were getting better. A belated report that is more of a collectors' item than a good UFO sighting came into ATIC in the fall of 1948. It was from Moscow. Someone, I could never find out exactly who, reported a huge "smudge- like" object in the sky. Then radar came into the picture. For months the anti-saucer factions had been pointing their fingers at the lack of radar reports, saying, "If they exist, why don't they show up on radarscopes?" When they showed up on radarscopes, the UFO won some converts. On October 15 an F-61, a World War II "Black Widow" night fighter, was on patrol over Japan when it picked up an unidentified target on its radar. The target was flying between 5,000 and 6,000 feet and traveling about 200 miles per hour. When the F-61 tried to intercept it would get to within 12,000 feet of the UFO only to have it accelerate to an estimated 1,200 miles per hour, leaving the F-61 far behind before slowing down again. The F-61 crew made six attempts to close on the UFO. On one pass, the crew said, they did get close enough to see its silhouette. It was 20 to 30 feet long and looked "like a rifle bullet." Toward the end of November a wire came into Project Sign from Germany. It was the first report where a UFO was seen and simultaneously picked up on radar. This type of report, the first of many to come, is one of the better types of UFO reports. The wire said: At 2200 hours, local time, 23 November 1948, Capt. ------ saw an object in the air directly east of this base. It was at an unknown altitude. It looked like a reddish star and was moving in a southerly direction across Munich, turning slightly to the southwest then the southeast. The speed could have been between 200 to 600 mph, the actual speed could not be estimated, not knowing the height. Capt. --- --- called base operations and they called the radar station. Radar reported that they had seen nothing on their scope but would check again. Radar then called operations to report that they did have a target at 27,000 feet, some 30 miles south of Munich, traveling at 900 mph. Capt. ------ reported that the object that he saw was now in that area. A few minutes later radar called again to say that the target had climbed to 50,000 feet, and was circling 40 miles south of Munich. Capt. ------ is an experienced pilot now flying F-80's and is considered to be completely reliable. The sighting was verified by Capt. ------ , also an F-80 pilot. The possibility that this was a balloon was checked but the answer from Air Weather Service was "not a balloon." No aircraft were in the area. Nothing we know of, except possibly experimental aircraft, which are not in Germany, can climb 23,000 feet in a matter of minutes and travel 900 miles per hour. By the end of 1948, Project Sign had received several hundred UFO reports. Of these, 167 had been saved as good reports. About three dozen were "Unknown." Even though the UFO reports were getting better and more numerous, the enthusiasm over the interplanetary idea was cooling off. The same people who had fought to go to Godman AFB to talk to Colonel Hix and his UFO observers in January now had to be prodded when a sighting needed investigating. More and more work was being pushed off onto the other investigative organization that was helping ATIC. The kickback on the Top Secret Estimate of the Situation was beginning to dampen a lot of enthusiasms. It was definitely a bear market for UFO's. A bull market was on the way, however. Early 1949 was to bring "little lights" and green fireballs. The "little lights" were UFO's, but the green fireballs were real. CHAPTER FOUR Green Fireballs, Project Twinkle, Little Lights, and Grudge At exactly midnight on September 18, 1954, my telephone rang. It was Jim Phalen, a friend of mine from the Long Beach _Press-Telegram_, and he had a "good flying saucer report," hot off the wires. He read it to me. The lead line was: "Thousands of people saw a huge fireball light up dark New Mexico skies tonight." The story went on to tell about how a "blinding green" fireball the size of a full moon had silently streaked southeast across Colorado and northern New Mexico at eight-forty that night. Thousands of people had seen the fireball. It had passed right over a crowded football stadium at Santa Fe, New Mexico, and people in Denver said it "turned night into day." The crew of a TWA airliner flying into Albuquerque from Amarillo, Texas, saw it. Every police and newspaper switchboard in the two-state area was jammed with calls. One of the calls was from a man inquiring if anything unusual had happened recently. When he was informed about the mysterious fireball he heaved an audible sigh of relief, "Thanks," he said, "I was afraid I'd gotten some bad bourbon." And he hung up. Dr. Lincoln La Paz, world-famous authority on meteorites and head of the University of New Mexico's Institute of Meteoritics, apparently took the occurrence calmly. The wire story said he had told a reporter that he would plot its course, try to determine where it landed, and go out and try to find it. "But," he said, "I don't expect to find anything." When Jim Phalen had read the rest of the report he asked, "What was it?" "It sounds to me like the green fireballs are back," I answered. "What the devil are green fireballs?" What the devil _are_ green fireballs? I'd like to know. So would a lot of other people. The green fireballs streaked into UFO history late in November 1948, when people around Albuquerque, New Mexico, began to report seeing mysterious "green flares" at night. The first reports mentioned only a "green streak in the sky," low on the horizon. From the description the Air Force Intelligence people at Kirtland AFB in Albuquerque and the Project Sign people at ATIC wrote the objects off as flares. After all, thousands of GI's had probably been discharged with a duffel bag full of "liberated" Very pistols and flares. But as days passed the reports got better. They seemed to indicate that the "flares" were getting larger and more people were reporting seeing them. It was doubtful if this "growth" was psychological because there had been no publicity--so the Air Force decided to reconsider the "flare" answer. They were in the process of doing this on the night of December 5, 1948, a memorable night in the green fireball chapter of UFO history. At 9:27P.M. on December 5, an Air Force C-47 transport was flying at 18,000 feet 10 miles east of Albuquerque. The pilot was a Captain Goede. Suddenly the crew, Captain Goede, his co-pilot, and his engineer were startled by a green ball of fire flashing across the sky ahead of them. It looked something like a huge meteor except that it was a bright green color and it didn't arch downward, as meteors usually do. The green-colored ball of fire had started low, from near the eastern slopes of the Sandia Mountains, arched upward a little, then seemed to level out. And it was too big for a meteor, at least it was larger than any meteor that anyone in the C-47 had ever seen before. After a hasty discussion the crew decided that they'd better tell somebody about it, especially since they had seen an identical object twenty-two minutes before near Las Vegas, New Mexico. Captain Goede picked up his microphone and called the control tower at Kirtland AFB and reported what he and his crew had seen. The tower relayed the message to the local intelligence people. A few minutes later the captain of Pioneer Airlines Flight 63 called Kirtland Tower. At 9:35P.M. he had also seen a green ball of fire just east of Las Vegas, New Mexico. He was on his way to Albuquerque and would make a full report when he landed. When he taxied his DC-3 up to the passenger ramp at Kirtland a few minutes later, several intelligence officers were waiting for him. He reported that at 9:35P.M. he was on a westerly heading, approaching Las Vegas from the east, when he and his co-pilot saw what they first thought was a "shooting star." It was ahead and a little above them. But, the captain said, it took them only a split second to realize that whatever they saw was too low and had too flat a trajectory to be a meteor. As they watched, the object seemed to approach their airplane head on, changing color from orange red to green. As it became bigger and bigger, the captain said, he thought sure it was going to collide with them so he racked the DC-3 up in a tight turn. As the green ball of fire got abreast of them it began to fall toward the ground, getting dimmer and dimmer until it disappeared. Just before he swerved the DC-3, the fireball was as big, or bigger, than a full moon. The intelligence officers asked a few more questions and went back to their office. More reports, which had been phoned in from all over northern New Mexico, were waiting for them. By morning a full-fledged investigation was under way. No matter what these green fireballs were, the military was getting a little edgy. They might be common meteorites, psychologically enlarged flares, or true UFO's, but whatever they were they were playing around in one of the most sensitive security areas in the United States. Within 100 miles of Albuquerque were two installations that were the backbone of the atomic bomb program, Los Alamos and Sandia Base. Scattered throughout the countryside were other installations vital to the defense of the U.S.: radar stations, fighter-interceptor bases, and the other mysterious areas that had been blocked off by high chain-link fences. Since the green fireballs bore some resemblance to meteors or meteorites, the Kirtland intelligence officers called in Dr. Lincoln La Paz. Dr. La Paz said that he would be glad to help, so the officers explained the strange series of events to him. True, he said, the description of the fireballs did sound as if they might be meteorites --except for a few points. One way to be sure was to try to plot the flight path of the green fireballs the same way he had so successfully plotted the flight path of meteorites in the past. From this flight path he could determine where they would have hit the earth--if they were meteorites. They would search this area, and if they found parts of a meteorite they would have the answer to the green fireball riddle. The fireball activity on the night of December 5 was made to order for plotting flight paths. The good reports of that night included carefully noted locations, the directions in which the green objects were seen, their heights above the horizon, and the times when they were observed. So early the next morning Dr. La Paz and a crew of intelligence officers were scouring northern New Mexico. They started out by talking to the people who had made reports but soon found out that dozens of other people had also seen the fireballs. By closely checking the time of the observations, they determined that eight separate fireballs had been seen. One was evidently more spectacular and was seen by the most people. Everyone in northern New Mexico had seen it going from west to east, so Dr. La Paz and his crew worked eastward across New Mexico to the west border of Texas, talking to dozens of people. After many sleepless hours they finally plotted where it should have struck the earth. They searched the area but found nothing. They went back over the area time and time again-- nothing. As Dr. La Paz later told me, this was the first time that he seriously doubted the green fireballs were meteorites. Within a few more days the fireballs were appearing almost nightly. The intelligence officers from Kirtland decided that maybe they could get a good look at one of them, so on the night of December 8 two officers took off in an airplane just before dark and began to cruise around north of Albuquerque. They had a carefully worked out plan where each man would observe certain details if they saw one of the green fireballs. At 6:33P.M. they saw one. This is their report: At 6:33P.M. while flying at an indicated altitude of 11,500 feet, a strange phenomenon was observed. Exact position of the aircraft at time of the observation was 20 miles east of the Las Vegas, N.M., radio range station. The aircraft was on a compass course of 90 degrees. Capt. ------ was pilot and I was acting as copilot. I first observed the object and a split second later the pilot saw it. It was 2,000 feet higher than the plane, and was approaching the plane at a rapid rate of speed from 30 degrees to the left of our course. The object was similar in appearance to a burning green flare, the kind that is commonly used in the Air Force. However, the light was much more intense and the object appeared considerably larger than a normal flare. The trajectory of the object, when first sighted, was almost flat and parallel to the earth. The phenomenon lasted about 2 seconds. At the end of this time the object seemed to begin to burn out and the trajectory then dropped off rapidly. The phenomenon was of such intensity as to be visible from the very moment it ignited. Back at Wright-Patterson AFB, ATIC was getting a blow-by-blow account of the fireball activity but they were taking no direct part in the investigation. Their main interest was to review all incoming UFO reports and see if the green fireball reports were actually unique to the Albuquerque area. They were. Although a good many UFO reports were coming in from other parts of the U.S., none fit the description of the green fireballs. All during December 1948 and January 1949 the green fireballs continued to invade the New Mexico skies. Everyone, including the intelligence officers at Kirtland AFB, Air Defense Command people, Dr. La Paz, and some of the most distinguished scientists at Los Alamos had seen at least one. In mid-February 1949 a conference was called at Los Alamos to determine what should be done to further pursue the investigation. The Air Force, Project Sign, the intelligence people at Kirtland, and other interested parties had done everything they could think of and still no answer. Such notable scientists as Dr. Joseph Kaplan, a world-renowned authority on the physics of the upper atmosphere, Dr. Edward Teller, of H-bomb fame, and of course Dr. La Paz, attended, along with a lot of military brass and scientists from Los Alamos. This was one conference where there was no need to discuss whether or not this special type of UFO, the green fireball, existed. Almost everyone at the meeting had seen one. The purpose of the conference was to decide whether the fireballs were natural or man-made and how to find out more about them. As happens in any conference, opinions were divided. Some people thought the green fireballs were natural fireballs. The proponents of the natural meteor, or meteorite, theory presented facts that they had dug out of astronomical journals. Greenish-colored meteors, although not common, had been observed on many occasions. The flat trajectory, which seemed to be so important in proving that the green fireballs were extraterrestrial, was also nothing new. When viewed from certain angles, a meteor can appear to have a flat trajectory. The reason that so many had been seen during December of 1948 and January of 1949 was that the weather had been unusually clear all over the Southwest during this period. Dr. La Paz led the group who believed that the green fireballs were not meteors or meteorites. His argument was derived from the facts that he had gained after many days of research and working with Air Force intelligence teams. He stuck to the points that (1) the trajectory was too flat, (2) the color was too green, and (3) he couldn't locate any fragments even though he had found the spots where they should have hit the earth if they were meteorites. People who were at that meeting have told me that Dr. La Paz's theory was very interesting and that each point was carefully considered. But evidently it wasn't conclusive enough because when the conference broke up, after two days, it was decided that the green fireballs were a natural phenomenon of some kind. It was recommended that this phase of the UFO investigation be given to the Air Force's Cambridge Research Laboratory, since it is the function of this group to study natural phenomena, and that Cambridge set up a project to attempt to photograph the green fireballs and measure their speed, altitude, and size. In the late summer of 1949, Cambridge established Project Twinkle to solve the mystery. The project called for establishing three cinetheodolite stations near White Sands, New Mexico. A cinetheodolite is similar to a 35-mm. movie camera except when you take a photograph of an object you also get a photograph of three dials that show the time the photo was taken, the azimuth angle, and the elevation angle of the camera. If two or more cameras photograph the same object, it is possible to obtain a very accurate measurement of the photographed object's altitude, speed, and size. Project Twinkle was a bust. Absolutely nothing was photographed. Of the three cameras that were planned for the project, only one was available. This one camera was continually being moved from place to place. If several reports came from a certain area, the camera crew would load up their equipment and move to that area, always arriving too late. Any duck hunter can tell you that this is the wrong tactic; if you want to shoot any ducks pick a good place and stay put, let the ducks come to you. The people trying to operate Project Twinkle were having financial and morale trouble. To do a good job they needed more and better equipment and more people, but Air Force budget cuts precluded this. Moral support was free but they didn't get this either. When the Korean War started, Project Twinkle silently died, along with official interest in green fireballs. When I organized Project Blue Book in the summer of 1951 I'd never heard of a green fireball. We had a few files marked "Los Alamos Conference," "Fireballs," "Project Twinkle," etc., but I didn't pay any attention to them. Then one day I was at a meeting in Los Angeles with several other officers from ATIC, and was introduced to Dr. Joseph Kaplan. When he found we were from ATIC, his first question was, "What ever happened to the green fireballs?" None of us had ever heard of them, so he quickly gave us the story. He and I ended up discussing green fireballs. He mentioned Dr. La Paz and his opinion that the green fireballs might be man-made, and although he respected La Paz's professional ability, he just wasn't convinced. But he did strongly urge me to get in touch with Dr. La Paz and hear his side of the story. When I returned to ATIC I spent several days digging into our collection of green fireball reports. All of these reports covered a period from early December 1948 to 1949. As far as Blue Book's files were concerned, there hadn't been a green fireball report for a year and a half. I read over the report on Project Twinkle and the few notes we had on the Los Alamos Conference, and decided that the next time I went to Albuquerque I'd contact Dr. La Paz. I did go to Albuquerque several times but my visits were always short and I was always in a hurry so I didn't get to see him. It was six or eight months later before the subject of green fireballs came up again. I was eating lunch with a group of people at the AEC's Los Alamos Laboratory when one of the group mentioned the mysterious kelly-green balls of fire. The strictly unofficial bull- session-type discussion that followed took up the entire lunch hour and several hours of the afternoon. It was an interesting discussion because these people, all scientists and technicians from the lab, had a few educated guesses as to what they might be. All of them had seen a green fireball, some of them had seen several. One of the men, a private pilot, had encountered a fireball one night while he was flying his Navion north of Santa Fe and he had a vivid way of explaining what he'd seen. "Take a soft ball and paint it with some kind of fluorescent paint that will glow a bright green in the dark," I remember his saying, "then have someone take the ball out about 100 feet in front of you and about 10 feet above you. Have him throw the ball right at your face, as hard as he can throw it. That's what a green fireball looks like." The speculation about what the green fireballs were ran through the usual spectrum of answers, a new type of natural phenomenon, a secret U.S. development, and psychologically enlarged meteors. When the possibility of the green fireballs' being associated with interplanetary vehicles came up, the whole group got serious. They had been doing a lot of thinking about this, they said, and they had a theory. The green fireballs, they theorized, could be some type of unmanned test vehicle that was being projected into our atmosphere from a "spaceship" hovering several hundred miles above the earth. Two years ago I would have been amazed to hear a group of reputable scientists make such a startling statement. Now, however, I took it as a matter of course. I'd heard the same type of statement many times before from equally qualified groups. Turn the tables, they said, suppose that we are going to try to go to a far planet. There would be three phases to the trip: out through the earth's atmosphere, through space, and the re-entry into the atmosphere of the planet we're planning to land on. The first two phases would admittedly present formidable problems, but the last phase, the re-entry phase, would be the most critical. Coming in from outer space, the craft would, for all practical purposes, be similar to a meteorite except that it would be powered and not free-falling. You would have myriad problems associated with aerodynamic heating, high aerodynamic loadings, and very probably a host of other problems that no one can now conceive of. Certain of these problems could be partially solved by laboratory experimentation, but nothing can replace flight testing, and the results obtained by flight tests in our atmosphere would not be valid in another type of atmosphere. The most logical way to overcome this difficulty would be to build our interplanetary vehicle, go to the planet that we were interested in landing on, and hover several hundred miles up. From this altitude we could send instrumented test vehicles down to the planet. If we didn't want the inhabitants of the planet, if it were inhabited, to know what we were doing we could put destruction devices in the test vehicle, or arrange the test so that the test vehicles would just plain burn up at a certain point due to aerodynamic heating. They continued, each man injecting his ideas. Maybe the green fireballs are test vehicles--somebody else's. The regular UFO reports might be explained by the fact that the manned vehicles were venturing down to within 100,000 or 200,000 feet of the earth, or to the altitude at which atmosphere re-entry begins to get critical. I had to go down to the airstrip to get a CARCO Airlines plane back to Albuquerque so I didn't have time to ask a lot of questions that came into my mind. I did get to make one comment. From the conversations, I assumed that these people didn't think the green fireballs were any kind of a natural phenomenon. Not exactly, they said, but so far the evidence that said they were a natural phenomenon was vastly outweighed by the evidence that said they weren't. During the kidney-jolting trip down the valley from Los Alamos to Albuquerque in one of the CARCO Airlines' Bonanzas, I decided that I'd stay over an extra day and talk to Dr. La Paz. He knew every detail there was to know about the green fireballs. He confirmed my findings, that the genuine green fireballs were no longer being seen. He said that he'd received hundreds of reports, especially after he'd written several articles about the mysterious fireballs, but that all of the reported objects were just greenish- colored, common, everyday meteors. Dr. La Paz said that some people, including Dr. Joseph Kaplan and Dr. Edward Teller, thought that the green fireballs were natural meteors. He didn't think so, however, for several reasons. First the color was so much different. To illustrate his point, Dr. La Paz opened his desk drawer and took out a well-worn chart of the color spectrum. He checked off two shades of green; one a pale, almost yellowish green and the other a much more distinct vivid green. He pointed to the bright green and told me that this was the color of the green fireballs. He'd taken this chart with him when he went out to talk to people who had seen the green fireballs and everyone had picked this one color. The pale green, he explained, was the color reported in the cases of documented green meteors. Then there were other points of dissimilarity between a meteor and the green fireballs. The trajectory of the fireballs was too flat. Dr. La Paz explained that a meteor doesn't necessarily have to arch down across the sky, its trajectory can appear to be flat, but not as flat as that of the green fireballs. Then there was the size. Almost always such descriptive words as "terrifying," "as big as the moon," and "blinding" had been used to describe the fireballs. Meteors just aren't this big and bright. No--Dr. La Paz didn't think that they were meteors. Dr. La Paz didn't believe that they were meteorites either. A meteorite is accompanied by sound and shock waves that break windows and stampede cattle. Yet in every case of a green fireball sighting the observers reported that they did not hear any sound. But the biggest mystery of all was the fact that no particles of a green fireball had ever been found. If they were meteorites, Dr. La Paz was positive that he would have found one. He'd missed very few times in the cases of known meteorites. He pulled a map out of his file to show me what he meant. It was a map that he had used to plot the spot where a meteorite had hit the earth. I believe it was in Kansas. The map had been prepared from information he had obtained from dozens of people who had seen the meteorite come flaming toward the earth. At each spot where an observer was standing he'd drawn in the observer's line of sight to the meteorite. From the dozens of observers he had obtained dozens of lines of sight. The lines all converged to give Dr. La Paz a plot of the meteorite's downward trajectory. Then he had been able to plot the spot where it had struck the earth. He and his crew went to the marked area, probed the ground with long steel poles, and found the meteorite. This was just one case that he showed me. He had records of many more similar successful expeditions in his file. Then he showed me some other maps. The plotted lines looked identical to the ones on the map I'd just seen. Dr. La Paz had used the same techniques on these plots and had marked an area where he wanted to search. He had searched the area many times but he had never found anything. These were plots of the path of a green fireball. When Dr. La Paz had finished, I had one last question, "What do you think they are?" He weighed the question for a few seconds--then he said that all he cared to say was that he didn't think that they were a natural phenomenon. He thought that maybe someday one would hit the earth and the mystery would be solved. He hoped that they were a natural phenomenon. After my talk with Dr. La Paz I can well understand his apparent calmness on the night of September 18, 1954, when the newspaper reporter called him to find out if he planned to investigate this latest green fireball report. He was speaking from experience, not indifference, when he said, "But I don't expect to find anything." If the green fireballs are back, I hope that Dr. La Paz gets an answer this time. The story of the UFO now goes back to late January 1949, the time when the Air Force was in the midst of the green fireball mystery. In another part of the country another odd series of events was taking place. The center of activity was a highly secret area that can't be named, and the recipient of the UFO's, which were formations of little lights, was the U.S. Army. The series of incidents started when military patrols who were protecting the area began to report seeing formations of lights flying through the night sky. At first the lights were reported every three or four nights, but inside of two weeks the frequency had stepped up. Before long they were a nightly occurrence. Some patrols reported that they had seen three or four formations in one night. The sightings weren't restricted to the men on patrol. One night, just at dusk, during retreat, the entire garrison watched a formation pass directly over the post parade ground. As usual with UFO reports, the descriptions of the lights varied but the majority of the observers reported a V formation of three lights. As the formation moved through the sky, the lights changed in color from a bluish white to orange and back to bluish white. This color cycle took about two seconds. The lights usually traveled from west to east and made no sound. They didn't streak across the sky like a meteor, but they were "going faster than a jet." The lights were "a little bigger than the biggest star." Once in a while the GI's would get binoculars on them but they couldn't see any more details. The lights just looked bigger. From the time of the first sighting, reports of the little lights were being sent to the Air Force through Army Intelligence channels. The reports were getting to ATIC, but the green fireball activity was taking top billing and no comments went back to the Army about their little lights. According to an Army G-2 major to whom I talked in the Pentagon, this silence was taken to mean that no action, other than sending in reports, was necessary on the part of the Army. But after about two weeks of nightly sightings and no apparent action by the Air Force, the commander of the installation decided to take the initiative and set a trap. His staff worked out a plan in record time. Special UFO patrols would be sent out into the security area and they would be furnished with sighting equipment. This could be the equipment that they normally used for fire control. Each patrol would be sent to a specific location and would set up a command post. Operating out of the command post, at points where the sky could be observed, would be sighting teams. Each team had sighting equipment to measure the elevation and azimuth angle of the UFO. Four men were to be on each team, an instrument man, a timer, a recorder, and a radio operator. All the UFO patrols would be assigned special radio frequencies. The operating procedure would be that when one sighting team spotted a UFO the radio operator would call out his team's location, the location of the UFO in the sky, and the direction it was going. All of the other teams from his patrol would thus know when to look for the UFO and begin to sight on it. While the radio man was reporting, the instrument man on the team would line up the UFO and begin to call out the angles of elevation and azimuth. The timer would call out the time; the recorder would write all of this down. The command post, upon hearing the report of the UFO, would call the next patrol and tell them. They too would try to pick it up. Here was an excellent opportunity to get some concrete data on at least one type of UFO. It was something that should have been done from the start. Speeds, altitudes, and sizes that are estimated just by looking at a UFO are miserably inaccurate. But if you could accurately establish that some type of object was traveling 30,000 miles an hour--or even 3,000 miles an hour--through our atmosphere, the UFO story would be the biggest story since the Creation. The plan seemed foolproof and had the full support of every man who was to participate. For the first time in history every GI wanted to get on the patrols. The plan was quickly written up as a field order, approved, and mimeographed. Since the Air Force had the prime responsibility for the UFO investigation, it was decided that the plan should be quickly co-ordinated with the Air Force, so a copy was rushed to them. Time was critical because every group of nightly reports might be the last. Everything was ready to roll the minute the Air Force said "Go." The Air Force didn't O.K. the plan. I don't know where the plan was killed, or who killed it, but it was killed. Its death caused two reactions. Many people thought that the plan was killed so that too many people wouldn't find out the truth about UFO's. Others thought somebody was just plain stupid. Neither was true. The answer was simply that the official attitude toward UFO's had drastically changed in the past few months. They didn't exist, they couldn't exist. It was the belief at ATIC that the one last mystery, the green fireballs, had been solved a few days before at Los Alamos. The fireballs were meteors and Project Twinkle would prove it. Any further investigation by the Army would be a waste of time and effort. This drastic change in official attitude is as difficult to explain as it was difficult for many people who knew what was going on inside Project Sign to believe. I use the words "official attitude" because at this time UFO's had become as controversial a subject as they are today. All through intelligence circles people had chosen sides and the two UFO factions that exist today were born. On one side was the faction that still believed in flying saucers. These people, come hell or high water, were hanging on to their original ideas. Some thought that the UFO's were interplanetary spaceships. Others weren't quite as bold and just believed that a good deal more should be known about the UFO's before they were so completely written off. These people weren't a bunch of nuts or crackpots either. They ranged down through the ranks from generals and top-grade civilians. On the outside their views were backed up by civilian scientists. On the other side were those who didn't believe in flying saucers. At one time many of them had been believers. When the UFO reports were pouring in back in 1947 and 1948, they were just as sure that the UFO's were real as the people they were now scoffing at. But they had changed their minds. Some of them had changed their minds because they had seriously studied the UFO reports and just couldn't see any evidence that the UFO's were real. But many of them could see the "I don't believe" band wagon pulling out in front and just jumped on. This change in the operating policy of the UFO project was so pronounced that I, like so many other people, wondered if there was a hidden reason for the change. Was it actually an attempt to go underground--to make the project more secretive? Was it an effort to cover up the fact that UFO's were proven to be interplanetary and that this should be withheld from the public at all cost to prevent a mass panic? The UFO files are full of references to the near mass panic of October 30, 1938, when Orson Welles presented his now famous "The War of the Worlds" broadcast. This period of "mind changing" bothered me. Here were people deciding that there was nothing to this UFO business right at a time when the reports seemed to be getting better. From what I could see, if there was any mind changing to be done it should have been the other way, skeptics should have been changing to believers. Maybe I was just playing the front man to a big cover-up. I didn't like it because if somebody up above me knew that UFO's were really spacecraft, I could make a big fool out of myself if the truth came out. I checked into this thoroughly. I spent a lot of time talking to people who had worked on Project Grudge. The anti-saucer faction was born because of an old psychological trait, people don't like to be losers. To be a loser makes one feel inferior and incompetent. On September 23, 1947, when the chief of ATIC sent a letter to the Commanding General of the Army Air Forces stating that UFO's were real, intelligence committed themselves. They had to prove it. They tried for a year and a half with no success. Officers on top began to get anxious and the press began to get anxious. They wanted an answer. Intelligence had tried one answer, the then Top Secret Estimate of the Situation that "proved" that UFO's were real, but it was kicked back. The people on the UFO project began to think maybe the brass didn't consider them too sharp so they tried a new hypothesis: UFO's don't exist. In no time they found that this was easier to prove and it got recognition. Before if an especially interesting UFO report came in and the Pentagon wanted an answer, all they'd get was an "It could be real but we can't prove it." Now such a request got a quick, snappy "It was a balloon," and feathers were stuck in caps from ATIC up to the Pentagon. Everybody felt fine. In early 1949 the term "new look" was well known. The new look in women's fashions was the lower hemlines, in automobiles it was longer lines. In UFO circles the new look was cuss 'em. The new look in UFO's was officially acknowledged on February 11, 1949, when an order was written that changed the name of the UFO project from Project Sign to Project Grudge. The order was supposedly written because the classified name, Project Sign, had been compromised. This was always my official answer to any questions about the name change. I'd go further and say that the names of the projects, first Sign, then Grudge, had no significance. This wasn't true, they did have significance, a lot of it. CHAPTER FIVE The Dark Ages The order of February 11, 1949, that changed the name of Project Sign to Project Grudge had not directed any change in the operating policy of the project. It had, in fact, pointed out that the project was to continue to investigate and evaluate reports of sightings of unidentified flying objects. In doing this, standard intelligence procedures would be used. This normally means the _unbiased_ _evaluation_ of intelligence data. But it doesn't take a great deal of study of the old UFO files to see that standard intelligence procedures were no longer being used by Project Grudge. Everything was being evaluated on the premise that UFO's couldn't exist. No matter what you see or hear, don't believe it. New people took over Project Grudge. ATIC's top intelligence specialists who had been so eager to work on Project Sign were no longer working on Project Grudge. Some of them had drastically and hurriedly changed their minds about UFO's when they thought that the Pentagon was no longer sympathetic to the UFO cause. They were now directing their talents toward more socially acceptable projects. Other charter members of Project Sign had been "purged." These were the people who had refused to change their original opinions about UFO's. With the new name and the new personnel came the new objective, get rid of the UFO's. It was never specified this way in writing but it didn't take much effort to see that this was the goal of Project Grudge. This unwritten objective was reflected in every memo, report, and directive. To reach their objective Project Grudge launched into a campaign that opened a new age in the history of the UFO. If a comparative age in world history can be chosen, the Dark Ages would be most appropriate. Webster's Dictionary defines the Dark Ages as a period of "intellectual stagnation." To one who is intimately familiar with UFO history it is clear that Project Grudge had a two-phase program of UFO annihilation. The first phase consisted of explaining every UFO report. The second phase was to tell the public how the Air Force had solved all the sightings. This, Project Grudge reasoned, would put an end to UFO reports. Phase one had been started by the people of Project Sign. They realized that a great many reports were caused by people seeing balloons or such astronomical bodies as planets, meteors, or stars. They also realized that before they could get to the heart of the UFO problems they had to sift out this type of report. To do this they had called on outside help. Air Weather Service had been asked to screen the reports and check those that sounded like balloons against their records of balloon flights. Dr. J. Allen Hynek, distinguished astrophysicist and head of Ohio State University's Astronomy Department, had been given a contract to sort out those reports that could be blamed on stars, planets, meteors, etc. By early March the Air Weather Service and Dr. Hynek had some positive identifications. According to the old records, with these solutions and those that Sign and Grudge had already found, about 50 per cent of the reported UFO's could now be positively identified as hoaxes, balloons, planets, sundogs, etc. It was now time to start phase two, the publicity campaign. For many months reporters and writers had been trying to reach behind the security wall and get the UFO story from the horse's mouth, but no luck. Some of them were still trying but they were having no success because they were making the mistake of letting it slip that they didn't believe that airline pilots, military pilots, scientists, and just all around solid citizens were having "hallucinations," perpetrating "hoaxes," or being deceived by the "misidentification of common objects." The people of Project Grudge weren't looking for this type of writer, they wanted a writer who would listen to them and write their story. As a public relations officer later told me, "We had a devil of a time. All of the writers who were after saucer stories had made their own investigations of sightings and we couldn't convince them they were wrong." Before long, however, the right man came along. He was Sidney Shallet, a writer for _The_ _Saturday_ _Evening_ _Post_. He seemed to have the prerequisites that were desired, so his visit to ATIC was cleared through the Pentagon. Harry Haberer, a crack Air Force public relations man, was assigned the job of seeing that Shallet got his story. I have heard many times, from both military personnel and civilians, that the Air Force told Shallet exactly what to say in his article--play down the UFO's--don't write anything that even hints that there might be something foreign in our skies. I don't believe that this is the case. I think that he just wrote the UFO story as it was told to him, told to him by Project Grudge. Shallet's article, which appeared in two parts in the April 30 and May 7, 1949, issues of _The_ _Saturday_ _Evening_ _Post_, is important in the history of the UFO and in understanding the UFO problem because it had considerable effect on public opinion. Many people had, with varying degrees of interest, been wondering about the UFO's for over a year and a half. Very few had any definite opinions one way or the other. The feeling seemed to be that the Air Force is working on the problem and when they get the answer we'll know. There had been a few brief, ambiguous press releases from the Air Force but these meant nothing. Consequently when Shallet's article appeared in the _Post_ it was widely read. It contained facts, and the facts had come from Air Force Intelligence. This was the Air Force officially reporting on UFO's for the first time. The article was typical of the many flying saucer stories that were to follow in the later years of UFO history, all written from material obtained from the Air Force. Shallet's article casually admitted that a few UFO sightings couldn't be explained, but the reader didn't have much chance to think about this fact because 99 per cent of the story was devoted to the anti-saucer side of the problem. It was the typical negative approach. I know that the negative approach is typical of the way that material is handed out by the Air Force because I was continually being told to "tell them about the sighting reports we've solved--don't mention the unknowns." I was never ordered to tell this, but it was a strong suggestion and in the military when higher headquarters suggests, you do. Shallet's article started out by psychologically conditioning the reader by using such phrases as "the great flying saucer scare," "rich, full-blown screwiness," "fearsome freaks," and so forth. By the time the reader gets to the meat of the article he feels like a rich, full-blown jerk for ever even thinking about UFO's. He pointed out how the "furor" about UFO reports got so great that the Air Force was "forced" to investigate the reports reluctantly. He didn't mention that two months after the first UFO report ATIC had asked for Project Sign since they believed that UFO's did exist. Nor did it mention the once Top Secret Estimate of the Situation that also concluded that UFO's were real. In no way did the article reflect the excitement and anxiety of the age of Project Sign when secret conferences preceded and followed every trip to investigate a UFO report. This was the Air Force being "forced" into reluctantly investigating the UFO reports. Laced through the story were the details of several UFO sightings; some new and some old, as far as the public was concerned. The original UFO report by Kenneth Arnold couldn't be explained. Arnold, however, had sold his story to _Fate_ magazine and in the same issue of _Fate_ were stories with such titles as "Behind the Etheric Veil" and "Invisible Beings Walk the Earth," suggesting that Arnold's story might fall into the same category. The sightings where the Air Force had the answer had detailed explanations. The ones that were unknowns were mentioned, but only in passing. Many famous names were quoted. The late General Hoyt S. Vanden-berg, then Chief of Staff of the Air Force, had seen a flying saucer but it was just a reflection on the windshield of his B-17. General Lauris Norstad's UFO was a reflection of a star on a cloud, and General Curtis E. Le May found out that one out of six UFO's was a balloon; Colonel McCoy, then chief of ATIC, had seen lots of UFO's. All were reflections from distant airplanes. In other words, nobody who is anybody in the Air Force believes in flying saucers. Figures in the top echelons of the military had spoken. A few hoaxes and crackpot reports rounded out Mr. Shallet's article. The reaction to the article wasn't what the Air Force and ATIC expected. They had thought that the public would read the article and toss it, and all thoughts of UFO's, into the trash can. But they didn't. Within a few days the frequency of UFO reports hit an all- time high. People, both military and civilian, evidently didn't much care what Generals Vandenberg, Norstad, Le May, or Colonel McCoy thought; they didn't believe what they were seeing were hallucinations, reflections, or balloons. What they were seeing were UFO's, whatever UFO's might be. I heard many times from ex-Project Grudge people that Shallet had "crossed" them, he'd vaguely mentioned that there might be a case for the UFO. This made him pro-saucer. A few days after the last installment of the _Post_ article the Air Force gave out a long and detailed press release completely debunking UFO's, but this had no effect. It only seemed to add to the confusion. The one thing that Shallet's article accomplished was to plant a seed of doubt in many people's minds. Was the Air Force telling the truth about UFO's? The public and a large percentage of the military didn't know what was going on behind ATIC's barbed-wire fence but they did know that a lot of reliable people had seen UFO's. Airline pilots are considered responsible people--airline pilots had seen UFO's. Experienced military pilots and ground officers are responsible people--they'd seen UFO's. Scientists, doctors, lawyers, merchants, and plain old Joe Doakes had seen UFO's, and their friends knew that they were responsible people. Somehow these facts and the tone of the _Post_ article didn't quite jibe, and when things don't jibe, people get suspicious. In those people who had a good idea of what was going on behind ATIC's barbed wire, the newspaper reporters and writers with the "usually reliable sources," the _Post_ article planted a bigger seed of doubt. Why the sudden change in policy they wondered? If UFO's were so serious a few months ago, why the sudden debunking? Maybe Shallet's story was a put-up job for the Air Force. Maybe the security had been tightened. Their sources of information were reporting that many people in the military did not quite buy the Shallet article. The seed of doubt began to grow, and some of these writers began to start "independent investigations" to get the "true" story. Research takes time, so during the summer and fall of 1949 there wasn't much apparent UFO activity. As the writers began to poke around for their own facts, Project Grudge lapsed more and more into a period of almost complete inactivity. Good UFO reports continued to come in at the rate of about ten per month but they weren't being verified or investigated. Most of them were being discarded. There are few, if any, UFO reports for the middle and latter part of 1949 in the ATIC files. Only the logbook, showing incoming reports, gives any idea of the activity of this period. The meager effort that was being made was going into a report that evaluated old UFO reports, those received prior to the spring of 1949. Project Grudge _thought_ that they were writing a final report on the UFO's. From the small bits of correspondence and memos that were in the ATIC files, it was apparent that Project Grudge thought that the UFO was on its way out. Any writers inquiring about UFO activity were referred to the debunking press release given out just after the _Post_ article had been published. There was no more to say. Project Grudge thought they were winning the UFO battle; the writers thought that they were covering up a terrific news story--the story that the Air Force knew what flying saucers were and weren't telling. By late fall 1949 the material for several UFO stories had been collected by writers who had been traveling all over the United States talking to people who had seen UFO's. By early winter the material had been worked up into UFO stories. In December the presses began to roll. _True_ magazine "scooped" the world with their story that UFO's were from outer space. The _True_ article, entitled, "The Flying Saucers Are Real," was written by Donald Keyhoe. The article opened with a hard punch. In the first paragraph Keyhoe concluded that after eight months of extensive research he had found evidence that the earth was being closely scrutinized by intelligent beings. Their vehicles were the so- called flying saucers. Then he proceeded to prove his point. His argument was built around the three classics: the Mantell, the Chiles- Whitted, and the Gorman incidents. He took each sighting, detailed the "facts," ripped the official Air Force conclusions to shreds, and presented his own analysis. He threw in a varied assortment of technical facts that gave the article a distinct, authoritative flavor. This, combined with the fact that _True_ had the name for printing the truth, hit the reading public like an 8-inch howitzer. Hours after it appeared in subscribers' mailboxes and on the newsstands, radio and TV commentators and newspapers were giving it a big play. UFO's were back in business, to stay. True was in business too. It is rumored among magazine publishers that Don Keyhoe's article in _True_ was one of the most widely read and widely discussed magazine articles in history. The Air Force had inadvertently helped Keyhoe--in fact, they made his story a success. He and several other writers had contacted the Air Force asking for information for their magazine articles. But, knowing that the articles were pro-saucer, the writers were unceremoniously sloughed off. Keyhoe carried his fight right to the top, to General Sory Smith, Director of the Office of Public Information, but still no dice--the Air Force wasn't divulging any more than they had already told. Keyhoe construed this to mean tight security, the tightest type of security. Keyhoe had one more approach, however. He was an ex-Annapolis graduate, and among his classmates were such people as Admiral Delmar Fahrney, then a top figure in the Navy guided missile program and Admiral Calvin Bolster, the Director of the Office of Naval Research. He went to see them but they couldn't help him. He _knew_ that this meant the real UFO story was big and that it could be only one thing--interplanetary spaceships or earthly weapons--and his contacts denied they were earthly weapons. He played this security angle in his _True_ article and in a later book, and it gave the story the needed punch. But the Air Force wasn't trying to cover up. It was just that they didn't want Keyhoe or any other saucer fans in their hair. They couldn't be bothered. They didn't believe in flying saucers and couldn't feature anybody else believing. Believing, to the people in ATIC in 1949, meant even raising the possibility that there might be something to the reports. The Air Force had a plan to counter the Keyhoe article, or any other story that might appear. The plan originated at ATIC. It called for a general officer to hold a short press conference, flash his stars, and speak the magic words "hoaxes, hallucinations, and the misidentification of known objects," _True_, Keyhoe and the rest would go broke trying to peddle their magazines. The _True_ article did come out, the general spoke, the public laughed, and Keyhoe and _True_ got rich. Only the other magazines that had planned to run UFO stories, and that were scooped by _True_, lost out. Their stories were killed--they would have been an anti-climax to Keyhoe's potboiler. The Air Force's short press conference was followed by a press release. On December 27, 1949, it was announced that Project Grudge had been closed out and the final report on UFO's would be released to the press in a few days. When it was released it caused widespread interest because, supposedly, this was all that the Air Force knew about UFO's. Once again, instead of throwing large amounts of cold water on the UFO's, it only caused more confusion. The report was officially titled "Unidentified Flying Objects-- Project Grudge," Technical Report No. 102-AC-49/15-100. But it was widely referred to as the Grudge Report. The Grudge Report was a typical military report. There was the body of the report, which contained the short discussion, conclusions, and recommendations. Then there were several appendixes that were supposed to substantiate the conclusions and recommendations made in the report. One of the appendixes was the final report of Dr. J. Allen Hynek, Project Grudge's contract astronomer. Dr. Hynek and his staff had studied 237 of the best UFO reports. They had spent several months analyzing each report. By searching through astronomical journals and checking the location of various celestial bodies, they found that some UFO's could be explained. Of the 237 reports he and his staff examined, 32 per cent could be explained astronomically. The Air Force Air Weather Service and the Air Force Cambridge Research Laboratory had sifted the reports for UFO's that might have been balloons. These two organizations had data on the flights of both the regular weather balloons and the huge, high-flying skyhooks. They wrote off 12 per cent of the 237 UFO reports under study as balloons. This left 56 per cent still unknown. By weeding out the hoaxes, the reports that were too nebulous to evaluate, and reports that could well be misidentified airplanes, Project Grudge disposed of another 33 per cent of the reports. This left 23 per cent that fell in the "unknown" category. There were more appendixes. The Rand Corporation, one of the most unpublicized yet highly competent contractors to the Air Force, looked over the reports and made the statement, "We have found nothing which would seriously controvert simple rational explanations of the various phenomena in terms of balloons, conventional aircraft, planets, meteors, bits of paper, optical illusions, practical jokers, psychopathological reporters, and the like." But Rand's comment didn't help a great deal because they didn't come up with any solutions to any of the 23 per cent unknown. The Psychology Branch of the Air Force's Aeromedical Laboratory took a pass at the psychological angles. They said, "there are sufficient psychological explanations for the reports of unidentified objects to provide plausible explanations for reports not otherwise explainable." They pointed out that some people have "spots in front of their eyes" due to minute solid particles that float about in the fluids of the eye and cast shadows on the retina. Then they pointed out that some people are just plain nuts. Many people who read the Grudge Report took these two points to mean that all UFO observers either had spots in front of their eyes or were nuts. They broke the reports down statistically. The people who wrote the report found that over 70 per cent of the people making sightings reported a light- colored object. (This I doubt, but that's what the report said.) They said a big point of these reports of light-colored objects was that any high-flying object will appear to be dark against the sky. For this reason the UFO's couldn't be real. I suggest that the next time you are outdoors and see a bomber go over at high altitude you look at it closely. Unless it's painted a dark color it won't look dark. The U.S. Weather Bureau wrote an extremely comprehensive and interesting report on all types of lightning. It was included in the Grudge Report but contained a note: "None of the recorded incidents appear to have been lightning." There was one last appendix. It was entitled "Summary of the Evaluation of Remaining Reports." What the title meant was, We have 23 per cent of the reports that we can't explain but we have to explain them because we don't believe in flying saucers. This appendix contributed greatly to the usage of the analogy to the Dark Ages, the age of "intellectual stagnation." This appendix was important--it was the meat of the whole report. Every UFO sighting had been carefully checked, and those with answers had been sifted out. Then the ones listed in "Summary of the Evaluation of Remaining Reports" should be the best UFO reports--the ones with no answers. This was the appendix that the newsmen grabbed at when the Grudge Report was released. It contained the big story. But if you'll check back through old newspaper files you will hardly find a mention of the Grudge Report. I was told that reporters just didn't believe it when I tried to find out why the Grudge Report hadn't been mentioned in the newspapers. I got the story from a newspaper correspondent in Washington whom I came to know pretty well and who kept me filled in on the latest UFO scuttlebutt being passed around the Washington press circles. He was one of those humans who had a brain like a filing cabinet; he could remember everything about everything. UFO's were a hobby of his. He remembered when the Grudge Report came out; in fact, he'd managed to get a copy of his own. He said the report had been quite impressive, but only in its ambiguousness, illogical reasoning, and very apparent effort to write off all UFO reports at any cost. He, personally, thought that it was a poor attempt to put out a "fake" report, full of misleading information, to cover up the real story. Others, he told me, just plainly and simply didn't know what to think--they were confused. And they had every right to be confused. As an example of the way that many of the better reports of the 1947- 49 period were "evaluated" let's take the report of a pilot who tangled with a UFO near Washington, D.C., on the night of November 18, 1948. At about 9:45 EST I noticed a light moving generally north to south over Andrews AFB. It appeared to be one continuous, glowing white light. I thought it was an aircraft with only one landing light so I moved in closer to check, as I wanted to get into the landing pattern. I was well above landing traffic altitude at this time. As I neared the light I noticed that it was not another airplane. Just then it began to take violent evasive action so I tried to close on it. I made first contact at 2,700 feet over the field. I switched my navigation lights on and off but got no answer so I went in closer-- but the light quickly flew up and over my airplane. I then tried to close again but the light turned. I tried to turn inside of its turn and, at the same time, get the light between the moon and me, but even with my flaps lowered I couldn't turn inside the light. I never did manage to get into a position where the light was silhouetted against the moon. I chased the light up and down and around for about 10 minutes, then as a last resort I made a pass and turned on my landing lights. Just before the object made a final tight turn and headed for the coast I saw that it was a dark gray oval-shaped object, smaller than my T-6. I couldn't tell if the light was on the object or if the whole object had been glowing. Two officers and a crew chief, a master sergeant, completely corroborated the pilot's report. They had been standing on the flight line and had witnessed the entire incident. The Air Weather Service, who had been called in as experts on weather balloons, read this report. They said, "Definitely not a balloon." Dr. Hynek said, "No astronomical explanation." It wasn't another airplane and it wasn't a hallucination. But Project Grudge had an answer, it _was_ a weather balloon. There was no explanation as to why they had so glibly reversed the decision of the Air Weather Service. There was an answer for every report. From the 600 pages of appendixes, discussions of the appendixes, and careful studies of UFO reports, it was concluded that: Evaluation of reports of unidentified flying objects constitute no direct threat to the national security of the United States. Reports of unidentified flying objects are the result of: A mild form of mass hysteria or "war nerves." Individuals who fabricate such reports to perpetrate a hoax or seek publicity. Psychopathological persons. Misidentification of various conventional objects. It was recommended that Project Grudge be "reduced in scope" and that only "those reports clearly indicating realistic technical applications" be sent to Grudge. There was a note below these recommendations. It said, "It is readily apparent that further study along present lines would only confirm the findings presented herein." Somebody read the note and concurred because with the completion and approval of the Grudge Report, Project Grudge folded. People could rant and rave, see flying saucers, pink elephants, sea serpents, or Harvey, but it was no concern of ATIC's. CHAPTER SIX The Presses Roll--The Air Force Shrugs The Grudge Report was supposedly not for general distribution. A few copies were sent to the Air Force Press Desk in the Pentagon and reporters and writers could come in and read it. But a good many copies did get into circulation. The Air Force Press Room wasn't the best place to sit and study a 600-page report, and a quick glance at the report showed that it required some study--if no more than to find out what the authors were trying to prove--so several dozen copies got into circulation. I know that these "liberated" copies of the Grudge Report had been thoroughly studied because nearly every writer who came to ATIC during the time that I was in charge of Project Blue Book carried a copy. Since the press had some questions about the motives behind releasing the Grudge Report, it received very little publicity while the writers put out feelers. Consequently in early 1950 you didn't read much about flying saucers. Evidently certain people in the Air Force thought this lull in publicity meant that the UFO's had finally died because Project Grudge was junked. All the project files, hundreds of pounds of reports, memos, photos, sketches, and other assorted bits of paper were unceremoniously yanked out of their filing cabinets, tied up with string, and chucked into an old storage case. I would guess that many reports ended up as "souvenirs" because a year later, when I exhumed these files, there were a lot of reports missing. About this time the official Air Force UFO project had one last post- death muscular spasm. The last bundle of reports had just landed on top of the pile in the storage case when ATIC received a letter from the Director of Intelligence of the Air Force. In official language it said, "What gives?" There had been no order to end Project Grudge. The answer went back that Project Grudge had not been disbanded; the project functions had been transferred and it was no longer a "special" project. From now on UFO reports would be processed through normal intelligence channels along with other intelligence reports. To show good faith ATIC requested permission to issue a new Air Force-wide bulletin which was duly mimeographed and disseminated. In essence it said that Air Force Headquarters had directed ATIC to continue to collect and evaluate reports of unidentified flying objects. It went on to explain that most UFO reports were trash. It pointed out the findings of the Grudge Report in such strong language that by the time the recipient of the bulletin had finished reading it, he would be ashamed to send in a report. To cinch the deal the bulletins must have been disseminated only to troops in Outer Mongolia because I never found anyone in the field who had ever received a copy. As the Air Force UFO-investigating activity dropped to nil, the press activity skyrocketed to a new peak. A dozen people took off to dig up their own UFO stories and to draw their own conclusions. After a quiet January, _True_ again clobbered the reading public. This time it was a story in the March 1950 issue and it was entitled, "How Scientists Tracked Flying Saucers." It was written by none other than the man who was at that time in charge of a team of Navy scientists at the super hush-hush guided missile test and development area, White Sands Proving Ground, New Mexico. He was Commander R. B. McLaughlin, an Annapolis graduate and a Regular Navy officer. His story had been cleared by the military and was in absolute, 180- degree, direct contradiction to every press release that had been made by the military in the past two years. Not only did the commander believe that he had proved that UFO's were real but that he knew what they were. "I am convinced," he wrote in the _True_ article, "that it," referring to a UFO he had seen at White Sands, "was a flying saucer, and further, that these disks are spaceships from another planet, operated by animate, intelligent beings." On several occasions during 1948 and 1949, McLaughlin or his crew at the White Sands Proving Ground had made good UFO sightings. The best one was made on April 24, 1949, when the commander's crew of engineers, scientists, and technicians were getting ready to launch one of the huge 100-foot-diameter skyhook balloons. It was 10:30A.M. on an absolutely clear Sunday morning. Prior to the launching, the crew had sent up a small weather balloon to check the winds at lower levels. One man was watching the balloon through a theodolite, an instrument similar to a surveyor's transit built around a 25-power telescope, one man was holding a stop watch, and a third had a clipboard to record the measured data. The crew had tracked the balloon to about 10,000 feet when one of them suddenly shouted and pointed off to the left. The whole crew looked at the part of the sky where the man was excitedly pointing, and there was a UFO. "It didn't appear to be large," one of the scientists later said, "but it was plainly visible. It was easy to see that it was elliptical in shape and had a 'whitish-silver color.'" After taking a split second to realize what they were looking at, one of the men swung the theodolite around to pick up the object, and the timer reset his stop watch. For sixty seconds they tracked the UFO as it moved toward the east. In about fifty-five seconds it had dropped from an angle of elevation of 45 degrees to 25 degrees, then it zoomed upward and in a few seconds it was out of sight. The crew heard no sound and the New Mexico desert was so calm that day that they could have heard "a whisper a mile away." When they reduced the data they had collected, McLaughlin and crew found out that the UFO had been traveling 4 degrees per second. At one time during the observed portion of its flight, the UFO had passed in front of a range of mountains that were visible to the observers. Using this as a check point, they estimated the size of the UFO to be 40 feet wide and 100 feet long, and they computed that the UFO had been at an altitude of 296,000 feet, or _56_ miles, when they had first seen it, and that it was traveling 7 miles per second. This wasn't the only UFO sighting made by White Sands scientists. On April 5, 1948, another team watched a UFO for several minutes as it streaked across the afternoon sky in a series of violent maneuvers. The disk-shaped object was about a fifth the size of a full moon. On another occasion the crew of a C-47 that was tracking a skyhook balloon saw two similar UFO's come loping in from just above the horizon, circle the balloon, which was flying at just under 90,000 feet, and rapidly leave. When the balloon was recovered it was ripped. I knew the two pilots of the C-47; both of them now believe in flying saucers. And they aren't alone; so do the people of the Aeronautical Division of General Mills who launch and track the big skyhook balloons. These scientists and engineers all have seen UFO's and they aren't their own balloons. I was almost tossed out of the General Mills offices into a cold January Minneapolis snowstorm for suggesting such a thing--but that comes later in our history of the UFO. I don't know what these people saw. There has been a lot of interest generated by these sightings because of the extremely high qualifications and caliber of the observers. There is some legitimate doubt as to the accuracy of the speed and altitude figures that McLaughlin's crew arrived at from the data they measured with their theodolite. This doesn't mean much, however. Even if they were off by a factor of 100 per cent, the speeds and altitudes would be fantastic, and besides they looked at the UFO through a 25-power telescope and swore that it was a flat, oval-shaped object. Balloons, birds, and airplanes aren't flat and oval-shaped. Astrophysicist Dr. Donald Menzel, in a book entitled _Flying_ _Saucers_, says they saw a refracted image of their own balloon caused by an atmospheric phenomenon. Maybe he is right, but the General Mills people don't believe it. And their disagreement is backed up by years of practical experience with the atmosphere, its tricks and its illusions. When the March issue of _True_ magazine carrying Commander McLaughlin's story about how the White Sands Scientists had tracked UFO's reached the public, it stirred up a hornets' nest. Donald Keyhoe's article in the January _True_ had converted many people but there were still a few heathens. The fact that government scientists had seen UFO's, and were admitting it, took care of a large percentage of these heathens. More and more people were believing in flying saucers. The Navy had no comment to make about the sightings, but they did comment on McLaughlin. It seems that several months before, at the suggestion of a group of scientists at White Sands, McLaughlin had carefully written up the details of the sightings and forwarded them to Washington. The report contained no personal opinions, just facts. The comments on McLaughlin's report had been wired back to White Sands from Washington and they were, "What are you drinking out there?" A very intelligent answer--and it came from an admiral in the Navy's guided missile program. By the time his story was published, McLaughlin was no longer at White Sands; he was at sea on the destroyer _Bristol_. Maybe he answered the admiral's wire. The Air Force had no comment to make on McLaughlin's story. People at ATIC just shrugged and smiled as they walked by the remains of Project Grudge, and continued to "process UFO reports through regular intelligence channels." In early 1950 the UFO's moved down to Mexico. The newspapers were full of reports. Tourists were bringing back more saucer stories than hand-tooled, genuine leather purses. _Time_ reported that pickpockets were doing a fabulous business working the sky-gazing crowds that gathered when a _plativolo_ was seen. Mexico's Department of National Defense reported that there had been some good reports but that the stories of finding crashed saucers weren't true. On March 8 one of the best UFO sightings of 1950 took place right over ATIC. About midmorning on this date a TWA airliner was coming in to land at the Dayton Municipal Airport. As the pilot circled to get into the traffic pattern, he and his copilot saw a bright light hovering off to the southeast. The pilot called the tower operators at the airport to tell them about the light, but before he could say anything, the tower operators told him they were looking at it too. They had called the operations office of the Ohio Air National Guard, which was located at the airport, and while the tower operators were talking, an Air Guard pilot was running toward an F-51, dragging his parachute, helmet, and oxygen mask. I knew the pilot, and he later told me, "I wanted to find out once and for all what these screwy flying saucer reports were all about." While the F-51 was warming up, the tower operators called ATIC and told them about the UFO and where to look to see it. The people at ATIC rushed out and there it was--an extremely bright light, much brighter and larger than a star. Whatever it was, it was high because every once in a while it would be blanked out by the thick, high, scattered clouds that were in the area. While the group of people were standing in front of ATIC watching the light, somebody ran in and called the radar lab at Wright Field to see if they had any radar "on the air." The people in the lab said that they didn't have, but they could get operational in a hurry. They said they would search southeast of the field with their radar and suggested that ATIC send some people over. By the time the ATIC people arrived at the radar lab the radar was on the air and had a target in the same position as the light that everyone was looking at. The radar was also picking up the Air Guard F-51 and an F-51 that had been scrambled from Wright- Patterson. The pilots of the Air Guard '51 and the Wright-Patterson '51 could both see the UFO, and they were going after it. The master sergeant who was operating the radar called the F-51's on the radio, got them together and started to vector them toward the target. As the two airplanes climbed they kept up a continual conversation with the radar operator to make sure they were all after the same thing. For several minutes they could clearly see the UFO, but when they reached about 15,000 feet, the clouds moved in and they lost it. The pilots made a quick decision; since radar showed that they were getting closer to the target, they decided to spread out to keep from colliding with one another and to go up through the clouds. They went on instruments and in a few seconds they were in the cloud. It was much worse than they'd expected; the cloud was thick, and the airplanes were icing up fast. An F-51 is far from being a good instrument ship, but they stayed in their climb until radar called and said that they were close to the target; in fact, almost on it. The pilots had another hurried radio conference and decided that since the weather was so bad they'd better come down. If a UFO, or something, was in the clouds, they'd hit it before they could see it. So they made a wise decision; they dropped the noses of their airplanes and dove back down into the clear. They circled awhile but the clouds didn't break. In a few minutes the master sergeant on the radar reported that the target was fading fast. The F-51's went in and landed. When the target faded on the radar, some of the people went outside to visually look for the UFO, but it was obscured by clouds, and the clouds stayed for an hour. When it finally did clear for a few minutes, the UFO was gone. A conference was held at ATIC that afternoon. It included Roy James, ATIC's electronics specialist and expert on radar UFO's. Roy had been over at the radar lab and had seen the UFO on the scope but neither the F-51 pilots nor the master sergeant who operated the radar were at the conference. The records show that at this meeting a unanimous decision was reached as to the identity of the UFO's. The bright light was Venus since Venus was in the southeast during midmorning on March 8, 1950, and the radar return was caused by the ice-laden cloud that the F-51 pilots had encountered. Ice-laden clouds can cause a radar return. The group of intelligence specialists at the meeting decided that this was further proved by the fact that as the F-51's approached the center of the cloud their radar return appeared to approach the UFO target on the radarscope. They were near the UFO and near ice, so the UFO must have been ice. The case was closed. I had read the report of this sighting but I hadn't paid too much attention to it because it had been "solved." But one day almost two years later I got a telephone call at my office at Project Blue Book. It was a master sergeant, the master sergeant who had been operating the radar at the lab. He'd just heard that the Air Force was again seriously investigating UFO's and he wanted to see what had been said about the Dayton Incident. He came over, read the report, and violently disagreed with what had been decided upon as the answer. He said that he'd been working with radar before World War II; he'd helped with the operational tests on the first microwave warning radars developed early in the war by a group headed by Dr. Luis Alvarez. He said that what he saw on that radarscope was no ice cloud; it was some type of aircraft. He'd seen every conceivable type of weather target on radar, he told me; thunderstorms, ice-laden clouds, targets caused by temperature inversions, and the works. They all had similar characteristics--the target was "fuzzy" and varied in intensity. But in this case the target was a good, solid return and he was convinced that it was caused by a good, solid object. And besides, he said, when the target began to fade on his scope he had raised the tilt of the antenna and the target came back, indicating that whatever it was, it was climbing. Ice-laden clouds don't climb, he commented rather bitterly. Nor did the pilot of one of the F-51's agree with the ATIC analysis. The pilot who had been leading the two-ship flight of F-51's on that day told me that what he saw was no planet. While he and his wing man were climbing, and before the clouds obscured it, they both got a good look at the UFO, and it was getting bigger and more distinct all the time. As they climbed, the light began to take on a shape; it was definitely round. And if it had been Venus it should have been in the same part of the sky the next day, but the pilot said that he'd looked and it wasn't there. The ATIC report doesn't mention this point. I remember asking him a second time what the UFO looked like; he said, "huge and metallic"--shades of the Mantell Incident. The Dayton Incident didn't get much of a play from the press because officially it wasn't an unknown and there's nothing intriguing about an ice cloud and Venus. There were UFO reports in the newspapers, however. One story that was widely printed was about a sighting at the naval air station at Dallas, Texas. Just before noon on March 16, Chief Petty Officer Charles Lewis saw a disk-shaped UFO come streaking across the sky and buzz a high-flying B-36. Lewis first saw the UFO coming in from the north, lower than the B-36; then he saw it pull up to the big bomber as it got closer. It hovered under the B-36 for an instant, then it went speeding off and disappeared. When the press inquired about the incident, Captain M. A. Nation, commander of the air station, vouched for his chief and added that the base tower operators had seen and reported a UFO to him about ten days before. This story didn't run long because the next day a bigger one broke when the sky over the little town of Farmington, New Mexico, about 170 miles northwest of Albuquerque, was literally invaded by UFO's. Every major newspaper carried the story. The UFO's had apparently been congregating over the four corners area for two days because several people had reported seeing UFO's on March 15 and 16. But the seventeenth was the big day, every saucer this side of Polaris must have made a successful rendezvous over Farmington, because on that day most of the town's 3,600 citizens saw the mass fly-by. The first reports were made at 10:15A.M.; then for an hour the air was full of flying saucers. Estimates of the number varied from a conservative 500 to "thousands." Most all the observers said the UFO's were saucer- shaped, traveled at almost unbelievable speeds, and didn't seem to have any set flight path. They would dart in and out and seemed to avoid collisions only by inches. There was no doubt that they weren't hallucinations because the mayor, the local newspaper staff, ex- pilots, the highway patrol, and every type of person who makes up a community of 3,600 saw them. I've talked to several people who were in Farmington and saw this now famous UFO display of St. Patrick's Day, 1950. I've heard dozens of explanations--cotton blowing in the wind, bugs' wings reflecting sunlight, a hoax to put Farmington on the map, and real honest-to- goodness flying saucers. One explanation was never publicized, however, and if there is an explanation, it is the best. Under certain conditions of extreme cold, probably 50 to 60 degrees below zero, the plastic bag of a skyhook balloon will get very brittle, and will take on the characteristics of a huge light bulb. If a sudden gust of wind or some other disturbance hits the balloon, it will shatter into a thousand pieces. As these pieces of plastic float down and are carried along by the wind, they could look like thousands of flying saucers. On St. Patrick's Day a skyhook balloon launched from Holloman AFB, adjacent to the White Sands Proving Ground, did burst near Farmington, and it was cold enough at 60,000 feet to make the balloon brittle. True, the people at Farmington never found any pieces of plastic, but the small pieces of plastic are literally as light as feathers and could have floated far beyond the city. The next day, on March 18, the Air Force, prodded by the press, shrugged and said, "There's nothing to it," but they had no explanation. _True_ magazine came through for a third time when their April issue, which was published during the latter part of March 1950, carried a roundup of UFO photos. They offered seven photos as proof that UFO's existed. It didn't take a photo-interpretation expert to tell that all seven could well be of doubtful lineage, nevertheless the collection of photos added fuel to the already smoldering fire. The U.S. public was hearing a lot about flying saucers and all of it was on the pro side. For somebody who didn't believe in the things, the public thought that the Air Force was being mighty quiet. The subject took on added interest on the night of March 26, when a famous news commentator said the UFO's were from Russia. The next night Henry J. Taylor, in a broadcast from Dallas, Texas, said that the UFO's were Uncle Sam's own. He couldn't tell all he knew, but a flying saucer had been found on the beach near Galveston, Texas. It had USAF markings. Two nights later a Los Angeles television station cut into a regular program with a special news flash; later in the evening the announcer said they would show the first photos of the real thing, our military's flying saucer. The photos turned out to be of the Navy XF- 5-U, a World War II experimental aircraft that never flew. The public was now thoroughly confused. By now the words "flying saucer" were being batted around by every newspaper reporter, radio and TV newscaster, comedian, and man on the street. Some of the comments weren't complimentary, but as Theorem I of the publicity racket goes, "It doesn't make any difference what's said as long as the name's spelled right." Early in April the publication that is highly revered by so many, _U.S._ _News_ _and_ _World_ _Report_, threw in their lot. The UFO's belonged to the Navy. Up popped the old non-flying XF-5-U again. Events drifted back to normal when Edward R. Murrow made UFO's the subject of one of his TV documentaries. He took his viewers around the U.S., talked to Kenneth Arnold, of original UFO fame, by phone and got the story of Captain Mantell's death from a reporter "who was there." Sandwiched in between accounts of actual UFO sightings were the pro and con opinions of top Washington brass, scientists, and the man on the street. Even the staid New York _Times_, which had until now stayed out of UFO controversy, broke down and ran an editorial entitled, "Those Flying Saucers--Are They or Aren't They?" All of this activity did little to shock the military out of their dogma. They admitted that the UFO investigation really hadn't been discontinued. "Any substantial reports of any unusual aerial phenomena would be processed through normal intelligence channels," they told the press. Ever since July 4, 1947, ten days after the first flying saucer report, airline pilots had been reporting that they had seen UFO's. But the reports weren't frequent--maybe one every few months. In the spring of 1950 this changed, however, and the airline pilots began to make more and more reports--good reports. The reports went to ATIC but they didn't receive much attention. In a few instances there was a semblance of an investigation but it was halfhearted. The reports reached the newspapers too, and here they received a great deal more attention. The reports were investigated, and the stories checked and rechecked. When airline crews began to turn in one UFO report after another, it was difficult to believe the old "hoax, hallucination, and misidentification of known objects" routine. In April, May, and June of 1950 there were over thirty-five good reports from airline crews. One of these was a report from a Chicago and Southern crew who were flying a DC-3 from Memphis to Little Rock, Arkansas, on the night of March 31. It was an exceptionally clear night, no clouds or haze, a wonderful night to fly. At exactly nine twenty-nine by the cockpit clock the pilot, a Jack Adams, noticed a white light off to his left. The copilot, G. W. Anderson, was looking at the chart but out of the corner of his eye he saw the pilot lean forward and look out the window, so he looked out too. He saw the light just as the pilot said, "What's that?" The copilot's answer was classic: "No, not one of those things." Both pilots had only recently voiced their opinions regarding the flying saucers and they weren't complimentary. As they watched the UFO, it passed across the nose of their DC-3 and they got a fairly good look at it. Neither the pilot nor the copilot was positive of the object's shape because it was "shadowy" but they assumed it was disk-shaped because of the circular arrangement of eight or ten "portholes," each one glowing from a strong bluish-white light that seemed to come from the inside of whatever it was that they saw. The UFO also had a blinking white light on top, a fact that led many people to speculate that this UFO was another airliner. But this idea was quashed when it was announced that there were no other airliners in the area. The crew of the DC-3, when questioned on this possibility, were definite in their answers. If it had been another airplane, they could have read the number, seen the passengers, and darn near reached out and slugged the pilot for getting so close to them. About a month later, over northern Indiana, TWA treated all the passengers of one of their DC-3 nights to a view of a UFO that looked like a "big glob of molten metal." The official answer for this incident is that the huge orange-red UFO was nothing more than the light from the many northern Indiana blast furnaces reflecting a haze layer. Could be, but the pilots say no. There were similar sightings in North Korea two years later--and FEAF Bomber Command had caused a shortage of blast furnaces in North Korea. UFO sightings by airline pilots always interested me as much as any type of sighting. Pilots in general should be competent observers simply because they spend a large part of their lives looking around the sky. And pilots do look; one of the first things an aviation cadet is taught is to "Keep your head on a swivel"; in other words, keep looking around the sky. Of all the pilots, the airline pilots are the cream of this group of good observers. Possibly some second lieutenant just out of flying school could be confused by some unusual formation of ground lights, a meteor, or a star, but airline pilots have flown thousands of hours or they wouldn't be sitting in the left seat of an airliner, and they should be familiar with a host of unusual sights. One afternoon in February 1953 I had an opportunity to further my study of UFO sightings by airline pilots. I had been out at Air Defense Command Headquarters in Colorado Springs and was flying back East on a United Airlines DC-6. There weren't many passengers on the airplane that afternoon but, as usual, the captain came strolling back through the cabin to chat. When he got to me he sat down in the next seat. We talked a few minutes; then I asked him what he knew about flying saucers. He sort of laughed and said that a dozen people a week asked that question, but when I told him who I was and why I was interested, his attitude changed. He said that he'd never seen a UFO but he knew a lot of pilots on United who had. One man, he told me, had seen one several years ago. He'd reported it but he had been sloughed off like the rest. But he was so convinced that he'd seen something unusual that he'd gone out and bought a Leica camera with a 105-mm. telephoto lens, learned how to use it, and now he carried it religiously during his flights. There was a lull in the conversation, then the captain said, "Do you really want to get an opinion about flying saucers?" I said I did. "O.K.," I remember his saying, "how much of a layover do you have in Chicago?" I had about two hours. "All right, as soon as we get to Chicago I'll meet you at Caffarello's, across the street from the terminal building. I'll see who else is in and I'll bring them along." I thanked him and he went back up front. I waited around the bar at Caffarello's for an hour. I'd just about decided that he wasn't going to make it and that I'd better get back to catch my flight to Dayton when he and three other pilots came in. We got a big booth in the coffee shop because he'd called three more off-duty pilots who lived in Chicago and they were coming over too. I don't remember any of the men's names because I didn't make any attempt to. This was just an informal bull session and not an official interrogation, but I really got the scoop on what airline pilots think about UFO's. First of all they didn't pull any punches about what they thought about the Air Force and its investigation of UFO reports. One of the men got right down to the point: "If I saw a flying saucer flying wing-tip formation with me and could see little men waving--even if my whole load of passengers saw it--I wouldn't report it to the Air Force." Another man cut in, "Remember the thing Jack Adams said he saw down by Memphis?" I said I did. "He reported that to the Air Force and some red-hot character met him in Memphis on his next trip. He talked to Adams a few minutes and then told him that he'd seen a meteor. Adams felt like a fool. Hell, I know Jack Adams well and he's the most conservative guy I know. If he said he saw something with glowing portholes, he saw something with glowing portholes--and it wasn't a meteor." Even though I didn't remember the pilots' names I'll never forget their comments. They didn't like the way the Air Force had handled UFO reports and I was the Air Force's "Mr. Flying Saucer." As quickly as one of the pilots would set me up and bat me down, the next one grabbed me off the floor and took his turn. But I couldn't complain too much; I'd asked for it. I think that this group of seven pilots pretty much represented the feelings of a lot of the airline pilots. They weren't wide-eyed space fans, but they and their fellow pilots had seen something and whatever they'd seen weren't hallucinations, mass hysteria, balloons, or meteors. Three of the men at the Caffarello conference had seen UFO's or, to use their terminology, they had seen something they couldn't identify as a known object. Two of these men had seen odd lights closely following their airplanes at night. Both had checked and double- checked with CAA, but no other aircraft was in the area. Both admitted, however, that they hadn't seen enough to class what they'd seen as good UFO sighting. But the third man had a lulu. If I recall correctly, this pilot was flying for TWA. One day in March 1952 he, his copilot, and a third person who was either a pilot deadheading home or another crew member, I don't recall which, were flying a C-54 cargo airplane from Chicago to Kansas City. At about 2:30P.M. the pilot was checking in with the CAA radio at Kirksville, Missouri, flying 500 feet on top of a solid overcast. While he was talking he glanced out at his No. 2 engine, which had been losing oil. Directly in line with it, and a few degrees above, he saw a silvery, disk-shaped object. It was too far out to get a really good look at it, yet it was close enough to be able definitely to make out the shape. The UFO held its relative position with the C-54 for five or six minutes; then the pilot decided to do a little on-the-spot investigating himself. He started a gradual turn toward the UFO and for about thirty seconds he was getting closer, but then the UFO began to make a left turn. It had apparently slowed down because they were still closing on it. About this time the copilot decided that the UFO was a balloon; it just looked as if the UFO was turning. The pilot agreed halfway--and since the company wasn't paying them to intercept balloons, they got back on their course to Kansas City. They flew on for a few more minutes with "the darn thing" still off to their left. If it was a balloon, they should be leaving it behind, the pilot recalled thinking to himself; if they made a 45-degree right turn, the "balloon" shouldn't stay off the left wing; it should drop 'way behind. So they made a 45-degree right turn, and although the "balloon" dropped back a little bit, it didn't drop back far enough to be a balloon. It seemed to put on speed to try to make a turn outside of the C-54's turn. The pilot continued on around until he'd made a tight 360-degree turn, and the UFO had followed, staying outside. They could not judge its speed, not knowing how far away it was, but to follow even a C-54 around in a 360-degree turn and to stay outside all of the time takes a mighty speedy object. This shot the balloon theory right in the head. After the 360-degree turn the UFO seemed to be gradually losing altitude because it was getting below the level of the wings. The pilot decided to get a better look. He asked for full power on all four engines, climbed several thousand feet, and again turned into the UFO. He put the C-54 in a long glide, headed directly toward it. As they closed in, the UFO seemed to lose altitude a little faster and "sank" into the top of the overcast. Just as the C-54 flashed across the spot where the UFO had disappeared, the crew saw it rise up out of the overcast off their right wing and begin to climb so fast that in several seconds it was out of sight. Both the pilot and copilot wanted to stay around and look for it but No. 2 engine had started to act up soon after they had put on full power for the climb, and they decided that they'd better get into Kansas City. I missed my Dayton flight but I heard a good UFO story. What had the two pilots and their passenger seen? We kicked it around plenty that afternoon. It was no balloon. It wasn't another airplane because when the pilot called Kirksville Radio he'd asked if there were any airplanes in the area. It might possibly have been a reflection of some kind except that when it "sank" into the overcast the pilot said it looked like something sinking into an overcast--it just didn't disappear as a reflection would. Then there was the sudden reappearance off the right wing. These are the types of things you just can't explain. What did the pilots think it was? Three were sold that the UFO's were interplanetary spacecraft, one man was convinced that they were some U.S. "secret weapon," and three of the men just shook their heads. So did I. We all agreed on one thing--this pilot had seen something and it was something highly unusual. The meeting broke up about 9:00P.M. I'd gotten the personal and very candid opinion of seven airline captains, and the opinions of half a hundred more airline pilots had been quoted. I'd learned that the UFO's are discussed often. I'd learned that many airline pilots take UFO sightings very seriously. I learned that some believe they are interplanetary, some think they're a U.S. weapon, and many just don't know. But very few are laughing off the good sightings. By May 1950 the flying saucer business had hit a new all-time peak. The Air Force didn't take any side, they just shrugged. There was no attempt to investigate and explain the various sightings. Maybe this was because someone was afraid the answer would be "Unknown." Or maybe it was because a few key officers thought that the eagles or stars on their shoulders made them leaders of all men. If they didn't believe in flying saucers and said so, it would be like calming the stormy Sea of Galilee. "It's all a bunch of damned nonsense," an Air Force colonel who was controlling the UFO investigation said. "There's no such thing as a flying saucer." He went on to say that all people who saw flying saucers were jokers, crackpots, or publicity hounds. Then he gave the airline pilots who'd been reporting UFO's a reprieve. "They were just fatigued," he said. "What they thought were spaceships were windshield reflections." This was the unbiased processing of UFO reports through normal intelligence channels. But the U.S. public evidently had more faith in the "crackpot" scientists who were spending millions of the public's dollars at the White Sands Proving Grounds, in the "publicity-mad" military pilots, and the "tired, old" airline pilots, because in a nationwide poll it was found that only 6 per cent of the country's 150,697,361 people agreed with the colonel and said, "There aren't such things." Ninety-four per cent had different ideas. CHAPTER SEVEN The Pentagon Rumbles On June 25, 1950, the North Korean armies swept down across the 38th parallel and the Korean War was on--the UFO was no longer a news item. But the lady, or gentleman, who first said, "Out of sight is out of mind," had never reckoned with the UFO. On September 8, 1950, the UFO's were back in the news. On that day it was revealed, via a book entitled _Behind_ _the_ _Flying_ _Saucers_, that government scientists had recovered and analyzed three different models of flying saucers. And they were fantastic-- just like the book. They were made of an unknown super-duper metal and they were manned by little blue uniformed men who ate concentrated food and drank heavy water. The author of the book, Frank Scully, had gotten the story directly from a millionaire oilman, Silas Newton. Newton had in turn heard the story from an employee of his, a mysterious "Dr. Gee," one of the government scientists who had helped analyze the crashed saucers. The story made news, Newton and "Dr. Gee" made fame, and Scully made money. A little over two years later Newton and the man who was reportedly the mysterious "Dr. Gee" again made the news. The Denver district attorney's office had looked into the pair's oil business and found that the pockets they were trying to tap didn't contain oil. According to the December 6, 1952, issue of the _Saturday_ _Review_, the D.A. had charged the two men with a $50,000 con game. One of their $800,000 electronic devices for their oil explorations turned out to be a $4.00 piece of war surplus junk. Another book came out in the fall of 1950 when Donald Keyhoe expanded his original UFO story that had first appeared in the January 1950 issue of _True_ magazine. Next to Scully's book Keyhoe's book was tame, but it convinced more people. Keyhoe had based his conjecture on fact, and his facts were correct, even if the conjecture wasn't. Neither the seesaw advances and retreats of the United Nations troops in Korea nor the two flying saucer books seemed to have any effect on the number of UFO reports logged into ATIC, however. By official count, seventy-seven came in the first half of 1950 and seventy-five during the latter half. The actual count could have been more because in 1950, UFO reports were about as popular as sand in spinach, and I would guess that at least a few wound up in the "circular file." In early January 1951 I was recalled to active duty and assigned to Air Technical Intelligence Center as an intelligence officer. I had been at ATIC only eight and a half hours when I first heard the words "flying saucer" officially used. I had never paid a great deal of attention to flying saucer reports but I had read a few--especially those that had been made by pilots. I'd managed to collect some 2,000 hours of flying time and had seen many odd things in the air, but I'd always been able to figure out what they were in a few seconds. I was convinced that if a pilot, or any crew member of an airplane, said that he'd seen something that he couldn't identify he meant it--it wasn't a hallucination. But I wasn't convinced that flying saucers were spaceships. My interest in UFO's picked up in a hurry when I learned that ATIC was the government agency that was responsible for the UFO project. And I was really impressed when I found out that the person who sat three desks down and one over from mine was in charge of the whole UFO show. So when I came to work on my second morning at ATIC and heard the words "flying saucer report" being talked about and saw a group of people standing around the chief of the UFO project's desk I about sprung an eardrum listening to what they had to say. It seemed to be a big deal--except that most of them were laughing. It must be a report of hoax or hallucination, I remember thinking to myself, but I listened as one of the group told the others about the report. The night before a Mid-Continent Airlines DC-3 was taxiing out to take off from the airport at Sioux City, Iowa, when the airport control tower operators noticed a bright bluish-white light in the west. The tower operators, thinking that it was another airplane, called the pilot of the DC-3 and told him to be careful since there was another airplane approaching the field. As the DC-3 lined up to take off, both the pilots of the airliner and the tower operators saw the light moving in, but since it was still some distance away the DC- 3 was given permission to take off. As it rolled down the runway getting up speed, both the pilot and the copilot were busy, so they didn't see the light approaching. But the tower operators did, and as soon as the DC-3 was airborne, they called and told the pilot to be careful. The copilot said that he saw the light and was watching it. Just then the tower got a call from another airplane that was requesting landing instructions and the operators looked away from the light. In the DC-3 the pilot and copilot had also looked away from the light for a few seconds. When they looked back, the bluish-white light had apparently closed in because it was much brighter and it was dead ahead. In a split second it closed in and flashed by their right wing--so close that both pilots thought that they would collide with it. When it passed the DC-3, the pilots saw more than a light-- they saw a huge object that looked like the "fuselage of a B-29." When the copilot had recovered he looked out his side window to see if he could see the UFO and there it was, flying formation with them. He yelled at the pilot, who leaned over and looked just in time to see the UFO disappear. The second look confirmed the Mid-Continent crew's first impression-- the object looked like a B-29 without wings. They saw nothing more, only a big "shadowy shape" and the bluish-white light--no windows, no exhaust. The tower had missed the incident because they were landing the other airplane and the pilot and the copilot didn't have time to call them and tell them about what was going on. All the tower operators could say was that seconds after the UFO had disappeared the light that they had seen was gone. When the airliner landed in Omaha, the crew filed a report that was forwarded to the Air Force. But this wasn't the only report that was filed; a full colonel from military intelligence had been a passenger on the DC-3. He'd seen the UFO too, and he was mighty impressed. I thought that this was an interesting report and I wondered what the official reaction would be. The official reaction was a great big, deep belly laugh. This puzzled me because I'd read that the Air Force was seriously investigating all UFO reports. I continued to eavesdrop on the discussions about the report all day since the UFO expert was about to "investigate" the incident. He sent out a wire to Flight Service and found that there was a B-36 somewhere in the area of Sioux City at the time of the sighting, and from what I could gather he was trying to blame the sighting on the B- 36. When Washington called to get the results of the analysis of the sighting, they must have gotten the B-36 treatment because the case was closed. I'd only been at ATIC two days and I certainly didn't class myself as an intelligence expert, but it didn't take an expert to see that a B-36, even one piloted by an experienced idiot, could not do what the UFO had done--buzz a DC-3 that was in an airport traffic pattern. I didn't know it at the time but a similar event had occurred the year before. On the night of May 29, 1950, the crew of an American Airlines DC-6 had just taken off from Washington National Airport, and they were about seven miles west of Mount Vernon when the copilot suddenly looked out and yelled, "Watch it--watch it." The pilot and the engineer looked out to see a bluish-white light closing in on them from dead ahead. The pilot racked the DC-6 up in a tight right turn while the UFO passed by on the left "from eleven to seven o'clock" and a little higher than the airliner. During this time the UFO passed between the full moon and DC-6 and the crew could see the dark silhouette of a "wingless B-29." Its length was about half the diameter of the full moon, and it had a blue flame shooting out the tail end. Seconds after the UFO had passed by the DC-6, the copilot looked out and there it was again, apparently flying formation off their right wing. Then in a flash of blue flame it was gone--streaking out ahead of the airliner and making a left turn toward the coast. The pilot of the DC-6, who made the report, had better than 15,000 hours' flying time. I didn't hear anything about UFO's, or flying saucers, as they were then known, for several weeks but I kept them in mind and one day I asked one of the old hands at ATIC about them--specifically I wanted to know about the Sioux City Incident. Why had it been sloughed off so lightly? His answer was typical of the official policy at that time. "One of these days all of these crazy pilots will kill themselves, the crazy people on the ground will be locked up, and there won't be any more flying saucer reports." But after I knew the people at ATIC a little better, I found that being anti-saucer wasn't a unanimous feeling. Some of the intelligence officers took the UFO reports seriously. One man, who had been on Project Sign since it was organized back in 1947, was convinced that the UFO's were interplanetary spaceships. He had questioned the people in the control tower at Godman AFB when Captain Mantell was killed chasing the UFO, and he had spent hours talking to the crew of the DC-3 that was buzzed near Montgomery, Alabama, by a "cigar-shaped UFO that spouted blue flame." In essence, he knew UFO history from _A_ _to_ _Z_ because he had "been there." I think that it was this controversial thinking that first aroused my interest in the subject of UFO's and led me to try to sound out a few more people. The one thing that stood out to me, being unindoctrinated in the ways of UFO lore, was the schizophrenic approach so many people at ATIC took. On the surface they sided with the belly-laughers on any saucer issue, but if you were alone with them and started to ridicule the subject, they defended it or at least took an active interest. I learned this one day after I'd been at ATIC about a month. A belated UFO report had come in from Africa. One of my friends was reading it, so I asked him if I could take a look at it when he had finished. In a few minutes he handed it to me. When I finished with the report I tossed it back on my friend's desk, with some comment about the whole world's being nuts. I got a reaction I didn't expect; he wasn't so sure the whole world was nuts-- maybe the nuts were at ATIC. "What's the deal?" I asked him. "Have they really thoroughly checked out every report and found that there's nothing to any of them?" He told me that he didn't think so, he'd been at ATIC a long time. He hadn't ever worked on the UFO project, but he had seen many of their reports and knew what they were doing. He just plain didn't buy a lot of their explanations. "And I'm not the only one who thinks this," he added. "Then why all of the big show of power against the UFO reports?" I remember asking him. "The powers-that-be are anti-flying saucer," he answered about half bitterly, "and to stay in favor it behooves one to follow suit." As of February 1951 this was the UFO project. The words "flying saucer" didn't come up again for a month or two. I'd forgotten all about the two words and was deeply engrossed in making an analysis of the performance of the Mig-15. The Mig had just begun to show up in Korea, and finding out more about it was a hot project. Then the words "flying saucer" drifted across the room once more. But this time instead of belly laughter there was a note of hysteria. It seems that a writer from _Life_ magazine was doing some research on UFO's and rumor had it that _Life_ was thinking about doing a feature article. The writer had gone to the Office of Public Information in the Pentagon and had inquired about the current status of Project Grudge. To accommodate the writer, the OPI had sent a wire out to ATIC: What is the status of Project Grudge? Back went a snappy reply: Everything is under control; each new report is being thoroughly analyzed by our experts; our vast files of reports are in tiptop shape; and in general things are hunky-dunky. All UFO reports are hoaxes, hallucinations, and the misidentification of known objects. Another wire from Washington: Fine, Mr. Bob Ginna of _Life_ is leaving for Dayton. He wants to check some reports. Bedlam in the raw. Other magazines had printed UFO stories, and other reporters had visited ATIC, but they had always stayed in the offices of the top brass. For some reason the name _Life_, the prospects of a feature story, and the feeling that this Bob Ginna was going to ask questions caused sweat to flow at ATIC. Ginna arrived and the ATIC UFO "expert" talked to him. Ginna later told me about the meeting. He had a long list of questions about reports that had been made over the past four years and every time he asked a question, the "expert" would go tearing out of the room to try to find the file that had the answer. I remember that day people spent a lot of time ripping open bundles of files and pawing through them like a bunch of gophers. Many times, "I'm sorry, that's classified," got ATIC out of a tight spot. Ginna, I can assure you, was not at all impressed by the "efficiently operating UFO project." People weren't buying the hoax, hallucination, and misidentification stories quite as readily as the Air Force believed. Where it started or who started it I don't know, but about two months after the visit from _Life's_ representative the official interest in UFO's began to pick up. Lieutenant Jerry Cummings, who had recently been recalled to active duty, took over the project. Lieutenant Cummings is the type of person who when given a job to do does it. In a few weeks the operation of the UFO project had improved considerably. But the project was still operating under political, economic, and manpower difficulties. Cummings' desk was right across from mine, so I began to get a UFO indoctrination via bull sessions. Whenever Jerry found a good report in the pile--and all he had to start with was a pile of papers and files--he'd toss it over for me to read. Some of the reports were unimpressive, I remember. But a few were just the opposite. Two that I remember Jerry's showing me made me wonder how the UFO's could be sloughed off so lightly. The two reports involved movies taken by Air Force technicians at White Sands Proving Ground in New Mexico. The guided missile test range at White Sands is fully instrumented to track high, fast-moving objects--the guided missiles. Located over an area of many square miles there are camera stations equipped with cinetheodolite cameras and linked together by a telephone system. On April 27, 1950, a guided missile had been fired, and as it roared up into the stratosphere and fell back to earth, the camera crews had recorded its flight. All the crews had started to unload their cameras when one of them spotted an object streaking across the sky. By April 1950 every person at White Sands was UFO-conscious, so one member of the camera crew grabbed a telephone headset, alerted the other crews, and told them to get pictures. Unfortunately only one camera had film in it, the rest had already been unloaded, and before they could reload, the UFO was gone. The photos from the one station showed only a smudgy dark object. About all the film proved was that something was in the air and whatever it was, it was moving. Alerted by this first chance to get a UFO to "run a measured course," the camera crews agreed to keep a sharper lookout. They also got the official O.K. to "shoot" a UFO if one appeared. Almost exactly a month later another UFO did appear, or at least at the time the camera crews thought that it was _a_ UFO. This time the crews were ready--when the call went out over the telephone net that a UFO had been spotted, all of the crews scanned the sky. Two of the crews saw it and shot several feet of film as the shiny, bright object streaked across the sky. As soon as the missile tests were completed, the camera crews rushed their film to the processing lab and then took it to the Data Reduction Group. But once again the UFO had eluded man because there were apparently two or more UFO's in the sky and each camera station had photographed a separate one. The data were no good for triangulation. The records at ATIC didn't contain the analysis of these films but they did mention the Data Reduction Group at White Sands. So when I later took over the UFO investigation I made several calls in an effort to run down the actual film and the analysis. The files at White Sands, like all files, evidently weren't very good, because the original reports were gone. I did contact a major who was very co- operative and offered to try to find the people who had worked on the analysis of the film. His report, after talking to two men who had done the analysis, was what I'd expected--nothing concrete except that the UFO's were unknowns. He did say that by putting a correction factor in the data gathered by the two cameras they were able to arrive at a rough estimate of speed, altitude, and size. The UFO was "higher than 40,000 feet, traveling over 2,000 miles per hour, and it was over 300 feet in diameter." He cautioned me, however, that these figures were only estimates, based on the possibly erroneous correction factor; therefore they weren't proof of anything--except that something was in the air. The people at White Sands continued to be on the alert for UFO's while the camera stations were in operation because they realized that if the flight path of a UFO could be accurately plotted and timed it could be positively identified. But no more UFO's showed up. One day Lieutenant Cummings came over to my desk and dropped a stack of reports in front of me. "All radar reports," he said, "and I'm getting more and more of them every day." Radar reports, I knew, had always been a controversial point in UFO history, and if more and more radar reports were coming in, there was no doubt that an already controversial issue was going to be compounded. To understand why there is always some disagreement whenever a flying saucer is picked up on radar, it is necessary to know a little bit about how radar operates. Basically radar is nothing but a piece of electronic equipment that "shouts" out a radio wave and "listens" for the echo. By "knowing" how fast the radio, or radar, wave travels and from which direction the echo is coming, the radar tells the direction and distance of the object that is causing the echo. Any "solid" object like an airplane, bird, ship, or even a moisture-laden cloud can cause a radar echo. When the echo comes back to the radar set, the radar operator doesn't have to listen for it and time it because this is all done for him by the radar set and he sees the "answer" on his radarscope--a kind of a round TV screen. What the radar operator sees is a bright dot, called a "blip" or a "return." The location of the return on the scope tells him the location of the object that was causing the echo. As the object moves through the sky, the radar operator sees a series of bright dots on his scope that make a track. On some radar sets the altitude of the target, the object causing the echo, can also be measured. Under normal conditions the path that the radar waves take as they travel through the air is known. Normal conditions are when the temperature and relative humidity of the air decrease with an increase in altitude. But sometimes a condition will occur where at some level, instead of the temperature and/or relative humidity decreasing with altitude, it will begin to increase. This layer of warm, moist air is known as an inversion layer, and it can do all kinds of crazy things to a radar wave. It can cause part of the radar wave to travel in a big arc and actually pick up the ground many miles away. Or it can cause the wave to bend down just enough to pick up trucks, cars, houses, or anything that has a surface perpendicular to the ground level. One would immediately think that since the ground or a house isn't moving, and a car or truck is moving only 40, 50, or 60 miles an hour, a radar operator should be able to pick these objects out from a fast-moving target. But it isn't as simple as that. The inversion layer shimmers and moves, and one second the radar may be picking up the ground or a truck in one spot and the next second it may be picking up something in a different spot. This causes a series of returns on the scope and can give the illusion of extremely fast or slow speeds. These are but a few of the effects of an inversion layer on radar. Some of the effects are well known, but others aren't. The 3rd Weather Group at Air Defense Command Headquarters in Colorado Springs has done a lot of work on the effects of weather on radar, and they have developed mathematical formulas for telling how favorable weather conditions are for "anomalous propagation," the two-bit words for false radar targets caused by weather. The first problem in analyzing reports of UFO's being picked up on radar is to determine if the weather conditions are right to give anomalous propagation. This can be determined by putting weather data into a formula. If they are, then it is necessary to determine whether the radar targets were real or caused by the weather. This is the difficult job. In most cases the only answer is the appearance of the target on the radar-scope. Many times a weather target will be a fuzzy and indistinct spot on the scope while a real target, an airplane for example, will be bright and sharp. This question of whether a target looked real is the cause of the majority of the arguments about radar-detected UFO's because it is up to the judgment of the radar operator as to what the target looked like. And whenever human judgment is involved in a decision, there is plenty of room for an argument. All during the early summer of 1951 Lieutenant Cummings "fought the syndicate" trying to make the UFO respectable. All the time I was continuing to get my indoctrination. Then one day with the speed of a shotgun wedding, the long-overdue respectability arrived. The date was September 12, 1951, and the exact time was 3:04P.M. On this date and time a teletype machine at Wright-Patterson AFB began to chatter out a message. Thirty-six inches of paper rolled out of the machine before the operator ripped off the copy, stamped it Operational Immediate, and gave it to a special messenger to deliver to ATIC. Lieutenant Cummings got the message. The report was from the Army Signal Corps radar center at Fort Monmouth, New Jersey, and it was red-hot. The incident had started two days before, on September 10, at 11:10A.M., when a student operator was giving a demonstration to a group of visiting brass at the radar school. He demonstrated the set under manual operation for a while, picking up local air traffic, then he announced that he would demonstrate automatic tracking, in which the set is put on a target and follows it without help from the operator. The set could track objects flying at jet speeds. The operator spotted an object about 12,000 yards southeast of the station, flying low toward the north. He tried to switch the set to automatic tracking. He failed, tried again, failed again. He turned to his audience of VIPs, embarrassed. "It's going too fast for the set," he said. "That means it's going faster than a jet!" A lot of very important eyebrows lifted. What flies faster than a jet? The object was in range for three minutes and the operator kept trying, without success, to get into automatic track. The target finally went off the scope, leaving the red-faced operator talking to himself. The radar technicians at Fort Monmouth had checked the weather--there wasn't the slightest indication of an inversion layer. Twenty-five minutes later the pilot of a T-33 jet trainer, carrying an Air Force major as passenger and flying 20,000 feet over Point Pleasant, New Jersey, spotted a dull silver, disklike object far below him. He described it as 30 to 50 feet in diameter and as descending toward Sandy Hook from an altitude of a mile or so. He banked the T-33 over and started down after it. As he shot down, he reported, the object stopped its descent, hovered, then sped south, made a 120-degree turn, and vanished out to sea. The Fort Monmouth Incident then switched back to the radar group. At 3:15P.M. they got an excited, almost frantic call from headquarters to pick up a target high and to the north--which was where the first "faster-than-a-jet" object had vanished--and to pick it up in a hurry. They got a fix on it and reported that it was traveling slowly at 93,000 feet. They also could see it visually as a silver speck. What flies 18 miles above the earth? The next morning two radar sets picked up another target that couldn't be tracked automatically. It would climb, level off, climb again, go into a dive. When it climbed it went almost straight up. The two-day sensation ended that afternoon when the radar tracked another unidentified slow-moving object and tracked it for several minutes. A copy of the message had also gone to Washington. Before Jerry could digest the thirty-six inches of facts, ATIC's new chief, Colonel Frank Dunn, got a phone call. It came from the office of the Director of Intelligence of the Air Force, Major General (now Lieutenant General) C. P. Cabell. General Cabell wanted somebody from ATIC to get to New Jersey--fast--and find out what was going on. As soon as the reports had been thoroughly investigated, the general said that he wanted a complete personal report. Nothing expedites like a telephone call from a general officer, so in a matter of hours Lieutenant Cummings and Lieutenant Colonel N. R. Rosengarten were on an airliner, New Jersey-bound. The two officers worked around the clock interrogating the radar operators, their instructors, and the technicians at Fort Monmouth. The pilot who had chased the UFO in the T-33 trainer and his passenger were flown to New York, and they talked to Cummings and Rosengarten. All other radar stations in the area were checked, but their radars hadn't picked up anything unusual. At about 4:00A.M. the second morning after they had arrived, the investigation was completed, Cummings later told. He and Lieutenant Colonel Rosengarten couldn't get an airliner out of New York in time to get them to the Pentagon by 10:00A.M., the time that had been set up for their report, so they chartered an airplane and flew to the capital to brief the general. General Cabell presided over the meeting, and it was attended by his entire staff plus Lieutenant Cummings, Lieutenant Colonel Rosengarten, and a special representative from Republic Aircraft Corporation. The man from Republic supposedly represented a group of top U.S. industrialists and scientists who thought that there should be a lot more sensible answers coming from the Air Force regarding the UFO's. The man was at the meeting at the personal request of a general officer. Every word of the two-hour meeting was recorded on a wire recorder. The recording was so hot that it was later destroyed, but not before I had heard it several times. I can't tell everything that was said but, to be conservative, it didn't exactly follow the tone of the official Air Force releases--many of the people present at the meeting weren't as convinced that the "hoax, hallucination, and misidentification" answer was The first thing the general wanted to know was, "Who in hell has been giving me these reports that every decent flying saucer sighting is being investigated?" Then others picked up the questioning. "What happened to those two reports that General ------ sent in from Saudi Arabia? He saw those two flying saucers himself." "And who released this big report, anyway?" another person added, picking up a copy of the Grudge Report and slamming it back down on the table. Lieutenant Cummings and Lieutenant Colonel Rosengarten came back to ATIC with orders to set up a new project and report back to General Cabell when it was ready to go. But Cummings didn't get a chance to do much work on the new revitalized Project Grudge--it was to keep the old name--because in a few days he was a civilian. He'd been released from active duty because he was needed back at Cal Tech, where he'd been working on an important government project before his recall to active duty. The day after Cummings got his separation orders, Lieutenant Colonel Rosengarten called me into his office. The colonel was chief of the Aircraft and Missiles branch and one of his many responsibilities was Project Grudge. He said that he knew that I was busy as group leader of my regular group but, if he gave me enough people, could I take Project Grudge? All he wanted me to do was to get it straightened out and operating; then I could go back to trying to outguess the Russians. He threw in a few comments about the good job I'd done straightening out other fouled-up projects. Good old "Rosy." With my ego sufficiently inflated, I said yes. On many later occasions, when I'd land at home in Dayton just long enough for a clean clothes resupply, or when the telephone would ring at 2:00A.M. to report a new "hot" sighting and wake up the baby, Mrs. Ruppelt and I have soundly cussed my ego. I had had the project only a few days when a minor flurry of good UFO reports started. It wasn't supposed to happen because the day after I'd taken over Project Grudge I'd met the ex-UFO "expert" in the hall and he'd nearly doubled up with laughter as he said something about getting stuck with Project Grudge. He predicted that I wouldn't get a report until the newspapers began to play up flying saucers again. "It's all mass hysteria," he said. The first hysterical report of the flurry came from the Air Defense Command. On September 23, 1951, at seven fifty-five in the morning, two F-86's on an early patrol were approaching Long Beach, California, coming in on the west leg of the Long Beach Radio range. All of a sudden the flight leader called his ground controller--high at twelve o'clock he and his wing man saw an object. It was in a gradual turn to its left, and it wasn't another airplane. The ground controller checked his radars but they had nothing, so the ground controller called the leader of the F-86's back and told him to go after the object and try to identify it. The two airplanes started to climb. By this time the UFO had crossed over them but it was still in a turn and was coming back. Several times they tried to intercept, but they could never climb up to it. Once in a while, when they'd appear to be getting close, the UFO would lazily move out of range by climbing slightly. All the time it kept orbiting to the left in a big, wide circle. After about ten minutes the flight leader told the ground controller, who had been getting a running account of the unsuccessful intercept, that their fuel was low and that they'd have to break off soon. They'd gotten a fairly good look at the UFO, the flight leader told the ground controller, and it appeared to be a silver airplane with highly swept-back wings. The controller acknowledged the message and said that he was scrambling all his alert airplanes from George AFB. Could the two F-86's stay in the area a few more minutes? They stayed and in a few minutes four more F- 86's arrived. They saw the UFO immediately and took over. The two F-86's with nearly dry tanks went back to George AFB. For thirty more minutes the newly arrived F-86's worked in pairs trying to get up to the UFO's altitude, which they estimated to be 55,000 feet, but they couldn't make it. All the time the UFO kept slowly circling and speeding up only when the F-86's seemed to get too close. Then they began to run out of fuel and asked for permission to break off the intercept. By this time one remaining F-86 had been alerted and was airborne toward Long Beach. He passed the four homeward-bound F-86's as he was going in, but by the time he arrived over Long Beach the UFO was gone. All the pilots except one reported a "silver airplane with highly swept-back wings." One pilot said the UFO looked round and silver to him. The report ended with a comment by the local intelligence officer. He'd called Edwards AFB, the big Air Force test base north of Los Angeles, but they had nothing in the air. The officer concluded that the UFO was no airplane. In 1951 nothing we had would fly higher than the F-86. This was a good report and I decided to dig in. First I had some more questions I wanted to ask the pilots. I was just in the process of formulating this set of questions when three better reports came in. They automatically got a higher priority than the Long Beach Incident. CHAPTER EIGHT The Lubbock Lights, Unabridged When four college professors, a geologist, a chemist, a physicist, and a petroleum engineer, report seeing the same UFO's on fourteen different occasions, the event can be classified as, at least, unusual. Add the facts that hundreds of other people saw these UFO's and that they were photographed, and the story gets even better. Add a few more facts--that these UFO's were picked up on radar and that a few people got a close look at one of them, and the story begins to convince even the most ardent skeptics. This was the situation the day the reports of the Lubbock Lights arrived at ATIC. Actually the Lubbock Lights, as Project Blue Book calls them, involved many widespread reports. Some of these incidents are known to the public, but the ones that added the emphasis and intrigue to the case and caused hundreds of hours of time to be spent analyzing the reports have not been told before. We collected all of these reports under the one title because there appeared to be a tie- in between them. The first word of the sightings reached ATIC late in September 1951, when the mail girl dropped letters into my "in" basket. One of the letters was from Albuquerque, New Mexico, one was from a small town in Washington State, where I knew an Air Defense Command radar station was located, and the other from Reese AFB at Lubbock, Texas. I opened the Albuquerque letter first. It was a report from 34th Air Defense at Kirtland AFB. The report said that on the evening of August 25, 1951, an employee of the Atomic Energy Commission's supersecret Sandia Corporation and his wife had seen a UFO. About dusk they were sitting in the back yard of their home on the outskirts of Albuquerque. They were gazing at the night sky, commenting on how beautiful it was, when both of them were startled at the sight of a huge airplane flying swiftly and silently over their home. The airplane had been in sight only a few seconds but they had gotten a good look at it because it was so low. They estimated 800 to 1,000 feet. It was the shape of a "flying wing" and one and a half times the size of a B-36. The wing was sharply swept back, almost like a V. Both the husband and wife had seen B-36's over their home many times. They couldn't see the color of the UFO but they did notice that there were dark bands running across the wing from front to back. On the aft edge of the wings there were six to eight pairs of soft, glowing, bluish lights. The aircraft had passed over their house from north to south. The report went on to say that an investigation had been made immediately. Since the object might have been a conventional airplane, air traffic was checked. A commercial airlines Constellation was 50 miles west of Albuquerque and an Air Force B-25 was south of the city, but there had been nothing over Albuquerque that evening. The man's background was checked. He had a "Q" security clearance. This summed up his character, oddballs don't get "Q" clearances. No one else had reported the UFO, but this could be explained by the fact the AEC employee and his wife lived in such a location that anything passing over their home from north to south wouldn't pass over or near very many other houses. A sketch of the UFO was enclosed in the report. I picked up the letter from Lubbock next. It was a thick report, and from the photographs that were attached, it looked interesting. I thumbed through it and stopped at the photos. The first thing that struck me was the similarity between these photos and the report I'd just read. They showed a series of lights in a V shape, very similar to those described as being on the aft edge of the "flying wing" that was reported from Albuquerque. This was something unique, so I read the report in detail. On the night of August 25, 1951, about 9:20P.M., just twenty minutes after the Albuquerque sighting, four college professors from Texas Technological College at Lubbock had observed a formation of soft, glowing, bluish-green lights pass over their home. Several hours later they saw a similar group of lights and in the next two weeks they saw at least ten more. On August 31 an amateur photographer had taken five photos of the lights. Also on the thirty-first two ladies had seen a large "aluminum-colored," "pear-shaped" object hovering near a road north of Lubbock. The report went into the details of these sightings and enclosed a set of the photos that had been taken. This report, in itself, was a good UFO report, but the similarity to the Albuquerque sighting, both in the description of the object and the time that it was seen, was truly amazing. I almost overlooked the report from the radar station because it was fairly short. It said that early on the morning of August 26, only a few hours after the Lubbock sighting, two different radars had shown a target traveling 900 miles per hour at 13,000 feet on a northwesterly heading. The target had been observed for six minutes and an F-86 jet interceptor had been scrambled but by the time the F- 86 had climbed into the air the target was gone. The last paragraph in the report was rather curt and to the point. It was apparently in anticipation of the comments the report would draw. It said that the target was not caused by weather. The officer in charge of the radar station and several members of his crew had been operating radar for seven years and they could recognize a weather target. This target was real. I quickly took out a map of the United States and drew in a course line between Lubbock and the radar station. A UFO flying between these two points would be on a northwesterly heading and the times it was seen at the two places gave it a speed of roughly 900 miles per hour. This was by far the best combination of UFO reports I'd ever read and I'd read every one in the Air Force's files. The first thing I did after reading the reports was to rush a set of the Lubbock photos to the intelligence officer of the 34th Air Division in Albuquerque. I asked him to show the photos to the AEC employee and his wife without telling them what they were. I requested an answer by wire. Later the next day I received my answer: "Observers immediately said that this is what they saw on the night of 25 August. Details by airmail." The details were a sketch the man and his wife had made of a wing around the photo of the Lubbock Lights. The number of lights in the photo and the number of lights the two observers had seen on the wing didn't tally, but they explained this by saying that they could have been wrong in their estimate. The next day I flew to Lubbock to see if I could find an answer to all of these mysterious happenings. I arrived in Lubbock about 5:00P.M. and contacted the intelligence officer at Reese AFB. He knew that I was on my way and had already set up a meeting with the four professors. Right after dinner we met them. If a group had been hand-picked to observe a UFO, we couldn't have picked a more technically qualified group of people. They were: Dr. W. I. Robinson, Professor of Geology. Dr. A. G. Oberg, Professor of Chemical Engineering. Professor W. L. Ducker, Head of the Petroleum Engineering Department. Dr. George, Professor of Physics. This is their story: On the evening of August 25 the four men were sitting in Dr. Robinson's back yard. They were discussing micrometeorites and drinking tea. They jokingly stressed this point. At nine-twenty a formation of lights streaked across the sky directly over their heads. It all happened so fast that none of them had a chance to get a good look. One of the men mentioned that he had always admonished his students for not being more observant; now he was in that spot. He and his colleagues realized they could remember only a few details of what they had seen. The lights were a weird bluish-green color and they were in a semicircular formation. They estimated that there were from fifteen to thirty separate lights and that they were moving from north to south. Their one wish at this time was that the lights would reappear. They did; about an hour later the lights went over again. This time the professors were a little better prepared. With the initial shock worn off, they had time to get a better look. The details they had remembered from the first flight checked. There was one difference; in this flight the lights were not in any orderly formation, they were just in a group. The professors reasoned that if the UFO's appeared twice they might come back. Come back they did. The next night and apparently many times later, as the professors made twelve more observations during the next few weeks. For these later sightings they added two more people to their observing team. Being methodical, as college professors are, they made every attempt to get a good set of data. They measured the angle through which the objects traveled and timed them. The several flights they checked traveled through 90 degrees of sky in three seconds, or 30 degrees per second. The lights usually suddenly appeared 45 degrees above the northern horizon, and abruptly went out 45 degrees above the southern horizon. They always traveled in this north-to-south direction. Outside of the first flight, in which the objects were in a roughly semicircular formation, in none of the rest of the flights did they note any regular pattern. Two or three flights were often seen in one night. They had tried to measure the altitude, with no success. First they tried to compare the lights to the height of clouds but the clouds were never near the lights, or vice versa. Next they tried a more elaborate scheme. They measured off a base line perpendicular to the objects' usual flight path. Friends of the professors made up two teams. Each of the two teams was equipped with elevation-measuring devices, and one team was stationed at each end of the base line. The two teams were linked together by two-way radios. If they sighted the objects they would track and time them, thus getting the speed and altitude. Unfortunately neither team ever saw the lights. But the lights never seemed to want to run the course. The wives of some of the watchers claimed to have seen them from their homes in the city. This later proved to be a clue. The professors were not the sole observers of the mysterious lights. For two weeks hundreds of other people for miles around Lubbock reported that they saw the same lights. The professors checked many of these reports against the times of the flights they had seen and recorded, and many checked out close. They attempted to question these observers as to the length of time they had seen the lights and angles at which they had seen them, but the professors learned what I already knew, people are poor observers. Naturally there has been much discussion among the professors and their friends as to the nature of the lights. A few simple mathematical calculations showed that if the lights were very high they would be traveling very fast. The possibility that they were some natural phenomena was, of course, discussed and seriously considered. The professors did a lot of thinking and research and decided that if they were natural phenomena they were something altogether new. Dr. George, who has since died, studied the phenomena of the night sky during his years as a professor at the University of Alaska, and he had never seen or heard of anything like this before. This was the professors' story. It was early in the morning when we returned to Reese AFB. I sat up a few more hours unsuccessfully trying to figure out what they had seen. The next day I again met the intelligence officer and we went to talk to Carl Hart, Jr., the amateur photographer who had taken the pictures of the lights. Hart was a freshman at Texas Tech. His story was that on the night of August 31 he was lying in his bed in an upstairs room of the Hart home. He, like everyone else in Lubbock, had heard about the lights but he had never seen them. It was a warm night and his bed was pushed over next to an open window. He was looking out at the clear night sky, and had been in bed about a half hour, when he saw a formation of the lights appear in the north, cross an open patch of sky, and disappear over his house. Knowing that the lights might reappear as they had done in the past, he grabbed his loaded Kodak 35, set the lens and shutter at f 3.5 and one tenth of a second, and went out into the middle of the back yard. Before long his vigil was rewarded when the lights made a second pass. He got two pictures. A third formation went over a few minutes later and he got three more pictures. The next morning bright and early Hart said he took the roll of unexposed film to a friend who ran a photo-finishing shop. He explained that he did all of his film processing in this friend's lab. He told the friend about the pictures and they quickly developed them. I stopped Hart at this point and asked why he didn't get more excited about what could be the biggest news photos of the century. He said that the lights had appeared to be so dim that he was sure he didn't have anything on the negatives; had he thought that he did have some good pictures he would have awakened his friend to develop the negatives right away. When he developed the negatives and saw that they showed an image, his friend suggested that he call the newspaper. At first the paper wasn't interested but then they decided to run the photos. I later found out that they had done some checking of their own. We went with Hart into his back yard to re-enact what had taken place. He described the lights as being the same dull, glowing bluish- green color as those seen by the professors. The formation was different, however. The lights Hart saw were always flying in a perfect V. He traced the path from where they appeared over some trees in the north, through an open patch of sky over the back yard, to a point where they disappeared over the house. From the flight path he pointed out, the lights had crossed about 120 degrees of open sky in four seconds. This 30-degree-per-second angular velocity corresponded to the professors' measured angular velocity. We made arrangements to borrow Hart's negatives, thanked him for his information, and left. Armed with a list of names of other observers of the mysterious lights, the intelligence officer and I started out to try to get a cross-section account of the other UFO sightings in the Lubbock area. All the stories about the UFO's were the same; various types of formations of dull bluish-green lights, generally moving north to south. A few people had variations. One lady saw a flying Venetian blind and another a flying double boiler. One point of interest was that very few claimed to have seen the lights before reading the professors' story in the paper, but this could get back to the old question, "Do people look up if they have no reason to do so?" We talked to observers in nearby towns. Their stories were the same. Two of them, tower operators at an airport, reported that they had seen the lights on several occasions. It was in one of these outlying towns, Lamesa, that we talked to an old gentleman, about eighty years old, who gave us a good lead. He had seen the lights and he had identified them. Ever since he had read the story in the papers he had been looking. One evening he and his wife were in their yard looking for the lights. All of a sudden two or three appeared. They were in view for several seconds, then they were gone. In a few minutes the lights did a repeat performance. The man admitted he had been scared. He broke off his story of the lights and launched into his background as a native Texan, with range wars, Indians, and stagecoaches under his belt. What he was trying to point out was that despite the range wars, Indians, and stagecoaches, he had been scared. His wife had been scared too. We had some difficulty getting back to the lights but we finally made it. The third time they came around, he said, one of the lights emitted a sound. It said, "Plover." The old gentleman had immediately identified it as a plover, a water bird about the size of a quail. Later that night, and on several other occasions, they had seen the same thing. After a few more hair-raising but interesting stories of the old west Texas, we left. Our next stop was the federal game warden's office in Lubbock. We got the low-down on plovers. We explained our interest and the warden was very helpful. He had been around west Texas all of his life so he was familiar with wildlife. The oily white breast of a plover could easily reflect light, but plovers usually didn't travel in more than pairs, or three at the most. He had never seen or heard of them traveling in a flock of fifteen to thirty but, of course, this wasn't impossible. Ducks, yes, but probably not plovers. He did say that for some unknown reason there were more than the usual number of plovers in the area that fall. I was anxious to get the negatives that Hart had lent us back to the photo lab at Wright Field, but I had one more call to make. I wanted to talk to the two ladies who had seen a strange object hovering near their car, but I also wanted to write my report before I left Lubbock. Two Air Force special investigators from Reese AFB offered to talk to the ladies, so I stayed at the air base and finished my report. That night when the investigators came back, I got the story. They had spent the whole day talking to the ladies and doing a little discreet checking into their backgrounds. The two ladies, a mother and her daughter, had left their home in Matador, Texas, 70 miles northeast of Lubbock, about twelve-thirty P.M. on August 31. They were driving along in their car when they suddenly noticed "a pear-shaped" object about 150 yards ahead of them. It was just off the side of the road, about 120 feet in the air. It was drifting slowly to the east, "less than the speed required to take off in a Cub airplane." They drove on down the road about 50 more yards, stopped, and got out of the car. The object, which they estimated to be the size of a B-29 fuselage, was still drifting along slowly. There was no sign of any exhaust blast and they heard no noise, but they did see a "porthole" in the side of the object. In a few seconds the object began to pick up speed and rapidly climb out of sight. As it climbed it seemed to have a tight spiraling motion. The investigation showed that the two ladies were "solid citizens," with absolutely no talents, or reasons, for fabricating such a story. The daughter was fairly familiar with aircraft. Her husband was an Air Force officer then in Korea, and she had been living near air bases for several years. The ladies had said that the object was "drifting" to the east, which possibly indicated that it was moving with the wind, but on further investigation it was found that it was moving _into_ the wind. The two investigators had worked all day and hadn't come up with the slightest indication of an answer. This added the final section to my now voluminous report on the Lubbock affair. The next morning as I rode to the airport to catch an airliner back to Dayton I tried to put the whole puzzle together. It was hard to believe that all Fd heard was real. Did a huge flying wing pass over Albuquerque and travel 250 miles to Lubbock in about fifteen minutes? This would be about 900 miles per hour. Did the radar station in Washington pick up the same thing? I'd checked the distances on the big wall map in flight operations just before leaving Reese AFB. It was 1,300 miles from Lubbock to the radar site. From talking to people, we decided that the lights were apparently still around Lubbock at 11:20P.M. and the radar picked them up just after midnight. They would have had to be traveling about 780 miles per hour. This was fairly close to the 900-mile-per-hour speed clocked by the two radars. The photos of the Lubbock Lights checked with the description of what the AEC employee and his wife had seen in Albuquerque. Nobody in Lubbock, however, had reported seeing a "flying wing" with lights. All of this was swimming around in my mind when I stepped out of the staff car at the Lubbock airport. My plane had already landed so I checked in at the ticket counter, picked up a morning paper, and ran out and got into the airplane. I sat down next to a man wearing a Stetson hat and cowboy boots. I soon found out he was a retired rancher from Lubbock. On the front page of the paper was an account of a large meteor that had flashed across New Mexico, west Texas, and Oklahoma the night before. According to the newspaper account, it was very spectacular and had startled a good many people in Lubbock. I was interested in the story because I had seen this meteor. It was a spectacular sight and I could easily understand how such things could be called UFO's. My seat partner must have noticed that I was reading the story of the meteor because he commented that a friend of his, the man who had brought him to the airport, had seen it. We talked about the meteor. This led to a discussion of other odd happenings and left a perfect opening for him to bring up the Lubbock Lights. He asked me if I'd heard about them. I said that I had heard a few vague stories. I hoped that this would stave off any detailed accounts of stories I had been saturated with during the past five days, but it didn't. I heard all the details all over again. As he talked on, I settled back in my seat waiting for a certain thing to happen. Pretty soon it came. The rancher hesitated and the tone of his voice changed to a half-proud, half-apologetic tone. I'd heard this transition many times in the past few months; he was going to tell about the UFO that he had seen. He was going to tell how he had seen the bluish-green lights. I was wrong; what he said knocked me out of my boredom. The same night that the college professors had seen their formation of lights his wife had seen something. Nobody in Lubbock knew about the story, not even their friends. He didn't want anyone to think he and his wife were "crazy." He was telling me only because I was a stranger. Just after dark his wife had gone outdoors to take some sheets off the clothesline. He was inside the house reading the paper. Suddenly his wife had rushed into the house, as he told the story, "as white as the sheets she was carrying." As close as he could remember, he said, this was about ten minutes before the professors made their first sighting. He stopped at this point to tell me about his wife, she wasn't prone to be "flighty" and she "never made up tales." This character qualification was also standard for UFO storytellers. The reason his wife was so upset was that she had seen a large object glide swiftly and silently over the house. She said it looked like "an airplane without a body." On the back edge of the wing were pairs of glowing bluish lights. The Albuquerque sighting! He said he didn't have any idea what his wife had seen but he thought that it was an interesting story. It _was_ an interesting story. It hit me right between the eyes. I knew the rancher and his wife couldn't have possibly heard the Albuquerque couple's story, only they and a few Air Force people knew about it. The chances of two identical stories being made up were infinitesimal, especially since neither of them fitted the standard Lubbock Light description. I wondered how many other people in Lubbock, Albuquerque, or anywhere in the Southwest had seen a similar UFO during this period and hesitated to mention it. I tried to get a few more facts from the rancher but he'd told me all he knew. At Dallas I boarded an airliner to Dayton and he went on to Baton Rouge, never knowing what he'd added to the story of the Lubbock Lights. On the way to Dayton I figured out a plan of attack on the thousands of words of notes I'd taken. The best thing to do, I decided, was to treat each sighting in the Lubbock Light series as a separate incident. All of them seemed to be dependent upon each other for importance. If the objects that were reported in several of the incidents could be identified, the rest would merely become average UFO reports. The photographs taken by Carl Hart, Jr., became number one on the agenda. As soon as I reached Dayton I took Hart's negatives to the Photo Reconnaissance Laboratory at Wright Field. This laboratory, staffed by the Air Force's top photography experts, did all of our analysis of photographs. They went right to work on the negatives and soon had a report. There had originally been five negatives, but when we asked to borrow them Hart could only produce four. The negatives were badly scratched and dirty because so many people had handled them, so it was difficult to tell the actual photographic images from the dust spots and scratches. The first thing that the lab did was to look at each spot on the negatives to see if it was an actual photographic image. They found that the photos showed an inverted V formation of lights. In each photo the individual image of a light was badly blurred due to motion of the camera, but by careful scrutiny of each blurred image they were able to determine that the original lights that Hart had photographed were circular, near pinpoint sources of light. Like a bright star, or a distant light bulb. Next they made enlargements from the negatives and carefully plotted the position of each light in the formation. In each photograph the individual lights in the formation shifted position according to a definite pattern. One additional factor that was brought out in the report was that although the photos were taken on a clear night no images of the stars could be found in the background. This proved one thing, the lights, which were overexposed in the photograph, were a great deal brighter than the stars, or the lights affected the film more than the light from the stars. This was all that the photos showed. It was impossible to determine the size of each image of the group, speed, or altitude. The next thing was to try to duplicate what Hart said he had done. I enlisted the aid of several friends and we tried to photograph a moving light. When we were talking to Hart in Lubbock, he had taken us to his back yard, where he had shot the pictures. He had traced the flight path of fights across the sky. We had him estimate the speed by following an imaginary flight of lights across the sky. It came out to about four seconds. We had a camera identical to the one that Hart had used and set up a light to move at the same speed as the UFO's had flown. We tried to take photographs. In four seconds we could get only two poor shots. These were badly blurred, much worse than Hart's, due to the one-tenth-of-a-second shutter speed. We repeated our experiment several times, each time with the same results. This made a lot of people doubt the authenticity of Hart's photos. With the completed photo lab report in my hands, I was still without an answer. The report was interesting but didn't prove anything. All I could do was to get opinions from as qualified sources as I could find. A physiologist at the Aeromedical Laboratory knocked out the timing theory immediately by saying that if Hart had been excited he could have easily taken three photos in four seconds if we could get two in four seconds in our experiment. Several professional photographers, one of them a top _Life_ photographer, said that if Hart was familiar with his camera and was familiar with panning action shots, his photos would have shown much less blur than ours. I recalled what I heard about Hart's having photographed sporting events for the Lubbock newspaper. This would have called for a good panning technique. The photographs didn't tally with the description of the lights that the professors had seen; in fact, they were firmly convinced that they were of "home manufacture." The professors had reported soft, glowing lights yet the photos showed what should have been extremely bright lights. Hart reported a perfect formation while the professors, except for the first flight, reported an unorderly group. There was no way to explain this disagreement in the arrangement of the lights. Of course, it wasn't impossible that on the night that Hart saw the lights they were flying in a V formation. The first time the professors saw them they were flying in a semicircle. The intensity of the lights was difficult to explain. Again I went to the people in the Photo Reconnaissance Laboratory. I asked them if there was any possible situation that could cause this. They said yes. An intensely bright light source which had a color far over in the red end of the spectrum, bordering on infrared, could do it. The eye is not sensitive to such a light, it could appear dim to the eye yet be "bright" to the film. I asked them what kind of a light source would cause this. There were several things, if you want to speculate, they said, extremely high temperatures for one. But this was as far as they would go. We have nothing in this world that flies that appears dim to the eye yet will show bright on film, they said. This ended the investigation of the photographs, and the investigation ended at a blank wall. My official conclusion, which was later given to the press, was that "The photos were never proven to be a hoax but neither were they proven to be genuine." There is no definite answer. The emphasis of the investigation was now switched to the professors' sighting. The meager amount of data that they had gathered seemed to be accurate but it was inconclusive as far as getting a definite answer was concerned. They had measured two things, how much of the sky the objects had crossed in a certain time and the angle from one side of the formation to the other. These figures didn't mean a great deal, however, since the altitude at which the formation of lights was flying was unknown. If you assumed that the objects were flying at an altitude of 10,000 feet you could easily compute that they were traveling about 3,600 miles per hour, or five to six times the speed of sound. The formation would have been about 1,750 feet wide. If each light was a separate object it could have been in the neighborhood of 100 feet in diameter. These figures were only a guess since nobody knew if the lights were at, above, or below 10,000 feet. If they had been higher they would have been going faster and have been larger. If lower than 10,000 feet, slower and smaller. The only solid lead that had developed while the Reese AFB intelligence officer and I were investigating the professors' sightings was that the UFO's were birds reflecting the city lights; specifically plover. The old cowboy from Lamesa had described something identical to what the professors described and they were plover. Secondly, whenever the professors left the vicinity of their homes to look for the lights they didn't see them, yet their wives, who stayed at home, did see them. If the "lights" were birds they would be flying low and couldn't be seen from more than a few hundred feet. While in Lubbock I'd noticed several main boulevards lighted with the bluish mercury vapor lights. I called the intelligence officer at Reese AFB and he airmailed me a city map of Lubbock with the mercury-vapor-lighted streets marked. The place where the professors had made their observations was close to one of these streets. The big hitch in this theory was that people living miles from a mercury-vapor-lighted boulevard had also reported the lights. How many of these sightings were due to the power of suggestion and how many were authentic I didn't know. If I could have found out, it would have been possible to plot the sightings in Lubbock, and if they were all located close to the lighted boulevards, birds would be an answer. This, however, it was impossible to do. The fact that the lights didn't make any perceivable sound seemed as if it might be a clue. Birds or light phenomena wouldn't make any sound, but how about some object of appreciable size traveling at or above the speed of sound? Jet airplanes don't fly as fast as the speed of sound but they make a horrible roar. Artillery shells, which are going much faster than aircraft, whine as they go through the air. I knew that a great deal of the noise from a jet is due to the heated air rushing out of the tail pipe, but I didn't know exactly how much of the noise this caused. If a jet airplane with a silent engine could be built, how much noise would it make? How far could it be heard? To get the answer I contacted National Advisory Committee for Aeronautics Laboratory at Langley AFB, a government agency which specializes in aeronautical research. They didn't know. Neither they nor anybody else had ever done any research on this question. Their opinion was that such an aircraft could not be heard 5,000 or 10,000 feet away. Aerodynamicists at Wright Field's Aircraft Laboratory agreed. I called the Army's Ballistic Research Laboratories at Aberdeen Proving Grounds, Maryland, to find out why artillery shells whine. These people develop and test all kinds of shells so they would have an answer if anybody did. They said that the majority of the whine of an artillery shell is probably caused by the flat back end of the shell. If a perfectly streamlined shell could be used it would not have any perceivable whine. What I found out, or didn't find out, about the sound of an object moving at several times the speed of sound was typical of nearly every question that came up regarding UFO's. We were working in a field where there were no definite answers to questions. In some instances we were getting into fields far advanced above the then present levels of research. In other instances we were getting into fields where no research had been done at all. It made the problem of UFO analysis one of getting opinions. All we could do was hope the opinions we were getting were the best. My attempts to reach a definite conclusion as to what the professors had seen met another blank wall. I had no more success than I'd had trying to reach a conclusion on the authenticity of the photographs. A thorough analysis of the reports of the flying wings seen by the retired rancher's wife in Lubbock and the AEC employee and his wife in Albuquerque was made. The story from the two ladies who saw the aluminum-colored pear-shaped object hovering near the road near Matador, Texas, was studied, checked, and rechecked. Another blank wall on all three of these sightings. By the time I got around to working on the report from the radar station in Washington State, the data of the weather conditions that existed on the night of the sighting had arrived. I turned the incident folder over to the electronics specialists at ATIC. They made the analysis and determined that the targets were caused by weather, although it was a borderline case. They further surmised that since the targets had been picked up on two radars, if I checked I'd find out that the two targets looked different on the two radarscopes. This is a characteristic of a weather target picked up on radars operating on different frequencies. I did check. I called the radar station and talked to the captain who was in charge of the crew the night the target had been picked up. The target looked the same on both scopes. This was one of the reasons it had been reported, the captain told me. If the target hadn't been the same on both scopes, he wouldn't have made the report since he would have thought he had a weather target. He asked me what ATIC thought about the sighting. I said that Captain James thought it was weather. Just before the long-distance wires between Dayton and Washington melted, I caught some comment about people sitting in swivel chairs miles from the closest radarscope. . . . I took it that he didn't agree the target was caused by weather. But that's the way it officially stands today. Although the case of the Lubbock Lights is officially dead, its memory lingers on. There have never been any more reliable reports of "flying wings" but lights somewhat similar to those seen by the professors have been reported. In about 70 per cent of these cases they were proved to be birds reflecting city lights. The known elements of the case, the professors' sightings and the photos, have been dragged back and forth across every type of paper upon which written material appears, from the cheapest, coarsest pulp to the slick _Life_ pages. Saucer addicts have studied and offered the case as all-conclusive proof, with photos, that UFO's are interplanetary. Dr. Donald Menzel of Harvard studied the case and ripped the sightings to shreds in _Look_, _Time_, and his book, _Flying_ _Saucers_, with the theory that the professors were merely looking at refracted city lights. But none of these people even had access to the full report. This is the first time it has ever been printed. The only other people outside Project Blue Book who have studied the complete case of the Lubbock Lights were a group who, due to their associations with the government, had complete access to our files. And these people were not pulp writers or wide-eyed fanatics, they were scientists--rocket experts, nuclear physicists, and intelligence experts. They had banded together to study our UFO reports because they were convinced that some of the UFO's that were being reported were interplanetary spaceships and the Lubbock series was one of these reports. The fact that the formations of lights were in different shapes didn't bother them; in fact, it convinced them all the more that their ideas of how a spaceship might operate were correct. This group of scientists believed that the spaceships, or at least the part of the spaceship that came relatively close to the earth, would have to have a highly swept-back wing configuration. And they believed that for propulsion and control the craft had a series of small jet orifices all around its edge. Various combinations of these small jets would be turned on to get various flight attitudes. The lights that the various observers saw differed in arrangement because the craft was flying in different flight attitudes. (Three years later the Canadian Government announced that this was exactly the way that they had planned to control the flying saucer that they were trying to build. They had to give up their plans for the development of the saucer-like craft, but now the project has been taken over by the U.S. Air Force.) This is the complete story of the Lubbock Lights as it is carried in the Air Force files, one of the most interesting and most controversial collection of UFO sightings ever to be reported to Project Blue Book. Officially all of the sightings, except the UFO that was picked up on radar, are unknowns. Personally I thought that the professors' lights might have been some kind of birds reflecting the light from mercury-vapor street lights, but I was wrong. They weren't birds, they weren't refracted light, but they weren't spaceships. The lights that the professors saw--the backbone of the Lubbock Light series--have been positively identified as a very commonplace and easily explainable natural phenomenon. It is very unfortunate that I can't divulge exactly the way the answer was found because it is an interesting story of how a scientist set up complete instrumentation to track down the lights and how he spent several months testing theory after theory until he finally hit upon the answer. Telling the story would lead to his identity and, in exchange for his story, I promised the man complete anonymity. But he fully convinced me that he had the answer, and after having heard hundreds of explanations of UFO's, I don't convince easily. With the most important phase of the Lubbock Lights "solved"--the sightings by the professors--the other phases become only good UFO reports. CHAPTER NINE The New Project Grudge While I was in Lubbock, Lieutenant Henry Metscher, who was helping me on Project Grudge, had been sorting out the many bits and pieces of information that Lieutenant Jerry Cummings and Lieutenant Colonel Rosengarten had brought back from Fort Monmouth, New Jersey, and he had the answers. The UFO that the student radar operator had assumed to be traveling at a terrific speed because he couldn't lock on to it turned out to be a 400-mile-an-hour conventional airplane. He'd just gotten fouled up on his procedures for putting the radar set on automatic tracking. The sighting by the two officers in the T-33 jet fell apart when Metscher showed how they'd seen a balloon. The second radar sighting of the series also turned out to be a balloon. The frantic phone call from headquarters requesting a reading on the object's altitude was to settle a bet. Some officers in headquarters had seen the balloon launched and were betting on how high it was. The second day's radar sightings were caused by another balloon and weather--both enhanced by the firm conviction that there were some mighty queer goings on over Jersey. The success with the Fort Monmouth Incident had gone to our heads and we were convinced that with a little diligent digging we'd be knocking off saucers like an ace skeet-shooter. With all the confidence in the world, I attacked the Long Beach Incident, which I'd had to drop to go to Lubbock, Texas. But if saucers could laugh, they were probably zipping through the stratosphere chuckling to themselves, because there was no neat solution to this one. In the original report of how the six F-86's chased the high-flying UFO over Long Beach, the intelligence officer who made the report had said that he'd checked all aircraft flights, therefore this wasn't the answer. The UFO could have been a balloon, so I sent a wire to the Air Force weather detachment at the Long Beach Municipal Airport. I wanted the track of any balloon that was in the air at 7:55A.M. on September 23, 1951. While I was waiting for the answers to my two wires, Lieutenant Metscher and I began to sort out old UFO reports. It was a big job because back in 1949, when the old Project Grudge had been disbanded, the files had just been dumped into storage bins. Hank and I now had four filing case drawers full of a heterogeneous mass of UFO reports, letters, copies of letters, and memos. But I didn't get to do much sorting because the mail girl brought in a copy of a wire that had just arrived. It was a report of a UFO sighting at Terre Haute, Indiana. I read it and told Metscher that I'd quickly whip out an answer and get back to helping him sort. But it didn't prove to be that easy. The report from Terre Haute said that on October 9, a CAA employee at Hulman Municipal Airport had observed a silvery UFO. Three minutes later a pilot, flying east of Terre Haute, had seen a similar object. The report lacked many details but a few phone calls filled me in on the complete story. At 1:43P.M. on the ninth a CAA employee at the airport was walking across the ramp in front of the administration building. He happened to glance up at the sky--why, he didn't know--and out of the corner of his eye he caught a flash of light on the southeastern horizon. He stopped and looked at the sky where the flash of light had been but he couldn't see anything. He was just about to walk on when he noticed what he described as "a pinpoint" of light in the same spot where he'd seen the flash. In a second or two the "pinpoint" grew larger and it was obvious to the CAA man that something was approaching the airport at a terrific speed. As he watched, the object grew larger and larger until it flashed directly overhead and disappeared to the northwest. The CAA man said it all happened so fast and he was so amazed that he hadn't called anybody to come out of the nearby hangar and watch the UFO. But when he'd calmed down he remembered a few facts. The UFO had been in sight for about fifteen seconds and during this time it had passed from horizon to horizon. It was shaped like a "flattened tennis ball," was a bright silver color, and when it was directly overhead it was "the size of a 50- cent piece held at arm's length." But this wasn't all there was to the report. A matter of minutes after the sighting a pilot radioed Terre Haute that he had seen a UFO. He was flying from Greencastle, Indiana, to Paris, Illinois, when just east of Paris he'd looked back and to his left. There, level with his airplane and fairly close, was a large silvery object, "like a flattened orange," hanging motionless in the sky. He looked at it a few seconds, then hauled his plane around in a tight left bank. He headed directly toward the UFO, but it suddenly began to pick up speed and shot off toward the northeast. The time, by the clock on his instrument panel, was 1:45P.M.--just two minutes after the sighting at Terre Haute. When I finished calling I got an aeronautical chart out of the file and plotted the points of the sighting. The CAA employee had seen the UFO disappear over the northwestern horizon. The pilot had been flying from Greencastle, Indiana, to Paris, Illinois, so he'd have been flying on a heading of just a little less than 270 degrees, or almost straight west. He was just east of Paris when he'd first seen the UFO, and since he said that he'd looked back and to his left, the spot where he saw the UFO would be right at a spot where the CAA man had seen his UFO disappear. Both observers had checked their watches with radio time just after the sightings, so there couldn't be more than a few seconds' discrepancy. All I could conclude was that both had seen the same UFO. I checked the path of every balloon in the Midwest. I checked the weather--it was a clear, cloudless day; I had the two observers' backgrounds checked and I even checked for air traffic, although I knew the UFO wasn't an airplane. I researched the University of Dayton library for everything on daylight meteors, but this was no good. From the description the CAA employee gave, what he'd seen had been a clear-cut, distinct, flattened sphere, with no smoke trail, no sparks and no tail. A daylight meteor, so low as to be described as "a 50-cent piece held at arm's length," would have had a smoke trail, sparks, and would have made a roar that would have jolted the Sphinx. This one was quiet. Besides, no daylight meteor stops long enough to let an airplane turn into it. Conclusion: Unknown. In a few days the data from the Long Beach Incident came in and I started to put it together. A weather balloon had been launched from the Long Beach Airport, and it was in the vicinity where the six F- 86's had made their unsuccessful attempt to intercept a UFO. I plotted out the path of the balloon, the reported path of the UFO, and the flight paths of the F-86's. The paths of the balloon and the F-86's were accurate, I knew, because the balloon was being tracked by radio fixes and the F-86's had been tracked by radar. At only one point did the paths of the balloon, UFO, and F-86's coincide. When the first two F-86's made their initial visual contact with the UFO they were looking almost directly at the balloon. But from then on, even by altering the courses of the F-86's, I couldn't prove a thing. In addition, the weather observers from Long Beach said that during the period that the intercept was taking place they had gone outside and looked at their balloon; it was an exceptionally clear day and they could see it at unusually high altitudes. They didn't see any F- 86's around it. And one stronger point, the balloon had burst about ten minutes before the F-86's lost sight of the UFO. Lieutenant Metscher took over and, riding on his Fort Monmouth victory, tried to show how the pilots had seen the balloon. He got the same thing I did--nothing. On October 27, 1951, the new Project Grudge was officially established. I'd written the necessary letters and had received the necessary endorsements. I'd estimated, itemized, and justified direct costs and manpower. I'd conferred, inferred, and referred, and now I had the money to operate. The next step was to pile up all this paper work as an aerial barrier, let the saucers crash into it, and fall just outside the door. I was given a very flexible operating policy for Project Grudge because no one knew the best way to track down UFO's. I had only one restriction and that was that I wouldn't have my people spending time doing a lot of wild speculating. Our job would be to analyze each and every UFO report and try to find what we believed to be an honest, unbiased answer. If we could not identify the reported object as being a balloon, meteor, planet, or one of half a hundred other common things that are sometimes called UFO's, we would mark the folder "Unknown" and file it in a special file. At some later date, when we built up enough of these "Unknown" reports, we'd study them. As long as I was chief of the UFO project, this was our basic rule. If anyone became anti-flying saucer and was no longer capable of making an unbiased evaluation of a report, out he went. Conversely anyone who became a believer was through. We were too busy during the initial phases of the project to speculate as to whether the unknowns were spaceships, space monsters, Soviet weapons, or ethereal visions. I had to let three people go for being too pro or too con. By the latter part of November 1951 I knew most of what had taken place in prior UFO projects and what I expected to do. The people in Project Sign and the old Project Grudge had made many mistakes. I studied these mistakes and profited by them. I could see that my predecessors had had a rough job. Mine would be a little bit easier because of the pioneering they had done. Lieutenant Metscher and I had sorted out all of the pre-1951 files, refiled them, studied them, and outlined the future course of the new Project Grudge. When Lieut. Colonel Rosengarten and Lieutenant Cummings had been at the Pentagon briefing Major General Cabell on the Fort Monmouth incidents, the general had told them to report back when the new project was formed and ready to go. We were ready to go, but before taking my ideas to the Pentagon, I thought it might be wise to try them out on a few other people to get their reaction. Colonel Frank Dunn, then chief of ATIC, liked this idea. We had many well-known scientists and engineers who periodically visited ATIC as consultants, and Colonel Dunn suggested that these people's opinions and comments would be valuable. For the next two weeks every visitor to ATIC who had a reputation as a scientist, engineer, or scholar got a UFO briefing. Unfortunately the names of these people cannot be revealed because I promised them complete anonymity. But the list reads like a page from _Great_ _Men_ _of_ _Science_. Altogether nine people visited the project during this trial period. Of the nine, two thought the Air Force was wasting its time, one could be called indifferent, and six were very enthusiastic over the project. This was a shock to me. I had expected reactions that ranged from an extremely cold absolute zero to a mild twenty below. Instead I found out that UFO's were being freely and seriously discussed in scientific circles. The majority of the visitors thought that the Air Force had goofed on previous projects and were very happy to find out that the project was being re-established. All of the visitors, even the two who thought we were wasting our time, had good suggestions on what to do. All of them offered their services at any future time when they might be needed. Several of these people became very good friends and valuable consultants later on. About two weeks before Christmas, in 1951, Colonel Dunn and I went to the Pentagon to give my report. Major General John A. Samford had replaced Major General Cabell as Director of Intelligence, but General Samford must have been told about the UFO situation because he was familiar with the general aspects of the problem. He had appointed his Assistant for Production, Brigadier General W. M. Garland, to ride herd on the project for him. Colonel Dunn briefly outlined to General Samford what we planned to do. He explained our basic policy, that of setting aside the unknowns and not speculating on them, and he told how the scientists visiting ATIC had liked the plans for the new Project Grudge. There was some discussion about the Air Force's and ATIC's responsibility for the UFO reports. General Garland stated, and it was later confirmed in writing, that the Air Force was solely responsible for investigating and evaluating all UFO reports. Within the Air Force, ATIC was the responsible agency. This in turn meant that Project Grudge was responsible for all UFO reports made by any branch of the military service. I started my briefing by telling General Samford and his staff about the present UFO situation. The UFO reports had never stopped coming in since they had first started in June 1947. There was some correlation between publicity and the number of sightings, but it was not an established fact that reports came in only when the press was playing up UFO's. Just within the past few months the number of good reports had increased sharply and there had been no publicity. UFO's were seen more frequently around areas vital to the defense of the United States. The Los Alamos-Albuquerque area, Oak Ridge, and White Sands Proving Ground rated high. Port areas, Strategic Air Command bases, and industrial areas ranked next. UFO's had been reported from every state in the Union and from every foreign country. The U.S. did not have a monopoly. The frequency of the UFO reports was interesting. Every July there was a sudden increase in the number of reports and July was always the peak month of the year. Just before Christmas there was usually a minor peak. The Grudge Report had not been the solution to the UFO problem. It was true that a large percentage of the reports were due to the "mis- identification of known objects"; people were seeing balloons, airplanes, planets, but this was not the final answer. There were a few hoaxes, hallucinations, publicity-seekers, and fatigued pilots, but reports from these people constituted less than 1 per cent of the total. Left over was a residue of very good and very "unexplainable" UFO sightings that were classified as unknown. The quality of the reports was getting better, I told the officers; they contained more details that could be used for analysis and the details were more precise and accurate. But still they left much to be desired. Every one of the nine scientists and engineers who had reviewed the UFO material at ATIC had made one strong point: we should give top priority to getting reasonably accurate measurements of the speed, altitude, and size of reported UFO's. This would serve two purposes. First, it would make it easy to sort out reports of common things, such as balloons, airplanes, etc. Second, and more important, if we could get even one fairly accurate measurement that showed that some object was traveling through the atmosphere at high speed, and that it wasn't a meteor, the UFO riddle would be much easier to solve. I had worked out a plan to get some measured data, and I presented it to the group for their comments. I felt sure that before long the press would get wind of the Air Force's renewed effort to identify UFO's. When this happened, instead of being mysterious about the whole thing, we would freely admit the existence of the new project, explain the situation thoroughly and exactly as it was, and say that all UFO reports made to the Air Force would be given careful consideration. In this way we would encourage more people to report what they were seeing and we might get some good data. To further explain my point, I drew a sketch on a blackboard. Suppose that a UFO is reported over a fair-sized city. Now we may get one or two reports, and these reports may be rather sketchy. This does us no good--all we can conclude is that somebody saw something that he couldn't identify. But suppose fifty people from all over the city report the UFO. Then it would be profitable for us to go out and talk to these people, find out the time they saw the UFO, and where they saw it (the direction and height above the horizon). Then we might be able to use these data, work out a triangulation problem, and get a fairly accurate measurement of speed, altitude, and size. Radar, of course, will give an accurate measurement of speed and altitude, I pointed out, but radar is not infallible. There is always the problem of weather. To get accurate radar data on a UFO, it is always necessary to prove that it wasn't weather that was causing the target. Radar is valuable, and we wanted radar reports, I said, but they should be considered only as a parallel effort and shouldn't take the place of visual sightings. In winding up my briefing, I again stressed the point that, as of the end of 1951--the date of this briefing--there was no positive proof that any craft foreign to our knowledge existed. All recommendations for the reorganization of Project Grudge were based solely upon the fact that there were many incredible reports of UFO's from many very reliable people. But they were still just flying saucer reports and couldn't be considered scientific proof. Everyone present at the meeting agreed--each had read or had been briefed on these incredible reports. In fact, two of the people present had seen UFO's. Before the meeting adjourned, Colonel Dunn had one last question. He knew the answer, but he wanted it confirmed. "Does the United States have a secret weapon that is being reported as a UFO?" The answer was a flat "No." In a few days I was notified that my plan had been given the green light. I already had the plan written up in the form of a staff study so I sent it through channels for formal approval. It had been obvious right from the start of the reorganization of Project Grudge that there would be questions that no one on my staff was technically competent to answer. To have a fully staffed project, I'd need an astronomer, a physicist, a chemist, a mathematician, a psychologist, and probably a dozen other specialists. It was, of course, impossible to have all of these people on my staff, so I decided to do the next best thing. I would set up a contract with some research organization who already had such people on their staff; then I would call on them whenever their services were needed. I soon found a place that was interested in such a contract, and the day after Christmas, Colonel S. H. Kirkland, of Colonel Dunn's staff, and I left Dayton for a two-day conference with these people to outline what we wanted. Their organization cannot be identified by name because they are doing other highly secret work for the government. I'll call them Project Bear. Project Bear is a large, well-known research organization in the Midwest. The several hundred engineers and scientists who make up their staff run from experts on soils to nuclear physicists. They would make these people available to me to assist Project Grudge on any problem that might arise from a UFO report. They did not have a staff astronomer or psychologist, but they agreed to get them for us on a subcontract basis. Besides providing experts in every field of science, they would make two studies for us; a study of how much a person can be expected to see and remember from a UFO sighting, and a statistical study of UFO reports. The end product of the study of the powers of observation of a UFO observer would be an interrogation form. Ever since the Air Force had been in the UFO business, attempts had been made to construct a form that a person who had seen a UFO could fill out. Many types had been tried but all of them had major disadvantages. Project Bear, working with the psychology department of a university, would study all of the previous questionnaires, along with actual UFO reports, and try to come up with as near a perfect interrogation form as possible. The idea was to make the form simple and yet extract as much and as accurate data as possible from the observer. The second study that Project Bear would undertake would be a statistical study of all UFO reports. Since 1947 the Air Force had collected about 650 reports, but if our plan to encourage UFO reports worked out the way we expected this number could increase tenfold. To handle this volume of reports, Project Bear said that they would set up a complete UFO file on IBM punch cards. Then if we wanted any bit of information from the files, it would be a matter of punching a few buttons on an IBM card-sorting machine, and the files would be sorted electronically in a few seconds. Approximately a hundred items pertaining to a UFO report would be put on each card. These items included everything from the time the UFO was seen to its position in the sky and the observer's personality. The items punched on the cards would correspond to the items on the questionnaires that Project Bear was going to develop. Besides giving us a rapid method of sorting data, this IBM file would give us a modus operandi file. Our MO file would be similar to the MO files used by police departments to file the methods of operations of a criminal. Thus when we received a report we could put the characteristics of the reported UFO on an IBM punch card, put it into the IBM machine, and compare it with the characteristics of other sightings that had known solutions. The answer might be that out of the one hundred items on the card, ninety-five were identical to previous UFO reports that ducks were flying over a city at night reflecting the city's lights. On the way home from the meeting Colonel Kirkland and I were both well satisfied with the assistance we believed Project Bear could give to Project Grudge. In a few days I again left ATIC, this time for Air Defense Command Headquarters in Colorado Springs, Colorado. I wanted to find out how willing ADC was to help us and what they could do. When I arrived I got a thorough briefing on the operations of ADC and the promise that they would do anything they could to help solve the UFO riddle. All of this co-operation was something that I hadn't expected. I'd been warned by the people who had worked on Project Sign and the old Project Grudge that everybody hated the word UFO--I'd have to fight for everything I asked for. But once again they were wrong. The scientists who visited ATIC, General Samford, Project Bear, and now Air Defense Command couldn't have been more co-operative. I was becoming aware that there was much wider concern about UFO reports than I'd ever realized before. While I traveled around the United States getting the project set up, UFO reports continued to come in and all of them were good. One series of reports was especially good, and they came from a group of people who had had a great deal of experience watching things in the sky--the people who launch the big skyhook balloons for General Mills, Inc. The reports of what the General Mills people had seen while they were tracking their balloons covered a period of over a year. They had just sent them in because they had heard that Project Grudge was being reorganized and was taking a different view on UFO reports. They, like so many other reliable observers, had been disgusted with the previous Air Force attitude toward UFO reports, and they had refused to send in any reports. I decided that these people might be a good source of information, and I wanted to get further details on their reports, so I got orders to go to Minneapolis. A scientist from Project Bear went with me. We arrived on January 14, 1952, in the middle of a cold wave and a blizzard. The Aeronautical Division of General Mills, Inc., of Wheaties and Betty Crocker fame, had launched and tracked every skyhook balloon that had been launched prior to mid-1952. They knew what their balloons looked like under all lighting conditions and they also knew meteorology, aerodynamics, astronomy, and they knew UFO's. I talked to these people for the better part of a full day, and every time I tried to infer that there might be some natural explanation for the UFO's I just about found myself in a fresh snowdrift. What made these people so sure that UFO's existed? In the first place, they had seen many of them. One man told me that one tracking crew had seen so many that the sight of a UFO no longer even especially interested them. And the things that they saw couldn't be explained. For example: On January 16, 1951, two people from General Mills and four people from Artesia, New Mexico, were watching a skyhook balloon from the Artesia airport. They had been watching the balloon off and on for about an hour when one of the group saw two tiny specks on the horizon, off to the northwest. He pointed them out to the others because two airplanes were expected into the airport, and he thought that these might be the airplanes. But as they watched, the two specks began to move in fast, and within a few seconds the observers could see that "the airplanes" were actually two round, dull white objects flying in close formation. The two objects continued to come in and headed straight toward the balloon. When they reached the balloon they circled it once and flew off to the northwest, where they disappeared over the horizon. As the two UFO's circled the balloon, they tipped on edge and the observers saw that they were disk-shaped. When the two UFO's were near the balloon, the observers also had a chance to compare the size of the UFO's with the size of the balloon. If the UFO's were as close to the balloon as they appeared to be they would have been 60 feet in diameter. After my visit to General Mills, Inc., I couldn't help remembering a magazine article I'd read about a year before. It said that there was not a single reliable UFO report that couldn't be attributed to a skyhook balloon. I'd been back at ATIC only a few days when I found myself packing up to leave again. This time it was for New York. A high-priority wire had come into ATIC describing how a Navy pilot had chased a UFO over Mitchel AFB, on Long Island. It was a good report. I remember the trip to New York because my train passed through Elizabeth, New Jersey, early in the morning, and I could see the fires caused by an American Airlines Convair that had crashed. This was the second of the three tragic Elizabeth, New Jersey, crashes. The morning before, on January 21, a Navy pilot had taken off from Mitchel in a TBM. He was a lieutenant commander, had flown in World War II, and was now an engineer at the Navy Special Devices Center on Long Island. At nine-fifty he had cleared the traffic pattern and was at about 2,500 feet, circling around the airfield. He was southeast of the field when he first noticed an object below him and "about three runway lengths off the end of Runway 30." The object looked like the top of a parachute canopy, he told me; it was white and he thought he could see the wedges or panels. He said that he thought that it was moving across the ground a little bit too fast to be drifting with wind, but he was sure that somebody had bailed out and that he was looking at the top of his parachute. He was just ready to call the tower when he suddenly realized that this "parachute" was drifting across the wind. He had just taken off from Runway 30 and knew which direction the wind was blowing. As he watched, the object, whatever it was (by now he no longer thought that it was a parachute), began to gradually climb, so he started to climb, he said, staying above and off to the right of the object. When the UFO started to make a left turn, he followed and tried to cut inside, but he overshot and passed over it. It continued to turn and gain speed, so he dropped the nose of the TBM, put on more power, and pulled in behind the object, which was now level with him. In a matter of seconds the UFO made a 180-degree turn and started to make a big swing around the northern edge of Mitchel AFB. The pilot tried to follow, but the UFO had begun to accelerate rapidly, and since a TBM leaves much to be desired on the speed end, he was getting farther and farther behind. But he did try to follow it as long as he could. As he made a wide turn around the northern edge of the airfield he saw that the UFO was now turning south. He racked the TBM up into a tight left turn to follow, but in a few seconds the UFO had disappeared. When he last saw it, it had crossed the Long Island coast line near Freeport and it was heading out to sea. When he finished his account of the chase, I asked the commander some specific questions about the UFO. He said that just after he'd decided that the UFO was not a parachute it appeared to be at an altitude of about 200 to 300 feet over a residential section. From the time it took it to cover a city block, he'd estimated that it was traveling about 300 miles an hour. Even when he pulled in behind the object and got a good look, it still looked like a parachute canopy-- dome-shaped--white--and it had a dark undersurface. It had been in sight two and a half minutes. He had called the control tower at Mitchel during the chase, he told me, but only to ask if any balloons had been launched. He thought that he might be seeing a balloon. The tower had told him that there was a balloon in the area. Then the commander took out an aeronautical chart and drew in his flight path and the apparent path of the UFO for me. I think that he drew it accurately because he had been continually watching landmarks as he'd chased the UFO and was very careful as he drew the sketches on the map. I checked with the weather detachment at Mitchel and they said that they had released a balloon. They had released it at nine-fifty and from a point southeast of the airfield. I got a plot of its path. Just as in the Long Beach Incident, where the six F-86's tried to intercept the UFO, the balloon was almost exactly in line with the spot where the UFO was first seen, but then any proof you might attempt falls apart. If the pilot knew where he was, and had plotted his flight path even semi-accurately, he was never over the balloon. Yet he was over the UFO. He came within less than 2,000 feet of the UFO when he passed over it; yet he couldn't recognize it as a balloon even though he thought it might be a balloon since the tower had just told him that there was one in the area. He said that he followed the UFO around the north edge of the airfield. Yet the balloon, after it was launched southeast of the field, continued on a southeast course and never passed north of the airfield. But the biggest argument against the object's being a balloon was the fact that the pilot pulled in behind it; it was directly off the nose of his airplane, and although he followed it for more than a minute, it pulled away from him. Once you line up an airplane on a balloon and go straight toward it you will catch it in a matter of seconds, even in the slowest airplane. There have been dogfights with UFO's where the UFO's turned out to be balloons, but the pilots always reported that the UFO "made a pass" at them. In other words, they rapidly caught up with the balloon and passed it. I questioned this pilot over and over on this one point, and he was positive that he had followed directly behind the UFO for over a minute and all the time it was pulling away from him. This is one of the most typical UFO reports we had in our files. It is typical because no matter how you argue there isn't any definite answer. If you want to argue that the pilot didn't know where he was during the chase--that he was 3 or 4 miles from where he thought he was--that he never did fly around the northern edge of the field and get in behind the UFO--then the UFO could have been a balloon. But if you want to believe that the pilot knew where he was all during the chase, and he did have several thousand hours of flying time, then all you can conclude is that the UFO was an unknown. I think the pilot summed up the situation very aptly when he told me, "I don't know what it was, but I've never seen anything like it before or since--maybe it was a spaceship." I went back to Dayton stumped--maybe it was a spaceship. CHAPTER TEN Project Blue Book and the Big Build-Up Just twenty minutes after midnight on January 22, 1952, nineteen and a half hours after the Navy lieutenant commander had chased the UFO near Mitchel AFB, another incident involving an airplane and something unknown was developing in Alaska. In contrast with the unusually balmy weather in New York, the temperature in Alaska that night, according to the detailed account of the incident we received at ATIC, was a miserable 47 degrees below zero. The action was unfolding at one of our northernmost radar outposts in Alaska. This outpost was similar to those you may have seen in pictures, a collection of low, sprawling buildings grouped around the observatory- -like domes that house the antennae of the most modern radar in the world. The entire collection of buildings and domes are one color, solid white, from the plastering of ice and snow. The picture that the outpost makes could be described as fascinating, something out of a Walt Disney fantasy--but talk to somebody who's been there--it's miserable. At 0020, twenty minutes after midnight, an airman watching one of the outpost's radarscopes saw a target appear. It looked like an airplane because it showed up as a bright, distinct spot. But it was unusual because it was northeast of the radar site, and very few airplanes ever flew over this area. Off to the northeast of the station there was nothing but ice, snow, and maybe a few Eskimos until you got to Russia. Occasionally a B-50 weather reconnaissance plane ventured into the area, but a quick check of the records showed that none was there on this night. By the time the radar crew had gotten three good plots of the target, they all knew that it was something unusual--it was at 23,000 feet and traveling 1,500 miles an hour. The duty controller, an Air Force captain, was quickly called; he made a fast check of the targets that had now been put on the plotting board and called to a jet fighter-interceptor base for a scramble. The fighter base, located about 100 miles south of the radar site, acknowledged the captain's call and in a matter of minutes an F-94 jet was climbing out toward the north. While the F-94 was heading north, the radar crew at the outpost watched the unidentified target. The bright dots that marked its path had moved straight across the radarscope, passing within about 50 miles of the site. It was still traveling about 1,500 miles an hour. The radar had also picked up the F-94 and was directing it toward its target when suddenly the unidentified target slowed down, stopped, and reversed its course. Now it was heading directly toward the radar station. When it was within about 30 miles of the station, the radar operator switched his set to a shorter range and lost both the F-94 and the unidentified target. While the radar operator was trying to pick up the target again, the F-94 arrived in the area. The ground controller told the pilot that they had lost the target and asked him to cruise around the area to see if he and his radar operator could pick up anything on the F-94's radar. The pilot said he would but that he was having a little difficulty, was low on fuel, and would have to get back to his base soon. The ground controller acknowledged the pilot's message, and called back to the air base telling them to scramble a second F-94. The first F-94 continued to search the area while the ground radar tried to pick up the target but neither could find it. About this time the second F-94 was coming in, so the ground radar switched back to long range. In a minute they had both of the F-94's and the unidentified target on their scope. The ground controller called the second F-94 and began to vector him into the target. The first F-94 returned to its base. As both the second F-94 and the target approached the radar site, the operator again switched to short range and again he lost the jet and the target. He switched back to long range, but by now they were too close to the radar site and he couldn't pick up either one. The pilot continued on toward where the unidentified target should have been. Suddenly the F-94 radar operator reported a weak target off to the right at 28,000 feet. They climbed into it but it faded before they could make contact. The pilot swung the F-94 around for another pass, and this time the radar operator reported a strong return. As they closed in, the F- 94's radar showed that the target was now almost stationary, just barely moving. The F-94 continued on, but the target seemed to make a sudden dive and they lost it. The pilot of the jet interceptor continued to search the area but couldn't find anything. As the F-94 moved away from the radar station, it was again picked up on the ground radar, but the unidentified target was gone. A third F-94 had been scrambled, and in the meantime its crew took over the search. They flew around for about ten minutes without detecting any targets on their radar. They were making one last pass almost directly over the radar station when the radar operator in the back seat of the F-94 yelled over the interphone that he had a target on his scope. The pilot called ground radar, but by this time both the F-94 and the unidentified target were again too close to the radar station and they couldn't be picked up. The F-94 closed in until it was within 200 yards of the target; then the pilot pulled up, afraid he might collide with whatever was out in the night sky ahead of him. He made another pass, and another, but each time the bright spot on the radar operator's scope just stayed in one spot as if something were defiantly sitting out in front of the F-94 daring the pilot to close in. The pilot didn't take the dare. On each pass he broke off at 200 yards. The F-94 crew made a fourth pass and got a weak return, but it was soon lost as the target seemed to speed away. Ground radar also got a brief return, but in a matter of seconds they too lost the target as it streaked out of range on a westerly heading. As usual, the first thing I did when I read this report was to check the weather. But there was no weather report for this area that was detailed enough to tell whether a weather inversion could have caused the radar targets. But I took the report over to Captain Roy James, anyway, in hopes that he might be able to find a clue that would identify the UFO. Captain James was the chief of the radar section at ATIC. He and his people analyzed all our reports where radar picked up UFO's. Roy had been familiar with radar for many years, having set up one of the first stations in Florida during World War II, and later he took the first aircraft control and warning squadron to Saipan. Besides worrying about keeping his radar operating, he had to worry about the Japs' shooting holes in his antennae. Captain James decided that this Alaskan sighting I'd just shown him was caused by some kind of freak weather. He based his analysis on the fact that the unknown target had disappeared each time the ground radar had been switched to short range. This, he pointed out, is an indication that the radar was picking up some kind of a target that was caused by weather. The same weather that caused the ground radar to act up must have caused false targets on the F-94's radar too, he continued. After all, they had closed to within 200 yards of what they were supposedly picking up; it was a clear moonlight night, yet the crews of the F-94's hadn't seen a thing. Taking a clue from the law profession, he quoted a precedent. About a year before over Oak Ridge, Tennessee, an F-82 interceptor had nearly flown into the ground three times as the pilot attempted to follow a target that his radar operator was picking up. There was a strong inversion that night, and although the target appeared as if it were flying in the air, it was actually a ground target. Since Captain James was the chief of the radar section and he had said "Weather," weather was the official conclusion on the report. But reports of UFO's' being picked up on radar are controversial, and some of the people didn't agree with James's conclusion. A month or two after we'd received the report, I was out in Colorado Springs at Air Defense Command Headquarters. I was eating lunch in the officers' club when I saw an officer from the radar operations section at ADC. He asked me to stop by his office when I had a spare minute, and I said that I would. He said that it was important. It was the middle of the afternoon before I saw him and found out what he wanted. He had been in Alaska on TDY when the UFO had been picked up at the outpost radar site. In fact, he had made a trip to both the radar site and the interceptor base just two days after the sighting, and he had talked about the sighting with the people who had seen the UFO on the radar. He wanted to know what we thought about it. When I told him that the sighting had been written off as weather, I remember that he got a funny look on his face and said, "Weather! What are you guys trying to pull, anyway?" It was obvious that he didn't agree with our conclusion. I was interested in learning what this man thought because I knew that he was one of ADC's ace radar trouble shooters and that he traveled all over the world, on loan from ADC, to work out problems with radars. "From the description of what the targets looked like on the radarscopes, good, strong, bright images, I can't believe that they were caused by weather," he told me. Then he went on to back up his argument by pointing out that when the ground radar was switched to short range both the F-94 and the unknown target disappeared. If just the unknown target had disappeared, then it could have been weather. But since both disappeared, very probably the radar set wasn't working on short ranges for some reason. Next he pointed out that if there was a temperature inversion, which is highly unlikely in northern Alaska, the same inversion that would affect the ground radar wouldn't be present at 25,000 feet or above. I told him about the report from Oak Ridge that Captain James had used as an example, but he didn't buy this comparison. At Oak Ridge, he pointed out, that F-82 was at only 4,000 feet. He didn't know how the F-94's could get to within 200 yards of an object without seeing it, unless the object was painted a dull black. "No," he said, "I can't believe that those radar targets were caused by weather. I'd be much more inclined to believe that they were something real, something that we just don't know about." During the early spring of 1952 reports of radar sightings increased rapidly. Most of them came from the Air Defense Command, but a few came from other agencies. One day, soon after the Alaskan Incident, I got a telephone call from the chief of one of the sections of a civilian experimental radar laboratory in New York State. The people in this lab were working on the development of the latest types of radar. Several times recently, while testing radars, they had detected unidentified targets. To quote my caller, "Some damn odd things are happening that are beginning to worry me." He went on to tell how the people in his lab had checked their radars, the weather, and everything else they could think of, but they could find absolutely nothing to account for the targets; they could only conclude that they were real. I promised him that his information would get to the right people if he'd put it in a letter and send it to ATIC. In about a week the letter arrived--hand-carried by no less than a general. The general, who was from Headquarters, Air Materiel Command, had been in New York at the radar laboratory, and he had heard about the UFO reports. He had personally checked into them because he knew that the people at the lab were some of the sharpest radar engineers in the world. When he found out that these people had already contacted us and had prepared a report for us, he offered to hand-carry it to Wright-Patterson. I can't divulge how high these targets were flying or how fast they were going because it would give an indication of the performance of our latest radar, which is classified Secret. I can say, however, that they were flying mighty high and mighty fast. I turned the letter over to ATIC's electronics branch, and they promised to take immediate action. They did, and really fouled it up. The person who received the report in the electronics branch was one of the old veterans of Projects Sign and Grudge. He knew all about UFO's. He got on the phone, called the radar lab, and told the chief (a man who possibly wrote all of the textbooks this person had used in college) all about how a weather inversion can cause false targets on weather. He was gracious enough to tell the chief of the radar lab to call if he had any more "trouble." We never heard from them again. Maybe they found out what their targets were. Or maybe they joined ranks with the airline pilot who told me that if a flying saucer flew wing tip to wing tip formation with him, he'd never tell the Air Force. In early February I made another trip to Air Defense Command Headquarters in Colorado Springs. This time it was to present a definite plan of how ADC could assist ATIC in getting better data on UFO's. I briefed General Benjamin W. Chidlaw, then the Commanding General of the Air Defense Command, and his staff, telling them about our plan. They agreed with it in principle and suggested that I work out the details with the Director of Intelligence for ADC, Brigadier General W. M. Burgess. General Burgess designated Major Verne Sadowski of his staff to be the ADC liaison officer with Project Grudge. This briefing started a long period of close co-operation between Project Grudge and ADC, and it was a pleasure to work with these people. In all of my travels around the government, visiting and conferring with dozens of agencies, I never had the pleasure of working with or seeing a more smoothly operating and efficient organization than the Air Defense Command. General Chidlaw and General Burgess, along with the rest of the staff at ADC, were truly great officers. None of them were believers in flying saucers, but they recognized the fact that UFO reports were a problem that must be considered. With technological progress what it is today, you can't afford to have _anything_ in the air that you can't identify, be it balloons, meteors, planets or flying saucers. The plan that ADC agreed to was very simple. They agreed to issue a directive to all of their units explaining the UFO situation and telling specifically what to do in case one was detected. All radar units equipped with radarscope cameras would be required to take scope photos of targets that fell into the UFO category--targets that were not airplanes or known weather phenomena. These photos, along with a completed technical questionnaire that would be made up at ATIC by Captain Roy James, would be forwarded to Project Grudge. The Air Defense Command UFO directive would also clarify the scrambling of fighters to intercept a UFO. Since it is the policy of the Air Defense Command to establish the identity of any unidentified target, there were no _special_ orders issued for scrambling fighters to try to identify reported UFO's. A UFO was something unknown and automatically called for a scramble. However, there had been some hesitancy on the part of controllers to send airplanes up whenever radar picked up a target that obviously was not an airplane. The directive merely pointed out to the controllers that it was within the scope of existing regulations to scramble on radar targets that were plotted as traveling too fast or too slow to be conventional airplanes. The decision to scramble fighters was still up to the individual controller, however, and scrambling on UFO's would be a second or third priority. The Air Defense Command UFO directive did not mention shooting at a UFO. This question came up during our planning meeting at Colorado Springs, but, like the authority to scramble, the authority to shoot at anything in the air had been established long ago. Every ADC pilot knows the rules for engagement, the rules that tell him when he can shoot the loaded guns that he always carries. If anything in the air over the United States commits any act that is covered by the rules for engagement, the pilot has the authority to open fire. The third thing that ADC would do would be to integrate the Ground Observer Corps into the UFO reporting net. As a second priority, the GOC would report UFO's--first priority would still be reporting aircraft. Ever since the new Project Grudge had been organized, we hadn't had to deal with any large-scale publicity about UFO's. Occasionally someone would bring in a local item from some newspaper about a UFO sighting, but the sightings never rated more than an inch or two column space. But on February 19, 1952, the calm was broken by the story of how a huge ball of fire paced two B-29's in Korea. The story didn't start a rash of reports as the story of the first UFO sighting did in June 1947, but it was significant in that it started a slow build-up of publicity that was far to surpass anything in the past. This Korean sighting also added to the growing official interest in Washington. Almost every day I was getting one or two telephone calls from some branch of the government, and I was going to Washington at least once every two weeks. I was beginning to spend as much time telling people what was going on as I was doing anything about it. The answer was to get somebody in the Directorate of Intelligence in the Pentagon to act as a liaison officer. I could keep this person informed and he could handle the "branch office" in Washington. Colonel Dunn bought this idea, and Major Dewey J. Fournet got the additional duty of manager of the Pentagon branch. In the future all Pentagon inquiries went to Major Fournet, and if he couldn't answer them he would call me. The arrangement was excellent because Major Fournet took a very serious interest in UFO's and could always be counted on to do a good job. Sometime in February 1952 I had a visit from two Royal Canadian Air Force officers. For some time, I learned, Canada had been getting her share of UFO reports. One of the latest ones, and the one that prompted the visit by the RCAF officers, occurred at North Bay, Ontario, about 250 miles north of Buffalo, New York. On two occasions an orange-red disk had been seen from a new jet fighter base in the area. The Canadians wanted to know how we operated. I gave them the details of how we were currently operating and how we hoped to operate in the future, as soon as the procedures that were now in the planning stages could be put into operation. We agreed to try to set up channels so that we could exchange information and tie in the project they planned to establish with Project Grudge. Our plans for continuing liaison didn't materialize, but through other RCAF intelligence officers I found out that their plans for an RCAF-sponsored project failed. A quasi-official UFO project was set up soon after this, however, and its objective was to use instruments to detect objects coming into the earth's atmosphere. In 1954 the project was closed down because during the two years of operation they hadn't officially detected any UFO's. My sources of information stressed the word "officially." During the time that I was chief of the UFO project, the visitors who passed through my office closely resembled the international brigade. Most of the visits were unofficial in the sense that the officers came to ATIC on other business, but in many instances the other business was just an excuse to come out to Dayton to get filled in on the UFO story. Two RAF intelligence officers who were in the U.S. on a classified mission brought six single-spaced typed pages of questions they and their friends wanted answered. On many occasions Air Force intelligence officers who were stationed in England, France, and Germany, and who returned to the U.S. on business, took back stacks of unclassified flying saucer stories. One civilian intelligence agent who frequently traveled between the U.S. and Europe also acted as the unofficial courier for a German group-- transporting hot newspaper and magazine articles about UFO's that I'd collected. In return I received the latest information on European sightings--sightings that never were released and that we never received at ATIC through official channels. Ever since the fateful day when Lieutenant Jerry Cummings dropped his horn-rimmed glasses down on his nose, tipped his head forward, peered at Major General Cabell over his glasses and, acting not at all like a first lieutenant, said that the UFO investigation was all fouled up, Project Grudge had been gaining prestige. Lieutenant Colonel Rosengarten's promise that I'd be on the project for only a few months went the way of all military promises. By March 1952, Project Grudge was no longer just a project within a group; we had become a separate organization, with the formal title of the Aerial Phenomena Group. Soon after this step-up in the chain of command the project code name was changed to Blue Book. The word "Grudge" was no longer applicable. For those people who like to try to read a hidden meaning into a name, I'll say that the code name Blue Book was derived from the title given to college tests. Both the tests and the project had an abundance of equally confusing questions. Project Blue Book had been made a separate group because of the steadily increasing number of reports we were receiving. The average had jumped from about ten a month to twenty a month since December 1951. In March of 1952 the reports slacked off a little, but April was a big month. In April we received ninety-nine reports. On April 1, Colonel S. H. Kirkland and I went to Los Angeles on business. Before we left ATIC we had made arrangements to attend a meeting of the Civilian Saucer Investigators, a now defunct organization that was very active in 1952. They turned out to be a well-meaning but Don Quixote-type group of individuals. As soon as they outlined their plans for attempting to solve the UFO riddle, it was obvious that they would fail. Project Blue Book had the entire Air Force, money, and enthusiasm behind it and we weren't getting any answers yet. All this group had was the enthusiasm. The highlight of the evening wasn't the Civilian Saucer Investigators, however; it was getting a chance to read Ginna's UFO article in an advance copy of _Life_ magazine that the organization had obtained--the article written from the material Bob Ginna had been researching for over a year. Colonel Kirkwood took one long look at the article, sidled up to me, and said, "We'd better get back to Dayton quick; you're going to be busy." The next morning at dawn I was sound asleep on a United Airlines DC-6, Dayton-bound. The _Life_ article undoubtedly threw a harder punch at the American public than any other UFO article ever written. The title alone, "Have We Visitors from Outer Space?" was enough. Other very reputable magazines, such as True, had said it before, but coming from _Life_, it was different. _Life_ didn't say that the UFO's were from outer space; it just said maybe. But to back up this "maybe," it had quotes from some famous people. Dr. Walther Riedel, who played an important part in the development of the German V-2 missile and is presently the director of rocket engine research for North American Aviation Corporation, said he believed that the UFO's were from outer space. Dr. Maurice Biot, one of the world's leading aerodynamicists, backed him up. But the most important thing about the _Life_ article was the question in the minds of so many readers: "Why was it written?" _Life_ doesn't go blasting off on flights of space fancy without a good reason. Some of the readers saw a clue in the author's comments that the hierarchy of the Air Force was now taking a serious look at UFO reports. "Did the Air Force prompt _Life_ to write the article?" was the question that many people asked themselves. When I arrived at Dayton, newspapermen were beating down the door. The official answer to the _Life_ article was released through the Office of Public Information in the Pentagon: "The article is factual, but _Life's_ conclusions are their own." In answer to any questions about the article's being Air Force-inspired, my weasel- worded answer was that we had furnished _Life_ with some raw data on specific sightings. My answer was purposely weasel-worded because I knew that the Air Force had unofficially inspired the _Life_ article. The "maybe they're interplanetary" with the "maybe" bordering on "they are" was the personal opinion of several very high-ranking officers in the Pentagon--so high that their personal opinion was almost policy. I knew the men and I knew that one of them, a general, had passed his opinions on to Bob Ginna. Oddly enough, the _Life_ article did not cause a flood of reports. The day after the article appeared we got nine sightings, which was unusual, but the next day they dropped off again. The number of reports did take a sharp rise a few days later, however. The cause was the distribution of an order that completed the transformation of the UFO from a bastard son to the family heir. The piece of paper that made Project Blue Book legitimate was Air Force Letter 200-5, Subject: Unidentified Flying Objects. The letter, which was duly signed and sealed by the Secretary of the Air Force, in essence stated that UFO's were not a joke, that the Air Force was making a serious study of the problem, and that Project Blue Book was responsible for the study. The letter stated that the commander of every Air Force installation was responsible for forwarding all UFO reports to ATIC by wire, with a copy to the Pentagon. Then a more detailed report would be sent by airmail. Most important of all, it gave Project Blue Book the authority to directly contact any Air Force unit in the United States without going through any chain of command. This was almost unheard of in the Air Force and gave our project a lot of prestige. The new reporting procedures established by the Air Force letter greatly aided our investigation because it allowed us to start investigating the better reports before they cooled off. But it also had its disadvantages. It authorized the sender to use whatever priority he thought the message warranted. Some things are slow in the military, but a priority message is not one of them. When it comes into the message center, it is delivered to the addressee immediately, and for some reason, all messages reporting UFO's seemed to arrive between midnight and 4:00A.M. I was considered the addressee on all UFO reports. To complicate matters, the messages were usually classified and I would have to go out to the air base and personally sign for them. One such message came in about 4:30A.M. on May 8, 1952. It was from a CAA radio station in Jacksonville, Florida, and had been forwarded over the Flight Service teletype net. I received the usual telephone call from the teletype room at Wright-Patterson, I think I got dressed, and I went out and picked up the message. As I signed for it I remember the night man in the teletype room said, "This is a lulu, Captain." It was a lulu. About one o'clock that morning a Pan-American airlines DC-4 was flying south toward Puerto Rico. A few hours after it had left New York City it was out over the Atlantic Ocean, about 600 miles off Jacksonville, Florida, flying at 8,000 feet. It was a pitch-black night; a high overcast even cut out the glow from the stars. The pilot and copilot were awake but really weren't concentrating on looking for other aircraft because they had just passed into the San Juan Oceanic Control Area and they had been advised by radio that there were no other airplanes in the area. The copilot was turning around to look at number four engine when he noticed a light up ahead. It looked like the taillight of another airplane. He watched it closely for a few seconds since no other airplanes were supposed to be in the area. He glanced out at number four engine for a few seconds, looked back, and he saw that the light was in about the same position as when he'd first seen it. Then he looked down at the prop controls, synchronized the engines, and looked up again. In the few seconds that he had glanced away from the light, it had moved to the right so that it was now directly ahead of the DC-4, and it had increased in size. The copilot reached over and slapped the pilot on the shoulder and pointed. Just at that instant the light began to get bigger and bigger until it was "ten times the size of a landing light of an airplane." It continued to close in and with a flash it streaked by the DC-4's left wing. Before the crew could react and say anything, two more smaller balls of fire flashed by. Both pilots later said that they sat in their seats for several seconds with sweat trickling down their backs. It was one of these two pilots who later said, "Were you ever traveling along the highway about 70 miles an hour at night, have the car that you were meeting suddenly swerve over into your lane and then cut back so that you just miss it by inches? You know the sort of sick, empty feeling you get when it's all over? That's just the way we felt." As soon as the crew recovered from the shock, the pilot picked up his mike, called Jacksonville Radio, and told them about the incident. Minutes later we had the report. The next afternoon Lieutenant Kerry Rothstien, who had replaced Lieutenant Metscher on the project, was on his way to New York to meet the pilots when they returned from Puerto Rico. When Kerry talked to the two pilots, they couldn't add a great deal to their original story. Their final comment was the one we all had heard so many times, "I always thought these people who reported flying saucers were crazy, but now I don't know." When Lieutenant Rothstien returned to Dayton he triple-checked with the CAA for aircraft in the area--but there were none. Could there have been airplanes in the area that CAA didn't know about? The answer was almost a flat "No." No one would fly 600 miles off the coast without filing a flight plan; if he got into trouble or went down, the Coast Guard or Air Rescue Service would have no idea where to look. Kerry was given the same negative answer when he checked on surface shipping. The last possibility was that the UFO's were meteors, but several points in the pilots' story ruled these out. First, there was a solid overcast at about 18,000 feet. No meteor cruises along straight and level below 18,000 feet. Second, on only rare occasions have meteors been seen traveling three in trail. The chances of seeing such a phenomenon are well over one in a billion. Some people have guessed that some kind of an atmospheric phenomenon can form a "wall of air" ahead of an airplane that will act as a mirror and that lights seen at night by pilots are nothing more than the reflection of the airplane's own lights. This could be true in some cases, but to have a reflection you must have a light to reflect. There are no lights on an airplane that even approach being "ten times the size of a landing light." What was it? I know a colonel who says it was the same thing that the two Eastern Airlines' pilots, Clarence Chiles and John Whitted, saw near Montgomery, Alabama, on July 24, 1948, and he thinks that Chiles and Whitted saw a spaceship. Reports for the month of April set an all-time high. These were all reports that came from military installations. In addition, we received possibly two hundred letters reporting UFO's, but we were so busy all we could do was file them for future reference. In May 1952 I'd been out to George AFB in California investigating a series of sightings and was on my way home. I remember the flight to Dayton because the weather was bad all the way. I didn't want to miss my connecting flight in Chicago, or get grounded, because I had faithfully promised my wife that we would go out to dinner the night that I returned to Dayton. I'd called her from Los Angeles to tell her that I was coming in, and she had found a baby sitter and had dinner reservations. I hadn't been home more than about two days a week for the past three months, and she was looking forward to going out for the evening. I reached Dayton about midmorning and went right out to the base. When I arrived at the office, my secretary was gone but there was a big note on my desk: "Call Colonel Dunn as soon as you get in." I called Colonel Dunn; then I called my wife and told her to cancel the baby sitter, cancel the dinner reservations, and pack my other bag. I had to go to Washington. While I'd been in California, Colonel Dunn had received a call from General Samford's office. It seems that a few nights before, one of the top people in the Central Intelligence Agency was having a lawn party at his home just outside Alexandria, Virginia. A number of notable personages were in attendance and they had seen a flying saucer. The report had been passed down to Air Force intelligence, and due to the quality of the brass involved, it was "suggested" that I get to Washington on the double and talk to the host of the party. I was at his office before 5:00P.M. and got his report. About ten o'clock in the evening he and two other people were standing near the edge of his yard talking; he happened to be facing south, looking off across the countryside. He digressed a bit from his story to explain that his home is on a hilltop in the country, and when looking south, he had a view of the entire countryside. While he was talking to the two other people he noticed a light approaching from the west. He had assumed it was an airplane and had casually watched it, but when the light got fairly close, the CIA man said that he suddenly realized there wasn't any sound associated with it. If it were an airplane it would have been close enough for him to hear even above the hum of the guests' conversations. He had actually quit talking and was looking at the light when it stopped for an instant and began to climb almost vertically. He said something to the other guests, and they looked up just in time to see the light finish its climb, stop, and level out. They all watched it travel level for a few seconds, then go into a nearly vertical dive, level out, and streak off to the east. Most everyone at the party had seen the light before it disappeared, and within minutes several friendly arguments as to what it was had developed, I was told. One person thought it was a lighted balloon, and a retired general thought it was an airplane. To settle the arguments, they had made a few telephone calls. I might add that these people were such that the mention of their names on a telephone got quick results. Radar in the Washington area said that there had been no airplanes flying west to east south of Alexandria in the past hour. The weather station at Bolling AFB said that there were no balloons in the area, but as a double check the weather people looked at their records of high-altitude winds. It couldn't have been a balloon because none of the winds up to 65,000 feet were blowing from west to east--and to be able to see a light on a balloon, it has to be well below 65,000 feet; the man from CIA told me that they had even considered the possibility that the UFO was a meteor and that the "jump" had been due to some kind of an atmospheric distortion. But the light had been in sight too long to be a meteor. He added that an army chaplain and two teetotaler guests had also seen the light jump. There wasn't much left for me to do when I finished talking to the man. He and his guests had already made all of the checks that I'd have made. All I could do was go back to Dayton, write up his report, and stamp it "Unknown." Back in March, when it had become apparent that the press was reviving its interest in UFO's, I had suggested that Project Blue Book subscribe to a newspaper clipping service. Such a service could provide several things. First, it would show us exactly how much publicity the UFO's were getting and what was being said, and it would give us the feel of the situation. Then it would also provide a lot of data for our files. In many cases the newspapers got reports that didn't go to the Air Force. Newspaper reporters rival any intelligence officer when it comes to digging up facts, and there was always the possibility that they would uncover and print something we'd missed. This was especially true in the few cases of hoaxes that always accompany UFO publicity. Last, it would provide us with material on which to base a study of the effect of newspaper publicity upon the number and type of UFO reports. Colonel Dunn liked the idea of the clipping service, and it went into effect soon after the first publicity had appeared. Every three or four days we would get an envelope full of clippings. In March the clipping service was sending the clippings to us in letter-sized envelopes. The envelopes were thin--maybe there would be a dozen or so clippings in each one. Then they began to get thicker and thicker, until the people who were doing the clipping switched to using manila envelopes. Then the manila envelopes began to get thicker and thicker. By May we were up to old shoe boxes. The majority of the newspaper stories in the shoe boxes were based on material that had come from ATIC. All of these inquiries from the press were adding to Blue Book's work load and to my problems. Normally a military unit such as ATIC has its own public information officer, but we had none so I was it. I was being quoted quite freely in the press and was repeatedly being snarled at by someone in the Pentagon. It was almost a daily occurrence to have people from the "puzzle palace" call and indignantly ask, "Why did you tell them that?" They usually referred to some bit of information that somebody didn't think should have been released. I finally gave up and complained to Colonel Dunn. I suggested that any contacts with the press be made through the Office of Public Information in the Pentagon. These people were trained and paid to do this job; I wasn't. Colonel Dunn heartily agreed because every time I got chewed out he at least got a dirty look. Colonel Dunn called General Samford's office and they brought in General Sory Smith of the Department of Defense, Office of Public Information. General Smith appointed a civilian on the Air Force Press Desk, Al Chop, to handle all inquiries from the press. The plan was that Al would try to get his answers from Major Dewey Fournet, Blue Book's liaison officer in the Pentagon, and if Dewey didn't have the answer, Al had permission to call me. This arrangement worked out fine because Al Chop had been through previous UFO publicity battles when he was in the Office of Public Information at Wright Field. The interest in the UFO's that was shown by the press in May was surpassed only by the interest of the Pentagon. Starting in May, I gave on the average of one briefing in Washington every two weeks, and there was always a full house. From the tone of the official comments to the public about UFO's, it would indicate that there wasn't a great deal of interest, but nothing could be further from the truth. People say a lot of things behind a door bearing a sign that reads "Secret Briefing in Progress." After one of the briefings a colonel (who is now a brigadier general) presented a plan that called for using several flights of F- 94C jet interceptors for the specific purpose of trying to get some good photographs of UFO's. The flight that he proposed would be an operational unit with six aircraft--two would be on constant alert. The F-94C's, then the hottest operational jet we had, would be stripped of all combat gear to give them peak performance, and they would carry a special camera in the nose. The squadrons would be located at places in the United States where UFO's were most frequently seen. The plan progressed to the point of estimating how soon enough airplanes for two flights could be stripped, how soon special cameras could be built, and whether or not two specific Air Force bases in the U.S. could support the units. Finally the colonel's plan was shelved, but not because he was considered to be crazy. After considerable study and debate at high command level, it was decided that twelve F-94C's couldn't be spared for the job and it would have been ineffective to use fewer airplanes. The consideration that the colonel's plan received was an indication of how some of the military people felt about the importance of finding out exactly what the UFO's really were. And in the discussions the words "interplanetary craft" came up more than once. Requests for briefings came even from the highest figure in the Air Force, Thomas K. Finletter, then the Secretary for Air. On May 8, 1952, Lieutenant Colonel R. J. Taylor of Colonel Dunn's staff and I presented an hour-long briefing to Secretary Finletter and his staff. He listened intently and asked several questions about specific sightings when the briefing was finished. If he was at all worried about the UFO's he certainly didn't show it. His only comment was, "You're doing a fine job, Captain. It must be interesting. Thank you." Then he made the following statement for the press: "No concrete evidence has yet reached us either to prove or disprove the existence of the so-called flying saucers. There remain, however, a number of sightings that the Air Force investigators have been unable to explain. As long as this is true, the Air Force will continue to study flying saucer reports." In May 1952, Project Blue Book received seventy-nine UFO reports compared to ninety-nine in April. It looked as if we'd passed the peak and were now on the downhill side. The 178 reports of the past two months, not counting the thousand or so letters that we'd received directly from the public, had piled up a sizable backlog since we'd had time to investigate and analyze only the better reports. During June we planned to clear out the backlog, and then we could relax. But never underestimate the power of a UFO. In June the big flap hit --they began to deliver clippings in big cardboard cartons. CHAPTER ELEVEN The Big Flap In early June 1952, Project Blue Book was operating according to the operational plan that had been set up in January 1952. It had taken six months to put the plan into effect, and to a person who has never been indoctrinated into the ways of the military, this may seem like a long time. But consult your nearest government worker and you'll find that it was about par for the red tape course. We had learned early in the project that about 60 per cent of the reported UFO's were actually balloons, airplanes, or astronomical bodies viewed under unusual conditions, so our operational plan was set up to quickly weed out this type of report. This would give us more time to concentrate on the unknown cases. To weed out reports in which balloons, airplanes, and astronomical bodies were reported as UFO's, we utilized a flow of data that continually poured into Project Blue Book. We received position reports on all flights of the big skyhook balloons and, by merely picking up the telephone, we could get the details about the flight of any other research balloon or regularly scheduled weather balloon in the United States. The location of aircraft in an area where a UFO had been reported was usually checked by the intelligence officer who made the report, but we double-checked his findings by requesting the location of flights from CAA and military air bases. Astronomical almanacs and journals, star charts, and data that we got from observatories furnished us with clues to UFO's that might be astronomical bodies. All of our investigations in this category of report were double-checked by Project Bear's astronomer. Then we had our newspaper clipping file, which gave us many clues. Hydrographic bulletins and Notams (notices to airmen), published by the government, sometimes gave us other clues. Every six hours we received a complete set of weather data. A dozen or more other sources of data that might shed some light on a reported UFO were continually being studied. To get all this information on balloons, aircraft, astronomical bodies, and what have you, I had to co-ordinate Project Blue Book's operational plan with the Air Force's Air Weather Service, Flight Service, Research and Development Command, and Air Defense Command with the Navy's Office of Naval Research, and the aerology branch of the Bureau of Aeronautics; and with the Civil Aeronautics Administration, Bureau of Standards, several astronomical observatories, and our own Project Bear. Our entire operational plan was similar to a Model A Ford I had while I was in high school--just about the time you would get one part working, another part would break down. When a report came through our screening process and still had the "Unknown" tag on it, it went to the MO file, where we checked its characteristics against other reports. For example, on May 25 we had a report from Randolph AFB, Texas. It went through the screening process and came out "Unknown"; it wasn't a balloon, airplane, or astronomical body. So then it went to the MO file. It was a flock of ducks reflecting the city lights. We knew that the Texas UFO's were ducks because our MO file showed that we had an identical report from Moorhead, Minnesota, and the UFO's at Moorhead were ducks. Radar reports that came into Blue Book went to the radar specialists of ATIC's electronics branch. Sifting through reams of data in search of the answers to the many reports that were pouring in each week required many hours of overtime work, but when a report came out with the final conclusion, "Unknown," we were sure that it was unknown. To operate Project Blue Book, I had four officers, two airmen, and two civilians on my permanent staff. In addition, there were three scientists employed full time on Project Bear, along with several others who worked part time. In the Pentagon, Major Fournet, who had taken on the Blue Book liaison job as an extra duty, was now spending full time on it. If you add to this the number of intelligence officers all over the world who were making preliminary investigations and interviewing UFO observers, Project Blue Book was a sizable effort. Only the best reports we received could be personally investigated in the field by Project Blue Book personnel. The vast majority of the reports had to be evaluated on the basis of what the intelligence officer who had written the report had been able to uncover, or what data we could get by telephone or by mailing out a questionnaire. Our instructions for "what to do before the Blue Book man arrives," which had been printed in many service publications, were beginning to pay off and the reports were continually getting more detailed. The questionnaire we were using in June 1952 was the one that had recently been developed by Project Bear. Project Bear, along with psychologists from a midwestern university, had worked on it for five months. Many test models had been tried before it reached its final form--the standard questionnaire that Blue Book is using today. It ran eight pages and had sixty-eight questions which were booby- trapped in a couple of places to give us a cross check on the reliability of the reporter as an observer. We received quite a few questionnaires answered in such a way that it was obvious that the observer was drawing heavily on his imagination. From this standard questionnaire the project worked up two more specialized types. One dealt with radar sightings of UFO's, the other with sightings made from airplanes. In Air Force terminology a "flap" is a condition, or situation, or state of being of a group of people characterized by an advanced degree of confusion that has not quite yet reached panic proportions. It can be brought on by any number of things, including the unexpected visit of an inspecting general, a major administrative reorganization, the arrival of a hot piece of intelligence information, or the dramatic entrance of a well-stacked female into an officers' club bar. In early June 1952 the Air Force was unknowingly in the initial stages of a flap--a flying saucer flap--_the_ flying saucer flap of 1952. The situation had never been duplicated before, and it hasn't been duplicated since. All records for the number of UFO reports were not just broken, they were disintegrated. In 1948, 167 UFO reports had come into ATIC; this was considered a big year. In June 1952 we received 149. During the four years the Air Force had been in the UFO business, 615 reports had been collected. During the "Big Flap" our incoming-message log showed 717 reports. To anyone who had anything to do with flying saucers, the summer of 1952 was just one big swirl of UFO reports, hurried trips, midnight telephone calls, reports to the Pentagon, press interviews, and very little sleep. If you can pin down a date that the Big Flap started, it would probably be about June 1. It was also on June 1 that we received a good report of a UFO that had been picked up on radar. June 1 was a Sunday, but I'd been at the office all day getting ready to go to Los Alamos the next day. About 5:00P.M. the telephone rang and the operator told me that I had a long-distance call from California. My caller was the chief of a radar test section for Hughes Aircraft Company in Los Angeles, and he was very excited about a UFO he had to report. That morning he and his test crew had been checking out a new late- model radar to get it ready for some tests they planned to run early Monday morning. To see if their set was functioning properly, they had been tracking jets in the Los Angeles area. About midmorning, the Hughes test engineer told me, the jet traffic had begun to drop off, and they were about ready to close down their operation when one of the crew picked up a slow-moving target coming across the San Gabriel Mountains north of Los Angeles. He tracked the target for a few minutes and, from the speed and altitude, decided that it was a DC-3. It was at 11,000 feet and traveling about 180 miles an hour toward Santa Monica. The operator was about ready to yell at the other crew members to shut off the set when he noticed something mighty odd-- there was a big gap between the last and the rest of the regularly spaced bright spots on the radarscope. The man on the scope called the rest of the crew in because DC-3's just don't triple their speed. They watched the target as it made a turn and started to climb over Los Angeles. They plotted one, two, three, and then four points during the target's climb; then one of the crew grabbed a slide rule. Whatever it was, it was climbing 35,000 feet per minute and traveling about 550 miles an hour in the process. Then as they watched the scope, the target leveled out for a few seconds, went into a high- speed dive, and again leveled out at 55,000 feet. When they lost the target, it was heading southeast somewhere near Riverside, California. During the sighting my caller told me that when the UFO was only about ten miles from the radar site two of the crew had gone outside but they couldn't see anything. But, he explained, even the high- flying jets that they had been tracking hadn't been leaving vapor trails. The first thing I asked when the Hughes test engineer finished his story was if the radar set had been working properly. He said that as soon as the UFO had left the scope they had run every possible check on the radar and it was O.K. I was just about to ask my caller if the target might not have been some experimental airplane from Edwards AFB when he second-guessed me. He said that after sitting around looking at each other for about a minute, someone suggested that they call Edwards. They did, and Edwards' flight operations told them that they had nothing in the area. I asked him about the weather. The target didn't look like a weather target was the answer, but just to be sure, the test crew had checked. One of his men was an electronics-weather specialist whom he had hired because of his knowledge of the idiosyncrasies of radar under certain weather conditions. This man had looked into the weather angle. He had gotten the latest weather data and checked it, but there wasn't the slightest indication of an inversion or any other weather that would cause a false target. Just before I hung up I asked the man what he thought he and his crew had picked up, and once again I got the same old answer: "Yesterday at this time any of us would have argued for hours that flying saucers were a bunch of nonsense but now, regardless of what you'll say about what we saw, it was something damned real." I thanked the man for calling and hung up. We couldn't make any more of an analysis of this report than had already been made, it was another unknown. I went over to the MO file and pulled out the stack of cards behind the tab "High-Speed Climb." There must have been at least a hundred cards, each one representing a UFO report in which the reported object made a high-speed climb. But this was the first time radar had tracked a UFO during a climb. During the early part of June, Project Blue Book took another jump up on the organizational chart. A year before the UFO project had consisted of one officer. It had risen from the one-man operation to a project within a group, then to a group, and now it was a section. Neither Project Sign nor the old Project Grudge had been higher than the project-within-a-group level. The chief of a group normally calls for a lieutenant colonel, and since I was just a captain this caused some consternation in the ranks. There was some talk about putting Lieutenant Colonel Ray Taylor of Colonel Dunn's staff in charge. Colonel Taylor was very much interested in UFO's; he had handled some of the press contacts prior to turning this function over to the Pentagon and had gone along with me on briefings, so he knew something about the project. But in the end Colonel Donald Bower, who was my division chief, decided rank be damned, and I stayed on as chief of Project Blue Book. The location within the organizational chart is always indicative of the importance placed on a project. In June 1952 the Air Force was taking the UFO problem seriously. One of the reasons was that there were a lot of good UFO reports coming in from Korea. Fighter pilots reported seeing silver-colored spheres or disks on several occasions, and radar in Japan, Okinawa, and in Korea had tracked unidentified targets. In June our situation map, on which we kept a plot of all of our sightings, began to show an ever so slight trend toward reports beginning to bunch up on the east coast. We discussed this build-up, but we couldn't seem to find any explainable reason for it so we decided that we'd better pay special attention to reports coming from the eastern states. I had this build-up of reports in mind one Sunday night, June 15 to be exact, when the OD at ATIC called me at home and said that we were getting a lot of reports from Virginia. Each report by itself wasn't too good, the OD told me, but together they seemed to mean something. He suggested that I come out and take a look at them--so I did. Individually they weren't too good, but when I lined them up chronologically and plotted them on a map they took the form of a hot report. At 3:40P.M. a woman at Unionville, Virginia, had reported a "very shiny object" at high altitude. At 4:20P.M. the operators of the CAA radio facility at Gordonsville, Virginia, had reported that they saw a "round, shiny object." It was southeast of their station, or directly south of Unionville. At 4:25P.M. the crew of an airliner northwest of Richmond, Virginia, reported a "silver sphere at eleven o'clock high." At 4:43P.M. a Marine pilot in a jet tried to intercept a "round shiny sphere" south of Gordonsville. At 5:43P.M. an Air Force T-33 jet tried to intercept a "shiny sphere" south of Gordonsville. He got above 35,000 feet and the UFO was still far above him. At 7:35P.M. many people in Blackstone, Virginia, about 80 miles south of Gordonsville, reported it. It was a "round, shiny object with a golden glow" moving from north to south. By this time radio commentators in central Virginia were giving a running account of the UFO's progress. At 7:59P.M. the people in the CAA radio facility at Blackstone saw it. At 8:00P.M. jets arrived from Langley AFB to attempt to intercept it, but at 8:05P.M. it disappeared. This was a good report because it was the first time we ever received a series of reports on the same object, and there was no doubt that all these people had reported the same object. Whatever it was, it wasn't moving too fast, because it had traveled only about 90 miles in four hours and twenty-five minutes. I was about ready to give up until morning and go home when my wife called. The local Associated Press man had called our home and she assumed that it was about this sighting. She had just said that I was out so he might not call the base. I decided that I'd better keep working so I'd have the answer in time to keep the story out of the papers. A report like this could cause some excitement. The UFO obviously wasn't a planet because it was moving from north to south, and it was too slow to be an airplane. I called the balloon- plotting center at Lowry AFB, where the tracks of the big skyhook balloons are plotted, but the only big balloons in the air were in the western United States, and they were all accounted for. It might have been a weather balloon. The wind charts showed that the high-altitude winds were blowing in different directions at different altitudes above 35,000 feet, so there was no one flow of air that could have brought a balloon in from a certain area, and I knew that the UFO had to be higher than 35,000 feet because the T-33 jet had been this high and the UFO was still above it. The only thing to do was to check with all of the weather stations in the area. I called Richmond, Roanoke, several places in the vicinity of Washington, D.C., and four or five other weather stations, but all of their balloons were accounted for and none had been anywhere close to the central part of Virginia. A balloon can travel only so far, so there was no sense in checking stations too far away from where the people had seen the UFO, but I took a chance and called Norfolk; Charleston, West Virginia; Altoona, Pennsylvania; and other stations within a 150-mile radius of Gordonsville and Blackstone. Nothing. I still thought it might be a balloon, so I started to call more stations. At Pittsburgh I hit a lead. Their radiosonde balloon had gone up to about 60,000 feet and evidently had sprung a slow leak because it had leveled off at that altitude. Normally balloons go up till they burst at 80,000 or 90,000 feet. The weather forecaster at Pittsburgh said that their records showed they had lost contact with the balloon when it was about 60 miles southeast of their station. He said that the winds at 60,000 feet were constant, so it shouldn't be too difficult to figure out where the balloon went after they had lost it. Things must be dull in Pittsburgh at 2:00 a.m. on Monday mornings, because he offered to plot the course that the balloon probably took and call me back. In about twenty minutes I got my call. It probably was their balloon, the forecaster said. Above 50,000 feet there was a strong flow of air southeast from Pittsburgh, and this fed into a stronger southerly flow that was paralleling the Atlantic coast just east of the Appalachian Mountains. The balloon would have floated along in this flow of air like a log floating down a river. As close as he could estimate, he said, the balloon would arrive in the Gordonsville- Blackstone area in the late afternoon or early evening. This was just about the time the UFO had arrived. "Probably a balloon" was a good enough answer for me. The next morning at 8:00A.M., Al Chop called from the Pentagon to tell me that people were crawling all over his desk wanting to know about a sighting in Virginia. The reports continued to come in. At Walnut Lake, Michigan, a group of people with binoculars watched a "soft white light" go back and forth across the western sky for nearly an hour. A UFO "paced" an Air Force B-25 for thirty minutes in California. Both of these happened on June 18, and although we checked and rechecked them, they came out as unknowns. On June 19 radar at Goose AFB in Newfoundland picked up some odd targets. The targets came across the scope, suddenly enlarged, and then became smaller again. One unofficial comment was that the object was flat or disk-shaped, and that the radar target had gotten bigger because the disk had banked in flight to present a greater reflecting surface. ATIC's official comment was weather. Goose AFB was famous for unusual reports. In early UFO history someone had taken a very unusual colored photo of a "split cloud." The photographer had seen a huge ball of fire streak down through the sky and pass through a high layer of stratus clouds. As the fireball passed through the cloud it cut out a perfect swath. The conclusion was that the fireball was a meteor, but the case is still one of the most interesting in the file because of the photograph. Then in early 1952 there was another good report from this area. It was an unknown. The incident started when the pilot of an Air Force C-54 transport radioed Goose AFB and said that at 10:42P.M. a large fireball had buzzed his airplane. It had come in from behind the C-54, and nobody had seen it until it was just off the left wing. The fireball was so big that the pilot said it looked as if it was only a few hundred feet away. The C-54 was 200 miles southwest, coming into Goose AFB from Westover AFB, Massachusetts, when the incident occurred. The base officer-of-the-day, who was also a pilot, happened to be in the flight operations office at Goose when the message came in and he overheard the report. He stepped outside, walked over to his command car, and told his driver about the radio message, so the driver got out and both of them looked toward the south. They searched the horizon for a few seconds; then suddenly they saw a light closing in from the southwest. Within a second, it was near the airfield. It had increased in size till it was as big as a "golf ball at arm's length," and it looked like a big ball of fire. It was so low that both the OD and his driver dove under the command car because they were sure it was going to hit the airfield. When they turned and looked up they saw the fireball make a 90-degree turn over the airfield and disappear into the northwest. The time was 10:47P.M. The control tower operators saw the fireball too, but didn't agree with the OD and his driver on how low it was. They did think that it had made a 90-degree turn and they didn't think that it was a meteor. In the years they'd been in towers they'd seen hundreds of meteors, but they'd never seen anything like this, they reported. And reports continued to pour into Project Blue Book. It was now not uncommon to get ten or eleven wires in one day. If the letters reporting UFO sightings were counted, the total would rise to twenty or thirty a day. The majority of the reports that came in by wire could be classified as being good. They were reports made by reliable people and they were full of details. Some were reports of balloons, airplanes, etc., but the percentage of unknowns hovered right around 22 per cent. To describe and analyze each report, or even the unknowns, would require a book the size of an unabridged dictionary, so I am covering only the best and most representative cases. One day in mid-June, Colonel Dunn called me. He was leaving for Washington and he wanted me to come in the next day to give a briefing at a meeting. By this time I was taking these briefings as a matter of course. We usually gave the briefings to General Garland and a general from the Research and Development Board, who passed the information on to General Samford, the Director of Intelligence. But this time General Samford, some of the members of his staff, two Navy captains from the Office of Naval Intelligence, and some people I can't name were at the briefing. When I arrived in Washington, Major Fournet told me that the purpose of the meetings, and my briefing, was to try to find out if there was any significance to the almost alarming increase in UFO reports over the past few weeks. By the time that everyone had finished signing into the briefing room in the restricted area of the fourth-floor "B" ring of the Pentagon, it was about 9:15A.M. I started my briefing as soon as everyone was seated. I reviewed the last month's UFO activities; then I briefly went over the more outstanding "Unknown" UFO reports and pointed out how they were increasing in number--breaking all previous records. I also pointed out that even though the UFO subject was getting a lot of publicity, it wasn't the scare-type publicity that had accompanied the earlier flaps--in fact, much of the present publicity was anti- saucer. Then I went on to say that even though the reports we were getting were detailed and contained a great deal of good data, we still had no proof the UFO's were anything real. We could, I said, prove that all UFO reports were merely the misinterpretation of known objects _if_ we made a few assumptions. At this point one of the colonels on General Samford's staff stopped me. "Isn't it true," he asked, "that if you make a few positive assumptions instead of negative assumptions you can just as easily prove that the UFO's are interplanetary spaceships? Why, when you have to make an assumption to get an answer to a report, do you always pick the assumption that proves the UFO's don't exist?" You could almost hear the colonel add, "O.K., so now I've said it." For several months the belief that Project Blue Book was taking a negative attitude and the fact that the UFO's could be interplanetary spaceships had been growing in the Pentagon, but these ideas were usually discussed only in the privacy of offices with doors that would close tight. No one said anything, so the colonel who had broken the ice plunged in. He used the sighting from Goose AFB, where the fireball had buzzed the C-54 and sent the OD and his driver belly-whopping under the command car as an example. The colonel pointed out that even though we had labeled the report "Unknown" it wasn't accepted as proof. He wanted to know why. I said that our philosophy was that the fireball could have been two meteors: one that buzzed the C-54 and another that streaked across the airfield at Goose AFB. Granted a meteor doesn't come within feet of an airplane or make a 90-degree turn, but these could have been optical illusions of some kind. The crew of the C-54, the OD, his driver, and the tower operators didn't recognize the UFO's as meteors because they were used to seeing the normal "shooting stars" that are most commonly seen. But the colonel had some more questions. "What are the chances of having two extremely spectacular meteors in the same area, traveling the same direction, only five minutes apart?" I didn't know the exact mathematical probability, but it was rather small, I had to admit. Then he asked, "What kind of an optical illusion would cause a meteor to appear to make a 90-degree turn?" I had asked our Project Bear astronomer this same question, and he couldn't answer it either. So the only answer I could give the colonel was, "I don't know." I felt as if I were on a witness stand being cross-examined, and that is exactly where I was, because the colonel cut loose. "Why not assume a point that is more easily proved?" he asked. "Why not assume that the C-54 crew, the OD, his driver, and the tower operators did know what they were talking about? Maybe they had seen spectacular meteors during the hundreds of hours that they had flown at night and the many nights that they had been on duty in the tower. Maybe the ball of fire had made a 90-degree turn. Maybe it was some kind of an intelligently controlled craft that had streaked northeast across the Gulf of St. Lawrence and Quebec Province at 2,400 miles an hour. "Why not just simply believe that most people know what they saw?" the colonel said with no small amount of sarcasm in his voice. This last comment started a lively discussion, and I was able to retreat. The colonel had been right in a sense--we were being conservative, but maybe this was the right way to be. In any scientific investigation you always assume that you don't have enough proof until you get a positive answer. I don't think that we had a positive answer--yet. The colonel's comments split the group, and a hot exchange of ideas, pros and cons, and insinuations that some people were imitating ostriches to keep from facing the truth followed. The outcome of the meeting was a directive to take further steps to obtain positive identification of the UFO's. Our original idea of attempting to get several separate reports from one sighting so we could use triangulation to measure speed, altitude, and size wasn't working out. We had given the idea enough publicity, but reports where triangulation could be used were few and far between. Mr. or Mrs. Average Citizen just doesn't look up at the sky unless he or she sees a flash of light or hears a sound. Then even if he or she does look up and sees a UFO, it is very seldom that the report ever gets to Project Blue Book. I think that it would be safe to say that Blue Book only heard about 10 per cent of the UFO's that were seen in the United States. After the meeting I went back to ATIC, and the next day Colonel Don Bower and I left for the west coast to talk to some people about how to get better UFO data. We brought back the idea of using an extremely long focal-length camera equipped with a diffraction grating. The cameras would be placed at various locations throughout the United States where UFO's were most frequently seen. We hoped that photos of the UFO's taken through the diffraction gratings would give us some proof one way or the other. The diffraction gratings we planned to use over the lenses of the cameras were the same thing as prisms; they would split up the light from the UFO into its component parts so that we could study it and determine whether it was a meteor, an airplane, or balloon reflecting sunlight, etc. Or we might be able to prove that the photographed UFO was a craft completely foreign to our knowledge. A red-hot, A-l priority was placed on the camera project, and a section at ATIC that developed special equipment took over the job of obtaining the cameras, or, if necessary, having them designed and built. But the UFO's weren't waiting around till they could be photographed. Every day the tempo and confusion were increasing a little more. By the end of June it was very noticeable that most of the better reports were coming from the eastern United States. In Massachusetts, New Jersey, and Maryland jet fighters had been scrambled almost nightly for a week. On three occasions radar-equipped F-94's had locked on aerial targets only to have the lock-on broken by the apparent violent maneuvers of the target. By the end of June there was also a lull in the newspaper publicity about the UFO's. The forthcoming political conventions had wiped out any mention of flying saucers. But on July 1 there was a sudden outbreak of good reports. The first one came from Boston; then they worked down the coast. About seven twenty-five on the morning of July 1 two F-94's were scrambled to intercept a UFO that a Ground Observer Corps spotter reported was traveling southwest across Boston. Radar couldn't pick it up so the two airplanes were just vectored into the general area. The F-94's searched the area but couldn't see anything. We got the report at ATIC and would have tossed it out if it hadn't been for other reports from the Boston area at that same time. One of these reports came from a man and his wife at Lynn, Massachusetts, nine miles northeast of Boston. At seven-thirty they had noticed the two vapor trails from the climbing jet interceptors. They looked around the sky to find out if they could see what the jets were after and off to the west they saw a bright silver "cigar- shaped object about six times as long as it was wide" traveling southwest across Boston. It appeared to be traveling just a little faster than the two jets. As they watched they saw that an identical UFO was following the first one some distance back. The UFO's weren't leaving vapor trails but, as the man mentioned in his report, this didn't mean anything because you can get above the vapor trail level. And the two UFO's appeared to be at a very high altitude. The two observers watched as the two F-94's searched back and forth far below the UFO's. Then there was another report, also made at seven-thirty. An Air Force captain was just leaving his home in Bedford, about 15 miles northwest of Boston and straight west of Lynn, when he saw the two jets. In his report he said that he, too, had looked around the sky to see if he could see what they were trying to intercept when off to the east he saw a "silvery cigar-shaped object" traveling south. His description of what he observed was almost identical to what the couple in Lynn reported except that he saw only one UFO. When we received the report, I wanted to send someone up to Boston immediately in the hope of getting more data from the civilian couple and the Air Force captain; this seemed to be a tailor-made case for triangulation. But by July 1 we were completely snowed under with reports, and there just wasn't anybody to send. Then, to complicate matters, other reports came in later in the day. Just two hours after the sighting in the Boston area Fort Monmouth, New Jersey, popped back into UFO history. At nine-thirty in the morning twelve student radar operators and three instructors were tracking nine jets on an SCR 584 radar set when two UFO targets appeared on the scope. The two targets came in from the northeast at a slow speed, much slower than the jets that were being tracked, hovered near Fort Monmouth at 50,000 feet for about five minutes, and then took off in a "terrific burst of speed" to the southwest. When the targets first appeared, some of the class went outside with an instructor, and after searching the sky for about a minute, they saw two shiny objects in the same location as the radar showed the two unidentified targets to be. They watched the two UFO's for several minutes and saw them go zipping off to the southwest at exactly the same time that the two radar targets moved off the scope in that direction. We had plotted these reports, the ones from Boston and the one from Fort Monmouth, on a map, and without injecting any imagination or wild assumptions, it looked as if two "somethings" had come down across Boston on a southwesterly heading, crossed Long Island, hovered for a few minutes over the Army's secret laboratories at Fort Monmouth, then proceeded toward Washington. In a way we half expected to get a report from Washington. Our expectations were rewarded because in a few hours a report arrived from that city. A physics professor at George Washington University reported a "dull, gray, smoky-colored" object which hovered north northwest of Washington for about eight minutes. Every once in a while, the professor reported, it would move through an arc of about 15 degrees to the right or left, but it always returned to its original position. While he was watching the UFO he took a 25-cent piece out of his pocket and held it at arm's length so that he could compare its size to that of the UFO. The UFO was about half the diameter of the quarter. When he first saw the UFO, it was about 30 to 40 degrees above the horizon, but during the eight minutes it was in sight it steadily dropped lower and lower until buildings in downtown Washington blocked off the view. Besides being an "Unknown," this report was exceptionally interesting to us because the sighting was made from the center of downtown Washington, D.C. The professor reported that he had noticed the UFO when he saw people all along the street looking up in the air and pointing. He estimated that at least 500 people were looking at it, yet his was the only report we received. This seemed to substantiate our theory that people are very hesitant to report UFO's to the Air Force. But they evidently do tell the newspapers because later on we picked up a short account of the sighting in the Washington papers. It merely said that hundreds of calls had been received from people reporting a UFO. When reports were pouring in at the rate of twenty or thirty a day, we were glad that people were hesitant to report UFO's, but when we were trying to find the answer to a really knotty sighting we always wished that more people had reported it. The old adage of having your cake and eating it, too, held even for the UFO. Technically no one in Washington, besides, of course, Major General Samford and his superiors, had anything to do with making policy decisions about the operation of Project Blue Book or the handling of the UFO situation in general. Nevertheless, everyone was trying to get into the act. The split in opinions on what to do about the rising tide of UFO reports, the split that first came out in the open at General Samford's briefing, was widening every day. One group was getting dead-serious about the situation. They thought we now had plenty of evidence to back up an official statement that the UFO's were something real and, to be specific, not something from this earth. This group wanted Project Blue Book to quit spending time investigating reports from the standpoint of trying to determine if the observer of a UFO had actually seen something foreign to our knowledge and start assuming that he or she had. They wanted me to aim my investigation at trying to find out more about the UFO. Along with this switch in operating policy, they wanted to clamp down on the release of information. They thought that the security classification of the project should go up to Top Secret until we had all of the answers, then the information should be released to the public. The investigation of UFO's along these lines should be a maximum effort, they thought, and their plans called for lining up many top scientists to devote their full time to the project. Someone once said that enthusiasm is infectious, and he was right. The enthusiasm of this group took a firm hold in the Pentagon, at Air Defense Command Headquarters, on the Research and Development Board, and many other agencies throughout the government. But General Samford was still giving the orders, and he said to continue to operate just as we had--keeping an open mind to any ideas. After the minor flurry of reports on July 1 we had a short breathing spell and found time to clean up a sizable backlog of reports. People were still seeing UFO's but the frequency of the sighting curve was dropping steadily. During the first few days of July we were getting only two or three good reports a day. On July 5 the crew of a non-scheduled airliner made page two of many newspapers by reporting a UFO over the AEC's supersecret Hanford, Washington, installation. It was a skyhook balloon. On the twelfth a huge meteor sliced across Indiana, southern Illinois, and Missouri that netted us twenty or thirty reports. Even before they had stopped coming in, we had confirmation from our astronomer that the UFO was a meteor. But forty-two minutes later there was a sighting in Chicago that wasn't so easily explained. According to our weather records, on the night of July 12 it was hot in Chicago. At nine forty-two there were at least 400 people at Montrose Beach trying to beat the heat. Many of them were lying down looking at the stars, so that they saw the UFO as it came in from the west northwest, made a 180-degree turn directly over their heads, and disappeared over the horizon. It was a "large red light with small white lights on the side," most of the people reported. Some of them said that it changed to a single yellow light as it made its turn. It was in sight about five minutes, and during this time no one reported hearing any sound. One of the people at the beach was the weather officer from O'Hare International Airport, an Air Force captain. He immediately called O'Hare. They checked on balloon flights and with radar, but both were negative; radar said that there had been no aircraft in the area of Montrose Beach for several hours. I sent an investigator to Chicago, and although he came back with a lot of data on the sighting, it didn't add up to be anything known. The next day Dayton had its first UFO sighting in a long time when a Mr. Roy T. Ellis, president of the Rubber Seal Products Company, and many other people, reported a teardrop-shaped object that hovered over Dayton for several minutes about midnight. This sighting had an interesting twist because two years later I was in Dayton and stopped in at ATIC to see a friend who is one of the technical advisers at the center. Naturally the conversation got around to the subject of UFO's, and he asked me if I remembered this specific sighting. I did, so he went on to say that he and his wife had seen this UFO that night but they had never told anybody. He was very serious when he admitted that he had no idea what it could have been. Now I'd heard this statement a thousand times before from other people, but coming from this person, it was really something because he was as anti-saucer as anyone I knew. Then he added, "From that time on I didn't think your saucer reporters were as crazy as I used to think they were." The Dayton sighting also created quite a stir in the press. In conjunction with the sighting, the Dayton Daily _Journal_ had interviewed Colonel Richard H. Magee, the Dayton-Oakwood civil defense director; they wanted to know what he thought about the UFO's. The colonel's answer made news: "There's something flying around in our skies and we wish we knew what it was." When the story broke in other papers, the colonel's affiliation with civil defense wasn't mentioned, and he became merely "a colonel from Dayton." Dayton was quickly construed by the public to mean Wright- Patterson AFB and specifically ATIC. Some people in the Pentagon screamed while others gleefully clapped their hands. The gleeful handclaps were from those people who wanted the UFO's to be socially recognized, and they believed that if they couldn't talk their ideas into being they might be able to force them in with the help of this type of publicity. The temporary lull in reporting that Project Blue Book had experienced in early July proved to be only the calm before the storm. By mid-July we were getting about twenty reports a day plus frantic calls from intelligence officers all over the United States as every Air Force installation in the U.S. was being swamped with reports. We told the intelligence officers to send in the ones that sounded the best. The build-up in UFO reports wasn't limited to the United States-- every day we would receive reports from our air attaches in other countries. England and France led the field, with the South American countries running a close third. Needless to say, we didn't investigate or evaluate foreign reports because we had our hands full right at home. Most of us were putting in fourteen hours a day, six days a week. It wasn't at all uncommon for Lieutenant Andy Flues, Bob Olsson, or Kerry Rothstien, my investigators, to get their sleep on an airliner going out or coming back from an investigation. TWA airliners out of Dayton were more like home than home. But we hadn't seen anything yet. All the reports that were coming in were good ones, ones with no answers. Unknowns were running about 40 percent. Rumors persist that in mid-July 1952 the Air Force was braced for an expected invasion by flying saucers. Had these rumormongers been at ATIC in mid-July they would have thought that the invasion was already in full swing. And they would have thought that one of the beachheads for the invasion was Patrick AFB, the Air Force's Guided Missile Long-Range Proving Ground on the east coast of Florida. On the night of July 18, at ten forty-five, two officers were standing in front of base operations at Patrick when they noticed a light at about a 45-degree angle from the horizon and off to the west. It was an amber color and "quite a bit brighter than a star." Both officers had heard flying saucer stories, and both thought the light was a balloon. But, to be comedians, they called to several more officers and airmen inside the operations office and told them to come out and "see the flying saucer." The people came out and looked. A few were surprised and took the mysterious light seriously, at the expense of considerable laughter from the rest of the group. The discussion about the light grew livelier and bets that it was a balloon were placed. In the meantime the light had drifted over the base, had stopped for about a minute, turned, and was now heading north. To settle the bet, one of the officers stepped into the base weather office to find out about the balloon. Yes, one was in the air and being tracked by radar, he was told. The weather officer said that he would call to find out exactly where it was. He called and found out that the weather balloon was being tracked due west of the base and that the light had gone out about ten minutes before. The officer went back outside to find that what was first thought to be a balloon was now straight north of the field and still lighted. To add to the confusion, a second amber light had appeared in the west about 20 degrees lower than where the first one was initially seen, and it was also heading north but at a much greater speed. In a few seconds the first light stopped and started moving back south over the base. While the group of officers and airmen were watching the two lights, the people from the weather office came out to tell the UFO observers that the balloon was still traveling straight west. They were just in time to see a third light come tearing across the sky, directly overhead, from west to east. A weatherman went inside and called the balloon-tracking crew again--their balloon was still far to the west of the base. Inside of fifteen minutes two more amber lights came in from the west, crossed the base, made a 180-degree turn over the ocean, and came back over the observers. In the midst of the melee a radar set had been turned on but it couldn't pick up any targets. This did, however, eliminate the possibility of the lights' being aircraft. They weren't stray balloons either, because the winds at all altitudes were blowing in a westerly direction. They obviously weren't meteors. They weren't searchlights on a haze layer because there was no weather conducive to forming a haze layer and there were no searchlights. They could have been some type of natural phenomenon, if one desires to take the negative approach. Or, if you take the positive approach, they could have been spaceships. The next night radar at Washington National Airport picked up UFO's and one of the most highly publicized sightings of UFO history was in the making. It marked the beginning of the end of the Big Flap. CHAPTER TWELVE The Washington Merry-Go-Round No flying saucer report in the history of the UFO ever won more world acclaim than the Washington National Sightings. When radars at the Washington National Airport and at Andrews AFB, both close to the nation's capital, picked up UFO's, the sightings beat the Democratic National Convention out of headline space. They created such a furor that I had inquiries from the office of the President of the United States and from the press in London, Ottawa, and Mexico City. A junior-sized riot was only narrowly averted in the lobby of the Roger Smith Hotel in Washington when I refused to tell U.S. newspaper reporters what I knew about the sightings. Besides being the most highly publicized UFO sightings in the Air Force annals, they were also the most monumentally fouled-up messes that repose in the files. Although the Air Force said that the incident had been fully investigated, the Civil Aeronautics Authority wrote a formal report on the sightings, and numerous magazine writers studied them, the complete story has never fully been told. The pros have been left out of the con accounts, and the cons were neatly overlooked by the pro writers. For a year after the twin sightings we were still putting little pieces in the puzzle. In some aspects the Washington National Sightings could be classed as a surprise--we used this as an excuse when things got fouled up-- but in other ways they weren't. A few days prior to the incident a scientist, from an agency that I can't name, and I were talking about the build-up of reports along the east coast of the United States. We talked for about two hours, and I was ready to leave when he said that he had one last comment to make--a prediction. From his study of the UFO reports that he was getting from Air Force Headquarters, and from discussions with his colleagues, he said that he thought that we were sitting right on top of a big keg full of loaded flying saucers. "Within the next few days," he told me, and I remember that he punctuated his slow, deliberate remarks by hitting the desk with his fist, "they're going to blow up and you're going to have the granddaddy of all UFO sightings. The sighting will occur in Washington or New York," he predicted, "probably Washington." The trend in the UFO reports that this scientist based his prediction on hadn't gone unnoticed. We on Project Blue Book had seen it, and so had the people in the Pentagon; we all had talked about it. On July 10 the crew of a National Airlines plane reported a light "too bright to be a lighted balloon and too slow to be a big meteor" while they were flying south at 2,000 feet near Quantico, Virginia, just south of Washington. On July 13 another airliner crew reported that when they were 60 miles southwest of Washington, at 11,000 feet, they saw a light below them. It came up to their level, hovered off to the left for several minutes, and then it took off in a fast, steep climb when the pilot turned on his landing lights. On July 14 the crew of a Pan American airliner en route from New York to Miami reported eight UFO's near Newport News, Virginia, about 130 miles south of Washington. Two nights later there was another sighting in exactly the same area but from the ground. At 9:00P.M. a high-ranking civilian scientist from the National Advisory Committee for Aeronautics Laboratory at Langley AFB and another man were standing near the ocean looking south over Hampton Roads when they saw two amber-colored lights, "much too large to be aircraft lights," off to their right, silently traveling north. Just before the two lights got abreast of the two men they made a 180-degree turn and started back toward the spot where they had first been seen. As they turned, the two lights seemed to "jockey for position in the formation." About this time a third light came out of the west and joined the first two; then as the three UFO's climbed out of the area toward the south, several more lights joined the formation. The entire episode had lasted only three minutes. The only possible solution to the sighting was that the two men had seen airplanes. We investigated this report and found that there were several B-26's from Langley AFB in the area at the time of the sighting, but none of the B-26 pilots remembered being over Hampton Roads. In fact, all of them had generally stayed well south of Norfolk until about 10:30P.M. because of thunderstorm activity northwest of Langley. Then there were other factors--the observers heard no sound and they were away from all city noises, aircraft don't carry just one or two amber lights, and the distance between the two lights was such that had they been on an airplane the airplane would have been huge or very close to the observers. And last, but not least, the man from the National Advisory Committee for Aeronautics was a very famous aerodynamicist and of such professional stature that if he said the lights weren't airplanes they weren't. This then was the big build-up to the first Washington national sighting and the reason why my friend predicted that the Air Force was sitting on a big powder keg of loaded flying saucers. When the keg blew the best laid schemes of the mice and men at ATIC, they went the way best laid schemes are supposed to. The first one of the highly publicized Washington national sightings started, according to the CAA's logbook at the airport, at 11:40P.M. on the night of July 19 when two radars at National Airport picked up eight unidentified targets east and south of Andrews AFB. The targets weren't airplanes because they would loaf along at 100 to 130 miles an hour then suddenly accelerate to "fantastically high speeds" and leave the area. During the night the crews of several airliners saw mysterious lights in the same locations that the radars showed the targets; tower operators also saw lights, and jet fighters were brought in. But nobody bothered to tell Air Force Intelligence about the sighting. When reporters began to call intelligence and ask about the big sighting behind the headlines, INTERCEPTORS CHASE FLYING SAUCERS OVER WASHINGTON, D.C., they were told that no one had ever heard of such a sighting. In the next edition the headlines were supplemented by, AIR FORCE WONT TALK. Thus intelligence was notified about the first Washington national sighting. I heard about the sighting about ten o'clock Monday morning when Colonel Donald Bower and I got off an airliner from Dayton and I bought a newspaper in the lobby of the Washington National Airport Terminal Building. I called the Pentagon from the airport and talked to Major Dewey Fournet, but all he knew was what he'd read in the papers. He told me that he had called the intelligence officer at Bolling AFB and that he was making an investigation. We would get a preliminary official report by noon. It was about 1:00P.M. when Major Fournet called me and said that the intelligence officer from Bolling was in his office with the preliminary report on the sightings. I found Colonel Bower, we went up to Major Fournet's office and listened to the intelligence officer's briefing. The officer started by telling us about the location of the radars involved in the incident. Washington National Airport, which is located about three miles south of the heart of the city, had two radars. One was a long-range radar in the Air Route Traffic Control section. This radar had 100-mile range and was used to control all air traffic approaching Washington. It was known as the ARTC radar. The control tower at National Airport had a shorter-range radar that it used to control aircraft in the immediate vicinity of the airport. Bolling AFB, he said, was located just east of National Airport, across the Potomac River. Ten miles farther east, in almost a direct line with National and Bolling, was Andrews AFB. It also had a short- range radar. All of these airfields were linked together by an intercom system. Then the intelligence officer went on to tell about the sighting. When a new shift took over at the ARTC radar room at National Airport, the air traffic was light so only one man was watching the radarscope. The senior traffic controller and the six other traffic controllers on the shift were out of the room at eleven-forty, when the man watching the radarscope noticed a group of seven targets appear. From their position on the scope he knew that they were just east and a little south of Andrews AFB. In a way the targets looked like a formation of slow airplanes, but no formations were due in the area. As he watched, the targets loafed along at 100 to 130 miles an hour; then in an apparent sudden burst of speed two of them streaked out of radar range. These were no airplanes, the man thought, so he let out a yell for the senior controller. The senior controller took one look at the scope and called in two more of the men. They all agreed that these were no airplanes. The targets could be caused by a malfunction in the radar, they thought, so a technician was called in --the set was in perfect working order. The senior controller then called the control tower at National Airport; they reported that they also had unidentified targets on their scopes, so did Andrews. And both of the other radars reported the same slow speeds followed by a sudden burst of speed. One target was clocked at 7,000 miles an hour. By now the targets had moved into every sector of the scope and had flown through the prohibited flying areas over the White House and the Capitol. Several times during the night the targets passed close to commercial airliners in the area and on two occasions the pilots of the airliners saw lights that they couldn't identify, and the lights were in the same spots where the radar showed UFO's to be. Other pilots to whom the ARTC radar men talked on the radio didn't see anything odd, at least that's what they said, but the senior controller knew airline pilots and knew that they were very reluctant to report UFO's. The first sighting of a light by an airline pilot took place shortly after midnight, when an ARTC controller called the pilot of a Capital Airlines flight just taking off from National. The controller asked the pilot to keep watch for unusual lights--or anything. Soon after the pilot cleared the traffic pattern, and while ARTC was still in contact with him, he suddenly yelled, "There's one--off to the right-- and there it goes." The controller had been watching the scope, and a target that had been off to the right of the Capitaliner was gone. During the next fourteen minutes this pilot reported six more identical lights. About two hours later another pilot, approaching National Airport from the south, excitedly called the control tower to report that a light was following him at "eight o'clock level." The tower checked their radar-scope and there was a target behind and to the left of the airliner. The ARTC radar also had the airliner and the UFO target. The UFO tagged along behind and to the left of the airliner until it was within four miles of touchdown on the runway. When the pilot reported the light was leaving, the two radarscopes showed that the target was pulling away from the airliner. Once during the night all three radars, the two at Washington and the one at Andrews AFB, picked up a target three miles north of the Riverdale Radio beacon, north of Washington. For thirty seconds the three radar operators compared notes about the target over the intercom, then suddenly the target was gone--and it left all three radarscopes simultaneously. But the clincher came in the wee hours of the morning, when an ARTC traffic controller called the control tower at Andrews AFB and told the tower operators that ARTC had a target just south of their tower, directly over the Andrews Radio range station. The tower operators looked and there was a "huge fiery-orange sphere" hovering in the sky directly over their range station. Not too long after this excitement had started, in fact just after the technician had checked the radar and found that the targets weren't caused by a radar malfunction, ARTC had called for Air Force interceptors to come in and look around. But they didn't show, and finally ARTC called again--then again. Finally, just about daylight, an F-94 arrived, but by that time the targets were gone. The F-94 crew searched the area for a few minutes but they couldn't find anything unusual so they returned to their base. So ended phase one of the Washington National Sightings. The Bolling AFB intelligence officer said he would write up the complete report and forward it to ATIC. That afternoon things bustled in the Pentagon. Down on the first floor Al Chop was doing his best to stave off the press while up on the fourth floor intelligence officers were holding some serious conferences. There was talk of temperature inversions and the false targets they could cause; but the consensus was that a good radar operator could spot inversion-caused targets, and the traffic controllers who operated the radar at Washington National Airport weren't just out of radar school. Every day the lives of thousands of people depended upon their interpretation of the radar targets they saw on their scopes. And you don't get a job like this unless you've spent a good many years watching a luminous line paint targets on a good many radarscopes. Targets caused by inversions aren't rare--in the years that these men had been working with radar they had undoubtedly seen every kind of target, real or false, that radar can detect. They had told the Bolling AFB intelligence officer that the targets they saw were caused by the radar waves' bouncing off a hard, solid object. The Air Force radar operator at Andrews backed them up; so did two veteran airline pilots who saw lights right where the radar showed a UFO to be. Then on top of all this there were the reports from the Washington area during the previous two weeks--all good--all from airline pilots or equally reliable people. To say the least, the sighting at Washington National was a jolt. Besides trying to figure out what the Washington National UFO's were, we had the problem of what to tell the press. They were now beginning to put on a squeeze by threatening to call a congressman-- and nothing chills blood faster in the military. They wanted some kind of an official statement and they wanted it soon. Some people in intelligence wanted to say just, "We don't know," but others held out for a more thorough investigation. I happened to be in this latter category. Many times in the past I had seen what first seemed to be a good UFO report completely fall apart under a thorough investigation. I was for stalling the press and working all night if necessary to go into every aspect of the sighting. But to go along with the theme of the Washington National Sightings--confusion--there was a lot of talk but no action and the afternoon passed with no further investigation. Finally about 4:00P.M. it was decided that the press, who still wanted an official comment, would get an official "No comment" and that I would stay in Washington and make a more detailed investigation. I called Lieutenant Andy Flues, who was in charge of Project Blue Book while I was gone, to tell him that I was staying over and I found out that they were in a de luxe flap back in Dayton. Reports were pouring out of the teletype machines at the rate of thirty a day and many were as good, if not better, than the Washington incident. I talked this over with Colonel Bower and we decided that even though things were popping back at ATIC the Washington sighting, from the standpoint of national interest, was more important. Feeling like a national martyr because I planned to work all night if necessary, I laid the course of my investigation. I would go to Washington National Airport, Andrews AFB, airlines offices, the weather bureau, and a half dozen other places scattered all over the capital city. I called the transportation section at the Pentagon to get a staff car but it took me only seconds to find out that the regulations said no staff cars except for senior colonels or generals. Colonel Bower tried--same thing. General Samford and General Garland were gone, so I couldn't get them to try to pressure a staff car out of the hillbilly who was dispatching vehicles. I went down to the finance office--could I rent a car and charge it as travel expense? No--city buses are available. But I didn't know the bus system and it would take me hours to get to all the places I had to visit, I pleaded. You can take a cab if you want to pay for it out of your per diem was the answer. Nine dollars a day per diem and I should pay for a hotel room, meals, and taxi fares all over the District of Columbia. Besides, the lady in finance told me, my travel orders to Washington covered only a visit to the Pentagon. In addition, she said, I was supposed to be on my way back to Dayton right now, and if I didn't go through all the red tape of getting the orders amended I couldn't collect any per diem and technically I'd be AWOL. I couldn't talk to the finance officer, the lady informed me, because he always left at 4:30 to avoid the traffic and it was now exactly five o'clock and she was quitting. At five-one I decided that if saucers were buzzing Pennsylvania Avenue in formation I couldn't care less. I called Colonel Bower, explained my troubles, and said that I was through. He concurred, and I caught the next airliner to Dayton. When I returned I dropped in to see Captain Roy James in the radar branch and told him about the sighting. He said that he thought it sounded as if the radar targets had been caused by weather but since he didn't have the finer details he naturally couldn't make any definite evaluation. The good UFO reports that Lieutenant Flues had told me about when I called him from Washington had tripled in number before I got around to looking at them. Our daily take had risen to forty a day, and about a third of them were classified as unknowns. More amber-red fights like those seen on July 18 had been observed over the Guided Missile Long-Range Proving Ground at Patrick AFB, Florida. In Uvalde, Texas, a UFO described as "a large, round, silver object that spun on its vertical axis" was seen to cross 100 degrees of afternoon sky in forty-eight seconds. During part of its flight it passed between two towering cumulus clouds. At Los Alamos and Holyoke, Massachusetts, jets had chased UFO's. In both cases the UFO's had been lost as they turned into the sun. In two night encounters, one in New Jersey and one in Massachusetts, F-94's tried unsuccessfully to intercept unidentified lights reported by the Ground Observer Corps. In both cases the pilots of the radar- nosed jet interceptors saw a light; they closed in and their radar operators got a lock-on. But the lock-ons were broken in a few seconds, in both cases, as the light apparently took violent evasive maneuvers. Copies of these and other reports were going to the Pentagon, and I was constantly on the phone or having teleconferences with Major Fournet. When the second Washington National Sighting came along, almost a week to the hour from the first one, by a stroke of luck things weren't too fouled up. The method of reporting the sighting didn't exactly follow the official reporting procedures that are set forth in Air Force Letter 200-5, dated 5 April 1952, Subject: Reporting of Unidentified Flying Objects--but it worked. I first heard about the sighting about ten o'clock in the evening when I received a telephone call from Bob Ginna, _Life_ magazine's UFO expert. He had gotten the word from _Life's_ Washington News Bureau and wanted a statement about what the Air Force planned to do. I decided that instead of giving a mysterious "no comment" I would tell the truth: "I have no idea what the Air Force is doing; in all probability it's doing nothing." When he hung up, I called the intelligence duty officer in the Pentagon and I was correct, intelligence hadn't heard about the sighting. I asked the duty officer to call Major Fournet and ask him if he would go out to the airport, which was only two or three miles from his home. When he got the call from the duty officer Major Fournet called Lieutenant Holcomb; they drove to the ARTC radar room at National Airport and found Al Chop already there. So at this performance the UFO's had an official audience; Al Chop, Major Dewey Fournet, and Lieutenant Holcomb, a Navy electronics specialist assigned to the Air Force Directorate of Intelligence, all saw the radar targets and heard the radio conversations as jets tried to intercept the UFO's. Being in Dayton, 380 miles away, there wasn't much that I could do, but I did call Captain Roy James thinking possibly he might want to talk on the phone to the people who were watching the UFO's on the radarscopes. But Captain James has a powerful dislike for UFO's-- especially on Saturday night. About five o'clock Sunday morning Major Fournet called and told me the story of the second sighting at Washington National Airport: About 10:30P.M. on July 26 the same radar operators who had seen the UFO's the week before picked up several of the same slow-moving targets. This time the mysterious craft, if that is what they were, were spread out in an arc around Washington from Herndon, Virginia, to Andrews AFB. This time there was no hesitation in following the targets. The minute they appeared on the big 24-inch radarscope one of the controllers placed a plastic marker representing an unidentified target near each blip on the scope. When all the targets had been carefully marked, one of the controllers called the tower and the radar station at Andrews AFB--they also had the unknown targets. By 11:30P.M. four or five of the targets were continually being tracked at all times, so once again a call went out for jet interceptors. Once again there was some delay, but by midnight two F- 94's from New Castle County AFB were airborne and headed south. The reporters and photographers were asked to leave the radar room on the pretext that classified radio frequencies and procedures were being used in vectoring the interceptors. All civilian air traffic was cleared out of the area and the jets moved in. When I later found out that the press had been dismissed on the grounds that the procedures used in an intercept were classified, I knew that this was absurd because any ham radio operator worth his salt could build equipment and listen in on any intercept. The real reason for the press dismissal, I learned, was that not a few people in the radar room were positive that this night would be the big night in UFO history--the night when a pilot would close in on and get a good look at a UFO--and they didn't want the press to be in on it. But just as the two '94's arrived in the area the targets disappeared from the radarscopes. The two jets were vectored into the areas where the radar had shown the last target plots, but even though the visibility was excellent they could see nothing. The two airplanes stayed around a few minutes more, made a systematic search of the area, but since they still couldn't see anything or pick up anything on their radars they returned to their base. A few minutes after the F-94's left the Washington area, the unidentified targets were back on the radarscopes in that same area. What neither Major Fournet nor I knew at this time was that a few minutes after the targets left the radarscopes in Washington people in the area around Langley AFB near Newport News, Virginia, began to call Langley Tower to report that they were looking at weird bright lights that were "rotating and giving off alternating colors." A few minutes after the calls began to come in, the tower operators themselves saw the same or a similar light and they called for an interceptor. An F-94 in the area was contacted and visually vectored to the light by the tower operators. The F-94 saw the light and started toward it, but suddenly it went out, "like somebody turning off a light bulb." The F-94 crew continued their run and soon got a radar lock-on, but it was broken in a few seconds as the target apparently sped away. The fighter stayed in the area for several more minutes and got two more lock-ons, only to have them also broken after a few seconds. A few minutes after the F-94 over Newport News had the last lock-on broken, the targets came back on the scopes at Washington National. With the targets back at Washington the traffic controller again called Air Defense Command, and once again two F-94's roared south toward Washington. This time the targets stayed on the radarscopes when the airplanes arrived. The controllers vectored the jets toward group after group of targets, but each time, before the jets could get close enough to see anything more than just a light, the targets had sped away. Then one stayed put. The pilot saw a light right where the ARTC radar said a target was located; he cut in the F-94's afterburner and went after it, but just like the light that the F-94 had chased near Langley AFB, this one also disappeared. All during the chase the radar operator in the F-94 was trying to get the target on his set but he had no luck. After staying in the area about twenty minutes, the jets began to run low on fuel and returned to their base. Minutes later it began to get light, and when the sun came up all the targets were gone. Early Sunday morning, in an interview with the press, the Korean veteran who piloted the F-94, Lieutenant William Patterson, said: I tried to make contact with the bogies below 1,000 feet, but they [the radar controllers] vectored us around. I saw several bright lights. I was at my maximum speed, but even then I had no closing speed. I ceased chasing them because I saw no chance of overtaking them. I was vectored into new objects. Later I chased a single bright light which I estimated about 10 miles away. I lost visual contact with it about 2 miles. When Major Fournet finished telling me about the night's activity, my first question was, "How about the radar targets--could they have been caused by weather?" I knew that Lieutenant Holcomb was a sharp electronics man and that Major Fournet, although no electronics specialist, was a crackerjack engineer, so their opinion meant a lot. Dewey said that everybody in the radar room was convinced that the targets were very probably caused by solid metallic objects. There had been weather targets on the scope too, he said, but these were common to the Washington area and the controllers were paying no attention to them. And this something solid could poke along at 100 miles an hour or outdistance a jet, I thought to myself. I didn't ask Dewey any more because he'd been up all night and wanted to get to bed. Monday morning Major Ed Gregory, another intelligence officer at ATIC, and I left for Washington, but our flight was delayed in Dayton so we didn't arrive until late afternoon. On the way through the terminal building to get a cab downtown, I picked up the evening papers. Every headline was about the UFO's: FIERY OBJECTS OUTRUN JETS OVER CAPITAL--INVESTIGATION VEILED IN SECRECY FOLLOWING VAIN CHASE JETS ALERTED FOR SAUCERS--INTERCEPTORS CHASE LIGHTS IN D.C. SKIES EXPERT HERE TO PUSH STUDY AS OBJECTS IN SKIES REPORTED AGAIN I jokingly commented about wondering who the expert was. In a half hour I found out--I was. When Major Gregory and I walked into the lobby of the Roger Smith Hotel to check in, reporters and photographers rose from the easy chairs and divans like a covey of quail. They wanted my secrets, but I wasn't going to tell nor would I pose for pictures while I wasn't telling anything. Newspaper reporters are a determined lot, but Greg ran interference and we reached the elevator without even a "no comment." The next day was one of confusion. After the first Washington sighting the prevailing air in the section of the Pentagon's fourth floor, which is occupied by Air Force Intelligence, could be described as excitement, but this day it was confusion. There was a maximum of talk and a minimum of action. Everyone agreed that both sightings should be thoroughly investigated, but nobody did anything. Major Fournet and I spent the entire morning "just leaving" for somewhere to investigate "something." Every time we would start to leave, something more pressing would come up. About 10:00A.M. the President's air aide, Brigadier General Landry, called intelligence at President Truman's request to find out what was going on. Somehow I got the call. I told General Landry that the radar target could have been caused by weather but that we had no proof. To add to the already confused situation, new UFO reports were coming in hourly. We kept them quiet mainly because we weren't able to investigate them right away, or even confirm the facts. And we wanted to confirm the facts because some of the reports, even though they were from military sources, were difficult to believe. Prior to the Washington sightings in only a very few of the many instances in which radar had picked up UFO targets had the targets themselves supposedly been seen visually. Radar experts had continually pointed out this fact to us as an indication that maybe all of the radar targets were caused by freak weather conditions. "If people had just seen a light, or an object, near where the radar showed the UFO target to be, you would have a lot more to worry about," radar technicians had told me many times. Now people were seeing the same targets that the radars were picking up, and not just at Washington. On the same night as the second Washington sighting we had a really good report from California. An ADC radar had picked up an unidentified target and an F-94C had been scrambled. The radar vectored the jet interceptor into the target, the radar operator in the '94 locked-on to it, and as the airplane closed in the pilot and RO saw that they were headed directly toward a large, yellowish- orange light. For several minutes they played tag with the UFO. Both the radar on the ground and the radar in the F-94 showed that as soon as the airplane would get almost within gunnery range of the UFO it would suddenly pull away at a terrific speed. Then in a minute or two it would slow down enough to let the F-94 catch it again. When I talked to the F-94 crew on the phone, the pilot said that they felt as if this were just a big aerial cat-and-mouse game--and they didn't like it--at any moment they thought the cat might have pounced. Needless to say, this was an unknown. About midmorning on Tuesday, July 29th, Major General John Samford sent word down that he would hold a press conference that afternoon in an attempt to straighten out the UFO situation with the press. Donald Keyhoe reports on the press conference and the events leading up to it in detail in his book, _Flying_ _Saucers_ _from_ _Outer_ _Space_. He indicates that before the conference started, General Samford sat behind his big walnut desk in Room 3A138 in the Pentagon and battled with his conscience. Should he tell the public "the real truth"--that our skies are loaded with spaceships? No, the public might panic. The only answer would be to debunk the UFO's. This bit of reporting makes Major Keyhoe the greatest journalist in history. This beats wire tapping. He reads minds. And not only that, he can read them right through the walls of the Pentagon. But I'm glad that Keyhoe was able to read the General's mind and that he wrote the true and accurate facts about what he was really thinking because I spent quite a bit of time talking to the General that day and he sure fooled me. I had no idea he was worried about what he should tell the public. When the press conference, which was the largest and longest the Air Force had held since World War II, convened at 4:00P.M., General Samford made an honest effort to straighten out the Washington National Sightings, but the cards were stacked against him before he started. He had to hedge on many answers to questions from the press because he didn't know the answers. This hedging gave the impression that he was trying to cover up something more than just the fact that his people had fouled up in not fully investigating the sightings. Then he had brought in Captain Roy James from ATIC to handle all the queries about radar. James didn't do any better because he'd just arrived in Washington that morning and didn't know very much more about the sightings than he'd read in the papers. Major Dewey Fournet and Lieutenant Holcomb, who had been at the airport during the sightings, were extremely conspicuous by their absence, especially since it was common knowledge among the press that they weren't convinced the UFO's picked up on radars were weather targets. But somehow out of this chaotic situation came exactly the result that was intended--the press got off our backs. Captain James's answers about the possibility of the radar targets' being caused by temperature inversions had been construed by the press to mean that this was the Air Force's answer, even though today the twin sightings are still carried as unknowns. The next morning headlines from Bangor to Bogota read: AIR FORCE DEBUNKS SAUCERS AS JUST NATURAL PHENOMENA The Washington National Sightings proved one thing, something that many of us already knew: in order to forestall any more trouble similar to what we'd just been through we always had to get all of the facts and not try to hide them. A great deal of the press's interest was caused by the Air Force's reluctance to give out any information, and the reluctance on the part of the Air Force was caused by simply not having gone out to find the answers. But had someone gone out and made a more thorough investigation a few big questions would have popped up and taken some of the intrigue out of the two reports. It took me a year to put the question marks together because I just picked up the information as I happened to run across it, but it could have been collected in a day of concentrated effort. There was some doubt about the visual sighting of the "large fiery- orange-colored sphere" that the tower operators at Andrews AFB saw when the radar operators at National Airport told them they had a target over the Andrews Radio range station. When the tower operators were later interrogated they completely changed their story and said that what they saw was merely a star. They said that on the night of the sighting they "had been excited." (According to astronomical charts, there were no exceptionally bright stars where the UFO was seen over the range station, however. And I heard from a good source that the tower men had been "persuaded" a bit.) Then the pilot of the F-94C changed his mind even after he'd given the press and later told me his story about vainly trying to intercept unidentified lights. In an official report he says that all he saw was a ground light reflecting off a layer of haze. Another question mark arose about the lights that the airline pilots saw. Months after the sighting I heard from one of the pilots whom the ARTC controllers called to learn if he could see a UFO. This man's background was also impressive, he had been flying in and out of Washington since 1936. This is what he had to say: The most outstanding incident happened just after a take-off one night from Washington National. The tower man advised us that there was a UFO ahead of us on the take-off path and asked if we would aid in tracking it down. We were given headings to follow and shortly we were advised that we had passed the UFO and would be given a new heading. None of us in the cockpit had seen anything unusual. Several runs were made; each time the tower man advised us we were passing the UFO we noticed that we were over one certain section of the Potomac River, just east of Alexandria. Finally we were asked to visually check the terrain below for anything which might cause such an illusion. We looked and the only object we could see where the radar had a target turned out to be the Wilson Lines moonlight steamboat trip to Mount Vernon. Whether there was an altitude gimmick on the radar unit at the time I do not know but the radar was sure as hell picking up the steamboat. The pilot went on to say that there is such a conglomeration of lights around the Washington area that no matter where you look you see a "mysterious light." Then there was another point: although the radars at Washington National and Andrews overlap, and many of the targets appeared in the overlap area, only once did the three radars simultaneously pick up a target. The investigation brought out a few more points on the pro side too. We found out that the UFO's frequently visited Washington. On May 23 fifty targets had been tracked from 8:00 p.m. till midnight. They were back on the Wednesday night between the two famous Saturday- night sightings, the following Sunday night, and again the night of the press conference; then during August they were seen eight more times. On several occasions military and civilian pilots saw lights exactly where the radar showed the UFO's to be. On each night that there was a sighting there was a temperature inversion but it was never strong enough to affect the radar the way inversions normally do. On each occasion I checked the strength of the inversion according to the methods used by the Air Defense Command Weather Forecast Center. Then there was another interesting fact: hardly a night passed in June, July, and August in 1952 that there wasn't an inversion in Washington, yet the slow-moving, "solid" radar targets appeared on only a few nights. But the one big factor on the pro side of the question is the people involved--good radar men--men who deal in human lives. Each day they use their radar to bring thousands of people into Washington National Airport and with a responsibility like this they should know a real target from a weather target. So the Washington National Airport Sightings are still unknowns. Had the press been aware of some of the other UFO activity in the United States during this period, the Washington sightings might not have been the center of interest. True, they could be classed as good reports but they were not the best that we were getting. In fact, less than six hours after the ladies and gentlemen of the press said "Thank you" to General Samford for his press conference, and before the UFO's could read the newspapers and find out that they were natural phenomena, one of them came down across the Canadian border into Michigan. The incident that occurred that night was one of those that even the most ardent skeptic would have difficulty explaining. I've heard a lot of them try and I've heard them all fail. At nine-forty on the evening of the twenty-ninth an Air Defense Command radar station in central Michigan started to get plots on a target that was coming straight south across Saginaw Bay on Lake Huron at 625 miles an hour. A quick check of flight plans on file showed that it was an unidentified target. Three F-94's were in the area just northeast of the radar station, so the ground controller called one of the F-94's and told the pilot to intercept the unidentified target. The F-94 pilot started climbing out of the practice area on an intercept heading that the ground controller gave him. When the F-94 was at 20,000 feet, the ground controller told the pilot to turn to the right and he would be on the target. The pilot started to bring the F-94 around and at that instant both he and the radar operator in the back seat saw that they were turning toward a large bluish-white light, "many times larger than a star." In the next second or two the light "took on a reddish tinge, and slowly began to get smaller, as if it were moving away." Just then the ground controller called and said that he still had both the F-94 and the unidentified target on his scope and that the target had just made a tight 180-degree turn. The turn was too tight for a jet, and at the speed the target was traveling it would have to be a jet if it were an airplane. Now the target was heading back north. The F-94 pilot gave the engine full power and cut in the afterburner to give chase. The radar operator in the back seat got a good radar lock-on. Later he said, "It was just as solid a lock-on as you get from a B-36." The object was at 4 miles range and the F-94 was closing slowly. For thirty seconds they held the lock-on; then, just as the ground controller was telling the pilot that he was closing in, the light became brighter and the object pulled away to break the lock-on. Without breaking his transmission, the ground controller asked if the radar operator still had the lock-on because on the scope the distance between two blips had almost doubled in one sweep of the antenna. This indicated that the unknown target had almost doubled its speed in a matter of seconds. For ten minutes the ground radar followed the chase. At times the unidentified target would slow down and the F-94 would start to close the gap, but always, just as the F-94 was getting within radar range, the target would put on a sudden burst of speed and pull away from the pursuing jet. The speed of the UFO--for by this time all concerned had decided that was what it was--couldn't be measured too accurately because its bursts of speed were of such short duration; but on several occasions the UFO traveled about 4 miles in one ten- second sweep of the antenna, or about 1,400 miles an hour. The F-94 was getting low on fuel, and the pilot had to break off the chase a minute or two before the UFO got out of range of the ground radar. The last few plots on the UFO weren't too good but it looked as if the target slowed down to 200 to 300 miles an hour as soon as the F-94 turned around. What was it? It obviously wasn't a balloon or a meteor. It might have been another airplane except that in 1952 there was nothing flying, except a few experimental airplanes that were far from Michigan, that could so easily outdistance an F-94. Then there was the fact that radar clocked it at 1,400 miles an hour. The F-94 was heading straight for the star Capella, which is low on the horizon and is very brilliant, but what about the radar contacts? Some people said "Weather targets," but the chances of a weather target's making a 180-degree turn just as an airplane turns into it, giving a radar lock-on, then changing speed to stay just out of range of the airplane's radar, and then slowing down when the airplane leaves is as close to nil as you can get. What was it? A lot of people I knew were absolutely convinced this report was the key--the final proof. Even if all of the thousands of other UFO reports could be discarded on a technicality, this one couldn't be. These people believed that this report in itself was proof enough to officially accept the fact that UFO's were interplanetary spaceships. And when some people refused to believe even this report, the frustration was actually pitiful to see. As the end of July approached, there was a group of officers in intelligence fighting hard to get the UFO "recognized." At ATIC, Project Blue Book was still trying to be impartial--but sometimes it was difficult. CHAPTER THIRTEEN Hoax or Horror? To the military and the public who weren't intimately associated with the higher levels of Air Force Intelligence during the summer of 1952--and few were--General Samford's press conference seemed to indicate the peak in official interest in flying saucers. It did take the pressure off Project Blue Book--reports dropped from fifty per day to ten a day inside of a week--but behind the scenes the press conference was only the signal for an all-out drive to find out more about the UFO. Work on the special cameras continued on a high- priority basis, and General Samford directed us to enlist the aid of top-ranking scientists. During the past four months we had collected some 750 comparatively well-documented reports, and we hoped that something in these reports might give us a good lead on the UFO. My orders were to tell the scientists to whom we talked that the Air Force was officially still very much interested in the UFO and that their assistance, even if it was only in giving us ideas and comments on the reports, was badly needed. Although the statement of the problem was worded much more loosely, in essence it was, "Do the UFO reports we have collected indicate that the earth is being visited by a people from another planet?" Such questions had been asked of the scientists before, but not in such a serious vein. Then a secondary program was to be started, one of "educating" the military. The old idea that UFO reports would die out when the thrill wore off had long been discarded. We all knew that UFO reports would continue to come in and that in order to properly evaluate them we had to have every shred of evidence. The Big Flap had shown us that our chances of getting a definite answer on a sighting was directly proportional to the quality of the information we received from the intelligence officers in the field. But soon after the press conference we began to get wires from intelligence officers saying they had interpreted the newspaper accounts of General Samford's press conference to mean that we were no longer interested in UFO reports. A few other intelligence officers had evidently also misinterpreted the general's remarks because their reports of excellent sightings were sloppy and incomplete. All of this was bad, so to forestall any misconceived ideas about the future of the Air Force's UFO project, summaries of General Samford's press conference were distributed to intelligence officers. General Samford had outlined the future of the UFO project when he'd said: "So our present course of action is to continue on this problem with the best of our ability, giving it the attention that we feel it very definitely warrants. We will give it adequate attention, but not frantic attention." The summary of the press conference straightened things out to some extent and our flow of reports got back to normal. I was anxious to start enlisting the aid of scientists, as General Samford had directed, but before this could be done we had a backlog of UFO reports that had to be evaluated. During July we had been swamped and had picked off only the best ones. Some of the reports we were working on during August had simple answers, but many were unknowns. There was one report that was of special interest because it was an excellent example of how a UFO report can at first appear to be absolutely unsoluble then suddenly fall apart under thorough investigation. It also points up the fact that our investigation and analysis were thorough and that when we finally stamped a report "Unknown" it was unknown. We weren't infallible but we didn't often let a clue slip by. At exactly ten forty-five on the morning of August 1, 1952, an ADC radar near Bellefontaine, Ohio, picked up a high-speed unidentified target moving southwest, just north of Dayton. Two F-86's from the 97th Fighter-Interceptor Squadron at Wright-Patterson were scrambled and in a few minutes they were climbing out toward where the radar showed the UFO to be. The radar didn't have any height-finding equipment so all that the ground controller at the radar site could do was to get the two F-86's over or under the target, and then they would have to find it visually. When the two airplanes reached 30,000 feet, the ground controller called them and told them that they were almost on the target, which was still continuing its southwesterly course at about 525 miles an hour. In a few seconds the ground controller called back and told the lead pilot that the targets of his airplane and the UFO had blended on the radar-scope and that the pilot would have to make a visual search; this was as close in as radar could get him. Then the radar broke down and went off the air. But at almost that exact second the lead pilot looked up and there in the clear blue sky several thousand feet above him was a silver- colored sphere. The lead pilot pointed it out to his wing man and both of them started to climb. They went to their maximum altitude but they couldn't reach the UFO. After ten minutes of unsuccessful attempts to identify the huge silver sphere or disk--because at times it looked like a disk--one of the pilots hauled the nose of his F-86 up in a stall and exposed several feet of gun camera film. Just as he did this the warning light on his radar gun sight blinked on, indicating that something solid was in front of him--he wasn't photographing a sundog, hallucination, or refracted light. The two pilots broke off the intercept and started back to Wright- Patterson when they suddenly realized that they were still northwest of the base, in almost the same location they had been when they started the intercept ten minutes before. The UFO had evidently slowed down from the speed that the radar had measured, 525 miles an hour, until it was hovering almost completely motionless. As soon as the pilots were on the ground, the magazine of film from the gun camera was rushed to the photo lab and developed. The photos showed only a round, indistinct blob--no details--but they were proof that some type of unidentified flying object had been in the air north of Dayton. Lieutenant Andy Flues was assigned to this one. He checked the locations of balloons and found out that a 20-foot-diameter radiosonde weather balloon from Wright-Patterson had been very near the area when the unsuccessful intercept took place, but the balloon wasn't traveling 525 miles an hour and it couldn't be picked up by the ground radar, so he investigated further. The UFO couldn't have been another airplane because airplanes don't hover in one spot and it was no atmospheric phenomenon. Andy wrote it off as an unknown but it still bothered him; that balloon in the area was mighty suspicious. He talked to the two pilots a half dozen times and spent a day at the radar site at Bellefontaine before he reversed his "Unknown" decision and came up with the answer. The unidentified target that the radar had tracked across Ohio was a low-flying jet. The jet was unidentified because there was a mix-up and the radar station didn't get its flight plan. Andy checked and found that a jet out of Cleveland had landed at Memphis at about eleven-forty. At ten forty-five this jet would have been north of Dayton on a southwesterly heading. When the ground controller blended the targets of the two F-86's into the unidentified target, they were at 30,000 feet and were looking for the target at their altitude or higher so they missed the low-flying jet--but they did see the balloon. Since the radar went out just as the pilots saw the balloon, the ground controller couldn't see that the unidentified target he'd been watching was continuing on to the southwest. The pilots didn't bother to look around any more once they'd spotted the balloon because they thought they had the target in sight. The only part of the sighting that still wasn't explained was the radar pickup on the F-86's gun sight. Lieutenant Flues checked around, did a little experimenting, and found out that the small transmitter box on a radiosonde balloon will give an indication on the radar used in F-86 gun sights. To get a final bit of proof, Lieutenant Flues took the gun camera photos to the photo lab. The two F-86's had been at about 40,000 feet when the photos were taken and the 20-foot balloon was at about 70,000 feet. Andy's question to the photo lab was, "How big should a 20-foot balloon appear on a frame of 16-mm. movie film when the balloon is 30,000 feet away?" The people in the photo lab made a few calculations and measurements and came up with the answer, "A 20-foot balloon photographed from 30,000 feet away would be the same size as the UFO in the gun camera photos." By the middle of August, Project Blue Book was back to normal. Lieutenant Flues's Coca-Cola consumption had dropped from twenty bottles a day in mid-July to his normal five. We were all getting a good night's sleep and it was now a rare occasion when my home telephone would ring in the middle of the night to report a new UFO. But then on the morning of August 20 I was happily taking a shower, getting ready to go to work, when one of these rare occasions occurred and the phone rang--it was the ATIC OD. An operational immediate wire had just come in for Blue Book. He had gone over to the message center and gotten it. He thought that it was important and wanted me to come right out. For some reason he didn't want to read it over the phone, although it was not classified. I decided that if he said so I should come out, so I left in a hurry. The wire was from the intelligence officer at an air base in Florida. The previous night a scoutmaster and three boy scouts had seen a UFO. The scoutmaster had been burned when he approached too close to the UFO. The wire went on to give a few sketchy details and state that the scoutmaster was a "solid citizen." I immediately put in a long-distance call to the intelligence officer. He confirmed the data in the wire. He had talked briefly to the scoutmaster on the phone and from all he could gather it was no hoax. The local police had been contacted and they verified the story and the fact of the burns. I asked the intelligence officer to contact the scoutmaster and ask if he would submit to a physical examination immediately. I could imagine the rumors that could start about the scoutmaster's condition, and I wanted proof. The report sounded good, so I told the intelligence officer I'd get down to see him as soon as possible. I immediately called Colonel Dunn, then chief at ATIC, and gave him a brief rundown. He agreed that I should go down to Florida as soon as possible and offered to try to get an Air Force B-25, which would save time over the airlines. I told Bob Olsson to borrow a Geiger counter at Wright Field, then check out a camera. I called my wife and asked her to pack a few clothes and bring them out to me. Bob got the equipment, ran home and packed a bag, and in two hours he and I and our two pilots, Captain Bill Hoey and Captain David Douglas, were on our way to Florida to investigate one of the weirdest UFO reports that I came up against. When we arrived, the intelligence officer arranged for the scoutmaster to come out to the air base. The latter knew we were coming, so he arrived at the base in a few minutes. He was a very pleasant chap, in his early thirties, not at all talkative but apparently willing to co-operate. While he was giving us a brief personal history, I had the immediate impression that he was telling the truth. He'd lived in Florida all of his life. He'd gone to a private military prep school, had some college, and then had joined the Marines. He told us that he had been in the Pacific most of the war and repeated some rather hairy stories of what he'd been through. After the war he'd worked as an auto mechanic, then gone to Georgia for a while to work in a turpentine plant. After returning to Florida, he opened a gas station, but some hard luck had forced him to sell out. He was now working as a clerk in a hardware store. Some months back a local church had decided to organize a boy scout troop and he had offered to be the scoutmaster. On the night before the weekly scout meeting had broken up early. He said that he had offered to give four of the boys a ride home. He had let one of the boys out when the conversation turned to a stock car race that was to take place soon. They talked about the condition of the track. It had been raining frequently, and they wondered if the track was flooded, so they drove out to look at it. Then they started south toward a nearby town to take another of the boys home. They took a black-top road about 10 miles inland from the heavily traveled coastal highway that passes through sparsely settled areas of scrub pine and palmetto thickets. They were riding along when the scoutmaster said that he noticed a light off to his left in the pines. He slowed down and asked the boys if they'd seen it; none of them had. He started to drive on, when he saw the lights again. This time all of the boys saw them too, so he stopped. He said that he wanted to go back into the woods to see what was going on, but that the boys were afraid to stay alone. Again he started to drive on, but in a few seconds decided he had to go back. So he turned the car around, went back, and parked beside the road at a point just opposite where he'd seen the lights. I stopped him at this point to find out a little bit more about why he'd decided to go back. People normally didn't go running off into palmetto thickets infested with rattlesnakes at night. He had a logical answer. The lights looked like an airplane crashing into the woods some distance away. He didn't believe that was what he saw, but the thought that this could be a possibility bothered him. After all, he had said, he was a scoutmaster, and if somebody was in trouble, his conscience would have bothered him the rest of his life if he hadn't investigated and it had been somebody in need of help. A fifteen-minute radio program had just started, and he told the boys that he was going to go into the woods, and that if he wasn't back by the time the program ended they should run down the road to a farmhouse that they had passed and get help. He got out and started directly into the woods, wearing a faded denim billed cap and carrying machete and two flashlights. One of the lights was a spare he carried in his back pocket. He had traveled about 50 yards off the road when he ran into a palmetto thicket, so he stopped and looked for a clear path. But finding none, he started pushing his way through the waist-high tangle of brush. When he stopped, he recalled later, he had first become aware of an odd odor. He couldn't exactly describe it to us, except to say that it was "sharp" or "pungent." It was very faint, actually more like a subconscious awareness at first. Another sensation he recalled after the incident was a very slight difference in temperature, hardly perceivable, like walking by a brick building in the evening after the sun has set. He hadn't thought anything about either the odor or the heat at the time but later, when they became important, he remembered them. Paying no attention to these sensations then, he pushed on through the brush, looking up occasionally to check the north star, so that he could keep traveling straight east. After struggling through about 30 yards of palmetto undergrowth, he noticed a change in the shadows ahead of him and stopped to shine the flashlight farther ahead of him to find out if he was walking into a clearing or into one of the many ponds that dot that particular Florida area. It was a clearing. The boy scouts in the car had been watching the scoutmaster's progress since they could see his light bobbing around. Occasionally he would shine it up at a tree or across the landscape for an instant, so they knew where he was in relation to the trees and thickets. They saw him stop at the edge of the open, shadowed area and shine his light ahead of him. The scoutmaster then told us that when he stopped this second time he first became consciously aware of the odor and the heat. Both became much more noticeable as he stepped into the clearing. In fact, the heat became almost unbearable or, as he put it, "oppressively moist, making it hard to breathe." He walked a few more paces and suddenly got a horrible feeling that somebody was watching him. He took another step, stopped, and looked up to find the north star. But he couldn't see the north star, or any stars. Then he suddenly saw that almost the whole sky was blanked out by a large dark shape about 30 feet above him. He said that he had stood in this position for several seconds, or minutes--he didn't know how long--because now the feeling of being watched had overcome any power of reasoning he had. He managed to step back a few paces, and apparently got out from under the object, because he could see the edge of it silhouetted against the sky. As he backed up, he said, the air became much cooler and fresher, helping him to think more clearly. He shone his light up at the edge of the object and got a quick but good look. It was circular-shaped and slightly concave on the bottom. The surface was smooth and a grayish color. He pointed to a gray linoleum-topped desk in the intelligence officer's room. "Just like that," he said. The upper part had a dome in the middle, like a turret. The edge of the saucer- shaped object was thick and had vanes spaced about every foot, like buckets on a turbine wheel. Between each vane was a small opening, like a nozzle. The next reaction that the scoutmaster recalled was one of fury. He wanted to harm or destroy whatever it was that he saw. All he had was a machete, but he wanted to try to jump up and strike at whatever he was looking at. No sooner did he get this idea than he noticed the shadows on the turret change ever so slightly and heard a sound, "like the opening of a well-oiled safe door." He froze where he stood and noticed a small ball of red fire begin to drift toward him. As it floated down it expanded into a cloud of red mist. He dropped his fight and machete, and put his arms over his face. As the mist enveloped him, he passed out. The boy scouts, in the car, estimated that their scoutmaster had been gone about five minutes when they saw him stop at the edge of the clearing, then walk on in. They saw him stop seconds later, hesitate a few more seconds, then shine the light up in the air. They thought he was just looking at the trees again. The next thing they said they saw was a big red ball of fire engulfing him. They saw him fall, so they spilled out of the car and took off down the road toward the farmhouse. The farmer and his wife had a little difficulty getting the story out of the boys, they were so excited. All they could get was something about the boys' scoutmaster being in trouble down the road. The farmer called the Florida State Highway Patrol, who relayed the message to the county sheriff's office. In a few minutes a deputy sheriff and the local constable arrived. They picked up the scouts and drove to where their car was parked. The scoutmaster had no idea of how long he had been unconscious. He vaguely remembered leaning against a tree, the feeling of wet, dew- covered grass, and suddenly regaining his consciousness. His first reaction was to get out to the highway, so he started to run. About halfway through the palmetto thicket he saw a car stop on the highway. He ran toward it and found the deputy and constable with the boys. He was so excited he could hardly get his story told coherently. Later the deputy said that in all his years as a law-enforcement officer he had never seen anyone as scared as the scoutmaster was as he came up out of the ditch beside the road and walked into the glare of the headlights. As soon as he'd told his story, they all went back into the woods, picking their way around the palmetto thicket. The first thing they noticed was the flashlight, still burning, in a clump of grass. Next to it was a place where the grass was flattened down, as if a person had been lying there. They looked around for the extra light that the scoutmaster had been carrying, but it was gone. Later searches for this missing flashlight were equally fruitless. They marked the spot where the crushed grass was located and left. The constable took the boy scouts home and the scoutmaster followed the deputy to the sheriff's office. On the way to town the scoutmaster said he first noticed that his arms and face burned. When he arrived at the sheriff's office, he found that his arms, face, and cap _were_ burned. The deputy called the Air Force. There were six people listening to his story. Bob Olsson, the two pilots, the intelligence officer, his sergeant, and I. We each had previously agreed to pick one insignificant detail from the story and then re-question the scoutmaster when he had finished. Our theory was that if he had made up the story he would either repeat the details perfectly or not remember what he'd said. I'd used this many times before, and it was a good indicator of a lie. He passed the test with flying colors. His story sounded good to all of us. We talked for about another hour, discussing the event and his background. He kept asking, "What did I see?"--evidently thinking that I knew. He said that the newspapers were after him, since the sheriff's office had inadvertently leaked the story, but that he had been stalling them off pending our arrival. I told him it was Air Force policy to allow people to say anything they wanted to about a UFO sighting. We had never muzzled anyone; it was his choice. With that, we thanked him, arranged to pick up the cap and machete to take back to Dayton, and sent him home in a staff car. By this time it was getting late, but I wanted to talk to the flight surgeon who had examined the man that morning. The intelligence officer found him at the hospital and he said he would be right over. His report was very thorough. The only thing he could find out of the ordinary were minor burns on his arms and the back of his hands. There were also indications that the inside of his nostrils might be burned. The degree of burn could be compared to a light sunburn. The hair had also been singed, indicating a flash heat. The flight surgeon had no idea how this specifically could have happened. It could have even been done with a cigarette lighter, and he took his lighter and singed a small area of his arm to demonstrate. He had been asked only to make a physical check, so that is what he'd done, but he did offer a suggestion. Check his Marine records; something didn't ring true. I didn't quite agree; the story sounded good to me. The next morning my crew from ATIC, three people from the intelligence office, and the two law officers went out to where the incident had taken place. We found the spot where somebody had apparently been lying and the scoutmaster's path through the thicket. We checked the area with a Geiger counter, as a precautionary measure, not expecting to find anything; we didn't. We went over the area inch by inch, hoping to find a burned match with which a flare or fireworks could have been lighted, drippings from a flare, or anything that shouldn't have been in a deserted area of woods. We looked at the trees; they hadn't been hit by lightning. The blades of grass under which the UFO supposedly hovered were not burned. We found nothing to contradict the story. We took a few photos of the area and went back to town. On the way back we talked to the constable and the deputy. All they could do was to confirm what we'd heard. We talked to the farmer and his wife, but they couldn't help. The few facts that the boy scouts had given them before they had a chance to talk to their scoutmaster correlated with his story. We talked to the scoutmaster's employer and some of his friends; he was a fine person. We questioned people who might have been in a position to also observe something; they saw nothing. The local citizens had a dozen theories, and we thoroughly checked each one. He hadn't been struck by lightning. He hadn't run across a still. There was no indication that he'd surprised a gang of illegal turtle butcherers, smugglers, or bootleggers. There was no indication of marsh gas or swamp fire. The mysterious blue lights in the area turned out to be a farmer arc-welding at night. The other flying saucers were the landing lights of airplanes landing at a nearby airport. To be very honest, we were trying to prove that this was a hoax, but were having absolutely no success. Every new lead we dug up pointed to the same thing, a true story. We finished our work on a Friday night and planned to leave early Saturday morning. Bob Olsson and I planned to fly back on a commercial airliner, as the B-25 was grounded for maintenance. Just after dinner that night I got a call from the sheriff's office. It was from a deputy I had talked to, not the one who met the scoutmaster coming out of the woods, but another one, who had been very interested in the incident. He had been doing a little independent checking and found that our singed UFO observer's background was not as clean as he led one to believe. He had been booted out of the Marines after a few months for being AWOL and stealing an automobile, and had spent some time in a federal reformatory in Chillicothe, Ohio. The deputy pointed out that this fact alone meant nothing but that he thought I might be interested in it. I agreed. The next morning, early, I was awakened by a phone call from the intelligence officer. The morning paper carried the UFO story on the front page. It quoted the scoutmaster as saying that "high brass" from Washington had questioned him late into the night. There was no "high brass," just four captains, a second lieutenant, and a sergeant. He knew we were from Dayton because we had discussed who we were and where we were stationed. The newspaper story went on to say that "he, the scoutmaster, and the Air Force knew what he'd seen but he couldn't tell--it would create a national panic." He'd also hired a press agent. I could understand the "high brass from the Pentagon" as literary license by the press, but this "national panic" pitch was too much. I had just about decided to give up on this incident and write it off as "Unknown" until this happened. From all appearances, our scoutmaster was going to make a fast buck on his experience. Just before leaving for Dayton, I called Major Dewey Fournet in the Pentagon and asked him to do some checking. Monday morning the machete went to the materials lab at Wright- Patterson. The question we asked was, "Is there anything unusual about this machete? Is it magnetized? Is it radioactive? Has it been heated?" No knife was ever tested so thoroughly for so many things. As in using a Geiger counter to check the area over which the UFO had hovered in the Florida woods, our idea was to investigate every possible aspect of the sighting. They found nothing, just a plain, unmagnetized, unradioactive, unheated, common, everyday knife. The cap was sent to a laboratory in Washington, D.C., along with the scoutmaster's story. Our question here was, "Does the cap in any way (burns, chemicals, etc.) substantiate or refute the story?" I thought that we'd collected all the items that could be analyzed in a lab until somebody thought of one I'd missed, the most obvious of them all--soil and grass samples from under the spot where the UFO had hovered. We'd had samples, but in the last-minute rush to get back to Dayton they had been left in Florida. I called Florida and they were shipped to Dayton and turned over to an agronomy lab for analysis. By the end of the week I received a report on our ex-Marine's military and reformatory records. They confirmed a few suspicions and added new facts. They were not complimentary. The discrepancy between what we'd heard about the scoutmaster while we were in Florida and the records was considered a major factor. I decided that we should go back to Florida and try to resolve this discrepancy. Since it was hurricane season, we had to wait a few days, then sneak back between two hurricanes. We contacted a dozen people in the city where the scoutmaster lived. All of them had known him for some time. We traced him from his early boyhood to the time of the sighting. To be sure that the people we talked to were reliable, we checked on them. The specific things we found out cannot be told since they were given to us in confidence, but we were convinced that the whole incident was a hoax. We didn't talk to the scoutmaster again but we did talk to all the boy scouts one night at their scout meeting, and they retold how they had seen their scoutmaster knocked down by the ball of fire. The night before, we had gone out to the area of the sighting and, under approximately the same lighting conditions as existed on the night of the sighting, had re-enacted the scene--especially the part where the boy scouts saw their scoutmaster fall, covered with red fire. We found that not even by standing _on_ _top_ _of_ _the_ _car_ could you see a person silhouetted in the clearing where the scoutmaster supposedly fell. The rest of their stories fell apart to some extent too. They were not as positive of details as they had been previously. When we returned to Dayton, the report on the cap had come back. The pattern of the scorch showed that the hat was flat when it was scorched, but the burned holes--the lab found some minute holes we had missed--had very probably been made by an electrical spark. This was all the lab could find. During our previous visit we repeatedly asked the question, "Was the hat burned before you went into the woods?" and, "Had the cap been ironed?" We had received the same answers each time: "The hat was not burned because we [the boy scouts] were playing with it at the scout meeting and would have noticed the burns," and, "The cap was new; it had not been washed or ironed." It is rumored that the cap was never returned because it was proof of the authenticity of the sighting. The hat wasn't returned simply because the scoutmaster said that he didn't want it back. No secrets, no intrigue; it's as simple as that. Everyone who was familiar with the incident, except a few people in the Pentagon, were convinced that this was a hoax until the lab called me about the grass samples we'd sent in. "How did the roots get charred?" Roots charred? I didn't even know what my caller was talking about. He explained that when they'd examined the grass they had knocked the dirt and sand off the roots of the grass clumps and found them charred. The blades of grass themselves were not damaged; they had never been heated, except on the extreme tips of the longer blades. These had evidently been bending over touching the ground and were also charred. The lab had duplicated the charring and had found that by placing live grass clumps in a pan of sand and dirt and heating it to about 300 degrees F. over a gas burner the charring could be duplicated. How it was actually done outside the lab they couldn't even guess. As soon as we got the lab report, we checked a few possibilities ourselves. There were no hot underground springs to heat the earth, no chemicals in the soil, not a thing we found could explain it. The only way it could have been faked would have been to heat the earth from underneath to 300 degrees F., and how do you do this without using big and cumbersome equipment and disturbing the ground? You can't. Only a few people handled the grass specimens: the lab, the intelligence officer in Florida, and I. The lab wouldn't do it as a joke, then write an official report, and I didn't do it. This leaves the intelligence officer; I'm positive that he wouldn't do it. There may be a single answer everyone is overlooking, but as of now the charred grass roots from Florida are still a mystery. Writing an official report on this incident was difficult. On one side of the ledger was a huge mass of circumstantial evidence very heavily weighted against the scoutmaster's story being true. On our second trip to Florida, Lieutenant Olsson and I heard story after story about the man's aptitude for dreaming up tall tales. One man told us, "If he told me the sun was shining, I'd look up to make sure." There were parts of his story and those of the boy scouts that didn't quite mesh. None of us ever believed the boy scouts were in on the hoax. They were undoubtedly so impressed by the story that they imagined a few things they didn't actually see. The scoutmaster's burns weren't proof of anything; the flight surgeon had duplicated these by burning his own arm with a cigarette lighter. But we didn't make step one in proving the incident to be a hoax. We thought up dozens of ways that the man could have set up the hoax but couldn't prove one. In the scoutmaster's favor were the two pieces of physical evidence we couldn't explain, the holes burned in the cap and the charred grass roots. The deputy sheriff who had first told me about the scoutmaster's Marine and prison record had also said, "Maybe this is the one time in his life he's telling the truth, but I doubt it." So did we; we wrote off the incident as a hoax. The best hoax in UFO history. Many people have asked why we didn't give the scoutmaster a lie detector test. We seriously considered it and consulted some experts in this field. They advised against it. In some definite types of cases the lie detector will not give valid results. This, they thought, was one of those cases. Had we done it and had he passed on the faulty results, the publicity would have been a headache. There is one way to explain the charred grass roots, the burned cap, and a few other aspects of the incident. It's pure speculation; I don't believe that it is the answer, yet it is interesting. Since the blades of the grass were not damaged and the ground had not been disturbed, this one way is the only way (nobody has thought of any other way) the soil could have been heated. It could have been done by induction heating. To quote from a section entitled "Induction Heating" from an electrical engineering textbook: A rod of solid metal or any electrical conductor, when subjected to an alternating magnetic field, has electromotive forces set up in it. These electromotive forces cause what are known as "eddy currents." A rise in temperature results from "eddy currents." Induction heating is a common method of melting metals in a foundry. Replace the "rod of solid metal" mentioned above with damp sand, an electrical conductor, and assume that a something that was generating a powerful alternating magnetic field was hovering over the ground, and you can explain how the grass roots were charred. To get an alternating magnetic field, some type of electrical equipment was needed. Electricity--electrical sparks--the holes burned in the cap "by electric sparks." UFO propulsion comes into the picture when one remembers Dr. Einstein's unified field theory, concerning the relationship between electro-magnetism and gravitation. If this alternating magnetic field can heat metal, why didn't everything the scoutmaster had that was metal get hot enough to burn him? He had a flashlight, machete, coins in his pocket, etc. The answer--he wasn't under the UFO for more than a few seconds. He said that when he stopped to really look at it he had backed away from under it. He did feel some heat, possibly radiating from the ground. To further pursue this line of speculation, the scoutmaster repeatedly mentioned the unusual odor near the UFO. He described it as being "sharp" or "pungent." Ozone gas is "sharp" or "pungent." To quote from a chemistry book, "Ozone is prepared by passing air between two plates which are charged at a high electrical potential." Electrical equipment again. Breathing too high a concentration of ozone gas will also cause you to lose consciousness. I used to try out this induction heating theory on people to get their reaction. I tried it out one day on a scientist from Rand. He practically leaped at the idea. I laughed when I explained that I thought this theory just _happened_ to tie together the unanswered aspects of the incident in Florida and was not the answer; he was slightly perturbed. "What do you want?" he said. "Does a UFO have to come in and land on your desk at ATIC?" CHAPTER FOURTEEN Digesting the Data It was soon after we had written a finis to the Case of the Scoutmaster that I went into Washington to give another briefing on the latest UFO developments. Several reports had come in during early August that had been read with a good deal of interest in the military and other governmental agencies. By late August 1952 several groups in Washington were following the UFO situation very closely. The sighting that had stirred everyone up came from Haneda AFB, now Tokyo International Airport, in Japan. Since the sighting came from outside the U.S., we couldn't go out and investigate it, but the intelligence officers in the Far East Air Force had done a good job, so we had the complete story of this startling account of an encounter with a UFO. Only a few minor questions had been unanswered, and a quick wire to FEAF brought back these missing data. Normally it took up to three months to get routine questions back and forth, but this time the exchange of wires took only a matter of hours. Several months after the sighting I talked to one of the FEAF intelligence officers who had investigated it, and in his estimation it was one of the best to come out of the Far East. The first people to see the UFO were two control tower operators who were walking across the ramp at the air base heading toward the tower to start the midnight shift. They were about a half hour early so they weren't in any big hurry to get up into the tower--at least not until they saw a large brilliant light off to the northeast over Tokyo Bay. They stopped to look at the light for a few seconds thinking that it might be an exceptionally brilliant star, but both men had spent many lonely nights in a control tower when they had nothing to look at except stars and they had never seen anything this bright before. Besides, the light was moving. The two men had lined it up with the corner of a hangar and could see that it was continually moving closer and drifting a little off to the right. In a minute they had run across the ramp, up the several hundred steps to the tower, and were looking at the light through 7x50 binoculars. Both of the men, and the two tower operators whom they were relieving, got a good look at the UFO. The light was circular in shape and had a constant brilliance. It appeared to be the upper portion of a large, round, dark shape which was about four times the diameter of the light itself. As they watched, the UFO moved in closer, or at least it appeared to be getting closer because it became more distinct. When it moved in, the men could see a second and dimmer light on the lower edge of the dark, shadowy portion. In a few minutes the UFO had moved off to the east, getting dimmer and dimmer as it disappeared. The four tower men kept watching the eastern sky, and suddenly the light began to reappear. It stayed in sight a few seconds, was gone again, and then for the third time it came back, heading toward the air base. This time one of the tower operators picked up a microphone, called the pilot of a C-54 that was crossing Tokyo Bay, and asked if he could see the light. The pilot didn't see anything unusual. At 11:45P.M., according to the logbook in the tower, one of the operators called a nearby radar site and asked if they had an unidentified target on their scopes. They did. The FEAF intelligence officers who investigated the sighting made a special effort to try to find out if the radar's unidentified target and the light were the same object. They deduced that they were since, when the tower operators and the radar operators compared notes over the telephone, the light and the radar target were in the same location and were moving in the same direction. For about five minutes the radar tracked the UFO as it cut back and forth across the central part of Tokyo Bay, sometimes traveling so slowly that it almost hovered and then speeding up to 300 miles an hour. All of this time the tower operators were watching the light through binoculars. Several times when the UFO approached the radar station--once it came within 10 miles--a radar operator went outside to find out if he could see the light but no one at the radar site ever saw it. Back at the air base the tower operators had called other people and they saw the light. Later on the tower man said that he had the distinct feeling that the light was highly directional, like a spotlight. Some of the people who were watching thought that the UFO might be a lighted balloon; so, for the sake of comparison, a lighted weather balloon was released. But the light on the balloon was much more "yellowish" than the UFO and in a matter of seconds it had traveled far enough away that the light was no longer visible. This gave the observers a chance to compare the size of the balloon and the size of the dark, shadowy part of the UFO. Had the UFO been 10 miles away it would have been 50 feet in diameter. Three minutes after midnight an F-94 scrambled from nearby Johnson AFB came into the area. The ground controller sent the F-94 south of Yokohama, up Tokyo Bay, and brought him in "behind" the UFO. The second that the ground controller had the F-94 pilot lined up and told him that he was in line for a radar run, the radar operator in the rear seat of the F-94 called out that he had a lock-on. His target was at 6,000 yards, 10 degrees to the right and 10 degrees below the F-94. The lock-on was held for ninety seconds as the ground controller watched both the UFO and the F-94 make a turn and come toward the ground radar site. Just as the target entered the "ground clutter"--the permanent and solid target near the radar station caused by the radar beam's striking the ground--the lock-on was broken. The target seemed to pull away swiftly from the jet interceptor. At almost this exact instant the tower operators reported that they had lost visual contact with the UFO. The tower called the F-94 and asked if they had seen anything visually during the chase--they hadn't. The F-94 crew stayed in the area ten or fifteen more minutes but couldn't see anything or pick up any more targets on their radar. Soon after the F-94 left the area, both the ground radar and the tower operators picked up the UFO again. In about two minutes radar called the tower to say that their target had just "broken into three pieces" and that the three "pieces," spaced about a quarter of a mile apart, were leaving the area, going northeast. Seconds later tower operators lost sight of the light. The FEAF intelligence officers had checked every possible angle but they could offer nothing to account for the sighting. There were lots of opinions, weather targets for example, but once again the chances of a weather target's being in exactly the same direction as a bright star and having the star appear to move with the false radar target aren't too likely--to say the least. And then the same type of thing had happened twice before inside of a month's time, once in California and once in Michigan. As one of the men at the briefing I gave said, "It's incredible, and I can't believe it, but those boys in FEAF are in a war--they're veterans--and by damn, I think they know what they're talking about when they say they've never seen anything like this before." I could go into a long discourse on the possible explanations for this sighting; I heard many, but in the end there would be only one positive answer--the UFO could not be identified as something we knew about. It could have been an interplanetary spaceship. Many people thought this was the answer and were all for sticking their necks out and establishing a category of conclusions for UFO reports and labeling it spacecraft. But the majority ruled, and a UFO remained an _unidentified_ flying object. On my next trip to the Pentagon I spent the whole day talking to Major Dewey Fournet and two of his bosses, Colonel W. A. Adams and Colonel Weldon Smith, about the UFO subject in general. One of the things we talked about was a new approach to the UFO problem--that of trying to prove that the motion of a UFO as it flew through the air was intelligently controlled. I don't know who would get credit for originating the idea of trying to analyze the motion of the UFO's. It was one of those kinds of ideas that are passed around, with everyone adding a few modifications. We'd been talking about making a study of this idea for a long time, but we hadn't had many reports to work with; but now, with the mass of data that we had accumulated in June and July and August, the prospects of such a study looked promising. The basic aim of the study would be to learn whether the motion of the reported UFO's was random or ordered. Random motion is an unordered, helter-skelter motion very similar to a swarm of gnats or flies milling around. There is no apparent pattern or purpose to their flight paths. But take, for example, swallows flying around a chimney--they wheel, dart, and dip, but if you watch them closely, they have a definite pattern in their movements--an ordered motion. The definite pattern is intelligently controlled because they are catching bugs or getting in line to go down the chimney. By the fall of 1952 we had a considerable number of well-documented reports in which the UFO's made a series of maneuvers. If we could prove that these maneuvers were not random, but ordered, it would be proof that the UFO's were things that were intelligently controlled. During our discussion Major Fournet brought up two reports in which the UFO seemed to know what it was doing and wasn't just aimlessly darting around. One of these was the recent sighting from Haneda AFB, Japan, and the other was the incident that happened on the night of July 29, when an F-94 attempted to intercept a UFO over eastern Michigan. In both cases radar had established the track of the UFO. In the Haneda Incident, according to the sketch of the UFO's track, each turn the UFO made was constant and the straight "legs" between the turns were about the same length. The sketch of the UFO's flight path as it moved back and forth over Tokyo Bay reminded me very much of the "crisscross" search patterns we used to fly during World War II when we were searching for the crew of a ditched airplane. The only time the UFO seriously deviated from this pattern was when the F- 94 got on its tail. The Michigan sighting was even better, however. In this case there was a definite reason for every move that the UFO made. It made a 180- degree turn because the F-94 was closing on it head on. It alternately increased and decreased its speed, but every time it did this it was because the F-94 was closing in and it evidently put on speed to pull out ahead far enough to get out of range of the F-94's radar. To say that this motion was random and that it was just a coincidence that the UFO made the 180-degree turn when the F-94 closed in head on and that it was just a coincidence that the UFO speeded up every time the F-94 began to get within radar range is pushing the chance of coincidence pretty hard. The idea of the motion analysis study sounded interesting to me, but we were so busy on Project Blue Book we didn't have time to do it. So Major Fournet offered to look into it further and I promised him all the help we could give him. In the meantime my people in Project Blue Book were contacting various scientists in the U.S., and indirectly in Europe, telling them about our data, and collecting opinions. We did this in two ways. In the United States we briefed various scientific meetings and groups. To get the word to the other countries, we enlisted the gratis aid of scientists who were planning to attend conferences or meetings in Europe. We would brief these European-bound scientists on all of the aspects of the UFO problem so they could informally discuss the problem with their European colleagues. The one thing about these briefings that never failed to amaze me, although it happened time and time again, was the interest in UFO's within scientific circles. As soon as the word spread that Project Blue Book was giving official briefings to groups with the proper security clearances, we had no trouble in getting scientists to swap free advice for a briefing. I might add that we briefed only groups who were engaged in government work and who had the proper security clearances solely because we could discuss any government project that might be of help to us in pinning down the UFO. Our briefings weren't just squeezed in either; in many instances we would arrive at a place to find that a whole day had been set aside to talk about UFO's. And never once did I meet anyone who laughed off the whole subject of flying saucers even though publicly these same people had jovially sloughed off the press with answers of "hallucinations," "absurd," or "a waste of time and money." They weren't wild-eyed fans but they were certainly interested. Colonel S. H. Kirkland and I once spent a whole day briefing and talking to the Beacon Hill Group, the code name for a collection of some of the world's leading scientists and industrialists. This group, formed to consider and analyze the toughest of military problems, took a very serious interest in our project and gave much good advice. At Los Alamos and again at Sandia Base our briefings were given in auditoriums to standing room only crowds. In addition I gave my briefings at National Advisory Committee for Aeronautics laboratories, at Air Research and Development centers, at Office of Naval Research facilities and at the Air Force University. Then we briefed special groups of scientists. Normally scientists are a cautious lot and stick close to proven facts, keeping their personal opinions confined to small groups of friends, but when they know that there is a sign on a door that says "Classified Briefing in Progress," inhibitions collapse like the theories that explain all the UFO's away. People say just what they think. I could jazz up this part of the UFO story as so many other historians of the UFO have and say that Dr. So-and-So believes that the reported flying saucers are from outer space or that Dr. Whositz is firmly convinced that Mars is inhabited. I talked to plenty of Dr. So-and-So's who believed that flying saucers were real and who were absolutely convinced that other planets or bodies in the universe were inhabited, but we were looking for proven facts and not just personal opinions. However, some of the questions we asked the scientists had to be answered by personal opinions because the exact answers didn't exist. When such questions came up, about all we could do was to try to get the largest and most representative cross section of personal opinions upon which to base our decisions. In this category of questions probably the most frequently discussed was the possibility that other celestial bodies in the universe were populated with intelligent beings. The exact answer to this is that no one knows. But the consensus was that it wouldn't be at all surprising. All the briefings we were giving added to our work load because UFO reports were still coming in in record amounts. The lack of newspaper publicity after the Washington sightings had had some effect because the number of reports dropped from nearly 500 in July to 175 in August, but this was still far above the normal average of twenty to thirty reports a month. September 1952 started out with a rush, and for a while it looked as if UFO sightings were on the upswing again. For some reason, we never could determine why, we suddenly began to get reports from all over the southeastern United States. Every morning, for about a week or two, we'd have a half dozen or so new reports. Georgia and Alabama led the field. Many of the reports came from people in the vicinity of the then new super-hush-hush Atomic Energy Commission facility at Savannah River, Georgia. And many were coming from the port city of Mobile, Alabama. Our first thought, when the reports began to pour in, was that the newspapers in these areas were possibly stirring things up with scare stories, but our newspaper clipping service covered the majority of the southern papers, and although we kept looking for publicity, none showed up. In fact, the papers only barely mentioned one or two of the sightings. As they came in, each of the sighting reports went through our identification process; they were checked against all balloon flights, aircraft flights, celestial bodies, and the MO file, but more than half of them came out as unknowns. When the reports first began to come in, I had called the intelligence officers at all of the major military installations in the Southeast unsuccessfully trying to find out if they could shed any light on the cause of the sightings. One man, the man who was responsible for UFO reports made to Brookley AFB, just outside of Mobile, Alabama, took a dim view of all of the proceedings. "They're all nuts," he said. About a week later his story changed. It seems that one night, about the fourth night in a row that UFO's had been reported near Mobile, this man and several of his assistants decided to try to see these famous UFO's; about 10:00P.M., the time that the UFO's were usually reported, they were gathered around the telephone in the man's office at Brookley AFB. Soon a report came in. The first question that the investigator who answered the phone asked was, "Can you still see it?" The answer was "Yes," so the officer took off to see the UFO. The same thing happened twice more, and two more officers left for different locations. The fourth time the phone rang the call was from the base radar station. They were picking up a UFO on radar, so the boss himself took off. He saw the UFO in air out over Mobile Bay and he saw the return of the UFO on the radarscope. The next morning he called me at ATIC and for over an hour he told me what had happened. Never have I talked to four more ardent flying saucer believers. We did quite a bit of work on the combination radar-visual sighting at Brookley. First of all, radar-visual sightings were the best type of UFO sightings we received. There are no explanations for how radar can pick up a UFO target that is being watched visually at the same time. Maybe I should have said there are no proven explanations on how this can happen, because, like everything else associated with the UFO, there was a theory. During the Washington National Sightings several people proposed the idea that the same temperature-inversion layer that was causing the radar beam to bend down and pick up a ground target was causing the target to appear to be in the air. They went on to say that we couldn't get a radar-visual sighting unless the ground target was a truck, car, house, or something else that was lighted and could be seen at a great distance. The second reason the Brookley AFB sighting was so interesting was that it knocked this theory cold. The radar at Brookley AFB was so located that part of the area that it scanned was over Mobile Bay. It was in this area that the UFO was detected. We thought of the theory that the same inversion layer that bent the radar beam also caused the target to appear to be in the air, and we began to do a little checking. There was a slight inversion but, according to our calculations, it wasn't enough to affect the radar. More important was the fact that in the area where the target appeared there were no targets to pick up--let alone lighted targets. We checked and rechecked and found that at the time of the sighting there were no ships, buoys, or anything else that would give a radar return in the area of Mobile Bay in which we were interested. Although this sighting wasn't as glamorous as some we had, it was highly significant because it was possible to show that the UFO couldn't have been a lighted surface target. While we were investigating the sighting we talked to several electronics specialists about our radar-visual sightings. One of the most frequent comments we heard was, "Why do all of these radar- visual sightings occur at night?" The answer was simple: they don't. On August 1, just before dawn, an ADC radar station outside of Yaak, Montana, on the extreme northern border of the United States, picked up a UFO. The report was very similar to the sighting at Brookley except it happened in the daylight and, instead of seeing a light, the crew at the radar station saw a "dark, cigar-shaped object" right where the radar had the UFO pinpointed. What these people saw is a mystery to this day. Late in September I made a trip out to Headquarters, ADC to brief General Chidlaw and his staff on the past few months' UFO activity. Our plans for periodic briefings, which we had originally set up with ADC, had suffered a bit in the summer because we were all busy elsewhere. They were still giving us the fullest co-operation, but we hadn't been keeping them as thoroughly read in as we would have liked to. I'd finished the briefing and was eating lunch at the officers' club with Major Verne Sadowski, Project Blue Book's liaison officer in ADC Intelligence, and several other officers. I had a hunch that something was bothering these people. Then finally Major Sadowski said, "Look, Rupe, are you giving us the straight story on these UFO's?" I thought he meant that I was trying to spice things up a little, so I said that since he had copies of most of our reports and had read them, he should know that I was giving them the facts straight across the board. Then one of the other officers at the table cut in, "That's just the point, we do have the reports and we have read them. None of us can understand why Intelligence is so hesitant to accept the fact that something we just don't know about is flying around in our skies-- unless you are trying to cover up something big." Everyone at the table put in his ideas. One radar man said that he'd looked over several dozen radar reports and that his conclusion was that the UFO's couldn't be anything but interplanetary spaceships. He started to give his reasons when another radar man leaped into the conversation. This man said that he'd read every radar report, too, and that there wasn't one that couldn't be explained as a weather phenomenon--even the radar-visual sightings. In fact, he wasn't even convinced that we had ever gotten such a thing as radar-visual sighting. He wanted to see proof that an object that was seen visually was the same object that the radar had picked up. Did we have it? I got back into the discussion at this point with the answer. No, we didn't have proof if you want to get technical about the degree of proof needed. But we did have reports where the radar and visual bearings of the UFO coincided almost exactly. Then we had a few reports where airplanes had followed the UFO's and the maneuvers of the UFO that the pilot reported were the same as the maneuvers of the UFO that was being tracked by radar. A lieutenant colonel who had been sitting quietly by interjected a well-chosen comment. "It seems the difficulty that Project Blue Book faces is what to accept and what not to accept as proof." The colonel had hit the proverbial nail on its proverbial head. Then he went on, "Everyone has a different idea of what proof really is. Some people think we should accept a new model of an airplane after only five or ten hours of flight testing. This is enough proof for them that the airplane will fly. But others wouldn't be happy unless it was flight-tested for five or ten years. These people have set an unreasonably high value on the word 'proof.' The answer is somewhere in between these two extremes." But where is this point when it comes to UFO's? There was about a thirty-second pause for thought after the colonel's little speech. Then someone asked, "What about these recent sightings at Mainbrace?" In late September 1952 the NATO naval forces had held maneuvers off the coast of Europe; they were called Operation Mainbrace. Before they had started someone in the Pentagon had half seriously mentioned that Naval Intelligence should keep an eye open for UFO's, but no one really expected the UFO's to show up. Nevertheless, once again the UFO's were their old unpredictable selves--they were there. On September 20, a U.S. newspaper reporter aboard an aircraft carrier in the North Sea was photographing a carrier take-off in color when he happened to look back down the flight deck and saw a group of pilots and flight deck crew watching something in the sky. He went back to look and there was a silver sphere moving across the sky just behind the fleet of ships. The object appeared to be large, plenty large enough to show up in a photo, so the reporter shot several pictures. They were developed right away and turned out to be excellent. He had gotten the superstructure of the carrier in each one and, judging by the size of the object in each successive photo, one could see that it was moving rapidly. The intelligence officers aboard the carrier studied the photos. The object looked like a balloon. From its size it was apparent that if it were a balloon, it would have been launched from one of the ships, so the word went out on the TBS radio: "Who launched a balloon?" The answer came back on the TBS: "Nobody." Naval Intelligence double-checked, triple-checked and quadruple- checked every ship near the carrier but they could find no one who had launched the UFO. We kept after the Navy. The pilots and the flight deck crew who saw the UFO had mixed feelings--some were sure that the UFO was a balloon while others were just as sure that it couldn't have been. It was traveling too fast, and although it resembled a balloon in some ways it was far from being identical to the hundreds of balloons that the crew had seen the aerologists launch. We probably wouldn't have tried so hard to get a definite answer to the Mainbrace photos if it hadn't been for the events that took place during the rest of the operation, I explained to the group of ADC officers. The day after the photos had been taken six RAF pilots flying a formation of jet fighters over the North Sea saw something coming from the direction of the Mainbrace fleet. It was a shiny, spherical object, and they couldn't recognize it as anything "friendly" so they took after it. But in a minute or two they lost it. When they neared their base, one of the pilots looked back and saw that the UFO was now following him. He turned but the UFO also turned, and again it outdistanced the Meteor in a matter of minutes. Then on the third consecutive day a UFO showed up near the fleet, this time over Topcliffe Aerodrome in England. A pilot in a Meteor was scrambled and managed to get his jet fairly close to the UFO, close enough to see that the object was "round, silvery, and white" and seemed to "rotate around its vertical axis and sort of wobble." But before he could close in to get a really good look it was gone. It was these sightings, I was told by an RAF exchange intelligence officer in the Pentagon, that caused the RAF to officially recognize the UFO. By the time I'd finished telling about the Mainbrace Sightings, it was after the lunch hour in the club and we were getting some get-the- hell-out-of-here looks from the waiters, who wanted to clean up the dining room. But before I could suggest that we leave, Major Sadowski repeated his original question--the one that started the whole discussion--"Are you holding out on us?" I gave him an unqualified "No." We wanted more positive proof, and until we had it, UFO's would remain unidentified flying objects and no more. The horizontal shaking of heads illustrated some of the group's thinking. We had plans for getting more positive proof, however, and I said that just as soon as we returned to Major Sadowski's office I'd tell them what we contemplated doing. We moved out onto the sidewalk in front of the club and, after discussing a few more sightings, went back into the security area to Sadowski's office and I laid out our plans. First of all, in November or December the U.S. was going to shoot the first H-bomb during Project Ivy. Although this was Top Secret at the time, it was about the most poorly kept secret in history-- everybody seemed to know all about it. Some people in the Pentagon had the idea that there were beings, earthly or otherwise, who might be interested in our activities in the Pacific, as they seemed to be in Operation Mainbrace. Consequently Project Blue Book had been directed to get transportation to the test area to set up a reporting net, brief people on how to report, and analyze their reports on the spot. Secondly, Project Blue Book was working on plans for an extensive system to track UFO's by instruments. Brigadier General Garland, who had been General Samford's Deputy Director for Production and who had been riding herd on the UFO project for General Samford, was now chief at ATIC, having replaced Colonel Dunn, who went to the Air War College. General Garland had long been in favor of trying to get some concrete information, either positive or negative, about the UFO's. This planned tracking system would replace the defraction grid cameras that were still being developed at ATIC. Thirdly, as soon as we could we were planning to gather together a group of scientists and let them spend a full week or two studying the UFO problem. When I left ADC, Major Sadowski and crew were satisfied that we weren't just sitting around twiddling our UFO reports. During the fall of 1952 reports continued to drop off steadily. By December we were down to the normal average of thirty per month, with about 20 per cent of these falling into the "Unknown" category. Our proposed trip to the Pacific to watch for UFO's during the H- bomb test was canceled at the last minute because we couldn't get space on an airplane. But the crews of Navy and Air Force security forces who did go out to the tests were thoroughly briefed to look for UFO's, and they were given the procedures on how to track and report them. Back at Dayton we stood by to make quick analysis of any reports that might come in--none came. Nothing that fell into the UFO category was seen during the entire Project Ivy series of atomic shots. By December work on the planning phase of our instrumentation program was completed. During the two months we had been working on it we had considered everything from giving Ground Observer Corps spotters simple wooden tracking devices to building special radars and cameras. We had talked over our problems with the people at Wright Field who knew about missile-tracking equipment, and we had consulted the camera technicians at the Air Force Aerial Reconnaissance Laboratory. Astronomers explained their equipment and the techniques to use, and we went to Rome, New York, and Boston to enlist the aid of the people who develop the Air Force's electronic equipment. Our final plan called for visual spotting stations to be established all over northern New Mexico. We'd picked this test location because northern New Mexico still consistently produced more reports than any other area in the U.S. These visual spotting stations would be equipped with a sighting device similar to a gun sight on a bomber. All the operator would have to do would be to follow the UFO with the tracking device, and the exact time and the UFO's azimuth and elevation angles would be automatically recorded. The visual spotting stations would all be tied together with an interphone system, so that as soon as the tracker at one station saw something he could alert the other spotters in the area. If two stations tracked the same object, we could immediately compute its speed and altitude. This visual spotting net would be tied into the existing radar defense net in the Albuquerque-Los Alamos area. At each radar site we proposed that a long focal-length camera be synchronized to the turning radar antenna, so that any time the operator saw a target he could press a button and photograph the portion of the sky exactly where the radar said a UFO was located. These cameras would actually be astronomical telescopes, so that even the smallest light or object could be photographed. In addition to this photography system we proposed that a number of sets of instruments be set out around the area. Each set would contain instruments to measure nuclear radiation, any disturbances in the earth's magnetic field, and the passage of a body that was giving off heat. The instruments would continually be sending their information to a central "UFO command post," which would also get reports directly from the radars and the visual spotting stations. This instrumentation plan would cost about $250,000 because we planned to use as much surplus equipment as possible and tie it into existing communications systems, where they already existed. After the setup was established, it would cost about $25,000 a year to operate. At first glance this seemed like a lot of money, but when we figured out how much the UFO project had cost the Air Force in the past and how much it would probably cost in the future, the price didn't seem too bad--especially if we could solve the UFO problem once and for all. The powers-that-be at ATIC O.K.'d the plan in December and it went to Washington, where it would have to be approved by General Samford before it went to ADC and then back to the Pentagon for higher Air Force official blessing. From all indications it looked as if we would get the necessary blessings. But the majority of the effort at Project Blue Book during the fall of 1952 had gone toward collecting together all of the bits and pieces of data that we had accumulated over the past year and a half. We had sorted out the best of the "Unknowns" and made studies of certain aspects of the UFO problem, so that when we could assemble a panel of scientists to review the data we could give them the over- all picture, not just a basketful of parts. Everyone who knew about the proposed panel meeting was eager to get started because everyone was interested in knowing what this panel would have to say. Although the group of scientists wouldn't be empowered to make the final decision, their recommendations were to go to the President if they decided that the UFO's were real. And any recommendations made by the group of names we planned to assemble would carry a lot of weight. In the Pentagon and at ATIC book was being made on what their recommendations would be. When I put my money down, the odds were 5 to 3 in favor of the UFO. CHAPTER FIFTEEN The Radiation Story The idea for gathering together a group of scientists, to whom we referred as our "panel of experts," had been conceived early in 1952-- as soon as serious talk about the possibility that the UFO's might be interplanetary spaceships had taken hold in both military and scientific circles. In fact, when Project Grudge was reorganized in the summer of 1951 the idea had been mentioned, and this was the main reason that our charter had said we were to be only a fact-finding group. The people on previous UFO projects had gone off on tangents of speculation about the identity of the UFO's; they first declared that they were spacecraft, then later, in a complete about-face, they took the whole UFO problem as one big belly laugh. Both approaches had gotten the Air Force into trouble. Why they did this I don't know, because from the start we realized that no one at ATIC, in the Air Force, or in the whole military establishment was qualified to give a final yes or no answer to the UFO problem. Giving a final answer would require a serious decision--probably one of the most serious since the beginning of man. During 1952 many highly qualified engineers and scientists had visited Project Blue Book and had spent a day or two going over our reports. Some were very much impressed with the reports--some had all the answers. But all of the scientists who read our reports readily admitted that even though they may have thought that the reports did or did not indicate visitors from outer space, they would want to give the subject a good deal more study before they ever committed themselves in writing. Consequently the people's opinions, although they were valuable, didn't give us enough to base a decision upon. We still needed a group to study our material thoroughly and give us written conclusions and recommendations which could be sent to the President if necessary. Our panel of experts was to consist of six or eight of the top scientists in the United States. We fully realized that even the Air Force didn't have enough "pull" just to ask all of these people to drop the important work they were engaged in and spend a week or two studying our reports. Nor did we want to do it this way; we wanted to be sure that we had something worth while before asking for their valuable time. So, working through other government agencies, we organized a preliminary review panel of four people. All of them were competent scientists and we knew their reputations were such that if they recommended that a certain top scientist sit on a panel to review our material he would do it. In late November 1952 the preliminary review panel met at ATIC for three days. When the meeting ended, the group unanimously recommended that a "higher court" be formed to review the case of the UFO. In an hour their recommendation was accepted by higher Air Force authorities, and the men proceeded to recommend the members for our proposed panel. They picked six men who had reputations as being both practical and theoretical scientists and who were known to have no biased opinions regarding the UFO's. The meeting of the panel, which would be held in Washington, was tentatively scheduled for late December or early January--depending upon when all of the scientists who had been asked to attend would be free. At Project Blue Book activity went into high gear as we made preparations for the meeting. But before we were very far along our preparations were temporarily sidetracked--I got a lead on the facts behind a rumor. Normally we didn't pay attention to rumors, but this one was in a different class. Ever since the Air Force had become interested in UFO reports, the comment of those who had been requested to look them over and give a professional opinion was that we lacked the type of data "you could get your teeth into." In even our best reports we had to rely upon what someone had seen. I'd been told many times that if we had even one piece of information that was substantiated by some kind of recorded proof--a set of cinetheodolite movies of a UFO, a spectrum photograph, or any other kind of instrumented data that one could sit down and study--we would have no difficulty getting almost any scientist in the world interested in actively helping us find the answer to the UFO riddle. The rumor that caused me to temporarily halt our preparations for the high-level conference involved data that we might be able to get our teeth into. This is the way it went. In the fall of 1949, at some unspecified place in the United States, a group of scientists had set up equipment to measure background radiation, the small amount of harmless radiation that is always present in our atmosphere. This natural radiation varies to a certain degree, but will never increase by any appreciable amount unless there is a good reason. According to the rumor, two of the scientists at the unnamed place were watching the equipment one day when, for no apparent reason, a sudden increase of radiation was indicated. The radiation remained high for a few seconds, then dropped back to normal. The increase over normal was not sufficient to be dangerous, but it definitely was unusual. All indications pointed to equipment malfunction as the most probable explanation. A quick check revealed no obvious trouble with the gear, and the two scientists were about to start a more detailed check when a third member of the radiation crew came rushing into the lab. Before they could tell the newcomer about the unexplained radiation they had just picked up, he blurted out a story of his own. He had driven to a nearby town, and on his return trip, as he approached the research lab, something in the sky suddenly caught his eye. High in the cloudless blue he saw three silvery objects moving in a V formation. They appeared to be spherical in shape, but he wasn't sure. The first fact that had hit him was that the objects were traveling too fast to be conventional aircraft. He jammed on the brakes, stopped his car, and shut off the engine. No sound. All he could hear was the quiet whir of a generator in the research lab. In a few seconds the objects had disappeared from sight. After the first two scientists had briefed their excited colleague on the unusual radiation they had detected, the three men asked each other the $64 question: Was there any connection between the two incidents? Had the UFO's caused the excessive radiation? They checked the time. Knowing almost exactly when the instruments had registered the increased radiation, they checked on how long it took to drive to the lab from the point where the three silver objects had been seen. The times correlated within a minute or two. The three men proceeded to check their radiation equipment thoroughly. Nothing was wrong. The rumor stopped here. Nothing that I or anyone else on Project Blue Book could find out shed any further light on the source of the story. People associated with projects similar to the research lab that was mentioned in the rumor were sought out and questioned. Many of them had heard the story, but no one could add any new details. The three unknown scientists, at the unnamed lab, in an unknown part of the United States, might as well never have existed. Maybe they hadn't. Almost a year after I had first heard the UFO-radiation story I got a long-distance call from a friend on the west coast. I had seen him several months before, at which time I told him about this curious rumor and expressed my wish to find out how authentic it was. Now, on the phone, he told me he had just been in contact with two people he knew and they had the whole story. He said they would be in Los Angeles the following night and would like very much to talk to me. I hated to fly clear to the west coast on what might be a wild-goose chase, but I did. I couldn't afford to run the risk of losing an opportunity to turn that old recurrent rumor into fact. Twenty hours later I met the two people at the Hollywood Roosevelt Hotel. We talked for several hours that night, and I got the details on the rumor and a lot more that I hadn't bargained for. Both of my informants were physicists working for the Atomic Energy Commission, and were recognized in their fields. They wanted no publicity and I promised them that they would get none. One of the men knew all the details behind the rumor, and did most of the talking. To keep my promise of no publicity, I'll call him the "scientist." The rumor version of the UFO-radiation story that had been kicking around in Air Force and scientific circles for so long had been correct in detail but it was by no means complete. The scientist said that after the initial sighting had taken place word was spread at the research lab that the next time the instruments registered abnormal amounts of radiation, some of the personnel were to go outside immediately and look for some object in the sky. About three weeks after the first incident a repetition did occur. While excessive radiation was registering on the instruments in the lab, a lone dark object was seen streaking across the sky. Again the instruments were checked but, as before, no malfunction was found. After this second sighting, according to the scientist, an investigation was started at the laboratory. The people who made the visual observations weren't sure that the object they had seen couldn't have been an airplane. Someone thought that perhaps some type of radar equipment in the airplane, if that's what the object was, might have affected the radiation-detection equipment. So arrangements were made to fly all types of aircraft over the area with their radar in operation. Nothing unusual happened. All possible types of airborne research equipment were traced during similar flights in the hope that some special equipment not normally carried in aircraft would be found to have caused the jump in radiation. But nothing out of the ordinary occurred during these tests either. It was tentatively concluded, the scientist continued, that the abnormally high radiation readings were "officially" due to some freakish equipment malfunction and that the objects sighted visually were birds or airplanes. A report to this effect was made to military authorities, but since the conclusion stated that no flying saucers were involved, the report went into some unknown file. Project Blue Book never got it. Shortly after the second UFO-radiation episode the research group finished its work. It was at this time that the scientist had first become aware of the incidents he related to me. A friend of his, one of the men involved in the sightings, had sent the details in a letter. As the story of the sightings spread it was widely discussed in scientific circles, with the result that the conclusion, an equipment malfunction, began to be more seriously questioned. Among the scientists who felt that further investigation of such phenomena was in order, were the man to whom I was talking and some of the people who had made the original sightings. About a year later the scientist and these original investigators were working together. They decided to make a few more tests, on their own time, but with radiation-detection equipment so designed that the possibility of malfunction would be almost nil. They formed a group of people who were interested in the project, and on evenings and weekends assembled and set up their equipment in an abandoned building on a small mountain peak. To insure privacy and to avoid arousing undue interest among people not in on the project, the scientist and his colleagues told everyone that they had formed a mineral club. The "mineral club" deception covered their weekend expeditions because "rock hounds" are notorious for their addiction to scrambling around on mountains in search for specimens. The equipment that the group had installed in the abandoned building was designed to be self-operating. Geiger tubes were arranged in a pattern so that some idea as to the direction of the radiation source could be obtained. During the original sightings the equipment- malfunction factor could not be definitely established or refuted because certain critical data had not been measured. To get data on visual sightings, the "mineral club" had to rely on the flying saucer grapevine, which exists at every major scientific laboratory in the country. By late summer of 1950 they were in business. For the next three months the scientist and his group kept their radiation equipment operating twenty-four hours a day, but the tapes showed nothing except the usual background activity. The saucer grapevine reported sightings in the general area of the tests, but none close to the instrumented mountaintop. The trip to the instrument shack, which had to be made every two days to change tapes, began to get tiresome for the "rock hounds," and there was some talk of discontinuing the watch. But persistence paid off. Early in December, about ten o'clock in the morning, the grapevine reported sightings of a silvery, circular- shaped object near the instrument shack. The UFO was seen by several people. When the "rock hounds" checked the recording tapes in the shack they found that several of the Geiger tubes had been triggered at 10:17A.M. The registered radiation increase was about 100 times greater than the normal background activity. Three more times during the next two months the "mineral club's" equipment recorded abnormal radiation on occasions when the grapevine reported visual sightings of UFO's. One of the visual sightings was substantiated by radar. After these incidents the "mineral club" kept its instruments in operation until June 1951, but nothing more was recorded. And, curiously enough, during this period while the radiation level remained normal, the visual sightings in the area dropped off too. The "mineral club" decided to concentrate on determining the significance of the data they had obtained. Accordingly, the scientist and the group made a detailed study of their mountaintop findings. They had friends working on many research projects throughout the United States and managed to visit and confer with them while on business trips. They investigated the possibility of unusual sunspot activity, but sunspots had been normal during the brief periods of high radiation. To clinch the elimination of sunspots as a cause, their record tapes showed no burst of radiation when sunspot activity had been abnormal. The "rock hounds" checked every possible research project that might have produced some stray radiation for their instruments to pick up. They found nothing. They checked and rechecked their instruments, but could find no factor that might have induced false readings. They let other scientists in on their findings, hoping that these outsiders might be able to put their fingers on errors that had been overlooked. Now, more than a year after the occurrence of the mysterious incidents that they had recorded, a year spent in analyzing their data, the "rock hounds" had no answer. By the best scientific tests that they had been able to apply, the visual sightings and the high radiation had taken place more or less simultaneously. Intriguing ideas are hard to kill, and this one had more than one life, possibly because of the element of mystery which surrounds the subject of flying saucers. But the scientific mind thrives on taking the mystery out of unexplained events, so it is not surprising that the investigation went on. According to my friend the scientist, a few people outside the laboratory where the "rock hounds" worked were told about the activities of the "mineral club," and they started radiation- detection groups of their own. For instance, two graduate astronomy students from a southwestern university started a similar watch, on a modest scale, using a modified standard Geiger counter as their detection unit. They did not build a recorder into their equipment, however, and consequently were forced to man their equipment continuously, which naturally cut down the time they were in operation. On two occasions they reportedly detected a burst of high radiation. Although the veracity of the two astronomers was not doubted, the scientist felt that the accuracy of their readings was poor because of the rather low quality of their equipment. The scientist then told me about a far more impressive effort to verify or disprove the findings of the "mineral club." Word of the "rock hounds" and their work had also spread to a large laboratory in the East. An Air Force colonel, on duty at the lab, told the story to some of his friends, and they decided to look personally into the situation. Fortunately these people were in a wonderful spot to make such an investigation. At their laboratory an extensive survey of the surrounding area was being made. An elaborate system of radiation- detection equipment had been set up for a radius of 100 miles around the lab. In addition, the defenses of the area included a radar net. Thanks to the flashing of silver eagles, the colonel's group got permission to check the records of the radiation-survey station and to look over the logs of the radar stations. They found instances where, during the same period of time that radiation in the area had been much higher than normal, radar had had a UFO on the scope. These events had occurred during the period from January 1951 until about June 1951. Upon learning of the tentative but encouraging findings that the colonel's group had dug out of their past records, people on both the radiation-survey crews and at the radar sites became interested in co- operating for further investigation. A tie-in with the local saucer grapevine established a three-way check. One evening in July, just before sunset, two of the colonel's group were driving home from the laboratory. As they sped along the highway they noticed two cars stopped ahead of them. The occupants were standing beside the road, looking at something in the sky. The two scientists stopped, got out of their car, and scanned the sky too. Low on the eastern horizon they saw a bright circular object moving slowly north. They watched it for a while, took a few notes, then drove back to the lab. Some interesting news awaited them there. Radar had picked up an unidentified target near the spot where the scientists in the car had seen the UFO, and it had been traveling north. A fighter had been scrambled, but when it got into the proper area, the radar target was off the scope. The pilot glimpsed something that looked like the reported UFO, but before he could check further he had to turn into the sun to get on an interception course, and he lost the object. Several days passed before the radiation reports from all stations could be collected. When the reports did come in they showed that stations east of the laboratory, on an approximate line with the radar track, had shown the highest increase in radiation. Stations west of the lab showed nothing. The possible significance of this well-covered incident spurred the colonel's group to extend and refine their activities. Their idea was to build a radiation-detection instrument in an empty wing tank and hang the tank on an F-47. Then when a UFO was reported they would fly a search pattern in the area and try to establish whether or not a certain sector of the sky was more radioactive than other sectors. Also, they proposed to build a highly directional detector for the F- 47 and attempt actually to track a UFO. The design of such equipment was started, but many delays occurred. Before the colonel's group could get any of the equipment built, some of the members left the lab for other jobs, and the colonel, who sparked the operation, was himself transferred elsewhere. The entire effort collapsed. The scientist was not surprised that I hadn't heard the story of the colonel's group. All the people involved, he said, had kept it quiet in order to avoid ridicule. The scientist added that he would be glad to give me all the data he had on the sightings of his "mineral club," and he told me where to get the information about the two astronomers and the colonel's group. Armed with the scientist's notes and recorder tapes, I left for my office at Wright-Patterson Air Force Base, Dayton. With the blessings of my chief, I started to run down the rest of the radiation information. The data we had, especially that from the scientist's "mineral club," had been thoroughly analyzed, but we thought that since we now had access to more general data something new and more significant might be found. First I contacted the government agency for which all of the people involved in these investigations had been working, the scientists who recorded the original incident, the scientist and his "mineral club," the colonel's group, and the rest. The people in the agency were very co-operative but stressed the fact that the activities I was investigating were strictly the extracurricular affairs of the scientists involved, had no official sanction, and should not be tied in with the agency in any way, shape, or form. This closed-door reaction was typical of how the words "flying saucer" seem to scare some people. They did help me locate the report on the original incident, however, and since it seemed to be the only existing copy, I arranged to borrow it. About this same time we located the two graduate astronomy students in New Mexico. Both now had their Ph.D.'s and held responsible jobs on highly classified projects. They repeated their story, which I had first heard from the scientist, but had kept no record of their activities. On one occasion, just before dawn on a Sunday morning, they were on the roof, making some meteorological observations. One of them was listening to the Geiger counter when he detected a definite increase in the clicking. Just as the frequency of the clicks reached its highest peak--almost a steady buzz--a large fireball, described by them as "spectacular," flashed across the sky. Both of the observers had seen several of the green fireballs and said that this object was similar in all respects except that the color was a brilliant blue-white. With the disappearance of the fireball, the counter once more settled down to a steady click per second. They added that once before they had detected a similar increase in the frequency of the clicks but had seen nothing in the sky. In telling their story, both astronomers stressed the point that their data were open to a great deal of criticism, mainly because of the limited instrumentation they had used. We agreed. Still their work tended to support the findings of the more elaborate and systematic radiation investigations. The gods who watch over the UFO project were smiling about this time, because one morning I got a call from a colonel on Wright- Patterson Air Force Base. He was going to be in our area that morning and planned to stop in to see me. He arrived in a few minutes and turned out to be none other than the colonel who had headed the group which had investigated UFO's and radiation at the eastern laboratory. He repeated his story. It was the same as I had heard from the scientist, with a few insignificant changes. The colonel had no records of his group's operations, but knew who had them. He promised to get a wire off to the person immediately, which he did. The answer was a bit disappointing. During the intervening months the data had been scattered out among the members of the colonel's group, and when the group broke up, so did its collection of records. So all we had to fall back on was the colonel's word, but since he now was heading a top-priority project at Wright, it would be difficult not to believe him. After obtaining the colonel's story, we collected all available data concerning known incidents in which there seemed to be a correlation between the visual sighting of UFO's and the presence of excess atomic radiation in the area of the sightings. There was one last thing to do. I wanted to take the dates and times of all the reported radiation increases and check them against all sources of UFO reports. This project would take a lot of leg work and digging, but I felt that it would offer the most positive and complete evidence we could assemble as to whether or not a correlation existed. Accordingly, we dug into our files, ADC radar logs, press wire service files, newspaper morgues in the sighting area, and the files of individuals who collect data on saucers. Whenever we found a visual report that correlated with a radiation peak we checked it against weather conditions, balloon tracks, astronomical reports, etc. As soon as the data had all been assembled, I arranged for a group of Air Force consultants to look it over. I got the same old answer-- the data still aren't good enough. The men were very much interested in the reports, but when it came time to putting their comments on paper they said, "Not enough conclusive evidence." If in some way the UFO's could have been photographed at the same time that the radiation detectors were going wild, it would have been a different story, they later told me, but with the data I had for them this was the only answer they could give. No one could explain the sudden bursts of radiation, but there was no proof that they were associated with UFO's. The board's ruling wrote finish to this investigation. I informed the colonel, and he didn't like the decision. Later I passed through the city where the scientist was working. I stopped over a few hours to brief him on the board's decision. He shook his head in disbelief. It is interesting to note that both the colonel and the scientist reacted in the same way. We're not fools--we were there--we saw it-- they didn't. What do they want for proof? CHAPTER SIXTEEN The Hierarchy Ponders By early January 1953 the scientists who were to be members of our panel of experts had been contacted and had agreed to sit in judgment of the UFO. In turn, we agreed to give them every detail about the UFO. We had our best reports for them to read, and we were going to show them the two movies that some intelligence officers considered as the "positive proof"--the Tremonton Movie and the Montana Movie. When this high court convened on the morning of January 12, the first thing it received was its orders; one of three verdicts would be acceptable: All UFO reports are explainable as known objects or natural phenomena; therefore the investigation should be permanently discontinued. The UFO reports do not contain enough data upon which to base a final conclusion. Project Blue Book should be continued in hopes of obtaining better data. The UFO's are interplanetary spacecraft. The written verdict, the group was told, would be given to the National Security Council, a council made up of the directors of all U.S. intelligence agencies, and thence it would go to the President of the United States--if they should decide that the UFO's were interplanetary spacecraft. Because of military regulations, the names of the panel members, like the names of so many other people associated with the UFO story, cannot be revealed. Two of the men had made names for themselves as practical physicists--they could transform the highest theory for practical uses. One of these men had developed the radar that pulled us out of a big hole at the beginning of World War II, and the other had been one of the fathers of the H-bomb. Another of the panel members is now the chief civilian adviser to one of our top military commanders, and another was an astronomer whose unpublished fight to get the UFO recognized is respected throughout scientific circles. There was a man who is noted for his highly theoretical physics and mathematics, and another who had pioneered operations research during World War II. The sixth member of the panel had been honored by the American Rocket Society and the International Astronautical Federation for his work in moving space travel from the Buck Rogers realm to the point of near reality and who is now a rocket expert. It was an impressive collection of top scientific talent. During the first two days of the meeting I reviewed our findings for the scientists. Since June 1947, when the first UFO report had been made, ATIC had analyzed 1,593 UFO reports. About 4,400 had actually been received, but all except 1,593 had been immediately rejected for analysis. From our studies, we estimated that ATIC received reports of only 10 per cent of the UFO sightings that were made in the United States, therefore in five and a half years something like 44,000 UFO sightings had been made. Of the 1,593 reports that had been analyzed by Project Blue Book, and we had studied and evaluated every report in the Air Force files, we had been able to explain a great many. The actual breakdown was like this: _Balloons_.....................18.51% Known 1.57 Probable 4.99 Possible 11.95 18.51 _Aircraft_.....................11.76% Known 0.98 Probable 7.74 Possible 3.04 11.76 _Astronomical_ _Bodies_........14.20% Known 2.79 Probable 4.01 Possible 7.40 14.20 _Other_ ........................4.21% Searchlights on clouds, birds, blowing paper, inversions, reflections, etc. _Hoaxes_........................1.66% _Insufficient_ _data_..........22.72% (In addition to those initially eliminated) _Unknowns_.....................26.94% By using the terms "Known," "Probable," and "Possible," we were able to differentiate how positive we were of our conclusions. But even in the "Possible" cases we were, in our own minds, sure that we had identified the reported UFO. And who made these reports? Pilots and air crews made 17.1 per cent from the air. Scientists and engineers made 5.7 per cent, airport control tower operators made an even 1.0 per cent of the reports, and 12.5 per cent of the total were radar reports. The remaining 63.7 per cent were made by military and civilian observers in general. The reports that we were interested in were the 26.94 per cent or 429 "Unknowns," so we had studied them in great detail. We studied the reported colors of the UFO's, the shapes, the directions they were traveling, the times of day they were observed, and many more details, but we could find no significant pattern or trends. We did find that the most often reported shape was elliptical and that the most often reported color was white or "metallic." About the same number of UFO's were reported as being seen in daytime as at night, and the direction of travel equally covered the sixteen cardinal headings of the compass. Seventy per cent of the "Unknowns" had been seen visually from the air; 12 per cent had been seen visually from the ground; 10 per cent had been picked up by ground or airborne radar; and 8 per cent were combination visual-radar sightings. In the over-all total of 1,593 sightings women made two reports for every one made by a man, but in the "Unknowns" the men beat out women ten to one. There were two other factors we could never resolve, the frequency of the sightings and their geographical distribution. Since the first flurry of reports in July of 1947, each July brought a definite peak in reports; then a definite secondary peak occurred just before each Christmas. We plotted these peaks in sightings against high tides, world-wide atomic tests, the positions of the moon and planets, the general cloudiness over the United States, and a dozen and one other things, but we could never say what caused more people to see UFO's at certain times of the year. Then the UFO's were habitually reported from areas around "technically interesting" places like our atomic energy installations, harbors, and critical manufacturing areas. Our studies showed that such vital military areas as Strategic Air Command and Air Defense Command bases, some A-bomb storage areas, and large military depots actually produced fewer reports than could be expected from a given area in the United States. Large population centers devoid of any major "technically interesting" facilities also produced few reports. According to the laws of normal distribution, if UFO's are not intelligently controlled vehicles, the distribution of reports should have been similar to the distribution of population in the United States--it wasn't. Our study of the geographical locations of sightings also covered other countries. The U.S. by no means had a curb on the UFO market. In all of our "Unknown" reports we never found one measurement of size, speed, or altitude that could be considered to be even fairly accurate. We could say only that some of the UFO's had been traveling pretty fast. As far as radar was concerned, we had reports of fantastic speeds-- up to 50,000 miles an hour--but in all of these instances there was some doubt as to exactly what caused the target. The highest speeds reported for our combination radar-visual sightings, which we considered to be the best type of sighting in our files, were 700 to 800 miles an hour. We had never picked up any "hardware"--any whole saucers, pieces, or parts--that couldn't be readily identified as being something very earthly. We had a contract with a materials-testing laboratory, and they would analyze any piece of material that we found or was sent to us. The tar-covered marble, aluminum broom handle, cow manure, slag, pieces of plastic balloon, and the what-have-you that we did receive and analyze only served to give the people in our material lab some practice and added nothing but laughs to the UFO project. The same went for the reports of "contacts" with spacemen. Since 1952 a dozen or so people have claimed that they have talked to or ridden with the crews of flying saucers. They offer affidavits, pieces of material, photographs, and other bits and pieces of junk as proof. We investigated some of these reports and could find absolutely no fact behind the stories. We had a hundred or so photos of flying saucers, both stills and movies. Many were fakes--some so expert that it took careful study by photo interpreters to show how the photos had been faked. Some were the crudest of fakes, automobile hub caps thrown into the air, homemade saucers suspended by threads, and just plain retouched negatives. The rest of the still photos had been sent in by well- meaning citizens who couldn't recognize a light flare of flaw in the negative, or who had chanced to get an excellent photo of a sundog or mirage. But the movies that were sent in to us were different. In the first place, it takes an expert with elaborate equipment to fake a movie. We had or knew about four strips of movie film that fell into the "Unknown" category. Two were the cinetheodolite movies that had been taken at White Sands Proving Ground in April and May of 1950, one was the Montana Movie and the last was the Tremonton Movie. These latter two had been subjected to thousands of hours of analysis, and since we planned to give the panel of scientists more thorough reports on them on Friday, I skipped over their details and went to the next point I wanted to cover--theories. Periodically throughout the history of the UFO people have come up with widely publicized theories to explain all UFO reports. The one that received the most publicity was the one offered by Dr. Donald Menzel of Harvard University. Dr. Menzel, writing in _Time_, _Look_, and later in his _Flying_ _Saucers_, claimed that all UFO reports could be explained as various types of light phenomena. We studied this theory thoroughly because it did seem to have merit. Project Bear's physicists studied it. ATIC's scientific consultants studied it and discussed it with several leading European physicists whose specialty was atmospheric physics. In general the comments that Project Blue Book received were, "He's given the subject some thought but his explanations are not the panacea." And there were other widely publicized theories. One man said that they were all skyhook balloons, but we knew the flight path of every skyhook balloon and they were seldom reported as UFO's. Their little brothers, the weather balloons, caused us a great deal more trouble. The Army Engineers took a crack at solving the UFO problem by making an announcement that a scientist in one of their laboratories had duplicated a flying saucer in his laboratory. Major Dewey Fournet checked into this one. It had all started out as a joke, but it was picked up as fact and the scientist was stuck with it. He gained some publicity but lost prestige because other scientists wondered just how competent the man really was to try to pass off such an answer. All in all, the unsolicited assistance of theorists didn't help us a bit, I told the panel members. Some of them were evidently familiar with the theories because they nodded their heads in agreement. The next topic I covered in my briefing was a question that came up quite frequently in discussions of the UFO: Did UFO reports actually start in 1947? We had spent a great deal of time trying to resolve this question. Old newspaper files, journals, and books that we found in the Library of Congress contained many reports of odd things being seen in the sky as far back as the Biblical times. The old Negro spiritual says, "Ezekiel saw a wheel 'way up in the middle of the air." We couldn't substantiate Ezekiel's sighting because many of the very old reports of odd things observed in the sky could be explained as natural phenomena that weren't fully understood in those days. The first documented reports of sightings similar to the UFO sightings as we know them today appeared in the newspapers of 1896. In fact, the series of sightings that occurred in that year and the next had many points of similarity with the reports of today. The sightings started in the San Francisco Bay area on the evening of November 22, 1896, when hundreds of people going home from work saw a large, dark, "cigar-shaped object with stubby wings" traveling northwest across Oakland. Within hours after the mystery craft had disappeared over what is now the northern end of the Golden Gate Bridge, the stories of people in other northern California towns began to come in on the telegraph wires. The citizens of Santa Rosa, Sacramento, Chico, and Red Bluff-- several thousand of them--saw it. I tried to find out if the people in these outlying communities saw the UFO before they heard the news from the San Francisco area or afterward, but trying to run down the details of a fifty-six-year-old UFO report is almost hopeless. Once while I was on a trip to Hamilton AFB I called the offices of the San Francisco _Chronicle_ and they put me in touch with a retired employee who had worked on a San Francisco paper in 1896. I called the old gentleman on the phone and talked to him for a long time. He had been a copy boy at the time and remembered the incident, but time had canceled out the details. He did tell me that he, the editor of the paper, and the news staff had seen "the ship," as he referred to the UFO. His story, even though it was fifty-six years old, smacked of others I'd heard when he said that no one at the newspaper ever told anyone what they had seen; they didn't want people to think that they were "crazy." On November 30 the mystery ship was back over the San Francisco area and those people who had maintained that people were being fooled by a wag in a balloon became believers when the object was seen moving into the wind. For four months reports came in from villages, cities, and farms in the West; then the Midwest, as the airship "moved eastward." In early April of 1897 people in Iowa, Nebraska, Missouri, Wisconsin, Minnesota, and Illinois reported seeing it. On April 10 it was reported to be over Chicago. Reports continued to come in to the newspapers until about April 20; then it, or stories about it, were gone. Literally thousands of people had seen it before the last report clicked in over the telegraph wires. A study of the hundreds of newspaper accounts of this sighting that rocked the world in the late 1890's was interesting because the same controversies that arose then exist now. Those who hadn't seen the stubby-winged, cigar-shaped "craft" said, "Phooey," or the nineteenth- century version thereof. Those who had seen it were almost ready to do battle to uphold their integrity. Some astronomers loudly yelled, "Venus," "Jupiter," and "Alpha Orionis" while others said, "We saw it." Thomas Edison, _the_ man of science of the day, disclaimed any knowledge of the mystery craft. "I prefer to devote my time to objects of commercial value," he told a New York _Herald_ reporter. "At best airships would only be toys." Thomas--you goofed on that prediction. I had one more important point to cover before I finished my briefing and opened the meeting to a general question-and-answer session. During the past year and a half we had had several astronomers visit Project Blue Book, and they were not at all hesitant to give us their opinions but they didn't care to say much about what their colleagues were thinking, although they did indicate that they were thinking. We decided that the opinions and comments of astronomers would be of value, so late in 1952 we took a poll. We asked an astronomer, whom we knew to be unbiased about the UFO problem and who knew every outstanding astronomer in the United States, to take a trip and talk to his friends. We asked him not to make a point of asking about the UFO but just to work the subject into a friendly conversation. This way we hoped to get a completely frank opinion. To protect his fellow astronomers, our astronomer gave them all code names and he kept the key to the code. The report we received expressed the detailed opinions of forty-five recognized authorities. Their opinions varied from that of Dr. C, who regarded the UFO project as a "silly waste of money to investigate an even sillier subject," to Dr. L, who has spent a great deal of his own valuable time personally investigating UFO reports because he believes that they are something "real." Of the forty-five astronomers who were interviewed, 36 per cent were not at all interested in the UFO reports, 41 per cent were interested to the point of offering their services if they were ever needed, and 23 per cent thought that the UFO's were a much more serious problem than most people recognized. None of the astronomers, even during a friendly discussion, admitted that he thought the UFO's could be interplanetary vehicles. All of those who were interested would only go so far as to say, "We don't know what they are, but they're something real." During the past few years I have heard it said that if the UFO's were really "solid objects" our astronomers would have seen them. Our study shed some light on this point--astronomers have seen UFO's. None of them has ever seen or photographed anything resembling a UFO through his telescope, but 11 per cent of the forty-five men had seen something that they couldn't explain. Although, technically speaking, these sightings were no better than hundreds of others in our files as far as details were concerned, they were good because of the caliber of the observer. Astronomers know what is in the sky. It is interesting to note that out of the representative cross section of astronomers, five of them, or 11 per cent, had sighted UFO's. For a given group of people this is well above average. To check this point, the astronomer who was making our study picked ninety people at random--people he met while traveling--and got them into a conversation about flying saucers. These people were his "control group," to borrow a term from the psychologists. Although the percentage of people who were interested in UFO's was higher for the control group than for the group of astronomers, only 41 per cent of the astronomers were interested while 86 per cent of the control group were interested; 11 per cent of the astronomers had seen UFO's, while only about 1 per cent of the control group had seen one. This seemed to indicate that as a group astronomers see many more UFO's than the average citizen. When I finished my briefing, it was too late to start the question- and-answer session, so the first day's meeting adjourned. But promptly at nine o'clock the next morning the group was again gathered, and from the looks of the list of questions some of them had, they must have been thinking about UFO's all night. One of the first questions was about the results of photography taken by the pairs of huge "meteorite patrol" cameras that are located in several places throughout North America. Did they ever photograph a UFO? The cameras, which are in operation almost every clear night, can photograph very dim lights, and once a light is photographed its speed and altitude can be very accurately established. If there were any objects giving off light as they flew through our atmosphere, there is a chance that these cameras might have photographed them. But they hadn't. At first this seemed to be an important piece of evidence and we had just about racked this fact up as a definite score against the UFO when we did a little checking. If the UFO had been flying at an altitude of 100 miles, the chances of its being picked up by the cameras would be good, but the chances of photographing something flying any lower would be less. This may account for the fact that while our "inquiring astronomer" was at the meteorite patrol camera sites, he talked to an astronomer who had seen a UFO while operating one of the patrol cameras. Many people have asked why our astronomers haven't seen anything through their big telescopes. They are focused light-years away and their field of vision is so narrow that even if UFO's did exist and littered the atmosphere they wouldn't be seen. Another question the panel had was about Orson Welles' famous _War_ _of_ _the_ _Worlds_ broadcast of October 1938, which caused thousands of people to panic. Had we studied this to see if there were any similarities between it and the current UFO reporting? We had. Our psychologist looked into the matter and gave us an opinion--to make a complete study and get a positive answer would require an effort that would dwarf the entire UFO project. But he did have a few comments. There were many documented cases in which a series of innocent circumstances triggered by the broadcast had caused people to completely lose all sense of good judgment--to panic. There were some similar reports in our UFO files. But we had many reports in which people reported UFO's and obviously hadn't panicked. Reports from pilots who had seen mysterious lights at night and, thinking that they might be a cockpit reflection, had turned off all their cockpit lights. Or the pilots who turned and rolled their airplanes to see if they could change the angle of reflection and get rid of the UFO. Or those pilots who climbed and dove thousands of feet and then leveled out to see if the UFO would change its relative position to the airplane. Or the amateur astronomer who made an excellent sighting and before he reluctantly reported it as a UFO had talked to a half dozen professional astronomers and physicists in hopes of finding an explanation. All of these people were thinking clearly, questioning themselves as to what the sightings could be; then trying to answer their questions. These people weren't panicked. The question-and-answer period went on for a full day as the scientists dug into the details of the general facts I had given them in my briefing. The following day and a half was devoted to reviewing and discussing fifty of our best sighting reports that we had classed as "Unknowns." The next item on the agenda, when the panel had finished absorbing all of the details of the fifty selected top reports, was a review of a very hot and very highly controversial study. It was based on the idea that Major Dewey Fournet and I had talked about several months before--an analysis of the motions of the reported UFO's in an attempt to determine whether they were intelligently controlled. The study was hot because it wasn't official and the reason it wasn't official was because it was so hot. It concluded that the UFO's were interplanetary spaceships. The report had circulated around high command levels of intelligence and it had been read with a good deal of interest. But even though some officers at command levels just a notch below General Samford bought it, the space behind the words "Approved by" was blank--no one would stick his neck out and officially send it to the top. Dewey Fournet, who had completed his tour of active duty in the Air Force and was now a civilian, was called from Houston, Texas, to tell the scientists about the study since he had worked very closely with the group that had prepared it. The study covered several hundred of our most detailed UFO reports. By a very critical process of elimination, based on the motion of the reported UFO's, Fournet told the panel how he and any previous analysis by Project Blue Book had been disregarded and how those reports that could have been caused by any one of the many dozen known objects--balloons, airplanes, astronomical bodies, etc., were sifted out. This sifting took quite a toll, and the study ended up with only ten or twenty reports that fell into the "Unknown" category. Since such critical methods of evaluation had been used, these few reports proved beyond a doubt that the UFO's were intelligently controlled by persons with brains equal to or far surpassing ours. The next step in the study, Fournet explained, was to find out where they came from. "Earthlings" were eliminated, leaving the final answer--spacemen. Both Dewey and I had been somewhat worried about how the panel would react to a study with such definite conclusions. But when he finished his presentation, it was obvious from the tone of the questioning that the men were giving the conclusions serious thought. Fournet's excellent reputation was well known. On Friday morning we presented the feature attractions of the session, the Tremonton Movie and the Montana Movie. These two bits of evidence represented the best photos of UFO's that Project Blue Book had to offer. The scientists knew about them, especially the Tremonton Movie, because since late July they had been the subject of many closed-door conferences. Generals, admirals, and GS-16's had seen them at "command performances," and they had been flown to Kelly AFB in Texas to be shown to a conference of intelligence officers from all over the world. Two of the country's best military photo laboratories, the Air Force lab at Wright Field and the Navy's lab at Anacostia, Maryland, had spent many hours trying to prove that the UFO's were balloons, airplanes, or stray light reflections, but they failed--the UFO's were true unknowns. The possibility that the movie had been faked was considered but quickly rejected because only a Hollywood studio with elaborate equipment could do such a job and the people who filmed the movies didn't have this kind of equipment. The Montana Movie had been taken on August 15, 1950, by Nick Mariana, the manager of the Great Falls baseball team. It showed two large bright lights flying across the blue sky in an echelon formation. There were no clouds in the movie to give an indication of the UFO's speed, but at one time they passed behind a water tower. The lights didn't show any detail; they appeared to be large circular objects. Mariana had sent his movies to the Air Force back in 1950, but in 1950 there was no interest in the UFO so, after a quick viewing, Project Grudge had written them off as "the reflections from two F-94 jet fighters that were in the area." In 1952, at the request of the Pentagon, I reopened the investigation of the Montana Movie. Working through an intelligence officer at the Great Falls AFB, I had Mariana reinterrogated and obtained a copy of his movie, which I sent to the photo lab. When the photo lab got the movie, they had a little something to work with because the two UFO's had passed behind a reference point, the water tower. Their calculations quickly confirmed that the objects were not birds, balloons, or meteors. Balloons drift with the wind and the wind was not blowing in the direction that the two UFO's were traveling. No exact speeds could be measured, but the lab could determine that the lights were traveling too fast to be birds and too slow to be meteors. This left airplanes as the only answer. The intelligence officer at Great Falls had dug through huge stacks of files and found that only two airplanes, two F-94's, were near the city during the sighting and that they had landed about two minutes afterwards. Both Mariana and his secretary, who had also seen the UFO's, had said that the two jets had appeared in another part of the sky only a minute or two after the two UFO's had disappeared in the southeast. This in itself would eliminate the jets as candidates for the UFO's, but we wanted to double-check. The two circular lights didn't look like F-94's, but anyone who has done any flying can tell you that an airplane so far away that it can't be seen can suddenly catch the sun's rays and make a brilliant flash. First we studied the flight paths of the two F-94's. We knew the landing pattern that was being used on the day of the sighting, and we knew when the two F-94's landed. The two jets just weren't anywhere close to where the two UFO's had been. Next we studied each individual light and both appeared to be too steady to be reflections. We drew a blank on the Montana Movie--it was an unknown. We also drew a blank on the Tremonton Movie, a movie that had been taken by a Navy Chief Photographer, Warrant Officer Delbert C. Newhouse, on July 2, 1952. Our report on the incident showed that Newhouse, his wife, and their two children were driving to Oakland, California, from the east coast on this eventful day. They had just passed through Tremonton, Utah, a town north of Salt Lake City, and had traveled about 7 miles on U.S. Highway 30S when Mrs. Newhouse noticed a group of objects in the sky. She pointed them out to her husband; he looked, pulled over to the side of the road, stopped the car, and jumped out to get a better look. He didn't have to look very long to realize that something highly unusual was taking place because in his twenty-one years in the Navy and 2,000 hours' flying time as an aerial photographer, he'd never seen anything like this. About a dozen shiny disklike objects were "milling around the sky in a rough formation." Newhouse had his movie camera so he turned the turret around to a 3- inch telephoto lens and started to photograph the UFO's. He held the camera still and took several feet of film, getting all of the bright objects in one photo. All of the UFO's had stayed in a compact group from the time the Newhouse family had first seen them, but just before they disappeared over the western horizon one of them left the main group and headed east. Newhouse swung his camera around and took several shots of it, holding his camera steady and letting the UFO pass through the field of view before it disappeared in the east. When I received the Tremonton films I took them right over to the Wright Field photo lab, along with the Montana Movie, and the photo technicians and I ran them twenty or thirty times. The two movies were similar in that in both of them the objects appeared to be large circular lights--in neither one could you see any detail. But, unlike the Montana Movie, the lights in the Tremonton Movie would fade out, then come back in again. This fading immediately suggested airplanes reflecting light, but the roar of a king-sized dogfight could have been heard for miles and the Newhouse family had heard no sound. We called in several fighter pilots and they watched the UFO's circling and darting in and out in the cloudless blue sky. Their unqualified comment was that no airplane could do what the UFO's were doing. Balloons came under suspicion, but the lab eliminated them just as quickly by studying the kind of a reflection given off by a balloon-- it is a steady reflection since a balloon is spherical. Then, to further scuttle the balloon theory, clusters of balloons are tied together and don't mill around. Of course, the lone UFO that took off to the east by itself was the biggest argument against balloons. Newhouse told an intelligence officer from the Western Air Defense Forces that he had held his camera still and let this single UFO fly through the field of view, so the people in the lab measured its angular velocity. Unfortunately there were no clouds in the sky, nor was he able to include any of the ground in the pictures, so our estimates of angular velocity had to be made assuming that the photographer held his camera still. Had the lone UFO been 10 miles away it would have been traveling several thousand miles an hour. After studying the movies for several weeks, the Air Force photo lab at Wright Field gave up. All they had to say was, "We don't know what they are but they aren't airplanes or balloons, and we don't think they are birds." While the lab had been working on the movies at Wright Field, Major Fournet had been talking to the Navy photo people at Anacostia; they thought they had some good ideas on how to analyze the movies, so as soon as we were through with them I sent them to Major Fournet and he took them over to the Navy lab. The Navy lab spent about two months studying the films and had just completed their analysis. The men who had done the work were on hand to brief the panel of scientists on their analysis after the panel had seen the movies. We darkened the room and I would imagine that we ran each film ten times before every panel member was satisfied that he had seen and could remember all of the details. We ran both films together so that the men could compare them. The Navy analysts didn't use the words "interplanetary spacecraft" when they told of their conclusions, but they did say that the UFO's were intelligently controlled vehicles and that they weren't airplanes or birds. They had arrived at this conclusion by making a frame-by-frame study of the motion of the lights and the changes in the lights' intensity. When the Navy people had finished with their presentation, the scientists had questions. None of the panel members were trying to find fault with the work the Navy people had done, but they weren't going to accept the study until they had meticulously searched for every loophole. Then they found one. In measuring the brilliance of the lights, the photo analysts had used an instrument called a densitometer. The astronomer on the panel knew all about measuring the density of an extremely small photographic image with a densitometer because he did it all the time in his studies of the stars. And the astronomer didn't think that the Navy analysts had used the correct technique in making their measurements. This didn't necessarily mean that their data were all wrong, but it did mean that they should recheck their work. When the discussion of the Navy's report ended, one of the scientists asked to see the Tremonton Movie again; so I had the projectionists run it several more times. The man said that he thought the UFO's could be sea gulls soaring on a thermal current. He lived in Berkeley and said that he'd seen gulls high in the air over San Francisco Bay. We had thought of this possibility several months before because the area around the Great Salt Lake is inhabited by large white gulls. But the speed of the lone UFO as it left the main group had eliminated the gulls. I pointed this out to the physicist. His answer was that the Navy warrant officer might have thought he had held the camera steady, but he could have "panned with the action" unconsciously. This would throw all of our computations 'way off. I agreed with this, but I couldn't agree that they were sea gulls. But several months later I was in San Francisco waiting for an airliner to Los Angeles and I watched gulls soaring in a cloudless sky. They were "riding a thermal," and they were so high that you couldn't see them until they banked just a certain way; then they appeared to be a bright white flash, much larger than one would expect from sea gulls. There was a strong resemblance to the UFO's in the Tremonton Movie. But I'm not sure that this is the answer. The presentation of the two movies ended Project Blue Book's part of the meeting. In five days we had given the panel of scientists every pertinent detail in the history of the UFO, and it was up to them to tell us if they were real--some type of vehicle flying through our atmosphere. If they were real, then they would have to be spacecraft because no one at the meeting gave a second thought to the possibility that the UFO's might be a supersecret U.S. aircraft or a Soviet development. The scientists knew everything that was going on in the U.S. and they knew that no country in the world had developed their technology far enough to build a craft that would perform as the UFO's were reported to do. In addition, we were spending billions of dollars on the research and development and the procurement of airplanes that were just nudging the speed of sound. It would be absurd to think that these billions were being spent to cover the existence of a UFO-type weapon. And it would be equally absurd to think that the British, French, Russians or any other country could be far enough ahead of us to have a UFO. The scientists spent the next two days pondering a conclusion. They reread reports and looked at the two movies again and again, they called other scientists to double-check certain ideas that they had, and they discussed the problem among themselves. Then they wrote out their conclusions and each man signed the document. The first paragraph said: We as a group do not believe that it is impossible for some other celestial body to be inhabited by intelligent creatures. Nor is it impossible that these creatures could have reached such a state of development that they could visit the earth. However, there is nothing in all of the so-called "flying saucer" reports that we have read that would indicate that this is taking place. The Tremonton Movie had been rejected as proof but the panel did leave the door open a crack when they suggested that the Navy photo lab redo their study. But the Navy lab never rechecked their report, and it was over a year later before new data came to light. After I got out of the Air Force I met Newhouse and talked to him for two hours. I've talked to many people who have reported UFO's, but few impressed me as much as Newhouse. I learned that when he and his family first saw the UFO's they were close to the car, much closer than when he took the movie. To use Newhouse's own words, "If they had been the size of a B-29 they would have been at 10,000 feet altitude." And the Navy man and his family had taken a good look at the objects--they looked like "two pie pans, one inverted on the top of the other!" He didn't just _think_ the UFO's were disk-shaped; he _knew_ that they were; he had plainly seen them. I asked him why he hadn't told this to the intelligence officer who interrogated him. He said that he had. Then I remembered that I'd sent the intelligence officer a list of questions I wanted Newhouse to answer. The question "What did the UFO's look like?" wasn't one of them because when you have a picture of something you don't normally ask what it looks like. Why the intelligence officer didn't pass this information on to us I'll never know. The Montana Movie was rejected by the panel as positive proof because even though the two observers said that the jets were in another part of the sky when they saw the UFO's and our study backed them up, there was still a chance that the two UFO's could have been the two jets. We couldn't prove the UFO's were the jets, but neither could we prove they weren't. The controversial study of the UFO's' motions that Major Fournet had presented was discarded. All of the panel agreed that if there had been some permanent record of the motion of the UFO's, a photograph of a UFO's flight path or a photograph of a UFO's track on a radarscope, they could have given the study much more weight. But in every one of the ten or twenty reports that were offered as proof that the UFO's were intelligently controlled, the motions were only those that the observer had seen. And the human eye and mind are not accurate recorders. How many different stories do you get when a group of people watch two cars collide at an intersection? Each of the fifty of our best sightings that we gave the scientists to study had some kind of a loophole. In many cases the loopholes were extremely small, but scientific evaluation has no room for even the smallest of loopholes and we had asked for a scientific evaluation. When they had finished commenting on the reports, the scientists pointed out the seriousness of the decision they had been asked to make. They said that they had tried hard to be objective and not to be picayunish, but actually all we had was circumstantial evidence. Good circumstantial evidence, to be sure, but we had nothing concrete, no hardware, no photos showing any detail of a UFO, no measured speeds, altitudes, or sizes--nothing in the way of good, hard, cold, scientific facts. To stake the future course of millions of lives on a decision based upon circumstantial evidence would be one of the gravest mistakes in the history of the world. In their conclusions they touched upon the possibility that the UFO's might be some type of new or yet undiscovered natural phenomenon. They explained that they hadn't given this too much credence; however, if the UFO's were a new natural phenomenon, the reports of their general appearance should follow a definite pattern-- the UFO reports didn't. This ended the section of the panel's report that covered their conclusions. The next section was entitled, "Recommendations." I fully expected that they would recommend that we as least reduce the activities of Project Blue Book if not cancel it entirely. I didn't like this one bit because I was firmly convinced that we didn't have the final answer. We needed more and better proof before a final yes or no could be given. The panel didn't recommend that the activities of Blue Book be cut back, and they didn't recommend that it be dropped. They recommended that it be expanded. Too many of the reports had been made by credible observers, the report said, people who should know what they're looking at--people who think things out carefully. Data that was out of the circumstantial-evidence class was badly needed. And the panel must have been at least partially convinced that an expanded effort would prove something interesting because the expansion they recommended would require a considerable sum of money. The investigative force of Project Blue Book should be quadrupled in size, they wrote, and it should be staffed by specially trained experts in the fields of electronics, meteorology, photography, physics, and other fields of science pertinent to UFO investigations. Every effort should be made to set up instruments in locations where UFO sightings are frequent, so that data could be measured and recorded during a sighting. In other locations around the country military and civilian scientists should be alerted and instructed to use every piece of available equipment that could be used to track UFO's. And lastly, they said that the American public should be told every detail of every phase of the UFO investigation--the details of the sightings, the official conclusions, and why the conclusions were made. This would serve a double purpose; it would dispel any of the mystery that security breeds and it would keep the Air Force on the ball--sloppy investigations and analyses would never occur. When the panel's conclusions were made known in the government, they met with mixed reactions. Some people were satisfied, but others weren't. Even the opinions of a group of the country's top scientists couldn't overcome the controversy that had dogged the UFO for five years. Some of those who didn't like the decision had sat in on the UFO's trial as spectators and they felt that the "jury" was definitely prejudiced-- afraid to stick their necks out. They could see no reason to continue to assume that the UFO's weren't interplanetary vehicles. CHAPTER SEVENTEEN What Are UFO's? While the scientists were in Washington, D.C., pondering over the UFO, the UFO's weren't just sitting idly by waiting to find out what they were--they were out doing a little "lobbying" for the cause-- keeping the interest stirred up. And they were doing a good job, too. It was just a few minutes before midnight on January 28, 1953, when a message flashed into Wright-Patterson for Project Blue Book. It was sent "Operational Immediate," so it had priority handling; I was reading it by 12:30A.M. A pilot had chased a UFO. The report didn't have many details but it did sound good. It gave the pilot's name and said that he could be reached at Moody AFB. I put in a long-distance call, found the pilot, and flipped on my recorder so that I could get his story word for word. He told me that he had been flying an F-86 on a "round-robin" navigation flight from Moody AFB to Lawson AFB to Robins AFB, then back to Moody--all in Georgia. At exactly nine thirty-five he was at 6,000 feet, heading toward Lawson AFB on the first leg of his flight. He remembered that he had just looked down and had seen the lights of Albany, Georgia; then he'd looked up again and seen this bright white light at "ten o'clock high." It was an unusually bright light, and he said that he thought this was why it was so noticeable among the stars. He flew on for a few minutes watching it as he passed over Albany. He decided that it must be an extremely bright star or another airplane--except it just didn't look right. It had too much of a definitely circular shape. It was a nice night to fly and he had to get in so much time anyway, so he thought he'd try to get a little closer to it. If it was an airplane, chances were he could close in and if it was a star, he should be able to climb up to 30,000 feet and the light shouldn't change its relative position. He checked his oxygen supply, increased the r.p.m. of the engine, and started to climb. In three or four minutes it was obvious that he was getting above the light, and he watched it; it had moved in relation to the stars. It must be an airplane then, he'd decided--an airplane so far away that he couldn't see its red and green wing tip lights. Since he'd gone this far, he decided that he'd get closer and make sure it _was_ an airplane; so he dropped the nose of the F-86 and started down. As the needle on the machmeter nudged the red line, he saw that he was getting closer because the light was getting bigger, but still he couldn't see any lights other than the one big white one. Then it wasn't white any longer; it was changing color. In about a two-second cycle it changed from white to red, then back to white again. It went through this cycle two or three times, and then before he could realize what was going on, he told me, the light changed in shape to a perfect triangle. Then it split into two triangles, one above the other. By this time he had leveled off and wasn't closing in any more. In a flash the whole thing was gone. He used the old standard description for a disappearing UFO: "It was just like someone turning off a light--it's there, then it's gone." I asked him what he thought he'd seen. He'd thought about flying saucers, he said, but he "just couldn't swallow those stories." He thought he had a case of vertigo and the more he thought about it, the surer he was that this was the answer. He'd felt pretty foolish, he told me, and he was glad that he was alone. Up ahead he saw the sprawling lights of Fort Benning and Lawson AFB, his turning point on the flight, and he'd started to turn but then he'd checked his fuel. The climb had used up quite a bit, so he changed his mind about going to Robins AFB and started straight back to Moody. He called in to the ground station to change his flight plan, but before he could say anything the ground radio operator asked him if he'd seen a mysterious light. Well--he'd seen a light. Then the ground operator proceeded to tell him that the UFO chase had been watched on radar. First the radar had the UFO target on the scope, and it was a UFO because it was traveling much too slowly to be an airplane. Then the radar operators saw the F-86 approach, climb, and make a shallow dive toward the UFO. At first the F-86 had closed in on the UFO, but then the UFO had speeded up just enough to maintain a comfortable lead. This went on for two or three minutes; then it had moved off the scope at a terrific speed. The radar site had tried to call him, the ground station told the F-86 pilot, but they couldn't raise him so the message had to be relayed through the tower. Rack up two more points for the UFO--another unknown and another confirmed believer. Two or three weeks after the meeting of the panel of scientists in Washington I received word that Project Blue Book would follow the recommendations that the panel had made. I was to start implementing the plan right away. Our proposal for setting up instruments had gone to the Pentagon weeks before, so that was already taken care of. We needed more people, so I drew up a new organizational cable that called for more investigators and analysts and sent it through to ATIC's personnel section. About this time in the history of the UFO the first of a series of snags came up. The scientists had strongly recommended that we hold nothing back--give the public everything. Accordingly, when the press got wind of the Tremonton Movie, which up until this time had been a closely guarded secret, I agreed to release it for the newsmen to see. I wrote a press release which was O.K.'d by General Garland, then the chief of ATIC, and sent it to the Pentagon. It told what the panel had said about the movies, "until proved otherwise there is no reason why the UFO's couldn't have been sea gulls." Then the release went on to say that we weren't sure exactly what the UFO's were, the sea gull theory was only an opinion. When the Pentagon got the draft of the release they screamed, "No!" No movie for the press and no press release. The sea gull theory was too weak, and we had a new publicity policy as of now--don't say anything. This policy, incidentally, is still in effect. The January 7, 1955, issue of the _Air_ _Force_ _Information_ _Services_ _Letter_ said, in essence, people in the Air Force are talking too much about UFO's-- shut up. The old theory that if you ignore them they'll go away is again being followed. Inside of a month the UFO project took a few more hard jolts. In December of 1952 I'd asked for a transfer. I'd agreed to stay on as chief of Blue Book until the end of February so that a replacement could be obtained and be broken in. But no replacement showed up. And none showed up when Lieutenant Rothstien's tour of active duty ended, when Lieutenant Andy Flues transferred to the Alaskan Air Command, or when others left. When I left the UFO project for a two-month tour of temporary duty in Denver, Lieutenant Bob Olsson took over as chief. His staff consisted of Airman First Class Max Futch. Both men were old veterans of the UFO campaign of '52, but two people can do only so much. When I came back to ATIC in July 1953 and took over another job, Lieutenant Olsson was just getting out of the Air Force and Al/c Futch was now it. He said that he felt like the President of Antarctica on a non-expedition year. In a few days I again had Project Blue Book, as an additional duty this time, and I had orders to "build it up." While I had been gone, our instrumentation plan had been rejected. Higher headquarters had decided against establishing a net of manned tracking stations, astronomical cameras tied in with radars, and our other proposed instrumentation. General Garland had argued long and hard for the plan, but he'd lost. It was decided that the cameras with diffraction gratings over the lenses, the cameras that had been under development for a year, would suffice. The camera program had started out as a top-priority project, but it had lost momentum fast when we'd tested these widely publicized instruments and found that they wouldn't satisfactorily photograph a million-candle power flare at 450 yards. The cameras themselves were all right, but in combination with the gratings, they were no good. However, Lieutenant Olsson had been told to send them out, so he sent them out. The first thing that I did when I returned to Project Blue Book was to go over the reports that had come in while I was away. There were several good reports but only one that was exceptional. It had taken place at Luke AFB, Arizona, the Air Force's advanced fighter-bomber school that is named after the famous "balloon buster" of World War I, Lieutenant Frank Luke, Jr. It was a sighting that produced some very interesting photographs. There were only a few high cirrus clouds in the sky late on the morning of March 3 when a pilot took off from Luke in an F-84 jet to log some time. He had been flying F-51's in Korea and had recently started to check out in the jets. He took off, cleared the traffic pattern, and started climbing toward Blythe Radio, about 130 miles west of Luke. He'd climbed for several minutes and had just picked up the coded letters BLH that identified Blythe Radio when he looked up through the corner glass in the front part of his canopy--high at about two o'clock he saw what he thought was an airplane angling across his course from left to right leaving a long, thin vapor trail. He glanced down at his altimeter and saw that he was at 23,000 feet. The object that was leaving the vapor trail must really be high, he remembered thinking, because he couldn't see any airplane at the head of it. He altered his course a few degrees to the right so that he could follow the trail and increased his rate of climb. Before long he could tell that he was gaining on the object, or whatever was leaving the vapor trail, because he was under the central part of it. But he still couldn't see any object. This was odd, he thought, because vapor trails don't just happen; something has to leave them. His altimeter had ticked off another 12,000 feet and he was now at 35,000. He kept on climbing, but soon the '84 began to mush; it was as high as it would go. The pilot dropped down 1,000 feet and continued on--now he was below the front of the trail, but still no airplane. This bothered him too. Nothing that we have flies over 55,000 feet except a few experimental airplanes like the D-558 or those of the "X" series, and they don't stray far from Edwards AFB in California. He couldn't be more than 15,000 feet from the front of the trail, and you can recognize any kind of an airplane 15,000 feet away in the clear air of the substratosphere. He looked and he looked and he looked. He rocked the F-84 back and forth thinking maybe he had a flaw in the plexiglass of the canopy that was blinking out the airplane, but still no airplane. Whatever it was, it was darn high or darn small. It was moving about 300 miles an hour because he had to pull off power and "S" to stay under it. He was beginning to get low on fuel about this time so he hauled up the nose of the jet, took about 30 feet of gun camera film, and started down. When he landed and told his story, the film was quickly processed and rushed to the projection room. It showed a weird, thin, forked vapor trail--but no airplane. Lieutenant Olsson and Airman Futch had worked this one over thoroughly. The photo lab confirmed that the trail was definitely a vapor trail, not a freak cloud formation. But Air Force Flight Service said, "No other airplanes in the area," and so did Air Defense Command, because minutes after the F-84 pilot broke off contact, the "object" had passed into an ADIZ--Air Defense Identification Zone--and radar had shown nothing. There was one last possibility: Blue Book's astronomer said that the photos looked exactly like a meteor's smoke trail. But there was one hitch: the pilot was positive that the head of the vapor trail was moving at about 300 miles an hour. He didn't know exactly how much ground he'd covered, but when he first picked up Blythe Radio he was on Green 5 airway, about 30 miles west of his base, and when he'd given up the chase he'd gotten another radio bearing, and he was now almost up to Needles Radio, 70 miles north of Blythe. He could see a lake, Lake Mojave, in the distance. Could a high-altitude jet-stream wind have been blowing the smoke cloud? Futch had checked this--no. The winds above 20,000 feet were the usual westerlies and the jet stream was far to the north. Several months later I talked to a captain who had been at Luke when this sighting occurred. He knew the F-84 pilot and he'd heard him tell his story in great detail. I won't say that he was a confirmed believer, but he was interested. "I never thought much about these reports before," he said, "but I know this guy well. He's not nuts. What do you think he saw?" I don't know what he saw. Maybe he didn't travel as far as he thought he did. If he didn't, then I'd guess that he saw a meteor's smoke trail. But if he did know that he'd covered some 80 miles during the chase, I'd say that he saw a UFO--a real one. And I find it hard to believe that pilots don't know what they're doing. During the summer of 1953, UFO reports dropped off considerably. During May, June, and July of 1952 we'd received 637 good reports. During the same months in 1953 we received only seventy-six. We had been waiting for the magic month of July to roll around again because every July there had been the sudden and unexplained peak in reporting; we wanted to know if it would happen again. It didn't-- only twenty-one reports came in, to make July the lowest month of the year. But July did bring new developments. Project Blue Book got a badly needed shot in the arm when an unpublicized but highly important change took place: another intelligence agency began to take over all field investigations. Ever since I'd returned to the project, the orders had been to build it up--get more people--do what the panel recommended. But when I'd asked for more people, all I got was a polite "So sorry." So, I did the next best thing and tried to find some organization already in being which could and would help us. I happened to be expounding my troubles one day at Air Defense Command Headquarters while I was briefing General Burgess, ADC's Director of Intelligence, and he told me about his 4602nd Air Intelligence Squadron, a specialized intelligence unit that had recently become operational. Maybe it could help--he'd see what he could work out, he told me. Now in the military all commitments to do something carry an almost standard time factor. "I'll expedite it," means nothing will happen for at least two weeks. "I'll do it right away," means from a month to six weeks. An answer like, "I'll see what I can work out," requires writing a memo that explains what the person was going to see if he could work out and sealing it in a time capsule for preservation so that when the answer finally does come through the future generation that receives it will know how it all started. But I underestimated the efficiency of the Air Defense Command. Inside of two weeks General Burgess had called General Garland, they'd discussed the problem, and I was back in Colorado Springs setting up a program with Colonel White's 4602nd. The 4602nd's primary function is to interrogate captured enemy airmen during wartime; in peacetime all that they can do is participate in simulated problems. Investigating UFO reports would supplement these problems and add a factor of realism that would be invaluable in their training. The 4602nd had field teams spread out all over the United States, and these teams could travel anywhere by airplane, helicopter, canoe, jeep, or skis on a minute's notice. The field teams had already established a working contact with the highway patrols, sheriffs' offices, police, and the other military in their respective areas, so they were in an excellent position to collect facts about a UFO report. Each member of the field teams had been especially chosen and trained in the art of interrogation, and each team had a technical specialist. We couldn't have asked for a better ally. Project Blue Book was once more back in business. Until the formal paper work went through, our plan was that whenever a UFO report worth investigating came in we would call the 4602nd and they would get a team out right away. The team would make a thorough investigation and wire us their report. If the answer came back "Unknown," we would study the details of the sighting and, with the help of Project Bear, try to find the answer. A few weeks after the final plans had been made with the 4602nd, I again bade farewell to Project Blue Book. In a simple ceremony on the poop deck of one of the flying saucers that I frequently have been accused of capturing, before a formation of the three-foot-tall green men that I have equally as frequently been accused of keeping prisoner, I turned my command over to Al/c Max Futch and walked out the door into civilian life with separation orders in hand. The UFO's must have known that I was leaving because the day I found out that officers with my specialty, technical intelligence, were no longer on the critical list and that I could soon get out of the service, they really put on a show. The show they put on is still the best UFO report in the Air Force files. I first heard about the sighting about two o'clock on the morning of August 13, 1953, when Max Futch called me from ATIC. A few minutes before a wire had come in carrying a priority just under that reserved for flashing the word the U.S. has been attacked. Max had been called over to ATIC by the OD to see the report, and he thought that I should see it. I was a little hesitant to get dressed and go out to the base, so I asked Max what he thought about the report. His classic answer will go down in UFO history, "Captain," Max said in his slow, pure Louisiana drawl, "you know that for a year I've read every flying saucer report that's come in and that I never really believed in the things." Then he hesitated and added, so fast that I could hardly understand him, "But you should read _this_ wire." The speed with which he uttered this last statement was in itself enough to convince me. When Max talked fast, something was important. A half hour later I was at ATIC--just in time to get a call from the Pentagon. Someone else had gotten out of bed to read his copy of the wire. I used the emergency orders that I always kept in my desk and caught the first airliner out of Dayton to Rapid City, South Dakota. I didn't call the 4602nd because I wanted to investigate this one personally. I talked to everyone involved in the incident and pieced together an amazing story. Shortly after dark on the night of the twelfth, the Air Defense Command radar station at Ellsworth AFB, just east of Rapid City, had received a call from the local Ground Observer Corps filter center. A lady spotter at Black Hawk, about 10 miles west of Ellsworth, had reported an extremely bright light low on the horizon, off to the northeast. The radar had been scanning an area to the west, working a jet fighter in some practice patrols, but when they got the report they moved the sector scan to the northeast quadrant. There was a target exactly where the lady reported the light to be. The warrant officer, who was the duty controller for the night, told me that he'd studied the target for several minutes. He knew how weather could affect radar but this target was "well defined, solid, and bright." It seemed to be moving, but very slowly. He called for an altitude reading, and the man on the height-finding radar checked his scope. He also had the target--it was at 16,000 feet. The warrant officer picked up the phone and asked the filter center to connect him with the spotter. They did, and the two people compared notes on the UFO's position for several minutes. But right in the middle of a sentence the lady suddenly stopped and excitedly said, "It's starting to move--it's moving southwest toward Rapid." The controller looked down at his scope and the target was beginning to pick up speed and move southwest. He yelled at two of his men to run outside and take a look. In a second or two one of them shouted back that they could both see a large bluish-white light moving toward Rapid City. The controller looked down at his scope--the target was moving toward Rapid City. As all three parties watched the light and kept up a steady cross conversation of the description, the UFO swiftly made a wide sweep around Rapid City and returned to its original position in the sky. A master sergeant who had seen and heard the happenings told me that in all his years of duty--combat radar operations in both Europe and Korea--he'd never been so completely awed by anything. When the warrant officer had yelled down at him and asked him what he thought they should do, he'd just stood there. "After all," he told me, "what in hell could we do--they're bigger than all of us." But the warrant officer did do something. He called to the F-84 pilot he had on combat air patrol west of the base and told him to get ready for an intercept. He brought the pilot around south of the base and gave him a course correction that would take him right into the light, which was still at 16,000 feet. By this time the pilot had it spotted. He made the turn, and when he closed to within about 3 miles of the target, it began to move. The controller saw it begin to move, the spotter saw it begin to move and the pilot saw it begin to move--all at the same time. There was now no doubt that all of them were watching the same object. Once it began to move, the UFO picked up speed fast and started to climb, heading north, but the F-84 was right on its tail. The pilot would notice that the light was getting brighter, and he'd call the controller to tell him about it. But the controller's answer would always be the same, "Roger, we can see it on the scope." There was always a limit as to how near the jet could get, however. The controller told me that it was just as if the UFO had some kind of an automatic warning radar linked to its power supply. When something got too close to it, it would automatically pick up speed and pull away. The separation distance always remained about 3 miles. The chase continued on north--out of sight of the lights of Rapid City and the base--into some very black night. When the UFO and the F-84 got about 120 miles to the north, the pilot checked his fuel; he had to come back. And when I talked to him, he said he was damn glad that he was running out of fuel because being out over some mighty desolate country alone with a UFO can cause some worry. Both the UFO and the F-84 had gone off the scope, but in a few minutes the jet was back on, heading for home. Then 10 or 15 miles behind it was the UFO target also coming back. While the UFO and the F-84 were returning to the base--the F-84 was planning to land--the controller received a call from the jet interceptor squadron on the base. The alert pilots at the squadron had heard the conversations on their radio and didn't believe it. "Who's nuts up there?" was the comment that passed over the wire from the pilots to the radar people. There was an F-84 on the line ready to scramble, the man on the phone said, and one of the pilots, a World War II and Korean veteran, wanted to go up and see a flying saucer. The controller said, "O.K., go." In a minute or two the F-84 was airborne and the controller was working him toward the light. The pilot saw it right away and closed in. Again the light began to climb out, this time more toward the northeast. The pilot also began to climb, and before long the light, which at first had been about 30 degrees above his horizontal line of sight, was now below him. He nosed the '84 down to pick up speed, but it was the same old story--as soon as he'd get within 3 miles of the UFO, it would put on a burst of speed and stay out ahead. Even though the pilot could see the light and hear the ground controller telling him that he was above it, and alternately gaining on it or dropping back, he still couldn't believe it--there must be a simple explanation. He turned off all of his lights--it wasn't a reflection from any of the airplane's lights because there it was. A reflection from a ground light, maybe. He rolled the airplane--the position of the light didn't change. A star--he picked out three bright stars near the light and watched carefully. The UFO moved in relation to the three stars. Well, he thought to himself, if it's a real object out there, my radar should pick it up too; so he flipped on his radar-ranging gunsight. In a few seconds the red light on his sight blinked on--something real and solid was in front of him. Then he was scared. When I talked to him, he readily admitted that he'd been scared. He'd met MD 109's, FW 190's and ME 262's over Germany and he'd met MIG-15's over Korea but the large, bright, bluish-white light had scared him--he asked the controller if he could break off the intercept. This time the light didn't come back. When the UFO went off the scope it was headed toward Fargo, North Dakota, so the controller called the Fargo filter center. "Had they had any reports of unidentified lights?" he asked. They hadn't. But in a few minutes a call came back. Spotter posts on a southwest- northeast line a few miles west of Fargo had reported a fast-moving, bright bluish-white light. This was an unknown--the best. The sighting was thoroughly investigated, and I could devote pages of detail on how we looked into every facet of the incident; but it will suffice to say that in every facet we looked into we saw nothing. Nothing but a big question mark asking what was it. When I left Project Blue Book and the Air Force I severed all official associations with the UFO. But the UFO is like hard drink; you always seem to drift back to it. People I've met, people at work, and friends of friends are continually asking about the subject. In the past few months the circulation manager of a large Los Angeles newspaper, one of Douglas Aircraft Company's top scientists, a man who is guiding the future development of the supersecret Atlas intercontinental guided missile, a movie star, and a German rocket expert have called me and wanted to get together to talk about UFO's. Some of them had seen one. I have kept up with the activity of the UFO and Project Blue Book over the past two years through friends who are still in intelligence. Before Max Futch got out of the Air Force and went back to law school he wrote to me quite often and a part of his letters were always devoted to the latest about the UFO's. Then I make frequent business trips to ATIC, and I always stop in to see Captain Charles Hardin, who is now in charge of Blue Book, for a "What's new?" I always go to ATIC with the proper security clearances so I'm sure I get a straight answer to my question. Since I left ATIC, the UFO's haven't gone away and neither has the interest. There hasn't been too much about them in the newspapers because of the present Air Force policy of silence, but they're with us. That the interest is still with us is attested to by the fact that in late 1953 Donald Keyhoe's book about UFO's, _Flying_ _Saucers_ _from_ _Outer_ _Space_, immediately appeared on best seller lists. The book was based on a few of our good UFO reports that were released to the press. To say that the book is factual depends entirely upon how one uses the word. The details of the specific UFO sightings that he credits to the Air Force are factual, but in his interpretations of the incidents he blasts way out into the wild blue yonder. During the past two years the bulk of the UFO activity has taken place in Europe. I might add here that I have never seen any recent official UFO reports or studies from other countries; all of my information about the European Flap came from friends. But when these friends are in the intelligence branches of the U.S. Air Force, the RAF, and the Royal Netherlands Air Force, the data can be considered at least good. The European Flap started in the summer of 1953, when reports began to pop up in England and France. Quality-wise these first reports weren't too good, however. But then, like a few reports that occurred early in the stateside Big Flap of 1952, sightings began to drift in that packed a bit of a jolt. Reports came in that had been made by personal friends of the brass in the British and French Air Forces. Then some of the brass saw them. Corners of mouths started down. In September several radar sites in the London area picked up unidentified targets streaking across the city at altitudes of from 44,000 to 68,000 feet. The crews who saw the targets said, "Not weather," and some of these crews had been through the bloody Battle of Britain. They knew their radar. In October the crew of a British European Airways airliner reported that a "strange aerial object" had paced their twin-engined Elizabethan for thirty minutes. Then on November 3, about two-thirty in the afternoon, radar in the London area again picked up targets. This time two Vampire jets were scrambled and the pilots saw a "strange aerial object." The men at the radar site saw it too; through their telescope it looked like a "flat, white-coloured tennis ball." The flap continued into 1954. In January those people who officially keep track of the UFO's pricked up their ears when the report of two Swedish airline pilots came in. The pilots had gotten a good look before the UFO had streaked into a cloud bank. It looked like a discus with a hump in the middle. On through the spring reports poured out of every country in Europe. Some were bad, some were good. On July 3, 1954, at eight-fifteen in the morning, the captain, the officers and 463 passengers on a Dutch ocean liner watched a "greenish-colored, saucer-shaped object about half the size of a full moon" as it sped across the sky and disappeared into a patch of high clouds. There was one fully documented and substantiated case of a "landing" during the flap. On August 25 two young ladies in Mosjoen, Norway, made every major newspaper in the world when they encountered a "saucer-man." They said that they were picking berries when suddenly a dark man, with long shaggy hair, stepped out from behind some bushes. He was friendly; he stepped right up to them and started to talk rapidly. The two young ladies could understand English but they couldn't understand him. At first they were frightened, but his smile soon "disarmed" them. He drew a few pictures of flying saucers and pointed up in the sky. "He was obviously trying to make a point," one of the young ladies said. A few days later it was discovered that the man from "outer space" was a lost USAF helicopter pilot who was flying with NATO forces in Norway. As I've always said, "Ya gotta watch those Air Force pilots-- especially those shaggy-haired ones from Brooklyn." The reporting spread to Italy, where thousands of people in Rome saw a strange cigar-shaped object hang over the city for forty minutes. Newspapers claimed that Italian Air Force radar had the UFO on their scopes, but as far as I could determine, this was never officially acknowledged. In December a photograph of two UFO's over Taormina, Sicily, appeared in many newspapers. The picture showed three men standing on a bridge, with a fourth running up with a camera. All were intently watching two disk-shaped objects. The photo looked good, but there was one flaw, the men weren't looking at the UFO's; they were looking off to the right of them. I'm inclined to agree with Captain Hardin of Blue Book--the photographer just fouled up on his double exposure. Sightings spread across southern Europe, and at the end of October, the Yugoslav Government expressed official interest. Belgrade newspapers said that a "thoughtful inquiry" would be set up, since reports had come from "control tower operators, weather stations and hundreds of farmers." But the part of the statement that swung the most weight was, "Scientists in astronomical observatories have seen these strange objects with their own eyes." During 1954 and the early part of 1955 my friends in Europe tried to keep me up-to-date on all of the better reports, but this soon approached a full-time job. Airline pilots saw them, radar picked them up, and military pilots chased them. The press took sides, and the controversy that had plagued the U.S. since 1947 bloomed forth in all its confusion. An ex-Air Chief Marshal in the RAF, Lord Dowding, went to bat for the UFO's. The Netherlands Air Chief of Staff said they can't be. Herman Oberth, the father of the German rocket development, said that the UFO's were definitely interplanetary vehicles. In Belgium a senator put the screws on the Secretary of Defense--he wanted an answer. The Secretary of Defense questioned the idea that the saucers were "real" and said that the military wasn't officially interested. In France a member of parliament received a different answer--the French military was interested. The French General Staff had set up a committee to study UFO reports. In Italy, Clare Boothe Luce, American Ambassador to Italy, said that she had seen a UFO and had no idea what it could be. Halfway around the world, in Australia, the UFO's were busy too. At Canberra Airport the pilot of an RAAF Hawker Sea Fury and a ground radar station teamed up to get enough data to make an excellent radar- visual report. In early 1955 the flap began to die down about as rapidly as it had flared up, but it had left its mark--many more believers. Even the highly respected British aviation magazine, _Aeroplane_, had something to say. One of the editors took a long, hard look at the over-all UFO picture and concluded, "Really, old chaps--I don't know." Probably the most unique part of the whole European Flap was the fact that the Iron Curtain countries were having their own private flap. The first indications came in October 1954, when Rumanian newspapers blamed the United States for launching a drive to induce a "flying saucer psychosis" in their country. The next month the Hungarian Government hauled an "expert" up in front of the microphone so that he could explain to the populace that UFO's don't really exist because, "all 'flying saucer' reports originate in the bourgeois countries, where they are invented by the capitalist warmongers with a view to drawing the people's attention away from their economic difficulties." Next the U.S.S.R. itself took up the cry along the same lines when the voice of the Soviet Army, the newspaper _Red_ _Star_, denounced the UFO's as, you guessed it, capitalist propaganda. In 1955 the UFO's were still there because the day before the all- important May Day celebration, a day when the Soviet radio and TV are normally crammed with programs plugging the glory of Mother Russia to get the peasants in the mood for the next day, a member of the Soviet Academy of Sciences had to get on the air to calm the people's fears. He left out Wall Street and Dulles this time--UFO's just don't exist. It was interesting to note that during the whole Iron Curtain Flap, not one sighting or complimentary comment about the UFO's was made over the radio or in the newspapers; yet the flap continued. The reports were obviously being passed on by word of mouth. This fact seems to negate the theory that if the newspaper reporters and newscasters would give up the UFO's would go away. The people in Russia were obviously seeing something. While the European Flap was in progress, the UFO's weren't entirely neglecting the United States. The number of reports that were coming into Project Blue Book were below average, but there were reports. Many of them would definitely be classed as good, but the best was a report from a photo reconnaissance B-29 crew that encountered a UFO almost over Dayton. About 11:00A.M. on May 24, 1954, an RB-29 equipped with some new aerial cameras took off from Wright Field, one of the two airfields that make up Wright-Patterson AFB, and headed toward the Air Force's photographic test range in Indiana. At exactly twelve noon they were at 16,000 feet, flying west, about 15 miles northwest of Dayton. A major, a photo officer, was in the nose seat of the '29. All of the gun sights and the bombsight in the nose had been taken out, so it was like sitting in a large picture window--except you just can't get this kind of a view anyplace else. The major was enjoying it. He was leaning forward, looking down, when he saw an extremely bright circular-shaped object under and a little behind the airplane. It was so bright that it seemed to have a mirror finish. He couldn't tell how far below him it was but he was sure that it wasn't any higher than 6,000 feet above the ground, and it was traveling fast, faster than the B-29. It took only about six seconds to cross a section of land, which meant that it was going about 600 miles an hour. The major called the crew and told them about the UFO, but neither the pilot nor the copilot could see it because it was now directly under the B-29. The pilot was just in the process of telling him that he was crazy when one of the scanners in an aft blister called in; he and the other scanner could also see the UFO. Being a photo ship, the RB-29 had cameras--loaded cameras--so the logical thing to do would be to take a picture, but during a UFO sighting logic sometimes gets shoved into the background. In this case, however, it didn't, and the major reached down, punched the button on the intervalometer, and the big vertical camera in the aft section of the airplane clicked off a photo before the UFO sped away. The photo showed a circular-shaped blob of light exactly as the major had described it to the RB-29 crew. It didn't show any details of the UFO because the UFO was too bright; it was completely overexposed on the negative. The circular shape wasn't sharp either; it had fuzzy edges, but this could have been due to two things: its extreme brightness, or the fact that it was high, close to the RB-29, and out of focus. There was no way of telling exactly how high it was but if it were at 6,000 feet, as the major estimated, it would have been about 125 feet in diameter. Working with people from the photo lab at Wright-Patterson, Captain Hardin from Project Blue Book carried out one of the most complete investigations in UFO history. They checked aircraft flights, rephotographed the area from high and low altitude to see if they could pick up something on the ground that could have been reflecting light, and made a minute ground search of the area. They found absolutely nothing that could explain the round blob of light, and the incident went down as an unknown. Like all good "Unknown" UFO reports, there are as many opinions as to what the bright blob of light could have been as there are people who've seen the photo. "Some kind of light phenomenon" is the frequent opinion of those who don't believe. They point out that there is no shadow of any kind of a circular object showing on the ground--no shadow, nothing "solid." But if you care to take the time you can show that if the object, assuming that this is what it was, was above 4,000 feet the shadow would fall out of the picture. Then all you get is a blank look from the light phenomenon theorists. With the sighting from the RB-29 and the photograph, all of the other UFO reports that Blue Book has collected and all of those that came out of the European Flap, the big question--the key question-- is: What have the last two years of UFO activity brought out? Have there been any important developments? Some good reports have come in and the Air Force is sitting on them. During 1954 they received some 450 reports, and once again July was the peak month. In the first half of 1955 they had 189. But I can assure you that these reports add nothing more as far as proof is concerned. The quality of the reports has improved, but they still offer nothing more than the same circumstantial evidence that we presented to the panel of scientists in early 1953. There have been no reports in which the speed or altitude of a UFO has been measured, there have been no reliable photographs that show any details of a UFO, and there is no hardware. There is still no real proof. So a public statement that was made in 1952 still holds true: "The _possibility_ of the existence of interplanetary craft has never been denied by the Air Force, _but_ UFO reports offer absolutely no authentic evidence that such interplanetary spacecraft do exist." But with the UFO, what is lacking in proof is always made up for in opinions. To get a qualified opinion, I wrote to a friend, Frederick C. Durant. Mr. Durant, who is presently the director of a large Army Ordnance test station, is also a past president of the American Rocket Society and president of the International Astronautical Federation. For those who are not familiar with these organizations, the American Rocket Society is an organization established to promote interest and research in space flight and lists as its members practically every prominent scientist and engineer in the professional fields allied to aeronautics. The International Astronautical Federation is a world-wide federation of such societies. Mr. Durant has spent many hours studying UFO reports in the Project Blue Book files and many more hours discussing them with scientists the world over--scientists who are doing research and formulating the plans for space flight. I asked him what he'd heard about the UFO's during the past several years and what he thought about them. This was his reply: This past summer at the Annual Congress of the IAF at Innsbruck, as well as previous Congresses (Zurich, 1953, Stuttgart, 1952, and London, 1951), none of the delegates representing the rocket and space flight societies of all the countries involved had strong feelings on the subject of saucers. Their attitude was essentially the same as professional members of the American Rocket Society in this country. In other words, there appear to be no confirmed saucer fans in the hierarchy of the professional societies. I continue to follow the subject of UFO's primarily because of my being requested for comment on the interplanetary flight aspects. My personal feelings have not changed in the past four years, although I continue to keep an objective outlook. There are many other prominent scientists in the world whom I met while I was chief of Project Blue Book who, I'm sure, would give the same answer--they've not been able to find any proof, but they continue to keep an objective outlook. There are just enough big question marks sprinkled through the reports to keep their outlook objective. I know that there are many other scientists in the world who, although they haven't studied the Air Force's UFO files, would limit their comment to a large laugh followed by an "It can't be." But "It can't be's" are dangerous, if for no other reason than history has proved them so. Not more than a hundred years ago two members of the French Academy of Sciences were unseated because they supported the idea that "stones had fallen from the sky." Other distinguished members of the French Academy examined the stones, "It can't be--stones don't fall from the sky," or words to that effect. "These are common rocks that have been struck by lightning." Today we know that the "stones from the sky" were meteorites. Not more than fifty years ago Dr. Simon Newcomb, a world-famous astronomer and the first American since Benjamin Franklin to be made an associate of the Institute of France, the hierarchy of the world science, said, "It can't be." Then he went on to explain that flight without gas bags would require the discovery of some new material or a new force in nature. And at the same time Rear Admiral George W. Melville, then Chief Engineer for the U.S. Navy, said that attempts to fly heavier-than- air vehicles was absurd. Just a little over ten years ago there was another "it can't be." Ex- President Harry S. Truman recalls in the first volume of the Truman _Memoirs_ what Admiral William D. Leahy, then Chief of Staff to the President, had to say about the atomic bomb. "That is the biggest fool thing we have ever done," he is quoted as saying. "The bomb will never go off, and I speak as an expert in explosives." Personally, I don't believe that "it can't be." I wouldn't class myself as a "believer," exactly, because I've seen too many UFO reports that first appeared to be unexplainable fall to pieces when they were thoroughly investigated. But every time I begin to get skeptical I think of the other reports, the many reports made by experienced pilots and radar operators, scientists, and other people who know what they're looking at. These reports were thoroughly investigated and they are still unknowns. Of these reports, the radar- visual sightings are the most convincing. When a ground radar picks up a UFO target and a ground observer sees a light where the radar target is located, then a jet interceptor is scrambled to intercept the UFO and the pilot also sees the light and gets a radar lock-on only to have the UFO almost impudently outdistance him, there is no simple answer. We have no aircraft on this earth that can at will so handily outdistance our latest jets. The Air Force is still actively engaged in investigating UFO reports, although during the past six months there have been definite indications that there is a movement afoot to get Project Blue Book to swing back to the old Project Grudge philosophy of analyzing UFO reports--write them all off, regardless. But good UFO reports cannot be written off with such answers as fatigued pilots seeing a balloon or star; "green" radar operators with _only_ fifteen years' experience watching temperature inversion caused blips on their radarscopes; or "a mild form of mass hysteria or war nerves." Using answers like these, or similar ones, to explain the UFO reports is an expedient method of getting the percentage of unknowns down to zero, but it is no more valid than turning the hands of a clock ahead to make time pass faster. Twice before the riddle of the UFO has been "solved," only to have the reports increase in both quantity and quality. I wouldn't want to hazard a guess as to what the final outcome of the UFO investigation will be, but I am sure that within a few years there will be a proven answer. The earth satellite program, which was recently announced, research progress in the fields of electronics, nuclear physics, astronomy, and a dozen other branches of the sciences will furnish data that will be useful to the UFO investigators. Methods of investigating and analyzing UFO reports have improved a hundredfold since 1947 and they are continuing to be improved by the diligent work of Captain Charles Hardin, the present chief of Project Blue Book, his staff, and the 4602nd Air Intelligence Squadron. Slowly but surely these people are working closer to the answer--closer to the proof. Maybe the final proven answer will be that all of the UFO's that have been reported are merely misidentified known objects. Or maybe the many pilots, radar specialists, generals, industrialists, scientists, and the man on the street who have told me, "I wouldn't have believed it either if I hadn't seen it myself," knew what they were talking about. Maybe the earth is being visited by interplanetary spaceships. Only time will tell. CHAPTER EIGHTEEN And They're Still Flying [Transcriber's Note: The following three chapters were added to the second edition text in 1960.] Four years have passed since the first seventeen chapters of this book were written. During this period hundreds of unidentified flying objects have been seen and reported to the Air Force. Pilots, with thousands of hours of flying time are still reporting them; radar operators, experts in their field, are still tracking them; and crews on the missile test ranges are photographing them. UFO's are not just a fad. The Air Force's Project Blue Book is still very active. Not a week passes that one of the many teams of its nation wide investigation net is not in the field investigating a new UFO report. To pick up the history of the UFO the best place to start is Cincinnati, Ohio, in the late summer of 1955. For some unknown reason, one of those mysterious factors of the UFO, reports from this Hamilton County city suddenly began to pick up. Mass hysteria, the old crutch, wasn't a factor because neither the press, the radio nor TV was even mentioning the words "flying saucer." The reports weren't much in terms of quality. Some lady would see a "bobbing white light"; or a man, putting his car away, would see a "star jump." These reports, usually passed on to the Air Force through the Air Defense Command's Ground Observer Corps, merely went on the UFO plotting board as a statistic. But before long, in a matter of a week or two, the mass of reports began to draw some official attention because the Ground Observer Corps spotters themselves began to make UFO reports. At times during the middle of August the telephone lines from the GOC observation posts in Hamilton County (greater Cincinnati) to the filter center in Columbus would be jammed. Now, even the most cynical Air Force types were be-grudgingly raising their eyebrows. These GOC observers were about as close to "experts" as you can get. Many had spent hundreds of hours scanning the skies since the GOC went into the operation in 1952 to close the gaps in our radar net. Many held awards for meritorious service. They weren't crackpots. But still the cynics held out. This was really nothing new. The Project Blue Book files were full of similar incidents. In 1947 there had been a rash of reports from the Pacific Northwest; in 1948 there had been a similar outbreak at Edwards Air Force Base, the supersecret test center in the Mojave Desert of California; in 1949 the sightings centered in the midwest. None had panned out to be anything. Then came the clincher. On the night of August 23rd, shortly before midnight, reports of a UFO began to come in from the Mt. Healthy GOC observation post northwest of Cincinnati. Almost simultaneously, Air Defense Command radar picked up a target in that area. A minute or two later the Forestville and Loveland GOC posts, also in Hamilton County, made sightings. Now, three UFO's, described as brilliant white spheres, swinging in a pendulum-like motion, were on the ADC plotting boards- confirmed by radar. All pretext of ignoring the UFO's was dropped and at 11:58P.M., F-84's of the Ohio Air National Guard were scrambled. They were over Cincinnati at 12:10A.M. and made contact. Boring in at 20,000 feet, at 100% power, they closed but the UFO's left them as if they were standing still. The battle in the Cincinnati sector was on. Almost every night more UFO's were reported by the GOC. Attempts were made to scramble interceptors but there were no more radar contacts and a jet interceptor without ground guidance is worthless. At the height of this activity it was decided that more information was needed by the Air Defense Command. Maybe from a mass of data something, some kind of clue, could be sifted out. The answer: establish a special UFO reporting post. The man to operate this post was tailor-made. On September 9, Major Hugh McKenzie of the Columbus Filter Center contacted Leonard H. Stringfield in Cincinnati. Stringfield, besides being a very public minded citizen, was also known as a level-headed "saucer expert." Sooner or later, usually sooner, he heard about every UFO sighting in Hamilton County. He was given a code, "Foxtrot Kilo 3-0 Blue," which provided him with an open telephone line to the ADC Filter Center in Columbus. He was in business but he didn't have to build up a clientele--it was there. For the next few months Stringfield did yeoman duty as Cincinnati's one-man UFO center by sifting out the wheat from the chaff and passing the wheat on to the Air Force. As he told me the other day, half his nights were spent in his backyard clad in shorts and binoculars. Fortunately his neighbors were broad-minded and the UFO's picked relatively warm nights to appear. Most of the reports Stringfield received were duds. He lost track of the number. The green, red, blue, gold and white; discs, triangles, squares and footballs which hovered, streaked, zigzagged and jerked, turned out to be Venus, Jupiter, Arcturus and an occasional jet. A fiery orange satellite which hovered for hours turned out to be the North Star viewed through a cheap telescope, and the "whole formation of space ships" were the Pleiades. Then it happened again. On the evening of March 23rd Stringfield's telephone rang. It was Charles Deininger at the Mt. Healthy GOC post. They had a UFO in sight off to the east. Could Stringfield see it? He grabbed his extension phone and ran outdoors. There, off to the east, were two, large, low flying lights. One of the lights was a glowing green and the other yellow. They were moving north. "Airplane!" This was Stringfield's first reaction but during World War II he had made the long trek up the Pacific with the famous Fifth Air Force and he immediately realized that if it was an airplane it would have to be very close because of the large distance between the lights. And, as a clincher, no sound came through the still night. He dialed the long distance operator and said the magic words, "This is Foxtrot Kilo Three Dash Zero Blue." Seconds later he was talking to the duty sergeant at the Columbus Filter Center. A few more seconds and the sergeant had his story. Another jet was scrambled and this time Stringfield, via a radiotelephone hookup to the airplane, gave the pilot a vector. Stringfield heard the jet closing in but since it was a one-way circuit he couldn't hear the pilot's comments. Once again the UFO took off. This was a fitting climax for the Cincinnati flap. As suddenly as it began it quit and from the mass of data that was collected the Air Force got zero information. In the mystery league the UFO's were still ahead. Although the majority of the UFO activity during the last half of 1955 and early 1956 centered in the Cincinnati area there were other good reports. Near Banning, California, on November 25, 1955, Gene Miller, manager of the Banning Municipal Airport and Dr. Leslie Ward, a physician, were paced by a "globe of white light which suddenly backed up in midair," while in Miller's airplane. It was the same old story: Miller was an experienced pilot, a former Air Force instructor and air freight pilot with several thousand hours flying time. Commercial pilots came in for more than their share of the sightings in 1956. On January 22, UFO investigators talked to the crew of a Pan American airliner. That night, at 8:30P.M., the Houston to Miami DC- 7B had been "abeam" of New Orleans, out over the Gulf of Mexico. There was a partial moon shining through small wisps of high cirrus clouds but generally it was a clear night. The captain of the flight was back in the cabin chatting with the passengers; the co-pilot and engineer were alone on the flight deck. The engineer had moved up from his control panel and was sitting beside the co-pilot. At 8:30 it was time for a radio position report and the co-pilot, Tom Tompkins, leaned down to set up a new frequency on the radio controls. Robert Mueller, the engineer, was on watch for other aircraft. It was ten, maybe twenty seconds after Tompkins leaned down that Mueller just barely perceived a pinpoint of moving light off to his right. Even before his thought processes could tell him it might be another airplane the light began to grow in size. Within a short six seconds it streaked across the nose of the airliner, coming out of the Gulf and disappearing inland over Mississippi or Alabama. Tompkins, the co-pilot, never saw it because Mueller was too astounded to even utter a sound. But Mueller had a good look. The body of the object was shaped like a bullet and gave off a "pale, luminescent blue glow." The stubby tail, or exhaust, was marked by "spurts of yellow flame or light." The size? Mueller, like any experienced observer, had no idea since he didn't know how far away it was. But, it was big! One sentence, dangling at the bottom of the report was one I'd seen many, many times before: "Mr. Mueller _was_ a complete skeptic regarding UFO reports." During 1956 there was a rumor--I heard it many times--that the Air Force had entered into a grand conspiracy with the U.S. news media to "stamp out the UFO." The common people of the world, the rumor had it, were not yet psychologically conditioned to learn that we had been visited by superior beings. By not ever mentioning the words "unidentified flying object" the public would forget and go on their merry, stupid way. I heard this rumor so often, in fact, that I began to wonder myself. But a few dollars invested in Martinis for old buddies in the Kittyhawk Room of the Biltmore Hotel in Dayton, or the Men's bar in the Statler Hotel in Washington, produces a lot of straight and reliable information--much better than you get through official channels. There was no "silence" order I learned, only the same old routine. If the files at ATIC were opened to the public it would take a staff of a dozen people to handle all the inquiries. Secondly, many of the inquiries come from saucer screwballs and these people are like a hypochondriac at the doctor's; nothing will make them believe the diagnosis unless it is what they came in to hear. And there are plenty of saucer screwballs. One officer summed it up neatly when he told me, "It isn't the UFO's that give us the trouble, it's the people." As a double check I called several newspaper editors the other day and asked, "Why don't you print more UFO stories?" The answers were simple, it's the old "dog bites man" bit--ninety-nine per cent have no news value any more. On May 10, 1956, the man bit the dog. A string of UFO sightings in Pueblo, Colorado, hit the front pages of newspapers across the United States. Starting on the night of May 5th, for six nights, the citizens of Pueblo, including the Ground Observer Corps, saw UFO's zip over their community. As usual there were various descriptions but everyone agreed "they'd never seen anything like it before." On the sixth night, the Air Force sent in an investigator and he saw them. Between the hours of 9:00P.M. and midnight he saw six groups of triangular shaped objects that glowed "with a dull fluorescence, faint but bright enough to see." They passed from horizon to horizon in six seconds. The next day this investigator was called back to Colorado Springs, his base, and a fresh team was sent to Pueblo. The man _really_ chomped down on the dog in July and the UFO _really_ made headlines. Maybe it was because a fellow newspaper editor was involved, along with the Kansas Highway Patrol, the Navy and the Air Force. Or, maybe it was simply because it was a good UFO sighting. About the time Miss Iowa was being judged Miss USA in the 1956 Miss Universe Pageant at Long Beach, the city editor of _Arkansas_ _City_ _Daily_ _Traveler_, and a trooper of the Kansas State Highway Patrol were sitting in a patrol cruiser in Arkansas City. It was a hot and muggy night. Occasionally the radio in the cruiser would come to life. An accident near Salina. A drunk driving south from Topeka. Another accident near Wichita. But generally South Central Kansas was dead. The newspaper editor was about ready to go home--it was 10 o'clock--when the small talk he and the trooper had been making was brought to an abrupt finale by three high pitched beeps from the cruiser's radio. An important "all cars bulletin" was coming. Twenty- five years as a newspaperman had trained the editor to always be on the alert for a story so he reached down and turned up the volume. Within seconds he had his story. "The Hutchinson Naval Air Station is picking up an unidentified target on their radar," the voice of the dispatcher said, with as much of an excited tone as a police dispatcher can have. "Take a look." Then the dispatcher went on to say that the target was moving in a semi-circular area that reached out from 50 to 75 miles east of Hutchinson. A B-47 from McConnell AFB at Wichita was in the area, searching. The last fix on the object showed it to be near Emporia, in Marion County. The two men in the patrol cruiser looked at each other for a second or two. Like all newspaper editors, this man had had his bellyful of flying saucer reports--but this was a little different. "Let's go out and look," he said, fully doubting that they would see anything. They drove to a hill in the north part of the city where they could get a good view of the sky and parked. In a few minutes an Arkansas City police car joined them. It was a clear night except for a few wispy clouds scattered across the north sky. They waited, they looked and they saw. Shortly before midnight, off to the north, appeared "a brilliantly lighted, teardrop shaped, blob of light." "Prongs, or streams of bright light, sprayed downward from the blob toward the earth." It was big, about the size of a 200 watt light bulb. As the group of men silently watched, the weird light continued to drift and for many minutes it moved vertically and horizontally over a wide area of the sky. Then it faded away. As one of the men later told me, "I was glad to see it go; I was pooped." The next morning literally hundreds of people spent hours conjecturing and describing. After all these years of talk they'd actually seen one. Several photos, showing the big blob of light, were shown around, and two fishermen readily admitted they'd packed up their poles and tackle boxes and headed home when they saw it. Editor Coyne summed up the feeling of hundreds of Kansans when he said: "I have tended to discount the stories about flying objects, but, brother, I am now a believer." What was it? First of all it was confusion. Early the next morning Air Force investigators flooded the area asking _the_ questions: "What size was it in comparison to a key or a dime?" "Would it compare in size to a light bulb?" "Was there any noise?" As soon as they left, the military tersely announced that no radar had picked up any target and no B-47's had been sent out. Then they pulled the plugs on the incoming phone lines. The confusion mounted when newsmen tapped their private sources and learned that a B-47 _had_ been sent into the area. A few days later the Air Force told the Kansans what they'd seen: The reflection from burning waste gas torches in a local oil field. This was greeted with the Kansan version of the Bronx Cheer. Nineteen hundred fifty-six was a big year for Project Blue Book. According to an old friend, Captain George Gregory, who was then Chief of Blue Book, they received 778 reports. And through a lot of sleepless nights they were able to "solve" 97.8% of them. Only 17 remained "unknowns." Digging through the reports for 1956, outside of the ones already mentioned, there were few real good ones. In Banning, California, Ground Observer Corps spotters watched a "balloon-like object make three rectangular circuits around the town." In Plymouth, New Hampshire, two GOC spotters reported "a bright yellow object which left a trail, similar to a jet, moving slowly at a very high altitude." At Rosebury, Oregon, State Police received many reports of "funny green and red lights" moving slowly around a television transmitter tower. And in Hartford, Connecticut, two amateur astronomers, looking at Saturn through a 4-inch telescope, were distracted by a bright light. Turning their telescope on it they observed a "large, whitish yellow light, shaped like a ten gallon hat." Many other people evidently saw the same UFO because the local newspaper said, "reports have been pouring in." In Miami, a Pan American Airlines radar operator tracked a UFO at speeds up to 4000 miles an hour. Five of his skeptical fellow radar operators watched and were confirmed. At Moneymore, Northern Ireland, a "level-headed and God fearing" citizen and his wife captured an 18-inch saucer by putting a headlock on it. They started to the local police station, but put the saucer down to climb over a hedge, and it went whirling off to the hinterlands of space. The 27th Air Defense Division that guards the vast aircraft and missile centers of Southern California was alerted on the night of September 9. In rapid succession, a Western Airlines pilot making an approach to Los Angeles International Airport, the Ground Observer Corps, and numerous Los Angeles citizens called in a white light moving slowly across the Los Angeles basin. When the big defense radars on San Clemente Island picked up an unknown target in the same area that the light was being reported two F-89 jet interceptors were scrambled but saw nothing. A few days later investigators learned that a $27.65 weather balloon had caused the many thousand dollars' worth of excitement. The matter of scrambling interceptors has been a sore point with the UFO business for a long time. Many people believe that the mere fact the Air Force will send up two, three, or even four aircraft that cost $2000 an hour to fly is proof positive that the Air Force doesn't believe its own story that UFO's don't exist. The official answer you'll get, if you ask the Air Force, is that they scramble against _any_ unknown target as a matter of defense. But over coffee you get a different answer. They write the UFO scrambles off as training cost. Each pilot has to get so much flying time and simulating intercepts against an unidentified light is more interesting than merely "burning holes in the air." If appropriations are ever cut to the point where training must be curtailed, and Heaven forbid, there will be no more scrambles after flying saucers. And the colonel who told me this was emphatic. The year 1957 was heralded in by a startling announcement which ended a long dry spell of UFO news. At a press conference in Washington, D.C., Retired Admiral Delmer S. Fahrney made a statement. Newspapers across the country carried it complete, or in part, and people read the statement with interest because Admiral Fahrney is well known as a sensible and knowledgeable man. He had fought for and built up the Navy's guided missile program back in the days when people who talked of ballistic missiles and satellites _had_ to fight for their beliefs. First, Admiral Fahrney announced that a non-profit organization, the National Investigations Committee On Aerial Phenomena (NICAP) had been established to investigate UFO reports. He would be chairman of the board of governors and his board would consist of such potent names as: Retired Vice Admiral R. H. Hillenkoetter, for two years the director of the supersecret Central Intelligence Agency. Retired Lieutenant General P. A. del Valle, ex-commanding general of the famous First Marine Division. Retired Rear Admiral Herbert B. Knowles, noted submariner of World War II. Then Admiral Fahrney read a statement regarding the policies of NICAP. It was as follows: "Reliable reports indicate that there are objects coming into our atmosphere at very high speeds . . . No agency in this country or Russia is able to duplicate at this time the speeds and accelerations which radars and observers indicate these flying objects are able to achieve. "There are signs that an intelligence directs these objects because of the way they fly. The way they change position in formations would indicate that their motion is directed. The Air Force is collecting factual data on which to base an opinion, but time is required to sift and correlate the material. "As long as such unidentified objects continue to navigate through the earth's atmosphere, there is an urgent need to know the facts. Many observers have ceased to report their findings to the Air Force because of the seeming frustration--that is, all information going in, and none coming out. It is in this area that NICAP may find its greatest mission. "We are in a position to screen independently all UFO information coming in from our filter groups. "General Albert C. Wedemeyer will serve the Committee as Evaluations Adviser and complete analyses will be arranged through leading scientists. After careful evaluation, we shall release our findings to the public." Donald Keyhoe, a retired Marine Corps Major, and author of three top seller UFO books, was appointed director. The mere fact that another civilian UFO investigative group was being born was neither news nor UFO history because since 1947 well over a hundred such organizations had been formed. Many still exist; many flopped. But none deserve the niche in UFO history that does NICAP. NICAP had power and it raised a storm that took months to calm down. NICAP got off to a fast start. Dues were pegged at $7.50 a year, which included a subscription to the very interesting magazine _The_ _UFO_ _Investigator_, and the operation went into high gear. With such names as Fahrney, Wedemeyer, Hillenkoetter, Del Valle and Knowles for prestige, and Keyhoe for intrigue, saucer fans all over the United States packaged up their seven-fifty and mailed it to headquarters. Each, in turn, became a "listening post" and an "investigator." Keyhoe set up a Panel of Special Advisors, all saucer fans, to "impartially evaluate" the UFO reports ferreted out by the "listening posts," based on facts uncovered by the "investigators." Even though the "leading scientists" Fahrney mentioned in his statement never materialized NICAP was cocked, primed, and ready. To get things off to a gala start Keyhoe, as director of NICAP, wrote to the Air Force and set out NICAP's Eight Point Plan. In essence this plan suggested (some say demanded) that the Air Force let NICAP ride herd on Project Blue Book. First of all, NICAP wanted its Panel of Special Advisors to review and concur with all of the conclusions on the thousands of UFO reports that the Air Force had in its files. This went over like a worm in the punch bowl. First of all, the Air Force didn't feel it was necessary to review its files. Secondly, they knew NICAP. If every balloon, planet, airplane, and bird that caused a UFO report hadn't been captured and a signed confession wrung out, the UFO would be a visitor from outer space. The Air Force decided to ignore NICAP. But NICAP wouldn't be ignored. They bombarded everyone from the Secretary of the Air Force on down with telephone calls, telegrams and letters. Still the Air Force remained silent. Then NICAP headquarters called in the troops and members from all corners of the nation cut loose. The barrage of mail broke the log jam and just enough information to constitute an answer dribbled out of the Office of the Secretary of the Air Force. But this didn't satisfy Keyhoe or his UFO hungry NICAPions. They wanted blood and that blood had to taste like spaceships or they wouldn't be happy. The cudgel they picked up next was powerful. The Air Force had said that there was nothing classified about Project Blue Book yet NICAP hadn't seen every blessed scrap of paper in the Air Force UFO files. This was unwarranted censorship! While Congress was right in the middle of such important and crucial problems as foreign policy, atomic disarmament, racketeering, integration and a dozen and one other problems, NICAP began to bedevil every senator and representative who was polite enough to listen. It's the squeaky wheel that gets the grease and in November 1957, the United States Senate Committee on Government Operations began an inquiry concerning UFO's. I gave my testimony and so did others who had been associated with Project Blue Book. A few weeks later the inquiry was dropped. But NICAP had made its name. Of all of the thorns that have been pounded into the UFO side of the Air Force, NICAP drove theirs the deepest. In the midst of all this mess Admiral Fahrney, General Wedemeyer and General del Valle, politely, and quietly, resigned from NICAP's board of governors. Neither the loss of these famous names nor the defeat at the hands of the Air Force has stopped NICAP. They continue to forge ahead, undaunted. In many UFO incidents they have actually uncovered additional, and sometimes interesting, information. NICAP Director Don Keyhoe has taken a beating, being accused of profiteering, trying to make headlines, and other minor social crimes. But personally I doubt this. Keyhoe is simply convinced that UFO's are from outer space and he's a dedicated man. While the big NICAP-Air Force battle was going on the UFO's were not waiting to see who won. They were still flying. At Ellington AFB, Texas, a Ground Observer Corps team spotted a UFO and passed it on to a radar crew. Although the radar crew couldn't pick it up on their sets they saw it visually. The lieutenant in charge told investigators how it crossed from horizon to horizon in 45 seconds. On March 9, several passengers on a New York to San Juan, Porto Rico airliner were injured when the pilot pulled the big DC-6 up sharply to miss a "large, greenish white, clearly circular-shaped object" which was on a collision course with the plane. The pilots of several other airliners in the same airway confirmed the sighting. Two weeks later jet interceptors were scrambled over Los Angeles to look for a UFO. According to the records, the first report of the brilliant and mysterious, flashing, red light came from a man in the east part of Pasadena. But his report was quickly lost in the shuffle as more and more calls began to come in. As the flashing light crossed the Los Angeles Basin from southeast to northwest hundreds of people saw it. Traffic was tied up on the Rose Parade famous Colorado Boulevard as drivers stopped their cars to get out and look. As it neared the Air Defense Command Filter Center in Pasadena the filter center personnel, those that could be spared, went out and looked. They saw it. Police switchboards lit up a solid red as it crossed the San Gabriel Valley. Near midnight a CAA radar picked up unidentified targets near the Oxnard AFB, at Oxnard, California (northwest of Los Angeles), and at almost that identical time people on the airbase saw the light This did it, and two powerful jets, equipped with all weather radar, came screaming into the area. But it was the same old story--no contact--the UFO was gone. The midwest was visited on the morning of May 23rd, when five observers in Kansas City saw four silver, disc-shaped objects flying in formation at extremely high speed. At one point during their flight two of the objects broke formation and veered off but soon rejoined. It took the objects only four minutes to cross the sky. There were other reports during the first half of 1957, 250 of them to be exact, and many could be classified as "good." But they were nothing compared to those that were to come. On November 3, 1957, a rash of sightings broke out in Texas and they had a brand new twist. To do things up right the powers that guide the UFO picked the town of Levelland only 27 miles west of Lubbock, the home of the now traditional "Lubbock Lights." It was with a tug of nostalgia that I read about these reports because five years before, almost to the day, Lubbock had plunged the Air Force, and me, into the UFO mystery on a grand scale. According to the best interpretation of the maze of conflicting stories, facts and rumors about these famous sightings the only positive fact is that there were scattered storm clouds across West Texas on the night of November 4, 1957. This was unusual for November and everyone in the community was just a little edgy. It was early in the evening, at least early for West Texas on a Saturday night, when Pedro Saucedo, a farm worker, and his friend Joe Salaz, started out in Saucedo's truck toward Pettit, ten miles northwest of Level-land. They had just turned off State Highway 116 and were heading north on a country road when the two men saw a flash of light in an adjacent field. Saucedo, a Korean War Veteran, and Salaz didn't pay much attention to the light at first. They only noticed that it was coming closer. "It seemed to be paralleling us and edging a little closer all the time," Saucedo later recalled. Still neither man paid any attention to the light. They drove on, Saucedo watching the road and Salaz talking. Then it hit. The first signal of something wrong was when the truck's headlights went out; then the engine stopped. Before Saucedo could hit the starter again he glanced over his left shoulder. A huge ball of fire was "rapidly drifting" toward the truck. Without a second's hesitation Saucedo did what the Korean War had taught him to do when in doubt, he shoved open the car door and hit the dirt. Salaz just sat. "The 'Thing' passed directly over my truck with a great sound and rush of wind," Saucedo later told County Sheriff Weir Clem, after he'd started his truck and had driven back to Levelland. "It sounded like thunder and my truck rocked from the blast. I felt a lot of heat." The "Thing," which disappeared across the prairie, looked like a "fiery tornado." Five years before and a little east of where Saucedo and Salaz were "buzzed" I had talked to two women who described almost an identical UFO. And it remains "unknown" to this day. In Levelland, the two men's story would have been enough to keep Sheriff Clem busy for the rest of the night but between the hours of 8:15P.M. and midnight on the 2nd the "Levelland Thing" struck five more times. James D. Long, a Waco truck driver, came upon "it" four miles west of Levelland and fainted as it roared over his truck. Ronald Martin, another truck driver, was stopped east of Levelland, as was Newell Wright, a Texas Tech student. Jim Wheeler, Jose Alvarez and Frank Williams added their stories to the melee. All of those who had been attacked told Sheriff Clem a similar story: "The 'Thing' was shaped something like an egg standing on end. It was fiery red, more like a red neon light. It was about 200 feet long and was about 200 feet in the air. When it came close to cars the engines would stop and the lights would go out." "Everyone," Sheriff Clem said, "seemed very excited." That night everyone in West Texas saw UFO's. Sheriff Clem saw a brilliant light in the distance. Highway patrolmen Lee Hargrove and Floyd Cavin reported similar brilliant lights at the same time but from a different location. The control tower operators at the Amarillo Airport, to the north, saw a "blue, gaseous object which moved swiftly and left an amber trail." There were dozens more. It was a memorable Saturday night in Levelland. But unbeknown to Sheriff Clem or the residents of West Texas, they weren't alone on the visitor's list. At 2:30A.M. on Sunday morning, only a few hours after the "Thing" raised havoc around Levelland, an army military police patrol was cruising the supersecret White Sands Proving Ground in New Mexico. Here is their report as they gave it to Air Force UFO investigators: "At approximately 0230, 3 November 1957, Source, together with PFC ------, were on a routine patrol of the up range area of the White Sands Proving Ground when Source noticed a 'very bright' object high in the sky. This object slowly descended to an altitude estimated to be approximately 50 yards where it remained motionless for about 3 minutes, then it descended to the ground where the light went out. The object was not blurred or fuzzy, emitted no vapor or smoke. The object was in view for about 10 minutes, and Source estimated that it was approximately 2 or 3 miles away. It was estimated to be between 75 and 100 yards in diameter and shaped like an egg. Source stated that it was as large as a grapefruit held at arm's length. The weather was cold, drizzling and windy, and Source stated no stars were visible. After the light went out Source and PFC ------ continued north to the STALLION SITE CAMP and reported the incident to the Sergeant of the Guard who returned to the area but failed to find anything." The flap was on. On Monday, the 4th, the "Levelland Thing" struck again near the White Sands Proving Ground. James Stokes, a 20-year Navy veteran, and an electronics engineer, had the engine of his new Mercury stopped as "a brilliant, egg-shaped" object made a pass at the highway. As it went over, Stokes said, "it felt like the radiation of a giant sun lamp." Stokes said there were ten other carloads of people stopped but if this is true no one ever found out who they were. The Air Force wrote off Stokes' story as, "Hoax, presumably suggested by the Levelland, Texas, reports." Maybe the Air Force didn't believe James Stokes but when the Coast Guard Cutter _Seabago_ radioed in their report from the Gulf of Mexico wheels began to turn--fast. On Tuesday morning, the 5th, the _Seabago_ was about 200 miles south of the mouth of the Mississippi River on a northerly heading. At 5:10A.M. her radar picked up a target off to the left at a distance of about 14 miles. This was really nothing unusual because they were under heavily traveled air lanes. The early morning watch is always rough and as the small group of officers and men in the Combat Information Center quietly watched the target, with a noticeable lack of enthusiasm, it moved south, made a turn, and headed back to the north again. A few of the men noticed that the turn looked "a little different," but this early in the morning they didn't give it much thought. At 5:14 the target went off the scope to the north. At 5:16 it was back and the lassitude was instantly gone. Now the target was 22 miles _south_ of the ship. No one in the CIC had to draw a picture. Something, in two minutes, had disappeared off the scope to the north, made a big swing around the ship, out of radar range, and had swung in from the south! Word went up to the lookouts. They tensed up and began to scan the sky. The radar contacts continued. This second contact, south of the ship, was held for two full minutes as the target moved out from 22 to 55 miles. Then it faded. At 5:20 the target was back but now it was _north_ of the ship again, and it was hovering! Again the lookouts were called. Could they see anything now? Their "No" answers didn't hold for long because seconds later their terse reports began to come into the CIC. A "brilliant light, like a planet" was streaking across the northwest sky about 30 degrees above the horizon. Unfortunately the radar had lost contact for a moment when the visual report came in. At 5:37 the target disappeared from the scopes and was gone for good. The _Seabago_ Case was ended but the UFO's continued to fly. Reports continued to come into the Air Force and a lot of investigators lost a lot of sleep. The next day at 3:50P.M. the C.O. of an Air Force weather detachment at Long Beach, California, and twelve airmen watched six saucer- shaped UFO's streak along _under_ the bases of a 7000 foot high cloud deck. On the same day, also in Long Beach, officers and men at the Los Alamitos Naval Air Station saw UFO's almost continuously between the hours of 6:05 and 7:25P.M. Long Beach police reported "well over a hundred calls" during this same period. During November and December of 1957 it was a situation of you name the city and there was a UFO report from there. Trying to sift them out and put them in a book would be like sorting out a plateful of spaghetti. And if you succeeded you would have a document the size of the New York City telephone directory. Most of the reports were explained. The Levelland, Texas, sightings were written off as "St. Elmo's Fire." The military police at the White Sands Proving Ground saw the moon through broken clouds and the crew of the Coast Guard ship _Seabago_ were actually tracking several separate aircraft. The 1957 flap was as great as the previous record breaking 1952 flap. During 1957 the Air Force received 1178 UFO reports. Of these, only 20 were placed on the "unknown" list. In comparison to 1957, the first months of 1958 were a doldrums. Reports drifted in at a leisurely pace and the Air Force UFO investigating teams, blooded during the avalanche of 1957, picked off solutions like knocking off clay pipes in a shooting gallery. In Los Angeles, a few clear nights drove the Air Defense Command nuts. People could actually see the sky and the sight of so many stars frightened them. Unusual atmospherics in Georgia made stars jump and radars go crazy; and a balloon, hanging over Chicago at dusk, cost the taxpayers another several thousand dollars but the pilots made their flight pay. A statement by Dr. Carl Jung, renowned Swiss psychologist, was widely publicized in July 1958. Dr. Jung was quoted as saying, in a letter to a U.S. saucer club, "UFO's are real." When Dr. Jung read what he was supposed to have written the Alps rang with screams of "misquote." No one got excited until the early morning of September 29th. Shortly before dawn on that day a confusing mess of reports began to pour into the Air Force. Some came from the Washington, D.C., area. People right in NICAP's backyard told of seeing a "large, round, fiery object" shoot across the sky from southeast to northwest. A few excited observers, all from the country northwest of Washington, "had seen it land" and even as they telephoned in their reports they could see it glowing behind a neighbor's barn. Other reports, also of a "huge, round, fiery object," came in from such places as Pittsburgh, Somerset, and Bedford, all in Pennsylvania; and Hagerstown and Frederick in Maryland. To add to the confusion, people in Pennsylvania reported seeing three objects "flying in formation." When the dust settled Air Force investigators took the first step in the solution of any UFO report. They plotted the sightings on a map, and collated the directions of flight, descriptions and times of observation. It was obvious that the object had moved along a line between Washington, D.C., and Pittsburgh. It was traveling about 7000 miles an hour and everyone had obviously seen the same object. By the time it had passed into Pennsylvania it had split into three objects. But the hooker was the reported landings northeast of Washington. Too many people had reported a glow on the ground to write this factor off even though an investigator, dispatched to the scene shortly after dawn, had found nothing in the way of evidence. One possibility was that some unknown object had streaked across the sky, landed and then took off again. Could be, but it wasn't. The next night the case broke. The glow from the landing was a bright floodlight on a barn. No one had ever really noticed it before until the object passed nearby. A few days later the object itself was identified. From the many identical descriptions Project Blue Book's astrophysicist pinned it down as a large meteor. The meteor had broken up near the end of its flight to produce the illusion of three objects flying in formation. Of all the 590 UFO reports the Air Force received in 1958, probably the weirdest was solved before it was ever reported. About four o'clock on the afternoon of October 2, 1958, three men were standing in a group, talking, outside a tungsten mill at Danby, California, right in the heart of the Mojave Desert The men had been talking for about five minutes when one of them, who happened to be facing the northwest, stopped right in the middle of a sentence and pointed. The other two men looked and to their astonishment saw a brilliant glow of light. It was so close to the horizon that it was difficult to tell if it was on the horizon or in the air just above it. At first the men ignored the light but as it persisted they became more interested. They'd all heard "flying saucer" stories and, they later admitted, this possibility entered their minds. As they watched they speculated. It could be something natural but all of them had been around this area for months and they'd never seen this light before. About the time they decided to get a telescope and take a closer look the light suddenly faded. All the next day the men kept glancing off toward the northwest as they worked but the clear blue sky was blank. Then, at 4:00P.M., the light was back. This time they had a telescope. All the men took turns looking at the object and all agreed that it was about 15 feet long, 5 feet high and solid. It looked like the sun reflecting off shiny metal. It was about four miles away, they estimated, and almost exactly on the horizon. Now the men's curiosity was thoroughly whetted. Martian spaceship or whatever, they were going after it. But a several-hour search of the area produced nothing. And, as soon as they left the mill they lost sight of the object. Darkness brought the search to a halt. The next day at 4:00P.M. a crowd had gathered and the UFO kept its appointment. Again the men studied the object and tension ran high. Someone had resurrected the stories of UFO's landing in the desert. At the time they'd sounded absurd but now, standing there looking at a UFO, it was different. A party of men were all ready to jeep out into the desert to make another search when one of them made a discovery. There were guy wires coming out of the UFO and running down into the trees. Other people looked. And then the solution hit like a fireball. Exactly in line with the UFO, and ten miles away, not four, was a set of antennas for the California State Highway Patrol radio. The sun's rays were reflecting from these antennas. They'd never seen this before because on only a few days during the year was the sun at exactly the right angle to produce the reflection. The men were right. In a few days the Danby UFO left and it never came back. Nineteen hundred fifty-eight was not a record year for UFO's. The 590 reports received didn't stack up to the 1178 for 1957, or the 778 for 1956, or the 918 for 1952. But a new record was set when the percentage of unknowns was pared down to a new low. During 1958 only 9/10 of one per cent of the reports, or 5 reports, were classified as "unknown." More manpower, better techniques, and just plain old experience has allowed the Air Force to continually lower the percentage of "unknowns" from 20%, while I was in charge of Project Blue Book, to less than 1%, today. No story of the UFO would be complete without describing one of these unknowns, so here's one exactly as it came out of the Project Blue Book files: "On 31 October 1958, this Center received a TWX reporting an UFO near Lock Raven Dam. A request for a detailed investigation was sent to the nearest Air Force Base. The following is a summary of the incident and subsequent investigation: "Two civilians were driving around near Lock Raven Dam on the evening of 26 October 1958. When they rounded a curve about 200 to 300 yards from a bridge they saw what appeared to be a large, flat, egg shaped object hovering about 100 to 150 feet above the bridge superstructure. They slowed their car and when they got to within 75 or 80 feet of the bridge their engine quit and their lights went out. The driver immediately stepped on the brakes and stopped the car. Attempts were made to start the car and when this was unsuccessful they became frightened and got out of the car. They put the car between them and the object and watched for approximately 30 to 45 seconds. The object then seemed to flash a brilliant white light and both men felt heat on their faces. Then there was heard a loud noise and the object began rising vertically. The object became very bright while rising and its shape could not be seen as it rose. It disappeared in five to ten seconds. "After the object disappeared, the car was started and they turned it around and drove to where a phone was located and contacted the Towson Police Department. Two patrolmen were sent to meet them. The two men told the patrolmen of their experience. The witnesses then noticed a burning sensation on their faces and became concerned about possible radiation burns. They went to a Baltimore Hospital for an examination. Both witnesses were advised by the doctor that they had no reason for concern. "An extensive investigation was made concerning this incident. However, no valid conclusion could be made as to the possible nature of the sighting and it remains unidentified." So ended 1958 and in its final tally of sightings for the year Project Blue Book added a new space age touch--earth satellites had accounted for eleven UFO reports. Nineteen hundred fifty-nine came in with a good one. We used to call these reports "Ground-air-visual-radar" sightings and they make interesting reading. At Duluth, Minnesota, in March, it's dark by five o'clock in the evening. It's cold. The temperature hovers around zero and it's so clear you have a feeling you can almost reach up and touch the stars. It was this kind of a night on March 13, 1959, and as the officers and men of the Air Defense Command fighter squadron at the Duluth Municipal Airport moved, they shuffled along slowly because the heavy parkas and arctic clothing they wore were heavy. Then came the UFO report and things speeded up. At 5:20P.M., exactly, the operations officer noted the time, word came in over the comm line that someone had sighted an unidentified flying object off to the north. Word flashed around the squadron and as people rushed out of buildings to look they were joined by those already outside. And there it was: big, round and bright, and it was moving at high speed. Some observers thought it was "greenish," others "reddish," but it was something and it was there. The bearing was 300 degrees from the base. It was an awesome sight and it became even more awesome when a quick call to an adjacent radar site brought back the word that they had just picked up a target on a bearing of 300 degrees from the air base. They were tracking it and taking scope photos. In the alert hangar, the two pilots standing the alert had been listening to a running account of the sighting so when the scramble bell rang they took off for their airplanes like a couple of sprinters. As the two big alert hangar doors swung up the whining screech of the jet starters, followed by thunder of the engines, filled the airfield. The atmosphere around the Duluth Municipal Airport was closely akin to Santa Anita the instant the starting gates open. I've been around when jet interceptors scramble and you can twang the tension with your finger. As the people on the ground watched they could first see the flame of the jet's afterburner disappear into the night. Then the jet's navigation lights faded out on a bearing of 300 degrees. At the radar site they still had the target and there were many excited people watching the big pale, orange scopes as two little bright points of light began to close on a bigger blob of light. Then the pilots gave the "Tally-ho"--they were in visual contact. But the "Tally-ho" had no more been given than the big blob of light on the target began to pull away from the fighters and was soon off the scope. The pilots kept visual contact, though, and the radio provided the details of the chase to the now blind crew in the radar room. The two jets bored north, with afterburner on, and the needles on their machmeters passed the "1.0" mark. But still the UFO was just as far away as it had ever been. The chase went on for a few minutes more before the pilots pulled their throttles back into the cruise position, turned, and came home. Even before they landed, the people at the airbase saw the big, round and bright UFO rapidly begin to fade and then it was gone. So ended the glamour and the dog work began. Each man who had seen the UFO visually was carefully interrogated. Weather reports were collected. Radarscope photos were developed. The two pilots received special attention. The exact bearing of the UFO was measured and 300 degrees magnetic was correct. The bundle of data was packed up and sent to Project Blue Book. The panel of experts convened. First, the radarscope photos were examined. "Those targets could be interference from other radars," said the radar expert, and he mentally ticked off a dozen and one other similar cases of known interference. The weather data, and locations and frequencies of other radars were checked out. Beyond doubt it was interference from another radar that caused the target. Now, the visual sighting. Balloon? No, the fighters could have caught a balloon in seconds. Airplane? Same answer. These jets were the fastest things in the air. Planet or star? Out came the almanacs and the puzzle went to the astrophysicist. Venus was on a bearing of 300 degrees from the Duluth Municipal Airport at 5:20P.M. on March 23rd. _But_ Venus was just below the horizon at that time and the observers said the UFO was "moving fast." Once again the weather charts were studied. The atmospheric conditions were such that it was very possible that due to refraction Venus would have been visible just on the horizon. The fact that the UFO faded so fast would bear this out because the conditions for such refraction are critical and a slight change in atmospheric conditions could easily have caused the planet to disappear. The speed--a common illusion. Further interrogation of the observers showed it had never moved. So, the history of the UFO is almost brought up to date. CHAPTER NINETEEN Off They Go into the Wild Blue Yonder At 12:30P.M. on Thursday, November 20, 1952, history was made. At least, so says George Adamski, lecturer on philosophy and student of technical matters and astronomy. At 12:30P.M. on Thursday, November 20, 1952, George Adamski was the first man on earth to talk to a Venusian. At least, so says George Adamski. I was chief of Project Blue Book at the time and the name "Professor Adamski"--he had a title then--wasn't new to me. He, or some of his followers had been showering the Air Force with photos of flying saucers. Letters by the gross were coming in demanding recognition of the great professor and an analysis of his photos. We obliged and the photos were examined by the experts at Wright- Patterson Photo Reconnaissance Labs. The verdict came back: "They could be genuine, of course, but they also could have been easily faked by a ten year old with a Brownie camera." For a few weeks we forgot George Adamski. But then the press began to clamor at our gates. The news was leaking out of Southern California. George Adamski had talked to a Venusian! We held out for a long time but the pressure mounted and I headed for California to find out what it was all about. As far as George Adamski was concerned I was just another thirsty sight-seer from the famous observatory on Mt. Palomar when I walked into the little restaurant at the foot of this famous mountain one day in 1953. The four stool restaurant, with a few tables, where Adamski worked as a handyman, was crowded when I arrived and he was circulating around serving beer and picking up empty bottles. There was no doubt as to who he was because his fame had spread. To the dozen almost reverently spoken queries, "Are you Adamski?" he modestly nodded his head. Small questions about the flying saucer photos for sale from convenient racks led to more questions and before long the good "professor" had taken a position in the middle of the room and was off and running. In his slightly broken English he told how he was the son of poor, Polish immigrants with hardly any formal education. To look at the man and to listen to his story you had an immediate urge to believe him. Maybe it was his appearance. He was dressed in well worn, but neat, overalls. He had slightly graying hair and the most honest pair of eyes I've ever seen. Or maybe it was the way he told his story. He spoke softly and naively, almost pathetically, giving the impression that "most people think I'm crazy, but honestly, I'm really not." Adamski started his story by telling how he had spent many long and cold nights at his telescope "at the request of the government" trying to photograph one of the flying saucers everyone had been talking about. He'd been successful, as the full photograph racks on the wall showed, and he thought the next step would be to actually try to contact a saucer. For some reason, Adamski didn't know exactly why, on November 19th he'd decided to go out into the Mojave Desert. He'd called some friends and told them to meet him there. By noon the next day the party, which consisted of Adamski and six others, had met and were eating lunch near the town of Desert Center on the California-Arizona border. They looked for saucers, but except for an occasional airplane, the cloudless blue sky was empty. They were about ready to give it up as a bad day when another airplane came over. Again they looked up, but this time, in addition to seeing the airplane, they saw a silvery, cigar-shaped "flying saucer." For some reason, again he didn't know why, the group of people moved down the road where Adamski left them and took off into the desert alone. By this time the "space ship" had disappeared and once again Adamski was about to give up. Then, a flash of light caught his eye and a smaller saucer (he later learned it was a "scout ship") came drifting down and landed about a half mile from him. He swung his camera into action and started to take pictures. Unfortunately, the one picture Adamski had to show was so out of focus the scout ship looked like a desert rock. He took a few more pictures, he told his audience, and had stopped to admire the little scout ship when he suddenly noticed a man standing nearby. Now, even those in the crowded restaurant who had been smirking when he started his story had put down their beers and were listening. This is what they had come to hear. You could actually have heard the proverbial pin drop. Adamski told what went through his mind when he first saw the man-- maybe a prospector. But he noticed the man's long, shoulder-length, sandy-colored hair, his dark skin, his Oriental features and his ski- pant type trousers. He was puzzled. Then it came into his mind like a flash, he was looking at a person from some other world! Through mental pictures, sign language, and a few words of English, Adamski found out the man was from Venus, he was friendly, and that they (the Venusians) were worried about radiation from our atomic bombs. They talked. George pointed to his camera but the man from Venus politely refused to be photographed. Adamski pleaded to go into the "ship" to see how it operated but the Venusian refused this, too. They talked some more--of spaceships and of solar systems--before Adamski walked with his new found friend to the saucer and saw the Venusian off into space. At this point Adamski recalled how he had glanced up in the sky to see the air full of military aircraft. Needless to say, the rest of Adamski's party, who had supposedly seen the "contact" from a mile away, were excited. They rushed up to him and it was then that they noticed the footprints. Plainly imprinted in the desert sand were curious markings made by ridges on the soles of the Venusian's shoes. At the urging of the crowd in the restaurant Adamski took an old shoe box out from under the counter. One of his party, that day, had just happened to have some plaster of paris and the shoe box contained plaster casts of shoe prints with strange, hieroglyphic- like symbols on the soles. No one in the restaurant asked how the weight of a mere man could make such sharp imprints in the dry, coarse desert sand. Next he showed the sworn statements of the witnesses and the crowd moved in around him for a better look. As I left he was graciously filling people in on more details and the cash register was merrily ringing up saucer picture sales. I didn't write the trip off as a complete loss, the weather in California was beautiful. Adamski held the UFO spotlight for some time. The Venusians paid him another visit, this time at the restaurant, and he photographed their "ship." This, whether by Venusian fate or design, increased the flow of traffic to the restaurant at the base of Mt. Palomar. It also had its side effects. An astronomer from the observatory that houses the world famous 200- inch telescope on top of Mt. Palomar told me: "I hate to admit it but the number of week end visitors has picked up here. People drive down to hear George and decide that since they're down here they might as well come up and see our establishment." But George Adamski didn't hold the front center of the stage for long. In rapid succession others stepped forward and hesitantly admitted that they too had been contacted. Truman Bethurum, a journeyman mechanic of Redondo Beach, California, was next up. Actually, he admitted, _he_ had been the first earthman to talk to a person from another world. Back on the night of July 26, 1952, four months before Adamski, a group of eight or ten, short, olive-skinned men with black wavy hair, had awakened him while he was asleep in a truck in the desert near Mormon Flats, Nevada. These little men, unlike Adamski's, spoke any language. "You name it," they'd quipped to Bethurum, "we speak it." In a newspaper article that was voted "Best Read of 1953," Bethurum told how the little men he met had been more cooperative and had actually taken him into their saucer, a huge job 300 feet in diameter and 16 feet high. Once inside, Bethurum had met the captain of the "scow"--a true leader of men. Aura Rhanes was her name and she was a Venus de Milo with arms and warm blood. "When she spoke her words rhymed." They chatted and Bethurum learned that he was on the "Admiral's scow" the command ship of Clarion's fleet of saucers. All in all, Bethurum made eleven visits to Aura's scow. Each time they'd sit and talk. Bethurum told her about the earth and she told of the idyllic, Shangri-La type planet of Clarion--a yet undiscovered planet which is always opposite the moon. But before too long, both Truman Bethurum and George Adamski had to move over. Daniel Fry, an engineer, stepped in. At a press conference to kick off the International Saucer Convention in Los Angeles, Fry told how he had not only contacted the spacemen _two_ _years_ _before_ Adamski and Bethurum, he had actually _ridden_ in a flying saucer. It had all started on the night of July 4, 1950, when engineer Fry was temporarily employed at White Sands Proving Ground in New Mexico. It was a hot night, and with nothing else to do, Fry decided to take a walk across the desert. He hadn't traveled far when he saw a bluish light hovering over the mountains which rim this famous proving ground. He paid no attention. He'd heard flying saucer stories before and just plain didn't believe them. But as he watched, the light came closer and closer and closer, until a weird craft came silently to rest on the desert floor not seventy feet away. For seconds, Fry, who had seen missile age developments at White Sands that would have dumfounded most laymen, merely stood and stared. The object, Fry told newsmen, was an "ovate spheroid about thirty feet at the equator." (Fry has a habit of drifting off into the technical). Its outside surface was a highly polished silver with a slight violet iridescent glow. At first Fry wanted to run but his rigid technical training overrode his common, natural urges. He decided to go over to the object and see what made it tick. He circled it several times and nothing broke the desert silence. Then he touched it. "Better not touch that hull, pal, it's hot," boomed a voice in a Hollywoodian tone. Fry recoiled. The voice softened and added, "Take it easy, pal, you're among friends." After politely reading off the spaceman, or whoever he was, for scaring him, pal Fry and the voice settled down for a friendly moonlight chat. Fry learned that the voice was indeed that of a spaceman and they were down to pick up a new supply of air. After about four years of earth air transfusions, according to the spaceman, they would become adapted to our atmosphere, and our gravity, and become "immunized to your bi-otics." The craft, Fry was told, was a "cargo carrier," unmanned and built to zoom down and scoop up earth air. The conversation went on, waxing technical at times, and ended with an invitation to look into the ship. Then the spaceman, possibly carried away by all the interest Fry was showing, offered a ride. Fry accepted and they antidemagnetized off for New York City. Thirty minutes later they were back at White Sands. Over New York City they came down from 35 to 20 miles and Fry could read the marquee of the Fulton Theater. "The Seven Year Itch" was playing. He hadn't told the Air Force about his ride before because he was afraid he'd lose his job. But, at the press conference, he did plug his new book, _The_ _White_ _Sands_ _Incident_. By this time Adamski had already published his book _Flying_ _Saucers_ _Have_ _Landed_ and it looked as if Fry was going to cut him out. But Fry took a lie detector test on a widely viewed West Coast television show and flunked it flat. His stock dropped as fast as it had risen but the decline was somewhat checked when a well known Southern California medium wrote to "her old friend" J. Edgar Hoover about the situation. Hoover, the story goes, shot back an answer--lie detectors are no good. But the damage had been done. The "rigged" lie detector test had unfortunately relegated Daniel Fry, "engineer," "missile expert," "part owner of an engineering plant," and interplanetary hitchhiker to the bush league. With Adamski and Bethurum on the stage and Fry peeking out of the wings all hell broke loose. One could say that everyone tried to get into the act, but I'd rather think that each colony of space people tried to promote their own candidate. In England, one Cedric Allingham met a Martian on the moors. In France, Germany, the United States, Portugal, Brazil, Spain-- everywhere--people "too uneducated to pull a hoax" met green men, dark men, white men, big men with little heads, little men with big heads and men with pointed heads. They wore motorcycle belts, baggy pants, diver suits, and were naked. One lady proudly announced that a Venusian had tried to seduce her and within days another snorted in disgust. A Martian _had_ seduced her. Then Adamski took a hop through outer space and back. Saucers poured forth words of wisdom via radio, light beams and mental telepathy. All of these messages were duly recorded on tape and sales were hot at $4.50 per 10-minute tape. Not to be outdone by any other lousy planet, the Venusians picked up a young man from Los Angeles and actually took him to Venus. Not once, but three times. He packed in audiences by telling how he had been contacted one night and asked by a "strange man" if he would go on an important mission. Afraid, but not one to shirk his patriotic duties, he met the stranger at a prearranged spot and was whisked off to Venus. During a high level conference up there he was given the word: Tell the earthlings to lay off their atomic weapons, or else. They're killing all our doves and we make our flying saucers out of the feathers our live doves shed. The Venusians, this space traveler warned his audiences, were already infiltrating the earth and he intimated that they were ready to move in case we didn't cease atomic testing. His next two trips to Venus were purely social. The highlight of his lecture, when he awes his audience, is when he whips out his proof: (1) a blood smear on a slide--genuine Venusian blood, (2) an affidavit from his landlady stating he wasn't home on three occasions, and (3) a photo of a Venusian walking in Los Angeles' McArthur Park. The mere fact that the Venusian looks like any Joe Doakes walking down the street is a picayunish point. Venusians look just like us. And it hasn't stopped. During the big UFO flap of 1957 a man stumbled onto a landed saucer and chatted awhile with its occupants. A few months later, soon after the atomic powered _U.S.S._ _Nautilus_ made its historic trip under the polar ice cap, this same man snorted in disgust. He packed his suitcase and started on a lecture tour. Months before _he'd_ been there in a flying saucer. Once again people shelled out hard cash to hear his story. Wherever you are, Mr. P. T. Barnum, you are undoubtedly grinning from ear to ear. But there is a sober side to this apparently comical picture. The common undertone to many of these stories "hot from the lips of a spaceman" is Utopia. On these other worlds there is no illness, they've learned how to cure all diseases. There are no wars, they've learned how to live peaceably. There is no poverty, everyone has everything he wants. There is no old age, they've learned the secret of eternal life. Too many times this subtle pitch can be boiled down to, "Step right up folks and put a donation in the pot. I'm just on the verge of learning the spaceman's secrets and with a little money to carry out my work I'll give _you_ the secret." I've seen a man, crippled by arthritis, hobbling out into the desert in hopes that his "friend who talks to the Martians" could get them to cure him on their next trip. I've seen pensioners, who needed every buck they had, shell out money to "help buy radio equipment" to contact some planet to find out how they'd solved their economic problems. I saw a little old lady in a many times mended dress put down a ten dollar bill to help promote a "peace campaign" backed by the Venusians. She'd lost two sons in the war but had four grandsons she wanted to keep alive. A couple died and left $15,000 to a man to build a "longevity machine" so others could live. The Martians had given him the plans. A woman died of thirst and exposure in the Mojave Desert trying to reach the spot where a man told her he was going to "make a contact." Some of it isn't comical. Even though the field is becoming crowded, through thick and thin, Martian and Venusian, the old Maestro, George Adamski, is still head and shoulders above the rest. The hamburger stand is boarded up and he lives in a big ranch house. He vacations in Mexico and has his own clerical staff. His two books _Flying_ _Saucers_ _Have_ _Landed_ and _Inside_ _the_ _Space_ _Ships_ have sold something in the order of 200,000 copies and have been translated into nearly every language except Russian. To date, he's had eleven visits from people from Mars, Venus and Saturn. Evidently Truman Bethurum's Aura Rhanes put out the word about earthmen because two beautiful spacewomen have now entered Adamski's life: an "incredibly lovely" blonde named Kalna, and the equally beautiful Illmuth. Only a few months ago, while on one of his numerous nationwide lecture tours, a saucer unexpectedly picked Adamski up in Kansas City and took him on a galactic cruise before depositing him at Ft. Madison, Iowa, where he had a lecture date. He "wowed" the packed auditorium with his "proof"--an unused Kansas City to Ft. Madison train ticket. Last week, in the Netherlands (Adamski's nationwide tours have expanded to world-wide tours), he repeated his exploits to Queen Juliana. But at Buckingham Palace, Mr. Barnum, all he saw was the changing of the guard. CHAPTER TWENTY Do They or Don't They? During the past four years the most frequent question I've been asked is: "What do you personally think? Do unidentified flying objects exist, or don't they?" I'm positive they don't. I was very skeptical when I finished my tour of active duty with the Air Force and left Project Blue Book in 1953, but now I'm convinced. Since I left the Air Force the Age of the Satellite has arrived and we're in it. Along with this new era came the long range radars, the satellite tracking cameras, and the other instruments that would have picked up any type of "spaceship" coming into our atmosphere. None of this instrumentation has ever given any indication of any type of unknown vehicle entering the earth's atmosphere. I checked this with the Department of Defense and I checked this through friends associated with tracking projects. In both cases the results were completely negative. There's not even a glimmer of hope for the UFO. Then there's Project MOONWATCH, the Optical Satellite Tracking Program for the International Geophysical Year. Dr. J. Allen Hynek, the director of MOONWATCH wrote to me: "I can quite safely say that we have no record of ever having received from our MOONWATCH teams any reports of sightings of unidentified objects which had any characteristics different from those of an orbiting satellite, a slow meteor, or of a suspected plane mistaken for a satellite." Dr. Hynek should know. He has investigated and analyzed more UFO reports than any other scientist in the world. And the third convincing point is that twelve years have passed since the first UFO report was made and still there is not one shred of material evidence of anything unknown and no photos of anything other than meaningless blobs of light. The next question that always arises is: "But people are seeing something. Experienced observers, like pilots, scientists and radar operators have reported UFO's." To be very frank, we heard the words "experienced observer" so many times these words soon began to make us ill. Everyone, except housewives with myopia, were experienced observers. Pilots, "scientists" (a term used equally as loosely), engineers, radar operators, everyone who reported a UFO was some kind of an "experienced observer." This man had taught aircraft recognition during World War II. He was an experienced observer. That man spent four years in the Air Force. He was an experienced observer. We soon learned that everyone is an experienced observer as long as what he sees is familiar to him. As soon as he sees something unfamiliar it's a UFO. Pilots probably come as close to falling into this category as anyone since they do spend a lot of time looking around the sky. But even those who can rattle off the names and locations of stars, planets and constellations don't know about a few relatively rare astronomical phenomena. The bolide, or super meteor, is a good example. Few pilots have ever, or will ever, see a deluxe model bolide but when they do they'll never forget it. It's like someone shooting a flare in front of your face. There are a number of reports of bolides in the Blue Book files and each pilot who made each report called each bolide a UFO. The descriptions are almost identical to the classic descriptions of bolides found in astronomy books. While on the subject of meteors, if most people realized that meteors can have a flat trajectory, they can go from horizon to horizon, they can travel in "formation" (groups), and they can be seen in daylight (as "large silver discs"), the work of UFO investigators would be lighter. Enough of meteors and back to our experienced observers. The example of pilots and bolides holds true in many, many other cases. Take high flying jets for example. To a person in an area where there isn't much high altitude air traffic, a thin, blood red streak in the sky at sunset, or shortly after, is a UFO. To anyone in an area where there are a lot of high flying jets even our myopic housewife, it's just another vapor trail. They're as common as the sunset. When the flashing red strobe lights, now used on practically all aircraft, were still in the experimental stage back in 1951 they gave us fits. Every time an airplane with one of these flashing lights made a flight people within miles, including other pilots, called in UFO reports. Now these strobe lights are common and no one even bothers to look up. The same held true, and still does, for the odd array of lights used on tanker planes during aerial refueling operations. Some phenomena are so rare and so little is known about them that they are always UFO's. The most common is the disc following the airplane. I've never heard an explanation for this phenomenon but it exists and I've seen it on three occasions. Maybe a dense blob of air tears off the airplane, floats along behind, and reflects the sunlight. Whatever it is, it gives the illusion of a saucer "chasing" an airplane. Sometimes it's steady and sometimes it darts back and forth. It only stays in view a few seconds and when it disappears it fades and looks for all the world as if it's suddenly streaking away into the distance. Birds, bees, bugs, airplanes, planets, stars, balloons, and a host of other common everyday objects become UFO's the instant they are viewed under other than normal situations. Then there is radar. This poor inanimate piece of electronic equipment has taken a beating when UFO proof is being offered. "Radar is not subject to the frailties of the human mind," is the outcry of every saucer fan, "and radar has seen UFO's." Radar is no better than the radar observer and the radar observer has a mind. And where there's a mind there is the same old trouble. If the presentation on the radarscope doesn't look like it has looked for years a UFO is being tracked. Radar is temperamental. The scope presentation of each radar has certain peculiarities and an operator gets used to seeing these. Occasionally, and for some unknown reason, these peculiarities suddenly change. For months a temperature inversion may cause 50 or 75 targets to appear on the radarscope. The operator has learned to recognize them and knows that they are caused by weather. They are not UFO's. But overnight something changes and now this same temperature inversion causes only one or two targets. The operator isn't used to seeing this and the targets are now UFO's. Many times we'd stumble across the fact that after the first report of a UFO being tracked on radar the same identical type of target would be tracked again, many times. But by this time the operator would have learned that they were caused by weather and it wouldn't be reported to us. It is interesting to note that, to my knowledge, there has never been a radar sighting classed as "unknown" when radarscope photos were taken. The reason is simple. The radar operator can take ample time to re-examine what he had to interpret in seconds during the actual sighting. Also, more experienced radar operators have a chance to examine the scope presentation. Mixed in with the fact that there are few really qualified observers on this earth is the power of suggestion. About the time someone yells "UFO!" and points, all powers of reasoning come to a screeching halt. We saw this happen day after day. Few people I ever talked to, once they had decided they were looking at a UFO, stopped to calmly say to themselves, "Now couldn't this be a balloon, star, planet, or something else explainable?" In one instance I traveled halfway across the United States to investigate a report made by a high ranking man in the State Department. An experienced observer. It was evening by the time I got to talk to him and after he'd excitedly told me all the pertinent facts, how this bright fight had "jumped across the sky," he said, "Want to see it? It's still there but it's not jumping now." We went outside and there was Jupiter. Then, there was the UFO over Dayton, Ohio, in the summer of 1952. I first heard about it at home. It was about six in the evening when the phone rang and it was one of the tower operators at Patterson Field. The tower operators at Lockbourne AFB in Columbus, Ohio, 60 miles east of Dayton, had spotted "three fiery spheres flying in a V- formation" over their base. Two F-84's had been scrambled to intercept and they were in the air right now. So far, the tower operator told me, the intercept had been unsuccessful because the objects were traveling "two to three thousand miles an hour" and were too high for the old F-84's. He was monitoring the two jets' radio conversation and he put his telephone near the speaker. I heard: "At 28,000 and still above us." "High speed." "Headed toward Wright-Patterson." "Low on fuel, going home." I made it to my car in record time and took off toward Wright- Patterson, about twelve miles from where I was living. It was still light, although the sun was low, and as I drove I kept looking toward the east. Nothing. I reached the gate, showed my pass to the guard, and had just written the whole thing off as another UFO report when I saw them. They convinced me. Off to the east of the airbase were three objects that can best be described as three half-sized suns. By the time I arrived at base operations there were three or four dozen people on the ramp, all looking up. The standard comment was: "Look at them go." About this time a C-54 transport taxied up and stopped. It was the "Kittyhawk Flight" from Washington and I knew several people who got off. One passenger, an officer from ATIC, ran up to me and handed me a roll of film. "Here's some pictures of them," he said breathlessly. "I never thought I'd see one." The next passengers I recognized were two other officers, Ph.D. psychologists from the Aero Medical Laboratory. I knew them because they had visited Blue Book many times collecting data for a paper they were writing on UFO's. The title of the paper was to be: _The_ _Psychological_ _Aspects_ _of_ _UFO_ _Sightings_. Almost climbing over each other in their effort to tell their story they told me how they had watched the UFO's from the C-54. Both had seen them "dogfighting" between themselves. "How fast were they going?" I asked. "Like hell," was their only answer but the way they said it and the looks on their faces emphasized their statement. The crowd on the ramp had increased by now and some of the newcomers had binoculars. The men with the binoculars were the focal point of several individual groups as they watched and gave blow-by-blow accounts. Some of the crowd were talking about jet fighters and it suddenly dawned on me that just across the parking lot was the operations office of the local ADC jet outfit, the 97th Fighter Interceptor Squadron. I ran over to interceptor operations and went in. I knew the duty officer because several times before the 97th people had chased balloons over Dayton. When I told him about the UFO's all I received was a rather uninterested stare. When I said they were over the base he did me the courtesy of going out to look. He came running back in and hit the scramble button. Three minutes later two F-86's were headed UFOward. They soon disappeared but their vapor trails kept the tense crowd informed of their progress. And believe me there was tension. As the vapor trails spiraled up, first as two distinct plumes, and later only one--as they blended at altitude--more than one pilot standing on the ramp expressed his thankfulness for his unenviable position--on the ground watching. The vapor trails thinned out and disappeared right under the three UFO's and it was obvious that the two jets had closed in. Here were three that didn't escape. That night the 97th Fighter Interceptor Squadron added three more balloons to their record. The F-86's had been able to climb higher than the F-84's. The next morning photos confirmed the balloons. They had been tethered together and carried an instrument package. I had been fooled. Two Ph.D psychologists who had studied UFO's had been fooled. A C-54 load of "experienced observers" (many pilots) had been fooled. The tower operators had been fooled and so had a hundred others. This was an interesting sighting and we used to discuss it a lot. All of the observers later agreed that what made them so excited was the tower operator's announcement: "F-84's from Lockbourne are chasing three high speed objects." This set the stage and from then on no one even considered the fact that if the objects had been traveling 2000 or 3000 miles an hour they would have been long gone in the fifteen minutes we watched them. Secondly, I found out that the C-54, a slow airplane, had actually overtaken and passed the balloons between Columbus and Dayton but none of the passengers I talked to had stopped to think of this. And I'm positive that in our minds the balloons, which were about 40 feet in diameter and at 40,000 feet, looked a lot larger than they actually were. I know the power of suggestion plays an important role in UFO sightings. Once you're convinced you're looking at a UFO you can see a lot of things. But then there's the "unknowns." Any good saucer fan--wild eyed or sober--will magnanimously concede that a certain percentage of the UFO sightings are the misidentification of known objects. They drag out the "unknowns" as the "proof." Technically speaking, an "unknown" report is one that has been made by a reliable observer (not necessarily experienced). The report has been exhaustively investigated and analyzed and there is no logical explanation. To this, the Air Force says: "The Air Force emphasizes the belief that if more immediate detailed objective observational data could have been obtained on the 'unknowns' these too could have been satisfactorily explained." I think the Case of the Lubbock Lights is an excellent example of this. It is probably one of the most thoroughly investigated reports in the UFO files and it contained the most precise observational data we ever received. Scientists from far and near tried to solve it. It remained an "unknown." The men who made the original sightings stuck by the case and furnished the "more detailed objective observational data" the Air Force speaks of. The mysterious fights appeared again and instead of looking for something high in the air they looked for something low and found the solution. The world famous Lubbock Lights were night flying moths reflecting the bluish-green light of a nearby row of mercury vapor street lights. I will go a step further than the Air Force, however, and quote from a letter from ex-Lieutenant Andy Flues, once an investigator for Project Blue Book. Flues' statement sums up my beliefs and, I'm quite sure, the beliefs of everyone who has ever worked on Projects Sign, Grudge or Blue Book. Flues wrote: "Even taking into consideration the highly qualified backgrounds of some of the people who made sightings, there was not one single case which, upon the closest analysis, could not be logically explained in terms of some common object or phenomenon." The only reason there are any "unknowns" in the UFO files is that an effort is made to be scientific in making evaluations. And being scientific doesn't allow for any educated assuming of missing data or the passing of judgment on the character of the observer. However, this is closely akin to being forced to follow the Marquis of Queensbury rules in a fight with a hood. The investigation of any UFO sighting is an inexact science at the very best. Any UFO investigator, after a few months of being steeped in UFO lore and allowed a few scientific rabbit punches, can make the best of the "unknowns" look like a piece of well-holed Swiss cheese. But regardless of what I say, or what the Air Force says, or what anyone says, we are stuck with flying saucers. And as long as people report unidentified objects in the air, it's the Air Force's responsibility to explain them. Project Blue Book will live on. No responsible scientist will argue with the fact that other solar systems may be inhabited and that some day we may meet those people. But it hasn't happened yet and until that day comes we're stuck with our Space Age Myth--the UFO. 
38187	----	Note: Project Gutenberg also has an HTML version of this file which includes the original illustrations. See 38187-h.htm or 38187-h.zip: (http://www.gutenberg.org/files/38187/38187-h/38187-h.htm) or (http://www.gutenberg.org/files/38187/38187-h.zip) +-----------------------------------------------------------------+ | TRANSCRIBER'S NOTES | | | | Transcription used for this e-text: | | Italic text in the original work is transcribed between | | underscores, as in _text_; | | Bold face text in the original work is transcribed between | | equal signs, as in =text=; | | Bold face underlined text in the original work is transcribed | | between tildes, as in ~text~; | | Super- and subscripts in the original work are transcribed as | | ^{text} and _{text}, respectively; | | Greek characters have been transcribed as [alpha], [beta], | | etc.; | | The oe-ligature in Phoenix has been transcribed as oe. | | | | Some in-line multi-line formulas have been transcribed as | | single-line formulas, where necessary with brackets added. | | | | Some table headings have been replaced by legends [A], [B], etc;| | these are listed directly above the relevant tables. | | | | More extensive Transcriber's Notes may be found at the end of | | this text. | +-----------------------------------------------------------------+ AVIATION ENGINES Design--Construction--Operation and Repair by FIRST LIEUT. VICTOR W. PAGÉ, A. S. S. C., U. S. R. * * * * * ~JUST PUBLISHED~ =AVIATION ENGINES. Their Design, Construction, Operation and Repair.= By Lieut. VICTOR W. PAGÉ, Aviation Section, S.C.U.S.R. A practical work containing valuable instructions for aviation students, mechanicians, squadron engineering officers and all interested in the construction and upkeep of airplane power plants. 576 octavo pages. 250 illustrations. Price $3.00. =AVIATION CHART, or the Location of Airplane Power Plant Troubles Made Easy.= By Lieut. VICTOR W. PAGÉ, A.S., S.C.U.S.R. A large chart outlining all parts of a typical airplane power plant, showing the points where trouble is apt to occur and suggesting remedies for the common defects. Intended especially for aviators and aviation mechanics on school and field duty. Price 50 cents. =GLOSSARY OF AVIATION TERMS.= Compiled by Lieuts. VICTOR W. PAGÉ, A.S., S.C.U.S.R. and PAUL MONTARIOL of the French Flying Corps on duty at Signal Corps Aviation School, Mineola, L. I. A complete glossary of practically all terms used in aviation, having lists in both French and English, with equivalents in either language. A very valuable book for all who are about to leave for duty overseas. Price, cloth, $1.00. =THE NORMAN W. HENLEY PUBLISHING COMPANY= 2 WEST 45TH ST., NEW YORK * * * * * [Illustration: Part Sectional View of Hall-Scott Airplane Motor, Showing Principal Parts.] * * * * * CENSORED This Book Entitled AVIATION ENGINES By LIEUT. VICTOR W. PAGÉ has been censored by the United States Government, and pages and parts of pages have been omitted by special instructions from Washington. The book has been passed by THE COMMITTEE ON PUBLIC INFORMATION and is as complete as we can furnish it, and we so advise the purchaser of it. THE NORMAN W. HENLEY PUBLISHING COMPANY * * * * * AVIATION ENGINES Design--Construction--Operation and Repair A Complete, Practical Treatise Outlining Clearly the Elements of Internal Combustion Engineering with Special Reference to the Design, Construction, Operation and Repair of Airplane Power Plants; Also the Auxiliary Engine Systems, Such as Lubrication, Carburetion, Ignition and Cooling. It Includes Complete Instructions for Engine Repairing and Systematic Location of Troubles, Tool Equipment and Use of Tools, Also Outlines the Latest Mechanical Processes. by FIRST LIEUT. VICTOR W. PAGÉ, A. S. S. C., U. S. R. Assistant Engineering Officer, Signal Corps Aviation School, Mineola, L. I. Author of "The Modern Gasoline Automobile," Etc. [Illustration] Contains Valuable Instructions for All Aviation Students, Mechanicians, Squadron Engineering Officers and All Interested in the Construction and Upkeep of Airplane Power Plants. New York The Norman W. Henley Publishing Company 2 West 45th Street 1917 Copyrighted, 1917 By The Norman W. Henley Publishing Co. Printed in U. S. A. All Illustrations in This Book Have Been Specially Made by the Publishers, and Their Use, Without Permission, Is Strictly Prohibited Composition, Electrotyping and Presswork by the Publishers Printing Co., New York PREFACE In presenting this treatise on "Aviation Engines," the writer realizes that the rapidly developing art makes it difficult to outline all latest forms or describe all current engineering practice. This exposition has been prepared primarily for instruction purposes and is adapted for men in the Aviation Section, Signal Corps, and students who wish to become aviators or aviation mechanicians. Every effort has been made to have the engineering information accurate, but owing to the diversity of authorities consulted and use of data translated from foreign language periodicals, it is expected that some slight errors will be present. The writer wishes to acknowledge his indebtedness to such firms as the Curtiss Aeroplane and Motor Co., Hall-Scott Company, Thomas-Morse Aircraft Corporation and General Vehicle Company for photographs and helpful descriptive matter. Special attention has been paid to instructions on tool equipment, use of tools, trouble "shooting" and engine repairs, as it is on these points that the average aviation student is weakest. Only such theoretical consideration of thermo-dynamics as was deemed absolutely necessary to secure a proper understanding of engine action after consulting several instructors is included, the writer's efforts having been confined to the preparation of a practical series of instructions that would be of the greatest value to those who need a diversified knowledge of internal-combustion engine operation and repair, and who must acquire it quickly. The engines described and illustrated are all practical forms that have been fitted to airplanes capable of making flights and may be considered fairly representative of the present state of the art. VICTOR W. PAGÉ, _1st Lieut. A. S. S. C., U. S. R_. MINEOLA, L. I., October, 1917. CONTENTS PAGES CHAPTER I Brief Consideration of Aircraft Types--Essential Requirements of Aerial Motors--Aviation Engines Must Be Light--Factors Influencing Power Needed--Why Explosive Motors Are Best--Historical--Main Types of Internal Combustion Engines 17-36 CHAPTER II Operating Principles of Two- and Four-Stroke Engines--Four-cycle Action--Two-cycle Action--Comparing Two- and Four-cycle Types-- Theory of Gas and Gasoline Engine--Early Gas-Engine Forms-- Isothermal Law--Adiabatic Law--Temperature Computations--Heat and Its Work--Conversion of Heat to Power--Requisites for Best Power Effect 37-59 CHAPTER III Efficiency of Internal Combustion Engines--Various Measures of Efficiency--Temperatures and Pressures--Factors Governing Economy --Losses in Wall Cooling--Value of Indicator Cards--Compression in Explosive Motors--Factors Limiting Compression--Causes of Heat Losses and Inefficiency--Heat Losses to Cooling Water 60-79 CHAPTER IV Engine Parts and Functions--Why Multiple Cylinder Engines Are Best --Describing Sequence of Operations--Simple Engines--Four and Six Cylinder Vertical Tandem Engines--Eight and Twelve Cylinder V Engines--Radial Cylinder Arrangement--Rotary Cylinder Forms 80-109 CHAPTER V Properties of Liquid Fuels--Distillates of Crude Petroleum-- Principles of Carburetion Outlined--Air Needed to Burn Gasoline-- What a Carburetor Should Do--Liquid Fuel Storage and Supply-- Vacuum Fuel Feed--Early Vaporizer Forms--Development of Float Feed Carburetor--Maybach's Early Design--Concentric Float and Jet Type --Schebler Carburetor--Claudel Carburetor--Stewart Metering Pin Type--Multiple Nozzle Vaporizers--Two-Stage Carburetor--Master Multiple Jet Type--Compound Nozzle Zenith Carburetor--Utility of Gasoline Strainers--Intake Manifold Design and Construction-- Compensating for Various Atmospheric Conditions--How High Altitude Affects Power--The Diesel System--Notes on Carburetor Installation--Notes on Carburetor Adjustment 110-154 CHAPTER VI Early Ignition Systems--Electrical Ignition Best--Fundamentals of Magnetism Outlined--Forms of Magneto--Zones of Magnetic Influence --How Magnets are Made--Electricity and Magnetism Related--Basic Principles of Magneto Action--Essential Parts of Magneto and Functions--Transformer Coil Systems--True High Tension Type--The Berling Magneto--Timing and Care--The Dixie Magneto--Spark-Plug Design and Application--Two-Spark Ignition--Special Airplane Plug 155-200 CHAPTER VII Why Lubrication Is Necessary--Friction Defined--Theory of Lubrication--Derivation of Lubricants--Properties of Cylinder Oils --Factors Influencing Lubrication System Selection--Gnome Type Engines Use Castor Oil--Hall-Scott Lubrication System--Oil Supply by Constant Level Splash System--Dry Crank-Case System Best for Airplane Engines--Why Cooling Systems Are Necessary--Cooling Systems Generally Applied--Cooling by Positive Pump Circulation-- Thermo-Syphon System--Direct Air-Cooling Methods--Air-Cooled Engine Design Considerations 201-232 CHAPTER VIII Methods of Cylinder Construction--Block Castings--Influence on Crank-Shaft Design--Combustion Chamber Design--Bore and Stroke Ratio--Meaning of Piston Speed--Advantage of Off-Set Cylinders-- Valve Location of Vital Import--Valve Installation Practice--Valve Design and Construction--Valve Operation--Methods of Driving Cam-Shaft--Valve Springs--Valve Timing--Blowing Back--Lead Given Exhaust Valve--Exhaust Closing, Inlet Opening--Closing the Inlet Valve--Time of Ignition--How an Engine is Timed--Gnome "Monosoupape" Valve Timing--Springless Valves--Four Valves per Cylinder 233-286 CHAPTER IX Constructional Details of Pistons--Aluminum Cylinders and Pistons --Piston Ring Construction--Leak Proof Piston Rings--Keeping Oil Out of Combustion Chamber--Connecting Rod Forms--Connecting Rods for Vee Engines--Cam-Shaft and Crank-Shaft Designs--Ball Bearing Crank-Shafts--Engine Base Construction 287-323 CHAPTER X Power Plant Installation--Curtiss OX-2 Engine Mounting and Operating Rules--Standard S. A. E. Engine Bed Dimensions-- Hall-Scott Engine Installation and Operation--Fuel System Rules --Ignition System--Water System--Preparations to Start Engine-- Mounting Radial and Rotary Engines--Practical Hints to Locate Engine Troubles--All Engine Troubles Summarized--Location of Engine Troubles Made Easy 324-375 CHAPTER XI Tools for Adjusting and Erecting--Forms of Wrenches--Use and Care of Files--Split Pin Removal and Installation--Complete Chisel Set --Drilling Machines--Drills, Reamers, Taps and Dies--Measuring Tools--Micrometer Calipers and Their Use--Typical Tool Outfits --Special Hall-Scott Tools--Overhauling Airplane Engines--Taking Engine Down--Defects in Cylinders--Carbon Deposits, Cause and Prevention--Use of Carbon Scrapers--Burning Out Carbon with Oxygen --Repairing Scored Cylinders--Valve Removal and Inspection --Reseating and Truing Valves--Valve Grinding Processes-- Depreciation in Valve Operating System--Piston Troubles--Piston Ring Manipulation--Fitting Piston Rings--Wrist-Pin Wear-- Inspection and Refitting of Engine Bearings--Scraping Brasses to Fit--Fitting Connecting Rods--Testing for Bearing Parallelism-- Cam-Shafts and Timing Gears--Precautions in Reassembling Parts 376-456 CHAPTER XII Aviation Engine Types--Division in Classes--Anzani Engines--Canton and Unné Engine--Construction of Gnome Engines--"Monosoupape" Gnome--German "Gnome" Type--Le Rhone Engine--Renault Air-Cooled Engine--Simplex Model "A" Hispano-Suiza--Curtiss Aviation Motors-- Thomas-Morse Model 88 Engine--Duesenberg Engine--Aeromarine Six-Cylinder--Wisconsin Aviation Engines--Hall-Scott Engines-- Mercedes Motor--Benz Motor--Austro-Daimler Engine--Sunbeam-Coatalen --Indicating and Measuring Instruments--Air Starting Systems-- Electric Starting--Battery Ignition 457-571 INDEX 573 LIST OF ILLUSTRATIONS AVIATION ENGINES DESIGN--CONSTRUCTION--REPAIR CHAPTER I Brief Consideration of Aircraft Types--Essential Requirements of Aerial Motors--Aviation Engines Must Be Light--Factors Influencing Power Needed--Why Explosive Motors Are Best-- Historical--Main Types of Internal Combustion Engines. BRIEF CONSIDERATION OF AIRCRAFT TYPES The conquest of the air is one of the most stupendous achievements of the ages. Human flight opens the sky to man as a new road, and because it is a road free of all obstructions and leads everywhere, affording the shortest distance to any place, it offers to man the prospect of unlimited freedom. The aircraft promises to span continents like railroads, to bridge seas like ships, to go over mountains and forests like birds, and to quicken and simplify the problems of transportation. While the actual conquest of the air is an accomplishment just being realized in our days, the idea and yearning to conquer the air are old, possibly as old as intellect itself. The myths of different races tell of winged gods and flying men, and show that for ages to fly was the highest conception of the sublime. No other agent is more responsible for sustained flight than the internal combustion motor, and it was only when this form of prime mover had been fully developed that it was possible for man to leave the ground and alight at will, not depending upon the caprices of the winds or lifting power of gases as with the balloon. It is safe to say that the solution of the problem of flight would have been attained many years ago if the proper source of power had been available as all the essential elements of the modern aeroplane and dirigible balloon, other than the power plant, were known to early philosophers and scientists. Aeronautics is divided into two fundamentally different branches--aviatics and aerostatics. The first comprises all types of aeroplanes and heavier than air flying machines such as the helicopters, kites, etc.; the second includes dirigible balloons, passive balloons and all craft which rise in the air by utilizing the lifting force of gases. Aeroplanes are the only practical form of heavier-than-air machines, as the helicopters (machines intended to be lifted directly into the air by propellers, without the sustaining effect of planes), and ornithopters, or flapping wing types, have not been thoroughly developed, and in fact, there are so many serious mechanical problems to be solved before either of these types of air craft will function properly that experts express grave doubts regarding the practicability of either. Aeroplanes are divided into two main types--monoplanes or single surface forms, and bi-planes or machines having two sets of lifting surfaces, one suspended over the other. A third type, the triplane, is not very widely used. Dirigible balloons are divided into three classes: the rigid, the semi-rigid, and the non-rigid. The rigid has a frame or skeleton of either wood or metal inside of the bag, to stiffen it; the semi-rigid is reinforced by a wire net and metal attachments; while the non-rigid is just a bag filled with gas. The aeroplane, more than the dirigible and balloon, stands as the emblem of the conquest of the air. Two reasons for this are that power flight is a real conquest of the air, a real victory over the battling elements; secondly, because the aeroplane, or any flying machine that may follow, brings air travel within the reach of everybody. In practical development, the dirigible may be the steamship of the air, which will render invaluable services of a certain kind, and the aeroplane will be the automobile of the air, to be used by the multitude, perhaps for as many purposes as the automobile is now being used. ESSENTIAL REQUIREMENTS OF AERIAL MOTORS One of the marked features of aircraft development has been the effect it has had upon the refinement and perfection of the internal combustion motor. Without question gasoline-motors intended for aircraft are the nearest to perfection of any other type yet evolved. Because of the peculiar demands imposed upon the aeronautical motor it must possess all the features of reliability, economy and efficiency now present with automobile or marine engines and then must have distinctive points of its own. Owing to the unstable nature of the medium through which it is operated and the fact that heavier-than-air machines can maintain flight only as long as the power plant is functioning properly, an airship motor must be more reliable than any used on either land or water. While a few pounds of metal more or less makes practically no difference in a marine motor and has very little effect upon the speed or hill-climbing ability of an automobile, an airship motor must be as light as it is possible to make it because every pound counts, whether the motor is to be fitted into an aeroplane or in a dirigible balloon. Airship motors, as a rule, must operate constantly at high speeds in order to obtain a maximum power delivery with a minimum piston displacement. In automobiles, or motor boats, motors are not required to run constantly at their maximum speed. Most aircraft motors must function for extended periods at speed as nearly the maximum as possible. Another thing that militates against the aircraft motor is the more or less unsteady foundation to which it is attached. The necessarily light framework of the aeroplane makes it hard for a motor to perform at maximum efficiency on account of the vibration of its foundation while the craft is in flight. Marine and motor car engines, while not placed on foundations as firm as those provided for stationary power plants, are installed on bases of much more stability than the light structure of an aeroplane. The aircraft motor, therefore, must be balanced to a nicety and must run steadily under the most unfavorable conditions. AERIAL MOTORS MUST BE LIGHT The capacity of light motors designed for aerial work per unit of mass is surprising to those not fully conversant with the possibilities that a thorough knowledge of proportions of parts and the use of special metals developed by the automobile industry make possible. Activity in the development of light motors has been more pronounced in France than in any other country. Some of these motors have been complicated types made light by the skillful proportioning of parts, others are of the refined simpler form modified from current automobile practice. There is a tendency to depart from the freakish or unconventional construction and to adhere more closely to standard forms because it is necessary to have the parts of such size that every quality making for reliability, efficiency and endurance are incorporated in the design. Aeroplane motors range from two cylinders to forms having fourteen and sixteen cylinders and the arrangement of these members varies from the conventional vertical tandem and opposed placing to the V form or the more unusual radial motors having either fixed or rotary cylinders. The weight has been reduced so it is possible to obtain a complete power plant of the revolving cylinder air-cooled type that will not weigh more than three pounds per actual horse-power and in some cases less than this. If we give brief consideration to the requirements of the aviator it will be evident that one of the most important is securing maximum power with minimum mass, and it is desirable to conserve all of the good qualities existing in standard automobile motors. These are certainty of operation, good mechanical balance and uniform delivery of power--fundamental conditions which must be attained before a power plant can be considered practical. There are in addition, secondary considerations, none the less desirable, if not absolutely essential. These are minimum consumption of fuel and lubricating oil, which is really a factor of import, for upon the economy depends the capacity and flying radius. As the amount of liquid fuel must be limited the most suitable motor will be that which is powerful and at the same time economical. Another important feature is to secure accessibility of components in order to make easy repair or adjustment of parts possible. It is possible to obtain sufficiently light-weight motors without radical departure from established practice. Water-cooled power plants have been designed that will weigh but four or five pounds per horse-power and in these forms we have a practical power plant capable of extended operation. FACTORS INFLUENCING POWER NEEDED Work is performed whenever an object is moved against a resistance, and the amount of work performed depends not only on the amount of resistance overcome but also upon the amount of time utilized in accomplishing a given task. Work is measured in horse-power for convenience. It will take one horse-power to move 33,000 pounds one foot in one minute or 550 pounds one foot in one second. The same work would be done if 330 pounds were moved 100 feet in one minute. It requires a definite amount of power to move a vehicle over the ground at a certain speed, so it must take power to overcome resistance of an airplane in the air. Disregarding the factor of air density, it will take more power as the speed increases if the weight or resistance remains constant, or more power if the speed remains constant and the resistance increases. The airplane is supported by air reaction under the planes or lifting surfaces and the value of this reaction depends upon the shape of the aerofoil, the amount it is tilted and the speed at which it is drawn through the air. The angle of incidence or degree of wing tilt regulates the power required to a certain degree as this affects the speed of horizontal flight as well as the resistance. Resistance may be of two kinds, one that is necessary and the other that it is desirable to reduce to the lowest point possible. There is the wing resistance and the sum of the resistances of the rest of the machine such as fuselage, struts, wires, landing gear, etc. If we assume that a certain airplane offered a total resistance of 300 pounds and we wished to drive it through the air at a speed of sixty miles per hour, we can find the horse-power needed by a very simple computation as follows: The product of 300 pounds resistance times speed of 88 feet per second times 60 seconds in a minute ----------------------------------------------------- = H.P. needed. divided by 33,000 foot pounds per minute in one horse-power The result is the horse-power needed, or 300 × 88 × 60 --------------- = 48 H.P. 33,000 Just as it takes more power to climb a hill than it does to run a car on the level, it takes more power to climb in the air with an airplane than it does to fly on the level. The more rapid the climb, the more power it will take. If the resistance remains 300 pounds and it is necessary to drive the plane at 90 miles per hour, we merely substitute proper values in the above formula and we have 300 pounds times 132 feet per second times 60 seconds in a minute ----------------------------------------------- = 72 H.P. 33,000 foot pounds per minute in one horse-power The same results can be obtained by dividing the product of the resistance in pounds times speed in feet per second by 550, which is the foot-pounds of work done in one second to equal one horse-power. Naturally, the amount of propeller thrust measured in pounds necessary to drive an airplane must be greater than the resistance by a substantial margin if the plane is to fly and climb as well. The following formulæ were given in "The Aeroplane" of London and can be used to advantage by those desiring to make computations to ascertain power requirements: [Illustration: Fig. 1.--Diagrams Illustrating Computations for Horse-Power Required for Airplane Flight.] The thrust of the propeller depends on the power of the motor, and on the diameter and pitch of the propeller. If the required thrust to a certain machine is known, the calculation for the horse-power of the motor should be an easy matter. The required thrust is the sum of three different "resistances." The first is the "drift" (dynamical head resistance of the aerofoils), i.e., tan [alpha] × lift (_L_), lift being equal to the total weight of machine (_W_) for horizontal flight and [alpha] equal to the angle of incidence. Certainly we must take the tan [alpha] at the maximum _K_{y}_ value for minimum speed, as then the drift is the greatest (Fig. 1, A). Another method for finding the drift is _D_ = _K_ × _AV_^{2}, when we take the drift again so as to be greatest. The second "resistance" is the total head resistance of the machine, at its maximum velocity. And the third is the thrust for climbing. The horse-power for climbing can be found out in two different ways. I first propose to deal with the method, where we find out the actual horse-power wanted for a certain climbing speed to our machine, where climbing speed/sec. × _W_ H.P. = --------------------------- 550 In this case we know already the horse-power for climbing, and we can proceed with our calculation. With the other method we shall find out the "thrust" in pounds or kilograms wanted for climbing and add it to drift and total head resistance, and we shall have the total "thrust" of our machine and we shall denote it with _T_, while thrust for climbing shall be _T_{c}_. The following calculation is at our service to find out _V_{c}_ × _W_ this thrust for climbing --------------- = H.P., 550 H.P. × 550 thence _V_{c}_ = ------------ (1) _W_ _T_{c}_ × _V_ H.P. = --------------, then from 550 _T_{c}_ × _V_ --------------- × 550 550 _T_{c}_ × _V_ (1) _V_{c}_ = ----------------------- = ---------------, thence, _W_ _W_ _V_{c}_ × _W_ T_{c} = ---------------. _V_ Whether _T_ means drifts, head resistance and thrust for climbing, or drift and head resistance only, the following calculation is the same, only in the latter case, of course, we must add the horse-power required for climbing to the result to obtain the total horse-power. Now, when we know the total thrust, we shall find the horse-power in the following manner: _Pr_2[pi]_R_ We know that the H.P. = -------------- in kilograms, or in 75 × 60 _Pr_2[pi]_R_ English measure, H.P. = -------------- (Fig. 1, B) 33,000 where _P_ = pressure in klgs. or lbs. _r_ = radius on which _P_ is acting. _R_ = Revolution/min. _M.R._2[pi] When _P_ × _r_ = _M_, then H.P. = -------------, thence, 4,500 H.P. × 4,500 716.2 H.P. _M_ = -------------- = ------------ in meter kilograms, _R_2[pi] _R_ H.P. 33,000 5253.1 H.P. or in English system _M_ = ------------- = ------------- in _R_2[pi] _R_ foot pounds. Now the power on the circumference of the propeller will be reduced by its radius, so it will be _M_/_r_ = _p_. A part of _p_ will be used for counteracting the air and bearing friction, so that the total power on the circumference of the propeller will be (_M_/_r_) × [eta] = _p_ where [eta] is the mechanical efficiency of the propeller. Now [eta] --------------- = _T_, where [alpha] is taken on the tip of the _tan_ [alpha] propeller. I take [alpha] at the tip, but it can be taken, of course, at any point, but then in equation _p_ = _M_/_r_, _r_ must be taken only up to this point, and not the whole radius; but it is more comfortable to take it at the tip, as Pitch _tan_ [alpha] = ---------- (Fig. 1, C). _r_2[pi] Now we can write up the equation of the thrust: 716.2 H.P. [eta] 5253.1 H.P. [eta] -------------------, or in English measure ------------------- _R r tan [alpha]_ _R r tan [alpha]_ _T_ × _R_ × _r tan_ [alpha] thence H.P. = -----------------------------, or in English measure 716.2[eta] _T_ × _R_ × _r tan_ [alpha] -----------------------------. 5253.1[eta] The computations and formulæ given are of most value to the student engineer rather than matters of general interest, but are given so that a general idea may be secured of how airplane design influences power needed to secure sustained flight. It will be apparent that the resistance of an airplane depends upon numerous considerations of design which require considerable research in aerodynamics to determine accurately. It is obvious that the more resistance there is, the more power needed to fly at a given speed. Light monoplanes have been flown with as little as 15 horse-power for short distances, but most planes now built use engines of 100 horse-power or more. Giant airplanes have been constructed having 2,000 horse-power distributed in four power units. The amount of power provided for an airplane of given design varies widely as many conditions govern this, but it will range from approximately one horse-power to each 8 pounds weight in the case of very light, fast machines to one horse-power to 15 or 18 pounds of the total weight in the case of medium speed machines. The development in airplane and power plant design is so rapid, however, that the figures given can be considered only in the light of general averages rather than being typical of current practice. WHY EXPLOSIVE MOTORS ARE BEST Internal combustion engines are best for airplanes and all types of aircraft for the same reasons that they are universally used as a source of power for automobiles. The gasoline engine is the lightest known form of prime mover and a more efficient one than a steam engine, especially in the small powers used for airplane propulsion. It has been stated that by very careful designing a steam plant an engine could be made that would be practical for airplane propulsion, but even with the latest development it is doubtful if steam power can be utilized in aircraft to as good advantage as modern gasoline-engines are. While the steam-engine is considered very much simpler than a gas-motor, the latter is much more easily mastered by the non-technical aviator and certainly requires less attention. A weight of 10 pounds per horse-power is possible in a condensing steam plant but this figure is nearly double or triple what is easily secured with a gas-motor which may weigh but 5 pounds per horse-power in the water cooled forms and but 2 or 3 pounds in the air-cooled types. The fuel consumption is twice as great in a steam-power plant (owing to heat losses) as would be the case in a gasoline engine of equal power and much less weight. The internal-combustion engine has come seemingly like an avalanche of a decade; but it has come to stay, to take its well-deserved position among the powers for aiding labor. Its ready adaptation to road, aerial and marine service has made it a wonder of the age in the development of speed not before dreamed of as a possibility; yet in so short a time, its power for speed has taken rank on the common road against the locomotive on the rail with its century's progress. It has made aerial navigation possible and practical, it furnishes power for all marine craft from the light canoe to the transatlantic liner. It operates the machine tools of the mechanic, tills the soil for the farmer and provides healthful recreation for thousands by furnishing an economical means of transport by land and sea. It has been a universal mechanical education for the masses, and in its present forms represents the great refinement and development made possible by the concentration of the world's master minds on the problems incidental to internal combustion engineering. HISTORICAL Although the ideal principle of explosive power was conceived some two hundred years ago, at which time experiments were made with gunpowder as the explosive element, it was not until the last years of the eighteenth century that the idea took a patentable shape, and not until about 1826 (Brown's gas-vacuum engine) that a further progress was made in England by condensing the products of combustion by a jet of water, thus creating a partial vacuum. Brown's was probably the first explosive engine that did real work. It was clumsy and unwieldy and was soon relegated to its place among the failures of previous experiments. No approach to active explosive effect in a cylinder was reached in practice, although many ingenious designs were described, until about 1838 and the following years. Barnett's engine in England was the first attempt to compress the charge before exploding. From this time on to about 1860 many patents were issued in Europe and a few in the United States for gas-engines, but the progress was slow, and its practical introduction for power came with spasmodic effect and low efficiency. From 1860 on, practical improvement seems to have been made, and the Lenoir motor was produced in France and brought to the United States. It failed to meet expectations, and was soon followed by further improvements in the Hugon motor in France (1862), followed by Beau de Rocha's four-cycle idea, which has been slowly developed through a long series of experimental trials by different inventors. In the hands of Otto and Langdon a further progress was made, and numerous patents were issued in England, France, and Germany, and followed up by an increasing interest in the United States, with a few patents. From 1870 improvements seem to have advanced at a steady rate, and largely in the valve-gear and precision of governing for variable load. The early idea of the necessity of slow combustion was a great drawback in the advancement of efficiency, and the suggestion of de Rocha in 1862 did not take root as a prophetic truth until many failures and years of experience had taught the fundamental axiom that rapidity of action in both combustion and expansion was the basis of success in explosive motors. With this truth and the demand for small and safe prime movers, the manufacture of gas-engines increased in Europe and America at a more rapid rate, and improvements in perfecting the details of this cheap and efficient prime mover have finally raised it to the dignity of a standard motor and a dangerous rival of the steam-engine for small and intermediate powers, with a prospect of largely increasing its individual units to many hundred, if not to the thousand horse-power in a single cylinder. The unit size in a single cylinder has now reached to about 700 horse-power and by combining cylinders in the same machine, powers of from 1,500 to 2,000 horse-power are now available for large power-plants. MAIN TYPES OF INTERNAL-COMBUSTION ENGINES This form of prime mover has been built in so many different types, all of which have operated with some degree of success that the diversity in form will not be generally appreciated unless some attempt is made to classify the various designs that have received practical application. Obviously the same type of engine is not universally applicable, because each class of work has individual peculiarities which can best be met by an engine designed with the peculiar conditions present in view. The following tabular synopsis will enable the reader to judge the extent of the development of what is now the most popular prime mover for all purposes. A. Internal Combustion (Standard Type) 1. Single Acting (Standard Type) 2. Double Acting (For Large Power Only) 3. Simple (Universal Form) 4. Compound (Rarely Used) 5. Reciprocating Piston (Standard Type) 6. Turbine (Revolving Rotor, not fully developed) A1. Two-Stroke Cycle a. Two Port b. Three Port c. Combined Two and Three Port d. Fourth Port Accelerator e. Differential Piston Type f. Distributor Valve System A2. Four-Stroke Cycle a. Automatic Inlet Valve b. Mechanical Inlet Valve c. Poppet or Mushroom Valve d. Slide Valve d 1. Sleeve Valve d 2. Reciprocating Ring Valve d 3. Piston Valve e. Rotary Valves e 1. Disc e 2. Cylinder or Barrel e 3. Single Cone e 4. Double Cone f. Two Piston (Balanced Explosion) g. Rotary Cylinder, Fixed Crank (Aerial) h. Fixed Cylinder, Rotary Crank (Standard Type) A3. Six-Stroke Cycle B. External Combustion (Practically Obsolete) a. Turbine, Revolving Rotor b. Reciprocating Piston CLASSIFICATION BY CYLINDER ARRANGEMENT Single Cylinder a. Vertical b. Horizontal c. Inverted Vertical Double Cylinder a. Vertical b. Horizontal (Side by Side) c. Horizontal (Opposed) d. 45 to 90 Degrees V (Angularly Disposed) e. Horizontal Tandem (Double Acting) Three Cylinder a. Vertical b. Horizontal c. Rotary (Cylinders Spaced at 120 Degrees) d. Radially Placed (Stationary Cylinders) e. One Vertical, One Each Side at an Angle f. Compound (Two High Pressure, One Low Pressure) Four Cylinder a. Vertical b. Horizontal (Side by Side) c. Horizontal (Two Pairs Opposed) d. 45 to 90 Degrees V e. Twin Tandem (Double Acting) Five Cylinder a. Vertical (Five Throw Crankshaft) b. Radially Spaced at 72 Degrees (Stationary) c. Radially Placed Above Crankshaft (Stationary) d. Placed Around Rotary Crankcase (72 Degrees Spacing) Six Cylinder a. Vertical b. Horizontal (Three Pairs Opposed) c. 45 to 90 Degrees V Seven Cylinder a. Equally Spaced (Rotary) Eight Cylinder a. Vertical b. Horizontal (Four Pairs Opposed) c. 45 to 90 Degrees V Nine Cylinder a. Equally Spaced (Rotary) Twelve Cylinder a. Vertical b. Horizontal (Six Pairs Opposed) c. 45 to 90 Degrees V Fourteen Cylinder a. Rotary Sixteen Cylinder a. 45 to 90 Degrees V b. Horizontal (Eight Pairs Opposed) Eighteen Cylinder a. Rotary Cylinder [Illustration: Fig. 2.--Plate Showing Heavy, Slow Speed Internal Combustion Engines Used Only for Stationary Power in Large Installations Giving Weight to Horse-Power Ratio.] [Illustration: Fig. 3.--Various Forms of Internal Combustion Engines Showing Decrease in Weight to Horse-Power Ratio with Augmenting Speed of Rotation.] [Illustration: Fig. 4.--Internal Combustion Engine Types of Extremely Fine Construction and Refined Design, Showing Great Power Outputs for Very Small Weight, a Feature Very Much Desired in Airplane Power Plants.] Of all the types enumerated above engines having less than eight cylinders are the most popular in everything but aircraft work. The four-cylinder vertical is without doubt the most widely used of all types owing to the large number employed as automobile power plants. Stationary engines in small and medium powers are invariably of the single or double form. Three-cylinder engines are seldom used at the present time, except in marine work and in some stationary forms. Eight- and twelve-cylinder motors have received but limited application and practically always in automobiles, racing motor boats or in aircraft. The only example of a fourteen-cylinder motor to be used to any extent is incorporated in aeroplane construction. This is also true of the sixteen- and eighteen-cylinder forms and of twenty-four-cylinder engines now in process of development. The duty an engine is designed for determines the weight per horse-power. High powered engines intended for steady service are always of the slow speed type and consequently are of very massive construction. Various forms of heavy duty type stationary engines are shown at Fig. 2. Some of these engines may weigh as much as 600 pounds per horse-power. A further study is possible by consulting data given on Figs. 3 and 4. As the crank-shaft speed increases and cylinders are multiplied the engines become lighter. While the big stationary power plants may run for years without attention, airplane engines require rebuilding after about 60 to 80 hours air service for the fixed cylinder types and 40 hours or less for the rotary cylinder air-cooled forms. There is evidently a decrease in durability and reliability as the weight is lessened. These illustrations also permit of obtaining a good idea of the variety of forms internal combustion engines are made in. CHAPTER II Operating Principles of Two- and Four-Stroke Engines--Four-cycle Action--Two-cycle Action--Comparing Two- and Four-cycle Types-- Theory of Gas and Gasoline Engine--Early Gas-Engine Forms-- Isothermal Law--Adiabatic Law--Temperature Computations--Heat and Its Work--Conversion of Heat to Power--Requisites for Best Power Effect. OPERATING PRINCIPLES OF TWO- AND FOUR-STROKE CYCLE ENGINES Before discussing the construction of the various forms of internal combustion engines it may be well to describe the operating cycle of the types most generally used. The two-cycle engine is the simplest because there are no valves in connection with the cylinder, as the gas is introduced into that member and expelled from it through ports cored into the cylinder walls. These are covered by the piston at a certain portion of its travel and uncovered at other parts of its stroke. In the four-cycle engine the explosive gas is admitted to the cylinder through a port at the head end closed by a valve, while the exhaust gas is expelled through another port controlled in a similar manner. These valves are operated by mechanism distinct from the piston. [Illustration: Fig. 5.--Outlining First Two Strokes of Piston in Four-Cycle Engine.] The action of the four-cycle type may be easily understood if one refers to illustrations at Figs. 5 and 6. It is called the "four-stroke engine" because the piston must make four strokes in the cylinder for each explosion or power impulse obtained. The principle of the gas-engine of the internal combustion type is similar to that of a gun, i.e., power is obtained by the rapid combustion of some explosive or other quick burning substance. The bullet is driven out of the gun barrel by the pressure of the gas evolved when the charge of powder is ignited. The piston or movable element of the gas-engine is driven from the closed or head end to the crank end of the cylinder by a similar expansion of gases resulting from combustion. The first operation in firing a gun or securing an explosion in the cylinder of the gas-engine is to fill the combustion space with combustible material. This is done by a down stroke of the piston during which time the inlet valve opens to admit the gaseous charge to the cylinder interior. This operation is shown at Fig. 5, A. The second operation is to compress this gas which is done by an upward stroke of the piston as shown at Fig. 5, B. When the top of the compression stroke is reached, the gas is ignited and the piston is driven down toward the open end of the cylinder, as indicated at Fig. 6, C. The fourth operation or exhaust stroke is performed by the return upward movement of the piston as shown at Fig. 6, D during which time the exhaust valve is opened to permit the burnt gases to leave the cylinder. As soon as the piston reaches the top of its exhaust stroke, the energy stored in the fly-wheel rim during the power stroke causes that member to continue revolving and as the piston again travels on its down stroke the inlet valve opens and admits a charge of fresh gas and the cycle of operations is repeated. [Illustration: Fig. 6.--Outlining Second Two Strokes of Piston in Four-Cycle Engine.] [Illustration: Fig. 7.--Sectional View of L Head Gasoline Engine Cylinder Showing Piston Movements During Four-Stroke Cycle.] The illustrations at Fig. 7 show how the various cycle functions take place in an L head type water cooled cylinder engine. The sections at A and C are taken through the inlet valve, those at B and D are taken through the exhaust valve. The two-cycle engine works on a different principle, as while only the combustion chamber end of the piston is employed to do useful work in the four-cycle engine, both upper and lower portions are called upon to perform the functions necessary to two-cycle engine operation. Instead of the gas being admitted into the cylinder as is the case with the four-stroke engine, it is first drawn into the engine base where it receives a preliminary compression prior to its transfer to the working end of the cylinder. The views at Fig. 8 should indicate clearly the operation of the two-port two-cycle engine. At A the piston is seen reaching the top of its stroke and the gas above the piston is being compressed ready for ignition, while the suction in the engine base causes the automatic valve to open and admits mixture from the carburetor to the crank case. When the piston reaches the top of its stroke, the compressed gas is ignited and the piston is driven down on the power stroke, compressing the gas in the engine base. [Illustration: Fig. 8.--Showing Two-port, Two-cycle Engine Operation.] When the top of the piston uncovers the exhaust port the flaming gas escapes because of its pressure. A downward movement of the piston uncovers the inlet port opposite the exhaust and permits the fresh gas to bypass through the transfer passage from the engine base to the cylinder. The conditions with the intake and exhaust port fully opened are clearly shown at Fig. 8, C. The deflector plate on the top of the piston directs the entering fresh gas to the top of the cylinder and prevents the main portion of the gas stream from flowing out through the open exhaust port. On the next upstroke of the piston the gas in the cylinder is compressed and the inlet valve opened, as shown at A to permit a fresh charge to enter the engine base. [Illustration: Fig. 9.--Defining Three-port, Two-cycle Engine Action.] The operating principle of the three-port, two-cycle engine is practically the same as that previously described with the exception that the gas is admitted to the crank-case through a third port in the cylinder wall, which is uncovered by the piston when that member reaches the end of its upstroke. The action of the three-port form can be readily ascertained by studying the diagrams given at Fig. 9. Combination two- and three-port engines have been evolved and other modifications made to improve the action. THE TWO-CYCLE AND FOUR-CYCLE TYPES In the earlier years of explosive-motor progress was evolved the two types of motors in regard to the cycles of their operation. The early attempts to perfect the two-cycle principle were for many years held in abeyance from the pressure of interests in the four-cycle type, until its simplicity and power possibilities were demonstrated by Mr. Dugald Clerk in England, who gave the principles of the two-cycle motor a broad bearing leading to immediate improvements in design, which has made further progress in the United States, until at the present time it has an equal standard value as a motor-power in some applications as its ancient rival the four-cycle or Otto type, as demonstrated by Beau de Rocha in 1862. Thermodynamically, the methods of the two types are equal as far as combustion is concerned, and compression may favor in a small degree the four-cycle type as well as the purity of the charge. The cylinder volume of the two-cycle motor is much smaller per unit of power, and the enveloping cylinder surface is therefore greater per unit of volume. Hence more heat is carried off by the jacket water during compression, and the higher compression available from this tends to increase the economy during compression which is lost during expansion. From the above considerations it may be safely stated that a _lower_ temperature and higher pressure of charge at the beginning of compression is obtained in the two-cycle motor, greater weight of charge and greater specific power of higher compression resulting in higher thermal efficiency. The smaller cylinder for the same power of the two-cycle motor gives less friction surface per impulse than of the other type; although the crank-chamber pressure may, in a measure, balance the friction of the four-cycle type. Probably the strongest points in favor of the two-cycle type are the lighter fly-wheel and the absence of valves and valve gear, making this type the most simple in construction and the lightest in weight for its developed power. Yet, for the larger power units, the four-cycle type will no doubt always maintain the standard for efficiency and durability of action. The distribution of the charge and its degree of mixture with the remains of the previous explosion in the clearance space, has been a matter of discussion for both types of explosive motors, with doubtful results. In Fig. 10, A we illustrate what theory suggests as to the distribution of the fresh charge in a two-cycle motor, and in Fig. 10, B what is the probable distribution of the mixture when the piston starts on its compressive stroke. The arrows show the probable direction of flow of the fresh charge and burnt gases at the crucial moment. [Illustration: Fig. 10.--Diagrams Contrasting Action of Two- and Four-Cycle Cylinders on Exhaust and Intake Stroke.] In Fig. 10, C is shown the complete out-sweep of the products of combustion for the full extent of the piston stroke of a four-cycle motor, leaving only the volume of the clearance to mix with the new charge and at D the manner by which the new charge sweeps by the ignition device, keeping it cool and avoiding possibilities of pre-ignition by undue heating of the terminals of the sparking device. Thus, by enveloping the sparking device with the pure mixture, ignition spreads through the charge with its greatest possible velocity, a most desirable condition in high-speed motors with side-valve chambers and igniters within the valve chamber. THEORY OF THE GAS AND GASOLINE ENGINE The laws controlling the elements that create a power by their expansion by heat due to combustion, when properly understood, become a matter of computation in regard to their value as an agent for generating power in the various kinds of explosive engines. The method of heating the elements of power in explosive engines greatly widens the limits of temperature as available in other types of heat-engines. It disposes of many of the practical troubles of hot-air, and even of steam-engines, in the simplicity and directness of application of the elements of power. In the explosive engine the difficulty of conveying heat for producing expansive effect by convection is displaced by the generation of the required heat within the expansive element and at the instant of its useful work. The low conductivity of heat to and from air has been the great obstacle in the practical development of the hot-air engine; while, on the contrary, it has become the source of economy and practicability in the development of the internal-combustion engine. The action of air, gas, and the vapors of gasoline and petroleum oil, whether singly or mixed, is affected by changes of temperature practically in nearly the same ratio; but when the elements that produce combustion are interchanged in confined spaces, there is a marked difference of effect. The oxygen of the air, the hydrogen and carbon of a gas, or vapor of gasoline or petroleum oil are the elements that by combustion produce heat to expand the nitrogen of the air and the watery vapor produced by the union of the oxygen in the air and the hydrogen in the gas, as well as also the monoxide and carbonic-acid gas that may be formed by the union of the carbon of gas or vapor with part of the oxygen of the air. The various mixtures as between air and gas, or air and vapor, with the proportion of the products of combustion left in the cylinder from a previous combustion, form the elements to be considered in estimating the amount of pressure that may be obtained by their combustion and expansive force. EARLY GAS ENGINE FORMS The working process of the explosive motor may be divided into three principal types: 1. Motors with charges igniting at constant volume without compression, such as the Lenoir, Hugon, and other similar types now abandoned as wasteful in fuel and effect. 2. Motors with charges igniting at constant pressure with compression, in which a receiver is charged by a pump and the gases burned while being admitted to the motor cylinder, such as types of the Simon and Brayton engine. 3. Motors with charges igniting at constant volume with variable compression, such as the later two- and four-cycle motors with compression of the indrawn charge; limited in the two-cycle type and variable in the four-cycle type with the ratios of the clearance space in the cylinder. This principle produces the explosive motor of greatest efficiency. The phenomena of the brilliant light and its accompanying heat at the moment of explosion have been witnessed in the experiments of Dugald Clerk in England, the illumination lasting throughout the stroke; but in regard to time in a four-cycle engine, the incandescent state exists only one-quarter of the running time. Thus the time interval, together with the non-conductibility of the gases, makes the phenomena of a high-temperature combustion within the comparatively cool walls of a cylinder a practical possibility. THE ISOTHERMAL LAW The natural laws, long since promulgated by Boyle, Gay Lussac, and others, on the subject of the expansion and compression of gases by force and by heat, and their variable pressures and temperatures when confined, are conceded to be practically true and applicable to all gases, whether single, mixed, or combined. The law formulated by Boyle only relates to the compression and expansion of gases without a change of temperature, and is stated in these words: _If the temperature of a gas be kept constant, its pressure or elastic force will vary inversely as the volume it occupies._ It is expressed in the formula P × V = C, or pressure × volume = constant. Hence, C/P = V and C/V = P. Thus the curve formed by increments of pressure during the expansion or compression of a given volume of gas without change of temperature is designated as the isothermal curve in which the volume multiplied by the pressure is a constant value in expansion, and inversely the pressure divided by the volume is a constant value in compressing a gas. But as compression and expansion of gases require force for their accomplishment mechanically, or by the application or abstraction of heat chemically, or by convection, a second condition becomes involved, which was formulated into a law of thermodynamics by Gay Lussac under the following conditions: A given volume of gas under a free piston expands by heat and contracts by the loss of heat, its volume causing a proportional movement of a free piston equal to 1/273 part of the cylinder volume for each degree Centigrade difference in temperature, or 1/492 part of its volume for each degree Fahrenheit. With a fixed piston (constant volume), the pressure is increased or decreased by an increase or decrease of heat in the same proportion of 1/273 part of its pressure for each degree Centigrade, or 1/492 part of its pressure for each degree Fahrenheit change in temperature. This is the natural sequence of the law of mechanical equivalent, which is a necessary deduction from the principle that nothing in nature can be lost or wasted, for all the heat that is imparted to or abstracted from a gaseous body must be accounted for, either as heat or its equivalent transformed into some other form of energy. In the case of a piston moving in a cylinder by the expansive force of heat in a gaseous body, all the heat expended in expansion of the gas is turned into work; the balance must be accounted for in absorption by the cylinder or radiation. THE ADIABATIC LAW This theory is equally applicable to the cooling of gases by abstraction of heat or by cooling due to expansion by the motion of a piston. The denominators of these heat fractions of expansion or contraction represent the absolute zero of cold below the freezing-point of water, and read -273° C. or -492.66° = -460.66° F. below zero; and these are the starting-points of reference in computing the heat expansion in gas-engines. According to Boyle's law, called the first law of gases, there are but two characteristics of a gas and their variations to be considered, _viz_., volume and pressure: while by the law of Gay Lussac, called the second law of gases, a third is added, consisting of the value of the absolute temperature, counting from absolute zero to the temperatures at which the operations take place. This is the _Adiabatic_ law. The ratio of the variation of the three conditions--volume, pressure, and heat--from the absolute zero temperature has a certain rate, in which the volume multiplied by the pressure and the product divided by the absolute temperature equals the ratio of expansion for each degree. If a volume of air is contained in a cylinder having a piston and fitted with an indicator, the piston, if moved to and fro slowly, will alternately compress and expand the air, and the indicator pencil will trace a line or lines upon the card, which lines register the change of pressure and volume occurring in the cylinder. If the piston is perfectly free from leakage, and it be supposed that the temperature of the air is kept quite constant, then the line so traced is called an _Isothermal line_, and the pressure at any point when multiplied by the volume is a constant, according to Boyle's law, _pv_ = a constant. If, however, the piston is moved very rapidly, the air will not remain at constant temperature, but the temperature will increase because work has been done upon the air, and the heat has no time to escape by conduction. If no heat whatever is lost by any cause, the line will be traced over and over again by the indicator pencil, the cooling by expansion doing work precisely equalling the heating by compression. This is the line of no transmission of heat, therefore known as _Adiabatic_. [Illustration: Fig. 11.--Diagram Isothermal and Adiabatic Lines.] The expansion of a gas 1/273 of its volume for every degree Centigrade, added to its temperature, is equal to the decimal .00366, the coefficient of expansion for Centigrade units. To any given volume of a gas, its expansion may be computed by multiplying the coefficient by the number of degrees, and by reversing the process the degree of acquired heat may be obtained approximately. These methods are not strictly in conformity with the absolute mathematical formula, because there is a small increase in the increment of expansion of a dry gas, and there is also a slight difference in the increment of expansion due to moisture in the atmosphere and to the vapor of water formed by the union of the hydrogen and oxygen in the combustion chamber of explosive engines. TEMPERATURE COMPUTATIONS The ratio of expansion on the Fahrenheit scale is derived from the absolute temperature below the freezing-point of water (32°) to correspond with the Centigrade scale; therefore 1/492.66 = .0020297, the ratio of expansion from 32° for each degree rise in temperature on the Fahrenheit scale. As an example, if the temperature of any volume of air or gas at constant volume is raised, say from 60° to 2000° F., the increase in temperature will be 1940°. The ratio will be 1/520.66 = .0019206. Then by the formula: Ratio × acquired temp. × initial pressure = the gauge pressure; and .0019206 × 1940° × 14.7 = 54.77 lbs. By another formula, a convenient ratio is obtained by (absolute pressure)/(absolute temp.) or 14.7/520.66 = .028233; then, using the difference of temperature as before, .028233 × 1940° = 54.77 lbs. pressure. By another formula, leaving out a small increment due to specific heat at high temperatures: Atmospheric pressure × absolute temp. + acquired temp. I. -------------------------------------------------------- = Absolute temp. + initial temp. absolute pressure due to the acquired temperature, from which the atmospheric pressure is deducted for the gauge pressure. Using the foregoing example, we have (14.7 × 460.66° + 2000°)/(460.66 + 60°) = 69.47 - 14.7 = 54.77, the gauge pressure, 460.66 being the absolute temperature for zero Fahrenheit. For obtaining the volume of expansion of a gas from a given increment of heat, we have the approximate formula: Volume × absolute temp. + acquired temp. II. ------------------------------------------ = Absolute temp. + initial temp. heated volume. In applying this formula to the foregoing example, the figures become: 460.66° + 2000° I. × ----------------- = 4.72604 volumes. 460.66 + 60° From this last term the gauge pressure may be obtained as follows: III. 4.72604 × 14.7 = 69.47 lbs. absolute - 14.7 lbs. atmospheric pressure = 54.77 lbs. gauge pressure; which is the theoretical pressure due to heating air in a confined space, or at constant volume from 60° to 2000° F. By inversion of the heat formula for absolute pressure we have the formula for the acquired heat, derived from combustion at constant volume from atmospheric pressure to gauge pressure plus atmospheric pressure as derived from Example I., by which the expression absolute pressure × absolute temp. + initial temp. ---------------------------------------------------- initial absolute pressure = absolute temperature + temperature of combustion, from which the acquired temperature is obtained by subtracting the absolute temperature. Then, for example, (69.47 × 460.66 + 60)/14.7 = 2460.66, and 2460.66 - 460.66 = 2000°, the theoretical heat of combustion. The dropping of terminal decimals makes a small decimal difference in the result in the different formulas. HEAT AND ITS WORK By Joule's law of the mechanical equivalent of heat, whenever heat is imparted to an elastic body, as air or gas, energy is generated and mechanical work produced by the expansion of the air or gas. When the heat is imparted by combustion within a cylinder containing a movable piston, the mechanical work becomes an amount measurable by the observed pressure and movement of the piston. The heat generated by the explosive elements and the expansion of the non-combining elements of nitrogen and water vapor that may have been injected into the cylinder as moisture in the air, and the water vapor formed by the union of the oxygen of the air with the hydrogen of the gas, all add to the energy of the work from their expansion by the heat of internal combustion. As against this, the absorption of heat by the walls of the cylinder, the piston, and cylinder-head or clearance walls, becomes a modifying condition in the force imparted to the moving piston. It is found that when any explosive mixture of air and gas or hydrocarbon vapor is fired, the pressure falls far short of the pressure computed from the theoretical effect of the heat produced, and from gauging the expansion of the contents of a cylinder. It is now well known that in practice the high efficiency which is promised by theoretical calculation is never realized; but it must always be remembered that the heat of combustion is the real agent, and that the gases and vapors are but the medium for the conversion of inert elements of power into the activity of energy by their chemical union. The theory of combustion has been the leading stimulus to large expectations with inventors and constructors of explosive motors; its entanglement with the modifying elements in practice has delayed the best development in construction, and as yet no really positive design of best form or action seems to have been accomplished, although great progress has been made during the past decade in the development of speed, reliability, economy, and power output of the individual units of this comparatively new power. One of the most serious difficulties in the practical development of pressure, due to the theoretical computations of the pressure value of the full heat, is probably caused by imparting the heat of the fresh charge to the balance of the previous charge that has been cooled by expansion from the maximum pressure to near the atmospheric pressure of the exhaust. The retardation in the velocity of combustion of perfectly mixed elements is now well known from experimental trials with measured quantities; but the principal difficulty in applying these conditions to the practical work of an explosive engine where a necessity for a large clearance space cannot be obviated, is in the inability to obtain a maximum effect from the imperfect mixture and the mingling of the products of the last explosion with the new mixture, which produces a clouded condition that makes the ignition of the mass irregular or chattering, as observed in the expansion lines of indicator cards; but this must not be confounded with the reaction of the spring in the indicator. Stratification of the mixture has been claimed as taking place in the clearance chamber of the cylinder; but this is not a satisfactory explanation in view of the vortical effect of the violent injection of the air and gas or vapor mixture. It certainly cannot become a perfect mixture in the time of a stroke of a high-speed motor of the two-cycle class. In a four-cycle engine, making 1,500 revolutions per minute, the injection and compression in any one cylinder take place in one twenty-fifth of a second--formerly considered far too short a time for a perfect infusion of the elements of combustion but now very easily taken care of despite the extremely high speed of numerous aviation and automobile power-plants. TABLE I.--EXPLOSION AT CONSTANT VOLUME IN A CLOSED CHAMBER. =====+================================+======+=======+========+====== Dia- | | Temp.| Time | Ob- | Com- gram | | of | of | served |puted Curve| Mixture Injected. |Injec-|Explo- | Gauge |Temp. Fig. | | tion | sion |Pressure|Fahr. 8. | | Fahr.|Second.| Pounds | -----+--------------------------------+------+-------+--------+------ _a_ |1 volume gas to 14 volumes air. | 64° | 0.45 | 40. |1,483° _b_ |1 " " " 13 " " | 51° | 0.31 | 51.5 |1,859° _c_ |1 " " " 12 " " | 51° | 0.24 | 60. |2,195° _d_ |1 " " " 11 " " | 51° | 0.17 | 61. |2,228° _e_ |1 " " " 9 " " | 62° | 0.08 | 78. |2,835° _f_ |1 " " " 7 " " | 62° | 0.06 | 87. |3,151° _g_ |1 " " " 6 " " | 51° | 0.04 | 90. |3,257° _h_ |1 " " " 5 " " | 51° | 0.055 | 91. |3,293° _i_ |1 " " " 4 " " | 66° | 0.16 | 80. |2,871° -----+--------------------------------+------+-------+--------+------ In an examination of the times of explosion and the corresponding pressures in both tables, it will be seen that a mixture of 1 part gas to 6 parts air is the most effective and will give the highest mean pressure in a gas-engine. There is a limit to the relative proportions of illuminating gas and air mixture that is explosive, somewhat variable, depending upon the proportion of hydrogen in the gas. With ordinary coal-gas, 1 of gas to 15 parts of air; and on the lower end of the scale, 1 volume of gas to 2 parts air, are non-explosive. With gasoline vapor the explosive effect ceases at 1 to 16, and a saturated mixture of equal volumes of vapor and air will not explode, while the most intense explosive effect is from a mixture of 1 part vapor to 9 parts air. In the use of gasoline and air mixtures from a carburetor, the best effect is from 1 part saturated air to 8 parts free air. TABLE II.--PROPERTIES AND EXPLOSIVE TEMPERATURE OF A MIXTURE OF ONE PART OF ILLUMINATING GAS OF 660 THERMAL UNITS PER CUBIC FOOT WITH VARIOUS PROPORTIONS OF AIR WITHOUT MIXTURE OF CHARGE WITH THE PRODUCTS OF A PREVIOUS EXPLOSION. [A] Proportion, Air to Gas by Volumes. [B] Pounds in One Cubic Foot of Mixture. [C] Specific Heat. Heat Units Required to Raise 1 Lb. 1 Deg. Fahrenheit. Constant Pressure. [D] Specific Heat. Heat Units Required to Raise 1 Lb. 1 Deg. Fahrenheit. Constant Volume. [E] Heat to Raise One Cubic Foot of Mixture 1 Deg. Fahr. [F] Heat Units Evolved by Combustion. [G] Ratio Col. 6/5 [H] Usual Combustion Efficiency. [I] Usual Rise of Temperature due to Explosion at Constant Volume. =======+========+======+======+========+======+=======+=====+===== [A] | [B] | [C] | [D] | [E] | [F] | [G] | [H] | [I] -------+--------+------+------+--------+------+-------+-----+----- 6 to 1| .074195| .2668| .1913| .014189| 94.28| 6644.6| .465| 3090 7 to 1| .075012| .2628| .1882| .014116| 82. | 5844.4| .518| 3027 8 to 1| .075647| .2598| .1858| .014059| 73.33| 5216.1| .543| 2832 9 to 1| .076155| .2575| .1846| .014013| 66. | 4709.9| .56 | 2637 10 to 1| .076571| .2555| .1825| .013976| 60. | 4293. | .575| 2468 11 to 1| .076917| .2540| .1813| .013945| 55. | 3944. | .585| 2307 12 to 1| .077211| .2526| .1803| .013922| 50.77| 3646.7| .58 | 2115 -------+--------+------+------+--------+------+-------+-----+----- The weight of a cubic foot of gas and air mixture as given in Col. 2 is found by adding the number of volumes of air multiplied by its weight, .0807, to one volume of gas of weight .035 pound per cubic foot and dividing by the total number of volumes; for example, as in the table, 6 × .0807 = .5192/7 = .074195 as in the first line, and so on for any mixture or for other gases of different specific weight per cubic foot. The heat units evolved by combustion of the mixture (Col. 6) are obtained by dividing the total heat units in a cubic foot of gas by the total proportion of the mixture, 660/7 = 94.28 as in the first line of the table. Col. 5 is obtained by multiplying the weight of a cubic foot of the mixture in Col. 2 by the specific heat at a constant volume (Col. 4), Col. 6/Col. 5 = Col. 7 the total heat ratio, of which Col. 8 gives the usual combustion efficiency--Col. 7 × Col. 8 gives the absolute rise in temperature of a pure mixture, as given in Col. 9. The many recorded experiments made to solve the discrepancy between the theoretical and the actual heat development and resulting pressures in the cylinder of an explosive motor, to which much discussion has been given as to the possibilities of dissociation and the increased specific heat of the elements of combustion and non-combustion, as well, also, of absorption and radiation of heat, have as yet furnished no satisfactory conclusion as to what really takes place within the cylinder walls. There seems to be very little known about dissociation, and somewhat vague theories have been advanced to explain the phenomenon. The fact is, nevertheless, apparent as shown in the production of water and other producer gases by the use of steam in contact with highly incandescent fuel. It is known that a maximum explosive mixture of pure gases, as hydrogen and oxygen or carbonic oxide and oxygen, suffers a contraction of one-third their volume by combustion to their compounds, steam or carbonic acid. In the explosive mixtures in the cylinder of a motor, however, the combining elements form so small a proportion of the contents of the cylinder that the shrinkage of their volume amounts to no more than 3 per cent. of the cylinder volume. This by no means accounts for the great heat and pressure differences between the theoretical and actual effects. CONVERSION OF HEAT TO POWER The utilization of heat in any heat-engine has long been a theme of inquiry and experiment with scientists and engineers, for the purpose of obtaining the best practical conditions and construction of heat-engines that would represent the highest efficiency or the nearest approach to the theoretical value of heat, as measured by empirical laws that have been derived from experimental researches relating to its ultimate volume. It is well known that the steam-engine returns only from 12 to 18 per cent. of the power due to the heat generated by the fuel, about 25 per cent. of the total heat being lost in the chimney, the only use of which is to create a draught for the fire; the balance, some 60 per cent., is lost in the exhaust and by radiation. The problem of utmost utilization of force in steam has nearly reached its limit. The internal-combustion system of creating power is comparatively new in practice, and is but just settling into definite shape by repeated trials and modification of details, so as to give somewhat reliable data as to what may be expected from the rival of the steam-engine as a prime mover. For small powers, the gas, gasoline, and petroleum-oil engines are forging ahead at a rapid rate, filling the thousand wants of manufacture and business for a power that does not require expensive care, that is perfectly safe at all times, that can be used in any place in the wide world to which its concentrated fuel can be conveyed, and that has eliminated the constant handling of crude fuel and water. REQUISITES FOR BEST POWER EFFECT The utilization of heat in a gas-engine is mainly due to the manner in which the products entering into combustion are distributed in relation to the movement of the piston. The investigation of the foremost exponent of the theory of the explosive motor was prophetic in consideration of the later realization of the best conditions under which these motors can be made to meet the requirements of economy and practicability. As early as 1862, Beau de Rocha announced, in regard to the coming power, that four requisites were the basis of operation for economy and best effect. 1. The greatest possible cylinder volume with the least possible cooling surface. 2. The greatest possible rapidity of expansion. Hence, _high speed_. 3. The greatest possible expansion. _Long stroke._ 4. The greatest possible pressure at the commencement of expansion. _High compression._ CHAPTER III Efficiency of Internal Combustion Engines--Various Measures of Efficiency--Temperatures and Pressures--Factors Governing Economy--Losses in Wall Cooling--Value of Indicator Cards-- Compression in Explosive Motors--Factors Limiting Compression-- Causes of Heat Losses and Inefficiency--Heat Losses to Cooling Water. EFFICIENCY OF INTERNAL COMBUSTION ENGINES Efficiencies are worked out through intricate formulas for a variety of theoretical and unknown conditions of combustion in the cylinder: ratios of clearance and cylinder volume, and the uncertain condition of the products of combustion left from the last impulse and the wall temperature. But they are of but little value, except as a mathematical inquiry as to possibilities. The real commercial efficiency of a gas or gasoline-engine depends upon the volume of gas or liquid at some assigned cost, required per actual brake horse-power per hour, in which an indicator card should show that the mechanical action of the valve gear and ignition was as perfect as practicable, and that the ratio of clearance, space, and cylinder volume gave a satisfactory terminal pressure and compression: _i.e._, the difference between the power figured from the indicator card and the brake power being the friction loss of the engine. In four-cycle motors of the compression type, the efficiencies are greatly advanced by compression, producing a more complete infusion of the mixture of gas or vapor and air, quicker firing, and far greater pressure than is possible with the two-cycle type previously described. In the practical operation of the gas-engine during the past twenty years, the gas-consumption efficiencies per indicated horse-power have gradually risen from 17 per cent. to a maximum of 40 per cent. of the theoretical heat, and this has been done chiefly through a decreased combustion chamber and increased compression--the compression having gradually increased in practice from 30 lbs. per square inch to above 100; but there seems to be a limit to compression, as the efficiency ratio decreases with greater increase in compression. It has been shown that an ideal efficiency of 33 per cent. for 38 lbs., compression will increase to 40 per cent. for 66 lbs., and 43 per cent. for 88 lbs. compression. On the other hand, greater compression means greater explosive pressure and greater strain on the engine structure, which will probably retain in future practice the compression between the limits of 40 and 90 lbs. except in super-compression engines intended for high altitude work where compression pressures as high as 125 pounds have been used. In experiments made by Dugald Clerk, in England, with a combustion chamber equal to 0.6 of the space swept by the piston, with a compression of 38 lbs., the consumption of gas was 24 cubic feet per indicated horse-power per hour. With 0.4 compression space and 61 lbs. compression, the consumption of gas was 20 cubic feet per indicated horse-power per hour; and with 0.34 compression space and 87 lbs. compression, the consumption of gas fell to 14.8 cubic feet per indicated horse-power per hour--the actual efficiencies being respectively 17, 21, and 25 per cent. This was with a Crossley four-cycle engine. VARIOUS MEASURES OF EFFICIENCY The efficiencies in regard to power in a heat-engine may be divided into four kinds, as follows: I. The first is known as the _maximum theoretical efficiency_ of a perfect engine (represented by the lines in the indicator diagram). It is expressed by the formula (T_{1} - T_{0})/T_{1} and shows the work of a perfect cycle in an engine working between the received temperature + absolute temperature (T_{1}) and the initial atmospheric temperature + absolute temperature (T_{0}). II. The second is the _actual heat efficiency_, or the ratio of the heat turned into work to the total heat received by the engine. It expresses the _indicated horse-power_. III. The third is the ratio between the second or _actual heat efficiency_ and the first or _maximum theoretical efficiency_ of a perfect cycle. It represents the greatest possible utilization of the power of heat in an internal-combustion engine. IV. The fourth is the _mechanical efficiency_. This is the ratio between the actual horse-power delivered by the engine through a dynamometer or measured by a brake (brake horse-power), and the indicated horse-power. The difference between the two is the power lost by engine friction. In regard to the general heat efficiency of the materials of power in explosive engines, we find that with good illuminating gas the practical efficiency varies from 25 to 40 per cent.; kerosene-motors, 20 to 30; gasoline-motors, 20 to 32; acetylene, 25 to 35; alcohol, 20 to 30 per cent. of their heat value. The great variation is no doubt due to imperfect mixtures and variable conditions of the old and new charge in the cylinder; uncertainty as to leakage and the perfection of combustion. In the Diesel motors operating under high pressure, up to nearly 500 pounds, an efficiency of 36 per cent. is claimed. [Illustration: Fig. 12.--Graphic Diagram Showing Approximate Utilization of Fuel Burned in Internal-Combustion Engine.] The graphic diagram at Fig. 12 is of special value as it shows clearly how the heat produced by charge combustion is expended in an engine of average design. On general principles the greater difference between the heat of combustion and the heat at exhaust is the relative measure of the heat turned into work, which represents the degree of efficiency without loss during expansion. The mathematical formulas appertaining to the computation of the element of heat and its work in an explosive engine are in a large measure dependent upon assumed values, as the conditions of the heat of combustion are made uncertain by the mixing of the fresh charge with the products of a previous combustion, and by absorption, radiation, and leakage. The computation of the temperature from the observed pressure may be made as before explained, but for compression-engines the needed starting-points for computation are very uncertain, and can only be approximated from the exact measure and value of the elements of combustion in a cylinder charge. TEMPERATURES AND PRESSURES Owing to the decrease from atmospheric pressure in the indrawing charge of the cylinder, caused by valve and frictional obstruction, the compression seldom starts above 13 lbs. absolute, especially in high-speed engines. Col. 3 in the following table represents the approximate absolute compression pressure for the clearance percentage and ratio in Cols. 1 and 2, while Col. 4 indicates the gauge pressure from the atmospheric line. The temperatures in Col. 5 are due to the compression in Col. 3 from an assumed temperature of 560° F. in the mixture of the fresh charge of 6 air to 1 gas with the products of combustion left in the clearance chamber from the exhaust stroke of a medium-speed motor. This temperature is subject to considerable variation from the difference in the heat-unit power of the gases and vapors used for explosive power, as also of the cylinder-cooling effect. In Col. 6 is given the approximate temperatures of explosion for a mixture of air 6 to gas 1 of 660 heat units per cubic foot, for the relative values of the clearance ratio in Col. 2 at constant volume. TABLE III.--GAS-ENGINE CLEARANCE RATIOS, APPROXIMATE COMPRESSION, TEMPERATURES OF EXPLOSION AND EXPLOSIVE PRESSURES WITH A MIXTURE OF GAS OF 660 HEAT UNITS PER CUBIC FOOT AND MIXTURE OF GAS 1 TO 6 OF AIR. [A] Clearance Per Cent. of Piston Volume. [B] Ratio (_V_/_V_{c}_) = (_P_ + _C_ Vol.)/Clearance [C] Approximate Compression from 13 Pounds Absolute. [D] Approximate Gauge Pressure. [E] Absolute Temperature of Compression from 560 Deg. Fahrenheit in Cylinder. [F] Absolute Temperature of Explosion. Gas, 1 part; Air, 6 parts. [G] Approximate Explosion Pressure Absolute. [H] Approximate Gauge Pressure. [I] Approximate Temperature of Explosion, Fahrenheit. =====+======+======+=====+======+======+=====+=====+===== [A] | [B] | [C] | [D] | [E] | [F] | [G] | [H] | [I] -----+------+------+-----+------+------+-----+-----+----- 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 -----+------+------+-----+------+------+-----+-----+----- | | Lbs. | | Deg. | Deg. |Lbs. |Lbs. | Deg. .50 | 3. | 57. | 42. | 822. | 2488 | 169 | 144 | 2027 .444 | 3.25 | 65. | 50. | 846. | 2568 | 197 | 182 | 2107 .40 | 3.50 | 70. | 55. | 868. | 2638 | 212 | 197 | 2177 .363 | 3.75 | 77. | 62. | 889. | 2701 | 234 | 219 | 2240 .333 | 4. | 84. | 69. | 910. | 2751 | 254 | 239 | 2290 .285 | 4.50 | 102. | 88. | 955. | 2842 | 303 | 288 | 2381 .25 | 5. | 114. | 99. | 983. | 2901 | 336 | 321 | 2440 -----+------+------+-----+------+------+-----+-----+----- FACTORS GOVERNING ECONOMY In view of the experiments in this direction, it clearly shows that in practical work, to obtain the greatest economy per effective brake horse-power, it is necessary: 1st. To transform the heat into work with the greatest rapidity mechanically allowable. This means high piston speed. 2d. To have high initial compression. 3d. To reduce the duration of contact between the hot gases and the cylinder walls to the smallest amount possible; which means short stroke and quick speed, with a spherical cylinder head. 4th. To adjust the temperature of the jacket water to obtain the most economical output of actual power. This means water-tanks or water-coils, with air-cooling surfaces suitable and adjustable to the most economical requirement of the engine, which by late trials requires the jacket water to be discharged at about 200° F. 5th. To reduce the wall surface of the clearance space or combustion chamber to the smallest possible area, in proportion to its required volume. This lessens the loss of the heat of combustion by exposure to a large surface, and allows of a higher mean wall temperature to facilitate the heat of compression. LOSSES IN WALL COOLING In an experimental investigation of the efficiency of a gas-engine under variable piston speeds made in France, it was found that the useful effect increases with the velocity of the piston--that is, with the rate of expansion of the burning gases with mixtures of uniform volumes: so that the variations of time of complete combustion at constant pressure, and the variations due to speed, in a way compensate in their efficiencies. The dilute mixture, being slow burning, will have its time and pressure quickened by increasing the speed. Careful trials give unmistakable evidence that the useful effect increases with the velocity of the piston--that is, with the rate of expansion of the burning gases. The time necessary for the explosion to become complete and to attain its maximum pressure depends not only on the composition of the mixture, but also upon the rate of expansion. This has been verified in experiments with a high-speed motor, at speeds from 500 to 2,000 revolutions per minute, or piston speeds of from 16 to 64 feet per second. The increased speed of combustion due to increased piston speed is a matter of great importance to builders of gas-engines, as well as to the users, as indicating the mechanical direction of improvements to lessen the wearing strain due to high speed and to lighten the vibrating parts with increased strength, in order that the balancing of high-speed engines may be accomplished with the least weight. From many experiments made in Europe and in the United States, it has been conclusively proved that excessive cylinder cooling by the water-jacket results in a marked loss of efficiency. In a series of experiments with a simplex engine in France, it was found that a saving of 7 per cent. in gas consumption per brake horse-power was made by raising the temperature of the jacket water from 141° to 165° F. A still greater saving was made in a trial with an Otto engine by raising the temperature of the jacket water from 61° to 140° F.--it being 9.5 per cent. less gas per brake horse-power. It has been stated that volumes of similar cylinders increase as the cube of their diameters, while the surface of their cold walls varies as the square of their diameters; so that for large cylinders the ratio of surface to volume is less than for small ones. This points to greater economy in the larger engines. The study of many experiments goes to prove that combustion takes place gradually in the gas-engine cylinder, and that the rate of increase of pressure or rapidity of firing is controlled by dilution and compression of the mixture, as well as by the rate of expansion or piston speed. The rate of combustion also depends on the size and shape of the explosion chamber, and is increased by the mechanical agitation of the mixture during combustion, and still more by the mode of firing. VALUE OF INDICATOR CARDS [Illustration: Fig. 13.--Otto Four-Cycle Card.] To the uninitiated, indicator cards are considerable of a mystery; to those capable of reading them they form an index relative to the action of any engine. An indicator card, such as shown at Fig. 13, is merely a graphical representation of the various pressures existing in the cylinder for different positions of the piston. The length is to some scale that represents the stroke of the piston. During the intake stroke, the pressure falls below the atmospheric line. During compression, the curve gradually becomes higher owing to increasing pressure as the volume is reduced. After ignition the pressure line moves upward almost straight, then as the piston goes down on the explosion stroke, the pressure falls gradually to the point of exhaust valve, opening when the sudden release of the imprisoned gas causes a reduction in pressure to nearly atmospheric. An indicator card, or a series of them, will always show by its lines the normal or defective condition of the inlet valve and passages; the actual line of compression; the firing moment; the pressure of explosion; the velocity of combustion; the normal or defective line of expansion, as measured by the adiabatic curve, and the normal or defective operation of the exhaust valve, exhaust passages, and exhaust pipe. In fact, all the cycles of an explosive motor may be made a practical study from a close investigation of the lines of an indicator card. [Illustration: Fig. 14.--Diesel Motor Card.] A most unique card is that of the Diesel motor (Fig. 14), which involves a distinct principle in the design and operation of internal-combustion motors, in that instead of taking a mixed charge for instantaneous explosion, its charge primarily is of air and its compression to a pressure at which a temperature is attained above the igniting point of the fuel, then injecting the fuel under a still higher pressure by which spontaneous combustion takes place gradually with increasing volume over the compression for part of the stroke or until the fuel charge is consumed. The motor thus operating between the pressures of 500 and 35 lbs. per square inch, with a clearance of about 7 per cent., has given an efficiency of 36 per cent. of the total heat value of kerosene oil. COMPRESSION IN EXPLOSIVE MOTORS That the compression in a gas, gasoline, or oil-engine has a direct relation to the power obtained, has been long known to experienced builders, having been suggested by M. Beau de Rocha, in 1862, and afterward brought into practical use in the four-cycle or Otto type about 1880. The degree of compression has had a growth from zero, in the early engines, to the highest available due to the varying ignition temperatures of the different gases and vapors used for explosive fuel, in order to avoid premature explosion from the heat of compression. Much of the increased power for equal-cylinder capacity is due to compression of the charge from the fact that the most powerful explosion of gases, or of any form of explosive material, takes place when the particles are in the closest contact or cohesion with one another, less energy in this form being consumed by the ingredients themselves to bring about their chemical combination, and consequently more energy is given out in useful or available work. This is best shown by the ignition of gunpowder, which, when ignited in the open air, burns rapidly, but without explosion, an explosion only taking place if the powder be confined or compressed into a small space. [Illustration: Fig. 15.--Diagram of Heat in the Gas Engine Cylinder.] In a gas or gasoline-motor with a small clearance or compression space--with high compression--the surface with which the burning gases come into contact is much smaller in comparison with the compression space in a low-compression motor. Another advantage of a high-compression motor is that on account of the smaller clearance of combustion space less cooling water is required than with a low-compression motor, as the temperature, and consequently the pressure, falls more rapidly. The loss of heat through the water-jacket is thus less in the case of a high-compression than in that of a low-compression motor. In the non-compression type of motor the best results were obtained with a charge of 16 to 18 parts of gas and 100 parts of air, while in the compression type the best results are obtained with an explosive mixture of 7 to 10 parts of gas and 100 parts of air, thus showing that by the utilization of compression a weaker charge with a greater thermal efficiency is permissible. It has been found that the explosive pressure resulting from the ignition of the charge of gas or gasoline-vapor and air in the gas-engine cylinder is about 4-1/2 times the pressure prior to ignition. The difficulty about getting high compression is that if the pressure is too high the charge is likely to ignite prematurely, as compression always results in increased temperature. The cylinder may become too hot, a deposit of carbon, a projecting electrode or plug body in the cylinder may become incandescent and ignite the charge which has been excessively heated by the high compression and mixture of the hot gases of the previous explosion. FACTORS LIMITING COMPRESSION With gasoline-vapor and air the compression should not be raised above about 90 to 95 pounds to the square inch, many manufacturers not going above 65 or 70 pounds. For natural gas the compression pressure may easily be raised to from 85 to 100 pounds per square inch. For gases of low calorific value, such as blast-furnace or producer-gas, the compression may be increased to from 140 to 190 pounds. In fact the ability to raise the compression to a high point with these gases is one of the principal reasons for their successful adoption for gas-engine use. In kerosene injection engines the compression of 250 pounds per square inch has been used with marked economy. Many troubles in regard to loss of power and increase of fuel have occurred and will no doubt continue, owing to the wear of valves, piston, and cylinder, which produces a loss in compression and explosive pressure and a waste of fuel by leakage. Faulty adjustment of valve movement is also a cause of loss of power; which may be from tardy closing of the inlet-valve or a too early opening of the exhaust-valve. The explosive pressure varies to a considerable amount in proportion to the compression pressure by the difference in fuel value and the proportions of air mixtures, so that for good illuminating gas the explosive pressure may be from 2.5 to 4 times the compression pressure. For natural gas 3 to 4.5, for gasoline 3 to 5, for producer-gas 2 to 3, and for kerosene by injection 3 to 6. The compression temperatures, although well known and easily computed from a known normal temperature of the explosive mixture, are subject to the effect of the uncertain temperature of the gases of the previous explosion remaining in the cylinder, the temperature of its walls, and the relative volume of the charge, whether full or scant; which are terms too variable to make any computations reliable or available. For the theoretical compression temperatures from a known normal temperature, we append a table of the rise in temperature for the compression pressures in the following table: TABLE IV.--COMPRESSION TEMPERATURES FROM A NORMAL TEMPERATURE OF 60 DEGREES FAHRENHEIT. ===============================+============================== 100 lbs. gauge 484° | 60 lbs. gauge 373° 90 lbs. gauge 459° | 50 lbs. gauge 339° 80 lbs. gauge 433° | 40 lbs. gauge 301° 70 lbs. gauge 404° | 30 lbs. gauge 258° -------------------------------+------------------------------ CHART FOR DETERMINING COMPRESSION PRESSURES A very useful chart (Fig. 16) for determining compression pressures in gasoline-engine cylinders for various ratios of compression space to total cylinder volume is given by P. S. Tice, and described in the Chilton Automobile Directory by the originator as follows: [Illustration: Fig. 16.--Chart Showing Relation Between Compression Volume and Pressure.] It is many times desirable to have at hand a convenient means for at once determining with accuracy what the compression pressure will be in a gasoline-engine cylinder, the relationship between the volume of the compression space and the total cylinder volume or that swept by the piston being known. The curve at Fig. 16 is offered as such a means. It is based on empirical data gathered from upward of two dozen modern automobile engines and represents what may be taken to be the results as found in practice. It is usual for the designer to find compression pressure values, knowing the volumes from the equation P_{2} = P_{1} (V_{1}/V_{2})^{1.4} 1 which is for adiabatic compression of air. Equation (1) is right enough in general form but gives results which are entirely too high, as almost all designers know from experience. The trouble lies in the interchange of heat between the compressed gases and the cylinder walls, in the diminution of the exponent (1.4 in the above) due to the lesser ratio of specific heat of gasoline vapor and in the transfer of heat from the gases which are being compressed to whatever fuel may enter the cylinder in an unvaporized condition. Also, there is always some piston leakage, and, if the form of the equation (1) is to be retained, this also tends to lower the value of the exponent. From experience with many engines, it appears that compression reaches its highest value in the cylinder for but a short range of motor speeds, usually during the mid-range. Also, it appears that, at those speeds at which compression shows its highest values, the initial pressure at the start of the compression stroke is from .5 to .9 lb. below atmospheric. Taking this latter loss value, which shows more often than those of lesser value, the compression is seen to start from an initial pressure of 13.9 lbs. per sq. in. absolute. Also, experiment shows that if the exponent be given the value 1.26, instead of 1.4, the equation will embrace all heat losses in the compressed gas, and compensate for the changed ratio of specific heats for the mixture and also for all piston leakage, in the average engine with rings in good condition and tight. In the light of the foregoing, and in view of results obtained from its use, the above curve is offered--values of P_{2} being found from the equation P_{2} = 13.8 (V_{1}/V_{2})^{1.26} In using this curve it must be remembered that pressures are absolute. Thus: suppose it is desired to know the volumetric relationships of the cylinder for a compression pressure of 75 lbs. gauge. Add atmospheric pressure to the desired gauge pressure 14.7 + 75 = 89.7 lbs. absolute. Locate this pressure on the scale of ordinates and follow horizontally across to the curve and then vertically downward to the scale of abscissas, where the ratio of the combustion chamber volume to the total cylinder volume is given, which latter is equal to the sum of the combustion chamber volume and that of the piston sweep. In the above case it is found that the combustion space for a compression pressure of 75 lbs. gauge will be .225 of the total cylinder volume, or .225 ÷ .775 = .2905 of the piston sweep volume. Conversely, knowing the volumetric ratios, compression pressure can be read directly by proceeding from the scale of abscissas vertically to the curve and thence horizontally to the scale of ordinates. CAUSES OF HEAT LOSS AND INEFFICIENCY IN EXPLOSIVE MOTORS The difference realized in the practical operation of an internal combustion heat engine from the computed effect derived from the values of the explosive elements is probably the most serious difficulty that engineers have encountered in their endeavors to arrive at a rational conclusion as to where the losses were located, and the ways and means of design that would eliminate the causes of loss and raise the efficiency step by step to a reasonable percentage of the total efficiency of a perfect cycle. An authority on the relative condition of the chemical elements under combustion in closed cylinders attributes the variation of temperature shown in the fall of the expansion curve, and the suppression or retarded evolution of heat, entirely to the cooling action of the cylinder walls, and to this nearly all the phenomena hitherto obscure in the cylinder of a gas-engine. Others attribute the great difference between the theoretical temperature of combustion and the actual temperature realized in the practical operation of the gas-engine, a loss of more than one-half of the total heat energy of the combustibles, partly to the dissociation of the elements of combustion at extremely high temperatures and their reassociation by expansion in the cylinder, to account for the supposed continued combustion and extra adiabatic curve of the expansion line on the indicator card. [Illustration: Fig. 17.--The Thompson Indicator, an Instrument for Determining Compressions and Explosion Pressure Values and Recording Them on Chart.] The loss of heat to the walls of the cylinder, piston, and clearance space, as regards the proportion of wall surface to the volume, has gradually brought this point to its smallest ratio in the concave piston-head and globular cylinder-head, with the smallest possible space in the inlet and exhaust passage. The wall surface of a cylindrical clearance space or combustion chamber of one-half its unit diameter in length is equal to 3.1416 square units, its volume but 0.3927 of a cubic unit; while the same wall surface in a spherical form has a volume of 0.5236 of a cubic unit. It will be readily seen that the volume is increased 33-1/3 per cent. in a spherical over a cylindrical form for equal wall surfaces at the moment of explosion, when it is desirable that the greatest amount of heat is generated, and carrying with it the greatest possible pressure from which the expansion takes place by the movement of the piston. [Illustration: Fig. 18.--Spherical Combustion Chamber.] [Illustration: Fig. 19.--Enlarged Combustion Chamber.] The spherical form cannot continue during the stroke for mechanical reasons; therefore some proportion of piston stroke of cylinder volume must be found to correspond with a spherical form of the combustion chamber to produce the least loss of heat through the walls during the combustion and expansion part of the stroke. This idea is illustrated in Figs. 18 and 19, showing how the relative volumes of cylinder stroke and combustion chamber may be varied to suit the requirements due to the quality of the elements of combustion. Although the concave piston-head shows economy in regard to the relation of the clearance volume to the wall area at the moment of explosive combustion, it may be clearly seen that its concavity increases its surface area and its capacity for absorbing heat, for which there is no provision for cooling the piston, save its contact with the walls of the cylinder and the slight air cooling of its back by its reciprocal motion. For this reason the concave piston-head has not been generally adopted and the concave cylinder-head, as shown in Fig. 19, with a flat piston-head is the latest and best practice in airplane engine construction. [Illustration: Fig. 20.--Mercedes Aviation Engine Cylinder Section Showing Approximately Spherical Combustion Chamber and Concave Piston Top.] The practical application of the principle just outlined to one of the most efficient airplane motors ever designed, the Mercedes, is clearly outlined at Fig. 20. HEAT LOSSES TO COOLING WATER The mean temperature of the wall surface of the combustion chamber and cylinder, as indicated by the temperatures of the circulating water, has been found to be an important item in the economy of the gas-engine. Dugald Clerk, in England, a high authority in practical work with the gas-engine, found that 10 per cent. of the gas for a stated amount of power was saved by using water at a temperature in which the ejected water from the cylinder-jacket was near the boiling-point, and ventures the opinion that a still higher temperature for the circulating water may be used as a source of economy. This could be made practical in the case of aviation engines by adjusting the air-cooling surface of the radiator so as to maintain the inlet water at just below the boiling point, and by the rapid circulation induced by the pump pressure, to return the water from the cylinder-jacket a few degrees above the boiling point. The thermal displacement systems of cooling employed in automobiles are working under more favorable temperature conditions than those engines in which cooling is more energetic. For a given amount of heat taken from the cylinder by the largest volume of circulating water, the difference in temperature between inlet and outlet of the water-jacket should be the least possible, and this condition of the water circulation gives a more even temperature to all parts of the cylinder; while, on the contrary, a cold-water supply, say at 60° F., so slow as to allow the ejected water to flow off at a temperature near the boiling-point, must make a great difference in temperature between the bottom and top of the cylinder, with a loss in economy in gas and other fuels, as well as in water, if it is obtained by measurement. From the foregoing considerations of losses and inefficiencies, we find that the practice in motor design and construction has not yet reached the desired perfection in its cycular operation. Step by step improvements have been made with many changes in design though many have been without merit as an improvement, farther than to gratify the longings of designers for something different from the other thing, and to establish a special construction of their own. These efforts may in time produce a motor of normal or standard design for each kind of fuel that will give the highest possible efficiency for all conditions of service. CHAPTER IV Engine Parts and Functions--Why Multiple Cylinder Engines Are Best--Describing Sequence of Operations--Simple Engines--Four and Six Cylinder Vertical Tandem Engines--Eight and Twelve Cylinder V Engines--Radial Cylinder Arrangement--Rotary Cylinder Forms. ENGINE PARTS AND FUNCTIONS The principal elements of a gas engine are not difficult to understand and their functions are easily defined. In place of the barrel of the gun one has a smoothly machined cylinder in which a small cylindrical or barrel-shaped element fitting the bore closely may be likened to a bullet or cannon ball. It differs in this important respect, however, as while the shot is discharged from the mouth of the cannon the piston member sliding inside of the main cylinder cannot leave it, as its movements back and forth from the open to the closed end and back again are limited by simple mechanical connection or linkage which comprises crank and connection rod. It is by this means that the reciprocating movement of the piston is transformed into a rotary motion of the crank-shaft. The fly-wheel is a heavy member attached to the crank-shaft of an automobile engine which has energy stored in its rim as the member revolves, and the momentum of this revolving mass tends to equalize the intermittent pushes on the piston head produced by the explosion of the gas in the cylinder. In aviation engines, the weight of the propeller or that of rotating cylinders themselves performs the duty of a fly-wheel, so no separate member is needed. If some explosive is placed in the chamber formed by the piston and closed end of the cylinder and exploded, the piston would be the only part that would yield to the pressure which would produce a downward movement. As this is forced down the crank-shaft is turned by the connecting rod, and as this part is hinged at both ends it is free to oscillate as the crank turns, and thus the piston may slide back and forth while the crank-shaft is rotating or describing a curvilinear path. [Illustration: Fig. 21.--Side Sectional View of Typical Airplane Engine, Showing Parts and Their Relation to Each Other. This Engine is an Aeromarine Design and Utilizes a Distinctive Concentric Valve Construction.] In addition to the simple elements described it is evident that a gasoline engine must have other parts. The most important of these are the valves, of which there are generally two to each cylinder. One closes the passage connecting to the gas supply and opens during one stroke of the piston in order to let the explosive gas into the combustion chamber. The other member, or exhaust valve, serves as a cover for the opening through which the burned gases can leave the cylinder after their work is done. The spark plug is a simple device which may be compared to the fuse or percussion cap of the cannon. It permits one to produce an electric spark in the cylinder when the piston is at the best point to utilize the pressure which obtains when the compressed gas is fired. The valves are open one at a time, the inlet valve being lifted from its seat while the cylinder is filling and the exhaust valve is opened when the cylinder is being cleared. They are normally kept seated by means of compression springs. In the simple motor shown at Fig. 5, the exhaust valve is operated by means of a pivoted bell crank rocked by a cam which turns at half the speed of the crank-shaft. The inlet valve operates automatically, as will be explained in proper sequence. In order to obtain a perfectly tight combustion chamber, both intake and exhaust valves are closed before the gas is ignited, because all of the pressure produced by the exploding gas is to be directed against the top of the movable piston. When the piston reaches the bottom of its power stroke, the exhaust valve is lifted by means of the bell crank which is rocked because of the point or lift on the cam. The cam-shaft is driven by positive gearing and revolves at half the engine speed. The exhaust valve remains open during the whole of the return stroke of the piston, and as this member moves toward the closed end of the cylinder it forces out burned gases ahead of it, through the passage controlled by the exhaust valve. The cam-shaft is revolved at half the engine speed because the exhaust valve is raised from its seat during only one stroke out of four, or only once every two revolutions. Obviously, if the cam was turned at the same speed as the crank-shaft it would remain open once every revolution, whereas the burned gases are expelled from the individual cylinders only once in two turns of the crank-shaft. WHY MULTIPLE CYLINDER FORMS ARE BEST Owing to the vibration which obtains from the heavy explosion in the large single-cylinder engines used for stationary power other forms were evolved in which the cylinder was smaller and power obtained by running the engine faster, but these are suitable only for very low powers. When a single-cylinder engine is employed a very heavy fly-wheel is needed to carry the moving parts through idle strokes necessary to obtain a power impulse. For this reason automobile and aircraft designers must use more than one cylinder, and the tendency is to produce power by frequently occurring light impulses rather than by a smaller number of explosions having greater force. When a single-cylinder motor is employed the construction is heavier than is needed with a multiple-cylinder form. Using two or more cylinders conduces to steady power generation and a lessening of vibration. Most modern motor cars employ four-cylinder engines because a power impulse may be secured twice every revolution of the crank-shaft, or a total of four power strokes during two revolutions. The parts are so arranged that while the charge of gas in one cylinder is exploding, those which come next in firing order are compressing, discharging the inert gases and drawing in a fresh charge respectively. When the power stroke is completed in one cylinder, the piston in that member in which a charge of gas has just been compressed has reached the top of its stroke and when the gas is exploded the piston is reciprocated and keeps the crank-shaft turning. When a multiple-cylinder engine is used the fly-wheel can be made much lighter than that of the simpler form and eliminated altogether in some designs. In fact, many modern multiple-cylinder engines developing 300 horse-power weigh less than the early single- and double-cylinder forms which developed but one-tenth or one-twentieth that amount of energy. DESCRIBING SEQUENCE OF OPERATIONS Referring to Fig. 22, A, the sequence of operation in a single-cylinder motor can be easily understood. Assuming that the crank-shaft is turning in the direction of the arrow, it will be seen that the intake stroke comes first, then the compression, which is followed by the power impulse, and lastly the exhaust stroke. If two cylinders are used, it is possible to balance the explosions in such a way that one will occur each revolution. This is true with either one of two forms of four-cycle motors. At B, a two-cylinder vertical engine using a crank-shaft in which the crank-pins are on the same plane is shown. The two pistons move up and down simultaneously. Referring to the diagram describing the strokes, and assuming that the outer circle represents the cycle of operations in one cylinder while the inner circle represents the sequence of events in the other cylinder, while cylinder No. 1 is taking in a fresh charge of gas, cylinder No. 2 is exploding. When cylinder No. 1 is compressing, cylinder No. 2 is exhausting. During the time that the charge in cylinder No. 1 is exploded, cylinder No. 2 is being filled with fresh gas. While the exhaust gases are being discharged from cylinder No. 1, cylinder No. 2 is compressing the gas previously taken. [Illustration: Fig. 22.--Diagrams Illustrating Sequence of Cycles in One- and Two-Cylinder Engines Showing More Uniform Turning Effort on Crank-Shaft with Two-Cylinder Motors.] The same condition obtains when the crank-pins are arranged at one hundred and eighty degrees and the cylinders are opposed, as shown at C. The reason that the two-cylinder opposed motor is more popular than that having two vertical cylinders is that it is difficult to balance the construction shown at B, so that the vibration will not be excessive. The two-cylinder opposed motor has much less vibration than the other form, and as the explosions occur evenly and the motor is a simple one to construct, it has been very popular in the past on light cars and has received limited application on some early, light airplanes. To demonstrate very clearly the advantages of multiple-cylinder engines the diagrams at Fig. 23 have been prepared. At A, a three-cylinder motor, having crank-pins at one hundred and twenty degrees, which means that they are spaced at thirds of the circle, we have a form of construction that gives a more even turning than that possible with a two-cylinder engine. Instead of one explosion per revolution of the crank-shaft, one will obtain three explosions in two revolutions. The manner in which the explosion strokes occur and the manner they overlap strokes in the other cylinder is shown at A. Assuming that the cylinders fire in the following order, first No. 1, then No. 2, and last No. 3, we will see that while cylinder No. 1, represented by the outer circle, is on the power stroke, cylinder No. 3 has completed the last two-thirds of its exhaust stroke and has started on its intake stroke. Cylinder No. 2, represented by the middle circle, during this same period has completed its intake stroke and two-thirds of its compression stroke. A study of the diagram will show that there is an appreciable lapse of time between each explosion. Three-cylinder engines are not used on aircraft at the present time, though Bleriot's flight across the British Channel was made with a three-cylinder Anzani motor. It was not a conventional form, however. The three-cylinder engine is practically obsolete at this time for any purpose except "penguins" or school machines that are incapable of flight and which are used in some French training schools for aviators. [Illustration: Fig. 23.--Diagrams Demonstrating Clearly Advantages which Obtain when Multiple-Cylinder Motors are Used as Power Plants.] FOUR- AND SIX-CYLINDER ENGINES In the four-cylinder engine operation which is shown at Fig. 23, B, it will be seen that the power strokes follow each other without loss of time, and one cylinder begins to fire and the piston moves down just as soon as the member ahead of it has completed its power stroke. In a four-cylinder motor, the crank-pins are placed at one hundred and eighty degrees, or on the halves of the crank circle. The crank-pins for cylinders No. 1 and No. 4 are on the same plane, while those for cylinders No. 2 and No. 3 also move in unison. The diagram describing sequence of operations in each cylinder is based on a firing order of one, two, four, three. The outer circle, as in previous instances, represents the cycle of operations in cylinder one. The next one toward the center, cylinder No. 2, the third circle represents the sequence of events in cylinder No. 3, while the inner circle outlines the strokes in cylinder four. The various cylinders are working as follows: 1. 2. 3. 4. Explosion Compression Exhaust Intake Exhaust Explosion Intake Compression Intake Exhaust Compression Explosion Compression Intake Explosion Exhaust It will be obvious that regardless of the method of construction, or the number of cylinders employed, exactly the same number of parts must be used in each cylinder assembly and one can conveniently compare any multiple-cylinder power plant as a series of single-cylinder engines joined one behind the other and so coupled that one will deliver power and produce useful energy at the crank-shaft where the other leaves off. The same fundamental laws governing the action of a single cylinder obtain when a number are employed, and the sequence of operation is the same in all members, except that the necessary functions take place at different times. If, for instance, all the cylinders of a four-cylinder motor were fired at the same time, one would obtain the same effect as though a one-piston engine was used, which had a piston displacement equal to that of the four smaller members. As is the case with a single-cylinder engine, the motor would be out of correct mechanical balance because all the connecting rods would be placed on crank-pins that lie in the same plane. A very large fly-wheel would be necessary to carry the piston through the idle strokes, and large balance weights would be fitted to the crank-shaft in an effort to compensate for the weight of the four pistons, and thus reduce vibratory stresses which obtain when parts are not in correct balance. There would be no advantage gained by using four cylinders in this manner, and there would be more loss of heat and more power consumed in friction than in a one-piston motor of the same capacity. This is the reason that when four cylinders are used the arrangement of crank-pins is always as shown at Fig. 23, B--i.e., two pistons are up, while the other two are at the bottom of the stroke. With this construction, we have seen that it is possible to string out the explosions so that there will always be one cylinder applying power to the crank-shaft. The explosions are spaced equally. The parts are in correct mechanical balance because two pistons are on the upstroke while the other two are descending. Care is taken to have one set of moving members weigh exactly the same as the other. With a four-cylinder engine one has correct balance and continuous application of energy. This insures a smoother running motor which has greater efficiency than the simpler one-, two-, and three-cylinder forms previously described. Eliminating the stresses which would obtain if we had an unbalanced mechanism and irregular power application makes for longer life. Obviously a large number of relatively light explosions will produce less wear and strain than would a lesser number of powerful ones. As the parts can be built lighter if the explosions are not heavy, the engine can be operated at higher rotative speeds than when large and cumbersome members are utilized. Four-cylinder engines intended for aviation work have been built according to the designs shown at Fig. 24, but these forms are unconventional and seldom if ever used. [Illustration: Fig. 24.--Showing Three Possible Though Unconventional Arrangements of Four-Cylinder Engines.] The six-cylinder type of motor, the action of which is shown at Fig. 23, C, is superior to the four-cylinder, inasmuch as the power strokes overlap, and instead of having two explosions each revolution we have three explosions. The conventional crank-shaft arrangement in a six-cylinder engine is just the same as though one used two three-cylinder shafts fastened together, so pistons 1 and 6 are on the same plane as are pistons 2 and 5. Pistons 3 and 4 also travel together. With the cranks arranged as outlined at Fig. 23, C, the firing order is one, five, three, six, two, four. The manner in which the power strokes overlap is clearly shown in the diagram. An interesting comparison is also made in the diagrams at Fig. 25 and in the upper corner of Fig. 23, C. [Illustration: Fig. 25.--Diagrams Outlining Advantages of Multiple Cylinder Motors, and Why They Deliver Power More Evenly Than Single Cylinder Types.] A rectangle is divided into four columns; each of these corresponds to one hundred and eighty degrees, or half a revolution. Thus the first revolution of the crank-shaft is represented by the first two columns, while the second revolution is represented by the last two. Taking the portion of the diagram which shows the power impulse in a one-cylinder engine, we see that during the first revolution there has been no power impulse. During the first half of the second revolution, however, an explosion takes place and a power impulse is obtained. The last portion of the second revolution is devoted to exhausting the burned gases, so that there are three idle strokes and but one power stroke. The effect when two cylinders are employed is shown immediately below. [Illustration: Fig. 26.--Diagrams Showing Duration of Events for a Four-Stroke Cycle, Six-Cylinder Engine.] Here we have one explosion during the first half of the first revolution in one cylinder and another during the first half of the second revolution in the other cylinder. With a four-cylinder engine there is an explosion each half revolution, while in a six-cylinder engine there is one and one-half explosions during each half revolution. When six cylinders are used there is no lapse of time between power impulses, as these overlap and a continuous and smooth-turning movement is imparted to the crank shaft. The diagram shown at Fig. 26, prepared by E. P. Pulley, can be studied to advantage in securing an idea of the coordination of effort that takes place in an engine of the six-cylinder type. ACTUAL DURATION OF DIFFERENT STROKES [Illustration: Fig. 27.--Diagram Showing Actual Duration of Different Strokes in Degrees.] In the diagrams previously presented the writer has assumed, for the sake of simplicity, that each stroke takes place during half of one revolution of the crank-shaft, which corresponds to a crank-pin travel of one hundred and eighty degrees. The actual duration of these strokes is somewhat different. For example, the inlet stroke is usually a trifle more than a half revolution, and the exhaust is always considerably more. The diagram showing the comparative duration of the strokes is shown at Fig. 27. The inlet valve opens ten degrees after the piston starts to go down and remains open thirty degrees after the piston has reached the bottom of its stroke. This means that the suction stroke corresponds to a crank-pin travel of two hundred degrees, while the compression stroke is measured by a movement of but one hundred and fifty degrees. It is common practice to open the exhaust valve before the piston reaches the end of the power stroke so that the actual duration of the power stroke is about one hundred and forty degrees, while the exhaust stroke corresponds to a crank-pin travel of two hundred and twenty-five degrees. In this diagram, which represents proper time for the valves to open and close, the dimensions in inches given are measured on the fly-wheel and apply only to a certain automobile motor. If the fly-wheel were smaller ten degrees would take up less than the dimensions given, while if the fly-wheel was larger a greater space on its circumference would represent the same crank-pin travel. Aviation engines are timed by using a timing disc attached to the crank-shaft as they are not provided with fly-wheels. Obviously, the distance measured in inches will depend upon the diameter of the disc, though the number of degrees interval would not change. [Illustration: Fig. 28.--Another Diagram to Facilitate Understanding Sequence of Functions in Six-Cylinder Engine.] EIGHT- AND TWELVE-CYLINDER V ENGINES Those who have followed the development of the gasoline engine will recall the arguments that were made when the six-cylinder motor was introduced at a time that the four-cylinder type was considered standard. The arrival of the eight-cylinder has created similar futile discussion of its practicability as this is so clearly established as to be accepted without question. It has been a standard power plant for aeroplanes for many years, early exponents having been the Antoinette, the Woolsley, the Renault, the E. N. V. in Europe and the Curtiss in the United States. [Illustration: Fig. 29.--Types of Eight-Cylinder Engines Showing the Advantage of the V Method of Cylinder Placing.] The reason the V type shown at Fig. 29, A is favored is that the "all-in-line form" which is shown at Fig. 29, B is not practical for aircraft because of its length. Compared to the standard four-cylinder engine it is nearly twice as long and it required a much stronger and longer crank-shaft. It will be evident that it could not be located to advantage in the airplane fuselage. These undesirable factors are eliminated in the V type eight-cylinder motor, as it consists of two blocks of four cylinders each, so arranged that one set or block is at an angle of forty-five degrees from the vertical center line of the motor, or at an angle of ninety degrees with the other set. This arrangement of cylinders produces a motor that is no longer than a four-cylinder engine of half the power would be. [Illustration: Fig. 30.--Curves Showing Torque of Various Engine Types Demonstrate Graphically Marked Advantage of the Eight-Cylinder Type.] Apparently there is considerable misconception as to the advantage of the two extra cylinders of the eight as compared with the six-cylinder. It should be borne in mind that the multiplication in the number of cylinders noticed since the early days of automobile development has not been for solely increasing the power of the engine, but to secure a more even turning movement, greater flexibility and to eliminate destructive vibration. The ideal internal combustion motor, is the one having the most uniform turning movement with the least mechanical friction loss. Study of the torque outlines or plotted graphics shown at Figs. 25 and 30 will show how multiplication of cylinders will produce steady power delivery due to overlapping impulses. The most practical form would be that which more nearly conforms to the steady running produced by a steam turbine or electric motor. The advocates of the eight-cylinder engine bring up the item of uniform torque as one of the most important advantages of the eight-cylinder design. A number of torque diagrams are shown at Fig. 30. While these appear to be deeply technical, they may be very easily followed when their purpose is explained. At the top is shown the torque diagram of a single-cylinder motor of the four-cycle type. The high point in the line represents the period of greatest torque or power generation, and it will be evident that this occurs early in the first revolution of the crank-shaft. Below this diagram is shown a similar curve except that it is produced by a four-cylinder engine. Inspection will show that the turning-moment is much more uniform than in the single cylinder; similarly, the six-cylinder diagram is an improvement over the four, and the eight-cylinder diagram is an improvement over the six-cylinder. [Illustration: Fig. 31.--Diagrams Showing How Increasing Number of Cylinders Makes for More Uniform Power Application.] The reason that practically continuous torque is obtained in an eight-cylinder engine is that one cylinder fires every ninety degrees of crank-shaft rotation, and as each impulse lasts nearly seventy-five per cent. of the stroke, one can easily appreciate that an engine that will give four explosions per revolution of the crank-shaft will run more uniformly than one that gives but three explosions per revolution, as the six-cylinder does, and will be twice as smooth running as a four-cylinder, in which but two explosions occur per revolution of the crank-shaft. The comparison is so clearly shown in graphical diagrams and in Fig. 31 that further description is unnecessary. Any eight-cylinder engine may be considered a "twin-four," twelve-cylinder engines may be considered "twin sixes." [Illustration: Fig. 32.--How the Angle Between the Cylinders of an Eight- and Twelve-Cylinder V Motor Varies.] The only points in which an eight-cylinder motor differs from a four-cylinder is in the arrangement of the connecting rod, as in many designs it is necessary to have two rods working from the same crank-pin. This difficulty is easily overcome in some designs by staggering the cylinders and having the two connecting rod big ends of conventional form side by side on a common crank-pin. In other designs one rod is a forked form and works on the outside of a rod of the regular pattern. Still another method is to have a boss just above the main bearing on one connecting rod to which the lower portion of the connecting rod in the opposite cylinder is hinged. As the eight-cylinder engine may actually be made lighter than the six-cylinder of equal power, it is possible to use smaller reciprocating parts, such as pistons, connecting rods and valve gear, and obtain higher engine speed with practically no vibration. The firing order in nearly every case is the same as in a four-cylinder except that the explosions occur alternately in each set of cylinders. The firing order of an eight-cylinder motor is apt to be confusing to the motorist, especially if one considers that there are eight possible sequences. The majority of engineers favor the alternate firing from side to side. Firing orders will be considered in proper sequence. [Illustration: Fig. 33.--The Hall-Scott Four-Cylinder 100 Horse-Power Aviation Motor.] [Illustration: Fig. 34.--Two Views of the Duesenberg Sixteen Valve Four-Cylinder Aviation Motor.] The demand of aircraft designers for more power has stimulated designers to work out twelve-cylinder motors. These are high-speed motors incorporating all recent features of design in securing light reciprocating parts, large valve openings, etc. The twelve-cylinder motor incorporates the best features of high-speed motor design and there is no need at this time to discuss further the pros and cons of the twelve-cylinder versus the eight or six, because it is conceded by all that there is the same degree of steady power application in the twelve over the eight as there would be in the eight over the six. The question resolves itself into having a motor of high power that will run with minimum vibration and that produces smooth action. This is well shown by diagrams at Fig. 31. It should be remembered that if an eight-cylinder engine will give four explosions per revolution of the fly-wheel, a twelve-cylinder type will give six explosions per revolution, and instead of the impulses coming 90 degrees crank travel apart, as in the case of the eight-cylinder, these will come but 60 degrees of crank travel apart in the case of the twelve-cylinder. For this reason, the cylinders of a twelve are usually separated by 60 degrees while the eight has the blocks spaced 90 degrees apart. The comparison can be easily made by comparing the sectional views of Vee engines at Fig. 32. When one realizes that the actual duration of the power stroke is considerably greater than 120 degrees crank travel, it will be apparent that the overlapping of explosions must deliver a very uniform application of power. Vee engines have been devised having the cylinders spaced but 45 degrees apart, but the explosions cannot be timed at equal intervals as when 90 degrees separate the cylinder center lines. [Illustration: Fig. 35.--The Hall-Scott Six-Cylinder Aviation Engine.] RADIAL CYLINDER ARRANGEMENTS [Illustration: Fig. 36.--The Curtiss Eight-Cylinder, 200 Horse-Power Aviation Engine.] While the fixed cylinder forms of engines, having the cylinders in tandem in the four- and six-cylinder models as shown at Figs. 33 to 35 inclusive and the eight-cylinder V types as outlined at Figs. 36 and 37 have been generally used and are most in favor at the present time, other forms of motors having unconventional cylinder arrangements have been devised, though most of these are practically obsolete. While many methods of decreasing weight and increasing mechanical efficiency of a motor are known to designers, one of the first to be applied to the construction of aeronautical power plants was an endeavor to group the components, which in themselves were not extremely light, into a form that would be considerably lighter than the conventional design. As an example, we may consider those multiple-cylinder forms in which the cylinders are disposed around a short crank-case, either radiating from a common center as at Fig. 38 or of the fan shape shown at Fig. 39. This makes it possible to use a crank-case but slightly larger than that needed for one or two cylinders and it also permits of a corresponding decrease in length of the crank-shaft. The weight of the engine is lessened because of the reduction in crank-shaft and crank-case weight and the elimination of a number of intermediate bearings and their supporting webs which would be necessary with the usual tandem construction. While there are six power impulses to every two revolutions of the crank-shaft, in the six-cylinder engine, they are not evenly spaced as is possible with the conventional arrangement. [Illustration: Fig. 37.--The Sturtevant Eight-Cylinder, High Speed Aviation Motor.] [Illustration: Fig. 38.--Anzani 40-50 Horse-Power Five-Cylinder Air Cooled Engine.] In the Anzani form, which is shown at Fig. 38, the crank-case is stationary and a revolving crank-shaft is employed as in conventional construction. The cylinders are five in number and the engine develops 40 to 50 H.P. with a weight of 72 kilograms or 158.4 lbs. The cylinders are of the usual air-cooled form having cooling flanges only part of the way down the cylinder. By using five cylinders it is possible to have the power impulses come regularly, they coming 145° crank-shaft travel apart, the crank-shaft making two turns to every five explosions. The balance is good and power output regular. The valves are placed directly in the cylinder head and are operated by a common pushrod. Attention is directed to the novel method of installing the carburetor which supplies the mixture to the engine base from which inlet pipes radiate to the various cylinders. This engine is used on French school machines. [Illustration: Fig. 39.--Unconventional Six-Cylinder Aircraft Motor of Masson Design.] In the form shown at Fig. 39 six cylinders are used, all being placed above the crank-shaft center line. This engine is also of the air-cooled form and develops 50 H. P. and weighs 105 kilograms, or 231 lbs. The carburetor is connected to a manifold casting attached to the engine base from which the induction pipes radiate to the various cylinders. The propeller design and size relative to the engine is clearly shown in this view. While flights have been made with both of the engines described, this method of construction is not generally followed and has been almost entirely displaced abroad by the revolving motors or by the more conventional eight-cylinder V engines. Both of the engines shown were designed about eight years ago and would be entirely too small and weak for use in modern airplanes intended for active duty. ROTARY ENGINES [Illustration: Fig. 40.--The Gnome Fourteen-Cylinder Revolving Motor.] Rotary engines such as shown at Fig. 40 are generally associated with the idea of light construction and it is rather an interesting point that is often overlooked in connection with the application of this idea to flight motors, that the reason why rotary engines are popularly supposed to be lighter than the others is because they form their own fly-wheel, yet on aeroplanes, engines are seldom fitted with a fly-wheel at all. As a matter of fact the Gnome engine is not so light because it is a rotary motor, and it is a rotary motor because the design that has been adopted as that most conducive to lightness is also most suited to an engine working in this way. The cylinders could be fixed and crank-shaft revolve without increasing the weight to any extent. There are two prime factors governing the lightness of an engine, one being the initial design, and the other the quality of the materials employed. The consideration of reducing weight by cutting away metal is a subsidiary method that ought not to play a part in standard practice, however useful it may be in special cases. In the Gnome rotary engine the lightness is entirely due to the initial design and to the materials employed in manufacture. Thus, in the first case, the engine is a radial engine, and has its seven or nine cylinders spaced equally around a crank-chamber that is no wider or rather longer than would be required for any one of the cylinders. This shortening of the crank-chamber not only effects a considerable saving of weight on its own account, but there is a corresponding saving in the shafts and other members, the dimensions of which are governed by the size of the crank-chamber. With regard to materials, nothing but steel is used throughout, and most of the metal is forged chrome nickel steel. The beautifully steady running of the engine is largely due to the fact that there are literally no reciprocating parts in the absolute sense, the apparent reciprocation between the pistons and cylinders being solely a relative reciprocation since both travel in circular paths, that of the pistons, however, being electric by one-half of the stroke length to that of the cylinder. While the Gnome engine has many advantages, on the other hand the head resistance offered by a motor of this type is considerable; there is a large waste of lubricating oil due to the centrifugal force which tends to throw the oil away from the cylinders; the gyroscopic effect of the rotary motor is detrimental to the best working of the aeroplane, and moreover it requires about seven per cent. of the total power developed by the motor to drive the revolving cylinders around the shaft. Of necessity, the compression of this type of motor is rather low, and an additional disadvantage manifests itself in the fact that there is as yet no satisfactory way of muffling the rotary type of motor. The modern Gnome engine has been widely copied in various European countries, but its design was originated in America, the early Adams-Farwell engine being the pioneer form. It has been made in seven- and nine-cylinder types and forms of double these numbers. The engine illustrated at Fig. 40 is a fourteen-cylinder form. The simple engines have an odd number of cylinders in order to secure evenly spaced explosions. In the seven-cylinder, the impulses come 102.8° apart. In the nine-cylinder form, the power strokes are spaced 80° apart. The fourteen-cylinder engine is virtually two seven-cylinder types mounted together, the cranks being just the same as in a double cylinder opposed motor, the explosions coming 51.4° apart; while in the eighteen-cylinder model the power impulses come every 40° cylinder travel. Other rotary motors have been devised, such as the Le Rhone and the Clerget in France and several German copies of these various types. The mechanical features of these motors will be fully considered later. CHAPTER V Properties of Liquid Fuels--Distillates of Crude Petroleum-- Principles of Carburetion Outlined--Air Needed to Burn Gasoline --What a Carburetor Should Do--Liquid Fuel Storage and Supply-- Vacuum Fuel Feed--Early Vaporizer Forms--Development of Float Feed Carburetor--Maybach's Early Design--Concentric Float and Jet Type--Schebler Carburetor--Claudel Carburetor--Stewart Metering Pin Type--Multiple Nozzle Vaporizers--Two-Stage Carburetor--Master Multiple Jet Type--Compound Nozzle Zenith Carburetor--Utility of Gasoline Strainers--Intake Manifold Design and Construction--Compensating for Various Atmospheric Conditions--How High Altitude Affects Power--The Diesel System-- Notes on Carburetor Installation--Notes on Carburetor Adjustment. There is no appliance that has more material value upon the efficiency of the internal combustion motor than the carburetor or vaporizer which supplies the explosive gas to the cylinders. It is only in recent years that engineers have realized the importance of using carburetors that are efficient and that are so strongly and simply made that there will be little liability of derangement. As the power obtained from the gas-engine depends upon the combustion of fuel in the cylinders, it is evident that if the gas supplied does not have the proper proportions of elements to insure rapid combustion the efficiency of the engine will be low. When a gas engine is used as a stationary installation it is possible to use ordinary illuminating or natural gas for fuel, but when this prime mover is applied to automobiles or airplanes it is evident that considerable difficulty would be experienced in carrying enough compressed coal gas to supply the engine for even a very short trip. Fortunately, the development of the internal-combustion motor was not delayed by the lack of suitable fuel. Engineers were familiar with the properties of certain liquids which gave off vapors that could be mixed with air to form an explosive gas which burned very well in the engine cylinders. A very small quantity of such liquids would suffice for a very satisfactory period of operation. The problem to be solved before these liquids could be applied in a practical manner was to evolve suitable apparatus for vaporizing them without waste. Among the liquids that can be combined with air and burned, gasoline is the most volatile and is the fuel utilized by internal-combustion engines. The widely increasing scope of usefulness of the internal-combustion motor has made it imperative that other fuels be applied in some instances because the supply of gasoline may in time become inadequate to supply the demand. In fact, abroad this fuel sells for fifty to two hundred per cent. more than it does in America because most of the gasoline used must be imported from this country or Russia. Because of this foreign engineers have experimented widely with other substances, such as alcohol, benzol, and kerosene, but more to determine if they can be used to advantage in motor cars than in airplane engines. DISTILLATES OF CRUDE PETROLEUM Crude petroleum is found in small quantities in almost all parts of the world, but a large portion of that produced commercially is derived from American wells. The petroleum obtained in this country yields more of the volatile products than those of foreign production, and for that reason the demand for it is greater. The oil fields of this country are found in Pennsylvania, Indiana, and Ohio, and the crude petroleum is usually in association with natural gas. This mineral oil is an agent from which many compounds and products are derived, and the products will vary from heavy sludges, such as asphalt, to the lighter and more volatile components, some of which will evaporate very easily at ordinary temperatures. The compounds derived from crude petroleum are composed principally of hydrogen and carbon and are termed "Hydrocarbons." In the crude product one finds many impurities, such as free carbon, sulphur, and various earthy elements. Before the oil can be utilized it must be subjected to a process of purifying which is known as refining, and it is during this process, which is one of destructive distillation, that the various liquids are separated. The oil was formerly broken up into three main groups of products as follows: Highly volatile, naphtha, benzine, gasoline, eight to ten per cent. Light oils, such as kerosene and light lubricating oils seventy to eighty per cent. Heavy oils or residuum five to nine per cent. From the foregoing it will be seen that the available supply of gasoline is determined largely by the demand existing for the light oils forming the larger part of the products derived from crude petroleum. New processes have been recently discovered by which the lighter oils, such as kerosene, are reduced in proportion and that of gasoline increased, though the resulting liquid is neither the high grade, volatile gasoline known in the early days of motoring nor the low grade kerosene. PRINCIPLES OF CARBURETION OUTLINED The process of carburetion is combining the volatile vapors which evaporate from the hydrocarbon liquids with certain proportions of air to form an inflammable gas. The quantities of air needed vary with different liquids and some mixtures burn quicker than do other combinations of air and vapor. Combustion is simply burning and it may be rapid, moderate or slow. Mixtures of gasoline and air burn quickly, in fact the combustion is so rapid that it is almost instantaneous and we obtain what is commonly termed an "explosion." Therefore the explosion of gas in the automobile engine cylinder which produces the power is really a combination of chemical elements which produce heat and an increase in the volume of the gas because of the increase in temperature. If the gasoline mixture is not properly proportioned the rate of burning will vary, and if the mixture is either too rich or too weak the power of the explosion is reduced and the amount of power applied to the piston is decreased proportionately. In determining the proper proportions of gasoline and air, one must take the chemical composition of gasoline into account. The ordinary liquid used for fuel is said to contain about eight-four per cent. carbon and sixteen per cent. hydrogen. Air is composed of oxygen and nitrogen and the former has a great affinity, or combining power, with the two constituents of hydrocarbon liquids. Therefore, what we call an explosion is merely an indication that oxygen in the air has combined with the carbon and hydrogen of the gasoline. AIR NEEDED TO BURN GASOLINE In figuring the proper volume of air to mix with a given quantity of fuel, one takes into account the fact that one pound of hydrogen requires eight pounds of oxygen to burn it, and one pound of carbon needs two and one-third pounds of oxygen to insure its combustion. Air is composed of one part of oxygen to three and one-half portions of nitrogen by weight. Therefore for each pound of oxygen one needs to burn hydrogen or carbon four and one-half pounds of air must be allowed. To insure combustion of one pound of gasoline which is composed of hydrogen and carbon we must furnish about ten pounds of air to burn the carbon and about six pounds of air to insure combustion of hydrogen, the other component of gasoline. This means that to burn one pound of gasoline one must provide about sixteen pounds of air. While one does not usually consider air as having much weight, at a temperature of sixty-two degrees Fahrenheit about fourteen cubic feet of air will weigh a pound, and to burn a pound of gasoline one would require about two hundred cubic feet of air. This amount will provide for combustion theoretically, but it is common practice to allow twice this amount because the element nitrogen, which is the main constituent of air, is an inert gas and instead of aiding combustion it acts as a deterrent of burning. In order to be explosive, gasoline vapor must be combined with definite quantities of air. Mixtures that are rich in gasoline ignite quicker than those which have more air, but these are only suitable when starting or when running slowly, as a rich mixture ignites much quicker than a weak mixture. The richer mixture of gasoline and air not only burns quicker but produces the most heat and the most effective pressure in pounds per square inch of piston top area. The amount of compression of the charge before ignition also has material bearing on the force of the explosion. The higher the degree of compression the greater the force exerted by the rapid combustion of the gas. It may be stated that as a general thing the maximum explosive pressure is somewhat more than four times the compression pressure prior to ignition. A charge compressed to sixty pounds will have a maximum of approximately two hundred and forty pounds; compacted to eighty pounds it will produce a pressure of about three hundred pounds on each square inch of piston area at the beginning of the power stroke. Mixtures varying from one part of gasoline vapor to four of air to others having one part of gasoline vapor to thirteen of air can be ignited, but the best results are obtained when the proportions are one to five or one to seven, as this mixture is said to be the one that will produce the highest temperature, the quickest explosion, and the most pressure. WHAT A CARBURETOR SHOULD DO While it is apparent that the chief function of a carbureting device is to mix hydrocarbon vapors with air to secure mixtures that will burn, there are a number of factors which must be considered before describing the principles of vaporizing devices. Almost any device which permits a current of air to pass over or through a volatile liquid will produce a gas which will explode when compressed and ignited in the motor cylinder. Modern carburetors are not only called upon to supply certain quantities of gas, but these must deliver a mixture to the cylinders that is accurately proportioned and which will be of proper composition at all engine speeds. [Illustration: Fig. 41.--How Gravity Feed Fuel Tank May Be Mounted Back of Engine and Secure Short Fuel Line.] Flexible control of the engine is sought by varying the engine speed by regulating the supply of gas to the cylinders. The power plant should run from its lowest to its highest speed without any irregularity in torque, i.e., the acceleration should be gradual rather than spasmodic. As the degree of compression will vary in value with the amount of throttle opening, the conditions necessary to obtain maximum power differ with varying engine speeds. When the throttle is barely opened the engine speed is low and the gas must be richer in fuel than when the throttle is wide open and the engine speed high. When an engine is turning over slowly the compression has low value and the conditions are not so favorable to rapid combustion as when the compression is high. At high engine speeds the gas velocity through the intake piping is higher than at low speeds, and regular engine action is not so apt to be disturbed by condensation of liquid fuel in the manifold due to excessively rich mixture or a superabundance of liquid in the stream of carbureted air. LIQUID FUEL STORAGE AND SUPPLY The problem of gasoline storage and method of supplying the carburetor is one that is determined solely by design of the airplane. While the object of designers should be to supply the fuel to the carburetor by as simple means as possible the fuel supply system of some airplanes is quite complex. The first point to consider is the location of the gasoline tank. This depends upon the amount of fuel needed and the space available in the fuselage. A very simple and compact fuel supply system is shown at Fig. 41. In this instance the fuel container is placed immediately back of the engine cylinder. The carburetor which is carried as indicated is joined to the tank by a short piece of copper or flexible rubber tubing. This is the simplest possible form of fuel supply system and one used on a number of excellent airplanes. As the sizes of engines increase and the power plant fuel consumption augments it is necessary to use more fuel, and to obtain a satisfactory flying radius without frequent landings for filling the fuel tank it is necessary to supply large containers. When a very powerful power plant is fitted, as on battle planes of high capacity, it is necessary to carry large quantities of gasoline. In order to use a tank of sufficiently large capacity it may be necessary to carry it lower than the carburetor. When installed in this manner it is necessary to force fuel out of the tank by air pressure or to pump it with a vacuum tank because the gasoline tank is lower than the carburetor it supplies and the gasoline cannot flow by gravity as in the simpler systems. While the pressure and gravity feed systems are generally used in airplanes, it may be well to describe the vacuum lift system which has been widely applied to motor cars and which may have some use in connection with airplanes as these machines are developed. STEWART VACUUM FUEL FEED One of the marked tendencies has been the adoption of a vacuum fuel feed system to draw the gasoline from tanks placed lower than the carburetor instead of using either exhaust gas or air pressure to achieve this end. The device generally fitted is the Stewart vacuum feed tank which is clearly shown in section at Fig. 42. In this system the suction of a motor is employed to draw gasoline from the main fuel tank to the auxiliary tank incorporated in the device and from this tank the liquid flows to the carburetor. It is claimed that all the advantages of the pressure system are obtained with very little more complication than is found on the ordinary gravity feed. The mechanism is all contained in the cylindrical tank shown, which may be mounted either on the front of the dash or on the side of the engine as shown. [Illustration: Fig. 42.--The Stewart Vacuum Fuel Feed Tank.] The tank is divided into two chambers, the upper one being the filling chamber and the lower one the emptying chamber. The former, which is at the top of the device, contains the float valve, as well as the pipes running to the main fuel container and to the intake manifold. The lower chamber is used to supply the carburetor with gasoline and is under atmospheric pressure at all times, so the flow of fuel from it is by means of gravity only. Since this chamber is located somewhat above the carburetor, there must always be free flow of fuel. Atmospheric pressure is maintained by the pipes A and B, the latter opening into the air. In order that the fuel will be sucked from a main tank to the upper chamber, the suction valve must be opened and the atmospheric valve closed. Under these conditions the float is at the bottom and the suction at the intake manifold produces a vacuum in the tank which draws the gasoline from the main tank to the upper chamber. When the upper chamber is filled at the proper height the float rises to the top, this closing the suction valve and opening the atmospheric valve. As the suction is now cut off, the lower chamber is filled by gravity owing to there being atmospheric pressure in both upper and lower chambers. A flap valve is provided between the two chambers to prevent the gasoline in the lower one from being sucked back into the upper one. The atmospheric and suction valves are controlled by the levers C and D, both of which are pivoted at E, their outer ends being connected by two coil springs. It is seen that the arrangement of these two springs is such that the float must be held at the extremity of its movement, and that it cannot assume an intermediate position. This intermittent action is required to insure that the upper part of the tank may be under atmospheric pressure part of the time for the gasoline to flow to the lower chamber. When the level of gasoline drops to a certain point, the float falls, thus opening the suction valve and closing the atmospheric valve. The suction of the motor then causes a flow of fuel from the main container. As soon as the level rises to the proper height the float returns to its upper position. It takes about two seconds for the chamber to become full enough to raise the float, as but .05 gallon is transferred at a time. The pipe running from the bottom of the lower chamber to the carburetor extends up a ways, so that there is but little chance of dirt or water being carried to the float chamber. If the engine is allowed to stand long enough so that the tank becomes empty, it will be replenished after the motor has been cranked over four or five times with the throttle closed. The installation of the Stewart Vacuum-Gravity System is very simple. The suction pipe is tapped into the manifold at a point as near the cylinders as possible, while the fuel pipe is inserted into the gasoline tank and runs to the bottom of that member. There is a screen at the end of the fuel pipe to prevent any trouble due to deposits of sediment in the main container. As the fuel is sucked from the gasoline tank a small vent must be made in the tank filler cap so that the pressure in the main tank will always be that of the atmosphere. EARLY VAPORIZER FORMS The early types of carbureting devices were very crude and cumbersome, and the mixture of gasoline vapor and air was accomplished in three ways. The air stream was passed over the surface of the liquid itself, through loosely placed absorbent material saturated with liquid, or directly through the fuel. The first type is known as the surface carburetor and is now practically obsolete. The second form is called the "wick" carburetor because the air stream was passed over or through saturated wicking. The third form was known as a "bubbling" carburetor. While these primitive forms gave fairly good results with the early slow-speed engines and the high grade, or very volatile, gasoline which was first used for fuel, they would be entirely unsuitable for present forms of engines because they would not carburate the lower grades of gasoline which are used to-day, and would not supply the modern high-speed engines with gas of the proper consistency fast enough even if they did not have to use very volatile gasoline. The form of carburetor used at the present time operates on a different principle. These devices are known as "spraying carburetors." The fuel is reduced to a spray by the suction effect of the entering air stream drawing it through a fine opening. The advantage of this construction is that a more thorough amalgamation of the gasoline and air particles is obtained. With the earlier types previously considered the air would combine with only the more volatile elements, leaving the heavier constituents in the tank. As the fuel became stale it was difficult to vaporize it, and it had to be drained off and fresh fuel provided before the proper mixture would be produced. It will be evident that when the fuel is sprayed into the air stream, all the fuel will be used up and the heavier portions of the gasoline will be taken into the cylinder and vaporized just as well as the more volatile vapors. [Illustration: Fig. 43.--Marine-Type Mixing Valve, by which Gasoline is Sprayed into Air Stream Through Small Opening in Air-Valve Seat.] The simplest form of spray carburetor is that shown at Fig. 43. In this the gasoline opening through which the fuel is sprayed into the entering air stream is closed by the spring-controlled mushroom valve which regulates the main air opening as well. When the engine draws in a charge of air it unseats the valve and at the same time the air flowing around it is saturated with gasoline particles through the gasoline opening. The mixture thus formed goes to the engine through the mixture passage. Two methods of varying the fuel proportions are provided. One of these consists of a needle valve to regulate the amount of gasoline, the other is a knurled screw which controls the amount of air by limiting the lift of the jump valve. DEVELOPMENT OF FLOAT-FEED CARBURETOR The modern form of spraying carburetor is provided with two chambers, one a mixing chamber through which the air stream passes and mixes with a gasoline spray, the other a float chamber in which a constant level of fuel is maintained by simple mechanism. A jet or standpipe is used in the mixing chamber to spray the fuel through and the object of the float is to maintain the fuel level to such a point that it will not overflow the jet when the motor is not drawing in a charge of gas. With the simple forms of generator valve in which the gasoline opening is controlled by the air valve, a leak anywhere in either valve or valve seat will allow the gasoline to flow continuously whether the engine is drawing in a charge or not. The liquid fuel collects around the air opening, and when the engine inspires a charge it is saturated with gasoline globules and is excessively rich. With a float-feed construction, which maintains a constant level of gasoline at the right height in the standpipe, liquid fuel will only be supplied when drawn out of the jet by the suction effect of the entering air stream. MAYBACH'S EARLY DESIGN The first form of spraying carburetor ever applied successfully was evolved by Maybach for use on one of the earliest Daimler engines. The general principles of operation of this pioneer float-feed carburetor are shown at Fig. 44, A. The mixing chamber and valve chamber were one and the standpipe or jet protruded into the mixing chamber. It was connected to the float compartment by a pipe. The fuel from the tank entered the top of the float compartment and the opening was closed by a needle valve carried on top of a hollow metal float. When the level of gasoline in the float chamber was lowered the float would fall and the needle valve uncover the opening. This would permit the gasoline from the tank to flow into the float chamber, and as the chamber filled the float would rise until the proper level had been reached, under which conditions the float would shut off the gasoline opening. On every suction stroke of the engine the inlet valve, which was an automatic type, would leave its seat and a stream of air would be drawn through the air opening and around the standpipe or jet. This would cause the gasoline to spray out of the tube and mix with the entering air stream. [Illustration: Fig. 44.--Tracing Evolution of Modern Spray Carburetor. A--Early Form Evolved by Maybach. B.--Phoenix-Daimler Modification of Maybach's Principle. C--Modern Concentric Float Automatic Compensating Carburetor.] The form shown at B was a modification of Maybach's simple device and was first used on the Phoenix-Daimler engines. Several improvements are noted in this device. First, the carburetor was made one unit by casting the float and mixing chambers together instead of making them separate and joining them by a pipe, as shown at A. The float construction was improved and the gasoline shut-off valve was operated through leverage instead of being directly fastened to the float. The spray nozzle was surrounded by a choke tube which concentrated the air stream around it and made for more rapid air flow at low engine speeds. A conical piece was placed over the jet to break up the entering spray into a mist and insure more intimate admixture of air and gasoline. The air opening was provided with an air cone which had a shutter controlling the opening so that the amount of air entering could be regulated and thus vary the mixture proportions within certain limits. CONCENTRIC FLOAT AND JET TYPE The form shown at B has been further improved, and the type shown at C is representative of modern single jet practice. In this the float chamber and mixing chamber are concentric. A balanced float mechanism which insures steadiness of feed is used, the gasoline jet or standpipe is provided with a needle valve to vary the amount of gasoline supplied the mixture and two air openings are provided. The main air port is at the bottom of the vaporizer, while an auxiliary air inlet is provided at the side of the mixing chamber. There are two methods of controlling the mixture proportions in this form of carburetor. One may regulate the gasoline needle or adjust the auxiliary air valve. SCHEBLER CARBURETOR A Schebler carburetor, which has been used on some airplane engines, is shown in Fig. 45. It will be noticed that a metering pin or needle valve opens the jet when the air valve opens. The long arm of a leverage is connected to the air valve, while the short arm is connected to the needle, the reduction in leverage being such that the needle valve is made to travel much less than the air valve. For setting the amount of fuel passed or the size of the jet orifice when running with the air valve closed, there is a screw which raises or lowers the fulcrum of the lever and there is also a dash control having the same effect by pushing down the fulcrum against a small spring. A long extension is given to the venturi tube which is very narrow around the jet orifices, which are horizontal and shown at A in the drawing. Fuel enters the float chamber through the union M, and the spring P holds the metering pin upward against the restraining action of the lever. The air valve may be set by an easily adjustable knurled screw shown in the drawing, and fluttering of the valve is prevented by the piston dash pot carried in a chamber above the valve into which the valve stem projects. The primary air enters beneath the jet passage and there is a small throttle in the intake to increase the speed of air flow for starting purposes. The carburetor is adapted for the use of a hot-air connection to the stove around the exhaust pipe and it is recommended that such a fitting be supplied. The lever which controls the supply of air through the primary air intake is so arranged that if desired it can be connected with a linkage on the dash or control column by means of a flexible wire. [Illustration: Fig. 45.--New Model of Schebler Carburetor With Metering Valve and Extended Venturi. Note Mechanical Connection Between Air Valve and Fuel Regulating Needle.] THE CLAUDEL (FRENCH) CARBURETOR [Illustration: Fig. 46.--The Claudel Carburetor.] This carburetor is of extremely simple construction, because it has no supplementary or auxiliary air valve and no moving parts except the throttle controlling the gas flow. The construction is already shown in Fig. 46. The spray jet is eccentric with a surrounding sleeve or tube in which there are two series of small orifices, one at the top and the other near the bottom. The former are about level with the spray jet opening. The sleeve surrounding the nozzle is closed at the top. The air, passing the upper holes in the sleeve, produces a vacuum in the sleeve, thereby drawing air in through the bottom holes. It is this moving interior column of air that controls the flow of gasoline from the nozzle. Owing to the friction of the small passages, the speed of air flow through the sleeve does not increase as fast as the speed of air flow outside the sleeve, hence there is a tendency for the mixture to remain constant. The throttle of this carburetor is of the barrel type, and the top of the spray nozzle and its surrounding sleeve are located inside the throttle. STEWART METERING PIN CARBURETOR The carburetor shown at Fig. 47 is a metering type in which the vacuum at the jet is controlled by the weight of the metering valve surrounding the upright metering pin. The only moving part is the metering valve, which rises and falls with the changes in vacuum. The air chamber surrounds the metering valve, and there is a mixing chamber above. As the valve is drawn up the gasoline passage is enlarged on account of the predetermined taper on the metering pin, and the air passage also is increased proportionately, giving the correct mixture. A dashpot at the bottom of the valve checks flutter. In idling the valve rests on its seat, practically closing the air and giving the necessary idling mixture. A passage through the valve acts as an aspirating tube. When the valve is closed altogether the primary air passes through ducts in the valve itself, giving the proper amount for idling. The one adjustment consists in raising or lowering the tapered metering pin, increasing or decreasing the supply of gasoline. Dash control is supplied. This pulls down the metering pin, increasing the gasoline flow. The duplex type for eight- and twelve-cylinder motors is the same in principle as model 25, but it is a double carburetor synchronized as to throttle movements, adjustments, etc. The duplex for aeronautical motors is made of cast aluminum alloy. [Illustration: Fig. 47.--The Stewart Metering Pin Carburetor.] MULTIPLE NOZZLE VAPORIZERS To secure properly proportioned mixtures some carburetor designers have evolved forms in which two or more nozzles are used in a common mixing chamber. The usual construction is to use two, one having a small opening and placed in a small air tube and used only for low speeds, the other being placed in a larger air tube and having a slightly augmented bore so that it is employed on intermediate speeds. At high speeds both jets would be used in series. Some multiple jet carburetors could be considered as a series of these instruments, each one being designed for certain conditions of engine action. They would vary from small size just sufficient to run the engine at low speed to others having sufficient capacity to furnish gas for the highest possible engine speed when used in conjunction with the smaller members which have been brought into service progressively as the engine speed has been augmented. The multiple nozzle carburetor differs from that in which a single spray tube is used only in the construction of the mixing chamber, as a common float bowl can be used to supply all spray pipes. It is common practice to bring the jets into action progressively by some form of mechanical connection with the throttle or by automatic valves. The object of any multiple nozzle carburetor is to secure greater flexibility and endeavor to supply mixtures of proper proportions at all speeds of the engine. It should be stated, however, that while devices of this nature lend themselves readily to practical application it is more difficult to adjust them than the simpler forms having but one nozzle. When a number of jets are used the liability of clogging up the carburetor is increased, and if one or more of the nozzles is choked by a particle of dirt or water the resulting mixture trouble is difficult to detect. One of the nozzles may supply enough gasoline to permit the engine to run well at certain speeds and yet not be adequate to supply the proper amount of gas under other conditions. In adjusting a multiple jet carburetor in which the jets are provided with gasoline regulating needles, it is customary to consider each nozzle as a distinct carburetor and to regulate it to secure the best motor action at that throttle position which corresponds to the conditions under which the jet is brought into service. For instance, that supplied the primary mixing chamber should be regulated with the throttle partly closed, while the auxiliary jet should be adjusted with the throttle fully opened. BALL AND BALL TWO-STAGE CARBURETOR [Illustration: Fig. 48.--The Ball and Ball Two-Stage Carburetor.] This is a two-stage vaporizing device, hot air being used in the primary or initial stage of vaporization and cold air in the supplementary stage. Referring to the sectional illustration at Fig. 48, it will be seen that there is a hot-air passage with a choke-valve; the primary venturi appears at B; J is its gasoline jet, and V is a spring-loaded idling valve in a fixed air opening. These parts constitute the primary system. In the secondary system A is a cold-air passage, T a butterfly valve and J a gasoline jet discharging into the cold-air passage. This system is brought into operation by opening the butterfly T. A connection between the butterfly T and the throttle, not shown, throws the butterfly wide open when the throttle is not quite wide open; at all other times the butterfly is held closed by a spring. The cylindrical chamber at the right of the mixing chamber has an extension E of reduced diameter connecting it with the intake manifold through a passage D. A restricted opening connects the float chamber with the cylindrical chamber so that the gasoline level is the same in both. A loosely fitting plunger P in the cylindrical chamber has an upward extension into the small part of the chamber. O is a small air opening and M is a passage from the cylindrical chamber to the mixing chamber. Air constantly passes through this when the carburetor is in operation. The carburetor is really two in one. The primary carburetor is made up of a central jet in a venturi passage. The float chamber is eccentric. In the air passage there is a fixed opening, and additional air is taken in by the opening through suction of a spring-opposed air valve. The second stage, which comes into play as soon as the carburetor is called upon for additional mixture above low medium speeds, is made up of an independent air passage containing another air valve. As the valve is opened this jet is uncovered, and air is led past it. For easy starting an extra passage leads from the float bowl passage to a point above the throttle. All the suction falls upon this passage when the throttle is closed. The passage contains a plunger and acts as a pick-up device. When the vacuum increases the plunger rises and shuts off the flow of gasoline from the intake passage. As the throttle is opened the vacuum in the intake passage is broken, and the plunger falls, causing gasoline to gather above it. This is immediately drawn through the pick-up passage and gives the desired mixture for acceleration. MASTER MULTIPLE-JET CARBURETOR [Illustration: Fig. 49.--The Master Carburetor.] This carburetor, shown in detail in Figs. 49 and 50, has been very popular in racing cars and aviation engines because of exceptionally good pick-up qualities and its thorough atomization of fuel. Its principle of operation is the breaking up of the fuel by a series of jets, which vary in number from fourteen to twenty-one, according to the size of the carburetor. These are uncovered by opening the throttle, which is curved--a patented feature--to secure the correct progression of jets. The carburetor has an eccentric float chamber, from which the gasoline is led to the jet piece from which the jets stand up in a row. The tops of these jets are closed until the throttle is opened far enough to pass them, which it does progressively. The air opening is at the bottom, and the throttle opening is such that a modified venturi is formed. The throttle is carried in a cylindrical barrel with the jets placed below it, and the passage from the barrel to the intake is arranged so that there is no interruption in the flow. For easy starting a dash-controlled shutter closes off the air, throwing the suction on the jets, thus giving a rich mixture. [Illustration: Fig. 50.--Sectional View of Master Carburetor Showing Parts.] The only adjustment is for idling, and once that is fixed it need never be touched. This is in the form of a screw and regulates the position of the throttle when at idling position. The dash control has high-speed, normal and rich-starting positions. In installing the Master carburetor the float chamber may be turned either toward the radiator or driver's seat. If the float is turned toward the radiator, however, a forward lug plate should be ordered; otherwise it will be difficult to install the control. The throttle lever must go all the way to the stop lug or maximum power will not be secured. In adjusting the idle screw it is turned in for rich and out for lean. COMPOUND NOZZLE ZENITH CARBURETOR [Illustration: Fig. 51.--Sectional View of Zenith Compound Nozzle Compensating Carburetor.] The Zenith carburetor, shown at Fig. 51, has become very popular for airplane engine use because of its simplicity, as mixture compensation is secured by a compensating compound nozzle principle that works very well in practice. To illustrate this principle briefly, let us consider the elementary type of carburetor or mixing valve, as shown in Fig. 52, A. It consists of a single jet or spraying nozzle placed in the path of the incoming air and fed from the usual float chamber. It is a natural inference to suppose that as the speed of the motor increases, both the flow of air and of gasoline will increase in the same proportion. Unhappily, such is not the case. There is a law of liquid bodies which states that the flow of gasoline from the jet increases under suction faster than the flow of air, giving a mixture which grows richer and richer--a mixture containing a much higher percentage of gasoline at high suction than at low. The tendency is shown by the accompanying curve (Fig. 52, B), which gives the ratio of gasoline to air at varying speeds from this type of jet. The mixture is practically constant only between narrow limits and at very high speed. The most common method of correcting this defect is by putting various auxiliary air valves which, adding air, tends to dilute this mixture as it gets too rich. It is difficult with makeshift devices to gauge this dilution accurately for every motor speed. [Illustration: Fig. 52.--Diagrams Explaining Action of Baverey Compound Nozzle Used in Zenith Carburetor.] Now, if we have a jet which grows richer as the suction increases, the opposite type of jet is one which would grow leaner under similar conditions. Baverey, the inventor of the Zenith, discovered the principle of the constant flow device which is shown in Fig. 52, C. Here a certain fixed amount of gasoline determined by the opening I is permitted to flow by gravity into the well J open to the air. The suction at jet H has no effect upon the gravity compensator I because the suction is destroyed by the open well J. The compensator, then, delivers a steady rate of flow per unit of time, and as the motor suction increases more air is drawn up, while the amount of gasoline remains the same and the mixture grows poorer and poorer. Fig. 52, D, shows this curve. By combining these two types of rich and poor mixture carburetors the Zenith compound nozzle was evolved. In Fig. 52, E, we have both the direct suction or richer type leading through pipe E and nozzle G and the "constant flow" device of Baverey shown at J, I, K and nozzle H. One counteracts the defects of the other, so that from the cranking of the motor to its highest speed there is a constant ratio of air and gasoline to supply efficient combustion. In addition to the compound nozzle the Zenith is equipped with a starting and idling well, shown in the cut of Model L carburetor at P and J. This terminates in a priming hole at the edge of the butterfly valve, where the suction is greatest when this valve is slightly open. The gasoline is drawn up by the suction at the priming hole and, mixed with the air rushing by the butterfly, gives an ideal slow speed mixture. At higher speeds with the butterfly valve opened further the priming well ceases to operate and the compound nozzle drains the well and compensates correctly for any motor speed. [Illustration: Fig. 53.--The Zenith Duplex Carburetor for Airplane Motors of the V Type.] With the coming of the double motor containing eight or twelve cylinders arranged in two V blocks, the question of good carburetion has been a problem requiring much study. The single carburetor has given only indifferent results due to the strong cross suction in the inlet manifold from one set of cylinders to the other. This naturally led to the adoption of two carburetors in which each set of cylinders was independently fed by a separate carburetor. Results from this system were very good when the two carburetors were working exactly in unison, but as it was extremely difficult to accomplish this co-operation, especially where the adjustable type was employed, this system never gained in favor. The next logical step was the Zenith Duplex, shown at Fig. 53. This consists of two separate and distinct carburetors joined together so that a common gasoline float chamber and air inlet could be used by both. It does away with cross suction in the manifold because each set of cylinders has a separate intake of its own. It does away with two carburetors and makes for simplicity. The practical application of the Zenith carburetor to the Curtiss 90 horse-power OX-2 motor used on the JN-4 standard training machine is shown at Fig. 54, which outlines a rear view of the engine in question. The carburetor is carried low to permit of fuel supply from a gravity tank carried back of the motor. [Illustration: Fig. 54.--Rear View of Curtiss OX-2 90 Horse-Power Airplane Motor Showing Carburetor Location and Hot Air Leads.] UTILITY OF GASOLINE STRAINERS Many carburetors include a filtering screen at the point where the liquid enters the float chamber in order to keep dirt or any other foreign matter which may be present in the fuel from entering the float chamber. This is not general practice, however, and the majority of vaporizers do not include a filter in their construction. It is very desirable that the dirt should be kept out of the carburetor because it may get under the float control fuel valve and cause flooding by keeping it raised from its seat. If it finds its way into the spray nozzle it may block the opening so that no gasoline will issue or may so constrict the passage that only very small quantities of fuel will be supplied the mixture. Where the carburetor itself is not provided with a filtering screen a simple filter is usually installed in the pipe line between the gasoline tank and the float chamber. Some simple forms of filters and separators are shown at Fig. 55. That at A consists of a simple brass casting having a readily detachable gauze screen and a settling chamber of sufficient capacity to allow the foreign matter to settle to the bottom, from which it is drained out by a pet cock. Any water or dirt in the gasoline will settle to the bottom of the chamber, and as all fuel delivered to the carburetor must pass through the wire gauze screen it is not likely to contain impurities when it reaches the float chamber. The heavier particles, such as scale from the tank or dirt and even water, all of which have greater weight than the gasoline, will sink to the bottom of the chamber, whereas light particles, such as lint, will be prevented from flowing into the carburetor by the filtering screen. [Illustration: Fig. 55.--Types of Strainers Interposed Between Vaporizer and Gasoline Tank to Prevent Water or Dirt Passing Into Carbureting Device.] The filtering device shown at B is a larger appliance than that shown at A, and should be more efficient as a separator because the gasoline is forced to pass through three filtering screens before it reaches the carburetor. The gasoline enters the device shown at C through a bent pipe which leads directly to the settling chamber and from thence through a wire gauze screen to the upper compartment which leads to the carburetor. The device shown at D is a combination strainer, drain, and sediment cup. The filtering screen is held in place by a spring and both are removed by taking out a plug at the bottom of the device. The shut-off valve at the top of the device is interposed between the sediment cup and the carburetor. This separating device is incorporated with the gasoline tank and forms an integral part of the gasoline supply system. The other types shown are designed to be interposed between the gasoline tank and the carburetor at any point in the pipe line where they may be conveniently placed. INTAKE MANIFOLD DESIGN AND CONSTRUCTION On four- and six-cylinder engines and in fact on all multiple-cylinder forms, it is important that the piping leading from the carburetor to the cylinders be made in such a way that the various cylinders will receive their full quota of gas and that each cylinder will receive its charge at about the same point in the cycle of operations. In order to make the passages direct the bends should be as few as possible, and when curves are necessary they should be of large radius because an abrupt corner will not only impede gas flow but will tend to promote condensation of the fuel. Every precaution should be taken with four- and six-cylinder engines to insure equitable gas distribution to the valve chambers if regular action of the power plant is desired. If the gas pipe has many turns and angles it will be difficult to charge all cylinders properly. On some six-cylinder aviation engines, two carburetors are used because of trouble experienced with manifolds designed for one carburetor. Duplex carburetors are necessary to secure the best results from eight- and twelve-cylinder V engines. The problem of intake piping is simplified to some extent on block motors where the intake passage is cored in the cylinder casting and where but one short pipe is needed to join this passage to the carburetor. If the cylinders are cast in pairs a simple pipe of T or Y form can be used with success. When the engine is of a type using individual cylinder castings, especially in the six-cylinder power plants, the proper application and installation of suitable piping is a difficult problem. The reader is referred to the various engine designs outlined to ascertain how the inlet piping has been arranged on representative aviation engines. Intake piping is constructed in two ways, the most common method being to cast the manifold of brass or aluminum. The other method, which is more costly, is to use a built-up construction of copper or brass tubing with cast metal elbows and Y pieces. One of the disadvantages advanced against the cast manifold is that blowholes may exist which produce imperfect castings and which will cause mixture troubles because the entering gas from the carburetor, which may be of proper proportions, is diluted by the excess air which leaks in through the porous casting. Another factor of some moment is that the roughness of the walls has a certain amount of friction which tends to reduce the velocity of the gases, and when projecting pieces are present, such as core wire or other points of metal, these tend to collect the drops of liquid fuel and thus promote condensation. The advantage of the built-up construction is that the walls of the tubing are very smooth, and as the castings are small it is not difficult to clean them out thoroughly before they are incorporated in the manifold. The tubing and castings are joined together by hard soldering, brazing or autogenous welding. COMPENSATING FOR VARYING ATMOSPHERIC CONDITIONS The low-grade gasoline used at the present time makes it necessary to use vaporizers that are more susceptible to atmospheric variations than when higher grade and more volatile liquids are vaporized. Sudden temperature changes, sometimes being as much as forty degrees rise or fall in twelve hours, affect the mixture proportions to some extent, and not only changes in temperature but variations in altitude also have a bearing on mixture proportions by affecting both gasoline and air. As the temperature falls the specific gravity of the gasoline increases and it becomes heavier, this producing difficulty in vaporizing. The tendency of very cold air is to condense gasoline instead of vaporizing it and therefore it is necessary to supply heated air to some carburetors to obtain proper mixtures during cold weather. In order that the gas mixtures will ignite properly the fuel must be vaporized and thoroughly mixed with the entering air either by heat or high velocity of the gases. The application of air stoves to the Curtiss OX-2 motor is clearly shown at Fig. 54. It will be seen that flexible metal pipes are used to convey the heated air to the air intakes of the duplex mixing chamber. [Illustration: Fig. 56.--Chart Showing Diminution of Air Pressure as Altitude Increases.] HOW HIGH ALTITUDE AFFECTS POWER Any internal combustion engine will show less power at high altitudes than it will deliver at sea level, and this has caused a great deal of questioning. "There is a good reason for this," says a writer in "Motor Age," "and it is a physical impossibility for the engine to do otherwise. The difference is due to the lower atmospheric pressure the higher up we get. That is, at sea level the atmosphere has a pressure of 14.7 pounds per square inch; at 5,000 feet above sea level the pressure is approximately 12.13 pounds per square inch, and at 10,000 feet it is 10 pounds per square inch. From this it will be seen that the final pressure attained after the piston has driven the gas into compressed condition ready for firing is lower as the atmospheric pressure drops. This means that there is not so much power in the compressed charge of gas the higher up you get above sea level. "For example, suppose the compression ratio to be 4-1/2 to 1; in other words, suppose the air space above the piston to have 4-1/2 times the volume when the piston is at the bottom of its stroke that it has when the piston is at the top of the stroke. That is a common compression ratio for an average motor, and is chosen because it is considered to be the best for maximum horse-power and in order that the compression pressure will not be so high as to cause pre-ignition. Knowing the compression ratio, we can determine the final pressure immediately before ignition by substituting in the standard formula: P^{1} = P(V/V^{1})^{1.3} in which P is the atmospheric pressure; P^{1} is the final pressure, and V/V^{1} is the compression ratio, therefore P^{1} = 14.7 (4.5)^{1.3} = 104 pounds per square inch, absolute. "That is, 104 pounds per square inch is the most efficient final compression pressure to have for this engine at sea level, since it comes directly from the compression ratio. "Now supposing we consider that the altitude is 7,000 feet above sea level. At this height the atmospheric pressure is 11.25 pounds per square inch, approximately. In this case we can again substitute in the formula, using the new atmospheric pressure figure. The equation becomes: P^{1} = 11.25 (4.5)^{1.3}--79.4 pounds per square inch, absolute. "Therefore we now have a final compression pressure of only 79.4 pounds per square inch, which is considerably below the pressure we have just found to be the most efficient for the motor. The resulting power drop is evident. "It should be borne in mind that these final compression pressures are absolute pressures--that is, they include the atmospheric pressure. In the first case, to get the pressure above atmospheric you would subtract 14.7 and in the latter 11.25 would have to be deducted. In other words, where the sea level compression is 89.3 pounds per square inch above the atmosphere, the same motor will have only a compression pressure of 68.15 pounds per square inch above the atmosphere at 7,000 feet elevation. "From the above it is evident that in order to bring the final compression pressure up to the efficient figure we have determined, a different compression ratio would have to be used. That is, the final volume would have to be less, and as it is impossible to vary this to meet the conditions of altitude, the loss of power cannot be helped except by the replacing of the standard pistons with some that are longer above the wrist-pin so as to reduce the space above the pistons when on top center. Then if the ratio is thereby raised to some such figures as 5 to 1, the engine will again have its proper final pressure, but it will still not have as much power as it would have at sea level, since the horse-power varies directly with the atmospheric pressure, final compression being kept constant. That is, at 7,000 feet the horse-power of an engine that had 40 horse-power at sea level would be equal to 11.25 ------- = 30.6 horse-power. 14.7 "If the original compression ratio of 4.5 were retained, the drop in horse-power would be even greater than this. These computations and remarks will make it clear that the designer who contemplates building an airplane for high altitude use should see to it that it is of sufficient power to compensate for the drop that is inevitable when it is up in the air. This is often illustrated in stationary gas-engine installations. An engine that had a sea-level rating amply sufficient for the work required, might not be powerful enough when brought up several thousand feet." When one considers that airplanes attain heights of over 18,000 feet, it will be evident that an ample margin of engine power is necessary. THE DIESEL SYSTEM A system of fuel supply developed by the late Dr. Diesel, a German chemist and engineer, is attracting considerable attention at the present time on account of the ability of the Diesel engine to burn low-grade fuels, such as crude petroleum. In this system the engines are built so that very high compressions are used, and only pure air is taken into the cylinder on the induction stroke. This is compressed to a pressure of about 500 pounds per square inch, and sufficient heat is produced by this compression to explode a hydrocarbon mixture. As the air which is compressed to this high point cannot burn, the fuel is introduced into the cylinder combustion chamber under still higher compression than that of the compressed air, and as it is injected in a fine stream it is immediately vaporized because of the heat. Just as soon as the compressed air becomes thoroughly saturated with the liquid fuel, it will explode on account of the degree of heat present in the combustion chamber. Such motors have been used in marine and stationary applications, but are not practical for airplanes or motor cars because of lack of flexibility and great weight in proportion to power developed. The Diesel engine is the standard power plant used in submarine boats and motor ships, as its efficiency renders it particularly well adapted for large units. NOTES ON CARBURETOR INSTALLATION IN AIRPLANES A writer in "The Aeroplane," an English publication, discourses on some features of carburetor installation that may be of interest to the aviation student, so portions of the dissertation are reproduced herewith. "Users of airplanes fitted with ordinary type carburetors will do well to note carefully the way in which these are fitted, for several costly machines have been burnt lately through the sheer carelessness of their users. These particular machines were fitted with a high powered V-type engine, made by a firm which is famous as manufacturers of automobiles _de luxe_. In these engines there are four carburetors, mounted in the V between the cylinders. When the engine is fitted as a tractor, the float chambers are in front of the jet chambers. Consequently, when the tail of the machine is resting on the ground, the jets are lower than the level of the gasoline in the float chamber. "Quite naturally, the gasoline runs out of the jet, if it is left turned on when the machine is standing in its normal position, and trickles into the V at the top of the crank-case. Thence it runs down to the tail of the engine, where the magnetos are fitted, and saturates them. If left long enough, the gasoline manages to soak well into the fuselage before evaporating. And what does evaporate makes an inflammable gas in the forward cockpit. Then some one comes along and starts up the engine. The spark-gap of the magneto gives one flash, and the whole front of the machine proceeds to give a Fourth of July performance forthwith. Naturally, one safeguard is to turn the petrol off directly the machine lands. Another is never to turn it on till the engine is actually being started up. "One would be asking too much of the human boy--who is officially regarded as the only person fit to fly an aeroplane--if one depended upon his memory of such a detail to save his machine, though one might perhaps reasonably expect the older pilots to remember not to forget. Even so, other means of prevention are preferable, for fire is quite as likely to occur from just the same cause if the engine happens to be a trifle obstinate in starting, and so gives the carburetors several minutes in which to drip--in which operation they would probably be assisted by air-mechanics 'tickling' them. "One way out of the trouble is to fit drip tins under the jet chamber to catch the gasoline as it falls. This is all very well just to prevent fire while the machine is being started up, but it will not save it if it is left standing with the tail on the ground and the petrol turned on, for the drip tins will then fill up and run over. And if it catches then, the contents of the drip tins merely add fuel to the fire. _Reversing Carburetors_ "Yet another way is to turn the carburetors round, so that the float chambers are behind the jets, and so come below them when the tail is on the ground, thus cutting off the gasoline low down in the jets. There seems to be no particular mechanical difficulty about this, though I must confess that I did not note very carefully whether the reversal of the float chambers would make them foul any other fittings on the engine. It has been argued, however, that doing this would starve the engine of gasoline when climbing at a steep angle, as the gasoline would then be lowered in the jets and need more suction to get into the cylinders. This is rather a pretty point of amateur motor mechanics to discuss, for, obviously, when the same engine is used as a 'pusher' instead of a tractor, the jets are in front of the floats, and there seems to be no falling off in power. _Starvation of Mixture_ "Moreover, the higher a machine goes the lower is the atmospheric pressure, and, consequently, the less is the amount of air sucked in at each induction stroke. This means, of course, that with the gasoline supply the mixture at high altitudes is too rich, so that, in order to get precisely the right mixture when very high up, it is necessary to reduce the gasoline supply by screwing down the needle valve between the tank and the carburetor--at least, that has been the experience of various high-flying pilots. No doubt something might be done in the way of forced air feed to compensate for reduced atmospheric pressure, but it remains to be proved whether the extra weight of mechanism involved would pay for the extra power obtained. Variable compression might do something, also, to even things up, but here, also, weight of mechanism has to be considered. "In any case, at present, the higher one goes the more the power of the engine is reduced, for less air means a less volume of mixture per cylinder, and as the petrol feed has to be starved to suit the smaller amount of air available, this means further loss of power. I do not know whether anyone has evolved a carburetor which automatically starves the gasoline feed when high up, but it seems possible that when an airplane is sagging about 'up against the ceiling'--as a French pilot described the absolute limit of climb for his particular machine--it might be a good thing to have the jets in front of the float chamber, for then a certain amount of automatic starvation would take place. "When a machine is right up at its limiting height, and the pilot is doing his best to make it go higher still, it is probably flying with its tail as low as the pilot dares to let it go, and the lateral and longitudinal controls are on the verge of vanishing, so that if the carburetor jets are behind the float chambers there is bound to be an over-rich mixture in any case. There is even a possibility of a careless or ignorant pilot carrying on in this tail-down position till one set of cylinders cuts out altogether, in which case the carburetor feeding that set may flood over, just as if the machine were on the ground, and the whole thing may catch fire. Whereas, with the jets in front of the floats, though the mixture may starve a trifle, there is, at any rate, no danger of fire through climbing with the tail down. _A Diving Danger_ "On the other hand, in a 'pusher' with this type of engine, if the jets are in their normal position--which is in front of the floats--there is danger of fire in a dive. That is to say, if the pilot throttles right down, or switches off and relies on air pressure on his propeller to start the engine again, so that the gasoline is flooding over out of the jets instead of being sucked into the engine, there may be flooding over the magnetos if the dive is very steep and prolonged. In any case, a long dive will mean a certain amount of flooding, and, probably, a good deal of choking and spitting by the engine before it gets rid of the over-rich mixture and picks up steady firing again. Which may indicate to young pilots that it is not good to come down too low under such circumstances, trusting entirely to their engines to pick up at once and get going before they hit the ground. "On the whole, it seems that it might be better practice to set the carburetors thwartwise of engines, for then jets and floats would always be at approximately the same level, no matter what the longitudinal position of the machine, and it is never long enough in one position at a big lateral angle to raise any serious carburetor troubles. Car manufacturers who dive cheerfully into the troubled waters of aero-engine designs are a trifle apt to forget that their engines are put into positions on airplanes which would be positively indecent in a motor car. An angle of 1 in 10 is the exception on a car, but it is common on an airplane, and no one ever heard of a car going down a hill of 10 to 1--which is not quite a vertical dive. Therefore, there is every excuse for a well-designed and properly brought-up carburetor misbehaving itself in an aeroplane. "It seems, then, that it is up to the manufacturers to produce better carburetors--say, with the jet central with the float. But it also behooves the user to show ordinary common sense in handling the material at present available, and not to make a practice of burning up $25,000 worth or so of airplane just because he is too lazy to turn off his gasoline, or to have the tail of his machine lifted up while he is tinkering with his engines." NOTES ON CARBURETOR ADJUSTMENT The modern float feed carburetor is a delicate and nicely balanced appliance that requires a certain amount of attention and care in order to obtain the best results. The adjustments can only be made by one possessing an intelligent knowledge of carburetor construction and must never be made unless the reason for changing the old adjustment is understood. Before altering the adjustment of the leading forms of carburetors, a few hints regarding the quality to be obtained in the mixture should be given some consideration, as if these are properly understood this knowledge will prove of great assistance in adjusting the vaporizer to give a good working proportion of fuel and air. There is some question regarding the best mixture proportions and it is estimated that gas will be explosive in which the proportions of fuel vapor and air will vary from one part of the former to a wide range included between four and eighteen parts of the latter. A one to four mixture is much too rich, while the one in eighteen is much too lean to provide positive ignition. A rich mixture should be avoided because the excessive fuel used will deposit carbon and will soot the cylinder walls, combustion chamber interior, piston top and valves and also tend to overheat the motor. A rich mixture will also seriously interfere with flexible control of the engine, as it will choke up on low throttle and run well on open throttle when the full amount of gas is needed. A rich mixture may be quickly discovered by black smoke issuing from the muffler, the exhaust gas having a very pungent odor. If the mixture contains a surplus of air there will be popping sounds in the carburetor, which is commonly termed "blowing back." To adjust a carburetor is not a difficult matter when the purpose of the various control members is understood. The first thing to do in adjusting a carburetor is to start the motor and to retard the sparking lever so the motor will run slowly leaving the throttle about half open. In order to ascertain if the mixture is too rich cut down the gasoline flow gradually by screwing down the needle valve until the motor commences to run irregularly or misfire. Close the needle valves as far as possible without having the engine come to a stop, and after having found the minimum amount of fuel gradually unscrew the adjusting valve until you arrive at the point where the engine develops its highest speed. When this adjustment is secured the lock nut is screwed in place so the needle valve will keep the adjustment. The next point to look out for is regulation of the auxiliary air supply on those types of carburetors where an adjustable air valve is provided. This is done by advancing the spark lever and opening the throttle. The air valve is first opened or the spring tension reduced to a point where the engine misfires or pops back in the carburetor. When the point of maximum air supply the engine will run on is thus determined, the air valve spring may be tightened by screwing in on the regulating screw until the point is reached where an appreciable speeding up of the engine is noticed. If both fuel and air valves are set right, it will be possible to accelerate the engine speed uniformly without interfering with regularity of engine operation by moving the throttle lever or accelerator pedal from its closed to its wide open position, this being done with the spark lever advanced. All types of carburetors do not have the same means of adjustment; in fact, some adjust only with the gasoline regulating needle; others must have a complete change of spray nozzles; while in others the mixture proportions may be varied only by adjustment of the quantity of entering air. Changing the float level is effective in some carburetors, but this should never be done unless it is certain that the level is not correct. Full instructions for locating carburetion troubles will be given in proper sequence. It is a fact well known to experienced repairmen and motorists that atmospheric conditions have much to do with carburetor action. It is often observed that a motor seems to develop more power at night than during the day, a circumstance which is attributed to the presence of more moisture in the cooler night air. Likewise, taking a motor from sea level to an altitude of 10,000 feet involves using rarefied air in the engine cylinders and atmospheric pressures ranging from 14.7 pounds at sea level to 10.1 pounds per square inch at the high altitude. All carburetors will require some adjustment in the course of any material change from one level to another. Great changes of altitude also have a marked effect on the cooling system of an airplane. Water boils at 212 degrees F. only at sea level. At an altitude of 10,000 feet it will boil at a temperature nineteen degrees lower, or 193 degrees F. In high altitudes the reduced atmospheric pressure, for 5,000 feet or higher than sea level, results in not enough air reaching the mixture, so that either the auxiliary air opening has to be increased, or the gasoline in the mixture cut down. If the user is to be continually at high altitudes he should immediately purchase either a larger dome or a smaller strangling tube, mentioning the size carburetor that is at present in use and the type of motor that it is on, including details as to the bore and stroke. The smaller strangling tube makes an increased suction at the spray nozzle; the air will have to be readjusted to meet it and you can use more auxiliary air, which is necessary. The effect on the motor without a smaller strangling tube is a perceptible sluggishness and failure to speed up to its normal crank-shaft revolutions, as well as failure to give power. It means that about one-third of the regular speed is cut out. The reduced atmospheric pressure reduces the power of the explosion, in that there is not the same quantity of oxygen in the combustion chamber as at sea level; to increase the amount taken in, you must also increase the gasoline speed, which is done by an increased suction through the smaller strangling aperture. Some forms of carburetors are affected more than others by changes of altitude, which explains why the Zenith is so widely employed for airplane engine use. The compensating nozzle construction is not influenced as much by changes of altitude as the simpler nozzle types are. CHAPTER VI Early Ignition Systems--Electrical Ignition Best--Fundamentals of Magnetism Outlined--Forms of Magneto--Zones of Magnetic Influence--How Magnets are Made--Electricity and Magnetism Related--Basic Principles of Magneto Action--Essential Parts of Magneto and Functions--Transformer Coil Systems--True High Tension Type--The Berling Magneto--Timing and Care--The Dixie Magneto--Spark Plug Design and Application--Two-Spark Ignition-- Special Airplane Plug. EARLY IGNITION SYSTEMS One of the most important auxiliary groups of the gasoline engine comprising the airplane power plant and one absolutely necessary to insure engine action is the ignition system or the method employed of kindling the compressed gas in the cylinder to produce an explosion and useful power. The ignition system has been fully as well developed as other parts of the engine, and at the present time practically all ignition systems follow principles which have become standard through wide acceptance. During the early stages of development of the gasoline engine various methods of exploding the charge of combustible gas in the cylinder were employed. On some of the earliest engines a flame burned close to the cylinder head, and at the proper time for ignition a slide or valve moved to provide an opening which permitted the flame to ignite the gas back of the piston. This system was practical only on the primitive form of gas engines in which the charge was not compressed before ignition. Later, when it was found desirable to compress the gas a certain degree before exploding it, an incandescent platinum tube in the combustion chamber, which was kept in a heated condition by a flame burning in it, exploded the gas. The naked flame was not suitable in this application because when the slide was opened to provide communication between the flame and the gas the compressed charge escaped from the cylinder with enough pressure to blow out the flame at times and thus cause irregular ignition. When the flame was housed in a platinum tube it was protected from the direct action of the gas, and as long as the tube was maintained at the proper point of incandescence regular ignition was obtained. Some engineers utilized the property of gases firing themselves if compressed to a sufficient degree, while others depended upon the heat stored in the cylinder-head to fire the highly compressed gas. None of these methods were practical in their application to motor car engines because they did not permit flexible engine action which is so desirable. At the present time, electrical ignition systems in which the compressed gas is exploded by the heating value of the minute electric arc or spark in the cylinder are standard, and the general practice seems to be toward the use of mechanical producers of electricity rather than chemical batteries. ELECTRICAL IGNITION BEST Two general forms of electrical ignition systems may be used, the most popular being that in which a current of electricity under high tension is made to leap a gap or air space between the points of the sparking plug screwed into the cylinder. The other form, which has been almost entirely abandoned in automobile and which was never used with airplane engine practice, but which is still used to some extent on marine engines, is called the low-tension system because current of low voltage is used and the spark is produced by moving electrodes in the combustion chamber. The essential elements of any electrical ignition system, either high or low tension, are: First, a simple and practical method of current production; second, suitable timing apparatus to cause the spark to occur at the right point in the cycle of engine action; third, suitable wiring and other apparatus to convey the current produced by the generator to the sparking member in the cylinder. The various appliances necessary to secure prompt ignition of the compressed gases should be described in some detail because of the importance of the ignition system. It is patent that the scope of a work of this character does not permit one to go fully into the theory and principles of operation of all appliances which may be used in connection with gasoline motor ignition, but at the same time it is important that the elementary principles be considered to some extent in order that the reader should have a proper understanding of the very essential ignition apparatus. The first point considered will be the common methods of generating the electricity, then the appliances to utilize it and produce the required spark in the cylinder. Inasmuch as magneto ignition is universally used in connection with airplane engine ignition it will not be necessary to consider battery ignition systems. FUNDAMENTALS OF MAGNETISM OUTLINED To properly understand the phenomena and forces involved in the generation of electrical energy by mechanical means it is necessary to become familiar with some of the elementary principles of magnetism and its relation to electricity. The following matter can be read with profit by those who are not familiar with the subject. Most persons know that magnetism exists in certain substances, but many are not able to grasp the terms used in describing the operation of various electrical devices because of not possessing a knowledge of the basic facts upon which the action of such apparatus is based. Magnetism is a property possessed by certain substances and is manifested by the ability to attract and repel other materials susceptible to its effects. When this phenomenon is manifested by a conductor or wire through which a current of electricity is flowing it is termed "electro-magnetism." Magnetism and electricity are closely related, each being capable of producing the other. Practically all of the phenomena manifested by materials which possess magnetic qualities naturally can be easily reproduced by passing a current of electricity through a body which, when not under electrical influence, is not a magnetic substance. Only certain substances show magnetic properties, these being iron, nickel, cobalt and their alloys. The earliest known substance possessing magnetic properties was a stone first found in Asia Minor. It was called the lodestone or leading stone, because of its tendency, if arranged so it could be moved freely, of pointing one particular portion toward the north. The compass of the ancient Chinese mariners was a piece of this material, now known to be iron ore, suspended by a light thread or floated on a cork in some liquid so one end would point toward the north magnetic pole of the earth. The reason that this stone was magnetic was hard to define for a time, until it was learned that the earth was one huge magnet and that the iron ore, being particularly susceptible, absorbed and retained some of this magnetism. Most of us are familiar with some of the properties of the magnet because of the extensive sale and use of small horseshoe magnets as toys. As they only cost a few pennies every one has owned one at some time or other and has experimented with various materials to see if they would be attracted. Small pieces of iron or steel were quickly attracted to the magnet and adhered to the pole pieces when brought within the zone of magnetic influence. It was soon learned that brass, copper, tin or zinc were not affected by the magnet. A simple experiment that serves to illustrate magnetic attraction of several substances is shown at A, Fig. 57. In this, several balls are hung from a standard or support, one of these being of iron, another of steel. When a magnet is brought near either of these they will be attracted toward it, while the others will remain indifferent to the magnetic force. Experimenters soon learned that of the common metals only iron or steel were magnetic. [Illustration: Fig. 57.--Some Simple Experiments to Demonstrate Various Magnetic Phenomena and Clearly Outline Effects of Magnetism and Various Forms of Magnets.] If the ordinary bar or horseshoe magnet be carefully examined, one end will be found to be marked N. This indicates the north pole, while the other end is not usually marked and is the south pole. If the north pole of one magnet is brought near the south pole of another, a strong attraction will exist between them, this depending upon the size of the magnets used and the air gap separating the poles. If the south pole of one magnet is brought close to the end of the same polarity of the other there will be a pronounced repulsion of like force. These facts are easily proved by the simple experiment outlined at B, Fig. 57. A magnet will only attract or influence a substance having similar qualities. The like poles of magnets will repel each other because of the obvious impossibility of uniting two influences or forces of practically equal strength but flowing in opposite directions. The unlike poles of magnets attract each other because the force is flowing in the same direction. The flow of magnetism is through the magnet from south to north and the circuit is completed by the flow of magnetic influence through the air gap or metal armature bridging it from the north to the south pole. FORMS OF MAGNETS AND ZONE OF MAGNETIC INFLUENCE DEFINED Magnets are commonly made in two forms, either in the shape of a bar or horseshoe. These two forms are made in two types, simple or compound. The latter are composed of a number of magnets of the same form united so the ends of like polarity are laced together, and such a construction will be more efficient and have more strength than a simple magnet of the same weight. The two common forms of simple and compound magnets are shown at C, Fig. 57. The zone in which a magnetic influence occurs is called the magnetic field, and this force can be graphically shown by means of imaginary lines, which are termed "lines of force." As will be seen from the diagram at D, Fig. 57, the lines show the direction of action of the magnetic force and also show its strength, as they are closer together and more numerous when the intensity of the magnetic field is at its maximum. A simple method of demonstrating the presence of the force is to lay a piece of thin paper over the pole pieces of either a bar or horseshoe magnet and sprinkle fine iron filings on it. The particles of metal arrange themselves in very much the manner shown in the illustrations and prove that the magnetic field actually exists. The form of magnet used will materially affect the size and area of the magnetic field. It will be noted that the field will be concentrated to a greater extent with the horseshoe form because of the proximity of the poles. It should be understood that these lines have no actual existence, but are imaginary and assumed to exist only to show the way the magnetic field is distributed. The magnetic influence is always greater at the poles than at the center, and that is why a horseshoe or U-form magnet is used in practically all magnetos or dynamos. This greater attraction at the poles can be clearly demonstrated by sprinkling iron filings on bar and U magnets, as outlined at E, Fig. 57. A large mass gathers at the pole pieces, gradually tapering down toward the point where the attraction is least. From the diagrams it will be seen that the flow of magnetism is from one pole to the other by means of curved paths between them. This circuit is completed by the magnetism flowing from one pole to the other through the magnet, and as this flow is continued as long as the body remains magnetic it constitutes a magnetic circuit. If this flow were temporarily interrupted by means of a conductor of electricity moving through the field there would be a current of electricity induced in the conductor every time it cut the lines of force. There are three kinds of magnetic circuits. A non-magnetic circuit is one in which the magnetic influence completes its circuit through some substance not susceptible to the force. A closed magnetic circuit is one in which the influence completes its circuit through some magnetic material which bridges the gap between the poles. A compound circuit is that in which the magnetic influence passes through magnetic substances and non-magnetic substances in order to complete its circuit. HOW IRON AND STEEL BARS ARE MADE MAGNETIC Magnetism may be produced in two ways, by contact or induction. If a piece of steel is rubbed on a magnet it will be found a magnet when removed, having a north and south pole and all of the properties found in the energizing magnet. This is magnetizing by contact. A piece of steel will retain the magnetism imparted to it for a considerable length of time, and the influence that remains is known as residual magnetism. This property may be increased by alloying the steel with tungsten and hardening it before it is magnetized. Any material that will retain its magnetic influence after removal from the source of magnetism is known as a permanent magnet. If a piece of iron or steel is brought into the magnetic field of a powerful magnet it becomes a magnet without actual contact with the energizer. This is magnetizing by magnetic induction. If a powerful electric current flows through an insulated conductor wound around a piece of iron or steel it will make a magnet of it. This is magnetizing by electro-magnetic induction. A magnet made in this manner is termed an electro-magnet and usually the metal is of such a nature that it will not retain its magnetism when the current ceases to flow around it. Steel is used in all cases where permanent magnets are required, while soft iron is employed in all cases where an intermittent magnetic action is desired. Magneto field magnets are always made of tungsten steel alloy, so treated that it will retain its magnetism for lengthy periods. ELECTRICITY AND MAGNETISM CLOSELY RELATED There are many points in which magnetism and electricity are alike. For instance, air is a medium that offers considerable resistance to the passage of both magnetic influence and electric energy, although it offers more resistance to the passage of the latter. Minerals like iron or steel are very easily influenced by magnetism and easily penetrated by it. When one of these is present in the magnetic circuit the magnetism will flow through the metal. Any metal is a good conductor for the passage of the electric current, but few metals are good conductors of magnetic energy. A body of the proper metal will become a magnet due to induction if placed in the magnetic field, having a south pole where the lines of force enter it and a north pole where they pass out. We have seen that a magnet is constantly surrounded by a magnetic field and that an electrical conductor when carrying a current is also surrounded by a field of magnetic influence. Now if the conductor carrying a current of electricity will induce magnetism in a bar of iron or steel, by a reversal of this process, a magnetized iron or steel bar will produce a current of electricity in a conductor. It is upon this principle that the modern dynamo or magneto is constructed. If an electro-motive force is induced in a conductor by moving it across a field of magnetic influence, or by passing a magnetic field near a conductor, electricity is said to be generated by magneto-electric induction. All mechanical generators of the electric current using permanent steel magnets to produce a field of magnetic influence are of this type. BASIC PRINCIPLES OF MAGNETO OUTLINED The accompanying diagram, Fig. 58, will show these principles very clearly. As stated on an earlier page, if the lines of force in the magnetic field are cut by a suitable conductor an electrical impulse will be produced in that conductor. In this simple machine the lines of force exist between the poles of a horseshoe magnet. The conductor, which in this case is a loop of copper wire, is mounted upon a spindle in order that it may be rotated in the magnetic field to cut the lines of magnetic influence present between the pole pieces. Both of the ends of this loop are connected, one with the insulated drum shown upon the shaft, the other to the shaft. Two metal brushes are employed to collect the current and cause it to flow through the external circuit. It can be seen that when the shaft is turned in the direction of the arrow the loop will cut through the lines of magnetic influence and a current will be generated therein. [Illustration: Fig. 58.--Elementary Form of Magneto Showing Principal Parts Simplified to Make Method of Current Generation Clear.] The pressure of the current and the amount produced vary in accordance to the rapidity with which the lines of magnetic influence are cut. The armature of a practical magneto, therefore, differs materially from that shown in the diagram. A large number of loops of wire would be mounted upon this shaft in order that the lines of magnetic influence would be cut a greater number of times in a given period and a core of iron used as a backing for the wire. This would give a more rapid alternating current and a higher electro-motive force than would be the case with a smaller number of loops of wire. [Illustration: Fig. 59.--Showing How Strength of Magnetic Influence and of the Currents Induced in the Windings of Armature Vary with the Rapidity of Changes of Flow.] The illustrations at Fig. 59 show a conventional double winding armature and field magnetic of a practical magneto in part section and will serve to more fully emphasize the points previously made. If the armature or spindle were removed from between the pole pieces there would exist a field of magnetic influence as shown at Fig. 57, but the introduction of this component provides a conductor (the iron core) for the magnetic energy, regardless of its position, though the facility with which the influence will be transmitted depends entirely upon the position of the core. As shown at A, the magnetic flow is through the main body in a straight line, while at B, which position the armature has attained after one-eighth revolution, or 45 degrees travel in the direction of the arrow, the magnetism must pass through in the manner indicated. At C, which position is attained every half revolution, the magnetic energy abandons the longer path through the body of the core for the shorter passage offered by the side pieces, and the field thrown out by the cross bar disappears. On further rotation of the armature, as at D, the body of the core again becomes energized as the magnetic influence resumes its flow through it. These changes in the strength of the magnetic field when distorted by the armature core, as well as the intensity of the energy existing in the field, affect the windings, and the electrical energy induced therein corresponds in strength to the rapidity with which these changes in magnetic flow occur. The most pronounced changes in the strength of the field will occur as the armature passes from position B to D, because the magnetic field existing around the core will be destroyed and again re-established. During the most of the armature rotation the changes in strength will be slight and the currents induced in the wire correspondingly small; but at the instant the core becomes remagnetized, as the armature leaves position C, the current produced will be at its maximum, and it is necessary to so time the rotation of the armature that at this instant one of the cylinders is in condition to be fired. It is imperative that the armature be driven in such relation to the crank-shaft that each production of maximum current coincides with the ignition point, this condition existing twice during each revolution of the armature, or at every 180 degrees travel. Each position shown corresponds to 45 degrees travel of the armature, or one-eighth of a turn, and it takes just three-eighths revolution to change the position from A to that shown at D. ESSENTIAL PARTS OF A MAGNETO AND THEIR FUNCTIONS The magnets which produce the influence that in turn induces the electrical energy in the winding or loops of wire on the armature, and which may have any even number of opposed poles, are called field magnets. The loops of wire which are mounted upon a suitable drum and rotate in the field of magnetic influence in order to cut the lines of force is called an armature winding, while the core is the metal portion. The entire assembly is called the armature. The exposed ends of the magnets are called pole pieces and the arrangement used to collect the current is either a commutator or a collector. The stationary pieces which bear against the collector or commutator and act as terminals for the outside circuit are called brushes. These brushes are often of copper, or some of its alloys, because copper has a greater electrical conductivity than any other metal. These brushes are nearly always of carbon, which is sometimes electroplated with copper to increase its electrical conductivity, though cylinders of copper wire gauze impregnated with graphite are utilized at times. Carbon is used because it is not so liable to cut the metal of the commutator as might be the case if the contact was of the metal to metal type. The reason for this is that carbon has the peculiar property in that it materially assists in the lubrication of the commutator, and being of soft, unctuous composition, will wear and conform to any irregularities on the surface of the metal collector rings. The magneto in common use consists of a number of horseshoe magnets which are compound in form and attached to suitable cast-iron pole pieces used to collect and concentrate the magnetic influence of the various magnets. Between these pole pieces an armature rotates. This is usually shaped like a shuttle, around which are wound coils of insulated wire. These are composed of a large number of turns and the current produced depends in great measure upon the size of the wire and the number of turns per coil. An armature winding of large wire will deliver a current of great amperage, but of small voltage. An armature wound with very fine wire will deliver a current of high voltage but of low amperage. In the ordinary form of magneto, such as used for ignition, the current is alternating in character and the break in the circuit should be timed to occur when the armature is at the point of its greatest potential or pressure. Where such a generator is designed for direct current production the ends of the winding are attached to the segments of a commutator, but where the instrument is designed to deliver an alternating current one end of the winding is fastened to an insulator ring on one end of the armature shaft and the other end is grounded on the frame of the machine. The quantity of the current depends upon the strength of the magnetic field and the number of lines of magnetic influence acting through the armature. The electro-motive force varies as to the length of the armature winding and the number of revolutions at which the armature is rotated. THE TRANSFORMER SYSTEM USES LOW VOLTAGE MAGNETO The magneto in the various systems which employ a transformer coil is very similar to a low-tension generator in general construction, and the current delivered at the terminals seldom exceeds 100 volts. As it requires many times that potential or pressure to leap the gap which exists between the points of the conventional spark plug, a separate coil is placed in circuit to intensify the current to one of greater capacity. The essential parts of such a system and their relation to each other are shown in diagrammatic form at Fig. 60 and as a complete system at Fig. 61. As is true of other systems the magnetic influence is produced by permanent steel magnets clamped to the cast-iron pole pieces between which the armature rotates. At the point of greatest potential in the armature winding the current is broken by the contact breaker, which is actuated by a cam, and a current of higher value is induced in the secondary winding of the transformer coil when the low voltage current is passed through the primary winding. [Illustration: Fig. 60.--Diagrams Explaining Action of Low Tension Transformer Coil and True High Tension Magneto Ignition Systems.] [Illustration: Fig. 60A.--Side Sectional View of Bosch High-Tension Magneto Shows Disposition of Parts. End Elevation Depicts Arrangement of Interruptor and Distributor Mechanism.] It will be noted that the points of the contact breaker are together except for the brief instant when separated by the action of the point of the cam upon the lever. It is obvious that the armature winding is short-circuited upon itself except when the contact points are separated. While the armature winding is thus short-circuited there will be practically no generation of current. When the points are separated there is a sudden flow of current through the primary winding of the transformer coil, inducing a secondary current in the other winding, which can be varied in strength by certain considerations in the preliminary design of the apparatus. This current of higher potential or voltage is conducted directly to the plug if the device is fitted to a single-cylinder engine, or to the distributor arm if fitted to a multiple-cylinder motor. The distributor consists of an insulator in which is placed a number of segments, one for each cylinder to be fired, and so spaced that the number of degrees between them correspond to the ignition points of the motor. A two-cylinder motor would have two segments, a three-cylinder, three segments, and so on within the capacity of the instrument. In the illustration a four-cylinder distributor is fitted, and the distributing arm is in contact with the segment corresponding to the cylinder about to be fired. [Illustration: Fig. 61.--Berling Two-Spark Dual Ignition System.] TRUE HIGH-TENSION MAGNETOS ARE SELF-CONTAINED [Illustration: Fig. 62.--Berling Double-Spark Independent System.] The true high-tension magneto differs from the preceding inasmuch as the current of high voltage is produced in the armature winding direct, without the use of the separate coil. Instead of but one coil, the armature carries two, one of comparatively coarse wire, the other of many turns of finer wire. The arrangement of these windings can be readily ascertained by reference to the diagram B, Fig. 60, which shows the principle of operation very clearly. The simplicity of the ignition system is evident by inspection of Fig. 62. One end of the primary winding (coarse wire) is coupled or grounded to the armature core, and the other passes to the insulated part of the interrupter. While in some forms the interrupter or contact breaker mechanism does not revolve, the desired motion being imparted to the contact lever to separate the points of a revolving cam, in this the cam or tripping mechanism is stationary and the contact breaker revolves. This arrangement makes it possible to conduct the current from the revolving primary coil to the interrupter by a direct connection, eliminating the use of brushes, which would otherwise be necessary. In other forms of this appliance where the winding is stationary, the interrupter may be operated by a revolving cam, though, if desired, the used of a brush at this point will permit this construction with a revolving winding. During the revolution of the armature the grounded lever makes and breaks contact with the insulated point, short-circuiting the primary winding upon itself until the armature reaches the proper position of maximum intensity of current production, at which time the circuit is broken, as in the former instance. One end of the secondary winding (fine wire) is grounded on the live end of the primary, the other end being attached to the revolving arm of the distributor mechanism. So long as a closed circuit is maintained feeble currents will pass through the primary winding, and so long as the contact points are together this condition will exist. When the current reaches its maximum value, because of the armature being in the best position, the cam operates the interrupter and the points are separated, breaking the short circuit which has existed in the primary winding. The secondary circuit has been open while the distributor arm has moved from one contact to another and there has been no flow of energy through this winding. While the electrical pressure will rise in this, even if the distributor arm contacted with one of the segments, there would be no spark at the plug until the contact points separated, because the current in the secondary winding would not be of sufficient strength. When the interrupter operates, however, the maximum primary current will be diverted from its short circuit and can flow to the ground only through the secondary winding and spark-plug circuit. The high pressure now existing in the secondary winding will be greatly increased by the sudden flow of primary current, and energy of high enough potential to successfully bridge the gap at the plug is thereby produced in the winding. THE BERLING MAGNETO [Illustration: Fig. 63.--Type DD Berling High Tension Magneto.] The Berling magneto is a true high tension type delivering two impulses per revolution, but it is made in a variety of forms, both single and double spark. Its principle of action does not differ in essentials from the high tension type previously described. This magneto is used on Curtiss aviation engines and will deliver sparks in a positive manner sufficient to insure ignition of engines up to 200 horse-power and at rotative speeds of the magneto armature up to 4,000 r. p. m. which is sufficient to take care of an eight-cylinder V engine running up to 2,000 r. p. m. The magneto is driven at crank-shaft speed on four-cylinder engines, at 1-1/2 times crank-shaft speed on six-cylinder engines and at twice crank-shaft speed on eight-cylinder V types. The types "D" and "DD" BERLING Magnetos are interchangeable with corresponding magnetos of other standard makes. The dimensions of the four-, six- and eight-cylinder types "D" and "DD" are all the same. The ideal method of driving the magneto is by means of flexible direct connecting coupling to a shaft intended for the purpose of driving the magneto. As the magneto must be driven at a high speed, a coupling of some flexibility is preferable. The employment of such a coupling will facilitate the mounting of the magneto, because a small inaccuracy in the lining up of the magneto with the driving shaft will be taken care of by the flexible coupling, whereas with a perfectly rigid coupling the line-up of the magneto must be absolutely accurate. Another advantage of the flexible coupling is that the vibration of the motor will not be as fully transmitted to the armature shaft on the magneto as in case a rigid coupling is used. This means prolonged life for the magneto. The next best method of driving the magneto is by means of a gear keyed to the armature shaft. When this method of driving is employed, great care must be exercised in providing sufficient clearance between the gear on the magneto and the driving gear. If there should be a tight spot between these two gears it will react disadvantageously on the magneto. The third available method is to drive the magneto by means of a chain. This is the least desirable of the three methods and should be resorted to only in case of absolute necessity. It is difficult to provide sufficient clearance when using a chain without rendering the timing less accurate and positive. [Illustration: Fig. 64.--Wiring Diagrams of Berling Magneto Ignition Systems.] Fig. 64, A shows diagrammatically the circuit of the "D" type two-spark independent magneto and the switch used with it. In position OFF the primary winding of the magneto is short-circuited and in this position the switch serves as an ordinary cut-out or grounding switch. In position "1" the switch connects the magneto in such a way that it operates as an ordinary single-spark magneto. In this position one end of the secondary winding is grounded to the body of the motor. This is the starting position. In this position of the switch the entire voltage generated in the magneto is concentrated at one spark-plug instead of being divided in half. With the motor turning over very slowly, as is the case in starting, the full voltage generated by the magneto will not in all cases be sufficient to bridge simultaneously two spark gaps, but is amply sufficient to bridge one. Also, this position of the switch tends to retard the ignition and should be used in starting to prevent back-firing. With the switch in position "2" the magneto applies ignition to both plugs in each cylinder simultaneously. This is the normal running position. Fig. 64, B shows diagrammatically the circuit of the type "DD" BERLING high-tension two-spark dual magneto. This type is recommended for certain types of heavy-duty airplane motors, which it is impossible to turn over fast enough to give the magneto sufficient speed to generate even a single spark of volume great enough to ignite the gas in the cylinder. The dual feature consists of the addition to the magneto of a battery interrupter. The equipment consists of the magneto, coil and special high-tension switch. The coil is intended to operate on six volts. Either a storage battery or dry cells may be used. With the switch in the OFF position, the magneto is grounded, and the battery circuit is open. With the switch in the second or battery position marked "BAT," one end of the secondary winding of the magneto is grounded, and the magneto operates as a single-spark magneto delivering high-tension current to the inside distributor, and the battery circuit being closed the high-tension current from the coil is delivered to the outside distributor. In this position the battery current is supplied to one set of spark plugs, no matter how slowly the motor is turned over, but as soon as the motor starts, the magneto supplies current as a single-spark magneto to the other set of the spark-plugs. After the engine is running, the switch should be thrown to the position marked "MAG." The battery and coil are then disconnected, and the magneto furnishes ignition to both plugs in each cylinder. This is the normal running position. Either a non-vibrating coil type "N-1" is furnished or a combined vibrating and non-vibrating coil type "VN-1." SETTING BERLING MAGNETO The magneto may be set according to one of two different methods, the selection of which is, to some extent, governed by the characteristics of the engine, but largely due to the personal preference on the part of the user. In the first method described below, the most advantageous position of the piston for fully advanced ignition is determined in relation to the extreme advanced position of the magneto. In this case, the fully retarded ignition will not be a matter of selection, but the timing range of the magneto is wide enough to bring the fully retarded ignition after top-center position of the piston. The second method for the setting of the magneto fixes the fully retarded position of the magneto in relation to that position of the piston where fully retarded ignition is desired. In this case, the extreme advance position of the magneto will not always correspond with the best position of the piston for fully advanced ignition, and the amount of advance the magneto should have to meet ideal requirements in this respect must be determined by experiment. _First Method:_ 1. Designate one cylinder as cylinder No. 1. 2. Turn the crank-shaft until the piston in cylinder No. 1 is in the position where the fully advanced spark is desired to occur. 3. Remove the cover from the distributor block and turn the armature shaft in the direction of rotation of the magneto until the distributor finger-brush comes into such a position that this brush makes contact with the segment which is connected to the cable terminal marked "1." This is either one of the two bottom segments, depending upon the direction of rotation. 4. Place the cam housing in extreme advance, i.e., turn the cam housing until it stops, in the direction opposite to the direction of rotation of the armature. With the cam housing in this position, open the cover. 5. With the armature in the approximate position as described in "3," turn the armature slightly in either direction to such a point that the platinum points of the magneto interrupter will just begin to open at the end of the cam, adjacent to the fibre lever on the interrupter. 6. With this exact position of the armature, fix the magneto to the driving member of the engine. _Second Method:_ 1. Designate one cylinder as cylinder No. 1. 2. Turn the crank-shaft until the piston in cylinder No. 1 is in the position at which the fully retarded spark is desired to occur. 3. Same as No. 3 under First Method. 4. Place the cam housing in extreme retard, i.e., turn the cam housing until it stops, in the same direction as the direction of rotation of the armature. With the cam housing in this position, open the cover. 5. Same as No. 5 under First Method. 6. Same as No. 6 under First Method. WIRING THE MAGNETO The wiring of the magneto is clearly shown by wiring diagram. First determine the sequence of firing for the cylinders and then connect the cables to the spark plug in the cylinders in proper sequence, beginning with cylinder No. 1 marked on the distributor block. The switch used with the independent type must be mounted in such a manner that there will be a metallic connection between the frame of the magneto and the metal portion of the switch. It is advisable to use a separate battery, either storage or dry cells, as a source of current for the dual equipment. Connecting to the same battery that is used with the generator and other electrical equipment may cause trouble, as a "ground" in this battery causes the coil to overheat. CARE AND MAINTENANCE _Lubrication:_ Use only the very best of oil for the oil cups. Put five drops of oil in the oil cup at the driving end of the magneto for every fifty hours of actual running. Put five drops of oil in the oil cup at the interrupter end of the magneto, located at one side of the cam housing, for every hundred hours of actual running. Lubricate the embossed cams in the cam housing with a thin film of vaseline every fifty hours of actual running. Wipe off all superfluous vaseline. Never use oil in the interrupter. Do not lubricate any other part of the interrupter. _Adjusting the Interrupter:_ With the fibre lever in the center of one of the embossed cams, as at Fig. 65, the opening between the platinum contacts should be not less than .016" and not more than .020". The gauge riveted to the adjusting wrench should barely be able to pass between the contacts when fully open. The platinum contacts must be smoothed off with a very fine file. When in closed position, the platinum contacts should make contact with each other over their entire surfaces. When inspecting the interrupter, make sure that the ground brush in the back of the interrupter base is making good contact with the surface on which it rubs. _Cleaning the Distributor:_ The distributor block cover should be removed for inspection every twenty-five hours of actual running and the carbon deposit from the distributor finger-brush wiped off the distributor block by rubbing with a rag or piece of waste dipped in gasoline or kerosene. The high-tension terminal brush on the side of the magneto should also be carefully inspected for proper tension. LOCATING TROUBLE Trouble in the ignition system is indicated by the motor "missing," stopping entirely, or by inability to start. It is safe to assume that the trouble is not in the magneto, and the carburetor, gasoline supply and spark-plugs should first be investigated. [Illustration: Fig. 65.--The Berling Magneto Breaker Box Showing Contact Points Separated and Interruptor Lever on Cam.] If the magneto is suspected, the first thing to do is to determine if it will deliver a spark. To determine this, disconnect one of the high-tension leads from the spark-plug in one of the cylinders and place it so that there is approximately 1/16" between the terminal and the cylinder frame. Open the pet cocks on the other cylinders to prevent the engine from firing and turn over the engine until the piston is approaching the end of the compression stroke in the cylinder from which the cable has been removed. Set the magneto in the advance position and rapidly rock the engine over the top-center position, observing closely if a spark occurs between the end of the high-tension cable and the frame. If the magneto is of the dual type, the trouble may be either in the magneto or in the battery or coil system, therefore disconnect the battery and place the switch in the position marked "MAG." The magneto will then operate as an independent magneto and should spark in the proper manner. After this the battery system should be investigated. To test the operation of the battery and coil, examine all connections, making sure that they are clean and tight, and then with the switch, in the "BAT," rock the piston slowly back and forth. If a type "VN-1" coil is used, a shower of sparks should jump between the high-tension cable terminal and the cylinder frame when the piston is in the correct position for firing. If no spark occurs, remove the cover from the coil and see that the vibrating tongue is free. If a type "N-1" coil is used, a single spark will occur. The battery should furnish six volts when connected to the coil, and this should also be verified. If the coil still refuses to give a spark and all connections are correct, the coil should be replaced and the defective coil returned to the manufacturer. If both magneto and coil give a spark when tested as just described, the spark-plugs should be investigated. To do this, disconnect the cables and remove the spark-plugs. Then reconnect the cables to the plugs and place them so that the frame portions of the plugs are in metallic connection with the frame of the motor. Then turn over the motor, thus revolving the magneto armature, and see if a spark is produced at the spark gaps of the plugs. The most common defects in spark-plugs are breaking down of the insulation, fouling due to carbon, or too large or small a spark gap. To clean the plugs a stiff brush and gasoline should be used. The spark gap should be about 1/32" and never less than 1/64". Too small a gap may have been caused by beads of metal forming due to the heat of the spark. Too long a gap may have been caused by the points burning off. If the magneto and spark plugs are in good condition and the engine does not run satisfactorily, the setting should be verified according to instructions previously given, and, if necessary, readjusted. [Illustration: Fig. 66.--The Dixie Model 60 for Six-Cylinder Airplane Engine Ignition.] Be careful to observe that both the type "VN-1" and type "N-1" coils are so arranged that the spark occurs on the opening of the contacts of the timer. As this is just the reverse of the usual operation, it should be carefully noted when any change in the setting of the timer is made. The timer on the dual type magneto is adjusted so that the battery spark occurs about 5° later than the magneto spark. This provides an automatic advance as soon as the switch is thrown to the magneto position "MAG." This relative timing can be easily adjusted by removing the interrupter and shifting the cam in the direction desired. THE DIXIE MAGNETO [Illustration: Fig. 67.--Installation Dimensions of Dixie Model 60 Magneto.] The Dixie magneto, shown at Fig. 66, operates on a different principle than the rotary armature type. It is used on the Hall-Scott and other aviation engines. In this magneto the rotating member consists of two pieces of magnetic material separated by a non-magnetic center piece. This member constitutes true rotating poles for the magnet and rotates in a field structure, composed of two laminated field pieces, riveted between two non-magnetic rings. The bearings for the rotating poles are mounted in steel plates, which lie against the poles of the magnets. When the magnet poles rotate, the magnetic lines of force from each magnet pole are carried directly to the field pieces and through the windings, without reversal through the mass of the rotating member and with only a single air gap. There are no losses by flux reversal in the rotating part, such as take place in other machines, and this is said to account for the high efficiency of the instrument. [Illustration: Fig. 68.--The Rotating Elements of the Dixie Magneto.] And this "Mason Principle" involved in the operation of the Dixie is simplified by a glance at the field structure, consisting of the non-magnetic rings, assembled to which are the field pieces between which the rotating poles revolve (see Fig. 68). Rotating between the limbs of the magnets, these two pieces of magnetic material form true extensions to the poles of the magnets, and are, in consequence, _always_ of the _same_ polarity. It will be seen there is no reversal of the magnetism through them, and consequently no eddy current or hysteresis losses which are present in the usual rotor or inductor types. The simplicity features of construction stand out prominently here, in that there are no revolving windings, a detail entirely differing from the orthodox high-tension instrument. This simplicity becomes instantly apparent when it is found that the circuit breaker, instead of revolving as it does in other types, is stationary and that the whole breaker mechanism is exposed by simply turning the cover spring aside and removing cover. This makes inspection and adjustment particularly simple, and the fact that no special tool is necessary for adjustment of the platinum points--an ordinary small screw-driver is the whole "kit of tools" needed in the work of disassembling or assembling--is a feature of some value. [Illustration: Fig. 69.--Suggestions for Adjusting and Dismantling Dixie Magneto. A--Screw Driver Adjusts Contact Points. B--Distributor Block Removed. C--Taking off Magnets. D--Showing How Easily Condenser and High Tension Windings are Removed.] With dust- and water-protecting casing removed, and one of the magnets withdrawn, as in Fig. 69, the winding can be seen with its core resting on the field pole pieces and the primary lead attached to its side. An important feature of the high-tension winding is that the heads are of insulating material, and there is not the tendency for the high-tension current to jump to the side as in the ordinary armature type magneto. The high-tension current is carried to the distributor by means of an insulated block with a spindle, at one end of which is a spring brush bearing directly on the winding, thus shortening the path of the high-tension current and eliminating the use of rubber spools and insulating parts. The moving parts of the magneto need never be disturbed if the high-tension winding is to be removed. This winding constitutes all of the magneto windings, no external spark coil being necessary. The condenser is placed directly above the winding and is easily removable by taking out two screws, instead of being placed in an armature where it is inaccessible except to an expert, and where it cannot be replaced except at the factory whence it emanated. CARE OF THE DIXIE MAGNETO The bearings of the magneto are provided with oil cups and a few drops of light oil every 1,000 miles are sufficient. The breaker lever should be lubricated every 1,000 miles with a drop of light oil, applied with a tooth-pick. The proper distance between the platinum points when separated should not exceed .020 or one-fiftieth of an inch. A gauge of the proper size is attached to the screwdriver furnished with the magneto. The platinum contacts should be kept clean and properly adjusted. Should the contacts become pitted, a fine file should be used to smooth them in order to permit them to come into perfect contact. The distributor block should be removed occasionally and inspected for an accumulation of carbon dust. The inside of the distributor block should be cleaned with a cloth moistened with gasoline and then wiped dry with a clean cloth. When replacing the block, care must be exercised in pushing the carbon brush into the socket. Do not pull out the carbon brushes in the distributor because you think there is not enough tension on the small brass springs. In order to obtain the most efficient results, the normal setting of the spark-plug points should not exceed .025 of an inch, and it is advisable to have the gap just right before a spark-plug is inserted. The spark-plug electrodes may be easily set by means of the gauge attached to the screwdriver. _The setting of the spark-plug points is an important function which is usually overlooked, with the result that the magneto is blamed when it is not at fault._ TIMING OF THE DIXIE MAGNETO [Illustration: Fig. 69A.--Sectional Views Outlining Construction of Dixie Magneto with Compound Distributor for Eight-Cylinder Engine Ignition.] In order to obtain the utmost efficiency from the engine, the magneto must be correctly timed to it. This operation is usually performed when the magneto is fitted to the engine at the factory. The correct setting may vary according to individuality of the engine, and some engines may require an earlier setting in order to obtain the best results. However, should the occasion arise to retime the magneto, the procedure is as follows: Rotate the crank-shaft of the engine until one of the pistons, preferably that of cylinder No. 1, is 1/16 of an inch ahead of the end of the compression stroke. With the timing lever in full retard position, the driving shaft of the magneto should be rotated in the direction in which it will be driven. The circuit breaker should be closely observed and when the platinum contact points are about to separate, the drive gear or coupling should be secured to the drive shaft of the magneto. Care should be taken not to alter the position of the magneto shaft when tightening the nut to secure the gear or coupling, after which the magneto should be secured to its base. Remove the distributor block and determine which terminal of the block is in contact with the carbon brush of the distributor finger and connect with plug wire leading to No. 1 cylinder to this terminal. Connect the remaining plug wires in turn according to the proper sequence of firing of the cylinders. (See the wiring diagram for a typical six-cylinder engine at Fig. 70.) A terminal on the end of the cover spring of the magneto is provided for the purpose of connecting the wire leading to a ground switch for stopping the engine. A special model or type of magneto is made for V engines which use a compound distributor construction instead of the simple type on the model illustrated and a different interior arrangement permits the production of four sparks per revolution of the rotors. This makes it possible to run the magneto slower than would be possible with the two-spark form. The application of two compound distributor magnetos of this type to a Thomas-Morse 135 horse-power motor of the eight-cylinder V pattern is clearly shown at Fig. 71. [Illustration: Fig. 70.--Wiring Diagram of Dixie Magneto Installation on Hall-Scott Six-Cylinder 125 Horse-Power Aeronautic Motor.] SPARK-PLUG DESIGN AND APPLICATION [Illustration: Fig. 71.--How Magneto Ignition is Installed on Thomas-Morse 135 Horse-Power Motor.] With the high-tension system of ignition the spark is produced by a current of high voltage jumping between two points which break the complete circuit, which would exist otherwise in the secondary coil and its external connections. The spark-plug is a simple device which consists of two terminal electrodes carried in a suitable shell member, which is screwed into the cylinder. Typical spark-plugs are shown in section at Fig. 72 and the construction can be easily understood. The secondary wire from the coil is attached to a terminal at the top of a central electrode member, which is supported in a bushing of some form of insulating material. The type shown at A employs a molded porcelain as an insulator, while that depicted at B uses a bushing of mica. The insulating bushing and electrode are housed in a steel body, which is provided with a screw thread at the bottom, by which means it is screwed into the combustion chamber. [Illustration: Fig. 72.--Spark-Plug Types Showing Construction and Arrangement of Parts.] When porcelain is used as an insulating material it is kept from direct contact with the metal portion by some form of yielding packing, usually asbestos. This is necessary because the steel and porcelain have different coefficients of expansion and some flexibility must be provided at the joints to permit the materials to expand differently when heated. The steel body of the plug which is screwed into the cylinder is in metallic contact with it and carries sparking points which form one of the terminals of the air gap over which the spark occurs. The current entering at the top of the plug cannot reach the ground, which is represented by the metal portion of the engine, until it has traversed the full length of the central electrode and overcome the resistance of the gap between it and the terminal point on the shell. The porcelain bushing is firmly seated against the asbestos packing by means of a brass screw gland which sets against a flange formed on the porcelain, and which screws into a thread at the upper portion of the plug body. The mica plug shown at B is somewhat simpler in construction than that shown at A. The mica core which keeps the central electrode separated from the steel body is composed of several layers of pure sheet mica wound around the steel rod longitudinally, and hundreds of stamped steel washers which are forced over this member and compacted under high pressure with some form of a binding material between them. Porcelain insulators are usually molded from high-grade clay and are approximately of the shapes desired by the designers of the plug. The central electrode may be held in place by mechanical means such as nuts, packings, and a shoulder on the rod, as shown at A. Another method sometimes used is to cement the electrode in place by means of some form of fire-clay cement. Whatever method of fastening is used, it is imperative that the joints be absolutely tight so that no gas can escape at the time of explosion. Porcelain is the material most widely used because it can be glazed so that it will not absorb oil, and it is subjected to such high temperature in baking that it is not liable to crack when heated. The spark-plugs may be screwed into any convenient part of the combustion chamber, the general practice being to install them in the caps over the inlet valves, or in the side of the combustion chamber, so the points will be directly in the path of the entering fresh gases from the carburetor. Other insulating materials sometimes used are glass, steatite (which is a form of soapstone) and lava. Mica and porcelain are the two common materials used because they give the best results. Glass is liable to crack, while lava or the soapstone insulating bushings absorb oil. The spark gap of the average plug is equal to about 1/32 of an inch for coil ignition and 1/40 of an inch when used in magneto circuits. A simple gauge for determining the gap setting is the thickness of an ordinary visiting card for magneto plugs, or a space equal to the thickness of a worn dime for a coil plug. The insulating bushings are made in a number of different ways, and while details of construction vary, spark-plugs do not differ essentially in design. The dimensions of the standardized plug recommended by the S. A. E. are shown at Fig. 73. [Illustration: Fig. 73.--Standard Airplane Engine Plug Suggested by S. A. E. Standards Committee.] It is often desirable to have a water-tight joint between the high-tension cable and the terminal screw on top of the insulating bushing of the spark-plug, especially in marine applications. The plug shown at C, Fig. 72, is provided with an insulating member or hood of porcelain, which is secured by a clip in such a manner that it makes a water-tight connection. Should the porcelain of a conventional form of plug become covered with water or dirty oil, the high-tension current is apt to run down this conducting material on the porcelain and reach the ground without having to complete its circuit by jumping the air gap and producing a spark. It will be evident that wherever a plug is exposed to the elements, which is often the case in airplane service, that it should be protected by an insulating hood which will keep the insulator dry and prevent short circuiting of the spark. The same end can be attained by slipping an ordinary rubber nipple over the porcelain insulator of any conventional plug and bringing up one end over the cable. TWO-SPARK IGNITION On most aviation engines, especially those having large cylinders, it is sometimes difficult to secure complete combustion by using a single-spark plug. If the combustion is not rapid the efficiency of the engine will be reduced proportionately. The compressed charge in the cylinder does not ignite all at once or instantaneously, as many assume, but it is the strata of gas nearest the plug which is ignited first. This in turn sets fire to consecutive layers of the charge until the entire mass is aflame. One may compare the combustion of gas in the gas-engine cylinder to the phenomenon which obtains when a heavy object is thrown into a pool of still water. First a small circle is seen at the point where the object has passed into the water, this circle in turn inducing other and larger circles until the whole surface of the pool has been agitated from the one central point. The method of igniting the gas is very similar, as the spark ignites the circle of gas immediately adjacent to the sparking point, and this circle in turn ignites a little larger one concentric with it. The second circle of flame sets fire to more of the gas, and finally the entire contents of the combustion chamber are burning. While ordinarily combustion is sufficiently rapid with a single plug so that the proper explosion is obtained at moderate engine speeds, if the engine is working fast and the cylinders are of large capacity more power may be obtained by setting fire to the mixture at two different points instead of but one. This may be accomplished by using two sparking-plugs in the cylinder instead of one, and experiments have shown that it is possible to gain from twenty-five to thirty per cent. in motor power at high speed with two-spark plugs, because the combustion of gas is accelerated by igniting the gas simultaneously in two places. The double-plug system on airplane engines is also a safeguard, as in event of failure of one plug in the cylinder the other would continue to fire the gas, and the engine will continue to function properly. In using magneto ignition some precautions are necessary relating to wiring and also the character of the spark-plugs employed. The conductor should be of good quality, have ample insulation, and be well protected from accumulations of oil, which would tend to decompose rubber insulation. It is customary to protect the wiring by running it through the conduits of fiber or metal tubing lined with insulating material. Multiple strand cables should be used for both primary and secondary wiring, and the insulation should be of rubber at least 3/16 inch thick. The spark-plugs commonly used for battery and coil ignition cannot always be employed when a magneto is fitted. The current produced by the mechanical generator has a greater amperage and more heat value than that obtained from transformer coils excited by battery current. The greater heat may burn or fuse the slender points used on some battery plugs and heavier electrodes are needed to resist the heating effect of the more intense arc. While the current has greater amperage it is not of as high potential or voltage as that commonly produced by the secondary winding of an induction coil, and it cannot overcome as much of a gap. Manufacturers of magneto plugs usually set the spark points about 1/64 of an inch apart. The most efficient magneto plug has a plurality of points so that when the distance between one set becomes too great the spark will take place between one of the other pairs of electrodes which are not separated by so great an air space. [Illustration: Fig. 74.--Special Mica Plug for Aviation Engines.] SPECIAL PLUGS FOR AIRPLANE WORK Airplane work calls for special construction of spark-plugs, owing to the high compression used in the engines and the fact that they are operated on open throttle practically all the time, thus causing a great deal of heat to be developed. The plug shown at Fig. 74 was recently described in "The Automobile," and has been devised especially for airplane engines and automobile racing power plants. The core C is built up of mica washers, and has square shoulders. As mica washers of different sizes may be used, and accurate machining, such as is necessary with conical clamping surfaces, is not required, the plug can be produced economically. The square shoulders of the core afford two gasket seats, and when the core is clamped in the shell by means of check nut E, it is accurately centered and a tight joint is formed. This construction also makes a shorter plug than where conical fits are used, thus improving the heat radiation through the stem. The lower end of the shell is provided with a baffle plate O, which tends to keep the oil away from the mica. There are perforations L in this baffle plate to prevent burnt gases being pocketed behind the baffle plate and pre-igniting the new charge. This construction also brings the firing point out into the firing chamber of the engine, and has all the other advantages of a closed-end plug. The stem P is made of brass or copper, on account of their superior heat conductivity, and the electrode J is swedged into the bottom of the stem, as shown at K, in a secure manner. The shell is finned, as shown at G, to provide greater heat radiating surface. There is also a fin F at the top of the stem, to increase the radiation of heat from the stem and electrode. The top of this finned portion is slightly countersunk, and the stem is riveted into same, thereby reducing the possibility of leakage past the threads on the stem. This finned portion is necked at A to take a slip terminal. In building up the core a small section of washers, I, is built up before the mica insulating tube D is placed on. This construction gives a better support to section I. Baffle plate O is bored out to allow the electrode J to pass through, and the clearance between baffle plate and electrode is made larger than the width of the gap between the firing points, so that there is no danger of the spark jumping from the electrode to the baffle plate. This plug will be furnished either with or without the finned portion, to meet individual requirements. The manufacturers lay special stress upon the simplicity of construction and upon the method of clamping, which is claimed to make the plug absolutely gas-tight. CHAPTER VII Why Lubrication Is Necessary--Friction Defined--Theory of Lubrication--Derivation of Lubricants--Properties of Cylinder Oils--Factors Influencing Lubrication System Selection--Gnome Type Engines Use Castor Oil--Hall-Scott Lubrication System--Oil Supply by Constant Level Splash System--Dry Crank-Case System Best for Airplane Engines--Why Cooling Systems Are Necessary-- Cooling Systems Generally Applied--Cooling by Positive Pump Circulation--Thermo-Syphon System--Direct Air-Cooling Methods-- Air-Cooled Engine Design Considerations. WHY LUBRICATION IS NECESSARY The importance of minimizing friction at the various bearing surfaces of machines to secure mechanical efficiency is fully recognized by all mechanics, and proper lubricity of all parts of the mechanism is a very essential factor upon which the durability and successful operation of the motor car power plant depends. All of the moving members of the engine which are in contact with other portions, whether the motion is continuous or intermittent, of high or low velocity, or of rectilinear or continued rotary nature, should be provided with an adequate supply of oil. No other assemblage of mechanism is operated under conditions which are so much to its disadvantage as the motor car, and the tendency is toward a simplification of oiling methods so that the supply will be ample and automatically applied to the points needing it. In all machinery in motion the members which are in contact have a tendency to stick to each other, and the very minute projections which exist on even the smoothest of surfaces would have a tendency to cling or adhere to each other if the surfaces were not kept apart by some elastic and unctuous substance. This will flow or spread out over the surfaces and smooth out the inequalities existing which tend to produce heat and retard motion of the pieces relative to each other. A general impression which obtains is that well machined surfaces are smooth, but while they are apparently free from roughness, and no projections are visible to the naked eye, any smooth bearing surface, even if very carefully ground, will have a rough appearance if examined with a magnifying glass. An exaggerated condition to illustrate this point is shown at Fig. 75. The amount of friction will vary in proportion to the pressure on the surfaces in contact and will augment as the loads increase; the rougher surfaces will have more friction than smoother ones and soft bodies will produce more friction than hard substances. FRICTION DEFINED Friction is always present in any mechanism as a resisting force that tends to retard motion and bring all moving parts to a state of rest. The absorption of power by friction may be gauged by the amount of heat which exists at the bearing points. Friction of solids may be divided into two classes: sliding friction, such as exists between the piston and cylinder, or the bearings of a gas-engine, and rolling friction, which is that present when the load is supported by ball or roller bearings, or that which exists between the tires or the driving wheels and the road. Engineers endeavor to keep friction losses as low as possible, and much care is taken in all modern airplane engines to provide adequate methods of lubrication, or anti-friction bearings at all points where considerable friction exists. THEORY OF LUBRICATION The reason a lubricant is supplied to bearing points will be easily understood if one considers that these elastic substances flow between the close fitting surfaces, and by filling up the minute depressions in the surfaces and covering the high spots act as a cushion which absorbs the heat generated and takes the wear instead of the metallic bearing surface. The closer the parts fit together the more fluid the lubricant must be to pass between their surfaces, and at the same time it must possess sufficient body so that it will not be entirely forced out by the pressure existing between the parts. [Illustration: Fig. 75.--Showing Use of Magnifying Glass to Demonstrate that Apparently Smooth Metal Surfaces May Have Minute Irregularities which Produce Friction.] Oils should have good adhesive, as well as cohesive, qualities. The former are necessary so that the oil film will cling well to the surfaces of the bearings; the latter, so the oil particles will cling together and resist the tendency to separation which exists all the time the bearings are in operation. When used for gas-engine lubrication the oil should be capable of withstanding considerable heat in order that it will not be vaporized by the hot portions of the cylinder. It should have sufficient cold test so that it will remain fluid and flow readily at low temperature. Lubricants should be free from acid, or alkalies, which tend to produce a chemical action with metals and result in corrosion of the parts to which they are applied. It is imperative that the oil be exactly the proper quality and nature for the purpose intended and that it be applied in a positive manner. The requirements may be briefly summarized as follows: First--It must have sufficient body to prevent seizing of the parts to which it is applied and between which it is depended upon to maintain an elastic film, and yet it must not have too much viscosity, in order to minimize the internal or fluid friction which exists between the particles of the lubricant itself. Second--The lubricant must not coagulate or gum; must not injure the parts to which it is applied, either by chemical action or by producing injurious deposits, and it should not evaporate readily. Third--The character of the work will demand that the oil should not vaporize when heated or thicken to such a point that it will not flow readily when cold. Fourth--The oil must be free from acid, alkalies, animal or vegetable fillers, or other injurious agencies. Fifth--It must be carefully selected for the work required and should be a good conductor of heat. DERIVATION OF LUBRICANTS The first oils which were used for lubricating machinery were obtained from animal and vegetable sources, though at the present time most unguents are of mineral derivation. Lubricants may exist as fluids, semifluids, or solids. The viscosity will vary from light spindle or dynamo oils, which have but little more body than kerosene, to the heaviest greases and tallows. The most common solid employed as a lubricant is graphite, sometimes termed "plumbago" or "black lead." This substance is of mineral derivation. The disadvantage of oils of organic origin, such as those obtained from animal fats or vegetable substances, is that they will absorb oxygen from the atmosphere, which causes them to thicken or become rancid. Such oils have a very poor cold test, as they solidify at comparatively high temperatures, and their flashing point is so low that they cannot be used at points where much heat exists. In most animal oils various acids are present in greater or less quantities, and for this reason they are not well adapted for lubricating metallic surfaces which may be raised high enough in temperature to cause decomposition of the oils. Lubricants derived from the crude petroleum are called "Oleonaphthas" and they are a product of the process of refining petroleum through which gasoline and kerosene are obtained. They are of lower cost than vegetable or animal oil, and as they are of non-organic origin, they do not become rancid or gummy by constant exposure to the air, and they will have no corrosive action on metals because they contain no deleterious substances in chemical composition. By the process of fractional distillation mineral oils of all grades can be obtained. They have a lower cold and higher flash test and there is not the liability of spontaneous combustion that exists with animal oils. The organic oils are derived from fatty substances, which are present in the bodies of all animals and in some portions of plants. The general method of extracting oil from animal bodies is by a rendering process, which consists of applying sufficient heat to liquefy the oil and then separating it from the tissue with which it is combined by compression. The only oil which is used to any extent in gas-engine lubrication that is not of mineral derivation is castor oil. This substance has been used on high-speed racing automobile engines and on airplane power plants. It is obtained from the seeds of the castor plant, which contain a large percentage of oil. Among the solid substances which may be used for lubricating purposes may be mentioned tallow, which is obtained from the fat of animals, and graphite and soapstone, which are of mineral derivation. Tallow is never used at points where it will be exposed to much heat, though it is often employed as a filler for greases used in transmission gearing of autos. Graphite is sometimes mixed with oil and applied to cylinder lubrication, though it is most often used in connection with greases in the landing gear parts and for coating wires and cables of the airplane. Graphite is not affected by heat, cold, acids, or alkalies, and has a strong attraction for metal surfaces. It mixes readily with oils and greases and increases their efficiency in many applications. It is sometimes used where it would not be possible to use other lubricants because of extremes of temperature. The oils used for cylinder lubrication are obtained almost exclusively from crude petroleum derived from American wells. Special care must be taken in the selection of crude material, as every variety will not yield oil of the proper quality to be used as a cylinder lubricant. The crude petroleum is distilled as rapidly as possible with fire heat to vaporize off the naphthas and the burning oils. After these vapors have been given off superheated steam is provided to assist in distilling. When enough of the light elements have been eliminated the residue is drawn off, passed through a strainer to free it from grit and earthy matters, and is afterwards cooled to separate the wax from it. This is the dark cylinder oil and is the grade usually used for steam-engine cylinders. PROPERTIES OF CYLINDER OILS The oil that is to be used in the gasoline engine must be of high quality, and for that reason the best grades are distilled in a vacuum that the light distillates may be separated at much lower temperatures than ordinary conditions of distilling permit. If the degree of heat is not high the product is not so apt to decompose and deposit carbon. If it is desired to remove the color of the oil which is caused by free carbon and other impurities it can be accomplished by filtering the oil through charcoal. The greater the number of times the oil is filtered, the lighter it will become in color. The best cylinder oils have flash points usually in excess of 500 degrees F., and while they have a high degree of viscosity at 100 degrees F. they become more fluid as the temperature increases. The lubricating oils obtained by refining crude petroleum may be divided into three classes: First--The natural oils of great body which are prepared for use by allowing the crude material to settle in tanks at high temperature and from which the impurities are removed by natural filtration. These oils are given the necessary body and are free from the volatile substances they contain by means of superheated steam which provides a source of heat. Second--Another grade of these natural oils which are filtered again at high temperatures and under pressure through beds of animal charcoal to improve their color. Third--Pale, limpid oils, obtained by distillation and subsequent chemical treatment from the residuum produced in refining petroleum to obtain the fuel oils. Authorities agree that any form of mixed oil in which animal and mineral lubricants are combined should never be used in the cylinder of a gas engine as the admixture of the lubricants does not prevent the decomposition of the organic oil into the glycerides and fatty acids peculiar to the fat used. In a gas-engine cylinder the flame tends to produce more or less charring. The deposits of carbon will be much greater with animal oils than with those derived from the petroleum base because the constituents of a fat or tallow are not of the same volatile character as those which comprise the hydro-carbon oils which will evaporate or volatilize before they char in most instances. FACTORS INFLUENCING LUBRICATION SYSTEM SELECTION The suitability of oil for the proper and efficient lubrication of all internal combustion engines is determined chiefly by the following factors: 1. Type of cooling system (operating temperatures). 2. Type of lubricating system (method of applying oil to the moving parts). 3. Rubbing speeds of contact surfaces. Were the operating temperatures, bearing surface speeds and lubrication systems identical, a single oil could be used in all engines with equal satisfaction. The only change then necessary in viscosity would be that due to climatic conditions. As engines are now designed, only three grades of oil are necessary for the lubrication of all types with the exception of Knight, air-cooled and some engines which run continuously at full load. In the specification of engine lubricants the feature of load carried by the engine should be carefully considered. _Full Load Engines._ 1. Marine. 2. Racing automobile. 3. Aviation. 4. Farm tractor. 5. Some stationary. _Variable Load Engines._ 1. Pleasure automobile. 2. Commercial vehicle. 3. Motor cycle. 4. Some stationary. Of the forms outlined, the only one we have any immediate concern about is the airplane power plant. The Platt & Washburn Refining Company, who have made a careful study of the lubrication problem as applied to all types of engines, have found a peculiar set of conditions to apply to oiling high-speed constant-duty or "full-load" engines. Modern airplane engines are designed to operate continuously at a fairly uniform high rotative speed and at full load over long periods of time. As a sequence to this heavy duty the operating temperatures are elevated. For the sake of extreme lightness in weight of all parts, very thin alloy steel aluminum or cast iron pistons are fitted and the temperature of the thin piston heads at the center reaches anywhere between 600° and 1,400° Fahr., as in automobile racing engines. Freely exposed to such intense heat hydro-carbon oils are partially "cracked" into light and heavy products or polymerized into solid hydro-carbons. From these facts it follows that only heavy mineral oils of low carbon residue and of the greatest chemical purity and stability should be used to secure good lubrication. In all cases the oil should be sufficiently heavy to assure the highest horse-power and fuel and oil economy compatible with perfect lubrication, avoiding, at the same time, carbonization and ignition failure. When aluminum pistons are used their superior heat-conducting properties aid materially in reducing the rate of oil destruction. The extraordinary evolutions described by airplanes in flight make it a matter of vital necessity to operate engines inclined at all angles to the vertical as well as in an upside-down position. To meet this situation lubricating systems have been elaborated so as to deliver an abundance of oil where needed and to eliminate possible flooding of cylinders. This is done by applying a full force feed system, distributing oil under considerable pressure to all working parts. Discharged through the bearings, the oil drains down to the suction side of a second pump located in the bottom of the base chamber. This pump being of greater capacity than the first prevents the accumulation of oil in the crank-case, and forces it to a separate oil reservoir-cooler, whence it flows back in rapid circulation to the pump feeding the bearings. With this arrangement positive lubrication is entirely independent of engine position. The lubricating system of the Thomas-Morse aviation engines, which is shown at Fig. 76, is typical of current practice. [Illustration: Fig. 76.--Pressure Feed Oiling System of Thomas Aviation Engine Includes Oil Cooling Means.] GNOME TYPE ENGINES USE CASTOR OIL The construction and operation of rotative radial cylinder engines introduce additional difficulties of lubrication to those already referred to and merit especial attention. Owing to the peculiar alimentation systems of Gnome type engines, atomized gasoline mixed with air is drawn through the hollow stationary crank-shaft directly into the crank-case which it fills on the way to the cylinders. Therein lies the trouble. Hydrocarbon oils are soon dissolved by the gasoline and washed off, leaving the bearing surfaces without adequate protection and exposed to instant wear and destruction. So castor oil is resorted to as an indispensable but unfortunate compromise. Of vegetable origin, it leaves a much more bulky carbon deposit in the explosion chambers than does mineral oil and its great affinity for oxygen causes the formation of voluminous gummy deposit in the crank-case. Engines employing it need to be dismounted and thoroughly scraped out at frequent intervals. It is advisable to use only unblended chemically pure castor oil in rotative engines, first by virtue of its insolubility in gasoline and second because its extra heavy body can resist the high temperature of air-cooled cylinders. HALL-SCOTT LUBRICATION SYSTEM [Illustration: Fig. 77.--Diagram of Oiling System, Hall-Scott Type A 125 Horse-Power Engine.] The oiling system of the Hall-Scott type A-5 125 horse-power engine is clearly shown at Fig. 77. It is completely described in the instruction book issued by the company from which the following extracts are reproduced by permission. Crank-shaft, connecting rods and all other parts within the crank-case and cylinders are lubricated directly or indirectly by a force-feed oiling system. The cylinder walls and wrist pins are lubricated by oil spray thrown from the lower end of connecting rod bearings. This system is used only upon A-5 engines. Upon A-7a and A-5a engines a small tube supplies oil from connecting rod bearing directly upon the wrist pin. The oil is drawn from the strainer located at the lowest portion of the lower crank-case, forced around the main intake manifold oil jacket. From here it is circulated to the main distributing pipe located along the lower left hand side of upper crank-case. The oil is then forced directly to the lower side of crank-shaft, through holes drilled in each main bearing cup. Leakage from these main bearings is caught in scuppers placed upon the cheeks of the crank-shafts furnishing oil under pressure to the connecting rod bearings. A-7a and A-5a engines have small tubes leading from these bearings which convey the oil under pressure to the wrist pins. A bi-pass located at the front end of the distributing oil pipe can be regulated to lessen or raise the pressure. By screwing the valve in, the pressure will raise and more oil will be forced to the bearings. By unscrewing, pressure is reduced and less oil is fed. A-7a and A-5a engines have oil relief valves located just off of the main oil pump in the lower crank-case. This regulates the pressure at all times so that in cold weather there will be no danger of bursting oil pipes due to excessive pressure. If it is found the oil pressure is not maintained at a high enough level, inspect this valve. A stronger spring will not allow the oil to bi-pass so freely, and consequently the pressure will be raised; a weaker spring will bi-pass more oil and reduce the oil pressure materially. Independent of the above-mentioned system, a small, directly driven rotary oiler feeds oil to the base of each individual cylinder. The supply of oil is furnished by the main oil pump located in the lower crank-case. A small sight-feed regulator is furnished to control the supply of oil from this oiler. This instrument should be placed higher than the auxiliary oil distributor itself to enable the oil to drain by gravity feed to the oiler. If there is no available place with the necessary height in the front seat of plane, connect it directly to the intake L fitting on the oiler in an upright position. It should be regulated with full open throttle to maintain an oil level in the glass, approximately half way. An oil pressure gauge is provided. This should be run to the pilot's instrument board. The gauge registers the oil pressure upon the bearings, also determining its circulation. Strict watch should be maintained of this instrument by pilot, and if for any reason its hand should drop to 0 the motor should be immediately stopped and the trouble found before restarting engine. Care should be taken that the oil does not work up into the gauge, as it will prevent the correct gauge registering of oil pressure. The oil pressure will vary according to weather conditions and viscosity of oil used. In normal weather, with the engine properly warmed up, the pressure will register on the oil gauge from 5 to 10 pounds when the engine is turning from 1,275 to 1,300 r. p. m. This does not apply to all aviation engines, however, as the proper pressure advised for the Curtiss OX-2 motor is from 40 to 55 pounds at the gauge. The oil sump plug is located at the lowest point of the lower crank-case. This is a combination dirt, water and sediment trap. It is easily removed by unscrewing. Oil is furnished mechanically to the cam-shaft housing under pressure through a small tube leading from the main distributing pipe at the propeller end of engine directly into the end of cam-shaft housing. The opposite end of this housing is amply relieved to allow the oil to rapidly flow down upon cam-shaft, magneto, pinion-shaft, and crank-shaft gears, after which it returns to lower crank-case. An outside overflow pipe is also provided to carry away the surplus oil. DRAINING OIL FROM CRANK-CASE The oil strainer is placed at the lowest point of the lower crank-case. This strainer should be removed after every five to eight hours running of the engine and cleaned thoroughly with gasoline. It is also advisable to squirt distillate up into the case through the opening where the strainer has been removed. Allow this distillate to drain out thoroughly before replacing the plug with strainer attached. Be sure gasket is in place on plug before replacing. Pour new oil in through either of the two breather pipes on exhaust side of motor. Be sure to replace strainer screens if removed. If, through oversight, the engine does not receive sufficient lubrication and begins to heat or pound, it should be stopped immediately. After allowing engine to cool pour at least three gallons of oil into oil sump. Fill radiator with water after engine has cooled. Should there be apparent damage, the engine should be thoroughly inspected immediately without further running. If no obvious damage has been done, the engine should be given a careful examination at the earliest opportunity to see that the running without oil has not burned the bearings or caused other trouble. Oils best adapted for Hall-Scott engines have the following properties: A flash test of not less than 400° F.; viscosity of not less than 75 to 85 taken at 21° F. with Saybolt's Universal Viscosimeter. _Zeroline heavy duty oil_, manufactured by the Standard Oil Company of California; also, _Gargoyle mobile B oil_, manufactured by the Vacuum Oil Company, both fulfill the above specifications. One or the other of these oils can be obtained all over the world. Monogram extra heavy is also recommended. OIL SUPPLY BY CONSTANT LEVEL SPLASH SYSTEM The splash system of lubrication that depends on the connecting rod to distribute the lubricant is one of the most successful and simplest forms for simple four- and six-cylinder vertical automobile engines, but is not as well adapted to the oiling of airplane power plants for reasons previously stated. If too much oil is supplied the surplus will work past the piston rings and into the combustion chamber, where it will burn and cause carbon deposits. Too much oil will also cause an engine to smoke and an excess of lubricating oil is usually manifested by a bluish-white smoke issuing from the exhaust. A good method of maintaining a constant level of oil for the successful application of the splash system is shown at Fig. 78. The engine base casting includes a separate chamber which serves as an oil container and which is below the level of oil in the crank-case. The lubricant is drawn from the sump or oil container by means of a positive oil pump which discharges directly into the engine case. The level is maintained by an overflow pipe which allows all excess lubricant to flow back into the oil container at the bottom of the cylinder. Before passing into the pump again the oil is strained or filtered by a screen of wire gauze and all foreign matter removed. Owing to the rapid circulation of the oil it may be used over and over again for quite a period of time. The oil is introduced directly into the crank-case by a breather pipe and the level is indicated by a rod carried by a float which rises when the container is replenished and falls when the available supply diminishes. It will be noted that with such system the only apparatus required besides the oil tank which is cast integral with the bottom of the crank-case is a suitable pump to maintain circulation of oil. This member is always positively driven, either by means of shaft and universal coupling or direct gearing. As the system is entirely automatic in action, it will furnish a positive supply of oil at all desired points, and it cannot be tampered with by the inexpert because no adjustments are provided or needed. DRY CRANK-CASE SYSTEM BEST FOR AIRPLANE ENGINES [Illustration: Fig. 78.--Sectional View of Typical Motor Showing Parts Needing Lubrication and Method of Applying Oil by Constant Level Splash System. Note also Water Jacket and Spaces for Water Circulation.] In most airplane power plants it is considered desirable to supply the oil directly to the parts needing it by suitable leads instead of depending solely upon the distributing action of scoops on the connecting rod big ends. A system of this nature is shown at Fig. 77. The oil is carried in the crank-case, as is common practice, but the normal oil level is below the point where it will be reached by the connecting rod. It is drawn from the crank-case by a plunger pump which directs it to a manifold leading directly to conductors which supply the main journals. After the oil has been used on these points it drains back into the bottom of the crank-case. An excess is provided which is supplied to the connecting rod ends by passages drilled into the webs of the crank-shaft and part way into the crank-pins as shown by the dotted lines. The oil which is present at the connecting rod crank-pins is thrown off by centrifugal force and lubricates the cylinder walls and other internal parts. Regulating screws are provided so that the amount of oil supplied the different points may be regulated at will. A relief check valve is installed to take care of excess lubricant and to allow any oil that does not pass back into the pipe line to overflow or bi-pass into the main container. [Illustration: Fig. 79.--Pressure Feed Oil-Supply System of Airplane Power Plants has Many Good Features.] A simple system of this nature is shown graphically in a phantom view of the crank-case at Fig. 79, in which the oil passages are made specially prominent. The oil is taken from a reservoir at the bottom of the engine base by the usual form of gear oil pump and is supplied to a main feed manifold which extends the length of the crank-case. Individual conductors lead to the five main bearings, which in turn supply the crank-pins by passages drilled through the crank-shaft web. In this power plant the connecting rods are hollow section bronze castings and the passage through the center of the connecting rod serves to convey the lubricant from the crank-pins to the wrist-pins. The cylinder walls are oiled by the spray of lubricant thrown off the revolving crank-shaft by centrifugal force. Oil projection by the dippers on the connecting rod ends from constant level troughs is unequal upon the cylinder walls of the two-cylinder blocks of an eight- or twelve-cylinder V engine. This gives rise, on one side of the engine, to under-lubrication, and, on the other side, to over-lubrication, as shown at Fig. 80, A. This applies to all modifications of splash lubricating systems. When a force-feed lubricating system is used, the oil, escaping past the cheeks of both ends of the crank-pin bearings, is thrown off at a tangent to the crank-pin circle in all directions, supplying the cylinders on both sides with an equal quantity of oil, as at Fig. 80, B. WHY COOLING SYSTEMS ARE NECESSARY The reader should understand from preceding chapters that the power of an internal-combustion motor is obtained by the rapid combustion and consequent expansion of some inflammable gas. The operation in brief is that when air or any other gas or vapor is heated, it will expand and that if this gas is confined in a space which will not permit expansion, pressure will be exerted against all sides of the containing chamber. The more a gas is heated, the more pressure it will exert upon the walls of the combustion chamber it confines. Pressure in a gas may be created by increasing its temperature and inversely heat may be created by pressure. When a gas is compressed its total volume is reduced and the temperature is augmented. [Illustration: Fig. 80.--Why Pressure Feed System is Best for Eight-Cylinder Vee Airplane Engines.] The efficiency of any form of heat engine is determined by the power obtained from a certain fuel consumption. A definite amount of energy will be liberated in the form of heat when a pound of any fuel is burned. The efficiency of any heat engine is proportional to the power developed from a definite quantity of fuel with the least loss of thermal units. If the greater proportion of the heat units derived by burning the explosive mixture could be utilized in doing useful work, the efficiency of the gasoline engine would be greater than that of any other form of energizing power. There is a great loss of heat from various causes, among which can be cited the reduction of pressure through cooling the motor and the loss of heat through the exhaust valves when the burned gases are expelled from the cylinder. The loss through the water jacket of the average automobile power plant is over 50 per cent. of the total fuel efficiency. This means that more than half of the heat units available for power are absorbed and dissipated by the cooling water. Another 16 per cent. is lost through the exhaust valve, and but 33-1/3 per cent. of the heat units do useful work. The great loss of heat through the cooling systems cannot be avoided, as some method must be provided to keep the temperature of the engine within proper bounds. It is apparent that the rapid combustion and continued series of explosions would soon heat the metal portions of the engine to a red heat if some means were not taken to conduct much of this heat away. The high temperature of the parts would burn the lubricating oil, even that of the best quality, and the piston and rings would expand to such a degree, especially when deprived of oil, that they would seize in the cylinder. This would score the walls, and the friction which ensued would tend to bind the parts so tightly that the piston would stick, bearings would be burned out, the valves would warp, and the engine would soon become inoperative. [Illustration: Fig. 81.--Operating Temperatures of Automobile Engine Parts Useful as a Guide to Understand Airplane Power Plant Heat.] The best temperature to secure efficient operation is one on which considerable difference of opinion exists among engineers. The fact that the efficiency of an engine is dependent upon the ratio of heat converted into useful work compared to that generated by the explosion of the gas is an accepted fact. It is very important that the engine should not get too hot, and on the other hand it is equally vital that the cylinders be not robbed of too much heat. The object of cylinder cooling is to keep the temperature of the cylinder below the danger point, but at the same time to have it as high as possible to secure maximum power from the gas burned. The usual operating temperatures of an automobile engine are shown at Fig. 81, and this can be taken as an approximation of the temperatures apt to exist in an airplane engine of conventional design as well when at ground level or not very high in the air. The newer very high compression airplane engines in which compressions of eight or nine atmospheres are used, or about 125 pounds per square inch, will run considerably hotter than the temperatures indicated. COOLING SYSTEMS GENERALLY APPLIED There are two general systems of engine cooling in common use, that in which water is heated by the absorption of heat from the engine and then cooled by air, and the other method in which the air is directed onto the cylinder and absorbs the heat directly instead of through the medium of water. When the liquid is employed in cooling it is circulated through jackets which surround the cylinder casting and the water may be kept in motion by two methods. The one generally favored is to use a positive circulating pump of some form which is driven by the engine to keep the water in motion. The other system is to utilize a natural principle that heated water is lighter than cold liquid and that it will tend to rise to the top of the cylinder when it becomes heated to the proper temperature and cooled water takes its place at the bottom of the water jacket. Air-cooling methods may be by radiation or convection. In the former case the effective outer surface of the cylinder is increased by the addition of flanges machined or cast thereon, and the air is depended on to rise from the cylinder as heated and be replaced by cooler air. This, of course, is found only on stationary engines. When a positive air draught is directed against the cylinder by means of the propeller slip stream in an airplane, cooling is by convection and radiation both. Sometimes the air draught may be directed against the cylinder walls by some form of jacket which confines it to the heated portions of the cylinder. COOLING BY POSITIVE WATER CIRCULATION [Illustration: Fig. 82.--Water Cooling of Salmson Seven-Cylinder Radial Airplane Engine.] A typical water-cooling system in which a pump is depended upon to promote circulation of the cooling liquid is shown at Figs. 82 and 83. The radiator is carried at the front end of the fuselage in most cases, and serves as a combined water tank and cooler, but in some cases it is carried at the side of the engine, as in Fig. 84, or attached to the central portion of the aerofoil or wing structure. It is composed of an upper and lower portion joined together by a series of pipes which may be round and provided with a series of fins to radiate the heat, or which may be flat in order to have the water pass through in thin sheets and cool it more easily. Cellular or honeycomb coolers are composed of a large number of bent tubes which will expose a large area of surface to the cooling influence of the air draught forced through the radiator either by the forward movement of the vehicle or by some type of fan. The cellular and flat tube types have almost entirely displaced the flange tube radiators which were formerly popular because they cool the water more effectively, and may be made lighter than the tubular radiator could be for engines of the same capacity. [Illustration: Fig. 83.--How Water Cooling System of Thomas Airplane Engine is Installed in Fuselage.] The water is drawn from the lower header of the radiator by the pump and is forced through a manifold to the lower portion of the water jackets of the cylinder. It becomes heated as it passes around the cylinder walls and combustion chambers and the hot water passes out of the top of the water jacket to the upper portion of the radiator. Here it is divided in thin streams and directed against comparatively cool metal which abstracts the heat from the water. As it becomes cooler it falls to the bottom of the radiator because its weight increases as the temperature becomes lower. By the time it reaches the lower tank of the radiator it has been cooled sufficiently so that it may be again passed around the cylinders of the motor. The popular form of circulating pump is known as the "centrifugal type" because a rotary impeller of paddle-wheel form throws water which it receives at a central point toward the outside and thus causes it to maintain a definite rate of circulation. The pump is always a separate appliance attached to the engine and driven by positive gearing or direct-shaft connection. The centrifugal pump is not as positive as the gear form, and some manufacturers prefer the latter because of the positive pumping features. They are very simple in form, consisting of a suitable cast body in which a pair of spur pinions having large teeth are carried. One of these gears is driven by suitable means, and as it turns the other member they maintain a flow of water around the pump body. The pump should always be installed in series with the water pipe which conveys the cool liquid from the lower compartment of the radiator to the coolest portion of the water jacket. [Illustration: Fig. 84.--Finned Tube Radiators at the Side of Hall-Scott Airplane Power Plant Installed in Standard Fuselage.] WATER CIRCULATION BY NATURAL SYSTEM Some automobile engineers contend that the rapid water circulation obtained by using a pump may cool the cylinders too much, and that the temperature of the engine may be reduced so much that the efficiency will be lessened. For this reason there is a growing tendency to use the natural method of water circulation as the cooling liquid is supplied to the cylinder jackets just below the boiling point and the water issues from the jacket at the top of the cylinder after it has absorbed sufficient heat to raise it just about to the boiling point. As the water becomes heated by contact with the hot cylinder and combustion-chamber walls it rises to the top of the water jacket, flows to the cooler, where enough of the heat is absorbed to cause it to become sensibly greater in weight. As the water becomes cooler, it falls to the bottom of the radiator and it is again supplied to the water jacket. The circulation is entirely automatic and continues as long as there is a difference in temperature between the liquid in the water spaces of the engine and that in the cooler. The circulation becomes brisker as the engine becomes hotter and thus the temperature of the cylinders is kept more nearly to a fixed point. With the thermosyphon system the cooling liquid is nearly always at its boiling point, whereas if the circulation is maintained by a pump the engine will become cooler at high speed and will heat up more at low speed. With the thermosyphon, or natural system of cooling, more water must be carried than with the pump-maintained circulation methods. The water spaces around the cylinders should be larger, the inlet and discharge water manifolds should have greater capacity, and be free from sharp corners which might impede the flow. The radiator must also carry more water than the form used in connection with the pump because of the brisker pump circulation which maintains the engine temperature at a lower point. Consideration of the above will show why the pump system is almost universally used in connection with airplane power plant cooling. DIRECT AIR-COOLING METHODS The earliest known method of cooling the cylinder of gas-engines was by means of a current of air passed through a jacket which confined it close to the cylinder walls and was used by Daimler on his first gas-engine. The gasoline engine of that time was not as efficient as the later form, and other conditions which materialized made it desirable to cool the engine by water. Even as gasoline engines became more and more perfected there has always existed a prejudice against air cooling, though many forms of engines have been used, both in automobile and aircraft applications where the air-cooling method has proven to be very practical. The simplest system of air cooling is that in which the cylinders are provided with a series of flanges which increase the effective radiating surface of the cylinder and directing an air-current from a fan against the flanges to absorb the heat. This increase in the available radiating surface of an air-cooled cylinder is necessary because air does not absorb heat as readily as water and therefore more surface must be provided that the excess heat be absorbed sufficiently fast to prevent distortion of the cylinders. Air-cooling systems are based on a law formulated by Newton, which is: "The rate for cooling for a body in a uniform current of air is directly proportional to the speed of the air current and the amount of radiating surface exposed to the cooling effect." AIR-COOLED ENGINE DESIGN CONSIDERATIONS [Illustration: Fig. 85.--Anzani Testing His Five-Cylinder Air Cooled Aviation Motor Installed in Bleriot Monoplane. Note Exposure of Flanged Cylinders to Propeller Slip Stream.] There are certain considerations which must be taken into account in designing an air-cooled engine, which are often overlooked in those forms cooled by water. Large valves must be provided to insure rapid expulsion of the flaming exhaust gas and also to admit promptly the fresh cool mixture from the carburetor. The valves of air-cooled engines are usually placed in the cylinder-head, in order to eliminate any pockets or sharp passages which would impede the flow of gas or retain some of the products of combustion and their heat. When high power is desired multiple-cylinder engines should be used, as there is a certain limit to the size of a successful air-cooled cylinder. Much better results are secured from those having small cubical contents because the heat from small quantities of gas will be more quickly carried off than from greater amounts. All successful engines of the aviation type which have been air-cooled have been of the multiple-cylinder type. An air-cooled engine must be placed in the fuselage, as at Fig. 85, in such a way that there will be a positive circulation of air around it all the time that it is in operation. The air current may be produced by the tractor screw at the front end of the motor, or by a suction or blower fan attached to the crank-shaft as in the Renault engine or by rotating the cylinders as in the Le Rhone and Gnome motors. Greater care is required in lubrication of the air-cooled cylinders and only the best quality of oil should be used to insure satisfactory oiling. The combustion chambers must be proportioned so that distribution of metal is as uniform as possible in order to prevent uneven expansion during increase in temperature and uneven contraction when the cylinder is cooled. It is essential that the inside walls of the combustion chamber be as smooth as possible because any sharp angle or projection may absorb sufficient heat to remain incandescent and cause trouble by igniting the mixture before the proper time. The best grades of cast iron or steel should be used in the cylinder and piston and the machine work must be done very accurately so the piston will operate with minimum friction in the cylinder. The cylinder bore should not exceed 4-1/2 or 5 inches and the compression pressure should never exceed 75 pounds absolute, or about five atmospheres, or serious overheating will result. As an example of the care taken in disposing of the exhaust gases in order to obtain practical air-cooling, some cylinders are provided with a series of auxiliary exhaust ports uncovered by the piston when it reaches the end of its power stroke. The auxiliary exhaust ports open just as soon as the full force of the explosion has been spent and a portion of the flaming gases is discharged through the ports in the bottom of the cylinder. Less of the exhaust gases remains to be discharged through the regular exhaust member in the cylinder-head and this will not heat the walls of the cylinder nearly as much as the larger quantity of hot gas would. That the auxiliary exhaust port is of considerable value is conceded by many designers of fixed and fan-shaped air-cooled motors for airplanes. Among the advantages stated for direct air cooling, the greatest is the elimination of cooling water and its cooling auxiliaries, which is a factor of some moment, as it permits considerable reduction in horse-power-weight ratio of the engine, something very much to be desired. In the temperate zone, where the majority of airplanes are used, the weather conditions change in a very few months from the warm summer to the extreme cold winter, and when water-cooled systems are employed it is necessary to add some chemical substance to the water to prevent it from freezing. The substances commonly employed are glycerine, wood alcohol, or a saturated solution of calcium chloride. Alcohol has the disadvantage in that it vaporizes readily and must be often renewed. Glycerine affects the rubber hose, while the calcium chloride solution crystallizes and deposits salt in the radiator and water pipes. One of the disadvantages of an air-cooling method, as stated by those who do not favor this system, is that engines cooled by air cannot be operated for extended periods under constant load or at very high speed without heating up to such a point that premature ignition of the charge may result. The water-cooling systems, at the other hand, maintain the temperature of the engine more nearly constant than is possible with an air-cooled motor, and an engine cooled by water can be operated under conditions of inferior lubrication or poor mixture adjustment that would seriously interfere with proper and efficient cooling by air. Air-cooled motors, as a rule, use less fuel than water-cooled engines, because the higher temperature of the cylinder does not permit of a full charge of gas being inspired on the intake stroke. As special care is needed in operating an air-cooled engine to obtain satisfactory results and because of the greater difficulty which obtains in providing proper lubrication and fuel mixtures which will not produce undue heating, the air-cooled system has but few adherents at the present time, and practically all airplanes, with but very few exceptions, are provided with water-cooled power plants. Those fitted with air-cooled engines are usually short-flight types where maximum lightness is desired in order to obtain high speed and quick climb. The water-cooled engines are best suited for airplanes intended for long flights. The Gnome, Le Rhone and Clerget engines are thoroughly practical and have been widely used in France and England. These are rotary radial cylinder types. The Anzani is a fixed cylinder engine used on training machines, while the Renault is a V-type engine made in eight- and twelve-cylinder V forms that has been used on reconnaissance and bombing airplanes with success. These types will be fully considered in proper sequence. CHAPTER VIII Methods of Cylinder Construction--Block Castings--Influence on Crank-Shaft Design--Combustion Chamber Design--Bore and Stroke Ratio--Meaning of Piston Speed--Advantage of Off-Set Cylinders-- Valve Location of Vital Import--Valve Installation Practice-- Valve Design and Construction--Valve Operation--Methods of Driving Cam-Shaft--Valve Springs--Valve Timing--Blowing Back-- Lead Given Exhaust Valve--Exhaust Closing, Inlet Opening-- Closing the Inlet Valve--Time of Ignition--How an Engine Is Timed--Gnome "Monosoupape" Valve Timing--Springless Valves--Four Valves per Cylinder. The improvements noted in the modern internal combustion motors have been due to many conditions. The continual experimenting by leading mechanical minds could have but one ultimate result. The parts of the engines have been lightened and strengthened, and greater power has been obtained without increasing piston displacement. A careful study has been made of the many conditions which make for efficient motor action, and that the main principles are well recognized by all engineers is well shown by the standardization of design noted in modern power plants. There are many different methods of applying the same principle, and it will be the purpose of this chapter to define the ways in which the construction may be changed and still achieve the same results. The various components may exist in many different forms, and all have their advantages and disadvantages. That all methods are practical is best shown by the large number of successful engines which use radically different designs. METHODS OF CYLINDER CONSTRUCTION One of the most important parts of the gasoline engine and one that has material bearing upon its efficiency is the cylinder unit. The cylinders may be cast individually, or in pairs, and it is possible to make all cylinders a unit or block casting. Some typical methods of cylinder construction are shown in accompanying illustrations. The appearance of individual cylinder castings may be ascertained by examination of the Hall-Scott airplane engine. Air-cooled engine cylinders are always of the individual pattern. Considered from a purely theoretical point of view, the individual cylinder casting has much in its favor. It is advanced that more uniform cooling is possible than where the cylinders are cast either in pairs or three or four in one casting. More uniform cooling insures that the expansion or change of form due to heating will be more equal. This is an important condition because the cylinder bore must remain true under all conditions of operation. If the heating effect is not uniform, which condition is liable to obtain if metal is not evenly distributed, the cylinder may become distorted by heat and the bore be out of truth. When separate cylinders are used it is possible to make a uniform water space and have the cooling liquid evenly distributed around the cylinder. In multiple cylinder castings this is not always the rule, as in many instances, especially in four-cylinder block motors where compactness is the main feature, there is but little space between the cylinders for the passage of water. Under such circumstances the cooling effect is not even, and the stresses which obtain because of unequal expansion may distort the cylinder to some extent. When steel cylinders are made from forgings, the water jackets are usually of copper or sheet steel attached to the forging by autogenous welding; in the case of the latter and, in some cases, the former may be electro-deposited on the cylinders. BLOCK CASTINGS [Illustration: Fig. 86.--Views of Four-Cylinder Duesenberg Airplane Engine Cylinder Block.] The advantage of casting the cylinders in blocks is that a motor may be much shorter than it would be if individual castings were used. It is admitted that when the cylinders are cast together a more compact, rigid, and stronger power plant is obtained than when cast separately. There is a disadvantage, however, in that if one cylinder becomes damaged it will be necessary to replace the entire unit, which means scrapping three good cylinders because one of the four has failed. When the cylinders are cast separately one need only replace the one that has become damaged. The casting of four cylinders in one unit is made possible by improved foundry methods, and when proper provision is made for holding the cores when the metal is poured and the cylinder casts are good, the construction is one of distinct merit. It is sometimes the case that the proportion of sound castings is less when cylinders are cast in block, but if the proper precautions are observed in molding and the proper mixtures of cast iron used, the ratio of defective castings is no more than when cylinders are molded individually. As an example of the courage of engineers in departing from old-established rules, the cylinder casting shown at Fig. 86 may be considered typical. This is used on the Duesenberg four-cylinder sixteen-valve 4-3/4" × 7" engine which has a piston displacement of 496 cu. in. At a speed of 2,000 r.p.m., corresponding to a piston speed of 2,325 ft. per min., the engine is guaranteed to develop 125 horse-power. The weight of the model engine without gear reduction is 436 lbs., but a number of refinements have been made in the design whereby it is expected to get the weight down to 390 lbs. The four cylinders are cast from semi-steel in a single block, with integral heads. The cylinder construction is the same as that which has always been used by Mr. Duesenberg, inlet and exhaust valves being arranged horizontally opposite each other in the head. There are large openings in the water jacket at both sides and at the ends, which are closed by means of aluminum covers, water-tightness being secured by the use of gaskets. This results in a saving in weight because the aluminum covers can be made considerably lighter than it would be possible to cast the jacket walls, and, besides, it permits of obtaining a more nearly uniform thickness of cylinder wall, as the cores can be much better supported. The cooling water passes completely around each cylinder, and there is a very considerable space between the two central cylinders, this being made necessary in order to get the large bearing area desirable for the central bearing. It is common practice to cast the water jackets integral with the cylinders, if cast iron or aluminum is used, and this is also the most economical method of applying it because it gives good results in practice. An important detail is that the water spaces must be proportioned so that they are equal around the cylinders whether these members are cast individually, in pairs, threes or fours. When cylinders are cast in block form it is good practice to leave a large opening in the jacket wall which will assist in supporting the core and make for uniform water space. It will be noticed that the casting shown at Fig. 86 has a large opening in the side of the cylinder block. These openings are closed after the interior of the casting is thoroughly cleaned of all sand, core wire, etc., by brass, cast iron or aluminum plates. These also have particular value in that they may be removed after the motor has been in use, thus permitting one to clean out the interior of the water jacket and dispose of the rust, sediment, and incrustation which are always present after the engine has been in active service for a time. Among the advantages claimed for the practice of casting cylinders in blocks may be mentioned compactness, lightness, rigidity, simplicity of water piping, as well as permitting the use of simple forms of inlet and exhaust manifolds. The light weight is not only due to the reduction of the cylinder mass but because the block construction permits one to lighten the entire motor. The fact that all cylinders are cast together decreases vibration, and as the construction is very rigid, disalignment of working parts is practically eliminated. When inlet and exhaust manifolds are cored in the block casting, as is sometimes the case, but one joint is needed on each of these instead of the multiplicity of joints which obtain when the cylinders are individual castings. The water piping is also simplified. In the case of a four-cylinder block motor but two pipes are used; one for the water to enter the cylinder jacket, the other for the cooling liquid to discharge through. INFLUENCE ON CRANK-SHAFT DESIGN [Illustration: Fig. 87.--Twin-Cylinder Block of Sturtevant Airplane Engine is Cast of Aluminum, and Has Removable Cylinder Head.] The method of casting the cylinders has a material influence on the design of the crank-shaft as will be shown in proper sequence. When four cylinders are combined in one block it is possible to use a two-bearing crank-shaft. Where cylinders are cast in pairs a three-bearing crank-shaft is commonly supplied, and when cylinders are cast as individual units it is thought necessary to supply a five-bearing crank-shaft, though sometimes shafts having but three journals are used successfully. Obviously the shafts must be stronger and stiffer to withstand the stresses imposed if two supporting bearings are used than if a larger number are employed. In this connection it may be stated that there is less difficulty in securing alignment with a lesser number of bearings and there is also less friction. On the other hand, the greater the number of points of support a crank-shaft has the lighter the webs can be made and still have requisite strength. COMBUSTION CHAMBER DESIGN [Illustration: Fig. 88.--Aluminum Cylinder Pair Casting of Thomas 150 Horse-Power Airplane Engine is of the L Head Type.] Another point of importance in the design of the cylinder, and one which has considerable influence upon the power developed, is the shape of the combustion chamber. The endeavor of designers is to obtain maximum power from a cylinder of certain proportions, and the greater energy obtained without increasing piston displacement or fuel consumption the higher the efficiency of the motor. To prevent troubles due to pre-ignition it is necessary that the combustion chamber be made so that there will be no roughness, sharp corners, or edges of metal which may remain incandescent when heated or which will serve to collect carbon deposits by providing a point of anchorage. With the object of providing an absolutely clean combustion chamber some makers use a separable head unit to their twin cylinder castings, such as shown at Fig. 87 and Fig. 88. These permit one to machine the entire interior of the cylinder and combustion chamber. The relation of valve location and combustion chamber design will be considered in proper sequence. These cylinders are cast of aluminum, instead of cast iron, as is customary, and are provided with steel or cast iron cylinder liners forced in the soft metal casting bores. BORE AND STROKE RATIO A question that has been a vexed one and which has been the subject of considerable controversy is the proper proportion of the bore to the stroke. The early gas engines had a certain well-defined bore to stroke ratio, as it was usual at that time to make the stroke twice as long as the bore was wide, but this cannot be done when high speed is desired. With the development of the present-day motor the stroke or piston travel has been gradually shortened so that the relative proportions of bore and stroke have become nearly equal. Of late there seems to be a tendency among designers to return to the proportions which formerly obtained, and the stroke is sometimes one and a half or one and three-quarter times the bore. Engines designed for high speed should have the stroke not much longer than the diameter of the bore. The disadvantage of short-stroke engines is that they will not pull well at low speeds, though they run with great regularity and smoothness at high velocity. The long-stroke engine is much superior for slow speed work, and it will pull steadily and with increasing power at low speed. It was formerly thought that such engines should never turn more than a moderate number of revolutions, in order not to exceed the safe piston speed of 1,000 feet per minute. This old theory or rule of practice has been discarded in designing high efficiency automobile racing and aviation engines, and piston speeds from 2,500 to 3,000 feet per minute are sometimes used, though the average is around 2,000 feet per minute. While both short- and long-stroke motors have their advantages, it would seem desirable to average between the two. That is why a proportion of four to five or six seems to be more general than that of four to seven or eight, which would be a long-stroke ratio. Careful analysis of a number of foreign aviation motors shows that the average stroke is about 1.2 times the bore dimensions, though some instances were noted where it was as high as 1.7 times the bore. MEANING OF PISTON SPEED The factor which limits the stroke and makes the speed of rotation so dependent upon the travel of the piston is piston speed. Lubrication is the main factor which determines piston speed, and the higher the rate of piston travel the greater care must be taken to insure proper oiling. Let us fully consider what is meant by piston speed. Assume that a motor has a piston travel or stroke of six inches, for the sake of illustration. It would take two strokes of the piston to cover one foot, or twelve inches, and as there are two strokes to a revolution it will be seen that this permits of a normal speed of 1,000 revolutions per minute for an engine with a six-inch stroke, if one does not exceed 1,000 feet per minute. If the stroke was only four inches, a normal speed of 1,500 revolutions per minute would be possible without exceeding the prescribed limit. The crank-shaft of a small engine, having three-inch stroke, could turn at a speed of 2,000 revolutions per minute without danger of exceeding the safe speed limit. It will be seen that the longer the stroke the slower the speed of the engine, if one desires to keep the piston speed within the bounds as recommended, but modern practice allows of greatly exceeding the speeds formerly thought best. ADVANTAGES OF OFF-SET CYLINDERS [Illustration: Fig. 90.--Cross Section of Austro-Daimler Engine, Showing Offset Cylinder Construction. Note Applied Water Jacket and Peculiar Valve Action.] Another point upon which considerable difference of opinion exists relates to the method of placing the cylinder upon the crank-case--i.e., whether its center line should be placed directly over the center of the crank-shaft, or to one side of center. The motor shown at Fig. 90 is an off-set type, in that the center line of the cylinder is a little to one side of the center of the crank-shaft. Diagrams are presented at Fig. 91 which show the advantages of off-set crank-shaft construction. The view at A is a section through a simple motor with the conventional cylinder placing, the center line of both crank-shaft and cylinder coinciding. The view at B shows the cylinder placed to one side of center so that its center line is distinct from that of the crank-shaft and at some distance from it. The amount of off-set allowed is a point of contention, the usual amount being from fifteen to twenty-five per cent. of the stroke. The advantages of the off-set are shown at Fig. 91, C. If the crank turns in direction of the arrow there is a certain resistance to motion which is proportional to the amount of energy exerted by the engine and the resistance offered by the load. There are two thrusts acting against the cylinder wall to be considered, that due to explosion or expansion of the gas, and that which resists the motion of the piston. These thrusts may be represented by arrows, one which acts directly in a vertical direction on the piston top, the other along a straight line through the center of the connecting rod. Between these two thrusts one can draw a line representing a resultant force which serves to bring the piston in forcible contact with one side of the cylinder wall, this being known as side thrust. As shown at C, the crank-shaft is at 90 degrees, or about one-half stroke, and the connecting rod is at 20 degrees angle. The shorter connecting rod would increase the diagonal resultant and side thrusts, while a longer one would reduce the angle of the connecting rod and the side thrust of the piston would be less. With the off-set construction, as shown at D, it will be noticed that with the same connecting-rod length as shown at C and with the crank-shaft at 90 degrees of the circle that the connecting-rod angle is 14 degrees and the side thrust is reduced proportionately. [Illustration: Fig. 91.--Diagrams Demonstrating Advantages of Offset Crank-Shaft Construction.] Another important advantage is that greater efficiency is obtained from the explosion with an off-set crank-shaft, because the crank is already inclined when the piston is at top center, and all the energy imparted to the piston by the burning mixture can be exerted directly into producing a useful turning effort. When a cylinder is placed directly on a line with the crank-shaft, as shown at A, it will be evident that some of the force produced by the expansion of the gas will be exerted in a direct line and until the crank moves the crank throw and connecting rod are practically a solid member. The pressure which might be employed in obtaining useful turning effort is wasted by causing a direct pressure upon the lower half of the main bearing and the upper half of the crank-pin bushing. Very good and easily understood illustrations showing advantages of the off-set construction are shown at E and F. This is a bicycle crank-hanger. It is advanced that the effort of the rider is not as well applied when the crank is at position E as when it is at position F. Position E corresponds to the position of the parts when the cylinder is placed directly over the crank-shaft center. Position F may be compared to the condition which is present when the off-set cylinder construction is used. VALVE LOCATION OF VITAL IMPORT It has often been said that a chain is no stronger than its weakest link, and this is as true of the explosive motor as it is of any other piece of mechanism. Many motors which appeared to be excellently designed and which were well constructed did not prove satisfactory because some minor detail or part had not been properly considered by the designer. A factor having material bearing upon the efficiency of the internal combustion motor is the location of the valves and the shape of the combustion chamber which is largely influenced by their placing. The fundamental consideration of valve design is that the gases be admitted and discharged from the cylinder as quickly as possible in order that the speed of gas flow will not be impeded and produce back pressure. This is imperative in obtaining satisfactory operation in any form of motor. If the inlet passages are constricted the cylinder will not fill with explosive mixture promptly, whereas if the exhaust gases are not fully expelled the parts of the inert products of combustion retained dilute the fresh charge, making it slow burning and causing lost power and overheating. When an engine employs water as a cooling medium this substance will absorb the surplus heat readily, and the effects of overheating are not noticed as quickly as when air-cooled cylinders are employed. Valve sizes have a decided bearing upon the speed of motors and some valve locations permit the use of larger members than do other positions. While piston velocity is an important factor in determinations of power output, it must be considered from the aspect of the wear produced upon the various parts of the motor. It is evident that engines which run very fast, especially of high power, must be under a greater strain than those operating at lower speeds. The valve-operating mechanism is especially susceptible to the influence of rapid movement, and the slower the engine the longer the parts will wear and the more reliable the valve action. [Illustration: Fig. 92.--Diagram Showing Forms of Cylinder Demanded by Different Valve Placings. A--T Head Type, Valves on Opposite Sides. B--L Head Cylinder, Valves Side by Side. C--L Head Cylinder, One Valve in Head, Other in Pocket. D--Inlet Valve Over Exhaust Member, Both in Side Pocket. E--Valve-in-the-Head Type with Vertical Valves. F--Inclined Valves Placed to Open Directly into Combustion Chamber.] As will be seen by reference to the accompanying illustration, Fig. 92, there are many ways in which valves may be placed in the cylinder. Each method outlined possesses some point of advantage, because all of the types illustrated are used by reputable automobile manufacturers. The method outlined at Fig. 92, A, is widely used, and because of its shape the cylinder is known as the "T" form. It is approved for automobile use for several reasons, the most important being that large valves can be employed and a well-balanced and symmetrical cylinder casting obtained. Two independent cam-shafts are needed, one operating the inlet valves, the other the exhaust members. The valve-operating mechanism can be very simple in form, consisting of a plunger actuated by the cam which transmits the cam motion to the valve-stem, raising the valve as the cam follower rides on the point of the cam. Piping may be placed without crowding, and larger manifolds can be fitted than in some other constructions. This has special value, as it permits the use of an adequate discharge pipe on the exhaust side with its obvious advantages. This method of cylinder construction is never found on airplane engines because it does not permit of maximum power output. On the other hand, if considered from a viewpoint of actual heat efficiency, it is theoretically the worst form of combustion chamber. This disadvantage is probably compensated for by uniformity of expansion of the cylinder because of balanced design. The ignition spark-plug may be located directly over the inlet valve in the path of the incoming fresh gases, and both valves may be easily removed and inspected by unscrewing the valve caps without taking off the manifolds. The valve installation shown at C is somewhat unusual, though it provides for the use of valves of large diameter. Easy charging is insured because of the large inlet valve directly in the top of the cylinder. Conditions may be reversed if necessary, and the gases discharged through this large valve. Both methods are used, though it would seem that the free exhaust provided by allowing the gases to escape directly from the combustion chamber through the overhead valve to the exhaust manifold would make for more power. The method outlined at Fig. 92, F and at Fig. 90 is one that has been widely employed on large automobile racing motors where extreme power is required, as well as in engines constructed for aviation service. The inclination of the valves permits the use of large valves, and these open directly into the combustion chamber. There are no pockets to retain heat or dead gas, and free intake and outlet of gas is obtained. This form is quite satisfactory from a theoretical point of view because of the almost ideal combustion chamber form. Some difficulty is experienced, however, in properly water-jacketing the valve chamber which experience has shown to be necessary if the engine is to have high power. The motor shown at Fig. 92, B and Fig. 88 employs cylinders of the "L" type. Both valves are placed in a common extension from the combustion chamber, and being located side by side both are actuated from a common cam-shaft. The inlet and exhaust pipes may be placed on the same side of the engine and a very compact assemblage is obtained, though this is optional if passages are cored in the cylinder pairs to lead the gases to opposite sides. The valves may be easily removed if desired, and the construction is fairly good from the viewpoint of both foundry man and machinist. The chief disadvantage is the limited area of the valves and the loss of heat efficiency due to the pocket. This form of combustion chamber, however, is more efficient than the "T" head construction, though with the latter the use of larger valves probably compensates for the greater heat loss. It has been stated as an advantage of this construction that both manifolds can be placed at the same side of the engine and a compact assembly secured. On the other hand, the disadvantage may be cited that in order to put both pipes on the same side they must be of smaller size than can be used when the valves are oppositely placed. The "L" form cylinder is sometimes made more efficient if but one valve is placed in the pocket while the other is placed over it. This construction is well shown at Fig. 92, D and is found on Anzani motors. [Illustration: Fig. 93.--Sectional View of Engine Cylinder Showing Valve and Cage Installation.] The method of valve application shown at Fig. 87 is an ingenious method of overcoming some of the disadvantages inherent with valve-in-the-head motors. In the first place it is possible to water-jacket the valves thoroughly, which is difficult to accomplish when they are mounted in cages. The water circulates directly around the walls of the valve chambers, which is superior to a construction where separate cages are used, as there are two thicknesses of metal with the latter, that of the valve-cage proper and the wall of the cylinder. The cooling medium is in contact only with the outer wall, and as there is always a loss of heat conductivity at a joint it is practically impossible to keep the exhaust valves and their seats at a uniform temperature. The valves may be of larger size without the use of pockets when seating directly in the head. In fact, they could be equal in diameter to almost half the bore of the cylinder, which provides an ideal condition of charge placement and exhaust. When valve grinding is necessary the entire head is easily removed by taking off six nuts and loosening inlet manifold connections, which operation would be necessary even if cages were employed, as in the engine shown at Fig. 93. [Illustration: Fig. 94.--Diagrams Showing How Gas Enters Cylinder Through Overhead Valves and Other Types. A--Tee Head Cylinder. B--L Head Cylinder. C--Overhead Valve.] [Illustration: Fig. 95.--Conventional Methods of Operating Internal Combustion Motor Valves.] At Fig. 94, A and B, a section through a typical "L"-shaped cylinder is depicted. It will be evident that where a pocket construction is employed, in addition to its faculty for absorbing heat, the passage of gas would be impeded. For example, the inlet gas rushing in through the open valve would impinge sharply upon the valve-cap or combustion head directly over the valve and then must turn at a sharp angle to enter the combustion chamber and then at another sharp angle to fill the cylinders. The same conditions apply to the exhaust gases, though they are reversed. When the valve-in-the-head type of cylinder is employed, as at C, the only resistance offered the gas is in the manifold. As far as the passage of the gases in and out of the cylinder is concerned, ideal conditions obtain. It is claimed that valve-in-the-head motors are more flexible and responsive than other forms, but the construction has the disadvantage in that the valves must be opened through a rather complicated system of push rods and rocker arms instead of the simpler and direct plunger which can be used with either the "T" or "L" head cylinders. This is clearly outlined in the illustrations at Fig. 95, where A shows the valve in the head-operating mechanism necessary if the cam-shaft is carried at the cylinder base, while B shows the most direct push-rod action obtained with "T" or "L" head cylinder placing. [Illustration: Fig. 96.--Examples of Direct Valve Actuation by Overhead Cam-Shaft. A--Mercedes. B--Hall-Scott. C--Wisconsin.] [Illustration: Fig. 97. CENSORED] [Illustration: Fig. 98. CENSORED] The objection can be easily met by carrying the cam-shaft above the cylinders and driving it by means of gearing. The types of engine cylinders using this construction are shown at Fig. 96, and it will be evident that a positive and direct valve action is possible by following the construction originated by the Mercedes (German) aviation engine designers and outlined at A. The other forms at B and C are very clearly adaptations of this design. The Hall-Scott engine at Fig. 97 is depicted in part section and no trouble will be experienced in understanding the bevel pinion and gear drive from the crank-shaft to the overhead cam-shaft through a vertical counter-shaft. A very direct valve action is used in the Duesenberg engines, one of which is shown in part section at Fig. 98. The valves are parallel with the piston top and are actuated by rocker arms, one end of which bears against the valve stem, and the other rides the cam-shaft. [Illustration: Fig. 99.--Sectional Views Showing Arrangement of Novel Concentric Valve Arrangement Devised by Panhard for Aerial Engines.] The form shown at Fig. 99 shows an ingenious application of the valve-in-the-head idea which permits one to obtain large valves. It has been used on some of the Panhard aviation engines and on the American Aeromarine power plants. The inlet passage is controlled by the sliding sleeve which is hollow and slotted so as to permit the inlet gases to enter the cylinder through the regular type poppet valve which seats in the exhaust sleeve. When the exhaust valve is operated by the tappet rod and rocker arm the intake valve is also carried down with it. The intake gas passage is closed, however, and the burned gases are discharged through the large annular passage surrounding the sleeve. When the inlet valve leaves its seat in the sleeve the passage of cool gas around the sleeve keeps the temperature of both valves to a low point and the danger of warping is minimized. A dome-shaped combustion chamber may be used, which is an ideal form in conserving heat efficiency, and as large valves may be installed the flow of both fresh and exhaust gases may be obtained with minimum resistance. The intake valve is opened by a small auxiliary rocker arm which is lifted when the cam follower rides into the depression in the cam by the action of the strong spring around the push rod. When the cam follower rides on the high point the exhaust sleeve is depressed from its seat against the cylinder. By using a cam having both positive and negative profiles, a single rod suffices for both valves because of its push and pull action. VALVE DESIGN AND CONSTRUCTION Valve dimensions are an important detail to be considered and can be determined by several conditions, among which may be cited method of installation, operating mechanism, material employed, engine speed desired, manner of cylinder cooling and degree of lift desired. A review of various methods of valve location has shown that when the valves are placed directly in the head we can obtain the ideal cylinder form, though larger valves may be used if housed in a separate pocket, as afforded by the "T" head construction. The method of operation has much to do with the size of the valves. For example, if an automatic inlet valve is employed it is good practice to limit the lift and obtain the required area of port opening by augmenting the diameter. Because of this a valve of the automatic type is usually made twenty per cent. larger than one mechanically operated. When both are actuated by cam mechanism, as is now common practice, they are usually made the same size and are interchangeable, which greatly simplifies manufacture. The relation of valve diameter to cylinder bore is one that has been discussed for some time by engineers. The writer's experience would indicate that they should be at least half the bore, if possible. While the mushroom type or poppet valve has become standard and is the most widely used form at the present time, there is some difference of opinion among designers as to the materials employed and the angle of the seat. Most valves have a bevel seat, though some have a flat seating. The flat seat valve has the distinctive advantage of providing a clear opening with lesser lift, this conducing to free gas flow. It also has value because it is silent in operation, but the disadvantage is present that best material and workmanship must be used in their construction to obtain satisfactory results. As it can be made very light it is particularly well adapted for use as an automatic inlet valve. Among other disadvantages cited is the claim that it is more susceptible to derangement, owing to the particles of foreign matter getting under the seat. With a bevel seat it is argued that the foreign matter would be more easily dislodged by the gas flow, and that the valve would close tighter because it is drawn positively against the bevel seat. Several methods of valve construction are the vogue, the most popular form being the one-piece type; those which are composed of a head of one material and stem of another are seldom used in airplane engines because they are not reliable. In the built-up construction the head is usually of high nickel steel or cast iron, which metals possess good heat-resisting qualities. Heads made of these materials are not likely to warp, scale, or pit, as is sometimes the case when ordinary grades of machinery steel are used. The cast-iron head construction is not popular because it is often difficult to keep the head tight on the stem. There is a slight difference in expansion ratio between the head and the stem, and as the stem is either screwed or riveted to the cast-iron head the constant hammering of the valve against its seat may loosen the joint. As soon as the head is loose on the stem the action of the valve becomes erratic. The best practice is to machine the valves from tungsten steel forgings. This material has splendid heat-resisting qualities and will not pit or become scored easily. Even the electrically welded head to stem types which are used in automobile engines are not looked upon with favor in the aviation engine. Valve stem guides and valve stems must be machined very accurately to insure correct action. The usual practice in automobile engines is shown at Fig. 100. [Illustration: Fig. 100.--Showing Clearance Allowed Between Valve Stem and Valve Stem Guide to Secure Free Action.] VALVE OPERATION The methods of valve operation commonly used vary according to the type of cylinder construction employed. In all cases the valves are lifted from their seats by cam-actuated mechanism. Various forms of valve-lifting cams are shown at Fig. 101. As will be seen, a cam consists of a circle to which a raised, approximately triangular member has been added at one point. When the cam follower rides on the circle, as shown at Fig. 102, there is no difference in height between the cam center and its periphery and there is no movement of the plunger. As soon as the raised portion of the cam strikes the plunger it will lift it, and this reciprocating movement is transmitted to the valve stem by suitable mechanical connections. [Illustration: Fig. 101.--Forms of Valve-Lifting Cams Generally Employed. A--Cam Profile for Long Dwell and Quick Lift. B--Typical Inlet Cam Used with Mushroom Type Follower. C--Average Form of Cam. D--Designed to Give Quick Lift and Gradual Closing.] The cam forms outlined at Fig. 101 are those commonly used. That at A is used on engines where it is desired to obtain a quick lift and to keep the valve fully opened as long as possible. It is a noisy form, however, and is not very widely employed. That at B is utilized more often as an inlet cam while the profile shown at C is generally depended on to operate exhaust valves. The cam shown at D is a composite form which has some of the features of the other three types. It will give the quick opening of form A, the gradual closing of form B, and the time of maximum valve opening provided by cam profile C. [Illustration: Fig. 102.--Showing Principal Types of Cam Followers which Have Received General Application.] The various types of valve plungers used are shown at Fig. 102. That shown at A is the simplest form, consisting of a simple cylindrical member having a rounded end which follows the cam profile. These are sometimes made of square stock or kept from rotating by means of a key or pin. A line contact is possible when the plunger is kept from turning, whereas but a single point bearing is obtained when the plunger is cylindrical and free to revolve. The plunger shown at A will follow only cam profiles which have gradual lifts. The plunger shown at B is left free to revolve in the guide bushing and is provided with a flat mushroom head which serves as a cam follower. The type shown at C carries a roller at its lower end and may follow very irregular cam profiles if abrupt lifts are desired. While forms A and B are the simplest, that outlined at C in its various forms is more widely used. Compound plungers are used on the Curtiss OX-2 motors, one inside the other. The small or inner one works on a cam of conventional design, the outer plunger follows a profile having a flat spot to permit of a pull rod action instead of a push rod action. All the methods in which levers are used to operate valves are more or less noisy because clearance must be left between the valve stem and the stop of the plunger. The space must be taken up before the valve will leave its seat, and when the engine is operated at high speeds the forcible contact between the plunger and valve stem produces a rattling sound until the valves become heated and expand and the stems lengthen out. Clearance must be left between the valve stems and actuating means. This clearance is clearly shown in Fig. 103 and should be .020" (twenty thousandths) when engine is cold. The amount of clearance allowed depends entirely upon the design of the engine and length of valve stem. On the Curtiss OX-2 engines the clearance is but .010" (ten thousandths) because the valve stems are shorter. Too little clearance will result in loss of power or misfiring when engine is hot. Too much clearance will not allow the valve to open its full amount and will disturb the timing. [Illustration: Fig. 103.--Diagram Showing Proper Clearance to Allow Between Adjusting Screw and Valve Stems in Hall-Scott Aviation Engines.] METHODS OF DRIVING CAM-SHAFT Two systems of cam-shaft operation are used. The most common of these is by means of gearing of some form. If the cam-shaft is at right angles to the crank-shaft it may be driven by worm, spiral, or bevel gearing. If the cam-shaft is parallel to the crank-shaft, simple spur gear or chain connection may be used to turn it. A typical cam-shaft for an eight-cylinder V engine is shown at Fig. 104. It will be seen that the sixteen cams are forged integrally with the shaft and that it is spur-gear driven. The cam-shaft drive of the Hall-Scott motor is shown at Fig. 97. [Illustration: Fig. 104.--Cam-Shaft of Thomas Airplane Motor Has Cams Forged Integral. Note Split Cam-Shaft Bearings and Method of Gear Retention.] While gearing is more commonly used, considerable attention has been directed of late to silent chains for cam-shaft operation. The ordinary forms of block or roller chain have not proven successful in this application, but the silent chain, which is in reality a link belt operating over toothed pulleys, has demonstrated its worth. The tendency to its use is more noted on foreign motors than those of American design. It first came to public notice when employed on the Daimler-Knight engine for driving the small auxiliary crank-shafts which reciprocated the sleeve valves. The advantages cited for the application of chains are, first, silent operation, which obtains even after the chains have worn considerably; second, in designing it is not necessary to figure on maintaining certain absolute center distances between the crank-shaft and cam-shaft sprockets, as would be the case if conventional forms of gearing were used. On some forms of motor employing gears, three and even four members are needed to turn the cam-shaft. With a chain drive but two sprockets are necessary, the chain forming a flexible connection which permits the driving and driven members to be placed at any distance apart that the exigencies of the design demand. When chains are used it is advised that some means for compensating chain slack be provided, or the valve timing will lag when chains are worn. Many combination drives may be worked out with chains that would not be possible with other forms of gearing. Direct gear drive is favored at the present time by airplane engine designers because they are the most certain and positive means, even when a number of gears must be used as intermediate drive members. With overhead cam-shafts, bevel gears work out very well in practice, as in the Hall-Scott motors and others of that type. VALVE SPRINGS [Illustration: Fig. 105.--Section Through Cylinder of Knight Motor, Showing Important Parts of Valve Motion.] Another consideration of importance is the use of proper valve-springs, and particular care should be taken with those, of automatic valves. The spring must be weak enough to allow the valve to open when the suction is light, and must be of sufficient strength to close it in time at high speeds. It should be made as large as possible in diameter and with a large number of convolutions, in order that fatigue of the metal be obviated, and it is imperative that all springs be of the same strength when used on a multiple-cylinder engine. Practically all valves used to control the gas flow in airplane engines are mechanically operated. On the exhaust valve the spring must be strong enough so that the valve will not be sucked in on the inlet stroke. It should be borne in mind that if the spring is too strong a strain will be imposed on the valve-operating mechanism, and a hammering action produced which may cause deformation of the valve-seat. Only pressure enough to insure that the operating mechanism will follow the cam is required. It is common practice to make the inlet and exhaust valve springs of the same tension when the valves are of the same size and both mechanically operated. This is done merely to simplify manufacture and not because it is necessary for the inlet valve-spring to be as strong as the other. Valve springs of the helical coil type are generally used, though torsion or "scissors" springs and laminated or single-leaf springs are also utilized in special applications. Two springs are used on each valve in some valve-in-the-head types; a spring of small pitch diameter inside the regular valve-spring and concentric with it. Its function is to keep the valve from falling into the cylinder in event of breakage of the main spring in some cases, and to provide a stronger return action in others. [Illustration: Fig. 106.--Diagrams Showing Knight Sleeve Valve Action.] KNIGHT SLIDE VALVE MOTOR The sectional view through the cylinder at Fig. 105 shows the Knight sliding sleeves and their actuating means very clearly. The diagrams at Fig. 106 show graphically the sleeve movements and their relation to the crank-shaft and piston travel. The action may be summed up as follows: The inlet port begins to open when the lower edge of the opening of the outside sleeve which is moving down passes the top of the slot in the inner member also moving downwardly. The inlet port is closed when the lower edge of the slot in the inner sleeve which is moving up passes the top edge of the port in the outer sleeve which is also moving toward the top of the cylinder. The inlet opening extends over two hundred degrees of crank motion. The exhaust port is uncovered slightly when the lower edge of the port in the inner sleeve which is moving down passes the lower edge of the portion of the cylinder head which protrudes in the cylinder. When the top of the port in the outer sleeve traveling toward the bottom of the cylinder passes the lower edge of the slot in the cylinder wall the exhaust passage is closed. The exhaust opening extends over a period corresponding to about two hundred and forty degrees of crank motion. The Knight motor has not been applied to aircraft to the writer's knowledge, but an eight-cylinder Vee design that might be useful in that connection if lightened is shown at Fig. 107. The main object is to show that the Knight valve action is the only other besides the mushroom or poppet valve that has been applied successfully to high speed gasoline engines. VALVE TIMING It is in valve timing that the greatest difference of opinion prevails among engineers, and it is rare that one will see the same formula in different motors. It is true that the same timing could not be used with motors of different construction, as there are many factors which determine the amount of lead to be given to the valves. The most important of these is the relative size of the valve to the cylinder bore, the speed of rotation it is desired to obtain, the fuel efficiency, the location of the valves, and other factors too numerous to mention. [Illustration: Fig. 107.--Cross Sectional View of Knight Type Eight Cylinder V Engine.] Most of the readers should be familiar with the cycle of operation of the internal combustion motor of the four-stroke type, and it seems unnecessary to go into detail except to present a review. The first stroke of the piston is one in which a charge of gas is taken into the motor; the second stroke, which is in reverse direction to the first, is a compression stroke, at the end of which the spark takes place, exploding the charge and driving the piston down on the third or expansion stroke, which is in the same direction as the intake stroke, and finally, after the piston has nearly reached the end of this stroke, another valve opens to allow the burned gases to escape, and remains open until the piston has reached the end of the fourth stroke and is in a position to begin the series over again. The ends of the strokes are reached when the piston comes to a stop at either top or bottom of the cylinder and reverses its motion. That point is known as a center, and there are two for each cylinder, top and bottom centers, respectively. All circles may be divided into 360 parts, each of which is known as a degree, and, in turn, each of these degrees may be again divided into minutes and seconds, though we need not concern ourselves with anything less than the degree. Each stroke of the piston represents 180 degrees travel of the crank, because two strokes represent one complete revolution of three hundred and sixty degrees. The top and bottom centers are therefore separated by 180 degrees. Theoretically each phase of a four-cycle engine begins and ends at a center, though in actual practice the inertia or movement of the gases makes it necessary to allow a lead or lag to the valve, as the case may be. If a valve opens before a center, the distance is called "lead"; if it closes after a center, this distance is known as "lag." The profile of the cams ordinarily used to open or close the valves represents a considerable time in relation to the 180 degrees of the crank-shaft travel, and the area of the passages through which the gases are admitted or exhausted is quite small owing to the necessity of having to open or close the valves at stated times; therefore, to open an adequately large passage for the gases it is necessary to open the valves earlier and close them later than at centers. That advancing the opening of the exhaust valve was of value was discovered on the early motors and is explained by the necessity of releasing a large amount of gas, the volume of which has been greatly raised by the heat of combustion. When the inlet valves were mechanically operated it was found that allowing them to lag at closing enabled the inspiration of a greater volume of gas. Disregarding the inertia or flow of the gases, opening the exhaust at center would enable one to obtain full value of the expanding gases the entire length of the piston stroke, and it would not be necessary to keep the valve open after the top center, as the reverse stroke would produce a suction effect which might draw some of the inert charge back into the cylinder. On the other hand, giving full consideration to the inertia of the gas, opening the valve before center is reached will provide for quick expulsion of the gases, which have sufficient velocity at the end of the stroke, so that if the valve is allowed to remain open a little longer, the amount of lag varying with the opinions of the designer, the cylinder is cleared in a more thorough manner. BLOWING BACK When the factor of retarded opening is considered without reckoning the inertia of the gases, it would appear that if the valve were allowed to remain open after center had passed, say, on the closing of the inlet, the piston, having reversed its motion, would have the effect of expelling part of the fresh charge through the still open valve as it passed inward at its compression stroke. This effect is called blowing back, and is often noted with motors where the valve settings are not absolutely correct, or where the valve-springs or seats are defective and prevent proper closing. This factor is not of as much import as might appear, as on closer consideration it will be seen that the movement of the piston as the crank reaches either end of the stroke is less per degree of angular movement than it is when the angle of the connecting rod is greater. Then, again, a certain length of time is required for the reversal of motion of the piston, during which time the crank is in motion but the piston practically at a standstill. If the valves are allowed to remain open during this period, the passage of the gas in or out of the cylinder will be by its own momentum. LEAD GIVEN EXHAUST VALVE The faster a motor turns, all other things being equal, the greater the amount of lead or advance it is necessary to give the opening of the exhaust valve. It is self-evident truth that if the speed of a motor is doubled it travels twice as many degrees in the time necessary to lower the pressure. As most designers are cognizant of this fact, the valves are proportioned accordingly. It is well to consider in this respect that the cam profile has much to do with the manner in which the valve is opened; that is, the lift may be abrupt and the gas allowed to escape in a body, or the opening may be gradual, the gas issuing from the cylinder in thin streams. An analogy may be made with the opening of any bottle which contains liquid highly carbonated. If the cork is removed suddenly the gas escapes with a loud pop, but, on the other hand, if the bottle is uncorked gradually, the gas escapes from the receptacle in thin streams around the cork, and passage of the gases to the air is accomplished without noise. While the second plan is not harsh, it is slower than the former, as must be evident. EXHAUST CLOSING, INLET OPENING A point which has been much discussed by engineers is the proper relation of the closing of the exhaust valve and the opening of the inlet. Theoretically they should succeed each other, the exhaust closing at upper dead center and the inlet opening immediately afterward. The reason why a certain amount of lag is given the exhaust closing in practice is that the piston cannot drive the gases out of the cylinder unless they are compressed to a degree in excess of that existing in the manifold or passages, and while toward the end of the stroke this pressure may be feeble, it is nevertheless indispensable. At the end of the piston's stroke, as marked by the upper dead center, this compression still exists, no matter how little it may be, so that if the exhaust valve is closed and the inlet opened immediately afterward, the pressure which exists in the cylinder may retard the entrance of the fresh gas and a certain portion of the inert gas may penetrate into the manifold. As the piston immediately begins to aspirate, this may not be serious, but as these gases are drawn back into the cylinder the fresh charge will be diluted and weakened in value. If the spark-plug is in a pocket, the points may be surrounded by this weak gas, and the explosion will not be nearly as energetic as when the ignition spark takes place in pure mixture. It is a well-known fact that the exhaust valve should close after dead center and that a certain amount of lag should be given to opening of the inlet. The lag given the closing of the exhaust valve should not be as great as that given the closing of the inlet valve. Assuming that the excess pressure of the exhaust will equal the depression during aspiration, the time necessary to complete the emptying of the cylinder will be proportional to the volume of the gas within it. At the end of the suction stroke the volume of gas contained in the cylinder is equal to the cylindrical volume plus the space of the combustion chamber. At the end of the exhaust stroke the volume is but that of the dead space, and from one-third to one-fifth its volume before compression. While it is natural to assume that this excess of burned gas will escape faster than the fresh gas will enter the cylinder, it will be seen that if the inlet valve were allowed to lag twenty degrees, the exhaust valve lag need not be more than five degrees, providing that the capacity of the combustion chamber was such that the gases occupied one-quarter of their former volume. It is evident that no absolute rule can be given, as back pressure will vary with the design of the valve passages, the manifolds, and the construction of the muffler. The more direct the opening, the sooner the valve can be closed and the better the cylinder cleared. Ten degrees represent an appreciable angle of the crank, and the time required for the crank to cover this angular motion is not inconsiderable and an important quantity of the exhaust may escape, but the piston is very close to the dead center after the distance has been covered. Before the inlet valve opens there should be a certain depression in the cylinder, and considerable lag may be allowed before the depression is appreciable. So far as the volume of fresh gas introduced during the admission stroke is concerned, this is determined by the displacement of the piston between the point where the inlet valve opens and the point of closing, assuming that sufficient gas has been inspired so that an equilibrium of pressure has been established between the interior of the cylinder and the outer air. The point of inlet opening varies with different motors. It would appear that a fair amount of lag would be fifteen degrees past top center for the inlet opening, as a certain depression will exist in the cylinder, assuming that the exhaust valve has closed five or ten degrees after center, and at the same time the piston has not gone down far enough on its stroke to materially decrease the amount of gas which will be taken into the cylinder. CLOSING THE INLET VALVE As in the case with the other points of opening and closing, there is a wide diversity of practice as relates to closing the inlet valve. Some of the designers close this exactly at bottom center, but this practice cannot be commended, as there is a considerable portion of time, at least ten or fifteen degrees angular motion of the crank, before the piston will commence to travel to any extent on its compression stroke. The gases rushing into the cylinder have considerable velocity, and unless an equilibrium is obtained between the pressure inside and that of the atmosphere outside, they will continue to rush into the cylinder even after the piston ceases to exert any suction effect. For this reason, if the valve is closed exactly on center, a full charge may not be inspired into the cylinder, though if the time of closing is delayed, this momentum or inertia of the gas will be enough to insure that a maximum charge is taken into the cylinder. The writer considers that nothing will be gained if the valve is allowed to remain open longer than twenty degrees, and an analysis of practice in this respect would seem to confirm this opinion. From that point in the crank movement the piston travel increases and the compressive effect is appreciable, and it would appear that a considerable proportion of the charge might be exhausted into the manifold and carburetor if the valve were allowed to remain open beyond a point corresponding to twenty degrees angular movement of the crank. TIME OF IGNITION In this country engineers unite in providing a variable time of ignition, though abroad some difference of opinion is noted on this point. The practice of advancing the time of ignition, when affected electrically, was severely condemned by early makers, these maintaining that it was necessary because of insufficient heat and volume of the spark, and it was thought that advancing ignition was injurious. The engineers of to-day appreciate the fact that the heat of the electric spark, especially when from a mechanical generator of electrical energy, is the only means by which we can obtain practically instantaneous explosion, as required by the operation of motors at high speeds, and for the combustion of large volumes of gas. [Illustration: Fig. 108.--Diagrams Explaining Valve and Ignition Timing of Hall-Scott Aviation Engine.] It is apparent that a motor with a fixed point of ignition is not as desirable, in every way, as one in which the ignition can be advanced to best meet different requirements, and the writer does not readily perceive any advantage outside of simplicity of control in establishing a fixed point of ignition. In fact, there seems to be some difference of opinion among those designers who favor fixed ignition, and in one case this is located forty-three degrees ahead of center, and in another motor the point is fixed at twenty degrees, so that it may be said that this will vary as much as one hundred per cent. in various forms. This point will vary with different methods of ignition, as well as the location of the spark-plug or igniter. For the sake of simplicity, most airplane engines use set spark; if an advancing and retarding mechanism is fitted, it is only to facilitate starting, as the spark is kept advanced while in flight, and control is by throttle alone. [Illustration: Fig. 109.--Timing Diagram of Typical Six-Cylinder Engine.] It is obvious by consideration of the foregoing that there can be no arbitrary rules established for timing, because of the many conditions which determine the best times for opening and closing the valves. It is customary to try various settings when a new motor is designed until the most satisfactory points are determined, and the setting which will be very suitable for one motor is not always right for one of different design. The timing diagram shown at Fig. 108 applies to the Hall-Scott engine, and may be considered typical. It should be easily followed in view of the very complete explanation given in preceding pages. Another six-cylinder engine diagram is shown at Fig. 109, and an eight-cylinder timing diagram is shown at Fig. 110. In timing automobile engines no trouble is experienced, because timing marks are always indicated on the engine fly-wheel register with an indicating trammel on the crank-case. To time an airplane engine accurately, as is necessary to test for a suspected cam-shaft defect, a timing disc of aluminum is attached to the crank-shaft which has the timing marks indicated thereon. If the disc is made 10 or 12 inches in diameter, it may be divided into degrees without difficulty. [Illustration: Fig. 110.--Timing Diagram of Typical Eight-Cylinder V Engine.] HOW AN ENGINE IS TIMED In timing a motor from the marks on the timing disc rim it is necessary to regulate the valves of but one cylinder at a time. Assuming that the disc is revolving in the direction of engine rotation, and that the firing order of the cylinders is 1-3-4-2, the operation of timing would be carried on as follows: The crank-shaft would be revolved until the line marked "Exhaust opens 1 and 4" registered with the trammel on the motor bed. At this point the exhaust-valve of either cylinder No. 1 or No. 4 should begin to open. This can be easily determined by noting which of these cylinders holds the compressed charge ready for ignition. Assuming that the spark has occurred in cylinder No. 1, then when the fly-wheel is turned from the position to that in which the line marked "Exhaust opens 1 and 4" coincides with the trammel point, the valve-plunger under the exhaust-valve of cylinder No. 1 should be adjusted in such a way that there is no clearance between it and the valve stem. Further movement of the wheel in the same direction should produce a lift of the exhaust valve. The disc is turned about two hundred and twenty-five degrees, or a little less than three-quarters of a revolution; then the line marked "Exhaust closes 1 and 4" will register with the trammel point. At this period the valve-plunger and the valve-stem should separate and a certain amount of clearance obtain between them. The next cylinder to time would be No. 3. The crank-shaft is rotated until mark "Exhaust opens 2 and 3" comes in line with the trammel. At this point the exhaust valve of cylinder No. 3 should be just about opening. The closing is determined by rotating the shaft until the line "Exhaust closes 2 and 3" comes under the trammel. This operation is carried on with all the cylinders, it being well to remember that but one cylinder is working at a time and that a half-revolution of the fly-wheel corresponds to a full working stroke of all the cylinders, and that while one is exhausting the others are respectively taking in a new charge, compressing and exploding. For instance, if cylinder No. 1 has just completed its power-stroke, the piston in cylinder No. 3 has reached the point where the gas may be ignited to advantage. The piston of cylinder No. 4, which is next to fire, is at the bottom of its stroke and will have inspired a charge, while cylinder No. 2, which is the last to fire, will have just finished expelling a charge of burned gas, and will be starting the intake stroke. This timing relates to a four-cylinder engine in order to simplify the explanation. The timing instructions given apply only to the conventional motor types. Rotary cylinder engines, especially the Gnome "monosoupape," have a distinctive valve timing on account of the peculiarities of design. GNOME "MONOSOUPAPE" VALVE TIMING In the present design of the Gnome motor, a cycle of operations somewhat different from that employed in the ordinary four-cycle engine is made use of, says a writer in "The Automobile," in describing the action of this power-plant. This cycle does away with the need for the usual inlet valve and makes the engine operable with only a single valve, hence the name _monosoupape_, or "single-valve." The cycle is as follows: A charge being compressed in the outer end of the cylinder or combustion chamber, it is ignited by a spark produced by the spark-plug located in the side of this chamber, and the burning charge expands as the piston moves down in the cylinder while the latter revolves around the crank-shaft. When the piston is about half-way down on the power stroke, the exhaust valve, which is located in the center of the cylinder-head, is mechanically opened, and during the following upstroke of the piston the burnt gases are expelled from the cylinder through the exhaust valve directly into the atmosphere. Instead of closing at the end of the exhaust stroke, or a few degrees thereafter, the exhaust valve is held open for about two-thirds of the following inlet stroke of the piston, with the result that fresh air is drawn through the exhaust valve into the cylinder. When the cylinder is still 65 degrees from the end of the inlet half-revolution, the exhaust valve closes. As no more air can get into the cylinder, and as the piston continues to move inwardly, it is obvious that a partial vacuum is formed. When the cylinder approaches within 20 degrees of the end of the inlet half-revolution a series of small inlet ports all around the circumference of the cylinder wall is uncovered by the top edge of the piston, whereby the combustion chamber is placed in communication with the crank chamber. As the pressure in the crank chamber is substantially atmospheric and that in the combustion chamber is below atmospheric, there results a suction effect which causes the air from the crank chamber to flow into the combustion chamber. The air in the crank chamber is heavily charged with gasoline vapor, which is due to the fact that a spray nozzle connected with the gasoline supply tank is located inside the chamber. The proportion of gasoline vapor in the air in the crank chamber is several times as great as in the ordinary combustible mixture drawn from a carburetor into the cylinder. This extra-rich mixture is diluted in the combustion chamber with the air which entered it through the exhaust valve during the first part of the inlet stroke, thus forming a mixture of the proper proportion for complete combustion. The inlet ports in the cylinder wall remain open until 20 degrees of the compression half-revolution has been completed, and from that moment to near the end of the compression stroke the gases are compressed in the cylinder. Near the end of the stroke ignition takes place and this completes the cycle. The exact timing of the different phases of the cycle is shown in the diagram at Fig. 111. It will be seen that ignition occurs substantially 20 degrees ahead of the outer dead center, and expansion of the burning gases continues until 85 degrees past the outer dead center, when the piston is a little past half-stroke. Then the exhaust-valve opens and remains open for somewhat more than a complete revolution of the cylinders, or, to be exact, for 390 degrees of cylinder travel, until 115 degrees past the top dead center on the second revolution. Then for 45 degrees of travel the charge within the cylinder is expanded, whereupon the inlet ports are uncovered and remain open for 40 degrees of cylinder travel, 20 degrees on each side of the inward dead center position. SPRINGLESS VALVES Springless valves are the latest development on French racing car engines, and it is possible that the positively-operated types will be introduced on aviation engines also. Two makes of positively-actuated valves are shown at Fig. 112. The positive-valve motor differs from the conventional form by having no necessity for valve-springs, as a cam not only assures the opening of the valve, but also causes it to return to the valve-seat. In this respect it is much like the sleeve-valve motor, where the uncovering of the ports is absolutely positive. The cars equipped with these valves were a success in long-distance auto races. Claims made for this type of valve mechanism include the possibility of a higher number of revolutions and consequently greater engine power. With the spring-controlled, single-cam operated valve a point is reached where the spring is not capable of returning the valve to its seat before the cam has again begun its opening movement. It is possible to extend the limits considerably by using a light valve on a strong spring, but the valve still remains a limiting factor in the speed of the motor. [Illustration: Fig. 111.--Timing Diagram Showing Peculiar Valve Timing of Gnome "Monosoupape" Rotary Motor.] A part sectional view through a cylinder of an engine designed by G. Michaux is shown at Fig. 112, A. There are two valves per cylinder, inclined at about ten degrees from the vertical. The valve-stems are of large diameter, as owing to positive control, there is no necessity of lightening this part in an unusual degree. A single overhead cam-shaft has eight pairs of cams, which are shown in detail at B. For each valve there is a three-armed rocker, one arm of which is connected to the stem of the valve and the two others are in contact respectively with the opening and closing cams. The connection to the end of the valve-stem is made by a short connecting link, which is screwed on to the end of the valve-stem and locked in position. This allows some adjustment to be made between the valves and the actuating rocker. It will be evident that one cam and one rocker arm produce the opening of the valve and that the corresponding rocker arm and cam result in the closing of the valve. If the opening cam has the usual convex profile, the closing cam has a correspondingly concave profile. It will be noticed that a light valve-spring is shown in drawing. This is provided to give a final seating to its valve after it has been closed by the cam. This is not absolutely necessary, as an engine has been run successfully without these springs. The whole mechanism is contained within an overhead aluminum cover. [Illustration: Fig. 112.--Two Methods of Operating Valves by Positive Cam Mechanism Which Closes as Well as Opens Them.] The positive-valve system used on the De Lage motor is shown at D. In this the valves are actuated as shown in sectional views D and E. The valve system is unique in that four valves are provided per cylinder, two for exhaust and two for intake. The valves are mounted side by side, as shown at E, so the double actuator member may be operated by a single set of cams. The valve-operating member consists of a yoke having guide bars at the top and bottom. The actuating cam works inside of this yoke. The usual form of cam acts on the lower portion of the yoke to open the valve, while the concave cam acts on the upper part to close the valves. In this design provision is made for expansion of the valve-stems due to heat, and these are not positively connected to the actuating member. As shown at E, the valves are held against the seat by short coil springs at the upper end of the stem. These are very stiff and are only intended to provide for expansion. A slight space is left between the top of the valve-stem and the portion of the operating member that bears against them when the regular profile cam exerts its pressure on the bottom of the valve-operating mechanism. Another novelty in this motor design is that the cam-shafts and the valve-operating members are carried in casing attached above the motor by housing supports in the form of small steel pillars. The overhead cam-shafts are operated by means of bevel gearing. FOUR VALVES PER CYLINDER [Illustration: Fig. 113.--Diagram Comparing Two Large Valves and Four Small Ones of Practically the Same Area. Note How Easily Small Valves are Installed to Open Directly Into the Cylinder.] Mention has been previously made of the sixteen-valve four-cylinder Duesenberg motor and its great power output for the piston displacement. This is made possible by the superior volumetric efficiency of a motor provided with four valves in each cylinder instead of but two. This principle was thoroughly tried out in racing automobile motors, and is especially valuable in permitting of greater speed and power output from simple four- and six-cylinder engines. On eight- and twelve-cylinder types, it is doubtful if the resulting complication due to using a very large number of valves would be worth while. When extremely large valves are used, as shown in diagram at Fig. 113, it is difficult to have them open directly into the cylinder, and pockets are sometimes necessary. A large valve would weigh more than two smaller valves having an area slightly larger in the aggregate; it would require a stiffer valve spring on account of its greater weight. A certain amount of metal in the valve-head is necessary to prevent warping; therefore, the inertia forces will be greater in the large valve than in the two smaller valves. As a greater port area is obtained by the use of two valves, the gases will be drawn into the cylinder or expelled faster than with a lesser area. Even if the areas are practically the same as in the diagram at Fig. 113, the smaller valves may have a greater lift without imposing greater stresses on the valve-operating mechanism and quicker gas intake and exhaust obtained. The smaller valves are not affected by heat as much as larger ones are. The quicker gas movements made possible, as well as reduction of inertia forces, permits of higher rotative speed, and, consequently, greater power output for a given piston displacement. The drawings at Fig. 114 show a sixteen-valve motor of the four-cylinder type that has been designed for automobile racing purposes, and it is apparent that very slight modifications would make it suitable for aviation purposes. Part of the efficiency is due to the reduction of bearing friction by the use of ball bearings, but the multiple-valve feature is primarily responsible for the excellent performance. [Illustration: Fig. 114.--Sectional Views of Sixteen-Valve Four-Cylinder Automobile Racing Engine That May Have Possibilities for Aviation Service.] [Illustration: Fig. 115.--Front View of Curtiss OX-3 Aviation Motor, Showing Unconventional Valve Action by Concentric Push Rod and Pull Tube.] CHAPTER IX Constructional Details of Pistons--Aluminum Cylinders and Pistons--Piston Ring Construction--Leak Proof Piston Rings-- Keeping Oil Out of Combustion Chamber--Connecting Rod Forms-- Connecting Rods for Vee Engines--Cam-Shaft and Crank-Shaft Designs--Ball Bearing Crank-Shafts--Engine Base Construction. CONSTRUCTIONAL DETAILS OF PISTONS The piston is one of the most important parts of the gasoline motor inasmuch as it is the reciprocating member that receives the impact of the explosion and which transforms the power obtained by the combustion of gas to mechanical motion by means of the connecting rod to which it is attached. The piston is one of the simplest elements of the motor, and it is one component which does not vary much in form in different types of motors. The piston is a cylindrical member provided with a series of grooves in which packing rings are placed on the outside and two bosses which serve to hold the wrist pin in its interior. It is usually made of cast iron or aluminum, though in some motors where extreme lightness is desired, such as those used for aëronautic work, it may be made of steel. The use of the more resisting material enables the engineer to use lighter sections where it is important that the weight of this member be kept as low as possible consistent with strength. [Illustration: Fig. 116.--Forms of Pistons Commonly Employed in Gasoline Engines. A--Dome Head Piston and Three Packing Rings. B--Flat Top Form Almost Universally Used. C--Concave Piston Utilized in Knight Motors and Some Having Overhead Valves. D--Two-Cycle Engine Member with Deflector Plate Cast Integrally. E--Differential of Two-Diameter Piston Used in Some Engines Operating on Two-Cycle Principle.] A number of piston types are shown at Fig. 116. That at A has a round top and is provided with four split packing rings and two oil grooves. A piston of this type is generally employed in motors where the combustion chamber is large and where it is desired to obtain a higher degree of compression than would be possible with a flat top piston. This construction is also stronger because of the arched piston top. The most common form of piston is that shown at B, and it differs from that previously described only in that it has a flat top. The piston outlined in section at C is a type used on some of the sleeve-valve motors of the Knight pattern, and has a concave head instead of the convex form shown at A. The design shown at D in side and plan views is the conventional form employed in two-cycle engines. The deflector plate on the top of the cylinder is cast integral and is utilized to prevent the incoming fresh gases from flowing directly over the piston top and out of the exhaust port, which is usually opposite the inlet opening. On these types of two-cycle engines where a two-diameter cylinder is employed, the piston shown at E is used. This is known as a "differential piston," and has an enlarged portion at its lower end which fits the pumping cylinder. The usual form of deflector plate is provided at the top of the piston and one may consider it as two pistons in one. [Illustration: Fig. 117.--Typical Methods of Piston Pin Retention Generally Used in Engines of American Design. A--Single Set Screw and Lock Nut. B--Set Screw and Check Nut Fitting Groove in Wrist Pin. C, D--Two Locking Screws Passing Into Interior of Hollow Wrist Pin. E--Split Ring Holds Pin in Place. F--Use of Taper Expanding Plugs Outlined. G--Spring Pressed Plunger Type. H--Piston Pin Pinned to Connecting Rod. I--Wrist Pin Clamped in Connecting Rod Small End by Bolt.] [Illustration: Fig. 118.--Typical Piston and Connecting Rod Assembly.] [Illustration: Fig. 119.--Parts of Sturtevant Aviation Engine. A--Cylinder Head Showing Valves. B--Connecting Rod. C--Piston and Rings.] One of the important conditions in piston design is the method of securing the wrist pin which is used to connect the piston to the upper end of the connecting rod. Various methods have been devised to keep the pin in place, the most common of these being shown at Fig. 117. The wrist pin should be retained by some positive means which is not liable to become loose under the vibratory stresses which obtain at this point. If the wrist pin was free to move it would work out of the bosses enough so that the end would bear against the cylinder wall. As it is usually made of steel, which is a harder material than cast iron used in cylinder construction, the rubbing action would tend to cut a groove in the cylinder wall which would make for loss of power because it would permit escape of gas. The wrist pin member is a simple cylindrical element that fits the bosses closely, and it may be either hollow or solid stock. A typical piston and connecting rod assembly which shows a piston in section also is given at Fig. 118. The piston of the Sturtevant aëronautical motor is shown at Fig. 119, the aluminum piston of the Thomas airplane motor with piston rings in place is shown at Fig. 120. A good view of the wrist pin and connecting rod are also given. The iron piston of the Gnome "Monosoupape" airplane engine and the unconventional connecting rod assembly are clearly depicted at Fig 121. [Illustration: Fig. 120.--Aluminum Piston and Light But Strong Steel Connecting Rod and Wrist Pin of Thomas Aviation Engine.] The method of retention shown at A is the simplest and consists of a set screw having a projecting portion passing into the wrist pin and holding it in place. The screw is kept from turning or loosening by means of a check nut. The method outlined at B is similar to that shown at A, except that the wrist pin is solid and the point of the set screw engages an annular groove turned in the pin for its reception. A very positive method is shown at C. Here the retention screws pass into the wrist pin and are then locked by a piece of steel wire which passes through suitable holes in the ends. The method outlined at D is sometimes employed, and it varies from that shown at C only in that the locking wire, which is made of spring steel, is passed through the heads of the locking screws. Some designers machine a large groove around the piston at such a point that when the wrist pin is put in place a large packing ring may be sprung in the groove and utilized to hold the wrist pin in place. [Illustration: Fig. 121.--Cast Iron Piston of "Monosoupape" Gnome Engine Installed On One of the Short Connecting Rods.] The system shown at F is not so widely used as the simpler methods, because it is more costly and does not offer any greater security when the parts are new than the simple lock shown at A. In this a hollow wrist pin is used, having a tapered thread cut at each end. The wrist pin is slotted at three or four points, for a distance equal to the length of the boss, and when taper expansion plugs are screwed in place the ends of the wrist pin are expanded against the bosses. This method has the advantage of providing a certain degree of adjustment if the wrist pin should loosen up after it has been in use for some time. The taper plugs would be screwed in deeper and the ends of the wrist pin expanded proportionately to take up the loss motion. The method shown at G is an ingenious one. One of the piston bosses is provided with a projection which is drilled out to receive a plunger. The wrist pin is provided with a hole of sufficient size to receive the plunger, which is kept in place by means of a spring in back of it. This makes a very positive lock and one that can be easily loosened when it is desired to remove the wrist pin. To unlock, a piece of fine rod is thrust into the hole at the bottom of the boss which pushes the plunger back against the spring until the wrist pin can be pushed out of the piston. Some engineers think it advisable to oscillate the wrist pin in the piston bosses, instead of in the connecting rod small end. It is argued that this construction gives more bearing surface at the wrist pin and also provides for more strength because of the longer bosses that can be used. When this system is followed the piston pin is held in place by locking it to the connecting rod by some means. At H the simplest method is outlined. This consisted of driving a taper pin through both rod and wrist pin and then preventing it from backing out by putting a split cotter through the small end of the tapered locking pin. Another method, which is depicted at I, consists of clamping the wrist pin by means of a suitable bolt which brings the slit connecting rod end together as shown. ALUMINUM FOR CYLINDERS AND PISTONS Aluminum pistons outlined at Fig. 122, have replaced cast iron members in many airplane engines, as these weigh about one-third as much as the cast iron forms of the same size, while the reduction in the inertia forces has made it possible to increase the engine speed without correspondingly stressing the connecting rods, crank-shaft and engine bearings. [Illustration: Fig. 122.--Types of Aluminum Pistons Used In Aviation Engines.] Aluminum has not only been used for pistons, but a number of motors will be built for the coming season that will use aluminum cylinder block castings as well. Of course, the aluminum alloy is too soft to be used as a bearing for the piston, and it will not withstand the hammering action of the valve. This makes the use of cast iron or steel imperative in all motors. When used in connection with an aluminum cylinder block the cast iron pieces are placed in the mould so that they act as cylinder liners and valve seats, and the molten metal is poured around them when the cylinder is cast. It is said that this construction results in an intimate bond between the cast iron and the surrounding aluminum metal. Steel liners may also be pressed into the aluminum cylinders after these are bored out to receive them. Aluminum has for a number of years been used in many motor car parts. Alloys have been developed that have greater strength than cast iron and that are not so brittle. Its use for manifolds and engine crank and gear cases has been general for a number of years. At first thought it would seem as though aluminum would be entirely unsuited for use in those portions of internal combustion engines exposed to the heat of the explosion, on account of the low melting point of that metal and its disadvantageous quality of suddenly "wilting" when a critical point in the temperature is reached. Those who hesitated to use aluminum on account of this defect lost sight of the great heat conductivity of that metal, which is considerably more than that of cast iron. It was found in early experiments with aluminum pistons that this quality of quick radiation meant that aluminum pistons remained considerably cooler than cast iron ones in service, which was attested to by the reduced formation of carbon deposit thereon. The use of aluminum makes possible a marked reduction in power plant weight. A small four-cylinder engine which was not particularly heavy even with cast iron cylinders was found to weigh 100 pounds less when the cylinder block, pistons, and upper half of the crank-case had been made of aluminum instead of cast iron. Aluminum motors are no longer an experiment, as a considerable number of these have been in use on cars during the past year without the owners of the cars being apprised of the fact. Absolutely no complaint was made in any case of the aluminum motor and it was demonstrated, in addition to the saving in weight, that the motors cost no more to assemble and cooled much more efficiently than the cast iron form. One of the drawbacks to the use of aluminum is its growing scarcity, which results in making it a "near precious" metal. PISTON RING CONSTRUCTION As all pistons must be free to move up and down in the cylinder with minimum friction, they must be less in diameter than the bore of the cylinder. The amount of freedom or clearance provided varies with the construction of the engine and the material the piston is made of, as well as its size, but it is usual to provide from .005 to .010 of an inch to compensate for the expansion of the piston due to heat and also to leave sufficient clearance for the introduction of lubricant between the working surfaces. Obviously, if the piston were not provided with packing rings, this amount of clearance would enable a portion of the gases evolved when the charge is exploded to escape by it into the engine crank-case. The packing members or piston rings, as they are called, are split rings of cast iron, which are sprung into suitable grooves machined on the exterior of the piston, three or four of these being the usual number supplied. These have sufficient elasticity so that they bear tightly against the cylinder wall and thus make a gas-tight joint. Owing to the limited amount of surface in contact with the cylinder wall and the elasticity of the split rings the amount of friction resulting from the contact of properly fitted rings and the cylinder is not of enough moment to cause any damage and the piston is free to slide up and down in the cylinder bore. [Illustration: Fig. 123.--Types of Piston Rings and Ring Joints. A--Concentric Ring. B--Eccentrically Machined Form. C--Lap Joint Ring. D--Butt Joint, Seldom Used. E--Diagonal Cut Member, a Popular Form.] These rings are made in two forms, as outlined at Fig. 123. The design shown at A is termed a "concentric ring," because the inner circle is concentric with the outer one and the ring is of uniform thickness at all points. The ring shown at B is called an "eccentric ring," and it is thicker at one part than at others. It has theoretical advantages in that it will make a tighter joint than the other form, as it is claimed its expansion due to heat is more uniform. The piston rings must be split in order that they may be sprung in place in the grooves, and also to insure that they will have sufficient elasticity to take the form of the cylinder at the different points in their travel. If the cylinder bore varies by small amounts the rings will spring out at the points where the bore is larger than standard, and spring in at those portions where it is smaller than standard. It is important that the joint should be as nearly gas-tight as possible, because if it were not a portion of the gases would escape through the slots in the piston rings. The joint shown at C is termed a "lap joint," because the ends of the ring are cut in such a manner that they overlap. This is the approved joint. The butt joint shown at D is seldom used and is a very poor form, the only advantage being its cheapness. The diagonal cut shown at E is a compromise between the very good form shown at C and the poor joint depicted at D. It is also widely used, though most constructors prefer the lap joint, because it does not permit the leakage of gas as much as the other two types. There seems to be some difference of opinion relative to the best piston ring type--some favoring the eccentric pattern, others the concentric form. The concentric ring has advantages from the lubricating engineer's point of view; as stated by the Platt & Washburn Company in their text-book on engine lubrication, the smaller clearance behind the ring possible with the ring of uniform section is advantageous. Fig. 124, A, shows a concentric piston ring in its groove. Since the ring itself is concentric with the groove, very small clearance between the back of the ring and the bottom of its groove may be allowed. Small clearance leaves less space for the accumulation of oil and carbon deposits. The gasket effect of this ring is uniform throughout the entire length of its edges, which is its marked advantage over the eccentric ring. This type of piston ring rarely burns fast in its groove. There are a large number of different concentric rings manufactured of different designs and of different efficiency. [Illustration: Fig. 124.--Diagrams Showing Advantages of Concentric Piston Rings.] Figs. 124, B and 124, C show eccentric rings assembled in the ring groove. It will be noted that there is a large space between the thin ends of this ring and the bottom of the groove. This empty space fills up with oil which in the case of the upper ring frequently is carbonized, restricting the action of the ring and nullifying its usefulness. The edges of the thin ends are not sufficiently wide to prevent rapid escape of gases past them. In a practical way this leakage means loss of compression and noticeable drop in power. When new and properly fitted, very little difference can be noted between the tightness of eccentric and concentric rings. Nevertheless, after several months' use, a more rapid leakage will always occur past the eccentric than past the concentric. If continuous trouble with the carbonization of cylinders, smoking and sooting of spark-plugs is experienced, it is a sure indication that mechanical defects exist in the engine, assuming of course, that a suitable oil has been used. Such trouble can be greatly lessened, if not entirely eliminated, by the application of concentric rings (lap joint), of any good make, properly fitted into the grooves of the piston. Too much emphasis cannot be put upon this point. If the oil used in the engine is of the correct viscosity, and serious carbon deposit, smoking, etc., still result, the only certain remedy then is to have the cylinders rebored and fitted with properly designed, oversized pistons and piston rings. LEAK-PROOF PISTON RINGS In order to reduce the compression loss and leakage of gas by the ordinary simple form of diagonal or lap joint one-piece piston ring a number of compound rings have been devised and are offered by their makers to use in making replacements. The leading forms are shown at Fig. 125. That shown at A is known as the "Statite" and consists of three rings, one carried inside while the other two are carried on the outside. The ring shown at B is a double ring and is known as the McCadden. This is composed of two thin concentric lap joint rings so disposed relative to each other that the opening in the inner ring comes opposite to the opening in the outer ring. The form shown at C is known as the "Leektite," and is a single ring provided with a peculiar form of lap and dove tail joint. The ring shown at D is known as the "Dunham" and is of the double concentric type being composed of two rings with lap joints which are welded together at a point opposite the joint so that there is no passage by which the gas can escape. The Burd high compression ring is shown at E. The joints of these rings are sealed by means of an H-shaped coupler of bronze which closes the opening. The ring ends are made with tongues which interlock with the coupling. The ring shown at F is called the "Evertite" and is a three-piece ring composed of three members as shown in the sectional view below the ring. The main part or inner ring has a circumferential channel in which the two outer rings lock, the resulting cross-section being rectangular just the same as that of a regular pattern ring. All three rings are diagonally split and the joints are spaced equally and the distances maintained by small pins. This results in each joint being sealed by the solid portion of the other rings. [Illustration: Fig. 125.--Leak-Proof and Other Compound Piston Rings.] The use of a number of light steel rings instead of one wide ring in the groove is found on a number of automobile power plants, but as far as known, this construction is not used in airplane power plants. It is contended that where a number of light rings is employed a more flexible packing means is obtained and the possibility of leakage is reduced. Rings of this design are made of square section steel wire and are given a spring temper. Owing to the limited width the diagonal cut joint is generally employed instead of the lap joint which is so popular on wider rings. KEEPING OIL OUT OF COMBUSTION CHAMBERS An examination of the engine design that is economical in oil consumption discloses the use of tight piston rings, large centrifugal rings on the crank-shaft where it passes through the case, ample cooling fins in the pistons, vents between the crank-case chamber and the valve enclosures, etc. Briefly put, cooling of the oil in this engine has been properly cared for and leakage reduced to a minimum. To be specific regarding details of design: Oil surplus can be kept out of the explosion chambers by leaving the lower edge of the piston skirt sharp and by the use of a shallow groove (C), Fig. 126, just below the lower piston ring. Small holes are bored through the piston walls at the base of this groove and communicate with the crank-case. The similarity of the sharp edges of piston skirt (D) and piston ring to a carpenter's plane bit, makes their operation plain. [Illustration: Fig. 126.--Sectional View of Engine Showing Means of Preventing Oil Leakage By Piston Rings.] The cooling of oil in the sump (A) can be accomplished most effectively by radiating fins on its outer surface. The lower crank-case should be fully exposed to the outer air. A settling basin for sediment (B) should be provided having a cubic content not less than one-tenth of the total oil capacity as outlined at Fig. 126. The depth of this basin should be at least 2-1/2 inches, and its walls vertical, as shown, to reduce the mixing of sediment with the oil in circulation. The inlet opening to the oil pump should be near the top of the sediment basin in order to prevent the entrance into the pump with the oil of any solid matter or water condensed from the products of combustion. This sediment basin should be drained after every five to seven hours air service of an airplane engine. Concerning filtering screens there is little to be said, save that their areas should be ample and the mesh coarse enough (one-sixteenth of an inch) to offer no serious resistance to the free flow of cold or heavy oil through them; otherwise the oil in the crank-case may build up above them to an undesirable level. The necessary frequency of draining and flushing out the oil sump differs greatly with the age (condition) of the engine and the suitability of the oil used. In broad terms, the oil sump of a new engine should be thoroughly drained and flushed with kerosene at the end of the first 200 miles, next at the end of 500 miles and thereafter every 1,000 miles. While these instructions apply specifically to automobile motors, it is very good practice to change the oil in airplane engines frequently. In many cases, the best results have been secured when the oil supply is completely replenished every five hours that the engine is in operation. CONNECTING ROD FORMS The connecting rod is the simple member that joins the piston to the crank-shaft and which transmits the power imparted to the piston by the explosion so that it may be usefully applied. It transforms the reciprocating movement of the piston to a rotary motion at the crank-shaft. A typical connecting rod and its wrist pin are shown at Fig. 120. It will be seen that it has two bearings, one at either end. The small end is bored out to receive the wrist pin which joins it to the piston, while the large end has a hole of sufficient size to go on the crank-pin. The airplane and automobile engine connecting rod is invariably a steel forging, though in marine engines it is sometimes made a steel or high tensile strength bronze casting. In all cases it is desirable to have softer metals than the crank-shaft and wrist pin at the bearing point, and for this reason the connecting rod is usually provided with bushings of anti-friction or white metal at the lower end, and bronze at the upper. The upper end of the connecting rod may be one piece, because the wrist pin can be introduced after it is in place between the bosses of the piston. The lower bearing must be made in two parts in most cases, because the crank-shaft cannot be passed through the bearing owing to its irregular form. The rods of the Gnome engine are all one piece types, as shown at Fig. 127, owing to the construction of the "mother" rod which receives the crank-pins. The complete connecting rod assembly is shown in Fig. 121, also at A, Fig. 127. The "mother" rod, with one of the other rods in place and one about to be inserted, is shown at Fig. 127, B. The built-up crank-shaft which makes this construction feasible is shown at Fig. 127, C. [Illustration: Fig. 127.--Connecting Rod and Crank-Shaft Construction of Gnome "Monosoupape" Engine.] Some of the various designs of connecting rods that have been used are shown at Fig. 128. That at A is a simple form often employed in single-cylinder motors, having built-up crank-shafts. Both ends of the connecting rod are bushed with a one-piece bearing, as it can be assembled in place before the crank-shaft assembly is built up. A built-up crank-shaft such as this type of connecting rod would be used with is shown at Fig. 106. The pattern shown at B is one that has been used to some extent on heavy work, and is known as the "marine type." It is made in three pieces, the main portion being a steel forging having a flanged lower end to which the bronze boxes are secured by bolts. The modified marine type depicted at C is the form that has received the widest application in automobile and aviation engine construction. It consists of two pieces, the main member being a steel drop forging having the wrist-pin bearing and the upper crank-pin bearing formed integral, while the lower crank-pin bearing member is a separate forging secured to the connecting rod by bolts. In this construction bushings of anti-friction metal are used at the lower end, and a bronze bushing is forced into the upper- or wrist-pin end. The rod shown at D has also been widely used. It is similar in construction to the form shown at C, except that the upper end is split in order to permit of a degree of adjustment of the wrist-pin bushing, and the lower bearing cap is a hinged member which is retained by one bolt instead of two. When it is desired to assemble it on the crank-shaft the lower cap is swung to one side and brought back into place when the connecting rod has been properly located. Sometimes the lower bearing member is split diagonally instead of horizontally, such a construction being outlined at E. [Illustration: Fig. 128.--Connecting Rod Types Summarized. A--Single Connecting Rod Made in One Piece, Usually Fitted in Small Single-Cylinder Engines Having Built-Up Crank-Shafts. B--Marine Type, a Popular Form on Heavy Engines. C--Conventional Automobile Type, a Modified Marine Form. D--Type Having Hinged Lower Cap and Split Wrist Pin Bushing. E--Connecting Rod Having Diagonally Divided Big End. F--Ball-Bearing Rod. G--Sections Showing Structural Shapes Commonly Employed in Connecting Rod Construction.] In a number of instances, instead of plain bushed bearings anti-friction forms using ball or rollers have been used at the lower end. A ball-bearing connecting rod is shown at F. The big end may be made in one piece, because if it is possible to get the ball bearing on the crank-pins it will be easy to put the connecting rod in place. Ball bearings are not used very often on connecting rod big ends because of difficulty of installation, though when applied properly they give satisfactory service and reduce friction to a minimum. One of the advantages of the ball bearing is that it requires no adjustment, whereas the plain bushings depicted in the other connecting rods must be taken up from time to time to compensate for wear. This can be done in forms shown at B, C, D, and E by bringing the lower bearing caps closer to the upper one and scraping out the brasses to fit the shaft. A number of liners or shims of thin brass or copper stock, varying from .002 inch to .005 inch, are sometimes interposed between the halves of the bearings when it is first fitted to the crank-pin. As the brasses wear the shims may be removed and the portions of the bearings brought close enough together to take up any lost motion that may exist, though in some motors no shims are provided and depreciation can be remedied only by installing new brasses and scraping to fit. [Illustration: Fig. 129.--Double Connecting Rod Assembly For Use On Single Crank-Pin of Vee Engine.] The various structural shapes in which connecting rods are formed are shown in section at G. Of these the I section is most widely used in airplane engines, because it is strong and a very easy shape to form by the drop-forging process or to machine out of the solid bar when extra good steel is used. Where extreme lightness is desired, as in small high-speed motors used for cycle propulsion, the section shown at the extreme left is often used. If the rod is a cast member as in some marine engines, the cross, hollow cylinder, or U sections are sometimes used. If the sections shown at the right are employed, advantage is often taken of the opportunity for passing lubricant through the center of the hollow round section on vertical motors or at the bottom of the U section, which would be used on a horizontal cylinder power plant. [Illustration: Fig. 130.--Another Type of Double Connecting Rod for Vee Engines.] Connecting rods of Vee engines are made in two distinct styles. The forked or "scissors" joint rod assembly is employed when the cylinders are placed directly opposite each other. The "blade" rod, as shown at Fig. 129, fits between the lower ends of the forked rod, which oscillate on the bearing which encircles the crank-pin. The lower end of the "blade" rod is usually attached to the bearing brasses, the ends of the "forked" rod move on the outer surfaces of the brasses. Another form of rod devised for use under these conditions is shown at Fig. 130 and installed in an aviation engine at Fig. 132. In this construction the shorter rod is attached to a boss on the master rod by a short pin to form a hinge and to permit the short rod to oscillate as the conditions dictate. This form of rod can be easily adjusted when the bearing depreciates, a procedure that is difficult with the forked type rod. The best practice, in the writer's opinion, is to stagger the cylinders and use side-by-side rods as is done in the Curtiss engine. Each rod may be fitted independently of the other and perfect compensation for wear of the big ends is possible. [Illustration: Fig. 131.--Part Sectional View of Wisconsin Aviation Engine, Showing Four-Bearing Crank-Shaft, Overhead Cam-Shaft, and Method of Combining Cylinders in Pairs.] [Illustration: Fig. 132.--Part Sectional View of Renault Twelve-Cylinder Water-Cooled Engine, Showing Connecting Rod Construction and Other Important Internal Parts.] CAM-SHAFT AND CRANK-SHAFT DESIGN Before going extensively into the subject of crank-shaft construction it will be well to consider cam-shaft design, which is properly a part of the valve system and which has been considered in connection with the other elements which have to do directly with cylinder construction to some extent. Cam-shafts are usually simple members carried at the base of the cylinder in the engine case of Vee type motors by suitable bearings and having the cams employed to lift the valves attached at intervals. A typical cam-shaft design is shown at Fig. 133. Two main methods of cam-shaft construction are followed--that in which the cams are separate members, keyed and pinned to the shaft, and the other where the cams are formed integral, the latter being the most suitable for airplane engine requirements. [Illustration: Fig. 133.--Typical Cam-Shaft, with Valve Lifting Cams and Gears to Operate Auxiliary Devices Forged Integrally.] The cam-shafts shown at Figs. 133 and 134, B, are of the latter type, as the cams are machined integrally. In this case not only the cams but also the gears used in driving the auxiliary shafts are forged integral. This is a more expensive construction, because of the high initial cost of forging dies as well as the greater expense of machining. It has the advantage over the other form in which the cams are keyed in place in that it is stronger, and as the cams are a part of the shaft they can never become loose, as might be possible where they are separately formed and assembled on a simple shaft. [Illustration: Fig. 134.--Important Parts of Duesenberg Aviation Engine. A--Three Main Bearing Crank-Shaft. B--Cam-Shaft with Integral Cams. C--Piston and Connecting Rod Assembly. D--Valve Rocker Group. E--Piston. F--Main Bearing Brasses.] The importance of the crank-shaft has been previously considered, and some of its forms have been shown in views of the motors presented in earlier portions of this work. The crank-shaft is one of the parts subjected to the greatest strain and extreme care is needed in its construction and design, because practically the entire duty of transmitting the power generated by the motor to the gearset devolves upon it. Crank-shafts are usually made of high tensile strength steel of special composition. They may be made in four ways, the most common being from a drop or machine forging which is formed approximately to the shape of the finished shaft and in rare instances (experimental motors only) they may be steel castings. Sometimes they are made from machine forgings, where considerably more machine work is necessary than would be the case where the shaft is formed between dies. Some engineers favor blocking the shaft out of a solid slab of metal and then machining this rough blank to form. In some radial-cylinder motors of the Gnome and Le Rhone type the crank-shafts are built up of two pieces, held together by taper fastenings or bolts. [Illustration: Fig. 135.--Showing Method of Making Crank-Shaft. A--The Rough Steel Forging Before Machining. B--The Finished Six-Throw, Seven-Bearing Crank-Shaft.] The form of the shaft depends on the number of cylinders and the form has material influence on the method of construction. For instance, a four-cylinder crank-shaft could be made by either of the methods outlined. On the other hand, a three- or six-cylinder shaft is best made by the machine forging process, because if drop forged or cut from the blank it will have to be heated and the crank throws bent around so that the pins will lie in three planes one hundred and twenty degrees apart, while the other types described need no further attention, as the crank-pins lie in planes one hundred and eighty degrees apart. This can be better understood by referring to Fig. 135, which shows a six-cylinder shaft in the rough and finished stages. At A the appearance of the machine forging before any of the material is removed is shown, while at B the appearance of the finished crank-shaft is clearly depicted. The built-up crank-shaft is seldom used on multiple-cylinder motors, except in some cases where the crank-shafts revolve on ball bearings as in some automobile racing engines. [Illustration: Fig. 136.--Showing Form of Crank-Shaft for Twin-Cylinder Opposed Power Plant.] [Illustration: Fig. 137.--Crank-Shaft of Thomas-Morse Eight-Cylinder Vee Engine.] Crank-shaft form will vary with a number of cylinders and it is possible to use a number of different arrangements of crank-pins and bearings for the same number of cylinders. The simplest form of crank-shaft is that used on simple radial cylinder motors as it would consist of but one crank-pin, two webs, and the crank-shaft. As the number of cylinders increase in Vee motors as a general rule more crank-pins are used. The crank-shaft that would be used on a two-cylinder opposed motor is shown at Fig. 136. This has two throws and the crank-pins are spaced 180 degrees apart. The bearings are exceptionally long. Four-cylinder crank-shafts may have two, three or five main bearings and three or four crank-pins. In some forms of two-bearing crank-shafts, such as used when four-cylinders are cast in a block, or unit casting, two of the pistons are attached to one common crank-pin, so that in reality the crank-shaft has but three crank-pins. A typical three bearing, four-cylinder crank-shaft is shown at Fig. 134, A. The same type can be used for an eight-cylinder Vee engine, except for the greater length of crank-pins to permit of side by side rods as shown at Fig. 137. Six cylinder vertical tandem and twelve-cylinder Vee engine crank-shafts usually have four or seven main bearings depending upon the disposition of the crank-pins and arrangement of cylinders. At Fig. 138, A, the bottom view of a twelve-cylinder engine with bottom half of crank case removed is given. This illustrates clearly the arrangement of main bearings when the crank-shaft is supported on four journals. The crank-shaft shown at Fig. 138, B, is a twelve-cylinder seven-bearing type. [Illustration: Fig. 138.--Crank-Case and Crank-Shaft Construction for Twelve-Cylinder Motors. A--Duesenberg. B--Curtiss.] [Illustration: Fig. 139.--Counterbalanced Crank-Shafts Reduce Engine Vibration and Permit of Higher Rotative Speeds.] In some automobile engines, extremely good results have been secured in obtaining steady running with minimum vibration by counterbalancing the crank-shafts as outlined at Fig. 139. The shaft at A is a type suitable for a high speed four-cylinder vertical or an eight-cylinder Vee type. That at B is for a six-cylinder vertical or a twelve-cylinder V with scissors joint rods. If counterbalancing crank-shafts helps in an automobile engine, it should have advantages of some moment in airplane engines, even though the crank-shaft weight is greater. BALL-BEARING CRANK-SHAFTS While crank-shafts are usually supported in plain journals there seems to be a growing tendency of late to use anti-friction bearings of the ball type for their support. This is especially noticeable on block motors where but two main bearings are utilized. When ball bearings are selected with proper relation to the load which obtains they will give very satisfactory service. They permit the crank-shaft to turn with minimum friction, and if properly selected will never need adjustment. The front end is supported by a bearing which is clamped in such a manner that it will take a certain amount of load in a direction parallel to the axis of the shaft, while the rear end is so supported that the outer race of the bearing has a certain amount of axial freedom or "float." The inner race or cone of each bearing is firmly clamped against shoulders on the crank-shaft. At the front end of the crank-shaft timing gear and a suitable check nut are used, while at the back end the bearing is clamped by a threaded retention member between the fly-wheel and a shoulder on the crank-shaft. The fly-wheel is held in place by a taper and key retention. The ball bearings are carried in a light housing of bronze or malleable iron, which in turn are held in the crank-case by bolts. The Renault engine uses ball bearings at front and rear ends of the crank-shaft, but has plain bearings around intermediate crank-shaft journals. The rotary engines of the Gnome, Le Rhone and Clerget forms would not be practical if ball bearings were not used as the bearing friction and consequent depreciation would be very high. ENGINE-BASE CONSTRUCTION One of the important parts of the power plant is the substantial casing or bed member, which is employed to support the cylinders and crank-shaft and which is attached directly to the fuselage engine supporting members. This will vary widely in form, but as a general thing it is an approximately cylindrical member which may be divided either vertically or horizontally in two or more parts. Airplane engine crank-cases are usually made of aluminum, a material which has about the same strength as cast iron, but which only weighs a third as much. In rare cases cast iron is employed, but is not favored by most engineers because of its brittle nature, great weight and low resistance to tensile stresses. Where exceptional strength is needed alloys of bronze may be used, and in some cases where engines are produced in large quantities a portion of the crank-case may be a sheet steel or aluminum stamping. [Illustration: Fig. 140.--View of Thomas 135 Horse-Power Aeromotor, Model 8, Showing Conventional Method of Crank-Case Construction.] [Illustration: Fig. 141.--Views of Upper Half of Thomas Aeromotor Crank-Case.] Crank-cases are always large enough to permit the crank-shaft and parts attached to it to turn inside and obviously its length is determined by the number of cylinders and their disposition. The crank-case of the radial cylinder or double-opposed cylinder engine would be substantially the same in length. That of a four-cylinder will vary in length with the method of casting the cylinder. When the four-cylinders are cast in one unit and a two-bearing crank-shaft is used, the crank-case is a very compact and short member. When a three-bearing crank-shaft is utilized and the cylinders are cast in pairs, the engine base is longer than it would be to support a block casting, but is shorter than one designed to sustain individual cylinder castings and a five-bearing crank-shaft. It is now common construction to cast an oil container integral with the bottom of the engine base and to draw the lubricating oil from it by means of a pump, as shown at Fig. 140. The arms by which the motor is supported in the fuselage are substantial-ribbed members cast integrally with the upper half. [Illustration: Fig. 142.--Method of Constructing Eight-Cylinder Vee Engine, Possible if Aluminum Cylinder and Crank-Case Castings are Used.] [Illustration: Fig. 143.--Simple and Compact Crank-Case, Possible When Radial Cylinder Engine Design is Followed.] The approved method of crank-case construction favored by the majority of engineers is shown at the top of Fig. 141, bottom side up. The upper half not only forms a bed for the cylinder but is used to hold the crank-shaft as well. In the illustration, the three-bearing boxes form part of the case, while the lower brasses are in the form of separately cast caps retained by suitable bolts. In the construction outlined the bottom part of the case serves merely as an oil container and a protection for the interior mechanism of the motor. The cylinders are held down by means of studs screwed into the crank-case top, as shown at Fig. 141, lower view. If the aluminum cylinder motor has any future, the method of construction outlined at Fig. 142, which has been used in cast iron for an automobile motor, might be used for an eight-cylinder Vee engine for airplane use. The simplicity of the crank-case needed for a revolving cylinder motor and its small weight can be well understood by examination of the illustration at Fig. 143, which shows the engine crank-case for the nine-cylinder "Monosoupape" Gnome engine. This consists of two accurately machined forgings held together by bolts as clearly indicated. CHAPTER X Power Plant Installation--Curtiss OX-2 Engine Mounting and Operating Rules--Standard S. A. E. Engine Bed Dimensions-- Hall-Scott Engine Installation and Operation--Fuel System Rules --Ignition System--Water System--Preparations to Start Engine-- Mounting Radial and Rotary Engines--Practical Hints to Locate Engine Troubles--All Engine Troubles Summarized--Location of Engine Troubles Made Easy. The proper installation of the airplane power plant is more important than is generally supposed, as while these engines are usually well balanced and run with little vibration, it is necessary that they be securely anchored and that various connections to the auxiliary parts be carefully made in order to prevent breakage from vibration and that attendant risk of motor stoppage while in the air. The type of motor to be installed determines the method of installation to be followed. As a general rule six-cylinder vertical engine and eight-cylinder Vee type are mounted in substantially the same way. The radial, fixed cylinder forms and the radial, rotary cylinder Gnome and Le Rhone rotary types require an entirely different method of mounting. Some unconventional mountings have been devised, notably that shown at Fig. 144, which is a six-cylinder German engine that is installed in just the opposite way to that commonly followed. The inverted cylinder construction is not generally followed because even with pressure feed, dry crank-case type lubricating system there is considerable danger of over-lubrication and of oil collecting and carbonizing in the combustion chamber and gumming up the valve action much quicker than would be the case if the engine was operated in the conventional upright position. The reason for mounting an engine in this way is to obtain a lower center of gravity and also to make for more perfect streamlining of the front end of the fuselage in some cases. It is rather doubtful if this slight advantage will compensate for the disadvantages introduced by this unusual construction. It is not used to any extent now but is presented merely to show one of the possible systems of installing an airplane engine. [Illustration: Fig. 144.--Unconventional Mounting of German Inverted Cylinder Motor.] [Illustration: Fig. 145.--How Curtiss Model OX-2 Motor is Installed in Fuselage of Curtiss Tractor Biplane. Note Similarity of Mounting to Automobile Power Plant.] In a number of airplanes of the tractor-biplane type the power plant installation is not very much different than that which is found in automobile practice. The illustration at Fig. 145 is a very clear representation of the method of mounting the Curtiss eight-cylinder 90 H. P. or model OX-2 engine in the fuselage of the Curtiss JN-4 tractor biplane which is so generally used in the United States as a training machine. It will be observed that the fuel tank is mounted under a cowl directly behind the motor and that it feeds the carburetor by means of a flexible fuel pipe. As the tank is mounted higher than the carburetor, it will feed that member by gravity. The radiator is mounted at the front end of the fuselage and connected to the water piping on the motor by the usual rubber hose connections. An oil pan is placed under the engine and the top is covered with a hood just as in motor car practice. The panels of aluminum are attached to the sides of the fuselage and are supplied with doors which open and provide access to the carburetor, oil-gauge and other parts of the motor requiring inspection. The complete installation with the power plant enclosed is given at Fig. 146, and in this it will be observed that the exhaust pipes are connected to discharge members that lead the gases above the top plane. In the engine shown at Fig. 145 the exhaust flows directly into the air at the sides of the machine through short pipes bolted to the exhaust gas outlet ports. The installation of the radiator just back of the tractor screw insures that adequate cooling will be obtained because of the rapid air flow due to the propeller slip stream. [Illustration: Fig. 146.--Latest Model of Curtiss JN-4 Training Machine, Showing Thorough Enclosure of Power Plant and Method of Disposing of the Exhaust Gases.] INSTALLATION OF CURTISS OX-2 ENGINE [Illustration: Fig. 147.--Front View of L. W. F. Tractor Biplane Fuselage, Showing Method of Installing Thomas Aeromotor and Method of Disposing of Exhaust Gases.] The following instructions are given in the Curtiss Instruction Book for installing the OX-2 engine and preparing it for flights, and taken in connection with the very clear illustration presented no difficulty should be experienced in understanding the proper installation, and mounting of this power plant. The bearers or beds should be 2 inches wide by 3 inches deep, preferably of laminated hard wood, and placed 11-5/8 inches apart. They must be well braced. The six arms of the base of the motor are drilled for 3/8-inch bolts, and none but this size should he used. 1. _Anchoring the Motor._ Put the bolts in from the bottom, with a large washer under the head of each so the head cannot cut into the wood. On every bolt use a castellated nut and a cotter pin, or an ordinary nut and a lock washer, so the bolt will not work loose. Always set motor in place and fasten before attaching any auxiliary apparatus, such as carburetor, etc. 2. _Inspecting the Ignition-Switch Wires._ The wires leading from the ignition switch must be properly connected--one end to the motor body for ground, and the other end to the post on the breaker box of the magneto. 3. _Filling the Radiator._ Be sure that the water from the radiator fills the cylinder jackets. Pockets of air may remain in the cylinder jackets even though the radiator may appear full. Turn the motor over a few times by hand after filling the radiator, and then add more water if the radiator will take it. The air pockets, if allowed to remain, may cause overheating and develop serious trouble when the motor is running. 4. _Filling the Oil Reservoir._ Oil is admitted into the crank-case through the breather tube at the rear. It is well to strain all oil put into the crank-case. In filling the oil reservoir be sure to turn the handle on the oil sight-gauge till it is at right angles with the gauge. The oil sight-gauge is on the side of the lower half of the crank-case. Put in about 3 gallons of the best obtainable oil, Mobile B recommended. It is important to remember that the very best oil is none too good. 5. _Oiling Exposed Moving Parts._ Oil all rocker-arm bearings before each flight. A little oil should be applied where the push rods pass through the stirrup straps. 6. _Filling the Gasoline Tanks._ Be certain that all connections in the gasoline system are tight. 7. _Turning on the Gasoline._ Open the cock leading from the gasoline tank to the carburetor. 8. _Charging the Cylinders._ With the ignition switch OFF, prime the motor by squirting a little gasoline in each exhaust port and then turn the propeller backward two revolutions. Never open the exhaust valve by operating the rocker-arm by hand, as the push-rod is liable to come out of its socket in the cam follower and bend the rocker-arm when the motor turns over. 9. _Starting the Motor by Hand._ Always retard the spark part way, to prevent back-firing, by pulling forward the wire attached to the breaker box. Failure to so retard the spark in starting may result in serious injury to the operator. Turn on the ignition switch with throttle partly open; give a quick, strong pull down and outward on the starting crank or propeller. As soon as the motor is started advance the spark by releasing the retard wire. 10. _Oil Circulation._ Let the motor run at low speed for a few minutes in order to establish oil circulation in all bearings. With all parts functioning properly, the throttle may be opened gradually for warming up before flight. STANDARD S.A.E. ENGINE BED DIMENSIONS The Society of Automotive Engineers have made efforts to standardize dimensions of bed timbers for supporting power plant in an aeroplane. Owing to the great difference in length no standardization is thought possible in this regard. The dimensions recommended are as follows: Distance between timbers 12 in. 14 in. 16 in. Width of bed timbers 1-1/2 in. 1-3/4 in. 2 in. Distance between centers of bolts 13-1/2 in. 15-3/4 in. 18 in. It will be evident that if any standard of this nature were adopted by engine builders that the designers of fuselage could easily arrange their bed timbers to conform to these dimensions, whereas it would be difficult to have them adhere to any standard longitudinal dimensions which are much more easily varied in fuselages than the transverse dimensions are. It, however, should be possible to standardize the longitudinal positions of the holding down bolts as the engine designer would still be able to allow himself considerable space fore-and-aft of the bolts. [Illustration: Fig. 148.--End Elevation of Hall-Scott A-7 Four-Cylinder Motor, with Installation Dimensions.] HALL-SCOTT ENGINE INSTALLATION [Illustration: Fig. 149.--Plan and Side Elevation of Hall-Scott A-7 Four-Cylinder Airplane Engine, with Installation Dimensions.] The very thorough manner in which installation diagrams are prepared by the leading engine makers leaves nothing to the imagination. The dimensions of the Hall-Scott four-cylinder airplane engine are given clearly in our inch measurements with the metric equivalents at Figs. 148 and 149, the former showing a vertical elevation while the latter has a plan view and side elevation. The installation of this engine in airplanes is clearly shown at Figs. 150 and 151, the former having the radiator installed at the front of the motor and having all exhaust pipes joined to one common discharge funnel, which deflects the gas over the top plane while the latter has the radiator placed vertically above the motor at the back end and has a direct exhaust gas discharge to the air. [Illustration: Fig. 150. CENSORED] [Illustration: Fig. 151. CENSORED] The dimensions of the six-cylinder Hall-Scott motor which is known as the type A-5 125 H. P. are given at Fig. 152, which is an end sectional elevation, and at Fig. 153, which is a plan view. The dimensions are given both in inch sizes and the metric equivalents. The appearance of a Hall-Scott six-cylinder engine installed in a fuselage is given at Fig. 154, while a diagram showing the location of the engine and the various pipes leading to the auxiliary groups is outlined at Fig. 155. The following instructions for installing the Hall-Scott power plant are reproduced from the instruction book issued by the maker. Operating instructions which are given should enable any good mechanic to make a proper installation and to keep the engine in good running condition. [Illustration: Fig. 152. CENSORED] FUEL SYSTEM INSTALLATION [Illustration: Fig. 153.--Plan View of Hall-Scott Type A-5 125 Horse-Power Airplane Engine, Showing Installation Dimensions.] Gasoline giving the best results with this equipment is as follows: Gravity 58-62 deg. Baume A. Initial boiling point--Richmond method--102° Fahr. Sulphur .014. Calorimetric bomb test 20610 B. T. U. per pound. If the gasoline tank is placed in the fuselage below the level of the carburetor, a hand pump must be used to maintain air pressure in gas tank to force the gasoline to the carburetor. After starting the engine the small auxiliary air pump upon the engine will maintain sufficient pressure. A-7a and A-5a engines are furnished with a new type auxiliary air pump. This should be frequently oiled and care taken so no grit or sand will enter which might lodge between the valve and its seat, which would make it fail to operate properly. An air relief valve is furnished with each engine. It should be screwed into the gas tank and properly regulated to maintain the pressure required. This is done by screwing the ratchet on top either up or down. If two tanks are used in a plane one should be installed in each tank. All air pump lines should be carefully gone over quite frequently to ascertain if they are tight. Check valves have to be placed in these lines. In some cases the gasoline tank is placed above the engine, allowing it to drain by gravity to the carburetor. When using this system there should be a drop of not less than two feet from the lowest portion of the gasoline tank to the upper part of the carburetor float chamber. Even this height might not be sufficient to maintain the proper volume of gasoline to the carburetor at high speeds. Air pressure is advised upon all tanks to insure the proper supply of gasoline. When using gravity feed without air pressure be sure to vent the tank to allow circulation of air. If gravity tank is used and the engine runs satisfactorily at low speeds but cuts out at high speeds the trouble is undoubtedly due to insufficient height of the tank above the carburetor. The tank should be raised or air pressure system used. [Illustration: Fig. 154.--Three-Quarter View of Hall-Scott Type A-5 125 Horse-Power Six-Cylinder Engine, with One of the Side Radiators Removed to Show Installation in Standard Fuselage.] [Illustration: Fig. 155.--Diagram Showing Proper Installation of Hall-Scott Type A-5 125 Horse-Power Engine with Pressure Feed Fuel Supply System.] IGNITION SWITCHES Two "DIXIE" switches are furnished with each engine. Both of these should be installed in the pilot's seat, one controlling the R. H., and the other the L. H. magneto. By shorting either one or the other it can be quickly determined if both magnetos, with their respective spark-plugs, are working correctly. Care should be taken not to use spark-plugs having _special extensions or long protruding points_. Plugs giving best results are extremely small with short points. WATER SYSTEMS A temperature gauge should be installed in the water pipe, coming directly from the cylinder nearest the propeller (note illustration above). This instrument installed in the radiator cap has not always given satisfactory results. This is especially noticeable when the water in the radiator becomes low, not allowing it to touch the bulb on the moto-meter. For ordinary running, it should not indicate over 150 degrees Fahr. In climbing tests, however, a temperature of 160 degrees Fahr. can be maintained without any ill effects upon the engine. In case the engine becomes overheated, the indicator will register above 180 degrees Fahr., in which case it should be stopped immediately. Overheating is most generally caused by retarded spark, excessive carbon in the cylinders, insufficient lubrication, improperly timed valves, lack of water, clogging of water system in any way which would obstruct the free circulation of the water. Overheating will cause the engine to knock, with possible damaging results. Suction pipes should be made out of thin tubing, and run within a quarter or an eighth of an inch of each other, so that when a hose is placed over the two, it will not be possible to suck together. This is often the case when a long rubber hose is used, which causes overheating. Radiators should be flushed out and cleaned thoroughly quite often. A dirty radiator may cause overheating. When filling the radiator it is very important to remove the plug on top of the water pump until water appears. This is to avoid air pockets being formed in the circulating system, which might not only heat up the engine, but cause considerable damage. All water pump hoses and connections should be tightly taped and shellacked after the engine is properly installed in the plane. The greatest care should be taken when making engine installation _not_ to use smaller inside diameter hose connection than water pump suction end casting. One inch and a quarter inside diameter should be used on A-7 and A-5 motors, while nothing less than one inch and a half inside diameter hose or tubing on all A-7a and A-5a engines. It is further important to have light spun tubing, void of any sharp turns, leads from pump to radiator and cylinder water outlet to radiator. In other words, the water circulation through the engine must be as little restricted as possible. Be sure no light hose is used, that will often suck together when engine is started. To thoroughly drain the water from the entire system, open the drain cock at the lowest side of the water pump. PREPARATIONS TO START ENGINE Always replenish gasoline tanks through a strainer which is clean. This strainer must catch all water and other impurities in the gasoline. Pour at least three gallons of fresh oil into the lower crank-case. Oil all rocker arms through oilers upon rocker arm housing caps. Be sure radiators are filled within one inch of the top. After all the parts are oiled, and the tanks filled, the following must be looked after before starting: See if crank-shaft flange is tight on shaft. See if propeller bolts are tight and evenly drawn up. See if propeller bolts are wired. See if propeller is trued up to within 1/8". Every four days the magnetos should be oiled if the engine is in daily use. Every month all cylinder hold-down nuts should be gone over to ascertain if they are tight. (Be sure to recotter nuts.) See if magnetos are bolted on tight and wired. See if magneto cables are in good condition. See if rocker arm tappets have a .020" clearance from valve stem when valve is seated. See if tappet clamp screws are tight and cottered. See if all gasoline, oil, water pipes and connections are in perfect condition. Air on gas line should be tested for leaks. Pump at least three pounds air pressure into gasoline tank. After making sure that above rules have been observed, test compression of cylinders by turning propeller. "DO NOT FORGET TO SHORT BOTH MAGNETOS" Be sure all compression release and priming cocks do not leak compression. If they do, replace same with a new one immediately, as this might cause premature firing. Open priming cocks and squirt some gasoline into each. Close cocks. Open compression release cocks. Open throttle slightly. If using Berling magnetos they should be three-quarters advanced. If all the foregoing directions have been carefully followed, the engine is ready for starting. In cranking engine either by starting crank, or propeller, it is essential to throw it over compression quickly. Immediately upon starting, close compression release cocks. When engine is running, advance magnetos. After it has warmed up, short one magneto and then the other, to be sure both magnetos and spark-plugs are firing properly. If there is a miss, the fouled plug must be located and cleaned. There is a possibility that the jets in the carburetor are stopped up. If this is the case, do not attempt to clean same with any sharp instrument. If this is done, it might change the opening in the jets, thus spoiling the adjustment. Jets and nozzles should be blown out with air or steam. An open intake or exhaust valve, which might have become sluggish or stuck from carbon, might cause trouble. Be sure to remedy this at once by using a little coal-oil or kerosene on same, working the valve by hand until it becomes free. We recommend using graphite on valve stems mixed with oil to guard against sticking or undue wear. INSTALLING ROTARY AND RADIAL CYLINDER ENGINES [Illustration: Fig. 156.--Diagram Defining Installation of Gnome "Monosoupape" Motor in Tractor Biplane. Note Necessary Piping for Fuel, Oil, and Air Lines.] When rotary engines are installed simple steel stamping or "spiders," are attached to the fuselage to hold the fixed crank-shaft. Inasmuch as the motor projects clear of the fuselage proper there is plenty of room back of the front spider plate to install the auxiliary parts such as the oil pump, air pump and ignition magneto and also the fuel and oil containers. The diagram given at Fig. 156 shows how a Gnome "monosoupape" engine is installed on the anchorage plates and it also outlines clearly the piping necessary to convey the oil and fuel and also the air-piping needed to put pressure on both fuel and oil tanks to insure positive supply of these liquids which may be carried in tanks placed lower than the motor in some installations. The diagram given at Figs. 157 and 158 shows other mountings of Gnome engines and are self-explanatory. The simple mounting possible when the Anzani ten-cylinder radial fixed type engine is used given at Fig. 159. The front end of the fuselage is provided with a substantial pressed steel plate having members projecting from it which may be bolted to the longerons. The bolts that hold the two halves of the crank-case together project through the steel plate and hold the engine securely to the front end of the fuselage. [Illustration: Fig. 157.--Showing Two Methods of Placing Propeller on Gnome Rotary Motor.] PRACTICAL HINTS TO LOCATE ENGINE TROUBLES [Illustration: Fig. 158.--How Gnome Rotary Motor May Be Attached to Airplane Fuselage Members.] One who is not thoroughly familiar with engine construction will seldom locate troubles by haphazard experimenting and it is only by a systematic search that the cause can be discovered and the defects eliminated. In this chapter the writer proposes to outline some of the most common power-plant troubles and to give sufficient advice to enable those who are not thoroughly informed to locate them by a logical process of elimination. The internal-combustion motor, which is the power plant of all gasoline automobiles as well as airplanes, is composed of a number of distinct groups, which in turn include distinct components. These various appliances are so closely related to each other that defective action of any one may interrupt the operation of the entire power plant. Some of the auxiliary groups are more necessary than others and the power plant will continue to operate for a time even after the failure of some important parts of some of the auxiliary groups. The gasoline engine in itself is a complete mechanism, but it is evident that it cannot deliver any power without some means of supplying gas to the cylinders and igniting the compressed gas charge after it has been compressed in the cylinders. From this it is patent that the ignition and carburetion systems are just as essential parts of the power plant as the piston, connecting rod, or cylinder of the motor. The failure of either the carburetor or igniting means to function properly will be immediately apparent by faulty action of the power plant. [Illustration: Fig. 159.--How Anzani Ten-Cylinder Radial Engine is Installed to Plate Securely Attached to Front End of Tractor Airplane Fuselage.] To insure that the motor will continue to operate it is necessary to keep it from overheating by some form of cooling system and to supply oil to the moving parts to reduce friction. The cooling and lubrication groups are not so important as carburetion and ignition, as the engine would run for a limited period of time even should the cooling system fail or the oil supply cease. It would only be a few moments, however, before the engine would overheat if the cooling system was at fault, and the parts seize if the lubricating system should fail. Any derangement in the carburetor or ignition mechanism would manifest itself at once because the engine operation would be affected, but a defect in the cooling or oiling system would not be noticed so readily. The careful aviator will always inspect the motor mechanism before starting on a trip of any consequence, and if inspection is carefully carried out and loose parts tightened it is seldom that irregular operation will be found due to actual breakage of any of the components of the mechanism. Deterioration due to natural causes matures slowly, and sufficient warning is always given when parts begin to wear so satisfactory repairs may be promptly made before serious derangement or failure is manifested. A TYPICAL ENGINE STOPPAGE ANALYZED Before describing the points that may fail in the various auxiliary systems it will be well to assume a typical case of engine failure and show the process of locating the trouble in a systematic manner by indicating the various steps which are in logical order and which could reasonably be followed. In any case of engine failure the ignition system, motor compression, and carburetor should be tested first. If the ignition system is functioning properly one should determine the amount of compression in all cylinders and if this is satisfactory the carbureting group should be tested. If the ignition system is working properly and there is a decided resistance in the cylinders when the propeller is turned, proving that there is good compression, one may suspect the carburetor. [Illustration: Fig. 160.--Side Elevation of Thomas 135 Horse-Power Airplane Engine, Giving Important Dimensions.] If the carburetor appears to be in good condition, the trouble may be caused by the ignition being out of time, which condition is possible when the magneto timing gear or coupling is attached to the armature shaft by a taper and nut retention instead of the more positive key or taper-pin fastening. It is possible that the inlet manifold may be broken or perforated, that the exhaust valve is stuck on its seat because of a broken or bent stem, broken or loose cam, or failure of the cam-shaft drive because the teeth are stripped from the engine shaft or cam-shaft gears; or because the key or other fastening on either gear has failed, allowing that member to turn independently of the shaft to which it normally is attached. The gasoline feed pipe may be clogged or broken, the fuel supply may be depleted, or the shut-off cock in the gasoline line may have jarred closed. The gasoline filter may be filled with dirt or water which prevents passage of the fuel. [Illustration: Fig. 161.--Front Elevation of Thomas-Morse 135 Horse-Power Aeromotor, Showing Main Dimensions.] The defects outlined above, except the failure of the gasoline supply, are very rare, and if the container is found to contain fuel and the pipe line to be clear to the carburetor, it is safe to assume the vaporizing device is at fault. If fuel continually runs out of the mixing chamber the carburetor is said to be flooded. This condition results from failure of the shut-off needle to seat properly or from a punctured hollow metal float or a gasoline-soaked cork float. It is possible that not enough gasoline is present in the float chamber. If the passage controlled by the float-needle valve is clogged or if the float was badly out of adjustment, this contingency would be probable. When the carburetor is examined, if the gasoline level appears to be at the proper height, one may suspect that a particle of lint, or dust, or fine scale, or rust from the gasoline tank has clogged the bore of the jet in the mixing chamber. If the ignition system and carburetor appear to be in good working order, and the hand crank shows that there is no compression in one or more of the cylinders, it means some defect in the valve system. If the engine is a multiple-cylinder type and one finds poor compression in all of the cylinders it may be due to the rare defect of improper valve timing. This may be caused by a gear having altered its position on the cam-shaft or crank-shaft, because of a sheared key or pin having permitted the gear to turn about half of a revolution and then having caught and held the gear in place by a broken or jagged end so that cam-shaft would turn, but the valves open at the wrong time. If but one of the cylinders is at fault and the rest appear to have good compression the trouble may be due to a defective condition either inside or outside of that cylinder. The external parts may be inspected easily, so the following should be looked for: a broken valve, a warped valve-head, broken valve-springs, sticking or bent valve-stems, dirt under valve-seat, leak at valve-chamber cap or spark-plug gasket. Defective priming cock, cracked cylinder head (rarely occurs), leak through cracked spark-plug insulation, valve-plunger stuck in the guide, lack of clearance between valve-stem end and top of plunger caused by loose adjusting screw which has worked up and kept the valve from seating. The faulty compression may be due to defects inside the motor. The piston-head may be cracked (rarely occurs), piston rings may be broken, the slots in the piston rings may be in line, the rings may have lost their elasticity or have become gummed in the grooves of the piston, or the piston and cylinder walls may be badly scored by a loose wrist pin or by defective lubrication. If the motor is a type with a separate head it is possible the gasket or packing between the cylinder and combustion chamber may leak, either admitting water to the cylinder or allowing compression to escape. [Illustration: Fig. 162.--Front and Side Elevations of Sturtevant Airplane Engine, Giving Principal Dimensions to Facilitate Installation.] CONDITIONS THAT CAUSE FAILURE OF IGNITION SYSTEM If the first test of the motor had showed that the compression was as it should be and that there were no serious mechanical defects and there was plenty of gasoline at the carburetor, this would have demonstrated that the ignition system was not functioning properly. If a battery is employed to supply current the first step is to take the spark-plugs out of the cylinders and test the system by turning over the engine by hand. If there is no spark in any of the plugs, this may be considered a positive indication that there is a broken main current lead from the battery, a defective ground connection, a loose battery terminal, or a broken connector. If none of these conditions are present, it is safe to say that the battery is no longer capable of delivering current. While magneto ignition is generally used on airplane engines, there is apt to be some development of battery ignition, especially on engines equipped with electric self-starters which are now being experimented with. The spark-plugs may be short circuited by cracked insulation or carbon and oil deposits around the electrode. The secondary wires may be broken or have defective insulation which permits the current to ground to some metal part of the fuselage or motor. The electrodes of the spark-plug may be too far apart to permit a spark to overcome the resistance of the compressed gas, even if a spark jumps the air space, when the plug is laid on the cylinder. If magnetos are fitted as is usually the case at present and a spark is obtained between the points of the plug and that device or the wire leading to it from the magneto is in proper condition, the trouble is probably caused by the magneto being out of time. This may result if the driving gear is loose on the armature-shaft or crank-shaft, and is a rare occurrence. If no spark is produced at the plugs the secondary wire may be broken, the ground wire may make contact with some metallic portion of the chassis before it reaches the switch, the carbon collecting brushes may be broken or not making contact, the contact points of the make-and-break device may be out of adjustment, the wiring may be attached to wrong terminals, the distributor filled with metallic particles, carbon, dust or oil accumulations, the distributor contacts may not be making proper connection because of wear and there may be a more serious derangement, such as a burned out secondary winding or a punctured condenser. If the motor runs intermittently, _i.e._, starts and runs only a few revolutions, aside from the conditions previously outlined, defective operation may be due to seizing between parts because of insufficient oil or deficient cooling, too much oil in the crank-case which fouls the cylinder after the crank-shaft has revolved a few turns, and derangements in the ignition or carburetion systems that may be easily remedied. There are a number of defective conditions which may exist in the ignition group, that will result in "skipping" or irregular operation and the following points should be considered first: weak source of current due to worn out dry cells or discharged storage batteries; weak magnets in magneto, or defective contacts at magneto; dirt in magneto distributor or poor contact at collecting brushes. Dirty or cracked insulator at spark-plug will cause short circuit and can only be detected by careful examination. The following points should also be checked over when the plug is inspected: Excessive space between electrodes, points too close together, loose central electrodes, or loose point on plug body, soot or oil particles between electrodes, or on the surface of the insulator, cracked insulator, oil or water on outside of insulator. Short circuits in the condenser or internal wiring of induction coils or magnetos, which are fortunately not common, can seldom be remedied except at the factory where these devices were made. If an engine stops suddenly and the defect is in the ignition system the trouble is usually never more serious than a broken or loose wire. This may be easily located by inspecting the wiring at the terminals. Irregular operation or misfiring is harder to locate because the trouble can only be found after the many possible defective conditions have been checked over, one by one. COMMON DEFECTS IN FUEL SYSTEMS Defective carburetion often causes misfiring or irregular operation. The common derangement of the components of the fuel system that are common enough to warrant suspicion and the best methods for their location follows: First, disconnect the feed pipe from the carburetor and see if the gasoline flows freely from the tank. If the stream coming out of the pipe is not the full size of the orifice it is an indication that the pipe is clogged with dirt or that there is an accumulation of rust, scale, or lint in the strainer screens of the filter. It is also possible that the fuel shut-off valve may be wholly or partly closed. If the gasoline flows by gravity the liquid may be air bound in the tank, while if a pressure-feed system is utilized the tank may leak so that it does not retain pressure; the check valve retaining the pressure may be defective or the pipe conveying the air or gas under pressure to the tank may be clogged. If the gasoline flows from the pipe in a steady stream the carburetor demands examination. There may be dirt or water in the float chamber, which will constrict the passage between the float chamber and the spray nozzle, or a particle of foreign matter may have entered the nozzle and stopped up the fine holes therein. The float may bind on its guide, the needle valve regulating the gasoline-inlet opening in bowl may stick to its seat. Any of the conditions mentioned would cut down the gasoline supply and the engine would not receive sufficient quantities of gas. The air-valve spring may be weak or the air valve broken. The gasoline-adjusting needle may be loose and jar out of adjustment, or the air-valve spring-adjusting nuts may be such a poor fit on the stem that adjustments will not be retained. These instructions apply only to carburetors having air valves and mixture regulating means which are used only in rare instances in airplane work. Air may leak in through the manifold, due to a porous casting, or leaky joints in a built up form and dilute the mixture. The air-intake dust screen may be so clogged with dirt and lint that not enough air will pass through the mesh. Water or sediment in the gasoline will cause misfiring because the fuel feed varies when the water or dirt constricts the standpipe bore. It is possible that the carburetor may be out of adjustment. If clouds of black smoke are emitted at the exhaust pipe it is positive indication that too much gasoline is being supplied the mixture and the supply should be cut down by screwing in the needle valve on types where this method of regulation is provided, and by making sure that the fuel level is at the proper height, or that the proper nozzle is used in those forms where the spray nozzle has no means of adjustment. If the mixture contains too much air there will be a pronounced popping back in the carburetor. This may be overcome by screwing in the air-valve adjustment so the spring tension is increased or by slightly opening up the gasoline-supply regulation needle. When a carburetor is properly adjusted and the mixture delivered the cylinder burns properly, the exhaust gas will be clean and free from the objectionable odor present when gasoline is burned in excess. The character of combustion may be judged by the color of the flame which issues from it when the engine is running with an open throttle after nightfall. If the flame is red, it indicates too much gasoline. If yellowish, it shows an excess of air, while a properly proportioned mixture will be evidenced by a pronounced blue flame, such as given by a gas-stove burner. The Duplex Model O. D. Zenith carburetor used upon most of the six- and eight-cylinder airplane engines consists of a single float chamber, and a single air intake, joined to two separate and distinct spray nozzles, venturi and idling adjustments. It is to be noted that as the carburetor barrels are arranged side by side, both valves are mounted on the same shaft, and work in unison through a single operating lever. It is not necessary to alter their position. In order to make the engine idle well, it is essential that the ignition, especially the spark-plugs, should be in good condition. The gaskets between carburetor and manifold, and between manifold and cylinders should be absolutely air-tight. The adjustment for low speed on the carburetor is made by turning in or out the two knurled screws, placed one on each side of the float chamber. After starting the engine and allowing it to become thoroughly warmed, one side of the carburetor should be adjusted so that the three cylinders it affects fire properly at low speed. The other side should be adjusted in the same manner until all six cylinders fire perfectly at low speed. As the adjustment is changed on the knurled screw a difference in the idling of the engine should be noticed. If the engine begins to run evenly or speeds up it shows that the mixture becomes right in its proportion. Be sure the butterfly throttle is closed as far as possible by screwing out the stop screw which regulates the closed position for idling. Care should be taken to have the butterfly held firmly against this stop screw at all times while idling engine. If three cylinders seem to run irregularly after changing the position of the butterfly, still another adjustment may have to be made with the knurled screw. Unscrewing this makes the mixture leaner. Screwing in closes off some of the air supply to the idling jet, making it richer. After one side has been made to idle satisfactorily repeat the same procedure with the opposite three cylinders. In other words, each side should be idled independently to about the same speed. Remember that the main jet and compensating jet have no appreciable effect on the idling of the engine. The idling mixture is drawn directly through the opening determined by the knurled screw and enters the carburetor barrel through the small hole at the edge of each butterfly. This is called the priming hole and is only effective during idling. Beyond that point the suction is transferred to the main jet and compensator, which controls the power of the engine beyond the idling position of the throttle. DEFECTS IN OILING SYSTEMS While troubles existing in the ignition or carburetion groups are usually denoted by imperfect operation of the motor, such as lost power, and misfiring, derangements of the lubrication or cooling systems are usually evident by overheating, diminution in engine capacity, or noisy operation. Overheating may be caused by poor carburetion as much as by deficient cooling or insufficient oiling. When the oiling group is not functioning as it should the friction between the motor parts produces heat. If the cooling system is in proper condition, as will be evidenced by the condition of the water in the radiator, and the carburetion group appears to be in good condition, the overheating is probably caused by some defect in the oiling system. The conditions that most commonly result in poor lubrication are: Insufficient oil in the engine crank-case or sump, broken or clogged oil pipes, screen at filter filled with lint or dirt, broken oil pump, or defective oil-pump drive. The supply of oil may be reduced by a defective inlet or discharge-check valve at the mechanical oiler or worn pumps. A clogged oil passage or pipe leading to an important bearing point will cause trouble because the oil cannot get between the working surfaces. It is well to remember that much of the trouble caused by defective oiling may be prevented by using only the best grades of lubricant, and even if all parts of the oil system are working properly, oils of poor quality will cause friction and overheating. DEFECTS IN COOLING SYSTEMS OUTLINED Cooling systems are very simple and are not liable to give trouble as a rule if the radiator is kept full of clean water and the circulation is not impeded. When overheating is due to defective cooling the most common troubles are those that impede water circulation. If the radiator is clogged or the piping of water jackets filled with rust or sediment the speed of water circulation will be slow, which will also be the case if the water pump or its driving means fail. Any scale or sediment in the water jackets or in the piping or radiator passages will reduce the heat conductivity of the metal exposed to the air, and the water will not be cooled as quickly as though the scale was not present. The rubber hose often used in making the flexible connections demanded between the radiator and water manifolds of the engine may deteriorate inside and particles of rubber hang down that will reduce the area of the passage. The grease from the grease cups mounted on the pump-shaft bearing to lubricate that member often finds its way into the water system and rots the inner walls of the rubber hose, this resulting in strips of the partly decomposed rubber lining hanging down and restricting the passage. The cooling system is prone to overheat after antifreezing solutions of which calcium chloride forms a part have been used. This is due to the formation of crystals of salt in the radiator passages or water jackets, and these crystals can only be dissolved by suitable chemical means, or removed by scraping when the construction permits. Overheating is often caused by some condition in the fuel system that produces too rich or too lean mixture. Excess gasoline may be supplied if any of the following conditions are present: Bore of spray nozzle or standpipe too large, auxiliary air-valve spring too tight, gasoline level too high, loose regulating valve, fuel-soaked cork float, punctured sheet-metal float, dirt under float control shut-off valve or insufficient air supply because of a clogged air screen. If pressure feed is utilized there may be too much pressure in the tank, or the float controlled mechanism operating the shut-off in the float bowl of the carburetor may not act quickly enough. SOME CAUSES OF NOISY OPERATION There are a number of power-plant derangements which give positive indication because of noisy operation. Any knocking or rattling sounds are usually produced by wear in connecting rods or main bearings of the engine, though sometimes a sharp metallic knock, which is very much the same as that produced by a loose bearing, is due to carbon deposits in the cylinder heads, or premature ignition due to advanced spark-time lever. Squeaking sounds invariably indicate dry bearings, and whenever such a sound is heard it should be immediately located and oil applied to the parts thus denoting their dry condition. Whistling or blowing sounds are produced by leaks, either in the engine itself or in the gas manifolds. A sharp whistle denotes the escape of gas under pressure and is usually caused by a defective packing or gasket that seals a portion of the combustion chamber or that is used for a joint as the exhaust manifold. A blowing sound indicates a leaky packing in crank-case. Grinding noises in the motor are usually caused by the timing gears and will obtain if these gears are dry or if they have become worn. Whenever a loud knocking sound is heard careful inspection should be made to locate the cause of the trouble. Much harm may be done in a few minutes if the engine is run with loose connecting rod or bearings that would be prevented by taking up the wear or looseness between the parts by some means of adjustment. BRIEF SUMMARY OF HINTS FOR STARTING ENGINE First make sure that all cylinders have compression. To ascertain this, open pet cocks of all cylinders except the one to be tested, crank over motor and see that a strong opposition to cranking is met with once in two revolutions. If motor has no pet cocks, crank and notice that oppositions are met at equal distances, two to every revolution of the starting crank in a four-cylinder motor. If compression is lacking, examine the parts of the cylinder or cylinders at fault in the following order, trying to start the motor whenever any one fault is found and remedied. See that the valve push rods or rocker arms do not touch valve stems for more than approximately 1/2 revolution in every 2 revolutions, and that there is not more than .010 to .020 inch clearance between them depending on the make of the motor. Make sure that the exhaust valve seats. To determine this examine the spring and see that it is connected to the valve stem properly. Take out valve and see that there is no obstruction, such as carbon, on its seat. See that valve works freely in its guide. Examine inlet valve in same manner. Listen for hissing sound while cranking motor for leaks at other places. Make sure that a spark occurs in each cylinder as follows: If magneto or magneto and battery with non-vibrating coil is used: Disconnect wire from spark-plug, hold end about 1/8 inch from cylinder or terminal of spark-plug. Have motor cranked briskly and see if spark occurs. Examine adjustment of interrupter points. See that wires are placed correctly and not short circuited. Take out spark-plug and lay it on the cylinder, being careful that base of plug only touches the cylinder and that ignition wire is connected. Have motor cranked briskly and see if spark occurs. Check timing of magneto and see that all brushes are making contact. See if there is gasoline in the carburetor. See that there is gasoline in the tank. Examine valve at tank. Prime carburetor and see that spray nozzle passage is clear. Be sure throttle is open. Prime cylinders by putting about a teaspoonful of gasoline in through pet cock or spark-plug opening. Adjust carburetor if necessary. LOCATION OF ENGINE TROUBLES MADE EASY The following tabulation has been prepared and originated by the writer to outline in a simple manner the various troubles and derangements that interfere with efficient internal-combustion engine action. The parts and their functions are practically the same in all gas or gasoline engines of the four-cycle type, and the general instructions given apply just as well to all hydro-carbon engines, even if the parts differ in form materially. The essential components are clearly indicated in the many part sectional drawings in this book so they may be easily recognized. The various defects that may materialize are tabulated in a manner that makes for ready reference, and the various defective conditions are found opposite the part affected, and under a heading that denotes the main trouble to which the others are contributing causes. The various symptoms denoting the individual troubles outlined are given to facilitate their recognition in a positive manner. Brief note is also made of the remedies for the restoration of the defective part or condition. It is apparent that a table of this character is intended merely as a guide, and it is a compilation of practically all the known troubles that may materialize in gas-engine operation. While most of the defects outlined are common enough to warrant suspicion, they will never exist in an engine all at the same time, and it will be necessary to make a systematic search for such of those as exist. To use the list advantageously, it is necessary to know one main trouble easily recognized. For example, if the power plant is noisy, look for the possible troubles under the head of Noisy Operation; if it lacks capacity, the derangement will undoubtedly be found under the head of Lost Power. It is assumed in all cases that the trouble exists in the power plant or its components, and not in the auxiliary members of the ignition, carburetion, lubrication, or cooling systems. The novice and student will readily recognize the parts of the average aviation engine by referring to the very complete and clearly lettered illustrations of mechanism given in many parts of this treatise. LOST POWER AND OVERHEATING ------------------+------------------+------------------+-------------------- PART AFFECTED |NATURE OF TROUBLE | SYMPTOMS AND | REMEDY | | EFFECTS | ------------------+------------------+------------------+-------------------- Water Pipe Joint. |Loose. |Loss of water, |Tighten bolts, | |heating. |replace gaskets. | | | Spark Plug. |Leakage in |Loss of power. |Replace insulation |threads, |Hissing caused by |if defective, screw |insulation, |escaping gas. |down tighter. |packing. | | | | | Compression |Leak in threads. |Loss of power. |Tighten if loose. Release Cock. |Leak in fitting. |Whistling or |Grind fitting to | |hissing. |new seating in | | |body. | | | Combustion |Crack or blowhole.|Loss of compres- |Fill by welding. Chamber. |Roughness. Carbon |sion. Preignition.|Smooth out |deposits. Sharp | |roughness. Scrape |edges. | |out or dissolve | | |carbon. | | | Valve Chamber Cap.|Leak in threads. |Loss of compres- |Remove. Apply pipe |Defective gasket. |sion. Hissing. |compound to threads | | |and replace. Use | | |new gasket or | | |packing. | | | Valve Head. |Warped. Scored or |Loss of compres- |True up in lathe. |pitted. Carbon- |sion. |Grind to seat. |ized. Covered with| |Scrape off. Smooth |scale. Loose on | |with emery cloth. |stem (two-piece | |Tighten by |valves only). | |riveting. | | | Valve Seat. |Warped or pitted. |Loss of compres- |Use reseating |Covered with car- |sion. |reamer. Clean off |bon. Foreign mat- | |and grind valve to |ter between valve | |seat. |and seat. | | | | | Valve Stem. |Covered with |Valve does not |Clean with emery |scale. Bent. Bind-|close. Loss of |cloth; straighten. |ing in guide. |compression. |True up and smooth |Stuck in guide. | |off. free with | | |kerosene. | | | Valve Stem Guide. |Burnt or rough. |Valve may stick. |Clean out hole. |Loose in valve |Action irregular. |Screw in tighter. |chamber. | | | | | Valve Spring. |Weak or broken. |Valve does not | | |close. | | | | Valve Operating |Loose in guide. |Valve action poor.|Replace with new. Plunger. |Too much clearance|Lift insufficient.|Adjust screw closer. |between valve | | |stem. | | | | | Valve Lift Ad- |Threads stripped. |Poor valve action.|Replace with new. justing Screw. |Too near valve. | |Adjust with proper |Too far from | |reference to valve |valve. | |stem. | | | Valve Lift Cam. |Worn cam contour. |Not enough valve |Replace with new. |Loose on shaft. |lift. Will not |Replace pins or |Out of time. |lift valve. Valve |keys. Set to open | |opens at wrong |properly. | |time. | | | | Cam-shaft. |Sprung or twisted.|Valves out of |Straighten. | |time. | | | | Cam-shaft Bushing.|Worn. |Not enough valve |Replace. | |lift. | | | | Cam-shaft Drive |Loose on shaft. |Irregular valve |Fasten securely. Gear. |Out of time. Worn |action. |Time properly. |or broken teeth. | |Replace with new. | | | Cam Fastenings. |Worn or broken. |Valves out of |Replace with new. | |time. | | | | Cylinder Wall. |Scored, gas leaks.|Poor compression. |Grind out bore. |Poor lubrication |Overheating. |Repair oiling |causes friction. | |system. | | | Piston. |Binds in cylinder.|Overheating. Poor |Lap off excess |Walls scored. Worn|compression. |metal. Replace with |out of round. | |new. | | | Piston Rings. |Loss of spring. |Loss of compres- |Peen ring or |Loose in grooves. |sion. Gas blows |replace. Fit new |Scored. Worn or |by. |rings. Grind smooth. |broken. Slots in | |Replace. Turn slots |line. | |apart. | | | |Carbon in grooves.|Overheating be- |Remove deposits. |Insufficient open-|cause of friction.|File slot. Grind or |ing. Binding on | |lap to fit cylinder |cylinder. | |bore. | | | Wristpin. |Loose, scores |Loss of compres- |Fasten securely. |cylinder. |sion. |Replace cylinder if | | |groove is deep. | | | Crank-shaft. |Scored or rough on|Overheating be- |Smooth up. |journals. Sprung. |cause of friction.|Straighten. | | | Crank Bearings. |Adjusted too |Overheating be- |Adjust freely, clean Main Bearings. |tight. Defective |cause of friction.|out oil holes and |oiling. Brasses | |enlarge oil grooves. |burned. | | | | | Oil Sump. |Insufficient oil. |Overheating. |Replenish supply. |Poor lubricant. | |Use best oil. Wash |Dirty oil. | |out with kerosene; | | |put in clean oil. | | | Water Space. Water|Clogged with sedi-|Overheating. |Dissolve foreign Pipes. |ment or scale. | |matter and remove. | | | Piston Head. |Cracked (rare). |Loss of compres- |Weld by autogenous |Carbon deposits. |sion. Preignition.|process. Scrape off | | |carbon accumula- | | |tions. ------------------+------------------+------------------+-------------------- NOISY OPERATION OF POWER PLANT ------------------+------------------+------------------+-------------------- PART AFFECTED |NATURE OF TROUBLE | CHARACTER OF | REMEDY | | NOISE | ------------------+------------------+------------------+-------------------- Compression Re- |Leakage. |Hissing. |Previously given. lease Cock. | | | | | | Spark Plug. |Leakage. |Hissing. |Previously given. | | | Valve Chamber Cap.|Leakage. |Hiss or whistle. |Previously given. | | | Combustion |Carbon deposits. |Knocking. |Previously given. Chamber. | | | | | | Inlet Valve Seat. |Defects previously|Popping in carbu- |Previously given. |given. |retor. | | | | Valve Head. |Loose on stem. |Clicking. |Previously given. | | | Valve Stem. Valve |Wear or looseness.|Rattle or click- |Previously given. Stem Guide. | |ing. | | | | Inlet Valve. |Closes too late. |Blowback in carbu-|Previously given. |Opens too early. |retor. | | | | Valve Spring. |Weak or broken. |Blowback in carbu-|Previously given. | |retor. | | | | Cylinder Casting. |Retaining bolts |Sharp metallic |Tighten bolts. Round |loose. Piston |knock. |edges of piston |strikes at upper | |top. |end. | | | | | Cylinder Wall. |Scored. |Hissing. |Previously given. | | | Valve Stem |Too much. |Clicking. Blowback|Previously given. Clearance. |Too little (inlet |in carburetor. | |valve). | | | | | Valve Operating |Looseness. |Rattle or click- |Previously given. Plunger. Plunger | |ing. | Guide. | | | | | | Timing Gears. |Loose on fasten- |Metallic knock. |Previously given. |ings. Worn teeth. |Rattle. Grinding. | | | | Cylinder or |No oil, or poor |Grinding. |Repair oil system. Piston. |lubricant. | | | | | Cam. |Loose on shaft. |Metallic knock. |Previously given. |Worn contour. | | | | | Cam-shaft Bearing.|Looseness or wear.|Slight knock. |Previously given. | | | Cam Fastening. |Looseness. |Clicking. |Previously given. | | | Piston. |Binding in cylin- |Grinding or dull |Previously given. |der. Worn oval, |squeak. Dull | |causes side slap |hammering. | |in cylinder. | | | | | Piston Head. |Carbon deposits. |Knocking. |Previously given. | | | Piston Rings. |Defective oiling. |Squeaking. Hiss- |Previously given. |Leakage. Binding |ing. Grinding. | |in cylinder. | | | | | Wrist-pin. |Loose in piston. |Dull metallic |Replace with new |Worn. |knock. |member. | | | Connecting Rod. |Wear in upper |Distinct knock. |Adjust or replace. |bushing. Wear at | |Scrape and fit. Use |crank-pin. Side | |longer wrist-pin |play in piston. | |bushing. | | | Crank Bearings. |Looseness. Exces- |Metallic knock. |Refit bearings. |sive end play. |Intermittent |Longer bushings |Binding, fitted |knock. Squeaking. |needed. Insert shims |too tight. | |to allow more play. | | | Main Bearings. |Looseness. Defec- |Metallic knock. |Fit brasses closer |tive lubrication. |Squeaking. |to shaft. Clean out | | |oil holes and | | |grooves. | | | Connecting Rod |Loose. |Sharp knock. |Tighten. Bolts. Main | | | Bearing Bolts. | | | | | | Crank-shaft. |Defective oiling. |Squeaking. |Previously given. | | | Engine Base. |Loose on frame. |Sharp pounding. |Tighten bolts. | | | Lower Half Crank- |Bolts loose. |Knocking. |Tighten bolts. case. | | | | | | Fly-wheel. |Loose on crank- |Very sharp knock. |Tighten retention |shaft. | |bolts or fit new | | |keys. | | | Oil Sump. |Oil level too low.|Grinding and |Replenish with best |Poor lubricant. |squeak in all |cylinder oil. | |bearings. | | | | Valve Plunger Re- |Looseness. |Clicking. |Tighten nuts. tention Stirrups. | | | | | | Fan. |Blade loose. Blade|Clicking or |Tighten. Bend back. |strikes cooler. |rattle. | | | | Exhaust Pipe |Leakage. |Sharp hissing. |Tighten or use new Joints. | | |gasket. | | | Crank-case |Leakage. |Blowing sound. |Use new packing. Packing. | | |Tighten bolts. | | | Water Pipe. |Leaks. Loss of |Pounding because |Previously given. |water. Clogged |engine heats. | |with sediment. | | | | | Water Jacket. |Clogged with sedi-|Knocking because |Dissolve scale and |ment. Walls |engine heats. |flush out water |covered with | |space with water |scale. | |under pressure. --------------------+------------------+------------------+-------------------- "SKIPPING" OR IRREGULAR OPERATION ------------------+------------------+------------------+-------------------- PART AFFECTED |NATURE OF TROUBLE | SYMPTOMS AND | REMEDY | | EFFECTS | ------------------+------------------+------------------+-------------------- Compression Relief|Leak in threads or|Dilutes mixture |Screw down tighter. Cock. |spigot. |with air, causes |Grind spigot to seat | |blowback. |with emery. | | | Spark-Plug. |Leak in threads. |Dilutes mixture. |Screw down tighter. |Defective gasket. |Allows short |Replace with new. |Cracked insulator.|circuit. No spark.|Set points 1/64" |Points too near. | |apart for magneto, |Points covered | |1/32" for battery |with carbon. Too | |spark. |much air gap. | | | | | Valve Chamber Cap.|Leak in threads. |Dilutes mixture by|Previously given. |Defective gasket. |allowing air to | | |enter cylinder on | | |suction stroke. | | | | Combustion |Carbon deposits. |Preignition. |Scrape out. Chamber. | | | | | | Valve Head. |Warped or pitted. |Dilutes charge |Previously given. |Loose on stem. |with poor air or | | |gas. | | | | Valve Stem. |Binding in guide. |Irregular valve |Previously given. |Sticking. |action. | | | | Valve Seat. |Scored or warped. |Gas leak, poor |Previously given. |Cracked. Covered |mixture. Poor com-| |with scale. Dirt |pression. Valve | |under valve. |will not close. | | | | Induction Pipe. |Leak at joints. |Mixture diluted |Stop all leaks. |Crack or blowhole.|with excess air. | | | | Inlet Valve. |Closes too late. |Blowback in carbu-|Time properly. |Opens too early. |retor. | | | | Exhaust Valve. |Opens too late. |Retention of burnt|Time properly. |Closes too early. |gas dilutes | | |charge. | | | | Valve Stem Guide. |Bent or carbon- |Causes valve to |Previously given. |ized. |stick. | | | | Inlet Valve Stem |Worn, stem loose. |Air drawn in on |Bush guide or use Guide. | |suction thins gas.|new member. | | | Valve Spring. |Weakened or |Irregular action. |Use new spring. |broken. | | | | | Valve Stem |Too little. Too |Valve will not |Adjust gap .009" Clearance. |much. |shut. Valve opens |inlet, .010" | |late, closes |exhaust. | |early. | Valve Spring |Broken. |Releases spring. |Replace. Collar Key. | | | | | | Cam. |Worn cam contour. |Valve lift re- |Previously given. |Loose on shaft. |duced. Does not | |Out of time. |lift valve. Valves| | |operate at wrong | | |time. | | | | Cam-shaft Bearing.|Looseness or wear.|Valve timing |Replace. | |altered. Valve | | |lift decreased. | | | | Cam-shaft. |Twisted. |Valves out of |Previously given. | |time. | | | | Cam Fastening. |Worn or broken. |Valve action |Replace with new. | |irregular. | | | | Valve Operating |Loose in guide. |Alters valve |Replace with new. Plunger. | |timing. | | | | Valve Plunger |Wear in bore. |Alters valve |Replace or bush. Guide. |Loose on engine |timing. |Fasten securely. |base. | | | | | Timing Gears. |Not properly |Valves out of |Retime properly. |meshed. Loose on |time. Valves do |Fasten to shaft. |shaft. |not operate. | | | | Piston. |Walls scored. |Leakage of gas. |Smooth up if | | |possible. | | | Piston Head. |Carbon deposits. |Cause premature |Previously given. |Crack or blowhole |ignition. | |(rare). | | | | | Piston Rings. |No spring. Loose |Leakage weakens |Previously given. |in grooves. Worn |suction. | |or broken. | | | | | Cylinder Wall. |Scored by wrist- |Gas leaks by. Poor|Previously given. |pin. Scored by |suction. | |lack of oil. | | ------------------+------------------+------------------+-------------------- IGNITION SYSTEM TROUBLES ONLY _Motor Will Not Start or Starts Hard_ Loose Battery Terminal. Magneto Ground Wire Shorted. Magneto Defective (No Spark at Plugs). Broken Spark Plug Insulation. Carbon Deposits or Oil Between Plug Points. Spark-Plug Points Too Near Together or Far Apart. Wrong Cables to Plugs. Short Circuited Secondary Cable. Broken Secondary Cable. Dry Battery Weak. } Storage Battery Discharged. } Battery Systems Poor Contact at Timer. } Only. Timer Points Dirty. } Poor Contact at Switch. } Primary Wires Broken, or Short Circuited. } Battery and Battery Grounded in Metal Container. } Coil Ignition Battery Connectors Broken or Loose. } System Only. Timer Points Out of Adjustment. } Defects in Induction Coil. } Ignition Timing Wrong, Spark Too Late or Too Early. Defective Platinum Points in Breaker Box (Magneto). Points Not Separating. Broken Contact Maker Spring. No Contact at Secondary Collector Brush. Platinum Contact Points Burnt or Pitted. Contact Breaker Bell Crank Stuck. Fiber Bushing in Bell Crank Swollen. Short Circuiting Spring Always in Contact. Dirt or Water in Magneto Casing. Oil in Contact Breaker. Oil Soaked Brush and Collector Ring. Distributor Filled with Carbon Particles. _Motor Stops Without Warning_ Broken Magneto Carbon Brush. Broken Lead Wire. Broken Ground Wire. Battery Ignition Systems. Water on High Tension Magneto Terminal. Main Secondary Cable Burnt Through by Hot Exhaust Pipe (Transformer Coil, Magneto Systems). Particle of Carbon Between Spark Plug Points. Magneto Short Circuited by Ground Wire. Magneto Out of Time, Due to Slipping Drive. Water or Oil in Safety Spark Gap (Multi-cylinder Magneto). Magneto Contact Breaker or Timer Stuck in Retard Position. Worn Fiber Block in Magneto Contact Breaker. Binding Fiber Bushing in Contact Breaker Bell Crank. Spark Advance Rod or Wire Broken. Contact Breaker Parts Stuck. _Motor Runs Irregularly or Misfires_ Loose Wiring or Terminals. Broken Spark-Plug Insulator. Spark-Plug Points Sooted or Oily. Wrong Spark Gap at Plug Points. Leaking Secondary Cable. Prematurely Grounded Primary Wire. Batteries Running Down (Battery Ignition only). Poor Adjustment of Contact Points at Timer. Wire Broken Inside of Insulation. Loose Platinum Points in Magneto. Weak Contact Spring. Broken Collector Brush. Dirt in Magneto Distributor Casing or Contact Breaker. Worn Fiber Block or Cam Plate in Magneto. Worn Cam or Contact Roll in Timer (Battery System only). Dirty Oil in Timer. Sticking Coil Vibrators. Coil Vibrator Points Pitted. Oil Soaked Magneto Winding. Punctured Magneto or Coil Winding. Distributor Contact Segments Rough. Sulphated Storage Battery Terminals. Weak Magnets in Magneto. Poor Contact at Magneto Contact Breaker Points. DEFECTS IN ELECTRICAL SYSTEM COMPONENTS To further simplify the location of electrical system faults it is thought desirable to outline the defects that can be present in the various parts of the individual devices comprising the ignition system. If an airplane engine is provided with magneto ignition solely, as most engines are at the present time, no attention need be paid to such items as storage or dry batteries, timer or induction coil. There seems to be some development in the direction of battery ignition so it has been considered desirable to include components of these systems as well as the almost universally used magneto group. Spark-plugs, wiring and switches are needed with either system. SPARK-PLUGS DEFECT TROUBLE CAUSED REMEDY Insulation cracked. Plug inoperative. New insulation. Insulation oil soaked. Cylinder misfires. Clean. Carbon deposits. Short circuited spark. Remove. Insulator loose. Cylinder misfires. Tighten. Gasket broken. Gas leaks by. New gasket. Electrode loose on shell. Cylinder misfires. Tighten. Wire loose in insulator. Cylinder misfires. Tighten. Air gap too close. Short circuits spark. Set correctly. Air gap too wide. Spark will not jump. Set points 1/32" apart. Loose terminal. Cylinder may misfire. Tighten. Plug loose in cylinder. Gas leaks. Tighten. Mica insulation oil soaked. Short circuits spark. Replace. MAGNETO DEFECT TROUBLE CAUSED REMEDY Dirty oil in distributor. Engine misfires. Clean. Metal dust in distributor. Engine misfires. Clean. Brushes not making contact. Current cannot pass. Strengthen spring. Distributor segments worn. Engine misfires. Secure even bearing. Collecting brush broken. Engine misfires. New brush. Distributing brush broken. Engine misfires. New brush. Oil soaked winding. Engine misfires. Clean. Magnets loose on pole Engine misfires. Tighten screws. pieces. Armature rubs. Engine misfires. Repair bearings. Bearings worn. Noisy. Replace. Magnets weak. Weak spark. Recharge. Contact breaker points Engine misfires. Clean. pitted. Breaker points out of Engine misfires. Reset. adjustment. Defective winding (rare). No spark. Replace. Punctured condenser (rare). Weak or no spark. Replace. Driving gear loose. Noise. Tighten. Magneto armature out of Spark will not fire Retime. time. charge. Magneto loose on base. Misfiring and noisy. Tighten. Contact breaker cam worn. Misfiring. Replace. Fibre shoe or rolls worn Misfiring. Replace. (Bosch). Fibre bushing binding in Misfiring. Ream slightly. contact lever (Bosch). Contact lever return spring No spark. Replace. broken. Contact lever return spring Misfiring. Replace. weak. Ground wire grounded. No spark. Insulate. Ground wire broken. Engine will not stop. Connect up. Safety spark gap dirty. No spark. Clean. Fused metal in spark gap. No spark. Remove. Safety spark gap points too Misfiring. Set properly. close. Loose distributor terminals. Misfiring. Tighten. Contact breaker sticks. No spark control. Remove and clean bearings. Magneto switch short- No spark. Insulate. circuited. Magneto switch open circuit. No engine stop. Restore contact. STORAGE BATTERY DEFECT TROUBLE CAUSED REMEDY Electrolyte low. Weak current. Replenish with distilled water. Loose terminals. Misfiring. Tighten. Sulphated terminals. Misfiring. Clean thoroughly and coat with vaseline. Battery discharged. Misfiring or no spark. New charge. Electrolyte weak. Weak current. Bring to proper specific gravity. Plates sulphated. Poor capacity. Special slow charge. Sediment or mud in bottom. Weak current. Clean out. Active material loose in Poor capacity. New plates. grids. Moisture or acid on top of Shorts terminals. Remove. cells. Plugged vent cap. Buckles cell jars. Make vent hole. Cracked vent cap. Acid spills out. New cap. Cracked cell jar. Electrolyte runs out. New jar. DRY CELL BATTERY DEFECT TROUBLE CAUSED REMEDY Broken wires. No current. New wires. Loose terminals. Misfiring. Tighten. Weak cell (7 amperes or Misfiring. New cells. less). Cells in contact. Short circuit. Separate and insulate. Water in battery box. Short circuit. Dry out. TIMER DEFECT TROUBLE CAUSED REMEDY Contact segments worn or Misfiring. Grind down pitted. smooth. Platinum points pitted. Misfiring. Smooth with oil stone. Dirty oil or metal dust in Misfiring. Clean out. interior. Worn bearing. Misfiring. Replace. Loose terminals. Misfiring. Tighten. Worn revolving contact Misfiring. Replace. brush. Out of time. Irregular spark. Reset. INDUCTION COIL DEFECT TROUBLE CAUSED REMEDY Loose terminals. Misfiring. Tighten. Broken connections. No spark. Make new joints. Vibrators out of adjustment. Misfiring. Readjust. Vibrator points pitted. Misfiring. Clean. Defective condenser } rare. No spark. Send to maker Defective winding } for repairs. Poor contact at switch. Misfiring. Tighten. Broken internal wiring. No spark. Replace. Poor coil unit. One cylinder affected. Replace. WIRING DEFECT TROUBLE CAUSED REMEDY Loose terminals anywhere. Misfiring. Tighten. Broken plug wire. One cylinder will not Replace. fire. Broken timer wire. One coil will not buzz. Replace. Broken main battery wire. } No spark. Replace. Broken battery ground wire.} Broken magneto ground wire. Engine will not stop. Replace. Chafed insulation anywhere.} Misfiring. Insulate. Short circuit anywhere. } CARBURETION SYSTEM FAULTS SUMMARIZED _Motor Starts Hard or Will Not Start_ No Gasoline in Tank. No Gasoline in Carburetor Float Chamber. Tank Shut-Off Closed. Clogged Filter Screen. Fuel Supply Pipe Clogged. Gasoline Level Too Low. Gasoline Level Too High (Flooding). Bent or Stuck Float Lever. Loose or Defective Inlet Manifold. Not Enough Gasoline at Jet. Cylinders Flooded with Gas. Fuel Soaked Cork Float (Causes Flooding). Water in Carburetor Spray Nozzle. Dirt in Float Chamber. Gas Mixture Too Lean. Carburetor Frozen (Winter Only). _Motor Stops In Flight_ Gasoline Shut-Off Valve Jarred Closed. Gasoline Supply Pipe Clogged. No Gasoline in Tank. Spray Nozzle Stopped Up. Water in Spray Nozzle. Particles of Carbon Between Spark-Plug Points. Magneto Short Circuited by Ground in Wire. Air Lock in Gasoline Pipe. Broken Air Line or Leaky Tank (Pressure Feed System Only). Fuel Supply Pipe Partially Clogged. Air Vent in Tank Filler Cap Stopped Up (Gravity and Vacuum Feed System). Float Needle Valve Stuck. Water or Dirt in Spray Nozzle. Mixture Adjusting Needle Jarred Loose (Rotary Motors Only). _Motor Races, Will Not Throttle Down_ Air Leak in Inlet Piping. Air Leak Through Inlet Valve Guides. Control Rods Broken. Defective Induction Pipe Joints. Leaky Carburetor Flange Packing. Throttle Not Closing. Poor Slow Speed Adjustment (Zenith Carburetor). _Motor Misfires_ Carburetor Float Chamber Getting Dry. Water or Dirt in Gasoline. Poor Gasoline Adjustment (Rotary Motors). Not Enough Gasoline in Float Chamber. Too Much Gasoline, Carburetor Flooding. Incorrect Jet or Choke (Zenith Carburetor). Broken Cylinder Head Packing Between Cylinders. _Noisy Operation_ Popping or Blowing Back in Carburetor. Incorrectly Timed Inlet Valves. Inlet Valve Not Seating. Defective Inlet Valve Spring. Dirt Under Inlet Valve Seat. Not Enough Gasoline (Open Needle Valve). Muffler or Manifold Explosions. Mixture Not Exploding Regularly. Exhaust Valve Sticking. Dirt Under Exhaust Valve Seat. CHAPTER XI Tools for Adjusting and Erecting--Forms of Wrenches--Use and Care of Files--Split Pin Removal and Installation--Complete Chisel Set--Drilling Machines--Drills, Reamers, Taps and Dies-- Measuring Tools--Micrometer Calipers and Their Use--Typical Tool Outfits--Special Hall-Scott Tools--Overhauling Airplane Engines --Taking Engine Down--Defects in Cylinders--Carbon Deposits, Cause and Prevention--Use of Carbon Scrapers--Burning Out Carbon with Oxygen--Repairing Scored Cylinders--Valve Removal and Inspection--Reseating and Truing Valves--Valve Grinding Processes--Depreciation in Valve Operating System--Piston Troubles--Piston Ring Manipulation--Fitting Piston Rings-- Wrist-Pin Wear--Inspection and Refitting of Engine Bearings-- Scraping Brasses to Fit--Fitting Connecting Rods--Testing for Bearing Parallelism--Cam-Shafts and Timing Gears--Precautions in Reassembling Parts. TOOLS FOR ADJUSTING AND ERECTING [Illustration: Fig. 163.--Practical Hand Tools Useful in Dismantling and Repairing Airplane Engines.] A very complete outfit of small tools, some of which are furnished as part of the tool equipment of various engines are shown in group at Fig. 163. This group includes all of the tools necessary to complete a very practical kit and it is not unusual for the mechanic who is continually dismantling and erecting engines to possess even a larger assortment than indicated. The small bench vise provided is a useful auxiliary that can be clamped to any convenient bench or table or even fuselage longeron in an emergency and should have jaws at least three inches wide and capable of opening four or five inches. It is especially useful in that it will save trips to the bench vises, as it has adequate capacity to handle practically any of the small parts that need to be worked on when making repairs. A blow torch, tinner's snips and soldering copper are very useful in sheet metal work and in making any repairs requiring the use of solder. The torch can be used in any operation requiring a source of heat. The large box wrench shown under the vise is used for removing large special nuts and sometimes has one end of the proper size to fit the valve chamber cap. The piston ring removers are easily made from thin strips of sheet metal securely brazed or soldered to a light wire handle. These are used in sets of three for removing and applying piston rings in a manner to be indicated. The uses of the wrenches, screw drivers, and pliers shown are known to all and the variety outlined should be sufficient for all ordinary work of restoration. The wrench equipment is very complete, including a set of open end S-wrenches to fit all standard bolts, a spanner wrench, socket or box wrenches for bolts that are inaccessible with the ordinary type, adjustable end wrenches, a thin monkey wrench of medium size, a bicycle wrench for handling small nuts and bolts, a Stillson wrench for pipe and a large adjustable monkey wrench for the stubborn fastenings of large size. Four different types of pliers are shown, one being a parallel jaw type with size cutting attachment, while the other illustrated near it is a combination parallel jaw type adapted for use on round work as well as in handling flat stock. The most popular form of pliers is the combination pattern shown beneath the socket wrench set. This is made of substantial drop forgings having a hinged joint that can be set so that a very wide opening at the jaws is possible. These can be used on round work and for wire cutting as well as for handling flat work. Round nose pliers are very useful also. A very complete set of files, including square, half round, mill, flat bastard, three-cornered and rat tail are also necessary. A hacksaw frame and a number of saws, some with fine teeth for tubing and others with coarser teeth for bar or solid stock will be found almost indispensable. A complete punch and chisel set should be provided, samples of which are shown in the group while the complete outfit is outlined in another illustration. A number of different forms and sizes of chisels are necessary, as one type is not suitable for all classes of work. The adjustable end wrenches can be used in many places where a monkey wrench cannot be fitted and where it will be difficult to use a wrench having a fixed opening. The Stillson pipe wrench is useful in turning studs, round rods, and pipes that cannot be turned by any other means. A complete shop kit must necessarily include various sizes for Stillson and monkey wrenches, as no one size can be expected to handle the wide range of work the engine repairman must cope with. Three sizes of each form of wrench can be used, one, a 6 inch, is as small as is needed while, a 12 inch tool will handle almost any piece of pipe or nut used in engine construction. Three or four sizes of hammers should be provided, according to individual requirement, these being small riveting, medium and heavyweight machinist's hammers. A very practical tool of this nature for the repair shop can be used as a hammer, screw driver or pry iron. It is known as the "Spartan" hammer and is a tool steel drop forging in one piece having the working surfaces properly hardened and tempered while the metal is distributed so as to give a good balance to the head and a comfortable grip to the handle. The hammer head provides a positive and comfortable T-handle when the tool is used as a screw driver or "tommy" bar. Machinist's hammers are provided with three types of heads, these being of various weights. The form most commonly used is termed the "ball pein" on account of the shape of the portion used for riveting. The straight pein is just the same as the cross pein, except that in the latter the straight portion is at right angles to the hammer handle, while in the former it is parallel to that member. FORMS OF WRENCHES Wrenches have been made in infinite variety and there are a score or more patterns of different types of adjustable socket and off-set wrenches. The various wrench types that differ from the more conventional monkey wrenches or those of the Stillson pattern are shown at Fig. 164. The "perfect handle" is a drop forged open end form provided with a wooden handle similar to that used on a monkey wrench in order to provide a better grip for the hand. The "Saxon" wrench is a double alligator form, so called because the jaws are in the form of a V-groove having one side of the V plain, while the other is serrated in order to secure a tight grip on round objects. In the form shown, two jaws of varying sizes are provided, one for large work, the other to handle the smaller rods. One of the novel features in connection with this wrench is the provision of a triple die block in the centre of the handle which is provided with three most commonly used of the standard threads including 5/16-inch-18, 3/8-inch-16, and 1/2-inch-13. This is useful in cleaning up burred threads on bolts before they are replaced, as burring is unavoidable if it has been necessary to drive them out with a hammer. The "Lakeside" wrench has an adjustable pawl engaging with one of a series of notches by which the opening may be held in any desired position. [Illustration: Fig. 164.--Wrenches are Offered in Many Forms.] Ever since the socket wrench was invented it has been a popular form because it can be used in many places where the ordinary open end or monkey wrench cannot be applied owing to lack of room for the head of the wrench. A typical set which has been made to fit in a very small space is shown at D. It consists of a handle, which is nickel-plated and highly polished, a long extension bar, a universal joint and a number of case hardened cold drawn steel sockets to fit all commonly used standard nuts and bolt heads. Two screw-driver bits, one small and the other large to fit the handle, and a long socket to fit spark-plugs are also included in this outfit. The universal joint permits one to remove nuts in a position that would be inaccessible to any other form of wrench, as it enables the socket to be turned even if the handle is at one side of an intervening obstruction. The "Pick-up" wrench, shown at E, is used for spark-plugs and the upper end of the socket is provided with a series of grooves into which a suitable blade carried by the handle can be dropped. The handle is pivoted to the top of the socket in such a way that the blades may be picked up out of the grooves by lifting on the end of the handle and dropped in again when the handle is swung around to the proper point to get another hold on the socket. The "Miller" wrench shown at F, is a combination socket and open end type, made especially for use with spark-plugs. Both the open end and the socket are convenient. The "Handy" set shown at G, consists of a number of thin stamped wrenches of steel held together in a group by a simple clamp fitting, which enables either end of any one of the four double wrenches to be brought into play according to the size of the nut to be turned. The "Cronk" wrench shown at H, is a simple stamping having an alligator opening at one end and a stepped opening capable of handling four different sizes of standard nuts or bolt heads at the other. Such wrenches are very cheap and are worth many times their small cost, especially for fitting nuts where there is not sufficient room to admit the more conventional pattern. The "Starrett" wrench set, which is shown at I, consists of a ratchet handle together with an extension bar and universal joint, a spark-plug socket, a drilling attachment which takes standard square shank drills from 1/8-inch to 1/2-inch in diameter, a double ended screw-driver bit and several adjustments to go with the drilling attachment. Twenty-eight assorted cold drawn steel sockets similar in design to those shown at D, to fit all standard sizes of square and hexagonal headed nuts are also included. The reversible ratchet handle, which may be slipped over the extension bar or the universal joint and which is also adapted to take the squared end of any one of the sockets is exceptionally useful in permitting, as it does, the instant release of pressure when it is desired to swing the handle back to get another hold on the nut. The socket wrench sets are usually supplied in hard wood cases or in leather bags so that they may be kept together and protected against loss or damage. With a properly selected socket wrench set, either of the ratchet handle or T-handle form, any nut on the engine may be reached and end wrenches will not be necessary. USE AND CARE OF FILES Mention has been previously made of the importance of providing a complete set of files and suitable handles. These should be in various grades or degrees of fineness and three of each kind should be provided. In the flat and half round files three grades are necessary, one with coarse teeth for roughing, and others with medium and fine teeth for the finishing cuts. The round or rat tail file is necessary in filing out small holes, the half round for finishing the interior of large ones. Half round files are also well adapted for finishing surfaces of peculiar contour, such as the inside of bearing boxes, connecting rod and main bearing caps, etc. Square files are useful in finishing keyways or cleaning out burred splines, while the triangular section or three-cornered file is of value in cleaning out burred threads and sharp corners. Flat files are used on all plane surfaces. [Illustration: Fig. 165.--Illustrating Use and Care of Files.] The file brush shown at Fig. 165, A, consists of a large number of wire bristles attached to a substantial wood back having a handle of convenient form so that the bristles may be drawn through the interstices between the teeth of the file to remove dirt and grease. If the teeth are filled with pieces of soft metal, such as solder or babbitt, it may be necessary to remove this accumulation with a piece of sheet metal as indicated at Fig. 165, B. The method of holding a file for working on plain surfaces when it is fitted with the regular form of wooden handle is shown at C, while two types of handles enabling the mechanic to use the flat file on plain surfaces of such size that the handle type indicated at C, could not be used on account of interfering with the surface finished are shown at D. The method of using a file when surfaces are finished by draw filing is shown at E. This differs from the usual method of filing and is only used when surfaces are to be polished and very little metal removed. SPLIT PIN REMOVAL AND INSERTION One of the most widely used of the locking means to prevent nuts or bolts from becoming loose is the simple split pin, sometimes called a "cotter pin." These can be handled very easily if the special pliers shown at Fig. 166, A, are used. They have a curved jaw that permits of grasping the pin firmly and inserting it in the hole ready to receive it. It is not easy to insert these split pins by other means because the ends are usually spread out and it is hard to enter the pin in the hole. With the cotter pin pliers the ends may be brought close together and as the plier jaws are small the pin may be easily pushed in place. Another use of this plier, also indicated, is to bend over the ends of the split pin in order to prevent it from falling out. To remove these pins a simple curved lever, as shown at Fig. 166, B, is used. This has one end tapering to a point and is intended to be inserted in the eye of the cotter pin, the purchase offered by the handle permitting of ready removal of the pin after the ends have been closed by the cotter pin pliers. COMPLETE CHISEL SET [Illustration: Fig. 166.--Outlining Use of Cotter Pin Pliers, Spring Winder, and Showing Practical Outfit of Chisels.] A complete chisel set suitable for repair shop use is also shown at Fig. 166. The type at C is known as a "cape" chisel and has a narrow cutting point and is intended to chip keyways, remove metal out of corners and for all other work where the broad cutting edge chisel, shown at D, cannot be used. The form with the wide cutting edge is used in chipping, cutting sheet metal, etc. At E, a round nose chisel used in making oil ways is outlined, while a similar tool having a pointed cutting edge and often used for the same purpose is shown at F. The centre punch depicted at G, is very useful for marking parts either for identification or for drilling. In addition to the chisels shown, a number of solid punches or drifts resembling very much that shown at E, except that the point is blunt should be provided to drive out taper pins, bolts, rivets, and other fastenings of this nature. These should be provided in the common sizes. A complete set of real value would start at 1/8-inch and increase by increments of 1/32-inch up to 1/2-inch. A simple spring winder is shown at Fig. 166, H, this making it possible for the repairman to wind coil springs, either on the lathe or in the vise. It will handle a number of different sizes of wire and can be set to space the coils as desired. DRILLING MACHINES [Illustration: Fig. 167.--Forms of Hand Operated Drilling Machines.] Drilling machines may be of two kinds, hand or power operated. For drilling small holes in metal it is necessary to run the drill fast, therefore the drill chuck is usually driven by gearing in order to produce high drill speed without turning the handle too fast. A small hand drill is shown at Fig. 167, A. As will be observed, the chuck spindle is driven by a small bevel pinion, which in turn, is operated by a large bevel gear turned by a crank. The gear ratio is such that one turn of the handle will turn the chuck five or six revolutions. A drill of this design is not suited for drills any larger than one-quarter inch. For use with drills ranging from one-eighth to three-eighths, or even half-inch the hand drill presses shown at C and D are used. These have a pad at the upper end by which pressure may be exerted with the chest in order to feed the drill into the work, and for this reason they are termed "breast drills." The form at C has compound gearing, the drill chuck being driven by the usual form of bevel pinion in mesh with a larger bevel gear at one end of a countershaft. A small helical spur pinion at the other end of this countershaft receives its motion from a larger gear turned by the hand crank. This arrangement of gearing permits of high spindle speed without the use of large gears, as would be necessary if but two were used. The form at D gives two speeds, one for use with small drills is obtained by engaging the lower bevel pinion with the chuck spindle and driving it by the large ring gear. The slow speed is obtained by shifting the clutch so that the top bevel pinion drives the drill chuck. As this meshes with a gear but slightly larger in diameter, a slow speed of the drill chuck is possible. Breast drills are provided with a handle screwed into the side of the frame, these are used to steady the drill press. For drilling extremely large holes which are beyond the capacity of the usual form of drill press the ratchet form shown at B, may be used or the bit brace outlined at E. The drills used with either of these have square shanks, whereas those used in the drill presses have round shanks. The bit brace is also used widely in wood work and the form shown is provided with a ratchet by which the bit chuck may be turned through only a portion of a revolution in either direction if desired. DRILLS, REAMERS, TAPS AND DIES In addition to the larger machine tools and the simple hand tools previously described, an essential item of equipment of any engine or plane repair shop, even in cases where the ordinary machine tools are not provided, is a complete outfit of drills, reamers, and threading tools. Drills are of two general classes, the flat and the twist drills. The flat drill has an angle between cutting edges of about 110 degrees and is usually made from special steel commercially known as drill rod. A flat drill cannot be fed into the work very fast because it removes metal by a scraping, rather than a cutting process. The twist drill in its simplest form is cylindrical throughout the entire length and has spiral flutes which are ground off at the end to form the cutting lip and which also serve to carry the metal chips out of the holes. The simplest form of twist drill used is shown at Fig. 168, C, and is known as a "chuck" drill, because it must be placed in a suitable chuck to turn it. A twist drill removes metal by cutting and it is not necessary to use a heavy feed as the drill will tend to feed itself into the work. [Illustration: Fig. 168.--Forms of Drills Used in Hand and Power Drilling Machines.] Larger drills than 3/4-inch are usually made with a tapered shank as shown at Fig. 168, B. At the end of the taper a tongue is formed which engages with a suitable opening in the collet, as the piece used to support the drill is called. The object of this tongue is to relieve the tapered portion of the drill from the stress of driving by frictional contact alone, as this would not turn the drill positively and the resulting slippage would wear the socket, this depreciation changing the taper and making it unfit for other drills. The tongue is usually proportioned so it is adequate to drive the drill under any condition. A small keyway is provided in the collet into which a tapering key of flat stock may be driven against the end of the tongue to drive the drill from the spindle. A standard taper for drill shanks generally accepted by the machine trade is known as the Morse and is a taper of five-eighths of an inch to the foot. The Brown and Sharp form tapers six-tenths of an inch to the foot. Care must be taken, therefore, when purchasing drills and collets, to make sure that the tapers coincide, as no attempt should be made to run a Morse taper in a Brown and Sharp collet, or vice versa. Sometimes cylindrical drills have straight flutes, as outlined at Fig. 168, A. Such drills are used with soft metals and are of value when the drill is to pass entirely through the work. The trouble with a drill with spiral flutes is that it will tend to draw itself through as the cutting lips break through. This catching of the drill may break it or move the work from its position. With a straight flute drill the cutting action is practically the same as with the flat drill shown at Fig. 168, E and F. If a drill is employed in boring holes through close-grained, tough metals, as wrought or malleable iron and steel, the operation will be facilitated by lubricating the drill with plenty of lard oil or a solution of soda and water. Either of these materials will effectually remove the heat caused by the friction of the metal removed against the lips of the drill, and the danger of heating the drill to a temperature that will soften it by drawing the temper is minimized. In drilling large or deep holes it is good practice to apply the lubricating medium directly at the drill point. Special drills of the form shown at Fig. 168, B, having a spiral oil tube running in a suitably formed channel, provides communication between the point of the drill and a suitable receiving hole on a drilled shank. The oil is supplied by a pump and its pressure not only promotes positive circulation and removal of heat, but also assists in keeping the hole free of chips. In drilling steel or wrought iron, lard oil applied to the point of the drill will facilitate the drilling, but this material should never be used with either brass or cast iron. The sizes to be provided depend upon the nature of the work and the amount of money that can be invested in drills. It is common practice to provide a set of drills, such as shown at Fig. 169, which are carried in a suitable metal stand, these being known as number drills on account of conforming to the wire gauge standards. Number drills do not usually run higher than 5/16 inch in diameter. Beyond this point drills are usually sold by the diameter. A set of chuck drills, ranging from 3/8 to 3/4 inch, advancing by 1/32 inch, and a set of Morse taper shank drills ranging from 3/4 to 1-1/4 inches, by increments of 1/16 inch, will be all that is needed for the most pretentious repair shop, as it is cheaper to bore holes larger than 1-1/4 inches with a boring tool than it is to carry a number of large drills in stock that would be used very seldom, perhaps not enough to justify their cost. [Illustration: Fig. 169.--Useful Set of Number Drills, Showing Stand for Keeping These in an Orderly Manner.] In grinding drills, care must be taken to have the lips of the same length, so that they will form the same angle with the axis. If one lip is longer than the other, as shown in the flat drill at Fig. 168, E, the hole will be larger than the drill size, and all the work of cutting will come upon the longest lip. The drill ends should be symmetrical, as shown at Fig. 168, F. [Illustration: Fig. 170.--Illustrating Standard Forms of Hand and Machine Reamers.] It is considered very difficult to drill a hole to an exact diameter, but for the most work a variation of a few thousandths of an inch is of no great moment. Where accuracy is necessary, holes must be reamed out to the required size. In reaming, a hole is drilled about 1/32 inch smaller than is required, and is enlarged with a cutting tool known as the reamer. Reamers are usually of the fluted form shown at Fig. 170, A. Tools of this nature are not designed to remove considerable amounts of metal, but are intended to augment the diameter of the drill hole by only a small fraction of an inch. Reamers are tapered slightly at the point in order that they will enter the hole easily, but the greater portion of the fluted part is straight, all cutting edges being parallel. Hand reamers are made in either the straight or taper forms, that at A, Fig. 170, being straight, while B has tapering flutes. They are intended to be turned by a wrench similar to that employed in turning a tap, as shown at Fig. 172, C. The reamer shown at Fig. 170, C, is a hand reamer. The form at D has spiral flutes similar to a twist drill, and as it is provided with a taper shank it is intended to be turned by power through the medium of a suitable collet. As the solid reamers must become reduced in size when sharpened, various forms of inserted blade reamers have been designed. One of these is shown at E, and as the cutting surfaces become reduced in diameter it is possible to replace the worn blades with others of proper size. Expanding reamers are of the form shown at F. These have a bolt passing through that fits into a tapering hole in the interior of the split reamer portion of the tool. If the hole is to be enlarged a few thousandths of an inch, it is possible to draw up on the nut just above the squared end of the shank, and by drawing the tapering wedge farther into the reamer body, the cutting portion will be expanded and will cut a larger hole. Reamers must be very carefully sharpened or there will be a tendency toward chattering with a consequent production of a rough surface. There are several methods of preventing this chattering, one being to separate the cutting edges by irregular spaces, while the most common method, and that to be preferred on machine reamers, is to use spiral flutes, as shown at Fig. 170, D. Special taper reamers are made to conform to the various taper pin sizes which are sometimes used in holding parts together in an engine. A taper of 1/16 inch per foot is intended for holes where a pin, once driven in, is to remain in place. When it is desired that the pin be driven out, the taper is made steeper, generally 1/4 inch per foot, which is the standard taper used on taper pins. [Illustration: Fig. 171.--Tools for Thread Cutting.] When threads are to be cut in a small hole, it will be apparent that it will be difficult to perform this operation economically on a lathe, therefore when internal threading is called for, a simple device known as a "tap" is used. There are many styles of taps, all conforming to different standards. Some are for metric or foreign threads, some conform to the American standards, while others are used for pipe and tubing. Hand taps are the form most used in repair shops, these being outlined at Fig. 171, A and B. They are usually sold in sets of three, known respectively as taper, plug, and bottoming. The taper tap is the one first put into the hole, and is then followed by the plug tap which cuts the threads deeper. If it is imperative that the thread should be full size clear to the bottom of the hole, the third tap of the set, which is straight-sided, is used. It would be difficult to start a bottoming tap into a hole because it would be larger in diameter at its point than the hole. The taper tap, as shown at A, Fig. 171, has a portion of the cutting lands ground away at the point in order that it will enter the hole. The manipulation of a tap is not hard, as it does not need to be forced into the work, as the thread will draw it into the hole as the tap is turned. The tapering of a tap is done so that no one thread is called upon to remove all of the metal, as for about half way up the length of the tap each succeeding thread is cut a little larger by the cutting edge until the full thread enters the hole. Care must be taken to always enter a tap straight in order to have the thread at correct angles to the surface. In cutting external threads on small rods or on small pieces, such as bolts and studs, it is not always economical to do this work in the lathe, especially in repair work. Dies are used to cut threads on pieces that are to be placed in tapped holes that have been threaded by the corresponding size of tap. Dies for small work are often made solid, as shown at Fig. 171, C, but solid dies are usually limited to sizes below 1/2 inch. Sometimes the solid die is cylindrical in shape, with a slot through one side which enables one to obtain a slight degree of adjustment by squeezing the slotted portion together. Large dies, or the sizes over 1/2 inch, are usually made in two pieces in order that the halves may be closed up or brought nearer together. The advantage of this form of die is that either of the two pieces may be easily sharpened, and as it may be adjusted very easily the thread may be cut by easy stages. For example, the die may be adjusted to cut large, which will produce a shallow thread that will act as an accurate guide when the die is closed up and a deeper thread cut. [Illustration: Fig. 172.--Showing Holder Designs for One- and Two-Piece Thread Cutting Dies.] A common form of die holder for an adjustable die is shown at Fig. 172, A. As will be apparent, it consists of a central body portion having guide members to keep the die pieces from falling out and levers at each end in order to permit the operator to exert sufficient force to remove the metal. The method of adjusting the depth of thread with a clamp screw when a two-piece die is employed is also clearly outlined. The diestock shown at B is used for the smaller dies of the one-piece pattern, having a slot in order that they may be closed up slightly by the clamp screw. The reverse side of the diestock shown at B is outlined below it, and the guide pieces, which may be easily moved in or out, according to the size of the piece to be threaded by means of eccentrically disposed semi-circular slots in the adjustment plate, are shown. These movable guide members have small pins let into their surface which engage the slots, and they may be moved in or out, as desired, according to the position of the adjusting plate. The use of the guide pieces makes for accurate positioning or centering of the rod to be threaded. Dies are usually sold in sets, and are commonly furnished as a portion of a complete outfit such as outlined at Fig. 173. That shown has two sizes of diestock, a tap wrench, eight assorted dies, eight assorted taps, and a small screw driver for adjusting the die. An automobile repair shop should be provided with three different sets of taps and dies, as three different standards for the bolts and nuts are used in fastening automobile components. These are the American, metric (used on foreign engines), and the S. A. E. standard threads. A set of pipe dies and taps will also be found useful. [Illustration: Fig. 173.--Useful Outfit of Taps and Dies for the Engine Repair Shop.] MEASURING TOOLS The tool outfit of the machinist or the mechanic who aspires to do machine work must include a number of measuring tools which are not needed by the floor man or one who merely assembles and takes apart the finished pieces. The machinist who must convert raw material into finished products requires a number of measuring tools, some of which are used for taking only approximate measurements, such as calipers and scales, while others are intended to take very accurate measurements, such as the Vernier and the micrometer. A number of common forms of calipers are shown at Fig. 174. These are known as inside or outside calipers, depending upon the measurements they are intended to take. That at A is an inside caliper, consisting of two legs, A and D, and a gauging piece, B, which can be locked to leg A, or released from that member by the screw, C. The object of this construction is to permit of measurements being taken at the bottom of a two diameter hole, where the point to be measured is of larger diameter than the portion of the hole through which the calipers entered. It will be apparent that the legs A and D must be brought close together to pass through the smaller holes. This may be done without losing the setting, as the guide bar B will remain in one position as determined by the size of the hole to be measured, while the leg A may be swung in to clear the obstruction as the calipers are lifted out. When it is desired to ascertain the measurements the leg A is pushed back into place into the slotted portion of the guide B, and locked by the clamp screw C. A tool of this form is known as an internal transfer caliper. [Illustration: Fig. 174.--Common Forms of Inside and Outside Calipers.] The form of caliper shown at B is an outside caliper. Those at C and D are special forms for inside and outside work, the former being used, if desired, as a divider, while the latter may be employed for measuring the walls of tubing. The calipers at E are simple forms, having a friction joint to distinguish them from the spring calipers shown at B, C and D. In order to permit of ready adjustment of a spring caliper, a split nut as shown at G is sometimes used. A solid nut caliper can only be adjusted by screwing the nut in or out on the screw, which may be a tedious process if the caliper is to be set from one extreme to the other several times in succession. With a slip nut as shown at G it is possible to slip it from one end of the thread to the other without turning it, and of locking it in place at any desired point by simply allowing the caliper leg to come in contact with it. The method of adjusting a spring caliper is shown at Fig. 174, H. Among the most common of the machinist's tools are those used for linear measurements. The usual forms are shown in group, Fig. 175. The most common tool, which is widely known, is the carpenter's folding two-foot rule or the yardstick. While these are very convenient for taking measurements where great accuracy is not required, the machinist must work much more accurately than the carpenter, and the standard steel scale which is shown at D, is a popular tool for the machinist. The steel scale is in reality a graduated straight edge and forms an important part of various measuring tools. These are made of high grade steel and vary from 1 to 48 inches in length. They are carefully hardened in order to preserve the graduations, and all surfaces and edges are accurately ground to insure absolute parallelism. The graduations on the high grade scales are produced with a special device known as a dividing engine, but on cheaper scales, etching suffices to provide a fairly accurate graduation. The steel scales may be very thin and flexible, or may be about an eighth of an inch thick on the twelve-inch size, which is that commonly used with combination squares, protractors and other tools of that nature. The repairman's scale should be graduated both with the English system, in which the inches are divided into eighths, sixteenths, thirty-secondths and sixty-fourths, and also in the metric system, divided into millimeters and centimeters. Some machinists use scales graduated in tenths, twentieths, fiftieths and hundredths. This is not as good a system of graduation as the more conventional one first described. [Illustration: Fig. 175.--Measuring Appliances for the Machinist and Floor Man.] Some steel scales are provided with a slot or groove cut the entire length on one side and about the center of the scales. This permits the attachment of various fittings such as the protractor head, which enables the machinist to measure angles, or in addition the heads convert the scale into a square or a tool permitting the accurate bisecting of pieces of circular section. Two scales are sometimes joined together to form a right angle, such as shown at Fig. 175, C. This is known as a square and is very valuable in ascertaining the truth of vertical pieces that are supposed to form a right angle with a base piece. The Vernier is a device for reading finer divisions on a scale than those into which the scale is divided. Sixty-fourths of an inch are about the finest division that can be read accurately with the naked eye. When fine work is necessary a Vernier is employed. This consists essentially of two rules so graduated that the true scale has each inch divided into ten equal parts, the upper or Vernier portion has ten divisions occupying the same space as nine of the divisions of the true scale. It is evident, therefore, that one of the divisions of the Vernier is equal to nine-tenths of one of those on the true scale. If the Vernier scale is moved to the right so that the graduations marked "1" shall coincide, it will have moved one-tenth of a division on the scale or one-hundredth of an inch. When the graduations numbered 5 coincide the Vernier will have moved five-hundredths of an inch; when the lines marked 0 and 10 coincide, the Vernier will have moved nine-hundredths of an inch, and when 10 on the Vernier comes opposite 10 on the scales, the upper rule will have moved ten-hundredths of an inch, or the whole of one division on the scale. By this means the scale, though it may be graduated only to tenths of an inch, may be accurately set at points with positions expressed in hundredths of an inch. When graduated to read in thousandths, the true scale is divided into fifty parts and the Vernier into twenty parts. Each division of the Vernier is therefore equal to nineteen-twentieths of one of the true scale. If the Vernier be moved so the lines of the first division coincide, it will have moved one-twentieth of one-fiftieth, or .001 inch. The Vernier principle can be readily grasped by studying the section of the Vernier scale and true scale shown at Fig. 176, A. [Illustration: Fig. 176.--At Left, Special Form of Vernier Caliper for Measuring Gear Teeth; at Right, Micrometer for Accurate Internal Measurements.] The caliper scale which is shown at Fig. 175, A, permits of taking the over-all dimension of any parts that will go between the jaws. This scale can be adjusted very accurately by means of a fine thread screw attached to a movable jaw and the divisions may be divided by eye into two parts if one sixty-fourth is the smallest of the divisions. A line is indicated on the movable jaw and coincides with the graduations on the scale. As will be apparent, if the line does not coincide exactly with one of the graduations it will be at some point between the lines and the true measurement may be approximated without trouble. A group of various other measuring tools of value to the machinist is shown at Fig. 177. The small scale at A is termed a "center gauge," because it can be used to test the truth of the taper of either a male or female lathe center. The two smaller nicks, or v's, indicate the shape of a standard thread, and may be used as a guide for grinding the point of a thread-cutting tool. The cross level which is shown at B is of marked utility in erecting, as it will indicate absolutely if the piece it is used to test is level. It will indicate if the piece is level along its width as well as its length. [Illustration: Fig. 177.--Measuring Appliances of Value in Airplane Repair Work.] A very simple attachment for use with a scale that enables the machinist to scribe lines along the length of a cylindrical piece is shown at Fig. 177, C. These are merely small wedge-shaped clamps having an angular face to rest upon the bars. The thread pitch gauge which is shown at Fig. 177, D, is an excellent pocket tool for the mechanic, as it is often necessary to determine without loss of time the pitch of the thread on a bolt or in a nut. This consists of a number of leaves having serrations on one edge corresponding to the standard thread it is to be used in measuring. The tool shown gives all pitches up to 48 threads per inch. The leaves may be folded in out of the way when not in use, and their shape admits of their being used in any position without the remainder of the set interfering with the one in use. The fine pitch gauges have slim, tapering leaves of the correct shape to be used in finding the pitch of small nuts. As the tool is round when the leaves are folded back out of the way, it is an excellent pocket tool, as there are no sharp corners to wear out the pocket. Practical application of a Vernier having measuring heads of special form for measuring gear teeth is shown at Fig. 176, A. As the action of this tool has been previously explained, it will not be necessary to describe it further. MICROMETER CALIPERS AND THEIR USE Where great accuracy is necessary in taking measurements the micrometer caliper, which in the simple form will measure easily .001 inch (one-thousandth part of an inch) and when fitted with a Vernier that will measure .0001 inch (one ten-thousandth part of an inch), is used. The micrometer may be of the caliper form for measuring outside diameters or it may be of the form shown at Fig. 176, B, for measuring internal diameters. The operation of both forms is identical except that the internal micrometer is placed inside of the bore to be measured while the external form is used just the same as a caliper. The form outlined will measure from one and one-half to six and a half inches as extension points are provided to increase the range of the instrument. The screw has a movement of one-half inch and a hardened anvil is placed in the end of the thimble in order to prevent undue wear at that point. The extension points or rods are accurately made in standard lengths and are screwed into the body of the instrument instead of being pushed in, this insuring firmness and accuracy. Two forms of micrometers for external measurements are shown at Fig. 178. The top one is graduated to read in thousandths of an inch, while the lower one is graduated to indicate hundredths of a millimeter. The mechanical principle involved in the construction of a micrometer is that of a screw free to move in a fixed nut. An opening to receive the work to be measured is provided by the backward movement of the thimble which turns the screw and the size of the opening is indicated by the graduations on the barrel. [Illustration: Fig. 178.--Standard Forms of Micrometer Caliper for External Measurements.] The article to be measured is placed between the anvil and spindle, the frame being held stationary while the thimble is revolved by the thumb and finger. The pitch of the screw thread on the concealed part of the spindle is 40 to an inch. One complete revolution of the spindle, therefore, moves it longitudinally one-fortieth, or twenty-five thousandths of an inch. As will be evident from the development of the scale on the barrel of the inch micrometer, the sleeve is marked with forty lines to the inch, each of these lines indicating twenty-five thousandths. The thimble has a beveled edge which is graduated into twenty-five parts. When the instrument is closed the graduation on the beveled edge of the thimble marked 0 should correspond to the 0 line on the barrel. If the micrometer is rotated one full turn the opening between the spindle and anvil will be .025 inch. If the thimble is turned only one graduation, or one twenty-fifth of a revolution, the opening between the spindle and anvil will be increased only by .001 inch (one-thousandth of an inch). As many of the dimensions of the airplane parts, especially of those of foreign manufacture or such parts as ball and roller bearings, are based on the metric system, the competent repairman should possess both inch and metric micrometers in order to avoid continual reference to a table of metric equivalents. With a metric micrometer there are fifty graduations on the barrel, these representing .01 of a millimeter, or approximately .004 inch. One full turn of the barrel means an increase of half a millimeter, or .50 mm. (fifty one-hundredths). As it takes two turns to augment the space between the anvil and the stem by increments of one millimeter, it will be evident that it would not be difficult to divide the spaces on the metric micrometer thimble in halves by the eye, and thus the average workman can measure to .0002 inch plus or minus without difficulty. As set in the illustration, the metric micrometers show a space of 13.5 mm., or about one millimeter more than half an inch. The inch micrometer shown is set to five-tenths or five hundred one-thousandths or one-half inch. A little study of the foregoing matter will make it easy to understand the action of either the inch or metric micrometer. Both of the micrometers shown have a small knurled knob at the end of the barrel. This controls the ratchet stop, which is a device that permits a ratchet to slip by a pawl when more than a certain amount of pressure is applied, thereby preventing the measuring spindle from turning further and perhaps springing the instrument. A simple rule that can be easily memorized for reading the inch micrometer is to multiply the number of vertical divisions on the sleeve by 25 and add to that the number of divisions on the bevel of the thimble reading from the zero to the line which coincides with the horizontal line on the sleeve. For example: if there are ten divisions visible on the sleeve, multiply this number by 25, then add the number of divisions shown on the bevel of the thimble, which is 10. The micrometer is therefore opened 10 × 25 equals 250 plus 10 equals 260 thousandths. Micrometers are made in many sizes, ranging from those having a maximum opening of one inch to special large forms that will measure forty or more inches. While it is not to be expected that the repairman will have use for the big sizes, if a caliper having a maximum opening of six inches is provided with a number of extension rods enabling one to measure smaller objects, practically all of the measuring needed in repairing engine parts can be made accurately. Two or three smaller micrometers having a maximum range of two or three inches will also be found valuable, as most of the measurements will be made with these tools which will be much easier to handle than the larger sizes. TYPICAL TOOL OUTFITS The equipment of tools necessary for repairing airplane engines depends entirely upon the type of the power plant and while the common hand tools can be used on all forms, the work is always facilitated by having special tools adapted for reaching the nuts and screws that would be hard to reach otherwise. Special spanners and socket wrenches are very desirable. Then again, the nature of the work to be performed must be taken into consideration. Rebuilding or overhauling an engine calls for considerably more tools than are furnished for making field repairs or minor adjustments. A complete set of tools supplied to men working on Curtiss OX-2 engines and JN-4 training biplanes is shown at Fig. 179. The tools are placed in a special box provided with a hinged cover and are arranged in the systematic manner outlined. The various tools and supplies shown are: A, hacksaw blades; B, special socket wrenches for engine bolts and nuts; C, ball pein hammers, four sizes; D, five assorted sizes of screw drivers ranging from very long for heavy work to short and small for fine work; E, seven pairs of pliers including combination in three sizes, two pairs of cutting pliers and one round nose; F, two split pin extractors and spreaders; G, wrench set including three adjustable monkey wrenches, one Stillson or pipe wrench, five sizes adjustable end wrenches and ten double end S wrenches; H, set of files, including flat, three cornered and half round; I, file brush; J, chisel and drift pin; K, three small punches or drifts; L, hacksaw frame; M, soldering copper; N, special spanners for propeller retaining nuts; O, special spanners; P, socket wrenches, long handle; Q, long handle, stiff bristle brushes for cleaning motor; R, gasoline blow torch; S, hand drill; T, spools of safety wire; U, flash lamp; V, special puller and castle wrenches; W, oil can; X, large adjustable monkey wrench; Y, washer and gasket cutter; Z, ball of heavy twine. In addition to the tools, various supplies, such as soldering acid, solder, shellac, valve grinding compound, bolts and nuts, split pins, washers, wood screws, etc., are provided. [Illustration: Fig. 179.--Special Tools for Maintaining Curtiss OX-2 Motor Used in Curtiss JN-4 Training Biplane.] SPECIAL HALL-SCOTT TOOLS NO. TOOL DIRECTIONS FOR USE 1 Engine hoisting hook, 6-cylinder Hook under cam-shaft housing, when hoisting engine. 2 Engine hoisting hook, 4-cylinder Hook under cam-shaft housing, when hoisting engine. 3 Water plug wrench For use on water plugs on top and end of cylinders. 4 Vertical shaft flange puller For pulling lower pinion shaft flange from shaft. (Used on A-5 and A-7 engines only.) 5 Oil gun For general lubrication use. 6 Magneto gear puller For pulling magneto gears from magneto shaft. 7 Socket wrench, 1/4" A.L.A.M. For use on bolts and nuts on crank cases. 8 Socket wrench, 1/4" A.L.A.M For use on crank cases and magneto gear housings. 9 Socket wrench, 1/4" A.L.A.M. For use on magneto gear housings. 10 Socket wrench, 3/8" standard For bolts and nuts which fasten magnetos to crank-case. 11 Socket wrench, 1/4" A.L.A.M. For use on magneto gear housings. 12 Vertical shaft gear puller For removing water pump and magneto drive gear. 13 Brace and facing cutter For facing lugs on cylinders for cylinder hold down stud washers. 14 Handle for brace Use with brace. 15 Valve grinding brace For grinding in valves. 16 Socket wrench base, 3/8" A.L.A.M. For thrust bearing cap screws. 17 Brace and facing cutter, 5/16" For facing lugs on rocker arm A.L.A.M. covers. 18 Valve grinding screw driver For grinding in valves. 19 Valve spring tool For putting on and taking off valve springs. 20 Block-valve spring tool For use with valve spring tool. 21 Socket wrench, 5/8" A.L.A.M. For main bearing nuts. 22 Socket wrench, 1/4" A.L.A.M. For use on cam-shaft housing. 23 Socket wrench, 5/16" A.L.A.M. For cam-shaft housing hold down stud nuts. 24 Socket wrench, 1/2" A.L.A.M. For cylinder hold down stud nuts. 25 Socket wrench, 5/16" A.L.A.M. For carburetor and water pump bolts and nuts. 26 Socket wrench, 5/16" A.L.A.M. For carburetor and water pump bolts and nuts. 27 Socket wrench For use on carburetor jets. 28 Magneto screw driver For general magneto use. 29 Brass bar, 1" diameter × 7" long For driving piston pins from pistons. 30 Hack saw For general use. 31 Oil can For cam-shaft housing lubrication. 32 Gasoline or distillate can For priming or other use. 33 Oil can For magneto gear lubrication. 34 Shellac can For rubber hose connections and gaskets. 35 Magneto cleaner For use on magnetos. 36 Clamps For holding cylinder hold down studs, when fitting main bearings. 37 Piston guards For use in pistons, when out of engine, to protect them. 38 Screw driver For general use. 39 Vertical shaft clamps For clamping vertical shaft flanges, when timing engine. 40 Thrust adjusting nut wrench For adjusting propeller thrust bearing. 41 Stuffing box spanner wrench For adjusting stuffing box nut on vertical shaft. 42 Water pump spanner wrench For adjusting water pump stuffing nut. 43 Wrench For use on cylinder relief cocks and cylinder priming cocks. 44 Hose clamp wrench For use on hose clamps. 45 Scraper For cleaning piston ring grooves on pistons. 46 Crank-shaft nut wrench For adjusting crank-shaft nut. 47 Spark-plug wrench For putting in and taking out spark-plugs in cylinders. 48 Timing disc (single disc) For use on crank-shaft to time engine. Specify type motor disc should be made for. If double disc is required, specify the two types of motors the disc is to be made for. Double disc. 49 Main bearing scraper For scraping in bearings. 50 Cylinder carbon scraper For removing carbon from heads of cylinders. 51 Valve seating tool For seating valves in cylinder heads. 52 Scraper, small For general bearing use. 53 Scraper, large For general bearing use. 54 Crank-shaft flange puller For pulling crank-shaft flange from crank-shaft. 55 Piston and connecting rod racks. 56 Main bearing stud nuts and shim rack. 57 Main bearing board rack. 58 Rocker arm and cover rack. The special tools and fixtures recommended by the Hall-Scott Company for work on their engines are clearly shown at Fig. 180. All tools are numbered and their uses may be clearly understood by reference to the illustration and explanatory list given on pages 410 and 411. OVERHAULING AIRPLANE ENGINES After an airplane engine has been in use for a period ranging from 60 to 80 hours, depending upon the type, it is necessary to give it a thorough overhauling before it is returned to service. To do this properly, the engine is removed from the fuselage and placed on a special supporting stand, such as shown at Fig. 181, so it can be placed in any position and completely dismantled. With a stand of this kind it is as easy to work on the bottom of the engine as on the top and every part can be instantly reached. The crank-case shown in place in illustration is in a very convenient position for scraping in the crank-shaft bearings. [Illustration: Fig. 180.--Special Tools and Appliances to Facilitate Overhauling Work on Hall-Scott Airplane Engines.] In order to look over the parts of an engine and to restore the worn or defective components it is necessary to take the engine entirely apart, as it is only when the power plant is thoroughly dismantled that the parts can be inspected or measured to determine defects or wear. If one is not familiar with the engine to be inspected, even though the work is done by a repairman of experience, it will be found of value to take certain precautions when dismantling the engine in order to insure that all parts will be replaced in the same position they occupied before removal. There are a number of ways of identifying the parts, one of the simplest and surest being to mark them with steel numbers or letters or with a series of center punch marks in order to retain the proper relation when reassembling. This is of special importance in connection with dismantling multiple cylinder engines as it is vital that pistons, piston rings, connecting rods, valves, and other cylinder parts be always replaced in the same cylinder from which they were removed, because it is uncommon to find equal depreciation in all cylinders. Some repairmen use small shipping tags to identify the pieces. This can be criticised because the tags may become detached and lost and the identity of the piece mistaken. If the repairing is being done in a shop where other engines of the same make are being worked on, the repairman should be provided with a large chest fitted with a lock and key in which all of the smaller parts, such as rods, bolts and nuts, valves, gears, valve springs, cam-shafts, etc., may be stored to prevent the possibility of confusion with similar members of other engines. All parts should be thoroughly cleaned with gasoline or in the potash kettle as removed, and wiped clean and dry. This is necessary to show wear which will be evidenced by easily identified indications in cases where the machine has been used for a time, but in others, the deterioration can only be detected by delicate measuring instruments. [Illustration: Fig. 181.--Special Stand to Make Motor Overhauling Work Easier.] In taking down a motor the smaller parts and fittings such as spark-plugs, manifolds and wiring should be removed first. Then the more important members such as cylinders may be removed from the crank-case to give access to the interior and make possible the examination of the pistons, rings and connecting rods. After the cylinders are removed the next operation is to disconnect the connecting rods from the crank-shaft and to remove them and the pistons attached as a unit. Then the crank-case is dismembered, in most cases by removing the bottom half or oil sump, thus exposing the main bearings and crank-shaft. The first operation is the removal of the inlet and exhaust manifolds. In some cases the manifolds are cored integral with the cylinder head casting and it is merely necessary to remove a short pipe leading from the carburetor to one inlet opening and the exhaust pipe from the outlet opening common to all cylinders. In order to remove the carburetor it is necessary to shut off the gasoline supply at the tank and to remove the pipe coupling at the float chamber. It is also necessary to disconnect the throttle operating rod. After the cylinders are removed and before taking the crank-case apart it is well to remove the water pump and magneto. The wiring on most engines of modern development is carried in conduits and usually releasing two or three minor fastenings will permit one to take off the plug wiring as a unit. The wire should be disconnected from both spark-plugs and magneto distributor before its removal. When the cylinders are removed, the pistons, piston rings, and connecting rods are clearly exposed and their condition may be readily noticed. Before disturbing the arrangement of the timing gears, it is important that these be marked so that they will be replaced in exactly the same relation as intended by the engine designer. If the gears are properly marked the valve timing and magneto setting will be undisturbed when the parts are replaced after overhauling. With the cylinders off, it is possible to ascertain if there is any undue wear present in the connecting rod bearings at either the wrist pin or crank-pin ends and also to form some idea of the amount of carbon deposits on the piston top and back of the piston rings. Any wear of the timing gears can also be determined. The removal of the bottom plate of the engine enables the repairman to see if the main bearings are worn unduly. Often bearings may be taken up sufficiently to eliminate all looseness. In other cases they may be worn enough so that careful refitting will be necessary. Where the crank-case is divided horizontally into two portions, the upper one serving as an engine base to which the cylinders and in fact all important working parts are attached, the lower portion performs the functions of an oil container and cover for the internal mechanism. This is the construction generally followed. DEFECTS IN CYLINDERS After the cylinders have been removed and stripped of all fittings, they should be thoroughly cleaned and then carefully examined for defects. The interior or bore should be looked at with a view of finding score marks, grooves, cuts or scratches in the interior, because there are many faults that may be ascribed to depreciation at this point. The cylinder bore may be worn out of round, which can only be determined by measuring with an internal caliper or dial indicator even if the cylinder bore shows no sign of wear. The flange at the bottom of the cylinder by which it is held to the engine base may be cracked. The water jacket wall may have opened up due to freezing of the jacket water at some time or other or it may be filled with scale and sediment due to the use of impure cooling water. The valve seat may be scored or pitted, while the threads holding the valve chamber cap may be worn so that the cap will not be a tight fit. The detachable head construction makes it possible to remove that member and obtain ready access to the piston tops for scraping out carbon without taking the main cylinder portion from the crank-case. When the valves need grinding the head may be removed and carried to the bench where the work may be performed with absolute assurance that none of the valve grinding compound will penetrate into the interior of the cylinder as is sometimes unavoidable with the I-head cylinder. If the cylinder should be scored, the water jacket and combustion head may be saved and a new cylinder casting purchased at considerably less cost than that of the complete unit cylinder. The detachable head construction has only recently been applied on airplane engines, though it was one of the earliest forms of automobile engine construction. In the early days it was difficult to procure gaskets or packings that would be both gas and water tight. The sheet asbestos commonly used was too soft and blew out readily. Besides a new gasket had to be made every time the cylinder head was removed. Woven wire and asbestos packings impregnated with rubber, red lead, graphite and other filling materials were more satisfactory than the soft sheet asbestos, but were prone to burn out if the water supply became low. Materials such as sheet copper or brass proved to be too hard to form a sufficiently yielding packing medium that would allow for the inevitable slight inaccuracies in machining the cylinder head and cylinder. The invention of the copper-asbestos gasket, which is composed of two sheets of very thin, soft copper bound together by a thin edging of the same material and having a piece of sheet asbestos interposed solved this problem. Copper-asbestos packings form an effective seal against leakage of water and a positive retention means for keeping the explosion pressure in the cylinder. The great advantage of the detachable head is that it permits of very easy inspection of the piston tops and combustion chamber and ready removal of carbon deposits. CARBON DEPOSITS, THEIR CAUSE AND PREVENTION Most authorities agree that carbon is the result of imperfect combustion of the fuel and air mixture as well as the use of lubricating oils of improper flash point. Lubricating oils that work by the piston rings may become decomposed by the great heat in the combustion chamber, but at the same time one cannot blame the lubricating oil for all of the carbon deposits. There is little reason to suspect that pure petroleum oil of proper body will deposit excessive amounts of carbon, though if the oil is mixed with castor oil, which is of vegetable origin, there would be much carbon left in the interior of the combustion chamber. Fuel mixtures that are too rich in gasoline also produce these undesirable accumulations. A very interesting chemical analysis of a sample of carbon scraped from the interior of a motor vehicle engine shows that ordinarily the lubricant is not as much to blame as is commonly supposed. The analysis was as follows: Oil 14.3% Other combustible matter 17.9 Sand, clay, etc. 24.8 Iron oxide 24.5 Carbonate of lime 8.9 Other constituents 9.6 It is extremely probable that the above could be divided into two general classes, these being approximately 32.2% oil and combustible matter and a much larger proportion, or 67.8% of earthy matter. The presence of such a large percentage of earthy matter is undoubtedly due to the impurities in the air, such as road dust which has been sucked in through the carburetor. The fact that over 17% of the matter which is combustible was not of an oily nature lends strong support to this view. There would not be the amount of earthy material present in the carbon deposits of an airplane engine as above stated because the air is almost free from dust at the high altitudes planes are usually flown. One could expect to find more combustible and less earthy matter and the carbon would be softer and more easily removed. It is very good practice to provide a screen on the air intake to reduce the amounts of dust sucked in with the air as well as observing the proper precautions relative to supplying the proper quantities of air to the mixture and of not using any more oil than is needed to insure proper lubrication of the internal mechanism. USE OF CARBON SCRAPERS It is not unusual for one to hear an aviator complain that the engine he operates is not as responsive as it was when new after he has run it but relatively few hours. There does not seem to be anything actually wrong with the engine, yet it does not respond readily to the throttle and is apt to overheat. While these symptoms denote a rundown condition of the mechanism, the trouble is often due to nothing more serious than accumulations of carbon. The remedy is the removal of this matter out of place. The surest way of cleaning the inside of the motor thoroughly is to remove the cylinders, if these members are cast integrally with the head or of removing the head member if that is a separate casting, to expose all parts. In certain forms of cylinders, especially those of the L form, it is possible to introduce simple scrapers down through the valve chamber cap holes and through the spark-plug hole if this component is placed in the cylinder in some position that communicates directly to the interior of the cylinder or to the piston top. No claim can be made for originality or novelty of this process as is has been used for many years on large stationary engines. The first step is to dismantle the inlet and exhaust piping and remove the valve caps and valves, although if the deposit is not extremely hard or present in large quantities one can often manipulate the scrapers in the valve cap openings without removing either the piping or the valves. Commencing with the first cylinder, the crank-shaft is turned till the piston is at the top of its stroke, then the scraper may be inserted, and the operation of removing the carbon started by drawing the tool toward the opening. As this is similar to a small hoe, the cutting edge will loosen some of the carbon and will draw it toward the opening. A swab is made of a piece of cloth or waste fastened at the end of a wire and well soaked in kerosene to clean out the cylinder. When available, an electric motor with a length of flexible shaft and a small circular cleaning brush having wire bristles can be used in the interior of the engine. The electric motor need not be over one-eighth horse-power running 1,200 to 1,600 R. P. M., and the wire brush must, of course, be of such size that it can be easily inserted through the valve chamber cap. The flexible shaft permits one to reach nearly all parts of the cylinder interior without difficulty and the spreading out and flattening of the brush insures that considerable surface will be covered by that member. BURNING OUT CARBON WITH OXYGEN A process of recent development that gives very good results in removing carbon without disassembling the motor depends on the process of burning out that material by supplying oxygen to support the combustion and to make it energetic. A number of concerns are already offering apparatus to accomplish this work, and in fact any shop using an autogenous welding outfit may use the oxygen tank and reducing valve in connection with a simple special torch for burning the carbon. Results have demonstrated that there is little danger of damaging the motor parts, and that the cost of oxygen and labor is much lower than the old method of removing the cylinders and scraping the carbon out, as well as being very much quicker than the alternative process of using carbon solvent. The only drawback to this system is that there is no absolute insurance that every particle of carbon will be removed, as small protruding particles may be left at points that the flame does not reach and cause pre-ignition and consequent pounding, even after the oxygen treatment. It is generally known that carbon will burn in the presence of oxygen, which supports combustion of all materials, and this process takes advantage of this fact and causes the gas to be injected into the combustion chamber over a flame obtained by a match or wax taper. [Illustration: Fig. 182.--Showing Where Carbon Deposits Collect in Engine Combustion Chamber, and How to Burn Them Out with the Aid of Oxygen. A--Special Torch. B--Torch Coupled to Oxygen Tank. C--Torch in Use.] It is suggested by those favoring this process that the night before the oxygen is to be used the engine be given a conventional kerosene treatment. A half tumbler full of this liquid or of denatured alcohol is to be poured into each cylinder and permitted to remain there over night. As a precaution against fire, the gasoline is shut off from the carburetor before the torch is inserted in the cylinder and the motor started so that the gasoline in the pipe and carburetor float chamber will be consumed. Work is done on one cylinder at a time. A note of caution was recently sounded by a prominent spark-plug manufacturer recommending that the igniter member be removed from the cylinder in order not to injure it by the heat developed. The outfits on the market consist of a special torch having a trigger controlled valve and a length of flexible tubing such as shown at Fig. 182, A, and a regulating valve and oxygen tank as shown at B. The gauge should be made to register about twelve pounds pressure. The method of operation is very simple and is outlined at C. The burner tube is placed in the cylinder and the trigger valve is opened and the oxygen permitted to circulate in the combustion chamber. A lighted match or wax taper is dropped in the chamber and the injector tube is moved around as much as possible so as to cover a large area. The carbon takes fire and burns briskly in the presence of the oxygen. The combustion of the carbon is accompanied by sparks and sometimes by flame if the deposit is of an oily nature. Once the carbon begins to burn the combustion continues without interruption as long as the oxygen flows into the cylinder. Full instructions accompany each outfit and the amount of pressure for which the regulator should be set depends upon the design of the torch and the amount of oxygen contained in the storage tank. REPAIRING SCORED CYLINDERS If the engine has been run at any time without adequate lubrication, one or more of the cylinders may be found to have vertical scratches running up and down the cylinder walls. The depth of these will vary according to the amount of time the cylinder was without lubrication, and if the grooves are very deep the only remedy is to purchase a new member. Of course, if sufficient stock is available in the cylinder walls, the cylinders may be rebored and new pistons which are oversize, _i.e._, larger than standard, may be fitted. Where the scratches are not deep they may be ground out with a high speed emery wheel or lapped out if that type of machine is not available. Wrist pins have been known to come loose, especially when these are retained by set screws that are not properly locked, and as wrist-pins are usually of hardened steel it will be evident that the sharp edge of that member can act as a cutting tool and make a pronounced groove in the cylinder. Cylinder grinding is a job that requires skilled mechanics, but may be accomplished on any lathe fitted with an internal grinding attachment. While automobile engine cylinders usually have sufficient wall thickness to stand reboring, those of airplane engines seldom have sufficient metal to permit of enlarging the bore very much by a boring tool. A few thousandths of an inch may be ground out without danger, however. An airplane engine cylinder with deep grooves must be scrapped as a general rule. Where the grooves in the cylinder are not deep or where it has warped enough so the rings do not bear equally at all parts of the cylinder bore, it is possible to obtain a fairly accurate degree of finish by a lapping process in which an old piston is coated with a mixture of fine emery and oil and is reciprocated up and down in the cylinder as well as turned at the same time. This may be easily done by using a dummy connecting rod having only a wrist pin end boss, and of such size at the other end so that it can be held in the chuck of a drill press. The cylinder casting is firmly clamped on the drill press table by suitable clamping blocks, and a wooden block is placed in the combustion chamber to provide a stop for the piston at its lower extreme position. The back gears are put in and the drill chuck is revolved slowly. All the while that the piston is turning the drill chuck should be raised up and down by the hand feed lever, as the best results are obtained when the lapping member is given a combination of rotary and reciprocating motion. VALVE REMOVAL AND INSPECTION One of the most important parts of the gasoline engine and one that requires frequent inspection and refitting to keep in condition, is the mushroom or poppet valve that controls the inlet and exhaust gas flow. In overhauling it is essential that these valves be removed from their seatings and examined carefully for various defects which will be enumerated at proper time. The problem that concerns us now is the best method of removing the valve. These are held against the seating in the cylinder by a coil spring which exerts its pressure on the cylinder casting at the upper end and against a suitable collar held by a key at the lower end of the valve stem. In order to remove the valve it is necessary to first compress the spring by raising the collar and pulling the retaining key out of the valve stem. Many forms of valve spring lifters have been designed to permit ready removal of the valves. When the cylinder is of the valve in-the-head form, the method of valve removal will depend entirely upon the system of cylinder construction followed. In the Sturtevant cylinder design it is possible to remove the head from the cylinder castings and the valve springs may be easily compressed by any suitable means when the cylinder head is placed on the work bench where it can be easily worked on. The usual method is to place the head on a soft cloth with the valves bearing against the bench. The valve springs may then be easily pushed down with a simple forked lever and the valve stem key removed to release the valve spring collar. In the Curtiss OX-2 (see Fig. 182-1/2) and Hall-Scott engines it is not possible to remove the valves without taking the cylinder off the crank-case, because the valve seats are machined directly in the cylinder head and the valve domes are cast integrally with the cylinder. This means that if the valves need grinding the cylinder must be removed from the engine base to provide access to the valve heads which are inside of that member, and which cannot be reached from the outside as is true of the L-cylinder construction. In the Curtiss VX engines, the valves are carried in detachable cages which may be removed when the valves need attention. [Illustration: Fig. 182-1/2.--Part Sectional View, Showing Valve Arrangement in Cylinder of Curtiss OX-2 Aviation Engine.] RESEATING AND TRUING VALVES Much has been said relative to valve grinding, and despite the mass of information given in the trade prints it is rather amusing to watch the average repairman or the engine user who prides himself on maintaining his own motor performing this essential operation. The common mistakes are attempting to seat a badly grooved or pitted valve head on an equally bad seat, which is an almost hopeless job, and of using coarse emery and bearing down with all one's weight on the grinding tool with the hope of quickly wearing away the rough surfaces. The use of improper abrasive material is a fertile cause of failure to obtain a satisfactory seating. Valve grinding is not a difficult operation if certain precautions are taken before undertaking the work. The most important of these is to ascertain if the valve head or seat is badly scored or pitted. If such is found to be the case no ordinary amount of grinding will serve to restore the surfaces. In this event the best thing to do is to remove the valve from its seating and to smooth down both the valve head and the seat in the cylinder before attempt is made to fit them together by grinding. Another important precaution is to make sure that the valve stem is straight, and that the head is not warped out of shape. [Illustration: Fig. 183.--Tools for Restoring Valve Head and Seats.] A number of simple tools is available at the present time for reseating valves, these being outlined at Fig. 183. That shown at A is a simple fixture for facing off the valve head. The stem is supported by suitable bearings carried by the body or shank of the tool, and the head is turned against an angularly disposed cutter which is set for the proper valve seat angle. The valve head is turned by a screw-driver, the amount of stock removed from the head depending upon the location of the adjusting screw. Care must be taken not to remove too much metal, only enough being taken off to remove the most of the roughness. Valves are made in two standard tapers, the angle being either 45 or 60 degrees. It is imperative that the cutter blade be set correctly in order that the bevel is not changed. A set of valve truing and valve-seat reaming cutters is shown at Fig. 183, B. This is adaptable to various size valve heads, as the cutter blade D may be moved to correspond to the size of the valve head being trued up. These cutter blades are made of tool steel and have a bevel at each end, one at 45 degrees, the other at 60 degrees. The valve seat reamer shown at G will take any one of the heads shown at F. It will also take any one of the guide bars shown at H. The function of the guide bars is to fit the valve stem bearing in order to locate the reamer accurately and to insure that the valve seat is machined concentrically with its normal center. Another form of valve seat reamer and a special wrench used to turn it is shown at C. The valve head truer shown at Fig. 183, D, is intended to be placed in a vise and is adaptable to a variety of valve head sizes. The smaller valves merely fit deeper in the conical depression. The cutter blade is adjustable and the valve stem is supported by a simple self-centering bearing. In operation it is intended that the valve stem, which protrudes through the lower portion of the guide bearing, shall be turned by a drill press or bit stock while the valve head is set against the cutter by pressure of a pad carried at the end of a feed screw which is supported by a hinged bridge member. This can be swung out of place as indicated to permit placing the valve head against the cutter or removing it. As the sizes of valve heads and stems vary considerably a "Universal" valve head truing tool must have some simple means of centering the valve stem in order to insure concentric machining of the valve head. A valve head truer which employs an ingenious method of guiding the valve stem is shown at Fig. 183, E. The device consists of a body portion, B, provided with an external thread at the top on which the cutter head, A, is screwed. A number of steel balls, C, are carried in the grooves which may be altered in size by the adjustment nut, F, which screws in the bottom of the body portion, B. As the nut F is screwed in against the spacer member E, the V-grooves are reduced in size and the steel balls, C, are pressed out in contact with the valve stem. As the circle or annulus is filled with balls in both upper and lower portions the stem may be readily turned because it is virtually supported by ball bearing guides. When a larger valve stem is to be supported, the adjusting nut F, is screwed out which increases the size of the grooves and permits the balls, C, to spread out and allow the larger stem to be inserted. VALVE GRINDING PROCESSES Mention has been previously made of the importance of truing both valve head and seat before attempt is made to refit the parts by grinding. After smoothing the valve seat the next step is to find some way of turning the valve. Valve heads are usually provided with a screw-driver slot passing through the boss at the top of the valve or with two drilled holes to take a forked grinding tool. A combination grinding tool has been devised which may be used when either the two drilled holes or the slotted head form of valve is to be rotated. This consists of a special form of screw driver having an enlarged boss just above the blade, this boss serving to support a U-shape piece which can be securely held in operative position by the clamp screw or which can be turned out of the way if the screw driver blade is to be used. As it is desirable to turn the valve through a portion of a revolution and back again rather than turning it always in the same direction, a number of special tools has been designed to make this oscillating motion possible without trouble. A simple valve grinding tool is shown at Fig. 184, C. This consists of a screw-driver blade mounted in a handle in such a way that the end may turn freely in the handle. A pinion is securely fastened to the screw-driver blade shank, and is adapted to fit a race provided with a wood handle and guided by a bent bearing member securely fastened to the screw-driver handle. As the rack is pushed back and forth the pinion must be turned first in one direction and then in the other. [Illustration: Fig. 184.--Tools and Processes Utilized in Valve Grinding.] A valve grinding tool patterned largely after a breast drill is shown at Fig. 184, D. This is worked in such a manner that a continuous rotation of the operating crank will result in an oscillating movement of the chuck carrying the screw-driver blade. The bevel pinions which are used to turn the chuck are normally free unless clutched to the chuck stem by the sliding sleeve which must turn with the chuck stem and which carries clutching members at each end to engage similar members on the bevel pinions and lock these to the chuck stem, one at a time. The bevel gear carries a cam-piece which moves the clutch sleeve back and forth as it revolves. This means that the pinion giving forward motion of the chuck is clutched to the chuck spindle for a portion of a revolution of the gear and clutch sleeve is moved back by the cam and clutched to the pinion giving a reverse motion of the chuck during the remainder of the main drive gear revolution. It sometimes happens that the adjusting screw on the valve lift plunger or the valve lift plunger itself when L head cylinders are used does not permit the valve head to rest against the seat. It will be apparent that unless a definite space exists between the end of the valve stem and the valve lift plunger that grinding will be of little avail because the valve head will not bear properly against the abrasive material smeared on the valve seat. The usual methods of valve grinding are clearly outlined at Fig. 184. The view at the left shows the method of turning the valve by an ordinary screw driver and also shows a valve head at A, having both the drilled holes and the screw-driver slot for turning the member and two special forms of fork-end valve grinding tools. In the sectional view shown at the right, the use of the light spring between the valve head and the bottom of the valve chamber to lift the valve head from the seat whenever pressure on the grinding tool is released is clearly indicated. It will be noted also that a ball of waste or cloth is interposed in the passage between the valve chamber and the cylinder interior to prevent the abrasive material from passing into the cylinder from the valve chamber. When a bitstock is used, instead of being given a true rotary motion the chuck is merely oscillated through the greater part of the circle and back again. It is necessary to lift the valve from its seat frequently as the grinding operation continues; this is to provide an even distribution of the abrasive material placed between the valve head and its seat. Only sufficient pressure is given to the bitstock to overcome the uplift of the spring and to insure that the valve will be held against the seat. Where the spring is not used it is possible to raise the valve from time to time with the hand which is placed under the valve stem to raise it as the grinding is carried on. It is not always possible to lift the valve in this manner when the cylinders are in place on the engine base owing to the space between the valve lift plunger and the end of the valve stem. In this event the use of the spring as shown in sectional view will be desirable. The abrasive generally used is a paste made of medium or fine emery and lard oil or kerosene. This is used until the surfaces are comparatively smooth, after which the final polish or finish is given with a paste of flour emery, grindstone dust, crocus, or ground glass and oil. An erroneous impression prevails in some quarters that the valve head surface and the seating must have a mirror-like polish. While this is not necessary it is essential that the seat in the cylinder and the bevel surface of the head be smooth and free from pits or scratches at the completion of the operation. All traces of the emery and oil should be thoroughly washed out of the valve chamber with gasoline before the valve mechanism is assembled and in fact it is advisable to remove the old grinding compound at regular intervals, wash the seat thoroughly and supply fresh material as the process is in progress. The truth of seatings may be tested by taking some Prussian blue pigment and spreading a thin film of it over the valve seat. The valve is dropped in place and is given about one-eighth turn with a little pressure on the tool. If the seating is good both valve head and seat will be covered uniformly with color. If high spots exist, the heavy deposit of color will show these while the low spots will be made evident because of the lack of pigment. The grinding process should be continued until the test shows an even bearing of the valve head at all points of the cylinder seating. When the valves are held in cages it is possible to catch the cage in a vise and to turn the valve in any of the ways indicated. It is much easier to clean off the emery and oil and there is absolutely no danger of getting the abrasive material in the cylinder if the construction is such that the valve cage or cylinder head member carrying the valve can be removed from the cylinder. When valves are held in cages, the tightness of the seat may be tested by partially filling the cage with gasoline and noticing how much liquid oozes out around the valve head. The degree of moisture present indicates the efficacy of the grinding process. The valves of Curtiss OX-2 cylinders are easily ground in by using a simple fixture or tool and working from the top of the cylinder instead of from the inside. A tube having a bore just large enough to go over the valve stem is provided with a wooden handle or taped at one end and a hole of the same size as that drilled through the valve stem is put in at the other. To use, the open end of the tube is pushed over the valve stem and a split pin pushed through the tube and stem. The valve may be easily manipulated and ground in place by oscillating in the customary manner. DEPRECIATION IN VALVE OPERATING SYSTEMS There are a number of points to be watched in the valve operating system because valve timing may be seriously interfered with if there is much lost motion at the various bearing points in the valve lift mechanism. The two conventional methods of opening valves are shown at Fig. 185. That at A is the type employed when the valve cages are mounted directly in the head, while the form at B is the system used when the valves are located in a pocket or extension of the cylinder casting as is the case if an L, or T-head cylinder is used. It will be evident that there are several points where depreciation may take place. The simplest form is that shown at B, and even on this there are five points where lost motion may be noted. The periphery of the valve opening cam or roller may be worn, though this is not likely unless the roller or cam has been inadvertently left soft. The pin which acts as a bearing for the roller may become worn, this occurring quite often. Looseness may materialize between the bearing surfaces of the valve lift plunger and the plunger guide casting, and there may also be excessive clearance between the top of the plunger and the valve stem. [Illustration: Fig. 185.--Outlining Points in Valve Operating Mechanism Where Depreciation is Apt to Exist.] On the form shown at A, there are several parts added to those indicated at B. A walking beam or rocker lever is necessary to transform the upward motion of the tappet rod to a downward motion of the valve stem. The pin on which this member fulcrums may wear as will also the other pin acting as a hinge or bearing for the yoke end of the tappet rod. It will be apparent that if slight play existed at each of the points mentioned it might result in a serious diminution of valve opening. Suppose, for example, that there were .005-inch lost motion at each of three bearing points, the total lost motion would be .015-inch or sufficient to produce noisy action of the valve mechanism. When valve plungers of the adjustable form, such as shown at B, are used, the hardened bolt head in contact with the end of the valve stem may become hollowed out on account of the hammering action at that point. It is imperative that the top of this member be ground off true and the clearance between the valve stem and plunger properly adjusted. If the plunger is a non-adjustable type it will be necessary to lengthen the valve stem by some means in order to reduce the excessive clearance. The only remedy for wear at the various hinges and bearing pins is to bore the holes out slightly larger and to fit new hardened steel pins of larger diameter. Depreciation between the valve plunger guide and the valve plunger is usually remedied by fitting new plunger guides in place of the worn ones. If there is sufficient stock in the plunger guide casting as is sometimes the case when these members are not separable from the cylinder casting, the guide may be bored out and bushed with a light bronze bushing. A common cause of irregular engine operation is due to a sticking valve. This may be owing to a bent valve stem, a weak or broken valve spring or an accumulation of burnt or gummed oil between the valve stem and the valve stem guide. In order to prevent this the valve stem must be smoothed with fine emery cloth and no burrs or shoulders allowed to remain on it, and the stem must also be straight and at right angles to the valve head. If the spring is weak it may be strengthened in some cases by stretching it out after annealing so that a larger space will exist between the coils and re-hardening. Obviously if a spring is broken the only remedy is replacement of the defective member. Mention has been made of wear in the valve stem guide and its influence on engine action. When these members are an integral part of the cylinder the only method of compensating for this wear is to drill the guide out and fit a bushing, which may be made of steel tube. In some engines, especially those of recent development, the valve stem guide is driven or screwed into the cylinder casting and is a separate member which may be removed when worn and replaced with a new one. When the guides become enlarged to such a point that considerable play exists between them and the valve stems, they may be easily knocked out or unscrewed. PISTON TROUBLES If an engine has been entirely dismantled it is very easy to examine the pistons for deterioration. While it is important that the piston be a good fit in the cylinder it is mainly upon the piston rings that compression depends. The piston should fit the cylinder with but little looseness, the usual practice being to have the piston about .001-inch smaller than the bore for each inch of piston diameter at the point where the least heat is present or at the bottom of the piston. It is necessary to allow more than this at the top of the piston owing to its expansion due to the direct heat of the explosion. The clearance is usually graduated and a piston that would be .005-inch smaller than the cylinder bore at the bottom would be about .0065-inch at the middle and .0075-inch at the top. If much more play than this is evidenced the piston will "slap" in the cylinder and the piston will be worn at the ends more than in the center. Aluminum or alloy pistons require more clearance than cast iron ones do, usually 1.50 times as much. Pistons sometimes warp out of shape and are not truly cylindrical. This results in the high spots rubbing on the cylinder while the low spots will be blackened where a certain amount of gas has leaked by. Mention has been previously made of the necessity of reboring or regrinding a cylinder that has become scored or scratched and which allows the gas to leak by the piston rings. When the cylinder is ground out, it is necessary to use a larger piston to conform to the enlarged cylinder bore. Most manufacturers are prepared to furnish over-size pistons, there being four standard over-size dimensions adopted by the S. A. E. for rebored cylinders. These are .010-inch, .020-inch, .030-inch, and .040-inch larger than the original bore. The piston rings should be taken out of the piston grooves and all carbon deposits removed from the inside of the ring and the bottom of the groove. It is important to take this deposit out because it prevents the rings from performing their proper functions by reducing the ring elasticity, and if the deposit is allowed to accumulate it may eventually result in sticking and binding of the ring, this producing excessive friction or loss of compression. When the rings are removed they should be tested to see if they retain their elasticity and it is also well to see that the small pins in some pistons which keep the rings from turning around so the joints will not come in line are still in place. If no pins are found there is no cause for alarm because these dowels are not always used. When fitted, they are utilized with rings having a butt joint or diagonal cut as the superior gas retaining qualities of the lap or step joint render the pins unnecessary. If gas has been blowing by the ring or if these members have not been fitting the cylinder properly the points where the gas passed will be evidenced by burnt, brown or roughened portions of the polished surface of the pistons and rings. The point where this discoloration will be noticed more often is at the thin end of an eccentric ring, the discoloration being present for about 1/2-inch or 3/4-inch each side of the slot. It may be possible that the rings were not true when first put in. This made it possible for the gas to leak by in small amounts initially which increased due to continued pressure until quite a large area for gas escape had been created. PISTON RING MANIPULATION Removing piston rings without breaking them is a difficult operation if the proper means are not taken, but is a comparatively simple one when the trick is known. The tools required are very simple, being three strips of thin steel about one-quarter inch wide and four or five inches long and a pair of spreading tongs made up of one-quarter inch diameter keystock tied in the center with a copper wire to form a hinge. The construction is such that when the hand is closed and the handles brought together the other end of the expander spreads out, an action just opposite to that of the conventional pliers. The method of using the tongs and the metal strips is clearly indicated at Fig. 186. At A the ring expander is shown spreading the ends of the rings sufficiently to insert the pieces of sheet metal between one of the rings and the piston. Grasp the ring as shown at B, pressing with the thumbs on the top of the piston and the ring will slide off easily, the thin metal strips acting as guide members to prevent the ring from catching in the other piston grooves. Usually no difficulty is experienced in removing the top or bottom rings, as these members may be easily expanded and worked off directly without the use of a metal strip. When removing the intermediate rings, however, the metal strips will be found very useful. These are usually made by the repairman by grinding the teeth from old hacksaw blades and rounding the edges and corners in order to reduce the liability of cutting the fingers. By the use of the three metal strips a ring is removed without breaking or distorting it and practically no time is consumed in the operation. FITTING PISTON RINGS Before installing new rings, they should be carefully fitted to the grooves to which they are applied. The tools required are a large piece of fine emery cloth, a thin, flat file, a small vise with copper or leaden jaw clips, and a smooth hard surface such as that afforded by the top of a surface plate or a well planed piece of hard wood. After making sure that all deposits of burnt oil and carbon have been removed from the piston grooves, three rings are selected, one for each groove. The ring is turned all around its circumference into the groove it is to fit, which can be done without springing it over the piston as the outside edge of the ring may be used to test the width of the groove just as well as the inside edge. The ring should be a fair fit and while free to move circumferentially there should be no appreciable up and down motion. If the ring is a tight fit it should be laid edge down upon the piece of emery cloth which is placed on the surface plate and carefully rubbed down until it fits the groove it is to occupy. It is advisable to fit each piston ring individually and to mark them in some way to insure that they will be placed in the groove to which they are fitted. The repairman next turns his attention to fitting the ring in the cylinder itself. The ring should be pushed into the cylinder at least two inches up from the bottom and endeavor should be made to have the lower edge of the ring parallel with the bottom of the cylinder. If the ring is not of correct diameter, but is slightly larger than the cylinder bore, this condition will be evident by the angular slots of the rings being out of line or by difficulty in inserting the ring if it is a lap joint form. If such is the case the ring is removed from the cylinder and placed in the vise between soft metal jaw clips. Sufficient metal is removed with a fine file from the edges of the ring at the slot until the edges come into line and a slight space exists between them when the ring is placed into the cylinder. It is important that this space be left between the ends, for if this is not done when the ring becomes heated the expansion of metal may cause the ends to abut and the ring to jam in the cylinder. [Illustration: Fig. 186.--Method of Removing Piston Rings, and Simple Clamp to Facilitate Insertion of Rings in Cylinder.] It is necessary to use more than ordinary caution in replacing the rings on the piston because they are usually made of cast iron, a metal that is very fragile and liable to break because of its brittleness. Special care should be taken in replacing new rings as these members are more apt to break than old ones. This is probably accounted for by the heating action on used rings which tends to anneal the metal as well as making it less springy. The bottom ring should be placed in position first which is easily accomplished by springing the ring open enough to pass on the piston and then sliding it into place in the lower groove which on some types of engines is below the wrist pin, whereas in others all grooves are above that member. The other members are put in by a reversal of the process outlined at Fig. 186, A and B. It is not always necessary to use the guiding strips of metal when replacing rings as it is often possible, by putting the rings on the piston a little askew and maneuvering them to pass the grooves without springing the ring into them. The top ring should be the last one placed in position. Before placing pistons in the cylinder one should make sure that the slots in the piston rings are spaced equidistant on the piston, and if pins are used to keep the ring from turning one should be careful to make sure that these pins fit into their holes in the ring and that they are not under the ring at any point. Practically all cylinders are chamfered at the lower end to make insertion of piston rings easier. The operation of putting on a cylinder casting over a piston really requires two pairs of hands, one to manipulate the cylinder, the other person to close the rings as they enter the cylinder. This may be done very easily by a simple clamp member made of sheet brass or iron and used to close the ring as indicated at Fig. 186, C. It is apparent that the clamp must be adjusted to each individual ring and that the split portion of the clamp must coincide with the split portion of the ring. The cylinder should be well oiled before any attempt is made to install the pistons. The engine should be run with more than the ordinary amount of lubricant for several hours after new piston rings have been inserted. On first starting the engine, one may be disappointed in that the compression is even less than that obtained with the old rings. This condition will soon be remedied as the rings become polished and adapt themselves to the contour of the cylinder. WRIST PIN WEAR While wrist pins are usually made of very tough steel, case hardened with the object of wearing out an easily renewable bronze bushing in the upper end of the connecting rod rather than the wrist pin it sometimes happens that these members will be worn so that even the replacement of a new bushing in the connecting rod will not reduce the lost motion and attendant noise due to a loose wrist pin. The only remedy is to fit new wrist pins to the piston. Where the connecting rod is clamped to the wrist pin and that member oscillates in the piston bosses the wear will usually be indicated on bronze bushings which are pressed into the piston bosses. These are easily renewed and after running a reamer through them of the proper size no difficulty should be experienced in replacing either the old or a new wrist pin depending upon the condition of that member. If no bushings are provided, as in alloy pistons, the bosses can sometimes be bored out and thin bushings inserted, though this is not always possible. The alternative is to ream out the bosses and upper end of rod a trifle larger after holes are trued up and fit oversize wrist pins. INSPECTION AND REFITTING OF ENGINE BEARINGS While the engine is dismantled one has an excellent opportunity to examine the various bearing points in the engine crank-case to ascertain if any looseness exists due to depreciation of the bearing surfaces. As will be evident, both main crank-shaft bearings and the lower end of the connecting rods may be easily examined for deterioration. With the rods in place, it is not difficult to feel the amount of lost motion by grasping the connecting rod firmly with the hand and moving it up and down. After the connecting rods have been removed and the propeller hub taken off the crank-shaft to permit of ready handling, any looseness in the main bearing may be detected by lifting up on either the front or rear end of the crank-shaft and observing if there is any lost motion between the shaft journal and the main bearing caps. It is not necessary to take an engine entirely apart to examine the main bearings, as in most forms these may be readily reached by removing the sump. The symptoms of worn main bearings are not hard to identify. If an engine knocks regardless of speed or spark-lever position, and the trouble is not due to carbon deposits in the combustion chamber, one may reasonably surmise that the main bearings have become loose or that lost motion may exist at the connecting rod big ends, and possibly at the wrist pins. The main journals of any well resigned engine are usually proportioned with ample surface and will not wear unduly unless lubrication has been neglected. The connecting rod bearings wear quicker than the main bearings owing to being subjected to a greater unit stress, and it may be necessary to take these up. ADJUSTING MAIN BEARINGS [Illustration: Fig. 187.--Tools and Processes Used in Refitting Engine Bearings.] When the bearings are not worn enough to require refitting the lost motion can often be eliminated by removing one or more of the thin shims or liners ordinarily used to separate the bearing caps from the seat. These are shown at Fig. 187, A. Care must be taken that an even number of shims of the same thickness are removed from each side of the journal. If there is considerable lost motion after one or two shims have been removed, it will be advisable to take out more shims and to scrape the bearing to a fit before the bearing cap is tightened up. It may be necessary to clean up the crank-shaft journals as these may be scored due to not having received clean oil or having had bearings seize upon them. It is not difficult to true up the crank-pins or main journals if the score marks are not deep. A fine file and emery cloth may be used, or a lapping tool such as depicted at Fig. 187, B. The latter is preferable because the file and emery cloth will only tend to smooth the surface while the lap will have the effect of restoring the crank to proper contour. A lapping tool may be easily made, as shown at B, the blocks being of lead or hard wood. As the width of these are about half that of the crank-pin the tool may be worked from side to side as it is rotated. An abrasive paste composed of fine emery powder and oil is placed between the blocks, and the blocks are firmly clamped to the crank-pin. As the lead blocks bed down, the wing nut should be tightened to insure that the abrasive will be held with some degree of pressure against the shaft. A liberal supply of new abrading material is placed between the lapping blocks and crank-shaft from time to time and the old mixture cleaned off with gasoline. It is necessary to maintain a side to side movement of the lapping tool in order to have the process affect the whole width of the crank-pin equally. The lapping is continued until a smooth surface is obtained. If a crank-pin is worn out of true to any extent the only method of restoring it is to have it ground down to proper circular form by a competent mechanic having the necessary machine tools to carry on the work accurately. A crank-pin truing tool that may be worked by hand is shown at Fig. 187, K. After the crank-shaft is trued the next operation is to fit it to the main bearings or rather to scrape these members to fit the shaft journal. In order to bring the brasses closer together, it may be necessary to remove a little metal from the edges of the caps to compensate for the lost motion. A very simple way of doing this is shown at Fig. 187, D. A piece of medium emery cloth is rested on the surface plate and the box or brass is pushed back and forth over that member by hand, the amount of pressure and rapidity of movement being determined by the amount of metal it is necessary to remove. This is better than filing, because the edges will be flat and there will be no tendency for the bearing caps to rock when placed against the bearing seat. It is important to take enough off the edges of the boxes to insure that they will grip the crank tightly. The outer diameter must be checked with a pair of calipers during this operation to make sure that the surfaces remain parallel. Otherwise, the bearing brasses will only grip at one end and with such insufficient support they will quickly work loose, both in the bearing seat and bearing cap. SCRAPING BRASSES TO FIT To insure that the bearing brasses will be a good fit on the trued-up crank-pins or crank-shaft journals, they must be scraped to fit the various crank-shaft journals. The process of scraping, while a tedious one, is not difficult, requiring only patience and some degree of care to do a good job. The surface of the crank-pin is smeared with Prussian blue pigment which is spread evenly over the entire surface. The bearings are then clamped together in the usual manner with the proper bolts, and the crank-shaft revolved several times to indicate the high spots on the bearing cap. At the start of the process of scraping in, the bearing may seat only at a few points as shown at Fig. 187, G. Continued scraping will bring the bearing surface as indicated at H, which is a considerable improvement, while the process may be considered complete when the brass indicates a bearing all over as at I. The high spots are indicated by blue, as where the shaft does not bear on the bearing there is no color. The high spots are removed by means of a scraping tool of the form shown at Fig. 187, F, which is easily made from a worn-out file. These are forged to shape and ground hollow as indicated in the section, and are kept properly sharpened by frequent rubbing on an ordinary oil stone. To scrape properly, the edge of the scraper must be very keen. The straight and curved half-round scrapers, shown at M and N, are used for bearings. The three-cornered scraper, outlined at O, is also used on curved surfaces, and is of value in rounding off the sharp corners. The straight or curved half-round type works well on soft-bearing metals, such as babbitt, or white brass, but on yellow brass or bronze it cuts very slowly, and as soon as the edge becomes dull considerable pressure is needed to remove any metal, this calling for frequent sharpening. When correcting errors on flat or curved surfaces by hand-scraping, it is desirable, of course, to obtain an evenly spotted bearing with as little scraping as possible. When the part to be scraped is first applied to the surface-plate, or to a journal in the case of a bearing, three or four "high" spots may be indicated by the marking material. The time required to reduce these high spots and obtain a bearing that is distributed over the entire surface depends largely upon the way the scraping is started. If the first bearing marks indicate a decided rise in the surface, much time can be saved by scraping larger areas than are covered by the bearing marks; this is especially true of large shaft and engine bearings, etc. An experienced workman will not only remove the heavy marks, but also reduce a larger area; then, when the bearing is tested again, the marks will generally be distributed somewhat. If the heavy marks which usually appear at first are simply removed by light scraping, these "point bearings" are gradually enlarged, but a much longer time will be required to distribute them. The number of times the bearing must be applied to the journal for testing is important, especially when the box or bearing is large and not easily handled. The time required to distribute the bearing marks evenly depends largely upon one's judgment in "reading" these marks. In the early stages of the scraping operation, the marks should be used partly as a guide for showing the high areas, and instead of merely scraping the marked spot the surface surrounding it should also be reduced, unless it is evident that the unevenness is local. The idea should be to obtain first a few large but generally distributed marks; then an evenly and finely spotted surface can be produced quite easily. In fitting brasses when these are of the removable type, two methods may be used. The upper half of the engine base may be inverted on a suitable bench or stand and the boxes fitted by placing the crank-shaft in position, clamping down one bearing cap at a time and fitting each bearing in succession until they bed equally. From that time on the bearings should be fitted at the same time so the shaft will be parallel with the bottom of the cylinders. Considerable time and handling of the heavy crank-shaft may be saved if a preliminary fitting of the bearing brasses is made by clamping them together with a carpenter's wood clamp as shown at Fig. 187, J, and leaving the crank-shaft attached to the bench as shown at C. The brasses are revolved around the crank-shaft journal and are scraped to fit wherever high spots are indicated until they begin to seat fairly. When the brasses assume a finished appearance the final scraping should be carried on with all bearings in place and revolving the crank-shaft to determine the area of the seating. When the brasses are properly fitted they will not only show a full bearing surface, but the shaft will not turn unduly hard if revolved with a moderate amount of leverage. Bearings of white metal or babbitt can be fitted tighter than those of bronze, and care must be observed in supplying lubricant as considerably more than the usual amount is needed until the bearings are run in by several hours of test block work. Before the scraping process is started it is well to chisel an oil groove in the bearing as shown at Fig. 187, L. Grooves are very helpful in insuring uniform distribution of oil over the entire width of bearing and at the same time act as reservoirs to retain a supply of oil. The tool used is a round-nosed chisel, the effort being made to cut the grooves of uniform depth and having smooth sides. Care should be taken not to cut the grooves too deeply, as this will seriously reduce the strength of the bearing bushing. The shape of the groove ordinarily provided is clearly shown at Fig. 187, G, and it will be observed that the grooves do not extend clear to the edge of the bearing, but stop about a quarter of an inch from that point. The hole through which the oil is supplied to the bearing is usually drilled in such a way that it will communicate with the groove. The tool shown at Fig. 187, K, is of recent development, and is known as a "crank-shaft equalizer." This is a hand-operated turning tool, carrying cutters which are intended to smooth down scored crank-pins without using a lathe. The feed may be adjusted by suitable screws and the device may be fitted to crank-pins and shaft-journals of different diameters by other adjusting screws. This device is not hard to operate, being merely clamped around the crank-shaft in the same manner as the lapping tool previously described, and after it has been properly adjusted it is turned around by the levers provided for the purpose, the continuous rotary motion removing the metal just as a lathe tool would. FITTING CONNECTING RODS In the marine type rod, which is the form generally used in airplane engines, one or two bolts are employed at each side and the cap must be removed entirely before the bearing can be taken off of the crank-pin. The tightness of the brasses around the crank-pin can never be determined solely by the adjustment of the bolts, as while it is important that these should be drawn up as tightly as possible, the bearing should fit the shaft without undue binding, even if the brasses must be scraped to insure a proper fit. As is true of the main bearings, the marine form of connecting rod in some engines has a number of liners or shims interposed between the top and lower portions of the rod end, and these may be reduced in number when necessary to bring the brasses closer together. The general tendency in airplane engines is to eliminate shims in either the main or connecting rod bearings, and when wear is noticed the boxes or liners are removed and new ones supplied. The brasses are held in the connecting rod and cap by brass rivets and are generally attached in the main bearing by small brass machine screws. The form of box generally favored is a brass sand casting rich in copper to secure good heat conductivity which forms a backing for a thin layer of white brass, babbitt or similar anti-friction metal. [Illustration: Fig. 188.--Showing Points to Observe When Fitting Connecting Rod Brasses.] In fitting new brasses there are two conditions to be avoided, these being outlined at Fig. 188, B and C. In the case shown at C the light edges of the bushings are in contact, but the connecting rod and its cap do not meet. When the retaining nuts are tightened the entire strain is taken on the comparatively small area of the edges of the bushings which are not strong enough to withstand the strains existing and which flatten out quickly, permitting the bearing to run loose. In the example outlined at B the edges of the brasses do not touch when the connecting rod cap is drawn in place. This is not good practice, because the brasses soon become loose in their retaining member. In the case outlined it is necessary to file off the faces of the rod and cap until these meet, and to insure contact of the edges of the brasses as well. In event of the brasses coming together before the cap and rod make contact, as shown at C, the bearing halves should be reduced at the edges until both the caps and brasses meet against each other or the surfaces of the liners as shown at A. SPRUNG CAM-SHAFT If the cam-shaft is sprung or twisted it will alter the valve timing to such an extent that the smoothness of operation of the engine will be materially affected. If this condition is suspected the cam-shaft may be swung on lathe centers and turned to see if it runs out and can be straightened in any of the usual form of shaft-straightening machines. The shaft may be twisted without being sprung. This can only be determined by supporting one end of the shaft in an index head and the other end on a milling machine center. The cams are then checked to see that they are separated by the proper degree of angularity. This process is one that requires a thorough knowledge of the valve timing of the engine in question, and is best done at the factory where the engine was made. The timing gears should also be examined to see if the teeth are worn enough so that considerable back lash or lost motion exists between them. This is especially important where worm or spiral gears are used. A worn timing gear not only produces noise, but it will cause the time of opening and closing of the engine valves to vary materially. PRECAUTIONS IN REASSEMBLING PARTS When all of the essential components of a power plant have been carefully looked over and cleaned and all defects eliminated, either by adjustment or replacement of worn portions, the motor should be reassembled, taking care to have the parts occupy just the same relative positions they did before the motor was dismantled. As each part is added to the assemblage care should be taken to insure adequate lubrication of all new points of bearing by squirting liberal quantities of cylinder oil upon them with a hand oil can or syringe provided for the purpose. In adjusting the crank-shaft bearings, tighten them one at a time and revolve the shafts each time one of the bearing caps is set up to insure that the newly adjusted bearing does not have undue friction. All retaining keys and pins must be positively placed and it is good practice to cover such a part with lubricant before replacing it because it will not only drive in easier, but the part may be removed more easily if necessary at some future time. If not oiled, rust collects around it. When a piece is held by more than one bolt or screw, especially if it is a casting of brittle material such as cast iron or aluminum, the fastening bolts should be tightened uniformly. If one bolt is tightened more than the rest it is liable to spring the casting enough to break it. Spring washers, check nuts, split pins or other locking means should always be provided, especially on parts which are in motion or subjected to heavy loads. Before placing the cylinder over the piston it is imperative that the slots in the piston rings are spaced equidistant and that the piston is copiously oiled before the cylinder is slipped over it. When reassembling the inlet and exhaust manifolds it is well to use only perfect packings or gaskets and to avoid the use of those that seem to have hardened up or flattened out too much in service. If it is necessary to use new gaskets it is imperative to employ these at all joints on a manifold, because if old and new gaskets are used together the new ones are apt to keep the manifold from bedding properly upon the used ones. It is well to coat the threads of all bolts and screws subjected to heat, such as cylinder head and exhaust manifold retaining bolts, with a mixture of graphite and oil. Those that enter the water jacket should be covered with white or red lead or pipe thread compound. Gaskets will hold better if coated with shellac before the manifold or other parts are placed over them. The shellac fills any irregularities in the joint and assists materially in preventing leakage after the joint is made up and the coating has a chance to set. Before assembling on the shaft, it is necessary to fit the bearings by scraping, the same instructions given for restoring the contour of the main bearings applying just as well in this case. It is apparent that if the crank-pins are not round no amount of scraping will insure a true bearing. A point to observe is to make sure that the heads of the bolts are imbedded solidly in their proper position, and that they are not raised by any burrs or particles of dirt under the head which will flatten out after the engine has been run for a time and allow the bolts to slack off. Similarly, care should be taken that there is no foreign matter under the brasses and the box in which they seat. To guard against this the bolts should be struck with a hammer several times after they are tightened up, and the connecting rod can be hit sharply several times under the cap with a wooden mallet or lead hammer. It is important to pin the brasses in place to prevent movement, as lubrication may be interfered with if the bushing turns round and breaks the correct register between the oil hole in the cap and brasses. Care should be taken in screwing on the retaining nuts to insure that they will remain in place and not slack off. Spring washers should not be used on either connecting rod ends or main bearing nuts, because these sometimes snap in two pieces and leave the nut slack. The best method of locking is to use well-fitting split pins and castellated nuts. TESTING BEARING PARALLELISM It is not possible to give other than general directions regarding the proper degree of tightening for a connecting rod bearing, but as a guide to correct adjustment it may be said that if the connecting rod cap is tightened sufficiently so the connecting rod will just about fall over from a vertical position due to the piston weight when the bolts are fully tightened up, the adjustment will be nearly correct. As previously stated, babbitt or white metal bearings can be set up more tightly than bronze, as the metal is softer and any high spots will soon be leveled down with the running of the engine. It is important that care be taken to preserve parallelism of the wrist-pins and crank-shafts while scraping in bearings. This can be determined in two ways. That shown at Fig. 189, A, is used when the parts are not in the engine assembly and when the connecting rod bearing is being fitted to a mandrel or arbor the same size as the crank-pin. The arbor, which is finished very smooth and of uniform diameter, is placed in two V blocks, which in turn are supported by a level surface plate. An adjustable height gauge may be tried, first at one side of the wrist-pin which is placed at the upper end of the connecting rod, then at the other, and any variation will be easily determined by the degree of tilting of the rod. This test may be made with the wrist-pin alone, or if the piston is in place, a straight edge or spirit level may be employed. The spirit level will readily show any inclination while the straight edge is used in connection with the height gauge as indicated. Of course, the surface plate must be absolutely level when tests are made. When the connecting rods are being fitted with the crank-shaft in place in crank-case, and that member secured in the frame, a steel square may be used as it is reasonable to assume that the wrist-pin, and consequently the piston it carries, should observe a true relation with the top of the engine base. If the piston side is at right angles with the top of the engine base it is reasonable to assume that the wrist-pin and crank-pin are parallel. If the piston is canted to one side or the other, it will indicate that the brasses have been scraped tapering, which would mean considerable heating and undue friction if the piston is installed in the cylinder on account of the pressure against one portion of the cylinder wall. If the degree of canting is not too great, the connecting rods may be sprung very slightly to straighten up the piston, but this is a makeshift that is not advised. The height gauge method shown above may be used instead of the steel square, if desired, because the top of the crank-case is planed or milled true and should be parallel with the center line of the crank-shaft. [Illustration: Fig. 189.--Methods of Testing to Insure Parallelism of Bearings After Fitting.] CAM-SHAFTS AND TIMING GEARS Knocking sounds are also evident if the cam-shaft is loose in its bearings, and also if the cams or timing gears are loose on the shaft. The cam-shaft is usually supported by solid bearings of the removable bushing type, having no compensation for depreciation. If these bearings wear the only remedy is replacement with new ones. In the older makes of cars it was general practice to machine the cams separately and to secure these to the cam-shaft by means of taper pins or keys. These members sometimes loosened and caused noise. In the event of the cams being loose, care should be taken to use new keys or taper pins, as the case may be. If the fastening used was a pin, the hole through the cam-shaft will invariably be slightly oval from wear. In order to insure a tight job, the holes in cam and shaft must be reamed with the next larger size of standard taper reamer and a larger pin driven in. Another point to watch is the method of retaining the cam-shaft gear in place. On some engines the gear is fastened to a flange on the cam-shaft by retaining screws. These are not apt to become loose, but where reliance is placed on a key the cam-shaft gear may often be loose on its supporting member. The only remedy is to enlarge the key slot in both gear and shaft and to fit a larger retaining key. CHAPTER XII Aviation Engine Types--Division in Classes--Anzani Engines-- Canton and Unné Engine--Construction of Gnome Engines-- "Monosoupape" Gnome--German "Gnome" Type--Le Rhone Engine-- Renault Air-Cooled Engine--Simplex Model "A" Hispano-Suiza-- Curtiss Aviation Motors--Thomas-Morse Model 88 Engine-- Duesenberg Engine--Aeromarine Six-Cylinder--Wisconsin Aviation Engines--Hall-Scott Engines--Mercedes Motor--Benz Motor-- Austro-Daimler--Sunbeam-Coatalen. AVIATION ENGINE TYPES Inasmuch as numerous forms of airplane engines have been devised, it would require a volume of considerable size to describe even the most important developments of recent years. As considerable explanatory matter has been given in preceding chapters and the principles involved in internal combustion engine operation considered in detail, a relatively brief review of the features of some of the most successful airplane motors should suffice to give the reader a complete enough understanding of the art so all types of engines can be readily recognized and the advantages and disadvantages of each type understood, as well as defining the constructional features enough so the methods of locating and repairing the common engine and auxiliary system troubles will be fully grasped. Aviation engines can be divided into three main classes. One of the earliest attempts to devise distinctive power plant designs for aircraft involved the construction of engines utilizing a radial arrangement of the cylinders or a star-wise disposition. Among the engines of this class may be mentioned the Anzani, R. E. P. and the Salmson or Canton and Unné forms. The two former are air-cooled, the latter design is water-cooled. Engines of this type have been built in cylinder numbers ranging from three to twenty. While the simple forms were popular in the early days of aviation engine development, they have been succeeded by the more conventional arrangements which now form the largest class. The reason for the adoption of a star-wise arrangement of cylinders has been previously considered. Smoothness of running can only be obtained by using a considerable number of cylinders. The fundamental reason for the adoption of the star-wise disposition is that a better distribution of stress is obtained by having all of the pistons acting on the same crank-pin so that the crank-throw and pin are continuously under maximum stress. Some difficulty has been experienced in lubricating the lower cylinders in some forms of six cylinder, rotary crank, radial engines but these have been largely overcome so they are not as serious in practice as a theoretical consideration would indicate. Another class of engines developed to meet aviation requirements is a complete departure from the preceding class, though when the engines are at rest, it is difficult to differentiate between them. This class includes engines having a star-wise disposition of the cylinders but the cylinders themselves and the crank-case rotate and the crank-shaft remains stationary. The important rotary engines are the Gnome, the Le Rhone and the Clerget. By far the most important classification is that including engines which retain the approved design of the types of power plants that have been so widely utilized in automobiles and which have but slight modifications to increase reliability and mechanical strength and produce a reduction in weight. This class includes the vertical engines such as the Duesenberg and Hall-Scott four-cylinder; the Wisconsin, Aeromarine, Mercedes, Benz, and Hall-Scott six-cylinder vertical engines and the numerous eight- and twelve-cylinder Vee designs such as the Curtiss, Renault, Thomas-Morse, Sturtevant, Sunbeam, and others. ANZANI ENGINES The attention of the mechanical world was first directed to the great possibilities of mechanical flight when Bleriot crossed the English Channel in July, 1909, in a monoplane of his own design and construction, having the power furnished by a small three-cylinder air-cooled engine rated at about 24 horse-power and having cylinders 4.13 inches bore and 5.12 inches stroke, stated to develop the power at about 1600 R.P.M. and weighing 145 pounds. The arrangement of this early Anzani engine is shown at Fig. 190, and it will be apparent that in the main, the lines worked out in motorcycle practice were followed to a large extent. The crank-case was of the usual vertically divided pattern, the cylinders and heads being cast in one piece and held to the crank-case by stud bolts passing through substantial flanges at the cylinder base. In order to utilize but a single crank-pin for the three cylinders it was necessary to use two forked rods and one rod of the conventional type. The arrangement shown at Fig. 190, called for the use of counter-balanced flywheels which were built up in connection with shafts and a crank-pin to form what corresponds to the usual crank-shaft assembly. [Illustration: Fig. 190.--Views Outlining Construction of Three-Cylinder Anzani Aviation Motor.] The inlet valves were of the automatic type so that a very simple valve mechanism consisting only of the exhaust valve push rods was provided. One of the difficulties of this arrangement of cylinders was that the impulses are not evenly spaced. For instance, in the forms where the cylinders were placed 60 degrees apart the space between the firing of the first cylinder and that next in order was 120 degrees crank-shaft rotation, after which there was an interval of 300 degrees before the last cylinder to fire delivered its power stroke. In order to increase the power given by the simple three-cylinder air-cooled engine a six-cylinder water-cooled type, as shown at Figs. 191 and 192, was devised. This was practically the same in action as the three-cylinder except that a double throw crank-shaft was used and while the explosions were not evenly spaced the number of explosions obtained resulted in fairly uniform application of power. [Illustration: Fig. 190a.--Illustrations Depicting Wrong and Right Methods of "Swinging the Stick" to Start Airplane Engine. At Top, Poor Position to Get Full Throw and Get Out of the Way. Below, Correct Position to Get Quick Turn Over of Crank-Shaft and Spring Away from Propeller.] [Illustration: Fig. 191.--The Anzani Six-Cylinder Water-Cooled Aviation Engine.] [Illustration: Fig. 192.--Sectional View of Anzani Six-Cylinder Water-Cooled Aviation Engine.] The latest design of three-cylinder Anzani engine, which is used to some extent for school machines, is shown at Fig. 193. In this, the three-cylinders are symmetrically arranged about the crank-case or 120 degrees apart. The balance is greatly improved by this arrangement and the power strokes occur at equal intervals of 240 degrees of crank-shaft rotation. This method of construction is known as the Y design. By grouping two of these engines together, as outlined at Fig. 194, which gives an internal view, and at Fig. 195, which shows the sectional view, and using the ordinary form of double throw crank-shaft with crank-pins separated by 180 degrees, a six-cylinder radial engine is produced which runs very quietly and furnishes a steady output of power. The peculiarity of the construction of this engine is in the method of grouping the connecting rod about the common crank-pin without using forked rods or the "Mother rod" system employed in the Gnome engines. In the Anzani the method followed is to provide each connecting rod big end with a shoe which consists of a portion of a hollow cylinder held against the crank-pin by split clamping rings. The dimensions of these shoes are so proportioned that the two adjacent connecting rods of a group of three will not come into contact even when the connecting rods are at the minimum relative angle. The three shoes of each group rest upon a bronze sleeve which is in halves and which surrounds the crank-pin and rotates relatively to it once in each crank-shaft revolution. The collars, which are of tough bronze, resist the inertia forces while the direct pressure of the explosions is transmitted directly to the crank-pin bushing by the shoes at the big end of the connecting rod. The same method of construction, modified to some extent, is used in the Le Rhone rotary cylinder engine. [Illustration: Fig. 193.--Three-Cylinder Anzani Air-Cooled Y-Form Engine.] [Illustration: Fig. 194.--Anzani Fixed Crank-Case Engine of the Six-Cylinder Form Utilizes Air Cooling Successfully.] Both cylinders and pistons of the Anzani engines are of cast iron, the cylinders being provided with a liberal number of cooling flanges which are cast integrally. A series of auxiliary exhaust ports is drilled near the base of each cylinder so that a portion of the exhaust gases will flow out of the cylinder when the piston reaches the end of its power stroke. This reduces the temperature of the gases passing around the exhaust valves and prevents warping of these members. Another distinctive feature of this engine design is the method of attaching the Zenith carburetor to an annular chamber surrounding the rear portion of the crank-case from which the intake pipes leading to the intake valves radiate. The magneto is the usual six-cylinder form having the armature geared to revolve at one and one-half times crank-shaft speed. [Illustration: Fig. 195.--Sectional View Showing Internal Parts of Six-Cylinder Anzani Engine, with Starwise Disposition of Cylinders.] [Illustration: Fig. 196.--The Anzani Ten-Cylinder Aviation Engine at the Left, and the Twenty-Cylinder Fixed Type at the Right.] The Anzani aviation engines are also made in ten- and twenty-cylinder forms as shown at Fig. 196. It will be apparent that in the ten-cylinder form explosions will occur every 72 degrees of crank-shaft rotation, while in the twenty-cylinder, 200 horse-power engine at any instant five of the cylinders are always working and explosions are occurring every 36 degrees of crank-shaft rotation. On the twenty-cylinder engine, two carburetors are used and two magnetos, which are driven at two and one-half times crank-shaft speed. The general cylinder and valve construction is practically the same, as in the simpler engines. [Illustration: Fig. 197.--Application of R. E. P. Five-Cylinder Fan-Shape Air-Cooled Motor to Early Monoplane.] CANTON AND UNNÉ ENGINE This engine, which has been devised specially for aviation service, is generally known as the "Salmson" and is manufactured in both France and Great Britain. It is a nine-cylinder water-cooled radial engine, the nine cylinders being symmetrically disposed around the crank-shaft while the nine connecting rods all operate on a common crank-pin in somewhat the same manner as the rods in the Gnome motor. The crank-shaft of the Salmson engine is not a fixed one and inasmuch as the cylinders do not rotate about the crank-shaft it is necessary for that member to revolve as in the conventional engine. The stout hollow steel crank-shaft is in two pieces and has a single throw. The crank-shaft is built up somewhat the same as that of the Gnome engine. Ball bearings are used throughout this engine as will be evident by inspecting the sectional view given at Fig. 199. The nine steel connecting rods are machined all over and are fitted at each end with bronze bushings, the distance between the bearing centers being about 3.25 times crank length. The method of connecting up the rods to the crank-pin is one of the characteristic features of this design. No "mother" rod as supplied in the Gnome engine is used in this type inasmuch as the steel cage or connecting rod carrier is fitted with symmetrically disposed big end retaining pins. Inasmuch as the carrier is mounted on ball bearings some means must be provided of regulating the motion of the carrier as if no means were provided the resulting motion of the pistons would be irregular. [Illustration: Fig. 198.--The Canton and Unné Nine-Cylinder Water-Cooled Radial Engine.] The method by which the piston strokes are made to occur at precise intervals involves a somewhat lengthy and detailed technical explanation. It is sufficient to say that an epicyclic train of gears, one of which is rigidly attached to the crank-case so it cannot rotate is used, while other gears make a connection between the fixed gear and with another gear which is exactly the same size as the fixed gear attached to the crank-case and which is formed integrally with the connecting rod carrier. The action of the gearing is such that the cage carrying the big end retaining pins does not rotate independently of the crank-shaft, though, of course, the crank-shaft or rather crank-pin bearings must turn inside of the big end carrier cage. [Illustration: Fig. 199.--Sectional View Showing Construction of Canton and Unné Water-Cooled Radial Cylinder Engine.] Cylinders of this engine are of nickel steel machined all over and carry water-jackets of spun copper which are attached to the cylinders by brazing. The water jackets are corrugated to permit the cylinder to expand freely. The ignition is similar to that of the fixed crank rotating cylinder engine. An ordinary magneto of the two spark type driven at 1-3/4 times crank-shaft speed is sufficient to ignite the seven-cylinder form, while in the nine-cylinder engines the ignition magneto is of the "shield" type giving four sparks per revolution. The magneto is driven at 1-1/9 times crank-shaft speed. Nickel steel valves are used and are carried in castings or cages which screw into bosses in the cylinder head. Each valve is cam operated through a tappet, push rod and rocker arm, seven cams being used on a seven-cylinder engine and nine cams on the nine-cylinder. One cam serves to open both valves as in its rotation it lifts the tappets in succession and so operates the exhaust and inlet valves respectively. This method of operation involves the same period of intake and exhaust. In normal engine practice the inlet valve opens 12 degrees late and closes 20 degrees late. The exhaust opens 45 degrees early and closes 6 degrees late. This means about 188 degrees in the case of inlet valve and 231 degrees crank-shaft travel for exhaust valves. In the Salmson engine, the exhaust closes and the inlet opens at the outer dead center and the exhaust opens and the inlet closes at about the inner dead center. This engine is also made in a fourteen-cylinder 200 B. H. P. design which is composed of two groups of seven-cylinders, and it has been made in an eighteen-cylinder design of 600 horse-power. The nine-cylinder 130 horse-power has a cylinder bore of 4.73 inches and a stroke of 5.52 inches. Its normal speed of rotation is 1250 R. P. M. Owing to the radial arrangement of the cylinders, the weight is but 4-1/4 pounds per B. H. P. CONSTRUCTION OF EARLY GNOME MOTOR It cannot be denied that for a time one of the most widely used of aeroplane motors was the seven-cylinder revolving air-cooled Gnome, made in France. For a total weight of 167 pounds this motor developed 45 to 47 horse-power at 1,000 revolutions, being equal to 3.35 pounds per horse-power, and has proved its reliability by securing many long-distance and endurance records. The same engineers have produced a nine-cylinder and by combining two single engines a fourteen-cylinder revolving Gnome, having a nominal rating of 100 horse-power, with which world's speed records were broken. A still more powerful engine has been made with eighteen-cylinders. The nine-cylinder "monosoupape" delivers 100 horse-power at 1200 R. P. M., the engine of double that number of cylinders is rated at about 180 horse-power. [Illustration: Fig. 200.--Sectional View Outlining Construction of Early Type Gnome Valve-in-Piston Type Motor.] Except in the number of cylinders and a few mechanical details the fourteen-cylinder motor is identical with the seven-cylinder one; fully three-quarters of the parts used by the assemblers would do just as well for one motor as for the other. Owing to the greater power demands of the modern airplane the smaller sizes of Gnome engines are not used as much as they were except for school machines. There is very little in this motor that is common to the standard type of vertical motorcar engine. The cylinders are mounted radially round a circular crank-case; the crank-shaft is fixed, and the entire mass of cylinders and crank-case revolves around it as outlined at Fig. 200. The explosive mixture and the lubricating oil are admitted through the fixed hollow crank-shaft, passed into the explosion chamber through an automatic intake valve in the piston head in the early pattern, and the spent gases exhausted through a mechanically operated valve in the cylinder head. The course of the gases is practically a radial one. A peculiarity of the construction of the motor is that nickel steel is used throughout. Aluminum is employed for the two oil pump housings; the single compression ring known as the "obdurator" for each piston is made of brass; there are three or four brass bushes; gun metal is employed for certain pins--the rest is machined out of chrome nickel steel. The crank-case is practically a steel hoop, the depth depending on whether it has to receive seven-or fourteen-cylinders; it has seven or fourteen holes bored as illustrated on its circumference. When fourteen or eighteen cylinders are used the holes are bored in two distinct planes, and offset in relation one to the other. The cylinders of the small engine which have a bore of 4-3/10 inches and a stroke of 4-7/10 inches, are machined out of the solid bar of steel until the thickness of the walls is only 1.5 millimeters--.05905 inch, or practically 1/16 inch. Each one has twenty-two fins which gradually taper down as the region of greatest pressure is departed from. In addition to carrying away heat, the fins assist in strengthening the walls of the cylinder. The barrel of the cylinder is slipped into the hole bored for it on the circumference of the crank-case and secured by a locking member in the nature of a stout compression ring, sprung onto a groove on the base of the cylinder within the crank chamber. On each lateral face of the crank chamber are seven holes, drilled right through the chamber parallel with the crank-shaft. Each one of these holes receives a stout locking-pin of such a diameter that it presses against the split rings of two adjacent cylinders; in addition each cylinder is fitted with a key-way. This construction is not always followed, some of the early Gnome engines using the same system of cylinder retention as used on the latest "monosoupape" pattern. The exhaust valve is mounted in the cylinder head, Fig. 201, its seating being screwed in by means of a special box spanner. On the fourteen-cylinder model the valve is operated directly by an overhead rocker arm with a gun metal rocker at its extremity coming in contact with the extremity of the valve stem. As in standard motor car practice, the valve is opened under the lift of the vertical push rod, actuated by the cam. The distinctive feature is the use of a four-blade leaf spring with a forked end encircling the valve stems and pressing against a collar on its extremity. On the seven-cylinder model the movement is reversed, the valve being opened on the downward pull of the push rod, this lifting the outer extremity of the main rocker arm, which tips a secondary and smaller rocker arm in direct contact with the extremity of the valve stem. The springs are the same in each case. The two types are compared at A and B, Fig. 202. [Illustration: Fig. 201.--Sectional View of Early Type Gnome Cylinder and Piston Showing Construction and Application of Inlet and Exhaust Valves.] The pistons, like the cylinders, are machined out of the solid bar of nickel steel, and have a portion of their wall cut away, so that the two adjacent ones will not come together at the extremity of their stroke. The head of the piston is slightly reduced in diameter and is provided with a groove into which is fitted a very light L-section brass split ring; back of this ring and carried within the groove is sprung a light steel compression ring, serving to keep the brass ring in expansion. As already mentioned, the intake valves are automatic, and are mounted in the head of the piston as outlined at Fig. 202, C. The valve seating is in halves, the lower portion being made to receive the wrist-pin and connecting rod, and the upper portion, carrying the valve, being screwed into it. The spring is composed of four flat blades, with the hollowed stem of the automatic valve passing through their center and their two extremities attached to small levers calculated to give balance against centrifugal force. The springs are naturally within the piston, and are lubricated by splash from the crank chamber. They are of a delicate construction, for it is necessary that they shall be accurately balanced so as to have no tendency to fly open under the action of centrifugal force. The intake valve is withdrawn by the use of special tools through the cylinder head, the exhaust valve being first dismounted. [Illustration: Fig. 202.--Details of Old Style Gnome Motor Inlet and Exhaust Valve Construction and Operation.] The fourteen-cylinder motor shown at Fig. 203, has a two-throw crank-shaft with the throws placed at 180 degrees, each one receiving seven connecting rods. The parts are the same as for the seven-cylinder motor, the larger one consisting of two groups placed side by side. For each group of seven-cylinders there is one main connecting rod, together with six auxiliary rods. The main connecting rod, which, like the others, is of H section, has machined with it two L-section rings bored with six holes--51-1/2 degrees apart to take the six other connecting rods. The cage of the main connecting rod carries two ball races, one on either side, fitting onto the crank-pin and receiving the thrust of the seven connecting rods. The auxiliary connecting rods are secured in position in each case by a hollow steel pin passing through the two rings. It is evident that there is a slightly greater angularity for the six shorter rods, known as auxiliary connecting rods, than for the longer main rods; this does not appear to have any influence on the running of the motor. [Illustration: Fig. 203.--The Gnome Fourteen-Cylinder 100 Horse-Power Aviation Engine.] Coming to the manner in which the earliest design exhaust valves are operated on the old style motor, this at first sight appears to be one of the most complicated parts of the motor, probably because it is one in which standard practice is most widely departed from. Within the cylindrical casing bolted to the rear face of the crank-case are seven, thin flat-faced steel rings, forming female cams. Across a diameter of each ring is a pair of projecting rods fitting in brass guides and having their extremities terminating in a knuckle eye receiving the adjustable push rods operating the overhead rocker arms of the exhaust valve. The guides are not all in the same plane, the difference being equal to the thickness of the steel rings, the total thickness being practically 2 inches. Within the female cams is a group of seven male cams of the same total thickness as the former and rotating within them. As the boss of the male cam comes into contact with the flattened portion of the ring forming the female cam, the arm is pushed outward and the exhaust valve opened through the medium of the push-rod and overhead rocker. This construction was afterwards changed to seven male cams and simple valve operating plunger and roller cam followers as shown at Fig. 204. On the face of the crank-case of the fourteen-cylinder motor opposite to the valve mechanism is a bolted-on end plate, carrying a pinion for driving the two magnetos and the two oil pumps, and having bolted to it the distributor for the high-tension current. Each group of seven-cylinders has its own magneto and lubricating pump. The two magnetos and the two pumps are mounted on the fixed platform carrying the stationary crank-shaft, being driven by the pinion on the revolving crank chamber. The magnetos are geared up in the proportion of 4 to 7. Mounted on the end plate back of the driving pinion are the two high-tension distributor plates, each one with seven brass segments let into it and connection made to the plugs by means of plain brass wire. The wire passes through a hole in the plug and is then wrapped round itself, giving a loose connection. [Illustration: Fig. 204.--Cam and Cam-Gear Case of the Gnome Seven-Cylinder Revolving Engine.] [Illustration: Fig. 205.--Diagrams Showing Why An Odd Number of Cylinders is Best for Rotary Cylinder Motors.] A good many people doubtless wonder why rotary engines are usually provided with an odd number of cylinders in preference to an even number. It is a matter of even torque, as can easily be understood from the accompanying diagram. Fig. 205, A, represents a six-cylinder rotary engine, the radial lines indicating the cylinders. It is possible to fire the charges in two ways, firstly, in rotation, 1, 2, 3, 4, 5, 6, thus having six impulses in one revolution and none in the next; or alternately, 1, 3, 5, 2, 4, 6, in which case the engine will have turned through an equal number of degrees between impulses 1 and 3, and 3 and 5, but a greater number between 5 and 2, even again between 2 and 4, 4 and 6, and a less number between 6 and 1, as will be clearly seen on reference to the diagram. Turning to Fig. 205, B, which represents a seven-cylinder engine. If the cylinders fire alternately it is obvious that the engine turns through an equal number of degrees between each impulse, thus, 1, 3, 5, 7, 2, 4, 6, 1, 3, etc. Thus supposing the engine to be revolving, the explosion takes place as each alternate cylinder passes, for instance, the point 1 on the diagram, and the ignition is actually operated in this way by a single contact. [Illustration: Fig. 206.--Simple Carburetor Used On Early Gnome Engines Attached to Fixed Crank-Shaft End.] The crank-shaft of the Gnome, as already explained, is fixed and hollow. For the seven- and nine-cylinder motors it has a single throw, and for the fourteen- and eighteen-cylinder models has two throws at 180 degrees. It is of the built-up type, this being necessary on account of the distinctive mounting of the connecting rods. The carburetor shown at Fig. 206 is mounted at one end of the stationary crank-shaft, and the mixture is drawn in through a valve in the piston as already explained. There is neither float chamber nor jet. In many of the tests made at the factory it is said the motor will run with the extremity of the gasoline pipe pushed into the hollow crank-shaft, speed being regulated entirely by increasing or decreasing the flow through the shut-off valve in the base of the tank. Even under these conditions the motor has been throttled down to run at 350 revolutions without misfiring. Its normal speed is 1,000 to 1,200 revolutions a minute. Castor oil is used for lubricating the engine, the oil being injected into the hollow crank-shaft through slight-feed fittings by a mechanically operated pump which is clearly shown in sectional diagrams at Fig. 207. [Illustration: Fig. 207.--Sectional Views of the Gnome Oil Pump.] The Gnome is a considerable consumer of lubricant, the makers' estimate being 7 pints an hour for the 100 horse-power motor; but in practice this is largely exceeded. The gasoline consumption is given as 300 to 350 grammes per horse-power. The total weight of the fourteen-cylinder motor is 220 pounds without fuel or lubricating oil. Its full power is developed at 1,200 revolutions, and at this speed about 9 horse-power is lost in overcoming air resistance to cylinder rotation. [Illustration: Fig. 208.--Simplified Diagram Showing Gnome Motor Magneto Ignition System.] While the Gnome engine has many advantages, on the other hand, the head resistance offered by a motor of this type is considerable; there is a large waste of lubricating oil due to the centrifugal force which tends to throw the oil away from the cylinders; the gyroscopic effect of the rotary motor is detrimental to the best working of the aeroplane, and moreover it requires about seven per cent. of the total power developed by the motor to drive the revolving cylinders around the shaft. Of necessity, the compression of this type of motor is rather low, and an additional disadvantage manifests itself in the fact that there is as yet no satisfactory way of muffling the rotary type of motor. GNOME "MONOSOUPAPE" TYPE The latest type of Gnome engine is known as the "monosoupape" type because but one valve is used in the cylinder head, the inlet valve in the piston being dispensed with on account of the trouble caused by that member on earlier engines. The construction of this latest type follows the lines established in the earlier designs to some extent and it differs only in the method of charging. The very rich mixture of gas and air is forced into the crank-case through the jet inside the crank-shaft, and enters the cylinder when the piston is at its lowest position, through the half-round openings in the guiding flange and the small holes or ports machined in the cylinder and clearly shown at Fig. 210. The returning piston covers the port, and the gas is compressed and fired in the usual way. The exhaust is through a large single valve in the cylinder head, which gives rise to the name "monosoupape," or single-valve motor, and this valve also remains open a portion of the intake stroke to admit air into the cylinder and dilute the rich gas forced in from the crank-case interior. Aviators who have used the early form of Gnome say that the inlet valve in the piston type was prone to catch on fire if any valve defect materialized, but the "monosoupape" pattern is said to be nearly free of this danger. The bore of the 100 horse-power nine-cylinder engine is 110 mm., the piston stroke 150 mm. Extremely careful machine work and fitting is necessary. In many parts, tolerances of less than .0004" (four ten thousandths of an inch) are all that are allowed. This is about one-sixth the thickness of the average human hair, and in other parts the size must be absolutely standard, no appreciable variation being allowable. The manufacture of this engine establishes new mechanical standards of engine production in this country. Much machine work is needed in producing the finished components from the bar and forging. [Illustration: Fig. 209.--The G. V. Gnome "Monosoupape" Nine-Cylinder Rotary Engine Mounted on Testing Stand.] [Illustration: Fig. 210.--Sectional View Showing Construction of General Vehicle Co. "Monosoupape" Gnome Engine.] The cylinders, for example, are machined from 6 inch solid steel bars, which are sawed into blanks 11 inches in length and weighing about 97 pounds. The first operation is to drill a 2-1/16 inch hole through the center of the block. A heavy-duty drilling machine performs this work, then the block goes to the lathe for further operations. Fig. 211 shows six stages of the progress of a cylinder, a few of the intermediate steps being omitted. These give, however, a good idea of the work done. The turning of the gills, or cooling flanges, is a difficult proposition, owing to the depth of the cut and the thin metal that forms the gills. This operation requires the utmost care of tools and the use of a good lubricant to prevent the metal from tearing as the tools approach their full depth. These gills are only 0.6 mm., or 0.0237 in., thick at the top, tapering to a thickness of 1.4 mm. (0.0553 in.) at the base, and are 16 mm. (0.632 in.) deep. When the machine work is completed the cylinder weighs but 5-1/2 pounds. [Illustration: Fig. 211.--How a Gnome Cylinder is Reduced from Solid Chunk of Steel Weighing 97 Pounds to Finished Cylinder Weighing 5-1/2 Pounds.] GNOME FUEL SYSTEM, IGNITION AND LUBRICATION The following description of the fuel supply, ignition and oiling of the "monosoupape," or single valve Gnome, is taken from "The Automobile." Gasoline is fed to the engine by means of air pressure at 5 pounds per sq. in., which is produced by the air pump on the engine clearly shown at Fig. 210. A pressure gauge convenient to the operator indicates this pressure, and a valve enables the operator to control it. No carburetor is used. The gasoline flows from the tank through a shut-off valve near the operator and through a tube leading through the hollow crank-shaft to a spray nozzle located in the crank-case. There is no throttle valve, and as each cylinder always receives the same amount of air as long as the atmospheric pressure is the same, the output cannot be varied by reducing the fuel supply, except within narrow limits. A fuel capacity of 65 gallons is provided. The fuel consumption is at the rate of 12 U. S. gallons per hour. The high-tension magnetos, with double cam or two break per revolution interrupter, is located on the thrust plate in an inverted position, and is driven at such a speed as to produce nine sparks for every two revolutions; that is, at 2-1/4 times engine speed. A Splitdorf magneto is fitted. There is no distributor on the magneto. The high-tension collector brush of the magneto is connected to a distributor brush holder carried in the bearer plate of the engine. The brush in this brush holder is pressed against a distributor ring of insulating material molded in position in the web of a gear wheel keyed to the thrust plate, which gear serves also for starting the engine by hand. Molded in this ring of insulating material are nine brass contact sectors, connecting with contact screws at the back side of the gear, from which bare wires connect to the spark-plugs. The distributor revolves at engine speed, instead of at half engine speed as on ordinary engines, and the distributor brush is brought into electrical connection with each spark-plug every time the piston in the cylinder in which this spark-plug is located approaches the outer dead center. However, on the exhaust stroke no spark is being generated in the magneto, hence none is produced at the spark-plug. [Illustration: Fig. 212.--The Gnome Engine Cam-Gear Case, a Fine Example of Accurate Machine Work.] Ordinarily the engine is started by turning on the propeller, but for emergency purposes as in seaplanes or for a quick "get away" if landing inadvertently in enemy territory, a hand starting crank is provided. This is supported in bearings secured to the pressed steel carriers of the engine and is provided with a universal joint between the two supports so as to prevent binding of the crank in the bearings due to possible distortion of the supports. The gear on this starting crank and the one on the thrust plate with which it meshes are cut with helical teeth of such hand that the starting pinion is thrown out of mesh as soon as the engine picks up its cycle. A coiled spring surrounds part of the shaft of the starting crank and holds it out of gear when not in use. [Illustration: Fig. 213.--G. V. Gnome "Monosoupape," with Cam-Case Cover Removed to Show Cams and Valve-Operating Plungers with Roller Cam Followers.] Lubricating oil is carried in a tank of 25 gallon capacity, and if this tank has to be placed in a low position it is connected with the air-pressure line, so that the suction of the oil pump is not depended upon to get the oil to the pump. From the bottom of the oil tank a pipe leads to the pump inlet. There are two outlets from the pump, each entering the hollow crank-shaft, and there is a branch from each outlet pipe to a circulation indicator convenient to the operator. One of the oil leads feeds to the housing in the thrust plate containing the two rear ball bearings, and the other lead feeds through the crank-pin to the cams, as already explained. Owing to the effect of centrifugal force and the fact that the oil is not used over again, the oil consumption of a revolving cylinder engine is considerably higher than that of a stationary cylinder engine. Fuel consumption is also somewhat higher, and for this reason the revolving cylinder engine is not so well suited for types of airplanes designed for long trips, as the increased weight of supplies required for such trips, as compared with stationary cylinder type motors, more than offsets the high weight efficiency of the engine itself. But for short trips, and especially where high speed is required, as in single seated scout and battle planes or "avions de chasse," as the French say, the revolving cylinder engine has the advantage. The oil consumption of the Gnome engine is as high as 2.4 gallon per hour. Castor oil is used for lubrication because it is not cut by the gasoline mist present in the engine interior as an oil of mineral derivation would be. GERMAN "GNOME" TYPE ENGINE [Illustration: Fig. 214.--The 50 Horse-Power Rotary Bayerischen Motoren Gesellschaft Engine, a German Adaptation of the Early Gnome Design.] A German adaptation of the Gnome design is shown at Fig. 214. This is known as the Bayerischen Motoren Gesellschaft engine and the type shown is an early design rated at 50 horse-power. The bore is 110 mm., the stroke is 120 mm., and it is designed to run at a speed of 1,200 R. P. M. It is somewhat similar in design to the early Gnome "valve-in-piston" design except that two valves are carried in the piston top instead of one. The valve operating arrangement is different also, as a single four point cam is used to operate the seven exhaust valves. It is driven by epicyclic gearing, the cam being driven by an internal gear machined integrally with it, the cam being turned at 7/8 times the engine speed. Another feature is the method of holding the cylinders on the crank-case. The cylinder is provided with a flange that registers with a corresponding member of the same diameter on the crank-case. A U section, split clamping ring is bolted in place as shown, this holding both flanges firmly together and keeping the cylinder firmly seated against the crank-case flange. The "monosoupape" type has also been copied and has received some application in Germany, but the most successful German airplanes are powered with six-cylinder vertical engines such as the Benz and Mercedes. THE LE RHONE MOTOR The Le Rhone motor is a radial revolving cylinder engine that has many of the principles which are incorporated in the Gnome but which are considered to be an improvement by many foreign aviators. Instead of having but one valve in the cylinder head, as the latest type "monosoupape" Gnome has, the Le Rhone has two valves, one for intake and one for exhaust in each cylinder. By an ingenious rocker arm and tappet rod arrangement it is possible to operate both valves with a single push rod. Inlet pipes communicate with the crank-case at one end and direct the fresh gas to the inlet valve cage at the other. Another peculiarity in the design is the method of holding the cylinders in place. Instead of having a vertically divided crank-case as the Gnome engine has and clamping both halves of the case around the cylinders, the crank-case of the Le Rhone engine is in the form of a cylinder having nine bosses provided with threaded openings into which the cylinders are screwed. A thread is provided at the base of each cylinder and when the cylinder has been screwed down the proper amount it is prevented from further rotation about its own axis by a substantial lock nut which screws down against the threaded boss on the crank-case. The external appearance of the Le Rhone type motor is clearly shown at Fig. 215, while the general features of construction are clearly outlined in the sectional views given at Figs. 216 and 217. [Illustration: Fig. 215--Nine-Cylinder Revolving Le Rhone Type Aviation Engine.] [Illustration: Fig. 216.--Part Sectional Views of Le Rhone Rotary Cylinder Engine, Showing Method of Cylinder Retention, Valve Operation and Novel Crank Disc Assembly.] [Illustration: Fig. 217.--Side Sectional View of Le Rhone Aviation Engine.] [Illustration: Fig. 218.--View Showing Le Rhone Valve Action and Connecting Rod Big End Arrangement.] The two main peculiarities of this motor are the method of valve actuation by two large cams and the distinctive crank-shaft and connecting rod big end construction. The connecting rods are provided with "feet" or shoes on the end which fit into grooves lined with bearing metal which are machined into crank discs revolving on ball bearings and which are held together so that the connecting rod big ends are sandwiched between them by clamping screws. This construction is a modification of that used on the Anzani six-cylinder radial engine. There are three grooves machined in each crank disc and three connecting rod big ends run in each pair of grooves. The details of this construction can be readily ascertained by reference to explanatory diagrams at Figs. 218 and 219, A. Three of the rods which work in the groove nearest the crank-pin are provided with short shoes as shown at Fig. 219, B. The short shoes are used on the rods employed in cylinders number 1, 4, and 7. The set of connecting rods that work in the central grooves are provided with medium-length shoes and actuate the pistons in cylinders numbers 3, 6, and 9. The three rods that work in the outside grooves have still longer shoes and are employed in cylinders numbers 2, 5, and 8. The peculiar profile of the inlet and exhaust cam plates are shown at C, Fig. 219, while the construction of the wrist-pin, wrist-pin bushing and piston are clearly outlined at the sectional view at E. The method of valve actuation is clearly outlined at Fig. 220, which shows an end section through the cam case and also a partial side elevation showing one of the valve operating levers which is fulcrumed at a central point and which has a roller at one end bearing on one cam while the roller or cam follower at the other end bears on the other cam. The valve rocker arm actuating rod is, of course, operated by this simple lever and is attached to it in such a way that it can be pulled down to depress the inlet valve and pushed up to open the exhaust valve. [Illustration: Fig. 219.--Diagrams Showing Important Components of Le Rhone Motor.] [Illustration: Fig. 220.--How the Cams of the Le Rhone Motor Can Operate Two Valves with a Single Push Rod.] A carburetor of peculiar construction is employed in the Le Rhone engine, this being a very simple type as outlined at Fig. 221. It is attached to the threaded end of the hollow crank-shaft by a right and left coupling. The fuel is pumped to the spray nozzle, the opening in which is controlled by a fuel regulating needle having a long taper which is lifted out of the jet opening when the air-regulating slide is moved. The amount of fuel supplied the carburetor is controlled by a special needle valve fitting which combines a filter screen and which is shown at B. In regulating the speed of the Le Rhone engine, there are two possible means of controlling the mixture, one by altering the position of the air-regulating slide, which also works the metering needle in the jet, and the other by controlling the amount of fuel supplied to the spray nozzle through the special fitting provided for that purpose. [Illustration: Fig. 221.--The Le Rhone Carburetor at A and Fuel Supply Regulating Device at B.] In considering the action of this engine one can refer to Fig. 222. The crank O. M. is fixed, while the cylinders can turn about the crank-shaft center O and the piston turns around the crank-pin M, because of the eccentricity of the centers of rotation the piston will reciprocate in the cylinders. This distance is at its maximum when the cylinder is above O and at a minimum when it is above M, and the difference between these two positions is equal to the stroke, which is twice the distance of the crank-throw O, M. The explosion pressure resolves itself into the force F exerted along the line of the connecting rod A, M, and also into a force N, which tends to make the cylinders rotate around point O in the direction of the arrow. An odd number of cylinders acting on one crank-pin is desirable to secure equally spaced explosions, as the basic action is the same as the Gnome engine. [Illustration: Fig. 222.--Diagrams Showing Le Rhone Motor Action and Firing Order.] The magneto is driven by a gear having 36 teeth attached to crank-case which meshes with 16-tooth pinion on armature. The magneto turns at 2.25 times crank-case speed. Two cams, one for inlet, one for exhaust, are mounted on a carrying member and act on nine rocker arms which are capable of giving a push-and-pull motion to the valve-actuating rocker-operating rods. A gear driven by the crank-case meshes with a larger member having internal teeth carried by the cam carrier. Each cam has five profiles and is mounted in staggered relation to the other. These give the nine fulcrumed levers the proper motion to open the inlet and exhaust valves at the proper time. The cams are driven at 45/50 or 9/10 of the motor speed. The cylinder dimensions and timing follows; the weight can be approximated by figuring 3 pounds per horse-power. 80 H.P. 105 M/M bore 4.20" bore. 140 M/M stroke 5.60" stroke. 110 H.P. 112 M/M bore 4.48" bore. 170 M/M stroke 6.80" stroke. Timing--Intake valve opening, lag 18°} 18°} Intake valve closing, lag 35°} 35°} Exhaust valve opening, lead 55°} 110 H.P. 45°} 80 H.P. Exhaust valve closing, lag 5°} 5°} Ignition time advance 26°} 26°} [Illustration: Fig. 223.--Diagram Showing Positions of Piston in Le Rhone Rotary Cylinder Motor.] THE RENAULT AIR-COOLED VEE ENGINE [Illustration: Fig. 224.--Diagrams Showing Valve Timing of Le Rhone Aviation Engine.] [Illustration: Fig. 225.--Diagrams Showing How Cylinder Cooling is Effected in Renault Vee Engines.] Air-cooled stationary engines are rarely used in airplanes, but the Renault Frères of France have for several years manufactured a complete series of such engines of the general design shown at Fig. 225, ranging from a low-powered one developed eight or nine years ago and rated at 40 and 50 horse-power, to later eight-cylinder models rated at 70 horse-power and a twelve-cylinder, or twin six, rated at 90 horse-power. The cylinders are of cast iron and are furnished with numerous cooling ribs which are cast integrally. The cylinder heads are separate castings and are attached to the cylinder as in early motorcycle engine practice, and serve to hold the cylinder in place on the aluminum alloy crank-case by a cruciform yoke and four long hold-down bolts (Fig. 226). The pistons are of cast steel and utilize piston rings of cast iron. The valves are situated on the inner side of the cylinder head, the arrangement being unconventional in that the exhaust valves are placed above the inlet. The inlet valves seat in an extension of the combustion head and are actuated by direct push rod and cam in the usual manner while an overhead gear in which rockers are operated by push rods is needed to actuate the exhaust valves. The valve action is clearly shown in Figs. 226 and 227. The air stream by which the cylinders are cooled is produced by a centrifugal or blower type fan of relatively large diameter which is mounted on the end of a crank-shaft and the air blast is delivered from this blower into an enclosed space between the cylinder from which it escapes only after passing over the cooling fins. In spite of the fact that considerable prejudice exists against air-cooling fixed cylinder engines, the Renault has given very good service in both England and France. [Illustration: Fig. 226.--End Sectional View of Renault Air-Cooled Aviation Engine.] [Illustration: Fig. 227.--Side Sectional View of Renault Twelve-Cylinder Air-Cooled Aviation Engine Crank-Case, Showing Use of Plain and Ball Bearings for Crank-Shaft Support.] As will be seen by the sectional view at Fig. 227, the steel crank-shaft is carried in a combination of plain bearings inside the crank-case and by ball bearings at the ends. Owing to air cooling, special precautions are taken with the lubrication system, though the lubrication is not forced or under high pressure. An oil pump of the gear-wheel type delivers oil from the sump at the bottom of the crank-case to a chamber above, from which the oil flows by gravity along suitable channels to the various main bearings. It flows from the bearings into hollow rings fastened to the crank-webs, and the oil thrown from the whirling connecting rod big ends bathes the internal parts in an oil mist. In the eight-cylinder designs ignition is effected by a magneto giving four sparks per revolution and is accordingly driven at engine speed. In the twelve-cylinder machine two magnetos of the ordinary revolving armature or two-spark type, each supplying six cylinders, are fitted as outlined at Fig. 228. The carburetor is a float feed form. Warm air is supplied for Winter and damp weather by air pipes surrounding the exhaust pipes. The normal speed of the Renault engine is 1,800 R. P. M., but as the propeller is mounted upon an extension of the cam-shaft the normal propeller speed is but half that of the engine, which makes it possible to use a propeller of large diameter and high efficiency. Owing to the air cooling, but low compression may be used, this being about 60 pounds per square inch, which, of course, lowers the mean effective pressure and makes the engine less efficient than water-cooled forms where it is possible to use compression pressure of 100 or more pounds per square inch. The 70 horse-power engine has cylinders with a bore of 3.78 inches and a stroke of 5.52 inches. Its weight is given as 396 pounds, when in running order, which figures 5.7 pounds per horse-power. The same cylinder size is used on the twelve-cylinder 100 horse-power and the stroke is the same. This engine in running order weighs 638 pounds, which figures approximately 6.4 pounds per B. H. P. [Illustration: Fig. 228.--End View of Renault Twelve-Cylinder Engine Crank-Case, Showing Magneto Mounting.] [Illustration: Fig. 229.--Diagram Outlining Renault Twelve-Cylinder Engine Ignition System.] SIMPLEX MODEL "A" HISPANO-SUIZA The Model A is of the water-cooled four-cycle Vee type, with eight cylinders, 4.7245 inch bore by 5.1182 inch stroke, piston displacement 718 cubic inches. At sea-level it develops 150 horse-power at 1,450 R. P. M. It can be run successfully at much higher speeds, depending on propeller design and gearing, developing proportionately increased power. The weight, including carburetor, two magnetos, propeller hub, starting magneto and crank, but without radiator, water or oil or exhaust pipes, is 445 pounds. Average fuel consumption is .5 pound per horse-power hour and the oil consumption at 1,450 R. P. M. is three quarts per hour. The external appearance is shown at Fig. 230. Four cylinders are contained in each block, which is of built-up construction; the water jackets and valve ports are cast aluminum and the individual cylinders heat-treated steel forgings threaded into the bored holes of the aluminum castings. Each block after assembly is given a number of protective coats of enamel, both inside and out, baked on. Coats on the inside are applied under pressure. The pistons are aluminum castings, ribbed. Connecting rods are tubular, of the forked type. One rod bears directly on the crank-pin; the other rod has a bearing on the outside of the one first mentioned. The crank-shaft is of the five-bearing type, very short, stiff in design, bored for lightness and for the oiling system. The crank-shaft extension is tapered for the French standard propeller hub, which is keyed and locked to the shaft. This makes possible instant change of propellers. The case is in two halves divided on the center line of the crank-shaft, the bearings being fitted between the upper and lower sections. The lower half is deep, providing a large oil reservoir and stiffening the engine. The upper half is simple and provides magneto supports on extension ledges of the two main faces. The valves are of large diameter with hollow stems, working in cast iron bushings. They are directly operated by a single hollow cam-shaft located over the valves. The cam-shafts are driven from the crank-shaft by vertical shafts and bevel gears. The cam-shafts, cams and heads of the valve stems are all enclosed in oil-tight removable housings of cast aluminum. [Illustration: Fig. 230.--The Simplex Model A Hispano-Suiza Aviation Engine, a Very Successful Form.] Oiling is by a positive pressure system. The oil is taken through a filter and steel tubes cast in the case to main bearings, through crank-shaft to crank-pins. The fourth main bearing is also provided with an oil lead from the system and through tubes running up the end of each cylinder block, oil is provided for the cam-shafts, cams and bearings. The surplus oil escapes through the end of the cam-shaft where the driving gears are mounted, and with the oil that has gathered in the top casing, descends through the drive shaft and gears to the sump. Ignition is by two eight-cylinder magnetos firing two spark-plugs per cylinder. The magnetos are driven from each of the two vertical shafts by small bevel pinions meshing in bevel gears. The carburetor is mounted between the two cylinder blocks and feeds the two blocks through aluminum manifolds which are partly water-jacketed. The engine can be equipped with a geared hand crank-starting device. STURTEVANT MODEL 5A 140 HORSE-POWER ENGINE These motors are of the eight-cylinder "V" type, four-stroke cycle, water-cooled, having a bore of 4 inches and a stroke of 5-1/2 inches, equivalent to 102 mm. × 140 mm. The normal operating speed of the crank-shaft is 2,000 R. P. M. The propeller shaft is driven through reducing gears which can be furnished in different gear ratios. The standard ratio is 5:3, allowing a propeller speed of 1,200 R. P. M. The construction of the motor is such as to permit of the application of a direct drive. The change from the direct drive to gear drive, or vice versa, can be accomplished in approximately one hour. The cylinders are cast in pairs from an aluminum alloy and are provided with steel sleeves, carefully fitted into each cylinder. A perfect contact is secured between cylinder and sleeve; at the same time a sleeve can be replaced without injury to the cylinder proper. No difficulties due to expansion occur on account of the rapid transmission of heat and the fact that the sleeve is always at higher temperature than the cylinder. A moulded copper asbestos gasket is placed between the cylinder and the head, permitting the cooling water to circulate freely and at the same time insuring a tight joint. The cylinder heads are cast in pairs from an aluminum alloy and contain ample water passages for circulation of cooling water over the entire head. Trouble due to hot valves is thereby eliminated, a most important consideration in the operation of an aeroplane motor. The water jacket of the head corresponds to the water jacket of the cylinders and large openings in both allow the unobstructed circulation of the cooling water. The cylinder heads and cylinders are both held to the base by six long bolts. The valves are located in the cylinder heads and are mechanically operated. The valves and valve springs are especially accessible and of such size as to permit high volumetric efficiency. The valves are constructed of hardened tungsten steel, the heads and stems being made from one piece. The valve rocker arms located on the top of the cylinder are provided with adjusting screws. A check nut enables the adjusting screw to be securely locked in position, once the correct clearance has been determined. The rocker arm bearings are adequately lubricated by a compression grease cup. Cam-rollers are interposed between the cams and the push rods in order to reduce the side thrust on the push rods. A system of double springs is employed which greatly reduces the stress on each spring and insures utmost reliability. A spring of extremely large diameter returns the valve; a second spring located at the cylinder base handles the push rod linkage. These springs, which operate under low stress, are made from the best of steel and are given a special double heat treatment. The pistons are made from a special aluminum alloy; are deeply ribbed in the head for cooling and strength and provided with two piston rings. These pistons are exceedingly light weight in order to minimize vibration and prevent wear on the bearings. The piston pin is made of chrome nickel steel, bored hollow and hardened. It is allowed to turn, both in piston and connecting rod. The piston rings are of special design, developed after years of experimenting in aeronautical engines. The connecting rods are of "H" section, machined all over from forgings of a special air-hardening chrome nickel steel which, after being heat treated has a tensile strength of 280,000 pounds per square inch. They are consequently very strong and yet unusually light, and being machined all over are of absolutely uniform section, which gives as nearly perfect balance as can be obtained. The big ends are lined with white metal and the small ends are bushed with phosphor bronze. The connecting rods are all alike and take their bearings side by side on the crank-pin, the cylinders being offset to permit of this arrangement. The crank-shaft is machined from the highest grade chrome nickel steel, heat treated in order to obtain the best properties of this material. It is 2-1/4 inches in diameter (57 mm.) and bored hollow throughout, insuring maximum strength with minimum weight. It is carried in three large, bronze-backed white metal bearings. A new method of producing these bearings insures a perfect bond between the two metals and eliminates breakage. The base is cast from an aluminum alloy. Great strength and rigidity is combined with light weight. The sides extend considerably below the center line of the crank-shaft, providing an extremely deep section. At all highly stressed points, deep ribs are provided to distribute the load evenly and eliminate bending. The lower half of the base is of cast aluminum alloy of extreme lightness. This collects the lubricating oil and acts as a small reservoir for same. An oil-filtering screen of large area covers the entire surface of the sump. The propeller shaft is carried on two large annular ball bearings driven from the crank-shaft by hardened chrome nickel steel spur gears. These gears are contained within an oil-tight casing integral with the base on the opposite end from the timing gears. A ball-thrust bearing is provided on the propeller shaft to take the thrust of a propeller or tractor, as the case may be. In case of the direct drive a stub shaft is fastened direct to the crank-shaft and is fitted with a double thrust bearing. The cam-shaft is contained within the upper half of the base between the two groups of cylinders, and is supported in six bronze bearings. It is bored hollow throughout and the cams are formed integral with the shaft and ground to the proper shape and finish. An important development in the shape of cams has resulted in a maintained increase of power at high speeds. The gears operating the cam-shaft, magneto, oil and water pumps are contained within an oil-tight casing and operate in a bath of oil. Lubrication is of the complete forced circulating system, the oil being supplied to every bearing under high pressure by a rotary pump of large capacity. This is operated by gears from the crank-shaft. The oil passages from the pump to the main bearings are cast integral with the base, the hollow crank-shaft forming a passage through the connecting rod bearings and the hollow cam-shaft distributing the oil to the cam-shaft bearings. The entire surface of the lower half of the base is covered with a fine mesh screen through which the oil passes before reaching the pump. Approximately one gallon of oil is contained within the base and this is continually circulated through an external tank by a secondary pump operated by an eccentric on the cam-shaft. This also draws fresh oil from the external tank which can be made of any desired capacity. SPECIFICATIONS--MODEL 5A TYPE 8 Horse-power rating, 140 at 2,000 R. P. M. Bore, 4 inches = 102 mm. Stroke, 5-1/2 inches = 140 mm. Number of cylinders, 8. Arrangement of cylinders, "V." Cooling, water. Circulation by centrifugal pump. Cycle, four stroke. Ignition (double), 2 Bosch or Splitdorf magnetos. Carburetor, Zenith duplex. Water jacket manifold. Oiling system, complete forced. Circulating gear pump. Normal crank-shaft speed, 2,000 R. P. M. Propeller shaft, 3/5 crank-shaft speed at normal, 1,200 R. P. M. Stated power at 30" barometer, 140 B. H. P. Stated weight with all accessories but without water, gasoline or oil, 514 pounds = 234 kilos. Weight per B. H. P., 3.7 pounds = 1.68 kilos. Stated weight with all accessories with water, 550 pounds = 250 kilos. Weight per B. H. P. with water, 3.95 pounds = 1.79 kilos. THE CURTISS AVIATION MOTORS The Curtiss OX motor has eight cylinders, 4-inch bore, 5-inch stroke, delivers 90 horse-power at 1,400 turns, and the weight turns out at 4.17 pounds per horse-power. This motor has cast iron cylinders with monel metal jackets, overhead inclined valves operated by means of two rocker arms, push-and-pull rods from the central cam-shaft located in the crank-case. The cam and push rod design is extremely ingenious and the whole valve construction turns out very light. This motor is an evolution from the early Curtiss type motor which was used by Glenn Curtiss when he won the Gordon Bennett Cup at Rheims. A slightly larger edition of this type motor is the OXX-5, as shown at Figs. 231 and 232, which has cylinders 4-1/4 inches by 5 inches, delivers 100 horse-power at 1,400 turns and has the same fuel and oil consumption as the OX type motor, namely, .60 pound of fuel per brake horse-power hour and .03 pound of lubricating oil per brake horse-power hour. [Illustration: Fig. 231.--The Curtiss OXX-5 Aviation Engine is an Eight-Cylinder Type Largely Used on Training Machines.] The Curtiss Company have developed in the last two years a larger-sized motor now known as the V-2, which was originally rated at 160 horse-power and which has since been refined and improved so that the motor gives 220 horse-power at 1,400 turns, with a fuel consumption of 52/100 of a pound per brake horse-power hour and an oil consumption of .02 of a pound per brake horse-power hour. This larger motor has a weight of 3.45 pounds per horse-power and is now said to be giving very satisfactory service. The V-2 motor has drawn steel cylinders, with a bore of 5 inches and a stroke of 7 inches, with a steel water jacket top and a monel metal cylindrical jacket, both of which are brazed on to the cylinder barrel itself. Both these motors use side by side connecting rods and fully forced lubrication. The cam-shafts act as a gallery from which the oil is distributed to the cam-shaft bearings, the main crank-shaft bearings, and the gearing. Here again we find extremely short rods, which, as before mentioned, enables the height and the consequent weight of construction to be very much reduced. For ordinary flying at altitudes of 5,000 to 6,000 feet, the motors are sent out with an aluminum liner, bolted between the cylinder and the crank-case in order to give a compression ratio which does not result in pre-ignition at a low altitude. For high flying, however, these aluminum liners are taken out and the compression volume is decreased to about 18.6 per cent. of the total volume. [Illustration: Fig. 232.--Top and Bottom Views of the Curtiss OXX-5 100 Horse-Power Aviation Engine.] The Curtiss Aeroplane Company announces that it has recently built, and is offering, a twelve-cylinder 5" × 7" motor, which was designed for aeronautical uses primarily. This engine is rated at 250 horse-power, but it is claimed to develop 300 at 1,400 R. P. M. Weights--Motor, 1,125 pounds; radiator, 120 pounds; cooling water, 100 pounds; propeller, 95 pounds. Gasoline Consumption per Horse-power Hour, 6/10 pounds. Oil Consumption per Hour at Maximum Speed--2 pints. Installation Dimensions--Overall length, 84-5/8 inches; overall width, 34-1/8 inches; overall depth, 40 inches; width at bed, 30-1/2 inches; height from bed, 21-1/8 inches; depth from bed, 18-1/2 inches. THOMAS-MORSE MODEL 88 ENGINE The Thomas-Morse Aircraft Corporation of Ithaca, N. Y., has produced a new engine, Model 88, bearing a close resemblance to the earlier model. The main features of that model have been retained; in fact, many parts are interchangeable in the two engines. Supported by the great development in the wide use of aluminum, the Thomas engineers have adopted this material for cylinder construction, which adoption forms the main departure from previous accepted design. The marked tendency to-day toward a higher speed of rotation has been conclusively justified, in the opinion of the Thomas engineers, by the continued reliable performance of engines with crank-shafts operating at speeds near 2,000 revolutions per minute, driving the propeller through suitable gearing at the most efficient speed. High speed demands that the closest attention be paid to the design of reciprocating and rotating parts and their adjacent units. Steel of the highest obtainable tensile strength must be used for connecting rods and piston pins, that they may be light and yet retain a sufficient factor of safety. Piston design is likewise subjected to the same strict scrutiny. At the present day, aluminum alloy pistons operate so satisfactorily that they may be said to have come to stay. The statement often made in the past, that the gearing down of an engine costs more in the weight of reduction gears and propeller shaft than is warranted by the increase in horse-power, is seldom heard to-day. The mean effective pressure remaining the same, the brake horse-power of any engine increases as the speed. That is, an engine delivering 100 brake horse-power at 1,500 revolutions per minute will show 133 brake horse-power at 2,000 revolutions per minute, an increase of 33 brake horse-power. To utilize this increase in horse-power, a matter of some fifteen pounds must be spent in gearing and another fifteen perhaps on larger valves, bearings, etc. Two per cent. may be assumed lost in the gears. In other words, the increase in horse-power due to increasing the speed has been attained at the expense of about one pound per brake horse-power. The advantages of the eight-cylinder engine over the six and twelve, briefly stated, are: lower weight per horse-power, shorter length, simpler and stiffer crank-shaft, cam-shaft and crank-case, and simpler and more direct manifold arrangement. As to torque, the eight is superior to the six, and yet in practice not enough inferior to the twelve to warrant the addition of four more cylinders. It must, however, be recognized that the eight is subject to the action of inherent unbalanced inertia couples, which set up horizontal vibrations, impossible of total elimination. These vibrations are functions of the reciprocating weights, which, as already mentioned, are cut down to the minimum. Vibrations due to the elasticity of crank-case, crank-shaft, etc., can be and are reduced in the Thomas engine to minor quantities by ample webbing of the crank-case and judicious use of metal elsewhere. All things considered, there is actually so little difference to be discerned between the balance of a properly designed eight-cylinder engine and that of a six or twelve as to make a discussion of the pros and cons more one of theory than of practice. The main criticisms of the L head cylinder engine are that it is less efficient and heavier. This is granted, as it relates to cylinders alone. More thorough investigation, however, based on the main desideratum, weight-power ratio, leads us to other conclusions, particularly with reference to high speed engines. The valve gear must not be forgotten. A cylinder cannot be taken completely away from its component parts and judged, as to its weight value, by itself alone. A part away from the whole becomes an item unimportant in comparison with the whole. The valve gear of a high speed engine is a too often overlooked feature. The stamp of approval has been made by high speed automobile practice upon the overhead cam-shaft drive, with valves in the cylinder head operated direct from the cam-shaft or by means of valve lifters or short rockers. The overhead cam-shaft mechanism applied to an eight-cylinder engine calls for two separate cam-shafts carried above and supported by the cylinders in an oil-tight housing, and driven by a series of spur gears or bevels from the crank-shaft. It is patent that this valve gearing is heavy and complicated in comparison with the simple moving valve units of the L head engine, which are operated from one single cam-shaft, housed rigidly in the crank-case. The inherently lower volumetric efficiency of the L head engine is largely overcome by the use of a properly designed head, large valves and ample gas passages. Again, the customary use of a dual ignition system gives to the L head a relatively better opportunity for the advantageous placing of spark-plugs, in order that better flame propagation and complete combustion may be secured. [Illustration: Fig. 233.--End View of Thomas-Morse 150 Horse-Power Aluminum Cylinder Aviation Motor Having Detachable Cylinder Heads.] The Thomas Model 88 engine is 4-1/8 inch bore and 5-1/2 inch stroke. The cylinders and cylinder heads are of aluminum, and as steel liners are used in the cylinders the pistons are also made of aluminum. This engine is actually lighter than the earlier model of less power. It weighs but 525 pounds, with self-starter. The general features of design can be readily ascertained by study of the illustrations: Fig. 233, which shows an end view; Fig. 234, which is a side view, and Fig. 235, which outlines the reduction gear-case and the propeller shaft supporting bearings. [Illustration: Fig. 234.--Side View of Thomas-Morse High Speed 150 Horse-Power Aviation Motor with Geared Down Propeller Drive.] SIXTEEN-VALVE DUESENBERG ENGINE [Illustration: Fig. 235.--The Reduction Gear-Case of Thomas-Morse 150 Horse-Power Aviation Motor, Showing Ball Bearing and Propeller Drive Shaft Gear.] This engine is a four-cylinder, 4-3/4" × 7", 125 horse-power at 2,100 R. P. M. of the crank-shaft and 1,210 R. P. M. of the propeller. Motors are sold on above rating; actual power tests prove this motor capable of developing 140 horse-power at 2,100 R. P. M. of the motor. The exact weight with magneto, carburetor, gear reduction and propeller hub, as illustrated, 509 pounds; without gear reduction, 436 pounds. This motor has been produced as a power plant weighing 3.5 pounds per horse-power, yet nothing has been sacrificed in rigidity and strength. At its normal speed it develops 1 horse-power for every 3.5 cubic inches piston displacement. Cylinders are semi-steel, with aluminum plates enclosing water jackets. Pistons specially ribbed and made of Magnalite aluminum compound. Piston rings are special Duesenberg design, being three-piece rings. Valves are tungsten steel, 1-15/16" inlets and 2" exhausts, two of each to each cylinder. Arranged horizontally in the head, allowing very thorough water-jacketing. Inlet valves in cages. Exhaust valves, seating directly in the cylinder head, are removable through the inlet valve holes. Valve stems lubricated by splash in the valve action covers. Valve rocker arms forged with cap screw and nut at upper end to adjust clearance. Entirely enclosed by aluminum housing, as is entire valve mechanism. Connecting rods are tubular, chrome nickel steel, light and strong. Crank-shaft is one-piece forging, hollow bored, 2-1/2-inch diameter at main bearings. Connecting rod bearings, 2-1/4-inch diameter, 3 inches long. Front main bearing, 3-1/2 inches long; intermediate main bearing, 3-1/2 inches long; rear main bearing, 4 inches long. Crank-case of aluminum, barrel type, oil pan on bottom removable. Hand hole plates on both sides. Strongly webbed. The oiling system of this sixteen-valve Duesenberg motor is one of its vital features. An oil pump located in the base and submerged in oil forces oil through cored passages to the three main bearings, then through tubes under each connecting rod into which the rod dips. The oil is thrown off from these and lubricates every part of the motor. This constitutes the main oiling system; it is supplemented by a splash system, there being a trough under each connecting rod into which the rod slips. The oil is returned to the main supply sump by gravity, where it is strained and re-used. Either system is in itself sufficient to operate the motor. A pressure gauge is mounted for observation on a convenient part of the system. A pressure of approximately 25 pounds is maintained by the pressure system, which insures efficient lubrication at all speeds of the motor. The troughs under the connecting rods are so constructed that no matter what the angle of flight may be, oil is retained in each individual trough so that each connecting rod can dip up its supply of oil at each revolution. AEROMARINE SIX-CYLINDER VERTICAL MOTOR [Illustration: Fig. 236.--The Six-Cylinder Aeromarine Engine.] These motors are four-stroke cycle, six-cylinder vertical type, with cylinder 4-5/16" bore by 5-1/8" stroke. The general appearance of this motor is shown in illustration at Fig. 236. This engine is rated at 85-90 horse-power. All reciprocating and revolving parts of this motor are made of the highest grades of steel obtainable as are the studs, nuts and bolts. The upper and lower parts of crank-case are made of composition aluminum casting. Lower crank-case is made of high grade aluminum composition casting and is bolted directly to the upper half. The oil reservoir in this lower half casting provides sufficient oil capacity for five hours' continuous running at full power. Increased capacity can be provided if needed to meet greater endurance requirements. Oil is forced under pressure to all bearings by means of high-pressured duplex-geared pumps. One side of this pump delivers oil under pressure to all the bearings, while the other side draws the oil from the splash case and delivers it to the main sump. The oil reservoir is entirely separate from the crank-case chamber. Under no circumstances will oil flood the cylinder, and the oiling system is not affected in any way by any angle of flight or position of motor. An oil pressure gauge is placed on instrument board of machine, which gives at all times the pressure in oil system, and a sight glass at lower half of case indicates the amount of oil contained. The oil pump is external on magneto end of motor, and is very accessible. An external oil strainer is provided, which is removable in a few minutes' time without the loss of any oil. All oil from reservoir to the motor passes through this strainer. Pressure gauge feed is also attached and can be piped to any part of machine desired. The cylinders are made of high-grade castings and are machined and ground accurately to size. Cylinders are bolted to crank-case with chrome nickel steel studs and nuts which securely lock cylinder to upper half of crank-case. The main retaining cylinder studs go through crank-case and support crank-shaft bearings so that crank-shaft and cylinders are tied together as one unit. Water jackets are of copper, 1/16" thick, electrically deposited. This makes a non-corrosive metal. Cooling is furnished by a centrifugal pump, which delivers 25 gallons per minute at 1,400 R. P. M. Pistons are made cast iron, accurately machined and ground to exact dimensions, which are carefully balanced. Piston rings are semi-steel rings of Aeromarine special design. Connecting rods are of chrome nickel steel, H-section. Crank-shaft is made of chrome nickel steel, machined all over, and cut from solid billet, and is accurately balanced through the medium of balance weights being forged integral with crank. It is drilled for lightness and plugged for force feed lubrication. There are seven main bearings to crank-shaft. All bearings are of high-grade babbitt, die cast, and are interchangeable and easily replaced. The main bearings of the crank-shaft are provided with a single groove to take oil under pressure from pressure tube which is cast integral with case. Connecting rod bearings are of the same type. The gudgeon pin is hardened, ground and secured in connecting rod, and is allowed to work in piston. Cam-shaft is of steel, with cams forged integral, drilled for lightness and forced-feed lubrication, and is case-hardened. The bearings of cam-shaft are of bronze. Magneto, two high-tension Bosch D. U. 6. The intake manifold for carburetors are aluminum castings and are so designed that each carburetor feeds three cylinders, thereby insuring easy flow of vapor at all speeds. Weight, 420 pounds. [Illustration: Fig. 237.--The Wisconsin Aviation Engine, at Top, as Viewed from Carburetor Side. Below, the Exhaust Side.] WISCONSIN AVIATION ENGINES [Illustration: Fig. 238.--Dimensioned End Elevation of Wisconsin Six Motor.] The new six-cylinder Wisconsin aviation engines, one of which is shown at Fig. 237, are of the vertical type, with cylinders in pairs and valves in the head. Dimensioned drawings of the six-cylinder vertical type are given at Figs. 238 and 239. The cylinders are made of aluminum alloy castings, are bored and machined and then fitted with hardened steel sleeves about 1/16 inch in thickness. After these sleeves have been shrunk into the cylinders, they are finished by grinding in place. Gray iron valve seats are cast into the cylinders. The valve seats and cylinders, as well as the valve ports, are entirely surrounded by water jackets. The valves set in the heads at an angle of 25° from the vertical, are made of tungsten steel and are provided with double springs, the outer or main spring and the inner or auxiliary spring, which is used as a precautionary measure to prevent a valve falling into the cylinder in remote case of a main spring breaking. The cam-shaft is made of one solid forging, case-hardened. It is carried in an aluminum housing bolted to the top of the cylinders. This housing is split horizontally, the upper half carrying the chrome vanadium steel rocker levers. The lower half has an oil return trough cast integral, into which the excess oil overflows and then drains back to the crank-case. Small inspection plates are fitted over the cams and inner ends of the cam rocker levers. The cam-shaft runs in bronze bearings and the drive is through vertical shaft and bevel gears. [Illustration: Fig. 239.--Dimensioned Side Elevation of Wisconsin Six Motor.] The crank-case is made of aluminum, the upper half carrying the bearings for the crank-shaft. The lower half carries the oil sump in which all of the oil except that circulating through the system at the time is carried. The crank-shaft is made of chrome vanadium steel of an elastic limit of 115,000 pounds. The crank-pins and ends of the shaft are drilled for lightness and the cheeks are also drilled for oil circulation. The crank-shaft runs in bronze-backed, Fahrig metal-lined bearings, four in number. A double thrust bearing is also provided, so that the motor may be used either in a tractor or pusher type of machine. Outside of the thrust bearing an annular ball bearing is used to take the radial load of the propeller. The propeller is mounted on a taper. At the opposite end of the shaft a bevel gear is fitted which drives the cam-shaft, through a vertical shaft, and also drives the water and oil pumps and magnetos. All gears are made of chrome vanadium steel, heat-treated. The connecting rods are tubular and machined from chrome vanadium steel forgings. Oil tubes are fitted to the rods which carry the oil up to the wrist-pins and pistons. The rods complete with bushings weigh 5-1/2 pounds each. The pistons are made of aluminum alloy and are very light and strong, weighing only 2 pounds 2 ounces each. Two leak-proof rings are fitted to each piston. The wrist-pins are hollow, of hardened steel, and are free to turn either in the piston or the rod. A bronze bushing is fitted in the upper end of the rod, but no bushing is fitted in the pistons, the hardened steel wrist-pins making an excellent bearing in the aluminum alloy. [Illustration: Fig. 240.--Power, Torque and Efficiency Curves of Wisconsin Aviation Motor.] The water circulation is by centrifugal pump, which is mounted at the lower end of the vertical shaft. The water is pumped through brass pipes to the lower end of the cylinder water jackets and leaves the upper end of the jackets just above the exhaust valves. The lubricating system is one of the main features of the engines, being designed to work with the motor at any angle. The oil is carried in the sump, from where it is taken by the oil circulating pump through a strainer and forced through a header, extending the full length of the crank-case, and distributed to the main bearings. From the main bearings it is forced through the hollow crank-shaft to the connecting rod big ends and then through tubes on the rods to wrist-pins and pistons. Another lead takes oil from the main header to the cam-shaft bearings. The oil forced out of the ends of the cam-shaft bearings fills pockets under the cams and in the cam rocker levers. The excess flows back through pipes and through the train of gears to the crank-case. A strainer is fitted at each end of the crank-case, through which the oil is drawn by separate pumps and returned to the sump. Either one of these pumps is large enough to take care of all of the return oil, so that the operation is perfect whether the motor is inclined up or down. No splash is used in the crank-case, the system being a full force feed. An oil level indicator is provided, showing the amount of oil in the sump at all times. The oil pressure in these motors is carried at ten pounds, a relief valve being fitted to hold the pressure constant. [Illustration: Fig. 241.--Timing Diagram, Wisconsin Aviation Engine.] Ignition is by two Bosch magnetos, each on a separate set of plugs fired simultaneously on opposite sides of the cylinders. Should one magneto fail, the other would still run the engine at only a slight loss in power. The Zenith double carburetor is used, three cylinders being supplied by each carburetor. This insures a higher volumetric efficiency, which means more power, as there is no overlapping of inlet valves whatever by this arrangement. All parts of these motors are very accessible. The water and oil pumps, carburetors, magnetos, oil strainer or other parts can be removed without disturbing other parts. The lower crank-case can be removed for inspection or adjustment of bearings, as the crank-shaft and bearing caps are carried by the upper half. The motor supporting lugs are also part of the upper crank-case. The six-cylinder motor, without carburetors or magnetos, weighs 547 pounds. With carburetor and magnetos, the weight is 600 pounds. The weight of cooling water in the motor is 38 pounds. The sump will carry 4 gallons of oil, or about 28 pounds. A radiator can be furnished suitable for the motor, weighing 50 pounds. This radiator will hold 3 gallons of water or about 25 pounds. The motor will drive a two-blade, 8 feet diameter by 6.25 feet pitch Paragon propeller 1400 revolutions per minute, developing 148 horse-power. The weight of this propeller is 42 pounds. This makes a total weight of motor, complete with propeller, radiator filled with water, but without lubricating oil, 755 pounds, or about 5.1 pounds per horse-power for complete power plant. The fuel consumption is .5 pound per horse-power per hour. The lubricating oil consumption is .0175 pound per horse-power per hour, or a total of 2.6 pounds per hour at 1400 revolutions per minute. This would make the weight of fuel and oil, per hour's run at full power at 1400 revolutions per minute, 76.6 pounds. PRINCIPAL DIMENSIONS Following are the principal dimensions of the six-cylinder motor: Bore 5 inches. Stroke 6-1/2 inches. Crank-shaft diameter throughout 2 inches. Length of crank-pin and main bearings 3-1/2 inches. Diameter of valves 3 inches (2-3/4 inches clear). Lift of valves 1/2 inch. Volume of compression space 22 per cent. of total. Diameter of wrist-pins 1-3/16 inches. Firing order 1-4-2-6-3-5. The horse-power developed at 1200 revolutions per minute is 130, at 1300 revolutions per minute 140, at 1400 revolutions per minute 148. 1400 is the maximum speed at which it is recommended to run these motors. TWELVE-CYLINDER ENGINE A twelve-cylinder V-type engine illustrated, is also being built by this company, similar in dimensions of cylinders to the six. The principal differences being in the drive to cam-shaft, which is through spur gears instead of bevel. A hinged type of connecting rod is used which does not increase the length of the motor and, at the same time, this construction provides for ample bearings. A double centrifugal water pump is provided for this motor, so as to distribute the water uniformly to both sets of cylinders. Four magnetos are used, two for each set of six cylinders. The magnetos are very accessibly located on a bracket on the spur gear cover. The carburetors are located on the outside of the motors, where they are very accessible, while the exhaust is in the center of the valley. The crank-shaft on the twelve is 2-1/2 inches in diameter and the shaft is bored to reduce weight. Dimensioned drawings of the twelve-cylinder engine are given at Figs. 242 and 243 and should prove useful for purposes of comparison with other motors. HALL-SCOTT AVIATION ENGINES The following specifications of the Hall-Scott "Big Four" engines apply just as well to the six-cylinder vertical types which are practically the same in construction except for the structural changes necessary to accommodate the two extra cylinders. Cylinders are cast separately from a special mixture of semi-steel, having cylinder head with valve seats integral. Special attention has been given to the design of the water jacket around the valves and head, there being two inches of water space above same. The cylinder is annealed, rough machined, then the inner cylinder wall and valve seats ground to mirror finish. This adds to the durability of the cylinder, and diminishes a great deal of the excess friction. [Illustration: Fig. 242.--Dimensioned End View of Wisconsin Twelve-Cylinder Airplane Motor.] Great care is taken in the casting and machining of these cylinders, to have the bore and walls concentric with each other. Small ribs are cast between outer and inner walls to assist cooling as well as to transfer stresses direct from the explosion to hold-down bolts which run from steel main bearing caps to top of cylinders. The cylinders are machined upon the sides so that when assembled on the crank-case with grooved hold-down washers tightened, they form a solid block, greatly assisting the rigidity of crank-case. [Illustration: Fig. 243.--Dimensioned Side Elevation of Wisconsin Twelve-Cylinder Airplane Motor.] The connecting rods are very light, being of the I beam type, milled from a solid Chrome nickel die forging. The caps are held on by two 1/2"-20 thread Chrome nickel through bolts. The rods are first roughed out, then annealed. Holes are drilled, after which the rods are hardened and holes ground parallel with each other. The piston end is fitted with a gun metal bushing, while the crank-pin end carries two bronze serrated shells, which are tinned and babbitted hot, being broached to harden the babbitt. Between the cap and rod proper are placed laminated shims for adjustment. Crank-cases are cast of the best aluminum alloy, hand scraped and sand blasted inside and out. The lower oil case can be removed without breaking any connections, so that the connecting rods and other working parts can readily be inspected. An extremely large strainer and dirt trap is located in the center and lowest point of the case, which is easily removed from the outside without disturbing the oil pump or any working parts. A Zenith carburetor is provided. Automatic valves and springs are absent, making the adjustment simple and efficient. This carburetor is not affected by altitude to any appreciable extent. A Hall-Scott device, covered by U. S. Patent No. 1,078,919, allows the oil to be taken direct from the crank-case and run around the carburetor manifold, which assists carburetion as well as reduces crank-case heat. Two waterproof four-cylinder Splitdorf "Dixie" magnetos are provided. Both magneto interruptors are connected to a rock shaft integral with the motor, making outside connections unnecessary. It is worthy of note that with this independent double magneto system, one complete magneto can become inoperative, and still the motor will run and continue to give good power. The pistons as provided in the A-7 engines are cast from a mixture of steel and gray iron. These are extremely light, yet provided with six deep ribs under the arch head, greatly aiding the cooling of the piston as well as strengthening it. The piston pin bosses are located very low in order to keep the heat from the piston head away from the upper end of the connecting rod, as well as to arrange them at the point where the piston fits the cylinder best. Three 1/4" rings are carried. The pistons as provided in the A-7a engines are cast from aluminum alloy. Four 1/4" rings are carried. In both piston types a large diameter, heat treated, Chrome nickel steel wrist-pin is provided, assembled in such a way as to assist the circular rib between the wrist-pin bosses to keep the piston from being distorted from the explosions. The oiling system is known as the high pressure type, oil being forced to the under side of the main bearings with from 5 to 30 points pressure. This system is not affected by extreme angles obtained in flying, or whether the motor is used for push or pull machines. A large gear pump is located in the lowest point of the oil sump, and being submerged at all times with oil, does away with troublesome stuffing boxes and check valves. The oil is first drawn from the strainer in oil sump to the long jacket around the intake manifold, then forced to the main distributor pipe in crank-case, which leads to all main bearings. A bi-pass, located at one end of the distributor pipe, can be regulated to provide any pressure required, the surplus oil being returned to the case. A special feature of this system is the dirt, water and sediment trap, located at the bottom of the oil sump. This can be removed without disturbing or dismantling the oil pump or any oil pipes. A small oil pressure gauge is provided, which can be run to the aviator's instrument board. This registers the oil pressure, and also determines its circulation. The cooling of this motor is accomplished by the oil as well as the water, this being covered by patent No. 1,078,919. This is accomplished by circulating the oil around a long intake manifold jacket; the carburetion of gasoline cools this regardless of weather conditions. Crank-case heat is therefore kept at a minimum. The uniform temperature of the cylinders is maintained by the use of ingenious internal outlet pipes, running through the head of each of the six-cylinders, rubber hose connections being used so that any one of the cylinders may be removed without disturbing the others. Slots are cut in these pipes so that cooler water is drawn directly around the exhaust valves. Extra large water jackets are provided upon the cylinders, two inches of water space is left above the valves and cylinder head. The water is circulated by a large centrifugal pump insuring ample circulation at all speeds. The crank-shaft is of the five bearing type, being machined from a special heat treated drop forging of the highest grade nickel steel. The forging is first drilled, then roughed out. After this the shaft is straightened, turned down to a grinding size, then ground accurately to size. The bearing surfaces are of extremely large size, over-size, considering general practice in the building of high speed engines of similar bore and stroke. The crank-shaft bearings are 2" in diameter by 1-15/16" long, excepting the rear main bearing, which is 4-3/8" long, and front main bearing, which is 2-3/16" long. Steel oil scuppers are pinned and sweated onto the webs of the shaft, which allows of properly oiling the connecting rod bearings. Two thrust bearings are installed on the propeller end of the shaft, one for pull and the other for push. The propeller is driven by the crank-shaft flange, which is securely held in place upon the shaft by six keys. These drive an outside propeller flange, the propeller being clamped between them by six through bolts. The flange is fitted to a long taper on crank-shaft. This enables the propeller to be removed without disturbing the bolts. Timing gears and starting ratchets are bolted to a flange turned integral with shaft. The cam-shaft is of the one piece type, air pump eccentric, and gear flange being integral. It is made from a low carbon specially heat treated nickel forging, is first roughed out and drilled entire length; the cams are then formed, after which it is case hardened and ground to size. The cam-shaft bearings are extra long, made from Parson's White Brass. A small clutch is milled in gear end of shaft to drive revolution indicator. The cam-shaft is enclosed in an aluminum housing bolted directly on top of all six cylinders, being driven by a vertical shaft in connection with bevel gears. This shaft, in conjunction with rocker arms, rollers and other working parts, are oiled by forcing the oil into end of shaft, using same as a distributor, allowing the surplus supply to flow back into the crank-case through hollow vertical tube. This supply oils the magneto and pump gears. Extremely large Tungsten valves, being one-half the cylinder diameter, are seated in the cylinder heads. Large diameter oil tempered springs held in tool steel cups, locked with a key, are provided. The ports are very large and short, being designed to allow the gases to enter and exhaust with the least possible resistance. These valves are operated by overhead one piece cam-shaft in connection with short Chrome nickel rocker arms. These arms have hardened tool steel rollers on cam end with hardened tool steel adjusting screws opposite. This construction allows accurate valve timing at all speeds with least possible weight. CENSORED GERMAN AIRPLANE MOTORS In a paper on "Aviation Motors," presented by E. H. Sherbondy before the Cleveland section of the S. A. E. in June, 1917, the Mercedes and Benz airplane motor is discussed in some detail and portions of the description follow. [Illustration: Fig. 244.--Side and End Sectional Views of Four-Cylinder Argus Engine, a German 100 Horse-Power Design Having Bore and Stroke of 140 mm., or 5.60 inches, and Developing Its Power at 1,368 R.P.M. Weight, 350 Pounds.] MERCEDES MOTOR The 150 horse-power six-cylinder Mercedes motor is 140 millimeters bore and 160 millimeters stroke. The Mercedes company started with smaller-sized cylinders, namely 100 millimeters bore and 140 millimeters stroke, six-cylinders. The principal features of the design are forged steel cylinders with forged steel elbows for gas passages, pressed steel water jackets, which when welded together forms the cylinder assembly, the use of inclined overhead valves operated by means of an overhead cam-shaft through rocker arms which multiply with the motion of the cam. By the use of steel cylinders, not only is the weight greatly reduced, but certain freedom from distortion through unequal sections, leaks and cracks are entirely avoided. The construction is necessarily very expensive. It is certainly a sound job. In the details of this construction there are a number of important things, such as finished gas passages, water-cooled valve guides and a very small mass of metal, which is water-cooled, surrounding the spark-plug. Of course, it is necessary to use very high compression in aviation motors in order to secure high power and economy and owing to the fact that aviation motors are worked at nearly their maximum, the heat flow through the cylinder, piston, and valves is many times higher than that encountered in automobile motors. It has been found necessary to develop special types of pistons to carry the heat from the center of the head in order to prevent pre-ignition. In the Mercedes motor the pistons have a drop forged steel head which includes the piston boss and this head is screwed into a cast iron skirt which has been machined inside to secure uniform wall thickness. CENSORED [A] Piston Displacement (Cubic Inches) [B] Weight of Engine with Carburetor and Ignition [C] Gas Consumption ===========+======+======+======+=======+====+======+====+================= Maker's |Number|Bore |Stroke| | | | | Name | of |(In- |(In- | | | | | and Model | Cyl. |ches) |ches) | [A] |H.P.|R.P.M.| [B]| [C] -----------+------+------+------+-------+----+------+----+----------------- Aeromarine | 6 |4-1/2 |5-1/8 | 449 | 85| 1400 | 440| ... -----------+------+------+------+-------+----+------+----+----------------- Aeromarine | 12 |4-5/16|5-1/8 | ... | ...| ... | 750| ... D-12 | | | | | | | | -----------+------+------+------+-------+----+------+----+----------------- Curtiss OX | 8 |4 |5 | 502.6 | 90| 1400 | 375| ... -----------+------+------+------+-------+----+------+----+----------------- Curtiss | 8 |4-1/4 |5 | 567.5 | 100| 1400 | 423| ... OXX-2 | | | | | | | | -----------+------+------+------+-------+----+------+----+----------------- Curtiss V-2| 8 |5 |7 |1100 | 200| 1400 | 690| ... -----------+------+------+------+-------+----+------+----+----------------- CENSORED -----------+------+------+------+-------+----+------+----+----------------- General Ve-| 9 |4.33 |5.9 | 848 | 100| 1200 | 272|12 gals/hour at hicle Gnome Mono | | | | | | |rated H.P. -----------+------+------+------+-------+----+------+----+----------------- Gyro K | 7 |4-1/2 |6 | ... | 90| 1250| 215|8 gals/hour at Rotary, Le Rhone Type | | | | | |rated H.P. -----------+------+------+------+-------+----+------+----+----------------- Gyro L | 9 |4-1/2 |6 | 859 | 100| 1200| 285|10 gals/hour at Rotary, Le Rhone Type | | | | | |rated H.P. -----------+------+------+------+-------+----+------+----+----------------- Hall-Scott | 4 |5 |7 | 550 | 90-| 1400| 410| ... A-7 | | | | | 100| | | -----------+------+------+------+-------+----+------+----+----------------- Hall-Scott | 6 |5 |7 | 825 | 125| 1300| 592| ... A-5 | | | | | | | | -----------+------+------+------+-------+----+------+----+----------------- Hispano- | 8 |4-5/8 |5 | 672 | 154| 1500| 455| ... Suiza | | | | | | | | -----------+------+------+------+-------+----+------+----+----------------- Knox Motors| 12 |4-3/4 |7 |1555 | 300| 1800|1425|31.5 gals/hour Co. | | | | | | | | -----------+------+------+------+-------+----+------+----+----------------- Maximotor | 6 |4-1/2 |5 | 477 | 85| 1600| 340| ... A-6 | | | | | | | | -----------+------+------+------+-------+----+------+----+----------------- Maximotor | 6 |5 |6 | 706.8 | 115| 1600| 385| ... B-6 | | | | | | | | -----------+------+------+------+-------+----+------+----+----------------- Maximotor | 8 |4-1/2 |5 | 636 | 115| 1600| 420| ... A-8 | | | | | | | | -----------+------+------+------+-------+----+------+----+----------------- Packard 12 | 12 |4 |6 | 903 | 225| 2100| 800| ... -----------+------+------+------+-------+----+------+----+----------------- Sturtevant | 8 |4 |5-1/2 | 552.9 | 140| 2000| 580| ... 5 | | | | | | | | -----------+------+------+------+-------+----+------+----+----------------- Sturtevant | 8 |4 |5-1/2 | ... | 140| 2000| 514|13.75 gals/hour 5-A | | | | | | | | -----------+------+------+------+-------+----+------+----+----------------- Thomas 8 | 8 |4 |5-1/2 | 552.9 | 135| 2000| 630| ... | | | | | | |lbs. with self-starter -----------+------+------+------+-------+----+------+----+----------------- Thomas 88 | 8 |4-1/8 |5-1/2 | 552.9 | 150| 2100| 525| ... | | | | | | |lbs. with self-starter -----------+------+------+------+-------+----+------+----+----------------- Wisconsin | 6 |5 |6-1/2 | 765.7 | 140| 1380| 637| ... -----------+------+------+------+-------+----+------+----+----------------- Wisconsin | 12 |5 |6-1/2 |1531.4 | 250| 1200| ...| ... -----------+------+------+------+-------+----+------+----+----------------- The carburetor used on this 150 horse-power Mercedes motor is precisely of the same type used on the Twin Six motor. It has two venturi throats, in the center of which is placed the gasoline spray nozzle of conventional type, fixed size orifices, immediately above which are placed two panel type throttles with side outlets. An idling or primary nozzle is arranged to discharge above the top of the venturi throat. The carburetor body is of cast aluminum and is water jacketed. It is bolted directly to air passage passing through the top and bottom half of the crank-case which passes down through the oil reservoir. The air before reaching the carburetor proper to some extent has cooled the oil in the crank chamber and has itself been heated to assist in the vaporization. The inlet pipes themselves are copper. All the passages between the venturi throat and the inlet valve have been carefully finished and polished. The only abnormal thing in the design of this motor is the short connecting rod which is considerably less than twice the stroke and would be considered very bad practice in motor car engines. A short connecting rod, however, possesses two very real virtues in that it cuts down height of the motor and the piston passes over the bottom dead center much more slowly than with a long rod. [Illustration: Fig. 245.--Part Sectional View of 90 Horse-Power Mercedes Engine, Which is Typical of the Design of Larger Sizes.] Other features of the design are a very stiff crank-case, both halves of which are bolted together by means of long through bolts, the crank-shaft main bearings are seated in the lower half of the case instead of in the usual caps and no provision is made for taking up the main bearings. The Mercedes company uses a plunger type of pump having mechanically operated piston valves and it is driven by means of worm gearing. The overhead cam-shaft construction is extremely light. The cam-shaft is mounted in a nearly cylindrical cast bronze case and is driven by means of bevel gears from the crank-shaft. The vertical bevel gear shaft through which the drive is taken from the crank-shaft to the cam-shaft operates at one and one-half times the crank-shaft speeds and the reduction to the half-time cam-shaft is secured through a pair of bevels. On this vertical shaft there is mounted the water pump and a bevel gear for driving two magnetos. The water pump mounted on this shaft tends to steady the drive and avoid vibration in the gearing. The cylinder sizes of six-cylinder aviation motors which have been built by Mercedes are Bore Stroke Horse-power 105 mm. 140 mm. 100 120 mm. 140 mm. 135 140 mm. 150 mm. 150 140 mm. 160 mm. 160 The largest of these motors has recently had its horse-power increased to 176 at 1450 R. P. M. This general design of motor has been the foundation for a great many other aviation motor designs, some of which have proved very successful but none of which is equal to the original. Among the motors which follow more or less closely the scheme of design and arrangement are the Hall-Scott, the Wisconsin motor, the Renault water-cooled, the Packard, the Christofferson and the Rolls-Royce. Each of these motors show considerable variation in detail. The Rolls-Royce and Renault are the only ones who have used the steel cylinder with the steel jacket. The Wisconsin motor uses an aluminum cylinder with a hardened steel liner and cast-iron valve seats. The Christofferson has somewhat similar design to the Wisconsin with the exception that the valve seats are threaded into the aluminum jacket and the cylinder head has a blank end which is secured to the aluminum casting by means of the valve seat pieces. The Rolls-Royce motors show small differences in details of design in cylinder head and cam-shaft housing from the Mercedes on which it has taken out patents, not only abroad but in this country. THE BENZ MOTOR In the Kaiser prize contest for aviation motors a four-cylinder Benz motor of 130 by 180 mm. won first prize, developing 103 B. H. P. at 1290 R. P. M. The fuel consumption was 210 grams per horse-power hour. Total weight of the motor was 153 kilograms. The oil consumption was .02 of a kilogram per horse-power hour. This motor was afterward expanded into a six-cylinder design and three different sizes were built. The accompanying table gives some of the details of weight, horse-power, etc. Motor type B FD FF Rated horse-power 85 100 150 Horse-power at 1250 r.p.m 88 108 150 Horse-power at 1350 r.p.m 95 115 160 Bore in millimeters 106 116 130 Stroke in millimeters 150 160 180 Offset of the cylinders in millimeters 18 20 20 Rate of gasoline consumption in grams 240 230 225 Oil consumption in grams per b.h.p. hour 10 10 10 Oil capacity in kilograms 36 4 4-1/2 Water capacity in litres 5-1/2 7-1/2 9-1/2 The weight with water and oil but with two magnetos, fuel feeder and air pump in kilograms 170 200 245 The weight of motors, including the water pump, two magnetos, double ignition, etc. 160 190 230 The weight of the exhaust pipe, complete in kilograms 4 4.8 5-1/2 The weight of the propeller hub in kilograms. 3-1/2 4 4 The Benz cylinder is a simple, straightforward design and a very reliable construction and not particularly difficult to manufacture. The cylinder is cast of iron without a water jacket but including 45 degrees angle elbows to the valve ports. The cylinders are machined wherever possible and at other points have been hand filed and scraped, after which a jacket, which is pressed in two halves, is gas welded by means of short pipes welded on to the jacket. The bottom and the top of the cylinders become water galleries, and by this means separate water pipes with their attendant weight and complication are eliminated. Rubber rings held in aluminum clamps serve to connect the cylinders together. The whole construction turns out very neat and light. The cylinder walls are 4 mm. or 3/16" thick and the combustion chamber is of cylindrical pancake form and is 140 mm. or 5.60 inch in diameter. The valve seats are 68 mm. in diameter and the valve port is 62 mm. in diameter. The passage joining the port is 57 mm. in diameter. In order to insert the valves into the cylinder the valve stem is made with two diameters and the valve has to be cocked to insert it in the guide, which has a bronze bushing at its upper end to compensate for the smaller valve stem diameter. The valve stem is 14 mm. or 9/16" in diameter and is reduced at its upper portion to 9-1/2 mm. The valves are operated through a push rod and rocker arm construction, which is 7/16" and exceedingly light. Rocker arm supports are steel studs with enlarged heads to take a double row ball bearing. A roller is mounted at one end of the rocker arm to impinge on the end of the valve stem, and the rocker arm has an adjustable globe stud at the other end. The push rods are light steel tubes with a wall thickness of 0.75 mm. and have a hardened steel cup at their upper end to engage the rocker arm globe stud and a hardened steel globe at their lower end to socket in the roller plunger. The Benz cam-shaft has a diameter of 26 mm. and is bored straight through 18 mm. and there is a spiral gear made integrally with the shaft in about the center of its length for driving the oil pump gear. The cam faces are 10 mm. wide. There is also, in addition to the intake and exhaust cams, a set of half compression cams. The shaft is moved longitudinally in its bearings by means of an eccentric to put these cams into action. At the fore end of the shaft is a driving gear flange which is very small in diameter and very thin. The flange is 68 mm. in diameter and 4 mm. thick and is tapped to take 6 mm. bolts. The total length of cam-shaft is 1038 mm., and it becomes a regular gun boring job to drill a hole of this length. The cam-shaft gear is 140 mm. or 5-1/2 inches outside diameter. It has fifty-four teeth and the gear face is 15 mm. or 19/32". The flange and web have an average thickness of 4 mm. or 5/32" and the web is drilled full of holes interposed between the spur gear mounted on the cam-shaft and the cam-shaft gear. There is a gear which serves to drive the magnetos and tachometer, also the air pump. The shaft is made integrally with this gear and has an eccentric portion against which the air pump roll plunger impinges. The seven-bearing crank-shaft is finished all over in a beautiful manner, and the shaft out of the particular motor we have shows no signs of wear whatever. The crank-pins are 55 mm. in diameter and 69 mm. long. Through both the crank-pin and main bearings there is drilled a 28 mm. hole, and the crank cheeks are plugged with solder. The crank cheeks are also built to convey the lubricant to the crank-pins. At the fore end of the crank cheek there is pressed on a spur driving gear. There is screwed on to the front end of the shaft a piece which forms a bevel water pump driving gear and the starting dog. At the rear end of the shaft very close to the propeller hub mounting there is a double thrust bearing to take the propeller thrust. Long, shouldered studs are screwed into the top half of the crank-case portion of the case and pass clean through the bottom half of the case. The case is very stiff and well ribbed. The three center bearing diaphragms have double walls. The center one serves as a duct through which water pipe passes, and those on either side of the center form the carburetor intake air passages and are enlarged in section at one side to take the carburetor barrel throttle. The pistons are of cast iron and carry three concentric rings 1/4 inch wide on their upper end, which are pinned at the joint. The top of the piston forms the frustum of the cone and the pistons are 110 mm. in length. The lower portion of the skirt is machined inside and has a wall thickness of 1 mm. Riveted to the piston head is a conical diaphragm which contacts with the piston pin when in place and serves to carry the heat off the center of the piston. The oil pump assembly comprises a pair of plunger pumps which draw oil from a separate outside pump, and constructed integrally with it is a gear pump which delivers the oil under about 60 pound pressure through a set of copper pipes in the base to the main bearings. The plunger oil pump shows great refinement of detail. A worm wheel and two eccentrics are machined up out of one piece and serve to operate the plungers. [Illustration: Fig. 246.--Part Sectional Side View and Sectional End View of Benz 160 Horse-Power Aviation Engine.] Some interesting details of the 160 horse-power Benz motor, which is shown at Fig. 246, are reproduced from the "Aerial Age Weekly," and show how carefully the design has been considered. Maximum horse-power, 167.5 B. H. P. Speed at maximum horse-power, 1,500 R. P. M. Piston speed at maximum horse-power, 1,770 ft. per minute. Normal horse-power, 160 B. H. P. Speed at normal horse-power, 1,400 R. P. M. Piston speed at normal horse-power, 1,656 ft. per minute. Brake mean pressure at maximum horse-power, 101.2 pound per square inch. Brake mean pressure at normal horse-power, 103.4 pound per square inch. Specific power cubic inch swept volume per B. H. P., 5.46 cubic inch; 160 B. H. P. Weight of piston, complete with gudgeon pin, rings, etc., 5.0 pound. Weight of connecting rod, complete with bearings, 4.99 pound; 1.8 pound reciprocating. Weight of reciprocating parts per cylinder, 6.8 pound. Weight of reciprocating parts per square inch of piston area, 0.33 pound. Outside diameter of inlet valve, 68 mm.; 2.68 inches. Diameter of inlet valve port (_d_), 61.5 mm.; 2.42 inches. Maximum lift of inlet valve (_h_), 11 mm.; 0.443 inch. Area of inlet valve opening ([pi] _d_ _h_), 21.25 square cm.; 3.29 square inches. Inlet valve opens, degrees on crank, top dead center. Inlet valve closes, degrees on crank, 60° late; 35 mm. late. Outside diameter of exhaust valve, 68 mm.; 2.68 inches. Diameter of exhaust valve port (_d_), 61.5 mm.; 2.42 inches. Maximum lift of exhaust valve (_h_) 11 mm.; 0.433 inch. Area of exhaust valve opening ([pi] _d_ _h_), 21.25 square cm.; 3.29 square inches. Exhaust valve opens, degrees on crank, 60° early; 35 mm. early. Exhaust valve closes, degrees on crank, 16-1/2° late; 5 mm. late. Length of connecting rod between centers, 314 mm.; 12.36 inches. Ratio connecting rod to crank throw, 3.49:1. Diameter of crank-shaft, 55 mm. outside, 2.165 inches; 28 mm. inside, 1.102 inches. Diameter of crank-pin, 55 mm. outside, 2.165 inches; 28 mm. inside, 1.102 inches. Diameter of gudgeon pin, 30 mm. outside, 1.181 inches; 19 mm. inside, 0.708 inch. Diameter of cam-shaft, 26 mm. outside, 1.023 inches; 18 mm. inside, 0.708 inch. Number of crank-shaft bearings, 7. Projected area of crank-pin bearings, 36.85 square cm.; 5.72 square inches. Projected area of gudgeon pin bearings, 22.20 square cm.; 3.44 square inches. Firing sequence, 1, 5, 3, 6, 2, 4. Type of magnetos, ZH6 Bosch. Direction of rotation of magneto from driving end, one clock, one anti-clock. Magneto timing, full advance, 30° early (16 mm. early). Type of carburetors (2) Benz design. Fuel consumption per hour, normal horse-power, 0.57 pint. Normal speed of propeller, engine speed, 1,400 R. P. M. AUSTRO-DAIMLER ENGINE One of the first very successful European flying engines which was developed in Europe is the Austro-Daimler, which is shown in end section in a preceding chapter. The first of these motors had four-cylinders, 120 by 140 millimeters, bore and stroke, with cast iron cylinders, overhead valves operated by means of a single rocker arm, controlled by two cams and the valves were closed by a single leaf spring which oscillates with the rocker arm. The cylinders are cast singly and have either copper or steel jackets applied to them. The four-cylinder design was afterwards expanded to the six-cylinder design and still later a six-cylinder motor of 130 by 175 millimeters was developed. This motor uses an offset crank-shaft, as does the Benz motor, and the effect of offset has been discussed earlier on in this treatise. The Benz motor also uses an offset cam-shaft which improves the valve operation and changes the valve lift diagram. The lubrication also is different than any other aviation motor, since individual high pressure metering pumps are used to deliver fresh oil only to the bearings and cylinders, as was the custom in automobile practice some ten years ago. SUNBEAM AVIATION ENGINES These very successful engines have been developed by Louis Coatalen. At the opening of the war the largest sized Coatalen motor was 225 horse-power and was of the L-head type having a single cam-shaft for operating valves and was an evolution from the twelve-cylinder racing car which the Sunbeam Company had previously built. Since 1914 the Sunbeam Company have produced engines of six-, eight-, twelve- and eighteen-cylinders from 150 to 500 horse-power with both iron and aluminum cylinders. For the last two years all the motors have had overhead cam-shafts with a separate shaft for operating the intake and exhaust valves. Cam-shafts are connected through to the crank-shaft by means of a train of spur gears, all of which are mounted on two double row ball bearings. In the twin six, 350 horse-power engine, operating at 2100 R. P. M., requires about 4 horse-power to operate the cam-shafts. This motor gives 362 horse-power at 2100 revolutions and has a fuel consumption of 51/100 of a pint per brake horse-power hour. The cylinders are 110 by 160 millimeters. The same design has been expanded into an eighteen-cylinder which gives 525 horse-power at 2100 turns. There has also been developed a very successful eight-cylinder motor rated at 2220 horse-power which has a bore and stroke of 120 by 130 millimeters, weight 450 pounds. This motor is an aluminum block construction with steel sleeves inserted. Three valves are operated, one for the inlet and two for the exhaust. One cam-shaft operates the three valves. [Illustration: Fig. 247.--At Top, the Sunbeam Overhead Valve 170 Horse-Power Six-Cylinder Engine. Below, Side View of Sunbeam 350 Horse-Power Twelve-Cylinder Vee Engine.] The modern Sunbeam engines operate with a mean effective pressure of 135 pounds with a compression ratio of 6 to 1 sea level. The connecting rods are of the articulated type as in the Renault motor and are very short. The weight of these motors turns out at 2.6 pounds per brake horse-power, and they are able to go through a 100 hour test without any trouble of any kind. The lubricating system comprises a dry base and oil pump for drawing the oil off from the base, whence it is delivered to the filter and cooling system. It then is pumped by a separate high pressure gear pump through the entire motor. In these larger European motors, castor-oil is used largely for lubrication. It is said that without the use of castor-oil it is impossible to hold full power for five hours. Coatalen favors aluminum cylinders rather than cast iron. The series of views in Figs. 247 to 250 inclusive, illustrates the vertical, narrow type of engine; the V-form; and the broad arrow type wherein three rows, each of six-cylinders, are set on a common crank-case. In this water-cooled series the gasoline and oil consumption are notably low, as is the weight per horse-power. [Illustration: Fig. 248.--Side View of Eighteen-Cylinder Sunbeam Coatalen Aircraft Engine Rated at 475 B.H.P.] [Illustration: Fig. 249.--Sunbeam Eighteen-Cylinder Motor, Viewed from Pump and Magneto End.] In the eighteen-cylinder overhead valve Sunbeam-Coatalen aircraft engine of 475 brake horse-power, there are no fewer than half a dozen magnetos. Each magneto is inclosed. Two sparks are furnished to each cylinder from independent magnetos. On this engine there are also no fewer than six carburetors. Shortness of crank-shaft, and therefore of engine length, and absence of vibration are achieved by the linking of the connecting-rods. Those concerned with three-cylinders in the broad arrow formation work on one crank-pin, the outer rods being linked to the central master one. In consequence of this arrangement, the piston travel in the case of the central row of cylinders is 160 mm., while the stroke of the pistons of the cylinders set on either side is in each case 168 mm. Inasmuch as each set of six-cylinders is completely balanced in itself, this difference in stroke does not affect the balance of the engine as a whole. The duplicate ignition scheme also applies to the twelve-cylinder 350 brake horse-power Sunbeam-Coatalen overhead valve aircraft engine type. It is distinguishable, incidentally, by the passage formed through the center of each induction pipe for the sparking plug in the center cylinder of each block of three. In this, as in the eighteen-cylinder and the six-cylinder types, there are two cam-shafts for each set of cylinders. These cam-shafts are lubricated by low pressure and are operated through a train of inclosed spur wheels at the magneto end of the machine. The six-cylinder, 170 brake horse-power vertical type employs the same general principles, including the detail that each carburetor serves gas to a group of three-cylinders only. It will be observed that this engine presents notably little head resistance, being suitable for multi-engined aircraft. [Illustration: Fig. 250.--Propeller End of Sunbeam Eighteen-Cylinder 475 B.H.P. Aviation Engine.] INDICATING METERS FOR AUXILIARY SYSTEMS [Illustration: Fig. 251.--View of Airplane Cowl Board, Showing the Various Navigating and Indicating Instruments to Aid the Aviator in Flight.] The proper functioning of the power plant and the various groups comprising it may be readily ascertained at any time by the pilot because various indicating meters and pressure gauges are provided which are located on a dash or cowl board in front of the aviator, as shown at Fig. 251. The speed indicator corresponds to the speedometer of an automobile and gives an indication of the speed the airplane is making, which taken in conjunction with the clock will make it possible to determine the distance covered at a flight. The altimeter, which is an aneroid barometer, outlines with fair accuracy the height above the ground at which a plane is flying. These instruments are furnished to enable the aviator to navigate the airplane when in the air, and if the machine is to be used for cross-country flying, they may be supplemented by a compass and a drift set. It will be evident that these are purely navigating instruments and only indicate the motor condition in an indirect manner. The best way of keeping track of the motor action is to watch the tachometer or revolution counter which is driven from the engine by a flexible shaft. This indicates directly the number of revolutions the engine is making per minute and, of course, any slowing up of the engine in normal flights indicates that something is not functioning as it should. The tachometer operates on the same principle as the speed indicating device or speedometer used in automobiles except that the dial is calibrated to show revolutions per minute instead of miles per hour. At the extreme right of the dash at Fig. 251 the spark advance and throttle control levers are placed. These, of course, regulate the motor speed just as they do in an automobile. Next to the engine speed regulating levers is placed a push button cut-out switch to cut out the ignition and stop the motor. Three pressure gauges are placed in a line. The one at the extreme right indicates the pressure of air on the fuel when a pressure feed system is used. The middle one shows oil pressure, while that nearest the center of the dash board is employed to show the air pressure available in the air starting system. It will be evident that the character of the indicating instruments will vary with the design of the airplane. If it was provided with an electrical starter instead of an air system electrical indicating instruments would have to be provided. COMPRESSED AIR-STARTING SYSTEMS Two forms of air-starting systems are in general use, one in which the crank-shaft is turned by means of an air motor, the other class where compressed air is admitted to the cylinders proper and the motor turned over because of the air pressure acting on the engine pistons. A system known as the "Never-Miss" utilizes a small double-cylinder air pump is driven from the engine by means of suitable gearing and supplies air to a substantial container located at some convenient point in the fuselage. The air is piped from the container to a dash-control valve and from this member to a peculiar form of air motor mounted near the crank-shaft. The air motor consists of a piston to which a rack is fastened which engages a gear mounted on the crank shaft provided with some form of ratchet clutch to permit it to revolve only in one direction, and then only when the gear is turning faster than the engine crank-shaft. The method of operation is extremely simple, the dash-control valve admitting air from the supply tank to the top of the pump cylinder. When in the position shown in cut the air pressure will force the piston and rack down and set the engine in motion. A variety of air motors are used and in some the pump and motor may be the same device, means being provided to change the pump to an air motor when the engine is to be turned over. The "Christensen" air starting system is shown at Figs. 252 and 253. An air pump is driven by the engine, and this supplies air to an air reservoir or container attached to the fuselage. This container communicates with the top of an air distributor when a suitable control valve is open. An air pressure gauge is provided to enable one to ascertain the air pressure available. The top of each cylinder is provided with a check valve, through which air can flow only in one direction, i.e., from the tank to the interior of the cylinder. Under explosive pressure these check valves close. The function of the distributor is practically the same as that of an ignition timer, its purpose being to distribute the air to the cylinders of the engine only in the proper firing order. All the while that the engine is running and the car is in motion the air pump is functioning, unless thrown out of action by an easily manipulated automatic control. When it is desired to start the engine a starting valve is opened which permits the air to flow to the top of the distributor, and then through a pipe to the check valve on top of the cylinder about to explode. As the air is going through under considerable pressure it will move the piston down just as the explosion would, and start the engine rotating. The inside of the distributor rotates and directs a charge of air to the cylinder next to fire. In this way the engine is given a number of revolutions, and finally a charge of gas will be ignited and the engine start off on its cycle of operation. To make starting positive and easier some gasoline is injected in with the air so an inflammable mixture is present in the cylinders instead of air only. This ignites easily and the engine starts off sooner than would otherwise be the case. The air pressure required varies from 125 to 250 pounds per square inch, depending upon the size and type of the engine to be set in motion. [Illustration: Fig. 252.--Parts of Christensen Air Starting System Shown at A, and Application of Piping and Check Valves to Cylinders of Thomas-Morse Aeromotor Outlined at B.] [Illustration: Fig. 253.--Diagrams Showing Installation of Air Starting System on Thomas-Morse Aviation Motor.] ELECTRIC STARTING SYSTEMS Starters utilizing electric motors to turn over the engine have been recently developed, and when properly made and maintained in an efficient condition they answer all the requirements of an ideal starting device. The capacity is very high, as the motor may draw current from a storage battery and keep the engine turning over for considerable time on a charge. The objection against their use is that it requires considerable complicated and costly apparatus which is difficult to understand and which requires the services of an expert electrician to repair should it get out of order, though if battery ignition is used the generator takes the place of the usual ignition magneto. In the Delco system the electric current is generated by a combined motor-generator permanently geared to the engine. When the motor is running it turns the armature and the motor generator is acting as a dynamo, only supplying current to a storage battery. On account of the varying speeds of the generator, which are due to the fluctuation in engine speed, some form of automatic switch which will disconnect the generator from the battery at such times that the motor speed is not sufficiently high to generate a current stronger than that delivered by the battery is needed. These automatic switches are the only delicate part of the entire apparatus, and while they require very delicate adjustment they seem to perform very satisfactorily in practice. When it is desired to start the engine an electrical connection is established between the storage battery and the motor-generator unit, and this acts as a motor and turns the engine over by suitable gearing which engages the gear teeth cut into a special gear or disc attached to the engine crank-shaft. When the motor-generator furnishes current for ignition as well as for starting the motor, the fact that the current can be used for this work as well as starting justifies to a certain extent the rather complicated mechanism which forms a complete starting and ignition system, and which may also be used for lighting if necessary in night flying. An electric generator and motor do not complete a self-starting system, because some reservoir or container for electric current must be provided. The current from the generator is usually stored in a storage battery from which it can be made to return to the motor or to the same armature that produced it. The fundamental units of a self-starting system, therefore, are a generator to produce the electricity, a storage battery to serve as a reservoir, and an electric motor to rotate the motor crank-shaft. Generators are usually driven by enclosed gearing, though silent chains are used where the center distance between the motor shaft and generator shaft is too great for the gears. An electric starter may be directly connected to the gasoline engine, as is the case where the combined motor-generator replaces the fly-wheel in an automobile engine. The motor may also drive the engine by means of a silent chain or by direct gear reduction. Every electric starter must use a switch of some kind for starting purposes and most systems include an output regulator and a reverse current cut-out. The output regulator is a simple device that regulates the strength of the generator current that is supplied the storage battery. A reverse current cut-out is a form of check valve that prevents the storage battery from discharging through the generator. Brief mention is made of electric starting because such systems will undoubtedly be incorporated in some future airplane designs. Battery ignition is already being experimented with. BATTERY IGNITION SYSTEM PARTS A battery ignition system in its simplest form consists of a current producer, usually a set of dry cells or a storage battery, an induction coil to transform the low tension current to one having sufficient strength to jump the air gap at the spark-plug, an igniter member placed in the combustion chamber and a timer or mechanical switch operated by the engine so that the circuit will be closed only when it is desired to have a spark take place in the cylinders. Battery ignition systems may be of two forms, those in which the battery current is stepped up or intensified to enable it to jump an air gap between the points of the spark plug, these being called "high tension" systems and the low tension form (never used on airplane motors) in which the battery current is not intensified to a great degree and a spark produced in the cylinder by the action of a mechanical circuit breaker in the combustion chamber. The low tension system is the simplest electrically but the more complex mechanically. The high tension system has the fewest moving parts but numerous electrical devices. At the present time all airplane engines use high tension ignition systems, the magneto being the most popular at the present time. The current distribution and timing devices used with modern battery systems are practically the same as similar parts of a magneto. INDEX PAGE A Action of Four-cycle Engine 38 Action of Le Rhone Rotary Engine 503 Action of Two-cycle Engine 41 Action of Vacuum Feed System 119 Actual Duration of Different Functions 93 Actual Heat Efficiency 62 Adiabatic Diagram 51 Adiabatic Law 50 Adjustment of Bearings 449 Adjustment of Carburetors 151 Aerial Motors, Must be Light 20 Aerial Motors, Operating Conditions of 19 Aerial Motors, Requirements of 19 Aeromarine Six-cylinder Engine 527 Aeronautics, Division in Branches 18 Aerostatics 18 Air-cooled Engine Design 229 Air-cooling Advantages 231 Air-cooling, Direct Method 228 Air-cooling Disadvantages 231 Air-cooling Systems 223 Aircraft, Heavier Than Air 17 Aircraft, Lighter Than Air 18 Aircraft Types, Brief Consideration of 17 Air Needed to Burn Gasoline 113 Airplane Engine, Power Needed 21 Airplane Engines, Overhauling 412 Airplane Engine, How to Time 269 Airplane Engine Lubrication 209 Airplane, How Supported 21 Airplane Motors, German 543 Airplane Motor Types 20 Airplane Motors, Weight of 21 Airplane Power Plant Installation 324 Airplane Types 18 Airplanes, Horse-power Used in 26 Air Pressure Diminution, With Altitude 144 Altitude, How it Affects Mixture 153 Aluminum, Use in Pistons 297 American Aviation Engines, Statistics 546 Anzani Radial Engine Installation 344 Anzani Six-cylinder Star Engine 465 Anzani Six-cylinder Water-cooled Engine 459 Anzani Ten- and Twenty-cylinder Engines 468 Anzani Three-cylinder Engine 459 Anzani Three-cylinder Y Type 462 Argus Engine Construction 545 Armature Windings 168 Atmospheric Conditions, Compensating For 143 Austro-Daimler Engine 557 Aviatics 18 Aviation Engine, Aeromarine 527 Aviation Engine, Anzani Six-cylinder Star 465 Aviation Engine, Canton and Unné 469 Aviation Engine Cooling 219 Aviation Engine, Curtiss 519 Aviation Engine Cylinders 233 Aviation Engine, Early Gnome 472 Aviation Engine, German Gnome Type 495 Aviation Engine, Gnome Monosoupape 486 Aviation Engine, How To Dismantle 415 Aviation Engine, How to Start 460 Aviation Engine, Le Rhone Rotary 495 Aviation Engine Oiling 218 Aviation Engine Parts, Functions of 82 Aviation Engine, Renault Air-cooled 507 Aviation Engine, Stand for Supporting 414 Aviation Engine, Sturtevant 515 Aviation Engine, Thomas-Morse 521 Aviation Engine Types 457 Aviation Engine, Wisconsin 531 Aviation Engines, Anzani Six-cylinder Water-cooled 459 Aviation Engines, Anzani Ten- and Twenty-cylinder 468 Aviation Engines, Anzani Three-cylinder 459 Aviation Engines, Anzani Y Type 462 Aviation Engines, Argus 545 Aviation Engines, Austro-Daimler 557 Aviation Engines, Benz 551 Aviation Engines, Four- and Six-cylinder 88 Aviation Engines, German 543 Aviation Engines, Hall-Scott 539 Aviation Engines, Hispano-Suiza 512 Aviation Engines, Mercedes 543 Aviation Engines, Overhauling 412 Aviation Engines, Principal Parts of 80 Aviation Engines, Starting Systems For 567 Aviation Engines, Sunbeam 558 B Balanced Crank-shafts 318 Ball-bearing Crank-shafts 319 Battery Ignition Systems 571 Baverey Compound Nozzle 137 Bearings, Adjustment of 449 Bearing Alignment 453 Bearing Brasses, Fitting 450 Bearing Parallelism, Testing 453 Bearing Scrapers and Their Use 446 Benz Aviation Engines 551 Benz Engine Statistics 551 Berling Magneto 174 Berling Magneto, Adjustment of 180 Berling Magneto Care 180 Berling Magneto Circuits 176 Berling Magneto, Setting 178 Block Castings 234 Blowing Back 269 Bolts, Screwing Down 452 Bore and Stroke Ratio 240 Boyle's Law 49 Brayton Engine 48 Breaker Box, Adjustment of 180 Breast and Hand Drills 387 Burning Out Carbon Deposits 421 Bushings, Cam-shaft, Wear in 456 C Calipers, Inside and Outside 398 Cam Followers, Types of 260 Cams for Valve Actuation 259 Cam-shaft Bushings 456 Cam-shaft Design 313 Cam-shaft Drive Methods 261 Cam-shaft Testing 451 Cam-shafts and Timing Gears 456 Canton and Unné Engine 469 Carbon, Burning out with Oxygen 421 Carbon Deposits, Cause of 418 Carbon Removal 419 Carbon Scrapers, How Used 420 Carburetion Principles 112 Carburetion System Troubles 355 Carburetor, Claudel 127 Carburetor, Compound Nozzle Zenith 135 Carburetor, Concentric Float and Jet Type 125 Carburetor, Duplex Zenith 138 Carburetor, Duplex Zenith, Trouble in 357 Carburetor Installation, In Airplanes 148 Carburetor, Le Rhone 501 Carburetor, Master Multiple Jet 133 Carburetor, Schebler 125 Carburetor Troubles, How to Locate 354 Carburetor, Two Stage 131 Carburetor, What it Should Do 114 Carburetors, Float Feed 122 Carburetors, Multiple Nozzle 130 Carburetors, Notes on Adjustment 151 Carburetors, Reversing Position of 149 Carburetors, Spraying 120 Care of Dixie Magneto 188 Castor Oil, for Cylinder Lubrication 205 Castor Oil, Why Used In Gnome Engines 211 Center Gauge 403 Chisels, Forms of 384 Christensen Air Starting System 567 Circuits, Magnetic 161 Classification of Engines 458 Claudel Carburetor 127 Cleaning Distributor 180 Clearances Between Valve Stem and Actuators 261 Combustion Chamber Design 239 Combustion Chambers, Spherical 76 Common Tools, Outfit of 378 Comparing Two-cycle and Four-cycle Types 44 Compound Cam Followers 260 Compound Piston Rings 301 Compressed Air Starting System 565 Compression, Factors Limiting 69 Compression, in Explosive Motors, Value of 68 Compression Pressures, Chart for 72 Compression Temperature 71 Computations for Horse-power Needed 25 Computations for Temperature 52 Concentric Piston Ring 299 Concentric Valves 255 Connecting Rod Alignment, Testing 454 Connecting Rod, Conventional 308 Connecting Rod Forms 305 Connecting Rod, Gnome Engine 305 Connecting Rods, Fitting 449 Connecting Rods for Vee Engines 310 Connecting Rods, Le Rhone 498 Connecting Rods, Master 310 Constant Level Splash System 215 Construction of Dixie Magneto 186 Construction of Pistons 288 Conversion of Heat to Power 58 Cooling by Air 223 Cooling by Positive Water Circulation 224 Cooling, Heat Loss in 66 Cooling System Defects 358 Cooling Systems Used 223 Cooling Systems, Why Needed 219 Cotter Pin Pliers 384 Crank-case, Conventional 320 Crank-case Forms 320 Crank-case, Gnome 323 Crank-shaft, Built Up 315 Crank-shaft Construction 315 Crank-shaft Design 315 Crank-shaft Equalizer 449 Crank-shaft Form 315 Crank-shaft, Gnome Engine 483 Crank-shafts, Balanced 318 Crank-shafts, Ball Bearing 319 Cross Level 403 Crude Petroleum, Distillates of 111 Curtiss Aviation Engines 519 Curtiss Engine Installation 328 Curtiss Engine Repairing Tools 408 Cutting Oil Grooves 448 Cylinder Blocks, Advantages of 237 Cylinder Block, Duesenberg 235 Cylinder Castings, Individual 234 Cylinder Construction 233 Cylinder Faults and Correction 416 Cylinder Form and Crank-shaft Design 238 Cylinder Head Packings 417 Cylinder Head, Removable 239 Cylinder, I Head Form 248 Cylinder, L Head Form 248 Cylinder Oils 206 Cylinder Placing 20 Cylinder Placing in V Motor 99 Cylinder Retention, Gnome 475 Cylinder, T Head Form 248 Cylinders, Cast in Blocks 235 Cylinders, Odd Number in Rotary Engines 482 Cylinders, Repairing Scored 423 Cylinders, Valve Location in 245 D Defects in Cylinders 417 Defects in Dry Battery 373 Defects in Fuel System 354 Defects in Induction Coil 373 Defects in Magneto 372 Defects in Storage Battery 372 Defects in Timer 373 Defects in Wiring and Remedies 373 Die Holder 394 Dies for Thread Cutting 395 Diesel Motor Cards 67 Diesel System 144 Direct Air Cooling 228 Dirigible Balloons 18 Dismantling Airplane Engine 415 Distillates of Crude Petroleum 111 Division of Circle in Degrees 268 Dixie Ignition Magneto 184 Dixie Magneto, Care of 188 Draining Oil From Crank-case 214 Drilling Machines 386 Drills, Types and Use 388 Driving Cam-shaft, Methods of 262 Dry Cell Battery, Defects in 373 Duesenberg Sixteen Valve Engine 525 Duesenberg Valve Action 255 Duplex Zenith Carburetor 138 E Early Gnome Motor, Construction of 472 Early Ignition Systems 155 Early Types of Gas Engine 28 Early Vaporizer Forms 120 Eccentric Piston Ring 299 Economy, Factors Governing 64 Efficiency, Actual Heat 62 Efficiency, Maximum Theoretical 61 Efficiency, Mechanical 62 Efficiency of Internal Combustion Engine 60 Efficiency, Various Measures of 61 Eight-cylinder Engine 95 Eight-cylinder Timing Diagram 276 Electricity and Magnetism, Relation of 162 Electrical Ignition Best 156 Electric Starting Systems 569 Engine, Advantages of V Type 95 Engine Base Construction 319 Engine Bearings, Adjusting 443 Engine Bearings, Refitting 442 Engine Bed Timbers, Standard 330 Engine, Four-cycle, Action of 38 Engine, Four-cycle, Piston Movements in 40 Engine Functions, Duration of 93 Engine Ignition, Locating Troubles 353 Engine Installation, Gnome 344 Engine Installation, Anzani Radial 344 Engine Installation, Hall-Scott 332 Engine Installation, Rotary 342 Engine Operation, Sequence of 84 Engine Parts and Functions 80 Engine Starts Hard, Ignition Troubles Causing 369 Engine Stoppage, Causes of 347 Engine Temperatures 221 Engine Trouble Charts 369 Engine Troubles, Cooling 358 Engine Troubles, Hints For Locating 345 Engine Troubles, Ignition 353 Engine Troubles, Noisy Operation 359 Engine Troubles, Oiling 357 Engine Troubles Summarized 350 Engine, Two-cycle, Action of 41 Engines, Classification of 458 Engines, Cylinder Arrangement 31-32 Engines, Eight-cylinder V 95 Engines, Four-cylinder Forms 88 Engines, Graphic Comparison of 33-34-35 Engines, Internal Combustion, Types of 30 Engines, Multiple Cylinder, Power Delivery in 91 Engines, Multiple Cylinder, Why Best 83 Engines, Rotary Cylinder 107 Engines, Six-cylinder Forms 88 Engines, Twelve-cylinder 96 Equalizer, Crank-shaft 449 Exhaust Closing 270 Exhaust Valve Design, Early Gnome 475 Exhaust Valve Opening 270 Explosive Gases, Mixtures of 56 Explosive Motors, Inefficiency in 74 Explosive Motors, Why Best 27 F Factors Governing Economy 64 Factors Limiting Compression 70 Faults in Ignition 352 Figuring Horse-power Needed 21 Files, Use and Care of 383 First Law of Gases 49 Fitting Bearings By Scraping 447 Fitting Brasses 450 Fitting Connecting Rods 449 Fitting Main Bearings 448 Fitting Piston Rings 439 Float Feed Carburetor Development 124 Float Feed Carburetors 122 Force Feed Oiling System 218 Forked Connecting Rods 310 Four-cycle Engine, Action of 38 Four-cycle Engine, Why Best 45 Fourteen-cylinder Engine 474 Four Valves Per Cylinder 284 Friction, Definition of 302 Fuel Feed By Gravity 116 Fuel Feed by Vacuum Tank 117 Fuel Storage and Supply 116 Fuel Strainers, Types of 141 Fuel Strainers, Utility of 140 Fuel System Faults 354 Fuel System Installation, Hall-Scott 336 Fuel System, Gnome 490 Fuel Utilization Chart 62 G Gas Engine, Beau de Rocha's Principles 59 Gas Engine Development 28 Gas Engine, Early Forms of 48 Gas Engine, Inventors of 29 Gas Engine, Theory of 47 Gases, Compression of 49 Gases, First Law of 49 Gases, Second Law of 50 Gaskets, How to Use 452 Gasoline, Air Needed to Burn 113 Gas Engines, Parts of 80 Gas Vacuum Engine, Brown's 28 German Airplane Motors 543 German Gnome Type Engine 495 Gnome Aviation Engine, Early Form 472 Gnome Crank-shaft 483 Gnome Cylinder, Machining 489 Gnome Cylinder Retention 475 Gnome Engine, Fuel, Lubrication and Ignition 490 Gnome Engine, German Type 495 Gnome Engine Installation 344 Gnome Firing Order 482 Gnome Fourteen-cylinder, Engine 474 Gnome Fourteen-cylinder Engine Details 480 Gnome Monosoupape, How to Time 278 Gnome Monosoupape Type Engine 486 Graphic Comparison of Engine Types 33-34-35 Graphic Comparison, Two- and Four-cycle 46 Gravity Feed System 116 Grinding Valves 429 H Hall-Scott Aviation Engines 539 Hall-Scott Engine Installation 332 Hall-Scott Engine, Preparations For Starting 341 Hall-Scott Engine Tools 410 Hall-Scott Lubrication System 211 Hall-Scott Statistic Sheet 544 Heat and Its Work 54 Heat in Gas Engine Cylinder 69 Heat Given to Cooling Water 78 Heat Loss, Causes of 74 Heat Loss in Airplane Engine 221 Heat Loss in Wall Cooling 65 High Altitude, How it Affects Power 144 High Tension Magneto 172 Hints For Locating Engine Troubles 345 Hints for Starting Engine 361 Hispano-Suiza Model A Engine 512 Horse-power Needed in Airplane 21 Horse-power Needed, How Figured 22 How An Engine is Timed 277 I Ignition, Electric 156 Ignition, Elements of 157 Ignition of Gnome Engine 490 Ignition System, Battery 571 Ignition Systems, Early 155 Ignition System Faults 352 Ignition, Time of 273 Ignition, Two Spark 196 I Head Cylinders 248 Improvements in Gas Engines 29 Indicating Meters, Engine Speed 563 Indicating Meters, Oil and Air Pressure 563 Indicator Cards, How To Read 66 Indicator Cards, Value of 66 Individual Cylinder Castings 234 Induction Coil, Defects in 373 Inefficiency, Causes of 74 Inlet Valve Closing 272 Inlet Valve Opening 270 Installation, Airplane Engine 324 Installation, Curtiss OX-2 Engine 328 Installation, Hall-Scott Engine 332 Installation of Rotary Engines 342 Intake Manifold Construction 143 Intake Manifold Design 142 Internal Combustion Engine, Efficiency of 60, 62 Internal Combustion Engines, Main Types of 30 Inverted Engine Placing 325 Isothermal Diagram 51 Isothermal Law 48 K Keeping Oil Out of Combustion Chamber 303 Knight Sleeve Valves 266 L Lag and Lead, Explanation of 268 Lapping Crank-pins 445 Lead Given Exhaust Valve 270 Leak Proof Piston Rings 301 Lenoir Engine Action 48 Le Rhone Cams and Valve Actuation 500 Le Rhone Carburetor 501 Le Rhone Connecting Rod Assembly, Distinctive 498 Le Rhone Engine Action 503 Le Rhone Rotary Engine 495 L Head Cylinders 248 Liquid Fuels, Properties of 110 Locating Carburetor Troubles 354 Locating Engine Troubles 350 Locating Ignition Troubles 353 Locating Oiling Troubles 357 Location of Magneto Trouble 181 Losses in Wall Cooling 65 Lost Power and Overheating, Summary of Troubles Causing 363 Lubricants, Derivation of 204 Lubricants, Requirements of 204 Lubricating System Classification 208 Lubricating Systems, Selection of 208 Lubrication By Constant Level Splash System 215 Lubrication By Dry Crank-case Method 218 Lubrication By Force Feed Best 218 Lubrication of Magneto 180 Lubrication System, Gnome 490 Lubrication System, Hall-Scott 211 Lubrication System, Thomas-Morse 210 Lubrication, Theory of 202 Lubrication, Why Necessary 201 M Magnetic Circuits 161 Magnetic Influence Defined 158 Magnetic Lines of Force 161 Magnetic Substances 158 Magnetism, Flow Through Armature 166 Magnetism, Fundamentals of 157 Magnetism, Relation to Electricity 162 Magneto, Action of High Tension 173 Magneto Armature Windings 168 Magneto, Basic Principles of 163 Magneto, Berling 174 Magneto, Defects in 372 Magneto Distributor, Cleaning 180 Magneto Ignition Systems 169 Magneto Ignition Wiring 179 Magneto Interrupter, Adjustment of 180 Magneto, Low Voltage 168 Magneto, Lubrication of 180 Magneto Maintenance 180 Magneto, Method of Driving 175 Magneto Parts and Functions 167 Magneto, The Dixie 184 Magneto Timing 179 Magneto, Timing Dixie 188 Magneto, Transformer System 171 Magneto Trouble, Location of 181 Magneto, True High Tension 172 Magneto, Two Spark Dual 177 Magnets, Forms of 160 Magnets, How Produced 162 Magnets, Properties of 159 Main Bearings, Fitting 448 Manifold, Intake 143 Master Multiple Jet Carburetor 133 Master Rod Construction 310 Maximum Theoretical Efficiency 61 Meaning of Piston Speed 241 Measures of Efficiency 61 Measuring Tools 397 Mechanical Efficiency 62 Mercedes Aviation Engine 543 Metering Pin Carburetor, Stewart 128 Micrometer Caliper, Beading 405 Micrometer Calipers, Types and Use 404 Mixture, Effect of Altitude on 153 Mixture, Proportions of 151 Mixture, Starvation of 149 Monosoupape Gnome Engine 486 Mother Bod, Gnome Engine 305 Motor Misfires, Carburetor Faults Causing 374 Motor Misfires, Ignition Troubles Causing 370 Motor Races, Carburetor Faults Causing 374 Motor Starts Hard, Carburetor Faults Causing 374 Motor Stops In Flight, Carburetor Faults 374 Motor Stops Without Warning, Ignition Troubles 370 Multiple Cylinder Engine, Why Best 83 Multiple Nozzle Vaporizers 129 Multiple Valve Advantages 286 N Noisy Engine Operation, Causes of 359 Noisy Operation, Carburetor Faults Causing 374 Noisy Operation, Summary of Troubles Causing 365 O Offset Cylinders, Reason for 243 Oil Bi-pass, Function of 213 Oil, Draining From Crank-case 214 Oil Grooves, Cutting 448 Oil Pressure in Hall-Scott System 214 Oil Pressure Relief Bi-pass 213 Oiling System Defects 357 Oils for Cylinder Lubrication 206 Oils for Hall-Scott Engine 215 Oils for Lubrication 204 Operating Principles of Engines 37 Oscillating Piston Pin 295 Otto Four-cycle Cards 67 Overhauling Aviation Engines 412 Overhead Cam-shaft Location 252 Overheating, Causes of 359 P Panhard Concentric Valves 255 Petroleum, Distillates of 111 Piston, Differential 291 Piston Pin Retention 293 Piston Ring Construction 298 Piston Ring Joints 299 Piston Ring Manipulation 438 Piston Ring Troubles 437 Piston Rings, Compound 301 Piston Rings, Concentric 299 Piston Rings, Eccentric 299 Piston Rings, Fitting 439 Piston Rings, Leak Proof 301 Piston Rings, Replacing 441 Piston Speed in Airplane Engines 241 Piston Speed, Meaning of 241 Piston Troubles and Remedies 436 Pistons, Aluminum 296 Pistons, Details of 288 Pistons for Two-cycle Engines 289 Positive Valve Systems 283 Power, Affected by High Altitude 145 Power Delivery in Multiple Cylinder Engines 91 Power, How Obtained From Heat 58 Power Needed in Airplane Engines 21 Power Used in Airplanes 26 Precautions in Assembling Parts 452 Pressure Relief Fitting 213 Pressures and Temperatures 63 Principles of Carburetion 112 Principles of Magneto Action 163 Properties of Cylinder Oils 207 Properties of Liquid Fuels 110 Pump Circulation Systems 226 Pump Forms 226 R Radial Cylinder Arrangement 103 Reading Indicator Cards 67 Reamers, Types and Use 392 Reassembling Parts, Precautions in 451 Removable Cylinder Head 239 Renault Air Cooled Engine 507 Renault Engine Details 508 Repairing Scored Cylinders 423 Requisites for Best Power Effect 59 Reseating and Truing Valves 426 Resistance, Influence of 22 Rotary Cylinder Engines 107 Rotary Engine, Le Rhone 495 Rotary Engines, Castor Oil for 211 Rotary Engines, Installing 342 Rotary Engines, Why Odd Number of Cylinders 109 Rotary Engines, Why Odd Number of Cylinders Is Used 482 S S. A. E. Engine Bed Dimensions 330 Salmson Nine-cylinder Engine 470 Schebler Carburetor 125 Scissors Joint Rods 310 Scored Cylinders, Repairing 422 Scrapers, Types of Bearing 446 Scraping Bearings to Fit 447 Second Law of Gases 50 Sequence of Engine Operation 84 Six-cylinder Timing Diagram 275 Sixteen Valve Duesenberg Engine 525 Skipping or Irregular Operation, Causes of 367 Sliding Sleeve Valves 266 Spark Plug Air Gaps, Setting 197 Spark Plug, Design of 193 Spark Plug, Mica 194 Spark Plug, Porcelain 193 Spark Plugs, Defects in 371 Spark Plugs for Two Spark Ignition 197 Spark Plug, Special for Airplane Engine 199 Spark Plug, Standard S. A. E. 195 Spherical Combustion Chambers 76 Splash Lubrication 215 Split Pin Remover 384 Spraying Carburetors 120 Springless Valves 280 Springs, for Valves 263 Spring Winder 384 Sprung Cam-shaft, Testing 451 Stand for Supporting Engine 414 Starting Engine, Hints for 361 Starting Hall-Scott Engine 341 Starting System, Christensen 567 Starting Systems, Compressed Air 565 Starting Systems, Electric 569 Statistics, American Engines 546, 547 Statistic Sheet, Hall-Scott Engines 544 Statistics of Benz Engine 551 Steam Engine, Efficiency of 59 Steam Engine, Why Not Used 27 Steel Scale, Machinists' 399 Stewart Metering Pin Carburetor 128 Storage Battery, Defects in 372 Stroke and Bore Ratio 240 Sturtevant Model 5A Engine 515 Summary of Engine Types 30 Sunbeam Aviation Engines 588 Sunbeam Eighteen-Cylinder Engine 561 T Tap and Die Sets 397 Taps for Thread Cutting 394 Tee Head Cylinders 247 Temperature Computations 52 Temperatures and Explosive Pressures 64 Temperatures and Pressures 63 Temperatures, Operating 221 Testing Bearing Parallelism 453 Testing Connecting Rod Alignment 454 Testing Fit of Bearings 446 Testing Sprung Cam-shaft 451 Theory of Gas Engine 47 Theory of Lubrication 203 Thermo-syphon Cooling System 227 Thomas-Morse Aviation Engine 521 Thomas-Morse Lubrication System 210 Thread Pitch Gauge 403 Time of Ignition 273 Timer, Defects in 373 Times of Explosion 56 Timing Dixie Magneto 188 Timing Gears, Effects of Wear 456 Timing Magneto 179 Timing Valves 267 Tool Outfits, Typical 408 Tools for Adjusting and Erecting 378 Tools for Bearing Work 445 Tools for Curtiss Engines 408 Tools for Grinding Valves 430 Tools for Hall-Scott Engines 410, 411 Tools for Measuring 397 Tools for Reseating Valves 426 Trouble in Carburetion System 355 Trouble, Location of Magneto 181 Troubles, Engine, How to Locate 345 Troubles, Ignition 353 Troubles in Oiling System 357 True High Tension Magneto 172 Twelve-Cylinder Engines 96 Two-and Four-Cycle Types, Comparison of 44 Two-Cycle Engine Action 41 Two-Cycle Three-Port Engine 43 Two-Cycle Two-Port Engine 42 Two-Spark Ignition 196 Two-Stage Carburetor 131 Types of Aircraft 17 Types of Internal Combustion Engines 30 V Vacuum Fuel Feed, Stewart 119 Value of Compression 69 Value of Indicator Cards 66 Valve Actuation, Le Rhone 500 Valve Design and Construction 256 Valve-Grinding Processes 429 Valve-Lifting Cams 259 Valve-Lifting Plungers 260 Valve Location Practice 245 Valve Operating Means 252 Valve Operating System, Depreciation in 433 Valve Operation 258 Valve Removal and Inspection 424 Valve Seating, How to Test 432 Valve Springs 263 Valve Timing, Exhaust 270 Valve Timing, Gnome Monosoupape 278 Valve Timing, Intake 270 Valve Timing, Lag and Lead 269 Valve Timing Procedure 277 Valve Timing Practice 267 Valves, Electric Welded 258 Valves, Flat and Bevel Seat 257 Valves, Four per Cylinder 284 Valves, How Placed in Cylinder 247 Valves in Cages 249 Valves in Removable Heads 249 Valves, Materials Used for 258 Valves, Reseating 426 Vaporizer, Simple Forms of 120 V Engines, Cylinder Arrangement in 102 Vernier, How Used 401 W Wall Cooling, Losses in 65 Water Cooling by Natural Circulation 227 Water Cooling System 224 Weight of Airplane Motors 21 Wiring, Defects in 373 Wiring Magneto Ignition System 179 Wisconsin Engines 531 Wrenches, Forms of 380 Wrist-pin Retention 293 Wrist-pin Retention Locks 295 Wrist-pin Wear and Remedy 442 Z Zenith Carburetor, Action of 137 Zenith Duplex Carburetor, Troubles in 356 Zenith Carburetor Installation 139 LIST OF ILLUSTRATIONS Frontispiece. Part Sectional View of Hall-Scott Airplane Motor, Showing Principal Parts. Fig. 1. Diagrams Illustrating Computations for Horse-Power Required for Airplane Flight. Fig. 2. Plate Showing Heavy, Slow Speed Internal Combustion Engines Used Only for Stationary Power in Large Installations Giving Weight to Horse-Power Ratio. Fig. 3. Various Forms of Internal Combustion Engines Showing Decrease in Weight to Horse-Power Ratio with Augmenting Speed of Rotation. Fig. 4. Internal Combustion Engine Types of Extremely Fine Construction and Refined Design, Showing Great Power Outputs for Very Small Weight, a Feature Very Much Desired in Airplane Power Plants. Fig. 5. Outlining First Two Strokes of Piston in Four-Cycle Engine. Fig. 6. Outlining Second Two Strokes of Piston in Four-Cycle Engine. Fig. 7. Sectional View of L Head Gasoline Engine Cylinder Showing Piston Movements During Four-Stroke Cycle. Fig. 8. Showing Two-port, Two-cycle Engine Operation. Fig. 9. Defining Three-port, Two-cycle Engine Action. Fig. 10. Diagrams Contrasting Action of Two- and Four-Cycle Cylinders on Exhaust and Intake Stroke. Fig. 11. Diagram Isothermal and Adiabatic Lines. Fig. 12. Graphic Diagram Showing Approximate Utilization of Fuel Burned in Internal-Combustion Engine. Fig. 13. Otto Four-Cycle Card. Fig. 14. Diesel Motor Card. Fig. 15. Diagram of Heat in the Gas Engine Cylinder. Fig. 16. Chart Showing Relation Between Compression Volume and Pressure. Fig. 17. The Thompson Indicator, an Instrument for Determining Compressions and Explosion Pressure Values and Recording Them on Chart. Fig. 18. Spherical Combustion Chamber. Fig. 19. Enlarged Combustion Chamber. Fig. 20. Mercedes Aviation Engine Cylinder Section Showing Approximately Spherical Combustion Chamber and Concave Piston Top. Fig. 21. Side Sectional View of Typical Airplane Engine, Showing Parts and Their Relation to Each Other. This Engine is an Aeromarine Design and Utilizes a Distinctive Concentric Valve Construction. Fig. 22. Diagrams Illustrating Sequence of Cycles in One- and Two-Cylinder Engines Showing More Uniform Turning Effort on Crank-Shaft with Two-Cylinder Motors. Fig. 23. Diagrams Demonstrating Clearly Advantages which Obtain when Multiple-Cylinder Motors are Used as Power Plants. Fig. 24. Showing Three Possible Though Unconventional Arrangements of Four-Cylinder Engines. Fig. 25. Diagrams Outlining Advantages of Multiple Cylinder Motors, and Why They Deliver Power More Evenly Than Single Cylinder Types. Fig. 26. Diagrams Showing Duration of Events for a Four-Stroke Cycle, Six-Cylinder Engine. Fig. 27. Diagram Showing Actual Duration of Different Strokes in Degrees. Fig. 28. Another Diagram to Facilitate Understanding Sequence of Functions in Six-Cylinder Engine. Fig. 29. Types of Eight-Cylinder Engines Showing the Advantage of the V Method of Cylinder Placing. Fig. 30. Curves Showing Torque of Various Engine Types Demonstrate Graphically Marked Advantage of the Eight-Cylinder Type. Fig. 31. Diagrams Showing How Increasing Number of Cylinders Makes for More Uniform Power Application. Fig. 32. How the Angle Between the Cylinders of an Eight- and Twelve-Cylinder V Motor Varies. Fig. 33. The Hall-Scott Four-Cylinder 100 Horse-Power Aviation Motor. Fig. 34. Two Views of the Duesenberg Sixteen Valve Four-Cylinder Aviation Motor. Fig. 35. The Hall-Scott Six-Cylinder Aviation Engine. Fig. 36. The Curtiss Eight-Cylinder, 200 Horse-Power Aviation Engine. Fig. 37. The Sturtevant Eight-Cylinder, High Speed Aviation Motor. Fig. 38. Anzani 40-50 Horse-Power Five-Cylinder Air Cooled Engine. Fig. 39. Unconventional Six-Cylinder Aircraft Motor of Masson Design. Fig. 40. The Gnome Fourteen-Cylinder Revolving Motor. Fig. 41. How Gravity Feed Fuel Tank May Be Mounted Back of Engine and Secure Short Fuel Line. Fig. 42. The Stewart Vacuum Fuel Feed Tank. Fig. 43. Marine-Type Mixing Valve, by which Gasoline is Sprayed into Air Stream Through Small Opening in Air-Valve Seat. Fig. 44. Tracing Evolution of Modern Spray Carburetor. A--Early Form Evolved by Maybach. B.--Phoenix-Daimler Modification of Maybach's Principle. C--Modern Concentric Float Automatic Compensating Carburetor. Fig. 45. New Model of Schebler Carburetor With Metering Valve and Extended Venturi. Note Mechanical Connection Between Air Valve and Fuel Regulating Needle. Fig. 46. The Claudel Carburetor. Fig. 47. The Stewart Metering Pin Carburetor. Fig. 48. The Ball and Ball Two-Stage Carburetor. Fig. 49. The Master Carburetor. Fig. 50. Sectional View of Master Carburetor Showing Parts. Fig. 51. Sectional View of Zenith Compound Nozzle Compensating Carburetor. Fig. 52. Diagrams Explaining Action of Baverey Compound Nozzle Used in Zenith Carburetor. Fig. 53. The Zenith Duplex Carburetor for Airplane Motors of the V Type. Fig. 54. Rear View of Curtiss OX-2 90 Horse-Power Airplane Motor Showing Carburetor Location and Hot Air Leads. Fig. 55. Types of Strainers Interposed Between Vaporizer and Gasoline Tank to Prevent Water or Dirt Passing Into Carbureting Device. Fig. 56. Chart Showing Diminution of Air Pressure as Altitude Increases. Fig. 57. Some Simple Experiments to Demonstrate Various Magnetic Phenomena and Clearly Outline Effects of Magnetism and Various Forms of Magnets. Fig. 58. Elementary Form of Magneto Showing Principal Parts Simplified to Make Method of Current Generation Clear. Fig. 59. Showing How Strength of Magnetic Influence and of the Currents Induced in the Windings of Armature Vary with the Rapidity of Changes of Flow. Fig. 60. Diagrams Explaining Action of Low Tension Transformer Coil and True High Tension Magneto Ignition Systems. Fig. 60A. Side Sectional View of Bosch High-Tension Magneto Shows Disposition of Parts. End Elevation Depicts Arrangement of Interruptor and Distributor Mechanism. Fig. 61. Berling Two-Spark Dual Ignition System. Fig. 62. Berling Double-Spark Independent System. Fig. 63. Type DD Berling High Tension Magneto. Fig. 64. Wiring Diagrams of Berling Magneto Ignition Systems. Fig. 65. The Berling Magneto Breaker Box Showing Contact Points Separated and Interruptor Lever on Cam. Fig. 66. The Dixie Model 60 for Six-Cylinder Airplane Engine Ignition. Fig. 67. Installation Dimensions of Dixie Model 60 Magneto. Fig. 68. The Rotating Elements of the Dixie Magneto. Fig. 69. Suggestions for Adjusting and Dismantling Dixie Magneto. A--Screw Driver Adjusts Contact Points. B--Distributor Block Removed. C--Taking off Magnets. D--Showing How Easily Condenser and High Tension Windings are Removed. Fig. 69A. Sectional Views Outlining Construction of Dixie Magneto with Compound Distributor for Eight-Cylinder Engine Ignition. Fig. 70. Wiring Diagram of Dixie Magneto Installation on Hall-Scott Six-Cylinder 125 Horse-Power Aeronautic Motor. Fig. 71. How Magneto Ignition is Installed on Thomas-Morse 135 Horse-Power Motor. Fig. 72. Spark-Plug Types Showing Construction and Arrangement of Parts. Fig. 73. Standard Airplane Engine Plug Suggested by S. A. E. Standards Committee. Fig. 74. Special Mica Plug for Aviation Engines. Fig. 75. Showing Use of Magnifying Glass to Demonstrate that Apparently Smooth Metal Surfaces May Have Minute Irregularities which Produce Friction. Fig. 76. Pressure Feed Oiling System of Thomas Aviation Engine Includes Oil Cooling Means. Fig. 77. Diagram of Oiling System, Hall-Scott Type A 125 Horse-Power Engine. Fig. 78. Sectional View of Typical Motor Showing Parts Needing Lubrication and Method of Applying Oil by Constant Level Splash System. Note also Water Jacket and Spaces for Water Circulation. Fig. 79. Pressure Feed Oil-Supply System of Airplane Power Plants has Many Good Features. Fig. 80. Why Pressure Feed System is Best for Eight-Cylinder Vee Airplane Engines. Fig. 81. Operating Temperatures of Automobile Engine Parts Useful as a Guide to Understand Airplane Power Plant Heat. Fig. 82. Water Cooling of Salmson Seven-Cylinder Radial Airplane Engine. Fig. 83. How Water Cooling System of Thomas Airplane Engine is Installed in Fuselage. Fig. 84. Finned Tube Radiators at the Side of Hall-Scott Airplane Power Plant Installed in Standard Fuselage. Fig. 85. Anzani Testing His Five-Cylinder Air Cooled Aviation Motor Installed in Bleriot Monoplane. Note Exposure of Flanged Cylinders to Propeller Slip Stream. Fig. 86. Views of Four-Cylinder Duesenberg Airplane Engine Cylinder Block. Fig. 87. Twin-Cylinder Block of Sturtevant Airplane Engine is Cast of Aluminum, and Has Removable Cylinder Head. Fig. 88. Aluminum Cylinder Pair Casting of Thomas 150 Horse-Power Airplane Engine is of the L Head Type. Fig. 90. Cross Section of Austro-Daimler Engine, Showing Offset Cylinder Construction. Note Applied Water Jacket and Peculiar Valve Action. Fig. 91. Diagrams Demonstrating Advantages of Offset Crank-Shaft Construction. Fig. 92. Diagram Showing Forms of Cylinder Demanded by Different Valve Placings. A--T Head Type, Valves on Opposite Sides. B--L Head Cylinder, Valves Side by Side. C--L Head Cylinder, One Valve in Head, Other in Pocket. D--Inlet Valve Over Exhaust Member, Both in Side Pocket. E--Valve-in-the-Head Type with Vertical Valves. F--Inclined Valves Placed to Open Directly into Combustion Chamber. Fig. 93. Sectional View of Engine Cylinder Showing Valve and Cage Installation. Fig. 94. Diagrams Showing How Gas Enters Cylinder Through Overhead Valves and Other Types. A--Tee Head Cylinder. B--L Head Cylinder. C--Overhead Valve. Fig. 95. Conventional Methods of Operating Internal Combustion Motor Valves. Fig. 96. Examples of Direct Valve Actuation by Overhead Cam-Shaft. A--Mercedes. B--Hall-Scott. C--Wisconsin. Fig. 97. CENSORED Fig. 98. CENSORED Fig. 99. Sectional Views Showing Arrangement of Novel Concentric Valve Arrangement Devised by Panhard for Aerial Engines. Fig. 100. Showing Clearance Allowed Between Valve Stem and Valve Stem Guide to Secure Free Action. Fig. 101. Forms of Valve-Lifting Cams Generally Employed. A--Cam Profile for Long Dwell and Quick Lift. B--Typical Inlet Cam Used with Mushroom Type Follower. C--Average Form of Cam. D--Designed to Give Quick Lift and Gradual Closing. Fig. 102. Showing Principal Types of Cam Followers which Have Received General Application. Fig. 103. Diagram Showing Proper Clearance to Allow Between Adjusting Screw and Valve Stems in Hall-Scott Aviation Engines. Fig. 104. Cam-Shaft of Thomas Airplane Motor Has Cams Forged Integral. Note Split Cam-Shaft Bearings and Method of Gear Retention. Fig. 105. Section Through Cylinder of Knight Motor, Showing Important Parts of Valve Motion. Fig. 106. Diagrams Showing Knight Sleeve Valve Action. Fig. 107. Cross Sectional View of Knight Type Eight Cylinder V Engine. Fig. 108. Diagrams Explaining Valve and Ignition Timing of Hall-Scott Aviation Engine. Fig. 109. Timing Diagram of Typical Six-Cylinder Engine. Fig. 110. Timing Diagram of Typical Eight-Cylinder V Engine. Fig. 111. Timing Diagram Showing Peculiar Valve Timing of Gnome "Monosoupape" Rotary Motor. Fig. 112. Two Methods of Operating Valves by Positive Cam Mechanism Which Closes as Well as Opens Them. Fig. 113. Diagram Comparing Two Large Valves and Four Small Ones of Practically the Same Area. Note How Easily Small Valves are Installed to Open Directly Into the Cylinder. Fig. 114. Sectional Views of Sixteen-Valve Four-Cylinder Automobile Racing Engine That May Have Possibilities for Aviation Service. Fig. 115. Front View of Curtiss OX-3 Aviation Motor, Showing Unconventional Valve Action by Concentric Push Rod and Pull Tube. Fig. 116. Forms of Pistons Commonly Employed in Gasoline Engines. A--Dome Head Piston and Three Packing Rings. B--Flat Top Form Almost Universally Used. C--Concave Piston Utilized in Knight Motors and Some Having Overhead Valves. D--Two-Cycle Engine Member with Deflector Plate Cast Integrally. E--Differential of Two-Diameter Piston Used in Some Engines Operating on Two-Cycle Principle. Fig. 117. Typical Methods of Piston Pin Retention Generally Used in Engines of American Design. A--Single Set Screw and Lock Nut. B--Set Screw and Check Nut Fitting Groove in Wrist Pin. C, D--Two Locking Screws Passing Into Interior of Hollow Wrist Pin. E--Split Ring Holds Pin in Place. F--Use of Taper Expanding Plugs Outlined. G--Spring Pressed Plunger Type. H--Piston Pin Pinned to Connecting Rod. I--Wrist Pin Clamped in Connecting Rod Small End by Bolt. Fig. 118. Typical Piston and Connecting Rod Assembly. Fig. 119. Parts of Sturtevant Aviation Engine. A--Cylinder Head Showing Valves. B--Connecting Rod. C--Piston and Rings. Fig. 120. Aluminum Piston and Light But Strong Steel Connecting Rod and Wrist Pin of Thomas Aviation Engine. Fig. 121. Cast Iron Piston of "Monosoupape" Gnome Engine Installed On One of the Short Connecting Rods. Fig. 122. Types of Aluminum Pistons Used In Aviation Engines. Fig. 123. Types of Piston Rings and Ring Joints. A--Concentric Ring. B--Eccentrically Machined Form. C--Lap Joint Ring. D--Butt Joint, Seldom Used. E--Diagonal Cut Member, a Popular Form. Fig. 124. Diagrams Showing Advantages of Concentric Piston Rings. Fig. 125. Leak-Proof and Other Compound Piston Rings. Fig. 126. Sectional View of Engine Showing Means of Preventing Oil Leakage By Piston Rings. Fig. 127. Connecting Rod and Crank-Shaft Construction of Gnome "Monosoupape" Engine. Fig. 128. Connecting Rod Types Summarized. A--Single Connecting Rod Made in One Piece, Usually Fitted in Small Single-Cylinder Engines Having Built-Up Crank-Shafts. B--Marine Type, a Popular Form on Heavy Engines. C--Conventional Automobile Type, a Modified Marine Form. D--Type Having Hinged Lower Cap and Split Wrist Pin Bushing. E--Connecting Rod Having Diagonally Divided Big End. F--Ball-Bearing Rod. G--Sections Showing Structural Shapes Commonly Employed in Connecting Rod Construction. Fig. 129. Double Connecting Rod Assembly For Use On Single Crank-Pin of Vee Engine. Fig. 130. Another Type of Double Connecting Rod for Vee Engines. Fig. 131. Part Sectional View of Wisconsin Aviation Engine, Showing Four-Bearing Crank-Shaft, Overhead Cam-Shaft, and Method of Combining Cylinders in Pairs. Fig. 132. Part Sectional View of Renault Twelve-Cylinder Water-Cooled Engine, Showing Connecting Rod Construction and Other Important Internal Parts. Fig. 133. Typical Cam-Shaft, with Valve Lifting Cams and Gears to Operate Auxiliary Devices Forged Integrally. Fig. 134. Important Parts of Duesenberg Aviation Engine. A--Three Main Bearing Crank-Shaft. B--Cam-Shaft with Integral Cams. C--Piston and Connecting Rod Assembly. D--Valve Rocker Group. E--Piston. F--Main Bearing Brasses. Fig. 135. Showing Method of Making Crank-Shaft. A--The Rough Steel Forging Before Machining. B--The Finished Six-Throw, Seven-Bearing Crank-Shaft. Fig. 136. Showing Form of Crank-Shaft for Twin-Cylinder Opposed Power Plant. Fig. 137. Crank-Shaft of Thomas-Morse Eight-Cylinder Vee Engine. Fig. 138. Crank-Case and Crank-Shaft Construction for Twelve-Cylinder Motors. A--Duesenberg. B--Curtiss. Fig. 139. Counterbalanced Crank-Shafts Reduce Engine Vibration and Permit of Higher Rotative Speeds. Fig. 140. View of Thomas 135 Horse-Power Aeromotor, Model 8, Showing Conventional Method of Crank-Case Construction. Fig. 141. Views of Upper Half of Thomas Aeromotor Crank-Case. Fig. 142. Method of Constructing Eight-Cylinder Vee Engine, Possible if Aluminum Cylinder and Crank-Case Castings are Used. Fig. 143. Simple and Compact Crank-Case, Possible When Radial Cylinder Engine Design is Followed. Fig. 144. Unconventional Mounting of German Inverted Cylinder Motor. Fig. 145. How Curtiss Model OX-2 Motor is Installed in Fuselage of Curtiss Tractor Biplane. Note Similarity of Mounting to Automobile Power Plant. Fig. 146. Latest Model of Curtiss JN-4 Training Machine, Showing Thorough Enclosure of Power Plant and Method of Disposing of the Exhaust Gases. Fig. 147. Front View of L. W. F. Tractor Biplane Fuselage, Showing Method of Installing Thomas Aeromotor and Method of Disposing of Exhaust Gases. Fig. 148. End Elevation of Hall-Scott A-7 Four-Cylinder Motor, with Installation Dimensions. Fig. 149. Plan and Side Elevation of Hall-Scott A-7 Four-Cylinder Airplane Engine, with Installation Dimensions. Fig. 150. CENSORED Fig. 151. CENSORED Fig. 152. CENSORED Fig. 153. Plan View of Hall-Scott Type A-5 125 Horse-Power Airplane Engine, Showing Installation Dimensions. Fig. 154. Three-Quarter View of Hall-Scott Type A-5 125 Horse-Power Six-Cylinder Engine, with One of the Side Radiators Removed to Show Installation in Standard Fuselage. Fig. 155. Diagram Showing Proper Installation of Hall-Scott Type A-5 125 Horse-Power Engine with Pressure Feed Fuel Supply System. Fig. 156. Diagram Defining Installation of Gnome "Monosoupape" Motor in Tractor Biplane. Note Necessary Piping for Fuel, Oil, and Air Lines. Fig. 157. Showing Two Methods of Placing Propeller on Gnome Rotary Motor. Fig. 158. How Gnome Rotary Motor May Be Attached to Airplane Fuselage Members. Fig. 159. How Anzani Ten-Cylinder Radial Engine is Installed to Plate Securely Attached to Front End of Tractor Airplane Fuselage. Fig. 160. Side Elevation of Thomas 135 Horse-Power Airplane Engine, Giving Important Dimensions. Fig. 161. Front Elevation of Thomas-Morse 135 Horse-Power Aeromotor, Showing Main Dimensions. Fig. 162. Front and Side Elevations of Sturtevant Airplane Engine, Giving Principal Dimensions to Facilitate Installation. Fig. 163. Practical Hand Tools Useful in Dismantling and Repairing Airplane Engines. Fig. 164. Wrenches are Offered in Many Forms. Fig. 165. Illustrating Use and Care of Files. Fig. 166. Outlining Use of Cotter Pin Pliers, Spring Winder, and Showing Practical Outfit of Chisels. Fig. 167. Forms of Hand Operated Drilling Machines. Fig. 168. Forms of Drills Used in Hand and Power Drilling Machines. Fig. 169. Useful Set of Number Drills, Showing Stand for Keeping These in an Orderly Manner. Fig. 170. Illustrating Standard Forms of Hand and Machine Reamers. Fig. 171. Tools for Thread Cutting. Fig. 172. Showing Holder Designs for One- and Two-Piece Thread Cutting Dies. Fig. 173. Useful Outfit of Taps and Dies for the Engine Repair Shop. Fig. 174. Common Forms of Inside and Outside Calipers. Fig. 175. Measuring Appliances for the Machinist and Floor Man. Fig. 176. At Left, Special Form of Vernier Caliper for Measuring Gear Teeth; at Right, Micrometer for Accurate Internal Measurements. Fig. 177. Measuring Appliances of Value in Airplane Repair Work. Fig. 178. Standard Forms of Micrometer Caliper for External Measurements. Fig. 179. Special Tools for Maintaining Curtiss OX-2 Motor Used in Curtiss JN-4 Training Biplane. Fig. 180. Special Tools and Appliances to Facilitate Overhauling Work on Hall-Scott Airplane Engines. Fig. 181. Special Stand to Make Motor Overhauling Work Easier. Fig. 182. Showing Where Carbon Deposits Collect in Engine Combustion Chamber, and How to Burn Them Out with the Aid of Oxygen. A--Special Torch. B--Torch Coupled to Oxygen Tank. C--Torch in Use. Fig. 1821/2. Part Sectional View, Showing Valve Arrangement in Cylinder of Curtiss OX-2 Aviation Engine. Fig. 183. Tools for Restoring Valve Head and Seats. Fig. 184. Tools and Processes Utilized in Valve Grinding. Fig. 185. Outlining Points in Valve Operating Mechanism Where Depreciation is Apt to Exist. Fig. 186. Method of Removing Piston Rings, and Simple Clamp to Facilitate Insertion of Rings in Cylinder. Fig. 187. Tools and Processes Used in Refitting Engine Bearings. Fig. 188. Showing Points to Observe When Fitting Connecting Rod Brasses. Fig. 189. Methods of Testing to Insure Parallelism of Bearings After Fitting. Fig. 190. Views Outlining Construction of Three-Cylinder Anzani Aviation Motor. Fig. 190a. Illustrations Depicting Wrong and Right Methods of "Swinging the Stick" to Start Airplane Engine. At Top, Poor Position to Get Full Throw and Get Out of the Way. Below, Correct Position to Get Quick Turn Over of Crank-Shaft and Spring Away from Propeller. Fig. 191. The Anzani Six-Cylinder Water-Cooled Aviation Engine. Fig. 192. Sectional View of Anzani Six-Cylinder Water-Cooled Aviation Engine. Fig. 193. Three-Cylinder Anzani Air-Cooled Y-Form Engine. Fig. 194. Anzani Fixed Crank-Case Engine of the Six-Cylinder Form Utilizes Air Cooling Successfully. Fig. 195. Sectional View Showing Internal Parts of Six-Cylinder Anzani Engine, with Starwise Disposition of Cylinders. Fig. 196. The Anzani Ten-Cylinder Aviation Engine at the Left, and the Twenty-Cylinder Fixed Type at the Right. Fig. 197. Application of R. E. P. Five-Cylinder Fan-Shape Air-Cooled Motor to Early Monoplane. Fig. 198. The Canton and Unné Nine-Cylinder Water-Cooled Radial Engine. Fig. 199. Sectional View Showing Construction of Canton and Unné Water-Cooled Radial Cylinder Engine. Fig. 200. Sectional View Outlining Construction of Early Type Gnome Valve-in-Piston Type Motor. Fig. 201. Sectional View of Early Type Gnome Cylinder and Piston Showing Construction and Application of Inlet and Exhaust Valves. Fig. 202. Details of Old Style Gnome Motor Inlet and Exhaust Valve Construction and Operation. Fig. 203. The Gnome Fourteen-Cylinder 100 Horse-Power Aviation Engine. Fig. 204. Cam and Cam-Gear Case of the Gnome Seven-Cylinder Revolving Engine. Fig. 205. Diagrams Showing Why An Odd Number of Cylinders is Best for Rotary Cylinder Motors. Fig. 206. Simple Carburetor Used On Early Gnome Engines Attached to Fixed Crank-Shaft End. Fig. 207. Sectional Views of the Gnome Oil Pump. Fig. 208. Simplified Diagram Showing Gnome Motor Magneto Ignition System. Fig. 209. The G. V. Gnome "Monosoupape" Nine-Cylinder Rotary Engine Mounted on Testing Stand. Fig. 210. Sectional View Showing Construction of General Vehicle Co. "Monosoupape" Gnome Engine. Fig. 211. How a Gnome Cylinder is Reduced from Solid Chunk of Steel Weighing 97 Pounds to Finished Cylinder Weighing 51/2 Pounds. Fig. 212. The Gnome Engine Cam-Gear Case, a Fine Example of Accurate Machine Work. Fig. 213. G. V. Gnome "Monosoupape," with Cam-Case Cover Removed to Show Cams and Valve-Operating Plungers with Roller Cam Followers. Fig. 214. The 50 Horse-Power Rotary Bayerischen Motoren Gesellschaft Engine, a German Adaptation of the Early Gnome Design. Fig. 215. Nine-Cylinder Revolving Le Rhone Type Aviation Engine. Fig. 216. Part Sectional Views of Le Rhone Rotary Cylinder Engine, Showing Method of Cylinder Retention, Valve Operation and Novel Crank Disc Assembly. Fig. 217. Side Sectional View of Le Rhone Aviation Engine. Fig. 218. View Showing Le Rhone Valve Action and Connecting Rod Big End Arrangement. Fig. 219. Diagrams Showing Important Components of Le Rhone Motor. Fig. 220. How the Cams of the Le Rhone Motor Can Operate Two Valves with a Single Push Rod. Fig. 221. The Le Rhone Carburetor at A and Fuel Supply Regulating Device at B. Fig. 222. Diagrams Showing Le Rhone Motor Action and Firing Order. Fig. 223. Diagram Showing Positions of Piston in Le Rhone Rotary Cylinder Motor. Fig. 224. Diagrams Showing Valve Timing of Le Rhone Aviation Engine. Fig. 225. Diagrams Showing How Cylinder Cooling is Effected in Renault Vee Engines. Fig. 226. End Sectional View of Renault Air-Cooled Aviation Engine. Fig. 227. Side Sectional View of Renault Twelve-Cylinder Air-Cooled Aviation Engine Crank-Case, Showing Use of Plain and Ball Bearings for Crank-Shaft Support. Fig. 228. End View of Renault Twelve-Cylinder Engine Crank-Case, Showing Magneto Mounting. Fig. 229. Diagram Outlining Renault Twelve-Cylinder Engine Ignition System. Fig. 230. The Simplex Model A Hispano-Suiza Aviation Engine, a Very Successful Form. Fig. 231. The Curtiss OXX-5 Aviation Engine is an Eight-Cylinder Type Largely Used on Training Machines. Fig. 232. Top and Bottom Views of the Curtiss OXX-5 100 Horse-Power Aviation Engine. Fig. 233. End View of Thomas-Morse 150 Horse-Power Aluminum Cylinder Aviation Motor Having Detachable Cylinder Heads. Fig. 234. Side View of Thomas-Morse High Speed 150 Horse-Power Aviation Motor with Geared Down Propeller Drive. Fig. 235. The Reduction Gear-Case of Thomas-Morse 150 Horse-Power Aviation Motor, Showing Ball Bearing and Propeller Drive Shaft Gear. Fig. 236. The Six-Cylinder Aeromarine Engine. Fig. 237. The Wisconsin Aviation Engine, at Top, as Viewed from Carburetor Side. Below, the Exhaust Side. Fig. 238. Dimensioned End Elevation of Wisconsin Six Motor. Fig. 239. Dimensioned Side Elevation of Wisconsin Six Motor. Fig. 240. Power, Torque and Efficiency Curves of Wisconsin Aviation Motor. Fig. 241. Timing Diagram, Wisconsin Aviation Engine. Fig. 242. Dimensioned End View of Wisconsin Twelve-Cylinder Airplane Motor. Fig. 243. Dimensioned Side Elevation of Wisconsin Twelve-Cylinder Airplane Motor. Fig. 244. Side and End Sectional Views of Four-Cylinder Argus Engine, a German 100 Horse-Power Design Having Bore and Stroke of 140 mm., or 5.60 inches, and Developing Its Power at 1,368 R.P.M. Weight, 350 Pounds. Fig. 245. Part Sectional View of 90 Horse-Power Mercedes Engine, Which is Typical of the Design of Larger Sizes. Fig. 246. Part Sectional Side View and Sectional End View of Benz 160 Horse-Power Aviation Engine. Fig. 247. At Top, the Sunbeam Overhead Valve 170 Horse-Power Six-Cylinder Engine. Below, Side View of Sunbeam 350 Horse-Power Twelve-Cylinder Vee Engine. Fig. 248. Side View of Eighteen-Cylinder Sunbeam Coatalen Aircraft Engine Rated at 475 B.H.P. Fig. 249. Sunbeam Eighteen-Cylinder Motor, Viewed from Pump and Magneto End. Fig. 250. Propeller End of Sunbeam Eighteen-Cylinder 475 B.H.P. Aviation Engine. Fig. 251. View of Airplane Cowl Board, Showing the Various Navigating and Indicating Instruments to Aid the Aviator in Flight. Fig. 252. Parts of Christensen Air Starting System Shown at A, and Application of Piping and Check Valves to Cylinders of Thomas-Morse Aeromotor Outlined at B. Fig. 253. Diagrams Showing Installation of Air Starting System on Thomas-Morse Aviation Motor. CATALOGUE _Of the_ LATEST _and_ BEST PRACTICAL _and_ MECHANICAL BOOKS _Including Automobile and Aviation Books_ [Illustration] _Any of these books will be sent prepaid to any part of the world, on receipt of price. Remit by Draft, Postal Order, Express Order or Registered Letter_ Published and For Sale By The Norman W. Henley Publishing Co., 2 West 45th Street, New York, U.S.A. INDEX PAGES Air Brakes 21, 24 Arithmetic 14, 25, 31 Automobile Books 3, 4, 5, 6 Automobile Charts 6, 7 Automobile Ignition Systems 5 Automobile Lighting 5 Automobile Questions and Answers 4 Automobile Repairing 4 Automobile Starting Systems 5 Automobile Trouble Charts 5, 6 Automobile Welding 5 Aviation 7 Aviation Chart 7 Batteries, Storage 5 Bevel Gear 19 Boiler-Room Chart 9 Brazing 7 Cams 19 Carburetion Trouble Chart 6 Change Gear 19 Charts 6, 7, 8 Coal 22 Coke 9 Combustion 22 Compressed Air 10 Concrete 10, 11, 12 Concrete for Farm Use 11 Concrete for Shop Use 11 Cosmetics 27 Cyclecars 5 Dictionary 12 Dies 12, 13 Drawing 13, 14 Drawing for Plumbers 28 Drop Forging 13 Dynamo Building 14 Electric Bells 14 Electric Switchboards 14, 16 Electric Toy Making 15 Electric Wiring 14, 15, 16 Electricity 14, 15, 16, 17 Encyclopedia 24 E-T Air Brake 24 Every-day Engineering 34 Factory Management 17 Ford Automobile 3 Ford Trouble Chart 6 Formulas and Recipes 29 Fuel 17 Gas Construction 18 Gas Engines 18, 19 Gas Tractor 33 Gearing and Cams 19 Glossary of Aviation Terms 7, 12 Heating 31, 32 Horse-Power Chart 9 Hot-Water Heating 31, 32 House Wiring 15, 17 How to Run an Automobile 3 Hydraulics 5 Ice and Refrigeration 20 Ignition Systems 5 Ignition-Trouble Chart 6 India Rubber 30 Interchangeable Manufacturing 24 Inventions 20 Knots 20 Lathe Work 20 Link Motions 22 Liquid Air 21 Locomotive Boilers 22 Locomotive Breakdowns 22 Locomotive Engineering 21, 22, 23, 24 Machinist Book 24, 25, 26 Magazine, Mechanical 34 Manual Training 26 Marine Engineering 26 Marine Gasoline Engines 19 Mechanical Drawing 13, 14 Mechanical Magazine 34 Mechanical Movements 25 Metal Work 12, 13 Motorcycles 5, 6 Patents 20 Pattern Making 27 Perfumery 27 Perspective 13 Plumbing 28, 29 Producer Gas 19 Punches 13 Questions and Answers on Automobile 4 Questions on Heating 32 Railroad Accidents 23 Railroad Charts 9 Recipe Book 29 Refrigeration 20 Repairing Automobiles 4 Rope Work 20 Rubber 30 Rubber Stamps 30 Saw Filing 30 Saws, Management of 30 Sheet-Metal Works 12, 13 Shop Construction 25 Shop Management 25 Shop Practice 25 Shop Tools 25 Sketching Paper 14 Soldering 7 Splices and Rope Work 20 Steam Engineering 30, 31 Steam Heating 31, 32 Steel 32 Storage Batteries 5 Submarine Chart 9 Switchboards 14, 16 Tapers 21 Telegraphy, Wireless 17 Telephone 16 Thread Cutting 26 Tool Making 24 Toy Making 15 Train Rules 23 Tractive Power Chart 9 Tractor, Gas 33 Turbines 33 Vacuum Heating 32 Valve Setting 22 Ventilation 31 Watch Making 33 Waterproofing 12 Welding with Oxy-acetylene Flame 5, 33 Wireless Telegraphy 17 Wiring 14, 15 Wiring Diagrams 14 Any of these books promptly sent prepaid to any address in the world on receipt of price. =HOW TO REMIT=--By Postal Money Order, Express Money Order, Bank Draft or Registered Letter. ~AUTOMOBILES AND MOTORCYCLES~ =The Modern Gasoline Automobile--Its Design, Construction, and Operation, 1918 Edition.= By VICTOR W. PAGÉ, M.S.A.E. This is the most complete, practical and up-to-date treatise on gasoline automobiles and their component parts ever published. In the new _revised_ and _enlarged_ 1918 _edition_, all phases of automobile construction, operation and maintenance are fully and completely described, and in language anyone can understand. Every part of all types of automobiles, from light cycle-cars to heavy motor trucks and tractors, are described in a thorough manner, not only the automobile, but every item of it; equipment, accessories, tools needed, supplies and spare parts necessary for its upkeep, are fully discussed. _It is clearly and concisely written by an expert familiar with every branch of the automobile industry and the originator of the practical system of self-education on technical subjects. It is a liberal education in the automobile art, useful to all who motor for either business or pleasure._ Anyone reading the incomparable treatise is in touch with all improvements that have been made in motor-car construction. All latest developments, such as high speed aluminum motors and multiple valve and sleeve-valve engines, are considered in detail. The latest ignition, carburetor and lubrication practice is outlined. New forms of change speed gears, and final power transmission systems, and all latest chassis improvements are shown and described. This book is used in all leading automobile schools and is conceded to be the STANDARD TREATISE. The chapter on Starting and Lighting Systems has been greatly enlarged, and many automobile engineering features that have long puzzled laymen are explained so clearly that the underlying principles can be understood by anyone. This book was first published six years ago and so much new matter has been added that it is nearly twice, its original size. The only treatise covering various forms of war automobiles and recent developments in motor-truck design as well as pleasure cars. _This book is not too technical for the layman nor too elementary for the more expert. It is an incomparable work of reference, for home or school_. 1,000 6x9 pages, nearly 1,000 illustrations, 12 folding plates. Cloth bound. Price =$3.00= WHAT IS SAID OF THIS BOOK: "It is the best book on the Automobile seen up to date."--J. H. Pile, Associate Editor _Automobile Trade Journal_. "Every Automobile Owner has use for a book of this character."--_The Tradesman_. "This book is superior to any treatise heretofore published on the subject."--_The Inventive Age_. "We know of no other volume that is so complete in all its departments, and in which the wide field of automobile construction with its mechanical intricacies is so plainly handled, both in the text and in the matter of illustrations."--_The Motorist_. "The book is very thorough, a careful examination failing to disclose any point in connection with the automobile, its care and repair, to have been overlooked."--_Iron Age_. "Mr. Pagé has done a great work, and benefit to the Automobile Field."--W. C. Hasford, Mgr. Y. M. C. A. Automobile School, Boston, Mass. "It is just the kind of a book a motorist needs if he wants to understand his car."--_American Thresherman_. =The Model T Ford Car, Its Construction, Operation and Repair.= By VICTOR W. PAGÉ, M.S.A.E. This is a complete instruction book. All parts of the Ford Model T Car are described and illustrated; the construction is fully described and operating principles made clear to everyone. Every Ford owner needs this practical book. You don't have to guess about the construction or where the trouble is, as it shows how to take all parts apart and how to locate and fix all faults. The writer, Mr. Pagé, has operated a Ford car for many years and writes from actual knowledge. Among the contents are: 1. The Ford Car: Its Parts and Their Functions. 2. The Engine and Auxiliary Groups. How the Engine Works--The Fuel Supply System--The Carburetor--Making the Ignition Spark--Cooling and Lubrication. 3. Details of Chassis. Change Speed Gear--Power Transmission--Differential Gear Action--Steering Gear--Front Axle--Frame and Springs--Brakes. 4. How to Drive and Care for the Ford. The Control System Explained--Starting the Motor--Driving the Car--Locating Roadside Troubles--Tire Repairs--Oiling the Chassis--Winter Care of Car. 5. Systematic Location of Troubles and Remedies. Faults in Engine--Faults in Carburetor--Ignition Troubles--Cooling and Lubrication System Defects--Adjustment of Transmission Gear--General Chassis Repairs. 95 illustrations, 300 pages, 2 large folding plates. Price =$1.00= =How to Run an Automobile.= By VICTOR W. PAGÉ, M.S.A.E. This treatise gives concise instructions for starting and running all makes of gasoline automobiles, how to care for them, and gives distinctive features of control. Describes every step for shifting gears, controlling engines, etc. Among the chapters contained are: I.--Automobile Parts and Their Functions. II.--General Starting and Driving Instructions. III.--Typical 1917 Control Systems. IV.--Care of Automobiles. 178 pages. 72 specially made illustrations. Price =$1.00= =Automobile Repairing Made Easy.= By VICTOR W. PAGÉ, M.S.A.E. A comprehensive, practical exposition of every phase of modern automobile repairing practice. Outlines every process incidental to motor car restoration. Gives plans for workshop construction, suggestions for equipment, power needed, machinery and tools necessary to carry on business successfully. Tells how to overhaul and repair all parts of all automobiles. Everything is explained so simply that motorists and students can acquire a full working knowledge of automobile repairing. This work starts with the engine, then considers carburetion, ignition, cooling and lubrication systems. The clutch, change speed gearing and transmission system are considered in detail. Contains instructions for repairing all types of axles, steering gears and other chassis parts. Many tables, short cuts in figuring and rules of practice are given for the mechanic. Explains fully valve and magneto timing, "tuning" engines, systematic location of trouble, repair of ball and roller bearings, shop kinks, first aid to injured and a multitude of subjects of interest to all in the garage and repair business. _This book contains special instructions on electric starting_, _lighting and ignition systems_, tire _repairing and rebuilding_, _autogenous welding_, _brazing and soldering_, _heat treatment of steel_, _latest timing practice_, _eight and twelve-cylinder motors_, _etc._ 5-3/4x8. Cloth. 1,056 pages, 1,000 illustrations, 11 folding plates. Price =$3.00= WHAT IS SAID OF THIS BOOK: "'Automobile Repairing Made Easy' is the best book on the subject I have ever seen and the only book I ever saw that is of any value in a garage."--Fred Jeffrey, Martinsburg, Neb. "I wish to thank you for sending me a copy of 'Automobile Repairing Made Easy.' I do not think it could be excelled."--S. W. Gisriel, Director of Instruction, Y. M. C. A., Philadelphia, Pa. =Questions and Answers Relating to Modern Automobile Construction, Driving and Repair.= By VICTOR W. PAGÉ, M.S.A.E. A practical self-instructor for students, mechanics and motorists, consisting of thirty-seven lessons in the form of questions and answers, written with special reference to the requirements of the non-technical reader desiring easily understood, explanatory matter relating to all branches of automobiling. The subject-matter is absolutely correct and explained in simple language. If you can't answer all of the following questions, you need this work. The answers to these and over 2,000 more are to be found in its pages. Give the name of all important parts of an automobile and describe their functions. Describe action of latest types of kerosene carburetors. What is the difference between a "double" ignition system and a "dual" ignition system? Name parts of an induction coil. How are valves timed? What is an electric motor starter and how does it work? What are advantages of worm drive gearing? Name all important types of ball and roller bearings. What is a "three-quarter" floating axle? What is a two-speed axle? What is the Vulcan electric gear shift? Name the causes of lost power in automobiles. Describe all noises due to deranged mechanism and give causes? How can you adjust a carburetor by the color of the exhaust gases? What causes "popping" in the carburetor? What tools and supplies are needed to equip a car? How do you drive various makes of cars? What is a differential lock and where is it used? Name different systems of wire wheel construction, etc., etc. A popular work at a popular price. 5-1/4x7-1/2. Cloth. 650 pages, 350 illustrations, 3 folding plates. Price =$1.50= WHAT IS SAID OF THIS BOOK: "If you own a car--get this book."--_The Glassworker_. "Mr. Page has the faculty of making difficult subjects plain and understandable."--_Bristol Press_. "We can name no writer better qualified to prepare a book of instruction on automobiles than Mr. Victor W. Pagé."--_Scientific American_. "The best automobile catechism that has appeared."--_Automobile Topics_. "There are few men, even with long experience, who will not find this book useful. Great pains have been taken to make it accurate. Special recommendation must be given to the illustrations, which have been made specially for the work. Such excellent books as this greatly assist in fully understanding your automobile."--_Engineering News_. =The Automobilist's Pocket Companion and Expense Record.= Arranged by VICTOR W. PAGÉ, M.S.A.E. This book is not only valuable as a convenient cost record but contains much information of value to motorists. Includes a condensed digest of auto laws of all States, a lubrication schedule, hints for care of storage battery and care of tires, location of road troubles, anti-freezing solutions, horse-power table, driving hints and many useful tables and recipes of interest to all motorists. Not a technical book in any sense of the word, just a collection of practical facts in simple language for the everyday motorist. Price =$1.00= =Modern Starting, Lighting and Ignition Systems.= By VICTOR W. PAGÉ, M.E. This practical volume has been written with special reference to the requirements of the non-technical reader desiring easily understood, explanatory matter, relating to all types of automobile ignition, starting and lighting systems. It can be understood by anyone, even without electrical knowledge, because elementary electrical principles are considered before any attempt is made to discuss features of the various systems. These basic principles are clearly stated and illustrated with simple diagrams. _All the leading systems of starting, lighting and ignition have been described and illustrated with the co-operation of the experts employed by the manufacturers._ Wiring diagrams are shown in both technical and non-technical forms. All symbols are fully explained. It is a comprehensive review of modern starting and ignition system practice, and includes a complete exposition of storage battery construction, care and repair. All types of starting motors, generators, magnetos, and all ignition or lighting system-units are fully explained. _Every person in the automobile business needs this volume._ Among some of the subjects treated are: I.--Elementary Electricity; Current Production; Flow; Circuits; Measurements; Definitions; Magnetism; Battery Action; Generator Action. II.--Battery Ignition Systems. III.--Magneto Ignition Systems. IV.--Elementary Exposition of Starting System Principles. V.--Typical Starting and Lighting Systems; Practical Application; Wiring Diagrams; Auto-lite, Bijur, Delco, Dyneto-Entz, Gray and Davis, Remy, U. S. L., Westinghouse, Bosch-Rushmore, Genemotor, North-East, etc. VI.--Locating and Repairing Troubles in Starting and Lighting Systems. VII.--Auxiliary. Electric Systems; Gear-shifting by Electricity; Warning Signals; Electric Brake; Entz-Transmission, Wagner-Saxon Circuits, Wagner-Studebaker Circuits. 5-1/4x7-1/2. Cloth. 530 pages, 297 illustrations, 3 folding plates. Price =$1.50= =Automobile Welding With the Oxy-Acetylene Flame.= By M. KEITH DUNHAM. This is the only complete book on the "why" and "how" of Welding with the Oxy-Acetylene Flame, and from its pages one can gain information so that he can weld anything that comes along. No one can afford to be without this concise book, as it first explains the apparatus to be used, and then covers in detail the actual welding of all automobile parts. The welding of aluminum, cast iron, steel, copper, brass and malleable iron is clearly explained, as well as the proper way to burn the carbon out of the combustion head of the motor. Among the contents are: Chapter I.--Apparatus Knowledge. Chapter II.--Shop Equipment and Initial Procedure. Chapter III.--Cast Iron. Chapter IV.--Aluminum. Chapter V.--Steel. Chapter VI.--Malleable Iron, Copper, Brass, Bronze. Chapter VII.--Carbon Burning and other Uses of Oxygen and Acetylene. Chapter VIII.--How to Figure Cost of Welding. 167 pages, fully illustrated. Price =$1.00= =Storage Batteries Simplified.= By VICTOR W. PAGÉ, M.S.A.E. A comprehensive treatise devoted entirely to secondary batteries and their maintenance, repair and use. This is the most up-to-date book on this subject. Describes fully the Exide, Edison, Gould, Willard, U. S. L. and other storage battery forms in the types best suited for automobile, stationary and marine work. Nothing of importance has been omitted that the reader should know about the practical operation and care of storage batteries. No details have been slighted. The instructions for charging and care have been made as simple as possible. Brief Synopsis of Chapters: Chapter I.--Storage Battery Development; Types of Storage Batteries; Lead Plate Types; The Edison Cell. Chapter II.--Storage Battery Construction; Plates and Girds; Planté Plates; Fauré Plates; Non-Lead Plates; Commercial Battery Designs. Chapter III.--Charging Methods; Rectifiers; Converters; Rheostats; Rules for Charging. Chapter IV.--Battery Repairs and Maintenance. Chapter V.--Industrial Application of Storage Batteries; Glossary of Storage Battery Terms. 208 Pages. Very Fully Illustrated. Price =$1.50 net=. =Motorcycles, Side Cars and Cyclecars; their Construction, Management and Repair.= By VICTOR W. PAGÉ, M.S.A.E. The only complete work published for the motorcyclist and cyclecarist. Describes fully all leading types of machines, their design, construction, maintenance, operation and repair. This treatise outlines fully the operation of two- and four-cycle power plants and all ignition, carburetion and lubrication systems in detail. Describes all representative types of free engine clutches, variable speed gears and power transmission systems. Gives complete instructions for operating and repairing all types. Considers fully electric self-starting and lighting systems, all types of spring frames and spring forks and shows leading control methods. For those desiring technical information a complete series of tables and many formulæ to assist in designing are included. The work tells how to figure power needed to climb grades, overcome air resistance and attain high speeds. It shows how to select gear ratios for various weights and powers, how to figure braking efficiency required, gives sizes of belts and chains to transmit power safely, and shows how to design sprockets, belt pulleys, etc. This work also includes complete formulæ for figuring horse-power, shows how dynamometer tests are made, defines relative efficiency of air and water-cooled engines, plain and anti-friction bearings and many other data of a practical, helpful, engineering nature. Remember that you get this information in addition to the practical description and instructions which alone are worth several times the price of the book. 550 pages. 350 specially made illustrations, 5 folding plates. Cloth. Price =$1.50= WHAT IS SAID OF THIS BOOK: "Here is a book that should be in the cycle repairer's kit."--_American Blacksmith._ "The best way for any rider to thoroughly understand his machine, is to get a copy of this book; it is worth many times its price."--_Pacific Motorcyclist._ ~AUTOMOBILE AND MOTORCYCLE CHARTS~ =Chart. Location of Gasoline Engine Troubles Made Easy--A Chart Showing Sectional View of Gasoline Engine.= Compiled by VICTOR W. PAGÉ, M.S.A.E. It shows clearly all parts of a typical four-cylinder gasoline engine of the four-cycle type. It outlines distinctly all parts liable to give trouble and also details the derangements apt to interfere with smooth engine operation. Valuable to students, motorists, mechanics, repairmen, garagemen, automobile salesmen, chauffeurs, motorboat owners, motor-truck and tractor drivers, aviators, motor-cyclists, and all others who have to do with gasoline power plants. It simplifies location of all engine troubles, and while it will prove invaluable to the novice, it can be used to advantage by the more expert. It should be on the walls of every public and private garage, automobile repair shop, club house or school. It can be carried in the automobile or pocket with ease, and will insure against loss of time when engine trouble manifests itself. This sectional view of engine is a complete review of all motor troubles. It is prepared by a practical motorist for all who motor. More information for the money than ever before offered. No details omitted. Size 25x38 inches. Securely mailed on receipt of =25 Cents= =Chart. Location of Ford Engine Troubles Made Easy.= Compiled by VICTOR W. PAGÉ, M.S.A.E. This shows clear sectional views depicting all portions of the Ford power plant and auxiliary groups. It outlines clearly all parts of the engine, fuel supply system, ignition group and cooling system, that are apt to give trouble, detailing all derangements that are liable to make an engine lose power, start hard or work irregularly. This chart is valuable to students, owners, and drivers, as it simplifies location of all engine faults. Of great advantage as an instructor for the novice, it can be used equally well by the more expert as a work of reference and review. It can be carried in the tool-box or pocket with ease and will save its cost in labor eliminated the first time engine trouble manifests itself. Prepared with special reference to the average man's needs and is a practical review of all motor troubles because it is based on the actual experience of an automobile engineer-mechanic with the mechanism the chart describes. It enables the non-technical owner or operator of a Ford car to locate engine derangements by systematic search, guided by easily recognized symptoms instead of by guesswork. It makes the average owner independent of the roadside repair shop when touring. Must be seen to be appreciated. Size 25x38 inches. Printed on heavy bond paper. Price =25 cents= =Chart. Lubrication of the Motor Car Chassis.= Compiled by VICTOR W. PAGÉ, M.S.A.E. This chart presents the plan view of a typical six-cylinder chassis of standard design and all parts are clearly indicated that demand oil, also the frequency with which they must be lubricated and the kind of oil to use. A practical chart for all interested in motor-car maintenance. Size 24x38 inches. Price =25 cents= =Chart. Location of Carburetion Troubles Made Easy.= Compiled by VICTOR W. PAGÉ, M.S.A.E. This chart shows all parts of a typical pressure feed fuel supply system and gives causes of trouble, how to locate defects and means of remedying them. Size 24x38 inches. Price =25 cents= =Chart. Location of Ignition System Troubles Made Easy.= Compiled by VICTOR W. PAGÉ, M.S.A.E. In this diagram all parts of a typical double ignition system using battery and magneto current are shown, and suggestions are given for readily finding ignition troubles and eliminating them when found. Size 24x38 inches. Price =25 cents= =Chart. Location of Cooling and Lubrication System Faults.= Compiled by VICTOR W. PAGÉ, M.S.A.E. This composite diagram shows a typical automobile power plant using pump circulated water-cooling system and the most popular lubrication method. Gives suggestions for curing all overheating and loss of power faults due to faulty action of the oiling or cooling group. Size 24x38 inches. Price =25 cents= =Chart. Motorcycle Troubles Made Easy.= Compiled by VICTOR W PAGÉ, M.S.A.E. A chart showing sectional view of a single-cylinder gasoline engine. This chart simplifies location of all power-plant troubles. A single-cylinder motor is shown for simplicity. It outlines distinctly all parts liable to give trouble and also details the derangements apt to interfere with smooth engine operation. This chart will prove of value to all who have to do with the operation, repair or sale of motorcycles. No details omitted. Size 30x20 inches Price =25 cents= ~AVIATION~ =Aviation Engines, their Design, Construction, Operation and Repair.= By Lieut. VICTOR W. PAGÉ, Aviation Section, S.C.U.S.R. A practical work containing valuable instructions for aviation students, mechanicians, squadron engineering officers and all interested in the construction and upkeep of airplane power plants. The rapidly increasing interest in the study of aviation, and especially of the highly developed internal combustion engines that make mechanical flight possible, has created a demand for a text-book suitable for schools and home study that will clearly and concisely explain the workings of the various aircraft engines of foreign and domestic manufacture. This treatise, written by a recognized authority on all of the practical aspects of internal combustion engine construction, maintenance and repair fills the need as no other book does. The matter is logically arranged; all descriptive matter is simply expressed and copiously illustrated so that anyone can understand airplane engine operation and repair even if without previous mechanical training. This work is invaluable for anyone desiring to become an aviator or aviation mechanician. The latest rotary types, such as the Gnome, Monosoupape, and Le Rhone, are fully explained, as well as the recently developed Vee and radial types. The subjects of carburetion, ignition, cooling and lubrication also are covered in a thorough manner. The chapters on repair and maintenance are distinctive and found in no other book on this subject. Invaluable to the student, mechanic and soldier wishing to enter the aviation service. Not a technical book, but a practical, easily understood work of reference for all interested in aeronautical science. 576 octavo pages. 253 specially made engravings. Price =$3.00 net= ~GLOSSARY OF AVIATION TERMS~ =Termes D'Aviation, English-French, French-English.= Compiled by Lieuts. VICTOR W. PAGÉ, A.S., S.C.U.S.R., and PAUL MONTARIOL of the French Flying Corps, on duty on Signal Corps Aviation School, Mineola, L. I. A complete, well illustrated volume intended to facilitate conversation between English-speaking and French aviators. A very valuable book for all who are about to leave for duty overseas. Approved for publication by Major W. G. Kilner, S.C., U.S.C.O. Signal Corps Aviation School. Hazelhurst Field, Mineola, L. I. This book should be in every Aviator's and Mechanic's Kit for ready reference. 128 pages. Fully illustrated with detailed engravings. Price =$1.00= =Aviation Chart. Location of Airplane Power Plant Troubles Made Easy.= By Lieut. VICTOR W. PAGÉ, A.S., S.C.U.S.R. A large chart outlining all parts of a typical airplane power plant, showing the points where trouble is apt to occur and suggesting remedies for the common defects. Intended especially for Aviators and Aviation Mechanics on School and Field Duty. Price =50 cents= ~BRAZING AND SOLDERING~ =Brazing and Soldering.= By JAMES F. HOBART. The only book that shows you just how to handle any job of brazing or soldering that comes along; it tells you what mixture to use, how to make a furnace if you need one. Full of valuable kinks. The fifth edition of this book has just been published, and to it much new matter and a large number of tested formulæ for all kinds of solders and fluxes have been added. Illustrated. Price =25 cents= ~CHARTS~ =Aviation Chart. Location of Airplane Power Plant Troubles Made Easy.= By Lieut. VICTOR W. PAGÉ, A.S., S.C.U.S.R. A large chart outlining all parts of a typical airplane power plant, showing the points where trouble is apt to occur and suggesting remedies for the common defects. Intended especially for Aviators and Aviation Mechanics on School and Field Duty. Price =50 cents= =Gasoline Engine Troubles Made Easy--A Chart Showing Sectional View of Gasoline Engine.= Compiled by Lieut. VICTOR W. PAGÉ, A.S., S.C.U.S.R. It shows clearly all parts of a typical four-cylinder gasoline engine of the four-cycle type. It outlines distinctly all parts liable to give trouble and also details the derangements apt to interfere with smooth engine operation. Valuable to students, motorists, mechanics, repairmen, garagemen, automobile salesmen, chauffeurs, motor-boat owners, motor-truck and tractor drivers, aviators, motor-cyclists, and all others who have to do with gasoline power plants. It simplifies location of all engine troubles, and while it will prove invaluable to the novice, it can be used to advantage by the more expert. It should be on the walls of every public and private garage, automobile repair shop, club house or school. It can be carried in the automobile or pocket with ease and will insure against loss of time when engine trouble manifests itself. This sectional view of engine is a complete review of all motor troubles. It is prepared by a practical motorist for all who motor. No details omitted. Size 25x38 inches. Price =25 cents= =Lubrication of the Motor Car Chassis.= This chart presents the plan view of a typical six-cylinder chassis of standard design and all parts are clearly indicated that demand oil, also the frequency with which they must be lubricated and the kind of oil to use. A practical chart for all interested in motor-car maintenance. Size 24x38 inches. Price =25 cents= =Location of Carburetion Troubles Made Easy.= This chart shows all parts of a typical pressure feed fuel supply system and gives causes of trouble, how to locate defects and means of remedying them. Size 24x38 inches. Price =25 cents= =Location of Ignition System Troubles Made Easy.= In this chart all parts of a typical double ignition system using battery and magneto current are shown and suggestions are given for readily finding ignition troubles and eliminating them when found. Size 24x38 inches. Price =25 cents= =Location of Cooling and Lubrication System Faults.= This composite chart shows a typical automobile power plant using pump circulated water-cooling system and the most popular lubrication method. Gives suggestions for curing all overheating and loss of power faults due to faulty action of the oiling or cooling group. Size 24x38 inches. Price =25 Cents= =Motorcycle Troubles Made Easy--A Chart Showing Sectional View of Single-Cylinder Gasoline Engine.= Compiled by VICTOR W. PAGÉ, M.S.A.E. This chart simplifies location of all power-plant troubles, and will prove invaluable to all who have to do with the operation, repair or sale of motorcycles. No details omitted. Size 25x38 inches. Price =25 cents= =Location of Ford Engine Troubles Made Easy.= Compiled by VICTOR W. PAGÉ, M.S.A.E. This shows clear sectional views depicting all portions of the Ford power plant and auxiliary groups. It outlines clearly all parts of the engine, fuel supply system, ignition group and cooling system, that are apt to give trouble, detailing all derangements that are liable to make an engine lose power, start hard or work irregularly. This chart is valuable to students, owners, and drivers, as it simplifies location of all engine faults. Of great advantage as an instructor for the novice, it can be used equally well by the more expert as a work of reference and review. It can be carried in the toolbox or pocket with ease and will save its cost in labor eliminated the first time engine trouble manifests itself. Prepared with special reference to the average man's needs and is a practical review of all motor troubles because it is based on the actual experience of an automobile engineer-mechanic with the mechanism the chart describes. It enables the non-technical owner or operator of a Ford car to locate engine derangements by systematic search, guided by easily recognized symptoms instead of by guesswork. It makes the average owner independent of the roadside repair shop when touring. Must be seen to be appreciated. Size 25x38 inches. Printed on heavy bond paper. Price =25 cents= =Modern Submarine Chart--with Two Hundred Parts Numbered and Named.= A cross-section view, showing clearly and distinctly all the interior of a Submarine of the latest type. You get more information from this chart, about the construction and operation of a Submarine, than in any other way. No details omitted--everything is accurate and to scale. It is absolutely correct in every detail, having been approved by Naval Engineers. All the machinery and devices fitted in a modern Submarine Boat are shown, and to make the engraving more readily understood all the features are shown in operative form, with Officers and Men in the act of performing the duties assigned to them in service conditions. This CHART IS REALLY AN ENCYCLOPEDIA OF A SUBMARINE. It is educational and worth many times its cost. Mailed in a Tube for =25 Cents= =Box Car Chart.= A chart showing the anatomy of a box car, having every part of the car numbered and its proper name given in a reference list. Price =25 Cents= =Gondola Car Chart.= A chart showing the anatomy of a gondola car, having every part of the car numbered and its proper reference name given in a reference list. Price =25 Cents= =Passenger-Car Chart.= A chart showing the anatomy of a passenger-car, having every part of the car numbered and its proper name given in a reference list =25 Cents= =Steel Hopper Bottom Coal Car.= A chart showing the anatomy of a steel Hopper Bottom Coal Car, having every part of the car numbered and its proper name given in a reference list. Price =25 Cents= =Tractive Power Chart.= A chart whereby you can find the tractive power or drawbar pull of any locomotive without making a figure. Shows what cylinders are equal, how driving wheels and steam pressure affect the power. What sized engine you need to exert a given drawbar pull or anything you desire in this line. Price =50 Cents= =Horse-Power Chart.= Shows the horse-power of any stationary engine without calculation. No matter what the cylinder diameter of stroke, the steam pressure of cut-off, the revolutions, or whether condensing or non-condensing, it's all there. Easy to use, accurate, and saves time and calculations. Especially useful to engineers and designers. Price =50 Cents= =Boiler Room Chart.= By GEO. L. FOWLER. A chart--size 14x28 inches--showing in isometric perspective the mechanisms belonging in a modern boiler room. The various parts are shown broken or removed, so that the internal construction is fully illustrated. Each part is given a reference number, and these, with the corresponding name, are given in a glossary printed at the sides. This chart is really a dictionary of the boiler room--the names of more than 200 parts being given. Price =25 Cents= ~COKE~ =Modern Coking Practice, Including Analysis of Materials and Products.= By J. E. CHRISTOPHER and T. H. BYROM. This, the standard work on the subject, has just been revised. It is a practical work for those engaged in Coke manufacture and the recovery of By-products. Fully illustrated with folding plates. It has been the aim of the authors, in preparing this book, to produce one which shall be of use and benefit to those who are associated with, or interested in, the modern developments of the industry. Among the Chapters contained in Volume I are: Introduction; Classification of Fuels; Impurities of Coals; Coal Washing; Sampling and Valuation of Coals, etc.; Power of Fuels; History of Coke Manufacture; Developments in the Coke Oven Design; Recent Types of Coke Ovens; Mechanical Appliances at Coke Ovens; Chemical and Physical Examination of Coke. Volume II covers fully the subject of By-Products. Price, per volume =$3.00 net= ~COMPRESSED AIR~ =Compressed Air in All Its Applications.= By GARDNER D. HISCOX. This is the most complete book on the subject of Air that has ever been issued, and its thirty-five chapters include about every phase of the subject one can think of. It may be called an encyclopedia of compressed air. It is written by an expert, who, in its 665 pages, has dealt with the subject in a comprehensive manner, no phase of it being omitted. Includes the physical properties of air from a vacuum to its highest pressure, its thermodynamics, compression, transmission and uses as a motive power, in the Operation of Stationary and Portable Machinery, in Mining, Air Tools, Air Lifts, Pumping of Water, Acids, and Oils; the Air Blast for Cleaning and Painting the Sand Blast and its Work, and the Numerous Appliances in which Compressed Air is a Most Convenient and Economical Transmitter of Power for Mechanical Work, Railway Propulsion, Refrigeration, and the Various Uses to which Compressed Air has been applied. Includes forty-four tables of the physical properties of air, its compression, expansion, and volumes required for various kinds of work, and a list of patents on compressed air from 1875 to date. Over 500 illustrations, 5th Edition, revised and enlarged. Cloth bound. Price =$5.00= Half Morocco. Price =$6.50= ~CONCRETE~ =Concrete Workers' Reference Books. A Series of Popular Handbooks for Concrete Users.= Prepared by A. A. HOUGHTON =50 cents= _The author, in preparing this Series, has not only treated on the usual types of construction, but explains and illustrates molds and systems that are not patented, but which are equal in value and often superior to those restricted by patents. These molds are very easily and cheaply constructed and embody simplicity, rapidity of operation, and the most successful results in the molded concrete. Each of these books is fully illustrated, and the subjects are exhaustively treated in plain English._ =Concrete Wall Forms.= By A. A. HOUGHTON. A new automatic wall clamp is illustrated with working drawings. Other types of wall forms, clamps, separators, etc., are also illustrated and explained. (No. 1 of Series) Price =50 cents= =Concrete Floors and Sidewalks.= By A. A. HOUGHTON. The molds for molding squares, hexagonal and many other styles of mosaic floor and sidewalk blocks are fully illustrated and explained. (No. 2 of Series) Price =50 cents= =Practical Concrete Silo Construction.= By A. A. HOUGHTON. Complete working drawings and specifications are given for several styles of concrete silos, with illustrations of molds for monolithic and block silos. The tables, data, and information presented in this book are of the utmost value in planning and constructing all forms of concrete silos. (No. 3 of Series) Price =50 cents= =Molding Concrete Chimneys, Slate and Hoof Tiles.= By A. A. HOUGHTON. The manufacture of all types of concrete slate and roof tile is fully treated. Valuable data on all forms of reinforced concrete roofs are contained within its pages. The construction of concrete chimneys by block and monolithic systems is fully illustrated and described. A number of ornamental designs of chimney construction with molds are shown in this valuable treatise. (No. 4 of Series.) Price =50 cents= =Molding and Curing Ornamental Concrete.= By A. A. HOUGHTON. The proper proportions of cement and aggregates for various finishes, also the method of thoroughly mixing and placing in the molds, are fully treated. An exhaustive treatise on this subject that every concrete worker will find of daily use and value. (No. 5 of Series.) Price =50 cents= =Concrete Monuments, Mausoleums and Burial Vaults.= By A. A. HOUGHTON. The molding of concrete monuments to imitate the most expensive cut stone is explained in this treatise with working drawings of easily built molds. Cutting inscriptions and designs are also fully treated. (No. 6 of Series.) Price =50 cents= =Molding Concrete Bathtubs, Aquariums and Natatoriums.= By A. A. HOUGHTON. Simple molds and instruction are given for molding many styles of concrete bathtubs, swimming-pools, etc. These molds are easily built and permit rapid and successful work. (No. 7 of Series.) Price =50 cents= =Concrete Bridges, Culverts and Sewers.= By A. A. HOUGHTON. A number of ornamental concrete bridges with illustrations of molds are given. A collapsible center or core for bridges, culverts and sewers is fully illustrated with detailed instructions for building. (No. 8 of Series.) Price =50 cents= =Constructing Concrete Porches.= By A. A. HOUGHTON. A number of designs with working drawings of molds are fully explained so any one can easily construct different styles of ornamental concrete porches without the purchase of expensive molds. (No. 9 of Series.) Price =50 cents= =Molding Concrete Flower-Pots, Boxes, Jardinieres, Etc.= By A. A. HOUGHTON. The molds for producing many original designs of flower-pots, urns, flower-boxes, jardinieres, etc., are fully illustrated and explained, so the worker can easily construct and operate same. (No. 10 of Series.) Price =50 cents= =Molding Concrete Fountains and Lawn Ornaments.= By A. A. HOUGHTON. The molding of a number of designs of lawn seats, curbing, hitching posts, pergolas, sun dials and other forms of ornamental concrete for the ornamentation of lawns and gardens, is fully illustrated and described. (No. 11 of Series.) Price =50 cents= =Concrete from Sand Molds.= By A. A. HOUGHTON. A Practical Work treating on a process which has heretofore been held as a trade secret by the few who possessed it, and which will successfully mold every and any class of ornamental concrete work. The process of molding concrete with sand molds is of the utmost practical value, possessing the manifold advantages of a low cost of molds, the ease and rapidity of operation, perfect details to all ornamental designs, density and increased strength of the concrete, perfect curing of the work without attention and the easy removal of the molds regardless of any undercutting the design may have. 192 pages. Fully illustrated Price =$2.00= =Ornamental Concrete without Molds.= By A. A. HOUGHTON. The process for making ornamental concrete without molds has long been held as a secret, and now, for the first time, this process is given to the public. The book reveals the secret and is the only book published which explains a simple, practical method whereby the concrete worker is enabled, by employing wood and metal templates of different designs, to mold or model in concrete any Cornice, Archivolt, Column, Pedestal, Base Cap, Urn or Pier in a monolithic form--right upon the job. These may be molded in units or blocks and then built up to suit the specifications demanded. This work is fully illustrated, with detailed engravings. Price =$2.00= =Concrete for the Farm and in the Shop.= By H. COLIN CAMPBELL, C.E., E.M. "Concrete for the Farm and in the Shop" is a new book from cover to cover, illustrating and describing in plain, simple language many of the numerous applications of concrete within the range of the home worker. Among the subjects treated are: Principles of Reinforcing; Methods of Protecting Concrete so as to Insure Proper Hardening; Home-made Mixers; Mixing by Hand and Machine; Form Construction, Described and Illustrated by Drawings and Photographs; Construction of Concrete Walls and Fences; Concrete Fence Posts; Concrete Gate Posts; Corner Posts; Clothes Line Posts; Grape Arbor Posts; Tanks; Troughs; Cisterns; Hog Wallows; Feeding Floors and Barnyard Pavements; Foundations; Well Curbs and Platforms; Indoor Floors; Sidewalks; Steps; Concrete Hotbeds and Cold Frames; Concrete Slab Roofs; Walls for Buildings; Repairing Leaks in Tanks and Cisterns; and all topics associated with these subjects as bearing upon securing the best results from concrete are dwelt upon at sufficient length in plain every-day English so that the inexperienced person desiring to undertake a piece of concrete construction can, by following the directions set forth in this book, secure 100 per cent. success every time. A number of convenient and practical tables for estimating quantities, and some practical examples, are also given. (5x7.) 149 pages. 51 illustrations. Price =75 cents= =Popular Handbook for Cement and Concrete Users.= By MYRON H. LEWIS. This is a concise treatise of the principles and methods employed in the manufacture and use of cement in all classes of modern works. The author has brought together in this work all the salient matter of interest to the user of concrete and its many diversified products. The matter is presented in logical and systematic order, clearly written, fully illustrated and free from involved mathematics. Everything of value to the concrete user is given, including kinds of cement employed in construction, concrete architecture, inspection and testing, waterproofing, coloring and painting, rules, tables, working and cost data. The book comprises thirty-three chapters, as follow: Introductory. Kinds of Cement and How They are Made. Properties. Testing and Requirements of Hydraulic Cement. Concrete and Its Properties. Sand, Broken Stone and Gravel for Concrete. How to Proportion the Materials. How to Mix and Place Concrete. Forms of Concrete Construction. The Architectural and Artistic Possibilities of Concrete. Concrete Residences. Mortars, Plasters and Stucco, and How to Use Them. The Artistic Treatment of Concrete Surfaces. Concrete Building Blocks. The Making of Ornamental Concrete. Concrete Pipes, Fences, Posts, etc. Essential Features and Advantages of Reenforced Concrete. How to Design Reenforced Concrete Beams, Slabs and Columns. Explanations of the Methods and Principles in Designing Reenforced Concrete, Beams and Slabs. Systems of Reenforcement Employed. Reenforced Concrete in Factory and General Building Construction. Concrete in Foundation Work. Concrete Retaining Walls, Abutments and Bulkheads. Concrete Arches and Arch Bridges. Concrete Beam and Girder Bridges. Concrete in Sewerage and Draining Works. Concrete Tanks, Dams and Reservoirs. Concrete Sidewalks, Curbs and Pavements. Concrete in Railroad Construction. The Utility of Concrete on the Farm. The Waterproofing of Concrete Structures. Grout of Liquid Concrete and Its Use. Inspection of Concrete Work. Cost of Concrete Work. Some of the special features of the book are: 1.--The Attention Paid to the Artistic and Architectural Side of Concrete Work. 2.--The Authoritative Treatment of the Problem of Waterproofing Concrete. 3.--An Excellent Summary of the Rules to be Followed in Concrete Construction. 4.--The Valuable Cost Data and Useful Tables given. A valuable Addition to the Library of Every Cement and Concrete User. Price =$2.50= WHAT IS SAID OF THIS BOOK: "The field of Concrete Construction is well covered and the matter contained is well within the understanding of any person."--_Engineering-Contracting._ "Should be on the bookshelves of every contractor, engineer, and architect in the land."--_National Builder._ =Waterproofing Concrete.= By MYRON H. LEWIS. Modern Methods of Waterproofing Concrete and Other Structures. A condensed statement of the Principles, Rules, and Precautions to be Observed in Waterproofing and Dampproofing Structures and Structural Materials. Paper binding. Illustrated. Price =50 cents= ~DICTIONARIES~ =Aviation Terms, Termes D'Aviation, English-French, French-English.= Compiled by Lieuts. VICTOR W. PAGÉ, A.S., S.C.U.S.R., and PAUL MONTARIOL, of the French Flying Corps, on duty on Signal Corps Aviation School, Mineola, L. I. The lists contained are confined to essentials, and special folding plates are included to show all important airplane parts. The lists are divided in four sections as follows: 1.--Flying Field Terms. 2.--The Airplane. 3.--The Engine. 4.--Tools and Shop Terms. A complete, well illustrated volume intended to facilitate conversation between English-speaking and French aviators. A very valuable book for all who are about to leave for duty overseas. Approved for publication by Major W. G. Kilner, S.C., U.S.C.O. Signal Corps Aviation School, Hazelhurst Field, Mineola, L. I. This book should be in every Aviator's and Mechanic's Kit for ready reference. 128 pages, fully illustrated, with detailed engravings. Price =$1.00= =Standard Electrical Dictionary.= By T. O'CONOR SLOANE. An indispensable work to all interested in electrical science. Suitable alike for the student and professional. A practical handbook of reference containing definitions of about 5,000 distinct words, terms and phrases. The definitions are terse and concise; and include every term used in electrical science. Recently issued. An entirely new edition. Should be in the possession of all who desire to keep abreast with the progress of this branch of science. Complete, concise and convenient. 682 pages, 393 illustrations. Price =$3.00= ~DIES--METAL WORK~ =Dies: Their Construction and Use for the Modern Working of Sheet Metals.= By J. V. WOODWORTH. A most useful book, and one which should be in the hands of all engaged in the press working of metals; treating on the Designing, Constructing, and Use of Tools, Fixtures and Devices, together with the manner in which they should be used in the Power Press, for the cheap and rapid production of the great variety of sheet-metal articles now in use. It is designed as a guide to the production of sheet-metal parts at the minimum of cost with the maximum of output. The hardening and tempering of Press tools and the classes of work which may be produced to the best advantage by the use of dies in the power press are fully treated. Its 515 illustrations show dies, press fixtures and sheet-metal working devices, the descriptions of which are so clear and practical that all metal-working mechanics will be able to understand how to design, construct and use them. Many of the dies and press fixtures treated were either constructed by the author or under his supervision. Others were built by skilful mechanics and are in use in large sheet-metal establishments and machine shops. 6th Revised and Enlarged Edition. Price =$3.00= =Punches, Dies and Tools for Manufacturing in Presses.= By J. V. WOODWORTH. This work is a companion volume to the author's elementary work entitled "Dies: Their Construction and Use." It does not go into the details of die-making to the extent of the author's previous book, but gives a comprehensive review of the field of operations carried on by presses. A large part of the information given has been drawn from the author's personal experience. It might well be termed an Encyclopedia of Die-Making, Punch-Making, Die-Sinking, Sheet-Metal Working, and Making of Special Tools, Sub-presses, Devices and Mechanical Combinations for Punching, Cutting, Bending, Forming, Piercing, Drawing, Compressing and Assembling Sheet-Metal Parts, and also Articles of other Materials in Machine Tools. 2d Edition. Price =$4.00= =Drop Forging, Die-Sinking and Machine-Forming of Steel.= By J. V. WOODWORTH. This is a practical treatise on Modern Shop Practice, Processes, Methods, Machine Tools, and Details treating on the Hot and Cold Machine-Forming of Steel and Iron into Finished Shapes: together with Tools, Dies, and Machinery involved in the manufacture of Duplicate Forgings and Interchangeable Hot and Cold Pressed Parts from Bar and Sheet Metal. This book fills a demand of long standing for information regarding drop-forgings, die-sinking and machine-forming of steel and the shop practice involved, as it actually exists in the modern drop-forging shop. The processes of die-sinking and force-making, which are thoroughly described and illustrated in this admirable work, are rarely to be found explained in such a clear and concise manner as is here set forth. The process of die-sinking relates to the engraving or sinking of the female or lower dies, such as are used for drop-forgings, hot and cold machine-forging, swedging, and the press working of metals. The process of force-making relates to the engraving or raising of the male or upper dies used in producing the lower dies for the press-forming and machine-forging of duplicate parts of metal. In addition to the arts above mentioned the book contains explicit information regarding the drop-forging and hardening plants, designs, conditions, equipment, drop hammers, forging machines, etc., machine forging, hydraulic forging, autogenous welding and shop practice. The book contains eleven chapters, and the information contained in these chapters is just what will prove most valuable to the forged-metal worker. All operations described in the work are thoroughly illustrated by means of perspective half-tones and outline sketches of the machinery employed. 300 detailed illustrations. Price =$2.50= ~DRAWING--SKETCHING PAPER~ =Practical Perspective.= By RICHARDS and COLVIN. Shows just how to make all kinds of mechanical drawings in the only practical perspective isometric. Makes everything plain, so that any mechanic can understand a sketch or drawing in this way. Saves time in the drawing room, and mistakes in the shops. Contains practical examples of various classes of work. 4th Edition. Price =50 cents= =Linear Perspective Self-Taught.= By HERMAN T. C. KRAUS. This work gives the theory and practice of linear perspective, as used in architectural, engineering and mechanical drawings. Persons taking up the study of the subject by themselves will be able, by the use of the instruction given, to readily grasp the subject, and by reasonable practice become good perspective draftsmen. The arrangement of the book is good; the plate is on the left-hand, while the descriptive text follows on the opposite page, so as to be readily referred to. The drawings are on sufficiently large scale to show the work clearly and are plainly figured. There is included a self-explanatory chart which gives all information necessary for the thorough understanding of perspective. This chart alone is worth many times over the price of the book. 2d Revised and Enlarged Edition. Price =$2.50= =Self-Taught Mechanical Drawing and Elementary Machine Design.= By F. L. SYLVESTER, M.E., Draftsman, with additions by ERIK OBERG, associate editor of "Machinery." This is a practical treatise on Mechanical Drawing and Machine Design, comprising the first principles of geometric and mechanical drawing, workshop mathematics, mechanics, strength of materials and the calculations and design of machine details. The author's aim has been to adapt this treatise to the requirements of the practical mechanic and young draftsman and to present the matter in as clear and concise a manner as possible. To meet the demands of this class of students, practically all the important elements of machine design have been dealt with, and in addition algebraic formulas have been explained, and the elements of trigonometry treated in the manner best suited to the needs of the practical man. The book is divided into 20 chapters, and in arranging the material, mechanical drawing, pure and simple, has been taken up first, as a thorough understanding of the principles of representing objects facilitates the further study of mechanical subjects. This is followed by the mathematics necessary for the solution of the problems in machine design which are presented later, and a practical introduction to theoretical mechanics and the strength of materials. The various elements entering into machine design, such as cams, gears, sprocket-wheels, cone pulleys, bolts, screws, couplings, clutches, shafting and fly-wheels, have been treated in such a way as to make possible the use of the work as a text-book for a continuous course of study. It is easily comprehended and assimilated even by students of limited previous training. 330 pages, 215 engravings. Price =$2.00= =A New Sketching Paper.= A new specially ruled paper to enable you to make sketches or drawings in isometric perspective without any figuring or fussing. It is being used for shop details as well as for assembly drawings, as it makes one sketch do the work of three, and no workman can help seeing just what is wanted. Pads of 40 sheets, 6x9 inches. Price =25 cents= Pads of 40 sheets, 9x12 inches. Price =50 cents= 40 sheets, 12x18 inches. Price =$1.00= ~ELECTRICITY~ =Arithmetic of Electricity.= By Prof. T. O'CONOR SLOANE. A practical treatise on electrical calculations of all kinds reduced to a series of rules, all of the simplest forms, and involving only ordinary arithmetic; each rule illustrated by one or more practical problems, with detailed solution of each one. This book is classed among the most useful works published on the science of electricity, covering as it does the mathematics of electricity in a manner that will attract the attention of those who are not familiar with algebraical formulas. 20th Edition. 160 pages. Price =$1.00= =Commutator Construction.= By WM. BAXTER, JR. The business end of any dynamo or motor of the direct current type is the commutator. This book goes into the designing, building, and maintenance of commutators, shows how to locate troubles and how to remedy them; everyone who fusses with dynamos needs this. 4th Edition. Price =25 cents= =Dynamo Building for Amateurs, or How to Construct a Fifty-Watt Dynamo.= By ARTHUR J. WEED, Member of N. Y. Electrical Society. A practical treatise showing in detail the construction of a small dynamo or motor, the entire machine work of which can be done on a small foot lathe. Dimensioned working drawings are given for each piece of machine work, and each operation is clearly described. This machine, when used as a dynamo, has an output of fifty watts; when used as a motor it will drive a small drill press or lathe. It can be used to drive a sewing machine on any and all ordinary work. The book is illustrated with more than sixty original engravings, showing the actual construction of the different parts. Among the contents are chapters on: 1. Fifty-Watt Dynamo. 2. Side Bearing Rods. 3. Field Punching. 4. Bearings. 5. Commutator. 6. Pulley. 7. Brush Holders. 8. Connection Board. 9. Armature Shaft. 10. Armature. 11. Armature Winding. 12. Field Winding. 13. Connecting and starting. Paper. Price =50 Cents= Cloth. Price =$1.00= =Electric Bells.= By M. B. SLEEPER. A complete treatise for the practical worker in Installing, Operating and Testing Bell Circuits, Burglar Alarms, Thermostats, and other apparatus used with Electric Bells. Both the electrician and the experimenter will find in this book new material which is essential in their work. Tools, bells, batteries, unusual circuits, burglar alarms, annunciator systems, thermostats, circuit breakers, time alarms, and other apparatus used in bell circuits are described from the standpoints of their application, construction and repair. The detailed instruction for building the apparatus will appeal to the experimenter particularly. The practical worker will find the chapter on Wiring, Calculation of Wire Sizes and Magnet Winding, Upkeep of Systems, and the Location of Faults, of the greatest value in their work. Among the chapters are: Tools and Materials for Bell Work; How and Why Bell Work; Batteries for Small Installations; Making Bells and Push Buttons; Wiring Bell Systems; Construction of Annunciators and Signals; Burglary Alarms and Auxiliary Apparatus; More Elaborate Bell Systems; Finding Faults and Remedying Them. 124 pages, fully illustrated. Price =50 cents= =Electric Lighting and Heating Pocket Book.= By SYDNEY F. WALKER. This book puts in convenient form useful information regarding the apparatus which is likely to be attached to the mains of an electrical company. Tables of units and equivalents are included and useful electrical laws and formulas are stated. 438 pages, 300 engravings. Bound in leather. Pocket book form. Price =$3.00= =Electric Wiring, Diagrams and Switchboards.= By NEWTON HARRISON, with additions by THOMAS POPPE. A thoroughly practical treatise covering the subject of Electric Wiring in all its branches, deluding explanations and diagrams which are thoroughly explicit and greatly simplify the subject. Practical every-day problems in wiring are presented and the method of obtaining intelligent results clearly shown. Only arithmetic is used. Ohm's law is given a simple explanation with reference to wiring for direct and alternating currents. The fundamental principle of drop of potential in circuits is shown with its various applications. The simple circuit is developed with the position of mains, feeders and branches; their treatment as a part of a wiring plan and their employment in house wiring clearly illustrated. Some simple facts about testing are included in connection with the wiring. Molding and conduit work are given careful consideration; and switchboards are systematically treated, built up and illustrated, showing the purpose they serve, for connection with the circuits, and to shunt and compound wound machines. The simple principles of switchboard construction, the development of the switchboard, the connections of the various instruments, including the lightning arrester, are also plainly set forth. Alternating current wiring is treated, with explanations of the power factor, conditions calling for various sizes of wire, and a simple way of obtaining the sizes for single-phase, two-phase and three-phase circuits. This is the only complete work issued showing and telling you what you should know about direct and alternating current wiring. It is a ready reference. The work is free from advanced technicalities and mathematics, arithmetic being used throughout. It is in every respect a handy, well-written, instructive, comprehensive volume on wiring for the wireman, foreman, contractor, or electrician. 2nd Revised Edition. 303 pages, 130 illustrations. Price =$1.50= =Electric Furnaces and their Industrial Applications.= By J. WRIGHT. This is a book which will prove of interest to many classes of people: the manufacturer who desires to know what product can be manufactured successfully in the electric furnace, the chemist who wishes to post himself on the electro-chemistry, and the student of science who merely looks into the subject from curiosity. New, Revised and Enlarged Edition. 320 pages. Fully illustrated, cloth. Price =$3.00= =Electric Toy Making, Dynamo Building, and Electric Motor Construction.= By Prof. T. O'CONOR SLOANE. This work treats of the making at home of electrical toys, electrical apparatus, motors, dynamos, and instruments in general, and is designed to bring within the reach of young and old the manufacture of genuine and useful electrical appliances. The work is especially designed for amateurs and young folks. Thousands of our young people are daily experimenting, and busily engaged in making electrical toys and apparatus of various kinds. The present work is just what is wanted to give the much needed information in a plain, practical manner, with illustrations to make easy the carrying out of the work. 20th Edition. Price =$1.00= =Practical Electricity.= By Prof. T. O'CONOR SLOANE. This work of 768 pages was previously known as Sloane's Electricians' Hand Book, and is intended for the practical electrician who has to make things go. The entire field of electricity is covered within its pages. Among some of the subjects treated are: The Theory of the Electric Current and Circuit, Electro-Chemistry, Primary Batteries, Storage Batteries, Generation and Utilization of Electric Powers, Alternating Current, Armature Winding, Dynamos and Motors, Motor Generators, Operation of the Central Station Switchboards, Safety Appliances, Distribution of Electric Light and Power, Street Mains, Transformers, Arc and Incandescent Lighting, Electric Measurements, Photometry, Electric Railways, Telephony, Bell-Wiring, Electric-Plating, Electric Heating, Wireless Telegraphy, etc. It contains no useless theory; everything is to the point. It teaches you just what you want to know about electricity. It is the standard work published on the subject. Forty-one chapters, 556 engravings. Price =$2.50= =Electricity Simplified.= By Prof. T. O'CONOR SLOANE. The object of "Electricity Simplified" is to make the subject as plain as possible and to show what the modern conception of electricity is; to show how two plates of different metal, immersed in acid, can send a message around the globe; to explain how a bundle of copper wire rotated by a steam engine can be the agent in lighting our streets; to tell what the volt, ohm and ampere are, and what high and low tension mean; and to answer the questions that perpetually arise in the mind in this age of electricity. 13th Edition. 172 pages. Illustrated. Price =$1.00= =House Wiring.= By THOMAS W. POPPE. This work describes and illustrates the actual installation of Electric Light Wiring, the manner in which the work should be done, and the method of doing it. The book can be conveniently carried in the pocket. It is intended for the Electrician, Helper and Apprentice. It solves all Wiring Problems and contains nothing that conflicts with the rulings of the National Board of Fire Underwriters. It gives just the information essential to the Successful Wiring of a Building. Among the subjects treated are: Locating the Meter. Panel-Boards. Switches. Plug Receptacles. Brackets. Ceiling Fixtures. The Meter Connections. The Feed Wires. The Steel Armored Cable System. The Flexible Steel Conduit System. The Ridig Conduit System. A digest of the National Board of Fire Underwriters' rules relating to metallic wiring systems. Various switching arrangements explained and diagrammed. The easiest method of testing the Three- and Four-way circuits explained. The grounding of all metallic wiring systems and the reason for doing so shown and explained. The insulation of the metal parts of lamp fixtures and the reason for the same described and illustrated. 125 pages. 2nd Edition, revised and enlarged. Fully illustrated. Flexible cloth. Price =50 cents= =How to Become a Successful Electrician.= By Prof. T. O'CONOR SLOANE. Every young man who wishes to become a successful electrician should read this book. It tells in simple language the surest and easiest way to become a successful electrician. The studies to be followed, methods of work, field of operation and the requirements of the successful electrician are pointed out and fully explained. Every young engineer will find this an excellent stepping stone to more advanced works on electricity which he must master before success can be attained. Many young men become discouraged at the very outstart by attempting to read and study books that are far beyond their comprehension. This book serves as the connecting link between the rudiments taught in the public schools and the real study of electricity. It is interesting from cover to cover. 18th Revised Edition, just issued. 205 pages. Illustrated. Price =$1.00= =Management of Dynamos.= By LUMMIS-PATERSON. A handbook of theory and practice. This work is arranged in three parts. The first part covers the elementary theory of the dynamo. The second part, the construction and action of the different classes of dynamos in common use are described; while the third part relates to such matters as affect the practical management and working of dynamos and motors. 4th Edition. 292 pages, 117 illustrations. Price =$1.50= =Standard Electrical Dictionary.= By T. O'CONOR SLOANE. An indispensable work to all interested in electrical science. Suitable alike for the student and professional. A practical handbook of reference containing definitions of about 5,000 distinct words, terms and phrases. The definitions are terse and concise and include every term used in electrical science. Recently issued. An entirely new edition. Should be in the possession of all who desire to keep abreast with the progress of this branch of science. In its arrangement and typography the book is very convenient. The word or term defined is printed in black-faced type, which readily catches the eye, while the body of the page is in smaller but distinct type. The definitions are well worded, and so as to be understood by the non-technical reader. The general plan seems to be to give an exact, concise definition, and then amplify and explain in a more popular way. Synonyms are also given, and references to other words and phrases are made. A very complete and accurate index of fifty pages is at the end of the volume; and as this index contains all synonyms, and as all phrases are indexed in every reasonable combination of words, reference to the proper place in the body of the book is readily made. It is difficult to decide how far a book of this character is to keep the dictionary form, and to what extent it may assume the encyclopedia form. For some purposes, concise, exactly worded definitions are needed; for other purposes, more extended descriptions are required. This book seeks to satisfy both demands, and does it with considerable success. 682 pages, 393 illustrations. 12th Edition. Price =$3.00= =Storage Batteries Simplified.= By VICTOR W. PAGÉ, M.E. A complete treatise on storage battery operating principles, repairs and applications. The greatly increasing application of storage batteries in modern engineering and mechanical work has created a demand for a book that will consider this subject completely and exclusively. This is the most thorough and authoritative treatise ever published on this subject. It is written in easily understandable, non-technical language so that any one may grasp the basic principles of storage battery action as well as their practical industrial applications. All electric and gasoline automobiles use storage batteries. Every automobile repairman, dealer or salesman should have a good knowledge of maintenance and repair of these important elements of the motor car mechanism. This book not only tells how to charge, care for and rebuild storage batteries but also outlines all the industrial uses. Learn how they run street cars, locomotives and factory trucks. Get an understanding of the important functions they perform in submarine boats, isolated lighting plants, railway switch and signal systems, marine applications, etc. This book tells how they are used in central station standby service, for starting automobile motors and in ignition systems. Every practical use of the modern storage battery is outlined in this treatise. 320 pages, fully illustrated. Price =$1.50= =Switchboards.= By WILLIAM BAXTER, JR. This book appeals to every engineer and electrician who wants to know the practical side of things. It takes up all sorts and conditions of dynamos, connections and circuits, and shows by diagram and illustration just how the switchboard should be connected. Includes direct and alternating current boards, also those for arc lighting, incandescent and power circuits. Special treatment on high voltage boards for power transmission. 2nd Edition. 190 pages, Illustrated. Price =$1.50= =Telephone Construction, Installation, Wiring, Operation and Maintenance.= By W. H. RADCLIFFE and H. C. CUSHING. This book is intended for the amateur, the wireman, or the engineer who desires to establish a means of telephonic communication between the rooms of his home, office, or shop. It deals only with such things as may be of use to him rather than with theories. Gives the principles of construction and operation of both the Bell and Independent instruments; approved methods of installing and wiring them; the means of protecting them from lightning and abnormal currents; their connection together for operation as series or bridging stations; and rules for their inspection and maintenance. Line wiring and the wiring and operation of special telephone systems are also treated. Intricate mathematics are avoided, and all apparatus, circuits and systems are thoroughly described. The appendix contains definitions of units and terms used in the text. Selected wiring tables, which are very helpful, are also included. Among the subjects treated are Construction, Operation, and Installation of Telephone Instruments; Inspection and Maintenance of Telephone Instruments; Telephone Line Wiring; Testing Telephone Line Wires and Cables; Wiring and Operation of Special Telephone Systems, etc. 2nd Edition, Revised and Enlarged. 223 pages, 154 illustrations. Price =$1.00= =Wireless Telegraphy and Telephony Simply Explained.= By ALFRED P. MORGAN. This is undoubtedly one of the most complete and comprehensible treatises on the subject ever published, and a close study of its pages will enable one to master all the details of the wireless transmission of messages. The author has filled a long-felt want and has succeeded in furnishing a lucid, comprehensible explanation in simple language of the theory and practice of wireless telegraphy and telephony. Among the contents are: Introductory; Wireless Transmission and Reception--The Aerial System, Earth Connections--The Transmitting Apparatus, Spark Coils and Transformers, Condensers, Helixes, Spark Gaps, Anchor Gaps, Aerial Switches--The Receiving Apparatus, Detectors, etc.--Tuning and Coupling, Tuning Coils, Loose Couplers, Variable Condensers, Directive Wave Systems--Miscellaneous Apparatus, Telephone Receivers, Range of Stations, Static Interference--Wireless Telephones, Sound and Sound Waves, The Vocal Cords and Ear--Wireless Telephone, How Sounds Are Changed into Electric Waves--Wireless Telephones, The Apparatus--Summary. 154 pages, 156 engravings. Price =$1.00= =Wiring a House.= By HERBERT PRATT. Shows a house already built; tells just how to start about wiring it; where to begin; what wire to use; how to run it according to Insurance Rules; in fact, just the information you need. Directions apply equally to a shop. 4th Edition. Price =25 cents= ~FACTORY MANAGEMENT, ETC.~ =Modern Machine Shop Construction, Equipment and Management.= By O. E. PERRIGO, M.E. The only work published that describes the modern machine shop or manufacturing plant from the time the grass is growing on the site intended for it until the finished product is shipped. By a careful study of its thirty-two chapters the practical man may economically build, efficiently equip, and successfully manage the modern machine shop or manufacturing establishment. Just the book needed by those contemplating the erection of modern shop buildings, the rebuilding and reorganization of old ones, or the introduction of modern shop methods, time and cost systems. It is a book written and illustrated by a practical shop man for practical shop men who are too busy to read _theories_ and want _facts_. It is the most complete all-around book of its kind ever published. It is a practical book for practical men, from the apprentice in the shop to the president in the office. It minutely describes and illustrates the most simple and yet the most efficient time and cost system yet devised. 2nd Revised and Enlarged Edition, just issued. 384 pages, 219 illustrations. Price =$5.00= ~FUEL~ =Combustion of Coal and the Prevention of Smoke.= By WM. M. BARR. This book has been prepared with special reference to the generation of heat by the combustion of the common fuels found in the United States, and deals particularly with the conditions necessary to the economic and smokeless combustion of bituminous coals in Stationary and Locomotive Steam Boilers. The presentation of this important subject is systematic and progressive. The arrangement of the book is in a series of practical questions to which are appended accurate answers, which describe in language, free from technicalities, the several processes involved in the furnace combustion of American fuels; it clearly states the essential requisites for perfect combustion, and points out the best methods for furnace construction for obtaining the greatest quantity of heat from any given quality of coal. Nearly 350 pages, fully illustrated. Price =$1.00= =Smoke Prevention and Fuel Economy.= By BOOTH and KERSHAW. A complete treatise for all interested in smoke prevention and combustion, being based on the German work of Ernst Schmatolla, but it is more than a mere translation of the German treatise, much being added. The authors show as briefly as possible the principles of fuel combustion, the methods which have been and are at present in use, as well as the proper scientific methods for obtaining all the energy in the coal and burning it without smoke. Considerable space is also given to the examination of the waste gases, and several of the representative English and American mechanical stoker and similar appliances are described. The losses carried away in the waste gases are thoroughly analyzed and discussed in the Appendix, and abstracts are also here given of various patents on combustion apparatus. The book is complete and contains much of value to all who have charge of large plants. 194 pages. Illustrated. Price =$2.50= ~GAS ENGINES AND GAS~ =Gas, Gasoline and Oil Engines.= By GARDNER D. HISCOX. Revised by VICTOR W. PAGÉ, M.E. Just issued New 1918 Edition, Revised and Enlarged. Every user of a gas engine needs this book. Simple, instructive and right up-to-date. The only complete work on the subject. Tells all about internal combustion engineering, treating exhaustively on the design, construction and practical application of all forms of gas, gasoline, kerosene and crude petroleum-oil engines. Describes minutely all auxiliary systems, such as lubrication, carburetion and ignition. Considers the theory and management of all forms of explosive motors for stationary and marine work, automobiles, aeroplanes and motor-cycles. Includes also Producer Gas and Its Production. Invaluable instructions for all students, gas-engine owners, gas-engineers, patent experts, designers, mechanics, draftsmen and all having to do with the modern power. Illustrated by over 400 engravings, many specially made from engineering drawings, all in correct proportion. 650 pages, 435 engravings. Price =$2.50 net= =The Gasoline Engine on the Farm: Its Operation, Repair and Uses.= By XENO W. PUTNAM. This is a practical treatise on the Gasoline and Kerosene Engine intended for the man who wants to know just how to manage his engine and how to apply it to all kinds of farm work to the best advantage. This book abounds with hints and helps for the farm and suggestions for the home and house-wife. There is so much of value in this book that it is impossible to adequately describe it in such small space. Suffice to say that it is the kind of a book every farmer will appreciate and every farm home ought to have. Includes selecting the most suitable engine for farm work, its most convenient and efficient installation, with chapters on troubles, their remedies, and how to avoid them. The care and management of the farm tractor in plowing, harrowing, harvesting and road grading are fully covered; also plain directions are given for handling the tractor on the road. Special attention is given to relieving farm life of its drudgery by applying power to the disagreeable small tasks which must otherwise be done by hand. Many home made contrivances for cutting wood, supplying kitchen, garden, and barn with water, loading, hauling and unloading hay, delivering grain to the bins or the feed trough are included; also full directions for making the engine milk the cows, churn, wash, sweep the house and clean the windows, etc. Very fully illustrated with drawings of working parts and cuts showing Stationary, Portable and Tractor Engines doing all kinds of farm work. All money-making farms utilize power. Learn how to utilize power by reading the pages of this book. It is an aid to the result getter, invaluable to the up-to-date farmer, student, blacksmith, implement dealer and, in fact, all who can apply practical knowledge of stationary gasoline engines or gas tractors to advantage. 530 pages. Nearly 180 engravings. Price =$2.00= WHAT IS SAID OF THIS BOOK: "Am much pleased with the book and find it to be very complete and up-to-date. I will heartily recommend it to students and farmers whom I think would stand in need of such a work, as I think it is an exceptionally good one."--_N. S. Gardiner_, Prof. in Charge, Clemson Agr. College of S. C.; Dept. of Agri. and Agri. Exp. Station, Clemson College, S. C. "I feel that Mr. Putnam's book covers the main points which a farmer should know."--_R. T. Burdick_, Instructor in Agronomy, University of Vermont, Burlington, Vt. =Gasoline Engines: Their Operation, Use and Care.= By A. HYATT VERRILL. The simplest, latest and most comprehensive popular work published on Gasoline Engines, describing what the Gasoline Engine is; its construction and operation; how to install it; how to select it; how to use it and how to remedy troubles encountered. Intended for Owners, Operators and Users of Gasoline Motors of all kinds. This work fully describes and illustrates the various types of Gasoline Engines used in Motor Boats, Motor Vehicles and Stationary Work. The parts, accessories and appliances are described with chapters on ignition, fuel, lubrication, operation and engine troubles. Special attention is given to the care, operation and repair of motors, with useful hints and suggestions on emergency repairs and makeshifts. A complete glossary of technical terms and an alphabetically arranged table of troubles and their symptoms form most valuable and unique features of this manual. Nearly every illustration in the book is original, having been made by the author. Every page is full of interest and value. A book which you cannot afford to be without. 275 pages, 152 specially made engravings. Price =$1.50= =Gas Engine Construction, or How to Build a Half-horsepower Gas Engine.= By PARSELL and WEED. A practical treatise of 300 pages describing the theory and principles of the action of Gas Engines of various types and the design and construction of a half-horsepower Gas Engine, with illustrations of the work in actual progress, together with the dimensioned working drawings, giving clearly the sizes of the various details; for the student, the scientific investigator, and the amateur mechanic. This book treats of the subject more from the standpoint of practice than that of theory. The principles of operation of Gas Engines are clearly and simply described, and then the actual construction of a half-horsepower engine is taken up, step by step, showing in detail the making of the Gas Engine. 3rd Edition. 300 pages. Price =$2.50= =How to Run and Install Two- and Four-Cycle Marine Gasoline Engines.= By C. VON CULIN. Revised and enlarged edition just issued. The object of this little book is to furnish a pocket instructor for the beginner, the busy man who uses an engine for pleasure or profit, but who does not have the time or inclination for a technical book, but simply to thoroughly understand how to properly operate, install and care for his own engine. The index refers to each trouble, remedy, and subject alphabetically. Being a quick reference to find the cause, remedy and prevention for troubles, and to become an expert with his own engine. Pocket size. Paper binding. Price =25 cents= =Modern Gas Engines and Producer Gas Plants.= By R. E. MATHOT. A guide for the gas engine designer, user, and engineer in the construction, selection, purchase, installation, operation, and maintenance of gas engines. More than one book on gas engines has been written, but not one has thus far even encroached on the field covered by this book. Above all, Mr. Mathot's work is a practical guide. Recognizing the need of a volume that would assist the gas engine user in understanding thoroughly the motor upon which he depends for power, the author has discussed his subject without the help of any mathematics and without elaborate theoretical explanations. Every part of the gas engine is described in detail, tersely, clearly, with a thorough understanding of the requirements of the mechanic. Helpful suggestions as to the purchase of an engine, its installation, care, and operation, form a most valuable feature of the work. 320 pages, 175 detailed illustrations. Price =$2.50= =The Modern Gas Tractor.= By VICTOR W. PAGÉ, M. E. A complete treatise describing all types and sizes of gasoline, kerosene and oil tractors. Considers design and construction exhaustively, gives complete instructions for care, operation and repair, outlines all practical applications on the road and in the field. The best and latest work on farm tractors and tractor power plants. A work needed by farmers, students, blacksmiths, mechanics, salesmen, implement dealers, designers and engineers. 2nd Edition, Revised. 504 pages, 228 illustrations, 3 folding plates. Price =$2.00= ~GEARING AND CAMS~ =Bevel Gear Tables.= By D. AG. ENGSTROM. A book that will at once commend itself to mechanics and draftsmen. Does away with all the trigonometry and fancy figuring on bevel gears, and makes it easy for anyone to lay them out or make them just right. There are 36 full-page tables that show every necessary dimension for all sizes or combinations you're apt to need. No puzzling, figuring or guessing. Gives placing distance, all the angles (including cutting angles), and the correct cutter to use. A copy of this prepares you for anything in the bevel-gear line. 3rd Edition. 66 pages. Price =$1.00= =Change Gear Devices.= By OSCAR E. PERRIGO. A practical book for every designer, draftsman, and mechanic interested in the invention and development of the devices for feed changes on the different machines requiring such mechanism. All the necessary information on this subject is taken up, analyzed, classified, sifted, and concentrated for the use of busy men who have not the time to go through the masses of irrelevant matter with which such a subject is usually encumbered and select such information as will be useful to them. It shows just what has been done, how it has been done, when it was done, and who did it. It saves time in hunting up patent records and re-inventing old ideas. 88 pages. 3rd Edition. Price =$1.00= =Drafting of Cams.= By LOUIS ROUILLION. The laying out of cams is a serious problem unless you know how to go at it right. This puts you on the right road for practically any kind of cam you are likely to run up against. 3rd Edition. Price =25 Cents= ~HYDRAULICS~ =Hydraulic Engineering.= By GARDNER D. HISCOX. A treatise on the properties, power, and resources of water for all purposes. Including the measurement of streams, the flow of water in pipes or conduits; the horsepower of falling water, turbine and impact water-wheels, wave motors, centrifugal, reciprocating and air-lift pumps. With 300 figures and diagrams and 36 practical tables. All who are interested in water-works development will find this book a useful one, because it is an entirely practical treatise upon a subject of present importance and cannot fail in having a far-reaching influence, and for this reason should have a place in the working library of every engineer. Among the subjects treated are: Historical Hydraulics; Properties of Water; Measurement of the Flow of Streams; Flow from Sub-surface Orifices and Nozzles; Flow of Water in Pipes; Siphons of Various Kinds; Dams and Great Storage Reservoirs; City and Town Water Supply; Wells and Their Reinforcement; Air-lift Methods of Raising Water; Artesian Wells; Irrigation of Arid Districts; Water Power; Water Wheels; Pumps and Pumping Machinery; Reciprocating Pumps; Hydraulic Power Transmission; Hydraulic Mining; Canals; Ditches; Conduits and Pipe Lines; Marine Hydraulics; Tidal and Sea Wave Power, etc. 320 pages. Price =$4.00= ~ICE AND REFRIGERATION~ =Pocketbook of Refrigeration and Ice Making.= By A. J. WALLIS-TAYLOR. This is one of the latest and most comprehensive reference books published on the subject of refrigeration and cold storage. It explains the properties and refrigerating effect of the different fluids in use, the management of refrigerating machinery and the construction and insulation of cold rooms with their required pipe surface for different degrees of cold; freezing mixtures and non-freezing brines, temperatures of cold rooms for all kinds of provisions, cold storage charges for all classes of goods, ice making and storage of ice, data and memoranda for constant reference by refrigerating engineers, with nearly one hundred tables containing valuable references to every fact and condition required in the installment and operation of a refrigerating plant. New edition just published. Price =$1.50= ~INVENTIONS--PATENTS~ =Inventors' Manual: How to Make a Patent Pay.= This is a book designed as a guide to inventors in perfecting their inventions, taking out their patents and disposing of them. It is not in any sense a Patent Solicitor's Circular nor a Patent Broker's Advertisement. No advertisements of any description appear in the work. It is a book containing a quarter of a century's experience of a successful inventor, together with notes based upon the experience of many other inventors. Among the subjects treated in this work are: How to Invent. How to Secure a Good Patent. Value of Good Invention. How to Exhibit an Invention. How to Interest Capital. How to Estimate the Value of a Patent. Value of Design Patents. Value of Foreign Patents. Value of Small Inventions. Advice on Selling Patents. Advice on the Formation of Stock Companies. Advice on the Formation of Limited Liability Companies. Advice on Disposing of Old Patents. Advice as to Patent Attorneys. Advice as to Selling Agents. Forms of Assignments. License and Contracts. State Laws Concerning Patent Rights. 1900 Census of the United States by Counts of Over 10,000 Population. Revised Edition. 120 pages. Price =$1.00= ~KNOTS~ =Knots, Splices and Rope Work.= By A. HYATT VERRILL. This is a practical book giving complete and simple directions for making all the most useful and ornamental knots in common use, with chapters on Splicing, Pointing, Seizing, Serving, etc. This book is fully illustrated with 154 original engravings, which show how each knot, tie or splice is formed, and its appearance when finished. The book will be found of the greatest value to Campers, Yachtsmen, Travelers, Boy Scouts, in fact, to anyone having occasion to use or handle rope or knots for any purpose. The book is thoroughly reliable and practical, and is not only a guide, but a teacher. It is the standard work on the subject. Among the contents are: 1. Cordage, Kinds of Rope. Construction of Rope, Parts of Rope Cable and Bolt Rope. Strength of Rope, Weight of Rope. 2. Simple Knots and Bends. Terms Used in Handling Rope. Seizing Rope. 3. Ties and Hitches. 4. Noose, Loops and Mooring Knots. 5. Shortenings, Grommets and Salvages. 6. Lashings, Seizings and Splices. 7. Fancy Knots and Rope Work. 128 pages, 150 original engravings. 2nd Revised Edition. Price =75 cents= ~LATHE WORK~ =Lathe Design, Construction, and Operation, with Practical Examples of Lathe Work.= By OSCAR E. PERRIGO. A new, revised edition, and the only complete American work on the subject, written by a man who knows not only how work ought to be done, but who also knows how to do it, and how to convey this knowledge to others. It is strictly up-to-date in its descriptions and illustrations. Lathe history and the relations of the lathe to manufacturing are given; also a description of the various devices for feeds and thread-cutting mechanisms from early efforts in this direction to the present time. Lathe design is thoroughly discussed, including back gearing, driving cones, thread-cutting gears, and all the essential elements of the modern lathe. The classification of lathes is taken up, giving the essential differences of the several types of lathes including, as is usually understood, engine lathes, bench lathes, speed lathes, forge lathes, gap lathes, pulley lathes, forming lathes, multiple-spindle lathes, rapid-reduction lathes, precision lathes, turret lathes, special lathes, electrically driven lathes, etc. In addition to the complete exposition on construction and design, much practical matter on lathe installation, care and operation has been incorporated in the enlarged new edition. All kinds of lathe attachments for drilling, milling, etc., are described and complete instructions are given to enable the novice machinist to grasp the art of lathe operation as well as the principles involved in design. A number of difficult machining operations are described at length and illustrated. The new edition has nearly 500 pages and 350 illustrations. Price =$2.50= WHAT IS SAID OF THIS BOOK: "This is a lathe book from beginning to end, and is just the kind of a book which one delights to consult--a masterly treatment of the subject in hand."--_Engineering News._ "This work will be of exceptional interest to any one who is interested in lathe practice, as one very seldom sees such a complete treatise on a subject as this is on the lathe."--_Canadian Machinery._ =Practical Metal Turning.= By JOSEPH G. HORNER. A work of 404 pages, fully illustrated, covering in a comprehensive manner the modern practice of machining metal parts in the lathe, including the regular engine lathe, its essential design, its uses, its tools, its attachments, and the manner of holding the work and performing the operations. The modernized engine lathe, its methods, tools and great range of accurate work. The turret lathe, its tools, accessories and methods of performing its functions. Chapters on special work, grinding, tool holders, speeds, feeds, modern tool steels, etc. Second edition =$3.50= =Turning and Boring Tapers.= By FRED H. COLVIN. There are two ways to turn tapers; the right way and one other. This treatise has to do with the right way; it tells you how to start the work properly, how to set the lathe, what tools to use and how to use them, and forty and one other little things that you should know. Fourth edition =25 cents= ~LIQUID AIR~ =Liquid Air and the Liquefaction of Gases.= By T. O'CONOR SLOANE. This book gives the history of the theory, discovery and manufacture of Liquid Air, and contains an illustrated description of all the experiments that have excited the wonder of audiences all over the country. It shows how liquid air, like water, is carried hundreds of miles and is handled in open buckets. It tells what may be expected from it in the near future. A book that renders simple one of the most perplexing chemical problems of the century. Startling developments illustrated by actual experiments. It is not only a work of scientific interest and authority, but is intended for the general reader, being written in a popular style--easily understood by every one. Second edition. 365 pages. Price =$2.00= ~LOCOMOTIVE ENGINEERING~ =Air-Brake Catechism.= By ROBERT H. BLACKALL. This book is a standard text-book. It covers the Westinghouse Air-Brake Equipment, including the No. 5 and the No. 6 E.-T. Locomotive Brake Equipment; the K (Quick Service) Triple Valve for Freight Service; and the Cross-Compound Pump. The operation of all parts of the apparatus is explained in detail, and a practical way of finding their peculiarities and defects, with a proper remedy, is given. It contains 2,000 questions with their answers, which will enable any railroad man to pass any examination on the subject of Air Brakes. Endorsed and used by air-brake instructors and examiners on nearly every railroad in the United States. Twenty-sixth edition. 411 pages, fully illustrated with colored plates and diagrams. Price =$2.00= =American Compound Locomotives.= By FRED H. COLVIN. The only book on compounds for the engineman or shopman that shows in a plain, practical way the various features of compound locomotives in use. Shows how they are made, what to do when they break down or balk. Contains sections as follows: A Bit of History. Theory of Compounding Steam Cylinders. Baldwin Two-Cylinder Compound. Pittsburg Two-Cylinder Compound. Rhode Island Compound. Richmond Compound. Rogers Compound. Schenectady Two-Cylinder Compound. Vauclain Compound. Tandem Compounds. Baldwin Tandem. The Colvin-Wightman Tandem. Schenectady Tandem. Balanced Locomotives. Baldwin Balanced Compound. Plans for Balancing. Locating Blows. Breakdowns. Reducing Valves. Drifting. Valve Motion. Disconnecting. Power of Compound Locomotives. Practical Notes. Fully illustrated and containing ten special "Duotone" inserts on heavy Plate Paper, showing different types of Compounds. 142 pages. Price =$1.00= =Application of Highly Superheated Steam to Locomotives.= By ROBERT GARBE. A practical book which cannot be recommended too highly to those motive-power men who are anxious to maintain the highest efficiency in their locomotives. Contains special chapters on Generation of Highly Superheated Steam; Superheated Steam and the Two-Cylinder Simple Engine; Compounding and Superheating; Designs of Locomotive Superheaters; Constructive Details of Locomotives Using Highly Superheated Steam. Experimental and Working Results. Illustrated with folding plates and tables. Cloth. Price =$2.50= =Combustion of Coal and the Prevention of Smoke.= By WM. M. BARR. This book has been prepared with special reference to the generation of heat by the combustion of the common fuels found in the United States and deals particularly with the conditions necessary to the economic and smokeless combustion of bituminous coal in Stationary and Locomotive Steam Boilers. Presentation of this important subject is systematic and progressive. The arrangement of the book is in a series of practical questions to which are appended accurate answers, which describe in language free from technicalities the several processes involved in the furnace combustion of American fuels; it clearly states the essential requisites for perfect combustion, and points out the best methods of furnace construction for obtaining the greatest quantity of heat from any given quality of coal. Nearly 350 pages, fully illustrated. Price =$1.00= =Diary of a Round-House Foreman.= By T. S. REILLY. This is the greatest book of railroad experiences ever published. Containing a fund of information and suggestions along the line of handling men, organizing, etc., that one cannot afford to miss. 176 pages. Price =$1.00= =Link Motions, Valves and Valve Setting.= By FRED H. COLVIN, Associate Editor of "American Machinist." A handy book for the engineer or machinist that clears up the mysteries of valve setting. Shows the different valve gears in use, how they work, and why. Piston and slide valves of different types are illustrated and explained. A book that every railroad man in the motive-power department ought to have. Contains chapters on Locomotive Link Motion, Valve Movements, Setting Slide Valves, Analysis by Diagrams, Modern Practice, Slip of Block, Slice Valves, Piston Valves, Setting Piston Valves, Joy-Allen Valve Gear, Walschaert Valve Gear, Gooch Valve Gear, Alfree-Hubbell Valve Gear, etc., etc. Fully illustrated. Price =50 cents= =Locomotive Boiler Construction.= By FRANK A. KLEINHANS. The construction of boilers in general is treated and, following this, the locomotive boiler is taken up in the order in which its various parts go through the shop. Shows all types of boilers used; gives details of construction; practical facts, such as life of riveting, punches and dies; work done per day, allowance for bending and flanging sheets and other data. Including the recent Locomotive Boiler Inspection Laws and Examination Questions with their answers for Government Inspectors. Contains chapters on Laying-Out Work; Flanging and Forging; Punching; Shearing; Plate Planing; General Tables; Finishing Parts; Bending; Machinery Parts; Riveting; Boiler Details; Smoke-Box Details; Assembling and Calking; Boiler-Shop Machinery, etc., etc. There isn't a man who has anything to do with boiler work, either new or repair work, who doesn't need this book. The manufacturer, superintendent, foreman and boiler worker--all need it. No matter what the type of boiler, you'll find a mint of information that you wouldn't be without. Over 400 pages, five large folding plates. Price =$3.00= =Locomotive Breakdowns and their Remedies.= By GEO. L. FOWLER. Revised by WM. W. WOOD, Air-Brake Instructor. Just issued. Revised pocket edition. It is out of the question to try and tell you about every subject that is covered in this pocket edition of Locomotive Breakdowns. Just imagine all the common troubles that an engineer may expect to happen some time, and then add all of the unexpected ones, troubles that could occur, but that you have never thought about, and you will find that they are all treated with the very best methods of repair. Walschaert Locomotive Valve Gear Troubles, Electric Headlight Troubles, as well as Questions and Answers on the Air Brake are all included. 312 pages. 8th Revised Edition. Fully illustrated. Price =$1.00= =Locomotive Catechism.= By ROBERT GRIMSHAW. The revised edition of "Locomotive Catechism," by Robert Grimshaw, is a New Book from Cover to Cover. It contains twice as many pages and double the number of illustrations of previous editions. Includes the greatest amount of practical information ever published on the construction and management of modern locomotives. Specially Prepared Chapters on the Walschaert Locomotive Valve Gear, the Air-Brake Equipment and the Electric Headlight are given. It commends itself at once to every Engineer and Fireman, and to all who are going in for examination or promotion. In plain language, with full, complete answers, not only all the questions asked by the examining engineer are given, but those which the young and less experienced would ask the veteran, and which old hands ask as "stickers." It is a veritable Encyclopedia of the Locomotive, is entirely free from mathematics, easily understood and thoroughly up to date. Contains over 4,000 Examination Questions with their Answers. 825 pages, 437 illustrations, and 3 folding plates. 28th Revised Edition. Price =$2.50= =Practical Instructor and Reference Book for Locomotive Firemen and Engineers.= By CHAS. F. LOCKHART. An entirely new book on the Locomotive. It appeals to every railroad man, as it tells him how things are done and the right way to do them. Written by a man who has had years of practical experience in locomotive shops and on the road firing and running. The information given in this book cannot be found in any other similar treatise. Eight hundred and fifty-one questions with their answers are included, which will prove specially helpful to those preparing for examination. Practical information on: The Construction and Operation of Locomotives, Breakdowns and their Remedies, Air Brakes and Valve Gears. Rules and Signals are handled in a thorough manner. As a book of reference it cannot be excelled. The book is divided into six parts, as follows: 1. The Fireman's Duties. 2. General Description of the Locomotive. 3. Breakdowns and their Remedies. 4. Air Brakes. 5. Extracts from Standard Rules. 6. Questions for Examination. The 851 questions have been carefully selected and arranged. These cover the examinations required by the different railroads. 368 pages, 88 illustrations. Price =$1.50= =Prevention of Railroad Accidents, or Safety in Railroading.= By GEORGE BRADSHAW. This book is a heart-to-heart talk with Railroad Employees, dealing with facts, not theories, and showing the men in the ranks, from every-day experience, how accidents occur and how they may be avoided. The book is illustrated with seventy original photographs and drawings showing the safe and unsafe methods of work. No visionary schemes, no ideal pictures. Just Plain Facts and Practical Suggestions are given. Every railroad employee who reads the book is a better and safer man to have in railroad service. It gives just the information which will be the means of preventing many injuries and deaths. All railroad employees should procure a copy, read it, and do their part in preventing accidents. 169 pages. Pocket size. Fully illustrated. Price =50 cents= =Train Rule Examinations Made Easy.= By G. E. COLLINGWOOD. This is the only practical work on train rules in print. Every detail is covered, and puzzling points are explained in simple, comprehensive language, making it a practical treatise for the Train Dispatcher, Engineman, Trainman, and all others who have to do with the movements of trains. Contains complete and reliable information of the Standard Code of Train Rules for single track. Shows Signals in Colors, as used on the different roads. Explains fully the practical application of train orders, giving a clear and definite understanding of all orders which may be used. The meaning and necessity for certain rules are explained in such a manner that the student may know beyond a doubt the rights conferred under any orders he may receive or the action required by certain rules. As nearly all roads require trainmen to pass regular examinations, a complete set of examination questions, with their answers, are included. These will enable the student to pass the required examinations with credit to himself and the road for which he works. 2nd Edition, Revised. 256 pages, fully illustrated, with Train Signals in Colors. Price =$1.25= =The Walschaert and Other Modern Radial Valve Gears for Locomotives.= By WM. W. WOOD. If you would thoroughly understand the Walschaert Valve Gear you should possess a copy of this book, as the author takes the plainest form of a steam engine--a stationary engine in the rough, that will only turn its crank in one direction--and from it builds up, with the reader's help, a modern locomotive equipped with the Walschaert Valve Gear, complete. The points discussed are clearly illustrated: Two large folding plates that show the positions of the valves of both inside or outside admission type, as well as the links and other parts of the gear when the crank is at nine different points in its revolution, are especially valuable in making the movement clear. These employ sliding cardboard models which are contained in a pocket in the cover. The book is divided into five general divisions, as follows: 1. Analysis of the gear. 2. Designing and erecting the gear. 3. Advantages of the gear. 4. Questions and answers relating to the Walschaert Valve Gear. 5. Setting valves with the Walschaert Valve Gear; the three primary types of locomotive valve motion; modern radial valve gears other than the Walschaert; the Hobart All-free Valve and Valve Gear, with questions and answers on breakdowns; the Baker-Pilliod Valve Gear; the Improved Baker-Pilliod Valve Gear, with questions and answers on breakdowns. The questions with full answers given will be especially valuable to firemen and engineers in preparing for an examination for promotion. 245 pages. 3rd Revised Edition. Price =$1.50= =Westinghouse E-T Air-Brake Instruction Pocket Book.= By WM. W. WOOD, Air-Brake Instructor. Here is a book for the railroad man, and the man who aims to be one. It is without doubt the only complete work published on the Westinghouse E-T Locomotive Brake Equipment. Written by an Air-Brake Instructor who knows just what is needed. It covers the subject thoroughly. Everything about the New Westinghouse Engine and Tender Brake Equipment, including the standard No. 5 and the Perfected No. 6 style of brake, is treated in detail. Written in plain English and profusely illustrated with Colored Plates, which enable one to trace the flow of pressures throughout the entire equipment. The best book ever published on the Air Brake. Equally good for the beginner and the advanced engineer. Will pass any one through any examination. It informs and enlightens you on every point. Indispensable to every engineman and trainman. Contains examination questions and answers on the E-T equipment. Covering what the E-T Brake is. How it should be operated. What to do when defective. Not a question can be asked of the engineman up for promotion, on either the No. 5 or the No. 6 E-T equipment, that is not asked and answered in the book. If you want to thoroughly understand the E-T equipment get a copy of this book. It covers every detail. Makes Air-Brake troubles and examinations easy. Price =$1.50= ~MACHINE-SHOP PRACTICE~ =American Tool Making and Interchangeable Manufacturing.= By J. V. WOODWORTH. A "shoppy" book, containing no theorizing, no problematical or experimental devices. There are no badly proportioned and impossible diagrams, no catalogue cuts, but a valuable collection of drawings and descriptions of devices, the rich fruits of the author's own experience. In its 500-odd pages the one subject only, Tool Making, and whatever relates thereto, is dealt with. The work stands without a rival. It is a complete, practical treatise, on the art of American Tool Making and system of interchangeable manufacturing as carried on to-day in the United States. In it are described and illustrated all of the different types and classes of small tools, fixtures, devices, and special appliances which are in general use in all machine-manufacturing and metal-working establishments where economy, capacity, and interchangeability in the production of machined metal parts are imperative. The science of jig making is exhaustively discussed, and particular attention is paid to drill jigs, boring, profiling and milling fixtures and other devices in which the parts to be machined are located and fastened within the contrivances. All of the tools, fixtures, and devices illustrated and described have been or are used for the actual production of work, such as parts of drill presses, lathes, patented machinery, typewriters, electrical apparatus, mechanical appliances, brass goods, composition parts, mould products, sheet-metal articles, drop-forgings, jewelry, watches, medals, coins, etc. 531 pages. Price =$4.00= =HENLEY'S ENCYCLOPEDIA OF PRACTICAL ENGINEERING AND ALLIED TRADES.= EDITED by JOSEPH G. HORNER, A.M.I., M.E. This set of five volumes contains about 2,500 pages with thousands of illustrations, including diagrammatic and sectional drawings with full explanatory details. This work covers the entire practice of Civil and Mechanical Engineering. The best known experts in all branches of engineering have contributed to these volumes. The Cyclopedia is admirably well adapted to the needs of the beginner and the self-taught practical man, as well as the mechanical engineer, designer, draftsman, shop superintendent, foreman, and machinist. The work will be found a means of advancement to any progressive man. It is encyclopedic in scope, thorough and practical in its treatment on technical subjects, simple and clear in its descriptive matter, and without unnecessary technicalities or formulæ. The articles are as brief as may be and yet give a reasonably clear and explicit statement of the subject, and are written by men who have had ample practical experience in the matters of which they write. It tells you all you want to know about engineering and tells it so simply, so clearly, so concisely, that one cannot help but understand. As a work of reference it is without a peer. Complete set of five volumes, price =$25.00= =The Modern Machinist.= By JOHN T. USHER. This is a book, showing by plain description and by profuse engravings made expressly for the work, all that is best, most advanced, and of the highest efficiency in modern machine-shop practice, tools and implements, showing the way by which and through which, as Mr. Maxim says "American machinists have become and are the finest mechanics in the world." Indicating as it does, in every line, the familiarity of the author with every detail of daily experience in the shop, it cannot fail to be of service to any man practically connected with the shaping or finishing of metals. There is nothing experimental or visionary about the book, all devices being in actual use and giving good results. It might be called a compendium of shop methods, showing a variety of special tools and appliances which will give new ideas to many mechanics, from the superintendent down to the man at the bench. It will be found a valuable addition to any machinist's library, and should be consulted whenever a new or difficult job is to be done, whether it is boring, milling, turning, or planing, as they are all treated m a practical manner. Fifth edition. 320 pages. 250 illustrations. Price =$2.50= =THE WHOLE FIELD OF MECHANICAL MOVEMENTS COVERED BY MR. HISCOX'S TWO BOOKS= _We publish two books by Gardner D. Hiscox that will keep you from "inventing" things that have been done before, and suggest ways of doing things that you have not thought of before. Many a man spends time and money pondering over some mechanical problem, only to learn, after he has solved the problem, that the same thing has been accomplished and put in practice by others long before. Time and money spent in an effort to accomplish what has already been accomplished are time and money LOST. The whole field of mechanics, every known mechanical movement, and practically every device are covered by these two books. If the thing you want has been invented, it is illustrated in them. If it hasn't been invented, then you'll find in them the nearest things to what you want, some movements or devices that will apply in your case, perhaps; or which will give you a key from which to work. No book or set of books ever published is of more real value to the Inventor, Draftsman, or practical Mechanic than the two volumes described below._ =Mechanical Movements, Powers, and Devices.= By GARDNER D. HISCOX. This is a collection of 1,890 engravings of different mechanical motions and appliances, accompanied by appropriate text, making it a book of great value to the inventor, the draftsman, and to all readers with mechanical tastes. The book is divided into eighteen sections or chapters, in which the subject-matter is classified under the following heads: Mechanical Powers; Transmission of Power; Measurement of Power; Steam Power; Air Power Appliances; Electric Power and Construction; Navigation and Roads; Gearing; Motion and Devices; Controlling Motion; Horological; Mining; Mill and Factory Appliances; Construction and Devices; Drafting Devices; Miscellaneous Devices, etc. 15th Edition. 400 octavo pages. Price =$3.00= =Mechanical Appliances, Mechanical Movements and Novelties of Construction.= By GARDNER D. HISCOX. This is a supplementary volume to the one upon mechanical movements. Unlike the first volume, which is more elementary in character, this volume contains illustrations and descriptions of many combinations of motions and of mechanical devices and appliances found in different lines of machinery, each device being shown by a line drawing with a description showing its working parts and the method of operation. From the multitude of devices described and illustrated might be mentioned, in passing, such items as conveyors and elevators, Pony brakes, thermometers, various types of boilers, solar engines, oil-fuel burners, condensers, evaporators, Corliss and other valve gears, governors, gas engines, water motors of various descriptions, air ships, motors and dynamos, automobile and motor bicycles, railway lock signals, car couplers, link and gear motions, ball bearings, breech-block mechanism for heavy guns, and a large accumulation of others of equal importance. One thousand specially made engravings. 396 octavo pages. Fourth edition. Price =$3.00= =Machine-Shop Tools and Shop Practice.= By W. H. VANDERVOORT. A work of 555 pages and 673 illustrations, describing in every detail the construction, operation and manipulation of both hand and machine tools. Includes chapters on filing, fitting and scraping surfaces; on drills, reamers, taps and dies; the lathe and its tools: planers, shapers, and their tools; milling machines and cutters; gear cutters and gear cutting; drilling machines and drill work; grinding machines and their work; hardening and tempering; gearing, belting and transmission machinery; useful data and tables. Sixth edition. Price =$3.00= =Machine-Shop Arithmetic.= By COLVIN-CHENEY. This is an arithmetic of the things you have to do with daily. It tells you plainly about: how to find areas in figures; how to find surface or volume of balls or spheres; handy ways for calculating; about compound gearing; cutting screw threads on any lathe; drilling for taps; speeds of drills; taps, emery wheels, grindstones, milling cutters, etc.; all about the Metric system with conversion tables; properties of metals; strength of bolts and nuts; decimal equivalent of an inch. All sorts of machine-shop figuring and 1,001 other things, any one of which ought to be worth more than the price of this book to you, as it saves you the trouble of bothering the boss. 6th Edition. 131 pages. Price =50 cents= =Modern Machine-Shop Construction, Equipment and Management.= By OSCAR E. PERRIGO. The only work published that describes the Modern Shop or Manufacturing Plant from the time the grass is growing on the site intended for it until the finished product is shipped. Just the book needed by those contemplating the erection of modern shop buildings, the rebuilding and reorganization of old ones, or the introduction of Modern Shop Methods, time and cost systems. It is a book written and illustrated by a practical shop man for practical shop men who are too busy to read theories and want facts. It is the most complete all-round book of its kind ever published. Second Edition, Revised. 384 large quarto pages. 219 original and specially made illustrations. 2nd Revised and Enlarged Edition. Price =$5.00= =Modern Milling Machines: Their Design, Construction, and Operation.= By JOSEPH G. HORNER. This book describes and illustrates the Milling Machine and its work in such a plain, clear and forceful manner, and illustrates the subject so clearly and completely, that the up-to-date machinist, student or mechanical engineer cannot afford to do without the valuable information which it contains. It describes not only the early machines of this class, but notes their gradual development into the splendid machines of the present day, giving the design and construction of the various types, forms, and special features produced by prominent manufacturers, American and foreign. 304 pages, 300 illustrations. Cloth. Price =$4.00= ="Shop Kinks."= By ROBERT GRIMSHAW. A book of 400 pages and 222 illustrations, being entirely different from any other book on machine-shop practice. Departing from conventional style, the author avoids universal or common shop usage and limits his work to showing special ways of doing things better, more cheaply and more rapidly than usual. As a result the advanced methods of representative establishments of the world are placed at the disposal of the reader. This book shows the proprietor where large savings are possible, and how products may be improved. To the employee it holds out suggestions that, properly applied, will hasten his advancement. No shop can afford to be without it. It bristles with valuable wrinkles and helpful suggestions. It will benefit all, from apprentice to proprietor. Every machinist, at any age, should study its pages. Fifth edition. Price =$2.50= =Threads and Thread Cutting.= By COLVIN and STABEL. This clears up many of the mysteries of thread-cutting, such as double and triple threads, internal threads, catching threads, use of hobs, etc. Contains a lot of useful hints and several tables. Third edition. Price =25 cents= ~MANUAL TRAINING~ =Economics of Manual Training.= By LOUIS ROUILLION. The only book published that gives just the information needed by all interested in Manual Training, regarding Buildings, Equipment, and Supplies. Shows exactly what is needed for all grades of the work from the Kindergarten to the High and Normal School. Gives itemized lists of everything used in Manual Training Work and tells just what it ought to cost. Also shows where to buy supplies, etc. Contains 174 pages, and is fully illustrated. Second edition. Price =$1.50= ~MARINE ENGINEERING~ =The Naval Architect's and Shipbuilder's Pocket Book of Formulæ, Rules, and Tables and Marine Engineer's and Surveyor's Handy Book of Reference.= By CLEMENT MACKROW and LLOYD WOOLLARD. The eleventh Revised and Enlarged Edition of this most comprehensive work has just been issued. It is absolutely indispensable to all engaged in the Shipbuilding Industry, as it condenses into a compact form all data and formulæ that are ordinarily required. The book is completely up to date, including among other subjects a section on Aeronautics. 750 pages, limp leather binding. Price =$5.00 net= =Marine Engines and Boilers: Their Design and Construction.= By DR. G. BAUER, LESLIE S. ROBERTSON and S. BRYAN DONKIN. In the words of Dr. Bauer, the present work owes its origin to an oft felt want of a condensed treatise embodying the theoretical and practical rules used in designing marine engines and boilers. The need of such a work has been felt by most engineers engaged in the construction and working of marine engines, not only by the younger men, but also by those of greater experience. The fact that the original German work was written by the chief engineer of the famous Vulcan Works, Stettin, is in itself a guarantee that this book is in all respects thoroughly up-to-date, and that it embodies all the information which is necessary for the design and construction of the highest types of marine engines and boilers. It may be said that the motive power which Dr. Bauer has placed in the fast German liners that have been turned out of late years from the Stettin Works represent the very best practice in marine engineering of the present day. The work is clearly written, thoroughly systematic, theoretically sound; while the character of the plans, drawings, tables, and statistics is without reproach. The illustrations are careful reproductions from actual working drawings, with some well-executed photographic views of completed engines and boilers. 744 pages, 550 illustrations and numerous tables. Cloth. Price =$9.00 net= ~MINING~ =Ore Deposits, with a Chapter on Hints to Prospectors.= By J. P. JOHNSON. This book gives a condensed account of the ore deposits at present known in South Africa. It is also intended as a guide to the prospector. Only an elementary knowledge of geology and some mining experience are necessary in order to understand this work. With these qualifications, it will materially assist one in his search for metalliferous mineral occurrences and, so far as simple ores are concerned, should enable one to form some idea of the possibilities of any he may find. Illustrated. Cloth. Price =$2.00= =Practical Coal Mining.= By T. H. COCKIN. An important work, containing 428 pages and 213 illustrations, complete with practical details, which will intuitively impart to the reader not only a general knowledge of the principles of coal mining, but also considerable insight into allied subjects. The treatise is positively up-to-date in every instance, and should be in the hands of every colliery engineer, geologist, mine operator, superintendent, foreman, and all others who are interested in or connected with the industry. 3d Edition. Cloth. Price =$2.50= =Physics and Chemistry of Mining.= By T. H. BYROM. A practical work for the use of all preparing for examinations in mining or qualifying for colliery managers' certificates. The aim of the author in this excellent book is to place clearly before the reader useful and authoritative data which will render him valuable assistance in his studies. The only work of its kind published. The information incorporated in it will prove of the greatest practical utility to students, mining engineers, colliery managers, and all others who are specially interested in the present-day treatment of mining problems. 160 pages, illustrated. Price =$2.00= ~PATTERN MAKING~ =Practical Pattern Making.= By F. W. BARROWS. This book, now in its second edition, is a comprehensive and entirely practical treatise on the subject of pattern making, illustrating pattern work in both wood and metal, and with definite instructions on the use of plaster of paris in the trade. It gives specific and detailed descriptions of the materials used by pattern makers, and describes the tools, both those for the bench and the more interesting machine tools, having complete chapters on the Lathe, the Circular Saw, and the Band Saw. It gives many examples of pattern work, each one fully illustrated and explained with much detail. These examples, in their great variety, offer much that will be found of interest to all pattern makers, and especially to the younger ones, who are seeking information on the more advanced branches of their trade. In this second edition of the work will be found much that is new, even to those who have long practised this exacting trade. In the description of patterns as adapted to the Moulding Machine many difficulties which have long prevented the rapid and economical production of castings are overcome; and this great, new branch of the trade is given much space. Stripping plate and stool plate work and the less expensive vibrator, or rapping plate work, are all explained in detail. Plain, every-day rules for lessening the cost of patterns, with a complete system of cost keeping, a detailed method of marking, applicable to all branches of the trade, with complete information showing what the pattern is, its specific title, its cost, date of production, material of which it is made, the number of pieces and core-boxes, and its location in the pattern safe, all condensed into a most complete card record, with cross index. The book closes with an original and practical method for the inventory and valuation of patterns. Containing nearly 350 pages and 170 illustrations. Price =$2.00= ~PERFUMERY~ =Perfumes and Cosmetics: Their Preparation and Manufacture.= By G. W. ASKINSON, Perfumer. A comprehensive treatise, in which there has been nothing omitted that could be of value to the perfumer or manufacturer of toilet preparations. Complete directions for making handkerchief perfumes, smelling-salts, sachets, fumigating pastilles; preparations for the care of the skin, the mouth, the hair, cosmetics, hair dyes and other toilet articles are given, also a detailed description of aromatic substances; their nature, tests of purity, and wholesome manufacture, including a chapter on synthetic products, with formulas for their use. A book of general as well as professional interest, meeting the wants not only of the druggist and perfume manufacturer, but also of the general public. Among the contents are: 1. The History of Perfumery. 2. About Aromatic Substances in General. 3. Odors from the Vegetable Kingdom. 4. The Aromatic Vegetable Substances Employed in Perfumery. 5. The Animal Substances Used in Perfumery. 6. The Chemical Products Used in Perfumery. 7. The Extraction of Odors. 8. The Special Characteristics of Aromatic Substances. 9 The Adulteration of Essential Oils and Their Recognition. 10. Synthetic Products. 11. Table of Physical Properties of Aromatic Chemicals. 12. The Essences or Extracts Employed in Perfumery. 13. Directions for Making the Most Important Essences and Extracts. 14. The Division of Perfumery. 15. The Manufacture of Handkerchief Perfumes. 16. Formulas for Handkerchief Perfumes. 17. Ammoniacal and Acid Perfumes. 18. Dry Perfumes. 19. Formulas for Dry Perfumes. 20. The Perfumes Used for Fumigation. 21. Antiseptic and Therapeutic Value of Perfumes. 22. Classification of Odors. 23. Some Special Perfumery Products. 24. Hygiene and Cosmetic Perfumery. 25. Preparations for the Care of the Skin. 26. Manufacture of Casein. 27. Formulas for Emulsions. 28. Formulas for Cream. 29. Formulas for Meals, Pastes and Vegetable Milk. 30. Preparations Used for the Hair. 31. Formulas for Hair Tonics and Restorers. 32. Pomades and Hair Oils 33. Formulas for the Manufacture of Pomades and Hair Oils. 34. Hair Dyes and Depilatories. 35. Wax Pomades, Bandolines and Brilliantines. 36. Skin Cosmetics and Face Lotions. 37. Preparations for the Nails. 38. Water Softeners and Bath Salts. 39. Preparations for the Care of the Mouth. 40. The Colors Used in Perfumery. 41. The Utensils Used in the Toilet. Fourth edition, much enlarged and brought up to date. Nearly 400 pages, illustrated. Price =$5.00= WHAT IS SAID OF THIS BOOK: "The most satisfactory work on the subject of Perfumery that we have ever seen." "We feel safe in saying that here is a book on Perfumery that will not disappoint you, for it has practical and excellent formulæ that are within your ability to prepare readily." "We recommend the volume as worthy of confidence, and say that no purchaser will be disappointed in securing from its pages good value for its cost, and a large dividend on the same, even if he should use but one per cent. of its working formulæ. There is money in it for every user of its information."--_Pharmaceutical Record._ ~PLUMBING~ =Mechanical Drawing for Plumbers.= By R. M. STARBUCK. A concise, comprehensive and practical treatise on the subject of mechanical drawing in its various modern applications to the work of all who are in any way connected with the plumbing trade. Nothing will so help the plumber in estimating and in explaining work to customers and workmen as a knowledge of drawing, and to the workman it is of inestimable value if he is to rise above his position to positions of greater responsibility. Among the chapters contained are: 1. Value to plumber of knowledge of drawing; tools required and their use; common views needed in mechanical drawing. 2. Perspective versus mechanical drawing in showing plumbing construction. 3. Correct and incorrect methods in plumbing drawing; plan and elevation explained. 4. Floor and cellar plans and elevation; scale drawings; use of triangles. 5. Use of triangles; drawing of fittings, traps, etc. 6. Drawing plumbing elevations and fittings. 7. Instructions in drawing plumbing elevations. 8. The drawing of plumbing fixtures; scale drawings. 9. Drawings of fixtures and fittings. 10. Inking of drawings. 11. Shading of drawings. 12. Shading of drawings. 13. Sectional drawings; drawing of threads. 14. Plumbing elevations from architect's plan. 15. Elevations of separate parts of the plumbing system. 16. Elevations from the architect's plans. 17. Drawings of detail plumbing connections. 18. Architect's plans and plumbing elevations of residence. 19. Plumbing elevations of residence (_continued_); plumbing plans for cottage. 20. Plumbing elevations; roof connections. 21. Plans and plumbing elevations for six-flat building. 22. Drawing of various parts of the plumbing system; use of scales. 23. Use of architect's scales. 24. Special features in the illustrations of country plumbing. 25. Drawing of wrought-iron piping, valves, radiators, coils, etc. 26. Drawing of piping to illustrate heating systems. 150 illustrations. Price =$1.50= =Modern Plumbing Illustrated.= By R. M. STARBUCK. This book represents the highest standard of plumbing work. It has been adopted and used as a reference book by the United States Government in its sanitary work in Cuba, Porto Rico and the Philippines, and by the principal Boards of Health of the United States and Canada. It gives connections, sizes and working data for all fixtures and groups of fixtures. It is helpful to the master plumber in demonstrating to his customers and in figuring work. It gives the mechanic and student quick and easy access to the best modern plumbing practice. Suggestions for estimating plumbing construction are contained in its pages. This book represents, in a word, the latest and best up-to-date practice and should be in the hands of every architect, sanitary engineer and plumber who wishes to keep himself up to the minute on this important feature of construction. Contains following chapters, each illustrated with a full-page plate: Kitchen sink, laundry tubs, vegetable wash sink; lavatories, pantry sinks, contents of marble slabs; bath tub, foot and sitz bath, shower bath; water closets, venting of water closets; low-down water closets, water closets operated by flush valves, water closet range; slop sink, urinals, the bidet; hotel and restaurant sink, grease trap; refrigerators, safe wastes, laundry waste, lines of refrigerators, bar sinks, soda fountain sinks; horse stall, frost-proof water closets; connections for S traps, venting; connections for drum traps; soil-pipe connections; supporting of soil pipe; main trap and fresh-air inlet: floor drains and cellar drains, subsoil drainage; water closets and floor connections; local venting; connections for bath rooms; connections for bath rooms, _continued_; examples of poor practice; roughing work ready for test; testing of plumbing systems; method of continuous venting; continuous venting for two-floor work; continuous venting for two lines of fixtures on three or more floors; continuous venting of water closets; plumbing for cottage house; construction for cellar piping; plumbing for residence, use of special fittings; plumbing for two-flat house: plumbing for apartment building, plumbing for double apartment building; plumbing for office building; plumbing for public toilet rooms; plumbing for public toilet rooms, _continued_; plumbing for bath establishment; plumbing for engine house, factory plumbing, automatic flushing for schools, factories, etc.; use of flushing valves; urinals for public toilet rooms; the Durham system, the destruction of pipes by electrolysis; construction of work without use of lead; automatic sewage lift; automatic sump tank; country plumbing; construction of cesspools; septic tank and automatic sewage siphon; water supply for country house; thawing of water mains and service by electricity; double boilers; hot water supply of large buildings; automatic control of hot-water tank; suggestions for estimating plumbing construction. 407 octavo pages, fully illustrated by 57 full-page engravings. Third, revised and enlarged edition, just issued. Price =$4.00= =Standard Practical Plumbing.= By R. M. STARBUCK. A complete practical treatise of 450 pages, covering the subject of Modern Plumbing in all its branches, a large amount of space being devoted to a very complete and practical treatment of the subject of Hot Water Supply and Circulation and Range Boiler Work. Its thirty chapters include about every phase of the subject one can think of, making it an indispensable work to the master plumber, the journeyman plumber, and the apprentice plumber, containing chapters on: the plumber's tools; wiping solder; composition and use; joint wiping; lead work; traps; siphonage of traps; venting; continuous venting; house sewer and sewer connections; house drain; soil piping, roughing; main trap and fresh air inlet; floor, yard, cellar drains, rain leaders, etc.; fixture wastes; water closets; ventilation; improved plumbing connections; residence plumbing; plumbing for hotels, schools, factories, stables, etc.; modern country plumbing; filtration of sewage and water supply; hot and cold supply; range boilers; circulation; circulating pipes; range boiler problems; hot water for large buildings; water lift and its use; multiple connections for hot water boilers; heating of radiation by supply system; theory for the plumber; drawing for the plumber. Fully illustrated by 347 engravings. Price =$3.00= ~RECIPE BOOK~ =Henley's Twentieth Century Book of Recipes, Formulas and Processes.= Edited by GARDNER D. HISCOX. The most valuable Techno-chemical Formula Book published, including over 10,000 selected scientific, chemical, technological, and practical recipes and processes. This is the most complete Book of Formulas ever published, giving thousands of recipes for the manufacture of valuable articles for everyday use. Hints, Helps, Practical Ideas, and Secret Processes are revealed within its pages. It covers every branch of the useful arts and tells thousands of ways of making money, and is just the book everyone should have at his command. Modern in its treatment of every subject that properly falls within its scope, the book may truthfully be said to present the very latest formulas to be found in the arts and industries, and to retain those processes which long experience has proven worthy of a permanent record. To present here even a limited number of the subjects which find a place in this valuable work would be difficult. Suffice to say that in its pages will be found matter of intense interest and immeasurably practical value to the scientific amateur and to him who wishes to obtain a knowledge of the many processes used in the arts, trades and manufacture, a knowledge which will render his pursuits more instructive and remunerative. Serving as a reference book to the small and large manufacturer and supplying intelligent seekers with the information necessary to conduct a process, the work will be found of inestimable worth to the Metallurgist, the Photographer, the Perfumer, the Painter, the Manufacturer of Glues, Pastes, Cements, and Mucilages, the Compounder of Alloys, the Cook, the Physician, the Druggist, the Electrician, the Brewer, the Engineer, the Foundryman, the Machinist, the Potter, the Tanner, the Confectioner, the Chiropodist, the Manicurist, the Manufacturer of Chemical Novelties and Toilet Preparations, the Dyer, the Electroplater, the Enameler, the Hat Maker, the Ink Manufacturer, the Optician, the Farmer, the Dairyman, the Paper Maker, the Wood and Metal Worker, the Chandler and Soap Maker, the Veterinary Surgeon, and the Technologist in general. A mine of information, and up-to-date in every respect. A book which will prove of value to EVERYONE, as it covers every branch of the Useful Arts. Every home needs this book; every office, every factory, every store, every public and private enterprise--EVERYWHERE--should have a copy. 800 pages. Price =$3.00= WHAT IS SAID OF THIS BOOK: "Your Twentieth Century Book of Recipes, Formulas, and Processes duly received. I am glad to have a copy of it, and if I could not replace it, money couldn't buy it. It is the best thing of the sort I ever saw." (Signed) M. E. TRUX, Sparta, Wis. "There are few persons who would not be able to find in the book some single formula that would repay several times the cost of the book."--_Merchants' Record and Show Window._ "I purchased your book, 'Henley's Twentieth Century Book of Recipes, Formulas and Processes,' about a year ago and it is worth its weight in _gold_."--WM. H. MURRAY, Bennington, Vt. "ONE OF THE WORLD'S MOST USEFUL BOOKS" "Some time ago I got one of your 'Twentieth Century Books of Formulas,' and have made my living from it ever since. I am alone since my husband's death with two small children to care for and am trying so hard to support them. I have customers who take from me Toilet Articles I put up, following directions given in the book, and I have found everyone of them to be fine."--MRS. J. H. MCMAKEN, West Toledo, Ohio. ~RUBBER~ =Rubber Hand Stamps and the Manipulation of India Rubber.= BY T. O'CONOR SLOANE. This book gives full details on all points, treating in a concise and simple manner the elements of nearly everything it is necessary to understand for a commencement in any branch of the India Rubber Manufacture. The making of all kinds of Rubber Hand Stamps, Small Articles of India Rubber, U. S. Government Composition, Dating Hand Stamps, the Manipulation of Sheet Rubber, Toy Balloons, India Rubber Solutions, Cements, Blackings, Renovating, Varnish, and Treatment for India Rubber Shoes, etc.; the Hektograph Stamp Inks, and Miscellaneous Notes, with a Short Account of the Discovery, Collection and Manufacture of India Rubber, are set forth in a manner designed to be readily understood, the explanations being plain and simple. Including a chapter on Rubber Tire Making and Vulcanizing; also a chapter on the uses of rubber in Surgery and Dentistry. 3rd Revised and Enlarged Edition. 175 pages. Illustrated =$1.00= ~SAWS~ =Saw Filing and Management of Saws.= By ROBERT GRIMSHAW. A practical hand-book on filing, gumming, swaging, hammering, and the brazing of band saws, the speed, work, and power to run circular saws, etc. A handy book for those who have charge of saws, or for those mechanics who do their own filing, as it deals with the proper shape and pitches of saw teeth of all kinds and gives many useful hints and rules for gumming, setting, and filing, and is a practical aid to those who use saws for any purpose. Complete tables of proper shape, pitch, and saw teeth as well as sizes and number of teeth of various saws are included. 3rd Edition, Revised and Enlarged. Illustrated. Price =$1.00= ~STEAM ENGINEERING~ =American Stationary Engineering.= By W. E. CRANE. This book begins at the boiler room and takes in the whole power plant. A plain talk on every-day work about engines, boilers, and their accessories. It is not intended to be scientific or mathematical. All formulas are in simple form so that any one understanding plain arithmetic can readily understand any of them. The author has made this the most practical book in print; has given the results of his years of experience, and has included about all that has to do with an engine room or a power plant. You are not left to guess at a single point. You are shown clearly what to expect under the various conditions; how to secure the best results; ways of preventing "shut downs" and repairs; in short, all that goes to make up the requirements of a good engineer, capable of taking charge of a plant. It's plain enough for practical men and yet of value to those high in the profession. A partial list of contents is: The boiler room, cleaning boilers, firing, feeding; pumps, inspection and repair; chimneys, sizes and cost; piping; mason work; foundations; testing cement; pile driving; engines, slow and high speed; valves; valve setting; Corliss engines, setting valves, single and double eccentric; air pumps and condensers; different types of condensers; water needed; lining up; pounds; pins not square in crosshead or crank; engineers' tools; pistons and piston rings; bearing metal; hardened copper; drip pipes from cylinder jacket; belts, how made, care of; oils; greases; testing lubricants; rules and tables, including steam tables; areas of segments; squares and square roots; cubes and cube root; areas and circumferences of circles. Notes on: Brick work; explosions; pumps; pump valves; heaters, economizers; safety valves; lap, lead, and clearance. Has a complete examination for a license, etc., etc. 3rd Edition. 345 pages, illustrated. Price =$2.00= =Engine Runner's Catechism.= By ROBERT GRIMSHAW. A practical treatise for the stationary engineer, telling how to erect, adjust, and run the principal steam engines in use in the United States. Describing the principal features of various special and well-known makes of engines: Temper Cut-off, Shipping and Receiving Foundations, Erecting and Starting, Valve Setting, Care and Use, Emergencies, Erecting and Adjusting Special Engines. The questions asked throughout the catechism are plain and to the point, and the answers are given in such simple language as to be readily understood by anyone. All the instructions given are complete and up-to-date; and they are written in a popular style, without any technicalities or mathematical formulæ. The work is of a handy size for the pocket, clearly and well printed, nicely bound, and profusely illustrated. To young engineers this catechism will be of great value, especially to those who may be preparing to go forward to be examined for certificates of competency; and to engineers generally it will be of no little service, as they will find in this volume more really practical and useful information than is to be found anywhere else within a like compass. 387 pages. 7th Edition. Price =$2.00= =Modern Steam Engineering in Theory and Practice.= By GARDNER D. HISCOX. This is a complete and practical work issued for Stationary Engineers and Firemen, dealing with the care and management of boilers, engines, pumps, superheated steam, refrigerating machinery, dynamos, motors, elevators, air compressors, and all other branches with which the modern engineer must be familiar. Nearly 200 questions with their answers on steam and electrical engineering, likely to be asked by the Examining Board, are included. Among the chapters are: Historical: steam and its properties; appliances for the generation of steam; types of boilers; chimney and its work; heat economy of the feed water; steam pumps and their work; incrustation and its work; steam above atmospheric pressure; flow of steam from nozzles; superheated steam and its work; adiabatic expansion of steam; indicator and its work; steam engine proportions; slide valve engines and valve motion; Corliss engine and its valve gear; compound engine and its theory; triple and multiple expansion engine; steam turbine; refrigeration; elevators and their management; cost of power; steam engine troubles; electric power and electric plants. 487 pages, 405 engravings. 3rd Edition. Price =$3.00= =Steam Engine Catechism.= By ROBERT GRIMSHAW. This unique volume of 413 pages is not only a catechism on the question and answer principle but it contains formulas and worked-out answers for all the Steam problems that appertain to operation and management of the Steam Engine. Illustrations of various valves and valve gear with their principles of operation are given. Thirty-four Tables that are indispensable to every engineer and fireman that wishes to be progressive and is ambitious to become master of his calling are within its pages. It is a most valuable instructor in the service of Steam Engineering. Leading engineers have recommended it as a valuable educator for the beginner as well as a reference book for the engineer. It is thoroughly indexed for every detail. Every essential question on the Steam Engine with its answer is contained in this valuable work. 16th Edition. Price =$2.00= =Steam Engineer's Arithmetic.= By COLVIN-CHENEY. A practical pocket-book for the steam engineer. Shows how to work the problems of the engine room and shows "why." Tells how to figure horsepower of engines and boilers; area of boilers; has tables of areas and circumferences; steam tables; has a dictionary of engineering terms. Puts you on to all of the little kinks in figuring whatever there is to figure around a power plant. Tells you about the heat unit; absolute zero; adiabatic expansion; duty of engines; factor of safety; and a thousand and one other things; and everything is plain and simple--not the hardest way to figure, but the easiest. 2nd Edition. Price =50 Cents= =Engine Tests and Boiler Efficiencies.= By J. BUCHETTI. This work fully describes and illustrates the method of testing the power of steam engines, turbines and explosive motors. The properties of steam and the evaporative power of fuels. Combustion of fuel and chimney draft; with formulas explained or practically computed. 255 pages, 179 illustrations. Price =$3.00= =Horsepower Chart.= Shows the horsepower of any stationary engine without calculation. No matter what the cylinder diameter of stroke, the steam pressure of cut-off, the revolutions, or whether condensing or non-condensing, it's all there. Easy to use. accurate, and saves time and calculations. Especially useful to engineers and designers. Price =50 Cents= ~STEAM HEATING AND VENTILATION~ =Practical Steam, Hot-Water Heating and Ventilation.= By A. G. KING. This book is the standard and latest work published on the subject and has been prepared for the use of all engaged in the business of steam, hot-water heating, and ventilation. It is an original and exhaustive work. Tells how to get heating contracts, how to install heating and ventilating apparatus, the best business methods to be used, with "Tricks of the Trade" for shop use. Rules and data for estimating radiation and cost and such tables and information as make it an indispensable work for everyone interested in steam, hot-water heating, and ventilation. It describes all the principal systems of steam, hot-water, vacuum, vapor, and vacuum-vapor heating, together with the new accelerated systems of hot-water circulation, including chapters on up-to-date methods of ventilation and the fan or blower system of heating and ventilation. Containing chapters on: I. Introduction. II. Heat. III. Evolution of artificial heating apparatus. IV. Boiler surface and settings. V. The chimney flue. VI. Pipe and fittings. VII. Valves, various kinds. VIII. Forms of radiating surfaces. IX. Locating of radiating surfaces. X. Estimating radiation. XI. Steam-heating apparatus XII. Exhaust-steam heating. XIII. Hot-water heating. XIV. Pressure systems of hot-water work. XV. Hot-water appliances. XVI. Greenhouse heating. XVII. Vacuum vapor and vacuum exhaust heating. XVIII. Miscellaneous heating. XIX. Radiator and pipe connections. XX. Ventilation. XXI. Mechanical ventilation and hot-blast heating. XXII. Steam appliances. XXIII. District heating. XXIV. Pipe and boiler covering. XXV. Temperature regulation and heat control. XXVI. Business methods. XXVII. Miscellaneous. XXVIII. Rules, tables, and useful information. 367 pages, 300 detailed engravings. 2nd Edition--Revised. Price =$3.00= =Five Hundred Plain Answers to Direct Questions on Steam, Hot-Water, Vapor and Vacuum Heating Practice.= By ALFRED G. KING. This work, just off the press, is arranged in question and answer form; it is intended as a guide and text-book for the younger, inexperienced fitter and as a reference book for all fitters. This book tells "how" and also tells "why". No work of its kind has ever been published. It answers all the questions regarding each method or system that would be asked by the steam fitter or heating contractor, and may be used as a text or reference book, and for examination questions by Trade Schools or Steam Fitters' Associations. Rules, data, tables and descriptive methods are given, together with much other detailed information of daily practical use to those engaged in or interested in the various methods of heating. Valuable to those preparing for examinations. Answers every question asked relating to modern Steam, Hot-Water, Vapor and Vacuum Heating. Among the contents are: The Theory and Laws of Heat. Methods of Heating. Chimneys and Flues. Boilers for Heating. Boiler Trimmings and Settings. Radiation. Steam Heating. Boiler, Radiator and Pipe Connections for Steam Heating. Hot Water Heating. The Two-Pipe Gravity System of Hot Water Heating. The Circuit System of Hot Water Heating. The Overhead System of Hot Water Heating. Boiler, Radiator and Pipe Connections for Gravity Systems of Hot Water Heating. Accelerated Hot Water Heating. Expansion Tank Connections. Domestic Hot Water Heating. Valves and Air Valves. Vacuum Vapor and Vacuo-Vapor Heating. Mechanical Systems of Vacuum Heating. Non-Mechanical Vacuum Systems. Vapor Systems. Atmospheric and Modulating Systems. Heating Greenhouses. Information, Rules and Tables. 200 pages, 127 illustrations. Octavo. Cloth. Price =$1.50= ~STEEL~ =Steel: Its Selection, Annealing, Hardening, and Tempering.= By E. R. MARKHAM. This work was formerly known as "The American Steel Worker," but on the publication of the new, revised edition, the publishers deemed it advisable to change its title to a more suitable one. It is the standard work on Hardening, Tempering, and Annealing Steel of all kinds. This book tells how to select, and how to work, temper, harden, and anneal steel for everything on earth. It doesn't tell how to temper one class of tools and then leave the treatment of another kind of tool to your imagination and judgment, but it gives careful instructions for every detail of every tool, whether it be a tap, a reamer or just a screw-driver. It tells about the tempering of small watch springs, the hardening of cutlery, and the annealing of dies. In fact, there isn't a thing that a steel worker would want to know that isn't included. It is the standard book on selecting, hardening and tempering all grades of steel. Among the chapter headings might be mentioned the following subjects: Introduction; the workman; steel; methods of heating; heating tool steel; forging; annealing; hardening baths; baths for hardening; hardening steel; drawing the temper after hardening; examples of hardening; pack hardening; case hardening; spring tempering; making tools of machine steel; special steels; steel for various tools; causes of trouble; high-speed steels, etc. 400 pages. Very fully illustrated. Fourth edition. Price =$2.50= =Hardening, Tempering, Annealing, and Forging of Steel.= By J. V. WOODWORTH. A new work treating in a clear, concise manner all modern processes for the heating, annealing, forging, welding, hardening and tempering of steel, making it a book of great practical value to the metal-working mechanic in general, with special directions for the successful hardening and tempering of all steel tools used in the arts, including milling cutters, taps, thread dies, reamers, both solid and shell, hollow mills, punches and dies, and all kinds of sheet-metal working tools, shear blades, saws, fine cutlery, and metal-cutting tools of all description, as well as for all implements of steel both large and small. In this work the simplest and most satisfactory hardening and tempering processes are given. The uses to which the leading brands of steel may be adapted are concisely presented, and their treatment for working under different conditions explained, also the special methods for the hardening and tempering of special brands. A chapter devoted to the different processes for case-hardening is also included, and special reference made to the adaptation of machinery steel for tools of various kinds, Fourth edition. 288 pages. 201 illustrations. Price =$2.50= ~TRACTORS~ =The Modern Gas Tractor.= By VICTOR W. PAGÉ, M.E. A complete treatise describing all types and sizes of gasoline, kerosene and oil tractors. Considers design and construction exhaustively, gives complete instructions for care, operation and repair, outlines all practical applications on the road and in the field. The best and latest work on farm tractors and tractor power plants. A work needed by farmers, students, blacksmiths, mechanics, salesmen, implement dealers, designers, and engineers. Second edition, revised and enlarged. 504 pages. Nearly 300 illustrations and folding plates. Price =$2.00= ~TURBINES~ =Marine Steam Turbines.= By DR. G. BAUER and O. LASCHE. Assisted by E. LUDWIG and H. VOGEL. Translated from the German and edited by M. G. S. Swallow. The book is essentially practical and discusses turbines in which the full expansion of steam passes through a number of separate turbines arranged for driving two or more shafts, as in the Parsons system, and turbines in which the complete expansion of steam from inlet to exhaust pressure occurs in a turbine on one shaft, as in the case of the Curtis machines. It will enable a designer to carry out all the ordinary calculation necessary for the construction of steam turbines, hence it fills a want which is hardly met by larger and more theoretical works. Numerous tables, curves and diagrams will be found, which explain with remarkable lucidity the reason why turbine blades are designed as they are, the course which steam takes through turbines of various types, the thermodynamics of steam turbine calculation, the influence of vacuum on steam consumption of steam turbines, etc. In a word, the very information which a designer and builder of steam turbines most requires. Large octavo, 214 pages. Fully illustrated and containing eighteen tables, including an entropy chart. Price, net =$3.50= ~WATCH MAKING~ =Watchmaker's Handbook.= By CLAUDIUS SAUNIER. No work issued can compare with this book for clearness and completeness. It contains 498 pages and is intended as a workshop companion for those engaged in watch-making and allied mechanical arts. Nearly 250 engravings and fourteen plates are included. This is the standard work on watch-making. Price =$3.00= ~WELDING~ =Automobile Welding with the Oxy-Acetylene Flame.= By M. KEITH DUNHAM. Explains in a simple manner apparatus to be used, its care, and how to construct necessary shop equipment. Proceeds then to the actual welding of all automobile parts, in a manner understandable by every one. _Gives principles never to be forgotten._ Aluminum, cast iron, steel, copper, brass, bronze, and malleable iron are fully treated, as well as a clear explanation of the proper manner to burn the carbon out of the combustion head. This book is of utmost value, since the perplexing problems arising when metal is heated to a melting point are fully explained and the proper methods to overcome them shown. 167 pages, fully illustrated. Price =$1.00= Every Practical Man Needs A Magazine Which Will Tell Him How To Make And Do Things _=Have us enter your subscription to the best mechanical magazine on the market. Only one dollar a year for twelve numbers. Subscribe today to=_ =Everyday Engineering= A monthly magazine devoted to practical mechanics for everyday men. Its aim is to popularize engineering as a science, teaching the elements of applied mechanics and electricity in a straightforward and understandable manner. The magazine maintains its own experimental laboratory where the devices described in articles submitted to the Editor are first tried out and tested before they are published. This important innovation places the standard of the published material very high, and it insures accuracy and dependability. The magazine is the only one in this country that specializes in practical model building. Articles in past issues have given comprehensive designs for many model boats, including submarines and chasers, model steam and gasoline engines, electric motors and generators, etc., etc. This feature is a permanent one in this magazine. Another popular department is that devoted to automobiles and airplanes. Care, maintenance, and operation receive full and authoritative treatment. Every article is written from the practical, everyday man, standpoint rather than from that of the professional. The magazine entertains while it instructs. It is a journal of practical, dependable information given in such a style that it may be readily assimilated and applied by the man with little or no technical training. The aim is to place before the man who leans toward practical mechanics, a series of concise, crisp, readable talks on what is going on and _how it is done_. These articles are profusely illustrated with clear, snappy photographs, specially posed to illustrate the subject in the magazine's own studio by its own staff of technically-trained illustrators and editors. =The subscription price of the magazine is one dollar per year of twelve numbers. Sample copy sent on receipt of ten cents.= Enter your subscription to this practical magazine with your bookseller. =The Norman W. Henley Publishing Co.,= =2 West 45th Street, New York= +-----------------------------------------------------------------+ | TRANSCRIBER'S NOTES | | | | General remarks: | | There are some differences in wording between the Table of | | Contents, the lists of sections per chapter, and the actual | | section titles. Their meaning is clear, and they have been | | left as they were in the original work. | | Page 56, table: Fig. 8 in the first column does not refer to | | Fig. 8 in this work. | | The original work does not have a Figure 89. | | Page 303, table: it is uncertain what "free with kerosene" | | means, there may be a word omitted. | | Page 544, entirely censored. It is not clear what this page | | originally contained (possibly a table), since text and | | numbering of illustrations are uninterrupted. The text | | "CENSORED" has been moved to after the first paragraph of the | | section on Mercedes Engines. | | The List of Illustrations does not occur in the original work.| | | | Changes made: | | The text of the original work (including inconsistencies in | | accents, spelling, hyphenation and lay-out, and differences | | between the main text, illustrations and advertisements) has | | been followed, except when listed below. Only some minor | | obvious typographical errors have been corrected silently. | | Where the author used x for multiplication, this has been | | replaced by × in the body of the text (not in the | | advertisements or illustrations). | | The illustrations have been moved so as not to disrupt the | | flow of the text. | | Engine and aircraft types are not always named consistently in| | the original; Curtiss engine O X 2, OX-2 and 0X2 have all | | been changed to OX-2, Curtiss aircraft JN4 and JN-4 to JN-4. | | Multi-page tables: repeated headings have been removed, and | | the tables treated as one consecutive table. | | Page 22: "The product of" has been moved into the first | | formula. | | Page 25: "When B × r = M" changed to "When P × r = M". | | Page 74: ".225 ÷ 775 = .2905" changed to ".225 ÷ .775 = | | .2905". | | Page 137 (caption): "Bavary" changed to "Baverey" as | | elsewhere. | | Page 172: "evidently" changed to "evident". | | Page 214: "drop to O" changed to "drop to 0". | | Page 248: "actual from a common" changed to "actuated from a | | common". | | Page 256: "values" changed to "valves". | | Page 280: "Fig. 6" changed to "Fig. 112". | | Page 306: "Fig. 127, B" changed to "Fig. 127, C" (2nd | | reference). | | Page 324: "Rhone" changed to "Le Rhone" as elsewhere. | | Page 334: "Check values" changed to "Check valves". | | Page 364: "LeRhone" changed to "Le Rhone" as elsewhere. | | Page 390: "Fig. 62, D" changed to "Fig. 168, B". | | Page 408: "Stilson" changed to "Stillson" as elsewhere. | | Page 490: "both valves" changed to "both halves". | | Page 514: "standard ratio is 5.3" changed to "standard ratio | | is 5:3". | | Page 529: "gallons per minute 1,400 R. P. M." changed to | | "gallons per minute at 1,400 R. P. M." | | Page 546: "Hispano Suiza" changed to "Hispano-Suiza" as | | elsewhere. | | Page 556: "Diameter of crank-shaft, 56 mm." changed to | | "Diameter of crank-shaft, 55 mm." | | Page 7 (advertisements): "Hazlehurst Field" changed to | | "Hazelhurst Field". | | Page 21 (advertisements): "Rhose Island Compound" changed to | | "Rhode Island Compound". | | Index: "Shebler" changed to "Schebler", "camshaft" to | | "cam-shaft", "wristpin" to "wrist-pin", etc. (all as in text).| +-----------------------------------------------------------------+